Caspase-3 activation as a key factor for HBx-transformed cell death

OBJECTIVES

Nuclear factor-kappa B (NF-kappaB) activation has been associated with the tumorigenic growth of hepatitis B virus X protein (HBx)-transformed cells. This study was aimed to find a key target for treatment of HBx-mediated cancers.

MATERIALS AND METHODS

NF-kappaB activation, endoplasmic reticulum-stress (ER-stress), caspase-3 activation, and cell proliferation were evaluated after Chang/HBx cells permanently expressing HBx viral protein were treated with inhibitors of NF-kappaB, proteasome and DNA topoisomerase.

RESULTS

Inhibition of NF-kappaB transcriptional activity by transient transfection with mutant plasmids encoding Akt1 and glycogen synthase kinase-3beta (GSK-3beta), or by treatment with chemical inhibitors, wortmannin and LY294002, showed little effect on the survival of Chang/HBx cells. Furthermore, IkappaBalpha (S32/36A) mutant plasmid or other NF-kappaB inhibitors, 1-pyrrolidinecarbonidithioic acid and sulphasalazine, were also shown to have little effect on the cell proliferation. By contrast, proteasome inhibitor-1 (Pro1) and MG132 enhanced the HBx-induced ER-stress response and the subsequent activation of caspase-12, -9 and -3 and reduced cell proliferation. Camptothecin (CPT), however, triggered activation of caspase-3 without induction of caspase-12, and reduced cell proliferation. In addition, CPT-induced cell death was reversed by pre-treatment with z-DEVD, a caspase-3-specific inhibitor.

CONCLUSIONS

Detailed exploitation of the regulators of caspase-3 activation could open the gate for finding an efficient target for development of anticancer therapeutics against HBx-transformed hepatocellular carcinoma.

Zebrafish as a model for infectious disease and immune function

The zebrafish, Danio rerio, has come to the forefront of biomedical research as a powerful model for the study of development, neurobiology, and genetics of humans. In recent years, use of the zebrafish system has extended into studies in behaviour, immunology and toxicology, retaining the concept that it will serve as a model for human disease. As one of the most thoroughly studied teleosts, with a wealth of genetic and genomic information available, the zebrafish is now being considered as a model for pathogen studies in finfishes. Its genome is currently being sequenced and annotated, and gene microarrays and insertional mutants are commercially available. The use of gene-specific knockdown of translation through morpholino oligonucleotides is widespread. As a result, several laboratories have developed bacterial and viral disease models with the zebrafish to study immune responses to infection. Although many of the zebrafish pathogen models were developed to address human infectious disease, the results of these studies should provide important clues for the development of effective vaccines and prophylactic measures against bacterial and viral pathogens in economically important fishes. In this review, the capabilities and potential of the zebrafish model system will be discussed and an overview of information on zebrafish infectious disease models will be presented.

Polymorphisms in the type IV collagen alpha3 gene and the risk of COPD

A number of genome-wide linkage analyses have identified the 2q33.3-2q37.2 region as the most likely to contain the genes that contribute to the susceptibility to chronic obstructive pulmonary disease (COPD). It was hypothesised that the type IV collagen alpha3 (COL4A3) gene, which is one of the genes located in the 2q33.3-2q37.2 region, may act as a low-penetrance susceptibility gene for COPD. To test this hypothesis, the association of COL4A3 -1162T>C, IVS2+12C>A, P141L, G162E, H451R, P574L and *315C>A polymorphisms with the risk of COPD was investigated in a case-control study of 311 COPD patients and 386 controls. The presence of at least one 451R allele was associated with a significantly higher risk of COPD compared with the 451 H/H genotype (adjusted odds ratio 1.48, 95% confidence interval (1.03-2.14)). When the subjects were stratified according to age and COPD severity, the 451R allele was associated with a significantly higher risk of COPD only in younger individuals with severe COPD (3.02 (1.37-6.67)). In conclusion, these findings suggest that the type IV collagen alpha3 gene contributes to the genetic susceptibility to chronic obstructive pulmonary disease.

