Association of a microRNA-323b polymorphism with the persistence of hepatitis B virus infection by the enhancement of viral replication.

Recent studies have shown that some mammalian microRNAs (miRNAs) play a role in antiviral defence. However, little is known about the role of miRNA-323b in hepatitis B virus (HBV)-host interaction. We explored whether single nucleotide polymorphism (SNP) of miRNA-323b affects HBV replication in a Korean HBV cohort. Genotyping was performed in a total of 1439 subjects composed of 404 spontaneously recovered (SR) subjects as normal controls and 1035 chronic carriers (CC) of HBV who were further classified into 313 patients with chronic hepatitis, 305 patients with liver cirrhosis and 417 patients with hepatocellular carcinoma. To confirm the effect of SNP of miRNA-323b on HBV replication in vitro, HepAD38 cells were transfected with miRNA-323b wild type or miRNA-323b SNP plasmid vectors, and HBV replication was induced for 5 days. HBV DNA was isolated and quantified using real-time PCR. The polymorphism rs56103835C>T in the pre-miRNA region of miRNA-323b revealed significant minor allele frequency (0.273). rs56103835C>T SNP showed significantly affect persistence of HBV in CC group compared with SR group (OR = 1.29, P = 0.009 in a codominant model; OR = 1.29, P = 0.03 in a dominant model; and OR = 1.78, P = 0.03 in a recessive model). In vitro, the total intracellular HBV DNA content was significantly reduced by miRNA-323b wild-type plasmid vector transfection (P = 0.014). The polymorphism of miRNA-323b was significantly associated with persistence of HBV by the enhancement of HBV replication (P = 0.021). Our findings provide a novel perspective on the role SNP of miRNAs in host-virus interactions in HBV infection.

An epidemiological study of androgenic alopecia in 3114 Korean patients.

BACKGROUND: Androgenetic alopecia (AGA) is the most common type of hair loss, and is characterized by the transformation of terminal scalp hair into vellus hair. The epidemiology of AGA is not fully understood. A strong genetic basis has long been identified, although little is known of its nongenetic causes. AIM: To evaluate the association of AGA with a number of environmental factors, including smoking, drinking and sleeping habit. METHODS: In total, 3114 Korean individuals with AGA who attended any one of 17 dermatology clinics in 6 cities in South Korea between March 2011 and February 2012 were enrolled in the study. Epidemiologic a data were collected using a standard questionnaire. RESULTS: No association was seen between eating or sleeping habits and severity of hair loss. However, drinking and smoking were associated with the severity of AGA in male patients. We also found that patients of both genders with a family history had more advanced types of hair loss, and the age of onset of AGA in male patients with a family history was earlier than that in male patients without a family history. CONCLUSIONS: Although the evidence for an environmental influence on AGA remains very weak, we did find an association between hair loss severity and certain environmental factors, such as smoking and drinking. Family history with more severe hair loss and an earlier age of onset.

Computer-navigated total knee arthroplasty in haemophilic arthropathy.

Total knee arthroplasty (TKA) in end-stage haemophilic arthropathy is complex and challenging due to the altered bony anatomy, arthrofibrosis and muscle contractures. Computer navigation is especially advocated in patients with deformity or altered anatomy to improve alignment and to assist in ligament balancing. The objective of this study was to evaluate the results of computer-navigated TKA in haemophilic arthropathy. A consecutive series of computer-assisted TKA for the end-stage haemophilic arthropathy between February 2007 and December 2009 were evaluated. A total of 27 TKA were performed in 25 patients. Pre- and postoperative full-length weight-bearing radiographs were assessed for the axial limb alignment. The orientation of the components was measured on anteroposterior radiographs. Clinically, Knee Society score and Short Form-36 were evaluated. The mechanical axis of the leg was within a range of ±3° varus/valgus in 92% of the TKA. The coronal alignment of the femoral and tibial components was within a range of ±3 degrees in 96% of the knees. The clinical outcomes were significantly improved after the operation. There were no complications specific to the computer navigation. Computer-navigated TKA helps in restoring the mechanical axis and improves accuracy of orientation of the components in patients with end-stage haemophilic arthropathy. Potential benefits in long-term outcome require further investigation.

