[Survey of Helicobacter pylori levofloxacin and clarithromycin resistance rates and drug resistance genes in Ningxia, 2020-2022].

Objective: To explore the rate of Helicobacter pylori (Hp) resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia, and to assess the concordance between phenotypic resistance and genotypic resistance. Methods: Cross-sectional study. Patients diagnosed with Hp infection in 14 hospitals in Ningxia region from February 2020 to May 2022 were retrospectively selected. Hp strains were isolated from gastric biopsy specimens of Hp-infected patients and subjected to phenotypic drug sensitivity testing and detection of resistance genes to analyze the rate of Hp resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia region; and the concordance rate and Kappa concordance test were used to assess the concordance between phenotypic resistance and genotypic resistance. Results: A total of 1 942 Hp strains were isolated and cultured, and among the infections, 1 069 cases (55.0%) were male and 873 cases (45.0%) were female, aged (50.0±12.5) years (15-86 years). The rates of Hp resistance to levofloxacin and clarithromycin in Ningxia were 42.1% (818/1 942) and 40.1% (779/1 942), respectively, and the rate of dual resistance to both was 22.8% (443/1 942). The rate of resistance to levofloxacin and clarithromycin of Hp strains from female patients was higher than in male patients (levofloxacin: 50.4%(440/873) vs 35.4%(378/1 069); clarithromycin: 44.4%(388/873) vs 36.6%(391/1 069), both P<0.001). Among the GyrA gene mutations associated with levofloxacin resistance, the differences in mutation rate of amino acid at positions 87 and 91 were statistically significant in both drug-resistant and sensitive strains(both P<0.001), except for Asn87Thr. Hp strains were statistically significant for levofloxacin (Kappa=0.834, P<0.001) and clarithromycin (Kappa=0.829, P<0.001) had good concordance in resistance at the phenotypic and genotypic levels. Conclusion: The resistance of Hp to levofloxacin and clarithromycin in Ningxia region is severe, and there is good consistency between genotypic and phenotypic resistance.

[Impact of combined nerve blocks on the outcome of hip replacement in elderly patients with acute cerebral infarction].

Objective: To investigate the impact of ultrasound-guided lumbar plexus, sciatic nerve and L1 paravertebral combined nerve blocks on the outcomes of elderly acute cerebral infarction patients with femoral neck fracture who underwent hip replacement. Methods: The clinical data of 114 elderly acute cerebral infarction patients with femoral neck fracture and underwent artificial hip replacement surgery from May 2013 to September 2018 in Renmin Hospital of Wuhan University were retrospectively analyzed. The patients were divided into two groups based on the different anesthetic methods they received: general anesthesia (G group, n=48), lumbar plexus, sciatic nerve and L1 paravertebral combined nerve blocks (N group, n=66). The operation time, anesthesia time, blood loss, urine volume, norepinephrine dose, length of intensive care unit (ICU) stay, hospital mortality and postoperative 6-month mortality were observed and compared between the two groups. The mini-mental state examination (MMSE) scores and the national institute of health stroke scale (NIHSS) scores were evaluated, respectively. Meanwhile, plasma D-Dimer and S100ß levels were measured 1 d before surgery, 3 d and 7 d after surgery. Results: There were no significant differences in the baseline characteristics, operation time, anesthesia time, blood loss and length of ICU stay between the two groups (all P>0.05). Compared with group G, the dosage of norepinephrine [(86±23) µg vs (184±28) µg], hospital mortality [7.6% (5/66) vs 25.0% (12/48)] and postoperative 6-month mortality [12.1% (8/66) vs 31.3% (15/48)] were significantly decreased in group N, while the urine volume [(265±58) ml vs (160±55) ml] was significantly increased (all P<0.01). The MMSE scores (9.9±3.0 vs 14.6±2.4) in group N were significantly higher than those in the group G 3 d after surgery, while the NIHSS scores (15.3±3.2 vs 9.9±3.5), plasma D-Dimer [(10.8±2.5) mg/L vs (7.3±2.2) mg/L] and S100ß levels [(326±35) ng/L vs (276±29) ng/L] were significantly lower than those in group G (all P<0.01). Conclusion: Combined nerve blocks can reduce the mortality of acute cerebral infarction patients undergoing hip replacement surgery, and improve the brain function and prognosis of the patients.

