The CRISPR/Cas is an immune defense system acquired by prokaryotes to resist the invasion of foreign genetic materials during their evolutionary process.In recent years,it has been developed into an efficient tool for genome editing,gene regulation and molecular diagnosis.Its programmable targeting mechanism has opened the door to use this system for genome manipulation and allows for dynamic regu-lation and control of gene expression within its activity range.As one of the most flexible and cost-effec-tive techniques among existing gene modification methods,it has been widely applied in clinical disease treatment,industrial and agricultural production,sustainable dye development,chemical processing and many other fields.With the continuous investigation and exploration of the CRISPR/Cas system,a large number of studies have been reported on the engineering modification and optimization approaches of gRNA,including changing the length of the spacer region,regulating the structure of constant and varia-ble sequence parts,adding extra functional sequences through the end or middle extension,and chemical synthesis modifications,in order to reduce off-target and mutation rates,improve the efficiency of the CRISPR system,and fully stimulate the potential of CRISPR gene manipulation tools in biomedical fields.Based on this,this review will introduce the latest progress in gRNA engineering design strategies and application research of CRISPR/Cas9 and CRISPR/Cas12 systems,analyze and discuss the opportu-nities and challenges in the current gRNA engineering technology,aiming to provide ideas and reference directions for obtaining gRNAs with better performance,thereby effectively improving the ability to probe the human genomes using the CRISPR/Cas system and bringing more possibilities to programmable biology.

Background: and Purpose Myasthenia gravis (MG) is clinically heterogeneous and can be classified into subgroups according to the clinical presentation, antibody status, age at onset, and thymic abnormalities. This study aimed to determine the clinical characteristics and outcomes of generalized MG (GMG) patients based on these subgroups. Methods: Medical records of MG patients from 1976 to 2023 were reviewed retrospectively.Patients with pure ocular MG were excluded. Data on demographic, clinical characteristics, laboratory features, and outcomes were analyzed. Results: This study included 120 GMG patients. There was a slight preponderance of female patients over male patients (male:female ratio=1:1.3), with the age at onset exhibiting a bimodal distribution. Female patients peaked at a lower age (21–30 years) whereas male patients peaked at a higher age (61–70 years). Most (92%, 105 of 114) patients had positive anti-acetylcholine receptor antibodies. Five patients were also tested for anti-muscle-specific tyrosine kinase antibodies, with two showing positivity. Thymectomy was performed in 62 (52%) patients, of which 30 had thymoma, 16 had thymic hyperplasia, 7 had an involuted thymus, and 6 had a normal thymus. There were significantly more female patients (68% vs. 45%, p=0.011) with early-onset disease (<50 years old) and thymic hyperplasia (33% vs. 0%, p<0.025). Most (71%) of the patients had a good outcome based on the Myasthenia Gravis Foundation of America postintervention status. GMG patients with early-onset disease had a significantly better outcome than patients with a late onset in univariate (58% vs. 37%, p=0.041) and multivariate (odds ratio=4.68, 95% confidence interval=1.17–18.64, p=0.029) analyses. Conclusions Female patients with early-onset MG and thymic hyperplasia had significantly better outcomes, but only early-onset disease was independently associated with a good outcome. These findings are comparable with those of other studies.

Background: and Purpose Multiple acyl-CoA dehydrogenase deficiency (MADD) is an inherited disorder of fatty acid oxidation that causes lipid storage myopathy (LSM). This is the first report on MADD that describes the phenotypic and genetic features of a Malaysian cohort. Methods: Among the >2,500 patients in a local muscle biopsy database, patients with LSM were identified and their genomic DNA were extracted from muscle samples and peripheral blood.All 13 exons of the electron-transfer flavoprotein dehydrogenase gene (ETFDH) were subsequently sequenced. Fifty controls were included to determine the prevalence of identified mutations in the normal population. Results: Fourteen (82%) of the 17 LSM patients had MADD with ETFDH mutations. Twelve (86%) were Chinese and two were Malay sisters. Other unrelated patients reported that they had no relevant family history. Nine (64%) were females. The median age at onset was 18.5 years (interquartile range=16–37 years). All 14 demonstrated proximal limb weakness, elevated serum creatine kinase levels, and myopathic changes in electromyography. Three patients experienced a metabolic crisis at their presentation. Sanger sequencing of ETFDH revealed nine different variants/mutations, one of which was novel: c.998A>G (p.Y333C) in exon 9. Notably, 12 (86%) patients, including the 2 Malay sisters, carried a common c.250G>A (p.A84T) variant, consistent with the hotspot mutation reported in southern China. All of the patients responded well to riboflavin therapy. Conclusions Most of our Malaysian cohort with LSM had late-onset, riboflavin-responsive MADD with ETFDH mutations, and they demonstrated phenotypic and genetic features similar to those of cases reported in southern China. Furthermore, we report a novel ETFDH mutation and possibly the first ever MADD patients of Malay descent.