Determination of the individual atomic site contribution to the electronic structure of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA).

We have studied the element and orbital-specific electronic structure of thin films of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) using a combination of synchrotron radiation-exited resonant x-ray emission spectroscopy, x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, as well as density functional theory calculations. Resonant and non-resonant x-ray emission spectroscopies were used to measure the C and O 2p partial densities of state in PTCDA. Furthermore, resonant x-ray emission at the C and O K-edges is shown to be able to measure the partial densities of states associated with individual atomic sites. The flat molecular orientation of PTCDA on various substrates is explained in terms of the carbonyl O atom acting as a hydrogen-bond acceptor leading to multiple in-plane intermolecular C=O···H-C hydrogen bonding between carbonyl groups and the perylene core of the neighboring PTCDA molecules. We support this conclusion by comparison of our calculations to measurements of the electronic structure using element-, site-, and orbital-selective C and O K-edge resonant x-ray emission spectroscopy, and photoemission spectroscopy.

Safety of liver resection in the elderly: how important is age?

BACKGROUND: With the aging population, more elderly patients are being considered for hepatic resection. We investigated whether advanced age was associated with higher rate and severity of postoperative complications. METHODS: A total of 75 patients aged ≥70 years (group E) were matched with 75 patients aged <70 years (group Y) by the extent of liver resection and by operative indications. Primary outcome measures were rates and severity of complications. Secondary outcome measures were length of hospital stay and discharge destination. Univariate analysis was also performed to identify variables associated with higher surgical risk. RESULTS: Male-to-female ratio was 43:32 in both groups. Overall complication rates were 44 and 33.3% in group E and Y, respectively (P = 0.241; odds ratio = 1.57; 95% confidence interval [95% CI], 0.81-3.05). There was no mortality in both groups. The only postoperative age-related morbidity was confusion in the elderly. There was no difference in the rates of severe complications (grade ≥3) between group E and group Y (16 vs. 14.7%; P = 0.744; odds ratio = 1.11; 95% CI, 0.46-2.70). Median length of hospital stay were 7 and 6 days, respectively (P = 0.01). Nineteen percent and 1% of patients in group E and group Y were discharge to rehabilitation facilities, respectively (P = 0.001). Univariate analysis showed that preoperative systemic chemotherapy and longer operative time were associated with higher morbidity in the elderly. CONCLUSIONS: Liver resection can be performed in patients aged ≥70 years as safely as in younger patients. Duration and timing of systemic chemotherapy before liver resection should be optimized to minimize postoperative morbidity.

Low efficacy of entecavir therapy in adefovir-refractory hepatitis B patients with prior lamivudine resistance.

We determined the virologic response, incidence of entecavir resistance, and evolution of lamivudine and adefovir-resistant mutants during entecavir (ETV) therapy in adefovir-refractory patients with prior lamivudine resistance. Forty adefovir-refractory chronic hepatitis B patients with prior lamivudine resistance who had received entecavir for > or = 6 months were included and monitored for virologic response and entecavir resistance. Ten per cent of patients achieved HBV DNA < 50 copies/mL by PCR after 24 weeks of ETV therapy, and an initial virologic response was observed in 12 of 40 patients (30%). Higher pretreatment ALT (P = 0.039) and the presence of the rtL180M mutation (P = 0.038) were associated with an initial virologic response. During a mean follow-up of 11.4 months, four patients (10%) experienced virologic breakthrough, while ETV-resistant mutants were detected in six patients (15%). YMDD and adefovir-resistant mutants were detected in 57 and 35% of patients at baseline, respectively. At 48 weeks of therapy, 96 and 4% of patients had YMDD and adefovir-resistant mutants, respectively. These data suggest an early development of ETV resistance and low antiviral response during ETV therapy in adefovir-refractory patients with prior lamivudine resistance.

Electronic structure of N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (Cu-TFAC), from soft X-ray spectroscopies and density functional theory calculations.

The element and orbital-specific electronic structure of thin films of the organic material N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (designated as Cu-TFAC) has been studied using a combination of synchrotron radiation-excited resonant X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and density functional theory calculations. Furthermore, resonant X-ray emission at the carbon K-edge was used to measure the density of states for individual C sites in the molecule.

