RESUMO
The synthetic single- and double-stranded polynucleotides, poly I, poly C, and poly I.C, were shown to induce thymidine incorporation in six inbred strains of murine spleen cells. This stimulation was shown to be secondary to B-cell activation and not due to contamination of the polynucleotides with bacterial lipopolysaccharide (LPS). The ability of poly I.C to act as a B-cell mitogen, in addition to its behavior as a thymic-independent antigen, suggested that these two phenomena may be related. The similarity of the molecular structure of poly I.C to LPS, a material which also acts as a thymic-independent antigen and a B-cell mitogen, supports the hypothesis that the polyvalent nature of these materials accounts for their functional interaction with murine B cells.
Assuntos
Linfócitos B/crescimento & desenvolvimento , Divisão Celular , Mitógenos , Poli I-C/farmacologia , Baço/citologia , Animais , Antígenos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Soros Imunes , Camundongos , Camundongos Endogâmicos DBA , Baço/imunologia , Timectomia , Timidina/metabolismo , Timo/imunologia , TrítioRESUMO
Efforts to stimulate lymphocytes from measles seropositive and two patients with subacute sclerosing panencephalitis (SSPE) with either commercially available measles virus or virus isolated from a known case of SSPE failed to show any significant data using a microculture assay. Similar results were obtained using lymphocytes from two patients with active cytomegalovirus (CMV) infections and CMV seropositive individuals using CMV suspensions. On the other hand, lymphocytes from the patients with subacute sclerosing panencephalitis exhibited in vitro blastogenesis in culture with SSPE virus-infected HeLa cells. Similarly, lymphocytes from the CMV-infected patients demonstrated blastogenesis when cocultivated with CMV-infected WI-38 cells. This affords a new method for determining the cell-mediated immune capacity of patients with "slow" virus diseases.
Assuntos
Formação de Anticorpos , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Linfócitos/imunologia , Vírus do Sarampo/imunologia , Panencefalite Esclerosante Subaguda/imunologia , Animais , Linhagem Celular , Células HeLa/imunologia , Humanos , Imunidade Celular , Ativação Linfocitária , Fatores Inibidores da Migração de Macrófagos/análise , Macrófagos/imunologia , Camundongos , Timidina/metabolismo , TrítioRESUMO
Conflicting reports on the immune responsiveness of patients with subacute sclerosing panencephalitis (SSPE) have been reported. This report shows that the leucocytes from four SSPE patients exhibited strong sensitivity to both measles and SSPE virus preparations as measured by the macrophage migration inhibition test, mixed lymphocyte virus infected cell culture test, and the lymphotoxin assay. Earlier suggestions that a factor may be operating to suppress cellular reactivity are confirmed by the demonstration that the response of lymphocytes from SSPE patients could be blocked by the addition of SSPE spinal fluid or plasma. It was determined that the blocking factor was stable at -20 degrees C, heat labile at 56 degrees C for 30 minutes, trypsin and neuraminadase sensitive, and had a mol wt greater than 150,000 as determined by Sephadex G-200 gel chromatography. The blocking factor appeared to be specific for SSPE virus and did not block the response of lymphocytes to nonspecific mitogenic agents and other viral and bacterial agents.
