Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

Efficacy of a formalin-inactivated Lactococcus garvieae vaccine in farmed grey mullet (Mugil cephalus)

Lactococcosis [Lactococcus garvieae (LG)] is one of the most prevalent bacterial diseases affecting grey mullet (Mugil cephalus) aquaculture. Therefore, the present research evaluated the efficacy of formalin-killed LG vaccine with an oil-based adjuvant in grey mullet under laboratory and field trials. The laboratory evaluation for LG vaccine and its cross-protection upon challenge in grey mullet found that single-dose immunization of formalin-killed LG with adjuvant resulted in 91.4% and 100% relative per cent survival (RPS) when challenged with homologous and heterologous strains. The levels of specific antibody titre and lysozyme activity increased significantly in the vaccinated group. Immune gene expression at 24 hr after challenge showed an increase in levels of pro-inflammatory and anti-inflammatory cytokines. A parallel field trial experiment was conducted to investigate the long-term effectiveness of the LG vaccine. Results demonstrated that at one month and three months post-immunization with heterologous strain, 100% RPS was recorded in the vaccinated group. The findings suggested that the formalin-inactivated LG vaccine strain (S3) protected grey mullet against LG infection for a period of three months.

Paclitaxel inhibits the progression of cervical cancer by inhibiting autophagy via lncRNARP11-381N20.2

OBJECTIVE

To observe the effect of paclitaxel on the autophagy of human cervical cancer cell lines by the expression regulation of lncRNARP11-381N20.2 as well as to explore the interaction and relationship between autophagy, proliferation, and apoptosis of cervical cancer cells.

MATERIALS AND METHODS

Genome-wide expression profiles of tumors and their susceptibility to drugs were downloaded through TCGA database to find differentially expressed lncRNA RP11-381N20.2 in chemosensitive sensitive and insensitive groups. Expression of RP11-381N20.2 in 60 cervical cancer tissues and 30 normal tissues was detected by qRT-PCR. The relationship between the expression of RP11-381N20.2 and the clinicopathological parameters of lung cancer was statistically analyzed. The recombinant plasmid pcDNA-RP11-381N20.2 and pcDNA-NC of RP11-381N20.2 were transfected into SiHa cells by lipofectamine, respectively. The autophagy and phenotypic effects were observed. Cell proliferation was determined by colony formation assay. Apoptosis was detected by flow cytometry. Western blot was conducted to detect expressions of autophagy-related proteins.

RESULTS

Genome-wide expression profiles of chemotherapy-sensitive and insensitive data in patients with cervical cancer in TCGA database were analyzed by edger package, results showed that the expression of lncRNA RP11-381N20.2 was significantly lower in the chemotherapy-insensitive group. qRT-PCR results showed that the expression of RP11-381N20.2 in cervical cancer was decreased, and the total survival time of patients was positively correlated with the expression of RP11-381N20.2. RP11-381N20.2 was associated with TNM (tumor node metastasis) staging and tumor size. Biological functions of SiHa cells showed that the expression of RP11-381N20.2 was negatively correlated with the treatment time and dose of paclitaxel. Colony formation assay showed that paclitaxel could inhibit the proliferation of cervical cancer cells in a dose-dependent manner. Flow cytometry showed that paclitaxel induced apoptosis of cervical cancer cells, which was more promoted after combination with RP11-381N20.2. Western blot results suggested that paclitaxel could induce autophagy in cervical cancer cells in a time- and dose-dependent manners. Paclitaxel combined with RP11-381N20.2 could significantly increase apoptosis of cervical cancer cells.

CONCLUSIONS

During the killing process of paclitaxel on cervical cancer SiHa cells, cell autophagy would affect the efficacy, after overexpression of RP11-381N20.2 in SiHa cells, autophagy induced by paclitaxel was inhibited, thereby enhancing the killing effect of paclitaxel on tumor cells.

Effect of lutein and doxorubicin combinatorial therapy on S180 cell proliferation and tumor growth

OBJECTIVE

Multidrug resistance and toxicity significantly compromise the therapeutic efficacy for sarcomas. We aimed at evaluating the effect of lutein-doxorubicin (DOX) combinatorial therapy on inhibiting S180 (Sarcoma 180) cell proliferation and tumor growth.

MATERIALS AND METHODS

S180 cells in logarithmic growth phase were treated with lutein, DOX, or lutein-DOX combinatorial therapy for 48 h. The cell survival rate was determined by MTT assay. Apoptosis was detected by flow cytometry. The expression of PCNA, P53, and NF-κB was assessed by Western blot. Further, mice bearing S180 tumors received lutein, DOX, or lutein-DOX combinatorial therapy by oral gavage.

RESULTS

Lutein-DOX combinatorial therapy significantly decreased the proliferation of S180 cells (p<0.01) in vitro. Also, the expression of proliferating cell nuclear antigen (PCNA) (p<0.05) and the apoptosis-relevant gene p53 were decreased, which resulted in increased cell apoptosis (p<0.05). The level of nuclear factor kappa B (NF-κB) was also decreased by the combinatorial therapy. Lutein-DOX combinatorial therapy reduced the cytotoxicity of DOX and reduced the inflammatory response. The inhibitory effect of lutein-DOX combinatorial therapy on cell proliferation was confirmed in vivo. The growth rate and size of the tumor at 30 d after treatment were significantly lower than those of the control group and DOX single therapy.

CONCLUSIONS

Lutein and DOX synergistically inhibit sarcoma cell proliferation and tumor growth. This novel therapeutic regimen could potentially improve clinical outcome of sarcoma patients.

MicroRNA-574 enhances doxorubicin resistance through down-regulating SMAD4 in breast cancer cells

OBJECTIVE

Drug resistance has become an important factor that threatens the survival and prognosis of patients with breast cancer, especially in patients with advanced breast cancer. Several microRNAs have been proved to participate in the resistant process; however, the role of miR-574 in doxorubicin (Dox) resistant breast cancer is still unclear.

PATIENTS AND METHODS

Quantitative Real-time poly chain reaction (qRT-PCR) was employed to detect the expression level of miR-574 in breast cancer Dox-resistant MCF-7/Adr cell line and parental MCF-7 cell line. Using miR-574 mimics and inhibitors, miR-574 level was up- or down- regulated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was handled to detect the IC50, and flow cytometric analysis was employed to measure the apoptosis and cell circle. Dual-luciferase and Western-blot experiments were applied to verify the direct target gene of miR-574.

RESULTS

miR-574 expression level was significantly higher in MCF-7/Adr cells compared to normal MCF-7 cells. Up-regulation of miR-574 level in MCF-7 cells promoted the cell growth and G0/G1-to-S phase transition but inhibited cell apoptosis. However, knockdown of miR-574 in MCF-7/Adr cells decreased the IC50 and cell growth. Using luciferase assay, SMAD4 was confirmed to be a potential target of miR-574, and the expression of SMAD4 protein was regulated by miR-574. In blood samples of patients, the miR-574 level before chemotherapy was higher than that after chemotherapy.

CONCLUSIONS

We revealed miR-574 could promote doxorubicin resistance of breast cancer MCF-7 cells via down-regulating SMAD4, thus providing a novel target for advancing breast cancer chemotherapy.

Cisplatin suppresses tumor proliferation by inhibiting autophagy in ovarian cancer via long non-coding RNA RP11-135L22.1

OBJECTIVE

To observe the effect of cisplatin-induced autophagy in human ovarian cancer cell lines and explore the correlation between RP11-135L22.1 with cisplatin-induced autophagy.

MATERIALS AND METHODS

Genome-wide expression profile and chemotherapy sensitivity data of ovarian cancer were downloaded from TCGA database. It was found that the expression level of lncRNA RP11-135L22.1 differed between chemotherapy-sensitive group and insensitive group. Besides, RP11-135L22.1 expression levels were detected in 64 ovarian cancer tissues and 30 normal tissues by qRT-PCR. Relationship between RP11-135L22.1 expression levels in 64 ovarian cancer tissues and their clinicopathological characteristics were analyzed by x2-test. Cell viability was detected by CCK8 assay. Cell apoptosis and cell cycle were accessed by flow cytometry. HO8910 cells were selected for transfection of pcDNA-RP11-135L22.1, and qRT-PCR was used to evaluate RP11-135L22.1 expression in cisplatin-treated HO8910 cells. Western blot was performed to analyze the expression changes of autophagy-related proteins.

