Isolation and refined regional mapping of expressed sequences from human chromosome 21

To increase candidate genes from human chromosome 21 for the analysis of Down syndrome and other genetic diseases localized on this chromosome, we have isolated and studied 9 cDNA clones encoded by chromosome 21. For isolating cDNAs, single-copy microclones from a chromosome 21 microdissection library were used in direct screening of various cDNA libraries. Seven of the cDNA clones have been regionally mapped on chromosome 21 using a comprehensive hybrid mapping panel comprising 24 cell hybrids that divide the chromosome into 33 subregions. These cDNA clones with refined mapping positions should be useful for identification and cloning of genes responsible for the specific component phenotypes of Down syndrome and other diseases on chromosome 21, including progressive myoclonus epilepsy in 21q22.3.     

Contrast nephrotoxicity: predictive value of urinary enzyme markers in a rat model

Asbestos, proven to be carcinogenic in humans and animals, is reported to have no genotoxic effect. Asbestos workers have an increased risk of lung cancer, mesothelioma, and other tumours. Earlier findings showed that crocidolite can induce DNA strand breaks in cultured rat embryo cells as assessed by nick translation. We investigated DNA double-strand breaks in white blood cells (WBC) of ten workers occupationally exposed to asbestos. According to our results, obtained with neutral filter elution, individuals who had been exposed to asbestos fibres showed two to four times more DNA double-strand breaks (dsb) in white blood cells than ten non-exposed persons. The induced DNA fragments are of about 250 kb (compared to chromosomal DNA of Saccharomyces cerevisiae standard marker). Using additionally the chromosomal DNA protective method of agarose-plugs, DNA fragments in the range of 200 to 1000 kb have been found in the white blood cells of the same ten workers occupationally exposed to asbestos. In the white blood cells of non-exposed subjects no DNA fragments could be detected with this method. Compared to 51 non-exposed persons, elevated anti-ds DNA antibody concentrations were found in ten workers occupationally exposed to asbestos. The fact that workers occupationally exposed to asbestos have distinctly more double-strand breaks and anti-ds DNA antibodies could mean that an increased incidence of DNA-fragments may be an important indicator in the chronic effect of asbestos-associated carcinogenesis. Apparently, the chronic effects of asbestos observed here do not seem to be identical with that of previously reported acute in vitro effects.     

Analysis of lung tumor risks in rats exposed to radon

This article measures the racial disparities in home ownership and home equity among preretirement-aged households. It computes the proportion of the racial gap explained by discrimination in housing and credit markets. Maximum likelihood and nonlinear least squares estimates are obtained for models of home ownership probabilities and home equity, conditional on home ownership, yielding computations for expected home equity for black and white households. The results reveal an average discriminatory gap in expected home equity as a percent of the actual gap of 55%. In the top third of the family income distribution, the measured discriminatory gap is 82%; in the middle third it is 83%; in the lowest third it is 62%.     

Labial fusion in a pubertal girl: a case report

An 18-year-old virgin, pubertal girl was treated for abnormal menses and dysmenorrhea. She had no history of trauma, sexual infection, or abuse. Occlusion of the introitus of the vagina had been first diagnosed 10 years earlier. The patient presented with fusion of the labia minora in the midline, posteriorly. Her physical examination, ultrasonographic laboratory examination, and intravenous pyelogram were all normal. Following surgical treatment, she had no problems at the time of postoperative follow-up.     

Biochemical reaction products of nitric oxide as quantitative markers of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare and fatal disease of unknown etiology. Inflammatory oxidant mechanisms and deficiency in nitric oxide (NO) have been implicated in the pathogenesis of pulmonary hypertension. In order to investigate abnormalities in oxidants and antioxidants in PPH, we studied intrapulmonary NO levels, biochemical reaction products of NO, and antioxidants (glutathione [GSH], glutathione peroxidase [GPx], and superoxide dismutase [SOD]) in patients with PPH (n = 8) and healthy controls (n = 8). Intrapulmonary gases and fluids were sampled at bronchoscopy. Pulmonary hypertension was determined by right-heart catheterization. NO and biochemical reaction products of NO in the lung were decreased in PPH patients in comparison with healthy controls (NO [ppb] in airway gases: control, 8 +/- 1; PPH, 2.8 +/- 0. 9; p = 0.016; and NO products [microM] in bronchoalveolar lavage fluid [BALF]: control, 3.3 +/- 1.05; PPH, 0.69 +/- 0.21; p = 0.03). However, GSH in the lungs of PPH patients was higher than in those of controls (GSH [microM] in BALF: 0.55 +/- 0.04; PPH, 0.9 +/- 0.1; p = 0.015). SOD and GPx activities were similar in the two groups (p >/= 0.50). Biochemical reaction products of NO were inversely correlated with pulmonary artery pressures (R = -0.713; p = 0.047) and with years since diagnosis of PPH (R = -0.776; p = 0.023). NO reaction products are formed through interactions between oxidants and NO, with the end products of reaction dependent upon the relative levels of the two types of molecules. The findings of the study therefore show that NO and oxidant reactions in the lung are related to the increased pulmonary artery pressures in PPH.     

Endolaser photocoagulation after vitrectomy on rabbit's eyes

Ophthalmoscopic and histopathologic studies of endolaser photocoagulation after vitrectomy were carried out on rabbit's eyes. The endoprobe was connected to the Coherent "Novus 2,000" argon laser system. Under appropriate application the grayish white retinal lesions produced by argon green and argon all wavelength endolaser photocoagulation were similar ophthalmoscopically at a treatment power of 80-100 mw and exposure duration of 0.2s. Histopathologically, the characteristic changes of the retinal lesions produced by argon all wave-length were more significant than that produced by argon green endolaser photocoagulation. Scattered retinal photocoagulation can be done when the opaque medium is cleared on the operating table.