Housing characteristics and indoor air quality in households of Alaska Native children with chronic lung conditions.

Alaska Native children experience high rates of respiratory infections and conditions. Household crowding, indoor smoke, lack of piped water, and poverty have been associated with respiratory infections. We describe the baseline household characteristics of children with severe or chronic lung disease participating in a 2012-2015 indoor air study. We monitored indoor PM2.5, CO2 , relative humidity %, temperature, and VOCs and interviewed caregivers about children's respiratory symptoms. We evaluated the association between reported children's respiratory symptoms and indoor air quality indicators using multiple logistic regression analysis. Compared with general US households, study households were more likely overcrowded 73% (62%-82%) vs 3.2% (3.1%-3.3%); had higher woodstove use as primary heat source 16% (9%-25%) vs 2.1% (2.0%-2.2%); and higher proportion of children in a household with a smoker 49% (38%-60%) vs 26.2% (25.5%-26.8%). Median PM2.5 was 33 µg/m3 . Median CO2 was 1401 ppm. VOCs were detectable in all homes. VOCs, smoker, primary wood heat, and PM2.5>25 µg/m3 were associated with higher risk for cough between colds; VOCs were associated with higher risk for wheeze between colds and asthma diagnosis. High indoor air pollutant levels were associated with respiratory symptoms in household children, likely related to overcrowding, poor ventilation, woodstove use, and tobacco smoke.

A versatile retarding potential analyzer for nano-satellite platforms.

The design of the first retarding potential analyzer (RPA) built specifically for use on resource-limited cubesat platforms is described. The size, mass, and power consumption are consistent with the limitations of a nano-satellite, but the performance specifications are commensurate with those of RPAs flown on much larger platforms. The instrument is capable of measuring the ion density, temperature, and the ram component of the ion velocity in the spacecraft reference frame, while also providing estimates of the ion composition. The mechanical and electrical designs are described, as are the operating modes, command and data structure, and timing scheme. Test data obtained using an ion source inside a laboratory vacuum chamber are presented to validate the performance of the new design.

Metabolic characterization of distinct neuroanatomical regions in rats by magic angle spinning 1H nuclear magnetic resonance spectroscopy.

High-resolution magic angle spinning (HRMAS) (1)H NMR spectroscopy has been applied to the biochemical characterization of specific brain regions in rats in order to establish baseline levels of tissue metabolite profiles with which to compare models of neuropathology or toxic lesion. Cores of tissue (20 mg) from the brain stem, cerebellum, frontal cortex, and hippocampus were obtained from histologically defined coronal slices of brain from 18 male Sprague-Dawley rats. HRMAS (1)H NMR spectra were acquired for each of the regions sampled and the degree of intersample variability, as assessed by principal components analysis and discriminant analysis by projection to latent structure was found to be low. Clear region-specific differences in the biochemical profiles were observed using both comparison of metabolite ratios and/or pattern recognition methods. Relatively low concentrations of GABA in the cerebellum, high concentrations of taurine and N-acetylaspartate in the cortex, and high levels of choline, glycerophosphocholine, and phosphocholine in the hippocampus predominantly influenced the classification of the different brain regions. Additionally, N-acetylaspartylglutamate was detected in the brain stem, but was largely absent from the other regions examined. Such analyses provide a baseline reference for further HRMAS NMR spectroscopic studies to monitor disease and pharmacological insults in specific regions of the brain.

Spontaneous and induced alterations in the cardiac membranous ventricular septum of fetal, weanling, and adult rats.

Alterations of the cardiac membranous ventricular septum were studied using macrodissection, scanning electron and light microscopy of fetal, weanling, and adult Sprague-Dawley rats. Membranous ventricular septal defects (VSDs) were observed in 2.0% of fetuses on day 21 postcoitus (pc) but not in weanling or adult rats. The most common observation was a nonpatent depression in the membranous septum with an incidence of 38.1, 10.5, 4.3% for fetuses on days 17, 19, or 21 pc, respectively, 11.8% for weanlings, and 9.1% for adults. VSDs were characterized by a split in the endocardial cushion cells in the interventricular component of the membranous septum. Nonpatent depressions were characterized by a split in the endocardial cushion cells in the atrioventricular component of the septum, and they persisted postnatally as a blind-ended diverticulum directed above the tricuspid valve. The cardiovascular teratogens, trimethadione and trypan blue, produced in fetuses nonpatent depressions and VSDs morphologically similar to untreated fetuses. Maternal diet restriction (25% of controls) lowered fetal (day 21 pc) body weight by 47% but did not affect the incidence of ventricular septal alterations, suggesting that intrauterine growth retardation is not necessarily associated with alterations in the development of the ventricular septum. We conclude that neither VSDs nor nonpatent depressions in Sprague-Dawley rats affect postnatal survival and that VSDs close spontaneously during neonatal life.