RESULTS

Genome-wide expression profile of chemotherapy-sensitive and -insensitive patients with ovarian cancer from TCGA database was analyzed by edger package. It was found that RP11-135L22.1 level in chemotherapy-sensitive group was significantly lower than that of insensitive group. QRT-PCR results confirmed that RP11-135L22.1 was lowly expressed in ovarian cancer. The overall survival of patients was positively correlated with the expression of RP11-135L22.1. Furthermore, RP11-135L22.1 was associated with FIGO stage and tumor size. Flow cytometry showed that cisplatin could induce apoptosis and arrest cell cycle in ovarian cancer cells lines. CCK8 assay showed that cisplatin decreased viability of ovarian cancer cells. For in vitro study, HO8910 cells were cultured with medium containing different concentrations of cisplatin or treated with cisplatin for different times. The results revealed that RP11-135L22.1 expression was negatively correlated with the treating time and dose of cisplatin. Western blot showed that cisplatin induced autophagy in ovarian cancer cells in a time- and dose-dependent manner. Cisplatin combined with RP11-135L22.1 can reduce autophagy, increase the apoptosis and inhibit its activity of ovarian cancer cells to a certain extent.

CONCLUSIONS

Cisplatin can induce autophagy in HO8910 ovarian cancer cells. After overexpression of RP11-135L22.1, it inhibited cisplatin-induced autophagy, thus enhancing the effect of cisplatin on ovarian cancer cells.

Ibrutinib presents antitumor activity in skin cancer and induces autophagy

OBJECTIVE

Skin cancer is one of the most common malignancies in dermatology. Patient compliance and prognosis of skin cancer are poor. Ibrutinib, a Bruton's Tyrosine Kinase (BTK) inhibitor, is a new anticancer drug used to treat many cancers. Therefore, we aimed to explore the role of ibrutinib in the treatment of skin cancer.

MATERIALS AND METHODS

Cell Counting Kit-8 (CCK8) and plate cloning assay were used to detect cell proliferation. Apoptosis was determined by flow cytometry. Western blotting analysis was used to analyze the expression of key proteins that regulated autophagy. Proliferation and apoptosis of skin cancer cells and induction of autophagy induced by ibrutinib were evaluated.

RESULTS

CCK8 plate cloning assays showed that ibrutinib can gradually inhibit the skin cancer cell proliferation as the treatment time and dose increased. Results of flow cytometry showed that apoptosis in skin cancer cells were induced after ibrutinib treatment. Western blot showed that autophagy in skin cancer cells was found induced by ibrutinib and also related to the time and concentration of ibrutinib treatment. Combination treatment of ibrutinib and 3MA for skin cancer cells can significantly increase apoptosis.

CONCLUSIONS

Ibrutinib has anti-tumor activity in skin cancer and can induce autophagy. Binding to autophagy inhibitors can promote ibrutinib's anti-skin cancer activity. Our experimental results provided new ideas for developing skin cancer drugs.

Current knowledge of nocardiosis in teleost fish

Nocardia sp. is the causative agent of nocardiosis, a lethal granulomatous disease of the skin, muscle, and various inner tissues affecting various teleost and shellfish. Four species of Nocardia have been isolated from diseased fish and shellfish, namely Nocardia asteroides, Nocardia seriolae, Nocardia salmonicida and Nocardia crassostreae. Therefore, in fish aquaculture, nocardiosis has caused severe economic losses, especially in the Asian region. Considerable research has been performed, since the first report of identified Nocardia sp. in fish, to characterize Nocardia sp. and identify rapid detection techniques, immune response against infection and prophylactic approaches. In this review, the current state of knowledge about nocardiosis in fish has been presented, including the pathogenesis, diagnosis, host immune response and vaccine development.

An Evaluation of the ACEP Guideline for Mild Head Injuries in Taiwan

Introduction

Traumatic brain injury (TBI) is an important issue in the emergency department. In the United States, the American College of Emergency Physicians (ACEP) published clinical guideline to select patients with mild head injuries for head computed tomography (CT) scans in 2008. The aim of this study was to identify the possible benefits of compliance with these guidelines for mild head injury patients in Taiwan.

Method

This was a secondary analysis on our previous study published for association of hypertension and head injuries. In our previous study, we collected data about 1290 patients with head injuries who received brain CT scans in the emergency department from September 2012 to August 2013 for a study regarding the association between head injury and hypertension. In present study, we subjected this data to further analysis to try to validate the ACEP clinical policy for mild head injuries.

Results

Of these 1,290 patients, 154 were found to have brain haemorrhage on the initial brain CT scan, and 5 were in need of neurosurgical intervention. A total of 859 patients met the ACEP guideline criteria, and 117 of these had brain haemorrhages. The sensitivity and specificity of the ACEP guideline to predict brain haemorrhage were 75.97% (95% confidence interval [CI], 68.44% to 82.48%) and 34.68% (95% CI, 31.91% to 37.53%), respectively. In predicting neurosurgical intervention, the sensitivity and specificity of the guideline were 100% (95% CI, 47.82% to 100%) and 33.54% (95% CI, 30.96% to 36.2%), respectively.

Conclusion

Although adoption of the ACEP clinical policy may reduce the number of brain CT scans in mild head injury patients who may need neurosurgical interventions, it is not a good selection tool in Taiwan.

Abstract P3-02-07: Predictors associated with MRI surveillance screening in women with a personal history of unilateral breast cancer but without a genetic predisposition for future contralateral breast cancer

Purpose

Women with a personal history of breast cancer (BC), in the absence of genetic predisposition or significant family history, are generally categorized as having an intermediate (15-20%) risk of developing future BC. Screening MRI is recommended as a supplement to mammography for women with a ≥20% lifetime risk. However, models available to calculate risk exclude women with a personal history of BC. Thus, there has existed no reliable mechanism to calculate future risk in these women to refine MRI surveillance recommendations. The Manchester score was recently developed and intended to inform contralateral breast cancer (CBC) risk for surgical decision making. We hypothesized that the score could be informative to guide follow-up imaging recommendations among women with a personal history of BC.

Patients & Methods

322 women with newly-diagnosed, non-metastatic, unilateral BC were seen in multidisciplinary breast clinic and underwent unilateral surgery (either breast conserving surgery or mastectomy) at our institution between June 2012 and November 2015. Using life expectancy, family history, genetic mutation status, and endocrine therapy use, we calculated the Manchester score, i.e. CBC risk, for all women. Patients were categorized as low- (&lt;10% CBC lifetime risk), above average- (10-20%), moderate- (20-30%), and high-risk (&gt;30%). We also reviewed the rationale that treating physicians noted for recommending MRI surveillance. Univariate logistic regression analysis (UVA) was used to assess if Manchester score was predictive of MRI surveillance in addition to other known factors.

Results

In the entire cohort, 75.8% (n=244) were low-risk for CBC, 18.6% (n=60) were above average-risk, 4.3% (n=14) were moderate-risk, and 1.2% (n=4) were high-risk. Using a 20% CBC risk as a threshold for MRI justification, 5.6% (n=18) met indications for MRI surveillance. Among the 21.7% (n=70) undergoing MRI surveillance, 57.1% (n=40) were low-risk, 32.9% (n=23) were above average-risk, 7.1% (n=5) were moderate-risk, and 2.9% (n=2) were high-risk. There was a significant trend for higher rates of MRI surveillance as the risk score increased (odds ratio, OR 1.1, p&lt;0.0001). On UVA, the highest odds for MRI surveillance were in women with a mammographically-occult BC history (OR 9.35, p&lt;0.0001), pre-operative breast MRI use (OR 8.41, p&lt;0.0001), and dense breast tissue (OR 4.88, p&lt;0.0001). The top clinician-endorsed reasons for MRI surveillance were dense breast tissue (61.4%), young age at diagnosis (28.6%), and mammographically-occult BC history (25.7%).

