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Biomedical subjects

M Khare

Publications and source records attributed to M Khare.

At least 19 recordsLinked to original sources
PubMed2001

The role of ultrasound in the expectant management of early pregnancy loss.

OBJECTIVE: To define the sonographic criteria which best determine the likelihood of successful expectant management of early pregnancy failure (EPF). METHODS: Women with an ultrasound diagnosis of EPF at 7-14 weeks' gestation were offered the option of expectant management or surgical evacuation. RESULTS: Five hundred and forty-five women had a diagnosis of EPF; 298 with incomplete miscarriage and 247 with missed miscarriage or an embryonic pregnancy. A total of 305 women opted for expectant management, with an overall success rate of 86%. The success rate for incomplete miscarriage (96%) was significantly better than that for missed miscarriage (62%). CONCLUSION: This study demonstrates that EPF can be safely managed expectantly. Ultrasound has an invaluable role in predicting the likelihood of successful expectant management enabling patients to make an informed choice about their medical care.

Abortion, Incomplete↗
PubMed2001

Compensating for provider nonresponse using response propensities to form adjustment cells: the National Immunization Survey.

OBJECTIVES: The National Immunization Survey (NIS) uses two phases of data collection to obtain vaccination information from a sample of young children: a random-digit-dialing (RDD) survey for identifying households with children 19-35 months of age, followed by a mail survey for obtaining provider-reported vaccination histories about these children. Provider-reported vaccination histories are used to estimate vaccination coverage rates. In 1998, provider-reported vaccination histories were not obtained for 32.9% of children with a completed RDD interview. This report describes the statistical methods adopted in 1998 to reduce the bias in vaccination coverage estimates that could result from "vaccination history nonresponse," that is, differences between children for whom provider data was obtained and those for whom it was not obtained. METHODS: In the methods adopted in 1998, children with completed NIS RDD interviews are grouped into adjustment cells defined by their propensity to have adequate provider data. Sampling weights of children with adequate provider data are divided by the cell-specific weighted response rate to allow these children to represent all children in the cell. RESULTS: Using an "optimal" number of cells, the overall extent of bias reduction was 0.5%, suggesting that provider nonresponse bias was small. Authoritative literature suggests using five cells. No statistically significant differences were observed in vaccination coverage estimates when comparing estimates based on the "optimal" number of cells with five cells. Thus, five adjustment cells are used to reduce provider nonresponse bias in the NIS vaccination coverage estimates. No substantively important differences were observed between estimates based on the methodology used prior to 1998 and the methodology adopted in 1998.

Algorithms↗
PubMed2000

Food intake patterns and gallbladder disease in Mexican Americans.

OBJECTIVE: Results of previous studies on diet and gallbladder disease (GBD), defined as having gallstones or having had surgery for gallstones, have been inconsistent. This research examined patterns of food intake in Mexican Americans and their associations with GBD. DESIGN: Cross-sectional. SUBJECTS: The study population included 4641 Mexican Americans aged 20-74 years who participated in the 1988-94 third National Health and Nutrition Examination Survey (NHANES III). GBD was diagnosed by ultrasound. Food intake patterns were identified by principal components analysis based on food frequency questionnaire responses. Component scores representing the level of intake of each pattern were categorized into quartiles, and prevalence odds ratios (POR) were estimated relative to the lowest quartile along with 95% confidence intervals (CI). RESULTS: There were four distinct patterns in women (vegetable, high calorie, traditional, fruit) and three in men (vegetable, high calorie, traditional). After age adjustment, none were associated with GBD in women. However, men in the third (POR = 0.42, 95%CI 0.21-0.85) and fourth (POR = 0.53, 95%CI 0.28-1.01) quartiles of the traditional intake pattern were half as likely to have GBD as those in the lowest quartile. CONCLUSIONS: These findings add to a growing literature suggesting dietary intake patterns can provide potentially useful and relevant information on diet-disease associations. Nevertheless, methods to do so require further development and validation.

Adult↗
PubMed2000

Country of birth and prevalence of gallbladder disease in Mexican Americans.

