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Biomedical subjects

A Beorchia

Publications and source records attributed to A Beorchia.

15 recordsLinked to original sources
PubMed1991

An afterloading technique suitable for carcinomas of the oral cavity.

The authors describe an afterloading brachytherapy to treat oral cavity carcinomas. Catheters for arterial/venous catheterization are inserted percutaneously in the target volume. The internal needles are then removed and replaced with iridium wires inside tubes to form wire loops. This technique has proven to be simple, quick and safe.

Brachytherapy↗
PubMed1991

Three-dimensional imaging of the mucus secretory process in the cryofixed frog respiratory epithelium.

Using the frog palate as a representative model of human mucociliary epithelium, we analyzed, after quick freezing fixation, the three-dimensional (3-D) respiratory mucus secretory release with high voltage (200-300 kV) transmission electron microscopy (TEM). The 3-D vision of the mucus release from the secretory cells was obtained as stereo-pairs and "bas-relief" images after analysis of stereo-pairs using an image analyzer. After standard glutaraldehyde fixation, the secretory cells showed a typical goblet shape with secretory granules heterogeneous in size and electron-density which often fuse together. On the other hand, quick-frozen secretory cells exhibited a columnar shape and their membrane-bound secretory granules contained a homogeneously dark matrix. The expanded gel mucus layer was preserved and its depth never exceeded 2 microns. When the epithelium was immersed in culture medium in presence of cholinergic agonist, a marked discharge of mucus was observed and the granules swelled at the apex of the secretory cell before being discharged in the lumen. In native cryofixed epithelium, the secretory granules exhibited a marked deformability during the process of their extrusion from the secretory cell. Clusters of secretory granules surrounded by cytoplasmic material were observed in the extracellular lumen, suggesting an apocrine-type secretion. These observations indicate that rapid cryofixation and 3-D stereoscopic imaging enable a unique opportunity to analyze, without artifact, the mucous secretory process. We speculate that, apart from the classical merocrine-type secretion mechanism, the respiratory mucus may be released, at least partly by an apocrine-type secretion.

Animals↗
PubMed1991

Digital three-dimensional visualization of cellular organelles studied by medium- and high-voltage electron microscopy.

Tilted thick sections (one-half to several micrometers) of biological specimens observed with medium- to high-voltage electron microscopes are extremely useful for the study of the three-dimensional (3-D) structure of organelles. If high resolution in 3-D visualization and 3-D reconstruction is needed, many images corresponding to various angles of rotation and tilt must be recorded. This necessitates very time-consuming work--including eventual photographic processing--before good positioning of the object is defined. We have developed software which permits very rapid and precise determination of the tilt-axis, the registration of tilted views, 3-D measurements and 3-D visualization. Images are digitized either from negative films or directly with a camera fitted to the microscope. The application of the software is performed in minutes and allows for a rapid check of the quality of the tilt-series and of the features of interest of the object. Application of the software to the study of the 3-D structure of active components of the nucleolus stained with silver is shown.

Cell Nucleolus↗
PubMed1991

[Influence of radiotherapy on lymphocyte subpopulations].

The authors investigated the effects of radiation therapy on the immune system by studying lymphocyte subsets and other parameters in 32 patients undergoing radiation therapy for solid cancer. With monoclonal antibody techniques, we studied both T- and B-lymphocytes; cell suspensions were analyzed by means of a Facs Spectrum III Ortho (Ortho-Diagnostic) unit. The first control was performed right after the beginning of radiotherapy, when the dose to the patients was 50 Gy or higher. The second control was performed at 40 Gy because all patients received this dose. 30% of the patients exhibited lymphopenia from the beginning of the study; at 40 Gy the number of T-lymphocytes was low and helper/suppressor ratio was altered. A variable response of B-cells was observed, although all patients exhibited restoration of normal values at 6 months. Four patients only suffered from side-effects: a patient with tongue cancer presented oral mycosis, and a woman--treated for breast cancer--presented vaginal mycosis. Two cases of cystitis were also observed, after 18 Gy, in patients with uterine carcinoma undergoing pelvic irradiation. Disease progression was observed in 2 patients with head and neck cancer, while 3 patients died from lung cancer progression. Another one, with head and neck cancer, died because of heart failure.

