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Biomedical subjects

A Oner

Publications and source records attributed to A Oner.

At least 37 records · Page 2Linked to original sources
PubMed1995

The effect of the treatment of high-dose methylprednisolone on Na(+)-K(+)/Mg(+2) ATPase activity and lipid peroxidation and ultrastructural findings following cerebral contusion in rat.

BACKGROUND: Although use of corticosteroid in the management of head trauma has caused a great deal of controversy, corticosteroids have long been an adjunct in the management of severe closed head injury. The glucocorticoid steroid methylprednisolone (MP) has been proven to have significant antioxidant effect when administered in an antioxidant-high dose after central nervous system injury. METHODS: The sodium-potassium activated and magnesium dependent adenosine-5'-triphosphatase (Na(+)-K(+)/Mg(+2) ATPase EC.3.6.1.3.) activity, lipid peroxidation, and early ultrastructural findings were determined during the immediate posttraumatic period in rats. Mechanical brain injury was produced when a calibrated weight-drop device is allowed to fall on the skull's convexity over the right hemisphere, 1 to 2 mm lateral from the midline. In group I, rats were used to determine Na(+)-K(+)/Mg(+2) ATPase activity, the extent of lipid peroxidation, by measuring the level of malondialdehyde content and normal ultrastructural findings in two different brain areas (cerebral cortex and brain stem). In group II, physiologic saline was administered right after trauma in the same amount as methylprednisolone. In group III rats, methylprednisolone (30 mg/kg) was administered intravenously right after trauma. RESULTS: Na(+)-K(+)/Mg(+2) ATPase activity significantly decreased in the cerebral cortex and in brain stem within 2 hours after trauma (p < 0.05). There was significant difference in malondialdehyde content between groups II and III (p < 0.05). Methylprednisolone treatment reduced malondialdehyde content and induced the recovery of Na(+)-K(+)/Mg(+2) activity. CONCLUSIONS: These data suggest that inactivation of Na(+)-K(+)/Mg(+2) ATPase is closely correlated to changes of lipid peroxidation and the alteration of the ultrastructural findings in the early phases after head trauma. The glucocorticoid steroid methylprednisolone has been proven to have significant effect in activation of Na(+)-K(+)/Mg(+2) ATPase with significant reduction of malondialdehyde content.

Animals↗
PubMed1995

Effects of naloxone on sodium- and potassium-activated and magnesium-dependent adenosine-5'-triphosphatase activity and lipid peroxidation and early ultrastructural findings after experimental spinal cord injury.

Endorphins have been implicated in the pathophysiology of spinal cord injury. The effect of naloxone on the sodium- and potassium-activated and magnesium-dependent adenosine-5'-triphosphatase (Na(+)-K+/Mg+2 ATPase, EC.3.6.1.3.) activity, lipid peroxidation, and early ultrastructural findings were studied in rats at the early stage of spinal cord injury, produced with an aneurysm clip on the T2-T7 segments. The rats were divided into four groups. The 10 rats in Group I, which had no injury and received no medication, were used for determining Na(+)-K+/Mg+2 ATPase activity, the extent of lipid peroxidation (by measuring the level of thiobarbituric acid-reactive substances as malondialdehyde), and normal ultrastructural findings. On the 15 rats in Group II, without spinal cord injury, only laminectomy was performed to determine the effect of surgery on the biochemical indices and findings. In the 15 rats in Group III, physiological saline was administered intraperitoneally in an amount equivalent to that of the naloxone administered immediately after spinal cord injury. In the 15 rats in Group IV, 0.5 mg of naloxone was administered intraperitoneally as a single dose immediately after injury and again 60 minutes after injury. The Na(+)-K+/Mg+2 ATPase activity was promptly reduced after spinal cord injury and remained in a lower level than the levels of Groups I and II during 120 minutes after injury. Naloxone treatment, immediately after trauma, attenuated the inactivation of Na(+)-K+/Mg+2 ATPase. On the other hand, there was a significant difference in the malondialdehyde content between animals in Groups I and III. Naloxone treatment reduced the malondialdehyde content in Group IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Efficacy of a one-step hydrogen peroxide system for disinfection of soft contact lenses.

We investigated the efficacy of a one-step hydrogen peroxide system by culturing soft contact lenses before and after exposure to the AOSEPT disinfection system. Sixteen of 38 soft contact lenses obtained from asymptomatic wearers showed microbial growth. Nine cultures were positive for Pseudomonas sp., four showed growth of Staphylococcus sp., two were positive for beta-hemolytic streptococci, and one culture was positive for Alcaligenes faecalis. A second culture of the contact lenses after hydrogen peroxide disinfection showed no growth in 12 of the 16 previous positive cultures. The rate of disinfection was 55% for Pseudomonas sp. and 100% for other bacteria.

