Objective To explore the impact of pH value of the reaction system on the properties of bovine hemoglobin modified with aldehydeated polyethylene glycol(PEG-bHb).Methods PEG-bHb conjugates were synthesized under varying pH conditions(6.0,6.5,7.4 and 8.0)of the reaction system while consistent molar ratios,temperature,and reaction time were maintained.The structural and functional attributes of PEG-bHb were characterized.Results The proportion of methemoglobin decreased with an increase in pH.In a weakly acidic reaction environment,the PEG-bHb was found to be relatively highly modified.At pH 6.5,the average number of PEG chains attached to the bHb surface was 6.86±0.38.Selective PEG modification of the N-terminal α-NH2 groups was more pronounced under weakly acidic conditions.Specifically,at pH 6.5,the modification efficiency of the N-terminal α-NH2 groups of bHb by aldehyde-activated PEG reached 95.4％for the α-chains and 99.3％for the β-chains.The PEG modification influenced the heme region microenvi-ronment of bHb,with minimal structural impact observed at pH 6.5.After modification,the oxygen affinity of PEG-bHb was enhanced,the Hill coefficient was reduced,and there were significant increases in colloid osmotic pressure,viscosity,and particle size,all of which differed markedly from the unmodified bHb group(P＜0.001).Conclusion The synthesis of PEG-bHb under weakly acidic conditions can result in a high degree of selective modification of the N-terminal α-NH2 groups and an overall high degree of modification.

Objective:To explore the efficacy and safety of anti-B cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CAR-T) for the retreatment of relapsed and refractory multiple myeloma (RRMM).Methods:The clinical data of 10 RRMM patients who received anti-BCMA CAR-T therapy for the second time (CART2) in Henan Province Hospital of Traditional Chinese Medicine due to failure or recurrence after their first anti-BCMA CAR-T (CART1) therapy from January 2017 to June 2021 were retrospectively analyzed. The treatment, efficacy and adverse events of patients receiving CART2 therapy were summarized; and the objective response rate (ORR), median duration of response (DOR) and incidence of adverse reactions were compared between CART1 and CART2.Results:Among 10 patients, 8 were males and 2 were females, with a median age of 57 years (41-70 years). Patients' 3-month ORR after CART1 therapy was 90%, and the median DOR was 16.0 months (3.0-27.0 months). CART2 used human-derived anti-BCMA CAR-T to treat 6 cases and mouse-derived anti-BCMA CAR-T to treat 4 cases. The 3-month ORR of patients receiving CART2 therapy was 40%, and the median DOR was 8.5 months (3.0-11.0 months). Among 9 patients who received mouse-derived anti-BCMA CAR-T in CART1 therapy, 4 of them received the same product again and none of them showed curative effect. Among 6 patients retreated with human-derived anti-BCMA CAR-T, 4 patients (66.7%) of them achieved partial remission (PR) or better. During CART1 therapy, 10 patients developed grade 1-2 cytokine release syndrome (CRS), and 7 patients developed different degrees of decrease in leukocyte, neutrophil absolute count (ANC) and platelet. Among patients who achieved effective outcomes after receiving CART2 therapy, 4 patients of them developed grade 1-2 CRS, and different degrees of decrease in white blood cell, ANC and thrombocytopenia. Immune effector cell-related neurotoxicity syndrome was not observed.Conclusions:Anti-BCMA CAR-T is effective and safe to retreat RRMM. The ORR and DOR of patients receiving CART2 therapy are lower than those of patients receiving CART1 therapy. CRS and cytopenia are common adverse reactions.

Objective:To explore the characteristics and influencing factors of blood carnitine metabolism in premature infants.Methods:A retrospective analysis of 37 037 neonates with negative results of genetic metabolic disease screening at Guangxi Newborn Disease Screening Center from 2018 to 2021, of which 34 517 normal full-term infants were the control group and 2 520 preterm infants were the research group.According to gestational age, the preterm infants were further divided into three groups: extremely preterm group( n=232), moderately preterm group( n=324)and late preterm group( n=1 964). According to birth weight, they were divided into three groups: very low birth weight group( n=188), low birth weight group( n=1 276)and normal birth weight group( n=1 056). According to blood collection time, they were divided into three groups: 3~7 days group( n=1 990), 8~14 days group( n=342) and 15~28 days group( n=188). Tandem mass spectrometry was used to detect the levels of 31 carnitines in dried blood spots and analyze the differences in the levels of metabolic indicators in each group. Results:Carnitine levels in preterm infants are most affected by gestational age.Adjusting the physiological and pathological conditions of premature infants and other related factors, grouped by gestational age, there were differences in the levels of 31 carnitines among the groups(all P<0.05), the smaller the gestational age, the greater the difference in carnitine levels; grouped by blood collection time, there were statistically significant differences in carnitine levels between preterm infants with different blood collection age groups and full-term 3~7 days groups(all P<0.05), and showing age-related; there are differences among 31 carnitines grouped by body weight(all P<0.05), the smaller the body weight, the greater the difference in carnitine levels.Combined with the analysis of gestational age, birth weight and blood collection date, 17 indicators including C0, C2, C3, C4, C6DC, C10, C10∶1, C12, C12∶1, C14, C14∶1, C14OH, C16, C16∶1, C18, C18∶1 and C18∶1OH are important biomarkers of carnitine metabolism in premature infants. Conclusion:Carnitine in premature newborns has different metabolic differences at different gestational ages, birth weights and blood collection ages, which provides a strong basis for establishing reference standards and interpretation of preterm infants in the laboratory in this region, and provides reasonable and effective early diagnosis and treatment for clinical practice.Meanwhile, it provides an optimized program for timely detection of carnitine deficiency and carnitine supplementation to improve nutrition of premature infants.

