Objective To establish a chronic rejection (CR) model of mouse heart transplantation and analyze its characteristics. Methods Allogeneic BALB/c and C57BL/6 mice were used as donor and recipient for heart transplantation, and intraperitoneal injection of cytotoxic T lymphocyte-associated antigen 4-immunoglobulin (CTLA4-Ig) was given 1 and 2 days after surgery. Graft survival time, donor specific antibody (DSA) level, graft pathology and inflammatory cell infiltration were observed. Results In allogeneic transplantation model, graft survival time was prolonged after CTLA4-Ig treatment [(28.2±4.1) d vs. (7.0±0.7) d, P < 0.01]. The level of serum DSA-IgG increased at 2, 3 and 4 weeks after surgery, while the level of DSA-IgM remained unchanged. Myocardial cell injury, inflammatory cell infiltration, interstitial fibrosis and C4d deposition in capillaries were aggravated 3 weeks after operation and worsened 4 weeks after operation. The infiltrated immune cells were mainly macrophages, T cells and plasma cells. Conclusions Mouse allogeneic heart transplantation combined with CTLA4-Ig successfully establishes a CR model, which provides a basis for subsequent studies on the pathogenesis and intervention of CR.

Bacterial biofilms(BF)are complex microbial communities formed by bacteria on living or abiotic surfaces.Their formation significantly enhances bacterial virulence and drug resistance and is associated with a high proportion of chronic bacterial infections,posing a serious threat to human health.The ability of traditional antibiotics and commonly used disinfectants to clear biofilms is limited,and an effective new strategy to treat BF is urgently needed.Bacteriophage,as a kind of virus that can infect and lyse bacteria,has high safety and specificity,and is considered as a promising alternative method for the treatment of BF.In this paper,the mechanism of bacteriophage anti-bacterial biofilm and the application strategies based on bacteriophage and its derivatives in the prevention and control of bacteriophage biofilm formation were reviewed,which provided new ideas for the development of efficient bacteriophage anti-bacterial biofilm methods.

Objective To establish a Nomogram model for assessing the risk of intestinal colonization by Carbapenem-Resistant Klebsiella pneumoniae(CRKP)to determine the specific probability of colonization and adopt individualized prevention strategies for the purpose of reducing the occurrence of colonization and secondary infection of neonatal CRKP.Methods A total of 187 neonates hospitalized between January 2021 and October 2022 and diagnosed with CRKP colonization by rectal swab/fecal culture as well drug sensitivity identification 48 h after admission were assigned to the CRKP group.Another 187 neonates without non-CRKP colonization during the same period were set as the non-CRKP group.All the data of the two groups were used for a retrospective analysis.The caret package in R 4.2.1 was used to randomly divide the 374 cases into the model group and validation group at a ratio of 3∶1.Then the glmnet package in R 4.2.1 was used to conduct a LASSO regression analysis over the data from the model group to determine the predictive factors for modeling and the rms software package was used to build a Nomogram model.The pROC and rms packages in R 4.2.1 were used to examine the data,analyzing the consistency indexes(Cindex),receiver operating characteristic curves(ROC),and area under the curves(AUC)and performing the internal and external validation of the efficacy of the Nomogram model via the calibration curves.Results LASSO regression analysis determined eight predictors from the 35 factors probably affecting neonatal CRKP colonization:gender,cesarean section,breastfeeding,nasogastric tube,enema,carbapenems,probiotics,and hospital stay.The Nomogram model constructed using these eight predictors as variables could predict CRKP colonization to a moderate extent,with the area under the ROC curve of 0.835 and 0.800 in the model and validation group,respectively.The Hos-mer-Lemeshow test showed that the predicted probability was highly consistent with the actual probability(the modeling group:P = 0.678>0.05;the validation group:P = 0.208>0.05),presenting a higher degree of fitting.Conclusion The Nomogram model containing such variables as gender,cesarean section,breastfeeding,nasogastric tube,enema,carbapenems,probiotics,and hospital stay is more effective in predicting the risk of neonatal CRKP colonization.Therefore,preventive measures should be individualized based on the colonization probability predicted by the Nomogram model in order to keep neonates from CRKP colonization and reduce the incidence of secondary CRKP infections among them.

