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Biomedical subjects

J García

Publications and source records attributed to J García.

At least 145 records · Page 8Linked to original sources
PubMed1998

Comparative study of local and Karhunen-Loève-based ST-T indexes in recordings from human subjects with induced myocardial ischemia.

In this work we studied ST-T complex changes in the ECG as result of induced ischemia. The principal aim was to determine whether global changes in the ST-T complex were more sensitive markers of ischemic alterations than those based on measurements of changes at specific locations on ST segment or T wave. High-resolution ECGs from patients undergoing percutaneous transluminal coronary angioplasty in one of the major coronary arteries were analyzed to give a description of the period from the end of active depolarization (QRS complex) to the end of active repolarization (T wave). During artery occlusion traditional local measurements of the ST-T complex were compared to global measurements based on the Karhunen-Loève transform. An ischemic change sensor parameter was estimated for each of the studied indexes showing that global measurements detected changes better in the repolarization period in a larger number of leads and with higher sensitivity (more than 85%) than was done using local measurements (sensitivity of 64% with ST level, 33% with T-wave maximum position, and 37% with T-wave maximum amplitude). Using these global indexes it was found that most cases of ST-segment changes were accompanied by T-wave changes (72% of patients). With the use of traditional indexes 23% of patients showed no changes in the repolarization period, whereas with global indexes this percentage decreased to 8%. Thus a global representation of the entire ST-T complex appears to be more suitable than local measurements when studying the initial stages of myocardial ischemia.

Algorithms↗
PubMed1998

[Initial results with the Multi-Link coronary stent].

INTRODUCTION AND OBJECTIVES: The Multi-Link intracoronary stent is a balloon-expandable stainless steel stent with an interconnected ring structure designed to provide a high degree of compressive resistance while preserving longitudinal flexibility. We present the results of our initial experience with the implantation of this stent. PATIENTS AND METHODS: From May 1996 to April 1997, 124 Multi-link stents were implanted in 97 patients. Mean age 62.2 +/- 11 years. All patients included had a coronary artery diameter > 2.7 mm. Clinical presentation includes stable angina in 20, unstable angina in 72, and myocardial infarction in 5 patients. According to the ACC/AHA classification 6 lesions were type A, 72 type B and 19 type C. The implantation of the stent was for "de novo" lesions in 85 patients and for restenosis in 12. Patients were treated after the procedure with a combination of aspirin and ticlopidine, except six of them who received aspirin and acenocumarol. 16 patients were treated additionally with Abciximab. The degree of stenosis was determined by quantitative angiography. RESULTS: The delivery of the stent was successful in all patients. The degree of stenosis before the procedure was 79.6 +/- 13.1%, and after the stent deployment was 17.7 +/- 11.4%. Three patients presented a non-Q-wave myocardial infarction, two patients had a subacute stent thrombosis, one of them died due to heart failure. During a follow-up of 4.7 +/- 2.6 months five patients were readmitted with recurrent angina (4 due to restenosis and one for vessel occlusion) and one patient with heart failure after myocardial infarction died suddenly three weeks after the dilatation. CONCLUSIONS: The Multi-Link stent was implanted successfully in all patients with a low incidence of complications, showing at the follow-up a reduced rate of clinical restenosis.

Coronary Disease↗
PubMed1998

Clinical results of AcrySof intraocular lens implantation.

PURPOSE: To analyze the clinical results of AcrySof intraocular lens (IOL) implantation. SETTING: San Juan University Hospital, Alicante, Spain. METHODS: This retrospective study comprised 100 patients with cataract 81 without previous eye pathology and 19 with previous eye pathology (i.e., diabetes, traumatic cataract, central corneal leukoma, glaucoma). Phacoemulsification technique depended on the type of cataract. Mean follow-up was 9 months. RESULTS: Best corrected visual acuity was 20/40 or better in 11.52% of patients with preoperative eye pathology and in 100% of those without pathology. CONCLUSION: Implantation of AcrySof IOLs did not result in complications or adverse reactions in our series, indicating that its use is safe in small incision cataract surgery.

Acrylates↗
PubMed1998

Allogeneic transplantation of selected CD34+ cells from peripheral blood: experience of 62 cases using immunoadsorption or immunomagnetic technique. Spanish Group of Allo-PBT.

