Maple syrup urine disease: mutation analysis in Turkish patients

Maple syrup urine disease (MSUD), the most frequently occurring organic acidaemia in Turkey, is caused by a deficiency of the activity of branched-chain keto acid dehydrogenase enzyme (BCKAD) complex. Mutation analysis of the E1, E1, and E2 genes of the BCKAD complex in 12 Turkish MSUD patients yielded three disease-specific mutations and a polymorphism in the E1 gene, none in the E1 gene and one mutation in the E2 gene. Among them, three missense mutations (Q80E, C213Y, T106M) and the F280F polymorphism occurring in the E1 gene and the splice site mutation (IVS3 – 1G > A) in the E2 gene were novel. Three of the missense mutations and the splicing mutation occurred homozygously and caused classical MSUD. One patient carried the splicing mutation homozygously and the T106M mutation in the heterozygous state; this patient is the first case having simultaneously two different mutations in two different genes in the BCKAD complex. IVS3 – 1G > A splicing mutation detected on the E2 gene causes deletion of the first 14 bp of exon 3 in the mutant mRNA extending between 190 and 204 nt. The deletion spans the cleavage point between mitochondrial targeting and lipoyl-bearing site of the E2 protein.     

Transmission electron microscopy and autofluorescence findings in the cornea of diabetic rats treated with aminoguanidine

BACKGROUND: The accumulation of advanced glycation end products (AGEs) has been implicated in the pathogenesis of diabetic keratopathy. The present study was aimed to understand if aminoguanidine (AG), an AGE inhibitor, was protective against the development of corneal complications in a diabetic rat model. METHODS: Wistar rats were divided into three experimental groups: control, diabetic, and AG-treated diabetic. Diabetes was induced in rats via a single intraperitoneal injection (60 mg/kg) of streptozocin (STZ) and AG was administered in drinking water at a dose of 1 g/L. All animals were sacrificed at the end of 10 weeks and corneas from diabetic and nondiabetic rats were analyzed via transmission electron microscopy (TEM). Corneal autofluorescence measurements were also performed in all experimental groups. RESULTS: Electron microscopic evaluation revealed that aminoguanidine treatment in diabetic rats prevented the formation of intracellular spaces between neighbouring cells in the superficial corneal epithelium. Hyperglycemia-induced degeneration of intracellular organelles and formation of cytoplasmic vacuoles in the corneal stroma was also prevented with the treatment of AG. Corneal autofluorescence detected in the diabetic group (5.98 +/- 2.17 Fi/mg protein) was found to be significantly greater than the control (3.92 +/- 0.56 Fi/mg protein) and the AG-treated diabetic group (4.18 +/- 0.59 Fi/mg protein) (p < 0.05). INTERPRETATION: The presented data provide evidence that AG is preventive against corneal alterations in experimental diabetes.     

Role of glyceryl trinitrate, a nitric oxide donor, in the renal ischemia-reperfusion injury of rats

BACKGROUND/AIMS: Ischemia-reperfusion injury is a serious clinical situation which can cause serious morbidity and mortality. An experimental renal ischemia-reperfusion injury model was designed to evaluate the role of glyceryl trinitrate (GTN) on renal function and histology. METHODS: 50 Wistar albino rats were used in our study. Five groups were formed: (1) sham-control group; (2) acute renal ischemia (ARI) group with placebo (0.9% NaCl) infusion; (3) GTN infusion with a 75 microg/kg/min dose prior to ARI was administered; (4) GTN infusion with a 150 microg/kg/min dose prior to ARI was given, and finally (5) 150 microg/kg/min GTN infusion after the ARI period was applied. Serum BUN and creatinine levels were measured for evaluation of renal function. T(max-sec), glomerular filtration rate (GFR), and T(max-min) results following a (99m)Tc-DTPA diuretic renal scintigraphy were used. Histological examination was performed on nephrectomy specimens. RESULTS: Groups 2 and 5 showed higher BUN, creatinine, and lower GFR values than the other groups (p = 0.0001). There was no difference in BUN, creatinine, and GFR levels between groups 2 and 5 (p = 0.971, p = 0.739, p = 0.393). Also the T(max-sec) values were higher in groups 2 and 5 compared with the other groups (p = 0.0001). The presence of tubular necrosis was different between groups and was higher in groups 2 and 5 (p = 0.002). CONCLUSION: The application of GTN, a nitric oxide donor, has caused significant improvement in renal function when applied prior to an experimentally designed renal ischemia-reperfusion model. But administration of GTN had no effect after occurrence of ischemia.     

Mixed serous and endometrioid carcinoma of the fallopian tube: a case report with literature review

Malignant neoplasms of the fallopian tube are the rarest of the gynecologic cancers. The frequency of histologic subtypes has been difficult to ascertain from the literature because most authors have not classified these tumors according to their cell types. Papillary serous adenocarcinoma appears to be the most common histologic type. On the contrary, mixed cell types of fallopian tube carcinoma have rarely been reported in the literature. A case of mixed serous and endometrioid carcinoma of the fallopian tube is presented and the related literature is reviewed.     

Cooling and response to hydrogen peroxide in human saphenous vein: role of the endothelium

In the present work we studied the responses of human saphenous vein to H2O2 and effects of moderate cooling on these responses with analysis of the role of endothelium. H2O2 (10(-7)-10(-2) M) induced concentration-dependent contraction in the intact human saphenous vein strips at both temperatures. At 28 degrees C, the maximal contraction induced by H2O2 was significantly lower than that at 37 degrees C. Compared with intact strips, the sensitivity and the maximal contraction to H2O2 were significantly enhanced in endothelium-denuded strips at 37 and 28 degrees C. However, pD2 values and maximal contractions were not significantly different in endothelium-denuded strips at different temperatures. Pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME) increased significantly the maximal contraction and sensitivity to H2O2 at 37 and 28 degrees C. The contractions increased by L-NAME were restored by the pre-incubation of l-arginine (10(-3) M) at every temperature studied. The contractile responses of intact human saphenous veins to H2O2 were reduced significantly by 10(-5) M indomethacin at both temperatures. Our results suggest that H2O2-induced contraction of human saphenous vein are mediated by its direct effect on the smooth muscle and by the generation of products of the cyclooxygenase pathway from the endothelium. Signalling pathways of these contractile effects are the same at 37 and 28 degrees C. Under normal temperature conditions, the contraction to H2O2 is possibly modulated by endothelial nitric oxide. Cooling reduces the contraction to H2O2 by increasing release of nitric oxide.