Immunogenicity of synthetic HIV-1 gp120 V3-loop peptide-conjugate immunogens

A successful prophylactic human immunodeficiency virus type 1 (HIV-1) vaccine must elicit an immune response that will prevent establishment of the persistent viral infection. The only response shown to be effective in this regard is virus-neutralizing antibody directed against the viral gp120 hypervariable V3-loop region. Conjugate immunogens, containing cyclic peptides representing the V3 determinant covalently bound to a carrier protein, were capable of eliciting virus-neutralizing antibodies. The consistency of the response was related to peptide size. The smaller cyclic peptides, expressing relatively conserved sequences from the V3-loop apex, were poor inducers of neutralizing activity. In contrast, the largest cyclic peptides mediated neutralizing responses that were similar to those observed and previously reported for intact gp120 immunogens. A cyclic synthetic peptide expressing most of the prototypic HIV-1 MN variant V3 determinant warrants further study as a potentially effective vaccine immunogen.     

Nitrogen fertilization of wheat under limited water supplies

The effects of the initial amounts of soil nitrate to a depth of 1.2 metres, the addition of N-fertilizer and the water-supply on wheat yield were studied. N response x irrigation experiments were laid out over a field in which there was substantial variation in residual inorganic N and the data analysed by multiple regression. Responses to increased amounts of residual soil nitrate were much less than to freshly applied N fertilizer, and responses to both soil nitrate and freshly applied N fertilizer increased with increasing water supply.     

Myosin heavy chain composition in young and old rat skeletal muscle: effects of endurance exercise

The objective of this study was to determine the effects of age and exercise on the myosin heavy chain (MHC) composition of skeletal muscle. Young (3 mo) and old (22 mo) female specific pathogen-free barrier-reared Fischer 344 rats were randomly assigned to young untrained or young trained and old untrained or old trained groups, respectively. Young trained and old trained animals performed endurance exercise training on a motorized treadmill for 8 wk. Succinate dehydrogenase activity and MHC isoforms were measured in the plantaris (Plan), lateral and medial gastrocnemius (Gast), and soleus (Sol) muscles. In sedentary animals, aging resulted in a decrease (P < 0.05) in type IIb MHC and an increase (P < 0.05) in type IIa MHC in both the Gast and Plan muscles. Also, aging resulted in a small but significant increase (approximately 4%; P < 0.05) in type I MHC in the Sol. Exercise training resulted in significant (P < 0.05) increases in Gast, Plan, and Sol succinate dehydrogenase activity in both young and old animals. Furthermore, exercise training resulted in a decrease (P < 0.05) in the percentage of type IIb MHC and an increase (P < 0.05) in the percentage of type IIa MHC in the Plan in both young and old animals. These data suggest that there is an age-related shift in locomotor muscle MHC isoforms from a faster to a slower isoform.     

Diagnosis and treatment of complicated pancreatic cysts

The results of the treatment of 18 cases with complicated pancreatic cysts (11 men and 7 women) were studied. Good results were obtained after cystectomy and resection of the pancreas together with the cyst, when the latter was uncomplicated. With complications, external and more seldom internal drainage were preferred. In the postoperative period 3 patients developed persistent pancreatic fistula, one patient developed malignization of the cyst and another one -- thrombosis of the splenic vein.     

Expression of the conditioned NK cell activity is beta-endorphin dependent

We are interested in identifying the pathways which are responsible for triggering the conditioned enhancement of natural killer (NK) cell activity. Earlier studies have suggested that central opioid(s) are involved in eliciting the expression of the conditioned NK cell activity. The purpose of this study was to identify the central opioid peptides that allow the central nervous system (CNS) to communicate with the immune system. Mediators that activate the efferent pathway of communication between the CNS and immune system was examined by injection of the mediator via the cisterna magna (CM). Conditioning was used as a tool to show that the bi-directional communication between the CNS and the immune system does take place. We found that beta-endorphin but not dynorphin could stimulate NK cell activity, when beta-endorphin or dynorphin was injected into the CM. In addition, when anti-beta-endorphin or anti-dynorphin antibody was injected into the conditioned animals via CM the conditioned response was blocked by anti-beta-endorphin but not by anti-dynorphin antibody. These observations suggest that beta-endorphin appears to be one of the signals that is induced in the brain at the CS recall step of the conditioned response to trigger the elevation of NK cell activity.