Apparent treatment-resistant hypertension among elderly Korean hypertensives: an insight from the HIT registry

The aim of this study was to determine the clinical characteristics of patients with resistant hypertension (RH) and predictors among elderly Korean hypertensives. This prospective, multi-center, observational study evaluated 2439 elderly hypertensive patients between December 2008 and November 2011, who visited secondary hypertension clinics for high blood pressure (BP). Patients were categorized as resistant if their BP was ≥140/90 mm Hg and if they reported using antihypertensive medications from three different drug classes, including a diuretic or drugs from ≥4 antihypertensive drug classes, regardless of BP. Characteristics of patients with RH were compared with those of patients who were controlled with one or two antihypertensive medications after 6-month antihypertensive treatment. In comparison with 837 patients with non-RH, 404 patients with RH were more likely to be aware of their status of high BP before enrollment and have a high baseline systolic BP ≥160 mm Hg, microalbuminuria, high body mass index (BMI) ≥24 kg m(-2) and diabetes mellitus (DM). In drug-naive patients, awareness of hypertension at baseline was the only independent predictor for RH. In elderly Korean hypertensives, BMI (≥24 kg m(-2)), baseline systolic BP (≥160 mm Hg), microalbuminuria, DM and awareness of hypertension showed an association with RH.

Prognostic significance of the interval between the initiation of antiretroviral therapy and the initiation of anti-tuberculosis treatment in HIV/tuberculosis-coinfected patients: results from the TREAT Asia HIV Observational Database

OBJECTIVES

We evaluated the effect of the time interval between the initiation of antiretroviral therapy (ART) and the initiation of tuberculosis (TB) treatment on clinical outcomes in HIV/TB-coinfected patients in an Asian regional cohort.

METHODS

Adult HIV/TB-coinfected patients in an observational HIV-infected cohort database who had a known date of ART initiation and a history of TB treatment were eligible for study inclusion. The time interval between the initiation of ART and the initiation of TB treatment was categorized as follows: TB diagnosed while on ART, ART initiated ≤ 90 days after initiation of TB treatment ('early ART'), ART initiated > 90 days after initiation of TB treatment ('delayed ART'), and ART not started. Outcomes were assessed using survival analyses.

RESULTS

A total of 768 HIV/TB-coinfected patients were included in this study. The median CD4 T-cell count at TB diagnosis was 100 [interquartile range (IQR) 40-208] cells/μL. Treatment outcomes were not significantly different between the groups with early ART and delayed ART initiation. Kaplan-Meier analysis indicated that mortality was highest for those diagnosed with TB while on ART (3.77 deaths per 100 person-years), and the prognoses of other groups were not different (in deaths per 100 person-years: 2.12 for early ART, 1.46 for delayed ART, and 2.94 for ART not started). In a multivariate model, the interval between ART initiation and TB therapy initiation did not significantly impact all-cause mortality.

CONCLUSIONS

A negative impact of delayed ART in patients coinfected with TB was not observed in this observational cohort of moderately to severely immunosuppressed patients. The broader impact of earlier ART initiation in actual clinical practice should be monitored more closely.

