A novel anti-lipopolysaccharide factor SpALF6 in mud crab Scylla paramamosain exhibiting different antimicrobial activity from its single amino acid mutant.

In crustaceans, anti-lipopolysaccharide factors (ALFs) are important immune effectors that have sequence diversity and exhibit broad antimicrobial activities. In this study, we characterized a novel ALF homolog SpALF6 from mud crab Scylla paramamosain and its variant SpALF6-V, which was generated by mutations of two amino acids (H46 to R and A110 to P) due to the presence of two single nucleotide polymorphisms (SNPs). SpALF6 was an anionic peptide with isoelectric point (pI) 6.79, whereas SpALF6-V was a cationic protein with pI 7.98. These two proteins shared a common lipopolysaccharide (LPS)-binding domain (LBD) with pI 6.05. SpALF6 was expressed mainly in hemocytes and up-regulated by Vibrio parahaemolyticus or Staphylococcus aureus challenge, indicating that SpALF6 may participate in the antibacterial immune responses. To investigate the likely functional differences between SpALF6 and SpALF6-V and elucidate the underlying mechanisms, a single amino acid mutant SpALF6-M (from H46 to R, outside but very close to LBD), which had the same pI as SpALF6-V, was harvested by a fusion PCR. Then, both SpALF6 and SpALF6-M were overexpressed and purified to test antimicrobial activity and binding activity to microbial cells or polysaccharides. SpALF6-M exhibited more potent antimicrobial and cell-binding activity on Gram-positive bacteria and fungi than SpALF6. Furthermore, SpALF6-M possessed stronger lipoteichoic acid (LTA)-binding activity than SpALF6, demonstrating that this particular positively charged amino acid outside but close to LBD contributed to the increase in SpALF6-M antibacterial activity. In addition, SpALF6 LBD peptide and its biotin-labeled form were synthesized in this study. Results showed that this anionic LBD peptide itself did not exhibit any significant antimicrobial activity against 10 kinds of microorganisms but it possessed strong binding activity to LPS, LTA, and peptidoglycan. These findings suggested that this anionic LBD was still an important active center and required collaboration with some particular positively charged amino acids outside LBD to exhibit antibacterial activity. Thus, SpALF6-M antimicrobial activity was increased by the mutation of H46 to R instead of A110 to P, which did not change the protein charge, suggesting that SpALF6-V may have more potent antimicrobial activity than SpALF6 and play more important roles in antibacterial immunity. This study provided a new insight into the mechanisms of how ALF amino acid sequence diversity resulted in their functional divergence.

[Quality of life of inpatients with coal workers' pneumoconiosis and its influential factors].

OBJECTIVE: To investigate the quality of life ( QOL) of inpatients with coal workers' pneumoconiosis( CWP) and analyse its influential factors, and to provide a theoretical basis for effective control measures. METHODS: Eighty-eight CWP patients in a hospital were included in the study. A questionnaire survey was conducted in them using a self-designed QOL scale. A database was established by software EpiData3.1, and the obtained data were statistically analyzed by software SPSS 16.0. RESULTS: Of the 88 patients, 73( 82.9%) had middle-level QOL, with a mean QOL loss rate of 36.2%; the loss rates of physical function and somatic sensation were the highest ( 44.2% and 41.5%). The patients with stage II CWP had significantly lower physical function than those with stage I and III CWP; the physical function and social function of patients significantly decreased with age; the personal income, household income, and housing condition of the patients had a marked impact on their physical and psychological functions, and the housing condition and education level had a marked impact on their social function. The multivariate analysis showed that old age, low income,and poor housing condition were the main adverse factors for the QOL of inpatients with CWP. CONCLUSION: The QOL of inpatients with CWP declines significantly, and their QOL is related to the age, income, and satisfaction with housing condition.

[Studing the health status of workers occupationally exposed to carbon disulfide].

OBJECTIVE: To study the effects of carbon disulfide (CS(2)) on the health of workers, and to provide the basis for the further preventive measures. METHODS: The occupational health examination of 881 workers exposed to CS(2) in a chemical fiber factory was carried out according to the national technical standard of occupational health surveillance. The time weighted average concentrations (TWA) of CS(2) in the workshops of short silk and long silk exceeded the national standard, The workers in these two workshops served as the high exposure group. The workers of the other workshops were classified as low exposure group, in which TWA met the national standard. All exposed workers were also divided into long-term exposure group and short-term exposure group on the basis of average exposure years (16 years). The statistical analysis was used by t test, χ(2), and fisher exact test. RESULTS: The symptom rates of numbness, fatigue, dizziness, insomnia and headache were 12.5%, 8.5%, 8.2%, 7.5%, and 7.2% respectively. The abnormal rates of superficial sensation, three fibrillation, achilles tendon reflex, patellar reflex, EMG, hypertension, triglycerides, low-density lipoprotein, and apolipoprotein B were 33.0%, 26.1%, 20.8%, 18.6%, 10.8%, 33.4%, 24.5%, 17.0% and 9.3% respectively. Among the high exposure group, the abnormal detectable rates of dizziness, headache, fatigue, insomnia, numbness, achilles tendon reflex, superficial and deep sensation, EMG, hypertension, ECG, total cholesterol, triglyceride and low density lipoprotein in long-term exposure group were significantly higher than those in short-term exposure group (P < 0.05 or P < 0.01). However, among the low exposure group, the abnormal rates of the insomnia achilles tendon reflex and superficial sensation in long term exposure group were significantly higher than those of short term exposure group (P < 0.05 or P < 0.01). The detected rates of hypertension, triglycerides, low-density lipoprotein, creatinine and uric acid were in males significantly greater than those in females (P < 0.05 or P < 0.01). CONCLUSION: Long-term exposure to high concentrations of CS(2) could lead to the damage of nervous system, elevate blood pressure and promote the development and progression of hyperlipemia and atherosclerosis. Furthermore, CS(2) had greater effects on blood pressure and lipid in males than in females.

[Clinical characteristics of the patients with occupational chronic carbon disulfide poisoning in a chemical fiber factory of Nanjing].

OBJECTIVE: To analyze the clinical characteristics of 267 cases with occupational chronic carbon disulfide (CS(2)) poisoning and to provide the basis for revising the items of periodical medical examination of workers occupationally exposed to CS(2). METHODS: The subjects of present study were 267 patients with mild CS(2) poisoning diagnosed according to "Diagnostic Criteria of Occupational Chronic Carbon Disulfide Poisoning (GBZ4-2002)" from April in 2006 to May in 2010. All patients were from the same chemical fiber factory. When a subject was diagnosed as patient with CS(2) poisoning, who should interview with questionnaire which included the illness and occupational history, symptoms, individual habits. The physical examination, nervous test, cardiovascular test, biochemical test and electromyogram were performed. RESULTS: The rate of decreased motor conduction velocity was 87.3% (233/267 roots). The highest detection rate of slowing conduction velocity was the common peroneal motor nerve which was 48.6% (138/248 roots) and the second was median motor nerve with delay rate of 37% (155/419 roots). The main symptoms of the patients were neurasthenia, numbness and paresthesia. The rates of abnormal achilles tendon reflex and knee jerk reflex in patients were were 79.4% and 49.8%, respectively. The detected rates of patients with ST-segment changes and hypertension were 19.1% and 27.5%, respectively. The rates of hypertension, systolic pressure and diastolic pressure were 27.3%, 22.5% and 21.1%, respectively. The rates of lactate dehydrogenase (LDH), triglycerides (TG) and low density lipoprotein (LDL) were high. The detected rates of urine acid, indirect bilirubin and total bilirubin in male patients were higher than those in female patients. In addition, the abnormal detected rate of urea nitrogen and indirect bilirubin increased with exposure years. CONCLUSION: Occupational chronic CS(2) poisoning mainly affects the nervous system, as well as liver and kidney function. Detecting the median and common peroneal motor nerve conduction velocities could be the screening indicators for the peripheral nerve injury induced by CS(2) in the occupational exposure population during the periodical occupational medical examinations.

[Annexin A5 gene polymorphism (-1C/T) and the susceptibility to pneumoconiosis in coal works].

OBJECTIVE: To explore the role of -1C/T single nucleotide polymorphism within Annexin A5 gene in the genetic susceptibility to coal worker's pneumoconiosis (CWP). METHODS: Four hundred and seventy CWP Han chinese patients and 428 Han chinese controls were enclosed in present case-control study. All subjects were exposed to coal dusts. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the -1C/T SNP in Annexin A5 gene for all subjects. The relationship between the -1C/T SNP in Annexin A5 gene and CWP was analyzed. RESULTS: CT/TT genotype in -1C/T SNP was associated with a significantly decreased risk of CWP, as compared with the CC genotype among subgroups exposed to coal dusts for ≥ 27 years (adjusted OR = 0.65, 95%CI: 0.44 - 0.98, P = 0.039) and patients with CWP at stage II (adjusted OR = 0.55, 95%CI: 0.34 - 0.90, P = 0.028). CONCLUSION: The results of present study suggest that the Annexin A5 -1C/T polymorphism may be involved in the development of CWP in Han Chinese coal miners.

[Silica induced α-SMA expression in HBE cell line by targeting the PI3K/Akt pathway].

OBJECTIVE: To explore the role of the phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway in silica-induced α-SMA (α smooth muscle actin) expression in HEB (human bronchial epithelial) cell. METHODS: The cultured HBE cells were divided into 5 groups: control, silica, PI3K inhibitor (Ly294002), both PI3K inhibitor (Ly294002) and silica at the same time and the inhibitor 24 h ahead of silica. The final concentrations of PI3K inhibitor and silica were 10 µmol/L and 100 µg/ml, respectively. Western blots were used to detect protein expressions of Akt, p-Akt, TGF-ß and α-SMA. The location and expression of α-SMA were measured by immunofluorescence assay. RESULTS: HBE cell line exposed to silica can induce Akt phosphorylation, in which expressions of p-Akt were up regulated 1 times at 48 and the highest at 72 h. The expressions of TGFß increased remarkably at 12 h and the peak at 48 h after silica exposure, while the expressions of α-SMA increased at 24 h and the highest at 72 h. However, the PI3K inhibitor (Ly294002) significantly down regulated α-SMA expression. When the cell line exposed to the PI3K inhibitor ahead of silica 24 h, the expressions of p-Akt and α-SMA were more remarkably down regulated which were decreased 1.5 times and 7.6 times respectively compare to silica exposure group. But no significant changes were found for TGFß expressions. The immunofluorescence assay showed that silica can induce α-SMA expression, which located in cytoplasma, and PI3K inhibitor can decrease the expression. CONCLUSIONS: Silica induced α-SMA expression in HBE cell line is by targeting the PI3K/Akt pathway and PI3K inhibitor can repress α-SMA expression.

[The analyses on dust pollution of one underground iron mine from 1991 to 2010].

OBJECTIVE: The main purpose of this work was to give the evidence of reasonable and feasible dust control measures which will be taken in the future by analyzing the trend of dust concentration from 1991 to 2010 and identifying working faces with the severe dust contamination in one underground iron mine. METHODS: The data was from routine monitoring between the years 1991 and 2010, which enclosed the total dust concentrations and silica contents. China National Standard of Occupational exposure limits for hazardous agents in the workplace used to judge whether the dust concentration exceeded the National Standard. RESULTS: The general trend of total dust concentration from 1991 to 2010 was decreased, especially maximum and average levels. The highest exceeding rate was 43.16% in 1993 and the best years were 2009 and 2010, but the exceeding rates were still over 30%. The dust exposure levels varied with different work faces. The mining and supporting were the most severe dust pollution faces which the highest ultra exceeding rates were 51.61% and 51.48% and the maximum exceeding times were 64.6 and 16.4 respectively. The next was constructing face with 40.23% exceeding rate and 24.6 times more than standard. CONCLUSION: The trend of total dust concentration from 1991 to 2010 was decreased, but the dust exceeding rate was still high. The strong measures should be taken to control the dust pollution in this iron mine, especially mining and supporting faces.