Fiber type of skeletal muscle and its multiple and specialized protein isoform are the structure and molecular basis of the skeletal muscle's function and adaptability.Myosin heavy chain(MHC)isoform,as the factor determinating the type of the skeletal muscle to be fast or slow one,has become molecular biomarker of muscle fiber type and adaptability.Exercise may lead to the transform between myosin subtypes.This article reviewed not only the relation between myosin heavy chain and muscle fiber type of skeletal muscle,but also the influences of different motor patterns' on the transform of skeletal muscle fiber MHC isoform.

BACKGROUND:Heavy load exercises can induce the ultrastructural changes in the skeletal muscle by the depolymerization and/or degradation of tubulin in the skeletal muscle, thereby lessening contraction activities of the skeletal muscle. OBJECTIVE:To observe the effects of heavy load exercise and acupuncture on tubulin levels, and to analyze their roles and mechanisms in skeletal muscle injury and repair. METHODS:138 male Sprague-Dawley rats aged 8 weeks were randomly divided into acute exercise group (n=114) and long-term exercise group (n=24). The acute exercise group included four subgroups:sedentary group (n=6), exercise group (n=36), acupunctured group (n=36) and exercise plus acupuncture group (n=36). In the acute exercise experiment, rats were acupunctured after a medium-large intensity downhil running. Rat’s soleus samples were taken immediately, 6, 12, 24, 48 and 72 hours after exercise and/or acupuncture. In the long-term exercise experiment, rats underwent exercise and acupuncture for 3 weeks, and rat’s soleus samples were col ected at 24 hours after the last training. Expressions ofα-tubulin and microtubule-associated protein 4 (MAP4) in the soleus were detected by western blot assay. RESULTS AND CONCLUSION:After acute exercise, expression ofα-tubulin and MAP4 was up-or down-regulated transiently. After acute exercise combined with acupuncture, the protein expressions ofα-tubulin and MAP4 changed slightly. However, the long-term exercise induced an increase inα-tubulin protein expression, while a significant decrease in MAP4 protein expression. It was worth noting that acupuncture treatment reduced long-term exercise-induced variations of MAP4 expression. These results suggest that the heavy load exercise can induce the depolymerization of tubulins in the skeletal muscle, and acupuncture may relieve this effect.

Aim To set up a novel animal model of intra-abdominal adhesion and to determine whether the tissue plasminogen activator activity (PAA) in exudate can be taken as an indicator to judge the formation of the adhesion. Methods　Rats were randomly divided into 2 groups. Each animal in both groups was opened the abdominal cavity via midline laparotomy without any disinfectant measures. 2-cm section from the cecal end was clamped and ligated, 1-cm cecum of the section was cut, and another 1-cm end from the ligated site was kept. After the content in the end was extruded, the cecum was put back without using any antibacterial agent. Before the skin closure, an effective combination AMD (allantoin, metronidazole and dexamethasone in combination), was given (ip) according to 1.5 ml per 100 g body weight (60.6 mg·kg-1). The control group was injected (ip) the same volume of normal saline. After 6 h, the exudate was extracted from drainage-tube, with the rats varying posture, and after 1 kw, the rats were killed for examining the intra-abdominal adhesion. The values of PAA of exudate in both groups were analyzed by the relative operating characteristic curve (ROC). Results　In the control group, all 20 rats formed the adhesions, the amount of exudate=(1.25±0.09) ml, the number of WBC(×103)=(23.1±6.6) mm3 and PAA=(0.9±0.4) IU·ml-1 in the exudate of abdominal cavity. In AMD group, however, there was not the adhesion formations (0/20), the amount of exuade was (0.52±0.04) ml (P<0.01), the number of WBC (×103) (10.6±4.2) mm3 (P<0.01), and PAA (23.1±6.6) IU·ml-1(P<0.01) in exuade.ROC analysis indicated that if PAA >1.24 IU·ml-1 in the exuade, the adhesion was difficult to form, and vice versa. Conclusion　This animal model can be taken as an effective tool to evaluate the human adhesion related to multi-links on the pathogenesis, and the PAA in exudate an indicator to judge intra-abdominal adhesion formation.

