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1.
BMC Gastroenterol ; 22(1): 82, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216547

RESUMO

BACKGROUND: In patients with severe polycystic liver disease (PLD), there is a need for new treatments. Estrogens and possibly other female sex hormones stimulate growth in PLD. In some patients, liver volume decreases after menopause. Female sex hormones could therefore be a target for therapy. The AGAINST-PLD study will examine the efficacy of the GnRH agonist leuprorelin, which blocks the production of estrogen and other sex hormones, to reduce liver growth in PLD. METHODS: The AGAINST-PLD study is an investigator-driven, multicenter, randomized controlled trial. Institutional review board (IRB) approval was received at the University Medical Center of Groningen and will be collected in other sites before opening these sites. Thirty-six female, pre-menopausal patients, with a very large liver volume for age (upper 10% of the PLD population) and ongoing liver growth despite current treatment options will be randomized to direct start of leuprorelin or to 18 months standard of care and delayed start of leuprorelin. Leuprorelin is given as 3.75 mg subcutaneously (s.c.) monthly for the first 3 months followed by 3-monthly depots of 11.25 mg s.c. The trial duration is 36 months. MRI scans to measure liver volume will be performed at screening, 6 months, 18 months, 24 months and 36 months. In addition, blood will be drawn, DEXA-scans will be performed and questionnaires will be collected. This design enables comparison between patients on study treatment and standard of care (first 18 months) and within patients before and during treatment (whole trial). Main outcome is annualized liver growth rate compared between standard of care and study treatment. Secondary outcomes are PLD disease severity, change in liver growth within individuals and (serious) adverse events. The study is designed as a prospective open-label study with blinded endpoint assessment (PROBE). DISCUSSION: In this trial, we combined the expertise of hepatologist, nephrologists and gynecologists to study the effect of leuprorelin on liver growth in PLD. In this way, we hope to stop liver growth, reduce symptoms and reduce the need for liver transplantation in severe PLD. Trial registration Eudra CT number 2020-005949-16, registered at 15 Dec 2020. https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-005949-16 .


Assuntos
Leuprolida , Hepatopatias , Feminino , Humanos , Cistos , Leuprolida/uso terapêutico , Hepatopatias/tratamento farmacológico , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Br J Surg ; 104(7): 907-917, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28394402

RESUMO

BACKGROUND: Experimental studies have suggested that end-ischaemic dual hypothermic oxygenated machine perfusion (DHOPE) may restore hepatocellular energy status and reduce reperfusion injury in donation after circulatory death (DCD) liver grafts. The aim of this prospective case-control study was to assess the safety and feasibility of DHOPE in DCD liver transplantation. METHODS: In consecutive DCD liver transplantations, liver grafts were treated with end-ischaemic DHOPE. Outcome was compared with that in a control group of DCD liver transplantations without DHOPE, matched for donor age, donor warm ischaemia time, and recipient Model for End-stage Liver Disease (MELD) score. All patients were followed for 1 year. RESULTS: Ten transplantations involving liver grafts treated with DHOPE were compared with 20 control procedures. There were no technical problems. All 6-month and 1-year graft and patient survival rates were 100 per cent in the DHOPE group. Six-month graft survival and 1-year graft and patient survival rates in the control group were 80, 67 and 85 per cent respectively. During DHOPE, median (i.q.r.) hepatic adenosine 5'-triphosphate (ATP) content increased 11-fold, from 6 (3-10) to 66 (42-87) µmol per g protein (P = 0·005). All DHOPE-preserved livers showed excellent early function. At 1 week after transplantation peak serum alanine aminotransferase (ALT) and bilirubin levels were twofold lower in the DHOPE group than in the control group (ALT: median 966 versus 1858 units/l respectively, P = 0·006; bilirubin: median 1·0 (i.q.r. 0·7-1·4) versus 2·6 (0·9-5·1) mg/dl, P = 0·044). None of the ten DHOPE-preserved livers required retransplantation for non-anastomotic biliary stricture, compared with five of 20 in the control group (P = 0·140). CONCLUSION: This clinical study of end-ischaemic DHOPE in DCD liver transplantation suggests that the technique restores hepatic ATP, reduces reperfusion injury, and is safe and feasible. RCTs with larger numbers of patients are warranted to assess the efficacy in reducing post-transplant biliary complications.


