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PubMedDate not supplied

Differences in hypertension prevalence among U.S. black and white women of childbearing age.

Hypertension and its sequelae complicate pregnancy and can result in poor perinatal outcomes. Overall, U.S. blacks are more likely to be hypertensive than whites, but the degree to which this is true among women of childbearing age (including teenagers) is unknown. Using data from the second National Health and Nutrition Examination Survey (NHANES II), the authors describe hypertension prevalence rates for 422 black and 2,700 white reproductive-age women. The authors present observed data and also predicted prevalence rates derived by modeling the odds of hypertension using logistic regression statistical techniques. They find that black-white differences in hypertension prevalence are negligible among teenagers, but they are pronounced in the older reproductive ages. They estimate that twice the proportion of black women relative to white are hypertensive during pregnancy. Their results suggest that differential rates of hypertension between black and white women may contribute to the persistent excess infant mortality among blacks, but conclusive results cannot be determined from these data. These data are also valuable for the design and evaluation of screening, intervention, and followup programs for hypertensive disease among young women.

Adolescent↗

PubMed1990

[Evaluation of Pen meters for blood glucose analysis in ambulatory diabetics].

A recently developed pen-sized glucose meter using direct electrochemistry to give an automatic digital readout of the blood glucose concentration was evaluated in 10 diabetic outpatients using it at home for 8 weeks. The pen-meter readings were compared with whole blood glucose results obtained in the laboratory on an ACP-glucose analyzer. Regression statistics with slope and intercept, respectively, were 0.96% and 0.39 mmol/l (correlation coefficient r = 0.95). During the first two weeks, 53% of the patient-performed pen-meter readings differed by more than 10% from the laboratory values, during week 7 and 8 only 34%. Patients' replies to a questionnaire revealed that all welcomed the pen-meter as a fast, easy to use and highly portable device for self monitoring of blood glucose.

Blood Glucose Self-Monitoring↗

PubMed1989

[Correlation of clinical course with MRI findings in olivo-pontocerebellar atrophy and late-cortical cerebellar atrophy].

We quantitatively analyzed 1.5 T MRI in 36 cases of sporadic spinocerebellar degeneration (SCD) and 30 control cases without intracranial lesions, using graphic analyzer. SCD consisted of 21 olivo-ponto-cerebellar atrophy (OPCA) and 15 late cortical cerebellar atrophy (LCCA). There was negative correlation between vermian size and the duration of illness both in OPCA (r = 0.8960, p less than 0.001) and LCCA (r = 0.7756, p less than 0.01), but the progression rate in OPCA was three times greater than that in LCCA. LCCA was suggested the preclinical vermian atrophy by the statistical regression study. In OPCA, the duration of illness also revealed significant correlations with atrophy of ventral pons (r = 0.8308, p less than 0.001) and also cerebellar hemisphere (medial hemisphere; r = 0.7278, p less than 0.001. lateral hemisphere; r = 0.6039, p less than 0.01). OPCA showed diffuse atrophy of cerebellar hemisphere, whereas LCCA showed medial dominant atrophy. OPCA demonstrated significant correlation between the fourth ventricle dilatation and the duration of illness (r = 0.6005, p less than 0.01). A discriminant study significantly separated OPCA, LCCA and control each other by sizes of ventral pons and cerebellar vermis (p less than 0.001). In T2 weighted MRI, 10 cases out of 14 LCCA did not show hypointensity in dentate nucleus in spite of normal appearance in the other portions usually decreased intensity. The dentate nucleus of OPCA showed a significant atrophy. The incidence of putaminal hypointensity in OPCA was significantly greater than that of control group (chi-square = 6.476, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMedDate not supplied

The effects of breastfeeding and birth spacing on child survival in China.

Using data from the In-depth Fertility Survey, conducted in Shanghai Municipality and Shaanxi Province, People's Republic of China, in April 1985, this study shows that breastfeeding and birth spacing have significant effects on child survival in Shaanxi, but not in Shanghai (controlling for potential confounding factors and reverse causality). The effect of breastfeeding decreases with age. Introducing proper supplemental food is very important for child survival in Shaanxi, where a high proportion of children are breastfed exclusively for much too long, sometimes up to nine months. An increase in the length of the previous birth interval improves child survival in Shaanxi significantly, especially for high-order children, and the first child has the highest survivorship in both Shanghai and Shaanxi. The effects of subsequent birth intervals are statistically significant in Shaanxi, but have a small actual impact on child survival in the first few years of life, since the arrival of a sibling does not affect the index child's risk of dying in the first few months of life, when the mortality rate is extremely high.

