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Biomedical subjects

J L Carrasco

Publications and source records attributed to J L Carrasco.

At least 37 records · Page 2Linked to original sources

Antigenic relationships between chloroplast and cytosolic fructose-1,6-bisphosphatases.

Cytosolic fructose-1,6-biphosphatases (FBPase, EC 3.1.3.11) from pea (Pisum sativum L. cv Lincoln) and spinach (Spinacia oleracea L. cv Winter Giant) did not cross-react by double immunodiffusion and western blotting with either of the antisera raised against the chloroplast enzyme of both species; similarly, pea and spinach chloroplast FBPases did not react with the spinach cytosolic FBPase antiserum. On the other hand, spinach and pea chloroplast FBPases showed strong cross-reactions against the antisera to chloroplast FBPases, in the same way that the pea and spinach cytosolic enzymes displayed good cross-reactions against the antiserum to spinach cytosolic FBPase. Crude extracts from spinach and pea leaves, as well as the corresponding purified chloroplast enzymes, showed by western blotting only one band (44 and 43 kD, respectively) in reaction with either of the antisera against the chloroplast enzymes. A unique fraction of molecular mass 38 kD appeared when either of the crude extracts or the purified spinach cytosolic FBPase were analyzed against the spinach cytosolic FBPase antiserum. These molecular sizes are in accordance with those reported for the subunits of the photosynthetic and gluconeogenic FBPases. Chloroplast and cytosolic FBPases underwent increasing inactivation when increasing concentrations of chloroplast or cytosolic anti-FBPase immunoglobulin G (IgG), respectively, were added to the reaction mixture. However, inactivations were not observed when the photosynthetic enzyme was incubated with the IgG to cytosolic FBPase, or vice versa. Quantitative results obtained by enzyme-linked immunosorbent assays (ELISA) showed 77% common antigenic determinants between the two chloroplast enzymes when tested against the spinach photosynthetic FBPase antiserum, which shifted to 64% when assayed against the pea antiserum. In contrast, common antigenic determinats between the spinach cytosolic FBPase and the two chloroplast enzymes were less than 10% when the ELISA test was carried out with either of the photosynthetic FBPase antisera, and only 5% when the assay was performed with the antiserum to the spinach cytosolic FBPase. These results were supported by sequencing data: the deduced amino acid sequence of a chloroplast FBPase clone isolated from a pea cDNA library indicated a 39,253 molecular weight protein, with a homology of 85% with the spinach chloroplast FBPase but only 48.5% with the cytosolic enzyme from spinach.

Amino Acid Sequence↗

Low platelet monoamine oxidase activity in pathological gambling.

Decreased platelet monoamine oxidase (MAO) activity has been reported in association with sensation-seeking personality type and in some mental disorders associated with a lack of impulse control. Pathological gambling itself has been related with both sensation-seeking and reduced impulse control. Platelet MAO activity was investigated in 15 DSM-III-R pathological gamblers from our outpatient clinic. Gamblers had a significantly lower platelet MAO activity than a group of 25 healthy controls. The range of MAO levels in gamblers was also significantly shorter than in controls. In controls, platelet MAO levels showed the previously described negative correlations with sensation-seeking scores but not in gamblers. The findings are consistent with previous studies showing an association of low platelet MAO activity with impulse control disorders and raise some interesting therapeutic alternatives for pathological gambling.

Adult↗

Ataque de nervios and panic disorder.

OBJECTIVE: Ataque de nervios ("attack of nerves") is an illness category used frequently by Hispanic individuals to describe one or more particular symptom complexes. A review of the literature on ataque suggested some overlap with panic disorder. This study investigated the overlap with panic disorder as well as other DSM-III-R axis I disorders. METHOD: Hispanic subjects seeking treatment at an anxiety disorders clinic (N = 156) were assessed with a specially designed questionnaire for self-report of ataque de nervios and panic symptoms and with structured or semistructured psychiatric interviews for axis I disorders. RESULTS: Seventy percent of the subjects reported at least one ataque de nervios; 80% of these were female, whereas 57% of the group without these attacks were female. There were no differences in DSM-III-R diagnoses between the groups with and without ataque de nervios. Ataque was frequently associated with one or more anxiety and affective disorders, including panic disorder, generalized anxiety disorder, recurrent major depression, and anxiety not otherwise specified. Of the 45 subjects with both ataque de nervios and primary panic disorder, 80% appeared to have labeled panic disorder as ataque. Ataque de nervios was associated with panic symptoms even in subjects without panic disorder, but the self-reporting of ataque conveyed additional clinical information about the subjects with panic disorder. Ataque de nervios was similar in frequency and symptoms among subjects of Dominican and Puerto Rican origin. CONCLUSIONS: Ataque de nervios overlaps with panic disorder but is a more inclusive construct. Further study of its interrelation with axis I disorders is needed.

Adult↗

Alpidem in the treatment of panic disorder.

