Milton Artur Ruiz

Epidemiology of bacteremia and factors associated with multi-drug- resistant gram-negative bacteremia in hematopoietic stem cell transplant recipients

The incidence of Gram-negative bacteremia has increased in hematopoietic stem cell transplant (HSCT) recipients. We prospectively collected data from 13 Brazilian HSCT centers to characterize the epidemiology of bacteremia occurring early post transplant, and to identify factors associated with infection due to multi-drug-resistant (MDR) Gram-negative isolates. MDR was defined as an isolate with resistance to at least two of the following: third- or fourth-generation cephalosporins, carbapenems or piperacillin-tazobactam. Among 411 HSCT, fever occurred in 333, and 91 developed bacteremia (118 isolates): 47% owing to Gram-positive, 37% owing to Gram-negative, and 16% caused by Gram-positive and Gram-negative bacteria. Pseudomonas aeruginosa (22%), Klebsiella pneumoniae (19%) and Escherichia coli (17%) accounted for the majority of Gram-negative isolates, and 37% were MDR. These isolates were recovered from 20 patients, representing 5% of all 411 HSCT and 22% of the episodes with bacteremia. By multivariate analysis, treatment with third-generation cephalosporins (odds ratio (OR) 10.65, 95% confidence interval (CI) 3.75–30.27) and being at one of the hospitals (OR 9.47, 95% CI 2.60–34.40) were associated with infection due to MDR Gram-negative isolates. These findings may have important clinical implications in the decision of giving prophylaxis and selecting the empiric antibiotic regimen.

Micronucleus monitoring to assess human occupational exposure to organochlorides

Health surveillance for hazardous situations due to chemical exposure, in particular those which are carcinogenic, requires sensitive monitoring tests. Although experimental studies have shown the genotoxic and carcinogenic effect of several organochlorides, the lack of epidemiologic studies prevents their classification as carcinogenic to human beings. In this context, genotoxicity tests of short duration in human cells gain importance. The relation between the clastogenic effects (chromosome breaks) and cancer induction is already known to the scientific literature. The micronucleus test has been proposed as a good indicator of clastogenesis. In the present study, we evaluated, by means of the micronucleus test, 41 workers of a chemical industry in the state of São Paulo, southeast region of Brazil, who had been exposed to a mixture of chlorinated solvents (carbon tetrachloride, perchloroethylene, and hexachlorobenzene) and 28 workers who had not been exposed. Peripheral lymphocytes stimulated by phytohemagglutinin and with cytokinesis blocked by cytochalasin B were used. The results showed that the exposed workers presented a statistically significant higher frequency of micronuclei than the group which had not been exposed. Environ. Mol. Mutagen. 29: 46–52, 1997

ABO, Lewis, secretor and non-secretor phenotypes in patients infected or uninfected by the Helicobacter pylori bacillus

CONTEXT Epidemiological studies have demonstrated higher frequencies of the O blood group and the non-secretor phenotype of ABH antigens among patients suffering from peptic ulcers. Since Helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the ABO and Lewis blood group phenotypes and secretor and non-secretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. OBJECTIVE To verify the frequencies of ABO, Lewis blood group phenotypes, secretor and non-secretor phenotypes in patients infected or uninfected by H. pylori. DESIGN Cross-sectional study. SETTING Outpatient clinic. PARTICIPANTS One hundred and twenty patients with dyspeptic symptoms who underwent endoscopy. MAIN MEASUREMENTS ABO and Lewis blood group phenotypes were determined by a standard hemagglutination test and the secretor and non-secretor phenotypes were evaluated by saliva samples using the inhibitor hemagglutination test. RESULTS The diagnosis of infection, made via breath and urea tests and confirmed using polymerase chain reaction (PCR) in gastric biopsy fragments, showed the presence of H. pylori in 61.7% of the patients and absence in 38.3%. The differences between the frequencies of the ABO blood group phenotypes among infected (A 27.0%; B 12.2%; AB 4.0% and O 56.8%) and uninfected patients (A 58.7%; B 13.0%; AB 4.3% and O 24.0%) were significant. The Lewis blood type, secretor and non-secretor phenotypes showed homogeneous distribution between the groups of patients analyzed. CONCLUSIONS Our results suggest that the infection of H. pylori can be related to ABO blood groups but not to the Lewis blood group nor to secretor and non-secretor phenotypes.

