Objective　To explore the possibility of R plasmid (pRST98) encoding resistance to antimicrobial agents in S. typhi mediate virulence to its host bacteria. Methods　pRST98 was transferred into a less virulent strain of S. typhimurium RIA for creating a transconjugant pRST98/RIA. The standard S. typhimurium virulence strain SR-11 which carries a 100kb virulence plasmid was used as a positive control, and RIA as a negative one. Infection with S. typhimurium was employed to assess the effect of pRST98 on the virulence of host bacteria by LD50 of peroral (p.o.) and intraperitoneal (i.p.) infection of BALB/c mice. After oral inoculation of the bacteria into BALB/c mice, mesenteric lymph nodes, spleen and liver were examined for quantity of bacteria and for the histopathological changes. The three strains were also studied for their in vitro adhesion and invasion of HEp-2, CHO and HeLa cells. Three chromosomally isogenic strains, i.e., plasmid-containing wild-type S. typhi strain, plasmid artificially cured strain and plasmid-reintroduced into the cured strain were compared for their resistance to the bactericidal activity present in human, rabbit and guinea pig sera. Results　The p.o. and i.p. LD50 of pRST98/RIA was 700 and 75 folds less than that of RIA. The bacteria counting in mesenteric lymph nodes, spleen and liver were more (P<0.05) and more severe histopathological changes were observed in pRST98 harboring S. typhimurium. However, pRST98 did not affect the adhesion and invasion of S. typhimurium to the cells. Experiments showed that pRST98 mediated resistance to serum bactericidal effect in host bacteria (P<0.05). Conclusion　This is the first report about a plasmid carrying genes coding for drug resistance and virulence in S. typhi. The data presented here suggested that novel virulence gene or related sequences, which are important in the pathogenesis of Salmonella infection could exist on pRST98.

BACKGROUND:Previous studies have shown that basic fibroblast growth factor (bFGF) can enhance fat survival rate by promoting vessel regeneration of transplanted fat.However,there is no clear conclusion addressing its effects on adipocytes.OBJECTIVE:To investigate the effect of bFGF on the proliferation and differentiation of human preadipocytes.DESIGN,TIME AND SETTING:Cytological in vitro comparison observation was conducted at the Medical College of Chinese People's Armed Police Force from March 2006 to December 2007.MATERIALS:Totally 10 samples of adipose tissue from patients undergoing abdominal liposuction were used in this study,including 1 male and 9 females,aged 21-45 years.METHODS:The human preadipocytes were obtained from human abdominal fat particles by isolation,culture and natural purity.The experiment was divided into bFGF and control groups.Cells in the control group were incubated in DMEM.Cells in the bFGF group were incubated in DMEM supplemented with 100 ng/L bFGF.MAIN OUTCOME MEASURES:Morphology of cultured cells was studied to determine the growth curve at 0,3,6,9,12,15 days following culture by inverted phase contrast microscope.Fat aggregation was observed in cells using oil red O staining.Absorbance value was examined using enzyme-linked immunosorbent assay.RESULTS:The preadipocytes represented the spindle-like character with strong proliferation.During 1 to 15 days,the preadipocytes proliferated into monolayers.Some cells became single bubble cells with lipid droplets deposited,close to maturity.The cells in bFGF group had no significant differences with the control group in cell morphology,but the amount of cells in bFGF group was 44% more than the control group.Following oil red O staining,lipid droplet was found in the preadipocytes,showing dark red.Following 15 days of incubation,the concentration of lipid droplet reached a peak.The absorbanca of bFGF group was increased 300% compared with the control group (P ＜ 0.05).CONCLUSION:The bFGF not only promote the proliferation of human preadipocytes,but also induce the differentiation of preadipocytes into mature adipocytes.

