The hemolysin production of 19 strains of Streptococcus spp. isolated from pigs in the Jiangsu and Shanghai regions in recent years were examined. Eight isolates of Streptococcus suis type 2 from Jiangsu showed weak hemolysis on blood agar, but a stronger reaction in Todd-Hewitt broth(THB). The hemolysin belonged to the group of thiol-activated hemolysins. Nine strains of Streptoccus equi subsp. zooepidemicus showed strong hemolysis on blood agar and in THB containing 5% new-born calf serum, but no hemolysis in THB alone. This hemolysin was similar to streptolysin S(SLS). Another two isolates were atypical members of Lancefield group C Streptococcus and showed strong hemolysis on blood agar and in THB with 5% new-born calf serum, but the hemolysin was unlike either streptolysin O or SLS.

BACKGROUNDNatural disasters have been frequent in recent years. Effective treatment of patients with cardiovascular disease following natural disasters is an unsolved problem. We aimed to develop a novel miniature mobile cardiac catheterization laboratory (Mini Mobile Cath Lab) to provide emergency interventional services for patients with critical cardiovascular disease following natural disasters. A feasibility study was performed by testing the Mini Mobile Cath Lab on dogs with ST-elevation myocardial infarction (STEMI) model in a hypothetical natural-disaster-stricken area.

METHODSThe Mini Mobile Cath Lab was transported to the hypothetical natural-disaster-stricken area by truck. Coronary angiography and primary percutaneous coronary intervention (PCI) were performed on six dogs with STEMI model. The transportation and transformation of the Mini Mobile Cath Lab were monitored and its functioning was evaluated through the results of animal experiments.

RESULTSThe Mini Mobile Cath Lab could be transported by truck at an average speed of 80 km/h on mountain roads during daytime in the winter, under conditions of light snow (-15°C to -20°C/-68°F to -59°F). The average time required to prepare the Mini Mobile Cath Lab after transportation, in a wetland area, was 30 minutes. Coronary angiography, and primary PCI were performed successfully.

CONCLUSIONThis preliminary feasibility study of the use of the Mini Mobile Cath Lab for emergency interventional treatment of dogs with STEMI indicated that it may perform well in the rescue of critical cardiovascular disease following natural disasters.

Angioplasty, Balloon, Coronary ; Animals ; Cardiac Catheterization ; Cardiovascular Diseases ; therapy ; Coronary Angiography ; Disasters ; Dogs ; Electrocardiography ; Feasibility Studies ; Laboratories ; Myocardial Infarction ; therapy

Objective To monitor the co-infection status of Borrelia burgdorferi sensu lato (R.b.s.1) and spotted fever group Rickettsia (SFGR) in tourist areas of Heilongjiang province.Methods Polymerase chain reaction (PCR) was used to detect the 5S-23S rRNA intergenic spacer of B.b.s.1 and ompA of SFGR in ticks,dynamically collected from tourist areas of Heilongjiang province in 2010.Amplification products from positive ticks were sequenced,and phylogenetic analysis was conducted by Mega 5.0 software package.Results 849 ticks were collected from two tourist points,with the dominant ticks in Tiger Mountain and Jingpo Lake were Ixodes persulcatus and Haemaphysalis concinna.Regarding the Ixodes persulcatus from Tiger Mountain,the infection rates of B.b.s.1 and SFGR were 26.15％ and 10.05％.The infection rate of SFGR was 13.33％ in Haemaphysalis concinna and the B.b.s.1 was tndiscovered in the same ticks from Jingpo Lake.However,the co-infection could only be detected in Ixodes persulcatus of both tourist areas.Surveillance data showed that the major ticks were more likely to be appeared in July at Tiger Mountain and in June at Jingpo Lake.Data from the sequence analysis on B.b.s.1 showed that the B.b.s.1 in tourist areas could be classified into three different genotypes,other than B.garinii and B.afzelii.We first detected B.valaisiana-like group genotype in northeast of China.Results from the sequence analysis of SFGR positive products showed that the two DNA sequences of newly detected agents were completely the same as Rickettsia sp.HL-93 which was detected in Hulin and Rickettsia sp.H820 found in northeast,China.Conclusion The co-infection of B.b.s.1 and SFGR was detected in ticks from the tourist areas of Heilongjiang province,and data from the sequencing of specific fragment showed that various kinds of genotypes existed in this area.However; the rates of co-infectionitis-different according to environment,time and population that contributed to the kinds of and the index of ticks existed in the surveys points,also the infection rate of the ticks was studied.

