347 research outputs found

    Mid-term results with laser atherectomy in the treatment of infrainguinal occlusive disease

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    BackgroundLaser atherectomy offers a potential intervention for multivessel infrainguinal disease in patients with poor revascularization options. Despite promising early results reported in the literature, the proper patient population who might benefit from laser atherectomy has yet to be determined.MethodsFrom July 2004 to June 2006, patients undergoing laser atherectomy were retrospectively reviewed and assessed for comorbidities, operative and follow-up variables potentially associated with the end points of nondefinitive therapy, and limb salvage.ResultsDuring the study period, 40 patients (21 women, 19 men) underwent laser atherectomy, and the average follow-up was 461 ± 49 days (range, 17 to 1050 days). Their average age was 68 ± 2 years (range, 43 to 93 years). The indication for laser atherectomy was critical limb ischemia in 26 (65%) and lower limb claudication in 11 (35%). A total of 47 lesions were treated in the following arterial segments: 34 femoropopliteal and 13 infrapopliteal. Femoropopliteal distribution by the Trans-Atlantic Society Classification (TASC) was A in 3, B in 17, C in 10, D in 4, and infrapopliteal lesions distribution was A in 1, B in 3, C in 4, and D in 5. Adjunctive angioplasty was used in 75% of cases. The overall technical success rate (<50% residual stenosis) was 88%. Laser atherectomy–based treatment was the definitive therapy for 23 patients (58%), and the overall 12-month primary patency was 44%. The limb salvage rate at 12 months in 26 patients with critical limb ischemia was 55%. Renal failure was a risk factor for amputation (P < .001) and failed primary patency (P < .05), type 2 diabetes mellitus was a risk factor for amputation (P < .05), and poor tibial runoff was associated with failed primary patency and amputation (P < .05). Outcome was associated with the number of patent infrapopliteal runoff vessels.ConclusionThese data demonstrate that laser atherectomy can be used with high initial technical success rate. Chronic renal failure and diabetes are risk factors for a negative outcome. Poor results in patients with diabetes and renal failure necessitate careful case selection in this subgroup, in which laser atherectomy is less likely to provide a definitive revascularization result or limb salvage

    {The Noise Handling Properties of the Talbot Algorithm for Numerically Inverting the Laplace Transform}

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    This paper examines the noise handling properties of three of the most widely used algorithms for numerically inverting the Laplace Transform. After examining the genesis of the algorithms, the regularization properties are evaluated through a series of standard test functions in which noise is added to the inverse transform. Comparisons are then made with the exact data. Our main finding is that the Talbot inversion algorithm is very good at handling noisy data and is more accurate than the Fourier Series and Stehfest numerical inversion schemes as they are outlined in this paper. This offers a considerable advantage for it's use in inverting the Laplace Transform when seeking numerical solutions to time dependent differential equations.Peer reviewedFinal Published versio

    Test Re-Test Reliability of Peak Force During Isometric Knee extension and Squat

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    Acquiring reliable performance outcomes for laboratory procedures is critical for evaluation and prescription thereafter. Additionally, reliable data collected from separate testing days may present potential errors in the overall methodological approach. Instructing and testing participants to perform tasks that are relatively new can come with a learning curve and may require additional practice and familiarization. PURPOSE: To determine the reliability of peak force production during the isometric knee extension (KE) and squat (SQ) performed on two separate days. METHODS: Fourteen male (23±3 yrs.; 87.74±11.82 kg; 175.57±6.92 cm ) and 12 female (23±3 yrs., 62.79±5.89kg; 165±5.76cm) lower body resistance trained individuals completed 8 separate maximal isometric voluntary contractions (MVCs) of the KE and SQ using an S-Beam load cell and custom made chair and platform. Following a familiarization visit, each subject randomly completed two MVCs at 110° and 150° (KE110°, KE150°, SQ110°, SQ150°) of knee extension for both performances on two-separate visits. The MVC that had the highest force was chosen for further analysis using the interclass correlation coefficient (ICC3,1) for reliability between days (KE110°, KE150°, SQ110°, SQ150°). RESULTS: For MVCs during KE150°, SQ110°, and SQ150°, there was no systematic variability in force between days (ICC3,1 = 0.71-0.91). However, for KE110° , there was a difference (p= 0.04) in ICC3,1 for peak force between testing days. CONCLUSION: Performing MVCs during isometric KE and SQ on separate days may provide reliable outcomes for measuring force production. However, consideration may need to be taken when requiring participants to perform at knee joint angles that may require more practice or comfortability with the movement task

    Can Recruiting Rankings Predict the Success of NCAA Division I Football Teams? An Examination of the Relationships among Rivals and Scouts Recruiting Rankings and Jeff Sagarin End-of-Season Ratings in Collegiate Football

