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Biomedical subjects

R Moreno

Publications and source records attributed to R Moreno.

At least 37 records · Page 2Linked to original sources
PubMed2002

Usefulness of contrast agents in the diagnosis of left ventricular pseudoaneurysm after acute myocardial infarction.

BACKGROUND AND OBJECTIVE: The diagnosis of left ventricular pseudoaneurysm after acute myocardial infarction is usually based on echocardiography. However, this technique may have limitations in some patients, especially in cases with suboptimal acoustic window. The objective of this study was to evaluate the usefulness of contrast echocardiography in the diagnosis of left ventricular pseudoaneurysm after myocardial infarction. METHODS AND RESULTS: The study population comprises six patients in whom a two-dimensional echocardiography showed an image consistent with left ventricular pseudoaneurysm. Levovist (Schering) 4gr was administered i.v. to more clearly visualize the blood flow from the left ventricle to the left ventricular pseudoaneurysm cavity in all patients. Infarct location was anterior in five patients, and posterolateral in one. No patient had received thrombolysis or primary angioplasty during the acute phase. The transthoracic echocardiographic study showed an echo-free space adjacent to left ventricle in all patients. In four cases, the diagnosis of left ventricular pseudoaneurysm was made before contrast administration. In the remaining two patients, the definite diagnosis was made only after Levovist administration. CONCLUSION: In the diagnosis of postinfarction left ventricular pseudoaneurysm, the administration of contrast agents may be of help in the correct visualization of the blood flow from the left ventricle to the left ventricular pseudoaneurysm cavity, and may allow a definite diagnosis to be obtained in some patients.

Aged↗
PubMed2002

Congenital quadricuspid aortic valve associated with congenital complete heart block.

Congenital quadricuspid aortic valve is very uncommon, and is often associated with other cardiac disorders, such as patent ductus, ventricular septal defect, pulmonary stenosis, mitral valve malformation, hypertrophic cardiomyopathy and coronary abnormalities. We report a patient with congenital quadricuspid aortic valve associated with congenital complete heart block. To our knowledge, this association has not been reported so far.

Adult↗
PubMed2002

Weak concordance between wall motion and microvasculature status after acute myocardial infarction: study with myocardial contrast echocardiography in real time with power modulation.

AIMS: The microvasculature damage after myocardial infarction has important implications. The hypothesis of the study was that wall motion abnormalities and microcirculation status do not necessarily match after myocardial infarction, and therefore the study of only myocardial wall motion could offer an incomplete evaluation in these patients. METHODS: Wall motion and myocardial perfusion assessed by contrast echocardiography were evaluated by two different blinded investigators in 29 patients with recent (<1 week) myocardial infarction. Myocardial perfusion was assessed in real-time using power modulation after Optison (1.5-3.0 ml) intravenous administration. RESULTS: One hundred and ninety-nine segments could be adequately evaluated. Of these, 54 (27%) were akinetic. Regarding contrast opacification, 134 segments (67%) had a normal perfusion, whereas the remaining 65 (33%) had an impaired (n=37, 19%) or absent (n= 28, 14.1%) perfusion. Concordance between presence of akinesia and abnormal contrast opacification was only moderate (kappa index 0.42) and agreement only occurred in 116 segments (58%). Fourteen per cent of normoquinetic segments had an impaired perfusion, whereas 35% of akinetic segments had a preserved perfusion. Correlation between the proportion of segments with akinesia and the proportion of segments with impaired perfusion was moderate (r=0.41), and there was no correlation between the proportion of segments with akinesia and the percentage of segments with absent perfusion. CONCLUSION: There is a weak association between regional systolic function and myocardial perfusion after myocardial infarction, as assessed by real-time contrast myocardial echocardiography using power modulation.

Aged↗
PubMed2002

Genetic marker variation in coastal populations of Chile.

Gene frequencies for nine genetic marker systems are presented for the following Chilean coastal populations: Paposo, Carelmapu, Laitec and Ukika. Historical and anthropological data suggest the presence of descendants of the Amerindian populations, specifically of Changos, Cuncos, Chonos and Yamanas in these populations. Results indicate that the studied groups maintain an important aboriginal genetic composition. According to Amerindian admixture estimates, the genetic isolation of coastal populations is lower than that of inland populations, suggesting that proximity to the sea facilitated gene flow. Genetic distances and dendrograms were obtained for these populations and another four Chilean Indian populations. Results agree with expectations, taking geographic isolation and non-aboriginal admixture into account.

Chile↗
PubMed2001

Exploiting conformationally constrained peptidomimetics and an efficient human-compatible delivery system in synthetic vaccine design.

