Glycosylation modification is an important post-translational modification of proteins, which participates in regulating protein half-life, biological activity, and immunogenicity, thereby affecting their functions. Glycoproteins expressed in Pichia pastoris predominantly carry high-mannose type glycans, primarily composed of mannose residues, which starkly contrasts with the complex-type glycans synthesized by mammalian cells. This study aims to transform the high mannose glycosylation modification of P. pastoris into a hybrid glycosylation modification similar to that of mammalian cells through genetic engineering technology. We introduced the mannosidase Ⅰ gene (MDSⅠ) from Trichoderma viride and the human β-1,2-N-acetylglucosaminyltransferase I gene (GnTⅠ) into a previously constructed P. pastoris strain (∆och1) capable of producing Man₈GlcNAc₂ glycans. To precisely regulate the expression of MDSⅠ and GnTⅠ, we designed various promoter combinations, including the strong inducible AOX promoter and the constitutive GAP promoter. The receptor-binding domain (RBD, residues 377-588) of the spike protein from the Middle East respiratory syndrome coronavirus (MERS-CoV) was selected as the reporter protein for this investigation (MERS-RBD). The N-glycosylation profile of MERS-RBD was systematically analyzed using PNGase F digestion coupled with mass spectrometry. The results showed that after the knockout of och1 and the introduction of MDSⅠ and GnTⅠ genes with different promoter combinations, P. pastoris strains capable of producing GlcNAcMan₅GlcNAc₂ glycans were successfully generated. When the AOX promoter was used to control the MDSⅠ gene and the GAP promoter was used to control the GnTⅠ gene, the engineered strain exhibited the highest proportion of hybrid-type GlcNAcMan₅GlcNAc₂ glycans, which accounted for 68.38% of the total N-glycosylation. In conclusion, we successfully engineered a P. pastoris strain capable of synthesizing hybrid-type GlcNAcMan₅GlcNAc₂ glycans, establishing a foundation for subsequent research on the biosynthesis of complex-type N-glycans in P. pastoris.
Glycosylation ; Glycoproteins/genetics* ; Polysaccharides/metabolism* ; N-Acetylglucosaminyltransferases/metabolism* ; Pichia/metabolism* ; Humans ; Mannosidases/metabolism* ; Genetic Engineering ; Trichoderma/genetics* ; Recombinant Proteins/genetics* ; Saccharomycetales

BACKGROUND:Laser therapy is a non-invasive and painless treatment that is considered to be an effective method suitable for the treatment of osteoarthritis due to its simplicity and non-invasive nature.Currently,the mechanism of action of laser therapy is unclear and the results of studies on its clinical application are controversial. OBJECTIVE:To review and summarize the latest research progress of laser therapy on chondrocytes,animal experiments and clinical efficacy,and to explore the possible mechanism of laser-mediated multi-pathway biological effects,so as to provide a theoretical basis for further research on the laser treatment of osteoarthritis of the knee joint. METHODS:A literature search was performed in CNKI,WanFang Data,VIP and PubMed databases for relevant literature published from 2018 to 2023,with"laser therapy,low level laser therapy,high level laser therapy,photobiomodulation,knee osteoarthritis,chondrocytes"as the search terms in Chinese and English,respectively.Together with 14 articles searched manually,70 articles were finally included for review. RESULTS AND CONCLUSION:Laser therapy in the treatment of knee osteoarthritis is mainly categorized into two types:low-level laser therapy and high-level laser therapy.Differences in laser parameters and treatment protocols have a direct impact on laser efficacy.When appropriate parameters are used,low-level lasers show positive effects in cellular experiments,animal models,and clinical efficacy.High-level lasers have been less studied in the treatment of knee osteoarthritis,but some preliminary clinical studies have shown positive results.Cell experiments have shown that low-level laser promotes chondrocyte proliferation and cartilage matrix synthesis,thereby reducing inflammatory response.Animal experiments have shown that low-level laser can reduce the release of pro-inflammatory factors,promote cartilage matrix synthesis,inhibit matrix degradation,and effectively improve the repair process of cartilage tissue.Low-level laser is also able to reduce oxidative stress damage and relieve pain in knee osteoarthritis.In clinical trials,both low-and high-level laser can reduce patients'pain and improve functional activities.The combination of laser therapy and exercise therapy modalities may improve the therapeutic effect.Lasers may affect intracellular signaling and cellular functions through photobiological or thermodynamic effects.This provides direct evidence that laser promotes articular cartilage regeneration.

Medical Physics is an interdiscipline which is formed by applying the basic principles, methods, and techniques of physics to clinical medical research such as prevention, diagnosis, and treatment of human diseases, and it is a compulsory professional basic course for medical students. However, there are many medical students reflect that the content of this course is obscure and difficult to understand. Teaching effect is not ideal. The main reasons are that the teaching method is single and the reference materials are few. Based on the actual situation of the course, Hebei Medical University, China promotes formative evaluation from the content of teaching materials, teaching means, and other aspects. At the same time, by combining with the Internet, the digital construction has been realized, deepening the reform of the Medical Physics curriculum, and remarkable results have been achieved.

