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Biomedical subjects

M K Miller

Publications and source records attributed to M K Miller.

At least 37 records · Page 2Linked to original sources
PubMed1998

Norplant selection and satisfaction among low-income women.

OBJECTIVES: This study examined correlates of Norplant selection and satisfaction among low-income women. METHODS: Interviews were completed in family planning clinics in 4 Florida counties with 1152 Norplant users and 1268 nonusers, with follow-up interviews with a subsample up to 1 year later. Logistic regression models estimated the associations of socio-demographic and medical characteristics with Norplant selection and method satisfaction. RESULTS: Odds ratios for Norplant selection were significantly greater among women who planned to have children in 5 or more years, those who were "offered" Norplant, those who lived in Palm Beach County, those who were using drugs, and those who were Medicaid clients. Women younger than 17 and those who learned about Norplant from a friend were twice as likely as others to select Norplant. Ninety-two percent of Norplant users were satisfied with the method; women with side effects and those who felt pressure to select a method were significantly less likely than others to be satisfied. CONCLUSIONS: Norplant provides an acceptable and satisfying method of birth control for many low-income women. Proper counseling about all methods of birth control and about Norplant's side effects remains critical to the appropriate delivery of this method.

Adolescent↗
PubMed1997

The role of race and residence in determining stage at diagnosis of breast cancer.

Breast cancer kills more than 46,000 women each year. Previous research has found that minorities and those who reside in geographically remote settings are particularly vulnerable. However, virtually no research has been done on the potential "double jeopardy" faced by rural minority women. This research examines (1) the extent to which racial and residential differences contribute to differences in stage at diagnosis; (2) the existence of an interaction between race and residence, which may place black rural women at greater risk; and (3) the influence of both individual and structural characteristics on racial and residential differences. The findings indicate that rural black women are diagnosed with breast cancer much later than are black urban women or whites of either residence. A number of individual and structural variables were influential in predicting stage at diagnosis, yet none of these accounted entirely for racial differences.

Adult↗
PubMed1996

Mature micromegakaryocytes: an unusual developmental pattern in term infants.

We sought to gain perspective on platelet production in the fetus and the newborn by counting and characterizing megakaryocytes from available cord blood. Elutriation was used to isolate circulating megakaryocytes from umbilical arteries and veins obtained at scheduled caesarean sections of nine normal term fetuses. Megakaryocytes were identified by established criteria, their diameters measured, and maturation stages recorded. Large numbers of megakaryocytes, mostly mature, were found in both the umbilical arteries and veins, many times more than previously observed circulating in adult blood. In term infants more than a third of the mature megakaryocytes had unusually decreased nuclear lobation and were dwarf cells with diameters as small as 13 microns, which we considered to be micromegakaryocytes. The atypicality of these small but mature cells is seen as merely a leftward skewing in the development of megakaryocyte ploidies. We believe that in normal fetuses the extent of megakaryocyte ploidization and development is distinctive and probably regulated differently to the adult pattern.

Cell Nucleus↗
PubMed1996

The interactive effects of race and ethnicity and mother's residence on the adequacy of prenatal care.

Adequate prenatal care is known to reduce the risks of low birth weight and neonatal death, yet nearly one quarter of all women giving birth in the United States receive delayed, inadequate or no prenatal care. This suboptimal use of prenatal care has contributed to rates of low birth weight and neonatal mortality higher than those in most other industrialized nations. This paper examines the relationships among race/ethnicity, residence, maternal sociodemographic and medical risk characteristics, and use of prenatal care in the United States. Using data from the National Maternal and Infant Health Survey, this study found important differences in prenatal care use by race/ethnicity and residence, as well as interactive effects of these variables. Single marital status, nonmetropolitan residence, poverty, low level of education, and no insurance were more strongly associated with inadequate prenatal care for whites and Hispanics than for blacks. Nonmetropolitan residents were more likely to receive inadequate care, regardless of race/ethnicity or sociodemographic characteristics. Predicted probabilities of prenatal care use by race/ethnicity and residence showed that, regardless of risk, nonmetropolitan Hispanic women had the highest probability of obtaining inadequate prenatal care. Results highlight the continued importance of race/ethnicity and rural residence in determining prenatal care use and the need to design interventions targeted to these populations.

