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1.
Hong Kong Med J ; 2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36171145

RESUMEN

INTRODUCTION: It is clinically challenging to differentiate the pathophysiological types of shock in emergency situations. Here, we evaluated the ability of a novel bedside ultrasound protocol (Tamponade/tension pneumothorax, Heart, Inferior vena cava, Respiratory system, Deep venous thrombosis/aorta dissection [THIRD]) to predict types of shock in the emergency department. METHODS: An emergency physician performed the THIRD protocol on all patients with shock who were admitted to the emergency department. All patients were closely followed to determine their final clinical diagnoses. The kappa index, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the initial diagnostic impression provided by the THIRD protocol, compared with each patient's final diagnosis. RESULTS: In total, 112 patients were enrolled in this study. The kappa index between initial impression and final diagnosis was 0.81 (95% confidence interval=0.73-0.89; P<0.001). For hypovolaemic, cardiogenic, distributive, and obstructive types of shock, the sensitivities of the THIRD protocol were 100%, 100%, 93%, and 100%, respectively; the sensitivity for a 'mixed' shock aetiology was 86%. The negative predictive value of the THIRD protocol for all five types of shock was ≥96%. CONCLUSION: Initial diagnostic judgements determined using the THIRD protocol showed favourable agreement with the final diagnosis in patients who presented with undifferentiated shock. The THIRD protocol has great potential for use as a bedside approach that can guide the rapid management of undifferentiated shock in emergency settings, particularly for patients with obstructive, hypovolaemic, or cardiogenic shock.

4.
Zhonghua Yi Xue Za Zhi ; 98(38): 3096-3101, 2018 Oct 16.
Artículo en Chino | MEDLINE | ID: mdl-30392271

RESUMEN

Objective: To analysis the treatment effect of the ulnar osteotomy and ring-shaped ligament reconstruction for the treatment of old Monteggia fracture in children by using Meta analyze, and the difference of clinical curative effect was compared in order to provide the basis for the selection of clinical treatment options for old Monteggia fractures in children. Methods: We searched databases such as CNKI, Wanfang database, Medline, PubMed, Embase and Science through computer, at the same time, the references of relevant documents were retrieved manually, and the data processing was carried out by the RevMan5.3 statistical software provided by the Cochrane cooperation network by incorporating the exclusion criteria. The results were obtained and analyzed. Results: A total of 17 standard literature, 438 cases, 224 cases of ulnar osteotomy, 214 cases with ring ligament repair and reconstruction were obtained. The operation scheme, which was mainly based on the lengthening of ulna osteotomy, was superior to the reconstruction of ring ligament reconstruction. The complications and second operation rates of the former was less than that of the latter. Conclusion: The surgical methods for the reconstruction of the ulna osteotomy and the ring-shaped ligament have advantages and disadvantages. The choice of the operative plan for the old Monteggia fracture should be based on the following factors: the time of the old Monteggia fracture formation, the degree of the ulnar and radial deformity and the familiarity of the operative method.


Asunto(s)
Articulación del Codo , Fractura de Monteggia , Niño , Humanos , Osteotomía , Radio (Anatomía) , Cúbito
5.
Hum Exp Toxicol ; 37(6): 626-635, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28741371

RESUMEN

Acute lung injury (ALI) is a major outcome of exposure to high levels of hydrogen sulfide (H2S). Dexamethasone (DXM) has been used to treat ALI. However, the mechanisms involved in H2S-induced ALI and the protective mechanisms of DXM in treating ALI are still nebulous. To explore the mechanisms involved, we evaluated the role of claudin-5 in the protective effect of DXM against H2S-induced ALI. Sprague-Dawley rats were exposed to H2S to establish the ALI model. In parallel with the animal model, a cell model was also established by incubating human umbilical vein endothelial cells (HUVECs) with NaHS. Lung hematoxylin-eosin staining, electron microscope assay, and wet/dry ratio were used to identify whether the ALI was successfully induced by H2S, and changes in claudin-5 expression were detected in both rats and HUVECs. Our results revealed that claudin-5 was markedly decreased after H2S exposure and that DXM significantly attenuated the H2S-induced downregulation of claudin-5 in both rats and HUVECs. In the animal experiment, p-Akt and p-FoxO1 presented a similar tendency as claudin-5, but their levels decreased 6 h prior to the levels of claudin-5. In a further investigation, the DXM-induced protective effect on ALI and rescue effect on downregulation of claudin-5 were both blocked by LY294002. The current study demonstrated that claudin-5 was involved in the development of H2S-induced ALI and that DXM exerted protective effects through increasing claudin-5 expression by activating the phosphatidylinositol 3-kinase pathway. Therefore, claudin-5 might represent a novel pharmacological target for treating ALI induced by H2S and other hazardous gases.


