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Biomedical subjects

M Navarro

Publications and source records attributed to M Navarro.

At least 235 records · Page 13Linked to original sources
PubMed1994

Quantification of CD24 and CD45 antigens in parallel allows a precise determination of B-cell maturation stages: relevance for the study of B-cell neoplasias.

Quantitative expression, i.e. absolute number of monoclonal antibody molecules bound per cell, was evaluated for CD24 and CD45 by flow cytometry with standards of fluorescence intensity on a panel of normal and neoplastic B cells. The CD24 antigen was expressed at homogeneous high level in fetal bone marrow and liver. Its density decreased progressively in the other normal tissues in parallel with the B-cell maturation. The ratio between CD24 density measured on fetal bone marrow B cells and that seen on adult peripheral B cells was 6:1. The CD45 antigen density was lower on fetal bone marrow cells than in the more mature stages. Fetal spleen lymphocytes and all the mature B lymphocytes displayed the same CD45 density than that seen on normal adult peripheral T cells. The CD24/CD45 antigen density ratio was precisely related to the stage of B-cell maturation. The same pattern of variation of CD24 and CD45 antigen density was seen on B-cell neoplasias, with a significantly higher value of CD24 and lower value of CD45 in acute lymphoblastic leukemias than in chronic malignancies. CD24 and CD45 antigen levels were frequently out of the range observed in the corresponding normal population. Among ALL patients, a low CD24/CD45 antigen density ratio was associated with a good prognosis. These data confirm the interest of an absolute quantitative study for widely distributed antigens.

Antigens, CD↗
PubMed1993

An acute dose of delta 9-tetrahydrocannabinol affects behavioral and neurochemical indices of mesolimbic dopaminergic activity.

Cannabinoid consumption has been reported to affect several neurotransmitter systems and their related behaviors. The present study has been designed to examine cannabinoid effects on certain behaviors, which have been currently located in the limbic forebrain, in parallel to their effects on mesolimbic dopaminergic neurons. To this end, male rats treated with an oral dose of delta 9-tetrahydrocannabinol (THC) or vehicle were used 1 h after treatment for two different behavioral tests or neurochemical analyses of mesolimbic dopaminergic activity. Treatments, behavioral tests and sacrifice were performed in the dark phase of photoperiod because it corresponds to the maximum behavioral expression in the rat. Behavioral tests were a dark-light emergence test, which allows measurements of emotional reactivity, and a socio-sexual approach behavior test, which allows measurements of sexual motivation and also of spontaneous and stereotypic activities. Neurochemical analyses consisted of measurements of dopamine (DA) and L-3,4-dihydroxyphenylacetic acid (DOPAC) contents, tyrosine hydroxylase activity, in vitro DA release and number and affinity of D1 receptors in the limbic forebrain. Results were as follows. THC exposure markedly altered the pattern executed by the animals in both tests. Concretely, THC-exposed animals exhibited a low number of visits to an incentive female in addition to high time spent in the vicinity of an incentive male, both observed in the socio-sexual approach behavior test, and an increased emergence latency to go out of a dark compartment in the dark-light emergence test. However, the fact that THC also decreased spontaneous activity and the frequency of rearing and self-grooming behaviors, in addition to the observations of either low total number of visits to both incentive sexual areas or high escape latency to go out of a light compartment, when the animal is placed in this compartment, also suggest the possible existence of an accompanying motor deficit. These behavioral effects were accompanied by increases in DA and DOPAC contents and in D1 receptor density in the limbic forebrain and to a slight decrease in the pattern of K(+)-evoked DA release in vitro from perifused limbic fragments, with no changes in the remaining neurochemical parameters. Collectively, these results allow us to conclude that acute THC markedly altered the behavioral pattern executed by the animals in a socio-sexual approach behavior test and in a dark-light emergence test, presumably indicating loss of sexual motivation and increased emotionality, although also accompanied by motor deficiencies.(ABSTRACT TRUNCATED AT 400 WORDS)

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

The effect of industrial pollution on mercury levels in water, soil, and sludge in the coastal area of Motril, southeast Spain.

