[Accuracy and reliability between glucose meters: A study under normal clinical practice conditions]. / Exactitud y concordancia entre glucómetros: un estudio en condiciones habituales de práctica clínica.

INTRODUCTION: The glucose meters usually show a high accuracy, and in clinical practice, capillary and plasma glucose (PG) are used interchangeably. However, many variables can affect the validity of these devices. The aim of this study was to determine the accuracy and reliability of 3 glucose meters that are currently used in a primary care centre. MATERIAL AND METHODS: A sample of venous blood and a drop of capillary blood were obtained from 59 participants. The drop was analysed in 3 glucose meters: 2 FreeStyle® Optium (OP1 and OP2), and one Accu-Chek® Aviva. The PG acted as the reference value, and the haematocrit and plasma levels of urea, bilirubin, uric acid and triglycerides were also analysed. We used the Passing-Bablok regression for accuracy and the intraclass correlation coefficient and the Bland-Altman method for reliability. The current American Diabetes Association standard of a total error of±5% was applied. RESULTS: Differences in mean±standard deviation (mg/dL) and the systematic error were 5.8±7 and 5.8% (OP1); 6.2±8 and 5.9% (OP2); 8.3±8 and 6.3% (Accu-Chek®). The OP1/OP2 pair showed the highest level of reliability, with an intraclass correlation coefficient=0.97, bias=-0.4mg/dL, and a width of the 95% limits of agreement of 28.6mg/dL. The highest levels of accuracy and reliability were observed in high glucose ranges (PG≥126mg/dL). CONCLUSIONS: Despite their clinically acceptable mean difference compared to the PG, the 3 glucose meters did not fulfill the current American Diabetes Association standard. The regular performance of quality control tests of these devices is recommended.

Fiabilidad en la evaluación radiológica de la calcificación aórtica abdominal mediante la escala de 24 puntos / Reliability of radiologic evaluation of abdominal aortic calcification using the 24-point scale

Objetivo. La calcificación de la aorta abdominal se asocia a un incremento en el riesgo de morbilidad cardiovascular, y disponer de un método de cuantificación de la misma es clínicamente trascendente. La escala de 24 puntos (AAC-24) es el método estándar para su evaluación en la radiología simple lateral de columna lumbar. El objetivo del estudio ha sido conocer el nivel de acuerdo intra e interobservador que aporta esta escala, teniendo en cuenta la heterogeneidad de la distribución de las calcificaciones en el diseño del análisis estadístico. Material y métodos. Se analizó la concordancia intraobservador (sobre radiografías de 81 pacientes, con una separación de 4 años) y la concordancia interobservador (sobre radiografías de 100 pacientes, con tres evaluadores), utilizando simultáneamente la correlación intraclase y el método gráfico de Bland-Altman. Resultados. El coeficiente de correlación intraclase fue de 0,93 (intervalo de confianza al 95% [IC95%]: 0,6-0,9) y 0,91 (IC95%: 0,8-0,9), intra e interobservador, respectivamente, con un incremento del coeficiente en el tercil de mayor discrepancia. La diferencia de medias osciló entre 0,3 y-1,2 puntos. La amplitud entre los límites de acuerdo, entre 4,7 y 9,4 puntos. Se observó un aumento significativo de las diferencias en relación con el aumento progresivo de la calcificación. Conclusiones. La valoración de la calcificación de la aorta abdominal en radiología simple lateral de columna lumbar mediante la escala AAC-24 es un método fiable y reproducible, observándose un mayor grado de concordancia intra e interobservador en las fases iniciales de la calcificación (AU)

Objective. Calcification of the abdominal aorta is associated with increased cardiovascular morbidity, so a reliable method to quantify it is clinically transcendent. The 24-point scale (AAC-24) is the standard method for assessing abdominal aortic calcification on lateral plain films of the lumbar spine. The aim of this study was to determine the intraobserver and interobserver agreements for the AAC-24, taking into account the heterogeneity of the distribution of the calcifications in the design of the statistical analysis. Material and methods. We analyzed the intraobserver agreement (in plain films from 81 patients, with a four-year separation between observations) and the interobserver agreement (in plain films from 100 patients, with three observers), using both intraclass correlation and Bland-Altman plots. Results. The intraobserver intraclass correlation coefficient was 0.93 (95% confidence interval [CI95%]: 0.6-0.9), and the interobserver intraclass correlation coefficient was 0.91 (CI95%: 0.8-0.9) with an increase in the coefficient in the tercile with the greatest discrepancy. The difference in means ranged from 0.3 to 1.2 points, and the distance between the limits of agreement ranged from 4.7 to 9.4 points. These differences increased significantly as the calcification progressed. Conclusions. Using the AAC-24 on lateral plain films of the lumbar spine is a reliable and reproducible method of assessing calcification of the abdominal aorta; both intraobserver and interobserver agreement are higher during the initial phases of calcification (AU)

Reliability of radiologic evaluation of abdominal aortic calcification using the 24-point scale.

OBJECTIVE: Calcification of the abdominal aorta is associated with increased cardiovascular morbidity, so a reliable method to quantify it is clinically transcendent. The 24-point scale (AAC-24) is the standard method for assessing abdominal aortic calcification on lateral plain films of the lumbar spine. The aim of this study was to determine the intraobserver and interobserver agreements for the AAC-24, taking into account the heterogeneity of the distribution of the calcifications in the design of the statistical analysis. MATERIAL AND METHODS: We analyzed the intraobserver agreement (in plain films from 81 patients, with a four-year separation between observations) and the interobserver agreement (in plain films from 100 patients, with three observers), using both intraclass correlation and Bland-Altman plots. RESULTS: The intraobserver intraclass correlation coefficient was 0.93 (95% confidence interval [CI95%]: 0.6-0.9), and the interobserver intraclass correlation coefficient was 0.91 (CI95%: 0.8-0.9) with an increase in the coefficient in the tercile with the greatest discrepancy. The difference in means ranged from 0.3 to 1.2 points, and the distance between the limits of agreement ranged from 4.7 to 9.4 points. These differences increased significantly as the calcification progressed. CONCLUSIONS: Using the AAC-24 on lateral plain films of the lumbar spine is a reliable and reproducible method of assessing calcification of the abdominal aorta; both intraobserver and interobserver agreement are higher during the initial phases of calcification.

Characterization of caveolae from rat heart: localization of postreceptor signal transduction molecules and their rearrangement after norepinephrine stimulation.

Caveolae are plasma membrane subcompartments that have been implicated in signal transduction. In many cellular systems, caveolae are rich in signal transduction molecules such as G proteins and receptor-associated tyrosine kinases. An important structural component of the caveolae is caveolin. Recent evidence show that among the caveolin gene family, caveolin-3 is expressed in skeletal and cardiac muscle and caveolae are present in cardiac myocyte cells. Both the ANP receptor as well as the muscarinic receptor have been localized to the caveolae of cardiac myocytes in culture. These findings prompted us to conduct a further analysis of cardiac caveolae. In order to improve our understanding of the mechanisms of signal transduction regulation in cardiac myocytes, we isolated cardiac caveolae by discontinuous sucrose density gradient centrifugation from rat ventricles and rat neonatal cardiocytes. Our analysis of caveolar content demonstrates that heterotrimeric G proteins, p21ras and receptor-associated tyrosine kinases are concentrated within these structures. We also show that adrenergic stimulation induces an increase in the amount of diverse alpha- and beta-subunits of G proteins, as well as p21ras, in both in vivo and in vitro experimental settings. Our data show that cardiac caveolae are an important site of signal transduction regulation. This finding suggests a potential role for these structures in physiological and pathological states.

Early release and subsequent caspase-mediated degradation of cytochrome c in apoptotic cerebellar granule cells.

Cytochrome c (cyt c) release was investigated in cerebellar granule cells used as an in vitro neuronal model of apoptosis. We have found that cyt c is released into the cytoplasm as an intact, functionally active protein, that this event occurs early, in the commitment phase of the apoptotic process, and that after accumulation, this protein is progressively degraded. Degradation, but not release, is fully blocked by benzyloxycarbonyl-Val-Ala-Asp-fluoromethylchetone (z-VAD-fmk). On the basis of previous findings obtained in the same neuronal population undergoing excitotoxic death, it is hypothesized that release of cyt c may be part of a cellular attempt to maintain production of ATP via cytochrome oxidase, which is reduced by cytosolic NADH in a cytochrome b5-soluble cyt c-mediated fashion.

Increased cardiomyocyte apoptosis and changes in proapoptotic and antiapoptotic genes bax and bcl-2 during left ventricular adaptations to chronic pressure overload in the rat.

BACKGROUND: Left ventricular hypertrophy (LVH) represents both an adaptive response to increased cardiac work load and a precursor state of heart failure. Recent evidence linked cardiac myocyte death by apoptosis with LVH and heart failure. It remained unclear, however, whether apoptosis participated in the transition from LVH to left ventricular dysfunction (LVD). METHODS AND RESULTS: Cardiac myocyte apoptotic events and changes in apoptosis-specific genes were studied in a rat model of chronic pressure overload induced by transverse aortic constriction. The changes in left ventricular geometry and function were assessed by echocardiography. Transverse aortic constriction rats progressively developed "concentric" LVH and subsequently, LVD. A similar distribution of LVH and LVD was found 18 weeks after surgery. At this time point, we determined the occurrence of myocyte apoptosis by DNA laddering, in situ DNA TUNEL labeling, and light and electron microscopy. The monitoring of proapoptotic and antiapoptotic genes was determined by Western blot and immunohistochemistry. Our data demonstrated that cardiomyocyte apoptotic events increased from virtually undetectable (in sham-operated controls, SH) to 0.8/10(3) and 1.5/10(3) positive nuclei in LVH and LVD, respectively. Fibrosis also increased in the subendocardial and midwall regions of LVH and LVD rats compared with SH. Expression of the proapoptotic gene bax increased, whereas that of antiapoptotic gene bcl-2 decreased in LVH and LVD compared with SH. CONCLUSIONS: These data suggest that in response to chronic pressure overload, cardiomyocyte-specific apoptosis contributed to the transition from LVH to LVD. LVH and LVD were accompanied by a dramatic cardiomyocyte upregulation of the proapoptotic gene bax and reduced bcl-2/bax ratio, predisposing cardiomyocytes to apoptosis.

Induction of anti-carbohydrate antibodies by phage library-selected peptide mimics.

One of the prerequisites for the development of polysaccharide subunit vaccines is the induction of an efficient immune response to carbohydrate antigens like lipopolysaccharide (LPS) or capsular polysaccharide antigens of pathogens. In an attempt to overcome the problems that arise from the T-independent immune response induced by such antigens, selecting peptide sequences that mimic protective carbohydrate epitopes has been proposed. In this study, we investigate a new selection strategy for immunogenic peptide mimics using the phage-displayed peptide library technology. Two monoclonal antibodies (mAb) of the A isotype (mIgA), mIgA C5 and mIgA I3, specific for the O-antigen (O-Ag) part of the human pathogen Shigella flexneri serotype 5a LPS and protective against homologous infection were used to screen two phage-displayed nonapeptide libraries in pVIII. Using mIgA C5, 13 different specific clones were selected, and 6 using mIgA I3; 5 of the latter also interacted in enzyme-linked immunosorbent assay with the first mAb. All of the 19 clones selected were separately used to immunize mice, but only 2 of them, p100c (mIgA I3-specific) and p115 (interacting with both mIgA) were able to induce anti-O-Ag antibodies. The immune response was specific for the O-Ag of the S. flexneri serotype 5a, and also selectively recognized the corresponding bacterial strain. The amino acid sequences of p100c and p115 immunogenic peptide mimics were YKPLGALTH (flanked by two Cys residues) and KVPPWARTA, respectively. These results are the first example of immunogenic mimicry of carbohydrates by phage-displayed peptides, and indicate a new strategy of selection of immunogens for the development of anti-polysaccharide vaccines.

Role of PCNA in differentiating between malignant mesothelioma and mesothelial hyperplasia: prognostic considerations.

We investigated the PCNA immunoreactivity in 35 specimens of malignant mesothelioma and 20 specimens of mesothelial hyperplasia in order to evaluate the usefulness of this parameter in differentiating between these two mesothelial proliferations, and to determine whether PCNA has any prognostic significance in mesotheliomas. Eleven of the 35 investigated malignant mesotheliomas displayed up to 25% of positive cells for PCNA expression. The remaining 24 specimens showed high percentages of positive cells ranging from 26% to 95%. All specimens of reactive hyperplasia had less than 25% of PCNA positive cells. The difference between malignant mesothelioma and mesothelial hyperplasia for PCNA immunoreactivity was statistically significant (p < 0.01). A positive relationship was also found between PCNA expression level and the overall survival of those affected by malignant mesothelioma (p = 0.0032). Our results suggest on important role for PCNA in differentiating diagnosis of mesothelial proliferations. It remains unclear whether PCNA expression truly correlates with the proliferation rate of the malignant mesotheliomas and with the overall survival of patients affected by this neoplasm.