Peptide and protein mimetics are potentially of great value in synthetic vaccine design. The mimetics should function by stimulating the immune system to produce antibodies that recognize the intact parasite. Also the mimetics should be presented to the immune system in a way that leads to efficient antibody production. Here we investigate the application of cyclic peptidomimetics presented on immunopotentiating reconstituted influenza virosomes (IRIVs), a form of antigen delivery that is licensed already for human clinical use, in synthetic vaccine design. We focus on the central (NPNA)(n) repeat region of the circumsporozoite (CS) protein of the malaria parasite Plasmodium falciparum as a model system. Cyclic peptidomimetics of the NPNA repeats were incorporated into both an IRIV and (for comparison) a multiple-antigen peptide (MAP). Both IRIV and MAP delivery forms induced mimetic-specific humoral immune responses in mice, but only with the mimetic-IRIV preparations did a significant fraction of the elicited antibodies cross-react with sporozoites. The results demonstrate that IRIVs are a delivery system suitable for the efficient induction of antibody responses against conformational epitopes by use of cyclic template-bound peptidomimetics. Combined with combinatorial chemistry, this approach may have great potential for the rapid optimization of molecularly defined synthetic vaccine candidates against a wide variety of infectious agents.

Animals↗
PubMed2001

Export of Thermus thermophilus alkaline phosphatase via the twin-arginine translocation pathway in Escherichia coli.

The bacterial twin-arginine translocation (Tat) pathway is distinct from the Sec system by its remarkable capacity to export folded enzymes. To address the question whether the two systems are capable of translocating homologous enzymes catalyzing the same reaction, we cloned the tap gene encoding Thermus thermophilus alkaline phosphatase (Tap) and expressed it in Escherichia coli. Unlike the alkaline phosphatase of E. coli, which is translocated through the Sec system and then activated in the periplasm, Tap was exported exclusively via the Tat pathway and active Tap precursor was observed in the cytoplasm. These results demonstrate that two sequence and functional related enzymes are exported by distinct protein transport systems, which may play an integral role in the bacterial adaptation to their environment during the evolution.

Alkaline Phosphatase↗
PubMed2001

Outgassing behavior and composition of comet C/1999 S4 (LINEAR) during its disruption.

The gas activity of comet C/1999 S4 (LINEAR) was monitored at radio wavelengths during its disruption. A runaway fragmentation of the nucleus may have begun around 18 July 2000 and proceeded until 23 July. The mass in small icy debris (</=30-centimeter radius) was comparable to the mass in the large fragments seen in optical images. The mass budget after breakup suggests a small nucleus ( approximately 100- to 300-meter radius) that had been losing debris for weeks. The HNC, H2CO, H2S, and CS abundances relative to H2O measured during breakup are consistent with those obtained in other comets. However, a deficiency in CH3OH and CO is observed.

Journal Article↗
PubMed2001

Long-term outcome of patients with proximal left anterior descending coronary artery in-stent restenosis treated with rotational atherectomy.

Once a first interventional procedure has failed, patients with proximal left anterior descending in-stent restenosis are frequently sent for surgical revascularization. Data on long-term outcome in selected patients with proximal left anterior descending in-stent restenosis treated with RA are lacking. The study's objective was to evaluate the long-term outcome of patients with proximal left anterior descending artery in-stent restenosis treated with rotational atherectomy. The study population is constituted by 42 patients with proximal left anterior descending in-stent restenosis treated with rotational atherectomy. Patients were followed up for 2.1 +/- 0.9 years (range, 6--54). Restenosis length was 16.5 +/- 9.2 mm, and restenosis was diffuse (> 10 mm in length) in 30 (71.4%). The rotational atherectomy procedure was guided by intravascular ultrasound in 18 patients (42.9%). Maximum burr/artery ratio was > 0.7 in 24 (57.1%) patients. One patient suffered a periprocedural non--Q-wave infarction, but no deaths, Q-wave infarction, or new target vessel revascularization occurred during hospitalization. There were no deaths or myocardial infarctions after discharge. Sixteen patients (38.1%) needed a new revascularization, but only five (11.9%) underwent coronary bypass grafting at the end of the follow-up (2.1 +/- 0.9 years). The rate of surgical revascularization at 6 months, 1 year, and 3 years was 4.8%, 7.4%, and 18.4%, respectively. The rate of new target vessel revascularization at 6 months, 1 year, and 3 years was 16.7%, 36.5%, and 40.5%, respectively. Patients with < or = 5 months since stent implantation had a significantly higher rate of new target vessel revascularization. Patients with proximal left anterior descending in-stent restenosis may be safely treated with rotational atherectomy. This strategy is associated with a very good long-term outcome, with few patients undergoing surgical revascularization.

