ENAM Mutations Can Cause Hypomaturation Amelogenesis Imperfecta.

Amelogenesis imperfecta (AI) is a diverse group of inherited diseases featured by various presentations of enamel malformations that are caused by disturbances at different stages of enamel formation. While hypoplastic AI suggests a thickness defect of enamel resulting from aberrations during the secretory stage of amelogenesis, hypomaturation AI indicates a deficiency of enamel mineralization and hardness established at the maturation stage. Mutations in ENAM, which encodes the largest enamel matrix protein, enamelin, have been demonstrated to cause generalized or local hypoplastic AI. Here, we characterized 2 AI families with disparate hypoplastic and hypomaturation enamel defects and identified 2 distinct indel mutations at the same location of ENAM, c588+1del and c.588+1dup. Minigene splicing assays demonstrated that they caused frameshifts and truncation of ENAM proteins, p.Asn197Ilefs*81 and p.Asn197Glufs*25, respectively. In situ hybridization of Enam on mouse mandibular incisors confirmed its restricted expression in secretory stage ameloblasts and suggested an indirect pathogenic mechanism underlying hypomaturation AI. In silico analyses indicated that these 2 truncated ENAMs might form amyloid structures and cause protein aggregation with themselves and with wild-type protein through the added aberrant region at their C-termini. Consistently, protein secretion assays demonstrated that the truncated proteins cannot be properly secreted and impede secretion of wild-type ENAM. Moreover, compared to the wild-type, overexpression of the mutant proteins significantly increased endoplasmic reticulum stress and upregulated the expression of unfolded protein response (UPR)-related genes and TNFRSF10B, a UPR-controlled proapoptotic gene. Caspase, terminal deoxynucleotidyl transferase UTP nick-end labeling (TUNEL), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays further revealed that both truncated proteins, especially p.Asn197Ilefs*81, induced cell apoptosis and decreased cell survival, suggesting that the 2 ENAM mutations cause AI through ameloblast cell pathology and death rather than through a simple loss of function. This study demonstrates that an ENAM mutation can lead to generalized hypomaturation enamel defects and suggests proteinopathy as a potential pathogenesis for ENAM-associated AI.

One gut microbiota, Fusobacterium nucleatum aggravates Neonatal necrotizing enterocolitis by induction of IRF5 expression through lncRNA ENO1-IT1/miR-22-3p axis.

OBJECTIVE: We explored the effects of Fusobacterium nucleatum (F. nucleatum) in Neonatal necrotizing enterocolitis (NEC) and its possible mechanism. MATERIALS AND METHODS: Patients with Neonatal NEC and normal healthy volunteers were collected for this study. Neonatal mice were administered with LPS and then exposed to hypoxia as a mice model of NEC. THP-1 cells were stimulated with LPS as an in vitro model of NEC. RESULTS: We have demonstrated F. nucleatum abundance correlated with patients with Neonatal NEC or mice with Neonatal NEC. Furthermore, F. nucleatum stimulated colitis and increased inflammation in mice and in vitro models. LncRNA ENO1-IT1 was an important target for F. nucleatum in NEC-inflammation. MiR-22-3p was a target gene of F. nucleatum in NEC via LncRNA ENO1-IT1. Next, IRF5 was a target gene of miR-22-3p in the function of F. nucleatum in NEC via LncRNA ENO1-IT1. Silencing IRF5 or over-expressing miR-22-3p relieved the role of lncRNA ENO1-IT1 on inflammation in NEC via CD206 and CD86 expression. CONCLUSIONS: Taken together, these results demonstrate that F. nucleatum is mechanically, biologically and clinically connected to NEC. LncRNA ENO1-IT1 may be important targets for F. nucleatum in NEC-inflammation, and a meaningful in treating patients with Neonatal NEC with elevated F. nucleatum.

Mars Methane Sources in Northwestern Gale Crater Inferred From Back Trajectory Modeling.

