Properties of Cosmic Deuterons Measured by the Alpha Magnetic Spectrometer

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×10^{6} D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the D flux exhibits nearly identical time variations with the p, ^{3}He, and ^{4}He fluxes. Above 4.5 GV, the D/^{4}He flux ratio is time independent and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ_{D/^{4}He}=-0.108±0.005. This is in contrast with the ^{3}He/^{4}He flux ratio for which we find Δ_{^{3}He/^{4}He}=-0.289±0.003. Above ∼13  GV we find a nearly identical rigidity dependence of the D and p fluxes with a D/p flux ratio of 0.027±0.001. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the D flux equal to 9.4±0.5% of the ^{4}He flux and the secondary component of the D flux equal to 58±5% of the ^{3}He flux.

[Cost-effectiveness of HCV testing strategies for hepatitis C elimination in general population in China]

Objective: To evaluate the cost-effectiveness of hepatitis C screening in general population in China, and find the age group in which hepatitis C screening can achieve the best cost-effectiveness. Methods: A decision-Markov model was constructed by using software TreeAge pro 2019 to simulate the outcomes of hepatitis C disease pregression of 100 000 persons aged 20-59 years. The cost-effectiveness of the strategies were evaluated from societal perspectives by using incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB). One-way sensitivity analysis and probability sensitivity analysis were used to evaluate the uncertainty of parameters and model. Results: Hepatitis C screening was cost-effective in people aged 20- 59 years and the cost effectiveness was best in age group 40-49 years. Compared with non-screening strategy of hepatitis C in people aged 20-59 years, the incremental cost was 161.24 yuan, the incremental utility was 0.003 6 quality adjusted life years (QALYs)/per person, ICER was 45 197.26 yuan/QALY, ICER was less than the willing payment threshold. The ICER and NMB in all age groups were 42 055.06-53 249.43 yuan/QALY and 96.52-169.86 yuan/per person. Hepatitis C screening in people aged 40-49 years had the best cost-effectiveness. The results of one-way sensitivity analysis showed that the discount rate, anti-HCV detection cost, anti-HCV infection rate and the cost of direct antiviral agents were the main factors influencing economic evaluation. The results of the probability sensitivity analysis indicated that the model analysis was stable. Conclusions: Implementing hepatitis C screening based on medical institutions is cost-effective in people aged 20- 59 years, especially in those aged 40-49 years. Implementing the HCV screening strategy of be willing to test as far as possible in general population can reduce hepatitis C disease burden in China.

Application of xenogeneic anti-canine distemper virus antibodies in treatment of canine distemper puppies

OBJECTIVE

The clinical feasibility of passive immunotherapy has not been demonstrated in dogs naturally infected with canine distemper. In this study, porcine anti-canine distemper virus IgG and F(ab')₂ antibody fragments were used to treat infected puppies.

METHODS

A total of 41 naturally infected puppies (age Äsix months) exhibiting severe respiratory signs, but lacking neurological signs, were enrolled in the study. Twenty-five puppies were treated with a combination of IgG or F(ab')₂ antibody fragments (Group 1) and supportive therapy and 16 puppies received routine supportive care only (Group 2).

RESULTS

The survival rate of dogs in Group 1 (19/25; 76%) was significantly higher than that in Group 2 (5/16; 31·3%) (P<0·05). During the therapy, 8 of the 25 dogs (32%) in Group 1 developed neurological signs versus 12 of the 16 dogs (75%) in Group 2 (P<0·05). Adverse reactions were limited to elevated body temperature in dogs that received IgG antibodies.

CLINICAL SIGNIFICANCE

Porcine anti-canine distemper virus antibodies improved survival in puppies affected with canine distemper with minimal adverse effects. Therefore, this therapy could be considered for treatment of endangered animal species infected with canine distemper virus.

