The mitochondria-targeted antioxidant MitoQ ameliorates inorganic arsenic-induced DCs/Th1/Th2/Th17/Treg differentiation partially by activating PINK1-mediated mitophagy in murine liver

Inorganic arsenic is a well-established environmental toxicant linked to acute liver injury, fibrosis, and cancer. While oxidative stress, pyroptosis, and ferroptosis are known contributors, the role of PTEN-induced kinase 1 (PINK1)-mediated mitophagy in arsenic-induced hepatic immunotoxicity remains underexplored. Our study revealed that acute arsenic exposure prompts differentiation of hepatic dendritic cells (DCs) and T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cells, alongside increased transcription factors and cytokines. Inorganic arsenic triggered liver redox imbalance, leading to elevated alanine transaminase (ALT), hydrogen peroxide (H2O2), malondialdehyde (MDA), and activation of nuclear factor erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1) pathway. PINK1-mediated mitophagy was initiated, and its inhibition exacerbates H2O2 accumulation while promoting DCs/Th1/Th2/Treg differentiation in the liver of arsenic-exposed mice. Mitoquinone (MitoQ) pretreatment relieved arsenic-induced acute liver injury and immune imbalance by activating Nrf2/HO-1 and PINK1-mediated mitophagy. To our knowledge, this is the first report identifying PINK1-mediated mitophagy as a protective factor against inorganic arsenic-induced hepatic DCs/Th1/Th2 differentiation. This study has provided new insights on the immunotoxicity of inorganic arsenic and established a foundation for exploring preventive and therapeutic strategies targeting PINK1-mediated mitophagy in acute liver injury. Consequently, the application of mitochondrial antioxidant MitoQ may offer a promising treatment for the metalloid-induced acute liver injury.

A Differential Protein Study on Bronchoalveolar Lavage Fluid at Different Stages of Silicosis

OBJECTIVES

In this study, by comparing the difference in protein expression in bronchoalveolar lavage fluid between silicosis patients in different stages and healthy controls, the pathogenesis of pneumoconiosis was discussed, and a new idea for the prevention and treatment of pneumoconiosis was provided.

METHODS

The lung lavage fluid was pretreated by 10 K ultrafiltration tube, Agilent 1100 conventional liquid phase separation, strong cation exchange column (SCX) HPLC pre-separation, and C18 reverse phase chromatography desalting purification, and protein was labeled with isotope. GO, KEGG pathway, and PPI analysis of differential proteins were conducted by bioinformatics, and protein types and corresponding signal pathways were obtained.

RESULTS

Thermo Q-Exactive mass spectrometry identified 943 proteins. T-test analysis was used to evaluate the different significance of the results, and the different protein of each group was obtained by screening with the Ratio≥1.2 or Ratio≤0.83 and P<0.05. We found that there are 16 kinds of protein throughout the process of silicosis. There are different expressions of protein in stages Ⅲ/control, stages Ⅱ/control, stage Ⅰ/control, stages Ⅲ/ stages Ⅱ, stages Ⅲ/ stage Ⅰ and stages Ⅱ/ stage Ⅰ groups. The results of ontology enrichment analysis of total differential protein genes show that KEGG pathway enrichment analysis of differential protein suggested that there were nine pathways related to silicosis.

CONCLUSION

The main biological changes in the early stage of silicosis are glycolysis or gluconeogenesis, autoimmunity, carbon metabolism, phagocytosis, etc., and microfibril-associated glycoprotein 4 may be involved in the early stage of silicosis. The main biological changes in the late stage of silicosis are autoimmunity, intercellular adhesion, etc. Calcium hippocampus binding protein may participate in the biological changes in the late stage of silicosis. It provides a new idea to understand the pathogenesis of silicosis and also raises new questions for follow-up research.

[Application of a light-weighted convolutional neural network for automatic recognition of coal workers' pneumoconiosis in the early stage]

Objective: To construct and verify a light-weighted convolutional neural network (CNN), and explore its application value for screening the early stage (subcategory 0/1 and stage Ⅰ of pneumoconiosis) of coal workers' pneumoconiosis (CWP) from digital chest radiography (DR) . Methods: A total of 1225 DR images of coal workers who were examined at an Occupational Disease Prevention and Control Institute in Anhui Province from October 2018 to March 2021 were retrospectively collected. All DR images were collectively diagnosed by 3 radiologists with diagnostic qualifications and gave diagnostic results. There were 692 DR images with small opacity profusion 0/- or 0/0 and 533 DR images with small opacity profusion 0/1 to stage Ⅲ of pneumoconiosis. The original chest radiographs were preprocessed differently to generate four datasets, namely 16-bit grayscale original image set (Origin16), 8-bit grayscale original image set (Origin 8), 16-bit grayscale histogram equalized image set (HE16) and 8-bit grayscale histogram equalized image set (HE8). The light-weighted CNN, ShuffleNet, was applied to train the generated prediction model on the four datasets separately. The performance of the four models for pneumoconiosis prediction was evaluated on a test set containing 130 DR images using measures such as the receiver operating characteristic (ROC) curve, accuracy, sensitivity, specificity, and Youden index. The Kappa consistency test was used to compare the agreement between the model predictions and the physician diagnosed pneumoconiosis results. Results: Origin16 model achieved the highest ROC area under the curve (AUC=0.958), accuracy (92.3%), specificity (92.9%), and Youden index (0.8452) for predicting pneumoconiosis, with a sensitivity of 91.7%. And the highest consistency between identification and physician diagnosis was observed for Origin16 model (Kappa value was 0.845, 95%CI: 0.753-0.937, P<0.001). HE16 model had the highest sensitivity (98.3%) . Conclusion: The light-weighted CNN ShuffleNet model can efficiently identify the early stages of CWP, and its application in the early screening of CWP can effectively improve physicians' work efficiency.

[Effects of heat exposure and vitamin C intervention on oxidative stress and blood pressure changes in treadmill rats]

Objective: To investigate the effect of oxidative stress caused by heat exposure on the blood pressure increase of treadmill rats and the intervention of antioxidants. Methods: In June 2021, Twenty-four healthy SD male rats were randomly divided into four groups: normal temperature feeding, normal temperature treadmill, high temperature treadmill and high temperature treadmill supplementation with vitamin C groups, 6 rats in each group. The rats run on the platform in normal temperature or heat exposure environment for 30 min in the morning and in the afternoon daily, 6 days per week. The daily vitamin C supplement dose of high temperature treadmill supplementation with vitamin C group was 10 mg/kg. BP recordings were done at the end of the week. The rat vascular lipofuscin (LF) was detected by ELISA, the rat serum nitric oxide (NO) was detected by nitrate reductase method, the serum malondialdehyde (MDA) was detected by thibabituric acid method, the serum glutathione peroxidase (GPx) and superoxide dismutase (SOD) were detected by chemiluminescence method, and the serum catalase (CAT) was detected by ammonium molybdate method. The total antioxidant capacity (T-AOC) of serum was measured by iron reduction/antioxidant capacity method, and the content of nuclear erythroid 2-related factor 2 (Nrf2) in vascular tissue was measured by Western blot. The intra-group mean was compared by repeated measurement analysis of variance, and the inter-group mean was compared by single-factor analysis of variance and post-event LSD-t test. Results: Compared with the previous time point, the systolic BP and diastolic BP of the high temperature treadmill group were significantly increased at 7, 14 and 21 d, and decreased at 28 d which were higher than the initial level (P<0.05), and the systolic BP and diastolic BP values at each experimental time point were significantly higher than those of normal temperature treadmill group (P<0.001). The changes of thickening of the artery wall, no smoothing of the endodermis and irregular arrangement of muscle cells in high temperature treadmill group were observed. Compared with the normal temperature treadmill group, the content of MDA in serum, and LF in vascular tissue were significantly increased, the activities of SOD, CAT, T-AOC, the content of NO in serum, and the expression of Nrf2 in vascular tissue were significantly decreased in high temperature treadmill group (P<0.05). Compared with the high temperature treadmill group, the systolic BP and diastolic BP values at 7, 14, 21 and 28 d, the content of serum MDA and LF in vascular tissue were significantly decreased, the activities of CAT and T-AOC, and the expression of Nrf2 in vascular tissue significantly increased (P<0.05), the histopathological changes of the artery wall improved in high temperature treadmill supplementation with vitamin C group. Conclusion: Heat exposure has effect on oxidative stress, which may be related to the increase of BP. Vitamin C as an anti-oxidative enhancer can prevent those negative effects, which could alleviate the pathological changes of vessel intima in heat-exposed rats. And the Nrf2 may be a regulated factor to vascular protection.

