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A consecutive-2-out-of-n defining F system is modelled and analyzed for both node and sink failure. Failure probabilities of nodes and links are different as link failure depends on link length. Node O is the source and node n+1 is the sink. Only if k consecutive nodes fail can there be no source-to-sink path.

Oncogenic human papillomavirus (HPV) plays a possible aetiological role in a subset of head and neck cancers, particularly in tonsillar carcinomas. For establishing a model to study mechanisms involved in HPV-associated tonsillar carcinogenesis, normal human tonsillar epithelial (HTE) cells were transfected with full-length HPV-16 DNA. The transfections produced four immortalised cell lines, designated HTE-114/K1, HTE-114/K2, HTE-114/K3 and HTE-114/B. All transfected HTE cell lines were cytogenetically abnormal. They exhibited altered morphology and impaired expression of cytokeratins in organotypic cultures. They failed to form colonies in soft agarose and formed no tumours in nude mice within 6 months. Each of them contained integrated viral DNA in a distinctive pattern as shown by Southern blot hybridisation. Early viral transcripts containing the E7 gene were detected by northern blot hybridisation. In conclusion, primary HTE cells can be immortalised following transfection with full-length HPV-16 DNA; the immortalised cell lines had partially retained epithelial characteristics in their morphology and function. They seem to represent early stages of premalignant epithelial cells and thus provide a useful model for studying further the multistep molecular events of HPV-16-associated tonsillar carcinogenesis.

The aquatic fern Marsilea quadrifolia produces different types of leaves in response to changes in natural environment and culture conditions. When the conditions are in favor of producing the submerged-type leaves, exogenous application of the plant hormone abscisic acid (ABA) induces the formation of aerial-type leaves. Tissues responsive to ABA were localized to the shoot apical meristem and the associated organ primordia. From these tissues, at least two tiers of ABA-regulated early genes were identified, including seven primary genes and seventeen secondary genes. These genes, designated ABRH for ABA-responsive heterophylly, showed diverse expression patterns during the course of heterophyllous induction. Changes in the transcript level of ABRH genes started early, within 0.5-1.0 h after the addition of ABA to the culture medium. Some changes were transient while the others were persistent. The ABRHs contain extensive sequence homology to known genes, including those encoding transcription factors, protein kinases, membrane transporters, metabolic enzymes, structural proteins and those encoded by the chloroplast genome. Identification of these ABRHs is a first step toward the understanding of the regulation mechanisms of heterophylly, and the results suggest the involvement of novel metabolic and regulatory pathways in ABA-controlled morphogenesis.

A sensitive and reproducible real-time PCR assay based on TaqMan technology was developed for the detection and quantitation of hepatitis B virus (HBV) DNA in serum, and compared with an "in-house" qualitative PCR assay. HBV DNA was measured in 125 serum samples from 76 hepatitis B patients, consisting of 22 patients with an acute infection, 20 patients with a previous history of hepatitis B infection, and 34 patients with a chronic hepatitis B. Four patients with a chronic infection were treated with either an IFN-alpha monotherapy or a combination of IFN-alpha and lamivudine. Twenty-nine sera from healthy individuals and non-hepatitis B patients served as negative controls. The assay was validated by using a 10-fold dilution series of the World Virological Quality Control (VQC) sample containing 3.73 x 10(7) genome equivalents per ml. The detection limit for the real-time PCR was 3.73 x 10(2) genome equivalents per ml (geq/ml), while it was 3.73 x 10(3) geq/ml for the in-house PCR. The real-time PCR assay had an 8-logarithm dynamic range spanning from 10(2) to 10(10) geq/ml. In clinical serum samples, the real-time PCR and the in-house PCR detected HBV DNA in 81% (101/125) and 66% (83/125) of samples, respectively. HBV DNA was not detected among the negative controls by either of these assays. In conclusion, real-time PCR is a sensitive, specific, and a reproducible approach for the detection and quantitation of HBV DNA in clinical serum samples, useful also for monitoring the efficacy of antiviral treatment., (Copyright 2001 Wiley-Liss, Inc.)

