Abstract Statement of problem Limited evidence is available for the marginal and internal fit of fixed dental restorations fabricated with digital impressions compared with those fabricated with ...conventional impressions. Purpose The purpose of this systematic review was to compare marginal and internal fit of fixed dental restorations fabricated with digital techniques to those fabricated using conventional impression techniques and to determine the effect of different variables on the accuracy of fit. Material and methods Medline, Cochrane, and EMBASE databases were electronically searched and enriched by hand searches. Studies evaluating the fit of fixed dental restorations fabricated with digital and conventional impression techniques were identified. Pooled data were statistically analyzed, and factors affecting the accuracy of fit were identified, and their impact on accuracy of fit outcomes were assessed. Results Dental restorations fabricated with digital impression techniques exhibited similar marginal misfit to those fabricated with conventional impression techniques (P>.05). Both marginal and internal gaps were greater for stone die casts, whereas digital dies produced restorations with the smallest gaps ( P <.05). When a digital impression was used to generate stereolithographic (SLA)/polyurethane dies, misfit values were intermediate. The fabrication technique, the type of restoration, and the impression material had no effect on misfit values ( P >.05), whereas die and restoration materials were statistically associated ( P <.05). Conclusions Although conclusions were based mainly on in vitro studies, the digital impression technique provided better marginal and internal fit of fixed restorations than conventional techniques did.
Avian influenza A H6N1 virus is one of the most common viruses isolated from wild and domestic avian species, but human infection with this virus has not been previously reported. We report the ...clinical presentation, contact, and environmental investigations of a patient infected with this virus, and assess the origin and genetic characteristics of the isolated virus.
A 20-year-old woman with an influenza-like illness presented to a hospital with shortness of breath in May, 2013. An unsubtyped influenza A virus was isolated from her throat-swab specimen and was transferred to the Taiwan Centres for Disease Control (CDC) for identification. The medical records were reviewed to assess the clinical presentation. We did a contact and environmental investigation and collected clinical specimens from the case and symptomatic contacts to test for influenza virus. The genomic sequences of the isolated virus were determined and characterised.
The unsubtyped influenza A virus was identified as the H6N1 subtype, based on sequences of the genes encoding haemagglutinin and neuraminidase. The source of infection was not established. Sequence analyses showed that this human isolate was highly homologous to chicken H6N1 viruses in Taiwan and had been generated through interclade reassortment. Notably, the virus had a G228S substitution in the haemagglutinin protein that might increase its affinity for the human α2-6 linked sialic acid receptor.
This is the first report of human infection with a wild avian influenza A H6N1 virus. A unique clade of H6N1 viruses with a G228S substitution of haemagglutinin have circulated persistently in poultry in Taiwan. These viruses continue to evolve and accumulate changes, increasing the potential risk of human-to-human transmission. Our report highlights the continuous need for preparedness for a pandemic of unpredictable and complex avian influenza.
Taiwan Centres for Disease Control.
Background Noninvasive direct flow measurement from digital subtraction angiography (DSA) is challenging in brain arteriovenous malformations (BAVMs). We devised a method to estimate the blood volume ...flow rate of BAVM nidus using DSA, and assessed its association with angioarchitecture features in hemorrhagic presentation. Methods A total of 24 patients with BAVMs (10 controls and 14 with hemorrhage) who underwent DSA and magnetic resonance (MR) were retrospectively recruited. Fifteen patients underwent additional phase contrast MR imaging. The nidus volume was contoured on the MR time‐of‐flight data set. From DSA, flow velocities and volume flow rate were estimated along calibrated vascular center lines. The BAVM nidus volume flow rate was computed by adding feeding volume flow rate of arteries confirmed on DSA and then normalizing them with nidus volume to yield the nidus flow index. The correspondent phase‐contrast MR‐estimated nidus flow index was evaluated in each BAVM for comparison. Comparisons of hemodynamic parameters of the control and hemorrhage groups were conducted using the Wilcoxon rank sum test. A support vector machine was used for classifying BAVM patients using angioarchitectures and the nidus flow index. Results For the DSA results, the nidus flow index was higher in the hemorrhagic group than in the control group ( P =0.0272). The flow index determined using phase‐contrast MR and nidus volume were not significant. The classification accuracy was higher when the DSA nidus flow index was added into angioarchitecture. Conclusion The BAVM nidus flow index can be directly estimated from DSA and may be associated with hemorrhagic BAVM. Peritherapeutic hemodynamic assessment of BAVMs inside the angio‐suite is feasible.
Objective
Artificial intelligence (AI) prediction is increasingly used for decision making in health care, but its application for adverse outcomes in emergency department (ED) patients with acute ...pancreatitis (AP) is not well understood. This study aimed to clarify this aspect.
