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Biomedical subjects

J Le Roux

Publications and source records attributed to J Le Roux.

8 recordsLinked to original sources
PubMed1999

[Quality of sleep and periodic breathing in healthy individuals working at an altitude of 3700 meters].

We performed full polysomnography (PSG) in 7 healthy miners of Kyrghyz origin (mean age 25 +/- 6 years) working in 2 weeks shifts at Kumtor gold mines at the elevation of 4200 m. They slept in comfortable dormitories situated at 3700 m. To avoid acute mountain sickness all subjects received acetazolamide 3 x 0.25 daily during 2 days preceding ascent and during 2 days at altitude: PSG was performed three times: at 760 m (1) and on the 1st (2) and 7th night (3) after rapid ascent (aircraft) to high altitude using SomnoTrac 4250 sleep laboratory. We found that sleep efficiency was good at lowland and in the mountains averaging 81.79% and 84% respectively. Although there were no significant differences in percentage of sleep stages and of total sleep time between lowland and both nights at high altitude, arousals and awakenings were more frequent in the mountains. Episodes of periodic breathing (PB) appeared at high altitude. There was a large individual variability in PB on both nights at altitude. The time spent in PB ranged from 4 to 30 minutes during the first night at altitude and from 3 to 17 minutes during the second one. PB appeared mainly during non-REM sleep and aggravated arterial blood desaturation.

Adult↗
PubMed1998

Airborne movement of anthrax spores from carcass sites in the Etosha National Park, Namibia.

Tests for airborne movement of anthrax spores downwind from three heavily contaminated carcass sites were carried out under a range of wind conditions. Anthrax spores were detected in just three of 43 cyclone or gelatin filter air samples taken at distances of 6, 12 and 18 m from the sites. In addition, nine positives resulted during sampling sessions in which the site was mechanically disturbed, with a further five positives being found in sessions subsequent to those in which the site had been disturbed. The three positive samples not related to man-made disturbance were associated with the highest winds experienced during the study. Despite colony counts exceeding 100 on the culture plates in three instances, calculations showed that these represented very low worst case probable spore inhalation rates for animals or humans exposed to such levels. The low number of positives, the clear pattern of rapidly declining numbers of anthrax spores with distance downwind from the centres of the sites apparent on settle plates, and the persisting levels of contamination despite wind and rain, collectively suggest that the anthrax spores were associated with fairly heavy particles, although this was not seen by electron microscopy on soil samples from the sites. Overall, the findings are interpreted as indicating that it is very unlikely that Etosha animals contract anthrax by the inhalation route while simply in transit near or across a carcass site. The significance of the observations in relation to weather conditions in the Etosha, other studies on particulate aerosols in the region, and reports of long-distance airborne movement of microbes, is discussed.

Air Microbiology↗
PubMed1996

Street children in South Africa: findings from interviews on the background of street children in Pretoria, South Africa.

In the present study findings from interviews on the background of street children in Pretoria, South Africa are presented, discussed, and compared with research done in the past on South African street children. Findings from the investigation indicate that the average age of South African street children is approximately 13 years, predominantly of male African origin. Most have been on the streets for three years or longer, and they cited family violence, parental alcoholism, abuse, and poverty as the main motivating factors for leaving home. Most of these findings are common among street children all over the world.

Adolescent↗
PubMed1986

Calcitonin-secreting carcinomas of the prostate. An immunohistochemical and ultrastructural analysis.

Two cases of calcitonin-producing carcinomas of the prostate are reported. Light microscopical, immunohistochemical, and ultrastructural investigations have been performed. These tumors displayed a remarkable dual, endocrine and common epithelial (exocrine), differentiation. However, they presented two different architectural growth patterns. Of particular interest, numerous calcitonin cells were immunocharacterized. In addition, the endocrine component could harbour carcinoembryonic antigen, serotonin, human chorionic gonadotrophin, and prostate-specific acid phosphatase immunoreactive cells. Ultrastructural analysis confirmed the presence of numerous endocrine cells. These findings are not unexpected, since calcitonin, serotonin, and human chorionic gonadotrophin immunoreactive cells are normal and constitutive inhabitants of prostate gland. In the current cases, calcitonin cells showed a strong carcinoembryonic antigen immunoreactivity, as observed also in thyroidal C-cells. This peculiar kind of prostatic carcinoma might be compared to certain thyroidal tumors of intermediate type coupling parafollicular and follicular differentiation.

Acid Phosphatase↗
PubMed1975

[Functional treatment of fractures of the mandibular condyle and its neck].

The functional treatment of condylar and sub-condylar fractures requires very early mobilisation of the mandible, in protraction. This form of treatment, suggested in France since 1928 by L. Lebourg, is usually carried out with the aid of traction using a plaster helmet. The authors use more simple inter-maxillary traction (as parallel as possible from the standpoint of occlusion) followed by propulsion plates.

Adolescent↗