Discovery of a gene cluster for the biosynthesis of novel cyclic peptide compound, KK-1, in Curvularia clavata

KK-1, a cyclic depsipeptide with 10 residues produced by a filamentous fungus Curvularia clavata BAUA-2787, is a promising pesticide active compound with high activity against many plant pathogens, especially Botrytis cinerea. As a first step toward the future mass production of KK-1 through synthetic biological approaches, we aimed to identify the genes responsible for the KK-1 biosynthesis. To achieve this, we conducted whole genome sequencing and transcriptome analysis of C. clavata BAUA-2787 to predict the KK-1 biosynthetic gene cluster. We then generated the overexpression and deletion mutants for each cluster gene using our originally developed transformation system for this fungus, and analyzed the KK-1 production and the cluster gene expression levels to confirm their involvement in KK-1 biosynthesis. As a result of these, a region of approximately 71 kb was found, containing 10 open reading frames, which were co-induced during KK-1 production, as a biosynthetic gene cluster. These include kk1B, which encodes nonribosomal peptide synthetase with a domain structure that is consistent with the structural features of KK-1, and kk1F, which encodes a transcription factor. The overexpression of kk1F increased the expression of the entire cluster genes and, consequently, improved KK-1 production, whereas its deletion decreased the expression of the entire cluster genes and almost eliminated KK-1 production, demonstrating that the protein encoded by kk1F regulates the expressions of the other nine cluster genes cooperatively as the pathway-specific transcription factor. Furthermore, the deletion of each cluster gene caused a reduction in KK-1 productivity, indicating that each gene is involved in KK-1 production. The genes kk1A, kk1D, kk1H, and kk1I, which showed a significant decrease in KK-1 productivity due to deletion, were presumed to be directly involved in KK-1 structure formation, including the biosynthesis of the constituent residues. kk1C, kk1E, kk1G, and kk1J, which maintained a certain level of KK-1 productivity despite deletion, were possibly involved in promoting or assisting KK-1 production, such as extracellular transportation and the removal of aberrant units incorporated into the peptide chain.

Downregulation of the ypdA Gene Encoding an Intermediate of His-Asp Phosphorelay Signaling in Aspergillus nidulans Induces the Same Cellular Effects as the Phenylpyrrole Fungicide Fludioxonil

Many eukaryotic histidine-to-aspartate (His-Asp) phosphorelay systems consist of three types of signal transducers: a His-kinase (HK), a response regulator (RR), and a histidine-containing phosphotransfer intermediate (HPt). In general, the HPt acts as an intermediate between the HK and the RR and is indispensable for inducing appropriate responses to environmental stresses. In a previous study, we attempted but were unable to obtain deletion mutants of the ypdA gene in order to characterize its function in the filamentous fungus Aspergillus nidulans. In the present study, we constructed the CypdA strain in which ypdA expression is conditionally regulated by the A. nidulans alcA promoter. We constructed CypdA strains with RR gene disruptions (CypdA-sskAΔ, CypdA-srrAΔ, and CypdA-sskAΔsrrAΔ). Suppression of YpdA induced by ypdA downregulation activated the downstream HogA mitogen-activated protein kinase cascade. YpdA suppression caused severe growth defects and abnormal hyphae, with features such as enhanced septation, a decrease in number of nuclei, nuclear fragmentation, and hypertrophy of vacuoles, both regulated in an SskA-dependent manner. Fludioxonil treatment caused the same cellular responses as ypdA suppression. The growth-inhibitory effects of fludioxonil and the lethality caused by ypdA downregulation may be caused by the same or similar mechanisms and to be dependent on both the SskA and SrrA pathways.

Ultrasonographic evaluation of the caudal vena cava in dogs with right-sided heart disease

INTRODUCTION/OBJECTIVES

In humans with impaired right-sided cardiac function, the caudal vena cava (CVC) diameter serves as a marker of venous congestion. This study aimed to investigate whether ultrasonographic CVC variables could identify the presence of right-sided congestive heart failure (R-CHF) in dogs with right-sided heart disease (RHD).

