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Biomedical subjects

F Augusto

Publications and source records attributed to F Augusto.

8 recordsLinked to original sources
PubMed2004

Acute necrotizing esophagitis: a large retrospective case series.

BACKGROUND AND STUDY AIMS: Acute necrotizing esophagitis is a rarely described entity. Its incidence has not yet been established, and its multifactorial etiology remains unknown. The aim of the present study was to establish the incidence, clinical presentation, endoscopic course, accompanying factors, and pathogenesis of the condition. PATIENTS AND METHODS: A retrospective analysis of clinical, laboratory, endoscopic and histological data and the clinical course in 29 patients with acute necrotizing esophagitis was carried out over a 5-year period. RESULTS: Acute necrotizing esophagitis was observed in 29 of 10 295 upper gastrointestinal endoscopies (0.28 %) carried out during the 5-year period. The average age of the patients was 75.24 years (range 40 - 91), and they were predominantly male. Eighty-three percent of the patients had comorbid conditions. In all cases, acute necrotizing esophagitis became evident with upper gastrointestinal bleeding, without hemodynamic stabilization in the majority of cases (75.9 %). The lesions predominantly affected the lower two-thirds of the esophagus (59 %), and there were coexisting abnormal endoscopic findings in 83 % of cases. Empirical supportive therapy, including oral nutritional rest, omeprazole, sucralfate (15 cases) and broad-spectrum antibiotics (7 cases) was provided. The condition resolved in all patients. Ten patients in the group died of other causes (coexisting illnesses). CONCLUSIONS: Acute necrotizing esophagitis was more commonly recognized than has previously been reported. It is a serious clinical entity that should be considered in the differential diagnosis of upper gastrointestinal bleeding, particularly in elderly patients. The prognosis depends more on the patient's advanced age and on comorbid illnesses than on the course of the esophageal lesions, which resolved in all patients in this series.

Acute Disease↗
PubMed2001

Monitoring biogenic volatile compounds emitted by Eucalyptus citriodora using SPME.

A procedure to monitor BVOC emitted by living plants using SPME technique is presented. For this purpose, a glass sampling chamber was designed. This device was employed for the characterization of biogenic volatile compounds emitted by leaves of Eucalyptus citriodora. After extraction with SPME fibers coated with PDMS/ DVB, it was possible to identify or detect 33 compounds emitted by this plant. A semiquantitative approach was applied to monitor the behavior of the emitted BVOC during 9 days. Circadian profiles of the variation in the concentration of isoprene were plotted. Using diffusion-based SPME quantitation, a recently introduced analytical approach, with extraction times as short as 15 s, it was possible to quantify subparts-per-billion amounts of isoprene emitted by this plant.

Butadienes↗
PubMed2001

Design and validation of portable SPME devices for rapid field air sampling and diffusion-based calibration.

The use of SPME fibers coated with porous polymer solid phases for quantitative purposes is limited due to effects such as interanalyte displacement and competitive adsorption. For air analysis, these problems can be averted by employing short exposure times to air samples flowing around the fiber. In these conditions, a simple mathematical model allows quantification without the need of calibration curves. This work describes two portable dynamic air sampling (PDAS) devices designed for application of this approach to nonequilibrium SPME sampling and determination of airborne volatile organic compounds (VOCs). The use of a PDAS device resulted in greater adsorbed VOC mass compared to the conventional SPME extraction in static air for qualitative screening of live plant aromas and contaminants in indoor air. For all studied air samples, an increase in the number of detected compounds and sensitivity was also observed. Quantification of aromatic VOCs in indoor air was also carried out using this approach and the PDAS/SPME device. Measured VOC concentrations were in low parts-per-billion by volume range using only 30-s SPME fiber exposure and were comparable to those obtained with a standard NIOSH method 1501. The use of PDAS/SPME devices reduced the total air sampling and analysis time by several orders of magnitude compared to the NIOSH 1501 method.

Journal Article↗
PubMed2001

Diffusion-based calibration for SPME analysis of aqueous samples.

When an SPME fiber is exposed for a short period of time to a flowing fluid sample, the amount of extracted analyte depends on its diffusion coefficient in the matrix medium, and it can be correlated to its concentration using a simple mathematical model. This work discusses the extension of this approach, already validated for gaseous samples and SPME fibers coated with strong adsorbent coatings, to the diffusion-based quantification of analytes present in aqueous samples. Dilute aqueous solutions of aromatic hydrocarbons were used as model samples and vials were modified to use conventional magnetic agitation with controlled tangential flow of the test solution around the fiber. It was demonstrated that, with proper selection of the stirring speed and sampling time, the same diffusion-based quantitative model used for gas samples could be employed. Under optimal conditions, the concentrations of the evaluated aromatic hydrocarbons were estimated with relative standard deviations between 0.8 and 3.6% and without deviation from the expected values within this precision range. Considering the extraction times involved, between 30 and 60 s, the approach here presented is the fastest possible technique for direct extraction of analytes from liquid samples.

Journal Article↗
PubMed2000

Screening of Brazilian fruit aromas using solid-phase microextraction-gas chromatography-mass spectrometry.

Manual headspace solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) was used for the qualitative analysis of the aromas of four native Brazilian fruits: cupuassu (Theobroma grandiflorum, Spreng.), cajá (Spondias lutea. L.), siriguela (Spondias purpurea, L.) and graviola (Anona reticulata, L). Industrialized pulps of these fruits were used as samples, and extractions with SPME fibers coated with polydimethylsiloxane, polyacrylate, Carbowax and Carboxen were carried out. The analytes identified included several alcohols, esters, carbonyl compounds and terpernoids. The highest amounts extracted, evaluated from the sum of peak areas, were achieved using the Carboxen fiber.

Fruit↗
PubMed1993

[Somatostatin and SMS 201-995 (octreotide): clinical and therapeutic aspects].

Nowadays, the digestive system, must be considered as an actual endocrinous gland. The authors, after pointing out the pharmacological and immunomodulating actions of endogenous somatostatine, briefly describe a new synthetic octapeptid, somatostatine-analogue, with similar pharmacological effects (octreotide). Finally they stress the therapeutic trials in which the adverse effects, dosage and administration have been studied.

Humans↗
PubMed1989

Assessing psychodynamic conflicts: I. Reliability of the idiographic conflict formulation method.

Recent years have seen increasing interest in devising methods of studying psychodynamic phenomena. These efforts have had confront difficulties, first, in specifying the data, the observation language, and rules of inference for psychodynamic propositions, and second, in determining the reliability and validity of the measures used. Given how "fuzzy" traditional psychodynamic concepts are, it is no wonder that psychodynamic clinicians from Freud onward have achieved more success in generating new hypotheses than in testing their validity. As Reichenbach (1938) has observed, science requires that discovery be followed by systematic validation of all new propositions, regardless of their degree of popular acceptance. At the core of efforts to study psychodynamics have been methods to study ego functioning (Bellak and Goldsmith 1984), defense mechanisms (Perry and Copper 1988), and psychodynamic conflicts. This paper reports on the reliability of the Idiographic Conflict Formulation (ICF), a guided method for formulating an individual's psychodynamic conflicts.

Antisocial Personality Disorder↗