R-loop-dependent promoter-proximal termination ensures genome stability

The proper regulation of transcription is essential for maintaining genome integrity and executing other downstream cellular functions1,2. Here we identify a stable association between the genome-stability regulator sensor of single-stranded DNA (SOSS)3 and the transcription regulator Integrator-PP2A (INTAC)4-6. Through SSB1-mediated recognition of single-stranded DNA, SOSS-INTAC stimulates promoter-proximal termination of transcription and attenuates R-loops associated with paused RNA polymerase II to prevent R-loop-induced genome instability. SOSS-INTAC-dependent attenuation of R-loops is enhanced by the ability of SSB1 to form liquid-like condensates. Deletion of NABP2 (encoding SSB1) or introduction of cancer-associated mutations into its intrinsically disordered region leads to a pervasive accumulation of R-loops, highlighting a genome surveillance function of SOSS-INTAC that enables timely termination of transcription at promoters to constrain R-loop accumulation and ensure genome stability.

Evolution of magnetic surfboards and spin glass behavior in (Fe1-pGap)2TiO5

The unusual anisotropy of the spin glass (SG) transition in the pseudobrookite system Fe2TiO5has been interpreted as arising from an induced, van der Waals-like, interaction among magnetic clusters. Here we present susceptibility (χ) and specific heat data (C) for Fe2TiO5diluted with non-magnetic Ga, (Fe1-pGap)2TiO5, for disorder parameterp= 0, 0.11, and 0.42, and elastic neutron scattering data forp= 0.20. A uniform suppression ofTgis observed upon increasingp, along with a value ofχTgthat increases asTgdecreases, i.e.dχ(Tg)/dTg<0We also observeCT∝T2in the low temperature limit. The observed behavior places (Fe1-pGap)2TiO5in the category of a strongly geometrically frustrated SG.

[Analysis of factors influencing the success rate of organoid culture in 1231 cases of colorectal cancer]

Objective: To investigate the risk factors for organoid culture failure in colorectal cancer. Methods: This was a retrospective observational study. Tumor specimens were obtained from 1130 patients with colorectal cancer who had undergone surgery or biopsy and had no other concurrent malignancies at Nanfang Hospital of Southern Medical University from December 2021 to November 2022. Organoid culture was performed on 1231 tumor tissue samples. Univariate analysis and multivariate logistic regression were used to analyze the factors that might have influenced the rate of successful organoid culture of colorectal cancer tissue samples. Results: The median (range) duration of organoid culture was 7 (3-12) days. The overall rate of successful culture was 76.3% (939/1231). The rate of successful organoid cultures varied according to the sampling site, malignant ascites having the highest success rate (96.4%, 27/28), followed by liver metastases (83.1%, 54/65), lung metastases (8/10), primary tumors (76.0%, 816/1074), omental metastases (10/14), peritoneal metastases (61.5%, 16/26), ovarian metastases (3/5), and lymph node metastases (5/9). The difference in rates of successful organoid culture between primary tumors and malignant ascites was statistically significant (P=0.012), whereas none of the other rates of successful organoid culture success differed significantly (all P>0.05). The rate of successful organoid culture was 96.4% (27/28) for malignant ascites obtained by abdominal puncture, 76.5% (864/1130) for surgical specimens, and 65.8% (48/73) for endoscopic biopsies; these differences are statistically significant (χ2=10.773, P=0.005). The rate of successful organoid culture was 62.5% (40/64) in the neoadjuvant chemoradiotherapy group, which is significantly lower than in the non-adjuvant (76.9%, 787/1023) and chemotherapy groups (77.8%, 112/144) (χ2=7.134, P=0.028). Multivariate logistic regression analysis revealed that endoscopic biopsy (OR=0.557, 95%CI: 0.335-0.924, P=0.024) and neoadjuvant chemoradiotherapy (OR=0.483, 95%CI: 0.285-0.820, P=0.007) were independent risk factors for failure of organoid culture of colorectal cancer samples. Malignant ascites (OR=8.537, 95%CI:1.154-63.131,P=0.036) and abdominal puncture (OR=8.294, 95% CI: 1.112-61.882, P=0.039) were identified as independent protective factors. Conclusions: The rate of successful organoid culture was influenced by the sampling site, sampling method, and chemoradiotherapy. The rate of successful organoid culture was lower for endoscopic biopsies and in patients receiving preoperative neoadjuvant chemoradiotherapy, and higher for malignant ascites. We consider that culture of malignant ascites is preferable when peritoneal metastases are suspected.

[Wu Shou and his work Shang Han Yun Yao Quan Shu published in the Ming Dynasty]

Wu Shou was a doctor in a medical family in Qiantang, Zhejiang in the Ming Dynasty. He was promoted as a medical officer in the local government and the Imperial Academy of Medicine. His work, considered a masterpiece Shang Han Yun Yao Quan Shu was published around 1505. The series consisted of four volumes. The main content of the book focused on the taxonomy study to the Treatise on Febrile Diseases (Shang Han Lun). Wu Shou was politically accused of being a person who pursued fame and fortune but lacked medical skills because of the conflicts and contradiction between medical officials and the political service system in the period of the Chenghua and Hongzhi in the Ming Dynasty. However, his medical and academic thinking and skills for typhoid treatment shown in the book demonstrated that they were not as awful as what was described at that time.

The Quantification of Bacterial Cell Size: Discrepancies Arise from Varied Quantification Methods

The robust regulation of the cell cycle is critical for the survival and proliferation of bacteria. To gain a comprehensive understanding of the mechanisms regulating the bacterial cell cycle, it is essential to accurately quantify cell-cycle-related parameters and to uncover quantitative relationships. In this paper, we demonstrate that the quantification of cell size parameters using microscopic images can be influenced by software and by the parameter settings used. Remarkably, even if the consistent use of a particular software and specific parameter settings is maintained throughout a study, the type of software and the parameter settings can significantly impact the validation of quantitative relationships, such as the constant-initiation-mass hypothesis. Given these inherent characteristics of microscopic image-based quantification methods, it is recommended that conclusions be cross-validated using independent methods, especially when the conclusions are associated with cell size parameters that were obtained under different conditions. To this end, we presented a flexible workflow for simultaneously quantifying multiple bacterial cell-cycle-related parameters using microscope-independent methods.

[Epidemiological distribution of genotypes and sub-genotypes of hepatitis B virus in 15 ethnic groups in China]

Objective: To understand the distribution of genotypes and sub-genotypes of HBV in different ethnic groups in China. Methods: The HBsAg positive samples were selected by stratified multi-stage cluster sampling from the sample base of national HBV sero-epidemiological survey in 2020 for the amplification of S gene of HBV by nested PCR. A phylogeny tree was constructed to determine the genotypes and sub-genotypes of HBV. The distribution of genotypes and sub-genotypes of HBV were analyzed comprehensively by using laboratory data and demographic data. Results: A total of 1 539 positive samples from 15 ethnic groups were successfully amplified and analyzed, and 5 genotypes (B, C, D, I and C/D) were detected. The proportion of genotype B was higher in ethnic group of Han (74.52%, 623/836), Zhuang (49.28%, 34/69), Yi (53.19%, 25/47), Miao (94.12%, 32/34), Buyi (81.48%, 22/27). The proportions of genotype C were higher in ethnic groups of Yao (70.91%, 39/55). Genotype D was the predominant genotype in Uygur (83.78%, 31/37). Genotype C/D were detected in Tibetan (92.35%,326/353). In this study, 11 cases of genotype I were detected, 8 of which were distributed in Zhuang nationality. Except for Tibetan, sub-genotype B2 accounted for more than 80.00% in genotype B in all ethnic groups. The proportions of sub-genotype C2 were higher in 8 ethnic groups, i.e. Han, Tibetan, Yi, Uygur, Mongolian, Manchu, Hui and Miao. The proportions of sub-genotype C5 were higher in ethnic groups of Zhuang (55.56%, 15/27) and Yao (84.62%, 33/39). For genotype D, sub-genotype D3 was detected in Yi ethnic group and sub-genotype D1 was detected in both Uygur and Kazak. The proportions of sub-genotype C/D1 and C/D2 in Tibetan were 43.06% (152/353) and 49.29% (174/353). For all the 11 cases of genotype I infection, only sub-genotype I1 was detected. Conclusions: Five genotypes and 15 sub-genotypes of HBV were found in 15 ethnic groups. There were significant differences in the distribution of genotypes and sub-genotypes of HBV among different ethnic groups.

