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Biomedical subjects

N Marwaha

Publications and source records attributed to N Marwaha.

At least 19 recordsLinked to original sources
PubMed2005

Change in tissue thromboplastin content of brain following trauma.

BACKGROUND: Tissue thromboplastin (TTP) is an integral membrane protein contributing to coagulopathy after trauma of brain, which is a rich source of TTP. AIMS: A study was undertaken to establish the TTP content of various areas of normal brain and estimate the changes in TTP activity of brain in response to varying degrees of trauma. MATERIALS AND METHODS: Samples from different areas of brain of ten cadavers were used as controls and they were compared with contused brain tissue obtained after surgery in 25 head injury (HI) patients of varying severity. RESULTS: In the study group, the TTP activity of the frontal, parietal, and temporal lobes after HI was significantly raised in contrast to that of the control group. The TTP activity was also significantly higher in the severe HI patients than those having moderate HI. The mode of injury and the time lapse after HI had no significant bearing on the TTP activity. Subjects above 40 years of age demonstrated a higher mean TTP activity after HI, though it was not statistically significant. CONCLUSION: The study provides quantitative data on TTP activity of normal brain and highlights the role of TTP in coagulopathy following HI through its increased activity after HI, more so in the severe HI group.

Adolescent↗
PubMed2001

Vitamin K deficiency in diarrhoea.

The study was undertaken to determine the frequency of occurrence of vitamin K deficiency in infants with diarrhoeal illness. Infants were categorized into four groups as follows: A(acute diarrhoea), B(protracted diarrhoea) C(intractable diarrhoea) and D(healthy controls). Screening coagulation tests, PT and PTTK along with estimation of functional activity and total antigenic levels of prothrombin were performed. The ratio of functional to total prothrombin was calculated. PT was prolonged in 30% (24/75) of all infants with diarrhoea as compared to controls where the abnormality was observed in 11.1% infants (2/18). The ratio of functional to total prothrombin was significantly lower in infants with diarrhoea, the mean +/- SD values being 0.65 +/- 0.41 vs 1.1 +/- 0.26. This difference was statistically highly significant (p < 0.001). Low ratio was observed in 57.3% (43/75) infants with diarrhoea. Thus functional to total prothrombin ratio identified approximately twice as many diarrhoeal infants with vitamin K deficiency as compared to PT alone. There was no significant correlation with breast feeding as the only mode of diet, or the prior administration of antibiotics in infants with diarrhoea. The inherent malabsorptive state in diarrhoea may be a major contributory factor.

Diarrhea, Infantile↗
PubMed2000

Alternative splicing of Drosophila calcium/calmodulin-dependent protein kinase II regulates substrate specificity and activation.

Drosophila calcium/calmodulin-dependent protein kinase II is alternatively spliced to generate multiple isoforms that vary only in a region between the calmodulin-binding domain and the association domain. This variation has been shown to modulate activation of the enzyme by calmodulin. In this study we examine the ability of seven of the Drosophila isoforms to phosphorylate purified protein substrates and to be inhibited by a substrate analog, and the response of six of the isoforms to a mutant form of calmodulin (V91G) that was isolated in a genetic screen. Significant variation in Kms for Eag, a potassium channel, and Adf-1, a transcription factor, were found. In the case of the a peptide inhibitor, AC3I, there were significant variations in Ki between isoforms. Kact for V91G calmodulin was increased for all of the isoforms. In addition, one isoform, RI, exhibited a lower Vmax when assayed with this mutant CaM. These results indicate that the variable domain of calcium/calmodulin-dependent protein kinase II is capable of altering the substrate specificity of the catalytic domain and the activation response to calmodulin.

Alternative Splicing↗
PubMed1999

Coagulation abnormalities in idiopathic portal venous thrombosis.

BACKGROUND: Portal vein thrombosis, usually idiopathic, is the cause of portal hypertension in 46% of Indian patients, who present with a variceal bleed. The presence of lupus anticoagulant (LA) and antithrombin III deficiency have been reported to be associated with an increased tendency to venous thrombosis. METHODS AND RESULTS: We studied 30 patients with portal venous thrombosis diagnosed by ultrasound. Two patients were positive for a lupus anticoagulant and both had very prolonged partial thromboplastin time with kaolin. None of the patients had antithrombin III deficiency.

Adolescent↗
PubMed1998

Disseminated intravascular coagulation: pathophysiology and principles of management.

