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H Zhang

Publications and source records attributed to H Zhang.

At least 361 records · Page 20Linked to original sources
PubMed2001

Specific amino acid deficiency alters the expression of genes in human melanoma and other tumor cell lines.

This study determined the effect of tyrosine (Tyr) and phenylalanine (Phe) deprivation on protein expression and phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4)/stress-activated protein/Erk kinase (SEK1), a metastasis suppressor gene. Differential display and suppressive subtractive hybridization techniques identified genes modulated by Tyr and Phe deprivation. Expression of MKK4/SEK1 protein varied widely among human A375, A375SM and SB2 melanoma, PC-3 and DU145 prostate cancer, and MDA-MB-231 breast cancer cell lines and within the different lines. Phosphorylation of the MKK4/SEK1 protein similarly varied. No differences in MKK4/SEK1 gene expression or in the 41 other metastasis and tumor suppressor genes were found in A375 melanoma cells cultured in Tyr- and Phe-deprived media. A number of up-regulated and down-regulated genes in A375 melanoma cells were identified by differential display and suppressive subtractive hybridization that were pertinent to regulation of cytoskeletal organization, cell movement, gene transcription and metastasis. Two tumor marker genes, the gene for enolase and FUS/CHOP, were down-regulated by Tyr and Phe deprivation. This study shows that tumor cells display heterogeneity in their response to deprivation of Tyr and Phe and that these amino acids may be signaling molecules that regulate gene expression and function in tumor cells.

Blotting, Western↗
PubMed2001

Carotenoids affect proliferation of human prostate cancer cells.

We investigated whether various carotenoids present in foodstuffs were potentially involved in cancer-preventing action on human prostate cancer. The effects of 15 kinds of carotenoids on the viability of three lines of human prostate cancer cells, PC-3, DU 145 and LNCaP, were evaluated. When the prostate cancer cells were cultured in a carotenoid-supplemented medium for 72 h at 20 micromol/L, 5,6-monoepoxy carotenoids, namely, neoxanthin from spinach and fucoxanthin from brown algae, significantly reduced cell viability to 10.9 and 14.9% for PC-3, 15.0 and 5.0% for DU 145, and nearly zero and 9.8% for LNCaP, respectively. Acyclic carotenoids such as phytofluene, zeta-carotene and lycopene, all of which are present in tomato, also significantly reduced cell viability. On the other hand, phytoene, canthaxanthin, beta-cryptoxanthin and zeaxanthin did not affect the growth of the prostate cancer cells. DNA fragmentation of nuclei in neoxanthin- and fucoxanthin-treated cells was detected by in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. Neoxanthin and fucoxanthin were found to reduce cell viability through apoptosis induction in the human prostate cancer cells. These results suggest that ingestion of leafy green vegetables and edible brown algae rich in neoxanthin and fucoxanthin might have the potential to reduce the risk of prostate cancer.

Carotenoids↗
PubMed2001

Bradyrhizobium japonicum mutants with enhanced sensitivity to genistein resulting in altered nod gene regulation.

Bradyrhizobium japonicum mutants with altered nod gene induction characteristics were isolated by screening mutants for genistein-independent nod gene expression. Plasmid pZB32, carrying a nodY::lacZ transcriptional gene fusion, was introduced into B. japonicum cells that had been subjected to UV mutagenesis. Ten independent transformants producing a blue color on plates containing 5bromo-4chloro-3indolyl-beta-D-galactopyranoside but lacking genistein, indicative of constitutive expression of the nodY::lacZ reporter gene, were isolated. Beta-galactosidase activity assays revealed that while all of the 10 strains were sensitive to low concentrations of genistein, none exhibited truly constitutive nodY::lacZ expression in liquid culture. Soybean plants inoculated with three of the mutants were chlorotic and stunted, with shoot dry weights close to those of the uninoculated plants, indicating the absence of nitrogen fixation. Differences in the kinetics of nodY::lacZ expression and lipochitin oligosaccharide Nod signal production suggested that the strains carried different mutations. Some of these strains may be useful in mitigating the low root zone temperature-associated delay in soybean nodulation at the northern extent of soybean cultivation.

