OBJECTIVETo observe Smads protein expression in lung tissue of quartz exposed mice and to explore its association with pulmonary fibrosis in silicosis.

METHODSThe experimental mice were divided into control and quartz groups. 0.2 g/kg weight of quartz was injected intratracheally in quartz group. Samples were collected at the 1st, 3rd, 5th, 7th, 14th and 28th day after injection. Immunohistochemical methods with quantitative image analysis were used to assay the protein expression of transforming growth factor beta(1) (TGF-beta(1)), Smad 2/3, Smad 4, and Smad 7 protein levels. Protein expression level is presented by positive unit (PU).

RESULTSSmad 2/3 protein expression increased from day 3, reaching its peak level in day 14 [(42.2 +/- 2.4) PU], and decreased gradually. The elevation of Smad 4 protein level began from day 5, and the highest degree came into day 14 [(40.0 +/- 1.8) PU], decreased thereafter. The expression of Smad 7 presented a decreasing tendency at the beginning and reaching the lowest level in day 14 [(33.5 +/- 3.3) PU]. It seemed to elevate in day 28, but was still lower than the controls. There were positive correlation between Smad 2/3, Smad 4 and TGF-beta(1) (r = 0.91, r = 0.71, respectively, P < 0.05) and also between Smad 2/3 and hydroxyproline contents of lung tissue (r = 0.85, P < 0.05) except Smad 7.

CONCLUSIONSmad protein may have certain association with pulmonary fibrosis in silicosis.

Animals ; DNA-Binding Proteins ; immunology ; metabolism ; Lung ; metabolism ; Male ; Mice ; Mice, Inbred Strains ; Pulmonary Fibrosis ; chemically induced ; metabolism ; Quartz ; toxicity ; Smad2 Protein ; Smad3 Protein ; Smad4 Protein ; Smad7 Protein ; Trans-Activators ; immunology ; metabolism ; Transforming Growth Factor beta ; metabolism

OBJECTIVETo evaluate the intramuscular loads of the upper limb during static postures and repetitive work by surface electromyography.

METHODSTwenty-six male college student volunteers were recruited for the experiment. The surface electromyography (SEMG) singal were recorded from the brachioradialis, biceps brachii, deltoid and trapezius of right arm during static postures including forward elevating, abducting, extending and a repetitive performance at different height of the bench, and root mean square (RMS) values were educed from the singal.

RESULTSThe SEMG amplitudes from forward elevating and abducting were in direct proportion to the angle of the elevating and abducting (r > 0.9, P < 0.01). The maximal voluntary electrical activation (MVE) of the deltoid were 6.4%, 10.1%, 12.6%, 16.2% and 20.8% while the arm elevated forward at an angle of 0 degrees , 45 degrees , 90 degrees , 135 degrees and 180 degrees respectively. The repetitive work showed that the height of the bench and the duration had more effects on deltoid and trapezius than the other muscles. The MVE% of the deltoid were 13.0%, 14.4% and 15.6% while the bench was 74, 79 and 84 cm in height respectively (P < 0.01).

CONCLUSIONSEMG which is suitable for determining and reflecting the muscle strain during static postures and repetitive work may be a reasonable indicator for the assessment of manual workload and the ergonomic design.

Arm ; physiology ; Electromyography ; Humans ; Male ; Muscle, Skeletal ; physiology ; Posture ; physiology ; Young Adult

OBJECTIVEUsing surface electromyography (SEMG) technique to evaluate repetitive lifting task-induced fatigue of back muscles.

METHODSThirteen volunteers lifted and lowered an 8 kg weight from floor to waist level for 100 times. Fatigue in the erector spinae muscles was quantified by comparing the frequency content of the EMG signal during static contractions performed before, and immediately after the 100 lifts.

RESULTSEMG average amplitude rose gradually during 100 lifts, the difference was significant at T10 right (P < 0.05) and L3 left (P < 0.01), the difference was not significant at T10 left and L3 right (P > 0.05). The median frequency intercept at T10 right, T10 left, L3 right, L3 left erector spinae muscles decreased by 2.0% (P > 0.05) 10.9% and 29.9% (P < 0.05), 27.9% (P < 0.01), respectively. The mean power frequency intercept decreased by 9% at L3 left erector spinae muscle (P < 0.05), the decrease was not statistically significant at other sites (P > 0.05).

CONCLUSIONRepetitive lifting may induce measurable fatigue in the erector spinae muscles. Erector spinae muscle at L3 is more easily fatigued than at T10. Using the median frequency intercept to assess muscle fatigue is more sensitive than using mean power frequency intercept.