ANIMALS

Fifty client-owned control dogs and 67 dogs with RHD were enrolled. The dogs with RHD were subdivided into the non-R-CHF (n = 43) and R-CHF (n = 24) groups.

MATERIALS AND METHODS

We measured and compared the ultrasonographic CVC variables and echocardiographic variables among the groups. Receiver operating characteristic (ROC) curve analysis was performed to calculate the sensitivity and specificity of the variables at optimal cutoff values.

RESULTS

We obtained the highest accuracies of the ratio of the shortest diameter (SD) of the minimal CVC area to the aorta diameter (Ao) during inspiration [SD(min)/Ao] and of the ratio of SD(min) to the longest diameter of the minimal CVC area during inspiration [LD(min),SD/LD(min)], with high sensitivities, specificities, and an area under the ROC curve greater than 0.925.

CONCLUSIONS

In addition to the echocardiographic assessment of right-sided cardiac function, the CVC variables in this study, especially SD(min)/Ao and SD/LD(min), would be useful diagnostic indices for identifying R-CHF in dogs with RHD.

Million-year lag times in a post-orogenic sediment conveyor

Understanding how sediment transport and storage will delay, attenuate, and even erase the erosional signal of tectonic and climatic forcings has bearing on our ability to read and interpret the geologic record effectively. Here, we estimate sediment transit times in Australia's largest river system, the Murray-Darling basin, by measuring downstream changes in cosmogenic 26Al/10Be/14C ratios in modern river sediment. Results show that the sediments have experienced multiple episodes of burial and reexposure, with cumulative lag times exceeding 1 Ma in the downstream reaches of the Murray and Darling rivers. Combined with low sediment supply rates and old sediment blanketing the landscape, we posit that sediment recycling in the Murray-Darling is an important and ongoing process that will substantially delay and alter signals of external environmental forcing transmitted from the sediment's hinterland.

Attenuated relationship between salivary oxytocin levels and attention to social information in adolescents and adults with autism spectrum disorder: a comparative study

BACKGROUND

Previous research studies have assessed the relationship between attention to social information and peripheral (e.g., plasma and salivary) oxytocin (OT) levels in typically developing (TD) children and children with autism spectrum disorder (ASD). A relationship between them was observed in TD children, but not in children with ASD. However, this relationship remains unexamined in other age groups. To clarify whether this lack of association is maintained throughout development in individuals with ASD, we aimed to assess the relationship between salivary OT levels and attention to social information in adolescents and adults with and without ASD.

METHODS

We recruited male adolescents and adults with ASD (n = 17) and TD participants (n = 24). Using the all-in-one eye-tracking system Gazefinder, we measured the percentage fixation time allocated to social information. We also measured the salivary OT levels and Autism Spectrum Quotient (AQ) of participants. Subsequently, we confirmed group differences and conducted a correlation analysis to investigate the relationships between these three measures.

RESULTS

Salivary OT levels did not show any significant difference between the ASD and TD groups and were negatively correlated with the AQ in the whole-group analysis, but not in within-group analysis. Individuals with ASD had significantly lower percentage fixation times than did TD individuals for eye regions in human faces with/without mouth motion, for upright biological motion, and for people regions in the people and geometry movies. The percentage of fixation for geometric shapes in the people and geometry movies was significantly higher in the ASD than in the TD group. In the TD group, salivary OT levels were positively correlated with percentage fixation times for upright biological motion and people and negatively correlated with inverted biological motion and geometry. However, no significant correlations were found in the ASD group.

CONCLUSIONS

Our exploratory results suggest that salivary OT levels in adolescents and adults with ASD are less indicative of attention to social stimuli than they are in TD adolescents and adults. It is suggested that their association is slightly weaker in adolescents and adults with ASD and that this attenuated relationship appears to be maintained throughout development.

1159 Right ventricular electromechanical dyssynchrony in relation to right ventricular remodeling, dysfunction and exercise capacity in Ebstein anomaly

Background

Abnormal atrioventricular conduction and functional right ventricular (fRV) dysfunction are common in patients with Ebstein anomaly (EA). However, the relation of fRV dyssynchrony to fRV function in EA has not been studied.