The Arabidopsis genome contains at least 18 genes encoding members of the 70-kilodalton heat shock protein (Hsp70) family, 14 in the DnaK subfamily and 4 in the Hsp110/SSE subfamily. While the Hsp70s are highly conserved, a phylogenetic analysis including all members of this family in Arabidopsis and in yeast indicates the homology of Hsp70s in the subgroups, such as those predicted to localize in the same subcellular compartment and those similar to the mammalian Hsp110 and Grp170. Gene structure and genome organization suggest duplication in the origin of some genes. The Arabidopsis hsp70s exhibit distinct expression profiles; representative genes of the subgroups are expressed at relatively high levels during specific developmental stages and under thermal stress.

Prostaglandin A(1) (PGA1) reportedly inhibits NF-kappaB activation and induces expression of heat shock proteins. Since both these effects could be neuroprotective, the therapeutic potential of PGA1 in neurodegenerative disorders, where excitotoxicity may contribute to pathogenesis, was evaluated in rat striatal neurons exposed to the N-methyl-D-aspartate (NMDA) receptor agonist quinolinic acid (QA). Intrastriatal administration of PGA1 (5-80 nmol) attenuated QA (60 nmol)-induced internucleosomal DNA fragmentation. The inhibitory effects of a single dose of PGA1 (80 nmol) on QA (60 nmol)-induced DNA fragmentation were observed 12 to 48 h after treatment. PGA1 (80 nmol) also attenuated QA-induced DNA fragmentation when administered up to 4 h after QA exposure. PGA1 significantly decreased the loss of D1 dopamine receptors and GAD(67) mRNA in QA-injected striatum as measured by quantitative receptor autoradiography and in situ hybridization histochemistry, suggesting that it reduced the neuronal loss induced by QA. Protection of striatal neurons against QA-induced death by PGA1 was further indicated by Nissl staining 10 days after QA administration. PGA1 (5-80 nmol) significantly inhibited QA-induced NF-kappaB activation by blocking inhibitory kappaB-alpha degradation but had no effect on activator protein-1 binding activity. PGA1 (80 nmol) treatment substantially increased 70- and 72-kDa heat shock protein levels in striatum. These results indicate that PGA1 blunts NMDA receptor-mediated neuronal apoptosis by a mechanism possibly involving the up-regulation of neuroprotective heat shock proteins and inhibition of NF-kappaB activation. In view of its potent neuroprotective activity, PGA1 could prove useful in the treatment of certain neurodegenerative disorders related to excitotoxicity.

Peripheral blood lymphocytes from a single swine were stimulated with Concavadin A for 17 h, and the total RNA was isolated from it. Then, the mRNA specific for porcine IFN gamma was amplified by reverse transcription polymerase chain reaction. After sequencing, the IFN gamma gene has been successfully inserted into vector pJLA-503 and highly expressed in E. coli. Recombinant porcine IFN gamma expressed as inclusion body, which was dissolved in 7 mol/L guanidine chloride and subsequently renatured by dilution in refolding buffer containing 0.5 mol/L L-arginine. In order to obtain pure protein, the renatured IFN gamma was purified by the chromatographies of SP-Sepharose FF and Sephacryl S-200 HR. As a result, the final pure product can been seen as a single band in SDS-PAGE, and the cytokine activity was verified by inhibiting the cytopathic effect.

Objective: To analyse the immunostimulatory activity of CpG sequences in cysticercus cellulosae paramyosin (also named Antigen B, AgB) cDNA., Methods: C57BL/6 mice were immunized with pcDNA3-AgB plasmid, pcDNA3-AgB' (CpG sequences were mutated), pcDNA3 or AgB protein and two weeks later, immune response was assayed by ELISA., Results: IgG and IgG2a were detectable at week 2 after immunization and continually increased until week 4. The antibody levels elicited by pcDNA3-AgB were significantly higher(P < 0.05) than those elicited by others., Conclusion: After pcDNA3-AgB plasmid inoculation, the immune response of mouse was elicited not only by the AgB protein but also by the CpG immunostimulatory sequences in the AgB cDNA.

