Assuntos
Antígenos CD/metabolismo , Antígeno B7-1/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Interferon-alfa/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Glicoproteínas de Membrana/metabolismo , Apresentação de Antígeno , Antígenos CD/análise , Antígeno B7-2 , Células Dendríticas/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Imunidade Celular , Interferon alfa-2 , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Proteínas RecombinantesRESUMO
In this study we evaluated whether a good response to conventional chemotherapy, i.e. a significant tumour reduction, is a prerequisite for improved survival in multiple myeloma (MM). Between January 1987 and March 1990, 341 consecutive previously untreated patients with MM received chemotherapy within the prospective, multicentre, randomised Protocol MM87. Of these, 258 patients were evaluable for both response and long-term survival and 244 (94.6%) have died. The median survival of all patients was 40 months (6-162 months). The median survival did not differ between patients who had complete response (CR) (50 months (9-162 months)), partial response (PR) (46 months (8-147 months)) or stable disease (SD) (41 months (7-135 months)). The median survival was shorter (13.6 months (6-135 months)) (P<0.0001) in patients whose disease progressed while they were receiving first induction chemotherapy. Causes of death were more frequently (P=0.04) related to MM in patients who had progressive disease (PD) than in patients who had a CR or PR or SD. The main clinical and laboratory characteristics were similar in the four groups. These data indicate that patients who maintain SD during first-line chemotherapy have a prognosis similar to that of patients who attain a response. Only patients whose disease progresses have a distinctly worse outcome.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Análise de Variância , Causas de Morte , Avaliação de Medicamentos , Feminino , Humanos , Masculino , Melfalan/administração & dosagem , Peptiquímio/administração & dosagem , Prednisona/administração & dosagem , Estudos Prospectivos , Design de Software , Análise de Sobrevida , Vincristina/administração & dosagemRESUMO
Experiments were designed to demonstrate the actual contribution of yeast in the formation of the primary aroma during the vinification of neutral grapes. Ruché was chosen as the model wine to study because of its unique fragrance. A yeast strain specific for Ruché was selected using a new and rapid isolation method for red wines. The results of this study can be summarized as follows: Skins from nonaromatic white or red grapes apparently contain most of the primary aroma compounds that are revealed in the must only after contact with yeast cells under defined conditions. Similar results were obtained with the pulp and seeds fractions; however, the olfactory notes, although well characterized, differed from those obtained with skins alone. Clarification, filtration, and centrifugation of the pulp and seed fractions or sonification of the skins produce different and well-characterized olfaction notes during the contact with yeast. The primary aroma of nonaromatic white and red grapes contained in the skins can be revealed within 24-48 h of yeast contact in a synthetic nutrient medium (SNM). The primary aroma precursors extracted from the skins with methanol, water-saturated butanol, or aqueous buffer at pH 3.2, concentrated and eluted from a C18 resin column, can be transformed to the free form wine aroma markers within 6 h of contact with yeast cells in SNM. By contrast, prolonged maceration of the skins in aqueous alcoholic buffer at pH 3.2 or 1.1, at 50 or 70 degrees C did not release primary odors typical of wine. The individual primary aroma compounds, identified by GC-MS analysis in Ruché wine samples or in Ruché skin-yeast-SNM samples, could not explain the complexity of the typical Ruché wine odor. Only odors common to many wine varieties were identified by GC-olfactometry analysis.
Assuntos
Frutas/metabolismo , Odorantes , Saccharomyces cerevisiae/fisiologia , Volatilização , VinhoRESUMO
In this study, a double labeling technique using retrograde tracing with protein-gold complex (gold-HRP) in conjunction with a gammaamino-butyric acid (GABA) and glutamate immunohistochemical procedure was performed to identify GABA (GABA-IR) and glutamate (Glu-IR) immunoreactive neurons in the cerebellar fastigial nucleus (FN) that projects to the vestibular nuclei (VN). The results show that FN neurons projecting to the VN consist of both GABA-IR and Glu-IR neurons with a predominance of glutamatergic ones. Because GABAergic neurons in the cerebellar nuclei project to the inferior olive (IO), double retrograde labeling experiments were performed with injections of gold-HRP in the IO and of biotilynated dextran amine in the VN. This showed that the GABA-IR fastigiovestibular neurons project by axon collaterals to both the VN and the IO.