The total concentration of mercury was determined in samples of water, soil and sludge from the Mediterranean coastal area of Southeast Spain (Motril), where Hg contamination is produced primarily by a local paper mill. Samples were taken at surface level in a 5 Km radius from the factory. The total Hg concentrations varied from 0.117 to 0.760 microgram/g in soil and sludge, and from ND to 2.088 micrograms/L in water. A negative correlation was observed between the distance of the sampling station from the mill and the concentration of Hg in the soil and sludge samples. Similarly, an increase in Hg concentration was observed in the freshwater and wastewater after passing close to the factory.

Fresh Water↗
PubMed1993

Motor disturbances induced by an acute dose of delta 9-tetrahydrocannabinol: possible involvement of nigrostriatal dopaminergic alterations.

Exposure to cannabinoids has been reported to affect several neurotransmitter systems and their related behaviors. The present study has been designed to further explore the effects of cannabinoids on motor behavior and test the involvement of nigrostriatal dopaminergic neurotransmission and other neurotransmitters as possible neurochemical targets for these cannabinoid effects. Male rats treated with an oral dose of delta 9-tetrahydrocannabinol (THC), the main psychoactive ingredient of cannabinoid derivatives, or vehicle were used 1 h after treatment for analyses of spontaneous motor and stereotypic activities together with neurochemical analyses of the nigrostriatal dopaminergic activity. Treatments and analyses were performed in the dark phase of photoperiod because it corresponds to the maximum behavioral expression in the rat. Neurochemical analyses were measurements of presynaptic activity--dopamine (DA) and L-3,4-dihydroxyphenylacetic acid (DOPAC) contents, tyrosine hydroxylase (TH) activity, and in vitro DA release--and postsynaptic sensitivity--number and affinity of D1 and D2 receptors--in the striatum. In addition, measurements of 5-hydroxytryptamine (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) contents were also performed to evaluate serotoninergic activity in the striatum. An oral dose of THC produced a loss of spontaneous motor activity, measured in both actimeter and open-field test, and a decrease in the frequency of several stereotypic behaviors, such as rearing and self-grooming. This decrease was correlated to a low number of D1-dopaminergic receptors in the striatum, although neither DA and DOPAC contents nor TH activity and D2 receptors were altered.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Amyotrophic lateral sclerosis in a patient with systemic lupus erythematosus.

We report the case of a 48-year-old woman diagnosed as having systemic lupus erythematosus who developed a neurological disorder that finally resulted in amyotrophic lateral sclerosis. Although neurological disturbances caused by systemic lupus erythematosus are protean, there are no reported cases of amyotrophic lateral sclerosis associating with lupus disease. This association and the suspected autoimmune mechanism of pathogenesis in amyotrophic lateral sclerosis suggest that this might not be a simple coincidence but perhaps a causal relationship.

Amyotrophic Lateral Sclerosis↗
PubMed1993

Technical improvements in corrosion casting of small specimens: a study on mesonephric tubules and vessels of chicken embryos.

The injection technique for corrosion casting of small, embryonic material can be improved by using a "chemical ligature" (cyanoacrylate). With this simple method, leakage of the resin at the injection site is prevented and the mechanical stability of the cannula-vessel coupling is improved. The blood vascular system of chicken embryos as small as Hamburger-Hamilton stage 24 (approximately 4.5 days of incubation) has successfully been injected using this procedure. Corrosion casts of the mesonephric tubular system have been made in a similar manner. Additionally, a simple way for secure transport of the fragile casts by immersion in 10% gelatin is suggested.

Animals↗
PubMed1993

[The pediatric kidney transplant in recipients under 2 years old].

