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Biomedical subjects

K Ghosh

Publications and source records attributed to K Ghosh.

At least 235 records · Page 13Linked to original sources
PubMed1991

Oligodeoxynucleotide analogs as informational drugs to regulate translation.

Of the chemically modified backbone analogs of oligodeoxynucleotides that have been developed for antisense applications, the phosphorothioate (PS) analog has perhaps the best properties. Nevertheless, it also has certain disadvantages, notably reduced hybridization and increased non-selective inhibition of translation, compared to the natural phosphodiester (PO) compounds. We have therefore synthesized and characterized a series of co-polymers, with the same antisense beta-globin sequence, but with different repeated sequences of PO and PS and tested them for their comparative properties. The results indicate that a PO-PS co-polymer is the best backbone modification for an antisense compound.

Animals↗
PubMed1991

Smokeless tobacco and premalignant and malignant lesions of the oral cavity.

The paper compares the prevalence of oral carcinoma and dysplasia in smokeless tobacco users and non users. A total of 3205 subjects were studied. Of the smokeless tobacco users, 1.96 percent had oral carcinoma compared with 0.36 percent of non-users. The prevalence of oral dysplasia in the users' group was 14.4 percent as compared with 6.85 percent in the group of non-users.

Developing Countries↗
PubMed1990

Shortened cytoplasmic domain affects intracellular transport but not nuclear localization of a viral glycoprotein.

Herpes simplex virus (HSV) buds from the inner nuclear membrane of the infected cells. The glycoprotein gB-1 of HSV contains a stretch of 69 hydrophobic amino acids near the COOH terminus and a 109-amino acid cytoplasmic domain. By oligonucleotide-directed mutagenesis, five gB-1 mutants were constructed which either lack a cytoplasmic tail or contained 3, 6, 22, or 43 amino acids in the cytoplasmic tail. When expressed in COS cells all of the mutant glycoproteins were synthesized but the rate of intracellular transport and the appearance at the cell surface of the mutant gB-1 protein lacking the cytoplasmic tail or containing 3 and 6 amino acids in the cytoplasmic domain was drastically reduced. The wild-type gB-1 as well as all of the mutants in the cytoplasmic tail were, however, located on the nuclear envelope. These results suggest that the cytoplasmic domain of the glycoprotein gB may play a role in intracellular transport but not in the nuclear localization.

Biological Transport↗
PubMed1990

Hemostatic alterations in non-cirrhotic portal fibrosis, extrahepatic portal venous obstruction and Budd-Chiari syndrome.

We studied the coagulation function in ten patients each with non-cirrhotic portal fibrosis (NCPF), extrahepatic portal venous obstruction (EHPO) and Budd-Chiari syndrome (BCS), conditions where venous thrombosis in the hepatic vasculature is a common denominator. Prothrombin time, partial thromboplastin time with kaolin (PTTK) and thrombin time were normal in patients with NCPF and EHPO. However, in BCS the PTTK was prolonged, with a mean test/control ratio of 1.68 +/- 0.11. Fibrin degradation products were absent in all patients. Platelet aggregation tests showed hypoaggregability in all patients with NCPF. They were normal in patients with EHPO. However, two of ten BCS patients showed hyperaggregability, coinciding with a recent onset of illness in one patient. In conclusion, coagulation abnormalities appear unlikely to be the cause of thrombosis in patients with NCPF and EHPO. Further studies are required to substantiate the findings of hyperaggregability of platelets in BCS.

Adolescent↗
PubMed1990

Uterine cervical dysplasia with reference to the betel quid chewing habit.

Systemic effects of betel quid are poorly documented compared to its local effects on the mucosa of the oral cavity and pharynx. In the present study dysplastic activity of the betel quid on exfoliated uterine cervical cells was studied and compared with women addicted to other habits or nothing. That the mutagenic changes at cellular level are associated with prolonged use of betel quid is suggested.

Adolescent↗
PubMed1989

Asymptomatic salpingitis in intrauterine contraceptive device users.

Serial histological sections of the fallopian tubes of 50 asymptomatic subjects undergoing voluntary tubal ligation were evaluated for morphological evidence of inflammation. Twenty-five subjects had history of IUD use (the study group) and the rest 25 had never used a device (the control group). Evidence of inflammation was found in 11 out of 25 subjects in the IUD users compared to only 2 out of 25 subjects in the non-users (p less than 0.001). The relative risk was 5.5 times. Both acute and chronic inflammation of the oviducts were observed more often in the IUD users, though clinically and at surgery there was no apparent evidence of pelvic inflammatory disease.