Gene delivery to human adult and embryonic cell-derived stem cells using biodegradable nanoparticulate polymeric vectors.

Gene delivery to stem cells holds great potential for tissue regeneration and delivery of therapeutic proteins. The major barrier is the lack of safe and efficient delivery methods. Here, we report enhanced gene delivery systems for human stem cells using biodegradable polymeric vectors. A library of poly (beta-amino esters) end-modified derivatives was developed and optimized for high transfection efficiency and low cytotoxicity for three human stem cell lines including human mesenchymal stem cells (hMSCs), human adipose-derived stem cells (hADSCs) and human embryonic stem cell-derived cells (hESCds). In the presence of 10% serum, leading end-modified C32 polymeric vectors exhibited significantly high transfection efficiency in hMSCs (27+/-2%), hADSCs (24+/-3%) and hESCds (56+/-11%), with high cell viability (87-97%) achieved in all cell types. Our results show that poly(beta-amino esters) as a class, and end-modified versions of C32 in particular, are efficient polymeric vectors for gene delivery to both adult and embryonic-derived stem cells.

Plasma ghrelin levels and their relationship with gastric emptying in patients with dysmotility-like functional dyspepsia.

BACKGROUND/AIMS: Ghrelin affects gastric motility. However, little is known about the role of ghrelin in the pathophysiology of functional dyspepsia (FD). We investigated plasma ghrelin levels and their relationship with gastric emptying time in dysmotility-like FD patients. METHODS: 42 patients with dysmotility-like FD and 14 healthy volunteers were enrolled in the study. Gastric half-emptying time was measured using a radiolabeled meal. Plasma total ghrelin levels before and after the meal were determined using a radioimmunoassay kit. RESULTS: Preprandial ghrelin levels were significantly lower in FD patients than in controls. Postprandial ghrelin levels were similar between the two groups. Abnormally low preprandial ghrelin levels were observed in 7 out of 42 patients, in whom significant postprandial decrease of ghrelin levels was absent. Delayed gastric emptying was observed in 5 out of 7 patients with abnormally low ghrelin levels. Pre- or postprandial ghrelin levels were not significantly correlated with gastric half-emptying time, both in the patient group and in the control group. CONCLUSIONS: Abnormally low preprandial ghrelin levels and absence of significant postprandial decrease of ghrelin levels are present in a subset of dysmotility-like FD patients. Further investigation on the pathogenetic implication of these alterations in FD is required.

Shh Plays an Inhibitory Role in Cusp Patterning by Regulation of Sostdc1.

Crown shapes in mammalian teeth vary considerably from species to species, and morphological characters in crown shape have been used to identify species. Cusp pattern is one of the characters in crown shape. In the processes governing the formation of cusp pattern, the Shh pathway has been implicated as an important player. Suppression of Shh signaling activity in vitro in explant assays appears to induce supernumerary cusp formation in wild-type tooth germs. However, the in vivo role of Shh signaling in cusp pattern formation and the molecular mechanisms by which Shh regulates cusp patterning are not clear. Here, through in vivo phenotypic analyses of mice in which Shh activity was suppressed and compared with wild-type mice, we characterized differences in the location, number, incidence, and shape of supernumerary cusps in molars at embryonic day 15.5. We found that the distances between cusps were reduced in molars of Shh activity-suppressed mice in vivo. These findings confirm and extend the previous idea that Shh acts as an inhibitor in the reaction-diffusion model for cusp pattern formation by negatively regulating the intercuspal distance. We uncovered a significant reduction of expression level of Sostdc1, which encodes a secreted modulator of Wnt signaling, after suppression of Shh activity. The supernumerary cusp formation in Sostdc1-/- mice and compound Sostdc1 and Lrp mutant mice indicates a strong association between Wnt and Shh signaling pathways in cusp patterning. In further support of this idea, there is a high degree of similarity in the supernumerary cusp patterns of mice lacking Sostdc1 or Shh at embryonic day 15.5. These results suggest that Shh plays an inhibitory role in cusp pattern formation by modulating Wnt signaling through the positive regulation of Sostdc1.

