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OBJECTIVE: To evaluate the application value of finger systolic blood pressure(FSBP) in the diagnosis of vibration-induced vascular injury. METHODS: Thirty patients with vibration-induced vascular injury [vibration-induced white finger(VWF)] were selected as the case group by a non-randomized concurrent controlled trial, and 30 hand-transmitted vibration workers without VWF were selected as the control group. The FSBP test was performed on the tested hands of all subjects, and the FSBP index of each Finger(F_( i)) was measured. RESULTS: The F_i of the index finger, middle finger, ring finger and tail finger of the tested hand in the case group were lower than that in the control group(all P<0.01). In the case group, the F_i of index finger was lower than ring finger and tail finger(all P<0.01). The abnormal rates of F_i on the index, middle and ring fingers in the case group were higher than those in the control group(86.7% vs 10.0%, 76.7% vs 13.3%, 43.3% vs 10.0%, all P<0.01). The area under the receiver operator characteristic curve of the measured F_i of the index finger, middle finger, ring finger and tail finger were 0.884, 0.843, 0.764 and 0.687 respectively. The diagnostic cut off value of the F_i of index finger was 80.2%. The sensitivity and specificity were 86.7% and 90.0%, respectively. CONCLUSION: FSBP test has a good application value in the diagnosis of vibration-induced vascular injuries. It is suggested that the F_i of index finger be the first choice as the diagnostic index, and the abnormal value can be set at 80.0%.
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OBJECTIVE: To analyze the stability of test results of fingertip thermotactile perception threshold(TPT) among healthy individuals and the influencing factors of the TPT test. METHODS: Fifty healthy young volunteers aged 20-25 were selected as the study subjects using the convenience sampling method. The HVLab thermal aesthesiometer was used to perform the fingertip TPT test under the standard condition. Right index, middle, ring, little, left index and little fingers were tested. According to the method of random number table, we selected 25 subjects to receive second test after the interval of two weeks. RESULTS: Intraclass correlation coefficient(ICC) for cold threshold of right little finger was bigger than 0.75, suggesting the test-retest reliability was excellent. The ICC for hot threshold of six test fingers, cold threshold of right and left index fingers, right middle and left little finges was in the range of 0.60-0.74, indicating the test-retest reliability was good. However, the ICC for cold threshold of right ring finger was less than 0.40, and the test-retest reliability was poor. The hot threshold of right middle, ring and little fingers, and the cold threshold of left little finger of males were higher than those of females(all P<0.05). The cold threshold of right index and little fingers were lower than those of left hand in males(all P<0.05). The cold threshold of right middle and ring fingers were lower than that of the right index finger in females(all P<0.05). The cold threshold of right little finger was lower than those of right index, middle and ring fingers in females(all P<0.05). CONCLUSION: The stability of the fingertip TPT result is good in healthy young adults aged 20-25. The fingertip TPT test could be used for occupational health surveillance of workers exposed to hand-transmitted vibration. We should take into account the influence of gender, the right or left hand and different fingers when developing TPT reference values.
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OBJECTIVE: To test and analyze the vibration transmissivity of three common kinds of protective gloves, and to determine their actual protecting effect. METHODS: Three kinds of protective gloves were selected as test materials, and five healthy volunteers were selected as subjects using typical sampling methods. According to the ISO 10819:2013 Mechanical Vibration and Shock--Hand-arm Vibration--Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand(hereinafter referred to as ISO 10819:2013), investigation and measurement of basic parameters of protective gloves. The gloved vibration transmission(GVT) test system was used to test the vibration transmission of different protective gloves worn by the subjects, and the spectrum analysis of vibration reduction characteristics was carried out. RESULTS: The thickness of damping material of all the three kinds of protective gloves met the standard requirements. The mean value for the corrected frequency-weighted glove vibration transmissibility values at 25.0-200.0 Hz were 0.91, 0.75 and 0.94, and 1.05, 0.85 and 1.10 at 200.0-1 250.0 Hz, for the protective gloves A, B and C, respectively. The results of anti-vibration characteristic spectrum analysis show that there has no vibration reduction effect at the frequency of 25.0-200.0 Hz when wearing these three kinds of gloves. Wearing gloves A and B on part of the 200.0-1 250.0 Hz frequency vibration has an amplifying effect. Wearing glove C has a partial vibration reduction effect at the 200.0-1 250.0 Hz frequency, and the vibration reduction efficiency is the highest at the frequency of 1 250.0 Hz.CONCLUSION: According to the ISO 10819:2013 standard, the mean value of GVT measured when wearing the three kinds of protective gloves does not meet the relevant requirements, and the anti-vibration effect is poor. These gloves cannot be defined as anti-vibration gloves.
