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J Lopez

Publications and source records attributed to J Lopez.

At least 19 recordsLinked to original sources
PubMed2001

Increasing volume and changing characteristics of invasive pulmonary aspergillosis on sequential thoracic computed tomography scans in patients with neutropenia.

PURPOSE: In patients with neutropenia, thoracic computed tomography (CT) halo and air-crescent signs are recognized as major indicators of invasive pulmonary aspergillosis (IPA). Nevertheless, the exact timing of CT images is not well known. PATIENTS AND METHODS: Seventy-one thoracic CT scans were analyzed in 25 patients with neutropenia with surgically proven IPA. RESULTS: On the first day of IPA diagnosis with early CT scan (d0), a typical CT halo sign was observed in 24 of 25 patients. At that time, the median number of thoracic lesions was two (range, one to six), and pulmonary involvement was bilateral in 12 cases. The halo sign was present in 68%, 22%, and 19% of cases on d3, d7, and d14, respectively. Similarly, the air-crescent sign was seen in 8%, 28%, and 63% of cases on the same days. Otherwise, a nonspecific air-space consolidation aspect was seen in 31%, 50%, and 18% of cases on the same days. The analysis of calculated aspergillary volumes on CT showed that, despite antifungal treatment, the median volume of lesions increased four-fold from d0 to d7, whereas it remained stable from d7 to d14. Overall, 21 patients (84%) were cured by the medical-surgical approach. CONCLUSION: In patients with neutropenia, CT halo sign is a highly effective modality for IPA diagnosis. The duration of the halo sign is short, and it demonstrates the value of early CT. The increase of the aspergillosis size on CT in the first days after IPA diagnosis is not correlated with a pejorative immediate outcome when using a combined medical-surgical approach.

Adolescent↗
PubMed2001

The diagnostic accuracy of mammography in the evaluation of male breast disease.

BACKGROUND: The role of mammography in the evaluation of male patients presenting with breast disease is controversial. This controversy is a function of the lack of specific data concerning the diagnostic accuracy of mammography when used in this clinical setting. The purpose of this study was to define the diagnostic accuracy of mammography in the evaluation of male breast disease. METHODS: One hundred and four prebiopsy mammograms from 100 patients with tissue diagnoses were read blindly by two independent radiologists, and placed into one of five predetermined categories: definitely malignant, possibly malignant, gynecomastia, benign mass, and normal. Radiologic/pathologic correlation was performed and the sensitivity (Sn), specificity (Sp), positive (Ppv) and negative predictive value (Npv), and accuracy (Ac) for each of the mammographic diagnostic category determined. RESULTS: The pathologic diagnoses were 12 cancers, including 1 patient with bilateral breast cancer, 70 cases of gynecomastia, 16 benign masses, and 6 normals. The accuracy data for the mammographic diagnostic categories are as follows: malignant (combined definitely and possibly malignant), Sn 92%, Sp 90%, Ppv 55%, Npv 99%, Ac 90%; and overall benignity (combined gynecomastia, benign mass, and normal), Sn 90%, Sp 92%, Ppv 99%, Npv 55%, Ac 90%. Six cancers (50%) coexisted with gynecomastia. CONCLUSIONS: Mammography can accurately distinguish between malignant and benign male breast disease. Although not a replacement for clinical examination, its routine use could substantially reduce the need for biopsy in patients whose mammograms and clinical examination suggest benign disease.

Breast Neoplasms, Male↗
PubMed2001

Decrease in Candida albicans strains with reduced susceptibility to fluconazole following changes in prescribing policies.