Adult↗
PubMed2001

Mortality after discharge from intensive care: the impact of organ system failure and nursing workload use at discharge.

OBJECTIVES: Mortality after ICU discharge accounts for approx. 20-30% of deaths. We examined whether post-ICU discharge mortality is associated with the presence and severity of organ dysfunction/failure just before ICU discharge. PATIENTS AND METHODS: The study used the database of the EURICUS-II study, with a total of 4,621 patients, including 2,958 discharged alive to the general wards (post-ICU mortality 8.6%). Over a 4-month period we collected clinical and demographic characteristics, including the Simplified Acute Physiology Score (SAPS II), Nine Equivalents of Nursing Manpower Use Score, and Sequential Organ Failure Assessment (SOFA) score. RESULTS: Those who died in the hospital after ICU discharge had a higher SAPS II score, were more frequently nonoperative, admitted from the ward, and had stayed longer in the ICU. Their degree of organ dysfunction/failure was higher (admission, maximum, and delta SOFA scores). They required more nursing workload resources while in the ICU. Both the amount of organ dysfunction/failure (especially cardiovascular, neurological, renal, and respiratory) and the amount of nursing workload that they required on the day before discharge were higher. The presence of residual CNS and renal dysfunction/failure were especially prognostic factors at ICU discharge. Multivariate analysis showed only predischarge organ dysfunction/failure to be important; thus the increased use of nursing workload resources before discharge probably reflects only the underlying organ dysfunction/failure. CONCLUSIONS: It is better to delay the discharge of a patient with organ dysfunction/failure from the ICU, unless adequate monitoring and therapeutic resources are available in the ward.

APACHE↗
PubMed2001

Diversity among clinical isolates of penicillin-resistant Streptococcus mitis: indication for a PBP1-dependent way to reach high levels of penicillin resistance.

A total of 12 non-epidemiologically related clinical isolates of Streptococcus mitis that showed different levels of resistance to penicillin were studied. Membrane-protein profiles and penicillin-binding protein (PBP) patterns showed a great polymorphism; and patterns of 4-7 PBPs, with sizes that ranged from approximately 101 kDa to approximately 40 kDa, were detected in each strain. No association could be found between PBP pattern and resistance level to penicillin among these isolates. Arbitrarily primed PCR confirmed the genetic diversity among this group of streptococci. One of the isolates of intermediate level of resistance to penicillin, which showed a PBP pattern similar to that of the high-resistance strains, was used as a laboratory model to analyse the mechanism underlying high-resistance acquisition by these strains. A 14-fold increase in penicillin resistance was obtained after a single selection step, which resulted in a decrease in penicillin affinity for PBP1. The size of this PBP (92 kDa) and the differences in PBP profiles of the penicillin-resistant clinical isolates suggest the existence in S. mitis of PBP-mediated mechanisms to acquire high-level resistance to penicillin, among which alterations in PBP1 seem to play a main role, in contrast to the PBP2X mediated mechanism described for other streptococci.

Bacterial Proteins↗
PubMed2001

[Utility of SPECT with 99m Tc-tetrofosmin and stimulus with dipyridamole in patients with permanent ventricular pacemakers].

BACKGROUND AND OBJECTIVE: Patients with permanent ventricular pacemakers (PP) are a difficult subgroup to assess in the study of coronary artery disease. The objective of this study was to evaluate the diagnostic value of the myocardial perfusion scintigraphy with 99mTC-Tetrofosmin (Tc-Tf) and stimulus with dipyridamole in patients with PP and suspected coronary artery disease. PATIENTS AND METHODS: Fourteen patients with suspected coronary artery disease and without structural cardiopathy, who underwent Tc-Tf and cardiac catheterization, were studied retrospectively. Sensitivity, specificity, predictive values and Kappa index were calculated for the diagnosis of coronary artery disease, multivessel disease, and for each one of the coronary arteries (left anterior descending, right coronary, and circumflex). In addition, the correlation between the number of territories with perfusion defects and the number of diseased vessels was studied. RESULTS: In regards to the diagnosis of coronary artery disease, sensitivity, specificity, positive predictive value, negative predictive value and the Kappa index were 100%, 50%, 83%, 100% and 0.55, respectively. For multi-vessel disease, these values were 83%, 64%, 64%, 83% and 0.43 respectively. The correlation coefficient between the number of territories with perfusion defects and the number of diseased vessels was 0.61 (p = 0.02). In the diagnosis of anterior descending disease, sensitivity and specificity were 83% and 88% respectively. For the right coronary artery, these values were 100% and 44% and for the circumflex artery 38% and 83%, respectively. CONCLUSION: In patients with PP and suspected coronary artery disease, myocardial perfusion scintigraphy with Tc-Tf and stimulus with dipyridamole is of great value in the diagnosis of coronary artery disease and in the assessment of its extension.

