PubMed Health⌕ Search

Biomedical subjects

V S Lalitha

Publications and source records attributed to V S Lalitha.

At least 37 records · Page 2Linked to original sources
PubMed1988

Carcinogenicity studies of masheri, a pyrolysed product of tobacco.

The carcinogenicity of two commonly used brown and black varieties of masheri, a pyrolysed tobacco product, was studied by feeding the masheri through the diet at a 10% level to three different animal species of both sexes. In Sprague-Dawley rats, only brown masheri was used, while in Swiss mice and Syrian golden hamsters both varieties were used. In all the three species, forestomach papillomas were induced as a result of masheri treatment. In rats, 37% of animals showed forestomach papillomas while in mice and hamsters the incidence was 42-47% and 25-43%, respectively. No malignant changes were observed in any of the groups except 2/23 male hamsters showed forestomach carcinoma in the black masheri diet group.

Adenoma↗
PubMed1988

Megaoesophagus in ICRC mice.

The occurrence of megaoesophagus in ICRC/HiCri mice afforded opportunities to study the genetics and histology of this condition. The anomaly was found to be inherited as a recessive character. Histology indicated abnormality in the myenteric plexus.

Animals↗
PubMed1987

Carcinogenicity of diethylnitrosamine in vitamin-A-deficient mice.

The effect of suboptimal levels of dietary vitamin A on diethylnitrosamine (DEN) carcinogenesis was studied in BALB/c and Swiss mice. Two different dietary regimens were employed to induce vitamin A deficiency and DEN was administered by gavage at 2 dose levels: 0.6 mg/kg as a single dose and 200 mg/kg in 4 divided doses. Shark liver oil (SLO) which was the main source of vitamin A in the standard diet, was deleted in one regimen and reduced to 25% in the other. The mice maintained on the former diet were given a high dose of DEN and those on the latter diet received a low dose. In both strains the deficient mice had a greater tumour incidence than those on standard diet with a marginal reduction in the latent period. At the low level of DEN there was shift in organotrophy, i.e. from liver in controls to lung in the vitamin-A-deficient mice of BALB/c strain. With the higher dose, lung adenomas predominated in deficient as well as control groups in both the strains. Forestomach carcinomas appeared in deficient mice and not in the controls.

Administration, Oral↗
PubMed1987

Receptors for epidermal growth factor and estradiol in canine mammary tumors.

Both growth factors and steroid hormones are known to be associated with breast cancer. We have studied the epidermal growth factor receptor (EGFR) in canine mammary tumors and have shown the presence of a single class of 125I-EGF binding receptor sites in 9 out of 13 (70%) tumors, using Scatchard plot. The dissociation constant (KD) was 10(-9)M. An inverse correlation between EGFR and estrogen receptor (ER) was observed in 54% of the tumors. Our data suggest that EGFR might be used as a biochemical marker in canine mammary tumors.

Animals↗
PubMed1987

Dapsone neuropathy--report of three cases and pathologic features of a motor nerve.

We report the clinical features, electrophysiologic findings, and dapsone and isoniazid excretion studies in three young people who ingested excessive amounts (2-4 times the prescribed dose) of dapsone for hypopigmented macules and who developed, subacutely, progressive motor neuropathy a few months later. Pathologic studies on a biopsied motor nerve confirmed the electrophysiologic conclusion of distal motor axonopathy. All made a rapid recovery in a few months after dapsone was stopped, although electrical abnormalities persisted. One patient was a rapid acetylator of isoniazid.

Adolescent↗
PubMed1986

Effect of irradiation on ethyl nitrosourea induced neural tumours in Wistar rat.

Wistar rats received 2 Gy whole body irradiation followed immediately by 10 mg/kg of ethyl nitrosourea (ENU) on the day of birth. Out of 33 rats which were given ENU alone 14 developed 22 tumours of the nervous system, out of which 15 (68.2%) were gliomas and 7 (31.8%) were Schwannomas. Out of 34 rats which were given both irradiation and ENU 12 were found to harbour 15 neural tumours out of which 14 (93.3%) were gliomas and 1 (7.1%) was a Schwannoma. The pretreatment with irradiation seems to have resulted in selective suppression of Schwannoma induction.

Animals↗
PubMed1985

Acute toxicity of folic acid in mice.

The toxicity of folic acid (PGA) was studied in different inbred strains of mice. LD50 values of PGA by the i.p. route showed a unique toxicity pattern. In some strains, convulsions, ataxia and weakness were observed. Histopathological study in strains S/RVCri, BDF1, DBA/2 and DBA/2fNCri showed acute renal tubular necrosis.

Animals↗
PubMed1985

Chilli extract treatment and induction of eye lesions in hamsters.

On chronic administration of 20 microliter of chilli extract to the cheek pouch of hamsters till death, 23% of the hamsters developed shrunken eye balls and closing of the eyelids. This effect was not observed in hamsters which received a single application of the potent carcinogen methylacetoxymethyl nitrosamine (DMN-OAC) (2 mg/kg body wt.) prior to repeated treatment with chilli extract. Vitamin A levels decreased significantly in the liver tissue of chilli-treated and carcinogen + chilli-treated groups compared to absolute alcohol-treated and untreated groups, while serum Vitamin A values decreased only in the DMN-OAC + chilli-treated group. However, Vitamin A levels do not seem to be linked causally with the effect on the eyes of chilli-treated hamsters, because these hamsters had circulating levels of Vitamin A comparable to those observed in untreated and alcohol-treated groups.

Animals↗
PubMed1979

Scanning electron microscopy of in vitro grown cells from experimentally induced neurogenic tumors.

Serially transplanted neurogenic tumors of experimental origin were explanted in vitro and analyzed by scanning electron microscopy. In explants of intracerebrally transplanted gliomas, small stellate cells with branching processes were observed; in transplanted tumors of the peripheral nervous system, slender bipolar cells as well as fibroblasts emerged. The stereoscopic features were compared with the picture of conventional light microscopy. The findings are consistent with the assumption of the glial derivation of CNS-tumors induced with neurotropic alkylating carcinogens. The peripheral tumors are composed of Schwann-cell like elements and fibroblasts. The significance of the results for the cytogenetic derivation of brain tumors are discussed.

Animals↗
PubMed1979

Reactive glioma in intracranial sarcoma: a form of mixed sarcoma and glioma ("sarcoglioma"): report of eight cases.

The clinicopathologic features of eight new cases of combined intracranial sarcoma and glioma are described. This type of mixed cerebral tumor is histologically characterized by a peripheral distribution of the gliomatous elements in relation to a more centrally situated meningeal or intracerebral sarcoma, and by the frequent presence of gradual transitions from reactive to frankly neoplastic astrocytes. In six of the eight cases, the additional development of either infiltrating astrocytoma or frank glioblastoma in the adjacent brain was demonstrated; this was interpreted as a further expression of malignant glial reaction. It is suggested that these tumors be termed "sarcogliomas" to distinguish them from the type of mixed glioma and sarcoma that has recently been redesignated "gliosarcoma."

Adolescent↗
PubMed1975

Dual infections of mice: visceral larva migrans and sublethal infection with Japanese encephalitis virus.

Experiments in 3 weeks old albino mice with Toxocara canis and sublethal infection with JE virus established a marked synergestic effect in dually infected mice. The results are discussed to indicate the possible role of visceral larva migrans in creating exploxive outbreaks of "acute encephalopathy syndrome" in individuals having simultaneous infection with a virus (es) which, alone, might produce only mild illness. The nature of the possible mechanisms involved yet remains to be understood.

Animals↗