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Biomedical subjects

M B Resnick

Publications and source records attributed to M B Resnick.

At least 19 recordsLinked to original sources

Changes in survival patterns of very low-birth-weight infants from 1980 to 1993.

OBJECTIVE: To determine changes in survival patterns among very low-birth-weight ( < 1500 g) infants between 1980 and 1993. METHODS: The records of 12,960 infants treated in nine perinatal intensive care centers in Florida were analyzed on the basis of survival (discharged alive from hospital) according to four independent variables: birth weight, race, sex, and transport status. Survival curves were generated using log linear regression techniques for each race by sex by transport status group. RESULTS: Race, sex, and transport status correlated significantly with survival: survival percentages were higher among black infants, female infants, and infants transported to the perinatal intensive care centers than among white infants, male infants, and those admitted initially to the tertiary care centers. After 1985, 95% of neonates with birth weights between 1200 and 1500 g survived. In addition, survival of 500- to 500-g transported black male infants increased from zero to near 80% during the 13-year period; that of 500- to 550-g inborn white female infants rose from 35% to 70%. CONCLUSIONS: These results illustrate the value of taking into account race, sex, and transport status in efforts to understand the contribution that neonatal intensive care of extremely low-birth-weight infants makes to the lowering of infant mortality, and of using multivariable statistical procedures to generate predicted survival probabilities for different subpopulations. These probabilities can be applied to (1) predicting survival for specific subgroups of extremely low-birth-weight infants, and (2) helping physicians develop clinical guidelines for extending care to infants at the threshold of viability.

Birth Weight

Human eosinophils migrate across an intestinal epithelium in response to platelet-activating factor.

BACKGROUND/AIMS: Transmigration of eosinophils across intestinal epithelia occurs in a variety of mucosal inflammatory disorders and results in the formation of crypt abscesses containing eosinophils. However, the conditions required to drive transepithelial migration of eosinophils are not understood. METHODS: This study investigated eosinophil migration across intestinal epithelia using purified eosinophils and confluent monolayers of the human intestinal epithelial cell line T84. RESULTS: Unactivated eosinophils (i.e., no granulocyte/macrophage colony-stimulating factor [GM-CSF] preexposure) did not migrate across T84 monolayers in the presence of transepithelial gradients of C5a, n-formyl-methionyl-leucyl-phenylalanine (fMLP), or platelet-activating factor (PAF). In contrast, activation of eosinophils by coincubation or pretreatment with GM-CSF enabled transepithelial migration in response to PAF but not to C5a or fMLP gradients in a time- and dose-dependent fashion. Specificity was confirmed by both the PAF receptor antagonist WEB-2086 and the PAF enantiomer 2-lyso-beta-acetyl-gamma-O-hexadecyl. Finally, addition of functionally inhibitory monoclonal antibodies to CD11b but not CD11a, very late activation antigen (VLA-4), or intracellular adhesion molecule 1 inhibited eosinophil migration. CONCLUSIONS: These studies establish that physiologically directed migration of eosinophils across model epithelia occurs but that this process is governed by the state of eosinophil activation, the specific chemotactic gradient imposed, and the availability of specific surface integrins to participate in putative eosinophil-epithelial adhesion steps.

Adult

Hepatic adenoma in the pediatric age group. Clinicopathological observations and assessment of cell proliferative activity.

The clinicopathological findings of eight children with hepatic adenoma in the absence of cirrhosis are presented. The lesions ranged in diameter from 0.1 to 14.5 cm. Associated disorders were Fanconi's anemia, type I glycogen storage disease. Hurler's disease, and severe combined immunodeficiency with ADA deficiency. The remaining three children had adenoma without known associated disorders. In the children with glycogenosis and Hurler's disease the adenomas were multiple. Significant dysplasia occurred in the two children with Fanconi's anemia; however, the lesions behaved in a benign fashion--one with regression of the tumor after cessation of androgen therapy and the other with nonrecurrence after complete resection. Proliferating cell nuclear antigen (PCNA) labeling index (LI) of the adenoma arising in patients with Fanconi's anemia was significantly greater than the PCNA-LI of adenoma in the other children (mean 4.1% versus 0.9% of nuclei), approaching the lower end of the spectrum for reported hepatocellular carcinoma cases. We emphasize that the worrisome pathology that may occur in hepatic adenoma in children, particularly with Fanconi's anemia, does not necessarily predict malignant behavior. The association of hepatic adenoma with Hurler's disease or severe combined immunodeficiency has not been reported previously.