Trans-ancestral studies fine map the SLE-susceptibility locus TNFSF4

We previously established an 80 kb haplotype upstream of TNFSF4 as a susceptibility locus in the autoimmune disease SLE. SLE-associated alleles at this locus are associated with inflammatory disorders, including atherosclerosis and ischaemic stroke. In Europeans, the TNFSF4 causal variants have remained elusive due to strong linkage disequilibrium exhibited by alleles spanning the region. Using a trans-ancestral approach to fine-map the locus, utilising 17,900 SLE and control subjects including Amerindian/Hispanics (1348 cases, 717 controls), African-Americans (AA) (1529, 2048) and better powered cohorts of Europeans and East Asians, we find strong association of risk alleles in all ethnicities; the AA association replicates in African-American Gullah (152,122). The best evidence of association comes from two adjacent markers: rs2205960-T (P=1.71 × 10(-34) , OR=1.43[1.26-1.60]) and rs1234317-T (P=1.16 × 10(-28) , OR=1.38[1.24-1.54]). Inference of fine-scale recombination rates for all populations tested finds the 80 kb risk and non-risk haplotypes in all except African-Americans. In this population the decay of recombination equates to an 11 kb risk haplotype, anchored in the 5' region proximal to TNFSF4 and tagged by rs2205960-T after 1000 Genomes phase 1 (v3) imputation. Conditional regression analyses delineate the 5' risk signal to rs2205960-T and the independent non-risk signal to rs1234314-C. Our case-only and SLE-control cohorts demonstrate robust association of rs2205960-T with autoantibody production. The rs2205960-T is predicted to form part of a decameric motif which binds NF-κBp65 with increased affinity compared to rs2205960-G. ChIP-seq data also indicate NF-κB interaction with the DNA sequence at this position in LCL cells. Our research suggests association of rs2205960-T with SLE across multiple groups and an independent non-risk signal at rs1234314-C. rs2205960-T is associated with autoantibody production and lymphopenia. Our data confirm a global signal at TNFSF4 and a role for the expressed product at multiple stages of lymphocyte dysregulation during SLE pathogenesis. We confirm the validity of trans-ancestral mapping in a complex trait.

Anti-bacterial and anti-toxic immunity induced by a killed whole-cell-cholera toxin B subunit cholera vaccine is essential for protection against lethal bacterial infection in mouse pulmonary cholera model

The lack of appropriate animal model for studying protective immunity has limited vaccine development against cholera. Here, we demonstrate a pulmonary cholera model conferred by intranasal administration of mice with live Vibrio cholerae. The bacterial components, but not cholera toxin, caused lethal and acute pneumonia by inducing massive inflammation. Intranasal immunization with Dukoral, comprising killed whole bacteria and recombinant cholera toxin B subunit (rCTB), developed both mucosal and systemic antibody responses with protection against the lethal challenge. Either rCTB-free Dukoral or rCTB alone partially protected the mice against the challenge. However, reconstitution of rCTB-free Dukoral with rCTB restored full protection. Parenteral immunization with Dukoral evoked strong systemic immunity without induction of mucosal immunity or protection from the challenge. These results suggest that both anti-bacterial and anti-toxic immunity are required for protection against V. cholerae-induced pneumonia, and this animal model is useful for pre-clinical evaluation of candidate cholera vaccines.

Interrupting gel layer between Double cuffs prevents fluid leakage past tracheal tube cuffs

BACKGROUND

Current tracheal tubes (TTs) cannot guarantee a perfect seal against pulmonary aspiration of upper airway secretions. The purpose of this study was to investigate whether a gel layer between the tracheal tube with double cuffs (Double cuffs) prevents fluid leakage past TT cuffs.

METHODS

In vitro fluid leakage tests were performed using the Double cuff with or without a gel layer between the two cuffs and four commercially available TTs (Euromedical Standard TT, Mallinckrodt Hi-Lo™, Microcuff, and Mallinckrodt TaperGuard™) when placed in artificial tracheas with three-different internal diameters (ID; 16, 20, and 22 mm). Blue-dyed water (5 ml) was placed above the cuff, and the extent of fluid leakage was observed for 48 h. Each test was repeated five times with new tubes at six different intracuff pressures (15, 20, 25, 30, 40, and 50 cm H2O).

RESULTS

In all of the conventional TTs and the Double cuff without a gel layer, fluid leakage was observed even at clinically acceptable intracuff pressures (25-30 cm H2O). However, in the Double cuff with a gel layer, no fluid leakage was observed for 48 h at all intracuff pressures in three-different sized artificial tracheas. At an intracuff pressure of 20 cm H2O in a 20 mm ID trachea, the average volume of injected gel was 2.0 ml. After removal of the TT, the mean volume of the remaining gel in the trachea was 0.10 ml.

CONCLUSIONS

A prototype TT with gel-layered Double cuffs completely blocked fluid leakage past the cuffs for 48 h in a bench-top model. Clinical studies are required to determine whether this TT reduces the risk of ventilator-associated pneumonia.

