PubMed Health⌕ Search

Biomedical subjects

J W Collins

Publications and source records attributed to J W Collins.

15 recordsLinked to original sources
PubMed1992

Disparate black and white neonatal mortality rates among infants of normal birth weight in Chicago: a population study.

To determine the extent to which disparities in risk status and access to tertiary care affect racial differences in neonatal mortality rates among normal birth weight infants, we conducted a vital records study concerning normal weight black (N = 44,399) and white (N = 48,146) singleton births in Chicago. Neonatal mortality rate among black infants was twice that among white infants (3.3 deaths per 1000 births vs 1.5 deaths per 1000 births); the unadjusted black relative risk equaled 2.2 (95% confidence interval, 1.7 to 2.9). Because prematurity, growth retardation, congenital anomalies, low Apgar scores at 5 minutes, teenage mothers, and poverty were more common among black infants, multivariate analyses were performed. The disparity in mortality rate was greatest between black and white infants with none of these risk factors; relative risk for black infants equaled 3.6 (95% confidence interval, 2.0 to 6.7). Approximately 30% of all deaths of black infants were attributable to birth in nontertiary hospitals. When the confounding variables, including hospital of birth, were put into a multivariate logistic-regression model, the adjusted relative risk estimate (odds ratio) for black infants equaled 1.5 (95% confidence interval, 1.1 to 2.0). Traditional risk factors fail to explain the racial disparity in neonatal mortality rate among normal birth weight infants. Level of perinatal care available, or some factor closely related to this level, is an important determinant of neonatal chance of survival for normal birth weight urban black infants.

Black or African American↗
PubMed1992

Differences in neonatal mortality by race, income, and prenatal care.

To determine the extent to which the social and physical environment affects the association between prenatal care and black pregnancy outcome in Chicago, we performed a stratified analysis of 1982-1983 Illinois vital records and 1980 United States census income data. Median family income of the mother's census tract was used as the ecologic variable. In very-low-income census tracts (less than $10,000 per year), 40% of blacks and 47% of whites received adequate prenatal care. There was no racial disparity in the percentage of low-birth-weight infants attributed to inadequate prenatal care among poor mothers. For mothers who resided in moderate-income areas ($20,001 to $30,000 per year), 50% of blacks and 67% of whites received adequate prenatal care. Although adequate (compared to inadequate) prenatal care was associated with improved birthweight distribution independent of community income, only in moderate-income areas was it related to black neonatal survival. For term black infants who received adequate prenatal care, residence in impoverished areas was associated with a nearly fourfold greater neonatal mortality rate (deaths per 1000 live births): 5/1000 vs 1/1000; RR = 3.8 (1.3-11.0). We conclude that place of residence is an important risk factor for black neonatal mortality.

Black or African American↗
PubMed1991

A controlled trial of insulin infusion and parenteral nutrition in extremely low birth weight infants with glucose intolerance.

To determine whether a continuous insulin infusion improves glucose tolerance in extremely low birth weight infants, we conducted a prospective, randomized trial in 24 neonates 4 to 14 days old (mean birth weight 772.9 +/- 128 gm; mean gestational age 26.3 +/- 1.6 weeks). Infants who had glucose intolerance were randomly assigned to receive either intravenous glucose and total parenteral nutrition with insulin through a microliter-sensitive pump or standard intravenous therapy alone. One infant assigned to receive insulin never required it. The groups were similar in birth weight, gestational age, race, gender, medical condition, and energy intake before the study. The mean duration of therapy was 14.6 days (range 7 to 21 days). During the study, the 11 insulin-treated infants tolerated higher glucose infusion rates (20.1 +/- 2.5 vs 13.2 +/- 3.2 mg/kg/min (1.1 +/- 0.1 vs 0.7 +/- 0.2 mmol/L); p less than 0.01), had greater nonprotein energy intake (124.7 +/- 18 vs 86.0 +/- 6 kcal/kg/day; p less than 0.01), and had better weight gain (20.1 +/- 12.1 vs 7.8 +/- 5.1 gm/kg/day; p less than 0.01) than the 12 control infants. The incidence of hypoglycemia, electrolyte imbalance, chronic lung disease, and death did not differ between groups. We conclude that a controlled insulin infusion improves and sustains glucose tolerance, facilitates provision of calories, and enhances weight gain in glucose-intolerant premature infants.

