Improved small vessel visibility in diabetic foot arteriography using dual-energy CT

AIM

To test the feasibility and performance of dual-energy computed tomography (DECT) in foot arteriography of diabetic patients, where contrast medium is largely reduced within the small vessels.

MATERIALS AND METHODS

A total of 50 diabetic patients were enrolled prospectively, where DECT was acquired immediately after the CT angiography (CTA, group A) of the lower extremity. Two images were derived from the DECT data, one optimal virtual monochromatic image (VMI, group B) and one fusion image (group C), both of which were compared against the CTA image for visualising the foot arteries. The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were evaluated. The arterial course and contrast were graded each using a five-point scale. The clarity of small vessel depiction was quantified by comparing the number of plantar metatarsal arteries found in the maximum intensity projection image.

RESULTS

The median CNRs and SNRs obtained in group B were approximately 45% and 20% higher than those in groups A and C, respectively (p<0.05). Group B also received higher subjective scores on the posterior tibial artery and the foot arteries (all >3) than groups A and C. The number of visible branches of the plantar metatarsal arteries was found to be substantially higher (p<0.05) in group B (median=6) than in groups A (median=2) and C (median=4).

CONCLUSION

DECT was found to be superior to conventional CTA in foot arteriography, and beyond the lower extremity, it might be a general favourable solution for imaging regions with small vessels and reduced contrast medium.

[Promote the high-quality development of gastrointestinal surgery with technological concept innovation]

In the past 30 years, gastrointestinal surgery in China has made significant progress, which is reflected in the gradual standardization of clinical diagnosis and treatment, significant improvement in surgical quality, improvement in short-term and long-term postoperative outcomes, and continuous development of high-quality clinical research. At present, the spectrum of disease in gastrointestinal surgery has changed from traditional benign diseases to malignant diseases represented by gastric cancer and colorectal cancer, metabolic diseases represented by obesity and diabetes, and immune diseases represented by inflammatory bowel disease. It is necessary to carry out full-cycle management for patients. In the new era full of opportunities and challenges, surgeons must be driven by innovation in surgical technology, guided by high-quality clinical research and guaranteed by standardized diagnosis and treatment of diseases, to continue to promote the high-quality development of gastrointestinal surgery in China.

Dosimetric Quality of Artificial Intelligence Based Organ at Risk Segmentation

PURPOSE/OBJECTIVE(S)

to compare dosimetric parameters between Artificial intelligence (AI) generated organ at risks (OAR) and Radiation Oncologist approved OARs and evaluation of appropriateness unedited AI- OARs in routine clinical plan optimization and evaluation.

MATERIALS/METHODS

The OARs (lung, spinal cord and heart) for twenty SBRT (stereotactic body radiotherapy) lung CT simulation datasets were derived by AI based segmentation algorithms. These AI- OARs were edited by a staff Radiation Oncologist and then subjected to our SBRT peer-review process at our institution. A SBRT plan based on the approved contours was created. Dosimetric parameters for the unedited AI-OARs and edited physician-approved OARs were then compared.

RESULTS

Lung V20 differences between AI- OAR and physician- OAR varied from 0.01% - 0.7% with a mean value of 0.1% difference (p-value 0.004). Spinal cord D0.03cc varied from 0.02 Gy - 0.9 Gy with a mean value of 0.3 Gy difference (p-value 0.002). Heart D0.03cc varied from 0.01 Gy - 4.3 Gy with mean value 0.9 Gy difference (p-value 0.02).

CONCLUSION

Dosimetric parameters for AI-based lung, spinal cord and heart OARs vs physician approved OARs were different, overall, the differences were generally small. These differences are likely on par with inter-observer differences seen between individual radiation oncologists. Unedited OARs have the promise for routine use in plan optimization and evaluation to further improve efficiency.

CXCR2 expression during melanoma tumorigenesis controls transcriptional programs that facilitate tumor growth

BACKGROUND

Though the CXCR2 chemokine receptor is known to play a key role in cancer growth and response to therapy, a direct link between expression of CXCR2 in tumor progenitor cells during induction of tumorigenesis has not been established.

METHODS

To characterize the role of CXCR2 during melanoma tumorigenesis, we generated tamoxifen-inducible tyrosinase-promoter driven BrafV600E/Pten-/-/Cxcr2-/- and NRasQ61R/INK4a-/-/Cxcr2-/- melanoma models. In addition, the effects of a CXCR1/CXCR2 antagonist, SX-682, on melanoma tumorigenesis were evaluated in BrafV600E/Pten-/- and NRasQ61R/INK4a-/- mice and in melanoma cell lines. Potential mechanisms by which Cxcr2 affects melanoma tumorigenesis in these murine models were explored using RNAseq, mMCP-counter, ChIPseq, and qRT-PCR; flow cytometry, and reverse phosphoprotein analysis (RPPA).

RESULTS

Genetic loss of Cxcr2 or pharmacological inhibition of CXCR1/CXCR2 during melanoma tumor induction resulted in key changes in gene expression that reduced tumor incidence/growth and increased anti-tumor immunity. Interestingly, after Cxcr2 ablation, Tfcp2l1, a key tumor suppressive transcription factor, was the only gene significantly induced with a log2 fold-change greater than 2 in these three different melanoma models.

CONCLUSIONS

Here, we provide novel mechanistic insight revealing how loss of Cxcr2 expression/activity in melanoma tumor progenitor cells results in reduced tumor burden and creation of an anti-tumor immune microenvironment. This mechanism entails an increase in expression of the tumor suppressive transcription factor, Tfcp2l1, along with alteration in the expression of genes involved in growth regulation, tumor suppression, stemness, differentiation, and immune modulation. These gene expression changes are coincident with reduction in the activation of key growth regulatory pathways, including AKT and mTOR.

Towards texture accurate slice interpolation of medical images using PixelMiner

Quantitative image analysis models are used for medical imaging tasks such as registration, classification, object detection, and segmentation. For these models to be capable of making accurate predictions, they need valid and precise information. We propose PixelMiner, a convolution-based deep-learning model for interpolating computed tomography (CT) imaging slices. PixelMiner was designed to produce texture-accurate slice interpolations by trading off pixel accuracy for texture accuracy. PixelMiner was trained on a dataset of 7829 CT scans and validated using an external dataset. We demonstrated the model's effectiveness by using the structural similarity index (SSIM), peak signal to noise ratio (PSNR), and the root mean squared error (RMSE) of extracted texture features. Additionally, we developed and used a new metric, the mean squared mapped feature error (MSMFE). The performance of PixelMiner was compared to four other interpolation methods: (tri-)linear, (tri-)cubic, windowed sinc (WS), and nearest neighbor (NN). PixelMiner produced texture with a significantly lowest average texture error compared to all other methods with a normalized root mean squared error (NRMSE) of 0.11 (p < .01), and the significantly highest reproducibility with a concordance correlation coefficient (CCC) ≥ 0.85 (p < .01). PixelMiner was not only shown to better preserve features but was also validated using an ablation study by removing auto-regression from the model and was shown to improve segmentations on interpolated slices.

