Vitamin D-Binding Protein Deficiency and Homozygous Deletion of the GC Gene.

A 58-year-old woman with debilitating ankylosing spondylitis who was born to consanguineous parents was found to have an apparent severe vitamin D deficiency that did not respond to supplementation. Liquid chromatography-tandem mass spectrometry showed the absence of circulating vitamin D-binding protein, and chromosomal microarray confirmed a homozygous deletion of the group-specific component (GC) gene that encodes the protein. Congenital absence of vitamin D-binding protein resulted in normocalcemia and a relatively mild disruption of bone metabolism, in this case complicated by severe autoimmune disease. (Funded by the National Institutes of Health and the University of Washington.).

Tatton-Brown-Rahman syndrome: Six individuals with novel features.

Tatton-Brown Rahman syndrome (TBRS) is an overgrowth-intellectual disability syndrome caused by heterozygous variants in DNMT3A. Seventy-eight individuals have been reported with a consistent phenotype of somatic overgrowth, mild to moderate intellectual disability, and similar dysmorphisms. We present six individuals with TBRS, including the youngest individual thus far reported, first individual to be diagnosed with tumor testing and two individuals with variants at the Arg882 domain, bringing the total number of reported cases to 82. Patients reported herein have additional clinical features not previously reported in TBRS. One patient had congenital diaphragmatic hernia. One patient carrying the recurrent p.Arg882His DNMT3A variant, who was previously reported as having a phenotype due to a truncating variant in the CLTC gene, developed a ganglioneuroblastoma at 18 months and T-cell lymphoblastic lymphoma at 6 years of age. Four patients manifested symptoms suggestive of autonomic dysfunction, including central sleep apnea, postural orthostatic hypotension, and episodic vasomotor instability in the extremities. We discuss the molecular and clinical findings in our patients with TBRS in context of existing literature.

[Comparing outcomes of Immediate Breast reconstruction with and without use of radiotherapy]. / Comparaison des résultats de reconstruction mammaire immédiate par prothèse avec et sans radiothérapie.

BACKGROUND: Breast cancer and its treatment remains a public health problem. There is still a lack of epidemiological data concerning complications and aesthetic results bound to radiotherapy after an immediate breast reconstruction. The objective of this study was to compare outcomes of immediate breast reconstruction regardless to the use of radiotherapy (history of radiotherapy or adjuvant radiation therapy), in order to determine risk factor of complications and bad aesthetic results. METHODS: We conducted a retrospective study between January 2014 and December 2016 at the hospital "Gustave Roussy" in Paris, concerning breast cancer patients who needed immediate breast reconstruction after total mastectomy. The primary endpoint was to assess the failure rate of reconstruction and the aesthetic result, the secondary endpoint assessed the early and late rate of complications. We realized a multivariate analysis in order to identify risks factors that may predict complications. RESULTS: Three hundred and thirty three patients have been included: 157 in the "radiotherapy group" compared to 176 in the "no radiotherapy group". Preoperative characteristics were comparable. Average follow-up was between 1 and 3years without missing. Patients who benefited from radiotherapy had an equal risk failure of reconstruction. The subgroup analysis revealed non-significant differences: 12.7% failure rate reconstruction in the "radiotherapy group" vs. 12.5%. We could notify a better rate of "excellent results" in the "no radiotherapy group": 35% vs. 8.2%. Secondary outcomes were comparable. CONCLUSIONS: Radiotherapy related to immediate breast reconstruction didn't increase the failure rate of reconstruction or aesthetic results, comparatively to non-irradiated patients. It is therefore permissible to suggest an immediate breast reconstruction to any patients which would benefit from a total mastectomy followed by radiotherapy; in order to prevent them from a secondary breast reconstruction, who could be physically and psychologically more impactful.

A novel mutation in two Hmong families broadens the range of STRA6-related malformations to include contractures and camptodactyly.

