CHRNA5 variants moderate the effect of nicotine deprivation on a neural index of cognitive control

Individuals with reduced attention and memory cognitive control-related processes may be motivated to smoke as a result of the cognitive enhancing effects of nicotine. Further, nicotine deprivation-induced reductions in cognitive control may negatively reinforce smoking. Minor allele carriers at rs16969968 in the nicotinic acetylcholine receptor α5 subunit gene (CHRNA5) have been shown to exhibit both reduced cognitive control and greater nicotine dependence. It is therefore of interest to see if variants in this gene moderate the influence of nicotine deprivation on cognitive control. P3b and P3a components of the event-related brain potential waveform evoked by a three-stimulus visual oddball task are widely viewed as positive indices of cognitive control-related processes. We tested the hypothesis that individuals possessing at least one minor allele at rs16969968 in CHRNA5 would show greater nicotine deprivation-induced reductions in P3b and P3a amplitude. The sample included 72 non-Hispanic, Caucasian heavy smokers (54 men and 18 women) with a mean age of 36.11 years (SD = 11.57). Participants completed the visual oddball task during counterbalanced nicotine and placebo smoking sessions. Findings indicated that rs16969968 status did not moderate nicotine effects on P3b or P3a, whereas variation in other CHRNA5 polymorphisms, which are not as well characterized and are not in linkage disequilibrium with rs16969968, predicted nicotine deprivation-induced reduction of P3a amplitude: rs588765 (F1,68 = 7.74, P = 0.007) and rs17408276 (F1,67 = 7.34, P = 0.009). Findings are interpreted in the context of vulnerability alleles that may predict nicotine effects on cognitive control.

Charge transport in light emitting devices based on colloidal quantum dots and a solution-processed nickel oxide layer

We fabricated hybrid light emitting devices based on colloidal CdSe/ZnS core/shell quantum dots and a solution-processed NiO layer. The use of a sol-gel NiO layer as a hole injection layer (HIL) resulted in overall improvement in device operation compared to a control device with a more conventional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) HIL. In particular, luminous efficiency increased substantially because of the suppression of excessive currents and became as large as 2.45 cd/A. To manifest the origin of current reduction, temperature- and electric field-dependent variations of currents with respect to bias voltages were investigated. In a low bias voltage range below the threshold for luminance turn-on, the Poole-Frenkel (PF) emission mechanism was responsible for the current-density variation. However, the space-charge-limited current modified with PF-type mobility ruled the current-density variation in high bias voltage range above the threshold.

Prognostic value of model for end-stage liver disease scores in patients with fulminant hepatic failure

BACKGROUND

This study was undertaken to investigate risk factors of mortality in patients with fulminant hepatic failure (FHF).

METHODS

Fifty-three patients with FHF treated from January 2006 to April 2011 were allocated to a spontaneous survival group (group 1), a death without liver transplantation (LT) group (group 2), and an LT group (group 3). To analyze risk factors associated with mortality in FHF, we excluded group 3 patients. Clinical features, Model for End-Stage Liver Disease (MELD) scores, and King's College Hospital criteria at the time of hepatic encephalopathy in group 2 were compared with those of group 1.

RESULTS

The causes of FHF were acute viral infection (n = 29, hepatitis A:B, 28:1), drugs (n = 18; including 4 acetaminophen and 14 herbal medication), autoimmune (n = 4), and miscellaneous (n = 2). Of the 53 patients, 19 were allocated to group 1, 18 to group 2, and 16 to group 3. According to univariate analysis, risk factors for mortality in group 2 were acute renal failure requiring renal replacement therapy and a MELD score ≥30 at the time of hepatic encephalopathy. However, by multivariate analysis, a MELD score ≥30 was the only independent risk factor for mortality in group 2 (P = .042; hazard ratio, 4.500).

CONCLUSIONS

A MELD score ≥30 was found to be the only independent risk factor of mortality in FHF patients without LT. Therefore, the findings of this study suggest that these patients may need emergent LT for survival.

Detection of microorganisms using terahertz metamaterials

Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

Comparison of the incidence between tuberculosis and nontuberculous mycobacterial disease after gastrectomy

PURPOSE

Gastrectomy is a well-known risk factor for tuberculosis (TB). However, little data are available regarding the relationship between gastrectomy and the risk of nontuberculous mycobacterial (NTM) disease. Here, we investigated the incidence of TB and NTM lung disease in gastrectomized patients.

