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1.
Mech Ageing Dev ; 4(3-4): 231-9, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1081633

RESUMO

The effect of different immunosuppressive treatments during young adulthood or humoral immune competence late in life was determined. It was found that the marked reduction in humoral immune competence in aged mice is further compromised when severe insults are administered early in life. Thus, thymectomy, splenectomy, and sublethal X-irradiation produced lasting immunodepression as measured (1) in situ and (2) by the hemolysin, direct and indirect plaque forming cell responses of adoptively transferred spleen cells. In contrast, treatment with cyclophosphamide and cortisone acetate were without effect, indicating that drug-damaged cells of the immune system were replaced by competent cells during the course of time. Decrease in immune competence of aged thymectomized animals could not be correlated with a decrease in numbers of theta-bearing T or immunoglobulin receptor-bearing B lymphocytes. The significance of the observed unequal effects of these immunosuppressants on immune competence, as they relate to disease incidence and life expectancy, are dealt with in the third paper in this series.


Assuntos
Formação de Anticorpos/efeitos dos fármacos , Cortisona/farmacologia , Ciclofosfamida/farmacologia , Terapia de Imunossupressão , Longevidade/efeitos dos fármacos , Fatores Etários , Animais , Formação de Anticorpos/efeitos da radiação , Linfócitos B/imunologia , Feminino , Proteínas Hemolisinas/análise , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/efeitos da radiação , Longevidade/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos , Lesões Experimentais por Radiação/imunologia , Esplenectomia , Linfócitos T/imunologia , Timectomia
2.
Adv Exp Med Biol ; 157: 43-8, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-7158523

RESUMO

A versatile hyperthermia control system, based on a microcomputer, provides automated temperature regulation (1 channel) and monitoring (3 channels) and control of microwave output (both on/off and power level), and displays temperature (degree C) and microwave output (watts) graphically in real time; all data are stored on floppy diskette.


Assuntos
Computadores , Temperatura Alta/uso terapêutico , Microcomputadores , Neoplasias/terapia , Humanos , Micro-Ondas/uso terapêutico
3.
Med Instrum ; 21(2): 75-80, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3614034

RESUMO

Hyperthermia, the intentional elevation of tissue temperature above 41 degrees C, is being intensely researched as a therapeutic modality for cancer, especially when used in combination with radiation therapy and/or chemotherapy. A serious impediment to laboratory progress in this area has been the lack of affordable equipment providing control and reproducibility when faced with highly variable factors including tumor size and shape, blood flow, heat conduction, and tissue dielectric discontinuity. Our solution has been the development of a laboratory microwave hyperthermia system, dedicated to the treatment of small, superficial tumors. This system uses a 2.45-GHz microwave generator and custom applicator to noninvasively heat a mass of tissue about 2 cm in diameter and 1.5 cm in depth. Tissue temperature at up to four locations is measured using miniature. Teflonencased thermocouples. The microwave generator and the thermometry are interfaced to a personal computer which provides fully automated hyperthermia treatment reproducible to +/- 0.2 degrees C.


Assuntos
Animais de Laboratório , Hipertermia Induzida/instrumentação , Neoplasias Experimentais/terapia , Animais , Hipertermia Induzida/métodos
4.
NCI Monogr ; (6): 147-53, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3352758

RESUMO

The interaction of doxorubicin and radiation has been systematically studied in the Dunning R3327G prostatic adenocarcinoma, the preeminent animal model for human prostatic cancer. Subcutaneous tumors (produced by injection of 10(7) cells) were treated when about 1 cm3 in volume (19-22 days postimplant). Each modality was used at 1 of 3 dose levels; 2, 4, and 9 mg/kg for doxorubicin; and 5, 15, and 25 Gy for radiation. Single treatment with each agent was combined, in both sequences and five delay times (0.5, 12, 24, 48, and 120 hr) between agents. Growth of individual tumors was fit to a quadratic exponential growth model which was solved for the growth delay and growth rate at twice initial volume. Analysis of variance identified significant interactions for doxorubicin and radiation (due to drug toxicity), sequence and delay, and sequence and radiation, in addition to the four factors individually. The effect on the tumor of combined doxorubicin and radiation is basically additive. Sequence and delay are important in overall tumor control.


