159,771 research outputs found
The UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factors
No full textThe UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factor
Validated prediction model for the development of primary open-angle glaucoma in individuals with ocular hypertension
No full textObjective
To test the validity and generalizability of the Ocular Hypertension Treatment Study (OHTS) prediction model for the development of primary open-angle glaucoma (POAG) in a large independent sample of untreated ocular hypertensive individuals and to develop a quantitative calculator to estimate the 5-year risk that an individual with ocular hypertension will develop POAG.
Design
A prediction model was developed from the observation group of the OHTS and then tested on the placebo group of the European Glaucoma Prevention Study (EGPS) using a z statistic to compare hazard ratios, a c statistic for discrimination, and a calibration χ2 for systematic overestimation/underestimation of predicted risk. The 2 study samples were pooled to increase precision and generalizability of a 5-year predictive model for developing POAG.
Participants
The OHTS observation group (n = 819; 6.6 years’ median follow-up) and EGPS placebo group (n = 500; 4.8 years’ median follow-up).
Testing
Data were collected on demographic characteristics, medical history, ocular examination visual fields (VFs), and optic disc photographs.
Main Outcome Measure
Development of reproducible VF abnormality or optic disc progression as determined by masked readers and attributed to POAG by a masked end point committee.
Results
The same predictors for the development of POAG were identified independently in both the OHTS observation group and the EGPS placebo group—baseline age, intraocular pressure, central corneal thickness, vertical cup-to-disc ratio, and Humphrey VF pattern standard deviation. The pooled multivariate model for the development of POAG had good discrimination (c statistic, 0.74) and accurate estimation of POAG risk (calibration χ2, 7.05).
Conclusions
The OHTS prediction model was validated in the EGPS placebo group. A calculator to estimate the 5-year risk of developing POAG, based on the pooled OHTS–EGPS predictive model, has high precision and will be useful for clinicians and patients in deciding the frequency of tests and examinations during follow-up and advisability of initiating preventive treatment
Effect of interferon-alpha on progression of cirrhosis to hepatocellular carcinoma: a retrospective cohort study.
No full textAbstract
BACKGROUND:
There is debate about whether interferon-alpha treatment lowers the risk of progression to hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis and whether any effect is limited to certain subgroups. We investigated these issues by retrospective analysis of data for 913 patients from Italy and Argentina.
METHODS:
21 centres reported patients from their records who had chronic viral hepatitis and Child's A cirrhosis, were positive for HBsAg or hepatitis-C-virus antibodies (anti-HCV), and had been screened yearly for at least 3 years by ultrasonography and alpha-1-fetoprotein testing. Prognostic risk factors for hepatocellular carcinoma defined by multivariate Cox regression analysis and individual observation time were used for group matching and conditional logistic regression analysis of the independent interferon-alpha treatment effect.
FINDINGS:
After group matching, the number of patients was reduced to 637. Age, male sex, and portal hypertension were significant risk factors for hepatocellular carcinoma (each p < 0.001); hepatic inflammation (p = 0.21) and iron storage (p = 0.18) were also included in the model 66 (19%) of 356 untreated patients and 29 (10%) of 281 treated patients developed hepatocellular carcinoma (relative risk 1.99 [95% CI 1.09-3.64]); the corresponding proportions for anti-HCV-positive patients were 48 (18.5%) of 259 versus 21 (9.1%) of 232 (3.14 [1.46-6.80]), and those for hepatitis-B-virus-infected (HBV) patients were 18 (10%) of 97 and eight (16%) of 49 (0.98 [0.33-2.92]). Among anti-HCV patients without HBV markers, 29 (20%) of 129 untreated and six (5%) of 116 treated patients developed hepatocellular carcinoma (6.28 [1.65-23.8]).
