Search PubMed⌕ Search

Biomedical subjects

A Restrepo

Publications and source records attributed to A Restrepo.

At least 19 recordsLinked to original sources
PubMed2006

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: flow cytometry and GP43 sequence analysis.

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus.

Antigens, Fungal↗
PubMed2006

New insights into the cell cycle profile of Paracoccidioides brasiliensis.

The present work focuses on the analysis of cell cycle progression of Paracoccidioides brasiliensis yeast cells under different environmental conditions. We optimized a flow cytometric technique for cell cycle profile analysis based on high resolution measurements of nuclear DNA. Exponentially growing cells in poor-defined or rich-complex nutritional environments showed an increased percentage of daughter cells in accordance with the fungus' multiple budding and high growth rate. During the stationary growth-phase cell cycle progression in rich-complex medium was characterized by an accumulation of cells with higher DNA content or pseudohyphae-like structures, whereas in poor-defined medium arrested cells mainly displayed two DNA contents. Furthermore, the fungicide benomyl induced an arrest of the cell cycle with accumulation of cells presenting high and varying DNA contents, consistent with this fungus' unique pattern of cellular division. Altogether, our findings seem to indicate that P. brasiliensis may possess alternative control mechanisms during cell growth to manage multiple budding and its multinucleate nature.

Analysis of Variance↗
PubMed2006

Incidence of Clostridium difficile-associated diarrhea before and after autologous peripheral blood stem cell transplantation for lymphoma and multiple myeloma.

Diarrhea is a major cause of morbidity and discomfort for patients undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation (APBSCT). There are multiple causes of diarrhea in patients undergoing transplantation including antineoplastic chemotherapy, antimicrobials and infection, including Clostridium difficile as the most common pathogen involved. The purpose of this study was to determine the incidence of C. difficile-associated diarrhea (CDAD) 1 week before and 30 days after APBSCT, and to identify risk factors for the development of CDAD including diagnosis. Two hundred and forty-two patients underwent APBSCT for multiple myeloma and lymphoma between October 1996 and October 2001 in two teaching hospitals. Diarrhea was reported in 157 (64.9%) subjects. One hundred and thirty-five out of the 157 subjects were tested for the presence of C. difficile toxin A. These subjects constitute the study group. The incidence of CDAD was 15%. Two thirds of the patients who developed CDAD had multiple myeloma and one third had lymphoma; this difference did not attain statistical significance. The use of cephalosporins (P = 0.03) and the use of intravenous vancomycin (P = 0.02) were the only identified risk factors associated with the development of CDAD. Patients treated with paclitaxel as part of the mobilization regimen had a lower incidence of CDAD than patients who received hematopoietic growth factor only (P = 0.01).

Adult↗
PubMed2005

The rate of treatment of chronic hepatitis C in patients co-infected with HIV in an urban medical centre.

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection is common. HIV co-infection results in a higher rate of histologic progression and shorter interval to HCV-related cirrhosis. Successful treatment of HCV with interferon-based therapy reduces the morbidity and mortality of patients. Significant factors may limit the availability of treatment in co-infected patients. The rate of treatment of HCV and limiting factors to treatment in a co-infected population in an urban setting were determined. A retrospective review of co-infected patients was conducted at our liver and gastrointestinal (GI) clinics for treatment of HCV from July 2001 to June 2002. Treatment of HCV and reasons for nontreatment were recorded. A total of 104 HCV/HIV co-infected patients were identified. Seventy-two per cent were males. Mean age was 47.2 years (32-72). Seventy-four of the 82 (90%) with identifiable risk factors for HCV infection had a history of intravenous drug use (IVDU). Twenty per cent (21/104) of the total underwent a liver biopsy. Sixty-seven per cent who had a liver biopsy were treated. Overall, sixteen patients were treated. Eighty-eight (85%) patients were not treated for the following reasons: 13 refused treatment, and 75 were ineligible. Of the ineligible patients, 40% were noncompliant with visits, 15% were active substance abusers, 13% had decompensated cirrhosis, 8% had significant active psychiatric conditions and 24% had significant co-morbid disease. A majority of patients co-infected with HCV/HIV had a IVDU history. Most co-infected patients were not eligible for HCV treatment. A majority of noncandidates had potentially modifiable psychosocial factors leading to nontreatment.

Adult↗
PubMed2004

Comparative evaluation of the efficacy and safety of two doses of terbinafine (500 and 1000 mg day(-1)) in the treatment of cutaneous or lymphocutaneous sporotrichosis.

The aim of this study was to evaluate the safety and efficacy of oral terbinafine (500 and 1000 mg day(-1)) in the treatment of cutaneous or lymphocutaneous sporotrichosis. A culture for Sporothrix schenckii was required for inclusion into this multicentre, randomized, double-blind, parallel-group study. Patients received either 250 mg b.i.d. or 500 mg b.i.d. oral terbinafine for up to a maximum of 24 weeks and were assessed up to 24 weeks post-treatment. The main efficacy outcome measure was cure, defined as no lesion and absence of adenopathy at the end of follow-up. Adverse events (AEs), laboratory tests, vital signs and ophthalmological examinations were also assessed. Sixty-three patients (14-85 years of age) were treated with 500 mg day(-1) (n = 28) or 1000 mg day(-1) terbinafine (n = 35). The majority of patients were cured after 12-24 weeks of treatment, and the response was dose-dependent throughout the study and at the end of follow-up. The cure rate was significantly higher in patients treated with 1000 mg day(-1) terbinafine compared with those treated with 500 mg day(-1) terbinafine (87% vs. 52%, respectively; P = 0.004). There were no cases of relapse after 24 weeks of follow-up in the 1000 mg day(-1) terbinafine group, compared with six relapses in the terbinafine 500 mg day(-1) group. Terbinafine was well tolerated and the frequency of drug-related AEs was slightly higher in the 1000 mg treatment group. Both doses of terbinafine were well-tolerated and effective for the treatment of sporotrichosis. The 1000 mg day(-1) terbinafine dose was more efficacious than 500 mg day(-1) in the treatment of cutaneous or lymphocutaneous sporotrichosis.

Adolescent↗
PubMed2004

Separation of Paracoccidioides brasiliensis conidia through percoll gradients.

The conidia of Paracoccidioides brasiliensis are the structures most likely to serve as the infectious propagules of this fungus. This study describes our attempts to purify conidia by eliminating mycelial fragments. Purification was attempted using discontinuous 95% and 60% Percoll gradients with densities of 1.167 and 1.107, respectively, prepared either in 0.15 mol/L PBS or 0.25 mol/L sucrose. The best results were observed with the 95% and 90% gradients in sucrose; with the former, conidial purity ranged from 70.6 to 100%, with a mean of 82.3% and a coefficient of variation (VC) of 11.7. With 90% gradients, purity was achieved between 70.4 and 92.5%. The mean in this case was 80.6% and the VC was 9.2%. The use of two consecutive 95% Percoll gradients in sucrose was tested. The recovery efficiency per plate, which averaged 2.5 x 10(6) conidia per plate with one gradient, increased to 5.1 +/- 1.3 x 10(6) conidia with two gradients. The use of Percoll did not affect the viability of the conidia, which was always > or = 90%. This method allows the preparation of a conidial sample almost free from contamination with mycelial fragments, thus facilitating quantitative determination of cause and effect in in-vivo interactions between P brasiliensis and its hosts.

Centrifugation, Density Gradient↗
PubMed2003

Residual pulmonary abnormalities in adult patients with chronic paracoccidioidomycosis: prolonged follow-up after itraconazole therapy.

Itraconazole effectively controls active paracoccidioidomycosis but appears not to hinder lung fibrosis. Clinical records and chest radiographs from 47 itraconazole-treated patients with prolonged posttherapy follow-up (mean follow-up period, 5.6 years) were analyzed; the radiographs were interpreted following pneumoconiosis standards that consider the lungs as 6 fields and grade damage according to the number of fields involved. Infiltrative lesions were observed at diagnosis in 93.6% of the patients. Fibrosis was observed in 31.8% of the patients at diagnosis and had not cleared at the end of the observation period in any of these patients. Fibrosis also developed de novo in 11 patients (25%), so that by the end of the follow-up period it was seen in 53.2% of patients overall. Fibrosis correlated with severity of infiltrates at diagnosis: fibrosis was present in 83% of patients with very severe infiltration and in 12.5% of patients with minor infiltration. Among patients with severe infiltration, fibrosis was present in 30%; this increased (to 75%) when bullae were concomitantly present at diagnosis. Prompt initiation of treatment is necessary to avoid the development of fibrosis.