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    This is the publisher's version, also available electronically from http://www.degruyter.com.The purpose of the present study was to examine the relationships among National Collegiate Athletic Association (NCAA) Division I football teams' 2002 recruiting rankings from the Rivals (RIV) and Scouts (SCO) recruiting services and the Jeff Sagarin end-of-season performance ratings from 2002–2006. The RIV and SCO recruiting services included rankings for 100 common NCAA Division I football teams for the 2002 recruiting season. Each recruiting service included a total point system rating (TOTPTS) and average star rating (AVESTAR). The Jeff Sagarin NCAA football ratings system was chosen as an indicator of the teams' performance. Pearson product moment correlation coefficients (R) and the corresponding predictive indices (R2) were used to examine whether the 2002 RIV & SCO TOTPTS and RIV & SCO AVESTAR ratings could predict the Jeff Sagarin end-of-season ratings and total number of wins for each football team for the 2002 through 2006 seasons. In addition, R and R2 values were computed to examine whether the 2002 Jeff Sagarin end-of-season ratings and total number of wins could predict the following season's recruiting rankings (2003 RIV & SCO TOTPTS and RIV & SCO AVESTAR). The results indicated that RIV & SCO TOTPTS and AVESTAR predicted up to 45% of the variances in the end-of-season ratings and total wins. Thus, other factors (besides recruiting rankings) must be contributing to the end-of-season ratings for the 100 NCAA football teams included in this study. In addition, up to 51% of the variance in RIV & SCO AVESTAR and TOTPTS was predicted by the previous year's end-of-season ratings or total wins, which suggests that more successful seasons tend to yield better subsequent recruiting classes

    Regional Motor Unit Firing Behaviors of Mono- and Bi-Articular Leg Extensor Muscles

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    Motor unit (MU) activation patterns provide vast insight into skeletal muscle contractions and may differ depending on architectural differences. Previous findings have suggested that MU activation patterns, specifically within the quadriceps group, are region-specific; this, along with the architectural differences between the quadriceps muscles, may further influence force production as reflected within the relationships between the firings. PURPOSE: To examine regional activation in proximal and distal regions of biarticular [rectus femoris (RF)] and monoarticular [vastus lateralis (VL)] knee extensors during submaximal isometric knee extensions. METHODS: On two separate randomized visits, eight lower-body resistance trained individuals, 6 males (n=6, age= 25.2 ±3.77) and 2 females (n=2, age= 21 ±1.4), performed submaximal isometric contractions at 30% and 70% of their maximal voluntary contractions (MVC) in a custom-built seat using an S-beam load-cell. Two separate 5-pin surface electromyography (EMG) sensors were used to record activation in the proximal and distal locations of either the VL or RF. Signals were recorded and decomposed into their constituent motor unit action potential (MUAP) trains, validated, and assessed for relative behavioral properties. For subsequent analysis of firing behaviors, the relationships (Slopes and intercepts) between motor unit action potential size (MUAPsize,) recruitment threshold (RT%), and mean firing rate (MFR) were calculated. Twelve separate two-way repeated measures analyses of variance (ANOVA) (location [proximal v distal] x muscle [VL v RF]) were used to compare slopes and intercepts of MFR vs. RT%, MUAPsize vs. RT%, and MFR vs. MUAPsize at both 30% and 70% MVC. RESULTS: There was a significant location x muscle interaction in the MFR v MUAPsize slopes during 30% MVC contraction (pCONCLUSION: The location by muscle interaction in the MFR v MUAPsize slopes during 30% MVC may indicate muscle fiber type distribution differences between sensor locations specifically, more type II fibers in the distal location of the VL

    Comparing thigh muscle cross-sectional area and squat strength among national class Olympic weightlifters, power lifters, and bodybuilders

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    Few studies have compared anthropometric characteristics among national class athletes from different resistance training disciplines, such as Olympic Weightlifting (OL), Power Lifting (PL), and Bodybuilding (BB). Objective: The purpose of the current study was to determine if significant differences exist in the relationship between thigh muscle cross-sectional area and back squat strength among national class athletes from the sports of OL, PL, and BB. Methods: Fifteen national class athletes were assessed for back squat strength, mid-thigh circumference, and mid-thigh skinfold from which total thigh cross-sectional was estimated. A series of One-Way ANOVAs and Pearson Product Moment Correlations were used to compare groups and assess the relationship between variables. Results: The OL (200.18 + 25.16kg) and PL (205.45 + 17.28kg) groups were significantly stronger than the BB (160 + 16.80 kg; p \u3c 0.05) group. However, mid-thigh skinfold thickness (p = 0.36), mid-thigh circumference (p = 0.87), and estimated thigh cross-sectional area (p = 0.34) were not significantly different between groups. Thigh muscle cross-sectional area was weakly correlated to back squat strength in the OL (r = .42) and PL (r = .12) groups, but moderately correlated in the BB (r = .70) group. Conclusion: Thigh cross-sectional area was of relatively minor importance in determining back squat strength for the OL and PL groups, despite these groups being significantly stronger than the BB group. Specific training protocols will elicit different outcomes with regard to muscular hypertrophy that may or may not contribute to a functional increase in back squat strength

