Structure of the O-specific polysaccharide of Mesorhizobium huakuii IFO15243T

The structure of the O-specific polysaccharide isolated by mild acid hydrolysis of the lipopolysaccharide of Mesorhizobium huakuii IFO15243T was studied using methylation analysis and various one- and two-dimensional 1H and 13C NMR experiments. The O-antigen polysaccharide was found to be linear polymer constituted by a trisaccharide repeating unit of the following structure: --> 2)-alpha-L-6dTalp-(1 --> 3)-alpha-L-6dTalp-(1 --> 2)-alpha-L-Rhap-(1 -->.     

Some oncogene and tumour suppressor gene protein products expression in B-cell chronic lymphocytic leukaemia

The expression of Bcl-2, P53 proteins and known markers of proliferation, namely proliferating cell nuclear antigen (PCNA) and Ki67, in 29 patients with B-cell chronic lymphocytic leukaemia (B-CLL) was investigated. All leukaemic patients were classified, and immunophenotyped by the two-colour immunofluorescence method with the use of fluorocytometry. B-CLL was heterogeneous in the range of biological parameters of tumour cells. B-CLL patients manifested 34% positive Ki67 and 61% PCNA expression, whereas Bcl-2 and P53 positivity was 81% and 42%, respectively. The level of intracellular expression of Bcl-2 and P53 proteins did not depend on the stage of disease estimated by routine methods. Ki67 and PCNA expression was significantly higher in B-CLL patients with more advanced stages of the disease. A statistically significant correlation was established between their mutual expression.     

Heme synthesis in yeast does not require oxygen as an obligatory electron acceptor

In a previous paper (Krawiec, Z., Biliński, T., Schüller, C. & Ruis, H., 2000, Acta Biochim. Polon. 47, 201-207) we have shown that catalase T holoenzyme is synthesized in the absence of oxygen after treatment of anaerobic yeast cultures with 0.3 M. NaCl, or during heat shock. This finding suggests that heme moiety of the enzyme can either be formed de novo in the absence of oxygen, or derives from the preexisting heme pool present in cells used as inoculum. The strain bearing hem1 mutation, resulting in inability to form delta-aminolevulinate (ALA), the first committed precursor of heme, was used in order to form heme-depleted cells used as inocula. The cultures were supplemented with ALA at the end of anaerobic growth prior the stress treatment. The appearance of active catalase T in the stressed cells strongly suggests that heme moiety of catalase T is formed in the absence of oxygen. This finding suggests the necessity to reconsider current opinions concerning mechanisms of heme synthesis and the role of heme as an oxygen sensor.     

Arterial ketone index in assessing liver function and its detoxicative capability after ischemia-reperfusion injury

Arterial ketone index (AKBR) which is the ratio of acetoacetic acid to 3-hydroxybutyric acid in the arterial blood, is believed to reflect the mitochondrial reduction potential of hepatocytes and general energy state of the liver. In the presented paper we challenged this hypothesis by analysing the correlation between AKBR and the results of typical liver blood tests (AspAT, AlAT, LDH, CRP) and biotransforming potential of the liver (cytochromes P450, b5 and their corresponding NADPH and NADH reductases) in the model of ischemia-reperfusion injury of rat liver. The results were compared with histochemical analysis of distribution and activity of SDH, LDH and G-6-Pase, the key marker enzymes of the liver. We have shown that, except in the case of acute phase protein (CRP), a decrease in AKBR correlated well with the increase of the level of indicator enzymes in serum. Histochemical analysis also confirmed that AKBR correlates with the degree of damage to hepatocytes during early stage of reperfusion after 60 min of liver ischemia. In the Spearman test, AKBR was significantly correlated with the changes in cytochrome P450 content and its NADPH reductase activity which indicates a high sensitivity of this test. We conclude that the decrease of AKBR value reflects the impairment of basic energy pathways and detoxicative capability of the liver.     

The response of L5178Y lymphoma sublines to oxidative stress: antioxidant defence, iron content and nuclear translocation of the p65 subunit of NF-kappaB

We examined the response to hydrogen peroxide of two L5178Y (LY) sublines which are inversely cross-sensitive to hydrogen peroxide and X-rays: LY-R cells are radio-resistant and hydrogen peroxide-sensitive, whereas LY-S cells are radiosensitive and hydrogen peroxide-resistant. Higher initial DNA breaks and higher iron content (potentially active in the Fenton reaction) were found in the hydrogen peroxide sensitive LY-R cells than in the hydrogen peroxide resistant LY-S cells, whereas the antioxidant defence of LY-R cells was weaker. In particular, catalase activity is twofold higher in LY-S than in LY-R cells. The content of monobromobimane-reactive thiols is 54% higher in LY-S than in LY-R cells. In contrast, the activity of glutathione peroxidase (GPx) is about two times higher in LY-R than in LY-S cells; however, upon induction with selenium the activity increases 15.6-fold in LY-R cells and 50.3-fold in LY-S cells. Altogether, the sensitivity difference is related to the iron content, the amount of the initial DNA damage, as well as to the efficiency of the antioxidant defence system. Differential nuclear translocation of p65-NF-kappaB in LY sublines is due to the more efficient antioxidant defence in LY-S than in LY-R cells.     

The effect of selected factors on the course of wound healing after surgery for laryngeal neoplasms

Finding of the a etiologic factors and participation of bacteria flora in wound healing in laryngeal cancer treatment was the purpose of our study. Investigations were performed in 27 patients. Swabs were taken from the postoperative wounds. Detailed identifications of the bacteria flora and antibiotic susceptibility of bacteria were performed. Wound healing was estimated according to extension of the carcinoma, applied antibiotics, state of the oral cavity, the kind of bacteriological flora isolated after surgical treatment from postoperative wounds. It was found that wound healing depended on the extension of carcinoma, as well as, type of isolated bacteria and antibiotic therapy used. The proper healing of postoperative wounds was not dependent on the state of the oral cavity and the dentition. The main cause of postoperative complication of wounds was methicillin-resistant Staphylococcus aureus (MRSA).     

Sesquiterpenoids and phenolics from Crepis mollis

From the roots of Crepis mollis, one new and two known guaianolides were isolated together with eight known guaianolide glycosides, one known germacranolide glycoside and two known phenylpropanoids. The structure and relative configuration of the new compound were established as 9alpha-hydroxy-4beta, 15, 11beta, 13-tetrahydro-dehydrozaluzanin C by spectral methods.     

Connexin43 in porcine myocardium and non-pregnant myometrium

It is generally accepted that connexin43 (Cx43) is a major constituent of heart and myometrial gap junctions. However, the presence of Cx43 gap junctions in non-pregnant myometrium is still poorly documented. Tissue sections of porcine heart and non-pregnant uterus and myometrial smooth muscle cell cultures were immunostained with monoclonal antibody against Cx43. In the heart, intensive immunostaining was confined to the intercalated discs as previously reported. In the non-pregnant uterus, punctuate immunostaining of Cx43 was seen throughout the myometrium along cell interfaces between myocytes. The expression of Cx43 was sustained in cultured smooth muscle cells isolated from non-pregnant myometrium. Western blotting has detected single isoform of Cx43 in both, cardiac and myometrial tissues. The electrophoretic mobility of porcine heart Cx43 was similar to that of myometrial isoform but different from the pattern of mobility of Cx43 of the rat heart. Hence, porcine myometrium may provide attractive model for studying cellular mechanisms triggering expression of gap junction protein in normal (non-pregnant) uterus.     

Lack of effects of glycineB receptor ligands on the psychostimulant-induced discriminative stimuli in rats

To examine the role of glycineB receptors in the stimulus effects induced by psychostimulants, separate groups of rats were trained to discriminate amphetamine (AMPH; 1 mg/kg) from saline (SAL), or cocaine (COC; 10 mg/kg) from SAL, using a two-lever operant procedure. Substitution studies showed that neither 1-aminocyclopropanecarboxylic acid (ACPC; 200 mg/kg) nor 7-chloro-4-hydroxy-3-(3-phenoxy)phenyl-(H)quinolone (L-701,324; 3 mg/kg), being a partial agonist or an antagonist at glycineB receptors, respectively, generalized for the training drugs. Combination tests of glycineB ligands demonstrated that injection of a fixed dose of ACPC (200 mg/kg) or L-701,324 (3 mg/kg) together with different doses of AMPH or COC practically did not modify dose-response curves of the psychostimulants, nor did it affect their ED50 values. Our results indicate that glycineB receptors do not play a role in the discriminative effects of AMPH and COC.