[Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing].

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

[Predictive value of quantitative dynamic contrast-enhanced magnetic resonance imaging for the efficacy of neoadjuvant chemotherapy in locally advanced gastric cancer].

Objective: To investigate the predictive value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters for the efficacy of neoadjuvant chemotherapy in locally advanced gastric cancer. Methods: Sixty-five patients with locally advanced gastric cancer (LAGC) confirmed by gastroscopy and received neoadjuvant chemotherapy (NCT) were enrolled in this study. Quantitative DCE-MRI was performed before NCT, and the quantitative parameters were measured, including volume transfer constant (K(trans)), rate constant (K(ep)), volume fraction of extravascular extracellular space (V(e)) and volume fraction of plasma (V(p)). After NCT, all patients received radical gastrectomy. According to postoperative pathological tumor regression grade, patients were divided into response group and non-response group, and the differences of DCE quantitative parameters between the two groups were compared. ROC curve was utilized to analyze the predictive efficacy of DCE quantitative parameters for NCT response of LAGC, and multivariate logistic regression analysis was performed to analyze the predictive efficacy of combined parameters. Results: Thirty-seven patients were in response group and 28 patients were in non-response group. The pretreatment K(trans) in the response group were [0.216 min(-1) (0.130 min(-1), 0.252 min(-1))], significantly higher than [0.091 min(-1) (0.069 min(-1), 0.146 min(-1))] of non-response group (P<0.001), and V(e) in the response group were [0.354(0.228, 0.463)], significantly higher than [0.200(0.177, 0.253)]of non-response group (P<0.001). ROC analysis showed the AUCS of K(trans) and V(e) in predicting NCT efficacy were 0.881 and 0.756, respectively. Multiple logistic regression analysis showed that the combination of the two parameters could improve the AUC to 0.921, with the sensitivity and specificity of 86.5% and 89.3%, respectively. Conclusion: DCE-MRI quantitative parameters could help to predict the NCT response of LAGC, and the combination of parameters could improve the predictive efficacy.

Potential immunomodulatory effects of stem cells from the apical papilla on Treg conversion in tissue regeneration for regenerative endodontic treatment.

AIM: To evaluate the expression of Foxp3-positive lymphocytes around newly formed tissue after regenerative endodontic treatment (RET) in vivo and investigate the effects of stem cells from the apical papilla (SCAP) on the conversion of CD4+ CD25- T cells to CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in vitro. METHODOLOGY: Three 6-month-old beagles with nine doubled-rooted premolars in each dog were randomly assigned to the RET group and the control group. RET was performed after apical periodontitis had been induced in the experimental immature teeth. Three months later, the expression of Foxp3 was detected in the histological sections by immunofluorescent staining. Human SCAP and CD4+ CD25- T cells from mice spleens (1 : 1 and 1 : 5) were co-cultured in cell-cell contact or in Transwells, respectively, for 24 and 72 h in vitro. The percentage of Tregs was evaluated by flow cytometry. The results were analysed using the Fisher's exact test and analysis of variance. P < 0.05 was regarded as statistically significant. RESULTS: Inflammatory cells were present with tissue regeneration in the RET group, and Foxp3-positive T cells were enriched around the newly formed tissues. SCAP promoted Treg conversion after 72 h in vitro. Cell-cell contact played an important role after the 24 h co-culture, whilst soluble factors were also involved after 72 h (P < 0.05). CONCLUSIONS: SCAP promoted the conversion of pro-inflammatory T cells to Tregs in vitro. Tregs were enriched around the regenerating tissues in the root canals after RET, which may create a suitable immune microenvironment for the differentiation of SCAP. This study provides an underlying mechanism for tissue regeneration during RET.

iRoot FM exerts an antibacterial effect on Porphyromonas endodontalis and improves the properties of stem cells from the apical papilla.

