Planktonic bacteria in white shrimp (Litopenaeus vannamei) and channel catfish (Letalurus punetaus) aquaculture ponds in a salt-alkaline region

Aquaculture in salt-alkaline regions is encouraged in China, and culture of many aquatic species has been introduced into these areas. In this study, we cultured two species, white shrimp (Litopenaeus vannamei) and channel catfish (Letalurus punetaus) separately in aquaculture ponds in a salt-alkaline region in northwest China and assessed the impacts of the aquaculture operations on the planktonic bacterial community in the culture ponds. Culture of both species decreased the planktonic bacterial diversity and altered the bacterial community structure in the aquaculture ponds compared with the source water. Among the 10 dominant bacterial phyla, 8 were significantly correlated with environmental parameters; the exception was Actinobacteriota, the most dominant phylum, and Firmicutes. Proteobacteria and Bacteroidota abundances showed significant positive correlations with alkalinity, whereas Patescibacteria, Cyanobacteria, Planctomycetota, and Verrucomicrobiota abundance were positively correlated with salinity. Linear regression analysis showed that alkalinity was positively correlated with bacterial beta diversity and salinity was negatively correlated with that. In addition, white shrimp aquaculture significantly lowered the alkalinity, which suggests that culture of this species in inland salt-alkaline regions is a potential dealkalization solution.

[Development of a fluorescent recombinase-aided isothermal amplification-based nucleic acid assay for detection of Leishmania]

OBJECTIVE

To develop a fluorescent recombinase-aided isothermal amplification (RAA)-based nucleic acid assay for detection of Leshimania.

METHODS

Specific primers and probes were designed targeting Leishmania internal transcribed spacer 1 (ITS1) gene for RAA assay, and a fluorescent RAA assay was developed for detection of Leishmania following screening of primer pairs and optimization of primer and probe concentrations. The sensitivity of RAA assay for detection of Leishmania was evaluated using recombinant plasmid containing Leishmania ITS1 gene sequences at different copies and Leshimania genomic DNA at different concentrations as templates, and the specificity of RAA assay for detection of Leishmania was evaluated using the genomic DNA of transfusion-transmitted parasites, including Babesia microti, Toxoplasma gondii, Plamodium vivax, P. ovale, P. falciparum, P. malariae, L. donovani and L. infantum.

RESULTS

After the optimal primer pair was screened from 9 pairs of primer combinations, the final primer and probe concentrations were optimized as 0.3 μmol/L and 0.08 μmol/L, respectively. Nucleic acid detection of Leishmania was completed by the fluorescent RAA assay at an isothermal temperature of 39 °C within 20 min. Remarkable florescent signals were seen within 5 min following RAA detection of genomic DNA of L. donovani and L. infantum, and no cross-reactions were observed with B. microti, T. gondii, P. vivax, P. ovale, P. falciparum or P. malariae. The lowest limitation of detection of the fluorescent RAA assay was 10 copies/μL recombinant plasmid containing Leishmania ITS1 gene sequences and 1 fg/μL Leishmania genomic DNA.

CONCLUSIONS

A rapid, simple, sensitive and specific fluorescent RAA assay is successfully developed for detection of L. donovani and L. infantum, which is effective for field screening of leishmaniasis.

Cloning, genome structure and expression analysis of MHC class I gene in Korean quail

1. The major histocompatibility complex (MHC) is a highly polymorphic region of the genome essential to immune responses and animal health. However, avian MHC genetic structure is different from that of mammals. In this study, the structure and expression of Korean quail MHC class I gene was analysed.2. The quail MHC gene consisted of eight exons and seven introns. The open reading frame of the cDNA was 353 amino acids, and the molecular weight was about 38.91 kDa. Exons 1 and 2 coded for leading peptides and alpha 1 regions, respectively. Exons 3 and 4 encoded alpha 2 and alpha 3 regions. Exons 5 to 8 coded for connecting peptides and transmembrane regions/cytoplasmic regions (TM/CY). The Korean quail MHC class I amino acid sequence shared 87% to 99% homology with Japanese quail and 71% to 75% with chicken. The amino acid shared 40% and 43% homology with humans and mice, respectively.3. Real-time quantitative PCR showed that MHC-I was highly expressed in immune tissues such as the bursa of Fabricius. Moreover, the constructed evolutionary tree was consistent with accepted evolutionary pathways.4. MHC-I is closely related to the host's immune system, and these findings may help to better understand the role of Korean quail MHC-I in the immune system.

