2,346 research outputs found
Determination of Anaerobic Threshold by Heart Rate or Heart Rate Variability using Discontinuous Cycle Ergometry
International Journal of Exercise Science 7(1) : 45-53, 2014. The purpose was to determine if heart rate (HR) and heart rate variability (HRV) responses would reflect anaerobic threshold (AT) using a discontinuous, incremental, cycle test. AT was determined by ventilatory threshold (VT). Cyclists (30.6±5.9y; 7 males, 8 females) completed a discontinuous cycle test consisting of 7 stages (6 min each with 3 min of rest between). Three stages were performed at power outputs (W) below those corresponding to a previously established AT, one at W corresponding to AT, and 3 at W above those corresponding to AT. The W at the intersection of the trend lines was considered each metricâs âthresholdâ. The averaged stage data for Ve, HR, and time- and frequency-domain HRV metrics were plotted versus W. The W at the âthresholdâ for the metrics of interest were compared using correlation analysis and paired-sample t-test. In all, several heart rate-related parameters accurately reflected AT with significant correlations (pâ€0.05) were observed between AT W and HR, mean RR interval (MRR), low and high frequency spectral energy (LF and HR, respectively), high frequency peak (fHF), and HFxfHF metricsâ threshold W (i.e., MRRTW, etc.). Differences in HR or HRV metric threshold W and AT for all subjects were less than 14 W. The steady state data from discontinuous protocols may allow for a true indication of steady-state physiologic stress responses and corresponding W at AT, compared to continuous protocols using 1-2 min exercise stages
Observation of Scarred Modes in Asymmetrically Deformed Microcylinder Lasers
We report observation of lasing in the scarred modes in an asymmetrically
deformed microcavity made of liquid jet. The observed scarred modes correspond
to morphology-dependent resonance of radial mode order 3 with their Q values in
the range of 10^6. Emission directionality is also observed, corresponding to a
hexagonal unstable periodic orbit.Comment: 4 pages, 6 figure
Random telegraph noise in metallic single-walled carbon nanotubes
We have investigated random telegraph noise (RTN) observed in individual
metallic carbon nanotubes (CNTs). Mean lifetimes in high- and low-current
states, shigh and slow, have been studied as a function of bias-voltage and
gate-voltage as well as temperature. By analyzing the statistics and features
of the RTN, we suggest that this noise is due to the random transition of
defects between two metastable states, activated by inelastic scattering with
conduction electrons. Our results indicate an important role of defect motions
in the 1=f noise in CNTs.Comment: 4 page
Primary Culture of Central Neurocytoma: A Case Report
A seventeen-year-old female patient was admitted with sudden-onset of headache and vomiting. Brain magnetic resonance imaging demonstrated a heterogeneously enhancing tumour in the left lateral ventricle. The tumour was removed and confirmed as a central neurocytoma (CN). For the residual tumour in the left lateral ventricle, gamma knife stereotactic radiosurgery was done at fifteen months after the initial surgery. Tumour recurred in the 4th ventricle at 5 yr after initial surgery. The tumour was removed and proved as a CN. In vitro primary culture was done with both tumours obtained from the left lateral ventricle and the 4th ventricle, respectively. Nestin, a neuronal stem cell marker was expressed in reverse Transcriptase-Polymerase Chain Reaction of both tumors. Both tumours showed different morphology and phenotypes of neuron and glia depending on the culture condition. When cultured in insulin, transferrin selenium and fibronectin media with basic fibroblast growth factors, tumour cells showed neuronal morphology and phenotypes. When cultured in the Dulbeco's Modified Essential Media with 20% fetal bovine serum, tumors cells showed glial morphology and phenotypes. It is suggested that CN has the characteristics of neuronal stem cells and potential to differentiate into mature neuron and glial cells depending on the environmental cue
Intravitreally injected anti-VEGF antibody reduces brown fat in neonatal mice
Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondriarelated genes, Ppargc1a and Ucp1, all of which are characteristics of "whitening" of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants. Copyright
Clinical characteristics of apixaban prescription in AF patients with single dose-reduction criterion: the ASPIRE (efficAcy and safety of aPixaban in rEal-world practice in Korean frail patients with atrial fibrillation) study
BackgroundData on off-label reduced dose risk among patients with atrial fibrillation (AF) who qualify for a single-dose reduction of apixaban is scarce.ObjectivesWe prospectively assessed apixaban dosing and clinical characteristics in AF patients meeting a dose reduction criterion.MethodsThe multicentre, prospective cohort study, the efficAcy and Safety of aPixaban In REal-world practice in Korean frail patients with AF (ASPIRE), encompasses patients with AF who met the criteria for a single-dose reduction of apixaban and were given varying doses of apixaban, either the on-label standard dose or the off-label reduced dose.ResultsOf 2,000 patients (mean age 74.3â±â7.9 years, 55.8% women), 29.7% were â„80 years, 62.6% weighed â€60â
kg, and 7.8% had serum creatinine â„1.5â
mg/dL. Of these, 51.3% were prescribed an off-label reduced dose of apixaban. The off-label group was characterized with older age, more comorbidities, and antiplatelet agents, while the on-label group had more prior strokes. Physicians preferred off-label reduced dose in the âmarginal zone,â defined as age 75â80 years, weight 60â65â
kg, and creatinine levels 1.2â1.5â
mg/dL.ConclusionsIn real-world clinical setting of the Korean population, off-label reduced dose apixaban was administered to nearly half of the patients who qualified for a single dose reduction. This reduced dosage was more commonly prescribed to patients with frail characteristics, while patients with a history of stroke were more often given the standard dose as per the label. A future study is planned to contrast the safety and effectiveness of the standard dose against the reduced dose of apixaban in this population
Treatment strategy and outcomes in locally advanced head and neck squamous cell carcinoma: a nationwide retrospective cohort study (KCSG HN13â01)
Abstract
Background
By investigating treatment patterns and outcomes in locally advanced head and neck squamous cell carcinoma (LA-HNSCC), we aimed at providing valuable insights into the optimal therapeutic strategy for physicians in real-world practice.