During its first seven years of operation, the Sample Analysis at Mars Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected seven methane spikes above a low background abundance in Gale crater. The methane spikes are likely sourced by surface emission within or around Gale crater. Here, we use inverse Lagrangian modeling techniques to identify upstream emission regions on the Martian surface for these methane spikes at an unprecedented spatial resolution. Inside Gale crater, the northwestern crater floor casts the strongest influence on the detections. Outside Gale crater, the upstream regions common to all the methane spikes extend toward the north. The contrasting results from two consecutive TLS methane measurements performed on the same sol point to an active emission site to the west or the southwest of the Curiosity rover on the northwestern crater floor. The observed spike magnitude and frequency also favor emission sites on the northwestern crater floor, unless there are fast methane removal mechanisms at work, or either the methane spikes of TLS or the non-detections of ExoMars Trace Gas Orbiter cannot be trusted.

Genetic analysis of surgical margins in oral cavity cancer.

BACKGROUND: A histological, tumour-free surgical margin does not guarantee recurrence-free survival in patients with cancer. This study investigated the association between microsatellite alteration in tumour-free surgical margins and local recurrence in patients with oral cavity squamous cell carcinoma. METHODS: Patients with histologically confirmed oral cavity squamous cell carcinoma were enrolled in this prospective study. Cancerous specimens, corresponding surgical margins and peripheral blood were obtained. Microsatellite alteration was investigated using six dinucleotide microsatellite markers. All samples were amplified by PCR, followed by automatic fragment analysis. RESULTS: Microsatellite alteration was identified in 100 specimens (69·0 per cent) from 145 patients. Among them, 85 specimens carried loss of heterozygosity, whereas 55 had microsatellite instability (MSI). Patients with MSI at the surgical margin had a higher risk of local recurrence on multivariable analysis (odds ratio 7·17, 95 per cent c.i. 3·49 to 14·73). CONCLUSION: Molecular assessment of surgical margins can help identify patients at risk of local recurrence.

Three-dimensional microstructure characterisation of thermoplastic polyolefin blends.

The size, shape and distribution of different phases in thermoplastic polyolefin (TPO) blends and composites are critical to the properties of the materials, but can be difficult to characterise. Here we report the combination of heavy metal staining and focused ion beam - scanning electron microscopy (FIB-SEM) to reveal the three-dimensional (3D) structure of an elastomer-modified poly(propylene) and a talc filled elastomer-modified poly(propylene). High-quality, high-resolution serial images were collected and the 3D structures were characterised quantitatively.

Critical behavior in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state.

Tetragonal GeNFe3 has a second-order ferromagnetic (FM) to paramagnetic transition at 76 K. Our integrated investigations indicate that the ground FM state is frustrated and the tetragonal symmetry is retained below 550 K based on the results of variable temperature X-ray diffraction. Critical behavior was analyzed by a systematic bulk magnetization study. The estimated critical exponents by three different methods (modified Arrott plot, the Kouvel-Fisher method, and critical isotherm analysis) conformably suggest that long-range magnetic coupling described by mean-field (MF) theoretical model is dominant in GeNFe3. The experimental M-T-H data collapse into two independent branches according to the scaling equations m = f±(h) with the renormalized magnetization m = ε-ßM(H, ε) and the magnetic field h = Hε-(ß+γ). The exchange distance is estimated as J(r) ∼ r-4.8 on the basis of the ß and γ values, which lies between the long-range MF model (r-4.5) and the short-range 3D Heisenberg (3DH) model (r-5). Our results indicate that the competition between local magnetic moments of iron 3d electronic state and itinerant covalent interactions of N-Fe bonds should be responsible for critical behavior in this system.

Large Positive Thermal Expansion and Small Band Gap in Double-ReO3-Type Compound NaSbF6.

Double-ReO3-type structure compound NaSbF6 undergoes a low-temperature rhombohedral to high-temperature cubic phase between 303 and 323 K, as revealed by temperature-dependent X-ray diffractions. Although many double-ReO3-type fluorides exhibit either low thermal expansion or negative thermal expansion (NTE), NaSbF6 exhibits positive thermal expansion (PTE) with a large volumetric coefficient of thermal expansion, αv = 62 ppm/K, in its cubic phase. Raman spectroscopy reveals that the low-frequency transverse vibration of fluorine atoms is stiffened in NaSbF6, compared with the typical NTE compound CaZrF6 with the same structure. The related weak contraction associated with the polyhedral rocking would be overcome by the notable elongation of the Na-F bond length on heating, thus leading to the large volumetric PTE. Unlike ScF3 and CaZrF6 which are insulators with a wide band gap, a relative small band gap of 3.76 eV was observed in NaSbF6. The small band gap can be attributed to the hybridization between the Sb 5s and F 2p orbitals.