Alpidem, an imidazopyridine that acts at the gamma-aminobutyric acid/benzodiazepine receptor complex, has been reported to be an effective anxiolytic with a more favorable side effect profile than benzodiazepines. The effect of alpidem was investigated in an 8-week, open, clinical trial in 13 patients with panic disorder, with or without agoraphobia. Three patients were responders (much improved or very much improved), five patients were nonresponders, and five patients dropped out after less than 6 weeks of treatment. Significant improvement was seen in the sample as a whole for spontaneous panic attacks, phobic avoidance, and anticipatory anxiety. Most improvement occurred during the first 4 weeks of treatment, and responders had milder panic disorder at baseline. Adverse effects were generally mild. After 8 weeks of treatment, taper of medication over 2 weeks occurred without significant worsening of panic disorder symptoms. The efficacy of alpidem in the treatment of panic disorder remains uncertain and requires assessment in a controlled trial.

Adolescent↗

Left hemispheric activation in depersonalization disorder: a case report.

Depersonalization disorder is classified in DSM-III-R (APA 1987) as a dissociative disorder characterized by altered perception or experience of the self. To date, there are no known reports of the neurobiological features of this disorder. We report clinical and biological correlates in a patient with depersonalization disorder previously unresponsive to a variety of anticonvulsant, monoamine oxidase inhibitor, and tricyclic antidepressant trials, but for whom fluoxetine partially reduced depersonalization symptoms, but not associated anxiety and depression. Neurophysiological, neuroanatomical and neuropsychological findings revealed left hemispheric frontal-temporal activation and decreased left caudate perfusion. These findings suggest a similarity to the neuropsychiatric data reported in obsessive-compulsive disorder patients.

Adult↗

Plasmatic somatostatin as a marker of positive symptoms of schizophrenia.

1. Somatostatin displays a regulatory function on several aminergic neurotransmitters, including dopamine. In addition, decreased CSF levels of the peptide has been found in Schizophrenia and other neuropsychiatric disorders. 2. In the present work, we have investigated levels of plasmatic somatostatin in a sample of 50 schizophrenic patients compared with a normal control group. 3. Somatostatin was increased in the patient group (p less than 0.01) as a whole but statistical analysis revealed that the increase was associated with the presence of positive symptoms (Factorial Analysis) with a significant correlation, specially with delusion and hallucination scores in the Andreasen rating scales.

Adult↗

[Masked Philadelphia chromosome: diagnostic implications in a case of chronic myeloid leukemia presenting in blast crisis].

We present a female patient with acute non-lymphoblastic leukemia (ANLL) and with haematologic features suggestive of its evolution from chronic myeloid leukaemia (CML), in which a bone marrow karyotype showing a "masked" Philadelphia (Ph) chromosome due to a variant translocation of complex type t(9;9;22)(q32;q34;q11) was found. We comment the peculiarities of this special Ph chromosome as well as the differential diagnostic problems between ANLL Ph(+) and CML with onset in blastic crisis.

Aged↗

Treatment outcome of obsessive compulsive disorder with comorbid social phobia.

BACKGROUND: Treatment of obsessive compulsive disorder (OCD) with serotonin reuptake blockers has been demonstrated effective in 50% to 60% of patients in open and placebo-controlled studies. However, some reports indicate that comorbid Axis II psychopathology, including avoidant personality disorder, and deficiency of social skills could be predictors of a poor response to treatment in OCD patients. METHOD: A retrospective review elicited 12 patients who met DSM-III-R diagnostic criteria for both OCD and social phobia and were treated in our clinic last year with adequate trials of serotonin reuptake blockers or MAOIs. RESULTS: Only 3 (27%) of the 11 patients treated with serotonin reuptake blockers had a substantial improvement of OCD symptoms. Among them, only 1 (11%) of 9 patients with generalized subtype of social phobia versus 2 (100%) of 2 patients with the nongeneralized subtype responded to serotonin reuptake blockers. Four (80%) of 5 patients with comorbid generalized social phobia receiving phenelzine had marked improvement of OCD symptoms. In general, response of social phobia occurred parallel to that of OCD. CONCLUSION: Comorbid generalized social phobia seems to be associated with a poor response to serotonin reuptake blockers in OCD patients. Deficient social skills, as well as distinct biological mechanisms, may be involved. MAOIs might be an effective alternative medication in refractory cases. Larger and controlled studies are needed to define the implications of the association of OCD and social phobia.

Adult↗

Abrupt homeostatic responses to transient intracardiac occlusion during balloon valvuloplasty.

The present study analyzes the hemodynamics of intracardiac occlusive periods during balloon mitral or aortic valvuloplasty and compares them with immediate plasma levels of atrial natriuretic factor (ANF), vasopressin and renin activity. Forty-nine patients were studied; 33 of them had mitral stenosis and 16 had aortic stenosis. The mean age was 52 +/- 17 years. During dilations pressures were monitored from the ascending aorta and left atrium. Plasma levels of ANF, vasopressin and renin were serially determined at baseline, after diagnostic procedures, within 15 to 30 seconds after the first 2 occlusive dilations, and 1 and 7 hours later. There were no significant changes in plasma renin throughout the study stages. ANF and vasopressin significantly increased after the dilations. These hormonal changes were related to the significant hemodynamic changes observed during intracardiac occlusion. The left atrial pressure correlated directly and significantly (r = 0.54, p less than 0.001) with plasma ANF levels throughout the conditions. On the other hand, the plasma vasopressin also correlated (r = 0.76, p less than 0.001) with systemic pressure in an exponential fashion. These findings show that abrupt releases of ANF and vasopressin occur immediately after intracardiac occlusive periods as a response to the acute and transient hemodynamic changes observed.