METHOD

New cases of TB and NTM lung infection or disease were examined among patients who had undergone gastrectomy due to gastric cancer from 2003 to 2009 at a tertiary referral hospital in South Korea. Annualized incidence rates for cases were compared with those of the general population.

RESULTS

This study included a total of 2,684 patients. New mycobacterial cases were found in 41 patients. Cases of TB and NTM lung infection were 35 (85 %) and 6 (15 %) including 2 NTM lung disease cases, respectively. Annualized crude incidence rates for TB, NTM lung infection, and NTM lung disease were 327/100,000, 56/100,000, and 19/100,000, respectively. The age-standardized incidence rate of TB was significantly higher in gastrectomized patients than in the general population. However, the standardized incidences of NTM lung infection and disease were not significantly different from those of non-gastrectomized patients. Patients with NTM lung infection frequently exhibited comorbid chronic lung disease, while those with TB were more frequently found to have fibronodular lesions on preoperative chest radiography.

CONCLUSIONS

Gastrectomy does not appear to increase the risk of NTM lung disease. However, NTM lung infection or disease should be considered as a differential diagnosis of pulmonary TB in gastrectomized patients accompanying chronic lung disease.

Trends in the incidence of and survival rates for oral cavity cancer in the Korean population

OBJECTIVE

This study assessed trends in the incidence of and survival rates for oral cavity cancer in the Korean population.

MATERIALS AND METHODS

Data from the Korea Central Cancer Registry were extracted for 10,282 patients diagnosed with oral cavity cancer (C01-C06) between 1999 and 2010 to evaluate the age-standardised incidence rate, annual percentage change (APC) and 5-year relative survival rate (RSR) according to gender and age.

RESULTS

In males, the incidence rate slightly decreased [APC of -0.2% (P = 0.6427)]; in females, the incidence rate increased [APC of 3.1% (P < 0.05)]. In males and females, the incidence of oral tongue cancer (C02) significantly increased [APC of 2.2% and 4.1%, respectively (P < 0.05)]. This increase in oral tongue cancer incidence was most prominent in the younger age group (<40 years, APC = 6.1%, P < 0.05). The incidence of buccal cheek cancer increased only among males [APC of 4.8% (P < 0.05)]. The 5-year RSR improved from 42.7% (1993-1995) to 59.5% (2006-2010), corresponding to an increase of 16.8% from 1993 to 2010 (P < 0.05).

CONCLUSION

The incidence of oral cavity cancer in females increased, whereas it stabilised or decreased in males. However, the incidence of oral tongue cancer increased in both males and females, especially in the younger age group.

Association between BMP-2 and COL6A1 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the cervical spine in Korean patients and family members

COL6A1 and BMP-2 genes have been implicated in ossification of the posterior longitudinal ligament (OPLL) susceptibility in Japanese and Chinese Han populations. However, no study has yet investigated the DNA of unaffected family members of patients with OPLL. This study investigated differences in genetic polymorphisms of BMP-2 and COL6A1 between Korean patients with OPLL and their family members (with and without OPLL). A total of 321 subjects (110 patients with OPLL and 211 family members) were enrolled in the study. Associations between two single nucleotide polymorphisms (SNPs) of the BMP-2 gene (Ser37Ala and Ser87Ser) and two SNPs of COL6A1 [promoter (-572) and intron 33 (+20)] with susceptibility to OPLL of the cervical spine were investigated between the two groups (OPLL+ and OPLL-). Of the 321 subjects, 162 had cervical OPLL (50.4%; 110 patients, 52 family members). There was a familial tendency of OPLL in 34 of the 110 families (30.9%). Allele and haplotype frequencies of the four SNPs in the BMP-2 and COL6A1 genes did not differ significantly between the OPLL+ and OPLL- groups, even when excluding participants over 50 years of age. This is the first report identifying SNPs of COL6A1 and BMP-2 in Korean patients and family members with OPLL. Although allele and haplotype frequencies were similar with those of a previous study in Japanese and Chinese patients, unaffected family members also showed similar rates of these SNPs in the present study. These results suggest that these SNPs may not directly influence the expression of OPLL.