[Correlation between intestinal and respiratory flora and their metabolites in a rat pneumoconiosis model]

Objective: Differential flora and differential metabolites shared by the intestinal and respiratory tracts of rats were screened to analyze the possible role of changes in intestinal flora and metabolites in the progression of pneumoconiosis in rats. Methods: In April 2020, 18 SD rats were randomly divided into three groups (control group, coal mine dust group and silica group, 6 in each group) , rats in the coal mine dust group and silica group were perfused with 1 ml of 50 mg/ml coal mine well dust suspension and silica suspension by nontracheal exposure, respectively. While rats in the control group were perfused with an equal dose of sterilized normal saline. Twenty four weeks after dust staining, rat feces, throat swabs, and lung lavages were collected. 16SrDNA gene sequencing and UHPLC-QTOF-MS untargeted metabolomics were used to analyze the flora and metabolites in feces, throat swabs and lung lavage fluid of rats in each group, to screen for shared differential flora and shared differential metabolites in intestinal and respiratory tract, and the correlation analysis between the differential flora and metabolites was performed using Spearman's statistics. Results: Compared with the control group, a total of 9 species shared differential flora between intestinal and respiratory tract were screened at phylum level, and a total of 9 species shared differential genus between intestinal and respiratory tract were screened at genus level in the coal mine dust group, mainly Firmicutes, Actinobacteria, Streptococcus, Lactobacillus, etc. Compared with the control group, a total of 9 shared differential flora were screened at the phylum level, and a total of 5 shared differential genus were screened at the genus level in the silica group, mainly Proteobacteria, Actinobacteria, Allobactera, Mucilaginibacter, etc. Compared with the control group, a total of 7 shared differential metabolites were screened for up-regulation of Stigmatellin, Linalool oxide and Isoleucine-leucine in both intestinal and respiratory tract in the coal mine dust group. Compared with the control group , a total of 19 shared differential metabolites werescreened in the silica group, of which Diethanolamine, 1-Aminocyclopropanecarboxylic acid, Isoleucine-leucine, Sphingosine, Palmitic acid, D-sphinganine, 1, 2-dioleoyl-sn-glycero-3-phosphatidylcholine, and 1-Stearoyl-2-oleoyl-sn-glycerol 3-phosphocholine were up-regulated in both the intestinal and respiratory tract. Conclusion: There is a translocation of intestinal and respiratory flora in pneumoconiosis rats, and rats have an imbalance of lipid metabolism during the progression of pneumoconiosis.

[Analysis on the rationality of input and output of occupational health funds in an iron and steel enterprise]

Objective: To analyzes the various occupational health investment and occupational health output of a steel enterprise, and propose a reasonable occupational health investment plan for this enterprise. Methods: In march 2016, various occupational health input and output data of various branches of an iron and steel company in 2015 were collected, and the efficiency of occupational health inputs and outputs of each branch was evaluated using data envelopment analysis (DEA) , and the branches with non-optimal efficiency were adjusted to propose a reasonable occupational health investment plan. Results: Among the branch plants investigated by this steel company, the occupational health input-output efficiency values of ironmaking north plant, power plant, hot rolling plant and stainless steel plant were 1, while the occupational health input-output efficiency of gas making plant, cold rolling plant, metallurgical furnace charge plant, coking plant, ironmaking south plant and long product plant were not the best, and the cold rolling plant has the lowest efficiency value of 0.759. For the cold rolling plant, only the parameters of acid rolling plant satisfy α=1 and s(-)=0, s(+)=0, while the remaining four workshops do not meet. After adjusting the inputs of each part according to the parameters, the occupational health output of the remaining four workshops can reach 1.7044, 2.0238, 1.3152 and 1.2136 times of the current workshop, respectively. Adjustment plans for other branch factories with unreasonable investment structures are also presented in the corresponding tables. Conclusion: The occupational health investment structure of the ironmaking south plant and other branches in this steel enterprise is unreasonable, and the adjustment using data envelopment analysis can maximize the benefits of its occupational health output.

Silica nanoparticle induces pulmonary fibroblast transdifferentiation via macrophage route: Potential mechanism revealed by proteomic analysis

Recently, more and more attention has been focused on silica nanoparticles (SiNPs) as they are increasingly used in various fields. Yet, their biological effects, especially on human beings, largely remain unknown. This study was implanted to assess the biological responses in vitro elicited by human macrophages exposed to the SiNPs and to explore its toxicity and fibrosis biomarker. We found that SiNPs suppressed the viability of THP-1 cells in a dose-dependent manner while they triggered apoptosis and promoted the secretion of inflammatory factors. Next, SiNPs-induced macrophage supernatant was used to act on fibroblast (MRC-5), indicating that the expression of hydroxyproline (Hyp), α-SMA, and collagonIin MRC-5 increased after SiNPs treatment. To further explore the biomarker of fibrosis, Liquid-mass spectrometry facilitated quantitative proteomics, identified 3247 proteins, of which 791 proteins were expressed differentially in human embryonic lung fibroblasts after treated with SiNPs. In conclusion, our observations suggest that SiNPs induced THP-1-derived macrophage damage and apoptosis. Moreover, SiNPs induced macrophages to secrete cytokines that promote fibroblasts' proliferation and differentiation and changed protein expression in MRC-5 cells, regulating biological processes such as apoptosis, protein synthesis, and cell growth. Among these results, our findings could provide a basis for determining fibrosis biomarkers of silica nanoparticle exposure.

Comparison of properties of dust in alveolar of rats and the workplace

OBJECTIVES

The purpose of this study was to analyze the α-SiO₂ content, composition, dispersion, morphology, and free radical content of dust between the alveolar and the workplace, to explore the possible changes in the properties (especially the pathogenicity) of dust after it enters the lung.

METHODS

We collected the dust in the workplace in HANDAN Coal mine. They were selected by a 400 mesh sieve and was made a suspension of 50 mg/ml, which would be used to perfuse into the trachea of rats. When one week, four weeks, eight weeks, fourteen weeks, twenty weeks after perfusing, we harvested dust in rats alveolar through lung lavage for further processing.

