Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity

The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.     

Inhibition of interferon secretion by vinblastine

The plant alkaloids vinblastine and colchicine are known to arrest cells in mitosis by virtue of their binding to spindle protein. These drugs are also capable of binding to microtubule protein and causing these structures to disaggregate into nonfunctional subunits (1, 2). Microtubular structures are thought to be involved in the secretory process of a number of proteins including insulin (7), collagen (4), and thyroid hormone (12). In this report we present our findings on the effects of these two drugs on the synthesis and secretion of interferon in a high producing human foreskin fibroblast strain (FS-4) (11).     

Change in the temperature preferences of <Emphasis Type="Italic">Beauveria bassiana sensu lato</Emphasis> isolates in the latitude gradient of Siberia and Kazakhstan

The radial growth of twenty isolates of the entomopathogenic fungus Beauveria bassiana sensu lato from different natural zones of Western Siberia and Kazakhstan (from 65 to 43°N) was tested under different temperatures (5–35°C). It was shown that the thermotolerance of the fungal isolates increased significantly from the north to south. The cold activity of the cultures did not significantly correlate with the latitude of origin and the sum positive temperatures of the regions. A distinct group of the steppe thermotolerance isolates was shown by the analysis of genomic polymorphism using seven intermicrosatellite DNA markers (ISSR). The steppe isolates had high levels of virulence to the wax moth Galleria mellonella and the Colorado potato beetle Leptinotarsa decemlineata at high temperatures (>30°C) compared to that of the forest-steppe isolates. The obtained data indicate that the use of isolates from the steppe zone will be most promising for the insect pest control under the conditions of continental and arid climate.     

Influence of a natural and a synthetic inhibitor of factor XIIIa on fibrin clot rheology

We investigated the origins of greater clot rigidity associated with FXIIIa-dependent cross-linking. Fibrin clots were examined in which cross-linking was controlled through the use of two inhibitors: a highly specific active-center-directed synthetic inhibitor of FXIIIa, 1,3-dimethyl-4,5-diphenyl-2[2(oxopropyl)thio]imidazolium trifluoromethylsulfonate, and a patient-derived immunoglobulin directed mainly against the thrombin-activated catalytic A subunits of thrombin-activated FXIII. Cross-linked fibrin chains were identified and quantified by one- and two-dimensional gel electrophoresis and immunostaining with antibodies specific for the alpha- and gamma-chains of fibrin. Gamma-dimers, gamma-multimers, alpha(n)-polymers, and alpha(p)gamma(q)-hybrids were detected. The synthetic inhibitor was highly effective in preventing the production of all cross-linked species. In contrast, the autoimmune antibody of the patient caused primarily an inhibition of alpha-chain cross-linking. Clot rigidities (storage moduli, G') were measured with a cone and plate rheometer and correlated with the distributions of the various cross-linked species found in the clots. Our findings indicate that the FXIIIa-induced dimeric cross-linking of gamma-chains by itself is not sufficient to stiffen the fibrin networks. Instead, the augmentation of clot rigidity was more strongly correlated with the formation of gamma-multimers, alpha(n)-polymers, and alpha(p)gamma(q)-hybrid cross-links. A mechanism is proposed to explain how these cross-linked species may enhance clot rigidity.     

The phylogenetic potential of entire 26S rDNA sequences in plants

18S ribosomal RNA genes are the most widely used nuclear sequences for phylogeny reconstruction at higher taxonomic levels in plants. However, due to a conservative rate of evolution, 18S rDNA alone sometimes provides too few phylogenetically informative characters to resolve relationships adequately. Previous studies using partial sequences have suggested the potential of 26S or large-subunit (LSU) rDNA for phylogeny retrieval at taxonomic levels comparable to those investigated with 18S rDNA. Here we explore the patterns of molecular evolution of entire 26S rDNA sequences and their impact on phylogeny retrieval. We present a protocol for PCR amplification and sequencing of entire (approximately 3.4 kb) 26S rDNA sequences as single amplicons, as well as primers that can be used for amplification and sequencing. These primers proved useful in angiosperms and Gnetales and likely have broader applicability. With these protocols and primers, entire 26S rDNA sequences were generated for a diverse array of 15 seed plants, including basal eudicots, monocots, and higher eudicots, plus two representatives of Gnetales. Comparisons of sequence dissimilarity indicate that expansion segments (or divergence domains) evolve 6.4 to 10.2 times as fast as conserved core regions of 26S rDNA sequences in plants. Additional comparisons indicate that 26S rDNA evolves 1.6 to 2.2 times as fast as and provides 3.3 times as many phylogenetically informative characters as 18S rDNA; compared to the chloroplast gene rbcL, 26S rDNA evolves at 0.44 to 1.0 times its rate and provides 2.0 times as many phylogenetically informative characters. Expansion segment sequences analyzed here evolve 1.2 to 3.0 times faster than rbcL, providing 1.5 times the number of informative characters. Plant expansion segments have a pattern of evolution distinct from that found in animals, exhibiting less cryptic sequence simplicity, a lower frequency of insertion and deletion, and greater phylogenetic potential.