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C Vidal

Publications and source records attributed to C Vidal.

At least 91 records · Page 5Linked to original sources
PubMed1996

A pilot case-control study of zidovudine compared with zidovudine plus didanosine in patients with advanced HIV-1 disease and no previous experience with antiretrovirals.

Although zidovudine (ZDV) is effective in HIV-1-infected patients, the duration of its efficacy may be short when treatment is started in advanced HIV disease. This pilot prospective case-control study was designed to evaluate the combination of ZDV plus didanosine [ddI] compared with ZDV monotherapy as an initial therapeutic strategy. 'Control' patients (ZDV monotherapy) were matched with 'case' patients (ZDV plus ddI combination therapy) according to the presence or absence of AIDS-defining criteria at entry and CD4 cell count. The case patient group consisted of 35 consecutive HIV-1-infected individuals with < or = 300 CD4 cells/mm3, no previous experience of antiretroviral therapy and who accepted treatment with a combination of ZDV plus ddI. The control patient group consisted of 35 consecutive patients with similar characteristics, but who preferred to start treatment with ZDV alone. Control patients received 250 mg ZDV bid and case patients received ZDV at the same dose plus ddI (200 mg bid). Primary study endpoints were virological (serum HIV-1 RNA) and immunological (CD4 cell count) responses. Viral phenotype (syncytium-inducing (SI) or non-syncytium-inducing (NSI)), development of mutations at codons 215, 41 and 74 and clinical progression (new AIDS-defining event or death) were also assessed. Virological and CD4 cell count responses were significantly greater and more sustained in the group treated with ZDV plus ddI than in the control group, with peak responses of -1.2 +/- 0.7 log10 versus -0.3 +/- 0.4 log10 at 1 month (P = 0.0003) and 61 +/- 52 cells/mm3 versus 19 +/- 25 cells/mm3 at 2 months (P = 0.001), respectively. In both groups the percentage of patients developing a mutation at codon 215 was around 80 per cent at 12 months. A mutation at codon 74 was detected in 30 per cent of case patients at 12 months. Five case patients (14 per cent) versus 12 control patients (34 per cent) showed signs of clinical progression (P = 0.09). In a multivariate model, clinical progression was significantly associated with a baseline

Adult↗
PubMed1995

[Common health disorders: self-care and self-medication].

SETTING: Community level. "Santa María de Benquerencia" Health District, Toledo. PARTICIPANTS: People over 15, chosen by random sampling from the municipal census, who stated that they had suffered some health disorder over the previous fortnight. MEASUREMENTS AND MAIN RESULTS: 212 surveys were accepted as valid (average age 42.75, 51.89% male and 48.11% female). 73% had suffered one of the disorders included in the survey during the previous fortnight. The commonest response was self-medication (39.84%), especially when dealing with pain and Pyrosis. Pyrazolones and Salicylates were the most commonly used drugs. The instructions were only read in 48.64% of cases. No measure was adopted in 34.56% of the disorders. The doctor was only consulted in 6.86% of cases. Both these responses were more common in men and young people. Non-pharmacological self-care was adopted in 30.07% of cases. This was generally of a dietetic or physical nature and was commoner in women and elderly people. CONCLUSIONS: Self-care, whether pharmacological or not, is the most common response to the perception of some symptom. These practices (especially self-medication because of its possible attendant problems) should be directed and used as one tool more in health care.

Adult↗
PubMed1995

Nicotinic and muscarinic receptors in the rat prefrontal cortex: differential roles in working memory, response selection and effortful processing.

The aim of the present study was to evaluate the effects of cholinergic receptor blockade in the rat prefrontal cortex on cognitive processes. The nicotinic antagonists neuronal bungarotoxin and dihydro-beta-erythroidine and the muscarinic antagonist scopolamine were injected into the prelimbic area of the prefrontal cortex. Their behavioural effects were assessed in a T-maze to test reference memory (visual discrimination task) and working memory in delayed matching (MTS) and non-matching to sample (NMTS) tasks. Neuronal bungarotoxin produced a significant decrease in working memory performance in the MTS task but not in the NMTS task. In contrast, scopolamine impaired working memory in both MTS and NMTS tasks. Reference memory was not altered by any of the cholinergic antagonists. These results demonstrate a differential role of nicotinic and muscarinic receptors in the rat prefrontal cortex. Nicotinic transmission appears to be important in delayed response tasks requiring effortful processing for response selection, while the muscarinic system is involved in general working memory processes.

