Pharmacological Dissection of Intrinsic Optical Signal Reveals a Functional Coupling between Synaptic Activity and Astrocytic Volume Transient

The neuronal activity-dependent change in the manner in which light is absorbed or scattered in brain tissue is called the intrinsic optical signal (IOS), and provides label-free, minimally invasive, and high spatial (~100 µm) resolution imaging for visualizing neuronal activity patterns. IOS imaging in isolated brain slices measured at an infrared wavelength (>700 nm) has recently been attributed to the changes in light scattering and transmittance due to aquaporin-4 (AQP4)-dependent astrocytic swelling. The complexity of functional interactions between neurons and astrocytes, however, has prevented the elucidation of the series of molecular mechanisms leading to the generation of IOS. Here, we pharmacologically dissected the IOS in the acutely prepared brain slices of the stratum radiatum of the hippocampus, induced by 1 s/20 Hz electrical stimulation of Schaffer-collateral pathway with simultaneous measurement of the activity of the neuronal population by field potential recordings. We found that 55% of IOSs peak upon stimulation and originate from postsynaptic AMPA and NMDA receptors. The remaining originated from presynaptic action potentials and vesicle fusion. Mechanistically, the elevated extracellular glutamate and K⁺ during synaptic transmission were taken up by astrocytes via a glutamate transporter and quinine-sensitive K2P channel, followed by an influx of water via AQP-4. We also found that the decay of IOS is mediated by the DCPIB- and NPPB-sensitive anion channels in astrocytes. Altogether, our results demonstrate that the functional coupling between synaptic activity and astrocytic transient volume change during excitatory synaptic transmission is the major source of IOS.

Patient posture for blood collection by venipuncture: recall for standardization after 28 years

ABSTRACT Background: Although data about the effect of posture on routine hematological testing were published 28 years ago, this pre-analytical issue has not been standardized so far. This study was planned to evaluate whether postural changes influence the results of hematology testing. Methods: A complete blood count was performed in 19 healthy volunteers after 25 min in the supine position, 20 min in a sitting position and 20 min stationary standing in an upright position. Results: The change from supine to sitting position caused clinically significant increases in the hemoglobin, hematocrit and red blood cell count. Furthermore, the change from supine to standing caused clinically significant increases in the hemoglobin, hematocrit, red blood cell, leukocyte, neutrophil, lymphocyte, basophil and platelet counts, and mean platelet volume, and that from sitting to standing caused clinically significant increases in hemoglobin, hematocrit, and red blood cell, leukocyte, neutrophil and lymphocyte counts. Conclusion: The results of this investigation provide further support to the notion that effort should be made to achieve widespread standardization in the practice of phlebotomy, including patient posture.

A study of changes in volume and location of target areas and organs at risk in intensity-modulated radiotherapy for cervical cancer / 中华放射肿瘤学杂志

Objective To investigate the changes in volume and spatial location of target areas and normal tissues before and during intensity?modulated radiotherapy (IMRT) for cervical cancer by quantitative means. Methods Forty patients with cervical cancer who were treated with IMRT were enrolled as subjects. Computed tomography ( CT) was performed before IMRT and during IMRT when a dose of 27 Gy ( 15 fractions) was reached. Clinicians delineated the target areas and organs at risk in the two groups of CT images. The target areas and organs at risk in one group of images were mapped to the other group of CT image by image registration using the Pinnacle treatment planning system. Volume changes in target areas and organs at risk were analyzed, and changes in the spatial location were evaluated by volume difference method and Dice similarity method. Comparison was made by paired t?test. Results There were significant differences in gross target volumes of primary tumor lesions ( GTV?T) and pelvic metastatic lymph nodes (GTV?N) before and during IMRT ( P= 0?? 000; P= 0?? 000). According to the evaluation by volume difference method, the average rate of change in GTV?T was (38.64±19?? 50)% with a range between 3?? 16%and 86?? 49%, while the average rate of change in GTV?N was (42.49± 25?? 68)% with a range between 2?? 79% and 87?? 42%. In the organs at risk, the bladder had the maximum rate of volume change, the average of which was (55.13±33?? 40)% with a range between 3?? 25% and 116?? 01%. According to the evaluation by Dice similarity method, the average Dice similarity coefficient for GTV?T was 0.50± 0?? 18 with a range between 0?? 10 and 0?? 85, while the average Dice similarity coefficient for GTV?N was 0.31±0?? 20 with a range between 0?? 00 and 0?? 71. The rectum had the minimum Dice coefficient in the organs at risk, the average of which was 0.57± 0?? 14 with a range between 0?? 18 and 0?? 76 . Conclusions For patients with cervical cancer to receive IMRT, since there are substantial changes in volume and spatial location of target areas and normal tissues before and during treatment, it is quite necessary to modify the treatment regimen in time in order to provide adequate doses for target areas and avoid overdose for organs at risk.

