The protective effect of Bdellovibrio-and-like organisms (BALO) on tilapia fish fillets against Salmonella enterica ssp. enterica serovar Typhimurium

AIMS

To characterize freshwater Bdellovibrio-and-like organisms (BALO) isolated in China and examine their potential in controlling growth of Salmonella enterica ssp. enterica serovar Typhimurium on tilapia fillets.

METHODS AND RESULTS

Four BALO isolates were recovered from a pond in Yanzhou of Shandong province, China, with Salm. Typhimurium as prey using double-layer agar method. Partial 16S rDNA sequencing analysis identified BD2GL, BD5GL and BDXGL as Bdellovibrio bacteriovorus and BD2GS as a Peredibacter sp. Lysis experiments on 32 potentially pathogenic strains revealed that BALO lysis rates are in the range of 56.3-65.6%. On the five Salmonella strains tested, only BD2GS achieved 100% lysis rate. When applied on tilapia fillets against Salm. Typhimurium, BD2GS showed its growth control potential. Cell increments of Salm. Typhimurium were significantly lower (P < 0.05) in two BD2GS-treated groups compared to control and low-dose group (BD2GS to prey ratio, 1 : 1) was more effective than high-dose group (BD2GS to prey ratio, 10 : 1) in controlling Salm. Typhimurium growth.

CONCLUSIONS

Results of this study indicated that BD2GS could control Salm. Typhimurium growth on tilapia fillets.

SIGNIFICANCE AND IMPACT OF THE STUDY

BALO could be used as a live protective culture in controlling bacterial growth and ensure food safety.

A noninvasive imaging approach to assess plaque severity: the carotid atherosclerosis score

BACKGROUND AND PURPOSE

The presence of IPH and/or FCR in the carotid atherosclerotic plaque indicates a high-risk lesion. The aim of this multicenter cross-sectional study was to establish the characteristics of lesions that may precede IPH and/or FCR. We further sought to construct a CAS that stratifies carotid disease severity.

MATERIALS AND METHODS

Three hundred forty-four individuals from 4 imaging centers with 16%-99% carotid stenosis by duplex sonography underwent carotid MR imaging. In approximately 60% of the study sample (training group), multivariate analysis was used to determine factors associated with IPH and FCR. Statistically significant parameters identified during multivariate analysis were used to construct CAS. CAS was then applied to the remaining arteries (40%, test group), and the accuracy of classification for determining the presence versus absence of IPH or, separately, FCR was determined by ROC analysis and calculation of the AUC.

RESULTS

The maximum proportion of the arterial wall occupied by the LRNC was the strongest predictor of IPH (P < .001) and FCR (P < .001) during multivariate analysis of the training group. The subsequently derived CAS applied to the test group was an accurate classifier of IPH (AUC = 0.91) and FCR (AUC = 0.93). Compared with MRA stenosis, CAS was a stronger classifier of both IPH and FCR.

CONCLUSIONS

LRNC quantification may be an effective complementary strategy to stenosis for classifying carotid atherosclerotic disease severity. CAS forms the foundation for a simple imaging-based risk-stratification system in the carotid artery to classify severity of atherosclerotic disease.

The clinicopathological significance of BUBR1 overexpression in hepatocellular carcinoma

BACKGROUND AND AIMS

BUBR1 is a key component of the mitotic spindle checkpoint, and its roles in human cancers are controversial and unclear. The aim of this study was to investigate the clinicopathological significance of BUBR1 expression in hepatocellular carcinoma (HCC).

METHODS

The BUBR1 protein and its mRNA levels were measured in 58 HCCs, nine high-grade dysplastic nodules and their paired non-tumorous liver tissues by quantitative real-time polymerase chain reaction (qPCR) and western blot, respectively. In addition, immunochemical analysis of the BUBR1 protein was performed in 458 HCCs and 46 dysplastic nodules, and the clinicopathological significance of the BUBR1 expression was evaluated.

RESULTS

The BUBR1 expression at both mRNA and protein levels was elevated in two of nine high-grade dysplastic nodules and in 37 of 58 (64%) HCCs. BUBR1 was overexpressed in 207 of 458 (45%) HCCs by immunohistochemistry. Intriguingly, high expression of the BUBR1 was correlated with larger tumour size, higher histological grade, advanced pathological stage, and poor overall and recurrence-free survival. There was a higher frequency of BUBR1 overexpression in cases with positive serum HBsAg than those with negative HBsAg. Moreover, BUBR1 overexpression was associated with P53 staining and high Ki67 labelling indices in HCC tissues.

CONCLUSIONS

BUBR1 was overexpressed in about 45% HCCs, and its overexpression may be a relative lately event in HCC progression. Overexpression of BUBR1 was associated with worse prognosis and is a potential prognostic factor for patients with HCC.

