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Theodoros Maltaris

maltaris@uni-mainz.de

Journal articles

2008
 
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Mueller, Maltaris, Häberle, Hoffmann, Beckmann, Dittrich (2008)  Pretreatment with gonadotropin-releasing hormone (GnRH) antagonists to prevent the flare-up effect of long-acting GnRH agonists: results of a pilot study.   Fertil Steril Apr  
Abstract: This study evaluated in vivo whether the flare-up effect of GnRH agonists can be suppressed through pretreatment with a GnRH antagonist. The classic flare-up effect caused by 3.8 mg goserelin acetate could not be suppressed through pretreatment using a single dosage of 3.24 mg cetrorelix acetate.
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2007
 
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Dittrich, Beckmann, Maake, Oppelt, Mueller, Hoffmann, Naumann, Koelbl, Maltaris (2007)  The extracorporeal perfusion of the female pig detrusor as an experimental model for the study of bladder contractility.   Neurourol Urodyn Jul  
Abstract: AIMS: The objective of the study was to establish an experimental model for the extracorporeal perfusion of the pig detrusor. In order to validate this model we examined some biochemical parameters and determined the effect of carbachol on the contractility of perfused female pig bladders. METHODS: Twenty-six pig bladders were perfused with Krebs-Ringer bicarbonate-glucose buffer for a period up to 5 hr with the aim to preserve a viable organ, which would be responsive to contraction-inducing agents. The intravesical pressure of the bladder as well as the intraarterial pressure of the vesical arteries were recorded before and after administration of carbachol. RESULTS: The perfusate pH, lactate, partial carbon dioxide tension, and the ATP content in the perfused tissue, all indicators of tissue ischemia or cell necrosis, showed a good preservation of the organ for up to 5 hr. Carbachol was able to induce contractions of the prefilled bladder with a complete draining of the bladder throughout the whole perfusion period. CONCLUSIONS: We could demonstrate that this perfusion system was able to preserve the pig bladder in a functional condition, appropriate for the study of physiological questions. Neurourol. Urodynam. (c) 2007 Wiley-Liss, Inc.
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Theodoros Maltaris, Rudolf Seufert, Franz Fischl, Michael Schaffrath, Kunhard Pollow, Heinz Koelbl, Ralf Dittrich (2007)  The effect of cancer treatment on female fertility and strategies for preserving fertility.   Eur J Obstet Gynecol Reprod Biol 130: 2. 148-155 Feb  
Abstract: Aggressive chemotherapy and radiotherapy in young patients with cancer has greatly enhanced the life expectancy of these patients, but these treatments often cause infertility because of the massive destruction of the ovarian reserve resulting in premature ovarian failure (POF). This review focuses on the effect of cancer treatments on fertility and on the various surgical and assisted-reproduction innovations that are available to provide the patient with the option of future pregnancies. As the emerging discipline of fertility preservation is steadily attracting increasing interest, developments in the near future promise to be very exciting. However, in everyday routine work, better interdisciplinary cooperation between gynecological and pediatric oncologists, surgeons, immunologists and endocrinologists is necessary so that individualized options for fertility preservation can be offered in advance of surgical procedures or cancer treatments. GnRH analog treatment can preserve fertility in some patients, but not in all. At present, cryopreservation of ovarian tissue appears as a very promising method of providing the cancer patient with a realistic chance of preserving fertility-a prospect that is also extremely important to patients for psychological reasons.
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C Dragonas, T Maltaris, H Binder, M Kat, A Mueller, S Cupisti, I Hoffmann, M W Beckmann, Ralf Dittrich (2007)  Progesterone bioavailability with a progesterone-releasing silicone vaginal ring in IVF candidates.   Eur J Med Res 12: 6. 264-267 Jun  
Abstract: A vaginal ring made of silicone polymers and barium sulfate, and containing 1 g of pure micronized progesterone, was developed for luteal supplementation in women undergoing cycles of in vitro fertilization (IVF). The ring, modeled on the Estring, was designed as a means of providing continuous intravaginal delivery of progesterone. Bioavailability of progesterone in the blood was demonstrated for 24 hours in IVF candidates who had an endogenous progesterone deficiency after treatment with gonadotropin-releasing hormone (GnRH) analogues. After the first 4 h of increasing release of progesterone from the ring (with mean serum levels of 1.39 +/- 0.8 ng/ml after 4 h), only a slight increase in serum progesterone levels (with a mean peak of 1.5 +/- 0.45 ng/ml after 24 h) was observed during the rest of the test period. Gonadotropin levels were not affected after insertion of the ring. The ring was well tolerated by the patients. The maximum serum progesterone level was lower in comparison with other forms of progesterone application, but it should be sufficiently high, due to the uterine first-pass effect. This study demonstrated that progesterone administration through a silicone ring for luteal support is feasible in IVF treatment. As the vaginal ring is very well tolerated by the patients, these findings may encourage the pharmaceutical industry to design an appropriate progesterone ring for luteal support.
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Theodoros Maltaris, Matthias W Beckmann, Helge Binder, Andreas Mueller, Inge Hoffmann, Heinz Koelbl, Ralf Dittrich (2007)  The effect of a GnRH agonist on cryopreserved human ovarian grafts in severe combined immunodeficient mice.   Reproduction 133: 2. 503-509 Feb  
Abstract: This prospective study compares the effect of a GnRH agonist on the number of follicles in different developmental stages in cryopreserved human ovarian grafts transplanted into gonadotropin-stimulated or not stimulated severe combined immunodeficient mice (SCID mice). Human ovarian tissue from seven patients was cryopreserved with an open-freezing system and xenotransplanted in SCID mice. The SCID mice were then treated according to different stimulation protocols. The survival of the tissue after cryopreservation was examined by LIVE/DEAD viability staining or transplanted in the neck muscle of 41 SCID mice. Development of follicles, estradiol production, vaginal cytology, and uterus weight were assessed after 15 weeks with or without gonadotropin stimulation. Viable follicles were detected in all frozen/thawed specimens using the LIVE/DEAD assay. Triptorelin, a GnRH agonist, caused a significant reduction of follicles in all developmental stages in the non-gonadotropin-stimulated animals (P<0.001). In gonadotropin-stimulated animals, GnRH agonist treatment has no significant effect on primordial, primary and preantral follicle count, whereas the antral follicles were significantly fewer (P = 0.03). The GnRH agonist treatment is not able to prevent the primordial follicle depletion after the xenografting of ovarian tissue in SCID mice with or without gonadotropin stimulation. Furthermore, it causes an additional loss of follicles if administered during the critical neovascularization period after the transplantation.
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S Cupisti, R Dittrich, H Binder, N Kajaia, I Hoffmann, T Maltaris, M W Beckmann, A Mueller (2007)  Influence of body mass index on measured and calculated androgen parameters in adult women with Hirsutism and PCOS.   Exp Clin Endocrinol Diabetes 115: 6. 380-386 Jun  
Abstract: There is growing evidence that obesity in women lead to a more severe form of hyperandrogenism and other endocrine abnormalities which may have some health implications later in life. Obese females are at higher risk for metabolic syndrome due to severe hyperandrogenemia. Calculated values for free testosterone are equivalent to those obtained by equilibrium dialysis, which is one of the reference measurement procedures (RMP) for estimation of free testosterone and may be capable of replacing values estimated using RMP's. For adult women correlations of body mass index (BMI) with calculated free (cFT) and bioavailable testosterone (cBT) are still rare, while these data are reported for peripubertal and adolescent girls. In this study we aimed to investigate the association between BMI and different androgen parameters (including calculated free and bioavailable testosterone, free androgen index, and sex hormone-binding globulin [SHBG]) in adult women with Hirsutism and with PCOS. In hirsute women with BMI > or = 25 kg/m2 measured total testosterone (TT) was significantly higher, SHBG was significantly lower and the calculated androgen parameter (FAI, cFT and cBT) were significantly higher compared to women with BMI < 25 kg/m2. In PCOS women with BMI > or = 25 kg/m2 TT was significantly higher, SHBG was significantly lower and the calculated androgen parameter (FAI, cFT and cBT) were also significantly higher compared to women with BMI < 25 kg/m2. In both the Hirsutism and PCOS-group there was a positive correlation between BMI and TT, cFT, and cBT, while BMI was negatively correlated with SHBG. In summary, in adult women with Hirsutism and PCOS obesity is associated with increased levels of TT and decreased levels of SHBG resulting in significant elevated calculated free and bioavailable testosterone levels. Obesity might lead to a more severe form of hyperandrogenism with elevated calculated free and bioavailable testosterone in the study population.
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Theodoros Maltaris, Matthias W Beckmann, Andreas Mueller, Inge Hoffmann, Joachim Kohl, Ralf Dittrich (2007)  Significant loss of primordial follicles after prolonged gonadotropin stimulation in xenografts of cryopreserved human ovarian tissue in severe combined immunodeficient mice.   Fertil Steril 87: 1. 195-197 Jan  
Abstract: This study evaluated the effect of gonadotropin stimulation on the primordial follicle reserve of cryopreserved human ovarian tissue after transplantation in severe combined immunodeficient mice. We found that prolonged gonadotropin stimulation significantly reduces primordial follicles.
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2006
 
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Theodoros Maltaris, Charalampos Dragonas, Inge Hoffmann, Andreas Mueller, Ralf L Schild, Werner Schmidt, Matthias W Beckmann, Ralf Dittrich (2006)  The extracorporeal perfusion of the swine uterus as an experimental model: The effect of tocolytic drugs.   Eur J Obstet Gynecol Reprod Biol 126: 1. 56-62 May  
Abstract: OBJECTIVE: Comparison of the effect of tocolytic drugs on isolated swine uterus preparations. STUDY DESIGN: Forty swine uteri were perfused with the aim to preserve a viable organ, which should be responsive to oxytocic hormones and tocolytic pharmaca. An intrauterine catheter recorded the pressure changes. After initiation of rhythmical uterine contractions we administered known tocolytic drugs (fenoterol, ritodrine, terbutaline, propofol, acetylsalicylic acid, alcohol, atosiban, verapamil, and glyceryl trinitrate) in various concentrations. RESULTS: Perfusate pH and lactate, partial oxygen and carbon dioxide tensions, and oxygen saturation in the perfusate showed good preservation of the organ for up to 8h. All substances showed a tocolytic effect on the swine uterus. The effect varied substantially with regard to the length of the contraction free intervals, which was our main effect parameter. Fenoterol, acetylsalicylic acid, and alcohol showed the most and glyceryl trinitrate the least powerful effect. CONCLUSIONS: A direct comparison of various tocolytic substances in the same experimental model showed the best effect for fenoterol. Furthermore, we could demonstrate that the swine uterus perfusion system is a suitable model to study the influence of various conditions like the administration of drugs or the induction of oxidative stress on the uterus function.
