An evaluation of fracture resistance of interim fixed partial denture fabricated using polymethylmethacrylate and reinforced by different fibres for its optimal placement: an in vitro study

Background

Polymethylmethacrylate (PMMA) is the most common material used to fabricate interim fixed partial denture (FPD). Several attempts have been made to improve fracture strength of this material with various methods of reinforcement, but its effect on the fracture resistance of interim FPD was not evaluated.

Method

The study was designed in two stages. In the first stage various methods of reinforcement (glass fibre, polyethylene, combination of glass and polyethylene, and stainless steel) for interim FPD of PMMA were used and its effect on the fracture resistance of interim FPD was evaluated by three point bending test using universal testing machine. In the second stage, fibres which showed the highest fracture resistance value was used to ascertain the most appropriate site of placement for reinforcing interim FPD. Comparisons were made with analysis of variance.

Results

Stainless steel and glass fibres showed significantly higher fracture resistance value than polyethylene alone or mixed with glass fibres (P < 0.001). Fibre placement in the occlusal third region of the pontic resulted in higher fracture resistance than the other locations (P < 0.05).

Conclusion

There was a definite improvement in the fracture resistance after reinforcement with fibres and stainless steel. The occlusal third region of the pontic is the most appropriate site of placement for reinforcement in interim FPD.     

Expression of co-stimulatory molecules B7-2 and PD-L1 on peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

Objective

To explore the roles of the expression of the co-stimulatory molecule, B7-2, and the co-inhibitory molecule, PD-L1, on peripheral blood mononuclear cells in the mechanism of immunotolerance in chronic hepatitis B virus infection.

Methods

Thirty HBV infected patients in the immunoreactive phase and 20 patients in the immunotolerant phase were enrolled in the study, while 20 healthy volunteers were used as controls. RT- PCR and real-time PCR methods were used to detect the expression levels of B7-2 and PD-L1 mRNA in peripheral blood mononuclear cells in chronic HBV infected patients.

Results

The B7-2 expression in immunoreactive and immunotolerant patients was significantly lower than that in the controls (P all < 0.01); B7-2 expression in immunoreactive patients was significantly lower than in immunotolerant patients (P < 0.01). PD-L1 expression in immunoreactive patients and immunotolerant patients was significantly higher than that in normal controls (P all < 0.01). The PD-L1/B7-2 ratios in immunoreactive and immunotolerant patients were significantly higher than that of the healthy controls (P all < 0.01); the PD-L1/B7-2 ratio was significantly higher in the immunoreactive patients than in the immunotolerant patients (P < 0.01).

Conclusion

In chronic HBV infection, changes in the expression of co-stimulatory and co-inhibitory molecules imply a protective adjustment against the patient's immune response that may result in increased immunotolerance and persistent HBV infection.     

BHMT gene polymorphisms as risk factors for cleft lip and cleft palate in a Chinese population

Objective Convincing evidence suggests a link between increased risk of nonsyndromic cleft lip with or without cleft palate (NSCL/P) and low intake of folic acid by the mother during pregnancy. The present study was designed to explore if genetic variation in the betaine‐homocysteine methyltransferase (BHMT) gene contributes to NSCL/P. Methods DNA was obtained from 166 individuals with NSCL/P and 285 healthy subjects. Three known single nucleotide polymorphisms (SNPs) present in the BHMT gene (rs651852, rs3...     

Cross-Topic Learning for Work Prioritization in Systematic Review Creation and Update

Objective

Machine learning systems can be an aid to experts performing systematic reviews (SRs) by automatically ranking journal articles for work-prioritization. This work investigates whether a topic-specific automated document ranking system for SRs can be improved using a hybrid approach, combining topic-specific training data with data from other SR topics.

Design

A test collection was built using annotated reference files from 24 systematic drug class reviews. A support vector machine learning algorithm was evaluated with cross-validation, using seven different fractions of topic-specific training data in combination with samples from the other 23 topics. This approach was compared to both a baseline system, which used only topic-specific training data, and to a system using only the nontopic data sampled from the remaining topics.

Measurements

Mean area under the receiver-operating curve (AUC) was used as the measure of comparison.

Results

On average, the hybrid system improved mean AUC over the baseline system by 20%, when topic-specific training data were scarce. The system performed significantly better than the baseline system at all levels of topic-specific training data. In addition, the system performed better than the nontopic system at all but the two smallest fractions of topic specific training data, and no worse than the nontopic system with these smallest amounts of topic specific training data.