Objective:To explore the current status of surgery for portal hypertension to grasp current status and future development of surgery in China.Methods:This study is jointly sponsored by China Hepatobiliary & Pancreatic Specialist Alliance & Portal Hypertension Alliance in China (CHESS).Comprehensive surveying is conducted for basic domestic situations of surgery for portal hypertension, including case load, surgical approaches, management of postoperative complications, primary effects, existing confusion and obstacles, liver transplantation(LT), laparoscopic procedures and transjugular intrahepatic portosystemic shunt(TIPS), etc.Results:A total of 8 512 cases of portal hypertension surgery are performed at 378 hospitals nationwide in 2021.Splenectomy plus devascularization predominated(53.0%)and laparoscopy accounted for 76.1%.Primary goal is preventing rebleeding(67.0%) and 72.8% of hospitals used preventive anticoagulants after conventional surgery.And 80.7% of teams believe that the formation of postoperative portal vein thrombosis is a surgical dilemma and 65.3% of hospitals practiced both laparoscopy and TIPS.The major reasons for patients with portal hypertension not receiving LT are due to a lack of qualifications for LT(69.3%)and economic factors(69.0%).Conclusions:Surgery is an integral part of management of portal hypertension in China.However, it is imperative to further standardize the grasp of surgical indications, the handling of surgical operation and the management of postoperative complications.Moreover, prospective, multi-center randomized controlled clinical studies should be performed.

INTRODUCTION: Three doses of SARS-CoV-2 mRNA vaccines have been recommended for cancer patients to reduce the risk of severe disease. Anti-neoplastic treatment, such as chemotherapy, may affect long-term vaccine immunogenicity. METHOD: Patients with solid or haematological cancer were recruited from 2 hospitals between July 2021 and March 2022. Humoral response was evaluated using GenScript cPASS surrogate virus neutralisation assays. Clinical outcomes were obtained from medical records and national mandatory-reporting databases. RESULTS: A total of 273 patients were recruited, with 40 having haematological malignancies and the rest solid tumours. Among the participants, 204 (74.7%) were receiving active cancer therapy, including 98 (35.9%) undergoing systemic chemotherapy and the rest targeted therapy or immunotherapy. All patients were seronegative at baseline. Seroconversion rates after receiving 1, 2 and 3 doses of SARS-CoV-2 mRNA vaccination were 35.2%, 79.4% and 92.4%, respectively. After 3 doses, patients on active treatment for haematological malignancies had lower antibodies (57.3%±46.2) when compared to patients on immunotherapy (94.1%±9.56, P<0.05) and chemotherapy (92.8%±18.1, P<0.05). SARS-CoV-2 infection was reported in 77 (28.2%) patients, of which 18 were severe. No patient receiving a third dose within 90 days of the second dose experienced severe infection. CONCLUSION This study demonstrates the benefit of early administration of the third dose among cancer patients.
Humans ; SARS-CoV-2 ; COVID-19/prevention & control* ; Treatment Outcome ; Neoplasms/drug therapy* ; Hematologic Neoplasms ; Vaccination ; RNA, Messenger ; Antibodies, Viral ; Immunogenicity, Vaccine

INTRODUCTION: We investigated the knowledge, attitudes and practice (KAP) towards coronavirus disease 2019 (COVID-19) and its related preventive measures in Singaporeans aged ≥60 years. METHODS: This was a population-based, cross-sectional, mixed-methods study (13 May 2020-9 June 2020) of participants aged ≥ 60 years. Self-reported KAP about ten symptoms and six government-endorsed preventive measures related to COVID-19 were evaluated. Multivariable regression models were used to identify sociodemographic and health-related factors associated with KAP in our sample. Associations between knowledge/attitude scores and practice categories were determined using logistic regression. Seventy-eight participants were interviewed qualitatively about the practice of additional preventive measures and data were analysed thematically. RESULTS: Mean awareness score of COVID-19 symptoms was 7.2/10. The most known symptom was fever (93.0%) and the least known was diarrhoea (33.5%). Most participants knew all six preventive measures (90.4%), perceived them as effective (78.7%) and practised 'wear a mask' (97.2%). Indians, Malays and participants living in smaller housing had poorer mean scores for knowledge of COVID-19 symptoms. Older participants had poorer attitudes towards preventive measures. Compared to Chinese, Indians had lower odds of practising three out of six recommendations. A one-point increase in score for knowledge and attitudes regarding preventive measures resulted in higher odds of always practising three of six and two of six measures, respectively. Qualitative interviews revealed use of other preventive measures, for example, maintaining a healthy lifestyle. CONCLUSIONS Elderly Singaporeans displayed high levels of KAP about COVID-19 and its related preventive measures, with a positive association between levels of knowledge/attitude and practice. However, important ethnic and socioeconomic disparities were evident, indicating that key vulnerabilities remain, which require immediate attention.
Humans ; Aged ; COVID-19/epidemiology* ; SARS-CoV-2 ; Health Knowledge, Attitudes, Practice ; Cross-Sectional Studies ; Singapore/epidemiology* ; Surveys and Questionnaires

Humans ; Extremities ; Sarcoma/radiotherapy* ; Soft Tissue Neoplasms/radiotherapy* ; Neoplasm Recurrence, Local