The objective of this study was to analyze CD34+ cell recovery and T cell depletion (TCD) achieved in CD34+ cell grafts using either immunoadsorption or immunomagnetic methods applied to leukapheresis products from healthy donors. We also wanted to determine the kinetics of engraftment and incidence and severity of graft-versus-host disease (GVHD) after allogeneic transplantation of selected CD34+ cells. HLA-identical sibling donors received G-CSF. After leukapheresis, peripheral blood progenitor cells were selected using immunoadsorption (Ceprate SC) (n = 38) or immunomagnetic (Isolex 300) (n = 24) methods. Sixty-two patients, with a median age of 42 years (range 17-60) diagnosed with hematological malignancies were conditioned with either cyclophosphamide and total body irradiation (n = 43) or busulphan and cyclophosphamide (n = 19). GVHD prophylaxis consisted of cyclosporin A (CsA) and prednisone (n = 48), CsA alone (n = 11) and CsA and methotrexate (n = 3). The median yield and purity of CD34+ cells after the procedure was 65 and 66% with immunoadsorption, and 48 and 86% with immunomagnetic method, respectively. The median number (range) of CD34+ cells infused into the patients was 3.5 x 10(6)/kg (1-9.6). The median number (range) of CD3+ cells administered was 0.4 x 10(6)/kg (0.01-2) using immunoadsorption and 0.14 x 10(6)/kg (0.03-2.5) using immunomagnetic methods. Neutrophil recovery >500 and >1000/microl was achieved at a median (range) of 13 days (8-22) and 14 days (9-31), respectively. Platelets recovered to >20000 and >50000/microl at a median (range) of 13 days (0-128) and 18 days (0-180), respectively. Two patients developed graft failure. Acute GVHD in patients at risk was clinical grade 0 (n = 43), I (n = 8), II (n = 4) and III (n = 1). No patient developed acute GVHD grade IV. Chronic GVHD was limited in two cases and extensive in four cases. The actuarial probability of acute GVHD II-IV was 10% (95% CI, 1-19%), and of extensive chronic GVHD was 12% (95% CI, 11-13%). The cumulative incidence of transplant-related mortality was 12.6%, and this figure was 9% at 6 months. In conclusion, with the immunomagnetic procedure, a lower recovery and higher purity of CD34+ cells, and stronger TCD is obtained as compared to immunoadsorption (P = 0.008, P < 0.0001 and P = 0.0002, respectively). Our results also indicate that allogeneic transplantation of selected CD34+ cells is associated with a very rapid engraftment and with a low incidence of severe GVHD.

Acute Disease↗
PubMed1998

Haemorrhagic septicaemia by Aeromonas salmonicida subsp. salmonicida in a black-tip reef shark (Carcharhinus melanopterus).

One black-tip reef shark (Carcharhinus melanopterus) was found dead without previous signs of disease. Major lesions consisted in cutaneous erythema, mainly at the base of the fins, focal to diffuse inflammatory lesions in gills and intestinal wall, and discrete haemorrhages in the same organs, liver and kidneys. Microcolonies of Gram-negative rods were observed in the lamina propia of gills, underneath the intestinal mucosa and randomly distributed in the renal and hepatic parenchymas. Also, emboli containing Gram-negative rods were observed in capillaries of these organs. Aeromonas salmonicida subsp. salmonicida was isolated in pure culture from gills, liver and intestine. Specific immunostaining confirmed the relationship between the isolate and lesion-associated bacteria. No previous reports on this infection in sharks have been found in the literature.

Aeromonas↗
PubMed1998

[Coronary stent placement for recurrent angina secondary to myocardial bridging].

Myocardial bridging of the epicardic coronary arteries is not an uncommon finding in angiographic or necropsic studies. Patients who have symptoms usually improve with medical treatment. However, in refractory patients a surgical myotomy of overlying myocardium and/or a coronary bypass may be needed. We report two patients with long myocardial bridges in the mid-left anterior descending coronary artery, who had recurrent angina refractory to conventional treatment. In both patients two consecutive coronary stents were successfully implanted. At five and six months follow-up they are asymptomatic and with good exercise tolerance.

Aged↗
PubMed1998

Androgens for the treatment of anemia in peritoneal dialysis patients.

