301
|
Murmu N, Ghosh P, Gomes A, Mitra S, Das M, Besra SE, Majumdar J, Bhattacharya S, Sur P, Vedasiromoni JR. Antineoplastic effect of new boron compounds against leukemic cell lines and cells from leukemic patients. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2002; 21:351-6. [PMID: 12385577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Three new boron compounds, dihydroxy (oxybiguanido) boron (iii) hydrochloride monohydrate (HB), guanidine biboric acid adduct (GB) and hydroxosalicyl hydroxomato boron (iii) (SHB) were studied to observe their antineoplastic effect, if any. Leukemic cells isolated from acute lymphatic leukaemia (ALL) patients and chronic myeloid leukaemia patients (CML) and myeloid leukemia cell lines (HL 60 and U-937) showed cell growth inhibition after treatment with the boron compounds. MTT assay showed that the growth of metabolically active cells was inhibited by treatment with these drugs. The molecular mechanism by which SHB induced apoptosis in immature blast cells was also investigated by ladder formation in gel electrophoresis.
Collapse
MESH Headings
- Acute Disease
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Boron Compounds/pharmacology
- Cell Division/drug effects
- Guanidines/pharmacology
- HL-60 Cells/drug effects
- HL-60 Cells/pathology
- Humans
- Leukemia, Lymphoid/drug therapy
- Leukemia, Lymphoid/metabolism
- Leukemia, Lymphoid/pathology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/drug therapy
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/metabolism
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/pathology
- Tetrazolium Salts
- Thiazoles
- Thymidine/metabolism
- U937 Cells/drug effects
- U937 Cells/pathology
Collapse
|
302
|
Sharma T, Galea A, Zachariah E, Das M, Taylor D, Ruprah M, Kumari V. Effects of 10 mg and 15 mg oral procyclidine on critical flicker fusion threshold and cardiac functioning in healthy human subjects. J Psychopharmacol 2002; 16:183-7. [PMID: 12095079 DOI: 10.1177/026988110201600210] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The critical flicker fusion threshold (CFFT) is thought to index alertness and cortical arousal. Sedative drugs reduce CFFT while psychostimulants increase it. Procyclidine is an anticholinergic that is used to control the extrapyramidal side-effects of antipsychotics in schizophrenia. This study examined the effects of clinically relevant doses of oral procyclidine administration on CFFT and heart rate in two separate experiments (Experiment 1, drug dose: 10 mg, n = 16; Experiment 2, drug dose: 15 mg, n = 12) involving healthy subjects using a double-blind, placebo-controlled, cross-over design. 10 mg procyclidine had no significant effect on CFFT, heart rate or self-ratings of mood, but the 15 mg dose significantly lowered CFFT at 1 h and 2 h after procyclidine administration, increased drowsiness ratings and produced a drop in heart rate. The effects observed in this study may have implications for treatment compliance of schizophrenic patients, choice of antipsychotics, prescribing to patients with heart disease and monitoring of cardiac function under treatment. Further investigations are required to quantify the effects of procyclidine on CFFT and cardiac function in patients with schizophrenia.
Collapse
|
303
|
Das M, Dempsey EC, Reeves JT, Stenmark KR. Selective expansion of fibroblast subpopulations from pulmonary artery adventitia in response to hypoxia. Am J Physiol Lung Cell Mol Physiol 2002; 282:L976-86. [PMID: 11943662 DOI: 10.1152/ajplung.00382.2001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Proliferation of fibroblasts contributes to the adventitial thickening observed during the development of hypoxia-induced pulmonary hypertension. However, whether all or only specific subpopulations of fibroblasts proliferate during this process is unknown. Because lung, skin, and gingiva contain multiple fibroblast subpopulations, we hypothesized that the pulmonary artery (PA) adventitia of neonatal calves is composed of multiple fibroblast subpopulations and that only selective subpopulations expand under chronic hypoxic conditions. Fibroblast subpopulations were isolated from PA adventitia of control calves using limited dilution cloning techniques. These subpopulations exhibited marked differences in morphology, actin expression, and serum-stimulated growth. Only select fibroblast subpopulations demonstrated the ability to proliferate in response to hypoxia. Fibroblast subpopulations were similarly isolated from calves exposed to hypoxia (14 days). With regard to morphology, actin expression, and serum-stimulated growth of subpopulations, there were no obvious differences in fibroblast subpopulations between the hypoxic and the control calves. However, the number of fibroblast subpopulations with about a twofold increase in hypoxia-induced DNA synthesis was significantly greater in the hypoxic calves (26%) compared with control calves (10%). We conclude that the bovine PA adventitia comprises numerous phenotypically and biochemically distinct fibroblast subpopulations and that select subpopulations expand in response to chronic hypoxia.
