RESUMO
Acute cellular rejection occurs frequently during the first few weeks following liver transplantation. During this period, its molecular phenotype is confounded by peri- and postoperative proinflammatory events. To unambiguously define the molecular profile associated with rejection, we collected sequential biological specimens from 55 patients at least 3 years after liver transplantation who developed rejection during trials of intentional immunosuppression withdrawal. We analyzed liver tissue and blood samples obtained before initiation of drug withdrawal and at rejection, alongside blood samples collected during the weaning process. Gene expression profiling was conducted using whole-genome microarrays and real-time polymerase chain reaction. Rejection resulted in distinct blood and liver tissue transcriptional changes in patients who were either positive or negative for hepatitis C virus (HCV). Gene expression changes were mostly independent from pharmacological immunosuppression, and their magnitude correlated with severity of histological damage. Differential expression of a subset of genes overlapped across all conditions. These were used to define a blood predictive model that accurately identified rejection in HCV-negative, but not HCV-positive, patients. Changes were detectable 1-2 mo before rejection was diagnosed. Our results provide insight into the molecular processes underlying acute cellular rejection in liver transplantation and help clarify the potential utility and limitations of transcriptional biomarkers in this setting.
Assuntos
Biomarcadores/metabolismo , Perfilação da Expressão Gênica , Rejeição de Enxerto/diagnóstico , Tolerância Imunológica/genética , Transplante de Fígado , Complicações Pós-Operatórias , Suspensão de Tratamento , Feminino , Seguimentos , Regulação da Expressão Gênica , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/metabolismo , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão , Imunossupressores/uso terapêutico , Hepatopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
We report the results of a prospective randomized controlled trial in liver transplantation assessing the efficacy and safety of antithymocyte globulin (ATG-Fresenius) plus tacrolimus monotherapy at gradually decreasing doses. Patients were randomized to either: (a) standard-dose tacrolimus plus steroids;or (b) peritransplant ATG-Fresenius plus reduced-dose tacrolimus monotherapy followed by weaning of tacrolimus starting 3 months after transplantation. The primary end-point was the achievement of very low-dose tacrolimus (every-other-day or once daily dose with <5 ng/mL trough levels) at 12 months after transplantation. Acute rejection occurring during the first 3 months after transplantation was more frequent in the ATG group (52.4% vs. 25%). Moreover, late acute rejection episodes occurred in all recipients in whom weaning was attempted and no recipients reached the primary end-point. This motivated the premature termination of the trial. Tacrolimus trough levels were lower in the ATG-Fresenius group but no benefits in terms of improved renal function, lower metabolic complications or increased prevalence of tolerance-related biomarkers were observed. In conclusion, the use of ATG-Fresenius and tacrolimus at gradually decreasing doses was associated with a high rate of rejection, did not allow for the administration of very low doses of tacrolimus and failed to provide detectable clinical benefits. ClinicalTrials.gov identifier: NCT00436722.
Assuntos
Soro Antilinfocitário/administração & dosagem , Transplante de Fígado/métodos , Tacrolimo/administração & dosagem , Adulto , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Tacrolimo/efeitos adversosRESUMO
The treatment of lymph node metastases involving the carotid artery is controversial. The aim of the present study was to determine the outcomes of head and neck cancer patients with radiographic carotid artery involvement in neck metastases. A total of 27 patients with head and neck cancer and radiologically diagnosed advanced metastases involving the common carotid artery or internal carotid artery were enrolled. All patients underwent a primary or salvage neck dissection and surgical carotid peeling. The oncological outcome and survival of all patients were analyzed. Loco-regional control was observed in 13 of the 27 patients (48.1%). During follow-up, five patients (18.5%) developed second primaries and 11 (40.7%) developed distant metastases. The survival time was poor independent of regional control. The median overall survival was 1.55 years and disease-free survival was 0.71 year. Radiographic carotid artery involvement in neck metastases in head and neck cancer appears to correlate with a poor long-term prognosis, with a high rate of distant metastases despite loco-regional control.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Tomografia Computadorizada por Raios X , Adulto , Idoso , Artérias Carótidas/cirurgia , Feminino , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Prognóstico , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Iodine-125, in the form of 5-[125I]iododeoxyuridine (I-UdR), was incorporated into the DNA of SV40 transformed Chinese hamster embryo cells. Disintegration of the 125I led to increased cell killing with increasing dose as measured by the colony-forming ability of single cells. The D37 (the dose at which 37% of the cells survive) amounts to 95 decays per cell, corresponding to 0.66 Gy. Variations in the copy number of specific DNA sequences was measured by using dispersed cell blotting with sensitive DNA hybridizations. A 13-fold amplification of the viral DNA sequences (SV40) and a twofold amplification of two cellular oncogenes of the ras-family (Ki-ras and Ha-ras) were found. Other cellular genes, like the alpha-actin gene, were not amplified, and no variation in gene copy number was detected after incubation of cells with cold I-UdR. We suggest the observed gene amplifications are induced by the densely ionizing radiation emitted by the decay of the incorporated 125I atoms.
