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Biomedical subjects

P C Duarte

Publications and source records attributed to P C Duarte.

9 recordsLinked to original sources
PubMed2002

Feline vaccine-associated fibrosarcoma: morphologic distinctions.

Forty-four primary feline vaccine-associated fibrosarcomas and 16 recurrences were examined histologically for detailed morphologic characterization with emphasis on tumor grade, presence of neoplastic multinucleated giant cells, presence and proportion of T and B lymphocytes within the tumor, and thin and intermediate filament contents of neoplastic and stromal cells. The microvascularity and proliferation rates of central and peripheral areas of the tumors were also quantified by computerized image analysis. For primary fibrosarcomas, 11 of 44 (25%) were grade I, 21 of 44 (47.7%) were grade II, and 12 of 44 (27.3%) were grade III. The recurrences followed a similar pattern: 4 of 16 (25%) were grade I, 8 of 16 (50%) were grade II, and 4 of 16 (25%) were grade III. A positive correlation was found between the presence of neoplastic multinucleated giant cells and tumor grade. These cells were present in 9 of 12 (75%) of grade III and none of the grade I tumors. Prominent peritumoral lymphoid aggregates or follicles were present in 59% of the tumors, and many contained high proportions of T lymphocytes, varying from 19 to 87%. All fibrosarcomas were immunoreactive for vimentin and 28 of 44 (64%) were reactive for alpha-smooth muscle actin. The actin-positive cells were either part of the tumor or formed a capsule around tumor nodules. The peripheral vascularity was significantly higher than the central vascular density but no difference was found in tumor cell proliferation rates between the two areas. Centrally located, fluid-filled micro- or macrocavitations were frequently observed in the large vaccine sarcomas and probably formed secondary to rapid tumor growth and central necrosis.

Animals↗
PubMed1998

[Comparison of epidemiological data on pulmonary tuberculosis in Sorocaba, Säo Paulo, Brazil, (1986-1996)].

Pulmonary tuberculosis is a serious public health problem in Brazil. Data were collected relating to the patients' health before diagnosis and also to the time lag between this diagnosis and the beginning of specific treatment over a period of three months. Fifty patients suffering from pulmonary tuberculosis were questioned about: symptomatology before diagnosis, lapse between the occurrence of the first symptoms and the beginning of treatment and relationship with AIDS. There had been no significant change in the time-lag between the time of discovery of new cases and the beginning of treatment, over the last ten years.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Microangiopathic hemolytic anemia. A form of presentation of stomach neoplasm].

The authors report the case of a 53-year-old female with symptomatic anemia and hemorrhagic diathesis. The patient presented thrombocytopenia, microangiopathic hemolytic anemia and leukoerythroblastic reaction in peripheral blood film. The diagnosis of metastatic gastric carcinoma was made by subsequent studies. A review is made of the literature concerning microangiopathic hemolytic anemia, namely its etiology, mechanisms of pathogenesis and association with metastatic carcinoma.

Adenocarcinoma↗
PubMed1994

[The cardiac toxicity of cancer chemotherapy].

The presence of secondary effects following the administration of chemotherapeutic drugs is an important limitation to cancer therapy. Of these, cardiotoxicity is of crucial importance due to its negative influence on survival. The anthracyclines and cyclophosphamide are the most important cardiotoxic antineoplastic agents currently used. If we agree on a ceiling dosage of chemotherapy we will deprive some patients with a highly functional cardiac reserve of a potential benefit in the control of their cancer. Other patients who are more susceptible to the cardiotoxic effects of anticancer agents will suffer from severe cardiac disfunction following small cumulative doses of anthracyclines. The authors discuss the main cardiotoxic effects of several antineoplastic drugs with special attention given to the anthracycline group. Several diagnostic methods potentially useful in cardiac monitoring are described. Radionuclide angiocardiography is considered the gold-standard in monitoring anthracycline cardiotoxicity. Other invasive methods like endomyocardial biopsy and right heart catheterization can be clinically useful when nuclear angiocardiography is inconclusive. The authors propose an approach to the prevention of anthracycline cardiotoxicity. Other chemotherapeutic agents like cyclophosphamide are associated with the presence of myopericarditis which is sometimes fatal. The cardiotoxic effects of anticancer treatment with 5-fluorouracil, mitoxantrone, carmustine, amsacrine and interferon are less frequent and usually more benign. Finally we discuss bone marrow transplantation and its related cardiotoxicity.

Antineoplastic Agents↗
PubMed1993

Systemic lupus erythematosus: sex hormones in male patients.