Adult↗
PubMed1990

[Role of accelerated electrons in the therapy of advanced-stage skin epithelioma advanced stage: analysis of 31 cases].

Electron beam therapy is the superior modality of treatment for advanced skin cancer or in specific anatomical situations. The authors report the results for the electron beam therapy of 31 patients with advanced skin carcinoma. There were 15 squamous cell carcinomas, 11 basal cell carcinomas and 5 mixed, basosquamous cell carcinomas. All lesions were 3 cm or greater in maximum diameter. With follow-up ranging from 1 to 6 years, 28 patients have not evidence of disease, 1 is dead with disease, 1 is alive with suspicious residual disease and 1 is alive with recurrence. Acute and late complications are acceptable; bone, cartilage and soft tissue necrosis are not reported. The treatment results are similar to those in the literature and show the advantages of the electron beam irradiation for advanced skin carcinomas.

Aged↗
PubMed1990

[The treatment of cancer of the anal area with radiotherapy. An analysis of the authors' personal experience].

The treatment of anal canal carcinoma is very difficult and great care must be taken in planning therapy because this type of cancer is potentially curable. From 1982 through 1989 we treated 16 patients with carcinoma of the anal canal. All patients were evaluable for toxicity and 14/16 for response after treatment. Of the 12 patients who underwent irradiation alone and were N0 M0, 8 are alive with no evidence of the disease, 4 had a recurrence which was treated with radical surgery, and 2 underwent palliative treatment alone. Therapy toxicity was not relevant in most cases and our results are in agreement with those reported in the literature.

Adenocarcinoma↗
PubMed1989

A new technique for endocavitary irradiation of the esophagus.

Recently, high-dose rate intracavitary irradiation has been used as a boost therapy or a palliative therapy in the treatment of the esophageal carcinoma. The new intraesophageal device is based on a modified Sengstaken-Blackemore tube. On the surface of the esophageal balloon of the S-B tube Cyponil tubes are fixed as iridium containers. The device is placed at the level of the neoplastic lesion. Treatment tolerance is good.

Brachytherapy↗
PubMed1989

[Templates for curietherapy of the oral cavity and their dosimetric use].

Flexible 192Ir wire implants are commonly used for the treatment of some types of cancer in the oral cavity. A modified technique of plastic tubes is here presented which aims at correctly positioning the active wires with thin plastic templates. Possible sources of error are examined and their consequences on the dose distribution around the implant are analyzed. In most cases control dosimetry matches the provisions satisfactorily. It may be thus concluded that the use of templates allows good and reproducible results to be obtained in the brachytherapy of the oral cavity.

Brachytherapy↗
PubMed1987

The three-dimensional ultrastructure of interphasic and metaphasic nucleolar argyrophilic components studied with high-voltage electron microscopy in thick sections.

The three-dimensional structure of the nucleolar argyrophilic components was studied by recording stereo-pairs of tilted thick sections--0.5-2 microns thick--observed with 200 and 300 kV high-voltage electron microscopy (HVEM). Using a very specific silver staining method, the argyrophilic components were stained with a high contrast relatively to the unstained background, thus allowing their study with a high resolution within thick sections. This study was performed on compact nucleoli (of HL60 and K562 cells), on reticulated nucleoli (of human breast cancerous cells) and on metaphasic nucleolar organizer regions (NORs). In compact nucleoli argyrophilic components show a 'knotted rope-like' structure in which knots are constituted of one central fibrillar centre surrounded at some distance by loops of the dense fibrillar component and in which the rope is constituted of dense fibrillar component. In reticulated nucleoli silver deposits are confined to the surface of the nucleolonema as several strands twisted at the periphery of the fibrillar component. During metaphase some NORs get a characteristic crescent-shaped structure disposed at the periphery of some chromosomes.

Breast Neoplasms↗