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Biomedical subjects

A Domingo

Publications and source records attributed to A Domingo.

At least 37 records · Page 2Linked to original sources
PubMed1999

Behaviour of bone allografts in the advancement of the tibial tuberosity.

In order to determine the behaviour of bone allografts in the advancement of the tibial tuberosity, we studied retrospectively 134 knees belonging to 119 recipients of frozen bone allograft for the treatment of a symptomatic patellofemoral osteoarthrosis. All patients had a 1.2-1.5 cm tibial tuberosity advancement with a release of the lateral patellar retinacula and no other additional surgery. Total incorporation of grafts took place in 116 cases (86.6%); graft resorption appeared in 16 patients (11.9%)(total resorption 3, and partial resorption 13). No disease transmission has been detected. To avoid donor site morbidity associated with harvesting iliac crest, the use of frozen bone allograft is a good alternative in the advancement of the tibial tuberosity.

Adult↗
PubMed1998

Differential uptake of myocardial perfusion radiotracers in normal, infarcted, and acutely ischemic peri-infarction myocardium.

OBJECTIVES: We measured the uptake of technetium-99m tetrofosmin (99m Tc) and thallium-201 (201 TI) in areas of healed transmural myocardial infarction and in the regions of acute peri-infarction ischemia. METHODS: Anesthetised pigs with a 1-month old transmural infarction elicited by permanent ligature of the left anterior descending (LAD) coronary artery below the first branch underwent one hour of proximal LAD occlusion followed by injection of 99m Tc-tetrofosmin and 201TI either in the left atrium (GI, n= 19) or in the jugular vein (GII, n = 6). Twelve other pigs (GIII) with similar acute peri-infarction ischemia received 99m Tc-tetrofosmin and 201Tl into the left ventricle during cardiocirculatory arrest to rule out the effect of coronary collaterals. Radiotracer counting was determined in samples from normal, acute ischemic and necrotic regions. RESULTS: Uptake of 99m Tc-tetrofosmin and 201 Tl was greater in the infarct scar (median % of normal tissue: 20 for 99m Tc and 8.6 for 201 Tl in GI; 22 and 15 in GII) than in acute ischemic myocardium (3.2 and 2.5 in GI; 6.4 and 3.3 in GII). Radiotracer injection in arrested hearts (GIII) depicted a similar pattern (median % of injected dose: 6.2 for 99m Tc and 10 for 201Tl in the scar; 2.3 and 4.0 in acute ischemia; 2.9 and 3.5 in normal tissue). The infarcted region showed connective tissue and lack of viable myocardium. CONCLUSION: A 1-month old infarct scar with no viable myocardial tissue can take up significant fractions of 99mTc-tetrofosmin and 201Tl even in the absence of coronary collateral perfusion. Data suggest that the infarct scar can extract these radiotracers from the intraventricular blood.

Animals↗
PubMed1998

Passive transmission of ischemic ST segment changes in low electrical resistance myocardial infarct scar in the pig.

OBJECTIVES: To analyze the passive electrical properties of a healed infarction and assess their role on transmission of contiguous ischemic ST segment potential changes. METHODS: We measured tissue resistivity (omega cm) at 1 kHz and the epicardial ST segment during 1 h of proximal reocclusion of the left anterior descending (LAD) coronary artery in 12 anesthetized pigs with one-month-old transmural infarction elicited by LAD ligature below the first branch. The impedance spectrum (1 to 1000 kHz) of normal and infarcted myocardium was measured in seven other pigs with similar infarctions. Electrical transmission of current pulses (30 microA) in infarcted tissue and in test solutions was also investigated. RESULTS: The infarct scar has a lower than normal resistivity (110 +/- 30 omega cm vs. 235 +/- 60 omega cm, p < 0.0001) and, unlike the normal myocardium, resistivity and phase angle of the scar did not change at increasing current frequencies, reflecting no capacitative response. LAD reocclusion induced a resistivity rise (510 +/- 135 omega cm, p < 0.01) and a ST segment elevation (0.6 +/- 0.7 to 9.5 +/- 5.1 mV, p = 0.002) in the ischemic peri-infarction zone, whereas the infarcted area showed ST segment elevation (0.5 +/- 0.5 to 3.8 +/- 2.6 mV, p = 0.03) with no resistivity changes. Potential decay of both ST segment and current pulses in the scar and in 0.9% NaCl solution was less than 1 mV/mm. Transmural deposition of connective tissue was seen in the center of the infarction. CONCLUSIONS: A one-month-old transmural infarction is a low resistance, noncapacitative medium that allows a good transmission of current pulses and of ST segment potential changes generated by contiguous peri-infarction ischemia.

