Increase In Tissue Water Content Research Articles

Effect of Na, K and Ca Salts on Growth, Physiological Performance, Ion Accumulation and Mineral Nutrition of Mesembryanthemum crystallinum.

Mesembryanthemum crystallinum L. is an obligatory halophyte species showing optimum growth at elevated soil salinity levels, but the ionic requirements for growth stimulation are not known. The aim of the present study was to compare the effects of sodium, potassium and calcium in the form of chloride and nitrate salts on the growth, physiological performance, ion accumulation and mineral nutrition of M. crystallinum plants in controlled conditions. In a paradoxical way, while sodium and potassium had comparable stimulative effect on plant growth, the effect of calcium was strongly negative even at a relatively low concentration, eventually leading to plant death. Moreover, the effect of Ca nitrate was less negative in comparison to that of Ca chloride, but K in the form of nitrate had some negative effects. There were three components of the stimulation of biomass accumulation by NaCl and KCl salinity in M. crsytallinum: the increase in tissue water content, increase in ion accumulation, and growth activation. As optimum growth was in a salinity range from 20 to 100 mM, the increase in the dry biomass of plants at a moderate (200 mM) and high (400 mM) salinity in comparison to control plants was mostly due to ion accumulation. Among physiological indicators, changes in leaf chlorophyll concentration appeared relatively late, but the chlorophyll a fluorescence parameter, Performance Index Total, was the most sensitive to the effect of salts. In conclusion, both sodium and potassium in the form of chloride salts are efficient in promoting the optimum growth of M. crystallinum plants. However, mechanisms leading to the negative effect of calcium on plants need to be assessed further.

In-vivo detection of white adipose tissue browning: a multimodality imaging approach

Detection and differentiation of brown fat in humans poses several challenges, as this tissue is sparse and often mixed with white adipose tissue. Non-invasive detection of beige fat represents an even greater challenge as this tissue is structurally and functionally more like white fat than brown fat. Here we used positron emission tomography with 18F-fluorodeoxyglucose, computed tomography, xenon-enhanced computed tomography, and dynamic contrast-enhanced ultrasound, to non-invasively detect functional and structural changes associated with the browning process of inguinal white fat, induced in mice by chronic stimulation with the β3-adrenergic receptor agonist CL-316243. These studies reveal a very heterogeneous increase in baseline tissue radiodensity and xenon-enhanced radiodensity, indicative of both an increase in adipocytes water and protein content as well as tissue perfusion, mostly in regions that showed enhanced norepinephrine-stimulated perfusion before CL-316243 treatment. No statistically significant increase in 18F-fluorodeoxyglucose uptake or norepinephrine-stimulated tissue perfusion were observed in the mice after the CL-316243 treatment. The increase in tissue-water content and perfusion, along with the negligible increase in the tissue glucose uptake and norepinephrine-stimulated perfusion deserve more attention, especially considering the potential metabolic role that this tissue may play in whole body metabolism.

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Type of Anion Largely Determines Salinity Tolerance in Four Rumex Species.

The aim of the present study was to compare the effect of various salts composed of different cations (Na+, K+) and anions (chloride, nitrate, nitrite) on growth, development and ion accumulation in three Rumex species with accessions from sea coast habitats (Rumex hydrolapathum, Rumex longifolius and Rumex maritimus) and Rumex confertus from an inland habitat. Plants were cultivated in soil in an experimental automated greenhouse during the autumn-winter season. Nitrite salts strongly inhibited growth of all Rumex species, but R. maritimus was the least sensitive. Negative effects of chloride salts were rather little-pronounced, but nitrates resulted in significant growth stimulation, plant growth and development. Effects of Na+ and K+ at the morphological level were relatively similar, but treatment with K+ salts resulted in both higher tissue electrolyte levels and proportion of senescent leaves, especially for chloride salts. Increases in tissue water content in leaves were associated with anion type, and were most pronounced in nitrate-treated plants, resulting in dilution of electrolyte concentration. At the morphological level, salinity responses of R. confertus and R. hydrolapathum were similar, but at the developmental and physiological level, R. hydrolapathum and R. maritimus showed more similar salinity effects. In conclusion, the salinity tolerance of all coastal Rumex species was high, but the inland species R. confertus was the least tolerant to salinity. Similarity in effects between Na+ and K+ could be related to the fact that surplus Na+ and K+ has similar fate (including mechanisms of uptake, translocation and compartmentation) in relatively salt-tolerant species. However, differences between various anions are most likely related to differences in physiological functions and metabolic fate of particular ions.