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Andreas Mueller, Theodoros Maltaris, Joern Siemer, Helge Binder, Inge Hoffmann, Matthias W Beckmann, Ralf Dittrich (2006)  Uterine contractility in response to different prostaglandins: results from extracorporeally perfused non-pregnant swine uteri.   Hum Reprod 21: 8. 2000-2005 Aug  
Abstract: BACKGROUND: Prostaglandins (PGs) are important stimulators of uterine contractility. Limited data are available at present on the effects of different PGs on uterine contractility, measured using intraluminal pressure changes in the complete uterus. The goal of this study was to assess dynamic changes in uterine contractility and peristalsis in response to PGs in comparison with the effects of oxytocin administration. METHODS: An extracorporeal perfusion model of swine uteri was used, which keeps the uterus in a functional condition, and is appropriate for the study of physiological questions. Oxytocin- and PG-induced uterine contractility and peristalsis were assessed using an intrauterine double-chip microcatheter. RESULTS: A dose-dependent increase in intrauterine pressure (IUP) in the isthmus uteri (P < 0.001) and the corpus uteri (P < 0.001) was observed after the administration of PGF(2alpha) and oxytocin, which reached a plateau after further stimulation. A dose-dependent increase in IUP in the isthmus uteri (P < 0.001) and the corpus uteri (P < 0.001) was also observed after the administration of PGE(1) and PGE(2), with a plateau in IUP in the middle-concentration range and a decrease in the course of further stimulation. PGE(2) caused significantly more contractions starting in the corpus uteri and moving to the isthmus uteri (P = 0.008). The direction of most contractions caused by PGE(1), PGE(2) and oxytocin differed from that of PGF(2alpha). CONCLUSIONS: This study demonstrates that the PGs tested modulate contractility in non-pregnant swine uteri in a characteristic way, resulting in different contractility patterns.
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Theodoros Maltaris, Charalampos Dragonas, Inge Hoffmann, Andreas Mueller, Ralf L Schild, Werner Schmidt, Matthias W Beckmann, Ralf Dittrich (2006)  The extracorporeal perfusion of the swine uterus as an experimental model: The effect of tocolytic drugs.   Eur J Obstet Gynecol Reprod Biol 126: 1. 56-62 May  
Abstract: OBJECTIVE: Comparison of the effect of tocolytic drugs on isolated swine uterus preparations. STUDY DESIGN: Forty swine uteri were perfused with the aim to preserve a viable organ, which should be responsive to oxytocic hormones and tocolytic pharmaca. An intrauterine catheter recorded the pressure changes. After initiation of rhythmical uterine contractions we administered known tocolytic drugs (fenoterol, ritodrine, terbutaline, propofol, acetylsalicylic acid, alcohol, atosiban, verapamil, and glyceryl trinitrate) in various concentrations. RESULTS: Perfusate pH and lactate, partial oxygen and carbon dioxide tensions, and oxygen saturation in the perfusate showed good preservation of the organ for up to 8h. All substances showed a tocolytic effect on the swine uterus. The effect varied substantially with regard to the length of the contraction free intervals, which was our main effect parameter. Fenoterol, acetylsalicylic acid, and alcohol showed the most and glyceryl trinitrate the least powerful effect. CONCLUSIONS: A direct comparison of various tocolytic substances in the same experimental model showed the best effect for fenoterol. Furthermore, we could demonstrate that the swine uterus perfusion system is a suitable model to study the influence of various conditions like the administration of drugs or the induction of oxidative stress on the uterus function.
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T Maltaris, H Kaya, I Hoffmann, A Mueller, M W Beckmann, R Dittrich (2006)  Comparison of xenografting in SCID mice and LIVE/DEAD assay as a predictor of the developmental potential of cryopreserved ovarian tissue.   In Vivo 20: 1. 11-16 Jan/Feb  
Abstract: This study compared the predictive value of the LIVE/DEAD fluorescence viability assay to xenotransplantation in SCID mice, regarding the developmental potential of cryopreseved human ovarian tissue for fertility preservation purposes. The thawed ovarian tissue of ten patients was partly examined by LIVE/DEAD viability staining or histologically examined after transplantation and gonadotropin stimulation in 30 SCID mice. The LIVEIDEAD assay showed 87.1 +/- 3.5% (mean +/-SD, n=10) viable follicles (intact oocyte and more than 50% of granulosa cells alive). Histological examination showed follicles in all developmental stages in the transplanted grafts. The total number of follicles found was much lower than with the LIVE/DEAD assay (8.9 +/- 3.1 versus 54.4 +/- 20.0, p < 0.001). If the LIVE/DEAD assay yields > approximately 85% viable follicles, it can be assumed that the follicles in the cryopreserved tissue have maintained their developmental potential. This assay is, therefore, a suitable diagnostic method before an intended retransplantation.
