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A Seoane

Publications and source records attributed to A Seoane.

At least 19 recordsLinked to original sources
PubMed2005

Applicability of the Rockall score in patients undergoing endoscopic therapy for upper gastrointestinal bleeding.

BACKGROUND: The Rockall score is used to assess the prognosis of patients with upper gastrointestinal bleeding. AIM: To assess the applicability of the Rockall score in patients undergoing endoscopic therapy for upper gastrointestinal bleeding. METHODS: Retrospective evaluation of the Rockall score in the period 1995-2001. To evaluate the applicability of the Rockall system, two groups were created: group I (Rockall or=6 points). RESULTS: Two hundred and twenty-two patients were included. The median age of patients was 65 +/ -17 years. Hypotension and associated diseases were present in 20 and 50% of patients, respectively. Re-bleeding occurred in 50 patients (23%) whose median score was 7, whereas the median score of patients without re-bleeding was 6 (p=0.14). There were 20 deaths (9%) with a median score of 8, whilst the median score of surviving patients was 6 (p<0.001). Sixteen patients in group I (18.4%) and 34 in group II (25.2%) re-bled (p=0.25). All the patients who died belong to group II with a Rockall score>or=6 (15% versus 0% in groups II and I, respectively, p<0.001). CONCLUSION: The Rockall score can be used in patients who undergo therapeutic endoscopy for upper gastrointestinal bleeding to identify those with high risk for mortality.

Aged↗
PubMed2005

Differential effects of trans-crotononitrile and 3-acetylpyridine on inferior olive integrity and behavioural performance in the rat.

The inferior olive climbing fibre projection is key to cerebellar contributions to motor control. Here we present evidence for a novel tool, trans-crotononitrile (TCN), to selectively inactivate the olive to study its functions. Anatomical, electrophysiological and behavioural techniques have been used in rats to assess the CNS effects of TCN, with a focus on the olivocerebellar projection. These findings were compared with those obtained with 3-acetylpyridine (plus nicotinamide administered 3.5 h later, 3AP + 3.5 h). Fluoro-Jade B cell labelling showed that TCN and 3AP + 3.5 h induce neurodegeneration primarily within the inferior olive, with no other targets in common. Recordings of evoked field potentials on the cerebellar cortical surface showed that both neurotoxins can reduce transmission in climbing fibre but not mossy fibre pathways. Both histological and electrophysiological differences suggest that TCN and 3AP have distinct mechanisms of action. Estimates of the numbers of surviving cells within individual subdivisions of the olive indicate that TCN and 3AP + 3.5 h cause different patterns of subtotal olivary lesion: most surviving neurons are present in the rostral (TCN) or caudal (3AP + 3.5 h) parts of the medial accessory olive, which are associated with two different cerebellar modules: the C2 and A modules, respectively. In behavioural studies, TCN and 3AP + 3.5 h produced differences in motor deficits consistent with the notion that these cerebellar modules have distinct functional responsibilities. Thus, studies using TCN as compared with 3AP + 3.5 h have the potential to shed light on the contributions of different cerebellar modules in motor control.

Animals↗
PubMed2005

[Helicobacter pylori and gastric cancer: relationship with histological subtype and tumor location].

INTRODUCTION: Helicobacter pylori (HP) has been implicated in the pathogenesis of gastric adenocarcinoma. Published data on HP infection and its association with both histological subtype and tumor localization are contradictory and few data are available on this topic in Spain. The aim of the present study was to evaluate the association of HP infection with histological subtype and tumor localization in a series of patients with gastric adenocarcinoma. MATERIAL AND METHOD: We retrospectively reviewed all the patients diagnosed with gastric neoplasms in Hospital del Mar in Barcelona between 1995 and 2001. The histological subtype was established using Lauren's classification. Tissue samples were obtained from the surgical specimen or from endoscopic biopsies. HP infection was histologically determined through hematoxylin-eosin, Masson's trichromic, and Giemsa staining. RESULTS: During the study period, 304 gastric neoplasms, 275 (90.4%) adenocarcinomas, 22 (7.2%) lymphomas, 3 (1.0%) leiomyosarcomas, 2 (0.7%) degenerated gastrointestinal stromal tumors (GIST) and 2 (0.7%) Kaposi's sarcomas were diagnosed. In patients with adenocarcinoma, the mean age at diagnosis was 69 years and most patients were male (62%). A total of 48.1% of the neoplasms were located in the gastric antrum, 23.7% in the body and 19.1% in the fundus (13.6% in the period 1994-1997 and 25.4% in the period 1998-2001, p = 0.018). Intestinal-type gastric carcinoma was observed in 56% of the patients, diffuse-type in 28% and indeterminate-type in 16%. HP infection was confirmed in 69% of the patients (68% in intestinal subtype, 69% in diffuse subtype, and 69% in indeterminate subtype, p = 0.84), and was significantly associated with distal adenocarcinomas vs. proximal adenocarcinomas (73.6% vs 48.6%, p < 0.05). CONCLUSIONS: No differences were observed between the histological type of adenocarcinoma and HP infection. In the last few years, the incidence of fundic adenocarcinomas has increased. These tumors show a lower association with HP infection.

