PubMed Health⌕ Search

Biomedical subjects

D Basu

Publications and source records attributed to D Basu.

At least 55 records · Page 3Linked to original sources
PubMed1998

Rapid diagnosis of Indian visceral leishmaniasis using achatininH, a 9-O-acetylated sialic acid binding lectin.

We have developed a rapid, accurate, and inexpensive hemagglutination assay (HA) for diagnosis of Indian visceral leishmaniasis (VL) using achatininH, a 9-O-acetylated sialic acid binding lectin. The assay is based on the selective binding of achatininH to 9-O-acetylated derivatives of sialic acid (9-O-AcSA), which appears exclusively on the erythrocytes of patients with VL. Blood samples from 35 patients with demonstrable splenic or bone marrow amastigotes were assayed by HA and compared with an ELISA. All cases were correctly diagnosed by HA, and were in concordance with the ELISA. The increase in 9-O-AcSA was corroborated by direct fluorimetric estimation of sialic acid and its 9-O-acetylated derivative. Therefore, 9-O-acetylated derivatives of sialic acid, absent in normal erythrocytes, serve as an important biomarker, and indirectly reflect the presence of the parasite. Accordingly, this assay can be used for detection of active kala-azar cases and merits clinical consideration.

Biomarkers↗
PubMed1997

Transgenic elite indica rice plants expressing CryIAc delta-endotoxin of Bacillus thuringiensis are resistant against yellow stem borer (Scirpophaga incertulas).

Generation of insect-resistant, transgenic crop plants by expression of the insecticidal crystal protein (ICP) gene of Bacillus thuringiensis (Bt) is a standard crop improvement approach. In such cases, adequate expression of the most appropriate ICP against the target insect pest of the crop species is desirable. It is also considered advantageous to generate Bt-transgenics with multiple toxin systems to control rapid development of pest resistance to the ICP. Larvae of yellow stem borer (YSB), Scirpophaga incertulas, a major lepidopteran insect pest of rice, cause massive losses of rice yield. Studies on insect feeding and on the binding properties of ICP to brush border membrane receptors in the midgut of YSB larvae revealed that cryIAb and cryIAc are two individually suitable candidate genes for developing YSB-resistant rice. Programs were undertaken to develop Bt-transgenic rice with these ICP genes independently in a single cultivar. A cryIAc gene was reconstructed and placed under control of the maize ubiquitin 1 promoter, along with the first intron of the maize ubiquitin 1 gene, and the nos terminator. The gene construct was delivered to embryogenic calli of IR64, an elite indica rice cultivar, using the particle bombardment method. Six highly expressive independent transgenic ICP lines were identified. Molecular analyses and insect-feeding assays of two such lines revealed that the transferred synthetic cryIAc gene was expressed stably in the T2 generation of these lines and that the transgenic rice plants were highly toxic to YSB larvae and lessened the damage caused by their feeding.

Animals↗
PubMed1997

Characterization of a beta-lactamase from Mycobacterium smegmatis SN2.

Beta-lactamases have been reported to be largely responsible for beta-lactam resistance in Mycobacteria. We report the characterization of a cell-associated beta-lactamase from Mycobacterium smegmatis. The enzyme hydrolyzed the "beta-lactamase-stable" oximinocephalosporins. Nitrocefin was the best substrate. 6-Beta-iodopenicillanate, clavulanate and sulbactam were effective inhibitors, whereas the Ki value for aztreonam was high. From its substrate and inhibitor profile, the enzyme appeared to be a cephalosporinase of group 2e.

Amino Acid Sequence↗
PubMed1997

Characterization of a porin from Mycobacterium smegmatis.

A pore-forming protein with an Mr of 40,000 has been extracted from the cell wall of Mycobacterium smegmatis with buffer containing the detergent Zwittergent 3-12 and 0.5 M NaCl and purified on an anion-exchange column. Although the pore diameter was large (2 nm), the specific activity was much lower than those of nonspecific porin channels of enteric bacteria. The channel allowed the permeation of small hydrophilic molecules such as sugars and amino acids. Its N-terminal sequence did not show any similarity to those of other porins sequenced so far.

