Leishmanicidal activity of the venoms of the Scorpions Brotheas amazonicus and Tityus metuendus

Leishmaniasis is a vector-transmitted zoonosis caused by different species of the genus Leishmania, with a wide clinical spectrum. It is a public health problem aggravated by a series of limitations regarding treatment. In the search for new therapeutic alternatives, scorpion venoms are a source of multifunctional molecules that act against the natural resistance of pathogens. This work evaluated the antileishmanial potential of Brotheas amazonicus and Tityus metuendus venoms against the promastigote forms of Leishmania amazonensis e Leishmania guyanensis. The venoms of B. amazonicus and T. metuendus were evaluated for their constituents using Fourier Transform Infrared (FTIR). Growth inhibition and death of promastigotes were evaluated in the presence of diferente crude venom concentrations (100 µg/mL, 50 µg/mL, 10 µg/mL, 1 µg/mL) after one hour of incubation at 25 °C. The FTIR spectra of both venoms exhibited bands in approximate regions, revealing that both exhibit similar functional groups. Crude venom from both scorpion species showed similar or superior leishmanicidal effects to the standart drug N-methylglucamine antimoniate. At the highest concentration of 100 µg/mL, cultures of L. guyanensis treated with the venom of B. amazonicus showed the highest mortality percentages, above 28%, while T. metuendus venom showed the highest activity against L. amazonensis, with mortality above 7%. This preliminar study demonstrates that B. amazonicus and T. metuendus venoms can be important tools in the search for new drugs Against leishmaniasis. Next step involves evaluating the activity against the amastigote forms and purifying the venom proteins in order to identify the best anti-leishmania candidates.

Crude Mortality Associated With the Empirical Use of Polymyxins in Septic Patients in a Setting of High Prevalence of Carbapenem-Resistant Gram-negative Bacteria: Retrospective Analysis of a Cohort

BACKGROUND

Our aim in this retrospective cohort study was to assess the impact on mortality of the empirical use of polymyxin as therapy for carbapenem-resistant gram-negative bacteria (CR-GNB) in septic patients. The study was performed at a tertiary academic hospital in Brazil, from January 2018 to January 2020, the pre-coronavirus disease 2019 period.

METHODS

We included 203 patients with suspected sepsis. The first doses of antibiotics were prescribed from a "sepsis antibiotic kit", which contained a selection of drugs, including polymyxin, with no preapproval policy. We developed a logistic regression model to assess risk factors associated with 14-day crude mortality. Propensity score for polymyxin was used to control biases.

RESULTS

Seventy (34%) of 203 patients had infections with at least 1 multidrug-resistant organism isolated from any clinical culture. Polymyxins in monotherapy or in combination therapy were prescribed to 140 of the 203 (69%) patients. The overall 14-day mortality rate was 30%. The 14-day crude mortality was associated with age (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 1.01-1.05; P = .01), SOFA (sepsis-related organ failure assessment) score value (aOR, 1.2; 95% CI, 1.09-1.32; P < .001), CR-GNB infection (aOR, 3.94; 95% CI, 1.53-10.14; P = .005), and time between suspected sepsis and antibiotic administration (aOR, 0.73; 95% CI, .65-.83; P < .001). The empirical use of polymyxins was not associated with decreased crude mortality (aOR, 0.71; 95% CI, .29-1.71; P = .44).

CONCLUSIONS

Empirical use of polymyxin for septic patients in a setting with high CR-GNB prevalence was not associated with decreased crude mortality.

Influence of Mechanical Cycling on Torque Values of Tapped-In and Screw-In Implant-Supported Crowns

This study investigated the influence of mechanical cycling on screwed-in and tappedin implants restored with screw-retained metallic crowns. Three implant-abutmentcrown systems were evaluated: T1 (multi abutment) and T2 (standard abutment) received tapped-in abutments and S received a screwed-in abutment. The specimens were subjected to two million cycles of 0-150 N load, at 2 Hz, 30° inclination in a dry medium, and torque evaluation. Survival and removal torque were analyzed using chisquare, ANOVA, followed by Tukey's test. Differences between installation and removal torque were determined using a T-test for dependent samples. Analyses were performed in SPSS, considering α = 0.05. All specimens survived mechanical cycling in S, 40% in T1, 80% in T2 (p=0.008). Failures occurred due to loosening of the crown screw. A significant decrease in torque (p=0.000) was found. Group T1 had the lowest removal torque (1.6 ± 0.84 N.Cm²), followed by T2 (3 ± 1.49 N.Cm²) and S (6.3 ± 1.16 N. Cm²), and a statistical difference was found between Groups T1 and S. Both types of implantabutment connections were stable and can be considered for rehabilitative treatment, but failure and removal torque were influenced by the design of prosthetic abutment. Crowns were more susceptible to becoming loose in tapped-in systems.

Lifestyle improvement reduces the consumption of ultra-processed foods in adults with metabolic syndrome

BACKGROUND AND AIMS

The high consumption of ultra-processed products is a concern because it is positively associated with the incidence of chronic non-communicable diseases, as metabolic syndrome (MetS). The aim is to evaluate the effects of three different interventions to modify lifestyle on the consumption of ultra-processed foods in adults with MetS.

METHODS AND RESULTS

This was a randomized clinical trial, in which the participants were divided into three groups: Standard Intervention (SI), Group Intervention (GI) and Individual Intervention (II). The interventions were carried out over a three-month period and the data was collected in a 24-h food record, taken at the beginning and end of the intervention. The food they ate was classified into four groups according to the degree of processing (unprocessed or minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed foods) in accordance with the NOVA food classification. Seventy adults took part in the study with a mean age of 51.2 ± 6.6 years old; most of whom were female (55.7%). The amount of ultra-processed food consumed by the three groups (SI, GI and II) was significantly reduced (46%, 34%, and 33%, respectively). The amount of processed food consumed only reduced in the II group. The Total Energy Value (TEV) consumed by the SI and II groups decreased.

CONCLUSIONS

The interventions that were intended to alter lifestyles were able to reduce the amount of ultra-processed food consumed, which can have an impact on the prevention and treatment of MetS.

REGISTRATION

registered in the Brazilian Registry of Clinical Trials, ReBEC, under number: RBR-9wz5fc.