Assuntos
Transformação Celular Viral , Amplificação de Genes/efeitos da radiação , Radioisótopos do Iodo , Oncogenes/efeitos da radiação , Vírus 40 dos Símios , Animais , Sobrevivência Celular/efeitos da radiação , Cricetinae , Técnicas In Vitro , Vírus 40 dos Símios/genéticaRESUMO
The metabolism of radiohafnium (175Hf + 181Hf) was studied in male Sprague-Dawley rats and Chinese hamsters for periods of up to 168 days. The results were compared with similar data for 239Pu in the same rat strain. In rats and hamsters the radiohafnium organ distribution was skeleton greater than skin greater than muscle greater than liver at about 7 days postinjection. Retention of radiohafnium and plutonium was similar in plasma and liver, as were the retention times observed for other organs: Absorption of radiohafnium from the gastrointestinal tract of rats was less than 0.05%. Biochemical studies showed that the radiohafnium was bound mainly to the iron-transport protein, transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium. The metabolic behavior of radiohafnium mimics, to a large extent, that of plutonium, and it is suggested that radiohafnium can serve as a non-alpha-particle-emitting analog of plutonium for metabolic, biochemical, and selected human investigations.
Assuntos
Háfnio/metabolismo , Plutônio/metabolismo , Animais , Cricetinae , Cricetulus , Háfnio/sangue , Absorção Intestinal , Masculino , Plutônio/sangue , Radioisótopos/metabolismo , Ratos , Ratos Endogâmicos , Distribuição TecidualRESUMO
The ability of three chelating agents, dimercaptopropanesulphonate (DMPS), dimercaptosuccinic acid (DMSA), and diethylenetriaminepentaacetic acid (DPTA), to reduce the retention of platinum in the kidneys was tested in male Sprague-Dawley rats treated 24 h previously with Cisplatin. DMPS and DMSA, when given as four daily doses of 1 mMol/kg, increased the urinary excretion from 10.1% +/- 1.2% to 13.6% +/- 1.3% and 13.5% +/- 2.6%, respectively, but only DMSA caused a small but significant reduction in the kidney platinum content. DTPA was totally ineffective. It is concluded that none of these agents is likely to be useful for the reduction of Cisplatin-induced renal toxicity in the clinical situation.
Assuntos
Quelantes/farmacologia , Cisplatino/metabolismo , Rim/metabolismo , Platina/metabolismo , Succímero/farmacologia , Compostos de Sulfidrila/farmacologia , Animais , Interações Medicamentosas , Masculino , Ratos , Ratos EndogâmicosRESUMO
To evaluate some of the early effects of methymercury chloride (MMC) male rats were given 10, 20 or 30 mg MMC/kg intraperitoneally. Urine was analysed for vanilmandelic acid (VMA), leucine aminopeptidase (LAP), alkaline phosphatase (AP), and creatinine, blood for glucose-6-phosphatase (G-6-P) and glucose, serum for glutamate-oxalate-transaminase (GOT) and urea. Except for LAP and AP excretion there is no effect of MMC on the parameters investigated. However, the effects on these 2 renal enzymes are to variable to permit their use as a test for MMC toxicity.
Assuntos
Compostos de Metilmercúrio/toxicidade , Fosfatase Alcalina/urina , Animais , Creatinina/urina , Leucil Aminopeptidase/urina , Masculino , Ratos , Ácido Vanilmandélico/urinaRESUMO
Administration of various doses of the chelating agent 2,3-dimercaptopropane sodium sulfonate (Dimaval, DMPS) leads to a greatly enhanced excretion of Zn and Cu. The excretion of Co, Mn, Ni and Fe remains unchanged. The relevance of these findings to the toxicity of DMPS is discussed.
