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Biomedical subjects

A Lopes

Publications and source records attributed to A Lopes.

At least 19 recordsLinked to original sources
PubMed2006

Electrochemical degradation applied to the metabolites of Acid Orange 7 anaerobic biotreatment.

The electrochemical oxidation of the biotic degradation products of the textile dye C.I. Acid Orange 7 (AO7) was achieved using a boron doped diamond electrode (BDD). Tests were performed with model solutions of the biotic degradation products, sulphanilic acid (SA) and 1-amino-2-naphthol (AN), and also with real effluents obtained in experiments carried out in an up-flow anaerobic sludge blanket (UASB) reactor, fed with a simulated textile effluent containing AO7, working in mesophilic or thermophilic conditions. Bulk electrolysis was studied using two different supporting electrolytes - NaCl and Na(2)SO(4). The influence of initial metabolite concentration and current density on the electrodegradation rates of the biotic products was investigated. For the UASB effluents, oxidation tests were carried out for different electrolytes and at different current densities. Samples were collected at pre-selected intervals and absorbance measurements, chemical oxygen demand (COD) and total organic carbon (TOC) tests and high performance liquid chromatography (HPLC) analysis were performed. Results have shown an almost complete elimination of the persistent pollutants and a COD removal higher than 70% for both AN and SA. For the UASB effluents, COD removals between 45% and 90% and TOC removals varying from 19% to 41% were obtained.

Algorithms↗
PubMed2005

A prospective randomised controlled trial of intermittent self-catheterisation vs. supra-pubic catheterisation for post-operative bladder care following radical hysterectomy.

OBJECTIVE: To determine the potential benefits of ISC (intermittent self-catheterisation) over SPC (supra-pubic catheterisation) in the post-operative bladder care of women following radical hysterectomy. METHODS: A prospective randomised controlled trial of women treated by radical hysterectomy for early stage cervical cancer. RESULTS.: 40 women were recruited to the study, 21 to ISC and 19 to SPC. All patients randomised to ISC were able to learn the technique of ISC satisfactorily following a period of pre-operative training. The day 3 and day 5 positive CSU (catheter specimen of urine) rate was significantly higher in the ISC group (42% and 63%) compared to the SPC group (6% and 18%), P = 0.05 and P = 0.004, respectively). Eight of 17 patients randomised to SPC (47%) documented having symptoms/problems arising from the SPC site of which 4 (23%) were shown to have a positive wound swab. There was no significant difference in length of period for bladder care between the two groups, P = 0.83. However, there were significant differences in patient acceptability (P = 0.009), freedom to lead a normal life (P = 0.000), disturbance at night (P = 0.006) and patient anxiety/embarrassment (P = 0.005) between the two groups. CONCLUSIONS: Patients are able to learn the technique of ISC without difficulty. Despite a greater urinary tract infection rate, the high incidence of SPC site problems can be avoided by use of ISC. The technique of ISC was seen to be more acceptable to patients allowing fewer disturbances at night, greater freedom to lead a normal life during the day and less anxiety/embarrassment compared to SPC.

Adult↗
PubMed2005

Effect of stage of follicular growth during superovulation on developmental competence of bovine oocytes.

The final steps of oocyte capacitation and maturation are critical for embryonic development but detailed information is scarce on how the oocyte is affected during this period. In this study, 2033 oocytes were collected from 106 superovulated cattle at four different time points before ovulation. Follicular characteristics were measured and oocyte quality was assessed by morphology, mRNA expression of eight marker genes or developmental ability after in vitro/in vivo maturation and subsequent in vitro fertilization and culture. Approaching ovulation, expected increases in follicular size and cumulus expansion suggested progression of oocyte maturation. No differences were found in the expression patterns of analyzed genes, except for heat-shock-protein (Hsp) that was lower in in vivo matured oocytes collected shortly before ovulation. Oocytes collected at this time also had higher developmental ability measured as blastocyst rates (57.6%) after in vitro production while no differences were found between oocytes recovered earlier at the first three time points (39.3-41.5%). We conclude that oocytes recovered late in the preovulatory period are more developmentally competent than oocytes recovered at the pre-capacitation and the capacitation period, probably due to the former having matured in vivo. However, a precisely defined time for aspirating immature oocytes for subsequent in vitro development seems not to be crucial.