Adenocarcinoma↗
PubMed2005

Role of Helicobacter pylori in stomach cancer after partial gastrectomy for benign ulcer disease.

OBJECTIVE: To determine the prevalence of Helicobacter pylori infection in patients having undergone gastrectomy for non-neoplastic disease who later developed gastric stump cancer. MATERIAL AND METHODS: Retrospective study of all patients with partial gastrectomy for non-malignant peptic disease who were submitted to an endoscopic exploration between 1995 and 2001. A comparison was made of major clinical and histological characteristics, and the presence of Helicobacter pylori among patients with and without gastric cancer in the stomach remnant. RESULTS: A total of 73 patients were studied in this period. Fifteen patients (20.5%) had remnant-stump gastric cancer. All but one were adenocarcinomas (71% intestinal and 29% diffuse, respectively). The average time between diagnosis of gastric cancer and previous gastrectomy was 32 (14-48) years. There was a higher detection rate of Helicobacter pylori in patients with cancer in the gastric remnant (100 vs. 81.5%, respectively, p < 0.07). No relationship was seen between type of gastric reconstruction (Billroth I or II) and rate of Helicobacter pylori detection. CONCLUSIONS: Helicobacter pylori infection is frequent in patients with previous gastrectomy for non-neoplastic disease. The results of the study suggest that Helicobacter pylori infection may play a role in gastric stump cancer.

Adenocarcinoma↗
PubMed2003

Cytogenetic analysis in Chinese hamster cells chronically exposed to low doses of X-rays.

PURPOSE: It is important to develop simple experimental models to assess the induction of DNA damage and study the different factors involved under controlled conditions. This paper describes the cytogenetic analysis carried out in Chinese hamster cells (CHO) sequentially exposed to very low doses of X-rays. MATERIALS AND METHODS: CHO cells were cultured for 14 passages. Irradiation treatment was performed once per passage, and three irradiation doses were employed: 2.5, 5.0 and 10.0 mSv. RESULTS: Sequential irradiation of CHO cells did not increase the yield of chomatid- or chromosome-type aberrations. However, a significant increase of achromatic lesions (gaps) was found after the first or second X-ray dose, with all three irradiation doses employed. CONCLUSIONS: The variation in the frequency of gaps as well as that in the mitotic index during the 14 cycles of radiation could be an indication of the induction of genomic instability. According to this, continuous rises and falls in the frequency of gaps as well as in the mitotic index reflects the simultaneous induction of endogenous DNA damage, cell death and cell survival.

Animals↗
PubMed2001

Relationship between insult intensity and mode of hair cell loss in the vestibular system of rats exposed to 3,3'-iminodipropionitrile.

