Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Drug Alcohol Depend ; 178: 165-169, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28651152

RESUMO

BACKGROUND AND AIMS: Methylphenidate (MPH) is a prescription stimulant used to treat attention-deficit hyperactivity disorder. MPH is currently the preferred substance among most intravenous (i.v.) substance users in Iceland. Four types of MPH preparations were available in Iceland at the time of study: Immediate-release (IR), sustained-release (SR), osmotic controlled-release oral delivery (OROS) tablet and osmotic-controlled release (OCR). MPH OROS has previously been rated the least desirable by i.v. users and we hypothesized that this was associated with difficulty of disintegrating MPH from OROS formulation. The aim of the study was to measure the amount of MPH and the viscosity of the disintegrated solutions that were made from the four MPH formulations by four i.v.-users and non-users. METHODS: A convenience sample of four i.v. substance users and 12 non-users. Non-users imitated the methods applied by experienced i.v. substance users for disintegrated MPH formulations. RESULTS: Both groups managed to disintegrate over 50% of MPH from IR and SR formulations but only 20% from OROS (p<0.0001). The viscosity of the disintegrated MPH was significantly higher for MPH OROS and MPH OCR and the preparation was significantly more time-consuming than for the other MPH samples. No differences were observed between users and non-users. CONCLUSIONS: To our knowledge, this is the first investigation of viscosity and the amount of disintegrated MPH from prescription drugs for i.v. use. The results indicate that the ease of disintegration, amount of MPH and viscosity may explain the difference in popularity for i.v. use between different MPH formulations.


Assuntos
Metilfenidato/administração & dosagem , Metilfenidato/metabolismo , Abuso de Substâncias por Via Intravenosa/metabolismo , Abuso de Substâncias por Via Intravenosa/psicologia , Administração Intravenosa , Administração Oral , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estimulantes do Sistema Nervoso Central/metabolismo , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/metabolismo , Usuários de Drogas/psicologia , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Abuso de Substâncias por Via Intravenosa/diagnóstico , Comprimidos , Resultado do Tratamento , Viscosidade
3.
Virus Genes ; 16(3): 281-93, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9654682

RESUMO

During the epidemic caused by maedi-visna virus (MVV) of sheep in Iceland, the pulmonary affection, maedi, was the predominant clinical manifestation. In some flocks, however, a central nervous system (CNS) affection, visna, was the main cause of morbidity and mortality. As there is only one breed of sheep in the country, host factors did apparently not play an important role in the different clinical manifestations. To obtain some information on possible viral genetic determinants of neurotropism and neurovirulence we studied both phenotypic and genotypic properties of two maedi-visna virus strains; a strain that was originally isolated from the brain of sheep with encephalitis (visna), and another strain isolated from the lungs of a sheep suffering from pneumonia (maedi). The brain isolate was found to grow faster in sheep choroid plexus cells than the lung isolate, whereas the growth rate in macrophages was similar for the maedi and visna virus strains. Intracerebral inoculation indicated that the visna virus isolate induced more severe brain lesions than the maedi isolate. In addition, a pathogenic molecular clone derived from a visna strain (KV1772kv72/67) was tested for growth in sheep choroid plexus cells and macrophages. The molecularly cloned virus retained the fast growth rate in choroid plexus cells. The nucleotide sequence of the env gene and the U3 of the LTR was determined for the maedi strain and compared to that of the visna strains. There was an 11.7% difference in deduced amino acid sequence in the Env protein and a 6% difference in the LTR. The molecular clone KV1772kv72/67 will be a useful reagent for characterization of viral determinants of cell tropism in vitro and possibly neurovirulence in vivo.


Assuntos
Encéfalo/virologia , Pulmão/virologia , Pneumonia Intersticial Progressiva dos Ovinos/virologia , Vírus Visna-Maedi/genética , Visna/virologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/patologia , Linhagem Celular , DNA Viral , Feminino , Genes env , Injeções , Pulmão/patologia , Macrófagos/virologia , Dados de Sequência Molecular , Pneumonia Intersticial Progressiva dos Ovinos/patologia , Sequências Repetitivas de Ácido Nucleico , Ovinos , Visna/patologia , Vírus Visna-Maedi/crescimento & desenvolvimento
4.
J Immunol Methods ; 211(1-2): 171-81, 1998 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9617841

