Risk of fractures and diabetes medications: a nationwide cohort study

The effects of diabetes medications on risk of fracture were investigated using the South Korea nationwide claims database. We demonstrated that the use of dipeptidyl peptidase-4 inhibitor could be associated with decreased risk of fracture. Thiazolidinedione use was associated with about 60 % increased risk of fracture in real clinical practice.

INTRODUCTION

The effects of diabetes medication on fracture have important clinical health consequences, since most diabetes patients are at high risk of fracture. We aimed to investigate the effect of diabetes medication on fracture risk.

METHODS

The nationwide medical claim database in South Korea was investigated. Among 2,886,555 subjects with antidiabetes prescriptions, 207,558 subjects aged 50 years and older, who initiated diabetes medication from 2008 to 2011, were analyzed. The subjects were classified based on diabetes medication classes: non-user (insufficient exposure), metformin (MET), sulfonylurea (SU), alpha-glucosidase inhibitor (AGI), MET + SU, MET + thiazolidinedione (TZD), MET + dipeptidyl peptidase-4 inhibitor (DPP4-I), and SU + TZD.

RESULTS

A total of 5996 fractures were observed. The fracture rate varied significantly across type of diabetes medications, with MET + DPP4-I combination group having the lowest rate and SU + TZD combination group having the highest rate. Compared to non-users, MET + DPP4-I inhibitor combination group had significantly reduced composite fracture risk (hazard ratio (HR) = 0.83, P = 0.025) and significantly reduced vertebral fracture risk (HR = 0.73, P = 0.013) in the unadjusted analysis. Compared to MET + SU users, MET + DPP4-I users showed a trend of lower non-vertebral fracture risk (HR = 0.82, P = 0.086) after adjusting for all confounding variables. Patients using TZD had significantly increased risk of fracture (HR = 1.59, P < 0.001) compared with patients not using TZDs adjusting for all confounding variables.

CONCLUSIONS

The results of this nationwide study showed a trend that DPP4 inhibitor might have a protective effect on bone metabolism compared with SU, when added to MET. Clinicians should take these results into consideration when prescribing diabetes medication, especially in elderly patients or those at high risk or fracture.

Preparedness for use of the rapid result HIV self-test by gay men and other men who have sex with men (MSM): a mixed methods exploratory study among MSM and those involved in HIV prevention and care

Objectives

The aim of the study was to explore preparedness for the HIV self‐test among men who have sex with men (MSM) and those involved in HIV prevention and care.

Methods

A mixed methods exploratory research design was employed, detailing awareness and willingness to use the self‐test and the perceived barriers and facilitators to implementation. Quantitative and qualitative data collection and analysis were completed in parallel. Descriptive and inferential analysis of cross‐sectional bar‐based survey data collected from MSM through a self‐completed questionnaire and oral fluid specimen collection (n = 999) was combined with qualitative, thematic, analysis of data collected through 12 expert focus groups (n = 55) consisting of gay men, National Health Service (NHS) staff, community organizations, entrepreneurs and activists. Findings were subsequently combined and assessed for synergies.

Results

Among MSM, self‐test awareness was moderate (55%). Greater awareness was associated with increased educational attainment [adjusted odds ratio 1.51; 95% confidence interval (CI) 1.00–2.30; P = 0.05] and previous history of sexually transmitted infection (STI) testing (adjusted odds ratio 1.63; 95% CI 1.11–2.39; P = 0.01). Willingness to use the test was high (89%) and associated with meeting sexual partners online (unadjusted odds ratio 1.96; 95% CI 1.31–2.94; P < 0.001). Experts highlighted the overall acceptability of self‐testing; it was understood as convenient, discreet, accessible, and with a low burden to services. However, some ambivalence towards self‐testing was reported; it could reduce opportunities to engage with wider services, wider health issues and the determinants of risk.

