Transformed pupil-function misalignment calibration strategy for Fourier ptychographic microscopy.

Fourier ptychographic microscopy (FPM) is an enabling quantitative phase imaging technique with both high-resolution (HR) and wide field-of-view (FOV), which can surpass the diffraction limit of the objective lens by employing an LED array to provide angular-varying illumination. The precise illumination angles are critical to ensure exact reconstruction, while it's difficult to separate actual positional parameters in conventional algorithmic self-calibration approaches due to the mixing of multiple systematic error sources. In this paper, we report a pupil-function-based strategy for independently calibrating the position of LED array. We first deduce the relationship between positional deviation and pupil function in the Fourier domain through a common iterative route. Then, we propose a judgment criterion to determine the misalignment situations, which is based on the arrangement of LED array in the spatial domain. By combining the mapping of complex domains, we can accurately solve the spatial positional parameters concerning the LED array through a boundary-finding scheme. Relevant simulations and experiments demonstrate the proposed method is accessible to precisely correct the positional misalignment of LED array. The approach based on the pupil function is expected to provide valuable insights for precise position correction in the field of microscopy.

Associations Between Delivery Mode and Early Childhood Body Mass Index Z-Score Trajectories: A Retrospective Analysis of 2,685 Children From Mothers Aged 18 to 35 Years at Delivery.

Objective: To investigate the association between cesarean delivery (CD) and trajectory patterns of age- and sex-specific body mass index (BMI) z-score in early childhood. Methods: A retrospective cohort study was conducted among 2,685 children whose maternal age at the time of birth was between 18 and 35 years, and birth data and anthropometric measurement data during their ages 3-60 months were collected. A group-based trajectory modeling approach was used to identify distinct BMI z-score trajectories, and multinomial logistic regressions were applied to estimate the associations among CD (both elective and non-elective combined), elective and non-selective CD, and BMI z-score trajectory classes. Results: Of the 2,685 participants, 46.5% (N = 1,248) were born by vaginal delivery (VD), 20.7% (N = 556) by elective CD, and 32.8% (N = 881) by non-elective CD. Five BMI z-score trajectory patterns were identified, and they were "increasing from moderate to high" (10.1%, n = 270), "increasing from mild to moderate" (34.2%, n = 919), "increasing from low to high" (10.5%, n = 283), "stable mild" (30.1%, n = 808), and "stable low" (15.1%, n = 405) groups. Compared with children delivered by VD, those who delivered by CD (both elective and non-elective combined), elective CD, and non-elective CD were associated with the "increasing from moderate to high" trajectory [odds ratio (OR) = 1.61, 95% confidence interval (CI): 1.13-2.29; OR = 1.64, 95%CI: 1.06-2.54; and OR = 1.59, 95%CI: 1.05-2.39, respectively] and were also associated with the "increasing from low to high" trajectory (OR = 1.60, 95%CI: 1.17-2.19, OR = 1.75, 95%CI: 1.16-2.63; and OR = 1.53, 95%CI: 1.00-2.34, respectively). Conclusion: Both elective and non-elective CD were associated with the risk of accelerated weight gain in early childhood.

Dopamine and Serotonin Receptors Cooperatively Modulate Pacemaker Activity of Intestinal Cells of Cajal.

The neurotransmitters dopamine and serotonin control the peristaltic movement of the gut that consists of propagating waves of rhythmic contraction and relaxation. While intestinal cells of Cajal (ICC) serve as a pacemaker in the gut, the effect of dopamine on the pacemaker activity of ICC remains unknown. Here, we report that together with serotonin receptors, the dopamine receptor D2 contributes to maintaining [Ca²âº]i oscillations in ileum ICC. When the antagonist for the D2 receptor was applied to the cell cluster or the tissue culture prepared from muscle layers of the mouse small intestine, the amplitude of [Ca²âº]i oscillations in ICC declined after a transient increase. On the other hand, treatment with the D2 receptor agonist decreased the frequency of [Ca²âº]i oscillations in ICC. These results suggest that basal level activity of the D2 receptor is crucial for maintaining [Ca²âº]i oscillations in ICC. The decrease in the [Ca²âº]i oscillation amplitude upon the D2 receptor antagonist treatment was abrogated by antagonizing the serotonin receptor 5HT2, indicating an inhibitory effect of the 5HT2 receptor on the [Ca²âº]i oscillations. Together with the finding that treatment with the antagonist for the serotonin receptor 5HT3 completely eliminated [Ca²âº]i oscillations in ICC, our results show that dopamine and serotonin receptors cooperatively regulate pacemaker activity of ICC.