Esophagectomy combined with off-pump coronary artery bypass grafting through left posterolateral incision is safe and feasible for esophageal cancer associated with coronary artery disease

Controversy still exists as to whether surgical treatment has any impact on the long-term survival of esophageal cancer (EC) patients with coronary artery disease treated with curative esophagectomy combined with off-pump coronary artery bypass grafting (OPCABG). Therefore, the aim of this study was to introduce and assess the effect of esophagectomy combined with OPCABG on both short- and long-term outcomes. From January 2010 to January 2015, 1428 EC or esophagogastric junction cancer patients underwent surgical treatment at Henan Chest Hospital, Zhengzhou, China. The clinical data of 25 patients who underwent EC resection through a left thoracotomy following OPCABG and the perioperative characteristics and follow-up results were analyzed. The majority of the patients were male, and the EC stage was predominantly cT2N0-1M0 II. The most common pathological types were squamous cell carcinoma. The EC surgeries consisted of 15 chest anastomosis procedures and 10 cervical anastomosis procedures with aortocoronary graft implantation (mean: 2.36 grafts per patient). The mean total operative time was 330.8 ± 83.5 minutes. The median intensive care unit and hospital lengths of stay were 1.72 and 21.16 days, respectively. Resection without macroscopic residual disease (R0) was achieved in all of the patients. The most frequent complications included pulmonary infections (24%), arrhythmias (24%), pleural effusion (12%), and esophageal anastomotic leakage (8%). There were no postoperative deaths or myocardial infarctions within 30 days after the surgery. The overall 1-, 3-, and 5-year survival rates were 88%, 40%, and 24%, respectively, with a median survival time of 43 months. In the short-term, radical resection of EC following OPCABG is a safe and feasible treatment with low postoperative mortality rates. In the long-term, simultaneous surgery is acceptable and is associated with favorable overall and disease-free survival.

Modified anterior midline approach to treat hyperextension bicondylar tibial plateau fractures: Surgical technique and clinical experience with 18 cases

BACKGROUND

We evaluated the modified anterior midline approach and its efficacy for hyperextension bicondylar tibial plateau (HEBTP) fractures.

METHODS

From 2015 to 2019, 18 patients with HEBTP fractures with just little posterior cortical displacement were treated using the modified anterior midline approach. The operative protocols are fully described in this article, and the following parameters: articular step-off height (ASH), posterior tibial slope angle (pTSA), and medial tibial plateau angle (mTPA) were measured perioperatively and at the final follow-up. We also recorded the Rasmussen score and range of motion (ROM) to assess knee joint function at the final follow-up.

RESULTS

No complications, such as percutaneous nerve damage, infection, skin necrosis, and internal fixation breakage or loosening occurred perioperatively. The mean time for bony union was 13.7 weeks, and the mean preoperative ASH of the anterior cortex was 4.49 mm; this was restored to its normal height after surgery. The mean preoperative pTSA and mTPA were - 5.89° and 81.69°, respectively, compared with 3.89° and 87.91°, respectively, postoperatively. Comparing the postoperative and final follow-up radiographs, there were no significant differences in ASH, pTSA, and mTPA (P < 0.05). The average Rasmussen score was 27.2 (range, 23-29) at the final follow-up. Excellent results were achieved in 14 (77.8%) patients and good in 4 (22.2%) patients. The mean ROM in flexion was 123.2° and 2.9° in extension at the final follow-up.

CONCLUSIONS

This study suggested that the modified anterior midline approach is a reasonable alternative for HEBTP fracture repair.