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Andreas Mueller, Joern Siemer, Stefan Renner, Inge Hoffmann, Theodoros Maltaris, Helge Binder, Matthias W Beckmann, Ralf Dittrich (2006)  Perfused non-pregnant swine uteri: a model for evaluating transport mechanisms to the side bearing the dominant follicle in humans.   J Reprod Dev 52: 5. 617-624 Oct  
Abstract: Adequate uterine contractility and periovulatory peristalsis, interpreted as "rapid sperm transport" to the side bearing the dominant follicle, may be a precondition for successful reproduction in humans. Estrogen and progesterone fluctuate characteristically during the menstrual cycle, and their source is the dominant follicle and corpus luteum. The question is, how is the direction to the left or right side of transport mechanisms influenced? An extracorporeal perfusion model of the swine uterus was used that maintained the uterus in a functional condition and that was suitable for the study of physiological questions. The effects of side-dependent estrogen, progesterone, and estrogen plus progesterone perfusion on oxytocin-induced uterine peristalsis were assessed using two intrauterine microcatheters placed in each horn of the swine uterus. Estrogen perfusion was associated with an increase in intrauterine pressure (IUP) in a dose-dependent manner only in the estrogen-perfused horn of the swine uterus. There was a significant difference between the IUP increase measured in the estrogen-perfused horn and that in the non estrogen-perfused horn of the swine uterus. Progesterone perfusion showed no effect in general. Furthermore, progesterone antagonized the estrogen effects. This study demonstrates that side-dependent estrogen perfusion resulted in side-dependent contractility in the swine uterus perfusion system used. These observations show that estrogen stimulates uterine contractility in the estrogen-perfused uterine horn and that estrogens may be the "trigger" for the transport mechanisms to the side bearing the dominant follicle during the periovulatory phase through their locally increased concentration and distribution via the utero-ovarian counter-current system in humans.
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T Maltaris, R Dittrich, W Widjaja, C Sindhuwinata, I Hoffmann, Mw Beckmann, A Mueller (2006)  The role of oestradiol in the uterine peristalsis in the perfused swine uterus.   Reprod Domest Anim 41: 6. 522-526 Dec  
Abstract: This study was designed to examine the effects of oestradiol (E2) on sperm transport in the swine uterus. The bicornuate swine uterus is optimal for the study of the uterine transport and peristalsis because the influence of various factors can be examined on each uterine horn independently. Forty swine uteri (with or without ovarectomy) were perfused for a period of up to 7 h. Two different E2 concentrations (3 or 30 pg/ml) in the perfusion medium were administered for 30 min unilaterally. Through an intracervical catheter 1 ml of a high concentrated dextran blue solution was administered directly in the upper part of the cervix. After bilateral perfusion of the swine uterus with a bolus of 0.3 IU oxytocin the distribution of coloured particles was assessed macroscopically before and after incision of the uterine horns. Coloration was evaluated by two observers blinded to the site-specific administration of E2. In the 10 ovarectomized uteri with the 3 pg/ml E2 concentration a unilateral distribution towards the side of oestradiol administration was observed in six uteri, in four it was a bilateral distribution. In the 10 non-ovarectomized uteri with the 3 pg/ml E2 concentration a uni- and ipsilateral coloration was observed in five uteri, in five it was a bilateral distribution. In the 20 uteri with 30 pg/ml E2, a unilateral coloration of the uterus horns was observed in all uteri. Oestradiol is one of the main factors, which influences the direction of the sperm transport in a dose-dependent manner, in the perfused swine uterus.
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Theodoros Maltaris, Daniel Boehm, Ralf Dittrich, Rudolf Seufert, Heinz Koelbl (2006)  Reproduction beyond cancer: a message of hope for young women.   Gynecol Oncol 103: 3. 1109-1121 Dec  
Abstract: OBJECTIVE: Aggressive chemotherapy and radiotherapy or radical oncological surgery in young women with cancer has greatly enhanced these patients' life expectancy, but these treatments often cause infertility or premature ovarian failure due to a massive destruction of the ovarian reserve. The objective of this review is to discuss the effect of the various cancer treatments on fertility and present the various fertility sparing operations and fertility preservation strategies. METHOD: An extensive survey of the most up-to-date literature was performed. RESULTS: This review discusses the impact of current cancer treatment on fertility potential and the various surgical and assisted-reproduction innovations available today for the most common cancers in young women. Although the ability to retain reproductive potential is becoming a major quality-of-life factor in an increasing number of young female cancer survivors, they are still being poorly counseled with regard to the negative impact of the treatment on their fertility and on their options for fertility preservation. CONCLUSION: As the emerging discipline of fertility preservation is steadily attracting increasing interest, developments in the near future promise to be very exciting. However, in everyday routine work, better interdisciplinary cooperation between gynecological and pediatric oncologists, surgeons, immunologists, and endocrinologists is necessary so that individualized options for fertility preservation can be offered in advance of surgical procedures or cancer treatments.
