Neurofilament Protein Phosphorylation in Spinal Cord of Experimentally Diabetic Rats

This study was designed to determine if the known decrease in slow axonal transport of proteins in the sciatic nerve of experimentally diabetic rats is related to altered phosphorylation of neurofilament proteins (NFPs). Rats were rendered diabetic with 50 mg/kg of streptozotocin, i.p. At 3 and 6 weeks later, NFPs were prepared from spinal cord. The in vivo phosphorylation state of NFPs was examined by using phosphate-dependent (RT97) and -independent (RMd09) antibodies against high-molecular-mass NFPs on Western blots. Neurofilament-associated kinase activity was also measured in vitro by incubation of NFPs with [32P]ATP. Phosphorylation of all three NFPs (high, medium, and low molecular mass) occurred, as confirmed by gel electrophoresis and autoradiography. At 30 min of incubation, protein-bound radioactivity in NFPs from diabetic animals was reduced to 86.7 +/- 3.4 and 54.3 +/- 19.6% of that in nondiabetic animals at 3 and 6 weeks of diabetes, respectively (p less than 0.001 and p less than 0.05, respectively). NFPs were also incubated with acid phosphatase and rephosphorylated. Results showed that the increased in vivo phosphorylation contributed to the decreased in vitro phosphorylation. Extraction of protein kinases and addition back to the NFPs revealed, in addition, a reduced activity in the diabetic animals of the protein kinases measured in vitro.     

Differential expression of genes participating in cardiomyocyte electrophysiological remodeling via membrane ionic mechanisms and Ca2+-handling in human heart failure

Molecular and Cellular Biochemistry - Excitation–contraction coupling in normal cardiac function is performed with well balanced and coordinated functioning but with complex dynamic...     

Idiotype stimulation of T lymphocytes from Trypanosoma cruzi-infected patients

Anti-Trypanosoma cruzi epimastigote antibodies (anti-epi) from pooled and individual sera from patients with chronic Chagas' disease were purified on immunoaffinity columns of epimastigotes antigens (epi) coupled to activated Sepharose 4B. SDS-PAGE analysis of purified anti-epi preparations showed only the presence of human IgG H and L chains. These antibodies preparations showed similar Western blotting profiles as the sera pools from which they originated. The main polypeptides recognized by anti-epi had apparent molecular masses 31, 46, 51, 75 and 85 kDa. No difference in these patterns were detected between anti-epi from pooled sera of cardiac (anti-epiC) and indeterminate (anti-epiI) clinical forms. Anti-epi preparations (20 to 60 micrograms/ml) of pooled and individual sera stimulated proliferation of homologous and autologous PBMN or T-lymphocyte-enriched population. The stimulatory ability was dependent upon the PBMN-anti-epi combinations. There is no direct correlation between the level of PBMN response to epi and anti-epi stimuli. Comparison of the stimulatory activities of anti-epiC vs anti-epiI on PBMN of either cardiac or indeterminate group of patients indicate that anti-epiC is significantly more active than anti-epiI (p less than 0.025). These data demonstrate the presence of auto-anti-idiotypic-T cells in chagasic patients and lead to the possibility that idiotype/anti-idiotype interactions may play a role in determining the pathogenesis of chagasic cardiopathy.     

Inhibition of the formation of lipid-linked intermediates in normal and transformed cells by a purified tunicamycin homologue

Summary The deffects of a purified homologue of tunicamycin (B₂-tunicamycin) on the biosynthesis of lipid-linked intermediates participating in protein glycosylation in normal embryonic fibroblasts, 3T3 and virally transformed (simian virus 40 and polyoma virus) mouse fibroblasts grown in culture were investigated. Long incubations (20 h) with the antibiotic caused a higher degree of inhibition of sugar incorporation into glycoproteins in transformed cells. However, the formation of lipid-linked intermediates was inhibited to a similar level in both cell types. When time dependent inhibition experiments were carried out using transformed cells, an earlier and stronger inhibition of the formation of lipid-oligosaccharides occurred (70% inhibition at 30 min). In 3T3 cells, prolonged incubation (6–8 h) was necessary in order to reach a similar degree of inhibition. Formation of lipid-sugar was also inhibited to a greater extent by B₂-tunicamycin in transformed cells. This inhibition was not clearly time dependent. Analysis of the newly synthesized glycolipids in 3T3 and in transformed cells after B₂-tunicamycin treatment have shown reduction in dolichyl-P-P-sugars as well as in other glycolipids. Dimethylsulfoxide (10%) and linoleic acid (0.5 mg/ml) markedly increased the level of tunicamycin activity in 3T3 cells while phosphatidylcholine (2 mg/ml) partially reversed it. The stronger and faster inhibition of the formation of lipid intermediates of the dolichyl-phosphate cycle caused by B₂-tunicamycin in transformed cells, described here for the first time, may therefore be due to differences in penetration of the antibiotic into these cells.Abbreviations DMEM Dulbecco's modified Eagle's medium - DMSO dimethylsulfoxide - MF mouse fibroblasts from Balb/c mouse embryos - 3T3 Balb/3T3 mouse fibroblastic line - SV40 Simian virus 40 - PY polyoma virus - TLC thin layer chromatography     

Validation of the cumulative or replicate NAA method for the determination of trace elements in biological materials

Biological Trace Element Research - To make the best use of time and facilities, a neutron activation system, fully automatic, including spectrum and data processing, to be used with short-lived...     

