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Biomedical subjects

P Fernandes

Publications and source records attributed to P Fernandes.

At least 55 records · Page 3Linked to original sources
PubMed1991

[High resolution electrocardiogram and late potential monitoring].

The signal-averaged ECG became an important noninvasive method for identifying life-threatening ventricular arrhythmias. It is most accurate in patients with coronary artery disease and can be helpful in predicting whether a patient with an unexplained syncope or nonsustained VT is at risk of developing sustained ventricular tachycardia or not. A patient with an entirely normal signal-averaged ECG is at very low risk of sustained VT. In contrast, an abnormal signal-averaged ECG should raise suspicion about VT, and prompt further studies, including electrophysiological testing. Signal-averaged ECG can also be used repeatedly with acceptable reproducibility. Technological advances and improvements in the frequency analysis of the averaged signal may increase the predictive accuracy of the technique and consequently enhance its clinical applications.

Electrocardiography↗
PubMed1989

Selected indices of micronutrient status in adult patients with sickle cell anemia (SCA).

In 24 adults with hemoglobin SS followed at the Duke University Comprehensive Sickle Cell Center, we have studied the following nutritional parameters: reduced ascorbic acid; dehydroascorbic acid; alpha and beta carotenes; cryptoxanthin; and alpha and gamma tocopherols in whole blood, washed red blood cells, plasma, or serum. In the same population we also examined reduced glutathione (GSH) and oxidized glutathione (GSSG). Fifteen of these 24 patients also were interviewed for usual dietary intakes using a 28-day dietary history. Data obtained from patients with hemoglobin SS, sickle cell anemia (SCA) were compared to those found for seven healthy normal black adults of similar age. Plasma alpha tocopherol levels were significantly lower in SCA individuals than those of the controls (P less than 0.004). Alpha and gamma tocopherol levels in sickle RBCs were significantly higher than those from RBC suspensions of control subjects (P less than 0.007, and P less than 0.001, respectively). All serum values for carotenoids examined, specifically, beta carotene, alpha carotene, and cryptoxanthin were also markedly depressed when compared to those of healthy controls (P less than 0.001, P less than 0.002, and P less than 0.001, respectively). No other statistically significant differences were found between the two groups for any of the remaining variables, including dietary estimates. Dietary analyses suggest that dietary intakes of SCA individuals exceeded the recommended daily allowances (RDA) of all macro- and micronutrients measured, and intakes of most nutrients exceeded those of black controls interviewed. These results suggest that in individuals with SCA, several micronutrients vital to maintaining reducing capacity are present in diminished quantities in plasma/serum. These anomalies exist in SCA patients even though their intake of these micronutrients are similar to those of healthy black men and women.

Adult↗
PubMed1989

Radiation therapy alone and in combination with bleomycin and 5-fluorouracil in advanced carcinoma esophagus.

This presentation is a randomized prospective study of 74 patients of squamous cell carcinoma of esophagus divided into two groups. First group was treated with radical radiation alone and the other with radical radiation and combination of bleomycin and 5-FU. Analysis at the end of two years showed that the patients treated with addition of chemotherapy had an overall survival of 23 percent as compared to nine percent in the radiation alone group (P less than 0.05).

Adult↗
PubMed1989

Electron beam irradiation in treatment of skin carcinoma.

Thirty seven cases of carcinoma of skin treated with electron-beam irradiation over a period of three years have been analysed retrospectively. Majority of lesions were in head and neck and basal-cell carcinoma was the commonest histological type. Of twenty-one patients followed, seventeen (81%) achieved complete remission and remained disease free for a period of one to three years. Cosmetic results were excellent. Role of electron-beam in the management of these superficial cancers and its advantage over the conventional radiation therapy methods have been highlighted. Radiation therapy utilising electron-beams form a very useful modality in the management of skin cancers, especially those arising in head and neck.

Adult↗
PubMed1987

Identification of a human liver cytochrome P-450 exhibiting catalytic and immunochemical similarities to cytochrome P-450 3a of rabbit liver.