Black or African American↗
PubMed1996

Racial differences in adolescent drug use: the impact of religion.

Contrary to popular stereotypes, current studies of adolescent populations suggest that Black teens are less likely to use illicit drugs than are White teens. This study investigates the extent to which differences in religiosity are responsible for racial differences in drug use. Using data from a national survey of United States high school seniors, our results indicate that religion does provide some protection from drug use by adolescents. However, religiosity has less of an impact on the drug use of Black adolescents, perhaps as a result of the diverse roles of the Black church.

Adolescent↗
PubMed1995

Frequency and risk factors for voice problems in teachers of singing and control subjects.

Using a questionnaire format, 125 teachers of singing and 49 control subjects indicated whether they had a current or past voice problem, and provided information about their demographic characteristics, voice use patterns, and medication use. The results revealed similar rates of current voice problems reported by the two subject groups. However, teachers of singing were considerably more likely to report ever having had a voice problem than controls (64 vs. 33%). Risk factors were similar for the two groups. Dehydrating medications and a report of a past voice problem both increased the likelihood of perceiving a current problem, by a factor of three and five, respectively. Females were twice as likely to report a past voice problem as males, and younger subjects were slightly more likely to report a past problem as compared with older subjects. The implications of the findings are discussed from a theoretical as well as pragmatic perspective.

Adult↗
PubMed1995

Prenatal care use in nonmetropolitan and metropolitan America: racial/ethnic differences.

Pregnant women in nonmetropolitan communities are believed to use prenatal care services at lower rates than are metropolitan residents due to higher levels of poverty, lower levels of insurance coverage, and declining numbers of local hospitals and physicians. Yet scarce data exist on actual patterns of prenatal care use in nonmetropolitan areas. This study provides national estimates of prenatal care use among African American, White, and Hispanic women who delivered in 1988 in non-metropolitan and metropolitan areas of the United States. This study finds that nonmetropolitan residents are no more likely than metropolitan residents to go without care, to enter care late, or to make fewer visits. Nonmetropolitan residents are more likely to receive "inadequate" prenatal care as measured by the Kotelchuck Adequacy of Prenatal Care Utilization Index, with Hispanic residents having the highest rates of inadequate care. These findings are consistent with recent state-level reports, and they suggest the need to target prenatal care policies for populations in greatest need.

Ethnicity↗
PubMed1995

Variations in rural hospital costs: effects of market concentration and location.

This article explores two neglected questions: (1) Does the relationship between hospital concentration and costs vary between urban and rural markets? and (2) Do hospital costs in non-metropolitan areas vary with rurality? Covariance model results using 1992 data reveal that: (1) Although metropolitan and urban markets exhibit a negative relationship between hospital average costs and market concentration, non-metropolitan and rural markets fail to exhibit any relationship between costs and concentration; and (2) among non-metropolitan hospitals, only hospitals located in single-hospital communities have lower costs than their counterparts in multiple-hospital communities, once other factors are held constant.

Catchment Area, Health↗
PubMed1994

The triple-helical region of human type XIX collagen consists of multiple collagenous subdomains and exhibits limited sequence homology to alpha 1(XVI).

