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Biomedical subjects

M Ghosh

Publications and source records attributed to M Ghosh.

At least 127 records · Page 7Linked to original sources
PubMed1990

Annual pineal and testicular cycle in the Indian jungle bush quail, Perdicula asiatica, with reference to the effect of pinealectomy.

The annual testicular cycle of Perdicula asiatica has a single peak which appears to be under the dual influence of the environment and the pineal gland. An inverse relationship was noted between pineal gland and testicular weight cycle. Pinealectomy, after 60 days, retarded testicular growth in the progressive phase, inhibited activity of the gonad in the active phase, and accelerated gonadal regression in the regressive phase. This complete study of short-term pinealectomy effects on the annual testicular cycle of a tropical bird for the first time reflects both the essentialness of the pineal gland to the maintenance of proper testicular cyclicity under natural environment conditions and the progonadotropic nature of the pineal gland.

Animals↗
PubMed1990

Corneal changes in Tay-Sachs disease.

Tay-Sachs disease is a well-known inherited disease leading to an accumulation of gangliosides in the brain and retina. Our report is based on a case of Tay-Sachs disease in a non-Jewish infant where pathologic changes were noted in corneal endothelium as well as in the retina.

Corneal Diseases↗
PubMed1990

Acanthamoeba keratitis in a soft-contact-lens wearer.

Acanthamoeba keratitis is an uncommon but potentially devastating complication of contact lens wear. We present a case of Acanthamoeba keratitis in a soft-contact-lens wearer successfully treated with long-term medical therapy and penetrating keratoplasty. To our knowledge this is the first case of Acanthamoeba keratitis diagnosed in Canada.

Acanthamoeba↗
PubMed1989

Effect of treatment with aromatase inhibitor 4-hydroxandrostenedione on the nonhuman primate menstrual cycle.

4-Hydroxyandrostenedione (4-OHA) is a potent inhibitor of rat ovarian and human placental aromatase activity as assessed in vitro and has been shown to suppress ovarian estrogen secretion in vivo in rats. The compound inhibited extragonadal aromatization in male rhesus monkeys and reduced plasma levels of estradiol in postmenopausal women with advanced, metastatic breast cancer. Furthermore, 4-OHA caused disease remission in these patients. Prior to using this compound in premenopausal patients, the present study was carried out to determine whether 4-OHA affects the menstrual cycle by inhibiting ovarian estrogen production in nonhuman primate species. Four baboons (Papio anabis) exhibiting regular menstrual cycles were studied. Blood samples were collected daily throughout a control menstrual cycle and during treatment with daily s.c. injections of 4-OHA. Menstruation was not observed in three of four animals during treatment and did not resume until cessation of 4-OHA administration. The midcycle surge of estradiol which averaged 411 pg/ml in the control menstrual cycle was reduced during 4-OHA treatment by a mean of 49% of control. Thereafter, with continued 4-OHA treatment, serum concentrations of estradiol were significantly reduced below the basal control level [75.3 +/- 5.6 (SE) pg/ml] and were very low or undetectable. Perineal turgescence, an index of estrogenicity, was inhibited by 4-OHA administration. The preovulatory surge of serum luteinizing hormone, which averaged 114 ng/ml during the control cycle, appeared normal in three of four animals following 12 to 14 days of 4-OHA administration, but no luteinizing hormone surge occurred with continued 4-OHA administration. The results indicate that, although 4-OHA reduces ovarian estrogen formation during the first cycle, treatment for a second consecutive cycle appears to be necessary for maximal suppression.

Androstenedione↗
PubMed1989

Effect of 17 beta-estradiol on different parts of central nervous system of female Singi fish (Heteropneustes fossilis Bloch) in relation to reproductive stages.

Effects of different doses of 17 beta-estradiol (1, 2 and 4 micrograms/g, 3 consecutive days injections) on the protein, RNA and DNA contents of cerebrum (CB), cerebellum (CE), midbrain (MB), medulla oblongata (MO) and spinal cord (SC) of female non-vitellogenic (NV) and vitellogenic (V) Singi fish (Heteropneustes fossilis Bloch) were investigated. The amounts of these macromolecules in all these substructures of the central nervous system were enhanced on the 4th and/or 7th day in NV fish by estradiol depending on the dose. The higher dose(s) caused more marked effect. The dose of 1 microgram/g was ineffective in case of protein and mostly in case of DNA. There was no enhancement of protein content with any dose of estradiol on the 4th day in CE, MB, MO and SC, but in CB 4 micrograms of estradiol/g increased the protein content on this day. However, the increase was marked on the 7th day in all substructures. The enhancement of RNA content was elicited earlier (4th day) even with lower dose of 1 microgram/g in NV fish in most of the substructures, except MO. With exception of this substructure again, the DNA content of any part did not increase with the hormone on the 4th day with 1 microgram of estrogen/g. The changes in protein and nucleic acid contents of the different substructures of central nervous system in V fish with 17 beta-estradiol were mostly opposite to those in NV fish. Depending on the dose and time, protein and RNA contents of these parts decreased with estradiol in V fish. No change in DNA content, however, was found, except MO where this cellular constituent was surprisingly enhanced on the 4th and 7th day with all doses of estradiol used. The spinal cord of V fish did not show any change in RNA and DNA contents with the hormone. Thus a reproductive stage-specificity of estrogen action in fish brain is documented.