Collapse
|
304
|
Basu A, Mahata J, Roy AK, Sarkar JN, Poddar G, Nandy AK, Sarkar PK, Dutta PK, Banerjee A, Das M, Ray K, Roychaudhury S, Natarajan AT, Nilsson R, Giri AK. Enhanced frequency of micronuclei in individuals exposed to arsenic through drinking water in West Bengal, India. Mutat Res 2002; 516:29-40. [PMID: 11943608 DOI: 10.1016/s1383-5718(02)00014-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In West Bengal, India arsenic in ground water has been found to be above the maximum permissible limit in seven districts covering an area of 37,493km2. In the present study, evaluation of the micronuclei (MN) formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in the symptomatic individuals exposed to arsenic through drinking water. Forty five individuals with cutaneous signs of arsenicism from four affected districts (368.11 microg/l of As in drinking water) were considered as the exposed group and 21 healthy individuals with no symptoms of arsenic poisoning and residing in two unaffected districts (5.49 microg/l of As) were considered as controls. The exposed and control groups had similar age distribution and socioeconomic status. Standardised questionnaires were utilised and medical examination was conducted to ascertain exposure history, sociodemographic characteristics, diet, health, medication, addiction and chief symptoms in the study participants. Arsenic exposure was confirmed by measuring the arsenic content in the drinking water, nails, hair and urine samples from the volunteers. Arsenic contents in the urine, nail and hair in the exposed group were 24.45 microg/l, 12.58 and 6.97 microg/g, respectively which were significantly high in comparison to corresponding control group values of 4.88 microg/l, 0.51 and 0.34 microg/g, respectively. Exposed individuals showed a statistically significant increase in the frequency of MN in oral mucosa, urothelial cells and lymphocytes (5.15, 5.74 and 6.39/1000 cells, respectively) when compared with the controls (0.77, 0.56 and 0.53/1000 cells, respectively). Thus, the above results indicate that the symptomatic individuals exposed to arsenic through drinking water in this region have significant cytogenetic damage.
Collapse
|
305
|
Das M, Mpofu DJS, Hasan MY, Stewart TS. Student perceptions of tutor skills in problem-based learning tutorials. MEDICAL EDUCATION 2002; 36:272-278. [PMID: 11879518 DOI: 10.1046/j.1365-2923.2002.01148.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVE The problem-based learning (PBL) tutor plays a role that is different from the role of a teacher in a conventional teaching format. In the Faculty of Medicine and Health Sciences, United Arab Emirates, all students are Arab nationals and tutors are expatriates with different sociocultural backgrounds from the students. This study was designed to investigate how students evaluate tutors in PBL tutorials and whether student evaluations of tutors change with the progress of students in PBL tutorials. METHODS Differences in tutor performance evaluation by male and female students were also analysed. The students evaluated 12 tutor skills in a scale of 1-3, 1 being 'below average' and 3, 'outstanding'. Student responses from a total of 314 (98.1%) completed forms collected over 2 academic years were analysed statistically. A total of 14 tutors participated in the PBL programme. RESULTS The analysis revealed that tutors as a group were rated as having average to outstanding tutor skills in 10 items of the evaluation form. Students and faculty perceptions were different for the tutor skills of guiding students for information management. The students expected more support from tutors, whereas the tutors tried to emphasize self-learning in the PBL curriculum. Lower scores to the tutors in the 'problem' bringing sociocultural and religious issues for discussion showed that a gap in sociocultural/religious understanding between students and tutors might influence tutor skills. CONCLUSIONS Differences in tutor evaluation by male and female students indicate necessity of adopting different strategies by tutors in a different sociocultural background. The results of the study have direct implications for faculty development.
Collapse
|
306
|
Dey S, Arjun J, Das M, Bhattacharjee CR, Dkhar PS. Effect of prenatal lead toxicity on surface ultrastructural features, elemental composition and infrared absorption characteristics of the skin of albino mice. CYTOBIOS 2002; 106 Suppl 2:245-54. [PMID: 11545451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The epidermis and dermis of albino mice born to females receiving oral sublethal doses of lead during pregnancy developed several abnormalities. These included perforations, tissue damage, cell deformity, and disordered organization of collagen bundles, as revealed by scanning electron microscopy. An increase in the concentrations of zinc, iron, magnesium, calcium and a decrease in that of copper was evident from atomic absorption spectroscopical analysis, when entire skin tissues were examined. Infrared spectroscopy revealed the occurrence of split bands in the spectra at 1,200-1,000 cm(-1), suggesting a reduction in the symmetry of the sulphate group (glycosaminoglycans) of skin probably caused by covalent bonding of it with lead.
Collapse
|
307
|
Das M, Das AK, Gogoi GN. Discriminatory value of blood urea:creatinine ratio in upper gastrointestinal bleeding with and without cirrhosis of liver. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:243-6. [PMID: 12038656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
AIM To evaluate the discriminatory ability of blood urea:creatinine ratio in upper gastro-intestinal bleeding (UGIB) with and without cirrhosis of liver. METHODS Blood urea:creatinine (BU/CR) ratio in 160 adult patients of UGIB were studied after excluding clinically overt cirrhosis of liver, renal failure and hematochezia. All were subjected to ultrasonography of abdomen. Only those showing cirrhosis and portal hypertension (n=76) were taken up for liver biopsy to confirm the diagnosis. BU/CR ratio was compared to UGIB cases without cirrhosis of liver (n=84). RESULTS The mean (+/- SD) blood urea creatinine ratio was significantly lower in the group with cirrhosis than without cirrhosis of liver (22.49 +/- 6.13 vs. 38.07 +/- 8.08, Z value 13.91). CONCLUSION In absence of renal failure, the blood urea/creatinine ratio may differentiate UGIB with associated cirrhosis of liver from those without. Being simple, cheap and readily available, it can be of some value in those patients with cirrhosis of liver clinically not associated with gross findings of cirrhosis. In our study it was also noted that, an arbitrary cut-off value of 30 showed considerable overlap between the two groups; hence this ratio may not always differentiate between the cirrhotics and non-cirrhotics. Therefore, reproducibility of these results needs further studies, taking into account other factors which can modify the BU level in our population.
Collapse
|
308
|
Das M. An adaptive Wiener filter based technique for automated detection of defect locations from bobbin coil eddy current data. ACTA ACUST UNITED AC 2002. [DOI: 10.1063/1.1472858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
309
|
Murmu N, Mitra S, Das M, Gomes A, Vedasiromoni JR, Ghosh M, Bhattacharya M, Ghosh P, Biswas J, Bhattacharya S, Sur P. Boron compounds against human leukemic cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2001; 20:511-5. [PMID: 11876544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Two new boron compoumds, dihydroxy(oxybiguanido) boron (iii) hydrochloride monohydrate (HB) and guanidine biboric acid adduct (GB) were used in this study to observe the antitumor effect. Leukemic blast cells isolated from chronic myeloid leukemia (CML) patients showed significant cell growth inhibition within twentyfour hours. IC50 of GB and HB was 2mg/ml. The metabolically active cells were found to be inhibited by drug treatment as assessed by MTT test. Inhibition of 3H Thymidine incorporation also supported the above result. In this study we investigated the molecular mechanisms by which HB and GB induce apoptosis in immature blast cells.
