Tunku Kamarul Zaman

Abstract: The use of mesenchymal stem cells (MSCs) for cartilage repair has generated much interest owing to their multipotentiality. However, their significant presence in peripheral blood (PB) has been a matter of much debate. The objectives of this study are to isolate and characterize MSCs derived from PB and, compare their chondrogenic potential to MSC derived from bone marrow (BM). PB and BM derived MSCs from 20 patients were isolated and characterized. From 2 ml of PB and BM, 5.4 ± 0.6 million and 10.5 ± 0.8 million adherent cells, respectively, were obtained by cell cultures at passage 2. Both PB and BM derived MSCs were able to undergo tri-lineage differentiation and showed negative expression of CD34 and CD45, but positively expressed CD105, CD166, and CD29. Qualitative and quantitative examinations on the chondrogenic potential of PB and BM derived MSCs expressed similar cartilage specific gene (COMP) and proteoglycan levels, respectively. Furthermore, the s-GAG levels expressed by chondrogenic MSCs in cultures were similar to that of native chondrocytes. In conclusion, this study demonstrates that MSCs from PB maintain similar characteristics and have similar chondrogenic differentiation potential to those derived from BM, while producing comparable s-GAG expressions to chondrocytes.

Abstract: Mesenchymal stem cells (MSCs) represent a promising alternative form of cell-based therapy for cartilage injury. However, the capacity of MSCs for chondrogenesis has not been fully explored. In particular, there is presently a lack of studies comparing the effectiveness of MSCs to conventional autologous chondrocyte (autoC) treatment for regeneration of full-thickness cartilage defects in vivo.

Abstract: SummaryBody mass index (BMI) is a good indicator of nutritional status in a population. In underdeveloped countries like Bangladesh, this indicator provides a method that can assist intervention to help eradicate many preventable diseases. This study aimed to report on changes in the BMI of married Bangladeshi women who were born in the past three decades and its association with socio-demographic factors. Data for 10,115 married and currently non-pregnant Bangladeshi women were extracted from the 2007 Bangladesh Demographic and Health Survey (BDHS). The age range of the sample was 15-49 years. The mean BMI was 20.85±3.66 kg/m2, and a decreasing tendency in BMI was found among birth year cohorts from 1972 to 1992. It was found that the proportion of underweight females has been increasing in those born during the last 20 years of the study period (1972 to 1992). Body mass index increased with increasing age, education level of the woman and her husband, wealth index, age at first marriage and age at first delivery, and decreased with increasing number of ever-born children. Lower BMI was especially pronounced among women who were living in rural areas, non-Muslims, employed women, women not living with their husbands (separated) or those who had delivered at home or non-Caesarean delivery.

Abstract: Grip strength is an important measure used to monitor the progression of a condition, and to evaluate outcomes of treatment. We assessed how various physical and social factors predict normal grip strength in an adult Malaysian population of mixed Asian ethnicity (254 men, 246 women). Grip strength was recorded using the Jamar dynamometer. The mean grip strength for the dominant hand was 29.8 kg for men and 17.6 kg for women. Multiple regression analysis demonstrated that the dominant hand grip strength was positively associated with height and body mass index, and negatively associated with age for both sexes. Dominant hand grip strength was related to work status for men (p < 0.05) but not for women. However, there was no difference in grip strength among ethnic groups.

Abstract: Understanding the pathomechanics involved in rheumatoid arthritis (RA) of the wrist provides valuable information, which will invariably allow various therapeutic possibilities to be explored. The computational modelling of this disease permits the appropriate simulation to be conducted seamlessly. A study that underpins the fundamental concept that produces the biomechanical changes in a rheumatoid wrist was thus conducted through the use of finite element method. The RA model was constructed from computed tomography datasets, taking into account three major characteristics: synovial proliferation, cartilage destruction and ligamentous laxity. As control, a healthy wrist joint model was developed in parallel and compared. Cartilage was modelled based on the shape of the articulation while the ligaments were modelled with linear spring elements. A load-controlled analysis was performed simulating physiological hand grip loading conditions. The results demonstrated that the diseased model produced abnormal wrist extension and stress distribution as compared to the healthy wrist model. Due to the weakening of the ligaments, destruction of the cartilage and lower bone density, the altered biomechanical stresses were particularly evident at the radioscaphoid and capitolunate articulations which correlate to clinical findings. These results demonstrate the robust finding of the developed RA wrist model, which accurately predicted the pathological process.

