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Biomedical subjects

A Ramírez

Publications and source records attributed to A Ramírez.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The classification of coronary lesion from Society for Cardiac Angiography and Intervention predicts better results of coronary angioplasty than the one from American College of Cardiology/American Heart Association Coronary Disease].

BACKGROUND: The classification of coronary lesion complexity, using the American College of Cardiology/American Heart Association (ACC/AHA) is a predictor of balloon angioplasty success. Stents have improved results even in complex lesions. AIM: To compare the ACC/AHA and the new Society for Cardiac Angiography (SCA&I) coronary lesion scores as predictors of angioplasty success. PATIENTS AND METHODS: Ali consecutive angioplasty procedures (n = 346, 456 lesions, 47% stents) were prospectively analyzed from August 1996 to March 1999. Coronary lesions were classified using the ACC/AHA and SCA&I scores. Angiographic success was assessed and its multivariate predictors determined with logistic regression analysis. RESULTS: According to the ACC/AHA score, angiographic success was 97, 92.7, 93.3, and 82.3% in A, Bl, B2 and C lesions respectively (p = 0.013). There only were significant differences in success between C and A, Bl or B2 lesions. According to the SCA&I score success was achieved in 97.3, 97.9, 75.8 and 33.3% in nonCP, CP, nonCO and CO lesions respectively (P < 0.001). With the SCA&I score statistically significant differences in angiographic success were found for all lesion score comparisons, except between nonCP and CP lesions. No other variables had predictive value for angiographic success. CONCLUSIONS: Coronary angioplasty angiographic success is better predicted by the new SCA&l lesion score than with the ACC/AHA lesion classification in a group of patients with frequent use of stents.

Adult↗
PubMed2001

[Acute myocardial infarction caused by total occlusion of the left main coronary artery treated with percutaneous endoluminal revascularization. Clinical case].

We report a 43 years old female who developed an intense precordial pain and arterial hypotension. The patient was admitted to the emergency room in cardiogenic shock. An emergency angiography revealed a total occlusion of the left main coronary artery. An endoluminal coronary angioplasty with the placement of two stents was performed and coronary reperfusion TIMI III was achieved. The patient had a good evolution and one month later, a surgical revascularization was done, to avoid new occlusions. She was discharged in good conditions and in functional capacity I.

Adult↗
PubMed2001

[Comparative study of coronary angioplasty in diabetic patients. Immediate clinical and angiographic results and clinical evolution in the first year of follow up].

BACKGROUND: The success of revascularization procedures for coronary artery disease could be lower in diabetic patients. AIM: To report the results of coronary angioplasty in diabetic and non diabetic patients. PATIENTS AND METHODS: All angioplasty procedures performed between 1996 and 1999 were recorded. Demographic data, procedure details, hospital outcome and evolution at one year of follow up were analyzed. RESULTS: During the study period, 358 patients were treated; of these, 79 were diabetics. Despite the greater severity of coronary lesions among diabetic patients the clinical success of the procedure was 92.4% in diabetics and 91.8% in non diabetics. Hospital mortality was 1.3% in diabetics and 0.7% in non diabetics. Major complications occurred in 3.8% of diabetics and 3.2% in non diabetics. One year survival was 95.9% for diabetics and 98% in non diabetics. There were five late cardiac deaths among non diabetics and 3 among diabetics during the year of follow up. The frequency of new revascularization procedures was 4.3% in diabetics and 8.3% in non diabetics. Event-free survival was 95.6% in diabetics and 89.2% in non diabetics. CONCLUSIONS: Results of angioplasty were similar in diabetic and non diabetic patients in terms of hospital outcome and late follow-up.

Adult↗
PubMed2000

Implantation of bone marrow beneath the kidney capsule results in transfer not only of functional stroma but also of hematopoietic repopulating cells.

