Digital Evaluation of Trueness and Precision of Modern Impression Materials in Implant- Retained Mandibular Overdentures.

INTRODUCTION: The purpose of this in vitro study was to evaluate the dimensional accuracy, trueness, and precision of vinyl siloxane ether (VSXE) and polyvinylsiloxane (PVS) impression materials using different impression techniques. MATERIAL AND METHODS: A three-dimensional (3D) printed mandibular model with implants and metal rods served as the reference model. Impressions were taken in custom trays, resulting in four groups: PVS-closed-tray, VSXE-closed-tray, PVS-open-tray, and VSXE-open-tray. The reference model and impressions were scanned and analyzed using 3D analysis software to assess the trueness and precision within each group. RESULTS: There was significant difference in trueness between the groups, with PVS closed tray showing a higher deviation than VSXE-closed-tray and PVS-open-tray. VSXE-open-tray had the lowest deviation, which was statistically significant. In terms of precision, PVS-closed-tray showed the highest deviation, while no significant differences were found among the other groups. CONCLUSIONS: VSXE impression material with an open tray technique consistently demonstrated the highest levels of accuracy and precision. Conversely, PVS impression material with a closed tray technique yielded less favorable results. CLINICAL RELEVANCE: Better understanding of trueness and precision of new impression materials with new impression techniques will increase their clinical effectiveness.

Perfusion MRI-Based Fractional Tumor Burden Differentiates between Tumor and Treatment Effect in Recurrent Glioblastomas and Informs Clinical Decision-Making.

BACKGROUND AND PURPOSE: Fractional tumor burden better correlates with histologic tumor volume fraction in treated glioblastoma than other perfusion metrics such as relative CBV. We defined fractional tumor burden classes with low and high blood volume to distinguish tumor from treatment effect and to determine whether fractional tumor burden can inform treatment-related decision-making. MATERIALS AND METHODS: Forty-seven patients with high-grade gliomas (primarily glioblastoma) with recurrent contrast-enhancing lesions on DSC-MR imaging were retrospectively evaluated after surgical sampling. Histopathologic examination defined treatment effect versus tumor. Normalized relative CBV thresholds of 1.0 and 1.75 were used to define low, intermediate, and high fractional tumor burden classes in each histopathologically defined group. Performance was assessed with an area under the receiver operating characteristic curve. Consensus agreement among physician raters reporting hypothetic changes in treatment-related decisions based on fractional tumor burden was compared with actual real-time treatment decisions. RESULTS: Mean lower fractional tumor burden, high fractional tumor burden, and relative CBV of the contrast-enhancing volume were significantly different between treatment effect and tumor (P = .002, P < .001, and P < .001), with tumor having significantly higher fractional tumor burden and relative CBV and lower fractional tumor burden. No significance was found with intermediate fractional tumor burden. Performance of the area under the receiver operating characteristic curve was the following: high fractional tumor burden, 0.85; low fractional tumor burden, 0.7; and relative CBV, 0.81. In comparing treatment decisions, there were disagreements in 7% of tumor and 44% of treatment effect cases; in the latter, all disagreements were in cases with scattered atypical cells. CONCLUSIONS: High fractional tumor burden and low fractional tumor burden define fractions of the contrast-enhancing lesion volume with high and low blood volume, respectively, and can differentiate treatment effect from tumor in recurrent glioblastomas. Fractional tumor burden maps can also help to inform clinical decision-making.

Bayesian adaptation of chaos representations using variational inference and sampling on geodesics.

A novel approach is presented for constructing polynomial chaos representations of scalar quantities of interest (QoI) that extends previously developed methods for adaptation in Homogeneous Chaos spaces. In this work, we develop a Bayesian formulation of the problem that characterizes the posterior distributions of the series coefficients and the adaptation rotation matrix acting on the Gaussian input variables. The adaptation matrix is thus construed as a new parameter of the map from input to QoI, estimated through Bayesian inference. For the computation of the coefficients' posterior distribution, we use a variational inference approach that approximates the posterior with a member of the same exponential family as the prior, such that it minimizes a Kullback-Leibler criterion. On the other hand, the posterior distribution of the rotation matrix is explored by employing a Geodesic Monte Carlo sampling approach, consisting of a variation of the Hamiltonian Monte Carlo algorithm for embedded manifolds, in our case, the Stiefel manifold of orthonormal matrices. The performance of our method is demonstrated through a series of numerical examples, including the problem of multiphase flow in heterogeneous porous media.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in Egyptian children with systemic lupus erythematosus: a possible relation to proliferative nephritis.

Introduction Angiotensin-converting enzyme (ACE) is crucial in the pathogenesis of systemic lupus erythematosus through angiotensin II which regulates vascular tone and endothelial functions. Objectives To study the frequency of ACE insertion/deletion (I/D) gene polymorphism in Egyptian children with systemic lupus erythematosus and its possible relation to the renal pathology in cases with lupus nephritis. Subjects and methods The frequency of ACE gene insertion/deletion polymorphism genotypes was determined in 78 Egyptian children with systemic lupus erythematosus and compared to a matched group of 140 healthy controls using polymerase chain reaction. Results The DD genotype of the ACE gene was higher in systemic lupus erythematosus patients when compared to controls ( P<0.0001; odds ratio (OR) 2.4; 95% confidence interval (CI) 1.7-3.3) and the D allele was more frequent than the I allele in systemic lupus erythematosus patients in comparison to controls ( P < 0.0001; OR = 2.2; 95% CI = (1.6-3.1). In the lupus nephritis group, the DD genotype was significantly higher in those with proliferative lupus nephritis when compared to those with non-proliferative lupus nephritis ( P = 0.02; OR = 1.45; 95% CI = 1.4-1.6). Also, patients with proliferative lupus nephritis showed a higher frequency of the D allele ( P < 0.001; OR = 1.98; 95% CI = 1.3-2.9). Conclusion The D allele and DD genotype of the ACE gene appear to be a risk factor for the susceptibility of systemic lupus erythematosus and occurrence of proliferative nephritis in Egyptian children.

Risk factors for postoperative infections in patients with hip fracture treated by means of Thompson arthroplasty.

Specific conditions associated with surgery may predispose elderly people to septic complications after hip fracture surgery. This study investigated the risk factors predisposing infection in aged patients with subcapital hip fracture. We performed a prospective study of 290 patients with displaced subcapital hip fracture, operated by means of Thompson hip hemi-arthroplasty (83.5% fractures in women). The mean age was 85.42+/-6.06 years (ranging from 69 to 104). Follow-up was realized until death or at least for 2 years. The chi(2) test, analysis of variance, Kruskal-Wallis test, correlation analysis and the Spearman test were applied. Odds ratios (OR) were calculated. During the hospital stay, there were diagnosed 94 urinary tract infections, 25 pneumonias, 50 superficial wound infections, 11 deep wound infections. Transfusions were made in 120 patients (in average: 2.54+/-1.45 units of red cell concentrate/transfused patient). Transfusion appeared to be correlated with superficial wound infection (OR=1.96), urinary infection (OR=1.76) and pneumonia (OR=2.85). Higher number of days waiting for surgery were related significantly with pneumonia (9.8+/-7.44 days vs. 6.39+/-3.75), or urinary tract infection (7.76+/-4.39 days vs. 6.17+/-4.14). We concluded that the transfusion and longer waiting time for surgery have been associated with the septic complications in elderly patients treated surgically for hip fracture.

Estado inmunológico de ancianos candidatos a artroplastia tras fractura subcapital de cadera: estudio de su relación con la edad y con la morbimortalidad postoperatoria* / Immunological status of elderly patients eligible for arthroplasty after a femoral neck fracture: relationship between the patients' status, their age and postoperative morbimortality

Objetivo. Analizar la relación de la situación inmunológica preoperatoria tras fractura subcapital de cadera con las complicaciones postoperatorias. Material y método. Estudio prospectivo aleatorio de 94 pacientes (81 mujeres) con fractura subcapital de cadera Garden IV (edad media: 82,9 años (± 7,48), máximo: 100, mínimo: 64 años). Al ingreso se determinó en sangre venosa periférica: fórmula leucocitaria, inmunoglobulinas (IgG, IgA, IgM e IgE), CD19, CD3, CD4, CD8, niveles de transferrina, alfa-2-macroglobulina, ceruloplasmina, proteína transportadora de retinol, prealbúmina, albúmina, proteínas totales, colesterol total y triglicéridos. Se estudiaron las complicaciones postoperatorias. En la estadística se realizó análisis de la varianza y Chi cuadrado. Resultados. Se detectaron 12 casos de infección de la herida quirúrgica, 27 casos de infección de orina, 3 casos de neumonía y una infección periprotésica. Los pacientes con infección postoperatoria presentaron en el preoperatorio menores niveles de IgM (infección de orina y neumonía), de IgA (neumonía) y de IgE (infección de la herida), menor número de CD4 y CD8/mm3 (infección de orina y neumonía) y un menor porcentaje de CD19 (infección de herida). La albúmina, la prealbúmina, el colesterol total, los triglicéridos y la transferrina disminuyeron significativamente con la edad. Conclusiones. La IgM, la IgA, la IgE, el porcentaje de CD19 y el número de CD4 y CD8 podrían servir como indicadores de un mayor riesgo de desarrollar infecciones durante el postoperatorio de una fractura subcapital de cadera

Purpose. To analyze the relationship between a patient's immunological status prior to arthroplasty secondary to a femoral neck fracture and postoperative complications. Materials and methods. Prospective randomized study of 94 patients (81 of which female) with a Garden IV femoral neck fracture (mean age: 82.9 years (± 7.48), range: 100-64). On admission, the following parameters were evaluated in the patients' peripheral venous blood: differential leukocyte count; inmunoglobulin (IgG, IgA, IgM and IgE); percentage of CD19, CD3, CD4 and CD8; transferrin levels; alfa-2-macroglobulin; ceruloplasmin; retinol transport protein; prealbumin; albumin; total proteins; total cholesterol and triglycerides. Postoperative complications were studied. Statistics: Variance and chi square analysis. Results. There were twelve cases of surgical wound infection, 27 of urinary infection, 3 cases of pneumonia and one periprosthetic infection. Patients with a postoperative infection had lower preop levels of IgM (urinary infection and pneumonia), IgA (pneumonia) and IgE (wound infection), as well as a lower count of CD4 and CD8 per cubic mm (urinary infection and pneumonia) and a lower percentage of CD19 (wound infection). Albumin, prealbumin, total cholesterol, triglycerides and transferrin decreased significantly with age. Conclusions. The IgM, IgA, IgE, the CD19 percentage and CD4 and CD8 counts could be used indicators of a higher risk of developing infections after surgery for a femoral neck fracture (AU)

Coarse graining the dynamics of coupled oscillators.

We present an equation-free computational approach to the study of the coarse-grained dynamics of finite assemblies of nonidentical coupled oscillators at and near full synchronization. We use coarse-grained observables which account for the (rapidly developing) correlations between phase angles and natural frequencies. Exploiting short bursts of appropriately initialized detailed simulations, we circumvent the derivation of closures for the long-term dynamics of the assembly statistics.

Consumo moderado de alcohol y mortalidad por diversas causas / Moderate alcohol consumption and mortality for various reasons

No disponible

Apoplejía hipofisaria / Pituitary apoplexy

La apoplejía hipofisaria es una complicación poco frecuente de los adenomas de hipófisis, producida por un infarto hemorrágico o isquémico en el adenoma y con una clínica característica: cefalea intensa de comienzo agudo, alteraciones visuales y somnolencia o coma. En los últimos 10 años hemos tratado a 8 pacientes con apoplejía hipofisaria. El diagnóstico fue clínico: 7 presentaron cefalea intensa y vómitos, 8 alteraciones visuales y 1 disminución del nivel de conciencia asociado a síndrome meníngeo. En 6 casos, la apoplejía fue la primera manifestación del adenoma de hipófisis. La resonancia magnética y la tomografía computada demostraron el ictus hipofisario en 7 pacientes. La cirugía descompresiva transesfenoidal se efectuó en 7 casos, sólo en uno de urgencia. Todos presentaron una significativa recuperación de las alteraciones visuales, sin embargo, en ninguno se observó mejoría de las alteraciones endocrinológicas preoperatorias. Consideramos que el diagnóstico precoz, el rápido inicio del tratamiento hormonal sustitutivo y la cirugía transesfenoidal urgente o diferida en función de la clínica, deben ser la base del tratamiento adecuado de la apoplejía hipofisaria (AU)

[Pituitary apoplexy]. / Apoplejía hipofisaria.

Pituitary apoplexy is an infrequent complication of pituitary adenomas, caused by hemorrhagic or ischemic infarction in the tumor, with typical clinical presentation: severe headache of sudden onset, visual disturbances, sleep tendency or comma. Along the last ten years we have treated eight patients with pituitary apoplexy. The diagnostic was clinically established in all of them. Seven cases complained of severe headache and vomiting. Eight patients reported visual disturbances. In one case low level of consciousness and meningeal irritation were the only findings. In six cases the apoplexy was the first pituitary adenoma manifestation. MRI and CT studies demonstrated the pituitary stroke in seven patients. Surgical trans-sphenoidal decompression was performed in seven patients, requiring urgent management in only one case. All patients experienced a marked visual improvement, but there was no amelioration of endocrine preoperative disturbances in any case. We conclude that quick diagnosis, early onset of hormonal therapy and urgent or delayed trans-sphenoidal surgery, depending on clinical manifestations, constitute the principies of the appropriate treatment of pituitary apoplexy.

[Holoprosencephaly: morphological aspects of twelve cases of autopsy]. / Holoprosencefalia: análise do seu espectro morfológico em doze casos de autópsia.

The term holoprosencephaly (HPC) is used to indicate the group of hemispheric deformities caused by a failure in the development of the prosencephalic vesicle. The purpose of this study is to explain the morphologic spector of twelve cases of HPC, qualify them, and compare them to the literature. It was evaluated 5837 pediatrics necropsies, and there were 12 cases of HPC. Data like gender, age and the presence of another associated malformations were evaluated and compared to another malformations and to the total number of necropsies. The majority of the cases was male (66.66%), and stillborns (75%). The most frequently type of HPC found was the lobar type (58.3%), and the most frequently type of facial alteration was the ciclopy (25%). There is a statistic tendency to HPC affect the male sex, in comparison with other neurologic malformations. Besides, the stillborns are more frequently observed in HPC than in other neurologic malformations.

Imaging dispersion of myocardial repolarization, I: comparison of body-surface and epicardial measures.

BACKGROUND: Body-surface ECG measures (QT dispersion [QTd], QRST integrals) have been used as indices of myocardial repolarization abnormalities with the goal of identifying patients at risk of fatal arrhythmias. The clinical utility of these measures has been questioned. We investigate the complex relationship between epicardial and body-surface potentials in the context of regionally abnormal myocardial repolarization. METHODS AND RESULTS: Epicardial potentials were recorded with a 224-electrode sock from an open-chest dog during control, regional epicardial warming, cooling, and adjacent warming and cooling to induce localized alterations in myocardial repolarization and regions of increased repolarization dispersion. Body-surface potentials were generated from these epicardial potentials in a human torso model. Epicardial estimates of repolarization (activation recovery intervals [ARIs] and QRST integrals) were evaluated for their ability to identify regions with increased repolarization dispersion. Body-surface QRST integrals and QTd in 12-lead ECG and 64-lead body-surface potential maps were evaluated for their ability to detect increased dispersion of myocardial repolarization. Epicardial ARI and QRST integral maps successfully located epicardial regions with increased dispersion of repolarization. The increased dispersion was not consistently reflected in the 12-lead or 64-lead ECG QTd or in the body-surface QRST integral maps. CONCLUSIONS: This study demonstrates the inadequacy of body-surface measures that are thought to reflect myocardial dispersion of repolarization. In contrast, measures based on epicardial electrograms (ARI or epicardial QRST integral maps) provide physiologically relevant information about myocardial repolarization and can locate regions of increased dispersion.

Imaging dispersion of myocardial repolarization, II: noninvasive reconstruction of epicardial measures.

BACKGROUND: Dispersion of myocardial repolarization supports the development and maintenance of life-threatening arrhythmias. Current noninvasive approaches for detecting substrates with increased dispersion based on ECG measures (eg, QT dispersion) have shown limited success and inconsistencies. The companion article shows that, in contrast, epicardial potentials and derived measures reflect local dispersion of repolarization. Here, using a recently developed ECG imaging method, we evaluate the feasibility of noninvasive reconstruction of such epicardial measures from body-surface ECG data. METHODS AND RESULTS: Epicardial potentials were recorded with a 224-electrode sock from an open-chest dog during control, regional warming, cooling, and simultaneous adjacent warming and cooling to induce localized changes in myocardial repolarization and regions of increased dispersion. Body-surface potentials were generated from these epicardial potentials in a human torso model. Realistic geometric errors and measurement noise were added to the torso data, which were then used to noninvasively reconstruct epicardial measures of repolarization dispersion (activation recovery intervals [ARIs] and QRST integrals). Repolarization properties were accurately depicted by ECG imaging, including (1) shortened ARIs and increased QRST integrals over the warmed region, (2) prolonged ARIs and decreased QRST integrals over the cooled region, and (3) high gradients of ARIs and QRST integrals over the adjacent warmed and cooled regions. CONCLUSIONS: ECG imaging can reconstruct repolarization properties accurately and localize areas of increased dispersion of repolarization in the heart noninvasively. Its clinical significance lies in the possibility of noninvasive risk stratification and in guidance and evaluation of therapy.

An interactive graphical system for automated mapping and display of cardiac rhythms.

Electrical cardiac mapping has been used to study the mechanisms of cardiac arrhythmias, to assist in clinical diagnosis of rhythm disorders, to guide interventional procedures, or to evaluate the effects of antiarrhythmic drugs. Manual determination of local activation times, the first step in constructing activation maps, is a time-consuming process that precludes the possibility of on-line interactive mapping during an electrophysiologic experiment or a clinical procedure. This report describes an interactive graphic user interface application that (1) automatically determines the activation sequences with good accuracy, (2) displays graphical presentations of activation maps within seconds, and (3) allows manual interactive adjustments. Five automated activation time detection algorithms, one for bipolar electrograms and four for unipolar electrograms, were evaluated and compared. High-density canine recordings were used to evaluate the accuracy of the system. Data included normal atrial activation (sinus rhythm) and abnormal reentrant atrial activation (atrial flutter).

Determination of beta-blocker drugs in pharmaceutical preparations by non-suppressed ion chromatography.

A rapid and feasible chromatographic method for determining atenolol, metoprolol, alprenolol, oxprenolol, acebutolol and propranolol by non-suppressed ion chromatography is proposed. The mobile phase consisted of 50 mM nitric acid in an aqueous solution of 4% (v/v) acetonitrile. Detection limits are in the range 0.1-2.7 mg l-1. The method was successfully applied to the determination of beta-blockers in several pharmaceutical formulations.

Nonlinear control techniques for dynamical systems with uncertain parameters

The present report explores various approaches for controlling nonlinear uncertaim dynamical system. Several models representing different types of nonlinearities in such systems are considered. In particular, the Duffing oscillator and a system coupled to an electro-rheological device are considered. This latter system nonlinearity is characterized by a nonlinear force versus velocity relationship which is itself a function of an external voltage applied across the device. The control objectives considered in the present study consist of trajectory tracking (AU)

[The application of evoked potentials to the evolutive control of continuous spike/wave epilepsy during slow wave sleep]. / Aplicación de los potenciales evocados al control evolutivo de la epilepsia punta onda continua durante el sueño de ondas lentas.

We studied 4 patients (14-21 years old) with continuous spike/wave epilepsy during slow wave sleep with visual evoked potentials (VEP) and somatosensory evoked potentials (SEP). All the patients presented the same focality and received the same medication (primidone plus sodium valproate). No case had another pathology not related with epilepsy which could alter the evoked potential findings. The results obtained in the initial evoked potentials were compared with those achieved after 5 years of treatment. In the initial study interhemispheric asymmetry in the latency of the early component (L.N1) of the SEP was observed with a mean of 10%. Five years later normal SEP were obtained with the asymmetry having disappeared thus leading to the deduction that the physiopathologic improvement found in these patients was due to the treatment of sodium valproate together with primidone.

The increase in erythrocyte deformability in patients treated with nicardipine or nimodipine.

A study was made of a total of 50 patients, 36 females and 14 males, with an average age of 51.3 +/- 11.71 years (range 19-71). The group consisted of outpatients who came to the neurology clinic suffering from vascular headache or other symptomatic complaint of vascular type. In all cases, the existence of an organic neurological pathology had been considered and rejected. All patients who were smokers or suffering from hypertension were excluded, as well as those who had abnormal lipid or glucose values or who were on drug treatment for other reasons. The basal erythrocyte deformability value was determined and the patients divided into two random homogeneous groups. One of the groups was treated with nimodipine (90 mg/d) and the other with nicardipine (60 mg/d) for a period of two months. After this treatment period a further determination of the erythrocyte deformability was carried out. In the group treated with nimodipine, the erythrocyte deformability varied from 45.5 +/- 7.4 mcl/s to 50.35 +/- 12.02 mcl/s (p = 0.07123). In the group treated with nicardipine, these values varied from 45.96 +/- 7.35 mcl/s to 56.21 +/- 12.72 mcl/s (p = 0.00079). It was concluded that in both groups of patients, after two months treatment with these calcium antagonists, there was an improvement in erythrocyte deformability and, therefore, in blood fluidity, although only the nicardipine-treated group reached statistically significant levels.