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Biomedical subjects

A Corso

Publications and source records attributed to A Corso.

At least 19 recordsLinked to original sources
PubMed2005

First report of VanA Enterococcus gallinarum dissemination within an intensive care unit in Argentina.

Enterococcusgallinarum is intrinsically resistant to low levels of vancomycin and has been described as a colonizing microorganism causing bacteraemia and infection among immunosupresed patients. Between August 2000 and February 2001, 15 highly glycopeptide-resistant E. gallinarum isolates, one from blood and the remaining from rectal swabs, were recovered in a general hospital of Buenos Aires Province, Argentina. All isolates were characterized by biochemical assays, and displayed MICs of vancomycin in the range 16-128 mg/l and MICs of teicoplanin in the range 16-32 mg/l. In all cases, PCR analysis yield positive results for both vanC1 and vanA genes. E. gallinarum isolates were classified as two clonal types by SmaI-PFGE: clone A (n = 8) and clone B (n = 7) and both harboured a transferable vanA element.

Anti-Bacterial Agents↗
PubMed2005

Efficacy, toxicity and feasibility of a shorter schedule of DCEP regimen for stem cell mobilization in multiple myeloma.

From 2000 to 2004, 152 patients with multiple myeloma aged or=4 x 10(6) cells/kg. The proportion of patients in whom mobilization failed was similar in the two groups. The incidence of WHO grade III neutropenia was higher in group II, although the difference was not statistically significant; the percentage of patients requiring hospitalization for severe infections was similar in the two groups. The incidence of WHO grade IV thrombocytopenia did not differ between the two groups. The response rate was 72% in group I and 80% in group II with similar percentages of patients achieving good responses. DCEP-short is a good mobilizing regimen, sharing the same characteristics as infusional-DCEP: high mobilizing efficacy, low toxicity and good antitumor activity. This new schedule of DCEP does, however, allow complete outpatient management and so could be advantageously included in any high-dose therapy program.

Antigens, CD34↗
PubMed2004

Modification of thrombomodulin plasma levels in refractory myeloma patients during treatment with thalidomide and dexamethasone.

Deep venous thrombosis (DVT) has been variably reported in multiple myeloma patients during treatment with thalidomide alone or in combination with chemotherapy or dexamethasone. With the aim of investigating this complication, we performed, on a cohort of 13 relapsed refractory MM patients treated with low-dose thalidomide (100 mg/day) and dexamethasone (20 mg p.o./day for 4 days every 2 weeks), a serial evaluation of different laboratory parameters implicated in DVT. No significant abnormalities in all genetic, serologic, or plasmatic parameters studied were registered, apart from thrombomodulin which showed significant variations between baseline and 1st-month values and 1st- and 3rd-month values. In conclusion, the evidence of significant variations of thrombomodulin values in the 1st month of therapy, which is considered to involve the highest risk of thrombosis, might support a role for thrombomodulin in this complex mechanism.

Adult↗
PubMed2004

Improvement of a latex agglutination test for the evaluation of oxacillin resistance in coagulase-negative staphylococci.

The "Slidex MRSA Detection" test (Denka Seiken, Japan) is a latex agglutination assay able to detect PBP2a. We evaluated its ability to differentiate mecA-positive from mecA-negative coagulase-negative staphylococci. We included 100 coagulase-negative staphylococci clinical isolates belonging to 9 species, 54 mecA positive and 46 mecA negative, as characterized by PCR. The specificity achieved using the manufacturer's instructions was 100%, but the sensitivity was only 57%. To increase sensitivity, we introduced modifications into the standard protocol. Using either large inocula or oxacillin induction before test performance, we achieved 100% sensitivity.

Latex Fixation Tests↗
PubMed2003

Urinary proteins in multiple myeloma: correlation with clinical parameters and diagnostic implications.

Renal failure is one of the worst complications occurring in multiple myeloma (MM) patients. It does not affect survival if reverted by a prompt chemotherapy before the damage becomes irreversible; therefore, the early diagnosis of renal dysfunction is crucial. High and low molecular weight urinary proteins have proved to be helpful in diagnosing initial renal damage since they are more sensitive than urea and creatinine serum levels or creatinine clearance. We studied the renal function of 111 MM patients through serum creatinine, urea, urinary IgG, alpha(1)-microglobulin (alpha(1)-M), and albumin (Alb). Two successive controls were made in a subset of 30 patients, categorized in three groups (improved, stable, worsened) according to the behavior of tumor burden markers (bone marrow plasmacytosis, monoclonal component, and beta(2)-microglobulin). In every group, we evaluated the behavior of urinary proteins. Renal dysfunction evaluated with serum parameters was present in 19 patients (17%), while if studied with urinary proteins was revealed in 71 patients (64.5%). Urinary proteins statistically correlated with each other. They correlated with creatinine, IgG, and alpha(1)-M also with urea. By contrast, they showed a variable correlation with clinical parameters: alpha(1)-M correlated with bone marrow plasmacytosis (BMPC) ( p=0.02) and beta(2)-M ( p=0.000001), IgG with all three disease parameters (MC p=0.0005, BMPC p=0.009, beta(2)-M p=0.007), and Alb only with beta(2)-M ( p=0.0004). In the subset of 30 patients followed with two successive controls, urinary proteins showed a parallel behavior with the indices of tumor burden. In conclusion, IgG, alpha(1)-microglobulin, and albumin are reliable and sensitive to precociously reveal renal damage, and we recommend their routine use for the definition and monitoring of renal function in multiple myeloma patients, mainly those in early stage, to better identify initial signs of progression.

Adult↗
PubMed2002

Successful therapy with high-dose steroids and cyclosporine for the treatment of carmustine-mediated lung injury.

The treatment of the pulmonary toxicity induced by carmustine is nowadays based on the use of corticosteroids that generally lead to a rapid resolution of pneumonitis. On the contrary, no therapeutic alternatives are reported for those patients who do not respond to steroids. We describe a case of non-Hodgkin's lymphoma in a patient who developed a severe interstitial pneumonitis after an autologous transplantation including carmustine in the conditioning regimen. He was successfully treated with an association of steroids and cyclosporine A with a rapid improvement of symptoms and a complete resolution of pneumonitis. This is, to our knowledge, the first case of carmustine-induced pneumonitis, resistant to steroids alone, successfully treated with cyclosporine A. This suggests an immunoallergic mechanism in the pathogenesis of the damage, which can be reversed with prompt therapy.

Adult↗
PubMed2002

Urinary proteins and renal dysfunction in patients with multiple myeloma.

Besides bone pain, pathologic fractures, anaemia, and recurrent infectious diseases, renal failure is one of the most serious complications in multiple myeloma patients. Its incidence is generally underestimated because of the low reliability of the parameters routinely used for the evaluation of renal dysfunction. Other laboratory tests in the literature are reported to be more suitable to better define the extension of the renal impairment, namely urinary proteins or creatinine clearance. We here report on the clinical implication of urinary parameters in defining the renal function in myeloma patients.

Biomarkers↗
PubMed2001

Consolidation treatment with autologous peripheral blood progenitor cell transplantation in acute myeloid leukemia: a single center experience.