Animals↗
PubMed1998

Troponin-T is a calcium-binding protein in insect muscle: in vivo phosphorylation, muscle-specific isoforms and developmental profile in Drosophila melanogaster.

Two sets of muscle polypeptides showing calcium-binding capacity and intense labelling in vivo with 32P were purified and characterized from Drosophila melanogaster adult extracts. The polypeptides exhibit crossed immunoreactivity and share similar biochemical properties such as those involved in purification. They have been identified as isoforms of troponin-T (TnT) by sequence analysis of a cDNA clone isolated from an embryonic library. The two sets of TnT polypeptides correspond to the fibrillar and non-fibrillar muscle isoforms, respectively. The non-fibrillar muscle isoforms separate into two bands which are differentially expressed during development. Analysis of TnT isoforms in bee thoraces indicates that the expression of the fibrillar muscle isoform correlates with the acquisition of functional flight capability. In vivo labelling experiments reveal that the two TnT sets are readily phosphorylated. The Drosophila TnTs show calcium-binding properties by three different types of assays. Our results suggest that this property could be specific to insect TnTs and may be related to the long, extremely acidic polyglutamic carboxy-terminus present in these polypeptides, which does not occur in non-arthropod TnTs.

Amino Acids↗
PubMed1998

Sex differences in mortality of people who visited emergency rooms for asthma and chronic obstructive pulmonary disease.

We assess the sex differences in mortality in a population-based cohort of those Barcelona residents older than 14 yr of age who received emergency room services (ERS) for either chronic obstructive pulmonary disease (COPD) or asthma, during the period from 1985 to 1989. Vital status was followed to the end of 1995. A total of 15,517 individuals, 9,918 males and 5,599 females were included in the study. Asthma was diagnosed in 16% of males and 53% of females. Overall, 50% of males and 30% of females died during the follow-up period. The mortality rates in both males and females who visited emergency rooms for COPD or asthma were significantly higher than the expected rates in the general population. These relative increases in the mortality rates were significantly higher in females than in males for both causes of death, COPD (age-adjusted female/male ratio = 2.39), and asthma (ratio = 3.95). However, survival was better in females than males among individuals in the study. The higher fatality in males than females was observed for all causes of death, all respiratory causes, and COPD (risk ratio among patients with COPD = 0.42, 0.29-0.59, and among patients with asthma = 0.11, 0.02-0.60), but not for asthma. Mortality for asthma was higher in females with a diagnosis of COPD (2.79, 1.52-5.13), but it was not different among individuals in whom asthma was diagnosed (1.02, 0.56-1.87). Greater severity of COPD in males than in females could explain a higher risk of dying for all respiratory causes and COPD in males. The increased risk of asthma death in females may be due to problems of coding the term "asthma" in death certificates. The higher rates in females than in males when comparing with the general population, may be an expression of a greater similarity in risk factors, such as smoking, in our population than in males and females of the general population.

Adolescent↗
PubMed1997

Identification of a genetic locus for familial atrial fibrillation.

BACKGROUND: Atrial fibrillation, the most common sustained cardiac-rhythm disturbance, affects over 2 million Americans and accounts for one third of all strokes in patients over 65 years of age. The molecular basis for atrial fibrillation is unknown, and palliative therapy is used to control the ventricular rate and prevent systemic emboli. We identified a family of 26 members of whom 10 had atrial fibrillation which segregated as an autosomal dominant disease. We subsequently identified two additional families in which the disease was linked to the same locus. METHODS: We screened the human genome with 300 polymorphic dinucleotide-repeat markers using an unconventional strategy of pooling the DNA samples into two groups (affected and unaffected), which reduced the sample size by approximately 90 percent, before performing linkage analysis to map the locus. This made it possible to identify potential loci within a few weeks. RESULTS: The lod scores for markers D10S569 and D10S607, located at 10q22-q24, were 3.60 in Family 1. The disease locus in Families 2 and 3 was also linked to the same markers, with lod scores of 6.02 and 5.35 for markers D10S569 and D10S607, respectively, when data on all three families were combined. Haplotype analysis of the three families showed that the locus was between D10S1694 and D10S1786, an interval of 11.3 centimorgans. CONCLUSIONS: Identification of the gene for familial atrial fibrillation will help to elucidate the molecular basis of the disease and provide insights into acquired forms. The strategy of pooling DNA samples for analysis is more time and cost effective than conventional screening and should accelerate the process of gene mapping in the future.

