[A survey of cervical and lumbar spine diseases of express delivery employees].

Objective: To understand the current situation and influencing factors of cervical and lumbar spine diseases of the express delivery employees, and provide scientific basis for carrying out their occupational health protection in a targeted manner. Methods: From February 2020 to January 2021, the current situation research method was used to obtain 527 express delivery employees by cluster sampling. Online questionnaires were used to investigate sociodemographic characteristics and emotional characteristics, and clinical data were obtained by digital X-ray (DR) examination of the neck and waist. Pearson χ(2) test and multivariate logistic regression were used to analyze the influencing factors of cervical and lumbar spine diseases in express delivery employees. Results: The prevalence rates of cervical spine and lumbar spine diseases among express delivery employees were 49.15% (259/527) and 67.74% (357/527) , respectively. Univariate analysis showed that there were statistically significant differences in the distribution of cervical and lumbar spine disease among express delivery employees with different ages, length of service, working hours per week, and different degrees of distress due to emotional factors (P<0.05) . Multivariate analysis showed that express delivery employees aged ≥25 years old had a higher risk of cervical spine disease (P<0.05) , the express delivery employees who worked 49-55 hours per week had a lower risk of cervical spine disease (P<0.05) . Express delivery employees aged≥35 years old had a lower risk of lumbar spine disease (P<0.05) , and the risk of lumbar spine disease was higher among express delivery workers who suffered moderate or more distress due to emotional factors (such as anxiety, depression, or irritability) in the past 4 weeks (P<0.05) . Conclusion: The prevalence of cervical and lumbar spine diseases is relatively high among express delivery employees. It is recommended to adjust the weekly working hours of express delivery employees, organize psychological counseling training, and effectively protect the occupational health rights of express delivery employees.

[Investigation on occupational injury of sanitation workers in Shenzhen City].

Objective: To understand the occurrence of occupational injuries among sanitation workers in Shenzhen, and provide a scientific basis for the prevention of occupational injuries among sanitation workers. Methods: From May to November 2020, a cluster sampling method was used to select some street sanitation workers in Shenzhen to conduct a questionnaire survey. A total of 2200 questionnaires were recovered, of which 2167 were valid (98.5% effective recovery rate) . The socio-demographic data, length of service, type of work and occurrence of occupational injuries of sanitation workers were collected, and the distribution characteristics of occupational injuries and their relationship with factors such as type of work were analyzed. Results: Among the 2167 sanitation workers, 240 (11.1%) had experienced occupational injuries. The most common occupational injuries among sanitation workers were sharp injury, heat stroke and motor vehicle traffic accident, with the incidence rates of 6.1% (133/2167) , 2.4% (53/2167) and 1.7% (36/2167) respectively. There were statistically significant differences in the distribution of occupational injuries among sanitation workers with different lengths of work and types of work (P<0.05) . The incidence of occupational injury among sanitation workers with more than 5 years of service was significantly higher than that of workers with less than 5 years of service (P<0.05) . The incidence of sharp injury among garbage sorting and transportation personnel was higher (7.9%, 21/265) , the incidence of heat stroke among manual cleaners was higher (3.1%, 42/1366) , and the incidence of motor vehicle traffic accident among mechanized cleaners was higher (5.4%, 10/184) . Conclusion: There are many cases of occupational injuries among sanitation workers in Shenzhen. Targeted measures should be taken to prevent the occurrence of different types of work and different types of occupational injuries, and to improve the occupational health level of sanitation workers.

[Efficacy analysis on laparoscopic simultaneous resection of primary colorectal cancer and liver metastases].

