Bispecific antibodies have been exploited as both cancer immunodiagnostics and cancer therapeutics, which have shown promises in clinical trials in cancer imaging and therapy. To improve the anti-tumor effect, an scDb (bispecific single-chain diabody) was constructed from the variable domain genes of two scFvs (single-chain variable fragment antibodies) directed against human EGFR (epidermal growth factor receptor) and VEGFR2 (vascular endothelial growth factor receptor 2) extracellular domains. The anti-EGFR/ anti-KDR scDb was constructed into pHEN2 plasmid and expressed in Escherichia coli HB2151 host. After purification by one-step affinity chromatography of IMAC, scDb protein was characterized by Western blotting. The yield of scDb protein was 570 microg per liter medium. scDb bound to EGFR as efficiently as the parental antibody scFv-E10, while a little bit weaker than the parental antibody scFv-AK404R when bound to KDR. In conclusion, the scDb protein could bind both EGFR and KDR specifically and could be applied for further anti-tumor research.
Antibodies, Bispecific ; biosynthesis ; genetics ; Escherichia coli ; metabolism ; Humans ; Plasmids ; Protein Binding ; Receptor, Epidermal Growth Factor ; immunology ; Single-Chain Antibodies ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor Receptor-2 ; immunology

OBJECTIVE: To evaluate the potential risk of porcine endogenous retrovirus (PERV) cross-species transmission xenotransplanted with microencapsulated neonatal pig islets (NPIs). METHODS: Ten dogs were randomly divided into an experiment group and a control group. The experiment group was transplanted with microencapsulated NPIs, and the control group was transplanted with non-microencapsulated NPIs. Glucose tolerance test (GTT) was performed to evaluate the function of microencapsulated NPIs after the transplantation; immunity histochemistry was used to detect the microencapsulated NPIs in the liver of dogs which had been transplanted after 28 days; PCR and RT-PCR were performed to detect PERV and pig mitochondrial (mt) DNA in the blood samples obtained from recipients at various time points after the transplantation. RESULTS: The level of serum special porcine C peptide increased significantly after the injection of glucose for 15 approximately 30 min in dogs which were transplanted with the micro-encapsulated NPIs over 2 weeks, while special porcine C peptide could not be detected in the control group. Immunity histochemistry showed that a few microencapsulated NPIs were still alive in the liver of the dog, and the liver was not damaged. PCR and RT-PCR showed that pig mt DNA and PERV could not be detected in the experiment group 1 approximately 28 days after the transplantation, while very weak expression of that in the control could be detected in the first 4 days and disappeared 10 days after the transplantation. CONCLUSION Microencapsulated NPIs can survive and have biological function in dogs. There is no evidence of PERV replication, suggesting that the xenotransplantation with microencapsulated NPIs can prevent PERV effectively, and may have great value.
Animals ; DNA, Mitochondrial ; isolation & purification ; Dogs ; Endogenous Retroviruses ; physiology ; Islets of Langerhans ; virology ; Islets of Langerhans Transplantation ; adverse effects ; Liver ; virology ; Swine ; Transplantation, Heterologous ; Virus Replication