Immunoblot analysis of liver microsomes from nine patients demonstrated that each contained a cytochrome P-450 that reacted with an antibody directed against the ethanol-inducible rabbit liver cytochrome, P-450 3a. Two of the liver specimens exhibited high concentrations of the immunoreactive protein, high rates of aniline hydroxylation and N-nitrosodimethylamine demethylation, and extensive inhibition of activity in the presence of antibody to P-450 3a. One other liver specimen exhibited a very low rate of aniline hydroxylation with significantly less antibody inhibition. The variability witnessed was independent of the alcohol history of the individual patients, suggesting that the human cytochrome may be under some other environmental, dietary or genetic regulation. Its inducibility by ethanol was not directly studied in this investigation. However, we conclude that there is a cytochrome P-450 present in human liver which is immunochemically and catalytically similar to the ethanol-inducible P-450 of rabbit liver.

Aniline Hydroxylase↗
PubMed1984

Quantitative analysis of pore patterns on rat prostate nuclei using spatial statistics methods.

Spatial statistics methods have been used to analyse the nuclear pore pattern in rat ventral prostate nuclei isolated from adult animals. The observed results show that: (1) pores on prostate nuclear membranes are not randomly distributed; (2) the data sets obtained from different micrographs are consistent with the same statistical model thus suggesting the existence of a typical pore distribution.

Animals↗
PubMed1983

[The place of surgery in the treatment of neuroblastoma].

From 1957 to 1980, 170 neuroblastoma were surgically approached: 3 cervical, 11 thoracic, 147 abdominal, 5 pelvic. The surgical data gathered from this large series leads us to assess that there are great differences between lateral and median neuroblastoma. Lateral ones can be surgically removed without major risk. Median ones arising from sympathetic nerves which depend on the aorta or on the visceral arteries (coeliac or mesenteric) cannot be removed totally without life-threatening risk. These data do not agree with Evans and d'Angio staging. Indeed, stage I and II are only observed in neuroblastomas developed on the lateral nerves of the sympathetic chain and can be removed. Stage III tumors can also be removed surgically when arising from a lateral site, even if they cross the median line. On the contrary all median perivascular neuroblastomas are to be staged III: total removal is not possible and the surgical risk is too high when compared with efficiency of chemotherapy. A special type, the distal perivascular neuroblastoma, is pointed out (5 cases). It is very important to precise exactly the initial localization of neuroblastoma, whatever be their metastatic extension. The new technics of investigation (C.T., ultrasonography, but also plain film and front and lateral views of intravenous pyelogram) allow to define precisely the median or lateral site of the tumor and also to choose between a non-surgical (median) or a surgical (lateral) treatment. This distinction seems in correlation with the two different ways of pathway of the embryonic neuroblast cells.

Abdominal Neoplasms↗
PubMed1982

A new formulation of Tc-99m minimicroaggregated albumin for marrow imaging: comparison with other colloids, In-111 and Fe-59.

The biodistributions of five Tc-99m colloids were compared with the 24-hr distributions of Fe-59 and In-111 in dogs by direct radioassay 1 hr after intravenous injection. One formulation of Tc-99m minmicroaggregated albumin (particle size 30-100 mn), produced the highest marrow concentration, approximately six times that of Tc-99m sulfur colloid, with similar blood, and liver concentrations and a lower splenic uptake. Nevertheless, the best colloid marrow uptake was lower than the 24-hr value for In-11 and much lower than that for Fe-59. The marrow concentration of minimicroaggregated albumin was also higher than that of sulfur colloid in rats at 30 min after injection. The principal disadvantage of Tc-99m antimony sulfide colloid was its slow blood clearance. Clinical evaluation of Tc-99m minimicroaggregated albumin for marrow imaging appears warranted, although its hepatic activity will obscure overlying and immediately adjacent marrow.

Animals↗
PubMed1981

Detection of experimentally produced acute pulmonary arterial occlusion by methyl iodide-131 inhalation imaging.

Methyl iodide-131 (CH3I-131) is described as an agent for detection of acute experimentally produced pulmonary arterial occlusion in dogs. When gaseous CH3I-131 is inhaled, radioactivity passes instantaneously from the alveoli to the lung capillary bed. Where pulmonary blood flow exists, activity is washed out into the systemic circulation, but in areas of blood stasis, a transient pulmonary "hot spot" remains. CH3I-131 is easily produced and inexpensive, but administration is awkward and strict radiation safety precautions are mandatory.