We have studied neurotoxicity induced by pharmacological concentrations of 3-hydroxykynurenine (3-HK), an endogenous toxin implicated in certain neurodegenerative diseases, in cerebellar granule cells, PC12 pheochromocytoma cells, and GT1-7 hypothalamic neurosecretory cells. In all three cell types, the toxicity was induced in a dose-dependent manner by 3-HK at high micromolar concentrations and had features characteristic of apoptosis, including chromatin condensation and internucleosomal DNA cleavage. In cerebellar granule cells, the 3-HK neurotoxicity was unaffected by xanthine oxidase inhibitors but markedly potentiated by superoxide dismutase and its hemelike mimetic, MnTBAP [manganese(III) tetrakis(benzoic acid)porphyrin chloride]. Catalase blocked 3-HK neurotoxicity in the absence and presence of superoxide dismutase or MnTBAP. The formation of H(2)O(2) was demonstrated in PC12 and GT1-7 cells treated with 3-HK, by measuring the increase in the fluorescent product, 2',7'-dichlorofluorescein. In both PC12 and cerebellar granule cells, inhibitors of the neutral amino acid transporter that mediates the uptake of 3-HK failed to block 3-HK toxicity. However, their toxicity was slightly potentiated by the iron chelator, deferoxamine. Taken together, our results suggest that neurotoxicity induced by pharmacological concentrations of 3-HK in these cell types is mediated primarily by H(2)O(2), which is formed most likely by auto-oxidation of 3-HK in extracellular compartments. 3-HK-induced death of PC12 and GT1-7 cells was protected by dantrolene, an inhibitor of calcium release from the endoplasmic reticulum. The protection by dantrolene was associated with a marked increase in the protein level of Bcl-2, a prominent antiapoptotic gene product. Moreover, overexpression of Bcl-2 in GT1-7 cells elicited by gene transfection suppressed 3-HK toxicity. Thus, dantrolene may elicit its neuroprotective effects by mechanisms involving up-regulation of the level and function of Bcl-2 protein.

Objective: To clone and express Cysticercus Cellulosae antigen cC1 in E. coli., Methods: cC1 cDNA fragment was cloned to BamHI and PstI sites of pGEM-3Z vector. After alteration of the restriction sites, the fragment was cloned to EcoRI and XhoI sites of pGEX-5T with a synthetic linker to construct recombinant expression vector pGEX-5T-cC1., Results: The clone produced the largest yield of cC1 protein expression when incubated in 2YT culture medium for 3 h or induced by IPTG for 6 h. Detected by scanning optical densitometry, cC1 constituted 57% of the total bacterial proteins. Western blotting analysis revealed that the GST-cC1 fusion protein exhibited a specific reactive band., Conclusion: High level expression of Cysticercus cellulosae antigen cC1 was obtained in E. coli.

We recently reported that cytosine arabinoside (AraC)-induced apoptosis of cerebellar neurons involves the overexpression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The present study was undertaken to investigate whether p53 and/or Bax overexpression participates in the AraC-induced apoptosis of cerebellar granule cells and, if so, the relationship between p53 induction and GAPDH overexpression in these cells. AraC-induced apoptosis of cerebellar granule cells was preceded by an increase in levels of p53 mRNA and protein detected between 1 and 8 hr after treatment. The mRNA level for a p53 target gene, Bax, was also increased. The increase in GAPDH mRNA lasted longer than that of either p53 or Bax, and the level of GAPDH protein in the particulate fraction increased after induction of GAPDH mRNA. The antisense oligonucleotide to p53 protected granule cells from AraC-induced chromatin condensation, internucleosomal cleavage, and apoptotic death. The inhibition of p53 expression by the p53 antisense oligonucleotide not only blocked the expression of Bax but also partially suppressed the increased GAPDH mRNA and protein levels. Conversely, the suppression of GAPDH expression and subsequent attenuation of apoptosis of granule cells by GAPDH antisense oligonucleotide did not influence the expression of p53 or Bax. Cerebellar granule cells prepared from p53 knock-out mice were resistant to AraC toxicity, and the p53 gene knock-out suppressed AraC-upregulated GAPDH expression. Moreover, infection of PC12 cells with an adenoviral vector containing p53 gene dramatically increased GAPDH expression and triggered cell apoptosis. These results suggest that AraC-induced apoptosis of cerebellar granule cells involves the expression of both GAPDH and p53 and that, similar to Bax, GAPDH is upregulated by p53 after exposure to the apoptotic insult.