Assuntos
Anticorpos/isolamento & purificação , Vírus do Sarampo/imunologia , Panencefalite Esclerosante Subaguda/imunologia , Anticorpos Antivirais/isolamento & purificação , Especificidade de Anticorpos , Complexo Antígeno-Anticorpo , Antígenos Virais , Inibição de Migração Celular , Células Cultivadas , Cromatografia em Gel , Humanos , Ativação Linfocitária , Linfócitos/imunologia , Linfotoxina-alfa , Fatores Inibidores da Migração de Macrófagos , Panencefalite Esclerosante Subaguda/sangue , Panencefalite Esclerosante Subaguda/líquido cefalorraquidianoRESUMO
Human peripheral blood lymphocytes (PBL) were evaluated by their responses to phytohemmagglutinin (PHA-P), concanavallin A (con-A), and pokeweed mitogen (PWM), both before and after treatment with an antiserum against human thymic lymphocyte antigens (HTLA) that had been made T-cell-specific by multiple absorptions with immunoglobulin EAC-positive lymphoblast cell lines (B cells). Cells treated with HTLA were examined for their ability to react in a mixed lymphocyte culture (MLC) and to form killer cells in a cell-mediated lymphocytotoxicity (CML) system. Sensitized cells were also examined for their ability to respond to purified protein derivative (PPD) by blastogenesis, migration inhibitory factor release (MIP), and lymphotoxin (LT) production, both before and after treatment with HTLA and complement. The HTLA was in itself highly stimulatory to PBL. However, with the addition of complement and subsequent cell destruction, a marked decrease in its stimulatory response was noted. PBL treated with HTLA and complement exhibited marked inhibition of responsiveness to con-A with little decrease in PHA-P -OR PWM stimulation except at very high concentration of HTLA. MLC reaction was inhibited only when responder cells were treated with HTLA + C'. Treatment of stimulator cells with HTLA + C' did not significantly alter the MLC response. The HTLA + C'-treated cells failed to form killer cells in the CML reaction and inhibited PPD-induced blasto-genesis from PPD-sensitized individuals; however, treatment of sensitized cells with HTLA + C' had little effects on the release of MIF and LT. It is suggested that subpopulations of T-cells carry surface antigens that bind with this specific antisera, and that the con-A-responsive cells, the responder cells in the MLC, and killer T-cells comprise a separate subset from cells responding to PHA-P or PWM, OR THE MIF-and LT-producing cells.
Assuntos
Soro Antilinfocitário , Linfócitos T/imunologia , Animais , Linhagem Celular , Proteínas do Sistema Complemento , Concanavalina A , Testes Imunológicos de Citotoxicidade , Teste de Histocompatibilidade , Humanos , Reação de Imunoaderência , Imunoglobulinas , Técnicas In Vitro , Lectinas , Leucemia Linfoide , Ativação Linfocitária , Linfotoxina-alfa/biossíntese , Fatores Inibidores da Migração de Macrófagos/metabolismo , Mitógenos , Extratos Vegetais , Coelhos/imunologia , Linfócitos T/metabolismo , TuberculinaRESUMO
The effect of azathioprine on in vitro baboon lymphocyte function tests was evaluated using the mitogen stimulation test, the mixed lymphocyte culture test, the migration inhibition factor test, the cell-mediated lymphocytotoxicity test and the antibody dependent cell-mediated cytotoxicity test. It was found that azathioprine inhibited phytohemagglutinin and Concanavalin A stimulation at lower concentrations than those required to inhibit pokeweed mitogen stimulation. It inhibited the MLC reaction with as little as 0.2 mug/culture in the microculture system. Azathioprine had no effect on (a) the release of migration inhibition factor, (b) the cell-mediated lymphocytotoxicity assay if presensitized cells were used, and (c) the antibody-dependent cell-mediated cytotoxicity assay. However, azathioprine inhibited CML if it was added during in vitro sensitization and induction of killer cells. These in vitro results suggest that azathioprine inhibits those reactions which require cellular division.
Assuntos
Azatioprina/farmacologia , Terapia de Imunossupressão , Linfócitos/efeitos dos fármacos , Animais , Especificidade de Anticorpos/efeitos dos fármacos , Testes Imunológicos de Citotoxicidade , Haplorrinos , Imunidade Celular/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Teste de Cultura Mista de Linfócitos , Linfócitos/imunologia , Fatores Inibidores da Migração de Macrófagos/biossíntese , PapioRESUMO
Cell-mediated immunity to cytomegalovirus (CMV) was studied in a bone marrow transplant patient with evidence of active CMV infection. The lymphocytes from this patient were found to specifically recognize and respond in vitro by transformation to CMV-infected Wistar-38 fibroblasts and by production of macrophage migration inhibition factor to CMV antigen. In addition, plasma and spinal fluid from the patient were found to contain blocking factor that specifically inhibited the lymphocyte response in the above assays. Biochemical, biophysical, and immunological studies indicate that the blocking factor may be an antigen-antibody complex.
