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Biomedical subjects

J Chakraborty

Publications and source records attributed to J Chakraborty.

At least 19 recordsLinked to original sources

Low nutrient intakes among infants in rural Bangladesh are attributable to low intake and micronutrient density of complementary foods.

We assessed the adequacy of nutrient intakes of 135 rural Bangladeshi breast-fed infants 6-12 mo of age and examined nutritional trade-offs due to possible displacement of breast milk by complementary foods. Observers completed 12-h daytime measurements of breast milk and complementary food intakes; data for the previous 12 h were obtained from maternal recall, yielding estimates of total 24-h intakes. On average, infants were mildly wasted (mean +/- SD weight-for-length Z-score = -0.92 +/- 0.88) and moderately stunted (length-for-age Z-score = -1.49 +/- 0.96). Total energy intakes at 6-8 and 9-12 mo were 88 and 86% of absolute energy requirements (kJ/d), 106 and 105% of requirements per kg body weight, and 97 and 94% of requirements per kg median weight-for-length, respectively. Breast milk contributed 78% of energy intake at 6-8 mo and 75% at 9-12 mo. Mean meal frequency and energy density of complementary foods were generally consistent with recommendations, but only small amounts of food were offered. Nevertheless, only 72% of the food energy offered was consumed. Total energy intake was positively correlated with meal frequency, quantity consumed per meal, and energy intake from breast milk, but not with energy density of complementary foods. Energy intake from complementary foods was inversely related to energy intake from breast milk. The diets fell short of recommended intakes for numerous vitamins and minerals. We conclude that although greater intakes of complementary foods were associated with higher total energy intake, micronutrient intake remained low due to the low micronutrient density of the complementary foods consumed and the partial displacement of breast milk.

Bangladesh↗

Behavior-change trials to assess the feasibility of improving complementary feeding practices and micronutrient intake of infants in rural Bangladesh.

This study used simple rapid-assessment techniques to test the feasibility of increasing the consumption of complementary foods by infants by asking mothers to increase meal quantity or frequency or by altering the viscosity/energy density of the food. The feasibility of using micronutrient supplements either added directly to food or administered as liquid drops was also examined. The study was conducted in rural Bangladesh and involved four separate short-term behavioral change trials. Depending on the trial, fieldworkers recruited 30 to 45 infants 6 to 12 months of age. Following recommendations to increase the amount of food provided to infants, the mean intakes from single meals increased from 40 +/- 23 g on day 1 to 64 +/- 30 g on day 7 (p < 0.05). In a second trial, the mean meal frequency increased from 2.2 +/- 1.3 on day 1 to 4.1 +/- 1.3 on day 7 (p < 0.05). Provision of high-energy-density diets, prepared by decreasing viscosity with alpha-amylase or by hand-mashing rice and dhal into a paste before feeding, increased single-meal energy consumption from 54 +/- 35 kcal to 79 +/- 52 kcal or 75 +/- 37 kcal (p < 0.05), respectively. Both types of micronutrient supplements were well accepted and used according to recommendations. In conclusion, it was possible to change short-term child-feeding behaviors to promote increased food intake, mealfrequency, energy density, and micronutrient consumption. Because each of these interventions lasted for only about 1 week, however, the long-term sustainability of these changes is not known. Moreover, the effect of increased feeding of complementary foods on intakes of breastmilk and total daily consumption of energy and nutrients requires further study.

Bangladesh↗

Reduction of cholera in Bangladeshi villages by simple filtration.

Based on results of ecological studies demonstrating that Vibrio cholerae, the etiological agent of epidemic cholera, is commensal to zooplankton, notably copepods, a simple filtration procedure was developed whereby zooplankton, most phytoplankton, and particulates >20 microm were removed from water before use. Effective deployment of this filtration procedure, from September 1999 through July 2002 in 65 villages of rural Bangladesh, of which the total population for the entire study comprised approximately 133,000 individuals, yielded a 48% reduction in cholera (P < 0.005) compared with the control.

Animals↗

Children's fluid intake during diarrhoea: a comparison of questionnaire responses with data from observations.

