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S Carrasco

Publications and source records attributed to S Carrasco.

At least 19 recordsLinked to original sources
PubMed2001

Deletion of the acidic-rich domain of the IL-2Rbeta chain increases receptor-associated PI3K activity.

Interleukin-2 (IL-2) regulates the proliferation and homeostasis of lymphocytes through the coordinated activation of distinct signaling pathways. Deletion of the acidic-rich domain of the IL-2 receptor beta chain (IL-2Rbeta) prevents association of Src tyrosine kinases to the receptor, as well as IL-2-induced Akt activation. Cells bearing this deletion (BafbetaDeltaA) maintain full proliferation in response to IL-2 both in vivo and in vitro, suggesting that those pathways are dispensable for this important function of IL-2. In this study, we re-examined phosphatidylinositol-3 kinase (PI3K) activation in BafbetaDeltaA cells and found that, in BaF/3 IL-2RbetaDeltaA cells, deletion of the acidic domain induced constitutive activation of the receptor-associated PI3K activity. This, in turn, was responsible for the higher basal Akt activity observed in cells expressing this deletion. Based on these data, and since pharmacological abrogation of PI3K activity prevented IL-2-driven cell proliferation of BafbetaDeltaA cells, we conclude that the PI3K/Akt pathway is still functionally relevant in cells bearing this mutation. Moreover, we show that the PI3K-induced signals are, at least in part, responsible for c-myc expression. In conclusion, we have used this model to better identify those signals that are integral components of the molecular mechanisms responsible for IL-2-regulated cell proliferation.

Animals↗
PubMed1992

Helicobacter pylori infection in children: clinical, endoscopic, and histologic correlations.

We have assessed 270 consecutive patients (age range 0.8-20 years) referred for endoscopic study because of abdominal pain during 32 months. Helicobacter pylori (HP) was detected by culture in 91 cases (33.7%). HP colonization increased significantly with age (p less than 0.01). Nine patients less than 5 years of age were colonized by HP. A previous history of peptic ulcer disease in first-degree relatives was significantly more frequent in the HP-positive group (p less than 0.001). The frequency of HP positiveness as related to diagnosis was: normal, 3.3%; nonactive chronic gastritis, 100%; active chronic gastritis, 97.2%; gastric ulcer, 75%; and duodenal ulcer, 90.9% (p less than 0.001). Endoscopic nodular antritis was a frequent (67%) and specific finding; this presence was associated with that of lymphoid follicles in the histopathological study. Signs of histological activity were observed in 55.9% of the HP-positive patients. The histological colonization by HP was assessed semiquantitatively, and a significantly greater HP colonization score was observed in patients with signs of histological activity (p less than 0.001). A significant correlation was found between HP colonization score and histological score (rs = 0.574), with a significant association between the degree of HP colonization and the histologic categories (p less than 0.001). The present study suggests a pathogenic role of HP in the development of gastroduodenal disease in children.

Adolescent↗
PubMed1992

Platelet alpha 2-adrenoceptor density in pregnancy-induced hypertensive patients: effect of epidural analgesia.

OBJECTIVES: Although pregnancy induced hypertension (PIH) is an important and relatively common medical problem, its pathophysiology remains unresolved and the search for a biochemical marker that precedes the hemodynamic abnormalities of PIH continues. Since human platelets contain alpha 2-adrenoceptors, these receptors were measured in women with PIH to determine whether patients with PIH have alpha 2-adrenoceptor abnormalities that might cause or exacerbate the hypertensive process. The effect of epidural analgesia upon blood pressure and its relation to changes in platelet alpha 2-adrenoceptor density were also investigated. DESIGN: Biochemical measurements and radioligand binding assays in platelets were performed on 33 patients with the criteria for PIH and on 26 healthy pregnant women. RESULTS: Blood pressure was significantly elevated in hypertensive women when compared with normotensive pregnant women although, in this group, blood pressure returned to normal levels in response to epidural analgesia. In drug-free hypertensive patients, the specific binding of 3H-yohimbine to platelet membranes increased significantly compared with that in control pregnant subjects. In contrast, the dissociation constant was not significantly different in the two groups. Furthermore, alpha 2-adrenoceptor density in the group with PIH returned to normal levels in response to epidural analgesia. CONCLUSION: Our findings indicate that PIH is characterized by an exaggerated response of platelet alpha 2-adrenoceptor density to a rise in blood pressure and that this alteration could be significant in the pathogenesis of hypertension. Furthermore, human alpha 2-adrenoceptors undergo regulatory mechanisms similar to those recently described for adrenergic receptors in a variety of animal models.

Adult↗
PubMed1992

Identification of a nonframeshift 84-bp deletion in exon 13 of the cystic fibrosis gene.

