[A prospective study of position selection combined with autologous blood intrathoracic infusion in the treatment of postoperative persistent air leakage with an unexpanded lung]

We prospectively studied 17 patients with spontaneous pneumothorax or giant emphysematous bulla at Rizhao Hospital of Traditional Chinese Medicine from October 2020 to March 2022. All patients underwent thoracoscopic interventional therapy, had experienced continued air leakage for 3 days with closed thoracic drainage postoperatively, had an unexpanded lung on CT, and/or failed to intervention with position selection combined with intra-pleural thrombin injection(referred to as "position plus1.0"). They were all treated with position selection combined with autologous blood (100 ml) and thrombin (5 000 U) intra-pleural injection(referred to as "position plus 2.0").The success rate of the "position plus 2.0" intervention was 16/17, and the recurrence rate was 3/17. There were four cases of fever, four cases of pleural effusion, one case of empyema, and no other adverse reactions. This study has shown that the "position plus 2.0" intervention is safe, effective, and simple for patient with persistent air leakage failed to intervention with"position plus 1.0" after thoracoscopic treatment of pulmonary and pleural diseases related to bulla.

[Effectiveness and safety of medical glue assisted argon plasma coagulation union giant emphysematous bulla volume reduction via thoracoscope on the treatment of spontaneous pneumothorax with subpleural bullae]

Objective: To evaluate the effectiveness and safety of a new treatment protocol that combined "medical glue assisted argon plasma coagulation"(hereinafter called "APC plus") and "giant emphysematous bulla volume reduction"(hereinafter called "one thoracoscope plus one needle") via medical thoracoscopy on the spontaneous pneumothorax patients whose chest high resolution CT (HRCT) showed multiple subpleural bullae (SPB) and at least one SPB≥4 cm in diameter. Methods: A retrospective analysis was performed on the clinical data of 46 cases of spontaneous pneumothorax with multiple SPB(at least one SPB≥4 cm in diameter), 42 males and 4 females, aged from 31 to 79 (68.5±10.3) years,from June 2018 to December 2021 in Rizhao Hospital of Traditional Chinese Medicine. The time of air leakage discontinuance, the disappearance rate and reduction degree of target subpleural blebs one week after operation, the degree of reduction and the incidence of postoperative complications were observed. Two-year follow-up after operation was carried out to assess the recurrence rate and its short- and long-term complications. Results: Among the 46 patients, SPB disappeared or nearly disappeared in 39 cases (84.78%), decreased in number or reduced in volume in 5 cases (10.87%), and remained unchanged in 2 cases (4.35%) after the intervention of "APC Plus"; 40 patients stopped leaking within 1 week and 6 cases stopped leaking over a week. Eleven patients finished the 3-year follow-up, 13 finished 2-year follow-up and 6 finished 1-year follow-up, with only 1 relapse. No serious complications occurred in all these 46 patients. Conclusion: "APC plus" combining with "one thoracoscope plus one needle" is safe and effective in the treatment of pneumothorax patients with multiple subpleural bullae of varying sizes.

[Efficacy and safety of position selection combined with intra-pleural thrombin injection in the treatment of postoperative persistent air leakage in bullous pulmonary-pleural diseases]

Objective: To explore the efficacy and safety of position selection in combination with intra-pleural thrombin injection in the treatment of persistent air leakage (PAL) after medical thoracoscopic treatment of bullous pulmonary-pleural diseases (e.g. spontaneous pneumothorax or giant emphysematous bulla). Methods: This was a prospective study conducted in Rizhao Hospital of Traditional Chinese Medicine from August 2018 to November 2020. Twenty patients(19 males,1 female) with a mean age of (62.3±8.1) years met the diagnostic criteria for PAL which was defined as the air leak persisted more than 3 days despite of the closed thoracic drainage after medical thoracoscopic treatment of bullous pulmonary-pleural diseases.They received the following treatment procedures (referred to as "position plus"):①Pleural cavity injection (50% glucose 20 ml+thrombin 5 000 U).②Changing the patient's position under continuous negative pressure suction to find the position causing the complete stop or significant reduction of air leakage, and keeping in the position for 24-48 hours.③If the PAL wasn't stopped 48 hours later, the procedures above would be repeated.The duration of air leakage after "position plus", times of pleural cavity injection, condition of lung re-expansion, recurrence of air leakage and complications during hospitalization were recorded. Descriptive statistics were used to summarize the results:¯x±s or M(P₂₅, P₇₅) for continuous variables; frequency and percentages for categoric variables. Results: A total of 20 patients were included. The average duration of air leakage after"position plus" was (1.32±0.97) days. The times of pleural cavity injection required were 1.0(1.0, 1.0).All the patients showed good lung re-expansion in review of imaging after PAL was stopped. One patient had recurrent air leakage during hospitalization. No serious complications occurred. Conclusion: The comprehensive "position plus" intervention method is effective, safe and easily operating for the treatment of PAL after medical thoracoscopic treatment of bullous pulmonary-pleural diseases.