Spatiotemporal distribution, source apportionment and combined pollution of antibiotics in natural waters adjacent to mariculture areas in the Laizhou Bay, Bohai Sea

The spatiotemporal distribution, source apportionment and combined pollution of 14 antibiotics in natural waters adjacent to mariculture farms of Laizhou Bay in the Bohai Sea were studied. The contribution proportion and quantity of each potential pollution source to antibiotics in natural water bodies were quantitatively described. The correlations between heavy metals and antibiotics and their underlying mechanisms in natural and aquaculture water environment were analyzed. Fourteen antibiotics were detected in natural water and sediment in the coastal area of Laizhou Bay. The maximum concentrations of sulfamethazine and trimethoprim in water reached tens or even hundreds of μg/L in winter. Trimethoprim was the main antibiotic in natural water bodies in winter and summer, and enrofloxacin was the principal antibiotic in sediments. Enrofloxacin, ciprofloxacin and oxytetracycline were detected in all underground water samples; thus, control of these antibiotics needs to be made a priority to mitigate groundwater contamination. PCA-MLR revealed that the potential sources of antibiotics in natural waters of Laizhou Bay include the mariculture wastewater (18.3%), the domestic sewage (63.3%) and the livestock wastewater (18.4%). Therefore, the antibiotic burden of Laizhou Bay was principally from the domestic sewage. In natural water, the concentration of Cu was positively correlated with antibiotics, which might be related to the common sources, the competitive adsorption in sediments and the easy complexation characteristic of Cu and antibiotics. Positive correlations among antibiotics and heavy metals were observed in mariculture sediments, while negative relationships were observed in natural sediments.

RNAi-based immunity in insects against baculoviruses and the strategies of baculoviruses involved in siRNA and miRNA pathways to weaken the defense

Protection against viral infection in hosts concerns diverse cellular and molecular mechanisms, among which RNA interference (RNAi) response is a vital one. Small interfering RNAs (siRNAs), microRNAs (miRNAs) and PIWI interacting RNAs (piRNAs) are primary categories of small RNAs involved in RNAi response, playing significant roles in restraining viral invasion. However, during a long-term coevolution, viruses have gained the ability to evade, avoid, or suppress antiviral immunity to ensure efficient replication and transmission. Baculoviruses are enveloped, insect-pathogenic viruses with double-stranded circular DNA genomes, which encode suppressors of siRNA pathway and miRNAs targeting immune-related genes to mask the antiviral activity of their hosts. This review summarized recent findings for the RNAi-based antiviral immunity in insects as well as the strategies that baculoviruses exploit to break the shield of host siRNA pathway, and hijack cellular miRNAs or encode their own miRNAs that regulate both viral and cellular gene expression to create a favorable environment for viral infection.

[Establishment of a nucleic acid dipstick test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay]

OBJECTIVE

To develop a rapid test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay (RAA) and nucleic acid dipstick test.

METHODS

The S. japonicum SjG28 gene fragment was selected as the target gene fragment, and the primers and fluorescent probe were designed and synthesized. Then, a S. japonicum nucleic acid dipstick test was established. The sensitivity of this dipstick test was evaluated by detecting different copies of recombinant plasmids containing the S. japonicum SjG28 gene fragment and different concentrations of genomic DNA from adult worms of S. japonicum, and the specificity of the dipstick test was evaluated by detecting the genomic DNA from Clonorchis sinensis, S. mansoni, Ancylostoma duodenale, S. haematobium, Babesia and Paragonimus westermani.

RESULTS

The S. japonicum nucleic acid dipstick test based on the S. japonicum SjG28 gene fragment showed the minimum detectable limit of 10 copies/μL of the recombinant plasmid containing the S. japonicum SjG28 gene fragment and the minimum detectable limit of 1 pg/μL of S. japonicum genomic DNA, and the dipstick assay tested negative for the genomic DNA from C. sinensis, S. mansoni, A. duodenale, S. haematobium, Babesia and P. westermani.

CONCLUSIONS

A rapid, simple, and visualized assay is established for detection of S. japonicum specific gene fragments based on RAA and nucleic acid dipstick test.

P–138 When is low quality really low? Should we transfer low-grade blastocysts?

Study question

What is the live birth rate after single, low-grade blastocyst (LGB) transfer?

Summary answer

The live birth rate for LGBs is 28%, ranging between 15–31% for the different inner cell mass (ICM) and trophectoderm (TE) subgroups of LGBs.