Several trials have suggested that intensive post-remission therapy may prolong the duration of complete remission (CR) in acute myeloid leukemia (AML). The purpose of this study was to evaluate the feasibility and the efficacy of high-dose cytarabine (HiDAC) consolidation chemotherapy followed by high-dose therapy and autologous infusion of peripheral blood progenitor cells (PBPC) mobilized by G-CSF in adult patients with AML in first CR. Fifteen consecutive AML patients underwent HiDAC consolidation chemotherapy, used as a method of in vivo purging, followed by G-CSF for the purpose of autologous PBPC collection. Eleven patients collected a median of 6.9x10(8)/kg peripheral blood mononuclear cells (MNC) (range 2.9-23) and a median of 6.67x10(6)/kg CD34+ cells (range 1.8-33.5) with a median of two aphereses (range 1-3). Two patients did not mobilize and two obtained an inadequate number of progenitor cells. The 11 patients with adequate collections received myeloablative chemotherapy followed by the infusion of PBPC. The median number of days to recover neutrophils and platelets was 12 and 13, respectively. After a median follow-up of 28.7 months (range 17.2-43.4), five out of 11 patients who underwent PBPC transplantation are still in CR, five have died in first relapse and one is alive in CR after relapse treated with salvage therapy and second PBPC infusion. These results demonstrate that HiDAC consolidation chemotherapy followed by autologous PBPC transplantation is a feasible procedure with minimal toxicity. Randomized studies should be performed to evaluate whether this form of consolidation may produce a significant improvement in leukemia-free survival.

Acute Disease↗
PubMed2001

DCEP (dexamethasone, cyclophosphamide, etoposide, and cisplatin) is an effective regimen for peripheral blood stem cell collection in multiple myeloma.

DCEP (dexamethasone, cyclophosphamide, etoposide, and cisplatin) has proved to be an effective salvage therapy for refractory-relapsed MM patients. Little is known, however, about its potential as mobilizing therapy. The aim of this study was to evaluate the efficacy of DCEP in mobilizing PBSC and to define its toxicity. Fifty-five MM patients received DCEP followed by G-CSF as part of high-dose programs including autologous transplantation. At the time of mobilization, 40 patients had previously received VAD only, and 15 alkylating agents. Mobilization was successful (minimum number of CD34(+) cells 2 x 10(6)/kg) in 48/55 patients (87%), and 41/55 patients (75%) collected >4 x 10(6)/kg CD34(+) cells. Of the seven patients who did not mobilize stem cells, five (71%) had been previously exposed to alkylating agents. The median number of CD34(+) cells harvested was 5.8 x 10(6)/kg (range 2.1-22.4). There was no treatment-related mortality. The side-effects of DCEP were always tolerable. No neutropenia <1000/microl nor thrombocytopenia <50,000/microl were observed. No patient required transfusion as a consequence of therapy, or hospitalization for septic complications. In conclusion, DCEP, in addition to its demonstrated anti-tumor activity, is an effective regimen for mobilizing peripheral blood progenitor cells in myeloma patients, with little or no side-effects. These properties render DCEP a useful regimen for the debulking and mobilization phase of high-dose programs for multiple myeloma.

Adult↗
PubMed2001

Penicillin-resistant Streptococcus pneumoniae in metropolitan New York hospitals: case control study and molecular typing of resistant isolates.

During the 4-month period from January to April, 1998, 476 patients with Streptococcus pneumoniae infections were detected in 12 metropolitan New York hospitals and 112 penicillin-resistant (PRP) isolates (24%) were identified in 11 institutions. A case control study of 100 patients with penicillin-resistant and susceptible pneumococci from four of the widely dispersed hospitals revealed a high incidence of underlying medical illnesses in adult patients (74%), a preponderance of patients with pneumonia (63%), and a majority of patients who had underlying risk factors for pneumonia or invasive disease (51%). In this limited case control study, no difference was noted between cases and controls regarding known risk factors for penicillin-resistant pneumococcal infections. The percentage of single-patient PRP isolates varied among individual hospitals but the mean percentages of PRP from the four participating University Medical Centers and seven community hospitals were similar: 26% and 22% respectively. By E-test, 60% and 26% were high-level penicillin and ceftriaxone resistant, respectively. Pulsed-field gel electrophoresis identified 26 chromosomal macrorestriction patterns among the 103 PRP isolates available for analysis, but almost half (50 isolates or 48%) of these belong to two drug-resistant internationally spread clones, SP(23)-1 and SP(9/14)-3, that were detected in all hospitals and were recovered from invasive and noninvasive sites in both children and adults.