Objective:To explore the clinical effect of lenalidomide combined with anti-B-cell maturation antigen chimeric antigen receptor T cell (anti-BCMA CAR-T) in the treatment of relapsed/refractory multiple myeloma (RRMM).Methods:The clinical data of a patient with RRMM who underwent lenalidomide combined with anti-BCMA CAR-T therapy in Henan Province Hospital of Traditional Chinese Medicine in January 2020 were analyzed. Clinical manifestations, diagnosis and treatment were also analyzed, and the related literature was reviewed.Results:The patient was a 51-year-old man who was diagnosed as IgD-λ multiple myeloma (MM) in October 2015. The patient achieved remission after 10 courses of chemotherapy regimens including immunomodulators and proteasome inhibitors, followed by autologous hematopoietic stem cell transplantation. MM relapsed after 14 months of transplantation. His disease continued to progress after multiple chemotherapy regimens and mouse or human-derived anti-BCMA CAR-T therapy. After a conditioning chemotherapy regimen of fludarabine and cyclophosphamide, the patient took lenalidomide on day 1 and was infused human-derived anti-BCMA CAR-T cells on the next day. Grade 3 cytokine releasing syndrome (CRS) appeared after infusion, and was resolved after symptomatic treatment. Very good partial response (VGPR) was achieved on day 14 after anti-BCMA CAR-T treatment. VGPR had been maintained for more than 3 months by press time.Conclusion:Lenalidomide combined with anti-BCMA CAR-T therapy is feasible and effective in the treatment of RRMM.

Objective:To investigate the correlation between microRNA-497 (miR-497) expression and invasion and metastasis and prognosis of colorectal cancer (CRC).Methods:The expression of miR-497 in 93 CRC patients (CRC group), 30 colorectal adenoma polyps (colorectal adenomatous polyp group) and 30 healthy patients (normal control group)were detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR); meanwhile, the content of serum carcinoembryonic antigen (CEA) was detected by chemiluminescence; After 3 years follow-up, the expression of miR-497 was measured again; the correlation between the expression of miR-497 and the clinicopathological characteristics and prognosis of CRC was analyzed.Results:The expression of miR-497 in CRC group was significantly lower than that at the end of postoperative treatment, adenomatous polyps group and normal control group ( P<0.01), and the content of CEA in CRC group was significantly higher than that at the end of postoperative treatment, adenomatous polyps group and normal control group ( P<0.01); At the end of postoperative treatment, the expression of serum miR-497 in CRC group was lower than that in normal control group ( P<0.05), and the content of serum CEA was higher than that in normal control group ( P<0.05). The diagnosis positive rate of serum miR497 expression in CRC group was significantly higher than that of serum CEA ( P<0.01), and they showed no correlation ( r=0.232, P>0.05). The pre-and post-operative serum miR-497 expression levels in the recurred and metastasis group were significantly lower than those in the no postoperative recurrence and metastasis group ( P<0.01). The preoperative expression of miR-497 was related to the differentiation degree of CRC, tumor node metastasis (TNM) stage, lymph node metastasis, distant metastasis and survival period ( P<0.01), but not with the age, sex, tumor size and location of the patients ( P>0.05). Cox multivariate analysis showed that tumor differentiation, TNM stage, preoperative miR-497 expression, lymph node metastasis and distant metastasis were all independent risk factors influencing prognosis of CRC patients ( P<0.05); The survival rate of 1, 2, 3 years in the miR-497 low expression group was lower than that in the miR-497 high expression group ( P<0.05). Conclusions:The preoperative low serum miR-497 expression levels are closely relative with invasion and metastasis and poor prognosis of CRC, and can be a prognostic indicator of CRC. The reduced postoperative serum miR-497 expression levels may be a predictor of the postoperative recurrence and metastasis of CRC.

