[Research progress on health hazards of oil mist]

Metal working fluidis widely used as coolant, lubricant and rust remover in mechanical processing. Oil mist will be formed in the process of metal working fluid. The composition of oil mist is complex, which can produce many adverse effects on the environment and operators. This paper reviews the health hazards of metal working fluid oil mist on human skin, respiratory system, teratogenic and carcinogenic aspects, and discusses the establishment of occupational exposure limits in workplaces of oil mist in foreign countries, in order to provide reference for the prevention and control of occupational health risks of metal working fluid oil mist and the establishment of occupational exposure limits of oil mist in workplaces in China.

[The application of rapid rehabilitation model of multidisciplinary cooperation in cesarean section and the evaluation of health economics]

Objective: To explore the application value of multiple disciplinary team Enhanced recovery after surgery (MDT-ERAS) in cesarean section and evaluate its health economic benefits. Methods: A total of 572 cases of pregnant women undergoing cesarean section in obstetrics department of Jiaxing Maternity and Child Health Care Hospital from March 2018 to March 2019 were selected and randomly divided into experimental group and control group, 286 cases in each group. The control group was treated with traditional rehabilitation mode, and the experimental group was treated with MDT-ERAS intervention to compare the difference of rehabilitation index and health economics index between the two groups, and to evaluate the application value and health economics benefit of MDT-ERAS. Results: The VAS scores of the two groups at 1 day after operation were higher than those at the time of returning to the ward after operation(1.81±0.40 VS. 1.58±0.39, 3.78±0.89 VS. 3.22±0.83, all P<0.05). The VAS scores at 2 days and 3 days after operation were lower than those at the time of returning to the ward(0.58±0.09 VS. 1.58±0.39, 1.02±0.15 VS. 1.58±0.39; 1.88±0.37 VS. 3.22±0.83, 2.67±0.44 VS. 3.22±0.83, all P<0.05). The VAS scores of the experimental group at each time point after operation were lower than those of the control group(1.58±0.39 VS. 3.22±0.83, 1.81±0.40 VS. 3.78±0.89, 1.02±0.15 VS. 2.67±0.44, 0.58±0.09 VS. 1.88±0.37), and these differences were statistically significant (P<0.05). The anal exhaust time, indwelling catheterization time, first time out of bed and first time eating time of the experimental group were lower than those of the control group, with statistical significance (P<0.05). Postpartum hemorrhage rate and neonatal milk addition rate in the experimental group were significantly lower than those in the control group (all P<0.05). The hospitalization time and hospitalization expenses of the experimental group were lower than those of the control group(all P<0.05), and the health economics benefit of the experimental group was significantly higher than that of the latter (P<0.05). Conclusion: MDT-ERAS can effectively improve the recovery rate of the parturient after cesarean section, ensure the analgesic effect and improve the maternal and infant outcomes, and has higher health and economic benefits, which is worthy of promotion.

[Value of heart rate as an optimum index in evaluating physical labor intensity]

Objective: To investigate the possibility of heart rate as an optimum index for evaluating physical labor intensity. Methods: From September to October, 2015, a total of 111 male young adults were selected as study subjects. A cycle ergometer was used for exercise at different intensities (20, 40, 60, 80, 100, 120, 140, 160, and 180 W) , and the exercise at each intensity lasted for 6 minutes. The subjects wore the K4b2 portable cardiopulmonary function testing instrument for the real-time monitoring of heart rate (HR) , pulmonary ventilation volume (Ve) , oxygen consumption (VO(2)) , and energy metabolic rate (E) . The origin software was used for correlation and regression analyses of HR, Ve, VO(2), and E collected at different intensities to establish Ve-HR, VO(2)-HR, and E-HR regression equations. Results: At different intensities, HR was positively correlated with Ve, VO(2), and E (r=0.8985, 0.8733, and 0.8973, all P<0.01) . There was a significant difference in the R(2) value of Ve-HR, VO(2)-HR, and E-HR regression equations (R(2)=0.8070, 0.7625, and 0.8049, all P <0.01) . The validation results showed that there was no significant difference between the calculated values and the measured ones (P>0.05) . Conclusion: HR can replace Ve, VO(2), and E and be used as an optimum index for evaluating physical labor intensity.