Adult↗
PubMed2002

Performance of a hybrid central venous catheter utilized for both peripheral blood stem cell harvest and transplant support of patients undergoing autologous peripheral blood stem cell transplantation.

Patients undergoing autologous peripheral blood stem cell transplantation (PBSC) frequently require the sequential insertion of two central venous catheters, one for leukapheresis and one for transplant support. Hybrid catheters suitable for leukapheresis and long-term use have been increasingly used, but there is limited information regarding their performance and complication rate. The purpose of this study was to determine the performance of the Pheres-Flow hybrid catheter when utilized for both leukapheresis and transplant support, with particular emphasis on the incidence of infectious and occlusive complications. We prospectively analyzed the performance of 92 catheters in 82 consecutive patients who underwent autologous peripheral blood stem cell (PBSC) transplantation. Occlusion was the most frequent complication of this catheter with 29% of the patients experiencing difficulty drawing blood or infusing fluids. Infection was another frequent complication. Twenty-two percent of patients developed catheter-related bloodstream infections and 15 catheters had to be removed because of proven or suspected infection that did not respond to antibiotic therapy. Nevertheless, 77% of patients were able to complete leukapheresis and transplant support with only one catheter. We conclude that the utilization of the Pheres-Flow catheter for both leukapheresis and transplant support is feasible, but that new strategies need to be developed to decrease the incidence of occlusive and infectious complications of hybrid catheters.

Adult↗
PubMed2002

Experimental paracoccidioides brasiliensis infection in mice: influence of the hormonal status of the host on tissue responses.

We have previously proposed that 17beta-estradiol may be responsible in part for the decreased frequency of clinical paracoccidioidomycosis in females via a blocking of the initial morphological transformation necessary to initiate infection. Here we examined the course of infection in male and female mice in relation to their hormonal status. After pulmonary infection with conidia, normal males showed progressive infection, whereas normal females restricted proliferation and progressive disease. In contrast, castrated animals exhibited lesser capacity to restrict disease progression. Castrated male mice reconstituted with 17beta-estradiol initially restricted proliferation, but showed disease progression later in infection, whereas castrated female mice reconstituted with testosterone were unable to restrict disease. Quantitative histological analyses demonstrated that only normal male and castrated reconstituted mice developed granulomas, which decreased in number and size with time correlating with increasing numbers of CFU in the lungs. Greater numbers of chronic inflammatory foci did not correlate with higher CFU. These results further support a role for 17beta-estradiol during early innate resistance of females to paracoccidioidomycosis.

Animals↗
PubMed2001

Paracoccidioidomycosis in Colombia: an ecological study.

The natural habitat of Paracoccidioides brasiliensis, agent of paracoccidioidomycosis (PCM), remains unknown. This study is aimed at establishing associations between the ecological variables present in all Colombian municipalities and the incidence of PCM. Records of 940 patients were studied and several ecological variables analysed, as well as their association to amount of patients per total rural population in each municipality, determined through a multivariate analysis. All 940 patients came from 216 municipalities (20-3%), out of which, 93 were birthplace and place of long-term residence for 121 patients. The Incidence Rate Ratio (IRR) was determined for these 93 municipalities. The following variables fitted the model: altitude from 1,000 to 1,499 metres above sea level (IRR = 6.37), rainfall from 2000 to 2999 mm (IRR = 2.15), presence of humid forests (Holdridge) (IRR = 1.79) and coffee (IRR = 1.95), tobacco (IRR = 3.59) crops. These results indicate that these municipalities constitute reservareas for P. brasiliensis (Borelli).