Quantitative Assessment of Global and Regional Air Trappings Using Non-Rigid Registration and Regional Specific Volume Change of Inspiratory/Expiratory CT Scans: Studies on Healthy Volunteers and Asthmatics

OBJECTIVE: The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. MATERIALS AND METHODS: Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. RESULTS: Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). CONCLUSION: Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.

Developmental Role of Anoctamin-1/TMEM16A in Ca2+-Dependent Volume Change in Supporting Cells of the Mouse Cochlea

Mammalian cochlea undergoes morphological and functional changes during the postnatal period, around the hearing onset. Major changes during the initial 2 postnatal weeks of mouse include maturation of sensory hair cells and supporting cells, and acquisition of afferent and efferent innervations. During this period, supporting cells in the greater epithelial ridge (GER) of the cochlea exhibit spontaneous and periodic activities which involves ATP, increase in intracellular Ca2+, and cell volume change. This Ca2+-dependent volume change has been proposed to involve chloride channels or transporters. We found that the spontaneous volume changes were eliminated by anion channel blocker, 100 microM NPPB. Among candidates, expression of Anoctamin-1 (Ano1 or TMEM16A), bestriphin-1 and NKCC1 were investigated in whole-mount cochlea of P9-10 mice. Immunolabeling indicated high level of Ano1 expression in the GER, but not of betrophin-1 or NKCC1. Double-labeling with calretinin and confocal image analysis further elucidated the cellular localization of Ano1 immunoreactivity in supporting cells. It was tested if the Ano1 expression exhibits similar time course to the spontaneous activities in postnatal cochlear supporting cells. Cochlear preparations from P2-3, P5-6, P9-10, P15-16 mice were subjected to immunolabeling. High level of Ano1 immunoreactivity was observed in the GER of P2-3, P5-6, P9-10 cochleae, but not of P15-17 cochleae. Taken together, the localization and time course in Ano1 expression pattern correlates with the spontaneous, periodic volume changes recorded in postnatal cochlear supporting cells. From these results we propose that Ano1 is the pacemaker of spontaneous activities in postnatal cochlea.

Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae) during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis

This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy) and interannual (low and high volume conditions). The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapala, Mexico, revealed the significant influence of contrasting conditions (P=0.0002). Seasonally, segregation was more related to species dominance in the dry season and exclusively related to environmental characteristics in the rainy season. Interanually, biotic influence occurred in the shallowest and the deepest episodes of the lake. Environmental characteristics influenced species distribution when the lake reached 25 percent of its volume. Site, depth, temperature, and salinity were the leading factors influencing fish distribution. These results emphasize the necessity to implement different management strategies according to lake volume, particularly when a critical threshold is reached.

El presente estudio describe la influencia que tiene la fluctuación del nivel del agua en la distribución de los peces a dos diferentes escalas: estacional (estiaje y lluvias) e interanual (condiciones de bajo y alto volumen). El análisis de las relaciones de abundancia entre tres especies zooplanctófagas de Chirostoma en quince sitios del Lago de Chapala, México, reveló una influencia estadísticamente significativa en las condiciones contrastantes (P=0.0002). Estacionalmente, la segregación estuvo más relacionada a la dominancia de las especies en la época de estiaje y exclusivamente relacionada a las características ambientales en la época de lluvias. Interanualmente, la influencia biótica se presenta en los episodios más someros y más profundos del lago. Las características ambientales influenciaron la distribución de las especies cuando el lago alcanzó el 25 por ciento de su volumen. El sitio geográfico, profundidad, temperatura y salinidad fueron los principales factores que influenciaron la distribución de los peces. Estos resultados enfatizan la necesidad de implementar diferentes estrategias de manejo de acuerdo al volumen del lago, particularmente cuando se alcanza un umbral crítico.

Quantitative Analysis of the Orbital Volume Change in Isolated Zygoma Fracture

PURPOSE: The zygoma(Zygomaticomaxillary) complexes make up a large portion of the orbital floor and lateral orbital walls. Zygoma fracture frequently causes the posteromedial displacement of bone fragments, and the collapse or overlapping of internal orbital walls. This process consequently can lead to the orbital volume change. The reduction of zygoma in an anterolateral direction may influence on the potential bone defect area of the internal orbital walls. Thus we performed the quantitative analysis of orbital volume change in zygoma fracture before and after operation. METHODS: We conducted a retrospective study of preoperative and postoperative three-dimensional computed tomography scans in 39 patients with zygoma fractures who had not carried out orbital wall reconstruction. Orbital volume measurement was obtained through Aquarius Ver. 4.3.6 program and we compared the orbital volume change of injured orbit with that of the normal contralateral orbit. RESULTS: The average orbital volume of normal orbit was 19.68cm3. Before the operation, the average orbital volume of injured orbit was 18.42cm3. The difference of the orbital volume between the injured orbit and the normal orbit was 1.18cm3(6.01%) on average. After operation, the average orbital volume of injured orbit was 20.81cm3. The difference of the orbital volume between the injured orbit and the normal orbit was 1.17cm3(5.92%) on average. CONCLUSION: There are considerable volume changes in zygoma fracture which did not accompany internal orbital wall fracture before and after operation. Our study reflects the change of bony frame, also that of all parts of the orbital wall, in addition to the bony defect area of orbital floor, in an isolated zygoma fracture so that it evaluates orbital volume change more accurately. Thus, the measurement of orbital volume in isolated zygoma fractures helps predict the degree of enophthalmos and decide a surgical plan.