[Application of augmented reality navigation in laparoscopic and robot-assisted liver surgery]

In recent years, laparoscopic surgery and robotic surgery have been widely used, and various intraoperative image navigation systems have also developed rapidly. However, the liver itself has a complex vessel and duct system, which increase the difficulty of liver surgery. The augmented reality image navigation system combines the three-dimensional reconstructed image of the liver with the real liver anatomy, which presents the specific relationship between the tumor location and the surrounding vessels for the surgeon. Compared with other intraoperative image navigation methods, augmented reality has its unique advantages. This paper provides an overview of current advances in registration technology in augmented reality image navigation system, and focuses on its applications in liver surgery, including laparoscopic surgery and robotic surgery. Finally, the technological problems and difficulties still faced at present are summarized, and future directions worth studying in this field are proposed.

[The sources and spread of Zhong Jing Quan Shu related to Zhang Qingzi]

The original version and title of Zhong Jing Quan Shu referred to the collection of four books - Shang Han Lun, Zhu Jie Shang Han Lun, Shang Han Lei Zheng and Jin Gui Yao Lue Fang Lun, published by Zhao Kaimei in the Ming Dynasty. Then, Zhang Qingzi Shang Han Lun was written by Zhang Qingzi. After that, a Japanese scholar compiled a new collection based on Zhong Jing Quan Shu held in the Cabinet Library in Japan consisting of three books - Shang Han Lei Zheng, JinGui Yao Lue Fang Lun and Zhang Qingzi Shang Han Lun. The preface and content in this collection was adjusted for some practical purposes and was published in the second year of Manji in Japan (1659). This book, Zhang Qingzi Shang Han Lun was based on Shang Han Lun from the early and mid-Edo period of Japan. It was then returned to China in the Guangxu period of the Qing Dynasty. It was soon republished by Deng in Chengdu, with Yun Qi Zhang Jue Lu and Shang Han Ming Li Lun, added as a collection of five books with the same name Zhang Zi Qing Shang Han Lun, being popular in the late Qing Dynasty and the Republic of China. This book was understood to be from Zhong Jing Quan Shu published by Zhao Kaimei during this period. These two books were distinguished from each other when Shang Han Lun published in the Song Dynasty, drew people's attention. However, Zhang Qingzi Shang Han Lun was still believed valuable for both clinical and literature studies.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

SiC Nanoparticles Strengthened Alumina Ceramics Prepared by Extrusion Printing

Extrusion-free-form printing of alumina ceramics has the advantages of low cost, short cycle time, and high customization. However, some problems exist, such as the low solid content of ceramic paste and the unsatisfactory mechanical properties of pure alumina ceramics. In this study, SiC nanoparticles were used as a reinforcement phase added to the alumina ceramic matrix. Methylcellulose is used as the binder in the raw material system. Ammonium polyacrylate is used as a dispersant to change the rheological properties of the slurry and increase the solid content of ceramics. SiC nanoparticle-strengthened alumina ceramics were successfully prepared by the extrusion process. The relative settling height and viscosity of ceramic slurries were characterized. The sintering shrinkage of composite ceramics was tested. The flexural strength, fracture toughness, and hardness of the ceramics were characterized. The strengthening and toughening mechanisms of the composite ceramics were further explained by microscopic morphology analysis. Experimental results show that when the content of the dispersant is 1 wt.%, the rheological properties of the slurry are the best. Maximum measured bending strength (227 MPa) and fracture toughness (5.35 MPa·m^1/2) were reached by adding 8 wt% SiC nanoparticles; compared with pure alumina ceramics, flexural strength and fracture toughness increased by 42% and 41%, respectively. This study provides a low-cost and effective method for preparing ceramic composite parts.