Scanning electron microscope evidence of telocytes in vasculature.

Here, we here present scanning electron microscope data for the existent telocytes (TCs) on the endothelial surface of the wall of pig coronary arteries, internal thoracic arteries and carotid arteries. These cells have a small (8.39 ± 1.97 µm/4.95 ± 0.91 µm) cell body of different shapes (from round to triangular, depending on the number of cellular prolongations) with very long (of about 30 µm) and thin cellular processes called telopodes (Tps), which have uneven calibre. The number of Tps ranges between 2 and 6. Tps typically present the alternation of podoms and podomers, and also have a dichotomic branching pattern. These data could influence the current attempts for elucidating the role(s) of TCs.

Serotonin augments gut pacemaker activity via 5-HT3 receptors.

Serotonin (5-hydroxytryptamine: 5-HT) affects numerous functions in the gut, such as secretion, muscle contraction, and enteric nervous activity, and therefore to clarify details of 5-HT's actions leads to good therapeutic strategies for gut functional disorders. The role of interstitial cells of Cajal (ICC), as pacemaker cells, has been recognised relatively recently. We thus investigated 5-HT actions on ICC pacemaker activity. Muscle preparations with myenteric plexus were isolated from the murine ileum. Spatio-temporal measurements of intracellular Ca(2+) and electric activities in ICC were performed by employing fluorescent Ca(2+) imaging and microelectrode array (MEA) systems, respectively. Dihydropyridine (DHP) Ca(2+) antagonists and tetrodotoxin (TTX) were applied to suppress smooth muscle and nerve activities, respectively. 5-HT significantly enhanced spontaneous Ca(2+) oscillations that are considered to underlie electric pacemaker activity in ICC. LY-278584, a 5-HT(3) receptor antagonist suppressed spontaneous Ca(2+) activity in ICC, while 2-methylserotonin (2-Me-5-HT), a 5-HT(3) receptor agonist, restored it. GR113808, a selective antagonist for 5-HT(4), and O-methyl-5-HT (O-Me-5-HT), a non-selective 5-HT receptor agonist lacking affinity for 5-HT(3) receptors, had little effect on ICC Ca(2+) activity. In MEA measurements of ICC electric activity, 5-HT and 2-Me-5-HT caused excitatory effects. RT-PCR and immunostaining confirmed expression of 5-HT(3) receptors in ICC. The results indicate that 5-HT augments ICC pacemaker activity via 5-HT(3) receptors. ICC appear to be a promising target for treatment of functional motility disorders of the gut, for example, irritable bowel syndrome.

Calcium-associated mechanisms in gut pacemaker activity.

A considerable body of evidence has revealed that interstitial cells of Cajal (ICC), identified with c-Kit-immunoreactivity, act as gut pacemaker cells, with spontaneous Ca(2+) activity in ICC as the probable primary mechanism. Namely, intracellular (cytosolic) Ca(2+) oscillations in ICC periodically activate plasmalemmal Ca(2+)-dependent ion channels and thereby generate pacemaker potentials. This review will, thus, focus on Ca(2+)-associated mechanisms in ICC in the gastrointestinal (GI) tract, including auxiliary organs.

Pacemaker phase shift in the absence of neural activity in guinea-pig stomach: a microelectrode array study.