LECT2 association with macrophage-mediated killing of Helicobacter pylori by activating NF-κB and nitric oxide production

Helicobacter pylori employs unique methods to colonize the stomach, which induces chronic inflammation. It is also able to avoid eradication by macrophages and other immune cells. Leukocyte cell-derived chemotaxin 2 (LECT2), a multi-functional cytokine involved in many pathological conditions, has recently been shown to activate macrophages via the CD209a receptor. Therefore, we aimed to investigate the effects of LECT2 on H. pylori-infected macrophages. Macrophages were treated with recombinant LECT2, and both their ability to kill H. pylori and produce nitric oxide were analyzed. Western blot was performed to determine nuclear translocation and protein phosphorylation of p65, a subunit of nuclear factor (NF)-κB. Transfection experiments were performed to analyze the signaling pathway of LECT2 in macrophages. We found that treatment with LECT2 enhanced H. pylori killing and nitric oxide production in macrophages. In addition, DNA-binding activity and nuclear translocation of p65 were up-regulated by LECT2 treatment. Furthermore, we found that NF-κB activation by LECT2 was mediated by Raf-1 in macrophages, and Raf-1 phosphorylation was specifically altered in response to LECT2. Moreover, LECT2 induced Ser28 phosphorylation in the intracellular domain of CD209a. CD209a Ser28 phosphorylation was required for LECT2-induced Raf-1 and NF-κB activation in RAW264.7 macrophages. Our study showed that the effects of LECT2 on H. pylori killing and nitric oxide production were dependent on CD209a phosphorylation, Raf-1, and NF-κB activation. Together, these results demonstrate for the first time that exposure to LECT2 can modulate specific intracellular mechanisms downstream of CD209a to enhance H. pylori killing and nitric oxide production in macrophages.

Application of aluminium(III) complex with salicylidene-o-aminophenol to the fluorometric determination of nucleic acids

In buffer medium of hexamethylene tetraamine-HCl at pH 5.9 the aluminium(III) complex with salicylidene-o-aminophenol (SAP) has a fluorescence peak at 508 nm with excitation at 410 nm. When nucleic acid coexists, it reacts with the complex within 8 min at room temperature to produce a non-fluorescent product, resulting in the decrease of fluorescence intensity of the aluminium complex. On basis of this, a new fluorometric method for nucleic acids determination is proposed. The calibration graphs for calf thymus DNA, fish sperm DNA and yeast RNA are linear up to 5.0, 4.0 and 3.0 microg ml(-1), respectively, and corresponding detection limits are 49, 52 and 62 ng ml(-1). The synthetic samples are analyzed with relative standard deviation of five measurements of 3.9-6.0%. DNA in an extraction product from human blood is determined using the calibration graph for calf thymus DNA, and the result is very close to that by the ethidium bromide assay. Compared with some established fluorometric methods, this procedure is sensitive, selective, reliable, reproducible and practical. The association constant of calf thymus DNA with the complex is estimated by two graphic methods. It is suggested that the binding reaction between nucleic acids with the complex proceeds in an intercalation way.

A highly sensitive assay for protein using resonance light-scattering technique with dibromohydroxyphenylfluorone-molybdenum(VI) complex

At pH 2.8 and in the presence of 0.090% p-octylpolyethyleneglycol phenylether, the resonance light-scattering (RLS) spectrum of molybdenum(VI) complex with dibromohydroxyphenylfluorone (DBHPF) has a sharp peak at 586 nm. If the micro protein coexists with Mo(VI) and DBHPF, the RLS intensity of the complex at 586 nm is significantly enhanced by protein due to the binding interaction between protein and DBHPF-Mo(VI) complex. Based on this a new assay for protein is described. The dynamic ranges for bovine and human serum albumins are both 0.05-0.75 mg l-1 with detection limits of 13 and 15 ng ml-1, respectively. Besides high sensitivity, the method is characterized by good reproducibility, rapidity of reaction, good stability of chemical system, commonality of spectrofluorometer, few coexisting substances, especially detergents. The determinations of diluted human serum and urine by this method give the results very close to these by the Coomassie brilliant blue G-250 colorimetry, with relative standard deviations of five duplicates of 1.8-2.5%.

[Simultaneous determination of tyrosine and tryptophan in amino acid injection, animal and plant extracts by polarization spectrofluorimetry]

A new method for the simultaneous determination of tyrosine and tryptophan by polarization spectrofluorimetry has been developed. The interference of phenylalanine and light scattering of solvent were eliminated by using vertically crossed polarizers. The overlapping of fluorescence spectra of the two amino acids was solved with filters. The linear ranges of determination were 0.02-12.0 mg.L-1(tyrosine) and 0.01-2.50 mg.L-1(tryptophan). The mean recoveries of tyrosine and tryptophan in samples were 95.4% and 101.7% (in amino acid injection). 99.2% and 100.0% (in wild jujube kernel), 95.3% and 97.2% (in shrimp shell) respectively. The proposed method has been used to determine tyrosine and tryptophan in amino acid injection, extracts of wild jujube kernel and shrimp shells with satisfactory results.

