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Biomedical subjects

V Nagarajan

Publications and source records attributed to V Nagarajan.

At least 55 records · Page 3Linked to original sources
PubMed1990

Isolation and characterization of levansucrase-encoding gene from Bacillus amyloliquefaciens.

The gene encoding levansucrase (LVS) from Bacillus amyloliquefaciens (sacB[BamP]) was isolated, sequenced and expressed in Bacillus subtilis. Analysis of the nucleotide sequence of sacB[BamP] reveals extensive homology with that of the B. subtilis LVS-encoding gene in the promoter and coding region. The sacB[BamP] gene cloned in a multicopy plasmid is induced by sucrose in B. subtilis.

Amino Acid Sequence↗
PubMed1990

Effect of specific mutations of tyrosine-(M)210 on the primary photosynthetic electron-transfer process in Rhodobacter sphaeroides.

We have measured the rate of the initial electron-transfer process as a function of temperature in reaction centers in a native strain of the photosynthetic bacterium Rhodobacter sphaeroides and two mutants generated by site-directed mutagenesis. In the mutants, a tyrosine residue in the vicinity of the primary electron donor and acceptor molecules was replaced by either phenylalanine or isoleucine. The electron-transfer reaction is slower in the mutants and has a qualitatively different dependence on temperature. In native reaction centers the rate increases as the temperature is reduced, in the phenylalanine mutant it is virtually independent of temperature, and in the isoleucine mutant it decreases with decreasing temperature. At 77 K, the electron-transfer reaction is approximately 30 times slower in the isoleucine mutant than in the native. These observations support the view that tyrosine-(M)210 plays an important role in the electron-transfer mechanism. In the isoleucine mutant at low temperatures, the stimulated emission from the excited reaction center undergoes a time-dependent shift to shorter wavelengths.

Electron Transport↗
PubMed1989

Management of carcinoma breast with conservative surgery and radiation therapy-experience in a developing country.

Between 1980 and 1987, 14 patients with breast cancer who refused mastectomy were treated at the V.N. Cancer Centre, Coimbatore, with excision of the lump, followed by radiation therapy and adjuvant chemotherapy/hormonal therapy. No attempt was made to boost the tumour bed with interstitial implants or electron beam for want of these facilities. No patient developed local or loco-regional disease or distant metastases during the period of follow-up which ranged between 10 and 76 months. Ten of the 14 patients have been followed up for more than two years. Most published data on breast-conserving treatment for cancer breast are from the U.S., UK and Europe. There are not many papers published from the developing countries. This paper gives an insight into this subject in the developing countries.

Adult↗
PubMed1977

The problem of aflatoxic human disease in parts of India-epidemiological and ecological aspects.

An outbreak of a disease characterised by jaundice, rapidly developing ascites and portal hypertension associated with 20 p. 100 mortality rate was investigated in 1974. Analysis of food samples revealed that the disease outbreak was due to the consumption of maize (corn) heavily infested with the fungus Aspergillus flavus. Unseasonal rains prior to harvest, chronic drought conditions, poor storage facilities and ignorance of dangers of consuming fungal contaminated food seem to have caused the outbreak. The level of aflatoxin in food samples consumed during the outbreak was ranging between 2.5 and 15.6 microgram/g. Anywhere between 2 and 6 mg of aflatoxin seems to have been consumed daily by the affected people for many weeks. In contrast, during 1975, analysis of corn samples from the same areas revealed very low levels of aflatoxin, viz., less than 0.1 microgram/g. This was in line with the absence of major outbreak in 1975.

Adolescent↗
PubMed1976

Resistance of cold-exposed rats to aflatoxin.

Male rats kept at a temperature of 4 degrees-5 degrees C were refractory to a lethal dose of aflatoxin compared to animals at 20 degrees-21 degrees C which exhibited a high mortality and marked liver damage. It is suggested that this decreased susceptibility is mediated through a stimulated microsomal drug-metabolizing system in cold environment.

Aflatoxins↗
PubMed1975

Microsomal metabolism as a determinant of aflatoxin toxicity.

The evidences to incriminate the possible role of microsomal drug metabolizing system in aflatoxin toxicity in rat have been reviewed. It is suggested that an effective drug metabolism results in decreased acute toxicity and the products of metabolism are more carcinogenic than the native toxin to the rat liver.

Aflatoxins↗
PubMed1975

Hepatitis due to aflatoxicosis. An outbreak in Western India.

Parts of Western India have experienced an outbreak of hepatitis affecting man and dogs and characterised by jaundice, rapidly developing ascites, portal hypertension, and a high mortality-rate. The disease was associated with the consumption of maize contaminated heavily with Aspergillus flavus. Analysis of contaminated samples showed that affected people could have consumed between 2 and 6 mg. of aflatoxin daily over a period of a month. A specimen of liver obtained at necropsy showed bileduct proliferation and giant cells. The disease appears to be a result of aflatoxicosis.

Adult↗