401
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Cannon D, Low JN, Cobo J, Molina S, Nogueras M, Sánchez A, Glidewell C. Methyl 7-hydroxy-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropteridine-6-carboxylate–dimethyl sulfoxide (1/1) forms chains containing O—H...O and C—H...O hydrogen bonds and aromatic π–π-stacking interactions. Acta Crystallogr C 2001; 57:608-10. [PMID: 11353267 DOI: 10.1107/s0108270101003250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2001] [Accepted: 02/16/2001] [Indexed: 11/11/2022] Open
Abstract
In the title compound, C11H12N4O5-C2H6OS, the molecular components are linked by a short hydrogen bond with dimensions O...O 2.517 (2) A and O-H...O 168 degrees. Paired C-H...O hydrogen bonds [C...O 3.362 (2) and 3.382 (2) A; C-H...O 157 and 140 degrees] generate cyclic centrosymmetric four-component aggregates reinforced by aromatic pi-pi-stacking interactions, and further C-H...O hydrogen bonds [C.O 3.472 (3) and 3.521 (2) A; C-H...O 156 and 157 degrees] link these aggregates into chains.
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402
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Amat P, Blázquez JL, Peláez B, Sánchez A, Amat-Peral H, Amat-Peral P, Pastor FE. Ultrastructural features of rat arcuate nucleus neurons during pregnancy. ITALIAN JOURNAL OF ANATOMY AND EMBRYOLOGY = ARCHIVIO ITALIANO DI ANATOMIA ED EMBRIOLOGIA 2001; 103:311-24. [PMID: 11315963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The ultrastructure of the arcuate nucleus was studied in Sprague-Dawley rats sacrificed at 7, 10, 14 and 20 days of gestation, using conventional techniques of electron microscopy. Our results revealed an increase in granular filamentous bodies and whorled bodies that appear in arcuate neurons as early as on the 7th day of gestation. A further increase of these structures was showed by day 10 and, especially, by day 14. In the arcuate nucleus of rats sacrificed on day 14 of gestation, some compact, homogeneous and very large (up to 5.5 microm diameter) granular filamentous bodies may be seen both in neuronal bodies and in dendrites. In some neurons of arcuate nucleus of these gestational phases (days 10 and 14), besides the whorled bodies dense-core vesicles were found. Neurons with cilia were occasionally observed, and some neuronal bodies were in close apposition and joined by intercellular bridges. Open synapses were observed during all the gestational phases. The smallest number of these synapses was seen in the arcuate nucleus of rats sacrificed on day 14 of gestation.
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403
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Sancho JM, Sánchez A. Selection, shape, and relaxation of fronts: a numerical study of the effects of inertia. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:056608. [PMID: 11415032 DOI: 10.1103/physreve.63.056608] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2000] [Indexed: 05/23/2023]
Abstract
We study the problem of front propagation in the presence of inertia. We extend the analytical approach for the overdamped problem to this case, and present numerical results to support our theoretical predictions. Specifically, we conclude that the velocity and shape selection problem can still be described in terms of the metastable, nonlinear, and linear overdamped regimes. We study the characteristic relaxation dynamics of these three regimes, and the existence of degenerate ("quenched") solutions.
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404
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Serra E, Ars E, Ravella A, Sánchez A, Puig S, Rosenbaum T, Estivill X, Lázaro C. Somatic NF1 mutational spectrum in benign neurofibromas: mRNA splice defects are common among point mutations. Hum Genet 2001; 108:416-29. [PMID: 11409870 DOI: 10.1007/s004390100514] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neurofibromas, benign tumors that originate from the peripheral nerve sheath, are a hallmark of neurofibromatosis type 1 (NF1). Although loss of heterozygosity (LOH) is a common phenomenon in this neoplasia, it only accounts for part of the somatic NF1 mutations found. Somatic point mutations or the presence of "two hits" in the NF1 gene have only been reported for a few neurofibromas. The large size of the NF1 gene together with the multicellular composition of these tumors has greatly hampered their molecular characterization. Here, we present the somatic NF1 mutational analysis of the whole set of neurofibromas studied by our group and consisting in 126 tumors derived from 32 NF1 patients. We report the identification of 45 independent somatic NF1 mutations, 20 of which are reported for the first time. Different types of point mutations together with LOH affecting the NF1 gene and its surrounding region or extending along the 17q arm have been found. Among point mutations, those affecting the correct splicing of the NF1 gene are common, coinciding with results reported on germline NF1 mutations. In most cases, we have been able to confirm that both copies of the NF1 gene are inactivated. We have also found that both somatic and germline mutations can be expressed at the RNA level in the neoplastic cells. Furthermore, we have observed that the study of more than one tumor derived from the same patient is useful for the identification of the germline mutation. Finally, we have noticed that the culture of neurofibromas and their fibroblast clearance facilitates LOH detection in cases in which it is difficult to determine.