Objective: To investigate the short-term outcomes of laparoscopic simultaneous resection of primary colorectal cancer and liver metastases in patients with resectable synchronous colorectal liver metastases (SCRLM). Methods: A descriptive case series study was performed. Clinicopathological data of patients with SCRLM who underwent laparoscopic simultaneous resection of colorectal cancer and liver metastases in Zhongshan Hospital between December 2015 and September 2018 were retrieved from a prospective colorectal cancer database. Perioperative presentations and short-term outcomes were analyzed. Results: A total of 53 patients were enrolled with average age of(61.7±11.3) years. Among them, 32 were male (60.4%) and 21 were female (39.6%). Twenty-five patients (47.2%) were American Society of Anesthesiologists (ASA) grade I and 28 (52.8%) were grade II. All the patients completed laparoscopic simultaneous resection without conversion. The average operation time was (320.2±114.5) min. The estimated blood loss was 150.0 (45.0-2000.0) ml, and only 2 cases (3.8%) received intraoperative transfusion. Postoperative pathologic results revealed that the average primary tumor size was (5.4±1.9) cm; 4 cases (7.5%) were T1-2 stage and 48 cases (90.6%) were T3-4 stage; 40 patients (75.5%) had lymph node metastasis; 19 (35.8%) had vascular involvement; 24 (45.3%) had neural invasion. The median number of liver metastases was 1.0 (1-8), and the average size of largest liver metastases was (3.0±1.9) cm. The median margin of liver metastases was 1.0 (0.1-3.5) cm, and only 1 case was R1 resection. The average time to the first postoperative flatus was (67.9±28.9) h, and the average time to the liquid diet was (107.0±33.8) h. The average postoperative indwelling catheterization time was (85.6±56.4) h. The average postoperative hospital stay was (9.2±4.4) d, and the average cost was (82±26) thousand RMB. No death within postoperative 30-day was found. The morbidity of postoperative complication was 32.1% (17/53) and 3 patients developed grade III to IV complications which were improved by conservative treatment. The median follow-up period was 23.2 months. During follow-up, 19 patients (35.8%) developed recurrence or metastasis, and 4 (7.5%) died. The 1- and 2-year disease-free survival (DFS) rates were 68% and 47% respectively, and the 1- and 2-year overall survival rates were 95% and 86% respectively. Conclusions: Laparoscopic simultaneous resection of primary colorectal cancer and liver metastases is safe and feasible in selected patients with SCRLM. Postoperative intestinal function recovery is enhanced, and morbidity and oncological outcomes are acceptable.

[Risk factors of anastomotic leakage after robotic surgery for low and mid rectal cancer].

Objective: To investigate the risk factors associated with anastomotic leakage after robotic surgery in mid-low rectal cancer. Methods: A retrospective case-control study method was conducted. Inclusion criteria: (1) 18 to 80 years old; (2) pathologically confirmed rectal cancer; (3) distance <10 cm from tumor to anal margin; (4) robotic anterior rectal resection. Patients with previous history of colorectal cancer surgery, distant metastases or other malignant tumors, undergoing emergency surgery, with severe abdominal adhesions or those receiving combined organ resection were excluded. Based on the above criteria, 636 patients undergoing robotic radical sphincter-preserving surgery for mid-low rectal cancer in Zhongshan Hospital from January 2015 to December 2018 were included in this study, including 398 males (62.6%) and 238 females (37.4%) with a mean age of (61.9±11.3) years. Sixty-eight cases (10.7%) received neoadjuvant chemoradiotherapy. Amony the 636 included patients, 123(19.3%) underwent natural orifice specimen extraction surgery (NOSES) and 15 (2.3%) underwent preventive stoma. According to the cirteria developed by the International Rectal Cancer Research Group in 2010, the anastomotic leakage was classified as grade A (no requirement of intervention), B (requirement of intervention), and C (requirement of operation). Logistic regression was used to analyze the relationship between anastomotic leakage and clinicopathological factors. Factors in univariate analysis with P<0.05 were included in the multivariate analysis. Results: Anastomotic leakage occurred in 38 cases (6.0%). The grading of anastomotic leakage was grade A in 13 cases (2.0%), grade B in 19 cases (3.0%), and grade C in 6 cases (0.9%). The 3-year disease-free survival rate of patients with anastomotic leakage and without anastomotic leakage was 83.5% and 83.6% respectively (P=0.862); the 3-year overall survival rate of the two group was 85.1% and 87.5% respectively (P=0.296). The results of univariate logistic regression analysis showed that male (P=0.011), longer operation time (P=0.042), distance ≤5 cm from tumor to anal margin (P=0.012), more intraoperative blood loss (P=0.048) were associated with anastomotic leakage (all P<0.05). NOSES was not associated with anastomotic leakage (P=0.704). Multivariate analysis confirmed that male (OR=3.03, 95%CI: 1.37 to 7.14, P=0.010), operation time ≥180 minutes (OR=2.04, 95%CI: 1.03 to 3.99, P=0.040), distance ≤5 cm from tumor to anal margin (OR=2.56, 95%CI:1.28 to 5.26, P=0.008) were independent risk factors for anastomotic leakage. Conclusion: Male, short distance from tumor to anal margin, and long operation time are independent risk factors for anastomotic leakage in patients undergoing robotic mid-low rectal cancer radical surgeries. These patients need to be cautiously treated during surgery.

