Correlation between systolic blood pressure and physical development in adolescence

Although the close relation between blood pressure and physical development in adolescence has been established in cross-sectional and comparative cross-sectional studies, the entire trend of systolic blood pressure (SBP) during adolescence has not been elucidated in conjunction with physical development in a longitudinal study. Blood pressure (mmHg), body weight (kg), and body height (m) were measured annually for 418 subjects in Hiroshima and Nagasaki, Japan, from age 10 (1955 or 1956) through 18 years (1963 or 1964). The Gompertz growth model was used to determine the velocity of weight increase (VEL) during that age period. The relations between SBP from age 10 to 18 and VEL, weight, height, body mass index (BMI; weight/height2, kg/m2), and the age at which the measurements were made were investigated individually using random-coefficient growth-curve analysis. The SBP trend for the 10- to 18-year age period could be shown by the following prediction equations: for the 163 Hiroshima males, SBP = 82.38 + 0.89 VEL at age 1.15 years prior to the current examination (VEL (age - 1.15)) + 1.40 BMI; for the 57 Nagasaki males, SBP = 92.70 + 1.07 VEL (age - 1.15) + 0.79 BMI; for the 148 Hiroshima females, SBP = 104.88 + 1.63 VEL (age - 1.15) + 0.05 BMI; for the 50 Nagasaki females, SBP = 113.62 + 1.67 VEL (age - 1.15) - 0.59 BMI. VEL 1.15 years prior to the current examination was significantly and positively related to SBP in each city by sex group (p < 0.01), and current BMI was significantly related to SBP for males in Hiroshima (p < 0.01) and nearly so in Nagasaki (p = 0.06), but not for females in either city (p = 0.84 and 0.13, respectively). Because the plot of VEL was a convex curve, SBP peaked approximately 1-2 years after the peak in VEL and then decreased in both sexes. The entire SBP trend during adolescence can be expressed as an equation of VEL and BMI in males and of VEL in females. SBP does not increase linearly with age.

Lipophilic antifolates as agents against opportunistic infections. 1. Agents superior to trimetrexate and piritrexim against Toxoplasma gondii and Pneumocystis carinii in in vitro evaluations

2,4-Diaminopteridines (21 compounds) and 2,4-diamino-5-methyl-5-deazapteridines (34 compounds) along with three 2,4-diamino-5-unsubstituted-5-deazapteridines and four 2,4-diaminoquinazolines, each with an aryl groups attached to the 6-position of the heterocyclic moiety through a two-atom bridge (either CH2NH, CH2N(CH3),CH2S, or CH2CH2), were synthesized and evaluated as inhibitors of the growth of Toxoplasma gondii in culture and as inhibitors of dihydrofolate reductase enzymes from T. gondii, Pneumocystis carinii, and rat liver. Exceptionally high levels of combined potency and selectivity as growth inhibitors of T. gondii and as inhibitors of the microbial enzymes relative to the mammalian enzyme were found among the 5-methyl-5-deazapteridines but not for the other heterocyclic types. Thirty of the 34 5-methyl-5-deaza compounds gave growth inhibition IC50 values lower than that of pyrimethamine (0.4 microM) with 14 compounds below 0.1 microM, values that compare favorably with those for piritrexim and trimetrexate (both near 0.02 microM). As inhibitors of T gondii DHFR, all but three of the 34 5-methyl-5-deaza compounds gave IC50 values in the order of magnitude with those of piritrexim (0.017 microM) and trimetrexate (0.010 microM), and 17 compounds of this group gave IC50 values versus P. carinii DHFR similarly comparable with those of piritrexim (0.031 microM) and trimetrexate (0.042 microM). Thirteen of these congeners gave both T. gondii growth inhibition and DHFR inhibition IC50 values of 0.10 microM or less, thus indicating facile penetration of the cell membrane. Eleven of these inhibitors of both T. gondii growth and DHFR have selectivity ratios (IC50 rat liver divided by IC50 T. gondii) of 5 or greater for the parasite DHFR. The highest selectivity ratio of nearly 100 belongs to the 5-methyl-5-deaza compound whose 6-substituent is CH2CH2C6H3(OCH3)2-2,5. This compound is over 10(3)-fold more selective for T. gondii DHFR than bridge homologue piritrexim (selectivity ratio 0.088), a compound now in clinical trials. The candidate with CH2NHC6H3(CH3)2-2,5 in the 6-position gave the highest P. carinii DHFR selectivity ratio of 4.0, which is about 60-fold more selective than trimetrexate (0.071) and 80-fold more selective than piritrexim (0.048) toward this enzyme. The 10 best compounds with respect to potency and selectivity includes six compounds bearing 2,5-disubstituted phenyl groups in the side chain (with little, if any, difference in effects of methyl, methoxy, or ethoxy), two side chains bearing 1-naphthyl groups, and two with 5,6,7,8-tetrahydro-1-naphthyl groups. Bridge groups represented in the 10 choice compounds are CH2NH, CH2N(CH3), CH2CH2, and CH2S. The high levels of both potency and selectivity among these agents suggest that in vivo studies now underway may lead to agents that could replace trimetrexate and piritrexim in treatment of toxoplasmosis and P. carinii pneumonia.