Assuntos
Adenocarcinoma/terapia , Doxorrubicina/uso terapêutico , Neoplasias da Próstata/terapia , Animais , Terapia Combinada , Masculino , Dosagem Radioterapêutica , Ratos
5.
Radiology ; 169(1): 243-7, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3420266

RESUMO

The interaction of radiation and hyperthermia was systematically studied in the Dunning R3327G prostatic adenocarcinoma, the preeminent animal model for human prostatic cancer. Subcutaneous tumors (produced by injection of 10(7) cells) were treated when they had reached a volume of about 1 cm3, which occurred about 3 weeks after implantation. With the use of a randomized complete factorial design, four factors were examined. Each agent was used at one of three dose levels. For radiation, these were 5, 15, and 25 Gy; for hyperthermia, 42 degrees C for 15 minutes, 43 degrees C for 30 minutes, and 44 degrees C for 60 minutes. Two sequences (hyperthermia plus irradiation and irradiation plus hyperthermia) and five time delays between agents (0, 12, 24, 48, and 120 hours) were used. The growth delay (the time it took for the initial tumor volume to double) of subcutaneously implanted tumor served to quantitate treatment effect. Significant (P less than .05) statistical interactions were observed for several combinations of factors and individual factors. Hyperthermia plus irradiation was more effective than irradiation plus hyperthermia except at the delay time between treatments of 0 hours. Peak growth delay occurred when the time between treatments was 0-24 hours and depended on agent doses. Many combinations produced therapeutic synergy.


Assuntos
Adenocarcinoma/terapia , Radioisótopos de Cobalto/uso terapêutico , Hipertermia Induzida , Neoplasias da Próstata/terapia , Teleterapia por Radioisótopo , Adenocarcinoma/radioterapia , Animais , Terapia Combinada , Masculino , Micro-Ondas/uso terapêutico , Neoplasias da Próstata/radioterapia , Distribuição Aleatória , Ratos
6.
J Oral Maxillofac Surg ; 45(1): 34-41, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3540238

RESUMO

Healing of cellular bone grafts irradiated at various times in the postsurgical course was compared to the healing characteristics of bone grafts placed into already irradiated tissue and to controls of irradiated host mandible in a rabbit model. Physical graft consolidation was assessed by load stress characteristics and serial histologic examination. Results indicated that grafts placed into already irradiated tissues failed to form bone in both phases of expected regeneration resulting in structurally weakened and histologically deficient ossicles. Bone grafts irradiated after placement were tolerant of irradiation. Bone grafts irradiated after four weeks were found to be less affected by irradiation than those irradiated within the first four weeks, forming an ossicle structurally and histologically superior to that of bone ossicles developed from grafts placed into irradiated tissues.


Assuntos
Transplante Ósseo , Mandíbula/efeitos da radiação , Animais , Regeneração Óssea/efeitos da radiação , Radioisótopos de Cobalto , Masculino , Mandíbula/anatomia & histologia , Mandíbula/cirurgia , Cuidados Pós-Operatórios , Cuidados Pré-Operatórios , Coelhos , Estresse Mecânico , Fatores de Tempo , Cicatrização
7.
Rev Interam Radiol ; 6(1): 7-10, 1981 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7209284

RESUMO

Hyperthermia is the artificial elevation of tissue temperature above 41 degrees C with therapeutic intent. Most of the currently used hyperthermia units lack feedback temperature control mechanisms, and, therefore, are not optimal for clinical trials. To solve this problem, we have developed a control system based on a microcomputer. The computer measures the tumor and normal tissue temperature using fine thermocouple sensors and regulates the output of the microwave generator to achieve and maintain the prescribed tumor temperature under specified conditions. Safety procedures are incorporated to avoid heating the tumor or normal tissue beyond predetermined limits.


Assuntos
Computadores , Hipertermia Induzida/instrumentação , Micro-Ondas/uso terapêutico , Neoplasias/terapia , Humanos
8.
Int J Hyperthermia ; 7(3): 485-92, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1919143

RESUMO

The SAR patterns were determined for four commercially available microwave (915 MHz) interstitial applicators. Values of SAR were determined using a miniature (3 mm diameter) implantable isotropic electric field probe or a custom 0.25 mm diameter fluoroptic temperature probe. These are the smallest such probes that are currently available. Similar radial variation of SAR was found at the axial position of the gap in the outer conductor for each applicator. Electric field probe measurements are much faster and avoid some of the errors caused by the rapid spatial variation of SAR with interstitial applicators. The major limitation on the electric field probe is its size; it is larger than the applicators being tested.