Addition of low-dose busulfan to cyclophosphamide in aplastic anemia patients prior to allogeneic bone marrow transplantation to reduce rejection

Summary:Busulfan was added at the dose of 4 mg/kg to 200 mg/kg cyclophosphamide in 81 patients (3–53 years, median 24) with aplastic anemia to reduce graft rejection. Graft-versus-host disease (GVHD) prophylaxis comprised cyclosporine–methotrexate. The number of prior transfusions was 0–276 (median 26), and 48% had received prior immunosuppressive therapy. Two patients experienced primary graft failure, and 10 secondary rejection at 28–1001 days (median 317 days). The cumulative incidence of rejection was 22%; for heavily transfused patients (⩾50 U) it was 43% compared to 16% for the rest (P=0.06). Overall survival rate at 8 years was 56%; patients who received ⩽15 and >15 transfusions was 78 and 50%, respectively (P=0.01), whereas it was 67 and 28% for ⩽50 and >50 transfusions, respectively (P=0.002). In multivariate analysis, higher number of prior transfusions, shorter period of immunosuppression with cyclosporine and GVHD were associated with inferior survival; moreover, a higher risk of graft rejection were associated with a higher number of prior transfusions and a trend was observed for a shorter cyclosporine administration. Low-dose busulfan is feasible and may be helpful in patients exposed to <50 transfusions. However, rejection remains a significant problem, mainly in heavily transfused patients.

Journal impact factor: this editorial, academic and scientific influence

In this report the authors present information on the bibliometric instruments and their importance in measuring the quality of scientific journals and researchers. They in particular the history and deployment of the impact factor of the existing Institute for Scientific Information since 1955. Are presented and discussed the criticism regarding the inadequacy of the impact factor for evaluation of scientific production, misuse and strategies editorial handling of the bibliometric index. It is presented to the new classification CAPES for the journals, based on various criteria and the impact factor and its influence on national scientific and academic life. The authors conclude that, despite all obstacles and discussions, the impact factor of the Institute for Scientific Information is still an useful tool and the only isolation available to assess the scientific and intellectual productivity.

Anemia falciforme: objetivos e resultados no tratamento de uma doença de saúde pública no Brasil: [editorial]

Neste fasciculo organizado e conduzido pelo co-editorRodolfo Delfini Cancado, produto de um evento de granderepercussao nacional sobre anemia falciforme, discutem-seas varias nuances clinicas e hematologicas sobre o tema.A anemia falciforme, do ponto de vista historico, e doconhecimento da humanidade desde os tempos imemoriais econstatadas como secular na Africa pelo habito existente emdiversas tribos do continente de tatuar os portadores e ospacientes para identificar a doenca. O primeiro relato em rela-cao a doenca ocorreu nos Estados Unidos da America emnecropsias de pacientes nos quais se identificou agenesiaesplenica em afro-americano com antecedentes clinicos cro-nicos similares ao da anemia falciforme.

p63 Protein expression in high risk diffuse large B-cell lymphoma

Background: p63 gene is a p53 homologue that encodes proteins with transactivation, DNA-binding and tetramerisation domains. The isoforms TAp63 and TAp73 transactivate p53 target genes and induce apoptosis, whereas the isoforms ΔNp63 and ΔNp73 lack transactivation and might have dominant-negative effects in p53 family members. p63 is expressed in germinal centre lymphocytes and can be related to the development of the lymphoma, but the prognostic significance of its expression in the survival of patients with diffuse large B-cell lymphoma (DLBCL) remains unclear. Aims: To determine whether quantitative immunohistochemical (IHC) analysis of p63 protein expression correlates with CD10 antigen, Bcl-6 antigen and IRF4 antigen expression and to determine whether p63 is a surrogate predictor of overall survival in high–intermediate and high risk DLBCL populations. Methods: CD10, Bcl-6 and IRF4 expression were retrospectively evaluated by IHC in 73 samples of high–intermediate and high risk DLBCL and were used to divide the lymphomas into subgroups of germinal centre B-cell-like (GCB) and activate B-cell-like (ABC) DLBCL. Similarly, p63 expression was evaluated by IHC and the results were compared with subgroups of DLBCL origin and with the survival rates for these patients. Results: p63 was expressed in more than 50% of malignant cells in 11 patients and did not show correlation with subgroups of GCB-like DLBCL or ABC-like DLBCL, but p63(+) patients had better disease-free survival (DFS) than those who were negative (p = 0.01). Conclusions: p63(+) high–intermediate and high risk DLBCL patients have a better DFS than negative cases.