Bradyrhizobium↗
PubMed2001

Mouse epididymal Spam1 (PH-20) is released in vivo and in vitro, and Spam1 is differentially regulated in testis and epididymis.

The sperm adhesion molecule 1 (SPAM1 or PH-20) is an important sperm surface protein with a hyaluronidase activity and bifunctional roles in mammalian fertilization. Recently we reported that in the mouse, Spam1 is synthesized independently in the testis and the epididymis, where it is found in membranous vesicles in the principal cells of the epithelium in all three regions. Here we used mouse epididymal luminal fluid and cultured epididymal epithelial cells to demonstrate that epididymal Spam1 may be a secretory protein. Using a dual environment culture chamber system in which corpus or cauda epithelial cells are cocultured with their corresponding epididymal fibroblasts in medium supplemented with androgens and epidermal growth factor, we show that in 2- to 6-day cultures Spam1 can be detected immunocytochemically in the epithelial cells. The protein was also detected by Western blot analysis in extracts of the cultured cells and in their serum-free conditioned medium, as well as in luminal fluid from fresh caput, corpus, and caudal epididymis. Importantly, it was shown to have hyaluronidase activity, using hyaluronic acid substrate gel electrophoresis, and to be expressed in greater quantities in the corpus compared with the cauda and caput. The results not only confirm our previous finding that Spam1 is synthesized in the epididymis, but extend them by showing that it is released in the luminal fluid where it may effect posttesticular maturation and function of sperm. Results from transcript analysis indicate that epididymal and testicular Spam1 are under different transcriptional regulation.

Androgens↗
PubMed2001

Rhenium-188 HEDP to treat painful bone metastases.

PURPOSE: Rhenium-188 hydroxyethylidine diphosphonate (HEDP) is a new and attractive radiopharmaceutical that localizes in skeletal metastases and emits beta particles that may be therapeutically beneficial. In this study, the therapeutic efficacy of Re-188 HEDP was investigated in an uncontrolled initial trial of 61 patients with different types of advanced cancer for the palliation of painful bone metastases. MATERIALS AND METHODS: Sixty-one patients with painful bone metastases of lung, prostate, breast, renal, rhinopharyngeal, and bladder cancers were treated with 1.1 GBq (31 mCi) to 6.9 GBq (188 mCi) Re-188 HEDP. After treatment, the patients were followed at weekly intervals for the first 2 months and monthly thereafter for as long as 1 year. Hematologic function tests were also performed before and after treatment for 6 weeks. Pain responses were scored according to a three-point pain-rating scale as complete, significant, and minimal. RESULTS: Prompt and significant relief of bone pain occurred in 80% of patients overall. Of the specific tumor types, pain relief was achieved in 77% of patients with lung cancer, in 80% with prostate cancer, in 83% with breast cancer, in 100% with bladder cancer, in 50% with renal cancer, in 50% with rhinopharyngeal cancer, and in 87% of patients with other tumor types, with no severe side effects or hematopoietic toxicity. CONCLUSION: This large clinical trial verified that Re-188 HEDP is a useful radiopharmaceutical agent to treat painful bone metastases from various tumor types.

Bone Neoplasms↗
PubMed2001

Effects of alpha - and beta -adrenergic stimulation on hepatosplanchnic perfusion and oxygen extraction in endotoxic shock.