Adenoma, Liver Cell

A random coefficient growth curve analysis of mental development in low-birth-weight infants.

In many medical studies, longitudinal data are collected on each of a sample of patients. The objectives of such studies often are: to estimate and test bivariate or multivariate relationships within each of several groups of patients from these repeated measures data; to compare these relationships among groups; and to test for the effects of baseline covariates on the relationships. This paper illustrates the use of statistical methods for growth curve analysis recently proposed by Vonesh and Carter for achieving these goals by relating a measure of preschool cognitive development to age in four race by sex groups of low-birth-weight infants. Significant declines in Bayley's Mental Development Index (MDI) with increasing age were found in all groups. Birth-weight did not significantly influence the rate of decline but did influence the overall level of performance. Even so, in the group most comparable to Bayley's normative population, predicted MDI was near the norm even for extremely low-birth-weight infants (that is, 1000 grams). Although there is some risk of mental deficit associated with prematurity, eventual developmental delays in low-birth-weight infants frequently are acquired with age. The rate of decline in MDI was significantly associated with race and mother's education. Assumptions required for the valid application of these methods are discussed and tested in the setting of this applied problem. The assumptions appeared valid in this application. We conclude with a brief discussion of available alternatives when the assumptions are violated and point to areas for future research.

Age Factors

Educational outcome of neonatal intensive care graduates.

Studies of developmental outcome of neonatal intensive care unit graduates have generally been limited to the first 2 to 3 years of life, with outcome determined by psychometric tests. This study followed neonatal intensive care unit graduates born 1975 through 1983 (n = 457) into the public school system and compared their educational outcomes with those of newborn nursery graduates (n = 656). Outcomes were evaluated by placement in four academic categories: regular classroom, academic problems, speech/language impairment, and major impairment. Educational outcomes for children of both groups were essentially the same. Their placement in the four academic categories were equally affected by nonmedical variables, primarily income (below/above poverty level), race, and sex. Seventy percent of poverty-level children were in one of the three problem categories, compared with 40% of children above poverty level. Neither neonatal intensive care unit treatment nor low birth weight were major predictors of educational outcome. The only clear-cut neonatal intensive care unit effect occurred among children born with sensory or physical impairments. Therefore, in order to reduce poor educational outcomes, follow-up and intervention programs should be targeted primarily to children with diagnosable handicaps and from minority, low-income families.

Child

Effects of birth weight and sociodemographic variables on mental development of neonatal intensive care unit survivors.

Neonatal intensive care unit survivors (N = 494) from 10 tertiary care centers were evaluated over the first 4 to 5 years of life to determine the relative contributions of birth weight and sociodemographic factors to mental development. Six sociodemographic factors were studied: sex, race, family income, and mother's marital status, age, and educational level; the last five factors also are known to be associated with premature birth. Mental development was measured with the Bayley Scales of Infant Development (12 to 24 months) and the Stanford Binet Intelligence Test (4 to 5 years). Each factor's influence was assessed by multivariate analysis. Birth weight had limited long-term implications; at 4 to 5 years, only infants with birth weights less than 1000 gm had significantly lower scores than those in other birth weight categories. Sociodemographic variables had a greater impact on mental development, with age-dependent differences found between nonwhite and white children and between children with mothers of low, medium, and high educational levels.

Adult

Effect of birth weight, race, and sex on survival of low-birth-weight infants in neonatal intensive care.

Survival for low-birth-weight infants has traditionally been analyzed by birth weight categories spanning considerable ranges of weight. We developed a finer description of survival rates to allow estimation of survival percentages for infants of any specific birth weight between 500 and 2500 gm. Our sample consisted of 16,183 infants treated in tertiary neonatal intensive care between 1980 and 1987. Their survival data were analyzed by 50 gm increments between 500 and 2500 gm, and a continuous survival curve was constructed by log linear regression methods. Mortality differences between males and females and blacks and whites were analyzed. Survival for females was higher than males between 500 and 1500 gm and higher for blacks than whites between 650 and 1500 gm. Between 1500 and 2500 gm, no significant effects of birth weight, race, or sex were observed, with survival remaining stable at approximately 95% across all combinations of variables.

Birth Weight

Predictive value of Apgar scores for developmental outcome in premature infants.