Assuntos
Hipertermia Induzida/instrumentação , Micro-Ondas/uso terapêutico , Termômetros , Eletrônica Médica , Estudos de Avaliação como Assunto , Humanos , Modelos Estruturais , Neoplasias/terapia , Temperatura
9.
Gynecol Oncol ; 43(1): 29-36, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1959784

RESUMO

The treatment of ovarian carcinoma includes maximum surgical removal of the tumor tissue followed by irradiation or chemotherapy. In this study, the effects of caffeine on cell cycle traverse have been studied over a 168-hr period after X irradiation in BG-1 cells, an ovarian carcinoma cell line. The results were obtained with dual-parameter flow cytometric measurements of DNA and nuclear protein, using propidium iodide and fluorescein isothiocyanate. After radiation alone, a dose-related arrest of cells in G2 phase and cell kill were observed. Irradiating BG-1 cells with 5 Gy produced an accumulation of the cells in G2 at 24-72 hr postirradiation. When G2 was divided into low nuclear protein (G2A) and high nuclear protein (G2B) compartments, there was a G2A peak accumulation at 24 hr and a G2B peak accumulation at 48-72 hr. The addition of 1 mM caffeine to the culture media, starting immediately postirradiation, prevented G2 arrest, promoting a rapid traverse of cells through G2A to G2B to G1, which was associated with diminished survival.


Assuntos
Cafeína/farmacologia , Neoplasias Ovarianas/patologia , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Terapia Combinada , DNA de Neoplasias/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Relação Dose-Resposta a Droga , Feminino , Citometria de Fluxo , Fase G2/efeitos dos fármacos , Fase G2/efeitos da radiação , Humanos , Proteínas Nucleares/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/radioterapia , Fase S/efeitos da radiação , Fatores de Tempo , Células Tumorais Cultivadas
10.
Int J Hyperthermia ; 6(3): 707-14, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2376681

RESUMO

Using microscopic techniques we have fabricated interstitial hyperthermia applicators having diameters of 0.20, 0.33 and 0.58 mm, which will fit through catheters of 30, 26 and 22 gauge, respectively. Existing commercial applicators having a diameter of 1.1 mm required 17 gauge (or larger) catheters. Our new applicators, which operate at 915 MHz, are a smaller version of a design used by others. We have characterized our applicators by determining the energy deposition patterns (SAR) in muscle-simulating phantoms. These patterns were determined by measuring the electric field intensity using a miniature implantable isotropic probe having a diameter of 3 mm. Contours of the SAR data for our applicators, as well as a larger commercial applicator, show that all of these applicators exhibit similar heating patterns. Test results suggest that the durability and power handling capability of our submillimetre applicators are adequate for use in patients. Our new applicators should be useful in the percutaneous treatment of deep-seated tumours, intraoperative treatments, and also permit intraluminal or intravascular access to tumours.


Assuntos
Temperatura Alta/uso terapêutico , Micro-Ondas/uso terapêutico , Engenharia Biomédica , Fenômenos Biofísicos , Biofísica , Cateterismo , Humanos , Modelos Anatômicos , Neoplasias/terapia
11.
Gynecol Oncol ; 46(1): 88-96, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1634145

RESUMO

Radiotherapy remains an important part of uterine cancer treatment. This study was designed to evaluate the potential of the ATP bioluminescence assay and flow cytometry for predicting radiosensitivity. Correlation of these two modalities revealed important insights into the relationship of radiotoxicity and cell kinetic effects. Six human uterine cancer cell lines were used: AE7, ECC1, HEC1A, HEC1B, AN3, and SKUT1B. Doses of cobalt 60 were 0, 1, 2, 5, 8, and 10 Gy. The ATP bioluminescence assays were performed on Day 7. Cell samples were taken at 0, 24, 48, 72, 96, and 168 hr for flow cytometry. The linear-quadratic model was used to fit survival data and mean inactivation dose D was calculated. Among parameters such as D, alpha and beta coefficients, and surviving fraction at 2 Gy (SF2), both D and SF2 correlated best with survival data. Radiation effects on the cell cycle did not correlate with D and revealed two distinct patterns: either a G1 accumulation with mild G2 block or a G1 depletion and severe G2 block. The S cells consistently demonstrated a biphasic pattern with an initial reduction followed by an accumulation. In summary, the ATP assay was shown to have potential in the study of radiosensitivity. Radiation-induced cell kinetics appeared to vary with intrinsic cellular differences and, thus, could not be used to predict radiosensitivity.


Assuntos
Ciclo Celular/efeitos da radiação , Neoplasias Uterinas/radioterapia , Trifosfato de Adenosina , Bioensaio , Divisão Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Citometria de Fluxo , Humanos , Medições Luminescentes , Tolerância a Radiação , Radioterapia/efeitos adversos , Células Tumorais Cultivadas , Neoplasias Uterinas/patologia
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