RESULTS

In the animal test, typical fibrous nodules appeared 20 weeks after dust exposure. No inflammatory reaction was observed in the saline group. The results of animal experiments showed that there was no significant difference in the content of α-SiO₂ between dust in the workplace and the lung lavage (P > 0.05). The content of the Fe element gradually increased with dust exposure time. The 12 elements of Al, Mg, Si, Pb, Mn, Ni, Zn, Cu, Cr, Sb, Cd, and AS were reduced in the experiment group compared with the workplace group. The shape of the dust in the workplace was mostly spherical. The shape of the dust extracted from the lung lavage fluid was mostly blocky and angular, and a few dust edges were sharp, and more than 80% of the particle size was smaller than 5 μm, while less than 1% of the particle size was larger than 10 μm. The amount of hydroxyl radical released by lung lavage dust in phosphate buffer was higher than that of the workplace dust.

CONCLUSIONS

After the dust entered the alveoli, the content of α-SiO₂ in the dust did not change with dust exposure time, while the content of elements in the dust, the morphology, and dispersion of the dust changed. The ability of dust in alveoli to produce hydroxyl radicals in phosphate buffer was higher than that in the workplace.

[Progress of researches on symbionts in the management of mosquito-borne infectious diseases]

Mosquitoes are the main vectors of many infectious diseases, including malaria and yellow fever, which seriously threaten human health across the world. In addition to the use of chemical insecticides, genetic control is a new attempt to currently available interventions used for mosquito vector control. In terms of ecological safety, however, symbiotic control as a novel approach has been proposed for mosquito control. Since there are multiple symbiotic microflora inhabiting in a variety of tissues of mosquitoes, including the digestive tract, they may affect the transmission of mosquito-borne infectious diseases through affecting the lifespan, reproductive competence, and vector competence of the host. In this review, the interactions between symbionts in mosquitoes were summarized, and the research progress of mosquito-associated symbionts in the management of mosquitoborne infectious diseases was reviewed.

[Analysis of occupational health input-output of a iron mine in Hebei province]

Objective: To explore the relationship between input and output of occupational health funds, and to provide basis for relevant departments to make decisions. Methods: In September 2018, a state-owned iron ore in Hebei Province (mining history of more than 10 years, which can represent the general type of iron ore) was selected as the research object. Through the investigation and collection of enterprise general situation, occupational health input, loss and output related indicators, the iron mine occupational health expenditure input-output table and model were established, and the digital relationship between the investment and output was solved by MATLAB software. Results: The labor consumption in the departments of underground mining, open pit mining, crushing and rock discharging, transportation, tailings and mineral processing (taking labor wages as reference) were 756.46, 1.281.78, 987.61, 1 570.71, 50.956 and 18.9116 million yuan/year respectively. The output value of each sector is 11 207.19, 18 989.95, 15 176.40, 25 294.00, 7.704.94 and 280.1797 million yuan/year respectively. The ratio of health input to total output was 0.004 5, and the ratio of occupational health input to output was 1/0.046. Conclusion: The input-output table model of occupational health in iron mine can reflect the relationship between input and output of occupational health funds. The input situation of the coal mine is poor, and the input does not bring obvious occupational health benefits.

Silica dust exposure induces autophagy in alveolar macrophages through switching Beclin1 affinity from Bcl-2 to PIK3C3

Increased deposition of silica dust in pulmonary interstitial tissues leads to silicosis, in which autophagy plays a defensive role in silica dust-associated stress response and cell death. Our previous studies revealed that silica dust exposure contributed to autophagy in pulmonary macrophages in vivo, while the specific regulatory mechanism is still unclear. This study aimed to figure out the regulatory mechanism as well as the role of autophagy in the pathogenesis of experimental silicosis. We used 3-methyladenine (3-MA) and ABT-737 to suppress the expression of phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) and B cell leukemia/lymphoma 2 (Bcl-2), two critical initiators of autophagy, and detected and evaluated the autophagy in NR8383 cells with or without silica dust exposure. We found that exposure of silica dust increased autophagy in NR8383 cells and elevated the expression of Beclin1 and PIK3C3, but it reduced the expression of Bcl-2. The relationship among Beclin1, PIK3C3, and Bcl-2 were then investigated using immunoprecipitation analysis, and we found that suppression of PIK3C3 and/or Bcl-2 using 3-MA and/or ABT-737 could alter the autophagy induced by silica dust in NR8383 cells, and the complexes of Beclin1/PIK3C3 and Beclin1/Bcl-2 were both downregulated, which may be that inhibition of PIK3C3 and Bcl-2 altered the affinity of Beclin1 with PIK3C3 and Bcl-2 and lead to the silence of PIK3C3 signaling. These findings indicate that silica dust exposure induces autophagy via changing the connectivity of Beclin1 from Bcl-2 to PIK3C3.

Activation of MAPK and Cyclin D1/CDK4 in Malignant Transformation of Human Embryonic Lung Fibroblasts Induced by Silica and Benzopyrene

Objective:

Silica and Benzo(a)pyrene are listed as carcinogens. This study aims to explore Cyclin D1, CDK4 and difference of cell cycle adjusted by MAPK signal transduction pathway in silica and B(a)P-induced malignant transformation of human embryonic lung fibroblasts.

Methods:

Activity of the subfamily (ERK, p38 and JNK) of mitogen-activated protein kinase (MAPK), cyclin D1 and CDK4 (cyclin dependent kinase) were evaluated using Human embryonic lung fibroblast (HELF) purchased from the cell room, basic research institute, Chinese Academy of Medical Sciences. The expression of cyclin D1 and CDK4 (cyclin dependent kinase) were measured in silica and B(a)P induced malignant using Western blot (WB) assay.

Results:

P-ERK and P-JNK expression increased significantly (P<0.01), while CDK4 and P-p38 expression decreased (P<0.01, P<0.05) in silica-induced malignant transformation cells compared with the control group. P-ERK, P-JNK and Cyclin D1 expression increased (P<0.01, P<0.01, P<0.05) in B(a)P-induced group compared with the control group. P-ERK and P-JNK expression decreased (P<0.01), while P-p38, Cyclin D1 and CDK4 expression increased (P<0.05, P<0.05, P<0.01) in B(a)P-induced group compared with the silica-induced group.

Conclusion:

MAPK and cyclin D1/CDK4 activation expressed differently in human embryo lung fibroblasts malignant transformation induced by silica and benzopyrene.

Bioinformatics analysis on differentially expressed genes of alveolar macrophage in IPF

Objective: This study aimed to explore the differentially expressed genes (DEGs) of pulmonary macrophages in human idiopathic pulmonary fibrosis (IPF) by bioinformatics, and elaborate on IPF on the gene level. Methods: The gene expression profile GSE49072 was downloaded from the gene expression omnibus (GEO) database. Genes of alveolar macrophages between normal volunteers and patients diagnosed as IPF were analyzed by GEO2R tools. Gene ontology (GO) and pathway enrichment analyses of genes were performed in the database for annotation, visualization and integrated discovery (DAVID) database, followed by functional annotation and protein-protein interaction (PPI) network construction in String website. Finally, the results were analyzed in a comprehensive way. Results: A total of 551 DEGs, including 205 down-regulated and 346 up-regulated were identified. The expression of 209875_s_at (secreted phosphoprotein 1, SPP1) and 214146_s_at (pro-platelet basic protein, PPBP) genes are the most significant in upregulated genes. DEGs in the MAPK（mitogen-activated protein kinase） signaling pathway and chemokine signaling pathway play important roles in the development of IPF. Conclusions: The up-regulation of genes such as SPP1 and PPBP affect the secretion of alveolar macrophages, thereby speeding up the process of fibrosis.