Objective To observe and compare the clinical efficacies between electroacupuncture and warm needling in treating low back pain.Method Seventy-eight eligible low back pain patients were randomized into group A of 28 cases, group B of 26 cases, and group C of 24 cases. Group A was intervened by electroacupuncture, group B was by warm needling, and group C was by medication. The short-form McGill Pain Questionnaire, Japanese Orthopaedic Association Scores (JOA), and Oswestry Disability Index were observed before and after treatment, and the therapeutic efficacies were compared.Result In group A, the McGill item scores [Sensory Pain Rating Index (S-PRI), Affective Pain Rating Index (A-PRI)] respectively after 1-week and 2-week treatment as well as in the 1-month and 3-month follow-up were significantly different from that before treatment (P<0.01,P<0.05). In group B and C, the McGill item scores after 2-week treatment and in the 1-month and 3-month follow-up were significantly different from that before treatment in the same group (P<0.01,P<0.05). The JOA and Oswestry scores were significantly changed respectively after 1-week and 2-week treatment and in the 1-month and 3-month follow-up in the three groups compared with that before treatment (P<0.05,P<0.01). After 1-week and 2-week treatment and in the 1-month and 3-month follow-up, the JOA and Oswestry scores in group A were significantly different from that in group C (P<0.05,P<0.01). In the 1-month and 3-month follow-up, the JOA scores in group B were significantly different from that in group C (P<0.05). The total effective rate was 85.7% in group A and 73.1% in group B, both significantly higher than 58.3% in group C (P<0.05). Conclusion Electroacupuncture and warm needling both can produce a significant efficacy in treating low back pain, but warm needling acts comparatively slowly and is less safe.

Objective:To study the dynamic changes of the localization and expression of nuclear transporter KPNA2 in the occurrence and development of bronchopulmonary dysplasia(BPD) in neonatal rats, and explore its role in the pathogenesis of BPD in premature infants.Methods:The BPD model of newborn SD rats was induced with 85% oxygen concentration( n=50), and the control group was inhaled with air( n=50). The lung tissue samples were collected on 1 d, 3 d, 7 d, 10 d, and 14 d, respectively, in the two groups and separated.Purification and culture of alveolar type Ⅱ epithelial cells.The distribution and expression of KPNA2 were detected by immunohistochemistry, immunofluorescence, western blot and RT-PCR. Results:Immunohistochemistry showed that KPNA2 mainly located in alveolar epithelial cells′ cytoplasm and nucleus, and BPD group was more expressive than control group.Cell immunofluorescence showed that KPNA2 in control group was mainly localized in the nucleus, and in BPD group, KPNA2 was mainly localized in the cytoplasm from 3 d to 14 d. The nuclear expression of KPNA2 was weaker than that in the control group, and the cytoplasmic expression was stronger than that in the control group.The expression trends of KPNA2 total protein, plasma protein and mRNA were basically the same.The BPD group began to increase on the 1st day ( P<0.05), and was still higher than the control group on the 14th day( P<0.05); in BPD group, KPNA2 nucleoprotein expression began to decrease on the 3rd day( P<0.01), continued to decrease to 14 days( P<0.05). Conclusion:The dysfunction of KPNA2 nuclear transport in neonatal rats exposed to hyperoxia may be an important mechanism that affects the early initiation of the DNA damage response of BPD alveolar epithelial cells.

Objective:To investigate the dynamic expression of DNA damage repair protein Nijmegen breakage syndrome protein 1(NBS1) in the neonatal rats with bronchopulmonary dysplasia(BPD), and its influence on the development and progression of BPD.Methods:Newborn rats were randomly divided into the BPD model group( n=50) and the control group( n=50) within 12 h after birth.The inhaled oxygen concentration was 80%-85% in the model group, and the control group inhaled air.In the two groups, lung tissue samples were collected on days 1, 3, 7, 10 and 14, and isolated, purified and cultured alveolar epithelial type Ⅱ cells(AEC Ⅱ). We observed pulmonary morphological changes under light microscope and evaluated alveolar development degree by radiate alveolar counts(RAC). Immunohistochemistry and cell immunofluorescence were used to observe the localization and expression of NBS1.Western blot and real-time quantitative PCR were used to detect the expression level of NBS1. Results:Compared with the control group, the RAC value in the model group was decreased significantly from 7 d after birth(control group 7.58±1.24, model group 5.42±1.24, P<0.01). Immunohistochemistry showed that NBS1 protein was mainly located in the nucleus of alveolar epithelial cells.In the model group, NBS1 was mainly expressed in the nucleus on the 1st day.With the prolonged exposure time, the number of cytoplasmic staining cells increased and the expression in the nucleus decreased.Cell immunofluorescence farther showed that NBS1 protein was mainly located in the nucleus in AEC Ⅱ.Compared with the control group, cytoplasmic staining in model group was enhanced from 3 d, while nuclear staining was gradually weakened, and was mainly located in the cytoplasm at 14 d. Western blot results showed that the expression of NBS1 protein in the model group peaked at 1 d compared to the control group(control group 0.72±0.29, model group 1.28±0.22, P<0.01), and then gradually decreased, with lower expression at 14 d compared to the control group(control group 0.73±0.19, model group 0.49±0.11, P<0.05). Similarly, the mRNA expression level of NBS1 in the model group peaked at 1 d compared to the control group(control group 1.00±0.00, model group 1.18±0.06, P<0.01), and then gradually decreased, with lower expression at 14 d than that in the control group(control group 1.07±0.13, model group 0.76±0.11, P<0.05). Conclusion:In the neonatal rats with BPD, the down-regulation expression and nuclear enrichment disorder of NBS1 may affect the DNA damage response and be one of the mechanisms mediating the onset of oxidative stress damage in BPD.