Blood Glucose↗
PubMed1991

Bad outcomes in black babies: race or racism?

The gap between black and white infant death rates in the United States has grown over the last three decades. Epidemiologic and medical studies by investigators seeking to understand and reverse this adverse trend have been unsuccessful. Researchers have looked in vain for the combination of social and environmental risk factors that are more common among blacks and would therefore explain this group's poor reproductive outcomes. The implicit alternate hypothesis is genetic differences between blacks and whites. In fact, there is more of a gap between black and white mothers of higher socioeconomic position than between overall black and white rates without socioeconomic stratification. An alternative to the genetic theory explains these results, however, on the basis of social risk factors that, because of the presence of widespread discrimination in the society under study, apply only to blacks. Such factors are the effects of racism, not race per se. Several lines of research are needed to investigate the effects of racism on perinatal outcomes, including studies on psychophysiological reactions to racial discrimination and on ethnic group differences in coping mechanisms, social supports, and physical environment. Analysis of trends over the past 37 years indicates that improvements in white (and total US) infant mortality rates cannot be anticipated until the racial gap is closed.

Black or African American↗
PubMed1991

The treatment of mild to moderate hypertension in patients with diabetes mellitus.

The treatment of mild to moderate hypertension in patients with diabetes mellitus is reviewed in this article. The effect of diabetic hypertension on the heart and kidney is discussed. Treatment guidelines for diabetic hypertension are provided, based on principles derived from the pathophysiology. These principles include choosing an agent that maintains or improves lipids, potassium, insulin sensitivity, and quality of life. Individuals with diabetic hypertension should be assessed for their risk of developing coronary artery disease or nephropathy, since certain antihypertensive agents may help prevent these diseases. A simple method for selecting appropriate drugs is also presented.

Antihypertensive Agents↗
PubMed1990

Differential survival rates among low-birth-weight black and white infants in a tertiary care hospital.

Birth-weight-specific mortality is lower for black prematures than white prematures of similar low birth weight. The reason for this well-recognized phenomenon is unknown. We investigated the extent to which black and white infants differ in their gestational maturity and incidence of potentially lethal risk factors, and the effect these factors might have on differential mortality risk. The population studied comprised babies born alive in a tertiary care hospital with birth weights from 700 to 1800 g over a 4 1/2-year period. Univariate analysis showed no important difference between races for the incidence of lung disease, Apgar scores, birth weight, or gestational age. Infants with a birth weight below the 10th percentile (small for gestational age) were more likely to be black, and infants with a birth weight above the 90th percentile (large for gestational age) who had a survival disadvantage were usually white. The crude odds ratio for the white race was 1.79 (1.18-2.73). When the demographic, morbidity, and growth variables were put into a logistic model, the odds ratio changed only slightly, to 1.52 (1.14-2.03). We conclude that the majority of the black-white difference in birth-weight-specific survival is not due to a higher incidence of black small-for-gestational-age infants, nor is it due to differences in major morbidities associated with death.

Academic Medical Centers↗
PubMed1990

Intrauterine growth retardation: altered hepatic energy and redox states in the fetal rat.

We determined the extent to which ligating both maternal uterine arteries affects fetal hepatic energy and redox states in the fetal rat. Bilateral maternal uterine artery ligation on d 18 of the rat's 21.5-d gestation significantly inhibits fetal growth; sham surgery limits growth to a lesser extent. Within 12 h of surgery and persisting to d 19, small-for-gestational age (SGA) fetuses had significantly diminished ATP/ADP and adenylate charge ratios, whereas sham fetuses had values intermediate between SGA and normal. Hepatic mitochondrial redox state demonstrated similar changes. Cytosolic redox state in SGA fetuses at 12 and 24 h after surgery was significantly elevated. SGA fetuses had significantly diminished plasma insulin and elevated glucagon concentrations. On d 19 and 20, hepatic ATP/ADP and cytosolic NAD+/NADH correlated directly for sham and normal but not SGA fetuses. Alterations in glucose, insulin, and glucagon availability and hypoxia were responsible for the changes in energy and redox states. They may also have disassociated hepatic cytosolic from mitochondrial redox states and altered the equilibrium between adenine and nicotinamide nucleotides. These altered cellular functions retarded fetal growth. Newborn SGA, sham, and normal rat pups had similar hepatic ATP/ADP, cytosolic, and mitochondrial redox states at 10 and 240 min after delivery suggesting that the hypoglycemia which developed in SGA pups was not attributable to alterations in these variables.

Animals↗
PubMed1990

The differential effect of traditional risk factors on infant birthweight among blacks and whites in Chicago.

We analyzed 103,072 White and Black births in Chicago from the 1982 and 1983 Illinois vital records, using 1980 median family income of mother's census tract as an ecologic variable. Thirty-one percent of Blacks and 4 percent of Whites resided in census tracts with median family incomes less than or equal to $10,000/year. Only 2 percent of Black mothers, compared to 16 percent of White mothers, lived in areas where the median family income was greater than $25,000/year. Among Blacks with incomes less than or equal to $10,000/year, maternal age, education, and marital status had minimal predictive power on the incidence of low birthweight (LBW) infants. Among high-risk mothers in the poorest areas the proportion of LBW infants in Blacks and Whites was less divergent than in higher income areas. Independent of residential area, low-risk Whites had half the occurrence of LBW infants as Blacks. We conclude that the extremes of residential environments show dramatic racial disparity in prevalence, yet the few low-risk Blacks still do less well than low-risk Whites. Traditional risk factors do not completely explain racial differences in neonatal outcome.

Adult↗
PubMed1990

Visual performance in high myopia.

The visual performances of eight low myopic subjects (-2 D to -7 D) and eight high myopic subjects (greater than -7 D) with normal visual acuities were analyzed by contrast sensitivity testing with both spectacle and contact lens corrections to determine if any differences in function exist between those groups. Statistically significant (p = 0.0382) contrast sensitivity losses, particularly at the higher spatial frequencies, were found for the high myopic subjects when corrected with spectacles. However, with contact lens correction, no statistically significant overall difference between the two groups was evident (p = 0.5083). We believe that these results confirm for highly myopic subjects the lack of any consistently present loss of resolution. The differences with spectacle correction are attributable to the nature of the optical correction.

Adult↗
PubMed1988

Insulin injection in the fetal rat: accelerated intrauterine growth and altered fetal and neonatal glucose homeostasis.

Fetal hyperinsulinemia is a well-known correlate of accelerated fetal growth; the consequences of fetal hyperinsulinemia upon fetal and neonatal glucoregulation are less well understood. We injected rat fetuses of a litter on day 18 of gestation with either 5 units of long acting insulin (I) or 154 mmol/L NaCl. Twelve hours after injection, the wet and dry mass of total body and liver of I fetuses significantly exceeded that of controls. At birth (day 21.5), newborn I pups weighed 5.86 +/- .08 g, and controls, 5.48 +/- .05 g, (P less than .001). On day 18, within one hour of injection, fetal plasma insulin concentrations were significantly elevated and remained so for 24 hours. Mothers of I fetuses had significant elevations of plasma insulin at 1, 3, and 6 hours, and they developed transient hypoglycemia. Plasma glucose concentrations in I fetuses were significantly diminished at 1, 3, and 6 hours and then achieved control levels by 12 hours. Fetal hypoglycemia resulted from an apparent direct effect of insulin upon fetal tissue and from the maternal hypoglycemia. Hypoglycemic I fetuses demonstrated a sluggish alpha-cell response; they failed to increase plasma glucagon one hour after insulin injection. Values were significantly increased three hours after injection. At birth, I pups became hypoglycemic relative to controls. This was, in part, due to their significantly elevated plasma insulin concentrations at 120 and 240 minutes (120 minutes, 43.8 +/- 8 v 17.5 +/- 6 microU/mL, P less than .001). Plasma glucagon was significantly increased in I pups at 240 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

The Northwestern University Triplet Study. III: Neonatal outcome.

