Microstructural, chemical and textural records during growth of snowball garnet

The growth history of two populations of snowball garnet from the Lukmanier Pass area (central Swiss Alps) was examined through a detailed analysis of three-dimensional geometry, chemical zoning and crystallographic orientation. The first population, collected in the hinge of a chevron-type fold, shows an apparent rotation of 360 degrees. The first 270 degrees are characterized by spiral-shaped inclusion trails, gradual and concentric Mn zoning and a single crystallographic orientation, whereas in the last 90 degrees, crenulated inclusion trails and secondary Mn maxima centred on distinct crystallographic garnet domains are observed. Microstructural, geochemical and textural data indicate a radical change in growth regime between the two growth sequences. In the first 270 degrees, growth occurred under rotational non-coaxial flow, whereas in the last 90 degrees, garnet grew under a non-rotational shortening regime. The second population, collected in the limb of the same chevron-type fold structure, is characterized by a spiral geometry that does not exceed 270 degrees of apparent rotation. These garnet microstructures do not record any evidence for a modification of the stress field during garnet growth. Concentric Mn zoning as well as a single crystallographic orientation are observed for the entire spiral. Electron backscatter diffraction data indicate that nearly all central domains in the snowball garnet are characterized by one [001] axis oriented (sub-)parallel to the symmetry axis and by another [001] axis oriented (sub-)parallel to the orientation of the internal foliation. These features suggest that the crystallographic orientation across the garnet spiral is not random and that a relation exists among the symmetry axis, the internal foliation and the crystallographic orientation.

Textural, chemical, and isotopic effects of late-magmatic carbonatitic fluids in the carbonatite-syenite Tamazeght complex, High Atlas Mountains, Morocco

Carbonatites of the Eocene Tamazeght complex, High Atlas Mountains, Morocco, consist of calciocarbonatites (alvikite and sovite dykes) and magnesiocarbonatites (diatreme breccias and dykes rocks). These are associated with ultramafic, shonkinitic, gabbroic to monzonitic and various foid syenitic silicate units. Stable and radiogenic isotope compositions for carbonatites and silicate rocks indicate that they share a common source in the mantle, although for some carbonatitic samples contamination with sedimentary rocks seems important. The observed isotopic heterogeneity is mainly attributed to source characteristics, fractional crystallization (accompanied by various degrees of assimilation), and late- to post-magmatic fluid-rock interaction. During the late fluid-rock interaction, Sr, Mn, and possibly also Fe were mobilized and redistributed to form secondary carbonate minerals in carbonatites. These fluids also penetrated into the adjacent syenitic rocks, causing enrichment in the same elements.

Dépistage et prévention chez les aînés: quelles interventions proposer, à qui, et jusqu'à quel âge [Screening and prevention in the elderly: which interventions should be proposed, to whom, and up to what age?].

Recommendations on preventive services rarely mention how to apply them to older people. Even though general criteria (prevalence of disease, quality of screening tests) that influence screening's efficacy remain important, appropriateness of screening in older persons depends much more on individual criteria, such as comorbidity, functional status, and life expectancy. More than with any other age group, patients preferences regarding future investigation and treatment guide the clinical decision. This article focuses on primary and secondary prevention, and discusses specific criteria to consider in each patient. A table summarizes the appropriate recommendations.

Multifocalité du carcinome épidermoïde sur les voies digestive supérieure et respiratoire distale : technicité du diagnostic endoscopique [Multiple squamous cell carcinoma of the upper digestive and lower respiratory tracts : methodology of endoscopic screening]

L'étude porte sur 951 porteurs d'un cancer primaire bucco-pharyngo-laryngé, et révèle un taux de multifocalité du carcinome épidermoïde sur les voies digestive supérieure (bouche-pharynx-oesophage) et aérienne distale (larynx-trachée-bronches) s'élevant à 14,5 %. Les secondes localisations peuvent être simultanées (6,4 %) ou successives (8,1 %) à la découverte du premier cancer: dès la deuxième année du follow-up leur incidence dépasse celle des récidives. Elles se localisent tant au niveau ORL (8,5 %) qu'oesophagien (3 %) ou bronchique (3 %). Le cancer du voile présente un taux de multifocalité particulièrement élevé (51 %). Les auteurs décrivent un type d'endoscopie de dépistage (bucco-pharyngo-oesophago-laryngo-trachéobronchoscopie) dont la fiabilité repose sur une technicité spécifique d'une part, et sur la connaissance des caractéristiques propres aux secondes localisations d'autre part. Ce dépistage systématique permet de détecter les tumeurs secondaires à un stade le plus souvent précoce et encore asymptomatique.