Effect of thermal dissipation by adding graphene materials to surface coating of LED lighting module

The effect of thermal dissipation by adding graphene nano-platelets to two different commercially available thermal dissipation coatings (ceramic coating and powder coating) was studied. Steady state temperatures of each points of LED modules was monitored in a closed system, with an integral photo detection sphere where there is no external air flow. Having eliminated the contributions of thermal conduction and air flow convection, the module with a conventional heat dissipation coatings showed 8-16% enhancement of thermal dissipation compared to that of non-coated LED module. The addition of graphene is shown to have about 3% additional enhancement. By analyzing thermal resistance of each component of the LED module, the improved thermal conductivity of the graphene added coatings contributes to the enhancement of slight improvement with heat dissipation.

Formation of polymersomes with double bilayers templated by quadruple emulsions

Polymersomes, vesicles composed of bilayer membranes of amphiphilic block-copolymers, are promising delivery vehicles for long-term storage and controlled release of bioactives; enhanced stability of the membrane makes polymersomes potentially useful in a wide range of biological delivery applications by comparison with liposomes. However, unilamellar structure is intrinsically fragile when subjected to external stress. Here, we report a microfluidic approach to produce polymersomes with double bilayers, providing higher stability and lower permeability than unilamellar polymersomes. To achieve this, we developed a new design of a capillary microfluidic device to produce quadruple-emulsion drops which serve as a template for the polymersomes-in-polymersomes. When two bilayers are attracted by depletion in polymersomes-in-polymersomes, the inner polymersomes protrude and bud, forming double bilayers. We confirm these structures are indeed double bilayers using microaspiration and selective doping of the leaflets with nanoparticles. The resultant polymersomes have great potential as highly stable and biocompatible microcarriers for robust encapsulation and storage of bioactives such as drugs, cosmetics and nutrients.

The effect of the jaw-thrust manoeuvre on the ability to advance a tracheal tube over a bronchoscope during oral fibreoptic intubation

During fibreoptic intubation, it is often difficult to advance a tracheal tube over the fibreoptic bronchoscope. We performed a prospective randomised study to investigate the effect of the jaw-thrust manoeuvre on the ability to advance a tracheal tube during oral fibreoptic intubation. After placing the bronchoscope in the trachea, an assistant randomly applied a jaw-thrust manoeuvre (jaw-thrust group) or sham manoeuvre (control group) in 82 patients during tube advancement. The jaw-thrust group had a higher success rate on the first attempt (70.7% vs 34.1%, p = 0.002), required fewer attempts (median (IQR [range]) 1 (1-2 [1-3]) vs 2 (1-3 [1-4]), p < 0.001), and took less time [6 (4-8 [2-16]) s vs 10 (7-15 [3-40]) s, p < 0.001] for tube advancement compared with the control group. The jaw-thrust manoeuvre facilitates the advancement of a tracheal tube over the bronchoscope during oral fibreoptic intubation.

Ancient colonization and within-island vicariance revealed by mitochondrial DNA phylogeography of the mountain hare (Lepus timidus) in Hokkaido, Japan

We examined the phylogenetic status and history of the mountain hare Lepus timidus in and around Hokkaido using mitochondrial cytochrome b (cyt b) sequences from 158 samples from Hokkaido and 14 from Sakhalin, as well as four samples from the Korean hare, L. coreanus. The phylogenetic analysis of the cyt b sequences generated in this study and obtained from DNA databases showed the clear genetic specificity of the Hokkaido lineage as a clade. The Hokkaido lineage was estimated to have diverged from the other conspecific and L. coreanus lineages 0.46 and 0.30 million years ago (Mya), respectively. These results suggest that the common ancestor of the mitochondrial lineage in Hokkaido and Korea inhabited Far East Asia before colonization by the present continental lineages of L. timidus, including the Sakhalin population. We estimated the time of the most recent common ancestor of the Hokkaido population to be 0.17 Mya, and found two distinct haplogroups within the island. One group had greater genetic diversity (mean number of pairwise differences: π = 0.0188 ± 0.0108) and appears to have expanded from the west to the entire island of Hokkaido. The other had lower genetic diversity (π = 0.0038 ± 0.0037) and its distribution was concentrated in the east. These contrasting west/east trends indicate that the Hokkaido population was fragmented in the past, and then subsequently expanded. Our study suggests that Hokkaido was an important refugium for boreal species in the far eastern region, and allowed the formation of various population genetic structures within the island.