Conclusions

Although Manchester score was significantly predictive for MRI surveillance, we identified a large subset of women with &lt;20% calculated CBC risk who underwent MRI surveillance (90.0% of the cohort undergoing MRI) and a small subset with &gt;20% CBC risk who continue with mammography alone (4.4%). Overall, concern about poor detection of a future CBC appeared to dominate the selection of surveillance MRI use, even within a largely low-risk population. We believe this calculation could be informative prospectively to select surveillance strategies in women at a high future risk of CBC.

Citation Format: Hegde JV, Wang P-C, Kusske A, Hoyt AC, Hurvitz S, McCloskey SA. Predictors associated with MRI surveillance screening in women with a personal history of unilateral breast cancer but without a genetic predisposition for future contralateral breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-07.

Establishing the distribution of satellite lesions in intermediate- and high-risk prostate cancer: implications for focused radiotherapy

BACKGROUND

In focused radiotherapy for prostate cancer (PC), a full dose of radiation is delivered to the index lesion while reduced dose is delivered to the remaining prostate to reduce morbidity. As PC is commonly multifocal, we investigated whether baseline clinical characteristics or multiparametric magnetic resonance imaging (mpMRI) may be useful to predict the actual pathologic distribution of PC in men with intermediate- or high-risk PC, which may better inform how to deliver focused radiotherapy.

METHODS

A retrospective single-institutional study was performed on 71 consecutive men with clinically localized, intermediate- or high-risk PC who underwent mpMRI followed by radical prostatectomy (RP) from January 2012 to December 2012. Logistic regression analysis was performed to evaluate preoperative predictors for satellite lesions. Performance characteristics of mpMRI to detect satellite lesions and the extent of prostate disease (one hemi-gland vs both) were also evaluated.

RESULTS

In all, 50.7% had satellite lesions on mpMRI. On RP specimen analysis, 66.2% had satellite lesions and 55.3% of these satellite lesions had pathologic Gleason score (pGS)⩾3+4. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for mpMRI detecting a satellite lesion being present in the RP specimen were 59.6%, 66.7%, 77.8%, 45.7% and 62.0%, respectively. The presence of MRI satellite lesions was the only preoperative predictor significantly associated with finding satellite lesions on final pathology (hazard ratio (HR), 2.95, P=0.040). There was agreement in 76.1% of the entire cohort for unilateral vs bilateral disease when incorporating both biopsy and mpMRI information and comparing with the RP specimen.

CONCLUSIONS

In intermediate risk or greater PC, only the presence of mpMRI satellite lesions could predict for pathologic satellite lesions. While combining biopsy and mpMRI information may improve preoperative disease localization, the relatively high incidence of bilateral hemi-gland involvement with pGS ⩾7 satellite lesions makes it challenging to appropriately select men eligible for hemi-gland therapy.

Effect of karst rocky desertification on soil fungal communities in Southwest China

Karst mountainous ecosystems are associated with karst rocky desertification (KRD), which can greatly impact soil structure and function. Despite the importance of soil microbes as a major factor maintaining ecosystem stability, we know little about the effect on soil fungal communities of KRD in karst regions. We investigated this relationship across a gradient of KRD soils from Guizhou, China by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). Fungal diversity indices (Shannon-Wiener, richness, and evenness) significantly differed (P < 0.05) based on KRD severity, being lowest in moderately affected areas. Cluster analysis showed that the five sites examined clustered into two main groups according to KRD grade (high and low). Moreover, a homology search using sequences recovered from PCR-DGGE bands showed that the dominant fungi in each community varied remarkably, and included Aspergillus, Aphanoascus, Blastomyces, Fusarium, Glomus, Geomyces, Gibberella, Mortierella, Tetracladium, and Tumularia species, and an unclassified group. In conclusion, these findings demonstrate that KRD has a significant impact on soil fungal communities.

Genetic characteristics of Streptococcus dysgalactiae isolated from cage cultured cobia, Rachycentron canadum (L.)

Disease outbreaks occurred during 2007-2013 in Taiwan with 2.5-10% mortality among the cage cultured cobia, Rachycentron canadum (L.), characterized by the presence of polyserositis, pericarditis and peritonitis. The micro-organisms isolated from internal organs were Gram-positive cocci. The isolates were confirmed as Streptococcus dysgalactiae by a polymerase chain reaction assay that yielded the expected specific 259 bp amplicon. Additionally, partial sequence of the 16S-23S rDNA intergenic spacer region of the GCS strain isolates from fish was also compared and produced 100% sequence identity with S. dysgalactiae (GenBank accession number AB252398). The genetic characterization was then determined by pulsed-field gel electrophoresis (PFGE) analysis. Based on PFGE, the Apa I or Sma I digestion patterns of chromosomal DNA of these isolates were grouped into three main clusters. Taiwanese strains were divided into two clusters, and the tet(M) gene was detected in cluster 1 (pulsotypes: A1-A2 and S1-S3), but not in cluster 2 strains (pulsotypes: A3-A4 and S4-S5). Three Japanese strains from amberjack, Seriola dumerili (Risso), were grouped into cluster 3 (pulsotypes: A5-A7 and S6-S8) and displayed no mortality to cobia in the challenge experiment. Conversely, Taiwanese strains from cobia and snubnose pompano, Trachinotus blochii (L.), displayed a mortality rate of 50-87.5% in cobia.

Genetic diversity of Ceratoides arborescens, a species endemic to China, detected by inter-simple sequence repeat (ISSR)

In order to investigate genetic diversity and population structure of Ceratoides arborescens, six populations were selected from different steppe types in Inner Mongolia grasslands of China. Inter-simple sequence repeat (ISSR) markers were used to assess the genetic diversity within and among natural populations of C. arborescens. Thirteen ISSR primers generated 154 discernible DNA bands, of which 151 (98.05%) were polymorphic. High genetic diversity was detected at the species level [percentage of polymorphic loci (PPB) = 98.05%; H = 0.2984; I = 0.4557], whereas, relatively low genetic diversity existed within populations (PPB = 80.62%; H = 0.2675; I = 0.4031). Analysis of molecular variance showed that variation existed mainly within populations (73.25%) rather than among populations (26.75%), which was in line with the high level of gene flow (Nm = 4.3332). The Mantel test found no significant correlation between genetic distance and geographic distance (r = 0.7522, P < 0.05). Six populations were clustered into two main groups, a desert steppe group and a typical steppe group.

Hypoxia inducible factor 2α/insulin-like growth factor receptor signal loop supports the proliferation and Oct-4 maintenance of mouse germline stem cells

Hypoxia inducible factor 2α (HIF-2α) is critical for primordial germ cell (PGC) survival as knockout of HIF-2α (HIF-2α(-/-)) decreases both expression of Oct-4 and PGC number in genital ridge. Hypoxia is known to stabilize HIF-2α protein from proteasomal degradation. However, little is known about the hypoxia-associated endocrinal signaling in HIF-2α expression. The current work demonstrates a role for an endocrine insulin-like growth factor-I receptor (IGF-IR)-PI3K/Akt-mTOR-HIF-2α regulatory loop in the proliferation and Oct-4 maintenance of PGC-like alkaline phosphatase positive mouse germline stem cells (AP(+)GSCs). We found that hypoxia greatly increased the cell proliferation and the levels of nuclear Oct-4/HIF-2α protein of AP(+)GSCs. The hypoxic-AP(+)GSCs presented stronger stemness ability for germ cell differentiation than normoxic, with expressions of c-KIT (differentiation germ cell marker), VASA (differentiation germ cell marker) and SCP3 (meiotic marker) using a renal capsule transplantation assay. Meanwhile, hypoxia significantly increased the expression levels of secreted-IGF-I and IGF-IR. The IGF-I dose dependently increased the HIF-2α expression levels in AP(+)GSCs; and, the inhibition of IGF-IR by RNA interference (shIGF-IR) or LY294002 (PI3K inhibitor)/Rapamycin (mTOR inhibitor) effectively suppressed the IGF-I- and/or hypoxia-induced HIF-2α and Oct-4 expression, suggesting that the IGF-IR and its downstream Akt/mTOR signaling are involved in the IGF-I/hypoxia effects. Additionally, knockdown of HIF-2α dramatically suppressed Oct-4 and IGF-IR protein levels in AP(+)GSC cells. In conclusion, the present study demonstrates a regulatory loop of IGF-IR-PI3K/Akt-mTOR-HIF-2α in proliferation and Oct-4 maintenance of PGC-like AP(+)GSCs under hypoxia. This finding provides insights into the niche endocrinology underlying early germ cell development.