Aged↗
PubMed2001

[In-hospital major complications associated with rotational atherectomy: experience with 800 patients at a single center].

INTRODUCTION: Rotational atherectomy is usually performed in patients with angiographically determined high risk coronary lesions. The aim of this study was to evaluate the rate of major adverse cardiac events (death, Q-wave infarction or new revascularization) after rotational atherectomy, as well as to identify the clinical characteristics associated with this incidence. PATIENTS AND METHODS: The study population included 800 patients treated with rotational atherectomy from 1993 to 1999: 512 (64%), for de novo lesions, and 288 (36%) for restenosis. Balloon dilation and coronary stenting was performed in 95% and 34% of patients, respectively. RESULTS: During hospitalization, 17 patients (2.1%) died, 16 (2%) had a Q-wave infarction, 30 (3.8%) a non-Q infarction, and new revascularization was performed in 28 (3.5%). The incidence of major adverse cardiac events was 6.5% (n = 52), this incidence being higher in the presence of diabetes (8.9 vs. 4.4%; p = 0.01), unstable angina or acute/recent myocardial infarction (7.6 vs. 3.3%; p = 0.02), multivessel disease (8.6 vs. 3.3%; p < 0.01), treated vessel other than right coronary (7.0 vs. 1.7%; p = 0.01), procedure in > 1 vessel (10.7 vs. 4.7%; p < 0.01), angiographic failure (62.5 vs. 5.5%; p < 0.001), and de novo lesions (8.4 vs. 2.5%; p < 0.01), with diabetes and treatment of de novo lesions being independent predictors of major adverse cardiac events. However, age, previous infarction, and left ventricular dysfunction, were not associated with the rate of events. CONCLUSION: Some simple variables are associated with a higher incidence of major adverse cardiac events after rotational atherectomy. Advanced age, previous infarction and left ventricular dysfunction, however, do not necessarily imply a poorer prognosis in these patients.

Aged↗
PubMed2001

[Regional diastolic function is more preserved in viable than non-viable myocardium. Demonstration by pulsed-wave Doppler tissue imaging in basal conditions].

INTRODUCTION AND OBJECTIVES: The aim of this study was to analyze the differences in regional diastolic function between viable and non-viable myocardium when assessed by pulsed-wave Doppler tissue imaging performed in basal conditions. PATIENTS AND METHODS: The study population included 21 patients with three-vessel disease and regional systolic dysfunction. These patients underwent transthoracic echocardiographic study and pulsed-wave Doppler tissue imaging in basal conditions and, in addition, stress echocardiography with dobutamine performed by a different investigator. RESULTS: Three-hundred and twenty-two segments were studied, 140 of which (43%) had systolic dysfunction. Of the 140 segments with systolic dysfunction, 52 (37%) were considered hypokinetic by transthoracic echocardiography, 80 (57%) akinetic and 8 (6%) dyskinetic. As assessed by dobutamine echocardiography, 67 segments (48%) were considered viable and 73 (52%) non-viable. Viable segments had a higher peak velocity of the early diastolic wave e (5.5 +/- 1.9 vs. 4.7 +/- 2.0 cm/s; p = 0.03). An e/a ratio < 1 was more frequent in non-viable versus non-viable segments (52 vs. 70%; p < 0.05). There were no differences in relation to regional isovolumetric relaxation time and peak velocity of a wave. Although peak velocity of s wave was lower in non-viable segments, differences were not statistically significant. CONCLUSION: Compared with non-viable segments, viable myocardial segments have less impaired regional diastolic function as assessed by pulsed-wave Doppler tissue imaging.

Echocardiography, Doppler, Pulsed↗
PubMed2001

[Treatment of acute myocardial infarction with the x-sizer coronary thrombectomy device].

The abundant thrombi present in infarct-related arteries may impair the angiographic result of primary angioplasty in acute myocardial infarction. We describe the utilization of the thrombus-removal device X-Sizer before coronary stenting in 4 patients with acute myocardial infarction treated with primary angioplasty. The procedure was successful in all the cases and the patients were discharged without complications.

Aged↗