Amino Acid Sequence↗
PubMed1997

Abuse of codeine-containing cough syrups: a report from India.

AIM: To study the socio-demographic and clinical profile of patients seeking treatment for abuse of codeine-containing cough syrups (CCS). DESIGN: Observational; case series. SETTING: An addiction clinic in North India. PARTICIPANTS: Forty-six consecutive treatment-seeking patients of DSM-III-R-diagnosed dependence on CCS, from January 1994 to June 1995. MEASUREMENTS: Semi-structured interview schedule for patients and their family covering socio-demographic and clinical variables. FINDINGS: All patients were male. Many were young (mean age 27 years), with completed school education (85%) and from urban backgrounds (80%). The mean age of starting CCS use was 23 years. Initiated commonly through friends (89%) and often for curiosity (63%), 89% of the patients progressed to daily use of CCS in less than 6 months (54% in less than a month), and in quantities much higher than prescribed limits. Opioid-like withdrawal was reported by 92%. Concurrent use of other substances, psychiatric co-morbidity and HIV-related risk behaviour were present in 72%, 24% and 45%, respectively. Most of the patients reported a 'stimulant' effect of CCS ('alert', 96%; 'more active', 94%). CONCLUSIONS: The combination of an opioid and a sympathomimetic agent in the CCS may cause a special, distinct euphoretic effect. This effect, along with the low price, easy availability and 'pure' preparation of CCS, may be responsible for the rapidly rising popularity of the CCS as drugs of abuse in India.

Adolescent↗
PubMed1996

Biochemical characterization of the 49 kDa penicillin-binding protein of Mycobacterium smegmatis.

The 49 kDa penicillin-binding protein (PBP) of Mycobacterium smegmatis catalyses the hydrolysis of the peptide or S-ester bond of carbonyl donors R1-CONH-CHR2-COX-CHR2-COO- (where X is NH or S). In the presence of a suitable amino acceptor, the reaction partitions between the transpeptidation and hydrolysis pathways, with the amino acceptor, behaving as a simple alternative nucleophile at the level of the acyl-enzyme. By virtue of its N-terminal sequence similarity, the 49 kDa PBP represents one of the class of monofunctional low-molecular-mass PBPs. An immunologically related protein of M(r) 52,000 is present in M. tuberculosis. The 49 kDa PBP is sensitive towards amoxycillin, imipenem, flomoxef and cefoxitin.

Amino Acid Sequence↗
PubMed1994

Cutaneous T-cell lymphoma diagnosed by fine-needle aspiration: a case report with clinical, cytological, and immunophenotypic features.

A case study of cutaneous T-cell lymphoma in a 40-yr-old Indian male is presented. Prominent clinical features consisted of large skin tumours, lymphadenopathy, and a rapidly progressive course of development. Aspiration smears from tumours, lymph nodes, and bone marrow showed pleomorphic Sezary cells and lymphoid blasts. The neoplastic cells stained positively with anti-HLA DR, CD1, and CD2 antibodies and showed lack of T-cell subset antigens CD4 and CD8. Numerous proliferating cells were identified with 56% of bone marrow cells and 57% of cells in the dermis staining positively with Ki-67 and PC10 antibodies, respectively. This case is reported in view of its uncommon features.

Adult↗
PubMed1994

Psychosexual dysfunction in Indian male patients: revisited after seven years.

Short-term (1 year) outcome of 66 male patients with psychosexual dysfunction was studied in the context of patients' sociodemographic and clinical characteristics. A combination of erectile dysfunction and premature ejaculation was the most common diagnosis. Long-term (7 years) outcome of this cohort was evaluated in relation to short-term outcome. Improvement in the short-term indicated favorable long-term outcome. Initial dropout was associated with chronic and continuous sexual dysfunctioning.