Dépistage du syndrome des apnées du sommeil [Screening for sleep apnea syndrome]

Sleep apnea syndrome (SAS) consists of nocturnal snoring interrupted by obstructive apnea and of diurnal symptoms like hypersomnolence as a consequence of sleep fragmentation. Cardiovascular morbidity and mortality associated with this syndrome justify early detection and appropriate treatment. Polysomnography is still a frequently used method for early detection; however, several disadvantages like duration, discomfort and expense led to a search for alternatives. Since the beginning of the eighties, oximetry allows recording of nocturnal oxygen saturation of hemoglobin even at home. Nocturnal oximetry reveals O2-desaturation associated with apnea and thus permits often to diagnose or exclude SAS. Diagnosis of SAS is made when at least 20 desaturations per hour with an amplitude of at least 4% are recorded. On the other hand, normal nocturnal oximetry nearly excludes SAS. In those cases where nocturnal oximetry is not diagnostic, polysomnography remains the method of choice. Departing from published work, a model for SAS detection, based mainly on nocturnal oximetry, is proposed.

Performance of blood pressure-to-height ratio at a single screening visit for the identification of hypertension in children.

BACKGROUND: The diagnosis of hypertension in children is difficult because of the multiple sex-, age-, and height-specific thresholds to define elevated blood pressure (BP). Blood pressure-to-height ratio (BPHR) has been proposed to facilitate the identification of elevated BP in children. OBJECTIVE: We assessed the performance of BPHR at a single screening visit to identify children with hypertension that is sustained elevated BP. METHOD: In a school-based study conducted in Switzerland, BP was measured at up to three visits in 5207 children. Children had hypertension if BP was elevated at the three visits. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for the identification of hypertension were assessed for different thresholds of BPHR. The ability of BPHR at a single screening visit to discriminate children with and without hypertension was evaluated with receiver operating characteristic (ROC) curve analyses. RESULTS: The prevalence of systolic/diastolic hypertension was 2.2%. Systolic BPHR had a better performance to identify hypertension compared with diastolic BPHR (area under the ROC curve: 0.95 vs. 0.84). The highest performance was obtained with a systolic BPHR threshold set at 0.80 mmHg/cm (sensitivity: 98%; specificity: 85%; PPV: 12%; and NPV: 100%) and a diastolic BPHR threshold set at 0.45 mmHg/cm (sensitivity: 79%; specificity: 70%; PPV: 5%; and NPV: 99%). The PPV was higher among tall or overweight children. CONCLUSION: BPHR at a single screening visit had a high performance to identify hypertension in children, although the low prevalence of hypertension led to a low PPV.

Influence of physico-chemical material characteristics on staphylococcal biofilm formation--a qualitative and quantitative in vitro analysis of five different calcium phosphate bone grafts.

Various compositions of synthetic calcium phosphates (CaP) have been proposed and their use has considerably increased over the past decades. Besides differences in physico-chemical properties, resorption and osseointegration, artificial CaP bone graft might differ in their resistance against biofilm formation. We investigated standardised cylinders of 5 different CaP bone grafts (cyclOS, chronOS (both β-TCP (tricalcium phosphate)), dicalcium phosphate (DCP), calcium-deficient hydroxyapatite (CDHA) and α-TCP). Various physico-chemical characterisations e.g., geometrical density, porosity, and specific surface area were investigated. Biofilm formation was carried out in tryptic soy broth (TSB) and human serum (SE) using Staphylococcus aureus (ATCC 29213) and S. epidermidis RP62A (ATCC 35984). The amount of biofilm was analysed by an established protocol using sonication and microcalorimetry. Physico-chemical characterisation showed marked differences concerning macro- and micropore size, specific surface area and porosity accessible to bacteria between the 5 scaffolds. Biofilm formation was found on all scaffolds and was comparable for α-TCP, chronOS, CDHA and DCP at corresponding time points when the scaffolds were incubated with the same germ and/or growth media, but much lower for cyclOS. This is peculiar because cyclOS had an intermediate porosity, mean pore size, specific surface area, and porosity accessible to bacteria. Our results suggest that biofilm formation is not influenced by a single physico-chemical parameter alone but is a multi-step process influenced by several factors in parallel. Transfer from in vitro data to clinical situations is difficult; thus, advocating the use of cyclOS scaffolds over the four other CaP bone grafts in clinical situations with a high risk of infection cannot be clearly supported based on our data.

Systematic molecular and cytogenetic screening of 100 patients with marfanoid syndromes and intellectual disability.

The association of marfanoid habitus (MH) and intellectual disability (ID) has been reported in the literature, with overlapping presentations and genetic heterogeneity. A hundred patients (71 males and 29 females) with a MH and ID were recruited. Custom-designed 244K array-CGH (Agilent®; Agilent Technologies Inc., Santa Clara, CA) and MED12, ZDHHC9, UPF3B, FBN1, TGFBR1 and TGFBR2 sequencing analyses were performed. Eighty patients could be classified as isolated MH and ID: 12 chromosomal imbalances, 1 FBN1 mutation and 1 possibly pathogenic MED12 mutation were found (17%). Twenty patients could be classified as ID with other extra-skeletal features of the Marfan syndrome (MFS) spectrum: 4 pathogenic FBN1 mutations and 4 chromosomal imbalances were found (2 patients with both FBN1 mutation and chromosomal rearrangement) (29%). These results suggest either that there are more loci with genes yet to be discovered or that MH can also be a relatively non-specific feature of patients with ID. The search for aortic complications is mandatory even if MH is associated with ID since FBN1 mutations or rearrangements were found in some patients. The excess of males is in favour of the involvement of other X-linked genes. Although it was impossible to make a diagnosis in 80% of patients, these results will improve genetic counselling in families.

Study of common database feeding with results coming from different analytical methods in the framework of illicit drugs chemical profiling

Analytical results harmonisation is investigated in this study to provide an alternative to the restrictive approach of analytical methods harmonisation which is recommended nowadays for making possible the exchange of information and then for supporting the fight against illicit drugs trafficking. Indeed, the main goal of this study is to demonstrate that a common database can be fed by a range of different analytical methods, whatever the differences in levels of analytical parameters between these latter ones. For this purpose, a methodology making possible the estimation and even the optimisation of results similarity coming from different analytical methods was then developed. In particular, the possibility to introduce chemical profiles obtained with Fast GC-FID in a GC-MS database is studied in this paper. By the use of the methodology, the similarity of results coming from different analytical methods can be objectively assessed and the utility in practice of database sharing by these methods can be evaluated, depending on profiling purposes (evidential vs. operational perspective tool). This methodology can be regarded as a relevant approach for database feeding by different analytical methods and puts in doubt the necessity to analyse all illicit drugs seizures in one single laboratory or to implement analytical methods harmonisation in each participating laboratory.

Cost-effectiveness of opportunistic versus organised mammography screening in Switzerland

BACKGROUND: Various centralised mammography screening programmes have shown to reduce breast cancer mortality at reasonable costs. However, mammography screening is not necessarily cost-effective in every situation. Opportunistic screening, the predominant screening modality in several European countries, may under certain circumstances be a cost-effective alternative. In this study, we compared the cost-effectiveness of both screening modalities in Switzerland. METHODS: Using micro-simulation modelling, we predicted the effects and costs of biennial mammography screening for 50-69 years old women between 1999 and 2020, in the Swiss female population aged 30-70 in 1999. A sensitivity analysis on the test sensitivity of opportunistic screening was performed. RESULTS: Organised mammography screening with an 80% participation rate yielded a breast cancer mortality reduction of 13%. Twenty years after the start of screening, the predicted annual breast cancer mortality was 25% lower than in a situation without screening. The 3% discounted cost-effectiveness ratio of organised mammography screening was euro11,512 per life year gained. Opportunistic screening with a similar participation rate was comparably effective, but at twice the costs: euro22,671-24,707 per life year gained. This was mainly related to the high costs of opportunistic mammography and frequent use of imaging diagnostics in combination with an opportunistic mammogram. CONCLUSION: Although data on the performance of opportunistic screening are limited, both opportunistic and organised mammography screening seem effective in reducing breast cancer mortality in Switzerland. However, for opportunistic screening to become equally cost-effective as organised screening, costs and use of additional diagnostics should be reduced.

Purification of recombinant proteins by chemical removal of the affinity tag.

The efficient removal of a N- or C-terminal purification tag from a fusion protein is necessary to obtain a protein in a pure and active form, ready for use in human or animal medicine. Current techniques based on enzymatic cleavage are expensive and result in the presence of additional amino acids at either end of the proteins, as well as contaminating proteases in the preparation. Here we evaluate an alternative method to the one-step affinity/protease purification process for large-scale purification. It is based upon the cyanogen bromide (CNBr) cleavage at a single methionine placed in between a histidine tag and a Plasmodium falciparum antigen. The C-terminal segment of the circumsporozoite polypeptide was expressed as a fusion protein with a histidine tag in Escherichia coli purified by Ni-NAT agarose column chromatography and subsequently cleaved by CNBr to obtain a polypeptide without any extraneous amino acids derived from the cleavage site or from the affinity purification tag. Thus, a recombinant protein is produced without the need for further purification, demonstrating that CNBr cleavage is a precise, efficient, and low-cost alternative to enzymatic digestion, and can be applied to large-scale preparations of recombinant proteins.

MRSA screening by the Xpert MRSA PCR assay: pooling samples of the nose, throat, and groin increases the sensitivity of detection without increasing the laboratory costs.

The performance of the Xpert MRSA polymerase chain reaction (PCR) assay on pooled nose, groin, and throat swabs (three nylon flocked eSwabs into one tube) was compared to culture by analyzing 5,546 samples. The sensitivity [0.78, 95 % confidence interval (CI) 0.73-0.82] and specificity (0.99, 95 % CI 0.98-0.99) were similar to the results from published studies on separated nose or other specimens. Thus, the performance of the Xpert MRSA assay was not affected by pooling the three specimens into one assay, allowing a higher detection rate without increasing laboratory costs, as compared to nose samples alone.