OBJECTIVE: To examine the effects of adrenergic stimulation on hepatosplanchnic perfusion, oxygen extraction, and tumor necrosis factor-alpha production during endotoxic shock. DESIGN: In vivo, prospective, randomized, controlled, repeated-measures, experimental study. SETTING: Experimental physiology laboratory in a university teaching hospital. SUBJECTS: Twenty-one anesthetized and mechanically ventilated dogs. INTERVENTIONS: An intrapericardial catheter was positioned. Catheters for blood sampling were inserted into the right femoral artery, hepatic vein, portal vein, and pulmonary artery. Ultrasonic flow probes were placed around the portal vein, the hepatic artery, the mesenteric artery, the left renal artery, and the left femoral artery. Animals received 2 mg/kg of Escherichia coli endotoxin, followed by fluid resuscitation. Seven dogs received intravenous isoproterenol (0.1 microg/kg x min(-1)), seven received phenylephrine (1 microg/kg x min(-1)), and seven served as controls. Thirty minutes later, cardiac tamponade was introduced to study organ perfusion and tissue oxygen extraction capabilities. MAIN RESULTS: The isoproterenol group had a higher cardiac index and stroke index and lower systemic vascular resistance than the other groups. The phenylephrine group had a higher arterial pressure but a lower cardiac index than the isoproterenol group. The isoproterenol group had a higher hepatic artery blood flow than the other groups and a higher portal and mesenteric flow than the control group. Liver and gut mucosal blood flow was greater in the isoproterenol than in the phenylephrine group. The isoproterenol group had a lower global critical oxygen delivery than the other groups (8.8 +/- 1.3 vs. 13.1 +/- 2.0 (control) and 11.8 +/- 3.3 mL/kg x min(-1) (phenylephrine); both p < .05) and a higher liver critical oxygen extraction ratio than the control group. Isoproterenol tended to attenuate, but phenylephrine significantly increased, blood tumor necrosis factor levels. CONCLUSIONS: During endotoxic shock, beta-stimulation can improve hepatosplanchnic perfusion and enhance tissue oxygen extraction capabilities, whereas alpha-stimulation does not. In addition, alpha-adrenergic stimulation can increase tumor necrosis factor levels.

Adrenergic alpha-Agonists↗
PubMed2001

The DISC Predictive Scales (DPS): efficiently screening for diagnoses.

OBJECTIVE: To derive and test a series of brief diagnosis-specific scales to identify subjects who are at high probability of meeting diagnostic criteria and those who may safely be spared more extensive diagnostic inquiry. METHOD: Secondary data analysis of a large epidemiological data set (n = 1,286) produced a series of gate and contingent items for each diagnosis. Findings were replicated in a second retrospective analysis from a residential care sample (n = 884). The DISC Predictive Scales (DPS) were then used prospectively as a self-report questionnaire in two studies, in which parents (n = 128) and/or adolescents (n = 208) had subsequent diagnostic interviewing with the Diagnostic Interview Schedule for Children or the Schedule for Affective Disorders and Schizophrenia for School-Age Children. RESULTS: All analyses showed that gate item selection was valid and that any missed cases were due solely to inconsistent reports on the same questions. Screening performance of the full scales was shown to be good, and substantial reductions in scale length were not associated with significant changes in discriminatory power. CONCLUSIONS: The DPS can accurately determine subjects who can safely be spared further diagnostic inquiry in any diagnostic area. This has the potential to speed up structured diagnostic interviewing considerably. The full DPS can be used to screen accurately for cases of specific DSM-III-R disorders.

Adolescent↗
PubMed2001

On the mechanisms of cholinergic control of the sinoatrial node discharge.

