Enteric neurotransmission is critical for coordinating motility throughout the gastrointestinal (GI) tract. However, there is considerable controversy regarding the cells that are responsible for the ...transduction of these neural inputs. In the present study, utilization of a cell‐specific calcium biosensor GCaMP6f, the spontaneous activity and neuroeffector responses of intramuscular ICC (ICC‐IM) to motor neural inputs was examined. Simultaneous intracellular microelectrode recordings and high‐speed video‐imaging during nerve stimulation was used to reveal the temporal relationship between changes in intracellular Ca2+ and post‐junctional electrical responses to neural stimulation. ICC‐IM were highly active, generating intracellular Ca2+‐transients that occurred stochastically, from multiple independent sites in single ICC‐IM. Ca2+‐transients were not entrained in single ICC‐IM or between neighbouring ICC‐IM. Activation of enteric motor neurons produced a dominant inhibitory response that abolished Ca2+‐transients in ICC‐IM. This inhibitory response was often preceded by a summation of Ca2+‐transients that led to a global rise in Ca2+. Individual ICC‐IM responded to nerve stimulation by a global rise in Ca2+ followed by inhibition of Ca2+‐transients. The inhibition of Ca2+‐transients was blocked by the nitric oxide synthase antagonist l‐NNA. The global rise in intracellular Ca2+ was inhibited by the muscarinic antagonist, atropine. Simultaneous intracellular microelectrode recordings with video‐imaging revealed that the rise in Ca2+ was temporally associated with rapid excitatory junction potentials and the inhibition of Ca2+‐transients with inhibitory junction potentials. These data support the premise of serial innervation of ICC‐IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach.
Key points
The cells responsible for mediating enteric neuroeffector transmission remain controversial. In the stomach intramuscular interstitial cells of Cajal (ICC‐IM) were the first ICC reported to receive cholinergic and nitrergic neural inputs.
Utilization of a cell specific calcium biosensor, GCaMP6f, the activity, and neuroeffector responses of ICC‐IM were examined. ICC‐IM were highly active, generating stochastic intracellular Ca2+‐transients.
Stimulation of enteric motor nerves abolished Ca2+‐transients in ICC‐IM. This inhibitory response was preceded by a global rise in intracellular Ca2+. Individual ICC‐IM responded to nerve stimulation with a rise in Ca2+ followed by inhibition of Ca2+‐transients.
Inhibition of Ca2+‐transients was blocked by the nitric oxide synthase antagonist l‐NNA. The global rise in Ca2+ was inhibited by the muscarinic antagonist atropine.
Simultaneous intracellular recordings with video imaging revealed that the global rise in intracellular Ca2+ and inhibition of Ca2+‐transients was temporally associated with rapid excitatory junction potentials followed by more sustained inhibitory junction potentials.
The data presented support the premise of serial innervation of ICC‐IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach.
figure legend
Intramuscular interstitial cells of Cajal (ICC‐IM) of the gastric fundus receive nitrergic inhibitory and cholinergic excitatory neuroeffector motor inputs. Using a genetically encoded calcium sensor we demonstrate that ICC‐IM are highly active cells generating stochastic intracellular Ca2+‐transients. Stimulation of enteric motor nerves abolished Ca2+‐transients in ICC‐IM, produced an inhibitory junction potential (IJP) and muscle relaxation that was mediated by nitric oxide (left hand side of figure). This inhibitory response was often preceded by a global rise in intracellular Ca2+ in ICC‐IM, a rapid excitatory junction potential (EJP) and muscle contraction that was mediated by acetylcholine (right hand side of figure). Individual ICC‐IM could respond to both excitatory and inhibitory neural inputs. These data support the premise of serial innervation of ICC‐IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach.
Abstract
Background and Aims
Ustekinumab is approved for the treatment of Crohn’s disease CD. Systematically registered prospective real-world data are scarce. We therefore aimed to study the ...effectiveness, safety and usage of ustekinumab for CD in everyday practice.
Methods
We prospectively enrolled CD patients initiating ustekinumab in regular care between December 2016 and January 2019. Clinical (Harvey Bradshaw Index HBI), biochemical (C-reactive protein CRP and faecal calprotectin FCP), extra-intestinal manifestations and, peri-anal fistula activity, ustekinumab dosage, concomitant medication use, and adverse events were documented at weeks 0, 12, 24, and 52. The primary outcome was corticosteroid-free clinical remission.
