Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
JAMA ; 285(12): 1592-601, 2001 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-11268267

RESUMO

CONTEXT: Allogeneic blood transfusions have immunomodulatory effects and have been associated with activation of human immunodeficiency virus (HIV) and cytomegalovirus (CMV) in vitro and of HIV in small pilot studies. Retrospective studies suggest that transfusions adversely affect the clinical course of HIV. Data in selected non-HIV-infected patients requiring blood transfusion have suggested clinical benefit with leukocyte-reduced red blood cells (RBCs). OBJECTIVE: To compare the effects of leukoreduced and unmodified RBC transfusions on survival, complications of acquired immunodeficiency syndrome, and relevant laboratory markers in HIV-infected patients. DESIGN AND SETTING: Double-blind randomized controlled trial conducted in 11 US academic medical centers from July 1995 through June 1999, with a median follow-up of 12 months (24 months in survivors). PATIENTS: A total of 531 persons infected with HIV and CMV, aged 14 years or older, who required transfusions for anemia; 259 received leukoreduced transfusions and 262 received unmodified transfusions (10 did not receive the planned transfusion). MAIN OUTCOME MEASURES: Survival and change in plasma HIV RNA level 7 days after transfusion, compared by type of transfusion. RESULTS: At entry, the groups were similar in demographic, clinical, and relevant laboratory characteristics. A total of 3864 RBC units were transfused. Two hundred eighty-nine deaths occurred (151 with leukoreduced transfusion; 138 with unmodified transfusion); median survival was 13.0 and 20.5 months, respectively (relative hazard [RH], 1.20; 95% confidence interval [CI], 0.95-1.51; log-rank P =.12). Analyses adjusted for prognostic factors suggested possible worse survival with leukoreduction (RH, 1.35; 95% CI, 1.06-1.72). There was no difference in time to new opportunistic event/death or frequency of transfusion reactions. No changes in plasma HIV RNA level were seen in either group at days 7, 14, 21, or 28, even in patients not taking antiretroviral drugs. There were no differences in trends between groups in CMV DNA, CD4 cell counts, activated (CD38% or human leukocyte antigen-DR) CD8 cell counts, or plasma cytokine levels. CONCLUSIONS: We found no evidence of HIV, CMV, or cytokine activation following blood transfusion in patients with advanced HIV infection. Leukoreduction provided no clinical benefit in these patients. These data demonstrate the importance of conducting controlled studies of effects of leukoreduction in different patient populations, since smaller studies in other patient populations have suggested leukoreduction may be beneficial.


Assuntos
Anemia/complicações , Anemia/terapia , Transfusão de Eritrócitos , Infecções por HIV/complicações , Infecções por HIV/imunologia , Infecções Oportunistas Relacionadas com a AIDS/complicações , Infecções Oportunistas Relacionadas com a AIDS/imunologia , Adulto , Anemia/imunologia , Contagem de Linfócito CD4 , Citocinas/sangue , Citomegalovirus/genética , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/imunologia , DNA Viral/análise , Método Duplo-Cego , Transfusão de Eritrócitos/métodos , Feminino , Infecções por HIV/fisiopatologia , Humanos , Leucócitos , Subpopulações de Linfócitos , Masculino , Estudos Prospectivos , Análise de Sobrevida , Carga Viral , Ativação Viral
2.
J Virol ; 74(9): 4127-38, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10756025