OBJECTIVES: This research sought to describe the association between country of birth and gallbladder disease (GBD) in Mexican Americans, identify subgroups at especially high risk, and identify risk factors that may mediate a birthplace-GBD association. DESIGN: Cross-sectional. METHODS: Our study population included 4157 Mexican Americans aged 20-74 who participated in the 1988-94 third National Health and Nutrition Examination Survey. GBD was diagnosed by ultrasound. Information on country of birth, education, income, and selected GBD risk factors was obtained from interviews. Prevalence odds ratios (POR) for GBD in Mexico- vs. US-born Mexican Americans were estimated by unconditional logistic regression, along with 95% confidence intervals (CI). To evaluate the extent to which GBD risk factors mediated the birthplace-GBD association, PORs for country of birth were compared in models with and without additional covariates. RESULTS: Age-adjusted GBD prevalence was lower in Mexico- than in US-born Mexican-American women (POR = 0.70, 95% CI 0.50, 0.98) and men (POR = 0.63, 95% CI 0.40, 0.97). The difference was especially pronounced among subjects of lower socioeconomic status. Despite substantial differences in GBD risk factor distributions by birthplace, none could completely explain the prevalence difference. CONCLUSIONS: The observation that GBD prevalence is higher among US-born Mexican Americans is consistent with research showing poorer health in this group. Further research is needed to identify strategies for reducing morbidity from GBD in Mexican Americans.

Adult↗
PubMed1999

Prevalence and ethnic differences in gallbladder disease in the United States.

BACKGROUND & AIMS: Gallbladder disease is one of the most common conditions in the United States, but its true prevalence is unknown. A national population-based survey was performed to determine the age, sex, and ethnic distribution of gallbladder disease in the United States. METHODS: The third National Health and Nutrition Examination Survey (NHANES III) conducted gallbladder ultrasonography among a representative U.S. sample of more than 14, 000 persons. The diagnosis of gallbladder disease by detection of gallstones or cholecystectomy was made with excellent reproducibility. RESULTS: An estimated 6.3 million men and 14.2 million women aged 20-74 years had gallbladder disease. Age-standardized prevalence was similar for non-Hispanic white (8. 6%) and Mexican American (8.9%) men, and both were higher than non-Hispanic black men (5.3%). These relationships persisted with multivariate adjustment. Among women, age-adjusted prevalence was highest for Mexican Americans (26.7%) followed by non-Hispanic whites (16.6%) and non-Hispanic blacks (13.9%). Among women, multivariate adjustment reduced the risk of gallbladder disease for both Mexican Americans and non-Hispanic blacks compared with non-Hispanic whites. CONCLUSIONS: More than 20 million persons have gallbladder disease in the United States. Ethnic differences in gallbladder disease prevalence differed according to sex and were only partly explained by known risk factors.

Adult↗
PubMed1998

The current status of methods for estimating the prevalence of human immunodeficiency virus in the United States of America.

The prevalence of human immunodeficiency virus (HIV) infection can be estimated by two distinct methods. One method, back-calculation, is a complex statistical procedure that estimates the HIV epidemic curve. The second method is based on data from population-based surveys, which provide estimates of the proportion of persons infected with HIV within subgroups, and on the known or estimated population totals for these subgroups. Estimates from these methods are subject to substantial uncertainty and bias, both of which are difficult to quantify. We review recent use of these procedures to estimate HIV prevalence in the United States of America. We also summarize new data on the uncertainty and the bias in these estimates. Reliable estimates of HIV prevalence can be made only by synthesizing estimates from several procedures and by a comprehensive evaluation of relevant data. Future estimates of HIV prevalence will require modifications of these methods or the development of new methods.

Adolescent↗
PubMed1998

Influence of ethnic origin on nuchal translucency screening for Down's syndrome.

