Biomedical subjects

M Henein

Publications and source records attributed to M Henein.

24 records · Page 2Linked to original sources

PubMed1999

Attenuation of galactose-induced cataract by pyruvate.

Data in the present paper demonstrate a significant inhibition in the progress of sugar cataract formation by systemic administration of pyruvate. The formation of the cataract was induced by feeding young rats a diet containing 30% galactose. All animals fed this diet developed nuclear lens opacity by the end of 30 days. This was delayed if the diet and water contained, in addition, 2% sodium pyruvate. The incidence of cataract in the latter group was 0% at day 30 and only 25% at day 55. Physiologically, the inhibition was associated with the prevention of lens membrane damage as reflected by its ability to maintain transport of rubidium ions against a concentration gradient; decreased tissue hydration as indexed by the lens wet weight; inhibition of protein glycation, and higher levels of ATP. Since pyruvate, being a normal tissue metabolite, is likely to be non-toxic, the findings are considered useful for further pharmacological studies with this and other similar metabolites, relevant to protection against various secondary complications of diabetes and galactosemia.

Adenosine Triphosphate↗

PubMed1998

Corneal damage by half mustard (2-chloroethyl ethyl sulfide, CEES) in vitro preventive studies: a histologic and electron microscopic evaluation.

The effect of half-mustard (2-chloroethyl ethyl sulfide, CEES) on the morphology and ultrastructure of the cornea has been studied in vitro. Extensive necrotic changes were observed histologically as well as electron microscopically. The outer layer of corneal epithelium was observed to undergo vacuolization and globulization prior to its denudation. The epithelium becomes separated from the Bowman's membrane. These necrotic changes are prevented from taking place in the presence of a mixture of taurine, pyruvic acid, alpha-keto glutaric acid and pantothenic acid suggesting the use of this mixture in the prevention of mustard damage.

Animals↗

PubMed1997

Nonsurgical septal reduction for hypertrophic obstructive cardiomyopathy: outcome in the first series of patients.

BACKGROUND: Some patients with hypertrophic obstructive cardiomyopathy may gain symptomatic relief from a reduction in the extent of obstruction to left ventricular outflow. We present the outcome of the first series of patients treated with an alternative method of gradient reduction using catheter techniques. METHODS AND RESULTS: Eighteen patients were treated with selective intracoronary alcohol injection to induce localized septal infarction. Patients underwent echocardiographic measurement of left ventricular dimensions and Doppler echocardiographic evaluation of left ventricular outflow tract gradients before the procedure, on the first postoperative day, and at a median follow-up of 3 months after the procedure. In addition, patients underwent exercise testing and symptom evaluation before and 3 months after nonsurgical septal reduction. There was a significant reduction in left ventricular outflow tract obstruction after the procedure (preprocedure, 67 mm Hg [95% CI, 48 to 87 mm Hg]; postprocedure, 25 mm Hg [95% CI, 16 to 34 mm Hg]; P=.0006), which persisted at 3-month follow-up (22 mm Hg [95% CI, 12 to 32 mm Hg]; P=.001). This was associated with a significant improvement in symptoms. There was a small but not significant increase in exercise capacity (n=10; preprocedure, 418 seconds [95% CI, 273 to 563 seconds]; postprocedure, 452 seconds [95% CI, 283 to 621 seconds). Left ventricular dimensions were not significantly altered by nonsurgical septal reduction. CONCLUSIONS: Nonsurgical septal reduction significantly reduces left ventricular outflow tract obstruction and improves symptoms in some patients with hypertrophic obstructive cardiomyopathy. The technique may provide an alternative to surgical myomectomy in selected patients.

Adolescent↗

PubMed1992

Prevention of galactose cataract by pyruvate.

The effect of pyruvate on the progress of galactose cataract has been studied. Pyruvate was administered topically in the form of eye drops. Such treatment was found to delay the onset of the cataractous changes. Cataract formation was studied by visual inspection with pen light, as well as with slit lamp biomicroscopy in the intact animal. The delay in the formation of cataract was associated with the preservation of the levels of lens ATP, soluble proteins and the decreased accumulation of galactitol. In vitro organ culture experiments yielded similar results.

Adenosine Triphosphate↗

PubMed1991

Prevention of selenite cataract by vitamin C.

Studies have been conducted to determine the efficacy of vitamin C in the prevention of cataracts induced by selenite. Administration of the latter to rat pups results in the development of advanced cataracts within 5 days. Treatment with ascorbate had a significant preventive effect. The observations indicate that selenite cataract is due to an oxidative stress to the lens. In addition, the findings are in conformity with our view that ascorbate functions as an anticataractogenic substance.

3,4-Methylenedioxyamphetamine↗

PubMed1991

Radio-isotopic determination of hydrogen peroxide in aqueous humor and urine.

The concentrations of hydrogen peroxide in the aqueous humor and urine of several animal species and humans have been determined. The determinations are based on peroxide-dependent decarboxylation of I-[14C]-alpha-ketoglutaric acid and measurement of the resulting 14CO2 by quantitating the radioactive disintegration. The levels of H2O2 in most animals varied between 5.0 and 41 microM for aqueous, and 115 and 187 microM for urine. The levels of peroxide in the urine of steer, cat and baboon were lower and fell out of the above range. In the aqueous of humans with cataracts, the levels ranged from 33 to 324 microM, the overall average being 189 +/- 88 microM. The source of such high levels in the aqueous of cataract patients is currently being studied.

Aged↗