1,522 research outputs found
Agonist-Specific Calcium Signaling and Phosphoinositide Hydrolysis in Human SK-N-MCIXC Neuroepithelioma Cells
Fura-2 digital imaging microfluorimetry was used to evaluate the Ca 2+ signals generated in single clonal human neuroepithelioma cells (SK-N-MCIXC) in response to agonists that stimulate phosphoinositide hydrolysis. Addition of optimal concentrations of either endothelin-1 (ET-1), ATP, oxotremorine-M (Oxo-M), or norepinephrine (NE) all resulted in an increase in the concentration of cytosolic calcium (Ca 2+ i ) but of different magnitudes (ET-1 = ATP> NE). The Ca 2+ signals elicited by the individual agonists also differed from each other in terms of their latency of onset, rate of rise and decay, and prevalence of a sustained phase of Ca 2+ influx. The Ca 2+ signals that occurred in response to ATP had a shorter latency and more rapid rates of rise and decay than those observed for the other three agonists. Furthermore, a sustained plateau phase of the Ca 2+ signal, which was characteristic of the response to Oxo-M, was observed in 94% of cells responded to ET-1 or ATP, whereas corresponding values for Oxo-M and NE were ∼74 and ∼48%. Sequential addition of agonists to cells maintained in a Ca 2+ -free buffer indicated that each ligand mobilized Ca 2+ from a common intracellular pool. When monitored as a release of a total inositol phosphate fraction, all four agonists elicited similar (four- to sixfold) increases in phosphoinositide hydrolysis. However, the addition of ET-1 or ATP resulted in larger increases in the net formation of inositol 1,4,5-trisphosphate than did either Oxo-M or NE. These results indicate that, in SK-N-MCIXC cells, the characteristics of both Ca 2+ signaling and inositol phosphate production are agonist specific.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66414/1/j.1471-4159.1994.63062099.x.pd
A function for binaural integration in auditory grouping and segregation in the inferior colliculus
Responses of neurons to binaural, harmonic complex stimuli in urethane-anesthetized guinea pig inferior colliculus (IC) are reported. To assess the binaural integration of harmonicity cues for sound segregation and grouping, responses were measured to harmonic complexes with different fundamental frequencies presented to each ear. Simultaneously gated harmonic stimuli with fundamental frequencies of 125 Hz and 145 Hz were presented to the left and right ears, respectively, and recordings made from 96 neurons with characteristic frequencies >2 kHz in the central nucleus of the IC. Of these units, 70 responded continuously throughout the stimulus and were excited by the stimulus at the contralateral ear. The stimulus at the ipsilateral ear excited (EE: 14%; 10/70), inhibited (EI: 33%; 23/70), or had no significant effect (EO: 53%; 37/70), defined by the effect on firing rate. The neurons phase locked to the temporal envelope at each ear to varying degrees depending on signal level. Many of the cells (predominantly EO) were dominated by the response to the contralateral stimulus. Another group (predominantly EI) synchronized to the contralateral stimulus and were suppressed by the ipsilateral stimulus in a phasic manner. A third group synchronized to the stimuli at both ears (predominantly EE). Finally, a group only responded when the waveform peaks from each ear coincided. We conclude that these groups of neurons represent different “streams” of information but exhibit modifications of the response rather than encoding a feature of the stimulus, like pitch
Drug-reinforced responding: rapid determination of dose-response functions
Rhesus monkeys were conditioned to press on levers and receive intravenous infusions of cocaine or ketamine. Experimental conditions provided several different doses of drug during each of two daily 130 min sessions; as a result, a doseresponse curve relating rate of responding to dose/injection for self-administered drug was obtained within each session. Relative rate-maintaining effects of nomifensine and cocaine in monkeys on baseline conditions of cocaine self-administration, and rate-maintaining effects of ketamine, phencyclidine and MK-801 in monkeys on baseline conditions of ketamine self-administration, compared favorably with relative rate-maintaining effects of these substances obtained in more traditional paradigms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27725/1/0000117.pd
Safety Profile of Gutless Adenovirus Vectors Delivered into the Normal Brain Parenchyma: Implications for a Glioma Phase 1 Clinical Trial
Abstract Adenoviral vectors (Ads) have been evaluated in clinical trials for glioma. However, systemic immunity against the vectors can hamper therapeutic efficacy. We demonstrated that combined immunostimulation and cytotoxic gene therapy provides long-term survival in preclinical glioma models. Because helper-dependent high-capacity Ads (HC-Ads) elicit sustained transgene expression, in the presence of antiadenoviral immunity, we engineered HC-Ads encoding conditional cytotoxic herpes simplex type 1 thymidine kinase and immunostimulatory cytokine Fms-like tyrosine kinase ligand-3 under the control of the TetOn system. Escalating doses of combined HC-Ads (1?108, 1?109, and 1?1010 viral particles [VP]) were delivered into the rat brain. We assessed neuropathology, biodistribution, transgene expression, systemic toxicity, and behavioral impact at acute and chronic time points after vector delivery. Histopathological analysis did not reveal any evidence of toxicity or long-term inflammation at the lower doses tested. Vector genomes were restricted to the injection site. Serum chemistry did not uncover adverse systemic side effects at any of the doses tested. Taken together, our data indicate that doses of up to 1?109 VP of each HC-Ad can be safely administered into the normal brain. This comprehensive toxicity and biodistribution study will lay the foundations for implementation of a phase 1 clinical trial for GBM using HC-Ads.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98452/1/hgtb%2E2012%2E060.pd
Trial of Ultrasound guided carpal tunnel release versus Traditional Open Release (TUTOR)
BACKGROUND: Carpal tunnel release (CTR) is a surgical treatment option for patients with carpal tunnel syndrome (CTS) symptoms that are unresponsive to conservative treatment. Most patients experience symptomatic relief after CTR regardless of the surgical technique. However, direct comparisons of the safety and effectiveness between CTR surgical techniques are limited. The purpose of this randomized controlled trial is to compare the safety and effectiveness of CTR with ultrasound guidance (CTR-US) versus mini-open CTR (mOCTR) in subjects with symptomatic CTS.