Isolation of a novel polyomavirus, related to Japanese eel endothelial cell-infecting virus, from marbled eels, Anguilla marmorata (Quoy & Gaimard)

Marbled eels, Anguilla marmorata (Quoy & Gaimard), cultured in Taiwan exhibited haemorrhage and mortality in January 2012. The severely diseased eels bled from the gills and showed congestion of the central venous sinus of the gill filaments and haemorrhage throughout the body similar to viral endothelial cell necrosis of eel. In this study, a novel polyomavirus (AmPyV) was isolated from the diseased eels using the AMPF cell line established from the pectoral fin of healthy marbled eels. AmPyV was found to encode a long T-antigen orthologous gene. Phylogenetic analysis showed that AmPyV was closely related to Japanese eel endothelial cell-infecting virus. PCR assays revealed AmPyV infection throughout the systemic organs. AmPyV proliferated in the AMPF, EK-1 and EO-2 cells at temperatures 25-30 °C, and the progeny virus yields were 10(7.0) , 10(7.4) and 10(7.7) TCID50  mL(-1) , respectively. The purified virions were icosahedral particles, 70-80 nm in diameter. No clinical signs or mortality was observed among the eels injected with the virus; however, the virus was reisolated from the brain, eyes, kidneys, fins and gills of infected eels 2 month after injection. Our results suggest that AmPyV exhibits a latent infection. Pathogen of the disease needs to study further.

Termination of two-dimensional metallic conduction near the metal-insulator transition in a Si/SiGe quantum well

We report in this Letter our recent low-temperature transport results in a Si/SiGe quantum well with moderate peak mobility. An apparent metal-insulating transition is observed. Within a small range of densities near the transition, the conductivity σ displays a nonmonotonic temperature dependence. After an initial decrease at high temperatures, σ first increases with decreasing temperature T, showing a metallic behavior. As T continues decreasing, a downturn in σ is observed. This downturn shifts to a lower T at higher densities. More interestingly, the downturn temperature shows a power-law dependence on the mobility at the downturn position, suggesting that a similar downturn is also expected to occur deep in the apparent metallic regime at albeit experimentally inaccessible temperatures. This thus hints that the observed metallic phase in 2D systems might be a finite temperature effect.

Malignancies associated with dermatomyositis and polymyositis in Taiwan: a nationwide population-based study

BACKGROUND

Previous studies showed that idiopathic inflammatory myopathies (IIM) carried an increased risk of cancers. However, no large-scale study of IIM has been conducted in the Chinese population.

OBJECTIVES

We sought to delineate the association of IIM and various cancer types from a nationwide database in Taiwan.

METHODS

We analysed the published national data from records of National Health Insurance claims. Cases of dermatomyositis (DM) and polymyositis (PM) from 2000 to 2005 and cancers registered in the catastrophic illness profile from 1997 to 2006 were collected. A nationally representative cohort of 1,000,000 enrollees was included for comparison.

RESULTS

In total, 136 patients (12.8%) among 1059 cases of DM and 46 persons (7.0%) among 661 cases of PM carried internal malignancies. Patients with DM tended to have cancers of nasopharynx, lung and breast. On the other hand, patients with PM tended to have breast, uterine cervix and lung cancers. Compared with the general population, DM gave a 10-fold increased risk for cancers, in which a 66-fold increased risk for nasopharyngeal carcinoma and a 31-fold increased risk for lung cancer were the two most significant. For patients with PM, a 6-fold increased risk for cancer was observed. Juvenile DM had a 16-fold increased risk for haematopoietic or lymphoid malignancy. Two thirds of comorbid malignancies were detected shortly after the diagnoses of IIM, within a mean of 1-2 years. Overall, younger patients with IIM carried the highest risk for malignancies, especially those in their twenties and thirties.

CONCLUSIONS

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.

Pathogenesis of gastroenteritis caused by Vibrio carchariae in cultured marine fish

Serious mortality among the cultured grouper Epinephelus coioides, characterized by a swollen intestine containing yellow fluid (gastroenteritis), occurred in 1993 in Taiwan. A bacterium isolated from the intestinal fluid and head kidney of moribund groupers was identified as Vibrio carchariae. Since then, the same Vibrio species has also been isolated from moribund black sea bream Acanthopagrus schlegeli, yellowfin sea bream A. latus, Japanese sea bass Lateolabrax japonicus, and red drum Sciaenops ocellatus suffering from the same syndrome. Each isolate was virulent to the respective fish. Recently, a similar syndrome, flounder infectious necrotizing enteritis, also caused by V. carchariae in summer flounder Paralichthys dentatus, was reported in Rhode Island. The extracellular products (ECPs) of V. carchariae strains EmI82KL (from grouper), Rd (from red drum), and SfUSA (from summer flounder, U.S.A.) were virulent to the grouper or red drum. A 33-kDa serine protease partially purified from the ECP of strain EmI82KL was lethal to the fish. All the moribund or killed fish exhibited gastroenteritis except those killed within 12 hours. This report is the first to show that intraperitoneal injection of the ECP or protease in the fish is virulent and can reproduce gastroenteritis. The serine protease was suggested as a major toxin in the grouper or red drum secreted by V. carchariae.

