OBJECTIVETo observe changes of thromboxane B2 (TXB2), 6-keto-prostaglandin F1 alpha(6-Keto-PGF1 alpha) and TXB2/6-Keto-PGF1 alpha (T/P) in lungs of rats drowned in hypothermic sea water and to assess their influence on the blood-gas.

METHODSRats of different groups were drowned nearly to death in hypothermic sea water and then taken out of the water rapidly, observed at room temperature, after that the following steps were taken in 5, 15, 30, 60, 240 min and 360 min groups, that were 1 ml arterial blood taken from left heart for blood-gas analysis including pH, PaO2 and PaCO2, rectal temperature observed; at last, the ratio of left dry lungs with left wet lungs was assessed, TXB2 and 6-Keto-PGF1 alpha in right lungs were examined in all above groups and dead group(14 rats dead, only 4 examined).

RESULTSThe rectal temperature[(20.13 +/- 0.48) degree C], pH(6.68 +/- 0.03), PaO2[(45.00 +/- 6.30) mm Hg)], TXB2[(97.46 +/- 17.46) ng/L] and 6-Keto-PGF1 alpha[(25.59 +/- 8.12) ng/L] dropped to the lowest point in the 5 minutes group(P < 0.01), while PaCO2[(89.18 +/- 5.10) mm Hg] reached the highest point(P < 0.01), all above items from 5 minutes group then showed a recovering tendency, but only the pH in 240 minutes and 360 minutes groups as well as TXB2 in 360 minutes group and dead group reached near the level of normal control groups (P > 0.05); T/P had a rising tendency and reached the highest point in the 360 minutes group.

CONCLUSIONSThe production and secretion of TXB2 and 6-Keto-PGF1 alpha were influenced by hypothermia, hypoxemia and acidosis, the imbalance of T/P could be one of factors influencing the improvement of blood gas index.

6-Ketoprostaglandin F1 alpha ; analysis ; Animals ; Body Temperature ; Carbon Dioxide ; blood ; Drowning ; metabolism ; Hypothermia ; metabolism ; Lung ; chemistry ; Oxygen ; blood ; Rats ; Seawater ; Thromboxane B2 ; analysis

OBJECTIVETo investigate clinical and imaging characteristics of delayed encephalopathy after carbon monoxide poisoning(DEACMP).

METHODSA retrospective and comparative analysis of neurological manifestations, course, periods of false-cure, prognosis and neuroimaging findings were conducted in 198 patients with DEACMP.

RESULTSOf these patients, 60.1% obtained an initial recovery within 30 d, 23.7% within 31-60 d and 14.6% over 60 d. Total clinical rate was 32.8%, and effectiveness rate 70.1%. According to imaging findings, 15.2% patients were found to have bilateral lesions of basal ganglion, and 70.0% with lesions of subcortical white matter, 12.6% with lesions of two types above mentioned and 2.1% with no lesions. The intervals between onset of illness and initial recovery were (44.6 +/- 10.1), (38.2 +/- 11.9), (61.3 +/- 17.0) d, and (7.5 +/- 2.4) d respectively. Imaging findings can demonstrate the severity of brain injury, but not necessarily parallel to the improvement of illness, for which SPECT proves more useful.

CONCLUSIONSDEACMP is involved in ischemic brain injury and a self-limited illness.

Brain Diseases ; etiology ; Carbon Monoxide Poisoning ; complications ; Humans ; Retrospective Studies ; Tomography, Emission-Computed, Single-Photon

OBJECTIVETo study the relationship between occupational stress and psychological health state among oil workers.

METHODS1,230 oil workers in 122 work types of oil industry were selected and written occupational stress questionary(OSQ) and symptom check list (SCL-90).

RESULTSPetroleum workers' psychological health states were poor with increasing occupational stress degree. The scores in physical symptoms(1.87 +/- 0.80, 1.72 +/- 0.70), depression(1.74 +/- 0.76, 1.62 +/- 0.67), horror(1.48 +/- 0.65, 1.39 +/- 0.55) in the high and medium stress group were obviously higher than those in low stress group(1.55 +/- 0.61, 1.43 +/- 0.54, 1.28 +/- 0.46, respectively, P < 0.05). The score of mood state in the high and medium stress group was obviously higher than that in low stress group(P < 0.05). Psychological health states and mood state in the petroleum workers with short service length are significantly poorer than that with long service length(P < 0.01).

