Lipopolysaccharide-dependent and lipopolysaccharide-independent pathways of monocyte desensitisation to lipopolysaccharides

The present study demonstrates that with time in culture blood monocytes (MO) lose their ability to express procoagulant activity (PCA) and secrete tumor necrosis factor-alpha (TNF alpha) in culture medium in response to lipopolysaccharide (LPS) stimulation. Thus, upon 10 micrograms/ml LPS stimulation for 4 hours 2-day-old MO produced lower levels of PCA and TNF alpha than fresh MO. The decrease in responsiveness was not caused by cell death, since in the case of TNF alpha it was fully reversible by interferon-gamma (IFN-gamma). Compared with cells pre-incubated in medium alone, the responsiveness of MO pre-incubated in LPS was further decreased. Thus, in MO LPS pre-incubation was followed by an LPS refractory state. It was expected that the decrease in responsiveness induced by cultivation in medium alone was mediated by LPS contamination of culture medium. However, as we were unable to prevent this decrease by neutralizing LPS contamination of the culture medium with polymyxin B, the loss in LPS-induced activities of cultured MO is likely to be mediated by culture conditions other than LPS contamination. Taken together the present data demonstrate that LPS-dependent as well as LPS-independent pathways of MO desensitization to LPS exist.     

Changes in tissue energy metabolism in animals exposed to continuous and interrupted low-frequency vibration

The action of continuous low-frequency vibration on rats for 1 month caused no changes in the total adenine nucleotides of the brain but led to a marked decrease in the ATP content and total adenine nucleotides in the limb muscles. After exposure to vibration for 3 months considerable exhaustion of the total adenine nucleotides of both muscles and brain was found. In the case of interrupted exposure to vibration the state of the adenine-nucleotide system depended on the duration of the pauses between periods of continuous exposure to vibration. During vibration with the shortest pauses (4 min) between successive periods of 30 min of vibration no changes were observed in the energy metabolism of the muscles and brain. Vibration with pauses of 8 and 15 min was found to be unfavorable for the adenine nucleotides of the muscles and vibration with a pause of 8 min for the brain.Kiev Institute of Work Hygiene and Occupational Diseases, (Presented by Academician of the Academy of Medical Sciences of the USSR L. I. Medved'.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 7, pp. 35–38, July, 1978.     

Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations

It has previously been shown that, in the heterozygous state, mutations in the SOX9 gene cause campomelic dysplasia (CD) and the often associated autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one recurrent mutation were characterized in one SOX9 allele each, and in one case, no mutation was found. Four missense mutations are all located within the high mobility group (HMG) domain. They either reduce or abolish the DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense and three frameshift mutations identified, two leave the C-terminal transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or almost completely intact. When tested in cell transfection experiments, the recurrent nonsense mutation Y440X, found in two patients who survived for four and more than 9 years, respectively, exhibits some residual transactivation ability. In contrast, a frameshift mutation extending the protein by 70 residues at codon 507, found in a patient who died shortly after birth, showed no transactivation. This is apparently due to instability of the mutant SOX9 protein as demonstrated by Western blotting. Amino acid substitutions and nonsense mutations are found in patients with and without XY sex reversal, indicating that sex reversal in CD is subject to variable penetrance. Finally, none of 18 female patients with XY gonadal dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP assays, providing evidence that SOX9 mutations do not usually result in XY sex reversal without skeletal malformations.      

Effect of α1-protease inhibitor (α1-antitrypsin on the intensity of transformation of phytohemagglutinin-stimulated lymphocytes

₁-Antitrypsin (₁-AT) reduces the intensity of transformation of human peripheral blood lymphocytes stimulated by phytohemagglutinin. The degree of inhibition is determined by the antiprotease activity of the ₁-AT. Maximal inhibition of transformation was shown to be 50%. Participation of ₁-AT in the control of activity of lymphoid tissue cells is postulated.Laboratory of Immunogenetics, Research Institute of Transplantology and Artificial Organs, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 1, pp. 35–36, January, 1980.     

Islet-cell aggregates: Structure and insulin-producing activity during in vitro culture

Research Institute of Transplantology and Artificial Organs, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 12, pp. 650–653, December, 1990.     

Risk factors in sudden infant death syndrome

Preterm babies are at risk of sudden death. Determination of the risk factors and prediction of the probability of sudden death syndrome in infants will help the physicians in purposeful observation of the risk-group children, improve the efficacy of prophylactic check-ups, and decrease neonatal mortality. A prognostic table for rapid diagnosis of the risk of sudden death syndrome is proposed for practical public health.     

State of occupationally significant visual function in locomotive team personnel working in radioactive pollution areas

Long exposure to small radio activity doses have no impact on the acuity of photopic and mesopic vision, on the resistance of eyes to glare, and on the rapidity of color differentiation, which remain to be at the high level that meets medical requirements for the professional abilities of locomotive workers.