Objective: To study the efficacy, safety and long-term outcomes of integrated strategy of bortezomib-based induction regimens followed by autologous hematopoietic stem cell (ASCT) and maintenance therapy in Chinese multiple myeloma (MM) patients. Methods: 200 MM patients receiving integrated strategy of bortezomib--based induction regimens followed by ASCT and maintenance therapy were retrospectively and prospectively analyzed from December 1. 2006 to April 30. 2018. Results: The complete remission rates (CR) and better than very good partial remission rates (VGPR) after induction therapy, transplantation and maintenance therapy were respectively 31% and 75.5%, 51.8% and 87.7%,73.6% and 93.4%. There was no difference between 4 cycles and more than 5 cycles induction chemotherapy. The negative rate of MRD detection by flow cytometry was 17.6% and 38.2% respectively after induction and 3 months after transplantation. The negative rate of MRD gradually increased during the maintenance therapy. The success rate of high dose CTX combined with G-CSF mobilization was 95.5% and transplantation related mortality (TRM) was zero. The median time to progress (TTP) was 75.3 months and the median overall survival (OS) was 99.5 months. TTP of patients obtaining CR and negative MRD after induction were longer that those of no CR and positive MRD. TTP and OS of patients receiving triple-drug induction and ASCT in early stage were longer than those of double-drug induction and ASCT in late stage. LDH≥240 U/L, high risk cytogenetics, ISS II+III stage and HBsAg positive were prognostic factors at diagnosis. However, only MRD and high risk cytogenetics were independent prognostic factors after transplantation and maintenance therapy. The clinical characteristics of patients of TTP ≥6 years were listed below: light-chain type M protein, ISS I stage, normal level of hemoglobin and platelet, normal LDH, HBsAg negative, chromosome 17p-negative, good response and sustained good response. Conclusions Integrated strategy of bortezomib-based induction regimens followed by ASCT and maintenance therapy can significantly improve the short-term and long-term efficacy. The prognostic factors of TTP in different disease stages were different. Response to treatment, especially MRD, played a more important role in prognostic factors.

Objective: To study the efficacy, safety and long-term outcomes of integrated strategy of bortezomib-based induction regimens followed by autologous hematopoietic stem cell (ASCT) and maintenance therapy in Chinese multiple myeloma (MM) patients. Methods: 200 MM patients receiving integrated strategy of bortezomib--based induction regimens followed by ASCT and maintenance therapy were retrospectively and prospectively analyzed from December 1. 2006 to April 30. 2018. Results: The complete remission rates (CR) and better than very good partial remission rates (VGPR) after induction therapy, transplantation and maintenance therapy were respectively 31% and 75.5%, 51.8% and 87.7%,73.6% and 93.4%. There was no difference between 4 cycles and more than 5 cycles induction chemotherapy. The negative rate of MRD detection by flow cytometry was 17.6% and 38.2% respectively after induction and 3 months after transplantation. The negative rate of MRD gradually increased during the maintenance therapy. The success rate of high dose CTX combined with G-CSF mobilization was 95.5% and transplantation related mortality (TRM) was zero. The median time to progress (TTP) was 75.3 months and the median overall survival (OS) was 99.5 months. TTP of patients obtaining CR and negative MRD after induction were longer that those of no CR and positive MRD. TTP and OS of patients receiving triple-drug induction and ASCT in early stage were longer than those of double-drug induction and ASCT in late stage. LDH≥240 U/L, high risk cytogenetics, ISS II+III stage and HBsAg positive were prognostic factors at diagnosis. However, only MRD and high risk cytogenetics were independent prognostic factors after transplantation and maintenance therapy. The clinical characteristics of patients of TTP ≥6 years were listed below: light-chain type M protein, ISS I stage, normal level of hemoglobin and platelet, normal LDH, HBsAg negative, chromosome 17p-negative, good response and sustained good response. Conclusions: Integrated strategy of bortezomib-based induction regimens followed by ASCT and maintenance therapy can significantly improve the short-term and long-term efficacy. The prognostic factors of TTP in different disease stages were different. Response to treatment, especially MRD, played a more important role in prognostic factors.
Antineoplastic Combined Chemotherapy Protocols ; Bortezomib/therapeutic use* ; Follow-Up Studies ; Hematopoietic Stem Cell Transplantation ; Humans ; Induction Chemotherapy ; Multiple Myeloma/therapy* ; Retrospective Studies ; Stem Cell Transplantation ; Transplantation, Autologous ; Treatment Outcome