[Impact of inflammatory reaction levels and culprit plaque characteristics on preprocedural thrombolysis in myocardial infarction flow grade in patients with ST-segment elevation myocardial infarction].

Objective: To determine the impact of inflammatory reaction levels and the culprit plaque characteristics on preprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: The is a retrospective study. A total of 1 268 STEMI patients who underwent pre-intervention optical coherence tomography (OCT) examination of culprit lesion during emergency PCI were divided into 2 groups by preprocedural TIMI flow grade (TIMI 0-1 group (n =964, 76.0%) and TIMI 2-3 group (n =304, 24.0%)). Baseline clinical data of the 2 groups were collected; blood samples were collected for the detection of inflammatory markers such as high sensitivity C-reactive protein (hsCRP), myocardial injury marker, blood lipid, etc.; echocardiography was used to determine left ventricular ejection fraction; coronary angiography and OCT were performed to define the lesion length, diameter stenosis degree of the infarct-related arteries, presence or absence of complex lesions, culprit lesion type, area stenosis degree and vulnerability of culprit plaques. Multivariable logistic regression analysis was performed to identify independent correlation factors. The receiver operating characteristic (ROC) curve of continuous independent correlation factors was analyzed, and the best cut-off value of TIMI 0-1 was respectively determined according to the maximum value of Youden index. Results: The mean age of 1 268 STEMI patients were (57.6±11.4) years old and 923 cases were males (72.8%). Compared with TIMI 2-3 group, the patients in TIMI 0-1 group were older and had higher N-terminal-pro-B-type natriuretic peptide level, lower cardiac troponin I (cTnI) level, lower left ventricular ejection fraction, and higher hsCRP level (5.16(2.06, 11.78) mg/L vs. 3.73(1.51, 10.46) mg/L). Moreover, the hsCRP level of patients in TIMI 0-1 group was higher in the plaque rupture subgroup (all P<0.05). Coronary angiography results showed that compared with TIMI 2-3 group, the proportion of right coronary artery (RCA) as the infarct-related artery was higher, the angiographical lesion length was longer, minimal lumen diameter was smaller, and diameter stenosis was larger in TIMI 0-1 group (all P<0.05). The prevalence of plaque rupture was higher (75.8% vs. 61.2%) in TIMI 0-1 group. Plaque vulnerability was significantly higher in TIMI 0-1 group than that in TIMI 2-3 group with larger mean lipid arc (241.27°±46.78° vs. 228.30°±46.32°), more thin-cap fibroatheroma (TCFA, 72.4% vs. 57.9%), more frequent appearance of macrophage accumulation (84.4% vs. 70.7%) and cholesterol crystals (39.1% vs. 25.7%). Minimal flow area was smaller [1.3(1.1-1.7)mm2 vs. 1.4(1.1-1.9)mm2, all P<0.05] and flow area stenosis was higher (78.2%±10.6% vs. 76.3%±12.3%) in TIMI 0-1 group. Multivariable analysis showed that mean lipid arc>255.55°, cholesterol crystals, angiographical lesion length>16.14 mm, and hsCRP>3.29 mg/L were the independent correlation factors of reduced preprocedural TIMI flow grade in STEMI patients. Conclusions: Plaque vulnerability and inflammation are closely related to reduced preprocedural TIMI flow grade in STEMI patients.

Immune efficacy of a porcine circovirus type 2 vaccine purified using Gram-positive enhancer matrix surface display technology.