Dopamine transporter density in the basal ganglia in obsessive-compulsive disorder, measured with [123I]IPT SPECT before and after treatment with serotonin reuptake inhibitors

It has been suggested that dopamine as well as serotonin are associated with the pathophysiology of obsessive-compulsive disorder (OCD). 5-Hydroxytryptophan inhibits dopamine release in healthy persons as well as in patients with OCD, and serotonin tonic inhibition affects dopamine function in basal ganglia, indicating a close relationship between serotonin and the dopamine system. Using iodine-123-labeled N-(3-iodopropen-2-yl)-2 beta-carbomethoxy-3beta-(4-chlorophenyl) tropane ([(123)I]IPT) single photon emission computed tomography (SPECT), we investigated the dopamine transporter (DAT) density in the basal ganglia of patients with OCD. The test consists of two measurements before and after treatment with serotonin reuptake inhibitors (SRIs). Ten patients with OCD before and after treatment with SRIs were included. We performed brain SPECT 2 h after intravenous administration of [(123)I]IPT using a dual-head SPECT camera (Vertex, ADAC, Calif., USA) and analyzed the SPECT data, reconstructed for the assessment of the specific/nonspecific DAT binding ratio in the basal ganglia. We then examined the correlation between the scores of OCD symptom changes, assessed with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), and DAT binding ratio. Patients with OCD after treatment with SRIs showed a significantly decreased DAT binding ratio in the right basal ganglia compared with baseline. A significant correlation was found between the total scores and compulsion score changes of the Y-BOCS and the changes of the DAT binding ratio of the right basal ganglia. These findings suggest that the dopaminergic neurotransmitter system of the basal ganglia could play an important role in the symptom improvement of OCD patients.

Inhibition of pseudointimal hyperplasia in swine TIPS models: the efficacy of local delivery of paclitaxel using a perforated balloon catheter

The aim of this study was to investigate the efficacy and feasibility of local delivery of paclitaxel to inhibit pseudointimal hyperplasia/intimal hyperplasia in swine transjugular intrahepatic portosystemic shunt (TIPS) models TIPS were created in seven healthy domestic swine (15-20 kg). Before TIPS stent insertion, we performed a short-term infusion of paclitaxel (treatment group: n = 4) and saline (control group: n = 3) into the TIPS tract using a balloon catheter in which two 0.010 inch holes were created on opposite sides of the balloon. Paclitaxel or saline was given to all animals via the hepatic parenchymal and venous outflow tract. The animals were followed for up to two weeks and then killed. Gross and histological evaluations of the shunts were performed, and the maximum pseudointimal/intimal hyperplasia thicknesses were calculated for each animal The average infusion time of paclitaxel or saline was 7.6 min (6-9 min). At gross and histological evaluation, considerable pseudointimal hyperplasia had formed in the control group and statistically significant differences were found upon microscopic evaluation in the maximum pseudointimal hyperplasia thickness between the control (2.41 mm, range 1.7-3.16 mm) and animals receiving paclitaxel (0.63 mm, range 0.42-0.98 mm, p<0.05) Local delivery of paclitaxel at the time of TIPS creation may have been effective in reducing pseudointimal/intimal hyperplasia in swine TIPS models.

Immunogenomic approaches to study host immunity to enteric pathogens

With increasing consumer demands for safe poultry products, effective control of disease-causing pathogens is becoming a major challenge to the poultry industry. Many chicken pathogens enter the host through the gastrointestinal tract, and over the past few decades, in-feed antibiotics and active vaccination have been the 2 main mechanisms of disease control. However, increasing public concerns are prompting government regulations on the use of growth-promoting drugs in animal production, and the ability of current vaccines to protect against emerging hypervirulent strains of pathogens is becoming an issue. Therefore, there is a need to develop alternative control strategies against poultry pathogens of economic importance as well as to carry out basic research to enhance understanding of host-pathogen interactions at local sites of infection. Effective control strategies against pathogens can only be accomplished by comprehensive analysis of the basic immunobiology of host-pathogen interactions. Recent sequencing of the poultry genome and the availability of several tissue-specific cDNA microarrays are facilitating the rapid application of functional immunogenomic technologies to poultry disease research. Studies using functional genomic, immunology, and bioinformatic approaches have provided novel insights into disease processes and protective immunity to chicken pathogens. In this review, we summarize recent published literature concerning the host response to Eimeria and Salmonella infections with emphasis on our studies using immunogenomic tools to investigate and characterize the mechanisms of avian immunity to these mucosal pathogens. The results clearly indicate that this immunogenomic approach will lead to increased understanding of immune responses to infectious agents that will enable the development of effective prevention strategies against mucosal pathogens.