Fully solution-processed semitransparent organic solar cells with a silver nanowire cathode and a conducting polymer anode

We report the fabrication of efficient indium-tin-oxide-free organic solar cells based on poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM). All layers of the devices from the lowermost silver nanowire cathode to the uppermost conducting polymer anode are deposited from solution and processed at plastic-compatible temperatures<200 °C. Owing to the absence of an opaque metal electrode, the devices are semitransparent with potential applications in power-generating windows and tandem-cells. The measured power conversion efficiencies (PCEs) of 2.3 and 2.0% under cathode- and anode-side illumination, respectively, match previously reported PCE values for equivalent semitransparent organic solar cells using indium tin oxide.

A modified laparoscopic ureterolithotomy by pulling ureter with Carter-Thomason fascial closure and ureter incision by broken 15th blade

BACKGROUND AND AIMS

To evaluate the efficacy and safety of a modified laparoscopic ureterolithotomy for the treatment of upper ureteral stones; this method involved the use of a Carter-Thomason fascial closure device, a broken 15th blade.

MATERIAL AND METHODS

From February 2009 to December 2012, 38 patients with unilateral upper ureteral stones were examined and classified into 2 groups: one group underwent conventional laparoscopic ureterolithotomy (n = 21) and the other group underwent modified laparoscopic ureterolithotomy (n = 17). The modified laparoscopic ureterolithotomy consisted of the use of a Carter-Thomason fascial closure to extract the black silk along with the nylon tape. The ureter incision was made with a modified instrument consisting of a needle holder with a broken 15th blade tip.

RESULTS AND CONCLUSIONS

Patient demographics were similar in both groups. No significant differences were detected between the conventional laparoscopic ureterolithotomy and modified laparoscopic ureterolithotomy groups with respect to operating time, estimated blood loss, and stone clearance rates. Drain-indwelling times were significantly shorter in modified laparoscopic ureterolithotomy patients than in conventional laparoscopic ureterolithotomy patients (3.2 ± 1.3 vs 4.7 ± 1.5 days). Hospital stay was significantly lesser in modified laparoscopic ureterolithotomy patients than in conventional laparoscopic ureterolithotomy patients (4.3 ± 1.2 vs 5.2 ± 1.2 days). No differences were detected in the ureteral stent indwelling time for the two groups. The use of the Carter-Thomason fascial closure facilitated ureter handling, and the use of a needle holder with a broken 15th blade tip enabled a sharp and precise ureteral incision. Our method allows early removal of the drain and thus earlier patient discharge.

Unusual maternal uniparental isodisomic x chromosome mosaicism with asymmetric y chromosomal rearrangement

Infertile men with azoospermia commonly have associated microdeletions in the azoospermia factor (AZF) region of the Y chromosome, sex chromosome mosaicism, or sex chromosome rearrangements. In this study, we describe an unusual 46,XX and 45,X mosaicism with a rare Y chromosome rearrangement in a phenotypically normal male patient. The patient's karyotype was 46,XX[50]/45,X[25]/46,X,der(Y)(pter→q11.222::p11.2→pter)[25]. The derivative Y chromosome had a deletion at Yq11.222 and was duplicated at Yp11.2. Two copies of the SRY gene were confirmed by fluorescence in situ hybridization analysis, and complete deletion of the AZFb and AZFc regions was shown by multiplex-PCR for microdeletion analysis. Both X chromosomes of the predominant mosaic cell line (46,XX) were isodisomic and derived from the maternal gamete, as determined by examination of short tandem repeat markers. We postulate that the derivative Y chromosome might have been generated during paternal meiosis or early embryogenesis. Also, we suggest that the very rare mosaicism of isodisomic X chromosomes might be formed during maternal meiosis II or during postzygotic division derived from the 46,X,der(Y)/ 45,X lineage because of the instability of the derivative Y chromosome. To our knowledge, this is the first confirmatory study to verify the origin of a sex chromosome mosaicism with a Y chromosome rearrangement.

Interactions between ADIPOQ gene variants and dietary monounsaturated: saturated fatty acid ratio on serum lipid levels in Korean children

BACKGROUND AND AIMS

Adiponectin plays important roles in the regulation of insulin action and metabolism of glucose and lipids. We investigated whether ADIPOQ genetic variants are associated with serum lipid levels in Korean children and whether those influences might be modulated by dietary factors such as dietary monounsaturated fatty acid to saturated fatty acid ratio (MUFA:SFA).

METHOD AND RESULTS

The study included a population-based sample of 687 children aged 7-11 years in Gwacheon city, Kyunggi Province, Korea. Anthropometric and biochemical measurements and ADIPOQ genotype (-11377 C/G, +45 T/G, and +276 G/T) were determined. Dietary intake was estimated with a self reported 3-day food diary. The -11377 G allele carriers had significantly higher serum total cholesterol and LDL cholesterol compared to non-carriers. When dietary MUFA:SFA ratio was dichotomized (MUFA:SFA ≥ 1 or <1), the aggravating effects of the minor allele on serum total and LDL cholesterol were only present when the MUFA:SFA ratio was <1. Additionally, we observed that the ADIPOQ haplotype influenced serum total and LDL cholesterol levels. G-T-G haplotype carriers had higher total and LDL cholesterol levels than non-G-T-G carriers. The deleterious effect of ADIPOQ G-T-G haplotype to increase serum total and LDL cholesterol could be seen only when the MUFA:SFA ratio was <1.

CONCLUSION

In this present study, we found interaction effects between ADIPOQ genetic variants and dietary MUFA:SFA ratio on serum lipid levels in Korean children. These results suggest that individual genetic information and dietary fatty acid intake information should be assessed together to achieve an effective outcome for reducing the atherogenic lipid profile.

Decision support for ecological river rehabilitation using fish habitat database

After the recent success of several river rehabilitation projects including the Cheong-gye river case, a large number of local governments have been promoting their own projects in Korea. Most of the projects are aimed at securing the soundness of aquatic ecosystems according to the guidelines presented by the Korea Ministry of Environment. However, there is no clear guidance for the management goals of water quality and quantity. In this study, we have made an attempt to construct a habitat database (DB) for each domestic freshwater fish species. The fish population, and physical and physicochemical properties of the habitat of 70 domestic freshwater fish species were investigated using field monitoring data. After the statistical processing, the inhabitable range and optimal range of each species were suggested. Furthermore, based on the DB, a decision support system for ecological river restoration and rehabilitation has been developed, and applied for field tests. It became clear that the decision support procedure based on the fish habitat DB is useful in the planning stage of river rehabilitation projects to select the flagship fish, to decide the restoration goals considering their appropriate habitat and to suggest the optimum quantitative combination of each available water resource.

Abstract P5-07-07: Prognostic value of mutant TP53 in basal breast cancer

Backgrounds; p53 is a tumor suppressor gene that plays an important role in cell cycle control and apoptosis. In the breast cancer, mutant tumor protein (TP53) is expressed in approximately 30% and patients with mutant TP53 often tend to have poor response to chemotherapy and poor prognosis than those with normal TP53. But, according to a recent study, TP53 inactivation could cause to significant DNA damage and to eventual cell death by mitotic catastrophe. We investigated the expression frequency and prognostic value of mutant TP53 using tissue microarrays of 898 invasive breast cancers.

Patients and methods; From January 1995 to December 2005 at Yeungnam university hospital, patients who diagnosed with the primary invasive breast cancer and received operation were included in this study. Patients with bilateral breast cancer or distant metastasis at the time of diagnosis were excluded. According to the immunohistochemical results of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), Ki67, epidermal growth factor (EGFR) and cytokeratin (CK) 5/6, we classified patients into 6 subgroups, luminal A, luminal B1, B2, HER2-enriched, normal breast-like (triple negative nonbasal) and basal-like breast cancers. Immunohistochemical staining for TP53 was performed and we defined more than 10% stain of tumor cell as mutant TP53-positive. Distribution and prognostic significance of mutant TP53 in each subgroup was investigated.

Results; In 898 invasive breast cancers, mutant TP53 was identified in 33.5% (301/898). Each expression frequency of mutant TP53 was 10.9% (42/385) in luminal A, 32.1% (45/140) in luminal B1, 50.0% (34/68) in luminal B2, 63.7% (72/113) in HER2-enriched, 54.7% (35/64) in normal breast-like and 57.0% (73/128) in basal-like subtype, respectively. In whole breast cancer patients, patients with mutant TP53 tended to have poor overall survival (OS) and disease free survival (DFS). However, there was no statistical significance (p = 0.187 and p = 0.651). But, in 128 patients with basal-like breast cancer, mutant TP53 showed good prognosis in both OS and DFS (p = 0.003 and p = 0.021). In basal-like breast cancer, the expression of mutant TP53 had no association with other clinicopathologic factors such as tumor size, lymph node metastasis, histological grade, lymphovascular invasion etc. and 98.4% (126/128) patients received adjuvant chemotherapy. In multivariate anaylsis, expression of mutant TP53 was an independent prognostic factor for OS and DFS in basal-like breast cancers (p = 0.008 and p = 0.012).