What is known already

Live birth rates following LGB transfer are varied and have been reported to be in the range of 5–39%. However, these estimates are inaccurate as studies investigating live birth rates following LGB transfer are inherently limited by sample size (n = 10–440 for LGB transfers) due to LGBs being ranked last for transfer. Further, these studies are heterogenous with varied LGB definitions and design. Collating LGB live birth data from multiple clinics is warranted to obtain sufficient numbers of LGB transfers to establish reliable live birth rates, and to allow for delineation of different LGB subgroups, including blastocyst age and female age.

Study design, size, duration

We performed a multicentre, multinational retrospective cohort study in 9 IVF centres in China and New Zealand from 2012 to 2019. We studied the outcome of 6966 single blastocyst transfer cycles on days 5–7 (fresh and frozen) according to blastocyst grade, including 875 transfers from LGBs (&lt;3bb, this being the threshold typically applied to LGB studies). Blastocysts with expansion stage 1 or 2 (early blastocysts) were excluded.

Participants/materials, setting, methods

The main outcome measured was live birth rate. Blastocysts were grouped according to quality grade: good-grade blastocysts (GGBs; n = 3849, aa, ab and ba), moderate-grade blastocysts (MGBs; n = 2242, bb) and LGBs (n = 875, ac, ca, bc, cb and cc) and live birth rates compared using the Pearson Chi-squared test. A logistic regression analysis explored the relationship between blastocyst grade and live birth after adjustment for the confounders: clinic, female age, expansion stage, and blastocyst age.

Main results and the role of chance

The live birth rates for GGBs, MGBs and LGBs were 45%, 36% and 28% respectively (p &lt; 0.0001). Within the LGB group, the highest live birth rates were for grade c TE (30%) and the lowest were for grade c ICM (19%). The lowest combined grade (cc) maintained a 15% live birth rate (n = 7/48). After accounting for confounding factors, including female age and blastocyst characteristics, the odds of live birth were 2.33 (95% CI = 1.88–2.89) for GGBs compared to LGBs and 1.56 (95% CI = 1.28–1.92) for MGBs compared to LGBs following fresh and frozen blastocyst transfers (p &lt; 0.0001, odds ratios confirmed in exclusively frozen blastocyst transfer cycles). When stratified by individual ICM and TE grade, the odds of live birth according to ICM grade were 1.31 (a versus b; 95% CI = 1.15–1.48), 2.82 (a versus c; 95% CI = 1.91–4.18) and 2.16 (b versus c; 95% CI = 1.48–3.16; all p &lt; 0.0001). The odds of live birth according to TE grade were 1.33 (a versus b; 95% CI = 1.17–1.50, p &lt; 0.0001), 1.85 (a versus c; 95% CI = 1.45–2.34, p &lt; 0.0001) and 1.39 (b versus c; 95% CI = 1.12–1.73, p = 0.0024).

Limitations, reasons for caution

Despite the large multicentre design of the study, analyses of transfers occurring within the smallest subsets of the LGB group were limited by sample size. The study was not randomised and had a retrospective character.

Wider implications of the findings: LGBs maintain satisfactory live birth rates (averaging 28%) in the general IVF population. Even those in the lowest grading tier maintain modest live birth rates (15%; cc). It is recommended that LGBs not be universally discarded, and instead considered for subsequent frozen embryo transfer to maximize cumulative live birth rates.

Trial registration number

Not applicable

[Relationship between clinicopathological features and prognosis of pancreatic ductal adenocarcinoma]

Objective: To investigate the relationship between clinicopathologic features and prognosis of pancreatic ductal adenocarcinoma located in the head of pancreas. Methods: A retrospective study was performed on 169 patients undergoing radical resection for pancreatic head cancer collected in the First Affiliated Hospital with Nanjing Medical University from January 2018 to April 2019. Univariate analysis and multivariate analysis were performed. Results: Patient's age, tumor differentiation, tumor maximum diameter, resection margin (several resection margins including portal vein groove resection margin, posterior resection margin, and uncinate resection margin), number of positive lymph nodes, number of regional lymph node dissected, and some preoperative and postoperative indicators were associated with prognosis (P<0.05). Direct tumor invasion of organs and surrounding tissues, perineural and vascular invasion, pathologic variants etc. had no statistical significance for survival time. Patient's age, maximum tumor diameter, degree of differentiation, uncinate incision margin, number of regional lymph nodes dissected, and preoperative CA19-9 were independent factors affecting prognosis. Patients older than 74 years of age, with tumors larger than 3 cm in diameter, poorly differentiated, less than 7 regional lymph node dissected, positive uncinate margin, and preoperative CA19-9 higher than 1.5×10⁵ U/L were independent risk factors in patients with pancreatic head cancer. Conclusions: Old age, tumor lager than 3 cm, poor differentiation, low examined lymph nodes, direct uncinate margin involvement and (or) with preoperative CA19-9 higher than 1.5×10⁵ U/L are related to poor prognosis of head pancreatic cancer.