TRPV1 antagonists that cause hypothermia, instead of hyperthermia, in rodents: Compounds' pharmacological profiles, in vivo targets, thermoeffectors recruited and implications for drug development.

AIM: Thermoregulatory side effects hinder the development of transient receptor potential vanilloid-1 (TRPV1) antagonists as new painkillers. While many antagonists cause hyperthermia, a well-studied effect, some cause hypothermia. The mechanisms of this hypothermia are unknown and were studied herein. METHODS: Two hypothermia-inducing TRPV1 antagonists, the newly synthesized A-1165901 and the known AMG7905, were used in physiological experiments in rats and mice. Their pharmacological profiles against rat TRPV1 were studied in vitro. RESULTS: Administered peripherally, A-1165901 caused hypothermia in rats by either triggering tail-skin vasodilation (at thermoneutrality) or inhibiting thermogenesis (in the cold). A-1165901-induced hypothermia did not occur in rats with desensitized (by an intraperitoneal dose of the TRPV1 agonist resiniferatoxin) sensory abdominal nerves. The hypothermic responses to A-1165901 and AMG7905 (administered intragastrically or intraperitoneally) were absent in Trpv1-/- mice, even though both compounds evoked pronounced hypothermia in Trpv1+/+ mice. In vitro, both A-1165901 and AMG7905 potently potentiated TRPV1 activation by protons, while potently blocking channel activation by capsaicin. CONCLUSION: TRPV1 antagonists cause hypothermia by an on-target action: on TRPV1 channels on abdominal sensory nerves. These channels are tonically activated by protons and drive the reflectory inhibition of thermogenesis and tail-skin vasoconstriction. Those TRPV1 antagonists that cause hypothermia further inhibit these cold defences, thus decreasing body temperature. SIGNIFICANCE: TRPV1 antagonists (of capsaicin activation) are highly unusual in that they can cause both hyper- and hypothermia by modulating the same mechanism. For drug development, this means that both side effects can be dealt with simultaneously, by minimizing these compounds' interference with TRPV1 activation by protons.

[Surgical treatment of colorectal liver metastases].

Surgical resection of the metastases offers the only opportunity for long-term survival in colorectal liver metastases. However, only 10% to 20% of patients present with resectable disease, and so how to increase surgical patients has been a clinical hotspot. In addition to expanding surgical indications, two-stage hepatectomy and convertible therapy are optional. In convertible therapy, initial treatment regimen decides long-term benefit, and it is important to select appropriate patient population in addition to Ras status when anti-epithelial growth factor receptor monoclonal antibody is used. Minimally invasive surgery can also be used for liver resection and simultaneous resection, and it is safe and effective. For patients with colorectal cancer and unresectable asymptomatic liver metastases, the debate continues over the efficacy of primary resection compared to chemotherapy alone, limited by lack of prospective evidence. Therefore, multidisciplinary team assessment is essential to optimize outcomes in colorectal liver metastases.