Variability of subjective classifications of corneal topography maps from LASIK candidates

PURPOSE To evaluate the variability of subjective corneal topography map classification between different experienced examiners and the impact of changing from an absolute to a normative scale on the classifications. METHODS Preoperative axial curvature maps using Scheimpflug imaging obtained with the Pentacam HR (Oculus Optikgeräte, Wetzlar, Germany) and clinical parameters were sent to 11 corneal topography specialists for subjective classification according to the Ectasia Risk Scoring System. The study population included two groups: 11 eyes that developed ectasia after LASIK and 14 eyes that had successful and stable LASIK outcomes. Each case was first reviewed using the absolute scale masked to the patient group. After 3 months, the same cases were represented using a normative scale and reviewed again by the same examiners for new classifications masked to the patient group. RESULTS Using the absolute scale, 17 of 25 (68%) cases had variations on the classifications from 0 to 4 for the same eye across examiners, and the overall agreement with the mode was 60%. Using the normative scale, the classifications from 11 of 25 (44%) cases varied from 0 to 4 for the same eye across examiners, and the overall agreement with the mode was 61%. Eight examiners (73%) reported statistically higher scores (P < .05) when using the normative scale. Considering all 550 topographic analyses (25 cases, 11 examiners, and two scales), the same classification from the two scales was reported for 121 case pairs (44%). CONCLUSION There was significant inter-observer variability in the subjective classifications using the same scale, and significant intra-observer variability between scales. Changing from an absolute to a normative scale increased the scores on the classifications by the same examiner, but significant inter-observer variability in the subjective interpretation of the maps still persisted.

The influence of hydroxyurea on oxidative stress in sickle cell anemia

Objective The oxidative stress in 20 sickle cell anemia patients taking hydroxyurea and 13 sickle cell anemia patients who did not take hydroxyurea was compared with a control group of 96 individuals without any hemoglobinopathy. Methods Oxidative stress was assessed by thiobarbituric acid reactive species production, the Trolox-equivalent antioxidant capacity and plasma glutathione levels. Results Thiobarbituric acid reactive species values were higher in patients without specific medication, followed by patients taking hydroxyurea and the Control Group (p < 0.0001). The antioxidant capacity was higher in patients taking hydroxyurea and lower in the Control Group (p = 0.0002 for Trolox-equivalent antioxidant capacity and p < 0.0292 for plasma glutathione). Thiobarbituric acid reactive species levels were correlated with higher hemoglobin S levels (r = 0.55; p = 0.0040) and lower hemoglobin F concentrations(r = -0.52; p = 0.0067). On the other hand, plasma glutathione levels were negatively correlated with hemoglobin S levels (r = -0.49; p = 0.0111) and positively associated with hemoglobin F values (r = 0.56; p = 0.0031). Conclusion Sickle cell anemia patients have high oxidative stress and, conversely, increased antioxidant activity. The increase in hemoglobin F levels provided by hydroxyurea and its antioxidant action may explain the reduction in lipid peroxidation and increased antioxidant defenses in these individuals.

Transplante de Células-tronco marcadas para o miocárdio de paciente com doença de chagas

Stem cell transplantation is a new therapy applied to produce cardiac regeneration through differentiation or increase of heart myocytes or neovascular proliferation in patients in the end stage of congestive heart failure secondary to dilated cardiomyopathy, but the results are still unknown.