RESUMO

A new in vitro method is presented for measuring directly the ability of sera to induce binding of immune complexes (ICs) to erythrocytes (ICRB assay). The assay measures the binding of alkaline phosphatase (AP)-anti-alkaline phosphatase (anti-AP) complexes formed in the presence of the test sera to the complement receptor 1 (CR1) on normal human red blood cells (RBCs). By using a standard serum source, the assay can also be used to measure the IC binding ability of RBCs from different donors. As compared to the traditional CH50 method, the ICRB assay generally showed more pronounced abnormality in 10 individuals tested, of whom 5 had primary deficiency of classical pathway components. Seven out of ten individuals had systemic lupus erythematosus (SLE) and 2/10 had other rheumatic diseases without primary complement deficiency. The ICRB measured in samples from 9 other patients with SLE was significantly decreased when compared to values from 80 normal individuals. ICRB in serum samples from a C2 deficient SLE patient collected during plasma infusion treatment reflected closely the rising amount of C2 in the serum. Using RBCs from different donors ICRB activity correlated well with the numbers of CR1 as measured by a flow cytometric assay (FCA). These methods should be valuable for measuring the overall IC clearance capacity of the blood and have the advantage that the use of radioactive isotopes is avoided.


Assuntos
Complexo Antígeno-Anticorpo/imunologia , Proteínas do Sistema Complemento/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Eritrócitos/imunologia , Receptores de Complemento 3b/imunologia , Animais , Ensaio de Imunoadsorção Enzimática/normas , Cobaias , Humanos , Cinética , Lúpus Eritematoso Sistêmico/imunologia , Sistema do Grupo Sanguíneo Rh-Hr/imunologia , Doenças Reumáticas/imunologia , Fator Reumatoide/imunologia
5.
Virus Res ; 53(2): 107-20, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9620203

RESUMO

Two different recombinant visna virus (VV) gag-baculoviruses were constructed for the expression of precursor VV Gag in insect cells. Both recombinant Gag viruses expressed proteins migrating on SDS PAGE at the predicted rate for VV Gag precursor, Pr50gag. However, differences were seen in the morphology of the virus-like particles produced. Monoclonal antibody directed against the VV Gag capsid protein (p25) and sera from sheep infected with ovine lentiviruses reacted to both 50-kDa proteins. A recombinant VV env-baculovirus was constructed, substituting sequences encoding the signal peptide of VV Env with the murine IFN-gamma analogue. Sera from ovine lentivirus infected sheep reacted in immunoblots with two proteins of approximately 100 and 200 kDa found in the plasma membrane of insect cells infected with env-recombinant virus. Sheep immunized with either the recombinant Gag or the Env proteins developed high antibody titers to VV in ELISA. The serum of sheep and ascitic fluid of mice immunized with the recombinant Gag reacted with native Pr50gag and the processed Gag proteins in immunoblots, whereas serum of the recombinant Env immunized sheep reacted with VV gp135 and a putative oligomer of gp135. The immunized sheep responded specifically to visna virus by lymphocyte proliferation in vitro.


Assuntos
Produtos do Gene env/imunologia , Produtos do Gene gag/imunologia , Precursores de Proteínas/imunologia , Vírus Visna-Maedi/imunologia , Animais , Linhagem Celular , Produtos do Gene env/genética , Produtos do Gene gag/genética , Imunização , Immunoblotting , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Precursores de Proteínas/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Ovinos , Spodoptera
6.
Arthritis Rheum ; 41(3): 427-34, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9506570

RESUMO

OBJECTIVE: To investigate whether participation of factor B (FB) in immune complex transport might explain long periods of clinical remissions in a homozygous C2-deficient patient with systemic lupus erythematosus (SLE) treated regularly with plasma infusions. METHODS: Immune complex red cell binding (ICRB) was assayed as enzyme activity, C3d by enzyme-linked immunosorbent assay, and FB by immunoelectrophoresis. RESULTS: C2-deficient sera showed low-grade ICRB, which correlated with levels of FB. This activity could be blocked with antibodies to C1q, C4, or FB, but not by antibodies to C2. C3d levels in the patient's plasma changed during infusion, followed by a gradient increase during remission. Comparison of ICRB, C3d, and FB suggested an inverse relationship between FB levels and clinical symptoms. CONCLUSION: In C2 deficiency, FB may interact with C4 to provide a low-grade ICRB. This activity could be clinically significant in patients with C2 deficiency and explain why they are less prone to SLE than patients with C1q or C4 deficiency.