Purpose

We hypothesized that fRV electromechanical dyssynchrony is associated with fRV remodeling, dysfunction and exercise intolerance in EA patients.

Methods

Non-operated EA patients and age-matched controls prospectively underwent echocardiography, cardiovascular magnetic resonance imaging (CMR) and cardiopulmonary exercise testing to quantify RV remodeling, dysfunction and exercise capacity, respectively. The relation of these to fRV dyssynchrony was investigated. RV mechanical dyssynchrony was defined by early septal activation (right-sided septal flash), RV lateral wall prestretch/late contraction, postsystolic shortening, and the maximal intra-RV delay (difference in time to peak of lateral basal RV and apical septal segments) using 2-dimensional strain echocardiography.

Results

Thirty-five EA patients (age 31.6 ± 17.3 years, 19 female) and 35 age-matched controls were studied. QRS duration and intra-fRV mechanical delay were significantly longer in EA compared with controls. 19/35(54%) of EA patients had early activation of septal segments with simultaneous stretching and consequent late activation and post-systolic shortening of RV lateral segments. QRS duration correlated with fRV end-diastolic (fRVEDVI, r = 0.46, P <0.01) and end-systolic indexed volumes (fRVESVIr = 0.57, P <0.001). Intra-fRV delay correlated with RV global longitudinal strain (GLS, r=-0.45,P <0.05) and RV fractional area change (r=-0.56, P <0.01). Intra-fRV delay was also associated with fRVEDVI (r = 0.43, P <0.05), fRVESVI (r = 0.63, P <0.001), fRVEF (r=-0.46,P <0.05) and predicted peak VO2 (r=-0.39, P < 0.05). EA patients with versus without a septal flash had lower fRVEF (45 ± 11 vs. 54 ± 8%, p < 0.05) and predicted peak VO2 (0.71 ± 0.19 vs. 0.92 ± 0.33, p < 0.05).

Conclusions

In EA, fRV electromechanical dyssynchrony is associated with fRV remodeling, dysfunction and impaired exercise capacity and may constitute a therapeutic target.

Abstract 1159 Figure.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

Heterologous Production of a Novel Cyclic Peptide Compound, KK-1, in Aspergillus oryzae

A novel cyclic peptide compound, KK-1, was originally isolated from the plant-pathogenic fungus Curvularia clavata. It consists of 10 amino acid residues, including five N-methylated amino acid residues, and has potent antifungal activity. Recently, the genome-sequencing analysis of C. clavata was completed, and the biosynthetic genes involved in KK-1 production were predicted by using a novel gene cluster mining tool, MIDDAS-M. These genes form an approximately 75-kb cluster, which includes nine open reading frames, containing a non-ribosomal peptide synthetase (NRPS) gene. To determine whether the predicted genes were responsible for the biosynthesis of KK-1, we performed heterologous production of KK-1 in Aspergillus oryzae by introduction of the cluster genes into the genome of A. oryzae. The NRPS gene was split in two fragments and then reconstructed in the A. oryzae genome, because the gene was quite large (approximately 40 kb). The remaining seven genes in the cluster, excluding the regulatory gene kkR, were simultaneously introduced into the strain of A. oryzae in which NRPS had already been incorporated. To evaluate the heterologous production of KK-1 in A. oryzae, gene expression was analyzed by RT-PCR and KK-1 productivity was quantified by HPLC. KK-1 was produced in variable quantities by a number of transformed strains, along with expression of the cluster genes. The amount of KK-1 produced by the strain with the greatest expression of all genes was lower than that produced by the original producer, C. clavata. Therefore, expression of the cluster genes is necessary and sufficient for the heterologous production of KK-1 in A. oryzae, although there may be unknown factors limiting productivity in this species.

Stiripentol for the treatment of super-refractory status epilepticus with cross-sensitivity

BACKGROUND

Cross-sensitivity of rash has been reported between various antiepileptic drugs (AEDs). However, few studies have determined the frequency and management of cross-sensitivity in patients with super-refractory status epilepticus (SRSE).