White spot syndrome virus epizootic in cultured Pacific white shrimp Litopenaeus vannamei (Boone) in Taiwan

White spot syndrome virus (WSSV) has caused significant losses in shrimp farms worldwide. Between 2004 and 2006, Pacific white shrimp Litopenaeus vannamei (Boone) were collected from 220 farms in Taiwan to determine the prevalence and impact of WSSV infection on the shrimp farm industry. Polymerase chain reaction (PCR) analysis detected WSSV in shrimp from 26% of farms. Juvenile shrimp farms had the highest infection levels (38%; 19/50 farms) and brooder shrimp farms had the lowest (5%; one of 20 farms). The average extent of infection at each farm was as follows for WSSV-positive farms: post-larvae farms, 71%; juvenile farms, 61%; subadult farms, 62%; adult farms, 49%; and brooder farms, 40%. Characteristic white spots, hypertrophied nuclei and basophilic viral inclusion bodies were found in the epithelia of gills and tail fans, appendages, cephalothorax and hepatopancreas, and virions of WSSV were observed. Of shrimp that had WSSV lesions, 100% had lesions on the cephalothorax, 96% in gills and tail fans, 91% on appendages and 17% in the hepatopancreas. WSSV was also detected in copepoda and crustaceans from the shrimp farms. Sequence comparison using the pms146 gene fragment of WSSV showed that isolates from the farms had 99.7-100% nucleotide sequence identity with four strains in the GenBank database--China (AF332093), Taiwan (AF440570 and U50923) and Thailand (AF369029). This is the first broad study of WSSV infection in L. vannamei in Taiwan.

Development of a sensitive and specific LAMP PCR assay for detection of fish pathogen Lactococcus garvieae

Based on use of a loop-mediated isothermal amplification (LAMP) identification protocol, this study attempted to detect Lactococcus garvieae in fish by using primer sets designed from an L. garvieae alpha/beta fold family hydrolase gene. Reaction time and temperatures were optimized for 60 min at 60°C with the resulting amplicons visualized by adding SYBR Green I to the reaction tube. The assay specificity was assessed using 45 different bacterial strains. Positive results were observed in all 30 L. garvieae isolates from various aquatic animals. No false-positive results were observed in 15 non-L. garvieae strains. The detection limit of the LAMP assay was 10-fold more sensitive than the conventional polymerase chain reaction (PCR) targeting 16S rDNA when using purified L. garvieae DNA. The detection limit of the LAMP assay was approximately 300 colony-forming units (CFU) using crude bacterial lysates, 100-fold more sensitive than PCR. Furthermore, L. garvieae in spleen, kidney and brain of experimentally challenged tilapia and grey mullet were detected using this optimized LAMP assay. Results of this study demonstrate the effectiveness of LAMP in providing a rapid yet simple test for detecting L. garvieae in fish.

Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus

OBJECTIVE

To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms.

METHODS

We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brainstem responses (ABRs). Data were compared among TPE, TNE, and CE groups.

RESULTS

The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs.

CONCLUSION

This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.

EMG-guided salpingopharyngeus Botox injection for palatal myoclonus

Palatal myoclonus (PM) is a rare neurological disorder characterized by involuntary movements of the soft palate musculature causing objective clicking tinnitus. Two forms are recognized as distinct clinical entities, with poorly understood pathogenesis: essential and symptomatic PM. The intrusive nature of the tinnitus prompts patients to seek medical advice. Conventional medical treatments with anxiolytics, antidepressants, and anticonvulsants have limited efficacy in these patients. In this case report, electromyography-guided injection of botulinum toxin type A (Botox; Allergan, Irvine, CA, USA) to the involved salpingopharyngeus and tensor veli palatini yielded satisfactory results with minimal temporary adverse effects.

Development of a multiplex polymerase chain reaction to detect five common Gram-negative bacteria of aquatic animals

A multiplex polymerase chain reaction (m-PCR) technique was developed as a rapid and accurate diagnostic tool for identifying five major Gram-negative bacilli -Vibrio vulnificus, V. parahaemolyticus, Aeromonas hydrophila, Chryseobacterium meningosepticum and Edwardsiella tarda- that cause major diseases in cultured aquatic animals in Taiwan. The expected amplicons for V. vulnificus, V. parahaemolyticus, A. hydrophila, C. meningosepticum and E. tarda were 410, 368, 685, 180 and 230bp, respectively. The assay was shown to be specific for the target pathogens. The sensitivities of detection were estimated to be 20.5fg∼200pg of genomic DNA or 10(2) ∼10(4) colony-forming units (cfu) of bacterial isolates when adopted as PCR templates. The m-PCR was capable of simultaneously amplifying target fragments from bacterial genome DNA mixed with the DNA extracted from viscera and tissues taken from fish without affecting the performance of the method.

64-slice CT angiography for the detection of functionally significant coronary stenoses: comparison with stress myocardial perfusion imaging

OBJECTIVE

To evaluate the accuracy of 64-slice CT angiography (CTA) compared with single photon emission CT (SPECT) myocardial perfusion imaging (MPI), which served as the reference standard, for the detection of functionally significant coronary artery disease (CAD).

METHODS

141 consecutive patients (60 ± 10 years, 101 men) were investigated with 64-slice CTA and SPECT MPI; a subset of 35 patients had additional invasive coronary angiography (ICA). The data from CTA and ICA were compared with those from MPI for both cut-offs of ≥ 50% and ≥ 70% stenosis, respectively.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and accuracy of CTA, using a cut-off of ≥ 50% for significant stenosis, in detecting inducible perfusion defects on MPI were 96% [95% confidence interval (CI) 88-100%], 61% (95% CI 52-70%), 37% (95% CI 23-49%), 99% (95% CI 97-100%) and 68%, respectively, in patient-based analysis and 97% (95% CI 91-100%), 86% (95% CI 83-89%), 33% (95% CI 24-42%), 100% (95% CI 99-100%) and 87%, respectively, in vessel-based analysis. Applying a cut-off of ≥ 70% for significant stenosis, CTA yielded the following sensitivity, specificity, positive and negative predictive values, and accuracy for the detection of inducible MPI defects: by patient, 65% (95% CI 46-84%), 95% (95% CI 91-99%), 74% (95% CI 50-92%), 92% (95% CI 87-97%) and 89%, respectively; by vessel, 58% (95% CI 42-74%), 97% (95% CI 95-99%), 62% (95% CI 45-79%), 97% (95% CI 95-99%) and 95%, respectively.

CONCLUSION

64-slice CTA is a reliable tool to exclude functionally significant CAD when using a cut-off of ≥ 50% diameter stenosis. By contrast, a cut-off of ≥ 70% diameter narrowing is a strong predictor of ischaemia.

Risk Factors of Acute ST Segment Elevation Myocardial Infarction Patients without Chest Pain

Introduction

To identify factors associated with ST-segment myocardial infarction (STEMI) patients who had no chest pain, and to improve recognition of STEMI patients without presentation of chest pain in the emergency department (ED).

Method

Clinical characteristics and presentations were recorded in patients diagnosed with STEMI in the ED in a retrospective study of patients treated from 2006 to 2009. Patients with and without chest pain were compared according to clinical features.

Results

Among 260 STEMI patients, 12.7% of patients had no chest pain presentation in the ED. Syncope, epigastric pain, and dyspnea accounted for more than 60% of symptoms in STEMI patients without chest pain. Diabetes mellitus (DM), cerebrovascular accident (CVA), and old age were risk factors for STEMI patients without chest pain.

Conclusions

DM, CVA, and elderly patients are more likely to be without chest pain when STEMI occurred.