Assuntos
Dimercaprol/análogos & derivados , Oligoelementos/urina , Animais , Dimercaprol/farmacologia , Masculino , RatosRESUMO
The retention of 67Ga, 203Hg, 175 + 181Hf, 239Pu and 241Am in turpentine-induced abscesses and in normal muscle has been studied in rats for periods of up to 126 days after radionuclide injection (129 days after turpentine). The results show that although the uptake of 203Hg is about 7 times greater in the abscess than in control muscle, the half time of the nuclide is similar in both tissues, T1/2 = 5 days. The remaining radionuclides studied all show a similar retention time in control muscle, average T1/2 = 12.5 days, and a more prolonged retention in the abscess tissue, average T1/2 = 47 days, although in both control and abscess tissue the uptake of the radionuclides showed quite large metal-specific variations. It is concluded that for radionuclides which are transported on transferrin in the blood and which deposit in lysosomes within cells a common metal clearance mechanism may operate in normal muscle and a second general mechanism may operate in abscess tissue. The radionuclide concentration difference between normal and abscess tissue ranged from 8 (67Ga) to 27 (239Pu); thus the radiation dose delivered to the inflamed tissue was between about 30 and 100 times greater than in normal muscle.
Assuntos
Abscesso/metabolismo , Doenças Musculares/metabolismo , Radioisótopos/metabolismo , Abscesso/induzido quimicamente , Amerício/metabolismo , Animais , Radioisótopos de Gálio/metabolismo , Háfnio/metabolismo , Masculino , Radioisótopos de Mercúrio/metabolismo , Músculos/metabolismo , Doenças Musculares/induzido quimicamente , Plutônio/metabolismo , Ratos , Ratos Endogâmicos , TerebintinaRESUMO
The accumulation of ten metals in turpentine-induced abscesses of different ages has been studied in rats. The maximum metal concentration ratio between the abscesses and the non-inflamed contralateral muscle was greater than 1 for all the metals studied, the lowest being 2.5 for Zn, and the highest 36 for Th. The ratio remains greater than 1 for more than 28 days for all metals except Ga. There is a marked increase of beta-glucuronidase activity in the inflamed tissue which correlates well with the metal concentration. In contrast the acid phosphatase activity was reduced for the first few days after turpentine injection and never rose above the normal muscle activity. The metals showing the highest uptake in the inflamed lesion appear to be those which are transported in the blood as a transferrin complex.
Assuntos
Abscesso/metabolismo , Metais/metabolismo , Abscesso/enzimologia , Fosfatase Ácida/metabolismo , Animais , Glucuronidase/metabolismo , Masculino , Músculos/metabolismo , Radioisótopos/análise , RatosRESUMO
The binding of Pu to liver cell membranes was studied and compared with that of iron with which plutonium shares some physiological properties. The binding of both metals is sensitive to pH changes and they can be dissociated from their binding sites by chelating agents and transferrin. The metal-binding proteins can be extracted with detergents. Both metals have at least two binding sites, the molecular weights of which lie between 150 and 400 kDa; the isoelectric points for iron are 5.5 and 6.5, and for plutonium 6.0 and 6.5. The significance of these results for plutonium uptake into liver cells is discussed.
Assuntos
Fígado/metabolismo , Nitratos , Plutônio/metabolismo , Animais , Membrana Celular/metabolismo , Cloretos , Compostos Férricos/metabolismo , Radioisótopos de Ferro , Cinética , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Ligação Proteica , Ratos , Transferrina/metabolismoRESUMO
Exposure of Co631 cells to 239Pu-citrate leads to continuous irradiation and results in increasing cell death which depends on dose and incubation time of the metal. The D37 is calculated to be 0.13 Gy. Plutonium-239 induces the amplification of the integrated SV40 sequences of the Co631 cells. Other cellular genes such as the alpha-actin gene were not amplified, indicating that the SV40-gene amplification is a selective process. Southern blot analysis of genomic DNA shows that not all S40 sequences are equally amplified. Excised sequences of the SV40 genome only appear after an exposure time of 4 days.
Assuntos
Sobrevivência Celular/efeitos da radiação , Plutônio , Animais , Linhagem Celular , Transformação Celular Neoplásica , Cricetinae , Cricetulus , DNA/efeitos da radiação , DNA Viral/efeitos da radiação , Relação Dose-Resposta à Radiação , Vírus 40 dos Símios/genéticaRESUMO
The accumulation of Cd in the kidneys is enhanced markedly if chelating agents that contain SH-groups like 2,3 dimercaptopropanol (BAL) are injected immediately after the metal. This is not a transient effect but persists for more than 3 d. It is less pronounced at higher chelate doses or when the pH of urine is increased. Our experiments indicate that chelating agents, which form unstable complexes at acid pH and are able to pass through the cell membrane, will cause metal accumulation in the kidneys.
