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Biomedical subjects

F Ferreira

Publications and source records attributed to F Ferreira.

At least 37 records · Page 2Linked to original sources
PubMed2002

Second and subsequent lines of chemotherapy for metastatic breast cancer: what did we learn in the last two decades?

Despite almost 30 years of clinical cancer research, the true impact of second and subsequent lines of chemotherapy on the outcome of metastatic breast cancer patients, especially on the duration of survival, is still unknown. In the virtually incurable metastatic setting, issues like quality of life and patients' preferences gain particular relevance. At the turn of the century, in-depth rethinking of the design of clinical trials run in this challenging disease setting appears to be warranted.

Breast Neoplasms↗
PubMed2002

Prevalence of Neospora caninum antibodies in dogs from dairy cattle farms in Parana, Brazil.

Serum samples from 134 dogs from 22 cattle dairy farms in the northern region of Parana State, Brazil, were tested for antibodies to Neospora caninum in an indirect fluorescent antibody test. Antibodies (> or = 1:50) to N. caninum were found in 29 (21.6%) of the 134 dogs, and seropositive dogs were found on 14 (63.6%) of the 22 dairy cattle farrms. The antibody titers of dogs were 1:50 (3 dogs), 1:100 (7 dogs), 1:200 (7 dogs), 1:400 (6 dogs), and > or = 1:800 (6 dogs). The low prevalence (9%) in < 1-yr-old dogs compared with the 2- to 3-fold higher prevalence in older dogs (17-29%) suggests postnatal exposure to N. caninum infection.

Animals↗
PubMed2001

Seroprevalence of Toxoplasma gondii in captive neotropical felids from Brazil.

Seroprevalence of Toxoplasma gondii was determined in 865 captive neotropical felids from 20 states from Brazil, sampled from September 1995 to April 1997. Sera were tested by the modified agglutination test (MAT) using formalin-fixed whole tachyzoites and mercaptoethanol. Antibodies (MAT> or =1:20) to T. gondii were found in 472 of 865 (54.6%) cats: in 45 of 99 (45.9%) jaguarundis (Herpailurus yagouaroundi), in 97 of 168 (57.7%) ocelots (Leopardus pardalis), in 68 of 131 (51.9%) oncillas (L. tigrinus), in 35 of 63 (55.5%) margays (L. wiedii), in 1 of 8 (12.5%) Pampas-cat (Oncifelis colocolo), in 9 of 12 (75.0%) Geoffroys-cat (O. geoffroyi), in 134 of 212 (63.2%) jaguars (Panthera onca), and in 83 of 172 (48.2%) pumas (Puma concolor). Antibody titers were: 1:20 in 27 felids, 1:25 in 142 felids, 1:40 in 6 felids, 1:50 in 292 felids, and > or =1:500 in 5 felids. The high seroprevalence of T. gondii antibodies found in the present study suggested a widespread exposure of neotropical cats to T. gondii in zoos in Brazil. The results warrant an investigation on the mode of exposure and oocyst shedding by neotropical cats.

Agglutination Tests↗
PubMed2001

Risk factors to tick infestations and their occurrence on horses in the state of São Paulo, Brazil.

From December 1998 to March 1999, 40 stud farms were studied in the state of São Paulo, Brazil. During visits to farms, horses reared under grazing conditions were examined for the presence of ticks. On each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the farm (dependent variables). Three tick species were found during the study. Anocentor nitens, Amblyomma cajennense and Boophilus microplus were present on horses from 38 (95%), 20 (50%) and four (10%) farms, respectively. All farms that had A. cajennense or B. microplus infestations also had A. nitens infestations. Only one of the four farms with B. microplus infestations on the horses also had A. cajennense infestations. Two farms had all horses free of ticks. There was a strong association between the presence of infestation by B. microplus on horses and the simultaneous use of a grazing area by cattle and horses (P = 0.000). There was no statistical association between any of the independent variables and the presence or infestation level of A. nitens on the horses (P > 0.20). The presence of A. cajennense was statistically associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.001). A mixed overgrowth pasture means the presence of undesired plants such as bushes and shrubs in the pasture. The presence of high levels of A. cajennense on horses was also associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.026). The regular use of acaricides was statistically associated with the presence of ticks on the horses (P < 0.05), making this procedure a result of the inefficacy of controlling ticks on the farms. The occurrence of human infestation by ticks was statistically associated with the presence of A. cajennense on the horses (P=0.000). The presence of at least one mixed overgrowth pasture on the farm was associated (P = 0.000) to either higher horse densities and to farms that did not mow all the pastures once a year, indicating that mowing all the pastures at least once a year can be considered a protective factor against the presence of mixed overgrowth pastures on the farm, and consequently, against the presence of A. cajennense on the horses.

Animal Husbandry↗
PubMed2001

Thematic roles assigned along the garden path linger.

In the literature dealing with the reanalysis of garden path sentences such as While the man hunted the deer ran into the woods, it is generally assumed either that people completely repair their initial incorrect syntactic representations to yield a final interpretation whose syntactic structure is fully consistent with the input string or that the parse fails. In a series of five experiments, we explored the possibility that partial reanalyses take place. Specifically, we examined the conditions under which part of the initial incorrect analysis persists at the same time that part of the correct final analysis is constructed. In Experiments 1a and 1b, we found that both the length of the ambiguous region and the plausibility of the ultimate interpretation affected the likelihood that such sentences would be fully reanalyzed. In Experiment 2, we compared garden path sentences with non-garden path sentences and compared performance on two different types of comprehension questions. In Experiments 3a and 3b, we constructed garden path sentences using a small class of syntactically unique verbs to provide converging evidence against the position that people employ some sort of "general reasoning" or pragmatic inference when faced with syntactically difficult garden paths. The results from these experiments indicate that reanalysis of such sentences is not always complete, so that comprehenders often derive an interpretation for the full sentence in which part of the initial misanalysis persists. We conclude that the goal of language processing is not always to create an idealized structure, but rather to create a representation that is "good enough" to satisfy the comprehender that an appropriate interpretation has been obtained.

Cognition↗
PubMed2001

Doctors' perceptions of the effects of interventions tested in prospective, randomised, controlled, clinical trials: results of a survey of ICU physicians.

OBJECTIVES: To establish a list of therapeutic interventions considered by intensive care unit (ICU) physicians to have been tested by prospective, randomised, controlled clinical trials (RCTs) in critically ill patients, and to survey the perceptions of the same physicians on the therapeutic effect of these interventions as evaluated by RCT. DESIGN AND SETTING: Self-applied questionnaire in an International Symposium of Intensive Care and Emergency Medicine, Brussels, Belgium. PARTICIPANTS: All 3250 registrants at the symposium. MEASUREMENTS AND RESULTS: There were 527 questionnaires completed, and 446 were suitable for analysis. Respondents were asked to list the therapeutic interventions used in intensive care medicine which they believed have been shown by RCTs to improve survival. Using a 5-point Likert scale, respondents were then asked to rate their assessment of the effectiveness of each intervention they listed and, using a 3-point scale, to select their level of confidence in those assessments. A total of 512 interventions were identified by the respondents as having been tested by RCT. Analysing the 42 interventions quoted more than 12 times, 31 were believed by the respondents to have been shown to have a beneficial effect, and 11 to have a harmful effect. Many of the interventions noted have not in fact been subjected to RCT. CONCLUSIONS: Many interventions that have not been tested by RCT were believed to have been tested; conversely, some interventions actually tested by RCT were not mentioned. Few interventions used in the ICU have actually been shown by RCT to have a positive effect on outcome.

Adult↗
PubMed2001

Molecular and physiological characterisation of a 14-3-3 protein from lily pollen grains regulating the activity of the plasma membrane H+ ATPase during pollen grain germination and tube growth.