When chimeric antigen receptor T cells (CAR-T) failed to treat relapsed and refractory B-cell malignancies, some researchers try to improve the efficacy by enhancing the function of CAR-T. It is a new hotspot of drug development and clinical research, and significant achievements have been made in this area recently. Multi-targeted CAR-T, lenalidomide, decitabine, programmed death 1 inhibitor and ibrutinib can all enhance the function of CAR-T. This article reviews the recent progress of enhancing the function of CAR-T in relapsed and refractory B-cell malignancies.

Objective:To establish a disease risk prediction model for the newborn screening system of inherited metabolic diseases by artificial intelligence technology.Methods:This was a retrospectively study. Newborn screening data ( n=5 907 547) from February 2010 to May 2019 from 31 hospitals in China and verified data ( n=3 028) from 34 hospitals of the same period were collected to establish the artificial intelligence model for the prediction of inherited metabolic diseases in neonates. The validity of the artificial intelligence disease risk prediction model was verified by 360 814 newborns ' screening data from January 2018 to September 2018 through a single-blind experiment. The effectiveness of the artificial intelligence disease risk prediction model was verified by comparing the detection rate of clinically confirmed cases, the positive rate of initial screening and the positive predictive value between the clinicians and the artificial intelligence prediction model of inherited metabolic diseases. Results:A total of 3 665 697 newborns ' screening data were collected including 3 019 cases ' positive data to establish the 16 artificial intelligence models for 32 inherited metabolic diseases. The single-blind experiment ( n=360 814) showed that 45 clinically diagnosed infants were detected by both artificial intelligence model and clinicians. A total of 2 684 cases were positive in tandem mass spectrometry screening and 1 694 cases were with high risk in artificial intelligence prediction model of inherited metabolic diseases, with the positive rates of tandem 0.74% (2 684/360 814)and 0.46% (1 694/360 814), respectively. Compared to clinicians, the positive rate of newborns was reduced by 36.89% (990/2 684) after the application of the artificial intelligence model, and the positive predictive values of clinicians and artificial intelligence prediction model of inherited metabolic diseases were 1.68% (45/2 684) and 2.66% (45/1 694) respectively. Conclusion:An accurate, fast, and the lower false positive rate auxiliary diagnosis system for neonatal inherited metabolic diseases by artificial intelligence technology has been established, which may have an important clinical value.

Objective: To improve the awareness of emergency biliary obstruction (BO) disease, and to further improve the diagnosis and treatment ability of BO patients. Methods: Data of the etiology, clinical manifestations, imaging data, laboratory tests, and emergency treatment outcomes in 63 BO patients were retrospectively analyzed. Results: Common bile duct stones were the most common cause of BO patients (63.49%), followed by cholangiocarcinoma (19.05%); the most common clinical manifestations of BO patients were jaundice (90.48%), abdominal pain (87.30%), and fever (53.97%); the diagnostic ability of computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) in patients with BO was significantly higher than that of ultrasound (P<0.05), but there was no significant difference between CT and MRCP (P=1.000); compared with benign group, hemoglobin and albumin in malignant group were significantly lower, while total bilirubin and direct bilirubin were higher, with statistically significant difference (P<0.05). Most patients in BO patients improved after treatment, and the mortality rate of BO patients was 3.17%(2/63) at the end of emergency visit. Conclusions Common bile duct stones and cholangiocarcinoma are still the most common causes of emergency BO patients. The most common clinical manifestations of patients with emergency BO are jaundice, abdominal pain, and fever. Better than abdominal ultrasound, CT and MRCP have comparable diagnostic capabilities in the diagnosis of emergency BO patients. Anemia, hyperbilirubinemia and hypoproteinemia are alarm indicators for malignant tumors in emergency BO patients. Most patients can temporarily get better at the end of emergency visit.

Clinical final examination is an important link in the standardized training of residents in dermatology and quantification of evaluation indicators is one of the important parameters. In this study, the scores of clinical examinations of six candidates who participated in standardized training of residents in dermatology of Sun Yat-Sen University in June 2019 were taken as examples to explore the quantitative indicators of standardized and multi-station clinical final examinations. The indicators contained four stations and five links: skin pathological reading, skin biopsy, medical history collection and physical examination, medical record writing, and comprehensive questioning, which covered the main contents of the standardized training outline of residents in dermatology. Each evaluation indicator was refined and quantified. Finally, heuristic ideas were put forward, including a wider range of standardized and multi-station clinical examinations, introduction of new examination places, and utilization of information technology.

Taking the course's characteristics and advantages into account, this study explores the systematic implementation of standardized teaching rounds in the clinical probation sessions of the Dermatology and Venereology course , and evaluates its effect by analyzing the cases of 125 medical students from grade 2015 of Sun Yat-sen University . The results showed that the implementation of standardized teaching rounds has positive effect on the course.