Effects of Low Concentrations of Arsenic on the Innate Immune System of the Zebrafish (Danio Rerio)

Arsenic has been associated with a multitude of human health problems; however, its impact on host resistance to infection has not been extensively researched. In vertebrates, the innate immune response is vital for potentiating the adaptive immune response. Therefore, dampening of the innate immune response results in an immunocompromised host. In this present study, effects of low concentrations of arsenic on zebrafish resistance to infection are evaluated. Exposure to 2 and 10 ppb arsenic, both considered safe levels in drinking water, resulted in a greater than 50-fold increase in viral load and at least a 17-fold increase in bacterial load in embryos. To determine the cause of this amplified pathogen load, important components of the innate immune system were analyzed. Presence of arsenic dampened the overall innate immune health of the fish as evidenced by reductions in respiratory burst activity. Viral infection, after arsenic exposure, showed decreases of up to 13- and 1.5-fold changes in interferon and Mx mRNA expression, respectively. Bacterial infection, post arsenic exposure, demonstrated at least 2.5- and 4-fold declines in interleukin-1beta and tumor necrosis factor-alpha mRNA levels, respectively. Maximum expression of these essential cytokines was also delayed upon arsenic exposure. Our data indicate that arsenic exposure, at concentrations deemed safe in drinking water, suppresses the overall innate immune function in zebrafish and present the zebrafish as a unique model for studying immunotoxicity of environmental toxicants. To our knowledge, this is the first report describing the effects of such low levels of arsenic on host resistance to infection.

Evidence for Evolving Toll-IL-1 Receptor-Containing Adaptor Molecule Function in Vertebrates

In mammals, Toll-IL-1R-containing adaptor molecule 1 (TICAM1)-dependent TLR pathways induce NF-kappaB and IFN-beta responses. TICAM1 activates NF-kappaB through two different pathways involving its interactions with TNFR-associated factor 6 and receptor-interacting protein 1. It also activates IFN regulatory factor 3/7 through its interaction with TANK-binding kinase-1, leading to the robust up-regulation of IFN-beta. In this study, we describe the role of zebrafish (Danio rerio) TICAM1 in activating NF-kappaB and zebrafish type I IFN. Zebrafish IFN is unique in that it cannot be categorized as being alpha- or beta-like. Through comprehensive sequence, phylogenetic, and syntenic analyses, we fully describe the identification of a zebrafish TICAM1 ortholog. Zebrafish TICAM1 exhibits sequence divergence from its mammalian orthologs and our data demonstrate that these sequence differences have functional consequences. Zebrafish TICAM1 activates zebrafish IFN; however, it does so in an apparently IFN regulatory factor 3/7-independent manner. Furthermore, zebrafish TICAM1 does not interact with zebrafish TNFR-associated factor 6, thus NF-kappaB activation is dependent upon its interaction with receptor-interacting protein 1. Comparative genome analysis suggests that TICAM1 and TICAM2 evolved from a common vertebrate TICAM ancestor following a gene duplication event and that TICAM2 was lost in teleosts following the divergence of the rayfin and lobefin fishes 450 million years ago. These studies provide evidence, for the first time, of the evolving function of a vertebrate TLR pathway.

Post-marketing surveillance study of the efficacy and safety of vardenafil among patients with erectile dysfunction in primary care

To evaluate the safety and efficacy of vardenafil in primary care, we undertook a post-marketing surveillance study in 384 men with erectile dysfunction (ED), enrolled by 22 family physicians in Korea, from July 2004 to August 2005. Of the 384 patients enrolled, 343 (89.3%) returned for efficacy assessment and safety evaluation. Among the latter, 279 patients (81.3%) reported that their erectile function improved, 292 (92.1%) showed enhanced IIEF (International Index of Erectile Function)-5 scores and 265 (77.9%) responded that they were 'very satisfied' or 'satisfied' with vardenafil treatment. The most frequent reason for patient satisfaction with vardenafil was erectile potency (62.4%), followed by safety (42.4%), rapid onset (35.3%), adequate duration of efficacy (28.5%) and easy administration (25.9%). A total of 23 adverse events were observed in 18 patients, with the most frequent being hot flushes (3.2%), followed by headache (1.2%), nasal congestion (0.6%), color vision disturbance (0.3%), dizziness (0.3%), dry mouth (0.3%), dyspepsia (0.3%), nausea (0.3%) and diarrhea (0.3%). Only one patient discontinued vardenafil as a direct result of an adverse event. These results suggest that vardenafil prescribed by primary care physicians improved erectile function and was well tolerated by patients with ED.