Acetylcholine↗
PubMed1995

Narcolepsy associated with arteriovenous malformation of the diencephalon.

Narcolepsy associated with localized brain lesions is rare, and few reports of well-documented cases have been published. We describe the case of a 20-year-old male (HLA DQw1 negative) who fulfilled clinical and polygraphic criteria of symptomatic narcolepsy. Narcolepsy in this patient was associated with an arteriovenous malformation involving the structures around the third ventricle. Clinical symptoms improved after embolization and radiosurgery. These findings support the hypothesis that lesions in the vicinity of the third ventricle can cause symptomatic narcolepsy.

Adult↗
PubMed1995

Increased serum IgE in alcohol abusers.

BACKGROUND: It has been reported that total serum IgE is increased in patients with alcoholic cirrhosis, but it is not clear if this fact is related to alcoholic liver disease or to alcohol intake. OBJECTIVE: To measure serum IgE in a group of chronic alcoholics with different stages of liver injury in order to elucidate if IgE increase in related to alcoholic liver damage. PATIENTS AND METHODS: Total serum IgE was determined by enzyme immunoassay in 186 chronic alcoholic patients (137 male/49 female) and 101 healthy controls. Patients and controls with known reasons for IgE elevation were excluded. Among alcoholic patients, 24 had fatty liver, 28 hepatic fibrosis, 29 alcoholic hepatitis, and 67 liver cirrhosis (38 patients were not evaluable concerning liver injury). RESULTS: Total serum IgE was found to be increased in alcoholics (median 154.5 IU/mL, range 1-7329 IU/mL) with respect to healthy controls (median 20 IU/mL, range < 1-1417 IU/mL) (P < 0.001). IgE increase was moderate (180-1000 IU/mL) in 60 alcoholics (32.3%) and marked ( > 1000 IU/mL) in 27 (14.5%). Male alcoholics had higher IgE levels than females (median 191 IU/mL and range 1-7329 IU/mL vs 105 IU/mL and range 2-2189 IU/mL) ( P = 0.009). On logistic regression analysis, alcoholism, male sex and younger age (but not smoking) were independently associated with higher IgE levels. No clear relationship was noted between serum IgE and severity of alcoholic liver disease. Thus, no correlation was observed between IgE and parameters of liver function (serum bilirubin, albumin or prothrombin index). Likewise, IgE concentrations were not significantly different in patients with liver cirrhosis with respect to patients with less severe liver disease. Serum IgE was increased ( > 180 IU/mL) in 47.8% of cirrhotics and in 44% of patients without liver cirrhosis. In contrast, other immunoglobulins (IgG, IgA and IgM) were significantly correlated with liver dysfunction. CONCLUSION: Chronic alcoholism should be considered as a cause of increased total serum IgE, regardless of the severity of the underlying liver disease.

Adolescent↗
PubMed1995

Food-induced and occupational asthma due to barley flour.

BACKGROUND: Occupational exposure to inhalant allergens may induce asthma but the presence of asthma after the ingestion of the allergen is rarely reported. OBJECTIVE: To clarify the clinical relevance of every identified allergen in a patient with respiratory symptoms after exposure to feeding stuffs and cereal flours in his work environment and after ingestion of beverages made of these cereal grains. METHODS: Case report. Skin prick tests and serum-specific IgE (CAP-FEIA-fluoroenzymeimmunoassay) were used in order to identify specific IgE antibodies. Bronchial provocation tests were performed as an aid in determination of clinical relevance of occupational exposure to the patient's asthma. RESULTS: A 50-year-old man developed bronchial asthma both after exposure to feeding stuffs and flours and after ingestion of beverages made of cereal flours. Allergy to storage mites (Lepidoglyphus destructor), house dust mites (Dermatophagoides pteronyssinus and farinae), and barley and corn flours were demonstrated by skin testing and serum-specific IgE. Bronchial challenge tests with every allergen showed no response except for an immediate response to barley flour. The most relevant clinical feature was an immediate asthmatic response developed after oral provocation with either barley-made beer or barley flour itself which indicates IgE-mediated, food-induced bronchial asthma (sulfite sensitivity was ruled out). CONCLUSION: In some particular cases, barley flour may induce bronchial asthma through inhalational and oral routes due to an IgE-mediated mechanism.