A role of Na+, K+ -ATPase in spatial memory deficits and inflammatory/oxidative stress after recurrent concussion in adolescent rats

Sports-related concussions are particularly common during adolescence, and there is insufficient knowledge about how recurrent concussions in this phase of life alter the metabolism of essential structures for memory in adulthood. In this sense, our experimental data revealed that seven recurrent concussions (RC) in 35-day-old rats decreased short-term and long-term memory in the object recognition test (ORT) 30 days after injury. The RC protocol did not alter motor and anxious behavior and the immunoreactivity of brain-derived neurotrophic factor (BDNF) in the cerebral cortex. Recurrent concussions induced the inflammatory/oxidative stress characterized here by increased glial fibrillary acidic protein (GFAP), interleukin 1β (IL 1β), 4-hydroxynonenal (4 HNE), protein carbonyl immunoreactivity, and 2',7'-dichlorofluorescein diacetate oxidation (DCFH) levels and lower total antioxidant capacity (TAC). Inhibited Na⁺,K⁺-ATPase activity (specifically isoform α_2/3) followed by K_m (Michaelis-Menten constant) for increased ATP levels and decreased immunodetection of alpha subunit of this enzyme, suggesting that cognitive impairment after RC is caused by the inability of surviving neurons to maintain ionic gradients in selected targets to inflammatory/oxidative damage, such as Na,K-ATPase activity.

In silico, in vitro, and ex vivo studies of the toxicological and pharmacological properties of the flavonoid 5,7-dihydroxy-3,8,4'-trimethoxy

Phytochemical studies of the species Pavonia glazioviana were performed. Quercetin, kaempferol, acacetin, and trimethoxylated flavonoid compounds (which present biological activity) were isolated. We aimed to evaluate the in silico, in vitro, and ex vivo toxicity of flavonoid 5,7-dihydroxy-3,8,4'-trimethoxy (Pg-1) obtained from P. glazioviana through chemical structure analyses, toxicity assessment, and predictive bioactive properties, using human samples in in vitro tests. In silico analysis suggested that Pg-1 presents a good absorption index for penetrating biological membranes (for oral bioavailability), while also suggesting potential antimutagenic, anticarcinogenic, antioxidant, antineoplastic, anti-inflammatory, anti-hemorrhagic, and apoptosis agonist bioactivities. Assessment of hemolytic and genotoxic effects revealed low hemolysis rates in red blood cells with no cellular toxicity in oral mucosa cells. The reduced cytotoxic activity suggested the safety of the concentrations used (500-1000 µg/mL), and demonstrated the varied interactions of Pg-1 with the analyzed cells. The data obtained in the present study suggested potential therapeutic application, and the non-toxic profile indicated viability for future studies.

Fosfomycin in severe infections due to genetically distinct pan-drug-resistant Gram-negative microorganisms: synergy with meropenem

Background

In vitro and clinical studies using parenteral fosfomycin have suggested the possibility of using this drug against infections caused by MDR microorganisms. The aim of this study was to describe a case series of patients treated with fosfomycin who had severe infections caused by pan-drug-resistant Gram-negative bacteria.

Methods

We describe a prospective series of cases of hospitalized patients with infections caused by Gram-negative bacteria resistant to β-lactams and colistin, treated with 16 g of fosfomycin daily for 10-14 days. Isolates were tested for antimicrobial susceptibility and synergism of fosfomycin with meropenem. We tested for resistance genes and performed typing using PCR and WGS.

Results

Thirteen patients received fosfomycin (seven immunosuppressed); they had bloodstream infections (n = 11; 85%), ventilator-associated pneumonia (n = 1; 8%) and surgical site infection (n = 1; 8%), caused by Klebsiella pneumoniae (n = 9), Serratia marcescens (n = 3) and Pseudomonas aeruginosa (n = 1). Overall, eight (62%) patients were cured. Using time-kill assays, synergism between fosfomycin and meropenem occurred in 9 (82%) of 11 isolates. Typing demonstrated that K. pneumoniae were polyclonal. Eight patients (62%) had possible adverse events, but therapy was not discontinued.

Conclusions

Fosfomycin may be safe and effective against infections caused by pan-drug-resistant Gram-negative microorganisms with different antimicrobial resistance mechanisms and there seems to be synergism with meropenem.

Bloodstream infection in hematopoietic stem cell transplantation outpatients: risk factors for hospitalization and death

We described 235 bloodstream infection (BSI) episodes in 146 hematopoietic stem cell transplantation (HSCT) outpatients and evaluated risk factors for hospitalization and death. Records of outpatients presenting with positive blood cultures over a 5-year period (January 2005 to December 2008) were reviewed. Variables with p< 0.1 in bivariate analysis were used in a regression logistic model. A total of 266 agents were identified, being 175 (66.7%) gram-negative, 80 (30.3%) gram-positive bacteria and 9 (3.4%) fungi. The most common underlying disease was acute leukemia 40 (27.4%), followed by lymphoma non-Hodgkin 26 (18%) and 87 patients (59.6%) were submitted to allogeneic hematopoietic stem cell transplant (HSCT). BSI episodes were more frequent during the first 100 days after transplantation (183 or 77.8%), and ninety-one (38.7%) episodes of BSI occurred up to the first 30 days. Hospitalization occurred in 26% of the episodes and death in 10% of cases. Only autologous HSCT was protector for hospitalization. Although, central venous catheter (CVC) withdrawal and the Multinational Association of Supportive Care in Cancer (MASCC) score up to 21 points were protector factors for death in the bivariate analysis, only MASCC remained as protector.

Implementation of tailored interventions in a statewide programme to reduce central line-associated bloodstream infections

BACKGROUND

There have been few studies exploring implementation strategies to central line-associated bloodstream infections (CLABSIs) in low- or middle-income countries.

AIM

To implement tailored interventions to reduce CLABSI rates in adult intensive care units.

METHODS

The implementation strategy of the State Health Department was performed in São Paulo State, Brazil, over two cycles. Cycle 1 (56 hospitals) was exploratory and cycle 2 (77 hospitals) was designed to confirm the hypothesis generated by the first cycle, with three phases each (pre-intervention, intervention, post-intervention). Cycles included: evaluation of healthcare workers' knowledge, observation of practices, and CLABSI rates monthly report. In cycle 1, a log-normal mixed model was used to select variables significantly associated with the reduction of CLABSI. In cycle 2, CLABSI rates were evaluated.

FINDINGS

Healthcare workers' practices improved after intervention. In cycle 1, reduction of CLABSI rates was more pronounced in hospitals with initial CLABSI rates >7.4 per 1000 catheter-days (P < 0.001) and those that introduced the use of peripherally inserted central catheters (P = 0.01). For hospitals with high CLABSI initial rates, simulation demonstrated that the rates were expected to decrease by 36% (95% CI: 9-63), no matter the type of intervention. In cycle 2, there was an overall decrease in CLABSI rates during the intervention period; whereas the mean rate fell further post-intervention, rates at the 90^th percentile increased.

CONCLUSION

The implementation strategy may have had an effect on infection rates independently of the specific interventions implemented; however, the sustainability of reduction in the post-intervention period remains a challenge.

