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Biomedical subjects

J Verdú

Publications and source records attributed to J Verdú.

At least 19 recordsLinked to original sources
PubMed2005

[Study of renal function and compensatory changes in children with single kidney].

INTRODUCTION: It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. MATERIAL AND METHODS: We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function -group I- or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. RESULTS: Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. CONCLUSIONS: Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies.

Child↗
PubMed2004

Electronic g factor of hydrogenlike oxygen 16O7+.

We present an experimental value for the g factor of the electron bound in hydrogenlike oxygen, which is found to be g(expt)=2.000 047 025 4 (15)(44). The experiment was performed on a single 16O7+ ion stored in a Penning trap. For the first time, the expected line shape of the g-factor resonance is calculated which is essential for minimizing the systematic uncertainties. The measurement agrees within 1.1 sigma with the predicted theoretical value g(theory)=2.000 047 020 2 (6). It represents a stringent test of bound-state quantum electrodynamics to a 0.25% level. Assuming the validity of the underlying theory, a value for the electron mass is obtained: m(e)=0.000 548 579 909 6 (4) u. This value agrees with our earlier determination on and allows a combination of both values which is about 4 times more precise than the currently accepted one.

Journal Article↗
PubMed2004

[MIBI and parathyroid gland function in secondary hyperparathyroidism].

The role of the double phase parathyroid scintigraphy with MIBI in the primary hyperparathyroidism has been well studied. The present work analyzes the benefit of this image technique in the diagnosis and therapeutic approach to uremia associated hyperparathyroidism. We studied 18 dialysis patients with clinical and analytical data of hyperparathyroidism. All of them were receiving treatment with i.v. vitamin D. We carried out two scintigraphic studies, the first under basal conditions (without changes in treatment) and the second one, a week later after the stimulation of the parathyroid gland through the cessation of the treatment with vitamin D and phosphorus binders, and the use of a low-calcium dialysate. In the basal study, fourteen patients had a positive uptake test in at least one of the four glands. These patients had significantly higher PTHi levels than those with a negative scintigraphic study. After the stimulation test, we found a statistically significative rise in PHTi (644 vs 979 p < 0.001) and phosphorus levels (5.8 vs 7.3; p < 0.01), a slight fall in calcium levels (p = NS) and a statistically significative increment in the score of scintigraphic captation (5.5 +/- 4.5 vs 6.8 +/- 5; p < 0.05). We found a statistically significative correlation between the PTHi level and the score of scintigraphic uptake, in the basal study (r = 0.6, p < 0.01) and after stimulation (r = 0.6, p < 0.01). The only variable associated with the scintigraphic uptake was PTHi, justifying 31.1% of the variance in the first study and 32.7% in the second. In conclusion, the MIBI scintigraphic is a useful exploration in the uremic patient with hyperparathyroidism, as it predicts the functional state of the parathyroid glands according to uptake intensity. The stimulation test could be useful in planning therapy, but some of its characteristics need to be established, such as the precise time to reach the maximum level of parathyroid stimulation.

Acetates↗
PubMed2001

The translational inhibitor 4E-BP is an effector of PI(3)K/Akt signalling and cell growth in Drosophila.

The initiation factor 4E for eukaryotic translation (eIF4E) binds the messenger RNA 5'-cap structure and is important in the regulation of protein synthesis. Mammalian eIF4E activity is inhibited when the initiation factor binds to the translational repressors, the 4E-binding proteins (4E-BPS). Here we show that the Drosophila melanogaster 4E-BP (d4E-BP) is a downstream target of the phosphatidylinositol-3-OH kinase (PI(3)K) signal-transduction cascade, which affects the interaction of d4E-BP with eIF4E. Ectopic expression of a highly active d4E-BP mutant in wing-imaginal discs causes a reduction of wing size, brought about by a decrease in cell size and number. A marked reduction in cell size was also observed in post-mitotic cells. Expression of d4E-BP in the eye and wing together with PI(3)K or dAkt1, the serine/threonine kinase downstream of PI(3)K, resulted in suppression of the growth phenotype elicited by these kinases. Our results support a role for d4E-BP as an effector of cell growth.

Amino Acid Sequence↗
PubMed2000

High-accuracy measurement of the magnetic moment anomaly of the electron bound in hydrogenlike carbon.

We present a new experimental value for the magnetic moment of the electron bound in hydrogenlike carbon (12C5+): g(exp) = 2.001 041 596 (5). This is the most precise determination of an atomic g(J) factor so far. The experiment was carried out on a single 12C5+ ion stored in a Penning trap. The high accuracy was made possible by spatially separating the induction of spin flips and the analysis of the spin direction. The current theoretical value amounts to g(th) = 2.001 041 591 (7). Together experiment and theory test the bound-state QED contributions to the g(J) factor of a bound electron to a precision of 1%.