It has been proposed that cholinergic agonists inhibit the sinoatrial node discharge by shifting the activation range of the hyperpolarization-activated inward current If to more negative values or by increasing potassium conductance. In the former instance, cesium will potentiate the cholinergic inhibition by blocking any residual If; in the latter instance, Cs+ and Ba2+ will antagonize the inhibitory action by blocking K+ channels. The changes in discharge induced by high and low concentrations of carbachol were studied using an electrophysiologic technique in isolated guinea pig sinoatrial node perfused in vitro in the absence and presence of different concentrations of Cs+ and Ba2+. In Tyrode solution, high carbachol concentrations (0.5-2 microM) slowed the sinoatrial node by hyperpolarizing the membrane and by reducing the amplitude of diastolic depolarization; and stopped the sinoatrial node by preventing the attainment of threshold potential. Adding Cs+ (10 mM) to carbachol increased the rate in slowly discharging sinoatrial node and induced spontaneous discharge in quiescent sinoatrial node. In high [K+]o (approximately 12 mM), carbachol slowed or stopped the slow responses and adding Cs+ accelerated or induced discharge. Both in Tyode and in high [K+]o, in the presence of Cs+, carbachol did stop the sinoatrial node. In the presence of carbachol, Ba2+ (0.1 mM) accelerated or induced discharge, as Cs+ did. Atropine (1 microM) prevented both the slowing or suppression by carbachol and the acceleration of sinoatrial node by Cs+ in the presence of carbachol. Low carbachol concentrations (0.05-0.1 microM) decreased the rate to a similar extent in the absence and the presence of a low concentration of Cs+ (2 mM, which blocks If but not K+ channels), but markedly less in the presence of 0.5-0.75 mM Ba2+ (which block K+ channels but not If). We conclude that cholinergic agonists slow or stop the sinoatrial node by a shifting the membrane potential toward the more negative subsidiary pacemaker range and away from the threshold. The results with Cs+ and Ba2+ indicate that both high and low concentrations of carbachol decrease sinoatrial node discharge by activating the I(K,ACh) channels rather than by decreasing If.

Animals↗
PubMed2001

Tumour detectability in 2-dimensional and 3-dimensional positron emission tomography using the SET-2400W: a phantom study.

The purpose of this study was to investigate the detectability of small hot lesions in 2-dimensional transmission+emission (2D T/E), 2-dimensional simultaneous transmission+emission (2D simultaneous T/E) and 3-dimensional transmission+emission (3D T/E) acquisition modes in an 18F-fluorodeoxyglucose positron emission tomography (FDG PET) scan. The correlation between target detectability, target size, target to non-target uptake ratio (T/N ratio), and standardized uptake value (SUV) were studied. Small hot lesions ranging from 4.4 mm to 36.9 mm in diameter were set in a cylindrical phantom. The images of phantoms with T/N ratios of 2.0, 4.0, 6.0, 8.0, 9.6, 13.2, 17.5, 23.8 and 30.3 were obtained in 2D T/E, 2D simultaneous T/E and 3D T/E scans. Tumour uptake of 2-[18F]fluoro-2-deoxy-d-glucose (FDG) in a rabbit bearing VX-2 tumours was also studied in 2D T/E, 2D simultaneous T/E and 3D T/E scans. The target with a diameter > 10.6 mm and an actual T/N ratio from 6.0 to 30.3 could be identified on the images obtained with all the 2D T/E, 2D simultaneous T/E and 3D T/E acquisition modes. The detectability efficiency of a small hot target was found to be 77.8% in 2D T/E and 3D T/E, but 75.9% in 2D simultaneous T/E. The T/N ratio and recovery coefficient (RC) of the target from the 2D simultaneous T/E image was very similar to that from 2D T/E, and the SUV of the target from the 2D T/E image was almost the same as that from the 2D simultaneous T/E and 3D T/E images. This study indicated that 2D simultaneous T/E scanning and 3D T/E had similar abilities for detecting the tumour as did 2D T/E scanning. 2D T/E, 2D simultaneous T/E and 3D T/E scanning had the same feasibility for semi-quantitative analysis using SUV, as well as using the T/N ratios for 2D T/E and 2D simultaneous T/E. In contrast, the use of the T/N ratio in 3D T/E scanning gave an inferior result in semi-quantative analysis, although there might have been an improvement if a scatter correction had been performed.

Animals↗
PubMed2001

Effects of dobutamine on hepato-splanchnic hemodynamics in an experimental model of hyperdynamic endotoxic shock.

