Lifestyle behaviour patterns in the prevention of type 2 diabetes mellitus: the Fukushima Health Database 2015-2020

OBJECTIVES

Lifestyle behaviours associated with the incidence of type 2 diabetes mellitus (T2DM) need further clarification using health insurance data.

STUDY DESIGN

This is a cohort study.

METHODS

In 2015, 193,246 participants aged 40-74 years attended the specific health checkups and were observed up to 2020 in Fukushima, Japan. Using the principal component analysis, we identified two patterns from ten lifestyle behaviour questions, namely, the "diet-smoking" pattern (including smoking, alcohol drinking, skipping breakfast, eating fast, late dinner, and snacking) and the "physical activity-sleep" pattern (including physical exercise, walking equivalent activity, walking fast, and sufficient sleep). Then, individual pattern scores were calculated; the higher the scores, the healthier the behaviours.

RESULTS

The accumulative incidence rate of T2DM was 630.5 in men and 391.9 in women per 100,000 person-years in an average of 4 years of follow-up. Adjusted for the demographic and cardiometabolic factors at the baseline, the hazard ratio (95% confidence interval) of the highest versus lowest quartile scores of the "diet-smoking" pattern for T2DM risk was 0.82 (0.72, 0.92; P for trend = 0.002) in men and 0.87 (0.76, 1·00; P for trend = 0.034) in women; that of the "physical activity-sleep" pattern was 0.92 (0.82, 1·04; P for trend = 0.0996) in men and 0.92 (0.80, 1·06; P for trend = 0.372) in women. The "physical activity-sleep" pattern showed a significant inverse association in non-overweight men.

CONCLUSIONS

Lifestyle behaviour associated with a healthy diet and lack of smoking may significantly lower the risk of T2DM in middle-aged Japanese adults.

Prevalence trends of metabolic syndrome in residents of postdisaster Fukushima: a longitudinal analysis of Fukushima Health Database 2012-2019

OBJECTIVES

The study aimed to evaluate the long-term metabolic risk profiles of Fukushima residents after the Great East Japan Earthquake of March 2011.

STUDY DESIGN

This was a cross-sectional and a longitudinal design.

METHODS

The Fukushima Health Database (FDB) contains 2,331,319 annual health checkup records of participants aged 40-74 years between 2012 and 2019. We checked the validity of the FDB by comparing the prevalence of metabolic factors with the National Database of Health Insurance Claims and Specific Health Checkups (NDB). We applied a regression analysis to determine the changes and project the trends of metabolic factors over the years.

RESULTS

Compared to the NDB, the prevalence of metabolic factors in Fukushima was higher than the country average from 2013 to 2018, and they showed the same trends as those from the FDB. The prevalence of metabolic syndrome (MetS) increased from 18.9% in 2012 to 21.4% in 2019 (an annual increase of 2.74%) in men and from 6.8 to 7.4% (an annual increase of 1.80%) in women in Fukushima. The standardized prevalence of MetS, being overweight, and diabetes is projected to continue increasing, with disparities among subareas being higher in evacuees than in non-evacuees. An annual decrease of 0.38-1.97% in hypertension was mainly observed in women.

CONCLUSIONS

The prevalence of metabolic risk is higher in Fukushima as compared to the country average. The increasing metabolic risk in subareas, including the evacuation zone, highlights the need to control MetS in Fukushima residents.

Development of a cost-effective automated platform to produce human liver spheroids for basic and applied research

Liver disease represents an increasing cause of global morbidity and mortality. Currently, liver transplant is the only treatment curative for end-stage liver disease. Donor organs cannot meet the demand and therefore scalable treatments and new disease models are required to improve clinical intervention. Pluripotent stem cells represent a renewable source of human tissue. Recent advances in three-dimensional cell culture have provided the field with more complex systems that better mimic liver physiology and function. Despite these improvements, current cell-based models are variable in performance and expensive to manufacture at scale. This is due, in part, to the use of poorly defined or cross-species materials within the process, severely affecting technology translation. To address this issue, we have developed an automated and economical platform to produce liver tissue at scale for modelling disease and small molecule screening. Stem cell derived liver spheres were formed by combining hepatic progenitors with endothelial cells and stellate cells, in the ratios found within the liver. The resulting tissue permitted the study of human liver biology 'in the dish' and could be scaled for screening. In summary, we have developed an automated differentiation system that permits reliable self-assembly of human liver tissue for biomedical application. Going forward we believe that this technology will not only serve as anin vitroresource, and may have an important role to play in supporting failing liver function in humans.

Abstract P5-09-12: Germline mutation in TP53 gene in a cohort of 2,561 Chinese high-risk breast cancer patients using multigene panel testing

Background: Li-Fraumeni syndrome (LFS) is a rare autosomal genetic disorder with germline TP53 mutations. Patients with TP53 mutations have a higher risk of developing breast cancer than those harboring BRCA mutations. Although limited studies have shown that TP53 mutation carriers are less responsive to low dose radiation and more susceptible to induce new malignancies from radiotherapy. Moreover screening strategies allows early detection of a spectrum of cancers related to TP53 mutations. From work of BRCA mutations where over 40% novel mutations were detected in Chinese cohort, it is important to evaluate the frequency of TP53 mutation in Chinese to better understand the spectrum to guide appropriate clinical management of these high risk individuals.

Methods: TP53 gene mutation screening was performed on 2,561 high-risk breast cancer patients using multigene panel testing. The patients were accrued by Hong Kong Hereditary and High Risk Breast Cancer Program from March 2007 to May 2018. All detected pathogenic mutations were further validated by bi-directional DNA sequencing and analyzed by our in-house developed bioinformatics pipeline.

Results: Sixteen distinct pathogenic or likely pathogenic variants were identified, and 3 of them were de novo TP53 mutations (18.75%). The mean age of patients who harbored TP53 mutation was 30.44 years (range 18-44), and 50% of the tumors were bilateral breast cancer. Of sixteen different pathogenic mutations, majority of them were missense mutation (87.5%), and 2 were nonsense mutation (12.5%). Four of the sixteen TP53 mutation carriers had family history of breast cancer, while others had a family history of lung cancer (43.75%).

Conclusion: This study revealed that seven patients were found to habor TP53 mutation even when they did not meet the criteria of LFS of LFS-like phenotype, implicated the importance of using multigene panel test for probands and their relatives to offer a comprehensive surveillance programe for TP53 carriers.

Citation Format: Kwong A, Shin V, Au CH, Ho C, Slavin T, Weitzel J, Chan TL, Ma E. Germline mutation in TP53 gene in a cohort of 2,561 Chinese high-risk breast cancer patients using multigene panel testing [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-12.

Structural Parameter of Orientational Order to Predict the Boson Vibrational Anomaly in Glasses

It has so far remained a major challenge to quantitatively predict the boson peak, a THz vibrational anomaly universal for glasses, from features in the amorphous structure. Using molecular dynamics simulations of a model Cu_{50}Zr_{50} glass, we decompose the boson peak to contributions from atoms residing in different types of Voronoi polyhedra. We then introduce a microscopic structural parameter to depict the "orientational order," using the vector pointing from the center atom to the farthest vertex of its Voronoi coordination polyhedron. This order parameter represents the most probable direction of transverse vibration at low frequencies. Its magnitude scales linearly with the boson peak intensity, and its spatial distribution accounts for the quasilocalized modes. This correlation is shown to be universal for different types of glasses.

Universal intracellular biomolecule delivery with precise dosage control

Intracellular delivery of mRNA, DNA, and other large macromolecules into cells plays an essential role in an array of biological research and clinical therapies. However, current methods yield a wide variation in the amount of material delivered, as well as limitations on the cell types and cargoes possible. Here, we demonstrate quantitatively controlled delivery into a range of primary cells and cell lines with a tight dosage distribution using a nanostraw-electroporation system (NES). In NES, cells are cultured onto track-etched membranes with protruding nanostraws that connect to the fluidic environment beneath the membrane. The tight cell-nanostraw interface focuses applied electric fields to the cell membrane, enabling low-voltage and nondamaging local poration of the cell membrane. Concurrently, the field electrophoretically injects biomolecular cargoes through the nanostraws and into the cell at the same location. We show that the amount of material delivered is precisely controlled by the applied voltage, delivery duration, and reagent concentration. NES is highly effective even for primary cell types or different cell densities, is largely cargo agnostic, and can simultaneously deliver specific ratios of different molecules. Using a simple cell culture well format, the NES delivers into >100,000 cells within 20 s with >95% cell viability, enabling facile, dosage-controlled intracellular delivery for a wide variety of biological applications.

Melt fluxing to elevate the forming ability of Al-based bulk metallic glasses

Salt-fluxing treatment is an effective technique to improve the glass-forming ability (GFA) of bulk metallic glass (BMG)-forming melts, as demonstrated before in Pd- and Fe-based systems. However, it has been challenging to develop similar fluxing protocol for more reactive melts, such as Al-rich BMG-forming systems. Here we design new fluxing agents, from a thermodynamics perspective that takes into account combined effects of physical absorption and chemical absorption (reaction) between the fluxing agents and oxide inclusions. MgCl₂-CaCl₂ composite salts were selected, and their fluxing effects were systematically studied on an Al₈₆Ni_6.75Co_2.25Y_3.25La_1.75 alloy, the best BMG-forming composition reported thus far for Al-rich alloy systems. The oxygen content was found to continuously decrease in the master alloy with increasing cycles of salt-fluxing treatment, with chlorate products on the surface suggesting concurrent physical absorption and chemical reaction. The fluxing treatment developed has enabled a record critical size (diameter) of 2.5 mm for Al-based BMGs. Our finding is thus an advance in developing highly desirable Al-based BMGs, and also provides guidance for designing processing protocol to produce larger-sized BMGs in other reactive systems.

