236 research outputs found

    Effect of renal shock wave lithotripsy on the development of metabolic syndrome in a juvenile swine model: a pilot study

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    PURPOSE: We performed a pilot study to assess whether renal shock wave lithotripsy influences metabolic syndrome onset and severity. MATERIALS AND METHODS: Three-month-old juvenile female Ossabaw miniature pigs were treated with shock wave lithotripsy (2,000 shock waves at 24 kV with 120 shock waves per minute in 2) or sham shock wave lithotripsy (no shock waves in 2). Shock waves were targeted to the upper pole of the left kidney to model treatment that would also expose the pancreatic tail to shock waves. Pigs were then instrumented to directly measure arterial blood pressure via an implanted radiotelemetry device. They later received a hypercaloric atherogenic diet for about 7 months. Metabolic syndrome development was assessed by the intravenous glucose tolerance test. RESULTS: Metabolic syndrome progression and severity were similar in the sham treated and lithotripsy groups. The only exception arterial blood pressure, which remained relatively constant in sham treated pigs but began to increase at about 2 months towards hypertensive levels in lithotripsy treated pigs. Metabolic data on the 2 groups were pooled to provide a more complete assessment of metabolic syndrome development and progression in this juvenile pig model. The intravenous glucose tolerance test revealed substantial insulin resistance with impaired glucose tolerance within 2 months on the hypercaloric atherogenic diet with signs of further metabolic impairment at 7 months. CONCLUSIONS: These preliminary results suggest that renal shock wave lithotripsy is not a risk factor for worsening glucose tolerance or diabetes mellitus onset. However, it appears to be a risk factor for early onset hypertension in metabolic syndrome

    Shock wave lithotripsy targeting of the kidney and pancreas does not increase the severity of metabolic syndrome in a porcine model

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    PURPOSE: We determined whether shock wave lithotripsy of the kidney of pigs with metabolic syndrome would worsen glucose tolerance or increase the risk of diabetes mellitus. MATERIALS AND METHODS: Nine-month-old female Ossabaw miniature pigs were fed a hypercaloric atherogenic diet to induce metabolic syndrome. At age 15 months the pigs were treated with 2,000 or 4,000 shock waves (24 kV at 120 shock waves per minute) using an unmodified HM3 lithotripter (Dornier MedTech, Kennesaw, Georgia). Shock waves were targeted to the left kidney upper pole calyx to model treatment that would also expose the pancreatic tail to shock waves. The intravenous glucose tolerance test was done in conscious fasting pigs before lithotripsy, and 1 and 2 months after lithotripsy with blood samples taken for glucose and insulin measurement. RESULTS: Pigs fed the hypercaloric atherogenic diet were obese, dyslipidemic, insulin resistant and glucose intolerant, consistent with metabolic syndrome. Assessments of insulin resistance, glucose tolerance and pancreatic β cell function from fasting plasma glucose and insulin levels, and the glucose and insulin response profile to the intravenous glucose tolerance test were similar before and after lithotripsy. CONCLUSIONS: The metabolic syndrome status of pigs treated with shock wave lithotripsy was unchanged 2 months after kidney treatment with 2,000 high amplitude shock waves or overtreatment with 4,000 high amplitude shock waves. These findings do not support a single shock wave lithotripsy treatment of the kidney as a risk factor for the onset of diabetes mellitus

    Awakening, Efficacy, and Action: A Qualitative Inquiry of a Social Justiceâ Infused, Science Education Program

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    This article describes an innovative application of a social justiceâ infused pedagogy to an outâ ofâ school program for urban high school students. Using an interdisciplinary framework, the program featured a coherent synthesis of science, technology, engineering, and math (STEM) education, highlighting environmental and food justice perspectives; social justice education; and career and college planning. We used qualitative content analysis to analyze two separate interviews with six female and three male students of color ranging in age from 15 to 18 with an average age of 16.1 (SD=1.26) across an approximately 10â month time span. Utilizing a model of critical consciousness development as our organizing framework, we explored the studentsâ understanding of environmental and food justice issues. Participants indicated that they were actively engaged in learning about food and environmental justice, exploring STEM careers, and investigating the various ways that social justice is manifested in their lives. Implications for social justice and STEM education interventions as well as broader public policies are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141159/1/asap12136.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141159/2/asap12136_am.pd

