Effect of taurine on the proliferation, apoptosis and MST1/Hippo signaling in prostate cancer cells

Background

To investigate the effects of taurine on prostate cancer cell proliferation and apoptosis, and on the mammalian sterilization of a 20-like kinase-1 (MST1)/Hippo signaling pathway.

Methods

The prostate cancer DU145 cell line was selected and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to determine the rate of inhibition by taurine on the proliferation of the cells at 1, 10⁻¹, 10⁻², 10⁻³, 10⁻⁴, 10⁻⁵ and 10⁻⁶ mg/mL to obtain the taurine intervention concentrations. The cultured cells were divided into three groups: the blank group was cultured with conventional culture medium, the positive control group was cultured with 2 mg/mL cisplatin, and the taurine group was cultured with the determined taurine intervention concentrations of 0.003 mg/mL as low, 0.03 mg/mL as medium and 0.3 mg/mL as high concentration. After 72 h incubation, cell proliferation, apoptosis and cellular MST1/Hippo signaling pathway protein expression were observed.

Results

In the comparison of cell proliferation rate, the taurine group was lower than the positive control group and the blank group (P<0.05), the cell proliferation rate of different concentrations in the taurine group decreased with the increase of concentration (P<0.05). The apoptosis rate was higher in the taurine group than in the positive control group and the blank group (P<0.05), the apoptosis rate increased with increasing concentration in the taurine group (P<0.05). The expression of MST1 and Bax was higher in the taurine group than in the positive control group and the blank group (P<0.05), the expression of MST1 and Bax increased with increasing concentration in the taurine group (P<0.05). The expression of YAP and Bcl-2 was lower in the taurine group than in the positive control group and the blank group (P<0.05), the expression of YAP and Bcl-2 decreased with increasing concentration in the taurine group (P<0.05).

Conclusions

Taurine promoted apoptosis and inhibited proliferation of prostate cancer cells, and its mechanism of action may be related to the MST1/Hippo signaling pathway in a dose-dependent manner.

High spectral resolution compact Offner spectrometer based on the aberration-reduced convex holographic gratings recorded by spherical waves under Rowland circle mounting

High spectral resolution, excellent imaging quality, and compact configuration have become a recent trend in push-broom imaging spectrometers. The concentric Offner imaging spectrometer has become popular due to its high optical performance and compactness. However, astigmatism is the dominant residual aberration in the Offner imaging spectrometer, which makes the meridional and sagittal images unable to be focused well and causes a deterioration in image quality and spectral resolution. In this paper, we present a compact Offner imaging spectrometer with a high resolution based on an aberration-reduced convex holographic grating (ACHG), which is recorded by spherical waves under Rowland circle mounting. The holographic aberration coefficients of ACHG and geometric aberration coefficients of the Offner imaging spectrometer are derived based on the analysis of the light-path function. Furthermore, we analyzed the relationship between holographic aberration coefficients and holographic recording parameters of ACHG under Rowland circle mounting. To balance the geometric aberration of the Offner imaging spectrometer, proper holographic aberration coefficients of the ACHG are achieved through adjusting the holographic recording parameters. The design result indicated that the Offner imaging spectrometer with ACHG provides better images than those with mechanically ruled convex grating (MRCG). Moreover, the spectral resolution is significantly improved. This lays down a theoretical basis for subsequent construction work in the Offner imaging spectrometer with holographic aberration-reduced gratings.

First-in-Human Computational Preprocedural Planning of Left Main Interventions Using a New Everolimus-Eluting Stent

Left main coronary artery stenting requires rigorous planning and optimal execution. This case series presents a new approach to left main stenting guided by preprocedural patient-specific computational simulations. Three patients with significant left main artery disease underwent simulation-guided intervention using a novel stent scaffold purpose-built for large coronary arteries. (Level of Difficulty: Advanced.).