Genetic association between functional haplotype of collagen type III alpha 1 and chronic hepatitis B and cirrhosis in Koreans.

Collagen type III alpha 1 (COL3A1) is one of the extracelluar matrix (ECM) proteins. The expression of COL3A1 is closely related to chronic liver diseases. In this study, we investigated whether single nucleotide polymorphisms (SNPs) of COL3A1 confer genetic susceptibility to patients with hepatitis B virus-infected liver diseases including chronic hepatitis B (CH), liver cirrhosis (CIR), and hepatocellular carcinoma (HCC). A total of 399 Korean (KOR) people, 111 patients with CH, 95 patients with CIR, 86 patients with HCC, and 107 spontaneously recovery, were genotyped for 16 SNPs of the COL3A1 gene. The 'A' allele of rs3106796 was highly associated with the CH [odds ratio (OR) = 1.62, P = 0.01], CIR (OR = 1.67, P = 0.01), and HCC (OR = 1.59, P = 0.03). There were six polymorphic SNPs that could be divided into two linkage disequilibrium (LD) blocks. The haplotype pattern of the KOR control seems to be similar to the patterns displayed in the Japanese, Chinese, and Caucasian populations sampled in the International HapMap project. Haplotype 3 (A-G-A) of the LD block 2 was significantly associated with CH (OR = 2.23, P = 0.02), CIR (OR = 2.24, P = 0.03), and HCC (OR = 2.27, P = 0.03). Moreover, diplotype analysis showed that they had increased relative risk for CH and CIR in the two diplotypes, dt3 (A-G-A/G-G-A; OR = 4.05, P = 0.01) and dt6 (A-A-A/A-G-A; OR = 7.42, P = 0.01 and OR = 5.84, P = 0.05) against dt1 (G-G-A/G-G-A), the most common diplotype in both KOR groups. In vitro reporter gene assays showed that the constructs containing the 'G' allele of rs3106796 appear to exert lower transcriptional activity of COL3A1 than the 'A' allele, depending on the promoter types.

Growth effects of botulinum toxin type A injected into masseter muscle on a developing rat mandible.

OBJECTIVES: Botulinum toxin type A (BTX-A) reduces the muscular contractions by temporarily inhibiting the release of acetylcholine at the neuromuscular junction. The purpose of this study was to investigate the effects of the BTX-A injected into the masseter muscle of a developing rat mandible. MATERIALS AND METHODS: Four-week-old male (no. 80) Sprague-Dawley rats were divided into four groups: control group, saline group, BTX-A group and baseline control group. Rats of baseline group were sacrificed at 0 day to provide baseline values of the mandibular measurements. The masseter muscle of rats in the saline and the BTX-A group were administered with saline and BTX-A solutions respectively. Experimental animals were sacrificed after 4 weeks. RESULTS: The BTX-A group demonstrated smaller mandibular dimension compared with the other groups (P < 0.05). Their condylar cartilages showed increased apoptosis at the proliferation stage of the reserve zone and masseter muscle fibers demonstrated atrophic changes. CONCLUSIONS: The result demonstrated BTX-A influence on inhibitory action of the developing mandible because of apoptosis at the proliferation stage of the reserve zone of the condylar cartilage in developing rat mandible.

Upstream Enhancer Elements of Shh Regulate Oral and Dental Patterning.

Sonic hedgehog ( Shh) is important in pattern formation during development. Shh transcription is modulated by a long-range regulatory mechanism containing a number of enhancers, which are spread over nearly 850 kb in the mouse genome. Shh enhancers in the nervous system have been found between intron and 430 kb upstream of Shh. Enhancers in the oral cavity, pharynx, lung, gut, and limbs have been discovered between 610 kb and 850 kb upstream of Shh. However, the intergenic region ranging from 430 to 610 kb upstream of Shh remains to be elucidated. In the present study, we found a novel long-range enhancer located 558 kb upstream of Shh. The enhancer showed in vivo activity in oral cavity and whiskers. A targeted deletion from the novel enhancer to mammal reptile conserved sequence 1 (MRCS1), which is a known enhancer of Shh in oral cavity, resulted in supernumerary molar formation, confirming the essential role of this intergenic region for Shh transcription in teeth. Furthermore, we clarified the binding of Lef1/Tcfs to the new enhancer and MRCS1, suggesting that Wnt/ß-catenin signaling regulates Shh signaling in the oral cavity via these enhancers.