Humans ; Parkinson Disease/diagnosis* ; Machine Learning

Background: Attitudes towards smoking, lung cancer screening, and perceived risk of lung cancer have not been widely studied in Malaysia. The primary objective of this study was to describe the factors affecting the willingness of high-risk current smokers and ex-smokers to undergo low-dose computed tomography (LDCT) screening for lung cancer. Methods: A prospective, cross-sectional questionnaire study was conducted in current smokers or ex-smokers aged between 55 and 80 years at three hospitals in Kota Kinabalu, Sabah, Malaysia. The questionnaire recorded the following parameters: perceived lung cancer risk; Prostate Lung Colon Ovarian Cancer 2012 risk prediction model excluding race and ethnicity predictor (PLCOm2012norace); demographic characteristics; psychosocial characteristics; and attitudes towards lung cancer and lung cancer screening. Results: A vast majority of the 95 respondents (94.7%) indicated their willingness to undergo screening. Stigma of lung cancer, low levels of knowledge about lung cancer symptoms, concerns about financial constraints, and a preference for traditional medication were still prevalent among the respondents, and they may represent potential barriers to lung cancer screening uptake. A desire to have an early diagnosis (odds ratio [OR], 11.33; 95% confidence interval [CI], 1.53 to 84.05; p=0.02), perceived time constraints (OR, 3.94; 95% CI, 1.32 to 11.73; p=0.01), and proximity of LDCT screening facilities (OR, 14.33; 95% CI, 1.84 to 111.4; p=0.01) had significantly higher odds of willingness to undergo screening. Conclusion Although high-risk current smokers and ex-smokers are likely to undergo screening for lung cancer, several psychosocial barriers persist. The results of this study may guide the policymakers and clinicians regarding the need to improve lung cancer awareness in our population.

Objective: To investigate the effect of arsenic and its main metabolites on the apoptosis of human lung adenocarcinoma cell line A549 and the expression of pro-apoptotic genes Bad and Bik. Methods: In October 2020, A549 cells were recovered and cultured, and the cell viability was detected by the cell counting reagent CCK-8 to determine the concentration and time of sodium arsenite exposure to A549. The study was divided into NaAsO(2) exposure groups and metobol: le expoure groups: the metabolite comparison groups were subdivided into the control group, the monomethylarsinic acid exposure group (60 μmol/L) , and the dimethylarsinic acid exposure group (60 μmol/L) ; sodium arsenite dose groups were subdivided into 4 groups: control group (0) , 20, 40, 60 μmol/L sodium arsenite NaAsO(2). Hoechst 33342/propidium iodide double staining (Ho/PI) was used to observe cell apoptosis and real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression levels of Bad and Bik mRNA in cells after exposure. Western blotting was used to detect the protein expressions of Bad, P-Bad-S112, Bik, cleaved Bik and downstream proteins poly ADP-ribose polymerase PARP1 and cytochrome C (Cyt-C) , using spectrophotometry to detect the activity changes of caspase 3, 6, 8, 9. Results: Compared with the control group, the proportion of apoptotic cells in the 20, 40, and 60 μmol/L NaAsO(2) dose groups increased significantly (P<0.01) , and the expression levels of Bad, Bik mRNA, the protein expression levels of Bad, P-Bad-S112, Bik, cleaved Bik, PARP1, Cyt-C were increased (all P<0.05) , and the activities of Caspase 3, 6, 8, and 9 were significantly increased with significantly differences (P<0.05) . Compared with the control group, the expression level of Bad mRNA in the DMA exposure group (1.439±0.173) was increased with a significant difference (P=0.024) , but there was no significant difference in the expression level of Bik mRNA (P=0.788) . There was no significant differences in the expression levels of Bad and Bik mRNA in the poison groups (P=0.085, 0.063) . Compared with the control group, the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to MMA were 0.696±0.023, 0.707±0.014, 0.907±0.031, 1.032±0.016, and there was no significant difference between the two groups (P=0.469, 0.669, 0.859, 0.771) ; the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to DMA were 0.698±0.030, 0.705±0.022, 0.908±0.015, 1.029±0.010, and there was no difference between the two groups (P=0.479, 0.636, 0.803, 0.984) . Conclusion: Sodium arsenite induces the overexpression of Bad and Bik proteins, initiates the negative feedback regulation of phosphorylated Bad and the degradation of Bik, activates the downstream proteins PARP1, Cyt-C and Caspase pathways, and mediates the apoptosis of A549 cells.
A549 Cells ; Adenosine Diphosphate Ribose/pharmacology* ; Apoptosis ; Apoptosis Regulatory Proteins ; Arsenic ; Arsenites ; Cacodylic Acid/pharmacology* ; Caspase 3 ; Caspases/pharmacology* ; Cytochromes c/pharmacology* ; Humans ; Mitochondrial Proteins/pharmacology* ; Poisons ; Propidium/pharmacology* ; RNA, Messenger ; Sincalide/pharmacology* ; Sodium Compounds ; bcl-Associated Death Protein/metabolism*