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Theodoros Maltaris, Heinz Koelbl, Rudolf Seufert, Franklin Kiesewetter, Matthias W Beckmann, Andreas Mueller, Ralf Dittrich (2006)  Gonadal damage and options for fertility preservation in female and male cancer survivors.   Asian J Androl 8: 5. 515-533 Sep  
Abstract: It is estimated that in 2010, 1 in every 250 adults will be a childhood cancer survivor. Today, oncological surgery, radiotherapy and chemotherapy achieve relatively high rates of remission and long-term survival, yet are often detrimental to fertility. Quality of life is increasingly important to long-term survivors of cancer, and one of the major quality-of-life issues is the ability to produce and raise normal children. Developments in the near future in the emerging field of fertility preservation in cancer survivors promise to be very exciting. This article reviews the published literature, discusses the effects of cancer treatment on fertility and presents the options available today thanks to advances in assisted-reproduction technology for maintaining fertility in male and female patients undergoing this type of treatment. The various diagnostic methods of assessing the fertility potential and the efficacy of in vitro fertilization (IVF) after cancer treatment are also presented.
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Theodoros Maltaris, Charalampos Dragonas, Inge Hoffmann, Andreas Mueller, Matthias W Beckmann, Ralf Dittrich (2006)  Simple prediction of the survival of follicles in cryopreserved human ovarian tissue.   J Reprod Dev 52: 4. 577-582 Aug  
Abstract: This study examines the possible predictive value of the LIVE/DEAD fluorescence viability assay for evaluation of survival of cryopreserved human ovarian tissue. Ovarian tissue from ten patients was examined by LIVE/DEAD viability staining before and after cryopreservation and after freezing in a -20 C freezer (negative control). After cryopreservation with a slow freezing protocol and cryoprotectant the LIVE/DEAD assay showed 86% viable follicles (an intact oocyte and at least more than 50% of the granulosa cells alive), whereas after freezing at -20 C the survival rate was 67%. The healthy follicular loss after cryopreservation was 4%, whereas with freezing at -20 C, it was 25%. Although this assay overestimates the survival rate of cryopreserved primordial follicles, if the LIVE/DEAD assay yields greater than approximately 85% viable follicles, it can be assumed that the follicles in the cryopreserved tissue have maintained their developmental potential and that the tissue is suitable for retransplantation.
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Theodoros Maltaris, Heinz Koelbl, Franz Fischl, Rudolf Seufert, Markus Schmidt, Joachim Kohl, Matthias W Beckmann, Helge Binder, Inge Hoffmann, Andreas Mueller, Ralf Dittrich (2006)  Xenotransplantation of human ovarian tissue pieces in gonadotropin-stimulated SCID mice: the effect of ovariectomy.   Anticancer Res 26: 6B. 4171-4176 Nov/Dec  
Abstract: The number of follicles were compared in different developmental stages after the cryopreservation of human ovarian tissue by open freezing system followed by xenotransplantation into severe combined immunodeficient (SCID)-mice under stimulation, with and without ovariectomy. Ovarian tissue, cryopreserved for fertility preservation was partly examined by LIVE/DEAD viability staining or was transplanted in the neck muscle of 32 SCID-mice. The development of follicles, estradiol production, vaginal cytology and uterus weight was assessed after 15 weeks under gonadotropin stimulation, with or without ovariectomy. Viable follicles were detected in all frozen/thawed specimens using the LIVE/DEAD assay. Ovariectomy caused a significant improvement of survival of follicles in the preantral and antral stages in the gonadotropin-stimulated animals (p < 0.001), whereas there was no significant effect on the primordial and primary follicle counts. In the non-ovariectomised group, only isolated primordial and primary follicles could be detected. The total follicle amount was significantly higher in the ovariectomised group (n=17, 9.2 +/- 7.8, mean +/-SD) than in the non-ovariectomized group (n=15, 0.3 +/- 1.0). This study demonstrates that ovariectomy of stimulated recipient SCID-mice is essential for the development of follicles after xenotransplantation of cryopreserved human ovarian grafts.
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R Dittrich, T Maltaris, A Mueller, A Dimmler, I Hoffmann, F Kiesewetter, M W Beckmann (2006)  Successful uterus cryopreservation in an animal model.   Horm Metab Res 38: 3. 141-145 Mar  
Abstract: Cryopreservation of whole organs would not only be advantageous for experimental biology but also for transplantation surgery. The objective of this study was to evaluate the feasibility of cryopreserving swine uterus as an experimental model of cryopreservation affecting a whole visceral muscle organ. Organs were frozen slowly (0.2 degrees C/min) after arterial perfusion with 10% dimethyl sulfoxide solution for 10 min and equilibration in this solution for 30 min. Viability of the organs was tested by biochemical parameters, LIVE/DEAD fluorescent staining and capability for contraction in a perfusion system. Ten fresh and ten cryopreserved uteri showed living cells in the LIVE/DEAD assay, and were viable for at least 7 h as shown by their ability to produce rhythmic contractions after oxytocin administration. This is the first report known to us on successful cryopreservation of a whole swine uterus to demonstrate that perfusion with a cryoprotectant and slow freezing provides a promising method for cryopreserving whole organs, and may encourage further studies with other cryoprotective agents and freezing protocols as well as other organs.
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Theodoros Maltaris, Arno Dimmler, Andreas Müller, Inge Hoffmann, Matthias W Beckmann, Ralf Dittrich (2006)  Comparison of two freezing protocols in an open freezing system for cryopreservation of rat ovarian tissue.   J Obstet Gynaecol Res 32: 3. 273-279 Jun  
Abstract: AIM: To compare two freezing protocols in an automatic open-vessel freezing system for cryopreservation of rat ovarian tissue. METHODS: Ovarian tissue was transplanted heterotopically into the neck muscle, either without cryopreservation (group 1, n = 6) or with cryopreservation after equilibration with 1.5 mol/L dimethyl sulfoxide and propanediol (protocol A, group 2, n = 6) or 1.5 mol/L ethyl glycol (protocol B, group 3, n = 6). The ovarian tissue was examined with LIVE/DEAD fluorescent viability staining and histologically after isotransplantation. RESULTS: The healthy follicular loss (intact oocyte and >50% granulosa cells alive) due to cryopreservation was 15.5% with protocol A and 12.2% with protocol B. Histological examination showed follicles in all developmental phases in all groups: group 1, 35.5 +/- 5.7/mm(2) (mean +/- SD); group 2, 16.0 +/- 5.0/mm(2); group 3, 17.3 +/- 5.7/mm(2). The differences between groups 1 and 2 and between groups 1 and 3 were significant (P < 0.001). The difference between groups 2 and 3 was not significant (P = 0.33). CONCLUSIONS: These results demonstrate that the use of an open freezing system with both freezing protocols allows cryopreservation of rat ovarian tissue with equally good survival rates.
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2005
 
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R Dittrich, T Maltaris, C Dragonas, C Huber, M W Beckmann, F Kiesewetter (2005)  Individual assessment of sperm morphology of single spermatozoa used for intracytoplasmic sperm injection.   Andrologia 37: 1. 53-56 Feb  
Abstract: Intracytoplasmic sperm injection (ICSI) is an integral part of assisted reproduction. Although many papers have shown that global sperm count, sperm motility and sperm morphology of the ejaculate play no role in the fertilization rate after ICSI, embryologists who carry out ICSI, try to use the 'best looking' spermatozoa. The aim of the study was to investigate whether those spermatozoa with the best morphology really achieve the highest fertilization rate. In the present study, a total of 798 spermatozoa used for ICSI were documented by high-resolution photo. After ICSI the oocytes were cultured in single droplets and the formation of pronuclei was assessed 16 h later. The spermatozoa (all normal according to WHO criteria) were classified into four groups of different morphology. Group 1: normal head shape (approximately 5 microm diameter), group 2: like group 1, but with 15-20% smaller diameter, group 3: like group 1, but with 15-20% larger diameter, and group 4: like group 1, but with slight mid-piece cytoplasmic irregularities. Using the Pearson chi-square test, no significant difference in terms of fertilization was found among the different groups, showing that marginal sperm differences do not alter the fertilization process in ICSI.
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Andreas Mueller, Ralf Dittrich, Helge Binder, Werner Kuehnel, Theodoros Maltaris, Inge Hoffmann, Matthias W Beckmann (2005)  High dose estrogen treatment increases bone mineral density in male-to-female transsexuals receiving gonadotropin-releasing hormone agonist in the absence of testosterone.   Eur J Endocrinol 153: 1. 107-113 Jul  
Abstract: OBJECTIVE: To study the effect of estrogen (E) on the male skeleton in the absence of testosterone (T). DESIGN: Retrospective analyses of 40 middle-aged transsexuals treated with subcutaneous injections of gonadotropin-releasing hormone agonist every 4 weeks and oral 17-beta-estradiol-valerat 6 mg/day over two years until reassignment surgery. METHODS: The bone mineral density (BMD) in the femoral neck and lumbar spine (L2-L4) was measured with dual-energy X-ray absorptiometry at the beginning of cross-sex hormone treatment, after 12 and 24 months, and serum T, E, sex hormone-binding globulin (SHBG), calcitonin (CAL), osteocalcin (OSC), and urinary free deoxypyridinoline (DPD) were measured. RESULTS: After 12 months, a significant increase in BMD in the lumbar spine from 1.2 to 1.234 g/cm2 and after 24 months to 1.274 g/cm2 was observed. There was a significant increase in BMD in the femoral neck area from 1.068 to 1.109 g/cm(2) after 24 months. There was a significant decrease in serum T levels from 18.65 to 0.57 nmol/l after 12 months, and to 0.62 nmol/l after 24 months, a significant increase in SHBG levels from 50.09 to 125 nmol/l after 12 months, and to 130 nmol/l after 24 months, and a significant increase in serum E levels from 73.42 to 881.6 pmol/l after 12 months, and to 923.62 pmol/l after 24 months of cross-sex hormone treatment. Serum levels of CAL, OSC and urinary DPD were unchanged. CONCLUSION: We conclude that high dose E treatment is able to increase BMD significantly in the femoral neck and lumbar spine independently of serum T levels in middle-aged men. There is no risk of osteoporosis developing in male-to-female transsexuals receiving GnRHa when there is an adequate E substitution.
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Charalampos Dragonas, Andreas Mueller, Theodoros Maltaris, Peter Kraemer, Arno Dimmler, Wolfram Jaeger, Matthias W Beckmann, Ralf Dittrich (2005)  Role of insulin in the progression of ovarian sex cord stromal tumors in rats.   J Cancer Res Clin Oncol 131: 11. 751-757 Nov  
Abstract: PURPOSE: This study examined the effect of insulin on sex cord stromal tumors in the rat. METHODS: Sex cord stromal tumors were induced by transplantation of ovaries under the splenic capsule of ovariectomized rats (Lewis-inbred). These tumors were then transplanted into new inbred rats. Hyperglycemic conditions were induced by treatment with streptozotocin (STZ, which selectively destroyed pancreatic islet cells) and hypoglycemic conditions by treatment with a subcutaneously implanted insulin pump (Alzet). The animals were killed 28, 56, and 84 days later. Tumor growth, animal weight, food and water consumption, and serum concentrations of glucose, FSH, LH, and estradiol were measured. RESULTS: Treatment with STZ and insulin with osmotic Alzet pumps induced continuous hypoglycemic and hyperglycemic conditions, respectively. No significant influence of the hypoglycemic or hyperglycemic status on tumor growth was measured during the first 28 and 56 days. Eighty-four days after transplantation and substitution of 1 or 2 IU/100 g body weight/d insulin, there was a significant stimulation of tumor growth (2.2-fold and 2.7-fold, respectively). In hyperglycemic animals (treated with STZ), no influence on tumor growth was found in comparison with the controls. CONCLUSION: This study confirms that hyperinsulinemic conditions contribute to the progression of tumors.
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Andreas Mueller, Theodoros Maltaris, Arno Dimmler, Inge Hoffmann, Matthias W Beckmann, Ralf Dittrich (2005)  Development of sex cord stromal tumors after heterotopic transplantation of cryopreserved ovarian tissue in rats.   Anticancer Res 25: 6B. 4107-4111 Nov/Dec  
Abstract: Chemoradiotherapy has substantially improved life expectancy in young women with cancer, but these treatments often cause infertility. One method of preserving fertility is to cryopreserve ovarian tissue, with subsequent autotransplantation of the tissue after successful anticancer therapy. This study examined the long-term effect of heterotopic transplantation of cryopreserved ovarian tissue on the histology. Ovarian tissue from rats was cryopreserved using a slow-freezing protocol. After thawing, the tissue pieces were transplanted under the splenic capsule in 14 rats of the same inbred strain and remained there for 210 or 300 days. Sex cord stromal tumors, consisting mainly of granulosa cells, were found in all of the rats. Although the hormonal situation in rats cannot be directly compared to that in humans, the development of sex cord stromal tumors in this animal model may be worth considering when cryopreserved ovarian tissue is transplanted heterotopically in fertility-preserving programs for cancer patients.
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PMID 
Theodoros Maltaris, Fortunato Scalera, Dietmar Schlembach, Inge Hoffmann, Andreas Mueller, Helge Binder, Tamme Goecke, Torsten Hothorn, Ralf L Schild, Matthias W Beckmann, Ralf Dittrich (2005)  Increased uterine arterial pressure and contractility of perfused swine uterus after treatment with serum from pre-eclamptic women and endothelin-1.   Clin Sci (Lond) 109: 2. 209-215 Aug  
Abstract: The present study was designed to examine the effects of ET-1 (endothelin-1) and serum from PE (pre-eclamptic), HP (healthy pregnant) and HNP (healthy non-pregnant) women on uterine arterial perfusion pressure and uterine contractility. Swine uteri (n = 25) were perfused for a period of up to 11 h, with the aim being to preserve a viable organ. Various concentrations of ET-1 as well as serum from PE, HP and HNP women (n = 10 per group) were administered to the perfused swine uteri and IUP (intrauterine pressure) and IAP (intra-arterial pressure) were recorded. ET-1 produced dose-dependent increases in IUP and IAP. The ET-1 concentration in serum was higher in serum from PE women than in HP and HNP women (P > 0.05). Administration of all serum samples had a contractile effect on the swine uterus, with the greatest effect being seen in HNP women (12.8 +/- 5.3 mmHg), followed by PE (9.06 +/- 4.2 mmHg) and HP (6.1 +/- 4.1 mmHg) women. Statistically significant differences were observed between HNP and PE women (P = 0.048), and PE and HP women (P = 0.021). Increases in IAP following administration of serum from PE women (48.8 +/- 20.0 mmHg) were significantly higher (P = 0.024) compared with the effect of serum from HP women (28.4 +/- 13.7 mmHg). In conclusion, the findings show that serum from PE women has significant vasoconstrictive and oxytocic effects compared with serum from HP women. In pre-eclampsia, the balance between vasorelaxing and vasoactive substances is disturbed.
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T Maltaris, A Dimmler, A Müller, H Binder, I Hoffmann, J Kohl, E Siebzehnrübl, M W Beckmann, R Dittrich (2005)  The use of an open-freezing system with self-seeding for cryopreservation of mouse ovarian tissue.   Reprod Domest Anim 40: 3. 250-254 Jun  
Abstract: Chemoradiotherapy in young women with cancer has substantially improved life expectancy in these patients, but these treatments often cause infertility. One method of preserving fertility is to cryopreserve ovarian tissue. In this study, an automatic open-vessel freezing system with self-seeding was tested for cryopreservation of murine ovarian tissue; the mouse is a species widely used in human and veterinary medical research. The freezing system concerned, is used for cryopreservation of oocytes and embryos in Europe. Twenty severe combined immunodeficiency (SCID) mice were ovariectomized. The ovarian tissue was either directly transplanted heterotopically into the neck muscle (group 1, n = 6) or cryopreserved after equilibration with 1.5 M dimethylsulphoxide and propanediol. After thawing, the tissue was transplanted in SCID mice (group 2, n = 6). Before and after thawing, a part of the ovarian tissue was examined with the LIVE/DEAD fluorescent viability staining. The count of follicles revealed intact (fresh 24.1%/thawed 21.7%), impaired (fresh 35.1%/thawed 35.4%), and dead follicles (fresh 40.8%/thawed 42.9%). The healthy follicular loss because of the cryopreservation was 10.0%. All recipient mice were killed after 3 weeks. Transplanted ovarian tissue was found macroscopically in all mice. Histological examination showed several growing follicles in all developmental phases in both groups of SCID mice [group 1 (fresh grafts): 315 +/- 76.3 (mean +/- SD); group 2 (cryopreserved grafts): 237 +/- 63.4]. These results demonstrate that the use of an open-freezing system allows the survival of cryopreserved mouse ovarian tissue.
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2004
 
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Ralf Dittrich, Charalampos Dragonas, Andreas Mueller, Theodoros Maltaris, Jan Rupp, Matthias W Beckmann, Matthias Maass (2004)  Endothelial Chlamydia pneumoniae infection promotes oxidation of LDL.   Biochem Biophys Res Commun 319: 2. 501-505 Jun  
Abstract: The bacterium Chlamydia pneumoniae chronically infects atheromatous lesions and is linked to atherosclerosis by modifying inflammation, proliferation, and the lipid metabolism of blood monocytes. As continuous LDL modification in the vascular intima is crucial for atherogenesis we investigated the impact of endothelial infection on LDL oxidation. HUVEC were infected with a vascular C. pneumoniae strain. Supernatants of infected cells but not cell lysates increased lipid peroxidation products (6.44 vs 6.14 nmol/ml, p<0.05) as determined by thiobarbituric acid reacting substances assay. Moreover, supernatants rendered human LDL more susceptible to oxidation as shown in a copper-ion catalysed LDL oxidation assay by a 16% reduction of LDL resistance against pro-oxidative stimuli (p<0.05). Chlamydial infection of vascular endothelial cells releases acellular components that convert LDL to its proatherogenic form and reduce its resistance against oxidation. Foci of chronic endothelial chlamydial infection may thus continuously contribute to the dysregulated lipid metabolism that promotes atherogenesis.
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2003
 
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R Dittrich, T Maltaris, A Müller, C Dragonas, F Scalera, M W Beckmann (2003)  The extracorporeal perfusion of swine uterus as an experimental model: the effect of oxytocic drugs.   Horm Metab Res 35: 9. 517-522 Sep  
Abstract: The objective of this study was to establish an experimental model for extracorporeal perfusion of swine uterus. In order to validate this model, we examined some biochemical parameters and determined the effect of oxytocic drugs (Oxytoxin, Prostaglandin E (2)) on extracorporeal perfused swine uteri. Thirty swine uteri were perfused with Krebs-Ringer bicarbonate-glucose buffer for a period up to eleven hours with the aim to preserve a viable organ, which should be responsive to hormones. The intrauterine pressure was recorded after administration of various concentrations of oxytocin and prostaglandin E (2). Perfusate pH, perfusate lactate, partial oxygen and carbon dioxide tensions, oxygen saturation, and hydrogencarbonate levels in the perfusate, all indicators of tissue ischemia or cell necrosis, showed good preservation of the organ for up to seven hours. We examined the relation of intrauterine pressure to oxytocin and prostaglandin E (2). Both were able to induce contractions of the uterus, whereas prostaglandin E (2) produced rhythmical contractions of smaller amplitude and a higher frequency. We could demonstrate that our perfusion system was able to preserve the swine uterus in a functional condition appropriate for the study of physiological questions.
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