Gastrointestinal (GI) motility is well organized. GI muscles act as a functional syncytium to achieve physiological functions under the control of neurones and pacemaker cells, which generate basal spontaneous pacemaker electrical activity. To date, it is unclear how spontaneous electrical activities are coupled, especially within a micrometre range. Here, using a microelectrode array, we show a spatio-temporal analysis of GI spontaneous electrical activity. The muscle preparations were isolated from guinea-pig stomach, and fixed in a chamber with an array of 8 x 8 planar multielectrodes (with 300 microm in interpolar distance). The electrical activities (field potentials) were simultaneously recorded through a multichannel amplifier system after high-pass filtering at 0.1 Hz. Dihydropyridine Ca(2+) channel antagonists are known to differentiate the electrical pacemaker activity of interstitial cells of Cajal (ICCs) by suppressing smooth muscle activity. In the presence of nifedipine, we observed spontaneous electrical activities that were well synchronized over the array area, but had a clear phase shift depending on the distance. The additional application of tetrodotoxin (TTX) had little effect on the properties of the electrical activity. Furthermore, by constructing field potential images, we visualized the synchronization of pacemaker electrical activities resolving phase shifts that were measurable over several hundred micrometres. The results imply a phase modulation mechanism other than neural activity, and we postulate that this mechanism enables smooth GI motility. In addition, some preparations clearly showed plasticity of the pacemaker phase shift.

Tyrosine kinase inhibitors and ATP modulate the conversion of smooth muscle L-type Ca2+ channels toward a second open state.

Properties of smooth and cardiac L-type Ca2+ channels differ prominently in several physiological aspects, including sympathetic modulation. To assess the possible underlying mechanisms, we applied the whole cell patch-clamp technique to guinea pig detrusor smooth muscle cells, in which only L-type Ca2+ channel currents are observed in practice. During depolarization to large positive potentials, the conformation of the majority of L-type Ca2+ channels is converted from the normal (O1) to a second open state (O2), which undergoes little inactivation during depolarization. Extracellular application of genistein, a known tyrosine kinase inhibitor, significantly attenuated the voltage-dependent conversion of Ca2+ channels to O2, accompanied by reduction of availability, whereas genistin, an inactive analog, had little effect. In the absence of ATP in the patch pipette, intracellular application of either genistein or tyrphostin-47 suppressed the conversion to O2. Computer calculation revealed that the acceleration of the O1 to an inactivated state qualitatively reconstructs the unique effects of PTK inhibitors antagonized by ATP. We concluded that under normal conditions smooth muscle L-type Ca2+ channels are already modulated by tyrosine-kinase and ATP-related mechanism(s) and thereby easily achieve the second conversion, which yields voltage-dependent modulation of L-type Ca2+ current analogous to that in cardiac myocytes during beta-adrenoceptor stimulation.

Sulphonylurea receptors differently modulate ICC pacemaker Ca2+ activity and smooth muscle contractility.

Appropriate gastrointestinal motility is essential to properly control the body energy level. Intracellular Ca2+ ([Ca2+]i) oscillations in interstitial cells of Cajal (ICCs; identified with c-Kit immunoreactivity) are considered to be the primary mechanism for the pacemaker activity in gastrointestinal motility. In the present study, RT-PCR examinations revealed predominant expression of the type 1 isoform of sulphonylurea receptors (SUR1) in ICCs of the mouse ileum, but expression of SUR2 was predominant in smooth muscle. In cell clusters prepared from the same tissue, smooth muscle contractility and pacemaker [Ca2+]i activity in ICCs were found to be differentially modulated by K(ATP) channel openers and sulphonylurea compounds, in accordance with the expression of SUR isoforms. 1 microM cromakalim nearly fully suppressed the mechanical activity in smooth muscle, whereas ICC pacemaker [Ca2+]i oscillations persisted. Greater concentrations (approximately 10 microM) of cromakalim attenuated pacemaker [Ca2+]i oscillations. This effect was not reversed by changing the reversal potential of K+, but was prevented by glibenclamide. Diazoxide at 30 muM terminated ICC pacemaker [Ca2+]i oscillations, but again treatment with high extracellular K+ did not restore them. These results suggest that SUR can modulate pacemaker [Ca2+]i oscillations via voltage-independent mechanism(s), and also that intestinal pacemaking and glucose control are closely associated with SUR.