UNLABELLED: Many of the individual questions used by the World Health Organization for household surveys on diarrhoea management have not been systematically assessed. This study assessed the use of simple questions to caretakers of children to estimate the proportion of young children who received increased quantities of fluids during diarrhoeal episodes by comparing caretakers' responses with data obtained by direct observations. Children aged 4-35 mo (n = 215) with diarrhoea starting within the last 24 h were observed for 12 h. These children were observed for 12 h again 2 wk later, when healthy. On the following day the questionnaire was administered to the caretakers. The observation focused on the frequency of feeding episodes, including breastfeeding and the type and quantity of fluids consumed by the child. The same questionnaire was administered to the caretakers of another group of children (n = 421) with diarrhoea in the past 2 wk. The mean number of feedings (6.0 +/- 3.8 vs 5.0 +/- 3.5), breastfeeding episodes (11.2 +/- 3.6 vs 8.4 +/- 3.3), breastfeeding duration (85.8 +/- 36.3 min vs 49.1 +/- 22.8 min), other fluid intake (345.8 +/- 309.6 ml vs 120.9 +/- 136.4 ml) and total fluid consumption (653.9 +/- 240.4 ml vs 399.5 +/- 133.6 ml) were significantly higher (p < 0.0001) during diarrhoea compared with healthy periods. At the population level, the simple questionnaire administered to caretakers was found to have high agreement between the reported increase in fluid consumption and the actual increase in fluid intake (defined as > or = 100 ml). At the individual level, caretakers' questionnaire responses for detecting increased fluid intake were highly sensitive (84.3%), but specificity (36.4%) and agreement (0.22) were low. CONCLUSION: This study documents that children had higher fluid intake, which included both breast milk and other fluid, during acute episodes of diarrhoea. Further research is warranted to improve the specificity and agreement of caretakers' responses to simple questions regarding change in fluid intake during diarrhoeal episodes.

Breast Feeding↗

Tsl and LP-BM5: a comparison of two murine retrovirus models for HIV.

The ts1 murine leukemia virus produces an immunodeficiency state in mice that parallels human immunodeficiency virus (HIV) infection in humans. Other murine leukemia viruses, such as LP-BM5 used in the murine acquired immune deficiency virus (MAIDS) model, have been studied extensively as a small animal model for HIV research, but lack many key similarities to HIV. Mice infected with ts1, however, utilize CD4 target cells for infection, undergo neuronal loss and demyelination, and develop clinical immunodeficiency. These features make this retrovirus in many ways an ideal candidate for a small animal model for HIV research. In this review article, the early development, the molecular and clinical pathogenesis of both the ts1 mutant of the Moloney murine leukemia virus and LP-BM5 are examined. Based on an extensive evaluation of the literature on LP-BM5 and ts1, it is concluded that the ts1 virus may serve as a better animal model to human retrovirus infection.

Amino Acid Sequence↗

Safety and immunogenicity of tetravalent rhesus-based rotavirus vaccine in Bangladesh.

BACKGROUND: Rotavirus is the most common cause of severe gastroenteritis among children worldwide. OBJECTIVES: To compare the safety, immunogenicity and shedding patterns of rhesus rotavirus (RRV)-tetravalent vaccine vs. placebo among infants in rural Bangladesh. METHODS: A double blinded, placebo-controlled trial was conducted in which infants (n = 120) were randomly assigned to receive three doses of either vaccine or placebo administered at approximately 6, 10 and 14 weeks of age together with routine immunizations. Data on possible adverse effects of vaccinations were collected daily for 7 days after each dose. Stool samples were collected after each dose, and serum samples were obtained before the first and after the third vaccination. RESULTS: Fever (> or = 38 degrees C), as measured by study assistants, was noted more frequently among vaccinees (15%) than among placebo recipients (2%) during the 7 days after vaccination but was not reported more frequently by parents of vaccinees vs. placebo recipients. Overall 87% of vaccinees had an antibody response (measured by IgA or anti-RRV-neutralizing antibodies) after vaccination compared with 32% of placebo recipients. Rates of seroconversion were higher among subjects with lower levels of prevaccination antibodies and those who shed rotavirus after vaccination. Vaccine strain viruses were detected in stools from placebo vaccine recipients who had evidence of IgA seroconversion. CONCLUSIONS: In this population RRV-tetravalent vaccine was comparably immunogenic and safe as in trials conducted in developed countries, where this vaccine has been proved effective in preventing severe rotavirus diarrhea. These data support continued evaluation of rotavirus vaccines in developing countries.

