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.     

Tentative determination of the molecular weight of substances stimulating the flowering of winter wheat

Murashige & Skoog nutrient was supplemented with substances of molecular weight (M_W) less than 5 kDa, which were separated from extract of winter wheat ears by means of Sephadex G-25 ultrafiltration. Isolated embryos of the same wheat cultivar (Grana) were vernalized in the nutrient for 0 and 7 days at 2 °C for 2 weeks and planted in a glass-house. After 150 days of growth (20/17 °C day/night) the development of the shoot apices was observed. It was found that substances of M_W<5 kDa strongly stimulated the generative development of the plants, enabling the earing of 30 % of non-vernalized plants (control=0%) and 100 % plants vernalized for 7 days (control=29 %). The substances present in the extract of both spring (cv. Jara) and winter (cv. Grana) varieties were fractionated by means of Sephadex chromatography into 300 fractions of M_W=1 to 5 kDa and each of them was added to the isolated embryos of cv. Grana. The embryos were vernalized at 2 °C for 7 days and then cultured as previously described. It was found that the differentiation of the shoot apices was stimulated by over 34 % by fractions of winter wheat extract and more than 50 % by fractions of the spring wheat extract. However, only a few of identical fractions of the extracts of both wheat varieties were able to induce the earing of the plants. These fractions were grouped in 4 continuous intervals of M_W equal to about 4.5–4.9, 3.2–3.3, 2.1–2.6 and 1.00–1.03 kDa. Within the three intervals was identified a small group of identical fractions, which affected the growth of the seedlings in similar mode i.e. inhibiting or stimulating. Thus it can be assumed that these intervals contained identical or similar substances capable of stimulating strongly the earing of winter wheat.     

Effect of a short-term dietary creatine supplementation on high-energy phosphates in the rat myocardium.

The aim of this study was to find out whether creatine (Cr) feeding affects total creatine (TCr), phosphocreatine (PCr), adenine nucleotide contents and beta-hydroxy-acyl-CoA-dehydrogenase (HAD) activity in myocardium as compared to red skeletal muscle. Ten adult Wistar rats received Cr (2.5% of diet weight) for 7 days. In Cr fed rats, PCr was increased (by approx. 20%) in cardiac and in soleus muscles with ATP elevated in myocardium and TCr and free Cr in soleus. In both muscles, Cr feeding enhanced HAD activity. It is concluded, that dietary Cr does increase cardiac muscle high energy phosphate reserves and its oxidative potential.