Journal Article↗
PubMed1999

Independent regulation of adherens and tight junctions by tyrosine phosphorylation in Caco-2 cells.

To study the role of tyrosine phosphorylation in the control of intercellular adhesion of intestinal cells, we have generated several clones of Caco-2 cells that express high levels of pp60v-src only after addition of butyrate. Expression of this oncogene in cells 5 days after confluence induced beta-catenin and p120-ctn tyrosine phosphorylation, redistribution of E-cadherin to the cytosol and disassembly of adherens junctions. However, tight junctions of Caco-2 cells at 5 days after confluence were not altered by expression of pp60v-src. Similar results were obtained when Caco-2 cells were incubated with phosphotyrosine phosphatase inhibitor orthovanadate. Although addition of this compound to postconfluent cells disrupt adherens junctions, tight junctions remain unaltered, as determined measuring monolayer permeability to mannitol or hyperphosphorylation of Triton-insoluble occludin. Modifications in tight junction permeability of Caco-2 were only observed at high concentrations of orthovanadate (1 mM). Interestingly, this tyrosine phosphorylation-refractory state was achieved after confluence since early postconfluent cells (day 2) showed a limited but significant response to low doses of orthovanadate. These results suggest that tight junctions of differentiated Caco-2 cells are uncoupled from adherens junctions and are insensitive to regulation by tyrosine phosphorylation.

Caco-2 Cells↗
PubMed1999

[Abdominal scintigraphy with 99MTc-HMPAO-labelled leukocytes. Utility of the quantification in the evaluation of the inflammatory activity of Crohn's disease and ulcerative colitis].

We aimed to determine the activity of Crohn's Disease (CD) and Ulcerative Colitis (UC) with this radiotracer and to compare it with the normal clinical indexes. 32 patients with CD (19 women) and 18 with UC (13 women) were studied and a sequential abdominal 99mTc-HMPAO-label leukocyte scintigraphy was performed after evaluating the activity clinical scales indexes (Harvey's for CD and Lictiger for UC). Quantification was performed to obtain intestinal activity indexes in regards to intestinal uptake with background, bone marrow, liver and spleen, comparing them with the clinical indexes. In CD, all scintigraphic indexes showed a significant correlation (p < 0.001) with clinical activity. The best results were obtained with gut/background (r: 0.73) and gut/bone marrow (r: 0.72). In UC, we obtain a lower correlation between clinical and scintigraphic indexes. Significant correlations (p < 0.05) were only found with the gut/background (r: 0.52) and gut/bone marrow growth indexes (r: 0.58). The others showed no correlation. In conclusion, IBD activity estimated with 99mTc-WBC and scintigraphy indexes showed moderate correlation with clinical scales. However, the information of the scintigraphy was very useful in the management of these patients.

Adult↗
PubMed1998

Protein kinase C-alpha activity inversely modulates invasion and growth of intestinal cells.

The phorbol ester phorbol 12-myristate 13-acetate induces remarkable phenotypic changes in intestinal HT-29 M6 cells; these changes consist of loss of homotypic adhesion and inactivation of E-cadherin. In parallel, cell growth is retarded. We have transfected HT-29 M6 cells with an activated form of the conventional protein kinase Calpha (cPK-Calpha). Expression of this isoform induced the acquisition of a scattered phenotype, similar to that adopted by cells after addition of phorbol 12-myristate 13-acetate, with very low cell-to-cell aggregation and undetectable levels of functional E-cadherin. These cell clones were highly motile and rapidly invaded embryonic chick heart fragments. Furthermore, cells expressing activated-cPK-Calpha showed decreased proliferation in comparison to control clones. We have also studied how these two apparently antagonistic changes affect the tumorigenic ability of HT-29 M6 cells. When the different cell clones were xenografted into athymic mice, the effect on cell growth seemed to predominate. Expression of activated-cPK-Calpha significantly reduced the size of the tumors; the cells with the highest level of expression did not even form subcutaneous tumors. Besides their smaller size, the morphology of these tumors was clearly different from those originated by HT-29 M6 cells, and they could be defined as infiltrative on anatomo-pathological basis. These results indicate that cPK-Calpha controls both cell-to-cell adhesion and proliferation of intestinal cells.

Animals↗
PubMed1998

[Reversible hyperparathyroid metabolic osteopathy secondary to parathyroid carcinoma].

Parathyroid carcinoma is a rare cause of hyperparathyroidism and metabolic osteopathy. The authors report a patient with parathyroid carcinoma who underwent 99mTc-Sestamibi parathyroid and 99mTc-MDP bone scanning. These techniques showed the parathyroid lesion and typical features of severe metabolic osteopathy respectively. The bone scan performed at only four months after surgery showed near complete resolution.

Bone Diseases, Metabolic↗
PubMed1997

[Ulcerative colitis and colonic angiodysplasia associated with a lower digestive hemorrhage. Their diagnosis by 99-technetium-labelled red blood cells].

