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Biomedical subjects

A Pica

Publications and source records attributed to A Pica.

27 records · Page 2Linked to original sources
PubMed1996

[Treatment of eyelid carcinomas of 2 cmm or less by contact radiotherapy].

PURPOSE: Analysis of a series of 50 patients treated by contact x-ray for an eyelid carcinoma. METHODS: From 1980 to 1991, a series of 50 patients with 52 lesions has been included in a protocol of contact x ray for eyelid carcinoma. Median age: 69 years; male: 25; female: 25. Histological or cytological diagnosis showed: basocell carcinoma: 47; squamous cell carcinoma: 5. The site was: lower eyelid; 31, inner canther: 10; outer canther: 5; upper eyelid: 6. Stade was (UICC 1987): T1 (< or = 2 cm): 44; post excision: 8. Treatment was performed on an ambulatory basis with the PHILIPS RT 50 x-ray contact machine (50 KV - 0.5 mm A1). The diameter of the localized was 10 mm: 22; 15 or 20 mm: 30. The standard treatment delivered 42 Gy/7 fractions/4 weeks (1 or 2 fractions of 6 Gy for week). RESULTS: There was no death due to cancer. A complete response was seen 2 months after the end of treatment in 43/44 cases. A long-term local control was obtained in 47 patients. Loss of eyelash was seen in the irradiated area with a supple and no necroses of the tarsal cartilage. The irradiated skin is slightly depigmented. Stenoses of the lower lacrimal duct is unusual and was seen only if it was in the field of irradiation. No cataract was observed. The cosmetic and functional results appeared excellent in the large majority of patients. One local relapse occurred in the irradiated area and two just outside the irradiated area. These 3 relapses were salvaged, two by surgical excision and one by a subsequent irradiation. CONCLUSION: Contact x-ray is a simple technique which requires no hospitalization, neither general anesthesia. It gives excellent local control and good cosmetic results in these small eyelid carcinomas.

Adult↗
PubMed1994

Radiotherapy in early stage Hodgkin's disease.

Ninety-nine patients with "standard risk" Stage IA-IIA Hodgkin's disease observed between January 1983 and December 1990, received radiotherapy only. The complete response rate was 98% (97/99). Twenty-one patients (21%) relapsed, 17 of whom (81%) obtained a second complete remission. The projected 9-year overall survival and disease-free survival were 95% and 78%, respectively. In this study our goals were to reduce the irradiation volumes, to decrease the number of splenectomies performed at diagnosis, and to utilize radiotherapy alone in these patients. We were able to reduce the irradiation volumes in over 50% and 80% of the patients with disease in the upper torso and subdiaphragm, respectively. Furthermore, this therapeutic approach permitted us to reduce the acute and long-term toxic effects related to splenectomy and combined modality treatment.

Adolescent↗
PubMed1994

[In vivo dosimetry and radiographic confirmation in radiotherapy of Hodgkin's lymphoma].

In September 1991 a protocol for quality control of large shaped irradiation fields was started in our department. In vivo dosimetry with semiconductor detectors was used to measure the absorbed dose and patient positioning was checked with portal films weekly. First, we set a computed dosimetric system yielding dosimetric values in real time and allowing their easy storage. Then, we calibrated the diodes and determined the correction factors for each of them outside standard conditions. Entrance dose, exit dose and midline dose were measured in 62 patients undergoing supradiaphragmatic radiation therapy for Hodgkin's lymphoma. The exist dose was measured weekly to assess treatment repeatability. High agreement was observed between measured and calculated doses; repeatability was also high, since only 6% of exit dose measurements exceeded 5% of the first determination. In 33 patients portal films were obtained in the first treatment session, and thereafter weekly, to assess mispositioning relative to simulation (reproducibility) and from one session to another (repeatability). A small systematic error was detected in both longitudinal (x = -3 mm; SD = 3.7 mm) and transverse (x = -2 mm; SD = 3.4 mm) directions. Statistically significant errors (> 6 mm) were observed in 14% of patients. Reproducibility was excellent. The protocol reported on in this paper not only helps avoid systematic dosimetric and/or positioning errors in the patients, but also helps identify the main causes of uncertainty and thus remove them.

Hodgkin Disease↗
PubMed1983

Cytochemical identification of the leukocytes of torpedoes (Torpedo marmorata Risso and Torpedo ocellata Rafinisque).

The authors subjected peripheral blood smears of Torpedoes to cytochemical analysis of lipids, protein, neutral and acid polysaccahrides and of some enzymatic activities, i.e. adenosine triphosphatase (ATP-ase), acid and alkaline phosphatase, aliesterase and peroxidase. It was found that neutrophilic granulocytes are intensely PAS and aliesterase positive and weakly ATP-ase positive. Eosinophilic granulocytes show the presence of neutral polysaccharides in the matrix (which is PAS positive) and strong ATP-ase and acid phosphatase activities in the granules. Lymphocytes sometimes contain weakly PAS and aliesterase positive granules. Monocytes show some small PAS positive granules and weak acid phosphatase and aliesterase activities. Thrombocytes contain some peripheral granules which are PAS positive and slightly ATP-ase positive. There are no transitional forms between the various cellular types. The results confirm the classification of leukocytes of Torpedoes into neutrophilic granulocytes, eosinophilic granulocytes, lymphocytes, monocytes and thrombocytes and contribute some informations about the histoenzymatic content of Elasmobranch leukocytes.

