Abstract: Oxygen-ozone therapy, initially started as an empirical approach, has now reached a stage where most of the biological mechanisms of action of ozone have been clarified, showing that they are in the realm of orthodox biochemistry, physiology and pharmacology. Here we have reviewed a few relevant clinical applications and have shown that ozone therapy is particularly useful in cardiovascular disorders and tissue ischemia. In chronic viral infections, it is unable to eliminate the viremia but it may display supportive help by stimulating the immune system. Recently, its use has been successfully extended to the herniated disk pathology and therapy of primary caries in children.
Abstract: BACKGROUND: A frequent problem that family doctors face is the meaning of small quantities of blood or protein in urine samples. Patients with this problem are often either neglected or referred to specialists for complex, expensive, and often invasive diagnostic procedures. Exercise testing has never been considered in nephrology, except for some attempts in diabetic patients. METHODS: We report on a study conducted over 12 years with patients referred for slight hematuria and/or proteinuria to determine whether exercise testing could be a diagnostic aid in some or all of them. We performed exercise testing using a treadmill preceded and followed by urine analysis, with a kidney biopsy within 10 days. Of the 94 patients enrolled in the study, only those with a positive exercise test turned out to have parenchymal nephropathy. At the end of the study, we simplified the quantification of exertion, dispensing with the treadmill and drastically reducing the number of urinary parameters considered. RESULTS: In patients with histological evidence of kidney damage, most of the variables increased significantly after the test. Statistical analysis also showed that determination of proteinuria and hematuria alone guaranteed maximum predictability. We found that it is also possible to simplify the quantification of effort/exertion and to drastically reduce the number of urinary parameters and still obtain significant results. CONCLUSIONS: Exercise testing provides useful information about the significance of microhematuria and proteinuria, reducing the number of cases that need to be referred to specialists. The method needs to be validated in other studies, but our results suggest that family doctors could use simple dipsticks to screen the many cases of microhematuria or proteinuria observed in daily practice. The method seems useful in eliminating doubts and unnecessary diagnostic costs.
Abstract: Milky spots are very small omental organs, in contact with peritoneal membrane, devoid of capsule and consisting of macrophages, lymphocytes and a few plasma cells supported by blood and lymphatic vessels. The exact role of these particular organs is still not clear, but they are similar to lymphatic structures and it is clear that they play a role in peritoneal infection and abdominal tumors. Peritoneal dialysis seems to activate the milky spots changing their morphology. The authors try to formulate some hypotheses on the role played by these little omental organs during autologous mesothelial transplant.
Abstract: Sixteen years ago rabbit and human mesothelial cells were successfully cultured and autoimplanted. The aim of the study was merely to demonstrate that mesothelial implant was possible and interesting not only in peritoneal dialysis, but also in the vaster field of medicine and surgery concerning all the mesothelial districts of the body. The aim of this paper is to recollect the steps which have led to autologous mesothelial transplantation and verify if the technique has been validated and adopted by others. Review of the literature published in the last 15 years shows that intraperitoneal transplantation of mesothelial cells has been effective in reducing the formation of peritoneal adhesions, and in remodeling the area of mesothelial denudation. New studies on the mesothelial cell opened the way to construction of transplantable tissue-engineered artificial peritoneum, to the utilization of mesothelial progenitor cells and to find simple methods to collect autologous mesothelial cells. Finally mesothelial transplantation may represent a new neovascular therapy in the prevention and treatment of ischemic coronary heart disease.
Abstract: We have investigated the performance of a new gas exchange device (GED), named L001, specifically devised for the ozonation of human blood during extracorporeal circulation. This procedure, defined with the acronym "EBOO," means "extracorporeal blood oxygenation-ozonation." The innovative GED is made of microporous, ozone-resistant, polipropylene hollow fibers with an external diameter of 200 microm, a thickness of 50 microm, and a membrane surface area of 0.22 m(2). The material is coated with phosphorylcholine on the external side in contact with the circulating blood, while a gas mixture, necessarily composed of medical oxygen and ozone (about 99 and 1%, respectively), flows inside the fibers in opposite direction. The new GED has been tested by using a buffered saline solution containing KI and by varying several parameters, and it has shown to be very versatile and efficient. Its main characteristics are minimal foreign surface contact, high gas transfer, and negligible priming volume. This device appears to be a practical, nontoxic, and rather inexpensive tool for performing ozonation of blood for already defined human diseases.
Abstract: BACKGROUND: In previous studies we were successful in demonstrating that the administration of water over a short period of time increases the transport capacity in the excretory tract of rabbit ureters by increasing urinary volume in the ureter from 0.3 ml/min to 10 ml/min. This phenomenon may explain the effect of water therapy performed in thermal spas, where the administration of 1-2 liters of mineral water is performed in 30-60 minutes. OBJECTIVES: The aim of the present study is to investigate if this increased transport capacity can act also in the renal tubular apparatus to modify the excretion of some endogenous substances. MATERIALS AND METHODS: We evaluated daily renal clearances in ten subjects under basal conditions during supplemental administration of 25 ml/kg of mineral water over a 24-hour period and during the administration of the same amount of water over a 30-minute period. RESULTS: Subjects who drank a water load of 25 ml/Kg over 30 minutes showed a higher diuresis than that observed in those who drank the same amount over a 24-hour period. Creatinine and urea clearance at 24 hours were significantly higher in subjects who drank the water load over 30 minutes. Serum magnesium levels and folic acid levels were also significantly higher in subjects who drank the water load over 30 minutes. CONCLUSIONS: Water administration over a short period of time seems to modify the daily excretion of some endogenous metabolites.
Abstract: The self-locating catheter invented by Nicola Di Paolo has been increasingly used in Italy and elsewhere since 1994, with about a thousand patients currently implanted every year. Twelve grams of tungsten inserted in the tip of the conventional Tenckhoff catheter during extrusion do not significantly change its form, but suffice to keep the tip firmly in the Douglas cavity. The validity of the new catheter is confirmed by a multicentric controlled study in a large population of peritoneal dialysis patients. This trial showed that patients with the new catheter have fewer episodes of peritonitis, tunnel infection, cuff extrusion, catheter malfunction, obstruction and leakage. This paper outlines the present situation and reports a comparative analysis of the costs of Tenckhoff and self-locating catheters.
Abstract: Peritoneal sclerosis is very common in peritoneal dialysis (PD) patients. It can vary from the mild, clinically silent sclerosis always present after years of PD, to rare but dramatic and often fatal cases. In our opinion, peritoneal sclerosis is a single disorder, so its variable manifestations are different stages of one nosological entity: this opinion relies mainly on strong connections in pathophysiology. In our view, the frequency, pathology, animal models, etiology and pathogenesis often show a bimodal configuration with suggests that peritoneal sclerosis is actually two distinct nosological entities: simple sclerosis and sclerosing peritonitis. The former is very frequent, with minor anatomical alterations and low clinical impact; it is reproducible in animals by means of PD, and is clearly due to the poor biocompatibility of PD. The latter is rare, with radical anatomical alterations and high mortality; it can only be reproduced in animal models by means other than PD and seems to be due to factors both related and unrelated to PD.
