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Sarkar R, Mohanakumar K, Chowdhury M. Effects of an organophosphate pesticide, quinalphos, on the hypothalamo-pituitary-gonadal axis in adult male rats. Reproduction 2000. [DOI: 10.1530/jrf.0.1180029] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sarkar R, Mohanakumar KP, Chowdhury M. Effects of an organophosphate pesticide, quinalphos, on the hypothalamo-pituitary-gonadal axis in adult male rats. JOURNAL OF REPRODUCTION AND FERTILITY 2000; 118:29-38. [PMID: 10793623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The effects of chronic sub-lethal doses (7-14 mg kg-1 a day for 15 days) of quinalphos were evaluated in adult male rats for changes in testicular morphology, circulatory concentrations of hormones (LH, FSH, prolactin and testosterone), activities of acetylcholinesterase (AChE) and angiotensin converting enzyme (ACE) as well as metabolism of biogenic amines (dopamine, noradrenaline and 5-hydroxytryptamine (5-HT)) in the hypothalamus and pituitary. Hormones were assayed by radioimmunoassay or chemiluminescent immunoassay (testosterone). The enzymes were estimated after spectrophotometry and the biogenic amines by HPLC-electrochemistry. Sub-lethal chronic administration of quinalphos resulted in: decreased testicular mass and AChE activity in central as well as peripheral organs; increased serum LH, FSH, prolactin and testosterone concentrations; decreased pituitary or increased testicular ACE activity; severe disruption of spermatogenesis with increasing doses of pesticide; and no significant effects on dopamine, noradrenaline or 5-HT concentrations in the hypothalamus or pituitary. Administration of oestradiol (50 micrograms per rat a day) during pesticide treatment resulted in: a significant decrease in the mass of the testis and accessory sex organs; decreases in serum LH, FSH, testosterone concentrations; an increase in prolactin concentration; and a decrease in dopamine or an increase in noradrenaline and 5-HT in the hypothalamus or pituitary. Oestradiol had a marked effect: in pesticide-treated animals, the pesticide effects were significantly reversed. This indicates that in pesticide toxicity, the hypothalamo-pituitary-gonadal axis is operational. Since many of the observed pesticide effects could be inhibited by oestradiol, it is suggested that the pesticide acts directly on the gonadotrophins. In conclusion, quinalphos decreases fertility in adult male rats by affecting the pituitary gonadotrophins.
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Sarkar R, Mohanakumar KP, Chowdhury M. Effects of an organophosphate pesticide, quinalphos, on the hypothalamo-pituitary-gonadal axis in adult male rats. Reproduction 2000. [DOI: 10.1530/reprod/118.1.29] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The effects of chronic sub-lethal doses (7-14 mg kg-1 a day for 15 days) of quinalphos were evaluated in adult male rats for changes in testicular morphology, circulatory concentrations of hormones (LH, FSH, prolactin and testosterone), activities of acetylcholinesterase (AChE) and angiotensin converting enzyme (ACE) as well as metabolism of biogenic amines (dopamine, noradrenaline and 5-hydroxytryptamine (5-HT)) in the hypothalamus and pituitary. Hormones were assayed by radioimmunoassay or chemiluminescent immunoassay (testosterone). The enzymes were estimated after spectrophotometry and the biogenic amines by HPLC-electrochemistry. Sub-lethal chronic administration of quinalphos resulted in: decreased testicular mass and AChE activity in central as well as peripheral organs; increased serum LH, FSH, prolactin and testosterone concentrations; decreased pituitary or increased testicular ACE activity; severe disruption of spermatogenesis with increasing doses of pesticide; and no significant effects on dopamine, noradrenaline or 5-HT concentrations in the hypothalamus or pituitary. Administration of oestradiol (50 micrograms per rat a day) during pesticide treatment resulted in: a significant decrease in the mass of the testis and accessory sex organs; decreases in serum LH, FSH, testosterone concentrations; an increase in prolactin concentration; and a decrease in dopamine or an increase in noradrenaline and 5-HT in the hypothalamus or pituitary. Oestradiol had a marked effect: in pesticide-treated animals, the pesticide effects were significantly reversed. This indicates that in pesticide toxicity, the hypothalamo-pituitary-gonadal axis is operational. Since many of the observed pesticide effects could be inhibited by oestradiol, it is suggested that the pesticide acts directly on the gonadotrophins. In conclusion, quinalphos decreases fertility in adult male rats by affecting the pituitary gonadotrophins.