Role of cysteine residues in the activity of rat glutathione transferase P (7-7): elucidation by oligonucleotide site-directed mutagenesis

To clarify the role(s) of thiol (sulfhydryl) groups of cysteine (Cys) residues in the activity of the rat glutathione transferase P (7-7) form (GST-P), a cDNA clone, pGP5, containing the entire coding sequence of GST-P (Y. Sugioka et al., (1985) Nucleic Acids Res. 13, 6044-6057) was inserted into the expression vector pKK233-2 and the recombinant GST-P (rGST-P) expressed in E. coli JM109. All four Cys residues in rGST-P were independently substituted with alanine (Ala) by site-directed mutagenesis, the resultant mutants as well as the rGST-P being identical to GST-P purified from liver preneoplastic nodules with regard to molecular weight and immunochemical staining. Since all mutants proved as enzymatically active towards 1-chloro-2,4-dinitrobenzene as liver GST-P, it was indicated that none of the four Cys residues is essential for GST-P activity. However, the mutant with Ala at the 47th position from the N-terminus (Ala47) became resistant to irreversible inactivation by 0.1 mM N-ethylmaleimide (NEM), whereas the other three mutants remained as sensitive as the nonmutant type (rGST-P). Ala47 was also resistant to inactivation by the physiological disulfides, cystamine or cystine, which cause mixed disulfide and/or intra- or inter-subunit disulfide bond formation. These results suggest that the 47-Cys residue of GST-P may be located near the glutathione binding site, and modulation of this residue by thiol/disulfide exchange may play an important role in regulation of activity.

Modulation of class Pi glutathione transferase activity by sulfhydryl group modification

Glutathione transferases (GSTs) in Class Pi (rat GST-P (7-7) and human GST-pi) were inactivated by treatment with 0.05-1 mM hydrogen peroxide (H2O2), while GSTs in Class Alpha (1-2) and Class Mu (3-3, 3-4) were not, even with 5 mM H2O2. In the presence of 1 mM reduced glutathione (GSH), the inactivated GST-P (-pi) was effectively reactivated by the action of thioltransferase, which had been partially purified from rat liver by GSH-Sepharose affinity chromatography and gel filtration using Sephadex G-75. Thus, inactivation of GST-P by H2O2 was indicated to involve concomitant formation of disulfide bonds between cysteinyl residues. Single GST-P or GST-pi subunits are known to have four cysteinyl residues at the same positions, which can react with sulfhydryl group modifiers. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, GST-P treated with 1 mM H2O2 showed several extra bands, at least three, with apparent molecular weights of 21.5, 18, 37 kDa in addition to the native GST-P subunit band with a molecular weight of 23.5 kDa. These extra bands were identified as inactive forms since they returned to the native band with accompanying restoration of the activity when treated with dithiothreitol, mercaptoethanol, or thioltransferase. Disulfide bonds were formed mainly within subunits, causing an apparent reduction in molecular weight, only small amounts of binding between subunits being observed.

The IVBF dual-blade plate and its applications

A recently developed simple device, the intervertebral body fixation dual-blade plate, was used in 88 cases of different spinal disorders. This patients in the first series were operated on from 1984 to 1986. The device is biomechanically simple and its application safe and easy. Using a proper bone grafting technique, it is a reliable device to establish spinal stability in spine surgery through an anterior approach. Its application in cases of fractures and fracture-dislocations of the thoracolumbar spine with paraplegia, tuberculous spondylitis, and primary tumors of vertebral bodies is presented. The midterm results, covering a follow-up period of 24-49 months (mean, 32 months) were satisfactory; there were no serious complications directly related to the device. There were four cases of pseudarthrosis due to insufficient bone graft technique. Of these, there were three cases of failure of the dual-blade plate.

[Clinical values of serum PGGT (pancreas gamma-glutamyltranstidase and PGGT/TGGT ratio in diagnosis of cancer of the head of pancreas]

737 samples of sera were determined for gamma-glutamyl transtidase Iscenzyme (PGGT). The samples were obtained from 121 healthy adults, forty pancreatic-head-cancer patients, and 576 patients with other hepato-biliary-pancreatic diseases. The positive rates of PGGT greater than 4u/l and PGGT/TGGT greater than 0.1 were 62.5% (25/40) in pancreatic-head-cancer patients, 27.02% (10/37) in patients with non-pancreatic extrahapatic-biliary-duct malignant obstructive jaundice, 1.21% (1/82) in patients with benign extrahepatic-biliary duct obstructive jaundice (biliary stones), 1.29% (1/77) in liver cancer patients, and 0% (0/380) in patients with other general surgical diseases, respectively. The positive rate of PGGT greater than 4u/L and PGGT/TGGT greater than 0.1 was significantly higher in patients with pancreatic head cancer than in patients with hepato-biliary-duct obstructive jaundice (including benign and malignant diseases) and liver cancer (x = 99.45, p less than 0.001). The study showed that the serum TGGT was mainly of hepatic origin, and its level was elevated in patients with pancreatic or/and biliary diseases, which resulted in the obstruction of the pancreatic duct and bile duct at the same time. Hence, the serum PGGT greater than 4u/L together with POGT/TGGT greater than 0.1 was mainly found in patients with pancreatic head cancer.