Cystic fibrosis (CF) is the most frequent autosomal recessive inherited disorder in Caucasian populations. The disease is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. We have identified an 84-bp deletion in exon 13 of the CFTR gene, detected by DNA amplification and direct sequencing of 500 bp of the 5' end of exon 13. The deletion was in the maternal allele of a CF patient bearing the delta F508 deletion in the father's allele. The same 84-bp deletion could also be detected in the patient's mother. The deletion spanned from a four-A cluster in positions 1949-1952 to another four-A cluster in positions 2032-2035, including 84 bp which correspond to codons 607-634 (1949del84). The reported mutation would result in the loss of 28 amino acid residues of the R domain of the CFTR protein.

Alleles↗
PubMed1991

A malformed child with a recombinant chromosome 7, rec(7) dup p, derived from a maternal pericentric inversion inv(7)(p15q36).

We report a child with facial dysmorphic features, hypoplasia of the external genitalia, intestinal malrotation, congenital cardiac defect, and minor limb anomalies. Chromosome studies showed a recombinant chromosome 7, rec(7) dup p, resulting from a maternal pericentric inversion inv(7)(p15 q36). Thus, this child had partial trisomy 7p in addition to a small distal monosomy 7. The clinical findings are compared with those found in previous reports of trisomy 7p. Finally, some general principles for genetic counselling are discussed.

Abnormalities, Multiple↗
PubMed1990

Effect of taurine supplements on growth, fat absorption and bile acid on cystic fibrosis.

We have evaluated the effect of taurine supplementation nutritional status, steatorrhea and bile acid in twenty two Cystic Fibrosis patients. Weight increased in fifty per cent and height in forty eight per cent of them. Steatorrhea improved significantly in six patients of group II. Glycine/taurine ratio was reduced. Bile acid malabsorption improved only in the patients with high degree of steatorrhea. Serum bile acid was observed significantly elevated in both groups. This results suggest that taurine supplementation can be useful adjunct from of therapy in Cystic Fibrosis patients with fat malabsorption.

Adolescent↗
PubMed1989

[Incidence and management of surgical pathology in children with cystic fibrosis of the pancreas].

This report reviews 110 children of ages ranging from 2 months to 17 years, with a diagnosis of cystic fibrosis, and analyzes the surgical treatments they have undergone. In our series, meconium ileus shows an higher occurrence (20%) than the reported by the literature. No direct relationship could be established between the existence of meconium ileus and a more severe affectation of cystic fibrosis. Rectal prolapse occurred in 10% of the patients, and only 4% underwent surgical treatment. Three children with appendicitis developed a periappendiceal abscess due to delayed diagnosis and 2 other were operated upon for meconium ileus equivalent. From 7 patients with gastroesophageal reflux, 5 were treated non-operatively and 2 required corrective surgery. Fifty five patients out of the 110 (45%) underwent different surgical procedures.

Adolescent↗
PubMed1988

Severe combined immunodeficiency with T lymphocytes retaining functional activity.

Two cases of severe combined immunodeficiency (SCID) with normal numbers of T cells are reported. Studies of T-cell subsets showed an absence of TQ1+ lymphocytes and a very low percentage of CD4+ cells in Patient 2. Functional studies of T cells from this patient showed a normal suppressor activity. Patient 1 had normal percentages of T-cell subsets and his lymphocytes showed helper and suppressor activities but to a lesser degree than normal controls. Both cases stressed the heterogeneity of SCID in which T cells could be present and retain some of their functional activities.

Antibodies, Monoclonal↗
PubMed1987

[Vitamin E deficiency in cystic fibrosis].

Plasma vitamin E levels were measured by high performance liquid chromatography in 42 children with cystic fibrosis and were correlated with the following parameters: sex, age, time of follow-up, clinical evolution (Schwachman score), vitamin E/cholesterol and faecal fat excretion. All children in this study received oral alfa-tocoferol (50-100 mg daily) from the diagnosis. According to the vitamin E level patients were distributed in two groups. Group I: 27 patients (64.3%) with normal concentrations. Group II: 15 patients (35.7%) with decreases plasma levels but without clinical manifestations. Steatorrhea was present in all children except 4 patients from group I and one patient from group II. On the other hand, vitamin E/cholesterol was normal in 80% of patients with vitamin E deficiency (group II). We did not find any correlation between plasma vitamin E levels and the different clinical and biological parameters studied. Further studies should be carried out to throw more light on the mechanism underlying the pathogenesis of vitamin E deficiency in patients with cystic fibrosis.

Adolescent↗
PubMed1987

[Primary peptic ulcer in childhood: apropos of 16 cases].