Assuntos
Hipotermia Induzida/métodos , Transplante de Fígado , Preservação de Órgãos/métodos , Obtenção de Tecidos e Órgãos , Estudos de Casos e Controles , Estudos de Viabilidade , Feminino , Sobrevivência de Enxerto , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Oxigênio , Perfusão/métodos , Estudos Prospectivos , Resultado do Tratamento
3.
Br J Surg ; 97(5): 744-53, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20393979

RESUMO

BACKGROUND: The outcome of orthotopic liver transplantation (OLT) with controlled graft donation after cardiac death (DCD) is usually inferior to that with graft donation after brain death (DBD). This study compared outcomes from OLT with DBD versus controlled DCD donors with predefined restrictive acceptance criteria. METHODS: All adult recipients in the Netherlands in 2001-2006 with full-size OLT from DCD (n = 55) and DBD (n = 471) donors were included. Kaplan-Meier, log rank and Cox regression analyses were used. RESULTS: One- and 3-year patient survival rates were similar for DCD (85 and 80 per cent) and DBD (86.3 and 80.8 per cent) transplants (P = 0.763), as were graft survival rates (74 and 68 per cent versus 80.4 and 74.5 per cent; P = 0.212). The 3-year cumulative percentage of surviving grafts developing non-anastomotic biliary strictures was 31 per cent after DCD and 9.7 per cent after DBD transplantation (P < 0.001). The retransplantation rate was similar overall (P = 0.081), but that for biliary stricture was higher in the DCD group (P < 0.001). Risk factors for 1-year graft loss after DBD OLT were transplant centre, recipient warm ischaemia time and donor with severe head trauma. After DCD OLT they were transplant centre, donor warm ischaemia time and cold ischaemia time. DCD graft was a risk factor for non-anastomotic biliary stricture. CONCLUSION: OLT using controlled DCD grafts and restrictive criteria can result in patient and graft survival rates similar to those of DBD OLT, despite a higher risk of biliary stricture.


Assuntos
Morte Encefálica , Transplante de Fígado/mortalidade , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/métodos , Adolescente , Adulto , Criança , Seleção do Doador/métodos , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Resultado do Tratamento
4.
Transpl Immunol ; 61: 101304, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32371150

RESUMO

The rapid emergence of the COVID-19 pandemic is unprecedented and poses an unparalleled obstacle in the sixty-five year history of organ transplantation. Worldwide, the delivery of transplant care is severely challenged by matters concerning - but not limited to - organ procurement, risk of SARS-CoV-2 transmission, screening strategies of donors and recipients, decisions to postpone or proceed with transplantation, the attributable risk of immunosuppression for COVID-19 and entrenched health care resources and capacity. The transplant community is faced with choosing a lesser of two evils: initiating immunosuppression and potentially accepting detrimental outcome when transplant recipients develop COVID-19 versus postponing transplantation and accepting associated waitlist mortality. Notably, prioritization of health care services for COVID-19 care raises concerns about allocation of resources to deliver care for transplant patients who might otherwise have excellent 1-year and 10-year survival rates. Children and young adults with end-stage organ disease in particular seem more disadvantaged by withholding transplantation because of capacity issues than from medical consequences of SARS-CoV-2. This report details the nationwide response of the Dutch transplant community to these issues and the immediate consequences for transplant activity. Worrisome, there was a significant decrease in organ donation numbers affecting all organ transplant services. In addition, there was a detrimental effect on transplantation numbers in children with end-organ failure. Ongoing efforts focus on mitigation of not only primary but also secondary harm of the pandemic and to find right definitions and momentum to restore the transplant programs.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Transplante de Órgãos/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Adolescente , Betacoronavirus/isolamento & purificação , COVID-19 , Criança , Pré-Escolar , Humanos , Países Baixos , Pandemias , SARS-CoV-2 , Obtenção de Tecidos e Órgãos , Transplantados
5.
Science ; 264(5164): 1437-9, 1994 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-17838427

RESUMO

Recent studies have implied that (Mg, Fe)SiO(3)-perovskite, a likely dominant mineral phase in the lower mantle, may have a high melting temperature. The implications of these findings for the dynamics of the lower mantle were investigated with the use of numerical convection models. The results showed that low homologous temperatures (0.3 to 0.5) would prevail in the modeled lower mantle, regardless of the effective Rayleigh number and internal heating rates. High-temperature ductile creep is possible under relatively cold conditions. In models with low rates of internal heating, local maxima of viscosity developed in the mid-lower mantle that were similar to those obtained from inversion of geoid, topography, and plate velocities.

6.
Open Forum Infect Dis ; 6(8)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31404927

RESUMO

Ribavirin is effective for treating immunocompromised patients with chronic hepatitis E virus infection. However, ribavirin treatment is not always successful. We describe 3 solid organ transplant recipients treated with sofosbuvir and ribavirin after failing ribavirin monotherapy. Complete elimination of hepatitis E virus could not be achieved.

