Computed Diffusion-Weighted Images of Rectal Cancer: Image Quality, Restaging, and Treatment Response after Neoadjuvant Therapy.

BACKGROUND: Computed diffusion-weighted images (cDWI) of random b value could be derived from acquired DWI (aDWI) with at least two different b values. However, its comparison between aDWI and cDWI images in locally advanced rectal cancer (LARC) patients after neoadjuvant therapy (NT) is needed. PURPOSE: To compare the cDWI and aDWI in image quality, restaging, and treatment response of LARC after NT. STUDY TYPE: Retrospective. POPULATION: Eighty-seven consecutive patients. FIELD STRENGTH/SEQUENCE: 3.0 T/DWI. ASSESSMENT: All patients underwent two DWI sequences, including conventional acquisition with b = 0 and 1000 s/mm2 (aDWIb1000 ) and another with b = 0 and 700 s/mm2 on a 3.0-T MR scanner. The images of the latter were used to compute the diffusion images with b = 1000 s/mm2 (cDWIb1000 ). Four radiologists with 3, 4, 14, and 25 years of experience evaluated the images to compare the image quality, TN restaging performance, and treatment response between aDWIb1000 and cDWIb1000 . STATISTICAL TESTS: Interclass correlation coefficients, weighted κ coefficient, paired Wilcoxon, and McNemar or Fisher test were used. A significance level of 0.05 was used. RESULTS: The cDWIb1000 images were superior to the aDWIb1000 ones in both subjective and objective image quality. In T restaging, the overall diagnostic accuracy of cDWIb1000 images was higher than that of aDWIb1000 images (57.47% vs. 49.43%, P = 0.289 for the inexperienced radiologist; 77.01% vs. 63.22%, significant for the experienced radiologist), with better sensitivity in determining ypT0-Tis tumors. Additionally, it increased the sensitivity in detecting ypT2 tumors for the inexperienced radiologist and ypT3 tumors for the experienced radiologist. N restaging and treatment response were found to be similar between two sequences for both radiologists. DATA CONCLUSION: Compared to aDWIb1000 images, the computed ones might serve as a wise approach, providing comparable or better image quality, restaging performance, and treatment response assessment for LARC after NT. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Unveiling the role of hypoxic macrophage-derived exosomes in driving colorectal cancer progression.

The crosstalk between tumor cells and macrophages under hypoxic conditions has been acknowledged as a pivotal determinant in the progression of colorectal cancer (CRC). Previous research has underscored the significance of exosomes derived from hypoxic tumor cells in facilitating tumor progression through inducing the polarization of macrophages towards the M2-like phenotype. The precise influence of hypoxic macrophage-derived exosomes (HMDEs) on the progression of CRC has not yet been fully elucidated. The objective of this study was to investigate the role of HMDEs in the progression of CRC. We discovered that there was an elevated release of exosomes derived from macrophages in hypoxic conditions. Additionally, the hypoxia-induced macrophage-derived exosomes played a crucial role in promoting the progression of CRC. We have also demonstrated that HMDEs have the ability to induce cell cycle transition and inhibit cell apoptosis, thereby promoting the growth of CRC cells. Furthermore, the underlying molecular mechanisms of these effects have been identified. The overexpression of Hif-1α results in its direct interaction with distinct regions (-521- -516 bp and -401- -391 bp) of the Hsp90 promoter during hypoxic circumstances. This binding event led to the overexpression of Hsp90 and the subsequent elevation of Hsp90 protein levels within HMDEs. Importantly, the crucial interaction between Hsp90 and Lats1 resulted in the deactivation of Lats1 and the inhibition of Yap phosphorylation. Ultimately, this series of events lead to the deactivation of the Hippo signaling pathway. Our in vivo and in vitro studies presented compelling evidence for the crucial role of hypoxic macrophage-derived exosomal Hsp90 in promoting CRC progression through the inhibition of the Hippo signaling pathway. These findings represented a significant advancement in our comprehension of the complex interplay between macrophages and CRC cells under hypoxic conditions.

Perfect sampling from spatial mixing.