Collapse
MESH Headings
- Apoptosis/drug effects
- Boron Compounds/pharmacology
- Cell Division/drug effects
- DNA, Neoplasm/metabolism
- Guanidines/pharmacology
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Tetrazolium Salts
- Thiazoles
- Thymidine/metabolism
- Tumor Cells, Cultured/drug effects
- U937 Cells/drug effects
Collapse
|
310
|
Rastogi S, Das M, Khanna SK. Quantitative determination of aflatoxin B1-oxime by column liquid chromatography with ultraviolet detection. J Chromatogr A 2001; 933:91-7. [PMID: 11758750 DOI: 10.1016/s0021-9673(01)01234-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Liquid chromatography was used for the quantification of aflatoxin B1-oxime (AFB1-oxime). The yield of AFB1-oxime in the reaction mixture was 89%, while after purification on silica gel it was 72%. LC analysis of the reaction mixture after silica gel fractionation revealed a retention time of 0.84 min for AFB1-oxime, 8.42 min for AFB1, 1.21 min for unknown 1 and 1.61 min for unknown 2. UV-visible analysis of the reaction mixture after silica gel fractionation showed a lambda(max) of 269 and 361 nm for AFB1-oxime, 263 and 360 nm for AFB1, 273 nm for unknown 1 and 275 nm for unknown 2. Excitation and emission wavelengths were found to be 269 and 368/438 nm for AFB1-oxime, 359/424 nm for AFB1, 270 and 367/450 nm for unknown 1 and 273 and 416/447 nm for unknown 2. The method may find versatile application in monitoring reactions for the preparation of oximes of various analytes for the synthesis of their immunogens.
Collapse
|
311
|
Dua T, Das M, Kabra M, Bhatia M, Sarkar C, Arora S, Sharma MC, Kalra V. Spectrum of floppy children in Indian scenario. Indian Pediatr 2001; 38:1236-43. [PMID: 11721063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE To study the clinical profile of paralytic floppy infants undertaking available investigations and detect the frequency of exon7 of survival motor neuron (SMNT) gene deletion among the spinal muscular atrophy (SMA) cases. DESIGN Descriptive study. SETTING Tertiary care teaching hospital. SUBJECTS 70 paralytic floppy infants (40 males/30 females) with age less than 13 years were included in the study. Exclusion criteria included central hypotonia of any cause. Detailed clinical evaluation was done followed by serum creatine phosphokinase levels, electrophysiological studies, muscle biopsy including immunohistochemistry and electron microscopy. Exon7 of SMNT gene deletion studies was done by PCR. RESULTS Final diagnosis of SMA was assigned to 37 patients followed by congenital myopathy (n = 7), cogenital muscular dystrophy (n = 5), mitochondrial myopathy (n = 4), neuropathies (n = 5) and diaphragmatic SMA (n = 1). Only 15.7% of cases remained unclassified. When EMG was correlated with final diagnosis, it was 80.6% and 75% sensitive and 68.8% and 87.5% specific for neurogenic and muscle disease, respectively. Muscle biopsy revealed neurogenic atrophy in 47.8% cases followed by normal in 37.3% and myopathic pattern in 14.97% cases. Exon7 of SMNT gene was deleted in only 50% of SMA cases. CONCLUSIONS Spinal muscular atrophy was the commonest cause of floppy children. The low rate of SMNT gene deletion detected needs confirmation with further studies.
Collapse
|
312
|
Koley J, Das M, Basak AK, Koley BN. Ventricular nociception induced vesicular motility and urine flow: their relationship. INDIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2001; 45:463-9. [PMID: 11883154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Heart acts as an important reflexogenic organ. Reflex urination and defaecation are two of the most important visceral symptoms observed in patients with myocardial ischaemia, infarction etc. In experimental animals also ventricular nociceptor stimulation by left anterior descending coronary artery (LAD) occlusion and nicotine application causes biphasic changes in urinary bladder movement and urine flow. Aim of the present study is to elucidate if there is any correlation between urine formation by the kidneys and movement of the urinary ladder under such experimental conditions. The experiments performed on intact cats show apparent coincidence of the two events. But, subsequent experiments following denervation of vagi and inferior cardiac nerve (ICN), spinal transaction and decerebration experiments indicate that these two are separate events. Further, experiments with different neurotransmitter blockers indicate that ventricular nocieptor induced urine formation and urinary bladder movements are two separate reflex responses and not dependent on each other.
Collapse
|
313
|
Baruah M, Das M, Sengupta S. Food and feeding of Amphiesma stolatum (Linnaeus 1758). JOURNAL OF ENVIRONMENTAL BIOLOGY 2001; 22:315-317. [PMID: 12018606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The food and feeding behaviour of Amphiesma stolatum was studied. A total of 117 snakes were examined to analyse the diet composition. Ten live snakes were maintained in enclosure for evaluating the feeding habit, choice of food and rate of assimilation. The anurans constituted the major diet of the food spectrum. In captivity, fishes (fry), amphibians and reptiles were consumed by the snakes. A. stolatum exihibited Elaphe type of hunting behaviour. In most cases the snake struck the prey at its head. The assimilation rate with frog was highest.