Asunto(s)
Lesión Pulmonar Aguda/metabolismo , Antiinflamatorios/farmacología , Claudina-5/metabolismo , Dexametasona/farmacología , Sulfuro de Hidrógeno/toxicidad , Fosfatidilinositol 3-Quinasas/metabolismo , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/patología , Animales , Antiinflamatorios/uso terapéutico , Células Cultivadas , Dexametasona/uso terapéutico , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , Pulmón/ultraestructura , Masculino , Microscopía Electrónica de Transmisión , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 38(12): 1703-1707, 2017 Dec 10.
Artículo en Chino | MEDLINE | ID: mdl-29294591

RESUMEN

Meta-analysis used for genetic association studies became popular among researchers, with the amount of published papers increased rapidly. In this paper, we will focus on the introduction on the selection of genetic models. Traditionally, methods used for Meta-analysis on genetic association studies was to calculate the statistics based on available genetic models which not only increasing the probability of false-positives but also making the interpretation of results more difficult. Hence, a critical step in the Meta-analysis of genetic association studies was to choose the appropriate inheritance model. The aim of this paper was to introduce the theory of Bayesian analysis regarding the genetic model-free approach, in performing the Meta-analysis for studies related to genetic associations.


Asunto(s)
Teorema de Bayes , Estudios de Asociación Genética , Modelos Genéticos , Predisposición Genética a la Enfermedad , Humanos , Polimorfismo de Nucleótido Simple , Probabilidad
7.
Dis Esophagus ; 29(7): 864-871, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26123848

RESUMEN

Megaesophagus is a disease where peristalsis fails to occur properly and esophagus is enlarged. The etiology and mechanism of megaesophagus are not well understood. In this study, we reported that junctional adhesion molecule C (JAM-C) knockout mice on a C57/B6 background developed progressive megaesophagus from embryonic day (E) 15.5 onward with complete penetrance. JAM-C knockout mice exhibited a significant reduction in the number of nerve fibers/ganglia in the wall of the esophagus. However, histological analysis revealed that the esophageal wall thickness and structure of JAM-C knockout mice at embryonic stages and young adult were comparable to that of control littermates. Thus, megaesophagus observed in JAM-C knockout mice could be attributed, at least in part, to impaired esophageal innervations. Our data suggest JAM-C as a potential candidate gene for human megaesophagus, and JAM-C knockout mice might serve as a model for the study of human megaesophagus.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Acalasia del Esófago/genética , Esófago/inervación , Inmunoglobulinas/metabolismo , Animales , Acalasia del Esófago/embriología , Acalasia del Esófago/patología , Esófago/embriología , Esófago/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
8.
Pharmazie ; 70(1): 33-7, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25975096

RESUMEN

Mammalian cells have been widely used for the in vitro evaluation of the functional effect of allelic variants of cytochrome P450 (CYP). The aim of this study was to determine the most suitable mammalian cell line for the in vitro drug metabolism analysis of CYP variants. Three reported cell lines (COS-7, HepG2, 293T) and one fast-growing variant of the 293 cell line 293FT were transfected with vectors expressing green fluorescent protein or typical variants of CYP2C9, CYP2C19 or CYP2D6 to investigate the protein expression levels and the catalytic activity of expressed CYP allelic variants. The transfected 293FT cells had the highest protein expression level and exhibited the highest enzymatic activity, while HepG2 cells showed the lowest activity among the four tested cell lines. Simultaneously, 293FT cells still maintained the similar relative enzymatic ratio among three typical CYP2C9 variants to that of the commonly used COS-7 cells. In addition, 293FT cells could also be used for the in vitro functional evaluation of two other typical P450 proteins, CYP2C19 and CYP2D6. Therefore, the 293FT cell line is more suitable for the in vitro enzymatic activity analysis of typical P450 proteins than any other reported mammalian cell lines.