AIMS OF THE STUDY

To examine the optimal AED for treating SRSE with cross-sensitivity.

METHODS

We performed a retrospective review of adult patients with SRSE treated at Nagoya City University Hospital, in which we investigated the frequency of cross-sensitivity among patients with SRSE and their clinical and medical profiles.

RESULTS

We identified 10 adult patients with SRSE, 5 of whom had cross-sensitivity. Stiripentol (STP) was administered when previously used AEDs had demonstrated cross-sensitivity and failed to control seizures. After initiation of STP, the dose of general anaesthetics was reduced, and status epilepticus (SE) eventually ceased with co-administered AEDs without additional adverse effects. The mean time to SE cessation after initiation of STP was 30.8 days (range, 18-46 days), mean duration of general anaesthesia was 101.2 days (range, 74-128 days), and mean number of AEDs was 9.0 (range, 6-11).

CONCLUSIONS

This study suggests that cross-sensitivity between AEDs is common in adults with SRSE and that STP may be useful for treating SRSE with cross-sensitivity.

Oxytocin efficacy is modulated by dosage and oxytocin receptor genotype in young adults with high-functioning autism: a 24-week randomized clinical trial

Recent studies have suggested that long-term oxytocin administration can alleviate the symptoms of autism spectrum disorder (ASD); however, factors influencing its efficacy are still unclear. We conducted a single-center phase 2, pilot, randomized, double-blind, placebo-controlled, parallel-group, clinical trial in young adults with high-functioning ASD, to determine whether oxytocin dosage and genetic background of the oxytocin receptor affects oxytocin efficacy. This trial consisted of double-blind (12 weeks), open-label (12 weeks) and follow-up phases (8 weeks). To examine dose dependency, 60 participants were randomly assigned to high-dose (32 IU per day) or low-dose intranasal oxytocin (16 IU per day), or placebo groups during the double-blind phase. Next, we measured single-nucleotide polymorphisms (SNPs) in the oxytocin receptor gene (OXTR). In the intention-to-treat population, no outcomes were improved after oxytocin administration. However, in male participants, Clinical Global Impression-Improvement (CGI-I) scores in the high-dose group, but not the low-dose group, were significantly higher than in the placebo group. Furthermore, we examined whether oxytocin efficacy, reflected in the CGI-I scores, is influenced by estimated daily dosage and OXTR polymorphisms in male participants. We found that >21 IU per day oxytocin was more effective than ⩽21 IU per day, and that a SNP in OXTR (rs6791619) predicted CGI-I scores for ⩽21 IU per day oxytocin treatment. No severe adverse events occurred. These results suggest that efficacy of long-term oxytocin administration in young men with high-functioning ASD depends on the oxytocin dosage and genetic background of the oxytocin receptor, which contributes to the effectiveness of oxytocin treatment of ASD.

Mitogen-activated protein kinases MpkA and MpkB independently affect micafungin sensitivity in Aspergillus nidulans

The transcriptional regulation of the MAPK mpkA and cell wall-related genes in Aspergillus nidulans differs from that of their counterparts in Saccharomyces cerevisiae. The A. nidulans MAPK MpkB is putatively orthologous to the yeast MAPKs Kss1p and Fus3p. To investigate MpkB and its contribution to cell wall integrity in A. nidulans, we constructed mpkB-disruptant (mpkB∆) strains. We previously showed that mpkA∆ strains exhibited reduced colony growth and increased sensitivity to the β-1,3-glucan synthase inhibitor micafungin. Like mpkA∆ strains, mpkB∆ strains exhibited slight growth retardation and increased sensitivity to micafungin. Although MpkB-dependent signaling modulated the transcription of some cell wall-related genes, the sugar composition of cell wall fractions was similar among wild-type, mpkA∆, and mpkB∆ strains. To elucidate the relationship between MpkA and MpkB pathways, we compared conditional mutants of mpkB with those with mpkA deletion. Sensitivity testing suggested that MpkA and MpkB additively contribute to micafungin activity in A. nidulans.