[Challenges to global pertussis prevention and control]

Pertussis is an acute, highly infectious respiratory disease caused by Bordetella pertussis, and is one of the leading causes of infant disease and death worldwide. The pertussis vaccine has been used in the expanded program on immunization globally since 1974 and the vaccination coverage remains high. In recent years, the pertussis incidence rate increased, even pertussis outbreaks occurred, in more and more countries or areas after years with low incidence level. The disease burden of pertussis has been seriously underestimated, and the prevention and control of pertussis is facing many challenges. This article reviews the epidemic status of pertussis worldwide, the factors affecting the reemergence of pertussis, and the challenges in the prevention and control to provide a reference for prevention and control of pertussis.

Effect of intravesical mitomycin compared with gemcitabine on the treatment non-muscle invasive bladder cancer: A meta-analysis

INTRODUCTION

We performed a meta-analysis to evaluate the effect of intravesical mitomycin compared with gemcitabine on the treatment of non-muscle invasive bladder cancer.

METHODS

A systematic literature search up to November 2021 was done and 6 studies included 389 subjects with non-muscle invasive bladder cancer at the start of the study; 197 of them were provided with intravesical-mitomycin and 192 with intravesical gemcitabine. The studies reported the relationships about the effect of intravesical mitomycin compared with gemcitabine on the treatment of non-muscle invasive bladder cancer. We calculated the odds ratio (OR) with 95% confidence intervals (CIs) to assess the effect of intravesical mitomycin compared with gemcitabine on the treatment of non-muscle invasive bladder cancer using the dichotomous method with a random or fixed-effect model.

RESULTS

Intravesical mitomycin had significantly higher recurrence rates (OR, 2.41; 95% CI, 1.43-4.08, p=0.001) and chemical cystitis (OR, 4.39; 95% CI, 2.27-8.51, p<0.001) compared to intravesical gemcitabine in subjects with non-muscle invasive bladder cancer. However, intravesical mitomycin had no significant difference in its effect on hematuria (OR, 1.71; 95% CI, 0.68-4.33, p=0.26), skin reaction (OR, 2.04; 95% CI, 0.59-7.07, p=0.26), and liver and kidney functions damage (OR, 1.96; 95% CI, 0.35-10.96, p=0.44) compared to intravesical gemcitabine in subjects with non-muscle invasive bladder cancer.

CONCLUSIONS

Intravesical mitomycin had significantly higher recurrence rates and chemical cystitis and no significant difference in its effect on hematuria, skin reaction, and liver and kidney functions damage compared to intravesical gemcitabine in subjects with non-muscle invasive bladder cancer. Further studies are required to validate these findings.

GC-MS and UHPLC-QTOFMS-assisted identification of the differential metabolites and metabolic pathways in key tissues of Pogostemon cablin