BmNPV-induced hormone metabolic disorder in silkworm leads to enhanced locomotory behavior

Many parasites alter the host locomotory behaviors in a way that increases their fitness and progeny transmission. Baculoviruses can manipulate host physiology and alter the locomotory behavior by inducing 'hyperactivity' (increased locomotion) or 'tree-top disease' (climbing high up to the top before dying). However, the detailed molecular mechanism underlying virus-induced this hyperactive behavior remains elusive. In the present study, we showed that BmNPV invaded into silkworm brain tissue, resulting in severe brain damage. Moreover, BmNPV infection disturbed the insect hormone balance. The content of 20-hydroxyecdysone (20E) in hemolymph was much lower during the hyperactive stage, while the dopamine (DA) titer was higher than mock infection. Exogenous hormone treatment assays demonstrated that 20E inhibits virus-induced ELA (enhanced locomotory activity), while dopamine stimulates this behavior. More specificity, injection of dopamine or its agonist promote this hyperactive behavior in BmNPV-infected larvae. Taking together, our findings revealed the important role of hormone metabolism in BmNPV-induced ELA.

Determining the DNA Fingerprinting Profiles of Salmonella Isolates from Raw Poultry Meats and Human Clinical Samples from the Same Geographic Area Using Pulsed-Field Gel Electrophoresis

ABSTRACT

Foods of animal origin, such as poultry, eggs, and pork, are recognized sources of Salmonella infections, but determination of the proportion of foodborne infections associated with various food sources has been challenging. In the present study, 141 Salmonella isolates recovered from 1,322 poultry product samples purchased over a 1-year period from retail stores across Seattle, WA were subtyped by pulsed-field gel electrophoresis (PFGE) using restriction enzyme XbaI. The objectives of the study were (i) to analyze the longitudinal distribution of Salmonella PFGE profiles throughout the sampling period and their clonality within and between poultry processing establishments, (ii) to determine the association between PFGE profiles of Salmonella isolates from locally distributed poultry products and those of clinical isolates submitted to the Washington State Department of Health (WA-DOH) laboratories, and (iii) to compare the PFGE profiles of Salmonella isolates from the National Antimicrobial Resistance Monitoring System (NARMS) retail meats program. During the 1-year sampling period, multiple indistinguishable PFGE patterns were found across multiple poultry processing establishments. Twelve of the 30 unique PFGE profiles of Salmonella isolates from locally purchased poultry products were indistinguishable from the PFGE profiles of clinical Salmonella isolates submitted to the WA-DOH. When the PFGE profiles from the poultry samples were compared with those found in the NARMS database, eight indistinguishable PFGE matches were found with isolates recovered from chicken breasts, ground turkey, and ground beef from multiple states. Although this study revealed some association between PFGE profiles from raw poultry products and those of clinical isolates from the same geographical area, these results do not prove that all of those clinical isolates were from infections acquired through consumption or handling of poultry.

