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Biomedical subjects

S Bose

Publications and source records attributed to S Bose.

At least 145 records · Page 8Linked to original sources

Aflatoxin-induced structural chromosomal changes and mitotic disruption in mouse bone marrow.

Ascorbic acid in a dose proportional to the human therapeutic dose (500 mg/day), when administered to Swiss albino mice along with a dietary concentration of aflatoxin B1, decreases the incidence of toxin-induced chromosomal abnormalities in the bone marrow cells. Treatment with the toxin alone (6 and 12 weeks) did not produce any differences in clastogenicity. The vitamins, when administered along with the toxin for 6 weeks, seemed to nullify more of the structural changes than of the mitotic disruptions. In 12-week treatment, more structural and fewer disruption-type abnormalities were found.

Aflatoxins↗

Right-sided aortic arch presenting as refractory intraoperative and postoperative wheezing.

A 29-year-old woman presented with severe refractory intraoperative wheezing and airflow limitation that resolved spontaneously. Contrast-enhanced computed tomographic (CT) scan of the thorax confirmed a right-sided aortic arch. Variable intrathoracic large airway obstruction that worsened markedly when the patient was in a supine position and slightly more following intravascular volume expansion was shown on flow-volume studies. We postulate the right-sided aortic arch caused airflow obstruction that worsened intraoperatively because of position and intravenous fluids.

Adult↗

The role of glutathione in evaluating the efficacy of antimetabolites in transplanted tumors.

Levels of glutathione (GSH) in tumor cells play an important role in determining the clinical responses to certain anticancer agents. In the present work 5-fluorouracil and 5-fluorodeoxyuridine have been used as antineoplastic agents against transplanted Ehrlich ascites carcinoma. The glutathione levels in the tumor cells and liver tissues of the host animals have been studied by a specific histofluorescence method. Significant changes have been observed in the glutathione level of the host, tumor bearing and treated group of animals, the implications of which have been discussed.

Animals↗

A light & electron microscopic study on apoptotic bodies in acute aflatoxin B1 induced injury in the rat liver.

A subnecrogenic dose of aflatoxin B1 (AFB1) was injected intraperitoneally into 8-10 wk old male rats of the Holzman strain. Cytoplasmic and sinusoidal eosinophilic bodies were seen in the liver which appeared at 30 h and reached a maximum at 48 h. Electron microscopically some of the cytoplasmic structures were seen to be of mitochondrial origin whereas others resembled apoptotic bodies. The sinusoidal bodies were similar to apoptotic bodies.

Aflatoxin B1↗

Pseudo-Meigs' syndrome secondary to broad ligament leiomyoma: a case report.

An unusual and rare case of broad ligament leiomyoma with massive ascites and bilateral pleural effusion is described. The ascites and pleural effusion resolved dramatically following removal of the tumor. Patients with pseudo-Meigs' syndrome may present a diagnostic problem as they masquerade as carcinoma with malignant effusions. Thus they should always be considered for exploratory laparotomy.

Ascites↗

Response of adult Necator americanus to some known anthelminthics in hamsters.

Adult Necator americanus infection in laboratory hamsters (the hamster-hookworm model) was examined as an anthelminthic screening system. Three reference anthelminthics--pyrantel (PYTL), mebendazole (MBZ) and ivermectin (IVRN)--were used to assess the sensitivity of adult N. americanus and also to investigate the value of the hamster-hookworm model for predicting clinical results. Serial drug dosages were used, and the ED50 was determined from the resulting cure rates. In addition, percentage worm reductions were calculated by reference to the worm burdens in control groups. The results showed that the hamster-hookworm model was able to differentiate anthelminthics on their efficacy. Absolute activity (100% worm reduction) followed treatment with 8 mg kg-1 MBZ, 38-40 mg kg-1 PYTL and 18 mg kg-1 IVRN. Based on ED50 data of PYTL and MBZ, adult N. americanus appeared to be two to five times more sensitive than pre-adult stages. However, with IVRN the reverse appeared true. MBZ appeared to be most active and PYTL least active in terms of curing infected animals, but there were no obvious differences between the rates of worm reductions following single or multiple doses of anthelminthics. It is considered that the hamster-hookworm model will prove of value in identifying and characterizing possible new anthelminthics.

Animals↗

Fine-needle aspiration cytology of meningiomas with unusual presentations.

Meningiomas are not often aspirated unless they erode the skull, occur intraorbitally, or present as swelling in the head and neck region. We describe the cytologic findings of fine-needle aspiration cytology (FNAC) in four cases of meningioma that presented with swellings in the head and neck region. The patients underwent surgery, and the diagnosis of meningioma was confirmed. Three of the four cases were reported as aggressive meningiomas on histopathology.

Adult↗

Morphological and biochemical effects of gentamicin and cyclosporin-A on urinary cell phospholipids and phospholipases in man.

