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Biomedical subjects

J W Collins

Publications and source records attributed to J W Collins.

54 records · Page 3Linked to original sources
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↗
PubMed1984

Congenital tear duct obstruction.

Congenital nasolacrimal duct obstruction is a classic condition that has been well investigated and is readily identified. The suggested sequence of treatment includes massage, irrigation, probing, insertion of a silicone stent and, finally, dacryocystorhinostomy. Because of the relatively frequent occurrence of duct obstruction in normal infants, family physicians need to be familiar with its diagnosis and treatment. If problems still exist after an adequate trial of conservative treatment, referral before six months of age is suggested.

Fluoresceins↗
PubMed1983

McCord procedure for ectropion repair.

The McCord technique of ectropion repair was used on 85 eyelids of 77 patients who have been observed for six to 34 months. In each instance the ectropion was corrected by resecting part of the stretched lateral canthal tendon and reattaching the tarsus to the lateral orbital rim with a permanent suture. The incision at the lateral canthus avoids lid notching, trichiasis, corneal irritation, and the added stress on the lateral canthal tendon that may occur with conventional wedge sections. The lid position was revised in six patients. A lateral canthal granuloma developed in four patients. One patient had late infection from the permanent stitch. This procedure is particularly useful for patients with ectropion who have an artificial eye or for ectropion after blepharoplasty. Additional steps may be added for more complicated cases, such as skin grafting for cicatricial ectropion or reattachment of the lower lid retractors for tarsal ectropion.

Ectropion↗
PubMed1983

Combined procedure for senile entropion.

Entropion of the lower eyelid was corrected in 26 eyelids of 21 patients. All patients were found to have a disinsertion of the capsulopalpebral fascia, but not Muller's muscle layer, of the lower eyelid retractors. All cases were repaired by reattaching the anterior edge of the capsulopalpebral fascia to the inferior edge of the lower tarsus combined with A horizontal eyelid tightening procedure performed at the lateral canthus. With follow-up of six to 32 months, no cases of entropion have recurred. We have found a combined procedure of horizontal eyelid tightening and repair of the capsulopalpebral fascia gives best long-term results.

Entropion↗
PubMed1982

Basal cell carcinoma of the eyelid as an indicator of multifocal malignancy.

Of 30 consecutive patients with ocular adnexal basal cell carcinoma, 18 (60%) had at least one additional unsuspected foci of basal cell carcinoma. The patients most likely to have additional basal cell skin cancer were women, those with previous basal cell carcinoma, and those whose eyelid lesions were recurrent, located at the medial canthus, or of the sclerosing cell type. Using a slit lamp helped us to identify suspicious lesions on the face, but we often required the assistance of a dermatologist to diagnose sclerosing lesions. Comprehensive treatment of basal cell carcinomas should include eradication of the initial lesion, examination for coexisting lesions, prophylaxis for solar exposure, and follow-up examinations for recurrent or new lesions.

Adult↗
PubMed1982

Pseudopterygium from exposure to selenium dioxide.

Pseudopterygium and symblepharon developed in a patient exposed to selenium dioxide gas. Previously, a case of pseudopterygium had been reported after exposure to seleniferous acid. This cicatricial condition can be distinguished from the pterygium by eccentric location, the lid scarring, and the absence of pterygium in the other eye. This pseudopterygium recurred despite 11 operations. Full-thickness mucous membrane grafts wee used to separate the lid from the globe.

Adult↗
PubMedDate not supplied

Power determination for geographically clustered data using generalized estimating equations.

Study designs in public health research often require the estimation of intervention effects that have been applied to a cluster of subjects in a common geographic area, rather than randomly assigned to individual subjects, and where the outcome is dichotomous. Statistical methods that account for the intracluster correlation of measurements must be used or the standard errors of regression coefficients will be under-estimated. Generalized estimating equations (GEE) can be used to account for this correlation, although there are no straightforward methods to determine sample-size requirements for adequate power. A simulation study was performed to calculate power in a GEE model for a proposed study of the effect of an intervention, designed to reduce lower-back injuries among nursing personnel employed in nursing homes. Nursing homes will be randomly assigned to either an intervention or control group and all employees within a nursing home will be treated alike. Historical injury data indicates that the baseline-injury risk for each home can be reasonably modelled using a beta distribution. It is assumed that the risk for any individual nurse within a nursing home follows a Bernoulli probability distribution expressed as a logit function of fixed covariates, which have values of odds ratios determined from previous studies which represent characteristics of the study population, and a random-intercept term which is specific for each home. Results indicate that failure to account for intracluster correlation can lead to overestimates of power as well as inflation of type I error by as much as 20 per cent. Although the GEE method accounted for the intracluster correlation when present, estimates of the intracluster correlation were negatively biased when no intracluster correlation was present. In addition, and possibly related to the negatively biased estimates of intracluster correlation, we also found inflated type I error estimates from the GEE method.

