294 research outputs found
Positive Predictive Value of Tomosynthesis-guided Biopsies of Architectural Distortions Seen on Digital Breast Tomosynthesis and without an Ultrasound Correlate
Objective: The objective of the study was to determine the positive predictive value (PPV) of architectural distortions (AD) observed on digital breast tomosynthesis (DBT) and without an ultrasound (US) correlate.
Materials and Methods: In this single-institution, retrospective study, patients who underwent DBT-guided biopsies of AD without any associated findings on digital mammography (DM) or DBT, and without a correlate on targeted US exam, over a 14-month period were included in this study. All patients had DM and DBT and targeted US exams. The PPV was computed along with the exact 95% confidence limits (CL) using simple binomial proportions, with histopathology as the reference standard.
Results: A total of 45 ADs in 45 patients met the inclusion criteria. Histopathology indicated 6/45 (PPV: 13.3%, CL: 5.1-26.8%), ADs were malignant, including one high-risk lesion that was upgraded at surgery. ADs were appreciated only on DBT in 12/45 (26.7%) patients, and on both DBT and DM in 33/45 (73.3%) patients, and the corresponding PPV was 25% (3/12, CL: 5.5-57.2%) and 9.1% (3/33, CL: 1.9-24.3%), respectively. In all analyses, the observed PPV significantly exceeded the 2% probability of malignancy for Breast Imaging Reporting and Data System-3 diagnostic categories (P \u3c 0.004).
Conclusions: The PPV of malignancy in DBT detected AD without an US correlate in our series of 45 cases was 6/45 (13.3%). In the absence of an US correlate, the PPV of AD is lower than that mentioned in prior literature but exceeds the 2% threshold to justify DBT-guided biopsy
Structure-Based Phylogeny as a Diagnostic for Functional Characterization of Proteins with a Cupin Fold
The members of cupin superfamily exhibit large variations in their sequences, functions, organization of domains, quaternary associations and the nature of bound metal ion, despite having a conserved beta-barrel structural scaffold. Here, an attempt has been made to understand structure-function relationships among the members of this diverse superfamily and identify the principles governing functional diversity. The cupin superfamily also contains proteins for which the structures are available through world-wide structural genomics initiatives but characterized as "hypothetical". We have explored the feasibility of obtaining clues to functions of such proteins by means of comparative analysis with cupins of known structure and function.A 3-D structure-based phylogenetic approach was undertaken. Interestingly, a dendrogram generated solely on the basis of structural dissimilarity measure at the level of domain folds was found to cluster functionally similar members. This clustering also reflects an independent evolution of the two domains in bicupins. Close examination of structural superposition of members across various functional clusters reveals structural variations in regions that not only form the active site pocket but are also involved in interaction with another domain in the same polypeptide or in the oligomer.Structure-based phylogeny of cupins can influence identification of functions of proteins of yet unknown function with cupin fold. This approach can be extended to other proteins with a common fold that show high evolutionary divergence. This approach is expected to have an influence on the function annotation in structural genomics initiatives
Replantation of Nine Fingers in a Patient: A case report
Amputation of multiple fingers of both hands is a rare and serious injury. We report a case of a 41-year-old male patient who presented to Khoula Hospital, Muscat, Oman, in 2015 with the amputation of nine fingers due to a workplace injury. With two teams working in tandem, all the amputated fingers were re-attached. A total of seven fingers survived and the patient regained reasonable functionality of his hands. To the best of the authors’ knowledge, this is the first case of several finger amputations in Oman.Keywords: Fingers; Traumatic Amputation; Crush Injuries; Replantation; Case Report; Oman
Robot-assisted measurement for hydrologic understanding in data sparse regions
This article describes the field application of small, low-cost robots for remote surface data collection and an automated workflow to support water balance computations and hydrologic understanding where water availability data is sparse. Current elevation measurement approaches,
such as manual surveying and LiDAR, are costly and infrequent, leading to potential inefficiencies for
quantifying the dynamic hydrologic storage capacity of the land surface over large areas. Experiments to evaluate a team of two different robots, including an unmanned aerial vehicle (UAV) and an unmanned surface vehicle (USV), to collect hydrologic surface data utilizing sonar and visual sensors were conducted at three different field sites within the Arkavathy Basin river network located near
Bangalore in Karnataka, South India. Visual sensors were used on the UAV to capture high resolution imagery for topographic characterization, and sonar sensors were deployed on the USV to capture bathymetric readings; the data streams were fused in an automated workflow to determine the storage capacity of agricultural reservoirs (also known as “tanks”) at the three field sites. This study suggests: (i) this robot-assisted methodology is low-cost and suitable for novice users, and (ii) storage capacity data collected at previously unmapped locations revealed strong power-type relationships between surface area, stage, and storage volume, which can be incorporated into modeling of landscape-scale hydrology. This methodology is of importance to water researchers and practitioners because it produces local, high-resolution representations of bathymetry and topography and enables water balance computations at small-watershed scales, which offer insight into the present-day dynamics of a strongly human impacted watershed
Ultrasound Imaging Morphology is Associated with Biological Behavior in Invasive Ductal Carcinoma of the Breast
Objectives: Ultrasound (US) is commonly used for diagnostic evaluation of breast lesions. The objective of this study was to investigate the association between US imaging morphology from routine radiologists\u27 interpretation and biological behavior such as receptor status and tumor grade determined from histopathology in invasive ductal carcinoma (IDC).
