Quantification of coronary arterial stenoses in CTA using fuzzy distance transform

Quantification of coronary arterial stenoses is useful for the diagnosis of several coronary heart diseases. Being noninvasive, economical and informative, computed tomographic angiography (CTA) has become a common modality for monitoring disease status and treatment effects. Here, we present a new method for detecting and quantifying coronary arterial stenosis in CTA using fuzzy distance transform (FDT) approach and a new coherence analysis of observed data for computing expected local diameter. FDT allows computing local depth at each image point in the presence of partial voluming and thus, eliminates the need for binarization, commonly, associated with inclusion of additional errors. In the current method, coronary arterial stenoses are detected and their severities are quantified by analyzing FDT values along the medial axis of an arterial tree obtained by its skeletonization. A new skeletal pruning algorithm has been developed toward improving the quality of medial axes and thereby, enhancing the accuracy of stenosis detection and quantification. Further, we have developed a new method to estimate “expected diameter” along a given arterial branch using a new coherence analysis of observed diameter values along the branch. The overall method is completed in the following steps - (1) fuzzy segmentation of coronary artery in CTA, (2) FDT computation of coronary arteries, (3) medial axis computation, (4) estimation of observed and expected diameters along arteries and (5) detection of stenoses and quantification of arterial blockage. The performance of this method has been quantitatively evaluated on a realistic coronary artery phantom dataset with randomly simulated stenoses and the results have been compared with a binary distance transform based and a conventional binary algorithm. The method has also been applied on a clinical CTA dataset from thirteen heart patients and the results have been compared with an expert's quantitative assessment of stenoses. Results of the phantom experiment indicate that the new method (error: 0.53%) is significantly more accurate as compared to both binary distance transform based (error 2.11%) and conventional binary (error 3.71%) methods. Also, the results of the clinical study indicate that the new FDT-based method (kappa coefficient = 87.9%) is highly in agreement with the expert's assessments and, in this respect, outperforms the other two methods (kappa coefficients = 75.2% and 69.5%).     

Multidisciplinary intestinal rehabilitation in acute type II intestinal failure: Results from an intestinal rehabilitation team

BackgroundType II (acute) intestinal failure (IF) is usually caused by complications of abdominal surgery resulting in enteric fistulas or proximal stomas and requires parenteral nutrition (PN) for several months. This study aimed to evaluate clinical management and outcome of type II IF patients in a single center.MethodsMedical records of patients referred to the Intestinal Rehabilitation Team (IRT) at Samsung Medical Center (Seoul, Korea) were retrospectively analyzed.ResultsFrom 2014 to 2019, 34 patients with IF were referred. 28 patients were type II IF and were included in the analysis. There were 17 males and 11 females. Mean age of patients was 56.7 years. Pathophysiology of IF were high-output stoma in 16 cases, extensive bowel resection (with bowel in continuity) in 7 cases, and enterocutaneous fistula in 5 cases. The catastrophic events necessitating abdominal surgery in the patients were adhesive ileus in 9 cases, superior mesenteric artery thrombosis in 8 cases, internal herniation of bowel in 5 cases, traumatic bowel injury in 3 cases, and ischemic enteritis in 3 cases. Following medical and surgical rehabilitation, 10 patients (35.7%) were weaned off PN and overall mortality was 28.5%. Deaths were related to progression of underlying malignancies in 4 cases, liver failure in 3 cases, and sepsis in 1 case. Thirteen patients underwent surgery to restore bowel continuity. Six postoperative complications occurred in 4 patients (30.7%) and there were no postoperative mortalities.ConclusionStandardized care including restorative surgery resulted in successful outcomes in type II IF patients in this cohort.     

Beyond STRs: The Role of Diallelic Markers in Forensic Genetics

Short tandem repeat (STR) polymorphisms have been firmly established as standard DNA marker systems since more than 15 years both in forensic stain typing as well as in paternity and kinship testing. However, when analyzing genetic relationships in deficiency cases, STRs have a couple of disadvantages due to the sometimes poor biostatistical efficiency as well as the possibility to observe one or more genetic inconsistencies that could also be explained by mutational events. In such situations, additional robust markers with negligible mutations rates such as single nucleotide polymorphisms (SNPs) and insertion/deletion markers (indels) can be used as adjuncts to provide decisive genetic information in favor for or against the assumed relationship. Both SNPs and indels can now be typed more easily using multiplexes of up to 50 loci based on fragment length analysis on instruments available in all routine forensic and paternity testing laboratories, thus making it possible to extend the range of markers beyond the currently used STRs.     