Renal ossicles are ossified structures developed after the implantation of a bone marrow (BM) plug beneath the kidney capsule. The authors have investigated the origin of the hematopoietic cells in murine renal ossicles by conducting sex-mismatched implants into Ly-5 congenic mice. BM plugs from transgenic mice provided additional genotypic tracers. Flow cytometry analyses on nonadherent cells from long-term cultures established with ossicles excised at 17 to 40 weeks postimplantation evidenced the presence of 5% to 70% of donor-derived myeloid cells. The genetic analysis of the day 12 colony-forming unit (CFU-S(12)) population in ossicles excised at 10 to 40 weeks postimplantation revealed that 16% to 93% of the colonies were of donor origin. Moreover, we describe for the first time the presence of long-term repopulating cells of donor origin in ossicles excised at 10 to 19 weeks postimplantation.

Animals↗
PubMed2000

An alternative to the reference method for testing the radiochemical purity of 99Tcm-tetrofosmin.

The recommended method for controlling the radiochemical purity (RCP) of 99Tcm-labelled tetrofosmin is thin-layer chromatography (TLC) with silica gel as the stationary phase and acetone:dichloromethane (35:65, v/v) as the mobile phase. However, this test is time-consuming and uses a toxic substance. We propose an alternative method to control RCP, based on a solid-phase extraction method (SPE) using a Sep Pak C18 cartridge. We used both methods to analyse 35 samples and to determine the percentages of colloid, radiopharmaceutical and free 99Tcm-pertechnetate. Normal labelling processes were modified to obtain a wide range of values. The range of RCP values obtained was 63.4-96.5% (median = 93.8%) by the standard TLC method and 70.1-96.4% (median = 94.1%) by the SPE method. A significant difference was observed only for the percentage of free 99Tcm-pertechnetate (P < 0.05). The agreement between the two methods, using 90% RCP as the limit, gave a kappa index = +1 (P < 0.001), indicating total agreement between them. The proposed method is useful to control RCP because it yields results that are in good agreement with those of the standard method, and because it is safer and less time-consuming.

Chromatography, Thin Layer↗
PubMed2000

Long term outcome of infective endocarditis in patients who were not drug addicts: a 10 year study.

OBJECTIVE: To determine the clinical features and long term prognosis of infective endocarditis in patients who were not drug addicts. DESIGN: Prospective case series. SETTING: A university hospital that is both a referral and a primary care centre. PATIENTS: 138 consecutive cases of infective endocarditis diagnosed and treated from January 1987 to March 1997. RESULTS: Mean patient age was 44 (20) years old. 95 patients (69%) had native valve endocarditis and 43 (31%) had prosthetic valve endocarditis. Staphylococci were the causal microorganisms in 34% of cases and streptococci in 33%. Severe complications occurred in 83% of patients and 51% of patients underwent surgery during the active phase (22% was emergency surgery). Inpatient mortality was 21%. During a follow up of 56 (44) months, 10 patients (9%) needed late cardiac surgery and seven (5% of the whole series) died. Overall 10 year survival was 71%. There were no significant differences in survival depending on the type of treatment received during the hospital stay (medical or combined medical-surgical). CONCLUSIONS: A high early surgery rate is related to good long term results and does not increase in-hospital mortality. Medical treatment, however, also offers favourable long term results in cases of responsive infective endocarditis where poor prognostic factors are absent.

Adult↗
PubMed2000

Splice variants of a ClC-2 chloride channel with differing functional characteristics.

We identified two ClC-2 clones in a guinea pig intestinal epithelial cDNA library, one of which carries a 30-bp deletion in the NH(2) terminus. PCR using primers encompassing the deletion gave two products that furthermore were amplified with specific primers confirming their authenticity. The corresponding genomic DNA sequence gave a structure of three exons and two introns. An internal donor site occurring within one of the exons accounts for the deletion, consistent with alternative splicing. Expression of the variants gpClC-2 and gpClC-2Delta77-86 in HEK-293 cells generated inwardly rectifying chloride currents with similar activation characteristics. Deactivation, however, occurred with faster kinetics in gpClC-2Delta77-86. Site-directed mutagenesis suggests that a protein kinase C-mediated phosphorylation consensus site lost in gpClC-2Delta77-86 is not responsible for the observed change. The deletion-carrying variant is found in most tissues examined, and it appears more abundant in proximal colon, kidney, and testis. The presence of a splice variant of ClC-2 modified in its NH(2)-terminal domain could have functional consequences in tissues where their relative expression levels are different.