Safety and efficacy of two-step peginterferon α-2a treatment in patients of chronic hepatitis B with acute exacerbation

The focus of this study was to evaluate the safety and efficacy of sequential peginterferon α-2a (Pegasys) therapy for chronic hepatitis B with acute exacerbation [ALT > 10 × upper limit of normal (ULN), bilirubin <2.0 mg/dL]. Four groups of patients categorized by HBeAg status and treatment regimens were studied since May 2007. Nineteen HBeAg-positive patients (Group 1) had received entecavir  pretreatment  (when ALT > 10 × ULN) plus Pegasys (180 μg/kg/week, when ALT was 5-10 × ULN) for 24 weeks. Thirteen HBeAg-negative patients (Group 2) had the same protocol for 48 weeks. In both groups, entecavir was then discontinued 14 days after the initiation of Pegasys. The results were compared, respectively, to 35 HBeAg-positive patients (Group 3) and 24 HBeAg-negative patients (Group 4), all with ALT > 5 × ULN, under continual entecavir monotherapy. The ALT levels of patients in Group 1 and 2 who had received entecavir pretreatment for a duration of 19.63 ± 3.34 days were below four times of ULN following 4 weeks of Pegasys treatment. At week 96, the rates of sustained virological response were 69.2% (9/13) and 80% (8/10), and the relapse rates were 23.1% (3/13) and 11.2% (1/9) for HBeAg-positive and HBeAg-negative patients with two-step Pegasys treatment, respectively. The HBeAg seroconversion rates were 46.2% in Group 1, and 42.1% in Group 3; HBsAg loss rates were 15.4% (2/13) in Group 1, and 30% (3/10) in Group 2, whereas none achieved HBsAg loss with entecavir monotherapy (Group 3 and 4). The two-step Pegasys treatment offers an alternative, other than the nucleos(t)ides, for treating chronic hepatitis B with acute exacerbation and provides a safe, efficacious, short-term and finite strategy.

Safety and efficacy of two-step peginterferon α-2a treatment in patients of chronic hepatitis B with acute exacerbation

The focus of this study was to evaluate the safety and efficacy of sequential peginterferon α-2a (Pegasys) therapy for chronic hepatitis B with acute exacerbation [ALT > 10 × upper limit of normal (ULN), bilirubin <2.0 mg/dL]. Four groups of patients categorized by HBeAg status and treatment regimens were studied since May 2007. Nineteen HBeAg-positive patients (Group 1) had received entecavir  pretreatment  (when ALT > 10 × ULN) plus Pegasys (180 μg/kg/week, when ALT was 5-10 × ULN) for 24 weeks. Thirteen HBeAg-negative patients (Group 2) had the same protocol for 48 weeks. In both groups, entecavir was then discontinued 14 days after the initiation of Pegasys. The results were compared, respectively, to 35 HBeAg-positive patients (Group 3) and 24 HBeAg-negative patients (Group 4), all with ALT > 5 × ULN, under continual entecavir monotherapy. The ALT levels of patients in Group 1 and 2 who had received entecavir pretreatment for a duration of 19.63 ± 3.34 days were below four times of ULN following 4 weeks of Pegasys treatment. At week 96, the rates of sustained virological response were 69.2% (9/13) and 80% (8/10), and the relapse rates were 23.1% (3/13) and 11.2% (1/9) for HBeAg-positive and HBeAg-negative patients with two-step Pegasys treatment, respectively. The HBeAg seroconversion rates were 46.2% in Group 1, and 42.1% in Group 3; HBsAg loss rates were 15.4% (2/13) in Group 1, and 30% (3/10) in Group 2, whereas none achieved HBsAg loss with entecavir monotherapy (Group 3 and 4). The two-step Pegasys treatment offers an alternative, other than the nucleos(t)ides, for treating chronic hepatitis B with acute exacerbation and provides a safe, efficacious, short-term and finite strategy.

Susceptibility-weighted imaging in patients with pyogenic brain abscesses at 1.5T: characteristics of the abscess capsule

BACKGROUND AND PURPOSE

SWI is a high-resolution 3D, fully velocity-compensated gradient-echo sequence that uses both magnitude and phase data. The purpose of this study was to investigate the phase behavior of the capsule of pyogenic brain abscesses with noncontrast SWI.

MATERIALS AND METHODS

Fourteen patients with pyogenic brain abscesses were studied at 1.5T. In all of the patients, SWI images were obtained and reviewed in addition to conventional MR images. Phase values within the abscess capsule were measured and compared with those from the abscess cavities and contralateral normal white matter using 1-way repeated measures ANOVA with post hoc Bonferroni analysis.

RESULTS

SWI phase images showed mild hypointesity in 6 patients, isointensity in 3 patients, and mixed iso- to mild hypointensity in 5 patients. The means of phase in the cavity, rim of abscesses, and contralateral normal white matter were -7.552 × 10(-3) ± 0.024, -0.105 ± 0.080, and +0.029 ± 0.011 radians, respectively. Post hoc comparisons showed significant differences between any pair of the 3 regions (abscess cavity, rim capsule, and normal white matter) in SWI (all Ps < .005).

CONCLUSIONS

SWI phase imaging shows evidence of paramagnetic substances in agreement with the presence of free radicals from phagocytosis. SWI may provide additional information valuable in the characterization of pyogenic brain abscesses.

Increasing insulin resistance is associated with increased severity and prevalence of gastro-oesophageal reflux disease

BACKGROUND

The diagnosis of gastro-oesophageal reflux disease (GERD) is based on reflux symptoms. Although metabolic syndrome has been linked to erosive oesophagitis (EO), the impact of insulin resistance, the core of the metabolic syndrome, on reflux symptoms remains to be elucidated.

AIM

To assess the effects of insulin resistance on GERD, including both endoscopic findings and symptoms.

METHODS

A total of 743 sonographic noncirrhotic adult subjects, who underwent an upper gastrointestinal endoscopic examination, completed a gastro-oesophageal reflux questionnaire and had available fasting insulin data were included. Endoscopic findings were classified according to the Los Angeles classification. Homeostatic model assessment-insulin resistance (HOMA-IR) index was used to evaluate the status of insulin resistance. Univariate and multivariate approaches were used to evaluate the associations between insulin resistance and GERD.

RESULTS

Older age, male gender, smoking and alcohol consumption increased the prevalence of EO, but not GERD symptoms. A large waist circumference, high fasting blood glucose levels and high number of metabolic syndrome components were associated with increased prevalence of both EO and GERD symptoms, while high blood pressure was associated with increased prevalence of EO only. Moreover, higher scores in the gastro-oesophageal reflux questionnaire were associated with higher HOMA-IR index, and higher HOMA-IR index was associated with increased prevalence of EO (adjusted odds ratio 1.14, 95% CI 1.03-1.26, P = 0.012).

CONCLUSIONS

Our findings demonstrate clear associations between insulin resistance, metabolic syndrome and GERD. Whether reducing insulin resistance may improve GERD symptoms or EO deserves prospective study.

Koi herpesvirus epizootic in cultured carp and koi, Cyprinus carpio L., in Taiwan

Koi herpesvirus (KHV) poses a significant threat to cultured koi and common carp, both Cyprinus carpio L. Since the first reported case in Israel in 1998, KHV has rapidly spread worldwide. This study investigates the spread of KHV to Taiwan by collecting 49 cases of suspected common carp and koi infections from 2003 to 2005 for analysis. Clinical signs included lethargy, anorexia, increased respiratory movements and uncoordinated swimming. Hyperaemia, haemorrhage on body surface and necrotic gill filaments were recorded. Gill epithelial hyperplasia, necrosis and eosinophilic intranuclear inclusion bodies were observed by histological examination, while virions were detected using transmission electron microscopy. By detecting the presence of the KHV thymidine kinase (TK) gene and the KHV 9/5 gene using polymerase chain reaction (PCR), 37 cases were identified as KHV-positive, and the cumulative mortality of infected fish was 70-100%. Positive cases showed identical sequences for the genes analysed, implying that they were of the same origin. For the KHV 9/5 gene sequence, these cases exhibited 100% identity with the Japanese strain (TUMST1, accession number AP008984) and 99% identity with the Israeli (KHV-I, DQ177346) and US (KHV-U, DQ657948) strains. Additionally, a loop-mediated isothermal amplification (LAMP) assay was performed and found to be more sensitive than PCR tests, suggesting its potential use as a rapid diagnostic method for KHV. This is the first epidemiological study of KHV infection in cultured common carp and koi in Taiwan.

Efficacy of an intravenous proton pump inhibitor after endoscopic therapy with epinephrine injection for peptic ulcer bleeding in patients with uraemia: a case-control study

BACKGROUND

Patients with peptic ulcer bleeding and uraemia are prone to re-bleeding.

