Work with video display terminals among office employees. IV. Refraction, accommodation, convergence and binocular vision.

The present study is the fourth of a major epidemiologic health investigation on work with a video display terminal (VDT). The other studies showed that VDT operators replying to questionnaires have more eye discomfort than a reference group of office employees not employed in VDT work and that women have more eye discomfort, musculoskeletal complaints, headache, and skin disorders than men. Routine ophthalmologic examinations failed to establish any appreciable differences between the groups; for example, the prevalence of myopia was the same.

Work with video display terminals among office employees. III. Ophthalmologic factors.

The present ophthalmologic study is the third part of a major epidemiologic health investigation on work with a video display terminal (VDT). An initial study showed that VDT operators replying to a questionnaire reported more eye discomfort than a reference group not employed in VDT work and that women reported more eye discomfort, musculoskeletal discomfort, headache, and skin disorders than men, irrespective of whether or not they were employed in VDT work. In the present study the ophthalmologic history of eye diseases and eye discomfort yielded a much lower percentage response for symptoms and discomfort than the questionnaire, and, just as with visual acuity and refraction, there was no difference between the exposed and reference groups or between the men and women.

Working with cathode-ray tube based visual display units.

Eye strain when working with visual display units might be due to bad ergonomics but also to eye functions not meeting the demands. If the symbol on the screen has a 4 mm height and the working distance is 60 cm, a visual acuity of 0.4 is required.

Investigation of visual strain experienced by microscope operators at an electronics plant.

This investigation was concerned with the examination of 75 microscope operators at an electronics plant, with reference to eye function and visual strain. It consisted of three separate parts: (1) standardised interviews dealing with symptoms of visual strain, (2) examinations of the refractive state as well as possible diseases of the eye, and (3) examination of binocular vision. It emerged that 80% of the microscope operators engaged in full time microscope operation experienced various symptoms of visual strain.

Distribution of insertion element IS1 in natural isolates of Escherichia coli.

Total DNAs from twelve natural isolates of Escherichia coli from animals and humans were examined by hybridization with a probe for IS1. Considerable variation in copy number was found. In the case of two strains isolated from the same individual, one strain contained no copies of IS1 and the other, much greater than 30.

Distribution of the insertion sequence IS1 in gram-negative bacteria.

Translocation of DNA segments is a recombinational event seen in both eukaryotic and prokaryotic chromosomes, and it is thought to be involved in controlling gene expression and in the evolution of chromosomes. In bacteria, insertion (IS) and transposable (Tn) elements not only translocate their own DNA, but also promote the rearrangement of both bacterial chromosomes and the plasmic genomes carrying them. The insertion element IS1 is one such element which is 768 base pairs long.

Pulse methylprednisolone in rheumatoid arthritis: a double-blind cross-over trial.

Ten patients with rheumatoid arthritis unresponsive to conventional therapy participated in a double-blind cross-over trial in which they randomly received either a "pulse" or 1 g of methylprednisolone or placebo, intravenously, once a month for 6 months. Both the drug-first and placebo-first groups had the same mean American Rheumatism Association functional classification, 2.5.

A modified letter matching chart for testing young children's visual acuity.

A new chart for testing children's visual acuity was designed. It was based on the matching principle and showed rows of the four letters H, O, T, and V at a distance of 3 m. A geometric progression of leter size was used.

Genetic determination of lipopolysaccharide: locus of O-specific unit polymerase in group E of salmonella.

By genetic analysis of a semirough mutant of Salmonella muenster we show that a gene determining the polymerization of the repeating units of the O-3, 10-type lipopolysaccharide side chain in Salmonella of group E resides in the his-linked rfb cluster.

Thoracic duct drainage in SLE with cutaneous vasculitis. A case report.

A 25-year-old woman had systemic lupus erythematosus manifested primarily by severe cutaneous vasculitis that was unresponsive to oral prednisone and azathioprine. She was treated with thoracic duct drainage (TDD). Her course was followed by serial photographs, skin biopsies, and serum immunoglobulin, antinuclear antibody, and complement levels.

Pneumatosis cystoides intestinalis. Treatment with oxygen via close-fitting mask.

Four patients with pneumatosis cystoides intestinalis were recently treated with oxygen via a close-fitting mask. They responded initially to this therapy, with cessation of all symptoms and, after seven days of treatment, with return of proctoscopic and barium-contrast roentgenographic findings in the colon to normal. However, the disease recurred in one of the four patients after six months.

Genetic mapping of the antigenic determinants of two polysaccharide K antigens, K10 and K54, in Escherichia coli.

The genes controlling synthesis of the Escherichia coli acidic polysaccharide capsular antigens K10 and K54 were transferred by conjugation to E. coli strains of other serotypes. The genes concerned with these K antigen determinants showed genetic linkage with the serA locus.