Objective To probe the reasonable range of central lymph node dissections(CLNs)for papillary thyroid carcinoma (PTC) in cN0 T1/T2 by analyzing the metastasis regulations of PTC in cN0 T1/T2.Methods Data of 891 PTC patients in cN0T1/T2 cases according to the research criterion from Oct.2013 to Sep.2017 were analyzed.All the patients were under the treatment of the same group of surgeons in Department of Thyroid Surgery of the First Affiliated Hospital of the Kunming Medical University and had undergone operation of bilateral total resection of thyroid gland and central lymph node.The clinical and pathological data were collected.Univariate and multivariate analysis were used to investigate the risk factors of central neck lymph node metastasis and high volume central neck lymph node metastasis.Results ①Univariate analysis showed that gender (P=0.002),age(P=0.002),multiform(P=0.000),nodular goiter(P=0.000)and with Hashimoto's(P=0.031)had significant influence in prevalence of CLN node metastasis.Gender(P=0.010)and tumor size(P=0.000)showed significant influence in prevalence of high volume CNL node metastasis.In multivariate analysis,age (OR=0.962,OR=2.856)and nodular goiter(OR=0.969,OR=3.012)showed the independent risk factor of CNL node metastasis and high volume CNL node metastasis.②The numbers of lesion in unilateral lesion were not correlated with IpsiCLNs and Cont-CLNs metastasis (P=0.347,P=0.653).The tumor diameter was correlated with Ipsi-CLNs and ContCLNs metastasis (P=0.010,P=0.000).The tumor diameter of bilateral multifocal carcinoma was correlated with LN-prRLN-CLNs metastasis (P=0.019).The tumor diameter of left and right unilateral single focal lesion was not correlated with LN-prRLN-CLNs metastasis(P=0.684,P=0.072).Conclusions According to the study,it is recommended that the PTC in cN0 T1/T2 should routinely undergo preventive central lymph nodes dissection in the case of technical support:①Preventive overall CLND is recommended for unilateral non-microscopic carcinoma and bilateral multiform carcinoma,especially in those older than 55.②For patients with unilateral single or multifocal microscopic carcinoma,only ipsilateral central lymph nodes dissection can be considered.③ Generally,routine dissection is not necessary for the lymph nodes of the right recurrent laryngeal nerve in the central region of the neck.However,for bilateral non-small cancers and right non-small cancers,LN-prRLN-CLNs dissection is recommended.

Objective To analyze the epidemic characteristics and dynamic changes of brucellosis in Tangshan,and explore the influencing factors in different periods,so as to provide a scientific basis for its prevention and control.Methods A retrospective analysis method was used to collect the monitoring data of brucellosis in Tangshan from 1950 to 2016 to understand its three dimension distributions in different periods.Results A total of 2 438 cases of brucellosis were reported from 1950 to 2016,the average incidence rate was 0.48/105,and no death was reported.The peak of the epidemic was in 2015,with an incidence rate of 7.12/105.The onset of the disease was marked by seasonal,the incidence from March to July accounted for 58.4％ (1 425/2 438).Cases were mainly in Qian'an,Laoting and Luannan,especially in Hui people gathering place of Jianchangying Town Qian'an City.Incidence age is mainly concentrated in 45-64 years old,accounted for 59.5％ (1 450/2 438).The sex ratio of men and women was 2.9:1.0 (1 817:621).Most patients were breeders,accounted for 69.3％ (1 689/2 438),followed by farmers,accounted for 14.2％ (346/2 438).The illness sheep was the main source of infection,the number of cases which were directly contacted with illness sheep accounted for 82.5％ (1 888/2 288).Conclusions The infection of human brucellosis in Tangshan shows an increasing trend and widening scope.It is necessary to strengthen personal protection and health education in occupational population,and strengthen quarantine and management in livestock trading to prevent and control brucellosis in Tangshan in the future.

