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Biomedical subjects

N Amin

Publications and source records attributed to N Amin.

12 recordsLinked to original sources
PubMed1992

Requirement for GLY-60 of Escherichia coli adenylyl cyclase for ATP binding and catalytic activity.

The region of Escherichia coli adenylyl cyclase spanned by glycine-55 to threonine-65 was tested for its importance for enzyme activity. Site-directed mutagenesis was used to replace glycine-55 and glycine-60 as well as lysine-59, leucine-63 and threonine-65 with other amino acids. While substitution of glycine-55 with aspartic acid produced no significant change in kinetic parameters, the change of glycine-60 to aspartic acid or asparagine eliminated binding to 8-azido-ATP and decreased the Vmax (two orders of magnitude) and Km (factor of four-five). Smaller effects on kinetic parameters were observed with substitutions of lysine-59, leucine-63 or threonine-65.

Adenosine Triphosphate↗
PubMed1981

Detection of lysozyme production using modified technique as an aid for the identification of pathogenic staphylococci causing some animal and human diseases.

Lysozyme production is an essential character of the potentially pathogenic staphylococci. In the present work 88 strains of animal origin and 40 strains of human origin were tested. Of 103 strains isolated from pathogenic cases of human and animal origin 89 (86.4%) were lysozyme producers and 86 (83.5%) were coagulase positive. Out of 75 strains isolated from pathogenic cases of animal origin 75 (100%) were lysozyme producers and 71 (94.6%) were coagulase positive. On the other hand out of 28 strains isolated from pathogenic human cases 14 (50%) were lysozyme producers and 15 (53.6%) were coagulase positive. This indicates that lysozyme production could be a better index of pathogenic staphylococci than the coagulase measurement specially in cases of animal origin strains. The method used in this work for the determination of the lysozyme production seems to be a simple one if compared with other used methods.

Animals↗
PubMed1979

Giardiasis: a common cause of diarrheal disease.

Giardiasis has been reported increasingly among visitors to the Soviet Union and is found at epidemic and endemic levels in the United States. The main source of infection is contaminated water. Children, homosexual males, and patients with gastrectomy, achlorhydria, hypogammaglobulinemia, secretory IgA deficiency, or alteration in immune status are particularly susceptible to severe, often chronic, infection. Symptomatic giardiasis can be acute, subacute, or chronic. Symptoms are explosive, watery, foul-smelling stools or semisolid stools with evidence of steatorrhea; flatulence; abdominal distention; and weight loss. Diagnosis usually can be established by examination of stool or duodenal fluid for cysts or trophozoites. Quinacrine hydrochloride is the drug preferred for treatment, but metronidazole and furazolidone are also useful.

Diarrhea↗
PubMed1977

The fate of intravenously infused gelatin.

The fate of i.v. infused gelatin was studied by measuring the rise in the level of total hydroxyproline (HP) in some organs of the rat following the infusion of a 5% autoclaved gelatin solution (1 ml/100 g body weight). The results obtained showed that HP levels were consequently increased in all of the organs studied, then the levels were generally normalised during the 3rd day post infusion. Small concentrations of HP were still retained by the kidneys and blood plasma, at the end of the first week after infusion. The rat ratio HP/creatinine (HP/C index), which increased from 0.33 to 3.78 during the first 24 h post infusion, declined gradually to the base-line level after 4 weeks, during which time 94% of the HP infused could be accounted for in the urine. Most of the HP was excreted in the bound form.

Animals↗
PubMed1975

Bood glucose level in pregnancy.

Oral glucose tolerance curves were constructed for 50 normal pregnant women, 25 pre-diabetics and 25 cases of diabetic pregnant women of different degrees of disturbance in carbohydrate metabolism. The mean rise in blood glucose level after the intake of 50 g glucose, was 53% in normal cases, and only 41% in the prediabetic cases, due to increased insulin secretion in the prediabetic group. This group of pregnants gave flat-topped curves in 60% of the cases studied, as compared to 10% of the normal pregnant cases in the same study. This was attributed to delayed insulin secretion in the prediabetic group. On the other hand, all diabetic cases gave peaked glucose tolerance curves during the first hour after glucose intake. The results of insulin-glucose tolerance test, effect of fasting for four hours and tolbutamide sensitivity test suggested that the prediabetic pregnants showed hyperinsulinemia which became evident during fasting. The pancreas of the prediabetic responds more readily, by the release of insulin, to the stimulus of oral hypoglycemic agents, such as sodium tolbutamide, than in the case of normal pregnants. Measurements of serum inorganic phosphorus, serum potassium and serum alkaline phosphatase of these 3 groups of pregnants, showed a definite disturbance in the liver function of the prediabetics which became more obvious in the diabetic group.

Alkaline Phosphatase↗