HIGHLIGHTS

[Effectiveness of the thermal ablation in the treatment of human papillomavirus infection and cervical intraepithelial neoplasia in Chinese women]

Objective: To evaluate the effectiveness of thermal ablation in the treatment of human papillomavirus (HPV) infection and cervical intraepithelial neoplasia (CIN) in Chinese women. Methods: The high-risk HPV-positive women aged 20-65 who were detected through a cervical cancer screening project implemented in three rural sites (Etuoke counties in Inner Mongolia, Xiangyuan and Yangcheng counties in Shanxi Province) and one urban site (Shenzhen) in China were included in this prospective study. Follow up evaluation was performed on HPV positive women who underwent thermal ablation (n=166) as well as received no treatment (n=2 716) in cervical cancer screening program. For women with thermal ablation treatment, HPV test and cytology were used for follow-up with the interval of 6 months or longer after treatment. For women without treatment, HPV test was used for annual follow-up. Women with positive results in either of the HPV tests or abnormal cytology were referred for a colposcopy or biopsy if necessary. The HPV clearance rate and the cure rate of CIN were compared between the two groups. Results: A total of 152 women treated with thermal ablation and 2 539 women without treatment reported for follow-up evaluation with the age M(Q1, Q3) of 42 (36, 48) and 47 (41, 54) years old, and the median time to follow-up time of 23.4 (12.4, 24.5) and 23.5 (12.4, 24.0)months, respectively. The HPV clearance rate in women undergoing thermal ablation was significantly higher than that in women with no treatment (73.0% vs 46.1%, P<0.001). The HPV16, HPV52 and HPV58 clearance rates among women receiving thermal ablation were higher than that in women without treatment with the OR (95%CI) of 2.8 (1.3-6.1), 3.2 (1.3-7.9) and 5.8 (2.1-15.6). For women with histologically confirmed CIN at baseline, cure rates were 77.4%(n=72) for thermal ablation. Cure rates of the thermal ablation were 81.0%(n=47) for CIN grade one (CIN1) and 71.4% (n=25) for CIN grade two or worse (CIN2+). Conclusions: Thermal ablation is effective to clear the HPV infection as well as to treat CIN. Particularly for the HPV genotypes with the paramount attributable proportion to cervical cancer and precancerous in China, the HPV clearance rate was significantly higher than that reported in the women without treatment.

The acoustical properties of tetraethyl orthosilicate based granular silica aerogels

Available data suggests that granulated aerogels can be of interest in terms of their sound absorption performance in the audio frequency range. However, there is still no thorough understanding of the complex physical phenomena which are responsible for their observed acoustical properties. This work is an attempt to address this gap through advanced material characterization methods and mathematical modelling. Aerogel samples are produced through a two-step, acid-base sol-gel process, with sol silica concentration and density being the main variables. Their pore structure is carefully characterized by nitrogen sorption analysis and scanning electron microscopy. The acoustical properties of hard-backed granular silica aerogels are measured in an impedance tube and the results predicted accurately with the adopted theoretical model. Although silica aerogels have over 90% of open interconnected pores, this was neither reflected in the measured acoustical properties nor the parameter values predicted with the model. Novel results show that only a proportion of the micro and mesopores in the direct vicinity of the grain surface influenced the acoustical properties of aerogels. Further work in the hierarchical pore structure of aerogels is required to better understand the roles of different pore scales on the measured acoustical properties of a granulated aerogel.

[Performance of a recombinase - aided amplification assay for detection of Schistosoma japonicum infections in Oncomelania hupensis]

OBJECTIVE

To evaluate the efficiency of a recombinase-aided amplification (RAA) assay for the detection of Schistosoma japonicum infections in Oncomelania hupensis snails.

METHODS

A group test was employed. Fifty Oncomelania snails were collected as a detection sample. The detection samples without infected snails were designated as negative specimens, while the detection samples that contained different numbers of infected snails were designated as positive specimens. A total of 10 negative specimens, 10 positive specimens containing 1 infected snail, 20 positive specimens containing 2 infected snails and 10 positive specimens containing 3 infected snails were assigned. Following random grouping, 40 specimens were subject to the florescent RAA assay using a blind method. The miradium shedding method served as a gold standard, and the sensitivity, specificity, Youden's index and coincidence rate of the florescent RAA assay were estimated. In addition, 20 samples consisted of 5 negative specimens and 15 positive specimens with 1, 2 and 3 infected snails respectively were grouped randomly. The same specimens were detected using the crushing method and fluorescent RAA assay with the blind method in a paired-design manner. Then, the test results were compared and analyzed.