Beer↗
PubMed1994

Working memory, response selection, and effortful processing in rats with medial prefrontal lesions.

This study examined the effects of lesions of the prelimbic area of the rat prefrontal cortex on acquisition and retention of nonmatching (NMTS) and matching-to-sample (MTS) tasks. Both tasks involved a reference and a working memory component, but only working memory was impaired by the lesions. A comparison of the 2 tasks revealed quantitatively similar deficits in postoperatively trained rats. In preoperatively trained rats, however, the deficits were more important in the MTS task than in the NMTS task. In addition, an effect of interference between successive trials was observed in the NMTS task but not in the MTS task. Perseverative tendencies were observed in the MTS task only. These results suggest that prefrontal lesions induce working memory deficits as a result of poor temporal encoding and increased susceptibility to interference and impair effortful processing, such as that engaged in response selection mechanisms.

Animals↗
PubMed1994

Serum IgE levels in liver cirrhosis. Contrasting results in alcoholic and non-alcoholic patients.

Hypergammaglobulinemia is a well-known feature of liver cirrhosis, but studies on serum IgE in this setting are limited. The present study evaluates serum IgE concentration in a group of cirrhotic patients and examines their relationship with aetiological, clinical and analytical parameters (including liver function tests and hepatic phagocytic activity). The presence of specific IgE against common dietary antigens was also investigated. Total serum IgE was determined by enzyme immunoassay (EIA) in 52 cirrhotics (27 alcoholic and 25 non-alcoholic, including eight virus B and seven virus C-related cirrhosis, three primary biliary cirrhosis, three cryptogenic, three haemochromatosis and one Wilson's disease) and 34 healthy subjects (used as controls). Serum IgE (IU/ml) in controls was not significantly different from that of cirrhotic patients (median 42, range 2-726 vs median 86, range 2- > 1000, respectively) (P = NS). However, serum IgE among alcoholics (median 199, range 19- > 1000) was higher than that of controls (P < 0.001), virus B-related cirrhotics (median 25, range 3- > 1000) (P < 0.05), virus C-related cirrhotics (median 47, range 2-170) (P < 0.05), or non-alcoholic cirrhotics as a whole (median 23, range 2- > 1000) (P < 0.01). High IgE levels (> or = 170 IU/ml) were detected in 55.5% of alcoholics compared with only 12% of non-alcoholic cirrhotics (P < 0.01). Moreover, IgE levels were very high (> 1000 IU/ml) in six patients of the alcoholic group (22.2%) compared with only one non-alcoholic patient (4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Up-regulation of somatostatin receptors by epidermal growth factor and gastrin in pancreatic cancer cells.

Interactions between growth factor receptor systems may be important in the regulation of cell growth. The proliferation of pancreatic tumor AR42J cells has been shown to be stimulated by Epidermal growth factor (EGF) and gastrin and inhibited by somatostatin. To analyze the interaction between these different peptides, we explored the influence of EGF and gastrin on the somatostatin receptors. Treatment of AR42J cells with 10 nM EGF or gastrin for 24 hr increased specific binding of [125I] Tyr3SMS to 131 and 147% of that in control cells, respectively. The effect of peptides on [125I]Tyr3SMS binding was time- and dose-dependent, with half-maximal effect at 0.2 +/- 0.03 nM EGF and 0.3 +/- 0.15 nM gastrin. Scatchard plots revealed an increase in somatostatin receptor number of 27 and 80% after 48 hr of treatment with EGF and gastrin, respectively, without any change in receptor affinity. The increase in somatostatin receptor density was accompanied by the enhancement of biological responses to somatostatin. In cells pretreated with EGF or gastrin, the potency of somatostatin for inhibiting vasoactive intestinal peptide-stimulated cAMP content was increased 2-fold as that of somatostatin analog, SMS, for inhibiting cell proliferation. Furthermore, the efficiency of SMS as antiproliferative agent was greatly increased. Vasoactive intestinal peptide or forskolin did not modify [125I]Tyr3SMS binding of control or treated cells. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) did not affect [125I]Tyr3SMS binding. On the other hand, cycloheximide completely blocked the increase in [125I]Tyr3SMS binding induced by EGF and gastrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1993

Nicotinic and muscarinic modulations of excitatory synaptic transmission in the rat prefrontal cortex in vitro.

