Protein and ribonucleic acid metabolism in the central nervous system of rats during space flight in the "Kosmos-605" satellite]

On the 2nd postflight day the activity of neutral protamine peptide hydrolase of different compartments of the rat brain did not differ from the control level. With respect to the protein and RNA content and concentration motoneurons of anterior horns of the spinal cord and their glial-cells-satellites of rats exposed to the ground-based synchronous experiment did not differ from those of vivarium controls, except cells of the supraoptic nucleus. That was found on the 2nd and 27th postflight days. On the 2nd postflight day the protein and RNA concentration in neurons decreased and the protein concentration and content in gliocytes lowered; the RNA concentration and content in Purkinje cells of the cerebellum became reduced. On the 27th postflight day the RNA concentration in neurons of the supraoptic nucleus remained diminished whereas the protein content increased; in spinal motoneurons the protein concentration decreased and in adjacent gliocytes the protein concentration and content lowered. All the above changes made no more than 15% of the control values.     

Association kinetics with coupled diffusional flows. Special application to the lac repressor--operator system

The time development of the association of the lac repressor to the operator is considered in a model where the repressor is allowed to bind unspecifically to DNA and move along the DNA chain in a one-dimensional diffusion. The coupling to the three-dimensional diffusion outside the chain is introduced by letting the repressor associate and dissociate from the chain until it is finally bound to the operator. All distance correlations along the chain are included. The mean time of association is calculated and through a comparison with experimental data the molecular parameters are determined. The one-dimensional diffusion constant is found to be of the order of 10(-9) cm(2)s(-1). The model is sufficiently general to be applicable to other similar systems.     

How are the retired physicians?

As part of an extensive cross-sectional survey of Norwegian physicians carried out in 1993 the 1,158 retired members of The Norwegian Medical Association were sent a questionnaire about their social situation, work activity, health and well-being. The response rate was 76%. 62% of the respondents were 75 years or older, and 13% were women. 44% were still active, doing clinical, research, or consultation work. The most prevalent complaint was lower back trouble, followed by arthrosis and hypertension. It was relatively common to prescribe one's own drugs. 6-8% of physicians under 75 years and 28% of those over 84 years needed practical help, but the great majority rated their life quality as good or excellent.     

The use of streptokinase preparations in pleural empyema and pyopneumothorax

Prevailing fibrin-formation in the pleural cavity entails hypoactivity of trypsin-like proteinases and a high inhibitory potential in the serum and pleural exudate. Streptokinase preparations appeared an effective means of pharmacological pulmonary decortication in patients with high pleural levels of plasminogen. The authors obtained higher efficacy of conservative therapy for pyothorax when they used a specially designed technique of intrapleural administration of streptokinase-activated fresh frozen plasma of the same group. The outcomes of the disease were also improved noticeably.     

Protection of mice against gastric colonization by Helicobacter pylori by single oral dose immunization with attenuated Salmonella typhimurium producing urease subunits A and B

Helicobacter pylori is a Gram-negative bacterial pathogen associated with gastritis, peptic ulceration, and gastric carcinoma. The bacteria express a strong urease activity which is known to be essential for colonization of gnotobiotic pigs and nude mice. UreA and UreB, two structural subunits of the active enzyme, were expressed in the attenuated Salmonella typhimurium live vaccine SL3261 strain. Evaluation of protection against H. pylori was performed in Balb/c mice by oral immunization with a single dose of the vaccine strain. Five weeks after immunization, mice were challenged orally three times with a mouse-adapted H. pylori wild type strain and, six weeks later, mice were sacrificed to determine H. pylori infection by detection of urease activity from the antral region of the mouse stomachs. In several independent experiments, we observed 100% infection with H. pylori in the non-immunized mice and no infection (100% protection) in the mice immunized with S. typhimurium expressing recombinant UreA and UreB. Specific humoral and mucosal antibody responses against UreA and UreB were observed in mice immunized as indicated by western blots and ELISA assays. These data shows that oral immunization of mice with urease subunits delivered by an attenuated Salmonella strain induced a specific immune response and protected mice against H. pylori colonization. Single oral dose immunization with UreA and UreB delivered by a live Salmonella vaccine vector appears to be an attractive candidate for human vaccination against H. pylori infection. In addition, this model will aid to elucidate the effective protection mechanisms against H. pylori in the gastric mucosa.