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Biomedical subjects

S Andrade

Publications and source records attributed to S Andrade.

At least 19 recordsLinked to original sources
PubMed2007

Gender differences of acute and chronic administration of dehydroepiandrosterone in rats submitted to the forced swimming test.

Previous pre-clinical and clinical studies investigating the antidepressant potential of DHEA revealed conflicting results. In this study, the effects of exogenous DHEA on performance in the forced swimming test (FST) were examined in male and female Wistar rats in different phases of the estrous cycle. Furthermore, the effects of treatment and of the FST, on corticosterone and DHEA serum levels were investigated. Acute administration of DHEA (2 mg/kg) significantly increased freezing only in proestrus female rats. Similarly, the chronic administration of DHEA (2 mg/kg) increased freezing duration and decreased climbing behavior but only in females in diestrus II compared to those given vehicle. These results demonstrate that chronically administered DHEA induces a depressant-like effect, and this effect is sex dependent. There was no direct correlation between corticosterone levels or the corticosterone/DHEA ratio and the behaviors studied. After the FST, serum DHEA and corticosterone levels were increased, with females showing higher DHEA levels than males. Nevertheless, corticosterone levels were unaltered with chronic procedure; an effect that was independent of sex and treatment. These findings are relevant for research examining alternative treatment for depression and may elucidate the gender differences involved in stress-related diseases.

Adjuvants, Immunologic↗
PubMed2005

Concurrent cisplatin/gemcitabine chemotherapy along with radiotherapy in locally advanced cervical carcinoma: a phase II trial.

OBJECTIVE: To evaluate the efficacy and safety of a concurrent regimen of gemcitabine/cisplatin and radiotherapy in women with locally advanced cervical carcinoma (LACC). METHODS: From April 2001 to June 2002, we enrolled women diagnosed with histologically proven LACC (FIGO stages IIA through IIIB), for treatment with concurrent regimen of chemo-radiotherapy. The treatment consisted of: cisplatin 40 mg/m(2), followed by gemcitabine 125 mg/m(2), once weekly, given about 1 to 2 h before radiotherapy. External beam radiation was delivered 5 days/week to entire pelvic radiation field for a total of 50 Gy in 25 fractions over 5 weeks. After completion of external radiation, patients received brachytherapy with cesium-137 via standard Fletcher-suit applicators delivering 30 Gy to point A. RESULTS: Of the 23 enrolled patients (mean age 47 years), 20 completed the treatment and were evaluable for response and safety. The complete response rate was 90% (18/20), and partial response rate was 10% (2 patients with persistent disease after therapy). Toxicity was moderate: 2 patients required blood transfusions; 5% patients had grade 2 leukopenia or thrombocytopenia; 40% had grade 1-2 nausea-vomiting, and 50% had grade 1 diarrhea. At a median follow-up of 12 months, all patients are alive, and 16/20 (80%) are disease-free. CONCLUSIONS: The gemcitabine/cisplatin combination administered concurrently with radiotherapy is highly active in locally advanced cervical carcinoma. The tolerable toxicity and synergistic activity of this concurrent chemoradiation regimen are consistent with prior reports. Definitive results are awaited from an on-going large, randomized trial comparing this regimen with standard treatment.

Adult↗
PubMed2005

Copper bioavailability in a coastal environment of Northern Chile: comparison of bioassay and analytical speciation approaches.

An integrated approach including chemical speciation analyses and microalgal bioassays was used to assess the impact of copper from copper mining on a coastal area in Northern Chile. Dissolved copper ranged from <1 microg l(-1) at reference sites to 48 microgl(-1) at sites close to the mine discharge. Dissolved copper at sites closest to the discharge always exceeded seawater complexing capacities determined by anodic stripping voltammetry (ASV), and consequently labile copper was always detected (1-37 microg l(-1)). Agreement between ASV-labile copper and copper retained by cation exchange (ALSA) columns was excellent. Measured labile copper also accurately predicted bioavailable copper determined by growth inhibition of Nitzschia closterium and enzyme inhibition in Dunaliella tertiolecta. Seawater from Caleta La Lancha had the highest dissolved and labile copper and was the most toxic to micro-algal growth and enzyme activity. Previous studies at this site confirmed it had the lowest level of biodiversity, suggesting that copper may have both direct and indirect effects on these communities.