[ Ⅲ ]

Objective: To investigate the clinical efficacy of long-segment pedicle screw reduction and internal fixation combined with kyphoplasty in the treatment of stage Ⅲ reducible Kummell disease. Methods: The clinical data of 32 patients with stage Ⅲ reducible Kummell disease treated at the Department of Orthopedics, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine from January 2012 to March 2017 were analyzed retrospectively.There were 7 males and 25 females,aged (71.8±6.7)years(range:61 to 86 years).The injured segment was T₁₀ in 1 patient,T₁₁ in 8 patients,T₁₂ in 13 patients,L₁ in 7 patients,L₂ in 2 patients and L₃ in 1 patient.Preoperative American spinal injury association(ASIA) classification of patients all showed grade D.Bone mineral density (BMD),spinal X-ray,CT and MRI were examined before operation.All patients were treated with postural reduction, long-segment pedicle screw reduction and internal fixation combined with kyphoplasty.The operation time,intraoperative blood loss,length of stay and postoperative complications were recorded.The visual analogue scale (VAS) and Oswestry dysfunction index (ODI) as well as the BMD of hip were collected before and after operation.The Cobb angle of involved segment kyphosis and the height of anterior edge of diseased vertebrae were measured before operation,3 days and 12 months after operation.CT-related parameters were measured before and 3 days after operation,including sagittal anterior and posterior diameter of spinal canal,cross-sectional anterior and posterior diameter of spinal canal and cross-sectional spinal canal area.Paired sample t test and repeated measures were used to compare the data before and after operation. Results: All patients received the operation successfully.The operation time was (131.3±16.9) minutes (range:95 to 180 minutes),the blood loss was (82.5±27.1) ml (range:50 to 150 ml),and the length of stay was (8.3±2.4) days (range:5 to 14 days).All patients were followed up for more than 12 months.The VAS decreased gradually at 3 days,3 months,6 months and 12 months after operation,and the differences were statistically significant compared with the VAS before surgery (all P<0.01).ODI at 3,6 and 12 months after surgery was significantly improved compared with that before surgery(All P<0.01).The CT-related parameters at 3 days after operation were significantly higher than those before operation (All P<0.05).At 12 months after surgery,the Cobb angle decreased from (35.2±7.6) ° preoperatively to (4.3±1.7) ° (t=22.630,P<0.01),the height of anterior edge of diseased vertebrae increased from (4.3±1.0) mm preoperatively to (16.9±2.5) mm(t=-25.845,P<0.01),the bone mineral density of hip increased from -(2.2±0.6) preoperatively to -(2.8±0.6)(t=-0.040,P<0.01).Up to the last follow-up,2 patients had distal pedicle screw loosening, 1 patient had proximal junctional kyphosis,and there was no new vertebral fracture. Conclusions: Based on postural reduction,long-segment pedicle screw reduction and internal fixation combined with kyphoplasty is a safe and effective treatment method for stage Ⅲ reducible Kummell disease,which can reconstruct the stability of the diseased vertebrae.Postoperative standard anti-osteoporosis treatment is the basis to ensure the efficacy.

Significance of soil moisture on temperature dependence of Hg emission

Soil moisture is a key factor for mercury (Hg) emission from soil. Despite its significance for Hg emissions, the effect of soil moisture on Hg flux and fractions has not been thoroughly investigated. The objective of this study was to elucidate the influences of soil moisture and temperature on Hg fluxes from soils and Hg fractions. A kinetic study was performed to measure Hg emission fluxes of six soil samples under different temperature (T) (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) and moisture conditions (0%, 10%, and 20% added water). The results showed that the Hg fluxes increased with increases in T and soil moisture. A linear correlation was found between ln (Hg emission flux) and 1/T for the six soil samples at different moisture contents (R² = 0.73-0.99). The range of activation energy (Ea) values was 25.31-57.86 kJ/mol. The Hg fractions in soils of different moisture content were determined by a sequential extraction method. The results demonstrated that soil moisture affected the Hg fractions in soils. The Ea values had different relationships with soil moisture in different soils. There were correlations between Ea and the elemental and mercuric sulfide fractions for air-dried soils. However, for moist soils, Ea was negatively correlated with the water-soluble and acid-soluble fractions. Collectively, the combination of the Hg emission kinetics and Hg fraction measurement of different moist soils indicated that Hg emission was affected by both total Hg concentration and Hg fractions.