To study the reversal effect of docetaxel (DTX) and verapamil (VRP) liposome (DTX-VRP LP) on multidrug resistance of human breast cancer chemotherapy, DTX-VRP LP was prepared by thin film dispersion method. The particle size and zeta potential were measured by laser particle sizer. The drug loading, entrapment efficiency and the cumulative release rate of liposomes in phosphate buffer saline solution (PBS) with pH 7.4 and 6.8 were determined by ultrafiltration and dynamic dialysis, respectively. With DTX resistant human breast cancer cells (MCF-7/DTX) to study on the pharmacodynamics of liposomes in vitro and in vivo. The animal experiments were approved by the Animal Research Ethics Committee of School of Medicine of Shanghai Jiao Tong University (No. 2019-06-172). The average particle size and zeta potential of DTX-VRP LP were about 140.9 nm and -28.7 mV, respectively. The entrapment efficiency and drug loading of DTX and VRP in DTX-VRP LP were (81.7 ± 3.9)%, (2.9 ± 0.3)% and (59.6 ± 0.6)%, (1.6 ± 0.5)%, respectively. The cumulative release rate of the group of DTX-VRP LP was about 40% and 70% within 0-4 h in pH 7.4 and 6.8 PBS, respectively. It was slightly slower compared with other experimental groups. In vitro pharmacodynamics experiments, the value of IC₅₀ of DTX solution, DTX LP and DTX-VRP LP were 3.19 ± 0.6, 1.46 ± 0.48 and 1.12 ± 0.33 μmol·L^-1 on human breast cancer cells (MCF-7), respectively. The results showed the data was not much difference between the other groups and all experimental groups had strong cytotoxicity on MCF-7. However, on the MCF-7/DTX, the IC₅₀ values of the other groups were greater than 10 μmol·L^-1 while DTX-VRP LP group 7.4 ± 2.86 μmol·L^-1. The results showed DTX-VRP LP had obvious cytotoxicity with the concentration dependent reversal of multidrug resistance (MDR) of breast cancer MCF-7/DTX cells (P<0.05), the other experimental groups had no effect on MCF-7/DTX cells. The inhibitory effect of MCF-7/DTX in vivo is consistent with that in vitro. In conclusion, DTX-VRP LP could reverse the MDR of MCF-7/DTX cells.

The medicinal plants with roots and rhizomes as the medicinal parts account for about 1/3 of Chinese medicinal herbs. Root and rhizome medicinal materials are widely used in clinical practice, whereas their wild resource reserves are insufficient to meet the market demand. With the expansion of planting areas, the formation of large-scale production areas, and the increase in planting years, diseases and insect pests of these medicinal plants, which are diverse and have broad transmission routes, strong concealment, and heavy damage, have become more and more serious. The prevention and control of these diseases and insect pests is characterized by multiple ways of pesticide application, large consumption of pesticides, susceptibility to soil barrier, difficulty in the control, and unstable control efficiency. Organophosphorus pesticides(OPPs) are widely used in the cultivation of Chinese medicinal plants because of their diverse varieties, broad-spectrum, good efficacy, and low residues, and have a positive effect on the yield and quality of Chinese medicinal materials. However, the abuse of OPPs not only increases the planting cost, but also affects the quality and safety of Chinese medicinal plants, the safety of clinical use of Chinese medicine, and the ecological safety of production areas. This paper reviewed the research and development progress of OPPs, the registration status of OPPs used in root and rhizome medicinal materials, residue limit standards, residue status, and rapid detection technology progress of OPPs. This review aims to provide research ideas and references for standardizing the use of OPPs in root and rhizome medicinal materials, reducing OPP residues, and establishing a fast, efficient, accurate, and reliable method for the detection of OPP residues in Chinese herbal medicine.
Organophosphorus Compounds ; Pesticide Residues/analysis* ; Pesticides/analysis* ; Plants, Medicinal ; Rhizome/chemistry*

OBJECTIVES: To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China. METHODS: A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups. RESULTS: Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05). CONCLUSIONS There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.
Bronchopulmonary Dysplasia/epidemiology* ; Female ; Gestational Age ; Humans ; Infant ; Infant, Extremely Premature ; Infant, Newborn ; Pregnancy ; Respiratory Distress Syndrome, Newborn/epidemiology* ; Retrospective Studies ; Treatment Outcome

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent ; Brain Abscess ; Child ; Child, Preschool ; Escherichia coli ; Female ; Humans ; Hydrocephalus ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial/epidemiology* ; Retrospective Studies ; Streptococcus agalactiae ; Streptococcus pneumoniae ; Subdural Effusion ; beta-Lactamases