pHA2 plasmid sequence,with Bacterial Artificial Chromosome(BAC) vector and the GFP expression cassette, was introduced into the UL23(TK) gene of Pseudorabies virus(PRV)strain ZJ by homologous recombination,and the recombinant PRV (rPRV-HA2) was confirmed and isolated by plaque purification. The circular genome of rPRV-HA2 was electroporated into Escherichia coli strain DH10B and then the PRV BAC (pPRV) was recovered. The transfection of pPRV into VeroE6 cells resulted in productive infection. The rescued virus isolated following transfection was indistinguishable from rPRV-HA2 in cytopathic effects (CPE) and replication curve in vitro. The growth kinetics of the viruses indicated that partial deletion of TK gene and BAC vector insertion had no effect on the viral titre and plaque size in vitro. The PRV BAC system will enable quick and reliable manipulation of the viral genome for the functional investigation on the PRV genes and the development of PRV vector in vaccine.
Animals ; Cercopithecus aethiops ; Chromosomes, Artificial, Bacterial ; genetics ; Genome, Viral ; Herpesvirus 1, Suid ; genetics ; physiology ; Pseudorabies ; virology ; Recombination, Genetic ; Swine ; Swine Diseases ; virology ; Vero Cells ; Virus Replication

This study aims to establish a novel gene-activated matrix that mimics the structure and function of extracellular matrix (ECM-m-GAM). The structure, mechanical property and release profile were also characterized. Firstly, the liposome/DNA lipoplex (LPD) was modified with cell penetrating peptide TAT. The obtained TAT-LPD was then mixed with RGD grafting hyaluronic acid solution. After addition of the matrix metalloproteinase (MMPs) sensitive crosslinker (HS-MMP-SH), hyaluronic acid was crosslinked and TAT-LPD was encapsulated in the subsequently formed hydrogel. As a result, the cell adhesion factor RGD, MMPs sensitive substrate and the efficient gene transfer vector TAT-LPD were all integrated in the hyaluronic acid hydrogel, which was named as ECM-m-GAM. The release profile of DNA from ECM-m-GAM in different release medium was evaluated with PicoGreen kits. The results suggested that the mean diameter of the spherical TAT-LPD was (263.0 ±4.30) nm. TAT-LPD was successfully encapsulated in ECM-m-GAM, which had the typical porous network structure of hydrogels. The mechanical strength of GAM was enhanced with the increasing of hyaluronic acid content. When the content was 4%, the elastic modulus of GAM reached 1 600 Pa. The highly elastic GAM may be suitable for implantation and tissue regeneration. The DNA release showed significant MMPs sensitive property. Especially, the released DNA still existed in form of nanoparticles. Bone marrow mesenchymal stem cells (BMSCs) were successfully transfected with GAM and the green fluorescent protein was expressed. The results have laid a solid foundation for future study of the cell transfection and tissue regeneration.

Objective: To investigate the efficacy of the first-day suspension method for improving the success rate of construction of nasopharyngeal carcinoma-patient derived organoids (NPC-PDO). Methods: The tumor samples of 14 nasopharyngeal carcinoma(NPC) patients, i.e.,13 males and 1 female, with a mean age of 43.0±12.0 years old, were collected from the Affiliated Tumor Hospital of Guangxi Medical University and the First Affiliated Hospital of Guangxi Medical University from January 2022 to July 2022. The tumor samples of 3 patients were digested into single cell suspension and divided into 2 groups, for comparing the efficacy of NPC-PDO construction by the direct inoculation method and the first-day suspension method. The remaining 11 patients were randomized to receive either the direct inoculation method or the first-day suspension method for NPC-PDO construction. The diameter and the number of spheres of NPC-PDO constructed by the two methods were compared by optical microscope; the 3D cell viability detection kit was used to compare the cell viability; the survival rates were compared by trypan blue staining; the success rates of the two construction methods were compared; the number of cases which could be successfully passaged for more than 5 generations and were consistent with the original tissue by pathological examination was counted; and the dynamic changes of cells in suspension overnight were observed by live cell workstation. The independent sample t-test was applied to compare the measurement data of the two groups, and the chi-square test was used to compare the classification data. Results: Compared with the direct inoculation, the diameter and the number of spheres of NPC-PDO constructed by the first-day suspension method were increased, with a higher cell activity, and the success rate of construction was obviously improved (80.0% vs 16.7%, χ²=4.41, P<0.05). In the suspension state, some of the cells aggregated and increased their ability to proliferate. Conclusion: The first-day suspension method can improve the success rate of NPC-PDO construction, especially for those whose original tumor sample size is small.
Male ; Humans ; Female ; Adult ; Middle Aged ; Nasopharyngeal Carcinoma ; China ; Microscopy ; Organoids ; Nasopharyngeal Neoplasms