Abstract: BACKGROUND: Little research has been dedicated to milky spots (MS), except for their role in oncology. In the field of peritoneal dialysis (PD), studying MS could help in understanding peritoneal defenses. METHODS: We reviewed the methods for detecting and counting omental MS and studied modifications induced by chemical and inflammatory stimuli. The reactions of MS to peritoneal catheters, PD solutions, and infection were studied in 32 rabbits. We also evaluated changes in MS in 39 serial omental biopsies from 16 patients with different histories of PD, and examined peritoneal biopsies from 38 patients with sclerosing peritonitis. RESULTS: The catheter provoked an immediate increase in the number and size of MS in rabbits. Intraperitoneal infusion of commercial PD solution containing 1.38% or 3.86% glucose for 30 days led to a slight but significant increase in the number and size of MS, without differences between the two glucose concentrations. Peritonitis caused a sharp increase in the number of MS in rabbits and humans, and a particular transformation. In patients with simple sclerosis, we observed normal MS having the same number and size as in patients without simple sclerosis. A few MS were found in only 2 patients with sclerosing peritonitis. CONCLUSIONS: Peritoneal dialysis activates omental MS. Peritoneal infection leads to a marked increase in the activity of MS, some of which undergo a singular transformation, casting doubt on previous theories about differentiation of MS from other lymphatic organs. Comparison with oncological studies indicates certain contact points. The presence of MS in PD patients with simple sclerosis is in contradiction to other morphological studies sustaining that MS act only when in contact with a fenestrated mesothelial basement membrane. Finally, the shortage of MS in patients with sclerosing peritonitis raises certain questions about etiopathogenesis.
Abstract: AIM: Commercial glucose peritoneal dialysis solutions expose the peritoneum to hyperosmolar glucose containing variable amounts of non-enzymic breakdown products of glucose. These solutions are toxic for the peritoneum. The aim of the present study is to compare in vitro and in vivo characteristics of a new dialysis solution containing carnitine, a naturally occurring compound, as substitute of glucose. MATERIAL AND METHODS: We compared in vitro and in the rabbit a new peritoneal dialysis solution containing carnitine, with two standard bicarbonate glucose peritoneal dialysis solutions and a solution containing icodextrin. RESULTS: In vitro and in vivo the solution containing carnitine seems to be more biocompatible than standard glucose solutions and those containing icodextrin. CONCLUSIONS: In our study the peritoneal dialysis solution containing carnitine seems to prevent the mesothelial changes observed with solutions containing glucose. Since carnitine has been extensively studied and seems to be well tolerated by hemodialysis patients, even at high doses for long periods, clinical trials in humans may be planned in the near future.
Abstract: BACKGROUND: Cleaning the urinary tract by so-called 'wash-out effect' and promoting high diuresis has long been advocated but has had very little scientific backing and few prospective studies in international journals. AIM: To verify whether the physical laws describing the transport force of water in rivers and pipes are also valid for urinary outflow. METHODS: A laboratory model for measuring transport force, given liquid and solid capacity, was adapted to create an in vivo model based on the rabbit urinary tract. RESULTS: Fluid flow in the rabbit renal pelvis and ureters was found similar to flow in pipes, obeying the physical laws of water transport to some extent. When the quantity of liquid flowing in the urinary tract in unit time was doubled, the transport force increased by various orders of magnitude. When the liquid increased by a larger factor, the transport force became enormous. CONCLUSIONS: The results confirm the utility of maintaining high diuresis in patients with renal calculus, but stress the utility of drinking 1-2 liters of hypotonic water in a short time to obtain an enormous increase in transport force which increases the probability of a cleansing effect.
Abstract: The term peritoneal sclerosis can be applied to a vast range of peritoneal alterations. At one end of the range we have the slight peritoneal sclerosis constantly associated with peritoneal dialysis, which may be defined as simple sclerosis. Its clinical impact is slight. The role of glucose in determining peritoneal sclerosis is supported by morphological studies and therefore backed by much biochemical and immunological data.
Abstract: AIM: The etiopathogenesis of sclerosing peritonitis is still debated, with some sustaining that it is a rare form of progression of simple peritoneal sclerosis and others that it is a primitive form. The aim of the present research was to clarify this question. MATERIAL AND METHODS: 438 peritoneal biopsies from 253 patients were re-examined. 174 were obtained prior to peritoneal dialysis and 224 after various periods of dialysis. Forty biopsies were from peritoneal dialysis patients who developed sclerosing peritonitis. Peritoneal morphology was studied for signs of transition from simple sclerosis to sclerosing peritonitis. RESULTS: Evidence was found sustaining the hypothesis that simple sclerosis to sclerosing peritonitis patients have distinct pathologies. CONCLUSIONS: The results confirm previous observations, excluding the existence of any type of relation between simple peritoneal sclerosis to sclerosing peritonitis.
Abstract: BACKGROUND: It is not yet clear whether forced diuresis is useful for flushing out of the urinary tract, especially in cases of renal calculi or infections. A series of experiments conducted initially in vitro and then in vivo in rabbits, using sand and small glass spheres, showed that sediments can be eliminated from the urinary tract by forced diuresis. When distilled water was used, the effect was greater, both as weight of sand and as number of spheres eliminated, than when normal saline was used. The different characteristics of the two liquids gave rise to different intrapelvic pressures for a given flow. MATERIALS AND METHODS: Intrapelvic pressures, and liquid and solid discharges in vitro and in rabbits were used in a fluid mechanics analysis of the phenomenon to obtain non-dimensional formulae so that the results in rabbits could be extended to humans. RESULTS: The results made it possible to evaluate solid transport capacity induced in a healthy human of given weight by drinking a given quantity of water in an hour. CONCLUSIONS: The mathematical model makes it possible to determine the quantity of water a patient must drink to induce a transport force sufficient for urinary tract wash-out.
Abstract: BACKGROUND: Since 1990 our group has been using extracorporeal circulation to ozonate blood by an original method, known as extracorporeal blood oxygenation and ozonation (EBOO), with the aim of amplifying the results observed with ozone autohemotherapy. OBJECTIVE: To verify the hypothesis that EBOO improves the skin lesions typical of peripheral artery disease (PAD) patients. METHODS: Twenty-eight patients with PAD were randomized to receive EBOO or intravenous prostacyclin in a controlled clinical trial. The primary efficacy parameters were regression of skin lesions and pain,and improvement in quality of life and vascularisation. RESULTS: Patients treated with EBOO showed highly significant regression of skin lesions with respect to patients treated with prostacyclin. Other parameters that were significantly different in the two groups of patients were pain,pruritus, heavy legs and well-being. No significant differences in vascularisation of the lower limbs before and after treatment were found in either group. No side effects or complications were recorded during the 210 EBOO treatments. CONCLUSION: EBOO was much more effective than prostacyclin for treating skin lesions in PAD patients and also had a positive effect on patient general condition without any apparent change in arterial circulation. This suggests other mechanisms of action of EBOO.
Abstract: Some lines of evidence have suggested that the challenge to antioxidants and biomolecules provoked by pro-oxidants such as ozone may be used to generate a controlled stress response of possible therapeutic relevance in some immune dysfunctions and chronic, degenerative conditions. Immune and endothelial cells have been proposed to be elective targets of the positive molecular effects of ozone and its derived species formed during blood ozonation. On the bases of these underlying principles and against often prejudicial scepticism and concerns about its toxicity, ozone has been used in autohemotherapy (AHT) for four decades with encouraging results. However, clinical application and validation of AHT have been so far largely insufficient. Latterly, a new and more effective therapeutic approach to ozone therapy has been established, namely extracorporeal blood oxygenation and ozonation (EBOO). This technique, first tested in vitro and then in vivo in sheep and humans (more than 1200 treatments performed in 82 patients), is performed with a high-efficiency apparatus that makes it possible to treat with a mixture of oxygen-ozone (0.5-1 microg/ml oxygen) in 1 h of extracorporeal circulation up to 4800 ml of heparinized blood without technical or clinical problems, whereas only 250 ml of blood can be treated with ozone by AHT. The EBOO technique can be easily adapted for use in hemodialysis also. The standard therapeutic cycle lasts for 7 weeks in which 14 treatment sessions of 1 h are performed. After a session of EBOO, the interaction of ozone with blood components results in 4-5-fold increased levels of thiobarbituric acid reactants and a proportional decrease in plasma protein thiols without any appreciable erythrocyte haemolysis. On the basis of preliminary in vitro evidence, these simple laboratory parameters may represent a useful complement in the routine monitoring of biological compliance to the treatment. The clinical experience gained so far confirms the great therapeutic potential of EBOO in patients with severe peripheral arterial disease, coronary disease, cholesterol embolism, severe dyslipidemia, Madelung disease, and sudden deafness of vascular origin. Extensive investigation on oxidative stress biomarkers and clinical trials are under way to validate this new technique further.
Abstract: The peritoneal histology of 224 peritoneal dialysis (PD) patients without sclerosing peritonitis (SP) and of 39 PD patients with SP was evaluated. Of the 224 patients, 180 showed simple sclerosis (SS). In these subjects, slight thickness of sclerosis (10 - 70 microm), slight parvicellular infiltration (5/180), slight arterial thickening with no vessel occlusion (19/180), and slight tissue calcification (1/180) were observed. In the 39 patients with SP, striking histological changes versus SS were detected: thickness of sclerosis 250 - 4000 microm, p < 0.01; inflammation 39/39, p < 0.01 (parvicellular infiltration 36/39, p < 0.01; microabscesses 15/39, p < 0.05; giant cells 38/39, p < 0.01; granulation tissue 38/39, p < 0.01); arterial alterations 39/39, p < 0.01 (thickening 39/39, p < 0.01; occlusion 39/39, p < 0.01; calcification 26/39, p < 0.01; ossification 9/39, p < 0.01); tissue calcification 12/39, p < 0.01 (with ossification 4/39, with bone marrow 2/39). The thickness of sclerosis in SS was higher in parietal (30 - 70 microm) than in visceral peritoneum (10 - 40 microm, p < 0.05); in SP it was higher in visceral (600 - 4000 microm) than in parietal peritoneum (250 - 2000 microm, p < 0.05). These striking differences suggest consideration of SS and SP as two separate nosological entities. Differences in frequency, animal models, etiology, and clinical impact seem to confirm this hypothesis, showing that SP is not just the evolution of SS.
Abstract: The case of a continuous hemodialysis patient who died shortly after erroneous infusion with undiluted hypertonic solution is reported. Autopsy showed small parenchymal hemorrhages in all organs. Although producers take measures to prevent such errors by hospital staff, further steps are suggested for types of dialysis requiring reinfusion of large quantities of reinfusion hemodialysis solution.
Abstract: BACKGROUND: The self-locating catheter invented by Nicola Di Paolo has been used increasingly in Italy and elsewhere since 1994, with about a thousand patients currently implanted every year. Twelve grams of tungsten inserted into the tip of the conventional Tenckhoff catheter during extrusion does not significantly change its form, but suffices to keep the tip firmly in the Douglas cavity. OBJECTIVE: The aim of the present study was to confirm our preliminary results in a large population of peritoneal dialysis patients. SETTING: 16 Italian nephrology departments. RESULTS: In addition to confirming the validity of the new catheter, the present results show that patients with the new catheter have fewer episodes of peritonitis, tunnel infection, cuff extrusion, catheter malfunction, obstruction, and leakage. CONCLUSION: The present multicenter control study confirms preliminary results and demonstrates that complications of peritoneal dialysis, such as cuff extrusion, infection, peritonitis, early leakage, and obstruction, are statistically less frequent in patients with self-locating catheters than in patients with classic Tenckhoff catheters.
Abstract: BACKGROUND: Peritoneal dialysis (PD) patients rarely develop sclerosing peritonitis (SP), a severe, life-threatening condition of unknown pathogenesis. Ossification of the peritoneum (PO) is a rare occurrence, which has, however, been reported in PD patients with SP. OBJECTIVE: To investigate etiopathogenetic correlations between PO and SP by histopathological examination. METHOD: We examined biopsy specimens, obtained by laparoscopy or during surgery from 36 patients with SP, from all parts of Italy in the past 8 years for evidence of peritoneal calcification or ossification. Other studies were performed on a sample of dense white material found under the parietal peritoneum of 1 patient during laparoscopy. RESULTS: Ossification of the peritoneum was found in 4/16 patients with calcifications. In addition to PO, we also found bone marrow in two specimens and arterial ossification in one case. In specimens with calcifications, and especially those with ossification, there was evidence of peritoneal inflammation with infiltration of lymphocytes, multinuclear giant cells, macrophages, and mast cells. The chemical composition of the whitish material was 85% calcium chloride and 15% hydroxyapatite. CONCLUSIONS: Calcifications alone were found in 33% (12/36) of cases of SP; 11% of SP cases were complicated by both peritoneal calcification and ossification (4/36), which indicates great availability of calcium under conditions of inflammation. Where does this calcium come from? In 1 patient with PO, the quantity of calcium was enormous and its unusual composition suggested a link with the calcium contained in dialysis solution.
Abstract: BACKGROUND: Up until now, there was little known about the use of bone resorption markers in the assessment of bone status in patients with chronic renal failure (CRF). The present study evaluated the ability of a new immunoassay for N-terminal telopeptide of type I collagen to assess bone turnover in a group of hemodialyzed patients. METHODS: The following parameters were measured in a fasting blood sample from 111 patients on maintenance hemodialysis for at least 2 years and in 120 healthy subjects: calcium, phosphorus, magnesium, BALP, PTH, and N-terminal telopeptide of type I collagen (NTx-ELISA, OSTEOMARK NTx Siero-Ostex International). RESULTS: Serum PTH, BALP, and NTx were significantly higher (P<0.001) in hemodialyzed (HD) patients than in healthy subjects. In HD patients, PTH was correlated to BALP and NTx (r=0.40 and 0.55, respectively). When combining PTH and BALP serum levels, 17 patients showed high turnover (HT) and 65 were found to have a normal to low turnover (N-LT). In HT patients, serum NTx and dialytic age were significantly (P<0.01) higher than in N-LT patients. Moreover, even after adjusting for age, body mass index, dialytic age, and calcium-vitamin D treatment, serum NTx discriminated between HT and N-LT with a sensitivity of 97.6% and a specificity of 90.9%. CONCLUSION: Although bone biopsy remains the reference method for the diagnosis of renal osteodystrophy, the combined use of markers of bone resorption and bone formation could improve the clinical management of renal bone diseases.
Abstract: A case of necrotizing fasciitis in a dialysis patient is described. Since traditional therapies were unsuccessful, extracorporeal blood oxygenation and ozonation (EBOO) was tried. This technique is no longer in the experimental stage and is used routinely in our hospital. Patient condition improved radically after EBOO.
Abstract: Exposure of human blood ex vivo to oxygen-ozone (O2-O3) using either dialysis exchangers or normal oxygenators gives rise to a number of problems, one of which linked to platelet activation, leads to rapid occlusion and no gas exchange. Semipermeable membranes were found unsuitable because, except for one, they were gas-transfer inefficient, allowed ultrafiltration and were more or less vulnerable to O3. Over the last three years we have examined several types of hydrophobic O3-resistant hollow fiber capillaries but, if the polypropylene surface is not properly coated, there is platelet aggregation and blood coagulation. These problems while far less relevant with O2 alone, become prohibitive in the presence of ozone. Recently new oxygenators have been prepared with special materials to make them more biocompatible and it has become possible to oxygenate and ozonate up to 5L of blood in about an hour, thus making the treatment of critical patients feasible.
Abstract: Milky spots are submesothelial lymphoid structures, essential for the maturation of resident peritoneal macrophages, for peritoneal defense, and for all peritoneal inflammatory and immune processes. We evaluated the number and size of milky spots in omentum of rats subjected to dialysis for 15, 30, and 60 days and in omentum of non dialyzed control rats (5 rats per group). After 15 days of dialysis, the number (4.2 +/- 1.5/cm2) and mean size (0.13 +/- 0.04 mm2) of milky spots were significantly lower than in the control group (7.6 +/- 2.3/cm2, p < 0.03; 0.25 +/- 0.04 mm2, p < 0.01). After 30 days of dialysis, values returned to a level similar to that in controls (6.8 +/- 1.9/cm2 and 0.20 +/- 0.04 mm2). After 60 days of dialysis, values were significantly greater than in all other groups (11.8 +/- 2.2/cm2 and 0.41 +/- 0.07 mm2, p < 0.03). The early decrease in milky spots seems to be due to washing of the peritoneum and replacement of resident white cells at the expense of the white cell population in the milky spots. At 30 days, a process of adaptation seems to establish functional equilibrium. The increase in milky spots after 60 days of dialysis may be due to the chronic inflammatory stimulus of dialysis solutions with poor biocompatibility.
Abstract: Rat and rabbit are the most common animal models for peritoneal dialysis. Rats are cheap and easy to keep. Rabbits allow dialysis to be performed for longer periods and in a way very similar to that used in human patients. Recent progress in histomorphometry enables accurate comparison of the biocompatibility of different peritoneal dialysis solutions. Preliminary data in the rabbit indicate that peritoneal dialysis is associated with a change in both the number and size of milky spots, which are peritoneal corpuscles involved in peritoneal defence.
Abstract: The term peritoneal sclerosis simply means the presence of sclerotic tissue in the peritoneum. Qualitative and quantitative morphological aspects indicate that there are two nosological entities: simple sclerosis and sclerosing peritonitis. Simple sclerosis is a thin (<40-50 microm) layer of submesothelial sclerotic tissue often limited to certain peritoneal areas, with monotonous histology. It is a component of the slight anatomical alterations constantly detectable in peritoneal dialysis patients. Sclerosing peritonitis is characterized by very thick (1,0004,000 microm) sclerotic tissue involving the whole peritoneal wall, often with inflammatory infiltrates, microabscesses, giant cells of macrophagic origin, calcifications and severe vascular alterations. Intermediate stages between simple sclerosis and sclerosing peritonitis have rarely been detected. Simple sclerosis and sclerosing peritonitis also seem to be distinct with respect to frequency, etiology, reproducibility in animal models and clinical manifestations.
Abstract: Autohemotherapy with ozone has been used for four decades with encouraging results but, owing to the lack of clinical studies, it has never been adopted by orthodox medicine. Confident of the valid principles of ozone therapy, we have endeavoured to increase its therapeutic efficacy. Over a ten-year period we have developed an apparatus that makes it possible to treat large quantities of blood with ozone in extracorporeal circulation (extracorporeal blood oxygenation and ozonation EBOO). One of us volunteered to test the system and after six treatments noted the disappearance of two lipomas. This prompted us to treat a patient with Madelung disease and several patients with atherosclerotic vasculopathy. Besides showing therapeutic effects, the preliminary results indicate that EBOO is clinically valid, without side-effects and worthy of testing in various diseases.
Abstract: The frequency, pathology, animal models, pathogenesis, clinical manifestations, diagnostic criteria, therapy and prevention of peritoneal sclerosis are reviewed. Many of these aspects have a bimodal configuration which suggests that peritoneal sclerosis, usually considered a single pathology in peritoneal dialysis, is actually two distinct nosological entities: simple sclerosis and sclerosing peritonitis. The former is very frequent, with minor anatomical alterations and low clinical impact; it is reproducible in animals by means of peritoneal dialysis, and is clearly due to the poor biocompatibility of peritoneal dialysis solutions. The latter is rare, with radical anatomical alterations and high mortality requiring valid methods of diagnosis, therapy and prevention; it can only be reproduced in animal models by means other than peritoneal dialysis and seems to be due to factors both related and unrelated to peritoneal dialysis.