Marginal hazards model for case-cohort studies with multiple disease outcomes

Case-cohort study designs are widely used to reduce the cost of large cohort studies while achieving the same goals, especially when the disease rate is low. A key advantage of the case-cohort study design is its capacity to use the same subcohort for several diseases or for several subtypes of disease. In order to compare the effect of a risk factor on different types of diseases, times to different events need to be modelled simultaneously. Valid statistical methods that take the correlations among the outcomes from the same subject into account need to be developed. To this end, we consider marginal proportional hazards regression models for case-cohort studies with multiple disease outcomes. We also consider generalized case-cohort designs that do not require sampling all the cases, which is more realistic for multiple disease outcomes. We propose an estimating equation approach for parameter estimation with two different types of weights. Consistency and asymptotic normality of the proposed estimators are established. Large sample approximation works well in small samples in simulation studies. The proposed methods are applied to the Busselton Health Study.

Characterization of a major colon cancer susceptibility locus (Ccs3) on mouse chromosome 3

Treatment of mice with the carcinogen azoxymethane (AOM) induces a number of lesions in the colon, including hyperplastic lesions, as well adenomas and carcinomas in situ. Inbred strains of mice show different responses to AOM-induced carcinogenesis. A/J mice are highly susceptible and develop a greater number of hyperplastic lesions and tumors (15-70 tumors per mouse) than resistant C57BL/6J mice (0-6 tumors per mouse). Susceptibility to AOM-induced tumors segregates as a co-dominant trait in (A x B6)F1 hybrids. Using a set of 23 AcB and BcA recombinant congenic mouse strains derived from A/J (susceptible) and B6 (resistant) parents, we observed that the number of hyperplastic lesions and tumors induced by AOM was under different genetic controls in AcB/BcA strains. The multiplicity of AOM-induced tumors is controlled by a major locus that we have mapped on the distal portion of chromosome 3, to which we have given the temporary designation colon cancer susceptibility locus 3 (Ccs3). B6 and A/J alleles at Ccs3 are associated with resistance and susceptibility, respectively. Haplotype analysis in key informative AcB/BcA strains restricts the size of the Ccs3 locus to a 14 Mb segment that contains 94 annotated genes. The expression level of all these genes in normal colon has been established by transcript profiling with microarrays, and has led to the identification of a subset of positional candidates that are expressed at high levels in this tissue. The 4q and 1p human chromosomal segments sharing syntenic homology with the mouse Ccs3 segment are known to be associated with inflammatory bowel diseases and colorectal tumors in humans, suggesting that the study of the mouse Ccs3 locus may help further the pathogenesis of these human conditions.

Prevention of excess gain

Obesity prevention trials are designed to promote healthy weight. The success of these trials is often assessed using one of three metrics--means, incidence or prevalence. In this study, we point out conceptual shortcomings of these metrics and introduce an alternative that we call 'excess gain'. A mathematical demonstration using simulated data shows a scenario in which the statistical power of excess gain compares favorably with that of incidence and prevalence. Prevention of excess gain communicates an easily understood public health message that is applicable to all individuals regardless of weight status.

Osteopontin induces angiogenesis through activation of PI3K/AKT and ERK1/2 in endothelial cells

Angiogenesis is a key step in tumor growth and metastasis. The mechanism by which osteopontin (OPN) induces the angiogenesis of endothelial cells remains unclear. Here, we show that OPN confers cytoprotection through the activation of the PI3K/Akt pathway with subsequent upregulation of Bcl-xL and activation of nuclear factor-kappaB. OPN enhances the expression of vascular endothelial growth factor (VEGF) through the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). In turn, OPN-induced VEGF activates PI3K/AKT and the ERK1/2 pathway as a positive feedback signal. Blocking the feedback signal by anti-VEGF antibody, PI3-kinase inhibitor or ERK inhibitor can partially inhibit the OPN-induced human umbilical vein endothelial cell (HUVEC) motility, proliferation and tube formation, while blocking the signal by anti-OPN or anti-alphavbeta3 antibody completely abrogates the biological effects of OPN on HUVECs. In addition, blood vessel formation is also investigated in vivo. The antiangiogenesis efficacy of anti-OPN antibody in vivo is more effective than that of anti-VEGF antibody, which only blocks the feedback signals. These data show that OPN enhances angiogenesis directly through PI3K/AKT- and ERK-mediated pathways with VEGF acting as a positive feedback signal. The results suggest that OPN might be a valuable target for developing novel antiangiogenesis therapy for treatment of cancer.

Significance of phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT), and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein expression in gynaecomastia

This study was designed to investigate the pathogenesis of gynaecomastia by measuring phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein in breast tissue specimens from 68 patients with gynaecomastia and 24 normal male controls using immunohistochemical staining. The gynaecomastia cases were divided into three different histological types: florid, intermediate and fibrous. The PTEN, MGMT and DNA-PKcs proteins were detected in both gynaecomastia and normal breast tissue, but the levels of immunohistochemical staining of each protein were significantly lower in gynaecomastia breast tissue than in normal breast tissue. There were also significant differences in the levels of immunohistochemical staining for the three proteins according to gynaecomastia histological type. These results suggest that abnormally low levels of PTEN, MGMT and DNA-PKcs protein in gynaecomastia breast tissue may play a role in the development of gynaecomastia. Further research is required to elucidate fully their individual roles in the pathophysiology of gynaecomastia.