Systemic lupus erythematosus (SLE) is a rare disease in males. There is evidence that a functional state of hypoandrogenism is important in the pathogenesis of the disease. We analysed the levels of several hormones (follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), estradiol (E2), free estradiol (FE2) and prolactin (PRL)) in 17 male SLE patients and 17 male healthy controls with similar age distribution. Three lupus patients were excluded from the analysis due to previous cyclophosphamide therapy or pre-puberty. Thus 14 male lupus patients were eligible for the study. Six of the 14 SLE patients (43%) showed at least one abnormal level of FSH, LH or T. There were no abnormalities in these hormones in the 17 controls. This difference was significant (P < 0.01). In five of these 6 male patients (36% of all lupus patients) the hormonal profile was compatible with a functional state of hypoandrogenism (high LH and/or low T). The ratio E2/T (estradiol/testosterone:pmol/nmol) was also significantly higher in the SLE group (average = 6.5; SD 4.3) when compared with that of the control group (average 4.2; SD 1.2; Mann-Whitney rank sum test: P < 0.03). There were no significant differences in E2, FE2 or PRL between lupus patients and controls. We did not confirm the notion that left-handedness is frequent in male lupus as all our patients were right-handed. We found a significantly higher prevalence of sex hormone abnormalities in male lupus patients when compared with healthy controls with a similar age distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Essential thrombocythemia. Apropos a case of cerebrovascular stroke].

The authors report the case of a 60-year-old white man with a previous history of pulmonary tuberculosis, smoking habits, hypertension, intermittent claudication and erythromelalgia, admitted to our ward with an ischemic cerebral event. Initial laboratory evaluation documented thrombocytosis (platelet-950000/mm3) and discrete anemia. Additional studies confirmed the diagnosis of essential thrombocythemia, meeting all the criteria proposed by the Polycythemia Vera Study Group in 1986, after exclusion of the possible causes of reactive thrombocytosis. Therapy was initiated with alpha-2b interferon (3 MU/m2 subcutaneously three times a week) and aspirin. Platelet count control was obtained and the patient remained asymptomatic. Nine months later cutaneous toxicity obliged the discontinuance of alpha-interferon. Due to a continuous increase of platelet count, hydroxyurea was introduced. The patient is asymptomatic, with platelet counts < 500000/mm3, without toxicity manifestations, two years after diagnosis. The contribution of cardiovascular risk factors versus thrombocythemia in the pathogenesis of the ischemic cerebral event and the benefit of platelet count control are discussed.

Aspirin↗
PubMed1992

[Pulmonary embolism--mortality risk].

We conducted a retrospective analysis on 311 patients with clinical diagnosis of pulmonary embolism (PE) in a period of 3 years. 163 patients were excluded based on clinical-laboratorial criteria. The remaining 146 patients had a median age of 69 years (range: 30-91 years). 54% of the patients were male. We found dyspnea (94%), abnormal cardiopulmonary observation (89%), risk factors for venous thromboembolism (74%), tachycardia (53%), cyanosis (49%), and neck vein distension (45%) to be the most frequent findings. 64% of the patients had heart failure, 32% had myocardial ischemia, 13% had cancer, and 11% had myocardial infarction. Lactic dehydrogenase (LDH) was higher than two-fold in 54% of the patients. There was severe hypoxemia in 55% of the cases and hypocapnia in 43% of the cases. Creatinine phosphokinase (CPK) was elevated in 16% of the cases. Electrocardiography was suggestive of PE in 37% of the cases. Echocardiography showed right heart dysfunction in 30% of the cases, 92% of the patients were treated with heparin, 37 patients (25%) died, 54% of which during the first 4 days after admittance. Trying to define an index of mortality in PE we evaluated all patients by discriminant analysis coming up with 14 items with good discriminative power. By approximation of their odds-ratios we determined how many points would correspond to each item in the total sum.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Partial characterization of a liver serine-peptidase from different species which inactivates bradykinin.

Proteases which inactivate bradykinin were partially purified from the fresh exsanguinated liver of rat, man, dog, guinea-pig, chicken, frog and snake. The enzymes which are present in the soluble fraction of the liver homogenates, were prepared by DEAE-cellulose chromatography, in 0.025 M tris-HCl, pH 7.4. The peptidase activity was eluted with 0.09 M KCl; and further purification was achieved by gel-filtration in Sephadex G-150. The kininases are present in the same range of activity in all studied preparations, and final specific activities are also comparable. The molecular weight of the enzymes, as determined by gel filtration, are in the range of 70,000-100,000. All preparations were completely inhibited by 10 mM PMSF and 1 mM Tos-PheCh2Cl; 10 microM 2-mercaptoethanol, and 1 mM Tos-LysCH2Cl do not affect the enzymatic activity. The major site for the cleavage of bradykinin is the Phe5-Ser6 peptide bond. The serine-peptidase is found in the liver of all vertebrates so far studied.

Animals↗