Objective To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on oxidative stress damage in rat lung tissue. Methods SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups,the rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage.To observe the ultrastructural and histopathology changes of lung tissue in rats.The levels of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in lung tissue were detected. The ultrastructural and histopathological changes were examined. The expression levels of HO-1 mRNA and protein were detected by Real-time PCR and Western Blot, respectively. Results The body mass, lung tissue mass, and lung organ coefficient of rats in each dose group were lower than those in the control group (P<0.05), and the body mass of rats in each group increased with the increase of exposure time (P<0.05); The results of lung histopathological examination showed that after TDI exposure,in the high-dose group, pulmonary alveolar wall hyperemia and edema were observed in the lung tissue of rats, alveolar wall thickening was observed, alveolar septa widening, and a large number of red blood cells were seen in the alveolar cavity. The results of ultrastructural examination of lung tissue showed that after TDI exposure, while in the high-dose group, the number of alveolar cells decreased, with unclear cell boundaries and irregular morphology. The levels of MDA in the lung tissue of rats exposed to TDI at various doses were higher than those in the control group (P<0.05), while the levels of GSH, GSH-Px, SOD, and CAT were lower than those in the control group (P<0.05); There was no significant difference in HO-1 gene and protein levels among rats in each group (P>0.05). Conclusion Subchronic inhalation of TDI can cause changes in the pathology and ultrastructure of rat lung tissue, leading to abnormal levels of metabolic enzymes in lung function, thereby inducing oxidative stress damage to the lungs. However, but HO-1 is involved in oxidative stress damage in the lungs induced by TDI.

Objective:To observe any effect of cooling on the amplitude of vibration-induced sensory nerve action potentials (SNAPs) in human digits.Methods:The middle fingers of 15 healthy adults were either cooled to about 22℃ using an ice pack or kept at about 32℃. A vibrator was applied to the joint connecting the middle finger and the palm vibrating with an amplitude of 2mm at a frequency of 60Hz. The amplitudes of middle finger SNAPs before, during and right after the vibration were recorded.Results:The SNAP amplitude at a given temperature was lower during vibration than before it, but it immediately returned to the pre-vibration level after the vibration ceased. The middle finger SNAP amplitudes at 22℃ were significantly higher than those at 32℃ throughout. The decrease in amplitude at 32℃ (61.7±15.1%) was significantly greater than that at 22℃ (24.1±7.0%).Conclusions:Cooling significantly reduces the effect of vibration on the amplitude of digital SNAPs. That suggests a way to protect the sensory nerves in hand-arm vibration syndrome.

Objective To analyze the applicability of different risk assessment methods in assessing laboratory benzenes exposure. Methods The work positions exposed to benzenes (benzene, toluene, xylenes) of a chemical catalyst research and development company were selected as the research subjects. An occupational health field survey was conducted, and the benzenes exposure levels of the lab personnel were measured. Qualitative assessment method, comprehensive index method, quantitative assessment method, and occupational hazards classification method were used to evaluate the occupational health risk on benzenes exposure in the laboratory personnel. The applicability of different assessment methods was compared. Results The occupational health engineering protection measures and management system of the company need to be further implemented. The benzene exposure level of benzene hydrogenation laboratory personnel exceeded the national standard, with the exposure concentration of time weighted average (C_TWA) of 5.00 mg/m³ and short term exposure concentration (C_STE) of 10.50 mg/m³. The C_TWA and C_STE of toluene and xylenes exposure were both lower than the minimum quantitative concentrations. The results of different risk assessment methods varied. The qualitative assessment method indicated higher level of occupational health risk of benzenes, while the comprehensive index and hazard classification methods indicated consistent result on lower level of benzenes. For occupational health risk of benzene, the standardized risk ratio (RR) levels corresponding to the qualitative and quantitative assessment methods were both extremely high risk. The RR levels of benzene exposure assessment using the comprehensive index method and the occupational hazards classification method were high, while the corresponding RR levels of exposure to toluene and xylenes were both low. Conclusion Attention should be paid on the health risks of benzene exposure to benzene hydrogenation laboratory personnel. When benzene exposure level is below the national occupational exposure limit, occupational hazards classification method is not recommended for health risk assessment for benzenes. The comprehensive index method is preferable when more comprehensive occupational health information is available, as it provides a more objective and comprehensive evaluation on occupational health risks of benzenes.

