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Biomedical subjects

M Cerqueira

Publications and source records attributed to M Cerqueira.

At least 19 recordsLinked to original sources
PubMed2005

[Acute renal ischemia--unusual cause of lumbar pain].

Acute renal artery occlusion is rarely found in daily clinical practice. Its rarity and inespecific clinical presentation are responsible for late diagnosis or diagnostic errors, with symptoms frequently being erroneously attributed to other more common entities. There is no consensus in what concerns therapeutic options. Multiple treatment modalities are described in the available literature. Some defend anticoagulant therapy and support measures only while others recommend other more invasive alternatives reaching even open surgery. The authors present two additional case reports of acute embolic renal ischemia. A thorough literature review is also presented comprehending etiological, clinic, diagnostic and therapeutic aspects.

Acute Disease↗
PubMed2005

[Bulbourethral sling. The experience of our service].

OBJECTIVES: The authors present the clinic results obtained with the bulbourethral sling application with pubic bone anchorage (Invance) in patients with stress urinary incontinence. MATERIAL AND METHODS: From July to December 2003, 10 slings were implanted in men between the 60's and the 83 years old (average 72.6 years), whose incontinence appeared after prostatic surgery (retro pubic radical prostatectomy, perineal radical prostatectomy, radical cystoprostatectomy with Camey II neobladder, transurethral resection, transvesical prostate adenomectomy). RESULTS: After 9 months follow-up (3 to 7 months), 8 patients (80%) are continent (without need of using any pad) and 2 (20%) show minimum leakage with effort (need of 1 to 2 daily pads). All are satisfied with the surgery result. Two patients referred perineal pain, which was solved with Paracetamol. There was no case of perineal haematoma, infection, rejection or urethral erosion. CONCLUSION: The bulbourethral sling with bone anchorage is a rather invasive procedure, of easy technical execution, with high continence rates and associated to low morbidity. Although the presented results been an incentive to the technique prolongation, it would be necessary a higher tracking: and higher global experience in order that this sling affirm and transform itself in an alternative to the artificial sphincter in selected cases.

Aged↗
PubMed2004

Myocardial perfusion scintigraphy: the evidence.

This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by comparison with the numbers of revascularisations and coronary angiograms performed. Furthermore, MPS activity levels in this country fall far short of those in comparable European countries, with about half as many scans being undertaken per year. Currently, the number of MPS studies performed annually in the UK is 1,200/million population/year. We estimate the real need to be 4,000/million/year. The current average waiting time is 20 weeks and we recommend that clinically appropriate upper limits of waiting time are 6 weeks for routine studies and 1 week for urgent studies.

Cardiology↗
PubMed1993

Prehospital-initiated vs hospital-initiated thrombolytic therapy. The Myocardial Infarction Triage and Intervention Trial.

OBJECTIVE: To determine the effect of prehospital-initiated vs hospital-initiated treatment of myocardial infarction on clinical outcome. DESIGN: Randomized, controlled clinical trial. SETTING: Multicenter study involving 19 hospitals and all paramedic systems in the Seattle, Wash, metropolitan area. PATIENTS: A total of 360 patients with symptoms for 6 hours or less, no risk factors for serious bleeding, and ST-segment elevation were selected by paramedics and a remote physician for inclusion into the trial. They represented 4% of patients with chest pain who were screened and 21% of those with acute infarction. INTERVENTIONS: Patients were allocated to have aspirin and alteplase treatment initiated before or after hospital arrival. Intravenous sodium heparin was administered to both groups in the hospital. MAIN OUTCOME MEASURE: The primary endpoint was a ranked composite score (combining death, stroke, serious bleeding, and infarct size). The relation between time to treatment and outcome (composite score, infarct size, ejection fraction, and mortality) was also assessed. RESULTS: Initiating treatment before hospital arrival decreased the interval from symptom onset to treatment from 110 to 77 minutes (P < .001). Although more patients whose therapy was initiated before hospital arrival had resolution of pain by admission (23% vs 7%; P < .001), there were no significant differences in the composite score (P = .64), mortality (5.7% vs 8.1%), ejection fraction (53% vs 54%), or infarct size (6.1% vs 6.5%). A secondary analysis of time to treatment and outcome showed that treatment initiated within 70 minutes of symptom onset was associated with better outcome (composite score, P = .009; mortality, 1.2% vs 8.7%, P = .04; infarct size, 4.9% vs 11.2%, P < .001; and ejection fraction, 53% vs 49%, P = .03) than later treatment. Identification of patients eligible for thrombolysis by paramedics reduced the hospital treatment time from 60 minutes (for patients not in the study) to 20 minutes (for study patients allocated to begin treatment in the hospital). CONCLUSION: There was no improvement in outcome associated with initiating treatment before hospital arrival; however, treatment within 70 minutes of symptom onset--whether in the hospital or in the field--minimized the infarct process and its complications.

Aged↗
PubMed1991

Influence of sympathetic stimulation and parasympathetic withdrawal on Doppler echocardiographic left ventricular diastolic filling velocities in young normal subjects.

To determine the effects of parasympathetic withdrawal or sympathetic stimulation on Doppler echocardiographic measures of left ventricular diastolic filling, we studied 10 young normal subjects aged 21 to 29 years during separate infusions of atropine (0.8 mg followed by 0.4 mg every 10 minutes until heart rate greater than 110 beats/min or a total dose of 2 mg was attained) and epinephrine (10, 25 and 50 ng/kg/min for 12 minutes each). At the highest atropine dose, heart rate increased from 60 +/- 9 to 105 +/- 8 beats/min (mean +/- standard deviation), the diastolic filling period decreased by 61% (573 +/- 141 to 222 +/- 34 ms), the peak early (E) filling decreased 23% (77 +/- 12 to 61 +/- 11 cm/s), the peak atrial (A) filling increased 103% (40 +/- 6 to 81 +/- 17 cm/s), and the E/A ratio decreased by 60% (2.0 +/- 0.5 to 0.8 +/- 0.3) (all p less than 0.001). These alterations were not correlated to changes in systolic function, preload, blood pressure or plasma catecholamines, all of which were unchanged. However, atropine-induced changes in diastolic filling period were highly correlated to changes in E peak (r = 0.64, p less than 0.01), A peak (r = -0.95, p less than 0.001) and the E/A ratio (r = 0.93, p less than 0.001). The effects of atropine on the E/A ratio were normalized by dividing the E/A ratio by the diastolic filling period (E/A/diastolic filling period).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Characteristics of black patients admitted to coronary care units in metropolitan Seattle: results from the Myocardial Infarction Triage and Intervention Registry (MITI).

Since 1988, 641 black and 11,892 white patients with chest pain of presumed cardiac origin have been admitted to coronary care units in 19 hospitals in metropolitan Seattle. Black men and women were younger (58 vs 66, p less than 0.0001), more often admitted to central city hospitals (p less than 0.0001), and developed evidence of acute myocardial infarction (AMI) less often (19 vs 23%, p = 0.01). In the subset of 2,870 AMI patients, blacks (n = 121) were younger (59 vs 67, p less than 0.0001) and had less prior coronary artery bypass graft surgery (2 vs 10%, p = 0.005) and more prior hypertension (67 vs 46%, p less than 0.0001). During hospitalization, whites (n = 2,749) had higher rates of coronary angioplasty (18 vs 10%, p = 0.03) and coronary artery bypass graft surgery (10 vs 4%, p = 0.04), although thrombolytic therapy and cardiac catheterization were used equally in the 2 groups. Hospital mortality was 7.4% for black and 13.1% for white patients (p = 0.07). However, after adjustment for key demographic and clinical variables by logistic regression, this difference was not as apparent (p = 0.38). Questions about the premature onset of coronary artery disease, excess systemic hypertension, and the differential use of interventions in black persons have been raised by other investigators. Despite differences in age, referral patterns and the use of coronary angioplasty and bypass surgery, black and white patients with AMI in metropolitan Seattle had similar outcomes.

Black or African American↗
PubMed1991

The relation between radionuclide angiography and Doppler echocardiography during contractile changes with infusions of epinephrine.

To define the quantitative relations between radionuclide and Doppler measures of systole during sympathetic activation with epinephrine, 10 young normal men were studied with simultaneous radionuclide angiography and M-mode and Doppler echocardiography during graded infusions of epinephrine (10, 25 and 50 ng/kg/min for 12 minutes each). During a nine-fold increase in circulating levels of epinephrine in arterialized plasma (94 +/- 59 to 879 +/- 310 pg/ml, P less than 0.001), the heart rate increased from 58 +/- 8 to 73 +/- 7 beats/min (P less than 0.01), whereas the mean arterial pressure fell from 82 +/- 3 to 75 +/- 6 mmHg (NS) and end-systolic wall stress decreased from 97 +/- 6 to 67 +/- 10 dynes/sec (P less than 0.01). The ejection fraction as estimated using radionuclide techniques increased from 68 +/- 6 to 83 +/- 6%, the peak ejection rate measured in this way increased from -3.36 +/- 0.3 to -5.10 +/- 0.5 end-diastolic volumes/sec, the ejection fraction as estimated with M-mode echocardiography increased from 66 +/- 5 to 83 +/- 5%, the echocardiographic ventricular dimension shortening increased from -1.78 +/- 0.2 to -2.7 +/- 0.4 sec-1, the peak aortic outflow velocity as measured with Doppler techniques increased from 98 +/- 13 to 147 +/- 25 cm/sec, and the aortic outflow acceleration velocity increased from 11 +/- 3 to 27 +/- 7 m/sec2 (all P less than 0.001). There was a significant correlation between the changes in radionuclide and M-mode estimations of ejection fractions (r = 0.82), between the radionuclide peak ejection rate and M-mode peak dimension shortening (r = 0.80) and between the radionuclide peak ejection rate and the Doppler peak aortic outflow velocity (r = 0.90) (all P less than 0.01). We conclude that corresponding radionuclide and Doppler echocardiographic measurements of systolic function are altered similarly during increased sympathetic activation with epinephrine.

Adult↗
PubMed1989

Platelet destruction in autoimmune thrombocytopenic purpura: kinetics and clearance of indium-111-labeled autologous platelets.

Using autologous 111In-labeled platelets, platelet kinetics and the sites of platelet destruction were assessed in 16 normal subjects (13 with and three without spleens), in 17 studies of patients with primary autoimmune thrombocytopenic purpura (AITP), in six studies of patients with secondary AITP, in ten studies of patients with AITP following splenectomy, and in five thrombocytopenic patients with myelodysplastic syndromes. In normal subjects, the spleen accounted for 24 +/- 4% of platelet destruction and the liver for 15 +/- 2%. Untreated patients with primary AITP had increased splenic destruction (40 +/- 14%, p less than 0.001) but not hepatic destruction (13 +/- 5%). Compared with untreated patients, prednisone treated patients did not have significantly different spleen and liver platelet sequestration. Patients with secondary AITP had similar platelet counts, platelet survivals, and increases in splenic destruction of platelets as did patients with primary AITP. In contrast, patients with myelodysplastic syndromes had a normal pattern of platelet destruction. In AITP patients following splenectomy, the five nonresponders all had a marked increase (greater than 45%) in liver destruction compared to five responders (all less than 40%). Among all patients with primary or secondary AITP, there was an inverse relationship between the percent of platelets destroyed in the liver plus spleen and both the platelet count (r = 0.75, p less than 0.001) and the platelet survival (r = 0.86, p less than 0.001). In a stepwise multiple linear regression analysis, total liver plus spleen platelet destruction, the platelet survival and the platelet turnover were all significant independent predictors of the platelet count. Thus platelet destruction is shifted to the spleen in primary and secondary AITP. Failure of splenectomy is associated with a marked elevation in liver destruction. The magnitude of spleen and liver destruction appears to be of considerable importance in the severity of the disease, as reflected in the platelet survival and platelet count.

Autoimmune Diseases↗
PubMed1989

Enhanced binding of the hypoxic cell marker [3H]fluoromisonidazole in ischemic myocardium.

The 2-nitroimidazole fluoromisonidazole is metabolically trapped in viable hypoxic cells in inverse proportion to PO2. This attribute suggests that [18F]fluoromisonidazole may be useful for imaging hypoxic tissue using positron emission tomography. To examine this potential, we studied the pharmacokinetics and biodistribution of [3H]fluoromisonidazole in six open chest dogs. In two normal dogs, plasma and urine samples were collected over a 4-hr period following i.v. injection of the drug. In four animals, regional myocardial ischemia was produced 2 hr prior to drug injection by occlusion of the circumflex coronary artery and maintained during the 4-hr sampling period. In all animals, postmortem samples of myocardium and other organs were obtained and tissue, plasma, and urine tritium activity were determined by liquid scintillation counting. In areas of reduced flow, [3H]fluoromisonidazole accumulated in myocardium in inverse proportion to myocardial blood flow measured by microspheres, indicating enhanced binding in hypoxic tissues. Maximum tissue concentrations in ischemic myocardium were two- to three-fold greater than in normal myocardium and plasma. Plasma clearance data indicate the drug is rapidly distributed into the total-body water, clears from the body with a half-life of 275 +/- 50 min, and undergoes minimal metabolism by 4 hr. We conclude [18F]fluoromisonidazole may be a suitable agent for radionuclide imaging of hypoxic myocardium.

Animals↗
PubMed1988

Left ventricular function in ischemic mitral regurgitation--a precatheterization assessment.

