OBJECTIVETo review the clinical features and laboratory investigations of ciguatera patients in Hong Kong between 2004 and 2007 in order to show the timely sampling of implicated fish from ciguatera victims and application of validated mouse bioassay for confirming suspected clinical cases of ciguatera.

METHODSDiagnosis of the ciguatera victims was based on history of coral fish consumption and clinical presentations stated in official guidelines for clinical diagnosis of ciguatera fish poisoning in Hong Kong. Food remnants of coral fish samples were collected swiftly from ciguatera victims between 2004 and 2007 for ciguatoxins (CTXs) analysis.

RESULTSMajor clinical symptoms in ciguatera patients included gastrointestinal and neurological effects including limb numbness and diarrhoea, which developed at 0.5 to 15 hours after consumption of fish. In most cases, neurological symptoms were more common than gastrointestinal symptoms. A broad range of attack rate (10%-100%) was observed in each ciguatera outbreak. Validated mouse bioassay on ether extracts of the food remnant samples confirmed that all were CTXs-positive (<0.5 - 4.3 MU/20 mg ether extract) and directly linked to the corresponding ciguatera cases.

CONCLUSIONConsistency between clinical and laboratory analysis for ciguatera poisoning illustrates the application of laboratory mouse bioassay in a timely fashion for confirming ciguatera poisoning cases and implementing effective public health measures. With further improvement in laboratory techniques, features of ciguatera fish poisoning cases can be better defined. Further studies are needed to determine the risk of each class of CTXs (Pacific-, Indian- and Caribbean-CTXs) in Hong Kong.

Animals ; Biological Assay ; Ciguatera Poisoning ; blood ; diagnosis ; epidemiology ; Ciguatoxins ; analysis ; Disease Outbreaks ; Fishes ; Gastrointestinal Diseases ; blood ; diagnosis ; epidemiology ; Hong Kong ; epidemiology ; Humans ; Mice ; Nervous System Diseases ; blood ; diagnosis ; epidemiology ; Prevalence ; Public Health ; Risk Factors ; Time Factors

OBJECTIVETo develop an ICR (female) mouse bioassay (MBA) for toxicity confirmation and evaluation of neurotoxins (brevetoxins)-contaminated shellfish.

METHODSBrevetoxins (BTX-B) as a causative agent of neurotoxic shellfish poisoning (NSP) under different shellfish matrices were intraperitoneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determination of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinations. Detection rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared.

RESULTSBTX-B could be detected in shellfish tissues at concentration of 50-400 μg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit (80 μg/100 g shellfish tissues). The LD50 identified was 455 mg/kg for BTX-B under general shellfish matrices (excluding oyster matrices) dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentation in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinations, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit.

CONCLUSIONThe two ELISA analyses agree favorably (correlation coefficient, r³⋝0.96; Student's t-tests, P>0.05) with the developed bioassay.

Animals ; Biological Assay ; Calibration ; Female ; Marine Toxins ; toxicity ; Mice ; Mice, Inbred ICR ; Oxocins ; toxicity ; Shellfish ; analysis

Purpose: NUF2 has been implicated in multiple cancers recently, suggesting NUF2 may play a role in the common tumorigenesis process. In this study, we aim to perform comprehensive meta-analysis of NUF2 expression in the cancer types included in the Cancer Genome Atlas (TCGA). Materials and Methods: RNA-sequencing data in 31 cancer types in the TCGA data and 11 independent datasets were used to examine NUF2 expression. Silencing NUF2 using targeting shRNAs in hepatocellular carcinoma (HCC) cell lines was used to evaluate NUF2’s role in HCC in vitro and in vivo. Results: NUF2 up-regulation is significantly observed in 23 out of the 31 cancer types in the TCGA datasets and validated in 13 major cancer types using 11 independent datasets. NUF2 overexpression was clinically important as high NUF2 was significantly associated with tumor stages in eight different cancers. High NUF2 was also associated with significantly poorer patient overall survival and disease-free survival in eight and six cancers, respectively. We proceeded to validate NUF2 overexpression and its negative association with overall survival at the protein level in an independent cohort of 40 HCC patients. Compared to the non-targeting controls, NUF2 knockdown cells showed significantly reduced ability to grow, migrate into a scratch wound and invade the 8 μm porous membrane in vitro. Moreover, NUF2 knockdown cells also formed significantly smaller tumors than control cells in mouse xenograft assays in vivo. Conclusion NUF2 up-regulation is a common feature of many cancers. The prognostic potential and functional impact of NUF2 up-regulation warrant further studies.

In order to evaluate the performance of a molecular Hain line probe assay (Hain LPA) for rapid detection of rifampicin and isoniazid resistance of Mycobacterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing (DST). The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.
China ; Genotyping Techniques ; methods ; Humans ; Isoniazid ; pharmacology ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Rifampin ; pharmacology ; Tuberculosis, Multidrug-Resistant ; diagnosis ; microbiology