Assuntos
Complexo Antígeno-Anticorpo/fisiologia , Complemento C2/deficiência , Fator B do Complemento/fisiologia , Eritrócitos/fisiologia , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/fisiopatologia , Anticorpos/imunologia , Complemento C1q/imunologia , Complemento C4/imunologia , Fator B do Complemento/imunologia , Humanos , Fatores de Tempo
7.
Virology ; 229(2): 370-80, 1997 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-9126250

RESUMO

The behavior of two genetically different molecular clones of visna virus KV1772-kv72/67 and LV1-1KS1 was compared in vivo and in vitro. On intracerebral inoculation, clone KV1772-kv72/67 induced a similar response in five sheep as has already been reported with neurovirulent derivates of visna virus. Virus was frequently isolated from blood, cerebrospinal fluid (CSF), and lymphoid organs and induced characteristic central nervous system (CNS) lesions. A strong humoral immune response was detected by ELISA, immunoblotting, and neutralization. Six sheep infected with clone LV1-1KS1 showed a completely different picture. No virus could be isolated from blood or CSF during 6 months of infection. At sacrifice all organs were virus-negative except the CNS of one sheep. None of the six sheep developed significant neutralizing antibodies and only low titer antibodies were detected by ELISA and immunoblotting. Minimal CNS lesions were present in one sheep. The molecular clones were also tested in sheep choroid plexus cells (SCP) and macrophages. In macrophages LV1-1KS1 replicated to a significantly lower titer but induced much more cell fusion than KV1772-kv72/67. The clones replicated equally well in SCP cells. Thus, these molecular clones of visna virus, which differ only by 1% in nucleotide sequence, showed a profound difference in replication and pathogenicity both in vitro and in vivo. These results can be used to map viral genetic determinants important for host-lentivirus interactions.


Assuntos
Macrófagos/virologia , Vírus Visna-Maedi/patogenicidade , Visna/virologia , Animais , Anticorpos Antivirais/sangue , Linhagem Celular , Macrófagos/citologia , Ovinos , Visna/imunologia , Visna/patologia , Vírus Visna-Maedi/imunologia , Vírus Visna-Maedi/isolamento & purificação
8.
Ann N Y Acad Sci ; 724: 159-61, 1994 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-8030936

RESUMO

The time course and titers of antibodies did not correlate with the severity of CNS lesions whereas the CMI did, indicating that CMI may play an important role in lesion development. The correlation of the number of CD8 positive cells in the CSF with the severity of lesions and the reversed ratio of CD4/CD8 positive cells in the diffusely infiltrated neuroparenchyma indicates that the CD8 positive T cells may be an important effector cell in the induction of CNS lesions.


Assuntos
Encéfalo/patologia , Doenças do Sistema Nervoso Central/veterinária , Visna/patologia , Animais , Relação CD4-CD8 , Doenças do Sistema Nervoso Central/imunologia , Doenças do Sistema Nervoso Central/patologia , Imunidade Celular , Subpopulações de Linfócitos , Ovinos , Visna/sangue , Visna/líquido cefalorraquidiano , Visna/imunologia
9.
J Neuroimmunol ; 41(2): 149-58, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1334965

RESUMO

There are several indications that central nervous system (CNS) lesions in visna are immune-mediated and that cell-mediated immunity (CMI) may be of importance in the initiation of the lesions. To study the role of CMI in the pathogenesis of CNS lesions, five sheep were infected by intracerebral inoculation with visna virus and observed for 1 year. The following parameters were monitored at regular intervals: (1) neutralizing and ELISA antibodies; (2) visna virus-specific stimulation of lymphocytes from peripheral blood; (3) lymphocyte subpopulations in peripheral blood, cerebrospinal fluid (CSF) and brain at sacrifice. The CNS lesions were graded and compared with other parameters. The time course and titers of antibodies did not correlate with the severity of CNS lesions whereas the CMI did, indicating that CMI may play an important role in lesion development. The correlation of the number of CD8-positive cells in the CSF with the severity of lesions and the reversed ratio of CD4/CD8-positive cells in the diffusely infiltrated neuroparenchyma indicates that the CD8-positive T lymphocyte may be an important effector cell in the induction of CNS lesions.