RESUMO

The long-term efficacy of combination antiretroviral therapy may relate to augmentation of anti-human immunodeficiency virus type 1 (HIV-1) CD8(+) T-cell responses. We found that prolonged treatment of late-stage HIV-1-infected patients with a protease inhibitor and two nucleoside reverse transcriptase inhibitors failed to restore sustained, high levels of HIV-1-specific, HLA class I-restricted, cytotoxic-T-lymphocyte precursors and gamma interferon (IFN-gamma) production by CD8(+) T cells. In some patients, particularly those initiating three-drug combination therapy simultaneously rather than sequentially, there were early, transient increases in the frequency of anti-HIV-1 CD8(+) T cells that correlated with decreases in HIV-1 RNA and increases in T-cell counts. In the other patients, HIV-1-specific T-cell functions either failed to increase or declined from baseline during triple-drug therapy, even though some of these patients showed suppression of plasma HIV-1 RNA. These effects of combination therapy were not unique to HIV-1 specific T-cell responses, since similar effects were noted for CD8(+) T cells specific for the cytomegalovirus pp65 matrix protein. The level and breadth of CD8(+) cell reactivity to HLA A*02 HIV-1 epitopes, as determined by IFN-gamma production and HLA tetramer staining after combination therapy, were related to the corresponding responses prior to treatment. There was, however, a stable, residual population of potentially immunocompetent HIV-1-specific T cells remaining after therapy, as shown by tetramer staining of CD8(+) CD45RO(+) cells. These results indicate that new strategies will be needed to target residual, immunocompetent HIV-1-specific CD8(+) T cells to enhance the effectiveness of antiretroviral therapy in patients with advanced immunodeficiency.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV-1/imunologia , Adulto , Contagem de Linfócito CD4 , Linhagem da Célula , Quimioterapia Combinada , Produtos do Gene gag/imunologia , Produtos do Gene pol/imunologia , Infecções por HIV/fisiopatologia , Infecções por HIV/virologia , Inibidores da Protease de HIV/uso terapêutico , HIV-1/efeitos dos fármacos , Humanos , Indinavir/uso terapêutico , Interferon gama/biossíntese , Lamivudina/uso terapêutico , Estudos Longitudinais , Ativação Linfocitária , Peptídeos/imunologia , Fenótipo , Fosfoproteínas/imunologia , Inibidores da Transcriptase Reversa/uso terapêutico , Linfócitos T Citotóxicos/imunologia , Carga Viral , Proteínas da Matriz Viral/imunologia , Zidovudina/uso terapêutico
3.
J Infect Dis ; 179(2): 329-36, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9878015

RESUMO

CD4 T cell responses were studied for >2 years in 27 zidovudine-experienced patients with advanced human immunodeficiency virus type 1 (HIV-1) infection who received triple combination drug therapy with indinavir, zidovudine and lamivudine or zidovudine plus lamivudine or zidovudine alone for 24-42 weeks before switching to the three-drug therapy. Subjects initially given the three drugs had viremia suppressed to undetectable levels and increases in T cell proliferative and cytokine responses to microbial antigens through 2 years of follow-up. Patients receiving the triple-drug therapy after either indinavir or zidovudine-lamivudine treatment had similar increases in T cell responses only if they also had suppression of virus load. CD4 T cell reactivity to HIV-1 antigens was not restored. Prolonged indinavir-zidovudine-lamivudine treatment has significant but incomplete enhancing effects on CD4 T cell reactivity, which could be important in host control of microbial and persistent HIV-1 infections.


Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Fármacos Anti-HIV/uso terapêutico , Antígenos de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos HIV/imunologia , HIV-1 , Viremia/imunologia , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Adulto , Linfócitos T CD4-Positivos/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Quimiocinas/biossíntese , Citocinas/biossíntese , Método Duplo-Cego , Feminino , HIV-1/efeitos dos fármacos , HIV-1/imunologia , Humanos , Indinavir/uso terapêutico , Lamivudina/uso terapêutico , Masculino , Mitógenos/imunologia , RNA Viral/metabolismo , Viremia/tratamento farmacológico , Zidovudina/uso terapêutico
4.
Antimicrob Agents Chemother ; 40(12): 2842-7, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9124852