[Cytokine profiles of CD4(+) T memory cells in asthma and their relationship with asthma severity]

Objective: To study the phenotype of memory CD4(+) T cells in peripheral blood of asthmatics and its relationship with asthma severity. Methods: From Dec 2014 to Aug 2015, thirty-three asthmatics, twenty-six chronic obstructive pulmonary disease (COPD) patients and twenty-two healthy volunteers were enrolled in Respiratory Clinics of Zhongshan Hospital, Fudan University. Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood. Cell surface markers (CD45RO, CRTH2, CD62L, and CCR7) and intracellular protein[interleukin (IL)-5, IL-17, interferon (IFN)-γ]staining was performed using flow-cytometric techniques. CD4(+) T cells were cultured under neutralization and then Th2, Th2+ Lipopolysaccharide (LPS), Th2+ Home dust mite (HDM) conditions for 6 days and then intracellular proteins were analyzed using flow cytometry. Correlation analysis between memory CD4(+) T cells, asthma severity and drug consumption were performed. Results: The percentage of memory CD4(+) T (CD4(+) Tm) cells in circulating white blood cells was higher in asthmatics, than that in healthy subjects (48.0%±5.7% vs 32.0%±4.1%, P<0.05). The cytokine profiles of CD4(+) Tm cells in asthma patients were substantially different from those of COPD and healthy subjects, with increased IL-5 and IL-17 production. For COPD patients, the predominant cytokines were IFN-γ instead. IL-17-producing CD4(+) Tm cells were associated with the severity of disease and the level of medication consumption in asthma patients (R(2)=0.829 6, P<0.05). Conclusions: The cytokine profile is IL-5 and IL-17 predominant in memory CD4(+) T cells from asthmatics. The amount of IL-17(+) CD4(+) memory T cells is positively correlated with asthma severity.

Increased lymphocyte sister chromatid exchange frequency in workers with exposure to low level of ethylene dichloride

The genotoxicity of low-level exposure to ethylene dichloride (EDC) and vinyl chloride monomer (VCM) in humans is not clear. We used lymphocyte sister chromatid exchange (SCE) frequency as a parameter to investigate the genotoxicity of low level EDC and VCM in VCM-manufacturing workers. The SCE frequency was determined for 51 male workers with exposure to VCM and/or EDC and for 20 male workers devoid of such exposure. Epidemiological data were obtained by questionnaire, and included history of smoking, drinking, and any medication taken, as well as a detailed occupational history. Personal- and area-sampling and analysis were conducted in order to calculate the time-weighted average (TWA) contaminant-exposure level corresponding to different job categories. Moderate EDC exposure around 1 ppm corresponded to a significantly greater SCE frequency than was the case for the low EDC exposure group (p<0.01). However, VCM exposure of similar level was not associated with increased SCE. We conclude that EDC may cause genotoxicity at a relatively low level of exposure.

Abnormal liver function in workers exposed to low levels of ethylene dichloride and vinyl chloride monomer

We investigated whether exposure to ethylene dichloride (EDC) and vinyl chloride monomer (VCM) resulted in increased risk of liver damage. Epidemiological information, including occupational, medical, smoking, and drinking history, was obtained by interview from 251 male workers. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) were used as indicators of liver damage. Exposure to moderate or low levels of ECD and VCM resulted in a higher risk of developing abnormal ALT levels than did exposure to lower levels of the chemicals. Results were similar for AST. GGT was not associated with EDC or VCM exposure. Combined exposure to EDC and VCM showed a dose-response relationship in association with abnormal ALT levels. We concluded that relatively low concentrations of VCM and EDC cause liver damage.