AIM:To investigate the impact of honokiol(HKL),an activator of silent information regulator 3(SIRT3),on postoperative cognitive dysfunction(POCD)in mice,and to explore the potential mechanisms.METHODS:Ten-month-old male C57/BL6 mice were randomly divided into control(Con)group,surgical(Sur)group and Sur+HKL group(n=10).The mice in Sur+HKL group were intraperitoneally injected with HKL for 7 d before modeling.The mice in Sur and Sur+HKL groups underwent tibial fracture open reduction and internal fixation to establish the POCD model.The assessment of cognitive function was conducted using the open-field test(OFT),novel object recognition test(NORT),Morris water maze test(MWMT),and Y-maze test(YMT).Nissl staining was employed to assess the morphology,struc-ture and vitality of hippocampal and cortical neurons in mice.The protein expression of glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),acyl coenzyme A synthetase long-chain family member 4(ACSL4),SIRT3 and nuclear factor E2-related factor 2(NRF2)in the mouse hippocampus was detected by Western blot,while im-munofluorescence staining was utilized to determine GPX4 level in mouse neurons.RESULTS:No statistically signifi-cant differences were observed among the groups in terms of total distance moved and central zone exploration during the OFT(P>0.05).However,the results from the NORT and YMT indicated that the mice in Sur group exhibited significant-ly lower recognition indexes,reduced alternation rates(P<0.01),and decreased percentages of entries and crossing time into the new arm after side arm blockade(P<0.01),when compared with Con group.Furthermore,the mice in Sur group demonstrated a slower decrease in latency during the learning period of MWMT,while significantly lower latency,fewer crossing number and lower percentage of time in the target quadrant were observed during the testing period of MWMT(P<0.01).The above indicators were obviously enhanced in Sur+HKL group compared with Sur group(P<0.01).The results of Nissl staining indicated lighter neuronal staining in the hippocampal CA1 region and medial prefrontal cortex in Sur group,accompanied by a significant reduction in the number of Nissl-stained positive neurons(P<0.01).Notably,HKL pretreatment demonstrated a significant improvement in neuronal vitality.Analysis of Western blot revealed that compared with Con group,the expression of SIRT3,GPX4,SLC7A11 and NRF2 in Sur group was significantly reduced,while the expression of ACSL4 was significantly increased(P<0.05).However,these alterations were reversed after treatment with HKL(P<0.05).Immunofluorescence staining of hippocampal neurons corroborated the findings from Western blot analy-sis,demonstrating a notable decrease in GPX4 expression in hippocampal neurons of Sur group,which was significantly restored after HKL pretreatment(P<0.01).CONCLUSION:Treatment with HKL attenuates POCD in mice,potentially through its inhibitory effect on hippocampal neuronal ferroptosis.

Objective To investigate the expression of Midkine(MDK)in cholangiocarcinoma(CCA)and its value in predicting the prognosis of CCA,as well as the potential mechanism of the effect of MDK on the progression of CCA.Methods The data of CCA samples were obtained from TCGA database to analyze the difference in the expression of MDK between cancer tissue and paracancerous tissue and its association with clinical features,and the data collected from GEO database and 11 CCA patients who underwent surgical resection in The Fifth Medical Center of Chinese PLA General Hospital from June 2018 to September 2021 were used for validation.STRING and Cytoscape were used to construct a protein-protein interaction network,and gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were used to investigate the biological functions and tumor-related pathways involving MDK-related genes.In addition,TIMER and TISIDB databases were used to analyze the correlation between MDK expression and immune cell infiltration in CCA tissue.The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups,and the Fisher's exact test was used for comparison of categorical data between two groups.The Kaplan-Meier method was used to plot survival curves,and the Log-rank test was used for comparison between groups.The Spearman correlation analysis was used to investigate the correlation between two variables.Results The expression level of MDK in cancer tissue and paracancerous tissue of CCA patients was compared based on TCGA database,and the results of the non-paired and paired analyses showed that the expression level of MDK in CCA tumor tissue was significantly higher than that in paracancerous tissue(P<0.001).Transcriptome sequencing was performed for the tumor tissue and its corresponding paracancerous tissue from 11 CCA patients,and the results showed that the expression level of MDK in CCA tumor tissue was significantly higher than that in corresponding paracancerous tissue(P<0.01).High expression of MDK was associated with lymph node metastasis(P=0.045)and vascular invasion(P=0.044).Survival analysis showed that compared with the CCA patients with low MDK expression,the CCA patients with high MDK expression had significantly shorter overall survival time(χ2=5.30,P=0.028)and disease-specific survival time(χ2=6.25,P=0.019).The GO and KEGG enrichment analyses showed that the 30 MDK-related genes were closely associated with ubiquitin-mediated proteolysis and affected the prognosis of CCA patients.The TIMER analysis showed that the expression level of MDK was positively correlated with the infiltration of B cells(r=0.356,P=0.035 6)and dendritic cells(r=0.409,P=0.014 7)in tumor microenvironment of CCA;the TISIDB analysis showed that the expression level of MDK was positively correlated with CXCL16(r=0.465,P=0.004 67)and was negatively correlated with CXCL12(r=-0.389,P=0.019 7)and CXCR5(r=-0.393,P=0.018 5),and it was also negatively correlated with the immune checkpoint regulators VTCN1(r=-0.393,P=0.018 3),LTA(r=-0.380,P=0.022 7),and PVR(r=-0.350,P=0.037 3).Conclusion High expression of MDK is associated with poor prognosis in CCA patients,and MDK has the potential of being used as a molecular marker for predicting the prognosis of CCA.MDK may promote the development and progression of CCA by regulating ubiquitin-mediated proteolysis and the infiltration of B cells and dendritic cells.

Objective:To analyze the risk factors for aspiration pneumonia (AP) among stroke survivors with dysphagia and construct a prediction model.Methods:The records of one hundred and forty-eight stroke survivors with dysphagia admitted since 2021 were retrospectively analyzed. They were divided into an AP group ( n=46) and a non-AP group ( n=102). Univariate and multivariate logistic regressions were evaluated seeking independent risk factors for AP. the receiver-operating characteristic (ROC) curves were used to analyze predictive power. Results:The incidence of AP was 31%. Multivariate logistic regression analysis showed that age, Barthel index, Kubota′s water drinking test grading, nutritional support methods and the neutrophil/lymphocyte ratio (NLR) could be useful independent predictors of AP. The areas under the ROC curves suggested that Kubota grading, nutritional support methods, the NLR and the Barthel index could be used to prepare a prediction nomogram with good sensitivity and specificity.Conclusions:Age, Barthel index, Kubota water drinking test grades, nutritional support methods and NLR are independent predictors of AP for stroke survivors with dysphagia. Combining them in a nomogram gives better predictive power than using the factors alone.

Objective:To seek a correlation between short-chain fatty acids (SCFAs) and skill in the activities of daily living (ADL) after an ischemic stroke.Methods:Ninety ischemic stroke survivors were assessed using the Barthel Index (BI). Fecal samples were collected and analyzed for the concentration of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid using gas chromatography. Spearman correlation analysis was conducted to identify SCFAs that correlated with the total BI score. Linear regressions were evaluated to explore the correlation between the total BI score and SCFAs.Results:The concentrations of propionic and butyric acids in the feces were found to correlate significantly with the total BI scores. Data including propionic acid and butyric acid levels, age, gender, body mass index, disease duration, any history of hypertension or diabetes, and other SCFAs were included in the regression models. Propionic and butyric acid levels were found to be potentially useful predictors of total BI scores.Conclusions:The concentration of propionic and butyric acids in the feces after an ischemic stroke can predict the survivor′s total BI score. Those concentrations could therefore be useful for predicting ADL ability.