Assuntos
Transplante de Medula Óssea , Citomegalovirus/imunologia , Adolescente , Antígenos Virais , Feminino , Humanos , Imunidade Celular , Fatores Inibidores da Migração de Macrófagos/biossíntese , Vidarabina/uso terapêuticoRESUMO
Injection of the synthetic lipid amine, Avridine, in the form of liposomes, protected guinea pigs against the development of lesions from foot-and-mouth disease virus (FMDV) inoculated intradermally into the rear footpads. The animals were protected against the development of vesicles at the inoculation site as well as the systemic spread of virus. Maximal protection was obtained after intracardial injection of 5-10 mg doses of liposomal Avridine. Lower doses yielded decreased protection. Subcutaneous or intraperitoneal routes of liposomal Avridine injection were ineffective. Protection was maximal 0-24 h after injection of liposomes. Ethanol and emulsion formulations of Avridine could induce protection when injected intracardially but had toxic side effects. Guinea pigs protected against the first FMDV inoculation by liposomal and ethanol formulations of Avridine continued to be protected against lesions after a second inoculation 15-45 days later. FMDV protective antibody titers of these animals ranged from a low of less than 1:10 to greater than 1:1000.
Assuntos
Aphthovirus/efeitos dos fármacos , Diaminas/uso terapêutico , Febre Aftosa/prevenção & controle , Lipossomos/administração & dosagem , Animais , Anticorpos Antivirais/análise , Aphthovirus/imunologia , Diaminas/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Febre Aftosa/tratamento farmacológico , Febre Aftosa/imunologia , Cobaias , Poli I-C/uso terapêuticoRESUMO
Six methods of chemically coupling proteins to red blood cells were evaluated for their effectiveness in coupling foot-and-mouth disease virus (FMDV) to sheep red blood cells. The coupling agents tested were potassium periodate, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (ECDI), chromium chloride, glutaraldehyde, bis-diazotized benzidine (BDB) and N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). Of these, only the coupling methods using BDB and SPDP resulted in virus-red cell complexes that reacted with FMDV antiserum in passive hemagglutination and passive immune hemolysis assays. The BDB and SPDP methods were studied further to determine optimal coupling conditions, the kinetics of coupling and the effects of chemical couplers on viral integrity. Only the FMDV-red cell complexes formed with SPDP were suitable targets for detecting FMDV antibody producing lymphocytes in a hemolytic plaque assay.
Assuntos
Aphthovirus/imunologia , Linfócitos B/imunologia , Cloretos , Compostos de Cromo , Eritrócitos , Testes de Hemaglutinação , Técnica de Placa Hemolítica , Compostos de Potássio , Animais , Anticorpos Antivirais/biossíntese , Antígenos Virais , Benzidinas/farmacologia , Cromo/farmacologia , Cricetinae , Eritrócitos/efeitos dos fármacos , Eritrócitos/imunologia , Eritrócitos/metabolismo , Etildimetilaminopropil Carbodi-Imida/análogos & derivados , Etildimetilaminopropil Carbodi-Imida/farmacologia , Glutaral/farmacologia , Cobaias , Cinética , Camundongos , Ácido Periódico/farmacologia , Ovinos/sangue , Succinimidas/farmacologia , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismoRESUMO
This article presents an expanded agent summary statement for laboratorians working with Mycobacterium tuberculosis. It focuses on reducing the serious risk of infection in clinical laboratories that process specimens from tuberculosis patients or that work with purified cultures of tubercle bacilli. Administrative and engineering controls, practices and procedures, and personal protective equipment are discussed. Guidelines for packaging specimens for transfer to another laboratory also are presented.