Animals↗
PubMed2005

Prognostic and predictive value of the thymidylate synthase expression in patients with non-metastatic colorectal cancer.

AIMS: To assess the value of thymidylate synthase (TS) expression as a predictive factor in the efficacy of adjuvant chemotherapy in colorectal cancer, as well as its independent prognostic value for survival. METHODS: We studied 114 high risk colorectal carcinoma patients (high risk stage II and stage III), distributed in two treatment groups: surgery alone (61 patients) or surgery followed by 5-FU-based chemotherapy (53 patients). TS protein expression in the tumour tissue was assessed by immunohistochemistry. RESULTS: In the surgery alone subgroup, overall survival (OS) at 5 years were 77.5% for the patients with low TS expression, against 57.7% for the patients with high TS expression (p=0.006). Among patients with low TS, there was no difference in OS as a result of whether adjuvant chemotherapy was carried out or not (65.8 vs 77.5%, p=0.29). Among the patients with high TS, there was a significant gain in OS in favor of chemotherapy (87.8 vs 57.7%, p=0.04). Analyzing the complete sample, TS expression was not shown as an independent prognostic factor for survival in the multivariate analysis. CONCLUSIONS: The immunohistochemical TS expression may be used for selecting patients for better adjuvant chemotherapy protocols. In this sample, TS expression was not an independent prognostic factor for survival.

Aged↗
PubMed2005

Comparison of pre-treatment CYFRA 21 - 1 and SCC-Antigen assay in primary cervical carcinoma - a preliminary report.

CYFRA21 - 1, a fragment of cytokeratin19, has been widely assessed as a serum marker of squamous malignancies. Previous studies using CYFRA21 - 1 and SCC-Antigen have shown mixed results but have indicated a better predictive prognostic value for SCC-Ag as compared to CYFRA21-1. The aim of our prospective, observational, pilot study was to evaluate the role of CYFRA21-1 and SCC-Ag in primary cervical carcinoma. Pre-operative serum CYFRA21-1 and SCC-Ag were measured (n = 14) in women with cervical carcinoma and correlated with staging, clinico-pathological parameters and prognostic data. Logistic regression analysis with CYFRA 21 - 1 test status (positive or negative) as a dependent variable showed that nodal metastases (p = 0.001) and lymphovascular space invasion (LVSI) (p = 0.005) were significant predictors, whereas stage and SCC-Ag levels were not significant. There was also no statistically significant correlation between SCC-Ag and CYFRA21-1 levels. If larger studies confirm these preliminary results, the option of laparoscopic surgical staging in patients with raised CYFRA21-1 levels could be considered.

Adenocarcinoma↗
PubMed2004

The role of human papillomavirus type 16 and the fragile histidine triad gene in the outcome of cervical neoplastic lesions.

The presence of high-risk human papillomavirus, loss of heterozygosity on chromosome 3p and fragile histidine triad gene expression were assessed as potential markers of cancer and CIN progression in 83 cervical cancers and 74 cervical intraepithelial neoplasia grade 1 lesions. Human papillomavirus type 16 was an indicator of vascular involvement in cancers. Loss of heterozygosity, especially in the fragile histidine triad gene intron 5, was an indicator of high-grade tumours, greater tumour depth and lymph node involvement. Abnormal fragile histidine triad gene expression was more frequent in cervical intraepithelial neoplasia grade 1 lesions with increased risk of disease progression.

Acid Anhydride Hydrolases↗
PubMed2004

Pelvic exenteration and sphincter preservation in the treatment of soft tissue sarcomas.