7.
Ned Tijdschr Geneeskd ; 162: D2159, 2018.
Artigo em Holandês | MEDLINE | ID: mdl-29519259

RESUMO

OBJECTIVE: To calculate the chance of receiving a liver transplant for patients on the liver transplant waiting list in the Netherlands. DESIGN: Retrospective cohort research. METHOD: Data of all patients in the Netherlands on the waiting list for liver transplantation, from the introduction of the model of end-stage liver disease score on 16th December 2006 through to 31st December 2013 were collected. Survival analysis was computed with competing risk analyses. RESULTS: A total of 851 patients were listed, of whom 236 patients with hepatocellular carcinoma, 147 patients with primary sclerosing cholangitis, 142 patients with post-alcoholic liver disease, 93 patients with metabolic liver disease, 78 with viral hepatitis and 155 patients listed for other indications. The median waiting time till transplantation was 196 days. The chance to be transplanted at two years from listing was 65% and the risk of death was 17%. Patients with metabolic liver disease had the highest chance of undergoing liver transplantation. Patients with viral hepatitis were at highest risk of death while on the list, as well as having the lowest chance of undergoing liver transplantation. CONCLUSION: Our study shows a 65% chance of getting transplanted in time after a median waiting time of 6 months in the Netherlands. Sadly, 1 in 6 patients die before liver transplantation can be performed, with the highest risk of death occurring in patients with viral hepatitis.


Assuntos
Doença Hepática Terminal , Transplante de Fígado , Listas de Espera/mortalidade , Doença Hepática Terminal/epidemiologia , Doença Hepática Terminal/cirurgia , Humanos , Transplante de Fígado/métodos , Transplante de Fígado/estatística & dados numéricos , Avaliação das Necessidades , Países Baixos/epidemiologia , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida
8.
Neth J Med ; 65(7): 252-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17675671

RESUMO

BACKGROUND: Liver transplantation was started in our centre as early as 1979. We have studied the clinical outcome of patients surviving longer than 15 years, with special interest for the broad range of comorbidity and the self-perceived quality of life. METHODS: All patients who underwent a liver transplantation at an adult age, between March 1979 and February 1991, and who had survived at least 15 years were eligible for the study. Data were collected from the medical records. Health-related quality of life was assessed using the Six-Dimensional EuroQol test. RESULTS: The five-year survival of patients alive 15 years after transplantation was 78%. Thirty-seven patients are currently alive with a median follow-up of 18.8 years (range 15.0 to 26.8) after transplantation. Comorbidity consists predominantly of overweight (57%), osteoporosis (49%), de novo cancer (38%, mainly skin cancer), hypertension (38%), cardiovascular events (19%), diabetes mellitus (22%), cataract (24%), and renal clearance<50 ml/min (11%). The pattern of comorbidity seems to relate to the type of immunosuppression which consisted mainly of prednisolone and azathioprine. Quality of life was perceived as satisfactory (7 on a scale of 0 to 10). However, about half of the patients reported limitations in the domains mobility, usual activities and pain/discomfort. In addition a minority reported some anxiety or depression. CONCLUSION: The outcome of liver transplantation in this early cohort of patients is fairly good. Improvements may be achieved by adaptations in the immunosuppressive regimen.


Assuntos
Nível de Saúde , Transplante de Fígado/psicologia , Avaliação de Resultados em Cuidados de Saúde , Qualidade de Vida , Perfil de Impacto da Doença , Sobreviventes/psicologia , Adulto , Idoso , Comorbidade , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Hepatopatias/cirurgia , Transplante de Fígado/imunologia , Pessoa de Meia-Idade , Países Baixos , Tempo
9.
Neth J Med ; 65(10): 372-80, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18057459

RESUMO

Liver transplantation has been an accepted treatment for end-stage liver disease since the 1980s. Currently it is a highly successful treatment for this indication. The aim of this review is to give a general update on recent developments in the field of liver transplantation. In the last decades considerable progress has been made in the care of liver transplant candidates and recipients. At present the one- and five-year patient survival rates are approximately 85 and 75%. The indications for liver transplantation are shifting and the number of absolute contraindications is decreasing. In the coming years, an increase in the number of transplant candidates can be expected. An important problem is the shortage of donor organs, for which many solutions are being explored. A recently introduced method for recipient selection is the MELD score using simple laboratory measurements. Perioperative care at the present time is characterised by a high degree of standardisation and rapidly declining blood loss during transplantation. Long-term care includes awareness and management of recurrent disease. Important causes of morbidity and mortality such as de novo malignancies and cardiovascular disease should be adequately screened for and managed. With the increasing success of liver transplantation, physicians should aim at reaching a normal life expectancy and quality of life for transplant recipients.


