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排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
S J Virk F X Qiang N H Anfilogoff R G Murray W A Littler M K Davies 《The American journal of cardiology》1991,67(12):48C-52C; discussion 52C-54C
Xamoterol, a new beta 1 partial agonist, has the potential to modulate cardiac response to variations in sympathetic tone in patients with heart failure. Its properties should result in beta-receptor stimulatory effects at low levels of sympathetic tone and beta-receptor protective effects at higher levels of sympathetic tone. The acute effects of intravenous (i.v.) xamoterol on hemodynamics at rest and during exercise were studied in 30 patients with mild to moderate heart failure (13 patients in New York Heart Association class II; 17 in class III) due to ischemic (n = 24) or cardiomyopathic (n = 6) heart disease. Cardiac index, stroke volume and stroke work index at rest were significantly improved after i.v. administration of xamoterol and consistent with net agonist effects. During exercise, heart rate and double product were significantly reduced (net antagonist effects), but with preservation of the expected increases in cardiac index and systolic blood pressure. These hemodynamic findings confirm the ability of xamoterol to modulate cardiac response to variations in sympathetic tone. Tachyphylaxis and arrhythmogenicity limit the chronic use of drugs with full beta-agonist properties as positive inotropes in heart failure. The patients were therefore entered into a 6-month double-blind, placebo-controlled, crossover study of chronic oral xamoterol therapy, 200 mg twice daily, and the hemodynamic responses to i.v. xamoterol were repeated at the end of the trial. No impairment in either resting or exercise effects was observed, indicative of a maintained response and absence of tachyphylaxis after chronic therapy. Furthermore, 24-hour ambulatory electrocardiographic monitoring showed no change in ventricular arrhythmias during oral treatment.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
Herremans Kelly M. Cribbin Morgan P. Riner Andrea N. Neal Dan W. Hollen Tracy L. Clevenger Pamela Munoz Derly Blewett Shannon Giap Fantine Okunieff Paul G. Mendenhall Nancy P. Bradley Julie A. Mendenhall William M. Mailhot-Vega Raymond B. Brooks Eric Daily Karen C. Heldermon Coy D. Marshall Julia K. Hanna Mariam W. Leyngold Mark M. Virk Sarah S. Shaw Christiana M. Spiguel Lisa R. 《Annals of surgical oncology》2021,28(10):5775-5787
Annals of Surgical Oncology - Breast cancer-related lymphedema (BCRL) is a source of postoperative morbidity for breast cancer survivors. Lymphatic microsurgical preventive healing approach... 相似文献
3.
Sohrab Virk Kathleen N. Meyers Virginie Lafage Suzanne A. Maher Tony Chen 《The spine journal》2021,21(4):698-707
Background ContextAnnular repair devices offer a solution to recurrent disc herniations by closing an annular defect and lowering the risk of reherniation. Given the significant risk of neurologic injury from device failure it is imperative that a reliable preclinical model exists to demonstrate a high load to failure for the disc repair devices.PurposeTo establish a preclinical model for disc herniation and demonstrate how changes in species, intervertebral disc height and Pfirrmann classification impacts failure load on an injured disc. We hypothesized that: (1) The force required for disc herniation would be variable across disc morphologies and species, and (2) for human discs the force to herniation would inversely correlate with the degree of disc degeneration.Study designAnimal and human cadaveric biomechanical model of disc herniation.MethodsWe tested calf lumbar spines, bovine tail segments and human lumbar spines. We first divided individual lumbar or tail segments to include the vertebral bodies and disc. We then hydrated the specimens by placing them in a saline bath overnight. A magnetic resonance images were acquired from human specimens and a Pfirrmann classification was made. A stab incision measuring 25% of the diameter of the disc was then done to each specimen along the posterior intervertebral disc space. Each specimen was placed in custom test fixtures on a servo-hydraulic test frame (MTS, Eden Prarie, MN) such that the superior body was attached to a 10,000 lb load cell and the inferior body was supported on the piston. A compressive ramping load was placed on the specimen in load control at 4 MPa/sec stopping at 75% of the disc height. Load was recorded throughout the test and failure load calculated. Once the test was completed each specimen was sliced through the center of the disc and photos were taken of the cut surface.ResultsFifteen each of calf, human, and bovine tail segments were tested. The failure load varied significantly between specimens (p<.001) with human specimens having the highest average failure load (8154±2049 N). Disc height was higher for lumbar/bovine tail segments as compared to calf specimens (p<.001) with bovine tails having the highest disc height (7.1±1.7 mm). Similarly, human lumbar discs had a cross sectional area that was greater than both bovine tail/calf lumbar spines (p<.001). There was no correlation between disc height and failure load within each individual species (p>.05). Cross sectional area and failure load did not correlate with failure load for human lumbar spine and bovine tails (p>.05) but did correlate with calf spine (r=0.53, p=.04). There was a statistically significant inverse correlation between disc height and Pfirrmann classification for human lumbar spines (r=?0.84, p<.001). There was also a statistically significant inverse relationship between Pfirrmann classification and failure load (r=?0.58, p=.02).ConclusionsWe have established a model for disc herniation and have shown how results of this model vary between species, disc morphology, and Pfirrmann classification. Both hypotheses were accepted: The force required for disc herniation was variable across species, and the force to herniation for human spines was inversely correlated with the degree of disc degeneration. We recommend that models using human intervertebral discs should include data on Pfirrmann classification, while biomechanical models using calf spines should report cross sectional area. Failure loads do not vary based on dimensions for bovine tails.Clinical SignificanceOur analysis of models for disc herniation will allow for quicker, reliable comparisons of failure forces required to induce a disc herniation. Future work with these models may facilitate rapid testing of devices to repair a torn/ruptured annulus. 相似文献
4.