Insights into Korean red fox (Vulpes vulpes) based on mitochondrial cytochrome b sequence variation in East Asia

The red fox (Vulpes vulpes) is the most widely distributed terrestrial carnivore in the world, occurring throughout most of North America, Europe, Asia, and North Africa. In South Korea, however, this species has been drastically reduced due to habitat loss and poaching. Consequently, it is classified as an endangered species in Korea. As a first step of a planned red fox restoration project, preserved red fox museum specimens were used to determine the genetic status of red foxes that had previously inhabited South Korea against red foxes from neighboring countries. Total eighty three mtDNA cytochrome b sequences, including 22 newly obtained East Asian red fox sequences and worldwide red fox sequences from NCBI, were clustered into three clades (i.e., I, II, and III) based on haplotype network and neighbor-joining trees. The mean genetic distance between clades was 2.0%. Clade III contained South Korean and other East Asian samples in addition to Eurasian and North Pacific individuals. In clade III, South Korean individuals were separated into two lineages of Eurasian and North Pacific groups, showing unclear phylogeographic structuring and admixture. This suggests that South Korean red fox populations may have been composed of individuals from these two different genetic lineages.

Polymersomes containing a hydrogel network for high stability and controlled release

Capillary microfluidic devices are used to prepare monodisperse polymersomes consisting of a hydrogel core and a bilayer membrane of amphiphilic diblock-copolymers. To make polymersomes, water-in-oil-in-water double-emulsion drops are prepared as templates through single-step emulsification in a capillary microfluidic device. The amphiphile-laden middle oil phase of the double-emulsion drop dewets from the surface of the innermost water drop, which contains hydrogel prepolymers; this dewetting leads to the formation of a bilayer membrane. Subsequently, the oil phase completely separates from the innermost water drop, leaving a polymersome. Upon UV illumination of the polymersome, the prepolymers encapsulated within the interior are crosslinked, forming a hydrogel core. The hydrogel network within the polymersomes facilitates sustained release of the encapsulated materials and increases the stability of the polymersomes through the formation of a scaffold to support the bilayer. In addition, this approach provides a facile method to make monodisperse hydrogel particles directly dispersed in water.

Resilience as a possible predictor for psychological distress in chronic spinal cord injured patients living in the community

Objective

To investigate whether higher resilience level predicts low levels of psychological distress in chronic SCI patients living in the community.

Method

Thirty seven patients (mean age 41.5±10.9, male : female=28 : 9) with chronic spinal cord injury (duration 8.35±7.0 years) living in the community are included, who were hospitalized for annual checkups from November, 2010 to May, 2011. First, their spinal cord injury level, completeness and complications were evaluated. The patients completed questionnaires about their educational status, religion, employment status, marital status, medical and psychological history and also the following questionnaires: Hospital Anxiety and Depression Scale (HADS), Connor-Davidson Resilience Scale (CD-RISC), Alcohol Use Disorders Identification Test-alcohol consumption questions (AUDIT-C) and Health-related quality of life (EQ-5D). The patients were divided into two subgroups: patients with HADS ≥13 are classified as high psychological distress group and others as low psychological distress group. We compared the two groups to find statistically significant differences among the variables.

Results

CD-RISC, EQ-5D and employment status are significantly different between two groups (p<0.05). In a forward stepwise regression, we found that EQ-5D had a greater contribution than CD-RISC to the psychological distress level.

Conclusion

In addition to health-related quality of life, resilience can be suggested as a possible predictor of psychological distress in chronic SCI patients.