Results
In total, 221 CD patients were included (98.6% anti-tumour necrosis factor TNF and 46.6% vedolizumab exposed) with a median follow-up of 52.0 weeks interquartile range 49.3–58.4. Corticosteroid-free clinical remission rates at weeks 24 and 52 were 38.2% and 37.1%, respectively. An initial dosing schedule of 8 weeks, compared to 12 weeks, correlated with a lower discontinuation rate 20.0% vs 42.6%, p = 0.01, but comparable corticosteroid-free clinical remission at week 52 (46.3% q8w vs 34.6% q12w, p = 0.20). There was no clinical benefit of combination therapy after 52 weeks when compared to ustekinumab monotherapy combi 40.6% vs mono 36.0%, p = 0.64. At baseline, 28 patients had active peri-anal fistula, of whom 35.7% showed complete clinical resolution after 24 weeks. During follow-up we encountered six severe infections 3.5 per 100 patient-years, with all patients being on concomitant immunosuppressant therapies. Ustekinumab treatment discontinuation was observed in 75 33.9% patients mainly due to lack of response.
Conclusion
Ustekinumab is a relatively safe and effective treatment option for CD patients with prior failure of anti-TNF and anti-integrin therapies.
Repeatability (more precisely the common measure of repeatability, the intra‐class correlation coefficient, ICC) is an important index for quantifying the accuracy of measurements and the constancy ...of phenotypes. It is the proportion of phenotypic variation that can be attributed to between‐subject (or between‐group) variation. As a consequence, the non‐repeatable fraction of phenotypic variation is the sum of measurement error and phenotypic flexibility. There are several ways to estimate repeatability for Gaussian data, but there are no formal agreements on how repeatability should be calculated for non‐Gaussian data (e.g. binary, proportion and count data). In addition to point estimates, appropriate uncertainty estimates (standard errors and confidence intervals) and statistical significance for repeatability estimates are required regardless of the types of data. We review the methods for calculating repeatability and the associated statistics for Gaussian and non‐Gaussian data. For Gaussian data, we present three common approaches for estimating repeatability: correlation‐based, analysis of variance (ANOVA)‐based and linear mixed‐effects model (LMM)‐based methods, while for non‐Gaussian data, we focus on generalised linear mixed‐effects models (GLMM) that allow the estimation of repeatability on the original and on the underlying latent scale. We also address a number of methods for calculating standard errors, confidence intervals and statistical significance; the most accurate and recommended methods are parametric bootstrapping, randomisation tests and Bayesian approaches. We advocate the use of LMM‐ and GLMM‐based approaches mainly because of the ease with which confounding variables can be controlled for. Furthermore, we compare two types of repeatability (ordinary repeatability and extrapolated repeatability) in relation to narrow‐sense heritability. This review serves as a collection of guidelines and recommendations for biologists to calculate repeatability and heritability from both Gaussian and non‐Gaussian data.
•Median peaks of the return stroke current and the ICC fast pulses in this study are 6.4 kA and 3.0 kA, respectively.•Observed parameters do not show much difference from those observed at tall ...structures considering instrumental effect.•The local conditions do not have much inference on the parameters of the fast pulses as well as the return strokes.•The local conditions such as height of the different charge layer have some influence on the IS of the upward flashes.
The authors have carried out measurement of the current waveforms associated with lightning discharges to wind turbines at Nikaho near the coast of the Sea of Japan since 2013. In this paper measured waveforms in winter up to 2020 are investigated and the current waveforms associated with return strokes after the extinction of the ICC (initial continuous current) and fast pulses superimposed on the ICC with the current peak of 2 kA or higher and with the risetimes of 8 µs or shorter are studied. The median current peaks of the 107 return strokes and the 123 fast pulses were 6.4 kA and 3.0 kA, respectively. The observed median current peaks of return strokes and fast pulses at the Nikaho wind turbines (6.4 kA and 3.0 kA) do not show much difference from those observed at the Gaisberg tower (9.2 kA and 4.2 kA), the Säntis tower (8 kA and 3.4 kA) and the Peissenberg tower in Germany (return stroke: 8.5 kA but no report on fast pulses) when the long sampling interval and the low upper cutoff frequency of the measuring system at the Nikaho wind turbines is taken into account.
Background
Interstitial cells of Cajal associated with the submuscular plexus (ICC‐SMP) generate omnipresent slow‐wave activity in the colon and are associated with prominent motor patterns. Our aim ...was to investigate colon motor dysfunction in W/Wv mice in which the ICC are reportedly reduced.
Methods
Whole organ colon motility was studied using spatio‐temporal mapping; immunohistochemical staining was carried out for c‐Kit and Ano1; calcium imaging was applied to ICC‐SMP.