Collapse
|
314
|
Das M, Burge CB, Park E, Colinas J, Pelletier J. Assessment of the total number of human transcription units. Genomics 2001; 77:71-8. [PMID: 11543635 DOI: 10.1006/geno.2001.6620] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Variation in the estimates of the number of genes encoded by the human genome (28,000-120,000) attests to the difficulty of systematically identifying human genes. Sequencing of human chromosome 22 (Chr22) provided the first comprehensive, unbiased view of an entire human chromosome, and intensive analysis of this sequence identified 545 genes and 134 pseudogenes that had similarity or identity to known proteins and/or ESTs and which were listed in the gene annotation (http://www.sanger.ac.uk/HGP/Chr22). This analysis yielded an estimate of approximately 36,000 functional expressed genes in the human genome (and 9000 pseudogenes). However, a key uncertainty in this estimate was that hundreds of additional genes beyond those annotated in the Chr22 sequence are predicted by the gene prediction program Genscan, an unknown number of which might represent additional expressed genes. To determine what fraction of these "predicted novel genes" (PNGs) represents expressed human genes, we used a sensitive RT-PCR assay to detect predicted transcripts in 17 tissues and one cell line. Our results indicate that at least 5000-9000 additional human genes which lack similarity to known genes or proteins exist in the human genome, increasing baseline gene estimates to approximately 41,000-45,000.
Collapse
|
315
|
Bandyopadhyay S, Roychowdhury K, Chandra S, Das M, Dasgupta UB. Variable severity of beta-thalassemia patients of eastern India: effect of alpha-thalassemia and xmnI polymorphism. Clin Exp Med 2001; 1:155-9. [PMID: 11833853 DOI: 10.1007/s10238-001-8028-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Sixty-four thalassemia and E-beta thalassemia patients were studied for factors that modulate the severity of the disease; i.e., mutation of beta-globin gene, presence of alpha-deletion, and presence of an XmnI site at the -158 position of the Gy gene. Presence of alpha-deletion and/or homozygosity for the XmnI site was in general associated with less-severe disease. About 12% of the patients harbored single alpha-gene deletion, and the gene frequency of the XmnI polymophism in these patients is 0.48.
Collapse
|
316
|
Das M. Characterization of de-emulsification capabilities of a Micrococcus species. BIORESOURCE TECHNOLOGY 2001; 79:15-22. [PMID: 11396902 DOI: 10.1016/s0960-8524(01)00039-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Effect of post harvest washing as well as cell concentration on de-emulsification characteristics of an isolated Micrococcus species has been tested with Tween 60 Span 60 stabilised oil in water (o/w) and L-92 pluronic surfactant stabilised water in oil (w/o) model emulsions (kerosene water). The cells used were 140 h old and grown under submerged conditions at 37 degrees C in a medium containing n-tetradecane (4% v/v) as the carbon source. The harvested bacterial cells when in an unwashed condition (at a cell concentration of 2 mg/ml of emulsion) were found to de-emulsify the o/w system at a much faster rate than the w/o system exhibiting half-life values for the respective system as 10.2 and 127.7 h. Post harvest washing of the cells with any lipid solubilising solvent (n-pentane, n-hexane, kerosene, chloroform-methanol-water (CMW)) yielded a decrease in their de-emulsification power for w/o emulsion. But the decay of o/w emulsion became faster with n-pentane- and kerosene-washed cells as evident from their corresponding half-life values of 3.3 and 4.6 h. Compared to the w/o system, an increase in the concentration of kerosene-washed cell had a direct effect on de-emulsification for the o/w system. For cell concentrations of 2, 3 and 4 mg/ml of the emulsion, the half-life values for the w/o system were 364.8, 442.0 and 454.9 h, respectively. For 2 and 4 mg/ml cell contents, the half-life values for the o/w system were 4.6 and 1.0 h. The decay of both the emulsions was very slow or even incomplete for cell concentrations less than 2 mg/ml. De-emulsifying capacity of the n-tetradecane grown Micrococcus species towards o/w model emulsion improved considerably after washing the cells with n-pentane and kerosene, and use of kerosene-washed cells (4 mg/ml) reduced the half-life to 1 h.