Before the advent of recombinant human erythropoietin (EPO), androgens were used for treatment of anemia in dialysis patients. However, after the availability of recombinant EPO in the 1980s, the use of these substances was abondoned. We have previously reported that androgens have beneficial actions on anemia in selected hemodialysis patients. In the present study we have analyzed the effects of androgen administration on hematologic parameters in peritoneal dialysis patients. We evaluated 9 patients treated for 6 months with nandrolone decanoate (200 mg/week intramuscularly). Hemoglobin and hematocrit values experienced a significant increment with respect to basal values during the study (9.2 +/- 0.7 g/dL and 27.7% +/- 2.3% at basal vs. 11.9 +/- 0.5 g/dL and 35.3% +/- 1.6% at month 6, respectively; P < 0.001). In addition to the effects on the hematologic parameters, androgen administration also had beneficial anabolic actions with a significant increment in the serum concentration of total proteins and albumin (basal, 6.1 +/- 0.3 g/dL and 3.1 +/- 0.4 g/dL vs. 6.7 +/- 0.4 g/dL and 3.8 +/- 0.4 g/dL at month 6, respectively, P < 0.01). The only adverse effect was a rise in the serum concentration of triglycerides (176 +/- 54 mg/dL vs. 144 +/- 53 mg/dL, P < 0.01). In conclusion, androgen administration has beneficial effects on erythropoiesis as well as positive anabolic actions in patients under peritoneal dialysis.

Aged↗
PubMed1998

Collection of peripheral blood progenitor cells for autografting with low-dose cyclophosphamide plus granulocyte colony-stimulating factor.

BACKGROUND AND OBJECTIVE: The combination of high or intermediate-dose cyclophosphamide (CY) plus granulocyte colony-stimulating factor (G-CSF) is useful to mobilize hematopoietic progenitor cells to peripheral blood, but the patients require hospitalization. The aim of this study was to evaluate the efficiency of low-dose CY plus G-CSF (5 ug/kg/day s.c.) as an outpatient treatment in order to collect enough progenitor cells for hematopoietic rescue in autologous peripheral blood transplantation (APBSCT). DESIGN AND METHODS: We analyzed twenty-eight consecutively treated patients with lymphoma or multiple myeloma. The number of CD34+ cells in blood samples was determined from day +7. Leukapheresis (LKP) began when the absolute number of CD34+ cells in peripheral blood was > 2500/mL and the apheresis product was assayed for mononuclear cells (MNC), granulocyte-macrophage colony-forming units (CFU-GM), total nucleated cells (tNC) and CD34+ cells. RESULTS: Twenty-eight outpatients with advanced hematologic malignancies (13 non-Hodgkin lymphoma, NHL; 10 Hodgkin's disease, HD; and 5 multiple myeloma, MM), median age 44 years (range 23-65) received a single dose of CY (1.5 g/m2 i.v. day 0) followed by G-CSF (5 ug/kg/day s.c.) from day +1 to the end of LKP. Considering patients who had successful mobilization (64%), a median of 7.1 x 10(6)/kg CD34+ cells (range 3.5-11.9), 5.7 x 10(5)/kg CFU-GM (range 1.5-9.2), 4.4 x 10(8)/kg MNC (range 1.9-7.9) were collected. Treatment was well tolerated and none of these patients was hospitalized due to neutropenic fever. Only one patient received two packed red blood cells following chemotherapy. Autologous peripheral blood stem cell transplantation (APBSCT) has been performed in 18 patients (64%). The mean number of days to achieve > 0.5 x 10(9) PMN/L and > 20 x 10(9) PLT/L was 12 (10-17) and 12.6 (8-24), respectively. INTERPRETATION AND CONCLUSIONS: Considering a pre-established threshold of 2.5 x 10(6)/kg CD34+ cells to proceed to APBSCT, the mobilization therapy was successful in 64% of the patients but was unsuccessful in 10 patients (5 NHL, 4 HD and 1 MM). Hematopoietic recovery was complete and stable in all patients. Low-dose CY plus G-CSF is efficient to collect enough PBSC for hematopoietic rescue after myeloablative therapy in patients with lymphoprolipherative disorders or multiple myeloma.

Adult↗
PubMed1998

Effects of losartan on the treatment of posttransplant erythrocytosis.

Erythrocytosis is a relatively common complication of renal transplantation. Recent observations indicate that angiotensin-converting enzyme inhibitors correct renal transplant erythrocytosis. Other drugs to inhibit the renin-angiotensin system have been developed recently. The newest of these is losartan, a specific antagonist of the angiotensin II type I receptor. We report three patients in which the use of losartan controlled posttransplant erythrocytosis. Our findings suggest that losartan can be effective and safe in the treatment of posttransplant erythrocytosis.

Adult↗
PubMed1998

Allogeneic transplantation of purified CD34+ cells from peripheral blood: Spanish experience of 62 cases. Spanish Group of allo-PBT.