Assuntos
Bacteriologia/normas , Laboratórios/normas , Infecções por Mycobacterium/prevenção & controle , Segurança , Tuberculose Pulmonar/prevenção & controle , Contenção de Riscos Biológicos , Humanos , Eliminação de Resíduos de Serviços de Saúde , Mycobacterium tuberculosis , Equipamentos de Proteção , Fatores de RiscoRESUMO
Foot-and-mouth disease virus (FMDV)-induced ultrastructural changes in guinea-pig tongue, heelpad, mammary and liver tissues were examined using scanning and transmission electron microscopy. FMDV infection caused cell rounding and the release of virus in membrane limited vesicles in the animal tissues similar to that seen in other work in cell cultures. Microfilaments were present which may be responsible for cell rounding. Immunoperoxidase labeling revealed the attachment of the virus-infection associated (VIA) antigen to the smooth vacuoles of mammary and liver tissues, and to milk fat globules. The electron microscope immunoperoxidase procedure increased the sensitivity of detection sufficiently to allow the visualization of VIA antigen in tissues not previously shown to have the antigen. It is postulated that the release of the smooth vacuoles from the liver cells stimulates the animal's immune response to the VIA antigen.
Assuntos
Febre Aftosa/patologia , Fígado/ultraestrutura , Glândulas Mamárias Animais/ultraestrutura , Língua/ultraestrutura , Tecido Adiposo/ultraestrutura , Animais , Antígenos Virais/análise , Aphthovirus/imunologia , Aphthovirus/ultraestrutura , Feminino , Febre Aftosa/microbiologia , Cobaias , Técnicas Imunoenzimáticas , Corpos de Inclusão Viral/ultraestrutura , Microscopia EletrônicaRESUMO
Swine cells of the monocyte/macrophage lineage (MM) proliferate and survive for several weeks in vitro in medium supplemented with the murine macrophage-specific hematopoietic growth factor, colony-stimulating factor 1 (CSF-1). The extent to which MM, cultured in CSF-1, supported African swine fever virus (ASFV) growth in vitro was investigated. MM, cultured in medium with CSF-1, were sensitive to infection and viral-induced cytopathogenic damage by both natural field isolates of ASFV and fibroblast-adapted ASFV strains, as were primary MM (P-MM). Without CSF-1, blood mononuclear leukocytes (MNL), containing lymphocytes and MM, and P-MM could be reliably used in microculture for ASFV titration when inoculated at times limited to no more than 3 to 5 days after culture inception; inclusion of CSF-1 in the media stimulated continued MM survival and growth, and allowed for the use of MNL and P-MM for ASFV titration when inoculated as long as 2 to 3 weeks after microculture inception. MM that were propagated beyond 1 week in secondary culture in medium with CSF-1 (MM-CSF) were useful in microcultures for infective-ASFV titration, only when the cells were kept in medium with CSF-1 and inoculated no later than 3 days of culture inception. In vitro studies of ASFV infection in P-MM and in MM-CSF showed comparable kinetics in ASFV-induced hemadsorption (HAd), cytopathogenic effect (CPE), cytoplasmic viral antigens and nucleic acid material. Compared to P-MM in culture without CSF-1, relatively minor delays in CPE onset induced by some ASFV strains were noticed in MM-CSF and in P-MM that were placed in media with CSF-1. The effects of ASFV on DNA synthesis in the virus-susceptible MM, cultured with or without CSF-1, were also examined at different times of infection by measurement of 3H-thymidine (3H-TdR) incorporation into total precipitable culture material. ASFV-infection of P-MM, placed in culture medium with CSF-1, caused a pronounced transient increase in total 3H-TdR incorporation at the early onset of CPE and HAd. When compared to uninfected P-MM that were stimulated by CSF-1 to synthesize DNA, infected P-MM failed to incorporate 3H-TdR after CPE was fully evident. For P-MM that were cultured without CSF-1 and for MM-CSF, that were kept in culture with CSF-1, transient increases in 3H-TdR incorporation at the onset of CPE and HAd by ASFV-infection were evident, but were much less pronounced.
