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Biomedical subjects

C Vidal

Publications and source records attributed to C Vidal.

At least 109 records · Page 6Linked to original sources
PubMed1992

Three cases of allergic dermatitis due to intravesical mitomycin C.

Irritant contact dermatitis has frequently been described in association with mitomycin instillation into the bladder. Three cases of allergic contact dermatitis in which patch tests demonstrated a type IV hypersensitivity reaction are reported. Patients showing skin reaction during mitomycin C vesical instillation should be patch tested to make a decision whether the drug might be continued (toxic reaction) or discontinued (allergic reaction).

Administration, Intravesical↗
PubMed1992

Toxic epidermal necrolysis due to vancomycin.

Toxic epidermal necrolysis due to vancomycin is reported in a patient with human immunodeficiency virus infection. The same patient had anaphylaxis to cloxacillin but tolerated other penicillin derivatives. These reactions were documented using in vivo and in vitro tests. The role of human immunodeficiency virus infection in the pathogenesis of these reactions is discussed.

AIDS-Related Complex↗
PubMed1991

Bronchial asthma due to Cannabis sativa seed.

A 51-year-old man with asthmatic attacks due to Cannabis sativa seed inhalation was studied. Specific IgE against this seed was demonstrated by in vivo (skin and bronchial challenge tests) and in vitro methods (reverse enzyme immunoassay and histamine release from basophils), suggesting a Type I immunologic reaction.

Allergens↗
PubMed1991

Tracheobronchomegaly associated with interstitial pulmonary fibrosis.

Tracheobronchomegaly (TBM) is the syndrome of enlarged trachea and main bronchi associated with recurrent and chronic respiratory tract infections. A 42-year-old man with TBM and diffuse interstitial pulmonary fibrosis is described. The possible relationship between the two entities is discussed and the etiology, pathogenesis, clinical manifestations, prognosis and treatment of TBM are reviewed.

Adult↗
PubMed1991

Non-bacterial thrombotic endocarditis in cancer patients.

A total of 10 cases of non-bacterial thrombotic endocarditis (NBTE) were found among 1640 adult patients, autopsied in a 24-year period. Eight out of 10 patients had an underlying malignant tumor, NBTE was more common in cancer patients than in patients without malignancy (1.25% vs 0.2%, P less than 0.05). Patients with adenocarcinoma were at higher risk than patients with other malignant processes (2.70% vs 0.47%, P less than 0.05); especially in cases of pancreatic cancer in comparison with other kinds of adenocarcinoma (10.34% vs 1.55%, P less than 0.05). Systemic embolization was the main cause of morbidity. Any thromboembolic event in cancer patients should prompt a search for NBTE. NBTE may be present in undisseminated cancers in otherwise curable patients.

Adenocarcinoma↗
PubMed1991

Existence of different subtypes of nicotinic acetylcholine receptors in the rat habenulo-interpeduncular system.

Neuronal nicotinic ACh receptors (nAChRs) are present in the rat medial habenula (MHB) and interpeduncular nucleus (IPN), two brain regions connected through the fasciculus retroflexus (FR). The goal of the present study was to compare the electrophysiological and pharmacological characteristics of nAChRs located at pre- and postsynaptic sites within the MHB-IPN system. nAChRs located on the soma of IPN neurons were studied using patch-clamp techniques and a preparation of acutely isolated neurons. Whole-cell currents evoked by Ach and nicotine showed an intense rectification at positive membrane potentials. nAChR channels were relatively nonselective for cations, had a unitary conductance of 35 pS, and were activated by several nicotinic agonists with the following rank order: cytisine greater than ACh greater than nicotine greater than dimethylphenylpiperazinium (DMPP). They were blocked by mecamylamine, hexamethonium, curare, and dihydro-beta-erythroidine (DHBE), but were insensitive to alpha-bungarotoxin and neuronal bungarotoxin. In contrast, nAChRs recorded on the soma of MHB neurons under equivalent experimental conditions exhibited different characteristics for single-channel conductance and agonist and antagonist sensitivity. The pharmacological properties of presynaptic nAChRs in the IPN were analyzed in a rat brain slice preparation. Stimulation of the FR produced a presynaptic afferent volley recorded in the rostral subnucleus of the IPN. Nicotinic agonists decreased the amplitude of the afferent volley with different efficacies: nicotine greater than cytisine greater than ACh greater than DMPP. The action of nicotine was insensitive to alpha-bungarotoxin and to neuronal bungarotoxin, but was blocked by mecamylamine, hexamethonium, curare, and DHBE, with IC50 values different from those reported for IPN postsynaptic nAChRs. This study thus demonstrates the functional diversity of nAChRs in the rat CNS.

