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1.
Artículo en Zh | MEDLINE | ID: mdl-36229212

RESUMEN

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.


Asunto(s)
Accesibilidad a los Servicios de Salud , Salud Laboral , Adulto , Derechos Humanos , Humanos , Prevalencia , Encuestas y Cuestionarios
2.
Artículo en Zh | MEDLINE | ID: mdl-35915939

RESUMEN

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.


Asunto(s)
Golpe de Calor , Salud Laboral , Traumatismos Ocupacionales , Accidentes de Trabajo , Ciudades , Golpe de Calor/epidemiología , Humanos , Traumatismos Ocupacionales/epidemiología , Saneamiento
3.
Zhonghua Wai Ke Za Zhi ; 55(7): 491-495, 2017 Jul 01.
Artículo en Zh | MEDLINE | ID: mdl-28655075

RESUMEN

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.


Asunto(s)
Neoplasias Colorrectales/patología , Hepatectomía , Neoplasias Hepáticas/cirugía , Humanos , Neoplasias Hepáticas/secundario , Estudios Prospectivos
4.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 34(12): 931-934, 2016 Dec 20.
Artículo en Zh | MEDLINE | ID: mdl-28241684

RESUMEN

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.


Asunto(s)
Síndrome por Vibración de la Mano y el Brazo , Traumatismos de los Nervios Periféricos/etiología , Vibración/efectos adversos , Adulto , Síndrome del Túnel Carpiano , Electromiografía , Mano , Humanos , Masculino , Nervio Mediano , Persona de Mediana Edad , Conducción Nerviosa , Enfermedades Profesionales , Ocupaciones , Nervios Periféricos , Modalidades de Fisioterapia , Muñeca , Adulto Joven
5.
J Small Anim Pract ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38957893

RESUMEN

OBJECTIVES: Adiponectin plays an important role in carbohydrate and lipid metabolism. However, the evidence regarding the association between adiponectin and diabetes mellitus in obese dogs is sparse. The aim of this study is to investigate the associations of adiponectin with the risk of diabetes mellitus in obese dogs on the basis of a prospective cohort study. MATERIALS AND METHODS: Serum adiponectin levels in obese dogs recruited from three small animal hospitals between 2015 and 2018 were measured by ELISA. Electronic health records were used to record the incidence of diabetes mellitus during follow-up for 3 years. RESULTS: A total of 862 dogs were included. Amongst the 862 dogs, 51 developed diabetes. Adiponectin levels were associated with diabetes mellitus after adjusting for sex, age, breed, exercise, body condition score, fasting plasma glucose, serum triglyceride and total cholesterol. When adjusting for sex, age, breed, exercise, body condition score, fasting plasma glucose, serum triglyceride and total cholesterol, the adjusted hazard ratios were 7.83 (95% confidence interval: 2.67 to 30.13) in the lowest adiponectin group and 1.96 (95% CI: 1.10 to 8.55) in the medium adiponectin group relative to that in the highest adiponectin group. The area under a curve of adiponectin's Receiver operating characteristic curve was 0.81 (95% CI: 0.76 to 0.86). CLINICAL SIGNIFICANCE: Low adiponectin is associated with diabetes mellitus and has a high risk of incident diabetes mellitus, implying the potential of adiponectin as a predictive biomarker of diabetes mellitus in obese dogs.

7.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(6): 584-588, 2020 Jun 25.
Artículo en Zh | MEDLINE | ID: mdl-32521979

RESUMEN

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.


Asunto(s)
Neoplasias Colorrectales/cirugía , Hepatectomía/métodos , Neoplasias Hepáticas/cirugía , Neoplasias Primarias Múltiples/cirugía , Anciano , Neoplasias Colorrectales/patología , Estudios de Factibilidad , Femenino , Humanos , Laparoscopía , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento
8.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(4): 364-369, 2020 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-32306604

RESUMEN

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.


Asunto(s)
Fuga Anastomótica/etiología , Proctectomía/efectos adversos , Neoplasias del Recto/cirugía , Procedimientos Quirúrgicos Robotizados/efectos adversos , Anciano , Anastomosis Quirúrgica/efectos adversos , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo
9.
Acta Physiol (Oxf) ; 223(3): e13038, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29352512

RESUMEN

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.


Asunto(s)
Analgésicos/farmacología , Hipotermia/inducido químicamente , Canales Catiónicos TRPV/antagonistas & inhibidores , Analgésicos/síntesis química , Animales , Capsaicina , Desarrollo de Medicamentos , Hipotermia/metabolismo , Masculino , Ratones , Protones , Ratas Sprague-Dawley , Ratas Wistar , Canales Catiónicos TRPV/metabolismo , Termogénesis/efectos de los fármacos , Vasodilatación/efectos de los fármacos
10.
Oncogene ; 5(6): 873-7, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2141686