Assuntos
Hepatopatias/cirurgia , Transplante de Fígado/tendências , Humanos , Terapia de Imunossupressão , Transplante de Fígado/métodos , Prognóstico , Qualidade de Vida , Doadores de Tecidos , Transplante
10.
Diagn Cytopathol ; 35(4): 227-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17351934

RESUMO

Cytomegalovirus (CMV) infected cells in cervical smears are a rare finding but may have severe consequences. We describe the presence of characteristic "owl eye" cells in a conventional cervical smear. Medical history revealed a liver transplantation from a CMV seropositive donor 1 yr earlier. The patient experienced a delayed primary CMV infection 6 mo after transplantation. The current CMV infection was considered to be either a persisting manifestation of that primary infection or a reactivation. Since the patient experienced no clinical symptoms, it was decided to "wait and see". Infections with cytomegalovirus in immunocompromised patients may present with aspecific symptoms, but may lead to severe organ-threatening disease such as acute or chronic transplantation loss in transplant recipients. Although in the present case no serious consequences occurred, we stress that it is important to recognize these cells and report this finding promptly to the referring physician to prevent possible severe morbidity.


Assuntos
Colo do Útero/patologia , Colo do Útero/virologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/patologia , Hospedeiro Imunocomprometido , Transplante de Fígado/efeitos adversos , Infecções por Citomegalovirus/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Esfregaço Vaginal
11.
Int J Antimicrob Agents ; 49(3): 379-382, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28185946

RESUMO

Chronic hepatitis C virus (HCV) infection can cause severe liver cirrhosis, for which liver transplantation is the only therapy. To prevent organ rejection, transplanted patients are treated with immunosuppressive agents. We describe two transplanted patients treated with tacrolimus who were simultaneously treated with direct-acting antivirals (DAAs) for their chronic HCV infection. No pharmacokinetic drug-drug interactions (DDIs) were expected between tacrolimus and the selected DAAs. However, in both patients, tacrolimus plasma concentrations decreased during HCV treatment. We hypothesise that decreased plasma concentrations were not caused by a DDI but were an indirect result of the clearance of the HCV infection. During chronic HCV infection, pro-inflammatory cytokines may inhibit cytochrome P450 (CYP) enzymes, which are primarily responsible for tacrolimus metabolism. If this is true, then with clearance of the virus the activity of these enzymes will normalise and tacrolimus metabolism will increase. These changes were clinically relevant because the tacrolimus dosage needed to be adjusted. Therefore, physicians should be aware that CYP substrates with narrow therapeutic ranges might require dose adaption during HCV therapy with DAAs.


Assuntos
Antivirais/administração & dosagem , Interações Medicamentosas , Hepatite C Crônica/tratamento farmacológico , Imunossupressores/sangue , Plasma/química , Tacrolimo/sangue , Idoso , Antivirais/farmacocinética , Sistema Enzimático do Citocromo P-450/metabolismo , Hepatite C Crônica/cirurgia , Humanos , Imunossupressores/farmacocinética , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Tacrolimo/farmacocinética , Transplantados
12.
Eur J Cancer ; 27(9): 1151-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1835627

RESUMO

Preclinical investigations were performed with glucose administration in WAG/Rij rats carrying the rhabdomyosarcoma BA1112 in two sites per animal: one in the subcutis of the flank (for pH measurements in the tumour tissue) and one in the transparent "sandwich" chamber for measuring the erythrocyte flux in the tumour tissue as an indication for changes in tumour blood flow. A glucose solution (20%) was slowly infused intravenously in a range of dose levels, similar to those reported for inducing long-term hyperglycaemia in man. The eventual aim of such investigations is to sensitise tumours for hyperthermic treatment. This approach is not new, but the present experiments were performed with the aim to explore the level of the minimal amount of glucose which would nonetheless yield a likely therapeutic effect. Endpoints in this study were the blood glucose level and pH and the relative erythrocyte flux in the tumour tissue. Obviously, as one would expect, many significant changes in the various parameters were found as a response to administration of glucose. However, the changes in the blood glucose level, the induced decrease in tumour pH and the influence of the tumour volume did not show a well-defined relationship which was reliable enough to predict the exact influence of the various parameters on the magnitude of the desired changes in individual animals and/or tumours. This was probably caused by interfering differences in physiological feedback mechanisms. Nonetheless, the data indicate that the optimal effect was not obtained with the highest treatment level, but with moderate doses of glucose, i.e. 2.4-3 g.kg/h which induced a satisfactory tumour acidification of 0.25 pH units. This may turn out to a clinically useful pH drop for enhancing the cytotoxic effect of hyperthermia. The erythrocyte flux through the tumour tissue does not appear to be influenced to a sizeable extent by such a treatment.