A novel dihydrocoumarin under experimental and theoretical characterization

Coumarins are natural and synthetic active ingredients widely applied in diverse types of medicinal treatments, such as cancer, inflammation, infection, and enzyme inhibition (monoamine oxidase B). Dihydrocoumarin compounds are of great interest in organic chemistry due to their structural versatilities and, as part of our investigations concerning the structural characterization of small molecules, this work focuses on crystal structure and spectroscopic characterization of the synthesized and crystallized compound 4-(4-methoxyphenyl)-3,4-dihydro-chromen-2-one (C₁₆H₁₄O₃). Additionally, a theoretical calculation was performed using density functional theory to analyze the sites where nucleophilic or electrophilic attack took place and to examine the molecular electrostatic potential surface. Throughout all of these calculations, both density functional theory and Car-Parrinello molecular dynamics were performed by fully optimized geometry. The spectroscopic analysis indicated the presence of aromatic carbons and hydrogen atoms, and also the carbonyl and methoxy groups that were confirmed by the crystallographic structure. The C₁₆H₁₄O₃ compound has a non-classical intermolecular interaction of type C-H⋅⋅⋅O that drives the molecular arrangement and the crystal packing. Moreover, the main absorbent groups were characterized throughout calculated harmonic vibrational frequencies. Also, natural bond orbital analysis successfully locates the molecular orbital with π-bonding symmetry and the molecular orbital with π* antibonding symmetry. Finally, the gap between highest occupied and lowest unoccupied molecular orbitals implies in a high kinetic stability and low chemical reactivity of title molecule.

Clinical Outcome and Antimicrobial Therapeutic Drug Monitoring for the Treatment of Infections in Acute Burn Patients

PURPOSE

In critical burn patients, the pharmacokinetic parameters (absorption, distribution, metabolism, and excretion) of many classes of drugs, including antibiotics, are altered. The aim of this study was to compare 2 groups of burn patients undergoing treatment for health care-associated infections with and without therapeutic drug monitoring.

METHODS

A retrospective analysis of a clinical intervention (ie, a before/after study) was conducted with patients with health care-associated pneumonia, burn infection, bloodstream infection, and urinary tract infection in the burn intensive care unit of a tertiary care hospital. The patients were divided into 2 groups: (1) those admitted from May 2005 to October 2008 who received conventional antimicrobial dose regimens; and (2) those admitted from November 2008 to June 2011 who received antibiotics (imipenem, meropenem, piperacillin, and vancomycin) with doses adjusted according to plasma monitoring and pharmacokinetic modeling. General characteristics of the groups were analyzed, as were clinical outcomes and 14-day and in-hospital mortality.

FINDINGS

Sixty-three patients formed the conventional treatment group, and 77 comprised the monitored treatment group. The groups were homogeneous, median age was 31 years (range: 1-90) and 66% were male. Improvement occurred in 60% of the patients under monitored treatment (vs 52% with conventional treatment); 14-day mortality was 16% vs 14%; and the in-hospital mortality was similar between groups (39% vs 36%). In the final multivariate models, variables significantly associated with in-hospital mortality were total burn surface area ≥30%, older age, and male sex. Treatment group did not affect the prognosis.

IMPLICATIONS

Therapeutic drug monitoring of antimicrobial treatment did not alter the prognosis of these burn patients. More trials are needed to support the use of therapeutic drug monitoring to optimize treatment in burn patients.

Online continuing interprofessional education on hospital-acquired infections for Latin America

Introduction

Latin America is a large and diverse region, comprising more than 600 million inhabitants and one million physicians in over 20 countries. Resistance to antibacterial drugs is particularly important in the region. This paper describes the design, implementation and results of an international bi-lingual (Spanish and Portuguese) online continuing interprofessional interactive educational program on hospital-acquired infections and antimicrobial resistance for Latin America, supported by the American Society for Microbiology.

Methods

Participation, satisfaction and knowledge gain (through pre and post tests) were used. Moreover, commitment to change statements were requested from participants at the end of the course and three months later.

Results

There were 1169 participants from 19 Latin American countries who registered: 57% were physicians and 43% were other health care professionals. Of those, 1126 participated in the course, 46% received a certificate of completion and 54% a certificate of participation. There was a significant increase in knowledge between before and after the course. Of 535 participants who took both tests, the grade increased from 59 to 81%. Commitments to change were aligned with course objectives.

Discussion

Implementation of this educational program showed the feasibility of a continent-wide interprofessional massive course on hospital acquired-infections in Latin America, in the two main languages spoken in the region. Next steps included a new edition of this course and a “New Challenges” course on hospital-acquired infections, which were successfully implemented in the second semester of 2015 by the same institutions.

Acinetobacter spp. are associated with a higher mortality in intensive care patients with bacteremia: a survival analysis

Background

It has been challenging to determine the true clinical impact of Acinetobacter spp., due to the predilection of this pathogen to colonize and infect critically ill patients, who often have a poor prognosis. The aim of this study was to assess whether Acinetobacter spp. bacteremia is associated with lower survival compared with bacteremia caused by other pathogens in critically ill patients.

Methods

This study was performed at Hospital das Clínicas, University of São Paulo, Brazil. There are 12 intensive care units (ICUs) in the hospital: five Internal Medicine ICUs (emergency, nephrology, infectious diseases and respiratory critical care), three surgical ICU (for general surgery and liver transplantion), an Emergency Department ICU for trauma patients, an ICU for burned patients, a neurosurgical ICU and a post-operative ICU. A retrospective review of medical records was conducted for all patients admitted to any of the ICUs, who developed bacteremia from January 2010 through December 2011. Patients with Acinetobacter spp. were compared with those with other pathogens (Klebsiella pneumoniae, Staphylococcus aureus, Enterobacter spp., Enterococcus spp., Pseudomonas aeruginosa). We did a 30-day survival analysis. The Kaplan-Meier method and log-rank test were used to determine the overall survival. Potential prognostic factors were identified by bivariate and multivariate Cox regression analysis.

Results

One hundred forty-one patients were evaluated. No differences between patients with Acinetobacter spp. and other pathogens were observed with regard to age, sex, APACHE II score, Charlson Comorbidity Score and type of infection. Initial inappropriate antimicrobial treatment was more frequent in Acinetobacter bacteremia (88 % vs 51 %). Bivariate analysis showed that age > 60 years, diabetes mellitus, and Acinetobacter spp. infection were significantly associated with a poor prognosis. Multivariate model showed that Acinetobacter spp. infection (HR = 1.93, 95 % CI: 1.25–2.97) and age > 60 years were independent prognostic factors.

Conclusion

Acinetobacter is associated with lower survival compared with other pathogens in critically ill patients with bacteremia, and is not merely a marker of disease severity.

