Adult ; China ; epidemiology ; Extraction and Processing Industry ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Occupational Exposure ; Pneumoconiosis ; epidemiology ; Young Adult

OBJECTIVETo investigate lifting-related musculoskeletal disorders in metal processing, to analyze the risk factors, and to study the validity and feasibility of using NIOSH lifting equation in China.

METHODSThe questionnaires of semi-structured interview, the Ovako Working Posture Analysing System (OWAS) postural analysis and variables of the NIOSH equation were applied to the study. The study population consisted of 69 workers mainly involved in manual materials handling (MMH), categorized as Job A; and 51 machinery workers, served as controls, that were less MMH task involved, as Job B.

RESULTSThe prevalence of low back pain (LBP), which was defined at least one episode lasting for more than 24 hours in the past 12 months, were 63.8% and 37.3% for Job A and Job B, respectively. However, the prevalence of LBP lasting for more than a week due to lifting were 26.09% and 5.88% for Job A and B, respectively. The proportion of awkward back postures were found higher in Job A than that of Job B (66% vs 63%, P < 0.05). The NIOSH Lifting Index (LI) was estimated to be 2.4 for Job A, and 0 < LI < 1 for Job B. The analysis of multiple regressions revealed that the repetitiveness of lifting and length of service had greatly attributed to the occurrence of LBP. The "composite load" (object weight x activity repetitiveness) had a significant adverse effect on lower back meaning that the objective weight remains an ingredient part of the risk.

CONCLUSIONThe occurrence of LBP is not only related to the force load, but the repetitiveness of lifting and awkward postures. The method of OWAS observation and US-NIOSH equation are important tools in assessing characteristics and risk factors of LBP for MMH tasks. Further study aimed at developing an integral scheme for the assessment system is needed.

Adult ; Back Injuries ; epidemiology ; etiology ; China ; epidemiology ; Female ; Humans ; Male ; Metallurgy ; Middle Aged ; Musculoskeletal Diseases ; epidemiology ; etiology ; Occupational Diseases ; epidemiology ; etiology ; Prevalence ; Risk Factors ; Surveys and Questionnaires ; Time Factors ; Weight Lifting ; injuries

OBJECTIVETo study the effect of Hongjingtian (Gadol) injection on cardiac hemodynamics and myocardial oxygen consumption for analyzing its underlying mechanism in the treatment of coronary heart disease.

METHODA total of 20 dogs anesthetized with pentobarbital sodium (30 mg x kg(-1), i.v.) were evenly randomized into control group, low-dose Gadol (LDG) group, high-dose Gadol (HDG) group and Herbesser Injection group. The blood flow volume (BFV) of the left coronary artery and cardiac output (CO), left ventricular pressure (LVP), maximum ascending rate (dp/dtmax) of LVP, mean arterial pressure (MAP) of the femoral artery, oxygen contents of the coronary artery and coronary vein (venous sinus), oxygen consumption index (OCI), cardiac index (CI), coronary artery resistance (CAR) and total peripheral resistance (TPR) as well as oxygen utilization rate (OUR) were detected respectively.

RESULTAfter venous injection of Gadol, CAR, MAP, TPR, OCI, myocardial oxygen consumption and heart rate lowered significantly (P < 0.05-0.01), while BFV and blood oxygen content of the venous sinus increased considerably (P < 0.05-0.01) in comparison with pre-injection. No significant differences were found in LVP and myocardial contractivity between control group and LDG, and between control and HDG groups respectively.

CONCLUSIONIt showed dilation of the coronary artery and reduction of the cardiac afterload after injection of Gadol. Besides, CO and stroke volume increased considerably and the cardiac effective work was raised without any significant simultaneous increase of both myocardial contractility and LVP. A decrease in the myocardial oxygen consumption and reduction of OCI indicates an improvement of the oxygen supply of the myocardium, and a favorable regulation of the compliance of the cardiac vessels. As a result, the cardiovascular performance was ameliorated. The abovementioned improvement of these indexes may contribute to the therapeutic effect of Gadol in the treatment of coronary heart disease in clinic.

Animals ; Blood Pressure ; drug effects ; Cardiac Output ; drug effects ; Dogs ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Heart Rate ; drug effects ; Hemodynamics ; drug effects ; Injections, Intravenous ; Male ; Myocardium ; metabolism ; Oxygen ; metabolism ; Plants, Medicinal ; chemistry ; Random Allocation ; Rhodiola ; chemistry ; Vascular Resistance ; drug effects