The importance of the cholinergic innervation of the neocortex in cognitive functions has been shown in a number of clinical and animal studies. Until recently, attempts to study the mode of action of acetylcholine in the neocortex have concentrated on muscarinic effects, whereas cholinergic actions mediated by nicotinic receptors have been difficult to demonstrate. The present work was undertaken to study the mechanism of action of nicotinic agents on cortical neurons and compare it to muscarinic effects by means of intracellular recordings in a slice preparation. The study was performed in the prelimbic area of the rat prefrontal cortex, a cortical region particularly involved in cognitive processes. Recordings were made from pyramidal cells located in layers II/III and synaptic potentials were evoked by stimulation of superficial cortical layers. Iontophoretic applications of nicotinic agonists (nicotine, dimethylphenylpiperazinium, cytisine) increased the amplitude of the monosynaptic excitatory postsynaptic potential mediated by non-N-methyl-D-aspartate glutamate receptors in 14% (22/159) of cells. This effect was abolished by the selective nicotinic blocker, neuronal bungarotoxin (IC50 = 0.6-0.7 microM) and by dihydro-beta-erythroidine (IC50 = 20-30 microM), whereas hexamethonium, mecamylamine, curare and alpha-bungarotoxin were ineffective. The nicotinic agonists did not change resting membrane potential, input resistance or current-voltage relationship. They also did not affect the depolarizations produced by glutamate applied by iontophoresis in the somatic or dendritic area. In contrast, the muscarinic agonists (muscarine, acetyl-beta-methylcholine) decreased the amplitude of the excitatory postsynaptic potential in 100% of the neurons tested. Atropine was more effective (IC50 = 0.08 microM) than pirenzepine (IC50 = 2 microM) to antagonize the muscarinic action. These effects were observed in the absence of any direct postsynaptic change in membrane potential or input resistance, provided that the site of the iontophoretic application was more than 100 microM distant from the soma. The muscarinic agonists did not influence the actions of iontophoretically applied glutamate. These results suggest that nicotinic and muscarinic agonists modulate excitatory synaptic transmission mediated at dendritic sites by non-N-methyl-D-aspartate glutamate receptors, possibly through a presynaptic action. Thus ascending cholinergic systems may take part in information processing in the prefrontal cortex through the control of ongoing excitation to pyramidal cells.

2-Amino-5-phosphonovalerate↗
PubMed1993

Arthroscopic lysis in knee arthrofibrosis.

Arthrofibrosis continues to be a difficult complication in articular surgery on the knee. We present our experience in 21 cases of arthroscopic lysis as an alternative to mobilization under anesthesia. The technique begins with the liberation of the adhesions of the suprapatellar pouch, continues down both gutters, and ends with a cleaning of the notch where necessary. When a restriction of patellar mobility persists, we make a retinacular release. The results obtained are very satisfactory, with an average increase in the arc of mobility of 68 degrees. The average gain in mobility at 6 months is significantly greater than that achieved in the immediate postoperative period. Longer follow-up showed no improvement in range of motion after 6 months.

Adult↗
PubMed1993

Influence of Kupffer cell phagocytosis blockade on the production of ovalbumin-specific IgE and IgG1 antibodies in an experimental model.

The aim of the present study was to evaluate the influence of Kupffer cell phagocytosis blockade (KCPB) on the production of reaginic (IgE) and non-reaginic (IgG1) ovalbumin antibodies in an experimental animal model. Forty-two female heterozygous Gunn rats were injected with two 100 micrograms doses of ovalbumin separated by 13 days, into jugular vein (Group I, n = 10), portal vein (Group II, n = 10), jugular vein with prior KCPB (Group III, n = 10) and portal vein with prior KCPB (Group IV, n = 12). KCPB was induced with gadolinium chloride (5 mg/kg body weight, 24 hr before each ovalbumin administration). Antibodies were determined by passive cutaneous anaphylaxis in sera obtained 12 days after the first dose of ovalbumin and 8 days after the second one. No antibodies were detected at any time in Group II. The maximum response was observed in Group IV in which, after two doses of ovalbumin, 100% of the animals presented IgG1 and 58% presented detectable IgE antibodies. Differences between group IV and the other groups were statistically significant. This phenomenon does not seem to be due to a systemic effect of gadolinium chloride since humoral response was not increased in Group III with respect to Group I. It is concluded that the liver represents a barrier to IgE and IgG1 sensitization. KCPB not only eliminates this barrier, but also clearly increases antibody production to a protein antigen (ovalbumin) arriving at the liver through the portal vein.