INTERPRETATION:
Interferon treatment lowered the rate of progression to hepatocellular carcinoma two fold. The risk reduction was apparently greater for patients with chronic hepatitis C and no evidence of HBV infection. Future studies should stratify HCV-infected patients by HBV status
The impact of cognitive testing on the welfare of group housed primates
No full textProviding cognitive challenges to zoo-housed animals may provide enriching effects and subsequently enhance their welfare. Primates may benefit most from such challenges as they often face complex problems in their natural environment and can be observed to seek problem solving opportunities in captivity. However, the extent to which welfare benefits can be achieved through programmes developed primarily for cognitive research is unknown. We tested the impact of voluntary participation cognitive testing on the welfare of a socially housed group of crested macaques (Macaca nigra) at the Macaque Study Centre (Marwell Zoo). First, we compared the rate of self-directed and social behaviours on testing and non-testing days, and between conditions within testing days. Minimal differences in behaviour were found when comparing testing and non-testing days, suggesting that there was no negative impact on welfare as a result of cognitive testing. Lipsmacking behaviours were found to increase and aggressive interaction was found to decrease in the group as a result of testing. Second, social network analysis was used to assess the effect of testing on associations and interactions between individuals. The social networks showed that testing subjects increased their association with others during testing days. One interpretation of this finding could be that providing socially housed primates with an opportunity for individuals to separate from the group for short periods could help mimic natural patterns of sub-group formation and reunion in captivity. The findings suggest, therefore, that the welfare of captive primates can be improved through the use of cognitive testing in zoo environments
Development of Quality Control Ranges for Biocide Susceptibility Testing
No full textEvery laboratory test needs validation by quality controls. For biocide susceptibility testing (BST), neither quality control (QC) strains nor QC ranges applicable to these strains are currently available. As QC strains, four well-defined laboratory reference strains (Staphylococcus aureus ATCC® 6538, Enterococcus hirae ATCC® 10541, Escherichia coli ATCC® 10536 and Pseudomonas aeruginosa ATCC® 15442), which have been used previously for biocide efficacy testing, were selected. In an interlaboratory trial with eleven participating laboratories, BST QC ranges should be developed for the aforementioned four strains and the four biocides benzalkonium chloride, chlorhexidine, octenidine and polyhexanide. The performance of three different lots of tryptic soy broth was explored using the broth microdilution method and the data were subsequently evaluated using the RangeFinder software. As a result, QC ranges were defined for all reference strain–biocide combinations, except for P. aeruginosa ATCC® 15442 with the two biocides chlorhexidine and polyhexanide. The development of the latter two QC ranges was not possible, due to the limited solubility of the biocides in the test range required for P. aeruginosa ATCC® 15442. The newly developed QC ranges comprise three to five dilution steps. The establishment of QC ranges will contribute to the validation of BST in the future
Antifungal susceptibility profiles of Candida isolates from a prospective survey of invasive fungal infections in Italian intensive care units
No full textThe antifungal susceptibility pattern of 302 Candida isolates collected during an Italian survey on invasive fungal infections in an intensive care setting was investigated. The results were correlated with some epidemiological data and compared with the antifungal profiles obtained in a previous survey. No resistance to echinocandins was detected. The overall resistance levels to fluconazole, posaconazole and voriconazole were 12.6, 6.0 and 7.1 %, respectively. Candida tropicalis and Candida parapsilosis accounted for more than half of all the fluconazole resistant isolates. Reduced susceptibility to fluconazole is not uncommon among isolates (12.3 %) and appears to be increasing, particularly among C. parapsilosis isolates, which showed an increase in resistant isolates from 2 % in the 1990s to 25.8 % in the present study. Routine antifungal susceptibility testing of this species is therefore recommended
GROUP TESTING AND SENSE OF BELONGING IN REFORM-BASED CALCULUS: EQUITABLE FOR ALL WOMEN?
No full textThere continues to be a national concern about the shortage of science, technology, engineering, and mathematics (STEM) graduates needed to fill current and anticipated STEM workforce positions. There is an additional concern regarding attracting and maintaining women in the STEM disciplines. In this study, I investigated one part of the STEM workforce problem by focusing on women in Calculus I courses who intend to major in a STEM discipline. Calculus presents a unique leak in the STEM pipeline for women because women who perform poorly in calculus are more likely to leave STEM fields than men who perform poorly in calculus. The main focus of this study is women’s sense of belonging in calculus, as sense of belonging is one reason women leave the historically male-dominated STEM fields. Specifically, this study investigates the communication women have with their peers in a group test environment and how these interactions may influence the women’s sense of belonging to a mathematics community. The main purpose of my study was to examine the social interactions of the group members during a group test, the differences in the interactions for groups with different compositions, and how the interactions might explain changes in the women’s sense of belonging to mathematics in a reform Calculus I course. Women’s communication around a group testing activity in Calculus I is significant because it has the potential to change assessment practices and promote retention of women in STEM by increasing women’s collaboration and sense of belonging in a STEM community in a course required of all STEM majors. I used an exploratory descriptive mixed methods design to investigate female students’ sense of belonging and their social interactions with group members in a Calculus I reform class. The results of the study revealed: (1) white women performed better when tested individually than in groups, (2) students who are under-represented minorities by race performed better when tested in groups than individually, (3) groups with more women had more equitable social interactions around the mathematics, (4) groups with only women felt more frustrated and asked more questions around the mathematics, (5) when studying communication and sense of belonging in mathematics, researchers may need to consider the intersectionality of race and gender.Ph.D
