Aim To observe the effects of liver cirrho-sis on the expression of transforming growth factor-β1 ( TGF-β1 ) and ColⅠin rat myocardium and interven-tion of erythropoietin ( EPO ) . Methods Thirty-six male Sprague-Dasley rats were randomly divided into three groups:control group, liver cirrhosis group and EPO group, then the cardic hemodynamic parameters in vivo and levels of serum lactate dehydrogenase ( LDH ) as well as creatine kinase isoenzyme ( CK-MB) were measured. With Masson′s trichrome stain, changes of collagen formation of myocardial tissue in different groups were observed. Also the mRNA ex-pressions of TGF-β1 and ColⅠin myocardium were de-tected by RT-PCR. Results In contrast to control group, rats in liver cirrhosis group showed a decline in systolic and diastolic function of left ventricule, rising myocardial enzyme, a distinct increase of cardiac colla-gen deposition, as well as an elevation of TGF-β1 and ColⅠmRNA expressions. In contrast to liver cirrhosis group, rats in EPO group demonstrated an improve-ment in systolic and diastolic function of left ventricule as well as in cardiac collagen deposition, and a de-crease in both myocardial enzyme and TGF-β1 and ColⅠmRNA expressions. Conclusion Liver cirrhosis can lead to the changes of myocardial structure and function in rats,and it can accelerate myocardial inter-stitial fibrosis; EPO can protect the myocardial injury in liver cirrhosis rats.

OBJECTIVE: To explore the protective effects of hydrogen sulfide (H2S) on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanism.
 METHODS: Thirty male Sprague Dawley rats were randomly divided into a control group, a diabetes group and a treatment group (n=10 per group). Streptozotocin (i.p.) was utilized to establish a rat model of Type 1 diabetes mellitus (DM). The DM rats were treated with NaHS solution (i.p.). After 8 weeks, the diaphragmatic muscle contractility was assessed by isolated diaphragmatic strips experiments. The peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT) and maximal rates of contraction/relaxation (±dT/dtmax) were measured. The alterations of diaphragmtic ultrastructure were observed by electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and caspase-3 were analyzed by spectrophotometric method. The expressions levels of Bcl-2 and Bax mRNA in diaphragmatic muscle were detected by RT-PCR.
 RESULTS: Compared with the control group, in the diabetic group, the Pt, Po and ±dT/dtmax were significantly reduced (all P<0.01), while CT and 1/2RT were significantly increased (both P<0.01); ultrastructure in the diaphragmatic muscle were obviously changed; the content of MDA and the activity of caspase-3 were increased (both P<0.01), while the activity of SOD was decreased (P<0.01); the ratio of Bcl-2/Bax at mRNA level was decreased (P<0.01). Compared with the diabetes group, in the treatment group, the diaphragm contractility and ultrastructural damage were improved; the content of MDA and the activity of caspase-3 were decreased (P<0.05, P<0.01 respectively), while the activity of SOD was increased (P<0.01), the ratio of Bcl-2/Bax at mRNA level was also increased (P<0.01). 
 CONCLUSION The exogenous H2S can protect diaphragmatic muscle of Type 1 diabetic rats, which is related to reducing oxidative damage and suppressing cell apoptosis.
Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Diabetes Mellitus, Experimental ; Diaphragm ; drug effects ; Hydrogen Sulfide ; pharmacology ; Male ; Malondialdehyde ; metabolism ; Muscle Contraction ; drug effects ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Sulfides ; Superoxide Dismutase ; metabolism

The relatively independence and separation in the teaching of clinical medicine and basic medicine limits the ability training of students,and the combination of basic and clinic medicine in teaching has become the core issues and trends in medical teaching reform.So the conventional teaching patterns were reformed in pathophysiology by applying combination of basic and clinic medicine in teaching.In order to accelerate medical students to early exposure to clinical medicine Bengbu medical college changed the teachers' teaching ideas,promoted the local integration of the courses of basic and clinical medicine and the combination of basic and clinic medicine teachers in teaching,reformed mechanisms in teaching management and teaching operation.We also tested the preliminary reform effects by way of students' evaluation of the teaching and examination,and discussed the unfavorable factors affecting the educational reform and thought out some countermeasures.

In practice of forensic medicine, potential disease can be associated with fatal asphyxia in re-straint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and punc-ture (CLP) under the condition of restraint position. The results showed that in the CLP12-18 h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dtmax, -dT/dtmax, CT, Po, force over the full range of the force-frequency relationship and fatigue resistance ) declined progressive-ly; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

OBJECTIVETo investigate the molecular mechanisms of diaphragm injury in rats with liver cirrhosis.