The three dimensional analysis of volumetric airway change in orthognathic surgery of mandibular prognathism

A novel 3D scan method to quantify teeth wear / 대한치과보철학회지

STATEMENT OF PROBLEM: Tooth wear is physiological phenomenon. Ninety-seven percent of normal people have tooth wear and about 7% has pathologic teeth wear. If we know the amount of tooth surface loss caused by pathologic tooth wear, we may restore it ideally. PURPOSE: Recently, measurement of tooth wear by using 3D scan has been increasing. Therefore, we need to know how accurate 3D scan is. Past accuracy test on 3D scan was about linear change, but as we know that tooth wear is volume change. Thus, the purpose of this study is to know how accurate 3D scan is. MATERIAL AND METHODS: For accuracy test of 3D scanner, volume values measured by 3D scanner and micro-balance were compared. For test I, preliminary, 3 ball samples and 3 circular cones were made with pattern resin. For test II, 10 teeth shape rubber samples were used. RESULTS AND CONCLUSION: 1. The result of the accuracy test on 3D scan with 3 ball samples and 3 circular cones made of pattern resin has no significant difference(p<0.05). 2. The result of the accuracy test on 3D scan with 10 samples of tooth shape rubber has no significant difference(p<0.05). As a result, we may concluded the analysis of quantifying tooth wear used by 3D scan is useful in the clinic.

Blood Volume Change and Side Effects during Various Sodium Ramping in Hemodialysis / 대한신장학회잡지

Chronic hemodialysis patients frequently experience hemodialysis(HD)-related side effects caused by excessive ultrafiltration and abrupt change of osmolality. Sodium ramping in HD is known to reduce ultrafiltration-related side effects, but it frequently induces symptoms related to sodium overload. We wanted to know the relationship between blood volume changes and the side effects related to ultrafiltration during hemodialysis and whether we can individualize various sodium ramping methods according to the effect of change in blood volume( BV) and side effects of sodium ramping. We studied 9 hypotension-prone patients during HD. The duration of the study lasted for 5 weeks, each week using different sodium ramping protocols: protocol 1; dialysate [Na+] of 140mEq/L, protocol 2; dialysate [Na+] same as the predialysis serum [Na+], protocol 3; dialysate [Na+] was 20mEq/L greater than that of the patient's serum for 1hr, 10mEq/L greater than patient's serum [Na+] for 2hr and then the same as patient's serum [Na+] for the last 1hr, protocol 4; at the beginning of dialysis, dialysate sodium was ramped to 20mEq/L above the patient's serum sodium and then on a straight linear fashion lowered to the predialysis serum [Na+] at the end of dialysis, protocol 5; sodium was constantly ramped to 10 mEq/L above serum [Na+]. We measured the BV with Crit-Line IIR(In-Line Diagnostics, Corp., Riverdale, USA), the blood pressure during each HD and interdialytic weight gain. We documented subjective symptoms which occurred during the 5 treatment protocols by patient's questionnaire after each HD. The results were as follows. 1) The mean age of the patients(M:F=3:6) was 54.1years and 6 patients were diabetics. 2) There was no significant difference in the BV among the 5 protocols in both whole study population and individual. Neither was there a statistically significant difference in the BV with respect to hypotension during HD. 3) There were no episodes of hypotension(P value <0.001) with protocols 3, 4, 5 compared to protocols 1 and 2. 4) Three patients during protocols 4 and 5 experienced more thirst after HD than during protocol 1 and one patient during protocol 4, 5 had more interdialytic weight gain than the protocol 1. As a whole, patients while on protocol 4 & 5 experienced more thirst than protocol 1 but patients during protocol 3 experienced the same degree of thirst as protocol 1. In summary, sodium ramping reduced HD-related side effects but this benefit could not be explained on the basis of blood volume change measured by the Crit-Line IIR. Protocol 3 may be more appropiate sodium ramping method in 4 of the 9 patients. These data suggest that protocol 3 may be used before protocol 4, 5 when we apply sodium ramping to the patients who frequently have hypotension during HD.