Inhibition of apoptosis in early tooth development alters tooth shape and size.

Apoptosis plays important roles in various stages of organogenesis. In this study, we hypothesized that apoptosis would play an important role in tooth morphogenesis. We examined the role of apoptosis in early tooth development by using a caspase inhibitor, z-VAD-fmk, concomitant with in vitro organ culture and tooth germ transplantation into the kidney capsule. Inhibition of apoptosis at the early cap stage did not disrupt the cell proliferation level when compared with controls. However, the macroscopic morphology of mice molar teeth exhibited dramatic alterations after the inhibition of apoptosis. Crown height was reduced, and mesiodistal diameter was increased in a concentration-dependent manner with z-VAD-fmk treatment. Overall, apoptosis in the enamel knot would be necessary for the proper formation of molar teeth, including appropriate shape and size.

The X-ray structure of Aspergillus aculeatus polygalacturonase and a modeled structure of the polygalacturonase-octagalacturonate complex.

Polygalacturonases hydrolyze the alpha-(1-4) glycosidic bonds of de-esterified pectate in the smooth region of the plant cell wall. Crystal structures of polygalacturonase from Aspergillus aculeatus were determined at pH 4.5 and 8.5 both to 2.0 A resolution. A. aculeatus polygalacturonase is a glycoprotein with one N and ten O-glycosylation sites and folds into a right-handed parallel beta-helix. The structures of the three independent molecules are essentially the same, showing no dependency on pH or crystal packing, and are very similar to that of Aspergillus niger polygalacturonase. However, the structures of the long T1 loop containing a catalytic tyrosine residue are significantly different in the two proteins. A three-dimensional model showing the substrate binding mode for a family 28 hydrolase was obtained by a combined approach of flexible docking, molecular dynamics simulations, and energy minimization. The octagalacturonate substrate was modeled as an unbent irregular helix with the -1 ring in a half-chair ((4)H(3)) form that approaches the transition state conformation. A comparative modeling of the three polygalacturonases with known structure shows that six subsites ranging from -4 to +2 are clearly defined but subsites -5 and +3 may or may not be shaped depending on the nearby amino acid residues. Both distal subsites are mostly exposed to the solvent region and have weak binding affinity even if they exist. The complex model provides a clear explanation for the functions, either in catalysis or in substrate binding, of all conserved amino acid residues in the polygalacturonase family of proteins. Modeling suggests that the role of the conserved Asn157 and Tyr270, which had previously been unidentified, may be in transition state stabilization. In A. niger polygalacturonase, the long T1 loop may have to undergo conformational change upon binding of the substrate to bring the tyrosine residue close to subsite -1.

Gabapentin reduces rectal mechanosensitivity and increases rectal compliance in patients with diarrhoea-predominant irritable bowel syndrome.

BACKGROUND: Gabapentin has been shown to reduce elements of central sensitization in human experimental hyperalgesia. It remains uninvestigated whether gabapentin has beneficial effects for irritable bowel syndrome associated with visceral hypersensitivity. AIMS: To evaluate the effects of gabapentin on sensory and motor function of the rectum in patients with diarrhoea-predominant irritable bowel syndrome. METHODS: Forty patients with diarrhoea-predominant irritable bowel syndrome completed this randomized, double-blind, placebo-controlled, parallel-grouped study. All patients received a barostat study and were subsequently randomized for 5-day treatment with gabapentin 300 mg/day and then 600 mg/day or placebo. On day 6, after subjects had their morning dose, the barostat experiment was repeated. RESULTS: The threshold pressures for bloating, discomfort and pain significantly increased after gabapentin, but not after placebo. Significant increase in the pressure and corresponding wall tension inducing discomfort or pain were observed in the gabapentin group, but not in the placebo group. Rectal compliance significantly increased after gabapentin, but not after placebo. The postprandial increase of rectal tone was not affected by gabapentin. CONCLUSION: Our results show that gabapentin reduces rectal sensory thresholds through attenuating rectal sensitivity to distension and enhancing rectal compliance in diarrhoea-predominant irritable bowel syndrome patients. The clinical efficacy of this drug in irritable bowel syndrome patients warrants investigation.

