The gastric H,K-ATPase in stria vascularis contributes to pH regulation of cochlear endolymph but not to K secretion

Citation: Miyazaki, H., Wangemann, P., & Marcus, D. C. (2016). The gastric H,K-ATPase in stria vascularis contributes to pH regulation of cochlear endolymph but not to K secretion. BMC Physiology, 17(1), 1. https://doi.org/10.1186/s12899-016-0024-1Background Disturbance of acid–base balance in the inner ear is known to be associated with hearing loss in a number of conditions including genetic mutations and pharmacologic interventions. Several previous physiologic and immunohistochemical observations lead to proposals of the involvement of acid–base transporters in stria vascularis. Results We directly measured acid flux in vitro from the apical side of isolated stria vascularis from adult C57Bl/6 mice with a novel constant-perfusion pH-selective self-referencing probe. Acid efflux that depended on metabolism and ion transport was observed from the apical side of stria vascularis. The acid flux was decreased to about 40 % of control by removal of the metabolic substrate (glucose-free) and by inhibition of the sodium pump (ouabain). The flux was also decreased a) by inhibition of Na,H-exchangers by amiloride, dimethylamiloride (DMA), S3226 and Hoe694, b) by inhibition of Na,2Cl,K-cotransporter (NKCC1) by bumetanide, and c) by the likely inhibition of HCO3/anion exchange by DIDS. By contrast, the acid flux was increased by inhibition of gastric H,K-ATPase (SCH28080) but was not affected by an inhibitor of vH-ATPase (bafilomycin). K flux from stria vascularis was reduced less than 5 % by SCH28080. Conclusions These observations suggest that stria vascularis may be an important site of control of cochlear acid–base balance and demonstrate a functional role of several acid–base transporters in stria vascularis, including basolateral H,K-ATPase and apical Na,H-exchange. Previous suggestions that H secretion is mediated by an apical vH-ATPase and that basolateral H,K-ATPase contributes importantly to K secretion in stria vascularis are not supported. These results advance our understanding of inner ear acid–base balance and provide a stronger basis to interpret the etiology of genetic and pharmacologic cochlear dysfunctions that are influenced by endolymphatic pH

Development of Assembly Robot System for Flexible Belt-Shaped Subject

We develop an assembly robot system for assembling the flexible belt-shaped subject. An image processing method is developed to recognize the belt-shaped subject. This method is able to determine the grasping point and grasping angle for piking up a subject by a multiple hands unit. CAD information is used to determine the grasping point. The multiple hands unit is developed, which is able to grasp all grasping points of a subject at a time. In addition, the image processing method is used to judge whether a subject is fastened accurately at right position or not during the assembly

Stepwise development of Hematopoietic stem Cells from Embryonic Stem Cells

The cellular ontogeny of hematopoietic stem cells (HSCs) remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC) differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs) as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit(+)CD41(+)CD45(−) phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs. We propose an HSC developmental model in which pre-HSCs and embryonic HSCs sequentially give rise to adult types of HSCs in a stepwise manner

Analysis of Meteorological Measurements made over Three Rainy Seasons and Rainfall Simulations in Sinazongwe District, Southern Province, Zambia

Zambia has frequently been affected by abnormal weather and droughts. Our research focused on the type of meteorological data required to assist farmers\u27 efforts to avoid the risks associated with these weather conditions. We conducted local meteorological observations from September 2007 to August 2010 at three sites in Sinazongwe District, Zambia. The three rainy seasons of this period coincided in sequence with La Niña (normal) and El Niño conditions. The mean annual precipitation for the three years of our study exceeded 1200 mm, which was considerably more than the regional annual average rainfall from 1970 to 2000 of a round 800 mm per year. We used detailed analyses of intraseasonal variations in other meteorological elements to attempt to explain the high precipitation.Local circulation dominated in our research area, while heavy rain induced by convection in the afternoon and night might account for precipitation exceeding the norm. We numerically simulated meteorological conditions over the past decade to determine whether the annual precipitation observed since September 2007 indeed exceeded the norm. lntra-seasonal variations in precipitation, such as high rainfall in December during the 2007/2008 rainy season, a gradual increase in cumulative precipitation through 2008/2009, and high rainfall in February in the 2009/2010 rainy season were possibly controlled by El Niño - Southern Oscil lation. Our results suggest that annual variations in precipitation are common in this area and that the precipitation we observed did not necessarilyexceed the norm

Factors Affecting the Variation of Maximum Speech Intelligibility in Patients With Sensorineural Hearing Loss Other Than Apparent Retrocochlear Lesions

ObjectivesTo examine the relationship between speech intelligibilities among the similar level of hearing loss and threshold elevation of the auditory brainstem response (ABR).MethodsThe relationship between maximum speech intelligibilities among similar levels of hearing loss and relative threshold elevation of the click-evoked ABR (ABR threshold - pure tone average at 2,000 and 4,000 Hz) was retrospectively reviewed in patients with sensorineural hearing loss (SNHL) other than apparent retrocochlear lesions as auditory neuropathy, vestibular schwannoma and the other brain lesions.ResultsComparison of the speech intelligibilities in subjects with similar levels of hearing loss found that the variation in maximum speech intelligibility was significantly correlated with the threshold elevation of the ABR.ConclusionThe present results appear to support the idea that variation in maximum speech intelligibility in patients with similar levels of SNHL may be related to the different degree of dysfunctions of the inner hair cells and/or cochlear nerves in addition to those of outer hair cells