AIM: To investigate the antibacterial activity of a novel intracanal medicament, iRoot FM, against Porphyromonas endodontalis and its effects on the proliferation and osteo-/odontogenic differentiation of stem cells from apical papilla (SCAP). METHODOLOGY: The agar diffusion test was used to compare the antimicrobial efficacy of iRoot FM with two traditional intracanal medicaments, calcium hydroxide [Ca(OH)2 ] and triple antibiotic paste (TAP). The CCK-8 assay was used to assess the proliferation rate of SCAP when exposed to the three intracanal medicaments. The expression levels of ALP and DMP-1 and the capacity to form mineralized nodules were used to evaluate the osteo-/odontogenic differentiation of SCAP, as assessed by real-time PCR, Western blotting and alizarin red S staining. Data were statistically analysed with one-way analysis of variance (anova), and comparisons between each of two groups were analysed by the least significance difference method. P values less than 0.05 were considered statistically significant. RESULTS: The zone of inhibition against P. endodontalis produced by iRoot FM was 20.74 ± 4.35 mm, whilst the zones of inhibition of Ca(OH)2 and TAP were 24.89 ± 3.84 mm and 34.51 ± 1.20 mm. The antibacterial capacity of iRoot FM was similar to that of Ca(OH)2 (P > 0.05). SCAP, cultured in conditioned medium with iRoot FM, was associated with greater proliferation and osteo-/odontogenic differentiation capacity than those cultured in conditioned medium with Ca(OH)2 and TAP (P < 0.05). Moreover, iRoot FM had no negative effects on the proliferation rate of SCAP. CONCLUSIONS: iRoot FM exhibited excellent antibacterial activity against P. endodontalis and could improve the proliferation and differentiation of SCAP. The findings provide evidence that iRoot FM has potential as an intracanal medicament for endodontic procedures in immature permanent teeth.

[Intramural gastric metastasis of esophageal squamous cell carcinoma: an analysis of imaging findings and clinicopathological features].

Objective: To discuss the imaging findings and clinicopathological features of the intramural gastric metastasis (IGM) of esophageal squamous cell carcinoma. Methods: The imaging findings of 11 patients with IGM confirmed by surgical pathology were reviewed retrospectively, and compared with clinicopathological features. Of the 11 cases, eight underwent upper gastrointestinal radiography, ten underwent contrast enhanced computed tomography (CT) scans and one underwent plain CT scanning. Results: In all 11 cases, the primary cancer was located in the middle or lower thoracic esophagus, and nine of 11 had lymph nodes metastasis. All of the 11 tumors within the stomach were located in the upper one-third of the stomach, with the maximum diameter of tumor ranging from 1.0 cm to 12.0 cm. Gastrointestinal radiography showed irregular filling defect of the stomach in three cases with clear border resembled a submucosal tumor. Mucosal folds of the stomach were irregular and rough in two cases. On CT scans, nodule or mass in the gastric wall was found in seven patients, and two of them were accompanied with ulcer formation. Eccentric or nodular gastric wall thickening was found in the other two patients. All of them were heterogeneous mild-to-moderate enhancement. Conclusions: The imaging appearances of IGM have certain characteristics, but final diagnosis depends on histopathology. The prognosis of IGM was extremely poor, so the preoperative diagnosis is very important to guide clinical treatment.

Comparison of in vivo dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate.

AIM: To compare dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate (MTA) in dogs. METHODOLOGY: Pulps in 36 incisors of three 8-month-old beagle dogs were mechanically exposed and assigned to two experimental groups (iRoot BP Plus group and MTA group, n = 15 per group) and one control group (n = 6). Direct pulp capping was performed using either iRoot BP Plus or MTA. The animals were sacrificed 3 months later. Histological sections were stained with haematoxylin and eosin and categorized using a histologic scoring system. Statistical analysis was performed using the Mann-Whitney U-test, with the significance set at 0.05. RESULTS: The majority of specimens in both experimental groups were associated with complete calcified bridge formation and the absence of pulpal inflammation. There was no significant difference in pulp response to iRoot BP Plus or MTA after 3 months (P > 0.05). CONCLUSION: iRoot BP Plus and MTA had similar favourable results when used as pulp-capping agents.

