Detection of vitamin A deficiency in Brazilian preschool children using the serum 30-day dose-response test.

BACKGROUND: Vitamin A deficiency (VAD) is endemic in Brazil and health professionals have difficulty in recognizing its subclinical form. In addition, serum retinol concentrations do not always represent vitamin A status in the organism. OBJECTIVE: To identify VAD in preschool children by the serum 30-day dose-response test (+S30DR) and to examine its potential as a tool for the assessment of vitamin A status in the community. DESIGN: A prospective transverse study in which blood samples were obtained from 188 preschool children for the determination of serum retinol concentrations and the children were submitted to ocular inspection and anthropometric measurements. Information about the presence of diarrhea and/or fever during the 15 days preceding the study was also obtained. The children received an oral dose of 200,000 IU vitamin A immediately after the first blood collection. A second blood sample was obtained 30-45 days after supplementation in order to determine the +S30DR. RESULTS: In all, 74.5% (140/188; 95% confidence interval: 68.3-80.7%) of the children presented +S30DR values indicative of low hepatic reserves. The mean serum retinol concentration was significantly lower before supplementation (0.92 and 1.65 micromol/l, respectively; P < 0.0001). No child presented xerophthalmia; 3.7% (7/188) of the children were malnourished. The presence of fever and/or diarrhea during the 15 days preceding the first blood collection did not affect the +S30DR value. CONCLUSIONS: The prevalence of VAD in the study group was elevated. +S30DR proved to be a good indicator of subclinical VAD in children from an underdeveloped country.

Chest radiography in Portland cement workers.

To investigate the prevalence of pneumoconiosis in Portland cement workers, a controlled cross-sectional survey was conducted. Chest radiographs of approximately 2640 Portland cement workers showed prevalence rates of about 1% for rounded and for irregular small opacities and about 2% for pleural abnormalities. After age and smoking adjustment, the overall prevalences were still significantly elevated over controls, but when examined separately by smoking status, the significant increases were confined to smokers. Although statistically significant, the prevalences were only elevated about 1% in cement workers, compared with controls. A statistically significant relationship with exposure was found for pleural abnormalities but not for rounded or irregular small opacities. Thus a weak association exists between pulmonary radiographic abnormalities and employment in US Portland cement plants, and there appears to be a dose-response relationship between exposure and pleural abnormalities.

Disability and workers' compensation.

Physicians are often requested to provide medical evaluations and opinions about disability. This article presents differing definitions of disability and impairment. It focuses on the specific disability systems known as workers' compensation systems, the roles physicians play in these systems, and the parties involved in workers' compensation systems.

The influence of orthodontic treatment on previously traumatized permanent incisors.

The reaction of previously traumatized teeth to orthodontic force application was investigated. Four groups of children were examined: group T comprised 56 children who encountered trauma to their maxillary incisors; group O comprised 29 orthodontic patients with intact incisors; group TO comprised 28 previously traumatized orthodontic patients; and group C served as the control group (n = 26). Orthodontic treatment was restricted to tipping movement executed only by means of removable appliances. Groups T, O, and TO were followed up longitudinally by means of clinical and radiographic examinations. In most of the cases the reported trauma occurred to teeth with completed roots and affected the crown only. Group TO presented the highest, though relatively moderate, prevalence of root resorption (27.8 per cent) and was followed by groups O and T (6.7 and 7.8 per cent, respectively) while in the control group no resorption was observed. Electrical pulp testing revealed the highest prevalence of loss of tooth vitality in group TO (7.3 per cent) in which the highest prevalence of pulp obliteration was also found. It can be concluded that the combination of trauma with orthodontic tipping renders the teeth more susceptible to complications, especially to root resorption and loss of vitality.

Using PC/GENE for protein and nucleic acid analysis.

This paper describes a series of protein analyses using the molecular biology software package PC/GENE, which runs on an IBM or compatible microcomputer. A nucleic acid sequence was first edited and then translated into an amino acid sequence. The amino acid composition, isoelectric point, molecular weight, and other properties of the sequence were determined. Programs to predict secondary structure, alpha helix membrane associations, hydrophobic and hydrophilic regions, and surface and antigenic sites from the amino acid sequence were also used. A search was made in a data base for sequences containing a region similar to a region in the protein sequence. Sequence alignments and queries of data bases can also be performed.