Digestibility of energy, amino acids, and phosphorus in a novel source of soy protein concentrate and in soybean meal fed to growing pigs

Three experiments were conducted to determine standardized ileal digestibility (SID) of CP and AA, DE and ME, and apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of P in a new source of soy protein concentrate (SPC) and in soybean meal (SBM). In Exp. 1, 9 barrows (initial BW: 13.08 ± 1.98 kg) were prepared with a T-cannula in the distal ileum and allotted to a triplicated 3 × 3 Latin square design with 3 diets and 3 periods. A nitrogen-free diet and 2 diets that contained corn starch and SPC or SBM as the sole source of CP and AA were formulated. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. The SID for Ile, Leu, Phe, Pro, and Tyr was greater ( < 0.05) in SPC than in SBM, but for CP and all other AA, no difference between SPC and SBM was observed. In Exp. 2, 24 barrows (initial BW: 13.94 ± 1.34 kg) were housed individually in metabolism crates and randomly allotted to 1 of 3 diets. A corn-based diet (96.9% corn) and 2 diets that contained corn and SPC or corn and SBM were formulated. Each diet was fed to 8 pigs. Feces and urine samples were collected using the marker to marker method with 5-d adaptation and 5-d collection periods. The DE and ME in SPC and SBM were calculated using the difference procedure. Results indicated that the ATTD of GE was lower ( < 0.05) in SBM than in corn and the DE and ME in SPC were greater ( < 0.01) than in corn and SBM. In Exp. 3, 40 barrows (initial BW: 14.12 ± 2.08 kg) were placed in metabolism crates and allotted to 4 diets in a randomized complete block design with 10 pigs per diet. Two diets were based on SPC or SBM as the sole source of P. Two additional diets were formulated by adding microbial phytase to diets that were otherwise similar to the 2 initial diets. Feces were collected for 5 d after a 5-d adaptation period and values for ATTD and STTD of P were calculated. No differences were observed in ATTD and STTD of P between SPC and SBM, but the ATTD and STTD of P of both SPC and SBM were greater ( < 0.01) if microbial phytase was added to the diets. In conclusion, the concentrations of DE and ME are greater in SPC than in SBM, but the SID of most AA and the STTD of P are not different between SPC and SBM.

MRI Texture Analysis Reveals Bulbar Abnormalities in Friedreich Ataxia

BACKGROUND AND PURPOSE

Texture analysis is an image processing technique that can be used to extract parameters able to describe meaningful features of an image or ROI. Texture analysis based on the gray level co-occurrence matrix gives a second-order statistical description of the image or ROI. In this work, the co-occurrence matrix texture approach was used to extract information from brain MR images of patients with Friedreich ataxia and a control group, to see whether texture parameters were different between these groups. A longitudinal analysis was also performed.

MATERIALS AND METHODS

Twenty patients and 21 healthy controls participated in the study. Both groups had 2 sets of T1-weighted MR images obtained 1 year apart for every subject. ROIs chosen for analysis were the medulla oblongata and pons. Texture parameters were obtained for these ROIs for every subject, for the 2 sets of images. These parameters were compared longitudinally within groups and transversally between groups.

RESULTS

The comparison between patients and the control group showed a significant differences for the medulla oblongata (t test, P < .05, Bonferroni-corrected) but did not show a statistically significant difference for the pons. Longitudinal comparison of images obtained 1 year apart did not show differences for either patients or for controls, in any of the analyzed structures.

CONCLUSIONS

Gray level co-occurrence matrix-based texture analysis showed statistically significant differences for the medulla oblongata of patients with Friedreich ataxia compared with controls. These results highlight the medulla as an important site of damage in Friedreich ataxia.

Risk factor for death in hematopoietic stem cell transplantation: are biomarkers useful to foresee the prognosis in this population of patients?

BACKGROUND

The morbidity and mortality in hematopoietic stem cell transplantation (HSCT) occur due to infectious complications and constitute the major clinical problems in HSCT recipients. The role of the use of biomarkers in post-HSCT patients is still controversial.

OBJECTIVES

To assess the serum values of biomarkers interleukin 6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) and risk factors for post-HSCT death.

PATIENTS AND METHODS

Prospective study conducted in patients submitted to HSCT at a university hospital. Biomarkers (IL-6, PCT and CRP) were assessed on the day afebrile neutropenia was detected, in the febrile event, 24 and 72 h after fever onset and 48 h or 5 days if fever persisted. Patients were compared as to the death outcome within 30 days from the HSCT. Variables with p < 0.15 were included in the multivariate analysis model (MVA) that were performed for all patients included in the study and separated for autologous and allogeneic HSCT patients.

RESULTS

296 patients with ages ranging between 15 and 70 years, neutropenic, submitted to HSCT, being 216 (73%) autologous and 80 (20%) allogeneic were assessed. One hundred and ninety (64.2%) patients presented fever after the transplantation and infection microbiologically controlled in 78 (26.4%). Twenty-three cases (7.8%) evolved to death. The risk factors associated with death in the bivariate analysis were age, allogeneic transplantation, unrelated transplantation, GVHD, bloodstream infection by Gram-negative, IL-6 >140 pg/mL and CRP ≥ 120 mg/L and the protective ones were lymphoma and hospital outpatient support. The independent variables in the MVA associated with death were allogeneic and unrelated transplantation, blood stream infection (BSI) by Gram-negative, LDH ≥ 390 UI/L, urea ≥ 25 mg/dL and CRP ≥ 120 mg/L for HSCT transplanted patients and BSI due to Gram-negative and CRP ≥ 120 mg/L for allogeneic HSCT, however, CRP ≥ 120 mg/L did not remain in the model when urea ≥ 25 mg/L was included. No independent risk factor was found for autologous patients.

CONCLUSIONS

Out of the biomarkers assessed, only CRP ≥ 120 mg/L was independently associated with death. Other risk factors found were: type of transplantation (allogeneic and unrelated), bloodstream infection by Gram-negative, LDH ≥ 390 UI/L and urea ≥ 25 mg/dL. For allogeneic patients only CRP ≥ 120 mg/L and BSI due to Gram-negative were risk factors for death; however, CRP did not remain in the model when urea ≥ 25 mg/L was included.

Polyclonal outbreak of bloodstream infections caused by Burkholderia cepacia complex in hematology and bone marrow transplant outpatient units

Aim: The objective was to describe an outbreak of bloodstream infections by Burkholderia cepacia complex (Bcc) in bone marrow transplant and hematology outpatients.

Methods: On February 15, 2008 a Bcc outbreak was suspected. 24 cases were identified. Demographic and clinical data were evaluated. Environment and healthcare workers' (HCW) hands were cultured. Species were determined and typed. Reinforcement of hand hygiene, central venous catheter (CVC) care, infusion therapy, and maintenance of laminar flow cabinet were undertaken. 16 different HCWs had cared for the CVCs. Multi-dose heparin and saline were prepared on counter common to both units.

Findings: 14 patients had B. multivorans (one patient had also B. cenopacia), six non-multivorans Bcc and one did not belong to Bcc. Clone A B. multivorans occurred in 12 patients (from Hematology); in 10 their CVC had been used on February 11/12. Environmental and HCW cultures were negative. All patients were treated with meropenem, and ceftazidime lock-therapy. Eight patients (30%) were hospitalized. No deaths occurred. After control measures (multidose vial for single patient; CVC lock with ceftazidime; cleaning of laminar flow cabinet; hand hygiene improvement; use of cabinet to store prepared medication), no new cases occurred.