Collapse
|
317
|
Das M, Dasgupta SC, Gomes A. Isolation, purification and partial chemical characterization of a lethal factor from common indian toad (Bufo melanostictus, Schneider) skin extract. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2001; 39:781-5. [PMID: 12018580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Indian toad (Bufo melanostictus, Schneider) skin extract (TSE) is pharmacologically potent and probably contains several bioactive compounds [Das et. al., Indian J Pharmacol, 28 (1996) 72]. A lethal factor was isolated and purified by neutral alumina column chromatography followed by HPLC. Spectroscopic (UV, IR, FAB-MASS) study indicated that the lethal factor (TSE-LF) was a 254 Da long chain compound with carbonyl, hydroxyl and ester as functional groups. LD50 of TSE-LF was found to be 3.5 mg/kg (iv). Biological study showed that TSE-LF possesses hypotensive, cardiotoxic, neurotoxic activity and produced death by apnoea in experimental animal. Cyproheptadine antagonised TSE-LF induced contraction of isolated smooth muscle indicating involvement of histamine/serotonin receptors. TSE-LF induced neurotoxic action on chick biventer cervices was mediated through Ca2+ ion.
Collapse
|
318
|
Abstract
The development of functional genomic resources is essential to understand and utilize information generated from genome sequencing projects. Central to the development of this technology is the creation of high-quality cDNA resources and improved technologies for analyzing coding and noncoding mRNA sequences. The isolation and mapping of cDNAs is an entrée to characterizing the information that is of significant biological relevance in the genome of an organism. However, a bottleneck is often encountered when attempting to bring to full-length (or at least full-coding) a number of incomplete cDNAs in parallel, since this involves the nonsystematic, time consuming, and labor-intensive iterative screening of a number of cDNA libraries of variable quality and/or directed strategies to process individual clones (e.g., 5' rapid amplification of cDNA ends). Here, we review the current state of the art in cDNA library generation, as well as present an analysis of the different steps involved in cDNA library generation.
Collapse
|
319
|
Goluszko P, Niesel D, Nowicki B, Selvarangan R, Nowicki S, Hart A, Pawelczyk E, Das M, Urvil P, Hasan R. Dr operon-associated invasiveness of Escherichia coli from pregnant patients with pyelonephritis. Infect Immun 2001; 69:4678-80. [PMID: 11402015 PMCID: PMC98548 DOI: 10.1128/iai.69.7.4678-4680.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We used a gentamicin protection assay to assess the ability of gestational pyelonephritis isolates of Escherichia coli to invade HeLa cells. The ability to enter HeLa cells was strongly associated with the presence of Dr operons coding for Dr adhesins. In contrast, the nonivasive isolates predominantly expressed papG, coding for P fimbriae.
Collapse
|
320
|
Slotwiner DJ, Stein KM, Markowitz SM, Mittal S, Iwai S, Das M, Lerman BB. Emerging indications for cardiac pacing. HEART DISEASE (HAGERSTOWN, MD.) 2001; 3:224-30. [PMID: 11975798 DOI: 10.1097/00132580-200107000-00004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Substantial data have been accumulated and indications have been well delineated for pacemaker implantation in the treatment of sinus node dysfunction and heart block. However, many other indications have been proposed for pacemaker implantation. In this review, the authors examine available data regarding pacemaker implantation for new indications: neurally mediated syncope, hypertrophic obstructive cardiomyopathy, congestive heart failure, prevention of atrial fibrillation, and the relative merits of single-chamber and dual-chamber pacemakers.