Abstract: The definition of peritoneal sclerosis encompasses a vast range of peritoneal alterations induced by peritoneal dialysis. The morphology, clinical correlations and pathophysiology of, and experimental animal models for, this condition show such striking differences from case to case as to suggest the existence of two nosological entities: simple sclerosis and sclerosing peritonitis.
Abstract: We investigated whether exposure of blood ex-vivo to oxygen-ozone (O2-O3) through a gas exchanger is feasible and practical. We first evaluated the classical dialysis-type technique but we soon realized that semipermeable membranes are unsuitable because they are hydrophilic and vulnerable to O3. We therefore adopted a system with hydrophobic O3-resistant hollow fibers enclosed in a polycarbonate housing with a membrane area of about 0.5 m2. First we tested the system with normal saline, determining the production of hydrogen peroxide (H2O2) at O3 concentrations from 5 to 40 microg/ml. We then evaluated critical parameters by circulating swine blood in vitro; this revealed that heparin is not an ideal anticoagulant for this system. Finally, we performed several experiments in sheep and defined optimal anticoagulant dose (sodium citrate, ACD), priming solution, volume of blood flow per min, volume and concentration of O2-O3 mixture flowing countercurrent with respect to blood and the time necessary for perfusion in vivo. The biochemical parameters showed that an O3 concentration as low as 10 microg/ml is effective; this means that gas exchange and O3 reactivity are rapid and capable of inducing biological effects. The sheep showed no adverse effects even after 50 min of extracorporeal circulation at higher O3 concentrations (20 to 40 microg/ml) but the exchanger became less effective (low pO2 values) due to progressive clogging with cells.
Abstract: The term "peritoneal sclerosis" encompasses a vast range of peritoneal alterations, from the manifestations of low clinical impact constantly associated with peritoneal dialysis, to dramatic thickening of the peritoneal membrane, which is rare, but often life-threatening. The epidemiology, pathology, etiopathogenesis, clinical manifestations, diagnostic criteria, therapy and prevention of peritoneal sclerosis are reviewed.
Abstract: Renal osteodystrophy (ROD) can be characterized by both high (HT) and low (LT) bone turnover states. Although bone biopsy remains the "gold standard" to diagnose ROD, noninvasive tools for the diagnosis and follow-up of such bone disease are desirable. Recently, ultrasound (US) techniques, proposed to assess skeletal status, have been shown to be correlated not only with bone density but also with bone quality. We have investigated 98 patients on chronic hemodyalisis (HD) and 98 healthy, sex- and age-matched subjects. Amplitude-dependent speed of sound (AD-SOS) and ultrasound bone profile score (UBPS) at phalanxes and speed of sound (SOS), broadband ultrasound attenuation (BUA), and a quantitative ultrasound index (QUI/stiffness) at the heel were performed in both groups. In all subjects intact parathyroid hormone (PTH), total alkaline phosphatase (T-ALP), bone isoenzyme alkaline phosphatase (B-ALP), and carboxy-terminal telopeptide of type I collagen (ICTP) were assessed. All US parameters were significantly lower in the hemodialysis group than in control subjects. Moreover, among US parameters only AD-SOS and UBPS showed a significant correlation with PTH, T-ALP, and B-ALP. Dialytic age showed a modest, but significant correlation only with US parameters at the phalanxes. On the basis of bone biochemical markers, we considered a group with high and a group with normal to low bone turnover. AD-SOS and UBPS, but not SOS, BUA, and stiffness were significantly (p < 0.01) lower in the high bone turnover than in low bone turnover group. Furthermore, in the high bone turnover group, parameters of the US phalanxes strongly correlated with B-ALP. Our results seem to demonstrate that US parameters are a useful tool in the assessment of skeletal status in patients on maintenance dialysis.
Abstract: The term peritoneal sclerosis encompasses a vast range of peritoneal alterations, from the low clinical impact manifestations associated with chronic peritoneal dialysis, to dramatic thickening of the peritoneal membrane, which is rare, but often life-threatening. The frequency, pathology, etiopathogenesis, clinical manifestations, diagnostic criteria, therapy, and prevention of peritoneal sclerosis are reviewed. Preliminary observations from the Italian Registry of Peritoneal Sclerosis, established in the framework of a program of the Italian Society of Nephrology, are reported.
Abstract: Analysis of expressed sequence tags (ESTs) constitutes a useful approach for gene identification that, in the case of human pathogens, might result in the identification of new targets for chemotherapy and vaccine development. As part of the Trypanosoma cruzi genome project, we have partially sequenced the 5' ends of 1, 949 clones to generate ESTs. The clones were randomly selected from a normalized CL Brener epimastigote cDNA library. A total of 14.6% of the clones were homologous to previously identified T. cruzi genes, while 18.4% had significant matches to genes from other organisms in the database. A total of 67% of the ESTs had no matches in the database, and thus, some of them might be T. cruzi-specific genes. Functional groups of those sequences with matches in the database were constructed according to their putative biological functions. The two largest categories were protein synthesis (23.3%) and cell surface molecules (10.8%). The information reported in this paper should be useful for researchers in the field to analyze genes and proteins of their own interest.
Abstract: OBJECTIVE: To determine the biocompatibility of a peritoneal dialysis (PD) solution containing amino acids compared to PD solutions containing glucose. DESIGN: The biocompatibility of three dialysis solutions containing 1.1% amino acids, 1.36% glucose, and 3.86% glucose, respectively, was evaluated in vivo in rabbits. METHODS: After 60 days of PD, peritoneal histological changes in rabbits were investigated by light and transmission electron microscopy. The parameters investigated were: (1) mesothelial damage; (2) submesothelial edema; (3) submesothelial cell infiltration; (4) submesothelial fibrosis; and (5) vascular alterations. Semiquantitative evaluations were performed for all the above alterations; quantitative morphometric evaluation was performed for mesothelial damage (cubic transformation of the mesothelium, areas devoid of mesothelium, submesothelial edema) and thickness of peritoneal arteriole walls. RESULTS: (1) Mesothelial damage was practically nonexistent in rabbits dialyzed with the solution containing amino acids, and intermediate and severe with low-glucose and high-glucose solutions, respectively. Both controls and rabbits dialyzed with amino acid solution showed flat continuous mesothelium; rabbits dialyzed with low-glucose solution showed cubic continuous mesothelium; and rabbits dialyzed with high-glucose solution showed cubic discontinuous mesothelium. Cytopathic mesothelial effects were slight with the solution containing amino acids and severe with both the low- and high-glucose solutions. Duplication and thickening of mesothelial basement membrane were never observed. (2) Submesothelial edema showed a worsening trend from controls to rabbits dialyzed with solution containing amino acids, low glucose, and high glucose. (3) No difference in submesothelial infiltration was found between groups. (4) Submesothelial fibrosis was never observed. (5) Vascular alterations were never observed. CONCLUSION: These results are evidence that PD solution with amino acids is more biocompatible than high- and also low-glucose solutions.
