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Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

At least 793 records · Page 44Linked to original sources
PubMed1991

Relationship of clastogenic effects of zirconium oxychloride to dose and duration of exposure in bone marrow cells of mice in vivo.

Zirconium oxychloride was administered as a single oral dose to laboratory-bred Swiss albino mice corresponding to 1/2, 1/6 and 1/20 of the LD50 values. Bone marrow cells were screened after 6, 12 and 24h for chromosomal aberrations following an air-drying-Giemsa schedule. The frequencies of chromosomal breaks and alterations induced increased significantly at a rate directly proportional to the concentration used. The increase was also related to the period after exposure, although to a less extent than the concentration used. No direct relationship could be observed to the sex of the animal.

Administration, Oral↗
PubMed1991

Epidemiology of campylobacteriosis in a cohort of rural population near Calcutta.

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at monthly intervals. The overall diarrhoea attack rate was 19 episodes per 100 person-years with peak incidence in the 1- to 4-year-old age group (76/100 person-years). Eight (11.5%) of the total episodes were campylobacter-associated and the overall rate of campylobacter positive diarrhoeal episodes were 2.2 per 100 person-years. Of the 1002 stool samples from healthy individuals 32 (3.2/100 samples) were positive for campylobacter. The organism was most frequently isolated from children under 1 year of age both during diarrhoeal episodes (11.5 per 100 person-years) and non-diarrhoeal (11.1 per 100 samples). Multiple infections in a family were rare. In 19.4% of the occasions one or more animals were campylobacter positive. However, only in 7.7% of these occasions was a human infection recorded within 1 month after the animal was found to be positive. The study showed that the epidemiology of campylobacteriosis in this community was distinct compared to that observed in developed countries.

Adolescent↗
PubMed1991

Biosynthesis in vitro of SA-Lex and SA-diLex by alpha 1-3 fucosyltransferases from colon carcinoma cells and embryonic brain tissues.

The sialyl-fucosyl-lactosamine-epitope present in sialyl (SA)-Lex (NeuAc alpha 2-3Gal beta 1-4 [Fuc alpha 1-3]GlcNAc beta 1-3Gal beta 1-4Glc-Cer), a carcinoembryonic antigen, has been recognized recently as a ligand for the binding of leukocyte-endothelial cell adhesion molecule 1 (LECAM-1) to myeloid and tumour cell surfaces. We have recently detected the presence of an alpha 1-3 fucosyltransferase (FucT-3) activity in both embryonic chicken brain (ECB) and human colon carcinoma cells (Colo-205) which catalyses the biosynthesis in vitro of SA-Lex and SA-diLex. Fucosyltransferase activities from both sources are stimulated in the presence of divalent cations (Mn2+, Mg2+, Ca2+, Co2+ and Fe2+), although absolute metal requirement is not observed. Substrate specificity studies with this partially purified (ECB, 3000-fold; Colo-205, 100-fold) novel FucT-3 indicate the preference for terminally sialyl-substituted glycolipid acceptors, as observed by the lower Km values when sialyl-neolactotetraosyl ceramide, LM1, (Neu-Gc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4 Glc-Cer; Km = 0.048 mM) and sialyl-norhexaosylceramide, NeuGc-nLc6, (Neu-Gc alpha 2-3Gal beta 1-4 GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer; Km = 0.032 mM) were used as substrates. Fucosyltransferase from Colo-205 requires the presence of the acyl group of the ceramide moiety and an acetyl group on glucosamine in the acceptor glycolipid since lyso-LM1 was found to be completely inactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Lichen planus in childhood: a report of 17 patients.

Lichen planus is a dermatosis of unknown origin with a very limited frequency in children. Over a period of one and a half years we observed 17 cases of childhood lichen planus. The classic form of the disease as seen in adults was the most common in these children; unlike adults, however, mucosal and nail involvement was uncommon. The natural history of the disease was similar to that in adults.