We report our experience with renal transplantation in 7 infants less than 2 years of age. The mean duration of follow-up was 32.4 m. except one who died in the immediate postoperative period. Immunosuppressive therapy consisted of methyl prednisolone, azathioprine, cyclosporin. No patient showed either vascular or lymphatic complications however the infections were frequent. All except one, have their graft functioning well. Graft and patient survival rates were 85% at 36 m. We conclude that renal transplantation in this age group is technically feasible although it needs a team with wide experience in the management of pediatric renal transplantation.

Combined Modality Therapy↗
PubMed1993

[Changes in the flow of the stable renal graft following cyclosporin administration].

To evaluate whether oral CyA may produce changes in the renal vascular bed of the graft, a prospective study was made in 16 children with kidney transplant and normal renal function. A exam with echo-Doppler was realized pre and post two hour after CyA was administered. The doses of CyA was 6.1 +/- 2.7 mg/kg/days (3 doses). The results show that CyA produced in the children with kidney transplant an increase of vascular resistance (renal and interlobar) and a decrease transient of urinary flow. The finding changes in relation to time of administration of the CyA.

Adolescent↗
PubMed1993

[Surgery of acute mitral valve insufficiency].

Between January 1980 and December 1990, 16 patients with acute mitral insufficiency were operated on an emergency basis at our institution. They represented 1.8% of all mitral surgical cases. All of them were in acute pulmonary edema and 7 in cardiogenic shock. The etiology was ischemic in 6, degenerative in 4, infectious in 3, degenerative and infectious in 2 and traumatic in 1. The pathologic mechanism was chordal rupture in 8 patients (5 anterior) and papillary muscle rupture in the other 8 (5 posterior). A mitral valve replacement was performed in all cases. Two patients died and 7 had morbidity in the postoperative period. One patient died 6 months after surgery of congestive heart failure. Ten patients are in NYHA functional class I at a mean follow-up of 48.1 months. Acute mitral insufficiency has different etiologies and pathologic mechanisms. In spite of the severe clinical condition of these patients, mitral valve replacement has good immediate and long-term results.

Acute Disease↗
PubMed1992

[Anti-endothelial cell antibodies in systemic lupus erythematosus: association with vascular and renal lesions].

BACKGROUND: The aim of this study was to know the prevalence and characteristics of endothelial anticellular antibodies (EAA) in systemic lupus erythematosus and its relation with the clinical and immunologic manifestations of this entity. METHODS: A prospective study of 50 patients (44 females and 6 males) diagnosed with SLE was carried out. EAA and anticardiolipin antibodies (ACA) were determined by the ELISA technique, lupic anticoagulant by coagulometric techniques, antinuclear antibodies by indirect immunofluorescence, anti-DNA antibodies by the Farr technique, anti-ENA by contra-immunoelectrophoresis and the complement values by radial immunodiffusion. The statistical study was carried out by chi-square test and Fisher test. RESULTS: Positive titers of EAA were observed in 29 (58%) of the patients with SLE. The patients with EAA presented greater prevalence of both, vascular lesions (31% vs 5%, P < 0.05) and kidney involvement (62% vs 29%, p < 0.05) than those without EAA. Patients with EAA also presented a higher prevalence of antiphospholipid antibodies than patients without EAA (59% vs 10%, p < 0.001). No association was found between EAA and the titers of antinuclear antibodies, anti-DNA, anti-ENA or complement levels. CONCLUSIONS: Endothelial anticellular antibodies appear with greater frequency in patients with systemic lupus erythematosus and are more often associated with vascular and kidney involvement and with the detection of antiphospholipid antibodies suggesting that they may play an etiopathogenic role in the production of these lesions.

Adult↗
PubMed1992

[Chronic myeloid leukemia after chemotherapy treatment for non-Hodgkin's lymphoma].