This study was undertaken to identify prescribing policies likely to favour or limit fluconazole resistance within a clinical department. Fluconazole exposure within the infectious diseases and clinical haematology units was investigated, and data were compared with in vitro susceptibility of Candida albicans isolates obtained in these units. Fluconazole utilization was determined by the number of fluconazole treatment-days per 100 hospitalization days (penetration index). In the infectious diseases unit, separate evaluations for low-dose fluconazole (50 mg) prescribed as intermittent or prolonged treatment, and for higher-dosing schedules (fluconazole 200 mg) were made. Susceptibility of C. albicans isolates was surveyed in a broth microdilution assay by measuring the inhibitory concentration 50% (IC50). The penetration index (PI) for fluconazole 50mg declined from 1992 to 1977 in infectious diseases (P= 0.0048). In the meantime, total usage of fluconazole increased, due to increased prescribing of fluconazole 200 mg (P = 0.0724). The IC50 of C. albicans isolates tested in infectious diseases decreased between 1994 and 1996 from 7.33 mg/ml to 1.64 mg/ml (P = 0.0075). In clinical haematology, declines in C. albicans IC50 and fluconazole PI were not significant (P = 0.35 and P = 0.07, respectively). These data suggest that prolonged or repeated exposure to low-dose fluconazole, rather than total cumulative use, was associated with fluconazole resistance in the infectious diseases unit. Moreover, restoration of a normal ecology was observed when low-dose prolonged or intermittent prescriptions were reduced.

Analysis of Variance↗
PubMed2000

Correlation of CD34+ cell counts with volume of bone marrow collected for allogeneic bone marrow harvests.

The quantity of bone marrow collected for allogeneic bone marrow transplantation is based on collecting 10 to 15 cc of bone marrow/kg of recipient weight. We hypothesized that the percentage of CD34+ cells collected during a bone marrow harvest decreased at the end of the harvest because of increasing amounts of peripheral blood contamination. We performed a prospective, blinded study in which we measured CD34+ percentages and cell counts at 200-cc intervals during bone marrow harvests from 11 consecutive human leukocyte antigen (HLA)-matched sibling bone marrow donors. We observed that the percentage of CD34+ cells in aspirated bone marrow did not vary significantly from the start to the end of the bone marrow harvest, and the total number of CD34+ cells/kg increased in a linear fashion, thus disproving our original hypothesis. In conclusion, the percentage of CD34+ cells in aspirated bone marrow will remain constant throughout a bone marrow harvest.

Adolescent↗
PubMed2000

[(99m)Tc]-sestamibi parathyroid scintigraphy in chronic haemodialysis patients: static and dynamic explorations.

BACKGROUND: The place of parathyroid gland imaging by [(99m)Tc](technetium)-sestamibi scintigraphy in uraemic patients with secondary hyperparathyroidism remains a matter of debate. The purpose of the present study was (i) to assess its value with respect to plasma intact parathyroid hormone (iPTH) levels and to surgical parathyroidectomy (PTx), and (ii) to explore the possibility of suppressing parathyroid [(99m)Tc]-sestamibi uptake by calcitriol. METHODS: In a first cross-sectional, static study 52 chronic haemodialysis (HD) patients with plasma iPTH levels between 14 and 2791 pg/ml (normal, 10-65 pg/ml) had a [(99m)Tc]-sestamibi scan, and 21 of them underwent surgical PTx. In a second longitudinal, dynamic study 14 chronic HD patients with advanced secondary hyperparathyroidism received short-term calcitriol treatment in an attempt to suppress [(99m)Tc]-sestamibi imaging of parathyroid glands. Calcitriol was given intravenously for 2 weeks, 2 microg after each haemodialysis session. Scintigraphy was carried out before and at the end of this inhibition test. RESULTS: [(99m)Tc]-Sestamibi scan led to imaging of one or more (maximum three) parathyroid glands in most, but not all, HD patients with plasma iPTH values >600 pg/ml. Based on surgical findings, overall sensitivity of [(99m)Tc]-sestamibi scan in correctly locating parathyroid glands was only 50%, whereas specificity was 100%. In contrast, its sensitivity was 100% in locating single glands in the subgroup of five patients with recurrent hyperparathyroidism. The calcitriol inhibition test showed suppression of [(99m)Tc]-sestamibi uptake by at least one parathyroid gland in eight patients (57%), with complete suppression in five of them (36%). Basal plasma iPTH or decrease of plasma iPTH in response to calcitriol was not predictive of suppressible [(99m)Tc]-sestamibi uptake in the individual case, although mean iPTH was markedly higher in patients with non-suppressible parathyroid glands. CONCLUSION: Because of its relatively low sensitivity the [(99m)Tc]-sestamibi scan is of limited help in the exploration of uraemic patients with severe secondary hyperparathyroidism before a first surgical PTx. However, it is very useful in locating the remaining parathyroid gland(s) in case of reoperation. The novel calcitriol inhibition test of [(99m)Tc]-sestamibi uptake could help to better distinguish parathyroid glands with non-suppressible, autonomous activity from glands whose activity might be amenable to long-term suppression.