CD133 is a positive marker for a distinct class of primitive human cord blood-derived CD34-negative hematopoietic stem cells

The identification of human CD34-negative (CD34(-)) hematopoietic stem cells (HSCs) provides a new concept for the hierarchy in the human HSC compartment. Previous studies demonstrated that CD34(-) severe combined immunodeficiency (SCID)-repopulating cells (SRCs) are a distinct class of primitive HSCs in comparison to the well-characterized CD34(+)CD38(-) SRCs. However, the purification level of rare CD34(-) SRCs in 18 lineage marker-negative (Lin(-)) CD34(-) cells (1/1000) is still very low compared with that of CD34(+)CD38(-) SRCs (1/40). As in the mouse, it will be necessary to identify useful positive markers for a high degree of purification of rare human CD34(-) SRCs. Using 18Lin(-)CD34(-) cells, we analyzed the expression of candidate positive markers by flow cytometric analysis. We finally identified CD133 as a reliable positive marker of human CB-derived CD34(-) SRCs and succeeded in highly purifying primitive human CD34(-) HSCs. The limiting dilution analysis demonstrated that the incidence of CD34(-) SRCs in 18Lin(-)CD34(-)CD133(+) cells was 1/142, which is the highest level of purification of these unique CD34(-) HSCs to date. Furthermore, CD133 expression clearly segregated the SRC activities of 18Lin(-)CD34(-) cells, as well as 18Lin(-)CD34(+) cells, in their positive fractions, indicating its functional significance as a common cell surface maker to isolate effectively both CD34(+) and CD34(-) SRCs.

Embryonal rhabdomyosarcoma of the uterus in a 35-year-old woman: case report and review of the literature

Embryonal rhabdomyosarcoma (RMS) is a rare sarcoma that characteristically occurs in children. The current treatment protocols are based on trials performed in patients under 21 years of age. Embryonal RMS in women over 20 years of age is rare, and studies on treatments and outcomes are limited. The authors here in report a case of a 35-year-old woman with ectocervical RMS who was treated with radical hysterectomy followed by chemotherapy. She is currently disease-free. Based on a literature review, the authors recommend a surgical approach in combination with chemotherapy for treatment of embryonal RMS in adult patients.

Introduction to The neurosciences and music IV: learning and memory

The conference entitled "The Neurosciences and Music-IV: Learning and Memory'' was held at the University of Edinburgh from June 9-12, 2011, jointly hosted by the Mariani Foundation and the Institute for Music in Human and Social Development, and involving nearly 500 international delegates. Two opening workshops, three large and vibrant poster sessions, and nine invited symposia introduced a diverse range of recent research findings and discussed current research directions. Here, the proceedings are introduced by the workshop and symposia leaders on topics including working with children, rhythm perception, language processing, cultural learning, memory, musical imagery, neural plasticity, stroke rehabilitation, autism, and amusia. The rich diversity of the interdisciplinary research presented suggests that the future of music neuroscience looks both exciting and promising, and that important implications for music rehabilitation and therapy are being discovered.

Fabry Disease Presenting with Multiple Hemorrhagic Cerebral Infarction

We describe a 57-year-old woman, a heterozygote for Fabry disease who had multiple hemorrhagic cerebral infarctions. Her clinical course and radiological findings suggested cardiogenic cerebral embolus, but distinction from multiple cerebral infarction associated with Fabry disease seemed necessary. Our present case is reported with reference to the literature to introduce various types of stroke, which can develop in patients with Fabry disease.

Using fallout plutonium as a probe for erosion assessment

A study has been carried out to assess the potential of using fallout plutonium (Pu), which originated from atmospheric nuclear-weapons tests, as a tool to investigate recent erosional processes within the lower Cotter water-supply catchment in the Australian Capital Territory. This catchment, which was predominantly pine plantation, was severely affected by a major bush fire in 2003. Accelerator mass spectrometry has been used to measure Pu in soil samples collected from a number of sites across the catchment. The results indicate that less than 1cm of surface soil had been lost since the early 1960s over much of the catchment. Areas of more erodible soil have, however, lost 2-4cm of topsoil, and a loss of ∼6cm of soil was identified at one particular site.

