Biomedical subjects

Abhik Das

Publications and source records attributed to Abhik Das.

14 recordsLinked to original sources

PubMed2006

Fetal origin of childhood disease: intrauterine growth restriction in term infants and risk for hypertension at 6 years of age.

OBJECTIVE: To examine the association between intrauterine growth restriction (IUGR) status at birth among full-term infants, exposure to substance use during pregnancy, and risk of hypertension at 6 years of age. DESIGN: Prospective evaluation of high-risk children. SETTING: Four centers of the National Institute of Child Health and Human Development Neonatal Research Network. PARTICIPANTS: One thousand three hundred eighty-eight infants (600 cocaine exposed, 781 nonexposed, and 7 indeterminate, matched by gestational age, race, and sex), were enrolled at these sites. Nine hundred fifty children (415 exposed, 535 nonexposed) were followed up for 6 years. Intervention Right arm blood pressure was measured using the Dinamap portable adult/pediatric monitor with appropriate cuff size. Main Outcome Measure Blood pressure levels. Hypertension was defined as either systolic or diastolic blood pressure higher than the 95th percentile for sex, age, and height. RESULTS: Eight hundred ninety-one children had blood pressure data at 6 years of age: 516 were born at full term; 144 (28%) of the 516 children had a diagnosis of IUGR at birth. At 6 years of age, 93 (19%) of 516 children had hypertension. Of 144 children with IUGR, 35 (24%) had hypertension as compared with 58 (16%) of 372 children without IUGR (P<.05). Twenty percent of cocaine-exposed children had hypertension as compared with 16% of nonexposed children (P = .20). Intrauterine growth restriction status at birth was significantly associated with hypertension (relative risk, 1.8 [95% confidence interval, 1.2-2.7]) when multivariable Poisson regression analysis was performed adjusting for site; maternal race, education, and tobacco, marijuana, alcohol, and cocaine use during pregnancy; and child's current body mass index (calculated as weight in kilograms divided by height in meters squared). CONCLUSION: In term infants, IUGR is linked to risk of hypertension in early childhood, which may be a marker for adult cardiovascular disease.

Adult↗

PubMed2006

Predicting outcomes of neonates diagnosed with hypoxemic-ischemic encephalopathy.

OBJECTIVE: The goals were to identify predictor variables and to develop scoring systems and classification trees to predict death/disability or death in infants with hypoxic-ischemic encephalopathy. METHODS: Secondary analysis of data from the multicenter, randomized, controlled, National Institute of Child Health and Human Development Neonatal Research Network trial of hypothermia in hypoxic-ischemic encephalopathy was performed. Data for 205 neonates diagnosed as having hypoxic-ischemic encephalopathy were studied. Logistic regression analysis was performed by using clinical and laboratory variables available within 6 hours of birth, with death or moderate/severe disability at 18 to 22 months or death as the outcomes. By using the identified variables and odds ratios, scoring systems to predict death/disability or death were developed, weighting each predictor in proportion to its odds ratio. In addition, classification and regression tree analysis was performed, with recursive partitioning and automatic selection of optimal cutoff points for variables. Correct classification rates for the scoring systems, classification and regression tree models, and early neurologic examination were compared. RESULTS: Correct classification rates were 78% for death/disability and 71% for death with the scoring systems, 80% and 77%, respectively, with the classification and regression tree models, and 67% and 73% with severe encephalopathy in early neurologic examination. Correct classification rates were similar in the hypothermia and control groups. CONCLUSIONS: Among neonates diagnosed as having hypoxic-ischemic encephalopathy, the classification and regression tree model, but not the scoring system, was superior to early neurologic examination in predicting death/disability. The 3 models were comparable in predicting death. Only a few components of the early neurologic examination were associated with poor outcomes. These scoring systems and classification trees, if validated, may help in assessments of prognosis and may prove useful for risk-stratification of infants with hypoxic-ischemic encephalopathy for clinical trials.

Algorithms↗

PubMed2005

Neurocognitive skills moderate urban male adolescents' responses to preventive intervention materials.

