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Biomedical subjects

A K Mathur

Publications and source records attributed to A K Mathur.

At least 37 records · Page 2Linked to original sources

Dermal exposure to detergents.

Epidermal erosion and a 40-60% increase in histamine content of skin were observed in guinea pigs treated with different concentrations of detergents. The primary irritation indices of these animals ranged between 0.3 and 1.5. Eight human subjects with skin lesions attributable to detergent exposure were patch tested with 500 mg of detergents. A positive reaction was observed in 7 of 8 cases. In 4 cases reaction was observed within 24-48 h, while 3 cases had a severe reaction after 72 h. IgA and IgM levels were raised in 2 subjects. This study highlights the irritancy potential and toxic effects of detergent products available in Indian markets.

Animals↗

Dermal toxicity of paraphenylenediamine.

The guinea pigs were dermally exposed to paraphenylenediamine (PPD) and in presence of an oxidising agent hydrogen peroxide for 15 and 30 d to assess their effects on some enzymes, lipid peroxidation and histamine contents in the skin. The activities of acid and alkaline phosphatases, beta-glucuronidase, gamma glutamyl transpeptidase, histidase and tyrosinase were enhanced after application of either PPD or PPD plus hydrogen peroxide. The lipid peroxidation and histamine contents also showed marked elevation following exposure to the chemicals.

Acid Phosphatase↗

Dermal exposure of hexachlorophene to guinea pigs.

The skins of guinea pigs were exposed to 50 mg/kg hexachlorophene (HCP) for 7, 15 or 30 days. The activities of skin marker enzymes (beta-glucuronidase, histidase, tyrosinase) increased, but glutathione decreased. Lipid peroxidation and histamine contents increased during different time intervals. The histopathological changes showed damage to epidermis and dermis. Depending on the duration of exposure, HCP produces biochemical and histopathological damage to skin.

Animals↗

The clinical and biochemical study of pesticide sprayers.

Clinical, haematological and biochemical studies of 34 subjects, occupationally exposed to different types of pesticides, were conducted. The findings have been compared with those observed in 14 control subjects. Inhibition of cholinesterase activity was observed in the exposed group. Serum alkaline phosphatase was also found to be raised. Radiological examination revealed pneumonitic patches in the chest skiagrams of three exposed subjects. Paraesthesia with hyporeflexia was also found in 8.8% of exposed subjects. The findings suggest that exposure to multiple pesticides over many years affects the normal functioning of different organ systems and may produce characteristic clinical effects.

Acetylcholinesterase↗

Biochemical and histopathological changes following dermal exposure to paraphenylene diamine in guinea pigs.

The guinea pigs were dermally exposed to paraphenylene diamine (PPD) at a dose level of 0.1 ml day-1 of a 1.0% (w/v) solution of PPD for 1, 3, 5 and 7 days. The absorption of PPD and its effects on lipid peroxidation, glutathione, histamine and several enzymes were assessed in skin and serum. Histopathological changes in liver, kidney and skin were examined also. The findings of the study indicated that PPD exposure resulted in significantly increased levels of lipid peroxidation and histamine contents in skin. The activity of enzymes increased significantly in skin and serum. PPD exposure also showed degenerative changes in liver and hyperkeratosis together with infiltration of cells in the dermis. Biochemical defects and histopathological changes in skin and serum correlated with the duration of exposure.

Administration, Topical↗

Human equivalent doses of platelet inhibitors and experimental atherosclerosis.

The effects of aspirin, dipyridamole and sulfinpyrazone on the development of atherosclerotic lesions in the aorta were studied in cholesterol-fed rabbits. Aspirin and sulfinpyrazone prevented the development of atherosclerosis, whereas dipyridamole-treated animals developed advanced atherosclerotic lesions. As all the three drugs inhibit platelet function, some non-platelet effects are probably responsible for the differences in results. It is felt that dipyridamole should be avoided in hypercholesterolemic individuals.

Animals↗

Synthetic detergents induced-biochemical and histological changes in skin of guinea pigs.

The linear alkylbenzene sulphonate (LAS) based synthetic detergents-induced decrease in lipid peroxydation and increase in histamine content in exposed skin of guinea pigs in a dose-dependent manner. Histopathological alterations of exposed skin included moderate degree of hyperkeratinization at lower concentration but necrosis, scarring, sloughing as well as discontinuity of epidermis at higher concentrations. The results shows that the contact of skin with detergents causes dermal toxicity.

Alkanesulfonates↗

Renal effects of calcium channel blockers in vivo.

Daily output of urine was measured in three groups of five rabbits each, before and during seven days of oral therapy with nifedipine, verapamil and diltiazem. All the drugs caused significant (P less than 0.001) increases in mean daily output. All the drugs decreased levels of serum sodium but serum potassium levels were lowered only by diltiazem. Inhibition of tubular transport appears to be the important mechanism.

Animals↗

Effect of esophageal erosion on esophageal electrocardiogram.

We recorded an esophageal electrocardiogram in a rabbit before and after producing esophageal erosion. The erosion caused an increase in P wave and R wave height and inversion of the T wave. Esophageal erosion can thus cause false positive repolarization changes in the esophageal electrocardiogram.

Animals↗

Effect of sodium lauryl sulphate and nickel alone and in combination on the skin of guinea pigs.

Guinea pig skin was treated with 50 mg/kg sodium lauryl sulphate (SLS) and nickel (Ni) alone and in combination (50 mg/kg SLS and 50 mg/kg Ni) for 7 and 14 days. Release of acid phosphatase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, beta-glucuronidase, lactic dehydrogenase and malic dehydrogenase was observed, following treatment with SLS and Ni alone or in combination. Similarly, the skin contents of amino nitrogen and sulphydryl groups also increased significantly. These alterations were slightly more marked when the skin was treated simultaneously with the combination of SLS and Ni. The present study suggests that industrial workers or populations exposed simultaneously to SLS and Ni are more prone to dermal irritation or inflammation.

Acid Phosphatase↗