Humans ; China/epidemiology* ; SARS-CoV-2 ; COVID-19

Burn induced coagulopathy (BIC) is one of the common complications after burn injury. The types and clinical manifestations of BIC vary dramatically, which frequently leads serious consequences. However, at present BIC does not attract enough attention in clinic. In order to prevent and treat BIC more effectively, the authors suggest that it is necessary to strengthen coagulation surveillance, operation management, infection control, rational application of drugs, prevention and treatment of deep vein thrombosis, relative clinical and basic research, and others.

Objective: To investigate the prevalence of soil-borne nematode infections among rural residents in Tiantai County, Zhejiang Province, so as to provide insights into improving the control strategy. Methods: According to the Zhejiang Provincial Surveillance Programme on Soil-borne Nematodiasis and Clonorchiasis, 5 administrative villages were randomly selected in Tiantai County according to geographical locations on April, 2021, and all permanent residents at ages of 3 years and older were sampled from each village using a cluster sampling method. Subjects' gender, age, occupation, education level and deworming were collected. Subjects' stool samples were collected, and soil-borne nematode eggs were detected using the modified Kato-Katz technique, and larval culture was performed using a filter-paper culture method among hookworm egg positives for identification of hookworm species. In addition, the intensity of infection was evaluated using hookworm eggs per gram stool sample. Results: A total of 1 013 residents participated in the survey, including 495 men (48.86%) and 518 women (51.14%), and there were 502 participants at ages of 51 to 70 years (49.56%), 874 farmers (86.28%) and 436 subjects with an education level of primary school (43.04%). However, no subjects received deworming. The prevalence of hookworm infections was 3.85% among the study subjects, and only Necator americanus was identified. There were 31 cases with mild infections (79.49%), 5 cases with moderate infections (12.82%) and 3 cases with severe infections (7.69%), and all infections occurred in farmers. The prevalence of hookworm infections was 3.84% among men and 3.86% among women. No hookworm infection was detected among residents at ages of <41 years, and the prevalence of hookworm infections appeared a tendency towards a rise with age among residents at ages of 51 years and older (χ2trend=24.091, P<0.001), while the prevalence of hookworm infections appeared a tendency towards a decline with educational levels among residents (χ2trend=19.534, P<0.001). The greatest prevalence of hookworm infections was found in Qianyang Village (10.95%). Conclusions Hookworm disease is the predominant type of soil-borne nematodiasis in Tiantai County, and the middle-aged and elderly farmers with a low education level are high-risk populations for soil-borne nematodiasis control.

Objective:To investigate the regulatory effect of dehydroepiandrosterone (DHEA) on the microglial activation after subarachnoid hemorrhage (SAH) in vivo and in vitro.Methods:C57BL/6 mice were used for in vivo experiments. A SAH model was induced by intravascular puncture. They were randomly divided into solvent group, model group, and DHEA pretreatment group. TUNEL staining was used to detect neuronal apoptosis level at 24 h after modeling. Iba-1/CD86 fluorescence double staining was used to detect the activation of microglia. Quantitative fluorescent polymerase chain reaction and Western blot analysis were used to detect the expression of inflammatory factors, including interleukin (IL) -1β, IL-6, tumor necrosis factor (TNF) -α, and inducible nitric oxide synthase (iNOS). The primary cultured microglia was used for in vitro experiments and it was simulated SAH by hemoglobin stimulation. They were randomly divided into control group, model group, and DHEA pretreatment group. Iba-1/CD86 fluorescence double staining was used to detect the microglial activation, and fluorescence quantitative polymerase chain reaction and Western blot analysis were used to detect the expression of inflammatory factors.Results:In vivo model experiments showed that DHEA significantly reduced neuronal apoptosis ( P<0.01) and microglial activation ( P<0.01) after SAH modeling, and IL-6 expression level significantly decreased ( P<0.01), while IL-1β, TNF-α and iNOS showed a downward trend, but there were no statistical differences. In vitro model experiments showed that DHEA could significantly inhibit microglial activation ( P<0.001) and the expression levels of various inflammatory factors ( P<0.001). Conclusions:DHEA pretreatment can reduce neuronal apoptosis and microglia activation after SAH, and it has neuroprotective effect.