Novel stress-responsive genes EMG1 and NOP14 encode conserved, interacting proteins required for 40S ribosome biogenesis

Under stressful conditions organisms adjust the synthesis, processing, and trafficking of molecules to allow survival from and recovery after stress. In baker's yeast Saccharomyces cerevisiae, the cellular production of ribosomes is tightly matched with environmental conditions and nutrient availability through coordinate transcriptional regulation of genes involved in ribosome biogenesis. On the basis of stress-responsive gene expression and functional studies, we have identified a novel, evolutionarily conserved gene, EMG1, that has similar stress-responsive gene expression patterns as ribosomal protein genes and is required for the biogenesis of the 40S ribosomal subunit. The Emg1 protein is distributed throughout the cell; however, its nuclear localization depends on physical interaction with a newly characterized nucleolar protein, Nop14. Yeast depleted of Nop14 or harboring a temperature-sensitive allele of emg1 have selectively reduced levels of the 20S pre-rRNA and mature18S rRNA and diminished cellular levels of the 40S ribosomal subunit. Neither Emg1 nor Nop14 contain any characterized functional motifs; however, isolation and functional analyses of mammalian orthologues of Emg1 and Nop14 suggest that these proteins are functionally conserved among eukaryotes. We conclude that Emg1 and Nop14 are novel proteins whose interaction is required for the maturation of the 18S rRNA and for 40S ribosome production.

Withering syndrome of the small abalone, Haliotis diversicolor supertexta, is caused by Vibrio parahaemolyticus and associated with thermal induction

The susceptibility of the small abalone Haliotis diversicolor supertexta to Vibrio parahaemolyticus 880915 strain and its extracellular products (ECP) at different temperatures was investigated. The strain was previously isolated from the haemolymph of the moribund small abalone with withering syndrome during an outbreak of mass mortality among the cultured animals in September 1999 in I-Lan, Taiwan. The bacterium and its ECP were lethal to the small abalone. Onset of the withering syndrome in the moribund or dead animals could be observed at 4-7 d post-bacterial challenge. The same bacterial strain could be isolated from the haemolymph of the moribund animals with or without the syndrome post-bacterial challenge. This syndrome could not be observed in the moribund or dead animals post-ECP challenge. The animals were more susceptible to the bacterium and ECP challenge at higher temperature (28 degrees C) indicating that the outbreak of the disease in warmer season is associated with thermal induction.

The loop domain of heat shock transcription factor 1 dictates DNA-binding specificity and responses to heat stress

Eukaryotic heat shock transcription factors (HSF) regulate an evolutionarily conserved stress-response pathway essential for survival against a variety of environmental and developmental stresses. Although the highly similar HSF family members have distinct roles in responding to stress and activating target gene expression, the mechanisms that govern these roles are unknown. Here we identify a loop within the HSF1 DNA-binding domain that dictates HSF isoform specific DNA binding in vitro and preferential target gene activation by HSF family members in both a yeast transcription assay and in mammalian cells. These characteristics of the HSF1 loop region are transposable to HSF2 and sufficient to confer DNA-binding specificity, heat shock inducible HSP gene expression and protection from heat-induced apoptosis in vivo. In addition, the loop suppresses formation of the HSF1 trimer under basal conditions and is required for heat-inducible trimerization in a purified system in vitro, suggesting that this domain is a critical part of the HSF1 heat-stress-sensing mechanism. We propose that this domain defines a signature for HSF1 that constitutes an important determinant for how cells utilize a family of transcription factors to respond to distinct stresses.

Pathogenicity of Vibrio alginolyticus isolated from diseased small abalone Haliotis diversicolor supertexta

Outbreaks of mass mortality among cultured small abalone Haliotis diversicolor supertexta with abscess/ulcers in the mantle occurred in 1998 at Kao-Hsiung, Taiwan. A swarming bacterium, strain H-11 was isolated from the haemolymph of the moribund small abalone using tryptic soy agar supplemented with 3% NaCl and/or thiosulphate citrate bile salt sucrose agar. This strain was characterized and identified as Vibrio alginolyticus on the basis of various biochemical tests. The H-11 strain and its extracellular products were virulent to small abalones with LD50 values of 3.6 x 10(5) colony forming units and 2.96 microg protein/g body weight, respectively.