Age Factors↗
PubMed1991

How bad are the symptoms and bowel dysfunction of patients with the irritable bowel syndrome? A prospective, controlled study with emphasis on stool form.

Since it is not known whether the symptoms and bowel function of patients with the irritable bowel syndrome are truly abnormal we used diaries and frequent telephone interviews over a 31 day period to assess symptoms, defecation, and stool types in 26 unselected female hospital patients with the irritable bowel syndrome, 27 women who admitted to recurrent colonic pain but had not consulted a doctor (non-complainers), and 27 healthy control subjects. Unexpectedly, abdominal pain and bloating occurred in most of the control subjects. Pain, however, was six times more frequent in the patients and was more often considered severe. Bloating occurred three times more often. Defecation was more frequent, more erratic in timing and stool form, and more likely to produce stools of extreme forms, indicating rapid fluctuations in intestinal transit time. Urgency was four times more prevalent in patients than control subjects. Straining to finish defecating was nine times more prevalent and was often accompanied by feelings of incomplete evacuation--a combination which could lead to the misdiagnosis of constipation. The normal relation between stool form and the above symptoms was distorted, possibly due to rectal irritability. Non-complainers were intermediate between patients and control subjects in almost every parameter but were closer to control subjects than to patients. Patients with the irritable bowel syndrome have real cause for complaint and their bowel function is truly abnormal.

Abdominal Pain↗
PubMed1991

Single small enhancing CT lesions in Indian patients with epilepsy: clinical, radiological and pathological considerations.

Thirty consecutive Indian patients with focal or generalised seizures and single, small (less than 10 mm), enhancing lesions on CT scans (SSECTL) were studied. Five patients (Group A) were treated with anticonvulsants alone and did not have a biopsy. In ten patients (Group B) a CT guided stereotaxic biopsy of the lesion was carried out and in the remainder (15-Group C) and excision biopsy of the lesion was carried out following CT guided stereotaxic localisation. In all patients in Group B the lesion were reported as "chronic nonspecific inflammation". In seven of 15 patients in Group C the lesions showed a cysticercus with a granuloma and in a further five the pathology was that of a "parasitic granuloma" but the parasite could not be identified. Biopsy did not reveal a tuberculoma or neoplasm in any of the patients. The lesions studied are the same as "disappearing" CT lesions reported in Indian patients, as in 12 of 15 patients in Groups A and B, who could be followed up for more than three months, the lesions had spontaneously disappeared or left calcific residues. It is concluded that in Indian epileptic patients with SSECTL cysticercosis is the commonest aetiology. A treatment protocol for these patients is suggested on the basis of the findings.

Biopsy↗
PubMed1991

An operational study on implementation of oral rehydration therapy in a rural community of West Bengal, India.

An operational study of a 3-tier strategy for implementation of oral rehydration therapy (ORT) was conducted in a block of West Bengal with 216,825 population through the existing health services facilities. All the grassroot level, health workers including their supervisors at various levels were trained regarding the management of patients of diarrhoea with mild to moderate degree of dehydration, by ORT. Another block in the same district with similar demographic features where this intervention was not provided served as control. After 22 months of observation, it was evident that despite adequate training, the performance of Community Health Guides (CHGs) and Anganwadi Workers (AWWs) was not encouraging because of the low utilization of both home available fluids (32.0%) and oral rehydration solution (18.0%) in the study area. Similarly, diarrhoea associated mortality could not be reduced significantly. Lack of motivation and failure to maintain sustained level of skill by the CHGs and AWWs constitute the major bottlenecks for the successful implementation of the programme at the community level.

Child, Preschool↗
PubMed1991

The retrocerebral endocrine complex in Diptera.

The retrocerebral endocrine glands were studied in 20 insects belonging to the three suborders of Diptera. The CC-CA complex either takes the form of a ring gland, or consists of paired CC and CA. In the suborders Nematocera and Brachycera, both types of organization are to be seen, but only ring gland organization is present in members of the suborder Cyclorrhapha. NCC I and NCC II are found only in insects with paired CC and CA. The histology of the CC and CA is described. NCA1 is clearly discernible in species with paired organization. NCA2 was seen in only one species (Tabanus speciosus), but no swelling was observed on this nerve. NAA and NAO were not present in any of the 20 species studied.