Conclusions

Self‐testing represents an opportunity to reduce barriers to HIV testing and enhance prevention and access to care. Levels of awareness are moderate but willingness to use is high. Self‐testing may amplify health inequalities.

Distribution of the supremum of the two-parameter Yeh-Wiener process on the boundary

Let D = [0, S] × [0, T] be a rectangle in E2 and X(s, t), (s, t)∈D, be a two parameter Yeh-Wiener process. This paper finds the probability distribution of the supremum of X(s, t) on the boundary of D by taking the limit of the probability distribution of the supremum of X(s, t) along certain paths as these paths approach the boundary of D. The probability distribution of the supremum of X(s, t) on the boundary of D gives a nice lower bound for the probability distribution of the supremum of X(s, t) on D, which is unknown.

Evaluations of barrier-crossing probabilities of Wiener paths

Let {W(t), 0 ≦ t < ∞} be the standard Wiener process. The main purpose of this paper is to present ways of obtaining probabilities of Wiener paths crossing certain curves on various intervals. The results are extended to other kinds of Gaussian processes.

Evaluations of absorption probabilities for the Wiener process on large intervals

Let {W(t), 0≦t<∞} be the standard Wiener process. The computation schemes developed in the past are not computationally efficient for the absorption probabilities of the type P{sup0≦t≦TW(t) − f(t) ≧ 0} when either T is large or f(0) > 0 is small. This paper gives an efficient and accurate algorithm to compute such probabilities, and some applications to other Gaussian stochastic processes are discussed.

Stochastic barriers for the Wiener process

Let {W(t), 0 ≦ t < ∞} be the standard Wiener process. The probabilities of the type P[sup0≦t ≦ TW(t) − f(t) ≧ 0] have been extensively studied when f(t) is a deterministic function. This paper discusses the probabilities of the type P{sup0≦t ≦ TW(t) − [f(t) + X(t)] ≧ 0} when X(t) is a stochastic process. By taking compound Poisson processes as X(t), the paper gives procedures for finding such probabilities.

Boundaries with negative jumps for the Brownian motion

First-exit-time problems for Brownian motion have been studied extensively because of their theoretical importance as well as their practical applications. Except for a very few special cases such as straight-line barriers, the distribution (or density) of the first-exit time cannot be expressed in a closed form. In general the distribution and the density appear as solutions of Volterra integral equations. To solve such an equation analytically, some regularity conditions are needed for the barrier function including differentiability. This paper gives various integral equations involving the distribution and the density of the first-exit time for any sectionally continuous barrier, and then shows how to solve those integral equations numerically.

Sequence variations of the locus-specific 5' untranslated regions of SLA class I genes and the development of a comprehensive genomic DNA-based high-resolution typing method for SLA-2

The genetic diversity of the major histocompatibility complex (MHC) class I molecules of pigs has not been well characterized. Therefore, the influence of MHC genetic diversity on the immune-related traits of pigs, including disease resistance and other MHC-dependent traits, is not well understood. Here, we attempted to develop an efficient method for systemic analysis of the polymorphisms in the epitope-binding region of swine leukocyte antigens (SLA) class I genes. We performed a comparative analysis of the last 92 bp of the 5' untranslated region (UTR) to the beginning of exon 4 of six SLA classical class I-related genes, SLA-1, -2, -3, -4, -5, and -9, from 36 different sequences. Based on this information, we developed a genomic polymerase chain reaction (PCR) and direct sequencing-based comprehensive typing method for SLA-2. We successfully typed SLA-2 from 400 pigs and 8 cell lines, consisting of 9 different pig breeds, and identified 49 SLA-2 alleles, including 31 previously reported alleles and 18 new alleles. We observed differences in the composition of SLA-2 alleles among different breeds. Our method can be used to study other SLA class I loci and to deepen our knowledge of MHC class I genes in pigs.

High pressure and temperature equation of state and spectroscopic study of CeO2

One of the most widely used x-ray standards and a highly applied component of catalysis systems, CeO2 has been studied for the purpose of better understanding its equation of state and electronic properties. Diamond anvil cells have been used to extend the equation of state for this material to 130 GPa and explore the electronic behavior with applied load. From the x-ray diffraction studies, it has been determined that the high pressure phase transition extends from approximately 35-75 GPa at ambient temperature. Elevation of temperature is found to decrease the initiation pressure for this transition, with multiple distinct temperature regions which indicate structural related anomalies. In addition, hydrostatic and non-hydrostatic effects are compared and exhibit a drastic difference in bulk moduli. The electronic results indicate a change in the scattering environment of the cerium atom, associated with the high pressure phase transition. Overall, these results present the first megabar pressure study and the first high pressure and temperature study of ceria. Additionally, this shows the first combined study of the K and L III edges of this material to 33 GPa.

Viral dynamic modelling of Hepatitis C and resistance-associated variants in haemophiliacs

AIM

Chronic hepatitis C virus (HCV) infection is an important source of morbidity and mortality among haemophiliacs. Limited data are available regarding treatment intervention using direct-acting antivirals (DAAs) and theoretical concerns regarding accumulation of drug-associated resistance variants (RAVs) remain. We conducted a pilot study of treatment with telaprevir/pegylated interferon-alfa/ribavirin to evaluate treatment response and the role of lead-in DAA therapy on mutational selection of resistance variants.

METHODS

Ultra-deep sequence analysis was performed at baseline, 48 hours and 168 hours after treatment initiation.

RESULTS

No dominant RAVs were identified at baseline, but low-level RAVs were noted at baseline in all subjects. Viral dynamic models were used to assess treatment responses. The efficacy parameter (Ɛ) for lead-in ranged from 0 to 0.9745 (mean = 0.514). Subsequent addition of telaprevir resulted in a mean efficacy of more than 0.999. This was comparable to subjects who started all three medications simultaneously. A total of 80% achieved SVR. While rapid shifts in the RAV population following DAA initiation were observed, treatment failure associated with A156V was observed in only one patient. Adverse event profiles were similar to that observed in non-haemophilia cohorts. There was no evidence of factor inhibitor formation. There was no evidence that lead-in provided benefit in terms of response efficacy.

CONCLUSION

These data support DAA-based therapy in those with inherited bleeding disorders.

Thermodynamic approach to boron nitride nanotube solubility and dispersion

Inadequate dispersion of nanomaterials is a critical issue that significantly limits the potential properties of nanocomposites and when overcome, will enable further enhancement of material properties. The most common methods used to improve dispersion include surface functionalization, surfactants, polymer wrapping, and sonication. Although these approaches have proven effective, they often achieve dispersion by altering the surface or structure of the nanomaterial and ultimately, their intrinsic properties. Co-solvents are commonly utilized in the polymer, paint, and art conservation industries to selectively dissolve materials. These co-solvents are utilized based on thermodynamic interaction parameters and are chosen so that the original materials are not affected. The same concept was applied to enhance the dispersion of boron nitride nanotubes (BNNTs) to facilitate the fabrication of BNNT nanocomposites. Of the solvents tested, dimethylacetamide (DMAc) exhibited the most stable, uniform dispersion of BNNTs, followed by N,N-dimethylformamide (DMF), acetone, and N-methyl-2-pyrrolidone (NMP). Utilizing the known Hansen solubility parameters of these solvents in comparison to the BNNT dispersion state, a region of good solubility was proposed. This solubility region was used to identify co-solvent systems that led to improved BNNT dispersion in poor solvents such as toluene, hexane, and ethanol. Incorporating the data from the co-solvent studies further refined the proposed solubility region. From this region, the Hansen solubility parameters for BNNTs are thought to lie at the midpoint of the solubility sphere: 16.8, 10.7, and 9.0 MPa(1/2) for δd, δp, and δh, respectively, with a calculated Hildebrand parameter of 21.8 MPa(1/2).