Pogostemon cablin is an important aromatic medicinal herb widely used in the pharmaceutical and perfume industries. However, our understanding of the phytochemical compounds and metabolites within P. cablin remains limited. To our knowledge, no integrated studies have hitherto been conducted on the metabolites of the aerial parts of P. cablin. In this study, twenty-three volatile compounds from the aerial parts of P. cablin were identified by GC-MS, predominantly sesquiterpenes. Quantitative analysis showed the highest level of patchouli alcohol in leaves (24.89 mg/g), which was 9.12 and 6.69-fold higher than in stems and flowers. UHPLC-QTOFMS was used to analyze the non-volatile compounds of leaf, stem and flower tissues. The differences in metabolites between flower and leaf tissues were the largest. Based on 112, 77 and 83 differential metabolites between flower-leaf, flower-stem and leaf-stem, three tissue-specific biomarkers of metabolites were identified, and the differential metabolites were enriched in several KEGG pathways. Furthermore, labeling differential metabolites in the primary and secondary metabolic pathways showed that flowers accumulated more lipids and amino acids, including proline, lysine and tryptophan; the leaves accumulated higher levels of terpenoids, vitamins and flavonoids, and stems contained higher levels of carbohydrate compounds. Based on the role of acetyl coenzyme A, the distribution and possible exchange mechanism of metabolites in leaves, stems and flowers of P. cablin were mapped for the first time, laying the groundwork for future research on the metabolites in P. cablin and their regulatory role.

Management of traumatic peripheral artery pseudoaneurysm: A 10-year experience at a single center

Purpose

This study aimed to report our 10-year experience with the management of iatrogenic (penetrating trauma) and traumatic (blunt or penetrating trauma) peripheral artery pseudoaneurysms, based on data from a tertiary referral center.

Methods

From January 2012 to December 2021, the medical records of consecutive patients with iatrogenic and traumatic peripheral artery pseudoaneurysms were retrospectively reviewed. Patient demographics, clinical features, imaging data, treatment details, and follow-up results were analyzed.

Results

Sixty-one consecutive patients were included in this study; 48 (79%) were men and 13 (21%) women, with a mean age of 49.4 ​± ​13.4 years (range 24-73 years). There were 42 patients (69%) who underwent open surgery, 18 (29%) undergoing endovascular embolization or stent implantation, and one (2%) undergoing ultrasound-guided thrombin injection. All patients successfully underwent open or interventional treatment. The median follow-up was 46.8 months (2.5-117.9 months), and the overall reintervention rate was 10%. Of these, one (5%) patient in the interventional treatment group and five (12%) patients in the open surgery group underwent reintervention. The overall complication rate was 8%, with complications occurring only in the open surgery group. No deaths occurred in the peri-operative period. No late complications, such as thrombosis or pseudoaneurysm recurrence, were observed.

Conclusion

Peripheral artery pseudoaneurysms arising from iatrogenic or traumatic causes can be effectively treated by both open surgery and interventional procedures in selected patients with acceptable mid- and long-term outcomes.

Interplay between post-myocardial infarction ejection fraction and atrial fibrillation: implications for ischemic stroke

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Singapore Ministry of Health’s National Medical Research Council

Background

There are little data on the interplay between post-acute myocardial infarction (MI), left ventricular systolic dysfunction and atrial fibrillation (AF) and the impact on subsequent acute ischemic stroke (AIS), particularly among patients with moderately reduced ejection fraction (EF).

Purpose

We aimed to study the association between low EF, AF and the risk and severity of AIS.

Methods

This study linked national, population-based data from the Singapore Myocardial Infarction Registry with the Singapore Stroke Registry from 2007 to 2018. The EF and AF status were recorded during the index MI hospitalization. Patients were grouped based on an EF of ≥50% or &lt;50%. An additional grouping of patients with AMI in 2008 to 2018 and EF of ≥50% (normal EF), 40-49% (mildly reduced EF) or &lt;40% (reduced EF) was done. The primary outcome of interest was the risk of developing an AIS after an AMI. The secondary outcome of interest was the National Institute of Health Stroke Scale (NIHSS) across the different strata of EF among AMI patients with subsequent AIS.