OBJECTIVE: To determine the influence of ethnic origin on access to and equity of nuchal translucency screening for Down's syndrome in a multiethnic population. DESIGN: An observational study in a district general hospital with a large multiethnic population. SUBJECTS: 1944 women attending at a hospital antenatal clinic. MAIN OUTCOME MEASURES: First-trimester fetal nuchal translucency measurements at 10-14 weeks in women from different ethnic groups. RESULTS: The racial origin of the screened population was not significantly different from that of the population attending for initial antenatal examination. Multiple regression analysis showed a small but significant difference in nuchal translucency measurement between fetuses of different ethnic origin. CONCLUSION: Nuchal translucency screening can be effectively and equitably delivered to a multiethnic population. Although there are significant differences in nuchal translucency measurement between ethnic groups, these differences are too small to require correction when nuchal translucency is used to screen for Down's syndrome.

Asian People↗
PubMed1997

Update on the seroepidemiology of human immunodeficiency virus in the United States household population: NHANES III, 1988-1994.

To update the estimate of seroprevalence of HIV from the third National Health and Nutrition Examination Survey (NHANES III), data from the second phase of the survey were combined with previously published data to produce a more precise estimate. The testing was performed anonymously on 11,203 individuals 18-59 years of age examined from 1988 to 1994. Fifty-nine individuals were HIV positive, for an overall prevalence of 0.32%. The number of individuals living in households with HIV infection based on this estimate was 461,000, with a 95% confidence interval of 290,000-733,000. Analysis of nonresponse demonstrated that white and black men 40-59 years of age were least likely to participate in the survey. A sensitivity analysis demonstrated that this nonresponse may have biased the NHANES III estimate downward by 190,000 persons. Data from the second phase of the survey were used to analyze the association between drug use and HIV infection. Black women who used cocaine were 12 times more likely to be HIV positive compared with all tested black women (6.5% vs. 0.55%). This survey provides an estimate of HIV prevalence for individuals who reside in households but excludes some persons who are at higher risk for HIV infection, including prisoners and the homeless not residing in shelters.

Adolescent↗
PubMed1997

Internalization of dengue virus-induced suppressor cytokine during transmission of the suppressor signal via macrophage.

In dengue type 2 virus (DV)-induced suppressor T cell cascade TS1 cells secrete a suppressor cytokine (SF) which acts via syngeneic macrophages (M phi) to recruit TS2 cells. SF binds to both high and low affinity receptors (SF-R) on M phi. In the present study the fate of SF in M phi during transmission of suppressor signal is investigated. It was observed that SF bound to high affinity receptors internalized through receptor mediated endocytosis. This was inhibited by pretreatment of M phi with anti-SF-R-antiserum and didansylcadaverine, a potent inhibitor of endocytosis. Internalized SF was degraded by lysosomal activity as shown by inhibition of suppressor activity by pretreatment of M phi with monensin and NH4Cl. Degraded SF was transported to a site other than SF-R on M phi membrane for recruitment of TS2 cells. This was inhibited by anti-SF-antiserum. Transmission of suppressor signal is inhibited if M phi are treated first with H-2K-mAb and then with SF (shown earlier) but when M phi were treated first with SF and after 1 hr with H-2K-monoclonal antibody, the inhibition did not occur. As SF requires binding to H-2K and SF-R for mediation of suppression, the binding of H-2K occurred with degraded SF within the cell. Thus SF is internalized, degraded and binds to H-2K antigen before its recognition by native T cells.

Animals↗
PubMed1997

Role of nitric oxide in transmission of dengue virus specific suppressor signal.

Production of NO2- was maximum when peritoneal M phi was incubated with SF (40 mg) for 45 min. Pretreatment of M phi with anti-SF-antisera inhibited production of NO2- Pretreatment of M phi with NG monomethyl L-arginine (L-NMA) or arginase, an inhibitor of L-arginine dependent pathway, inhibited production of NO2- and transmission of suppressor signal in a dose-dependent manner. This indicates that NO and Ca2+ serve as intracellular signal in transmission of DV-induced suppressor signal.

Animals↗
PubMed1996

Prevalence of HIV infection in the United States, 1984 to 1992.

OBJECTIVE: To estimate the number of persons infected with the human immunodeficiency virus (HIV) living in the United States and the change in HIV infection prevalence since 1984. DESIGN: We estimated HIV prevalence from 3 data sources. We estimated past HIV infection rates from a statistical procedure based on national acquired immunodeficiency syndrome (AIDS) case surveillance data and estimates of the time from HIV infection to AIDS diagnosis. We also analyzed HIV prevalence data from 2 national surveys, a survey of childbearing woman and a household survey of current health status. We used other data sources to adjust these survey estimates to include groups not covered in the surveys. RESULTS: Approximately 0.3% of US residents (650,000-900,000 persons) were infected with HIV in 1992. Approximately 0.6% of men (including adolescent boys > or = 13 years of age) were infected, including approximately 2% of non-Hispanic black men and 1% of Hispanic men. Approximately 0.1% of women (including adolescent girls > or = 13 years of age) were infected, including approximately 0.6% of non-Hispanic black women. Approximately half of all infected persons were men who had sex with men, and one fourth were injecting drug users. The prevalence of HIV infection increased from 1984 to 1992, with a greater relative increase among women than men. CONCLUSIONS: The 3 different data sources and methods are consistent in estimating that 650,000 to 900,000 persons were infected with HIV in the United States in 1992. Among adolescents and adults of both sexes, the proportion infected was substantially higher among non-Hispanic blacks and Hispanics than among non-Hispanic whites. HIV-related illness will be a major clinical and public health problem in the United States for years to come.

Adolescent↗
PubMed1995

Transmission of dengue virus-specific suppressor signal depends on the presence of calcium.

The present study was undertaken to investigate the role of calcium in the production of dengue type 2 virus (DV) induced suppressor cytokine (SF) and in transmission of the suppressor signal via syngeneic macrophage (M phi) to recruit the second subpopulation of suppressor T(TS2) cell. Effect of calcium channel blocking drugs, Verapamil and Nifedipine, on the production and activity of SF was investigated. The production of SF was inhibited in a dose dependent manner by the calcium channel blockers. The suppressor activity of SF was also inhibited by calcium channel blocking drugs. SF could not be produced when spleen cells were cultured in a calcium free medium, the production being restored on substitution with calcium chloride. Treatment of M phi with the calcium channel blockers inhibited the transmission of the suppressor signal from TS1 to TS2 cells in a dose dependent manner. The influx of calcium during transmission of the suppressor signal was studied by measuring the 45Ca uptake. Calcium channel blocking drugs inhibited the 45Ca uptake by T lymphocytes. Thus, presence of calcium is obligatory for the production and suppressor activity of SF and it plays a critical role in transmission of the suppressor signal.

Animals↗
PubMed1994

The seroepidemiology of human immunodeficiency virus in the United States household population: NHANES III, 1988-1991.

To provide an estimate of the seroprevalence of human immunodeficiency virus (HIV) in a representative sample of the U.S. household population, serum samples from participants in the third National Health and Nutrition Examination Survey (NHANES III) were tested for HIV antibody. The testing was performed anonymously on 5,430 individuals 18-59 years old from phase 1 of NHANES III conducted from 1988 to 1991. Twenty-nine individuals were HIV positive. The total weighted prevalence was 0.39%. The population estimate of infected individuals was 547,000, with a 95% confidence interval of 299,000-1,020,000 infected persons. Black participants were four times more likely to be HIV positive than white/other individuals and three times more likely than Mexican Americans. Men were three times more likely to be infected than women. Higher nonresponse to the survey and to phlebotomy was observed in young white men; therefore these data provide a conservative estimate of HIV infection in the general household population. This estimate does not include individuals who do not live in households and who may be at higher risk of infection, such as persons in penal institutions, the homeless, or certain hospitalized patients.

Adult↗
PubMed1990

Poisoning in children--analysis of 250 cases.

This study is an analysis of 250 cases over a period of 2 years, admitted to our hospital for various poisonings. The total incidence of poisoning was 11.9%, much higher as compared to the other series. Of these, 58.4% were seen in the age group of 1-4 years. Male to female ratio was 1.7:1. Incidence of food poisoning was 48.8% followed by that of kerosene (24%), pesticides (9.6%), chemicals and medicaments (8.4%), plant (3.6%) and animal bites (3.2%). Overall mortality was 0.8%.

Age Factors↗