Oral declines and mastication deficiencies cause alteration of food bolus properties

In the elderly, masticatory function often presents failure in certain oral tasks due to impairment such as decline in muscular force, jaw or tongue motility, neuro-muscular coordination, tooth damage, malocclusion and saliva production. Great disparity is observed in the various and potentially cumulative oral declines that occur with ageing. Such difficulties may have an impact on food consumption and nutritional status. To obtain better understanding of the consequences of several oral deficiencies, a series of swallowable boluses were prepared in vitro with the AM² masticator apparatus with normal and deficient programming. Physiological normal mastication (NM) was simulated using in vivo data from healthy subjects. Chewing deficiencies were reproduced by alteration of NM programming to perform different levels and combinations of force loss, lack of saliva and decrease in the motility of oral elements. Poultry meatballs were used as test-food. Particle size distribution in the food bolus was measured by sieving and rheological features (hardness, cohesiveness and elasticity) were assessed with a TPA test. Compared to the NM outcome, significant and gradual deterioration of the food bolus was observed and associated with alteration in force, saliva and motility. Combinations of several failures led to greater or cumulative deficiencies in swallowable bolus properties. For the elderly presenting a high prevalence of various oral injuries, tailoring textured food cannot be ignored as a solution for remedying deficiencies and favoring the formation of a safe-swallowable bolus, which is an essential vector of nutrients. Knowing the impacts of oral injuries on the food bolus is obviously a requisite for developing diet strategies, including nutritional items for specific populations.

First next-generation sequencing full-genome characterization of a hepatitis C virus genotype 7 divergent subtype

We report the near-full-length genome sequence of a hepatitis C virus (HCV) isolate from a man originating from Democratic Republic of Congo, the genotype of which could not be determined by the routinely used sequencing technique. The near-complete genome sequence of this variant BAK1 was obtained by the association of two next-generation sequencing technologies. Evolutionary analysis indicates that this isolate, BAK1, could be the first reported strain belonging to a new HCV-7b subtype. This new subtype has been incorrectly identified as genotype 2 by the Versant HCV Genotype 2.0 assay (LiPA). The requirement of three independent isolates has been filled, and a new subtype can be assigned. More examples of HCV-7 are required to better understand its origin, its pathogenicity and its relationship with genotype 2.

Amplification and pyrosequencing of near-full-length hepatitis C virus for typing and monitoring antiviral resistant strains

Directly acting antiviral drugs have contributed considerable progress to hepatitis C virus (HCV) treatment, but they show variable activity depending on virus genotypes and subtypes. Therefore, accurate genotyping including recombinant form detection is still of major importance, as is the detection of resistance-associated mutations in case of therapeutic failure. To meet these goals, an approach to amplify the HCV near-complete genome with a single long-range PCR and sequence it with Roche GS Junior was developed. After optimization, the overall amplification success rate was 73% for usual genotypes (i.e. HCV 1a, 1b, 3a and 4a, 16/22) and 45% for recombinant forms RF_2k/1b (5/11). After pyrosequencing and subsequent de novo assembly, a near-full-length genomic consensus sequence was obtained for 19 of 21 samples. The genotype and subtype were confirmed by phylogenetic analysis for every sample, including the suspected recombinant forms. Resistance-associated mutations were detected in seven of 13 samples at baseline, in the NS3 (n = 3) or NS5A (n = 4) region. Of these samples, the treatment of one patient included daclatasvir, and that patient experienced a relapse. Virus sequences from pre- and posttreatment samples of four patients who experienced relapse after sofosbuvir-based therapy were compared: the selected variants seem too far from the NS5B catalytic site to be held responsible. Although tested on a limited set of samples and with technical improvements still necessary, this assay has proven to be successful for both genotyping and resistance-associated variant detection on several HCV types.

Detecting adaptive evolution based on association with ecological gradients: orientation matters!

Population genetic signatures of local adaptation are frequently investigated by identifying loci with allele frequencies that exhibit high correlation with ecological variables. One difficulty with this approach is that ecological associations might be confounded by geographic variation at selectively neutral loci. Here, we consider populations that underwent spatial expansion from their original range, and for which geographical variation of adaptive allele frequency coincides with habitat gradients. Using range expansion simulations, we asked whether our ability to detect genomic regions involved in adaptation could be impacted by the orientation of the ecological gradients. For three ecological association methods tested, we found, counter-intuitively, fewer false-positive associations when ecological gradients aligned along the main axis of expansion than when they aligned along any other direction. This result has important consequences for the analysis of genomic data under non-equilibrium population genetic models. Alignment of gradients with expansion axes is likely to be common in scenarios in which expanding species track their ecological niche during climate change while adapting to changing environments at their rear edge.