Results

There were 64512 patients available for analysis. The median age was 65.7 and 69.5% were male. The median duration from MI to AIS was 16.9 (IQR 1.6-46.1) months. Low EF &lt;40% was independently associated with subsequent AIS (adjusted HR 1.18, 95% CI 1.10-1.27), as was EF 40-49% (adjusted HR 1.16, 95% CI 1.06-1.27). Among patients with AF, EF&lt;50% was not a statistically significant predictor of AIS (adjusted HR 1.08, 95% CI 0.96-1.23). In patients without AF, the mildly reduced EF group had an increased aHR of AIS of 1.18 (95% CI 1.06-1.31), but not those with AF (aHR 1.03, 95% CI 0.87-1.23). The cubic spline curves of continuous EF against relative hazard for stroke stratified by presence of AF is shown in Figure 1. Patients with low EF without AF had highest median NIHSS score during subsequent AIS (EF &lt;40% NIHSS 6-9; EF 40-49% NIHSS 4; EF ≥50% NIHSS 4).

Conclusions

Reduced and moderately reduced EF post-MI was independently associated with subsequent AIS and was associated with increased AIS severity in patients without AF but not in those with AF. Further research is needed to mitigate the risk of late AIS among post-MI patients with reduced EF along with AF.

Impact of meltwater flow intensity on the spatiotemporal heterogeneity of microbial mats in the McMurdo Dry Valleys, Antarctica

The meltwater streams of the McMurdo Dry Valleys are hot spots of biological diversity in the climate-sensitive polar desert landscape. Microbial mats, largely comprised of cyanobacteria, dominate the streams which flow for a brief window of time (~10 weeks) over the austral summer. These communities, critical to nutrient and carbon cycling, display previously uncharacterized patterns of rapid destabilization and recovery upon exposure to variable and physiologically detrimental conditions. Here, we characterize changes in biodiversity, transcriptional responses and activity of microbial mats in response to hydrological disturbance over spatiotemporal gradients. While diverse metabolic strategies persist between marginal mats and main channel mats, data collected from 4 time points during the austral summer revealed a homogenization of the mat communities during the mid-season peak meltwater flow, directly influencing the biogeochemical roles of this stream ecosystem. Gene expression pattern analyses identified strong functional sensitivities of nitrogen-fixing marginal mats to changes in hydrological activities. Stress response markers detailed the environmental challenges of each microhabitat and the molecular mechanisms underpinning survival in a polar desert ecosystem at the forefront of climate change. At mid and end points in the flow cycle, mobile genetic elements were upregulated across all mat types indicating high degrees of genome evolvability and transcriptional synchronies. Additionally, we identified novel antifreeze activity in the stream microbial mats indicating the presence of ice-binding proteins (IBPs). Cumulatively, these data provide a new view of active intra-stream diversity, biotic interactions and alterations in ecosystem function over a high-flow hydrological regime.

Isolation and Characterization of SPOTTED LEAF42 Encoding a Porphobilinogen Deaminase in Rice

The formation and development of chloroplasts play a vital role in the breeding of high-yield rice (Oryza sativa L.). Porphobilinogen deaminases (PBGDs) act in the early stage of chlorophyll and heme biosynthesis. However, the role of PBGDs in chloroplast development and chlorophyll production remains elusive in rice. Here, we identified the spotted leaf 42 (spl42) mutant, which exhibited a reddish-brown spotted leaf phenotype. The mutant showed a significantly lower chlorophyll content, abnormal thylakoid morphology, and elevated activities of reactive oxygen species (ROS)-scavenging enzymes. Consistently, multiple genes related to chloroplast development and chlorophyll biosynthesis were significantly down-regulated, whereas many genes involved in leaf senescence, ROS production, and defense responses were upregulated in the spl42 mutant. Map-based cloning revealed that SPL42 encodes a PBGD. A C-to-T base substitution occurred in spl42, resulting in an amino acid change and significantly reduced PBGD enzyme activity. SPL42 targets to the chloroplast and interacts with the multiple organelle RNA editing factors (MORFs) OsMORF8-1 and OsMORF8-2 to affect RNA editing. The identification and characterization of spl42 helps in elucidating the molecular mechanisms associated with chlorophyll synthesis and RNA editing in rice.