Assuntos
Anticorpos Antivirais/sangue , Encéfalo/patologia , Subpopulações de Linfócitos T/imunologia , Vírus Visna-Maedi/imunologia , Visna/imunologia , Animais , Encéfalo/imunologia , Relação CD4-CD8 , Líquido Cefalorraquidiano/citologia , Antígenos de Histocompatibilidade Classe I/análise , Antígenos de Histocompatibilidade Classe II/análise , Imunidade Celular , Ovinos , Visna/patologia
10.
J Gen Virol ; 66 ( Pt 10): 2111-24, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2413163

RESUMO

Antigenic variation of human respiratory syncytial (RS) virus strains was analysed using a collection of nine, six, six, nine and one monoclonal antibodies respectively directed against the large glycoprotein (G), fusion protein (F), matrix protein (M), nucleoprotein (NP) and phosphoprotein (P) components of the Long strain of RS virus. A comparison was made with seven other strains isolated during different years in radioimmune precipitation analyses and immune fluorescence tests. Two different subtypes of the virus were demonstrable. Subtype A included the prototype strains Long and A2 and virus isolates from 1973, 1983 and 1984; subtype B included four virus strains isolated in successive years from 1979 to 1982. Subtype A viruses reacted with all the antibodies, whereas subtype B viruses showed different epitope characteristics in four structural components. The number of altered epitopes were 5/6, 1/2, 2/6 and 1/6 in the G, F, M and NP components, respectively. It is concluded that the two subtypes have evolved separately. The finding of two subtypes may explain previously observed strain variations in neutralization tests, and gives a new perspective on the immunobiology of RS virus.


Assuntos
Antígenos Virais/imunologia , Glicoproteínas de Membrana , Vírus Sinciciais Respiratórios/classificação , Anticorpos Monoclonais , Anticorpos Antivirais , Criança , Ensaio de Imunoadsorção Enzimática , Epitopos , Humanos , Lactente , Nucleoproteínas/imunologia , Fosfoproteínas/imunologia , Radioimunoensaio , Vírus Sinciciais Respiratórios/imunologia , Infecções por Respirovirus/microbiologia , Sorotipagem , Proteínas do Envelope Viral/imunologia , Proteínas Virais de Fusão , Proteínas da Matriz Viral , Proteínas Virais/imunologia
11.
Bull World Health Organ ; 60(1): 141-6, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6979417

RESUMO

Of 730 Icelandic schoolgirls, 12 years of age, screened for rubella antibodies by the haemagglutination-inhibition (HI) technique, 372 (50.9%) were found to be seronegative. Rubella vaccine was administered to 355 members of this group, and to 12 girls with an HI titre of 20. Blood samples were taken 6 weeks and 1 year after immunization from 336 previously seronegative girls and from the 12 low-positive vaccinees, and tested for HI antibodies. The seroconversion rate was 99.15%. One year after immunization, 94.8% of the girls tested had an HI antibody titre of 40 or more. The geometric mean titre (GMT) of the previously seronegative girls was 62.07 at 6 weeks and 61.69 at one year after vaccination. Of the girls with an initially low positive titre, only 3 (25%) showed a significant rise. The GMT was 40 at 6 weeks, but fell to 25.2 after 1 year. Re-immunization had no effect on antibody levels in either group.A severe rubella epidemic occurred 2 years after immunization, following which 345 vaccinees and 193 naturally immune controls were studied. All subjects had been exposed to wild rubella virus at school, and rubella cases had occurred in the homes of 116 vaccinees (33.6%) and 41 control subjects (21.2%). Only 5 (1.5%) primarily seronegative vaccinees and 2 unimmunized controls (1%) showed serological evidence of infection during the epidemic.


Assuntos
Imunização , Vacina contra Rubéola , Rubéola (Sarampo Alemão)/prevenção & controle , Adolescente , Feminino , Seguimentos , Humanos , Islândia , Rubéola (Sarampo Alemão)/imunologia
13.
J Med Virol ; 5(4): 303-8, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7014781

RESUMO

A modification of the haemolysis-in-gel test for rubella is described. This involves using, instead of sera, whole blood samples taken from the earlobe and placed directly onto the test plates without any pretreatment. A comparison was made between this method and the HI test. Samples from 461 individuals were tested by both methods. The results of these two tests were in good agreement. No false negatives or false positives were observed by the direct HIG test. The direct HIG test is particularly well suited for screening large groups for rubella antibodies in connection with a vaccination program.


Assuntos
Anticorpos Antivirais/análise , Técnica de Placa Hemolítica , Vírus da Rubéola/imunologia , Adulto , Testes de Inibição da Hemaglutinação , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...