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R Abad

Publications and source records attributed to R Abad.

At least 19 recordsLinked to original sources
PubMed2006

Sequencing of the porB gene: a step toward a true characterization of Neisseria meningitidis.

Variations in class 2/3 (PorB) proteins form the basis for meningococcal serotyping. Antibodies against these proteins are bactericidal, making serotyping results useful not only for epidemiological surveillance of meningococcal disease but also for identifying potential vaccine components. A total of 20 to 60% of meningococcal B and C isolates from any given population are nontypeable (NT) using a panel of monoclonal antibodies. To analyze the mechanisms responsible for the nonserotypeability characteristic in Neisseria meningitidis, we (i) established the nucleotide sequences of porB gene in 146 meningococcal strains (95 not recognized by the serotyping panel), (ii) identified 18 new allelic variants of the porB gene, (iii) correlated allelic variants with serotypes, (iv) suggest the nontypeability characteristic in those 95 NT strains, and (v) reject the possibility of variation in the levels of PorB expression.

Molecular Sequence Data↗
PubMed2006

Endoscopic staging of low-grade gastric MALT lymphoma.

INTRODUCTION: Endoscopic ultrasonography (EUS) has already proven useful in the assessment of submucosal lesions, and the staging of gastrointestinal cancer, particularly gastric MALT-type lymphoma. The goal of this paper was EUS staging. PATIENTS AND METHOD: 24 patients (10 females, 14 males) with a median age of 56 years and possibly gastric MALT lymphoma (25 cases) were studied using videoendoscopy, biopsies, and echoendoscopy with 7.5- and 20-MHz radial EUS, and also with 12- and 20-MHz miniprobes (MPs). Nineteen patients were definitely evaluated (7 females, 12 males) as having 20 MALT-type lymphomas, as five patients were post-hoc disregarded when an invasive, high-grade gastric lymphoma (3c) or plasmocytoma (2c) was subsequently demonstrated. Of these 19 patients, all had T1 lesions except for two with T2 lesions; one patient had a gastroduodenal T1 lymphoma. Echographic findings with MPs were compared to EUS (gold standard) and histology both before and after eradication. Then, patients were followed up every 1-3-6 months using videoendoscopy and MPs. RESULTS: Echoendoscopy correctly identified T stages in 90% of cases. MPs identified T stages in 88% of cases, and N stages in 33% of cases, with results being slightly inferior to those obtained with conventional EUS (91 vs. 45%); they were consequently used for follow-up. After eradication, all but two patients are in complete remission and have been followed every 1-3-6 months using MPs without echographic abnormalities, except for a patient who relapsed.

Adolescent↗
PubMed2006

EUS-guided mucosectomy for gastrointestinal cancer.

INTRODUCTION: the only way of improving prognosis and survival in gastrointestinal cancer is early diagnosis, with intramucosal localization as confirmed by endoscopic ultrasonography (EUS) or 20-MHz miniprobes (MPs) (T1) being most appropriate. Endoscopic mucosal resection (EMR) has proven effective in the treatment of this sort of lesions. PATIENTS AND METHOD: in a group (18 cases) with 15 cases of superficial gastrointestinal cancer and 3 cases of severe gastric dysplasia, 9 cases (3 esophageal, 4 gastric, 2 rectal) underwent a classic EMR following EUS or a 7.5- and 20-MHz miniprobe exploration. RESULTS: ultrasonographic studies showed a T1 in all but one esophageal case (Tis), and in both gastric dysplasias, with no changed layer structure being demonstrated in the latter (T0). No complications arose with classic EMR, and all 9 patients are alive and free from local or metastatic recurrence, except for one esophageal case, which recurred distally to the esophageal lesion (metachronous). CONCLUSIONS: echoendoscopically-assisted EMR is a safe, effective technique in the endoscopic management of superficial gastrointestinal (esophageal, gastric, colorectal) cancer. Recurrence most likely depends upon cancer multiplicity.

Aged↗
PubMed2005

Our cumulative experience with transendoscopic miniprobes.

