Evaluation of genotoxicity of Trois through Ames and in vitro chromosomal aberration tests

Objective

To investigate the mutagenic potential of Trois using the bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test.

Methods

The ability of Trois to induce reverse mutations was evaluated in Salmonella typhimurium (TA 98, TA100, TA1535 and TA1537) and Escherichia coli (WP2 uvrA) with and without metabolic activation system (S9 mix) at the dose range of 313 to 5000 µg/plate. Chromosomal aberrations were evaluated in Chinese hamster lung (CHL) cell line at the dose levels of 15, 7.5, 3.7, 1.9 and 0.9 mg/mL in the absence and presence of S9 mix.

Results

There were no increases in the number of revertant colonies at any concentrations of Trois used in the study with and without S9 mix in all tester strains. Trois did not produce any structural aberration in CHL cells in the presence or absence of S9 mix.

Conclusions

Results of this study suggest that Trois is non-mutagenic.     

Validation of Knowledge Acquisition for Surgical Process Models

Objective

Surgical Process Models (SPMs) are models of surgical interventions. The objectives of this study are to validate acquisition methods for Surgical Process Models and to assess the performance of different observer populations.

Design

The study examined 180 SPM of simulated Functional Endoscopic Sinus Surgeries (FESS), recorded with observation software. About 150,000 single measurements in total were analyzed.

Measurements

Validation metrics were used for assessing the granularity, content accuracy, and temporal accuracy of structures of SPMs.

Results

Differences between live observations and video observations are not statistically significant. Observations performed by subjects with medical backgrounds gave better results than observations performed by subjects with technical backgrounds. Granularity was reconstructed correctly by 90%, content by 91%, and the mean temporal accuracy was 1.8 s.

Conclusion

The study shows the validity of video as well as live observations for modeling Surgical Process Models. For routine use, the authors recommend live observations due to their flexibility and effectiveness. If high precision is needed or the SPM parameters are altered during the study, video observations are the preferable approach.     

Gene expression changes in the pituitary gland of rats exposed to electromagnetic pulses

Objective We examined alterations in the expression of tumorigenesis‐related genes in the pituitary gland of rats exposed to electromagnetic pulses (EMP).Methods The global gene expression profiles of the pituitary gland in EMP‐exposed and control groups were detected by cDNA microarray analysis.We then validated and further investigated the reduced expression of two tumorigenesis‐related genes,Pten,and Jund,by assessing their mRNA and protein expression by quantitative real‐time‐PCR,western blotting,and im...     

Milk consumption and lactose intolerance in adults

Objective To investigate relations between milk consumption and lactose intolerance (LI) in adults and to explore the effect of milk consumption on lactase activity.Methods Total of 182 subjects aged 20‐70 years were recruited and interviewed by questionnaires,and their accumulative cow's milk intake (AMI) was calculated.LI was evaluated by hydrogen breath test (HBT).Results A negative correlation was found between AMI and severity of observed LI symptom (r=-0.2884;P<0.05).Binary logistic regression analysi...     

Extended-spectrum β-lactamase-producing enterobacteriaceae causing nosocomial infections in Mexico. A retrospective and multicenter study

Background and Aims

Extended-spectrum β-lactamase (ESBLs) production is still the most frequent mechanism of resistance to cephalosporins in gram-negative bacteria. The aim of the study was to identify the types of ESBL-producing Enterobacteriaceae clinical isolates causing nosocomial infections in Mexico.

Methods

ESBL production was performed using a disk diffusion method. The MIC for several antibiotics was performed by agar dilution on Mueller-Hinton. PFGE typing was carried out on all enterobacteria assayed. The β-lactamase pattern was obtained by IEF and bioassay. Genes of β-lactamases were amplified by PCR with specific primers and products were sequenced and analyzed using informatics programs. Plasmid isolation and conjugation experiments were carried out using standard methodologies.

Results

There were 134 isolates of Enterobacteriaceae included from a retrospective and multicenter study that included eight Mexican hospitals from 1999 to 2005. The most prevalent species were K. pneumoniae (56%), Enterobacter cloacae (29%), and Escherichia coli (15%). Molecular analysis identified the underlying endemic and polyclonal spread of enterobacterials in each hospital. The most frequent ESBLs identified were SHV-type (84%), TLA-1 (11%), and CTX-M-15 (5%). Successful matings were detected in 68.4% (71/104) isolates.

Conclusions

ESBL-producer K. pneumoniae remains the most frequent bacterial species obtained in nosocomial infections. The SHV-type and TLA-1 ESBLs were disseminated in most hospitals analyzed and CTX-M-15 was emerging in one of the studied hospitals. This work highlights the proper use of antibiotics to avoid the selection of these types of multiresistant bacteria.     