The role of TST in the diagnosis of latent tuberculosis infection among military personnel in South Korea

BACKGROUND

The rapid and accurate diagnosis of latent tuberculosis infection (LTBI) is crucial in military settings because military personnel live in crowded circumstances and are of an age group with a high incidence of tuberculosis (TB). We tried to elucidate whether the tuberculin skin test (TST) accurately reflects the risk of TB infection among military personnel, in a setting of intermediate TB prevalence and where bacille Calmette-Guérin (BCG) vaccination is mandatory.

METHODS

A multi-stage cluster survey was conducted among military personnel in South Korea. Participants were grouped according to their risk of TB infection: Group 1, no identifiable risk of TB; Groups 2 and 3, recent casual (Group 2) or close (Group 3) contact with smear-positive TB patients.

RESULTS

Of 1045 participants, 857 (82.0%) had been BCG-vaccinated. The odds ratio (OR) of a positive TST (10 mm cut-off) for Group 2 (n = 184) and Group 3 (n = 83) compared with Group 1 (n = 778) were 0.95 (95%CI 0.67-1.38) and 1.7 (95%CI 1.06-2.70), respectively (P value for trend 0.16).

CONCLUSIONS

The TST does not accurately reflect the risk of LTBI among young military personnel in a setting where there is intermediate TB prevalence and extensive BCG coverage.

Nonlinear enhancement of femtosecond laser ablation efficiency by hybridization with nanosecond laser

Synchronization of femtosecond laser with nanosecond (~250 ns) laser results in a large enhancement in laser ablation efficiency of the Si wafer 12 times more than that with an independent laser exposure. Transient changes in the status of target material due to the proceeding nanosecond laser increase the femtosecond laser ablation efficiency.

Pulmonary tuberculosis in young Korean soldiers: incidence, drug resistance and treatment outcomes

OBJECTIVE

To determine the incidence and treatment outcomes of pulmonary tuberculosis (PTB) in young soldiers of South Korea.

DESIGN

From 2000 to 2004, all soldiers with a new diagnosis of tuberculosis (TB) were enrolled in the study, based on the official records of the Armed Forces Medical Command. The demographic and clinical data of the cases were evaluated retrospectively.

RESULTS

A total of 3115 TB cases were reported during the study period, of whom 2071 (66.5%) were reported as PTB. The annual incidence rates of PTB were 96.4 per 100,000 population in 2000, 89.3 in 2001, 67.6 in 2002, 60.2 in 2003, and 63.1 in 2004. A total of 270 patients diagnosed and treated at the Armed Forces Capital Hospital were analysed. Of the Mycobacterium tuberculosis isolates, 87.4% were susceptible to all available anti-tuberculosis drugs; 253 (93.7%) patients eventually completed initial anti-tuberculosis treatment. Among the patients with smear-positive PTB, the cure rate was 89.3% (100/112).

CONCLUSION

Our results demonstrate that the incidence of PTB in Korean soldiers, although still high, was declining steadily. With good case management, the overall success rate of initial treatment was approximately 90%.

Rare cases of Ménière's disease in children

Classical Ménière's disease is rarely found in children and literature regarding it is scarce. In general, the frequency of Ménière's disease in children is only 0.4-7.0 per cent of that in adults. The progression pattern of Ménière's disease in children is not known well. Here, we report three cases of Ménière's disease in children less than 15 years old, treated over nine years. The three cases comprise 14- and 13-year-old boys and a nine-year-old girl. Two of the three patients initially complained only of recurrent bouts of vertigo, without any tinnitus, ear fullness or hearing impairment. In all three cases, the early pure tone audiograms showed only high tone frequency loss, regardless of subjective hearing loss, and the decrease in the hearing threshold was observed one to eight years after the dizziness attacks began. The hearing threshold was usually decreased to a level of mild or moderate hearing impairment. After diuretic treatment, vertigo was generally well controlled, and some cases showed improvement in hearing. Of the total number of patients with Ménière's disease who visited our department over nine years, 2.6 per cent (3/114) were children, and the overall incidence of Ménière's disease in children with vertigo was 2.0 per cent (3/147). In conclusion, Ménière's disease in children rarely develops and may have characteristics of high tone loss in initial audiograms.