Bryostatin-1 promotes long-term potentiation via activation of PKCα and PKCε in the hippocampus

Activation of protein kinase C (PKC) by bryostatin-1 affects various functions of the central nervous system. We explored whether bryostatin-1 influenced synaptic plasticity via a process involving PKC. Our purpose was to examine whether bryostatin-1 affected the induction of hippocampal long-term potentiation (LTP) in Schaffer-collateral fibers (CA1 fibers) of the hippocampus, and/or influenced the intracellular Ca(2+) level of hippocampal neurons. We also determined the PKC isoforms involved in these processes. We found that bryostatin-1 strongly facilitated LTP induction, in a dose-dependent manner, upon single-theta burst stimulation (TBS). Further, intracellular Ca(2+) levels also increased with increasing concentration of bryostatin-1. The facilitative effects of bryostatin-1 in terms of LTP induction and enhancement of intracellular Ca(2+) levels were blocked by specific inhibitors of PKCα and PKCε, but not of PKCδ. Our results suggest that bryostatin-1 is involved in neuronal functioning and facilitates induction of LTP via activation of PKCα and/or PKCε.

Anti-inflammatory effect of sinomenine by inhibition of pro-inflammatory mediators in PMA plus A23187-stimulated HMC-1 Cells

BACKGROUND AND OBJECTIVES

Sinomenine is an alkaloid compound and a prominent anti-inflammatory agent found in the root of the climbing plant Sinomenium acutum. However, its effects on the mechanism of human mast cell line (HMC)-1-mediated inflammation remained unknown.

MATERIALS AND METHODS

To provide insight into the biological effects of sinomenine, we examined its influence on the pro-inflammatory cytokine production in HMC-1 cells stimulated by phorbol 12-myristate-13-acetate (PMA) plus A23187 by evaluating the stimulated cells in the presence or absence of sinomenine. In the present study, the pro-inflammatory cytokine production was measured using ELISA, Reverse Transcription-polymerase chain reaction (RT-PCR) and nuclear factor (NF)-kappaB, mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Also, cyclooxygenase (COX)-2 expression was measured through Western blot and RT-PCR analysis.

RESULTS

Sinomenine inhibited the pro-inflammatory cytokine production induced by PMA plus A23187 in a dose-dependent manner. Furthermore, sinomenine inhibited the phosphorylations of extracellular signal-regulated kinase (ERK) and p38 MAPKs as well as the translocation of NF-kappaB p65 through reduced IkappaBalpha degradation. In addition, sinomenine suppressed COX-2 protein and mRNA expression dose-dependently.

CONCLUSIONS

Taken together, the results of this study indicate that the anti-inflammatory effects of sinomenine may occur via the inhibition of pro-inflammatory cytokine and COX-2 production through the inhibition of MAPKs and NF-kappaB pathway activation by PMA plus A23187 stimulation in HMC-1 cells.

Effect of thermal annealing on the efficiency of heterojunction photovoltaic cells fabricated using poly(3-hexylthiophene) and methanofullerene, [6,6]-phenyl C61-butyric acid methyl ester

The effects of thermal annealing on the efficiency of heterojunction photovoltaic (PV) cells that were fabricated using poly(3-hexylthiophene) (P3HT) and methanofullerene, [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were investigated. The absorption spectra showed that the absorption intensity of the P3HT:PCBM layer that was annealed for 5 min had the highest value among the several samples with different annealing temperatures. The atomic force microscopy image showed that the P3HT:PCBM layer that was annealed for 5 min had the best surface morphology. The X-ray photoelectron spectroscopy demonstrated that the P3HT:PCBM layer that was annealed at 140 degrees C for 10 min enhanced the PCBM aggregation on the surface Al layer that was covered by the P3HT:PCBM layer. The efficiencies of the PV cells that were annealed at 3, 5, and 10 min were approximately 2.7, 4.2, and 3.5%, respectively. Based on the experiment results, the variations in the efficiency of the PV cells due their thermal treatment were described.

Narrowing oF the critical hydration window for cryopreservation of Salix caprea seeds following ageing and a reduction in vigour

We investigated the effects of desiccation, rehydration and cryopreservation on the viability of seeds of a wild mountain species and seven clones of Salix caprea L. Seeds responded differently to all treatments depending on clone, seed initial moisture content (MC) and seed vigour. Fresh seeds of two randomly selected clones tolerated desiccation to MC 8.5-9.6 % FW (0.09-0.11 g water per g dry mass. g/gdw) without any noticeable loss in viability and were successfully cryopreserved at MCs ranging from 8.5 to 23.4 % (0.09-0.30 g/gdw). Storage at 5 degree C for approximately 10 weeks significantly reduced the viability of seed lots of a wild species and of three S. caprea clones, whilst viability of seeds of four other clones remained unaffected. Since all clones tested were genetically derived from one tree, this variation is unlikely to be of maternal origin. Most probably paternal x environmental factors have influenced seed behavior during desiccation and storage. As viability decreased due to partial ageing, seeds became more susceptible to desiccation stress. When seeds of three clones were cryopreserved, the hydration window for survival was wider for highly vigorous seeds (c. 0.05-0.28 g/gdw) than for seeds with intermediate vigour (c. 0.10-0.24 g/gdw) and low vigour (c. 0.20-0.37 g/gdw). Rehydration to MC above 0.15 g/gdw improved germination of low vigour seeds, both in controls and after cryopreservation. In contrast, cryopreservation of high vigour seeds rehydrated to MCs above 0.11 g/gdw resulted in a sharp decrease in normal seedling production. Whilst no effect of cryogenic temperature on germination and normal seedling production was observed when seeds of seven clones were cryopreserved within their hydration windows, the results indicate the need to account for seed lot vigour when designing cryopreservation protocols.

Translationally controlled tumour protein is associated with podocyte hypertrophy in a mouse model of type 1 diabetes

AIMS/HYPOTHESIS

Translationally controlled tumour protein (TCTP) is thought to be involved in cell growth by regulating mTOR complex 1 (mTORC1) signalling. As diabetes characteristically induces podocyte hypertrophy and mTORC1 has been implicated in this process, TCTP may have a role in the pathogenesis of diabetes-induced podocyte hypertrophy.

METHODS

We investigated the effects and molecular mechanisms of TCTP in diabetic mice and in high glucose-stimulated cultured podocytes. To characterise the role of TCTP, we conducted lentivirus-mediated gene silencing of TCTP both in vivo and in vitro.

RESULTS

Glomerular production of TCTP was significantly higher in streptozotocin induced-diabetic DBA/2J mice than in control animals. Double-immunofluorescence staining for TCTP and synaptopodin revealed that podocyte was the principal cell responsible for this increase. TCTP knockdown attenuated the activation of mTORC1 downstream effectors and the overproduction of cyclin-dependent kinase inhibitors (CKIs) in diabetic glomeruli, along with a reduction in proteinuria and a decrease in the sizes of podocytes as well as glomeruli. In addition, knockdown of TCTP in db/db mice prevented the development of diabetic nephropathy, as indicated by the amelioration of proteinuria, mesangial expansion, podocytopenia and glomerulosclerosis. In accordance with the in vivo data, TCTP inhibition abrogated high glucose-induced hypertrophy in cultured podocytes, which was accompanied by the downregulation of mTORC1 effectors and CKIs.

CONCLUSIONS/INTERPRETATION

These findings suggest that TCTP might play an important role in the process of podocyte hypertrophy under diabetic conditions via the regulation of mTORC1 activity and the induction of cell-cycle arrest.

Hair greying is associated with active hair growth

BACKGROUND

Hair greying is an obvious sign of ageing in humans. White (nonpigmented) hair is thicker than black (pigmented) hair. The growth rate of white hair is also significantly higher than that of black hair. However, the mechanism underlying this is largely unknown.

OBJECTIVES

To examine the association between hair greying and hair growth patterns by evaluating expression of the genes or proteins related to hair growth in white and black hairs.

METHODS

Morphological characteristics were observed in eyebrow and scalp hairs. The differential expression of genes was analysed in black and white hairs from human scalp by a microarray analysis. Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry for genes and proteins related to hair growth were performed in black and white hairs.