Involvement of ryanodine receptors in pacemaker Ca2+ oscillation in murine gastric ICC.

Using a cell cluster preparation from the stomach smooth muscle tissue of mice, we measured intracellular Ca(2+) oscillations in interstitial cells of Cajal (ICCs) in the presence of nifedipine. Pacemaker [Ca(2+)](i) activity in ICCs was significantly suppressed by caffeine application and restored after washout. Application of either ryanodine or FK-506 terminated the pacemaker [Ca(2+)](i) activity irreversibly. Immunostaining of smooth muscle tissue showed that c-Kit-immunopositive cells (that form network-like structure cells in the myenteric plexus, equivalent to ICCs) clearly express ryanodine receptors (RyR). RT-PCR revealed that ICCs (identified with c-Kit-immunoreactivity) predominantly express type 3 RyR (RyR3). Furthermore, the FK-binding proteins 12 and 12.6, both of which would interact with RyR3, were detected. In conclusion, we provide first evidence for the essential contribution of RyR to generating pacemaker activity in gastric motility. Similar mechanisms might account for spontaneous rhythmicity seen in smooth muscle tissues distributed in the autonomic nervous system.

Co-contribution of IP3R and Ca2+ influx pathways to pacemaker Ca2+ activity in stomach ICC.

Intracellular Ca2+ oscillations in interstitial cells of Cajal (ICCs) are thought to be the primary pacemaker activity in the gut. In the present study, the authors prepared small tissues of 100-to 300-microm diameter (cell cluster preparation) from the stomach smooth muscle (including the myenteric plexus) of mice by enzymatic and mechanical treatments. After 2 to 4 days of culture, the intracellular Ca2+ concentration ([Ca2+]i) was measured. In the presence of nifedipine, a dihydropyridine Ca2+ channel antagonist, spontaneous [Ca2+]i oscillations were observed within limited regions showing positive c-Kitimmunoreactivity, a maker for ICCs. In the majority of cell cluster preparations with multiple regions of [Ca2+]i oscillations, [Ca2+]i oscillated synchronously in the same phase. A small number of cell clusters (8 of 53) showed multiple regions of [Ca2+]i oscillations synchronized but with a considerable phase shift. Neither tetrodotoxin (250 nM) nor atropine (10 microM) significantly affected [Ca2+]i oscillations in the presence of nifedipine. Low concentrations (40 microM) of Ni2+ had little effect on the spontaneous [Ca2+]i oscillation, but SK&F96365 (40 microM) and Cd2+ (120 microM) terminated it. Applications of either 2-aminoethoxydiphenyl borate (10 microM) or xestosponginC(10 microM) completely and rather rapidly (approximately 2 min) abolished the spontaneous [Ca2+]i oscillations. The results suggest that pacemaker [Ca2+]i oscillations in ICCs are produced by close interaction of intracellular Ca2+ release channels, especially inositol 1,4,5-trisphosphate receptor (InsP3R) and Ca2+ influx pathways, presumably corresponding to store-operated type channels. Reverse transcription polymerase chain reaction examinations revealed expression of TRPC2, 4, and 6, as well as InsP3R1 and 2 in ICCs.

[Simulation of effects to tropospheric ozone over South East Asia and south China from biomass burning].

The ozone variation led by biomass burning in Spring 2000 over South East Asia and South of China region was simulated with a combined regional climate model and atomospheric chemical model. It was found that ozone was added by the pollutant of biomass burning both over source area and down wind area. The ozone of lower troposphere was affected by the pollutant over source area, so did the ozone in middle troposphere over down wind area. An ozone increase of 9.0-12.0 x 10(-2) g/m2 over South of China was found. The range of ozone increase between 1000-900 hPa over source area was more than 36 x 10(-9) m3/m3.

[Design and development of cerebrospinal fluid container].

The cerebrospinal fluid container is a device for storage of medicaments. By means of surgical operation, a ventricle catheter can be embedded in the ventricle of the brain. This safe and reliable device provides for neurosurgeons a new method of intracranical therapy and reestablishment of the circulating passage of the cerebrospinal fluid.