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...     

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.     

Roles of SIRT1 in high glucose-induced endothelial impairment: association with diabetic atherosclerosis

Background and Aims

We undertook this study to investigate the roles of SIRT1 in high glucose-induced endothelial impairment and their association with diabetic atherosclerosis.

Methods

Otsuka Long-Evans Tokushima Fatty (OLETF) rats and nondiabetic rats of the same genetic background were included. Real-time PCR was used to detect SIRT1 mRNA expression in abdominal aorta at week 42. To further investigate the roles of SIRT1 on the function of endothelial cells in high glucose, human endothelial cells were treated with SIRT1 activator resveratrol for 24 h before being cultured in high glucose medium for 48 h.

Results

Along with the early manifestation of atherosclerosis, SIRT1 mRNA level in OLETF group was significantly lower than that in control group (p <0.05). Compared with control cells, high glucose decreased nitric oxide (NO) secretion, but resveratrol treatment increased the expression of SIRT1 and the secretion of NO. After interfering with the expression of SIRT1 using SIRT1 siRNA, the effects of resveratrol on NO secretion were impaired. SIRT1 also counteracted the other pro-atherosclerotic effects of high glucose including the upregulating roles of high glucose on the expression of E-selectin mRNA and the downregulating roles of high glucose on the expression of endothelial nitric oxide synthase.

Conclusions

Decreased expression of SIRT1 in artery may be involved in the initiation and development of diabetic atherosclerosis. Increasing SIRT1 expression may hold great promise in the prevention and therapy of atherosclerosis in diabetic patients.     

Possible impact of global warming on the evolution of hemagglutinins from influenza a viruses

Objective To determine if global warming has an impact on the evolution of hemagglutinins from influenza A viruses, because both global warming and influenza pandemics/epidemics threaten the world. Methods 4 706 hemagglutinins from influenza A viruses sampled from 1956 to 2009 were converted to a time‐series to show their evolutionary process and compared with the global, northern hemisphere and southern hemisphere temperatures, to determine if their trends run in similar or opposite directions. Point‐to‐po...     

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.     

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 System for Classifying Disease Comorbidity Status from Medical Discharge Summaries Using Automated Hotspot and Negated Concept Detection

Objective

Free-text clinical reports serve as an important part of patient care management and clinical documentation of patient disease and treatment status. Free-text notes are commonplace in medical practice, but remain an under-used source of information for clinical and epidemiological research, as well as personalized medicine. The authors explore the challenges associated with automatically extracting information from clinical reports using their submission to the Integrating Informatics with Biology and the Bedside (i2b2) 2008 Natural Language Processing Obesity Challenge Task.

Design

A text mining system for classifying patient comorbidity status, based on the information contained in clinical reports. The approach of the authors incorporates a variety of automated techniques, including hot-spot filtering, negated concept identification, zero-vector filtering, weighting by inverse class-frequency, and error-correcting of output codes with linear support vector machines.

Measurements

Performance was evaluated in terms of the macroaveraged F1 measure.

Results

The automated system performed well against manual expert rule-based systems, finishing fifth in the Challenge's intuitive task, and 13^th in the textual task.

Conclusions

The system demonstrates that effective comorbidity status classification by an automated system is possible.     

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.     

Reduction in pulmonary complications in high risk patients undergoing surgery for total hip replacement under general anesthesia by preoperative intensive inspiratory muscle training : A randomized controlled clinical trial

Objective: To evaluate the effects of preoperative inspiratory muscle training (IMT) on the incidence of atelectasis in patients at high risk of postoperative pulmonary complications scheduled for elective total hip replacement surgery under general anesthesia. Methods: Thirty two high-risk patients undergoing elective total hip replacement surgery under general anesthesia were chosen from Nanjing Medical University, Affiliated Nanjing First Hospital. In this single-blind randomized controlled clinical trial, patients were randomly assigned to receive preoperative inspiratory muscle training or conventional treatment (CT). The major effectiveness outcome variables were atelectasis and duration of postoperative hospitalization. Results: Both groups were comparable prior to surgery. Seven patients in the CT group and 3 in the IMT group developed atelectasis (P = 0.25). Median duration of postoperative hospitalization was 13 days (range, 10～17 days) in the IMT group versus 16 days (range, 11～23 days) in the CT group (Mann-Whitney U statistics, Z = -2.22, P = 0.03). Mean postoperative inspiratory pressure was 5% higher in the IMT group. Conclusion: Preoperative intensive inspiratory muscle training appears to reduce the incidence of atelectasis and duration of postoperative hospitalization in patients at high risk of developing postoperative pulmonary complications who were scheduled for elective total hip replacement surgery under general anesthesia.     