Adolescent↗
PubMed2001

Antibiotic resistance in Streptococcus pneumoniae in six Latin American countries: 1993-1999 surveillance.

The impact of invasive pneumococcal invasive disease is increased by the emergence of antibiotic resistance. We report regional and temporal variations in antibiotic resistance for 4,105 invasive Streptococcus pneumoniae isolates collected from Latin American children <5 years, between 1993 and 1999. Reduced susceptibility to penicillin was detected in 1,182 isolates (28.8%); 36% of these were resistant (> or = 2 microg/ml), including 12.6% with MIC > or = 4 microg/ml, occurring primarily in serotypes 14 and 23F. Reduced susceptibility to third-generation cephalosporins was detected in 12.1% of the collection. Mexico had the highest proportion of reduced susceptibility to penicillin (51.6%) and to third-generation cephalosporins (22%), whereas Brazil had the lowest at 20.9% and 0.7%, respectively. Isolates cultured from patients with pneumonia were more likely to have reduced susceptibility to third-generation cephalosporins than isolates from patients with meningitis (p < 0.0001). Susceptibility to trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, and vancomycin was tested by disk diffusion for 2.899 isolates. Reduced susceptibility was observed for 45.6%, 11.5%, 6.9%, and 0%, respectively. Thirty-one percent of the strains were resistant to > or = 2 drugs. High levels of antibiotic resistance in Latin America emphasize the need for the development of and adherence to rational antibiotic use guidelines. On-going surveillance will monitor the impact of these programs.

Age Factors↗
PubMed2001

Evolution of Streptococcus pneumoniae serotypes and penicillin susceptibility in Latin America, Sireva-Vigía Group, 1993 to 1999. PAHO Sireva-Vigía Study Group. Pan American Health Organization.

BACKGROUND: Since 1993 the Pan American Health Organization has coordinated a surveillance network with the National Reference Laboratories of Argentina, Brazil, Chile, Colombia, Mexico and Uruguay aimed at monitoring capsular types and antimicrobial susceptibility of Streptococcus pneumoniae causing invasive disease in children <6 years of age. METHODS: The surveillance system included children 6 years of age and younger with invasive disease caused by S. pneumoniae. The identification, capsular typing and susceptibility to penicillin of the isolates were conducted using a common protocol, based on standard methodologies. RESULTS: By June, 1999, 4,105 invasive pneumococcal isolates had been collected mainly from pneumonia (44.1%) and meningitis (41.1%) cases. Thirteen capsular types accounting for 86.1% of the isolates (14, 6A/6B, 5, 1, 23F, 19F, 18C, 19A, 9V, 7F, 3, 9N and 4) remained the most common types during the surveillance period. Diminished susceptibility to penicillin was detected in 28.6% of the isolates, 17.3% with intermediate and 11.3% with high level resistance. Resistance varied among countries and increased during this period in Argentina, Colombia and Uruguay. Serotypes 14 and 23F accounted for 66.6% of the resistance. CONCLUSION: These surveillance data clearly demonstrate the potential impact of the introduction of a conjugate vaccine on pneumococcal disease and the need for more judicious use of antibiotics to slow or reverse the development of antimicrobial resistance.

Child↗
PubMed2001

Biochemical markers of bone disease in asymptomatic early stage multiple myeloma. A study on their role in identifying high risk patients.