Assuntos
Glucose/administração & dosagem , Neoplasias Experimentais/química , Rabdomiossarcoma/química , Animais , Glicemia/química , Relação Dose-Resposta a Droga , Feminino , Concentração de Íons de Hidrogênio , Neoplasias Experimentais/sangue , Ratos , Rabdomiossarcoma/sangue
13.
Int J Radiat Oncol Biol Phys ; 48(1): 233-40, 2000 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10924994

RESUMO

PURPOSE: To evaluate the potential effects of tumor hypoxia induced by afterloading catheter implantation on the effectiveness of brachytherapy in a rat tumor model. METHODS AND MATERIALS: Afterloading catheters (4) were implanted in subcutaneously growing R1M rhabdomyosarcoma in female Wag/Rij rats. A MicroSelectron (Nucletron) was used for interstitial high-dose-rate irradiation ((192)Ir). Tumor oxygenation, perfusion, and cell survival were assessed by pO(2) histography (Eppendorf), Tc-99m injection, and excision assay, respectively. RESULTS: Tumor perfusion was markedly reduced at 1 h after catheter implantation (33.9 +/- 6.0% (SEM, n = 9) of control) and partly recovered after 5 h (61.5 +/- 12.2%). At 24 h, the perfusion level reached control values (100.6 +/- 25.7%), but was highly variable with some of the tumors showing hardly any recovery at all. Tumor oxygenation showed a similar pattern, but with less recovery. Median pO(2) readings were 13.5, 1.2, and 5.3 mm Hg before and at 1 and 24 h after implantation, respectively (7 tumors). The percentages of pO(2) readings

Assuntos
Braquiterapia , Hipóxia Celular/fisiologia , Consumo de Oxigênio/fisiologia , Animais , Artefatos , Braquiterapia/instrumentação , Cateterismo/efeitos adversos , Hipóxia Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Feminino , Consumo de Oxigênio/efeitos da radiação , Pressão Parcial , Radiobiologia , Ratos , Fluxo Sanguíneo Regional/efeitos da radiação , Rabdomiossarcoma/irrigação sanguínea , Rabdomiossarcoma/fisiopatologia , Rabdomiossarcoma/radioterapia , Fatores de Tempo , Células Tumorais Cultivadas/efeitos da radiação
14.
Int J Radiat Oncol Biol Phys ; 41(2): 415-24, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9607360

RESUMO

PURPOSE: Testicular germ cell tumors (TGCTs) represent one of the few tumor types that are curable by antineoplastic therapy, probably due to the high sensitivity of this neoplasm to induction of apoptosis by chemotherapeutic agents and/or ionizing radiation. Here, we tested cell susceptibility to radiation-induced apoptosis in a panel of TGCT cell lines and attempted to correlate this with the known potentially relevant molecular determinants (p53 gene status and Bcl-2 family proteins) of apoptosis. METHODS AND MATERIALS: Induction of apoptosis by gamma-radiation was morphologically recognized in NT2, NCCIT, S2, and 2102 EP using Hoechst/PI staining and additionally confirmed by Western blot analysis of PARP cleavage. The p53 gene status was estimated by sequence analysis. Expression of p21/WAF/CIP was determined by Northern blot analysis and immunoblotting was used to monitor p53, Bax, Bcl-2, Bcl-x, and Bak protein levels. In vitro colony formation was studied to establish clonogenic survival curves. RESULTS: NT2 and NCCIT appeared to be susceptible for radiation-induced apoptosis, contrasting 2102 EP and S2 which were highly resistant. Sequence analysis showed that NT2, S2, and 2102 EP are homozygous for wild-type p53 (wtp53), whereas NCCIT contains mutant p53 (mtp53). NT2 and 2102 EP cells showed radiation-induced p53 upregulation, while NCCIT (mtp53) and S2 (no p53 protein) cells did not. Consistently, gamma-radiation-induced DNA damage resulted in a p53-dependent transactivation of the p21/WAF/CIP gene in NT2 and 2102 EP, but not in mtp53-containing NCCIT cells and p53 nonexpressing S2 cells. Constitutive expression of Bax, Bcl-2, Bcl-x, and Bak was not affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis. A discrepancy was found between apoptosis and reproductive death. CONCLUSIONS: The present study revealed that: i) the presence of wtp53 may not be absolutely required for the hypersensitivity for radiation-induced apoptosis in TGCT cell lines, ii) the molecular mechanism underlying the unique radiosensitivity was independent of the expression of Bcl-2 family proteins, and iii) cell susceptibility to apoptosis induction is not sufficiently informative to predict intrinsic radiosensitivity as determined by clonogenic survival.