Abstract: Cardiovascular damage is common in young cocaine addicts, and similar atherosclerotic lesions seem likely in the kidneys. To confirm this hypothesis, we performed histological examination of 40 kidney autopsy specimens classified as "cocaine-related deaths"; as controls, kidney specimens of 40 road accident victims were examined. Semiquantitative analysis showed that the ratio of the number of glomeruli affected by hyalinosis to the total number of glomeruli was 0.09 +/- 0.13 in addicts and 0.005 +/- 0.01 in controls; the difference was highly significant. The degree of periglomerular fibrosis was significantly higher in cocaine addicts than in accident victims. The ratio of glomeruli to tubular casts was 0.15 +/- 0.17 in cocaine addicts and 0.17 +/- 0.18 in controls (not significant). The degree of interstitial cellular infiltration was significantly higher in addicts than controls. A monunuclear cell infiltrate was observed prevalently in the medullary region. Arteriolar sclerosis was significantly higher in addicts than controls. Medial thickening, luminal narrowing and vessel obstruction were absent in the control group. Quantitative morphometric analysis of arterial structure showed significantly greater lumen circumference, intima circumference, media circumference, intima area, media area, intima thickness and media thickness in cocaine addicts than in controls.
Abstract: Few studies have dealt with assaying aluminium levels in different tissues of uremic patients; so far a comparison has never been made between its accumulation in the various tissues of uremic patients and controls. Aluminium levels were determined in the following biological samples: 1) 111 serum samples from hemodialysis patients and 55 serum samples from normal subjects; 2) 47 urine samples from the same dialysis patients and 45 from the controls; autopsy tissue specimens (blood, bile, brain, rib, cartilage, cranium, lung, spleen, kidney, aorta, vena cava, liver, muscle) from 12 deceased dialysis patients undergoing post-mortem diagnosis and 10 autopsy cases in which death was not associated with uremia. In living subjects, both serum and urinary levels of aluminium are significantly higher in hemodialysis patients than in controls; a significant positive correlation was found between serum and urinary levels of aluminium. In autopsy specimens, aluminium levels were higher in the dialysis group than controls for all tissues; the differences were statistically significant except in heart and urine. Tissue concentrations of aluminium in the two groups were then analysed separately both in uremic patients and controls. The highest values found in dialysis cases were in the bile, followed by blood, urine and lung; levels in the other tissues were considerably lower. In controls, the distribution was somewhat different, due to much lower levels in the liver and bile with respect to dialysis cases. Again we found surprisingly high levels in the lung. The results show that aluminium storage in uremic patients occurs in all organs and tissues, albeit to different degrees.
Abstract: The morphometric and morphological changes in the mesothelial cell population were studied in rabbits in peritoneal dialysis with lactate and bicarbonate buffer solution. During dialysis the mesothelial population underwent radical changes in morphology and morphometric analysis showed a significant increase in cell size. Light microscope examination showed two types of changes: hyperplasia of the mesothelial cell with diameters of up to 80 microns, nucleus proportional to the cytoplasm, a large nucleole giving an owl's eye appearance and cytoplasm rich in granular material. The second change was multiple nuclei and arrest of cell division. Nuclear division occurred, but no separation of the cytoplasm. The cells became larger than 200 microns, packed with nuclei and relatively little cytoplasm. Electron microscopy confirmed that the hyperplastic cells had perfect structure whereas the polynucleate cells contained vacuoles and little cytoplasmic reticulum. Immunohistochemistry using monoclonal antibodies SK2-27 and SK 60-61 specific to cytokeratins 14, 16, 17 and 8, 18, respectively, identified the cells as mesothelial. The changes were related to the glucose content of the peritoneal dialysis solution. Glucose is therefore the bioincompatible agent that modifies the mesothelium during peritoneal dialysis, causing it to become hyperplastic or blocking replication.
Abstract: OBJECTIVE: Using the erythrocyte as a model for other kinds of cells not directly exposed to peritoneal dialysis (PD) solutions, we investigated the tolerance of the cell metabolism to lactate and bicarbonate buffers. DESIGN: We studied, in vivo (in two groups of 5 PD patients each) and in vitro, the Embden-Meyerhof pathway (EMP) because it represents a potential target for the unphysiological effects of lactate or bicarbonate buffers. The EMP is the main glucose-utilizing route in the red blood cell (RBC), producing energy and reducing power. METHODS: The enzymatic activities of the key steps in the glycolytic pathway and the energy charge (EC), determined by the levels of phosphorylated adenine nucleotides, were investigated spectrophotometrically and by high performance liquid chromatography (HPLC) in two groups of patients undergoing lactate (L-group) and bicarbonate (B-group) PD, respectively. The in vitro effects of both bicarbonate and lactate buffers on some EMP enzyme activities and energy production were determined. Cellular pH (pHi) was also investigated. RESULTS: The B-group showed an EC value near the control levels, while in the L-group a significantly lower EC value was observed (t-test: p < 0.05 vs both B-group and controls). The key enzymes in the EMP, and in particular hexokinase, were higher in the L-versus B-group (p < 0.03 for the comparison of the Hk mean values). As demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, the bound form of glyceraldehyde-3-phosphate dehydrogenase (G-3-PD), an inactive form of this EMP enzyme, was significantly higher in the L-group with respect to the B-group (p < 0.004). In the in vitro experiments, high lactate concentrations acutely inhibited the key enzymatic steps of glycolysis, producing a significant decrease in glucose consumption and adenosine triphosphate production. These effects were not observed when bicarbonate was used in the incubations. Both in vivo and in vitro lactate, but not bicarbonate, induce a significant drop in pHi (p < 0.05). Decreased levels of pHi like those observed in the lactate-incubated RBC were demonstrated to be able to inhibit G-3-PD activity (25 +/- 2%) here used as an indicator of the actual decrease in pH. CONCLUSION: This study provides evidence for a damaging action of lactate with respect to bicarbonate buffer on the RBC metabolism. This condition was demonstrated observing a cell energy depletion, which coincides in vitro with an acute EMP impairment; the lactate accumulation together with the consequent lowering of pHi seem to be responsible for this effect, which was not observed when bicarbonate was used instead of lactate.
Abstract: Hydrothorax during peritoneal dialysis is a very tedious complication. Many authors have described techniques of performing diagnosis and therapeutic procedures to take care of these complications. We describe a method to perform diagnosis and therapy by videothoracoscopy. Videothoracoscopy permits identification and closure of the tiny flaws in the diaphragm.