METHODSThirty adult male Sprague-Dawley rats were randomized into control group (n=10) and carbon tetrachloride-induced liver cirrhosis group (LC group, n=20). In the 9th week, the rat body weight and diaphragm to body weight ratio were measured, and the parameters of diaphragm contractility including peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT), and force-frequency curve were assessed using a Medlab-U/4C biological signal collecting system. The activities of superoxide dismutase (SOD), succinic dehydrogenase (SDH) and myeloperoxidase (MPO) and malondiadehyde (MDA) content in the diaphragm were detected. The mRNA expression levels of sarcoplasmic reticulum calcium ATPase (SERCA) and cytoskeletal proteins (titin and nebulin) in the diaphragm were detected by RT-PCR, and the diaphragm ultrastructure was examined with electron microscopy.

RESULTSCompared with those in the control group, body weight, diaphragm to body weight ratio, Pt, Po, and tetanic force under the stimulus frequency of 10, 20, 40, 60, 100 Hz were all significantly decreased (P<0.01), while CT and 1/2RT were significantly prolonged in LC group (P<0.01). SOD and SDH activities were significantly lowered (P<0.01) while the contents of MDA and MPO activity were significantly increased in LC group (P<0.01) with significantly decreased SERCA, titin and nebulin mRNA expressions in the diaphragm (P<0.01). Electron microscopy of the diaphragm in LC group revealed myofibrillar degeneration, absence of the Z line, and mitochondria swelling and edema.

CONCLUSIONLiver cirrhosis increases free radicals and aggravates inflammatory response and lipid peroxidation in the diaphragm, thus leading to mitochondrial damages and decreased expressions of cytoskeletal proteins and SERCA to cause diaphragmatic dysfunction.

Animals ; Body Weight ; Carbon Tetrachloride ; Connectin ; metabolism ; Diaphragm ; metabolism ; Lipid Peroxidation ; Liver ; enzymology ; pathology ; Liver Cirrhosis ; metabolism ; Male ; Muscle Contraction ; Muscle Proteins ; metabolism ; Oxidation-Reduction ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism

OBJECTIVETo study the changes in diaphragmatic function and gene expressions of calcium regulatory proteins in diabetic rats and explore the mechanism of diaphragm dysfunction in diabetes mellitus.

METHODSSD rats were randomly divided into normal control group and diabetic (induced by intraperitoneal STZ injection) group. After 4 and 8 weeks, the body weight and diaphragm to body weight ratio were measured, and the activities of succinic dehydrogenase (SDH) in the diaphragm and blood glucose were assayed. The diaphragm contractility was assessed and the alterations of diaphragm ultrastructure were observed. RT-PCR was used to detect the changes in sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) and phospholamban (PLB) mRNA expressions in the diaphragm.

RESULTSThe diabetic rats showed a significant weight loss with a lowered diaphragm to body weight ratio (P<0.01) and SDH activity (P<0.01). The peak twitch tension and maximum tetanic tension of the diaphragm were significantly lowered and the time to peak contraction and half relaxation time significantly prolonged (P<0.01) in the diabetic rats, which also exhibited a lowered tetanic force in response to stimulus (P<0.01). Transmission electron microscopy revealed obvious ultrastructural changes of the diaphragm in diabetic rats. RT-PCR showed significantly decreased SERCA and increased PLB mRNA expressions in diabetic rat diaphragm (P<0.01), and these changes intensified with time (P<0.01).

CONCLUSIONDiabetes can cause impairment of diaphragmatic ultrastructure, mitochondrial injuries, and lowered SDH activity and ATP production. Decreased SERCA and increased PLB mRNA expressions in diabetes result in reduced Ca(2+) uptake by the diaphragm sarcoplasmic reticulum to induce diaphragm dysfunction.

Animals ; Body Weight ; Calcium ; metabolism ; Calcium-Binding Proteins ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; physiopathology ; Diaphragm ; metabolism ; physiopathology ; Glucose ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum ; metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism ; Succinate Dehydrogenase ; metabolism