Altitude↗
PubMed2001

The oral route in the pathogenesis of paracoccidioidomycosis: an experimental study in BALB/c mice infected with P. brasiliensis conidia.

Due to the high frequency of oral mucosal lesions observed in paracoccidioidomycosis patients, it was advocated that the infection was acquired by the traumatic implantation of the etiologic agent Paracoccidioides brasiliensis. Although at present this theory is considered invalid, it has not yet been excluded in experimental studies. In order to determine if intra-oral inoculation could explain the pathogenesis of paracoccidioidomycosis, 64 BALB/c mice were inoculated intra-orally with 850.000 viable P. brasiliensis conidia into the mandibular body. Animals were sacrificed at various time intervals up to 20 weeks and cultures were made from gingiva, lungs, spleen, and liver. Additionally, histopathological studies of the mandibular body were also performed. P. brasiliensis was isolated from all gingival tissues during the interval 24-72 h, indicating that the infection was active. During the 5-10 week period, the infection appeared to have been controlled at the inoculation site as cultures showed a significant reduction in colony forming units (CFU); however, at the 15-20 week period such control was lost and the fungus was recovered once more. Dissemination to other body sites was rare; thus, the lungs were involved in just one animal (2%), the liver in two (3%) and the spleen in seven (11%). The infection became established as proven by positive organ cultures, but the dissemination pattern did not correspond to the one observed in humans. Based on these findings, the intra-oral traumatic route does not appear to mimic the natural history of paracoccidioidomycosis.

Administration, Oral↗
PubMed2001

Creating order out of chaos: models of GNP practice with hospitalized older adults.

It has been well documented that hospitalization of an older adult can trigger a cascade of events that negatively affect quality of life long after hospitalization. Three models of care directed by hospital-based geriatric nurse practitioners (GNPs) are described. The GNPs' roles include primary care provider, consultant, educator, researcher, and/or administrator. In one model, the GNP collaborated with a multi-disciplinary team to create a clinical pathway, the Functional Recovery Pathway. In the second model, the GNP and nurse manager addressed the issue of fall risk with an education program for the staff. As a result, the fall rate decreased 5.8%. In a third model, the GNP coordinated care of hospitalized nursing home residents in a "scatter bed" program. Working synergistically with a case management program, the length of stay for this group of patients decreased from a median of 12 days to 9 days in the first year to 6.8 days in the third year. All three models showed that the GNP facilitate change, improve resource utilization, and create innovative strategies to optimize care for hospitalized elders.

Accidental Falls↗
PubMed2001

The habitat of Paracoccidioides brasiliensis: how far from solving the riddle?

When trying to understand the pathophysiology of any infectious agent, one key piece of information is the determination of its habitat. In the case of Paracoccidioides brasiliensis, the precise location of the fungus' environmental niche remains undefined despite the efforts of various research groups. This review summarizes recent studies on the ecology of P. brasiliensis and certain facets of paracoccidioidomycosis. Studies on the juvenile form of paracoccidioidomycosis in children less than 13 years of age, the characterization of the ecological factors in the 'reservarea' where the infection is acquired and the presence of P. brasiliensis in the nine-banded armadillo (Dasypus novemcinctus), are all helping to pinpoint the microniche of this pathogen. The application of molecular biology techniques based on the amplification of nucleic acids will also hopefully help in establishing the precise habitat of P. brasiliensis.

Adolescent↗
PubMed2001

House calls: is there an APN in the house?

PURPOSE: To report how a group of geriatric advanced practice nurses (APNs) participated in a house calls program that increased access to care for homebound and frail community-dwelling elders. DATA SOURCES: Selected literature and author experiences, illustrated with clinical examples. CONCLUSIONS: Many frail older adults are unable to access healthcare due to functional impairments related to multiple, chronic medical conditions. Many of these adults inappropriately utilize the emergency department for episodic care. IMPLICATIONS FOR PRACTICE: The model of care maximizes utilization of APNs to provide cost effective, culturally sensitive, quality care. The goal of geriatric assessment and primary care in this practice is to add quality to later years of life, promoting dignity and comfort to older adults and their families.

