The effect of mammalian anxiety factors on insects. The action of the corticoliberin 2-4 fragment on the behavior of the mealworm beetle Tenebrio molitor

The effect of the corticoliberin 2-4 fragment--tripeptide Pro-Pro-Ile (PPI) inducing increase in epileptiform activity of mammal on T. molitor males behaviour has been studied. The "open field" method modified for insects has been used. PPI in doses of 30, 60, 100, 1000 micrograms/kg was injected in hemolymph of the beetles. The horizontal activity (HA), number of turns (TN) and other parameters were registered during 6 min. The tripeptide in dose 30 micrograms/kg was non-effective. PPI in doses 100 and, especially, 1000 micrograms/kg evoked stable decrease in HA that was observed as early as 0.5 h after injection. This effect lasted throughout 4-24 hrs and, apparently, induced by nonspecific action of high doses of the peptide. PPI in dose 60 micrograms/kg produced the significant intensification of stressogenic influence of experimental situation: in 2-4 hrs after injection the level of HA and TN increased. It is suggested that PPI can be regarded as an anxiogenic factor of insects.     

Effect of perturbations in the electrode wire feed system on the quality of welded joints

Composite gallium solder pastes for low-temperature diffusion soldering of cermet sections are investigated. The compositions of the solders and the properties of the joints are presented. The effect of the soldering conditions on the mechanical properties of the solders is investigated.     

Current aspects in the diagnosis and treatment of chronic cystitis in women

Chronic cystitis (CC) in females is annually encountered now in 15,000-20,000 per 1,000,000. Etiological and pathogenetic factors in CC are closely related. Bacteriologically, CC is represented primarily by Enterobacter. The infection, as a rule, ascends the lower urinary tracts. The contributing factors are: weak local antibacterial mechanisms of the urogenital system, anatomical variants and anomalies of the urethra and introitus, sexual activity, impaired urodynamics of the lower urinary tracts. The diagnosis of chronic inflammation of the bladder is made mainly endoscopically, with obligatory endovesical multifocal biopsy of the bladder followed by histological examination. The treatment of CC includes antibacterial, general and local antiinflammatory therapy, measures to normalize urodynamics of the lower urinary tracts, correction of hygienic and sexual factors, immunostimulation. 16 nonresponders to conservative treatment of interstitial cystitis with progressive contraction of the bladder were subjected to supratrigonal or subtotal resection of the bladder with one-stage ileocystoplasty.     

Empirical solvent-mediated potentials hold for both intra-molecular and inter-molecular inter-residue interactions

Whether knowledge-based intra-molecular inter-residue potentials are valid to represent inter-molecular interactions taking place at protein-protein interfaces has been questioned in several studies. Differences in the chain connectivity effect and in residue packing geometry between interfaces and single chain monomers have been pointed out as possible sources of distinct energetics for the two cases. In the present study, the interfacial regions of protein-protein complexes are examined to extract inter-molecular inter-residue potentials, using the same statistical methods as those previously adopted for intra-molecular residue pairs. Two sets of energy parameters are derived, corresponding to solvent-mediation and "average residue" mediation. The former set is shown to be highly correlated (correlation coefficient 0.89) with that previously obtained for inter-residue interactions within single chain monomers, while the latter exhibits a weaker correlation (0.69) with its intra-molecular counterpart. In addition to the close similarity of intra- and inter-molecular solvent-mediated potentials, they are shown to be significantly more residue-specific and thereby discriminative compared to the residue-mediated ones, indicating that solvent-mediation plays a major role in controlling the effective inter-residue interactions, either at interfaces, or within single monomers. Based on this observation, a reduced set of energy parameters comprising 20 one-body and 3 two-body terms is proposed (as opposed to the 20 x 20 tables of inter-residue potentials), which reproduces the conventional 20 x 20 tables with a correlation coefficient of 0.99.     

Blockade of the voltage-gated potassium channel Kv1.3 inhibits immune responses in vivo

The voltage activated K+ channel (Kv1.3) has recently been identified as the molecule that sets the resting membrane potential of peripheral human T lymphoid cells. In vitro studies indicate that blockage of Kv1.3 inhibits T cell activation, suggesting that Kv1.3 may be a target for immunosuppression. However, despite the in vitro evidence, there has been no in vivo demonstration that blockade of Kv1.3 will attenuate an immune response. The difficulty is due to species differences, as the channel does not set the membrane potential in rodent peripheral T cells. In this study, we show that the channel is present on peripheral T cells of miniswine. Using the peptidyl Kv1.3 inhibitor, margatoxin, we demonstrate that Kv1.3 also regulates the resting membrane potential, and that blockade of Kv1.3 inhibits, in vivo, both a delayed-type hypersensitivity reaction and an Ab response to an allogeneic challenge. In addition, prolonged Kv1.3 blockade causes reduced thymic cellularity and inhibits the thymic development of T cell subsets. These results provide in vivo evidence that Kv1.3 is a novel target for immunomodulation.     

The use of mountain air therapy for the correction of acid formation in patients with hypo- and hyperacidic syndromes

In a consecutive series of 326 patients with primary lung cancer, sarcoid reactions were observed in the regional lymph node or resected lung in 7 patients (2.2%). The average age of the 7 patients, 4 males and 3 females, was 54 years, range 45-70. All the patients underwent lobectomy. The sites in which sarcoid reactions were found were the regional lymph node (N) in 3 patients, the lung parenchyma (L) in 2, N and L in 1, and the tumor stroma in 1. The histologic types were adenocarcinoma in 4 patients, squamous cell carcinoma in 2, and small cell carcinoma in 1. Two patients died of recurrence and myocardial infarction, and five patients are alive, range 5-64 months. The patients with lung cancer complicating sarcoid reactions were significantly younger than the control group (p<0.01), and not significant in prognosis. We conclude that the complication of sarcoid reactions do not influence the prognosis, but that the sarcoid reactions may be a local reaction or resistance to cancer cells.     

Blood-brain barrier transport of amino acids in healthy controls and in patients with phenylketonuria

Blood-brain barrier permeability to phenylalanine and leucine in four patients with phenylketonuria and in four volunteers was measured five times by the double-indicator method at increasing plasma concentrations of phenylalanine. Based on the permeability-surface area product (PS) from blood to brain (PS1) and on plasma phenylalanine levels, Vmax and the apparent Km for phenylalanine were determined. Statistically significant relationships between plasma phenylalanine and PS1 were established in three out of four volunteers, the average Vmax value being 46.7 nmol/g per min and the apparent Km 0.328 mmol/L. Owing to saturation of the carrier, such a relationship could not be established in the patients. In phenylketonuria, PS1 for phenylalanine and leucine decreased significantly by 55% and 46%, respectively. Transport from brain back to blood, PS2, decreased significantly and cerebral large neutral amino acid net uptake was generally decreased in patients with phenylketonuria. In conclusion, the transport of L-phenylalanine across the human blood-brain barrier follows Michaelis-Menten kinetics. In phenylketonuria, brain permeability to large neutral amino acids is reduced by about 50% and net uptake appears decreased.