Spectral studies of SnO2 nanofibres prepared by electrospinning method

Tin oxide nanofibres with 100-150 nm diameter has been prepared, for the first time by calcination of poly(vinyl acetate) (PVAc)/SnO2 composite fibres prepared by electrospinning method as precursor. Scanning electron microscopic images revealed cylindrical morphology of the fibres after calcination at 600 degrees C. Both, X-ray diffraction (XRD) and Raman spectral data confirmed the presence of phase pure tetragonal rutile tin oxide after calcination process. Room temperature photoluminescence (PL) spectra of tin oxide nanofibres under excitation at 325 nm wavelength show a strong green emission at 525 nm with a band gap of 2.41 eV. FT-IR spectra confirmed the formation of pure tin oxide after calcination at 600 degrees C and complete removal of PVAc during calcination. UV-vis spectrum of the fibres showed absorption at 315 nm due to the direct electron transfer in tin oxide.

Detection of infectious haematopoietic necrosis virus and infectious salmon anaemia virus by molecular padlock amplification

A new method for the molecular detection of the fish pathogens, infectious haematopoietic necrosis virus (IHNV) and infectious salmon anaemia virus (ISAV), is described. By employing molecular padlock probe (MPP) technology combined with rolling circle amplification (RCA) and hyperbranching (Hbr), it is possible to detect RNA target sequence from these viruses at levels comparable with those detected by the polymerase chain reaction (PCR), but without prior reverse transcription. The use of MPP technology combined with RCA and Hbr for the detection of IHNV and ISAV in fish exhibited selectivity comparable with that of PCR while potentially reducing the time and cost required for analysis. The method described was used to detect as few as 10(4) DNA oligonucleotide targets and was sequence-specific at the single base level. Viral RNA could be detected directly, either alone or in the presence of non-viral RNA from fish tissue. This technology is applicable for detecting a variety of microbes, in addition to IHNV and ISAV, and is ideal for further integration into a biosensor platform for on-site diagnosis of pathogen infection in fish.

Hydrogen peroxide-producingLactobacilliin the vaginal flora of pregnant women with preterm labor with intact membranes

OBJECTIVES

To investigate the role of vaginal infection in preterm delivery, we studied characteristics of vaginal discharge related to hydrogen peroxide-producing Lactobacilli.

METHODS

Vaginal specimens were obtained from 66 women with normal pregnancy and 30 women with preterm labor with intact membranes. pH, leukocyte counts on wet smear, and scores by Nugent criteria on Gram stain were measured. Lactobacilli were tested for their production of hydrogen peroxide.

RESULTS

Leukocyte levels in wet smears and Nugent scores of Gram-stained smear of women with preterm labor with intact membranes were significantly higher than those of normal pregnant women (P<0.01, P<0.05). Hydrogen peroxide-producing Lactobacilli levels in the vaginal flora of women with preterm labor with intact membranes were significantly lower (P<0.01).

CONCLUSION

Distribution of hydrogen peroxide-producing Lactobacilli in vaginal flora as defense factors for infection may have an important role in the pathophysiology of preterm labor.

Pancreatic carcinoid tumor with obstructive pancreatitis: multislice helical CT appearance: case report

Carcinoid tumor of the pancreas is rare. Moreover, obstructive pancreatitis secondary to a pancreatic carcinoid tumor is extremely rare. We report a case of pancreatic carcinoid tumor in a 50-year-old male who presented with pancreatitis. On multislice helical computed tomography, the main pancreatic duct was obstructed by a small round tumor, and the main pancreatic duct proximal to the tumor was dilated. The correlation between the main pancreatic duct and the tumor was well depicted on minimum intensity projection image. This is the first report of multislice helical computed tomorgraphic and minimum intensity projection image findings of a pancreatic carcinoid tumor presenting with pancreatitis.