DIC is a thrombohemorrhagic syndrome which occurs in association with well-defined clinical disorders such as septicemia, acute leukemia, snake envenomation, hypoxic states, etc. These disease conditions trigger the coagulation cascade in vivo resulting in formation of microthrombi, activation of fibrinolysis and a bleeding tendency. The important and most frequently observed laboratory abberrations include reduced platelet counts, low levels of fibrinogen, factors V and XIII with increased FDP's. Therapy primarily consists of recognizing the cause of DIC, removing the triggering process and administering anticoagulant therapy in specific situations. Component replacement is required if patients continue to bleed inspite of instituting the above mentioned measures. Rarely, drugs which inhibit fibrinolysis may be indicated. Early recognition and prompt institution of appropriate remedial measures coupled with adequate laboratory monitoring help in reducing morbidity and mortality due to DIC.

Anticoagulants↗
PubMed1997

Histological and clinical evolution patterns of chronic myelocytic leukemia.

Trephine biopsies of 101 chronic myelocytic leukaemia (CML) patients were analysed to study the relationship between initial and subsequent histological features vis-a-vis clinical behaviour of the disease. The patients with blast crisis at presentation were excluded. At diagnosis 62 (61.4%) patients revealed granulocytic-megakaryocytic (gran-meg) proliferation whereas granulocytic (gran) proliferation was found in 39 (38.6%) patients. Gran pattern at diagnosis was associated with shorter survival and early evolution into blast crisis (36.8%) in 12 months, although the difference in the total incidence of blast crisis between the two histological groups was not statistically significant. Myelofibrosis was detected in more number of cases on follow up (89.1%) as compared to the initial biopsies (80.2%). However myelofibrosis did not correlate with initial cellular composition, overall survival or the phase of CML (P > 0.05). Transition from one histological type to another was observed in 15 out of 60 (25%) cases while remaining in the chronic phase.

Biopsy, Needle↗
PubMed1995

Hyperaggregation of platelets in intestinal tuberculosis: role of platelets in chronic inflammation.

Eighty-eight percent (38/43) patients of intestinal tuberculosis showed significant hyperaggregation of platelets (P < 0.001). Serum and plasma from 15 patients when incubated with normal platelets caused hyperaggregation. Gel filtered platelets from 2 patients suspended in normal plasma showed hyperaggregation of platelets with arachidonic acid. Tubercular protein had no effect on platelet aggregation. A role of hyperactive platelets in chronic inflammatory response is discussed.

Adolescent↗
PubMed1995

Effect of oral water soluble vitamin K on PIVKA-II levels in newborns.

Intramuscular administration of vitamin K for prophylaxis against hemorrhagic disease of the newborn has the disadvantage of increased cost, pain, anxiety to parents and risk of transmission of infection. Oral route is a better alternative. Oral absorption of vitamin K has been shown to be equally good using special oral preparations. However, this preparation is not available in India. A prospective study was carried out on 51 full term, healthy breastfed newborns to evaluate if the injectable water soluble preparation of vitamin K (menadione sodium bisulphite) could be as effective. Fourteen babies received 1 mg vitamin K intramuscularly, 24 received 2 mg vitamin K orally while 13 controls did not receive vitamin K at birth. PIVKA-II levels were measured in cord blood and at 72-78 hours of age in all babies as a marker of vitamin K deficiency. The overall PIVKA-II prevalence in cord blood was 64.7%. At 72-78 hours, PIVKA-II was present in 50% of babies in IM group, 58.3% of babies in oral group and in 76.9% of babies in 'no vitamin K' group (p > 0.05). The PIVKA-II levels decreased or did not change at 72-78 hours in 91.6% of babies in oral group versus 92.8% of babies in IM group (p > 0.05). On the other hand, PIVKA-II levels increased in 30.7% of babies who did not receive vitamin K as against in 7.8% of babies receiving vitamin K in either form (p < 0.05). Hence, vitamin K prophylaxis is required for all newborns at birth and injectable vitamin K (menadione sodium bisulphite) given orally to term healthy babies is effective in preventing vitamin K deficiency state.

Administration, Oral↗
PubMed1995

Aplastic anaemia versus hypocellular myelodysplastic syndrome.

It is important to differentiate non-dyplastic aplastic anaemia from hypocellular myelodysplastic syndrome (MDS). Four patients presenting with hypocellular bone marrow and different evolution patterns are being described. Certain morphological features and variable hypocellularity were found to be useful indices for this purpose.

Adolescent↗