Assuntos
Vírus da Febre Suína Africana/crescimento & desenvolvimento , Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/microbiologia , Monócitos/microbiologia , Vírus da Febre Suína Africana/efeitos dos fármacos , Vírus da Febre Suína Africana/imunologia , Animais , Antígenos Virais/análise , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Meios de Cultura , Efeito Citopatogênico Viral , DNA/biossíntese , DNA Viral/análise , Hemadsorção , Cinética , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/microbiologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Microscopia de Fluorescência , Monócitos/citologia , Monócitos/efeitos dos fármacos , Radioimunoensaio , Inoculações Seriadas , SuínosRESUMO
A microculture assay is described for the titration of African swine fever virus (ASFV) using swine monocytes contained in mononuclear leucocyte (MNL) microcultures. Titration endpoints were determined by observing cytopathogenic effects (CPE) of ASFV infected monocytes with an inverted microscope at 40 X magnification. CPE was a late event following the detection of ASFV antigens in monocytes by radioimmune assay, immunofluorescence and hemadsorption. It began with the detachment, enlargement and rounding of monocytes which progressively formed into grape-like clusters of 3-20 or more cells which eventually lysed. The characteristic CPE was produced in monocyte microcultures by virulent, moderately virulent, Vero cell adapted, and nonhemadsorbing ASFV strains. The sensitivity and reproducibility of the CPE microassay was similar to that of the hemadsorption microassay.
Assuntos
Vírus da Febre Suína Africana/crescimento & desenvolvimento , Iridoviridae/crescimento & desenvolvimento , Monócitos/microbiologia , Vírus da Febre Suína Africana/patogenicidade , Animais , Células Cultivadas , Efeito Citopatogênico Viral , Imunofluorescência , Hemadsorção , Radioimunoensaio , Suínos , Células Vero , VirulênciaRESUMO
Six pigs were infected oro-nasally with a moderately virulent African swine fever (ASF) virus from the Dominican Republic (DR II). The effect of virus infection on the pig's immune system was tested by measuring peripheral leucocyte numbers and the ability of mononuclear leucocytes (MNL) to respond by lymphocyte proliferation (LP) to the mitogens phytohemagglutinin-P (PHA-P), concanavalin-A (Con-A), and pokeweed mitogen (PWM). All 6 pigs developed high viremias between 4 and 18 days post-inoculation (DPI) which became undetectable by 32 to 46 DPI. Virus was found in erythrocytes, plasma, and mononuclear leucocytes from peripheral blood. Overall, virus infection had only minor effects on the number of circulating leucocytes, lymphocytes, monocytes and granulocytes. At the early acute phase of infection slight neutrophilia and lymphocytopenia were observed with mildly elevated monocyte numbers and slightly depressed neutrophil numbers that continued from the time of evident reduction in viremia to beyond the period of viral clearance. The infected pigs readily produced high titers of ASF virus antibody shortly after the onset of viremia. No significant differences in LP responses of MNL from the 6 pigs to PHA-P, Con-A and PWM were observed after infection when compared to those obtained with MNL from normal pigs. The in vitro addition of infectious ASF virus to MNL from normal pigs did not affect LP responses to any of the three mitogens. These results do not support the hypothesis that immunosuppression is a consequence of ASFV infection of pigs.