Concurrent chemoradiotherapy in patients with nasopharyngeal cancer: prognostic significance of low expression of bax

A randomized trial has demonstrated that concurrent chemoradiotherapy (CRT) is superior to radiotherapy (RT) alone in locally advanced nasopharyngeal cancer (NPC). Our study comprise 35 patients with locally advanced NPC (stage I: 1, II: 12, III: 7, IV: 15) with 1 cycle of induction chemotherapy (5-fluorouracil 1,000 mg/m(2)/day and cisplatin 20 mg/m(2)/day, days 1- 4) followed by concurrent CRT starting on day 22. Concurrent CRT consisted of RT (70 Gy/35 fractions for 7 weeks) with cisplatin 20 mg/m(2)/day for 4 days on weeks 1, 4, 7 of RT. Complete response (CR) was achieved in 33 patients (94%). Four-year progression-free survival (PFS) and overall survival (OS) of all patients were 57% and 65%, respectively. In analysis of prognostic factors, low expression of bax was the most significant independent predictor of poor prognosis in both PFS (p=0.002) and OS (p=0.008). In conclusion, the outcome of patients treated with this combined therapeutical modality appears to be comparable with that of Intergroup 0099 trial with high CR rate. Low expression of bax was significantly associated with poor PFS and OS.

Effects of arsenic on zebrafish innate immune system

The innate immune response, the first line of defense against invading pathogens, can be perturbed by environmental toxicants such as arsenic. This study reports the effects of arsenic on innate immunity of zebrafish. Respiratory burst activity, messenger RNA expression of tumor necrosis factor alpha (TNF-alpha), a primer of the respiratory burst response, and mRNA expression of the antiviral cytokines interferon (IFN) and MX, : before and after viral infection, were examined in arsenic-exposed zebrafish larvae. Respiratory burst activity and TNF-alpha expression were decreased upon arsenic exposure, indicating inhibition of TNF-alpha priming of the respiratory burst response. Arsenic enhanced IFN expression slightly over time, but reduced MX : expression. In zebrafish infected with snakehead rhabdovirus, arsenic decreased induction and altered the kinetics of IFN and MX : upon infection. Differences in IFN and MX : expression in arsenic-exposed larvae point toward an interruption of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway.

Morphology and kinetics studies on cephalosporin C production by Cephalosporium acremonium M25 in a 30-l bioreactor using a mixture of inocula

AIMS

In this study, the relationship between morphology and cephalosporin C (CPC) production in a 30-l bioreactor culture of Cephalosporium acremonium M25 using a 3:7 seed mixture was investigated. In addition, the kinetic model was established and applied.

METHODS AND RESULTS

CPC production was performed in a 30-l bioreactor using a 3:7 seed mixture. It was recognized that a 3:7 seed mixture was able to reduce lag phase and enhance CPC production. The maximum CPC production and cell mass were 1.96 and 81.5 g l-1 respectively. Through a morphology study by observation using image analysis, it was concluded that changes of morphological features predicted the progressive production of CPC and that a morphology study could be useful in monitoring the CPC fermentation by C. acremonium M25. In the kinetics study, a kinetic model of CPC fermentation was developed and applied. The proposed model could adequately describe the fermentation of C. acremonium M25 in a 30-l bioreactor.

CONCLUSIONS

CPC productivity was improved by using a 3:7 seed mixture in a 30-1 bioreactor. The changes in morphological features showed a very similar tendency with CPC production. A kinetic model of CPC fermentation was successfully established.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of the present study suggest that the use of a 3:7 seed mixture inocula has considerable possibilities for improving CPC productivity if applied to industrial scale fermentations. Through morphology and kinetics study, the kinetic model to describe the morphological differentiation and CPC production by C. acremonium M25 was established.