ObjectiveTo understand the serotype distribution and drug resistance of salmonella contaminated in commercially available food. MethodsSalmonella detection， including the serotypes， was conducted in food products sold in Pudong New Area from 2020 to 2022. The antimicrobial susceptibility test of 15 antibiotics was conducted by the broth microassay. ResultsA total of 118 salmonella strains were detected in 2 497 pieces of food， with a total detection rate of 4.7%. The dominant detection categories were poultry meat， livestock meat and aquatic products. The 118 salmonella strains could be divided into 24 serotypes， Salmonella enteritidis （26.4%）， Salmonella Typhimurium （16.2%） and Salmonella delpy （14.4%） were the main dominant types. Salmonella had the highest resistance rate to ampicillin （63.6%）， followed by tetracycline， chloramphenicol， cotrimoxazole and nalidixic acid. Among the three dominant serotypes， the multidrug resistance rate of Salmonella typhimurium was the highest （89.5%）， followed by Salmonella delpy （70.6%） and Salmonella enteritidis （61.3%）. ConclusionLivestock， poultry meat， and aquatic products are seriously contaminated by salmonella with diverse serotypes. The livestock meat is mainly contaminated by Salmonella typhimurium and Salmonella delpy， and the poultry meat is mainly contaminated by Salmonella enteritidis. The drug resistance spectrum is wide and the multi-drug resistance rate is high. Different from the livestock and aquatic isolates， poultry meat-derived strains have high tolerance to ampicillin， nalidixic acid and polymyxin， and carry certain potential food safety risks.

Objective:This study aimed to explore variables associated with remission rate and survival in patients with acute myeloid leukemia (AML) after induction failure and relapse.Methods:Data of 373 consecutive patients with AML were analyzed after induction failure and relapse. Binary logistics and the Cox model regression were used to identify variables associated with remission rate and outcomes.Results:In patients with AML after induction failure and relapse, the total CR+CRi rates were 50.6% and 40.3%, respectively; among those who achieved CR/CRi, the 3-year RFS rates were 34.4% and 30.4%, respectively, and the 3-year overall survival rates were 40.1% and 31.6%, respectively. In the multivariate analyses, using CLAG or FLAG regimen as a re-induction chemotherapy regimen, age <39 years and SWOG low-risk were significantly associated with higher remission rates in patients with induction failure. Male, secondary AML, SWOG high-risk, the interval from the first remission to relapse within 12 months, and bone marrow blasts ≥20% at the time of relapse were significantly associated with lower remission rates in relapsed patients. Transplantation was significantly associated with prolonged relapse-free survival and overall survival in patients achieving hematologic remission; the SWOG low-risk group was significantly associated with longer overall survival in those with induction failure; and achieving CR (not CRi) or having female gender was associated with longer RFS or overall survival in relapsed patients.Conclusion:Reinduction chemotherapy regimen, age, gender, SWOG risk, secondary AML, the interval from the first remission to relapse, and bone marrow blast percentage at the time of relapse were significantly associated with remission rates in the patients with AML after induction failure and relapse. Transplantation, SWOG low-risk, achieving CR, or female gender were associated with longer survivals in those achieving remission.

Nonsyndromic orofacial clefts (NSOC) is a common but complicated congenital malformation, resulted from complex interplay of genetic and environmental factors. In this study, certain environmental factors was demonstrated, including drug, supplementation intake, occupational exposure, environmental pollution and psychosocial factor, to be associated with increasing risk of NSOC.

OBJECTIVE: To explore the 2014 edition of the diagnostic criteria of occupational noise-induced deafness on the assessment of hearing loss in occupational health examination. METHODS: A total of 835 noise-exposed workers were selected as study subjects by cluster sampling method. The hearing threshold results were compared through two different editions of criteria: GBZ 49-2007 Diagnostic Criteria of Occupational Noise-induced Deafness( GBZ 49-2007) and GBZ 49-2014 Diagnosis of Occupational Boise-induced Deafness( GBZ 49-2014). RESULTS: The binaural high frequency threshold average calculated by GBZ 49-2007 was lower than that of GBZ 49-2014 [( 46. 8 ± 8. 1) vs( 49. 2 ± 8. 0) d B,P < 0. 01].The speech frequency threshold average of the good ear calculated by GBZ 49-2007 was lower than the monaural threshold of weighted value of the good ear of GBZ 49-2014 [( 18. 8 ± 3. 6) vs( 22. 0 ± 3. 3),P < 0. 01]. The speech frequency threshold average of the good ear and the monaural threshold of weighted value of the good ear calculated after age and sex correction using GBZ 49-2007 were lower than that calculated by using GBZ 49-2014 [( 18. 8 ± 3. 6) vs( 19. 4 ± 3. 6),( 21. 5 ±3. 4) vs( 22.0 ±3.3),P <0.05]. The detection rate of suspected occupational noise-induced deafness GBZ 49-2014 was higher than that of GBZ 49-2007( 6. 35% vs 2. 87%,P < 0. 01). CONCLUSION: In occupational health examination,the diagnostic criteria of GBZ 49-2014 can diagnose patients as suspected occupational noise-induced deafness easier than that of GBZ 49-2007.

