Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

1,284 records · Page 72Linked to original sources

PubMedDate not supplied

Effects of some ruthenium chelates on MCa mammary carcinoma and on TLX5 lymphoma in mice.

A group of four Ruthenium chelates of the mixed hard/soft N-S donor ligands 2-formylpyridine (4-H/4-phenyl)thiosemicarbazone has been studied in the experimental models of MCa mammary carcinoma and TLX5 lymphoma in the CBA mouse. Although all the four tested complexes, bis-[2-formylpyridine(4- phenyl)thiosemicarbazone]ruthenium(II)chloride]Ru(L1)(L1H)Cl, 1], [2-formylpyridine(4-phenyl)thiosemicarbazone]ruthenium(II)-mu- trichloro chloro(imidazole)ruthenium(III)monomethanolate [Ru2(L1)(imz)Cl4.CH3OH, 9]. [2-formylpyridine(4-phenyl)thiosemicarbazone]dichloroimidazoler uthenium(II) [Ru(L1H)(imz)Cl2,10] and bis[2- formylpyridinethiosemicarbazone]ruthenium(II) perchlorate, dihydrate [Ru(L)(LH)ClO4.2H2O, 16], reduced the formation of lung metastases at the same extent only compound 1 caused parallel inhibition of the growth of the primary tumor. The chemical nature of the tested compounds seems to determine the nature of the antitumor effects and the bis-chelates are found to be endowed with greater cytotoxic properties towards primary tumor than the monochelates. This opens up a very interesting point, whether it is the presence of two chelate rings around the Ruthenium(II)/(III) acceptor centre or the increase in the number of the soft (S) donor centers that generates greater cytotoxic properties in the corresponding ruthenium complexes. As far as the reduction of the metastasis formation is concerned, it appears that among the four Ruthenium chelates tested, it is possible to identify structures capable of controlling the spread of tumor to the lungs in the absence of significant cytotoxicity for tumor cells. This finding appears of importance in that it indicates the possibility of a specific mechanism of interaction with cells of the metastatic tumor. In this context it appears necessary to investigate other congeners of this "family" with more sulfur donor sites and particularly those with better water solubility.

Animals↗

PubMedDate not supplied

Intravenous thrombolytic therapy in unstable angina.

One hundred consecutive age and sex-matched patients of 3 different subsets of unstable angina (recent onset angina -65, crescendo angina -20, post-infarct angina-15) were randomized 1:1 after coronary angiography to receive I.V., either 1.5 x 10(6) units of streptokinase (SK) in 200 ml of normal saline or 200 ml of normal saline alone (control) in 1 hour. Repeat angiography was done in those patients having intra-coronary thrombi (37.3%) during the initial angiography. Both groups received optimal doses of heparin followed by warfarin, aspirin and other standard drugs and were followed up for 6 months. Anginal pain subsided significantly in the SK group-41 (82%) vs 25 (50%) (P < 0.005), especially in patients with recent onset angina (92.5% vs 60%, P < 0.005). Incidence of acute myocardial infarction (AMI) was much less in the SKgp (4(8%) vs 17 (34%) (p < 0.05). Four cases of fatal MI and four cases of sudden cardiac death (SCD) occurred in the control group against none in the SKgp. Requirements of mechanical revascularization was significantly less (P < 0.05) in the SK gp. Angiographic evidence of partial or complete clot lysis was noted in 90% of SK gp. vs 4.8% of control (P < 0.01). Echocardiographically assessed LV function improved significantly with SK-therapy in recent onset (P < 0.05) and crescendo angina (P < 0.001) subsets--however, the improvements in post infarct angina subset were not statistically significant. The beneficial outcome with SK therapy was observed in patients irrespective of angiographic evidence of thrombi.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMedDate not supplied

Induction of premature mitosis in cells blocked in S-phase: possibilities of its use in cancer therapy.

Oncogenesis leads to weak regulations of many cell cycle checkpoints. This could be useful for cancer therapy. To test this assumption, five human malignant cell lines were used to induce premature mitosis by overriding the S-phase control, which ultimately leads to cell death. Two cell lines showed a significantly high frequency of premature mitotic cells induced by okadaic acid; whereas the others did not. One cell line, although having a high cyclin B level in cells blocked in S-phase, failed to show premature mitosis. The cyclin B level in cells blocked in S-phase alone could not explain the differential behavior of the cell lines. It was observed that in addition, the activation of cdc25 in these cells could also play an important role in the induction of premature mitosis in such cells.

Cell Adhesion↗

PubMedDate not supplied

Cloning and expression of SAT-3 involved in SA-Le(x) biosynthesis: inhibition studies with polyclonal antibody against GST-SAT-3 fusion protein.

The SAT-3 activity (CMP-NeuAc:Gal beta 1-4GlcNAc beta 1-3 Gal beta 1-4Glc-ceramide alpha 2-3 sialytransferase) involved in the biosynthesis of sialy Le(x) has been characterized in human colon carcinoma cells and embryonic chicken brains. Using RT-PCR-based strategy, we have isolated partial cDNA clones of SAT-3 from ECB and Colo-205 mRNAs. Suitable primers from sialylmotif and N-terminal sequence of human placenta SAT-3 (HP-SAT-3) were used. The 800 bp cDNA fragment encoding a region (90%) of alpha 2-3 sialyltransferase (SAT-3) catalytic domain from ECB has been expressed as a glutathione S-transferase (GST) soluble fusion protein (62 kDa) in E. coli and purified over glutathione-agarose affinity matrix. Polyclonal antibody has been produced against affinity-purified catalytic domain of SAT-3 (GST-SAT-3 fusion protein). A concentration-dependent polydonal antibody binding to native SAT-3 has also been demonstrated by measuring the residual SAT-3 activity in the enzyme fractions from Colo-205. The marked inhibition (> 80%) of SAT-3 activity and relatively less inhibition (< 20%) of SAT-4 activity (CMP-NeuAc:GgOse4Cer alpha 2-3sialyl transferase) suggests strongly the existence of two different gene products (SAT-3 and SAT-4) in human colon carcinoma Colo-205 cells and in embryonic chicken brains (ECB).

Animals↗

PubMedDate not supplied

Epidemiology of group-A streptococcal infection amongst children of different ethnic groups in Darjeeling.

The carrier rate of Group A Streptococcus (GAS) was studied amongst 932 children from 1+ upto 12 years of age in three major racial groups in the foothills of the Darjeeling district of West Bengal. It was altogether 13 per cent and was found to be evenly distributed in the three ethnic groups as Gurkhas: 11 per cent, Rajbanshis: 15 per cent and Cosmopolitans: 13 per cent, but the incidence of Rheumatic fever and/or Rheumatic heart diseases were unnoticed among the Gurkha children who also had significant low ASO titres.

Carrier State↗

PubMedDate not supplied

Modeling and evaluation of continuity of care in a staff model HMO.

The concept of continuity in medicine refers to the delivery of care in an uninterrupted and coordinated manner and in accordance with the patient's medical needs. Many diseases and symptoms require serial observation and treatment over long periods and are interwoven with the patient's personal and social circumstances. We believe that the depth of a primary care provider's understanding of a patient is directly proportional to the total length of interaction between the patient and provider. We have reviewed the published studies in this area, and modeled continuity of care in an HMO clinic. The patients' ages, their visiting patterns, and the length of their interactions with their doctors were synthesized stochastically. We now propose a new way of defining continuity of care, the Fundamental Continuity of Care Index (FCCI), and recommend its use. Hospitals, insurance companies, and governments should be aware of the benefits of continuity and all physicians should commit themselves to longitudinal care for their patients.

Adolescent↗