AIM

To compare the efficacy of an intravenous proton pump inhibitor in treating peptic ulcer bleeding in patients with uraemia and those without uraemia.

METHODS

High-risk peptic ulcer bleeding patients received endoscopic therapy with epinephrine (adrenaline) injection plus intravenous omeprazole (40 mg bolus followed by 40 mg infusion every 12 h) for 3 days. Re-bleeding, volume of blood transfusion, hospital stay, need for surgery, and mortality were analysed.

RESULTS

The uraemic group had similar 7-day re-bleeding rate (6/42, 14.29% vs. 6/46, 13.04%, P = 0.865) to that of non-uraemic patients, but more re-bleeding episodes beyond 7 days (4/42, 9.52% vs. 0/46, 0%, P = 0.032, OR [95% CI] = 1.105 [1.002-1.219]) and all-cause mortality (4/42 vs. 0/46 P = 0.032, OR [95% CI] = 1.105 [1.002-1.219]). The uraemic group also had more units of blood transfusion after endoscopic therapy (mean +/- s.d. 4.33 +/- 3.35 units vs. 2.15 +/- 1.65 units, P < 0.001), longer hospital stay (mean +/- s.d. 8.55 +/- 8.12 days vs. 4.11 +/- 1.60 days, P < 0.001) and complications during hospitalization (9/42 vs. 0/46, P = 0.001, OR [95% CI] = 1.273 [1.087-1.490]).

CONCLUSION

Endoscopic therapy with epinephrine injection plus an intravenous proton pump inhibitor can offer protection against early re-bleeding in uraemic patients with peptic ulcer bleeding, but has a limited role beyond 7 days.

Nocardia seriolae infection in the three striped tigerfish, Terapon jarbua (Forsskål)

An epizootic in pond cultured three striped tigerfish, Terapon jarbua, in Taiwan was caused by Nocardia seriolae. Diseased fish first showed clinical signs and mortalities in February and March 2003. The cumulative mortality within 2 months was 2.4% (1200 of 50 000) and affected fish were 7 months old with total lengths from 18 to 25 cm. Most affected fish were pale and lethargic with haemorrhages and ulcers on the skin. The most significant gross pathological changes were varying degrees of ascites and enlargement of the spleen, kidney and liver. Obvious white nodules, varying in size, were found in these organs. Bacteria were either coccal or filamentous in appearance, with bead-like forms. Isolates from diseased fish were characterized using the API ZYM (Analytical profile index; Bio Mérieux, France) systems and conventional tests and identified as Nocardia sp. The isolate was designated NS127 and was confirmed as N. seriolae by a polymerase chain reaction assay that gave the expected specific 432 bp amplicon. In addition, its 16S rDNA sequence gave 100% sequence identity with N. seriolae. A partial sequence of the 16S rRNA gene, heat shock protein gene and RNA polymerase gene (rpo B) of NS127 and the type strain of N. seriolae BCRC 13745 formed a monophyletic clade with a high sequence similarity and bootstrap value of 99.9%. White nodules induced in experimental fish were similar to naturally infected cases and N. seriolae was re-isolated on brain heart infusion agar. This is the first report of N. seriolae-infection in three striped tigerfish in aquaculture.

Recurrence of peptic ulcer in uraemic and non-uraemic patients after Helicobacter pylori eradication: a 2-year study

BACKGROUND

The role of Helicobacter pylori in the pathogenesis of peptic ulcer disease in patients with uraemia remains unclear.

AIM

To evaluate the long-term effect of H. pylori eradication in these patients.

METHODS

Uraemic and non-uraemic patients with peptic ulcer were enrolled in this study. Patients having history of non-steroidal anti-inflammatory drugs use or cardiovascular disease that need aspirin use were excluded. After confirmation of H. pylori infection, they received a triple therapy and were followed up for 2 years.

RESULTS

Between September 1999 and December 2005, 34 patients (41%) of the end-stage renal disease [H. pylori (+) group] and 67 (84%) of the non-uraemic patients with peptic ulcer disease (PU group) received anti-H. pylori therapy. After triple therapy, 32 (94%) from the end-stage renal disease group and 64 (96%) from the peptic ulcer group obtained successful eradication. During the 2-year follow-up, three patients in the end-stage renal disease group were excluded because of the presence of cardiovascular disease and aspirin use in two cases and died of heart failure in one case; two patients in peptic ulcer group refused follow-up. Finally, 29 uraemic and 62 non-uraemic patients had achieved the follow-up. Recurrence of peptic ulcer was more in the end-stage renal disease group than in the peptic ulcer group with intention-to-treat analysis (eight of 32, 25% vs. two of 64, 3%, P = 0.001, OR: 10.0, 95% CI: 1.979-50.540) or per-protocol analysis (eight of 29, 28% vs. two of 62, 3%, P < 0.001, OR: 11.4, 95% CI: 2.245-58.168).

CONCLUSIONS

Peptic ulcer recurrence after H. pylori eradication is higher in end-stage renal disease patients with peptic ulcer than in peptic ulcer patients without renal disease. Factors aside from H. pylori play an important role in peptic ulcer recurrence in end-stage renal disease patients.

Work-organisational and personal factors associated with upper body musculoskeletal disorders among sewing machine operators

OBJECTIVE

To assess the contribution of work-organisational and personal factors to the prevalence of work-related musculoskeletal disorders (WMSDs) among garment workers in Los Angeles.

METHODS

This is a cross-sectional study of self-reported musculoskeletal symptoms among 520 sewing machine operators from 13 garment industry sewing shops. Detailed information on work-organisational factors, personal factors, and musculoskeletal symptoms were obtained in face-to-face interviews. The outcome of interest, upper body WMSD, was defined as a worker experiencing moderate or severe musculoskeletal pain. Unconditional logistic regression models were adopted to assess the association between both work-organisational factors and personal factors and the prevalence of musculoskeletal pain.

RESULTS

The prevalence of moderate or severe musculoskeletal pain in the neck/shoulder region was 24% and for distal upper extremity it was 16%. Elevated prevalence of upper body pain was associated with age less than 30 years, female gender, Hispanic ethnicity, being single, having a diagnosis of a MSD or a systemic illness, working more than 10 years as a sewing machine operator, using a single sewing machine, work in large shops, higher work-rest ratios, high physical exertion, high physical isometric loads, high job demand, and low job satisfaction.

CONCLUSION

Work-organisational and personal factors were associated with increased prevalence of moderate or severe upper body musculoskeletal pain among garment workers. Owners of sewing companies may be able to reduce or prevent WMSDs among employees by adopting rotations between different types of workstations thus increasing task variety; by either shortening work periods or increasing rest periods to reduce the work-rest ratio; and by improving the work-organisation to control psychosocial stressors. The findings may guide prevention efforts in the garment sector and have important public health implications for this workforce of largely immigrant labourers.

Endoscopy-aided laser therapy for intractable granular myringitis

Objective: We report our technique and results for endoscopy-aided CO2 laser therapy for the treatment of intractable granular myringitis, as an out-patient office procedure.

Materials and methods: A total of 21 patients (14 women and seven men; mean age 32.6 years) were retrospectively reviewed, all of whom suffered from intractable granular myringitis and had undergone endoscopy-aided laser treatment. Granulation tissue was vaporized for one to two seconds with a CO2 laser (spot size 0.5–1 mm with a power setting of 5–10 W in continuous mode). The mean follow-up period was 11 months.

Results: Eighteen of the 21 patients (85 per cent) were cured after a single treatment. Three patients with the diffuse form of the disease required repeat laser treatments coupled with self-irrigation with a diluted vinegar solution. We noted no perforations of patients' tympanic membranes after laser vaporization. We also observed no recurrences over follow-up periods ranging from three months to 2.6 years. Our laser procedure produced no adverse effect on hearing thresholds, nor were any other complications observed.

Conclusion: Our results suggest that endoscopy-aided CO2 laser ablation is a reliable and minimally invasive method associated with low rates of recurrence and a low incidence of complications. It can be conducted as an office procedure.