Nanostructured high-strength molybdenum alloys with unprecedented tensile ductility

The high-temperature stability and mechanical properties of refractory molybdenum alloys are highly desirable for a wide range of critical applications. However, a long-standing problem for these alloys is that they suffer from low ductility and limited formability. Here we report a nanostructuring strategy that achieves Mo alloys with yield strength over 800 MPa and tensile elongation as large as ~ 40% at room temperature. The processing route involves a molecular-level liquid-liquid mixing/doping technique that leads to an optimal microstructure of submicrometre grains with nanometric oxide particles uniformly distributed in the grain interior. Our approach can be readily adapted to large-scale industrial production of ductile Mo alloys that can be extensively processed and shaped at low temperatures. The architecture engineered into such multicomponent alloys offers a general pathway for manufacturing dispersion-strengthened materials with both high strength and ductility.

Microstructural fingerprints of phase transitions in shock-loaded iron

The complex structural transformation in crystals under static pressure or shock loading has been a subject of long-standing interest to materials scientists and physicists. The polymorphic transformation is of particular importance for iron (Fe), due to its technological and sociological significance in the development of human civilization, as well as its prominent presence in the earth's core. The martensitic transformation α→ε (bcc→hcp) in iron under shock-loading, due to its reversible and transient nature, requires non-trivial detective work to uncover its occurrence. Here we reveal refined microstructural fingerprints, needle-like colonies and three sets of {112}<111> twins with a threefold symmetry, with tell-tale features that are indicative of two sequential martensitic transformations in the reversible α→ε phase transition, even though no ε is retained in the post-shock samples. The signature orientation relationships are consistent with previously-proposed transformation mechanisms, and the unique microstructural fingerprints enable a quantitative assessment of the volume fraction transformed.

Pressure tunes electrical resistivity by four orders of magnitude in amorphous Ge2Sb2Te5 phase-change memory alloy

Ge-Sb-Te-based phase-change memory is one of the most promising candidates to succeed the current flash memories. The application of phase-change materials for data storage and memory devices takes advantage of the fast phase transition (on the order of nanoseconds) and the large property contrasts (e.g., several orders of magnitude difference in electrical resistivity) between the amorphous and the crystalline states. Despite the importance of Ge-Sb-Te alloys and the intense research they have received, the possible phases in the temperature-pressure diagram, as well as the corresponding structure-property correlations, remain to be systematically explored. In this study, by subjecting the amorphous Ge(2)Sb(2)Te(5) (a-GST) to hydrostatic-like pressure (P), the thermodynamic variable alternative to temperature, we are able to tune its electrical resistivity by several orders of magnitude, similar to the resistivity contrast corresponding to the usually investigated amorphous-to-crystalline (a-GST to rock-salt GST) transition used in current phase-change memories. In particular, the electrical resistivity drops precipitously in the P = 0 to 8 GPa regime. A prominent structural signature representing the underlying evolution in atomic arrangements and bonding in this pressure regime, as revealed by the ab initio molecular dynamics simulations, is the reduction of low-electron-density regions, which contributes to the narrowing of band gap and delocalization of trapped electrons. At P > 8 GPa, we have observed major changes of the average local structures (bond angle and coordination numbers), gradually transforming the a-GST into a high-density, metallic-like state. This high-pressure glass is characterized by local motifs that bear similarities to the body-centered-cubic GST (bcc-GST) it eventually crystallizes into at 28 GPa, and hence represents a bcc-type polyamorph of a-GST.

The design of long-term effective uranium bioremediation strategy using a community metabolic model

Acetate amendment at uranium contaminated sites in Rifle, CO. leads to an initial bloom of Geobacter accompanied by the removal of U(VI) from the groundwater, followed by an increase of sulfate-reducing bacteria (SRBs) which are poor reducers of U(VI). One of the challenges associated with bioremediation is the decay in Geobacter abundance, which has been attributed to the depletion of bio-accessible Fe(III), motivating the investigation of simultaneous amendments of acetate and Fe(III) as an alternative bioremediation strategy. In order to understand the community metabolism of Geobacter and SRBs during artificial substrate amendment, we have created a genome-scale dynamic community model of Geobacter and SRBs using the previously described Dynamic Multi-species Metabolic Modeling framework. Optimization techniques are used to determine the optimal acetate and Fe(III) addition profile. Field-scale simulation of acetate addition accurately predicted the in situ data. The simulations suggest that batch amendment of Fe(III) along with continuous acetate addition is insufficient to promote long-term bioremediation, while continuous amendment of Fe(III) along with continuous acetate addition is sufficient to promote long-term bioremediation. By computationally minimizing the acetate and Fe(III) addition rates as well as the difference between the predicted and target uranium concentration, we showed that it is possible to maintain the uranium concentration below the environmental safety standard while minimizing the cost of chemical additions. These simulations show that simultaneous addition of acetate and Fe(III) has the potential to be an effective uranium bioremediation strategy. They also show that computational modeling of microbial community is an important tool to design effective strategies for practical applications in environmental biotechnology.