CONCLUSIONOccupational stress should affect psychological health state of petroleum workers.

Affect ; Humans ; Mental Health ; Occupational Diseases ; psychology ; Petroleum ; Stress, Psychological ; psychology

OBJECTIVEExplore the hygienic status of indoor environment in railway air-conditioned passenger trains.

METHODSWe carried out a hygienic investigation of various air-conditioned passenger trains on total 10 railway lines in Shanghai, Chengtu, Kunming, Harbin, Urumchi and Guangzhou railway bureaus for two years between July, 1997 and Oct., 1999. The monitoring was conducted on difference train cars at different time, different railway status. The control groups were selected in the same condition.

RESULTSThe results of temperature and wind speed in air-conditioned trains both meet with the national standards GB 9673-1996 in summer and winter. The humidity in summer exceeded the national standards. Of different railways the status, the noise in four different cars except dining cars exceeded the national standards. The results of shock demonstrated that all measure up to the standards of ISO 2631/1-85. As to indoor air quality, the concentration of CO in air-conditioned trains in difference seasons(summer, autumn, winter) all met with the national standards, the ratio was 100%. In summer, the concentrations of CO2 in hard seat cars and soft berth car exceeded the national standard with a statistic significance(P < 0.01). In winter, the concentrations of CO2 in soft berth and hard berth cars both exceeded the same standard. The results of inhalable particulate matter(IP) and total count of bacteria all satisfied the standards, meanwhile the natural lighting and artificial illumination in air-conditioned train cars all were superior to that in ordinary trains.

CONCLUSIONHumidity in summer and noise in dining car exceeded the standards, the concentration of CO2 in different cars in summer and winter exceeded the standards in some degrees.

Air Conditioning ; Air Pollution, Indoor ; Carbon Dioxide ; analysis ; Environmental Monitoring ; Humidity ; Motor Vehicles ; standards ; Particulate Matter ; analysis ; Seasons

OBJECTIVETo study whether previously intravenous injection of anisodamine can prevent endotoxemia of heat stroke of rats.

METHODSExperimental animals were randomly divided into two groups, their average artery pressure, heart rate, survival time, survival rate and rectal temperature were measured at an environmental temperature of 38 degrees C-40 degrees C and 50%-60% retative humidity. Blood samples for endotoxins analyses were taken both before and after heat-stress.

RESULTSDuring heat stress, the animals of rectal temperature of the experimental and control groups continuously increased and two hours later, separately to (42.7 +/- 0.6) degree C and (43.1 +/- 0.5) degree C, without statistic difference(P > 0.05), and to (44.6 +/- 0.4) degree C and (44.2 +/- 0.3) degree C prior to death, with statistic difference(P < 0.05). Before the experiment, the contents of endotoxins of portal vein blood were (45.7 +/- 5.2) pg/ml and (42.6 +/- 5.4) pg/ml, and that of systemic blood was (14.8 +/- 4.5) pg/ml and (13.9 +/- 7.2) pg/ml, without statistic difference(P > 0.05). Two hours later, the contents of portal vein blood separately increased to (122.2 +/- 16.7) pg/ml and (49.7 +/- 10.2) pg/ml, obviously higher than that before heat-stress(P < 0.01). And there were clear statistic difference between the two groups(P < 0.01). The changing tendency of the heart rhythm is almost the same in two groups, that is, first rose and then fell. But it is without statistic difference before and two hours later(P > 0.05): before heat-stress, the average artery pressures were (13.3 +/- 0.6) kPa and (13.6 +/- 0.5) kPa, without statistic difference(P > 0.05), and two hours later, were (9.6 +/- 0.5) kPa and (8.6 +/- 0.6) kPa, with obvious statistic difference(P < 0.01). The survival time of the animals were (166.5 +/- 16.9) min and (144.5 +/- 18.2) min with obvious statistic difference(P < 0.01), the survival rate of heat stressed rats in the experimental group were obviously higher than control group(P < 0.01 or P < 0.05).

CONCLUSIONSAnisodamine can prevent endotoxemia in rats suffering heat stroke.