Conclusions: This study showed that basal-like breast cancer with mutant TP53 has a good outcome in both OS and DFS. Further studies are needed to identify the action mechanism of mutant TP53.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-07-07.

The Hsp90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin increases cisplatin antitumor activity by inducing p53-mediated apoptosis in head and neck cancer

The tumor suppressor p53 is often inactivated in head and neck cancer (HNC) through TP53 mutations or overexpression of mouse double minute 2 or mouse double minute X. Restoration of p53 function by counteracting these p53 repressors is a promising strategy for cancer treatment. The present study assessed the ability of a heat shock protein 90 (Hsp90) inhibitor, 17-(Allylamino)-17-demethoxygeldanamycin (17AAG), to induce apoptosis in HNC by restoring p53 function. The effect of 17AAG, alone or in combination with Nutlin-3a or cisplatin, was assessed in HNC cells using growth and apoptosis, immunoblotting, quantitative reverse transcription-polymerase chain reaction, and preclinical tumor xenograft models. 17AAG activated and stabilized p53 in HNC cells bearing wild-type TP53 by disrupting the p53–MDMX interaction. 17AAG upregulated p21 and proapoptotic gene expression, and promoted apoptosis in a concentration-dependent manner. Growth inhibition by 17AAG was highest in tumor cells with MDMX overexpression. The apoptotic response was blocked by inhibition of p53 expression, demonstrating that the effect of 17AAG depended on p53 and MDMX. 17AAG synergized in vitro with Nutlin-3a and in vitro and in vivo with cisplatin to induce p53-mediated apoptosis. 17AAG effectively induced p53-mediated apoptosis in HNC cells through MDMX inhibition and increased the antitumor activity of cisplatin synergistically, suggesting a promising strategy for treating HNC.

Mitochondrial and microsatellite DNA analyses showed comparative genetic diversity between parent and offspring populations of Korean black rockfish in a hatchery facility

The black rockfish, Sebastes inermis (Sebastidae), is an important commercial fishery resource in Korea. As a preliminary investigation into the effect of artificial reproduction in a hatchery facility, the genetic divergence between parent and offspring populations of black rockfish was accessed using 10 polymorphic nuclear microsatellite DNA loci and a mitochondrial (mt) control gene. All loci that were screened showed marked polymorphisms. mtDNA control region sequences were also highly variable. Of approximately 350 base pairs (bp) sequenced, 52 variable sites, comprising 56 base substitutions, were found among 233 individuals. Offspring populations showed less genetic variability than the parent population in terms of numbers of microsatellite alleles and mtDNA haplotypes, as well as mtDNA haplotype diversity. Statistical analysis of the fixation index (ΦST and F(ST)) and analysis of molecular variance using both DNA markers showed significant genetic differences between the parent and offspring populations. These results suggest that random genetic drift and/or inbreeding events, as well as artificial selection and founder effects, occurred when the offspring strain was reproduced in a hatchery facility despite thousands of males and females from different hatcheries being maintained for artificial reproduction. Therefore, it is necessary to improve current hatchery programs by monitoring genetic variation in both the broodstock and progeny and controlling inbreeding within stocks in commercial breeding facilities to maintain the production of high-quality black rockfish. This information will be useful for determining suitable guidelines for establishing and maintaining cultured stocks and the aquaculture industry of S. inermis.

Genetic relationships of Pacific abalone (Haliotidae) species determined using universal rice primer-polymerase chain reaction fingerprinting

Random amplified polymorphic DNA (RAPD) with universal rice primers (URP) was used to identify species and to determine phylogenetic relationships for the 6 economically important Korean Pacific abalone species: Haliotis discus hannai, H. discus discus, H. madaka, H. gigantea, H. diversicolor supertexta, and H. diversicolor diversicolor, whose morphological differentiation is difficult. Of the 12 URPs used in this study, 7 were effective in producing reproducible RAPD markers for these 6 species. Amplifications with the 7 URP primers yielded 129 reproducible amplified fragments ranging between 100 and 6000 bp in length. The dendrogram generated by the unweighted pair-group method using arithmetic averages showed that the 6 species were divided into 4 groups at 0.44 similarity level, indicating that they were genetically distant from each other and had little internal phylogenetic resolution. One group included H. discus hannai, H. discus discus, H. madaka, and H. gigantea, which were divided into 2 groups at 0.52 similarity level: one group of H. discus hannai, H. discus discus, and H. madaka, and the other of H. gigantea. H. diversicolor supertexta and H. diversicolor diversicolor belonged to the other group. Furthermore, the reproducible pattern of amplified DNA bands by URP primers indicated the possibility of using these as molecular markers for the discrimination of the 6 Pacific abalone species. These results suggest that the URP-PCR approach will be a useful tool for obtaining accurate taxonomic identification and genetic relationship of Korean Pacific abalones, which is one of the first prerequisites in effective conservation programs.