The present experiment was designed to determine whether individual variation in neurobiological mechanisms associated with substance abuse risk moderated effects of a brief preventive intervention on social competency skills. This study was conducted in collaboration with the ongoing preventive intervention study at Johns Hopkins University Prevention Intervention Research Center (JHU PIRC) within the Baltimore City Public Schools. A subsample (N = 120) of male 9th grade students was recruited from the larger JHU study population. Approximately half of the participants had a current or lifetime diagnosis of CD while the other half had no diagnosis of CD or other reported problem behaviors. Measures of executive cognitive function (ECF), emotional perception and intelligence were administered. In a later session, participants were randomly assigned to either an experimental or control group. The experimental group underwent a facilitated session using excerpted materials from a model preventive intervention, Positive Adolescent Choices Training (PACT), and controls received no intervention. Outcomes (i.e., social competency skills) were assessed using virtual reality vignettes involving behavioral choices as well as three social cognition questionnaires. Poor cognitive and emotional performance and a diagnosis of CD predicted less favorable change in social competency skills in response to the prevention curriculum. This study provides evidence for the moderating effects of neurocognitive and emotional regulatory functions on ability of urban male youth to respond to preventive intervention materials.

Adolescent↗

PubMed2005

Low birth weight and preterm births: etiologic fraction attributable to prenatal drug exposure.

OBJECTIVES: To determine the factors that would increase the likelihood of outcomes: low birth weight (LBW), preterm births and intrauterine growth restriction (IUGR). STUDY DESIGN: Secondary data analysis from a multi-center study. Risk factors for each outcome were derived from logistic regression models. Odds ratios (OR), 95% confidence intervals, and population-attributable risk proportions (PAR%) were estimated. RESULTS: Prenatal cocaine exposure increased the likelihood of LBW (OR: 3.59), prematurity (OR: 1.25), and IUGR (OR: 2.24). Tobacco, but not marijuana, significantly influenced these outcomes. Alcohol had an effect on LBW and IUGR. Etiologic fractions (PAR%) attributable to tobacco for LBW, prematurity, and IUGR were 5.57, 3.66, and 13.79%, respectively. With additional drug exposure including cocaine, estimated summary PAR% increased to 7.20% (LBW), 5.68% (prematurity), and 17.96% (IUGR). CONCLUSION: Disease burden for each outcome increases with each added drug exposure; however, etiologic fraction attributable to tobacco is greater than for cocaine.

Cocaine↗

PubMed2004

A repeated measures approach for simultaneous modeling of multiple neurobehavioral outcomes in newborns exposed to cocaine in utero.

Multiple binary outcomes are encountered frequently in epidemiologic research. This work was motivated by the Maternal Lifestyle Study, 1993-1995, where newborns exposed prenatally to cocaine and a comparison cohort were examined for the presence of central and autonomic nervous system (CNS/ANS) signs. Thus, each infant contributed to multiple, possibly interrelated, binary outcomes that may collectively constitute one syndrome (even though specific outcomes that are affected by cocaine are of scientific interest). Because it is neither scientifically appropriate nor statistically efficient to fit separate models for each outcome, here we adopt a multivariate repeated measures approach to simultaneously model all the CNS/ANS outcomes as a function of cocaine exposure and other covariates. This formulation has a number of advantages. First, it implicitly recognizes that all the CNS/ANS outcomes may together constitute one syndrome. Second, simultaneous modeling boosts statistical efficiency by allowing for correlations among the outcomes, and it avoids multiple comparisons. Third, it allows for outcome-specific exposure effects, so that the specific signs that are affected by cocaine exposure can be identified.

Bias↗

PubMed2004

The maternal lifestyle study: cognitive, motor, and behavioral outcomes of cocaine-exposed and opiate-exposed infants through three years of age.