    Comparison of Tissue Injury from Focused Ultrasonic Propulsion of Kidney Stones Versus Extracorporeal Shock Wave Lithotripsy

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    Purpose Focused ultrasonic propulsion is a new non-invasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, the extent of tissue injury associated with this technique is not known. As such, we quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions, and under conditions of higher power or continuous duty cycles, and compared those results to SWL injury. Materials and Methods A human calcium oxalate monohydrate stone and/or nickel beads were implanted (with ureteroscopy) into 3 kidneys of live pigs (45–55 kg) and repositioned using focused ultrasonic propulsion. Additional pig kidneys were exposed to SWL level pulse intensities or continuous ultrasound exposure of 10 minutes duration (ultrasound probe either transcutaneous or on the kidney). These kidneys were compared to 6 kidneys treated with an unmodified Dornier HM3 Lithotripter (2400 shocks, 120 SWs/min and 24 kV). Histological analysis was performed to assess the volume of hemorrhagic tissue injury created by each technique (% functional renal volume, FRV). Results SWL produced a lesion of 1.56±0.45% FRV. Ultrasonic propulsion produced no detectable lesion with the simulated clinical treatment. A lesion of 0.46±0.37% FRV or 1.15±0.49% FRV could be produced if excessive treatment parameters were used while the ultrasound probe was placed on the kidney. Conclusions Focused ultrasonic propulsion produced no detectable morphological injury to the renal parenchyma when using clinical treatment parameters and produced injury comparable in size to SWL when using excessive treatment parameters

    Single-mode instability in standing-wave lasers: The quantum cascade laser as a self-pumped parametric oscillator

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    We report the observation of a clear single-mode instability threshold in continuous-wave Fabry-Perot quantum cascade lasers (QCLs). The instability is characterized by the appearance of sidebands separated by tens of free spectral ranges (FSR) from the first lasing mode, at a pump current not much higher than the lasing threshold. As the current is increased, higher-order sidebands appear that preserve the initial spacing, and the spectra are suggestive of harmonically phase-locked waveforms. We present a theory of the instability that applies to all homogeneously broadened standing-wave lasers. The low instability threshold and the large sideband spacing can be explained by the combination of an unclamped, incoherent Lorentzian gain due to the population grating, and a coherent parametric gain caused by temporal population pulsations that changes the spectral gain line shape. The parametric term suppresses the gain of sidebands whose separation is much smaller than the reciprocal gain recovery time, while enhancing the gain of more distant sidebands. The large gain recovery frequency of the QCL compared to the FSR is essential to observe this parametric effect, which is responsible for the multiple-FSR sideband separation. We predict that by tuning the strength of the incoherent gain contribution, for example by engineering the modal overlap factors and the carrier diffusion, both amplitude-modulated (AM) or frequency-modulated emission can be achieved from QCLs. We provide initial evidence of an AM waveform emitted by a QCL with highly asymmetric facet reflectivities, thereby opening a promising route to ultrashort pulse generation in the mid-infrared. Together, the experiments and theory clarify a deep connection between parametric oscillation in optically pumped microresonators and the single-mode instability of lasers, tying together literature from the last 60 years.United States. Defense Advanced Research Projects Agency. Spectral Combs from UV to THz Program (Grant W31P4Q-16-1-0002)National Science Foundation (U.S.) (Awards ECCS-1230477, ECCS-1614631 and ECCS- 1614531)United States. Dept. of Defense. Assistant Secretary of Defense for Research & Engineering (Air Force Contracts FA8721-05-C- 0002 and No. FA8702-15-D-0001