A registry-based case-control study of risk factors for the development of multiple non-fatal injuries on the job

Using compensation records of Taiwan, we conducted a case-control study nested within a cohort of 77,846 active workers who experienced at least one incidence of non-fatal work-related injury between 1994 and 1996 in order to explore factors associated with risk of sustaining multiple non-fatal injuries in the workplace. Cases (n = 2,616) were workers with more than three incidences of non-fatal injury during the study period and controls (n = 3,974) were randomly sampled from workers who experienced only one incidence of non-fatal injury during the same period. Compared with construction workers, workers employed in mining and quarrying (OR = 2.7), manufacturing (OR = 1.2), commerce (OR = 1.6), transport, storage and communication (OR = 1.3) and social, personal and community service (OR = 1.4) were all at significantly elevated risk of multiple non-fatal injuries. Both age and wage showed a significant dose-response effect on the risk of developing multiple non-fatal injuries. The preliminary analysis suggests that workers in certain industries are at significantly elevated risks of multiple work-related non-fatal injuries, in particular those in the mining and quarry industries. Additionally, further preventive measures should be aimed at protecting older workers from such injuries and further studies would help provide more specific interpretations on the positive association between higher wage earning and risk of multiple non-fatal injuries.

Plasma p53 protein and anti-p53 antibody expression in vinyl chloride monomer workers in Taiwan

Vinyl chloride (VC) workers are known to be at risk for development of angiosarcoma of the liver (ASL), a rare tumor. Previously, a study of p53 gene mutations in tumors of VC-exposed workers found that 50% of liver angiosarcomas contained such mutations. Mutant p53 oncoprotein and anti-p53 antibodies can also be found in the sera of ASL patients and VC-exposed workers without cancer. Workers in Taiwan have also been exposed to VC, and some have contracted liver tumors. In this study, we used enzyme-linked immunosorbent assays to detect mutant p53 protein and anti-p53 antibodies in the plasma of VC-exposed workers in Taiwan. Thirty-three of 251 (13.2%) VC-workers tested positive for the p53 overexpression (10% with positive mutant p53 protein and 3.6% with positive anti-p53) in their plasma, but only 2 of 36 controls (5.6%) tested positive (2.8% with positive mutant p53 protein and 2.8% with positive anti-p53). There was a significant association between cumulative VC exposure concentration and positive p53 expression (P = 0.032) among VC workers after we adjusted for age, hepatitis, drinking, and smoking status. In summary, P53 overexpression (mutant p53 protein or anti-p53 antibody) can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma p53 overexpression and VC cumulative exposure concentration.

Effects on sister chromatid exchange frequency of aldehyde dehydrogenase 2 genotype and smoking in vinyl chloride workers

Vinyl chloride monomer (VCM) is a human carcinogen. However, the exact mechanism of carcinogenesis remains unclear. VCM may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferases (GSTs). Thus workers with inherited variant metabolic enzyme activities may have an altered risk of genotoxicity. This study was designed to investigate which risk factors might affect sister chromatid exchange (SCE) frequency in polyvinyl chloride (PVC) workers. Study subjects were 44 male workers from three PVC factories. Questionnaires were administered to obtain detailed histories of cigarette smoking, alcohol consumption, occupations, and medications. SCE frequency in peripheral lymphocytes was determined using a standardized method, and CYP2E1, GSTM1, GSTT1 and ALDH2 genotypes were identified by the polymerase chain reaction (PCR). Analysis revealed that smoking status and exposure to VCM were significantly associated with increased SCE frequency. The presence of ALDH2 1-2/2-2 genotypes was also significantly associated with an elevation of SCE frequency (9. 5 vs. 8.1, p<0.01). However, CYP2E1, GSTM1 or GSTT1 genotypes were not significantly associated with SCE frequency. When various genotypes were considered together, combination of CYP2E1 c1c2/c2c2 with ALDH2 1-2/2-2 showed an additive effect on SCE frequency. Similar results were also found for the combination of smoking with CYP2E1, or smoking with ALDH2. These results suggest that VCM workers with ALDH2 1-2/2-2 genotypes, who also smoke, may have increased risk of DNA damage.