Nuclear factor kappaB (NF-kappaB) appears to participate in the excitotoxin-induced apoptosis of striatal medium spiny neurons. To elucidate molecular mechanisms by which this transcription factor contributes to NMDA receptor-triggered apoptotic cascades in vivo, rats were given the NMDA receptor agonist quinolinic acid (QA) by intrastriatal infusion, and the role of NF-kappaB in the induction of apoptosis-related genes and gene products was evaluated. QA administration induced time-dependent NF-kappaB nuclear translocation. The nuclear NF-kappaB protein after QA treatment was comprised mainly of p65 and c-Rel subunits as detected by gel supershift assay. Levels of c-Myc and p53 mRNA and protein were markedly increased at the time of QA-induced NF-kappaB nuclear translocation. Immunohistochemical analysis showed that c-Myc and p53 induction occurred in the excitotoxin-sensitive medium-sized striatal neurons. NF-kappaB nuclear translocation was blocked in a dose-dependent manner by the cell-permeable recombinant peptide NF-kappaB SN50, but not by the NF-kappaB SN50 control peptide. NF-kappaB SN50 significantly inhibited the QA-induced elevation in levels of c-Myc and p53 mRNA and protein. Pretreatment or posttreatment with NF-kappaB SN50, but not the control peptide, also substantially reduced the intensity of QA-induced internucleosomal DNA fragmentation. The results suggest that NF-kappaB may promote an apoptotic response in striatal medium-sized neurons to excitotoxic insult through upregulation of c-Myc and p53. This study also provides evidence indicating an unique signaling pathway from the cytoplasm to the nucleus, which regulates p53 and c-Myc levels in these neurons during apoptosis.

Treatment with cytosine beta-D-arabinoside (AraC; 300 microM) induced a time-dependent accumulation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein in nuclei purified from cultured cerebellar granule cells, with a concomitant degradation of lamin B1, a nuclear membrane protein and a substrate of CPP32/caspase-3. Moreover, Asp-Glu-Val-Asp-fluoromethyl ketone (DEVD-fmk), a CPP32-selective antagonist, dose-dependently suppressed AraC-induced apoptosis of these neurons. Nuclear accumulation of GAPDH protein was associated with a progressive decrease in the activity of uracil-DNA glycosylase (UDG), one of the nuclear functions of GAPDH. The nuclear dehydrogenase activity of GAPDH was initially increased after treatment and then decreased parallel to UDG activity. Six GAPDH isoforms were detected in the nuclei of AraC-treated cells. The more alkaline isoforms, 1-3, constituted the bulk of the nuclear GAPDH, and the remaining isoforms, 4-6, were the minor species. Levels of all six isoforms were increased after treatment with AraC for 16 h; a 4-h treatment increased levels of only isoforms 4 and 5. Thus, it appears that various GAPDH isoforms are differentially regulated and may have distinct apoptotic roles. Pretreatment with GAPDH antisense oligonucleotide blocked the nuclear translocation of GAPDH isoforms, and the latter process occurred concurrently with a decrease in cytosolic GAPDH isoforms. Sodium nitroprusside-induced NAD labeling of nuclear GAPDH showed a 60% loss of GAPDH labeling after AraC treatment, suggesting that the active site of GAPDH may be covalently modified, denatured, or improperly folded. The unfolded protein response elicited by denatured GAPDH may contribute to AraC-induced neuronal death.

In this paper, the children, who had undergone the operation with the approach similar to that of Tetralogy Fallot, were selected and divided into 4 groups, according to different kinds of cardioplegia were infused during corrective operation. St. Thomas group (CC group) 24 cases, cold blood cardioplegia group (CBC group) 21 cases, terminal warm blood cardioplegia group (TWBC group) 12 cases, and continuous warm blood cardioplegia group (CWBC group) 12 cases. Through the measurement of left ventricular contraction pressure and CK-Mb release in the postoperative period, the effect of myocardial preservation was better in TWBC and CWBC groups than in CC and CBC groups (P < 0.05), ATP volume of myocardium in TWBC and CWBC groups were higher (17.1 and 18.2 mumol/g) than that in CBC group (2.48 mumol/g) (P < 0.01) CP values were respectively 8.74 mumol/g, 7.63 mumol/g and 5.5 mumol/g (P < 0.05). 9 cases (37%) in CC group needed inotropic drug to assist circulation postoperation, 4 cases (16%) in CBC group, 2 cases (12%) in both TWBC and CWBC group. The results demonstrated that WBC had a better myocardial protection effect.