We introduce a new perfect sampling technique that can be applied to general Gibbs distributions and runs in linear time if the correlation decays faster than the neighborhood growth. In particular, in graphs with subexponential neighborhood growth like ℤ d , our algorithm achieves linear running time as long as Gibbs sampling is rapidly mixing. As concrete applications, we obtain the currently best perfect samplers for colorings and for monomer-dimer models in such graphs.

[The application and epidemiological research of xTAG GPP multiplex PCR in the diagnosis of infectious diarrhea].

OBJECTIVE: To investigate the application value of xTAG (®) gastrointestinal pathogen panel (xTAG9(®) GPP) multiplex PCR in the early diagnosis of infectious diarrhea, and understand the epidemiology of intestinal diarrhea pathogens. METHODS: Five hundred and ninety two specimens were collected in outpatient of Tongren Hospital, Capital Medical University, from 1st Oct 2013 to 30th Sep 2014, comparing the xTAG(®) GPP multiplex PCR assay with the traditional methods (culture, rapid enzyme immunoassay chromatography, microscopic examination, Real-time PCR) and mading the statistical analysis. RESULTS: The positive rate of 592 patients with diarrhea specimens was 47.8% (283/592), the proportion of male and female was 1: 1.02, the average age was 31years. The virus detection rate was 18.1%, Rotavirus A was the most common organism detected (8.8%), concentrated in winter, popular in children.Secondly,Norovirus GI/GII (8.4%),Adenovirus 40/41 was five cases. The positive rate of bacteria was 35.5%, Enterotoxigenic E.coli (8.4%, 50/592) was most frequently detected in summer, common in young adults. The other pathogens were Campylobacter 7.7%, Salmonella 7.0%, Clostridium difficile toxinA/B 3.5%, Shigella 3.3%,E.coli O157 3.3% and Shiga toxin-producing E.coli LT/ST 1.7%.None of Yersinia enterocolitica and Vibrio cholerae was detected. There were ten samples with parasitic (1.7%), five samples were positive for Cryptosporidium, three for Entamoeba histolytica and two for Giardia. All of them did not have obvious distribution followed by season and population. Totally 242(40.8%) infected specimens with single pathogen were detected. There were 41 (6.9%) co-infections samples, including two pathogens 36 cases (6.1%), three pathogens in 5 cases (0.8%). CONCLUSIONS: xTAG(®) GPP multiplex PCR is simple, sensitive, specific and can be used as a quick way to diagnose the infectious diarrhea. Diarrhea pathogen has significant characteristics with the season and crowd.

[Clinical value of viral detection of liquid chip method in community-acquired pneumonia].

OBJECTIVE: To evaluate the clinical value of viral detection of liquid chip method in community-acquired pneumonia (CAP). METHODS: A total of 342 swabs were collected from 171 patients of community-acquired pneumonia from October 2013 to September 2014. The methods of xTAG(RVP) and Seeplex RV15 ACE were employed to detect respiratory viruses. And traditional methods of indirect immunofluorescence and specific antigen were used for comparison. All results were validated by realtime-PCR and statistically analyzed. RESULTS: Of 171 CAP patients with an average age of 49.17 years, 35.7% (61/171) were virus positive.Influenza A (FluA), influenza B (FluB), respiratory syncytial virus (RSV), human rhinovirus (HRV) and human metapneumovirus (hMPV) accounted for 90.5% of all detected viruses. The detection rates of mouth swabs and nasopharyngeal swabs were 31.6% and 33.9% respectively. Two specimen types showed no significant differences (Kappa = 0.714, P < 0.001; McNemar χ(2) = 0, P = 1.000). The positive rates of viral detection by xTAG(RVP) and Seeplex RV15 were 32.5% and 29.5% respectively. And the consistence rate of results was up to 85.4% (292/342) (Kappa = 0.66). The positive rate of traditional methods was 14.0%.However, xTAG(RVP) had a higher sensitivity (93.3%), higher consistence rate (92.4%) and negative predictive value (96.9%) compared with Seeplex RV15 and traditional methods. Also xTAG(RVP) had a high consistent rate of realtime-PCR (Kappa = 0.83). CONCLUSIONS: Liquid chip is superior to other detection methods. And it may be used routinely for viral detection of CAP.