AIMS: Purification of porcine circovirus type 2 (PCV2) using Gram-positive enhancer matrix (GEM) surface display technology and immunogenicity evaluation of the purified antigen. METHODS AND RESULTS: A recombinant bifunctional protein containing a protein anchor domain and a 'virus anchor' domain was designed as a protein linker (PL) between PCV2 and GEM particles. By incubating with PL and GEM particles sequentially, PCV2 could be purified and enriched through a simple centrifugation process with GEM surface display technology. Our data showed that one unit (2·5 × 109 particles) of GEM particles with 80 µg PL could purify 100 ml of PCV2-containing culture supernatant (viral titre: 106·5 TCID50 per ml-1 ) with a recovery rate up to 99·6%. The impurity removal efficiency of this method, calculated according to decreased total protein content during purification, was approximately 98%. Furthermore, in vivo experimentation showed that piglets immunized with purified PCV2 could elicit strong immune responses to prevent against PCV2 infection. CONCLUSION: Porcine circovirus type 2 could be efficiently purified and enriched with GEM display technology via a crucial PL, and the purified PCV2 could elicit effective immune responses against PCV2 infection. SIGNIFICANCE AND IMPACT OF THE STUDY: The GEM-based purification method established here is cost-efficient and high-throughput, and may represent a promising large-scale purification method for PCV2 vaccine production.

Lithium chloride preconditioning optimizes skeletal myoblast functions for cellular cardiomyoplasty in vitro via glycogen synthase kinase-3beta/beta-catenin signaling.

The benefits of skeletal myoblast (SkM) transplantation for cardiomyoplasty are limited due to their decreased functional integration with host cardiomyocytes and the poor survival of implanted cells in ischemic hearts. However, little success has been achieved with respect to the strategies aiming to improve the efficiency of SkM transplantation. In this study, we demonstrated that LiCl-preconditioned SkMs resulted in significantly increased connexin 43 (Cx43) expression and gap-junctional communication with cardiomyocytes. Vascular endothelial growth factor (VEGF) expression of SkMs was significantly upregulated in response to LiCl. Furthermore, hydrogen peroxide induced SkM apoptosis and increased caspase-3 expression, whereas LiCl inhibited SkM apoptosis, resulted in the decrease of caspase-3 expression and promoted SkM proliferation. These effects of LiCl were mediated by inactivating glycogen synthase kinase-3beta (GSK-3beta), stabilizing the effector protein beta-catenin and translocating it into the nucleus of SkMs, confirming that LiCl mimics canonical Wnt signaling. These findings suggest that LiCl preconditioning may be a novel strategy to optimize SkM function for cellular cardiomyoplasty in vitro.

Protosappanin a, an immunosuppressive constituent from a Chinese herb, prolongs graft survival and attenuates acute rejection in rat heart allografts.

OBJECTIVE: Caesalpinia sappan L., which has been used in oriental medicine as an analgesic and antiinflammatory agent, has shown immunosuppressive activity on acute rejection on rat heart allografts. The present study was designed to investigate the potency of protosappanin A, one major ingredient of C. sappan L., in rat heart transplantation. MATERIALS AND METHODS: Protosappanin A isolated from an ethanol extract of C. sappan L. was identified by wave spectrum. All groups consisted of Wistar donors into Sprague-Dawley (SD) recipients, including large (25 mg/kg) or small (5 mg/kg) doses of protosappanin A plus cyclosporine (10 mg/kg). A control group was used. Animals were given the drugs on postoperative day 2. We observed graft survival and pathologic conditions of the hearts. Blood samples were obtained on postoperative day 7 to measure the CD4+/CD8+ T-cell ratio. Graft perforin and granzyme B mRNA expression levels were examined with reverse transcription-polymerase chain reaction (RT-PCR) methods. RESULTS: Protosappanin A or cyclosporine significantly prolonged heart allograft survival (P < .01), alleviated myocardial pathologic damages (P < .01), decreased the CD4+/CD8+ ratio (P < .05), and inhibited perforin and granzyme B mRNA expressions in the graft (P < .05). CONCLUSIONS: These findings demonstrated that protosappanin A prolonged heart allograft survival by significantly attenuating acute rejection.

Lithium chloride regulates connexin43 in skeletal myoblasts in vitro: possible involvement in Wnt/beta-catenin signaling.