INTRODUCTION: Transendoscopic miniprobes (TEMPs) have nowadays precise indications, but may become a diagnostic alternative to both radial and sectorial endoscopic ultrasonography (EUS) in the near future. PATIENTS AND METHODS: From November 1996 to July 2004 we carried out 620 examinations using TEMPs (124 during the last 12 months in 2003, with currently a mean of 11 examinations/month). Twenty explorations were performed with radial, 12.5 MHz (20 mm penetration), 6.2 F (2 mm diameter), 950 mm or 2000 mm Microvasive Endosound probes. Twenty explorations were performed using a 12 MHz (29 mm mean penetration) or 20 MHz (18 mm penetration) Olympus UM-2R/3R, or with a 12 MHz UM-DP12-25R or 20 MHz UM-DP20-25 R DPR-fitted Olympus probe, 2.5 mm in diameter and 2050 mm in length. A 20 MHz, 2.2 mm, wire-guided G20-29R was used for intraductal studies. In all, 580 examinations were carried out with both radial and linear, 12 MHz (240 E) or 20 MHz (60 E) Fuji probes, 2.6 mm in diameter and 1900 mm in length; and with a 7.5 MHz, 2.6 mm radial balloon microprobe with the well-known "preload" system that we have been using during the 1999-2004 period (280 E). Here we used a 3.2 mm working channel, whereas a 2.8 mm working channel was used with the remaining TEMPs. RESULTS: Twenty GI-tract examinations were performed with one Microvasive probe, which broke down when attempting its passage through the papilla. Currently we use a 20 MHz, 2.2 mm Olympus G20-29R guided microprobe for intraductal studies. We performed 100 gut examinations using one single Fuji TEMP (12 or 7.5 MHz). Organs explored included: esophagus and stomach, 60%; rectum and colon, 30%; other (duodenum, papilla, bile ducts), 10%. INDICATIONS: cancer staging, 35%; submucosal lesions, 30%; other, 35% (including 20% of esophageal non-tumoral conditions). COMPLICATIONS: aspiration, perforation, and mortality, 0%. Morbidity, 10%, at the expense of abdominal pain as induced by endoscopy itself. All strictures were successfully passed, except for one malignant stenosis in the rectum. CONCLUSIONS: During a 93-month period (1996-2004) we performed 620 explorations with TEMPs, with a current average of 11 examinations/month. TEMP durability is around 100 gut explorations. The esophagus and stomach were examined in 60% of cases. Primary indications included gut cancer staging and submucosal lesions (65%). Perforation and mortality rates amounted to 0%.

Endosonography↗
PubMed2000

Evaluation of an immunocapture-agglutination test (Brucellacapt) for serodiagnosis of human brucellosis.

We evaluated the validity and the usefulness of a new test for the diagnosis of human brucellosis based on an immunocapture-agglutination technique. A total of 315 sera from 82 patients with a diagnosis of brucellosis, 157 sera from patients in whom brucellosis was suspected but not confirmed, and 412 sera from people living in rural areas with endemic brucellosis were studied. The seroagglutination test (SAT), Coombs anti-Brucella test, and Brucellacapt test were evaluated. All the initial sera from the 82 patients proved to be positive in Brucellacapt and Coombs tests, while only 75 (91.4%) were positive in the SAT. If a >/=1/160 diagnostic threshold titer was defined for the Brucellacapt test, Coombs test, and SAT, the sensitivities were 95.1, 91.5, and 65.8%, respectively. Taking the same diagnostic threshold titer for the 157 sera from the unconfirmed but suspected patients, the specificities of the Brucellacapt, Coombs, and SAT were 81.5, 96.2, and 100%, respectively; for the 412 control sera, the specificities were 99.0, 99.8, and 100%. The diagnostic efficiency (area below the receiver operating characteristic curve) of Brucellacapt was 0.987852 (95% confidence interval [CI], 0.95109 to 0.99286), very similar to the diagnostic efficiency of the Coombs test (0.97611; 95% CI, 0.94781 to 0.99146) and higher than that of SAT (0.91013; 95% CI, 0.86649 to 0.94317). The results of the Brucellacapt test were compared with those of the Coombs test (correlation coefficient, 0.956; P = 0.000) and SAT (correlation coefficient, 0.866; P = 0.000). The study shows very good correlation between the Brucellacapt and Coombs tests, with a high concordance between titers obtained in the two tests. Nevertheless, lower correlation and concordance were found between the Brucellacapt and Coombs tests when the results for titers of >/=1/160 were compared (0.692; P = 0.000). In acute brucellosis, the Brucellacapt and Coombs tests render positive titers of >/=1/160. When the titers are lower, they increase significantly in the following 30 days, despite the evolution of SAT titers. In contrast, Brucellacapt and Coombs titers are always high (>/=1/640) in brucellosis with long evolution, whether SAT titers are higher or lower than 1/160.

Adolescent↗
PubMed1999

[Echo-endoscopy: the clinical implications after a period of more than 16 years of its existence].

Endosonography is an imaging diagnostic technique recently introduced in our country. It allows us to perform an ultrasound from within the digestive tube. Because of the transducer proximity to the gut wall and the high frequency of emission we are able to visualize with great resolution small lesions as well as differentiate the five layers of the gastric wall and examine structures close to the digestive lumen with a 7 to 8 cm penetration. This is a brief introduction to the basic pillars of endosonography and its main indications, well defined after sixteen years of clinical practice.

Digestive System Diseases↗
PubMed1998

[The value of endoscopic ultrasonography in the study of submucosal tumors of the digestive tract].

Twenty-one consecutive patients with 24 possible submucosal lesions of the digestive tract were studied. Endoscopic ultrasonography (EUS) differentiated between 17 true positive submucosal tumors and 3 true negative extrinsic compressions. False positives were interpreted in 3 cases and in one patient no lesion was echoendoscopically observed (false negative). The sensitivity was 94%, the specificity 50% and the positive and negative predictive values were 82% and 75%, respectively. In conclusion, EUS may be the method of choice for the study of submucosal tumors since it allows visualization of the five layers of the wall of the digestive tract in which a tumor may originate, determination of its sonographic features, depth and exact size, in addition to the invasion of neighboring organs. Moreover, EUS may aid in collecting material for cytology and microscopy by fine needle aspiration puncture (FNAP) by EUS.

Adult↗