Asunto(s)
Línea Celular , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/biosíntesis , Sistema Enzimático del Citocromo P-450/genética , Expresión Génica/efectos de los fármacos , Células HEK293 , Humanos , Preparaciones Farmacéuticas/metabolismo , Plásmidos/genética , Biosíntesis de Proteínas/efectos de los fármacos , Transfección
9.
Cell Death Differ ; 22(10): 1630-40, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25698448

RESUMEN

Primary human fibroblasts undergoing oncogene-induced or replicative senescence are known to form senescence-associated heterochromatin foci (SAHF), which can stabilize the state of senescence. The retinoblastoma (RB) protein has an important role in SAHF; cells that lack active RB pathway fail to form SAHF. It has been known that the posttranslational modifications of RB, for example, phosphorylation, regulate its function. To date, whether methylation of RB impacts on the SAHF formation is unknown. Here we report that JMJD3, a histone demethylase catalyzing the tri-methylation of H3K27 (H3K27me3), can demethylate the non-histone protein RB at the lysine810 residue (K810), which is a target of the methyltransferase Set7/9. We detected a significant upregulation of JMJD3 during cellular senescence and SAHF formation in WI38 cells induced by H-RasV(12), and we found that ectopic expression of JMJD3 promoted cellular senescence and SAHF formation in WI38 cells. Furthermore, during the process of SAHF assembly, JMJD3 was transported to the cytoplasm and interacted with RB through its demethylase domain JmjC. Significantly, our data demonstrated that the JMJD3-mediated demethylation of RB at K810 impeded the interaction of RB with the protein kinase CDK4 and resulted in reduced level of phosphorylation of RB at Serine807/811 (S807/811), implicating an important role of the interplay between the demethylation and phosphorylation of RB in SAHF assembly. This study highlights the role of JMJD3 as a novel inducer of SAHF formation through demethylating RB and provides new insights into the mechanisms of cellular senescence and SAHF assembly.


Asunto(s)
Senescencia Celular , Fibroblastos/metabolismo , Heterocromatina/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteína de Retinoblastoma/metabolismo , Línea Celular , Fibroblastos/fisiología , Humanos , Metilación , Fosforilación
10.
Rev Sci Instrum ; 85(8): 083504, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25173266

RESUMEN

In order to mitigate the negative effects of the plasma disruption a massive gas injection (MGI) valve is designed for the joint Texas experimental tokamak. The MGI valve is based on the eddy-current repulsion mechanism. It has a fueling volume of 30 ml. The piston of the MGI valve is made by non-ferromagnetic material, so it can be installed close to the vacuum vessel which has a strong toroidal magnetic field. A diode is use to prevent current oscillation in the discharge circuit. The drive coil of the valve is installed outside the gas chamber. The opening characteristics and the gas flow of the MGI valve have been tested by a 60 l vacuum chamber. Owing to the large electromagnetic force the reaction time of the valve is shorter than 0.3 ms. Duration for the opening of the MGI valve is in the order of 10 ms.

11.
Pharmacogenomics J ; 14(1): 85-92, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23400009

RESUMEN

Genetic polymorphisms of CYP2C9 significantly influence the pharmacokinetics and pharmacodynamics of some drugs, which might result in adverse drug effects and therapeutic failure. Several studies have been performed on CYP2C9 genetic polymorphisms in Han Chinese populations. However, these studies only focused on two commonly investigated alleles, *2 and *3, in relatively small sample sizes. To scale up the gene-scanning region and determine relatively precise data on the genetic distribution pattern in Chinese populations, unrelated healthy Han Chinese volunteers from Zhejiang Province (n=1127) and Hebei (n=1000) Province were recruited as subjects for the direct sequencing of all exons of CYP2C9. As a result, 14 previously reported alleles were detected in this work, and 8 of these alleles (*14, *16, *19, *23, *27, *29, *33 and *34) were described for the first time in Chinese populations. In addition, 37 novel mutations were also detected, of which 22 variants were non-synonymous, and 21 new alleles, *36-*56, were designated by the Human CYP Allele Nomenclature Committee. In vitro functional analysis of these 22 novel CYP2C9 variants revealed that 17 mutations had a significant influence on the protein's catalytic activity. Our study provides the most accurate data on CYP2C9 polymorphisms in Han Chinese populations and detects the largest number of novel allelic variants existing to date. These new alleles will greatly enrich the current knowledge of naturally occurring CYP2C9 variants in Chinese populations.