Symptoms, ventilatory function, and environmental exposures in Portland cement workers.

Data on respiratory symptoms and pulmonary function were obtained for 2736 Portland cement plant workers and 755 controls. Personal dust samples contained a geometric mean concentration of 0.57 mg/m3 for respirable dust and 2.90 mg/m3 for total dust. Cement workers and controls had similar prevalences of symptoms, except that 5.4% of the cement workers had dyspnoea compared with 2.7% of the controls. The mean pulmonary function indices were similar for the two groups. Among cement plant workers, the prevalence of chronic phlegm increased with tenure whereas the prevalence of wheezing increased with both tenure and current dust level. Other symptoms and pulmonary function indices were not significantly related to exposure.

A review of the medical standards for civilian airmen. Synopsis of a two-year study.

This article summarizes the report of a comprehensive review by the American Medical Association (AMA) of the medical standards for civilian airmen. The present standards were promulgated by the Federal Aviation Administration in 1959; the alcoholism and cardiovascular standards were revised in 1982. The AMA report recommends new or revised standards for cardiovascular, mental and behavioral, visual, endocrine, respiratory, hematological, hearing and equilibrium, musculoskeletal, and nervous system disorders. It also provides guidance for the medical certification of airmen with conditions not covered specifically by the standards and recommends a new medical history and examination form for use by aviation medical examiners. Risk factors for the development of sudden incapacitating disease, such as coronary heart disease and stroke, receive special attention. Final standards will be developed by the Federal Aviation Administration.

GEL--a computer tool for DNA sequencing projects.

The GEL program for entry and analysis of DNA sequencing information is discussed, and examples of interaction with the program are presented. The current version of the program represents the last of several revisions to the first GEL program, reported previously in this journal (1). Improvements and additions have been made, making the current GEL a particularly useful laboratory tool for molecular biologists engaged in DNA sequencing projects.

Medical and industrial hygiene characterization of the cotton waste utilization industry.

We studied 260 workers in the cotton waste utilization industry and 310 "blue-collar" control workers from nondusty industries in the same geographic area of the United States by respiratory symptom questionnaire and by pre- and postshift spirometry. We excluded 75 cotton workers and 75 control workers from statistical analysis because of prior hazardous occupational exposures. Plant-wide, 8-hour time-weighted average exposures ranged from 0.28 mg/m3 to 7.80 mg/m3. The overall prevalence of symptoms compatible with byssinosis was 5.9% in cotton workers and 4.7% in the controls. Cotton workers with less than 2 years of employment had a significantly greater prevalence of bronchitis than their control counterparts. The cotton workers with 2 years or more of employment had significantly greater prevalences of bronchitis, shift decrement in forced expiratory volume in 1 second (FEV1) of greater than or equal to 10%, and FEV1/FEV1-predicted less than 80%, than their control counterparts. Regression analysis showed that for matched cotton and control workers, the percentage decrement in FEV1 over the shift was significantly greater for cotton workers; and that in all cotton workers, longevity in industry had a negative effect on the before-shift forced vital capacity (FVC). This study suggests that there are both acute and chronic effects of cotton exposure in the cotton waste utilization industry.

Outbreak of influenza A/USSR/77 at Marquette University.

An outbreak of influenzalike illness occurred at Marquette University, Milwaukee, Wisconsin, in February 1978. Epidemiologic and laboratory data indicate that the outbreak was due to influenza A/USSR/77 (N1H1) virus. A self-administered questionnaire inquiring about the presence and spectrum of illness was given to faculty members, dental students, and residents of an undergraduate dormitory. Age-specific attack rates were 61.5% for persons less than or equal to 22 years of age, 24.7% for those 23 or 24 years of age, and 9.7% for those greater than or equal to 25 years of age. This pattern of age-specific attack rates paralleled the age distribution of persons without hemagglutination-inhibiting antibody to influenza A/USSR/77 virus found in independent serosurveys. Prior swine influenza (H1N1) immunization provided no protection from illness in this outbreak. Past epidemic antibody titers in undergraduates were only weakly associated with clinical illness. The data on disease impact gathered in this study indicate that in a university setting influenza A/USSR/77 virus produced a short-lived outbreak of respiratory illness with a very high attack rate in young adults.