[Prevalence of colorectal cancer in 2020: a comparative analysis between China and the world]

Objective: To demonstrate the disease burden and epidemiological characteristics of colorectal cancer in different regions by analyzing the incidence and mortality data in China and worldwide in 2020. Methods: Estimation of the incidence and mortality data of colorectal cancer were obtained from the GLOBOCAN 2020 database. The incidence, death, age standardized incidence rate (ASIR) and age standardized mortality rate (ASMR) of colorectal cancer in China and 20 regions in the world were compared. The correlation between the Human Development Index (HDI) and ASIR/ASMR was analyzed. Results: In 2020, the number of new cases of colorectal cancer in the world reached 1 931 600, and the number of deaths reached 935 200. The incidence and mortality in all regions of the world continued to rise in the age group above 50 years old. The morbidity and mortality in male were higher than those in female. East Asia ranked the highest number of incidence cases and deaths in the world, which were 740 000 and 360 100 respectively. There were significant differences in incidence and mortality among regions in the world. The highest ASIR and ASMR were observed in Northern Europe (33.61/100 000) and Eastern Europe (14.53/100 000), whereas the lowest ASIR and ASMR were both observed in South-Central Asia (5.46/100 000 and 3.16/100 000). HDI had significant exponential relationship with ASIR (r(2)=0.59, P<0.001) and ASMR (r(2)=0.38, P<0.001). There were 555 500 new cases and 286 200 death cases of colorectal cancer in China, accounting for about 30% of the world and more than 75% of East Asia. The ASIR of China was 24.07/100 000, ranking at the medium level, while the ASMR was 12.07/100 000, ranking at the high level of world. Conclusion: The incidence and mortality of colorectal cancer are highly correlated with HDI. China is one of the countries with the heaviest disease burden of colorectal cancer in the world.

CXCR2 expression during melanoma tumorigenesis controls transcriptional programs that facilitate tumor growth

Background

Though the CXCR2 chemokine receptor is known to play a key role in cancer growth and response to therapy, a direct link between expression of CXCR2 in tumor progenitor cells during induction of tumorigenesis has not been established.

Methods

To characterize the role of CXCR2 during melanoma tumorigenesis, we generated tamoxifen-inducible tyrosinase-promoter driven Braf ^V600E /Pten ^-/- /Cxcr2 ^-/- and NRas ^Q61R /INK4a ^-/- /Cxcr2 ^-/- melanoma models. In addition, the effects of a CXCR1/CXCR2 antagonist, SX-682, on melanoma tumorigenesis were evaluated in Braf ^V600E /Pten ^-/- and NRas ^Q61R /INK4a ^-/- mice and in melanoma cell lines. Potential mechanisms by which Cxcr2 affects melanoma tumorigenesis in these murine models were explored using RNAseq, mMCP-counter, ChIPseq, and qRT-PCR; flow cytometry, and reverse phosphoprotein analysis (RPPA).

Results

Genetic loss of Cxcr2 or pharmacological inhibition of CXCR1/CXCR2 during melanoma tumor induction resulted in key changes in gene expression that reduced tumor incidence/growth and increased anti-tumor immunity. Interestingly, after Cxcr2 ablation, Tfcp2l1 , a key tumor suppressive transcription factor, was the only gene significantly induced with a log ₂ fold-change greater than 2 in these three different melanoma models.

Conclusions

Here, we provide novel mechanistic insight revealing how loss of Cxcr2 expression/activity in melanoma tumor progenitor cells results in reduced tumor burden and creation of an anti-tumor immune microenvironment. This mechanism entails an increase in expression of the tumor suppressive transcription factor, Tfcp2l1, along with alteration in the expression of genes involved in growth regulation, tumor suppression, stemness, differentiation, and immune modulation. These gene expression changes are coincident with reduction in the activation of key growth regulatory pathways, including AKT and mTOR.

Proteomics unite traditional toxicological assessment methods to evaluate the toxicity of iron oxide nanoparticles

Iron oxide nanoparticles (IONPs) are the first generation of nanomaterials approved by the Food and Drug Administration for use as imaging agents and for the treatment of iron deficiency in chronic kidney disease. However, several IONPs-based imaging agents have been withdrawn because of toxic effects and the poor understanding of the underlying mechanisms. This study aimed to evaluate IONPs toxicity and to elucidate the underlying mechanism after intravenous administration in rats. Seven-week-old rats were intravenously administered IONPs at doses of 0, 10, 30, and 90 mg/kg body weight for 14 consecutive days. Toxicity and molecular perturbations were evaluated using traditional toxicological assessment methods and proteomics approaches, respectively. The administration of 90 mg/kg IONPs induced mild toxic effects, including abnormal clinical signs, lower body weight gain, changes in serum biochemical and hematological parameters, and increased organ coefficients in the spleen, liver, heart, and kidneys. Toxicokinetics, tissue distribution, histopathological, and transmission electron microscopy analyses revealed that the spleen was the primary organ for IONPs elimination from the systemic circulation and that the macrophage lysosomes were the main organelles of IONPs accumulation after intravenous administration. We identified 197 upregulated and 75 downregulated proteins in the spleen following IONPs administration by proteomics. Mechanically, the AKT/mTOR/TFEB signaling pathway facilitated autophagy and lysosomal activation in splenic macrophages. This is the first study to elucidate the mechanism of IONPs toxicity by combining proteomics with traditional methods for toxicity assessment.

Observed coupling between air mass history, secondary growth of nucleation mode particles and aerosol pollution levels in Beijing

Atmospheric aerosols have significant effects on the climate and on human health. New particle formation (NPF) is globally an important source of aerosols but its relevance especially towards aerosol mass loadings in highly polluted regions is still controversial. In addition, uncertainties remain regarding the processes leading to severe pollution episodes, concerning e.g. the role of atmospheric transport. In this study, we utilize air mass history analysis in combination with different fields related to the intensity of anthropogenic emissions in order to calculate air mass exposure to anthropogenic emissions (AME) prior to their arrival at Beijing, China. The AME is used as a semi-quantitative metric for describing the effect of air mass history on the potential for aerosol formation. We show that NPF events occur in clean air masses, described by low AME. However, increasing AME seems to be required for substantial growth of nucleation mode (diameter < 30 nm) particles, originating either from NPF or direct emissions, into larger mass-relevant sizes. This finding assists in establishing and understanding the connection between small nucleation mode particles, secondary aerosol formation and the development of pollution episodes. We further use the AME, in combination with basic meteorological variables, for developing a simple and easy-to-apply regression model to predict aerosol volume and mass concentrations. Since the model directly only accounts for changes in meteorological conditions, it can also be used to estimate the influence of emission changes on pollution levels. We apply the developed model to briefly investigate the effects of the COVID-19 lockdown on PM_2.5 concentrations in Beijing. While no clear influence directly attributable to the lockdown measures is found, the results are in line with other studies utilizing more widely applied approaches.

Proteomic profiling of Arachis hypogaea in response to drought stress and overexpression of AhLEA2 improves drought tolerance

Drought is the main factor restricting peanut growth, but the molecular mechanism underlying peanut drought tolerance remains unclear. Herein, the seedling stage of drought-resistant peanut cultivar J11 was subjected to drought stress, and its proteomic profile was systematically analysed by isobaric tags for relative and absolute quantification (iTRAQ), the results of which were further complemented with our previous transcriptome results. A total of 4,018 proteins were identified by proteomic analysis, which revealed that the expression levels of 69 proteins were altered under drought stress. Among the differentially expressed proteins (DEPs), 50 were upregulated, and 19 were downregulated. The most enriched metabolic pathways for these DEPs were those involving phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction. The proteomic data and previous transcriptome results revealed 44 groups of genes/proteins with the same expression trend, including a LEA (Late embryogenesis abundant) gene, AhLEA2. Our present study showed that overexpression of the AhLEA2 gene enhanced the drought resistance of transgenic Arabidopsis plants, and the activities of related antioxidant enzymes in the transgenic plants significantly changed. The AhLEA2 gene was found to be located in the cytoplasm and cell membrane by subcellular localization experiments. This work systematically analysed the differentially expressed proteins in peanut in response to drought stress, providing important candidates for further functional analysis of the stress response of peanut. Our results also indicated that AhLEA2 plays an important role in the peanut response to drought stress.