Objective To analyze the diagnosis cases of occupational benzene poisoning in gas station industry, and to explore the application of GC-MS technology in occupational disease diagnosis.   Methods The epidemiological method was used to describe and analyze the occupational disease diagnosis of 15 gas station workers , and qualitative screening of occupational hazard factors was performed by GC-MS.   Results All the 15 workers had more than one year's occupation history of oil refueling and unloading.  The clinical manifestations were consistent with the characteristics of chronic benzene poisoning in diagnosis of occupational benzene poisoning.  However, due to lack of evidence of occupational exposure to benzene and incomplete diagnostic data, occupational chronic benzene poisoning was not diagnosed. GC-MS technology was used to screen the occupational hazard factors in the gas station workplace, and benzene, n-pentane, n-hexane and so on were found.  Conclusion GC-MS is recommended for qualitative screening of organic solvents such as benzene when diagnosing occupational diseases for gas station workers , so as to accurately identify occupational hazard factors in workplaces and provide reliable basis for diagnosis of occupational diseases.

Objective To understand the occurrence characteristics of occupational chemical incidents in China by media surveillance, to provide scientific evidences for formulating effective prevention and control strategies, and to provide new ideas for public surveillance and early warning of chemical incidents. Methods Occupational chemical incidents were collected and sorted through the Internet every day. The statistical analysis was conducted from time, region, industry, and causes of the collected incidents. Results A total of 99 occupational chemical incidents were collected in 2021, involving 356 peoples and 186 deaths. April to July was the high incidence period of events, mainly limited space poisoning and asphyxiation events. Majority of the incidents were general grade events, mainly occurring in small and medium enterprises. Guangdong Province had the most incident reporting areas. Incidents mainly occurred in chemical raw material and chemical product manufacturing industry as well as in water production and supply industry, mainly in manufacturing, cleaning and maintenance positions. The main types of poisons were asphyxiating gases and organic solvents, mainly involving hydrogen sulfide and benzene. The incidents could have been caused by lack of safety awareness, leakage of equipment, and lack of protective measures. Conclusion Occupational chemical incidents still occur frequently and cause serious harm. It is suggested that the relevant departments and employers should strengthen supervision and management, effectively manage and control operational risks, and increase supervision of key industries and positions, to ensure the health and safety of workers.

Objective To understand the occupational health status of gas station workers, to analyze the characteristics of early health damage, and to provide a reference for the occupational health monitoring of workers in this industry. Methods The gas station workers who underwent occupational health examination in an occupational health examination institution in Tianjin in 2021were selected as the research subjects. The examination results were statistically analyzed. Results A total of 381 gas station workers were included in this study, with a sex ratio of male to female of 1.40:1. The top three tests with abnormal results from high to low were abdominal color Doppler ultrasound (39.63%), urine routine (29.13%), and blood pressure (23.62%). The detected fatty liver accounted for 74.83% of abnormal abdominal color Doppler ultrasound. Analysis of abnormal results of different genders showed that the detection rate of abnormal blood pressure, fatty liver and liver function in males was higher than that in females (χ²=16.40, 25.40, 15.98，P＜0.05), the detection rate of high GGT in males was significantly higher than that in females (χ²=16.04，P＜0.05）. The detection rate of abnormal urine routine in females was higher than that in males (χ²=12.85，P＜0.05), and the positive rate of urine white blood cells and blood in urine were significantly higher I women than those in men (χ² =16.80, 11.66，P＜0.05). The abnormal detection rate of electrocardiogram of gas station workers increased with age (χ²=28.02，P＜0.05), and the abnormality of high blood pressure showed an increasing trend with age and working years（χ²=25.00, 15.26，P＜0.05). Conclusion The long-term exposure of gas station workers to chemical toxic substances such as organic solvents and benzene series and physical factors such as high temperature in summer and low temperature in winter will have a certain impact on health. It is suggested that employers should reasonably arrange their work systems and carry out occupational health monitoring in a targeted manner.