[Association between polymorphisms of interleukin-17 genes and pneumoconiosis susceptibility]

Objective: To explore the relationship between polymorphisms of interleukin 17(IL-17) gene (rs4711998, rs763780) and the susceptibility of pneumoconiosis, and to provide a basis for prevention of high-risk groups of pneumoconiosis. Methods: A total of 219 pneumoconiosis patients and 242 workers without pneumoconiosis were enrolled in the study. All subjects were photographed with high undulating X-rays anterior chest radiographs, diagnosed according to diagnostic criteria for pneumoconiosis. We collected 3 ml of peripheral venous blood of the study subjects. Polymorphism in IL-17A rs4711998 and IL-17F rs763780 locus were evaluated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The IL-17A rs4711998 locus has AA, AG and GG genotypes, there was no the significant difference between case and control groups (P>0.05). IL-17F rs763780 had AA, AG and GG genotypes, there was a significant difference between case and control groups (P<0.05). Allele A and allele G were statistically significant difference between the case group and the control group (P<0.05). Conclusion: No relationship was found between IL-17A gene polymorphisms at rs4711998 and silicosis. IL-17F rs763780 locus gene polymorphism is associated with susceptibility to pneumoconiosis. AG genotype and G allele may have a protective effect.

[Comprehensive rehabilitation of individualized exercise program for coal workers pneumoconiosis in Huaibei Coal Mine Group]

Objective: To explore the effect of comprehensive rehabilitation treatment of individualized exercise program on lung function, exercise ability, quality of life and biochemical indexes of coal workers' pneumoconiosis patients, and to provide scientific and effective methods for rehabilitation treatment of coal workers' pneumoconiosis. Methods: In Huaibei Coal Mine Occupational Disease Prevention and Control Hospital, the data of pneumoconiosis patients treated by pneumoconiosis department in the hospital were collected and sorted out. 80 patients were selected according to the inclusion and exclusion criteria. Using a random number table, they were randomly divided into two groups with 40 cases in each group. The data investigated in this study include the results before and after treatment. Pulmonary function index, BMI index, six-minute walking distance (6MWD) , quality of life questionnaire (SF-36) , hospital anxiety and depression scale (HADS) , st George's breathing questionnaire (sgrq) , c-reactive protein (CRP) and blood oxygen saturation (SpO(2)) were used to evaluate and compare the efficacy of the two groups. Results: The lung function indexes of the test group were significantly higher than those of the control group after treatment (P<0.05) , including forced vital capacity, forced vital capacity in the first second, maximum expiratory flow, expiratory flow when vital capacity was 75% and expiratory flow when vital capacity was 25%. The forced vital capacity, the first-second forced vital capacity and the maximum expiratory flow of the patients in the test group were higher after treatment than before (P<0.05) . The six-minute walking distance of the test group was greater than that of the control group after treatment (P<0.05) . After treatment, the scores of st George's breathing questionnaire in the test group were lower than those in the control group (P<0.05) . The scores of quality of life questionnaire in the test group were higher than those in the control group after treatment (P<0.05) . Conclusion: The comprehensive rehabilitation treatment of individualized exercise program improved the endurance and exercise ability of pneumoconiosis patients, improved the respiratory status and quality of life of pneumoconiosis patients in Huaibei Coal Mine, improved the lung function of pneumoconiosis patients, and improved the forced vital capacity of patients, but the small airway function has not been significantly improved.

Establishment and application of an index system for prevention of coal workers' pneumoconiosis: a Delphi and analytic hierarchy process study in four state-owned coal enterprises of China

OBJECTIVE

To explore the difference of cumulative incidence rate of coal workers' pneumoconiosis (CWP) among four large state-owned coal enterprises in northern China, we created an index system for evaluating the quality of comprehensive measures against CWP and applied the system to evaluate and compare the measures of the four coal enterprises.

METHODS

A two-round Delphi investigation was conducted to identify the indicators in the index system. The weight values of the indicators were calculated with analytic hierarchy process methods. Measures of CWP, mine annals, records and other information in each coal mine of the four enterprises were collected. The evaluation scores, which ranged from 0 to 100, were calculated and compared with.

RESULTS

A three-grade index system with 3 first-grade indicators, 9 second-grade indicators and 44 tertiary-grade indicators was established. The expert authority coefficient (C_r ) was 0.75 and the Kendall's coefficient of concordance (Kendall's W) was 0.15 (χ²=193.30, P<0.001). The weight value of 'Geological conditions' was 0.43, equal to 'Dust control engineering technology', and that of 'Occupational health management' was 0.14. The medians and quartiles of the evaluation scores of comprehensive measures against CWP of the four enterprises were 58.38 (54.60~63.02), 64.63 (60.83~67.06), 72.99 (68.92~77.67) and 75.07 (70.73~79.20), respectively.

CONCLUSIONS

The index system could be effectively used for evaluation and comparison of the comprehensive measures against CWP among different enterprises. The geological conditions and dust control engineering technology played an important role in preventing and controlling CWP.

Cost-Effectiveness of Coal Workers' Pneumoconiosis Prevention Based on Its Predicted Incidence within the Datong Coal Mine Group in China

We aimed to estimate the economic losses currently caused by coal workers’ pneumoconiosis (CWP) and, on the basis of these measurements, confirm the economic benefit of preventive measures. Our cohort study included 1,847 patients with CWP and 43,742 coal workers without CWP who were registered in the employment records of the Datong Coal Mine Group. We calculated the cumulative incidence rate of pneumoconiosis using the life-table method. We used the dose-response relationship between cumulative incidence density and cumulative dust exposure to predict the future trend in the incidence of CWP. We calculate the economic loss caused by CWP and economic effectiveness of CWP prevention by a step-wise model. The cumulative incidence rates of CWP in the tunneling, mining, combining, and helping cohorts were 58.7%, 28.1%, 21.7%, and 4.0%, respectively. The cumulative incidence rates increased gradually with increasing cumulative dust exposure (CDE). We predicted 4,300 new CWP cases, assuming the dust concentrations remained at the levels of 2011. If advanced dustproof equipment was adopted, 537 fewer people would be diagnosed with CWP. In all, losses of 1.207 billion Renminbi (RMB, official currency of China) would be prevented and 4,698.8 healthy life years would be gained. Investments in advanced dustproof equipment would be total 843 million RMB, according to our study; the ratio of investment to restored economic losses was 1:1.43. Controlling workplace dust concentrations is critical to reduce the onset of pneumoconiosis and to achieve economic benefits.

[Investigation on psychological stress of mine emergency rescue personnel]

OBJECTIVE

To investigate psychological stress and influence factors on the mine emergency rescue personnel.

METHOD

564 mine emergency rescue personnel from a rescue group were select as subjects, and 60 designers from a steel design institute were as controls. Self-made questionnaire and general job stress questionnaire were used to investigate the basic information, rescue history, psychosomatic symptoms, depression symptoms, daily job stress and negative emotions of emergency rescue personnel. SPSS17.0 software was used to analysis the psychological stress on the mine rescue personnel and its influence factors.

RESULTS

The detection rate (41.94%) of depression symptoms in rescue team was higher than that of controls (24.90%). The score of daily job stress was higher than that of logistical support. The older age group with higher negative emotional and daily job stress than the younger. The highest negative emotion was in age group of more than 40 years old. The highest score of daily job stress was in ≤30 years old. The score of depression and psychosomatic symptoms were higher than those of the college and the above. The scores of depression in group of duration of rescue <10 years was higher than that of duration≥10 years. The score of daily job stress is the lowest in rescue for 1 to 2 times per year and the highest in group of simulation training once a week. The score of daily job stress and depressive symptoms were getting higher with the extension of combat duty time. Age, hours of combat duty, training times a week, education and life events were the main affecting fectors on mental health of mine rescuers.