[Performance of point-of-care testing for cervical cancer screening]

Objective: To evaluate the performance of point-of-care testing for cervical cancer and precancerous lesions screening. Methods: In September 2020, 197 and 273 women were selected by using simple random sampling method from "self-sampling" cohort and "physician-sampling" cohort established in Xiangyuan county, Shanxi Province, China, respectively. Cervical exfoliated cells were collected by women themselves or gynecologists. All samples were detected by POCT and women with positive result were directly referred for colposcopy. Subsequently, all the samples were detected by careHPV and PCR test. Colposcopy and punch biopsy were performed for women with POCT negative but careHPV or PCR test positive at another visit. Using histopathological diagnosis as the gold standard, we calculated sensitivity, specificity and drew the receiver operating characteristic (ROC) curves. The accuracy of POCT was analyzed and compared to that of careHPV and conventional PCR test in cervical cancer and precancerous lesions screening. Results: The median (Q₁ , Q₃) age of 470 women was 51 (45, 57) years old. Based on self-sampling, the sensitivity and specificity of POCT for CIN2+ were 100.00% (95%CI: 56.56%-100.00%) and 28.95% (95%CI: 22.97%-35.76%), respectively. Compared with POCT, POCT HPV16/18 test had similar sensitivity and higher specificity of 89.47% (95%CI: 84.30%-93.08%). Self-sampling POCT HPV16/18 test had an AUC of 0.947 (95%CI:0.910-0.985), which was higher than that of careHPV and PCR test. Physician-sampling POCT test had 100.00% sensitivity (95%CI: 64.57%-100.00%) and 55.85% specificity (95%CI: 49.83%-61.70%) for detecting CIN2+. POCT HPV16/18 test had lower sensitivity (71.43%, 95%CI: 35.90%-91.76%) and higher specificity (92.45%, 95%CI: 88.63%-95.06%). POCT HPV16/18 test generally showed similar AUC on both self-collected samples and clinician-collected samples (0.947 vs 0.819, P=0.217). Conclusion: POCT HPV16/18 test is an effective method with relatively high sensitivity and specificity for cervical cancer screening.

[Identification of traditional Chinese drugs containing active ingredients for treating myocardial infarction and analysis of their therapeutic mechanisms by network pharmacology and molecular docking]

OBJECTIVE

To identify traditional Chinese drugs that contain active ingredients for treatment of myocardial infarction (MI) and explore their therapeutic mechanisms using network pharmacology and molecular docking technology.

METHODS

The TCMSP database was used for screening the traditional Chinese drugs containing active ingredients for treating MI, and the related targets of MI and the candidate drugs were obtained from Genecards, OMIM, PharmGkb and PharmMapper databases. The common target network of the drug targets and disease targets was established using Venny2.1.0 software. GO and KEGG signal pathway enrichment analysis of the common targets was performed, and the protein-protein interaction (PPI) network was constructed for the targets. The targets in the PPI network were analyzed to identify the key targets, for which GO and KEGG pathway enrichment analyses were performed. Molecular docking was performed for the candidate ingredients and the key targets, and a total score ≥6 was used as the criteria for screening the therapeutic ingredients and their docking binding with key targets was verified. A human umbilical vein endothelial cell (HUVEC) model of oxygen-glucose deprivation (OGD) was used to validate the candidate ingredients and the key therapeutic targets for MI by Western blotting.

RESULTS

Our analysis identified Salvia miltiorrhiza and Dalbergiae odoriferae as the candidate drugs rich in active ingredients for treatment of MI. These ingredients involved 16 key therapeutic targets for MI, which participated in such biological processes as inflammatory response, angiogenesis, energy metabolism and oxidative stress and the pathways including HIF-1, VEGF, and TNF pathways. Sclareol and PTGS2 in Salvia miltiorrhiza and formononetin and KDR in Dalbergiae odoriferae all had high docking total scores. Western blotting showed that at medium and high doses, sclareol significantly inhibited PTGS2 expression and formononetin promoted KDR expressions in the cell models in a dose-dependent manner (P < 0.05).

CONCLUSION

Both Salvia miltiorrhiza and Dalbergiae odoriferae have good therapeutic effects on MI. Sclareol in Salvia miltiorrhiza and formononetin in Dalbergiae odoriferae regulate the expressions of KDR and PTGS2, respectively, to modulate the inflammatory response, angiogenesis, oxidative stress and energy metabolism and thus produce myocardial protective effects.