Algorithms↗
PubMedDate not supplied

Racial differences in post-neonatal mortality in Chicago: what risk factors explain the black infant's disadvantage?

OBJECTIVES: To investigate the extent to which the place of residence affects the black to white differential in post-neonatal (28-365 days) mortality, we performed a univariate analysis and multivariate logistic regression of the 1982-1983 Illinois vital records. Chicago Police violent crime information and 1980 US Census income data. METHODS: Four environmental predictors of post-neonatal death were examined: a median family income of < $10,000 per year, a poverty prevalence of > 50%, violent crime rates of > 11/1000 and limited community access to primary medical care based on physician supply ratios. RESULTS: The post-neonatal mortality rate of black (n = 50,765) infants was three times that of white (n = 50,690) infants: 10/1000 versus 3/1000, respectively. Thirty-six percent of the white infants had none of the environmental risk factors, whereas only 13% of the black infants had none of the risk factors. For black infants, the presence of any one factor was associated with a slightly increased risk of post-neonatal mortality (9/1000 as compared to 7/1000 with no risk factors), whereas the presence of two or more risk factors was associated with a higher risk (11/1000). When the number of these environmental risk factors were taken into account, the OR for black infants declined from 3.0 (95% CI 2.5-3.6) to 1.7 (95% CI 1.5-1.9). When the differences in maternal age, education, marital status and infant birth weight were also taken into account the odds ratio of post-neonatal death for blacks was 1.5 (95% CI 1.3-1.7). CONCLUSIONS: We conclude that a substantial proportion of the black to white difference in post-neonatal mortality is associated with specific environmental conditions.

Black or African American↗
PubMedDate not supplied

Postterm delivery among African Americans, Mexican Americans and Whites in Chicago.

OBJECTIVES: The purpose of the present study was to examine the effect of individual-level and community-level risk factors on the postterm delivery rates of infants born to African-American, Mexican-American, and non-Latino White mothers; and to compare postterm delivery rates between these ethnic groups. DESIGN: This is a population-based study. METHODS: We performed stratified and multivariate logistic regression analyses on a linked dataset of 1992-1995 Illinois vital records, 1990 United States Census income data, and 1995 Chicago Department of Public Health information. Communities with one or more high-risk characteristics (low median family income or high rates of unemployment, homicide or lead poisoning) were classified as impoverished. RESULTS: In Chicago, African Americans (N = 85,978) had a postterm rate of 4.3/1,000 and Mexican Americans (N = 47,266) had a postterm rate of 3.6/1,000, compared to 2.3/1,000 for non-Latino Whites (N = 48,601); relative risk (ninety-five percent confidence interval) = 1.9 (1.5-2.3) and 1.6 (1.2-2.0), respectively. Maternal age, education, marital status, parity, and prenatal care usage were associated with ethnic group-specific postterm delivery rates. In a multivariate logistic regression model for non-impoverished mothers, the adjusted odds ratios of postterm delivery for African Americans and Mexican Americans were 1.0 (0.5-3.2) and 1.0 (0.6-1.7), respectively. CONCLUSIONS: We conclude that African Americans and Mexican Americans have greater postterm delivery rates than do Whites; however, commonly cited individual and community-level risk factors account for most of the disparity.

Adult↗
PubMedDate not supplied

The efficacy of training for occupational injury control.

Fifty years after reports that training enhances workplace safety began to appear in the literature, training continues to be considered a practical approach to injury prevention. However, data suggest that workplace training is not commonplace. Studies of the effectiveness of training are reviewed, and successful components of training programs are described.

Accidents, Occupational↗