CONCLUSIONS

Mine rescuers have more psychological stress than generic population. The psychological stress of the mine crew is related to age, education, life events, training and combat readiness duty time.

[Relationship between genetic polymorphisms of matrix metalloproteinase-2 and -3 and susceptibility to silicosis]

OBJECTIVE

To investigate the relationship between the genetic polymorphisms of matrix metalloproteinase-2 (MMP-2) (-735) and matrix metalloproteinase-3 (MMP-3) (-1171) and the susceptibility to silicosis.

METHODS

A case-control study was conducted in 113 patients diagnosed with stage I silicosis (case group) and 115 dust-exposed workers without silicosis (control group); the two groups had the same sex, ethnic group, and type of dust and similar age and cumulative exposure time. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the genotypes of MMP-2 (-735) and MMP-3 (-1171).

RESULTS

No significant difference was observed in age, cumulative exposure time, or smoking rate between cases and controls (P > 0.05). The frequencies of genotypes C/C, C/T, and T/T at MMP-2 C-735T in the case group were 57.5% (65/113), 31.0% (35/113), and 11.5% (13/113), respectively, which were significantly different from those of the control group (69.6% (80/115), 26.9% (31/115), and 3.5% (4/115)), χ² = 6.542, P < 0.05). The frequencies of T allele in cases and controls were 27.0% and 17.0%, respectively, which were significantly different from each other χ² = 6.704, P < 0.05). Carriage of T allele at MMP-2 C-735T increased the risk of silicosis (OR = 1.811, 95% CI: 1.151-2.847). The frequencies of genotypes 6A/6A, 5A/6A, and 5A/5A at MMP-3 A-1171A were 67.2% (76/113), 24.8% (28/113), and 8.0% (9/113), respectively, in the case group, versus 59.1% (68/115), 37.4% (43/115), and 3.5% (4/115) in the control group (χ² = 5.519, P > 0.05).

CONCLUSION

Genetic polymorphism at MMP-2 C-735T is significantly associated with the development of silicosis. Carriage of T allele increases the risk of silicosis among workers exposed to dust. No significant association was found between MMP-3 A-1171A polymorphism and silicosis in this study.

Risk identification and prediction of coal workers' pneumoconiosis in Kailuan Colliery Group in China: a historical cohort study

BACKGROUND

Prior to 1970, coal mining technology and prevention measures in China were poor. Mechanized coal mining equipment and advanced protection measures were continuously installed in the mines after 1970. All these improvements may have resulted in a change in the incidence of coal workers' pneumoconiosis (CWP). Therefore, it is important to identify the characteristics of CWP today and trends for the incidence of CWP in the future.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 17,023 coal workers from the Kailuan Colliery Group were studied. A life-table method was used to calculate the cumulative incidence rate of CWP and predict the number of new CWP patients in the future. The probability of developing CWP was estimated by a multilayer perceptron artificial neural network for each coal worker without CWP. The results showed that the cumulative incidence rates of CWP for tunneling, mining, combining, and helping workers were 31.8%, 27.5%, 24.2%, and 2.6%, respectively, during the same observation period of 40 years. It was estimated that there would be 844 new CWP cases among 16,185 coal workers without CWP within their life expectancy. There would be 273.1, 273.1, 227.6, and 69.9 new CWP patients in the next <10, 10-, 20-, and 30- years respectively in the study cohort within their life expectancy. It was identified that coal workers whose risk probabilities were over 0.2 were at high risk for CWP, and whose risk probabilities were under 0.1 were at low risk.

CONCLUSION/SIGNIFICANCE

The present and future incidence trends of CWP remain high among coal workers. We suggest that coal workers at high risk of CWP undergo a physical examination for pneumoconiosis every year, and the coal workers at low risk of CWP be examined every 5 years.

Fas/FasL pathway-mediated alveolar macrophage apoptosis involved in human silicosis

In vitro and in vivo studies have demonstrated that lung cell apoptosis is associated with lung fibrosis; however the relationship between apoptosis of alveolar macrophages (AMs) and human silicosis has not been addressed. In the present study, AM apoptosis was determined in whole-lung lavage fluid from 48 male silicosis patients, 13 male observers, and 13 male healthy volunteers. The relationships between apoptosis index (AI) and silica exposure history, soluble Fas (sFas)/membrane-bound Fas (mFas), and caspase-3/caspase-8 were analyzed. AI, mFas, and caspase-3 were significantly higher in lung lavage fluids from silicosis patients than those of observers or healthy volunteers, but the level of sFas demonstrated a decreasing trend. AI was related to silica exposure, upregulation of mFas, and activation of caspase-3 and -8, as well as influenced by smoking status after adjusting for confounding factors. These results indicate that AM apoptosis could be used as a potential biomarker for human silicosis, and the Fas/FasL pathway may regulate this process. The present data from human lung lavage samples may help to understand the mechanism of silicosis and in turn lead to strategies for preventing or treating this disease.

[Investigation about prevention behavior for dust workers in machinery, ceramic, and metallurgy industry]

OBJECTIVE

The purposes of this thesis were to study the behavior about workers exposed to dust and provide scientific basis for health promotion.

METHODS

We designed a questionnaire and carry it on the 746 dust workers in the 3 representative corporations of Machinery, Ceramic, and Metallurgy Industry. All data were input into computer. And a database was established with Excel. SPSS11.5 statistical analysis software was used to analyze the influence on protecting behavioral between the application of qualifications, different jobs, training or protection, and other aspects etc.

RESULTS

The rates were 94.4% and 75.3% about the regular physical examination and requirements for protective equipment. The rate of choosing an effective way of protection was generally low (15.4%). There was significant difference for among different educational background workers (P < 0.01). The rates of choosing an effective way of protection (20.3%), the regular physical examination (98.3%) and requirements for protective equipment (86.4%) in the dust workers who participated in the training of dust protection were superior than those who did not participated in the training. There was the significant difference (P < 0.05, P < 0.01). There was the significant difference for the rate of effective way of protection, regular physical examination, and requirements for protective equipment among the different corporations (P < 0.05).

CONCLUSIONS

Dust workers' using rate about the choosing an effective way of protection was generally low in Machinery, Ceramic, and Metallurgy Industry. Those who were not educated had a lower using rate about the protection behavior, regular physical examination, and requirements for protective equipment than those educated.

[Investigation on job stress of pediatricians and nurses working in pediatric department]

OBJECTIVE

To investigate the occupational stressors and modifiers of pediatricians and nurses in order to find the measurements for control of the job stress.

METHODS

427 pediatricians and nurses working in five hospitals of a city served as subjects. Of them, the staff in section of pharmacy and toll offices in each hospital mentioned above served as control group. The General Job Stress Questionnaire was used to investigate the job stress by self-assessment.

RESULTS

The scores of job demand, job risk, drug using, daily job stress, positive feelings, patient A behavior, physical environment and feeling balance in pediatricians and nurses were higher than those of control group, but the scores of job-person conflict, environmental control, technology utility, mental health, responsibility on things were lower than those of control group (P<0.05). The points of job future, job locus of control, self-esteem, job satisfaction, job load variance, depression in nurses were higher than those of pediatricians, and non-work activities, job risk and daily life stress were lower than those of doctors (P<0.05). The main affecting factors on job strain of pediatric staff included job monotony, higher job demand, more non-work job, lower job control, more job risk, job future ambiguous, poorer social support, lower job locus control and lower self-esteem.