OBJECTIVE: To evaluate the direct effects of prenatal cocaine exposure and prenatal opiate exposure on infant mental, motor, and behavioral outcomes longitudinally between 1 and 3 years old. METHODS: As part of a prospective, longitudinal, multisite study, the Bayley Scales of Infant Development II were administered to 1227 infants who were exposed to cocaine (n = 474), opiates (n = 50), cocaine and opiates (n = 48), and neither substance (n = 655) at 1, 2, and 3 years of corrected age by certified, masked examiners. Hierarchic linear modeling of the 1-, 2-, and 3-year scores was conducted using cocaine and opiate exposure as predictors with and without controlling for covariates. RESULTS: Overall retention was 88.4% and did not differ by cocaine or opiate exposure. Overall (at 1, 2, and 3 years), cocaine-exposed infants scored 1.6 Mental Development Index points below infants who were not exposed to cocaine. Opiate-exposed infants scored 3.8 Psychomotor Development Index points below infants who were not exposed to opiates. Neither the cocaine nor the opiate effect remained significant after controlling for covariates. Neither cocaine nor opiate exposure was associated with the Behavioral Record Score during the examination. Low birth weight and indices of nonoptimal caregiving were associated with lower Mental Development Index, Psychomotor Development Index, and Behavioral Record Score scores for all groups of infants. CONCLUSIONS: In the largest at-risk sample observed longitudinally to date, infant prenatal exposure to cocaine and to opiates was not associated with mental, motor, or behavioral deficits after controlling for birth weight and environmental risks.

Child Behavior↗

PubMed2004

Association between patterns of maternal substance use and infant birth weight, length, and head circumference.

OBJECTIVE: To determine the effects of patterns of drug use during term pregnancy on infant growth parameters at birth. METHODS: Histories of cocaine, opiate, alcohol, tobacco, and marijuana use during the 3-month period before pregnancy and the 3 trimesters of pregnancy were recorded at the infants' 1-month visit. Patterns of use were categorized as consistently high, moderate, or low/none or increasing/decreasing, and effects on growth parameters were analyzed in multivariate linear regression analyses, with adjustment for clinical site, maternal age, prepregnancy weight, multidrug use, and socioeconomic status. RESULTS: A total of 241 cocaine-exposed women and 410 non-cocaine-exposed women participated in the study. In the cocaine-exposed group, 75% used alcohol, 90% used tobacco, and 53% used marijuana; in the non-cocaine-exposed group, 57% used alcohol, 34% used tobacco, and 19% used marijuana. Birth weight, birth length, and head circumference were significantly greater among infants born to women who used no drugs, compared with women with any cocaine, opiate, alcohol, tobacco, or marijuana use, and were greater among infants born to cocaine nonusers, compared with cocaine users. With adjustment for confounders, birth weight was significantly affected by cocaine (deficit of 250 g with consistently low pattern) and tobacco (deficits of 232 g with consistently high pattern, 173 g with consistently moderate pattern, 153 g with decreasing pattern, and 103 g with consistently low pattern). Head size was affected by cocaine (deficit of 0.98 cm with consistently moderate pattern) and tobacco (deficits of 0.72 cm with consistently high pattern and 0.89 cm with consistently moderate pattern). Birth length was affected by tobacco use only (deficits of 0.82 cm with consistently high pattern and 0.98 cm with decreasing use). CONCLUSION: Patterns of tobacco use during pregnancy affect birth weight, length, and head circumference, whereas cocaine affects birth weight and head size, when adjustments are made for confounders, including multidrug use.

Birth Weight↗

PubMed2004

Neurodevelopmental outcome and growth at 18 to 22 months' corrected age in extremely low birth weight infants treated with early erythropoietin and iron.

BACKGROUND: Clinical trials evaluating the use of erythropoietin (Epo) have demonstrated a limited reduction in transfusions; however, long-term developmental follow-up data are scarce. OBJECTIVE: We compared anthropometric measurements, postdischarge events, need for transfusions, and developmental outcomes at 18 to 22 months' corrected age in extremely low birth weight (ELBW) infants treated with early Epo and supplemental iron therapy with that of placebo/control infants treated with supplemental iron alone. METHODS: The National Institute of Child Health and Human Development Neonatal Research Network completed a randomized, controlled trial of early Epo and iron therapy in preterm infants < or =1250 g. A total of 172 ELBW (< or =1000-g birth weight) infants were enrolled (87 Epo and 85 placebo/control). Of the 72 Epo-treated and 70 placebo/control ELBW infants surviving to discharge, follow-up data (growth, development, rehospitalization, transfusions) at 18 to 22 months' corrected age were collected on 51 of 72 Epo-treated infants (71%) and 51 of 70 placebo/controls (73%) by certified examiners masked to the treatment group. Statistical significance was determined using chi2 analysis. RESULTS: There were no significant differences between treatment groups in weight or length or in the percentage of infants weighing <10th percentile either at the time of discharge or at follow-up, and no difference was found in the mean head circumference between groups. A similar percentage of infants in each group was rehospitalized (38% Epo and 35% placebo/control) for similar reasons. There were no differences between groups with respect to the percentage of infants with Bayley-II Mental Developmental Index <70 (34% Epo and 36% placebo/control), blindness (0% Epo and 2% placebo/control), deafness or hearing loss requiring amplification (2% Epo and 2% placebo/control), moderate to severe cerebral palsy (16% Epo and 18% placebo/control) or the percentage of infants with any of the above-described neurodevelopmental impairments (42% Epo and 44% placebo/control). CONCLUSIONS: Treatment of ELBW infants with early Epo and iron does not significantly influence anthropometric measurements, need for rehospitalization, transfusions after discharge, or developmental outcome at 18 to 22 months' corrected age.

Blindness↗

PubMed2003

Breastfeeding practices in a cohort of inner-city women: the role of contraindications.

BACKGROUND: Little is known about the role of breastfeeding contraindications in breastfeeding practices. Our objectives were to 1) identify predictors of breastfeeding initiation and duration among a cohort of predominantly low-income, inner-city women, and 2) evaluate the contribution of breastfeeding contraindications to breastfeeding practices. METHODS: Mother-infant dyads were systematically selected from 3 District of Columbia hospitals between 1995 and 1996. Breastfeeding contraindications and potential predictors of breastfeeding practices were identified through medical record reviews and interviews conducted after delivery (baseline). Interviews were conducted at 3-7 months postpartum and again at 7-12 months postpartum to determine breastfeeding initiation rates and duration. Multivariable logistic regression analysis was used to identify baseline factors associated with initiation of breastfeeding. Cox proportional hazards models were generated to identify baseline factors associated with duration of breastfeeding. RESULTS: Of 393 study participants, 201 (51%) initiated breastfeeding. A total of 61 women (16%) had at lease one documented contraindication to breastfeeding; 94% of these had a history of HIV infection and/or cocaine use. Of the 332 women with no documented contraindications, 58% initiated breastfeeding, vs. 13% of women with a contraindication. In adjusted analysis, factors most strongly associated with breastfeeding initiation were presence of a contraindication (adjusted odds ratio [AOR], 0.19; 95% confidence interval [CI], 0.08-0.47), and mother foreign-born (AOR, 4.90; 95% CI, 2.38-10.10). Twenty-five percent of study participants who did not initiate breastfeeding cited concern about passing dangerous things to their infants through breast milk. Factors associated with discontinuation of breastfeeding (all protective) included mother foreign-born (hazard ratio [HR], 0.55; 95% CI 0.39-0.77) increasing maternal age (HR for 5-year increments, 0.80; 95% CI, 0.69-0.92), and infant birth weight > or = 2500 grams (HR, 0.45; 95% CI, 0.26-0.80). CONCLUSIONS: Breastfeeding initiation rates and duration were suboptimal in this inner-city population. Many women who did not breastfeed had contraindications and/or were concerned about passing dangerous things to their infants through breast milk. It is important to consider the prevalence of contraindications to breastfeeding when evaluating breastfeeding practices in high-risk communities.

Adult↗

PubMed2003

Infant-parent bed sharing in an inner-city population.

BACKGROUND: In the United States, infant-parent bed sharing is a controversial and poorly understood practice. Proponents site potential advantages such as increases in bonding and facilitation of breastfeeding, whereas opponents site potential increases in risks of suffocation and sudden infant death syndrome, particularly among mothers who smoke. Few studies have examined normative practices in low-income populations. OBJECTIVES: To describe sleep practices in a cohort of infants born to predominantly low-income, inner-city mothers, to examine stability in sleep practices during the first 7 to 12 months of life, and to identify factors associated with bed sharing. DESIGN AND SETTING: Prospective birth cohort study in the District of Columbia, with recruitment taking place between August 1995 and September 1996 and follow-up from November 1995 to September 1997. PARTICIPANTS: Maternal-infant pairs were systematically selected from 3 hospitals. We interviewed 394 mothers shortly after delivery and at 3 to 7 months post partum. Of these, 369 were interviewed again at 7 to 12 months post partum. MAIN OUTCOME MEASURE: Usual bed sharing. RESULTS: At age 3 to 7 months (mean age, 129 days), 201 infants (51%) usually slept alone and 191 (48%) usually slept in a bed with a parent or other adult. Similarly, at age 7 to 12 months (mean age, 262 days), 190 infants (51%) usually slept alone and 175 (47%) usually slept in a bed with a parent or other adult. Of the infants who slept with a parent or other adult at age 3 to 7 months, 75% continued to do so at age 7 to 12 months. Similarly, of infants who usually slept alone at age 3 to 7 months, only 22% were reported to be usual bed sharers at age 7 to 12 months. In multivariate analyses, factors associated with bed sharing at both follow-up interviews included single marital status of the mother (first interview: odds ratio [OR] = 1.90; 95% confidence interval [CI], 1.11-3.27; second interview: OR = 1.81; 95% CI, 1.02-3.25) and 1 or more moves since the birth of the infant (first interview: OR = 1.82; 95% CI, 1.10-3.01; second interview: OR = 1.73; 95% CI, 1.05-2.86). Breastfeeding and household crowding were not significantly associated with bed sharing. CONCLUSIONS: Bed sharing was common in this inner-city population, and sleep practices were relatively stable during the first 7 to 12 months of life. These findings underscore the need for additional research clarifying the benefits and risks of bed sharing.

Adult↗

PubMed2003

Geographic information systems and spatial analysis of adult Ixodes scapularis (Acari: Ixodidae) in the Middle Atlantic region of the U.S.A.

In the Middle Atlantic region of the U.S.A., the vector of Lyme disease, human granulocytic ehrlichiosis, babesiosis, and other human and veterinary pathogens is the black-legged tick, Ixodes scapularis Say. In 1997 and 1998, 663 adult I. scapularis ticks were collected from 320 transects spanning 66,400 km2 in five states of the Middle Atlantic region. Tick abundance patterns were clustered, with relatively high numbers along the coastal plain of the Chesapeake Bay, decreasing to the west and south. There were significant associations between tick abundance and land cover, distance to water, distance to forest edge, elevation, and soil type.

Animals↗

PubMed2002

Gestational cocaine exposure and intrauterine growth: maternal lifestyle study.

OBJECTIVE: To estimate the effects of cocaine exposure on intrauterine growth and to investigate at what point in gestation growth deviation would be manifested. METHODS: This is a secondary analysis of data from a multicenter project, the Maternal Lifestyle Study, designed to determine infant outcomes of in utero cocaine or opiates exposure. Four centers of the National Institute of Child Health and Human Development Neonatal Research Network enrolled 11,811 maternal-infant dyads. A total of 1072 infants were cocaine exposed, 7565 were cocaine negative by maternal history and meconium results, and 3174 were excluded from analysis because of unconfirmed negative exposure. Outcome measures included birth weight, length, and head circumference. RESULTS: Percentile estimates for birth weight, length, and head circumference revealed growth deceleration in cocaine-exposed infants evident after 32 weeks' gestation. There was significant interaction between cocaine and gestational age. After controlling for confounders, at 40 weeks' gestation, cocaine exposure was estimated to be associated with a decrease of 151 g, 0.71 cm, and 0.43 cm in birth weight, length, and head circumference, respectively. Smoking had a negative impact on all growth measurements, with some indication of a dose-effect relationship. Heavy alcohol use was associated with decrease in weight and length only. Opiates had significant effect only on birth weight. CONCLUSION: In utero cocaine exposure is associated with growth deceleration involving all measurements, becoming more pronounced with advancing gestation.

Adult↗

PubMedDate not supplied

Health-care utilization among mothers and infants following cocaine exposure.

OBJECTIVE: To examine utilization of health-care resources among mothers and infants following cocaine use during pregnancy. DESIGN: Prospective observational study. SETTING: Four clinical sites. PATIENTS/METHODS: Medical and social services resource use was examined among 8514 mother-infant dyads, 1072 of whom used cocaine and 7442 who did not. Use was stratified by <1500 g and >1500 g birth-weight strata to differentiate the low birth weight from the larger weight group adjusting for site, infant gender, and maternal race and education. OUTCOME MEASURES: Resource use evaluated among mothers included prenatal care, hospitalizations, medications and mode of delivery. Resource use for infants included therapies, procedures and length of stay. RESULTS: Fewer cocaine-exposed women, compared to those in the nonexposed group, had prenatal care or used medications during pregnancy in both <1500 g category 0.10 (0.04 to 0.22) (OR (99% CI) and 0.26 (0.10 to 0.65), respectively, and in the >1500 g category 0.14 (0.11 to 0.19) and 0.61 (0.49 to 0.74), respectively. Length of hospital stay for social reasons and referrals to child protective services were increased in cocaine-exposed infants in both <1500 g category 66.8 (4.38 to 999.9) and 77.4 (17.64 to 289.13), respectively and in the >1500 g category 70.74 (41.73 to 119.94) and 125.88 (81.78 to 193.77), respectively. In addition, among >1500 g cocaine-exposed infants, length of stay in neonatal intensive care unit was increased 1.53 (1.16 to 2.02) as was therapies 1.76 (1.45 to 2.13), procedures 1.50 (1.23 to 1.83), need for formula feeds 5.45 (2.28 to 13.02) and intravenous fluids 1.50 (1.19 to 1.87), CONCLUSION: Cocaine exposure has no deleterious or protective effects on medical resource needs of <1500 g infants or their mothers. Resource needs reflect those of morbidity of being born premature. The increase in health-care resources for >1500 g cocaine-exposed infants for surveillance and monitoring in the absence of an increase in congenital anomalies should be discouraged.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Audio computerized self-report interview use in prenatal clinics: audio computer-assisted self interview with touch screen to detect alcohol consumption in pregnant women: application of a new technology to an old problem.

Computer interviewing to obtain sensitive information is not a new concept. However, concerns about the acceptance of computers in disadvantaged populations with potentially low literacy led us to combine audio- and touch-screen technologies with an audio computerized self-report interview to obtain information about alcohol use. This study evaluated acceptance and ease of use by a disadvantaged population of pregnant women in the District of Columbia. Patients attending an initial visit at prenatal clinics answered questions anonymously about their consumption of alcoholic beverages and other personal information. The questionnaire was programmed on a laptop computer. The computer administered the recorded questions via earphones, as well as displayed them on the screen, and patients answered by touching the computer screen. Results were immediately available. A total of 507 women were interviewed, who were primarily African American, non-Hispanic, and never married. Nearly 24% did not complete a high school education, 43% were unemployed, and 30% received public assistance. Most of the women (59%) used computers occasionally (a few days a month) or never. Nearly all patients (96%) reported that the computer was not difficult to use, and approximately 90% liked answering the questions by computer. The study demonstrates that using computers to screen for alcohol use in disadvantaged pregnant populations is feasible and acceptable to the patients.

Adolescent↗