Conclusions

Automated literature prioritization could be helpful in assisting experts to organize their time when performing systematic reviews. Future work will focus on extending the algorithm to use additional sources of topic-specific data, and on embedding the algorithm in an interactive system available to systematic reviewers during the literature review process.     

A Globally Optimal k-Anonymity Method for the De-Identification of Health Data

Background

Explicit patient consent requirements in privacy laws can have a negative impact on health research, leading to selection bias and reduced recruitment. Often legislative requirements to obtain consent are waived if the information collected or disclosed is de-identified.

Objective

The authors developed and empirically evaluated a new globally optimal de-identification algorithm that satisfies the k-anonymity criterion and that is suitable for health datasets.

Design

Authors compared OLA (Optimal Lattice Anonymization) empirically to three existing k-anonymity algorithms, Datafly, Samarati, and Incognito, on six public, hospital, and registry datasets for different values of k and suppression limits.

Measurement

Three information loss metrics were used for the comparison: precision, discernability metric, and non-uniform entropy. Each algorithm's performance speed was also evaluated.

Results

The Datafly and Samarati algorithms had higher information loss than OLA and Incognito; OLA was consistently faster than Incognito in finding the globally optimal de-identification solution.

Conclusions

For the de-identification of health datasets, OLA is an improvement on existing k-anonymity algorithms in terms of information loss and performance.     

Evaluation of the in vitro and in vivo genotoxicity of almond skins

Objective It aims to study potential genotoxicity of almond skins.Methods A bacterial reverse mutation assay was performed on S.typhimurium strains TA97,TA98,TA100,TA102,and TA1535 in the absence or presence of S-9 mixture at a dose range of 312.5 to 5 000 μg/plate.A micronucleus test and a mammalian bone marrow chromosome aberration tests were performed in Swiss Albino (CD-1) mice at doses of 625,1 250,and 2 500 mg/kg bw used.Results Almond skins exerted no mutagenic activity in various bacterial strains o...     

Correlation between the amplitude of glucose excursion and the oxidative/antioxidative system in subjects with different types of glucose regulation

Objective To investigate effects of glucose excursion on the oxidative/antioxidative system in subjects with different types of glucose regulation. Methods A total of 30 individuals with normal glucose regulation (NGR), 27 subjects with impaired glucose regulation (IGR) and 27 subjects with newly diagnosed type 2 diabetes mellitus (T2DM) were selected and recruited for 3 days’ continuous glucose monitor system (CGMS) assessment. The data from CGMS was used to calculate the mean amplitude of glycemic excursi...     

Comparison of Information Content of Structured and Narrative Text Data Sources on the Example of Medication Intensification

Objective

To compare information obtained from narrative and structured electronic sources using anti-hypertensive medication intensification as an example clinical issue of interest.

Design

A retrospective cohort study of 5,634 hypertensive patients with diabetes from 2000 to 2005.

Measurements

The authors determined the fraction of medication intensification events documented in both narrative and structured data in the electronic medical record. The authors analyzed the relationship between provider characteristics and concordance between intensifications in narrative and structured data. As there is no gold standard data source for medication information, the authors clinically validated medication intensification information by assessing the relationship between documented medication intensification and the patients' blood pressure in univariate and multivariate models.

Results

Overall, 5,627 (30.9%) of 18,185 medication intensification events were documented in both sources. For a medication intensification event documented in narrative notes the probability of a concordant entry in structured records increased by 11% for each study year (p < 0.0001) and decreased by 19% for each decade of provider age (p = 0.035). In a multivariate model that adjusted for patient demographics and intraphysician correlations, an increase of one medication intensification per month documented in either narrative or structured data were associated with a 5-8 mm Hg monthly decrease in systolic and 1.5-4 mm Hg decrease in diastolic blood pressure (p < 0.0001 for all).

Conclusion

Narrative and structured electronic data sources provide complementary information on anti-hypertensive medication intensification. Clinical validity of information in both sources was demonstrated by correlation with changes in blood pressure.     

Evaluation of the factorial method for determination of energy expenditure in 16 young adult women living in China

Objective The present study aimed to evaluate the accuracy of the factorial method for estimating energy needs in individuals living in China.Methods Sixteen healthy female adults aged 22.1±1.2 years with a body mass index (kg/m 2) of 20.4±1.7 were selected as subjects.In free-living conditions,energy expenditure (EE) was determined by using the factorial method.At the same time,the doubly labeled water method (DLW) was also used to measure energy expenditure of the subjects and served as the criterion meth...     