Biological Assay↗
PubMed2005

Urban versus rural environment--any differences in aeroallergens sensitization in an allergic population of Cova da Beira, Portugal?

Cova da Beira is an interior central region of Portugal, with a population of 93000 inhabitants divided in urban and rural living areas. The aim of this study was to access the prevalence of aeroallergens sensitisation in an allergic population, according to the urban and the rural environmental exposure and according to age. 1096 patients observed for suspected allergic symptoms, for a five-year period (1995-2000) were submitted to skin prick tests and were included in this study. They were divided in two environmental exposure groups (A: urban; B: rural) and in to four age subgroups (subgroup I: < or = 10yr; subgroup II: 11-20yr; subgroup III: 21-40yr; subgroup IV: >40yr). The total population included 444 male (40.5%) and 652 female (59.4%) with an average age of 26.5 +/- 17.2 yr. 83% of the 1096 performed SPT were positive. The frequency of aeroallergens sensitisation, comparing the urban versus the rural environment, was respectively: D. pteronyssinus 32% and 34.7%, D. farinae 28.5% and 30.7%, moulds mixture 15.3% and 12%, cat dander 17.1% and 15.2%, dog dander 11% and 10%, grasses mixture 51.3% and 36.4%, Parietaria judaica 29.4% and 14%, Olea europea 30.2% and 23.3%. The sensitisation to indoor aeroallergens, was similar in all the age subgroups and it was lower than that to pollens. There were important differences concerning the pollen sensitisation, when comparing the urban and the rural environmental exposure. We admit that pollution could enhance the sensitisation to pollens in the urban environment.

Adolescent↗
PubMed2004

Biodiversity of rocky intertidal benthic communities associated with copper mine tailing discharges in northern Chile.

Copper mine tailings have been discharged around the city of Chanaral, in northern Chile, for more than 60 years. This report summarizes a 17-month long monitoring study of species richness and biodiversity at five intertidal sites around the point of the tailing discharge. Total dissolved copper in sites close to the point of discharge varied between 8.72 microg/l and 34.15 microg/l, showing that there has not been a significant reduction since 1994. However, species richness has increased, suggesting a possible recovery of the system. While diversity of sessile organisms correlates negatively with dissolved copper, diversity of mobile invertebrates did not correlate with the metal concentration. To explain the observed results we discuss the role of algal turf interference on the distribution of mobile invertebrates at reference sites, a top-down effect caused by the absence of carnivores at impacted sites, and an avoidance strategy by some species to reduce their contact with contaminated seawater.

Animals↗
PubMed2004

Antimicrobial susceptibility to levofloxacin and other antibacterial agents among common respiratory pathogens-a Brazilian perspective from the GLOBAL Surveillance Initiative 2001-2002.

The GLOBAL (Global Landscape On Bactericidal Activity of Levofloxacin) Surveillance programme monitored antimicrobial susceptibility patterns of the key respiratory tract pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis collected in Brazil during 1997-1998, 1999-2000 and 2001-2002. Penicillin and azithromycin resistance among S. pneumoniae strains increased from 1997-1998, reaching 7.9% and 9.5%, respectively, in 2001-2002. Although decreasing by 4.9% since the previous study, trimethoprim-sulphamethoxazole resistance remained high at 33.7%. Concurrent resistance to penicillin, azithromycin and trimethoprim-sulphamethoxazole was seen in 2.9% of the S. pneumoniae isolates collected. Levofloxacin remained extremely active against S. pneumoniae, with 0.3% resistance reported in 1997-1998 and 0% resistance in 1999-2000 and 2001-2002. beta-Lactamase production in H. influenzae was > 10% in all three studies, with correspondingly high rates of ampicillin resistance. Trimethoprim-sulphamethoxazole was the least active agent tested against H. influenzae, with resistance rates of > 40% recorded in all three studies. All H. influenzae isolates were susceptible to cefuroxime, ceftriaxone, azithromycin and levofloxacin. Of the M. catarrhalis isolates, 98.0% in 1997-1998, 98.0% in 1999-2000 and 81.8% in 2001-2002 were beta-lactamase-positive. The continued high prevalence of antimicrobial resistance in Brazil underscores the importance of current surveillance initiatives. Levofloxacin, a fluoroquinolone prescribed widely for respiratory tract infections, continued to show potent activity against key respiratory pathogens.