This report summarizes the Spanish experience of 62 cases of allogeneic transplantation of purified CD34+ cells from peripheral blood. HLA-identical sibling donors received G-CSF. After leukapheresis, peripheral blood progenitor cells were purified using one of two methods: Ceprate (n = 38), or Isolex 300 (n = 24). Sixty-two patients median age 42 years (range 17-60) diagnosed with hematological malignancies were conditioned with either cyclophosphamide and total body irradiation (n = 43) or busulphan and cyclophosphamide (n = 19). GVHD prophylaxis consisted of cyclosporin A (CsA) and prednisone (n = 48), CsA alone (n = 11), and CsA and methotrexate (n = 3). The median yield and purity of CD34+ cells after the procedure was 65% and 66% with Ceprate, and 48% and 86% with Isolex, respectively. The median number of CD34+ cells infused into the patients was 3.5 x 10(6)/kg (range 1-9.6). The median number of CD3+ cells administered was 0.4 x 10(6)/kg (range 0.01-2) using Ceprate and 0.14 x 10(6)/kg (range 0.03-2.5) using Isolex. Neutrophil recovery >500 and >1000/microl was achieved at a median of 13 days (range 8-22) and 14 days (range 9-31), respectively. Platelets recovered to >20,000 and >50,000/microl at a median of 13 days (range 0-128) and 18 days (range 0-180), respectively. The actuarial probability of acute GVHD II-IV was 10% (95% CI, 1-19%), and of extensive chronic GVHD 12% (95% CI, 11-13%).

Adolescent↗
PubMed1998

Expansion of cord blood progenitor cells.

Cord blood (CB) provides an alternative source of stem cells for transplantation, although in a considerable number of cases CB transplantation is followed by long periods of aplasia. Ex vivo expansion has the capacity to generate large amounts of progenitors, and it has been proposed that expanded cells might be beneficial in overcoming these long periods of aplasia. We describe the biological characteristics of cord blood compared to other sources of stem cells (BM and PB), and report the effects of FLT3-L and MIP-1alpha when added to a combination of SCF, IL-3 and IL-6 in pre-clinical short-term, serum-free expansion cultures of CB-derived CD34+ cells. After 6 days, this culture system was able to generate considerable expansion rates in the committed compartment (between 8.16- and 17.26-fold for CFU-GM, and 21.58- and 36.53-fold for the BFU-E/CFU-Mix), and the CD34+ population (between 11.25- and 25.42-fold). Moreover, this culture system was also able to maintain the week 5 CAFC population, particularly when both FLT3-L and MIP-1alpha were present (91% of the input level). Thus, we have described a pre-clinical protocol for ex vivo expansion of CB CD34+ cells in a short-term, static, serum-free system, where a high generation of committed progenitor cells is achieved together with CAFC maintenance.

Cell Culture Techniques↗
PubMed1998

[Caudal regression syndrome].

INTRODUCTION: The regression caudal syndrome includes a spectrum of malformations which vary from the symptomless coccygeal agenesis until thoracic vertebrae and sacrococcygeal agenesis with severe neurological deficit; it is associated sometimes with malformations in other organs and systems. We present a case of partial agenesis of sacro and coccix with neuromuscular, sphincter and orthopedist alterations. CLINICAL CASE: A 4-year-old patient consults because of walk alterations, with daytime and nocturnal enuresis and urinary incontinence, constipation/encopresis and rectal prolapse. Familiar and personnel precedents are uninteresting. She began to walk at normal age, referring only rectal prolapse with constipation from nursing and urinary tract infections and encopresis when she was 3 years old, with normal complementary explorations (digestive and nephrourologyc). She presents in lumbosacral X-rays four lumbar vertebrae, a dysplasic sacro and absence of coccix. Hypoplasy of sacro with bilateral stenosis of the pelvis and coxa vara in both femurs are seen in the lumbar CT. In RMI is observed agenesis of sacro and coccix vertebrae. CONCLUSIONS: There are a wide variety of sacrococcygeal agenesis, which are classified by Renshaw and modified by Pang. As etiologics factors we find the gestational diabetes, in addition to genetic factors. The clinic exploration guides us toward a flaccid paraparesia/areflexia, with orthopaedist alterations, sometimes of artrogripotyc type. With image techniques (X-rays, CT, MRI) we can accomplish the diagnosis and we can discard or demonstrate associated medullary anomalies. We concluded that in all patient with alterations of walk and/or lack of sphincters control we should explore the lumbosacral region searching for medulodiysplasic or vertebral alterations.