Alternative Splicing↗
PubMed2000

Quadriceps atrophy after knee traumatisms and immobilization: electrophysiological assessment.

Automatic analysis of EMG (T/A analysis) and invasive muscle fiber conduction velocity in situ (MFCV) were performed in 15 patients after traumatic lesions of the knee and immobilization with quadriceps atrophy. T/A analysis showed transient reduced number of turns, consistent with inhibition of quadriceps motoneurons, that recovered within the first 2 weeks after the plaster cast had been removed. MFCV was significantly slowed and showed a gradual improvement, reaching normal values after 6 weeks. These results suggest that decrement in activated motor units may be the cause of the disproportionate weakness of the quadriceps muscle on the first days after immobilization by the plaster cast. The recovery of MFCV was related with functional improvement of strength after the first weeks.

Adult↗
PubMed2000

Loss- and gain-of-function mutations show a polycomb group function for Ring1A in mice.

The products of the Polycomb group (PcG) of genes act as transcriptional repressors involved in the maintenance of homeotic gene expression patterns throughout development, from flies to mice. Biochemical and molecular evidence suggests that the mouse Ring1A gene is a member of the PcG of genes. However, genetic evidence is needed to establish PcG function for Ring1A, since contrary to all other murine PcG genes, there is no known Drosophila PcG gene encoding a homolog of the Ring1A protein. To study Ring1A function we have generated a mouse line lacking Ring1A and mouse lines overexpressing Ring1A. Both Ring1A(-/-)and Ring1A(+/-) mice show anterior transformations and other abnormalities of the axial skeleton, which indicates an unusual sensitivity of axial skeleton patterning to Ring1A gene dosage. Ectopic expression of Ring1A also results in dose-dependent anterior transformations of vertebral identity, many of which, interestingly, are shared by Ring1A(-/-) mice. In contrast, the alterations of Hox gene expression observed in both type of mutant mice are subtle and involve a reduced number of Hox genes. Taken together, these results provide genetic evidence for a PcG function of the mouse Ring1A gene.

Animals↗
PubMed2000

[Heart failure caused by severe systolic ventricular dysfunction of hypertensive origin. Long-term clinical and functional course].

AIMS: The aims of our study were to evaluate survival and evolution of functional class and ventricular function in patients with severe congestive heart failure due to dilated cardiomyopathy. METHODS: Inclusion criteria were: class III or IV heart failure, dilated left ventricle with ejection fraction < 40%, history of poor controlled hypertension, and exclusion of other etiologies for heart failure. We studied 17 patients with these features; mean age was 64 +/- 7 years and 70% were male. They were followed up during a mean period of 3.3 +/- 1 years (2 to 6; median 3 years). RESULTS: Baseline left ventricular ejection fraction was 30 +/- 5% (20 to 40); 35% of patients were in functional class III and 65% in class IV; 100% of patients received ACE inhibitors and diuretics, 53% betablockers, and 35% calcium-antagonists. Survival was 100%. Left ventricular ejection fraction increased from 30 +/- 5% to 44 +/- 11% at one year, to 50 +/- 11% at 3 years and 51 +/- 10% at the end of follow-up (p < 0.001). This improvement was mainly due to a reduction in systolic left ventricular diameter (from 51 +/- 4 mm to 42 +/- 11 mm, p < 0.01), since diastolic diameter did not significantly changed (63 +/- 4 to 59 +/- 11 mm). CONCLUSIONS: The evolution of severe systolic left ventricular dysfunction due to arterial hypertension is favourable at long-term, with null mortality and clinical ejection fraction and functional improvement. Nevertheless, the persistence of left ventricular dilatation suggests that myocardial damage caused by chronic pressure overload does not disappear.