Objective To investigate the molecular mechanisms of diaphragm injury in rats with liver cirrhosis. Methods Thirty adult male Sprague-Dawley rats were randomized into control group (n=10) and carbon tetrachloride-induced liver cirrhosis group (LC group, n=20). In the 9th week, the rat body weight and diaphragm to body weight ratio were measured, and the parameters of diaphragm contractility including peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT), and force-frequency curve were assessed using a Medlab-U/4C biological signal collecting system. The activities of superoxide dismutase (SOD), succinic dehydrogenase (SDH) and myeloperoxidase (MPO) and malondiadehyde (MDA) content in the diaphragm were detected. The mRNA expression levels of sarcoplasmic reticulum calcium ATPase (SERCA) and cytoskeletal proteins (titin and nebulin) in the diaphragm were detected by RT-PCR, and the diaphragm ultrastructure was examined with electron microscopy. Results Compared with those in the control group, body weight, diaphragm to body weight ratio, Pt, Po, and tetanic force under the stimulus frequency of 10, 20, 40, 60, 100 Hz were all significantly decreased (P<0.01), while CT and 1/2RT were significantly prolonged in LC group (P<0.01). SOD and SDH activities were significantly lowered (P<0.01) while the contents of MDA and MPO activity were significantly increased in LC group (P<0.01) with significantly decreased SERCA, titin and nebulin mRNA expressions in the diaphragm (P<0.01). Electron microscopy of the diaphragm in LC group revealed myofibrillar degeneration, absence of the Z line, and mitochondria swelling and edema. Conclusions Liver cirrhosis increases free radicals and aggravates inflammatory response and lipid peroxidation in the diaphragm, thus leading to mitochondrial damages and decreased expressions of cytoskeletal proteins and SERCA to cause diaphragmatic dysfunction.

Objective To investigate the molecular mechanisms of diaphragm injury in rats with liver cirrhosis. Methods Thirty adult male Sprague-Dawley rats were randomized into control group (n=10) and carbon tetrachloride-induced liver cirrhosis group (LC group, n=20). In the 9th week, the rat body weight and diaphragm to body weight ratio were measured, and the parameters of diaphragm contractility including peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT), and force-frequency curve were assessed using a Medlab-U/4C biological signal collecting system. The activities of superoxide dismutase (SOD), succinic dehydrogenase (SDH) and myeloperoxidase (MPO) and malondiadehyde (MDA) content in the diaphragm were detected. The mRNA expression levels of sarcoplasmic reticulum calcium ATPase (SERCA) and cytoskeletal proteins (titin and nebulin) in the diaphragm were detected by RT-PCR, and the diaphragm ultrastructure was examined with electron microscopy. Results Compared with those in the control group, body weight, diaphragm to body weight ratio, Pt, Po, and tetanic force under the stimulus frequency of 10, 20, 40, 60, 100 Hz were all significantly decreased (P<0.01), while CT and 1/2RT were significantly prolonged in LC group (P<0.01). SOD and SDH activities were significantly lowered (P<0.01) while the contents of MDA and MPO activity were significantly increased in LC group (P<0.01) with significantly decreased SERCA, titin and nebulin mRNA expressions in the diaphragm (P<0.01). Electron microscopy of the diaphragm in LC group revealed myofibrillar degeneration, absence of the Z line, and mitochondria swelling and edema. Conclusions Liver cirrhosis increases free radicals and aggravates inflammatory response and lipid peroxidation in the diaphragm, thus leading to mitochondrial damages and decreased expressions of cytoskeletal proteins and SERCA to cause diaphragmatic dysfunction.

OBJECTIVE: To observe the protective effect of soybean isoflavones (SI) on the heart function of the rats with adriamycin induced heart failure. METHODS: Thirty adult male SD rats were divided into 5 groups:normal control (NC) group, adriamycin (ADR) group, L-SI group, M-SI group and H-SI group. SI of 30, 60, 120 mg.kg(-1).d(-1) was orally administered through a stomach tube once a day for 6 days in L-SI group, M-SI group and H-SI group, respectively. The other two groups were given the same amount of normal saline the same way. Then ADR of 10 mg/kg was given intraperitoneally once to copy the model of heart-failure. The MedLab-U/4c biological signal collecting system was used to record and analyze the LVSP of the rats. The pathological changes of the cardiomyocytes were observed. RESULTS: As compared with NC group, the LVSP,+/-dp/dt max, Vpm of the ADR group were significantly lower (P<0.05 or P<0.01), but those of the H-SI group were markedly higher than those of the ADR group (P<0.01). Electron microscopic morphometry of the heart samples of the rats in ADR group revealed typical alterations, consisting an increase of collagen content, vacuolation, diminishing of the cardiomyocyte diameter, alteration of myofilaments and Z-lines of myofibers, and myofibrillar degeneration. SI of 120 mg.kg(-1).d(-1) treatment could prevent the loss of myofibrillae and the reduction of myocyte diameter, and the degeneration of myofilaments and Z-lines were reversed by SI. CONCLUSION: SI of 120 mg.kg(-1).d(-1) treatment can relieve the toxic effect of ADR on myocardium, and also obviously improve the cardiac contractility of heart-failure rats.

An experimental study of two approaches of teaching——problem-based learning(PBL) combined with lecture-based learning(LBL) and LBL only——was conducted respectively in two classes of 2003 college students.It was proved that PBL combined with LBL has an obvious advantage over LBL only(P