Chronic Disease ; Humans ; Tooth Diseases ; Tooth Injuries

OBJECTIVETo establish more rational three dimensional finite element model (FEM) of the first permanent mandibular molar and to study the internal stress distribution.

METHODSThe FEM was applied to analyze the stress distribution of the first permanent mandibular molar under various loading conditions.

RESULTSUnder all five loading conditions, the maximum von-Mises stress and compressive stress in enamel were larger than that in dentin, and the tensile stress in enamel was smaller than that in dentin. When vertical force and buccal-lingual oblique force were loaded, the stresses in the enamel and dentin were minimum; when lingual-buccal oblique force was loaded, the stresses were maximum; the stresses were mainly distributed at cervical region, furcation and apical area of the mesial-lingual root canal wall.

CONCLUSIONSThe stress value changes and stress distribution in the enamel and dentin were closely related with the direction of the occlusion force.

Adult ; Bite Force ; Dental Models ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; In Vitro Techniques ; Male ; Molar ; physiology

OBJECTIVETo study the effect of Chinese herbal compound (CHC) on the expression of hepatocyte cytochrome P450IIE1 in rat model of alcoholic fatty liver (AFL).

METHODSThe AFL rats models were established by administering the drinking water with 40%(v/v) ethanol, and the changes of pathology in liver and hepatocyte P450IIE1 expression, as well as the contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), vitamin E (VitE) in liver were detected and compared with those in the control group.

RESULTSFatty degeneration in liver recovered normally in the CHC-treated group. Immunohistochemical and in situ hybridization examination showed that CHC could inhibit the hepatocyte cytochrome P450IIE1 expression markedly, and restore the contents of MDA, SOD, GSH, VitE to nearly normal range.

CONCLUSIONCHC can prevent AFL through inhibiting the hepatocyte cytochrome P450IIE1 expression markedly

Animals ; Cytochrome P-450 CYP2E1 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Fatty Liver, Alcoholic ; pathology ; Gene Expression ; Hepatocytes ; drug effects ; enzymology ; Immunohistochemistry ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study regulation of Ca(2+)-activated K(+) channels (KCa) of mesenteric artery smooth muscle cell (SMC) from 21 old patients with essential hypertension (EH) by endothelin-1 (ET-1) and prostagl E(1) (PGE(1)).

METHODSMesenteric artery branch from EH was digested by enzyme. Patch clamp technique was used to pull cell-attached and inside-out patches on mesenteric artery SMC from EH and the normotensive patients respectively. The signal channel open probability (Po), open dwell-time (To) and close dwell-time (Tc), open channel number per patch were recorded. After adding Ca(2+) (10(-8) approximately 10(-6) mol/L), ET-1(2 approximately 8 x 10(9) mol/L) and PGE(1) (10, 20, 40, 100, 200, 400 nmol/L) to cytoplasm respectively. The parameters above were observed again.

RESULTSCompared to that of normotensive patients, the activities of KCa channels of patients with EH was higher. After adding Ca(2+) to cytoplasm,the Po of KCa channels in normotensive patients increased significantly. But it was few changes in EH group. KCa channels has dual reaction to ET-1 in normotensive patients. We have found no statistics difference when ET-1 present on KCa channels of EH cases. Whereas PGE(1) can affect KCa channels current and channels kinetic significantly in side-out patches. The Po of KCa channels increased. The To protracted and the Tc curtailed in EH.

CONCLUSIONSThe activities of KCa channels of patients with EH increased significantly. but the sensitive to Ca(2+) decreased. ET-1 were few effect to KCa channels. The PGE(1) can activated KCa channels of patients with EH.

Aged ; Alprostadil ; pharmacology ; Cells, Cultured ; Endothelin-1 ; pharmacology ; Female ; Humans ; Hypertension ; metabolism ; physiopathology ; In Vitro Techniques ; Male ; Mesenteric Arteries ; cytology ; Middle Aged ; Muscle, Smooth ; metabolism ; physiopathology ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; drug effects ; metabolism

Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Leukemia, Prolymphocytic, B-Cell ; diagnosis ; Male ; Middle Aged ; Retrospective Studies

OBJECTIVETo prepare a stable water-based magnetic fluid.

METHODSA water-based magnetic fluid was prepared by addition of polyvinylpyrrolidone (PVP) as the coating agent for the magnetic particles. After preparation of Fe3O4 by co-precipitation method, PVP was added for its coating, followed by ultrasonic agitation and purification.

RESULTSThe magnetic nanoparticles of homogeneously small size and water-based magnetic fluid were obtained, which had good dispersion in water with strong magnetism.

CONCLUSIONPVP can be used as a surfactant to stabilize the magnetic fluid.

Ferrous Compounds ; chemistry ; Magnetics ; Materials Testing ; Nanoparticles ; chemistry ; Povidone ; chemistry ; Surface Properties ; Surface-Active Agents ; chemical synthesis ; chemistry

OBJECTIVETo explore the impact of diabetic condition on the protective effect of diazoxide preconditioning (DPC) on ischemic-reperfused (I/R) myocardium in rats.

METHODSThirty normal male Sprague-Dawley rats were divided into 3 groups, including non-diabetic control group, non-diabetic I/R group, and non-diabetic I/R DPC group. Thirty diabetic male rats were also divided into the same 3 groups. The Langendorff isolated heart perfusion models were established. The control groups had a 90 min perfusion without any intervention. The I/R groups had a 30 min equilibration period, a 30 min ischemia, and a 30 min reperfusion. The I/R DPC groups had a 10 min equilibration, two cycles of 100 micromol/L diazoxide perfusion, 5 min each, followed by a 5 min diazoxide-free period before the 30 min ischemia and a 30 min reperfusion. The recovery rate of the left ventricular function, including cardiac output, left ventricular developed pressure (LVDP), and the maximum change rate of left ventricular pressure rise and fall (+/- dp/dt(max)) were recorded. The activity of creatine kinase in coronary outflow and activities of malonyldialdehyde, and superoxide dismutase in myocardium were detected. Myocardial water content was also assessed.