Animals ; Blood Pressure ; Body Temperature ; Endotoxemia ; prevention & control ; Endotoxins ; blood ; Heat Stress Disorders ; drug therapy ; mortality ; physiopathology ; Hot Temperature ; Rats ; Solanaceous Alkaloids ; therapeutic use ; Survival Rate

OBJECTIVETo investigate the variation and the effect of TNF and NO in the process of the creation of protective heat stress model and provide more thoretical basis.

METHODSThe rats were properly treated with heat and then the serum was separated. Radioimmunoassay and nitrate reductase assay were employed to measure the concentration of TNF and NO at different time between 0 h and 24 h after heat stress respectively.

RESULTSCompared with the control, the concentration of TNF increased significantly 2 h, 4 h, 8 h, 12 h after heat stress, of which 2 h, 12 h(P < 0.05), 4 h, 8 h(P < 0.01), but no significant changes 0 h, 24 h after heat stress. The concentration reached the peak 4 h after heat stress[(3.35 +/- 0.20) ng/ml] and increased significantly than 0 h, 2 h, 8 h, 12 h, 24 h after heat stress(P < 0.01, P < 0.05). 24 h after heat stress it recovered to normal standard. Compared with the control, the concentration of NO was higher 2 h, 4 h, 8 h, 12 h, 24 h after heat stress(P < 0.05), but no significance at 0 h. The concentration amounted to peak 8 h after heat stress[(108.21 +/- 27.89) mumol/L] and increased than 0 h, 2 h, 4 h after heat stress(P < 0.01). After 8 h it began to decrease continuously in heat stress group, however it was higher 24 h after heat stress than control.

CONCLUSIONTNF and NO played an important role in the process of the creation of protective heat stress model.

Animals ; Disease Models, Animal ; Heat Stress Disorders ; prevention & control ; Nitric Oxide ; blood ; physiology ; Rats ; Time Factors ; Tumor Necrosis Factor-alpha ; blood ; physiology

OBJECTIVETo study lumbar vertebral degenerations of coal miners with low back pain.

METHODS40 underground miners with low back pain, aged from 30 to 50 years and employed for a length from 10 to 30 years, were taken as observation group. 30 ground workers without low back pain but with almost the same age, employment length and height etc. were selected as control group. Intervertebral discs at L3/L4, L4/L5, L5/S1 were scanned with computerized tomography, comparing herniated discs, sagittal diameter of vertebral canal, height of lateral recess, vertebral hypertostosis, ligament hypertrophy and calcification between two groups.

RESULTSL3/L4, L4/L5, L5/S1 herniated discs and narrow lateral recess in observation group(0.33 +/- 0.15, 0.53 +/- 0.25, 0.45 +/- 0.18 and 0.40 +/- 0.08, 0.31 +/- 0.05, 0.37 +/- 0.07) were more serious than that in control group(0.28 +/- 0.11, 0.32 +/- 0.21, 0.37 +/- 0.19 and 0.42 +/- 0.10, 0.43 +/- 0.07, 0.40 +/- 0.06), but only with significant difference at L4/L5 (P < 0.01). Sagittal diameter of vertebral canal in observation group is narrower than that in control group but of little significance(P > 0.05). Cases of vertebral hyperostosis, ligament hypertrophy and calcification were found more frequent in observation group(45.00%, 42.50%, 22.50%) than in control group(23.33%, 16.67%, 16.67%), but only ligament hypertrophy was remarkable(P < 0.05).

CONCLUSIONSAs compared with control group lumbar vertebral degenerations are more serious in underground miners with manifestations like herniated disc and narrow lateral recess mainly at L4/L5.

Adult ; Coal Mining ; Humans ; Low Back Pain ; diagnostic imaging ; Middle Aged ; Spinal Diseases ; diagnostic imaging ; Spine ; diagnostic imaging ; Tomography, X-Ray Computed ; methods

OBJECTIVETo study injury of liver and kidney among the workers exposed to terephthalic acid(TPA), ethylene glycol(EG) and(or) dowtherm A(DOW), and research for early biological monitoring indexes.

METHODSBy using the method of occupational epidemiology, an investigation of industrial hygiene in a chemical fibre corporation was carried out and the changes of the liver and kidney functions were analyzed among the workers who had been exposed to TPA, EG, DOW.