Collapse
|
321
|
Das M, Mukherjee SB, Shaha C. Hydrogen peroxide induces apoptosis-like death in Leishmania donovani promastigotes. J Cell Sci 2001; 114:2461-9. [PMID: 11559754 DOI: 10.1242/jcs.114.13.2461] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leishmania donovani promastigotes introduced into the bloodstream by sandfly vectors, are exposed to reactive oxygen species like H2O2 during phagocytosis by the host macrophages. H2O2 can induce promastigote death, but the mechanism of induction of this death is not known. Studies presented in this paper demonstrate that exposure to 4 mM H2O2 results in a pattern of promastigote death that shares many features with metazoan apoptosis. Motility and cell survival in these parasites show a gradual decline with increasing doses of H2O2. Features common to metazoan apoptosis, such as nuclear condensation, DNA fragmentation with accompanying DNA ladder formation and loss of cell volume, are observed after exposure to 4 mM H2O2. Within 30 minutes of the exposure, there is a significant increase in the ability of the cell lysates to cleave the fluorogenic tetrapeptide acetyl-Asp-Glu-Val-Asp-7-amino-4-trifluoromethyl coumarin, which is a substrate for the CED-3/CPP32 group of proteases. Pretreatment of cells with a specific inhibitor of CED-3/CPP32 group of proteases, Z-DEVD-FMK, reduces the number of cells showing apoptosis-like features, prevents DNA breakage and inhibits cleavage of a PARP-like protein. Activation of the caspase-like proteases is followed at 2 hours by the cleavage of a poly(ADP)ribose-polymerase-like protein and a reduction in intracellular glutathione concentration. DNA breakdown as detected by TdT labelling of cells and agarose gel electrophoresis is visible at 6 hours. Taken together, the above data show for the first time that there is a distinct pathway for apoptosis-like death in L. donovani.
Collapse
|
322
|
Srivastava AC, Pal M, Das M, Sengupta UK. Growth, CO2 exchange rate and dry matter partitioning in mungbean (Vigna radiata L.) grown under elevated CO2. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2001; 39:572-7. [PMID: 12562021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
This study was conducted to determine the effects of anticipated future level of CO2 on growth and dry matter partitioning of mungbean (Vigna radiata). Plants were grown from seedlings to maturity inside the open top chamber under amhient CO2 (350 +/- 25 microL L(-1)) and elevated CO2 (600 +/- 50 microL L(-1)) at Indian Agricultural Research Institute, New Delhi (India). Plants were harvested at 20, 35 and 50 days after germination. Mungbean plants grown under elevated CO2 concentration resulted in greater photosynthetic rate on a leaflet area basis and no acclimation in photosynthesis was recorded due to high CO2. Plants grown under CO, enrichmcnt were taller and attained greater leaf area along with more dry matter than ambient CO2 grown plants at all growth stages. Response to high CO, depends upon the growth stage of the plant and it was more at early growth stages compared to maturity stages. The high CO2 grown mungbean plants also exhibited increased root growth along with stem and leaves. There was a substantial increase in pod number and seed number/plant under elevated CO2 conditions. The increase in dry matter and growth of root, stem and leaves proved that CO2 enrichment of the atmosphere can stimulate photosynthetic rate which can ultimately lead to an increase in dry matter and growth.
Collapse
|
323
|
Abstract
Previous studies indicate that benzanthrone, an anthraquinone dye intermediate, caused significant depletion of ascorbic acid (AsA). In this investigation the effect of benzanthrone on the status of different forms of AsA and other bio-antioxidants such as glutathione (GSH) was studied. Oral administration of benzanthrone (50, 125 or 250 mg/kg body weight) resulted in a significant increase of urinary AsA levels with a concomitant decrease in the urinary dehydroascorbic acid (DHA) content in both rats and guinea-pigs. Benzanthrone caused a dose-dependent decrease in hepatic, adrenal and serum AsA levels with a subsequent increase in DHA and diketogulonic acid (DKA) levels in both rats and guinea-pigs. Following benzanthrone treatment, rats showed an increase in the scorbutic index (to 1.01-1.21) of the liver, adrenal glands and serum compared to controls (0.12-0.24). The scorbutic indices of liver, adrenal glands and serum were also substantially increased (to 3.61-11.20) in benzanthrone-treated guinea-pigs compared to controls (0.16-0.38). Single oral administration of benzanthrone to guinea-pigs caused a dose-dependent depletion of GSH in liver (15-51%), adrenal glands (27-64%) and serum (32-86%). Furthermore, the depletion of GSH by benzanthrone in rats was of a lesser degree. This suggests that continued exposure of guinea-pigs to benzanthrone may lead to scurvy-type changes in this animal species but not to the same extent in rats, since the latter has the enzymatic capacity to synthesise AsA. Therefore, it can be hypothesised that benzanthrone per se, or its metabolites, interact with reduced GSH thereby causing its depletion. Furthermore, in order to replenish the depleted GSH levels, AsA might be oxidized to DHA and hence the decrease in AsA with the simultaneous increase in DHA was observed.
