Functional imaging of mucociliary phenomena: High-speed digital reflection contrast microscopy

We present a technique for the investigation of mucociliary phenomena on trachea explants under conditions resembling those in the respiratory tract. Using an enhanced reflection contrast, we detect simultaneously the wave-like modulation of the mucus surface by the underlying ciliary activity and the transport of particles embedded in the mucus layer. Digital recordings taken at a speed of 500 frames per second are analyzed by a set of refined data processing algorithms. The simultaneously extracted data include not only ciliary beat frequency and its surface distribution, but also space-time structure of the mucociliary wave field, wave velocity and mucus transport velocity. Furthermore, we propose the analysis of the space and time evolution of the phase of the mucociliary oscillations to be the most direct way to visualize the coordination of the cilia. In particular, this analysis indicates that the synchronization is restricted to patches with varying directions of wave propagation, but the transport direction is strongly correlated with the mean direction of waves. The capabilities of the technique and of the data-processing algorithms are documented by characteristic data obtained from mammalian and avine trachea

Technical note: how accurate can stalagmite formation temperatures be determined using vapour bubble radius measurements in fluid inclusions?

Stalagmites are natural archives containing detailed information on continental climate variability of the past. Microthermometric measurements of fluid inclusion homogenisation temperatures allow determination of stalagmite formation temperatures by measuring the radius of stable laser-induced vapour bubbles inside the inclusions. A reliable method for precisely measuring the radius of vapour bubbles is presented. The method is applied to stalagmite samples for which the formation temperature is known. An assessment of the bubble radius measurement accuracy and how this error influences the uncertainty in determining the formation temperature is provided. We demonstrate that the nominal homogenisation temperature of a single inclusion can be determined with an accuracy of ±0.25 °C, if the volume of the inclusion is larger than 105 μm3. With this method, we could measure in a proof-of-principle investigation that the formation temperature of 10–20 yr old inclusions in a stalagmite taken from the Milandre cave is 9.87 ± 0.80 °C, while the mean annual surface temperature, that in the case of the Milandre cave correlates well with the cave temperature, was 9.6 ± 0.15 °C, calculated from actual measurements at that time, showing a very good agreement. Formation temperatures of inclusions formed during the last 450 yr are found in a temperature range between 8.4 and 9.6 °C, which corresponds to the calculated average surface temperature. Paleotemperatures can thus be determined within ±1.0 °C

Adhesion between cells, diffusion of growth factors, and elasticity of the AER produce the paddle shape of the chick limb

This paper has been withdrawnComment: This paper has been withdraw

Giant nuclei is essential in the cell cycle transition from meiosis to mitosis

At the transition from meiosis to cleavage mitoses, Drosophila requires the cell cycle regulators encoded by the genes, giant nuclei (gnu), plutonium (plu) and pan gu (png). Embryos lacking Gnu protein undergo DNA replication and centrosome proliferation without chromosome condensation or mitotic segregation. We have identified the gnu gene encoding a novel phosphoprotein dephosphorylated by Protein phosphatase 1 at egg activation. Gnu is normally expressed in the nurse cells and oocyte of the ovary and is degraded during the embryonic cleavage mitoses. Ovarian death and sterility result from gnu gain of function. gnu function requires the activity of pan gu and plu

Rapid scanning wide-field clutter elimination in epi-optoacoustic imaging using comb LOVIT.

Epi-style optoacoustic (OA) imaging provides flexibility by integrating the irradiation optics and ultrasound receiver, yet clutter generated by optical absorption near the probe obscures deep OA sources. Localised vibration tagging (LOVIT) retrieves OA signal from images that are acquired with and without a preceding ultrasonic pushing beam: Radiation force leads to a phase shift of signals coming from the focal area resulting in their visibility in a difference image, whereas clutter from outside the pushing beam is eliminated. Disadvantages of a single-focus approach are residual clutter from inside the pushing beam above the focus, and time-intensive scanning of the focus to retrieve a large field-of-view. To speed up acquisition, we propose to create multiple foci in parallel, forming comb-shaped ARF patterns. By subtracting OA images obtained with interleaved combs, this technique moreover results in greatly improved clutter reduction in phantoms mimicking optical, acoustic and elastic properties of breast tissue

