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Biomedical subjects

T Joyce

Publications and source records attributed to T Joyce.

At least 19 recordsLinked to original sources
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

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↗
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

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↗
PubMed1988

The social and economic correlates of pregnancy resolution among adolescents in New York City, by race and ethnicity: a multivariate analysis.

This study utilizes a data set combining vital records from live birth and induced abortion certificates in New York City in 1984 to examine the correlates of the two outcomes among pregnant adolescents. Four groups totaling 31,207 teenagers were examined: Black non-Latinos (51 per cent), White non-Latinos (17 per cent), Puerto Ricans (25 per cent), and non-Puerto Rican Latinos (8 per cent). Multivariate regressions were fit for each group. Simulations based on the regressions reveal that the proportion of live births plus induced abortions among unmarried 18-year-olds, on Medicaid, with a previous live birth, no previous induced abortions, and nine years of completed schooling was .55 in the case of Puerto Ricans, .34 for non-Puerto Rican Latinos, .60 for Blacks, and .51 for Whites. For nulliparous adolescents of the same age and marital status, with an additional year of schooling, but not on Medicaid, and with a previous induced abortion, the fraction of pregnancies that were terminated rose to .84 in the case of Puerto Ricans, .81 for non-Puerto Rican Latinos, .87 for Blacks, and .96 for Whites. The results suggest that attitudes toward abortion as proxied by previous induced terminations substantially increase the likelihood of aborting as well as narrow the racial and ethnic differences with respect to pregnancy resolution.

Adolescent↗
PubMed1987

The demand for health inputs and their impact on the black neonatal mortality rate in the U.S.

Relatively high birth rates among black adolescents and unmarried women as well as inadequate access to medical care are considered primary reasons why the black neonatal mortality rate is almost double that of whites. Using household production theory, this paper examines the determinants of input utilization and estimates the impact of utilization on the survival of black infants across large counties in the U.S. in 1977. The results indicate that expanding the availability of family planning clinics increases the number of teenagers served resulting in a lower neonatal mortality rate. Accessibility to abortion services operates in a similar manner. Moreover, the use of neonatal intensive care, which is strongly related to its availability, is an important determinant of newborn survivability whereas the initiation of early prenatal care is not. Overall, the results suggest that lowering the incidence of low-weight and preterm births among blacks by helping women to avoid an unwanted birth, may be the most cost-effective way of improving black infant health.

Abortion, Induced↗
PubMed1987

The impact of induced abortion on black and white birth outcomes in the United States.

This paper examines the impact of induced abortion on birth outcomes by treating abortion as an endogenous input into the production of infant health. To gauge the direct and indirect effects of abortion, three measures of infant health are considered simultaneously: the neonatal mortality rate, the percentage of low-weight births, and the percentage of preterm births. All three are race specific and all pertain to large counties in the United States in 1977. The results suggest that by preventing unwanted births, abortion enhances the survivability of newborns of a given birth weight and improves the distribution of births among high-risk groups.

Abortion, Induced↗
PubMed1981

The effects of bupivacaine and chloroprocaine as local anesthetics for epidural anesthesia of fetal heart rate monitoring parameters.

The effects of saline-induced pressure-volume changes in the epidural space, and bupivacaine and chloroprocaine as local anesthetics for epidural anesthesia, on various fetal heart rate monitor parameters were investigated in 34 low-risk women. Epidural space pressure-volume changes, bupivacaine, and chloroprocaine had no effect on the incidence of pathologic periodic fetal heart rate changes, the level of the baseline fetal heart rate, or the level of uterine activity units. Epidural space pressure-volume changes and chloroprocaine did not affect fetal heart rate variability. The use of bupivacaine was associated with a significant increase in fetal heart rate variability

Adult↗
PubMed1980

Capillaria plica infection in dogs.

The prevalence, pathologic effects, and treatment of Capillaria plica infection were investigated in two breeding kennels. The prevalence of C plica infection in mature dogs in two kennels (127 dogs) was 76% and 59%. Pups less than 8 months old did not pass C plica eggs in the urine. Age, breed, or sex predilection was not observed in mature dogs. In infected dogs, hematuria, dysuria, and pollakiuria developed without secondary bacterial cystitis. A direct life cycle could not be demonstrated experimentally. Histologically, adult C plica were seen in the submucosa of the bladder and ureter, where they induced a mild inflammatory reaction and submucosal edema.

Animals↗
PubMed1979

Characterization of renal defects in dogs with a syndrome similar to the Fanconi syndrome in man.