Animals↗
PubMed1990

Seborrheic dermatitis and HIV infection. Qualitative analysis of skin surface lipids in men seropositive and seronegative for HIV.

We measured skin surface lipids (cholesterol, free fatty acids, triglycerides, wax esters, and squalene) in patients seropositive for human immunodeficiency virus (HIV) and those seronegative for HIV with and without seborrheic dermatitis. Cholesterol and wax ester fractions were similar in all four groups but triglycerides and squalene were significantly increased and free fatty acids significantly decreased in HIV-positive patients, regardless of the presence of seborrheic dermatitis. In addition, a strong negative correlation was found between free fatty acid and triglyceride levels. We conclude that abnormalities of skin surface lipids are not associated with the development of seborrheic dermatitis in HIV-positive persons but are associated with HIV infection itself.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[The Cambridge Mental Disorders of the Elderly Examination. Validation of the Spanish adaptation].

A neurologist and a psychiatrist diagnosed independently, according to DSM-III-R and ICD-10 criteria, to 15 subjects with dementia, 15 with depression and 15 without any of two previous diagnostics. Later, a psychologist held an interview with them by means of the structured interview CAMDEX. The lump levels of agreement between clinical diagnostic and DSM-III-R diagnostic obtained through CAMDEX is of Kappa = 0.63. These levels are increased to one Kappa = 0.76 if we compare the clinical diagnostic with CAMDEX diagnostic according to the ICD-10. On the other hand, we value the outputs of some instruments that are included in the CAMDEX: Mini Examen Cognoscitivo, Mini-Mental State, CAMCOG, Organicity Scale, Blessed Scale and Depressión Scale.

Aged↗
PubMed1990

[The Cambridge Mental Disorders of the Elderly Examination. Study of interobserver reliability].

Three teams formed by psychologists with experience in the administration of structured interviews evaluated by the CAMDEX (The Cambridge Mental Disorders of the Elderly Examination) in a sample of 41 patients for the interrater reliability study. While a psychologist interview patient, the other one observes each patient. The CAMDEX were completed independently by each of the examiners. The results demonstrate an elevated level agreement both for the different scales (p less than 0.001) and for the different diagnostic criteria employed by the CAMDEX (kappa = 0.88 for the DSM-III-R and Kappa = 1 for the ICD-10).

Aged↗
PubMed1989

Pharmacological profile of nicotinic acetylcholine receptors in the rat prefrontal cortex: an electrophysiological study in a slice preparation.

The specificity of nicotinic receptors in the neocortex has been questioned previously because: (i) electrophysiological responses to nicotine could not be blocked by nicotinic antagonists, and (ii) the effect of nicotine was not mimicked by acetylcholine. In the present study, the presence of functional nicotinic receptors in rat neocortex has been assessed in a slice preparation of prefrontal cortex, using evoked field potential and unit recordings. Nicotine and the nicotinic agonists, dimethylphenylpiperazinium, cytisine, acetylthiocholine, applied by iontophoresis, produced an increase in the negative wave of field potentials, reflecting an increased excitability of cortical neurons. This effect was blocked by the selective probe for neuronal nicotinic receptors Toxin F (1.4 microM in the perfusion medium) and by dihydro-beta-erythroidine (100 microM). Alpha-bungarotoxin, the blocker of skeletal muscle acetylcholine receptor had no effect. Iontophoretically applied acetylcholine, muscarine and pilocarpine, on the other hand, produced a decrease in the field potential amplitude, which was blocked by atropine and scopolamine (1-10 microM). In the presence of eserine (10 microM), the muscarinic effect of acetylcholine was dramatically altered, leading to the development of a nicotinic response sensitive to Toxin F. Thus, the physiological activation of nicotinic receptors in rat prefrontal cortex appears to require higher concentrations of acetylcholine than do muscarinic receptors. Our results show that: (i) the rat prefrontal cortex possesses functional nicotinic receptors with a pharmacological profile clearly distinct from muscle receptors, and (ii) a nicotinic effect of acetylcholine can be revealed when its degradation by acetylcholinesterase is inhibited.