260. EFFECT OF ENDOLUMINAL VACUUM THERAPY ON THE PERFUSION OF GASTRIC CONDUIT IN A PORCINE MODEL FOR ESOPHAGECTOMY

Abstract After esophagectomy, the postoperative rate of anastomotic leakage is between 5 and 30% and is the main driver of morbidity and mortality. Complication management is often based on endoluminal vacuum therapy (EndoVAC) with good success rates. Vacuum therapy has been shown to improve tissue perfusion in superficial wounds but this has not been shown for gastric conduits. The present study aimed to assess changes in gastric conduit perfusion in a porcine model for esophagectomy. Porcine model (n = 18) underwent gastric conduit formation and induction of partial conduit ischemia. In three experimental groups EndoVAC therapy was used in the gastric conduit (−40 mmHg, −125 mmHg and − 200 mmHg) with continuous suction. The changes in tissue perfusion and edema were assessed using hyperspectral imaging (HSI). During EndoVAC treatment with −125 mmHg a significant and stable increase in the oxygenation index from 44.9 ± 7.6% to 61.9 ± 5.5% and 62.9 ± 9.4%. (p = 0.02) was seen after 60 minutes and 120 minutes respectively. A similar trend was seen during EndoVAC treatment with −200 mmHg. There was a non-significant increase in tissue oxygenation during treatment with −40 mmHg. A significant increase of tissue water content from 40.8 ± 7.4 to 59.5 ± 10.3 (p = 0.004) was observed after 60 minutes of EndoVAC therapy with −200 mmHg. There were no significant differences in tissue water content during EndoVAC therapy with −40 mmHg and − 125 mmHg. EndoVAC treatment with a pressure of at least −125 mmHg significantly increases perfusion of partial ischemic gastric conduit. With better understanding of underlying physiology, the optimal use of EndoVac treatment can be guided and determined including a possible preemptive use for gastric conduits with impaired arterial perfusion or venous congestion. This can potentially be translated into clinical practice.

Development and Physiological Performance of Hydroponically-Grown Ornamental Indoor Plants in Relation to their Potential Use in Botanical Biofilters: Effect of Mineral Nutrient Availability

Abstract The aim of the present study was to evaluate the effect of different levels of mineral nutrient availability on development and physiological performance of several common indoor ornamental plant species (Anthurium sp., Chlorophytum comosum, Epipremnum aureum, Plectranthus fruticosus, Spathiphyllum sp., and Tradescantia pallida) cultivated in hydroponics with potential use in active botanical biofilter systems. Plants were grown in expanded clay granules at four levels of mineral nutrient availability provided by two types of commercial mineral fertiliser. The growth stimulative effect of increased mineral nutrient availability depended on plant growth rate, with a lower effect on slower growing species. The need for nutrients increased in the order Anthurium < Spathiphyllum < Epipremnum < Chlorophytum < Tradescantia < Plectranthus. Tissue water content showed pronounced differences between various plant species as well as between plant organs. For several species, increase in mineral nutrient availability resulted in a significant increase in tissue water content. Chlorophyll fluorescence analysis showed that indoor plants can successfully adapt to low and moderate mineral fertiliser levels with balanced individual nutrient rates, without negative consequences to photochemistry of photosynthesis. Consequently, indoor plants can be cultivated at a relatively low concentration of mineral nutrients for optimum utilisation in active botanical biofilter systems.

Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery \u2014 an observational clinical pilot study

BackgroundHyperspectral imaging (HSI) could provide extended haemodynamic monitoring of perioperative tissue oxygenation and tissue water content to visualize effects of haemodynamic therapy and surgical trauma. The objective of this study was to assess the capacity of HSI to monitor skin microcirculation and possible relations to perioperative organ dysfunction in patients undergoing pancreatic surgery.MethodsThe hyperspectral imaging TIVITA® Tissue System was used to evaluate superficial tissue oxygenation (StO2), deeper layer tissue oxygenation (near-infrared perfusion index (NPI)), haemoglobin distribution (tissue haemoglobin index (THI)) and tissue water content (tissue water index (TWI)) in 25 patients undergoing pancreatic surgery. HSI parameters were measured before induction of anaesthesia (t1), after induction of anaesthesia (t2), postoperatively before anaesthesia emergence (t3), 6 h after emergence of anaesthesia (t4) and three times daily (08:00, 14:00, 20:00 ± 1 h) at the palm and the fingertips until the second postoperative day (t5–t10). Primary outcome was the correlation of HSI with perioperative organ dysfunction assessed with the perioperative change of SOFA score.ResultsTwo hundred and fifty HSI measurements were performed in 25 patients. Anaesthetic induction led to a significant increase of tissue oxygenation parameters StO2 and NPI (t1–t2). StO2 and NPI decreased significantly from t2 until the end of surgery (t3). THI of the palm showed a strong correlation with haemoglobin levels preoperatively (t2:r = 0.83, p < 0.001) and 6 h postoperatively (t4: r = 0.71, p = 0.001) but not before anaesthesia emergence (t3: r = 0.35, p = 0.10). TWI of the palm and the fingertip rose significantly between pre- and postoperative measurements (t2–t3). Higher blood loss, syndecan level and duration of surgery were associated with a higher increase of TWI. The perioperative change of HSI parameters (∆t1–t3) did not correlate with the perioperative change of the SOFA score.ConclusionThis is the first study using HSI skin measurements to visualize tissue oxygenation and tissue water content in patients undergoing pancreatic surgery. HSI was able to measure short-term changes of tissue oxygenation during anaesthetic induction and pre- to postoperatively. TWI indicated a perioperative increase of tissue water content. Perioperative use of HSI could be a useful extension of haemodynamic monitoring to assess the microcirculatory response during haemodynamic therapy and major surgery.Trial registrationGerman Clinical Trial Register, DRKS00017313 on 5 June 2019

Investigating the microstructural properties of normal-appearing white matter (NAWM) preceding conversion to white matter hyperintensities (WMHs) in stroke survivors

Using advanced diffusion MRI, we aimed to assess the microstructural properties of normal-appearing white matter (NAWM) preceding conversion to white matter hyperintensities (WMHs) using 3-tissue diffusion signal compositions in ischemic stroke. Data were obtained from the Cognition and Neocortical Volume After Stroke (CANVAS) study. Diffusion-weighted MR and high-resolution structural brain images were acquired 3- (baseline) and 12-months (follow-up) post-stroke. WMHs were automatically segmented and longitudinal assessment at 12-months was used to retrospectively delineate NAWM voxels at baseline converting to WMHs. NAWM voxels converting to WMHs were further dichotomized into either: “growing” WMHs if NAWM adhered to existing WMH voxels, or “isolated de-novo" WMHs if NAWM was unconnected to WMH voxels identified at baseline. Microstructural properties were assessed using 3-tissue diffusion signal compositions consisting of white matter-like (WM-like: TW), gray matter-like (GM-like: TG), and cerebrospinal fluid-like (CSF-like: TC) signal fractions. Our findings showed that NAWM converting to WMHs already exhibited similar changes in tissue compositions at baseline to WMHs with lower TW and increased TC (fluid-like, i.e. free-water) and TG compared to persistent NAWM. We also found that microstructural properties of persistent NAWM were related to overall WMH burden with greater free-water content in patients with high WMH load. These findings suggest that NAWM preceding conversion to WMHs are accompanied by greater fluid-like properties indicating increased tissue water content. Increased GM-like properties may indicate a more isotropic microstructure of tissue reflecting a degree of hindered diffusion in NAWM regions vulnerable to WMH development. These results support the usefulness of microstructural compositions as a sensitive marker of NAWM vulnerability to WMH pathogenesis.

Mineral and organic matrix composition at bone forming surfaces in postmenopausal women with osteoporosis treated with either teriparatide or zoledronic acid.