The morphology, lipid composition, and activity of sphingomyelinase (E.C. 3.1.4.12) and phospholipases A (E.C. 3.1.1.32) and C (E.C. 3.1.4.3) were studied in the urinary cells from four normal subjects, four patients receiving gentamicin (G), and four patients receiving cyclosporin-A (CsA). We report that abnormal urinary excretion of proximal tubular cells occurred in patients receiving G and CsA. Membrane-enclosed sudanophilic material and numerous vacuoles were found in the cytoplasm of the proximal tubular cells from both patients receiving G and those receiving CsA. Patients receiving G shed higher levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and sphingomyelin (SM) in the order of 78%, 38%, and 30% relative to normal. In contrast, the excretions of phosphatidylinositol (PI) and PC were 50% and 30% lower, respectively, in patients receiving CsA as compared to control. Sphingomyelin levels, however, were moderately elevated in these patients' urinary renal tubular cells. The activity of acid sphingomyelinase was one half the normal level in the cells of patients receiving G and CsA. The most striking result was a tenfold decrease in the activity of neutral sphingomyelinase in patients receiving G. In contrast, the activity of neutral sphingomyelinase in patients receiving CsA was similar to control. Phospholipase A activity was decreased and increased 35% and 15%, respectively, in urinary proximal tubular cells from patients receiving G and CsA. We conclude that deficient neutral sphingomyelinase activity precedes phospholipid (PL) overloading and gross pathological changes in patients receiving gentamicin but not in patients receiving cyclosporin-A.

Adult↗

Clinical budgeting and drug management on long-stay geriatric wards.

Over-prescribing on long-stay wards for the elderly is a common problem. A scheme of senior doctor surveillance of prescribing on long-stay wards in a district general hospital is described, which involved stopping all drugs except those considered essential. A reduction of over 50% in the number of drugs taken per patient, and a saving of 34% in drug costs was achieved, without detriment to patients' well-being. Increased drug utilization on some wards is considered to occur because of the ward sister's demand for patients to be given drugs such as sedatives and tranquilizers. Regular re-education of nursing and junior medical staff to reduce over-prescribing is recommended.

Aged↗

Fluorescence characteristics of photoinhibition and recovery in a sun and a shade species of the red algal genus porphyra.

The effects of light treatment (2000 micromole photons per square meter per second) for varying periods (up to 60 minutes) on chlorophyll fluorescence characteristics and light-limited rates of O(2) evolution were examined in two Porphyra species. Brief light exposures (5-60 seconds) produced a large decrease in variable fluorescence which was not accompained by photoinhibition of light-limited O(2) evolution rates. This rapid decrease in variable fluorescence was suppressed by carbonylcyanide m-chlorophenylhydrazone, indicating that it was related to formation of a proton gradient across the thylakiod membranes. A second phase of fluorescence quenching started after 5 minutes of illumination in the case of the shade species, Porphyra nereocystis Anderson, and after 30 minutes of illumination in the case of the sun species, Porphyra perforata J. Agardh. The rate of fluorescence quenching in the second phase was similar to the rate of photoinhibition of light-limited O(2) evolution in both cases. The dark recovery of variable fluorescence in light-treated plants was also biphasic consisting of a rapid first phase and a slower second phase in both the Porphyra species. Recovery of P. perforata was more complete than that of P. nereocystis over the same recovery period. This greater capacity for recovery could represent a mechanism by which P. perforata is more resistant to photoinhibition than P. nereocystis.

Journal Article↗

Changes in the Cationic Regulation of Structure and Function in Thylakoids Isolated from Wheat Seedlings Treated with BASF 13.338.

When wheat seedlings (Triticum vulgare cf HD 2189) were grown in the presence of BASF 13.338 (4-chloro-5-[dimethylamino]-2-phenyl-3[2H]-pyridazinone), there was a decrease in the ratio of linolenic acid to linoleic acid in the thylakoid membrane lipids (JB St John 1976 Plant Physiol 57: 38) and an increase in the ratio of photosystem II to photosystem I (RM Mannan, S Bose 1984 Photochem Photobiol 41: 63). Accompanying these gross structural changes were alterations in the cationic regulation of structure and functioning of the thylakoid membranes: (a) Mg(2+)-induced increase in the room temperature fluorescence was totally absent; (b) Mg(2+)-induced increase in absorbance at 560 nm, indicative of granal stacking, was slightly higher in thylakoids isolated from the BASF 13.338 treated plants suggesting an increased degree of stacking; and (c) absorption changes in the red and Soret regions of the absorption spectrum, normally resulting from the addition of divalent cation or alkyl anion, or from osmotic shrinkage were almost totally absent in thylakoid membranes isolated from BASF 13.338 treated plants. These observations have been interpreted in terms of: (a) significant alterations in the lipid matrix of the thylakoids from treated plants, (b) absence of cation-induced reorganization of the pigment-protein complexes in the horizontal plane of the treated thylakoid membranes suspended in low salt medium, and (c) absence of dynamic changes even within the individual pigment-protein complexes of treated thylakoids.

Journal Article↗

Factors influencing corneal involvement in leprosy.

Corneal involvement in leprosy is known to be influenced by factors such as lagophthalmos, ectropion, and corneal anesthesia. In the present study conducted on 400 eyes of leprosy patients, observations were made on tear film abnormalities, and their relation to the above-mentioned factors was analyzed. The abnormality of tear film breakup time (BKUT) was found to be clinically more significant (47.2%) than a Schirmer's test alone (24.5%), and this finding was of greater significance in the lepromatous form of leprosy. An abnormal BKUT reflects a decreased mucin secretion by the conjunctival goblet cells. Tear film abnormalities in association with lagophthalmos, corneal anesthesia, concomitant ocular diseases, and environmental factors such as high relative humidity have been identified as factors contributing to corneal involvement in leprosy in India. It is not surprising that with so many mechanisms of corneal involvement the clinical manifestations are diverse, and all forms of pathological changes may contribute to corneal morbidity.

Cornea↗