Adolescent↗
PubMed1993

Fluid retention and cardiomegaly associated with carbamazepine in an epileptic child.

Carbamazepine (CBZ) has been reported to have an antidiuretic action, though it is not known how it produces this effect. This is a well recognized complication of CBZ therapy in adults. However this syndrome has been rarely observed in childhood. We present an epileptic child with fluid overload due to CBZ treatment who was referred with chest pain and cardiomegaly. Our patient developed fluid retention with cardiomegaly during treatment with CBZ alone at a normal dose and for a short time. To our knowledge this is the first case of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) due to CBZ therapy which has been observed to be associated with cardiomegaly.

Adolescent↗
PubMed1992

Cranial nerve involvement in childhood polyarteritis nodosa.

Amongst a variety of neurological manifestations of childhood polyarteritis nodosa, cranial nerve involvement is unusual. We report 4 cases with cranial nerve palsies in a series of 36 biopsy-proven patients. Two cases presented with IIIrd nerve palsy alone, one with right IIIrd and left IVth nerve palsy, and one with peripheral VIIth nerve paresis. All 4 patients showed good response to prednisolone and cyclophosphamide treatment. Cranial nerve involvement in childhood polyarteritis nodosa seems not so rare when patients are followed on long term basis.

Biopsy↗
PubMed1991

Identification of the source of haematuria by automated measurement of mean corpuscular volume of urinary red cells.

The appearance of red blood cells in the urine may be the result of disease of any segment of the urinary tract. To determine whether there might be a distinguishing characteristic of the urinary red cells which appear during glomerular disease but is absent in other urinary tract diseases, the mean corpuscular volumes (MCV) of urinary and blood erythrocytes were measured by a Coulter counter in 34 children with haematuria. Diagnosis of the underlying renal or urinary tract disease was made by clinical and laboratory findings, including radiological investigations, renal biopsy and cystoscopy. The ratio of the urinary erythrocyte MCV to that in blood (Umcv/Bmcv) was compared with the diagnosis. The Umcv/Bmcv ratio was less than 1.0 in all children with glomerular disease and was greater than 1.0 in all but 1 of the patients with non-glomerular disease. This study suggests that the Umcv/Bmcv ratio provides a simple and useful technique for distinguishing between glomerular and non-glomerular haematuria. Such determination would help in guiding appropriate diagnostic evaluation.

Adolescent↗
PubMed1989

Safety and efficacy of calcium carbonate in children with chronic renal failure.

The safety and clinical efficacy of calcium carbonate therapy in children with chronic renal failure were assessed in 68 patients (average age 8.38 years) during a mean follow-up period of 19.9 months (range 1.2-49.4). Forty-seven episodes of hypercalcaemia occurred in 29 children (3.5 episodes per 100 patient-months). There were no significant differences in mean GFR or biochemical parameters between these patients at the start of calcium carbonate therapy and the group of children who never experienced hypercalcaemia. Good control of secondary hyperparathyroidism and a significant reduction in serum aluminum were achieved. Two of 23 hypercalcaemic patients showed nephrocalcinosis on ultrasonography. 99Tc pyrophosphate scanning failed to detect any other ectopic calcification. The incidence of hypercalcaemia increased significantly when the GFR was less than 15 ml/min per 1.73 m2 and was most frequent in children receiving dialysis (48 episodes per 100 patient-months). The decrease in GFR during therapy was significantly more in the hypercalcaemic group compared to the normocalcaemic group (P less than 0.01), despite no irreversible acute effects of hypercalcaemia being observed on the rate of decline of GFR. We believe that the reduced renal homeostatic reserve is a major factor predisposing to hypercalcaemia. Consequently calcium carbonate is safe to use in children with severe chronic renal failure with close biochemical monitoring; the benefits over aluminium phosphate binders far outweigh the risks of hypercalcaemia and ectopic calcification.

Adolescent↗
PubMed1988

Correction of vesicoureteral reflux by the Gil-Vernet procedure.

Gil-Vernet antireflux procedure has been carried out for 22 refluxing renal units (14 patients), yielding a positive outcome in all, with disappearance of refluxing in 94% of the renal units with grade II, III and IV vesicoureteral reflux. The efficiency and simplicity of the technique is emphasized.

Humans↗
PubMed1987

Xanthogranulomatous pyelonephritis in children and adults.

Sixteen patients with xanthogranulomatous pyelonephritis (XGP) are reported. The preoperative diagnosis of XGP may be difficult because of its clinical and radiological similarities to various other renal lesions, but in four patients XGP was suspected pre-operatively. Nephrectomy is necessary in most patients, although medical treatment may help a few.

Adolescent↗