Sixty-four-row multisection CT angiography for detection and evaluation of ruptured intracranial aneurysms: interobserver and intertechnique reproducibility

BACKGROUND AND PURPOSE

The purpose of this work was to assess intertechnique and interobserver reproducibility of 64-row multisection CT angiography (CTA) used to detect and evaluate intracranial aneurysms.

MATERIALS AND METHODS

From October 2005 to November 2006, 54 consecutive patients with nontraumatic subarachnoid hemorrhage (SAH) underwent both CTA and digital substraction angiography (DSA). Four radiologists independently reviewed CT images, and 2 other radiologists reviewed DSA images. Aneurysm diameter (D), neck width (N), and the presence of a branch arising from the sac were assessed.

RESULTS

DSA revealed 67 aneurysms in 48 patients and no aneurysm in 6 patients. Mean sensitivity and specificity of CTA for the detection of intracranial aneurysms were, respectively, 94% and 90.2%. For aneurysms less than 3 mm, CTA had a mean sensitivity of 70.4%. Intertechnique and interobserver agreements were good for the detection of aneurysms (mean kappa = 0.673 and 0.732, respectively) and for the measurement of their necks (mean kappa = 0.753 and 0.779, respectively). Intertechnique and interobserver agreements were excellent for the measurement of aneurysm diameters (mean kappa = 0.847 and 0.876, respectively). In addition, CTA was accurate in determining the N/D ratio of aneurysms and adjacent arterial branches. However, the N/D ratio was overestimated by all of the readers at CTA.

CONCLUSION

Sixty-four-row multisection CTA is an imaging method with a good interobserver reproducibility and a high sensitivity and specificity for the detection and the morphologic evaluation of ruptured intracranial aneurysms. It may be used as an alternative to DSA as a first-intention imaging technique in patients with SAH.

The genetical bandwidth mapping: a spatial and graphical representation of population genetic structure based on the Wombling method

Characterizing the spatial variation of allele frequencies in a population has a wide range of applications in population genetics. This article introduces a new nonparametric method, which provides a two-dimensional representation of a structural parameter called the genetical bandwidth, which describes genetic structure around arbitrary spatial locations in a study area. This parameter corresponds to the shortest distance to areas of significant allele variation, and its computation is based on the Womble's systemic function. A simulation study and application to data sets taken from the literature give evidence that the method is particularly demonstrative when the fine-scale structure is stronger than the large-scale structure, and that it is generally able to locate genetic boundaries or clines precisely.

Long-term results of primary stenting for long and complex iliac artery occlusions

OBJECTIVES

To evaluate the long-term results of recanalization with primary stenting for long and complex iliac artery occlusions.

DESIGN

Retrospective non-randomized study.

METHODS

Between 1996 and 2004, 38 patients underwent recanalization of an occluded iliac artery with subsequent stenting for TASC B lesions in 12 patients, TASC C in 10 and TASC D in 16. Thirty-one patients had Fontaine stage 2 B, four patients had stage 3 and one patient had stage 4. Two patients (5.4%) presented with acute ischemia and received trombolysis before recanalization. Patency results were calculated using Kaplan and Meier analysis. The mean follow-up was 26 months.

RESULTS

Technical success was 97.4%. Thirty-day mortality was 2.7%. The primary patency rate was 94%, 89% and 77% at 1, 3 and 5 years respectively. Three re-occlusions (8.1%) and one restenosis (2.7%) were observed during follow-up. The secondary patency (SP) rate was 100%, 94% and 94% after 1, 2 and 3 years. Fifteen patients underwent an associated procedure. A kissing stent procedure in three patients, a contralateral PTA of an iliac stenosis in 8, a femoro-femoral bypass in 2, a femoropopliteal bypass in 1 and an femoral endarterectomy in 2. The procedure related complication rate was 5.4%.

CONCLUSION

Long-term results of iliac recanalization are excellent without major complications if the procedure is technically successful. The endovascular procedure can be an alternative to an iliofemoral or aortobifemoral bypass in a high risk population.

Assumed and inferred spatial structure of populations: the Scandinavian brown bears revisited

We reanalysed the spatial structure of the Scandinavian brown bear (Ursus arctos) population based on multilocus genotypes. We used data from a former study that had presumed a priori a specific population subdivision based on four subpopulations. Using two independent methods (neighbour-joining trees and Bayesian assignment tests), we analysed the data without any prior presumption about the spatial structure. A subdivision of the population into three subpopulations emerged from our study. The genetic pattern of these subpopulations matched the three geographical clusters of individuals present in the population. We recommend considering the Scandinavian brown bear population as consisting of three (instead of four) subpopulations. Our results underline the importance of determining genetic structure from the data, without presupposing a structure, even when there seems to be good reason to do so.

Parameter estimation in a model for multidimensional recording of neuronal data: a Gibbsian approximation approach

This article proposes improved numerical procedures for estimating parameters in a spatiotemporal lattice model introduced for the analysis of cortical activities monitored from arrays of diodes. The numerical algorithms are based on approximations inspired by statistical physics. Both Gibbsian and mean-field approximations are used; they allow for computing local conditional probabilities inside the lattice. The statistical procedures rely on the computation of pseudomaximum-likelihood estimators. The estimators are evaluated on the basis of Monte Carlo simulations. These simulations show that mean-field approximations are useful for reducing the variance of estimators when the data are recorded from arrays of 144 diodes (which are in accordance with standard practice). In light of these improved methods, we give new interpretations for a data set obtained from optical recording of a Guinea pig's auditory cortex in response to pure tone stimulations.

Statistical procedures for spatiotemporal neuronal data with applications to optical recording of the auditory cortex

This article presents new procedures for multisite spatiotemporal neuronal data analysis. A new statistical model - the diffusion model - is considered, whose parameters can be estimated from experimental data thanks to mean-field approximations. This work has been applied to optical recording of the guinea pig's auditory cortex (layers II-III). The rates of innovation and internal diffusion inside the stimulated area have been estimated. The results suggest that the activity of the layer balances between the alternate predominance of its innovation process and its internal process.

Pulmonary and mediastinal lesions in children with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is an uncommon group of disorders affecting mainly children and young adults. In children, pulmonary involvement occurs mostly in the disseminated forms; isolated pulmonary lesions are unusual. A retrospective study was undertaken on a group of 42 children diagnosed with LCH over a 19-year period. Eight children (19 %) had radiological evidence of pulmonary involvement. The lung lesions were either present at the time of diagnosis or, when appearing during the course of the disease, always coinciding with exacerbation or recurrence of the disease in other sites. Lung involvement did not appear to be an unfavourable prognostic factor. However, the toxic effects of treatment on the lungs might lead to important pulmonary sequelae.

[The tumorous form of bladder malacoplakia. Apropos of 2 cases]

The authors report two rare cases of neoplastic vesical malakoplakia, one with an enterovesical fistula and the other with extravesical pelvic extension. The symptoms are non-specific and the diagnosis remains histological. Medical treatment, based on the suspected infectious physiopathogenesis of the disease, consists of variable combinations of antibiotics, cholinergics and vitamin C. It must be sufficiently prolonged and conservative in view of its usual efficacy, even in neoplastic forms.

[Pelvic lipomatosis. A case with ureteral and venous obstruction]

The authors report a case of pelvic lipomatosis in a 62 year old man associated with venous obstruction (third case reported in the literature), diagnosed after bilateral ureteric obstruction, and review of the literature on this subject. The diagnosis was suggested by the radiological triad of hyperlucency of the pelvis on plain abdominal X-ray, "hot air balloon" appearance of the bladder on IVU and a rigid and ascended rectosigmoid on barium enema, and was confirmed by CT and MRI. Treatment combining corticosteroids and urinary tract disinfection was partially effective. A double J ureteric stent resolved the problem of persistent right ureteric obstruction.

[Circulating prostate cancer specific antigens in benign hypertrophy and localized cancer of the prostate]

In benign hypertrophy of the prostate (88 patients) there is a good correlation between the circulating specific prostate antigen (SPA) and the size of the prostate or of the adenoma. This correlation disappears with an adenocarcinoma where tumor volume increases (46 patients). Used as a screening test for cancer, serum levels of SPA, with a threshold value of 2.5 ng/ml, has a 91 per cent sensitivity and a 37 per cent specificity. At 15 ng/ml the sensitivity is 50 per cent and the specificity is 85 per cent. Alone, the SPA level is a poor diagnostic tool: using the low threshold (2.5 ng/ml) leads to needle biopsy in most all benign hypertrophies; with the high threshold (15-23 ng/ml), 50 per cent of the localized cancers go undetected. However, for a level greater than 15 ng/ml, SPA is an argument strongly suggesting prostate adenocarcinoma. The capacity of benign hypertrophy of the prostate to "secrete" SPA is 5 times greater than the normal peripheral prostate; the capacity of cancer is 20 times greater than that of the adenoma. Individual variability in serum levels of SPA, expressed per cm3 of prostate tissue is too great to give a precise interpretation as a function of volume.