A variety of stimuli cause sensory hair cell loss in the mammalian inner ear. This loss occurs by several differing processes, the significance of which remains undetermined. This study examines the relationship between the intensity of the damaging stimulus and the mode of hair cell loss found in the vestibular sensory epithelia of the rat. The ototoxin 3,3'-iminodipropionitrile (IDPN) was administered to rats at three different intoxication rates: acute exposure to high doses, repeated exposure to intermediate doses, and subchronic exposure to low doses. The morphology of the vestibular epithelia was examined by light microscopy and by scanning and transmission electron microscopy (SEM and TEM). In addition, DNA fragmentation in the epithelia was assessed by terminal deoxynucleotidyl transferase (tdt)-dUTP-nick-end-label (TUNEL). One day after acute IDPN, necrosis of hair cells was observed. However, at day 4 with this dose, and 1 and 4 days after repeated exposure, apoptotic figures and positive TUNEL labeling predominated. Subchronic IDPN resulted in a slowly evolving extrusion of basically intact hair cells in the crista and utricle. The data demonstrate that extrusion is a major mechanism of hair cell demise in mammals, that necrosis, apoptosis, and extrusion form a continuum of modes of hair cell loss, and that the intensity of the damaging stimulus determines the prevalence of each mode: Necrosis was most evident when the intensity was at its highest, whereas extrusion predominated when the intensity was at the lowest end of the scale.

Animals↗
PubMed2001

Pathology of the rat vestibular sensory epithelia during subchronic 3,3'-iminodipropionitrile exposure: hair cells may not be the primary target of toxicity.

3,3'-Iminodipropionitrile (IDPN) is a neurotoxic compound that causes proximal neurofilamentous axonopathy and loss of the vestibular sensory hair cells. During subchronic exposure, the hair cells are eliminated by extrusion of the virtually intact cell from the sensory epithelia towards the luminal cavity. We describe the alterations of the vestibular epithelia before and during hair cell extrusion. Adult male Long-Evans rats were exposed to 0.2% IDPN in the drinking water for 1, 3, 5, 8 or 14 weeks, or to 0.1% IDPN for 14 weeks. Protrusion and subsequent extrusion of hair cells were observed in the cristae and utricular maculae of rats exposed to 0.2% IDPN for at least 5 weeks. At earlier time points and at lower doses, we observed the following pathological signs: blebbing of hair cells, swelling, retraction and fragmentation of the afferent nerve terminals, detachment of hair cells from the surrounding structures and loss of the pre- and post-synaptic membrane thickenings between hair cells and their afferent terminals. Widespread enlargement of the intercellular spaces also preceded and accompanied the extrusion process. The present data challenge the hypothesis that IDPN specifically affects hair cells.

Animals↗
PubMed2000

Aneugenic effects of some metal compounds assessed by chromosome counting in MRC-5 human cells.

Development of a comprehensive test battery is necesary for the evaluation and detection of aneugenic chemicals. The chromosome couting method was used in the present study. The aneugenic ability of cadmium choride (1.0, 2.0 and 4.0x10(-3) mM), cadmium sulfate (3. 3, 6.7x10(-5) and 1.3x10(-4) mM), potassium dichromate (2.5, 5. 0x10(-4) and 1.0x10(-3) mM) and cacodilic acid (1.25, 2.5 and 5. 0x10(-2) mM) were analysed using MRC-5 cells which have a modal diploid number of 2 n=46 with a spontaneous aneuploid or polyploid cells not higher than 13% and 8%, respectively.All compounds induced significant increments of aneuploid cells in relation to negative controls. The frequency of aneuploid cells increased in all treatments with cadmium chloride. Cadmium sulfate induced significant increments of aneuploid cells with the two higher doses. All the doses of potassium dichromate increased the frequency of aneuploid cells although to a lesser degree than the other compounds. In these cases, differences were in the borderline of statistical significance (p<0.05). Moreover, a low number of cells could be analysed in treatments with the highest dose due to the decrease in the mitotic index. Results obtained are coincident with previous reports using the same methodology in the sense that induced aneuploidy was mainly evidenced by the increase of hypodiploid but not hyperdiploid cells. In addition, anaphase-telophase analysis of the effects of the same doses of these metal compounds in CHO cells showed significant increments of lagging chromosomes and increased frequencies of kinetochore positive micronuclei in MRC-5 cells. These findings could be considered as an indication that the main cause of unequal chromosome separation is the failure of kinetochores to attach the spindle apparatus either by alteration of its protein components or by the altered chromatid separation in anaphase.

Aneuploidy↗
PubMed2000

Efferent function of vestibular afferent endings? Similar localization of N-type calcium channels, synaptic vesicle and synaptic membrane-associated proteins.

We investigated the distribution of N-type voltage-dependent calcium channels that mediate Ca(2+) entry initiating transmitter release in the rat vestibular sensory epithelium. We used confocal microscopy to assess the in vitro labeling by fluorescent specific ligand binding, omega-conotoxin-GVIA and also the immunolabeling of presynaptic soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptor (SNARE) proteins, syntaxin, 25,000 mol. wt synaptosome-associated protein and synaptotagmin: components of the neurotransmitter exocytosis machinery. We found that there was a close anatomical association between the voltage-gated calcium channels, the synaptic vesicle and synaptic membrane-associated proteins on the afferent nerve calyces and probably afferent boutons, which are postsynaptic compartments. Our data suggest that these peripheral afferent endings possess the presynaptic Ca(2+) channels and the components of the presynaptic SNARE proteins involved in synaptic vesicle docking and calcium-dependent exocytosis. They provide additional evidence for a secretory function and efferent role of these endings in hair cell neurotransmission.

Afferent Pathways↗
PubMed2000

Identification of a streptogramin A acetyltransferase gene in the chromosome of Yersinia enterocolitica.

Streptogramins are polypeptide antibiotics inhibiting protein synthesis by the prokaryotic ribosome. Gram-positive organisms are susceptible to streptogramins, while most gram-negative bacteria are intrinsically resistant. We have found a genomic fragment from a Yersinia enterocolitica isolate with an open reading frame coding for a polypeptide similar to the virginiamycin acetyltransferases found in various plasmids from gram-positive bacteria. The susceptible Escherichia coli strain DB10 was transformed to resistance to the type A streptogramins and to mixed (A + B) streptogramins upon introduction of a plasmid containing that gene. In addition, we showed streptogramin acetylating activity in vitro dependent on the presence of the Y. enterocolitica sat gene. Southern blot hybridization experiments showed that the sat gene was present in all the Y. enterocolitica isolates examined. These data together show that the gene in the Y. enterocolitica chromosome encoded an active streptogramin acetyltransferase. The deduced sequence of the Y. enterocolitica Sat protein was close to those of sat gene products found in gram-positive bacteria and cyanobacteria, suggesting a common evolutionary origin.

Acetyltransferases↗
PubMed1999

Degeneration and gliosis in rat retina and central nervous system following 3,3'-iminodipropionitrile exposure.

3,3'-Iminodipropionitrile (IDPN) exposure causes a neurofilamentous axonopathy and olfactory, audiovestibular and visual toxicity. Many events relevant to these effects and the neurotoxic properties of nitriles as a class remain to be elucidated. We characterized the gliosis associated with the IDPN-induced retinal degeneration in comparison to other effects on the visual and central nervous systems. Gliosis was quantified using an ELISA for the intermediate filament protein, glial fibrillary acidic protein (GFAP). IDPN (0-400 mg kg-1 day-1x3 days, i.p.) caused corneal opacity and dose- and time-dependent increases in retinal GFAP, up to 26-28 fold of control values at 4 weeks post-exposure; a second peak occurred at 16 weeks. In contrast, GFAP peaked at 1 week in olfactory bulbs (OB), cingulate cortex and hippocampus. Cerebellum and striatum showed no gliosis. Retinal dopamine decreased within 2 weeks. Delayed GFAP increases occurred in superior and inferior colliculi. Retina and superior colliculi also showed increased [3H]PK-11195 binding. Histological analysis demonstrated progressive degeneration and gliosis in retina and colliculi. Taken together, the data indicate that primary and secondary degenerative events occur in the retina, and that this retinal degeneration induces GFAP increases in retina and superior colliculus. In addition, GFAP assays demonstrated that the retinal toxicity of IDPN is enhanced by CCl4 hepatotoxicity and blocked by methimazole inhibition of flavin-mono-oxygenases, similarly to its ototoxicity. GFAP assays also indicated that neither vestibulotoxic doses of crotononitrile nor olfatotoxic doses of dichlobenil damage the retina. The data support the use of GFAP assays for assessing the retinal toxicity of IDPN and other nitriles.

Animals↗
PubMed1999

[UTIscreen versus UROQUICK: two semiautomatic systems for bacteriuria detection].