Animals↗
PubMed1991

Hypertensive primary intraventricular haemorrhage.

A case of hypertensive primary intraventricular haemorrhage is reported. The patient recovered with conservative management. To the best of our knowledge, there has been no previous report of this rare entity in Indian literature.

Adult↗
PubMed1990

Cloning of the p50 DNA binding subunit of NF-kappa B: homology to rel and dorsal.

The DNA binding subunit of the transcription factor NF-kappa B, p50, has been cloned. p50 appears to be synthesized as a larger protein that is then processed to its functional size. Sequence analysis reveals remarkable homology for over 300 amino acids at the amino-terminal end to the oncogene v-rel, its cellular homolog c-rel, and the Drosophila maternal effect gene dorsal. This establishes NF-kappa B as a member of the rel family of proteins, all of which display nuclear-cytosolic translocation. Protein sequence from the p65 polypeptide has established that it is not encoded in the same mRNA as p50. However, p65 appears homologous to c-rel, suggesting that c-rel may form heterodimers with p50 and rel may include a homodimerization motif.

Amino Acid Sequence↗
PubMed1990

Activation of myelin-associated cholesteryl ester hydrolase in developing rat brain.

Short-term regulation of rat brain cholesteryl ester hydrolase (CEH) by protein kinases is described. CEH was activated 280-340% in the presence of Mg2(+)-ATP and this inhibition was partially abolished by rabbit skeletal muscle protein kinase inhibitor or chlorpromazine, a phospholipid interacting drug, suggesting the involvement of cAMP-dependent protein kinase and protein kinase C, respectively. However, the involvement of other kinases cannot be ruled out. In developing rat brain, CEH activity per unit brain weight closely correlated with myelination. During the premyelination period (5 days postnatal), significantly higher activation (P less than 0.001) of CEH was observed by cAMP-dependent protein kinase or protein kinase C, when compared to activation observed during the period of active myelination (20 days postnatal). These results indicate that CEH in rat brain is tightly regulated and closely related to myelination.

Adenosine Triphosphate↗
PubMed1990

Activation in vitro of NF-kappa B by phosphorylation of its inhibitor I kappa B.

Nuclear factor kappa B (NF-kappa B), which was first detected by its binding to the kappa B site in the immunoglobulin kappa-gene enhancer, is important for the regulated expression of the kappa-gene and is partly responsible for the induction in appropriate cells of interleukin-2 (IL-2), IL-2 alpha receptor, beta-interferon and serum amyloid A protein. NF-kappa B is present as a nuclear DNA-binding protein in B lymphocytes and mature macrophages, but is found in the cytoplasm of many cells in a form unable to bind to DNA. The cytoplasmic form is bound to an inhibitor protein, I kappa B, from which it can be released in vitro by deoxycholate and other agents. Activation of cells by various agents, notably the phorbol esters that stimulate protein kinase C (PKC), leads to dissociation in vivo of the NF-kappa B/I kappa B complex and migration of NF-kappa B to the nucleus. Therefore, it acts as a second messenger system, transducing activation signals from the cytoplasm to the nucleus. To elucidate the mechanism of signal transfer, we have used an in vitro system in which addition of purified protein kinases to a partially purified NF-kappa B/I kappa B complex leads to the activation of the DNA-binding activity of NF-kappa B. Using gel retardation assays we found that PKC, cyclic AMP-dependent protein kinase (PKA) and a haem-regulated eIF-2 kinase (HRI) could activate NF-kappa B in vitro, whereas casein kinase II was ineffective. To determine the target for the protein kinases we purified and characterized both NF-kappa B and I kappa B and found that I kappa B is phosphorylated and inactivated in the presence of PKC and HRI but not PKA.

Adenosine Triphosphate↗