Abstract: OBJECTIVE: Peritoneal catheters often become dislocated, and this may lead to malfunction. Since it is not usually possible to bring them back into their correct position, they must be replaced. With the aim of preventing this complication, we designed a new catheter. DESIGN: The new catheter has the same form as the Tenckhoff catheter except for a small increase in external diameter of the last 2 cm, made possible by the high specific weight of a small 12-g tungsten cylinder incorporated in the Silastic at the abdominal end. The new catheter may be inserted by a percutaneous technique. SETTING: University hospitals of Siena and Perugia, Italy. PATIENTS: In the last three years, 32 of these catheters have been implanted for a total experience of 468 patient-months. Their position was checked on insertion and every two months thereafter by radiography; 26 Tenckhoff catheters (415 patient-months) were studied at the same time. Insertion was performed surgically and by a percutaneous method. The frequency of cuff extrusion, exit-site infections, leakage, and peritoneal infection were noted, together with peritoneal function, which was evaluated by KT/V and weekly creatinine clearance one month after catheter insertion; the tests were repeated when dislocation occurred and at the end of the trial. RESULTS: No dislocations occurred with the self-locating catheters, whereas nine dislocations occurred in control patients (p = 0.0003). There were no significant differences with respect to controls for cuff extrusion, exit-site infections, leakage, peritoneal infection, and peritoneal function. CONCLUSIONS: The presence of a small weight at the catheter up prevents displacement completely, keeping the intraperitoneal part of the catheter in place.
Abstract: Mysterious deaths of archeologists after opening Egyptian tombs have been suspected, but never proved, to be secondary to inhalation of mycotoxin. We observed a case of acute renal failure (ARF) due to inhalation of ochratoxin A produced by a mould of the species Aspergillus ochraceus. After working 8 h in a granary closed for several months, a farmer and his wife suffered respiratory distress; the woman developed non-oliguric ARF and biopsy revealed tubulonecrosis. A strain of Aspergillus ochraceus producing ochratoxin was isolated from the wheat.
Abstract: Mysterious deaths of archeologists after opening Egyptian tombs have been suspected to be secondary to inhalation of mycotoxin, however, the hypothesis has never been verified. Recently, we observed a case of acute renal failure (ARF) undeniably due to inhalation of ochratoxin of Aspergillus ochraceus. After spending 8 h in a granary which had been closed for several months, a farmer and his wife suffered temporary respiratory distress; 24 h later, the woman developed nonoliguric ARF and biopsy revealed tubulonecrosis which healed in 24 days. Toxic substances were not found, but a strain of A. ochraceus producing ochratoxin was isolated from the wheat.
Abstract: A new method of evaluating urinary sediment, based on electronic processing of the images obtained by traditional microscopy, has been developed. Preliminary data suggests that the method can clarify many doubts on the real diagnostic value of UED.
Abstract: Human and rabbit peritoneal mesothelial cells have been successfully cultured and autoimplanted. An original biopsy technique was used to take samples of peritoneal mesothelial cells and after culture they were characterized from the structural and caryological points of view. Staphylococcal peritonitis was induced in 12 rabbits with indwelling peritoneal catheters and after 4 days of antibiotics 6 of them were autoimplanted with cultured autologous mesothelial cells previously marked in 3 cases with thymidine (H3TdR). Direct morphological observation and autoradiography were used to compare the mesothelium of control rabbits and implanted rabbits sacrificed on days 3 and 6 and showed that the cell implants had taken. Four uremic CAPD patients recovering from severe peritonitis were implanted with about 300 million autologous peritoneal mesothelial cells, previously cultured and frozen. Morphological signs of taking were evident from peritoneal laparoscopy biopsies performed 3 and 6 days after implant. The aim of the study was merely to demonstrate that such implants are possible; however, the techniques may have interesting applications not only in peritoneal dialysis, but also in the vaster fields of medicine and surgery.
Abstract: With the purpose of studying peritoneal physiology, original biopsy methods were devised and human and rabbit peritoneal mesothelial cells cultured and characterized. It was then decided to verify whether these cells could be implanted autologously during peritoneal dialysis in cases of acute loss of mesothelial surface. Staphylococcal peritonitis was induced in 12 rabbits and after 4 days of antibiotics, 6 of them were autoimplanted with cultured mesothelial cells, previously marked in 3 cases with thymidine (H3TdR). Implanted rabbits sacrificed after 3 and 6 days showed taking of the new mesothelial cells both by direct morphological observation and by autoradiography. Four uremic CAPD patients recovering from severe peritonitis were implanted with 300 million of their own peritoneal mesothelial cells, previously cultured and frozen. Morphological signs of taking were evident by laparoscopy and from peritoneal biopsies performed 3 and 6 days after implant. The fact that such implants are possible may have interesting applications in medicine and surgery.
Abstract: Replication of the basement membrane of the peritoneal capillaries and the mesothelium is observed in all uremic patients after a period of continuous ambulatory peritoneal dialysis (CAPD). Biopsy specimens of the parietal peritoneum were taken in diabetic and non-diabetic patients on insertion or repositioning of the CAPD catheter. The basement membrane of the capillaries and mesothelium was normal in non-diabetics on insertion of the catheter, but after 2 to 66 months of CAPD, multiple replication was found. In nearly all the diabetics there was already replication of the basement membrane of the peritoneal capillaries before CAPD was begun but the basement membrane of the mesothelium was intact. After several months of CAPD thickening of the basement membrane of the capillaries was found in 36% of diabetics, sometimes to the point of occlusion. After CAPD, replication of the basement membrane of the mesothelium has been observed in both diabetics and non-diabetics although it is initially perfectly normal in both. CAPD is proposed as an experimental model for diabetic microangiopathy in man.
Abstract: Success in culturing human and animal peritoneal mesothelial cells for the purpose of study, led us to determine whether these cells could be autoimplanted in animals and man during peritoneal dialysis in cases of acute and extensive loss of mesothelial surface area. Using an original biopsy technique, we were able to cultivate and characterize from the structural and caryological point of view, human and rabbit peritoneal mesothelial cells. Staphylococcal peritonitis was provoked in 12 rabbits with in-dwelling peritoneal catheters and after 4 days of antibiotic therapy, 6 of them were autoimplanted with cultured mesothelial cells. In the animals sacrificed on the third and sixth days, direct morphological observation and autoradiographic techniques showed that the transplanted cells had taken and revealed a different picture from that in the non-transplanted rabbits. In a 56 year old female diabetic patient, upon insertion of the first peritoneal catheter, a specimen of mesothelial cells was cultured and then frozen. Seven months later after an episode of peritonitis from candida which dictated removal of the peritoneal catheter, since there was a sufficient number of cultured mesothelial cells and the patient consented, the implant was performed. Peritoneal biopsy by laparoscopy three and six days later showed that the cells had taken. The purpose of the study was merely to show that autoimplant of mesothelium in man and animals is possible.