Aged↗
PubMed2000

[Electrophoretic study of albumins and globulins of 4 genotypes of Canavalia ensiformis].

Polyacrylamide gel electrophoresis (PAGE) and PAGE-SDS were used to study seed albumins and globulins of Canavalia ensiformis. In PAGE the concentration of acrylamide used in the upper gel was 4.0% with a pH of 6.7 and in the lower gel 7.5% and 10% of acrylamide were used with a pH of 8.9. In PAGE-SDS the concentration of acrylamide was 4.4% with a pH of 6.8 in the upper gel and 7.5% and 12.6% with a pH of 8.8 in the lower gel. The material used were the Venezuelan genotypes Tovar, Yaracuy, Original and U-02. The albumins and globulins were extracted with a 0.5 M NaCl solution and then separated by dialysis against water and lyophilized. These protein fractions represented 84.85% of the total amount of protein in seeds. The albumins were separated in PAGE with 7.5% acrylamide into five fractions and globulins into six, with similar electrophoretic patterns between genotypes. In a similar manner, the patterns obtained in PAGE with 10% acrylamide were the same for all genotypes, showing five bands for albumins and three bands for globulins. With PAGE-SDS containing 7.5% of acrylamide, albumins were separated into as many as eight components, and globulins into as many as seven bands with mobilities between 0.2981 and 0.9932, with different patterns for each genotype. Also the patterns PAGE-SDS at 12.6% of acrylamide were different for the genotypes, separating proteins into a greater number of bands. The albumins showed as many as twenty-one bands with mobilities between 0.2603 and 0.7398, and globulins as many as sixteen bands with mobilities between 0.2454 and 0.7390. The PAGE patterns of the genotypes analyzed did not show differences between them. However, with PAGE-SDS different electrophoretic patterns were obtained which varied in the number and intensity of the bands, making it possible to distinguish the genotypes studied. The molecular weight of the albumins varied between 76,000 and 12,000 daltons and of the globulins between 80,000 and 12,000 daltons.

Albumins↗
PubMed2000

Percutaneous balloon-expandable stents for sealing of acute aortic dissection.

Acute aortic dissection is a highly lethal disease. When dissection involves only the descending aorta and there are no ischemic complications, medical management may be the treatment of choice. However, a high risk of expansion or rupture of the dissection remains. When renal or limb ischemic complications do appear, surgery has been the only option, despite high mortality and morbidity. Percutaneous placement of stents for sealing an acute aortic dissection might be an alternative to surgical treatment. We treated 2 patients with acute type B aortic dissection by stent-fixation of the proximal and distal descending aorta. In both patients, there was evidence of persistent flap fixation at midterm follow-up.

Acute Disease↗
PubMed2000

[Secondary ionizing radiation generated by digital and analog coronary cineangiographic equipment: influence of external systems of radiologic protection].

BACKGROUND: Exposure to ionizing radiation is a known hazard of radiological procedures. AIM: To compare the emission of secondary ionizing radiation from two coronary angiographic equipment, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. MATERIAL AND METHODS: Environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique projection (ALO) and in anterior right oblique projection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. RESULTS: Header radiation for groups 1 and 2 was 1194 +/- 337 and 364 +/- 222 microGray/h respectively (p < 0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612 +/- 947 and 70 +/- 61 microGray/h respectively (p < 0.001). For ALO projection, generated radiation for groups 1 and 2 was 105 +/- 47 and 71 +/- 192 microGray/h respectively (p < 0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252 +/- 9569 and 1671 +/- 2038 microGray/h respectively (p = 0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800 +/- 1741 and 1318 +/- 954 microGray/h respectively (p < 0.001); during filming, the figures were 15,500 +/- 5840 and 18,961 +/- 10,599 microGray/h respectively (NS). CONCLUSIONS: Digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment.

Adult↗
PubMed2000

[SPECT tomography with F 18-fluorodeoxyglucose in a recent myocardial infarction clinical case].