CONCLUSION

The stress degree of pediatric staff is higher than that of controls. The pediatricians have more job stress than that of nurses. The main stressors of pediatric staff are job monotony, higher job demand, more non-worker activity, lower job control, higher job risk and ambiguous job future. The main modifiers are good social support, external job locus of control and higher self-esteem.

Downregulation of cyclin D1-CDK4 protein in human embryonic lung fibroblasts (HELF) induced by silica is mediated through the ERK and JNK pathway

Silica is a factor in the induction of acute injury and chronic pulmonary fibrosis. In 1996, silica was also listed as a human carcinogen by the International Agency for Research on Cancer (IARC). However, the molecular mechanisms involved in its pathologic effects are not well understood. We found that exposure of human embryonic lung fibroblasts (HELF) to crystalline silica for 2h decreased cyclin D1 and cyclin-dependent kinase 4 (CDK4) expression levels. Extracellular signal-regulated protein kinase (ERKs), c-Jun NH2-terminal amino kinase (JNKs), and p38 kinase, as well as their downstream transcription factor, AP-1, had different effects on the regulation of expression levels of cyclin D1 and CDK4 alterations induced by silica. Silica activates multiple signal transduction pathways involved in coordinating cellular responses to stress. We established the requirements for ERK and JNK, members of the mitogen-activated protein kinase (MAPK) family, in mediating G1 phase arrest of HELF induced by silica. Silica treatment activated ERK in a dose-dependent manner. AG126 (a chemical inhibitor of the ERK signaling pathway) and the dominant negative mutant of ERK2 (a molecular inhibitor of ERK2) prevented decreases in cyclin D1 and CDK4 expression levels. A chemical inhibitor of JNK, SP600125, prevented the decreased expression of both cyclin D1 and CDK4, whereas SB203580, a chemical inhibitor of p38, did not. Interestingly, curcumin prevented the decrease in DK4 expression, but not in cyclin D1. These results demonstrate that ERKs and JNKs are responsible for the decrease of cyclin D1 and CDK4 expression levels in HELF induced by silica. Activator protein-1 (AP-1) was responsible for the decrease of CDK4 expression level, but not that of cyclin D1. The findings help to explain the mechanisms of diseases induced by silica.

[Benzo (a) pyrene-induced human embryo lung cell cycle alterations through positive regulation of mitogen-activated protein kinase signal pathways]

OBJECTIVE

To study the effects of benzo(a)pyrene (BaP) on the cell cycle distribution and activities of mitogen-activated protein kinase (MAPK) signal molecules (ERK1/2, JNK1/2 and p38) in human embryo lung cells (HELF), and to investigate the relationship between alterations of MAPK protein phosphorylation and the cell cycle distributions.

METHODS

The phosphorylation of MAPK were induced by exposing HELF cells to BaP at 0.1, 0.5, 2.5 and 12.5 micromol/L. The phosphorylation and protein expression levels of ERK1/2, JNK1/2 and p38 were determined through western-blotting assay. And the flow cytometry assay was used to measure the cell cycle effects in HELF cells after treatment with 2.5 micromol/L BaP for 24 h.

RESULTS

The phosphorylation levels of ERK1/2, JNK1/2 and p38 were significantly increased through BaP exposure. In addition, the phosphorylation of these three MAPKs has similar alteration pattern. We found that exposure of cells to 2.5 microM of BaP for 24 h resulted in a decrease of G(0) and G(1) population by 11.9% (F = 41.38, P < 0.01) and an increase of S population by 17.2% (F = 68.13, P < 0.01). Three chemical inhibitors of MAPK (AG126, SP600125 and SB203580) could significantly inhibit the cell cycle alteration because of BaP treatment.

CONCLUSION

ERK1/2, JNK1/2 and p38 could positively regulate the BaP independently induced cell cycle alterations.

[Vitamin C reverses benzo (a) pyrene-induced cell cycle changes by E2F pathway]

OBJECTIVE

To study the role of E2F1/4 pathway in vitamin C reversing benzo (a) pyrene [B (a) P]-induced changes of cell cycle in human embryo lung fibroblasts (HELF) and the relationship between E2F1 and cyclin D1/CDK4.

METHODS

The stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established to detect the relationship of signaling pathway. Cells were cultured and pretreated with vitamin C before stimulation with B (a) P for 24 hours. The expression levels of cyclin D1, CDK4, E2F1 and E2F4 were determined by Western blot and the band intensity was analysed as the relative value to control by using the Gel-Pro 3.0 software. Flow Cytometric Analysis was employed to detect the distributions of cell cycle.

RESULTS

B (a) P significantly elevated the expression levels of cyclin D1, CDK4, E2F1 and E2F4 in HELF cells. Vitamin C decreased the expression levels of above proteins in B (a) P-stimulated HELF cells. The expression levels of these proteins in B (a) P-treated above transfectants were lower than those in B (a) P-treated HELF cells. The expression levels of above proteins with vitamin C combined with antisense cyclin D1 were decreased as compared to those with antisense cyclin D1 alone. B (a) P increased the percentage of S phase as compared to the controls [(41.1 +/- 0.2)% vs (33.5 +/- 3.2)%, P < 0.05]. Both vitamin C [(33.2 +/- 0.6)% vs (41.1 +/- 0.2)%, P < 0.05] and antisense cyclin D1 [(31.2 +/- 1.3)% vs (41.1 +/- 0.2)%, P < 0.05] suppressed the changes of cell cycle induced by B (a) P. Vitamin C combined with antisense CDK4 markedly suppressed B (a) P-induced changes of cell cycle as compared to those with antisense CDK4 alone.

CONCLUSION

Vitamin C might reserve the B (a) P-induced changes of cell cycle via intracellular signaling pathway of cyclin D1-CDK4/E2F-1/4.

[cyclin D1/E2F pathways involved in cell cycle changes of human embryo lung fibroblasts induced by benzo(a)pyrene]

OBJECTIVE

To investigate the roles of cyclin D1/CDK4-E2F-1/4 pathway in cell cycle changes of human embryo lung fibroblasts (HELF) induced by two different benzo(a)pyrene [B(a)P] treatment models.

METHODS

Two B(a)P treatment models: HELF were treated by 2 micromol/L B(a)P for 24 hours; HELF were treated by 100 micromol/L B(a)P three times 24 hours each and provide with some characteristics of transformed cells (T-HELF). Changes of cell cycle and the expression of cyclin D1, CDK4 and E2F-1/4 were checked using the flow cytometry and Western bolt analysis.

RESULTS

After 24 hours 2 microml/L B(a)P treatment, the HELFs in the G(1) phase was decreased. In HELF transfected with antisense cyclin Dl (A-Dl) and antisense CDK4 (A-K4), the expression of cyclin Dl and CDK4 blocked the cell cycle changes from the G(1) phase to the S phase induced by B(a)P. The overexpression of cyclin Dl and E2F-1 in HELF was induced by B(a)P. The E2F-1 overexpression in A-D1 induced B(a)P was inhibited. The E2F-4 expression was decreased and the CDK4 expression was increased significantly in A-K4 after B(a)P treatment. Most of T-HELF transfected with antisense cyclin Dl (T-A-Dl) and antisense CDK4 (T-A-K4) were retained in G(1) phase. The cyclin Dl expression in T-HELF was increased significantly compared with that in HELF. The E2F-4 expression in T-A-Dl and T-A-K4 was increased significantly compared with that in T-HELF.

CONCLUSION

B(a)P induces the cell cycle changes through cyclin D1/CDK4-E2F-1/4 pathway in HELF treated by 2 micromol/L B(a)P while it induces cell cycle changes through cyclin D1/CDK4-E2F-4 pathway in T-HELF.