Acetylcholine↗
PubMed1988

Human T lymphotropic virus I infection deregulates surface expression of the transferrin receptor.

Human T-lymphotropic virus I (HTLV-I) is an etiologic agent in adult T cell leukemia. In an effort to understand the relationship between HTLV-I infection and malignant transformation, we have examined transferrin receptor expression in HTLV-I-infected cells. Transferrin receptor expression in normal T cells is tightly regulated and essential for cell proliferation. We have used matched T cell sets originating from a normal donor, consisting of tetanus toxoid-specific normal T cell clones (TM3 and TM5) and their in vitro HTLV-I-infected counterparts (TM3H and TM5H). Using these matched sets of virus-infected and normal T cells, we have determined that HTLV-I infection leads to hyperexpression of surface transferrin receptors (five- to six-fold higher than normal counterparts). Although the growth rates of the virus-infected cells did not differ significantly from their normal controls, HTLV-I-infected cells constitutively hyperexpressed surface transferrin receptors, whereas the level of surface receptor expression of normal counterpart cells varied during the cycle of antigenic stimulation. Immunoprecipitation of total (surface plus cytoplasmic) transferrin expression showed that the HTLV-I-infected cells did not possess a greater total number of transferrin receptors than their normal counterparts. This data was supported by Northern blot analysis, which showed equivalent transferrin receptor mRNA expression in HTLV-I-infected and uninfected cells. Functional analysis revealed a marked defect in 59Fe-transferrin internalization in the HTLV-I-infected cells. Furthermore, the HTLV-I-infected cells showed markedly decreased transferrin receptor phosphorylation and internalization in response to active phorbol ester. Thus the data demonstrate that in peripheral blood T cells, HTLV-I infection is accompanied by surface transferrin receptor overexpression secondary to subcellular redistribution and defective internalization.

Cell Membrane↗
PubMed1986

Corticosterone reduces the excitability of hippocampal pyramidal cells in vitro.

In the rat brain, the hippocampus (HC) is a major target area for corticosterone (CT). In this study, we investigated the effects of CT in the in vitro slice preparation of the rat HC. Population spikes (PS) evoked by stratum radiatum stimulation were recorded in CA1. Bath-applied CT (10(-7)-10(-5) M) induced a decrease in the PS amplitude. This effect occurred within 10-15 min after the onset of CT perfusion, reached a plateau after 20-40 min and was reversible after 20 min washout. Neither dexamethasone (10(-5) M) nor vehicle produced any significant change in PS amplitude. Paired-pulse stimulation showed that the degree of inhibition of the second PS produced by the conditioning stimulus was either unchanged or decreased by CT. In the latter case, CT also reduced the inhibitory effect of gamma-aminobutyric acid on PS and enhanced the excitatory action of the opioid peptide D-Ala2-D-Leu5-enkephalin. These results show that CT reduces the excitability of HC pyramidal cells with a time course which may be compatible with a genomic action of CT. The fact that paired-pulse inhibition was either not changed or reduced, suggests that the decrease in PS size by CT is not due to an indirect excitatory effect of CT on inhibitory interneurons. Instead, CT may hyperpolarize pyramidal cells thus lowering their excitability and depressing the interneurons involved in recurrent inhibition.

Animals↗