For more than two decades, Apgar scores have been used to predict developmental outcome in newborns. However, most studies have used full-term babies for their data base, and the predictive value of Apgar scores for low birthweight infants has remained unclear. This study was designed to provide a data base for premature infants, demonstrating to what degree Apgar scores predict developmental outcome. We tested Apgar scores alone and in combination with two other easily quantified variables, birthweight and gestational age, as predictors of risk for 256 infants weighing less than 1800 gm at birth. Although significant correlations existed between Apgar scores and Bayley Mental and Psychomotor Developmental Indices, multiple regression analyses demonstrated that these relationships were not significant independent of birthweight and gestational age. That is, after controlling for birthweight and gestational age, Apgar scores did not predict morbidity in low birthweight infants and should not be used to provide a developmental prognosis.

Apgar Score

Developmental intervention program for high-risk premature infants: effects on development and parent-infant interactions.

Developmental follow-up studies have documented that low birth weight infants are at high risk for mental and physical disabilities, despite recent advances in neonatal intensive care. Moreover, parent-infant bonding is hampered by the barriers created by technical equipment. This study evaluated a program of hospital and home-based developmental interventions designed to enhance the development of high-risk, preterm infants and the quality of communication between infants and their caregivers. Treatment and contrast groups consisted of 41 premature infants weighing less than 1800 g at birth. Treatment took a preventive approach, consisting of daily multimodal interventions in-hospital and twice-monthly interventions by child development specialists in the child's home, through 12 months adjusted age. Infants in the contrast group received traditional, remedially oriented care. The Bayley Scales of Infant Development were used to measure mental and psychomotor development, and the Greenspan-Lieberman Observations System (GLOS) was used to analyze the behavioral characteristics of infant-caregiver interactions. Developmental interventions had positive, significant effects on mental development and on the quality of caregiver-infant interactions. Changes in mental development were not independent of changes in the GLOS.

Cognition

Prospective pricing model for neonatologists and obstetricians in tertiary care centers.

According to the new federal diagnosis-related group (DRG) system, hospitals are reimbursed fixed sums based on discharge diagnoses, rather than variable sums that depend on specific goods and services consumed and number of days hospitalized. The government is now exploring DRGs as a potential mechanism for reimbursing physicians. In Florida, two DRG-type reimbursement systems were developed for neonatal and obstetrical hospitalizations in tertiary care settings, as departures from the federal DRG system. Called neonatal care groups (NCGs) and obstetrical care groups (OBCGs), both classification systems predicted hospital charges in these settings more accurately than did federal DRGs. The feasibility of a prospective pricing system for neonatologists and obstetricians based on NCGs and OBCGs was investigated. The data showed that neonatologists' charges had a high correlation with hospital charges (r = .90) and that increasing levels of intensity of care as defined by the NCGs were reflected by consistent increases in reimbursement to neonatologists. If the NCG system were to be applied, neonatologists would receive compensation equivalent to that which they currently earn according to the fee-for-service system. In contrast, obstetricians' charges bore almost no relationship to hospital charges. However, modest differences in obstetrician's charges did emerge as a reflection of number of complications, which are incorporated into the OBCG categories; this suggests that a reimbursement system based on hospital OBCG categories might be applied to obstetricians.

Diagnosis-Related Groups

Prospective pricing system by diagnosis-related groups: comparison of federal diagnosis-related groups with high-risk obstetric care groups.

Of 468 diagnosis-related groups identified by the federal government for Medicaid reimbursement, 15 are related to obstetric hospital care. Each diagnosis-related group is considered a distinct group in which cases are homogeneous with respect to resource consumption. Because the diagnosis-related group system is based primarily on data from community and secondary care hospitals, it does not differentiate sufficiently among high-risk obstetric patients seen at tertiary care institutions, such as Florida's Regional Perinatal Intensive Care Centers. We developed an alternative scheme for diagnosis-related groups, called obstetric care groups, using the federal diagnosis-related groups as the model from which to depart. Data collected for 4192 women during a 2 1/2-year period indicate that obstetric care groups provide more homogeneous groups than diagnosis-related groups for our population of high-risk patients. The obstetric care groups differentiate between no complications, one complication, and two or more complications, while the diagnosis-related groups differentiate only between no complications and one or more complications. Also, complications for obstetric care groups are based on only 19 diagnoses that contribute significantly to resource consumption, while the list of possible complications exceeds 200 for diagnosis-related groups. Although the obstetric care group classification system is simpler than that for diagnosis-related groups, it results in a more accurate reimbursement of hospitalization charges for high-risk obstetric care.