Virulence of Vibrio parahaemolyticus isolated from cultured small abalone, Haliotis diversicolor supertexta, with withering syndrome

Outbreaks of mass mortality among cultured small abalone Haliotis diversicolor supertexta with withering syndrome occurred in May and September 1998 in Kao-Hsiung, Taiwan. Bacterial strains CH-1 and B4 were isolated from the haemolymph of the moribund small abalone using tryptic soy agar supplemented with 3% NaCl and/or thiosulphate citrate bile salt sucrose agar. These two strains were characterized and identified as Vibrio parahaemolyticus on the basis of various biochemical tests. The B4 strain and its extracellular products were virulent to small abalone with LD(50) values of 1.6 x 10(5) colony-forming units and 7.58 microg protein g-1 body weight, respectively.

Purification and partial characterization of a toxic serine protease produced by pathogenic Vibrio alginolyticus

An extracellular lethal toxin produced by Vibrio alginolyticus strain Swy originally isolated from diseased kuruma prawn (Penaeus japonicus) was purified using the AKTA purifier system with hydrophobic interaction chromatography, anion exchange and gel filtration columns. The toxin is an alkaline serine protease, inhibited by phenyl methylsulphonyl fluoride (PMSF), antipain and shows maximal activity at pH 8 to 11, having a pI of 4.3 and a molecular weight of approximately 33 kD. The toxin was completely inhibited by FeCl2 but partially inhibited by 3,4-dichloroisocoumarin (3,4-DCI), ethylenediamine tetraacetic acid (EDTA), ethylene glycol-bis(beta-amino-ethyl ether) N,N,N',N'-tetraacetic acid (EGTA), CuCl2 and ZnCl2. The purified protease was lethal for kuruma prawn at an LD50 of 0.29 microgram protein/g body weight. The haemolymph withdrawn from the moribund prawns injected with the toxic protease was unable to clot. The coagulogen in the kuruma prawn plasma showed an increased migration rate after incubation with this serine protease, and a plasma colour change from blue to pink was recorded. The addition of PMSF completely inhibited the lethal toxicity of the purified protease, indicating that this serine protease was a lethal toxin produced by the bacterium. The 33 kD protease was therefore a toxic protease produced by V. alginolyticus strain Swy.

Lethal attribute of serine protease secreted by Vibrio alginolyticus strains in kuruma prawn Penaeus japonicus

Toxicity of the extracellular products (ECP) and the lethal attribute of serine protease secreted by five pathogenic Vibrio alginolyticus strains from various sources in kuruma prawn Penaeus japonicus were studied. The ECPs of organisms originally isolated from diseased kuruma prawn or small abalone Haliotis diversicolor supertexta were more lethal (LD50 value of 0.48 or 0.41 microg protein/g prawn) than those from diseased tiger prawn P. monodon, yellowfin porgy Acanthopagrus latus or horse mackerel (LD50 value of 0.98-1.17 microg protein/g prawn). All the ECPs manifested strong, weak and no activities against gelatin, sheep erythrocytes and chitin, respectively. In immunodiffusion tests using rabbit antiserum to a purified 33 kDa serine protease of strain Swy against ECP of each tested strain produced one single precipitation band in each treatment. Furthermore, the serine protease was suggested to be the dominant protease secreted by V. alginolyticus strains tested since the majority of enzymatic activity of the respective ECP was inhibited by phenylmethanesulfonyl fluoride (PMSF). A higher inhibition of serine protease activity by PMSF resulted in lower mortality rate of the ECPs injected into the prawns suggesting that the protease is one of the major lethal factor(s) secreted by V. alginolyticus.