RESUMEN

Human promyelocytic leukemia HL-60 cells were induced to differentiate into macrophages by PMA (phorbol 12-myristate-13-acetate), 1-alpha-25-(OH)2D3(1-alpha-25-dihydroxyvitamin D3, hrGM-CSF (human recombinant granulocyte-macrophage colony-stimulating factor) and into granulocytes by DMSO (dimethylsulfoxide). We found that the differentiation of HL-60 cells into macrophages was accompanied by transcription of the c-fms oncogene, which was assessed by a modified PCR (polymerase-chain reaction) method. After treatment with a c-fms anti-sense oligomer, the PMA and hrGM-CSF induced macrophage differentiation of HL-60 cells was significantly inhibited, whereas either 1-alpha-25-(OH)2D3 induced macrophage or DMSO and hrGM-CSF induced granulocytic differentiation was not inhibited. Furthermore, we treated the HL-60 cells with M-CSF (macrophage-colony stimulating factor or CSF-1) anti-sense N degrees 2 (see Figure 1) in the presence of PMA, hrGM-CSF, 1-alpha-25-(OH)2D3 and DMSO. The results showed that this treatment leads to a significant inhibition of PMA and hrGM-CSF-induced macrophage differentiation, but has no influence on the 1-alpha-25-(OH)2D3-induced macrophage differentiation and DMSO-induced granulocytic differentiation. It was further demonstrated that the M-CSF (or CSF-1) and c-fms antisense oligomers acted synergistically on inhibition of macrophage formation induced by PMA and hrGM-CSF, but had no inhibitory effect on the macrophage formation induced by 1-alpha-25-(OH)2D3. Thus we concluded firstly, that HL-60 cells differentiate into macrophages along two different pathways: one is involved in the action of the c-fms oncogene and the other is not. Secondly, an autocrine circuit of M-CSF (or CSF-1) action may exist in the macrophage formation induced by PMA and hrGM-CSF.


Asunto(s)
Transformación Celular Neoplásica/efectos de los fármacos , Leucemia Promielocítica Aguda/patología , Proteínas Proto-Oncogénicas/fisiología , Secuencia de Bases , Calcitriol/farmacología , Transformación Celular Neoplásica/patología , Factores Estimulantes de Colonias/farmacología , Dimetilsulfóxido/farmacología , Expresión Génica/efectos de los fármacos , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Sustancias de Crecimiento/farmacología , Humanos , Factor Estimulante de Colonias de Macrófagos , Macrófagos/efectos de los fármacos , Macrófagos/fisiología , Datos de Secuencia Molecular , Oligonucleótidos/farmacología , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas/genética , ARN Mensajero/genética , Receptor de Factor Estimulante de Colonias de Macrófagos , Acetato de Tetradecanoilforbol/farmacología , Transcripción Genética/efectos de los fármacos , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/patología
11.
J Biochem ; 111(4): 537-45, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1618743

RESUMEN

Two arrowhead proteinase inhibitors (inhibitors A and B) were characterized and their primary structures were determined. Both inhibitors A and B are double-headed and multifunctional protease inhibitors. Inhibitor A inhibits an equimolar amount of trypsin and chymotrypsin simultaneously and weakly inhibits kallikrein. Inhibitor B inhibits two molecules of trypsin simultaneously and inhibits kallikrein more strongly than does inhibitor A. The amino acid sequences of inhibitors A and B were determined by sequencing the reduced and S-carboxamidomethylated proteins and their peptides produced by cyanogen bromide or proteolytic lysylendopeptidase or Staphylococcus aureus V8 protease cleavage. Inhibitors A and B consist of 150 amino acid residues with three disulfide bonds (Cys 43-Cys 89, Cys 110-Cys 119, and Cys 112-Cys 115) and share 90% sequence identity, with 13 different residues. Since the primary structures are totally different from those of all other serine protease inhibitors so far known, these inhibitors might be classified into a new protease inhibitor family.


Asunto(s)
Disulfuros/química , Proteínas de Plantas/química , Inhibidores de Proteasas/química , Secuencia de Aminoácidos , Datos de Secuencia Molecular , Inhibidores de Proteasas/aislamiento & purificación , Inhibidores de Proteasas/farmacología , Serina Endopeptidasas/metabolismo
12.
DNA Cell Biol ; 13(1): 83-6, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8286043

RESUMEN

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.


Asunto(s)
ADN Bacteriano/aislamiento & purificación , Plásmidos/aislamiento & purificación , 1-Propanol , Ácido Edético , Calor , Concentración de Iones de Hidrógeno
13.
Artículo en Inglés | MEDLINE | ID: mdl-9252874

RESUMEN

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.


Asunto(s)
Aspirina/efectos adversos , Aspirina/inmunología , Hipersensibilidad a las Drogas/inmunología , Inmunoglobulina E/sangre , Pirazolonas , Adolescente , Adulto , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/inmunología , Niño , Reacciones Cruzadas , Femenino , Humanos , Inmunoglobulina E/química , Masculino , Persona de Mediana Edad , Pirazoles/efectos adversos , Pirazoles/inmunología , Salicilatos/efectos adversos , Salicilatos/inmunología
14.
Sci China B ; 34(7): 832-9, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1878144

RESUMEN

Affinity chromatography was used to separate two components A and B of the crystalline arrowhead proteinase inhibitor. Both A and B are double-headed and multifunctional proteinase inhibitors. Inhibitor A is capable of inhibiting equimolarly trypsin and chymotrypsin simultaneously, and has a weak inhibitory activity toward kallikrein; whereas inhibitor B can inhibit two molecules of trypsin simultaneously, and shows rather higher inhibitory activity toward kallikrein than inhibitor A, but its inhibitory activity toward chymotrypsin is much weaker than that of inhibitor A. The results of chemical modification and the competitive binding of trypsin and chymotrypsin with inhibitor A showed that the two reactive sites of both inhibitors A and B are Lys and Arg residues. Among them the Lys reactive site is specific for inhibiting mainly trypsin, whereas the active domain composed of the Arg reactive site appears to be multifunctional and capable of inhibiting many different Ser proteinases. Based on the structural characteristics of inhibitors A and B, it was predicated that the two reactive sites should be located in the positions Lys-Ser (44-45) and Arg-Tyr-Lys (76-78), respectively. In inhibitor A, there exists another hydrophobic residue involved in inhibiting chymotrypsin. This residue might be situated in the reactive region composed of the Arg reactive site.


Asunto(s)
Inhibidores de Serina Proteinasa/química , Quimotripsina/metabolismo , Calicreínas/metabolismo , Plantas/análisis , Inhibidores de Serina Proteinasa/farmacología , Tripsina/metabolismo
15.
Sci China B ; 36(12): 1483-9, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8129836

RESUMEN

The B-chain of urokinase (UK) was covalently linked by disulfide bond to the Fab fragment of an anti-human activated platelet monoclonal antibody (SZ-51). The UK-SZ-51 conjugate retained the original binding specificity of its parent antibody, and produced about a 5-fold enhancement in clot lysis in plasma over that of the urokinase in vitro. Whereas UK significantly decreased the concentration of fibrinogen in plasma clot assay supernatants, UK-SZ-51 did not.


Asunto(s)
Fibrinólisis/efectos de los fármacos , Inmunotoxinas/farmacología , Activador de Plasminógeno de Tipo Uroquinasa/farmacología , Anticuerpos Monoclonales , Antígenos CD , Moléculas de Adhesión Celular , Fibrinolíticos/farmacología , Humanos , Fragmentos Fab de Inmunoglobulinas/farmacología
16.
Sci China B ; 37(6): 667-76, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7917003

RESUMEN

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.


Asunto(s)
Kringles/genética , Activador de Tejido Plasminógeno/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN/biosíntesis , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Humanos , Datos de Secuencia Molecular , Fragmentos de Péptidos/biosíntesis , Activador de Tejido Plasminógeno/química , Activador de Tejido Plasminógeno/metabolismo
17.
Sci China B ; 35(2): 176-82, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1581002

RESUMEN

The Kringle-1 structure of plasminogen (PGK-1), the Kringle-2 structure of tissue plasminogen activator (PAK-2) and the Kringle structure of prourokinase (UKK) has been modeled on the basis of the three-dimensional structure of Kringle-1 of prothrombin (PTK-1) at 2.8 A resolution. The predicted three-dimensional structure of these Kringles shows that the binding site of PGK-1 is characterized by an apparent dipolar site, the polar parts of which are separated by a hydrophobic region. PAK-2 possesses the anionic center but has not a cationic binding center which might be provided by a guanidinium group from Arg-69 located adjacent to the Arg-71 position. UKK possesses neither the anionic binding center nor the cationic center which are probably the main reason for the poor fibrin specificity of urokinase.


Asunto(s)
Activador de Plasminógeno de Tipo Uroquinasa/genética , Secuencia de Aminoácidos , Conformación Molecular , Datos de Secuencia Molecular , Activador de Tejido Plasminógeno/genética
18.
Sci China B ; 35(8): 966-73, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1338753

RESUMEN

In view of the similarity of the charge distribution between fibrin A alpha 148-161 and A chain 149-157 of urokinase, the latter might compete with fibrin A alpha 148-161 when single chain pro-urokinase is converted to double chain urokinase. To test this, the stretch of urokinase A chain 135-157 was separated from the low molecular weight urokinase, a competitive binding between this stretch and fibrin to tPA kringle-2 was shown by radio-binding assay. The inhibition of the stretch on the fibrin stimulated activation of plasminogen was demonstrated in the caseinolytic system. The synthesized novapeptide urokinase A chain 149-157 (R-peptide) showed a significant inhibition on the activation of plasminogen in the presence of fibrin. By contrasting finely with R-peptide, a synthesized novapeptide in which Arg154 and Arg156 were replaced by Asp (D-peptide) did not show any inhibition effect on the fibrin stimulated activation of plasminogen by tPA. These results suggest that the positively charged residues in the stretch 149-157 of urokinase are crucial for the inhibition of fibrin binding with the kringle domain of urokinase.


Asunto(s)
Fibrina/farmacología , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Activador de Tejido Plasminógeno/farmacología , Activador de Plasminógeno de Tipo Uroquinasa/farmacología , Secuencia de Aminoácidos , Péptido C/metabolismo , Precursores Enzimáticos/metabolismo , Fibrinolisina/metabolismo , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Plasminógeno/metabolismo , Proteínas Recombinantes/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/química , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo
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