Diagnosis-Related Groups

The relationship of Apgar scores, gestational age, and birthweight to survival of low-birthweight infants.

While Apgar scores provide a valid prediction of mortality in term infants (primarily reflecting asphyxia), intervening variables in premature newborns complicate interpretation. Physiologic states normal to preterm infants (such as, decreased muscle tone) can depress scores but may not influence survival significantly. Therefore the relationship between Apgar scores and survival in term and preterm infants differs. Because of the paucity of studies on preterm infants, we tested Apgar scores, as well as birthweight and gestational age, as outcome predictors in 748 low-birthweight infants (500-1800 gm). Our purpose was to assess the relationship between 1- and 5-minute Apgar scores and survival, and to evaluate all combinations of the four variables as outcome predictors. Univariate analysis showed a significant relationship between each of the four variables and survival; however, no single variable accounted for more than 32% of the variance in outcome, thus no single factor could be invoked as the major determinant of survival. Logistic regression analyses demonstrated the interrelationships of the four variables to survival. While both Apgar scores were related to survival, independent of the effects of birthweight and gestational age, they were slightly less predictive than either of these variables alone. However, when 1- and 5-minute Apgar scores were combined with gestational age, the predictive value was slightly better than any of the four variables alone or in other possible combinations.

Apgar Score

Developmental intervention for low birth weight infants: improved early development outcome.

This prospective longitudinal study was designed to evaluate the effects of a multidisciplinary infant development program (IDP) on the mental and physical development of low birth weight infants (less than 1,800 g). Infants in the neonatal intensive care were randomly assigned to the IDP or to traditional care (control group). IDP infants received developmental interventions in the hospital and at home through the first 2 years of life. Counseling and parenting education were provided to their parents during this same period. The control group received all the postnatal care and referrals customarily given in traditional care. Both IDP and control infants were enrolled in an independent follow-up program, which used the Bayley Scales of Infant Development in a blind evaluation design. The IDP group had a significantly lower incidence of developmental delay (P less than .05) and scored significantly higher than the control group (P less than .05) on mean mental and physical indices at 12 and 24 months of adjusted age.

Counseling

Prospective pricing system for tertiary neonatal intensive care.

This study assessed the potential impact of the federal neonatal diagnosis-related group (DRG) pricing system upon reimbursement to a state neonatal intensive care program. Data for length of intensive care unit stay, procedures, hospital charges, and audited cost reports from the state of Florida's ten regional neonatal intensive care centers were analyzed for 8,492 neonates whose charges totaled $118 million. Mean lengths of stay in these tertiary care centers were substantially longer than those reported for the federal DRGs, which were based on community hospital data. If federal DRG-based reimbursement to hospitals were implemented in Florida's perinatal intensive care program, compensation would range from 9% to 56% of actual hospital care charges. Federal DRG price rates were not predictive of hospital charges. Only 16% of the total variation in hospital charges was explained by differences among federal DRG rates (R2 = .16). Analysis of data by major determinants of resource consumption provided groups more homogeneous with respect to hospital charges and, hence, cost. Therefore, we developed a prospective pricing system that used modifications of federal newborn DRG system. These modifications resulted in a threefold increase in R2 (.52). Our proposed system permits prediction of cost and reimbursement for infants by three criteria: birth weight, need for mechanical ventilation and/or major surgery, and survival status and length of survival for those who die.

Analysis of Variance

Characteristics, mortality, and outcome of higher-birth weight infants who require intensive care.

The improved outcome of small infants who have received intensive care is well documented; however, the mortality and morbidity of infants weighing greater than or equal to 2500 gm who require intensive care have not been emphasized. During a 2-year period these infants accounted for 41% of admissions and 34% of all deaths in our nursery. The most common diagnoses were pulmonary disease (32%), asphyxia (22%), congenital anomalies (18%), infant of diabetic mother (10%), hematologic disease (9%), and infection (4%). Mortality was 11% with 50% of the deaths from lethal malformations, 26% from asphyxia, 13% from infection, and 11% from miscellaneous causes. One half of the deaths were potentially preventable. According to developmental follow-up, over 90% of the survivors were developing normally. Thus, while outcome for survivors is usually good, mortality remains excessively high. This large and understudied group of infants requires increased investigative emphasis.

Birth Weight