Adolescent↗
PubMed1994

Pseudoaneurysm in injecting drug abusers: cases from India.

Pseudoaneurysm, a known complication of arterial needle puncture, is also an uncommon complication of parenteral drug abuse. India is currently witnessing an upsurge of abuse of injectable drugs. Five cases of pseudoaneurysm developing as a complication of intra-arterial drug abuse are reported. The need for early recognition and proper timely intervention is highlighted.

Adult↗
PubMed1994

Micrometastasis in bone marrow in breast cancer.

Bone marrow trephine biopsy (BMB) was done in 57 consecutive cases of breast cancer in order to detect micrometastasis. In 46 cases, presenting for the first time, tumor cells were seen in the bone marrow in nine (19.5%) cases. Out of 11 cases who presented with recurrence, micrometastasis was detected in seven (63.6%). Bone marrow aspiration (BMA) could detect only two of these sixteen positive cases. Immuno peroxidase staining or Epithelial Membrane Antigen (EMA) helped picked up three cases which were negative on routine Hematoxylin and Eosin (H&E) stain. BMB is indicated in the evaluation of breast cancer at diagnosis and at relapse.

Adult↗
PubMed1993

Testicular cytology in azoospermia.

Two hundred-seventy-five azoospermic males were subjected to fine-needle aspiration (FNA) cytologic study of testis with the aim of determining the cause of azoospermia; 534 aspirates from these patients were classified as follows: normal spermatogenesis (162), hypospermatogenesis (mild, moderate, or severe, 226), absence of spermatogenesis (130), maturation arrest (36), Sertoli-cell-only syndrome (14), and Leydig-cell hyperplasia (3). The morphology of cells was excellent in the cytologic preparations and various spermatogenic cells and Sertoli cells were easily recognized. Leydig cells were uncommonly seen, except in cases of Leydig-cell hyperplasia. Degenerative changes, possibly due to obstruction, were seen in 104 cases. The procedure was well tolerated by the patients. We conclude that FNA cytology is a useful investigative modality in the evaluation of azoospermic males.

Biopsy, Needle↗
PubMed1993

Enzymatic amplification of mini-exon-derived RNA gene spacers of Leishmania donovani: primers and probes for DNA diagnosis.

The multicopy mini-exon-derived RNA (med RNA) locus of Leishmania donovani was enzymatically amplified by the polymerase chain reaction (PCR). The major 180 bp PCR product contained conserved med RNA gene sequences flanking the variable intergenic spacer from the med RNA gene tandem repeat. The oligonucleotide primers cross-reacted with other Leishmania species. In serial dilution experiments, positivity in the PCR assay was observed down to the genomic DNA equivalent of less than a single Leishmania cell. When the major PCR products from Indian L. donovani isolates were cloned and used as probes in dot hybridization analyses, they discriminated between L. donovani and L. amazonensis, L. major and L. infantum under high stringency conditions. DNA from spleen biopsies and blood samples of confirmed kala azar patients was positive, as were two skin biopsies from patients with post-kala azar dermal leishmaniasis (PKDL). These observations demonstrate that PCR amplification of med RNA intergenic spacers is sufficiently sensitive for clinical diagnosis of kala azar and PKDL, and furthermore, that cloned intergenic spacer probes may be useful for identification and classification of L. donovani.

Animals↗
PubMed1993

Detection of structural and trace metal changes in scalp hair of radiographers.

Human scalp hair samples were collected from 24 medical radiographers and from 24 nonradiographers (control group) of matching age groups belonging to both sexes. Changes in zinc, copper, and iron content, as well as structural morphology of hair, were studied by atomic absorption spectrometry and scanning electron microscopy, respectively. Such studies revealed increases in zinc, copper, and iron concentrations along with varied types of cuticular damage in the radiographers' hair compared to that of nonradiographers. Present observations indicate the possibility of radiation hazards for radiation workers.

Adult↗