Animals↗
PubMed1992

[Rapid method for identifying Escherichia coli and species of the Proteeae tribe in urine].

BACKGROUND: To evaluate the possibility of using the determination of beta-glucuronidase and phenylalanine deaminase activity directly from urine samples for rapid detection (2 hours) of the presence of Escherichia coli and species of the Proteeae tribe. METHODS: To detect beta-glucuronidase activity methyl-umbelipheryl-beta-D-glucuronic was used as a substrate. The presence of fluorescence after incubation at 37 degrees C for 2 hours indicated a positive reaction. While phenylalanine was used as a substrate for detecting phenylalanine deaminase activity, FeCl3 was added after incubation at 37 degrees C for 2 hours with a greenish color being observed indicating phenylalanine deaminase activity. RESULTS: The detection of Escherichia coli by beta-glucuronidase activity presented sensitivity and specificity of 0.91 and 0.99, respectively. The positive predictive value was 0.96 and the negative predictive value was 0.98, whereas the determination of the phenylalanine deaminase activity with the aim of detecting species of the Proteeae tribe presented the following results; sensitivity 0.92, specificity 0.99, positive predictive value 0.94 and negative predictive value 0.99. CONCLUSIONS: The determination of beta-glucuronidase and phenylalanine deaminase activities directly from urine sediment has been demonstrated as a rapid and specific test for detecting the presence of Escherichia coli and species of the Proteeae tribe, therefore it must be considered as a useful test in early diagnosis of urinary infection thereby facilitating the administration of appropriate antibiotic treatment.

Amino Acid Oxidoreductases↗
PubMed1992

Basic fibroblast growth factor induces proliferation of a rat pancreatic cancer cell line. Inhibition by somatostatin.

AR4-2J, a rat pancreatic acinar-tumor cell line, was used to investigate long-term effects of basic fibroblast growth factor (bFGF) and somatostatin on pancreatic cancer cells. We observed that bFGF stimulated cell proliferation when cells were cultured in serum-free medium. The effect was dose-dependent with half-maximal and maximal effects at 25 pM and I nM bFGF, respectively. The somatostatin analog SMS 201-995 (SMS) decreased the growth-promoting effect of bFGF. The maximal effect was observed at I nM SMS and the half-maximal effect at 20 pM SMS. Characterization of bFGF receptor-binding properties with [125I]bFGF revealed that AR4-2J cells exhibited 2 classes of bFGF binding site with respective KD values of 47 pM and 3 nM and binding capacities of 14 fmol and 0.9 pmol/10(6) cells. High-affinity receptors correlated with bFGF stimulation of AR4-2J cell growth, suggesting that the effects of bFGF are receptor-mediated.

Animals↗
PubMed1992

Characterization of a membrane tyrosine phosphatase in AR42J cells: regulation by somatostatin.

A phosphotyrosyl protein phosphatase (PTPase) activity has been characterized in the plasma membranes of confluent AR42J pancreatic tumor cells using 32P-labeled poly(Glu, Tyr) as substrate. Membrane PTPase activity exhibited an apparent Michaelis constant of 3 microM and an apparent maximal velocity of 0.9 nmol.min-1.mg-1. It was inhibited by orthovanadate, zinc, poly(Glu,Tyr) and was stimulated by EDTA and dithiothreitol. Gel filtration of solubilized plasma membranes gave a peak of enzyme activity at a relative molecular weight of 70,000. Plasma membrane PTPase activity was changed during AR42J cell growth. At the beginning of culture, the control PTPase activity was minimal. Over the 5 days of culture, PTPase activity increased to reach a maximum (3.5-fold over control activity) preceding confluency by 2 days. Then the high level of PTPase activity was sustained until confluency. Incubation of the cells with the stable somatostatin analogue SMS 201-995 (SMS) resulted in a rapid and transient activation of crude membrane PTPase activity. Activation reached a maximum level within 5 min of addition and return to control levels within 20 min. The effect of SMS was dose dependent with half-maximal and maximal activation occurring at 6 pM and 0.1 nM SMS respectively.

Animals↗