Assuntos
Vírus da Febre Suína Africana/imunologia , Febre Suína Africana/imunologia , Iridoviridae/imunologia , Ativação Linfocitária , Vírus da Febre Suína Africana/patogenicidade , Animais , Anticorpos Antivirais/biossíntese , Eritrócitos/microbiologia , Granulócitos , Tolerância Imunológica , Contagem de Leucócitos/veterinária , Linfócitos/imunologia , Linfócitos/microbiologia , Mitógenos , Monócitos , Neutrófilos , Radioimunoensaio , Suínos , Viremia/imunologia , Viremia/veterinária , VirulênciaRESUMO
The addition of conditioned medium from murine L929 fibroblasts (MGF) to cultures of swine peripheral blood mononuclear cells (MNL) resulted in growth of cells of macrophage/monocyte lineage (MO). Glass-adherent swine MNL, shown to be greater than 95% phagocytic MO, grew in the presence of MGF, whereas swine blood granulocytes and lymphocytes were not MGF-responsive. Primary and secondary MO growth were directly dependent on MGF presence and concentration. MGF-stimulated MO synthesized DNA, as measured by cellular incorporation of tritium-labeled thymidine (3H-TdR). This mitogenic response was maximal by 5 to 6 days in primary MO cultures and declined thereafter to a lower magnitude in secondary MO cultures. In the presence of MGF, viable MO numbers increased with an approximate population doubling time of 5 to 7 days in primary culture. This growth rate was prolonged, to about 10 to 12 days, for MGF-stimulated MO in secondary cultures. MGF removal from primary and secondary MO cultures resulted in rapid growth cessation and cell death. MGF-stimulated MO could not be sustained in secondary culture beyond 7 weeks. MGF-cultured MO were positive for latex phagocytosis, non-specific esterase, Fc-receptor expression, and could mediate antibody-dependent cell-mediated cytotoxicity. The MO-mitogenic principle of MGF was identified as the murine, macrophage-specific colony-stimulating factor, CSF-1 (M-CSF). The swine MO-proliferative response to MGF was inhibited by addition of monospecific goat antisera to M-CSF. Purified M-CSF stimulated the growth of swine MO from cultures of MNL and primary glass-adherent MO.
Assuntos
Fatores Estimuladores de Colônias/farmacologia , Monócitos/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular , Fatores Estimuladores de Colônias/isolamento & purificação , Meios de Cultura , Técnicas In Vitro , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Fator Estimulador de Colônias de Macrófagos , Camundongos , Monócitos/citologia , Monócitos/imunologia , SuínosRESUMO
Serum samples from pigs that had recovered from infection with a Dominican Republic isolate of African swine fever virus (ASFV) were mixed with dilutions of the virus, then assayed in microcultures of normal pig mononuclear leukocytes to determine whether the samples contained antibodies that protected monocytes against the virus. Protection was determined by the difference in titer (log10) between virus mixed with healthy pig serum and virus mixed with immune pig serum, using 50% cytopathogenic effect end points; protection was expressed as an immune serum-protection index. After addition of virus-serum mixtures to mononuclear leukocyte microcultures, a time-dependent decrease in protective index and production of infectious virus (determined by use of yield reduction assays) were observed. Protective effects were associated with the immunoglobulin fraction of serum, were rapidly lost on dilution, and were independent of complement. Antibody was most protective for the homologous Dominican Republic isolate of ASFV, with decreased protection against Lisbon '60 ASFV, and no protection against foot-and-mouth disease virus or bluetongue virus. Low concentrations of protective antibody were found during the acute viremic phase in infected pigs; antibody increased to maximal concentrations as the viremia decreased.
Assuntos
Febre Suína Africana/prevenção & controle , Soros Imunes/imunologia , Monócitos/microbiologia , Suínos/sangue , Febre Suína Africana/imunologia , Animais , Técnicas In Vitro , Valores de ReferênciaRESUMO
Blood samples of pigs infected with a moderately virulent African swine fever virus (ASFV) isolate, obtained from the Dominican Republic (DR-II), were monitored temporally for viremia, infective ASFV association with major blood components, differential changes in blood cell composition, and plasma antibodies to ASFV. After intranasal/oral virus inoculation, pigs underwent acute infection and illness that resolved. Acute illness began on postinoculation day (PID) 4 and continued to PID 11, and pigs were febrile, with maximal infective ASFV titers detected in blood. By PID 11, initial antibody titers to ASFV antigens were detected in plasma. The WBC numbers were maintained near preinoculation counts; however, lymphocyte counts decreased slightly with a compensatory increment in neutrophil and monocyte numbers. From PID 11 to PID 25, rectal temperatures gradually returned to preinoculation values, titers of viremia began to decrease, plasma antibody to ASFV antigens increased to peak titers, and WBC numbers increased slightly. Percentages of lymphocytes returned to preinoculation values, neutrophil percentages decreased to slightly below preinoculation values, monocyte percentages were mildly increased, and eosinophil percentages were unaffected. From PID 25 to PID 46, titers of viremia further decreased, and plasma titers of antibodies to ASFV antigens remained high. In pigs with DR-II viremia (PID 4 to PID 46), most viral infectivity (greater than 95%) was RBC associated. Plasma contained less than 1% infectivity, and less than 0.1% of virus was in the WBC fraction (monocytes, lymphocytes, and granulocytes). After PID 46, viremia was no longer detectable.