Conclusions: This polyclonal outbreak may be explained by a common source containing multiple species of Bcc, maybe the laminar flow cabinet common to both units. There may have been contamination by B. multivorans (clone A) of multi-dose vials.

Pandemic 2009 H1N1 influenza among health care workers

To evaluate factors associated with pandemic influenza among health care workers (HCWs), a case-case-control study was conducted with 52 confirmed cases, 120 influenza-negative cases, and 102 controls. Comorbidities (odds ratio [OR], 19.05; 95% confidence interval [95% CI]: 4.75-76.41), male sex (OR, 5.11; 95% CI: 1.80-14.46), and being a physician (OR, 8.58; 95% CI: 2.52-29.27) were independent risk factors for pandemic influenza infection among HCWs. Contact with symptomatic coworker or social contact was protective (OR, 0.11; 95% CI: 0.04-0.29). To our knowledge, this is the first study of factors associated with acquiring influenza involving HCW in nonsevere cases.

Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24-hour Holter electrocardiography

Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN(50) (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (P<0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN(50), SDANN, and LA/AO (left atrial to aortic root ratio) (r=0.92; P<0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN(50) are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.

Reduction of aflatoxin B1 in stored peanuts (Arachis hypogaea L.) using Saccharomyces cerevisiae

Aflatoxin B(1) is a toxigenic and carcinogenic compound produced by Aspergillus flavus and Aspergillus parasiticus. To inhibit aflatoxin contamination of peanuts, seeds of two peanut breeds, IAC Caiapó and IAC Runner 886, were inoculated with A. parasiticus (1.0 × 10(6) spores per ml) and the yeast Saccharomyces cerevisiae (3.2 × 10(7) cells per ml) and incubated at 25°C for 7 and 15 days. Two experiments were conducted for each incubation period separately. The treatments were completely randomized, with three replications per treatment. Treatments included the two cultivars and three types of inoculation (pathogen alone, yeast and pathogen, and yeast 3 h before pathogen). Aflatoxin B(1) was quantified with a densitometer at 366 nm after thin layer chromatography. Aflatoxin B(1) contamination in peanuts was reduced after the addition of S. cerevisiae. The concentration of aflatoxin B(1) decreased by 74.4 and 55.9% after 7 and 15 days, respectively. The greatest aflatoxin reduction was observed when S. cerevisiae was inoculated 3 h before the pathogen in IAC Caiapó seeds and incubated for 7 days at 25°C. The use of S. cerevisiae is a promising strategy for biological control of aflatoxin contamination in peanuts.

Morphological and electrophysiological properties of pyramidal-like neurons in the stratum oriens of Cornu ammonis 1 and Cornu ammonis 2 area of Proechimys

Proechimys (Rodentia: Echimyidae) is a neotropical rodent of the Amazon region that has been successfully colonized in the laboratory and used for experimental medicine. Preliminary studies indicated that Proechimys (casiragua) rodents express an atypical resistance to developing a chronic epileptic condition in common models of temporal lobe epilepsy. Moreover, previous investigation of our laboratory described a remarkably different Proechimy's cytoarchitecture organization of the hippocampal CA2 subfield. In the present study, we investigated the intrinsic neuronal properties and morphological characteristics of the Proechimys's hippocampal pyramidal neurons of the CA1 and CA2 areas. A comparative approach was performed using neurons recorded in Wistar rats. A striking finding in Proechimys rodents was the presence of large pyramidal-like neurons throughout the stratum oriens from CA2 to CA1 area. In order to confirm such distinctive feature of the Proechimys's hippocampus, we performed Nissl staining and immunohistochemistry for neurofilament protein SM311. CA2 pyramidal neurons in the stratum pyramidale of Proechimys exhibited a significantly higher input resistance and lower time constant when compared to corresponding cell groups in the same area of the Wistar rat's. This newly identified population of pyramidal-shaped neurons in stratum oriens of Proechimys exhibited distinct electrophysiological and morphological properties. This included larger capacitance, lower input resistance, larger rheobase, long latency to first action potential and slower firing frequency. In addition, the apical dendrites of these neurons were oriented in parallel to apical dendrites of regular pyramidal neurons in stratum pyramidale. Moreover, these neurons were immunoreactive to SM311 as the majority of the neurons of the pyramidal layer. The functional role of these hippocampal neurons of the rodent Proechimys deserves further investigation.

Methicillin-resistant Staphylococcus aureus (MRSA) carriage in a dermatology unit

OBJECTIVE

The aim of this study was to characterize Staphylococcus aureus (MRSA) carriage in a dermatology unit.

METHODS

This was a prospective and descriptive study. Over the course of 26 weeks, surveillance cultures were collected weekly from the anterior nares and skin of all patients hospitalized in a 20-bed dermatology unit of a tertiary-care hospital. Samples from healthcare workers (HCWS) were cultured at the beginning and end of the study. Colonized patients were put under contact precautions, and basic infection control measures were enforced. Staphylococcus aureus colonization pressure was determined monthly. Colonized and non-colonized patients were compared, and isolates were evaluated for antimicrobial susceptibility, SCCmec type, virulence factors, and type.

RESULTS

Of the 142 patients evaluated, 64 (45%) were colonized by MRSA (39% hospital acquired; 25% community acquired; 36% indeterminate). Despite isolation precautions, hospital-acquired Staphylococcus aureus occurred in addition to the continuous entry of Staphylococcus aureus from the community. Colonization pressure increased from 13% to 59%, and pemphigus and other bullous diseases were associated with MRSA colonization. Eleven out of 71 HCWs (15%) were Staphylococcus aureus carriers, although only one worker carried a persistent clone. Of the hospital-acquired MRSA cases, 14/28 (50%) were SCCmec type IV (3 PFGE types), 13 were SCCmec type III (46%), and one had an indeterminate type. These types were also present among the community-acquired Staphylococcus aureus isolates. SSCmec type IV isolates were shown to be more susceptible than type III isolates. There were two cases of bloodstream infection, and the pvl and tst virulence genes were absent from all isolates.

CONCLUSIONS

Dermatology patients were colonized by community- and hospital-acquired Staphylococcus aureus. Half of the nosocomial Staphylococcus aureus isolates were SCCmec type IV. Despite the identification of colonized patients and the subsequent contact precautions and room placement, Staphylococcus aureus colonization continued to occur, and colonization pressure increased. Pemphigus and other bullous diseases were associated with Staphylococcus aureus.

Evaluation of interventions to reduce catheter-associated bloodstream infection: continuous tailored education versus one basic lecture

BACKGROUND

This study evaluated the impact of 2 models of educational intervention on rates of central venous catheter-associated bloodstream infections (CVC-BSIs).