Assuntos
Apoptose , Germinoma/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Testiculares/metabolismo , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , DNA de Neoplasias/efeitos da radiação , Relação Dose-Resposta à Radiação , Genes p53/efeitos da radiação , Germinoma/patologia , Humanos , Masculino , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Testiculares/patologia , Células Tumorais Cultivadas/efeitos da radiação , Proteína Supressora de Tumor p53/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2 , Proteína bcl-X
15.
Int J Radiat Oncol Biol Phys ; 18(1): 51-7, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2298635

RESUMO

The influence of hyperthermia on tissue pH was investigated using a modified version of the fiber optic monitoring system. This newly developed system was tested for use in tissues and found to be suitable for pH measurement during microwave induced hyperthermia. The fiber optic pH probe (0.7 mm diameter) could be easily used in the electromagnetic fields produced by the microwave applicators, whereas only the display unit required some shielding. Tissue pH of experimental and clinical tumors was measured concurrently with local microwave hyperthermia treatment. The mean initial intratumor pH of a rat rhabdomyosarcoma was 7.03 (SD 0.13, n = 19) and the pH of human subcutis was 7.45 (SD 0.02, n = 8). In rat tumor a primary pH decrease was observed during heating which was fully reversed during cooling. The coefficient of temperature dependence was -0.016 pH unit/degree C (SD 0.004, n = 12). After approximately 1 hr of heating at 43 degrees C a further pH decrease of 0.1-0.3 unit occurred which was not reversed directly after treatment. Measurements during clinical local microwave hyperthermia treatments after radiotherapy revealed similar changes in pH values, primary as well as secondary. The estimated coefficient of temperature dependence for the reversible pH change, which occurred in subcutis as well as in tumor tissue, was -0.016 pH unit/degree C (SD 0.004, n = 12). The fiber optic pH measurement system is expected to be a valuable tool in the thorough investigation of temperature and time related pH changes in tumor during experimental as well as clinical hyperthermia treatment.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Tecnologia de Fibra Óptica/instrumentação , Hipertermia Induzida , Neoplasias/metabolismo , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Feminino , Micro-Ondas/uso terapêutico , Neoplasias/terapia , Fibras Ópticas , Ratos , Ratos Endogâmicos , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/terapia
16.
Int J Radiat Oncol Biol Phys ; 49(5): 1351-60, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11286843

RESUMO

PURPOSE: In clinical brachytherapy, there is a tendency to replace continuous low-dose-rate (LDR) irradiation by either single-dose or fractionated high-dose-rate (HDR) irradiation. In this study, the equivalence of LDR treatments and fractionated HDR (2 fractions/day) or pulsed-dose-rate (PDR, 4 fractions/day) schedules in terms of tumor cure was investigated in an experimental tumor model. METHODS AND MATERIALS: Tumors (rat rhabdomyosarcoma R1M) were grown s.c. in the flank of rats and implanted with 4 catheters guided by a template. All interstitial radiation treatment (IRT) schedules were given in the same geometry. HDR was given using an (192)Ir single-stepping source. To investigate small fraction sizes, part of the fractionated HDR and PDR schedules were applied after an external irradiation (ERT) top-up dose. The endpoint was the probability of tumor control at 150 days after treatment. Cell survival was estimated by excision assay. RESULTS: Although there was no fractionation effect for fractionated HDR given in 1 or 2 fractions per day, TCD(50)-values were substantially lower than that for LDR. A PDR schedule with an interfraction interval of 3 h (4 fractions/day), however, was equivalent to LDR. The combination of ERT and IRT resulted in a remarkably increased tumor control probability in all top-up regimens, but no difference was found between 2 or 4 fractions/day. Catheter implantation alone decreased the TCD(50) for single-dose ERT already by 17.4 Gy. Cell viability assessed at 24 h after treatment demonstrated an increased effectiveness of interstitial treatment, but, after 10 Gy ERT followed by 10 Gy IRT (24-h interval), it was not less than that calculated for the combined effect of these treatments given separately. CONCLUSION: In full fractionation schedules employing large fractions and long intervals, the sparing effect of sublethal damage repair may be significantly counteracted by reoxygenation. During 3-h intervals, however, repair may be largely completed with only partial reoxygenation causing PDR schedules to be less effective than fractionated HDR, and equivalent to LDR. Brachytherapy with clinically sized fractions after a large external top-up dose showed a remarkable increase in tumor control rate with no effect of fractionation (up to 4 fractions/day), which could not be fully explained by differences in dose distribution or in the cell viability assessed after treatment. This suggests a longer lasting effect on cell survival or radiosensitivity associated with catheter implantation shortly after the top-up dose.