Frequency downshift of Nd:YAG lasers and terahertz radiation

The interaction between an intense laser and a cotraveling relativistic dense electron beam could result in the downshifting of the laser frequency. It is theoretically analyzed that this process can generate a coherent terahertz radiation. The radiation energy could reach the order of 1 mJ per shot in the duration of 100 ps, or a temporal radiation power of 10 MW, with a set of practically relevant parameters.

Genetic characterization of Mytilus coruscus and M. galloprovincialis using microsatellite markers

Korean (hard-shelled) mussels (Mytilus coruscus) are an economically important endemic marine bivalve mollusk of Korea; yet, the population has rapidly declined because of overharvesting and habitat competition from the invasive Mytilus galloprovincialis species. The population structures of M. coruscus and M. galloprovincialis were analyzed by next-generation sequencing using 5 microsatellite markers specifically developed for M. coruscus. M. galloprovincialis had an average of 5.4 alleles per locus (range = 2-10), with an average allelic richness of 4.9 per locus (range = 2.0-9.3). M. coruscus had an average of 5.7 alleles per locus (range = 2-13), with an average allelic richness of 5.2 per locus (range = 2.0-11.9). Excessive homozygosity was observed at 3 loci, which was assumed to be due to the presence of null alleles at these loci. Pairwise multilocus FST estimates showed that the M. coruscus and M. galloprovincialis populations were clearly separated. Six populations of M. galloprovincialis from the western, eastern, and southern coast of Korea formed 2 separate clusters, indicating that more than 2 populations of M. galloprovincialis have been introduced to the Korean Peninsula. Hybrids between M. coruscus and M. galloprovincialis were not identified, probably because of genetic differences or different habitat preferences. Further genetic information is required to perform selective breeding, population management, and restoration of M. coruscus.

Development of microsatellite markers for a hard-shelled mussel, Mytilus coruscus, and cross-species transfer

The Korean mussel Mytilus coruscus, an endemic marine bivalve mollusk, is economically important. Its population is currently decreasing due to overexploitation and invasion of a more competitive species, Mytilus galloprovincialis. In this study, microsatellite markers for M. coruscus were developed using a cost-effective pyrosequencing technique. Among the 33,859 dinucleotide microsatellite sequences identified, 176 loci that contained more than 8 CA, CT, or AT repeats were selected for primer synthesis. Sixty-four (36.4%) primer sets were produced from the 100- to 200-bp polymerase chain reaction products obtained from 2 M. coruscus individuals. Twenty of these were chosen to amplify DNA from 82 M. coruscus individuals, and 18 polymorphic loci and 2 monomorphic loci were selected as microsatellite markers. The number of alleles and the allele richness of the polymorphic loci ranged from 2 to 22 and from 2.0 to 19.7 with means of 10.8 and 10.1, respectively. Null alleles were detected for all but three loci, which resulted in an observed heterozygosity lower than the expected heterozygosity and therefore an excess of homozygotes. In a cross-species transfer analysis of these markers using 7 Mytilidae species, the locus Mc65 was amplified from all species tested and was found to be polymorphic in all of them. Among the species, M. galloprovincialis, Lithophaga curta, and Hormomya mutabilis showed the same transferability of 25%, but the five amplified loci were polymorphic only in M. galloprovincialis and H. mutabilis. These microsatellite markers may be useful for future resource management and artificial production of juveniles for aquaculture.

A multicentre, multinational, randomized, placebo-controlled, double-blind, phase 3 trial to evaluate the efficacy and safety of gemigliptin (LC15-0444) in patients with type 2 diabetes

AIM

This study was designed to assess the efficacy and safety of the dipeptidyl peptidase IV inhibitor gemigliptin (LC15-0444) 50 mg versus placebo in patients with type 2 diabetes.