Methods
Data from 8274 ED patients with AP in three hospitals from 2009 to 2018 were analyzed. Demographic data, comorbidities, laboratory results, and adverse outcomes were included. Six algorithms were evaluated, and the one with the highest area under the curve (AUC) was implemented into the hospital information system (HIS) for real‐time prediction. Predictive accuracy was compared between the AI model and Bedside Index for Severity in Acute Pancreatitis (BISAP).
Results
The mean ± SD age was 56.1 ± 16.7 years, with 67.7% being male. The AI model was successfully implemented in the HIS, with Light Gradient Boosting Machine (LightGBM) showing the highest AUC for sepsis (AUC 0.961) and intensive care unit (ICU) admission (AUC 0.973), and eXtreme Gradient Boosting (XGBoost) showing the highest AUC for mortality (AUC 0.975). Compared to BISAP, the AI model had superior AUC for sepsis (BISAP 0.785), ICU admission (BISAP 0.778), and mortality (BISAP 0.817).
Conclusions
The first real‐time AI prediction model implemented in the HIS for predicting adverse outcomes in ED patients with AP shows favorable initial results. However, further external validation is needed to ensure its reliability and accuracy.
Summary Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a predominantly extranodal lymphoma associated with Epstein-Barr virus occurring most frequently in the upper aerodigestive ...tract. There are limited reports on cellular origin and prognostic factors. We retrospectively investigated 73 cases with a median age of 54 years and a male-female ratio of 2.0:1. The upper aerodigestive tract (nasal group) was the most common site of involvement (51 cases; 70%). The other organs (n = 22; extranasal group) included the skin (12 cases; 16%) and gastrointestinal tract (5; 7%). Of the 70 cases with complete staging, 71% had stage I/II disease. All cases were positive for Epstein-Barr virus by in situ hybridization. Using immunohistochemistry and clonality assay for T-cell receptor gene rearrangement, these tumors were classified into NK (n = 39; 53%), T (n = 13; 18%), and indeterminate lineage (n = 21; 29%). The only clinicopathological difference among these 3 groups was rare CD5 expression in the NK-cell group. Nasal tumors were more frequently of NK-cell origin, and extranasal tumors were equally of either T- or NK-cell origin. The 5-year overall survival rate was 35.6%. The overall survival time was shorter in the extranasal group, although there was no statistical difference in age, sex, and histologic or immunophenotypic features between the 2 groups. Excluding the cases with indeterminate lineage, 75% of cases were of NK lineage; and 25%, T lineage. Extranasal tumors were more aggressive than their nasal counterparts. A prospective national study is warranted for a better understanding of the clinicopathological and genetic features of this uncommon tumor and the prognostic factors.
A large fraction of the p53 mutations in lung cancers from smokers are G-to-T transversions, a type of mutation that is infrequent in lung cancers from nonsmokers and in most other tumors. Previous ...studies have indicated that there is an association between G-to-T transversion hotspots in lung cancers and sites of preferential formation of polycyclic aromatic hydrocarbon adducts along the p53 gene. p53 codons containing methylated CpG sequences are preferential targets for formation of adducts by (+/-) anti-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzoapyrene (BPDE). To assess the role of CpG methylation in induction of mutations by BPDE, we analyzed BPDE mutagenesis in three CpG methylated target genes: a supF shuttle vector and the cII and lacI transgenes in embryonic mouse fibroblasts. After methylation of the shuttle vector at all CpG sequences, 42% of all G-to-T transversions were at CpG sites compared with 23% in unmethylated DNA. In the cII transgene, which is methylated at CpG sequences in vivo, 83 of 147 (56%) of the BPDE-induced mutations were G-to-T transversions, and 58% (48 of 83) of all G-to-T transversions occurred at methylated CpG sequences. In the lacI gene, 68% (75 of 111) of the BPDE-induced mutations were G-to-T events, and 58 of 75 (77%) of these occurred at methylated CpG sequences. The occurrence of transversion hotspots at methylated CpGs correlated with high levels of BPDE adducts formed at such sites. This situation mirrors the one in the p53 gene in lung cancers from smokers where 236 of 465 (51%) of the G-to-T transversions occurred at methylated CpG sites. These findings further strengthen a link between polycyclic aromatic hydrocarbons present in cigarette smoke and lung cancer mutations and provide evidence that mutational processes other than C-to-T transition mutations can occur selectively at methylated CpG sequences.