Immunity cells in the small intestinal mucosa of newborn yaks

BACKGROUND

This study aimed to characterize and evaluate the main markers of T lymphocytes, B lymphocytes, immunoglobulin (Ig) A and IgG plasmocytes, macrophages, and dendritic cells of the intestinal mucosa of newborn yaks.

MATERIALS AND METHODS

Ten newborn yaks (2-4 weeks old) were choosed. Immunohistochemistry and real-time quantitative polymerase chain reaction were used to analyze the immune cell distribution and specific markers at the mRNA expression level in the duodenum, jejunum, and ileum.

RESULTS

The results showed in the epithelium, CD3-positive T lymphocyte levels were higher than other immune cell levels (P<0.05). Additionally, in the lamina propria, the number of cells positive for CD3, CD68, and signal inhibitory regulatory protein alpha (SIRPα) were higher in the villi, while CD79α, IgA, and IgG cells were more common at the base of the crypt. Moreover, both in the epithelium and lamina propria, the number of CD3, CD68 and SIRPα were decreased from the duodenum to the ileum (P<0.05), additionally the number of CD79α, IgA and IgG positive cells were increased from the duodenum to the ileum of newborn yaks (P<0.05). Furthermore, the mRNA expression levels of CD3ε, CD68, and SIRPα increased from the duodenum to the ileum (P<0.05), while the mRNA expression levels of CD79α, IgA, and IgG decreased from the duodenum to the ileum.

CONCLUSIONS

Immunohistochemical characterization and expression levels of immune factors in the small intestinal mucosa of newborn yaks suggest that the intestinal mucosa is an important part of the natural barrier and provides useful references for immunity functions of newborn yak intestinal mucosa.

BGL3 inhibits papillary thyroid carcinoma progression via regulating PTEN stability

PURPOSE

BGL3, a novel long non-coding RNA (lncRNA) that plays a crucial role in several human malignancies. However, the clinical significance and biological function of BGL3 in papillary thyroid carcinoma (PTC) have not been explored. Herein, we aimed to investigate the role of BGL3 in human PTC.

METHODS

A total of 85 pairs of PTC and normal tissues were collected for clinicopathological analysis. Expression of BGL3 was determined by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of BGL3 on PTC cells ware determined by CCK-8, colony formation, EdU and wound healing assays. The molecular mechanism underlying BGL3 was tested by ChIP, Co-IP, RNA pull-down and luciferase reporter assays. In vivo experiments were conducted using xenografts in nude mice.

RESULTS

BGL3 was significantly decreased in PTC tissues compared to adjacent normal thyroid tissues, and it was transcriptionally repressed by oncogene Myc. Low BGL3 is positively related to larger tumor size, lymph node metastasis, later TNM stage and poor prognosis. Overexpression of BGL3 inhibited PTC cell proliferation and migration in vitro, and reduced tumor size and lung metastasis nodules in vivo. BGL3 was mainly located in the cytoplasm, in which interacted with PTEN and recruited OTUD3, enhancing the de-ubiquitination effect of OTUD3 on PTEN, resulting in increasing PTEN protein stability and inactivating carcinogenic PI3K/AKT signaling.

CONCLUSIONS

Our data underscore the critical tumor-inhibiting role of BGL3 in PTC via post-translational regulation of PTEN protein stability, which may serve as a novel therapeutic target and prognostic biomarker in human PTC.

Macrophage M1/M2 ratio as a predictor of pleural thickening in patients with tuberculous pleurisy

We evaluated the association between macrophage polarization and the development of pleural thickening in patients with tuberculous pleurisy. Patients with tuberculous pleurisy admitted to our hospital between October 2018 and March 2019 were prospectively recruited. Pleural fluid samples were obtained before treatment for detection of adenosine deaminase (ADA) and macrophage phenotype (M1: CD14+ CD86+; M2: CD14+ CD163+). Peripheral blood samples were subjected to interferon gamma release assay (IGRA). All subjects were administered standard anti-tuberculosis regimen (2HREZ/4HR); high-resolution CT was performed to determine pleural thickening (thickness>2mm) after completion of treatment. Pleural effusion in patients with thickened pleura had significantly more M1 but fewer M2 macrophages, and higher ADA level, as compared to those with normal pleura (P<0.05). No significant between-group difference was observed with respect to IGRA. In receiver operating characteristic (ROC) curve analysis, the optimal cut-off level of M1/M2 ratio for predicting pleural thickening was 1.149 (area under the curve: 0.842; sensitivity: 88.6%; specificity: 69.2%; positive predictive value: 86.3%; negative predictive value: 81.7%). M1/M2 ratio in the pleural fluid is a promising marker for predicting the development of pleural thickening in patients with tuberculous pleurisy. Macrophage-mediated immune response may play an important role in the pathogenesis of tuberculous pleurisy.

[rCsHscB derived from Clonorchis sinensis has therapeutic effect on dextran sodium sulfate-induced chronic ulcerative colitis in mice]

OBJECTIVE

To investigate the therapeutic effect of rCsHscB derived from Clonorchis sinensis on dextran sodium sulfate (DSS)-induced chronic ulcerative colitis in mice.

OBJECTIVE

C57BL/6 mice were randomized into negative control (NC) group (n= 10), rCsHscB group (n=10), DSS group (n=15), and DSS+rCsHscB group (n=15), and in the latter two groups, chronic ulcerative colitis was induced in the mice using 2% DSS. In rCsHscB and DSS+ rCsHscB groups, the mice received intraperitoneal injections of 125 μg/mL rCsHscB on the 4th and 7th day following DSS administration, and PBS was injected in the other two groups. The mice were euthanized on the 84th day, and pathological changes of the colon were evaluated by HE and Masson staining. The levels of CD4⁺ and CD8⁺ T cells in the peripheral blood and lamina propria gastric lymphocytes (LPL) were analyzed by flow cytometer; the levels of IL-6, MCP-1 and IL-10 in colon homogenate were determined using ELISA, and the phosphorylation of ERK1/2, JNK and P38 was detected with Western blotting.

OBJECTIVE

Compared with those in NC group, the mice in rCsHscB group exhibited no adverse responses to the treatment. The mice in DSS group had severe pathologies in the colon with significantly increased ratios of CD4⁺ and CD4⁺/CD8⁺ T cells in peripheral blood and LPL, increased levels of IL-6 and MCP-1 but no obvious changes in IL-10 in colon homogenate, and significantly augmented phosphorylation levels of ERK1/2, JNK and P38. Compared with those in DSS group, the mice in DSS+ rCsHscB group showed ameliorated colon pathologies with decreased CD4⁺T/CD8⁺T cell ratio in the peripheral blood and LPL, significantly decreased IL-6 and MCP-1 levels and increased IL-10 in colon homogenate, and lowered phosphorylation levels of ERK1/2, JNK and P38.