Assuntos
Braquiterapia/métodos , Fracionamento da Dose de Radiação , Rabdomiossarcoma/radioterapia , Animais , Sobrevivência Celular , Relação Dose-Resposta à Radiação , Feminino , Modelos Logísticos , Modelos Animais , Transplante de Neoplasias , Radiobiologia , Ratos , Fatores de Tempo
17.
Int J Radiat Oncol Biol Phys ; 50(3): 783-92, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11395248

RESUMO

PURPOSE: To establish dose-effect relationships for tumor acidification induced by heat and glucose as a basis for testing the value of adding glucose administration to combined heat and x-ray treatment at clinically achievable glucose and temperature levels. METHODS AND MATERIALS: Rhabdomyosarcoma BA1112 was grown s.c. in the upper leg of 16-20-week-old Wag/Rij rats. Animals were given 2 consecutive 100-min periods of saline (S) or glucose (G) infusion, while keeping tumor temperature at 37 degrees, 42 degrees, or 43 degrees C for 1 or 2 periods, in various combinations, each involving 6 animals. Glucose was infused i.v. as a 20% solution at 2.4-3 g/kg/h. Tumors were heated using 2,450-MHz electromagnetic radiation, and tumor pH was measured using a 0.7 mm fiberoptic probe. RESULTS: Mean overall baseline pH was 7.00 (SD 0.10). The change induced by G37G43 (i.e., glucose infusion for a full 200 min, first 100 min at 37 degrees C, final 100 min at 43 degrees C) was -0.48 +/- 0.03 (SEM) pH units, and -0.17 +/- 0.03 for S37S43. The effect of G37G42 was -0.37 +/- 0.03 pH units, compared with -0.08 +/- 0.02 for S37S42 and -0.28 +/- 0.04 for glucose alone (G37G37). Glucose was less effective when given after or fully parallel to heating: -0.21 +/- 0.02 pH units for S43G37 and -0.37 +/- 0.02 for G43G43. CONCLUSION: The glucose-induced tumor pH drop is much more pronounced than that induced by heat, both of which are dose dependent. The effects of glucose and heat seem additive if heating is started when glucose-induced acidification has reached its plateau level, but the overall effect is diminished if administration is fully simultaneous or in reversed order. Schedule G37G43 is optimal with respect to tumor acidification. Its predicted superiority in thermoradiotherapy as compared with S37S42, S37S43, and G37G42 treatment regimens was confirmed in a subsequent experimental tumor control study.


Assuntos
Glicemia/metabolismo , Glucose/farmacologia , Hipertermia Induzida , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/terapia , Animais , Terapia Combinada , Relação Dose-Resposta a Droga , Feminino , Concentração de Íons de Hidrogênio , Ratos , Rabdomiossarcoma/radioterapia
18.
Int J Radiat Oncol Biol Phys ; 50(3): 793-801, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11395249

RESUMO

PURPOSE: To assess the therapeutic gain (at the TCD(50) level) that can be obtained by boosting thermoradiotherapy with intravenous glucose infusion at different temperatures. This completes our series of studies to determine the optimal conditions and the effectiveness of glucose administration at clinically achievable glucose levels and treatment temperatures. METHODS AND MATERIALS: Subcutaneous rat rhabdomyosarcoma BA1112 was irradiated with graded single doses of 300-kV X-rays (dose range 0-60 Gy). Fifteen minutes after irradiation, a 100-min intravenous infusion was started, consisting of either glucose (20% solution, 2.4-3 g/kg/h) or saline as a control. Then heat was applied to the tumors at 42 degrees C or 43 degrees C (water bath) during a subsequent 100-min period of infusion. Tumor control was scored as the absence of palpable growth at 100 days after treatment. RESULTS: Glucose infusion enhanced tumor control independent of temperature in the range 42-43 degrees C. At 42 degrees C, the TCD(50) for X-irradiation decreased by 5.9 Gy (SEM 1.8 Gy), from 41.6 (1.6) to 35.7 (1.5) Gy, and at 43 degrees C from 33.3 (1.6) to 27.3 (1.5) Gy, representing a glucose enhancement ratio of approximately 1.2. At doses corresponding to the TCD(50) at either 42 or 43 degrees C, the addition of glucose increased tumor control from 50% to 70%. An enhancement ratio of 2.1 was found for the combination of irradiation, glucose infusion, and heating at 43 degrees C, with respect to irradiation alone (TCD(50) 56.3 Gy, reanalyzed earlier data). The contribution of combined heat and glucose to tumor control represented an additive effect, probably on the hypoxic cell population. CONCLUSION: Moderate glucose administration (blood concentration 300 mg/100 mL) sizably improves experimental tumor control after combined X-irradiation and hyperthermia under clinically feasible conditions. Clinical treatment should benefit from this additional modality, in particular if unsatisfactory local control rates are due to insufficient heating. The therapeutic gain has to be evaluated further in clinical studies.