Abstract: The use of mesenchymal stem cells (MSCs) in tissue repair and regeneration despite their multipotentiality has been limited by their cell source quantity and decelerating proliferative yield efficiency. A study was thus undertaken to determine the feasibility of using microcarrier beads in spinner flask cultures for MSCs expansion and compared to that of conventional monolayer cultures and static microcarrier cultures. Isolation and characterization of bone marrow derived MSCs were conducted from six adult New Zealand white rabbits. Analysis of cell morphology on microcarriers and culture plates at different time points (D0, D3, D10, D14) during cell culture were performed using scanning electron microscopy and bright field microscopy. Cell proliferation rates and cell number were measured over a period of 14 days, respectively followed by post-expansion characterization. MTT proliferation assay demonstrated a 3.20 fold increase in cell proliferation rates in MSCs cultured on microcarriers in spinner flask as compared to monolayer cultures (p < 0.05). Cell counts at day 14 were higher in those seeded on stirred microcarrier cultures (6.24 ± 0.0420 cells/ml) × 10(5) as compared to monolayer cultures (0.22 ± 0.004 cells/ml) × 10(5) and static microcarrier cultures (0.20 ± 0.002 cells/ml) × 10(5). Scanning electron microscopy demonstrated an increase in cell colonization of the cells on the microcarriers in stirred cultures. Bead-expanded MSCs were successfully differentiated into osteogenic and chondrogenic lineages. This system offers an improved and efficient alternative for culturing MSCs with preservation to their phenotype and multipotentiality.

Abstract: Human amniotic membrane (HAM) is an established biomaterial used in many clinical applications. However, its use for tissue engineering purposes has not been fully realized. A study was therefore conducted to evaluate the feasibility of using HAM as a chondrocyte substrate/carrier. HAMs were obtained from fresh human placenta and were process to produced air dried HAM (AdHAM) and freeze dried HAM (FdHAM). Rabbit chondrocytes were isolated and expanded in vitro and seeded onto these preparations. Cell proliferation, GAG expression and GAG/cell expression were measured at days 3, 6, 9, 12, 15, 21, and 28. These were compared to chondrocytes seeded onto plastic surfaces. Histological analysis and scanning electron microscopy was performed to observe cell attachment. There was significantly higher cell proliferation rates observed between AdHAM (13-51%, P=0.001) or FdHAM (18-48%, p = 0.001) to chondrocytes in monolayer. Similarly, GAG and GAG/cell expressed in AdHAM (33-82%, p = 0.001; 22-60%, p = 0.001) or FdHAM (41-81%, p = 0.001: 28-60%, p = 0.001) were significantly higher than monolayer cultures. However, no significant differences were observed in the proliferation rates (p = 0.576), GAG expression (p = 0.476) and GAG/cell expression (p = 0.135) between AdHAM and FdHAM. The histology and scanning electron microscopy assessments demonstrates good chondrocyte attachments on both HAMs. In conclusion, both AdHAM and FdHAM provide superior chondrocyte proliferation, GAG expression, and attachment than monolayer cultures making it a potential substrate/carrier for cell based cartilage therapy and transplantation.

Abstract: The use of bicortical screws to fix metacarpal fractures has been suggested to provide no added biomechanical advantage over unicortical screw fixation. However, this was only demonstrated in static loading regimes, which may not be representative of biological conditions. The present study was done to determine whether similar outcomes are obtained when cyclic loading is applied. Transverse midshaft osteotomies were created in 20 metacarpals harvested from three cadavers. Fractures were stabilised using 2.0 mm mini fragment plates fixed with either bicortical or unicortical screw fixation. These fixations were tested to failure with a three-point bending cyclic loading protocol using an electromechanical microtester and a 1 kN load cell. The mean load to failure was 370 N (SD 116) for unicortical fixation and 450 N (SD 135) for bicortical fixation. Significant differences between these two constructs were observed. A biomechanical advantage was found when using bicortical screws in metacarpal fracture plating.

Abstract: The use of open wedge high tibial osteotomy (HTO) to correct varus deformity of the knee is well established. However, the stability of the various implants used in this procedure has not been previously demonstrated. In this study, the two most common types of plates were analysed (1) the Puddu plates that use the dynamic compression plate (DCP) concept, and (2) the Tomofix plate that uses the locking compression plate (LCP) concept. Three dimensional model of the tibia was reconstructed from computed tomography images obtained from the Medical Implant Technology Group datasets. Osteotomy and fixation models were simulated through computational processing. Simulated loading was applied at 60:40 ratios on the medial:lateral aspect during single limb stance. The model was fixed distally in all degrees of freedom. Simulated data generated from the micromotions, displacement and, implant stress were captured. At the prescribed loads, a higher displacement of 3.25mm was observed for the Puddu plate model (p<0.001). Coincidentally the amount of stresses subjected to this plate, 24.7MPa, was also significantly lower (p<0.001). There was significant negative correlation (p<0.001) between implant stresses to that of the amount of fracture displacement which signifies a less stable fixation using Puddu plates. In conclusion, this study demonstrates that the Tomofix plate produces superior stability for bony fixation in HTO procedures.

Abstract: Secular changes in the head and body dimensions of the Japanese population were recorded during the last century, but studies on Japanese adult facial shape were poorly documented. This study aimed to document the secular changes in facial shape and their association with craniofacial measures of Japanese adult female students.