Abstract: Complex hemostatic changes in uremic patients are characterized by platelet distress and prolonged bleeding time. Dialysis corrects platelet function and improves the bleeding time but introduces a tendency to thrombophilia. The uremic patient is thus an excellent model for the evaluation of hemostatic drugs. VUEFFE (VF) is a new hemostatic agent which reduces bleeding time without modifying clotting parameters. Changes in hemostasis and coagulation were studied in 42 hemorrhagic uremic subjects in dialysis or on conservative management. The patients were divided into two groups, one of which was given oral VF and the other oral placebo. 84% of those receiving VF ceased bleeding within 15 days (compared to 25% for placebo) and there was a significant reduction in bleeding time. The drug can be given orally or parenterally, is well tolerated and without side effects, making it suitable for administration to hemorrhagic uremic patients.
Abstract: In the last 3 years we performed 52 peritoneal biopsies (PB) in 31 patients on continuous ambulatory peritoneal dialysis (CAPD). Samples of the parietal peritoneum were obtained either during insertion of the catheter or while it was being repositioned or removed. PB was performed in 13 patients before initiating CAPD and in 27 after 7-49 months of CAPD while 7 had PB during peritonitis, and, again, in 5 of these cases, PB was repeated after 1-4 months for light, electron transmission, and scanning electron microscopy. BP after CAPD showed that mesothelial cells were irregularly spaced, and at times we observed alterations in the cellular structure. Rarely were these cells degenerating, while rarefaction and in many cases complete absence of microvilli were observed. In some cases the submesothelial layers showed rarefaction of the connective tissue and sclerosis. During peritonitis, PB showed more alterations with marked degeneration and in some cases necrosis of the mesothelium and alterations of connective tissue. PB performed some months after peritonitis showed only a partial regression of these alterations and sclerotic patches, and no microvilli were noted in the mesothelium.
Abstract: Peritoneal effluent of patients on chronic ambulatory peritoneal dialysis (CAPD) contains a surface-active material (SAM) made up of phospholipids and showing phosphatidylcholine on thin-layer chromatography. This substance drastically lowers surface tension, helps to repel water and has a lubricating effect. The presence of stratified phosphatidylcholine on the peritoneum might narrow the stagnant dialysate fluid layer and situations which can alter the quantity or composition of SAM may affect peritoneal transport and also, perhaps, the formation of adherences. This led us to verify, experimentally, the presence of phospholipids in basal conditions, after CAPD and during peritonitis and to check if addition of phosphatidylcholine to dialysis liquid is able to modify water transport in patients with low ultrafiltration and peritonitis. Phospholipids in the dialysis effluent of patients who have been on CAPD for a long time are lower than observed in the first days of peritoneal dialysis. A more drastic, significant decrease in phospholipids was observed in patients with low ultrafiltration and in patients with peritonitis. Mean ultrafiltration significantly increases in patients with low ultrafiltration and in those with peritonitis during dialysis exchanges containing phosphatidylcholine (50 mg/l) indicating that the latter is able to restore normal physiological conditions.
Abstract: To eliminate the discomfort caused by surgical methods and the risks involved using the trocar, for 1 year we have been using a new technique for insertion of peritoneal catheters (PC). We devised a steel instrument, vaguely resembling a rhinoscope, composed of two semicones. The handles are connected by a screw to permit dilatation of the semicones. After local anesthesia, an introducer needle is inserted into the peritoneal cavity. A guide-wire is passed through the needle which is then withdrawn and our instrument is placed around the guide and gently pushed into the peritoneal cavity. The guide is now removed and squeezing the handles of the instrument we introduce the PC up to 2 cm beyond the first Dacron cuff. When the catheter is in place, the instrument is removed and a subcutaneous tunnel may be made. We have used this method for 25 patients. 14 were new cases while 11 underwent PC repositioning. For all patients this new method proved to be excellent with practically no leakage and PC were utilized immediately or after only 24 h. We emphasize the brief time for PC insertion, the minimum discomfort and the simplicity of the technique.
Abstract: It is well established that cerebral blood flow (CBF) is low in patients with high hematocrit and is high in anemic patients. An inverse relationship between CBF and hematocrit has been found. Furthermore, if hematocrit is reduced, CBF increases. There is some debate as to whether these observations are due to viscosity or to oxygen carrying capacity of the blood. In order to further elucidate this problem, CBF, blood viscosity and hematocrit were measured in 4 patients with paraproteinemias before and after paraproteins had been removed by plasmapheresis without changes in hematocrit. After plasmapheresis, blood viscosity significantly decreases and CBF increases by a mean of 24.4 ml/100 g/min. Mean arterial blood pressure and hematocrit were not influenced by plasmapheresis. These results indicate that blood viscosity is an important factor in determining CBF. This does not exclude the role of oxygen transport as an associated factor, but it is evident that oxygen transport and blood viscosity are independent variables in the control of CBF.
Abstract: Motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNVC) and distal motor latencies times (DMLT) were evaluated both in upper and lower limbs in three groups of 15 patients of comparable age, treated respectively by extracorporeal dialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and combined peritoneal dialysis (CPD) for comparable sufficiently long periods. Moreover, MNCV was monitored longitudinally in two groups of patients shifted from CAPD to HD and vice versa. The results show a significant superiority of peritoneal dialysis and particularly of CAPD with respect to HD in controlling uremic neuropathy.
Abstract: The reasons why the peritonitis rate in patients on CAPD with the traditional connection system remains unacceptably high are investigated and identified. In order to overcome such a highly limiting complication, a complete revision of the connection philosophy is suggested, substituting the exasperate prevention of the contamination with a simpler and more effective sterilization of the connection site after the connection has been made. Practical examples of chemical and thermal sterilization are illustrated.
Abstract: In the treatment of end stage renal disease, continuous ambulatory peritoneal dialysis has undoubtedly contributed more towards the solution of its inherent problems than any other peritoneal dialysis technique. Despite the validity of the basic idea, there are still many drawbacks, one of which is the high cost of commercial dialysis. While the manual procedure was indeed simple, we have preferred to concentrate our interest on a modern technology, such as that used for hemodialysis not only making possible the inexpensive preparation of peritoneal dialysates, but also avoiding the hazards usually involved in the preparation, sterilization and storing of the filled bags. We have built a machine composed of 4 modular automatic units, which will prepare the dialysate at pH 7 with no trace of methylfurfurol and which will also monitor the peritoneal dialysis procedure permitting a vast variety of schedules. It will also provide for a special schedule for overnight dialysis or simply fill bags as they are needed.