[Features of peripheral nerve injuries in workers exposed to vibration: an analysis of 197 cases].

Objective: To investigate the features of peripheral nerve injuries in workers exposed to vibration. Methods: A total of 197 male workers [median age: 34 years (21-50 years) ; median working years of vibration exposure: 7.3 years (1-20 years) ] engaged in grinding in an enterprise were enrolled. Their clinical data and electromyography results were analyzed to investigate the features of peripheral nerve impairment. Results: Of all workers, 96 (48.73%) had abnormal electromyography results. Of all workers, 88 (44.7%) had simple mild median nerve injury in the wrist, who accounted for 91.7% (88/96) of all workers with abnormal electromy-ography results. Six workers had ulnar nerve injury, superficial radial nerve injury, or/and superficial peroneal nerve injury and accounted for 6.3% of all workers with abnormal electromyography results. Of all workers, 88 had a reduced amplitude of median nerve sensory transduction, and 28 had slowed median nerve sensory transduction. A total of 46 workers were diagnosed with occupational hand-arm vibration disease and hospitalized for treatment. They were followed up for more than 4 months after leaving their jobs, and most of them showed improvements in neural electromyography results and returned to a normal state. Conclusion: Workers exposed to vibration have a high incidence rate of nerve injury in the hand, mainly sensory function impairment at the distal end of the median nerve, and all injuries are mild peripheral nerve injuries. After leaving the vibration job and being treated, most workers can achieve improvements and return to a normal state.

Expression of anti-neuroexcitation peptide (ANEP) of scorpion Buthus martensii Karsch in Escherichia coli.

According to the cDNA sequence of anti-neuroexcitation peptide of scorpion Buthus martensii Karsch, the putative mature anti-neuroexcitation peptide (ANEP) encoding DNA fragment was obtained by a PCR method, then was cloned into expression plasmid pET28a, fused with His tag at its 3' end. When expressed in E. coli BL21 (DE3), the expression of recombinant ANEP was 15% of total cellular proteins, while most recombinant ANEP products existed in the form of insoluble inclusion bodies. Coexpression of molecular chaperones or protein disulfide isomerase could not improve its solubility. The recombinant ANEP in the cell lysate was purified to homogeneity by metal chelating affinity chromatography and Superdex 30 chromatography. In bioassay with convulsive mice model induced by thiosemicarbazide, recombinant ANEP could apparently delay the convulsion seizure of model animals by 18% and showed anti-neuroexcitatory activity.

Effects of rhM-CSF expressed in silkworm on cytokine productions and membrane molecule expressions of human monocytes.

AIM: To study the effects of recombinant human macrophage colony-stimulating factor (rhM-CSF) expressed in silkworm on cytokine productions and membrane molecule expressions of monocytes. METHODS: The rhM-CSF was added to the human peripheral blood monocyte cultures and 3 d later, the culture supernatants and cells were collected, respectively. TNF-alpha, IL-6, IL-8, and IFN-alpha levels in the supernatants were detected by biological activity test or ELISA and expressions of CD11b, CD16, HLA I, and HLA II on the cellular surface were examined by the method of alkaline phosphatase anti-alkaline phosphatase complex (APAAP). RESULTS: The rhM-CSF promoted TNF-alpha, IL-6, and IL-8 inductions of monocytes and increased the percentages of CD11b, CD16, HLA I, and HLA II molecule expression on monocytes. CONCLUSION: The rhM-CSF plays a role in monocyte function up-regulation and has a certain practical value in immunological therapy.

ATP-sensitive potassium channels regulate in vivo dopamine release in rat striatum.