Dobutamine infusion has been proposed to increase splanchnic blood flow in septic conditions, but its' effects on liver blood flow and metabolism have not been well defined. We investigated the effects of dobutamine on liver blood flow, metabolism, and pathology in a canine hyperdynamic endotoxic shock model. Twenty-one dogs were anesthetized and paralyzed. After the administration of 2 mg/kg endotoxin, normal saline was infused to restore the pulmonary artery-occluded pressure to 10 mmHg. The dogs were then randomized to receive fluids either alone (n = 7) or combined with a dobutamine infusion at a rate of 5 (n = 7) or 10 microg/kg per min (n = 7). After initial fluid resuscitation, cardiac index (CI) increased from 152+/-48 to 386+/-97 mL/kg per min (P < 0.01) and then slightly decreased with time in the control group, but further increased to 458+/-54 mL/kg per min (P< 0.05) and remained elevated in the group treated with 5 microg/kg per min of dobutamine. Portal vein and hepatic arterial blood flows followed a similar course and increased with fluid resuscitation. Both decreased with time in the control group, but further increased in the dobutamine-treated animals. Liver oxygen delivery (DO2liv) increased with fluids from 2.2+/-2.4 to 3.8+/-1.9 mL/kg per min (P < 0.01) and further increased in the dobutamine-treated animals to 4.1+/-1.2 mL/kg per min. This was associated with an increase in liver oxygen uptake from 1.6+/-1.6 to 2.9+/-1.1 mL/kg per min with fluid resuscitation and a further increase to 4.3+/-1.5 mL/kg per min with dobutamine administration. Lactate consumption and hepatic vein oxygen saturation increased with initial fluid resuscitation and then decreased with time in the control group, but not in the dobutamine-treated animals. Increasing the dose of dobutamine to 10 microg/kg per min did not alter this response. At the end of the experiment, liver tissue samples were obtained for microscopic studies. The histological lesions seen in the control group were unaffected by dobutamine. In conclusion, dobutamine increases liver blood flow and metabolism, but does not affect microscopic findings in this hyperdynamic endotoxic shock model.

Adrenergic beta-Agonists↗
PubMed2001

Effects of nucleoside transport inhibition on hepatosplanchnic perfusion, oxygen extraction capabilities, and TNF release during acute endotoxic shock.

We explored the effects of the nucleoside transport inhibitor draflazine on regional blood flow, O2 extraction capabilities, and tumor necrosis factor (TNF) release in acute endotoxic shock. Fourteen anesthetized and mechanically ventilated dogs received 2 mg/kg of Escherichia coli endotoxin and were divided into two groups. Seven dogs received 0.1 mg/kg of draflazine 30 min before endotoxin, and 7 dogs served as a control group. Draflazine decreased arterial pressure without influencing cardiac index. Mesenteric and portal blood flow and ileum mucosal perfusion increased, but renal blood flow dramatically decreased. After endotoxemia, the draflazine-treated dogs had a lesser fall in cardiac index, filling pressures, and left ventricular stroke work index, and a lesser increase in pulmonary vascular resistance. After fluid resuscitation, they had a consistently lower renal blood flow and ileum mucosal perfusion, but a higher mixed venous and hepatic oxygen saturation and arterial pH than the control group. When cardiac index was reduced by tamponade to study the O2 extraction capabilities, renal blood flow and ileum mucosal perfusion remained lower in the draflazine group. Draflazine did not influence whole-body O2 extraction capabilities, but it delayed the occurrence of liver O2 supply dependency as indicated by a significantly lower liver DO2crit (27.7 +/- 3.9 vs. 43.3 +/- 10.8 mL/min) and a higher O2ERcrit (62.7 +/- 9.5 vs. 42.5 +/- 7.1%) than controls (both P< 0.05). On the other hand, draflazine increased intestinal DO2crit (42.4 +/- 15.4 vs. 27.7 +/- 6.5 mL/min, P < 0.05) compared to the control group. TNF levels remained higher in the draflazine group than in the control group, particularly 3 and 4 h after endotoxin administration. We conclude that nucleoside transport inhibition with draflazine does not alter global and hepatosplanchnic hemodynamics but may decrease gut mucosal perfusion and renal blood flow. However, this intervention can improve liver O2 extraction capabilities in acute endotoxic shock.

Animals↗
PubMed2001

Bis[2,2'-ethylenedioxydibenzaldehyde bis(thiocarbohydrazide)] tris(pyridine) solvate.