Calcitriol↗
PubMed2000

Helicobacter pylori eradication prevents recurrence from peptic ulcer haemorrhage.

BACKGROUND: Successful eradication of Helicobacter pylori infection clearly modifies the natural history of peptic ulcer disease and prevents further recurrences of duodenal and gastric ulcers. However, there are few prospective studies about actual rates of rebleeding after H. pylori eradication, a highly relevant aspect of management as re-infection, relapse of ulcer disease for other reasons (i.e. anti-inflammatory agents) or idiopathic ulcers unrelated to H. pylori may develop and cause further bleeding episodes. OBJECTIVE: To determine the incidence of bleeding episodes after eradication of H. pylori infection in patients who had bled from an H. pylori-positive peptic ulcer. PARTICIPANTS AND INTERVENTIONS: H. pylori-positive patients who bled from a gastric or duodenal ulcer were treated with appropriate triple and/or quadruple therapy. H. pylori eradication was confirmed by urea breath test 4 weeks after treatment. Patients received no further treatment but were followed clinically and additional urea breath tests were performed every 6 months. Endoscopy with antral and corpus biopsies and urea breath test were repeated as soon as patients manifested any dyspeptic symptoms that might signal recurrence. RESULTS: A total of 103 patients with bleeding duodenal ulcer were included in the study; H. pylori was successfully eradicated in 93 of these patients, who were followed for a median interval of 27 months. The yearly re-infection rate was calculated to be 0.6%. There were no instances of rebleeding in any patients during the follow-up period. CONCLUSIONS: Even after prolonged follow-up, successful H. pylori eradication prevents rebleeding.

Adult↗
PubMed2000

Comparative genotyping of Candida albicans bloodstream and nonbloodstream isolates at a polymorphic microsatellite locus.

Molecular typing studies have shown that the predominant form of reproduction of Candida albicans is clonal and that, in a majority of situations, persistent or recurrent infections are due to a unique strain. Characterization of distinct subpopulations and correlation with clinical features may thus be important to understanding the pathogenesis of candidiasis. In a clonal model, a unique polymorphic marker may identify populations with different biological properties. We therefore compared 48 bloodstream isolates and 48 nonbloodstream matched strains of C. albicans at the elongation factor 3-encoding gene (CEF3) polymorphic microsatellite locus of C. albicans. Sizing of the alleles was performed by automated capillary electrophoresis. A new, 137-bp allele was characterized, and seven nondescribed combinations were observed, resulting in 15 and 11 distinct CEF3 profiles in bloodstream and control strains, respectively. Genotypes 126-135, 130-136, and 131-131 accounted for 60.4% of both bloodstream and control strains. Four bloodstream isolates but no control strains displayed the 135-135 combination. None of the other genotypes was present at an increased frequency in bloodstream isolates. Bloodstream and nonbloodstream strains of C. albicans thus have a heterogeneous structure at the CEF3 locus, with three major and multiple minor allelic combinations.

Alleles↗
PubMed1999

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Journal Article↗
PubMed1999

Immunodetection of the microvillous cytoskeleton molecules villin and ezrin in the parasitophorous vacuole wall of Cryptosporidium parvum (Protozoa: Apicomplexa).