Comparison of bacterioplankton communities in three heavily polluted streams in China

Objective To compare the bacterioplankton communities in streams exposed to pollution of different types. Methods The bacterioplankton communities in three selected heavily polluted streams were investigated by using terminal‐restriction fragment length polymorphism (T‐RFLP) analysis in combination with 16S rRNA gene clone library analysis. Results Both T‐RFLP and 16S rRNA gene clone library revealed a great difference in bacterioplankton community composition in the different streams. Conclusion This work ...     

Resistance Is Futile: But It Is Slowing the Pace of EHR Adoption Nonetheless

Objective

The purpose of this study is to reassess the projected rate of Electronic Health Record (EHR) diffusion and examine how the federal government's efforts to promote the use of EHR technology have influenced physicians' willingness to adopt such systems. The study recreates and extends the analyses conducted by Ford et al.¹ The two periods examined come before and after the U.S. Federal Government's concerted activity to promote EHR adoption.

Design

Meta-analysis and bass modeling are used to compare EHR diffusion rates for two distinct periods of government activity. Very low levels of government activity to promote EHR diffusion marked the first period, before 2004. In 2004, the President of the United States called for a “Universal EHR Adoption” by 2014 (10 yrs), creating the major wave of activity and increased awareness of how EHRs will impact physicians' practices.

Measurement

EHR adoption parameters—external and internal coefficients of influence—are estimated using bass diffusion models and future adoption rates are projected.

Results

Comparing the EHR adoption rates before and after 2004 (2001-2004 and 2001-2007 respectively) indicate the physicians' resistance to adoption has increased during the second period. Based on current levels of adoption, less than half the physicians working in small practices will have implemented an EHR by 2014 (47.3%).

Conclusions

The external forces driving EHR diffusion have grown in importance since 2004 relative to physicians' internal motivation to adopt such systems. Several national forces are likely contributing to the slowing pace of EHR diffusion.     

Semantic Classification of Diseases in Discharge Summaries Using a Context-aware Rule-based Classifier

Objective

Automated and disease-specific classification of textual clinical discharge summaries is of great importance in human life science, as it helps physicians to make medical studies by providing statistically relevant data for analysis. This can be further facilitated if, at the labeling of discharge summaries, semantic labels are also extracted from text, such as whether a given disease is present, absent, questionable in a patient, or is unmentioned in the document. The authors present a classification technique that successfully solves the semantic classification task.

Design

The authors introduce a context-aware rule-based semantic classification technique for use on clinical discharge summaries. The classification is performed in subsequent steps. First, some misleading parts are removed from the text; then the text is partitioned into positive, negative, and uncertain context segments, then a sequence of binary classifiers is applied to assign the appropriate semantic labels.

Measurement

For evaluation the authors used the documents of the i2b2 Obesity Challenge and adopted its evaluation measures: F₁-macro and F₁-micro for measurements.

Results

On the two subtasks of the Obesity Challenge (textual and intuitive classification) the system performed very well, and achieved a F₁-macro = 0.80 for the textual and F₁-macro = 0.67 for the intuitive tasks, and obtained second place at the textual and first place at the intuitive subtasks of the challenge.

Conclusions

The authors show in the paper that a simple rule-based classifier can tackle the semantic classification task more successfully than machine learning techniques, if the training data are limited and some semantic labels are very sparse.     

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...     

Profiling Characteristics of Internet Medical Information Users

Objective

The Internet's potential to bolster health promotion and disease prevention efforts has attracted considerable attention. Existing research leaves two things unclear, however: the prevalence of online health and medical information seeking and the distinguishing characteristics of individuals who seek that information.

Design

This study seeks to clarify and extend the knowledge base concerning health and medical information use online by profiling adults using Internet medical information (IMI). Secondary analysis of survey data from a large sample (n = 6,119) representative of the Atlanta, GA, area informed this investigation.

Measurements

Five survey questions were used to assess IMI use and general computer and Internet use during the 30 days before the survey was administered. Five questions were also used to assess respondents' health care system use. Several demographic characteristics were measured.

Results

Contrary to most prior research, this study found relatively low prevalence of IMI-seeking behavior. Specifically, IMI use was reported by 13.2% of all respondents (n = 6,119) and by 21.1% of respondents with Internet access (n = 3,829). Logistic regression models conducted among respondents accessing the Internet in the previous 30 days revealed that, when controlling for several sociodemographic characteristics, home computer ownership, online time per week, and health care system use are all positively linked with IMI-seeking behavior.

Conclusions

The data suggest it may be premature to embrace unilaterally the Internet as an effective asset for health promotion and disease prevention efforts that target the public.     

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.