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.

An index for early assessment of neonatal survival in low birthweight infants

Since its development in the 1950s, the Apgar index has come into widespread use as a tool to evaluate neonatal condition, with predictive implications for mortality and morbidity. However, Apgar scores were validated in predominantly term infants and have questionable prognostic value for low birthweight infants. The purpose of this study was to develop a survival index applicable to premature infants. Thirty-six perinatal variables were evaluated initially, based on data from 441 neonates weighing 500 to 1800 g. A multifactorial index of nine variables was derived, each independently related to mortality. Sensitivity of the index was 95%, specificity was 68%, positive predictive value was 90%, and negative predictive value was 81%. This index provides the most accurate tool yet reported in the literature for predicting concurrent survival of premature infants. The tool is recommended for use as an index of neonatal condition for low birthweight infants. Its additional use, as a predictor of the likelihood of survival would require time and place specific validation.

Height reduction among prenatally exposed atomic-bomb survivors: a longitudinal study of growth

Using a random coefficient regression model, sex-specific longitudinal analyses of height were made on 801 (392 male and 409 female) atomic-bomb survivors exposed in utero to detect dose effects on standing height. The data set resulted from repeated measurements of standing height of adolescents (age 10-18 y). The dose effect, if any, was assumed to be linear. Gestational ages at the time of radiation exposure were divided into trimesters. Since an earlier longitudinal data analysis has demonstrated radiation effects on height, the emphasis in this paper is on the interaction between dose and gestational age at exposure and radiation effects on the age of occurrence of the adolescent growth spurt. For males, a cubic polynomial growth-curve model applied to the data was affected significantly by radiation. The dose by trimester interaction effect was not significant. The onset of adolescent growth spurt was estimated at about 13 y at 0 Gy. There was no effect of radiation on the adolescent growth spurt. For females, a quadratic polynomial growth-curve model was fitted to the data. The dose effect was significant, while the dose by trimester interaction was again not significant.

Anti-Human T-lymphotropic virus type-I antibodies in atomic-bomb survivors

Adult T-cell leukemia (ATL), induced by human T- lymphotropic virus type-I (HTLV-I), is endemic in Nagasaki, Japan. To investigate the effects of atomic-bomb radiation on development of this specific type of leukemia, 6182 individuals in the Radiation Effects Research Foundation (RERF) Adult Health Study sample in Hiroshima and Nagasaki were examined for positive rate of HTLV-I antibody. Several lymphocyte parameters were also studied for 70 antibody- positive subjects in Nagasaki. The HTLV-I antibody-positive rate was higher in Nagasaki (6.36%) than in Hiroshima (0.79%) and significantly increased with increasing age, but no association was observed with radiation dose. Whether relationship existed between antibody titer levels and radiation dose among antibody-positive subjects was not The frequency of abnormal lymphocytes tended to be higher in antibody-positive subjects than in antibody-negative subjects, and higher in females than in males regardless of radiation dose. The lymphocyte count was lower in antibody-positive subjects than in antibody-negative subjects and lower in female than in male subjects. No evidence was found to suggest that atomic-bomb radiation plays an important role in HTLV-I infection.

Cytoplasmic male sterility in sunflower: origin, inheritance, and frequency in natural populations

Cytoplasmic male sterility (CMS) in commercial sunflower hybrids is thought to be derived from a related wild species, Helianthus petiolaris, yet CMS lines are known to carry the chloroplast DNA genotype of H. annuus. To clarify the origin of sunflower CMS, we developed a polymerase chain reaction-based strategy for detecting CMS in sunflower and surveyed more than 1,200 plants representing 55 accessions of H. annuus and 26 accessions of H. petiolaris. We also tested 160 progeny from three crosses for strict maternal inheritance of organelle DNAs to determine if the apparent discrepancy in the species donor of the mitochondrial DNA and chloroplast DNA genotypes in CMS lines might result from low-frequency maternal or biparental inheritance of either organelle. No CMS cytotypes were observed in natural populations of either H. annuus or H. petiolaris, and strict maternal inheritance of organelle DNA was observed. These data provide little insight, therefore, into the origin and population genetics of CMS in natural populations of sunflower, except that the evidence for strict maternal inheritance of organelles in sunflower makes it unlikely that the mtDNA and cpDNA genotypes in CMS lines were derived from different species. Nonetheless, the primers developed for assaying organelle DNA variation in sunflower may be useful tools for plant breeding programs, cytotype identification, and systematic and evolutionary studies in the domesticated sunflower and its relatives.

Autoantibodies and immunoglobulins among atomic bomb survivors

The purpose of this study was to determine if exposure to atomic bomb radiation affects immune responsiveness, such as the occurrence of autoantibodies and levels of immunoglobulins. Rheumatoid factor, antinuclear antibody, antithyroglobulin antibody, anti-thyroid-microsomal antibody and immunoglobulin levels (IgG, IgM, IgA and IgE) were measured among 2,061 individuals exposed to atomic bomb radiation in Hiroshima and Nagasaki whose estimated doses ranged from 0 to 5.6 Gy. The prevalence and titers of rheumatoid factor were found to be increased in the individuals exposed to higher radiation doses. The IgA level in females and the IgM level in both sexes increased as radiation dose increased, although the effects of radiation exposure were not large. No effect of radiation was found on the prevalence of antinuclear antibody, antithyroglobulin antibody and anti-thyroid-microsomal antibody or on the levels of IgG and IgE.

The pathologist's appraisal of neck dissections

A critical assessment is presented on the description and interpretation of histopathological findings in neck dissections undertaken in patients with squamous carcinomas originating in the head and neck. The topics covered include the localization and measurement of nodal metastases, variant histopathological appearances, micrometastases and extranodal spread.

Application of generalized estimating equations to a study of in vitro radiation sensitivity

We describe an application of the generalized estimating equation (GEE) method (Liang and Zeger, 1986, Biometrika 73, 13-22) for regression analysis of correlated Poisson data from a split-plot design with a small number of experimental units. As an alternative to the use of an arbitrarily chosen working correlation matrix, we demonstrate the use of GEE with a reasonable model for the true covariance structure among repeated observations within individuals. We show that, under such a split-plot design with large clusters, the asymptotic relative efficiency of GEE with simple (independence or exchangeable) working correlation matrices is rather low. We conclude by summarizing issues and needs for further work concerning efficiency of the GEE parameter estimates in practice.

Different dimerization activities of alpha and beta thyroid hormone receptor isoforms

Thyroid hormone receptors (TR) are ligand-dependent transcription factors that are encoded as multiple isoforms on two genes. To date, no functional differences have been shown between the TR isoforms; however, the maintenance of alpha and beta genes during vertebrate evolution argues that functional differences do exist. We have localized a TR-binding site in the rabbit beta-myosin heavy chain gene. This site and TR-binding sites in the chicken lysozyme and rat alpha-glycoprotein hormone genes were used to compare the DNA-binding activities of TR alpha and TR beta and the influence of auxiliary proteins (TRAP). TR alpha formed alpha/alpha homodimers poorly, whereas TR beta formed beta/beta homodimers preferentially. This difference was not due to either a lower amount of TR alpha synthesized in the reticulocyte lysate or to an inability of the expressed TR alpha to form dimers, since both TR alpha and TR beta readily formed heterodimers with TRAP on these TR-binding sites. Additionally, a TR alpha fragment containing the dimerization domains (TR alpha C291) blocks TR beta/TRAP complexes but not TR alpha/TRAP complexes. This indicates that TR beta/TR alpha dimers form more readily than TR alpha/TR alpha dimers. We conclude that on the binding sites examined, TR beta has a greater tendency to form homodimers than TR alpha, whereas both isoforms form heterodimers similarly. The different homodimerization potentials of TR alpha and TR beta may underlie functional differences that affect thyroid hormone responses.

