Objective To evaluate the effect of chronic low potassium on K+uptake rate in the my?ocardium and skeletal muscle of rabbits. Methods Thirty?two adult male rabbits, aged 12-14 weeks, weighing 2?0-2?7 kg, were randomly divided into 4 groups ( n=8 each) using a random number table:normal feeding group ( group N) , low potassium feeding group ( group L) , potassium supplementation con?trol group ( group SC ) and potassium supplementation experimental group ( group SE ) . N and SC groups were given a normal diet only, and L and SE groups were fed with a low potassium diet for 15 days. Potassi?um chloride ( KCl) 0?5 mol∕L was then infused intravenously at the initial rate of 60 μmol·kg-1 ·min-1 in SE and SC groups. Blood samples were obtained from the central artery of the left ear every 5 min for meas?urement of plasma K+ concentrations. The infusion rat of KCl was then adjusted until the plasma K+concen?tration reached 5?5 mmol∕L and maintained at this level for 1 h, and then infusion was stopped. The total volume of KCl infused was recorded. The hearts and soleus muscle of animals were excised for determination of K+content. K+uptake and uptake rate were calculated. Results Compared with N group, the plasma K+concentration, and K+content in the myocardium and soleus muscle were significantly decreased in group L ( P<0?05) . Compared with SC group, the total volume of KCl infused, and K+uptake and uptake rate in the myocardium and soleus muscle were significantly increased in group SE ( P<0?05) . Conclusion Chro?nic hypokalaemia can increase K+ uptake rate in the myocardium and skeletal muscle of rabbits.

BACKGROUND: Therapeutic methods for of peripheral facial nerve injury include surgery, physical therapy and drug treatment, but the treatment effect is not ideal in some certain cases. OBJECTIVE: To study the effect of autologous platelet rich plasma on repair of facial nerve injury. METHODS: The bilateral destroyed buccal nerve branches of the 10 white rabbits were put in silica gel nerve regeneration chamber, one side injected with platelet rich plasma as experimental group, the other side injected with normal saline as control group. The general observation, neuroelectrophysiology detection, histological observation, image analysis and evaluation of facial nerve regeneration recovery were performed at 8 weeks after surgery. RESULTS AND CONCLUSION: The action potential latency of the orbicularis oris at the experimental side was significantly lower than that at the control side, and the action potential amplitude (M wave) of compound nerve muscle of the experimental side was significantly higher than that of the control side (P < 0.01). Compared with the control side, the regenerative nerves of the experimental side were more mature with more regenerative axons, and the differentiation of myelin sheath was more mature and the thickness of myelin sheath was wel -distributed. Meanwhile, the diameters of axons were closed to the normal diameter, and the nerve axons were more intensive and arranged more regularly, the outer membrane of nerve fiber was thicker and the col agen fiber and elastic fiber layer were increased when compared with the control group. The number of regenerative axons of the control side was less, and the axons were distributed irregularly and poorly developed, and a large number of fibrous connective tissues were observed. The vacuolar degeneration at the control side was more than the experimental side. The regenerated nerve in the experimental side was better than the control side in the diameter of myelinated axon, area, myelin sheath thickness and axon count, and there were significant differences between two groups (P < 0.01). It indicates that platelet rich plasma has a promoting effect in the repair and regeneration of facial nerve.

AIM: To clarify the effects of gastrin on t he expression of cyclooxygenase (COX) and several growth factors in rat gastric mu cosa. METHODS: Male Sprague Dawley rats were fasted for 24 hours and s ubcutaneously injected with saline or gastrin 17 at doses of 1 ?g/kg, 10 ?g/kg and 100 ?g/kg, respectively. The expression of COX-1, COX-2, heparin-binding e p idermal growth factor-like growth factor (HB-EGF) and hepatocyte growth factor ( HGF) in the gastric mucosa were examined using Western blotting and immunohistoc hemical staining. Effects of a potent gastrin receptor antagonist YM022 on the e xpression of COX-1, COX-2, HB-EGF and HGF in gastric mucosa were also evaluated. RESULTS: Gastrin dose-dependently increased the expression of C OX-2 and HB-EGF in rat gastric mucosa while the expression of COX-1 and HGF did not change significantly after treatment with gastrin. However, pretreatment wit h YM022 dose-dependently abolished the up-regulation of COX-2 and HB-EGF express ion induced by gastrin. CONCLUSIONS: This study demonstrates that gastrin up-regulates C OX-2 and HB-EGF expression in rat gastric mucosa, indicating that COX-2 and HB-E GF are involved in pathogenesis of the gastrin-related gastric mucosal hyperplas ia and carcinoma of stomach.

AIM: To clarify the effects of specific and non-specific cyclooxygenase-2 (COX-2) inhibitors on gastric epithelial cell proliferating and gastric healing following acid-induced damage. METHODS: Male Sprague-Dawley rats were given 1 mL of 0.6 mol/L hydrochloric acid (HCl) into the stomach. Ten minutes after the administration of the acid,the animals were given NS-398 (COX-2 inhibitor) or indomethacin. Levels of COX-1 and COX-2 in the gastric mucosa before and after HCl-administration were analyzed using western blotting and immunohistochemical staining. Proliferating cell nuclear antigen (PCNA) was detected using immunohistochemistry for epithelial cell proliferation. Gastric lesion index (LI) was assessed using planimetry. RESULTS: Expression of COX-2 was enhanced mainly in surface epithelial cells and neck cells following HCl-administration. At 24 h following acid administration,PCNA labeling index (PCNA-LI) was (22.72?4.33) % and (21.98?5.18) % in the groups treated with 40 mg/kg of NS-398 and indomethacin respectively,which was significantly lower than that in the control group [ (34.46?3.61) %,P

Objective To explore the optimal experiment conditions of CCK-8 and MTS for cell proliferation assays in human amniotic epithelial cells and to evaluate the cytotoxicity of these reagents. Methods Human amniotic epithelial cells (hAECs) in logarithm growth stages were prepared in different cell concentrations with DMEM/F12 and 10% FBS. The sensitivity and optimal wavelengths was determined based on the optical density (OD) measured at 450 nm and 492 nm. The optimal time was determined under the conditions of the same cell concentration and defined OD values. HAECs were treated with DMSO, CCK-8 and MTS for 1 h, 2 h, 3 h, and 4 h, respectively. 24 h later, cytotoxicity of the CCK-8 and MTS was evaluated by determination of cell proliferation and Trypan Blue staining. Results The optimal detection wavelength was 450 nm for CCK-8, and 492 nm for MTS. The sensitivity of CCK-8 was slightly lower then that of MTS. The optimal time for incubation hAECs with CCK-8 was 4 h within 1~4 h. The inhibitory on cell proliferation and cytotoxicity of CCK-8 were weaker then those of MTS. Conclusion CCK-8 is a convenient reagent with low cytotoxicity for detection of the proliferation of hAECs.

Objective: To monitor the second-hand smoke (SHS) exposure in residents aged 15 years and over in public venues, indoor workplaces, on public transportation vehicles and at home in Beijing and evaluate the effect of Beijing Tobacco Control Regulation. Methods: Data from 2014 and 2016 Beijing Adult Tobacco Survey were used. The surveys covered 16 districts in Beijing. The study subjects were selected through multi-stage cluster sampling with probability proportional to population size, and data were collected by using electronic questionnaire in face-to-face household interviews. A total of 8 484 and 9 372 valid questionnaires were collected for the surveys in 2014 and 2016, respectively. Statistical packages SPSS 20.0 and R 3.4.4 were used for data analyses. After weighting the samples using complex survey designs, the SHS exposure rates in different places in adults of Beijing were estimated. χ² tests were performed for the comparison. Results: The SHS exposure rates of residents aged 15 years and over in Beijing who visited health care facilities, government buildings, universities, primary and secondary schools and restaurants declined from 12.8%, 19.7%, 24.3%, 32.8% and 65.7% in 2014 to 6.2%, 10.8%, 12.5%, 19.1% and 32.5% in 2016, respectively. The SHS exposure rates in bars/nightclubs were 89.5% in 2014 and 80.3% in 2016. From 2014 to 2016, the SHS exposure rates declined from 35.7% to 20.0% in indoor workplaces and declined from 3.9% to 2.5% on public transportation vehicles. The SHS exposure rates at home were 39.8% in 2014 and 37.6% in 2016, respectively. Conclusions The SHS exposure rates in public places declined obviously in Beijing after the one year implementation of Beijing Tobacco Control Regulation, indicating the effect of the regulation implementation.

OBJECTIVETo study transforming growth factor-beta1 (TGF-beta1) autoproduction in keloid fibroblasts and the regulation effect of blocking TGF-beta intracellular signaling on rhTGF-beta1 autoproduction.

METHODSKeloid fibroblasts cultured in vitro were treated with either rhTGF-beta1 (5 ng/ml) or recombinant adenovirus containing a truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects of regulating gene expression of TGF-beta1 and its receptor I and II were observed with Northern blot.

RESULTSrhTGF-beta1 up-regulated the gene expression of TGF-beta1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated the gene expression of TGF-beta1 and its receptor I, but not receptor II.

CONCLUSIONSTGF-beta1 autoproduction was observed in keloid fibroblasts. Over-expression of the truncated TGFbeta receptor II decreased TGF-beta1 autoproduction via blocking TGF-beta receptor signaling.

Activin Receptors, Type I ; biosynthesis ; pharmacology ; Cells, Cultured ; Down-Regulation ; Fibroblasts ; drug effects ; metabolism ; Gene Expression ; Humans ; Keloid ; metabolism ; Protein-Serine-Threonine Kinases ; RNA, Messenger ; genetics ; metabolism ; Receptors, Transforming Growth Factor beta ; biosynthesis ; metabolism ; Sensitivity and Specificity ; Signal Transduction ; Trans-Activators ; metabolism ; Up-Regulation