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Abstract
Female rats at weaning (30 days age) were maintained on vitamin E-deficient diet for 70 days. The vitamin E-deficient and control animals were sacrificed on 100 days of age. To study recovery a group of animals were supplemented with normal diet for last 25 days after initial 45 days of deficient diet or vice versa. The most striking data found were (i) significant drop in uterine weight in deficient group (ii) significant decrease in estrogen, LH and estrogen-induced uterine enzymes alkaline phosphatase and peroxidase and (iii) ovarian dysfunction as noted by degenerating graffian follicles. The significance of these findings is discussed in this report.
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Sueta CA, Chowdhury M, Boccuzzi SJ, Smith SC, Alexander CM, Londhe A, Lulla A, Simpson RJ. Analysis of the degree of undertreatment of hyperlipidemia and congestive heart failure secondary to coronary artery disease. Am J Cardiol 1999; 83:1303-7. [PMID: 10235085 DOI: 10.1016/s0002-9149(99)00117-4] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
There is a lack of data evaluating the implementation of guidelines in the management of coronary artery disease (CAD) or congestive heart failure (CHF) in the outpatient setting. We analyzed an administrative data set from the Merck & Co. sponsored national Quality Assurance Program, a retrospective outpatient chart audit of 58,890 adult outpatients from 140 medical practices (80% cardiology only) in the USA with diagnoses of CAD and/or CHF identified from medical claims data. We determined the (1) frequency of lipid documentation and prescription of lipid-lowering agents in patients with CAD, (2) frequency of assessment of left ventricular function and prescription of an angiotensin-converting enzyme inhibitor in patients with CHF, and (3) predictors of medication prescription. Of the 48,586 patients with CAD, 44% had annual diagnostic testing of low-density lipoprotein cholesterol. Only 25% of these patients reached the target low-density lipoprotein cholesterol of < or = 100 mg/dl, and only 39% were taking lipid-lowering therapy, which was less among the elderly than in the younger patients. Of the 16,603 patients with CHF, 64% had diagnostic testing of left ventricular function, and 50% of patients were taking an angiotensin-converting enzyme inhibitor; 67% of patients received medication if they had documented systolic dysfunction. Significant predictors of medication prescription included diagnostic testing, younger age, history of myocardial infarction or coronary artery bypass grafting, hypertension, cardiology specialty, and geographic region. Thus, current practice patterns in the management of CAD and CHF are inadequate. Patient age, diagnostic testing, and practice environment influence medication prescription.
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81
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Mehta M, Chowdhury M. A mannose-binding glycoprotein found in the 4 day post coital rat uterus is involved in pregnancy. Mol Cell Biochem 1999; 195:65-75. [PMID: 10395070 DOI: 10.1023/a:1006901206170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Experiments were conducted to study the functional implication of a mannose-binding glycoprotein found in the day 4 post coital (p.c.) rat uterus, using a mono-specific polyclonal antibody raised against the glycoprotein. Western Blot and immunohistochemical techniques were employed to study the distribution of the glycoprotein, and the results suggest that this glycoprotein is present only in the day 4 p.c. uterus and is specifically localized in the stromal cells. Administration of anti-UA (Uterine Agglutinin) antiserum against the glycoprotein into the day 4 p.c. uterine lumen inhibits carrying of embryo to term. The antiserum is not embryo toxic. After in vivo in utero intra-luminal administration of anti-UA antiserum in day 4 p.c. rat the antiserum has been specifically localized in the uterine stroma by immunohistochemistry. After intravenous injection, the glycoprotein is cleared mainly through the kidney and liver. The possible role of this glycoprotein in the implantation process in rats has been discussed. From the data it is evident that UA may not be directly involved in sugar-sugar interactions with embryo since it is not present in any significant amount in pregnant uterus from day 5 onwards. Since other experiments show that UA does have some role to play in early pregnancy, UA probably acts through some other factor, and preliminary studies suggest that this factor maybe TGF-beta3.