METHODS

This was a prospective observational study conducted between January 2005 and June 2007 in 2 medical intensive care units (designated ICU A and ICU B) in a large teaching hospital. The study was divided into in 3 periods: baseline (only rates were evaluated), preintervention (questionnaire to evaluate knowledge of health care workers [HCWs] and observation of CVC care in both ICUs), and intervention (in ICU A, tailored, continuous intervention; in ICU B, a single lecture). The preintervention and intervention periods for each ICU were compared.

RESULTS

During the preintervention period, 940 CVC-days were evaluated in ICU A and 843 CVC-days were evaluated in ICU B. During the intervention period, 2175 CVC-days were evaluated in ICU A and 1694 CVC-days were evaluated in ICU B. Questions regarding CVC insertion, disinfection during catheter manipulation, and use of an alcohol-based product during dressing application were answered correctly by 70%-100% HCWs. Nevertheless, HCWs' adherence to these practices in the preintervention period was low for CVC handling and dressing, hand hygiene (6%-35%), and catheter hub disinfection (45%-68%). During the intervention period, HCWs' adherence to hand hygiene was 48%-98%, and adherence to hub disinfection was 82%-97%. CVC-BSI rates declined in both units. In ICU A, this decrease was progressive and sustained, from 12 CVC-BSIs/1000 CVC-days at baseline to 0 after 9 months. In ICU B, the rate initially dropped from 16.2 to 0 CVC-BSIs/1000 CVC-days, but then increased to 13.7 CVC-BSIs/1000 CVC-days.

CONCLUSION

Personal customized, continuous intervention seems to develop a "culture of prevention" and is more effective than single intervention, leading to a sustained reduction of infection rates.

Polymyxin B and colistimethate are comparable as to efficacy and renal toxicity

We compared 41 patients who received colistimethate with 41 who received polymyxin B for the treatment of serious infections caused by carbapenem-resistant Acinetobacter spp. and found both polymyxins have similar efficacy and toxicity.

Bovine herpesvirus 5 induces an overproduction of nitric oxide in the brain of rabbits that correlates with virus dissemination and precedes the development of neurological signs

We herein report an investigation of nitric oxide (NO) levels, a candidate molecule for neuronal toxicity and dysfunction, in the brain of rabbits during experimental neurological infection by bovine herpesvirus 5 (BoHV-5). Spectrophotometry for NO products (NO(2) and NO(3)) revealed that NO levels were significantly increased (F(4, 40) = 3.33; P <.02) in several regions of the brain of rabbits with neurological disease, correlating with moderate to high BoHV-5 titers. Immunohistochemistry of brain regions revealed a group of cells with neuronal and astrocyte morphology expressing the enzyme inducible NO synthase (iNOS) close to virus antigen-positive neurons. In addition, the investigation of nitric oxide levels between 2 and 6 days post infection (d.p.i.) revealed an initial increase in NO levels in the olfactory bulb and cortex (OB/OC) and anterior cortex (AC) at day 3 p.i., correlating with the initial detection of virus. As the infection proceeded, increased NO levels-and infectivity-were progressively being detected in the OB/CO and AC at day 4 p.i. (F(12, 128) = 2.82; P <.003); at day 5 p.i. in several brain regions (P <.003 in the OB/OC); and at day 6 p.i. in all regions (P <.003) but the thalamus. These results show that BoHV-5 replication in the brain of rabbits induces an overproduction of NO. The increase in NO levels in early infection correlated spatially and temporally with virus dissemination within the brain and preceded the development of neurological signs. Thus, the overproduction of NO in the brain of BoHV-5-infected rabbits may be a component of the pathogenesis of BoHV-5-induced neurological disease.

Disconnecting central hot water and using electric showers to avoid colonization of the water system by Legionella pneumophila: an 11-year study

Legionella spp. can be difficult to control in hospitals. The objective of this study was to describe an 11-year experience with the use of electric showers in the control of Legionella pneumophila. From June 1989 to March 1990 there was an outbreak of pneumonia caused by L. pneumophila in a 20-bed renal transplant unit in a university-associated tertiary-care hospital. Control measures included hyperchlorination, heating and flushing of the water system with limited results. In November 1993 the central hot water was disconnected and water for bathing was heated using electric showers. From January 1992 to June 1995 water was collected from showers and water faucets and cultured for L. pneumophila every two weeks. Surveillance cultures were then collected every month until May 1999. During this seven-year surveillance period, 1115 samples of water were cultured. Water cultures were positive on 24 of 429 occasions (without cases of legionellosis) during the pre-shower period (22 months). In the post-shower period (67 months) only one of 686 cultures was positive. Subsequently there have been no new cases of nosocomial pneumonia by L. pneumophila although surveillance continues. In conclusion, disconnecting the central hot water was effective in avoiding colonization of the water system by L. pneumophila. Heating was possible by using electric showers, which are effective, easy to maintain and cheap.

Investigation of the possible association between nosocomial candiduria and candidaemia

This study aimed to determine whether candiduria is associated with the occurrence of nosocomial candidaemia. In the case-control part of the study, 115 cases (nosocomial candidaemia) and 115 controls (nosocomial bacteraemia) were similar in age, severity of condition and time of hospitalisation. There was a significant association of candidaemia with candiduria (OR 9.79; 95% CI 2.14-44.76). In the microbiology part of the study, 23 pairs of Candida-positive urine and blood cultures were obtained from 23 patients. In ten (43%) cases, the urine and blood culture isolates belonged to different species, and molecular typing showed a difference in two of the 13 cases yielding the same species from both specimens. Overall, there was a significant association between candiduria and candidaemia, but the Candida isolates from urine and blood were different for 52% of the patients. Thus, the data indicated that the urinary tract was probably not a source for the candidaemia.

Hepatitis C virus infection among Brazilian hemophiliacs: a virological, clinical and epidemiological study

We determined and analyzed risk factors of hepatitis C virus (HCV)-infected Brazilian hemophiliacs according to their virological, clinical and epidemiological characteristics. A cross-sectional and retrospective study of 469 hemophiliacs was carried out at a Brazilian blood center starting in October 1997. The prevalence of HCV infection, HCV genotypes and factors associated with HCV RNA detection was determined. The seroprevalence of anti-HCV antibodies (ELISA-3.0) was 44.6% (209/469). Virological, clinical and epidemiological assessments were completed for 162 positive patients. There were seven (4.3%) anti-HCV seroconversions between October 1992 and October 1997. During the same period, 40.8% of the positive anti-HCV hemophiliacs had abnormal alanine transaminase (ALT) levels. Plasma HCV RNA was detected by nested-RT-PCR in 116 patients (71.6%). RFLP analysis showed the following genotype distribution: HCV-1 in 98 hemophiliacs (84.5%), HCV-3 in ten (8.6%), HCV-4 in three (2.6%), HCV-2 in one (0.9%), and not typeable in four cases (3.4%). Univariate analysis indicated that older age (P = 0.017) and abnormal ALT levels (P = 0.010) were associated with HCV viremia, while the presence of inhibitor antibodies (P = 0.024) and HBsAg (P = 0.007) represented a protective factor against the presence of HCV RNA. These findings may contribute to a better understanding of the relationship between HCV infection and hemophilia.