OBJECTIVE

rCsHscB can produce therapeutic effect on DSS-induced chronic ulcerative colitis in mice possibly by inhibiting the production of pro-inflammatory factors and regulating the balance of CD4⁺/CD8⁺T cells through the MAPK pathway.

A genome-wide genetic linkage map and reference quality genome sequence for a new race in the wheat pathogen Pyrenophora tritici-repentis

Pyrenophora tritici-repentis is an ascomycete fungus that causes tan spot of wheat. The disease has a worldwide distribution and can cause significant yield and quality losses in wheat production. The fungal pathogen is homothallic in nature, which means it can undergo sexual reproduction by selfing to produce pseudothecia on wheat stubble for seasonal survival. Since homothallism precludes the development of bi-parental fungal populations, no genetic linkage map has been developed for P. tritici-repentis for mapping and map-based cloning of fungal virulence genes. In this work, we created two heterothallic strains by deleting one of the mating type genes in each of two parental isolates 86-124 (race 2) and AR CrossB10 (a new race) and developed a bi-parental fungal population between them. The draft genome sequences of the two parental isolates were aligned to the Pt-1C-BFP reference sequence to mine single nucleotide polymorphisms (SNPs). A total of 225 SNP markers were developed for genotyping the entire population. Additionally, 75 simple sequence repeat, and two gene markers were also developed and used in the genotyping. The resulting linkage map consisted of 13 linkage groups spanning 5,075.83 cM in genetic distance. Because the parental isolate AR CrossB10 is a new race and produces Ptr ToxC, it was sequenced using long-read sequencing platforms and de novo assembled into contigs. The majority of the contigs were further anchored into chromosomes with the aid of the linkage maps. The whole genome comparison of AR CrossB10 to the reference genome of M4 revealed a few chromosomal rearrangements. The genetic linkage map and the new AR CrossB10 genome sequence are valuable tools for gene cloning in P. tritici-repentis.

Impacts of reference selection on the assembly of suspicious coronavirus genome

The pandemic caused by SARS-CoV-2 has had a significant impact on the whole world. In a theory of the origin of SARS-CoV-2, pangolins are considered as a potential intermediate host. To assemble the genome of suspicious coronavirus (CoV) found in pangolins, SARS-CoV-2 was used as a reference in most of the previous studies, implicitly assuming the pangolin CoV and SARS-CoV-2 are the closest neighbors in evolution. However, this assumption may not be true. We investigated how the choice of reference genome affected the resulting CoV genome assembly. We explored various representative CoVs as the reference genome, and found significant differences in the resulting assemblies. The assembly obtained using RaTG13 as a reference showed better statistics in total length, N50, and pairwise distance reconstruction (PDR) scores than the assembly guided by SARS-CoV-2, indicating that RaTG13 may be a better reference. Therefore, RaTG13 should also be considered as a reference for assembling suspicious CoV found in pangolins and other potential intermediate hosts.

New scheme for the preparation and use of artificial cerebrospinal fluid

This study aimed to explore a set of simplified schemes for the preparation and application of artificial cerebrospinal fluid (ACSF) to improve the experiment efficiency and neurosafety of ACSF. We prepared ACSF into parts A and B, according to the cerebrospinal fluid (CSF) data in rabbits. They were mixed in equal volumes to form ACSF, continous foaming with mixture gas (95% O₂ and 5% CO₂). Sampling inspection showed the chemical stability of ACSF in the three months after preparation. However, it needed to be kept continous foaming, as pH is correlated to the solubility of CO₂. We further improved the application scheme by sealing the foamed ACSF in infusion bags filled with mixture gas, which could keep the pH stable for 24 hours. It was helpful in promoting the progress of clinical and experimental research relating to ACSF.

Dissection and physical mapping of wheat chromosome 7B by inducing meiotic recombination with its homoeologues in Aegilops speltoides and Thinopyrum elongatum

We constructed a homoeologous recombination-based bin map of wheat chromosome 7B, providing a unique physical framework for further study of chromosome 7B and its homoeologues in wheat and its relatives. Homoeologous recombination leads to the dissection and diversification of the wheat genome. Advances in genome sequencing and genotyping have dramatically improved the efficacy and throughput of homoeologous recombination-based genome studies and alien introgression in wheat and its relatives. In this study, we aimed to physically dissect and map wheat chromosome 7B by inducing meiotic recombination of chromosome 7B with its homoeologues 7E in Thinopyrum elongatum and 7S in Aegilops speltoides. The special genotypes, which were double monosomic for chromosomes 7B' + 7E' or 7B' + 7S' and homozygous for the ph1b mutant, were produced to enhance 7B - 7E and 7B - 7S recombination. Chromosome-specific DNA markers were developed and used to pre-screen the large recombination populations for 7B - 7E and 7B - 7S recombinants. The DNA marker-mediated preselections were verified by fluorescent genomic in situ hybridization (GISH). In total, 29 7B - 7E and 61 7B - 7S recombinants and multiple chromosome aberrations were recovered and delineated by GISH and the wheat 90 K SNP assay. Integrated GISH and SNP analysis of the recombinants physically mapped the recombination breakpoints and partitioned wheat chromosome 7B into 44 bins with 523 SNPs assigned within. A composite bin map was constructed for chromosome 7B, showing the bin size and physical distribution of SNPs. This provides a unique physical framework for further study of chromosome 7B and its homoeologues. In addition, the 7B - 7E and 7B - 7S recombinants extend the genetic variability of wheat chromosome 7B and represent useful germplasm for wheat breeding. Thereby, this genomics-enabled chromosome engineering approach facilitates wheat genome study and enriches the gene pool of wheat improvement.

Transfemoral-venous transcatheter access to left ventricle through the created communication of inter-ventricular septum with the assistance of arterio-venous circuit

Background

During transcatheter aortic/mitral valve replacement (TA/MVR), current available routes are limited due to unfavorable entry-angle, vessel-anatomy or mini-thoracotomy. Through created communication of inter-ventricular septum (C-IVS), transfemoral venous transcatheter access to left ventricle becomes feasible with the assistance of arterio-venous circuit.

Purpose

The study was conducted to investigate the feasibility and safety of transfemoral-venous transcatheter access to left ventricle through the created C-IVS in a swine model.

Methods

Via femoral artery, transcatheter puncture of mid-IVS was performed with the custom-made nickel-titanium needle (0.038-inch, needle-tip bent 60 degrees automatically associated with increased hardness when temperature was above 30°C) and 6F-sheath in 20 healthy Chinese mini-swine. Then femoral arterio-venous circuit was established through created C-IVS with hydrophilic guidewire in all swine, and femoral veno-venous circuit was further created through C-IVS and atrial septum in 4 swine. After pre-dilation of C-IVS, a 20F-sheath was introduced into left ventricle transvenously over the guidewire. Furthermore, transfemoral-venous TAVR was attempted with this approach in one swine. C-IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

Results

All transcatheter puncture of IVS was performed successfully in left ventricle and the thickness of mid-IVS was 7.67±0.98 mm. During the puncture, ventricular fibrillation occurred in one swine (successfully defibrillation) and only isolated ventricular premature beats/non-sustained ventricular tachycardia were observed in other swine. In all swine, femoral arterio-venous/veno-venous circuit was established via C-IVS, and the 20F-sheath was introduced into left ventricle safely through femoral vein and C-IVS. With the aid of vessel circuit, the 20F-sheath was further advanced into aorta in 16 swine (the entry-angle was 145.3±12.2 degrees) and into left atrium in 4 swine. After the procedure, there was one swine with moderate tricuspid regurgitation and 5 swine with mild residual shunt (2.6±0.7 mm). In addition, epicardial coronary arteries were normal in all swine. Two months later, residual shunt was still detected in 3 swine and the communication was confirmed pathologically. In other swine, there was no defect of IVS and mild replacement-scar was identified along C-IVS. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

Conclusions

With the aid of vessel circuit, transfemoral-venous transcatheter access to left ventricle is feasible and safe via C-IVS, and transfemoral-venous TAVR was achieved successfully using this novel approach with favorable entry-angle.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

Indirect evaluation of device-endothelialization with cardiac-CT after transcatheter closure of atrial septal defect: how long should antiplatelet therapy last postoperatively?

Background

After transcatheter closure of atrial septal defect (ASD), it is still unclear about the in-vivo process of device-endothelialization in humans, which determines the duration of antiplatelet therapy. Based on contrast-uptake within device, cardiac-CT might have the potential to assess device-endothelialization indirectly.

Purpose

The study was conducted to investigate the status of device-endothelialization with cardiac-CT after transcatheter closure of ASD.

Methods

After more than 6 months of transcatheter ASD closure, cardiac-CT was performed in 119 patients (48M/71F; age: 46.7±14.4 years). According to contrast-uptake within device, complete or incomplete device-endothelialization was determined. In the latter, it was further divided into partial-endothelialization (with filling-defect) and no-endothelialization (without filling-defect). Multivariate logistic regression was used to determine the risk factors of incomplete device-endothelialization. In addition, device-endothelialization was analyzed grossly and histopathologically in 7 patients.

Results

During the implantation-period of 2.57±2.59 years, incomplete device-endothelialization was identified in 43.7% of patients (partial-endothelialization in 36 patients and no-endothelialization in 16 patients). Complete device-endothelialization occurred in 14.3% of patients during 0.5–1 year and 73.8% after one year. After 6-month antiplatelet therapy, migraine restarted in 15 patients with incomplete device-endothelialization and 3 patients with complete device-endothelialization. After one-year antiplatelet therapy, migraine was still detected in 4 of 15 patients with incomplete device-endothelialization. There was a significant association between high in-vivo device-thickness and incomplete device-endothelialization (P&lt;0.001) after adjusted for confounding factors. Pathological findings from 7 patients corresponded well with cardiac-CT.

Conclusions

Cardiac-CT had the potential to evaluate the status of device-endothelialization after transcatheter closure of ASD and there was a good clinico-pathological correlation. Incomplete device-endothelialization was common postoperatively in humans and was associated with device-oversizing. Further research is required to determine the appropriate duration of antiplatelet therapy after device implantation.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

Theoretical studies of the g factors and local structures of the Ni3+ centers in Na2 Zn(SO4 )2 ·4H2 O and K2 Zn(SO4 )2 ·6H2 O crystals

The local structures and the g factors g_i (i = x, y, z) for Ni³⁺ centers in Na₂ Zn(SO₄ )₂ ·4H₂ O (DPPH) and K₂ Zn(SO₄ )₂ ·6H₂ O (PHZS) crystals are theoretically studied by using the perturbation formulas of the g factors for a 3d⁷ ion with low spin (S = 1/2) in orthorhombically compressed octahedra. In these formulas, the contributions to g factors from both the spin-orbit coupling interactions of the central ion and ligands are taken into account, and the required crystal-field parameters are estimated from the superposition model and the local geometry of the systems. Based on the calculations, the Ni-O bonds are found to suffer the axial compression δz (or Δz) of about 0.111 Å (or 0.036 Å) along the z-axis for Ni³⁺ centers in DPPH (or PHZS) crystals. Meanwhile, the Ni-O bonds may experience additional planar bond length variation δx (≈0.015 Å) along x- and y-axes for the orthorhombic Ni³⁺ center in DPPH. The theoretical g factors agree well with the experimental data. The obtained local structural parameters for both Ni³⁺ centers are discussed.

An enrichment method for mapping ambiguous reads to the reference genome for NGS analysis

Mapping short reads to a reference genome is an essential step in many next-generation sequencing (NGS) analyses. In plants with large genomes, a large fraction of the reads can align to multiple locations of the genome with equally good alignment scores. How to map these ambiguous reads to the genome is a challenging problem with big impacts on the downstream analysis. Traditionally, the default method is to assign an ambiguous read randomly to one of the many potential locations. In this study, we explore two alternative methods that are based on the hypothesis that the possibility of an ambiguous read being generated by a location is proportional to the total number of reads produced by that location: (1) the enrichment method that assigns an ambiguous read to the location that has produced the most reads among all the potential locations, (2) the probability method that assigns an ambiguous read to a location based on a probability proportional to the number of reads the location produces. We systematically compared the performance of the proposed methods with that of the default random method. Our results showed that the enrichment method produced better results than the default random method and the probability method in the discovery of single nucleotide polymorphisms (SNPs). Not only did it produce more SNP markers, but it also produced SNP markers with better quality, which was demonstrated using multiple mainstay genomic analyses, including genome-wide association studies (GWAS), minor allele distribution, population structure, and genomic prediction.

[Efficacy of thymectomy in patients with non-thymoma myasthenia gravis]

Objective: To compare the efficacy between thymectomy plus prednisone and prednisone alone in patients with non-thymoma myasthenia gravis (MG). Methods: Thirty generalized MG patients without thymoma who underwent thymectomy were collected as the operation group, and thirty-nine patients without thymectomy who were treated with prednisone alone were matched as the control group. The start point was the enrollment time and the endpoint event was the "clinical remission" (including complete stabilization remission, drug remission, and poor performance). The survival curve was used to analyze the difference of endpoint event time between the two groups. Besides, a 12-month follow-up study was conducted to compare relevant clinical indicators between the two groups. Results: There was no significant difference in the occurrence time of endpoint events between the two groups (P=0.614). After 6-month follow-up, no significant differences were found in clinical remission rate, the dosage of pyridostigmine bromide and prednisone, the peak dosage of prednisone, the use of other immunosuppressive medications and the rate of hospitalization for exacerbation of disease between the two groups (all P>0.05). After 12-month follow-up, the dosage of prednisone and pyridostigmine in the operation group was significantly lower than that in the control group (5(0,10)mg/d vs 7.5(5,10)mg/d and 30(0,105)mg/d vs 90(15,180)mg/d; P=0.038, 0.032). Conclusion: In patients with mild to moderate non-thymoma generalized MG, thymectomy does not achieve faster remission, but it does reduce the long-term dosage of prednisone and bromopyrazine.

PRL3 enhances T-cell acute lymphoblastic leukemia growth through suppressing T-cell signaling pathways and apoptosis

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes and is largely driven by the NOTCH/MYC pathway. Yet, additional oncogenic drivers are required for transformation. Here, we identify protein tyrosine phosphatase type 4 A3 (PRL3) as a collaborating oncogenic driver in T-ALL. PRL3 is expressed in a large fraction of primary human T-ALLs and is commonly co-amplified with MYC. PRL3 also synergized with MYC to initiate early-onset ALL in transgenic zebrafish and was required for human T-ALL growth and maintenance. Mass spectrometry phosphoproteomic analysis and mechanistic studies uncovered that PRL3 suppresses downstream T cell phosphorylation signaling pathways, including those modulated by VAV1, and subsequently suppresses apoptosis in leukemia cells. Taken together, our studies have identified new roles for PRL3 as a collaborating oncogenic driver in human T-ALL and suggest that therapeutic targeting of the PRL3 phosphatase will likely be a useful treatment strategy for T-ALL.

Association study of SNCA gene polymorphisms with schizophrenia in a Chinese North Han population

OBJECTIVE

Previous studies suggested that the alpha-synapse protein (SNCA) gene and its coding product α-synuclein (α-Syn) may play a role in the pathogenesis of neurodegenerative diseases. The mutation of SNCA can influence the formation of nerve fibers and the function of dopaminergic neurons, and that may be related to addictive behavior, such as alcohol dependence. SNCA may overlap with the pathogenesis of schizophrenia and Parkinson's disease or alcohol dependence associated with the dopamine pathway. The aim was to determine the association between three SNCA SNPs (rs3822086C/T, rs11931074G/T, and rs356219A/G) and schizophrenia in a Chinese North Han population.

PATIENTS AND METHODS

A total of 878 subjects, with or without schizophrenia, were included in our study. DNA purification, Polymerase Chain Reaction (PCR) amplification, and subsequent restriction fragment length polymorphism (RFLP) analysis were manipulated to determine genotypes.

RESULTS

Between the schizophrenia group and healthy group, neither the genotype nor allele frequencies of rs3822086C/T, rs11931074G/T, or rs356219A/G differed significantly in either the total sample or the subgroups. In the haplotype analysis, the ATT and GTT haplotype frequencies differed significantly between the patients and controls in the total sample (χ2=6.052, p=0.0139; χ2=4.508, p=0.0337). In the female subgroup, the ATT haplotype frequency differed significantly between the patients and controls (χ2=4.219, p=0.04).

CONCLUSIONS

There was no association between SNCA polymorphisms and schizophrenia in the North Han Chinese population, and the ATT haplotype may be a susceptibility factor for schizophrenia.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Rapid and visual detection of 2019 novel coronavirus (SARS-CoV-2) by a reverse transcription loop-mediated isothermal amplification assay

OBJECTIVE

To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR.

METHODS

We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation.

RESULTS

The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63°C was the optimum reaction temperature. The sensitivities were 2 × 10¹ copies and 2 × 10² copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%-100%), specificity 100% (95% CI 93.7%-100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation.

CONCLUSION

These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups.

Partitioning and physical mapping of wheat chromosome 3B and its homoeologue 3E in Thinopyrum elongatum by inducing homoeologous recombination

We performed homoeologous recombination-based partitioning and physical mapping of wheat chromosome 3B and Th. elongatum chromosome 3E, providing a unique physical framework of this homoeologous pair for genome studies. The wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) and Thinopyrum elongatum (2n = 2x = 14, EE) genomes can be differentiated from each other by fluorescent genomic in situ hybridization (FGISH) as well as molecular markers. This has facilitated homoeologous recombination-based partitioning and engineering of their genomes for physical mapping and alien introgression. Here, we constructed a special wheat genotype, which was double monosomic for wheat chromosome 3B and Th. elongatum chromosome 3E and homozygous for the ph1b mutant, to induce 3B-3E homoeologous recombination. Totally, 81 3B-3E recombinants were recovered and detected in the primary, secondary, and tertiary homoeologous recombination cycles by FGISH. Comparing to the primary recombination, the secondary and tertiary recombination shifted toward the proximal regions due to the increase in homology between the pairing partners. The 3B-3E recombinants were genotyped by high-throughput wheat 90-K single nucleotide polymorphism (SNP) arrays and their recombination breakpoints physically mapped based on the FGISH patterns and SNP results. The 3B-3E recombination physically partitioned chromosome 3B into 38 bins, and 429 SNPs were assigned to the distinct bins. Integrative analysis of FGISH and SNP results led to the construction of a composite bin map for chromosome 3B. Additionally, we developed 22 SNP-derived semi-thermal asymmetric reverse PCR markers specific for chromosome 3E and constructed a comparative map of homoeologous chromosomes 3E, 3B, 3A, and 3D. In summary, this work provides a unique physical framework for further studies of the 3B-3E homoeologous pair and diversifies the wheat genome for wheat improvement.

CTXA hip: the effect of partial volume correction on volumetric bone mineral density data for cortical and trabecular bone

This study compares the results of computed tomography X-ray absorptiometry (CTXA) hip volumetric BMD (vBMD) analyses of cortical and trabecular bone with and without partial volume correction. For cortical bone in some circumstances, corrected cortical volumes were negative and corrected vBMD was very high. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

PURPOSE

Previous studies have reported concerns about the reliability of CTXA hip cortical vBMD measurements generated using partial volume (PV) correction (the "default" analysis, with cortical PV correction). To date, no studies have examined the results of the alternative ("new") analysis (with trabecular PV correction). This study presents in vivo and phantom data comparing the corrected and uncorrected data for cortical and trabecular bone respectively.

METHODS

We used the commercial QCTPro CTXA software to analyze CT scans of 129 elderly Chinese men and women and an anthropomorphic European Proximal Femur phantom (EPFP) and accessed data for two alternative scan analyses using the database dump utility. The CTXA software gives the user two methods of performing the PV correction: (1) a default analysis in which only cortical bone results are corrected; (2) a new analysis in which only trabecular bone results are corrected. Both methods are based on a numerical recalculation of vBMD values without any change in volume of interest (VOI) placement.

RESULT

In vivo, the results of the two analyses for integral bone were the same while cortical and trabecular results were different. PV correction of cortical bone led to a decrease of cortical volume for all four VOIs: total hip (TH), femoral neck (FN), trochanter (TR), and intertrochanter (IT) volumes were reduced on average by 7.8 cm³, 0.9 cm³, 2.5 cm³, and 4.3 cm³ respectively. For TR, where cortex was thinnest, average corrected cortical volume was negative (- 0.4± 1.3 cm³). Corrected cortical vBMD values were much larger than uncorrected ones for TH, FN, and IT. Scatter plots of corrected cortical vBMD against cortical bone thickness showed that elevated results correlated with thinner cortices. When trabecular bone was corrected for the PV effect, trabecular volumes of TH, FN, TR, and IT were reduced on average by 7.9 cm³, 0.8 cm³, 2.6 cm³, and 4.4 cm³ respectively, while vBMD measurements were increased correspondingly. The trabecular volume and vBMD measurements of the two datasets both had highly positive correlations. For the EPFP, the PV-corrected FN data deviated from the nominal phantom value, but was closer for the TR and IT VOIs. Both corrected and uncorrected data overestimated trabecular vBMD, with the corrected results showing greater deviation from nominal values.

CONCLUSION

The default and new CTXA analyses for volumetric data generate different results, both for cortical and trabecular bone. For cortical bone, the uncorrected results are subject to partial volume effects but the correction method of the default analysis overcorrects the effect leading to in part unreasonable results for cortical bone volume and BMD. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

Anastomosis for distal gastrectomy in Chinese patients: uncut roux-Y or roux-Y?

Background

An appropriate method of anastomosis is crucial for gastric cancer patients who require gastrojejunal anastomosis. Surgeons have proposed different types of modified gastrojejunostomies in the last two decades. We focused on two types of standard anastomosis, i.e., Uncut Roux-Y and Roux-Y gastrojejunostomies, and compared the differences in immediate postoperative complications between the two types.