The clinical characteristics of 150 patients with unstable ischemic heart disease were evaluated for the ability to diagnose mitral regurgitation (MR). A careful assessment of physical findings, ECG- and radionuclide-determined global and regional left ventricular function was performed in all patients to characterize the population with ischemic MR. Twenty-nine patients were found to have MR and in 65% the degree of MR was 2+ or more. All of the patients with significant MR had a systolic murmur on physical examination, and although this finding was 90% sensitive for MR it had a poor predictive value (42%). Even a characteristic apical holosystolic murmur, although specific for MR (90%), had a low sensitivity and predictive value. Two regional wall motion abnormalities (inferoposterior akinesis and apical dyskinesis with an ejection fraction less than or equal to 35%) identified 26 of 29 patients with MR and all with 2+ or more MR, as well as the 10 patients who required mitral valve replacement in addition to coronary artery bypass grafting. This finding was complementary to the results of physical examination and when used together improved the diagnostic accuracy of identifying MR. The radionuclide regurgitant index was evaluated for its predictive value in assessing MR in this group of patients but was found to be a poor discriminator in patients with abnormal ejection fractions and regional wall motion abnormalities. The precatheterization assessment of left ventricular function with radionuclide angiography can provide important insight into the presence of ischemic MR.

Adult↗
PubMed1988

Ventricular function and infarct size: the Western Washington Intravenous Streptokinase in Myocardial Infarction Trial.

The Western Washington Intravenous Streptokinase in Acute Myocardial Infarction Trial randomized 368 patients with symptoms and signs of acute myocardial infarction of less than 6 h duration to either conventional care or 1.5 million units of intravenous streptokinase. The mean time to randomization was 209 min and 52% of patients were randomized within 3 h of symptom onset. Quantitative, tomographic thallium-201 infarct size and radionuclide ejection fraction were measured at 8.2 +/- 7.5 weeks in 207 survivors who lived within a 100 mile radius of a centralized laboratory. Overall, infarct size as a percent of the left ventricle was 19 +/- 13% for control subjects and 15 +/- 13% for treatment patients (p = 0.03). For anterior infarction in patients entered within 3 h of symptom onset, infarct size was 28 +/- 13% in the control group versus 19 +/- 15% for the treatment group (p = 0.09). Left ventricular ejection fraction was 47 +/- 15% in the control versus 51 +/- 15% in the treatment group (p = 0.08). For anterior infarction of less than 3 h duration, the ejection fraction was 38 +/- 16% in the control versus 48 +/- 20% in the treatment group (p = 0.13). By statistical analysis incorporating the nonsurvivors, p values for all of these variables were less than or equal to 0.08. There was no benefit for patients with inferior infarction or for anterior infarction of greater than 3 h duration. It is concluded that intravenous streptokinase, when given within 3 h of symptom onset to patients with anterior infarction, reduces infarct size and improves ventricular function.

Clinical Trials as Topic↗
PubMed1988

Relation of global and regional left ventricular function to tomographic thallium-201 myocardial perfusion in patients with prior myocardial infarction.

To determine the relation between regional myocardial perfusion and regional wall motion in humans, tomographic thallium-201 imaging and two-dimensional echocardiography at rest were performed on the same day in 83 patients 4 to 12 weeks after myocardial infarction. Myocardial perfusion and wall motion were assessed independently in five left ventricular regions (total 415 regions). Regional myocardial perfusion was quantitated as a percent of the region infarcted (range 0 to 100%) using a previously validated method. Wall motion was graded on a four point scale as 1 = normal (n = 266 regions), 2 = hypokinesia (n = 64), 3 = akinesia (n = 70), 4 = dyskinesia (n = 13) or not evaluable (n = 2). Regional wall motion correlated directly with the severity of the perfusion deficit (r = 0.68, p less than 0.0001). Among normally contracting regions, the mean perfusion defect score was only 2 +/- 4. Increasingly severe wall motion abnormalities were associated with larger perfusion defect scores (hypokinesia = 6 +/- 5, akinesia = 11 +/- 7 and dyskinesia = 18 +/- 5, all p less than 0.01 versus normal. Among regions with normal wall motion, only 3% had a perfusion defect score greater than or equal to 10. Conversely, among 68 regions with a large (greater than or equal to 10) perfusion defect, only 13% had normal motion whereas 87% had abnormal wall motion. The relation between perfusion and wall motion noted for the entire cohort was also present in subgroups of patients with anterior or inferior infarction. In patients with prior myocardial infarction, the severity of the tomographic thallium perfusion defect correlates directly with echocardiographically defined wall motion abnormalities, both globally and regionally.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1987

Estimation of myocardial infarct size by electrocardiographic and radionuclide techniques.