Adult↗
PubMed1997

Expression of adhesion molecules in 113 patients with B-cell chronic lymphocytic leukemia: relationship with clinico-prognostic features.

The B-cell chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease, its clinical and biological behavior possibly being influenced by surface molecules expressed in B-lymphocytes. These molecules mediate cell adhesion, mobility and homing. Expression of surface adhesion molecules of the integrin family (CD11a/CD18 or LFA-1, CD11c/CD18), of the immunoglobulin-related family (CD54), of the selectin family (CD62L or LAM-1) and the lymphocyte homing receptor (CD44) were analyzed in peripheral cells from 113 B-CLL patients. The association with three prognosis-related parameters (Rai stage, bone marrow pattern and doubling time) was determined. The study included only patients with B-CLL lymphocytes of typical morphology, which always expressed CD5 and CD23. Low expression of integrins, particularly CD18, was associated with advanced disease (Rai stages III-IV) and diffuse bone marrow pattern, even after adjusting for other prognosis-related variables. Expression of CD54 was associated independently with rapid doubling time (less than 12 months). The association persisted after adjusting for stage and bone marrow pattern; CD44 was expressed in all patients. No correlations were found between expression of CD62L and the prognostic variables analyzed. In conclusion, CD54 expression and low CD18 expression are both significantly associated with poor prognostic features.

Adult↗
PubMed1997

Lymphocytes with cerebriform nuclei in chronic B-cell lymphoproliferative diseases.

Two patients with chronic lymphoproliferative diseases, a splenic marginal zone lymphoma and hairy cell leukaemia variant, were reported. In both diseases a B-immunophenotype was demonstrated but a variable percentage of lymphoid cells (30 and 52%) showed a highly irregular nuclear outline, sometimes mimicking the nuclei of Sézary cells.

Aged↗
PubMed1997

[Familial auricular fibrillation].

INTRODUCTION AND OBJECTIVE: We present two families with atrial fibrillation in 20 of 50 members, during three generations, with known cardiac rhythms, in order to communicate their infrequent existence and the most relevant clinical facts. METHOD: Clinical situation, evolution, ECG and ECHO findings, treatments and complications related with the disease are investigated. RESULTS: The presence of atrial fibrillation in 20 members is demonstrated, although one of them was on sinus rhythm at the time of the study; 3 patients had left ventricular enlargement on the ECHO study; the clinical situation was good in all patients except two who died because of complications related to the arrythmia and a third patient that had a brain stroke. The patients received different treatments because they where controlled by different physicians; the possible lethal proarrythmic effect in such cases must be taken into account. CONCLUSION: Familiar atrial fibrillation is a very infrequent arrythmia, usually well tolerated, that follows a dominant autosomic hereditary pattern. The use of antiagregants is advised because of the risk of embolism, or the use of anticoagulants in the presence of associated risk factors. Electric cardioversion has been show not be useful. The possible proarrythmic effect of some antiarrythmic agents, used in the control of cardiac frequency, must be taken into account.

Adolescent↗
PubMed1997

Local repolarization abnormalities induced by transcatheter radiofrequency ablation in pigs.