BACKGROUND: The aim of the study is to find a rapid and reliable method for urine screen. With this purpose two semiautomatic systems have been evaluated: UTIscreen and UROQUICK. MATERIAL AND METHODS: We have carried out a prospective study of a total 1,070 urine specimens from patients with suspected urinary infection. Each sample has been inoculated in the two semiautomatic systems and compared with the semiquantitative plate culture as the reference method. RESULTS: Both semiautomatic systems showed similar specificity and sensitivity at an interpretative breakpoint of 30,000 CFU/ml, with a low number of false positives. Uninfected specimens can be reported the same day of reception. CONCLUSIONS: Both UTIscreen and UROQUICK systems seem to be adequate for urinary tract infection screening. They are reliable and easy to perform, but in our particular case we find advantage in using UTIscreen because the faster reading of this system makes posible to report the negative results in the same morning of reception of the specimen and do the culture of all the positive samples during our usual working schedule.

Bacteriuria↗
PubMed1999

[Anti-A antibodies and bacterial contamination of platelet concentrates].

OBJECTIVES: The possible ABO group antibodies protective function against several infections has been classically described. We analyze the platelet concentrates (PC) bacterial control results and their ABO antibodies. MATERIAL AND METHODS: We studied 245 outdated PCs (> 5 days). The samples were sterilely collected for adequate microbiological investigation studies on sheep-blood agar plates. If bacterial growth is found, the microbiological identification is performed on the basis of standard tests, the specific anti-biotype being achieved by disk-diffusion method on Müeller-Hinton agar plates, and the red cell concentrate was analyzed. RESULTS: Bacterial growth by negative coagulase Staphylococcus was found in 10 PCs (4.1%; CI95%; 1.97-7.37). The contaminated PCs lacked natural anti-A antibodies. There were no statistical differences when we analyzed the PC's age, colour or blood group. COMMENTS: The anti-A antibodies may be a protective factor versus PCs contamination caused by resident bacteria.

ABO Blood-Group System↗
PubMed1998

[Incidence of Cryptosporidium in Zaragoza: an 8-year study (1989-1996)].

BACKGROUND: To study the incidence of Cryptosporidium infections over an eight year period in an urban area, together with the patients background and the season of the year. MATERIALS AND METHODS: From January 1989 to December 1996, all 32,733 stool samples from 13,639 patients: children and immunocompromised adults, with presumed infective diarrhoea, were investigated for Cryptosporidium oocysts by the Department of Microbiology, Miguel Servet Hospital, Zaragoza (Spain). RESULTS: Cryptosporidial infection was identified in a 3% of the total children, been the positivity rate highest in the 2-year old group. We visualized oocysts in the 8% of the immunocompromised patients, all of them HIV-positive. The prevalence was higher in winter (February-March). CONCLUSIONS: According to these findings we conclude that Cryptosporidium should be systematically searched by clinical laboratories, specially in children and in immunocompromised patients suffering from infectious diarrhoea.

Adolescent↗
PubMed1997

Efficacy and safety of two new methods of rapid intravenous detoxification in heroin addicts previously treated without success.

BACKGROUND: New methods of rapid opiate detoxification, under intravenous sedation, can detoxify heroin-addicted patients in 24 hours. Their clinical application has been limited by the lack of studies establishing both efficacy and safety. METHOD: In a randomised, controlled study, 300 treatment-refractory, heroin-addicted patients received rapid intravenous detoxification treatment (naloxone infusion, 0.06-0.08 mg/kg, then oral naltrexone 50 mg/day) under either monitored light intravenous sedation or unmonitored deep intravenous sedation. RESULTS: All patients were successfully detoxified and 93% remained abstinent one month later. Severity of withdrawal, according to the Wang Scale modified by Loimer, was 4.9 (s.d. 3.0) points in the light sedation group and 4.8 (s.d. 2.9) in the deep sedation group (P = 0.26). Two patients (1.3%) in the light sedation group and four (2.6%) in the deep sedation group required tracheal intubation (P = 0.31). There was only one severe complication, a case of nosocomial aspirative pneumonia which improved with antibiotic treatment. CONCLUSIONS: Successful rapid intravenous detoxification can be achieved using relatively light levels of sedation.

Adult↗