OBJECTIVETo evaluate the outcome of radical surgery combined with adjuvant radiotherapy for patients aged over 75 years with stage II( or III( rectal cancer.

METHODSFrom 2000 to 2010, 178 patients aged over 75 years at diagnosis who underwent radical surgery in National Cancer Center, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, were selected from 3995 patients with stage II( or III( rectal cancer in the database of the above center and enrolled into this retrospective cohort study, which was approved by ethics committee of the above hospital (ClinicalTrials.gov number, NCT02312284).

RESULTSMedian age of patients was 77 years (range 75-87). There were 37 (20.8%), 69 (38.8%), and 72 (40.4%) patients with tumors locating in the high, middle and low rectum respectively; 89(50%) patients of pathological stages II( and III( respectively; 21(11.8%), 137(77%), 19(10.7%), and 1(0.6%) patients with poorly, moderately, well differentiated adenocarcinoma, and mucinous adenocarcinoma respectively. The Charlson/Deyo comorbidity index (CCI) score was 0 in the majority (73.6%) of patients. Fifty-three patients underwent abdominoperineal resection, 116 underwent low anterior resection and 9 underwent Hartmann resection. All the patients received computed tomography-based simulation and treatment planning using an anal marker in a prone or supine position. Patients were treated with linear accelerator by megavoltage photons (6MV), with 2D technique in early years and 3D conformal or simplified intensity-modulated radiotherapy technique later, at a dose of 50 Gy in 25 fractions to the pelvis within an overall treatment time of 35 days. Sixty-one patients (34.3%) received surgery combined with radiation (ART group), in whom 16 received radiation alone 117 patients did not receive radiation(NORT group). The baseline data between ART and NORT group were not significantly different(all P>0.05). There was no significant difference in 5-year overall survival between ART and NORT groups (61.0% vs. 63.0%, P=0.586). The cumulative local relapse was 10.9% and 25.4% in ART and NORT group respectively (P=0.032). Cox multivariate analysis revealed that surgery combined with radiation improved local control significantly(HR=0.27, 95%CI:0.11-0.68, P=0.005).

CONCLUSIONSFor elderly patients aged over 75 years with stage II( or III( rectal cancer, radical surgery combined with radiation does not increase the overall survival, but can improve local control rate. It is reasonable to selectively apply adjuvant radiotherapy to the elderly patients in the setting of radical surgery.

Adenocarcinoma ; radiotherapy ; surgery ; Aged ; Aged, 80 and over ; Humans ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Radiotherapy, Adjuvant ; Rectal Neoplasms ; radiotherapy ; surgery ; Retrospective Studies

OBJECTIVE: To investigate the prevalence of chronic diseases and main influencing factors in workers under high-temperature in a port of Guangzhou City.METHODS: A total of 5 603 workers under high-temperature operation condition were selected by judgment sampling method.The occupational health examination results were collected to analyze the prevalence of chronic diseases and the related influencing factors.RESULTS: The prevalence of chronic diseases was 67.6%.The prevalence rates of hyperlipidemia,hyperuricemia,hypertension and diabetes were 51.8%,29.3%,14.0% and 10.2%,respectively.Multivariate logistic regression analysis indicated that the risks of hyperlipidemia,hyperuricemia and hypertension in male workers were higher than that of female workers( P < 0.05).The prevalence risk of hyperlipidemia,hypertension and diabetes increased with the increase age( P < 0.01).With the increase of the length of high-temperature operation,the risk of hyperlipidemia,hyperuricemia and hypertension increased( P < 0.01).The risk of hypertension in regular smokers was higher than that of non-smokers( P < 0.05).The less exercise,the higher risk of hypertension and diabetes( P < 0.01).CONCLUSION: The prevalence of chronic diseases is high in workers exposed to high-temperature.The gender,age,length of high-temperature operation,smoking and exercise were the major influencing factors of chronic diseases in the workers.

[ ABSTRACT] AIM:To observe the influences of different concentrations of MG132 on apoptosis and beta-amyloid protein ( Aβ) generation in SH-SY5Y cells, and to explore the underlying mechanism.METHODS:SHSY-5Y cells were incubated with MG132 for 24 h.The final concentrations of MG132 were 2.5, 5 and 10μmol/L.The cell viability was de-termined by MTT assay.The cell apoptosis was assessed by flow cytometry.The levels of Aβwere measured by ELISA. The relative protein levels were detected by Western blot.RESULTS:In the SH-SY5Y cells, MG132 reduced the cell via-bility, induced the cell apoptosis, increased the level of Aβ, and increased the expression of the related proteins for Aβgeneration in a concentration-dependent manner.CONCLUSION: MG132 induces apoptosis and increases the levels of Aβ1-42 and Aβ1-40 by regulating the proteins related to Aβgeneration in the SH-SY5Y cells.