Asunto(s)
Hidrocarburo de Aril Hidroxilasas/genética , Pueblo Asiatico/genética , Bases de Datos Genéticas , Frecuencia de los Genes , Genética de Población , Polimorfismo Genético , Alelos , Animales , Hidrocarburo de Aril Hidroxilasas/metabolismo , Células COS , China , Chlorocebus aethiops , Citocromo P-450 CYP2C9 , Exones , Genotipo , Humanos , Preparaciones Farmacéuticas/metabolismo
12.
Prikl Biokhim Mikrobiol ; 49(2): 181-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23795478

RESUMEN

The search for the effective and safe a-glucosidase and alpha-amylase inhibitors from Actinomycetaceae being antidiabetic agents is actual problem. Twenty one Streptomyces spp. of soil samples collected from different places of China were screened for the ability to produce this kind of inhibitory activities. Fermentation broth of isolated strains had absorbance between 350-190 nm. The Streptomyces strains PW003, ZG636, and ZG731 were characterized by special absorption at 280, 275, and 400 nm, respectively. Ten of the collected actinomycete strains had the ability to inhibit alpha-glucosidase or/and alpha-amylase and the fermentation broth of the same strain had inhibitory activity varied greatly depending on the enzyme source. In the process to screen the leading compounds used as antidiabetic agents, human alpha-glucosidase and alpha-amylase were revealed as the best used in trail compared with the same enzymes from other sources. Active alpha-glucosidase inhibitor was isolated from Streptomyces strain PW638 fermentation broth and identified as acarviostatin 103 by MS and N MR spectrometry. Its IC50 value was 1.25 and 12.23 microg/mL against human intestinal N-terminal maltase-glucoamylase and human pancreatic alpha-amylase, respectively.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores de Glicósido Hidrolasas , Hipoglucemiantes/química , Oligosacáridos/química , alfa-Amilasas Pancreáticas/antagonistas & inhibidores , Microbiología del Suelo , Streptomyces/química , Animales , China , Pruebas de Enzimas , Inhibidores Enzimáticos/aislamiento & purificación , Fermentación , Humanos , Hipoglucemiantes/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Microscopía Electrónica de Rastreo , Oligosacáridos/aislamiento & purificación , Ratas , Streptomyces/metabolismo , Streptomyces/ultraestructura
13.
Lett Appl Microbiol ; 55(2): 162-9, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22691180

RESUMEN

AIMS: The aims of this study are to obtain the draft genome sequence of Streptomyces coelicoflavus ZG0656, which produces novel acarviostatin family α-amylase inhibitors, and then to reveal the putative acarviostatin-related gene cluster and the biosynthetic pathway. METHODS AND RESULTS: The draft genome sequence of S. coelicoflavus ZG0656 was generated using a shotgun approach employing a combination of 454 and Solexa sequencing technologies. Genome analysis revealed a putative gene cluster for acarviostatin biosynthesis, termed sct-cluster. The cluster contains 13 acarviostatin synthetic genes, six transporter genes, four starch degrading or transglycosylation enzyme genes and two regulator genes. On the basis of bioinformatic analysis, we proposed a putative biosynthetic pathway of acarviostatins. The intracellular steps produce a structural core, acarviostatin I00-7-P, and the extracellular assemblies lead to diverse acarviostatin end products. CONCLUSIONS: The draft genome sequence of S. coelicoflavus ZG0656 revealed the putative biosynthetic gene cluster of acarviostatins and a putative pathway of acarviostatin production. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, S. coelicoflavus ZG0656 is the first strain in this species for which a genome sequence has been reported. The analysis of sct-cluster provided important insights into the biosynthesis of acarviostatins. This work will be a platform for producing novel variants and yield improvement.


Asunto(s)
Genoma Bacteriano , Análisis de Secuencia de ADN , Streptomyces/genética , Streptomyces/metabolismo , alfa-Amilasas/antagonistas & inhibidores , Vías Biosintéticas , Familia de Multigenes , Streptomyces/química , Streptomyces/clasificación
14.
Phys Rev Lett ; 106(11): 112501, 2011 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-21469858

RESUMEN

Mass excesses of short-lived A=2Z-1 nuclei (63)Ge, (65)As, (67)Se, and (71)Kr have been directly measured to be -46,921(37), -46,937(85), -46,580(67), and -46,320(141) keV, respectively. The deduced proton separation energy of -90(85) keV for (65)As shows that this nucleus is only slightly proton unbound. X-ray burst model calculations with the new mass excess of (65)As suggest that the majority of the reaction flow passes through (64)Ge via proton capture, indicating that (64)Ge is not a significant rp-process waiting point.