Background/Aims: Existing hepatocellular carcinoma (HCC) prediction models are derived mainly from pretreatment or early on-treatment parameters. We reassessed the dynamic changes in the performance of 17 HCC models in patients with chronic hepatitis B (CHB) during long-term antiviral therapy (AVT). Methods: Among 987 CHB patients administered long-term entecavir therapy, 660 patients had 8 years of follow-up data. Model scores were calculated using on-treatment values at 2.5, 3, 3.5, 4, 4.5, and 5 years of AVT to predict threeyear HCC occurrence. Model performance was assessed with the area under the receiver operating curve (AUROC). The original model cutoffs to distinguish different levels of HCC risk were evaluated by the log-rank test. Results: The AUROCs of the 17 HCC models varied from 0.51 to 0.78 when using on-treatment scores from years 2.5 to 5. Models with a cirrhosis variable showed numerically higher AUROCs (pooled at 0.65–0.73 for treated, untreated, or mixed treatment models) than models without (treated or mixed models: 0.61–0.68; untreated models: 0.51–0.59). Stratification into low, intermediate, and high-risk levels using the original cutoff values could no longer reflect the true HCC incidence using scores after 3.5 years of AVT for models without cirrhosis and after 4 years of AVT for models with cirrhosis. Conclusions The performance of existing HCC prediction models, especially models without the cirrhosis variable, decreased in CHB patients on long-term AVT. The optimization of existing models or the development of novel models for better HCC prediction during long-term AVT is warranted.

Primary biliary cholangitis (PBC) is a chronic progressive cholestatic liver disease often observed in the middle-aged and elderly women and it can eventually lead to liver cirrhosis or liver failure. Osteoporosis is one of the common complications in PBC patients and is characterized by decreased bone mass and increased susceptibility to fractures. Osteoporosis and fractures caused by osteoporosis seriously affect the quality of life of PBC patients, and with the improvement of PBC treatment strategies and the increase in life expectancy, early diagnosis, prevention, and treatment of PBC with osteoporosis is of particular importance. This article briefly summarizes the epidemiology, pathogenesis, and diagnosis and treatment of patients with PBC and osteoporosis and proposes current challenges and future research directions.

Objective: To investigate the methods for qualitative pathological assessment of dynamic changes in liver fibrosis/cirrhosis after antiviral therapy in patients with chronic hepatitis B (CHB), since antiviral therapy can partially reverse liver fibrosis and cirrhosis caused by hepatitis B and semi-quantitative, rather than qualitative, pathological assessment is often used for the research on liver fibrosis regression. Methods: Previously untreated CHB patients with liver fibrosis and cirrhosis were enrolled, and liver biopsy was performed before treatment and at 78 weeks after the antiviral therapy based on entecavir. The follow-up assessment was performed once every half a year. Based on the proportion of different types of fibrous septum, we put forward the new qualitative criteria called P-I-R classification (predominantly progressive, predominantly regressive, and indeterminate) for evaluating dynamic changes in liver fibrosis. This classification or Ishak fibrosis stage was used to evaluate the change in liver fibrosis after treatment and Ishak liver inflammation score was used to evaluate the change in liver inflammation after treatment. Results: A total of 112 CHB patients who underwent liver biopsy before and after treatment were enrolled, and among these patients, 71 with an Ishak stage of ≥3 and qualified results of live biopsy were included in the final analysis. Based on the P-I-R classification, 58% (41/71) were classified as predominantly progressive, 29% (21/71) were classified as indeterminate, and 13% (9/71) were classified as predominantly regressive; there were no significant differences between the three groups in alanine aminotransferase, aspartate aminotransferase, albumin, HBeAg positive rate, HBV DNA, and liver stiffness (P < 0.05). After treatment, the proportion of predominantly progressive, indeterminate, or predominantly regressive patients changed to 11% (8/71), 11% (8/71), and 78% (55/71), respectively. Among the 35 patients who had no change in Ishak stage after treatment, 72% (25/35) were classified as predominantly regressive and had certain reductions in the Laennec score, percentage of collagen area, and liver stiffness. Conclusion This new P-I-R classification can be used to assess the dynamic changes in liver fibrosis after antiviral therapy in CHB patients.