Hidden lattice instabilities as origin of the conductive interface between insulating LaAlO3 and SrTiO3.

The metallic interface between insulating LaAlO3 and SrTiO3 opens up the field of oxide electronics. With more than a decade of researches on this heterostructure, the origin of the interfacial conductivity, however, remains unsettled. Here we resolve this long-standing puzzle by atomic-scale observation of electron-gas formation for screening hidden lattice instabilities, rejuvenated near the interface by epitaxial strain. Using atomic-resolution imaging and electron spectroscopy, the generally accepted notions of polar catastrophe and cation intermixing for the metallic interface are discounted. Instead, the conductivity onset at the critical thickness of 4-unit cell LaAlO3 on SrTiO3 substrate is accompanied with head-to-head ferroelectric-like polarizations across the interface due to strain-rejuvenated ferroelectric-like instabilities in the materials. The divergent depolarization fields of the head-to-head polarizations cast the interface into an electron reservoir, forming screening electron gas in SrTiO3 with LaAlO3 hosting complementary localized holes. The ferroelectric-like polarizations and electron-hole juxtaposition reveal the cooperative nature of metallic LaAlO3/SrTiO3.

ß-Catenin overexpression causes an increase in inflammatory cytokines and NF-κB activation in cardiomyocytes.

ß-Catenin has been implicated in various developmental and physiological processes. Defective Wnt signaling can result in different cardiac and vascular abnormalities and is activated under pathological conditions such as inflammation and obesity. In this study, roles of ß-catenin in inflammation in cardiomyocytes were investigated. 10 samples from hearts of patients with acute infarction and 10 from normal ones were collected in order to access roles of ß-catenin in cardiomyocytes. H9c2 cardiomyoblasts and primary neonatal rat cardiomyocytes were transfected with porcine cytomegalovirus (pCMV)-ß-catenin plasmid in order to overexpress ß-catenin. Protein level of ß-catenin protein was increased in human acute infarction tissues compared to ones from normal patients. The transcription factor had increased nuclear localization in cardiomyocytes of the Wistar rats with cardiac hypertension. Furthermore, expression of fibrosis protein markers increased. Protein expression of ß-catenin was increased in human acute infarction inflammatory heart tissues and in hearts of inflammatory obesity rats. After pCMV-ß-catenin plasmid was transfected in a dose-dependent manner, inflammation protein markers, TNF-α and IL-8, were upregulated in hypertensive neonatal rat cardiomyocytes and H9c2 cardiomyoblasts. In addition, overexpression of ß-catenin induced activation and nuclear localization of NF-κB. Therefore, ß-catenin is a potential molecular target for treatment of inflammation and fibrosis in cardiomyocytes.

Optimization and head-to-head comparison of MISSR-PCR, ERIC-PCR, RAPD and 16S rRNA evolutionary clock for the genotyping of Vibrio cholerae isolated in China.

PURPOSE: To establish a new genotyping method for Vibrio cholerae and compare it with other methods. MATERIALS AND METHODS: In the current study, a modified inter simple sequence repeat-polymerase chain reaction (MISSR-PCR) system was developed via several rounds of optimisation. Comparison study was then conducted between MISSR-PCR and three other methods, including enterobacterial repetitive intergenic consensus sequences-based PCR (ERIC-PCR), randomly amplified polymorphic DNA (RAPD) and 16S rRNA evolutionary clock, for the detection and genetic tracing of Vibrio cholerae isolated from seafood in China. RESULT: The results indicated that the MISSR-PCR system could generate the highest polymorphic fingerprinting map in a single round PCR and showed the best discriminatory ability for Vibrio cholerae genotyping by clearly separating toxigenic/nontoxigenic strains, local/foreign strains, and O1/O139/non-O1/non-O139 serogroup strains, comparing to ERIC-PCR, RAPD and 16S rRNA evolutionary clock. Moreover, the MISSR-PCR is superior to previously described traditional simple sequence repeat based PCR method on genotyping by more clearly separating different clusters. CONCLUSION: To the best of our knowledge, this is the first head-to-head comparison of four detection and genotyping methods for Vibrio cholerae The MISSR-PCR system established here could serve as a simple, quick, reliable and cost-effective tool for the genotyping and epidemiological study.

Practical use of povidone-iodine antiseptic in the maintenance of oral health and in the prevention and treatment of common oropharyngeal infections.