15.
J Appl Microbiol ; 106(2): 525-33, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19054225

RESUMEN

AIMS: To clarify the taxonomic status of strain ZG0656 and analyse the effects of its acarviostatin products on blood glucose levels in mammalian systems. METHODS AND RESULTS: Our program to screen for new alpha-amylase inhibitors led to the isolation of strain ZG0656. The polyphasic taxonomic study revealed that strain ZG0656 represents a novel variation of Streptomyces coelicoflavus, for which we propose the name S. coelicoflavus var. nankaiensis. Four chemically distinct alpha-amylase inhibitors, acarviostatins I03, II03, III03 and IV03, were isolated from strain ZG0656. Acarviostatins III03 and IV03 are both novel oligomers. All four acarviostatins are mixed noncompetitive porcine pancreas alpha-amylase inhibitors. Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. Moreover, in the in vitro and in vivo experiments, acarviostatins III03 showed significant inhibition of starch hydrolysis and glucose transfer to blood. CONCLUSIONS: Strain ZG0656 is a novel variation of S. coelicoflavus, whose products are novel effective alpha-amylase inhibitors. Among the products, acarviostatins III03 could significantly depress blood glucose levels in mammalian systems and be developed towards a possible therapeutic agent for diabetes. SIGNIFICANCE AND IMPACT OF THE STUDY: Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. The oligomer will benefit the research on the relationship between alpha-amylase and various inhibitors and will offer more choices in diabetes treatments.


Asunto(s)
Glucemia/análisis , Inhibidores Enzimáticos/metabolismo , Streptomyces/clasificación , alfa-Amilasas/antagonistas & inhibidores , Animales , Femenino , Fermentación , Masculino , Ratones , Estructura Molecular , Ratas , Ratas Wistar , Almidón/metabolismo , Streptomyces/crecimiento & desarrollo , Streptomyces/metabolismo , Porcinos
16.
Parasitol Res ; 102(6): 1201-6, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18309521

RESUMEN

Cystic echinococcosis (CE) is highly endemic in the Chinese province of Qinghai, located on the Tibetan Plateau. The Echinococcus granulosus sheep strain has already been reported in this focus. To improve our understanding of the role the parasite plays in the high prevalence observed in humans, we assessed the genetic polymorphism of 55 E. granulosus samples (37 from humans) using three discriminative mitochondrial markers: coxI, nadI and atp6. We obtained a total of 13 distinct genotypes which were all related to the common sheep G1 strain. Six of these genotypes have already been reported in China and other foci around the world. The remaining seven genotypes were new variants of the strain. The parasite population which was studied in the present work did not differ substantially from those observed in other foci of CE. Environmental conditions and human behaviour could explain the high incidence of the parasitic disease, particularly in the Tibetan population in the south of Qinghai, most of whom are livestock farmers.


Asunto(s)
Equinococosis/parasitología , Echinococcus granulosus/clasificación , Echinococcus granulosus/genética , Polimorfismo Genético , Adolescente , Adulto , Anciano , Animales , China , Equinococosis/epidemiología , Echinococcus granulosus/aislamiento & purificación , Complejo IV de Transporte de Electrones/genética , Enfermedades Endémicas , Femenino , Genes Mitocondriales , Genotipo , Proteínas del Helminto/genética , Humanos , Masculino , Persona de Mediana Edad , Proteínas Mitocondriales/genética , ATPasas de Translocación de Protón Mitocondriales/genética , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Enfermedades de las Ovejas/parasitología , Taiwán/epidemiología , Zoonosis/parasitología
17.
J Chem Phys ; 121(22): 11301-8, 2004 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-15634086

RESUMEN

Catalytic CO oxidation on the RuO(2)(110) surface was studied at 300 K by scanning tunneling microscopy (STM), high-resolution electron-energy-loss spectroscopy (HREELS), and thermal desorption spectroscopy (TDS). Upon repeatedly exposing the surface to several 10 L of CO and O(2) at 300 K, STM shows that unreactive features accumulate with each CO and O(2) titration run. HREELS and TDS show formation of increasing amounts of H(2)O, retarded formation of O-cus atoms and incomplete removal of CO-bridge molecules during O(2) dosing, and a changing ratio of single- and double-bonded CO-bridge molecules. It is concluded that H(2)O (presumably from the residual gas) is accumulating at the Ru-cus sites thus blocking them, so that the dissociative adsorption of oxygen is prevented and the CO oxidation reaction is suppressed. Some 10% CO- bridge remains on the surface even during oxygen exposure. Consistent with this interpretation, deactivation of the surface is suppressed at 350 K, at the onset of H(2)O desorption.

