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J Corral

Publications and source records attributed to J Corral.

102 records · Page 6Linked to original sources
PubMedDate not supplied

In vitro analysis of platelet concentrates stored in the presence of modulators of 3',5' adenosine monophosphate, and organic anions.

The storage of conventional platelet concentrates (PCs) under standard blood bank conditions is limited to five days, in part because longer storage periods lead to increasing damage in platelet integrity and functionality. The growing demand of PCs for clinical use, raises the interest to develop agents that would potentially permit a more extended period of storage. We have evaluated and compared the in vitro quality of PCs treated with: (1) Modulators of levels of cAMP (PGE1, foskolin, theophylline and isobutyl-methyl-xanthine [IBMX]); and (2) organic anions that function as alternative substrates of platelets (pyruvate and acetate). Platelet rich plasma (PRP) from pools (n = 6) of PCs was distributed into storage bags, and the agents to be tested were added, using saline as a control substance. PCs were stored at 22 degrees C with continuous agitation for up to 10 days. At 0, 5 and 10 days of storage, samples were analyzed for platelet counts, mean platelet volume (MPV), metabolic markers, and expression of glycoproteins (GPs). The addition of modulators of levels of cAMP, at the concentration used in the study, did not lead to substantial improvement in the parameters being evaluated, with respect to those in control units. The supplementation with organic anions, while not affecting the surface levels of GPs, favored the maintenance of metabolic values, such as pH, PCO2, and bicarbonate concentrations, as well as the preservation of MPV (p values < 0.05 respect to control units both at 5 and 10 days of storage). Our results indicate that while the use of modulators of levels of cAMP do not provide substantial benefit in the prevention of platelet storage lesions, organic anions have some advantageous effect in the storage promoted metabolic changes of PCs. These data might be considered when designing strategies to improve PC storage.

1-Methyl-3-isobutylxanthine↗
PubMedDate not supplied

Prothrombotic genetic risk factors in patients with coexisting migraine and ischemic cerebrovascular disease.

The role of hemostatic elements in stroke has been clearly defined but several prothrombotic polymorphisms of hemostatic factors, important for other thromboembolic disorders, seem not to be very significant in stroke. Recently, the high prevalence of factor V Leiden in patients with stroke and a history of migraine has suggested an association between migraine and prothrombotic genetic risk factors. Stroke being a multifactorial disease, the aim of this study was to test whether prothrombotic tendencies increase the risk of stroke in patients with migraine. We determined the prevalence of four prothrombotic genetic risk factors (factor V R/Q 506, factor II 20210 G/A, decanucleotide insertion/deletion in the factor VII promoter, and the platelet HPA-1 alloantigen system) in 17 patients with coexisting ischemic cerebrovascular disease and migraine, 107 patients with ischemic cerebrovascular disease, 106 patients with migraine, and 202 control subjects. Genotyping for all polymorphisms analyzed in our study were performed after specific genomic polymerase chain reaction, and confirmed by single-strain conformation polymorphism analysis. In the group of patients with coexisting ischemic cerebrovascular disease and migraine, the prevalence of prothrombotic genotypes (factor V Leiden, 5.8%; factor II 20210 A, 0%; factor VII A1, 70.6%; and HPA-1b, 35.3%) was similar to that obtained in all other groups. We can conclude that the studied polymorphisms do not seem to be associated with the development of ischemic cerebrovascular disease in those patients with migraine.

Adult↗
PubMedDate not supplied

Factor-V (Arg506 --> Gln) mutation in ischemic cerebrovascular disease.

Factor V Leiden is already well established to be involved in venous thrombosis but not in coronary heart disease. Results are conflicting and even antagonistic in cerebrovascular disease (CVD). In this study we examine the prevalence of factor V Leiden in 125 consecutive patients with ischemic CVD 12 additional selected CVD patients with the first CVD episode before the age of 45 years, and 102 controls from the same area. Identification of the mutation was achieved using two molecular methods. The prevalence of factor V Leiden in patients with CVD was similar to that in the normal population. The presence of the mutation was independent of the age and severity of the ischemic episode. Finally, no significant clinical differences were found between patients with and those without factor V Leiden. Therefore, factor V Leiden cannot be considered as a genetic risk factor for CVD.

Adult↗
PubMedDate not supplied

Genetic determinants of platelet function in thromboembolic diseases.