We describe a case of a patient with previously diagnosed of ulcerative colitis, who was admitted to the hospital because of rectal bleeding and abdominal pain. A mild active colitis was reported by colonoscopy with biopsy. Rectal bleeding relapsed, and an arteriovenous malformation in the transverse colon compatible with angiodysplasia was located by early vascular scintigraphy with 99m-technetium-labeled red blood cells. This finding was confirmed by selective arteriography. Four months after hemicolectomy, the patient is free of rectal bleedings. Labeled red blood cell scintigraphy may be useful to differential diagnosis of lower digestive hemorrhage.

Aged↗
PubMed1997

[Cerebral blood flow study using SPECT in patients with memory disorders].

INTRODUCTION: Global amnesia (AG) is a dysfunction of memory, in which there is a sudden incapacity to remember recent events and assimilate new information. The aetiology is currently under discussion. The main hypotheses under consideration are an ischemic mechanism and an epileptic mechanism. OBJECTIVE: To study the cerebral blood flow in patients with temporary global amnesia (AGT) or permanent global amnesia (AGP) using functional neuroimaging techniques. MATERIAL AND METHODS: Four patients were studied. Two had severe alterations of fixation memory which had been present for months. The other two had a sudden loss of recent memory, although space-person orientation and immediate memory remained normal. In all cases the cerebral blood flow (FSC), was assessed by single photon emission tomography (SPECT), using Tc-HMPAO as the radio tracer. RESULTS: We describe 4 patients, 2 men and 2 women aged between 42 and 64.2 with AGT and the others with AGP. On SPECT there was temporal hypoperfusion in all 4 patients. In 2 cases there was associated parietal hypoperfusion and in 1 case there was frontal hypoperfusion. CONCLUSIONS: These findings suggest that AGT and AGP are of vascular origin and that SPECT is a useful diagnostic technique in patients with AG.

Adult↗
PubMed1997

[Recurrent rectorrhagia caused by angiodysplasia of the colon localized exclusively by scintigraphy with Tc-99m red blood cells].

A case of angiodysplasia of the colon with clinical manifestation of massive rectal bleeding is presented. The activity and the severity of the life-threatening bleeding episode led to emergency exploratory laparotomy with intraoperative colonoscopy which was not diagnostic. Three years later, following multiple recurrent bleeding episodes and non diagnostic explorations, the localization of the hemorrhage was obtained by abdominal scintigraphy with 99mTc-red blood cells. Surgical removal of the affected area achieved definitive cure.

Angiodysplasia↗
PubMed1995

Persistent truncus arteriosus in a diprosopic newborn calf.

A newborn diprosopic female calf had a partially duplicated head with two faces each exhibiting a mouth, a snout, an anomalous incomplete mandible, two eyes and a lateral ear. A single ear with two small auditory canals was present on the midline between the two medial eyes. A type 1 persistent truncus arteriosus and hypoplasia of the thoracic portion of thymus were the most outstanding extracranial defects. In the heart, a persistent foramen secundum and a large patent foramen ovale allowed communication between the right and left atria. In the right ventricle, the small conus arteriosus was separated in part from the inflow tract by an anomalous 'septomarginal muscular septum'. An interventricular septal defect was also present. A large undivided truncus arteriosus, exhibiting a tricuspid truncal valve at its origin, arose for the most part from the conus arteriosus of the right ventricle. The truncus gave rise to the brachiocephalic trunk, the aortic arch, a small pulmonary trunk, from which the left and right pulmonary arteries emerged, and two coronary arteries. The etiology and pathogenetic mechanisms implicated in the appearance of persistent truncus arteriosus are reviewed. It is suggested that a deficit or insufficiency in the cranial neural crest may play a role in the pathogenetic mechanisms leading to the production of persistent truncus arteriosus and related defects in cephalic duplications.

Animals↗
PubMed1992

Morphology of a dicephalic cat.

A detailed anatomical study of a dicephalic iniodymic monosomic cat in conjunction with the morphogenetical implications of the observed anomalies is presented. The animal exhibited two heads joined at the level of an anomalous medial exoccipital bone. Two brains and two foramina magna were present. The vertebral column was single but the cranial cervical vertebrae (C2 to C5) had doubled bodies. Cervical rachischisis with myeloschisis were associated defects. Two nasopharyngeal and oropharyngeal cavities converged caudally into a single laryngopharynx. The esophagus, larynx and trachea were single. Duplication of the tongue and hyoid apparatus was present. Palatoschisis affected both oral cavities. Hypoplasia of the anatomical structures in the medial aspects of both heads was observed. Microphthalmia was also observed in both medial eyes. Comparative aspects of the morphology, causative agents, and mechanisms and anomalous morphogenesis of anterior duplications are reviewed and discussed.

Abnormalities, Multiple↗