Anti-Bacterial Agents↗
PubMed2001

Distribution of heavy metals in surface sediments from an Antarctic marine ecosystem.

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Antarctic Regions↗
PubMed2001

Patient education provided to asthmatic children: a historical cohort study of the implementation of NIH recommendations.

NIH guidelines for treatment of childhood asthma emphasize educating both patients and family about avoiding triggers and providing information to support self-management of asthma. To determine the extent to which primary care providers had implemented these recommendations, we examined the patient education provided to a cohort of asthmatic children (n = 331) between January and December 1994. During 1994 education of any type was documented for less than half the children. Provision of education was associated with asthma severity: An action plan for exacerbations was discussed with the majority with moderate or severe asthma (61%). Avoiding triggers (aOR: 2.38, 95% CI: 1.37-4.12) and treatment goals (aOR: 3.14, 95% CI: 1.46-6.75), were more likely to be discussed with children who were prescribed inhaled anti-inflammatory medication, after adjustment for asthma severity and age. Limited implementation of the NIH recommendations by primary care providers in our study may have reduced their impact on the management of childhood asthma.

Administration, Inhalation↗
PubMed1998

Compliance in the real world.

Until 1994, rates of noncompliance for lipid-lowering therapies were largely drawn from clinical trials and showed favorable risks for drug discontinuation, ranging from 4-15% for 1-year risk to 11-30% for 5-year risk. Although cross-study comparisons are difficult to make because of variations in study design and measures collected, when evaluating compliance to antihyperlipidemic drugs in primary care settings, results in general show substantially higher rates of discontinuation than those reported from randomized clinical trials. Recent studies from the United States, Australia, and Canada support the conclusion that adherence to lipid-lowering drugs is very poor in primary care settings.

Journal Article↗
PubMed1998

Iron supplementation in haemodialysis--practical clinical guidelines.

BACKGROUND: The aim of this prospective study was to test a new protocol for iron supplementation in haemodialysis patients, as well as to assess the utility of different iron metabolism markers in common use and their 'target' values for the correction of iron deficiency. METHODS: Thirty-three of 56 chronic haemodialysis patients were selected for long-term (6 months) i.v. iron therapy at 20 mg three times per week post-dialysis based on the presence of at least one of the following iron metabolism markers: percentage of transferrin saturation (%TSAT) <20%; percentage of hypochromic erythrocytes (%HypoE) > 10% and serum ferritin (SF) <400 microg/l. Reasons for patient exclusion were active inflammatory or infectious diseases, haematological diseases, psychosis, probable iron overload (SF > or =400 microg/l) and/or acute need of blood transfusion mostly due to haemorrhage and change in renal replacement treatment. RESULTS: More than half (51.8%) of the patients of our dialysis centre proved to have some degree of iron deficiency in spite of their regular oral iron supplementation. At the start of the study the mean haemoglobin was 10.8 g/dl and increased after the 6 months of iron treatment to 12.8 g/dl (P<0.0001). The use of erythropoietin decreased from 118 units/kg/week to 84 units/kg/week. The criterion for iron supplementation with the best sensitivity/specificity relationship (100/87.9%) was ferritin <400 microg/l. Patients with ferritin < 100 [microg/l and those with ferritin between 100 microg/l and 400 microg/l had the same increase in haemoglobin but other parameters of iron metabolism were different between the two groups. CONCLUSIONS: Routine supplementation of iron in haemodialysis patients should be performed intravenously. Target ferritin values should be considered individually and the best mean haemoglobin values were achieved at 6 months with a mean ferritin of 456 microg/l (variation from to 919 microg/l). The percentage of transferrin saturation, percentage of hypochromic erythrocytes and ferritin <100 microg/l, were not considered useful parameters to monitor routine iron supplementation in haemodialysis patients. No significant adverse reactions to iron therapy were observed.

Anemia, Iron-Deficiency↗
PubMed1997

The use of epilithic Antarctic lichens (Usnea aurantiacoatra and U. antartica) to determine deposition patterns of heavy metals in the Shetland Islands, Antarctica.

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized.

Air Pollutants↗
PubMed1997

Encapsulation of flavodoxin in reverse micelles.

The regulation of the properties of Desulfovibrio gigas flavodoxin in AOT/water/iso-octane micellar system was studied. UV-visible spectroscopic studies have shown that photoreduction of flavodoxin in the presence of EDTA leads to hydroquinone formation through the intermediate semiquinone. The [free FMN] - [bound to flavodoxin FMN] equilibrium (and hence, the amount of apoprotein) depends on redox state of FMN and on hydration degree which controls the micellar size. Thus, a new method of reversible cofactor removing under mild conditions (at low hydration degree of micelles) is suggested, accompained by isolation of apo-form of the protein.

Desulfovibrio↗
PubMed1994

Continuous administration of anti-interleukin 10 antibodies delays onset of autoimmunity in NZB/W F1 mice.

We have previously shown that continuous administration of anti-interleukin 10 (anti-IL-10) antibodies (Abs) to BALB/c mice modifies endogenous levels of autoantibodies, tumor necrosis factor alpha (TNF-alpha), and interferon gamma, three immune mediators known to affect the development of autoimmunity in "lupus-prone" New Zealand black/white (NZB/W)F1 mice. To explore the consequences of IL-10 neutralization in NZB/W F1 mice, animals were injected two to three times per week from birth until 8-10 mo of age with anti-IL-10 Abs or with isotype control Abs. Anti-IL-10 treatment substantially delayed onset of autoimmunity in NZB/W F1 mice as monitored either by overall survival, or by development of proteinuria, glomerulonephritis, or autoantibodies. Survival at 9 mo was increased from 10 to 80% in anti-IL-10-treated mice relative to Ig isotype-treated controls. This protection against autoimmunity appeared to be due to an anti-IL-10-induced upregulation of endogenous TNF-alpha, since anti-IL-10-protected NZB/W F1 mice rapidly developed autoimmunity when neutralizing anti-TNF-alpha Abs were introduced at 30 wk along with the anti-IL-10 treatment. Consistent with the protective role of anti-IL-10 treatment in these experiments, continuous administration of IL-10 from 4 until 38 wk of age accelerated the onset of autoimmunity in NZB/W F1 mice. The same period of continuous IL-10 administration did not appear to be toxic to, or cause development of lupus-like autoimmunity in normal BALB/c mice. These data suggest that IL-10 antagonists may be beneficial in the treatment of human systemic lupus erythematosus.

Animals↗
PubMed1994

In vivo effects of interleukin-10 on contact hypersensitivity and delayed-type hypersensitivity reactions.

Interleukin (IL) 10 is a recently discovered cytokine, originally isolated from T-helper 2 (Th2) cells, which inhibits cytokine production of T-helper 1 (Th1) cells. Because Th1 cells appear to be of importance during the contact hypersensitivity reaction (CHS) we hypothesized that IL-10 might modulate the outcome of CHS in vivo. Intraperitoneal injection of murine recombinant IL-10 (1000 ng) into naive mice 24, 72, or 120 h before sensitization by epicutaneous application of 2,4-dinitrofluorobenzene (DNFB) did not affect ear swelling when ears were challenged 5 d later. However, intraperitoneal injection of IL-10 into already sensitized mice 24 h before challenge resulted in a significant suppression of the ear swelling response, suggesting that under the conditions employed IL-10 is able to block the effector phase, but not the induction phase of CHS in vivo. The suppression could be reversed by the concurrent injection of an IL-10 antibody. Moreover, heat inactivation of native IL-10 resulted in loss of the inhibitory capacity. When mice were sensitized by subcutaneous injection of trinitrophenyl-coupled spleen cells (DTH) instead of epicutaneous application of the hapten (CHS), intraperitoneally-injected IL-10 suppressed the effector phase, but also the induction phase of DTH. IL-10 did not inhibit the toxic ear-swelling response induced by topical application of two irritants tested (croton oil or benzalkonium chloride). The capacity of IL-10 to suppress the effector phase of CHS and DTH supports an important role for this cytokine in the downregulation of type IV immune reactions in vivo. The finding that IL-10 suppresses the induction of DTH, but not of CHS, further suggests that CHS and DTH are related but distinct immune reactions.

Animals↗
PubMed1993

Modulation of murine macrophage function by IL-13.

Activated macrophages are important effector cells for immune response to many parasites and immune responses are strongly modulated in part by the effect of Th cell-derived cytokines on macrophages. Th1-derived cytokines such as IFN-gamma are strong stimulators of macrophage activation, while cytokines produced by Th2 cells, including IL-4 and IL-10, have been shown under some conditions to inhibit macrophage activities associated with inflammatory responses. IL-13, a recently described cytokine produced by Th2 cells, is also capable of down-modulating macrophage activity in a manner similar to that previously described for IL-4. Treatment of activated macrophages with IL-13 reduces the production of inflammatory monokines in response to IFN-gamma or LPS, both potent stimulators of these factors. In addition, IL-13 decreases the production of nitric oxide by activated macrophages. Nitric oxide has been implicated in both macrophage cytotoxicity and macrophage-associated immunosuppression. The suppression of nitric oxide by IL-13 leads to a decrease in parasiticidal activity by activated macrophages. However, our data indicate that IL-13 has pleiotropic effects, while the inflammatory potential of activated macrophages is significantly reduced, the potential of other macrophage subsets is unimpaired. These data indicate that IL-13 could be a potent modulator of immune responses in vivo, with effects that may embrace both macrophage suppressive and macrophage potentiating functions.

Animals↗
PubMed1993

Interleukin 10 protects mice from lethal endotoxemia.

Interleukin 10 (IL-10) decreases production of IL-1, IL-6, and tumor necrosis factor alpha (TNF-alpha) in vitro, and neutralization of IL-10 in mice leads to elevation of the same monokines. We test here whether this monokine-suppressing property of IL-10 confers on it the capacity to protect mice from lipopolysaccharide-induced shock, a monokine-mediated inflammatory reaction. A single injection of 0.5-1 microgram of recombinant murine IL-10 reproducibly protected BALB/c mice from a lethal intraperitoneal injection of endotoxin. This result was obtained whether the IL-10 was administered concurrently with, or 30 min after the injection of endotoxin. The protective effect of IL-10 was reversed by prior injection of neutralizing anti-IL-10 antibodies, and correlated with a substantial decrease in endotoxin-induced TNF-alpha release. These data implicate IL-10 as a candidate for treatment of bacterial sepsis, and more generally as an effective antiinflammatory reagent.

Animals↗
PubMed1993

Interleukin 10 protects mice against staphylococcal enterotoxin B-induced lethal shock.

We investigated the ability of interleukin 10 (IL-10) to protect mice against lethal shock induced by staphylococcal enterotoxin B (SEB). Treatment of mice with IL-10 prevented the death of mice injected with SEB in a dose-dependent manner. IL-10-mediated protection was apparent when administered either prior to or concurrent with SEB but was less effective when administered following SEB injection. This observation indicates that IL-10 is capable of regulating T-cell activation in vivo.

Animals↗