DESIGN AND METHODS: TUTOR (Trial of Ultrasound guided CTR versus Traditional Open Release) is a randomized controlled trial in which 120 subjects at up to 12 sites in the United States will be randomized (2:1) to receive CTR-US or mOCTR. The primary endpoint of the study is the percentage of patients who return to normal daily activities within 3 days of the procedure. Secondary endpoints of the study are median time to return to normal daily activities, percentage of patients who return to work within 3 days of the procedure, median time to return to work, Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS) change score at 3 months, BCTQ Functional Status Scale (BCTQ-FSS) change score at 3 months, Numeric Pain Scale change score at 3 months, EuroQoL-5 Dimension 5-Level (EQ-5D-5L) change score at 3 months, and the incidence of device- or procedure-related adverse events at 3 months. Patient follow-up in this trial will continue for 1 year.
ETHICS AND DISSEMINATION: This study was approved by a central institutional review board and ongoing trial oversight will be provided by a data safety monitoring board (DSMB). The authors intend to report the results of this trial at medical conferences and peer-reviewed journals. The outcomes of TUTOR will have important clinical and economic implications for all stakeholders involved in treating patients with CTS.
STUDY REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov): NCT05405218.
LEVEL OF EVIDENCE: 1
Multicenter randomized trial of carpal tunnel release with ultrasound guidance versus mini-open technique
BACKGROUND: Comparative studies of carpal tunnel release with ultrasound guidance (CTR-US) vs. mini-open CTR (mOCTR) are limited, prompting development of this randomized trial to compare efficacy and safety of these techniques.
RESEARCH DESIGN AND METHODS: Patients were randomized (2:1) to CTR-US or mOCTR, treated by experienced hand surgeons (median previous cases: 12 CTR-US; 1000 mOCTR), and followed for 3 months.
RESULTS: Among 149 randomized patients, 122 received CTR-US (
CONCLUSIONS: The efficacy and safety of CTR-US were comparable to mOCTR despite less previous surgical experience with CTR-US. The choice of CTR technique should be determined by shared decision-making between patient and physician.
CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifier is NCT05405218
X-ray absorption spectroscopy systematics at the tungsten L-edge
A series of mononuclear six-coordinate tungsten compounds spanning formal oxidation states from 0 to +VI, largely in a ligand environment of inert chloride and/or phosphine, has been interrogated by tungsten L-edge X-ray absorption spectroscopy. The L-edge spectra of this compound set, comprised of [W<sup>0</sup>(PMe<sub>3</sub>)<sub>6</sub>], [W<sup>II</sup>Cl<sub>2</sub>(PMePh<sub>2</sub>)<sub>4</sub>], [W<sup>III</sup>Cl<sub>2</sub>(dppe)<sub>2</sub>][PF<sub>6</sub>] (dppe = 1,2-bis(diphenylphosphino)ethane), [W<sup>IV</sup>Cl<sub>4</sub>(PMePh<sub>2</sub>)<sub>2</sub>], [W<sup>V</sup>(NPh)Cl<sub>3</sub>(PMe<sub>3</sub>)<sub>2</sub>], and [W<sup>VI</sup>Cl<sub>6</sub>] correlate with formal oxidation state and have usefulness as references for the interpretation of the L-edge spectra of tungsten compounds with redox-active ligands and ambiguous electronic structure descriptions. The utility of these spectra arises from the combined correlation of the estimated branching ratio (EBR) of the L<sub>3,2</sub>-edges and the L<sub>1</sub> rising-edge energy with metal Z<sub>eff</sub>, thereby permitting an assessment of effective metal oxidation state. An application of these reference spectra is illustrated by their use as backdrop for the L-edge X-ray absorption spectra of [W<sup>IV</sup>(mdt)<sub>2</sub>(CO)<sub>2</sub>] and [W<sup>IV</sup>(mdt)<sub>2</sub>(CN)<sub>2</sub>]<sup>2–</sup> (mdt<sup>2–</sup> = 1,2-dimethylethene-1,2-dithiolate), which shows that both compounds are effectively W<sup>IV</sup> species. Use of metal L-edge XAS to assess a compound of uncertain formulation requires: 1) Placement of that data within the context of spectra offered by unambiguous calibrant compounds, preferably with the same coordination number and similar metal ligand distances. Such spectra assist in defining upper and/or lower limits for metal Z<sub>eff</sub> in the species of interest; 2) Evaluation of that data in conjunction with information from other physical methods, especially ligand K-edge XAS; 3) Increased care in interpretation if strong π-acceptor ligands, particularly CO, or π-donor ligands are present. The electron-withdrawing/donating nature of these ligand types, combined with relatively short metal-ligand distances, exaggerate the difference between formal oxidation state and metal Z<sub>eff</sub> or, as in the case of [W<sup>IV</sup>(mdt)<sub>2</sub>(CO)<sub>2</sub>], add other subtlety by modulating the redox level of other ligands in the coordination sphere
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Erratum: Sequence data and association statistics from 12,940 type 2 diabetes cases and controls.
This corrects the article DOI: 10.1038/sdata.2017.179
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