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Biomedical subjects

Fernando Costa

Publications and source records attributed to Fernando Costa.

At least 19 recordsLinked to original sources
PubMed2007

Impact of diabetes on five-year outcomes of patients with multivessel coronary artery disease.

BACKGROUND: Diabetes mellitus is a major cause of coronary artery disease. Despite improvement in the management of patients with stable coronary artery disease, diabetes remains a major cause of increased morbidity and mortality. Although coronary artery bypass grafting surgery (CABG) and percutaneous coronary intervention are widely used, no conclusive evidence exists that either treatment modality is better than medical therapy alone for the treatment of stable single- or multivessel coronary disease in patients with diabetes. METHODS: We compared medical therapy, percutaneous coronary intervention, and CABG in 499 diabetic patients (38.5%) and 799 nondiabetic patients (61.5%) with single- or multivessel coronary disease. The composite primary endpoint was cardiac-related death, Q-wave myocardial infarction, or refractory angina requiring revascularization. RESULTS: We treated 1,298 patients with either CABG (n = 524), percutaneous coronary intervention (n = 378), or medical therapy (n = 396). More deaths occurred among patients with diabetes than among patients without diabetes, regardless of which option was used (p < 0.001). When treatment modalities were stratified according to the number of diseased vessels, CABG was shown to be more beneficial for patients with diabetes and multivessel disease than for patients with diabetes and single-vessel disease (p < 0.001). However, when stratified by treatment, patients with diabetes receiving medical therapy had a worse prognosis than patients with diabetes treated with CABG (p = 0.005). CONCLUSIONS: All three therapeutic regimens resulted in high rates of cardiac-related deaths among patients with diabetes compared with patients without diabetes. Moreover, we observed better outcomes among patients with diabetes and multivessel coronary artery disease undergoing CABG regarding the primary endpoint at 5-year follow-up.

Adult↗
PubMed2007

Primary prevention of cardiovascular diseases in people with diabetes mellitus: a scientific statement from the American Heart Association and the American Diabetes Association.

The American Heart Association (AHA) and the American Diabetes Association (ADA) have each published guidelines for cardiovascular disease prevention: the ADA has issued separate recommendations for each of the cardiovascular risk factors in patients with diabetes, and the AHA has shaped primary and secondary guidelines that extend to patients with diabetes. This statement will attempt to harmonize the recommendations of both organizations where possible but will recognize areas in which AHA and ADA recommendations differ.

American Heart Association↗
PubMed2006

Primary prevention of cardiovascular diseases in people with diabetes mellitus: a scientific statement from the American Heart Association and the American Diabetes Association.

The American Heart Association (AHA) and the American Diabetes Association (ADA) have each published guidelines for cardiovascular disease prevention: The ADA has issued separate recommendations for each of the cardiovascular risk factors in patients with diabetes, and the AHA has shaped primary and secondary guidelines that extend to patients with diabetes. This statement will attempt to harmonize the recommendations of both organizations where possible but will recognize areas in which AHA and ADA recommendations differ.

American Heart Association↗
PubMed2006

Beta2-adrenoceptor genotype and function affect hemodynamic profile heterogeneity in postural tachycardia syndrome.

Previous studies suggest that the beta2-adrenoceptor functions abnormally in patients with postural tachycardia syndrome (POTS) and may contribute to their altered hemodynamic profile. To test the hypothesis that the beta2-adrenoceptor response is decreased in POTS, we studied: (1) the arterial vasodilation response to the beta agonist, isoproterenol, and (2) the distribution of common polymorphisms (codons 16 and 27) of the gene coding the receptor (beta2-AR) in a large population with POTS. We measured plasma catecholamines and monitored hemodynamics and changes in forearm and leg blood flow to incremental doses of intraarterial isoproterenol in 9 patients with POTS compared with 8 healthy subjects. For polymorphism assessment we collected DNA from 57 patients with POTS and compared with 67 age-sex matched healthy subjects. Circulating catecholamines were significantly higher in POTS subjects compared with controls. Intrabrachial and intrafemoral isoproterenol infusion elicited a dose-dependent increase in blood flow. In healthy subjects, blood flow increased (mean+/-SEM) 400+/-70% in the forearm and 170+/-40% in the leg, but only 280+/-60% in forearms and 120+/-20% in legs of patients with POTS (ANOVA for both P<0.001). The genotype and allele distributions for codons 16 and 27 beta2-AR variants were not different in the 2 groups. However, the blood pressure and plasma norepinephrine levels diverged in patients according to their genotype. Patients with Gly16Gly and patients with Glu27Glu had lower plasma catecholamines and higher supine and upright blood pressure, compared with other genotypes. Therefore, both decreased beta2-adrenoceptor-related vasodilation and beta2-AR polymorphisms may contribute to the hemodynamic diversity of patients with POTS.

Adrenergic beta-Agonists↗
PubMed2005

Population structure of the Brazilian southern green stink bug, Nezara viridula.

The Southern Green Stink Bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), is a cosmopolitan and economically important pest to several crops. Studies on N. viridula migration and population structure have been neglected. We studied geographically distinct Brazilian N. viridula populations to assess their variability and to determine gene flow among them. DNA from specimens collected on soybean fields were subjected to RAPD analysis to determine genetic similarity and population structure parameters. All N. viridula populations studied were genetically distinct from the others. The maximum similarity occurred between populations from Londrina and Sertanópolis (Parana State). The Cruz Alta population was the most divergent from the others. Despite the short distance between Cambé and Londrina (ca. 29 km), and the absence of geographic barriers, both populations clustered in different groups and the estimated gene flow index (Nm) among them was 2.02, indicating relatively restricted migration. The estimated overall index, Nm was 1.41 suggesting that N. viridula is a better flier than the Neotropical Brown stink bug, Euschistus heros (Nm =0.83).

Animals↗
PubMed2005

Cardiac rehabilitation and secondary prevention of coronary heart disease: an American Heart Association scientific statement from the Council on Clinical Cardiology (Subcommittee on Exercise, Cardiac Rehabilitation, and Prevention) and the Council on Nutrition, Physical Activity, and Metabolism (Subcommittee on Physical Activity), in collaboration with the American association of Cardiovascular and Pulmonary Rehabilitation.

This article updates the 1994 American Heart Association scientific statement on cardiac rehabilitation. It provides a review of recommended components for an effective cardiac rehabilitation/secondary prevention program, alternative ways to deliver these services, recommended future research directions, and the rationale for each component of the rehabilitation/secondary prevention program, with emphasis on the exercise training component.

Coronary Disease↗
PubMed2004

The clinician as investigator: participating in clinical trials in the practice setting.

The rapid development of new drugs, therapies, and devices has created a dramatic increase in the number of trials needed to properly evaluate them. The majority of patients treated today, many of whom could be eligible for participation in these studies, are seen in community hospitals and medical practices that are not affiliated with an academic medical center. Thus, there is a demonstrable need for physicians in private practice to enlist as investigators in these trials. This article is intended to encourage those physicians by describing the need and providing the rationale for their participation. It covers basic requirements for participating in clinical trials and outlines ethical, regulatory, financial, and other logistical issues of importance for the potential investigator and provides an algorithm for selecting a study for participation. Finally, the appendices review basic elements of study design and statistical principles, which may be of interest to a potential investigator.

Choice Behavior↗
PubMed2003

Blockade of nucleoside transport is required for delivery of intraarterial adenosine into the interstitium: relevance to therapeutic preconditioning in humans.

BACKGROUND: Adenosine, a known mediator of preconditioning, has been infused into the coronary circulation to induce therapeutic preconditioning, eg, in preparation for angioplasty. However, results have been disappointing. We tested the hypothesis that endothelial nucleoside transporter acts as a barrier impeding the delivery of intravascular adenosine into the underlying myocardium and that this can be overcome with dipyridamole, a nucleoside transporter blocker. METHODS AND RESULTS: We infused saline or adenosine (0.125 and 0.5 mg/min) into the brachial artery while monitoring forearm blood flow (FBF) and interstitial adenosine levels with microdialysis probes implanted in the flexor digitorum superficialis of the forearm in 7 healthy volunteers during intravenous administration of saline or dipyridamole (loading dose, 0.142 mg/kg per min for 5 minutes followed by 0.004 mg/kg per min). Adenosine produced near maximal forearm vasodilation, increasing FBF from 4.0+/-0.7 to 10.4+/-1.9 and 13.1+/-1.6 mL/100 mL per min for the low and high doses, respectively, but did not increase muscle dialysate adenosine concentration (from 88+/-21 to 65+/-23 and 85+/-26 nmol/L). Intravenous dipyridamole enhanced resting muscle dialysate adenosine (from 77+/-25 to 147+/-50 nmol/L), adenosine-induced increase in FBF (from 4.1+/-0.8 to 12.6+/-3 and 15.1+/-3 mL/100 mL per min for the low and high dose, respectively), and the delivery of adenosine into the interstitium (to 290+/-80 and 299+/-143 nmol/L for the low and high dose, respectively, P=0.04). CONCLUSIONS: Intravascular adenosine is likely ineffective in inducing myocardial preconditioning because of poor interstitial delivery. This can be overcome by blocking the nucleoside transporter with dipyridamole.

Adenosine↗
PubMed2003

The generation and utilization of a cancer-oriented representation of the human transcriptome by using expressed sequence tags.

Whereas genome sequencing defines the genetic potential of an organism, transcript sequencing defines the utilization of this potential and links the genome with most areas of biology. To exploit the information within the human genome in the fight against cancer, we have deposited some two million expressed sequence tags (ESTs) from human tumors and their corresponding normal tissues in the public databases. The data currently define approximately 23,500 genes, of which only approximately 1,250 are still represented only by ESTs. Examination of the EST coverage of known cancer-related (CR) genes reveals that <1% do not have corresponding ESTs, indicating that the representation of genes associated with commonly studied tumors is high. The careful recording of the origin of all ESTs we have produced has enabled detailed definition of where the genes they represent are expressed in the human body. More than 100,000 ESTs are available for seven tissues, indicating a surprising variability of gene usage that has led to the discovery of a significant number of genes with restricted expression, and that may thus be therapeutically useful. The ESTs also reveal novel nonsynonymous germline variants (although the one-pass nature of the data necessitates careful validation) and many alternatively spliced transcripts. Although widely exploited by the scientific community, vindicating our totally open source policy, the EST data generated still provide extensive information that remains to be systematically explored, and that may further facilitate progress toward both the understanding and treatment of human cancers.

Chromosome Mapping↗