The title compound, a novel 30-membered 2:2 macrocyclic thiocarbohydrazone, C(34)H(32)N(8)O(4)S(2) x 3C(5)H(5)N, has been prepared and crystallographically characterized. The molecule of the compound is twisted. One dioxabutane group is boat-like in shape, whereas the other is highly disordered. The crystal structure is stabilized by inter- and intramolecular hydrogen bonds.

Journal Article↗
PubMed2001

SCH-202676: An allosteric modulator of both agonist and antagonist binding to G protein-coupled receptors.

A novel thiadiazole compound, SCH-202676 (N-(2,3-diphenyl-1,2, 4-thiadiazol-5-(2H)-ylidene)methanamine), has been identified as an inhibitor of both agonist and antagonist binding to G protein-coupled receptors (GPCRs). SCH-202676 inhibited radioligand binding to a number of structurally distinct, heterologously expressed GPCRs, including the human mu-, delta-, and kappa-opioid, alpha- and beta-adrenergic, muscarinic M1 and M2, and dopaminergic D1 and D2 receptors, but not to the tyrosine kinase epidermal growth factor receptor. SCH-202676 had no direct effect on G protein activity as assessed by [35S]guanosine-5'-O-(gamma-thio)triphosphate binding to purified recombinant G(oalpha)- or G(betagamma)-stimulated ADP-ribosylation of G(oalpha) by pertussis toxin. In addition, SCH-202676 inhibited antagonist binding to the beta2-adrenergic receptor expressed in Escherichia coli, a system devoid of classical heterotrimeric G proteins. SCH-202676 inhibited radiolabeled agonist and antagonist binding to the alpha2a-adrenergic receptor with an IC50 value of 0.5 microM, decreased the Bmax value of the binding sites with a slight increase in the KD value, and inhibited agonist-induced activation of the receptor. The effects of SCH-202676 were reversible. Incubation of plasma membranes with 10 microM SCH-202676 did not alter subsequent radioligand binding to the alpha2a-adrenergic receptor and the dopaminergic D1 receptor. Taken together, our data suggest that SCH-202676 has the unique ability to allosterically regulate agonist and antagonist binding to GPCRs in a manner that is both selective and reversible. The scope of the data presented suggests this occurs by direct interaction with a structural motif common to a large number of GPCRs or by activation/inhibition of an unidentified accessory protein that regulates GPCR function.

Adrenergic Agents↗
PubMed2001

Specific inhibition of coxsackievirus B3 translation and replication by phosphorothioate antisense oligodeoxynucleotides.

The 5' and 3' untranslated regions (UTRs) of coxsackievirus B3 (CVB3) RNA form highly ordered secondary structures that have been confirmed to play important regulatory roles in viral cap-independent internal translation initiation and RNA replication. We previously demonstrated that deletions in different regions of the 5' UTR significantly reduced viral RNA translation and infectivity. Such observations suggested strongly that viral RNA translation and replication could be blocked if highly specific antisense oligodeoxynucleotides (AS-ODNs) were applied to target crucial sites within the 5' and 3' UTRs. In this study, seven phosphorothioate AS-ODNs were synthesized, and the antiviral activity was evaluated by Lipofectin transfection of HeLa cells with AS-ODNs followed by infection of CVB3. Analysis by Western blotting, reverse transcription-PCR, and viral plaque assay demonstrated that viral protein synthesis, genome replication, and infectivity of CVB3 were strongly inhibited by the AS-ODNs complementary to different regions of the 5' and 3' UTRs. The most effective sites are located at the proximate terminus of the 5' UTR (AS-1), the proximate terminus of the 3' UTR (AS-7), the core sequence of the internal ribosome entry site (AS-2), and the translation initiation codon region (AS-4). These AS-ODNs showed highly sequence-specific and dose-dependent inhibitory effects on both viral protein synthesis and RNA replication. It is noteworthy that the highest inhibitory activities were obtained with AS-1 and AS-7 targeting the termini of the 5' and 3' UTRs. The percent inhibition values of AS-1 and AS-7 for CVB3 protein VP1 synthesis and RNA replication were 70.6 and 79.6 for AS-1 and 73.7 and 79.7 for AS-7, respectively. These data suggest that CVB3 infectivity can be inhibited effectively by AS-ODNs.

