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Biomedical subjects

V M Doctor

Publications and source records attributed to V M Doctor.

At least 55 records · Page 3Linked to original sources
PubMed1971

Florid papillomatosis (adenoma) and other benign tumours of the nipple and areola.

The paper deals with 20 benign tumours of the nipple and areola. The most common lesion was adenoma or florid papillomatosis (11 cases). On the basis of clinical and histological differences, the cases were divided into two groups.Group I.-Tumours showing an adenomatous pattern (5 cases) appropriately termed adenoma of the nipple. Chief clinical features were younger age, long duration and enlargement of the nipple as a predominant symptom. Histological characteristics were elongated tubules separated by a varying amount of fibrous stroma and squamous metaplasia in some of the cases.Group II.-Tumours showing a papillomatous pattern (6 cases) appropriately designated as florid papillomatosis. Clinically, the patients were older. Chief complaint was bleeding from the nipple of a few months' duration. Histologically, dilated lactiferous ducts were seen filled with papillary, cribriform and solid growth of cells. Other features such as apocrine metaplasia, foam cells and central necrosis were observed.The interpretation of this grouping is discussed.A case of adenoma of an accessory nipple is reported.Other benign tumours observed were five papillomas, one leiomyoma, one haemangioma, one fibroma and one lipoma.

Adenoma↗
PubMed1969

Mechanism of non-enzymic transamination reaction between histidine and alpha-oxoglutaric acid.

Non-enzymic transamination reactions at 85 degrees between various amino acids and alpha-oxoglutaric acid are catalysed by metal ions, e.g. Al(3+), Fe(2+), Cu(2+) and Fe(3+). The reaction is optimum at pH4.0. Of the 14 amino acids studied histidine is the most active. In the presence of Al(3+) histidine transaminates with alpha-oxoglutaric acid, forming glutamic acid and Al(3+)-imidazolylpyruvic acid complex as the end products. However, in the presence of Fe(2+) or Cu(2+) the products are glutamic acid and a 1:2 metal ion-imidazolylpyruvic acid chelate. The greater effectiveness of histidine in these reactions is attributed to the presence of the tertiary imidazole nitrogen atom, which is involved in the formation of stable sparingly soluble metal ion-imidazolylpyruvic acid complexes or chelates as end products of these reactions. Of the metal ions studied only Al(3+), Fe(2+), Fe(3+) and Cu(2+) are effective catalysts for the transamination reactions, and EDTA addition completely inhibits the catalytic effect of the Al(3+). Spectrophotometric evidence is presented to demonstrate the presence of metal ion complexes of Schiff bases of histidine as intermediates in the transamination reactions. These results may contribute to understanding the role of histidine in enzyme catalysis.

Aluminum↗
PubMed1968

Penicillium mycelium waste as protein supplement in animals.

Dried Penicillium mycelium served as a protein source in animal diet when it was supplemented at 7.5% protein level along with 7.5% protein level from peanut meal. Under these conditions, the food consumption was optimal, and the rat growth response was comparable with 15% casein diet. The role of peanut meal appears to be twofold; it makes the mycelium diet more palatable and it supplies protein. The amino acids, lysine and threonine, which are found to be limiting in peanut meal, are reported to be present in the Penicillium mycelium. This type of formulation affords considerable economic advantage because both the peanut meal and the Penicillium mycelium are by-products and, therefore, are inexpensive sources of protein.

Journal Article↗
PubMed1967

Countercurrent distribution studies on hamycin.

Hamycin, a polyene antifungal antibiotic, was isolated by use of countercurrent distribution. A pattern was obtained by plotting the absorption at 383 mmu of the contents of the various tubes against the tube numbers. The results indicated that the antibiotic contained three fractions, a major fraction (peak 2) comprising 48% of the total activity and two minor fractions (peak 1 and peak 3) comprising 3.62 and 11.32%, respectively, of the total activity. The solid material was isolated by pooling the contents of the tubes containing the major fraction, concentrating this in vacuo, and cooling. The antibiotic activities of the three peaks were evaluated by use of a cup-plate assay method with Paecilomyces varioti as test organism. All three components showed antibiotic activity; however, the preparation obtained from the major fraction showed approximately a 7-fold increase in antibiotic activity, a doubling of the E(1cm) (1%) value at 383 mmu, and approximately a 2.5-fold decrease in the amino acid content in comparison with the starting material. There was an apparent correlation obtained by plotting the curves of the absorption at 383 mmu of the different tubes comprising the major fraction and their biological activities.

Antifungal Agents↗
PubMed1965

Production of calcium gluconate by Penicillium chrysogenum in submerged culture.

The waste mycelium of Penicillium chrysogenum HA-10 (obtained at the end of penicillin fermentation), or a 24-hr-old freshly grown vegetative inoculum of this organism, was found to utilize glucose for the production of calcium gluconate by submerged fermentation in shake flasks. After 72 to 96 hr of fermentation at 24 C, 90 to 95% of the reducing sugar from the 15% glucose medium was converted to calcium gluconate. Reuse of the mycelium for successive experiments reduced the fermentation period to 72 hr or less because of an enhancement of glucose utilization. Ten successive batches of 15% glucose medium were fermented by the reuse method. Fermentation media containing up to 30% glucose could be used, provided boric acid was added to prevent the precipitation of calcium gluconate formed. We found that 30% hydrol (a by-product of glucose manufacture containing 50 to 55% reducing sugar), when used in place of glucose in the fermentation medium, inhibited the rate of glucose utilization. However, this effect was partially reversed by pretreatment of hydrol with 2 to 4% activated charcoal before addition to the fermentation medium.

Bacteriological Techniques↗