Search PubMed⌕ Search

Biomedical subjects

N Marwaha

Publications and source records attributed to N Marwaha.

At least 37 records · Page 2Linked to original sources
PubMed1994

The molecular basis of beta thalassaemia in Punjabi and Maharashtran Indians includes a multilocus aetiology involving triplicated alpha-globin loci.

We have analysed 201 beta-thalassaemia (beta-thal) genes from natives of the Punjab (156) and Maharashtra states of India and found the causative mutation in 200 of them. The most common beta-globin gene mutations differed significantly between these two groups and between these groups and Indian immigrants in the U.S.A. and the U.K. In the Punjabi Indians the IVS-1, nt 1 (G-T) mutation accounted for nearly one-quarter of beta-thal genes, whereas it was 5% or less in the other groups. Likewise, the cap + 1 mutation was much more prevalent in the Punjabis, whereas the nonsense codon 15 allele had a higher frequency in the Maharashtrans of the Bombay region. The common IVS-1, nt5 allele had a frequency of 60% of beta-thal genes in the Maharastrans, 35% in North American immigrants, and only 23% in the Punjabis. Two-thirds of all beta-thal genes in Punjab were found in the merchant caste (Khatri-Arora), whereas the menial caste (Shudra) was highly represented among those with beta-thal genes in Maharashtra. Two novel beta-globin alleles were each found once; a frameshift codon 55 (+A) in Maharashtrans and a frameshift codons 47-48 (+ATCT) in Punjabis. Of three Punjabi patients with beta-thal intermedia in whom only a single severe beta-globin gene mutation was found, two had six alpha-globin genes (homozygosity for a triplicated alpha-globin locus) instead of the normal alpha-globin gene number of four. Thus, these two individuals had a multilocus aetiology of beta-thal and their parents have the unusual recurrence risk of 1 in 8 for conceiving a third with beta-thal intermedia. Since 15% of 126 alpha-globin clusters studies in Punjabis contained either single (10%) or triplicated (5%) alpha-globin genes, the alpha-globin gene number is a frequent modifier of the phenotype of beta-thal in this ethnic group.

Alleles↗
PubMed1994

Haemostatic derangement in patients with intracranial tumours.

Forty-five patients with brain tumours were studied for evidence of any haemostatic abnormalities in the preoperative and intraoperative period. An abnormality was found in 44 of the patients in the preoperative period and in all the patients during the operation. One patient developed acute disseminated intravascular coagulation. A change in the haemostatic abnormality from the preoperative to the intraoperative period was demonstrated in 9 of the patients. The histological nature of the tumour did not influence the haemostatic derangement. A shortened euglobulin lysis time, prolonged thrombin time, increased fibrin degradation products and abnormal fibrinogen levels were the common isolated abnormalities. When considered together, chronic disseminated intravascular coagulation (DIC) with or without fibrinolysis and fibrinolysis with or without DIC were the commonest abnormalities. Although some degree of haemostatic derangement is found in a high proportion of patients with brain tumours, clinically relevant abnormalities are rare.

Adolescent↗
PubMed1993

Relative efficacy of bone marrow trephine biopsy sections as compared to trephine imprints and aspiration smears in routine hematological practice.

The relative efficacy of trephine sections, trephine imprints and aspiration smears in yielding diagnostic and additional information was compared in 767 sets of bone marrow samples. Trephine sections were diagnostic in significantly more cases as compared to trephine imprints and aspiration smears (P < 0.001). Additional information was obtained in 326 trephine sections which was not available from trephine imprints and aspiration smears. Significantly more number of trephine sections provided diagnosis in case of dry tap/scanty material, for assessment of lymphoma-tumour infiltration, cellularity, Perl's reaction, megakaryocyte density and proliferating cell lines in myeloproliferative disorders. Fibrosis of bone marrow, pattern of bone marrow involvement and topographical alterations were appreciable only on trephine sections. The differential counts done on trephine imprints and aspiration smears correlated well and cytomorphological characterisation of immature cells (blasts and promyelocytes) could be done on these two preparations. Although trephine sections provide maximum information, all three preparations were found complementing each other and should be evaluated simultaneously for complete bone marrow interpretation.

Biopsy↗
PubMed1992

Routine hematological values in term newborns.

Routine hematological parameters were investigated in 240 term normal neonates, 40 neonates in the first week of life and 49 infants between 3 and 6 months of age. Term normal neonates were selected on the basis of well defined criteria. Cord blood Hb values of 16.2 +/- 1.5 g/dl compared well with some of the recent Indian studies and Caucasian figures. Cord blood hemoglobin was lower in the presence of low maternal hemoglobin and in newborns delivered by Cesarean section. A wide variation existed in the total and differential leucocyte counts, thus limiting the clinical utility of white cell counts in the newborn period. Platelet counts were within the adult normal range.

Blood Cell Count↗
PubMed1991

Fibrinolytic activity in human malignant tumors.