AIMS: To better inform medical practitioners on the role of antiseptics in oropharyngeal health and disease, this article focuses on povidone-iodine (PVP-I), an established and widely-available antiseptic agent. METHODOLOGY: Review of the anti-infective profile, efficacy and safety of PVP-I in managing common upper respiratory tract infections such as the common cold, influenza and tonsillo-pharyngitis, as well as oral complications resulting from cancer treatment (oral mucositis), and dental conditions (periodontitis, caries). RESULTS: Antiseptics with broad-spectrum anti-infective activity and low resistance potential offer an attractive option in both infection control and prevention. While there is some evidence of benefit of antiseptics in a variety of clinical settings that include dental and oral hygiene, dermatology, oncology, and pulmonology, there appears to be discordance between the evidence-base and practice. This is especially apparent in the management and prevention of oropharyngeal infections, for which the use of antiseptics varies considerably between clinical practices, and is in marked contrast to their dermal application, where they are extensively used as both a prophylaxis and a treatment of skin and wound infections, thus minimising the use of antibiotics. CONCLUSION: The link between oral and oropharyngeal health status and susceptibility to infection has long been recognised. The high rates of antibiotic misuse and subsequent development of bacterial resistance (e.g. increasing vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA)) in large parts of the world, especially across Asia Pacific, highlight the need for identifying alternative antimicrobials that would minimise the use of these medications. This, together with recent large-scale outbreaks of, for example, avian and swine influenza virus, further underline the importance of an increasing armamentarium for infection prevention and control.

Applying ATP bioluminescence to design and evaluate a successful new intensive care unit cleaning programme.

This was a two-phase prospective intervention study in the cardiology intensive care unit (CICU) and medical intensive care unit (MICU) and of a public 1800-bed medical centre in Taiwan. In phase I, cleaning efficacy was monitored by ATP bioluminescence after daily morning cleaning, and only 43.9% of 221 tested surfaces passed. The baseline data were used to define an intervention consisting of a new cleaning protocol as well as a new education/training programme. In phase II, following the intervention, 88.1% of 270 surfaces were found to be clean. The combined infection rate in the CICU and MICU showed a statistically significant decrease of 49.7%.

Risk factors and outcome for colistin-resistant Acinetobacter nosocomialis bacteraemia in patients without previous colistin exposure.

The clinical characteristics of patients with colistin-resistant Acinetobacter baumannii bacteraemia have been documented, but those of patients with bacteraemia caused by other Acinetobacter species remain unknown. Previous exposure to colistin has been shown to be associated with the emergence of colistin resistance, but may be not the only predisposing factor. In the current study, we highlight the risk and outcome of patients without previous exposure to colistin who acquired colistin-resistant Acinetobacter nosocomialis (ColRAN) bacteraemia. This 11-year single-centre retrospective study analysed 58 patients with ColRAN bacteraemia and 213 patients with colistin-susceptible A. nosocomialis (ColSAN) bacteraemia. Antimicrobial susceptibilities were determined with an agar dilution method. The clonal relationship of ColRAN isolates was determined with pulsed-field gel electrophoresis. A conjugation mating-out assay was conducted to delineate the potential transfer of colistin resistance genes. Multivariable analysis was performed to evaluate the risk factors for ColRAN bacteraemia. Chronic obstructive pulmonary disease (COPD) was independently associated with ColRAN bacteraemia (OR 3.04; 95% CI 1.45-6.37; p 0.003). Patients with ColRAN bacteraemia had higher APACHE II scores, but the two groups showed no significant differences in 14-day mortality (10.3% vs. 10.3%) or 28-day mortality (15.5% vs. 15.0%). ColRAN isolates had greater resistance than ColSAN isolates to all antimicrobial agents except for ciprofloxacin (0% vs. 6.6%). There were 16 different ColRAN pulsotypes, and two major clones were found. Colistin resistance did not transfer to colistin-susceptible A. baumannii or A. nosocomialis. These results show that COPD is an independent risk factor for acquisition of ColRAN bacteraemia. The mortality rates were similar between patients with ColRAN and ColSAN bacteraemia.

Clinical manifestations and prognostic factors of Morganella morganii bacteremia.