The Western Washington Intravenous Streptokinase in Acute Myocardial Infarction Trial was a randomized, experimental, multicenter clinical study comparing intravenous streptokinase therapy to conventional therapy of acute myocardial infarction. Myocardial infarct size was estimated by spatial vectorcardiography in 93 patients in the treatment group and 80 patients in the control group eight weeks post MI. The estimated infarct size for the treated group was smaller: 16 +/- 10% MI vs. 20 +/- 9% MI for the control group, P = 0.01. Four independent techniques to estimate infarct size were prospectively compared within the same day: Cowan's spatial VCG; the Selvestor/Wagner QRS score; 99m technetium synchronized ejection fractions and 201-Thallium Tomography. There was strong correlation between the two ECG techniques (r = 0.88) and between the two radionuclide techniques (r = 0.77). Statistically significant correlations (P = 0.0001) were described, respectively, among the four techniques, but the correlations were not clinically strong between electrocardiographic and radionuclide techniques: IAD vs. EF, r = -0.41; IAD vs. 201-Tl, r = 0.50; QRS Score vs. EF, r = -0.49; QRS Score vs. 201-Tl, r = 0.58.

Clinical Trials as Topic↗
PubMed1985

Left ventricular volume determination using single-photon emission computed tomography.

A new method for measuring left ventricular (LV) volume based on gated single-photon emission computed tomography (SPECT) is described. Preliminary phantom studies showed an excellent correlation between SPECT and observed volumes (r = 0.99, standard error of the estimate [SEE] = 4.9 ml). SPECT was performed 24 hours after biplane contrast LV angiography in 36 patients. Transaxial blood pool tomograms were reconstructed by filtered back projection and reoriented to views orthogonal to the cardiac axes. Volume was calculated from serial short-axis tomograms by determining the base, apex and lateral borders of the LV blood pool, ascertaining the number of pixels in this volume and multiplying by the known volume of a pixel. Gated SPECT volumes were compared with contrast angiographic volumes. At end-systole, r = 0.96 and SEE = 12 ml; at end-diastole, r = 0.81 and SEE = 27 ml. For ejection fraction, r = 0.85 and SEE = 0.06. To test interobserver variation in processing, count data from 5 patients were processed twice (r = 0.98, SEE = 8.3 ml). There is an excellent correlation between SPECT and contrast angiographic volumes at end-systole; at end-diastole the relation is good. SPECT requires no arbitrary background correction, allows systematic isolation of the left ventricle from other overlapping cardiac chambers and requires no geometric assumptions for volume determination. It has promise as a direct method for measuring LV volume in a minimally invasive manner.

Adult↗
PubMed1977

Evidence that the superoxide-generating system of human leukocytes is associated with the cell surface.

Superoxide anion (O-2-) generation by human peripheral blood polymorphonuclear leukocytes is enhanced when these cells encounter appropriate soluble or particulate stimuli. O-2- generation requires intact, viable cells and proceeds independently of phagocytosis. To investigate the possibility that the O-2--generating system is associated with the outer surface of the polymorphonuclear leukocyte plasma membrane, we have examined the effects upon O-2- production of p-diazobenzenesulfonic acid, a reagent which can react predominantly with proteins of the external cell membrane. When normal human polymorphonuclear leukocytes were preincubated with cytochalasin B (to minimize endocytosis) and then exposed to the surface-active lectin, concanavalin A, the cells were stimulated to generate O-2- in a concentration- and time-dependent fashion and selectively to discharge the granule-associated enzyme, lysozyme, into the surrounding medium. These responses, as well as cellular binding of [H] concanavalin A, could be blocked by alpha-methyl-D-mannoside. Brief treatment (less than 5 min at 4 degrees C) of the cells with p-diazobenzenesulfonic acid (1.0-5.0 mM) significantly interfered with concanavalin A-mediated O-2- generation but had no influence upon lysozyme release or upon binding of [3H] concanavalin A. The diazonium salt did not alter cell viability or the specific activity of the cytoplasmic enzyme, lactate dehydrogenase (inhibitable under conditions which allowed entry of this reagent into the cytosol). p-Diazobenzenesulfonic acid, therefore, very likely exerted its effects at the cell surface of the intact polymorphonuclear leukocyte, selectively inhibiting O-2- production (either directly or indirectly) without influencing another response to lectin-cell contact: release of lysozyme. These results support the possibility that a polymorphonuclear leukocyte ectoenzyme is responsible for O-2- production.

Azo Compounds↗