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82
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de Bri E, Lei W, Svensson O, Chowdhury M, Moak SA, Greenwald RA. Effect of an inhibitor of matrix metalloproteinases on spontaneous osteoarthritis in guinea pigs. Adv Dent Res 1998; 12:82-5. [PMID: 9972127 DOI: 10.1177/08959374980120012601] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of matrix metalloproteinase (MMP)-mediated connective tissue destruction in a variety of pathologic processes, including rheumatoid arthritis and osteoarthritis (OA). Since the histologic techniques used in our laboratory have been validated in Hartley guinea pigs, which have a high incidence of OA-like changes in the proximal tibia, we have used two tetracyclines which have potent inhibitory capacity against various MMPs, doxycycline (Dox) and a compound known as chemically modified tetracyclines (CMT-7). These were given by mouth to a group of guinea pigs for 4 to 8 months, and we assessed the effect of the compound on morphologic and biochemical aspects of OA. We found that prophylactic CMT-7 given orally decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation, were all decreased in the central compartment of the medial condyle, which is most affected by OA compared with controls. Also collagen, hyaluronan and proteoglycancontent in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. Our results confirm that various tetracyclines have reduced the severity of OA in animal models, indicating the therapeutic potential of this class of compounds in the future.
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Sueta C, Chowdhury M, Biggs D, Boccuzzi S, Smith S, Simpson R. Regional variation in the prescription of lipid lowering therapy in patients with coronary artery disease. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)81449-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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85
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Greenwald RA, Golub LM, Ramamurthy NS, Chowdhury M, Moak SA, Sorsa T. In vitro sensitivity of the three mammalian collagenases to tetracycline inhibition: relationship to bone and cartilage degradation. Bone 1998; 22:33-8. [PMID: 9437511 DOI: 10.1016/s8756-3282(97)00221-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
There are at least nine tetracycline (TC) analogs (both antimicrobial and nonantimicrobial) with documented capacity to inhibit, both in vitro and in vivo, the connective tissue degrading activity of matrix metalloproteinases (MMPs). Of the three MMPs that can degrade native helical collagens, MMP-13 (initially identified as rat osteoblast and human breast cancer collagenase, and now known to also be expressed by human cartilage and bone cells) is the most sensitive to TC inhibition (IC50 values in vitro generally less than 1 microgram/mL); the TCs inhibit both the collagenolytic as well as the gelatinolytic activity of this enzyme. The IC50 for MMP-8 (neutrophil collagenase) in vitro ranges from 15 to 86 micrograms/mL depending on assay conditions and choice of TC, whereas inhibition of the fibroblast enzyme (MMP-1) generally requires levels in excess of 200 micrograms/mL (except for CMT-3). The TC compounds that are highly effective against MMP-13 in vitro are also highly inhibitory of glycosaminoglycan release from interleukin-1-stimulated cartilage explants in culture. The current data correlate well with: (i) literature values for TC inhibition of bone resorption by isolated osteoclasts; (ii) inhibition by TCs of avian tibial resorption in organ culture; and (iii) the dramatic ability of TCs to inhibit bone destruction in many rat models (rats have only MMP-8 and MMP-13, and no MMP-1). By carefully selecting a TC-based MMP inhibitor and controlling dosages, it should be possible to inhibit pathologically excessive MMP-8 and/or MMP-13 activity, especially that causing bone erosion, without affecting the constitutive levels of MMP-1 needed for tissue remodeling and normal host function; in this regard, three newly developed CMTs (especially CMT-8, and, to a lesser extent, CMT-3 and -7) appear to be most effective.
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86
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Mehta M, Chowdhury M. The effect of anti-prolactin antibody on in vitro synthesis of a pregnancy-associated rat uterine glycoprotein. Mol Cell Biochem 1997; 177:131-8. [PMID: 9450654 DOI: 10.1023/a:1006897011859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Experiments were conducted to study the hormonal (estrogen [E2], progesterone [P4] and prolactin [PRL]), regulation of synthesis of a pregnancy-associated glycoprotein (named Uterine Agglutinin or UA) in the Day 4 post coital (p.c.) rat uterus with antibody administration and immunohistochemistry. Of the antibodies used, it was shown that anti-PRL antibody was the most effective in reducing in vitro UA synthesis. The results suggested that in vitro UA synthesis could be correlated to serum PRL levels as analyzed by radio-immunoassay. Binding studies revealed that PRL bound specifically to the stromal cells of the rat uterus where UA is produced and localized.
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Abstract
The data for this study come from Matlab, a rural area of Bangladesh, where a continuous registration of demographic events has been maintained by the International Centre for Diarrhoeal Disease Research, Bangladesh since 1966. A total of 11,951 first marriages of Muslims that took place in the area between 1975 and 1987 were followed until the end of 1989, to examine the relationship between parental marriage breakdown and survival of first live-born children. The impact of divorce on survival of children during infancy and childhood was examined, using hazard analysis. Other independent variables included age of mother at birth, and mother's education, year of birth, sex of children, and residence at the time of childbirth. It is shown that the net odds of death among children of divorced mothers in infancy and childhood were respectively 3.2 and 1.4 times higher than those of mothers whose marriages continued. The paper also discussed the possible mechanisms which link divorce and child survival.