HMG-CoA reductase inhibition reverses LCAT and LDL receptor deficiencies and improves HDL in rats with chronic renal failure

Dyslipidemia is a prominent feature of chronic renal failure (CRF) and a major risk factor for atherosclerosis and the progression of renal disease. CRF-induced dyslipidemia is marked by hypertriglyceridemia and a shift in plasma cholesterol from HDL to the ApoB-containing lipoproteins. Several studies have demonstrated a favorable response to administration of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors (statins) in CRF. This study was intended to explore the effect of statin therapy on key enzymes and receptors involved in cholesterol metabolism. Accordingly, CRF ( nephrectomized) and sham-operated rats were randomized to untreated and statin-treated (rosuvastatin 20 mg·kg−1·day−1) groups and observed for 6 wk. The untreated CRF rats exhibited increased total cholesterol-to-HDL cholesterol ratio, diminished plasma lecithin:cholesterol acyltransferase (LCAT) and the hepatic LDL receptor, elevated hepatic acyl-CoA:cholesterol acyltransferase (ACAT), and no change in hepatic HMG-CoA reductase, cholesterol 7α-hydroxylase, or HDL receptor (SRB-1). Statin administration lowered HMG-CoA reductase activity, normalized plasma LCAT, total cholesterol-to-HDL cholesterol ratio, and hepatic LDL receptor but did not significantly change either plasma total cholesterol, hepatic cholesterol 7α-hydroxylase, total ACAT activity, or SRB-1 in the CRF animals. Statin administration to the normal control rats led to significant increases in plasma LCAT and hepatic LDL receptor, significant reductions of total cholesterol-to-HDL cholesterol ratio, hepatic HMG-CoA reductase activity, and cholesterol 7α-hydroxylase abundance with virtually no change in plasma cholesterol concentration. Thus administration of rosuvastatin reversed LCAT and LDL receptor deficiencies and promoted a shift in plasma cholesterol from ApoB-containing lipoproteins to HDL in CRF rats.

Molecular cloning of levan fructotransferase gene from Arthrobacter ureafaciens K2032 and its expression in Escherichia coli for the production of difructose dianhydride IV

AIMS

To clone and overexpress a novel levan fructotransferase gene lftA from Arthrobacter ureafaciens K2032.

METHODS AND RESULTS

The lftA gene, encoding a levan fructotransferase (LFTase) of 521 amino acids (aa) residues, was cloned from the genomic DNA of A. ureafaciens K2032, and overexpressed in Escherichia coli. The recombinant LFTase overexpressed in E. coli was then used to produce a difructose dianhydride (DFA IV) from levan. DFA IV crystals with 97% purity could be obtained from the reaction mixture in 83.7% yield by using a natural crystallization method.

CONCLUSIONS

The lftA gene cloned from A. ureafaciens K2032 encode a novel levan fructotransferase which produces difructose dianhydride (DFA IV) from levan.

SIGNIFICANCE AND IMPACT OF THE STUDY

Levan fructotransferase is a useful enzyme with great promise in the production of DFA IV and various fructosides.

Characterization of snakehead rhabdovirus infection in zebrafish (Danio rerio)

The zebrafish, Danio rerio, has become recognized as a valuable model for the study of development, genetics, and toxicology. Recently, the zebrafish has been recognized as a useful model for infectious disease and immunity. In this study, the pathogenesis and antiviral immune response of zebrafish to experimental snakehead rhabdovirus (SHRV) infection was characterized. Zebrafish 24 h postfertilization to 30 days postfertilization were susceptible to infection by immersion in 10(6) 50% tissue culture infective doses (TCID50) of SHRV/ml, and adult zebrafish were susceptible to infection by intraperitoneal (i.p.) injection of 10(5) TCID50 of SHRV/ml. Mortalities exceeded 40% in infected fish, and clinical presentation of infection included petechial hemorrhaging, redness of the abdomen, and erratic swim behavior. Virus reisolation and reverse transcription-PCR analysis of the viral nucleocapsid gene confirmed the presence of SHRV. Histological sections of moribund embryonic and juvenile fish revealed necrosis of the pharyngeal epithelium and liver, in addition to congestion of the swim bladder by cell debris. Histopathology in adult fish injected i.p. was confined to the site of injection. The antiviral response in zebrafish was monitored by quantitative real-time PCR analysis of zebrafish interferon (IFN) and Mx expression. IFN and Mx levels were elevated in zebrafish exposed to SHRV, although expression and intensity differed with age and route of infection. This study is the first to examine the pathogenesis of SHRV infection in zebrafish. Furthermore, this study is the first to describe experimental infection of zebrafish embryos with a viral pathogen, which will be important for future experiments involving targeted gene disruption and forward genetic screens.