Animals↗
PubMedDate not supplied

Effects of thyroid hormones on heart and kidney functions.

Thyroid hormones affect the functions of several organs including the heart and kidney. Using isolated left papillary muscles we have investigated the action of thyroid hormones on the mechanical and electrical properties of the heart. We found that pure hypothyroidism causes a depression in contractile and electrical parameters, but we noticed that superimposed hypoparathyroidism accounts for the marked prolongation in contractile kinetics and action potential duration. At kidney level we have shown that thyroid hormones affect proximal tubular sodium transport and this effect is only partially mediated by the action of thyroid hormones on Na-K-ATPase activity. Using the micropuncture technique, we hypothesized that the early effect of thyroid hormone action is on the potassium permeability of proximal tubular cell membrane. This latter effect would explain the increase in isotonic fluid reabsorption through an increase in the driving force for sodium. Finally, hypothyroid patients have a decrease in glomerular filtration rate and renal plasma flow that are completely reversed by thyroxine administration. On the other hand, hyperthyroid subjects exhibit a significant increase in both parameters.

Animals↗
PubMedDate not supplied

Use of transgenic mice in acid-base balance studies.

The kidney is essential in maintaining body acid-base status. Recently, the use of transgenic mice has largely contributed to the understanding of the mechanisms involved. Important issues have been addressed in terms of the function of proteins or their regulation. In the proximal tubule, the role of Na+/HCO3-cotransport has been established, although further studies are needed to understand how its mutations lead to renal disease. Na+/H+ exchange has also been extensively studied, and its role in diuretic and natriuretic responses following an increase in blood pressure has been elucidated. The interaction of other transport proteins, such as the Na+/phosphate cotransporter NaPi II-a, with the Na+/H+ exchanger has also been investigated. In the medullary thick ascending limb of Henle's loop (MTAL), a role for NHE1 in transepithelial HCO3- absorption has been demonstrated: basolateral NHE1 controls the function of apical NHE3. As for the distal nephron, the majority of observations suggest that the regulation of H+-ATPase activity in response to acid-base status is mediated by the trafficking of pumps or pump sub-units, especially for the a4 subunit, rather than changes in subunit expression levels. Furthermore, the function of pendrin, a chloride/anion exchanger, has been assessed in response to changes in acid-base status. Important results have been obtained regarding the regulation of proximal tubule transport by several mechanisms, such as microvilli changes and the inducible and endothelial isoform of nitric oxide synthase (NOS). Finally, the interaction of chloride channels and potassium-chloride cotransporter with proton secretion has been evaluated. These findings highlight the importance of knockout animal models in studying kidney regulation of acid-base balance.

Acid-Base Equilibrium↗
PubMedDate not supplied

Morphology, origin and functions of the thrombocytes of Elasmobranchs.

Thrombocytes of Torpedo marmorata Risso and Scyliorhynus stellaris L. (Elasmobranchs) are multiform from rounded to spindle-shaped. They originate in the spleen from prothrombocytes. They appear to be functionally correspondent to mammalian platelets because they form aggregates and adhere to glass and contain the same surface-connected canalicular system (SCCS) as in platelets, as proved by tannic acid treatment. Immunocytochemical staining have demonstrated, moreover, the presence in their cytoplasm of three platelet factors: platelet factor 4, beta-thromboglobulin and factor VIII related antigen. Stimulating agent, like collagen, ADP, noradrenaline, 5-hydroxytriptamine and thrombin induce aggregation of thrombocytes and the empting of their granules and vesicles containing very likely the platelet factors. The above observations leave few doubts on the functional equivalence of elasmobranch thrombocytes to mammalian platelets.

Animals↗
PubMedDate not supplied

A study of the bone marrow precursors and hemoglobin of the blood cells of the red-legged partridge (Alectoris rufa rufa L.).

The hematological characteristics of the red-legged partridge are reported. In addition to morphological observations of the circulating blood cells, a hemoglobin (Hb) analysis and cytochemical and ultrastructural observations of the circulating blood cells and their precursors in the bone marrow are presented. Two types of Hb, major and minor, were found. Hemoglobin electrophoresis revealed that they were composed of three different globin chains. On direct examination of the peripheral blood smear, red cells (2.36 x 10(6)/mm3), including 1-3% erythroblasts and rare stem cells; leukocytes (21,000/mm3), and thrombocytes (20-30,000/mm3) were identified. The WBC differential count was: heterophils, 40-70%; basophils, 1-8%; eosinophils, 0-6% %; lymphocytes, 16-50%; and monocytes, 4-11%. On further testing, the heterophilic leukocytes stained with PAS and demonstrated positive reactions for ATPase, ACP, and LAP. Under TEM, their granules appeared elongated and were of uniform density. A crystalline core was not observed. In contrast, the eosinophils contained round granules. B and T lymphocytes were distinguished. The former were identified by the presence of mIgM, the latter by their capacity to form E-rosettes and by the presence of ACP and ALE. Under TEM, the T cells were observed to have microvilli; rare, small granules, and vacuoles. Immunocytochemical techniques were used to identify three platelet factors in the thrombocytes: PF4, FVIIIRAg, and beta-TG.

Animals↗