Characterization and chromosomal mapping of a mouse ortholog of the late-infantile ceroid-lipofuscinosis gene CLN2

Late-infantile ceroid-lipofuscinosis (CLN2) is an autosomal recessively inherited, neurodegenerative disease in humans. The CLN2 locus has been mapped to Chromosome (Chr) 11p15, and its sequence and genomic organization have recently been reported. In the present study, the cDNA sequence, exon/intron organization, and chromosomal localization of a mouse ortholog of the CLN2 gene are described. The mouse cDNA contains an open reading frame that predicts a protein product of 562 amino acids. The mouse and human coding regions are 86% and 88% identical at the nucleic acid and amino acid levels, respectively. One less codon appears in the mouse cDNA when compared with the human ortholog. The mouse gene (Cln2) spans more than 6 kb and consists of 13 exons separated by introns ranging in size from 111 to 1259 bp. Length polymorphism in an (AC)(n) microsatellite in intron 3 of the mouse Cln2 gene was used to perform segregation analysis with The Jackson Laboratory DNA Panel Mapping Resource. On the basis of this analysis, the Cln2 gene was localized to a region of mouse Chr 7 that corresponds to human Chr 11p15. Characterization of the mouse Cln2 gene will facilitate generation of a mouse model for late-infantile ceroid-lipofuscinosis by gene targeting and identification of functionally important regions of the Cln2 protein.

Electrophoretic characterization of a novel cysteine protease produced by Vibrio harveyi

Electrophoretic characterization of a novel cysteine protease produced by pathogenic luminous Vibrio harveyi, originally isolated from diseased tiger prawn Penaeus monodon in Taiwan, is demonstrated in the present study using native polyacrylamide gel electrophoresis (native PAGE), sodium dodecyl sulfate-PAGE (SDS-PAGE), crossed immunoelectrophoresis (CIE) and isoelectric focusing (IEF) gels. The protease has a pI of 6.4 and exhibits a fast-migrating feature in native-PAGE and CIE gels indicating that it is a negatively charged protease. The protease electrophoresed as a 22 kDa protein band in native- and SDS-PAGE (in SDS - buffer with or without the presence of 2-mercaptoethanol) while it electrophoresed as a 38 kDa protein band in SDS-PAGE when the samples were boiled for 10 min prior to electrophoresis. The results reveal that the enzyme is an SDS-resistant monomeric protease and its high negative charge is not influenced by SDS (detergent) without boiling the sample. The present results are useful in determining proteins of similar nature to this unique cysteine protease.

The mammalian HSF4 gene generates both an activator and a repressor of heat shock genes by alternative splicing

The expression of heat shock genes is controlled at the level of transcription by members of the heat shock transcription factor family in vertebrates. HSF4 is a mammalian factor characterized by its lack of a suppression domain that modulates formation of DNA-binding homotrimer. Here, we have determined the exon structure of the human HSF4 gene and identified a major new isoform, HSF4b, derived by alternative RNA splicing events, in addition to a previously reported HSF4a isoform. In mouse tissues HSF4b mRNA was more abundant than HSF4a as examined by reverse transcription-polymerase chain reaction, and its protein was detected in the brain and lung. Although both mouse HSF4a and HSF4b form trimers in the absence of stress, these two isoforms exhibit different transcriptional activity; HSF4a acts as an inhibitor of the constitutive expression of heat shock genes, and hHSF4b acts as a transcriptional activator. Furthermore HSF4b but not HSF4a complements the viability defect of yeast cells lacking HSF. Moreover, heat shock and other stresses stimulate transcription of target genes by HSF4b in both yeast and mammalian cells. These results suggest that differential splicing of HSF4 mRNA gives rise to both an inhibitor and activator of tissue-specific heat shock gene expression.

Dual challenges of infectious pancreatic necrosis virus and Vibrio carchariae in the grouper, Epinephelus sp

The grouper industry in Taiwan faces serious threats from various disease problems. The present study investigated dual challenges with infectious pancreatic necrosis virus (IPNV) and Vibrio carchariae in the grouper (Epinephelus sp.). The fish were infected with IPNV for 2 weeks prior to a secondary infection with the bacteria, or vice versa, by either immersion (10(3)-10(4) TCID50 IPNV per ml, 10(6)-10(7) colony forming units (CFU) Vibrio per ml) or by intraperitoneal injection (10(3)-10(4) TCID50 IPNV per g fish or 10(7) CFU Vibrio/g fish) challenges. Mass mortalities occurred in fish infected with IPNV for 2 weeks prior to the infection with the bacteria, or vice versa, in either immersion or intraperitoneal injection challenges. The bacterium could only survive in seawater or brackish water similar to that of cultured groupers.