Age Factors↗

PubMed1989

[A mathematical analysis of the interconnection between the titer and avidity of antibodies].

The study made by the methods of mathematical statistics (regression and dispersion analysis) and the calculation of correlative relationship have shown that the titers of antibodies and their avidity in immune rabbit sera, used as a model, are unrelated; changes in the titers and avidity of antibodies in the dynamics of immune response at different schemes of immunization have been mathematically described by means of regressive equations.

Animals↗

PubMed1988

Chemometrics: measurement reliability.

Applying the principles of chemometrics can lead to development of a powerful, simple, comprehensive system for characterizing measurement reliability of analytical processes. The system described here consists of a format for specifications, definitions, and decision rules for evaluating and comparing analytical processes. Two cases illustrate its advantages over the use of precision, accuracy, total error, and regression statistics for such evaluations.

Chemistry, Clinical↗

PubMed1988

A study of the intensity and frequency of crisis intervention for students enrolled in a school for the severely emotionally disturbed.

The present study explored the characteristics of students with a marked need for disciplinary crisis intervention (a modified time-out procedure). The study's sample consisted of 62 adolescents enrolled at a school serving the severely emotionally disturbed. Data on student background characteristics (IQ, academic achievement), behavioral adjustment, and sociometric ratings were gathered and related to intensity and frequency of crisis intervention. Data were subjected to correlational and multiple regression statistical procedures. One noteworthy finding is that students with a pronounced need for crisis intervention were rejected by their peers, yet indicated having positive perceptions of them. However, the central finding is that students with strong crisis intervention needs displayed a range of behaviors that can be characterized as a disturbance in conduct. Thus, this study supports the use of therapeutic interventions aimed at enhancing behavioral control for these students.

Adolescent↗

PubMed1986

Predictors of mortality in the immunocompromised patient with pulmonary infiltrates.

To determine predictors of mortality in immunocompromised patients with pulmonary infiltrates, we reviewed the records of all such patients admitted to two community teaching hospitals who underwent a lung biopsy over a ten-year period. We examined the consequences of advancing age, primary disease, fever, neutropenia, immunosuppressive corticosteroid therapy, previous lung radiation, roentgenographic pattern, result of lung biopsy, room air arterial oxygen pressure (Pao2), early mechanical ventilation, and the presence of a comorbid disease on eventual outcome. We identified 104 episodes in 99 patients. Sixty-seven (64%) survived and 37 died. By both discriminant analysis and logistic regression statistical methods, mechanical ventilation, the initial room air Pao2, and corticosteroid therapy were the dominant independent variables, in that order, to significantly predict mortality. No patient survived who simultaneously had a room air Pao2 less than or equal to 50 mm Hg, was on corticosteroids, and was mechanically ventilated. Eighty-three percent of survivors had either none or, at most, one of these three variables present. We conclude that hypoxia, immunosuppression by corticosteroids, and the necessity for mechanical ventilation within 72 hours of hospitalization indicate a poor prognosis in the immunocompromised patient with pulmonary infiltrates who has undergone a lung biopsy.

Adolescent↗

PubMed1987

Fascioliasis in cattle in Louisiana: development of a system to predict disease risk by climate, using the Thornthwaite water budget.

A system correlating climate with the annual risk of fascioliasis in cattle in central Louisiana was developed, using the Thornthwaite water budget and a 6-year data base that included records on herd prevalence rates, transmission to fluke-free sentinel calves, and snail population dynamics. The system developed was compared with modifications of the wet-day and Mt forecasting systems previously developed for use in the oceanic climate zone of western Europe. The wet-day system correlated poorly with transmission data, whereas the Mt and Thornthwaite water budget-derived systems correctly ranked 5 of the 6 years in terms of annual numbers of flukes transmitted to sentinel calves. Compared with the Mt system, the water budget-based system more closely correlated with transmission data, on the basis of statistical regression analysis. The water budget system was calculated by use of a microcomputer software program, and provided a means of measuring the effect of moisture stress and flooding in snail habitats that serve as foci of transmission of Fasciola hepatica to cattle on pastures.

Animals↗

PubMed1987

Sensitivities in older eyes with good acuity: cross-sectional norms.