Although Morganella morganii causes a variety of clinical infections, there are limited studies on M. morganii bacteremia after the year 2000. A total of 109 patients with M. morganii bacteremia at a medical center in Taiwan from 2003 to 2012 were studied. Among them, 30.3 % had polymicrobial bacteremia and 75.2 % had community-acquired infection. The most common underlying diseases were hypertension (62.4 %) and diabetes mellitus (38.5 %). The urinary tract (41.3 %) was the major portal of entry, followed by the hepatobiliary tract (27.5 %), skin and soft tissue (21.1 %), and primary bacteremia (10.1 %). Susceptibility testing of M. morganii isolates showed ubiquitous resistance to first-generation cephalosporins and ampicillin-clavulanate; resistance rates to gentamicin, piperacillin-tazobactam, and ciprofloxacin were 30.3 %, 1.8 %, and 10.1 %, respectively. Overall, the 14-day mortality was 14.7 %. Univariate analysis revealed that elevated blood urea nitrogen (BUN) values [p = 0.0137, odds ratio (OR) 5.26], intensive care unit (ICU) admission (p = 0.011, OR 4.4), and higher Acute Physiology and Chronic Health Evaluation II (APACHE II) scores (p < 0.001, OR 1.62) were significantly associated with mortality. The APACHE II score remained the only significant risk factor for mortality in multivariate analysis (p = 0.0012, OR 1.55). In conclusion, M. morganii bacteremia patients were mostly elderly, with one or more comorbidities. Most of the patients had community-acquired infection via the urinary and hepatobiliary tracts. Furthermore, prognosis can be predicted according to disease severity measured by the APACHE II score.

Photobacterium damselae subsp. piscicida responds to antimicrobial peptides through phage-shock-protein A (PspA)-related extracytoplasmic stress response system.

AIMS: To investigate whether Photobacterium damselae subsp. piscicida (Phdp) can sense and directly respond to the presence of cationic antimicrobial peptides (AMPs). METHODS AND RESULTS: We performed proteomic methodologies to investigate the responsive proteins of Phdp on exposure to AMP Q6. Proteins significantly altered were analysed by two-dimensional gel electrophoresis (2-DE) and LC-ESI-Q-TOF MS/MS, thus resulting in five outer membrane proteins (OMPs), seven inner membrane proteins (IMPs) and 17 cytoplasmic proteins (CPs) identified. Quantitative real-time PCR was also applied to monitor the mRNA expression level of these target proteins. CONCLUSIONS: COG analysis revealed that upon exposure to AMP Q6, the majority of the upregulated proteins were involved in signal transduction mechanism, carbohydrate transport and metabolism, post-translational modification, protein turnover and chaperones, while the downregulated proteins were mainly related to energy production and conversion. Among them, phage-shock-protein A (PspA)-related stress response system was considered to play a crucial role. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this is the first report elucidating Phdp AMP-response mechanism using proteomics approach. AMP-responsive proteins identified in this study could serve as attractive targets for developing more effective antimicrobial agents against Phdp and other marine bacterial pathogens.

AdeRS combination codes differentiate the response to efflux pump inhibitors in tigecycline-resistant isolates of extensively drug-resistant Acinetobacter baumannii.

Tigecycline (TGC)-resistant extensively drug-resistant Acinetobacter baumannii (XDRAB) is an increasing threat in regard to nosocomial infections. The resistance-nodulation-cell division (RND) efflux pump has played an important role in TGC resistance. In this study, total 81 TGC-resistant XDRAB isolates were analyzed for their responses to the efflux pump inhibitor 1-(1-naphthylmethyl)-piperazine (NMP). We found that NMP could reduce by 4-fold or greater than 4-fold the minimum inhibitory concentration (MIC) of TGC in 45 isolates (55.6 %). After typing with pulsed-field gel electrophoresis (PFGE), group A appeared to be the major cluster with good synergistic response to NMP. Transcripts of the AdeABC efflux pump gene were consistently more correlated with TGC resistance than transcripts of the AdeFGJ or AdeIJK efflux pump genes in these isolates. Of the 81 isolates, the amino acid sequences of AdeR and AdeS were further classified and combined into 31 different codes. Although the dissemination of TGC-resistant XDRAB isolates was genetically diverse in our hospital, their responses to NMP conversion were still strain-dependent. We found that AdeRS combination codes were better than PFGE typing in separating groups of isolates with different sensitivity to NMP conversion.