MITOMYCIN -C AUGMENTED TRABECO -LECTOMY IN REFRACTORY DEVELOP-MENTAL GLAUCOMA: LONG-TERM RE-SULTS WITH DIFFERENT CONCENTRA-TIONS

Purpose: To evaluate the long term results of trabeculectomy with different concentrations of Mitomycin-C (MMC) in refractory developmental glaucoma Materials and Methods: A total 48 eyes of 37 patients with refractory developmental glaucoma who underwent MMC augmented trabeculectomy between December 1994 and October 2000 were included in the study. The patients were divided into four groups. Group 1 (13 eyes) and Group 2(12 eyes) consisted of patients younger than 24 months of age,     

Effects of L-arginine and L-carnitine in hypoxia/reoxygenation-induced intestinal injury

BACKGROUND: This study was designed to show the role of oxidative stress, nitric oxide and glutathione-related antioxidant enzymes in hypoxia/reoxygenation (H/R)-induced intestinal injury model in mice and to evaluate the potential benefits of arginine and carnitine supplementation. METHODS: A total of 28 young Balb/c mice were divided into four groups: Group 1 (untreated) was given physiological saline before the experiment; group 2 H/R mice were supplemented with L-arginine; group 3 H/R mice were given L-carnitine for 7 days; and group 4 mice served as controls. At the end of day 7, H/R injury was induced and intestinal tissue malondialdehyde (MDA), nitrate levels and glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were measured. RESULTS: MDA levels were higher in the untreated animals than in the other three groups. MDA levels were higher in the L-arginine-treated animals than in the L-carnitine-treated animals. Nitrate levels were found to be increased in the L-arginine-treated group when compared to the controls. GSH-Px and GR activities were increased in the untreated, the L-arginine and the L-carnitine-treated H/R groups when compared to the control group. GST activities were indifferent between the groups. CONCLUSIONS: Oxidative stress contributes to the pathogenesis of H/R-induced intestinal injury. The glutathione redox cycle may have a crucial role in the H/R-induced intestinal injury. L-arginine and L-carnitine supplementations ameliorate the histological evidence of H/R-induced intestinal injury and decrease lipid peroxidation but do not alter the glutathione-related antioxidant enzyme activities.     

Assessment of the use of hip ultrasonography by Graf's method between 1 and 6 years of age

Ultrasonographic examinations of both hips of 133 children whose age ranged from 13 to 72 months were performed using the Graf's method. A standard plane which was mandatory prior to the hip typing could be obtained in 93, 91, 84, 79 and 66% of the sonograms for 13-24, 25-36, 37-48, 49-60 and 61-72 months age groups, respectively. The 61-72 months age group had the lowest percentage of valid sonograms and this difference was considered significant (P=0.001). It was concluded that plain radiography was still the gold standard imaging technique in developmental dysplasia of the hip, but hip ultrasonography by the Graf's method might be an alternative imaging technique in experienced hands for the evaluation of developmental dysplasia of the hip in children between 1 and 5 years of age.     

Microvascular blood flow of the optic nerve head and peripapillary retina in unilateral exfoliation syndrome

PURPOSE: To measure microvascular blood flow in patients with unilateral exfoliation syndrome (XFS) without glaucoma or ocular hypertension and to compare the values in the eyes with clinically detected exfoliation, their nonexfoliative fellow eyes of the same patients and control eyes. METHODS: Twenty-two patients with clinically detected unilateral XFS and 30 age-matched healthy subjects were included in this study. Group 1 consisted of 22 eyes with clinical XFS, and the nonexfoliative fellow eyes of the same patients formed Group 2. The control group (Group 3) comprised te randomly selected eyes of 30 age-matched healthy subjects. Ocular blood flow values (volume, flow and velocity) were recorded from the opti nerve head (ONH) and peripapillary retina (PPR) using the Heidelberg retinal flowmeter (HRF). The difference between the three groups were compared statistically. RESULTS: The mean values of blood flow obtained from the ONH and PPR in eyes with clinically detected exfoliation (Group 1) and their nonexfoliative fellow eyes (Group 2) were both significantly lower than the values for the control eyes (Group 3). The differences in ocular blood flow between the eyes with exfoliation and the nonexfoliative fellow eyes were not statistically significant [one-way analysis of variance (ANOVA), Dunnett's T3 test, p >/= 0.05]. CONCLUSION: These findings suggest that the eyes with clinically detected unilateral XFS were associated with reduced blood flow values in both the ONH and the PPR. The nonexfoliative fellow eyes also have lower blood flow values than the control eyes.     

Duplex sonography of retro-orbital and carotid arteries in patients with normal-tension glaucoma

PURPOSE: To evaluate retrobulbar and carotid arterial hemodynamics in patients with normal-tension glaucoma using Doppler sonography. MATERIALS AND METHODS: Duplex sonography was performed in 41 patients with normal-tension glaucoma and 30 control subjects to evaluate resistance indices (RIs) in retro-orbital and carotid arteries. Mean values were compared using the independent t-test. The ratios of the RI in retro-orbital to RIs in the carotid arteries (CCA and ICA) and interocular and intercarotid differences in RI (DeltaRI) were also calculated. RESULTS: Is in the central retinal (CRA) and temporal and nasal posterior ciliary arteries (TPCA and NPCA) were statistically significantly greater in glaucomatous eyes (p < 0.001). Plaque formation in carotid arteries without significant stenosis was noted in 12% of patients and 10% of control subjects. Ratios of RI of CRA or TPCA or NPCA to that of CCA and the ratios of RI of CRA or NPCA to that of ophthalmic arteries (OA) were significantly greater in glaucomatous eyes. We also found that ratios of the RI of CRA or TPCA or NPCA to that of ICA and the ratio of the RI of OA to CCA were nearly equal to 1 in both patients and control subjects. We found no significant difference between interocular and intercarotid DeltaRIs in patients and control subjects. CONCLUSIONS: In patients with symmetric normal-tension glaucoma, duplex sonography showed an elevated RI in CRA and PCA. The Doppler evaluation of carotid arteries was useful.     

Progressive ventricular enlargement in the absence of high ventricular pressure in an experimental neonatal rat model

OBJECT: In the present study, we compared ventricular pressures (VP) and the progression of ventricular enlargement in a new experimental neonatal hydrocephalus model, to gain an understanding of how communicating hydrocephalus progresses. METHODS: Kaolin was injected into the subarachnoid space at the cranial convexity of neonatal rats. Gross examination was performed on the 3rd, 5th and 7th days, and ultrasonographic examination on the 15th day, and at the end of the 1st and 2nd months following the kaolin application. Ventricular size indexes (VSI) were calculated in the case of a large ventricular dilatation. VPs were assessed on the 15th day, and at the end of the 1st and 2nd months, with a computerized data acquisition system. CONCLUSIONS: In the 1st and 2nd months VSIs were significantly higher than in control rats on the 15th day after kaolin administration. VP on the 15th day was significantly increased compared with that in control rats. VP in the 1st month was still high, but had subsided. In the 2nd month VP was not increased over control. In the late stages, the progression of infantile communicating hydrocephalus is not related to VP levels.     

Amlodipine and glutathione cycle in hypercholesterolaemia

OBJECTIVE: Effects of amlodipine on lipid peroxidation and alterations in glutathione and related enzymes in blood and aortic tissue were investigated in a cholesterol-induced atherosclerotic rabbit model. METHODS AND RESULTS: New Zealand white male rabbits were fed with regular chow (group I), chow supplemented with I% cholesterol (group II), regular chow plus amlodipine 5 mg/kg/day p.o. (group III) and I% cholesterol diet supplemented with amlodipine (group IV) for 8 weeks. Cholesterol, malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-Rd) were determined in blood samples drawn before and after the experimental period. Aortic tissue was examined morphologically for atherosclerotic changes and tissue cholesterol, MDA, GSSG, GSH-PX, GSH-Rd and glutathione-S-transferase (GST) were measured. After 8 weeks, blood cholesterol, MDA, GSSG and GSH-PX were elevated in groups II and IV; GSH was reduced in group IV; MDA levels were higher in group II than in group IV. Aortic tissue investigations revealed higher cholesterol and MDA concentrations in group II than in group IV. Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group II. Histopathological alterations related to atherogenesis were less in group IV than in group II. CONCLUSIONS: Amlodipine reduced the increase in oxidative stress by inhibiting excessive MDA production. Accelerated glutathione redox cycle activity of erythrocytes from animals supplemented with amlodipine suggests that this drug may reduce oxidative stress by enhancing the glutathione system. However, this drug does not seem to affect the glutathione redox cycle in the aortic tissue.     

Serum and urinary nitric oxide in Type 2 diabetes with or without microalbuminuria: relation to glomerular hyperfiltration

BACKGROUND: Glomerular hyperfiltration is considered as one of the pathophysiological mechanisms for the development of diabetic nephropathy. Oxidative stress is enhanced in patients with diabetes mellitus. Reportedly, nitric oxide (NO) might be involved in the pathogenesis of hyperfiltration. We investigated the relationship between hyperfiltration and NO system, and malondialdehyde (MDA) levels in Type 2 diabetics with/without microalbuminuria. METHODS: In 39 microalbuminuric, 29 normoalbuminuric Type 2 diabetic patients and 32 healthy controls, serum creatinine, nitrite, nitrate, urinary microalbumin, nitrite, nitrate, plasma MDA and estimated glomerular filtration rate (EGFR) values, calculated according to the Cockcroft and Gault formula, were recorded. RESULTS: Serum and urine NO levels were higher in both microalbuminurics and normoalbuminurics than controls. There were no significant differences in EGFR between groups. However, hyperfiltration was determined in 31% of normoalbuminurics and 20% of microalbuminurics. Serum and urine NO levels were higher in patients with hyperfiltration. Plasma MDA levels were significantly elevated in both microalbuminurics and normoalbuminurics when compared with controls. Serum glucose and microalbuminuria were positively correlated in microalbuminuric diabetics. Serum NO levels were also positively correlated with EGFR in both normoalbuminurics and microalbuminurics. HbA1c levels were positively correlated with both urinary albumin excretion and plasma MDA levels in normoalbuminuric diabetics. CONCLUSIONS: Hyperglycemia is associated with an increased NO biosynthesis and lipid peroxidation. Increased oxidative stress may contribute to the high NO levels in Type 2 diabetes. Furthermore, the high NO levels may lead to hyperfiltration and hyperperfusion, which in turn leads to an increase in urinary albumin excretion and thus causes progression of nephropathy in early Type 2 diabetes.