The present paper has shown the effects of myocardial protection of isolated rat heart which were infused with different kinds of cardioplegia, and made to be arrested in the state of ischemia and absence of oxygen for 120 min. The heart rate, left ventricular constraction pressure and cardiac output volume, the myocardium water content and calcium content and pathological examination of myocardium were observed. The isolated rabbit heart under the circumstances of ischemia and absence of oxygen at 37 degrees C for 20 min Observations of the different kinds of cardioplegia. was observed that the different pH and oxygen content between artery and vein of the heart during the infusion of cardioplegia, the value of left ventricular constraction pressure multiplied by heart rates after reperfusion with autologous artery blood for 20 min. The values of CPK and MDA in right atrial blood, the ATP and CP volume of myocardium and pathologic study of myocardium were carried out. The results demonstrated that the warm blood cardioplegia had a better myocardial protection effect in supplying sufficient oxygen to myocardium during heart arrest, preserving and increasing energy store; controlling reperfusion in jury after ischemia, buffering acidosis and preserving heart status function. Therefore it has great value for improving the safety of the patients with complex and high risk heart diseases in perioperation.

The authors tailored a 26-item risk assessment tool (RAT) for falls based on a literature review and an analysis of causative factors of falls that had occurred over a 3-month period at the Olin E. Teague VA Medical Center, an 1,100-bed acute medical-surgical, psychiatric, and extended care facility in Temple, TX. The RAT was completed by nursing staff on 10 patient units (four medical, four surgical, and two nursing home units) for all admissions during the period. A 25% sample of the completed RATs was randomly selected (n = 208). Pearson's correlation coefficient was used to identify factors that would most likely predict falls from the RATs of the randomly selected group and of the patients who fell (n = 78). Only 4 of the 26 items were statistically related to falls. Based on findings from this study, the RAT was shortened to the four items and called the RISK (Reassessment Is Safe "Kare") tool.

A 30,000 molecular weight testicular Cd-binding peak (30,000 MW Cd-BP) previously implicated in Cd-induced testicular injury was unstable during storage with respect to apparent molecular weight determined by Sephadex G-75 chromatography. Storage of testicular cytosol labeled with 109Cd in vivo or in vitro for several days at 4 degrees C under nitrogen resulted in disappearance of the 30,000 MW Cd-BP and increased 109Cd uptake in other protein fractions. Rechromatography of the previously isolated 30,000 MW Cd-BP after storage gave rise to a 109Cd peak eluting in the higher molecular weight region. The latter effect was prevented by 1 mM dithiothreitol, suggesting that sulfhydryl groups were involved in the apparent aggregation. The 30,000 MW Cd-BP found in testes of rats was not present in testes of roosters, nor in liver and kidney of either species, providing further evidence of a correlation between the occurrence of 30,000 MW Cd-BP protein in the tissue and susceptibility to Cd-injury. The inability of parenterally administered HgCl2 to induce testicular injury compared to the same dose of CdCl2(0.011 mmol/kg) is apparently related to the poor uptake of Hg in the testes (one-eighteenth that of Cd) rather than to an inability of Hg to bind to the 30,000 MW Cd-BP. Our studies indicate that binding of Cd to this unique 30,000 MW testicular component, as yet unidentified, is a possible basis for the unique sensitivity of the testis to Cd injury.

The effect of dietary selenite on the binding characteristics of serum proteins was investigated with rats. In the control serum, the maximal binding of phenylmercuric acetate (PMA) and methylmercuric chloride (MMC) to rat serum protein was approx. 18 and 9 nmoles per mg protein, respectively. The binding of Hg2+ was biphasic and it did not reach a maximum at the concentrations used. Selenite treatment caused a reduction in binding capacity of serum proteins to Hg2+ and PMA, and an increase in the binding affinities. However, there were no such changes for the binding of MMC. Selenite protection from mercury toxicity, therefore, acts not only via a change in tissue distribution and a change in the formation of seleno-proteins but, also, via a change in the binding characteristics to some mercury compounds. In the case of methylmercury, a different mechanism of protection must exist as the modification of tissue distribution, its binding to subcellular and soluble proteins and the binding characteristics remained equivocal.