Comparative study of the changes in microanatomical organization of lymph nodes located and functioning in the area of venous congestion

By the morphometric method the microanatomical organization of the popliteal and kidney lymph nodes of the type Vi was studied in venous congestion. In the first experimental series (lymph nodes localize in venous congestion area) the venous congestion in the popliteal lymph nodes was created by the ligature of caudal vena cava. In the second experimental series (lymph nodes, which clean the venous congestion area--the kidney vena was tied up. The small and short time increase of the marginal sinus volume and hypertrophy of the medullary cords, which seemed about medullary substance B-zone stimulation were characteristically for the lymph nodes, localize in the venous congestion area. The sharp increase of the marginal sinus volume during the long experimental time and paracortical T-zone hyperplasia were characteristically for the lymph nodes, which clean the venous congestion area.     

Protein factors that bind to the murine 2',5'-oligoadenylate synthetase ME-12 gene 5' upstream regulatory region

The murine 2',5'-oligoadenylate synthetase ME-12 gene regulatory region AB forms six complexes with protein factors in murine BALB/c 3T3 cells as demonstrated by the mobility shift electrophoresis assay under the reaction conditions used. The complexes, designated C1-C6 in order of their decreasing electrophoretic mobility, showed three distinctive specificities with regulatory region AB, element A, and element B as probes or competing DNA: 1) C1 is region AB-specific (this complex did not form with either element A or B used alone or as a mixture); 2) C5 formed both with element A and element B; 3) C2, C3, C4, and C6 formed with element B, but not A. The protein factors that give rise to these complexes show differential DNA binding activities in various buffer solutions at different pH values. The C4-forming protein factor is the interferon (IFN)-alpha/beta-stimulated response factor (ISRF) which shows element B specificity. It preexists in the cytoplasm. ISRF appears to be complexed to an inhibitor (ISRFI) in the cytoplasm and to dissociate from the inhibitor and to translocate into the nucleus upon treatment of cells with IFN-alpha/beta. We propose that IFN-alpha/beta treatment of BALB/c 3T3 can trigger at least two events: 1) loosening of a tight inhibitor-ISRF complex with the release of free ISRF; this may be mediated via phosphorylation of ISRF or ISRFI; 2) translocation of ISRF into the nucleus and binding to the enhancer element B, which results in the activation of 2',5'-oligoadenylate synthetase gene expression.     

The indices of antipneumococcal immunity in children with chronic pneumonia

In 76 children with chronic pneumonia the levels of serum antibodies to pneumococcal capsular polysaccharide antigens (serotypes 1, 3, 6B, 8, 9N, 15F, 23F), O-polysaccharide and pneumococcal protein somatic antigens were determined by ELISA techniques. The study showed that in sick children the content of antipneumococcal antibodies in the blood increased with age. No correlation between the content of total immunoglobulins and that of antipneumococcal antibodies in the blood of the patients was established, but a sharp decrease in the concentration of antibodies was registered in a child with hypoglobulinemia. No increase in the level of antibodies to pneumococcal antigens was observed in cases of the exacerbation of Pneumococcus-induced inflammatory process in the lungs.     

Effect of mastectomy versus mastectomy plus adjuvant ovariectomy on prolactin response to TRH in breast cancer

The endocrine effects of ovariectomy need to be further investigated. The present study was carried out to evaluate the influence of the adjuvant ovariectomy on the mastectomy-induced changes in PRL response to TRH in breast cancer. The study included 34 patients with locally limited breast carcinoma, 18 of whom were treated with radical mastectomy, whereas the other 16 underwent mastectomy plus adjuvant ovariectomy. PRL secretion in response to TRH (200 mcg I.V. as bolus) was evaluated one day before and 7 days after surgery. In patients treated with mastectomy only, PRL increase after TRH was significantly higher after surgery than before. On the contrary, no difference was seen in patients treated with mastectomy plus ovariectomy. This study shows that the adjuvant ovariectomy may block the increase in PRL response to TRH induced by mastectomy in breast cancer.     