Gap junction channels composed of connexin43 (Cx43) are essential for normal myogenic differentiation and skeletal muscle regeneration. Here, the aim was to study whether lithium chloride (LiCl) could regulate Cx43 expression and gap junction channel function by mimicking the Wnt/beta-catenin pathway in primary myoblasts. Cx43 mRNA expression in myoblasts was up-regulated in response to 5 mM LiCl. The enhanced Cx43 protein expression resulting from treatment with 5 and 10 mM LiCl for 24 h increased gap-junctional coupling in myoblasts. However, no obvious changes were observed with 20 mM LiCl. Furthermore, chronic treatment with 10 mM LiCl decreased Cx43 protein expression compared with untreated cells. The authors showed that LiCl mimicked the active canonical Wnt/beta-catenin signaling by glycogen synthase kinase-3beta (GSK-3beta) inactivation and accumulation of the effector protein beta-catenin into the nucleus. These results suggest that LiCl regulates Cx43 expression in skeletal myoblasts in vitro partly by a Wnt/beta-catenin-dependent pathway.

Comparison of four infectious bursal disease viruses isolated from different bird species.

Four isolates of infectious bursal disease virus (IBDV), isolated from chicken, duck, goose and sparrow in Jiangsu province of China in 2002, were compared. The viruses were stable to the treatments of 60 degrees C for 1 h, pH 2.0 and lipid solvents. Their antigenic relatedness values (R) were from 0.76 to 0.78. Chickens infected with the chicken isolate showed severe clinical symptoms of IBD and the mortality rate was 33.3% (2/6). Chickens infected with the other three viruses survived but their bursas were damaged and the bursa/body-weight ratios were lower than those of the uninfected control (p< 0.01). The titers of anti-IBDV antibody in infected chicken sera reached up to 1600 by virus neutralization and 6400 by ELISA at 10 days post infection. The sequences of the variable region of VP2 were aligned and compared, showing nucleotide variations ranging from 1.5 to 6.7% and deduced aminoacid variations from 0.8 to 2.2%. All had the same heptapeptide, S-W-S-A-S-G-S, Asp279, and Ala284. The four viruses clustered on a phylogenetic tree and were distant from the STC strain. These findings suggested that different bird species naturally infected with IBDV could serve as carriers or reservoirs in IBDV transmission and might play a role in the emergence of variant IBDV.

Variation in proton affinity of the guanidino group between free and blocked arginine.

In this paper, the analog of arginine residues in peptides was synthesized and characterized by ESI-MS/MS (electrospray ionization with tandem mass spectrometry), (31)P NMR, (1)H NMR, IR and high-resolution mass spectrometry. When the Todd reaction activity of the guanidino group in free arginine and the arginine peptide analog were compared, it was found that the proton affinity of the guanidino group was decreased when both the N- and the C-terminal were blocked. As a result, the guanidino group of arginine residues in peptides could be phosphorylated under the Todd reaction condition, but not the free arginine. This result was further proved by the theoretical calculation of their proton affinity.

Serotyping and antigenic comparison of some animal rotaviruses isolated in China.

Eight strains of rotaviruses isolated from diarrheal animals (4 from calves and 4 from piglets) in China were compared by serotyping with reference animal rotavirus strains (bovine NCDV, porcine OSU and simian SA-11 and human rotavirus Wa strain). Two-way cross neutralization test showed no antigenic difference between all 4 local strains of bovine rotavirus (BRV007, BRV014, HN-7 and BRV6555) and reference NCDV, so they belonged to rotavirus serotype 6 (bovine rotavirus serotype 1 or NCDV-serotype). Meanwhile, the four strains of Chinese porcine rotavirus could be determined into 2 different serotypes. One (Li99) was neutralised to a high titer with the antiserum against reference OSU virus and probably related to OSU (serotype 5 or porcine serotype 1). The other three strains (Lin71, Nan86 and Jiang150) were antigenically obviously different from Li99 and did not react with the antiserum against OSU. They were tentatively considered as porcine rotavirus serotype 2. All the strains of bovine and porcine rotavirus did not cross-neutralise with simian SA-11 and human Wa strain. There was also no antigenic relationship between bovine rotaviruses and porcine rotaviruses.