To determine the frequency of subtelomeric abnormalities in children with idiopathic mental retardation

Background

Cross-sectional study was carried out to determine the frequency of subtelomeric abnormalities in children with idiopathic mental retardation (MR).

Method

Multiplex ligation-dependant probe amplification technique was used to detect subtelomeric abnormalities.

Results

Out of 35 children, 21 (60%) were males. Family history of MR was present in 23%. Main clinical features included speech delay in all motor delay cases (83%) and non-specific dysmorphic features (77%).

Conclusion

Associated clinical features were more in children with intelligence quotient (IQ) < 50 (P < 0.05). Subtelomeric deletion (4q35) was observed in one child.     

A Randomized Trial Comparing Telemedicine Case Management with Usual Care in Older, Ethnically Diverse, Medically Underserved Patients with Diabetes Mellitus: 5 Year Results of the IDEATel Study

Context

Telemedicine is a promising but largely unproven technology for providing case management services to patients with chronic conditions and lower access to care.

Objectives

To examine the effectiveness of a telemedicine intervention to achieve clinical management goals in older, ethnically diverse, medically underserved patients with diabetes.

Design, Setting, and Patients

A randomized controlled trial was conducted, comparing telemedicine case management to usual care, with blinded outcome evaluation, in 1,665 Medicare recipients with diabetes, aged ≥ 55 years, residing in federally designated medically underserved areas of New York State.

Interventions

Home telemedicine unit with nurse case management versus usual care.

Main Outcome Measures

The primary endpoints assessed over 5 years of follow-up were hemoglobin A1c (HgbA1c), low density lipoprotein (LDL) cholesterol, and blood pressure levels.

Results

Intention-to-treat mixed models showed that telemedicine achieved net overall reductions over five years of follow-up in the primary endpoints (HgbA1c, p = 0.001; LDL, p < 0.001; systolic and diastolic blood pressure, p = 0.024; p < 0.001). Estimated differences (95% CI) in year 5 were 0.29 (0.12, 0.46)% for HgbA1c, 3.84 (−0.08, 7.77) mg/dL for LDL cholesterol, and 4.32 (1.93, 6.72) mm Hg for systolic and 2.64 (1.53, 3.74) mm Hg for diastolic blood pressure. There were 176 deaths in the intervention group and 169 in the usual care group (hazard ratio 1.01 [0.82, 1.24]).

Conclusions

Telemedicine case management resulted in net improvements in HgbA1c, LDL-cholesterol and blood pressure levels over 5 years in medically underserved Medicare beneficiaries. Mortality was not different between the groups, although power was limited.

Trial Registration

http://clinicaltrials.gov Identifier: NCT00271739.     

Using Empiric Semantic Correlation to Interpret Temporal Assertions in Clinical Texts

Objective

To measure the uncertainty of temporal assertions like “3 weeks ago” in clinical texts.

Design

Temporal assertions extracted from narrative clinical reports were compared to facts extracted from a structured clinical database for the same patients.

Measurements

The authors correlated the assertions and the facts to determine the dependence of the uncertainty of the assertions on the semantic and lexical properties of the assertions.

Results

The observed deviation between the stated duration and actual duration averaged about 20% of the stated deviation. Linear regression revealed that assertions about events further in the past tend to be more uncertain, smaller numeric values tend to be more uncertain (1 mo v. 30 d), and round numbers tend to be more uncertain (10 versus 11 yrs).

Conclusions

The authors empirically derived semantics behind statements of duration using “ago,” and verified intuitions about how numbers are used.     

Effect of Rapamycin on TGF-β1- induced epithelial-mesenchymal transition in LoVo colonic adenocarcinoma cells

Objective:To investigate the effect of Rapamycin on epithelial-mesenchyrnal transition(EMT) of LoVo colonic adenocarcinoma cells in vitro.Methods:Cultured LoVo colonic adenocarcinoma cells were divided into three groups: negative control group,EMT-inducing group(TGF-β1) and EMT-interfering group(TGF-β1 plus Rapamycin).E-cadherin expression in LoVo cells was detected by Western Blot,while the expression of vimentin was evaluated through immunocytochemistry.The Snail mRNA in LoVo cells was examined by RT-PCR.Results:TGF-β1 induced LoVo cell switching from polygonal to spindle-shaped.TGF-β1 enhanced the expression of vimentin,but lowered the level of E-cadherin.In contrast,Rapamycin impaired the transition induced by TGF-β1.Rapamycin dramatically abrogated TGF-β1-induced vimentin expression and restored E-cadherin expression in LoVo cells.Rapamycin significantly repressed the up-regulation of Snail mRNA expression induced by TGF-β1.Conclusion:Rapamycin dramatically abrogated TGF-β1 induced Snail mRNA expression in LoVo cells,hence inhibiting EMT of these cells in vitro.     

