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Biomedical subjects

T Parveen

Publications and source records attributed to T Parveen.

13 recordsLinked to original sources
PubMed1998

Inhibition of restraint-induced anorexia by injected tryptophan.

Tryptophan injected at doses of 50mg/kg did not alter 24 h cumulative food intake and growth rate in rats. A single episode of 2 h restraint stress decreased food intake and growth rate of saline and tryptophan injected rats. The decreases of both food intake and growth rate were smaller in tryptophan injected (food intake 23.9% p<0.05; growth rate 2.9% p<0.05) than saline injected (food intake 78.5% p<0.01; growth rate 6.1% p<0.01) rats suggesting that tryptophan administration inhibits restraint-induced anorexia. Following an acute challenge with 2h restraint increases of 5-hydroxytryptamine (5-HT; serotonin) and 5-hydroxyindoleacetic acid (5-HIAA) but not tryptophan were greater in tryptophan injected than saline injected rats. The findings imply that tryptophan-induced increases of brain 5-HT and 5-HIAA have little effect on functional serotoninergic activity under basal conditions but a facilitatory effect on functional response occurs in conditions of increased serotoninergic neuronal activity such as during stress.

Animals↗
PubMed1998

The neurochemical profile of long term oral administration of moclobemide.

Moclobemide, a benzamide derivative, predominantly inhibits the A form of monoamine oxidase (MAO) and its MAO binding is reversible. Acute administration of moclobemide has been shown to induce an increase in brain levels of monoamines and a concomitant decrease in their respective metabolite. In the present study, the drug was administered to rats orally in drinking water at doses of 0.5-1.0 mg/day/rat of an average weight of 250 g for three weeks. This was equivalent to the recommended human dose of 150-300 mg/day. The drug administration did not alter food intake, growth rate and activity of rats. Brain levels of 5-hydroxytryptamine (5-HT) and dopamine (DA) increased. However, increases in 5-hydroxyindoleacetic acid (5-HIAA), dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) as reported in acute studies were not observed following chronic drug administration in the present study in addition, an increase in brain levels of tryptophan also occurred. Neurochemical profile of long-term moclobemide administration is explainable in terms of an inhibition of MAO activity, increased availability of 5-HT precursor tryptophan and decreased egress of monoamine metabolites.

Journal Article↗
PubMed1998

Neurochemical and behavioural effects of long term intake of tea.

Tea consumption in many cases is the main source of caffeine intake in humans. In the present study neurochemical and behavioural effects of long-term tea intake are monitored in rats. Long-term tea administration did not alter plasma tryptophan (TRP) but significantly attenuated brain TRP and 5-hydroxytryptamine (5-HT, serotonin) levels. Brain 5-hydroxyindole acetic acid (5-HIAA) was comparable in both tea-treated and control rats. An increase in home cage activity was observed after one week in rats taking tea as sole source of liquid, whereas no change on the activity was observed in an open field. Caffeinism has been associated with depression. The decreases of brain monoamine metabolism observed in present study are discussed as lowering of mood observed in tea or coffee consumers.

Journal Article↗
PubMed1994

Brain regional serotonin synthesis following adaptation to repeated restraint.

A single 2 h episode of restraint stress decreased food intake and growth rate of rats. These deficits were not observed after five restraint periods of 2 h a day, suggesting that adaptation occurred. An acute challenge with 2 h restraint increased 5-hydroxytryptamine (5-HT) synthesis rate in the cortex, hypothalamus, midbrain and hindbrain of previously unrestrained rats, but not those adapted to 5 days of 2 h daily restraint. Hippocampal and striatal 5-HT synthesis was not increased significantly by 2 h restraint in previously unrestrained rats but was increased and decreased, respectively, in rats exposed to five 2 h daily restraints, when they were restrained on the sixth day. The findings suggest an important role of 5-HT particularly in the hippocampus, in adaptation to stress.

5-Hydroxytryptophan↗
PubMed1994

Enhancement of hepatic tryptophan pyrrolase activity and decreases of open field locomotion following single and repeated administration of high doses of caffeine in rats.

In view of a possible role of kynurenine in caffeine-induced anxiety syndrome, the effects of single and repeated administration of caffeine on hepatic tryptophan (T)-pyrrolase activity are investigated. Single administration of caffeine at doses of 80 mg/kg decreased open field locomotion and increased hepatic T-pyrrolase activity. Locomotor stimulating effects of 80 mg/kg caffeine, monitored in the home cages of rats, were attenuated following daily administration of caffeine for 5 days. Open field locomotor activity of rats and its caffeine-induced decrement were also attenuated following 5 daily administrations of caffeine on the 6th day. Basal levels of hepatic T-pyrrolase activity increased after 5 daily administrations of caffeine on the 6th day. Acute administration of caffeine did not further elevate hepatic T-pyrrolase activity in 5 day caffeine injected rats. Drug adjuvants decreasing hepatic T-pyrrolase activity may prove valuable for extending the clinical utility of caffeine.

Animals↗
PubMed1993

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue arising in the kidney.

We describe a malignant lymphoma arising in the kidney that exhibited clinical and histologic features of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Clinically, the neoplasm involved the kidney and one perirenal lymph node (stage IIE) and did not recur or disseminate following nephrectomy, lymphadenectomy, and local radiation therapy. Histologically, the neoplasm recapitulated the features of low-grade B-cell lymphomas of MALT at other sites. The neoplastic cells resembled centrocyte-like cells, some of which formed lymphoepithelial lesions with renal tubules, and reactive lymphoid follicles were scattered within the neoplasm. The neoplastic cells expressed monotypic cytoplasmic Ig kappa. Low-grade B-cell MALT lymphomas arising in the kidney are rare. Their occurrence further demonstrates the diversity of anatomical sites that may be involved by MALT lymphomas. In addition, this neoplasm also had histologic and cytologic features resembling those of monocytoid B-cell lymphoma, supporting the hypothesis that low-grade B-cell lymphomas of MALT and monocytoid B-cell lymphomas are closely related and may be two morphological manifestations of the same neoplasm.

Aged↗
PubMed1993

Intracranial lipomas with teratomatous elements.

We report two cases of patients with intracranial tumors that share features with lipomas and teratomas. Although rare reports of lipomas with "hypertrophic nerves" and "teratoid tumors" have been recorded, these two cases are unusual because they contain mature neuroectoderm (choroid plexus, peripheral nerve) and mesoderm (skeletal muscle). The findings are discussed and modern classification schemes are presented. We believe that the cases are examples of a transition between lipoma and teratoma.

Adult↗
PubMed1992

Benign fibrous tumor of the tunica vaginalis testis. Report of a case with light, electron microscopic, and immunocytochemical study, and review of the literature.

Benign fibrous tumor of the tunica vaginalis testis is an uncommon lesion of unknown pathogenesis and histogenesis, frequently described as fibrous pseudotumor. We describe a case of a fibrous tumor of the tunica vaginalis testis studied with light, immunocytochemical, and electron microscopy in a 64-year-old man who also developed a metachronous renal cell carcinoma. To our knowledge, this is the first such case to be presented. We describe the cell of origin of this rare entity and its similarity to fibrous tumors of pleura and extrapleural sites, with a review of the English-language literature and emphasize that not all intrascrotal tumors are malignant.

Fibroma↗
PubMed1989

Acquired cystic disease of the kidneys and renal cell carcinoma in chronic renal insufficiency without dialysis treatment.

We report 3 cases of acquired cystic disease of the kidneys with associated renal carcinoma in 2 of the cases. In all 3 cases, the patients had chronic renal insufficiency due to hypertension but had never required dialysis. Review of 176 reported cases of acquired cystic disease of the kidneys and renal tumors disclosed that 18 patients (including 1 previously reported by us) had never received dialysis treatment. These cases support the hypothesis that acquired cystic disease of the kidney is not restricted to patients treated with maintenance dialysis. Among the 18 patients, hypertension was the most common underlying cause of renal failure. Patients with chronic renal failure due to or associated with severe hypertension should be monitored carefully for the development of both renal cysts and tumors even though they have not started on chronic dialysis.

Aged↗
PubMed1986

Population dynamics of some Pakistan mosquitoes: temporal changes in reproductive status, age structure and survivorship of Anopheles culicifacies, An. stephensi and Culex tritaeniorhynchus.

The reproductive biology and age-structure of female Anopheles culicifacies, An. stephensi and Culex tritaeniorhynchus were studied at rural Punjabi villages near Lahore, Pakistan, during 1976-1980. Both Anopheles remained gonotrophically active throughout the year with blood-fed, gravid, parous and virgin females collected during all months. Culex tritaeniorhynchus populations bifurcated into reproductively active, non-overwintering and reproductively inactive, overwintering populations in October and/or November. Most female Cx. tritaeniorhynchus overwintered as inseminated nullipars with ovaries arrested at follicular State I; however, host-seeking and parous females were collected during every month of the year. Survivorship was calculated for each species by three methods and was negatively correlated with mean monthly ambient temperature. The ovarian tracheolation method provided inadequate estimates of parity for females collected at diurnal resting sites which refed the night of oviposition, but was suitable for Cx. tritaeniorhynchus females captured at bovid baits. The dilatation method of Polovodova was applied to all three species and yielded survivorship patterns which were constant with age and agreed well with a log-linear model. Anopheles culicifacies survived longer than did An. stephensi and thus was considered a better vector of malaria. Age-specific survivorship tables were constructed for all three species for those periods of the year when the gonotrophic rhythm was constant and generations were overlapping.

Animals↗
PubMed1980

Anopheles culicifacies Giles: a release-recapture experiment with cohorts of known age with implications for malaria epidemiology and genetical control in Pakistan.

A mark-release-recapture experiment with the progeny of wild collected Anopheles culicifacies was performed during the monsoon season of 1978 at the village of Khano-Harni, a malarious area situated in Lahore District, Punjab Province, Pakistan. The recapture rates of males and females released at breeding and resting sites were statistically comparable and totalled 8.0% for females and 5.9% for males collected resting in houses and cattle sheds. Mating occurred mostly on the night following the evening of release when the females were about two days old. Insemination rates for females released at resting and breeding sites were statistically comparable. The initial gonotrophic cycle required four days; subsequent cycles occurred at two-day intervals with re-feeding on the same night as oviposition. Constant daily survivorship estimated from the decline in recaptures per day was 0.568 for females and 0.676 for males. Female survivorship estimated by vertical age grading methods ranged from 0.472 to 0.820. Horizontal life tables were calculated from the decline in recaptures and from vertical age-grading techniques and indicated that female or male life expectancy at emergence was less than 2.5 days. Population size was calculated using the Lincoln Index, Jackson's positive and negative methods and Itô's modification of Jackson's positive method and averaged from 1045.5 to 1049.6 females and from 449.1 to 1323.7 males. The relationship of these results to malaria transmission and genetical control is discussed.

Animals↗