BACKGROUND: Pelvic sarcomas are rare and there are very few effective therapeutic alternatives. A complete resection is considered the main factor associated to a good prognosis, which justifies the employment of a pelvic exenteration (PE) in selected cases. METHODS: Between 1980 and 2000, 96 PE were performed, nine of which were for sarcomas. The clinical characteristics, surgical and anatomopathological aspects and the patients' evolution were described. RESULTS: The median follow-up time was 24 months (ranging from 1 to 57 months). In relation to the sphincters preservation, at least one sphincter was preserved in five patients. There were two post-operative deaths. In the last follow-up, six patients were alive without any evidence of the disease. CONCLUSION: Pelvic exenterations should be performed for the treatment of selected cases of locally advanced pelvic sarcomas. Sphincter preservation may be performed, provided that oncological resection principles are obeyed.

Adult↗
PubMed2003

Contralateral groin node metastasis following ipsilateral groin node dissection in vulval cancer: a case report.

BACKGROUND: The majority of vulval cancers are of the squamous cell type. Current operative management strategies are based on modifications of radical vulvectomy and groin node dissection, enabling a more individualised and conservative approach to surgery. This has led to interesting dilemmas regarding the most appropriate management in certain individuals. CASE: We describe a case of a contralateral recurrence following unilateral groin node dissection for vulval cancer, with an initial single microscopically positive node. The patient did not receive adjuvant treatment. Evidence regarding the safety of this approach is discussed. CONCLUSION: The subject remains controversial, and further such cases should be recorded in the literature in order to gather more information on this difficult problem.

Aged↗
PubMed2001

Human papillomavirus as a prognostic factor in carcinoma of the penis: analysis of 82 patients treated with amputation and bilateral lymphadenectomy.

BACKGROUND: Many studies have tried to identify prognostic factors to guide the selection of patients at high risk for metastases in penile carcinoma. The authors evaluated human papillomavirus (HPV) status with respect to clinical features, incidence of metastases, and prognosis of penile carcinoma. METHODS: Human papillomavirus DNA was detected using the polymerase chain reaction on paraffin embedded material from 82 patients with penile carcinoma. The following variables were recorded: age, marital status, clinical staging, tumor surgery extension, histologic grade, tumor thickness, lymphatic and venous embolization, corpora cavernosa and corpus spongiosum infiltration, urethral infiltration, mononuclear and eosinophilic infiltrate, and lymph node spread. Follow-up ranged from 0.1 to 453 months. RESULTS: Human papillomavirus DNA was detected in 30.5% (25 of 82) of samples. HPV-16 was the most frequent type detected (13 of 25, 52%). Human papillomavirus DNA positive tumors had less lymphatic embolization by neoplastic cells than HPV negative ones (P = 0.007). The logistic regression revealed that only lymphatic embolization was related to HPV status. There was no difference, however, between HPV DNA negative and HPV DNA positive patients according to presence of lymph node metastases (P = 0.386). No difference was found in the 10-year survival rate (68.4% vs. 69.1%; P = 0.830) between the two groups. CONCLUSIONS: These data suggest that HPV status does not influence prognosis in invasive penile carcinoma.

Adult↗
PubMed2001

Reproducibility of neurophysiological and myometric measurement in the ulnar nerve-abductor digiti minimi system.

Reliability in strength and neurophysiological measurements is important in evaluating progression of neuromuscular diseases. No data are available on the variability of neurophysiological parameters as compared with maximal voluntary isometric contraction (MVIC) in the same muscles, in healthy subjects. A control population of 26 healthy subjects was studied twice on different days. We evaluated the reliability of neurophysiological parameters obtained from bilateral ulnar nerve stimulation, recording the response over the abductor digiti minimi (ADM) muscle, including distal motor latency, compound muscle potential amplitude and area, F-wave frequency and mean F-wave latency, and the derived neurophysiological index that we have described previously. MVIC force was measured in each session in both ADM muscles. The variances between the grouped data obtained in the two recording sessions were identical, indicating a low intrinsic variability with this experimental methodology. Comparison of the mean values obtained in the two sessions revealed no statistically significant differences. The reliability of these neurophysiological and strength measurements in the same nerve/muscle system suggests they may be useful in comparing the dynamics of weakness and neurophysiological change in neuromuscular disease.

Adult↗
PubMed2001

Clinicopathologic features and human papillomavirus dna prevalence of warty and squamous cell carcinoma of the penis.

Squamous cell carcinoma (SCC) accounts for 95% of penile malignant neoplasms. A subtype of SCC, named warty carcinoma (WC), is a morphologically distinct verruciform tumor with features of human papillomavirus (HPV)-related lesions. Descriptions of the behavior and histologic features of this tumor are scarce in the literature. The aim of this report is to analyze the clinicopathologic features and HPV deoxyribonucleic acid status in 60 SCCs and 11 WCs. The mean patient age was 46.5 +/- 15.9 years for WC and 52.6 +/- 12.4 years for SCC. No significant differences in age (p = 0.154) and clinical staging (T, p = 0.649; N, p = 0.497) between the two groups of tumors were found. When compared with SCCs, WCs exhibited less lymphatic embolization (p = 0.001), nodal metastasis (p = 0.019), and corpora cavernosa and corpus spongiosum infiltration (p = 0.040). Lymph node metastases were found in 34 of 60 SCC patients (56.7%) and in two of 11 WC patients (18.2%). No patients with WC tumors died of the disease compared with 19 of 60 (5-year specific survival, 66.0%) in the SCC group (p = 0.032). HPV deoxyribonucleic acid was more likely to be associated with WC (five of 11, 45.5%) than SCC (16 of 60, 26.7%), although significance was not reached (p = 0.209). The results suggest that WC is less aggressive and confers a better prognosis than typical SCC of the penis.

Adult↗
PubMed2001

Genetic epidemiology of fecal egg excretion during Schistosoma mansoni infection in an endemic area in Minas Gerais, Brazil.

There is considerable variation in the level of fecal egg excretion during Schistosoma mansoni infections. Within a single endemic area, the distribution of egg counts is typically overdispersed, with the majority of eggs excreted coming from a minority of residents. The purpose of this study was to quantify the influence of genetic factors on patterns of fecal egg excretion in a rural study sample in Brazil. Individual fecal egg excretions, expressed in eggs per gram of feces, were determined by the Kato-Katz method on stool samples collected on three different days. Detailed genealogic information was gathered at the time of sampling, which allowed assignment of 461 individuals to 14 pedigrees containing between 3 and 422 individuals. Using a maximum likelihood variance decomposition approach, we performed quantitative genetic analyses to determine if genetic factors could partially account for the observed pattern of fecal egg excretion. The quantitative genetic analysis indicated that between 21-37% of the variation in S. mansoni egg counts was attributable to additive genetic factors and that shared environment, as assessed by common household, accounted for a further 12-21% of the observed variation. A maximum likelihood heritability (h2) estimate of 0.44 +/- 0.14 (mean +/- SE) was found for the 9,604 second- and higher-degree pairwise relationships in the study sample, which is consistent with the upper limit (37%) of the genetic factor determined in the variance decomposition analysis. These analyses point to the significant influence of additive host genes on the pattern of S. mansoni fecal egg excretion in this endemic area.

Adolescent↗
PubMed2001

[Time's paradigm in primary angioplasty].

The use of primary angioplasty in the treatment of acute myocardial infarction (AMI), as opposed to fibrinolysis, is well established, as long as performed by an experienced team. The benefits are "time-dependent", hense the rational for the sentence "Time is Muscle". It is very important to assess the time factor, mainly if the therapeutic option is primary angioplasty, since it is necessary to set up a full range of conditions related to this type of specific treatment (human, material and logistical). In the current study was analysed the in and out of hospital time sequence of 99 patients with AMI that underwent primary PTCA during the year of 1999. The main goal was to assess if the performance of this procedure outside regular working hours could have any significant impact on the "time of in-hospital ischemia". The different time durations were prospectively recorded according to a protocol that was previously established and filled for each patient by the lab team. The authors conclude that: a) the average in-hospital time delay in the treatment of AMI by PTCA was not significantly influenced by the fact that the procedure was performed outside the regular working hours of the lab; b) the main component of the "ischemic in hospital time" corresponds to the time between the patient's admission and the decision making time for PTCA. Although the average decision making time for PTCA is too long and must be optimized, the average total in hospital ischemic time (99-105 minutes) compares favorably with other previous reports in the literature.

Aged↗
PubMed2000

In vitro release studies of methylmethacrylate liberation from acrylic cement powder.

Bone cement or polymethylmethacrylate (PMMA) is commonly used for anchoring cemented prosthesis to the bone. Cytotoxic effect of culture media exposed to PMMA powder may be related with long term problems associated with acrylic cement application, being the monomer (methylmethacrylate) one of the cement's component partly responsible for the cytotoxic effect. The present work reports the studies of monomer release from acrylic bone cement powder under different experimental conditions: setting time of PMMA (in solution and air) and different culture media composition. High-performance liquid chromatography was used for the determination of residual monomer. Mathematical models were applied to experimental dissolution data revealing that monomer release is lightly affected by the studied variables. The monomer release seems to be a surface phenomena, suggesting that the possible actions of monomer will mainly be due to the initial loss of non polymerized monomer rather than to further depolymerization of the already polymerized cement.

Bone Cements↗
PubMed2000

Iliac nodal metastases from carcinoma of the penis treated surgically.

OBJECTIVE: To evaluate survival in patients with metastatic iliac nodal involvement from carcinoma of the penis. PATIENTS AND METHODS: Thirteen patients with metastases to the iliac nodes were selected from 68 with squamous cell carcinoma of the penis who had undergone amputation and bilateral ilio-inguinal lymphadenectomy. The 1978 Tumour-Nodes-Metastasis system was used for staging. Deep and superficial lymph nodes were removed during the inguinal procedure. Lymph nodes below the common iliac artery (external and obturator) were removed and histologically evaluated for the presence of metastases. RESULTS: The mean (median, range) follow-up was 55.5 (8. 8, 0.3-235) months, at the end of which five patients were free of cancer, seven had died from cancer or treatment-related complications and one was lost to follow-up. Four of the five survivors had metastases to only one iliac lymph node. CONCLUSION: Ilio-inguinal lymphadenectomy may have a significant role in increasing the survival of patients with metastases to only one iliac lymph node.

Adult↗
PubMed2000

Association between high-risk HPV types, HLA DRB1* and DQB1* alleles and cervical cancer in British women.

Cervical scrapes from 116 British women referred with cervical cancer were tested for the presence of high oncogenic risk human papillomavirus (HPV) genotypes (HPV(hr)). Ninety-four per cent of the scrapes had one or more of these virus types and 66% were HPV16-positive. HPV18 was more frequent in adenocarcinoma. No evidence was found for an increased cancer risk associated with the HPV16 E6 350G variant. The HLA DRB1* and DQB1* alleles in these women and in 155 women with normal cytology and negative for HPV(hr) DNA were compared. DQB1*0301 alone (2P = 0.02) and in combination with DRB1*0401 (2P = 0.02) was found to be associated with cervical cancer. This was more marked in cancers positive for HPV types other than HPV16. In contrast, DRB1*1501 alone and in combination with DQB1*0602 was not significantly elevated in cancers overall, but did show some excess in HPV16-positive cancers (2P = 0.05), associated with HPV16-positive cervical cancers. Taking all cancers together, a marginally significant protective effect was found for DQB1*0501 (2P = 0.03) but no protective effect could be seen for DRB1*1301.

Adenocarcinoma↗