Detection of mycobacteria in the bloodstream of patients with acquired immunodeficiency syndrome in a university hospital in Brazil

This study was done to determine the occurrence of mycobacteria in the bloodstreams of patients with fever and advanced AIDS in a Brazilian hospital. We also verified the capability of an automated method for recovering these bacteria. During a period of 19 months, 254 patients with AIDS were evaluated. Blood cultures were generally submitted in pairs and drawn separately. Blood cultures were processed by the BACTEC 460TB System (Becton Dickinson Microbiology Systems, Sparks, MD), using the Bactec 13A media (Becton Dickinson Microbiology Systems, Sparks, MD). Of the 530 vials submitted, 77 (14.5%) from 41 (16%) patients were positive. Mycobacterium avium complex was recovered from 45 (58.4%) of the 77 positive vials, corresponding to 22 (53.6%) patients with positive blood cultures. The average time to detect Mycobacterium avium complex was 15 days. Mycobacterium tuberculosis was recovered from 26 (33.8%) of the 77 positive vials, corresponding to 15 (36.6%) patients with positive blood cultures, with an average detection time of 24 days. Other species of mycobacteria were recovered from 6 (7.8%) of the 77 vials, corresponding to 4 (9.8%) patients. M.avium complex was fairly prevalent (8.7%) in severely ill patients with AIDS in our hospital. M. tuberculosis was also an important (6.0%) agent of systemic bacterial infections in these patients. The rapid diagnosis of mycobacteremia was possible with the implementation of this automated technology.

Syphilitic meningitis in HIV-patients with meningeal syndrome: report of two cases and review

Few patients with symptomatic neurosyphilis present with signs and symptoms of acute meningitis. Here we report two cases of syphilitic meningitis diagnosed in HIV patients with meningeal syndrome. The first case, a 30-year-old black bisexual male, had concurrent meningeal and ocular syphilis with persistent unusually low CSF glucose levels. He responded well to 21 days of intravenous penicillin therapy. The second case was a 55-year-old female with epilepsy, depression, behavioral disorder and confusion. The diagnosis of HIV infection was made after onset of the syphilitic meningitis. She was treated with 21 days i.v. penicillin with improvement in her clinical condition. The clinical aspects of combined neurosyphilis and HIV infection, plus special features of diagnosis and treatment are discussed.

Anti-TNP monoclonal antibodies as reagents for enzyme immunoassay (ELISA)

The aim of this study was to produce anti-TNP monoclonal antibodies (MAbs) that could be conjugated and used for the detection of antigen-antibody reactions, in which the antigen specific-antibody had been previously bound to trinitrophenyl (TNP). For hybridoma production, SP2/0-Ag14 cells were fused with spleen cells from mice previously immunized with TNP-ovalbumin (TNP-OVA). After 10 days, enzyme-linked immunoadsorbent assay (ELISA) was used to detect anti-TNP antibodies in the supernatants, and five cultures were found to be strictly positive for TNP. Three of these were subsequently cloned by limiting dilution, and 15 clones were chosen for expansion based on the criterion of high reactivity against TNP. Anti-TNP MAbs produced by those clones were isotyped as IgG1, and purified by Sepharose-protein G affinity cromatography from ascites developed in BALB/c mice. Two purified MAbs (1B2.1B6 and 1B2.1E12) were coupled to horseradish peroxidase (HRPO). The resulting conjugates were evaluated in ELISA tests for interferon-gamma and interleukin-4 detection, in which the secondary anti-cytokine antibodies were coupled either to TNP or biotin. The performance of anti-TNP conjugates in these assays were compared with a biotin-streptavidin/peroxidase system. Both types of conjugates were similarly able to detect cytokines with r2 (linear correlation coefficient) close to unity value. Growth studies of one of those hybridomas (1B2.1B6) yielded a specific growth rate of 0.042 h(-1) and a doubling time of 16.5 h. Data discussed here show that at least two MAbs against TNP raised in this work can be used as a reagent for enzyme immunoassays.

Propionic acid metabolism and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P3HB-co-3HV) production by Burkholderia sp

Mutants of Burkholderia sp. that are unable to grow on propionic acid (prp) but still accumulate P3HB-co-3HV from carbohydrate and propionic acid were studied. In shaken flask tests, yields of 3HV from propionic acid (Y(3HV/Prop)) increased from 0.10 g g(-1) in the wild type to c.a. 0.35 g g(-1) in mutants affected in alpha-oxidation pathway or to 0.80 g g(-1) in mutants not affected in that pathway. In bioreactor tests, mutant IPT 189 showed Y(3HV/Prop) = 1.20 g g(-1), a yield very close to the theoretical maximum of 1.35 g g(-1). Accumulation of 3HV units from unrelated carbon sources was undetectable in these mutants indicating that 3HV units are produced directly from propionic acid. Thus, the industrial use of those mutants to produce the copolymer from sucrose and propionic acid could significantly reduce the production costs. The results strongly suggest the existence of at least two pathways that are involved in the oxidation of propionic acid in Burkholderia sp. Their rates would be modulated by the availability of propionic acid.

Protection against thermal denaturation by trehalose on the plasma membrane H+-ATPase from yeast. Synergetic effect between trehalose and phospholipid environment

Yeast cells have had to develop mechanisms in order to protect themselves from chemical and physical agents of the environment to which they are exposed. One of these physical agents is thermal variation. Some yeast cells are known to accumulate high concentrations of trehalose when submitted to heat shock. In this work, we have studied the effect of trehalose on the protection against thermal inactivation of purified plasma membrane H+-ATPase from Schizosaccharomyces pombe, in the solubilized and in the reconstituted state. We observed that after 1 min of incubation at 51 degrees C in the presence of 1 M trehalose, about 50% of soluble enzyme remains active. In the same conditions, but in the absence of trehalose, the activity was completely abolished. The t0.5 for the enzyme inactivation increased from 10 to 50 s after reconstitution into asolectin liposomes. Curiously, in the presence of 1 M trehalose, the t0.5 for inactivation of the reconstituted enzyme was further increased to higher than 300 s, regardless of whether trehalose was added inside or outside the liposome. Additionally, the concentration that confers 50% for the protection by trehalose (K0.5) decreased from 0.5 M, in the solubilized state, to 0.04 M in the reconstituted state, suggesting a synergetic effect between sugar and lipids. Gel electrophoresis revealed that the pattern of H+-ATPase cleavage by trypsin changed when 1 M trehalose was present in the buffer. It is suggested that both in a soluble and in a phospholipid environment, accumulation of trehalose leads to a more heat-stable conformation of the enzyme, probably an E2-like form.