Alzheimer's disease(AD)and Parkinson's disease(PD)are common neurodegenerative diseases that seriously threaten the health of the elderly, involving various abnormalities in physiology and metabolism including the impairment of mitochondrial function, Ca 2+ homeostasis deregulation, oxidative stress, aggregation of misfolded proteins, autophagy and inflammation.However, mechanisms underlying the pathogenesis of these diseases have not been clearly elucidated, thus impeding advances in their treatment.In recent years, it has been found that mitochondria-associated endoplasmic reticulum membranes(MAM)play an important role in the development of AD and PD and exert their effects by regulating the functions of mitochondria and endoplasmic reticula.This article reviews studies of the past decade related to the effects of MAM on AD and PD, aiming to generate insights for exploring the constituent proteins of MAM and the molecular mechanisms of AD and PD via endoplasmic reticulum-mitochondria Ca 2+ transport and ER stress regulated by MAM.

Lamin A,which is an important skeleton protein in the cell nucleus,can play an important role in maintaining the morphological structures of the cells.This article summarizes the location of LMNA gene in the chromosome,the shape and the structum of lamin A protein;the different diseases of the body which result from the mutations and deletions of LMNA gene in different sites;the differentiation functions of myoblast in which lamin A is involved:degradation of lamin A that may be promoted by Caspase-6;theexpression of lamin Athatmay bepromoted by NFAT5.

Objective To explore the effects of an acute exercise on the contractile protein degradation and 26S proteasome activity in skeletal muscle.Methods Thirty-six male Sprague-Dawley rats were randomly divided into 6 groups,each group consisted of 6 rats.They were killed respectively at rest,immediately after half an hour of exercise(running on the treadmill at 25m/min,5% grade),and 1 hour,2h and 6h after one hour exercise.The 3-methylhistidine(3-MH)content,26S proteasome activity and C2 subunit mRNA expression in rat gastrocnemius muscle were detected.Resuits(1)3-MH content increased immediately and 6 hours after exercise,and reached its peak level immediately after half an hour of exercise(P<0.01).(2)26S proteasome activity increased immediately after half an hour of exercise and 6 hours after exercise(P<0.05).(3)Expression of 26S proteasome C2 subunit mRNA Was lower than baseline during and after exercise,but increased sharply 6 hours after exercise(P<0.01).Conclusion The increase in 26S proteasome activity regulated by subunits gene after exercise could enhance skeletal muscle contractile protein degradation

Objective] To investigate the clinical features of amebic liver abscess, the causes of misdignosis and the effect of medical and surgical therapy on patient′s prognosis. [Methods] The clinical features of 36 patients with amebic liver abscess admitted from 1982 to 1997 in our hospital were retrospectively reviewed. [Results] The major clinical manifestations were: abdominal pain (86 1%), fever (86 1%),hepatomegaly with tenderness (83 3%) and right intercostal tenderness(58 3%). Leukocytosis was observed in 61 1%, and increased of ESR in 88 5% (23/28). Serologies against Entamoeba histolytica were noted in 92 6%. Ultrasonography showed single lesions in 75% and right\|lobe involvement in 75%. All patients were treated with metronidazole and 27 patients received treatment with needle aspiration or draining at the same time. After treatment, 10 patients were cured, 25 patients were improved significantly and effective rate was 97 2%. One patient died of hepatic failure. [Conclusion] Medical therapy alone was excellent for small abscesses, while percutaneous needle aspiration or draining was a successful approach in patients with large abscesses.

BACKGROUND: High-intensity exercise can induce the depolymerization and/or degradation of tubulin in the skeletal muscle. According to the close relation with the mitochondria, tubulin may influence mitochondrial movement track and molecular motor, thereby varying the movement and distribution of mitochondria. OBJECTIVE: To observe the effect of high-intensity exercise on α-tubulin, MAP4, Miro1 and mitochondrial ultrastructures, analyze their sequential changes and further explore whether tubular depolymerization regulates the movement and distribution of mitochondria via Miro1. METHODS: Fifty-six Sprague-Dawley rats were divided into control (n=8) and exercise (n=48) groups. The rats in the exercise group ran on the treadmill ( -16°, 20 m/minute) for 90 minutes, and the soleus samples were removed immediately, 6, 12, 24, 48 and 72 hours after exercise (n=8 each time point). The expression levels of α-tubulin, MAP4 and Miro1 were detected by western blot assay, and the ultrastructural changes of mitochondria were observed under transmission electron microscope. RESULTS AND CONCLUSION: The expression level of α-tubulin was decreased significantly at 6 and 12 hours after exercise. The expression level of MAP4 was increased significantly at 6, 12, 48 and 72 hours after exercise. The expression level of Miro1 was increased firstly at 6 and 12 hours after exercise, and decreased at 72 hours after exercise. In the control group, the paired mitochondria were arranged on the both sides of Z line, and few appeared in the myolemma. Mitochondria began to accumulate in the myolemma immediately and 6 hours after exercise; the number achieved the peak at 12 hours, reduced at 24 and 48 hours, and returned to normal at 72 hours. These results suggest that high-intensity exercise can induce the depolymerization of microtubules in the skeletal muscle, thus regulating the movement and distribution of mitochondria via Miro1.