Full-length sequence and expression analysis of a myeloid differentiation factor 88 (MyD88) in half-smooth tongue sole Cynoglossus semilaevis.

Myeloid differentiation factor 88 (MyD88) is a universal and crucial adaptor protein, which plays an essential role in the intracellular signalling elicited by IL-1R/TLR superfamily. In the present study, we report the full-length sequence of MyD88 gene in half-smooth tongue sole (Cynoglossus semilaevis). In the 2855 bp genomic sequence, five exons and four introns were identified. The cloned cDNA exhibited 110 bp of 5' UTR, 576 bp of 3' UTR and 858 bp of the entire open-reading frame encoding a polypeptide of 285 amino acids. The protein sequence included a typical conserved cytosolic Toll/interleukin-1 receptor (TIR) domain, an intermediate domain (ID) and a death domain (DD), and shared greater than 70% identity with Japanese flounder Paralichthys olivaceu ortholog. Real-time polymerase chain reaction (RT-PCR) analysis indicated a broad expression of csMyD88, especially in ovary and spleen. Quantitative RT-PCR analysis indicated that the csMyD88 mRNA levels were significantly increased in the spleen and head kidney after inactive Vibrio anguillarum challenge and the expression of csMyD88 appeared to be developmentally regulated during C. semilaevis ontogeny. Although, species-specific differences were present, the similarity between mammalian and piscine MyD88s suggested that the main function of MyD88 might be conserved across vertebrates.

[The significance of sIL-2R detection in various hepatic diseases].

To study the alteration of the level of sIL-2R in acute and chronic hepatic diseases and its relation between alteration and the extent of damage to liver, the level of sIL-2R with hepatic disease was measured by a monoclonal and polyclonal Antibody ELISA. The result showed that the level increased differently in various hepatic diseases. The level of sIL-2R decreased when turning into severe hepatitis, acute hepatitis, active cirrhosis, chronic active hepatitis, hepatocarcinoma, compensative cirrhosis, chronic persistent hepatitis. It was suggested that the level of sIL-2R be considered of clinical value to estimate the extent of damage to liver in patients with progressive liver damage.

Prehispanolone, a novel platelet activating factor receptor antagonist from Leonurus heterophyllus.

1. Using an in vitro radioligand binding assay for the platelet activating factor (PAF) receptor, we have identified a novel, specific PAF antagonist, prehispanolone, from a Chinese medicinal herb Leonurus heterophyllus. 2. The presence of sodium ions inhibited specific [3H]-PAF binding to rabbit platelet membrane with an IC50 of 5.2 mM, decreased the inhibitory potency of PAF but increased the inhibitory potency of prehispanolone. 3. Prehispanolone and several of its derivatives inhibited the binding of [3H]-PAF to rabbit platelets with potencies closely resembling that of inhibition of PAF-induced aggregation. 4. The integrity of the tetrahydrofuran ring of prehispanolone is critical for its interaction with the PAF receptor. 5. By hydrogenating the dihydrofuran ring and replacing the keto group of prehispanolone with a hydroxyl group, we obtained a compound, LC5507, that is more stable and more active than prehispanolone as a PAF receptor antagonist.

[Effects of rifamdin on pharmacokinetics of dexamethasone].

The rabbits of same sex and approximate weight, were randomly divided into following two groups: a group given all rifamdin for 12 days before dexamethasone injection and a control group without RFD. After a single IV injection of dexamethasone sodium phosphate, the concentrations of dexamethasone in rabbit plasma taken at 5, 15, 30 min, and 1, 2, 4, 8 h were analysed by reversed phase HPLC-UV. Linear regression analysis was made by LnC(t)-t. The pharmacokinetic parameters of dexamethasone in rabbits were calculated by methods of residuals. The results of main parameters, i.e. K10, beta, T1/2 beta, cls and AUD0-infinity kg-1 showed that rifamdin apparently promotes metabolic clearance of dexamethasone in plasma.