Interfacial Reactions of Mo with Al: Ion mixing Versus Thermal Annealing

Interfacial reactions induced by ion beam mixing and furnace annealing in Al/Mo bilayers are investigated. The amount of interfacial ion m'xing, 4Dt, follows a linear dose dependence for irradiation temperatures ≤80 C. Below room temperature, the mixing efficiency, defined as d(4Dt)/dø, is temperature independent, and agrees fairly well with the prediction of the phenomenological model based on chemically biased diffusion in thermal spike. We conclude that thermal spike mixing dominates for Xe irradiation of Al/Mo at low temperatures. The mixing efficiency becomes temperature-dependent above room temperature with an apparent activation enthalpy of about 0.17±0.02eV. A layer of 15–20 at.% Mo forms by ion mixing, while oAl12 Mo forms upon thermal annealing in a nonuniform fashion starting at 500°C. Reaction of Mo with large-grained Al substrates shows the same nonuniform characteristics as in evaporated Al/Mo bilayers, implying a minor role of grain boundary effects. Oxygen gettered in the Mo film could be an important factor that influences the interfacial reaction.

New structural picture of the Ge2Sb2Te5 phase-change alloy

Using electron microscopy and diffraction techniques, as well as first-principles calculations, we demonstrate that as much as 35% of the total Ge atoms in the cubic phase of Ge2Sb2Te5 locate in tetrahedral environments. The Ge-vacancy interactions play a crucial stabilizing role, leading to Ge-vacancy pairs and the sharing of vacancies that clusters tetrahedral Ge into domains. The Ge2Sb2Te5 structure with coexisting octahedral and tetrahedral Ge produces optical and structural properties in good agreement with experimental data and explains the property contrast as well as the rapid transformation in this phase-change alloy.

Role of miR-143 Regulating DNA Methyltransferases 3A in Breast Cancer

Background and Aims: MicroRNAs (miRNAs) are 19-25-nucleotides regulatory non-protein-coding RNA molecules that regulate the expressions of a wide variety of genes including some involved in cancer development. In particular, decreased expression of miR-143 has been reported in various human cancers including colorectal cancer and B-cell lymphomas. The aim of this study was to elucidate the role of miR-143 dysregulation in breast cancer.Methods: Expression levels of human mature microRNAs (miRNAs) were compared with paired breast carcinomas and adjacent normal tissues by TaqMan real-time PCR based expression arrays. Decreased expression of miR-143 was further confirmed in breast cancer cell lines and paired breast tumors and normal adjacent tissues by qRT-PCR. Potential targets of miR-143 were defined. The functional effect of miR-143 and its targets was performed in human breast cancer cell lines to confirm target association.Results: Down-regulation of miR-143 was verified in both human breast cancer cell lines and 80% (12/15) of breast tumors (P &lt; 0.001). DNA methyltranferase 3A (DNMT3A), one of a key enzyme involved in DNA methylation, was defined as a potential target of miR-143 by in-silico analysis. Overexpression of miR-143 in breast cancer cell lines down-regulated expression of DNMT3A, decreased tumor cell growth by MTT assay and soft agar colony formation assay. DNMT3A was demonstrated to be a direct target of miR-143 by luciferase reporter assay. Inverse correlation between DNMT3A protein and miR-143 was found in tumor and normal breast tissues.Conclusions: In this study, we show for the first time in breast cancer that miR-143 specifically targeted DNMT3A and the expression of miR-143 was inversely correlated with DNMT3A expression. Our findings demonstrated that down-regulation of miR-143 and up-regulation of DNMT3A are significant changes in breast tumors. These findings indicate a tumor suppressive role of miR-143 in epigenetic aberration of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3148.

Nature of atomic bonding and atomic structure in the phase-change Ge2Sb2Te5 glass

Using electronic structure calculations, we demonstrate a global valence alternation in the amorphous Ge2Sb2Te5, a prototype phase-change alloy for data storage. The resulting p bonding profoundly influences the local atomic structure, leading to right-angle components similar to those in the crystalline counterpart of this chalcogenide glass. The dominance of p bonding is revealed by (i) distributions of the coordination number (CN) and the bond angle, for truly bonded atoms determined based on the electron localization function, and (ii) a direct evaluation of the p (and s) orbital occupation probability for the CN=3 Ge atoms that form 90 degree bonds with neighbors.

Atomic shuffling dominated mechanism for deformation twinning in magnesium

Deformation twinning is often mediated by partial dislocation activities at the twin boundary. Using molecular dynamics simulations, we have uncovered a new mechanism for the most commonly observed {1012}<101 1> deformation twinning in Mg and other hexagonal close-packed metals. Here the twin growth involves no definable dislocations at the twin boundary, and the twin orientational relationship can be established by local atomic shuffling, directly constructing the twin lattice from the parent lattice.