A Multicentre Clinical Study of Sarcoma Personalised Treatment Using Patient-Derived Tumour Xenografts

AIMS

Medication for advanced sarcomas has not improved for three decades. Patient-derived tumour xenografts (PDTX) are a promising solution for developing new therapies and real-time personalised medicine because of their highly effective prediction of drug efficacy. However, there is a dearth of PDTX models for sarcomas due to the scarcity and heterogeneity of the disease.

MATERIALS AND METHODS

A multicentre clinical collaborative study (ChiCTR-OOC-17013617) was carried out. Fresh patient tumour tissues via resection or biopsy were used for the PDTX set-up. The standard medical care chosen by the physician was given to the patient, in parallel with testing on multiple regimens. The outcomes of patients' responses and PDTX tests were compared. Comprehensive analyses were carried out to assess the clinical value of PDTX for the treatment of sarcomas. Living tissues from successfully engrafted cases were deposited into a repository.

RESULTS

Forty-two cases, including 36 bone sarcomas and six soft-tissue sarcomas, were enrolled; the overall engraftment rate was 73.8%. Histopathological examination showed a 100% consistency between primary tumours and tumour grafts. The engraftment rate was independent of age, gender and sampling methods, but was associated with subtypes of tumour. The outgrowth time of tumour grafts could be associated with prognosis. Major somatic mutations in tumour grafts occurred primarily in common tumour driver genes. Poor prognosis was associated with the KMT2C mutation. A drug efficacy test showed complete concordance between the PDTX model and patients' responses in 17 regimens.

CONCLUSION

PDTX is an ideal preclinical model for sarcomas because of its faithful preservation of the heterogeneity of the disease, a satisfactory engraftment rate and high accuracy in its prediction of drug efficacy.

OsPHS1 is required for both male and female gamete development in rice

Meiosis plays an essential role in the production of male and female gametes. Extensive studies have elucidated that homologous chromosome association and pairing are essential for crossing-over and recombination of chromosomal segments. However, the molecular mechanism of chromosome recognition and pairing remains elusive. Here, we identified a rice male-female sterility mutant plant. Cytological observations showed that the development of both pollen and embryo sacs of the mutant were abnormal due to defects in homologous chromosome recognition and pairing during prophase I. Map-based cloning revealed that Os06g0473000 encoding a poor homologous synapsis 1 (PHS1) protein is the candidate target gene, which was confirmed by knockout using CRISPR/Cas9 technology. Sequence analysis revealed a single base mutation (G > A) involving the junction of the fourth exon and intron of OsPHS1, which is predicted to alter splicing, resulting in an Osphs1 mutant. Expression pattern analysis indicated that OsPHS1 expression levels were mainly expressed in panicles at the beginning of meiosis. Subcellular localization analysis demonstrated that the OsPHS1 protein is situated in the nucleus and cytoplasm. Taken together, our results suggest an important role for OsPHS1 in homologous chromosome pairing in both male and female gametogenesis in rice.

[Double-edged sword of opioids in the treatment of cancer pain: hyperalgesia]

Hyperalgesia is an occult complication during the treatment of cancer pain, not only related to opioids, but also pertaining to the tumor itself and cancer therapeutic drugs. Yet it is often ignored by clinicians. Patients with cancer pain who were treated with opioids often have sensory abnormalities presented with reduced pain threshold and increased sensitivity to nociceptive stimuli. This phenomenon is clinically called opioid-induced hyperalgesia (OIH). However, due to the complexity of pathogenesis and the lack of clinical diagnostic criteria, the pain management of cancer patients is still facing great challenges. Therefore, this article focuses on the clinical diagnosis, pathogenesis, prevention and treatment of hyperalgesia related to cancer pain treatment, in order to provide a basis for optimal use of opioids in the future.