Abnormalities, Multiple↗
PubMed1997

High-titer retroviral vectors containing the enhanced green fluorescent protein gene for efficient expression in hematopoietic cells.

Retroviral vectors constitute the most efficient system to deliver and integrate foreign genes into mammalian cells. We have developed a producer cell line that yields high titers of amphotropic retroviral vectors carrying the enhanced green fluorescent protein (EGFP) gene, a codon humanized, red-shifted variant of the green fluorescent protein (GFP) gene, which can be used as a selectable marker. We have used a hybrid vector that has been shown to efficiently drive gene expression in hematopoietic cells. Virtually all murine and human cell lines and primary human hematopoietic cells tested were transduced with varying efficiency after incubation with vector-containing supernatants. Human CD34(+) cells obtained from cord blood or aphereses products were transduced using a protocol that involves daily addition of vector-containing supernatants for 6 consecutive days. At day 6, up to 16% of the cells expressed EGFP, as assessed by flow cytometry. Sorted EGFP-expressing cells were able to produce fluorescent hematopoietic colonies. EGFP's main advantages are its fast flow cytometry determination and the possibility of cell sorting and simultaneous evaluation of the transduction efficiency along with other phenotypic markers.

3T3 Cells↗
PubMed1997

Molecular characterization of the Entamoeba histolytica enolase gene and modelling of the predicted protein.

Entamoeba histolytica obtains its energy mainly from glucose fermentation. Enzymes involved in this pathway could be potential targets for antiparasite drugs. Here we report the molecular characterization of the E. histolytica enolase gene (Ehenl-I), which in a single copy is located on the 1.6 Mb chromosome. It is transcribed into a 1.4 kb mRNA which starts 13 nucleotides upstream of the ATG start codon. The sequence TATAAG, at -31, interacted with nuclear proteins suggesting that it has a TATA box function. Protein modelling allowed us to identify a putative specific region that differs from human enolase and could be a good target for the design of novel drugs against E. histolytica.

Amino Acid Sequence↗
PubMed1997

Patterns of uveitis as a guide in making rheumatologic and immunologic diagnoses.

OBJECTIVE: To describe the patterns of clinical presentation in a series of 407 patients with uveitis and to establish the relationship between these patterns and the final diagnosis. METHODS: Patients were referred to the Uveitis Clinic of a tertiary hospital from January 1992 to January 1996. All patients received a complete ophthalmologic examination, and a general clinical history was obtained. The current International Uveitis Study Group classification system was used for anatomic classification. To establish the final diagnosis of the most common entities causing uveitis, current diagnostic criteria were used. A discriminant analysis, with diagnostic grouping as the outcome variable and the clinical presentation features as discriminating variables, was performed. RESULTS: With our classification system, 66.5% of the cases could be correctly classified according to the clinical pattern and morphologic findings. By diagnostic groups, discriminant analysis showed that 75% of patients with Behçet's disease, 77.1% of those with spondylarthropathy (including inflammatory bowel disease), 33.3% of those with sarcoidosis, 97.9% of those with toxoplasmosis, 85.7% of those with Vogt-Koyanagi-Harada syndrome, 100% of those with herpes, and 50.4% of those with idiopathic uveitis were correctly classified. In the miscellaneous group, which included disease entities with fewer than 5 cases, 42.9% were correctly classified. CONCLUSION: Rheumatologic evaluation of the patient with uveitis can be more cost-effective if the referring ophthalmologist follows the classification system described herein, allowing a tailored approach in which only specific and necessary diagnostic tests are used.

Adolescent↗
PubMed1997

Role of S4 segments and the leucine heptad motif in the activation of an L-type calcium channel.

Basic residues in the S4 segments of voltage-dependent channels and leucines within the heptad repeat motif in the S4-S5 region of Shaker potassium channels have been shown to have important influences on activation. Here we have compared the relative importance for activation of S4 arginines (mutated to neutral or negative residues) in each of the four repeats of a chimeric L-type calcium channel. Significant effects on midpoint potential and time constant of activation were produced by mutations in repeats I and III but not in repeats II and IV. Leucine or isoleucine mutations in repeats I and III had the same effect on the voltage dependence of calcium channel activation as the mutations at equivalent positions in the Shaker channel, indicating that the heptad motif plays a fundamental role in channel activation.

Amino Acid Sequence↗