We have studied fibrinolytic activity of 12 cases of infiltrating duct carcinoma of breast (7 metastatic and 5 non-metastatic) and ten cases of adenocarcinoma of gastrointestinal tract (5 each of metastatic and nonmetastatic), and compared with some of their normal tissue counterparts. Both metastatic and non-metastatic tumors of breast and gastrointestinal tract had significantly higher levels of fibrinolytic activity as compared to normal tissues. Though mean fibrinolytic activity (expressed as ug/ml of urokinase activity) of metastatic tumors of breast and gut had higher values as compared to non-metastatic counterparts, however it did not reach statistical significance.

Adenocarcinoma↗
PubMed1991

A clinico-pathological study of six cases of hairy cell leukaemia.

Clinicopathological findings of six cases of Hairy cell leukaemia are presented. All the patients were males, the age ranged between 32-57 years. Complications of anaemia and neutropenia were common modes of presentation. Hepatomegaly and splenomegaly were present in all the cases whereas only 2 patients had lymphadenopathy. Severe pancytopenia was detected in 3 cases and circulating hairy cells were present in all the cases. Trephine biopsy done in all six patients was found to be diagnostic. Tartrate resistant acid phosphatase was detected in the hairy cells of 2 cases.

Adult↗
PubMed1991

Clinico-hematological characteristics in patients with kala azar. A study from north-west India.

Clinico-hematological features were analysed in 23 patients with kala azar. Fever and hepatosplenomegaly were the main presenting features. All patients were moderate to severely anemic (Hb 4.3-8.1 g/dl), 17 were leucopenic and 15 were thrombocytopenic. Bone marrow showed moderate to severe megaloblastosis in 11 cases, an increased number of plasma cells in 20 and megakaryocytic hyperplasia with abnormal morphology in 19 patients. Megakaryocyte numbers per smear were significantly increased (p = 0.01) in thrombocytopenic patients as compared to patients with normal platelet counts. Spleen size, Hb level, platelet count and number of plasma cells in the bone marrow were related to parasite load. In general the degree of parasitisation, spleen size and duration of illness correlated with some of the main hematological features. Thus splenic sequestration and ineffective hematopoiesis appear to be the main etiopathogenetic factors in the emergence of bone marrow changes and peripheral cytopenias.

Adolescent↗
PubMed1991

Assays for lupus anticoagulant: the sensitivity of different assays.

Fifty patients with systemic lupus erythematosus were studied for the presence of lupus anticoagulant using three different assays--kaolin clotting time, platelet neutralization test, and tissue thromboplastin inhibition test. Lupus anticoagulant could be detected in seven cases (14%) with the use of one test in cases with a partial prothrombin time with kaolin more than five seconds greater than normal. The detection rate rose to 20% (10 cases) when using all three tests, so a panel of three assays could identify lupus patients apparently at risk for thrombotic complications.

Blood Coagulation Factors↗
PubMed1990

Procoagulant activity of human tumours: existence of Xa and thrombin-like activities.

We have analysed 15 infiltrating duct carcinomas of the breast, 10 gastrointestinal adenocarcinomas, one each of the thyroid and larynx, and four mesenchymal tumours for the presence and the nature of procoagulant activity (PCA). The metastatic tumours had a significantly higher PCA (P = 0.01-0.001) as compared to the non-metastatic tumours in the respective groups, and almost 20-25 times the activity as compared to normal tissue (P = 0.001). Although the majority of the tumours had FVII-dependent tissue thromboplastin-like activity, some of the tumour homogenates revealed the presence of an FVII-independent PCA. Unlike the known alternate PCA, which acts via factor X activation, this PCA was factor X independent. It caused clot formation in FX-deficient plasma (six cases) and purified fibrinogen solution (four cases), indicating the presence of a Xa-like enzyme or a thrombin-like activity respectively.

Adenocarcinoma↗
PubMed1990

Danazol therapy in immune thrombocytopenic purpura.

Nine children with chronic refractory immune thrombocytopenic purpura and moderate to severe episodes of bleeding were treated with Danazol in an attempt to increase their platelet counts and improve clinical hemostasis. Only one patient experienced an excellent response while a good response was obtained in another. Cessation of bleeding episodes was observed in two other children with only marginal increases in platelet counts. Four of the nine patients failed to show any clinical or hematological improvement. The drug was well tolerated but its efficacy in childhood ITP needs further evaluation.

Child↗
PubMed1990

Pure red cell aplasia associated with essential thrombocythemia (a case report).

A rare case of erythroblastopenia associated with essential thrombocythemia (ET) is described. The patient had markedly elevated platelet count (5200 x 10(9)/1) and significant platelet dysfunction leading to extensive soft tissue and gastrointestinal hemorrhage. There was paucity of erythroid precursors in the bone marrow - a feature hitherto undescribed in ET. The thrombocytosis responded to well busulphan therapy but patient succumbed to fulminant infection consequent upon drug induced neutropenia.

Female↗