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405
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Abstract
The effectiveness of microsatellites in parentage testing and individual identification has been proven in many species, including dogs. However, the use of these markers has not been extended to control for pedigrees in large populations of closely related animals. We have analyzed polymorphism in a set of 10 microsatellites over three generations of 360 pedigree rottweilers. Results were compared with two pure-bred populations of unrelated animals and with one population constituted by unrelated dogs of mixed breeds to measure polymorphism variation. We optimized this set of microsatellites to be analyzed by a semiautomated capillary electrophoresis method after amplification in two multiplex polymerase chain reactions (PCRs). The mean polymorphism information content (PIC) value in the rottweiler pedigree is 0.401 and the combined paternity exclusion probability (CPE) is 95.6%. These values are similar to those obtained in pure-bred populations of unrelated animals, and although polymorphism is reduced in relation to the pool population, we solved all paternity exclusions. In only a few cases did we have to use two additional microsatellites to solve individual identification of full-sib dogs.
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406
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Cuadrado P, González-Nogal AM, Sánchez A. Regiospecific and stereoselective synthesis of functionalized and differently metalated alkenes by silyl- or stannylcupration of metalated acetylenes. J Org Chem 2001; 66:1961-5. [PMID: 11300888 DOI: 10.1021/jo0010983] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Differently metalated vinylcuprate intermediates resulting from silyl- or stannylcupration of silyl- and tin-containing acetylenes reacted with a range of electrophiles, including chlorosilanes and chlorostannanes, affording regio- and stereodefined differently metalated vic and gem silyl- and tin-trisubstituted alkenes. Some of these functionalized polymetalated olefins are interesting synthons in organic chemistry.
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407
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Abstract
The use of feathers in veterinary clinical practice simplifies the sampling of avian genomic DNA, especially when blood extraction is difficult because of the age or the size of the bird. A rapid and accurate protocol was used to isolate high-quality genomic DNA from feathers. The technique includes a lysis step of the feather quill, which differs in temperature and time of incubation depending on the feather size. Purification of genomic DNA is performed with phenol: chloroform: isoamyl alcohol extraction and ethanol precipitation. This protocol consistently provided significant amounts of high-quality genomic DNA from more than 800 birds belonging to 120 different species. Genomic DNA isolated with this method was used for Southern blotting and also in several polymerase chain reaction systems devoted to sex determination and paternity testing.
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408
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Pueyo M, Honrubia FM, Sánchez A, Pablo LE. [Ciliary ablation with diode laser. Long-term study]. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2001; 76:165-8. [PMID: 11283782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
PURPOSE The effects of contact transscleral cyclophotocoagulation with diode laser for refractory glaucoma have been analyzed. METHODS A diode laser system was used to treat twenty one eyes with refractory glaucoma. The mean follow-up was 22.24+/-9.89 months. All the eyes were treated with 15 laser spots placed over 270 degrees, 1 mm posterior to the limbus, using 3.0 J (1.0 W X 3.0 sg). RESULTS The mean preoperative intraocular pressure was 40.95+/-11.76 mmHg and the mean intraocular pressure at the end of the follow-up was 24.28+/-7.80 mmHg (p<0.5). An intraocular pressure below 21 mmHg was obtained in 10 out the 13 eyes (76.92%). Six of the 8 painful eyes had pain relief (75.00%). The principal complications included a decreased visual acuity in 5 eyes and chronic uveitis in 2 patients. CONCLUSIONS These results suggest that semiconductor diode transscleral cyclophotocoagulation can be used successfully to reduce intraocular pressure in the treatment of refractory glaucoma.