Health promotion needs of students in a college environment.

A significant amount of the mortality and morbidity experienced by Americans of all ages today is preventable. Research directed toward the identification of health promotion needs of traditional students in college environments may contribute to the development and implementation of programs and activities that assist students to adopt healthy lifestyle behaviors throughout their life spans. The purpose of this descriptive survey study was to identify the health promotion needs of traditional students in a college environment. More specifically, the research question was: What are the health promotion needs of traditional students in a college environment? Subjects were male and female students, 18-21 years of age, and enrolled in a full-time (minimum of 12 hours) program of study at one of two college campuses in a metropolitan southern city. One of these was a 2-year state-affiliated community college and the other was a private 4-year coeducation university. A randomized sample of 148 subjects was computed. Results of this study emphasize the distinctive individual and group health promotion needs of traditional students in a college environment. Identification of the health promotion needs of this population will enable health care providers to develop interventions to assist students in developing healthy lifestyle behaviors.

Morphology and incidence of hepatic foci of cellular alteration in Sprague-Dawley rats.

Morphology and incidence of altered hepatocellular foci (AHF) were evaluated in standard H&E-stained liver sections from 3 groups of control Sprague-Dawley (SD) rats (initially 70/sex/group) used in 2 2-yr carcinogenicity studies. All AHF observed could be classified as basophilic, eosinophilic, clear, vacuolated, or mixed types using criteria applied previously to the Fischer-344 (F-344) rat. Some eosinophilic foci were large and posed a diagnostic challenge in differentiation from hepatocellular adenoma. Rats were arbitrarily divided into 3 classes by age at death: 14-17, 18-23, and 24-26 mo. As reported for F-344 rats, the incidence of SD rats with AHF increased with age, and males with eosinophilic foci predominated over males with basophilic foci whereas the opposite held true for females. Mean incidence of rats with AHF at 18-23 mo was 28 and 38% for males and females, respectively, and at 24-26 months was 68 and 71%, respectively. These data indicate a strikingly lower incidence of spontaneous AHF in SD rats than that reported for F-344 rats.

The application of toxicokinetic data to dosage selection in toxicology studies.

Appropriate dosage selection is a key element in the design of toxicology studies and, hence, is the first step in the process of evaluating the safety of a new chemical or pharmaceutical agent. This demands careful consideration of exposure to the drug or chemical under investigation in relation to the pharmacological or toxicological effects it evokes in an experimental animal. Toxicokinetic data provide this perspective, but they should not be considered exclusively of other data which reflect the specific activity, potency, or metabolism of the drug or chemical in each individual test species. It is equally inappropriate to base dosage selection in toxicology studies exclusively on functional or morphological endpoints that cause effects outside the range which can be accommodated by homeostatic mechanisms and repair processes. Finally, extrapolation of toxicokinetic data across species lines can lead to serious miscalculations with respect to both dosage selection and the process of risk assessment. In each case, decisions should be based on the integration of toxicokinetic data with other measures and endpoints of biological and toxicological effect.

Development of tissue damage, inflammation and resolution following stroke: an immunohistochemical and quantitative planimetric study.