Ten adult dogs with multiple spontaneous defects of renal tubular reabsorption were studied. Clinical signs included polydipsia, polyuria, and glycosuria for 2 to 12 months. Eight of the dogs were Basenjis. Urinalyses revealed hyposthenuria, glycosuria, and amino aciduria in most dogs. Renal function was normal in 5 dogs and slightly reduced in the remainder. Moderate metabolic acidosis had developed in 3 dogs. Renal clearance studies revealed reduced tubular reabsorption of glucose, phosphate, sodium, potassium, and uric acid. Abnormal glucose tubular maximal curves were found. Results of oral glucose tolerance tests were normal. Two patterns of abnormal amino aciduria were evident: generalized amino aciduria and a pattern similar to that of cystinuria in dogs. Radiography of long bones and bone densitometry did not reveal any skeletal abnormalities. Five of the dogs died within 90 days of diagnosis; death was due to acute renal failure associated with profound dehydration, acidosis, and papillary necrosis. The other dogs remained stable without treatment after 18 months. Histopathology of kidneys did not reveal uniform abnormalities; some dogs had variable and nonspecific changes and others were normal. Electron microscopy did not reveal ultrastructural abnormalities in renal tubular cells. It was concluded that the syndrome in these dogs represents a new entity of renal disease in dogs, similar to idiopathic Fanconi syndrome in man.

Animals↗
PubMed1979

Clinical evaluation of glomerular function: 24-hour creatinine clearance in dogs.

Methods of renal clearance to measure glomerular filtration rate (GFR) were compared with plasma creatinine concentration in clinically normal and partially nephrectomized dogs. Glomerular filtration rate was measured by use of a simple 24-hour creatinine clearance method in 36 normal female Beagles. Mean values were 57.6 +/- 9.3 ml/minute/m2 of body surface or 3.7 +/- 0.77 ml/minute/kg of body weight. Variability of this measurement was considerable, as determined in 4 dogs studied on 4 consecutive days. Glomerular filtration rate was measured in the same 36 dogs while they were under anesthesia, using short clearance periods to compare inulin and endogenous creatinine clearance. Mean values for inulin were 41.8 +/- 13.9 ml/minute/m2 of body surface. A close agreement with creatinine clearance was found (correlation coefficient, 0.998). Mean plasma creatinine concentration was 0.82 (range, 0.5--1.0) mg/100 ml. The value of GFR measurement compared with plasma creatinine concentration was determined in 10 dogs after 75% nephrectomy. Sixty days after partial nephrectomy, GFR was reduced to 61% of normal. Mean plasma creatinine and blood urea nitrogen were 1.2 +/- 0.14 mg/100 ml and 20.4 +/- 7.1 mg/100 ml, respectively. Thus, the detection of reduced renal function may be uncertain when plasma creatinine or blood urea nitrogen are used as a means of evaluating renal function. It was concluded that a simple method of creatinine clearance is a sensitive and useful measurement to detect early or borderline reduction in glomerular function.

Anesthesia↗
PubMed1978

The fanconi syndrome in Basenji dogs: a new model for renal transport defects.

The renal defects resulting in a Fanconi syndrome were seen in eight Basenji dogs by measuring renal clearance and in vitro amino acid and sugar uptake and performing histopathologic evaluations. Renal tubular handling of glucose, phosphate, sodium, potassium, uric acid, and amino acids was abnormal, and in vitro uptake of labeled lysine, glycine, and alpha-methyl-D-glucoside by renal cortical slices was impaired. Histopathology was normal except for enlarged nuclei in some renal tubule cells. These Basenji dogs, which may be genetically affected, represent a likely model for idiopathic Fanconi syndrome in humans.

Amino Acids↗
PubMed1978

Spontaneous Fanconi syndrome in the dog.

Three dogs with spontaneous renal tubular defects similar to idiopathic Fanconi syndrome are characterized. Renal clearance studies revealed a fractional reabsorption of glucose ranging from 31% to 82%. Abnormal glucose thulium values were present in all dogs. A generalized aminoaciduria occurred in two dogs while one had aminoaciduria characteristic of canine cystinuria. Fractional reabsorption of phosphate ranged from 47% to 79%. In vitro uptake of alpha-methyl-D-glucoside was significantly depressed (p less than 0.001). In vitro uptake of amino isobutyric acid was similar to controls. Renal biopsy revealed nonspecific interstitial change in two dogs and normal histology in the other. These animals represent a useful new model for the study of renal tubular transport defects.

Amino Acids↗