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L Silva

Publications and source records attributed to L Silva.

At least 19 recordsLinked to original sources
PubMed2006

Ecotoxicological evaluation of cork-boiling wastewaters.

Toxicity tests with Vibrio fischeri, Daphnia magna, and Lemna minor were used to evaluate acute and chronic toxicity of cork-boiling wastewaters and correlation analysis was performed with physicochemical parameters. Acute toxicity values (EC(50)) ranged from 2.3% to 24.2% in the Microtox test and from 4.4% to 29.5% in the Daphnia test. According to these values, 78% of the samples were classified as acutely toxic to the most sensitive species (V. fischeri). Significant correlation was obtained between EC(50) and chemical oxygen demand, biochemical oxygen demand after 5 days, total organic carbon, tannin and lignin and total solids. No significant correlation was found between the two acute tests. The D. magna chronic test showed significant differences between all tested concentrations and the control, with an EC(50) of 0.32%. An EC(50) value of 26.0% was calculated for L. minor. For the analysis of cork-boiling wastewater toxicity and routine biomonitoring, the use of the Microtox test is suggested, to afford greater environmental protection.

Aliivibrio fischeri↗
PubMed2006

Sentinel lymph node biopsy in multicentric breast cancer. The experience of the European Institute of Oncology.

AIM: To present our experience with sentinel lymph node biopsy (SLNB) performed in patients with multicentric breast cancer. METHODS: Between May 2001 and May 2004, 42 patients with multicentric breast cancer and a clinically negative axilla underwent lymphatic mapping either by a single subareolar (n = 25) or a double peritumoral/subdermal injection (n = 17) of 99Tc-HSA nanocolloids. The sentinel lymph node (SLN) was evaluated by intraoperative frozen section and axillary dissection was performed only in case of positive SLN. RESULTS: Mean age was 49 years (range 25-78). Mean number of SLNs identified by lymphoscintigraphy was 1.36 (range 1-5) and mean number of SLNs removed at surgery was 1.55 (range 1-5), with an identification rate of 100%. The mean number of hot spots identified by lymphoscintigraphy was similar in patients who underwent single or double injections (1.36 and 1.35, respectively). In 21 of 42 patients the SLN was positive, and in seven of these 21 patients the SLN was the only positive node. After a median follow-up of 24 months no overt axillary metastases occurred in patients with negative SLN. CONCLUSIONS: The number of SLNs is not dependent on the number and site of injections. SLNB is our standard procedure for nodal staging in patients with multicentric breast cancer and a clinically negative axilla.

Adult↗
PubMed2006

Reproductive response in suckling Corriedale ewes to the ram effect during the non-breeding season: effect of postpartum condition and the use of medroxyprogesterone priming.

The response to the ram effect and the use of progestagen priming was studied in postpartum suckling Corriedale ewes. Two experiments were carried out during the non-breeding season. In experiment 1, the effectiveness of the ram effect to induce fertile oestrus in postpartum ewes was determined. While no significant differences in the frequency of ewes in oestrus were found, the overall conception rate was significantly higher in ewes that were weaned at least 6 months before the study started (63.3%) than in 60-90 days postpartum ewes (45.3%, p < 0.01). In experiment 2, the influence of medroxyprogesterone acetate priming on the response to the ram effect in suckling Corriedale ewes was determined. The frequency of ewes in oestrus and conception rate between ewes that remained unprimed and 6-days-primed ewes were similar. We conclude that it is possible to induce oestrus in postpartum suckling Corriedale ewes using the ram effect during the non-breeding season and that the use of progestagen priming seems to be ineffective in improving the response of postpartum ewes to the ram effect.

Animals↗
PubMed2005

Outbreaks of cholera-like diarrhoea caused by enterotoxigenic Escherichia coli in the Brazilian Amazon Rainforest.

The relationship between enteropathogens and severe diarrhoea in the Brazilian Amazon is poorly understood. In 1998, outbreaks of acute diarrhoea clinically diagnosed as cholera occurred in two small villages localized far from the main cholera route in the Brazilian rainforest. PCR was performed on some enteropathogens and heat-labile (LT) and/or heat-stable (STh) toxin genes, the virulence determinants of enterotoxigenic Escherichia coli (ETEC), were detected. Further characterization of ETEC isolates revealed the presence of two clones, one from each outbreak. One presenting serotype O167:H5 harboured LT-I and STh toxin genes and expressed the CS5CS6 colonization factor. The other, a non-typeable serotype, was positive for the LT-I gene and expressed the CS7 colonization factor. The current study demonstrates the importance of molecular diagnosis in regions such as the Amazon basin, where the enormous distances and local support conditions make standard laboratory diagnosis difficult. Here we also show that the mis-identified cholera cases were in fact associated with ETEC strains. This is the first report of ETEC, molecularly characterized as the aetiological agent of severe diarrhoea in children and adults in the Brazilian Amazon Rainforest.

Adolescent↗
PubMed2004

Ewe effect: endocrine and testicular changes in experienced adult and inexperienced young Corriedale rams used for the ram effect.

Changes in LH, FSH, and testosterone concentrations, testicular firmness and resilience, and scrotal circumference were monitored in 16 Corriedale rams (8 experienced adult and 8 inexperienced young) for 20 days during which they were used to stimulate ewes. The experiment was conducted during November (mid-non-breeding season). Increases (P<0.05) were observed in LH and testosterone concentrations and in testicular firmness and resilience during the first 4 days when rams were in permanent contact with estrual ewes. During the following 13 days, when rams were in contact with non-estrual ewes (i.e. initially estrual ewes were no longer in estrus), LH and testosterone concentrations decreased. When initially anestrous ewes exhibited estrus 17 to 20 days later, concentrations of testosterone increased. Testicular firmness and resilience remained high throughout the period. We conclude that: (1) rams used to stimulate anestrous ewes show an increase in LH and testosterone concentrations beginning at 12 h after joining, and greater concentrations are maintained while estrual ewes and mating are allowed; and (2) estrous and mating activity are probably the most important stimuli for the increase in hormone concentrations.

Animals↗
PubMed2003

Differential characteristics of heart transplantation in patients older than 60 years.

BACKGROUND: The effect of advanced age on the results of heart transplantation (HTx) is still controversial. The few articles addressing this issue have not been conclusive, due to either short follow-up periods or small numbers of patients. METHODS: We present a retrospective study of 560 HTx which were divided into group A, including patients of 60 or less years at HTx (n=465, 83%), and group B, of 95 recipients older than 60 years. A subgroup of the latter, named B1, includes 24 patients older than 65. More than 100 recipient, donor and surgical procedure variables were analyzed for their impact on actuarial survival and incidence of common causes of posttransplant morbidity and mortality during a follow-up period longer than 10 years. RESULTS: Group B showed a lower number of acute rejection episodes than group A, (1.53+/-1.87 versus 1.96+/-1.81, P<.04). Both groups showed a similar incidence of infection episodes, malignancies or graft vasculopathy, but older patients experienced fewer viral infections than younger ones (9% in group A versus 18% in group B, P<.05). Log-rank test showed a trend to shorter survival in group B (P=.08), a disadvantage that reached significance (P=.01) among patients older than 65 years. CONCLUSIONS: Patients who were older than 60 at HTx displayed a lower incidence of acute rejection episodes and viral infections, but a trend toward shorter long-term survival. This disadvantage in prognosis was statistically significant among recipients older than 65 years.

Actuarial Analysis↗
PubMed2001

The feasibility of hand-assisted laparoscopic aortic bypass using a low transverse incision.

BACKGROUND: Hand-assisted laparoscopy can be used to perform aortoiliac reconstructive procedures. This study aimed to evaluate the safety and feasibility of a hand-assisted aortofemoral bypass in patients with occlusive disease using a low abdominal transverse incision to reduce postoperative respiratory problems. METHODS: In 18 patients, a modified Pfannenstiel incision was performed. A hand-assist device was inserted, and the aorta was exposed using transperitoneal laparoscopy. Tunneling was performed under laparoscopic control. The anastomosis was always performed proximally to the inferior mesenteric artery. In three patients, the proximal anastomosis had to be performed laparoscopically. The indication for surgery was occlusive disease in 16 patients and a combination of an aneurysm and aortoiliac occlusion in 2 patients. RESULTS: Conversion was required in one patient (1/18). In 13 patients (13/18), the total operating time did not exceed 180 min, and 61% of the patients (11/18) could be discharged by postoperative day 5. None of the patients died perioperatively (0/18). Complications were observed in six patients (6/18). Only one of these patients had respiratory problems (1/18). The remaining five patients had local complications such as wound healing problems. The anastomosis was sutured laparoscopically in three patients (3/18). CONCLUSIONS: Hand-assisted laparoscopy can be performed safely using a low transverse abdominal incision. In our experience this laparoscopic access can reduce the incidence of postoperative respiratory problems and incision-related complications.

Aged↗
PubMed2000

Allograft loss in renal transplant recipients with Fabry's disease and activated protein C resistance.

INTRODUCTION: Fabry's disease is associated with an increased incidence of thrombotic events and rejection. Spontaneous thrombosis of a functioning cadaveric renal allograft in a recipient with Fabry's disease prompted prospective evaluation of all transplant candidates with Fabry's disease for hypercoagulability. MATERIALS AND METHODS: Transplant candidates with Fabry's disease were tested for hypercoagulability, analyzed for HLA-type and ABO group, and comorbid conditions suggestive of hypercoagulability. RESULTS: A unique association of Fabry's disease with activated protein C Resistance was documented in a cohort of Caucasian male renal transplant recipients with Fabry's disease. Four of five patients were blood group A and had no significant comorbid conditions suggestive of hypercoagulability. The resistance to activation of protein C (APCR)(+) patients shared HLA loci-B8 and Dr3, although the APCR(-) patients shared HLA loci-B27 and -B38. CONCLUSIONS: Due to the observed increase in the incidence of APCR in our Fabry's cohort, we suggest screening all patients with Fabry's disease for APCR. Because factor V and factor Va receptors are found on vascular endothelium and peripheral blood monocytes, APCR in the presence of Fabry's disease may be a nonimmunological stimulus for rejection. Analysis of HLA typing in patients with Fabry's disease may further elucidate HLA-based association of Fabry's disease and resistance to activated protein C with the risk of thrombosis and rejection.

ABO Blood-Group System↗
PubMed2000

Evidence for an involvement of vitellogenin in the steroidogenic activity of rainbow trout (Oncorhynchus mykiss) vitellogenic oocytes.

In vivo and in vitro the concentration of vitellogenin (VTG) inside the oocyte can alter VTG production by the liver, modulating the synthesis of 17beta-estradiol (E(2)) by the ovary. To gain a greater insight into this mechanism, the in vitro production of free and conjugated testosterone (T), E(2), and androstenedione (A) by rainbow trout oocytes from the early and middle vitellogenic stage was measured by radioimmunoassay. There was a decreased E(2) production that was greater in September (40%) than October (30%), by the oocytes incubated with the vitellogenic fraction. The production of E(2) conjugated as glucuronide was lower than sulfate (P < 0.05), but similar in control and VTG-incubated oocytes. Levels of free T increased from September to October, and conjugates were both produced at low levels, and no differences were detected between control and incubated VTG oocytes. The decreased synthesis of E(2) by oocytes incubated with VTG was not followed by an increase in the amount of T or conjugated E(2), because there were no differences under the two circumstances. However, there was a reduced synthesis of A with oocytes producing low levels of E(2). These results suggest that the presence of high levels of VTG in the oocyte suppresses the synthesis of A and E(2), affecting the activities of the enzymes C17,20 lyase and aromatase and probably interfering with the heme protein cytochrome P450 which in the ovary catalyses C 17,20 lyase (P450 c17) and aromatase (P450 arom).

Androstenedione↗
PubMed2000

Prevention of group B streptococcus early-onset neonatal sepsis: comparison of the Center for Disease Control and prevention screening-based protocol to a risk-based protocol in infants at greater than 37 weeks' gestation.

OBJECTIVE: To compare the Center for Disease Control consensus guidelines' screening-based strategy to a risk-based strategy as regards the incidence of early-onset group B streptococcus (GBS) infection among term infants. STUDY DESIGN: A cohort of university hospital prenatal clinic mother-infant pairs who were screened for GBS at 35 to 37 weeks' gestation were compared to a matched control group of unscreened mother-infant pairs from the outreach satellite prenatal clinics who delivered at the same institution during the same time period. GBS screening was carried out with rectovaginal cultures plated on selective media. GBS-positive women received antimicrobial prophylaxis in labor whereas women of unknown GBS status were only treated intrapartum if they had a risk factor for GBS infection. Principal outcome variables included incidence of cases of neonatal early-onset GBS sepsis (blood, urine, or cerebrospinal fluid positive for GBS), incidence of cases of strongly suspected GBS sepsis (culture negative), and incidence of neonatal sepsis with non-GBS organisms. RESULTS: There were 3164 screened mother-infant pairs who were compared to 2684 unscreened pairs. The incidence of GBS carriage was 13.3%. A random sample of 420 screened women were compared to a matched sample of 407 women of unknown GBS carrier status for characterization of demographics and risk factors. No cases of documented GBS sepsis occurred in the infants of the screened women, but four cases occurred among the infants of the women who did not undergo screening (incidence 1.5/1000) (p = 0.04), only one of whom had a risk factor for GBS infection. Cases of suspected but culture negative sepsis were not more common in the screened population when compared to the unscreened. There was one case of Escherichia coli sepsis in an infant of a mother in the unscreened group. CONCLUSIONS: GBS screening at 35 to 37 weeks, with intrapartum antimicrobial prophylaxis of carriers, decreased the incidence of neonatal early-onset GBS sepsis and appears to have advantages over treatment based on risk factors alone in term infants.

Clinical Protocols↗
PubMed1999

Acute sporadic non-A, non-B hepatitis in Northeastern Brazil: etiology and natural history.

In a 4-year follow-up study, patients with acute sporadic non-A, non-B (NANB) hepatitis were evaluated to determine the etiology and natural history of the disease. Acute hepatitis C virus (HCV) was detected in 13 of 43 (30%) of patients, anti-hepatitis E virus (HEV) IgG in 5 (12%), and 25 (58%) were considered non-A-E. The HCV RNA was detected in all HCV patients but none of the non-A-E cases. The initial clinical and biochemical presentation of the HCV and non-A-E cases was quite similar, although 2 of the non-A-E patients had severe disease. The 5 patients who were found to be anti-HEV IgG-reactive recovered within 6 months of follow-up. Of the 13 HCV cases, alanine transaminase (ALT) levels returned to normal in 7 (53. 8%), while 6 (46.2%) continued to show abnormal ALT after 6 months of follow-up. However, 9 (69.2%) of them remained HCV-RNA-positive, denoting virological/biochemical dissociation. Long-term follow-up showed a reappearance of HCV RNA in 2 of the 4 patients who were in virological remission performing 84% of chronicity rate. Acute non-A-E hepatitis patients were less likely to evolve toward chronicity, as compared with acute HCV cases (16% vs. 84%; P =.0001). Only 4 (16%) of the non-A-E patients were hepatitis G virus (HGV)-RNA-positive. Concerning risk factors for acquiring parenterally transmitted viruses, tattooing was the only one that could be associated with HCV transmission (P =.002). No risk factors could be identified for putative non-A-E virus transmission. Liver biopsies performed for chronic HCV patients showed a variable degree of inflammation, while the non-A-E patients presented less severe histological disease.

Acute Disease↗
PubMed1999

[Practice guidelines of the Spanish Society of Cardiology. Cardiac and heart-lung transplants].

Cardiac transplantation is the only therapy that is able to substantially modify the natural evolution of patients with severe heart failure, along with angiotensin converting enzyme inhibitors. Nevertheless, because of the limited number of donors, its impact is scarce compared to the magnitude of the problem. Up to the end of 1998, 48,541 orthotopic cardiac transplantations and about 2,510 heart and both lung transplantations have been registered throughout the world. In Spain 2,780 procedures have been performed in the last 15 years. The survival expectations for a transplanted patient is 75% after the first year and 60% the following 5 years. The average duration of the graft is 8 years and 6 months. Cardiac transplantation is indicated for young and middle-age patients with irreversible cardiac process in bad clinical condition, with no other possibility of medical or surgical management and with a limited life expectancy. The major debate when choosing this therapy appears with the critical patients, patients older than 65 years, and some patients with systemic diseases. The great demand of transplantation obliges the teams to enlarge the criteria for donors' acceptance. At the same time, the increase of the knowledge about the transmission of some infections, mainly viral, forces to review those criteria day-to-day. The use of different immunosuppressive strategies pursues the control of rejection. The most commonly used is the so-called triple therapy (cyclosporine-azathioprine and steroids). The use of antilymphocytic antibodies such as cytolytic induction treatment is not unanimously accepted. Some of the new immunosuppressive agents such as myphenolate-mofetil and tacrolimus seem to offer advantages mainly due to their greater potency. Since transplantation is a limited procedure, of which its practise has an effect on the whole health system of a country, a perfect planning and adequacy of the Centers is compulsory, as well as the setting-up of clear rules for the use of donors and priority of transplantation. Finally, the patient must be informed clearly and comprehensively at length of the risks, limitations and expectations of these complex procedures.

Biopsy↗
PubMed1999

Understanding variability in physician ratings of the appropriateness of coronary angiography after acute myocardial infarction.

We examined variability in ratings of the appropriateness of coronary angiography for 890 clinical scenarios (indications) after an acute myocardial infarction (AMI) from a nine-member multispecialty panel as a function of panel characteristics and the attributes of the clinical indications. We documented a substantial degree of reliability in the ratings. However, key differences among the experts in terms of both their overall propensity to score high and their beliefs regarding the impact of clinical factors on appropriateness were identified. Age, cardiac complications, post-AMI angina, and noninvasive test results were the clinical factors most strongly related to appropriateness ratings for coronary angiography. Further research on the effectiveness of coronary angiography in older patients and in patients with shock, pulmonary edema, and silent ischemia is needed to improve our knowledge about the appropriateness of this procedure in these patients.

Aged↗