Limited data suggest that cesarean section (CS) may be the preferred method of delivery for triplets. Despite this, it is also felt that the third triplet is at great risk at delivery. We reviewed our experience of 14 triplet pregnancies at Northwestern University between 1981 and 1985. All deliveries were attended by neonatal teams in sufficient number to resuscitate each infant. Of the 14 pregnancies, two ended in previable loss. Thirty-six infants were born from 12 pregnancies of a mean gestational age of 33 weeks (28-38 weeks). The overall survival was 97.3%. Two women delivered vaginally. While the first was successful, the second resulted in vaginal delivery of the first two triplets followed by emergency CS for the third. That infant had a cord blood pH of 6.96 (BE-19), was resuscitated and survived. All 10 CS were successful. The mean cord blood gas tensions and pH were normal. In addition, Apgar scores, the requirement for mechanical ventilation or supplemental oxygen, and mortality did not differ between the first and third-born triplet. These observations suggest that CS was beneficial. Our very low mortality rate supports the concept that CS delivery and aggressive neonatal resuscitation and therapy greatly enhances survival.

Birth Order↗
PubMed1988

Human placental lactogen administration in the pregnant rat: acceleration of fetal growth.

To determine whether administration of human placental lactogen (hPL) to pregnant rats during late gestation might enhance fetal growth, we implanted osmotically driven minipumps to provide 75 micrograms h PL/24 h on day 14 of the rat's 21.5-day gestation. This substantially increased maternal and fetal plasma hPL concentrations. By day 18, hPL fetuses were significantly heavier and had larger placentas than controls. From this point until term, their rate of growth (1.20 g/24 h) significantly exceeded that of controls (0.95 g/24 h). Birth weights differed significantly (hPL 5.86 +/- 0.08 g; controls 5.20 +/- 0.08 g, p less than 0.001). This increase was due primarily to significant increases in the growth of the liver and carcass. Enhanced glucose availability was in part responsible for this phenomenon inasmuch as plasma glucose concentrations were significantly increased in hPL maternal rats from days 15 to 19. This resulted on days 18 and 19 in significantly increased plasma glucose and insulin concentrations in hPL fetuses. Fetal/maternal glucose ratios did not differ between hPL and control fetuses. Fetal heptic glycogen concentrations were significantly increased on day 18 and 19 but were similar to controls from day 20 until birth. These observations suggest that increased maternal glucose availability with consequent stimulation of fetal insulin secretion accelerated the growth of hPL fetuses. However, maternal and fetal plasma glucose concentrations and fetal plasma insulin and hepatic glycogen concentrations on days 20 and 21 were normal, suggesting that other factors also were responsible for sustaining the accelerated fetal growth on these days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Proposed criteria for referring diabetic retinopathy.

Diabetic retinopathy is a leading preventable cause of blindness in the United States. The primary care nurse practitioner is often confronted with the decision of whether to refer a person with diabetes to an ophthalmologist. Because ophthalmoscopy may be technically difficult with a particular patient, current recommendations are to refer all diabetics. Unfortunately, many studies reveal that this approach is not working. This article defines criteria for the nurse practitioner to determine who is most in need of referral. The tested criteria have a sensitivity of 77 percent and a specificity of 81 percent when compared with ophthalmoscopy. The criteria are based on the results of ophthalmoscopy, duration of diabetes, status of glycemic control, status of achilles tendon reflex, status of serum creatinine, amount of alcohol consumption and the presence of hypertension. Using the criteria is feasible in a clinic or hospital setting. Use of this tool may improve appropriate ophthalmological referral of persons with diabetes.

Adult↗