RESULTS

Florescent RAA assay detected 29 positives in the 30 specimens containing different numbers of infected snails, with a sensitivity of 96.67%, and 8 negatives in the 10 detection specimens without infected snails, with a specificity of 80.00%, showing a Youden's index of 0.77. The coincidence rate was 100% among 10 repeated assays for a detection specimen. In addition, there was no significant difference in the detection of infected snails between the florescent RAA assay and the crushing method (χ² = 0, P > 0.05), and the actual coincidence rates of the florescent RAA assay and crushing method were 95.00% (19/20) and 90.00% (18/20) with the real results, respectively.

CONCLUSION

Fluorescent RAA assay has a favorable efficiency for the detection of S. japonicum infections in Oncomelania snails, which shows a potential in screening of S. japonicum-infected Oncomelania snails.

[Association of status of mismatch repair protein expression and EB virus infection with clinicopathological parameters in 886 gastric adenocarcinoma patients]

Objective: To analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.

Association of waist circumstance with long-term all-cause mortality and cardiac death in patients with a pacemaker

Funding Acknowledgements

Type of funding sources: None.

Objective

To explore the association of abdominal obesity with long-term prognosis in patients with a pacemaker.

Methods

Patients in the Summit study were enrolled and divided into groups according to baseline waist circumference: with obesity, normal, and lean. Regular follow-up was performed. The primary endpoint was all-cause mortality, and the secondary endpoint was cardiac death.

Results

In total, 492 patients were included in the analysis. The average baseline waist circumference was 84.2 ± 12.7 cm, and abdominal obesity was observed in 37.6% of patients. During a mean follow-up of 67.2 ± 17.5 months,71 all-cause mortality (14.40%) and 24 cardiac death (4.87%) events occurred. All-cause mortality was associated with higher waist circumference (87.6 versus 83.6 cm, P = 0.014), but not body mass index (23.6 versus 23.5, P= 0.930). Multivariate Cox analysis showed compared with patients with abdominal obesity, lean patients had a significant survival benefit in both all-cause mortality (HR 0.188, 95%CI 0.070-0.505, P = 0.001) and cardiac death (HR 0.097, 95% CI 0.012-0.792, P = 0.029).

Conclusions

Waist circumference was associated with long-term all-cause mortality and cardiac death. Baseline waist circumference less than 80 cm for men and less than 75 cm for women had a significant survival benefit.

Structure-dependent antimicrobial mechanism of quaternary ammonium resins and a novel synthesis of highly efficient antimicrobial resin

The demand for powerful and multifunctional water-treatment materials and reagents is increasing, because we are facing worse raw water quality, various tolerant bacteria, and risky disinfection by-products (DBPs) in drinking water. Quaternary ammonium resins (QARs) are promising candidates for water disinfection and purification, but their limited bactericidal capacities are difficult to improve because of the lack of guidelines for enhancing antibacterial efficiency. Therefore, we first systematically studied the structure-dependent antimicrobial mechanism of QARs and found that the best resin skeleton is acrylic-type, the optimal bactericidal alkyl is hexyl or octyl, the most applicable sizes are 80-100 meshes, the best counter anion is iodide ion, and the optimum quaternization reagent is iodoalkane. Moreover, the antibacterial capacity was demonstrated to depend on surficial N⁺ groups, correlating with surficial N⁺ charge density (R² of 0.98) but not with exchange capacity (R² of 0.26), physical adsorption of resin skeleton, or electrostatic adsorption of N⁺ groups. Based on these principles, we synthesized a new resin, Ac-81, with a surficial antibacterial design, which simultaneously exhibited better antimicrobial efficiency (two orders of magnitude) as well as higher contaminant removal potential (61.92%) compared to the traditional Ac-8C antibacterial resin. Furthermore, the new resin showed remarkable broad-spectrum antibacterial effects against Gram-negative E. coli and P. aeruginosa and Gram-positive B. subtilis and S. aureus in simulated water and actual water. Simultaneously, water quality was significantly improved, with HCO₃^-, SO₄^2-, TN, TP, and TOC reduced by 79-90%, >99%, 66-85%, >99%, and 22-26%, respectively. Ac-81 is characterized by facile reusability, high treatment capacity of 1500 bed volume, and good adaptability for treating actual water, providing a promising alternative for drinking-water disinfection and purification.