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Biomedical subjects

P Andrade

Publications and source records attributed to P Andrade.

At least 19 recordsLinked to original sources
PubMed2006

Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings.

A dynamic headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to ion trap mass spectrometry (GC-(IT)MS) method was developed and applied for the qualitative determination of the volatile compounds present in commercial whisky samples which alcoholic content was previously adjusted to 13% (v/v). Headspace SPME experimental conditions, such as fibre coating, extraction temperature and extraction time, were optimized in order to improve the extraction process. Five different SPME fibres were used in this study, namely, poly(dimethylsiloxane) (PDMS), poly(acrylate) (PA), Carboxen-poly(dimethylsiloxane) (CAR/PDMS), Carbowax-divinylbenzene (CW/DVB) and Carboxen-poly(dimethylsiloxane)-divinylbenzene (CAR/PDMS/DVB). The best results were obtained using a 75 microm CAR/PDMS fibre during headspace extraction at 40 degrees C with stirring at 750 rpm for 60 min, after saturating the samples with salt. The optimised methodology was then applied to investigate the volatile composition profile of three Scotch whisky samples--Black Label, Ballantines and Highland Clan. Approximately seventy volatile compounds were identified in the these samples, pertaining at several chemical groups, mainly fatty acids ethyl esters, higher alcohols, fatty acids, carbonyl compounds, monoterpenols, C13 norisoprenoids and some volatile phenols. The ethyl esters form an essential group of aroma components in whisky, to which they confer a pleasant aroma, with "fruity" odours. Qualitatively, the isoamyl acetate, with "banana" aroma, was the most interesting. Quantitatively, significant components are ethyl esters of caprilic, capric and lauric acids. The highest concentration of fatty acids, were observed for caprilic and capric acids. From the higher alcohols the fusel oils (3-methylbutan-1-ol and 2.phenyletanol) are the most important ones.

Alcoholic Beverages↗
PubMed1999

Endosonography in the diagnosis of "blue rubber bleb nevus syndrome": an uncommon cause of gastrointestinal tract bleeding.

Blue rubber bleb nevus syndrome is a rare condition characterized by the presence of multiple angiomatic lesions of the skin. These are associated with similar lesions in other organs, namely in the gastrointestinal tract, causing anemia through chronic bleeding. We describe the case of a 72-year-old woman with microcytic anemia. A barium study revealed irregular lacunae in the distal esophagus. A subsequent endoscopy showed blue nodular lesions similar to angiomas of the esophagus and stomach fundus. Endosonography confirmed its angiomatic nature. Exploration of other organs, using magnetic resonance and cranial computed tomography, did not reveal the presence of this type of lesion. In physical examination, two angiomatic lesions were observed on the face and lips, respectively. These were blue in color and compressible, leaving an empty wrinkled sac that rapidly refilled, typical of angiomas.

Aged↗
PubMed1996

Mesenteric arteriovenous fistula causing portal hypertension and bleeding duodenal varices.

We report a case of portal hypertension associated with a non-traumatic arteriovenous fistula, presenting with bleeding duodenal varices. The patient was admitted for melaena. Emergency endoscopy showed oesophageal varices with no signs of recent bleeding and with no blood in the upper gastrointestinal tract. Arteriography of the coeliac axis and superior mesenteric artery failed to detect any bleeding source. Endoscopy was repeated because of persistent bleeding and revealed active bleeding from varices in the distal duodenum. The patient underwent surgery and a large paraduodenal varicose vein associated with an arteriovenous fistula was found. Resection of the paramural varix and surgical occlusion of the arteriovenous fistula were effective in the control of bleeding. Liver biopsy revealed mild portal fibrosis without cirrhosis. Three years after surgery the patient still has oesophageal varices but has not had recurrent bleeding. There was regression of intraduodenal varices.

Aged↗
PubMed1995

Influence of non-steroidal anti-inflammatory drugs on renal function and 24h ambulatory blood pressure-reducing effects of enalapril and nifedipine gastrointestinal therapeutic system in hypertensive patients.

OBJECTIVE: To evaluate the influence of non-steroidal anti-inflammatory drugs (NSAIDs; aspirin and indomethacin) on the renal and antihypertensive effects of enalapril and nifedipine gastrointestinal therapeutic system (GITS) in patients with essential hypertension. DESIGN AND METHODS: In a crossover study, 18 patients on an unrestricted-salt diet were randomly assigned to receive either enalapril (20-40 mg/day) or nifedipine-GITS (30-60 mg/day) for 4-8 weeks, followed by aspirin (100 mg/day for 2 weeks) and then indomethacin (75 mg/day for 1 week). Blood pressure was measured by 24h ambulatory monitoring. RESULTS: Enalapril and nifedipine-GITS significantly reduced blood pressure compared with placebo. Aspirin did not alter the antihypertensive effect of either drug. Indomethacin attenuated (by 45%) the antihypertensive effect of enalapril throughout the 24h period of evaluation, but did not interfere with the effect of nifedipine. Furthermore, indomethacin significantly reduced the fractional excretion of sodium and plasma levels of prostaglandins in a similar way when added to either the enalapril or the nifedipine regimen. CONCLUSIONS: Vasodilatory prostaglandins are probably involved in the antihypertensive effects of enalapril but not of nifedipine, and this interaction seems to be independent of any indomethacin-induced decrease in renal sodium excretion. Nifedipine may be an appropriate drug to treat hypertensive patients requiring concomitant therapy with NSAID.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

[Gamma-glutamyltransferase and alcoholic hepatic disease].

Accepting the principle that Gama-gt values are elevated in alcoholic patients, the authors attempted to find out if that enzyme might be helpful in distinguishing alcoholics with or without hepatic morphologic lesion. 110 alcoholic patients with and 57 without histologically proved hepatic lesion were studied. The authors conclude that a single determination of Gama-gt lacks specificity to detect, among the alcoholic individuals, those who already carry a morphologic, nonreversible lesion.

Adult↗
PubMed1989

Nasal polyps: a manifestation of allergy?

The cause of nasal polyps is speculative. In the 1930s nasal polyps were considered to be a manifestation of allergy. This theory was challenged in the 1970s. Many patients with nasal polyps have no identifiable allergic disease. The purpose of this study is to better define the relationship between allergy and nasal polyps. Twelve patients with nasal polyps were evaluated by history, physical examination, skin testing, nasal smear for eosinophils, specific IgE determination from serum, nasal secretions, and nasal polyp fluid. Similar data were collected from three control groups: (1) 10 patients with allergic rhinitis, (2) 10 patients with nonallergic rhinitis, and (3) 10 patients with no known nasal disease. By comparing the incidence of markers for allergic disease in patients with nasal polyposis to each of the three control groups, the role of allergic disease in nasal polyposis was delineated.

Adult↗
PubMed1984

Self-care. Substitute, supplement, or stimulus for formal medical care services?

This article examines the relationship between selected self-care practices during an episode of illness and the use of formal medical care. Stimulated by conflicting evidence and assertions, the general question addressed is: "Is self-care a substitute, a supplement, or a stimulus for use of formal medical care services?" Multiple Classification Analysis was used in a secondary data analysis of a 1976 nationwide study on access to medical care. The results suggest that self-care users may visit the physician less often and stay fewer days in the hospital, and thus they are expected to have lower expenditures for hospital and physician services. Therefore, the self-care activities examined appear to be substitutes for, rather than supplements or stimuli to, health services utilization. The results must be viewed with some caution due to limitations in the data. However, the results also argue for a greater research emphasis on self-care.

Adolescent↗
PubMed1983

A new interpretation of the origin of extradural space negative pressure.

The negative pressure in the extradural space is the result of the interaction of hydrostatic forces created between the vertebral canal (a stiff-walled cylinder) and the dura mater, with its content of cerebro-spinal fluid (CSF), which behaves as a cylinder that can collapse according to the position of the subject. In order to corroborate this hypothesis, we have designed a model formed by a sealed, water-filled, glass cylinder ("vertebral canal"). In the interior there is a collapsible, non-distendible, water-filled cylinder ("dural sac"), in free communication with a reservoir which represents the CSF contained in the cranial cavity. Changes in the position of the model produce subatmospheric pressure in the space between both cylinders ("extradural space"), as happens in man.

Epidural Space↗
PubMed1980

Extraction efficiencies for pesticides in crops: 14C-benomyl extraction from mustard green and radishes.

14C-labeled benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate] suspended in a commercial benomyl formulation was sprayed on mustard greens and radishes. At 3 intervals after application, the crops were extracted with methanol, acetonitrile, or acetone. Crops were either blended and leached or repetitively blended followed by Soxhlet extraction. Essentially all of the extractable radioactivity was removed by blending. The 14C was more difficult to extract from radishes than from mustard greens as time increased. Respective percentages of 14C extracted at 1, 7, and 14 days were 99, 98, and 97 from mustard greens and 96, 88, and 79 from radishes. Methanol exhibited the highest extraction efficiency, and the blend-Soxhlet process was better than the blend-leach process. Thin layer chromatography of the organic-soluble extracts indicated that the majority of 14C was recovered as methyl 2-benzimidazole carbamate (MBC), a breakdown product of benomyl. Acid hydrolysis of the extracted tissues released 30--50% of the residual 14C.

Benomyl↗
PubMedDate not supplied

Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii.

Genetic differentiation among nine populations of the endemic lizard Lacerta dugesii Milne-Edwards 1829 (Lacertidae) from four groups of islands constituting the Archipelago of Madeira, was investigated by protein electrophoresis at 23 enzyme loci. Among twenty polymorphic loci, the total genetic diversity was due primarily to intra-population variation. The allele and genotypic frequencies among populations showed some heterogeneity, allowing the species to present a structuring pattern compatible with their geographical clustering. Some evidence suggests that selection acting on some loci in different ecological conditions may be responsible for the clustering of the populations studied. There was no apparent isolation effect expected under an "island" model of population divergence, and no correlation was found between genetic and geographic distances among populations. Morphological variation of the proposed three L. dugesii subspecies is not congruent with the allozyme analysis. This most probably suggests a rapid colonization of the islands followed by a strong effect of selection operating over the morphological characters used to define the subspecies.

Adaptation, Physiological↗