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409
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Herrera B, Alvarez AM, Sánchez A, Fernández M, Roncero C, Benito M, Fabregat I. Reactive oxygen species (ROS) mediates the mitochondrial-dependent apoptosis induced by transforming growth factor (beta) in fetal hepatocytes. FASEB J 2001; 15:741-51. [PMID: 11259392 DOI: 10.1096/fj.00-0267com] [Citation(s) in RCA: 239] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Treatment of fetal rat hepatocytes with transforming growth factor beta (TGF-beta) is followed by apoptotic cell death. Analysis of radical oxygen species (ROS) content and mitochondrial transmembrane potential (Deltapsim), using specific fluorescent probes in FACScan and confocal microscopy, showed that TGF-beta mediates ROS production that precedes the loss of Deltapsim, the release of cytochrome c, and the activation of caspase 3. TGF-beta induces a decrease in the protein and mRNA levels of bcl-xL, an antiapoptotic member of the Bcl-2 family. In contrast, there is no change in the expression and/or translocation of Bax, a proapoptotic member of the same family. EGF maintains Bcl-xL, preventing Deltapsim collapse and release of cytochrome c. The presence of radical scavengers blocks the decrease in bcl-xL levels, Deltapsim collapse, cytochrome c release, and activation of caspase 3; in contrast, the presence of glutathione synthesis inhibitors such as BSO accentuated the effect. The incubation of fetal hepatocytes in the presence of ter-butyl-hydroperoxide alone produces a decrease in bcl-xL. These results indicate that during the apoptosis mediated by TGF-beta in fetal hepatocytes, ROS may be responsible for the decrease in bcl-xL mRNA levels that precedes the loss of Deltapsim, the release of cytochrome c, and the activation of caspase 3, culminating in cell death.
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410
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Casas JS, Martínez EG, Jorge ML, Russo U, Sánchez A, González AS, Seoane R, Sordo J. Diethyl- and dibutyltin dihalide complexes of 1-methyl-2(3H)-imidazolinethione: synthesis, structure and antibacterial activity. Appl Organomet Chem 2001. [DOI: 10.1002/aoc.124] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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411
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Alvarez J, del Barrio R, Arias J, Vázquez S, Sánchez A, Iglesias J, Barra C, Ibarguren C. Non-heart-beating donors: estimated actual potential. Transplant Proc 2001; 33:1101-3. [PMID: 11267209 DOI: 10.1016/s0041-1345(00)02434-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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412
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Badenas C, Castellví-Bel S, Volpini V, Jiménez D, Sánchez A, Estivill X, Milà M. Linkage analysis in Spanish families with nonspecific X-linked mental retardation: Significant linkage at Xq13-q21. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 98:343-7. [PMID: 11170079 DOI: 10.1002/1096-8628(20010201)98:4<343::aid-ajmg1107>3.0.co;2-v] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mental retardation (MR) is a genetically heterogeneous, clinically variable condition. Many cases of MR are linked to the X chromosome. The aim of this study was to identify candidate loci for nonspecific MR in Spanish samples. We selected seven families with nonspecific MR and a pattern of inheritance compatible with an X-linked disorder and a group of 26 sib pairs of mentally retarded individuals. We performed linkage analysis with a panel of 15 markers evenly distributed along the X chromosome. The study showed linkage to marker DXS8076, located in Xq21.1, by the lod score method (z = 2.11 at straight theta = 0.155) and the nonparametric extended relative pair analysis method (chi(2) = 5.32; P < 0.03). Genetic heterogeneity was found, with an estimated 75% of the families linked at recombination fraction straight theta = 0.10 to the DXS8076 locus (chi(2) = 9.51; P < 0.009). Xq13-q21 is one of the critical regions for X-linked MR previously reported, and our study supports the idea that this region may contain a locus for MR in Spanish patients.
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413
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Madrid AH, Ortega J, Rebollo JG, Manzano JG, Segovia JG, Sánchez A, Peña G, Moro C. Lack of efficacy of atenolol for the prevention of neurally mediated syncope in a highly symptomatic population: a prospective, double-blind, randomized and placebo-controlled study. J Am Coll Cardiol 2001; 37:554-9. [PMID: 11216978 DOI: 10.1016/s0735-1097(00)01155-4] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVES This study was designed to evaluate the efficacy of atenolol for the long-term management of patients with vasovagal syncope. The primary hypothesis was that atenolol is not superior to placebo for the treatment of vasovagal syncope. BACKGROUND There is no definitive well-controlled analysis of the efficacy of beta-adrenergic blocking agents in patients with recurrent vasovagal syncope. METHODS This is a prospective, randomized, double-blind, placebo-controlled study. Fifty patients with recurrent vasovagal syncope were included (at least two episodes in the last year). A baseline tilt test was performed. Twenty patients (40%) had a positive tilt test. Intravenous atenolol prevented a second positive tilt in five patients. The patients were randomized to receive either atenolol or a placebo (26 patients atenolol 50 mg/day, 24 patients placebo). The follow-up procedure lasted one year. The primary end point of the study was the time to first recurrence of syncope. RESULTS In the intention-to-treat analysis, the group treated with atenolol had a similar number of patients with recurrent syncopal episodes as the placebo group. The Kaplan-Meier actuarial estimates of time to first syncopal recurrence showed that the probability of remaining free of syncope drops similarly in both groups and that there was no statistical difference between both curves (patients treated with atenolol vs. the placebo) with a log-rank test p value of 0.4517. CONCLUSIONS The recurrence of neurocardiogenic syncope in highly symptomatic patients treated with atenolol is similar to that of patients treated with placebo.