Collapse
|
324
|
Das M, Bouchey DM, Moore MJ, Hopkins DC, Nemenoff RA, Stenmark KR. Hypoxia-induced proliferative response of vascular adventitial fibroblasts is dependent on g protein-mediated activation of mitogen-activated protein kinases. J Biol Chem 2001; 276:15631-40. [PMID: 11278727 DOI: 10.1074/jbc.m010690200] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypoxia has been shown to act as a proliferative stimulus for adventitial fibroblasts of the pulmonary artery. The signaling pathways involved in this growth response, however, remain unclear. We tested the hypothesis that hypoxia-induced proliferation of fibroblasts would be dependent on distinct (compared with serum) activation and utilization patterns of mitogen-activated protein (MAP) kinases initiated by Galpha(i/o) proteins. We found that hypoxia stimulated increases in DNA synthesis and growth of quiescent fibroblasts in the absence of exogenous mitogens and also markedly augmented serum-stimulated growth responses. Hypoxia caused a transient activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), the time course and pattern of which was somewhat similar to that induced by serum but which was of lesser magnitude. On the other hand, hypoxia-induced activation of p38 MAP kinase was biphasic, whereas serum-stimulated activation of p38 MAP kinase was transient, and the magnitude of activation was greater for hypoxia compared with that of serum stimulation. ERK1/2, JNK1, and p38 MAP kinase but not JNK2 were necessary for hypoxia-induced proliferation because PD98059, SB202190, and JNK1 antisense oligonucleotides nearly ablated the growth response. JNK2 appeared to act as a negative modulator of hypoxia-induced growth because JNK2 antisense oligonucleotides led to an increase in DNA synthesis. In serum-stimulated cells, antisense JNK1 oligonucleotides and PD98059 had inhibitory effects on proliferation, whereas SB202190 led to an increase in DNA synthesis. Pertussis toxin, which blocks Galpha(i/o)-mediated signaling, markedly attenuated hypoxia-induced DNA synthesis and activation of ERK and JNK but not p38 MAP kinase. We conclude that hypoxia itself can act as a growth promoting stimulus for subsets of bovine neonatal adventitial fibroblasts largely through Galpha(i/o)-mediated activation of a complex network of MAP kinases whose specific contributions to hypoxia-induced proliferation differ from traditional serum-induced growth signals.
Collapse
MESH Headings
- Animals
- Animals, Newborn
- Aorta, Thoracic/cytology
- Aorta, Thoracic/physiology
- Cattle
- Cell Division/drug effects
- Cell Hypoxia/physiology
- Cells, Cultured
- Culture Media, Serum-Free
- Enzyme Inhibitors/pharmacology
- Fibroblasts/cytology
- Fibroblasts/physiology
- GTP-Binding Proteins/metabolism
- Imidazoles/pharmacology
- JNK Mitogen-Activated Protein Kinases
- Kinetics
- MAP Kinase Signaling System/physiology
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinase 8
- Mitogen-Activated Protein Kinase 9
- Mitogen-Activated Protein Kinases/antagonists & inhibitors
- Mitogen-Activated Protein Kinases/genetics
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/physiology
- Oligodeoxyribonucleotides, Antisense/pharmacology
- Pertussis Toxin
- Phosphorylation
- Pulmonary Artery/cytology
- Pulmonary Artery/physiology
- Pyridines/pharmacology
- Virulence Factors, Bordetella/pharmacology
- p38 Mitogen-Activated Protein Kinases
Collapse
|
325
|
Gomes A, Das M, Dasgupta SC. Haematinic effect of Hygrophila spinosa T. Anderson on experimental rodents. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2001; 39:381-2. [PMID: 11491586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Ethanolic extract of the aerial parts of H. spinosa a semiwoody herb was examined on male albino rats for certain haematological changes. The extract (100 & 200 mg/kg, po) significantly increased the haemoglobin, haematocrit, RBC and total WBC, as compared with vehicle treated control rat haemogram. In anemic male albino rats, the extract significantly increased haemoglobin, haematocrit and RBC count. Serum iron and serum total iron binding capacity were significantly decreased in H. spinosa extract treated anemic rats as compared with those in the vehicle treated anemic control rats. These findings demonstrated the haematinic effect of H. spinosa extract on experimental animals.
Collapse
|