Material and Methods: This retrospective study included 453 patients with pathology-verified diagnosis of IDC who had undergone US imaging and had surgery over a 5-year period. US and surgical pathology reports were reviewed and compiled. Correlation analyses and age-adjusted multivariable models were used to determine the association between US imaging morphology and receptor status, tumor grade, and germ line mutation of the breast cancer genes (BRCA1 and BRCA2). The odds ratio (OR), area under receiver operating characteristic curve (AUC), and 95% confidence intervals (CI) were obtained.
Results: The likelihood for high-grade cancer increased with size (OR: 1.066; CI: 1.042-1.091) and hypo-echogenicity (OR: 2.044; CI: 1.337-3.126), and decreased with angular or spiculated margins (OR: 0.605; CI: 0.393-0.931) and posterior acoustic shadowing (OR: 0.352; CI: 0.238-0.523). These features achieved an AUC of 0.799 (CI: 0.752-0.845) for predicting high-grade tumors. The likelihood for Estrogen Receptor-positive tumors increased with posterior acoustic shadowing (OR: 3.818; CI: 2.206-6.607), angulated or spiculated margins (OR: 2.596; CI: 1.159-5.815) and decreased with US measured tumor size (OR: 0.959; CI: 0.933-0.986) and hypoechoic features (OR: 0.399; CI: 0.198- 0.801), and achieved an AUC of 0.787 (CI: 0.733-0.841). The likelihood for Progesterone Receptor-positive tumors increased with posterior acoustic shadowing (OR: 2.732; CI: 1.744-4.28) and angulated or spiculated margins (OR: 2.618; CI: 1.412-4.852), and decreased with US measured tumor size (OR: 0.961; CI: 0.937-0.985) and hypoechoic features (OR: 0.571; CI: 0.335-0.975), and achieved an AUC of 0.739 (CI: 0.689-0.790). The likelihood for Human epidermal growth factor receptor 2-positive tumors increased with heterogeneous echo texture (OR: 2.141; CI: 1.17- 3.919) and decreased with angulated or spiculated margins (OR: 0.408; CI: 0.177-0.944), and was marginally associated with hypoechoic features (OR: 2.101; CI: 0.98-4.505) and circumscribed margins (OR: 4.225; CI: 0.919-19.4). The model with the aforementioned four US morphological features and achieved an AUC of 0.686 (CI: 0.614-0.758). The likelihood for triple-negative breast cancers increased with hypo-echogenicity (OR: 2.671; CI: 1.249-5.712) and decreased with posterior acoustic shadowing (OR: 0.287; CI: 0.161-0.513), and achieved an AUC of 0.739 (CI: 0.671- 0.806). No statistical association was observed between US imaging morphology and BRCA mutation.
Conclusion: In this study of over 450 IDCs, significant statistical associations between tumor grade and receptor status with US imaging morphology were observed and could serve as a surrogate imaging marker for the biological behavior of the tumor
Anti-Urolithiatic Activity of Melia Azedarach Linn Leaf Extract in Ethylene Glycol-Induced Urolithiasis in Male Albino Rats
Purpose: To investigate the anti-urolithiatic activity of the aqueous and alcoholic extracts of Melia azedarach Linn leaves in calcium oxalate urolithiasis in male albino rats.Methods: The effect of oral administration of aqueous and ethanol extracts of Melia azedarach Linn leaves on calcium oxalate urolithiasis has been investigated. Lithiasis was induced by oral adminstration of ethylene glycol (0.75 %v/v) in male albino rats for 28 days. Each of the extract (250 mg/kg) was administered orally day 0 as a prophylactic regimen and from day 15 as a curative regimen. Regular administration of ethylene glycol caused hyperoxaluria in ethylene glycol-fed animals, leading to increased renal retention and excretion of oxalate, calcium and phosphate. Histopathological study, urine microscopy, serum analysis and biochemical analysis of kidney homogenate were performed.Results: Oxalate and calcium excretion in urine increased (p < 0.01) to 3.68 ± 0.01 and 4.5 ± 0.01 mg/24 h, respectively, in lithiatic control animals compared to (0.37 ± 0.01 and 1.27 ± 0.12 mg/24 h) for the normal control group. Treatment with aqueous or ethanol extract (250 mg/kg, p.o.) significantly (p <0.01) reduced the elevated levels of calcium, oxalate and phosphate excretion in urine to 0.79 ± 0.01 and 1.09 ± 0.04 mg/24 h, respectively. Following treatment with the ethanol extract (250mg/kg), serum creatinine excretion was restored from 0.95 ± 0.01 mg/24 h to the normal level of 0.87 ± 0.01 mg/24 h. The results were comparable to those of the standard drug, allopurinol (50 mg/kg p.o.).Histopathological data for the kidney supported the foregoing results.Conclusions: The results demonstrate that the aqueous and ethanol extracts of Melia azedarach Linn leaves have potent antiurolithiatic activity against ethylene glycol-induced calcium oxalate urolithiasis in male albino rats.Keywords: Melia azedarach, Antiurolithiatic, Ethylene glycol, Urolithiasis, Excretion, Kidne
Spatial characterization of long-term hydrological change in the Arkavathy watershed adjacent to Bangalore, India
The complexity and heterogeneity of human water use over large spatial areas and decadal timescales can impede the understanding of hydrological change, particularly in regions with sparse monitoring of the water cycle. In the Arkavathy watershed in southern India, surface water inflows to major reservoirs decreased over a 40-year period during which urbanization, groundwater depletion, modification of the river network, and changes in agricultural practices also occurred. These multiple, interacting drivers combined with limited hydrological monitoring make attribution of the causes of diminishing water resources in the watershed challenging and impede effective policy responses. To mitigate these challenges, we developed a novel, spatially distributed dataset to understand hydrological change by characterizing the residual trends in surface water extent that remain after controlling for precipitation variations and comparing the trends with historical land use maps to assess human drivers of change. Using an automated classification approach with subpixel unmixing, we classified water extent in nearly 1700 man-made lakes, or tanks, in Landsat images from 1973 to 2010. The classification results compared well with a reference dataset of water extent of tanks (R2 = 0.95). We modeled the water extent of 42 clusters of tanks in a multiple regression on simple hydrological covariates (including precipitation) and time. Inter-annual variability in precipitation accounted for 63 % of the predicted variability in water extent. However, precipitation did not exhibit statistically significant trends in any part of the watershed. After controlling for precipitation variability, we found statistically significant temporal trends in water extent, both positive and negative, in 13 of the clusters. Based on a water balance argument, we inferred that these trends likely reflect a non-stationary relationship between precipitation and watershed runoff. Independently of precipitation, water extent increased in a region downstream of Bangalore, likely due to increased urban effluents, and declined in the northern portion of the Arkavathy. Comparison of the drying trends with land use indicated that they were most strongly associated with irrigated agriculture, sourced almost exclusively by groundwater. This suggests that groundwater abstraction was a major driver of hydrological change in this watershed. Disaggregating the watershed-scale hydrological response via remote sensing of surface water bodies over multiple decades yielded a spatially resolved characterization of hydrological change in an otherwise poorly monitored watershed. This approach presents an opportunity to understand hydrological change in heavily managed watersheds where surface water bodies integrate upstream runoff and can be delineated using satellite imagery
South Indian Iron Age iron and high carbon steel: with reference to Kadebakele and comparative insights from Mel-siruvalur
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