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414
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Abstract
Bochdalek's hernia is a congenital hernia of the diaphragm, which is manifested in the early years of life. Its diagnosis is difficult and is based on barium studies. We present an adult patient with Bochdalek's hernia who exhibited a gastric volvulus. The patient had a history of intermittent abdominal pains. In this article, we analyze the diagnostic and therapeutic procedures, laying special emphasis on the importance of early diagnosis in the prevention of complications.
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415
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Bujanda L, Iriondo C, Muñoz C, Etxezarraga C, Ramírez MM, Ramos F, Sánchez A. Squamous metaplasia of the rectum and sigmoid colon. Gastrointest Endosc 2001; 53:255-6. [PMID: 11174313 DOI: 10.1067/mge.2001.110916] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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416
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Cascón A, Talavera P, Díez L, Sánchez A, Torres A, Balibrea J. Neuroma traumático de la vía biliar asociado a hepatolitiasis como causa de ictericia obstructiva: a propósito de un caso. Cir Esp 2001. [DOI: 10.1016/s0009-739x(01)71816-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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417
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Abstract
Pyomyositis is most commonly caused by Staphylococcus aureus. A 25-month-old child developed infection of the biceps brachialis muscle caused by Streptococcus pneumoniae. The child had no underlying immune or anatomic defect.
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418
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Pascual J, García Navarrete E, Escosa Bagó M, Sánchez A, Ramón S, Cajal, Navarro A, Sola R. 2. Epilepsia fármaco-resistente en lesiones cerebrales de tipo quirúrgico: tratamiento basado en un protocolo de estudio del complejo lesivo epileptógeno. Neurocirugia (Astur) 2001. [DOI: 10.1016/s1130-1473(01)70755-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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419
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Urculo E, Aranzadi M, Alfaro R, Arrazola M, Astudillo E, Bollar A, Navajas B, Ramos E, Rejas G, Sánchez A, Zapirain J, Rúiz I, San Vicente M. 5. Valoración de la autopsia en neurocirugía. Neurocirugia (Astur) 2001. [DOI: 10.1016/s1130-1473(01)70802-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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420
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Valls C, Andía E, Sánchez A, Gumà A, Figueras J, Torras J, Serrano T. Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT. Radiology 2001; 218:55-60. [PMID: 11152779 DOI: 10.1148/radiology.218.1.r01dc1155] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To prospectively evaluate helical computed tomography (CT) in the preoperative detection of hepatic metastases and assessment of resectability with surgical, intraoperative ultrasonographic (US), and histopathologic correlation. MATERIALS AND METHODS Between October 1995 and December 1998, preoperative staging with helical CT (5-mm collimation; reconstruction interval, 5 mm) was performed in 157 patients with hepatic metastases. Iodinated contrast material was injected intravenously (160-170 mL; rate, 2.5-3.0 mL/sec); acquisition began at 60-70 seconds. Four radiologists prospectively assessed the metastatic involvement of the liver by indicating the number and location of the lesions; resection was indicated in 113 patients (119 instances). Helical CT findings were correlated with pathologic and surgical findings on a lesion-by-lesion basis. RESULTS Intraoperative US, palpation, and histopathologic examination revealed 290 liver metastases; helical CT correctly depicted 247. Helical CT results were the following: overall detection rate, 85.1% (95% CI: 80.8%, 89.3%); positive predictive value, 96.1% (95% CI: 92.9%, 98.1%); and false-positive rate, 3.9% (10 of 257 findings; 95% CI: 1.9%, 7.1%). False-positive findings were related to hemangioendothelioma, hemangioma, hepatic peliosis, biliary adenoma, centrilobar hemorrhage, biliary hamartoma, periportal fibrosis, and normal liver parenchyma. Curative resection was performed in 112 instances with a resectability rate of 94.1%. Four-year patient survival rate was 58.6%. CONCLUSION Helical CT is a noninvasive, reliable, and accurate technique for imaging the liver and should be considered as the standard preoperative work-up of hepatic metastases from colorectal cancer.