Atomic level structure in multicomponent bulk metallic glass

The atomic-level structure of a representative ternary Cu-Zr-Al bulk metallic glass (BMG) has been resolved. Cu- (and Al-) centered icosahedral clusters are identified as the basic local structural motifs. Compared with the Cu-Zr base binary, a small percentage of Al in the ternary BMG leads to dramatically increased population of full icosahedra and their spatial connectivity. The stabilizing effect of Al is not merely topological, but also has its origin in the electronic interactions and bond shortening.

Reversible twinning in pure aluminum

Twinning in metals is normally a permanent plastic deformation mechanism. Here we report reversible twinning in high stacking fault energy (SFE) aluminum. Twinning and spontaneous detwinning at the crack tip have been captured in situ during tensile straining under a transmission electron microscope. Both the in situ observation and the molecular dynamics simulations reveal a two-stage detwinning process. The high propensity for detwinning is due to the high SFE and the low frictional forces against the detwinning partial dislocations in Al. This discovery of reversible twinning has implications for the deformation of other high SFE materials.

Novel de novo BRCA1 mutation in a woman with early onset breast cancer

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Background: Germline mutations in BRCA1/2 account for a significant portion of hereditary breast/ovarian cancer. Mutation carriers usually have a family history of breast/ovarian cancer or early onset disease. Rarely, germline mutations are found only in the probands but not in any family members. Such de novo mutations have been reported in diseases such as hemophilia A, thalassaemia and familial adenomatous polyposis. De novo mutations in the BRCA1 or BRCA2 genes are rare and the few reported have been in BRCA2. Here, we describe de novo as well as novel mutation of the BRCA1 gene in a breast cancer patient. Methods: Blood DNA samples from a 30 year old Chinese woman with breast cancer and no family history of cancer was tested for a BRCA1/2 mutation by full gene sequencing and Multiple Ligation-dependent Probe Amplification (MLPA). Family members were analyzed for the same mutation. Paternity was determined by a set of highly polymorphic short tandem repeat (STR) markers. Results: Full gene sequencing found no deleterious mutation. MLPA revealed a large deletion of exons 1 to 12 of BRCA1 in the proband. MLPA performed on 5 family members: proband's mother and father (who were 1st degree relative- cousins), stepmother (mother's biological sister), 2 sisters (1, same parents; 1, same father and stepmother) found no similar deletion. By using a set of highly polymorphic STR markers, the proband's father and mother were confirmed to be her biological parents. Conclusions: We report a novel de novo BRCA1 deletion mutation encompassing exons 1 - 12 in a Chinese breast cancer patient of early onset with no family history. Identification of this large deletion confirms the importance of pursuing rearrangement testing if full gene sequencing fails to detect a point mutation or short insertion deletion. The mutation found in this study is de novo. This may simply be a random mutation event which occurred in the parents' germ cells during their lifetime which passed onto one of their offspring or maybe a result of gene inversion or splicing deficiency. The relations of such mutations with consanguineous marriage cannot be ruled out. Mutation screening is important in early onset breast cancer patients even if there is no family history.

No significant financial relationships to disclose.

Tensile ductility and necking of metallic glass

Metallic glasses have a very high strength, hardness and elastic limit. However, they rarely show tensile ductility at room temperature and are considered quasi-brittle materials. Although these amorphous metals are capable of shear flow, severe plastic instability sets in at the onset of plastic deformation, which seems to be exclusively localized in extremely narrow shear bands approximately 10 nm in thickness. Using in situ tensile tests in a transmission electron microscope, we demonstrate radically different deformation behaviour for monolithic metallic-glass samples with dimensions of the order of 100 nm. Large tensile ductility in the range of 23-45% was observed, including significant uniform elongation and extensive necking or stable growth of the shear offset. This large plasticity in small-volume metallic-glass samples did not result from the branching/deflection of shear bands or nanocrystallization. These observations suggest that metallic glasses can plastically deform in a manner similar to their crystalline counterparts, via homogeneous and inhomogeneous flow without catastrophic failure. The sample-size effect discovered has implications for the application of metallic glasses in thin films and micro-devices, as well as for understanding the fundamental mechanical response of amorphous metals.

Characterization of the pathogenic mechanism of a novel BRCA2 variant in a Chinese family

10541

Background: Despite the identification of a large number of sequences in BRCA1/2 mutation analyses, many genetic alterations are classified as variants of unknown significance (VUS). Increasing data demonstrates ethnic variation of BRCA mutation. We report a novel BRCA2 VUS in a Chinese family with multiple breast cancers and characterized it as pathogenic by RNA analysis. Method: Peripheral blood was collected from the breast cancer proband and her family who were suspected to have a pathogenic mutation due the segregation of the disease phenotype and the young age of presentation of breast cancer. DNA and RNA was extracted from the blood. The entire coding regions and flanking introns of BRCA1/2 were screened for germline mutations using full gene sequencing and Multiplex Ligation -dependent Probe Amplification. Variant DNA alteration leading to an aberrant BRCA transcript was demonstrated by RT-PCR of the RNA and Polyacrylamide Gel Electrophoresis. Abnormal bands were cloned and direct sequencing conducted. Results: A germline mutation c.7806–9T>G was identified in the proband at the BRCA2 intron 16. This mutation was also found in 3 of her 4 sibling sisters with early breast cancer. The proband's mother harbored the same BRCA2 mutation in DNA extracted from archival gastric tumor tissues. Computational analyses showed that this mutation might give rise to a cryptic splice site for alternative RNA splicing. To confirm the pathogenicity, RT- PCR using specific primers flanking the cryptic splice site and sequencing was performed on RNA extracted from the proband's blood. Four different sizes of transcripts were found: wild type, r.7806_7874del , r.7806_7976del and r.7806–8_7806-lins. The latter 3 aberrant transcripts were not found in the 30 controls therefore polymorphism is unlikely. The r.7806–8_7806-lins transcript caused a frameshift which created a truncated protein; whereas the other two short transcripts produced shorter BRCA2 protein isoforms. Conclusion: We identified a novel BRCA2 VUS and classified it as pathogenic. Classification of VUS as neutral or pathogenic, particularly in ethnic groups where limited knowledge is known is a challenge. Research on the spectrum of mutations in diversed ethnic groups has important implications on management. [Genbank: DQ889340 ]

No significant financial relationships to disclose.

Polyamorphism in a metallic glass

A metal, or an alloy, can often exist in more than one crystal structure. The face-centred-cubic and body-centred-cubic forms of iron (or steel) are a familiar example of such polymorphism. When metallic materials are made in the amorphous form, is a parallel 'polyamorphism' possible? So far, polyamorphic phase transitions in the glassy state have been observed only in glasses involving directional and open (such as tetrahedral) coordination environments. Here, we report an in situ X-ray diffraction observation of a pressure-induced transition between two distinct amorphous polymorphs in a Ce(55)Al(45) metallic glass. The large density difference observed between the two polyamorphs is attributed to their different electronic and atomic structures, in particular the bond shortening revealed by ab initio modelling of the effects of f-electron delocalization. This discovery offers a new perspective of the amorphous state of metals, and has implications for understanding the structure, evolution and properties of metallic glasses and related liquids. Our work also opens a new avenue towards technologically useful amorphous alloys that are compositionally identical but with different thermodynamic, functional and rheological properties due to different bonding and structural characteristics.

Spectrum of EGFR mutations associated with non-small cell lung cancer in an Asian Chinese population

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Background: Somatic mutations in tyrosine kinase (TK) domain of the EGFR gene, predicting for sensitivity to TK inhibition therapy, are over-represented in lung cancer with adenocarcinoma or bronchioloalveolar histology, non-smokers, female gender and East Asian ethnicity. Methods: We prospectively screened for EGFR mutations at exons 19–21 on micro-dissected specimen enriched for tumor cells by direct nucleotide sequencing in Hong Kong Chinese patients. Results: From May 2005 onwards, a total of 27 patients were analyzed. They comprised 11 males and 16 females with a median age of 67 years. Histological diagnoses were adenocarcinoma (n = 22), bronchioloalveolar carcinoma (n = 4) and squamous cell carcinoma (n = 1). Samples included primary tumor (n = 20) as well as metastatic lesions (n = 7). EGFR mutations were detected in 17 patients (63%), the most common being L858R at exon 21 (n = 7) followed by exon 19 deletions (del(746–750) = 3, del(747–751) = 1, del(747–753) = 3) and G719C at exon 18 (n = 1). Two patients showed novel EGFR mutations, namely 4-base pair insertion deletion at exon 19 leading to substitution of Glu746-Leu747 by Val746-Pro747 and three base pair deletion at exon 18 leading to replacement of Glu709-Thr710 by Asp. Furthermore, two patients showed double mutations, including novel S768I at exon 20 in combination with G719C, and novel K860I at exon 21 in combination with L858R. Finally, one patient showed homozygous del(747–753) as detected by sequencing in both primary lung tumor and brain secondary, which might represent loss of heterozygosity. Conclusions: Similar to other series, two hotspots i.e. exon 19 deletion and L858 account for the majority (82%) of detectable EGFR mutations in our patient population. For the rare and novel variants, it would be of interest to document the clinical responsiveness to TK inhibitors gefitinib and erlotinib, so that a more complete picture of cancer genotype phenotype correlation can be achieved.

No significant financial relationships to disclose.

Atomic packing and short-to-medium-range order in metallic glasses

Unlike the well-defined long-range order that characterizes crystalline metals, the atomic arrangements in amorphous alloys remain mysterious at present. Despite intense research activity on metallic glasses and relentless pursuit of their structural description, the details of how the atoms are packed in amorphous metals are generally far less understood than for the case of network-forming glasses. Here we use a combination of state-of-the-art experimental and computational techniques to resolve the atomic-level structure of amorphous alloys. By analysing a range of model binary systems that involve different chemistry and atomic size ratios, we elucidate the different types of short-range order as well as the nature of the medium-range order. Our findings provide a reality check for the atomic structural models proposed over the years, and have implications for understanding the nature, forming ability and properties of metallic glasses.

Use of midazolam and ketamine as sedation for children undergoing minor operative procedures

OBJECTIVES

We used intravenous midazolam and ketamine for children undergoing minor operative procedures with satisfactory results. We aimed to further evaluate its efficacy and adverse effects in pediatric ward setting.

METHODS

This was a prospective study of all children undergoing minor operations with sedation in our pediatric general and oncology wards from July 1998 to June 1999. The procedures included lumber puncture+/-intrathecal chemotherapy, bone marrow aspiration+/-trephine biopsy, central venous catheter removal, skin biopsy, or their combination. All sedation procedures were started with midazolam 0.1 mg/kg and ketamine 1 mg/kg; they were increased gradually to 0.4 and 4 mg/kg, respectively, if necessary. Heart rate and SaO2 were continuously monitored.

RESULTS

Altogether, 369 minor operations were performed in 112 patients (male:female=2:1, median age 6 years, range 5 months-17 years). All achieved adequate sedation, with 96% within 30 s and 75% required just the starting dose. Younger children required a higher dosage (p=0.003 for midazolam, p<0.001 for ketamine). The median recovery time was 87 min, with no association with age, sex, or dosage of sedation, but was longer in patients having hallucination (p=0.001). Adverse effects included tachycardia (27.9%), increased secretion (17.6%), agitation (13.6%), nausea and vomiting (9.2%), hallucination (8.7%), desaturation (8.4%), and cataleptic reaction (0.8%). All desaturation episodes were transient and responded to oxygen supplement alone. None developed bronchospasm or convulsion. Some adverse effects were dose-related. Half of the children who received 0.3 mg/kg midazolam developed desaturation.

CONCLUSIONS

Intravenous midazolam-ketamine can provide rapid, effective, and safe sedation for children undergoing minor operations in ward setting. Adverse effects are mild. Midazolam above 0.3 mg/kg should be used with caution.

Male and female prolactin receptor mRNA expression in the brain of a biparental and a uniparental hamster, phodopus, before and after the birth of a litter

Prolactin receptor (PRL-R) mRNA transcript level was quantified in the choroid plexus (ChP) of a naturally biparental hamster, Phodopus campbelli, and its otherwise similar, yet nonpaternal, sibling species, Phodopus sungorus. Pair-housed males and females on the day before the birth of their first litter (G17), the day after birth (L1), lactation day 5 (L5), and unpaired animals that were sexually naïve, were tested. PRL-R mRNA transcript level relative to total RNA, was evaluated by reverse transcriptase-polymerase chain reaction using primers common to the long- and short-form of the PRL-R in Phodopus. In the ChP, a region implicated in prolactin transport into the central nervous system, females had the expected increase in PRL-R mRNA transcript from dioestrus to L5, consistent with known actions of prolactin. As predicted, males and females of the biparental species were similar, although PRL-R mRNA in naive males was higher than in dioestrus females. Males of the two species also differed as predicted. PRL-R mRNA transcript levels were higher in the biparental males. In addition, P. campbelli males had low PRL-R mRNA at G17 compared to L5. By contrast, non-paternal P. sungorus males had elevated PRL-R mRNA transcript levels on G17 relative to unpaired males. We conclude that PRL-R mRNA in the ChP is differentially regulated before and after birth in a paternal and a nonpaternal male.

Atomic packing of the inherent structure of simple liquids

We report a universal inherent packing structure underlying the simple liquids, the normalized distribution functions of which are independent of temperature and density. The inherent packing state, carrying the maximized configurational entropy, has intrinsic connections with the maximally random jammed state of hard spheres.

Icosahedral short-range order in amorphous alloys

We have characterized the icosahedral short-range order in amorphous solids using local environment probes. Such topological local order is pronounced even in an amorphous alloy that does not form quasicrystalline phases upon crystallization, as demonstrated by the extended x-ray absorption fine structure and x-ray absorption near-edge structure of a Ni-Ag amorphous alloy analyzed through reverse Monte Carlo simulations.

Nanostructured Ti-based multi-component alloys with potential for biomedical applications

A group of Ti(60)Cu(14)Ni(12)Sn(4)M(10) (M=Nb, Ta, Mo) alloys was prepared using arc melting and copper mold casting. The as-prepared alloys have a composite microstructure containing a micrometer-sized dendritic beta-Ti(M) phase dispersed in a nanocrystalline matrix. These new alloys exhibit a low Young's modulus in the range of 59-103 GPa, and a high yield strength of 1037-1755 MPa, together with large plastic strains. The combination of high strength and low elastic modulus offers potential advantages in biomedical applications.

Evaluation of paediatric osteosarcomas by classic cytogenetic and CGH analyses

Classic cytogenetic and comparative genomic hybridisation (CGH) data on osteosarcomas have been reported extensively in the literature. However, the number of paediatric osteosarcoma cases studied below the age of 14 years remains relatively small. This study reports four new cases of paediatric osteosarcoma in patients aged 3 to 13 years, evaluated by classic cytogenetics and CGH analyses. Clonal chromosomal alterations were detected in all the cases and included structural rearrangements at 1p11-13, 1q11, 4q27-33, 6p23-25, 6q16-25, 7p13-22, 7q11-36, 11p10-15, 11q23, 17p11.2-13, 21p11, and 21q11-22. The CGH analysis revealed recurrent gains at 1p, 4q, 17p, and 21q and losses at 3q and 16p. Five amplification sites were observed at 1q11-23, 6p21, 8q13, 8q21.3-24.2, and 17p. The data are discussed and compared with other cytogenetic reports in the literature.

Homogeneity of a supersaturated solid solution

Extended x-ray absorption fine structures, small-angle x-ray scattering, and atomistic model calculations have been employed to probe the homogeneity of the fcc solution created in Ag-Cu, a classical system demonstrating the extension of solubility across the entire miscibility gap through rapid quenching. Our results reveal that in many cases the supersaturated solutions formed have decomposition features on the scale of 1 nm. Conventional diffraction methods are inadequate in determining the level of supersaturation or the uniformity of such solid solution alloys.

Neuronal tolerance to O2 deprivation in drosophila: novel approaches using genetic models

In spite of many advances in monitoring oxygenation and preventing cerebro-vascular accidents, there is still considerable morbidity and mortality from conditions with cerebral blood flow impairment and O2 deprivation leading to hypoxic/ischemic brain injury. Part of this failure is related to the complexity of the cascade of events that ensue after hypoxia or ischemia, but also part of it may be related to the fact that most research in the previous few decades has focused, justifiably, on cerebral vessel disease. However, an important aspect of the cascade is dependent on many factors that are inherent to the nature and response of the tissue itself. Hence, there is more need now for a two-pronged approach to hypoxic/ischemic brain injury, one focusing on vessel disease, its prevention, and treatment, and the other centering on the brain tissue itself and the factors that render neurons and glia more susceptible or more tolerant to a lack of oxygenation. In the past several years, a number of methods, techniques, and animal models have been used to address the response of neurons and glia to lack of oxygen. In this review, we highlight some novel ideas and some results that we and others have obtained, mostly pertaining to the genetic endowment and responses of the central nervous system to O2 deprivation. The role and importance of genetic models, such as the Drosophila melanogaster, are discussed, and an example illustrating how to harness the power of Drosophila genetics is detailed.

Familial deletion of (8)(q24.13q24.22) associated with a normal phenotype

We report a familial deletion of (8q) detected in amniocytes of a fetus with a normal ultrasound and in the phenotypically normal mother, who has now had three pregnancy losses. Chromosome analysis of amniocytes and maternal peripheral blood cells showed an interstitial deletion of (8)(q24.13q24.22), which is distal to the region associated with Langer-Giedion syndrome (LGS) or trichorhinophalangeal (TRP) syndrome. This deletion was confirmed by fluorescence in situ hybridization with a c-myc cosmid clone and chromosome 8 painting library.

Melting mechanisms at the limit of superheating

The atomic-scale details during melting of a surface-free Lennard-Jones crystal were monitored using molecular dynamics simulations. Melting occurs when the superheated crystal spontaneously generates a sufficiently large number of spatially correlated destabilized particles that simultaneously satisfy the Lindemann and Born instability criteria. The accumulation and coalescence of these internal local lattice instabilities constitute the primary mechanism for homogeneous melt nucleation inside the crystal, in lieu of surface nucleation for equilibrium melting. The vibrational and elastic lattice instability criteria as well as the homogeneous nucleation theory all coincide in determining the superheating limit.

Neutrino mass, muon anomalous magnetic moment, and lepton flavor nonconservation

If the generating mechanism for neutrino mass is to account for both the newly observed muon anomalous magnetic moment as well as the present experimental bounds on lepton flavor nonconservation, then the neutrino mass matrix should be almost degenerate and the underlying physics should be observable at future colliders. We illustrate this assertion with two specific examples, and show that gamma(mu;-->egamma)/m5(mu), gamma(tau-->egamma)/m5tau, and gamma(tau-->(mu)gamma)/m5tau are in the ratio ((Delta)m2)2sol/2, ((Delta)m2)2sol/2, and ((Delta)m2)2atm, respectively, where the (Delta)m2 parameters are those of solar and atmospheric neutrino oscillations and bimaximal mixing has been assumed.