Adolescent↗

Physiopathology of transient ventricular occlusion during balloon valvuloplasty for pulmonic or aortic stenosis.

Hemodynamic observations were made at different cardiac levels during transient balloon occlusion at the time of aortic or pulmonary valvuloplasty in 37 patients (mean age 8 +/- 9 years); 22 had pulmonary stenosis and 15 had aortic stenosis (6 valvular and 9 discrete subvalvular types). Eighty-two tentative dilatations were performed in patients with pulmonary stenosis and 61 in patients with aortic stenosis. The hemodynamics of the right and left heart were monitored during inflation-deflation time. From selected tracings mean beat-to-beat pressures curves were constructed during occlusion-recovery time. The cycle length (RR interval) did not change significantly during occlusion, except for patients with pulmonary occlusion and patent foramen ovale, where a significant increase in cycle length (p less than 0.01) was observed during recovery time. The mean maximal increase in ventricular pressure reached 95% of basal values for the right ventricle and 58% for the left ventricle. The hypertension was retrogradely transmitted to all cardiac chambers. Angiographic observations during occlusion suggest that the atrioventricular valves and the foramen ovale, when patent, become escape orifices during occlusion, for adapting and relieving intracavitary pressures. The ventricle seems to adapt to sudden occlusion by generating hypertensive and hypokinetic contractions, with atrioventricular regurgitation.

Aortic Valve Stenosis↗

Formula for calculating vaccine profitability.

A mathematical formula is developed for calculating the profitability of real or stimulated vaccination campaigns, in relation to the years elapsed since the vaccination date and within the period of immunity given by the vaccine. According to the formula, profitability depends on the annual attack rates and corresponding costs, vaccine price and efficacy, and number of postvaccination years considered. The factors that do not affect profitability are values of local currency, annual discount rates and the absolute number of vaccines, provided the relative proportion of subjects vaccinated is maintained constant among the distinct risk groups, when comparing different policies. Examples of vaccinations against hepatitis B and measles are presented.

Cost-Benefit Analysis↗

Effects of acute changes in load and inotropic state on the exponential rate of fiber shortening and other indices of myocardial contractility in the anesthetized intact dog.

The effects of an acute increase in preload, afterload, and inotropic state on several indices of left ventricular contractility were studied in 20 anesthetized intact dogs. The behaviour of the exponential rate of fiber shortening (ERFS), a newly described index, which is based on the instantaneous fiber length--time relationship through ejection, was compared with other classical ejection and isovolumic indices of left ventricular contractility. Acute volume overload by dextran 40 infusion produced a significant increase in preload as reflected by a 103% (p less than 0.01) increase in left ventricular end-diastolic pressure and a 121% (p less than 0.001) increase in end-diastolic circumferential wall stress. There was also a smaller but significant increase (p less than 0.05) of heart rate (30%) and of peak systolic circumferential wall stress (24%). None of the left ventricular contractility indices showed any significant change. Acute pressure overload, produced mechanically by an aortic balloon, increased the afterload significantly as reflected by a 33% (p less than 0.05) rise of end-systolic circumferential wall stress and a 43% (p less than 0.001) increase in systemic resistance. Stroke volume decreased significantly by 23% (p less than 0.05). All ejection indices, including ERFS, were significantly diminished by 30-37%; all isovolumic indices showed no significant changes. Positive inotropic intervention was induced by dopamine infusion, which caused a significant 28% (p less than 0.05) increase in cardiac output. End-diastolic and end-systolic circumferential wall stress were significantly diminished. All indices of left ventricular contractility increased significantly and ERFS showed the quantitatively greatest change.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Natural immunity to measles, rubella and mumps among Spanish children in the pre-vaccination era.

Prior to the start of mass vaccination campaigns against measles, rubella and mumps, a prevalence study of natural immunity to these diseases was undertaken in a sample of 1700 unvaccinated Spanish children. They were representative of the 3-7 year-old population in terms of age, regional distribution and urban or rural environment. Measles infection prevalence was significantly higher than that for rubella and mumps from 3 (48.3%, 14.2%, 25.5%, respectively) through 7 years of age, (64%, 40.9%, 39%). As a function of age, naturally-acquired immunity increased according to parabolic progressions. In the 3-5 year-old group, rural environment, low socioeconomic status, no school attendance and lack of brothers were associated with statistically lower levels of measles, rubella, or mumps infection. In the 6-7 year-old group, only 12% of the children showed antibodies against the three diseases and 18.7% exhibited triple susceptibility.

Age Factors↗