RESUMO

5-Chloro-2',3'-dideoxy-3'-fluorouridine (935U83) is a nucleoside analog reverse transcriptase inhibitor that has demonstrated selective anti-human immunodeficiency virus (HIV) activity in vitro and favorable safety profiles in monkeys and mice. A phase I study was conducted to evaluate the safety and pharmacokinetics of six escalating single oral doses of 935U83 in 12 HIV-infected adults. The effect of a high-fat meal on the oral bioavailability of 935U83 was also assessed. The volunteers enrolled had CD4+ cell counts ranging from < 50 to 753 cells per mm3 (median, 198). In the dose range of 100 to 1,500 mg 935U83 was well tolerated by all subjects with no drug-related adverse events reported. No significant clinical or laboratory abnormalities were observed throughout the study. 935U83 was rapidly and well absorbed following oral administration with peak plasma concentrations (Cmax) occurring at 0.8 to 1.3 h postdosing. Mean Cmax and AUC0-infinity values of 935U83 were nearly dose proportional in the 100- to 1,500-mg dose range (from 2.4 to 30 micrograms/ml and from 3.4 to 59 h.micrograms/ml, respectively). Elimination of 935U83 from the plasma was rapid, with an apparent half-life of 1.3 to 1.7 h which was independent of the dose level. Administration of 935U83 with a high-fat meal decreased the rate of 935U83 absorption (mean Cmax decreased by approximately 50% and mean time to Cmax increased by approximately 1 h) but did not affect the extent of oral bioavailability (AUC0-infinity) of 935U83. The 5'-O-glucuronide conjugate was the principal metabolite of 935U83 and was present in the plasma of all volunteers at concentrations lower than 935U83. The molar AUC0-infinity ratio (935U83 glucuronide to the parent compound) was similar across all dose levels (mean, 21 to 27%). At least 60% of the 935U83 dose was absorbed, and approximately an equal percentage of the dose (approximately 30%) was excreted as unchanged 935U83 and as 935U83 glucuronide. Systemic exposure to 935U83 at levels exceeding its average in vitro antiretroviral 50% inhibitory concentration (approximately 0.5 microgram/ml or 1.8 microM) can be achieved after a single oral dose.


Assuntos
Antivirais/farmacocinética , Didesoxinucleosídeos/farmacocinética , Infecções por HIV/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Didesoxinucleosídeos/administração & dosagem , Didesoxinucleosídeos/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Infecções por HIV/sangue , Infecções por HIV/urina , Humanos , Masculino , Pessoa de Meia-Idade
5.
Proc Natl Acad Sci U S A ; 92(2): 397-401, 1995 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-7831298

RESUMO

Currently, therapeutic platelet concentrates can be stored for only 5 days. We have developed a procedure that permits long-term storage of fixed and lyophilized platelets that retain hemostatic properties after rehydration. These rehydrated lyophilized platelets (RL platelets) restore hemostasis in thrombocytopenic rats and become incorporated in the hemostatic plug of bleeding time wounds of normal dogs as well as von Willebrand disease dogs with partially replenished plasma von Willebrand factor. Ultrastructurally, these platelets are well preserved and are comparable to control normal washed platelets. Flow cytometry analysis shows that RL platelets react with antibodies to the major surface receptors, glycoprotein (GP)Ib and GPIIb/IIIa. These receptors are involved in platelet agglutination, aggregation, and adhesion. In vitro functional tests document the ability of RL platelets to adhere to denuded subendothelium and to spread on a foreign surface. Circulating RL platelets participated in carotid arterial thrombus formation induced in normal canine subjects. The participation of RL platelets in these vital hemostatic properties suggests that with further development they could become a stable platelet product for transfusion.


Assuntos
Plaquetas , Preservação de Sangue/métodos , Hemostáticos , Transfusão de Plaquetas , Animais , Tempo de Sangramento , Plaquetas/fisiologia , Plaquetas/ultraestrutura , Cães , Orelha/lesões , Liofilização , Humanos , Glicoproteínas da Membrana de Plaquetas/análise , Ratos , Ratos Sprague-Dawley , Trombocitopenia/terapia , Fixação de Tecidos , Ferimentos e Lesões/terapia , Doenças de von Willebrand/terapia
6.
Am J Physiol ; 266(6 Pt 1): C1795-802, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8023908