Development and resolution of the lesion produced by occlusion of the middle cerebral artery (MCAO) was studied through quantitative planimetry and histologic/immunohistochemical techniques. MCAO, performed in spontaneously hypertensive rats (SHR), initially (1-3 days) produced large, consistent cerebral cortical infarctions and an increase in ipsilateral hemispheric size (i.e., swelling) quantitated by planimetry on 2,3,5-triphenyltetrazolium chloride (TTC)-stained gross tissue sections. These initial changes correlated well with changes identified from 2 h to 3 days using hematoxylin and eosin stained histologic tissue sections and immunohistochemical techniques including: the progressive development of a cortical area of pan necrosis, infiltration of neutrophils into infarcted tissues, and activation of astroglia. During the initial 2 days following MCAO, glial fibrillary acidic protein immunoreactive cells increased in number and became larger and more intensely fluorescent medial to the cortical infarct. At 5 to 15 days, both the infarct and the ipsilateral hemisphere decreased in size. These changes correlated with the presence of abundant macrophages, and cavitation of the lesion along its medial border. Also during this period, a loose connective tissue matrix formed along the superficial aspect of the infarct. This connective tissue contained fibroblasts, extracellular matrix immunoreactive for laminin and collagen, capillary buds indicating neovascularization, and abundant macrophages. By the final timepoint (30 days), necrotic tissue could no longer be detected in either gross or histologic tissue sections, the inflammatory infiltrate had resolved, and the connective tissue was removed.(ABSTRACT TRUNCATED AT 250 WORDS)

Information systems for evaluating the quality of prescribing.

OBJECTIVE: An important purpose of drug usage evaluation (DUE) is to provide feedback to physicians on population-based prescribing patterns and problems. This article has four objectives: (1) to outline prescribing information requirements for a computerized information system in terms of the variables needed for DUE, (2) to describe existing computerized information systems that collect and organize prescribing data, (3) to assess existing systems in terms of their capacity to provide the requirements outlined in our first objective, and (4) to suggest design changes to existing systems that would improve the DUE process. ANALYSIS: There are several existing DUE information systems that have some capacity to evaluate the quality of prescribing in specific populations (e.g., veterans, public and private insured groups, hospital service areas). Shortcomings of most DUE information systems include patient identification problems, defects in database design, and lack of software to identify prescribing problems and perform statistical analysis. CONCLUSIONS: DUE information systems could be used and upgraded to enable physicians to develop more rational prescribing rules from population data that would improve the quality of prescribing.

Keller arthroplasty: is distraction a useful technique? A retrospective study.

A retrospective study comparing advantages of single or crossed intramedullary Kirschner wire fixation versus straight Keller arthroplasty is reported. The results suggest that the use of distractors weakly correlates with increase in both range of motion and overall patient satisfaction. It appears this correlation is related to temporary increase in joint space, which accordingly leads to increased fibrosis in the early postoperative stages, allowing for a better joint space and functional result.

Central-peripheral delayed neuropathy caused by diisopropyl phosphorofluoridate (DFP): segregation of peripheral nerve and spinal cord effects using biochemical, clinical, and morphological criteria.

Systemic injection of diisopropyl phosphorofluoridate (DFP; 1 mg/kg, sc) causes delayed neuropathy in hens. This effect is associated with a high level of organophosphorylation of neuropathy target esterase (NTE) followed by an intramolecular rearrangement called "aging." Phenylmethanesulfonyl fluoride (PMSF) also attacks the active center of NTE but "aging" cannot occur. This compound does not cause neuropathy and protects against a subsequent challenge systemic dose of DFP. Intraarterial injection of DFP (0.185 mg/kg) into only one leg of hens caused a high NTE inhibition (greater than 80%) in the sciatic nerve of the injected leg, but not in other parts of the nervous system (37% average). A unilateral neuropathy with typical histopathological lesions developed in the injected leg. PMSF (0.55 mg/kg) injected into each sciatic artery caused 47% inhibition of sciatic nerve NTE but only 17-22% inhibition of NTE elsewhere; it did not produce clinical or histopathological lesions. When these hens were challenged with DFP (1 mg/kg, sc), high inhibition of residual-free NTE (greater than 85%) occurred throughout the nervous system and clinical signs of a syndrome different from the classical delayed neuropathy developed: this spinal cord type of ataxia was associated with histopathological lesions in the spinal cord but not in peripheral nerve. PMSF (1 mg/kg) injected into only one sciatic artery caused selective protective inhibition of sciatic nerve NTE of that leg. After systemic challenge by DFP, clinical effects expressed were a combination of spinal cord ataxia plus unilateral peripheral neuropathy. The challenge dose of DFP (1 mg/kg, sc) was insufficient to produce clear histopathological lesions in unprotected peripheral nerves although spinal lesions were found in these hens. Thus clinical evaluation of the peripheral nervous system by means of walking tests and a simple test of "leg retraction" reflexes was more sensitive and specific in diagnosis of peripheral neuropathy than was the histopathology.