We report a retrospective review of primary peptic ulcer disease in 16 children, 8 boys and 8 girls between 2 and 14 years of age, seen at our hospital over a 4 years and 4 months period. Endoscopy was realized in all children and revealed 7 duodenal ulcers (DU) and 11 gastric ulcers (GU) (two patients had both locations). At the initial diagnosis 5 patients were less than 6 years old with a ratio GU/DU of 4:1; in the other patients this ratio was 1:1. In children with duodenal ulcer 56.5% of them had positive family history. The commonest presenting symptoms were abdominal pain (87.5%) and acute gastrointestinal bleeding (68.7%). The follow-up period ranged from 2 to 52 months; in 13 cases follow-up was more than 1 year. Four patients (3 DU and 1 GU) older than 6 years recurred.

Adolescent↗
PubMed1985

[Desquamative interstitial pneumonia].

Authors describe a case of desquamative interstitial pneumonia in a seven month old boy. Initial manifestations were anorexia, feeding difficulties, retarded ponderal and progressive respiratory distress. Pathologic diagnosis was performed by open pulmonary biopsy. He was treated with steroids and followed a severe clinical course dying at 9 months of age. Etiopathogenesis, diagnosis and treatment as well as cases published in pediatric literature are reviewed.

Humans↗
PubMed1985

Pharmacokinetics and initial distribution of a new neuroleptic agent picobenzide (M-14012-4).

The pharmacokinetics of picobenzide was studied in 14 adult patients undergoing neuroleptoanalgesic sessions. The dose of picobenzide administered was 10 mg/kg by i.v. injection. The pharmacokinetic parameters obtained revealed a good distribution capacity with an average value of the apparent distribution volume at steady state of 28.29 +/- 4.98 1. The drug was also seen to be eliminated rapidly from the organism with an average value of the serum half-life of 2.05 +/- 0.42 h. The determination of the initial distribution kinetics of picobenzide shows that the use of a conventional kinetic model induces an overestimation of the initial distribution volume in turn caused by an underestimation of the initial serum concentration.

Adult↗
PubMedDate not supplied

Time-frequency analysis of the heart rate variability during the Valsalva manoeuvre.

We present an analysis of the heart rate variability during the Valsalva manoeuvre. The more frequently used time-frequency distributions were applied in order to analyse the dynamical behaviour of several spectral indexes during the manoeuvre. The influence of the branches of the autonomous system can be predicted following the evolution of the studied indexes. The exponential time-frequency distribution showed the best results in the graphical representation, as well as in the indexes calculation. The total power, the low-to-high frequency ratio and the fractal dimension were analysed throughout the different phases of the manoeuvre and a representative model of these parameters' evolution was proposed.

Adult↗
PubMedDate not supplied

Correlation among Poincaré plot indexes and time and frequency domain measures of heart rate variability.

PRIMARY OBJECTIVE: In order to corroborate the rported performance advantage of Poincaré plot indexes as autonomic activity markers, the correlation among these indexes and those computed from the time and frequency domains were obtained. METHODS AND PROCEDURES: Starting from the RR series derived from the ECG of 21 healthy volunteers during five manoeuvres, longitudinal (L), transverse (T) axis, and autocorrelation (r) from Poincaré plots, rMSSD and standard deviation (SD) in the temporal domain, and frequency domain indexes were computed. MAIN OUTCOMES AND RESULTS: Poincaré plot indexes were correlated in a better way with the time indexes, rather than the spectral measures. A strong correlation (0.997) between L and SD was observed, while an underlying mathematical relationship was established for T vs rMSSD. CONCLUSIONS: Poincaré plot indexes may be considered as equivalent or surrogates of the temporal ones, and they do not have a better performance as autonomic markers.

Adult↗
PubMedDate not supplied

Differences in foetal heart rate variability from phonocardiography and abdominal electrocardiography.

The agreement of the phonocardiographic method to provide foetal heart rate variability (FHRV) indices equivalent to those derived from abdominal electrocardiography was tested. 15 pregnant women were recruited in order to obtain antepartum foetal phonocardiograms and abdominal electrocardiograms three minutes long. From the respective sound (SS) and electric (RR) time series, typical temporal and spectral indices of FHRV were computed and compared. Means of the SS and RR intervals were not significant (P> 0.05) and these showed a correlation r=0.98. However, the temporal indices, P(TOT), HF and LF/HF presented differences (P< 0.05), since SS values were higher. Spectral coherence decreased below 0.5 for frequencies above 0.28+ 0.07 Hz, where bands resembling maternal and foetal breathing movements were noted. Particularly above 0.28Hz, temporal and spectral FHRV indices derived from phonocardiography and electrocardiography show differences. Quality of the signal, processing techniques, and maternal and foetal respiratory factors could account to explain these.

Adult↗