Antibodies, Viral↗

Acute exposure to extremely hazardous substances: an analysis of environmental equity.

Although environmental equity research has focused primarily on chronic pollution sources, recent advances in environmental modeling and geographic information systems (GIS) provide a foundation for developing measures that can be used to evaluate differential exposure to acute pollution events. This article describes a methodology that uses facility-specific information to develop a risk surface representing the spatial distribution of accidental exposure to hazardous substances in a study area. Environmental pollution models recommended by the U.S. Environmental Protection Agency were used in conjunction with GIS software to achieve this objective. The methodology was implemented in a large metropolitan region (Hillsborough County, Florida) to examine disproportionate exposure to worst-case releases of extremely hazardous substances. The environmental inequity hypothesis was investigated by directly comparing the distribution of potential exposures within each racial (non-White versus White) and income (below poverty versus above poverty) subgroup. The results indicate that a significantly large proportion of both non-White and impoverished individuals resided in areas potentially exposed to multiple accidental releases.

Environmental Exposure↗

Chemopreventive activity of quercetin during carcinogenesis in cervix uteri in mice.

The chemopreventive action of quercetin was examined during 20-methyl cholanthrene induced cervical neoplasia in virgin Swiss albino mice. The effects were evaluated on the basis of histopathological observation of the cervical epithelium, micronucleus frequency in vaginal exfoliated cells and some biochemical parameters in the host liver. Quercetin was found to arrest or reverse the progression of cervical neoplasia. The micronucleus frequency was reduced following its administration. The potential anti-carcinogenic effect of quercetin noted in this study is attributed to its antioxidant property which was reflected in the lipid peroxides and their role in the host detoxification system, as expressed in liver glutathione level, glutathione-S-transferase, glutathione peroxidase, catalase and superoxide dismutase activity. As an integral part of the diet quercetin may offer protection to the epithelium from the damaging effects of carcinogenic chemicals.

Animals↗

Development of a simple sperm cryopreservation model using a chemically defined medium and goat cauda epididymal spermatozoa.

This investigation was carried out to develop a simple sperm cryopreservation model using a chemically defined synthetic medium (modified Ringer's solution) and mature goat cauda epididymal sperm as the model system. Rates of cooling, freezing, and maximum freezing temperature were manipulated with the help of a computer-controlled programmable biofreezer. Highly motile goat cauda sperm dispersed in a modified Ringer's solution was subjected to the freezing protocol: cooling 0.25 degrees C min(-1) to 5 degrees C, 5 degrees C min (-1) to -20 degrees C, 20 degrees C min(-1) to -100 degrees C, prior to plunging into liquid nitrogen. In the absence of any cryoprotective agent, all of the spermatozoa lost their motility. Addition of glycerol (0.22 to 0.87 M) caused a dose-dependent increase of sperm motility recovery. The highest recovery of forward and total motility was (32 and 35%, respectively) at 0.87 M. Further increase of the glycerol concentration caused a marked decrease in motility. Changes in the cooling rate particularly before and during freezing had a notable effect on the sperm motility recovery. There was no or low recovery (0-18%) of sperm motility when the cells were transferred directly to liquid nitrogen from the initial two cooling stages. The data demonstrate the importance of all of the cooling stages in the cryopreservation of the cells. Like glycerol, dimethyl sulfoxide (Me(2)SO) and ethylene glycol also showed a dose-dependent increase in motility recovery as well as a biphasic curve of cryoprotection. At optimal concentrations, dimethyl sulfoxide (1.00 M) and ethylene glycol (1.29 M) were effective in recovering sperm motility to the extent of 20 and 13%, respectively. Thus these reagents have markedly lower cryoprotection potential than glycerol.