A 14-3-3 protein has been cloned and sequenced from a cDNA library constructed from mRNAs of mature pollen grains of Lilium longiflorum Thunb. Monoclonal antibodies (MUP 5 or MUP 15) highly specific against 14-3-3 proteins recognised a 30-kDa protein in the cytoplasmic fraction of many various lily tissues (leaves, bulbs, stems, anther filaments, pollen grains, stigmas) and in other plants (Arabidopsis seedlings, barley recombinant 14-3-3). In addition, 14-3-3 proteins were detected in a microsomal fraction isolated from pollen grains and tubes, and the amount of membrane-bound 14-3-3 proteins as well as the amount of the plasma membrane (PM) H+ ATPase increased during germination of pollen grains and tube growth. No change was observed in the cytoplasmic fraction. A further increase in the amount of 14-3-3 proteins in the microsomal fraction was observed when pollen grains were incubated in germination medium containing 1 microM fusicoccin (FC) whereas the number of 14-3-3s in the cytoplasmic fraction decreased. Fusicoccin also protected membrane-bound 14-3-3 proteins from dissociation after washing with the chaotropic salt KI. Furthermore, FC stimulated the PM H+ ATPase activity, the germination frequency and the growth rate of pollen tubes, thus indicating that a modulation of the PM H+ ATPase activity by interaction with 14-3-3 proteins may regulate germination and tube growth of lily pollen.

14-3-3 Proteins↗
PubMed2001

Misinterpretations of garden-path sentences: implications for models of sentence processing and reanalysis.

Theories of sentence comprehension have addressed both initial parsing processes and mechanisms responsible for reanalysis. Three experiments are summarized that were designed to investigate the reanalysis and interpretation of relatively difficult garden-path sentences (e.g., While Anna dressed the baby spit up on the bed). After reading such sentences, participants correctly believed that the baby spit up on the bed; however, they often confidently, yet incorrectly, believed that Anna dressed the baby. These results demonstrate that garden-path reanalysis is not an all-or-nothing process and that thematic roles initially assigned for the subordinate clause verb are not consistently revised. The implications of the partial reanalysis phenomenon for Fodor and Inoue's (1998) model of reanalysis and sentence processing are discussed. In addition, we discuss the possibility that language processing often creates "good enough" structures rather than ideal structures.

Humans↗
PubMed2001

Evaluation of HER2, p53, bcl-2, topoisomerase II-alpha, heat shock proteins 27 and 70 in primary breast cancer and metastatic ipsilateral axillary lymph nodes.

BACKGROUND: Breast cancer is a heterogeneous disease. Predictive biological markers (BM) of responsiveness to therapy need to be identified. Evaluation of BM is mainly done at the primary site. However, in the adjuvant therapy of breast cancer, the main goal is control of micrometastases. It is still unknown whether heterogeneity in the expression of BM between the primary site and its micrometastases exists. OBJECTIVE: To evaluate the expression of some BM with potential predictive value from the primary breast cancer site and metastatic ipsilateral axillary lymph nodes. PATIENTS AND METHODS: Focality (percentage of positive cells) and intensity staining scores were evaluated for each marker. Freshly cut sections (4 microm) from embedded blocks of breast cancer fixed in formalin or bouin were put onto superfrost slides (Menzel-Gläser). Protein expression was evaluated immunohistochemically (IHC) using monoclonal antibodies against: topo II-alpha (clone KiS1, 1 microg/ml, Roche) with a trypsine pre-treatment (P); HSP27 (clone G3.1, 1/60, Biogenex), HSP70 (clone BRM.22, 1/80, Biogenex) and HER2 (clone CB11, 1/40, Novocastra; without P); p53 (clone D07, 1/750, Dako) and bcl-2 (clone 124, 1/60, Dako) with citrate buffer as P. RESULTS: Overall, the percentage of discordant marker status in the primary tumour and its metastatic lymph nodes was 2% for HER2, 6% for p53, 15% for bcl-2, 19% for topoisomerase II-alpha, 24% for HSP27 and 30% for HSP70. For the subgroup of patients with positive BM in the primary tumour, the percentage of discordance was 6% for HER2, 7% for p53, 14% for bcl-2, 19% for HSP70, 21% for topoisomerase II-alpha and 36% for HSP27. For the subgroup of patients with positive BM in the lymph nodes, the percentage of discordance was 9% for bcl-2, 15% for HER2 and p53, 21% for topoisomerase II-alpha, 22% for HSP27 and 25% for HSP70. CONCLUSIONS: 1) No biological marker had 100% concordant results. 2) Although some discordant cases might be explained by the limitations of the IHC technique, future studies aiming to evaluate the predictive value of BM in the adjuvant therapy of breast cancer should take into account a possible difference in BM expression between the primary and the metastatic sites.

Adult↗
PubMed2001

Influence of the variable number of tandem repeats located in the promoter region of the thiopurine methyltransferase gene on enzymatic activity.

BACKGROUND: The genetic polymorphism of thiopurine methyltransferase (TPMT) activity has a significant relevance in the clinical outcome of patients receiving thiopurine drugs as immunosupressive or anticancer therapies. Apart from several open reading frame mutations unequivocally associated with decreased TPMT activity, a variable number of tandem repeats (VNTR), located within the 5' untranslated region, was recently reported as also affecting gene expression. AIMS AND METHODS: We have characterized both molecularly, by polymerase chain reaction-based techniques, and enzymatically, with an HPLC-based method, a sample of 143 Portuguese Caucasian individuals with the main objective of deepening the study of the TPMT genotype/phenotype relationship. Because two different repeated elements (A and B) do contribute to the overall VNTR variation, we set out to analyze their combined and individual effects on TPMT activity. RESULTS: Allele VNTR*6 was found to be consistently associated with decreased levels of TPMT activity, supporting previous reports that the VNTR does affect levels of TPMT activity, although moderately and in a way not yet clearly defined. Furthermore, individual analysis of the A and B variations suggested that three B repeats was the likely motif influencing gene expression toward decreased transcription. CONCLUSIONS: Our hypothesis, which emphasizes the number of particular motifs within the VNTR internal structure more than the undiscriminated number of repeats as the potential causative factor affecting TPMT activity, needs further support from future studies, namely, from enlarged population samples. However, the knowledge of the VNTR acting mechanism will represent an important step toward fully understanding how the phenotypic variability at the TPMT trait is modulated.

Alleles↗
PubMed2001

Production of capsular polysaccharide of Streptococcus pneumoniae type 14 and its purification by affinity chromatography.

We describe a rapid and efficient method for producing the capsular polysaccharide of Streptococcus pneumoniae by fermentation on tryptic soy broth and purification of this compound by using immobilized soybean lectin as an affinity adsorbent. In principle, the same strategy can be used to produce purified capsular polysaccharides from other streptococcal serotypes by selecting the appropriate lectin adsorbents.

Bacterial Capsules↗
PubMed2001

[Prognosis of mitral commissurotomy. Study of 1134 mitral patients 20 years later].

With a test sample (n = 323), consisting of the answers to an inquiry about the patients with operated mitral stenosis (n = 1134), between 1952 and 1978, in "Hospital Pulido Valente", Lisbon, we compared the group of survivors with the decreased in the relation to sex, age, valvular lesion, type of surgery, valvular area before and after surgery and existence of incompetence. We concluded that mitral stenosis was more frequent in females (4/1), but it had a worse prognosis in males. The lower the age at the time of surgery the better long time prognosis. Digital and instrumental valvulotomy had similar mortality. Valvular incompetence had a worse prognosis and is associated with larger valvular area.

Adolescent↗
PubMed2000

Screening of thiopurine S-methyltransferase mutations by horizontal conformation-sensitive gel electrophoresis.

The genetic polymorphism of thiopurine S-methyltransferase (TPMT) has had a highly significant clinical impact due to its association with individual variation in the toxicity and therapeutic efficiency of thiopurine drugs, which are pharmaceutical agents widely used in the treatment of several kinds of diseases. Until now, ten mutant alleles responsible for TPMT deficiency and several silent and intronic mutations have been described. In this work we present an alternative molecular method for the detection of TPMT alleles. It is an adaptation for horizontal conditions of a conformation-sensitive gel electrophoresis technique. The method has proven to be very efficient as a rapid screening approach for the study of TPMT genetic variability. The method was applied to analyse eight TPMT exons and the corresponding flanking intronic regions in a sample of unrelated healthy individuals from North Portugal. Here we report the allelic frequencies concerning TPMT-deficient alleles and several silent and intronic mutations, including two newly detected intronic polymorphisms: an A (-101) T substitution in intron 3 and a variation involving the number of T nucleotides in a DNA stretch in intron 5. Additionally, we also present data from a sample of 43 children undergoing therapy for acute lymphoblastic leukemia. In this clinical sample we have registered a statistically significant higher frequency for the TPMT*3C allele. This finding raises the question whether the TPMT genotype can contribute to any genetic predisposition for development of the malignancy.

Alleles↗
PubMed2000

A new antibacterial compound from Ibicella lutea.

Ibicella lutea is a 'quasi-carnivorous' plant that grows wild in Uruguay where it is used in popular medicine as an antiseptic for eye and skin infections. In an earlier screening, it showed a broad antibacterial spectrum. From the chloroform extract of the plant the main antibacterial compound has now been isolated and identified by several MS and NMR methods as a new compound, 11-O-(6'-O-acetyl-beta-D-glucopyranosyl)-stearic acid.

Anti-Infective Agents↗
PubMed2000

Scoring systems for assessing organ dysfunction and survival.

Sepsis is an ongoing disease process carrying a high risk of organ failure and death. Scoring systems to determine disease severity and risk of mortality may be useful in patient management and clinical trial enrollment, although the role of either type of score in the determination of admission or discharge criteria or in decisions relating to the continuation or withholding of treatment remains controversial. General scoring systems have been developed to quantify the severity of illness and the risk of mortality in ICU patients. Ideally, these should be customized before use in patients with septic shock, but in general noncustomized models are used, and this potential limitation should be acknowledged. Prognostic scores are remarkably reliable at predicting outcome in groups of patients and give an indication of severity of disease on admission, but they are unable to provide detail on how a patient is responding to treatment or on the disease progression. Organ function scores, however, can be assessed repeatedly and used to define a patient's progress. This approach can thus be used to evaluate individual patient care, to identify patients for enrollment in clinical trials or epidemiologic analyses, and to assess morbidity measures in clinical trials of new interventions. Organ dysfunction scores are just that, descriptors of organ dysfunction, and although high values correlate well with mortality, prognostication is not their prime aim; organ dysfunction scores and outcome prediction scores should rather be viewed as complementary systems in the description of ICU populations.

APACHE↗
PubMed2000

Life cycle of the tick Haemaphysalis leporis-palustris (Acari: Ixodidae) under laboratory conditions.

The life cycles of two separate populations (colonies A and B) of the rabbit tick, Haemaphysalis leporis-palustris, were studied under laboratory conditions. Domestic New Zealand rabbits, Oryctolagus cuniculus, and wild rabbits, Sylvilagus brasiliensis, were used as hosts for ticks from colony B and only O. cuniculus rabbits were used as hosts for ticks from colony A. Developmental periods were observed in an incubator at 27+/-1 degrees C and RH 90+/-5%. Larvae from colonies A and B fed for 8.0+/-3.7 days and 8.5+/-1.3 days, respectively, on O. cuniculus. On S. brasiliensis larvae from colony B fed for 7.2+/-1.3 days. Nymphs from colony A fed for 8.1+/-1.4 days on O. cuniculus and nymphs from colony B fed for 8.1+/-1.0 days on S. brasiliensis. Only one engorged nymph from colony B was recovered from O. cuniculus. Females from colony A fed for 20.9+/-5.9 days on O. cuniculus and females from colony B fed for 18.6+/-2.4 days on O. cuniculus and 18.7+/-3.7 days on S. brasiliensis. Engorged larvae from colony A required 13.7+/-3.7 days to molt while engorged larvae from colony B required 11.8+/-3.0 and 11.5+/-1.8 days to molt, after having fed on O. cuniculus and S. brasiliensis, respectively. Engorged nymphs from colonies A and B required 16.3+/-1.9 days and 14.7+/-1.4 days to molt, respectively. Engorged females from colonies A and B required 4-7 and 3-5 days, respectively, to start oviposition. Mean egg incubation periods lasted for 33-34 days. For ticks from colony B, host species accounted for significant differences (p < 0.05) in larval and nymphal feeding periods, oviposition weights and CEIs. Significant differences (p < 0.05) between the two colonies when ticks fed on O. cuniculus were observed for larval and nymphal feeding and premolt periods, engorged female and oviposition weights and conversion efficiency indexes (CEI). S. brasiliensis were always a more suitable host for H. leporis-palustris than O. cuniculus. Significantly more larvae and nymphs engorged and molted when fed on S. brasiliensis (p < 0.001). Females fed S. brasiliensis were more successful to lay fertile eggs and showed the highest engorged and egg mass weights, and the highest CEIs. Data of H. leporis-palustris fed on wild rabbits (one of its natural host species) are reported for the first time.

Animals↗