Assuntos
Núcleos Cerebelares/metabolismo , Vias Neurais/metabolismo , Neurônios/metabolismo , Ratos Sprague-Dawley/metabolismo , Núcleos Vestibulares/metabolismo , Animais , Transporte Axonal/efeitos dos fármacos , Transporte Axonal/fisiologia , Contagem de Células , Tamanho Celular/fisiologia , Núcleos Cerebelares/citologia , Ácido Glutâmico/metabolismo , Compostos de Ouro/farmacocinética , Peroxidase do Rábano Silvestre/farmacocinética , Imuno-Histoquímica , Vias Neurais/citologia , Neurônios/citologia , Ratos , Ratos Sprague-Dawley/anatomia & histologia , Núcleos Vestibulares/citologia , Ácido gama-Aminobutírico/metabolismoAssuntos
Antineoplásicos/imunologia , Imunidade Celular , Interferon-alfa/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Adulto , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Imunidade Celular/efeitos dos fármacos , Interferon-alfa/farmacologia , Interferon-alfa/uso terapêutico , Pessoa de Meia-Idade , Linfócitos T Citotóxicos/imunologiaRESUMO
The dentatovestibular connections were investigated using anterograde and retrograde tracing methods. All parts of the cerebellar nucleus lateralis (NL) or dentate nucleus sent fibers onto the ipsilateral vestibular nuclear complex. In spite of their apparently widespread area of termination, dentatovestibular fibers were distributed differentially, according to the subregion of the NL they arose from. Fibers from the main, magnocellular region and the dorsolateral hump (dlh) reached the four main vestibular nuclei, but preferentially the superior (SV) and inferior (IV) vestibular nuclei. The projections to the lateral and the medial vestibular nuclei, which were less abundant, essentially originated from neurons located in the dlh. Fibers arising from the parvocellular subregion of Flood and Jansen terminated within the SV and IV only. Some rare reciprocal vestibulodentate projections were observed. These observations suggest highly integrated activities of dentatovestibular connections related to postural, but also vestibulo-oculomotor functions.
Assuntos
Biotina/análogos & derivados , Núcleos Cerebelares/anatomia & histologia , Núcleos Vestibulares/anatomia & histologia , Animais , Núcleos Cerebelares/citologia , Dextranos , Corantes Fluorescentes , Histocitoquímica , Peroxidase do Rábano Silvestre , Fibras Nervosas/fisiologia , Vias Neurais/anatomia & histologia , Vias Neurais/citologia , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Núcleos Vestibulares/citologiaRESUMO
We conducted a randomized trial to evaluate whether melphalan-prednisone (MPH-P) treatment administered just after diagnosis improves survival of stage I multiple myeloma (MM). Between January 1987 and March 1993, 145 consecutive previously untreated patients with stage I MM were randomized between treatment with MPH-P (administered for 4 days every 6 weeks) just after diagnosis and treatment only at disease progression. Survival was not influenced by MPH-P treatment either administered just after diagnosis or at disease progression (64 vs 71 months respectively). Comparing the first with the second group the odds ratio of death is 1.17 (95% confidence interval 0.57-2.42; P = 0.64). Disease progression occurred within a year in about 50% of patients who were initially untreated. Response rate was similar in both groups, but duration of response was shorter in patients who were treated at disease progression (48 vs 79 months, P = 0.044). Patients actually treated at disease progression (34/70) survived shorter than those who had neither disease progression nor treatment (56 vs > 92 months; P = 0.005). Starting MPH-P just after diagnosis does not improve survival and response rate in stage I MM, with respect to deferring therapy until disease progression. However, patients with stage I MM randomized to have treatment delayed and who actually progressed and were treated had shorter survival than those with stable disease and no treatment. Biologic or other disease features could identify these subgroups of patients.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Masculino , Melfalan/administração & dosagem , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Prednisona/administração & dosagem , Prognóstico , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
In order to study the connection patterns between the sensory trigeminal and the vestibular nuclei (VN), injections of anterogradely and/or retrogradely transported neuronal tracers were made in the rat. Trigeminal injections resulted in anterogradely labelled fibres, with an ipsilateral preponderance, within the VN: in the ventrolateral part of the inferior nucleus (IVN), in the lateral part of the medial nucleus (MVN), in the lateral nucleus (LVN) with a higher density in its ventral half, and in the superior nucleus (SVN), more in the periphery than in the central part. Moderate trigeminal projections were observed in the small vestibular groups f, x and y/l and in the nucleus prepositus hypoglossi. Additional retrogradely labelled neurones were seen in the IVN, MVN, and LVN, in the same regions as those receiving trigeminal afferents. Morphological analysis of vestibular neurones demonstrated that vestibulo-trigeminal neurones are relatively small and belong to a different population than those receiving projections from the trigeminal nuclei. The trigeminovestibular and vestibulo-trigeminal relationships were confirmed by tracer injections in the VN. The results show that, in the VN, there is sensory information from facial receptors in addition to those reported from the neck and body. These facial afferents complement those from the neck and lower spinal levels in supplying important somatosensory information from the face and eye muscles. The oculomotor connections of the respective zones of the VN receiving trigeminal afferents suggest that sensory inputs from the face, including extraocular proprioception, may, through this pathway, influence the vestibular control of eye and head movements.
Assuntos
Ratos/fisiologia , Núcleos do Trigêmeo/fisiologia , Núcleos Vestibulares/fisiologia , Animais , Nervo Hipoglosso/fisiologia , Eminência Mediana/fisiologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Ratos Sprague-Dawley , Núcleos Vestibulares/citologiaRESUMO
The efficacy of alfa-interferon (alfa-IFN) in essential thrombocythemia (ET) patients has been reported by several authors. The aim of this study is to assess the magnitude of the effect of alfa-IFN on the neoplastic clone. As of December 1993, 11 ET patients received alfa-IFN at a dose of 3-6 MU/s.c./day for 6 months. Ten of 11 obtained complete hematological remission (CHR) and one achieved partial hematological remission. Megakaryocyte concentration was reduced in six cases. The spleen,which was enlarged in four patients, decreased in size in two patients. Seven of eight patients who were symptomatic at diagnosis obtained resolution of symptoms. In order to obtain indications about the structural modifications induced by alfa-IFN in ET megakaryocytes (Mks), Fourier-transform infra-red microspectroscopy analysis performed on 10 single Mks of each patient, was done in seven of 11 patients; the analysis showed a reduction of A1/A2 ratios (A1 integrated area of the band at 1080 cm(-1) due to the nucleic acids absorption; A2 integrated area of the band at 1540 cm(-1) due to proteic components absorption) in five cases, and in three of these five patients A1/A2 ratios achieved normal values. After alfa-IFN treatment we did not observe any change in the methylation pattern of DNA from the granulocyte fraction. Our results confirm the efficacy of alfa-IFN in ET patients, and the decrease of A1/A2 ratios in several patients is a demonstration of the depth of the effect of alfa-IFN on the neoplastic clone. The results of clonality studies showed the persistence of clonal hematopoiesis. Whether higher alfa-IFN dose and/or more prolonged alfa-IFN therapy may allow a restoration of polyclonal hematopoiesis remains to be determined and should be explored in future clinical trials.
Assuntos
Interferon-alfa/uso terapêutico , Trombocitose/terapia , Adolescente , Adulto , Análise de Variância , DNA/sangue , Hematopoese , Células-Tronco Hematopoéticas/patologia , Heterozigoto , Humanos , Interferon-alfa/efeitos adversos , Contagem de Leucócitos , Megacariócitos/efeitos dos fármacos , Megacariócitos/patologia , Pessoa de Meia-Idade , Fosfoglicerato Quinase/genética , Contagem de Plaquetas , Polimorfismo de Fragmento de Restrição , Esplenomegalia/terapia , Trombocitose/sangue , Cromossomo XRESUMO
Age could influence the prognosis of multiple myeloma patients treated with conventional chemotherapy. Between January 1987 and March 1990, 341 consecutive previously untreated patients with multiple myeloma received chemotherapy within the prospective, multicentre, randomized Protocol MM87. Survival was evaluated in patients aged > or < or = 66 years (the median age for the whole series) and in a subgroup of patients aged < 55 years. These groups were similar for main clinical characteristics, including results of cytostatic treatment. As of May 1996, 271 (79%) of the 341 patients had died, and median follow-up of the 70 (21%) living patients was 82 months. Overall, younger patients survived longer than older ones. In fact, in patients > and < or = 66 years, median survival was 31 and 44 months (P < 0.00095) and the percentage of patients surviving over 72 months was 17% and 32% (P = 0.0018) respectively; in patients < 55 years, these figures were 57 months and 35% respectively (P = 0.02 and 0.01, with respect to patients aged > 55 years). In all groups, about 50% of the patients surviving over 72 months had stage I disease. For multiple myeloma patients treated with chemotherapy, survival is favourably affected by relatively young age and early stage of disease.
Assuntos
Mieloma Múltiplo/mortalidade , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Estudos Prospectivos , Taxa de SobrevidaRESUMO
Beta thalassemia is a hereditary anemia curable by bone marrow transplantation (BMT). Class 3 patients have a much worse outcome with a high incidence of rejection after BMT. Adhesion molecules, including the intercellular adhesion molecule 1 are thought to play an essential role in the rejection process. To investigate whether increased levels of soluble intercellular adhesion molecule 1 (sICAM-1) may be predictive of graft rejection, the pretransplant serum concentration of sICAM-1 of 27 beta thalassemic patients who rejected the graft was compared to that of 68 beta thalassemic patients who achieved a sustained engraftment. Fifty serum samples, obtained from marrow donors, matched for age and sex, served as controls. Beta thalassemic patients had significantly higher sICAM-1 concentrations as compared to controls (P = 0.0001). Significantly increased levels of sICAM-1 were found in the patients who subsequently rejected the graft (mean (95% CI) = 490 ng/ml (440; 540)) as compared to those with sustained engraftment (400 ng/ml (384; 415)), (P = 0.004). The mean level of sICAM-1 in patients with early rejection was significantly higher than that in patients with late rejection (P = 0.04). This may indicate a transfusion-mediated role of sICAM-1: some beta thalassemic patients with high sICAM-1 levels, induced by the transfusion support, may remain immunologically active, despite the conditioning regimen, therefore such patients are likely to have an early graft rejection. Our findings indicate that sICAM-1 could be a useful indicator of immune activation in polytransfused patients with beta thalassemia who have a high risk of rejection. Determination of sICAM-1 has potential clinical implications in predicting which patients may reject after BMT.
Assuntos
Transplante de Medula Óssea , Rejeição de Enxerto/sangue , Molécula 1 de Adesão Intercelular/sangue , Talassemia beta/terapia , Adolescente , Criança , Feminino , Humanos , Masculino , Fatores de Risco , Talassemia beta/sangueRESUMO
AIMS: The study was carried out to investigate the efficacy and toxicity of fludarabine phosphate in the treatment of B-cell chronic lymphocytic leukemia (B-CLL) in previously treated patients. METHODS: Sixteen patients, 11 males and 5 females, 9 in stage B and 7 in stage C, according to the Binet Staging System, were treated with a maximum of 6 cycles of fludarabine (25 mg/m2) for 5 days, every 4 weeks. All patients had been pretreated, 10 were refractory to standard regimens, 5 were in relapse, and 1 patient was in partial remission. RESULTS: Thirteen patients were judged suitable for evaluation. Overall 9 patients were responsive to treatment; 4 complete and 5 partial responses were observed. Of the 4 patients in complete remission, 3 were alive at 6, 10 and 13 months, respectively, from the beginning of treatment. One patient died after 11 months for acute graft-versus-host disease after allogenic bone marrow transplantation by an HLA sibling donor. Two of the 5 patients in partial remission were alive at 7 and 17 months, respectively, and the other 3 died (2 of disease reexpansion after 14 and 16 months and 1 of septic shock following pneumonia). Four patients were not responsive to treatment: 1 died from disease progression after 8 months from the beginning of therapy, 1 from cardiac failure after 9 months, 1 from septic shock following meningitis, and 1 was alive after 7 months of follow-up. Treatment was well tolerated, with nausea and vomiting in only one patient. We observed two episodes of pneumonitis, without any evidence of the responsible agent, a tumor lysis syndrome with acute renal failure, a recurrence of autoimmune thrombocytopenia, and a Coombs-positive hemolytic anemia. CONCLUSIONS: Fludarabine phosphate is effective in the treatment of patients with advanced B-CLL, even in those refractory to multiple chemotherapy regimens.
Assuntos
Antineoplásicos/uso terapêutico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Vidarabina/análogos & derivados , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Esquema de Medicação , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sobrevida , Resultado do Tratamento , Vidarabina/administração & dosagem , Vidarabina/efeitos adversos , Vidarabina/uso terapêuticoRESUMO
The HIV viral burden and RNA expression in a selected group of infected, clinically non-progressor patients were investigated. Five fast-progressor patients and 10 AIDS cases were included as controls. The HIV viral load was investigated by semiquantitative polymerase chain reaction (PCR) in adherent macrophages and in genomic and extragenomic fractions of lymphocytes. HIV DNA was not found in macrophages in the non-progressor subjects, was weakly positive in 2 of 5 fast-progressors and strongly positive in most of the AIDS patients. The number of HIV proviruses found in lymphocytes of the non-progressor subjects varied from 5 to 160 copies/microgram DNA, values ten times lower than those recorded in fast-progressors and AIDS patients. The extragenomic HIV DNA (2 LTR forms) was absent or barely detectable in the lymphocytes from non-progressors and abundant in the other groups. HIV RNA was not found in the lymphocytes of all non-progressors. This may indicate that a latent state of HIV provirus exists in the lymphocytes of these subjects. To investigate this point, cultivation and stimulation with PHA (phytohemoagglutinin) and PMA (phorbol 12-myristate 13-acetate) of lymphocytes from these subjects were attempted but after 6 days HIV RNA (RT-PCR for gag region) was still absent or barely detectable in these patients. There are no other reports of the absence of HIV provirus induction in lymphocytes from infected individuals. If confirmed in a larger number of patients, such non-inducibility might serve as a predictor marker of progression of the disease.
Assuntos
Infecções por HIV/virologia , HIV/fisiologia , Linfócitos/virologia , Macrófagos/virologia , Provírus/fisiologia , Latência Viral , Síndrome da Imunodeficiência Adquirida/virologia , Estudos de Coortes , DNA Viral/sangue , Progressão da Doença , Seguimentos , Produtos do Gene gag/genética , HIV/isolamento & purificação , Soropositividade para HIV , Humanos , Linfócitos/efeitos dos fármacos , Fito-Hemaglutininas/farmacologia , Reação em Cadeia da Polimerase , Provírus/isolamento & purificação , RNA Viral/sangue , Acetato de Tetradecanoilforbol/farmacologia , Ativação ViralRESUMO
This study analyzes the serum transferrin receptor (sTfR) levels in a series of 230 ex-thalassemics with a follow-up of 1 to 9 years after bone marrow transplantation (BMT) for homozygous beta thalassemia. Ex-thalassemics are individuals, cured of homozygous beta thalassemia by BMT, who maintain different degrees of iron overload acquired during the pretransplant period. Both in experimental and clinical conditions, sTfR concentrations have been shown to be a quantitative measure of body iron status. This study was carried out to assess whether the level of sTfR may be of help in determining the extent of iron overload in ex-thalassemics. Patients who received the marrow from their HLA-identical sibling donor heterozygous for beta thalassemia, namely heterozygous ex-thalassemics, displayed significantly higher levels of sTfR than patients transplanted from their normal sibling donors (normal ex-thalassemics). This finding suggests that increased erythropoiesis, albeit in part ineffective in heterozygous ex-thalassemics, is responsible for the sTfR increment. Both heterozygous and normal ex-thalassemics had significant lower sTfR levels than their heterozygous (p < 0.003) or normal (p < 0.0001) donors, respectively. These differences may be ascribed to the presence of iron overload in ex-thalassemics in comparison to their normal or heterozygous donors who did not present excess of iron in the body. A significant inverse correlation between sTfR and serum ferritin levels (r = -0.54, p < 0.0001) was found when normal ex-thalassemics were considered. In heterozygous ex-thalassemics, the lack of correlation between these two parameters may be explained by the enhanced erythropoietic activity of individuals with thalassemic trait. These results suggest that the level of sTfR may be a useful indicator of iron overload in normal ex-thalassemics.
Assuntos
Transplante de Medula Óssea , Ferritinas/metabolismo , Receptores da Transferrina/metabolismo , Talassemia beta/sangue , Talassemia beta/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Heterozigoto , Humanos , MasculinoRESUMO
Despite their primitive place in the classification of fishes, Osteoglossids have a high level of encephalization, which can be analyzed by studying their brain organization. The quantitative analysis of their main brain parts shows small relative volumes of the olfactory bulbs, normal importance of the optic tectum (linked to vision) and of the cerebellum (linked to motor abilities). The medulla oblongata shows very large gustatory lobes in Heterotis, due to the special microphagous mode of feeding of this species. The cerebral hemispheres are larger in Arapaima than in other osteoglossids, but the lack of data on the comparative behaviour of these fishes does not allow us to give a reliable explantation of this peculiarity.
Assuntos
Encéfalo/anatomia & histologia , Animais , Peso Corporal , Encéfalo/fisiologia , Cerebelo/fisiologia , Peixes , Bulbo/fisiologia , Bulbo Olfatório/fisiologiaRESUMO
This study analyzes the serum transferrin receptor (sTfR) levels in a series of 184 ex-thalassemic patients with a follow-up of 1 to 9 years after bone marrow transplantation (BMT) for homozygous beta thalassemia. A significant inverse correlation between sTfR and Hb levels was observed (r = -0.36, p < 0.001). Patients who received the marrow from an HLA-identical sibling donor heterozygous for beta thalassemia displayed significantly higher levels of sTfR than patients transplanted from a normal sibling donor (p < 0.001). A cut-off value of 2600 ng/mL of sTfR was established. Only 3 out of 56 (5%) patients who received the marrow from a normal sibling, reached a sTfR value above the cut-off level, while 64 out of 128 (50%) patients transplanted from a heterozygous sibling donor showed sTfR values > 2600 ng/mL (p < 0.001). These results suggest that the level of sTfR helps to identify ex-thalassemic patients with enhanced or normal erythropoietic activity among those transplanted from HLA-identical sibling donors heterozygous for beta thalassemia. The physiologic and clinical significance of different patterns of sTfR levels in ex-thalassemic patients with beta thalassemia trait deserves to be investigated.
Assuntos
Transplante de Medula Óssea , Heterozigoto , Receptores da Transferrina/metabolismo , Doadores de Tecidos , Talassemia beta/terapia , Seguimentos , Humanos , Solubilidade , Talassemia beta/genética , Talassemia beta/metabolismoRESUMO
Compared with other T cell lines, C8166 lymphocytes are particularly susceptible to human immunodeficiency virus (HIV) infection and the outcome is invariably cell death. The results reported in this study demonstrate that the virus-induced cytolysis is strongly dependent on the initial cell density of C8166 cultures. Cultures diluted to 50 to 500 cells/ml almost completely maintained their cell duplication rate and released infectious virus into the medium. HIV infection of diluted C8166 cells is a simple and easily reproducible procedure for obtaining persistently infected cultures. These cultures contained genomic and extragenomic HIV DNA, the latter being assayed by PCR for two-long terminal repeat circular forms. The status of persistent infection disappeared within 2 months. The recovery is due to the replacement of CD4 down-regulated infected cells by overgrowing uninfected cell variants, which are transcriptionally inactive for CD4. The mechanisms underlying the emergence of these variants in persistently infected cultures are considered.
Assuntos
Antígenos CD4/biossíntese , Regulação para Baixo , HIV-1/crescimento & desenvolvimento , Linfócitos T/microbiologia , Divisão Celular , Linhagem Celular , Sobrevivência Celular , DNA Viral , HIV-1/genética , HIV-1/imunologia , Humanos , Linfócitos T/imunologia , Integração ViralRESUMO
Several reports show that the prevalence of HBV (hepatitis B virus) carriers in HIV (human immunodeficiency virus) infected populations is significantly higher than in HIV seronegative individuals, independent of the risk group for HIV, that is, homosexuals or drug abusers. In this context, evaluation of the simultaneous presence of HBV and HIV in PBMCs (peripheral blood mononuclear cells) is of particular interest for at least 2 reasons: 1) the possible reciprocal influence of the 2 viruses when they infect the same cell; 2) the possibility that HIV-induced hematological disorders could indirectly influence the settling of HBV in blood cell populations. We report data on the frequency of PCR positivity for HBV DNA in PBMCs from 62 HIV infected patients, rigorously selected by risk group, that is, intravenous use of heroin for at least 3 years and syringe promiscuity. Sixty-seven HIV negative individuals who never used any drug formed the control group. The analysis of the cases positive for HBV DNA in PBMCs showed that: 1) the overall prevalence of PCR positivity found in HIV infected patients was significantly lower than that registered in the control group; 2) PCR positivity among the subjects who were HBsAg negative and anti-HBV positive was extremely low in the HIV infected patients (3.7%) but quite frequent in the HIV negative subjects (37.0%). The results support the hypothesis that, unlike the HIV negative individuals, our HIV infected patients exhibited HBV DNA in PBMCS almost exclusively when they presented with active HBV replication.