Animals↗

Prenatal screening in rural Bangladesh: from prediction to care.

The role of antenatal care is being increasingly questioned, particularly in resource poor environments. The low predictability of antenatal markers for adverse maternal outcomes has led some to reject antenatal care as an efficient strategy in the fight against maternal and perinatal mortality. Few studies, however, have assessed the predictability of adverse outcomes other than dystocia or perinatal death, and most studies have been hospital based. This population-based cohort study was undertaken to assess whether prenatal screening can identify women at risk of severe labour or delivery complications in a rural area in Bangladesh. Antenatal risk markers, signs and symptoms were assessed for their association with severe maternal complications including dystocia, malpresentation, haemorrhage, hypertensive diseases, twin delivery and death. The results of the study suggest that antenatal screening by trained midwives fails to adequately distinguish women who will need special care during labour and delivery from those who will not need such care. The large majority of the women with dystocia or haemorrhage had no warning signs during pregnancy. A single blood pressure measurement and the assessment of fundal height, on the other hand, may detect a substantial number of women with hypertensive diseases and twin pregnancies. In addition, women who had an antenatal visit were four times more likely to deliver with a midwife than women who had no antenatal visit. Antenatal care may not be an efficient strategy to identify those most in need for obstetric service delivery, but if promoted in concurrence with effective emergency obstetric care, and delivered in skilled hands, it may become an effective instrument to facilitate better use of emergency obstetric care services.

Adult↗

Effect of ascorbic acid and growth factors on collagen metabolism of flexor retinaculum cells from individuals with and without carpal tunnel syndrome.

The effects of ascorbic acid and various growth factors on the proliferation rate and collagen metabolism were studied in cells from the flexor retinaculum of individuals with carpal tunnel syndrome (FR-CTS) and without carpal tunnel syndrome (FR control) and in human dermal fibroblasts. Ascorbic acid and four growth factors, including basic fibroblast growth factor, transforming growth factor, platelet-derived growth factor, and epidermal growth factors, were used. Ascorbic acid stimulates type I collagen production more in FR control than in FR-CTS. Growth factor treatment resulted in the following responses by the cells: (1) a higher mitogenic response than in the control cells; (2) a higher stimulation of type III collagen production and a lower stimulation of type I collagen production in CTS cells as compared with control cells; and (3) more alpha 2 (I) than alpha 1 (I) collagen production in CTS cells, unlike in control cells. We concluded that cells of the FR from individuals with CTS are physiologically altered.

Adult↗

Lysyl oxidase activity in the cells of flexor retinaculum of individuals with carpal tunnel syndrome.

Lysyl oxidase (LO) is produced by myofibroblast cells in some tissues and can be influenced by transforming growth factor beta 1 (TGF beta 1). Myofibroblast-like cells are present in the flexor reticulum of patients with carpal tunnel syndrome (CTS). The goal of the current study was to determine LO activity and the effects of TGF beta 1 on LO expression in the cells from patients with CTS. Tissues from both hands of five individuals with CTS were used for this study. LO activity with and without TGF beta 1 stimulation was assayed in 7-day cell culture specimens. A significant difference in LO activity among individual patients, but not between right and left hands of the same patient, was observed. There was no correlation between the severity of CTS determined by nerve conduction studies and LO activity. Addition of TGF beta 1 significantly increased LO in all cell lines.

Adult↗

Improved indicators of infant mortality for integrated primary healthcare programmes.