The effect of root of rhododendron on the activation of NF-κB in a chronic glomerulonephritis rat model

Objective:We have explored the role of nuclear factor kappa B(NF-κB) in the pathogenesis of chronic glomerulonephritis,and investigated the effect of rhododendron root on the activation of NF-κB.Methods:Thirty-six Wistar rats were randomly divided into three groups:a control group,a glomerulonephritis model group and a therapy group(glomerulouephritis animals treated with the root of rhododendron).Bovine serum albumin(BSA) nephritis was induced by subcutaneous immunization and daily intraperitoneal administra-tion of BSA.Twenty-four-hour urinary protein and serum creatinine values were measured,and renal pathology was assessed histologi-cally by optical microscopy and electron microscopy.NF-κB activity was determined by an electrophoretic mobility shift assay(EMSA).Results:Compared with the control rats,glomerulonephrids model rats exhibited a significant increase in both 24 h urinary protein and serum creatinine,and had abnormal renal histology.The administration of the root of rhododendron ameliorated these changes.NF-κ B activity in glomerulonephritis model group was greater than that in rhododendron-treated group,and NF-κB activity was greater in both glomerulonephritis groups than in the control group(P<0.01).Conclusion:These observations suggest that NF-κ B plays a role in the pathogenesis of chronic glomerulonephritis,and rhododendron root may attenuate renal damages by downregulating the activation of NF-kB in this model.     

Effects and its possible mechanism of Radix Saposhnikoviae on rat colonic smooth muscle in vitro

Objective: To determine the effect of different concentrations of Radix Saposhnikoviae (RS) on the contraction of smooth muscle strips and the Ca2+ mobilization of cultured smooth muscle cells of rat colon and its possible mechanism of action. Methods: Strips of rat colon longitudinal muscle were prepared and smooth muscle cells from rat colon were isolated and cultured. In the experiments, in vitro muscle strips were suspended in an organ bath and the contraction of the strips was recorded. In the cell-experiments, intracellular Ca2+ was assessed using fluorescent intensity (FI) of smooth muscle cells loaded with Fluo-4/AM, measured with a laser scanning confocal microscope and related software. Results: In the in vitro experiment, RS (0.02, 0.2, 2, 20 g/L) inhibited contraction of muscle strips in a concentration-dependent manner, and this inhibition was significant for the three higher RS concentrations (P < 0.01) for both Peak (the maximal contraction amplitude) and Area (the area under curves). Similarly, RS inhibited Ach-induced contraction. In these experiments the inhibition of the Peak values in the RS 2 and 20 g/L groups was significant (P < 0.01), as was the inhibition of the Area values in all RS groups (P < 0.05). Naloxone and propranolol did not significantly affect the inhibitory effect of RS on smooth muscle contractility, while phentolamine significantly reduced the inhibitory effect (P < 0.01). In experiments using primary smooth muscle cell cultures in Ca2+ - containing buffer, the post-treatment fluorescence of cells in the RS 0.2, 2 and 20 g/L groups differed significantly from pre-treatment values (P < 0.05), and the percent inhibition of fluorescence in the RS 2 g/L and 20 g/L groups was significant (P < 0.01). However, in Ca2+-free buffer, FS had no significant effect on cell fluorescence. Conclusion: RS inhibited both the spontaneous and Ach-stimulated contraction of rat colonic smooth muscle strips. This RS effect appeared to involve α-adrenoceptors, but not β-adrenoceptors or opioid receptors. In cultured primary smooth muscle cells, RS reduced the mobilization of Ca2+ from extracellular sources, but may had no effect on the release of Ca2+ from sarcoplasmic reticulum and endoplasmic reticulum.     

Power to Detect Spatial Disturbances under Different Levels of Geographic Aggregation

Objective

Spatio and/or temporal surveillance systems are designed to monitor the ongoing appearance of disease cases in space and time, and to detect potential disturbances in either dimension. Patient addresses are sometimes reported at some level of geographic aggregation, for example by ZIP code or census tract. While this aggregation has the advantage of protecting patient privacy, it also risks compromising statistical efficiency. This paper investigated the variation in power to detect a change in the spatial distribution in the presence of spatial aggregation.

Methods

The authors generated 400,000 spatial datasets with varying location and spread of simulated spatial disturbances, both on a purely synthetic uniform population, and on a heterogeneous population, representing hospital admissions to three community hospitals in Cape Cod, Massachusetts. The authors evaluated the power of the M-statistic to detect spatial disturbances, comparing the use of exact spatial locations versus twelve different levels of aggregation, where the M-statistic is a comparison of two distributions of interpoint distances between locations.

Results

When the spread of simulated spatial disturbances was contained to a small portion of the study region or affects a large proportion of the population at risk, power was highest when exact locations were reported. If the spatial disturbance was a more modest signal, the best power was attained at an aggregated level.

Conclusions

The precision at which patients' locations are reported has the potential to affect the power of detection significantly.     

Production and characterisation of monoclonal antibodies against 19-Nortestosterone

Objective To produce anti‐19‐Nortestosterone (NT) monoclonal antibodies and identify their immunological characteristics. Methods Hybridomas were prepared by fusing NS0 mouse myeloma cells with splenocytes isolated from immunized BALB/c mice. Noncompetitive and competitive indirect ELISA were employed to screen positive cell clones. A caprylic acid ammonium sulphate (CAAP) method was used to purify NT mAb, and the Batty saturation method was used to determine the affinity constant (Kaff). Results Five hybri...     

Auditing the Semantic Completeness of SNOMED CT Using Formal Concept Analysis

Objective

This study sought to develop and evaluate an approach for auditing the semantic completeness of the SNOMED CT contents using a formal concept analysis (FCA)-based model.

Design

We developed a model for formalizing the normal forms of SNOMED CT expressions using FCA. Anonymous nodes, identified through the analyses, were retrieved from the model for evaluation. Two quasi-Poisson regression models were developed to test whether anonymous nodes can evaluate the semantic completeness of SNOMED CT contents (Model 1), and for testing whether such completeness differs between 2 clinical domains (Model 2). The data were randomly sampled from all the contexts that could be formed in the 2 largest domains: Procedure and Clinical Finding. Case studies (n = 4) were performed on randomly selected anonymous node samples for validation.

Measurements

In Model 1, the outcome variable is the number of fully defined concepts within a context, while the explanatory variables are the number of lattice nodes and the number of anonymous nodes. In Model 2, the outcome variable is the number of anonymous nodes and the explanatory variables are the number of lattice nodes and a binary category for domain (Procedure/Clinical Finding).

Results

A total of 5,450 contexts from the 2 domains were collected for analyses. Our findings revealed that the number of anonymous nodes had a significant negative correlation with the number of fully defined concepts within a context (p < 0.001). Further, the Clinical Finding domain had fewer anonymous nodes than the Procedure domain (p < 0.001). Case studies demonstrated that the anonymous nodes are an effective index for auditing SNOMED CT.

Conclusion

The anonymous nodes retrieved from FCA-based analyses are a candidate proxy for the semantic completeness of the SNOMED CT contents. Our novel FCA-based approach can be useful for auditing the semantic completeness of SNOMED CT contents, or any large ontology, within or across domains.     

The Influence that Electronic Prescribing Has on Medication Errors and Preventable Adverse Drug Events: an Interrupted Time-series Study

Objective

This study evaluated the effect of a Computerized Physician Order Entry system with basic Clinical Decision Support (CPOE/CDSS) on the incidence of medication errors (MEs) and preventable adverse drug events (pADEs).

Design

Interrupted time-series design.

Measurements

The primary outcome measurements comprised the percentage of medication orders with one or more MEs and the percentage of patients with one or more pADEs.

Results

Pre-implementation, the mean percentage of medication orders containing at least one ME was 55%, whereas this became 17% post-implementation. The introduction of CPOE/CDSS has led to a significant immediate absolute reduction of 40.3% (95% CI: −45.13%; −35.48%) in medication orders with one or more errors.Pre-implementation, the mean percentage of admitted patients experiencing at least one pADE was 15.5%, as opposed to 7.3% post-implementation. However, this decrease could not be attributed to the introduction of CPOE/CDSS: taking into consideration the interrupted time-series design, the immediate change was not significant (−0.42%, 95% CI: −15.52%; 14.68%) because of the observed underlying negative trend during the pre-CPOE period of −4.04% [95% CI: −7.70%; −0.38%] per month.

Conclusions

This study has shown that CPOE/CDSS reduces the incidence of medication errors. However, a direct effect on actual patient harm (pADEs) was not demonstrated.