Geraldo Picheth

Butyrylcholinesterase activity and risk factors for coronary artery disease.

The aim of this study was to verify which risk factors for coronary artery disease (CAD) are independently correlated with butyrylcholinesterase (BChE) activity. We studied 88 White individuals (43 males) aged 47.3 - 15.7 years (mean - SD; range: 14.0 - 80.0 years) including 38 with hyperlipidemia, 30 with hypertension and 5 with diabetes mellitus (DM). Simple correlation analysis showed that BChE activity was positively correlated with age, sex, body mass index, hypertension and DM, as well as with triglycerides (TGs), total cholesterol, lowdensity lipoprotein cholesterol and apolipoprotein B (Apo B). However, after a step-wise multiple regression analysis, the only risk factors for CAD that showed independent correlations with BChE activity were, in descending order of importance, Apo B, TGs and DM. Our findings seem to reinforce suggested associations of BChE activity with lipoprotein synthesis and with hypertension, as well as supporting previous data on the relation of BChE activity with disturbances found in diabetes mellitus.

CARD15 and IL23R Influences Crohn's Disease Susceptibility But Not Disease Phenotype in a Brazilian Population

Background: Although many genetic variants are identified in association with Crohns disease (CD), CARD15, IL23R, and ATG16L1 association with CD have been firmly confirmed in Caucasians of European ancestry. The prevalence of CD is rapidly rising in Brazil, where European ancestry is firmly admixed with natives and Africans, resulting in a heterogeneous population. We investigated the contribution of CARD15, IL23R, and ATG16L1 with CD risk in a heterogeneous Brazilian population. Methods: Genotyping for CARD15 (R702W, G908R, 3020insC), IL23R (rs1004819, rs7517847, rs11209026, rs10889677, rs1495965), and ATG16L1 (rs2241880) was performed in 187 children and adults with CD and 255 healthy ethnically matched controls. Clinical records were systematically reviewed and detailed phenotypic information was obtained. Results: At least 1 CARD15 risk allele was present in 30% of the CD patients compared with 10% of controls. Variants of CARD15 (3020insC and R702W) and IL23R (rs1004819, rs11209026, and rs1088967) were associated with CD. However, no genotype–phenotype correlations were found among the Brazilian CD population with CARD15 or IL23R variants. No significant association was achieved with ATG16L1. Conclusions: CARD15 and IL23R confer susceptibility to CD in the Brazilian population. However, the presence of these variants did not influence disease phenotype. Further research should be focused on larger sample sizes with population admixture analysis to better understand the risks and genotype–phenotype correlation in populations like Brazil where the prevalence of CD is rapidly rising.

Influence of a light meal on routine haematological tests.

INTRODUCTION Patient-related variables, such as physical exercise, stress and fasting status are important sources of variability in laboratory testing. However, no clear indications about fasting requirements exist for routine haematological tests, nor has the influence of meals been assessed. METHODS We studied 17 healthy volunteers who consumed a light meal containing a standardized amount of carbohydrates, protein and lipids. Blood was taken for routine haematological tests before the meal and 1, 2 and 4 hours thereafter. RESULTS One hour after the meal, neutrophil count and mean corpuscular haemoglobin (MHC) increased significantly, whereas lymphocyte and monocyte counts, red blood cell distribution width, haematocrit, and mean corpuscular volume decreased significantly. A clinically significant variation was only observed for lymphocytes. Two hours after the meal, a significant increase was observed for neutrophils and MCH, whereas lymphocytes, eosinophils, haemoglobin and haematocrit decreased significantly. Clinically significant variations were recorded for lymphocytes, red blood cells (RBC), haemoglobin, haematocrit and MCH. Four hours after the meal MCH was significantly increased, while lymphocytes, eosinophils, RBC, haemoglobin and haematocrit were significantly decreased. Clinically significant variations were recorded for neutrophils, eosinophils, RBC, hematocrit and MCH. CONCLUSION The significant variation of several haematological parameters after a light meal demonstrates that the fasting time needs to be carefully considered in order to interpret the results of haematological tests correctly.

Impact of the phlebotomy training based on CLSI/NCCLS H03-A6 - procedures for the collection of diagnostic blood specimens by venipuncture.

Introduction: The activities involving phlebotomy, a critical task for obtaining diagnostic blood samples, are poorly studied as regards the major sources of errors and the procedures related to laboratory quality control. The aim of this study was to verify the compliance with CLSI documents of clinical laboratories from South America and to assess whether teaching phlebotomists to follow the exact procedure for blood collection by venipuncture from CLSI/NCCLS H03-A6 - Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture might improve the quality of the process. Materials and methods: A survey was sent by mail to 3674 laboratories from South America to verify the use of CLSI documents. Thirty skilled phlebotomists were trained with the CLSI H03-A6 document to perform venipuncture procedures for a period of 20 consecutive working days. The overall performances of the phlebotomists were further compared before and after the training program. Results: 2622 from 2781 laboratories that did answer our survey used CLSI documents to standardize their procedures and process. The phlebotomists’ training for 20 days before our evaluation completely eliminated non-conformity procedures for: i) incorrect friction of the forearm, during the cleaning of the venipuncture site to ease vein location; ii) incorrect sequence of vacuum tubes collection; and iii) inadequate mixing of the blood in primary vacuum tubes containing anticoagulants or clot activators. Unfortunately the CLSI H03-A6 document does not caution against both unsuitable tourniquet application time (i.e., for more than one minute) and inappropriate request to clench the fist repeatedly. These inadequate procedures were observed for all phlebotomists. Conclusion: We showed that strict observance of the CLSI H03-A6 document can remarkably improve quality, although the various steps for collecting diagnostic blood specimens are not a gold standard, since they may still permit errors. Tourniquet application time and forearm clench should be verified by all quality laboratory managers in the services. Moreover, the procedure for collecting blood specimens should be revised to eliminate this source of laboratory variability and safeguard the quality.

Virulence characteristics and antimicrobial susceptibility of uropathogenic Escherichia coli strains

Eight virulence factors associated with uropathogenic Escherichia coli (UPEC) were investigated in 204 clinical isolates of E. coli recovered from urine cultures at counts ≥10(5). The bacteria were classified into two groups according to the number of leukocytes in urine samples from which they were isolated: group I ≤8 leukocytes/hpf, 104 strains; group II >8 leukocytes/hpf, 100 strains. Two multiplex PCR systems were used to detect genes encoding adhesin P (pap), adhesin S (sfa), afimbrial adhesin I (afa), siderophore aerobactin (aer), alpha-hemolysin (hly), cytotoxic necrotizing factor type 1 (cnf1), and traT associated with serum resistance. The PAI marker for the virulence island identified in strains CFT072 and CVD432, a marker of enteroaggregative E. coli, was also investigated using PCR. The susceptibility profile of E. coli strains was determined by disk diffusion method. Ninety percent UPEC showed at least one of the virulence genes, the prevalence being traT (76%), aer (41%), PAI (32%), sfa (26%), pap (25%), cnf1 (18%), afa (6%), and hly (5%). There was no significant difference in the distribution of virulence genes between groups I and II. A significantly higher degree of virulence was detected in UPEC group II. The CVD432 gene was not detected in any of the UPECs. Fifty-nine percent of the strains were resistant to at least one of the antimicrobials that we tested; the most common being resistance to ampicillin (51%) and trimethoprim-sulfamethoxazole (44%).

Suitability of a transport box for blood sample shipment over a long period

BACKGROUND Safety transport boxes are increasingly used to ship laboratory specimens but there is little information on their capacity to maintain suitable transportation temperatures. MATERIALS AND METHODS Inner temperature was assessed using a commercially available transport box during an 8-h transportation period in the heat. RESULTS Temperature stability was unsatisfactory during approximately 64% of the transportation time (i.e., from 125 to 450 min). CONCLUSIONS Transport boxes might be unsuitable for shipping specimens over long periods.