Indigenous Climate Information and Modern Meteorological Records in Sinazongwe District, Southern Province, Zambia

In 2007, we conducted field research in Sinazongwe District in Southern Province, Zambia, focusing on collecting indigenous information concerning the local climate, which was often embodied in proverbs involving weather forecasts. The indigenous information was compared with recently collected meteorological records and a relationship between popular folk knowledge, local climate, and global climate factors such as ENSO (El Nino and the Southern Oscillation) was suggested. Proverbs related to agriculture and climate were categorized into four types of indicators used to forecast rain: the emergence of butterflies; tree characteristics (producing shoots, flowering, and dropping water); wind direction, wind speed, and temperature; and wind sound. The first two types are based on sea sonal changes in life forms, and the latter two use wind variations produced by synoptic pattern changes

PoGOLite - A High Sensitivity Balloon-Borne Soft Gamma-ray Polarimeter

We describe a new balloon-borne instrument (PoGOLite) capable of detecting 10% polarisation from 200mCrab point-like sources between 25 and 80keV in one 6 hour flight. Polarisation measurements in the soft gamma-ray band are expected to provide a powerful probe into high-energy emission mechanisms as well as the distribution of magnetic fields, radiation fields and interstellar matter. At present, only exploratory polarisation measurements have been carried out in the soft gamma-ray band. Reduction of the large background produced by cosmic-ray particles has been the biggest challenge. PoGOLite uses Compton scattering and photo-absorption in an array of 217 well-type phoswich detector cells made of plastic and BGO scintillators surrounded by a BGO anticoincidence shield and a thick polyethylene neutron shield. The narrow FOV (1.25msr) obtained with well-type phoswich detector technology and the use of thick background shields enhance the detected S/N ratio. Event selections based on recorded phototube waveforms and Compton kinematics reduce the background to that expected for a 40-100mCrab source between 25 and 50keV. A 6 hour observation on the Crab will differentiate between the Polar Cap/Slot Gap, Outer Gap, and Caustic models with greater than 5 sigma; and also cleanly identify the Compton reflection component in the Cygnus X-1 hard state. The first flight is planned for 2010 and long-duration flights from Sweden to Northern Canada are foreseen thereafter.Comment: 11 pages, 11 figures, 2 table

Normative references of heart rate variability and salivary alpha-amylase in a healthy young male population

<p>Abstract</p> <p>Background</p> <p>This study aimed to present normative reference values of heart rate variability and salivary alpha-amylase in a healthy young male population with a particular focus on their distribution and reproducibility.</p> <p>Methods</p> <p>The short-term heart rate variability of 417 young healthy Japanese men was studied. Furthermore, salivary alpha-amylase was measured in 430 men. The average age of the subjects were 21.9 years with standard deviation of 1.6 years. Interindividual variations in heart rate variability indices and salivary alpha-amylase levels were plotted as histograms. Data are presented as the mean, median, standard deviation, coefficient of variation, skewness, kurtosis, and fifth and 95th percentiles of each physiological index.</p> <p>Results</p> <p>Mean recorded values were heart period 945.85 ms, log-transformed high frequency component 9.84 ln-ms², log-transformed low frequency component 10.42 ln-ms², log-transformed low frequency to high frequency ratio 0.58 ln-ratio, standard deviation of beat-to-beat interval 27.17 ms and root mean square of successive difference 37.49 ms. The mean value of raw salivary alpha-amylase was 17.48 U/mL, square root salivary alpha-amylase 3.96 sqrt[U/mL] and log-transformed salivary alpha-amylase 2.65 ln[U/mL]. Log-transformed heart rate variability indices exhibited almost symmetrical distributions; however, time-domain indices of heart rate variability (standard deviation of beat-to-beat interval and root mean square of successive difference) exhibited right-skewed (positive skewness) distributions. A considerable right-skewed distribution was observed for raw salivary alpha-amylase. Logarithmic transformation improved the distribution of salivary alpha-amylase, although square root transformation was insufficient. The day-to-day reproducibility of these indices was assessed using intraclass correlation coefficients. Intraclass correlation coefficients of most heart rate variability and salivary indices were approximately 0.5 to 0.6. Intraclass correlation coefficients of raw salivary markers were approximately 0.6, which was similar to those of heart rate variability; however, log transformation of the salivary markers did not considerably improve their reproducibility. Correlations between sympathetic indicators of heart rate variability and salivary alpha-amylase were not observed.</p> <p>Conclusion</p> <p>Because the sample population examined in this study involved limited age and gender variations, the present results were independent of these factors and were indicative of pure interindividual variation.</p