Assuntos
Glicemia/metabolismo , Glucose/farmacologia , Hipertermia Induzida , Rabdomiossarcoma/terapia , Animais , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Feminino , Concentração de Íons de Hidrogênio , Infusões Intravenosas , Modelos Logísticos , Ratos , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/radioterapia
19.
Int J Radiat Oncol Biol Phys ; 15(6): 1407-13, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2461920

RESUMO

Ninety-seven patients with breast cancer recurring in a previously irradiated area (mean dose 44 Gy) were reirradiated in combination with hyperthermia and had evaluable tumor responses. In the reirradiation series, radiotherapy was given twice weekly in most patients, with a fraction size varying from 200 to 400 cGy, the total dose varying from 8 to 32 Gy. Hyperthermia was given following the radiotherapy fractions. The combined treatment resulted in 35% complete and 55% partial responses. Duration of response was median 4 months for partial response and 26 months for complete response, respectively. The median survival time for all patients was 12 months. Acute skin reaction was mild, with more than moderate erythema in only 14/97 patients. Thermal burns occurred in 44/97 patients, generally at sites where pain sensation was decreased, and therefore they did not cause much inconvenience. In the 19 patients who survived more than 2 years, no late radiation damage was observed. When patients who received a "high dose" (greater than 29 Gy and hyperthermia) were compared with those who received a "low dose" (less than 29 Gy and hyperthermia), a higher complete response rate was observed in the high dose group (58% vs. 24%), whereas no difference in acute toxicity was found. We conclude that reirradiation with 8 x 4 Gy in combination with hyperthermia twice weekly is a safe, effective and well tolerated method for palliative treatment of patients with breast cancer recurring in previously irradiated areas.


Assuntos
Neoplasias da Mama/terapia , Hipertermia Induzida , Recidiva Local de Neoplasia/terapia , Cuidados Paliativos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/radioterapia , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/radioterapia
20.
Transplantation ; 55(4): 847-51, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8386405

RESUMO

CMV disease often recurs after initially successful antiviral therapy. We retrospectively determined in a group of 36 organ transplant patients whether clinical, virological, or immunological parameters during or shortly after cessation of antiviral therapy can identify those at high risk of relapse. Eleven of 36 patients had recurrent CMV disease after ganciclovir therapy. Neither donor or recipient CMV serostatus, type of baseline immunosuppression, antirejection treatment, indication for antiviral treatment, nor presence of CMV in the blood during or after therapy (as detected by antigenemia, viremia, or a positive polymerase-chain-reaction signal) were helpful in identification of patients with subsequent relapse. However, quantitative monitoring of antigenemia fascilitated early diagnosis of relapse since 10 of 11 patients with > or = 10 antigen-positive cells per 50,000 PMNs relapsed (99.1%, 95% CI 58.7-99.8). IgM and IgG responses against CMV during primary infection were comparable in relapsing and nonrelapsing patients. During secondary infection relapse occurred only in the 4 patients with the lowest IgG responses. The number of activated CD8bright lymphocytes in the peripheral blood as determined by flow cytometry at the end of antiviral therapy was a strong risk factor for the subsequent clinical course: 6 of 7 patients (85.7%, 95% CI 42.1-99.6%) with < 100 x 10(3) HLADR+CD8bright cells/ml blood relapsed, while 8 of 8 (100%, 95% CI 63-100) with activated CD8bright cells above that level remained asymptomatic (P < .025). These data show that patients with a high risk of relapse of CMV disease can be identified at the end of antiviral therapy.


Assuntos
Infecções por Citomegalovirus/epidemiologia , Ganciclovir/uso terapêutico , Transplante de Rim/efeitos adversos , Transplante de Fígado/efeitos adversos , Formação de Anticorpos , Antígenos Virais/sangue , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/etiologia , Humanos , Imunoglobulina M/imunologia , Transplante de Rim/imunologia , Transplante de Fígado/imunologia , Subpopulações de Linfócitos/imunologia , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Fatores de Risco
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