ATP-sensitive K+ channels (K(ATP)) are distributed in a variety of tissues including smooth muscle, cardiac and skeletal muscle, pancreatic beta-cells and neurons. Since K(ATP) channels are present in the nigrostriatal dopamine (DA) pathway, the effect of potassium-channel modulators on the release of DA in the striatum of conscious, freely-moving rats was investigated. The extracellular concentration of DA was significantly decreased by the K(ATP)-channel opener (-)-cromakalim but not by diazoxide. (-)-Cromakalim was effective at 100 and 1000 microM concentrations, and the maximum decrease was 54% below baseline. d-Amphetamine significantly increased extracellular DA levels at the doses of 0.75 and 1.5 mg/kg, s.c. with a 770% maximum increase. (-)-Cromakalim had no effect on d-amphetamine-induced DA release, while glyburide, a K(ATP) blocker, significantly potentiated the effects of a low dose of d-amphetamine. These data indicate that K+ channels present in the nigrostriatal dopaminergic terminals modulate basal release as well as evoked release of DA.

Drug allergy: identification and characterization of IgE-reactivities to aspirin and related compounds.

Twenty-seven patients with aspirin (ASA) sensitivity were studied. 14 patients had naso-ocular-bronchial reactions after taking ASA while others had cutaneous and gastrointestinal reactions. The oral challenges with salicylic acid (SA), O-methylsalicylic acid (OMSA), ASA, and the determination of IgE antibodies specific to salicyloyl, O-methylsalicyloyl, acetylsalicyloyl using correspondent disks by RAST, RAST inhibition and RAST crossinhibition assays were performed. The findings suggest that OMSA seems to be the main offender responsible for cutaneous and gastrointestinal reactions, whereas ASA is responsible for naso-ocular-bronchial reactions. The clinical crossreactions between ASA and ASA-like drugs (nonsteroidal anti-inflammatory drugs and pyrazolone drugs) are probably due to "inborn errors of metabolism". The results indicate that genetic factors, mast-cell heterogeneity, and the interindividual variability in drug metabolism, combined with immunological background should be considered as underlying mechanisms.

Enhancement of in vitro renaturation of recombinant human pro-urokinase by ampicillin.

Ampicillin was used in in vitro renaturation process of recombinant human prourokinase and it can obviously improve the yield of the renaturation, although not as well as arginine. When ampicillin was used together with arginine or lysine, it decreased the yield of the renaturation comparing with the yield when arginine or lysine used alone.

A low molecular weight urokinase derivative with enhanced fibrin affinity.

A Gly-Pro-Arg-Pro tetrapeptide, homologous to amino-terminal segment of the human fibrin alpha chain after the release of the fibrinopeptide A, was covalently coupled to peptide A of low molecular weight urokinase. The resulting derivative gained increased affinity for fibrin. In caseinolytic assay, fibrin can stimulate the derivative to activate plasminogen. The derivative had two-fold greater fibrinolytic potency than native low molecular weight urokinase and its affinity for fibrin clot was 3.9-fold higher than that of low molecular weight urokinase.

Chemical conjugation of Gly-Pro-Arg-Pro. Tetrapeptide to low molecular weight urokinase.

Two low molecular weight urokinase derivatives were obtained by covalent coupling of a synthetic Gly-Pro-Arg-Pro tetrapeptide to peptide A of low molecular weight urokinase and exchanging the native peptide A of low molecular weight urokinase with Gly-Pro-Arg-Pro-peptide A to obtain derivative I or direct conjugation of Gly-Pro-Arg-Pro tetrapeptide to low molecular weight urokinase to obtain derivative II. In caseinolytic assay, fibrin can stimulate the two derivatives to activate plasminogen. But the two derivatives showed different kinetic behaviors. The derivative I displayed immediate onset of lysis and derivative II displayed a lag phase.

Characterization of a recombinant chimeric plasminogen activator composed of Gly-Pro-Arg-Pro tetrapeptide and truncated urokinase-type plasminogen activator expressed in Escherichia coli.