Radiofrequency (RF) ablation alters action potential repolarization of myocardial cells and, theoretically, this should induce ST-T segment changes in the ECG. Since these ECG abnormalities have been rarely reported in patients submitted to RF ablation we assess the ability of the procedure to cause ST-T segment changes in local electrograms. Epicardial ECG mapping was performed in 17 anesthetized open chest pigs submitted to endocardial (n = 9) or to epicardial (n = 8) unipolar radiofrequency ablation (500 kHz, 20 W for 5-10 s). To characterize the cellular electrophysiological alterations induced by RF ablation transmembrane action potentials were recorded at various distances from the ablation lesion; these were compared with seven control pigs. Endocardial RF ablation induced a transient (< 5 min) change of 6.1 +/- 2.4 mV in T wave amplitude (baseline: 12.8 +/- 5.6 mV, P < 0.001) in 141 out of 269 epicardial electrodes. T wave changes were associated with shortening in local activation time (20.1 +/- 2.3 ms at baseline vs 18.5 +/- 2.5 ms at 60 s after ablation, P = 0.03). RF current caused persistent St segment elevation at the center of the ablation lesion with no transmural expansion. Intracellular potentials along a 2-6 mm wide myocardial band bordering the RF lesion lower amplitude (101 +/- 7.0 mV vs 71 +/- 23 mV, P < 0.01) and shorter duration (254 +/- 44 ms vs 156 +/- 29 ms, P < 0.01) than control hearts. The center of the ablation lesion was electrically unexcitable. We concluded that RF ablation alters cellular electrophysiology in small areas surrounding the ablation lesion and this causes short-lasting transmural changes in T 3 wave amplitude and nontransmural ST segment elevation.

Action Potentials↗
PubMed1997

Effect of reduced gravity on the preferred walk-run transition speed.

We investigated the effect of reduced gravity on the human walk-run gait transition speed and interpreted the results using an inverted-pendulum mechanical model. We simulated reduced gravity using an apparatus that applied a nearly constant upward force at the center of mass, and the subjects walked and ran on a motorized treadmill. In the inverted pendulum model for walking, gravity provides the centripetal force needed to keep the pendulum in contact with the ground. The ratio of the centripetal and gravitational forces (mv2/L)/(mg) reduces to the dimensionless Froude number (v2/gL). Applying this model to a walking human, m is body mass, v is forward velocity, L is leg length and g is gravity. In normal gravity, humans and other bipeds with different leg lengths all choose to switch from a walk to a run at different absolute speeds but at approximately the same Froude number (0.5). We found that, at lower levels of gravity, the walk-run transition occurred at progressively slower absolute speeds but at approximately the same Froude number. This supports the hypothesis that the walk-run transition is triggered by the dynamics of an inverted-pendulum system.

Energy Metabolism↗
PubMed1996

Lipaemia and lipoproteinaemia in a Spanish male nonsmoker population consuming sunflower oil.

The aim of this study was to assess the prevalence of altered levels of serum lipids, lipoproteins and apolipoprotein (Apo) B in very active, 20 to 65 year-old, Spanish male nonsmokers who consumed sunflower oil. Among the 169 participants, total serum cholesterol (TC), triglycerides (TG), LDL-C, and TC/HDL-C were found to be age-dependent variables. A detailed study over a 12-day period showed that this population displayed a Mediterranean dietary pattern, with the exception of the substitution of sunflower for olive oil Saturated, monounsaturated and polyunsaturated fatty acids represented 9.9%, 12.7% and 8.8% of the total amount of energy, respectively. The cholesterol-saturated fat index of the average diet was 19.2 per 1000 kcal, whereas the Keys index of the diet was 27.1. Daily intakes of fibre, ascorbic acid and vitamin E were 25.1 g, 89.6 mg and 28.3 mg, respectively. The calcium/magnesium ratio of the average diet was 1.54. The low percentage of individuals with high TC levels (5.4% with TC > or = 6.49 mmol/L), high TG levels (3.7% with TG > or = 2.25 mmol/L), high Apo B levels (3.0% with > or = 1.5 g/L), low levels of HDL-C (0.7% with < or = 0.91 mmol/L), high LDL-C levels (1.4% with > or = 4.94 mmol/L or a high TC/HDL-C ratio (2.8% with > or = 5.0) suggest a reasonable protection against coronary heart disease in this Spanish population.

Adult↗
PubMed1996

Coronary denervation attenuates coronary constriction induced by muscarinic receptor stimulation in pigs.