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OBJECTIVE: To study the occupational exposure characteristics of hand-transmitted vibration in hand-held workpiece polishing and to provide the basis for occupational hazard prevention and control technology research in this kind of job. METHODS: The questionnaire and on site occupational health investigation were used to study 4 typical enterprises of hand-held workpiece polishing. The study was conducted by filling forms by enterprise,personal interviews with administrative staffs and front-line workers,as well as on site visit. RESULTS: Among the 4 factories,there were 835workers( 22. 4%) engaged in the hand-held workpiece polishing assignment. The principal vibrating tools used in these 4factories were polishing machine,flint glazing machine and polishing wheel,and the workpiece polished by workers were button,toilet lid,thermos,mobile phone shell and golf head. The polishing workers were all equipped with noise reduction earplugs and anti-dust respirators, but they did not wear anti-vibration gloves. The hand-held workpiece polishing assignment has the characteristics including indirect and continuous vibration exposure and fine operation. Some workers used their knees and abdomens as the support to polish workpieces. The vibration exposure time was 6-11 h / d. The 4hours energy equivalent frequency-weighted acceleration to vibration [ahw( 4)]was 1. 9-19. 4 m/s~2,with the maximum which exceeded the occupational exposure limit( 5. 0 m / s~2),showing a wide range ahw( 4)in the same enterprise. CONCLUSION: Compared with the traditional vibrating tools,the hand-held workpiece polishing operation has different characteristics of hand-transmitted vibration such as more sophisticated machine structure,finer polishing ways,more influencing factors of vibration exposure level and more extensive body parts involved.
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OBJECTIVE: To analyze the effects of hand-transmitted vibration exposure on the finger vibratory and pain perception thresholds among drill workers in a gold mine. METHODS: By the judgement sampling method,134 male drill workers from a gold mine in the northern area of China were selected as the hand-transmitted vibration exposure group and102 fit-up workers without vibration exposure in the same mine were chosen as the control group. The finger vibratory perception thresholds,the pain perception thresholds and the occupational health examination were conducted and analyzed in these two groups. Based on the self-report with vibration-induced white finger( VWF),the workers of hand-transmitted vibration exposure group were divided into non-VWF subgroup( 105 workers) and VWF subgroup( 29 workers). RESULTS: The incidence of finger numbness,pain and self-reported white finger in the exposure group were significantly higher than those in the control group( P < 0. 05). Compared with the control group,the vibratory perception thresholds of the index finger,middle finger and ring finger of the right hand among the vibration exposure group workers were significantly higher( P < 0. 05),but there was no significant difference in the vibratory perception thresholds of the left ring finger between the two groups( P > 0. 05). The vibratory perception thresholds of both ring fingers,right index finger and right middle-finger in VWF subgroup were higher than those in control group( P < 0. 05). But no significant differences was found in the above 4 indexes in these two groups after compared to those of control group,respectively( P > 0. 05). The vibratory perception thresholds of left ring finger,right ring finger and right index finger in VWF subgroup were all higher than those in non-VWF subgroup( P < 0. 05),but the vibratory perception thresholds of right middle finger in these two groups showed no significant difference( P > 0. 05). The pain perception thresholds of index finger,middle finger and ring finger in both hands of the vibration exposure group workers were all higher than those in control group( P < 0. 05). The pain perception thresholds of middle finger and ring finger in both hands of the VWF subgroup and non-VWF subgroup were higher than those of control group( P < 0. 05). CONCLUSION: The hand-transmitted vibration can increase the thresholds of finger vibratory and pain perception in drill workers. The finger sensory perception examination could be used to assist the early detection of peripheral nerve damage induced by hand-transmitted vibration.
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OBJECTIVE: To analyze the correlation between four vessel regulate factors and vibration-induced white finger( VWF) evaluating in workers exposed to hand-arm vibration,and discuss the value of regulate factors for VWF screening.METHODS: Using typical sampling method,77 male workers exposed to hand-arm vibration with more than 1 year of polish work from a metalwork factory were selected as the study subjects. Based on the workers' self-report,they were divided into VWF group( 43 workers) and non-VWF group( 34 workers). The venous blood from center elbow was collected and plasma was separated. The plasma level of endothelin( ET) was detected by radioimmunoassay. The plasma levels of transforming growth factor beta( TGF-β),soluble intercellular adhesion molecule-1( s ICAM-1) and 5-hydroxytryptamine( 5-HT) were detected by enzyme-linked immunosorbent assay. The regulate factors for evaluating VWF were screened and the new multivariable model index
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OBJECTIVE: To evaluate the major influence factors affecting the quality and accuracy of measuring instruments for power frequency electromagnetic fields in occupational hygiene technical service organizations by developing interlaboratory comparison in workplaces. METHODS: Six measuring instruments for power electromagnetic fields from 6occupational hygiene technical service organizations in Guangdong Province were selected by typical sampling method. A high-voltage substation was selected as a standard source. We set measurement sites underneath it as inter-laboratory comparison spots for power frequency electromagnetic fields. The stability of the standard source was evaluated by pairedsamples t-test and measure results were analyzed by z-score evaluation method based on quartile robust statistical technology. RESULTS: During and after the inter-laboratory comparison,the intensity of electric field and magnetic field of the standard source showed no significant difference [( 555. 03 ± 2. 94) vs( 555. 68 ± 3. 20) V / m,( 2. 30 ± 0. 06) vs( 2. 29 ± 0. 07) μT,P > 0. 05],which met the demand of stability of inter-laboratory comparison. The data of electric field measured by 2 measuring instruments without remote-reading system were found to be high because of proximity effect from its handheld status. The z-score of inter-laboratory( zB) of other 4 measuring instruments with remote-reading system ranged from- 0. 52 to 1. 10,while the z-score of within-laboratory( zW) ranged from- 1. 28 to 0. 37,and both results of| zB| and | zW| were satisfactory( < 2. 00). The zBof power frequency magnetic field measured by the 6 measuring instruments ranged from- 0. 67 to 1. 26,while zWranged from- 0. 59 to 0. 90,and both | zB| and | zW| were also satisfactory( < 2. 00). CONCLUSION: It is feasible that the inter-laboratory comparison of measuring instruments of power frequency electromagnetic fields could be implemented by a high-voltage substation as a standard source. The measuring instruments without remote-reading system could be used to measure the intensity of magnetic field but not the electric field. The measuring instruments with remote-reading system could be used to measure the intensity of either the electric field or the magnetic field,and the measurement results are satisfactory.