A chimeric plasminogen activator, GPRP-u-PA (144-411), consisting of the Gly-Pro-Arg-Pro tetrapeptide fused to the N-terminal of a truncated urokinase-type plasminogen activator (comprising Leu 144 through Leu 411), was produced by expression of the corresponding chimeric cDNA in Escherichia coli cells. After renaturation, the chimera was purified to homogeneity with specific amidolytic activity of 100,000 IU/mg protein. The chimera showed 6-fold greater affinity for fibrin clots than native low molecular weight urokinase (LUK) and 1.5-fold greater affinity than a chemical conjugate, GPRP-LUK, generating via coupling Gly-Pro-Arg-Pro tetrapeptide to native low molecular weight urokinase. The chimera had 2 to 3 fold greater fibrinolytic potency than native LUK in vitro. Fibrinogen had no influence on fibrinolysis of the chimera. The chimera consumed much less fibrinogen than native LUK.

Renaturation of recombinant human pro-urokinase expressed in Escherichia coli.

A synthetic gene encoding human pro-urokinase (pro-UK) with E. coli-favored codon usage was cloned into plasmid pET-3d and expressed in E. coli BL21(DE3) LysS strain. The expressed products, which accumulated as inactive inclusion bodies, were denatured and renatured in vitro. A broad range of parameters such as pH, protein concentration, denaturant concentration, the use of cosolvent polyethylene glycol and presence of basic or acidic amino acid was examined. At optimal renaturation condition, pro-UK activity of more than 1000I.U was obtained from 1 milliliter cell culture.

[The role of TNF-alpha in the growth and differentiation of U937 cells induced by PMA and IFN-gamma].

The effects of PMA and IFN-gamma on regulation of growth and differentiation of human monoblastic leukemic cell U937 were examined. U937 cells were stimulated by different concentrations of PMA and IFN-gamma respectively and NBT reduction assay was used to detect the differentiation of the cells. The results showed that both PMA and IFN-gamma dose-dependently induced differentiation of U937 cells into mature macrophage-like cells. The data also revealed a time-course response in the differentiation induction. Moreover, the U937 cell growth was significantly inhibited by the treatment of PMA and IFN-gamma. These results suggest that PMA and IFN-gamma coupled the regulation of U937 cell growth and differentiation. It was found that tumor necrosis factor-alpha (TNF-alpha) was expressed by the stimulated U937 cells. The specific monoclonal antibody against TNF-alpha diminished the effects of PMA and IFN-gamma on the growth and differentiation of U937 cells. Thus the endogenous TNF-alpha may involved in the mechanism of the effects of PMA and IFN-gamma on the differentiation of U937 cells. The regulatory action of the endogenous TNF-alpha on U937 cells was not due to its cytotoxic effect.

Synthesis and expression of a gene from kringle-2 domain of tissue plasminogen activator in E. coli.

The DNA fragment corresponding to the tissue plasminogen activator (tPA) sequence 174-262 (Kringle-2 domain) has been synthesized by using the solid phase phosphotriester method. The Kringle-2 domain of human tPA was expressed in Escherichia coli by secretion into the periplasmic space using the Lpp-Lac promoter and PIN-III OmpA2 signal sequence. About two thirds of the expression product was secreted into the periplasmic space, and purified with ammonium sulfate fractionation, affinity chromatography on Lysine-Sepharose, and FPLC-Mono Q exchange chromatography. The amino acid composition observed from the Kringle-2 purified from E. coli is identical with that expected for the 174-262 fragment of human tPA. Radio binding assay shows that the recombinant Kringle-2 domain possesses the activity of fibrin binding.

An efficient method for large-scale isolation of plasmid DNAs by heat-alkali co-denaturation.

A method is presented for efficient and large-scale isolation of plasmid DNAs from bacterial cells. Based on the cooperativity of heat and alkali actions, the method provides DNA preparations with high quality and yield (about 2 micrograms of DNA/ml culture), which are completely digestable by restriction enzymes and have a high transformation efficiency. Furthermore, the DNA preparations are extremely stable, and even through 4-year storage at -20 degrees C, the electrophorogram and transformation efficiency remain as high as before. The factors affecting the stability of various DNA samples are discussed.