Oxidative stress in gastric mucosa of asymptomatic humans infected with Helicobacter pylori: effect of bacterial eradication.

BACKGROUND: Inducible nitric oxide synthase (iNOS) and interleukin 8 (IL-8) are positive in approximately 50% of Helicobacter pylori-related diseases but it is not clear whether oxidative stress is also present in H. pylori asymptomatic humans. Our aim was to study the expression of iNOS, superoxide dismutase, catalase and IL-8 production in H. pylori-infected asymptomatic humans, and to investigate the effect of eradication of H. pylori. MATERIALS AND METHODS: Biopsies of corpus and antrum of asymptomatic H. pylori positive and negative humans served for determination of the gastritis score and H. pylori status; iNOS was measured by reverse transcriptase polymerase chain reaction and immunohistochemistry and superoxide dismutase and catalase by immunohistochemistry. IL-8 in biopsies was assessed by enzyme-linked immunosorbent assay. RESULTS: Immunostaining of iNOS, catalase and superoxide dismutase was significantly associated with H. pylori infection and was localized to inflammatory cells. IL-8 concentrations were greater in the H. pylori positive than H. pylori negative group and decreased after bacterial eradication. A decrease in staining for iNOS and catalase was observed after H. pylori eradication. CONCLUSIONS: INOS and antioxidant enzymes are present in gastric biopsies of asymptomatic H. pylori positive humans. Eradication caused a significant decrease in staining for iNOS and catalase. These results indicate that oxidative stress occurs in asymptomatic patients and can be modulated by H. pylori eradication.

Resistance to insulin mediated glucose disposal in obese subjects: respective effect of lipid metabolism and glycemia.

The present study was designed to assess the respective effect of altered lipid metabolism and hyperglycemia on glucose metabolism in vivo in obese subjects. Six young obese non-diabetic volunteers were studied on four occasions during hyperinsulinemic clamp, twice during euglycemia and twice during hyperglycemia, with or without the infusion of beta-pyridylcarbinol, an inhibitor of lipid metabolism. Glucose oxidation was calculated from continuous respiratory exchange measurements, and glucose storage was obtained as the difference between total glucose disposal and glucose oxidation. Two-way analysis of variance (with interaction term) demonstrated (i) a significant increase for total glucose disposal with beta-pyridylcarbinol but no significant effect of hyperglycemia and no interaction between the two treatments, and (ii) an important increase of beta-pyridylcarbinol to enhance glucose storage but no significant effect of hyperglycemia and no interaction between the two treatments. These results show that obese people, at physiological insulinemia, enhance their glucose disposal and glucose storage when lipid oxidation is artificially lowered. This suggests that enhanced lipid oxidation is related to insulin resistance in these patients. However, hyperglycemia in these patients failed to compensate for defective glucose disposal or storage.

Autosomal dominant ichthyosis and X-linked ichthyosis. Comparison of their clinical and histological phenotypes.

The clinical and histologic distinction between X-linked recessive and autosomal dominant ichthyosis was studied by evaluating 12 classical differential parameters in 85 patients. Thirty-three of them had X-linked and 52 autosomal dominant ichthyosis. Eight of these parameters were generally helpful in the differential diagnosis: age of onset, severity of involvement, scale size, chapping of hands and feet, atopic background, influence of warm weather, corneal opacities and state of the granular layer. Involvement of skin folds, keratosis pilaris, increased palmo-plantar markings and improvement with age were unreliable. In the literature, age of onset and corneal opacities were additionally found unreliable; the histology was of limited value in two reports. Therefore, we concluded that the herein evaluated differential criteria seem to be valid mainly when considering groups of patients. For the individual case, an error in diagnosis, particularly in X-linked ichthyosis, is not rare when relying solely on these criteria. When in doubt, determination of steroid sulphatase activity is mandatory.

Double-blind study in the treatment of normal tension glaucoma with naftidrofuryl.

Naftidrofuryl is an antiserotonin S2-specific agent, with the three following effects: (1) peripheral vasodilatation, (2) antiaggregation and (3) increase in cellular metabolic. These effects could be interesting in the management of the optic nerve ischemia of glaucomatous patients and especially of those with normal tension glaucoma. The administration of 2 x 200 mg/day of naftidrofuryl during 6 weeks to 12 patients with normal tension glaucoma has shown an improvement of the visual acuity and the visual field compared with a 6-week period of placebo administration, with a double-blind study method. It suggested that naftidrofuryl might be administered as a useful complement to conventional hypotensive therapy, since it acts positively on the glaucomatous optic nerve damage.