Plasma Asp13-Ki-ras oncoprotein expression in vinyl chloride monomer workers in Taiwan

Vinyl chloride (VC) workers are known to be at risk for development of liver angiosarcoma, a rare tumor. Previously, more than 80% of VC workers with liver angiosarcoma have been found to have an Asp-13 c-Ki-ras oncogene mutation, and more than 50% of VC-exposed workers without liver tumors were found to have Asp13-Ki-ras oncoprotein in their plasma. Some workers in Taiwan had also been exposed to VC, and some have contracted liver tumors. In this study, we used enhanced chemiluminescence Western blotting to detect Asp13-p21-Ki-ras in the sera of VC-exposed workers in Taiwan. There were 14 of 113 (12.4%) VC workers positive for the Asp13-Ki-ras oncoprotein in plasma, but 0 of 18 controls were positive. There were 10 of 69 (14.5%) plasma-positives among the more highly exposed (> 1000 ppm-months) workers and 4 of 48 (9.1%) plasma-positives among the lesser exposed (< or = 1000 ppm-months). Compared with the unexposed controls, the odds ratios (and 95% confidence intervals [CI]) for plasma-positivity were 4.11 (95% CI = 0.21, 80.4) in the lower-exposed workers and 6.53 (95% CI = 0.37, 116.9) in the higher-exposed workers, and there was a linear trend between exposure and plasma-positivity (P = 0.073). After adjusting for age and drinking status, the odds ratios (and 95% CIs) were 1.64 (95% CI = 0.17, 15.8), and 2.65 (95% CI = 0.42, 16.8), respectively, and there was a significant linear trend between exposure and plasma-positivity (P = 0.048). In summary, Asp13-Ki-ras oncoprotein can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma oncoprotein expression and VC exposure.

Increased morbidity odds ratio of primary liver cancer and cirrhosis of the liver among vinyl chloride monomer workers

OBJECTIVES

To determine if there is an increased risk of admission to hospital for various diseases among vinyl chloride monomer (VCM) workers.

METHODS

2224 workers with occupational exposure to VCM were identified for occurrence of disease based on a search of hospital computer files on labour insurance. These data were compared with those of workers manufacturing optical equipment and motorcycles from 1 January 1985 to 31 March 1994. Cardiovascular and cerebrovascular diseases were used as reference diseases, and the age adjusted morbidity odds ratio (MOR) was calculated.

RESULTS

A significantly increased risk of admission to hospital among VCM workers due to primary liver cancer (MOR 4.5-6.5), cirrhosis of the liver (MOR 1.7-2.1), and other chronic diseases (MOR 1.5-2.0) was found. There were eight cases of primary liver cancer, all with heavy previous exposure to VCM. Another four cases of hepatoma in polyvinyl chloride (PVC) workers were found in the death registry. Ten out of 11 cases of hepatoma, with detailed medical information, were carriers of hepatitis B virus. The average latent period (20 years) was not different from other studies. Alternative agents of primary liver cancer were largely ruled out, suggesting that the combination of hepatitis B and VCM may lead to primary liver cancer.

CONCLUSION

There is an increased risk of primary liver cancer in workers exposed to VCM, although the incomplete coverage of the Labor Insurance Bureau data warrants cautious interpretation of the results. Further study exploring the synergistic effects of VCM and hepatitis B is also indicated.

Changes in lymphocyte single strand breakage and liver function of workers exposed to vinyl chloride monomer

Vinyl chloride monomer (VCM) is a suspected human carcinogen. Its metabolite, chloroethylene epoxide, is able to alkylate the DNA molecule and to produce single strand breakage (SSB). A total of 244 workers from 4 polyvinyl chloride (PVC) manufacturing factories were recruited to assess the SSB of their peripheral lymphocyte DNA. The method of alkaline unwinding and hydroxyapatite chromatography was used to detect and calculate frequencies of SSB. In addition, hepatitis B and C markers and the liver function of the workers were also examined. The worker's cumulative exposures to VCM were retrospectively constructed from the current monitoring data and each worker's job history. Multiple linear regression models were constructed to predict the worker's level of SSB and liver functions based on various exposure indices and variables, such as age, sex, smoking, drinking, and hepatitis markers. The results showed that current smoking and drinking status, and the presence of VCM exposures on the previous day were 3 major determinants of the level of SSB. Among the liver function tests, only gamma-glutamyl transpeptidase (GGT) was associated with current VCM exposures. In contrast, aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were mainly affected by the presence of hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (anti-HCV). We conclude that GGT should be considered to be included in the regular health screening of VCM workers, and that the SSB method may not be suitable for long-term monitoring of cumulative exposure because of the quick DNA repair mechanism in humans.