Assuntos
Cádmio/metabolismo , Quelantes/farmacologia , Rim/metabolismo , Compostos de Sulfidrila/farmacologia , Alcalose/metabolismo , Animais , Carga Corporal (Radioterapia) , Cádmio/sangue , Radioisótopos de Cádmio , Dimercaprol/farmacologia , Concentração de Íons de Hidrogênio , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Ratos , Ratos Endogâmicos , Unitiol/farmacologiaRESUMO
Cultures of epithelial rat kidney cells were used to investigate the effect of lead on protein and DNA metabolism. Lead-adapted cells were cultured in 5 and 10 microM Pb(NO3)2 for several months and subsequently showed the same growth characteristics but a higher resistance to increased lead doses than untreated cells. Both normal and adapted cell types were exposed to lead nitrate in concentrations from 5 to 1000 microM for incubation periods of from 1 to 24 h. 3H-leucine incorporation was increased in 10 microM lead by up to 140% in normal but not in adapted cells, pointing to a resistance forming mechanism. Not only is the overall rate of protein synthesis increased, but separations of cytosolic proteins by SDS-polyacrylamide electrophoresis indicate the novel or increased synthesis of several proteins. A difference could also be observed in the DNA metabolism, where normal cells show a very pronounced increase of up to 900% after 24 h of incubation. This was not observed in adapted cells.
Assuntos
DNA/metabolismo , Rim/metabolismo , Chumbo/farmacologia , Proteínas/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Citosol/efeitos dos fármacos , Citosol/metabolismo , Eletroforese em Gel de Poliacrilamida , Rim/efeitos dos fármacos , Cinética , Leucina/metabolismo , RatosRESUMO
The binding of the 59Fe and 239Pu complexes of transferrin and 125I labelled transferrin [Tf (125I)] to isolated cell membranes of rat liver has been studied. Transferrin forms a complex with an integral protein of the membrane which has an apparent molecular weight of about 180 kDa and is stable only at pH 7.4. Iron-59 is eluted from Sephacryl S 300 columns together with Tf (125I) or the Tf-membrane protein complex while 239Pu seems to be bound to different membrane protein(s). After isolation of the Tf-binding protein from 35S-labelled membranes and incubation with one of the metal-Tf complexes 59Fe elutes from a Sephacryl S 300 column together with 35S at an apparent molecular weight of ca. 250 kDa while 239Pu is found in fractions of lower molecular weight. It is concluded from these results that there are Tf-receptors in the liver cell membrane to which iron transferrin may bind. Plutonium, however, seems to be dissociated from Tf and bound directly to other membrane proteins.
Assuntos
Membrana Celular/metabolismo , Radioisótopos de Ferro , Fígado/ultraestrutura , Plutônio , Transferrina/metabolismo , Animais , Cromatografia de Afinidade , Cromatografia em Gel , Radioisótopos do Iodo , Radioisótopos de Ferro/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Peso Molecular , Plutônio/metabolismo , Ligação Proteica , Ratos , Ratos Endogâmicos , Radioisótopos de EnxofreRESUMO
Exposure of Co631 cells to plutonium leads to increasing cell death depending on the dose and incubation time. The effects, however, are more pronounced with 239Pu, than with 238Pu. Uptake and binding of the two radionuclides during a 5-h incubation are about equal, but 238Pu is lost more rapidly from the cell. There are also differences in the subcellular distribution which lead to a pronounced difference in the distribution of radioactivity. The influence of these differences in the handling of 238Pu and 239Pu by the cell and of the mass difference on the radiotoxicity of the radionuclides is discussed.
Assuntos
Plutônio/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Células Cultivadas , Cricetinae , Cricetulus , Plutônio/metabolismo , Radioisótopos/metabolismo , Radioisótopos/toxicidadeRESUMO
Penicillamine, a fairly stable mercaptoamino acid, undergoes virtually no metabolic degradation in mammals. The substance, especially the L-form, is taken up by most organs, in particular, by those with high collagen content. L-penicillamine shows more affinity for the mature collagen fraction than does D-penicillamine, which is distributed almost equally between the 2 immature fractions. Both enantiomers are bound to plasma proteins, especially to albumin, through S-S bridges. Penicillamine enhances renal copper excretion in normal, as well as in copper-loaded, man and animals. Results reported concerning other trace elements are contradictory.