Pathology of squamous carcinomas of the head and neck

Recent publications dealing with the pathology of squamous carcinomas of the head and neck have been critically reviewed with particular reference to potential prognostic factors and improved methods for identifying nodal metastases. The topics covered include cytophotometry and proliferative patterns, molecular biology (EGFR and p53 genes), cell adhesion molecules (E cadherin), and combined radiologic and pathologic approaches to detect small volume metastases in cervical lymph nodes.

Monoclonal gammopathy in atomic bomb survivors

An analysis of monoclonal gammopathy in relation to radiation exposure was conducted on atomic bomb survivors examined between October 1979 and September 1981 and between June 1985 and May 1987. There was no overall increase in the relative risk of monoclonal gammopathy and only a suggestive increase in benign monoclonal gammopathy in the second survey which did not achieve statistical significance (P = 0.17). Thirty-one cases were detected among 8796 individuals studied in the first survey, whereas 68 cases were found among 7350 people in the second survey. Among the 31 cases found in the first survey, 9 individuals (29%) died before the second survey: 4 of cancer, 4 of vascular disease, and 1 of infection. Among the 8 individuals with benign monoclonal gammopathy examined in both surveys, 4 developed suppression of residual immunoglobulin(s), suggesting the progression of monoclonal gammopathy. The overall relative risks of monoclonal gammopathy in atomic bomb survivors in the two surveys were not significantly increased with increasing radiation dose. Only benign monoclonal gammopathy in 1985-1987 showed a suggestive increase with radiation exposure. The relative risk of benign monoclonal gammopathy in 1985-1987 was 2.64 in the group exposed to 0.01-0.49 Gy and 2.14 in the > or = 0.50-Gy group (95% confidence intervals = 0.90-8.82 and 0.69-7.31, respectively).

Histological re-evaluation of 101 intraoral salivary gland tumors by an EORTC-study group

Tumors of the salivary glands constitute a heterogeneous group of lesions of great morphologic variation and for this reason present many difficulties in histologic classification. The histologic slides of 101 consecutive intraoral salivary gland tumors of the Department of Oral Pathology of the Free University in Amsterdam were reviewed, retrospectively, by an EORTC-study group on salivary gland tumors. Complete concurrence of diagnosis was reached in 54 cases. In 33 cases there were minor disagreements, mostly related to subclassification. Major disagreements, relating to benign versus malignant, occurred in eight cases (7.9 per cent).

Mixed-effects nonlinear regression for unbalanced repeated measures

Repeated measures data, such as clinical pharmacokinetic data, growth data, and dose-response data, are often inherently nonlinear with respect to a given response function and are frequently incomplete and/or unbalanced. Nonlinear random-effects models together with a variety of estimation procedures have been proposed for the analysis of such data. This paper is concerned with a straightforward procedure for estimating and comparing the parameters of a generalized mixed-effects nonlinear regression model. The asymptotic properties of the proposed estimators are given and large-sample tests of hypothesis provided. The results are applied to in vitro data on the water transport kinetics of hemodialyzers used in the treatment of patients with chronic renal failure.

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.