BACKGROUND AND OBJECTIVES: Skeletal involvement is typical of multiple myeloma (MM) and its occurrence increases with the progression of the disease. We performed a study to evaluate the clinical importance of osteocalcin (bone gla-protein, BGP) and bone alkaline phosphatase (b-AP) as indices of osteoblastic activity, and deoxypyridoline (DPD) as a marker of bone resorption. DESIGN AND METHODS: Fifty-two MM patients, 39 patients with monoclonal gammopathy of undetermined significance (MGUS), and 30 normal controls entered the study. Of the 52 MM patients, 10 showed lytic lesions at standard X-rays and 42 did not; 21 were untreated and 31 had been treated with chemotherapy (combined with bisphophonates in 15). Of these last, 12 had progressive disease and 19 were in plateau phase. RESULTS: DPD levels were higher in MM patients than in patients with MGUS or healthy controls (p = 0.0001 and p = 0.0008, respectively). No statistical differences were seen between patients with MGUS and healthy controls. BGP serum levels were significantly lower in MM patients than in MGUS patients (p = 0.001) or healthy controls (p = 0.001). b-AP was significantly higher in MGUS patients than in MM patients (p = 0.04). Biochemical parameters were analyzed in a continuous fashion and after dichotomization into low and high values with respect to normal ones. Abnormal high values of DPD showed statistically significant correlations with presence of osteolysis (p = 0.008), advanced stage (p = 0.03) and abnormal beta2-microglobulin (beta2M) values (p = 0.03), while DPD as a continuous variable correlated significantly only with the presence of osteolysis (p = 0.02). In contrast, neither BGP nor b-AP showed statistical correlations with the presence of lytic lesions, or with other clinical or laboratory parameters. In 15 patients followed with serial controls, modifications of DPD levels reflected bone disease status well. Of the 42 patients without radiologic evidence of skeletal lesions, 15 had abnormal DPD values. Spinal magnetic resonance imaging (MRI) showed initial lytic lesions in 10 of them. INTERPRETATION AND CONCLUSIONS: Biochemical markers of bone metabolism are useful in evaluating and monitoring skeletal involvement in MM patients. They may help clinicians to identify: 1) from among patients without radiologic evidence of lytic lesions, those who deserve more accurate radiologic examinations (namely MRI); 2) from among asymptomatic patients, and in association with spinal MRI, those patients at higher risk of progression who might benefit from early treatment.

Adult↗
PubMed2000

Blood stem cell collections in multiple myeloma: definition of a scoring system.

The purpose of the study was to identify factors that could predict good yields of peripheral blood stem cells (PBSC) in multiple myeloma (MM). Fifty-one MM patients, nine with refractory disease and 42 in plateau phase, were mobilized with high-dose cyclophosphamide (HD-Cy) at 4 g/m2 followed by granulocyte colony-stimulating factor (G-CSF) 5 microg/kg/day. Clinical and laboratory parameters at the time of mobilization were analyzed for correlations with the number of CD34+ cells collected, with the colony-forming unit granulocyte-macrophage (CFU-GM) count, and the mononuclear cell (MNC) count. In univariate analysis, low WBC count, low platelet count, prior exposure to melphalan, and an interval >6 months from the start of treatment correlated with poor yields of CD34+ cells. Low platelet count, prior exposure to melphalan or to radiotherapy, and an interval >6 months from the start of treatment were associated with a low CFU-GM count. On the basis of these data, we defined a scoring system able to predict the yield of the mobilizing procedure. According to this system, the presence of more than one risk factor (low WBC and platelet counts, prior exposure to melphalan, interval from first chemotherapy >6 months) was predictive of insufficient collections when a conventional combination of mobilizing measures are used.

Adult↗
PubMed2000

Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains.

Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations. In spite of its high resolving power, use of the method has been hampered by inadequate laboratory-to-laboratory reproducibility. In the project described here we have addressed this problem by organizing a multilaboratory effort in which the same bacterial strains (subtype variants of the Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed by twenty investigators in thirteen different laboratories according to an indentical protocol, which is reproduced here in detail. PFGE patterns obtained were analyzed at a central laboratory in order to identify specific technical problems that produced substandard macrorestriction patterns. The results including the specific technical problems and their most likely causes are described in this communication. Also listed are seven major epidemic clones of MRSA which have been characterized by molecular fingerprinting techniques and the prototypes of which have been deposited at the American Type Culture Collection, from where they will be available for interested investigators for the purpose of typing MRSA isolates. It is hoped that this communication will contribute to the improvement of the reproducibility and technical/aesthetic quality of PFGE analysis.

Bacterial Typing Techniques↗