Simultaneous high-performance liquid chromatographic determination of retinol by fluorometry and of tocopherol by ultraviolet absorbance in the serum of newborns

The simultaneous determination of retinol and tocopherol by isocratic HPLC in 100 microl serum from preterm newborns is described. Retinol (tR 2.02+/-0.04 min) and retinyl acetate were detected fluorometrically, and were baseline-resolved in 4 min. Tocopherol (tR 8.4+/-0.16 min) and tocopheryl acetate were detected by UV absorbance. Intra- and inter-assay RSD were: retinol, 5.6 and 8.1, and tocopherol, 3.6 and 6.7, respectively. This method is fast, selective and highly sensitive for retinol. It permits the measurement of serum concentrations of retinol and tocopherol with good accuracy and precision.

Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. Our laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, we have investigated more than one hundred cases where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. We have also used conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field.

Behavior and progesterone levels in Callithrix jacchus females

In callitrichids, and especially in the Callithrix and Saguinus genera, reproductive suppression maintains the breeding exclusivity of dominant females. It has been suggested that dominance may be inferred from agonistic behavior of females. The purpose of this study was to assess the adequacy of behaviors as indicators of hormonal status in Callithrix jacchus females. Two pairs of twin females were observed for affiliative, agonistic and sexual behaviors for 20 weeks, in four stages of increasingly potential competition for one male. During the same period, blood samples were taken regularly for progesterone determination by ELISA. The two pairs differed markedly as to behaviors and hormonal status: pair 1 showed a well established behavioral dominance and only one ovulating female from the beginning of the observation period; pair 2 showed competition for dominance until the last stage of observation, when one of the females started ovulating. Correlations between behaviors and progesterone levels showed differences between subordinate and dominant females mostly in pair 2. Although limited in number of animals studied, these results suggest that there is a relationship between behavior and hormones in female marmosets, but this relationship may be useful in the identification of the physiological status of females only in groups where the dominance is not well established.

Evaluation of different methods for Plasmodia detection, in well defined population groups in an endemic area of Brazil (1)

In Brazil, more than 500,000 new cases of malaria were notified in 1992. Plasmodium falciparum and P. vivax are the responsible species for 99.3% of the cases. For adequate treatment, precoce diagnosis is necessary. In this work, we present the results of the traditional Plasmodia detection method, thick blood film (TBF), and the results of alternative methods: Immunofluorescence assay (IFA) with polyclonal antibody and Quantitative Buffy Coat method (QBC) in a well defined population groups. The analysis were done in relation to the presence or absence of malaria clinical symptoms. Also different classes of immunoglobulins anti-P.falciparum were quantified for the global analysis of the results, mainly in the discrepant results. We concluded that alternative methods are more sensitive than TBF and that the association of epidemiological, clinical and laboratory findings is necessary to define the presence of malaria.

Acute megakaryoblastic leukemia in children and adolescents: a retrospective analysis of 24 cases

In order to characterize the clinical, cytogenetic, and outcome features of childhood acute megakaryoblastic leukemia (AMKL), we reviewed 24 cases; 14 were identified among 150 consecutive newly diagnosed acute myelogenous leukemia (AML) patients at St. Jude Children's Research Hospital, and 10 were cases referred to the National Institute of Cancer in Rio de Janeiro, Brazil. There were 5 Down syndrome patients and one patient with chronic myeloid leukemia (Ph+) in blastic crisis. Twelve patients had significant hepatosplenomegaly. Leukemic cell morphology and cytochemistry were consistent with the M7 classification in 17 cases, and all cases tested expressed megakaryocytic surface antigens. AMKL patients were significantly younger than other AML patients (P = 0.0001) and had poorer responses to therapy (P = 0.03, univariate analysis only). Ten of 24 failed induction, and only 5 are disease-free at 6 months to 4.5+ years. We conclude that AMKL usually affects young children, frequently producing marked organomegaly. It comprises approximately 10% of pediatric AML cases, and responds poorly to intensive AML therapies.

Detection of heat-labile (LT) enterotoxin of enterotoxigenic Escherichia coli by the radial immune hemolysis test: a modification for clinical use

An adaptation for clinical purposes of a radial immune hemolysis test for the detection of the heat-labile (LT) enterotoxin of the enterotoxigenic Escherichia coli is described. The results correlated well with those from Vero cell assay and the passive immune hemolysis test. Because the test is easy, relatively cheap, and as sensitive as other standard procedures, for LT detection, it is particularly suitable for less-equipped laboratories. Also, a large number of E. coli strains may be examined daily by this technique.

Evaluation of a defined medium for the production of both thermolabile (LT) and thermostable (ST) enterotoxins of Escherichia coli

The production of thermolabile (LT) enterotoxin was compared in a defined medium reported by Staples et al. (SAG medium) for the production of thermostable (ST) enterotoxin and the Casamino acids-Yeast extract (CAYE) medium. Aliquots were drawn frum cultures of an enterotoxigenic (LT+, ST+) E. coli in both media at different times, growth curves were plotted, and culture filtrates tested for toxin activity. Levels of LT and ST and in the SAG showed that it is as suitable as CAYE for the production of LT. The addition of either glucose (1%) or lincomycin (90 microgram/ml) to SAG medium increased LT levels, but no synergistic effort could be observed if both substances were added concomitantly. Cultures in SAG medium incubated stationarily for 72 h at 37 degrees C yielded more LT than shaking cultures incubated similarly.

Mannose-resistant haemagglutination and colonisation factors among Escherichia coli strains isolated from pigs

Ten heat-labile (LT) and 23 heat-stable (ST) enterotoxin-producing strains of enterotoxigenic Escherichia coli (ETEC) and 100 non-enterotoxigenic E coli (non-ETEC) strains isolated from pigs with diarrhoea were examined for the presence of colonisation factors by means of mannose-resistant haemagglutination and serological tests. Seven of 10 LT strains, one of 23 ST and 18 of 100 non-ETEC carried K88 antigen; and four ST and four non-ETEC strains possessed CFA/I antigen. All strains carrying K88, K99 and CFA/I antigens were positive in the mannose-resistant microhaemagglutination (MRMH) test but four ST and 14 non-ETEC isolates positive in the MRMH test did not possess K88, K99 or CFA/I antigens. A considerable number of non-ETEC strains were positive in the MRMH test but lacked K88 and K99 antigens, suggesting that other unknown haemagglutinating colonisation factors may exist in porcine E coli strains.

Racial differences in anthropometric traits in school children of Bahia, Brazil

Two thousand four hundred and forty-four Brazilian school children were classified as Light, Medium and Dark according to a subjective jedgment of the proportion of Negro admixture, and studied for weight, height, span and upper-segment/lower-segment (US/LS) ratio. The mean US/LS ratio decreases significantly as the proportion of Negro admixture increases giving an intermediate value for those children belonging to the Medium group for race.