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Biomedical subjects

M Lapes

Publications and source records attributed to M Lapes.

10 recordsLinked to original sources
PubMed1999

Technical aspects of microwave thermotherapy.

We describe our new technical results dealing with microwave thermotherapy (hyperthermia) in cancer treatment, see Refs. [S.B. Field, C. Franconi (Eds.), Physics and technology of hyperthermia, NATO Seminar Proceedings, Urbino, Italy, 1986; J. Hand, J.R. James (Eds.), Physical Techniques in Clinical Hyperthermia, Wiley, New York, 1986; J. Vrba, M. Lapes, Microwave Applicators for Medical Purposes, CTU Press, 1996, in Czech; J. Vrba, C. Franconi, M. Lapes, Theoretical limits for the penetration depth of the intracavitary applicators, International Journal of Hyperthermia, 12:6 (1996) 737-742; C. Franconi, J. Vrba, F. Montecchia, 27 MHz hybrid evanescent-mode applicators with flexible heating field for deep and safe subcutaneous hyperthermia, International Journal of Hyperthermia, 9:5 (1993) 655-674.]. Our research interest is to develop applicators for deep local heating and for intracavitary cancer and/or prostate treatment as well. Further, a system for 3D SAR distribution measurements in water phantom is explained. Basic evaluation of clinical results is given.

Equipment Design↗
PubMed1997

[Treatment of early stages of ovarian carcinoma. Evaluation of experience at the Institute of Radiation Oncology over a 10-year period (1983-1993)].

The authors evaluated in a retrospective study the therapeutic results of ovarian carcinoma stage FIGO I (68 patients) and FIGO II (28 patients) attained in the Institute of Radiation Oncology, Prague during the ten-year period from 1983-1993. Total survival and survival without relapse within five years are 77% in stage I and 74% in stage II. The corresponding values of five-year survival without relapse were 56% and 58% resp. Despite the fact that the therapeutic results are comparable with data in the literature, a great shortcoming is the inadequate documentation of the initial laparotomy and the very general histopathological finding, moreover without grading, in a great proportion of the patients. The authors emphasize that these shortcomings make a reliable indication of adjuvant therapy impossible, in particular in early stages of ovarian carcinoma. Despite repeated references to this shortcoming these mistakes have persisted for several decades.

Adult↗
PubMed1996

Photodynamic therapy of cutaneous metastases of breast cancer after local application of meso-tetra-(para-sulphophenyl)-porphin (TPPS4).

Nine patients with cutaneous metastases of breast cancer were treated using photodynamic therapy. Meso-tetra-(para-sulphophenyl)-porphin (TPPS4) was applied locally at a dose of 0.15-0.3 mg directly to the lesion. The light source was an argon dye laser emitting light of 630 nm at a fluence rate of 312-680 mW cm-2 and a fluence of 150 J cm-2. No signs of local or systemic side effects or toxicity of the photosensitizer were observed. Treatments were well tolerated with no photosensitivity of the skin. Complete destruction of the tumour was observed in three patients, reduction of the tumour size by more than 50% in two patients, reduction-of the tumour size by less than 50% in two patients and no regression in two patients. The advantages of this method include the high concentration of the photosensitizer in the tumour, the extremely low total dose and the lack of side effects. The disadvantages include the less homogeneous distribution of the photosensitizer in the tumour tissue compared with that obtained by intravenous application.

Aged↗
PubMed1977

Familial testicular cancer in a father (bilateral seminoma-embryonal cell carcinoma) and son (teratocarcinoma): a case report and review of the literature.

Familial testicular neoplasia is reported in a father and his son. This represents only the fifth published case of father-son testicular cancer. The father had bilateral testicular seminoma with embryonal cell elements while the son had teratocarcinoma. The clinical significance of familial testicular neoplasia is discussed and the subject of father and son testicular cancer is reviewed. This case of father-son testicular neoplasia illustrates the following important points: 1) there is a continuing need to document and describe each case of familial testicular cancer in order to better evaluate the pathogenesis of this familial occurrence; 2) prospective genetic and laboratory studies will be needed to definitively clarify the specific factors involved in the familial clustering or transmission of this type of cancer; and 3) this tendency for testicular cancer to affect multiple kindred must be considered in the proper guidance and counseling of affected patients and their high-risk family members.

Adult↗
PubMed1977

Cellular and humoral immunity in non-Hodgkin's lymphoma: correlation of immunodeficiencies with clinicopathologic factors.

Immune function was evaluated in 28 non-Hodgkin's lymphoma patients in an attempt to correlate the occurrence of immunodeficiency with the prognostic clinicopathologic factors, lymph-node histology, and clinical stage of disease. Anergy to a battery of recall antigens occurred infrequently (4/28) and only in patients who had Stage IV disease (4/8) (p = less than .004), but did not correlate with lymph-node histology. In contrast to anergy, cellular immunodeficiencies were often detected by lack of response to keyhole limpet hemocyanin immunization in patients regardless of stage. Reductions in at least two of three Ig fractions were found in a third of the patients, with, again, a significantly greater incidence in Stage IV patients (p = less than .005). No significant correlation with histologic type was possible. The response to phytohemagglutinin in vitro was reduced in the patients, but this was of no correlative value.

Antigens↗
PubMed1976

Conversion of a benign lymphoepithelial salivary gland lesion to lymphocytic lymphoma during dilantin therapy: correlation with dilantin-induced lymphocyte transformation in vitro.

A patient with a classical salivary gland benign lymphoepithelial lesion (BLL) that converted to a lymphoblastic lymphoma (LSA) localized to the salivary glands is described. The malignant transformation of the BLL was preceded by Dilantin anticonvulsant therapy, and in vitro tests subsequent to the development of LSA demonstrated positive Dilantin-induced lymphocyte transformation. The lymphoma was treated successfully by local irradiation, chemotherapy, and discontinuation of Dilantin. The case illustrates the "prelymphomatous" nature of BLL in certain patients, as well as the possible potential danger of Dilantin and other lymphoid-stimulating drugs in discussed. Further study of drugs capable lymphocyte transformation in patients with prelymphomatous disorders is warranted.

Cell Transformation, Neoplastic↗
PubMedDate not supplied

Theoretical limits for the penetration depth of intracavitary applicators.

We present an approximated analytical model for calculating the attenuation features of the wavefront power density, or SAR, for linear radiators inside a coaxial cylindrical cavity in both non-lossy and lossy tissues. The results are evidencing the determinant role of the cavity radius in affecting the SAR radial decay and the associated penetration depth. A further explicit finding is that the upper limit for the penetration depth in endocavitary radiative heating is equal to the cavity radius, a limit of general validity which holds in both lossy and non-lossy media for any radius value, and is not affected by the approximated nature of the model. Thus, a simple exponential equation allows a straightforward predictive evaluation of both the penetration depth intrinsic upper limit and the approximate penetration depth values, with only the knowledge of the cavity radius and the operating frequency required, without the need to refer to time-consuming electromagnetic field calculations.

Humans↗