RESULTSThe values of serum gamma-glutamyl traspetidase(GGT) and total bile acid(TBA) in TPA + EG + DOW group men were (35.45 +/- 16.09) U/L, (10.29 +/- 6.76) mumol/L respectively and the values of serum alanine transaminase(ALT) and TBA in TPA + EG + DOW group women were(30.68 +/- 8.58) U/L, (9.53 +/- 6.63) mumol/L respectively, significantly higher than those in TPA, DOW and control groups(P < 0.05, P < 0.01). Compared with TPA, DOW and control groups, the values of urine N-acetyl-beta-D-glucosaminidase(NAG) and beta 2-2-microglobulim (beta 2-MG) in TPA + EG + DOW group of both men and women increased significantly(P < 0.05, P < 0.01), with(5.68 +/- 4.01) U/mmol Cr and (23.49 +/- 13.44) mg/mol Cr, and(6.68 +/- 4.68) U/mmol Cr and (22.80 +/- 13.00) mg/mol Cr, respectively. Analysis of regression indicated that both liver and renal injuries of the workers were evidently correlated with their exposure to TPA, EG and DOW after adjustment for the confounding factors such as sex, smoking, drinking, etc(P < 0.001).

CONCLUSIONBased on available knowledge, it is reasonable to assume that the joint actions should be considered on the injury of liver and kidney caused by TPA, EG and(or) DOW among the workers. Serum ALT, GGT, TBA, urine NAG and beta 2-MG should be suggested as biomarkers for liver and kidney damage.

Acetylglucosaminidase ; urine ; Alanine Transaminase ; blood ; Bile Acids and Salts ; blood ; Ethylene Glycol ; toxicity ; Female ; Humans ; Kidney ; drug effects ; Liver ; drug effects ; Male ; Occupational Exposure ; adverse effects ; Phenyl Ethers ; toxicity ; Phthalic Acids ; toxicity ; gamma-Glutamyltransferase ; blood

OBJECTIVETo investigate the epidemiological characteristics of lower back pain of truck drivers in plateau areas with an analysis of the causes and evaluated the effects of the protective measures.

METHODSThe self-reported lower back symptom was investigated by questionnaire in 1,132 male drivers in plateau areas. Vibration of the driver lumbar back was measured real time with or without wearing corset. Study the effect of the special corset for drivers and the massage on back by self-control design of big sample intervention experiments.

RESULTSThe prevalence of lower back pain of drivers in plateau areas was 86.1%. High level of its prevalence is due to many factors. Special corset for drivers and massage on back by themselves can reduce the degree of the pain.

CONCLUSIONDriving in plateau areas is a special occupational work with high level of prevalence of lower back pain which can be prevented.

Automobile Driving ; Humans ; Low Back Pain ; epidemiology ; etiology ; prevention & control ; Male ; Occupational Diseases ; etiology ; prevention & control ; Prevalence ; Surveys and Questionnaires

OBJECTIVETo evaluate the role of muscle fatigue in the pathogenesis of high prevalence of low back pain(LBP) in drivers who work at high altitude, in order to seek the effective measures for prevention and treatment of LBP.

METHODThe spectral electromyographic(EMG) changes during isometric contraction of erector spinalis to fatigue in 26 drivers in the field were consecutively recorded after daily driving for 5 days. The relationship between the decline of median frequency and the development of the back extensor fatigue were analyzed.

RESULTSThe decline rates of EMG median frequency of the erector spinalis on 1-5 working day [(-0.258 +/- 0.087), (-0.248 +/- 0.070), (-0.256 +/- 0.097), (-0.267 +/- 0.093), (-0.274 +/- 0.081)%/s respectively] were significantly different from that of baseline measured before work [(-0.175 +/- 0.114)%/s, P < 0.05 or P < 0.01]. A positive correlation was also found between the decline rate and the working time(r = -0.809, P < 0.05).

CONCLUSIONThe high prevalence of LBP in the drivers working at high altitude is due to acumulative fatigue of back extensor resulting from long-distance driving, lack of proper rest, decrease of muscle endurance and increase of liability to fatigue, consequently leading to the muscle dysfunction and finally LBP.

Altitude ; Automobile Driving ; Electromyography ; Humans ; Low Back Pain ; etiology ; physiopathology ; Muscle Fatigue ; physiology ; Occupational Diseases ; etiology