We previously isolated a clone from a human rhabdomyosarcoma (RH) cDNA library coding for a collagen chain different from those constituting the 18 reported types (Myers, J. C., Sun, M. J., D'Ippolito, J. A., Jabs, E. W., Neilson, E. G., and Dion, A. S. (1993) Gene (Amst.) 123, 211-217). The sequence translated to a 186-amino acid noncollagenous region, a 524-residue three-subdomain collagenous region, and a presumed 8-amino acid COOH-terminal peptide. To further elucidate the primary structure of this collagen, we have now determined the sequence of additional cDNA clones. Overlapping 3' clones, found to diverge exactly where the noncollagenous 8-residue COOH sequence began, encode two additional collagenous subdomains of 168 and 70 residues and a 19-residue COOH-terminal peptide. Analysis of genomic DNA spanning the region in question revealed several 45- and 51-base pair exons linked by 4 introns totaling over 5 kilobases (kb). A 2-kb intron, absent from the clones coding for the extended collagenous region, was used in Northern blot hybridization to detect an apparently prevalent splicing intermediate 2 kb larger than the major 12.4-kb RH transcript. Therefore, the triple-helical region of this collagen chain is likely to be composed of 832 amino acids divided into five collagenous subdomains separated by 20-44 residue interruptions. Two interruptions are similar in sequence and position to those located in the type XVI chain. Furthermore, the arrangement of 2 cysteines near the COOH terminus and two imperfections in collagenous subdomain 1 are conserved in the related subclass composed of type IX, XII, XIV, and XVI collagens. However, in contrast to the COOH-terminal interchain bridging in this latter collagen group, molecular modeling strongly predicts that the cysteines in RH collagen participate in intrachain disulfide bonds. Taken together, the data clearly show that RH collagen does not represent another chain of one of the known collagen types. We propose that it be designated the alpha 1 chain of type XIX collagen.

Amino Acid Sequence↗
PubMed1993

Expression of glycosylated and nonglycosylated human transferrin in mammalian cells. Characterization of the recombinant proteins with comparison to three commercially available transferrins.

The coding sequence for human serum transferrin was assembled from restriction fragments derived from a full-length cDNA clone isolated from a human liver cDNA library. The assembled clone was inserted into the expression vector pNUT and stably transfected into transformed baby hamster kidney (BHK) cells, leading to secretion of up to 125 mg/L recombinant protein into the tissue culture medium. As judged by mobility on NaDodSO4-PAGE, immunoreactivity, spectral properties (indicative of correct folding and iron binding), and the ability to bind to receptors on a human cell line, initial studies showed that the recombinant transferrin, is identical to three commercial human serum transferrin samples. Electrospray mass spectrometry (ESMS), anion-exchange chromatography, and urea gel analysis showed that the recombinant protein has an extremely complex carbohydrate pattern with 16 separate masses ranging from 78,833 to 80,802 daltons. Mutation of the two asparagine carbohydrate linkage sites to aspartic acid residues led to the expression and secretion of up to 25 mg/L nonglycosylated transferrin. ESMS, anion-exchange chromatography, and urea gel analysis showed a single molecular species that was consistent with the expected theoretical mass of 75,143 daltons. In equilibrium binding experiments, the nonglycosylated mutant bound to HeLa S3 cells with the same avidity and to the same extent as the glycosylated protein and the three commercial samples. These studies demonstrate conclusively that carbohydrate has no role in this function.

Animals↗
PubMed1993

Consequences of differential residence designations for rural health policy research: the case of infant mortality.

In 1991, members of the rural caucus proposed numerous bills designed to attenuate the rural-urban differences in health care delivery and health status. Implicit in the legislative process is the assumption that "rural America" differs systematically from "urban America." However, research has consistently demonstrated that there is not a single rural America but rather, those areas outside of the major metropolitan areas represent a complex mosaic of varying social and environmental settings. Rural communities differ in meaningful ways along a number of socioenvironmental parameters, and accordingly, health status indicators also differ across rural communities. Thus, health outcome statistics averaged across rural communities will often mask important disparities experienced by certain population groups. Policies based on these aggregate indicators may overlook the needs of the most disadvantaged. While a number of measures of rurality have emerged in the last decade, much of the information presented to policy-makers is either too aggregated (i.e., metropolitan-nonmetropolitan) to identify important differences across the range of communities, or it is gathered in agency-specific categories that are not comparable. The central question under examination in the current context is the possibility of distorting the picture of infant health status by aggregating the diverse rural locales of the United States. Empirical results indicate that when considering infant mortality, any rural disadvantage is contingent upon how 'rural' and 'urban' have been defined. Further, the results indicate that conclusions must be conditioned on other important sociodemographic parameters such as region of the country and race.

Black or African American↗
PubMed1993

The effectiveness of Florida's "Improved Pregnancy Outcome" program.