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental carcinogens. PAHs are classified into bay and fjord region compounds according to structural differences in the molecule region ...where enzymatic epoxidation occurs. Dibenzoa,lpyrene (DBa,lP), one of the fjord region compounds, has been demonstrated to be the most carcinogenic PAH known to date. DBa,lP is activated to fjord region (+)-syn and (-)-anti-11,12-dihydroxy-13,14-epoxy-11,12,13,14-tetrahydrodibenzoa,lpyrene (DBa,lPDE) metabolites. In this study, we analyzed mutagenesis induced by (+)-syn- and (-)-anti-DBa,lPDE at the cII transgene in Big-Blue mouse cells. The mutant frequency of untreated cells (background level) was 6.53 x 10(-5). This level increased 3.7-fold for 20 nmol/L, 5.3-fold for 50 nmol/L, and 7.9-fold for 100 nmol/L (+)-syn-DBa,lPDE, respectively. In the case of (-)-anti-DBa,lPDE it increased 4.5-fold for 20 nmol/L, 6.7-fold for 50 nmol/L, and 10.6-fold for 100 nmol/L, respectively, indicating that (-)-anti-DBa,lPDE is slightly more mutagenic than (+)-syn-DBa,lPDE. The mutational spectra of (+)-syn- and (-)-anti-DBa,lPDE were quite similar except for several hotspots, specific for either (+)-syn-DBa,lPDE or (-)-anti-DBa,lPDE. The most frequently induced mutations were A to T transversions, which were 43.9% for (+)-syn- and 38.8% for (-)-anti-DBa,lPDE. In addition, G to T transversions were induced significantly, at frequencies of 18.5% by (+)-syn- and 18.1% by (-)-anti-DBa,lPDE. Using UvrABC cleavage and ligation-mediated PCR or the terminal transferase-dependent PCR method, we have determined DBa,lPDE-DNA adduct formation sites and repair rates in carcinogen-exposed cells. The mutation hotspots coincided with sites of strong adduct formation, but not all of the adduct hotspots were mutational hotspots. Slow adduct removal occurred for both (+)-syn- and (-)-anti-DBa,lPDE adducts over a time period of up to 72 hours. The data suggest that, although the (-)-anti-isomer is slightly more mutagenic, DNA adducts of both DBa,lPDE stereoisomers may have similar biological properties. We discuss the implications of these findings for human cancer mutagenesis.
Community-based seroepidemiologic studies were conducted to monitor the effectiveness of measles immunization programmes and to estimate the decay rate of vaccine-induced measles IgG titres. Sera ...collected from a mountain (792 sera), rural (875 sera) and urban (894 sera) populations in 1995–1997 were available. Measles IgG was quantified using a commercial EIA kit. Measles IgG seroprevalence and geometric mean titre (GMT) were calculated by setting the cut-off titre at 50 mIU/ml. The decay rate of measles IgG titres was estimated by assuming that the measles IgG titres, without exposing to wild measles virus, decay exponentially and constantly after 1 year post vaccination. The half-life of measles IgG titres was calculated from the corresponding decay rate. Measles IgG seroprevalences in these three populations have reached >95% in school children (7–18 years old) and >98% in young adults (19–25 years old) but varied from 87 to 96% in pre-school children (4–6 years old). Two-dose vaccinees, comparing with 1-dose vaccinees, had a significantly higher seroprevalence (98 versus 92%,
P<0.01) and a slightly longer half-life of measles IgG titres (61 versus 27 months,
P=0.08) but the measles IgG GMT in the two groups did not differ significantly (675 versus 618 mIU/ml,
P=0.78).
Microwaves in the asia-pacific region Yamashita, E.; Bird, T.S.; Zhenghe Feng ...
IEEE transactions on microwave theory and techniques,
03/2002, Volume:
50, Issue:
3
Journal Article
Peer reviewed
Infrastructure elements to produce microwave engineers and to promote microwave research and development in the Asia-Pacific region are described by active professors and researchers in this area as ...a multiauthor forum. The content of each description focuses mainly on the role of present-day universities, government, and industry.
A national vaccination program against hepatitis B virus (HBV) to immunize every newborn was initiated in Taiwan in 1986. A serologic survey of 1,812 fully vaccinated children residing in four ...aboriginal villages and four adjacent nonaboriginal Han Chinese rural villages was conducted in 1993. Children in three of the four aboriginal villages had significantly lower titers of antibody against hepatitis B surface antigen (anti-HBs) than did children in the nonaboriginal villages. Evaluation of cold chain operation for vaccine storage and transport suggested that cold chain failure was not responsible for the fact that children residing in the more remote aboriginal villages had lower mean trters of anti-HBs. However, children whose parents were both aborigines had lower anti-HBs mean titer than did children whose parents were both ethnic Han Chinese. Children of mixed parental origins had intermediate mean titer of anti-HBs. Serologic responses to Japanese encephalitis virus and diphtheria vaccines did not show such correlation with ethnic groups, indicating that the determinant for HBV hyporesponsiveness among the aboriginal children is distinct from that of other childhood vaccines. It was therefore concluded that host factors pertaining to ethnic origin might be responsible for the hyporesponsiveness to HBV vaccine in the aboriginal populations. This finding, if substantiated with further prospective studies, might provide possible means for more targeted trials to improve vaccine response and to reduce vaccine failure among these well-defined ethnic groups.
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