Overexpression of cyclin D1-CDK4 in silica-induced transformed cells is due to activation of ERKs, JNKs/AP-1 pathway

Silica has been known to be a factor inducing acute injury and chronic pulmonary fibrosis. Silica has also been listed as a human carcinogen in 1996 by International Agency for Research on Cancer (IARC). However, the molecular mechanisms involved its pathologic effects are not well understood. In these studies, we found that exposure of human embryonic lung fibroblasts (HELF) to crystalline silica could cause increases in activation of extracellular signal-regulated kinases (ERKs), p38K, and c-Jun NH2-terminal amino kinases (JNKs), and HELF transformation. Interestingly, silica-induced transformation of HELF (S-HELF) led to increases in activated levels of ERKs and p46 of JNKs, and decrease in p38K activation, and no effect on activation of p54 of JNKs, as compared with those in parental HELF. Further studies showed that there are differential effects of ERKs, JNKs and p38K, as well as their downstream transcription factor AP-1, in regulation of expression of cyclin D1 and CDK4 and cell cycle alternations induced by silica. Cyclin D1 and CDK4 were increased in S-HELF as compared with those in HELF. Inhibition of ERKs activation by AG126, JNK by SP600125, and AP-1 by curcumin could reduced the induction of cyclin D1 and CDK4. There is no significant difference for cell cycle distribution between groups. These results demonstrate that ERKs and JNKs, but not p38K is responsible for induction of cyclin D1 and CDK4 in S-HELF, suggesting that overexpression of cyclin D1 and CDK4 caused by silica is mediated by ERK, JNK/AP-1signaling pathway.

Inhibition of benzo(a)pyrene-induced cell cycle progression by all-trans retinoic acid partly through cyclin D1/E2F-1 pathway in human embryo lung fibroblasts

Benzo(a)pyrene [B(a)P] is a potent environmental carcinogen, which induces cell cycle changes. All-trans retinoic acid (ATRA) is a promising agent in prevention and treatment of human cancers. In the present study, we investigated the inhibition of B(a)P-induced cell cycle progression by ATRA in human embryo lung fibroblast (HELF). Our results showed that after treatment with B(a)P, the expression of cyclin D1 and E2F-1 were both increased significantly in HELF. There were almost no changes of CDK4 and E2F-4 expression by treatment with B(a)P. As expected, pretreatment with ATRA could efficiently decrease B(a)P-induced overexpression of cyclin D1 and E2F-1. In a further study, we stably transfected antisense cyclin D1 and antisense CDK4 plasmid into HELF. The inhibition of cyclin D1 expression and the inhibition of CDK4 expression significantly impaired the B(a)P-induced overexpression of E2F-1 respectively. Pretreatment with ATRA, cells expressing antisense cyclinD1 or antisense CDK4 showed a lesser decrease of B(a)P-induced overexpression of E2F-1 compared with similarly treated HELF. Furthermore, flow cytometry analysis showed that B(a)P promoted cell cycle progression from G(1) phase to S phase, while pretreatment with ATRA could inhibit B(a)P-induced cell cycle progression by an accumulation of cells in the G(1) phase. It was suggested that ATRA could block B(a)P-induced cell cycle promotion partly through the cyclin D1/E2F-1 pathway in HELF.

[Inhibition of the pathway of benzo (a) pyrene-induced cell cycle changes by all-trans retinoic acid in lung fibroblast]

OBJECTIVE

To investigate the reverse effect of all-trans retinoic acid (ATRA) on Benzo (a) pyrene (B (a) P)-induced cyclin D1, CDK4, E2F-1 and E2F-4 expression and cell cycle progression in human embryo lung fibroblast (HELF).

METHODS

After HELF cells was treated with ATRA, they were exposed to 2 micromol/L of B (a) P. Western blotting was employed to detect protein expression level; the RNA transfection techniques was used to investigate ATRA-induced signal pathway; flow cytometry was used to detect cell cycle progression.

RESULT

After treatment with 2 micromol/L B (a) P for 24 h, the expression of cyclin D1 and E2F-1 were both increased significantly in HELF; the expression of E2F-4 and CDK4 were not changed markedly; pretreatment with 0.1 micromol/L ATRA for 24 h could efficiently decrease B (a) P-induced overexpression of cyclin D1 and E2F-1; stimulation to antisense cyclin D1 or antisense CDK4 by B (a) P could significantly impair E2F-1 up-regulation; pretreatment with ATRA, cells with antisense cyclin D1 or antisense CDK4 showed a less decrease in B (a) P-induced overexpression of E2F-1 compared to similarly treated control cells; flow cytometry analysis showed B (a) P promoted cell cycle progression from G(1) phase to S phase, while pretreatment with ATRA could inhibit B (a) P-induced cell cycle progression by an accumulation of cells in the G(1) phase.

CONCLUSION

ATRA could block B (a) P-induced cell cycle promotion through cyclin D1/E2F-1 pathway in HELF.

Clearance of theophylline by hemodialysis in one patient with chronic renal failure

The clearance of theophylline by hemodialysis was determined in one patient who had polycystic kidney with chronic renal failure and bronchial asthma. The serum levels of theophylline were determined by enzymatic immunoassay on two consecutive days, once on a dialysis day and again on a nondialysis day. Clearance of theophylline by hemodialysis was 119 ml/min, and the extraction efficiency was 0.56. The elimination half-life of theophylline shortened from 5.7 h to 1.6 h during hemodialysis. The dialysis rate constant (Kd) was 0.32/h, and 79 percent of the total body store of the drug was removed during a 4-h dialysis. Patients receiving theophylline who are maintained on hemodialysis should be closely monitored for bronchospasm during and after the hemodialysis procedure. Measurement of serum concentrations of theophylline should be employed to facilitate increases in dosage during hemodialysis.

Abnormal pre-drainage serum creatinine as a prognostic indicator in acute cholangitis

Two hundred and twenty-five patients diagnosed as having non-malignant acute cholangitis were studied to evaluate the incidence and prognostic significance of pre-drainage acute renal failure. Thirty-seven patients (16.4%) were found to have serum creatinine greater than, or equal to, 1.5 mg/dl before the drainage procedure. The risk factors for impaired renal function evaluated by multivariate analysis were advanced age, low albumin, low globulin, and clinical presentation of Charcot's triad or Reynold's pentad. The mortality rate in the abnormal pre-drainage serum creatinine group was 21.6%, which was much higher than the mortality (3.7%) seen in the normal serum creatinine group (p less than 0.0001). The other risk factors of mortality evaluated by multivariate analysis were the bilirubin level, combined common bile duct stones and intrahepatic duct stones, and bile duct stricture. We conclude that abnormal pre-drainage serum creatinine is not an uncommon finding in acute cholangitis. It is of prognostic significance, and should be considered as important as the clinical findings of Reynold's pentad.

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study

We measured mortality and morbidity among 114 patients assigned randomly to home hemodialysis (HD) and home intermittent peritoneal dialysis (IPD). Data were collected during the time of home training and for 12 months after initiation of home dialysis. Training time was shorter for the IPD than for the HD patients (P less than 0.001) with median time 1.8 months for IPD and 3.9 months for HD. Switching to the alternative mode of treatment was more frequent for the IPD group (29/59 vs. 5/55, P less than 0.001). Survival time was not different, perhaps because of the modality change. More IPD patients were hospitalized in the first 6 months (20 for IPD vs. 9 for HD, P = 0.02), but they had fewer troublesome cardiovascular events in the first year (0 vs. 12, P less than 0.001). The HD patients maintained better nutritional status as reflected in body weight and arm muscle circumference and possibly in urea appearance rate. Thus, these data suggest that for most patients, IPD is a less satisfactory form of therapy than HD, but certain advantages of IPD did emerge. Applications of this information to the currently more popular mode of CAPD await further study.