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<p><b>OBJECTIVE</b>To investigate the relative factors of burn injury among primary and secondary school students in Guangzhou and to provide scientific evidence for intervention.</p><p><b>METHODS</b>1:1 case-control study was conducted in 428 cases and 428 controls based on different sex and classes. The relationship between relative factors and burn injury was analyzed by univariate and multivariate conditional logistic regression.</p><p><b>RESULTS</b>Following facts were discovered: burn injury mainly occurred in the upper limbs (57.9%), home was the place that most of burn injury (58.2%) took place, 51.0% of the burn injuries was caused by hot liquid, 43.9% burn injury needed medical treatment and 7.7% burn injury left with sequelae as dysfunction or disability. Data from the multivariate conditional logistic regression showed that boarding students (OR = 2.47), older age of the mothers (OR = 1.03), non-nuclear family (OR = 1.25 - 1.84) were risk factors of burn injury. Being the only child (OR = 0.60), having sufficient time for sleep (OR = 0.84), good performance record (OR = 0.85), higher maternal education background were protective factors on burn injury.</p><p><b>CONCLUSION</b>Among primary and secondary school students in Guangzhou, burn injury mainly occurred in the upper limbs, and home was the place that most of burn injury took place.</p>
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Adolescent , Child , Female , Humans , Male , Burns , Epidemiology , Case-Control Studies , China , Epidemiology , Logistic Models , Risk Factors , StudentsABSTRACT
<p><b>BACKGROUND</b>The purposes of this study were to confirm the changes in myocardial collagen level after left ventricular assist device (LVAD) support in dilated cardiomyopathy (DCM), find the relation between these changes and prognosis, and test a practical method to assess the level of myocardial collagen.</p><p><b>METHODS</b>Left ventricular samples were collected from DCM patients with different prognosis (transplanted group n = 8, weaning group n = 10) at the time when the LVADs were implanted and again during cardiac transplantation (n = 8). The level of neutral salt soluble collagen (NSC) and acid soluble collagen (ASC) was measured by Sircol collagen assay, and that of total collagen and insoluble collagen (ISC) by quantification of hydroxyproline (Hyp). Serum samples were collected from a portion of these patients (transplanted group, n = 6; weaning group n = 7) at the time the LVADs were implanted, 1 month after implantation and on explantation. Circulating concentration of carboxy-terminal propeptide of type I procollagen (P I CP), amino-terminal propeptide of type I procollagen (P I NP), amino-terminal propeptide of type III procollagen (P III NP) and type I collagen telopeptide (I CTP) were measured by the equilibrium type radioimmunoassay.</p><p><b>RESULTS</b>Before LVAD implantation the level of NSC and ISC in the weaning group was higher but ASC in the transplanted group was lower than in the controls (P < 0.05). After LVAD support, the level of total collagen was higher, but ASC was also lower in the transplanted group than in the controls (P < 0.05). In comparison of the pre- and post-LVAD subgroups of the transplanted and weaning groups, all collagen fraction levels before LVAD implantation were lower in the transplanted group than in the weaning group (P < 0.05); but this difference disappeared after LVAD support. Comparison of the pre- and post-LVAD subgroups of the transplanted group showed increased level of NSC and total collagen after LVAD support. The changes of serum peptide concentration showed that P III NP increased constantly in the transplanted group, but P I CP and P I NP increased in the weaning group after LVAD implantation.</p><p><b>CONCLUSIONS</b>The changes in myocardial collagen level as a sign of myocardial interstitial remodeling in DCM are not involved with total collagen but involved with collagen fractions, and they are related to prognosis. The changes of myocardial collagen content and serum procollagen peptide after LVAD support can be regarded as an expression of the reverse of maladaptive myocardial interstitial remodeling.</p>