Enterovirus B, Human↗
PubMed2001

Kinetics of perchlorate- and chlorate-respiring bacteria.

Ten chlorate-respiring bacteria were isolated from wastewater and a perchlorate-degrading bioreactor. Eight of the isolates were able to degrade perchlorate, and all isolates used oxygen and chlorate as terminal electron acceptors. The growth kinetics of two perchlorate-degrading isolates, designated "Dechlorosoma" sp. strains KJ and PDX, were examined with acetate as the electron donor in batch tests. The maximum observed aerobic growth rates of KJ and PDX (0.27 and 0.28 h(-1), respectively) were only slightly higher than the anoxic growth rates obtained by these isolates during growth with chlorate (0.26 and 0.21 h(-1), respectively). The maximum observed growth rates of the two non-perchlorate-utilizing isolates (PDA and PDB) were much higher under aerobic conditions (0.64 and 0.41 h(-1), respectively) than under anoxic (chlorate-reducing) conditions (0.18 and 0.21 h(-1), respectively). The maximum growth rates of PDX on perchlorate and chlorate were identical (0.21 h(-1)) and exceeded that of strain KJ on perchlorate (0.14 h(-1)). Growth of one isolate (PDX) was more rapid on acetate than on lactate. There were substantial differences in the half-saturation constants measured for anoxic growth of isolates on acetate with excess perchlorate (470 mg/liter for KJ and 45 mg/liter for PDX). Biomass yields (grams of cells per gram of acetate) for strain KJ were not statistically different in the presence of the electron acceptors oxygen (0.46 +/- 0.07 [n = 7]), chlorate (0.44 +/- 0.05 [n = 7]), and perchlorate (0.50 +/- 0.08 [n = 7]). These studies provide evidence that facultative microorganisms with the capability for perchlorate and chlorate respiration exist, that not all chlorate-respiring microorganisms are capable of anoxic growth on perchlorate, and that isolates have dissimilar growth kinetics using different electron donors and acceptors.

Betaproteobacteria↗
PubMed2001

Detection of sporadic cases of hepatitis E virus (HEV) infection in China using immunoassays based on recombinant open reading frame 2 and 3 polypeptides from HEV genotype 4.

We reported previously on the complete sequence of hepatitis E virus (HEV) genotype 4, isolated from patients with sporadic cases of acute HEV infection in China. At least eight HEV genotypes have now been described worldwide, and further isolates await classification. Current immunoassays for the detection of anti-HEV antibodies are based on polypeptides from genotypes 1 and 2 only and may be inadequate for the reliable detection of other genotypes. Because genotypes 1 and 4 predominate in China, we wished to investigate the antigenic reactivities of HEV genotype 4 proteins. Four overlapping regions of open reading frame 2 (ORF2) (FB5, amino acids [aa] 1 to 130; E4, aa 67 to 308; F2-2, aa 288 to 461; E5, aa 414 to 672) and the entire ORF3 product were expressed in Escherichia coli as fusion proteins. Enzyme immunoassays based on each of the five purified polypeptides were evaluated with sera from patients with sporadic cases of acute HEV infection. Individual immunoassays derived from HEV genotype 4 detected more cases of acute hepatitis E than a commercial assay. Some serum samples, which were positive for anti-HEV immunoglobulin G only by assays based on HEV genotype 4, were positive for HEV RNA by reverse transcription-PCR. Polypeptide FB5, from the N terminus of ORF2, had the greatest immunoreactivity with sera from patients with acute hepatitis E. These data indicate that the N terminus of ORF2 may provide epitopes which are highly reactive with acute-phase sera and that assays based on genotypes 1 and 2 alone may be inadequate for the detection of HEV infection in China, where sporadic cases of HEV infection are caused predominantly by HEV genotypes 4 and 1.

Acute Disease↗