Methods
This is a multi-institutional study enrolled the patients with stage III to IVB LA-HNSCC, except for nasopharyngeal carcinoma, from 2004 to 2015 in thirteen referral hospitals capable of multidisciplinary care.
Results
A total of 445 LA-HNSCC patients were analyzed. The median age was 61âyears (range, 24â89). The primary tumor location was the oropharynx in 191 (43%), oral cavity in 106 (24%), hypopharynx in 64 (14%), larynx in 57 (13%) and other sites in 27 (6%). The most common stage was T2 in 172 (39%), and N2 in 245 (55%). Based on treatment intents, 229 (52%) of the patients received definitive concurrent chemoradiotherapy (CCRT) and 187 (42%) underwent surgery. Approximately 158 (36%) of the study population received induction chemotherapy (IC). Taken together, 385 (87%) of the patients underwent combined therapeutic modalities. The regimen for definitive CCRT was weekly cisplatin in 58%, 3-weekly cisplatin in 28% and cetuximab in 3%. The preferred regimen for IC was docetaxel with cisplatin in 49%, and docetaxel, cisplatin plus fluorouracil in 27%. With a median follow-up of 39âmonths, one-year and two-year survival rates were 89 and 80%, respectively. Overall survival was not significantly different between CCRT and surgery group (pâ=â0.620).
Conclusions
In patients with LA-HNSCC, the majority of patients received combined therapeutic modalities. Definitive CCRT, IC then definitive CCRT, and surgery followed by adjuvant CCRT or radiotherapy are the preferred multidisciplinary strategies in real-world practice
Direct Measurement of ATP7B Peptides Is Highly Effective in the Diagnosis of Wilson Disease
Background & Aims: Both existing clinical criteria and genetic testing have significant limitations for the diagnosis of Wilson disease (WD), often creating ambiguities in patient identification and leading to delayed diagnosis and ineffective management. ATP7B protein concentration, indicated by direct measurement of surrogate peptides from patient dried blood spot samples, could provide primary evidence of WD. ATP7B concentrations were measured in patient samples from diverse backgrounds, diagnostic potential is determined, and results are compared with biochemical and genetic results from individual patients. Methods: Two hundred and sixty-four samples from biorepositories at 3 international and 2 domestic academic centers and 150 normal controls were obtained after Institutional Review Board approval. Genetically or clinically confirmed WD patients with a Leipzig score >3 and obligate heterozygote (carriers) from affected family members were included. ATP7B peptide measurements were made by immunoaffinity enrichment mass spectrometry. Results: Two ATP7B peptides were used to measure ATP7B protein concentration. Receiver operating characteristics curve analysis generates an area under the curve of 0.98. ATP7B peptide analysis of the sequence ATP7B 887 was found to have a sensitivity of 91.2%, specificity of 98.1%, positive predictive value of 98.0%, and a negative predictive value of 91.5%. In patients with normal ceruloplasmin concentrations (>20 mg/dL), 14 of 16 (87.5%) were ATP7B-deficient. In patients without clear genetic results, 94% were ATP7B-deficient. Conclusions: Quantification of ATP7B peptide effectively identified WD patients in 92.1% of presented cases and reduced ambiguities resulting from ceruloplasmin and genetic analysis. Clarity is brought to patients with ambiguous genetic results, significantly aiding in noninvasive diagnosis. A proposed diagnostic score and algorithm incorporating ATP7B peptide concentrations can be rapidly diagnostic and supplemental to current Leipzig scoring systems
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