Aged↗
PubMed2001

Detection of melanin-like pigments in the dimorphic fungal pathogen Paracoccidioides brasiliensis in vitro and during infection.

Melanins are implicated in the pathogenesis of several human diseases, including some microbial infections. In this study, we analyzed whether the conidia and the yeasts of the thermally dimorphic fungal pathogen Paracoccidioides brasiliensis produce melanin or melanin-like compounds in vitro and during infection. Growth of P. brasiliensis mycelia on water agar alone produced pigmented conidia, and growth of yeasts in minimal medium with L-3,4-dihydroxyphenylalanine (L-DOPA) produced pigmented cells. Digestion of the pigmented conidia and yeasts with proteolytic enzymes, denaturant, and hot concentrated acid yielded dark particles that were the same size and shape as their propagules. Immunofluorescence analysis demonstrated reactivity of a melanin-binding monoclonal antibody (MAb) with the pigmented conidia, yeasts, and particles. Electron spin resonance spectroscopy identified the yeast-derived particles produced in vitro when P. brasiliensis was grown in L-DOPA medium as a melanin-like compound. Nonreducing polyacrylamide gel electrophoresis of cytoplasmic yeast extract revealed a protein that catalyzed melanin synthesis from L-DOPA. The melanin binding MAb reacted with yeast cells in tissue from mice infected with P. brasiliensis. Finally digestion of infected tissue liberated particles reactive to the melanin binding MAb that had the typical morphology of P. brasiliensis yeasts. These data strongly suggest that P. brasiliensis propagules, both conidia and yeast cells, can produce melanin or melanin-like compounds in vitro and in vivo. Based on what is known about the function of melanin in the virulence of other fungi, this pigment may play a role in the pathogenesis of paracoccidioidomycosis.

Animals↗
PubMed2000

Morphological aspects of Paracoccidioides brasiliensis in lymph nodes: implications for the prolonged latency of paracoccidioidomycosis?

In order to determine if fungal morphology in tissues would furnish indications on the viability of Paracoccidioides brasiliensis yeast cells, lymph node biopsies from five patients with paracoccidioidomycosis, including one with residual circumscribed lesions, were examined. A program that allows transferring of microscopic images to the computer for further processing was used. In the four active cases, the infected lymph nodes had over 49% of healthy-looking yeast cells while in the case of the residual lesion, this figure was smaller (21%). The residual had a larger proportion of aberrant yeast cells, with predominance of shell-like, empty cells (33%) and crescent bodies (30%); balloon-like yeasts were also seen (16%). The last two types of cells were also seen in the active lesions, but in smaller proportions, < or = 8% and < or = 9%, respectively. The number of multiple budding yeast cells, which clearly demonstrate fungal viability, ranged 24-33% in active cases but was only 5% in the residual lesion. Although the number of biopsies examined is small, the results tend to indicate that the morphology of P. brasiliensis yeast cells in walled-off tissues is abnormal and that the number of viable elements is small. There might be a connection between these findings and the long latency period illustrated by those patients with paracoccidioidomycosis that have been diagnosed in non-endemic areas. Additionally, if P. brasiliensis yeast cells were to be subjected to the microaerophilic environment present in walled-off lesions, they would probably require a long time to multiply. Under these circumstances, the mycosis would also need many years to manifest.

Humans↗
PubMed2000

The safety and efficacy of intraoperative heparin in total hip arthroplasty.

A single dose of unfractionated heparin (15 U/kg), administered intravenously before surgery on the femur suppresses thrombogenesis during total hip replacement. Nine hundred eighty-nine patients (1021 hips) who received one dose of intraoperative heparin with hypotensive epidural anesthesia were followed up prospectively for 3 months. Asymptomatic deep vein thrombosis assessed by ultrasound in the first 198 consecutive patients showed an incidence of 7.1% (14 of 198). The incidence of clinical deep vein thrombosis in the subsequent 791 patients was 0.88% (seven of 791). Symptomatic pulmonary embolism occurred in 0.5% (five of 989). No patients died and there was one major bleeding episode. Based on this favorable experience, intraoperative heparin appears safe and efficacious as thromboembolic prophylaxis.

Adult↗