A mouse gene knockout model for juvenile ceroid-lipofuscinosis (Batten disease)

The human hereditary ceroid-lipofuscinoses are a group of autosomal recessively inherited diseases characterized by massive accumulations of autofluorescent lysosomal storage bodies in the cells of many tissues and by neuronal degeneration throughout the central nervous system. There are a number of clinically and genetically distinct forms of ceroid-lipofuscinosis, the most common of which is the juvenile type, also known as Batten disease and CLN3. To study the mechanisms that lead to pathology in CLN3 and to evaluate potential therapies, a mouse model has been generated by targeted disruption of the mouse ortholog of the CLN3 gene (Cln3). As in affected humans, mice homozygous for the disrupted Cln3 allele show accumulation of autofluorescent storage material in neurons and other cell types. The storage material consists of membrane-bounded intracellular inclusions with ultrastructural features typical of the ceroid-lipofuscinoses. The accumulation of this storage material validates the Cln3 knockout mice as a model for the human disorder.

An evaluation of chromogenic substrates for characterization of serine protease produced by pathogenic Vibrio alginolyticus

Four chromogenic substrates for characterizing serine protease of Vibrio alginolyticus were evaluated. The protease activity of bacterial extracellular products, or the fractions of 33 kD protease purified by the AKTA purifier system with various columns, was completely inhibited by ethylenediamine tetra-acetic acid, ethylene glycol-bis(beta-amino-ethyl ether) N,N,N',N'-tetraacetic acid (EGTA), antipain and phenylmethylsulphonyl fluoride (PMSF) using water-soluble substrates (azoalbumin and azocasein). It was only completely inhibited by antipain and PMSF using water-insoluble substrates (azocoll and hide powder azure). The protease activity was not, or only partially, inhibited by 1,10-phenanthroline and sodium dodecyl sulphate (SDS) using all four substrates. Since chelating agents and 1,10-phenanthroline are commonly employed as inhibitors to identify metalloprotease, the two water-soluble substrates may not be appropriate for this purpose, except for using 1,10-phenanthroline as an inhibitor. Chelating agents may be still applicable as inhibitors using water-insoluble substrates and 1,10-phenanthroline is highly recommended in the characterization for metalloprotease to avoid confusion. In the present study, the 33 kD protease was further confirmed as an SDS-resistant serine protease and not a metalloprotease.

Modulation of human heat shock factor trimerization by the linker domain

Heat shock transcription factors (HSFs) are stress-responsive proteins that activate the expression of heat shock genes and are highly conserved from bakers' yeast to humans. Under basal conditions, the human HSF1 protein is maintained as an inactive monomer through intramolecular interactions between two coiled-coil domains and interactions with heat shock proteins; upon environmental, pharmacological, or physiological stress, HSF1 is converted to a homotrimer that binds to its cognate DNA binding site with high affinity. To dissect regions of HSF1 that make important contributions to the stability of the monomer under unstressed conditions, we have used functional complementation in bakers' yeast as a facile assay system. Whereas wild-type human HSF1 is restrained as an inactive monomer in yeast that is unable to substitute for the essential yeast HSF protein, mutations in the linker region between the DNA binding domain and the first coiled-coil allow HSF1 to homotrimerize and rescue the viability defect of a hsfDelta strain. Fine mapping by functional analysis of HSF1-HSF2 chimeras and point mutagenesis revealed that a small region in the amino-terminal portion of the HSF1 linker is required for maintenance of HSF1 in the monomeric state in both yeast and in transfected human 293 cells. Although linker regions in transcription factors are known to modulate DNA binding specificity, our studies suggest that the human HSF1 linker plays no role in determining HSF1 binding preferences in vivo but is a critical determinant in regulating the HSF1 monomer-trimer equilibrium.

Cysteine protease is a major exotoxin of pathogenic luminous Vibrio harveyi in the tiger prawn, Penaeus monodon

The role of an extracellular cysteine protease, produced by pathogenic luminous Vibrio harveyi strain 820514 originally isolated from diseased tiger prawn (Penaeus monodon), in the disease process in the prawns was studied. The protease was lethal to P. monodon with an LD50 value of 0.3 microgram protein g-1 prawn. The lethal toxicity of the extracellular products (ECP) of the bacterium was neutralized by pre-incubation of the ECP with rabbit antiserum to the cysteine protease. Pre-incubation of ECP with CuCl2 (an inhibitor of cysteine protease) also inhibited toxicity. This suggests that cysteine protease is the major toxin produced by the bacterium. The present protease is the first toxic cysteine protease to be found in Vibrio species.