Within the past decade our understanding of thromboembolic disorders has become even more sophisticated as recent discoveries have suggested the influence of gene variants on the development of atherosclerotic disease and arterial thrombosis. Candidate genes encode proteins involved in processes relevant to atherosclerosis, ranging from cholesterol metabolism to arterial thrombosis. Platelets are key elements in primary hemostasis, but also in arterial thrombosis. Moreover, a number of genetic polymorphisms of platelet proteins may also induce gain or loss of function, supporting a role predisposing some individuals to thrombotic events. However, after thousands of studies, much controversy remains whether individual platelet polymorphisms contribute to an increased likelihood of thromboembolic disorders. Although platelet polymorphisms are a promising addition to more established cardiovascular risk factors, identifying genetic variants as a single cause of cardiovascular disease would be an oversimplification; instead, the contribution of these polymorphisms should also be considered in the context of a multifactorial disease. Gene-gene and gene-environment studies would identify specific combinations associated with a high risk to suffer from these diseases. The platelet's genetic heterogeneity should also be considered in every aspect of clinical medicine, ranging from susceptibility to diseases, pathogenesis, and clinical outcome to diversity in responses to drug treatment (pharmacogenomics), and bleeding.

Annexin A5↗
PubMedDate not supplied

[Immune response to influenza vaccination].

The present study investigated the level of immunity of the population against three strains of the influenza virus (A Chile/1/83 -A Philippines/2/82 and B URSS/100/83) before and three months after vaccination, and the immune response to whole virus vaccine as compared with fragmented virus vaccine. A high percentage of the population had titers greater than or equal to 1/10 before vaccination for the Chile (54%) and Philippines (65.7%) strains, while titers against the URSS strain were lower (25.4%). There was a definitive increase in antibody titer in the vaccinated population, although it was lower than expected. The overall response to both vaccines, with protecting titers greater than or equal to 1/40 after vaccination was 65.2% for the Chile strain, 74.6% for the Philippines strain, and 15% for the URSS strain. No differences in the overall immune response were found between the groups vaccinated with whole and fragmented virus.

Adult↗
PubMedDate not supplied

A new sodium-nitroprusside-infusion controller for the regulation of arterial blood pressure.

Automatic optimization of the infusion rate of sodium nitroprusside (SNP) is achieved by an integrated hardware-software closed-loop controller implemented as a small bedside device. A microprocessor-based blood pressure monitor controls an infusion pump. The shape of the arterial pressure wave is digitally sampled; its analysis incorporates artifact-detection and -rejection routines. The implemented algorithm applies a rule-based closed-loop control that incorporates fuzzy logic. The system models the decision-making ability of the expert, instead of trying to model the patient's physiologic dynamics. Several internal fuzzy-state variables are defined to achieve a clear understanding of mean arterial pressure (MAP) evolution with time. The system performance is very robust, employing, under all possible situations, a sort of "common sense." A clinical trial of the controller was conducted in 60 patients requiring vasodilation therapy for systemic arterial hypertension following cardiac surgery, 20 who had conventional manual control by an experienced nursing staff and 40 who had automated closed-loop control. The first 240 minutes of the postoperative period were closely watched, taking into account 1) the percentage of time during which MAP was within the 10-mmHg wide frame above the target pressure (target gap); 2) the mean difference of pressure values that crossed the boundary of the target gap; 3) the mean SNP-infusion rate. With automatic control, the time mean arterial pressure values were located in the target gap during the first hour amounted to 72.8 +/- 6.7%, vs 51.2 +/- 10.3% in the manual-control group. In the second hour, it was 79.3 +/- 2.5% vs 67.4 +/- 11.7% (p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[An early detection program for respiratory insufficiency in Duchenne's disease: the preliminary results].

Noninvasive mechanical ventilation through a nasal mask is a recently introduced therapeutic tool that represents a noteworthy advance in home treatment for patients with respiratory insufficiency secondary to ventilatory pump failure. We present the preliminary results of a program for early detection of respiratory insufficiency in patients with Duchenne's disease. Sixteen patients (mean age 15.8 years) with this disease were evaluated between January 1994 and January 1995. Mean lung function parameters were FVC 1,440 ml (46.7%), PO2 87.3 mmHg, PCO2 40.8 mmHg, PIM 40.1 cmH2O (30.6%), and PEM 41 cmH2O (25%). Two patients had abnormal pulse oximetry readings at night and abnormal gasometric readings during the day and were started on mechanical ventilation through nasal masks. These 2 patients were older, more hypoxemic and hypercapnic, had lower FVC values and showed greater deterioration of inspiratory and expiratory muscle pressures.

Adolescent↗