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88
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Banerjee M, Chowdhury M. Localization of a 25 kDa human sperm surface protein: its role in in-vitro human sperm capacitation. Mol Hum Reprod 1997; 3:109-14. [PMID: 9239716 DOI: 10.1093/molehr/3.2.109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A human endometrial sialic acid-binding glycoprotein (SABP) binds specifically to a 25 kDa protein on the plasma membranes of human non-capacitated sperm heads. In-vitro labelling of the sperm surface sialoglycoconjugates and subsequent incubation with SABP, suggests removal of some sialoglycoconjugate moieties from the sperm surface upon interaction with SABP. SABP also induces the exposure of mannose ligand receptors on the sperm surface and increases the production of superoxide anion (O2-).
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89
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Khan MI, Bhuiya A, Chowdhury M. Cultural construction of health and institutional measures of change in rural Bangladesh: cases of BRAC's village organization and ICDDR,B's MCH-FP programmes. GLIMPSE (DHAKA, BANGLADESH) 1996; 18:8. [PMID: 12291504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
The study aims to examine the perceptions, causes, and treatment of diseases among the people of a few selected villages in Matlab and their relation to traditional culture and interventions made by BRAC and ICDDR,B in the form of rural development and MCH-FP programs. Four sets of villages were chosen purposively--two DSS and the other two non-DSS. In one of the DSS villages the MCH-FP program is underway, while the other does not have such programs. Likewise, one of the non-DSS villages has the rural development program of BRAC, while the other does not have any. From each village 10 respondents were selected purposively to gather information. The perception of disease is mostly defined in terms of the functions of the body. On very few occasions it is defined in terms of the action rendered by germs or the pathological condition of the body organs. The difference between the meaning and the actual diseases is often blurred. While identifying the causes, often the reference is made to invisible spirits, locally known as alga batash. The modes of treatment combine both modern and traditional elements. However, the health teaching educates them about the perception, causes, and treatment of certain diseases. In society, the elderly people, religious preachers, and traditional healers play important roles to influence the mind of the people. Sometimes gender relations and other structural features also bear on the minds of the illiterate poor. The difference between the intervention and non-intervention villages is expressed in the fact that the people of the intervention villages are constantly exposed to the agents making changes, while in the non-intervention villages it is intermittent. Traditional culture still plays an important role in the construction of disease perception and the choice of treatment, while modern approaches are combined with it. The intervention procedures widen modern approaches but could not eliminate the traditional notions altogether.
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90
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Bhuiya A, Chowdhury M, Khan SR. Impact of BRAC's socioeconomic development programme on fertility and mortality in Matlab. GLIMPSE (DHAKA, BANGLADESH) 1996; 18:7-8. [PMID: 12291503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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91
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Chowdhury M. Safe delivery programme in Bangladesh: the role of TBAs. HEALTH FOR THE MILLIONS 1996; 22:23-4. [PMID: 12347746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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92
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Banerjee M, Chowdhury M. Induction of capacitation in human spermatozoa in vitro by an endometrial sialic acid-binding protein. Hum Reprod 1995; 10:3147-53. [PMID: 8822433 DOI: 10.1093/oxfordjournals.humrep.a135877] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A Ca(2+)-dependent sialic acid-binding protein (SABP) of human endometrium, which specifically bound to human sperm head plasma membrane in vitro, was found to increase the percentage motility and acrosome-reacted pattern of uncapacitated spermatozoa. The protein was synthesized in the endometrium and secreted into the uterine fluid. This intra-uterine factor, which is apparently advantageous in vitro in inducing human sperm capacitation, may play a significant role in promoting the post-release maturation of ejaculated spermatozoa by enhancing 45Ca uptake into spermatozoa by a pathway which is insensitive to calcium-channel blockers. However, the 45Ca uptake could be enhanced on exposure to the divalent cation ionophore A23187 and inhibited in the presence of the calmodulin inhibitor trifluoperazine. The SABP also induces an increase in intracellular Ca2+ in spermatozoa, as seen by FURA-2 AM studies. Furthermore, overlay studies show human SABP to be a Ca(2+)-binding protein. The data presented here suggest that SABP induces in-vitro sperm capacitation and the subsequent acrosome reaction by increasing intracellular Ca2+ concentration.