Study of the prediction system for clinical response to M-VAC neoadjuvant chemotherapy for bladder cancer

Neoadjuvant chemotherapy for invasive bladder cancer, involving a regimen of M-VAC, can manage micrometastasis and improve the prognosis. However, some patients suffer from severe adverse drug reactions without any effect, and no method yet exists for predicting the response of an individual patient to chemotherapy. Our purpose in this study is to establish a method for predicting the response to the M-VAC therapy. We analyzed gene-expression profiles of biopsy materials from 40 invasive bladder cancers using a cDNA microarray consisting of 27 648 genes, after populations of cancer cells had been purified by laser-microbeam microdissection. We identified 14 predictive genes that were expressed differently between nine responder and nine non-responder tumors and devised a prediction-scoring system that clearly separated the responder group from the non-responder group. This system accurately predicted the clinical response for 19 of the 22 additional test cases. The group of patients with positive predictive scores had significantly longer survival times than that with negative scores. As real-time RT-PCR data were highly concordant with the cDNA microarray data for those 14 genes, we developed a quantitative RT-PCR-based prediction system that could be feasible for routine clinical use. Taken together, our results suggest that the sensitivity of an invasive bladder cancer to the M-VAC neoadjuvant chemotherapy can be predicted by expression patterns in this set of genes, a step toward achievement of "personalized therapy" for treatment of this disease.

Helicobacter pylori dupA gene is not associated with clinical outcomes in the Japanese population

The dupA gene of Helicobacter pylori was suggested to be a risk factor for duodenal ulcer but protective against gastric cancer. The present study aimed to re-examine the role of dupA in H. pylori-infected Japanese patients. We found that dupA status was not associated with any gastroduodenal disease, histological score of chronic gastritis or with the extent of interleukin-8 production from gastric cell lines. These results indicate that dupA is unlikely to be a virulence factor of H. pylori in the Japanese population.

Helicobacter pylori dupA gene is not associated with clinical outcomes in the Japanese population

The dupA gene of Helicobacter pylori was suggested to be a risk factor for duodenal ulcer but protective against gastric cancer. The present study aimed to re-examine the role of dupA in H. pylori-infected Japanese patients. We found that dupA status was not associated with any gastroduodenal disease, histological score of chronic gastritis or with the extent of interleukin-8 production from gastric cell lines. These results indicate that dupA is unlikely to be a virulence factor of H. pylori in the Japanese population.

Endothelial dysfunction and decreased exercise tolerance in interferon-alpha therapy in chronic hepatitis C: relation between exercise hyperemia and endothelial function

BACKGROUND

We previously reported that reversible endothelial dysfunction is caused by interferon-alpha therapy (IFN) in patients with chronic hepatitis C. In experimental studies, limb blood flow during exercise is reported to be dependent on endothelium-derived nitric oxide.

HYPOTHESIS

The purpose of this study was to confirm the effect of IFN on endothelial function and to investigate whether exercise hyperemia is dependent on endothelial function in humans.

METHODS

We performed symptom-limited exercise treadmill testing and measured flow-mediated vasodilation (FMD, endothelium-dependent vasodilation) and sublingual glyceryl-trinitrate-induced dilation (GTN-D, 0.3 mg, endothelium-independent vasodilation) in the brachial artery by using high-resolution ultrasound in 10 patients with chronic active hepatitis C (age 53 +/- 11 years, 2 men, 8 women) before and immediately after administration of recombinant interferon 2b (10 million U/day) for 4 weeks.

RESULTS

There were no significant abnormal findings in any patients in routine studies of 24-h ambulatory electrocardiogram monitoring, two-dimensional echocardiography, and exercise treadmill testing both before and after treatment. Leg fatigue and exhaustion were the reasons for termination of exercise treadmill testing in each patient. Pressure rate product was calculated at rest and peak exercise. Interferon-alpha therapy significantly (p<0.05) decreased FMD (6.8 +/- 3.1 vs. 1.9 +/- 2.6%), exercise treadmill testing tolerance time (437 +/- 89 vs. 395 +/- 62 s) and peak pressure rate product (283 +/- 41 vs. 241 +/- 47 mmHg x beats/min x 10(-2)), but not GTN-D (13.4 +/- 5.4 vs. 17.0 +/- 5.5%). The change of FMD due to IFN significantly and highly correlated with exercise treadmill testing tolerance time (r = 0.86, p<0.001), but not with change of peak pressure rate product, suggesting that FMD is more closely related to the condition of the peripheral circulation than is cardiac performance.