Methods

This is a retrospective study on 236 gastric cancer patients who underwent curative distal gastrectomy with gastrojejunal Roux-Y or Uncut Roux-Y anastomosis for six consecutive years. Immediate postoperative complications were compared between the two groups. The authors discussed the causes of the significant complications and their management.

Results

There was no difference in demographics between the two groups (92 Roux-y Versus 144 Uncut Roux-y). The overall complication rate was 20.8% with 1.4% anastomotic leakage in the Uncut Roux-Y group versus 33.7% with 7.6% anastomotic failures in the Roux-Y group (p < 0.05). More abdominal infections occurred in the Roux-Y anastomosis group compared with the Uncut Roux-Y anastomosis group (p < 0.05). Duration of postoperative stay was significantly longer in patients with Roux-y anastomosis group (p < 0.05).

Conclusions

Considering the surgical simplicity and postoperative complications, the Uncut Roux-Y is a better choice for anastomosis in patients with gastric cancer undergoing gastrojejunostomy. A well-designed large cohort in a multi-centre randomized controlled trial is necessary to support these findings and compare other aspects.

Bone mineral density gains with a second 12-month course of romosozumab therapy following placebo or denosumab

Romosozumab is a therapy that stimulates bone formation and reduces bone resorption. In this study of postmenopausal women with low BMD, a second course of romosozumab following a period off treatment or on denosumab increased or maintained BMD, respectively, and was well tolerated, providing insight into treatment sequence options.

INTRODUCTION

In patients with high fracture risk, therapies that stimulate bone formation provide rapid BMD gains; currently available agents, parathyroid hormone receptor agonists, are limited to a 2-year lifetime exposure and generally used for a single treatment course. However, for long-term osteoporosis management, a second treatment course may be appropriate. Romosozumab, a therapy with the dual effect of increasing bone formation and decreasing bone resorption, reduces fracture risk within 12 months. Here, we report efficacy and safety of a second romosozumab course.

METHODS

In this phase 2, dose-finding study, postmenopausal women with low bone mass (T-score ≤ - 2.0 and ≥ - 3.5) received romosozumab or placebo (month 0-24) followed by placebo or denosumab (month 24-36); participants then received a year of romosozumab (month 36-48).

RESULTS

Of 167 participants who entered the month 36-48 period, 35 had been initially randomized to romosozumab 210 mg monthly. In participants who received romosozumab 210 mg monthly followed by placebo, a second romosozumab course (n = 19) increased BMD by amounts similar to their initial treatment (month 0-12) at the lumbar spine (12.4%; 12.0%, respectively) and total hip (6.0%; 5.5%, respectively). Following denosumab, a second romosozumab course (n = 16) increased BMD at the lumbar spine (2.3%) and maintained BMD at the total hip. Safety profiles were similar between first and second romosozumab courses.

CONCLUSIONS

After 12 months off-treatment, a second romosozumab course again led to rapid and large BMD gains. Following denosumab, BMD gains with romosozumab were smaller than with initial treatment. No new safety findings were observed during the second course.

Secondary formation damage of low-pressure layer during commingled production in multilayered tight gas reservoirs

This paper experimentally investigates fluid back-flow behavior and formation damage during commingled production in multilayered tight gas reservoirs. The development of fluid back-flow in commingled tight gas reservoirs was simulated using a newly designed experimental platform. The results indicate that when there is a pressure difference between different layers during commingled production from tight gas reservoir, water produced from the high-pressure layer will invade the low-pressure layer along with gas back-flow and will accumulate in the near-wellbore area. This will lead to an increase in water saturation and a decline in permeability in the low-pressure layer and result in a significant reduction in ultimate recovery. The outcomes of these experiments demonstrate that as well as the formation damage caused by the working fluid during drilling and fracturing, "Secondary Formation Damage" also occurs during commingled production in multilayered tight gas reservoirs. This secondary formation damage mainly occurs in the near-wellbore area of low-pressure layers and is more severe with greater proximity to the wellbore. Through further experimentation to assess the factors influencing secondary formation damage, it is shown that the degree of secondary formation damage increases with decreasing original formation pressure, original water saturation, and permeability in the lower-pressure layer.

4284The combined use of radiofrequency-ablation and balloon-dilation (CURB) in the creation of a stable inter-atrial communication: first-in-man use for patients with severe pulmonary arterial hypertension

Background

Recent preclinical research has suggested that combined use of radiofrequency-ablation and balloon-dilation (CURB) had the potential to create a stable inter-atrial communication. However, the related clinical data is still absent.

Purpose

This study describes the first-in-man use of CURB in the patients with severe pulmonary arterial hypertension (PAH).

Methods

Under the guidance of fluoroscopy and intra-cardiac echocardiography, CURB was attempted in 3 patients with severe PAH (age: 35.0±12.1 years, one idiopathic PAH and two PAH related to repaired congenital heart disease). With the aid of 3D location system, fossae ovalis was ablated with radiofrequency. Then the graded balloon-dilation was performed after transseptal puncture, and radiofrequency-ablation was repeated around the rim of fenestration created with balloon-dilation. The exercise capacity and fenestration-size were followed up.

Results

CURB was performed successfully in all 3 patients, and pulmonary vascular resistance was 30.3±10.9 Wood units. The fenestration size was 5.0±1.0 mm (range: 4–6 mm), and systemic arterial oxygen saturation decreased by 4.7±0.6% (range: 4–5%). World Health Organization functional class increased by 1.6±0.5 (P<0.001) and cardiac index increased by 0.58±0.34 L/min/m2 (P<0.001). In addition, exercise capacity improved significantly (+63.7 meters, P<0.001). Follow-up (6.0±1.0 months; range: 5–7 months) showed that all fenestrations were stable (P=0.808), and no complication occurred.

Figure 1. The combined use of radiofrequency-ablation and balloon-dilation (CURB) was performed in the patient with severe PAH. Left figures showed the procedure of CURB. Middle figures showed the created fenestration with MSCT, and the morphology and size of fenestration was provided in the right-inferior panel. In addition, the sizes of right atrium and ventricle were alleviated with increase of left atrium. Right figures indicated that the fenestration-size was stable during follow-up (one week, one month and six months, respectively).

Conclusions

In patients with severe PAH, CURB is feasible and effective to create a stable inter-atrial communication. Further research was required to evaluate the long-term result of this novel approach.

ClinicalTrials.gov ID: NCT03554330.