The development of a national program to assure access to prenatal care for all women, regardless of income, is believed to be an effective means of reducing low birthweight and neonatal mortality in the U.S. Yet scarce empirical evidence concerning the effectiveness of large-scale prenatal care programs is available. This paper summarizes an evaluation of a statewide public prenatal care program which grew out of the federal Improved Pregnancy Outcome (IPO) project. Using linked birth and infant death-certificate data, and IPO program records from a four-year period (1985-1988), this study compares the neonatal mortality rates of participants of Florida's IPO program with those of a matched comparison group. The results indicate an inverse relationship between IPO participation and the risk of neonatal mortality in a low-income population. These findings suggest that large-scale prenatal care programs can be effective in improving birth outcomes.

Adolescent↗
PubMed1991

Uncompensated care provided by private practice physicians in Florida.

While a great deal of attention has been paid in recent years to establishing the magnitude and characteristics of uncompensated care in hospitals, comparatively little research has been undertaken to study physician uncompensated care. This article reports the results of a prospective patient-specific study of uncompensated care in Florida. Of 4,042 cases examined, 26.2 percent had charges voluntarily reduced below the usual and customary charge at the time of service. However, only 13.5 percent of those reductions were attributed to charity. Overall, 10.4 percent of the total billed amount was left unresolved. When payment source was considered, it was found that self-pay patients accounted for 30.6 percent of the cases but accounted for 52.0 percent of the unresolved amounts. Further analysis indicated that the self-pay patients were 35.5 times more likely to leave an outstanding balance than individuals with some type of insurance coverage. Odds of unresolved balances were also calculated as a function of income, specialty type, practice size, and type of visit.

Adolescent↗
PubMed1990

Extracorporeal membrane oxygenation therapy in neonates with septic shock.

Neonatal septic shock has significant morbidity and mortality with current therapeutic measures. At Children's National Medical Center, from June 1984 to October 1986, 10 of 100 patients treated with venoarterial extracorporeal membrane oxygenation (ECMO) had a documented diagnosis of septic shock. All of these infants fulfilled criteria consistent with 80% mortality using conventional intensive medical management. However, the survival rate for the septic neonates in this study was 100%. Compared with other groups of infants treated with ECMO, these septic neonates required significantly more ventilatory support after ECMO and had a higher incidence of chronic lung disease (30% v 12%). The septic neonates were also at higher risk for intracranial hemorrhage than the other infants treated with ECMO (40% v 26%). The necessity for prolonged intubation after ECMO for patients with septic shock suggests that this condition may be associated with additional structural damage not seen with meconium aspiration syndrome or respiratory distress syndrome. Nevertheless, for neonatal patients with septic shock unresponsive to conventional medical management, ECMO must be considered a viable alternative treatment.

Cerebral Hemorrhage↗
PubMed1990

Determinants of primary caregiver stress and burden: area of residence and the caregiving networks of frail elders.

This research examines the association among characteristics of the caregiving network, primary caregiver stress and burden, and area of residence. The purpose is two-fold: to determine whether the structure of the relationship between the caregiving network, and stress and burden is uniform across rural, small city, and urban samples; and, to assess whether stress and burden are explained by a similar set of variables within area of residence categories. The data are drawn from a matched sample of 1,388 impaired elders and their primary caregivers from the 1982 National Long-Term Care Survey and the National Survey of Informal Caregivers. In general, the analysis shows that several characteristics of the care-receiver and the primary caregiver have a differential effect on stress and burden across residential categories, and that, within rural, small city, and urban samples, the determinants of stress and burden are not homogeneous. When the frail elder is able to reciprocate by doing chores, babysitting, or providing some other type of assistance for the primary caregiver, however, both stress and burden are reduced in all three residential categories. Similarly, the increased provision of assistance with instrumental activities of daily living by the primary caregiver uniformly increases stress and burden. These findings suggest that interventions designed to alleviate primary caregiver stress and burden may be able to have some common components, but may also need to be tailored in some ways to specific residential environments.

Activities of Daily Living↗