Surinder K. Singhal Ramandeep S. Virk Arjun Dass Bimaljit Singh Sandhu 《Indian journal of otolaryngology and head and neck surgery》2006,58(3):300-302
Tracheoesophageal fistula is a life threatening condition. Patients not managed surgically ultimately die of their disease.
Surgical management is the treatment of choice. We present a case of a patient that developed a tracheoesophageal fistula
after tracheostomy. Surgical repair was done which failed due to infection. The patient was managed with the help of an esophageal
stent and Trichloroacetic Acid cautery. This approach can be used in selected patients, depending upon the size and site of
TEE Larger fistulae and those situated lower down e.g. supra carinal cannot be managed by this technique. 相似文献
5.
6.
Lila J. Finney Rutten Xuan Zhu Aaron L. Leppin Jennifer L. Ridgeway Melanie D. Swift Joan M. Griffin Jennifer L. St Sauver Abinash Virk Robert M. Jacobson 《Mayo Clinic proceedings. Mayo Clinic》2021,96(3):699-707
The success of vaccination programs is contingent upon irrefutable scientific safety data combined with high rates of public acceptance and population coverage. Vaccine hesitancy, characterized by lack of confidence in vaccination and/or complacency about vaccination that may lead to delay or refusal of vaccination despite the availability of services, threatens to undermine the success of coronavirus disease 2019 (COVID-19) vaccination programs. The rapid pace of vaccine development, misinformation in popular and social media, the polarized sociopolitical environment, and the inherent complexities of large-scale vaccination efforts may undermine vaccination confidence and increase complacency about COVID-19 vaccination. Although the experience of recent lethal surges of COVID-19 infections has underscored the value of COVID-19 vaccines, ensuring population uptake of COVID-19 vaccination will require application of multilevel, evidence-based strategies to influence behavior change and address vaccine hesitancy. Recent survey research evaluating public attitudes in the United States toward the COVID-19 vaccine reveals substantial vaccine hesitancy. Building upon efforts at the policy and community level to ensure population access to COVID-19 vaccination, a strong health care system response is critical to address vaccine hesitancy. Drawing on the evidence base in social, behavioral, communication, and implementation science, we review, summarize, and encourage use of interpersonal, individual-level, and organizational interventions within clinical organizations to address this critical gap and improve population adoption of COVID-19 vaccination. 相似文献
7.
Virk Zain M. Song Andrew B. Badran Yousef R. Al-Samkari Hanny 《Journal of thrombosis and thrombolysis》2022,54(2):255-259
Journal of Thrombosis and Thrombolysis - Heyde syndrome is characterized by the co-occurrence of aortic stenosis and bleeding gastrointestinal angiodysplasias, often with acquired von Willebrand... 相似文献
8.
Cathy A. Goldstein Hala Karnib Katherine Williams Zunaira Virk Afifa Shamim-Uzzaman 《Sleep & breathing》2018,22(3):641-651
Purpose
Home sleep apnea tests (HSATs) are an alternative to attended polysomnograms (PSGs) when the pre-test probability for moderate to severe OSA is high. However, insurers often mandate use anytime OSA is suspected regardless of the pre-test probability. Our objective was to determine the ability of HSATs to rule in OSA when the pre-test probability of an apnea hypopnea index (AHI) in the moderate to severe range is low.Methods
Patients who underwent HSATs were characterized as low or high pre-test probability based on the presence of two symptoms of the STOP instrument plus either BMI >?35 or male gender. The odds of HSAT diagnostic for OSA dependent on pre-test probability was calculated. Stepwise selection determined predictors of non-diagnostic HSAT. As PSG is performed after HSATs that do not confirm OSA, false negative results were assessed.Results
Among 196 individuals, pre-test probability was low in 74 (38%) and high in 122 (62%). A lower percentage of individuals with a low versus high pre-test probability for moderate to severe OSA had HSAT results that confirmed OSA (61 versus 84%, p?=?0.0002) resulting in an odds ratio (OR) of 0.29 for confirmatory HSAT in the low pre-test probability group (95% CI [0.146, 0.563]). Multivariate logistic regression demonstrated that age ≤?50 (OR 3.10 [1.24–7.73]), female gender (OR 3.58[1.50–8.66]), non-enlarged neck circumference (OR 11.50 [2.50–52.93]), and the absence of loud snoring (OR 3.47 [1.30–9.25]) best predicted non-diagnostic HSAT. OSA was diagnosed by PSG in 54% of individuals with negative HSAT which was similar in both pre-test probability groups.Conclusion
HSATs should be reserved for individuals with high pre-test probability for moderate to severe disease as opposed to any individual with suspected OSA.9.
AXIN2 expression predicts prostate cancer recurrence and regulates invasion and tumor growth 下载免费PDF全文
Brian R. Hu Adrian S. Fairey Anisha Madhav Dongyun Yang Meng Li Susan Groshen Craig Stephens Philip H. Kim Navneet Virk Lina Wang Sue Ellen Martin Nicholas Erho Elai Davicioni Robert B. Jenkins Robert B. Den Tong Xu Yucheng Xu Inderbir S. Gill David I. Quinn Amir Goldkorn 《The Prostate》2016,76(6):597-608
10.