Effects of oxygen administration on the manifestation of acetate intolerance in dialysis patients

In a prospective double-blind study. 12 patients were dialyzed four times each with nasal oxygen (O2) and 4 times each with air throughout acetate dialysis. Fewer symptoms (p less than 0.01), improved postdialysis task performance (p less than 0.04) and a tendency for less mean blood pressure drop (p less than 0.07 two-sided) were noted on O2 dialyses than on air dialyses. The rate of acetate metabolism was increased during O2 dialyses since serum acetate levels were significantly lower at 2, 3 and 4 h. Significant hypoxemia was demonstrated in 10 of these patients on acetate dialysis without O2. These results clearly demonstrate that: (1) prevention Of hypoxemia during dialysis reduces acetate intolerance, and (2) compromised tissue O2 availability may be partly responsible for dialysis morbidity.

Increased immunoreactive calcitonin in idiopathic hypercalciuria

Serum immunoreactive calcitonin concentration (iCT) was determined in nine subjects with idiopathic hypercalciuria (IH), prior to and during oral phosphate supplementation (500 mg qid) to test the hypothesis that a renal phosphate leak was the primary defect resulting in IH in these patients. Prior to the oral phosphate supplementation, serum iCT was significantly elevated in the IH group, when compared to 26 normal individuals (75 +/- 7 vs 45 +/- 4 pg/ml, mean +/- SE, P less than .001). During oral phosphate treatment, however, serum iCT decreased to levels not significantly different from normals (39 +/- 3 and 50 +/- 5 pg/ml after 4 and 8 weeks, respectively). When data prior to and during phosphate supplementation were pooled, there was a significant correlation (r = .70, N = 26, P less than .001) between serum iCT and serum calcium. These observations suggest that the increased serum iCT in these subjects was a response to slight elevations in serum calcium, which are the result of normal physiological mechanisms to correct the renal phosphate leak.

Methods for assessing nutritional status of patients with renal failure

Since wasting and malnutrition are common problems in patients with renal failure, it is important to develop techniques for the longitudinal assessment of nutritional status. This paper reviews available methods for assessing the nutritional status; their possible limitations when applied to uremic patients are discussed. If carefully done, dietary intake can be estimated by recall interviews augmented with dietary diaries. Also, in a stable patient with chronic renal failure, the serum urea nitrogen (N)/creatinine ratio and the rate of urea N appearance reflect dietary protein intake. A comparison of N intake and urea N appearance will give an estimate of N balance. Anthropometric parameters such as the relationship between height and weight, thickness of subcutaneous skinfolds, and midarm muscle circumference are simple methods for evaluating body composition. Other methods for assessing body composition, such as densitometry and total body potassium, may not be readily applicable in patients with renal failure. More traditional biochemical estimates of nutritional status such as serum protein, albumin, transferrin, and selected serum complement determinations show that abnormalities are common among uremic patients. Certain anthropometric and biochemical measurements of nutritional status are abnormal in chronically uremic patients who appear to be particularly robust; thus, factors other than altered nutritional intake may lead to abnormal parameters in such patients. Serial monitoring of selected nutritional parameters in the same individual may improve the sensitivity of these measurements to detect changes. Standards for measuring nutritional status are needed for patients with renal failure so that realistic goals can be established optimal body nutriture.

Septic arthritis in hemodialyzed patients

Six episodes of septic arthritis involving 5 patients and eleven joints were documented in the last 7 years in a population receiving 450 patient-years of dialysis treatment. The same micro-organisms were often cultured simultaneously from the joint, blood and/or arteriovenous fistula, suggesting hematogenous spread. A tendency toward multiarticular involvement was also observed. Early diagnosis is mandatory to avoid severe joint damage. Since such patients have other potential causes of arthritis and periarticular pain not due to infection, it is important to culture the joint fluid promptly whenever the possibility of infection exists.

Methotrexate-induced renal failure and ineffectiveness of peritoneal dialysis

Acute renal failure developed in a 47-year-old man during the second course of a high-dose methotrexate sodium (MTX) treatment for chondrosarcoma of the pelvis with pulmonary metastasis. Uninterrupted peritoneal dialysis for seven days had a negligible effect on plasma MTX. Although high-dose leucovorin calcium prevented severe myelosuppression and mucositis, the patient died 12 days after receiving MTX. Renal histological studies showed severe tubulointerstitial damage consistent with MTX toxicity. Better alternatives for removing MTX in patients with renal failure are clearly needed.

The assay of 1alpha,25-dihydroxyvitamin D3: physiologic and pathologic modulation of circulating hormone levels

A sensitive radioreceptor assay for 1alpha,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3) is utilized to quantitate the circulating concentration of this sterol in experimental animals and humans. When weanling rats are grown for 2 weeks on low calcium or low phosphate diets, limited availability of either ion elicits a five-fold increase in the plasma level of 1alpha,25-(OH)2D3. The enhancement of 1alpha,25-(OH)2D3 in calcium deficiency is dependent upon the presence of the parathyroid and/or thyroid glands, which is consistent with parathyroid hormone (PTH) mediation of this effect. In contrast, the response to phosphate deficiency is independent of these glands and may result from a direct action of low phosphate on the renal synthesis of 1alpha,25-(OH)2D3. Studies in humans indicate that the normal level of 1alpha,25-(OH)2D is 2.1--4.5 ng/100 ml plasma. Patients with chronic renal failure have markedly lower circulating 1alpha,25-(OH)2D and this kidney hormone is undetectable in anephric subjects, but returns to normal within 1 day after successful renal transplantation. Hypoparathyroidism and pseudohypoparathyroidism are associated with reduced plasma 1alpha,25-(OH)2D while patients with primary hyperparathyroidism have significantly elevated sterol hormone levels. Thus, from measurements in rats and humans, it appears that circulating 1alpha,25-(OH)2D3 is regulated by PTH and/or phosphate and that abnormal plasma 1alpha,25-(OH)2D3 is a part of the pathophysiology of renal osteodystrophy and parathyroid disorders.

Vitamin D intoxication in an anephric child

Although the biologically active metabolite of vitamin D, 1,25-dihydroxycholecalciferol, is synthesized exclusively by kidney tissue, severe hypercalcemia developed in an anephric child treated with large doses of vitamin D. Treatment by calcium-free peritoneal dialysis acutely reduced serum calcium from 17.2 to 14.2 mg/100 ml. This decrement was effected by removal of three times the total calcium in extracellular fluid, suggesting enhanced bone resorption. Oral prednisolone for 7 days reduced serum calcium to 13 mg/100 ml, but hypercalcemia recurred rapidly after prednisolone was stopped. Calcitonin, given for only 4 one-half days, produced normocalcemia. Maximum serum 25-hydroxyvitamin D (25-OHD), observed immediately after vitamin D was stopped, was 635 ng/ml (normal range 23-32 ng/ml) and subsequently decreased with an initial half-time of 10 days. Losses in peritoneal dialysate may have contributed to disappearance of serum 25-OHD. Because of the high serum levels of 25-OHD and absence of renal tissue, 25-OHD was the likely metabolite that caused hypercalcemia, probably by stimulation of bone resorption, though contribution to hypercalcemia by another vitamin D metabolite cannot be absolutely excluded.