OBJECTIVES: We tested the hypothesis that coronary denervation attenuates the reactivity of the coronary vessel to cholinergic stimulation. METHODS: Heart rate, left ventricular (LV) pressure, LV dP/dt, coronary blood flow at the left anterior descending (LAD) coronary artery, and epicardial ECG mapping were measured before and after topical application of 1% methacholine to the LAD in 10 pigs anesthetized with alpha-chloralose (100 mg/kg, i.v.); these were compared with 10 other pigs submitted 2 weeks previously to a denervation of the LAD with phenol. Coronary denervation was confirmed in all cases by adrenergic histofluorescence and by acetyl-cholinesterase staining. Isolated LAD rings from 10 additional pigs (5 controls and 5 treated with phenol) were stimulated with endothelin-1 to verify whether phenol affected coronary reactivity to noncholinergic stimulation. RESULTS: Methacholine induced a fall in coronary blood flow (10.3 +/- 5.3 ml/min vs 4.8 +/- 6.2 ml/min, ANOVA: P < 0.001), a drop in systolic LV pressure (113 +/- 19 mmHg vs 93 +/- 19 mmHg, P < 0.001) and LV dP/dt (1608 +/- 363 mmHg/s vs 1203 +/- 302 mmHg/s, P = 0.02) and elevation of the ST segment (1.4 +/- 0.9 vs 11.1 +/- 4.7 mV, P < 0.001) in controls. These changes were not preceded by heart rate variations and were inhibited by atropine. As compared to controls, phenol-treated pigs showed a smaller decline in coronary blood flow (13.1 +/- 4.5 ml/min to 10.4 +/- 5.4 ml/min, P < 0.001), a lower drop in LV pressure (107 +/- 20 mmHg to 100 +/- 19.7 mmHg, P < 0.001) and lesser ST segment elevation (2.2 +/- 1.7 mV to 5.6 +/- 4.2 mV, P < 0.001). Isolated LAD rings contracted after exposure to endothelin-1 in both controls and phenol-treated pigs (3.5 +/- 0.7 g vs 2.4 +/- 1.0 g, P = 0.06). CONCLUSIONS: Coronary denervation attenuates coronary constriction induced selectively by direct muscarinic receptor stimulation in the in situ pig heart.

Animals↗
PubMed1996

Feasibility and results of bone marrow transplantation after remission induction and intensification chemotherapy in de novo acute myeloid leukemia. Catalan Group for Bone Marrow Transplantation.

PURPOSE: To evaluate prospectively the feasibility and results of bone marrow transplantation (BMT) after induction and intensification chemotherapy (CT) in patients with de novo acute myeloid leukemia (AML). PATIENTS AND METHODS: A total of 159 patients less than 51 years of age were treated. Induction CT consisted of daunorubicin 60 mg/m2 for 3 days, cytarabine (ARA-C) 100mg/m2 for 7 days, and etoposide 100 mg/m2 for 3 days. The first intensification therapy included mitoxantrone 10 mg/m2 for 3 days and ARA-C 1.2 g/m2 every 12 hours for 4 days. Amsacrine (100 or 150 mg/m2 for 3 days) and ARA-C (1.2 g/m2 every 12 hours for 2 or 4 days) were given as the second intensification therapy. Depending on the availability of a human leukocyte antigen (HLA)-identical sibling, the intention of treatment after CT was allogeneic BMT (allo-BMT) or autologous BMT (ABMT). RESULTS: Complete remission (CR) was obtained in 120 patients (75%) and partial remission (PR) in 11 (7%), while 15 patients (10%) were refractory and 13 (8%) died during induction. There was a trend for better leukemia-free survival (LFS) at 4 years for patients assigned to the ABMT group (50% +/- 6%) compared with the allo-BMT group (31% +/- 7%) (P = .08). This difference in LFS reached statistical significance when considering only transplanted patients (63% +/- 3% at 4 years after ABMT and 38% +/- 11% after allo-BMT, P = .02). The favorable results in patients who received ABMT (no toxic deaths and 37% +/- 7% probability of relapse at 4 years) contrast with the poor outcome of allografted patients (11 patients with transplant-related mortality). CONCLUSION: Our study reflects the difficulties in the completion of a therapeutic strategy that include BMT and suggests that intensification before BMT may be useful in the setting of ABMT, but this approach was associated with a high mortality rate in allo-BMT patients.

Acute Disease↗
PubMed1996

Incidence and characteristics of lymphoid malignancies in untreated myelodysplastic syndromes.