CONCLUSION

These results suggest that IFN in patients with chronic hepatitis C impairs endothelial function and exercise tolerance, and that endothelial function might be at least partly involved in exercise hyperemia in humans.

Genome-wide analysis of DNA copy number alterations and gene expression in gastric cancer

Genomic copy number aberrations (CNAs) are believed to play a major role in the development and progression of human cancers. Although many CNAs have been reported in gastric cancer, their genome-wide transcriptional consequences are poorly understood. In this study, to reveal the impact of CNAs on genome-wide expression in gastric cancer, we analysed 30 cases of gastric cancers for their CNAs by array comparative genomic hybridization (array CGH) and 24 of these 30 cases for their expression profiles by oligonucleotide-expression microarray. We found that with the application of laser microdissection, most CNAs were detected at higher frequency than in previous studies. Notably, gain at 20q13 was detected in almost all cases (97%), suggesting that this may play an important role in the pathogenesis of gastric cancer. By comparing the array CGH data with expression profiles of the same samples, we showed that both genomic amplification and deletion strongly influence the expression of genes in altered genomic regions. Furthermore, we identified 125 candidate genes, consisting of 114 up-regulated genes located in recurrent regions (>10%) of amplification and 11 down-regulated genes located in recurrent regions of deletion. Up-regulation of several candidate genes, such as CDC6, SEC61G, ANP32E, BYSL and FDFT1, was confirmed by immunohistochemistry. Interestingly, some candidate genes were localized at genomic loci adjacent to well-known genes such as EGFR, ERBB2 and SMAD4, and concordantly deregulated by genomic alterations. Based on these results, we propose that our list of candidate genes may contain novel genes involved in the pathogenesis of advanced gastric cancer.

Functional analysis of C2H2 zinc finger transcription factor CrzA involved in calcium signaling in Aspergillus nidulans

Calcium signaling systems are widely employed in eukaryotes and are implicated in the regulation of diverse biological processes. Calcineurin is an important signaling component, which mediates ion homeostasis and virulence in several fungi. Based on intensive studies conducted on budding yeast, transcription factor Crz1p is thought to be a target of calcineurin. To provide insight into calcium signaling, a Crz1p homolog (CrzA) in a filamentous fungus Aspergillus nidulans was identified and its function with special reference to calcium response was characterized. A crzA gene disruption mutant exhibited sensitivity to high concentrations of Mn(2+) and Ca(2+), and mediated the expression of P-type calcium-ATPase homologous genes. Comprehensive transcriptional analysis with DNA microarrays indicated that CrzA regulates the expression of a vacuolar Ca(2+)/H(+) exchanger gene in response to external calcium stimuli. It is suggested that the calcineurin-CrzA pathway is the mediator of Ca(2+) homeostasis in A. nidulans. Moreover, a crzA/hogA double mutant showed hypersensitivity to osmotic stress, indicating the importance of calcium homeostasis for adaptation to osmotic stress, a universal stress in filamentous fungi.

Temperature-dependent sex determination in Hd-rR medaka Oryzias latipes: gender sensitivity, thermal threshold, critical period, and DMRT1 expression profile