We report a 50-year-old woman with a recent myocardial infarction in whom a myocardial perfusion single photon emission computed tomography (SPECT) with Thallium201 was done simultaneously with a F18-fluorodeoxyglucose (FDG) SPECT to study glucose metabolism. Myocardial infarction was located in the anteroseptal and apical regions and an echocardiography, done at the second day of evolution, showed a septo-apical hypokinesia. On the tenth day, a coronary angiography showed a critical lesion of the anterior descending coronary artery and an angioplasty with stent placement was performed on the next day. On the twelfth day, a resting, redistribution 201Tl SPECT to study viability and a FDG-SPECT with a dual head high-energy collimator camera were done. Images, acquired 45 min after injection, were analyzed visually. In anterior and medial apical sectors, discordance between flux and metabolism, considered a classical mismatch, was observed. Echocardiographic hypokinesia disappeared three month after revascularization.

Female↗
PubMed1999

Simple and complex stent strategies for bifurcated coronary arterial stenosis involving the side branch origin.

Coronary lesions located in major bifurcations constitute a challenge for the use of stents. Although the occlusion of a side branch covered by a stent is infrequent, the maintenance of a patent, stenosis-free bifurcation may result in a complex procedure. Between September 1994 and April 1998, 70 patients were treated by stent implantation for coronary bifurcation stenosis. The side branch always had a diameter >2 mm. The pairs of treated arteries were: left anterior descending (LAD)/diagonal artery in 32 patients, circumflex/obtuse marginal in 26, right coronary/posterior descending artery in 5, and LAD/circumflex in 7. We applied 2 different techniques of stent implantation: (1) deployment of 1 stent in the parent vessel covering the takeoff of the side branch and subsequent angioplasty of the side branch across the metallic structure (group A, n = 47 patients), and (2) implantation of 1 stent at the ostium of the side branch and complete reconstruction of the entire bifurcation with additional implantation of 1 or 2 stents at the parent vessel (group B, n = 23 patients). There were no significant differences between groups at baseline variables. Procedural success was similar in both groups: 42 (89%) in group A versus 21 (91%) in group B. However, major cardiac events at 18 months follow-up were higher in group B (event-free probability 44% vs 75%, p <0.05). Selected patients with coronary stenosis at major bifurcations can be treated with an acceptable rate of primary and late success. Complex techniques providing radical stent reconstruction of the bifurcation seems to provide no advantages over the simpler stent jail followed by ostial side branch balloon dilation.

Aged↗
PubMed1999

Tumour necrosis factor-alpha and interleukin-1 and -6 in fibrocystic breast disease.

The risk of developing breast cancer is higher in women presenting gross cystic disease (cysts > 3 mm in diameter) of the breast with intracystic K+/Na+ > 3 as compared with K+/Na+ < 3. The present study reports the levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6) in the breast cyst fluid of women with gross cystic disease and analyses the relationship between the intracystic concentration of these cytokines, sex steroid hormones, and the K+/Na+ ratio. The concentration of these cytokines, estradiol, testosterone, dehydroepiandrosterone sulfate (DHEA-S), and 17-OH-progesterone were determined in the breast cyst fluid of 54 women with gross cystic disease. No significant differences were found in the cystic levels of IL-1 between cysts with intracystic K+/Na+ < 3 and > 3. However, in cysts with intracystic K+/Na+ > 3 we found a lower concentration of IL-6 and TNF-alpha than in those with intracystic K+/Na+ < 3. Stepwise multiple linear regression analysis demonstrated that the concentration of IL-6 in breast cyst fluid was predicted statistically by a negative regression coefficient for the concentration of estradiol and DHEA-S, and by a positive regression coefficient for the concentration of TNF-alpha. The concentration of TNF-alpha in breast cyst fluid was predicted statistically by a positive regression coefficient for the concentration of IL-6, and by a negative regression coefficient for the concentration of estradiol. No candidate variable was included in the model to predict concentrations of IL-1 in breast cyst fluid. Our results indicate that IL-6 and TNF-alpha could have a local 'protector' role in gross cystic disease, and that they could be used as a marker to identify cyst type.

17-alpha-Hydroxyprogesterone↗