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Shiga toxin-producing Escherichia coli (STEC) are emerging as a significant source of foodborne infectious disease in the developed world. Multistate outbreaks of E. coli O157 and non-O157 serogroups in the United States are facilitated by the centralization of food processing and distribution. Our ability to recognize the clonality of these clusters has been advanced by developments in molecular detection techniques and in the establishment of active surveillance practices. These studies have helped identify important risk factors for both sporadic and outbreak STEC infection, allowing us to develop appropriate prevention strategies. Identification of these factors is of critical importance because of the lack of adequate treatments available. This brief review of the literature discusses major developments in the epidemiology, pathogenesis, diagnosis, treatment, and prevention of STEC disease published in the past few years.  相似文献   
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To develop a molecular pattern that might help in understanding carcinogenesis of postcricoid carcinoma (PCC) on top of Plummer-Vinson syndrome (PVS) in a prospective controlled study. Twenty-four patients with PVS were diagnosed and followed up over a 4 year period, during which eight of them showed malignant change to PCC. Twenty volunteers free of neoplastic diseases were included as a control group. In the two groups, DNA extraction from mononuclear peripheral blood cells, and analysis of loss of heterozygosity (LOH) and microsatellite instability (MSI) using six paired simple tandem repeats (STRs) primers were done. The molecular weight of each STRs locus was scored and statistical correlations were performed. LOH occurred in 55.6 and 72.9% of PVS and PCC cases compared to 25% of control group. At loci D17S695, D9S753 and D9S171, LOH occurred in 54.2, 66.7, and 70.8% of PVS cases; and in 62.5% of PCC cases for each locus compared to 15, 25 and 45% of control cases. D3S1286 and CFS1-R displayed the highest frequency of LOH in PCC (100% for each) while recorded in 58.3 and 33.3% in PVS compared to 30 and 0% in control cases. Certain genetic events tend to occur as early and late events in malignant change of PVS to PCC. Detection of these events may help in understanding carcinogenesis and in early detection of malignancy. CFS1-R is the most informative marker of tumor progression.  相似文献   
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The optimum moderating geometry using an (241)Am-Be neutron source for detecting landmines has been investigated. The experimental setup composed of a Pb cylindrical shell enclosing the neutron source, embedded in a fixed-size high-density polyethylene cylinder with a variable thickness of the upper and lower moderator/reflector. According to the fact that the increased flux of thermal neutrons in the mine position yields increased prompt gamma rays, some groups of experiment have been done to measure several moderator configurations' responses, replacing a thermal neutron detector with the landmine and counting the neutron capture events.  相似文献   
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Purpose

To compare the efficacy of three chemoprophylaxis approaches in prevention of post-transrectal biopsy infectious complications (TBICs).

Methods

Patients were randomly assigned to receive ciprofloxacin 3 days 500 mg B.I.D 3 days starting the night prior to biopsy (standard prophylaxis), augmented prophylaxis using ciprofloxacin and single preprocedure shot of 160 mg gentamicin IM (augmented prophylaxis) and rectal swab culture-based prophylaxis (targeted prophylaxis). Patients were assessed 2 weeks prior to biopsy, at biopsy and 2 weeks after. Primary end point was occurrence of post-TBICs that included simple UTI, febrile UTI or sepsis. Secondary end points were post-biopsy change in the inflammatory markers (TLC, ESR and CRP), unplanned visits, hospitalization and occurrence of fluoroquinolones resistance (FQ-R; bacterial growth on MacConkey agar plate with 10 μg/ml ciprofloxacin) in the fecal carriage of screened men.

Results

Between April/2015 and January/2017, standard, augmented and targeted prophylaxes were given to 163, 166 and 167 patients, respectively. Post-TBICs were reported in 43 (26%), 13 (7.8%) and 34 (20.3%) patients following standard, augmented and targeted prophylaxes protocols, respectively (P?=?0.000). Post-TBICs included UTI in 23 (4.6%), febrile UTI in 41 (8.2%) and sepsis in 26 (5.2%) patients. Significantly lower number of post-biopsy positive urine culture was depicted in the augmented group (P?=?0.000). The number of biopsy cores was statistically different in the three groups (P?=?0.004). On multivariate analysis, augmented prophylaxis had independently lower post-TBICs (OR 0.2, 95% CI 0.1–0.4, P?=?0.000) when compared with the other two groups regardless of the number of biopsy cores taken (OR 1.07, 95% CI 0.95–1.17, P?=?0.229). Post-biopsy hospitalization was needed in four (2%), one (0.6%) and ten (6%) patients following standard, augmented and targeted prophylaxes, respectively (P?=?0.014). However, sepsis-related hospitalization was not statistically different. Post-biopsy changes in the inflammatory markers were significantly less in augmented prophylaxis (P?<?0.05). FQ-R was depicted in 139 (83.2%) of the screened men.

Conclusion

Augmented prophylaxis with single-dose gentamicin is an effective and practical approach. Targeted prophylaxis might be reserved for cases with contraindication to gentamicin.
  相似文献   
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