Objective To investigate the clinical characteristics of tuberculosis (TB) first presenting as fever of unknown origin (FUO). Methods The clinical data of 100 cases of FUO, diagnosed as TB finally, among in-patients in Peking Union Medical College Hospital were analyzed retrospectively.Results ( 1 ) Sites of TB: there were 39 patients with merely pulmonary TB, 28 patients with merely extrapulmonary TB, and 33 patients with both pulmonary and extrapulmonary TB. (2) Clinical manifestations: depending on the different sites of tuberculous lesion, the clinical symptoms varied accordingly. The common laboratory findings included anemia, hypoalbuminemia, elevation of the level of ESR and C-reactive protein (CRP). (3) Methods for diagnosis: 34 cases were diagnosed by sputum smearor cultivation-positive for acid-fast bacilli; 8 cases by histopathology; 49 cases by clinical diagnosis of TB with an effective anti-TB therapy; and 9 cases by effective diagnostic anti-TB therapy. (4) Responses to treatment: among 73 cases with complete follow-up data, only 2 cases (2. 7% ) died and the other cases were cured or alleviated. Fifty-five cases (77.5%) showed marked efficacy after less than 4 weeks of regular anti-TB therapy, 37 cases ( 52. 1% ) suffered adverse effects of anti-TB agents, and all of them had improved after modifying anti-TB therapy and supporting treatment. Conclusions The diagnosis of TB that presents as FUO is quite difficult, and the median interval time for making diagnosis is 14 weeks (3-77weeks). Investigating clinical manifestations comprehensively, reviewing radiology data carefully, and eliciting microbiological and pathologic evidence of TB, are extremely important for making the correct diagnosis. In some cases, a therapeatic trial of anti-TB therapy is necessary.

Objective To report the clinical characteristics of prosthetic valve endocarditis (PVE).Methods All 25 cases of definite PVE (Duke criteria) diagnosed at our hospital between January 1992 to December 2008 were retrospectively analyzed. Among them, 7 cases were pathologically confirmed and the others were clinically confirmed with either 2 major criteria or 1 major and ≥3 minor criteria. Their clinical characteristics, underlying heart diseases, previous heart operations, presenting manifestations, causative microbes, echocardiographic findings and prognosis, were studied. Results (1) Although most cases underwent valve transplantations for underlying heart diseases of rheumatic heart diseases and congenital heart diseases, 10 patients were complicated with infectious endocarditis (IE) prior to the operations, 4 of them were PVE. (2) Eleven of them developed PVE within 2 months postoperatively. Fever (100%),major vessel embolism (48%), and anemia (36%) were the most frequently manifestations. Fourteen cases (56%) had positive culture results with 15 causative pathogens, including 5 coagulase-negative Staphylococcus (CNS, 3 were methicillin-resistant coagulase-negative Staphylococcus, MRSCoN), 4 fungi, 2Enterococcus faecalis, 2 Burkholderia cepacia, 1 Stenotrophomonasmal-tophilia, and 1 Streptococcus.(3)Prosthetic valve vegetations, periannular leakage, regurgitation, were the main echocardiographic findings.Transesophageal echocardiography (TEE) revealed 13 PVE who had no positive findings on previous transthoracic echocardiography (TTE). (4) Eighteen PVE (72%) developed peri-annular complications (12 leakage, 3 dehiscence, 2 abscesses, 1 fistula), major vessel embolism, congestive heart failure (16%) were frequently observed, 9 of the 17 patients died in hospital, in spite of intensive managements.Conclusions PVE has a high mortality and is a severe complication for patients who underwent heart surgery. Its causative pathogen spectrum is quite different from that of native valve endocarditis. TTE is not sensitive for some PVE cases.