盐磷胁迫对木麻黄和台湾相思种子萌发及幼苗生长的影响

恶劣环境下,人工海防林因面临养分胁迫而经营困难。为探讨盐、磷胁迫对主要海防林树种木麻黄和台湾相思种子萌发及生长的影响,该研究分别用不同浓度的NaCl(盐)和KH₂PO₄(磷)溶液处理种子和浇灌幼苗,测定种子萌发和幼苗生长指标。结果表明：(1)高盐胁迫显著抑制种子萌发,对幼苗生长有一定影响,但两种植物影响程度不同;台湾相思种子萌发耐盐性高于木麻黄,前者相对盐害率最大值为23.03%,后者为89.15%;随着盐浓度增加,木麻黄和台湾相思种子的发芽率、发芽势、发芽指数和活力指数均降低,对应最大值分别为38.70%、34.67%、18.70、0.055和76.67%、62.22%、48.46、6.11。(2)两种植物的株高和根长随盐浓度增加而降低,木麻黄和台湾相思株高分别为12.29～6.01 mm和48.27～17.33 mm,根长分别为8.57～1.45 mm和33.41～5.88 mm;台湾相思根、茎、叶生物量及根冠比均随盐浓度的增加逐渐减小,木麻黄各处理差异较小。(3)台湾相思的种子和幼苗较木麻黄更耐低磷环境,二者最适磷浓度存在差异;木麻黄种...     

Utilization of Response Surface Methodology in Optimization of Proline Extraction from Castanea sativa Honey

Proline constitutes approximately 85 % of the amino acid composition of honey. Therefore, the quantitative determination of this amino acid in honey samples is used by many national/international authorities to evaluate the quality of honey types. In this study, it was aimed to achieve maximum proline amino acid extraction from honey samples whose botanical origins were confirmed by melissopalynological analysis. For this reason, based on three different spectrophotometric methods used in the literature for proline analysis, proline extraction was optimized with the Response Surface Method (RSM) and Box-Behnken experimental design. Three independent variables were determined as treatment time (2, 6, and 10 min), treatment temperature (22, 46, and 70 °C), and cooling time (5, 25, and 45 min). As a result of the optimization, it was seen that only significantly effective independent variable on the proline content of honey was the processing temperature. The optimum conditions obtained as a result of the RSM were found to be 2 min for the treatment time, 70 °C for the treatment temperature and 45 min for the cooling time. The composite desirability of the optimum conditions (R²) was found to be 1.00. It was determined that the method proposed by International Honey Commission (IHC) is efficient for proline analysis, but it provides more proline extraction by reducing of time from 10 min to 2 min in hold time in boiling water bath only during the extraction step. As a result, the conditions to be used in order to achieve maximum proline extraction with different spectrophotometric methods were determined and optimum values were determined. In addition, since the botanical origin of honey samples significantly affects the proline content of honey, it can be suggested that this study be optimized for different monofloral honey samples as well.     

Propolis Enhances 5-Fluorouracil Mediated Antitumor Efficacy and Reduces Side Effects in Colorectal Cancer: An in Vitro and in Vivo Study

In this study, we investigated the combined treatment of 5-fluorouracil (5-FU) and Anatolian propolis extract (PE) on colorectal cancer (CRC)using in vitro and in vivo studies. We exposed luciferase-transfected (Lovo-Luc CRC) cells and healthy colon cells (CCD-18Co) to varying concentrations of 5-FU and PE to assess their genotoxic, apoptotic, and cytotoxic effects, as well as their intracellular reactive oxygen species (iROS) levels. We also developed a xenograft model in nude mice and evaluated the anti-tumor effects of PE and 5-FU using various methods. Our findings showed that the combination of PE and 5-FU had selectivity against cancer cells, particularly at higher doses, and enhanced the anti-tumor effectiveness of 5-FU against colon CRC. The results suggest that PE can reduce side effects and increase the effectiveness of 5-FU through iROS generation in a dose-dependent manner.     

High-resolution autoradiography of nuclear modifications during and after heat treatment ofNeurospora crassa

Summary The appearance of perinucleolar electron-dense spots in the nuclei of macroconidia ofNeurospora crassa incubated at 46C and their disaggregation after shift-down to 25 C have been investigated by high-resolution autoradiography after (5-³H) uridine pulses with or without chase periods. The RNA of these ribonucleoprotein-rich dense spots has been found to originate mainly from the heatsensitive nucleolus; after return to 25 C, the nucleolar activity was recovered and the RNA material stored either in an unprocessed or a mature rRNA form in the dense spots was found to be progressively extruded into the cytoplasm.