Antioxidative effects of ethyl 2-(3-(benzo[d]thiazol-2-yl)ureido)acetate against amyloid ß-induced oxidative cell death via NF-κB, GSK-3ß and ß-catenin signaling pathways in cultured cortical neurons.

We have previously shown that 2-(3-(benzo[d]thiazol-2-yl)ureido)acetate (KHG21834) attenuates amyloid beta(Aß)25-35-induced apoptotic death and shows anti-inflammatory activity against Aß25-35-induced microglial activation. However, antioxidative effects of KHG21834 against Aß-induced oxidative stress have not yet been reported. In the present study, we investigated the antioxidative function of KHG21834 in primary cultured cortical neurons, to expand the potential therapeutic efficacy of KHG21834. Pretreatment with KHG21834 protected against Aß-induced neuronal cell death and mitochondrial damage, and significantly restored GSH levels and the activities of catalase, superoxide dismutase, and glutathione peroxidase, and also suppressed the production of reactive oxygen species and protein oxidation. These results imply that KHG21834 may play a role in cellular defense mechanisms against Aß-induced oxidative stress in cultured cortical neurons. Furthermore, KHG21834 significantly attenuated the effects of Aß treatment on levels of NF-κB, ß-catenin, and GSK-3ß proteins in cortical neurons. Taken together, our results suggest that the antioxidant effects of KHG21834 may result at least in part from its ability to regulate the NF-κB, ß-catenin, and GSK-3ß signaling pathways. To our knowledge, this is the first report showing that KHG21834 significantly attenuates Aß25-35-induced oxidative stress in primary cortical neurons, and provides novel insights into KHG21834 as a possible therapeutic agent for the treatment of Aß-mediated neurotoxicity involving oxidative stress.

Activation of two types of brain glutamate dehydrogenase isoproteins by gabapentin.

The stimulatory effects of gabapentin on the activities of two types of glutamate dehydrogenase (GDH) isoproteins homogeneously purified from bovine brain have been studied at various conditions. When the effects of different gabapentin concentrations on GDH activities were studied in the direction of reductive amination of 2-oxoglutarate with NADPH as a coenzyme, a marked activation was observed for both isoproteins, whereas both isoproteins showed activation to a lesser extent with NADH as a coenzyme. Stimulatory effects of gabapentin on GDH activities in the direction of the oxidative deamination of glutamate were also observed, but to a much lesser extent than reductive amination. There were big differences between the two GDH isoproteins in their sensitivity to the action of gabapentin. The largest activation was observed with GDH II when NADPH was used as a coenzyme. Half-maximal stimulation was reached at around 1.5 mM. Gabapentin relieved the inhibition of GDH isoproteins by GTP and this resulted in an increase in the apparent activation by gabapentin in the presence of GTP. 2-Oxoglutarate was found to give rise to high substrate inhibition and gabapentin reduced the substrate inhibition in the presence of 0.2 mM NADH. Since there are neurodegenerative disorders in which GDH activity is decreased, the therapeutic modulation of the activity of this enzyme may be clinically useful.

Inactivation of an NADPH-dependent succinic semialdehyde reductase by o-phthalaldehyde.

Incubation of an NADPH-dependent succinic semi-aldehyde reductase from bovine brain with o-phthalaldehyde resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo first-order kinetics with the second-order rate constant of 28 M(-1) s(-1). The inactivation was prevented by preincubation of the enzymes with NADPH, but not by succinic semialdehyde. There was a linear relationship between isoindole formation and the loss of enzyme activity. Spectrophotometric studies indicated that complete inactivation of the enzyme resulted from the formation of one isoindole derivative per molecule of enzyme, which was formed from the reaction of cysteine and lysine residues with o-phthalaldehyde at or near the enzyme active site.