The C5 isozyme of serum cholinesterase and adult weight.

The relationship between the CHE2 locus of serum cholinesterase (BChE) and adult human weight was studied in a sample of 225 CHE2 C5+ individuals and 225 CHE2 C5- controls matched for sex, height, age and race. With respect to the intensity of the C5 band staining (scored 1-6), 113 individuals had faint C5 bands (scores 1-3) and 112 intense C5 bands (scores 4-6). The individuals with intense CHE2 C5+ phenotype showed a significantly lower mean adult weight (64.66 +/- 0.73 kg) when compared to their controls (70.59 +/- 0.97 kg) and a significant reduction in weight variance (59.81 and 105.18, respectively). Individuals with faint C5 bands, although showing a negative correlation between weight and C5 band intensity, did not differ from their controls in mean weight.

Transillumination: a new tool to eliminate the impact of venous stasis during the procedure for the collection of diagnostic blood specimens for routine haematological testing

Introduction:  The collection of diagnostic blood specimens for routine haematological testing (RHT) is traditionally performed with tourniquet. However, the transillumination devices based on cold near‐infrared LEDs have been formerly proposed as a valuable tool for identifying reliable venous accesses, especially in patients with difficult or small veins, such as children. This study was aimed to evaluate whether a transillumination device can advantageously replace the use of the tourniquet during the procedure for collection of blood specimens for RHT and thereby eliminating the discomfort and risk of spurious results caused by excessive or prolonged venous stasis.

Influence of a Regular, Standardized Meal on Clinical Chemistry Analytes

Background Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing. Methods We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter. Results One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels. Conclusions A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.

Elimination of the venous stasis error for routine coagulation testing by transillumination.

The preanalytical phase is responsible for more than two-thirds of all errors attributed to the clinical laboratory [1–4] and there are only a few routine procedures for the detection of nonconformities in this field of activity [5,6]. In this phase the procedures involving phlebotomy, critical to the obtainment of diagnostic blood specimens, are poorly studied as regards the major sources of errors and the procedures related to quality control process [7,8]. The collection of diagnostic blood specimens for routine coagulation tests are traditionally performed by phlebotomists using a tourniquet [9]. The Clinical and Laboratory Standards Institute (CLSI) recommends the use of the tourniquet for localizing suitable veins for ≤60 s. When performing specimen collection for diagnostic purposes such an interval of time both allows easy localization of vein paths and concomitantly circumvents possible problems due to excess venous stasis [10–12]. Although the venous stasis can influence the concentration and/or the activity of several blood analytes, the tourniquet time is rarely regarded as a potential source of laboratory variability [13–17]. Reportedly, the mean tourniquet application times by phlebotomists were 98 s in public laboratories and 70 s in private laboratories respectively, thus raising some issues about proper specimen collection [18]. The use of transillumination devices, based on cold near infrared light-emitting diodes (LEDs) whose lightsare absorbed by intra-erythrocyte hemoglobin flowing along the veins, has been initially proposed in order to ease the vein puncture in children [19]. The efficacy of palm transillumination for establishing venous access in small infants has already been assessed [20]. Moreover, the transillumination has been proposed for mapping veins to be cannulated prior to ambulatory phlebotomy because it allows accurate visualization of the vein course [21]. Reliability in coagulation testing is pivotal to the appropriate diagnosis and treatment of patients with hemostasis disturbances [17,22]. In this context some preanalytical details/procedures appear critical such as a) adequate fasting time before blood collection [23], b) use of appropriate tubes [24–26] and additives [27], c) appropriateness of blood collection, storage and centrifugation[28–30], and d) strict conformity to the recommendations regarding tourniquet time. Clinical laboratory results are estimated to be able to influence 60% to 70% of medical decisions and thus affect diagnostic outcome and/or patient treatments [31], such as oral anticoagulant therapy employed in patients at risk of thrombosis [32,33] or blood transfusion components prescription [34] recommended in bleeding patients with disseminated intravascular coagulation (DIC) and prolonged