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421
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Garagorri JM, Rodríguez G, Ros L, Sánchez A. Early detection of impaired glucose tolerance in patients with cystic fibrosis and predisposition factors. J Pediatr Endocrinol Metab 2001; 14:53-60. [PMID: 11220706 DOI: 10.1515/jpem.2001.14.1.53] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
INTRODUCTION The number of patients with glucose tolerance alterations associated with cystic fibrosis (CF) has increased, probably due to the greater survival rate among sufferers of this disease. We studied impaired glucose tolerance (IGT) in patients with CF and investigated whether its appearance has any relationship with age, sex, genetic mutation and/or the degree of clinical involvement. We assessed the parameters that might allow early detection. PATIENTS AND METHODS In 28 patients with CF (14 M, 14 F; aged 22 months to 18 years), sex, genetic mutation, nutritional status and the degree of pancreatic and pulmonary involvement were recorded. The metabolic study included glycosylated hemoglobin (HbA1c) determination, oral glucose tolerance test (OGTT) and intravenous glucose tolerance tests (IVGTT). RESULTS In the patients with CF, 35.71% showed impaired glucose tolerance (IGT) and 3.57% had diabetes mellitus. The patients with IGT and CF were 3.2 years older than those with normal glucose tolerance (NGT; p<0.05), but no significant differences were found regarding sex, anthropometric measurements, percentage of pulmonary gammagraphic involvement, Shwachman-Kulczycki test or HbA1c. In the OGTT, the patients homozygous for the deltaF508 mutation had higher blood glucose values than the heterozygous group (p=0.03), but these values were not higher than those in patients with other mutations. During the OGTT, blood insulin values at 30' were reduced in patients with IGT compared to patients with NGT (p<0.02) and the insulin peak occurred at 100.9+/-24.3 min compared to 65.3+/-21.8, respectively (p<0.05). In the IVGTT, 82.14% of the patients had reduced insulin levels at 1 and 3 min (I1'+3'). No differences in the blood glucose levels during the OGTT were found between patients with normal I1'+3' values and patients with reduced values. CONCLUSIONS A high percentage of patients with CF also present with IGT. This increases with age and is more common among patients homozygous for the deltaF508 mutation and is not related to clinical status. Alterations in the kinetics of insulin secretion play an important role in the appearance of IGT and CF. We suggest that the OGTT is a more sensitive method than IVGTT for identifying early alterations in CF-related diabetes mellitus.
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García Navarrete E, Pascual J, Sola R, Sánchez A, Escosa M. 1. Epilepsia del lóbulo temporal. Resultados quirúrgicos tras un seguimiento mínimo de dos años. Neurocirugia (Astur) 2001. [DOI: 10.1016/s1130-1473(01)70760-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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423
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Camacho J, Sánchez A, Stühmer W, Pardo LA. Cytoskeletal interactions determine the electrophysiological properties of human EAG potassium channels. Pflugers Arch 2000; 441:167-74. [PMID: 11211100 DOI: 10.1007/s004240000420] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The electrophysiological properties of ether a go-go (EAG) potassium channels are modified during the cell cycle when they are expressed in heterologous systems. In Chinese hamster ovary (CHO) mammalian somatic cells we found that the cell-cycle-dependent modulation of human EAG (hEAG) channels occurs during the M phase. This modulation has three components: reduction in current density, increased sensitivity to block by intracellular sodium, and increased selectivity for potassium ions. In this work, these three properties have been used to define the mitotic phenotype of EAG currents. The signaling pathway leading to such changes of channel properties is unknown. We tested the hypothesis that cytoskeletal interactions might affect the electrophysiological changes observed during the cell cycle. The disruption of actin filaments induces a significant increase in current density, without inducing the cell-cycle-related phenotype. In contrast, disturbance of the microtubules, achieved by pharmacological means or by mechanical excision of the membrane patch, does induce the cell-cycle-related phenotype. Our results demonstrate that hEAG channels establish complex interactions with cytoskeletal elements, and that these interactions strongly influence the properties of the channels. We also conclude that the electrophysiological changes observed during the cell cycle are most likely due to reorganization of the cytoskeleton during the G2/M transition.
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424
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Quiroga J, Insuasty B, Abonia R, Mejía D, Nogueras M, Sánchez A, Cobo J, Low JN. 2-Hydroxyphenyl 2-methylpyrazolo[1,5-a]pyrimidin-6-yl ketone. Acta Crystallogr C 2000; 56:1455-6. [PMID: 11118987 DOI: 10.1107/s0108270100012324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2000] [Accepted: 09/07/2000] [Indexed: 11/10/2022] Open
Abstract
The molecules of the title compound, C(14)H(11)N(3)O(2), form a three-dimensional soft hydrogen-bonded network involving C-H...N hydrogen bonds.
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425
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Sánchez A, Martínez I, Sanz F, López F, Aguado JM. [Aggressive acute endocarditis caused by Staphylococcus lugdunensis complicated with multiple cerebral septic emboli]. Enferm Infecc Microbiol Clin 2000; 18:526-7. [PMID: 11198008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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