Mortality and fertility rates are decreasing rapidly in many developing countries. It is argued that the indices commonly used as measures of these changes, i.e. infant mortality rate and fertility rate, ignore the interaction between mortality and fertility, and do not reflect their combined impact in lowering overall infant mortality. The paper proposes new indicators of infant mortality, termed fertility-adjusted infant mortality ratio (FIMR), age-specific, fertility-adjusted IMR (AFIMR), and total infant mortality ratio (TIMR) that are more sensitive to rapid demographic changes. These indicators include the combined effects of changes in both fertility and infant mortality rates on overall infant mortality in a region and appear to measure the effects of integrated health programmes better. Further, these conceptualize the mother-infant pair as an appropriate unit with which to monitor mortality, and may be used for guiding allocation of resources intended to lower infant mortality. The application and usefulness of these indicators have been illustrated, using one hypothetical example and empirical data from the maternal-child health and family-planning programme in Matlab, Bangladesh, as well as data from white and black population groups in the U.S.A. The results of these examples demonstrate that the new indicators are more sensitive than traditional measures when describing infant mortality, and may better reflect the perception in infant mortality status in the community.

Adolescent↗

Reproductive-tract infections in women in low-income, low-prevalence situations: assessment of syndromic management in Matlab, Bangladesh.

BACKGROUND: In the control of reproductive-tract infections, including sexually transmitted infections (STIs), in low-income and middle-income countries, WHO recommends syndromic management for individuals with symptoms. This intervention was initially developed in areas where prevalence of such infections is high. We investigated the clinical effectiveness and cost of this approach among a group of women with a low prevalence of infection. METHODS: During a 5-month period, we investigated all women complaining of abnormal vaginal discharge and seeking care at maternal and child health/family-planning centres in Matlab, Bangladesh, for the presence of laboratory-diagnosed reproductive-tract infections and STIs. Syndromic diagnoses made by trained health-care workers were compared with laboratory diagnosis of infection. We then calculated the costs of treating women by means of the recommended WHO algorithm and an adapted algorithm incorporating use of a speculum and simple diagnostic tests. FINDINGS: The prevalence of endogenous infections among 320 women seen was 30%. Cervical infections (Neisseria gonorrhoeae and Chlamydia trachomatis) were found in only three women. The WHO algorithm had a high sensitivity (100%) but a low specificity (zero for bacterial vaginosis, candida, and Trichomonas vaginalis). The speculum-based algorithm had a low sensitivity (between zero and 59%) but a higher specificity (79-97%). Between 36% and 87% of costs would have been spent on uninfected women. INTERPRETATION: The high rate of overtreatment in the population studied carries both financial and social costs--the latter in potentially exposing women misdiagnosed as having an STI to threats of domestic disruption or even violence. We make recommendations for management programmes in areas of low STI prevalence and low income.

Adolescent↗

Breast milk immune factors in Bangladeshi women supplemented postpartum with retinol or beta-carotene.

BACKGROUND: Vitamin A supplementation of mothers postpartum may improve infant health, not only by increasing vitamin A delivery to the infant through breast milk but also by increasing delivery of milk immune factors. Our hypothesis was that postpartum supplementation with vitamin A increases milk concentrations of certain soluble immune factors. DESIGN: In a double-blind trial conducted in Matlab, Bangladesh, women at 1-3 wk postpartum were randomly assigned to receive until 9 mo postpartum 1) a single dose of 60 mg retinol as retinyl palmitate followed by daily placebos (n = 69), 2) daily doses of 7.6 mg beta-carotene (n = 72), or 3) daily placebos (n = 71). Milk samples collected at baseline and 3 mo postpartum were analyzed by enzyme-linked immunosorbent assay for secretory immunoglobulin A, lactoferrin, lysozyme, and interleukin 8; by HPLC for total retinol; and by atomic absorption spectroscopy for sodium and potassium. RESULTS: After mammary epithelial permeability (defined as an elevated Na:K) and baseline immune factor concentrations were controlled for, there were no significant treatment effects on immune factors at 3 mo. Increased mammary permeability was common (25% of women at baseline and 12% at 3 mo) and was associated with higher concentrations of milk immune factors. Low body vitamin A stores at baseline, as assessed by the modified-relative-dose-response test, were associated with a higher Na:K, but neither retinol nor beta-carotene supplementation affected the prevalence of increased mammary permeability. CONCLUSIONS: Postpartum vitamin A supplementation does not increase milk concentrations of immune factors. The causes of increased mammary epithelial permeability in this population require further study.