We have analyzed 1,198 patients with untreated myelodysplastic syndromes (MDS) with two main objectives: (1) to determine the prevalence of lymphoid malignancies (LM) in MDS patients; and (2) to ascertain whether there is some relationship between the MDS subtype and the LM type. In fourteen of 1,198 primary MDS patients (1%) (4 with refractory anemia, 3 with refractory anemia with ring sideroblasts, 2 with refractory anemia with excess of blasts and 5 with chronic myelomonocytic leukemia) a LM was detected. In all cases, the LM was of the B-cell type: 6 cases of chronic lymphocytic leukemia, 5 cases of lymphoplasmacytoid lymphoma, and 3 cases of multiple myeloma. B-cell malignancy did not prevail in any MDS subtype and no correlation was observed between the different varieties of both diseases. In conclusion, in this large series, 1% of the untreated patients with MDS had B-cell malignancy, an association that in most cases is likely to be merely coincidental.

Aged↗
PubMed1996

[Standardization Committee for Haematology. External Quality Assurance Program for General Hematology. Evaluation of the 1994 results].

UNLABELLED: Since 1994, the Standardisation Committee for Haematology publishes yearly the results of its external quality assurance programme (EQAPH), after it has been improved and even integrated in the Health Services of some autonomous communities. METHODS: Four hundred and seventy-three laboratories take part in EQAPH. The evaluation of the haematological records is carried out every year from the results of two whole blood samples. Two samples of lyophillised plasma are sent every month to participant laboratories in order to assess prothrombin time (PT), partial thromboplastin time (PTT) and fibrinogen. Samples are sent every three months for antithrombin III (AT-III) determination. According to the types of autoanalysers used, 9 groups have been established: Group I (Technicon H* and H-6000), group II (Technicon H*2 and H*3), group III (Coulter MaxM, STKS, Cobas Argos and Cell-Dyn 3000/3500), group IV (Coulter STKR), group V (Coulter JS/JT), group VI (Coulter S/T, Cobas Helios/Minos), group VII (Sysmex E/NE), group VIII (Sysmex K-1000), and group IX (other semi-automated counters). Three groups are established for general coagulation tests and two others for AT-III. The value of the mean of all results (consensus mean) and of each particular group (group mean) are used as statistical methods. The results are expressed as: (1) coefficient of variation, % (CV); (2) deviation index (DI); DI values attained with respect to the same group (or method) or all groups (or methods) allowed us to classify the results in four categories: excellent (0 < DI < 0.5), good (0.5 < DI < 1.0), satisfactory (1.0 < DI < 2.0), and out of acceptable limits (ID > 2.0); (3) Youden graphs or graphic representations of DI calculated from the analysis of the control specimens. RESULTS: Group I yielded lesser values for leucocyte count (0.221) and higher for MCH (0.833). Group II showed high DI values for PCV (0.933) and MCV (1.146). Group III had lower values for red cell count (0.097), haemoglobin concentration (0.133) and MCH (0.91). Group IV showed lower platelet count. Group V had higher haemoglobin concentration values. Group VI yielded higher DI in the platelet count and group VII in the white cell count. Group VII showed the lowest DI for MCV and MHC. Group IX had high values for red cell count and MCH. In the coagulation field, group I had higher values for PT and AT-III. Group II showed higher DI values for PTT and fibrinogen. The highest CV values were seen in groups VIII and IX. The lowest values were present in group II for haemoglobin, IV for MCH, in V for PCV and MCV, in VII for red cell count and MCH, in VII for white cell count and in VII for platelet count. The coagulation tests showed lower CV values than cytometry, the lowest being for PT in group I and PTT and fibrinogenein group II. With regard to the influence of acceptable results on adverse ones within this group, the percentage of laboratories with mean DI over 2 were calculated. Thus, the laboratories achieved 43.5% of values within acceptable limits for platelet count and 56.7% for white cell count. Regarding the PCV, out of 47.9% of the laboratories, only 1.0% showed high deviation of some results. In the coagulation parameters, of the 37.2 in this group for AT-III, 32.4% showed a mean DI over 2. CONCLUSIONS: Participation in External Quality Assurance programmes contributes to the comparability of the results provided by different laboratories, thus increasing their accuracy and improving the quality of patient care.

Blood Cell Count↗