Impaired Glucose Tolerance in Sleep Disorders

BACKGROUND: Recent epidemiological and experimental data suggest a negative influence of shortened or disturbed night sleep on glucose tolerance. Due to the high prevalence of sleep disorders this might be a major health issue. However, no comparative studies of carbohydrate metabolism have been conducted in clinical sleep disorders. METHODOLOGY/PRINCIPAL FINDINGS: We performed oral glucose tolerance tests (OGTT) and assessed additional parameters of carbohydrate metabolism in patients suffering from obstructive sleep apnea syndrome (OSAS, N = 25), restless legs syndrome (RLS, N = 18) or primary insomnia (N = 21), and in healthy controls (N = 33). Compared to controls, increased rates of impaired glucose tolerance were found in OSAS (OR: 4.9) and RLS (OR: 4.7) patients, but not in primary insomnia patients (OR: 1.6). In addition, HbA1c values were significantly increased in the same two patient groups. Significant positive correlations were found between 2-h plasma glucose values measured during the OGTT and the apnea-arousal-index in OSAS (r = 0.56; p<0.05) and the periodic leg movement-arousal-index in RLS (r = 0.56, p<0.05), respectively. Sleep duration and other quantitative aspects of sleep were similar between patient groups. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that some, but not all sleep disorders considerably compromise glucose metabolism. Repeated arousals during sleep might be a pivotal causative factor deserving further experimental investigations to reveal potential novel targets for the prevention of metabolic diseases

Short-term follow up after Large-Area RPE Removal by Microsecond Laser followed by hiPS-RPE suspension transplantation in rabbits

Cell therapy is a promising treatment for retinal pigment epithelium (RPE)-associated eye diseases. Herein, microsecond laser irradiation targeting RPE cells was used for large-area RPE removal followed by subretinal injection of human induced pluripotent stem cell derived RPE (hiPS-RPE). 19 immunosuppressed pigmented rabbits (Chinchilla bastard hybrid) underwent a large area RPE removal using an infrared reflectance (IR) confocal scanning laser ophthalmoscope (cSLO) with spectral-domain optical coherence tomography (SD-OCT) system (Heidelberg Engineering ) extended with a prototype laser (modified Merilas 532 shortpulse ophthalmic laser photocoagulator, Meridian Medical) (wavelength, 532 nm; pulse duration, 8 µs), followed by a 25G vitrectomy. Subsequently, a suspension of hiPS-RPE (1000 cells/ µl) was grafted subretinally into the RPE laser lesion under real-time intraoperative OCT imaging (RESCAN 700, Zeiss) by manual injection via a 25/38G cannula connected to a 100µl Hamilton syringe. 5 rabbits served as a control with hiPS-RPE injected subretinally over healthy RPE. The rabbits were followed with in vivo multimodal retinal imaging at baseline after laser and then for 7 days including fluorescein (FA) and indocyanine angiography (ICGA), aw well as SD-OCT (Spectralis ®, Heidelberg Engineering). Baseline imaging of RPE laser wounds showed mild late phase FA/ICGA leakage, with normal outer retinal and choroidal reflectivity on OCT, without signs of coagulation. The size of the RPE wounds was typically 10-12mm2. Real time iOCT showed a directed spread of the bleb retinal detachment (bRD) within the lasered zone, in contrast to a circular spread in controls. Subretinal injection ranged from 5-20µl, with lesser volumes/ larger bRD areas over lasered regions. At 7 days, implanted regions showed FA/ICGA leakage, blockage due to hyperpigmentation was observed mostly at the edges of the lasered zone; OCT showed hyperreflectivity of the outer retina with RPE irregularities. Control implantation sites showed hyperreflectivity in all retinal layers and a variably thickened RPE band suggesting clumping. Microsecond laser irradiation to the RPE seems to accelerate the subretinal integration of hiPS-RPE, when compared to subretinal injection over intact RPE. Future work will address correlation of multimodal imaging and histology. This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually