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Biomedical subjects

M A Costa

Publications and source records attributed to M A Costa.

At least 19 recordsLinked to original sources
PubMed2005

How should success be defined when attempting medical resolution of first-trimester missed abortion?

OBJECTIVES: There is currently no consensus on how success should be defined after medical management of first-trimester missed abortion. The aim of this study was to determine the transvaginal ultrasound criterion associated with highest success rate and, at the same time, lowest long-term complications. DESIGN: Prospective observational study of consecutively enrolled patients. SETTING: A tertiary care university hospital in northern Portugal. PARTICIPANTS: Forty-four women submitted to medical management of first-trimester missed abortion using a regimen of vaginal misoprostol, with histologically confirmed conception products passed vaginally. A transvaginal ultrasound scan was performed by an experienced sonographer in the morning after treatment, to characterise uterine content. Patients were provided with a chart for daily registration of axillary temperature, vaginal bleeding and lower abdominal pain. Transvaginal ultrasound was repeated 2-3 weeks later, and again after the following menses. MAIN OUTCOME MEASURES: Success rates of medical management when post-treatment transvaginal ultrasound criteria for subsequent expectant management were: absence of intra-uterine sac, largest anteroposterior diameter of hyperechogenic content, and maximum area of hyperechogenic intra-uterine content in a sagittal view. Self-reported duration of vaginal bleeding and abdominal pain after medical treatment. RESULTS: Success rate was 86% (38/44) when absence of gestational sac on the 12 h transvaginal ultrasound was used as the main criterion for subsequent expectant management and there was no need for further intervention. The success rate using the ultrasound criterion anteroposterior diameter < or = 15 mm was 51% (22/43), and with maximum sagittal plane area under 7.5 cm(2), 72% (31/43). Mean duration of vaginal haemorrhage was 9 days (minimum 2 days, maximum 14 days) and of lower abdominal pain 6 days (minimum 0 days, maximum 14 days). No patient recorded an axillary temperature exceeding 37 degrees C. No apparent relationship between the size of ultrasound-estimated intra-uterine content and duration of symptoms was observed. CONCLUSIONS: Absence of gestational sac on transvaginal ultrasound should be the criterion used to document success after medical management of first-trimester missed abortion, as it is associated with the highest short and long-term success rates, as well as mild and self-limited symptoms in the days following treatment.

Abdominal Pain↗
PubMed2004

Sedation, sucralfate, and antibiotic use are potential means for protection against early-onset ventilator-associated pneumonia.

To examine risk factors for early-onset ventilator-associated pneumonia (EOP) in patients requiring mechanical ventilation (MV), we performed a prospective cohort study that included 747 patients. Pneumonia was defined as a positive result for a protected quantitative distal sample. EOP was defined as pneumonia that occurred from day 3 to day 7 of MV. Eighty patients (10.7%) experienced EOP. Independent predictors of EOP were male sex (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.18-3.63), actual Glasgow Coma Scale value of 6-13 (OR, 1.95; 95% CI, 1.2-3.18), high Logistic Organ Dysfunction score at day 2 (OR, 1.12 per point; 95% CI, 1.02-1.23), unplanned extubation (OR, 3.19; 95% CI, 1.28-7.92), and sucralfate use (OR, 1.81; 95% CI, 1.01-3.26). Protection occurred with use of aminoglycosides (OR, 0.36; 95% CI, 0.17-0.76), beta -lactams and/or beta -lactamase inhibitors (OR, 0.47; 95% CI, 0.28-0.83), or third-generation cephalosporins (OR, 0.33; 95% CI, 0.16-0.74). Sucralfate use and unplanned extubation are independent risk factors for EOP. Use of aminoglycosides, beta-lactams/ beta-lactamase inhibitors, or third-generation cephalosporins protects against EOP.

Aged↗
PubMed2004

Saphenous vein graft disease.

Saphenous vein graft (SVG) disease has been an obstinate problem facing the cardiologist since the early days of coronary artery bypass grafting (CABG) surgery. SVG disease follows temporally distinct phases of thrombosis, intimal hyperplasia and progressive atherosclerosis leading to recurrent ischemia which can be treated with repeat operation or percutaneous revascularization. However, repeat operation is associated with high mortality and morbidity. Also, percutaneous treatment of SVG disease is complicated by a high rate of procedural and long term complications due to the interrelated phenomena of distal embolization, slow flow or no reflow, periprocedure myocardial infarction, and subsequent restenosis. Long-term patency is poor in this patient population regardless of the treatment modality. Many pharmaceutical and device based approaches have been tested to avert these complications, but few, such as the use of distal protection devices, have shown benefit. The novel drug-eluting stents show promise in reducing the occurrence of restenosis and solving one of the problems associated with the percutaneous treatment of SVG disease. The pathogenesis and therapeutic options for SVG disease is reviewed in this article.

Angioplasty, Balloon, Coronary↗
PubMed2003

Use of rapamycin-impregnated stents in coronary arteries.

FIM STUDY: We investigated the 2-year safety and efficacy of sirolimus-eluting stents. Thirty patients had a single 18-mm sirolimus-eluting coronary stent implanted. Twenty-eight patients underwent angiographic and intravascular ultrasound follow-up at 2 years. No death occurred during the study period. No patient developed in-stent restenosis. One patient had a 52% in-lesion stenosis that required repeated revascularization and another patient underwent target vessel revascularization. Neointimal hyperplasia volume was minimal at 2 years in both groups. This study demonstrates the 2-year safety and efficacy of sirolimus-eluting stenting. The slow release formulation showed slight superiority over the fast-release formulation in preventing late lumen loss, which was minimal in both groups. RAVEL TRIAL: This-study was a randomized, double-blind study that included 238 patients at 19 medical centers (15 in Europe, 3 in Brazil, and 1 in Mexico). Patients were eligible for the study if they were between 18 and 85 years of age, and had been given a diagnosis of stable or unstable angina or silent ischemia. Additional eligibility criteria were presence of a single primary target lesion in a native coronary artery that was 2.5 to 3.5 mm in diameter and that could be covered by an 18-mm stent stenosis of 51% to 99% of the luminal diameter and a flow rate of grade 1 or higher according to the Thrombolysis in Myocardial Infarction. RESULTS: One hundred twenty patients were randomly assigned to receive the sirolimus-eluting stent, and 118 were assigned to receive the standard stent. At 6 months, the degree of neointimal proliferation, manifested as the mean (+/-SD) late luminal loss, was significantly lower in the sirolimus-stent group (-0.01 +/- 0.33 mm) than in the standard-stent group (0.80 +/- 0.53 mm, P <.001). None of the patients in the sirolimus-stent group, as compared with 26.6% of those in the standard-stent group, had restenosis of >/=50% of the luminal diameter (P <.001). There were no episodes of stent thrombosis. During a follow-up period of up to 1 year, the overall rate of major cardiac events was 5.8% in the sirolimus-stent group and 28.8% in the standard-stent group (P <.001). The difference was due entirely to the higher rate of revascularization of the target vessel in the standard-stent group. CONCLUSION: Patients with angina who received sirolimus-eluting stents for the treatment of single, primary lesions in native coronary arteries had no angiographic evidence of late luminal loss or in-stent restenosis at 6 months, no episodes of thrombosis, and a very low rate of cardiac events at 1 year.

Adolescent↗
PubMed2002

Coronary flow velocity reserve after percutaneous interventions is predictive of periprocedural outcome.

BACKGROUND: Because heterogeneous results have been reported, we assessed coronary flow velocity changes in individuals who underwent percutaneous transluminal coronary angioplasty (PTCA) and examined their impact on clinical outcome. METHODS AND RESULTS: As part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II study, 379 patients underwent Doppler flow-guided angioplasty. All patients were evaluated according to their coronary flow velocity reserve (CFVR) results (> or =2.5 or < 2.5) at the end of the procedure. A CFVR < 2.5 after angioplasty was associated with an elevated baseline blood flow velocity in both the target artery and reference artery. CFVR before PTCA and CFVR in the reference artery were independent predictors of an optimal CFVR after balloon angioplasty (CFVR before PTCA: odds ratio [OR], 2.26; 95% confidence interval [CI], 1.57 to 3.24; CFVR in reference artery: OR, 1.90; 95% CI, 1.21 to 2.98; both P<0.001) and stent implantation (before PTCA: OR, 2.54; 95% CI, 1.47 to 4.36; reference artery: OR, 1.97; 95% CI, 1.07 to 3.87; both P<0.05). A low CFVR at the end of the procedure was an independent predictor of major adverse cardiac events (MACE) at 30 days (OR, 4.71; 95% CI, 1.14 to 25.92; P=0.034) and at 1 year (OR, 2.06; 95% CI, 1.16 to 3.66; P=0.014). After excluding MACE at 30 days, no difference in MACE at 1 year was observed between the patients with and without a CFVR < 2.5 at the end of the procedure. CONCLUSIONS: A low postprocedural CFVR was associated with a worse periprocedural outcome (which was related to microcirculatory disturbances), but there was no significant difference at late follow-up.

Angioplasty, Balloon, Coronary↗
PubMed2002

Si(3)N(4)-bioglass composites stimulate the proliferation of MG63 osteoblast-like cells and support the osteogenic differentiation of human bone marrow cells.

The in vitro osteocompatibility of a novel Si(3)N(4)-bioglass composite (70-30% weight proportion) with improved mechanical properties (fracture toughness = 4.4 M Pa m(1/2); bending strength = 383 +/- 47 MPa) is reported. Immersion of the composite samples in culture medium (30 min to 7 days) resulted in rapid protein adsorption to the surface and, also, dissolution of the intergranular phase of bioglass (time-dependent process) with the formation of different size cavities. "As-received" and pre-treated material samples presented a similar behaviour concerning the proliferation of MG63 osteoblast-like cells, evaluated during a 5-day culture period. Seeded materials showed a higher cell growth rate as compared to cultures performed on the standard plastic culture plates. To assess the osteogenic potential of the composite, "as-received" material samples were seeded with human bone marrow cells and cultured for 35 days in experimental conditions that favour the development of the osteoblastic phenotype. The cell adhesion process was similar to that observed in control cultures. Cells successfully adapted to the irregularities of the surface and were able to grow towards inside the cavities; in addition, osteogenic differentiation occurred with the formation of abundant cell-mediated mineralised deposits. Results suggest that this Si(3)N(4)-bioglass composite seems to be a promising candidate for high-stress medical applications.

Adsorption↗
PubMed2002

[False hyperchloremia in a bromide intoxication].

A false hyperchloremia in a patient with a history of depression suspected bromide intoxication. The diagnosis was confirmed by an increased bromide concentration > 20 mmoL.L-1. Rehydration was effective and allowed to decrease bromide concentration. In conclusion, hyperchloremia associated with a negative anion gap is a clue to the diagnosis.

Bromides↗
PubMed2002

Initial observation regarding changes in vessel dimensions after balloon angioplasty and stenting followed by catheter-based beta-radiation. Is stenting necessary in the setting of catheter-based radiotherapy?

AIMS: We sought to compare the effect of intracoronary beta-radiation on the vessel dimensions in de novo lesions using three-dimensional intravascular ultrasound quantification after balloon angioplasty and stenting. METHODS AND RESULTS: Forty patients (44 vessels; 28 balloon angioplasty and 16 stenting) treated with catheter-based beta-radiation and 18 non-irradiated control patients (18 vessels; 10 balloon angioplasty and 8 stenting) were investigated by means of three-dimensional volumetric intravascular ultrasound analysis post-procedure and at 6-8 months follow-up. Total vessel (EEM) volume enlarged after both balloon angioplasty and stenting (+37 mm(3) vs +42 mm(3), P=ns), but vessel wall volume (plaque plus media) also increased similarly (+33 mm(3) vs +49 mm(3), P=ns) in the irradiated patients. Lumen volume remained unchanged in both groups (+3 mm(3) vs -7 mm(3), P=ns). In the stent-covered segments, neointima at follow-up was significantly smaller in the irradiated group than the control group (8 mm(3) vs 27 mm(3), P=0.001, respectively), but the total amount of tissue growth was similar in both groups (33 mm(3) vs 29 mm(3), P=ns). CONCLUSIONS: Intracoronary beta-radiation induces vessel enlargement after balloon angioplasty and/or stenting, accommodating tissue growth. Additional stenting may not play an important role in the prevention of constrictive remodelling in the setting of catheter-based intracoronary beta-radiotherapy.

Aged↗
PubMed2002

Value of coronary stenotic flow velocity acceleration in prediction of angiographic restenosis following balloon angioplasty.

INTRODUCTION: Quantitative angiographic assessment after balloon angioplasty is a poor predictor of immediate and long-term outcome. However, the measurement of blood flow velocity during angioplasty has been proved clinically useful. AIMS: To analyse the value of the maximal stenotic flow velocity and the presence of stenotic flow velocity acceleration (aSV) for the long-term outcome after balloon angioplasty. METHODS AND RESULTS: Patients undergoing single lesion angioplasty within the DEBATE trial were included. aSV was defined as acceleration in the stenotic coronary flow velocity >50% baseline velocity assessed at a reference site of the target vessel. After balloon angioplasty diameter stenosis, minimal lumen diameter (MLD) and coronary flow velocity reserve were similar between the aSV (n=54) and non-aSV group (n=125). At follow-up, the aSV group had a higher restenosis rate (52% vs 30%, P=0.006) The presence of aSV was the strongest independent predictor of restenosis (OR 3.08, 95% CI 1.35 to 7.05, P=0.008). The best predictive cut-off value of SV was 101cm.s(-1) (sensitivity of 46%, specificity of 81%, positive predictive value of 85% and a negative predictive value of 58%). CONCLUSION: Following angioplasty, SV appears to be exquisitely sensitive to the changes experienced at the treated area without depending on the status of the microcirculation.

Angioplasty, Balloon↗
PubMed2002

Paradoxical responses in a cohort of HIV-1-infected patients with mycobacterial disease.

SETTING: Paradoxical worsening or relapse of opportunistic infections has been described after initiation of highly active anti-retroviral therapy (HAART) in human immunodeficiency virus (HIV) infected patients. DESIGN: Retrospective study of a group of 33 HIV-infected patients with mycobacterial disease analysing the incidence and characteristics of patients with and without paradoxical response after starting HAART and/or mycobacterial treatment. RESULTS: Nine patients in the group had paradoxical response. No significant difference of baseline characteristics was observed in these patients. The decrease in viral load was significantly greater among patients with paradoxical response than in patients without. CONCLUSION: No clinical difference was found in the evolution of HIV-infected patients with mycobacterial disease after the resolution of the episode of paradoxical response.

AIDS-Related Opportunistic Infections↗
PubMed2001

Incidence, predictors, and significance of abnormal cardiac enzyme rise in patients treated with bypass surgery in the arterial revascularization therapies study (ARTS).

BACKGROUND: Although it has been suggested that elevation of CK-MB after percutaneous coronary intervention is associated with adverse clinical outcomes, limited data are available in the setting of coronary bypass grafting. The aim of the present study was to determine the incidence, predictors, and prognostic significance of CK-MB elevation following multivessel coronary bypass grafting (CABG). METHODS AND RESULTS: The population comprises 496 patients with multivessel coronary disease assigned to CABG in the Arterial Revascularization Therapies Study (ARTS). CK-MB was prospectively measured at 6, 12, and 18 hours after the procedure. Thirty-day and 1-year clinical follow-up were performed. Abnormal CK-MB elevation occurred in 61.9% of the patients. Patients with increased cardiac-enzyme levels after CABG were at increased risk of both death and repeat myocardial infarction within the first 30 days (P=0.001). CK-MB elevation was also independently related to late adverse outcome (P=0.009, OR=0.64). CONCLUSIONS: Increased concentrations of CK-MB, which are often dismissed as inconsequential in the setting of multivessel CABG, appear to occur very frequently and are associated with a significant increase in both repeat myocardial infarction and death beyond the immediate perioperative period.

Biomarkers↗
PubMed2001

Sustained suppression of neointimal proliferation by sirolimus-eluting stents: one-year angiographic and intravascular ultrasound follow-up.

BACKGROUND: We have previously reported a virtual absence of neointimal hyperplasia 4 months after implantation of sirolimus-eluting stents. The aim of the present investigation was to determine whether these results are sustained over a period of 1 year. METHODS AND RESULTS: Forty-five patients with de novo coronary disease were successfully treated with the implantation of a single sirolimus-eluting Bx VELOCITY stent in São Paulo, Brazil (n=30, 15 fast release [group I, GI] and 15 slow release [GII]) and Rotterdam, The Netherlands (15 slow release, GIII). Angiographic and volumetric intravascular ultrasound (IVUS) follow-up was obtained at 4 and 12 months (GI and GII) and 6 months (GIII). In-stent minimal lumen diameter and percent diameter stenosis remained essentially unchanged in all groups (at 12 months, GI and GII; at 6 months, GIII). Follow-up in-lesion minimal lumen diameter was 2.28 mm (GIII), 2.32 mm (GI), and 2.48 mm (GII). No patient approached the >/=50% diameter stenosis at 1 year by angiography or IVUS assessment, and no edge restenosis was observed. Neointimal hyperplasia, as detected by IVUS, was virtually absent at 6 months (2+/-5% obstruction volume, GIII) and at 12 months (GI=2+/-5% and GII=2+/-3%). CONCLUSIONS: This study demonstrates a sustained suppression of neointimal proliferation by sirolimus-eluting Bx VELOCITY stents 1 year after implantation.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Clinical and economic impact of diabetes mellitus on percutaneous and surgical treatment of multivessel coronary disease patients: insights from the Arterial Revascularization Therapy Study (ARTS) trial.

BACKGROUND: Our aims were to compare coronary artery bypass grafting (CABG) and stenting for the treatment of diabetic patients with multivessel coronary disease enrolled in the Arterial Revascularization Therapy Study (ARTS) trial and to determine the costs of these 2 treatment strategies. METHODS AND RESULTS: Patients (n=1205) were randomly assigned to stent implantation (n=600; diabetic, 112) or CABG (n=605; diabetic, 96). Costs per patient were calculated as the product of each patient's use of resources and the corresponding unit costs. Baseline characteristics were similar between the groups. At 1 year, diabetic patients treated with stenting had the lowest event-free survival rate (63.4%) because of a higher incidence of repeat revascularization compared with both diabetic patients treated with CABG (84.4%, P<0.001) and nondiabetic patients treated with stents (76.2%, P=0.04). Conversely, diabetic and nondiabetic patients experienced similar 1-year event-free survival rates when treated with CABG (84.4% and 88.4%). The total 1-year costs for stenting and CABG in diabetic patients were $12 855 and $16 585 (P<0.001) and in the nondiabetic groups, $10 164 for stenting and $13 082 for surgery. CONCLUSIONS: Multivessel diabetic patients treated with stenting had a worse 1-year outcome than patients assigned to CABG or nondiabetics treated with stenting. The strategy of stenting was less costly than CABG, however, regardless of diabetic status.

Cerebrovascular Disorders↗
PubMed2001

Evaluation of the models available for the prediction of pressure drop in venturi scrubbers.

The major running cost derived from the operation of venturi scrubbers is pressure drop. In the present study, the predictions of different models are compared to experimental data from venturi scrubbers of different sizes (throat diameter from 1.9 to 16cm), geometries, operating variables and liquid injection arrangements. As a result, it is concluded that most of the models must be used with caution. Much attention must be paid to the validity of the assumptions employed in the mathematical models. The equations proposed by Calvert [Scrubbing, Air Pollution, 3rd Edition, Vol. IV, Academic Press, New York, 1982], Yung et al. [JAPCA 27 (1977) 348] or Hesketh [Atomization and cloud behaviour in wet scrubbers, in: Proceedings of the US-USSR Symposium Control Fine Particulate Emissions 1974, San Francisco, 15-18 January 1974] produce good results only in very specific situations. The model proposed by Boll [Ind. Eng. Chem. Fundam. 12 (1973) 40] is simple, easy to compute and agrees reasonably well with the experimental data. Unfortunately, it cannot predict the effect of different liquid injection arrangements. The model by Azzopardi and coworkers [Filtr. Sep. 21 (1984) 196; Trans. IchemE. 69B (1991) 237; Chem Eng. J. 67 (1997) 9] was the only one to give good predictions for all the range of variables studied. On the other hand, this model is not simple and requires from the engineer an additional effort in terms of computation. In order to apply this model to the rectangular geometry, the concept of hydraulic equivalent diameter was used.

Aerosols↗
PubMed2001

Secoisolariciresinol dehydrogenase purification, cloning, and functional expression. Implications for human health protection.

Matairesinol is a central precursor in planta in the biosynthesis of numerous lignans, including that of the important antiviral and anticancer agent, podophyllotoxin. In this study, the approximately 32-kDa NAD-dependent secoisolariciresinol dehydrogenase, which catalyzes the enantiospecific conversion of (-)-secoisolariciresinol into (-)-matairesinol in Forsythia intermedia, was purified >6,000-fold to apparent homogeneity. The 831-base pair cDNA clone encoding this 277-amino acid protein was next obtained from a library constructed from F. intermedia stem tissue, whose fully functional recombinant protein, produced by expression of this cDNA in Escherichia coli, catalyzed the same enantiospecific conversion via the corresponding lactol intermediate. A homologous secoisolariciresinol dehydrogenase gene was also isolated from a Podophyllum peltatum rhizome cDNA library, whose 834-base pair cDNA clone encoded a 278-amino acid protein with a calculated molecular mass of approximately 32 kDa. Expression of this protein in E. coli produced a fully functional recombinant protein that also catalyzed the enantiospecific conversion of (-)-secoisolariciresinol into (-)-matairesinol via the intermediary lactol. Various kinetic parameters were defined and established conversion of the intermediary lactol as being rate-limiting. With this overall enzymatic conversion now unambiguously defined, the entire biochemical pathway to the lignans, secoisolariciresinol and matairesinol, has been elucidated. Last, both secoisolariciresinol and matairesinol are metabolized in the gut of mammals, following digestion of high fiber dietary grains, seeds, and berries, into the so-called "mammalian" lignans, enterodiol and enterolactone, respectively; these in turn confer significant protection against the onset of breast and prostate cancers.

Alcohol Oxidoreductases↗
PubMed2001

Lack of neointimal proliferation after implantation of sirolimus-coated stents in human coronary arteries: a quantitative coronary angiography and three-dimensional intravascular ultrasound study.

BACKGROUND: Restenosis remains an important limitation of interventional cardiology. Therefore, we aimed to determine the safety and efficacy of sirolimus (a cell-cycle inhibitor)-coated BX Velocity stents. METHODS AND RESULTS: Thirty patients with angina pectoris were electively treated with 2 different formulations of sirolimus-coated stents (slow release [SR], n=15, and fast release [FR], n=15). All stents were successfully delivered, and patients were discharged without clinical complications. Independent core laboratories analyzed angiographic and 3D volumetric intravascular ultrasound data (immediately after procedure and at 4-month follow-up). Eight-month clinical follow-up was obtained for all patients. There was minimal neointimal hyperplasia in both groups (11.0+/-3.0% in the SR group and 10.4+/-3.0% in the FR group, P:=NS) by ultrasound and quantitative coronary angiography (in-stent late loss, 0.09+/-0.3 mm [SR] and -0.02+/-0.3 mm [FR]; in-lesion late loss, 0.16+/-0.3 mm [SR] and -0.1+/-0.3 mm [FR]). No in-stent or edge restenosis (diameter stenosis >or=50%) was observed. No major clinical events (stent thrombosis, repeat revascularization, myocardial infarction, or death) had occurred by 8 months. CONCLUSIONS: The implantation of sirolimus-coated BX Velocity stents is feasible and safe and elicits minimal neointimal proliferation. Additional placebo-controlled trials are required to confirm these promising results.

Aged↗