19.
Microbiol Immunol ; 38(9): 703-11, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7854211

RESUMEN

Recombinant murine tumor necrosis factor-alpha (TNF-alpha) inhibited intracellular growth of Rickettsia tsutsugamushi, Karp strain, in the mouse embryo cell line C3H/10T1/2 clone 8 at doses of 100 to 10 U/ml. The growth inhibitory effect of TNF-alpha was also evident when peritoneal exudate macrophages or bone marrow-derived macrophages were used as the host cell for rickettsial growth. Interferon-gamma (IFN-gamma), at doses up to 1,000 U/ml, did not affect the growth of this strain of rickettsiae in the mouse embryo cell line but, as expected, profoundly inhibited rickettsial growth in peritoneal exudate macrophages and bone marrow-derived macrophages. The effect of TNF-alpha on rickettsial growth in the mouse embryo cell line was not reproducibly enhanced by IFN-gamma. Treatment of the cell line with TNF-alpha delayed rickettsial cytopathic effects, but the rickettsiae ultimately grew to high numbers in the cells and caused cell death. These findings show that, at least in our system, R. tsutsugamushi is resistant to IFN-gamma-mediated antirickettsial effects in cells other than macrophages. The results of this study support the suggestion that TNF-alpha may inhibit rickettsial growth in cells other than macrophages.


Asunto(s)
Macrófagos Peritoneales/microbiología , Orientia tsutsugamushi/crecimiento & desarrollo , Factor de Necrosis Tumoral alfa/farmacología , Animales , Muerte Celular , Línea Celular , Células Cultivadas , Interferón gamma/farmacología , Ratones , Ratones Endogámicos C3H/embriología , Ratones Endogámicos C57BL , Orientia tsutsugamushi/efectos de los fármacos , Proteínas Recombinantes/farmacología , Tifus por Ácaros/prevención & control , Factor de Necrosis Tumoral alfa/fisiología
20.
Microbiol Immunol ; 38(9): 713-9, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7854212

RESUMEN

The present study was undertaken to investigate the ability of members of two different groups of Rickettsia to stimulate macrophages or immune lymphocytes to produce TNF. It was found that R. conorii, a spotted fever group rickettsia, readily induced murine peritoneal macrophages or the macrophage-like cell line P388D1 to produce relatively high levels of TNF. The interaction of macrophages with viable organisms or heat-killed organisms resulted in TNF production. In contrast, viable or killed R. tsutsugamushi did not stimulate the production of detectable TNF even though viable organisms grew to high numbers in both cell types. It was found that the appropriate immune spleen cells stimulated with heat-killed R. tsutsugamushi or R. conorii produced TNF, and TNF activity was found in the sera of immune mice after injection with rickettsial antigen. Infection of naive mice with viable R. tsutsugamushi resulted in high TNF levels in ascites, but TNF was not found in ascites obtained from infected athymic (nu/nu) mice. These data support the suggestion that spotted fever group rickettsiae, such as R. conorii, possess components perhaps on the surface that interact with macrophages to induce TNF production and this component is lacking in R. tsutsugamushi. Antigens of R. tsutsugamushi and R. conorii will stimulate immune cells to produce TNF activity. These data are compatible with the suggestion that the TH-1 subset of T cells is predominant in immunity to R. tsutsugamushi.


Asunto(s)
Linfocitos/metabolismo , Macrófagos Peritoneales/metabolismo , Orientia tsutsugamushi/inmunología , Rickettsia/inmunología , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Antígenos Bacterianos/farmacología , Línea Celular , Células Cultivadas , Femenino , Linfocitos/microbiología , Macrófagos Peritoneales/microbiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Tifus por Ácaros/metabolismo , Tifus por Ácaros/microbiología , Bazo/citología
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