Comparison of commercial type 1 and type 2 PRRSV vaccines against heterologous dual challenge

This study was to compare the effect of vaccination of pigs with either type 1 or type 2 porcine reproductive and respiratory syndrome virus (PRRSV) against heterologous dual challenge of both genotypes. Pigs were administered type 1 (UNISTRAIN PRRS) or type 2 (Fostera PRRS) PRRSV vaccine at 28 days of age and inoculated intranasally with both genotypes at 63 days of age. Vaccination of pigs with type 1 PRRSV was able to reduce the levels of type 1 but not type 2 PRRSV viraemia, whereas vaccination of pigs with type 2 PRRSV was able to reduce the levels of type 1 and type 2 PRRSV viraemia against a dual challenge. Vaccination of pigs with type 2 PRRSV significantly reduced lung lesions after dual challenge compared with vaccination of pigs with type 1 PRRSV. Vaccination of pigs with type 2 PRRSV induced higher numbers of type 1 and type 2 PRRSV-specific interferon-γ secreting cells compared with vaccination of pigs with type 1 PRRSV after dual challenge. The results of this study demonstrated that vaccination of pigs with type 2 PRRSV is efficacious in protecting growing pigs from respiratory disease after heterologous dual type 1 and type 2 PRRSV challenge compared with vaccination of pigs with type 1 PRRSV.

In-situ Hybridization for the Detection of Sacbrood Virus in Infected Larvae of the Honey Bee (Apis cerana)

The aim of this study was to develop and use in-situ hybridization (ISH) for the detection and localization of the sacbrood virus (SBV) in Korean honey bee (Apis cerana) larvae that were infected naturally with SBV. A 258 base pair cDNA probe for SBV was generated by polymerase chain reaction. Cells positive for viral genome typically showed a dark brown reaction in the cytoplasm. SBV was detected consistently in trophocytes and urocytes. The ISH was successfully applied to routinely fixed and processed tissues and thus should prove helpful in the diagnosis and characterization of viral distribution in infected larvae.

Differential Expression of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Open Reading Frame 5, but not Apoptogenic Cytokines, Contribute to Severe Respiratory Disease in Pigs Infected with Type 2 PRRSV Compared with Pigs Infected with Type 1 PRRSV

The aim of this study was to compare the expression of open reading frame 5 (ORF5) of porcine reproductive and respiratory syndrome virus (PRRSV) and apoptogenic cytokines in the lungs from pigs infected with type 1 and type 2 PRRSV. Microscopical lung lesion scores and the mean number of apoptotic cells were significantly (P <0.05) higher in pigs with type 2 PRRSV infection than in those with type 1 PRRSV infection. The score for the mean number of PRRSV ORF5-positive cells per unit area of lung was significantly (P <0.05) higher in pigs with type 2 PRRSV infection. There were no significant differences in the expression of tumour necrosis factor-α and interleukin-1 in lung tissues between type 1 and type 2 PRRSV-infected pigs. The severity of microscopical lung lesions and the number of apoptotic cells correlated well with the number of PRRSV ORF5-positive cells. Therefore, differential expression of PRRSV ORF5, but not apoptogenic cytokines, may attribute to the severity of lung lesions and apoptosis in lungs in PRRSV infection. These results suggest that expression of PRRSV ORF5 may be a critical determinant for different virulence between PRRSV genotypes in terms of respiratory disease.

Pressure-induced phase transitions of β-type pyrochlore CsTaWO6

The β-type pyrochlore CsTaWO₆ was studied by synchrotron X-ray diffraction (XRD) and Raman scattering methods up to pressures of 43 GPa using a diamond anvil cell (DAC).

Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy

Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter treatment times and 50% lower number of delivered monitor units (MU) were achievable with CyberKnife-multi-leaf collimator than with CyberKnife-Iris. The CyberKnife-multi-leaf collimator treatment times were comparable to 3-dimensional conformal radiotherapy, however, the number of MU delivered was approximately 2.5 times larger. The suitability of 10 + 2 mm margins warrants further investigation.

High pressure Laue diffraction and its application to study microstructural changes during the α → β phase transition in Si

An approach using polychromatic x-ray Laue diffraction is described for studying pressure induced microstructural changes of materials under pressure. The advantages of this approach with respect to application of monochromatic x-ray diffraction and other techniques are discussed. Experiments to demonstrate the applications of the method have been performed on the α → β phase transition in Si at high pressures using a diamond anvil cell. We present the characterization of microstructures across the α-β phase transition, such as morphology of both the parent and product phases, relative orientation of single-crystals, and deviatoric strains. Subtle inhomogeneous strain of the single-crystal sample caused by lattice rotations becomes detectable with the approach.

Human breast cancer invasion and aggression correlates with ECM stiffening and immune cell infiltration

Tumors are stiff and data suggest that the extracellular matrix stiffening that correlates with experimental mammary malignancy drives tumor invasion and metastasis. Nevertheless, the relationship between tissue and extracellular matrix stiffness and human breast cancer progression and aggression remains unclear. We undertook a biophysical and biochemical assessment of stromal-epithelial interactions in noninvasive, invasive and normal adjacent human breast tissue and in breast cancers of increasingly aggressive subtype. Our analysis revealed that human breast cancer transformation is accompanied by an incremental increase in collagen deposition and a progressive linearization and thickening of interstitial collagen. The linearization of collagen was visualized as an overall increase in tissue birefringence and was most striking at the invasive front of the tumor where the stiffness of the stroma and cellular mechanosignaling were the highest. Amongst breast cancer subtypes we found that the stroma at the invasive region of the more aggressive Basal-like and Her2 tumor subtypes was the most heterogeneous and the stiffest when compared to the less aggressive luminal A and B subtypes. Intriguingly, we quantified the greatest number of infiltrating macrophages and the highest level of TGF beta signaling within the cells at the invasive front. We also established that stroma stiffness and the level of cellular TGF beta signaling positively correlated with each other and with the number of infiltrating tumor-activated macrophages, which was highest in the more aggressive tumor subtypes. These findings indicate that human breast cancer progression and aggression, collagen linearization and stromal stiffening are linked and implicate tissue inflammation and TGF beta.

Two Commercial Type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-Modified Live Vaccines Reduce Seminal Shedding of Type 1 PRRSV but not Type 2 PRRSV in Infected Boars

The objective of this study was to compare the effects of two commercial type 1 porcine reproductive and respiratory syndrome virus (PRRSV)-modified live vaccines on type 1 and type 2 PRRSV shedding in the semen of experimentally infected boars. Upon challenge with PRRSV, unvaccinated boars exhibited an increase in daily rectal temperature (39.4-39.7°C). Vaccination of boars with type 1 PRRSV significantly reduced the amount of type 1 PRRSV load in blood and semen after challenge with type 1 PRRSV, but barely reduced the amount of type 2 PRRSV load in blood and semen after the type 2 PRRSV challenge. There were no significant differences in the reduction of viremia and seminal shedding of type 1 and type 2 PRRSV between the two commercial vaccines. The seminal shedding of PRRSV is independent of viremia. The reduction of type 1 PRRSV seminal shedding coincided with the appearance of type 1 PRRSV-specific interferon-γ secreting cells (IFN-γ-SC) in vaccinated type 1 PRRSV-challenged boars. The frequencies of type 1 PRRSV-specific IFN-γ-SC induced by type 1 PRRSV vaccine are relatively high compared to type 2 PRRSV-specific IFN-γ-SC induced by the same vaccine which may explain why type 1 PRRSV vaccine is more effective in reducing seminal shedding of type 1 PRRSV when compared to type 2 PRRSV in vaccinated challenged boars. These results provide clinical information on how to reduce seminal shedding of type 1 PRRSV in boars using type 1 PRRSV-modified live vaccine.

Gestational autoimmune disease in newborns with an indeterminate cause of death following a complete autopsy

Gestational alloimmune liver disease (GALD) is the result of neonatal complement-mediated severe liver injury mediated by maternal alloantibodies, which is detected by immunohistochemistry staining for the complement C5b-9 complex. GALD leads to the neonatal hemochromatosis (NH) phenotype, which also shows extrahepatic siderosis, and can result in neonatal death. At autopsy, the histologic damage of the liver in GALD may be subtle and misinterpreted as non-specific post-mortem changes, resulting in the cause of death classified as indeterminate. We reviewed the pathologic diagnoses from autopsy material from 1996 to 2011 of infants 0-90 days of age from our institution. Liver samples were stained with H&E, trichrome and for C5b-9. 13 cases originally diagnosed as indeterminate cause of death were identified and divided in 3 groups: (1) No clinical or autopsy-derived diagnoses (n = 7), (2) Defined clinical diagnoses but no cause of death determined at autopsy (n = 2), and (3) Liver disease, but no clinical or autopsy diagnoses to establish the cause of the liver injury (n = 4). On reexamination, all group 1 and 3 cases were reclassified as GALD, based on a positive C5b-9 stain. Group 2 cases were not GALD, retaining the original, clinically-based cause of death. We conclude that, in cases of indeterminate cause of neonatal death, very careful examination for hepatocyte injury/necrosis, extrahepatic siderosis, liver fibrosis and/or C5b-9 stain should be considered.

Observation and quantification of nanoscale processes in lithium batteries by operando electrochemical (S)TEM

An operando electrochemical stage for the transmission electron microscope has been configured to form a "Li battery" that is used to quantify the electrochemical processes that occur at the anode during charge/discharge cycling. Of particular importance for these observations is the identification of an image contrast reversal that originates from solid Li being less dense than the surrounding liquid electrolyte and electrode surface. This contrast allows Li to be identified from Li-containing compounds that make up the solid-electrolyte interphase (SEI) layer. By correlating images showing the sequence of Li electrodeposition and the evolution of the SEI layer with simultaneously acquired and calibrated cyclic voltammograms, electrodeposition, and electrolyte breakdown processes can be quantified directly on the nanoscale. This approach opens up intriguing new possibilities to rapidly visualize and test the electrochemical performance of a wide range of electrode/electrolyte combinations for next generation battery systems.

Blockade of CD40-CD154 costimulatory pathway promotes long-term survival of full-thickness porcine corneal grafts in nonhuman primates: clinically applicable xenocorneal transplantation

The porcine cornea may be a good solution for the shortage of human donor corneas because its size and refractive properties are comparable to those of the human cornea. However, antigenic differences need to be overcome to apply xenocorneal transplantation in actual clinical practice. We aimed to investigate the feasibility of full-thickness porcine corneas as human corneal substitutes using a CD40-CD154 costimulatory pathway blocking strategy in a clinically applicable pig-to-nonhuman primate corneal transplantation model. As a result, the mean survival time of the xenocorneal grafts in recipients who received anti-CD154 antibody-based immunosuppressants (POD318 (n = 4); >933, >243, 318 and >192) was significantly longer than that in controls (POD28 (n = 3); 21, 28 and 29; p = 0.010, log-rank test). Administration of anti-CD154 antibodies markedly reduced inflammatory cellular infiltrations (predominantly CD8 T cells and macrophages) into the xenocorneal grafts and almost completely blocked xenoantigen-triggered increases in Th1-associated cytokines, chemokines and C3a in the aqueous humor. Moreover, systemic expansion of memory T cells was effectively controlled and responses of anti-Gal/donor pig-specific antibodies were considerably diminished by programmed injection of anti-CD154 antibodies. Consequently, porcine corneas might be promising human corneal substitutes when the transplantation is accompanied by potent immunosuppression such as a CD40-CD154 costimulatory pathway blockade.