Distribution of heavy metals in surface sediments from the South China Sea ecosystem, Malaysia

The concentrations of arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc in surface sediments collected from the east coast of peninsular Malaysia, along the South China Sea, were measured by two methods instrumental neutron activation analysis and inductively coupled plasma mass spectroscopy. The obtained results were use to determine the areal distribution of the metals of in the east coast of peninsular Malaysia and potential sources of these metals to this environment. The geochemical data propose that most of the metals found in the east coast of peninsular Malaysia constitute a redistribution of territorial materials within the ecosystem. Then, the metal concentrations can be considered to be present at natural background levels in surface sediments

Study of chondrogenic potential of stem cells in co-culture with chondrons

Objective(s): Three-dimensional biomimetic scaffolds have widespread applications in biomedical tissue engineering due to similarity of their nanofibrous architecture to native extracellular matrix. Co-culture system has stimulatory effect on chondrogenesis of adult mesenchymal stem cells. This work presents a co-culture strategy using human articular chondrons and adipose-derived stem cells (ASCs) from infrapatellar fat pad (IPFP) for cartilage tissue production. Materials and Methods: Isolated stem cells were characterized by flowcytometry. Electrospun and polycaprolactone (PCL) scaffolds (900 nm fiber diameter) was obtained from Bon Yakhteh (Tehran- Iran) and human infrapatellar fat pad-derived stem cells (IPFP-ASCs) were seeded on them. IPFP- ASCs on scaffolds were co-cultured with articular chondrons using transwell. After 21 day, chondrogenic differentiation of stem cell was evaluated by determining the genes expression of collagen2, aggrecan and Indian hedgehog using real- time RT-PCR. Results: Genes expression of collagen2, aggrecan by IPFP-ASCs did not alter significantly in comparison with control group. Howevers, expression of Indian hedgehog decreased significantly compared to control group (P˂ 0.05). Conclusion: These findings indicate that chondrons obtained from osteoarthritic articular cartilage did not stimulate chondrogenic differentiation of IPFP-ASCs in co-culture

Vitamin D deficiency and causative factors in the population of Tehran

<p>Abstract</p> <p>Background</p> <p>There are multiple studies in different countries regarding the prevalence of vitamin D deficiency. These studies showed high prevalence of vitamin D deficiency in Asian countries. This study tries to elucidate the prevalence of vitamin D deficiency and its influencing factors in population of Tehran.</p> <p>Methods</p> <p>1210 subjects 20–64 years old were randomly selected. 25 (OH) D serum levels were measured. Duration of exposure to sunlight, the type of clothing and level of calcium intake and BMI were quantified based on a questionnaire.</p> <p>Results</p> <p>A high percentage of vitamin D deficiency was defined in the study population. Prevalence of severe, moderate and mild Vitamin D deficiency was 9.5%, 57.6% and 14.2% respectively. Vitamin D serum levels had no significant statistical relation with the duration of exposure to sunlight, kind of clothing and BMI. Calcium intake in the normal vitamin D group was significantly higher than the other groups (714.67 ± 330.8 mg/day vs 503.39 ± 303.1, 577.93 ± 304.9,595.84 ± 313.6). Vitamin D serum levels in young and middle aged females were significantly lower than the older group.</p> <p>Conclusions</p> <p>Vitamin D deficiency has a high prevalence in Tehran. In order to avoid complications of vitamin D deficiency, supplemental dietary intake seems essential.</p