OBJECTIVE: The objective of this study was to determine the effects of T3 derivatives, σ-T3, γ-T3 and α-T3 on insulin secretion of rat pancreatic islets in a dynamic culture.
METHOD: Pancreatic islets isolated from male Wistar rats were treated with T3 for 1 h at 37°C in a microfluidic system with continuous operation that provided a stable cell culture environment. Glucose (2.8 mM and 16.7 mM, as basal and stimulant, respectively) and potassium chloride (KCl) (30 mM) were added to the treatment in calcium free medium. The supernatant was collected for insulin measurements.
RESULTS: Short-term exposure (1 h) of σ-T3 to β cells in the stimulant glucose condition significantly potentiated insulin secretion in a dose-dependent manner. γ-T3 and α-T3 also displayed dosedependent effect but were less effective in the activation of insulin secretion. Essentially, KCl, a pancreatic β cell membrane depolarizing agent, added into the treatment further enhanced the insulin secretion of σ-T3, γ-T3 and α-T3 with ED50 values of 504, 511 and 588 µM, respectively.
CONCLUSION: The findings suggest the potential of σ-T3 in regulating glucose-stimulated insulin secretion (GSIS) in response to the intracellular calcium especially in the presence of KCl.
OBJECTIVE: To investigate prevalence and predictors of PREM defined by IDAA1c.
METHODS: Six hundred fourteen of 678 children (aged <15 years) with new-onset T1D (2000-2013) from a regional pediatric diabetes service (Auckland, New Zealand).
RESULTS: Overall rate of PREM at 3 months was 42.4%, and lower in Māori/Pacific children (28.6%; P = .006) and those of other ethnicities (28.8%; P = .030) compared with New Zealand Europeans (50.4%). Comparing the most and least deprived socioeconomic quintiles, the odds of PREM were lower among the most deprived (adjusted odds ratio [aOR] 0.44; P = .019). Lower rates of PREM were seen in children aged 0 to 4.9 years (23.8%) and 10 to 14 years (40.9%) than in children aged 5 to 9.9 years (57.4%; P
OBJECTIVE: This review aims to assess the current evidence of the bone-sparing effects of vitamin C derived from cell, animal and human studies.
RESULTS: Cell studies showed that vitamin C was able to induce osteoblast and osteoclast formation. However, high-dose vitamin C might increase oxidative stress and subsequently lead to cell death. Vitamin C-deficient animals showed impaired bone health due to increased osteoclast formation and decreased bone formation. Vitamin C supplementation was able to prevent bone loss in several animal models of bone loss. Human studies generally showed a positive relationship between vitamin C and bone health, indicated by bone mineral density, fracture probability and bone turnover markers. Some studies suggested that the relationship between vitamin C and bone health could be U-shaped, more prominent in certain subgroups and different between dietary and supplemental form. However, most of the studies were observational, thus could not confirm causality. One clinical trial was performed, but it was not a randomized controlled trial, thus confounding factors could not be excluded.
CONCLUSION: vitamin C may exert beneficial effects on bone, but more rigorous studies and clinical trials should be performed to validate this claim.
MATERIALS AND METHODS: Rats were exposed to d-gal 60 mg/kg/b.wt/day + AlCl3 200 mg/kg/b.wt/day and CA (200, 400 and 800 mg/kg/b.wt/day) and 1 mg/kg/b.wt/day of donepezil for 70 days. Different cognitive paradigms viz. T maze spontaneous alternation, modified elevated plus maze and novel object recognition test, were used to evaluate full lesions of the hippocampus, spatial learning and memory and non-spatial learning and memory respectively. Nissl's staining was used to determine the survival of hippocampus CA1 pyramidal cells, while transmission electron microscopy was used to check the ultrastructural changes.
RESULTS: The results revealed that d-gal and AlCl3 could significantly impair behavior and cognitive functions, besides causing damage to the hippocampal CA1 pyramidal neurons in rats. In addition, it also caused ultrastructural morphological alterations in rat hippocampus. Conversely, co-administration o;f CA, irrespective of the dosage used, alleviated the cognitive impairments and pathological changes in the rats comparable to donepezil.
CONCLUSION: In conclusion the results suggest that CA could protect cognitive impairments and morphological alterations caused by d-gal and AlCl3 toxicity in rats. Biochemical and molecular studies are ongoing to elucidate the probable pharmacodynamics of CA.