Adult ; Back ; Electromyography ; Humans ; Lifting ; Male ; Muscle Fatigue ; physiology ; Muscle, Skeletal ; physiology

OBJECTIVETo investigate if heart rate variability (HRV) can be used to evaluate mental workload.

METHODSForty-six volunteers were selected to simulate mental work by inputting the random number through keyboards. ECG was recorded by Holter 8800 during the performance and transferred into digital signal. Total power (TP), low frequency (LF), high frequency (HF) were analysed by Holter software.

RESULTSAlong with time, the inputting speed increased but accuracy decreased, and was positively correlated with TP, LF (r = 0.851 and 0.827 respectively, P < 0.05), showing a distinct dose-effect relationship. HRV values at rest were higher than during mental work [TP: (2 745.4 +/- 1 301.6) vs (686.2 +/- 420.7) ms(2)/Hz; HF: (670.6 +/- 393.8) vs (202.6 +/- 171.7) ms(2)/Hz; LF: (870.5 +/- 553.7) vs (206.0 +/- 187.9) ms(2)/Hz] indicating that they were decreased remarkably as the mental work started. Then, they were gradually increased with the workload (intensity and time) increased, but still at lower level.

CONCLUSIONHRV may be used as a parameter to evaluate mental workload but the change pattern of HRV needs to study further.

Adult ; Electrocardiography, Ambulatory ; statistics & numerical data ; Evaluation Studies as Topic ; Female ; Heart Rate ; physiology ; Humans ; Male ; Mental Processes ; physiology ; Rest ; physiology ; Workload

OBJECTIVETo study the main risk factors of low back pain of workers ina foundry factory of the automobile company using cross sectional epidemiological investigation, and to provide scientific base for preventing the disorder.

METHODSThe low back pain and work loads of 1340 workers in a foundry factory of the automobile company were investigated using questionnaire, and logistic regression analysis was used to analyze the risk factors.

RESULTSThe one-year morbidity of low back pain in workers was 58.9% the morbidities of low back pain in workers engaged in foundry, transportation and modeling were 64.6%, 64.6% and 62.5%, respectively. The lifting with squat postures, bending trunk heavily, bending trunk with twisting and moving the heavy objects were found to be the most dominant risk factors for low-back pain, the OR values were 2.085, 1.961, 1.967 and 1.956, respectively. The distributions of risk factors were different among the different jobs. The logistic regression analysis showed that moving the heavy objects, lifting with squat postures, bending trunk heavily, bending trunk with twisting existed simultaneously, also the work years and gender were the risk factors.

CONCLUSIONThe manual moving heavy objects, awkward working posture or both were the most important risk factors for low-back pain. The intervene ergonomic study should be performed in future to reduce the morbidity of low-back pain.

Adult ; Automobiles ; Cross-Sectional Studies ; Female ; Humans ; Industry ; Logistic Models ; Low Back Pain ; epidemiology ; Male ; Middle Aged ; Occupational Diseases ; epidemiology ; Risk Factors ; Surveys and Questionnaires ; Workplace ; Young Adult

OBJECTIVETo provide a scientific basis for standardizing the cultivation method for Curcuma longa.

METHODPlant heights and seeding numbers were sampled periodically, the plot yields were counted a tharvested.

RESULTThe effects of seeding method on yields, plant height and number were significant. The effects of different sowing ways on the yields were very little.

CONCLUSIONThe hole seeding method using mother tuber or blastostyle bearing three to four knots was shown to be the best may, worthy to be widely applied in production.

Curcuma ; anatomy & histology ; growth & development ; Pharmacognosy ; Plants, Medicinal ; anatomy & histology ; growth & development ; Rhizome ; anatomy & histology ; growth & development ; Seedlings ; anatomy & histology ; growth & development

OBJECTIVETo investigate the gene expression of transforming growth factor-beta(1) (TGF-beta(1)) in lung tissues of silica-treated mice.

METHODSThe experimental mice were divided into control and silica group. 0.2 g/kg body weight of silica was injected intratracheally in silica group. Samples of lung tissue were collected 1, 3, 5, 7, 14 and 28 d after injection. RT-PCR method was used to analyze the gene expression of TGF-beta(1) in lung tissue of silica-treated mice.

RESULTSThe expression of TGF-beta(1) gene in lung tissue elevated from the 3rd day (1.20 +/- 0.15) and the peak value was on the 7th day (1.74 +/- 0.19). Then the expression decreased from the 14th to 28th day. But there was still higher than control until the 28th day.

CONCLUSIONTGF-beta(1) may play an important role in silica-induced pulmonary fibrosis.

Animals ; Gene Expression Regulation ; drug effects ; Lung ; drug effects ; metabolism ; pathology ; Male ; Mice ; Pulmonary Fibrosis ; etiology ; pathology ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Silicon Dioxide ; pharmacology ; toxicity ; Time Factors ; Transforming Growth Factor beta ; genetics

OBJECTIVETo investigate the protein expression of transforming growth factor-beta(1) (TGF-beta(1)) in lung tissues of silica-treated mice.

METHODSThe experimental mice were divided into control and silica groups. 0.2 g/kg body weight of silica was injected intratracheally in mice of silica group. Samples of lung tissue were collected 1, 3, 5, 7, 14 and 28 d after injection. The immunohistochemical method was used to analyze the protein expression of TGF-beta(1).

RESULTSIn control mice, the expression of TGF-beta(1) in lung tissue was slightly positive while it was markedly increased in silica-treated mice. The expression was significantly elevated from the 7th day to 14th day. The expression in alveolar macrophages reached the peak on the 5th day [(93.4% +/- 2.8%) vs (42.2% +/- 12.0%), P < 0.01].

CONCLUSIONTGF-beta(1) may play an important role in early development of silicosis.

Animals ; Immunohistochemistry ; methods ; Lung ; chemistry ; drug effects ; pathology ; Male ; Mice ; Pulmonary Fibrosis ; etiology ; pathology ; Silicon Dioxide ; pharmacology ; toxicity ; Silicosis ; etiology ; pathology ; Time Factors ; Transforming Growth Factor beta ; analysis

OBJECTIVETo explore the growth characteristics of Curcuma longa, and provide basis for standardized cultivation.

METHODPlant samples were collected and investigated periodically.

RESULTAccording to the growth of different parts and the characteristics of dry substance accumulation of C. longa, the development of C. longa could be divided into five stages: emergence of seedlings, seedling, leaf, root tuber expansion, and dry substance accumulation of root tuber. In terms of number, leaf of C. longa increases gradually from one at first to eight at the final stage. Leaf size increases at a very low speed at the stage of seedling. However, leaves expands their sizes at a much higher speed at the stage of leaf. The dry substance in different parts accumulates increasingly with the development of C. longa dry substance mainly accumulates in leaves at the stage of leaf, and in rhizome at the stage of root tuber expansion. At the final stage, it mainly accumulates in root tuber.

CONCLUSIONCultivation technologies of C. longa and the relevant management methods could be established according to the growth of different parts of C. longa and the characteristics of dry substance accumulation in different stages.

Curcuma ; anatomy & histology ; growth & development ; metabolism ; Desiccation ; Drugs, Chinese Herbal ; metabolism ; Plant Leaves ; anatomy & histology ; growth & development ; metabolism ; Plant Roots ; anatomy & histology ; growth & development ; metabolism

BACKGROUNDMyocardial infarction results in tissue necrosis, leading to cell loss and ultimately to cardiac failure. Implantation of skeletal muscle satellite cells into the scar area may compensate for the cell loss and provides a new strategy for infarct therapy. Vascular endothelial growth factor (VEGF) is a promising reagent for inducing myocardial angiogenesis. Skeletal myoblast transplantation has been shown to improve cardiac function in chronic heart failure models by regenerating muscle. We hypothesized that VEGF expression and vascular regeneration increased in infarcted myocardium by skeletal muscle satellite cells, which can promote vascular producing and improve survival environment in infarcted myocardium.

METHODSThe skeletal muscle satellite cells were implanted into the infarcted myocardium in a model through ligated left anterior artery in Louis Inbrad Strain rat. Specimens were got for identifying the expression of VEGF and the density of vascular by immunochemical method at two weeks after implantation.

RESULTSThe proliferation and differentiation of the skeletal muscle satellite cell was very well. The expression of VEGF was higher in the implanted group (146.83 +/- 2.49) than that in the control group (134.26 +/- 6.84) (P < 0.05). The vascular density in the implanted group (13.00 +/- 1.51) was also higher than that in the control (10.68 +/- 1.79) (P < 0.05).

CONCLUSIONThe implanted satellite cell could excrete growth factor that would induce angiogenesis and improve cell survival environment in infarcted myocardium.

Animals ; Cell Proliferation ; Cells, Cultured ; Myocardial Infarction ; physiopathology ; therapy ; Neovascularization, Physiologic ; RNA, Messenger ; analysis ; Rats ; Regeneration ; Satellite Cells, Skeletal Muscle ; cytology ; transplantation ; Vascular Endothelial Growth Factor A ; genetics