Animals↗
PubMed1989

Effect of pinealectomy and 5-methoxyindoles on Harderian gland activity of the Indian Jungle bush quail Perdicula asiatica.

The present study reveals that the annual Harderian gland weight cycle of P. asiatica has a direct relationship with the testicular cycle and an inverse relationship with the pineal gland cycle. Pinealectomy resulted in a significant decrease of the Harderian gland weight during the recurdescence (March-May) and active (April-June) phases. Subcutaneous implantation of melatonin (aMT) and 5-methoxytryptamine (MT) brought about a significant reduction during the recrudescence and active phases whereas subcutaneous injections of aMT, MT and 5-methoxytryptophol (ML) reduced Harderian gland weight effectively during the morning as well as in the evening hours in the active and inactive phases.

5-Methoxytryptamine↗
PubMed1988

Evaluation of serum fucose level in patients with oral cancer.

Serum fucose level was determined in 57 oral cancer patients and 25 normal persons before any treatment was performed. There was a significant rise in these levels in patients with oral cancer, and they correlated well with the clinical stages. This correlation is found to be exceedingly helpful in establishing the presence of and evaluating the extent of oral cancer.

Adult↗
PubMed1988

Effect of 5-methoxyindoles on testicular function of the Indian jungle bush quail Perdicula asiatica.

Melatonin (aMT) implantation during testicular inactive phase (January-March) brought an early initiation of testicular development in Perdicula asiatica. However, during the recrudescence (March-May), active (April-June), and regressive (May-July-September) phases both aMT and 5-methoxytryptamine (MT) implantation had inhibited testicular weight and activity significantly. Subcutaneous injections of aMT, MT and 5-methoxytryptophol (ML) during morning (7.30 a.m.-8.00 a.m. and evening (4.30 p.m.-5.00 p.m.) could not bring about any significant effect on the weight or activity of the testes during the inactive (January-February) phase, while inhibited testicular weight and activity during the active (May-June) phase when administered in the morning as well as in the evening hours.

5-Methoxytryptamine↗
PubMed1988

Retinal cavernous hemangioma.

We describe an 8-year-old girl with cavernous hemangioma of the retina, a rare condition. The patient was followed for 7 years and showed change in her clinical appearance.

Child↗
PubMed1988

Pathological study in a female carrier of choroideremia.

We present the pathological findings in one eye of a 68-year-old woman with choroideremia. There was widespread malformation of the outer receptor segments. A second retinal finding was patches of atrophy, involving loss of the retinal outer cell layer. The pigment epithelium was intact, although there were areas showing depigmentation of the cells. The choriocapillaris was present. The findings suggest that the primary defect in choroideremia lies at the retina-pigment epithelium interface. Possible mechanisms are discussed.

Aged↗
PubMed1987

Occurrence, identification and possible significance of ornithine lipid in Thiobacillus ferrooxidans.

An ornithine containing aminolipid has been found in Thiobacillus ferrooxidans grown in ferrous sulfate medium, which was purified and estimated at four main phases of growth. GLC analysis of ornithine lipid has revealed the existence of mainly C18:1 and C22:1 fatty acids. The infrared spectra showed the existence of both amide and ester linkages in the aminolipid. The major ester linked fatty acid was C22:1. The interaction of ornithine lipid with membrane was investigated by delipidation of the membrane particles, which resulted in the perturbation of the activities of the three enzymes of iron oxidation system. The activities could be restored to the lipid depleted particles by preincubation with a dispersion of purified ornithine lipid together with coenzyme Q8. The kinetic parameters of the enzyme activities were also affected by delipidation which was significantly altered in the reconstituted particles by this lipid, thus indicating a possible role of ornithine lipid in iron oxidation system.

Chromatography, Gas↗
PubMed1987

Effect of melatonin on gonads, body weight, and luteinizing hormone (LH) dependent coloration of the Indian finch, Lal munia (Estrilda amandava).

Four doses of melatonin were administered intramuscularly over 30 days in separate groups of intact adult male Lal munia, Estrilda amandava, during mid-day (1300 hr) and mid-night (0100 hr) in separate sets during the month of August (late progressive phase), and their effects were studied on the body weight, gonadal and thyroidal activities, and luteinizing hormone (LH)-dependent plumage and beak pigmentation. Melatonin, irrespective of its dose and the time of administration, invariably induced complete inhibition of seasonal gonadal growth and activity, and also the LH-dependent plumage pigmentation. Melatonin had no effect on LH-dependent beak coloration. The inhibitory effect of melatonin on the body weight growth was found to be dependent on the time of administration and the dose of the hormone. Melatonin inhibited the thyroid activity in all the groups. These findings seem to suggest that while melatonin influences gonadal activity, body weight growth, and thyroid activity by acting directly at the hypothalamo-hypophyseal complex, it counteracts the effect of LH at the feather papillae level. Further, synthesis and/or release of FSH seems to be more sensitive to melatonin than that of LH. However, the metabolic action of melatonin might be species specific.

Animals↗