Objective To inveatigate the effect of 15-HETE, a metabolite of arachidonic acid, on isolated hypoxic pulmonary arterial ringa ( PARs) , trying to find appropriate treatment for pulmonary hypertension and its complications during anesthesia in order to avoid hypoxemia. Methods Sixteen healthy Wistar rats of either sex weighing (230 ? 10) g were randomly divided into two groups : A control group breathing fresh air (FiO2 =21%) and B hypoxia group breathing hypoxic air (N2 = 90% , O2 = 10% ) in a hypoxic box. After breathing hypoxic air for 9 days the animals were anesthetized. Heart and lungs were immediately removed and PARs (0.5-1.0 mm in diameter and 3 mm in length) were prepared. Four PARs were prepared from each animal. The PARs were suspended in baths filled with Krebs-Hensleit (K-H) solution maintained at 37℃ and aerated with 95% O2 and 5% CO2. Preload was gradually increased to 0.3 g in 30 min. The isometric tension was measured using a four-channel force-displacement transducer. 15-HETE was added to K-H solution and the concentration was gradually increased from 10-8 to 10-6 mol?L-1 at 5 min intervals. Contractility of PARs was analyzed by a software of Medlab 6.0. Concentration-tension curve was drawn and contraction rates were calculated. 2 mmol?L-1 4-AP, 10-2 mol?L-1 TEA and 10-6 mol?L-1 GLYB were added to separate K-H solution baths and 40 min later 15-HETE was added in order to detennine the effect of difierent potassium channel blockers on contraction response of PARs to 15-HETE. Results With increasing concentration from 10-8 to 10-6 mol?L-1 , 15-HETE increased PARs tension gradually in a dose-dependent manner from 106% ?6% to 139% ? 4% in group A and from 113% ?6% to 163% ?6% in group B. The difference in PARs tension between group A and B was statistically significant (P

AIM: To study the effects of 1.5 MAC halothane and sevoflurane on ischemic myocardium. METHODS: The isolated rat heart were perfused with halothane and sevoflurane and HR, LVEDP, LVDP, +d p /d t , -d p /d t , coronary flow (CF), the myocardial ATP content and Ca 2+ -ATPase activity were determined before and 10 min and 25 min after ischemia. In the meantime, LVP was recorded during 25 min ischemia. RESULTS: 1.5MAC sevoflurane significantly increased CF in normal isolated rat hearts. Both halothane and sevoflurane depressed myocardial contractile function, increased normal myocardial energy storage. After 10 min ischemia, the decrease of myocardial ATP content were slowed down by halothane and sevoflurane, especially halothane. During 25 min of ischemia, the onset time of contracture was significantly delayed, and the contracture intensity was alleviated by halothane, but not sevoflurane. CONCLUSION: Halothane has better protective effect on ischemic myocardium than sevoflurane through preventing the decrease of myocardial ATP content and Ca 2+ -ATPase activity during ischemia.

OBJECTIVE: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. METHODS: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). RESULTS: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. CONCLUSIONS: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.
Animals ; Bone Resorption* ; Gene Expression ; Immunohistochemistry ; Models, Animal ; Osteoblasts* ; Osteoclasts* ; Rats ; Real-Time Polymerase Chain Reaction ; Receptors, Calcitonin ; RNA, Messenger ; Tooth Movement*

BACKGROUNDInsulin resistance (IR) plays an important pathophysiological role in the development of diabetes, dyslipidemia, hypertension, and cardiovascular disease. Moreover, IR can occur even in non-obese people without diabetes. However, direct detection of IR is complicated. In order to find a simple surrogate marker of IR early in non-obese people, we investigate the association of commonly-used biochemical markers (liver enzymes and lipid profiles) with IR in urban middle-aged and older non-obese Chinese without diabetes.

METHODSThis cross-sectional study included 1 987 subjects (1 473 women). Fasting blood samples were collected for measurement of glucose, insulin, liver enzymes, lipid profiles and creatinine. Subjects whose homeostasis model of assessment-IR (HOMA-IR) index values exceeded the 75th percentile (2.67 for women and 2.48 for men) of the population were considered to have IR. The area under the receiver operating characteristic curve (ROC) was used to compare the power of potential markers in identifying IR.

RESULTSTriglycerides (TG) and ratio of TG to high-density lipoprotein cholesterol (TG/HDL-C) discriminated IR better than other indexes for both sexes; areas under the receiver operating characteristic (ROC) curves (AUC) values were 0.770 (95% confidence interval 0.733-0.807) and 0.772 (0.736-0.809), respectively, for women and 0.754 (0.664-0.844) and 0.756 (0.672-0.840), respectively, for men. To identify IR, the optimal cut-offs for TG and TG/HDL-C ratio were 1.315 mmol/L (sensitivity 74.3%, specificity 71.0%) and 0.873 (sensitivity 70.1%, specificity 73.4%), respectively, for women, and 1.275 mmol/L (sensitivity 66.7%, specificity 74.4%) and 0.812 (sensitivity 75.8%, specificity 69.2%), respectively, for men.

CONCLUSIONTG and TG/HDL-C ratio could be used to identify IR in urban middle-aged and older non-obese Chinese without diabetes.

Aged ; Alanine Transaminase ; blood ; Aspartate Aminotransferases ; blood ; Cholesterol, HDL ; blood ; Cross-Sectional Studies ; Diabetes Mellitus ; blood ; Female ; Humans ; Insulin Resistance ; physiology ; Liver ; enzymology ; Male ; Middle Aged ; Triglycerides ; blood

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors