Effect of retinoic acid on type I diabetes: Streptozotocin-induced rat model

To evaluate the effect of all trans retinoic acid [atRA] on differentiation/transdifferentiation of pancreatic duct/acinar cells into insulin secreting beta-cells in diabetic rats. 64 adult male rats divided into four groups. Normal control, diabetic control, atRA-I: diabetic rats treated with atRA [0.1 mg/kg/day, subcutaneously] and atRA-II: diabetic rats treated with atRA [2.5 mg/kg/day, subcutaneously] for 1, 2 and 4 weeks. The levels of glucose and insulin were measured. Histopathological, immunohistochemical examination of pancreas and RT-PCR of insulin mRNA were done. atRA led to an improvement in the level of glucose and insulin in both doses and at the different time points when compared with diabetic control. Histopathological examination of the pancreas revealed that atRA in both doses and at different time points nearly restored the normal appearance of the islets of Langerhans. Interestingly, some islets of Langerhans were found closely related to the interlobular ducts and the acinar epithelium. Mitotic figures were observed in the epithelium of the interlobular ducts and acinar cells and inside the islets of Langerhans especially with high dose. The immunohistochemical revealed strong insulin-immunoreactivity in the cytoplasm of the beta-cells and in the cytoplasm of the isolated cells which are closely related to the acini. Also, insulin mRNA expression showed dense band illumination similar to normal control. Retinoic acid may induced significant increase in insulin level and its mRNA, decrease glucose level and increased beta-cells regeneration through increased pancreatic duct and/or acinar cells differentian/transdifferentiation and increased proliferation of fbeta-cells in diabetic rats

Serum adiponectin in newborns and in one and two years old infants: relationship with body weight, leptin and insulin

Adiponectin is the only adipose-specific hormone that, despite its exclusive production by adipose tissue, is reduced in obesity and is inversely correlated with leptin levels in adults. It plays a critical role in the control of energy balance in adult life. However, its functions and relations to other hormones are not yet fully understood in infants. The aim of this study is to assess adiponectin levels in newborns at birth, one and two years of life and to define its association with weight, serum leptin and insulin. Serum adiponectin, leptin and insulin levels were investigated in 48 newborns [24 small for gestational age [SGA] and 24 appropriate for gestational age [A GA]]. Infants aged one year [n=20] and two years [n=20] were also included in this study. The levels of serum adiponectin were significantly decreasing while serum leptin and insulin were significantly increasing at one and two years. Serum adiponectin was correlated positively with weight [r=0.509, p<0.001] and leptin [r=0.355, p<0.05] but not correlated with serum insulin in all newborns. At one and two years adiponectin was correlated positively with insulin [r=0.444, p<0.05 and r0.448, p<0.05 respectively]. The correlation between adiponectin and weight at one year [r=-0.056, p=0.816] and between it and leptin at two years [r=-0.171, p=0.471] changed into negative but did not reach a statistically significant level. Serum leptin was correlated positively with weight in all newborns [r=0.935, p<0.001]. At two years it was positively correlated with weight [r=0. 721, p<0.001] and insulin [r=0.641, p<0.01]. Serum adiponectin and leptin levels were significantly lower in SGA than AGA infants [30.08 +/- 9.54 micro/ml and 4.33 +/- 3.20 microg/L, p<0.001 respectively] but there was no difference in serum insulin. In conclusion, adiponectin is higher in newborns than at one and two years. The change in correlation of adiponectin with weight and leptin from positive in newborns to negative in adults might occur at the first 2 years of life

study of serum zinc, copper and thyroid hormones in children with chronic renal failure

The study included 21 patients [13 males and 8 females, aged from 9-17ys] with chronic renal failure [CRF] on regular hemodialysis. In addition, 10 apparently healthy age-matched children were included as a control group. Serum levels of zinc [Zn], copper [Cu], tri-iodothyronine [T[3]], thyroxin [T[4]], thyroid stimulating hormone [TSH] and creatinine were measured in all studied cases and controls. Serum levels of Zn and Cu were significantly lower among the studied cases [96.76 +/- 41.4 micro g/dl and 82.33 +/- 16.4 micro g/dl, respectively], compared with the controls [134.4 +/- 43 micro g/dl and 100.2 +/- 14.4 micro g/dl respectively], p<0. 05 and p<0.01 respectively. As regards the studied thyroid hormones and TSH, the studied cases showed significant lower serum T[3] level [61.85 +/- 9.7 nano g/dI] compared with the control group [85.80 +/- 4.26 nano g/dl], p< 0.001. While no significant statistical differences were found between the studied cases and controls regarding T[4] and TSH serum level. On the other hand, the mean value of T[3]/T[4] ratio was significantly lower among studied patients [12.91 +/- 1.87] in comparison with the controls [16.23 +/- 2.63], p<0.001. Additionally, a significant positive correlation was found between T[3] and T[4] [r=0.645, p<0.01]. Serum Zn exhibited also positive significant correlation with T[3] and T[4] [r=-0.506 and r=0 .514 respectively], p<0.05 for each. However, no significant correlation was detected between serum Cu levels and thyroid hormones. In conclusion; patients with CRF had low levels of serum Zn and Cu. They may have a state of subclinical hypothyroidism. The significant decrease in the mean value of serum T[3] level, the insignificant decrease in the mean value of serum T[4] level, the significant low T[3]/T[4] ratio as well as the significant positive correlation between serum Zn and T[3] may reflect impaired peripheral conversion of T[4] to T[3] due to Zn deficiency