RESUMO

We examined the myofibril biochemical, structural, and biophysical properties of C2C12, a mouse skeletal muscle cell line (American Type Culture Collection), to assess whether force development and the sensitivity of the myofilaments to calcium could be measured in C2C12 myotubes and whether a cardiac contractile protein, troponin T, is expressed and incorporated into C2C12 myofibrils. When myoblasts fused and differentiated into myotubes, expression of myofilament proteins was initiated. Multiple cardiac and skeletal muscle troponin T isoforms were coexpressed. Cardiac troponin T expression increased and then decreased with time. Fluorescence immunocytochemistry demonstrated incorporation of cardiac troponin T isoforms into the myofibrils. At the time of the biophysical studies, mean myotube diameter was 12 microns (range 5-25 microns), and mean length was 290 microns (range 130-520 microns). The estimated maximum force developed by chemically skinned myotubes at 6-7 days poststarvation, 0.88 +/- 0.12 microN (mean +/- 95% confidence interval, n = 5), was significantly less (P < 0.05) than that at 10-13 days poststarvation, 1.12 +/- 0.12 microN (n = 7). The force-pCa relation yielded a Hill coefficient of 2.9 +/- 0.6 (n = 7) and half-maximal activation at pCa of 5.77 +/- 0.20. The demonstration that the biophysical properties of C2C12 cells can be measured and that cardiac and skeletal muscle troponin T isoforms are incorporated and colocalized into myofibrils suggest that these cells could be a useful model to assess the effects of exogenous native and mutated cardiac and skeletal contractile protein isoforms on myofilament function.


Assuntos
Linhagem Celular/metabolismo , Linhagem Celular/fisiologia , Músculos/metabolismo , Músculos/fisiologia , Citoesqueleto de Actina/metabolismo , Animais , Cálcio/metabolismo , Cálcio/farmacologia , Linhagem Celular/ultraestrutura , Complacência (Medida de Distensibilidade) , Meios de Cultura , Imuno-Histoquímica , Isomerismo , Camundongos , Contração Muscular , Proteínas Musculares/metabolismo , Músculos/ultraestrutura , Miocárdio/metabolismo , Troponina/metabolismo , Troponina T
7.
AIDS ; 8(1): 59-66, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8011237

RESUMO

OBJECTIVE: A Phase I study of subcutaneous recombinant interleukin-2 (rIL-2). DESIGN: Sixteen patients with advanced HIV infection receiving 600-1200 mg zidovudine per day were divided into three groups, which received sequentially 0.2 x 10(6), 0.7 x 10(6) or 2 x 10(6) units/m2 per day of rIL-2 subcutaneously 5 consecutive days. SETTING: Five-day admission to an academic tertiary care hospital. PATIENTS, PARTICIPANTS: Sixteen unblinded, non-randomized volunteers. INTERVENTIONS: Subcutaneous rIL-2. MAIN OUTCOME MEASURES: Tolerance, toxicity, hematologic, immunologic and antiviral responses. RESULTS: rIL-2 was well-tolerated at the highest dosage, except in two patients who developed significant lymphopenia by the second day of rIL-2 administration, with rebound within 48 h after rIL-2 therapy. The number of eosinophils, CD4+ and CD8+ cells, and percentage of CD16+ (natural killer) cells, remained elevated above baseline for up to 10 weeks. Circulating rIL-2 receptor levels increased transiently during and immediately following rIL-2 administration. A twofold increase in natural killer cell activity against uninfected and HIV-infected targets was observed, but did not persist beyond 10 weeks following rIL-2 administration. There was a transient decrease in blastogenesis to phytohemagglutinin of patients receiving the highest dose of r-IL-2, but no significant change in viral burden. CONCLUSIONS: Subcutaneous rIL-2 in advanced HIV-infected patients on zidovudine was tolerated with side-effects similar to intravenous IL-2.


Assuntos
Infecções por HIV/tratamento farmacológico , Interleucina-2/uso terapêutico , Zidovudina/uso terapêutico , Adulto , Quimioterapia Combinada , Infecções por HIV/microbiologia , Humanos , Injeções Subcutâneas , Interleucina-2/administração & dosagem , Interleucina-2/efeitos adversos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Leucócitos/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de Interleucina-2/análise , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico
8.
Neuron ; 8(5): 899-906, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1316766

RESUMO

Evidence is presented that two isoforms of the voltage-dependent, dihydropyridine-sensitive calcium channel alpha 1 subunit are present in newborn and adult skeletal muscle and that expression of these isoforms is developmentally regulated. A voltage-dependent calcium channel alpha 1 cDNA from newborn muscle was cloned and found to be identical to that published from the adult, except that it was 2 kb shorter owing to an internal deletion. Nucleotide sequences, Northern blots, reverse-transcriptase PCR experiments, and sequencing of the PCR product confirmed that a segment corresponding to the inner two repeats of the structural prototype four homologous motifs is missing from the immature isoform. Immunological studies using antisera raised against synthetic peptides that correspond to sequences in the two isoforms show that the abbreviated transcript is predominant in newborn muscle, whereas the four-repeat isoform is the major species in the adult.