METHODS

We conducted a 24-week, randomized, double-blind, placebo-controlled phase III trial in 182 patients (74 from Korea and 108 from India) with type 2 diabetes. After an initial 2 weeks of a diet and exercise programme followed by 2 weeks of a single-blind placebo run-in period, eligible patients were randomized to gemigliptin 50 mg or placebo, receiving the assigned treatment for 24 weeks. HbA1c and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance test was performed at baseline and weeks 12 and 24.

RESULTS

At week 24, gemigliptin treatment led to significant reductions in HbA1c measurements compared to placebo (adjust mean after subtracting the placebo effect size: -0.71%, 95% confidence interval: -1.04 to -0.37%). A significantly greater proportion of patients achieved an HbA1c <7% with gemigliptin than with placebo. The placebo-subtracted FPG change from baseline at week 24 was -19.80 mg/dl. The overall incidence rates for adverse events were similar in the gemigliptin and placebo groups.

CONCLUSIONS

This study showed the efficacy and safety of gemigliptin 50 mg administered once daily as a monotherapy for type 2 diabetes patients.

Terahertz conductivity of reduced graphene oxide films

We performed time-domain terahertz (THz) spectroscopy on reduced graphene oxide (rGO) network films coated on quartz substrates from dispersion solutions by spraying method. The rGO network films demonstrate high conductivity of about 900 S/cm in the THz frequency range after a high temperature reduction process. The frequency-dependent conductivities and the refractive indexes of the rGO films have been obtained and analyzed with respect to the Drude free-electron model, which is characterized by large scattering rate. Finally, we demonstrate that the THz conductivities can be manipulated by controlling the reduction process, which correlates well with the DC conductivity above the percolation limit.

Mitochondrial swelling and microtubule depolymerization are associated with energy depletion in axon degeneration

Although mitochondrial dysfunction is intimately related to axonal degeneration following nerve injury, the molecular mechanisms of mitochondrial swelling and its mechanistic relation to axonal degeneration are largely unknown. Previous studies have demonstrated that axonal degeneration in the injured peripheral nerves shows two morphologically distinct phases: (1) A latency period (∼24h), in which the morphology of axonal cytoskeletons seems unchanged, followed by (2) an execution period (36-48h), which shows a catastrophic granular degeneration of most axonal structures in rodent axons. In the present study, we found that, in the sciatic nerve axotomy model, energy failure and microtubule depolymerization occurred during the latency period whereas mitochondrial swelling and neurofilament degradation started in the execution period. The energy repletion with NAD or an NAD/pyruvate mixture inhibited microtubule depolymerization, mitochondrial swelling and axonal degeneration in transected sciatic nerve axons. In addition, microtubule perturbing agents enhanced axonal degeneration and mitochondrial swelling. Extracellular calcium chelation did not affect energy failure, microtubule depolymerization or mitochondrial swelling, but it did prevent neurofilament degradation. These findings suggest that an early disturbance in energy dynamics regardless of mitochondrial swelling might be a key trigger for the initiation of axonal degeneration and that extracellular calcium influx is a late effector for neurofilament degradation.

Variation in the α 5 nicotinic acetylcholine receptor subunit gene predicts cigarette smoking intensity as a function of nicotine content

A single nucleotide polymorphism (SNP) in the α5 nicotinic acetylcholine receptor subunit gene, rs16969968, has been repeatedly associated with both smoking and respiratory health phenotypes. However, there remains considerable debate as to whether associations with lung cancer are mediated through effects on smoking behavior. Preclinical studies suggest that α5 receptor subunit expression and function may play a direct role in nicotine titration during self-administration. The present study investigated the association of CHRNA5 polymorphisms and smoking topography in 66 smokers asked to smoke 4 nicotine containing (nicotine yield = .60 mg) and 4 placebo (nicotine yield < .05 mg) cigarettes, during separate experimental sessions. Genotype at rs16969968 predicted nicotine titration, with homozygotes for the major allele (G:G) displaying significantly reduced puff volume in response to nicotine, while minor allele carriers (A:G or AA) produced equivalent puff volumes for placebo and nicotine cigarettes. The present results suggest that puff volume may be a more powerful objective phenotype of smoking behavior than self-reported cigarettes per day and nicotine dependence. Further, these results suggest that the association between rs16969968 and lung cancer may be mediated by the quantity of smoke inhaled.