Key Results
Discrepancies between Ano1 and c‐Kit staining were found in both wild‐type and W/Wv colon. ICC‐SMP were reduced to ~50% in the W/Wv mouse colon according to c‐Kit immunohistochemistry, but Ano1 staining indicated a normal network of ICC‐SMP. The latter was consistent with rhythmic calcium transients occurring at the submucosal border of the colon in W/Wv mice, similar to the rhythmic transients in wild‐type ICC‐SMP. Furthermore, the motor pattern associated with ICC‐SMP pacemaking, the so‐called ‘ripples’ were normal in the W/Wv colon.
Conclusions & Inferences
c‐Kit is not a reliable marker for quantifying ICC‐SMP in the mouse colon. Ano1 staining revealed a normal network of ICC‐SMP consistent with the presence of a normal ‘ripples’ motor pattern. We detected a class of Ano1 positive c‐Kit negative cells that do not depend on Kit expression for maintenance, a feature shared with ICC progenitors.
c‐Kit is not a reliable marker for quantifying ICC‐SMP in the mouse colon. Ano1 staining revealed a normal network of ICC‐SMP consistent with the presence of a normal ‘ripples’ motor pattern. We detected a class of Ano1 positive c‐Kit negative cells that do not depend on Kit expression for maintenance, a feature shared with ICC progenitors.
Rhythmic stimulation can be applied to modulate neuronal oscillations. Such ‘entrainment’ is optimized when stimulation frequency is individually calibrated based on magneto/encephalography markers. ...It remains unknown how consistent such individual markers are across days/sessions, within a session, or across cognitive states, hemispheres and estimation methods, especially in a realistic, practical, lab setting. We here estimated individual alpha frequency (IAF) repeatedly from short electroencephalography (EEG) measurements at rest or during an attention task (cognitive state), using single parieto‐occipital electrodes in 24 participants on 4 days (between‐sessions), with multiple measurements over an hour on 1 day (within‐session). First, we introduce an algorithm to automatically reject power spectra without a sufficiently clear peak to ensure unbiased IAF estimations. Then we estimated IAF via the traditional ‘maximum’ method and a ‘Gaussian fit’ method. IAF was reliable within‐ and between‐sessions for both cognitive states and hemispheres, though task‐IAF estimates tended to be more variable. Overall, the ‘Gaussian fit’ method was more reliable than the ‘maximum’ method. Furthermore, we evaluated how far from an approximated ‘true’ task‐related IAF the selected ‘stimulation frequency’ was, when calibrating this frequency based on a short rest‐EEG, a short task‐EEG, or simply selecting 10 Hz for all participants. For the ‘maximum’ method, rest‐EEG calibration was best, followed by task‐EEG, and then 10 Hz. For the ‘Gaussian fit’ method, rest‐EEG and task‐EEG‐based calibration were similarly accurate, and better than 10 Hz. These results lead to concrete recommendations about valid, and automated, estimation of individual oscillation markers in experimental and clinical settings.
We repeatedly measured electroencephalography (EEG) between‐ and within‐sessions, during resting state and attention task, from two posterior electrodes. The ‘maximum’ method on average yielded the same individual alpha frequency (IAF) estimates as a ‘Gaussian fit’ method, but the latter was more consistent, and rest‐IAF was more consistent than task‐IAF. When calibrating rhythmic stimulation protocols to individual EEG markers, we thus recommend rest‐EEG along with a Gaussian fit method.
Virus inactivation validation studies have been widely applied in the risk assessment of biogenic material‐based medical products, such as biological products, animal tissue‐derived biomaterials, and ...allogeneic biomaterials, to decrease the risk of virus transmission. Traditional virus detection methods in an inactivation validation study utilize cell culture as a tool to quantify the infectious virus by observing cytopathic effects (CPEs) after virus inactivation. However, this is susceptible to subjective factors because CPEs must be observed by experts under a microscope during virus titration. In addition, this method is costly and time‐ and labor‐consuming. Molecular biological technologies such as quantitative polymerase chain reaction (qPCR) have been widely used for virus detection but cannot distinguish infectious and noninfectious viruses. Therefore, qPCR cannot be directly applied to virus inactivation validation studies. In this paper, methods to detect viruses and progress in the challenge of differentiating infectious and noninfectious viruses with the combination of pretreatment and qPCR techniques such as the integrated cell culture‐qPCR (ICC‐qPCR) method are reviewed. In addition, the advantages and disadvantages of each new method, as well as its prospect in virus inactivation validation studies, are discussed.
In this review, the basic concept about virus infectivity and mechanisms of virus inactivation, and the methods which currently were investigated for virus detection or virus inactivation validation studies were reviewed and their advantages and disadvantages, as well as the prospect to make it able to be applied in virus inactivation validation study of biogenic material‐based medical products, were discussed.
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