PDAC (also termed Matthew Wood) syndrome is a rare, autosomal recessive disorder characterized by pulmonary hypoplasia/aplasia, diaphragmatic defects, bilateral anophthalmia, and cardiac malformations. The disorder is caused by mutations in STRA6, an important regulator of vitamin A and retinoic acid metabolism. We describe six cases from four families of Hmong ancestry, seen over a 30 years period in California. These include: (i) consanguineous siblings with a combination of bilateral anophthalmia, diaphragmatic abnormalities, truncus arteriosus, and/or pulmonary agenesis/hypoplasia; (ii) a singleton fetus with bilateral anophthalmia, pulmonary agenesis, cardiac malformation, and renal hypoplasia; (iii) a sibling pair with a combination of antenatal contractures, camptodactyly, fused palpebral fissures, pulmonary agenesis, and/or truncus arteriosus; (iv) a fetus with bilateral anophthalmia, bushy eyebrows, pulmonary agenesis, heart malformation, and abnormal hand positioning. The phenotypic spectrum of PDAC syndrome has until now not included contractures or camptodactyly. Sequencing of STRA6 in unrelated members of families three and four identified a novel, shared homozygous splice site alteration (c.113 + 3_4delAA) that is predicted to be pathogenic. We hypothesize this may represent a unique disease allele in the Hmong. We also provide a focused review of all published PDAC syndrome cases with confirmed or inferred STRA6 mutations, illustrating the phenotypic and molecular variability that characterizes this disorder.

Thin film depth profiling by ion beam analysis.

The analysis of thin films is of central importance for functional materials, including the very large and active field of nanomaterials. Quantitative elemental depth profiling is basic to analysis, and many techniques exist, but all have limitations and quantitation is always an issue. We here review recent significant advances in ion beam analysis (IBA) which now merit it a standard place in the analyst's toolbox. Rutherford backscattering spectrometry (RBS) has been in use for half a century to obtain elemental depth profiles non-destructively from the first fraction of a micron from the surface of materials: more generally, "IBA" refers to the cluster of methods including elastic scattering (RBS; elastic recoil detection, ERD; and non-Rutherford elastic backscattering, EBS), nuclear reaction analysis (NRA: including particle-induced gamma-ray emission, PIGE), and also particle-induced X-ray emission (PIXE). We have at last demonstrated what was long promised, that RBS can be used as a primary reference technique for the best traceable accuracy available for non-destructive model-free methods in thin films. Also, it has become clear over the last decade that we can effectively combine synergistically the quite different information available from the atomic (PIXE) and nuclear (RBS, EBS, ERD, NRA) methods. Although it is well known that RBS has severe limitations that curtail its usefulness for elemental depth profiling, these limitations are largely overcome when we make proper synergistic use of IBA methods. In this Tutorial Review we aim to briefly explain to analysts what IBA is and why it is now a general quantitative method of great power. Analysts have got used to the availability of the large synchrotron facilities for certain sorts of difficult problems, but there are many much more easily accessible mid-range IBA facilities also able to address (and often more quantitatively) a wide range of otherwise almost intractable thin film questions.

Congenital sucrase-isomaltase deficiency: identification of a common Inuit founder mutation.

BACKGROUND: Congenital sucrase-isomaltase deficiency is a rare hereditary cause of chronic diarrhea in children. People with this condition lack the intestinal brush-border enzyme required for digestion of di- and oligosaccharides, including sucrose and isomaltose, leading to malabsorption. Although the condition is known to be highly prevalent (about 5%-10%) in several Inuit populations, the genetic basis for this has not been described. We sought to identify a common mutation for congenital sucrase-isomaltase deficiency in the Inuit population. METHODS: We sequenced the sucrase-isomaltase gene, SI, in a single Inuit proband with congenital sucrase-isomaltase deficiency who had severe fermentative diarrhea and failure to thrive. We then genotyped a further 128 anonymized Inuit controls from a variety of locales in the Canadian Arctic to assess for a possible founder effect. RESULTS: In the proband, we identified a novel, homozygous frameshift mutation, c.273_274delAG (p.Gly92Leufs*8), predicted to result in complete absence of a functional protein product. This change was very common among the Inuit controls, with an observed allele frequency of 17.2% (95% confidence interval [CI] 12.6%-21.8%). The predicted Hardy-Weinberg prevalence of congenital sucrase-isomaltase deficiency in Inuit people, based on this single founder allele, is 3.0% (95% CI 1.4%-4.5%), which is comparable with previous estimates. INTERPRETATION: We found a common mutation, SI c.273_274delAG, to be responsible for the high prevalence of congenital sucrase-isomaltase deficiency among Inuit people. Targeted mutation testing for this allele should afford a simple and minimally invasive means of diagnosing this condition in Inuit patients with chronic diarrhea.

Certified ion implantation fluence by high accuracy RBS.

From measurements over the last two years we have demonstrated that the charge collection system based on Faraday cups can robustly give near-1% absolute implantation fluence accuracy for our electrostatically scanned 200 kV Danfysik ion implanter, using four-point-probe mapping with a demonstrated accuracy of 2%, and accurate Rutherford backscattering spectrometry (RBS) of test implants from our quality assurance programme. The RBS is traceable to the certified reference material IRMM-ERM-EG001/BAM-L001, and involves convenient calibrations both of the electronic gain of the spectrometry system (at about 0.1% accuracy) and of the RBS beam energy (at 0.06% accuracy). We demonstrate that accurate RBS is a definitive method to determine quantity of material. It is therefore useful for certifying high quality reference standards, and is also extensible to other kinds of samples such as thin self-supporting films of pure elements. The more powerful technique of Total-IBA may inherit the accuracy of RBS.

Value of the preservation of an osseous mandibular rim with a fibula free flap reconstruction.

BACKGROUND: Reconstruction of the mandible with microvascularized fibula transplants is actually a well-established procedure, yet the major component is the limited diameter of the diaphysis that can induce oral rehabilitation's failure, especially in dentate patients. In this paper, we report our surgical procedure allowing preservation of the mandibular height. The primary objective was to assess aesthetic and functional improvements of preservation of an osseous mandibular rim with a fibula free flap reconstruction. PATIENTS AND METHODS: Five patients (all males, mean age of 60 years) were treated with this method. Aetiologies were tumour in 3 cases, and osteoradionecrosis in the two others cases. We described all step of our surgical procedure and the functional, aesthetic and carcinologic results were evaluated. The follow up varies from 6 to 30 months. RESULTS: One patient died at 12 days from unrelated affection. For the other patients, both the aesthetics and functional outcomes were better than in case of mandibular interruption surgery. In fact, the mandibular contour of the mandibule was preserved and the height of mandible was restored. One patient is in progress of dental rehabilitation with osseous implants. Carcinologically, no local recurrence was observed. CONCLUSION: This technique is reliable and enables to optimize oral rehabilitation with endosteal implants. Nevertheless, we consider that the 3D scanner is essential before the intervention to evaluate the osseous reach. Moreover, if necessarily the procedure can be modified intraoperatively.

Synergistic Effect of He for the Fabrication of Ne and Ar Gas-Charged Silicon Thin Films as Solid Targets for Spectroscopic Studies.

Sputtering of silicon in a He magnetron discharge (MS) has been reported as a bottom-up procedure to obtain He-charged silicon films (i.e., He nanobubbles encapsulated in a silicon matrix). The incorporation of heavier noble gases is demonstrated in this work with a synergistic effect, producing increased Ne and Ar incorporations when using He-Ne and He-Ar gas mixtures in the MS process. Microstructural and chemical characterizations are reported using ion beam analysis (IBA) and scanning and transmission electron microscopies (SEM and TEM). In addition to gas incorporation, He promotes the formation of larger nanobubbles. In the case of Ne, high-resolution X-ray photoelectron and absorption spectroscopies (XPS and XAS) are reported, with remarkable dependence of the Ne 1s photoemission and the Ne K-edge absorption on the nanobubble's size and composition. The gas (He, Ne and Ar)-charged thin films are proposed as "solid" targets for the characterization of spectroscopic properties of noble gases in a confined state without the need for cryogenics or high-pressure anvils devices. Also, their use as targets for nuclear reaction studies is foreseen.

Psychosis and autism without functional regression in a patient with Kleefstra syndrome.

Kleefstra syndrome is a rare genetic disorder caused by haploinsufficiency of the euchromatic histone lysine methyltransferase 1 (EHMT1) gene. It is characterized by a variety of dysmorphic features, comorbid medical issues, and developmental delays/intellectual disability. Neuropsychiatric symptoms may also occur, including autistic features and psychosis, and are often accompanied by functional regression. However, the phenomenology of psychotic symptoms in this syndrome has not been well described in the literature. As such, in this brief report, we review the literature with respect to the occurrence of psychosis in Kleefstra syndrome and describe the symptom profile of a 35-year-old affected male with an intellectual disability, autism spectrum disorder, and schizophrenia (in association with manic features). This is the first report of psychotic symptoms fully remitting in response to zuclopenthixol therapy in an individual with Kleefstra syndrome. This case is also unique as it demonstrates that functional regression does not necessarily coincide with the development of schizophrenia-like presentations in affected individuals.

Improved Dual Network Model for Aging of Rubber Composites under Set Strains.

A new model is presented to predict rubber behavior during chemical aging at fixed strains. The model is validated using a carbon black-filled nitrile butadiene rubber aged in air at 125 °C. The model improves upon Tobolsky's dual network theory, designed for unfilled elastomers undergoing conventional aging but which has also often been used in rubber composites undergoing more complex aging scenarios. This work explores the shortcomings of the original model and demonstrates how the new model overcomes them. The model was validated using uniaxial tensile samples aged at 125 °C for 24-72 h at strains from 0-30%. The permanent set was measured, and the samples were tested on an Instron uniaxial test machine after aging. The cross-link density was estimated by equilibrium swelling. Results show that the new model more accurately models the stress-strain behavior to higher strains and provides more reliable estimates of chain scission and cross-linking after aging.

The Influence of Carbon Black Colloidal Properties on the Parameters of the Kraus Model.

The Payne Effect (also known as the Fletcher-Gent Effect) has a fundamental impact on the behavior of filled rubber composites and therefore must be considered during their design. This study investigates the influence of carbon black (CB) surface area and structure on the observed Payne Effect and builds on the existing models of Kraus and Ulmer to explain this phenomenon. Dynamic strain sweeps were carried out on natural rubber (NR) compounds containing eight different grades of CB at equivalent volume fractions. The loss and storage moduli were modeled according to the Kraus and Ulmer equations, using a curve optimization tool in SciPy. Subsequent regression analysis provided strong correlations between the fitting parameters and the CB structure and surface area. Using this regression analysis, this work provides further insight into the physical meaning behind the Kraus and Ulmer models, which are phenomenological in nature.

Influence of the solvent and the enantiomeric purity on the transition between different supramolecular polymers.

The self-assembly of two enantiomerically pure hexa(oligo(p-phenylene vinylene))-substituted benzenes having 24 stereocenters was studied in pure methylcyclohexane (MCH) and in a mixture of MCH/toluene (4:1). Irrespective of the solvent a cooperative supramolecular polymerization mechanism was determined for these star-shaped molecules by using temperature-dependent CD and UV/Vis spectroscopy. Quite remarkably, a transition from one helical supramolecular state (A) to a second more thermodynamically stable supramolecular helical assembly (B) was observed. The rate of the A→B transition was strongly dependent on the nature of the solvent; being faster in the solvent mixture than in pure MCH. By using size exclusion chromatography we could relate the increased rate to a decreased stability of the supramolecular A state in the solvent mixture. Next, we mixed the two enantiomerically pure hexa-substituted benzene derivatives in a so-called majority-rules experiment, which lead to the anitcipated chiral amplification in the A state. More importantly it appeared that the A→B transition was significantly hampered in these mixed systems. Furthermore, the absence of chiral amplification in the B state revealed the formation of separated enantiomerically pure assemblies. Therefore, by using a wide variety of spectroscopic and chromatographic techniques we determined the influence of solvent and enantiomeric purity on the transition between different supramolecular states.

Rustling ants: Vibrational communication performed by two Camponotus species in Borneo.

Interactions between ants and plants are classic examples of cooperation between individuals of different species. Usually, plants provide shelter or food for ants and in turn are defended against herbivores by their insect allies. To coordinate attacks, ants use multi-modal alarm signals consisting of vibrational and chemical components. This can also be observed in Borneo, where two Camponotus species inhabit the ocreas (diverging, tubular leaf sheaths) of the rattan palm Korthalsia robusta. When ants are disturbed, they beat or scratch mandibles and abdomens on the plant surface resulting in loud rustling sounds. To describe the characteristics of these signals, we recorded them with a Laser-Doppler-vibrometer in the field. Analyses of temporal patterns and dominant frequency revealed that the signals of the two species differ fundamentally. To assess transmission characteristics of the rattan palm, we conducted experiments under controlled lab-conditions. We show that the ocrea is an adequate structure for converting airborne sound into substrate vibrations, acting as a mediator between these two modalities. We hypothesize that the ants' vibratory signal has multiple functions, with the substrate-borne component used as an alarm signal for conspecifics, and the airborne component acting as vibro-acoustic aposematism against predators or herbivores to protect the host plant.

Low lamin A levels enhance confined cell migration and metastatic capacity in breast cancer.

Aberrations in nuclear size and shape are commonly used to identify cancerous tissue. However, it remains unclear whether the disturbed nuclear structure directly contributes to the cancer pathology or is merely a consequence of other events occurring during tumorigenesis. Here, we show that highly invasive and proliferative breast cancer cells frequently exhibit Akt-driven lower expression of the nuclear envelope proteins lamin A/C, leading to increased nuclear deformability that permits enhanced cell migration through confined environments that mimic interstitial spaces encountered during metastasis. Importantly, increasing lamin A/C expression in highly invasive breast cancer cells reflected gene expression changes characteristic of human breast tumors with higher LMNA expression, and specifically affected pathways related to cell-ECM interactions, cell metabolism, and PI3K/Akt signaling. Further supporting an important role of lamins in breast cancer metastasis, analysis of lamin levels in human breast tumors revealed a significant association between lower lamin A levels, Akt signaling, and decreased disease-free survival. These findings suggest that downregulation of lamin A/C in breast cancer cells may influence both cellular physical properties and biochemical signaling to promote metastatic progression.

Growth mechanisms involved in the synthesis of smooth and microtextured films by acetylene magnetron discharges.

The growth of hydrogenated amorphous carbons (a-C:H) produced by continuous or pulsed discharges of acetylene (C(2)H(2)) in an unbalanced magnetron setup was investigated. At 5 × 10(-3) Torr, only smooth films are obtained, whereas at 5 × 10(-1) Torr using a pulsed discharge some microtextured films are formed if the duty cycle is low. The morphology of these microtextured films consists of nanoparticles, filamentary particles, and particular agglomerates ("microflowers"). This paper presents a study of acetylene gas phase polymerization by mass spectrometry, and a detailed analysis of bulk structure of films by combining three techniques which include IR spectroscopy, Raman spectroscopy, and laser desorption/ionization Fourier transform mass spectrometry (LDI-FTMS). Finally, based on the study of gas phase and film structure, we propose a model for the growth of both smooth and microtextured films.

DNA methylation analysis reveals epimutation hotspots in patients with dilated cardiomyopathy-associated laminopathies.

BACKGROUND: Mutations in LMNA, encoding lamin A/C, lead to a variety of diseases known as laminopathies including dilated cardiomyopathy (DCM) and skeletal abnormalities. Though previous studies have investigated the dysregulation of gene expression in cells from patients with DCM, the role of epigenetic (gene regulatory) mechanisms, such as DNA methylation, has not been thoroughly investigated. Furthermore, the impact of family-specific LMNA mutations on DNA methylation is unknown. Here, we performed reduced representation bisulfite sequencing on ten pairs of fibroblasts and their induced pluripotent stem cell (iPSC) derivatives from two families with DCM due to distinct LMNA mutations, one of which also induces brachydactyly. RESULTS: Family-specific differentially methylated regions (DMRs) were identified by comparing the DNA methylation landscape of patient and control samples. Fibroblast DMRs were found to enrich for distal regulatory features and transcriptionally repressed chromatin and to associate with genes related to phenotypes found in tissues affected by laminopathies. These DMRs, in combination with transcriptome-wide expression data and lamina-associated domain (LAD) organization, revealed the presence of inter-family epimutation hotspots near differentially expressed genes, most of which were located outside LADs redistributed in LMNA-related DCM. Comparison of DMRs found in fibroblasts and iPSCs identified regions where epimutations were persistent across both cell types. Finally, a network of aberrantly methylated disease-associated genes revealed a potential molecular link between pathways involved in bone and heart development. CONCLUSIONS: Our results identified both shared and mutation-specific laminopathy epimutation landscapes that were consistent with lamin A/C mutation-mediated epigenetic aberrancies that arose in somatic and early developmental cell stages.

Very Low Vitamin D in a Patient With a Novel Pathogenic Variant in the GC Gene That Encodes Vitamin D-Binding Protein.

Circulating plasma vitamin D metabolites are highly bound to vitamin D-binding protein (DBP), also known as group-specific component or Gc-globulin. DBP, encoded by the GC gene, is a member of the albumin family of globular serum transport proteins. We previously described a homozygous GC gene deletion in a patient with apparent severe vitamin D deficiency, fragility fractures, and ankylosing spondylitis. Here, we report an unrelated patient free of fractures or rheumatologic disease, but with very low 25-hydroxyvitamin D and 1,25-hydroxyvitamin D, as well as undetectable DBP measured by liquid chromatography-tandem mass spectrometry. A whole gene deletion was excluded by microarray, and Sanger sequencing of GC revealed a homozygous pathogenic variant affecting a canonical splice site (c0.702-1G > A). These findings indicate that loss of function variants in GC that eliminate DBP, and severely reduced total circulating vitamin D levels, do not necessarily result in significant metabolic bone disease. Together with our previous report, these cases support the free-hormone hypothesis, and suggest free vitamin D metabolites may serve as preferable indicators of bone and mineral metabolism, particularly when clinical suspicion of DBP deficiency is high.