RESULTSIn non-diabetic rats, the content of creatine kinase, malonyldialdehyde and water content were significantly decreased in I/R DPC group compared with those in I/R group. Furthermore, in I/R DPC group, the activity of superoxide dismutase and the recovery rate of the left ventricular function, including cardiac output, LVDP and +/- dp/dt(max), were significantly increased compared with those in I/R group (P < 0.05). By contrast, there were no significant changes between I/R DPC group and I/R group in diabetic rats (P > 0.05).

CONCLUSIONDiabetes counteracts the protective effect of the diazoxide preconditioning on ischemic reperfused rat heart, which may be related with acute insulin resistance in cardiomyocytes.

Animals ; Diabetes Mellitus, Experimental ; Diazoxide ; pharmacology ; In Vitro Techniques ; Ischemic Preconditioning, Myocardial ; Male ; Myocardial Reperfusion Injury ; metabolism ; physiopathology ; prevention & control ; Myocardium ; metabolism ; Rats ; Rats, Sprague-Dawley ; Ventricular Function, Left

OBJECTIVETo investigate the feasibility, effectiveness and practicability of transurethral enucleation plus pneumocystostomy rotary cut (TUE + PCRC) for large benign prostatic hyperplasia (BPH).

METHODSWe performed TUE + PCRC for 26 BPH patients aged 62 - 85 years with the prostate volume of 80 - 165 ml. We conducted transurethral enucleation of the hyperplastic prostate glands and pushed them into the bladder, followed by bladder puncture for pneumo-cystostomy rotary cut.

RESULTSAll the surgical procedures were successfully accomplished, with the mean surgical time of 41 (32 - 54) minutes and intraoperative blood loss < 60 ml in all the cases. Twenty-three of the patients were followed up for 2 - 8 months, which revealed no stricture of the urethra or any other severe complications. Compared with the preoperative baseline, significant improvement was achieved in the IPSS (6.5 +/- 2.2 vs 26.2 +/- 2.4), QOL (1.4 +/- 0.9 vs 4.6 +/- 1.2) and Qmax ([5.8 +/- 1.0 ] vs [19.6 +/- 2.8] ml/s) of the patients after surgery (P < 0.01).

CONCLUSIONTUE + PCRC, with its advantages of short operation time and less severe complications, is a safe and effective approach to the management of large BPH.

Aged ; Aged, 80 and over ; Humans ; Male ; Middle Aged ; Prostatic Hyperplasia ; surgery ; Transurethral Resection of Prostate ; methods

OBJECTIVETo study the contents of organochlorine pesticides in human bodies and residues in serum of populations with non-occupational exposure as well as to study the relationship between organochlorine pesticides in foodstuff and residues levels in serum.

METHODSA cross-section study was conducted. 107 men and 142 women who were all healthy and living in the communities were investigated from Mar. 2004 to Jul. 2004. Level of daily food exposure was estimated through questionnaires while DDTs and HCHs serum levels were detected by EC-ECD. The relationship between organochlorine pesticides contents in foods and residues in serum were analyzed by ridge regression.

RESULTSFresh fish was positively correlated to men's serum level of beta-HCH and p,p'-DDT (beta = 0.1266 and beta = 0.0595) while vegetables and fruits were negatively correlated to women's serum level of beta-HCH (beta = -0.1066). Soybean was negatively correlated to women's serum level of p,p'-DDE and p,p'-DDT (beta = -0.0965 and 3 = -0.0581). Alcohol consumption was negatively correlated to men's serum level of beta-HCH and p,p'-DDE and women's serum level of p,p'-DDE (beta = -0.1315, beta = -0.1599 and P = -0.1128).Salted meat was negatively correlated to men's serum level of beta-HCH and p, p'-DDT (P = -0. 066 and P = - 0.0569).

CONCLUSIONIn this study, fresh fish might increase the body burden of organochlorine pesticides and residues while alcohol might promote the excretion of organochlorine pesticides. Pickled meat and vegetal foodstuff might contain low-level of organochlorine pesticides and residues.

China ; Diet ; Environmental Exposure ; Food Contamination ; Humans ; Hydrocarbons, Chlorinated ; blood ; Pesticide Residues ; blood ; Seafood ; Vegetables

Objective To investigate the change of the basic fibroblast growth factor(bFGF) leve in human detrusor muscle(DM)in bladder outlet obstruction(BOO)due to benign prostatic hyperplasia(BPH)and its implication.Methods Fifty-four patients with BPH were divided into two groups:the obstructive DM stability and instability groups;and 15 men with bladder tumor who underwent operation in the same period were enrolled in the control group.The bFGF mRNA level in DM was measured by reverse transcription and polymerase chain reaction(RT-PCR)and the bFGF protein level was measured by immunohistochemical staining method.Results The bFGF-mRNA expression level of bladder smooth muscle cells was significantly lower in the control group than that in the obstructive DM stability and instability groups(all P＜0.05),but there was no significant difference between the obstructive DM stability and instability groups(P＞0.05). Conclusions The expression level of bFGF mRNA in bladder DM is elevated in BOO due to BPH,but there is little or no correlation between the increased expression of bFGF mRNA and detrusor muscle instability.