Sodium cholate-induced changes in the conformation and activity of rat pancreatic cholesterol esterase

Pancreatic cholesterol esterase (CEase) regulates dietary cholesterol absorption and is activated in the presence of trihydroxy bile salts while remaining inactive monohydroxy bile salts. CEase from rat pancreas has been purified by ammonium sulfate precipitation, hydroxylapatite chromatography, and gel filtration on Sephacryl S-200/S-300 columns connected in series, and its homogeneity and Mr (55,418 +/- 288) have been determined by sedimentation equilibrium centrifugation. The effects of tri-, di-, and monohydroxy bile salts on the conformation of the purified enzyme in buffer solution and in an in vitro assay system were studied by circular dichroism spectropolarimetry. The CD spectrum of the enzyme in solution shows a curve shape suggestive of an alpha-helicity, but low mean residue ellipticity (MRE) values may indicate an important beta-turn contribution. Sodium cholate, a trihydroxy bile salt, induces a decrease in the negative MRE values of the enzyme in solution at bile salt concentrations of 70-100 nM, with no further spectral changes at concentrations as high as 1 mM. Sodium cholate concentrations higher than 1 microM also induce an increase in the enzyme's negative MRE values under activity assay conditions, which reverts toward its original value once the reaction reaches equilibrium. These latter changes are interpreted as induced by substrate binding to the enzyme followed by partial substrate depletion after the reaction reaches equilibrium. Sodium deoxycholate, a dihydroxy bile salt, induces unstable transient increases and decreases in the MRE values of CEase in buffer solution and under activity assay conditions. These changes are bile salt concentration-dependent and may reflect self-association of the protein. Sodium taurolithocholate, a monohydroxy bile salt, does not affect the CD spectrum of CEase, and neither the di- or the monohydroxy bile salt activates the enzyme.     

Side reaction in peptide synthesis. Formation of oxazolidone derivatives

2-Oxazolidone derivatives formed through an intramolecular reaction in the process of alkaline treatment of urethane-type N-protected peptides of which the N-terminal residues were Ser or Thr having unprotected hydroxyl groups. In oder to avoid this side reaction, the esters of these peptides could be cleaved by enzymatic hydrolyses instead of saponification.     

Thermoregulatory responses to acute body heating in rats acclimated to continuous heat exposure

Thermoregulatory responses to an acute heat load with intraperitoneal heating (IH) or indirect external warming (EW) by increasing ambient temperature (Ta) were investigated with direct and indirect calorimetry in rats acclimated to environments of 24.0 degrees C (Cn), 29.4 degrees C (H1), and 32.8 degrees C (H2) for greater than 15 days. The rats were placed in a direct calorimeter where the air temperature was maintained at 24 degrees C for the initial 3 h. IH was then made for 30 min through an electric heater implanted chronically (6.5 W.kg-1) in the peritoneal cavity, and EW was performed by raising the jacket water temperature surrounding the calorimeter from 24 to 39 degrees C (0.19 degrees C.min-1). Hypothalamic (Thy) and colonic temperature immediately before the start of the heat load tended to be higher as the acclimation temperature increased. During IH, the threshold Thy for the tail skin vasodilation (Tth) was significantly higher in H2 than in Cn rats. During EW, however, there was no difference in Tth between the groups. Metabolic heat production (M) was slightly suppressed during IH and significantly depressed only in H2 rats. During EW, M was suppressed in all the groups. The magnitude and duration of suppression were greater in H2 rats than in the other two groups. The responses in nonevaporative heat loss and thermal conductance (C) to the rise in Thy did not differ among the three groups during IH. According to the rise in Thy, however, there was a greater C increase in H2 than in Cn and H1 rats during EW.(ABSTRACT TRUNCATED AT 250 WORDS)     

Marine amoebae from waters of northwest Spain, with comments on a potentially pathogenic euryhaline species

Of 17 species of free-living amoebae identified in various samples of salt water, only 1, Acanthamoeba polyphaga, is known to be a potential pathogen. While no deaths occurred when laboratory animals were inoculated with A. polyphaga to test for pathogenicity, the protozoa were present in the brain, liver and lungs of some but not all of the animals.     

Specific receptors for endothelin on membranes from human placenta. Characterization and use in a binding assay

High-affinity binding sites for endothelin have been found in a human placenta membrane preparation. 125I-endothelin bound to placenta membranes at 20 degrees C with an association half-time of 30 min, whereas the binding was only slowly reversed with a dissociation half-time of 250 min. In saturation experiments, a single class of high-affinity binding sites was identified with an apparent dissociation constant (KD) of 24 pM and a maximal density of 240 fmol per mg of protein. The binding of 125I-endothelin was half-maximally inhibited by cold endothelin at a concentration (IC50) of 140 pM. In contrast, no inhibition was found at 10(-4) M for a variety of vasoactive peptides such as angiotensin II, vasopressin, neuropeptide Y, substance P, CGRP, bradykinin, leucine enkephalin or dynorphin A. Similarly, the binding was modulated neither by the calcium channel blockers nifedipine, verapamil or diltiazem, nor by the calcium channel agonist Bay k 8644. There was also no effect with the structurally-related bee venom apamin. Using this membrane preparation, endothelin-like activity could be measured in the medium of cultured human endothelial cells by competition binding technique.