RESULTS

Keratin and keratin-associated protein (KRTAP) genes in white hair were upregulated at least two-fold in comparison with black hair in a microarray analysis. Upregulation of selected keratin genes and KRTAP4 isoform genes in white hair was validated by RT-PCR. Immunoreactivity for KRT6, KRT14/16 and KRT25 was increased in the hair follicle of white hair compared with black hair. Gene expression of fibroblast growth factor 5 (FGF5) was downregulated in white hair compared with black hair. However, gene expression of FGF7 was upregulated in white hair compared with black hair.

CONCLUSIONS

Expression of genes and proteins associated with active hair growth is upregulated in white (nonpigmented) hair compared with black (pigmented) hair. These results suggest that hair greying is associated with active hair growth.

Forensic odontological examination of a 1500 year-old human remain in ancient Korea (Gaya)

Forensic odontological examination was performed on one of the 1500-year old human remains of ancient Korea (Gaya) excavated from a burial site at Songhyeon-dong, Changnyeong, South Korea in April, 2008. The main purpose of the examination was to age estimate the remains and record any dental characteristics to aid full-body reconstruction and life history data collection. Oral and radiographic examinations and metric data collection were conducted. During the oral examination, the following observations were made: dental caries, semi-circular abrasion on the maxillary right lateral incisor and enamel hypoplasia on the left and right canines and first premolars in the mandible. The metric data was similar to that of average metric data of modern Koreans. Age estimation was initially conducted using the degree of dental attrition with methods of Takei and Yun, and was estimated to be approximately 40 years. However, it was observed in the radiographic examination, that the maxillary right second molar, together with the mandibular left and right second and third molars had incompletely developed root apices. The age estimation was then performed using the developmental status of the lower second and third molars. The age was estimated to be approximately 16 years using Lee's method which was consistent with the estimation using forensic anthropology. This case study highlights that the degree of attrition should not be used as a sole indicator for age estimation.

Prevalence of Nosema and Virus in Honey Bee (Apis mellifera L.) Colonies on Flowering Period of Acacia in Korea

Honey production from approximately 1.6 million colonies owned by about 199,000 Korean beekeepers was almost 23,000 metric tons in 2009. Nosema causes significant losses in honey production and the virus decreases population size. We initiated a survey of honey bee colonies on the blooming period of Acacia to determine the prevalence of Nosema and virus in 2011. Most Korean beekeepers have moved from the south to north of Korea to get Acacia nectar for 2 mon. This provided a valuable opportunity to sample bees originating from diverse areas in one location. Twenty hives owned by 18 beekeepers were sampled in this year. Nosema spore counts ranged from zero to 1,710,000 spores per bee. The average number of nosema spores per bee was 580,000. Approximately 95% of the colonies were infected with Nosema, based on the presence of spores in the flowering period of Acacia. This indicates that Nosema is the predominant species affecting honeybee colonies. Also, the seven most important honeybee viruses were investigated by reverse transcription-PCR. Among them, four different viruses were detected in samples. Black queen cell virus was present in all samples. Chronic bee paralysis virus was detected in 10% of samples. Deformed wing virus was present in only 5% of the samples. Prevalence of Sacbrood virus was 15%. However, Cloudy wing virus, Israel acute paralysis virus and kashmir bee virus were not detected in any of samples.

Magnetic field anisotropy based MR tractography

Non-invasive measurements of structural orientation provide unique information regarding the connectivity and functionality of fiber materials. In the present study, we use a capillary model to demonstrate that the direction of fiber structure can be obtained from susceptibility-induced magnetic field anisotropy. The interference pattern between internal and external magnetic field gradients carries the signature of the underlying anisotropic structure and can be measured by MRI-based water diffusion measurements. Through both numerical simulation and experiments, we found that this technique can determine the capillary orientation within 3°. Therefore, susceptibility-induced magnetic field anisotropy may be useful for an alternative tractography method when diffusion anisotropy is small at higher magnetic field strength without the need to rotate the subject inside the scanner.