The effect of continuous human lymphokine treatment on skin graft rejection in mice.

Continuous intraperitoneal treatment with human lymphokines produced by Con-A stimulated peripheral human lymphocytes caused the acceleration of skin graft rejection in mice.     

Effect of sympathomimetic substances and analogues on tail absorption of frog larva

Similarly to the effect of T3, the tail absorption of frog larvae (Rana arvalis) was stimulated in vitro by the sympathomimetic agents adrenaline, isoproterenol, ephedrine and the adrenaline analogue MMT. The effect of T3 administration was not inhibited by adrenaline, isoproterenol and MMT, but it was by ephedrine and T3 pretreatment. The adrenaline and isoproterenol effect manifested itself after early administration, but not after late and while ephedrine and MMT were effective at long-term administration, even it administered at a later time. Our experiments draw attention to the metamorphotic effect of substances capable of binding to beta-receptors. Their effect may be explained partly by the increase in the cAMP level, partly by a relationship existing between the beta-receptor and the T3 receptor.     

Oxidative/Nitrative Stress and Inflammation Drive Progression of Doxorubicin-Induced Renal Fibrosis in Rats as Revealed by Comparing a Normal and a Fibrosis-Resistant Rat Strain

Chronic renal fibrosis is the final common pathway of end stage renal disease caused by glomerular or tubular pathologies. Genetic background has a strong influence on the progression of chronic renal fibrosis. We recently found that Rowett black hooded rats were resistant to renal fibrosis. We aimed to investigate the role of sustained inflammation and oxidative/nitrative stress in renal fibrosis progression using this new model. Our previous data suggested the involvement of podocytes, thus we investigated renal fibrosis initiated by doxorubicin-induced (5 mg/kg) podocyte damage. Doxorubicin induced progressive glomerular sclerosis followed by increasing proteinuria and reduced bodyweight gain in fibrosis-sensitive, Charles Dawley rats during an 8-week long observation period. In comparison, the fibrosis-resistant, Rowett black hooded rats had longer survival, milder proteinuria and reduced tubular damage as assessed by neutrophil gelatinase-associated lipocalin (NGAL) excretion, reduced loss of the slit diaphragm protein, nephrin, less glomerulosclerosis, tubulointerstitial fibrosis and matrix deposition assessed by periodic acid–Schiff, Picro-Sirius-red staining and fibronectin immunostaining. Less fibrosis was associated with reduced profibrotic transforming growth factor-beta, (TGF-β1) connective tissue growth factor (CTGF), and collagen type I alpha 1 (COL-1a1) mRNA levels. Milder inflammation demonstrated by histology was confirmed by less monocyte chemotactic protein 1 (MCP-1) mRNA. As a consequence of less inflammation, less oxidative and nitrative stress was obvious by less neutrophil cytosolic factor 1 (p47^phox) and NADPH oxidase-2 (p91^phox) mRNA. Reduced oxidative enzyme expression was accompanied by less lipid peroxidation as demonstrated by 4-hydroxynonenal (HNE) and less protein nitrosylation demonstrated by nitrotyrosine (NT) immunohistochemistry and quantified by Western blot. Our results demonstrate that mediators of fibrosis, inflammation and oxidative/nitrative stress were suppressed in doxorubicin nephropathy in fibrosis-resistant Rowett black hooded rats underlying the importance of these pathomechanisms in the progression of renal fibrosis initiated by glomerular podocyte damage.     

Isolation of nuclei from Aspergillus nidulans protoplasts

Intact nuclei were isolated from the protoplasts of the filamentous fungus Aspergillus nidulans. The large amounts of protoplasts required for such nuclear preparations were produced from young mycelia grown in liquid culture. For final purification of the crude nuclear fraction, a Nycodenz density-gradient centrifugation was applied. The resulting nuclei were of good purity and morphological state, as demonstrated by fluorescence microscopy and electronmicroscopy. The weight ratio of DNA:RNA:protein was 1:3.0:10.8 in the nuclear fraction.     

Baker’s yeast mediated preparation of (10-alkyl-10H-phenothiazin-3-yl)methanols

A series of 10-alkyl-10H-phenothiazine-3-carbaldehydes (2a–h) were obtained by Vilsmeier–Haack formylation from the corresponding 10-alkyl-10H-phenothiazines (1a–h) and reduced to (10-alkyl-10H-phenothiazine-3-yl)methanols (3a–h) by two alternative methods. The baker’s yeast catalyzed reaction proved to be superior over the NaBH₄ reduction and yielded the desired 3-hydroxymethylphenothiazines (3a–h) almost quantitatively.     

High-frequency occurrence of virus-like particles with double-stranded RNA genome in Fusarium poae

Abstract Fifty-five geographically different strains of Fusarium poae were assayed for the presence of extrachromosomal nucleic acid elements. All strains were found to harbour double-stranded RNA (dsRNA) elements and encapsidated virus-like particles (VLP). There were great individual differences in dsRNA patterns of the various strains, but numbers and sizes characteristic for a given isolate remained unchanged after repeated subculturing of the fungi. Morphological alterations or signs of degeneration were not observed in dsRNA-containing isolates. This is the first report on the ubiquitous occurrence of dsRNAs in a hyphomycete fungus species.     

Imprinting with oxytocin and vasopressin in Chang liver cell cultures: hormonal overlap, binding and influence on cell division

In Chang liver cells the administration of oxytocin and vasopressin as well as the combined application of the two hormones will result in a positive binding imprinting for oxytocin and a negative binding imprinting for vasopressin. The hormones are able to increase the mitotic capacity of the liver cells even without previous imprinting, both in the case of treatment for 4 hours and for 24 hours; the change, however, is more marked in the case of treatment for 4 hours. Treatment for 24 hours results also in some functional imprinting.     

Influence of hormone treatment applied or begun in different phases of the cell cycle on hormonal imprinting in Tetrahymena

Primary exposure to a hormone (hormonal imprinting) alters--in the case of the Tetrahymena increases--cellular response to re-exposure(s) to the same hormone. The intensity of hormonal imprinting depends on the phase of the cell cycle in which the primary exposure has taken place. The effect of imprinting was greater on the cells exposed to the hormone in phase G1 than on those exposed in phase S or G2. The response pattern of the progeny generations corresponded to that of the primarily exposed (imprinted) ancestor cell, irrespective of their own pre-exposure in phase G1, G2 or S of their cycle.     

Influence of endocytosis-stimulating hormones on the protein binding capacity of the cell membrane

Histamine and serotonin enhanced the adsorption of fluorescein isothiocyanate (FITC)-labelled bovine serum albumin (BSA) to the membrane of Tetrahymena in a statistically significant and biologically relevant degree, while the similar action of insulin and epinephrine was not significant in either respect. The degree of hormonal influence on BSA-binding was similar to that exerted by the same hormones on the phagocytosis of protozoa in earlier studies. This supports the hypothetical implication that enhancement of protein adsorption to the cell membrane is an important element in the endocytosis stimulating action of histamine and serotonin.     

Influence of membrane fluidity changes upon the imprinting of polypeptide hormones in Tetrahymena

Hormonal imprinting is a physiological phenomenon, in which after the first encounter the receptorial and functional responses of a cell change for future occasions. The present experiments demonstrate (using Tetrahymena as a model cell) that the imprinting is very sensitive to the changes in membrane physical state. Cultivation of Tetrahymena cells in 28 or 15 degrees C or in ergosterol-supplemented media caused only quantitative differences in the imprinting; however, the process of cooling (shift-down) or reheating (shift-up) resulted in a false reaction. The combined treatment by ergosterol and cooling completely abolished the imprinting. These results indicate that hormonal imprinting is a membrane-dependent process.