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Biomedical subjects

A A Pereira

Publications and source records attributed to A A Pereira.

At least 19 recordsLinked to original sources
PubMed2005

European recommendations for the management of healthcare workers occupationally exposed to hepatitis B virus and hepatitis C virus.

Exposure prevention is the primary strategy to reduce the risk of occupational bloodborne pathogen infections in healthcare workers (HCW). HCWs should be made aware of the medicolegal and clinical relevance of reporting an exposure, and have ready access to expert consultants to receive appropriate counselling, treatment and follow-up. Vaccination against hepatitis B virus (HBV), and demonstration of immunisation before employment are strongly recommended. HCWs with postvaccinal anti-HBs levels, 1-2 months after vaccine completion, >or=10 mIU/mL are considered as responders. Responders are protected against HBV infection: booster doses of vaccine or periodic antibody concentration testing are not recommended. Alternative strategies to overcome non-response should be adopted. Isolated anti-HBc positive HCWs should be tested for anti-HBc IgM and HBV-DNA: if negative, anti-HBs response to vaccination can distinguish between infection (anti-HBs >or=50 mUI/ml 30 days after 1st vaccination: anamnestic response) and false positive results(anti-HBs >or=10 mUI/ml 30 days after 3rd vaccination: primary response); true positive subjects have resistance to re-infection. and do not need vaccination The management of an occupational exposure to HBV differs according to the susceptibility of the exposed HCW and the serostatus of the source. When indicated, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible (within 1-7 days). In the absence of prophylaxis against hepatitis C virus (HCV) infection, follow-up management of HCV exposures depends on whether antiviral treatment during the acute phase is chosen. Test the HCW for HCV-Ab at baseline and after 6 months; up to 12 for HIV-HCV co-infected sources. If treatment is recommended, perform ALT (amino alanine transferase) activity at baseline and monthly for 4 months after exposure, and qualitative HCV-RNA when an increase is detected.

Antiviral Agents↗
PubMed2001

Transfer of clarithromycin to gastric juice is enhanced by omeprazole in Helicobacter pylori-infected individuals.

BACKGROUND: The effects of proton-pump inhibitors and Helicobacter pylori infection on the distribution of drugs employed for the eradication of H. pylori are poorly understood. The aim of this study was to investigate the effects of a 7-day oral administration of 20 mg omeprazole on the distribution of clarithromycin in the gastric juice of individuals with H. pylori infection. METHODS: Eighteen H. pylori-infected dyspeptic male volunteers without endoscopic lesions were enrolled in a study with an open, randomized, two-period crossover design and a 21-day washout period between phases. Plasma and gastric juice concentrations of clarithromycin in subjects with and without omeprazole pretreatment were measured by means of liquid chromatography coupled to tandem mass spectrometry. RESULTS: The maximum concentration of clarithromycin (Cmax) and the area under the time-concentration curve from 0 to 2 h (AUC0-2h) were significantly higher in gastric juice than in plasma. Omeprazole treatment further augmented clarithromycin Cmax and AUC0-2h in gastric juice approximately 2-fold (P < 0.05). CONCLUSIONS: Short-term treatment with omeprazole in H. pylori-positive volunteers increases the amount of clarithromycin transferred to the gastric juice, confirming a synergism between these drugs. Our results suggest the presence of an active transport mechanism for clarithromycin from plasma to the gastric lumen, which is influenced by omeprazole.

Adult↗
PubMed2001

Susceptibility of S. pneumoniae to various antibiotics aong strains isolated from patients and healthy carriers in different regions of Brazil(1999-2000).

Resistance of microbes to commonly used antibiotics became a major concern at the end of the last century. Because Streptococcus pneumoniae is the most common pathogen in respiratory infections, we conducted microbiological assessment of drug susceptibility patterns among strains collected from two different population groups: 1) adult and pediatric patients (375 isolates) with different infections, and 2) healthy children in day care centers (<5 years old; 350 isolates). High level resistance to penicillin was not identified in either group. Intermediate resistance levels were similar in both groups (adults: 9.9%; children: 9.2%). The Central West region of Brazil tended to have lower susceptibility of S. Pneumoniae from infected adults and children to penicillin (81% vs. 93% in the South and 90% in the Southeast), tetracycline (64% vs. 80% and 76%), and trimethoprim/sulfamethoxazole (14% vs. 34%). Susceptibility was similar among strains from nasal cultures of healthy children tested in each of 4 regions of Brazil. All isolates were susceptible to cefaclor, cefotaxime and amoxacillin/clavulanate. This study, in two distinct populations, allowed characterization of local microbiological resistance patterns. This data is expected to be of use in guiding empiric therapy in the different regions of Brazil.

Adult↗
PubMed2000

Effect of spores of saprophytic fungi on phytoalexin accumulation in seeds of frog-eye leaf spot and stem canker-resistant and -susceptible soybean (Glycine max L.) cultivars.

Two saprophytic fungi (Mucor ramosissimus and Rhizopus sp.) were tested for their ability to induce phytoalexin production by seeds of frog-eye leaf spot and stem canker-resistant and -susceptible soybean (Glycine max L.) cultivars. Only M. ramosissimus was shown to elicit a response and qualitative differences in phytoalexin accumulation were found between the susceptible and resistant cultivars. Glyceollins I, II, and III and glycinol were isolated from the susceptible cultivar, whereas Glyceollins I, II, and III, glycinol, glyceocarpin, genistein, isoformononetin, and N-acetyltyramine accumulated in the resistant cultivar in response to the same fungal elicitor. Genistein was found to be an inducibly formed isoflavonoid instead of a constitutive metabolite in the resistant cultivar, whereas N-acetyltyramine is described for the first time as a soybean phytoalexin. All the compounds, except genistein, showed fungitoxic activity against Cladosporium sphaerospermum. Spectral data of the pterocarpan phytoalexins, genistein, and N-acetyltyramine are also given in this work.

Mucor↗
PubMed2000

Transfer of metronidazole to gastric juice: impact of Helicobacter pylori infection and omeprazole.

BACKGROUND: The effects of Helicobacter pylori infection associated with inhibition of gastric acid secretion on the distribution of medications used for H. pylori eradication are poorly understood. The aim of this study was to investigate the effects of a 7-day administration of 20 mg omeprazole on the transfer of metronidazole from plasma to the gastric juice of individuals with and without H. pylori infection. METHODS: Fourteen H. pylori-positive and 14 H. pylori-negative male volunteers were enrolled in a study with an open, randomized, two-period crossover design with a 21-day washout period between phases. Plasma, salivary, and gastric juice concentrations of metronidazole in subjects with and without omeprazole treatment were measured with reversed-phase high-performance liquid chromatography/liquid chromatography. RESULTS: Metronidazole peak concentration (Cmax) was similar in plasma and saliva and was approximately threefold higher in gastric juice in all groups. Omeprazole treatment increased gastric pH and did not affect metronidazole Cmax or the time required for this to be reached (tmax) in plasma, saliva, or gastric juice. However, omeprazole significantly reduced metronidazole transfer from plasma to gastric juice in H. pylori-positive but not H. pylori-negative subjects, as shown by statistical analysis of AUC(0-2 h). CONCLUSION: Short-term treatment with omeprazole in H. pylori- positive volunteers reduces the amount of metronidazole transferred from plasma to gastric juice. This seems to occur in a pH-independent form.

Adult↗
PubMed1999

[Activities at an Infectious Disease Intensive Care Unit (1988-1997)].

The practice of an Infectious Diseases Intensive Care Unit for a period of ten years (1988-1997) is reviewed. In this time 1,191 patients were treated--822 had more than 15 years of age and 369 were younger. The occupation rate ranged between 74.4% and 90.8%, and the mean patient stay in the UCI ranged between 6.7 and 12.5 days. Nine hundred and forty-four patients were discharged cured or improved during the stay and 247 (20.7%) died. The most frequent pathologies were: meningitis--371 patients (33.6%); encephalitis--103 (8.6%); and tetanus 143 (12.0%) patients. The morbidity and mortality of different pathologies admitted to the Intensive Care Unit are presented. The mortality rate of the two most common diseases (meningitis and tetanus) is discussed. The need for Intensive Care in the field of Infectious Diseases is stressed.

Adolescent↗
PubMed1991

Computed tomography and ultrasonography of the adrenal glands in paracoccidioidomycosis. Comparison with cortisol and aldosterone responses to ACTH stimulation.

Fifteen patients with proven disseminated paracoccidioidomycosis (PCM) had computed tomography (CT) and ultrasonography (US) performed to evaluate the form, shape, density and size of their adrenal glands. Plasma and urinary cortisol were determined and adrenal reserve assessed by measuring the cortisol and aldosterone responses to synthetic ACTH. The adrenal CT showed unilateral lesions in two cases and bilateral in another four. The US study showed more frequent alterations, unilateral in seven and bilateral in three subjects. Combining both methods increased the sensitivity to 85% of the cases. All patients had normal plasma cortisol concentrations and normal or increased urinary cortisol excretion. Plasma aldosterone concentration was also normal except in one patient with hypokalemia. Seven patients showed diminished cortisol responses, five had subnormal aldosterone responses and in five plasma aldosterone concentration increased more than normally after stimulation by ACTH. There was an incidence of limited adrenal reserve in 53% of the patients on ACTH stimulation. No correlation was evident between the disorders in adrenal steroid responses to ACTH and changes in morphology revealed by CT and/or US.

Adrenal Glands↗
PubMed1976

Comparative kinetics of arginine and lysine transport by epimastigotes and trypomastigotes from two strains of Trypanosoma cruzi.

Three-day-old cultures of Y and MR strains of Trypanosoma cruzi ahd a higher rate of lysine and arginine uptake than 10-day cultures. Amino acid uptake by cells of the MR strain was consistently higher than that of the Y strain. Flagellates separated on DEAE-cellulose columns have normal structure, motility, and infectivity; they have the higher rates of lysine and arginine uptake than the original 3- and 10-day cultures. In addition passage through DEAE-cellulose columns modified the kinetic behavior of amino acid transport systems in the flagellate membranes.

Animals↗