    Pediatric kidney transplants with multiple renal arteries show no increased risk of complications compared to single renal artery grafts

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    BackgroundKidney allografts with multiple renal arteries (MRA) are not infrequent and have been historically associated with a higher risk of developing vascular and urologic complications. Reports of kidney transplantation using MRA allografts in the pediatric population remain scarce. The aim of this study was to evaluate if transplantation of allografts with MRA with a surgical intent of creating a single arterial inflow using vascular reconstruction techniques when required, and without the routine use of surgical drains or ureteral stents, is associated with an increased risk of complications when compared to single renal artery (SRA) grafts.MethodsWe retrospectively analyzed all pediatric renal transplant recipients performed by a single surgeon at our center between January 2015 and June 2022. Donor and recipient demographics, intraoperative data, and recipient outcomes were included. Recipients were divided into two groups based on SRA vs. MRA. Baseline variables were described using frequency distributions for categorical variables and means and standard errors for continuous variables. Comparisons of those distributions between the two groups were performed using standard chi-squared and t-tests. Time-to-event distributions were compared using the log-rank test.ResultsForty-nine pediatric transplant recipients were analyzed. Of these, 9 had donors with MRA (Group 1) and 40 had donors with SRA (Group 2). Native kidney and liver mobilization was performed in 44.4% (4/9) of Group 1 vs. 60.0% (24/40) of Group 2 cases (p = 0.39). There were no cases of delayed graft function or graft primary nonfunction. No surgical drainage or ureteral stents were used in any of the cases. One patient in Group 2 developed a distal ureter stricture. The geometric mean serum creatinine at 6- and 12-months posttransplant was 0.7 */ 1.2 and 0.9 */ 1.2 mg/dl in Group 1 and 0.7 */ 1.1 and 0.7 */ 1.1 mg/dl in Group 2. Two death-censored graft failures were observed in Group 2, with no significant difference observed between the two groups (p = 0.48).ConclusionsOur study demonstrates that pediatric renal transplantation with MRA grafts, using a surgical approach to achieve a single renal artery ostium, can be safely performed while achieving similar outcomes as SRA grafts and with a low complication rate

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Gold nanoparticle-enhanced X-ray microtomography of the rodent reveals region-specific cerebrospinal fluid circulation in the brain

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    Cerebrospinal fluid (CSF) is essential for the development and function of the central nervous system (CNS). However, the brain and its interstitium have largely been thought of as a single entity through which CSF circulates, and it is not known whether specific cell populations within the CNS preferentially interact with the CSF. Here, we develop a technique for CSF tracking, gold nanoparticle-enhanced X-ray microtomography, to achieve micrometer-scale resolution visualization of CSF circulation patterns during development. Using this method and subsequent histological analysis in rodents, we identify previously uncharacterized CSF pathways from the subarachnoid space (particularly the basal cisterns) that mediate CSF-parenchymal interactions involving 24 functional-anatomic cell groupings in the brain and spinal cord. CSF distribution to these areas is largely restricted to early development and is altered in posthemorrhagic hydrocephalus. Our study also presents particle size-dependent CSF circulation patterns through the CNS including interaction between neurons and small CSF tracers, but not large CSF tracers. These findings have implications for understanding the biological basis of normal brain development and the pathogenesis of a broad range of disease states, including hydrocephalus

    Anterior colporrhaphy does not induce bladder outlet obstruction

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    We aimed to evaluate if anterior colporrhaphy causes incomplete voiding due to bladder outlet obstruction. Women scheduled for anterior colporrhaphy were asked to undergo multichannel urodynamic investigation before surgery and the first postoperative day. Bladder outlet obstruction was assessed using the Blaivas-Groutz voiding nomogram. Maximum flow rate, detrusor pressure and residual volume were compared between pre- and postoperative measurements and between women with and without an abnormal post-void residual volume (PVR; volume exceeding 150 ml). Seventeen women participated. One woman who was unobstructed before surgery was obstructed after surgery. Overall, detrusor pressure and maximum flow rate before and after surgery did not differ. After surgery, six women had an abnormal PVR, one was unable to void, four were mildly obstructed and one moderately obstructed. Urodynamic investigation the first day after anterior colporrhaphy did not show that anterior colporrhaphy induces bladder outlet obstruction. The explanation for postoperative urinary retention can therefore also lie in non-anatomical causes such as postoperative pain and psychological factor
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