Microvilli - actin - villin - ezrin - Cryptosporidium parvum The sporozoites and merozoites of the Apicomplexan protozoan Cryptosporidium parvum (C. parvum) invade the apical side of enterocytes and induce the formation of a parasitophorous vacuole which stays in the brush border area and disturbs the distribution of microvilli. The vacuole is separated from the apical cytoplasm of the cell by an electron-dense layer of undetermined composition. In order to characterize the enterocyte cytoskeleton changes that occur during C. parvum invasion and development, we used both confocal immunofluorescence and immunoelectron microscopy to examine at the C.parvum-enterocyte interface the distribution of three components of the microvillous skeleton, actin, villin and ezrin. In infected cells, rhodamine-phalloidin and anti-villin and anti-ezrin antibodies recognized ring-like structures surrounding the developing parasites. By immunoelectron microscopy, both villin and ezrin were detected in the parasitophorous vacuole wall surrounding the luminal and lateral sides of the intracellular parasite. In contrast, anti-beta and anti-gamma actin antibodies showed no significant labelling of the vacuolar wall. These observations indicate that the parasitophorous vacuole wall contains at least two microvillus-derived components, villin and ezrin, as well as a low amount of F-actin. These data suggest that C.parvum infection induces a rearrangement of cytoskeleton molecules at the apical pole of the host cell that are used to build the parasitophorous vacuole.

Actins↗
PubMed1999

Prospective analysis of complications 30 days after outpatient colonoscopy.

BACKGROUND: Our objective was to (1) determine whether more complications are reported by patients 30 days after outpatient colonoscopy than are discussed at our monthly morbidity and mortality conferences, (2) identify complications resulting in visits to the emergency department or physician's office or leading to hospitalization, and (3) assess which factors put patients at highest risk. A secondary goal was to determine the rate of work lost after outpatient colonoscopy. METHODS: Trained interviewers performed standardized telephone interviews of consecutive outpatients undergoing colonoscopy at Georgetown University Hospital over a 1-year period. RESULTS: One thousand one hundred ninety-six patients were contacted 30 days after outpatient colonoscopy and participated in our study. Twenty patients had complications that required a visit to an emergency department or physician. Ninety percent of these cases (18) were detected at 30 days, but 15% (3) were discussed at morbidity and mortality conferences. All seven complications that necessitated hospitalization were identified at 30 days, but only two were discussed at our morbidity and mortality conference. The most common complications reported by patients were abdominal discomfort (5.4%) and rectal bleeding (2.1%). CONCLUSION: More complications are detected by means of contacting patients 30 days after outpatient colonoscopy than are discussed at our morbidity and mortality conferences.

Abdominal Pain↗
PubMed1999

Synchronous laparoscopic vasectomy and hernia repair.

Over the last few years, general surgery has seen the use of more and more laparoscopic techniques in the management of common surgical problems. This expanded use is attributable not only to the excellent results seen with laparoscopic procedures but also to patient demand. A 48-year-old man requested a laparoscopic hernia repair with synchronous vasectomy. The technique of synchronous laparoscopic hernia repair and vasectomy is discussed, and a literature review is provided. Certain disadvantages along with the difficulty in reanastomosis after a laparoscopic vasectomy will prevent the replacement of traditional vasectomy with the laparoscopic technique.

Hernia, Inguinal↗
PubMed1999

Prospective analysis of complications 30 days after outpatient upper endoscopy.

OBJECTIVE: The aim of this study was to compare complication rates reported by patients 30 days after outpatient upper endoscopy with those discussed at our monthly morbidity and mortality conference. We also intended to establish which complications were reported most frequently 30 days after upper endoscopy, and which patients or procedures involved the highest risk. METHODS: Trained interviewers performed standardized telephone interviews on consecutive outpatients undergoing upper endoscopy over a 1-yr period. Patients were queried regarding potential events related to their upper endoscopy in the 30 days subsequent, including symptoms, emergency room (ER) and/or physician visits, and hospitalizations. The indications, findings, and therapies were reviewed from endoscopic reports. RESULTS: A total of 473 patients were contacted 30 days after outpatient upper endoscopy and agreed to participate in our study. The most common complications reported by patients at 30 days were sore throat (9.5%) and abdominal discomfort (5.3%). Twelve patients (2.5%) required an ER/physician visit and five patients (1.1%) required hospitalization. The minority of both ER/physician visits (16.7%) and hospitalizations (40%) were discussed at our monthly morbidity and mortality conferences. CONCLUSIONS: More complications were reported by patients 30 days after outpatient upper endoscopy than were discussed at our monthly morbidity and mortality conferences. The most frequent complications reported by patients were sore throat and abdominal pain. The minority of ER/physician visits and hospitalizations were discussed at our morbidity and mortality conferences.

Abdominal Pain↗