A 52 year old male presenting chronic myeloid leukemia (CML) Philadelphia chromosome positive (Ph) four years after the diagnosis of a non Hodgkin's lymphoma is described. The patient had received high total doses of alkylating drugs (cyclophosphamide and chlorambucil) as part of chemotherapy treatment for a diffuse mixed lymphoma. At four years of diagnosis of the lymphoma the appearance of hepatosplenomegaly, leukocytosis with myeloma and basophilia and thrombocytosis were observed. These alterations augmented progressively until a cytogenetic study of the bone marrow two years late established the diagnosis of CML upon demonstrating the presence of the Ph chromosome with no other karyotypic anomalies being observed. The explorations carried out at that time confirmed that the lymphoma continued to be in remission. The CML initially responded to treatment with busulphan. However, following a year and a half the disease evolved to a phase of acceleration and the patient died a few weeks later due to pneumonia with no signs indicative of lymphoma activity having been detected since the diagnosis of the CML.

Alkylating Agents↗
PubMed1992

A study of 15 cases of primary mediastinal lymphoma of B-cell type.

Fifteen cases of pure supradiapragmatic lymphoma with initial prominent antero-superior mediastinal involvement displaying a B-cell pattern of reactivity were studied. These cases occurred in six men and nine women with a median age of 33 years at diagnosis (range, 23 to 75 years). Supradiapragmatic peripheral lymphadenopathies were present in three cases, and intrathoracic extension to the lung, pericardium, or pleura was possible. In five cases a thymic origin was obvious. All cases exhibited a B-cell pattern of differentiation, with a great variety of histopathologic aspects associated with a high frequency of fibrosis and/or necrosis. Hodgkin's disease was initially misdiagnosed in four cases. The evolution was purely local, with extrathoracic extension in five cases, at the ultimate phase of the disease. The prognosis appeared to be poor with only five patients still alive at a median survival time of 16 months. A complete chemoresistance and radio-resistance was observed in seven cases; only two complete remissions were achieved with aggressive chemotherapy. Prolonged remission could be achieved after surgical reduction of the mass. Primary B-cell mediastinal lymphoma appears to be a distinct clinical entity with local evolution and resistance to therapy. A new therapeutic regimen, which could include surgery in some cases, should be found for this disease.

Adult↗
PubMed1992

Modifications of striatal D2 dopaminergic postsynaptic sensitivity during development of morphine tolerance-dependence in mice.

Alterations in the activity of striatal dopaminergic neurons have been implicated in the development of morphine tolerance-dependence in rodents. To further explore this possibility, we examined the activity of these neurons in mice exposed to morphine during 4 days (addiction group) and subsequently treated with naloxone (withdrawal group). The efficiency of opiate treatment was assessed behaviorally. Striatal dopaminergic activity was evaluated by measuring: a) the ratio between the amounts of L-3,4-dihydroxyphenylacetic acid (DOPAC), the main intraneuronal metabolite of dopamine (DA), and the neurotransmitter itself, as an index of presynaptic activity; and b) the number and affinity of D1 and D2 dopaminergic receptors, as well as the amount of their coupled second messenger, cyclic adenosine monophosphate (cAMP), as postsynaptic parameters. Spontaneous motor activity was decreased in chronically morphine-exposed mice. In these animals, the number of striatal D2 receptors also decreased, with no changes in their affinity, whereas the number and affinity of D1 receptors remained unchanged. This hyposensitivity of D2 receptors was paralleled by an increase in the amount of cAMP with a good statistical correlation between both parameters. Treatment with naloxone of morphine-exposed mice resulted in the typical jumping behavior indicative of opiate withdrawal. The differences in D2 receptors between placebo- and morphine-exposed mice disappeared after naloxone-induced opiate withdrawal, although this effect was due more to the inhibitory effect of naloxone on the density of these receptors in placebo-exposed mice rather than to a stimulatory effect in morphine-addicted mice. The morphine-induced increase in cAMP content also disappeared after naloxone treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dihydroxyphenylacetic Acid↗