Triiodothyronine (T3) decreases binding to DNA by T3-receptor homodimers but not receptor-auxiliary protein heterodimers

Thyroid hormone receptors (TRs) are ligand-dependent transcription factors that bind to thyroid hormone response elements (TREs) to mediate positive and negative regulation of transcription of thyroid hormone-responsive genes. TR binding to TREs can be enhanced by interaction with a nuclear protein, triiodothyronine (T3) receptor auxiliary protein (TRAP). There are two major isoforms of thyroid hormone receptors, TR alpha-1 and TR beta-1, which are encoded on two separate genes. We studied the binding of TR alpha-1 and TR beta-1 to several TREs: the chick lysozyme TRE (F2), which is positively regulated by T3; rabbit beta-myosin heavy chain TRE, which is negatively regulated by T3; and an idealized inverted palindrome, TRElap. We demonstrate the formation of homodimers, TR alpha/TR beta dimers, and TR/TRAP heterodimers when receptor is bound to these DNA sequences. Surprisingly, we found that T3 decreased TR alpha-1 and TR beta-1 homodimer binding in a dose-dependent manner to these TREs as well as TR alpha/TR beta dimer binding to F2. In contrast, T3 did not affect TR/TRAP heterodimer binding to TREs suggesting that this heterodimer may be the stable complex occupying TREs in the presence of ligand.

Peripheral nerve sheath differentiation in malignant soft tissue tumours: an ultrastructural and immunohistochemical study

Thirteen soft tissue sarcomas with ultrastructural evidence of nerve sheath differentiation were investigated by immunohistochemistry. Three arose in a major nerve or nerve trunk and four patients had von Recklinghausen's neurofibromatosis. Ultrastructurally, 10 cases showed variable differentiation towards Schwann cells, two resembled perineurial cells and one tumour had features suggestive of both cell types. Immunostaining for S-100 protein was positive in eight Schwann cell tumours, negative in the other two Schwann cell tumours and negative in those with perineurial-like cells. No cases demonstrated epithelial membrane antigen, so that the existence of perineurial cells in malignant nerve sheath tumours remains immunohistochemically unsubstantiated; it may be that the perineurial-like cells are merely incompletely differentiated Schwann cells, with nerve sheath differentiation manifesting a continuous spectrum. Leu 7 was detected in four Schwann cell tumours, three of which were ultrastructurally well differentiated. Cytokeratin and desmin were demonstrated only in an undifferentiated pleomorphic area of one Schwann cell tumour. Electronmicroscopy can aid diagnosis by revealing nerve sheath differentiation in malignant soft tissue tumours without demonstrable S-100 protein.

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.

Measurement, analysis, and modelling of the caloric response. 1. A descriptive mathematical model of the caloric response over time

A mathematical model for describing the caloric response over time offers many important advantages over the commercially-available qualitatively-fitted curves that are now used by the clinician for evaluating caloric results. In this report advances in the development of a nonlinear least-squares mathematical model are discussed and the roles and derivations of fitting parameters and curve-derived indices are outlined. This model provides a rigorous and objective description of the caloric response in its entirety with four continuous parameters. These fitting parameters make it possible to 1) describe individual caloric responses precisely and uniquely, 2) compare pairs of individual caloric responses or groups of caloric responses statistically, 3) extract information not previously available, 4) quantify variability within the caloric response, and 5) model physical properties of the caloric stimulus and physiological variables affecting the caloric response. Results from this model are compared with the results from our earlier models and with traditional multiparameter caloric results.

Expression of members of the myf gene family in human rhabdomyosarcomas

Northern analysis of tumour RNA has been used to examine the expression of members of the myf family of muscle determining genes (myf3, myf4, myf5 and myf6) in a series of 20 rhabdomyosarcomas. A 2.0 kb myf3 transcript was observed in 85% of tumours, a 1.8 kb myf4 transcript was detected in 70% of tumours and a 1.7 kb myf5 transcript was observed in 55% of tumours. Transcription of myf6 occurred in 28% of tumours, but there were several transcript sizes (1.2, 1.5, 2.0 and 3.5 kb) and in some individual tumours two or more transcripts were observed. Only two rhabdomyosarcomas, one classified as embryonal and one as pleomorphic, failed to exhibit transcription of members of the myf gene family. We were unable to detect transcription of myf genes in neuroblastomas, Wilms' tumours, hepatoblastomas, paediatric non-Hodgkin's lymphoma and leiomyosarcomas. When considered together these observations suggest that expression of myf genes could provide an extremely useful marker in the diagnosis of rhabdomyosarcoma.