Efficacy of radiofrequency volumetric tissue reduction of the soft palate in the treatment of snoring

Traditional surgery for snoring often leads to intolerable postoperative pain. A new surgical treatment, radiofrequency volumetric tissue reduction (RVTR) of the soft palate, was carried out and its effect and safety in the management of snoring were evaluated. Thirty-two patients received a single treatment of RVTR with a mean follow-up period of 4.5 months. All patients were assessed by a questionnaire using the Snore Outcomes Survey (SOS) and the Epworth Sleepiness Scale (ESS). Postoperative pain, speech and swallowing disturbances were also evaluated. The postoperative scores of SOS and ESS all significantly improved (p<0.05). Postoperative pain, speech and swallowing disturbances were all mild 1-3 days after treatment. With the success of treatment defined as a postoperative snoring index (SI) of <3 or a reduction of the SI by >5 points by the visual analogue scale, the success rate was 81.3% in patients with a respiratory disturbance index (RDI) of <20, and 50% in those with an RDI of >20. We conclude that RVTR of the soft palate is an effective treatment for snoring, resulting in only mild postoperative discomfort. A patient whose RDI was <20 had a higher success rate with a single RVTR treatment.

Transactivation via RAR/RXR-Sp1 interaction: characterization of binding between Sp1 and GC box motif

Modulation of Sp1 activity by nuclear receptors is a novel mechanism by which fat-soluble hormones regulate gene expression. We previously established that upon autoinduction of RARs by RA, RARs/RXRs physically interact with Sp1, potentiate Sp1 binding to the GC box motifs, and thus enhance transactivation of the urokinase promoter, which lacks a canonical RAR-responsive element/RXR-responsive element. Here, we examined whether a similar mechanism might participate in transcriptional regulation of other key RA-inducible genes in endothelial cells and characterized binding between Sp1 and GC box motifs. Northern blot analyses showed that in addition to urokinase, after induction of RARs, RA up-regulates GC-rich region-dependent mRNA expression of transglutaminase, TGF beta 1, and types I and II TGF beta receptors. RA failed to alter the expression of Sp1 at both mRNA and protein levels. Reporter and gel shift assays and Western blot analyses suggested that either RA-treatment or RAR/RXR-overexpression enhances transactivation of these genes through a GC-rich region and strengthens the affinity of Sp1 to GC box motifs, accompanying a potential conformational change of Sp1 as reflected in its increased immunogenicity. Detailed analyses of the GC box motifs within the urokinase and other promoters indicate that interaction between RAR/RXR and Sp1 does not occur in the presence of nonfunctional GC box motifs containing five tandem purine or pyrimidine bases at the 3'-flanking region of hexanucleotide core sequence. These findings provide insight into the molecular mechanisms underlying RARE/RXRE-independent transactivation of RA-inducible gene promoters.

Integration of polymeric membranes with microfluidic networks for bioanalytical applications

The concept of microfluidics has significantly influenced the design and the implementation of modern bioanalytical systems due to the fact that these miniaturized devices can handle and manipulate samples in a much more efficient way than conventional instruments. In an analogy to the development of microelectronics, increasingly sophisticated devices with greater functionalities have become one of the major goals being pursued in the area of micrototal analysis systems. The incorporation of polymeric membranes into microfluidic networks has therefore been employed in an effort to enhance the functionalities of these microfabricated devices. These commercially available membranes are porous, flexible, mechanically robust and compatible with plastic microfluidic networks. The large surface area-to-volume ratio of porous membrane media is particularly important for achieving rapid buffer exchange during microdialysis and obtaining ultrahigh concentration of adsorbed enzymes for various biochemical reactions. Furthermore, the membrane pore diameter in the sub-microm range eliminates the constraints of diffusional mass-transfer resistance for performing chiral separation using adsorbed protein as the chiral stationary phase. A review on the recent advancement in the integration of polymeric membranes with microfluidic networks is presented for their widespread applications in bioanalytical chemistry.

Field-effect flow control in a polydimethylsiloxane-based microfluidic system

The application of the field-effect for direct control of electroosmosis in a polydimethylsiloxane (PDMS)-based microfluidic system, constructed on a silicon wafer with a 2.0 microm electrically insulating layer of silicon dioxide, is demonstrated. This microfluidic system consists of a 2.0 cm open microchannel fabricated on a PDMS slab, which can reversibly adhere to the silicon wafer to form a hybrid microfluidic device. Aside from mechanically serving as a robust bottom substrate to seal the channel and support the microfluidic system, the silicon wafer is exploited to achieve field-effect flow control by grounding the semiconductive silicon medium. When an electric field is applied through the channel, a radial electric potential gradient is created across the silicon dioxide layer that allows for direct control of the zeta potential and the resulting electroosmotic flow (EOF). By configuring this microfluidic system with two power supplies at both ends of the microchannel, the applied electric potentials can be varied for manipulating the polarity and the magnitude of the radial electric potential gradient across the silicon dioxide layer. At the same time, the longitudinal potential gradient through the microchannel, which is used to induce EOF, is held constant. The results of EOF control in this hybrid microfluidic system are presented for phosphate buffer at pH 3 and pH 5. It is also demonstrated that EOF control can be performed at higher solution pH of 6 and 7.4 by modifying the silicon wafer surface with cetyltrimethylammonium bromide (CTAB) prior to assembly of the hybrid microfluidic system. Results of EOF control from this study are compared with those reported in the literature involving the use of other microfluidic devices under comparable solution conditions.

Integration of polymeric membranes with microfluidic networks for bioanalytical applications

The concept of microfluidics has significantly influenced the design and the implementation of modern bioanalytical systems due to the fact that these miniaturized devices can handle and manipulate samples in a much more efficient way than conventional instruments. In an analogy to the development of microelectronics, increasingly sophisticated devices with greater functionalities have become one of the major goals being pursued in the area of micrototal analysis systems. The incorporation of polymeric membranes into microfluidic networks has therefore been employed in an effort to enhance the functionalities of these microfabricated devices. These commercially available membranes are porous, flexible, mechanically robust and compatible with plastic microfluidic networks. The large surface area-to-volume ratio of porous membrane media is particularly important for achieving rapid buffer exchange during microdialysis and obtaining ultrahigh concentration of adsorbed enzymes for various biochemical reactions. Furthermore, the membrane pore diameter in the sub-microm range eliminates the constraints of diffusional mass-transfer resistance for performing chiral separation using adsorbed protein as the chiral stationary phase. A review on the recent advancement in the integration of polymeric membranes with microfluidic networks is presented for their widespread applications in bioanalytical chemistry.

Use of dexamethasone on the prophylaxis of nausea and vomiting after tympanomastoid surgery

OBJECTIVE

The aim of this study was to evaluate the prophylactic effect of dexamethasone on postoperative nausea and vomiting (PONV) in patients undergoing tympanomastoid surgery.

STUDY DESIGN

Eighty patients (n = 40 in each of two groups) undergoing tympanomastoid surgery under general anesthesia were enrolled in this randomized, double-blind, placebo-controlled study.

METHODS

After tracheal intubation, group 1 received 10 mg dexamethasone intravenously, whereas group 2 received saline intravenously. Several parameters concerning with the occurrence of PONV were evaluated.

RESULTS

We found that dexamethasone reduced the total incidence of nausea and vomiting by 45%, with a 95% confidence interval of 26% to 64% (P <.001). Furthermore, dexamethasone reduced the incidence of vomiting episodes >4 times and the incidence of patients requiring rescue antiemetics (P <.05).

CONCLUSION

Dexamethasone at a dosage of 10 mg administered intravenously is effective in preventing PONV in patients undergoing tympanomastoid surgery.

Lactococcus garvieae infection in the giant freshwater prawn Macrobranchium rosenbergii confirmed by polymerase chain reaction and 16S rDNA sequencing

An epizootic bacterial infection in the giant freshwater prawn Macrobranchium rosenbergii occurred in Taiwan from May to June 1999. The cumulative mortality was approximately 30 to 75%. The diseased prawns showed opaque and whitish muscles and were approximately 2 mo old with total lengths from 5 to 6 cm. Histopathologically, they showed marked edema and necrotic lesions with inflammation in the muscles and hepatopancreas. Bacteria isolated using brain heart infusion medium or tryptic soy agar were Gram-positive and ovoid. Three isolates from diseased prawns at different farms were tested using the API 20 Strepsystem and conventional tests and identified as Lactococcus garvieae. Experimental infections with these isolates gave gross signs and histopathological changes similar to those seen in the naturally infected prawns. The LD50 value of isolate MR1 was 6.6 x 10(5) colony forming units/prawn. Identification of MR1 was confirmed by a PCR assay for L. garvieae that gave the expected amplicon of 1100 bp. In addition, its 16S rDNA sequence (GenBank accession number AF283499) gave 99% sequence identity to Enterococcus seriolicida (synonym L. garvieae; GenBank accession number AF061005). This is the first report of confirmed L. garvieae infection in prawn aquaculture.

Integrated Plastic Microfluidic Devices with ESI-MS for Drug Screening and Residue Analysis

For this work, two different plastic microfluidic devices are designed and fabricated for applications in high-throughput residue analysis of food contaminants and drug screening of small-molecule libraries. Microfluidic networks on copolyester and poly(dimethylsiloxane) substrates are fabricated by silicon template imprinting and capillary molding techniques. The first device is developed to perform affinity capture, concentration, and direct identification of targeted compounds using electrospray ionization mass spectrometry. Poly(vinylidene fluoride) membranes sandwiched between the imprinted copolyester microchannels in an integrated platform provide continuous affinity dialysis and concentration of a reaction mixture containing aflatoxin B1 antibody and aflatoxins. The second microfluidic device is composed of microchannels on the poly(dimethylsiloxane) substrates. The device is designed to perform miniaturized ultrafiltration of affinity complexes of phenobarbital antibody and barbiturates, including the sequential loading, washing, and dissociation steps. These microfabricated devices not only significantly reduce dead volume and sample consumption but also increase the detection sensitivity by at least 1-2 orders of magnitude over those reported previously. Improvements in detection sensitivity are attributed to analyte preconcentration during the affinity purification step, limited analyte dilution in the microdialysis junction, minimal sample loss, and the amenability of ESI-MS to nanoscale sample flow rates.

Laparoscopic repair of incisional and parastomal hernias after major genitourinary or abdominal surgery

BACKGROUND AND PURPOSE

Abdominal wall or parastomal hernias following major genitourinary or abdominal surgery are a significant surgical problem. Open surgical repair is difficult because of adhesion formation and poor definition of the hernia fascial edges. Laparoscopic intervention has allowed effective correction of these abdominal wall hernias.

PATIENTS AND METHODS

From November 1997 to June 2000, 14 male and 3 female patients underwent laparoscopic abdominal wall herniorrhaphy at our institution. Of these, 13 patients received incisional and 4 parastomal hernia repair. All hernia defects were repaired using a measured piece of Gore-Tex DualMesh. A retrospective review of each patient's history and operative characteristics was undertaken.

RESULTS

All repairs were successful. No patient required conversion to an open procedure, and there were no intraoperative complications. The average operative time was 4 (range 2.5-6.5) and 4.3 (range 3.75-5.5) hours in the incisional and parastomal group, respectively. The average hospital stay was 4.9 days (range 2-12) for the incisional group and 3.8 (range 3-4) days for the parastomal group. To date, two patients experienced a recurrence of incisional hernias, at 5 and 8 months postoperatively. No recurrences have developed in the parastomal hernia repairs at 2 to 33 months.

CONCLUSION

Laparoscopic repair of abdominal wall incisional or parastomal hernias provides an excellent anatomic correction of such defects. Adhesions are lysed under magnified laparoscopic vision, and the true limits of the fascial defects are clearly identified. The DualMesh is easy to work with and has yielded excellent results. A comparison with open repair with respect to perioperative factors and long-term success is currently under way.

Analysis of integrated hepatitis B virus DNA and flanking cellular sequence by inverse polymerase chain reaction

Although hepatitis B virus (HBV) DNA has been detected in the human hepatoma cell line, HAGS 2.1, viral and cellular junction sequences have not been investigated fully. To facilitate the analysis of HBV DNA integration sites in HAGS 2.1 cells, a combination of conventional polymerase chain reaction (PCR) and inverse PCR (IPCR) was carried out to identify the junction between the viral and the cellular gene. The HBV integrant and its cellular counterpart sequence were cloned and analyzed. The sequencing data indicated that the breakpoints on the HBV integrant are at nucleotide 2111 of the C gene and nucleotide 1558 of the X gene. The length of the integrated HBV DNA in HAGS 2.1 was approximately 2.6 kb, which includes partial C, P, and X genes and an intact S gene. The cellular sequence flanking the integrated HBV gene was very similar to a human satellite III repetitive sequence with 43 and 56 of GGAAT repeats on the left- and right-hand side, respectively. Although the findings on the viral-cellular junction in HAGS 2.1 cells cannot explain the liver tumorigenesis, the current study shows that by choosing the nearest restriction site, which can be determined by conventional PCR rather than using a unique site within the integrated viral sequence to do IPCR, gives a higher successful rate for cloning and the subsequent analysis of the viral-cellular junctions.

Differences in mutant p53 protein stability and functional activity in teniposide-sensitive and -resistant human leukemic CEM cells

We examined p53 protein stability and DNA damage-induced p53-dependent responses in a human leukemic CEM cell line and two teniposide-resistant sublines, CEM/VM-1 and CEM/VM-1-5 ( approximately 40 and 400-fold resistant to teniposide, respectively). Although all cell lines contain the same p53 mutations at codons 175 (Arg-->His) and 248 (Arg-->Gln), the constitutive levels of p53 were progressively increased with the resistance of the cells to teniposide. By pulse-chase experiments, we found that the half-lives of mutant p53 protein were approximately 12, 17, and >30 h in CEM, CEM/VM-1, and CEM/VM-1-5 cells, respectively. The prolonged half-lives of p53 in these cells is consistent with the fact that the protein harbors the indicated mutations. Of note, however, is the fact that the increased p53 protein half-lives in the two drug-resistant cell lines corresponds to a proportional decrease in MDM2 protein levels but an increase in p53-MDM2 binding interactions. This suggests that MDM2-mediated p53 degradation may be altered in our leukemic cell lines. The DNA damage-induced p53 response is fully functional in the drug-sensitive CEM cells containing a mutant p53, but this pathway is attenuated in the drug-resistant cells. Specifically, while the mutant p53 was phosphorylated at serine-15 in response to ionizing radiation in all these cell lines, mutant p53 induction in response to teniposide or ionizing radiation and induction of the p53-target genes, p21 and GADD45 only occurred in the drug-sensitive CEM cells. As assessed by MTT cytotoxicity assay, CEM cells were also significantly more sensitive to ionizing radiation, compared to the drug-resistant cell lines, and this correlated with p53 induction. Collectively, these results suggest that changes in constitutive mutant p53 protein levels, p53-MDM2 binding interactions, and altered regulation of the DNA damage-inducible p53-dependent pathway may play a role in drug- and radiation-responsiveness in these cells.

Prognostic role of pericardial fluid cytology in cardiac tamponade associated with non-small cell lung cancer

BACKGROUND AND STUDY OBJECTIVES

Cardiac tamponade is a life-threatening complication of non-small cell lung cancer (NSCLC). Malignant pericardial effusion signifies advanced disease, but the significance of a negative pericardial fluid cytology in patients with advanced lung cancer is still controversial. The differential diagnosis of cytology-negative pericardial effusion is difficult and sometimes impossible. The purpose of this study is to determine the prognostic role of pericardial fluid cytology in patients with NSCLC and cardiac tamponade.

DESIGN

Retrospective review of patients with concurrent NSCLC and cardiac tamponade over a 10-year period.

METHODS AND RESULTS

Eighty-two patients were included in this study. Pericardial fluid cytology was positive in 60 patients and negative in 22 patients. The overall median survival was 74.5 days, and 1-year survival was 7.3%, with no survival difference between the two groups (p = 0.2506). However, there was a significant survival difference after different treatment strategies. Patients receiving systemic chemotherapy survived longer than those receiving local therapy (p<0.001), and these patients, in turn, survived longer than those receiving supportive treatment (p<0.001).

CONCLUSIONS

When patients have concurrent advanced NSCLC and cardiac tamponade, the most likely cause of the pericardial effusion is the cancer itself, regardless of the results of the cytologic examination. Our results suggest that systemic chemotherapy might prolong survival in such patients, but further prospective, randomized study is necessary.