Adult↗
PubMed1989

Pancytopenia in nutritional megaloblastic anaemia. A study from north-west India.

We have analysed 139 consecutive cases (71 males and 68 females) of nutritional megaloblastic anaemia over a period of four and a half years. The majority of these patients belonged to the low socio-economic class and many of them were strict vegetarians. Sixty one percent were in the second and third decades of life. At the time of presentation, 46% had mild hepatomegaly, 42% fever, 34% mild splenomegaly and 20% bleeding manifestations. Of 102 cases in whom the biochemical parameters were available, vitamin B12 deficiency was detected in 76%, folate deficiency in 6.8%, combined B12 and folate deficiency in 8.8%; the remaining 7.8% had normal vitamin levels at presentation. All 139 patients had severe anaemia, 80.5% had thrombocytopenia and 43.8% had neutropenia as well as thrombocytopenia. It appears that during progression (in terms of duration) of megaloblastosis, anaemia is followed by thrombocytopenia and then neutropenia. Infection and bleeding in these patients may be aggravated by impaired functions of neutrophils and platelets, respectively.

Adolescent↗
PubMed1989

Serum vitamin B12 levels in an Indian population: an evaluation of three assay methods.

Serum vitamin B12 levels were measured in 300 Indian subjects, comprising 165 haematologically normal volunteers, 78 cases of nutritional megaloblastic anaemia and 57 patients with myeloproliferative disorders. Each sample was assayed by three different techniques: i) a microbiological assay using Euglena gracilis as the test organism; ii) radioisotope dilution assay, using pure intrinsic factor as the B12 binder and haemoglobin-coated charcoal for separation of bound from free vitamin B12; iii) radioisotope dilution assay using intrinsic factor as the vitamin B12 binder and DEAE cellulose for separation of bound from free vitamin B12. Results by the three methods correlated closely at normal and high levels of serum B12: at low levels microbiological assay and radio-assay using haemoglobin-coated charcoal correlated well but DEAE cellulose failed to detect 16 of 68 patients with vitamin B12 deficiency. The radioisotope dilution assay tended to yield higher values of serum vitamin B12 than did the microbiological assay. In none of the healthy volunteers was a clearly low value found by any of the techniques, but 20 of them had low serum B12 levels. Radioisotope dilution assay using haemoglobin-coated charcoal is recommended as an accurate assay procedure for developing countries like India, where ready-made kits are not easily available and vitamin B12 deficiency states are common.

Anemia, Megaloblastic↗
PubMed1988

Functional and ultrastructural changes of platelets in malarial infection.

This paper describes changes in the circulating platelets of 25 patients with acute malaria within 2 to 6 days of onset of illness. Thrombocytopenia was observed in 10 out of 15 patients with Plasmodium falciparum infection, and in 4 out of 9 patients with P. vivax infection. One patient with a mixed infection of both species had a disseminated intravascular coagulation. Platelet antibody was detected in the sera of 8 out of 11 cases by the complement lysis inhibition technique and indirect immunofluorescence. The mean platelet antibody concentrations in the sera of 11 patients and 53 control subjects were 122.70 +/- 80.25 ng/10(7) platelets and 36.69 +/- 18.72 ng/10(7) platelets, respectively. An inverse relationship between the platelet count and platelet antibody levels in serum supported the view that thrombocytopenia in malaria may be partly immune-mediated. Platelet aggregation responses to agonists such as ADP, adrenaline, collagen and ristocetin revealed hyperactivity. Ultrastructural study of unstimulated platelets from patients revealed several changes such as centralization of dense granules, glycogen depletion, and formation of pseudopods and microaggregates, indicating in vivo activation of the platelets, which may also lead to thrombocytopenia.

Adolescent↗
PubMed1988

Dysplastic eosinophils in three patients with acute promyelocytic leukaemia.

Three cases of acute promyelocytic leukaemia (M3) with dysplastic eosinophils are reported. Promyelocytes from these cases showed classical features of hypergranular acute promyelocytic leukaemia. All the cases had minimal organomegaly and disturbances of coagulation were minimal. All the cases were associated with dysplastic eosinophils in the marrow but very few of these eosinophils were found in peripheral smear. One of the three patients presented with a mass in the vertebral column, a feature not uncommonly seen in a variant form of AML-M2 with eosinophilia. Dysplastic eosinophils appear to arise from leukaemic clone itself. These three cases probably represent hitherto undescribed morphological variant of acute promyelocytic leukaemia where leukaemic cells show limited differentiation capability to dysplastic eosinophils.

Adult↗