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93
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Bhuiya A, Bhuiya I, Chowdhury M. Factors affecting acceptance of immunization among children in rural Bangladesh. Health Policy Plan 1995; 10:304-12. [PMID: 10151848 DOI: 10.1093/heapol/10.3.304] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper uses the Bangladesh Fertility Survey 1989 data to identify the factors affecting acceptance of immunization among children in rural Bangladesh. Acceptance of DPT, measles and BCG vaccinations were the dependent variables. The independent variables included proximity to health facilities, frequency of visit by health worker, respondent's mobility, media exposure, education, age, economic status of household, region of residence, and gender of child. Logistic regression analysis was performed to assess the net effects of the variables in addition to univariate analysis. Among the independent variables, proximity to health facility, frequency of health worker's visit, mother's mobility, education, age, gender of child, ownership of radio, economic condition of household, and region of residence showed statistically significant association with acceptance of immunization. The effect of frequency of health worker's visit was dependent on region of residence, possession of radio, and mother's education. The effect of mother's ability to visit health centre alone was also dependent on ownership of radio, economic condition of household, and mother's education.
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94
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Goodburn EA, Gazi R, Chowdhury M. Beliefs and practices regarding delivery and postpartum maternal morbidity in rural Bangladesh. Stud Fam Plann 1995; 26:22-32. [PMID: 7785065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Most maternal deaths occur in the puerperium and most maternal morbidities probably also arise at that time. Maternal morbidities occur much more frequently than maternal deaths, but very little is known about their magnitude or causes. This study uses focus-group discussions to explore the experiences of childbirth and postpartum illness among rural Bangladeshi women. The women's beliefs about disease causation, and their use of traditional health care, are explored. The significance of the findings for the training of traditional birth attendants and for programs of postpartum care is discussed.
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95
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Mitra J, Chowdhury M. Ca2+ dependent activation of rat uterine glycerylphosphorylcholine diesterase: presence of a positive modulator protein in uterine secretion. Mol Cell Biochem 1994; 139:101-8. [PMID: 7862100 DOI: 10.1007/bf01081732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The rat uterine secretory enzyme glycerylphosphorylcholine (GPC) diesterase (EC 3.1.4.2) had been purified and characterized previously with respect to its mol. wt., size, amino acid, carbohydrate composition and estrogen inducible properties. This enzyme is observed to have exclusive specificity for GPC and exhibits characteristic hyperbolic kinetics with Ca2+ in an ethyleneglycolbis N'N'N'N' tetraacetic acid (EGTA) buffered system. Ca2+ reduces Km of the enzyme for GPC from 0.65 to 0.25 mM. The Km for GPC of the partially purified enzyme is found to be 0.35 mM without addition of calcium which indicates the presence of a positive modulator of the enzyme in this fraction. Based on this rationale, a protein activating factor for the enzyme was isolated from this fraction which has a native size of 18 KD as observed on Sephacryl S-200 chromatography and strikingly stimulates enzyme activity at around 0.55 microM.