Maturation of vaginal and cervical epithelium in women exposed in utero to diethylstilbestrol (DESAD Project).

A total of 452 women with documented exposure in utero to diethylstilbestrol (DES) with epithelial findings present at the time of their initial examination have been evaluated prospectively to determine whether these findings changed over a period of 3 years. The examinations were all performed according to a strict protocol. Findings present at the time of the third annual examination were verified at a fourth examination. A verified decrease in the extent of epithelial findings occurred in 29.2% of these women and a verified increase in 6.6%; 53.1% had no change in the extent of epithelial findings, and 11.1% had a change that could not be verified at the time of the fourth visit. Analysis of many variables failed to identify a strong association between any variable and a decrease in the extent of the findings. It appears that the most important factor in the occurrence of changes in DES-associated findings is the passage of time.

A model of chronic spinal cord compression in the cat.

An experimental method of producing chronic compression of the cat spinal cord is described. A ligature placed around the lumbar spinal cord of 3-month-old kittens restricts the growth of the spinal cord to produce compression with a slow onset and an insidious progression. The methods of following the clinical progress of affected animals and of sampling the spinal cord after perfusion fixation are presented. The sampling method used allowed analysis of the three dimensional distribution of the pathological changes caused by the compression. These changes were not symmetrically distributed: the spinal cord caudal to the ligature became swollen and extensive partial demyelination occurred under the ligature and caudal to it, in the swollen region of the cord, whereas cranial to the ligature there was only minimal damage. It is concluded that the method produces a useful model of chronic compression of the spinal cord, which will be of value in studying partial demyelination.

Metachromatic leukodystrophy caused by a partial cerebroside sulfatase.

A patient with neuropathy and myopathy since infancy but whose neuropathy had been stable for a number of years showed a profound deficiency of arylsulfatase A in leukocytes and urine. Urine contained material that stained metachromatically and cochromatographed with cerebroside sulfate. In contrast, cultured fibroblasts contained about 10-20% of normal arylsulfatase A with properties identical to properties of normal fibroblast enzyme, except that it showed no cerebroside sulfatase activity. Growing fibroblasts in the cerebroside sulfate loading test had an attenuated rate of sulfatide hydrolysis. A re-examination of the cerebroside sulfatase reaction revealed that while only limited hydrolysis occurred with low concentrations of taurodeoxycholate or cholate (type I activation), significant hydrolysis of the natural substrate did take place with high concentrations of cholate (type II activation). This suggests that there is a partial cerebroside sulfatase defect in this atypical form of metachromatic leukodystrophy.

Toxocariasis in an institution for the mentally retarded.

A seroepidemiologic investigation was conducted in order to determine the cause of an apparent increase in rates of eosinophilia among 1400 institutionalized children during 1976-1977. The annual serologic survey during this period revealed 283 (20%) individuals with eosinophilia that exceeded 600 cells/cu mm of blood. During a five-month period in 1977, five patients who were hospitalized in adjacent wards developed acute pneumonia with eosinophilia. Because laboratory tests of sputum, bone marrow, and stool failed to identify the etiologic agent, it was thought that these pneumonia cases might be related to the increased rates of eosinophilia. Analyses of random samples of sera from patients with eosinophilia revealed seroprevalence rates of 12% for Ascaris, 20% for Toxocara canis, 24% for Strongyloides stercoralis, and 32% with increased antibody to Entamoeba histolytica. Further investigation showed a statistically significant positive association between occurrence of eosinophilia and pica behavior, and eosinophilia and contact with dogs. Although the serologic survey showed patients to have had previous exposure to a variety of parasites, we hypothesize that a principal cause of eosinophilia among institutionalized children may be Toxocara infestation, due to their frequent pica behavior and, in this case, contact with resident animals. We recommend that children in similar facilities have limited contact with pet dogs, and only after frequent and vigorous examination of the animals for infectious parasites.