OBJECTIVE： To study the effects of cimetidine on low dose rate irradiation-induced liver cell apoptosis in Beagle dogs. METHODS： Healthy male Beagle dogs were randomly divided into normal control group， model control group， positive drug group （lentinan， 21.33 mg/kg） and cimetidine low-dose， medium-dose and high-dose groups （5.33， 10.67， 21.33 mg/kg）， with 4 Beagle dogs each. Except for normal control group， other groups were given 60Co-γ accumulative irradiation （dosage rate： 0.040 8 mGy/min） for 23 d； the medication groups were given relevant medicine orally before irradiation， once a day. Twenty-four hours after stopping irradiation， TUNEL method was used to detect the apoptosis of liver cells in Beagle dogs. The percentage of apoptotic cells was calculated. The expression level of apoptosis-related proteins （Bax， Bcl-2， Caspase-3， p53） in liver tissue was detected by immunohistochemistry. RESULTS： Compared with normal control group， apoptotic cells and Bax， Caspase-3， p53 positive cells were increased significantly in liver tissue of Beagle dogs in model control group； the percentage of apoptotic cells， protein expression levels of Bax， Caspase-3 and p53 were increased significantly； Bcl-2 positive cells were decreased significantly， and its protein expression level was decreased significantly （P＜0.05 or P＜0.01）. Compared with model control group， above positive cells of liver tissue in Beagle dogs were changed to different extents in medication groups； the percentage of apoptotic cells and protein expression levels of p53 in medication groups， protein expression levels of Bax in positive drug group， cimetidine low-dose and high-dose groups as well as protein expression levels of Caspase-3 in cimetidine groups were decreased significantly； protein expression levels of Bcl-2 were increased significantly in cimetidine groups. The percentage of apoptotic cells in cimetidine medium-dose and high-dose groups as well as protein expression levels of Caspase-3 in cimetidine groups were all lower than positive control group. Protein expression level of p53 in cimetidine low-dose group was significantly higher than positive drug group （P＜0.05 or P＜0.01）. CONCLUSIONS： Cimetidine can inhibit the low dose rate irradiation-induced apoptosis of liver cells in Beagle dogs， and certainly protect liver cells against irradiation. The mechanism of it may be associated with up-regulating the protein expression of Bcl-2 and down-regulating the protein expression of Bax， Caspase-3 and p53 in liver cells.

Objective To investigate the clinical effect of lenalidomide combined with modified MP regimen in the treatment of multiple myeloma( MM) . Methods Eighty=four elderly multiple myeloma patients treated in Tangshan City Workers'Hospital from January 2013 December 2016 were enrolled in this study. The patients were randomly divided into treatment group ( 42 cases) and control group ( 42 cases) . The patients in the treatment group were given LMP regimen +α2b? interferon. The patients in the control group received the standard MPT regimen. The changes of the level of β2 microglobulin in the two groups before and after treatment were compared,and the total effective rate in the two groups was compared. Results No statistically significant difference was showed between the two groups in β2 microglobulin before treatment ( P>0. 05) . After treatment,β2 microglobulin concentration in the treatment group was (3. 11±0. 28) and was (4. 75±0. 36) in the control group,there was significant difference between two groups ( t=9. 094,P<0. 05); the total effective rate of the treatment group was 83. 33％,59. 52％ in the control group,there was significant difference between two groups ( t=5. 833,P=0. 016) . The incidence of adverse reactions in the treatment group was 9. 52％,the control group was 26. 19％,and the two groups were statistically significant ( t=3. 977,P=0. 046) . Conclusion The clinical effect of Lenalidomide combined with modified MP regimen in the treatment of MM is better than that of conventional treatment,the total effective rate is highwe,with less adverse reactions.