The developmental time and thermal threshold for temperature-dependent sex determination (TSD), gender differences in temperature sensitivity, the fertility of thermally sex reversed fish, and the effect of temperature on the expression of two major sex determination/differentiation genes (DMY/DMRT1bY and DMRT1) were examined in the Hd-rR strain of medaka, Oryzias latipes. Fertilized eggs were exposed from either shortly after fertilization (8-16 cells; embryonic stages 5-6) or from middle embryogenesis (heart development stage; stage 36) until hatching to temperatures ranging from 17 degrees C to 34 degrees C. Secondary sexual characteristics, gonadal histology, progeny testing, sex-linked body coloration and gene expression were used to determine phenotypic and genotypic sex. Sex determination was unaffected by low or high temperatures in genotypic (XY) males. In contrast, genotypic (XX) females treated from stages 5-6 showed increasing rates of sex reversal into phenotypic males at temperatures above 27 degrees C up to 100% at 34 degrees C. Thermal manipulation of sex was ineffective after stage 36, indicating that gonadal fate in medaka is determined considerably earlier than histological differentiation (stage 39). High temperature induced DMRT1 expression in genotypic females, which was observed already from stage 36. Sex-reversed males had histologically normal testes, were capable of sexual courtship and, with the exception of fish from 34 degrees C, sired viable progeny when mating with fertile females. These results clarify the pattern of TSD in medaka and provide important clues to understand the mechanism of sex determination in this species. They also suggest that a brief exposure to high temperature early in life could impair the fertility of medaka as adults.

Novel reporter gene expression systems for monitoring activation of the Aspergillus nidulans HOG pathway

The Aspergillus nidulans high-osmolarity glycerol response (AnHOG) pathway is involved in osmoadaptation. We found that fludioxonil, a fungicide, causes improper activation of HogA mitogen-activated protein kinase (MAPK) in A. nidulans. Here we present novel reporter systems for monitoring activation of the AnHOG pathway. The promoter region of gfdB (glycerol-3-phosphate dehydrogenase), whose expression depends on the presence of HogA, was fused to a beta-glucuronidase uidA gene (GUS) to construct the reporter, which was introduced into A. nidulans wild type and hogADelta. Increased GUS activity was detected in the wild type only when it was treated with high osmolarity or fludioxonil, while reporter activity was scarcely stimulated in the hogADelta mutant. These results indicate that the reporter activity is controlled via HogA activation. Furthermore, we present possible applications of the reporter systems in screening new antifungal compounds.

MpkA-Dependent and -independent cell wall integrity signaling in Aspergillus nidulans

Cell wall integrity signaling (CWIS) maintains cell wall biogenesis in fungi, but only a few transcription factors (TFs) and target genes downstream of the CWIS cascade in filamentous fungi are known. Because a mitogen-activated protein kinase (MpkA) is a key CWIS enzyme, the transcriptional regulation of mpkA and of cell wall-related genes (CWGs) is important in cell wall biogenesis. We cloned Aspergillus nidulans mpkA; rlmA, a TF gene orthologous to Saccharomyces cerevisiae RLM1 that encodes Rlm1p, a major Mpk1p-dependent TF that regulates the transcription of MPK1 besides that of CWGs; and Answi4 and Answi6, homologous to S. cerevisiae SWI4 and SWI6, encoding the Mpk1p-activating TF complex Swi4p-Swi6p, which regulates CWG transcription in a cell cycle-dependent manner. A. nidulans rlmA and mpkA cDNA functionally complemented S. cerevisiae rlm1Delta and mpk1Delta mutants, respectively, but Answi4 and Answi6 cDNA did not complement swi4Delta and swi6Delta mutants. We constructed A. nidulans rlmA, Answi4 and Answi6, and mpkA disruptants (rlmADelta, Answi4Delta Answi6Delta, and mpkADelta strains) and analyzed mpkA and CWG transcripts after treatment with a beta-1,3-glucan synthase inhibitor (micafungin) that could activate MpkA via CWIS. Levels of mpkA transcripts in the mutants as well as those in the wild type were changed after micafungin treatment. The beta-glucuronidase reporter gene controlled by the mpkA promoter was expressed in the wild type but not in the mpkADelta strain. Thus, mpkA transcription seems to be autoregulated by CWIS via MpkA but not by RlmA or AnSwi4-AnSwi6. The transcription of most CWGs except alpha-1,3-glucan synthase genes (agsA and agsB) was independent of RlmA and AnSwi4-AnSwi6 and seemed to be regulated by non-MpkA signaling. The transcriptional regulation of mpkA and of CWGs via CWIS in A. nidulans differs significantly from that in S. cerevisiae.