Impairment of glucose disposal by infusion of triglycerides in humans: role of glycemia.

The present study was designed to assess the role of hyperglycemia (150 mg/dl) vs. euglycemia (90 mg/dl) on glucose metabolism in vivo during the infusion of a triglyceride emulsion (Intralipid). Seven young healthy volunteers were studied on four occasions using the hyperinsulinemic clamp technique, twice during euglycemia and twice during hyperglycemia, without or with Intralipid. Glucose oxidation (O) was calculated from continuous respiratory exchange measurements, and glucose storage (S) was obtained as the difference between total glucose disposal (M) and O. Two-way analysis of variance with interaction term demonstrated 1) a significant increase for M with hyperglycemia and a decrease with Intralipid; no interaction, and 2) in euglycemia, O/M and S/M occurred in one-to-one ratios; on the other hand, during 150-mg/dl hyperglycemia, the ratio dropped roughly to 1:2. Intralipid had no effect on the ratio, and no interaction could be observed. These results suggest the existence of physiological regulatory mechanisms by which 1) the rise in plasma free fatty acid inhibits both oxidative and nonoxidative glucose disposal, and 2) the rise in glycemia stimulates predominantly nonoxidative glucose disposal.

The implications of the heterogeneous distribution of Ki-67 labelled cells in meningiomas.

Ki-67 monoclonal antibody reacts with a nuclear protein only expressed in proliferating cells. In order to evaluate the applicability of Ki-67 in meningiomas we determined the index of labelled cells in 52 biopsies. Two counting methods were used to calculate the labelling index. The mean Ki-67 index was determined by the number of positive Ki-67 cells in three randomly chosen fields divided by the total number of cells in the three fields. The preparations were also screened for the area with the highest percentage of positive Ki-67 cells, yielding the 'highest' Ki-index. The three patients who developed a recurrence did not show an elevated Ki-67 index by any of the two counting methods. Because of the differences observed between the two counting methods and the differences of the Ki-67 indices in the three randomly chosen fields we performed a statistical analysis to evaluate the possibility of a heterogeneous distribution of Ki-67 positive cells in meningiomas. Homogeneity was rejected if the data showed no Poisson distribution. We found that five of the 13 tumours which had a mean Ki-67 index greater than 1.00% were heterogeneous (38.4%). One of the highest differences between the two counting methods (5.05%) was noted in the only tumour with local signs of malignancy. Our results indicate a heterogeneity of the labelling of Ki-67 in histologically benign meningiomas and emphasise the importance of representative sampling. More attention should be paid to this heterogeneity for cell kinetic studies in brain tumours, and one should be aware that regrowth is not only determined by the proliferative capacity.

A study of beta-cell function after glucagon stimulation in thalassaemia major treated by high transfusion programme.

An increased incidence of diabetes mellitus and glucose intolerance has been reported in thalassaemia major treated with a high transfusion programme (HTP). To investigate beta-cell function, serum immunoreactive insulin (IRI), C-peptide (CP) and glucose were measured fasting and at 3, 6 and 10 min after i.v. administration of 1 mg glucagon in 20 thalassaemia patients treated by many transfusions and in nine healthy control subjects. Fasting C-peptide concentrations (mean +/- SEM) were higher in the thalassaemic group (2.15 +/- 0.17 ng/ml) than in the controls (1.41 +/- 0.13 ng/ml). After stimulation with glucagon, C-peptide concentrations were consistently higher (P less than 0.01) by approximately 50% in the thalassaemic than in the control group (5.29 +/- 0.31 vs 3.36 +/- 0.21 ng/ml, at 3 min; 5.22 +/- 0.30 vs 3.53 +/- 0.21 ng/ml at 6 min and 4.69 +/- 0.27 vs 3.30 +/- 0.17 ng/ml after 10 min). Plasma IRI concentrations increased in both groups after glucagon stimulation but were not significantly different. The glucose values were approximately 15% higher at each sampling time in the thalassaemic group than those of the normal subjects. It is concluded that disturbances in carbohydrate metabolism in thalassaemia major treated with HTP are the consequence of hepatic cirrhosis which accompanies secondary haemosiderosis, and possibly iron deposition in the beta-cells of the pancreas.