Establishment of prediction models for COVID-19 patients in different age groups based on Random Forest algorithm

BACKGROUND

Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic. Age is an independent factor in death from the disease, and predictive models to stratify patients according to their mortality risk are needed.

AIM

To compare the laboratory parameters of the younger (≤70) and the elderly (>70) groups, and develop death prediction models for the two groups according to age stratification.

DESIGN

A retrospective, single-center observational study.

METHODS

This study included 437 hospitalized patients with laboratory-confirmed COVID-19 from Tongji Hospital in Wuhan, China, 2020. Epidemiological information, laboratory data and outcomes were extracted from electronic medical records and compared between elderly patients and younger patients. First, recursive feature elimination (RFE) was used to select the optimal subset. Then, two random forest (RF) algorithms models were built to predict the prognoses of COVID-19 patients and identify the optimal diagnostic predictors for patients' clinical prognoses.

RESULTS

Comparisons of the laboratory data of the two age groups revealed many different laboratory indicators. RFE was used to select the optimal subset for analysis, from which 11 variables were screened out for the two groups. The RF algorithm were built to predict the prognoses of COVID-19 patients based on the best subset, and the area under ROC curve (AUC) of the two groups is 0.874 (95% CI: 0.833-0.915) and 0.842 (95% CI: 0.765-0.920).

CONCLUSION

Two prediction models for COVID-19 were developed in the patients with COVID-19 based on random forest algorithm, which provides a simple tool for the early prediction of COVID-19 mortality.

Characterization of genetic fundamentals for piglet mortality at birth in Yorkshire, Landrace, and Duroc sows

Piglet mortality is an economically important complex trait that impacts sow prolificacy. Genetic analyses for piglet mortality at weaning have been reported in dozens of studies, but not for piglet mortality at birth. In this study, we used multi-breed data sets from Yorkshire, Landrace, and Duroc sows to characterize the genetic fundamentals of piglet mortality at birth. The heritabilities from parity I to III were estimated to be 0.0630, 0.1031, and 0.1140 respectively. By using a combined strategy, a total of 21 SNPs were detected in three parities, of which six were observed in parity I, five in parity II and 10 in parity III. Genome annotation revealed that these SNPs were harbored within or close to 19 candidate genes. The candidate genes were found to associate with the reproductive system and embryonic development in the tissue expression database, which are reasonably related to piglet mortality. These findings are expected to provide much information for understanding the genetic and genomic fundamentals of farrowing mortality.

Molecular characterisation and function analysis of NOD1 gene from Yangzhou goose (Anser cygnoides domesticus)

1. NOD1 is a significant member of the NOD-like receptor (NLR) family. Its main role is to identify microorganisms that invade the body, transmit immune signals and regulate innate immune responses. However, the expression and role of the NOD1 in immune defence against infection in geese remain unknown.2. The RT-PCR method and rapid amplification of cDNA ends (RACE) was used to obtain the full-length goose NOD1 (gNOD1) cDNA series. The cDNA for gNOD1 contains 2856-bp nucleotides, i.e. 47-bp 5' UTR, 135-bp 3' UTR, and 1275-bp ORF region, and encodes a 951-amino-acids (AAs) polypeptide chain. The nucleotide sequence of gNOD1 was found more than 90% similar to its homologs from other avian organisms.3. The qRT-PCR results showed that gNOD1 mRNA was widely distributed in different tissues, but highly expressed in liver, spleen, lung and caecum tissues.4. Following stimulation of goose embryo fibroblasts (GEFs) with lipopolysaccharide (LPS) and polyriboinosinic polyribocytidylic acid (poly(I:C)), the expression of gNOD1 and cytokines, such as IL-1β, IL-6, IL-18, and TNF-α, changed with the response-efficacy correlation at 24 and 48 h post-infection (hpi).5. When the goslings were challenged with Salmonella entertidis (SE) and LPS, the expression of gNOD1 was up-regulated at 3 and 6 hpi in the spleen and caecum tissues, respectively. However, after SE infection, the expression level of gNOD1 fluctuated, while in the LPS group, gNOD1 mRNA increased immediately at a peak time of 6 hpi and then steadily declined. These results indicated that NOD1 was associated with the potency to resist bacterial and viral infections in the goose, both in vivo and in vitro.

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.

[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.