Animals↗
PubMed1980

Distribution of leukocytes labeled with In-111 oxine in dogs with acute inflammatory lesions.

The biodistributions of In-111 oxine (with and without leukocyte labeling) of Ga-67 citrate and of In-111 chloride were compared in 30 dogs with chemical and bacterial abscesses and acute joint inflammation. Serial blood samples were taken and tissues radioassayed at 24 hr. The concentration of In-111-oxine leukocytes in all three types of inflammatory lesion was invariably much higher than that of Ga-67 injected simultaneously. For bacterial abscesses, the mean abscess-to-muscle concentration ratio was 3,000 for labeled leukocytes and 72 for Ga-67. Aqueous buffered In-111 oxine sulfate solution appeared better for labeling leukocytes than In-111 oxine in ethanol. When In-111 oxine was not incubated with leukocytes before injection, or if the cells were poorly labeled or damaged, the abscess localization was often inferior to that of gallium. Localization of In-111 chloride also appeared inferior to that of gallium. No significant difference in distribution in the major organs or inflammatory lesions was demonstrable between labeled suspensions of "pure"neutrophils harvested by elutriation and "mixed"cell suspensions of leukocytes after erythrocyte sedimentation with hydroxyethyl starch. For both types of leukocyte suspension labeled with In-111 oxine, the average recovery of cell-bound activity in the circulating blood at 4 hr was 32% of the administered activity, inferior to that of DFP-32. It is concluded, therefore, that In-111 oxine is a more effective agent than Ga-67 for the detection of acute focal inflammatory lesions if leukocytes are properly labeled, but current techniques are unsatisfactory for the study of neutrophil kinetics.

Abscess↗
PubMed1980

Peripheral resistances in acute myocardial infarction: the use of prazosine versus isosorbide dinitrate.

Prazosine and isosorbide dinitrate have been studied in 15 patients with acute myocardial infarction complicated by heart failure. Prazosine at the first hour had a reduction of 39% of pulmonary capillary wedge pressure (PCWP), of 23% of systemic vascular resistences index (SVRI), of 20% of mean arterial pressure (AP). Isosorbide dinitrate at the first hour in a group of 7 patients had a decrease of SVRI by 19%, the cardiac index (CI) augmented by 23%, the PCWP fell by 15%, while in a group of 5 patients the drug had an increase of SVRI by 15%, a fall of 40% of PCWP and a slight decrease of CI.

Cardiac Output↗
PubMedDate not supplied

A multiphasic hollow fiber reactor for the whole-cell bioconversion of 2-methyl-1,3-propanediol to (r)-beta-hydroxyisobutyric acid.

This paper describes the bioconversion of 2-methyl-1,3-propanediol to (R)-beta-hydoxyisobutyric acid (HIBA) by Acetobacter ALEI in a hollow fiber membrane bioreaction system arrangement that allows the integration of three liquid phases: the aqueous bioconversion phase, the organic phase consisting of a solution of trioctyl phosphine oxide (TOPO) in isooctane, and the third phase consisting of a basic stripping solution that allows reextraction of HIBA from the organic phase. A comparison of HIBA mass transfer experiments was carried out in the membrane reactor with two and three phases for different pH and TOPO concentrations. The use of the three-phase arrangement allows the extraction of high quantities of HIBA from the aqueous medium (higher than 85%) independently of the pH, whereas in the two-phase system the percentage of HIBA extracted from the aqueous medium was lower, 42% in the best case, and strongly influenced by the pH. The percentage of the extractive agent TOPO in the organic phase influenced on the mass transfer rate in both bi- and triphasic arrangements. By simply integrating the re-extraction phase in the system it was possible to increase the extraction yield by 2-fold, reduce the amount of TOPO by 4-fold, and operate at the more favorable pH 4. A bioconversion experiment was done in these conditions (pH = 4, TOPO = 5%) to confirm the advantages of including the third stripping solution. Fed-batch operation of the triphasic membrane reactor was maintained for more than 20 h, reaching an HIBA concentration in the stripping solution of 29 g L(-)(1).

Acetobacter↗