Assuntos
Febre Suína Africana/sangue , Doenças dos Suínos/microbiologia , Viremia/veterinária , Doença Aguda , Febre Suína Africana/microbiologia , Vírus da Febre Suína Africana/crescimento & desenvolvimento , Vírus da Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/patogenicidade , Animais , Anticorpos Antivirais/biossíntese , República Dominicana , Contagem de Eritrócitos/veterinária , Feminino , Febre/veterinária , Contagem de Leucócitos/veterinária , Linfócitos , Monócitos , Neutrófilos , Suínos , Células Vero , Viremia/microbiologia , VirulênciaRESUMO
Foot-and-mouth disease virus (FMDV) is the etiologic agent of foot-and-mouth disease (FMD), which is a disease of cattle, swine, and other cloven-footed animals. FMD is characterized by the formation of vesicles on the tongue, nose, muzzle, and coronary bands of infected animals. The virus has several unique characteristics that enable it to cause one of the most economically devastating diseases in today's world. The ease with which it may be transmitted by contact and aerosol, combined with its enhanced ability to initiate infections, virtually ensures that most, if not all, animals in a herd will contract FMD. The long-term survival of FMDV in infected animals' tissues and organs, especially when refrigerated, offers an opportunity for its national and international transmission through the food chain. Multiple serotypes and numerous subtypes reduce the effectiveness and reliability of vaccines. The possible development of carriers in vaccinated animals and those that have recovered from FMD provides additional potential sources of new outbreaks. These features create a disease that can have a major economic impact on farmers and entire nations.
Assuntos
Vírus da Febre Aftosa/patogenicidade , Febre Aftosa/virologia , Aerossóis , Agricultura , Animais , Bovinos , Febre Aftosa/patologia , Febre Aftosa/transmissão , Vírus da Febre Aftosa/classificação , Sorotipagem , Suínos , Vacinação/veterináriaAssuntos
Anticorpos Antivirais/análise , Aphthovirus/imunologia , Cobaias/imunologia , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Animais , Feminino , Pé/imunologia , Febre Aftosa/imunologia , Doenças dos Roedores/imunologia , Suínos , Doenças dos Suínos/imunologia , Língua/imunologia , Vacinação/métodos , Vacinas Virais/imunologiaRESUMO
S-Adenosylhomocysteine (SAH) hydrolase was purified 25-fold from bakers' yeast by chemical methods and column chromatography. The purified enzyme could readily synthesize SAH from adenosine and homocysteine, but could hydrolyze only negligible amounts of SAH. The purified enzyme showed no activity towards S-adenosylmethionine, methylthioadenosine, or adenosine. Several nucleotides, sulfhydryl compounds, and ribose could not replace adenosine or homocysteine in the reaction mixture. SAH could be hydrolyzed by SAH hydrolase if commercial adenosine deaminase was included in the reaction mixture. Under these conditions l-homocysteine could act as a product inhibitor. A number of compounds structurally similar to adenosine and homocysteine were found to inhibit synthesis of SAH from adenosine and homocysteine. The strongest inhibitors were adenine, adenosine-3'-monophosphate, adenosine-2'-monophosphate, adenosine diphosphate, adenosine triphosphate, and adenosine-5'-monophosphate. The biosynthetic and hydrolytic activity of SAH hydrolase in yeast cell ghosts was similar to the activity of the enzyme in vitro.