We measured several indices of foveal visual function for a large group of people aged 60 and older. The data reported in this paper are from individuals who had good acuity in each eye and met a number of other criteria for good ocular health. For each index, we described the rate of cross-sectional change with age using linear regression statistics. We found age-related change for eyes having 20/20 or better acuity to exist for several different indices. Sensitivity mediated by the blue-sensitive cones decreased with age, as expected. However, the rate of decrease was faster for females than for males. At least part of the difference was associated with different rates of lenticular change. Absolute sensitivity at long wavelengths also decreased with age, but at the same rate for each sex. Rayleigh color matches changed with age in a manner consistent with underlying age-related decreases of effective foveal cone photopigment density. However, not all indices showed age-dependent changes. For instance, the time constant describing the rate of photopic dark adaptation did not appear to change with age.

Aging↗

PubMed1986

Model for estimation of clinically achievable plasma concentrations for investigational anticancer drugs in man.

A major problem related to in vitro testing of new investigational anticancer compounds is the lack of accurate pharmacokinetic data for the drugs in man. Based on the concept of a relationship between certain toxicologic endpoints in animal systems and maximally tolerated doses in man, we hypothesized that a comparable agreement might exist between these experimental animal toxicology data and clinically achievable peak plasma concentrations (PPCs). A retrospective analysis of the known data pairs of 28 commonly used cytotoxic compounds supports the existence of a reasonably good correlation between ip LD50 values (Pearson test) in nontumored mice and PPCs in man (r2 = 0.501; P less than 0.0001). Our data suggest that by use of the resultant statistical regression model a rational starting point can be selected for in vitro screening of entirely new agents for which human PPCs are not available. Additionally, application of this approach may also prove useful in relation to selecting in vitro doses for chemosensitivity assays intended for predictive correlation with clinical response in cancer patients.

Animals↗

PubMed1972

Document delivery capabilities of major biomedical libraries in 1968: results of a national survey employing standardized tests.

The standardized Document Delivery Tests (DDT's) developed earlier (Bulletin 56: 241-267, July 1968) were employed to assess the capability of ninety-two medical school libraries for meeting the document needs of biomedical researchers, and the capability of fifteen major resource libraries for filling I-L requests from biomedical libraries. The primary test data are summarized as statistics on the observed availability status of the 300 plus documents in the test samples, and as measures expressing capability as a function of the mean time that would be required for users to obtain test sample documents. A mathematical model is developed in which the virtual capability of a library, as seen by its users, equals the algebraic sum of the basic capability afforded by its holdings; the combined losses attributable to use of its collection, processing, relative inacessibility, and housekeeping problems; and the gain realized by coupling with other resources (I-L borrowing). For a particular library, or group of libraries, empirical values for each of these variables can be calculated easily from the capability measures and the status statistics. Regression equations are derived that provide useful predictions of basic capability from collection size. The most important result of this work is that cost-effectiveness analyses can now be used as practical decision aids in managing a basic library service. A program of periodic surveys and further development of DDT's is recommended as appropriate for the Medical Library Association.

Costs and Cost Analysis↗

PubMed1978

[Annual rhythms in frequency of electroencephalographic patterns (author's transl)].

A series of electroencephalographic features were measured for about 11,500 patients from a clinical population, over a period of five years (1972 to 1976) and were documented using a standarized procedure. It could be shown that for males a definite yearly rhythm was present for the relative frequencies of alpha-type, partial beta-type, and low voltage EEGs, as well as for continuous and grouped dysrhythmias, the amplitudes of which were in the main 20--30% of the average. For females on the other hand, apart from grouped dysrhythmias, no such yearly rhythms could be proven, at the most such with a periodicity of between 14 and 16 months. The data often display trends that are more distinct than the rhythmicity and as such these should be taken into consideration when deciding upon the model used for statistical regression.

Alpha Rhythm↗

PubMed1983

Evaluation of a radioimmunoassay for estradiol in unextracted serum.

We describe the performance of a commercial (Steranti/EIR) RIA reagent kit for measuring 17 beta-estradiol directly in serum. Day-to-day precision data for control sera were as follows: mean = 102.8 ng/L, CV = 6.8%, n = 20; mean = 231.1 ng/L, CV = 5.3%, n = 21; mean = 747.7 ng/L, CV = 9.4%, n = 21. Analytical recovery of added estradiol from seven different serum pools from men, to which three different concentrations of estradiol had been added, was (mean +/- SD): 98.6 +/- 7.0% at 107.5 ng/L added; 98.8 +/- 4.7% at 322.5 ng/L added; 108.2 +/- 4.8% at 645 ng/L added. Overall recovery of estradiol in these experiments (mean +/- SD for 21 determinations) averaged 101.9 +/- 7.0%. Assay of 32 serum specimens from women by both the direct (y) and an extraction method (x) gave the following linear regression statistics: y = 1.12x - 1.3, r = 0.998, Sy/x = 30.2 ng/L, mean y = 438.2 ng/L, mean x = 391.4 ng/L. Hemoglobin, bilirubin, and moderate lipemia do not interfere. Sensitivity of the direct assay was 2.6 ng/L. Compared with the extraction assay, the direct estradiol assay has advantages of speed and simplicity.

Estradiol↗

PubMed1984

The Ektachem clinical chemistry slide for simultaneous determination of unconjugated and sugar-conjugated bilirubin.

Using dual-wavelength spectrometry, we have refined the mordant-based bilirubin slide method (Clin Chem 28:2366-2372, 1982) to co-detect unconjugated bilirubin (Bu) and its sugar conjugates (Bc) in 10 microL of serum. The assay is based on three principles: (a) mono- and diconjugated bilirubins behave spectrally like one fraction (Bc) when bound to the mordant, (b) Bu and Bc are spectrally distinct, and (c) B delta (the bilirubin-albumin complex) is not measured in the film. With known bilirubin mixtures, results by the assay agree with those by nuclear magnetic resonance, by a Jendrassik-Gróf method for total bilirubin, and by a liquid-chromatographic procedure. With patients' sera, the slide correlates with a liquid-chromatography-augmented Jendrassik-Gróf method, according to the following typical regression statistics (in mumol/L): for Bu, slope = 0.992, r = 0.996, intercept = -0.376, Sy X x = 5.08; for Bc, slope = 0.970, r = 0.985, intercept = -0.735, Sy X x = 8.16. The method is precise (for Bu, CV = 5.2% at an average concentration of 16.4 mumol/L, and 4.1% at 66.7 mumol/L; for Bc, CV = 6.5% at 23.4 mumol/L, and 3.8% at 151.7 mumol/L for pools of patients' sera), is relatively interference free, and has potential for extension to further applications.

Adult↗

PubMed1982

Micellar improvement of the calmagite compleximetric measurement of magnesium in plasma.

Magnesium in plasma is determined by diluting a 50-microL sample with 5.0 mL of stable calmagite reagent containing the amphoteric detergent Empigen BB, and buffered with 2-amino-2-methyl-1-propanol at pH 11.5. The calcium response is masked with strontium-buffered [ethylene-bis(oxyethylenenitrilo)]tetraacetate (EGTA), while iron is masked with triethanolamine. The detergent causes an increased separation of the test and blank spectral absorbance bands. The test absorbance peaks, which may be measured immediately, are at 520 nm, while the blank peak shifts from 610 to 655 nm on addition of detergent. The blank absorbance at 520 nm is relatively decreased by the detergent. This allows the use of a more concentrated calmagite reagent, which in turn extends the linear relation of absorbance to magnesium concentration to 5 mmol/L in plasma. This method (y) has been compared with atomic absorption procedure (x) of McDonald and Watson (Clin, Chim. Acta 14: 233, 1966) and gives favorable regression statistics (y = 1.001X + 0.057 mmol/L).

Azo Compounds↗

PubMed1981

Mother-infant feeding interaction and weight gain in the first month of life.

This study tests the hypothesis that maternal and infant behaviors during a feed at one month of life co-varies with the infant's weight gain in the 30 days since birth. Thirty mothers-infant pairs were observed via videotape. Each of the tapes was analyzed, with a behavioral coding system adapted for this purpose. A stepwise regression statistical model showed that a statistically significant portion of the weight gain variance was explained by nutritionally functional and social communication behaviors in the mother and social communication behaviors in the infant. These data suggest that a lack of synchrony between the caretaker and the infant during feeding may imperil the infant's growth process.

Birth Weight↗

PubMed1981

The Seattle longitudinal prospective study on alcohol and pregnancy.

An unselected sample of 1529 women (predominantly white, married, and middle-class) were interviewed during pregnancy regarding their use of alcohol, nicotine, caffeine, drugs, and other variables. Subsets of offspring were examined to assess the relationship of self-reported maternal alcohol use to infant health and development. Multiple regression statistical tests were utilized to permit adjustment for other possibly confounding factors. The following are among those outcomes significantly related to increase maternal alcohol use after adjusting for smoking and other variables: smaller infant size (birth weight, length and head circumference); lower Apgar scores; poorer neonatal habituation; decreased sucking pressure; increased tremulousness and head-turns-to-left; decreased vigorous activity; and a higher frequency of minor dysmorphic characteristics combined with low birth weight and microcephaly. A drinking by smoking interaction was related to poorer newborn conditioning in two separate studies. Significantly lower mental and motor development and lower length and weight were found on follow-up of 468 infants at age 8 months. Follow-up studies continue.

Alcohol Drinking↗