The Quick Mild Cognitive Impairment screen correlated with the Standardized Alzheimer's Disease Assessment Scale–cognitive section in clinical trials

ObjectivesThe Alzheimer's Disease Assessment Scale–cognitive section and its standardized version (SADAS-cog) are the current standard for assessing cognitive outcomes in clinical trials of dementia. This study compares a shorter cognitive instrument, the Quick Mild Cognitive Impairment (Qmci) screen, with the SADAS-cog as outcome measures in clinical trials.Study Design and SettingThe SADAS-cog, Qmci, Clinical Dementia Rating (CDR) scale, and the Lawton–Brady activities of daily living (ADL) scale were assessed at multiple time points, over 1 year in a multicenter randomized clinical trial of 406 patients with mild to moderate Alzheimer's dementia. Correlations were estimated using regression at each time point, all time points, and mean values across time. Responsiveness was assessed using the standardized response mean (SRM).ResultsRegression for pooled time points showed strong and significant correlation between the SADAS-cog and Qmci (r = −0.75, P < 0.001). Correlations remained strong for mean values across time and at each time point. The SADAS-cog and Qmci also correlated with CDR and ADL scores. There was no difference in SRMs between the SADAS-cog and Qmci [t(357) = −0.32, P = 0.75].ConclusionThe Qmci correlated strongly with the SADAS-cog and both were equally responsive to deterioration. We suggest that clinicians and investigators can substitute the shorter Qmci for the SADAS-cog.     

Physiology of Intestinal Absorption and Secretion

Virtually all nutrients from the diet are absorbed into blood across the highly polarized epithelial cell layer forming the small and large intestinal mucosa. Anatomical, histological, and functional specializations along the gastrointestinal tract are responsible for the effective and regulated nutrient transport via both passive and active mechanisms. In this chapter, we summarize the current state of knowledge regarding the mechanism of intestinal absorption of key nutrients such as sodium, anions (chloride, sulfate, oxalate), carbohydrates, amino acids and peptides, lipids, lipid- and water-soluble vitamins, as well as the major minerals and micronutrients. This outline, including the molecular identity, specificity, and coordinated activities of key transport proteins and genes involved, serves as the background for the following chapters focused on the pathophysiology of acquired and congenital intestinal malabsorption, as well as clinical tools to test and treat malabsorptive symptoms.     

Study of autosomal STR loci with IBS method in full sibling identification

Objective: We investigated the application of 51 autosomal short tandem repeat (STR) loci with the identity by state (IBS) method and a discriminant function algorithm in full-sib identification. Methods: A total of 342 pairs of full sibs (FSs) and 3900 pairs of unrelated individuals (UIs) were genotyped for 51 STR loci. Groups were formed in accordance with discrimination power (DP) values and the number of loci, and IBS scores of FSs and UIs were analyzed and compared. The discriminant functions of FS-UI were determined by using the Fisher discriminant with SPSS software. Results: All IBS in FSs and UIs groups showed normal distributions and there were significant differences between FS-UI. Receiver operating characteristic curves revealed that the detection efficiency of full-sib identification was affected by both the locus polymorphism and the number of loci detected. Comparing the rate of false positive and false negative of discriminant function between groups, a higher average DP value and larger number of loci detected were associated with a lower rate of miscarriage of justice and were more helpful for full-sib identification. Conclusion: STRs with higher DP values should be selected when additional autosomal markers are required for FS identification. Discriminant analysis with the IBS method is highly applicable for the FS-UI test.     

Strategies for Distance Education

Abstract

Advances in and access to technology have loosened academia's ties to the traditional classroom. In this paper we present our experiences in developing, implementing, and evaluating three approaches to distance education. The first program was delivered by interactive videoconferencing and provided multiple gerontological lessons for Extension agents gathered at two different sites in Virginia. The second program was a graduate-level course taught simultaneously at multiple sites also using interactive videoconferencing. The third program was a full-fledged Internet course whose target audience included students enrolled in a gerontology certificate program. The overall strengths of the programs included enhancing the instructors' ability to reach students in a variety of locations without leaving campus and expanding the flexibility and availability of course offerings. The weaknesses and constraints of the various approaches centered on the amount of instructor time necessary to develop and implement the instructional units, technological problems, and student involvement and motivation.