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Das M, Mukhopadhyay PK, Chowdhury M. Carbohydrate-binding profile of a pregnancy-associated rat uterine glycoprotein. Mol Cell Biochem 1994; 137:91-9. [PMID: 7845392 DOI: 10.1007/bf00944070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Sugar-binding proteins obtained from the peri-implantation uterine tissue have been thought in recent years to have significant roles in embryo implantation, where carbohydrate moieties of the protein are actively involved. Based on this rationale a mannose-containing glycoprotein/lectin (named uterine agglutinin or UA) was purified by Concanavalin A (Con A) affinity chromatography in a previous study. A modification of the original purification procedure to include a 33% ammonium sulfate fractionation improves the yield of the protein significantly. An alternative purification procedure by Mannan affinity matrix, indicates that apart from containing mannose, UA possesses mannose-binding properties as well. In this paper, we report some of the biochemical and more specifically, the carbohydrate-binding characteristics of UA. The protein is seen to contain mannose-6-phosphate (M-6-P)-binding sites, which is of importance since M-6-P receptors have a large number of biologically significant roles, including that of binding to growth factors. SDS-PAGE, gel filtration chromatography and alkaline PAGE indicate the homogenous nature of the protein with subunit molecular weights of 36 kDa and 19 kDa, and a native size of 64 kDa. Amino acid analysis shows glycine, glutamic acid and aspartic acid to be the major constituents. UA is a glycoprotein and shows presence of N-acetyl glucosamine and galactose, apart from mannose. De nove synthesis studies in the presence of tunicamycin show that the carbohydrate moiety of the glycoprotein is attached by N-linkage to the protein. Binding characteristics of the protein is studied quantitatively in which (125I)-labelled lectin is bound to Mannan-Sepharose affinity matrix.(ABSTRACT TRUNCATED AT 250 WORDS)
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97
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Banerjee M, Chowdhury M. Purification and characterization of a sperm-binding glycoprotein from human endometrium. Hum Reprod 1994; 9:1497-504. [PMID: 7989512 DOI: 10.1093/oxfordjournals.humrep.a138737] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A sialic-acid-binding protein (SABP) was purified to apparent homogeneity from human endometrial scrapings taken at various stages of the menstrual cycle from normal cycling females. The 54 kDa monomer was found to be an O-linked glycoprotein with a total carbohydrate content of 34%. This protein agglutinated washed 2% v/v rabbit red blood cells (RBC) in the presence of calcium. Amongst sialic acids and sialoglycoproteins tested for haemagglutination inhibitory activities, N-glycolyl neuraminic acids and human alpha 1-acid glycoprotein were found to be the most potent, the agglutination activity being totally abolished on desialylation of the RBC in the presence of neuraminidase. Western blot studies showed it to be present in the uterine fluid but absent in normal female serum and in full-term placenta. It was also absent in endometrial homogenates of some cases of unexplained primary infertility. Specific binding studies and Scatchard analysis revealed that 125I-labelled human SABP ligand can bind to human spermatozoa with a Ka = 2.6 x 10(9) M-1, their receptors probably being glycoconjugates having a terminal sialic acid moiety, since the sperm-protein interaction could also be abolished when spermatozoa were desialylated with neuraminidase. The binding occurred specifically on the sperm head plasma membrane and decreased markedly when spermatozoa were previously capacitated in vitro using human serum albumin, implicating the possible loss of a sialoglycoprotein receptor to which the ligand binds during capacitation. The biological importance of this sperm-binding secretory glycoprotein and its functional significance in human reproduction have been discussed.
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98
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Sen G, Chowdhury M, Mandal C. O-acetylated sialic acid as a distinct marker for differentiation between several leukemia erythrocytes. Mol Cell Biochem 1994; 136:65-70. [PMID: 7854333 DOI: 10.1007/bf00931606] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
AchatininH (ATNH) is a lectin, isolated from the hemolymph of Achatina fulica snail, which has been shown to have narrow specificity towards 9-O-acetyl sialic acid. Usually ATNH does not agglutinate normal human erythrocytes, however, it is capable of agglutinating erythrocytes of patients suffering from acute lymphocytic and acute myelogenous leukemia. Determination of binding constants, numbers of binding sites and lectin overlay experiments using patients' erythrocytes ghost, have suggested that some alterations in erythrocyte cell surface sialoglycoproteins or more precisely appearance of some O-acetylated sialoglycoprotein as a result of pathological transformations has caused this change in the binding of ATNH.
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99
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100
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Mitra J, Chowdhury M. Association of glycerylphosphorylcholine with human sperm and effect of capacitation on their metabolism. Reprod Fertil Dev 1994; 6:679-85. [PMID: 7624507 DOI: 10.1071/rd9940679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The presence and localization of glycerylphosphorylcholine (GPC) on the surface of human sperm, as well as the metabolism of its breakdown product L-glycerol 3 phosphate (G3P), were investigated. GPC was found to be associated with sperm after penetrating cervical mucus and was present after repeated washing of the sperm. GPC was partially released by treatment with 0.4 M NaCl in 0.01 M sodium phosphate buffer (pH 7.4) and localized to the head region after sperm fractionation. G3P did not increase O2 uptake of uncapacitated human sperm. However, under aerobic conditions, lactate accumulated when exogenous G3P or uterine GPC diesterase was added to sperm in suspension. The uptake of O2 by washed capacitated sperm pre-incubated with 1 unit of rat uterine GPC diesterase for 30 min was significant. This effect was inhibited by 2 microM oligomycin indicating that oxidative phosphorylation had occurred. The present study indicates that GPC may play a role in the metabolism of human sperm after capacitation.
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