Bangladesh↗

Maternal vitamin A or beta-carotene supplementation in lactating bangladeshi women benefits mothers and infants but does not prevent subclinical deficiency.

The effects of maternal postpartum vitamin A or beta-carotene supplementation on maternal and infant serum retinol concentrations, modified relative dose-response (MRDR) ratios and breast milk vitamin A concentrations were assessed during a community-based trial in Matlab, Bangladesh. At 1-3 wk postpartum, women were randomly assigned to receive either (1) a single dose of 200,000 international units [60,000 retinol equivalents (RE)] vitamin A followed by daily placebos (n = 74), (2) daily doses of beta-carotene [7.8 mg (1300 RE)] (n = 73) or (3) daily placebos (n = 73) until 9 mo postpartum. Compared to placebos, vitamin A supplementation resulted in lower maternal MRDR ratios (i.e., increased liver stores) and higher milk vitamin A concentrations at 3 mo, but these improvements were not sustained. The beta-carotene supplementation acted more slowly, resulting in milk vitamin A concentrations higher than the placebo group only at 9 mo. Irrespective of treatment group, over 50% of women produced milk with low vitamin A concentrations (</=1.05 micromol/L or </=0.28 micromol/g fat) throughout the study. Overall, mean maternal serum retinol concentrations were not affected by supplementation. Compared to the placebo group, the mean MRDR ratio of 6-mo-old infants was higher in the vitamin A group. Infants (33%) had serum retinol concentrations <0.70 micromol/L and 88% had MRDR ratios >/=0. 06. We conclude that while both interventions were beneficial, neither was sufficient to correct the underlying subclinical vitamin A deficiency in these women nor to bring their infants into adequate vitamin A status.

Adult↗

Effects of environmental factors on child survival in Bangladesh: a case control study.

The need for further studies on relationships between deaths and environmental variables has been reported in the literature. This case-control study was, therefore, carried out to find out the associations between several social and environmental variables and deaths of children due to infectious diseases such as those leading to diarrhoea, acute respiratory infection, measles and other diseases. Six hundred and twenty-five deaths (cases) and an equal number of matched living children (controls) aged 1-59 months, were studied in rural Matlab. An analysis of crude and adjusted odds ratio showed differential associations. Sources of drinking water, amount of stored water, conditions of latrines, number of persons sleeping with the child and the type of cooking site were statistically significantly associated with deaths due to infectious diseases after controlling for breast feeding, immunization, and the family size. Significant associations were also observed between: (i) the sources of drinking water and deaths due to ARI, and (ii) conditions of latrines and deaths due to diarrhoeal diseases, after controlling for the confounding variables. Several other environmental factors also showed associations with these various death groups, but they were not statistically significant. The size of the samples in death groups (small) and the prevalence of more or less homogeneous environmental health conditions probably diminished the magnitude of the effects. The results of the study reconfirm the importance of environmental health intervention in child survival, irrespective of breast-feeding, immunization, and selected social variables.

Bangladesh↗

HIV/AIDS and ocular manifestations.

As of December, 1998, worldwide, 33.4 million people have been infected with human immunodeficiency virus (HIV). A wide variety of ocular disorders is associated with HIV. HIV can affect all structures of the eye. A large number of micro-organisms including virus, bacteria, fungi and protozoa, cause ocular diseases in HIV-infected patients. Out of these, cytomegalovirus (CMV) retinitis is the most common. Ocular tuberculosis (TB), syphilitic retinal diseases and ocular toxoplasmosis are other serious eye problems in HIV patients, especially in the developing countries. HIV can also cause microvascular abnormalities producing cotton-wool spots. Neoplasms and drug-induced ocular disorders may be other problems. Ophthalmologists need to have wide range of information regarding HIV/AIDS for better diagnosis and management of their patients with ocular abnormalities. Further research, data collection, continuing education and the latest information on eye problems of AIDS patients are essential for Indian ophthalmologists.

AIDS-Related Opportunistic Infections↗