    Return to Recreational Sports Participation Following Rotator Cuff Repair in Adults Over 40 Years of Age: Outcomes and Return to Play Analysis

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    Background: Despite the high prevalence of rotator cuff (RTC) tears in older adults, there is limited literature evaluating the return to recreational sport after repair. The purpose of this study was (1) to assess the patient-reported outcomes and return to sport rates following rotator cuff repair in patients aged more than 40 years with minimum 2-year follow-up; (2) to compare baseline, preoperative and postoperative outcomes, and level of play following repair of self-reported athletes with nonathletes; and (3) to compare return to sport rates in overhead athletes compared to nonoverhead athletes. Methods: Patients undergoing arthroscopic rotator cuff repair between January 2016 and January 2019 were screened for inclusion. Inclusion criteria included (1) age more than 40 years at the time of surgery, (2) arthroscopic repair of a full thickness RTC tear, and (3) preoperative American Shoulder and Elbow Surgeons score (ASES) available. Eligible patients were contacted and invited to fill out a custom return to sport and patient-reported outcome survey. Results: Overall, 375 of the 1141 eligible patients completed the survey instrument. There were 210 self- reported athletes (mean age 59.2 ± 9.55 years) and 165 nonathletes (mean age 62.0 ± 8.27 years) (P ¼ .003). Of the athletes, 193 (91.9%) returned to sport. The average age of athletes was 59.4 ± 9.33 years for those who returned to sport and 57.9 ± 12.0 years for those who did not (P ¼ .631). Athletes reported higher ASES scores than nonathletes both preoperatively (49.8 ± 20.3 vs. 44.8 ± 18.9, P ¼ .015) and postoperatively (87.6 ± 16.7 vs. 84.9 ± 17.5, P ¼ .036), but there was no difference in mean ASES improvement between groups (37.7 ± 23.0 vs. 40.3 ± 24.5, P ¼ .307). There was no difference in post- operative Single Assessment Numeric Evaluation scores when comparing self-reported athletes to nonathletes (85.4 ± 17.5 vs. 85.0 ± 18.7, P ¼ .836). After controlling for age, sex, body mass index, and smoking status using a multivariate analysis, there was no difference in mean ASES improvement when comparing athletes to nonathletes. Conclusion: There is a high rate of return to sport activities (\u3e 90%) in older adult recreational athletes following arthroscopic repair of full thickness RTC tears and rates of return to sport did not significantly differ for overhead and nonoverhead athletes. Self-reported athletes were noted to have higher baseline, preoperative, and postoperative ASES scores than nonathletes, but the mean ASES improvement following repair did not significantly differ between groups

    Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine.

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    OBJECTIVE: Circulatory shock is a life-threatening syndrome resulting in multiorgan failure and a high mortality rate. The aim of this consensus is to provide support to the bedside clinician regarding the diagnosis, management and monitoring of shock. METHODS: The European Society of Intensive Care Medicine invited 12 experts to form a Task Force to update a previous consensus (Antonelli et al.: Intensive Care Med 33:575-590, 2007). The same five questions addressed in the earlier consensus were used as the outline for the literature search and review, with the aim of the Task Force to produce statements based on the available literature and evidence. These questions were: (1) What are the epidemiologic and pathophysiologic features of shock in the intensive care unit ? (2) Should we monitor preload and fluid responsiveness in shock ? (3) How and when should we monitor stroke volume or cardiac output in shock ? (4) What markers of the regional and microcirculation can be monitored, and how can cellular function be assessed in shock ? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock ? Four types of statements were used: definition, recommendation, best practice and statement of fact. RESULTS: Forty-four statements were made. The main new statements include: (1) statements on individualizing blood pressure targets; (2) statements on the assessment and prediction of fluid responsiveness; (3) statements on the use of echocardiography and hemodynamic monitoring. CONCLUSIONS: This consensus provides 44 statements that can be used at the bedside to diagnose, treat and monitor patients with shock
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