Acknowledgement/Funding

National Natural Science Foundation of China (81670283) and Beijing Natural Science Foundation (7162160)

[Analysis and comparison of the clinical features and prognosis between extra - gastrointestinal stromal tumors and duodenal gastrointestinal stromal tumors]

Objective: To investigate the differences of clinicopathological features, diagnosis, treatment and prognosis between patients with extra-gastrointestinal stromal tumors (EGIST) and duodenal gastrointestinal stromal tumors (DGIST). Methods: A retrospective case - control study was performed. Case inclusion criteria: (1) tumor confirmed by histology and pathology; (2) primary tumor locating in the extra - gastrointestinal tract or duodenum; (3) without other synchronous tumors; (4) complete clinical and pathological data. Clinical data of 20 EGIST patients and 32 DGIST patients from March 2011 to September 2016 at Department of Gastrointestinal Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine were retrospectively collected and analyzed. The observational parameters included clinicopathological characteristics, treatment and prognosis conditions. Continuous data of abnormal distribution were expressed as median (range) and compared using the Mann-Whitney U-test. Survival curves were drawn by the Kaplan-Meier method and compared with the Log-rank test. Results: Of the 20 EGIST patients, 8 were males and 12 were females with age of 61.0 (30.0 to 86.0) years and of the 32 DGIST patients, 12 were males and 20 were females with age of 55.5 (27.0 to 70.0) years. Compared with DGIST patients, EGIST patients were older (U=188.000, P=0.012], had larger tumor size [10.0 (3.0 to 29.0) cm vs. 4.0 (1.5 to 10.0) cm, U=98.500, P<0.001] and higher ratio of high risk classification [85.0% (17/20) vs. 12.5% (4/32), χ(2)=26.870, P<0.001]. Among the 20 EGIST patients, 5 were diagnosed with distal metastasis and received imatinib (400 mg/d), and the other 15 patients underwent radical resection who were included in survival analysis. All the 32 DGIST patients underwent radical resection. The median follow-up of whole group was 43 (14 to 76) months. The 3-year recurrence/metastasis-free survival rate of 15 cases undergoing radical resection in the EGIST group was 85.6%, which was lower than that of the DGIST group (88.6%), and the difference was not statistically significant (P=0.745). There was no significant difference in the 3-year overall survival rate between the EGIST group (92.9%) and the DGIST group (100%) (P=0.271). Conclusions: As compared to DGIST, EGIST mostly occurs in those with older age, larger tumor size and higher risk grade. The prognosis of EGIST patients after radical resection is similar to that of DGIST patients.

[Laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis]

Objective: To investigate the clinical value of laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis. Methods: From January 2019 to June 2019, the clinical data of 6 patients diagnosed as gastric cancer with peritoneal metastasis were retrospectively analyzed in the Gastrointestinal Surgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine. Five were male and 1 was female. The median age was 69.5 (28-77) years. The median body mass index (BMI) was 22.8 (19.6-23.5). All procedures were performed under general anesthesia with endotracheal intubation. The patient's body position and facility layout in the operating room were consistent with those of laparoscopic gastrectomy. The operator's position: the main surgeon was located on the right side of the patient, the first assistant stood on the left side of the patient, and the scopist stood between the patient's legs. Surgical procedure: (1) trocar location: three abdominal trocars was adopted, with one 12 mm umbilical port for the 30° laparoscope (point A). Location of the other two trocars was dependent on the procedure of exploration or biopsy as well as the two polyester cuff position of the peritoneal dialysis catheter: Usually one 5 mm port in the anterior midline 5 cm inferior to the umbilicus point was selected as point B to ensure that the distal end of the catheter could reach the Douglas pouch. The other 5 mm port was located in the right lower quadrant lateral to the umbilicus to establish the subcutaneous tunnel tract, and the proximal cuff was situated 2 cm away from the desired exit site (point C).(2) exploration of the abdominal cavity: a 30° laparoscope was inserted from 12 mm trocar below the umbilicus to explore the entire peritoneal cavity. The uterus and adnexa should be explored additionally for women. Once peritoneal metastasis was investigated and identified, primary laparoscopic peritoneal dialysis catheter implantation was performed so as to facilitate subsequent peritoneal chemotherapy. Ascites were collected for cytology in patients with ascites. (3) peritoneal dialysis catheter placement: the peritoneal dialysis catheter was introduced into the abdominal cavity from point A. Under the direct vision of laparoscopy, 2-0 absorbable ligature was reserved at the expected fixation point of the proximal cuff (point B) for the final knot closure. Non-traumatic graspers were used to pull the distal cuff of peritoneal dialysis catheter out of the abdominal cavity through point B. The 5-mm trocar was removed simultaneously, and the distal cuff was fixed between bilateral rectus sheaths at the anterior midline port site preperitoneally. To prevent subsequent ascites and chemotherapy fluid extravasation, the reserved crocheted wire was knotted. From point C the subcutaneous tunnel tract was created before the peritoneal steath towards the port site lateral to the umbilicus. Satisfactory catheter irrigation and outflow were then confirmed. Chemotherapy regimen after peritoneal dialysis catheterization: all patients began intraperitoneal chemotherapy on the second day after surgery. On the 1st and 8th day of each 3-weeks cycle, paclitaxel (20 mg/m(2)) was administered through peritoneal dialysis catheter, and paclitaxel (50 mg/m(2)) was injected intravenously. Meanwhile, S-1 was orally administered twice daily at a dose of 80 mg·m(-2)·d(-1) for 14 consecutive days followed by 7-days rest. To observe the patients' intraoperative and postoperative conditions. Results: All the procedures were performed successfully without intraoperative complications or conversion to laparotomy. No 30 day postoperative complications were observed. The median operative time was 33.5 (23-38) min. The median time to first flatus was 1(1-2) days, and the median postoperative hospital stay was 3 (3-4) days, without short-term complications within 30 days postoperatively. The last follow-up was up to July 10, 2019, and the patients were followed for 4(1-6) months. No ascites extravasation was observed and no death occurred in the 6 patients. There was no catheter obstruction or peritoneal fluid extravasation during and after chemotherapy. Conclusion: Laparoscopic peritoneal dialysis catheter implantation was safe and feasible for patients with peritoneal metastasis of gastric cancer. The abdominal exploration, tumor staging and the abdominal chemotherapy device implantation can be completed simultaneously, which could simplify the surgical approach, improve the quality of life for patients and further propose a new direction for the development of abdominal chemotherapy.

Texture analysis of multi-phase MRI images to detect expression of Ki67 in hepatocellular carcinoma

AIM

To determine whether texture analysis of preoperative magnetic resonance imaging (MRI) images could be used to detect Ki67 expression, a widely used cell proliferation marker in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In total, 83 patients were included, 25 with low Ki67 (Ki67 ≤10%) HCC expression and 58 with high Ki67 (Ki67 ≥10%) HCC expression as demonstrated by retrospective surgical evaluation. All patients were examined using a 3 T MRI unit with one standard protocol. The region of interest was drawn manually by one radiologist. Texture analysis included histogram, co-occurrence matrix, run-length matrix, gradient, auto-regressive model, and wavelet transform features as calculated by MaZda (version 4.6; quantitative texture analysis software). The features reduced by the Fisher, probability of classification error, and average correlation coefficient (POE+ACC), mutual information were used to select the features that predicted Ki67 proliferation status with highest accuracy and then using the B11 program for data analysis and classification.

RESULTS

The misclassification rate of the principal component analysis (PCA) in the hepatobiliary phase (HBP), T2-weighted imaging (T2WI), arterial phase (AP), and portal vein phase (PVP) was 36/83 (43.37%), 35/82 (42.68%), 40/83 (48.19%), and 34/83 (40.96%), respectively. The misclassification of the linear discriminant analysis in HBP, T2WI, AP, and PVP phase was 13/83 (15.66%), 21/82 (25.61%), 9/83 (10.84%), and 8/83 (9.64%), respectively. The misclassification of the nonlinear discriminant analysis in HBP, T2WI, AP, and PVP phase was 7/83 (8.43%), 6/82 (7.32%), 5/83 (6.02%), and 7/83 (8.43%), respectively.

CONCLUSIONS

Texture analysis of HBP, AP, and PVP were helpful for predicting Ki67 expression and may provide a less-invasive method to investigate critical histopathology markers for HCC.