Comparison of rapid molecular testing methods for detecting respiratory viruses in emergency care: a prospective study
No full textBackground: Respiratory tract infections (RTIs) caused by contagious viruses are common among patients presenting to the emergency department (ED). Early detection of these viruses can help prevent nosocomial transmission.Aim: To investigate the efficacy of three rapid molecular methods, namely FilmArray® Pneumonia Panel plus (FAP plus), ID NOW™ Influenza A and B 2 (ID NOW2) point-of-care test, and an in-house real-time polymerase chain reaction (RT-PCR) test, to identify patients with viral RTIs requiring isolation in an emergency setting.Methods: We included a FilmArray® Pneumonia Panel plus in the initial workup of patients with suspected RTIs during a flu season. The RT-PCR and the influenza point-of-care test were performed as part of routine diagnostics, on demand from the treating physicians. We compared viral detections and compared time to positive test results for each method.Findings: The FAP plus significantly reduced the turnaround time and was able to identify 95% patients with potential contagious viral RTI. Routine diagnostics ordered by the treating physician had a turnaround time of a median 22 h and detected 87% of patients with potential contagious viral RTI. In patients that had all three tests, the ID NOW2 detected 62% of patients with influenza.Conclusions: The FAP plus was able to rapidly and reliably identify patients with potential contagious viral RTIs; its use was feasible in the ED setting. Failing to test patients with viral RTI and using tests with long turnaround time may lead to nosocomial transmission of viral infections and adverse patient outcomes
All repair and reconstruction. Techniques from the SANTI study group
No full textBackground: Combining an anterior cruciate ligament (ACL) reconstruction with an anterolateral ligament (ALL) reconstruction results in significant advantages including reduced graft rupture rates, a lower risk of reoperation for secondary meniscectomy, improved knee stability, and higher rates of return to preinjury levels of sport. Indications: The previously reported indications for combined ACL and ALL reconstruction are as follows: ACL reconstruction revision; high-grade pivot shift test; long-term ACL rupture; young patients; pivoting activities; concomitant medial meniscus repair, and, specifically, regarding the ALL repair, it must be an acute surgery (within 15 days from injury). Technique Description: Several modern techniques have been described to repair and reconstruct the ALL. This technical note details a number of these techniques performed by the Scientific Anterior Cruciate Ligament Network International (SANTI) Study Group. Results: First, we describe a combined ACL reconstruction and double-bundle ALL reconstruction using hamstring autograft. Secondly, we describe a single-bundle ALL reconstruction using gracilis autograft. Thirdly, we describe an ALL reconstruction technique using a knotless soft anchor, which provides shallow fixation and prevents tunnel convergence. Finally, we describe a technique for ALL repair. Conclusion: Several techniques have been described to repair and reconstruct the ALL, all offering significant advantages over an isolated ACL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication
Robust automated detection of microstructural white matter degeneration in Alzheimer’s disease using machine learning classification of multicenter DTI data
No full textDiffusion tensor imaging (DTI) based assessment of white matter fiber tract integrity can support the diagnosis of Alzheimer’s disease (AD). The use of DTI as a biomarker, however, depends on its applicability in a multicenter setting accounting for effects of different MRI scanners. We applied multivariate machine learning (ML) to a large multicenter sample from the recently created framework of the European DTI study on Dementia (EDSD). We hypothesized that ML approaches may amend effects of multicenter acquisition. We included a sample of 137 patients with clinically probable AD (MMSE 20.6±5.3) and 143 healthy elderly controls, scanned in nine different scanners. For diagnostic classification we used the DTI indices fractional anisotropy (FA) and mean diffusivity (MD) and, for comparison, gray matter and white matter density maps from anatomical MRI. Data were classified using a Support Vector Machine (SVM) and a Naïve Bayes (NB) classifier. We used two cross-validation approaches, (i) test and training samples randomly drawn from the entire data set (pooled cross-validation) and (ii) data from each scanner as test set, and the data from the remaining scanners as training set (scanner-specific cross-validation). In the pooled cross-validation, SVM achieved an accuracy of 80% for FA and 83% for MD. Accuracies for NB were significantly lower, ranging between 68% and 75%. Removing variance components arising from scanners using principal component analysis did not significantly change the classification results for both classifiers. For the scanner-specific cross-validation, the classification accuracy was reduced for both SVM and NB. After mean correction, classification accuracy reached a level comparable to the results obtained from the pooled cross-validation. Our findings support the notion that machine learning classification allows robust classification of DTI data sets arising from multiple scanners, even if a new data set comes from a scanner that was not part of the training sample
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