Assuntos
Canais de Cálcio/química , Músculos/química , Envelhecimento/metabolismo , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Sequência de Bases , Northern Blotting , Southern Blotting , Western Blotting , Canais de Cálcio/genética , Clonagem Molecular , DNA/química , DNA/genética , Substâncias Macromoleculares , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Desenvolvimento Muscular , Reação em Cadeia da Polimerase , Coelhos , Sequências Repetitivas de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico
9.
AIDS ; 5(5): 491-6, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1863401

RESUMO

Zidovudine therapy of AIDS patients has been shown to cause only transient improvements in the numbers of circulating CD4+ cells and the in vitro functional activities of cultured lymphocytes. The present studies were undertaken to determine whether prolonged zidovudine therapy enhanced reactivity in two sensitive assays of T-cell function: the ability of phytohemagglutinin (PHA)-stimulated cells to form T-cell colonies and their capacity to express receptors for the growth factor interleukin-2 (IL-2). Treated patients, studied over periods of 20-60 weeks, showed no improvement in colony formation at any time interval, even in plates supplemented with exogenous IL-2. However, mitogen-stimulated T lymphocytes showed a significant increase in the capacity to express IL-2 receptors (CD25). This enhanced expression resulted primarily from activation of the CD8+ cell subset.


Assuntos
Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Receptores de Interleucina-2/biossíntese , Subpopulações de Linfócitos T/efeitos dos fármacos , Zidovudina/uso terapêutico , Síndrome da Imunodeficiência Adquirida/imunologia , Ensaio de Unidades Formadoras de Colônias , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , Humanos , Ativação Linfocitária/efeitos dos fármacos , Masculino , Fito-Hemaglutininas/farmacologia , Receptores de Interleucina-2/análise , Receptores de Interleucina-2/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia
10.
Am J Med ; 89(3): 275-81, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2203260

RESUMO

PURPOSE: To heighten awareness of the role of Mycoplasma hominis as an extragenital pathogen in adults. PATIENTS AND METHODS AND RESULTS: Patients ranged in age from 14 to 76 years. Thirteen patients were immunosuppressed, including nine organ transplant recipients; three were receiving steroids, and two had an underlying malignancy. The remainder were immunocompetent. Thirteen patients had prior surgery at or near the site of infection. M. hominis was isolated from normally sterile sites such as blood or cerebrospinal, pleural, abdominal and joint fluids, and bone. Non-sterile sites of isolation included surgical wounds and pulmonary secretions. The organism was detected in anaerobic cultures of clinical specimens sent to the laboratory for routine bacteriologic culture. Gram stains of fluids or wound drainage revealed neutrophils but no bacteria. Anti-mycoplasmal therapy was effective in eradicating the organism in 13 of 15 patients who were treated. Of those in whom treatment failed, one patient had an antibiotic-resistant isolate and the other had M. hominis isolated from the lung at postmortem after just 2 days of therapy. CONCLUSION: Our experience suggests that significant infections due to M. hominis, although uncommon, are not rare, and methods to isolate and identify this organism should be available for general adult medical and surgical populations.


Assuntos
Infecções por Mycobacterium/epidemiologia , Adolescente , Adulto , Idoso , Técnicas Bacteriológicas , Clindamicina/uso terapêutico , Doxiciclina/uso terapêutico , Feminino , Humanos , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Mycobacterium/isolamento & purificação , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/patologia , Pennsylvania/epidemiologia , Estudos Retrospectivos , Procedimentos Cirúrgicos Operatórios , Infecção da Ferida Cirúrgica/microbiologia , Ventriculostomia/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA