Search PubMed⌕ Search

Biomedical subjects

T Joyce

Publications and source records attributed to T Joyce.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prevalence of enteropathogens in stools of rural Maasai children under five years of age in the Maasailand region of the Kenyan Rift Valley.

Stool samples were collected during August 1994 from seventy rural Maasai children under the age of five years who were living in the Maasailand region of the Kenyan Rift Valley. Microbiological analysis was carried out on these samples to identify which intestinal pathogens were present among the infant population of the Maasai. Of the samples studied 54% were pathogen positive. The most common pathogen isolated was Giardia lamblia which was detected in 31% of the samples. Other pathogens that were detected include: Entamoeba histolytica (23%), Enteropathogenic Escherichia coli (13%), Strongyloides stercoralis (4%), Blastocystis hominis (3%) and Cryptosporidium sp (3%). Although all samples were screened for Campylobacter and rotavirus, neither pathogen was detected. Water samples were taken from all the water sources in the study area and analysed microbiologically. Results showed that all the sources were contaminated with the faecal E. coli whose populations ranged from 14 CFU/100 ml to greater than 1800 CFU/100ml.

Age Distribution↗
PubMed1996

The effect of expansions in Medicaid income eligibility on abortion.

In this paper we examine the effect of expansions in Medicaid income eligibility on abortion, using individual-level data from South Carolina, Tennessee, and Virginia. The results suggest that for unmarried nonblack women with less than a high school degree, expansions of income eligibility lowered the probability of abortion by two to five percentage points. Most of the impact of the Medicaid expansions on abortion occurred in the first round of expansions from approximately 45% of the federal poverty level to 100%. For black unmarried women with less than a high school degree, we generally find no effect of expansions in Medicaid income eligibility on abortion.

Abortion, Induced↗
PubMed1995

Glycine N-methyltransferase is a mediator of cytochrome P4501A1 gene expression.

Cytochrome P4501A1, the isozyme most closely approximating aryl hydrocarbon hydroxylase activity under conditions of induction, is thought to be regulated by several trans-acting factors, including the 4S polycyclic aromatic hydrocarbon-binding protein; this protein has recently been identified as glycine N-methyltransferase (Raha et al. (1994) J. Biol. Chem. 269, 5750-5756). Previous studies had shown that partially purified liver preparations containing the 4S binding protein interacted with 5'-flanking regions of the cytochrome P4501A1 gene. Consequently, the ability of the 4S binding protein to serve as a mediator in the regulation of the cytochrome P4501A1 gene was investigated further. Introduction of an antisense 24-mer oligonucleotide to glycine N-methyltransferase cDNA into rat hepatoma H4IIE cells by lipofectin resulted in a 60% reduction in the benzo(a)pyrene-mediated induction of ethoxyresorufin-O-deethylase activity and protein over the sense and scrambled antisense oligonucleotide controls. In addition, the antisense oligonucleotide caused a marked reduction in the steady-state level of cytochrome P4501A1 mRNA; no such effect was observed with the sense oligonucleotide. Introduction of GNMT polyclonal antibodies into H4IIE cells by a streptolysin-O permeabilization technique markedly reduced both benzo(a)pyrene-binding and benzo(a)-pyrene-induced ethoxyresorufin-O-deethylase activities, but had no effect on 2,3,7,8-tetrachlorodibenzo-p-dioxin induction. Collectively, these findings suggest that, in addition to the Ah (dioxin) receptor, glycine N-methyltransferase appears to be both a polycyclic aromatic hydrocarbon-binding protein and a mediator of the induction of the cytochrome P4501A1 gene by polycyclic hydrocarbons such as benzo(a)pyrene.

Animals↗
PubMed1995

NF-E2 and GATA binding motifs are required for the formation of DNase I hypersensitive site 4 of the human beta-globin locus control region.

The beta-like globin genes require the upstream locus control region (LCR) for proper expression. The active elements of the LCR coincide with strong erythroid-specific DNase I-hypersensitive sites (HSs). We have used 5' HS4 as a model to study the formation of these HSs. Previously, we identified a 101 bp element that is required for the formation of this HS. This element binds six proteins in vitro. We now report a mutational analysis of the HS4 HS-forming element (HSFE). This analysis indicates that binding sites for the hematopoietic transcription factors NF-E2 and GATA-1 are required for the formation of the characteristic chromatin structure of the HS following stable transfection into murine erythroleukemia cells. Similarly arranged NF-E2 and GATA binding sites are present in the other HSs of the human LCR, as well as in the homologous mouse and goat sequences and the chicken beta-globin enhancer. A combination of DNase I and micrococcal nuclease sensitivity assays indicates that the characteristic erythroid-specific hypersensitivity of HS4 to DNase I is the result of tissue-specific alterations in both nucleosome positioning and tertiary DNA structure.

Animals↗
PubMed1995

The impact of prenatal exposure to cocaine on newborn costs and length of stay.

OBJECTIVE: Our intention is to determine newborn costs and lengths of stay attributable to prenatal exposure to cocaine and other illicit drugs. DATA SOURCES AND STUDY SETTING: All parturients who delivered at a large municipal hospital in New York City between November 18, 1991 and April 11, 1992. STUDY DESIGN: A cross-sectional analysis used multivariate, loglinear regressions to analyze differences in costs and length of stay between infants exposed and unexposed prenatally to cocaine and other illicit drugs, adjusting for maternal race, age, prenatal care, tobacco, parity, type of delivery, birth weight, prematurity, and newborn infection. DATA COLLECTION/EXTRACTION METHODS: Urine specimens, with linked obstetric sheets and discharge abstracts, provided information on exposure, prenatal behaviors, costs, length of stay, and discharge disposition. PRINCIPAL FINDINGS: Infants exposed to cocaine or some other illicit drug stay approximately seven days longer at a cost of $7,731 more than infants unexposed. Approximately 60 percent of these costs are indirect, the result of adverse birth outcomes and newborn infection. Hospital screening as recorded on discharge abstracts substantially underestimates prevalence at delivery, but overestimates its impact on costs.

Adult↗
PubMed1993

The association between prenatal care and birth weight among women exposed to cocaine in New York City.

OBJECTIVES: Although the association between antenatal cocaine use and adverse birth outcomes has been well documented, relatively little is known about interventions that may ameliorate these consequences. We therefore examined the relationship between prenatal care and birth weight among a population of prenatal cocaine users. DESIGN: Population-based retrospective analysis. PATIENTS: All single-gestation live births to white non-Hispanic, black non-Hispanic, and Hispanic residents of New York City who gave birth between 1988 and 1990 with a positive indication for cocaine recorded on birth certificates (N = 7923). MAIN OUTCOME MEASURES: We contrasted mean birth weight and rates of low birth weight (< 2500 g) among cocaine users with one to three prenatal care visits, four or more visits, and unknown numbers of visits with users who reported no prenatal care. We used ordinary least squares and logistic regression to control for age, parity, smoking, alcohol, other drugs, weight gain, prepregnancy weight, employment, marital status, participation in the Supplemental Food Program for Women, Infants and Children, and method of finance. MAIN RESULTS: Adjusted odds ratios of low birth weight for cocaine users with four prenatal care visits or more as compared with those who had none were 0.51 for blacks (95% confidence interval [CI], 0.44 to 0.59), 0.39 for whites (95% CI, 0.23 to 0.66), and 0.37 for Hispanics (95% CI, 0.28 to 0.48). Adjusted mean birth weight differences between users with four visits or more and those with none were 262 g for blacks (P < .001), 247 g for whites (P < .001), and 317 g for Hispanics (P < .001). CONCLUSIONS: The receipt of prenatal care among cocaine users is associated with significant improvements in birth weight. Enrollment of cocaine users in prenatal care may be an effective start to a more comprehensive approach to this problem.

Adult↗
PubMed1993

Metabolism of chlorinated guaiacols by a guaiacol-degrading Acinetobacter junii strain.

The metabolism of chlorinated guaiacols by a pure bacterial strain identified by its ability to use guaiacol as the sole carbon and energy source was studied. This strain, identified as Acinetobacter junii 5ga, was unable to grow on several chlorinated guaiacols and catechols. However, strain 5ga grown on guaiacol degraded 4- and 5-chloroguaiacol and 4,5-dichloroguaiacol. Under the same conditions, these cells did not degrade 6-chloroguaiacol, 4,6-dichloroguaiacol, 4,5,6-trichloroguaiacol, or tetrachloroguaiacol, suggesting that the substitution at the 6 position in the ring prevents metabolism of the compound. Degradation of 4-chloroguaiacol was dependent on the initial ratio between the chlorinated compound and viable cells. Transient formation of chlorocatechols resulting from incubation of cells with 4-chloroguaiacol or 4,5-dichloroguaiacol was suggested by UV spectroscopy. Gas chromatography analyses of samples from cultures of strain 5ga grown on guaiacol and incubated with 4- and 4,5-dichloroguaiacol confirmed the presence of 4-chlorocatechol and 4,5-dichlorocatechol, respectively. The formation of the latter was corroborated by gas chromatography-mass spectrometry. Thus, this strain is able to initiate metabolism of specific chlorinated guaiacols by O-demethylation. The starting chlorinated guaiacols and their O-demethylated metabolites inhibited the growth of A. junii 5ga on guaiacol.

Acinetobacter↗
PubMed1993

An update on New York City's dramatic increase in low birthweights.

Monthly time-series data on rates of low birthweight and very low birthweight in New York City from 1963 to 1990 indicate that the dramatic increase, particularly among Blacks beginning in 1984, appears to have peaked in 1988. Based on vital statistics records, the rate of low birthweight for Blacks fell from 13.1% in 1988 to 12.1% in 1990. The rate of low birthweight among Whites and Hispanics has fallen slightly since 1988.

Ethnicity↗
PubMed1992

The consequences and costs of maternal substance abuse in New York City. A pooled time-series, cross-section analysis.

We use a pooled time-series cross-section of live births in New York City between 1980 and 1989 to investigate the dramatic rise in low birthweight, especially among Blacks, that occurred in the mid 1980s. After controlling for other risk factors, we estimate that the number of excess low birthweight births attributable to illicit substance abuse over this period ranged from approximately 1,482 to 3,359. The increase represents between 3.2 and 7.3% of all LBW over the period resulting in excess neonatal admission costs of between $18 and $41 million.

Black or African American↗
PubMed1990

The dynamic relationship between low birthweight and induced abortion in New York City. An aggregate time-series analysis.

We use a vector autoregression to examine the dynamic relationship between the race-specific percentage of pregnancies terminated by induced abortion and the race-specific percentage of low-birthweight births in New York City. With monthly data beginning in 1972, we find that induced abortion explains low birthweight for blacks, but not for whites. There is no evidence of feedback from low birthweight to induced abortion. The findings suggest that unanticipated decreases in the percentage of pregnancies terminated by induced abortion would worsen birth outcomes among blacks in New York City.

Abortion, Induced↗
PubMed1990

The dramatic increase in the rate of low birthweight in New York City: an aggregate time-series analysis.

This paper uses monthly time-series data from 1968 through 1988 to test whether the observed increase in the incidence of low birthweight in New York City represents a reversal of the downward trend that existed prior to 1984. We find that the trend has shifted for both Whites and Blacks. We estimate that between July 1984 and December 1988 there were 3,110 additional low-birthweight births to Blacks and 1,385 additional low-birthweight births to Whites above what would have been expected had the rate of low birthweight not shifted upwards. The incremental costs of treating these infants in their first year of life is estimated at over $22,000,000 in 1986 dollars.

Black People↗
PubMed1989

A time-series analysis of unemployment and health. The case of birth outcomes in New York City.

The paper presents an aggregate time-series analysis of unemployment and infant health that improves on previous work in several ways. First, the data is monthly as opposed to annual. Second, the measure of health, the percentage of low-birthweight births, and the health inputs are race-specific. Third, because a pregnancy is limited to at most ten months, we can specify a lag length with a greater degree of confidence. We find no cyclical variation in the percentage of low-birthweight births. The results are insensitive to changes in lag length, health inputs, and functional form.

Black or African American↗
PubMed1989

Spinal opioids and the treatment of the obstetric patient with cardiac disease.

The administration of narcotics into the spinal or epidural space has proven to be efficacious in the relief of mild to moderate pain. Unlike local anesthetics, intraspinal opioids are not associated with a decrease in systemic vascular resistance. Recent research has shown that opioids alone, or combined with local anesthetics, offer distinct advantages over the use of local anesthetics, alone when providing analgesia for the pregnant patient with cardiac disease.

Analgesia↗
PubMed1988

A cost-effectiveness analysis of strategies to reduce infant mortality.

This study compares the cost effectiveness of various health inputs and government programs in reducing race-specific neonatal mortality or death in the first 27 days of life. Approximately two thirds of all infant deaths occur within this period. The programs and inputs at issue are teenage family planning use; the supplemental food program for women, infants, and children (WIC); use of community health centers and maternal and infant care projects; abortion; prenatal care; and neonatal intensive care. Using an economic model of the family as the analytic framework, effectiveness is determined by using ordinary least squares and two-stage least squares to estimate infant health production functions across large counties in the United States in 1977. Estimates of costs are from a number of published sources. We find the early initiation of prenatal care to be the most cost-effective means of reducing the neonatal mortality rate for blacks and whites. Moreover, blacks benefit more per dollar of input use than whites. Neonatal intensive care, although the most effective means of reducing neonatal mortality rates, is one of the least cost-effective strategies.

Child Health Services↗