The ability of bone to resist fracture is dependent on the composite nature of its mineral and organic matrix content. Teriparatide (TPTD) and zoledronic acid (ZOL) are approved anabolic and antiresorptive therapies, respectively, to reduce fracture risk in women with postmenopausal osteoporosis. In the SHOTZ study, postmenopausal women with osteoporosis were treated with TPTD (20 μg daily, subcutaneous) or ZOL (5 mg/year, intravenous infusion) for 24 months. Iliac crest biopsies were obtained at 6 months and again at 24 months from approximately one third of the original study cohort. To investigate the early effects of these two drugs on the quality of newly formed bone, we used vibrational spectroscopic techniques to analyze tetracycline-labelled transiliac biopsies obtained from participants at the 6-month time point. Raman spectra were acquired at forming trabecular and intra-cortical surfaces (identified by fluorescent double labels), to determine mineral, organic matrix, glycosaminoglycan, and tissue water content, as well as mineral maturity/crystallinity at three specific tissue ages (1-5, 15, and ≥25 days). Fourier transformed infrared microspectroscopy was used to determine pyridinoline/divalent collagen cross-link ratios. At 6 months, treatment with TPTD versus ZOL resulted in lower mineral and higher organic matrix content, increased tissue water content, and lower mineral/matrix, mineral maturity/crystallinity, glycosaminoglycan content, and pyridinoline/divalent enzymatic collagen cross-link ratio. Our results suggest that TPTD and ZOL have differential effects on material properties of newly formed bone at individual remodeling sites, highlighting their different mechanisms of action.

Laboratory and Field Assessment of the Frost Resistance of Sosnowsky’s Hogweed

The frost resistance of Sosnowsky’s hogweed plants (Heracleum sosnowsky Manden.) has been evaluated under laboratory and field conditions. The death of seedlings and adult plants observed within a temperature range from –6 to –12°C indicates low frost tolerance of the species. A snow cover provides a stable soil temperature (no less than –3°С) at the depth of renewal bud location and, therefore, provides the sustainability of meristematic potential in cenopopulations of H. sosnowsky. A shifting of freezing temperature for a H. sosnowsky meristem from –12°С (autumn) to –5 to –7°С (spring) is probably caused by the lack of a true dormancy stage and by changes in the content of cryoprotectors. Plant seeds also demonstrate reduced frost resistance after stratification (overwintering) and increased tissue water content. Field studies were carried out with assistance of volunteers within the framework of the “Moroz” (“Frost”) project arranged within the borders of the invasion habitat of the species in European Russia and based on the principles of citizen science. The results of the study show that the destruction of Sosnowsky’s hogweed plants after the snow cover removal depends only on weather conditions. Thus, elimination of H. sosnovsky stands by freezing can be recommended only for regions where average long-term minimum temperatures in January and February do not exceed –25°C; this method can be relevant for territories where the use of chemical herbicides is limited or prohibited.

Acute effect of multiple sets of fatiguing resistance exercise on muscle thickness, echo intensity, and extracellular-to-intracellular water ratio.

Resistance exercise (RE) causes an acute increase of the muscle thickness (MT) considered to relate to an increase in tissue water content. Segmental bioelectrical impedance spectroscopy (S-BIS) is a tool used to noninvasively assess intra- and extra-cellular water (ICW and ECW, respectively) of a given limb segment. The purpose of the present study was to examine the change of MT, ultrasound echo intensity (EI), ICW, and ECW after 3 sets of exhaustive RE. Eighteen untrained young males (age, 25.4 ± 4.1 years) performed RE consisting of 3 sets of knee extension concentric and eccentric contractions with 80% of 1-repetition maximum to failure. The MT and EI of the quadriceps measured by ultrasonography, and ECW/ICW ratio of the thigh assessed by S-BIS before (baseline) and after each set of RE (PostEx1, 2, and 3). The changes (Δ) in MT, EI, and ECW/ICW ratio were calculated as values of PostEx minus baseline values. The values of MT, EI, and ECW/ICW ratio at PostEx3 were significantly higher than baseline (effect size: MT, 1.11; EI, 0.47; and ECW/ICW ratio, 0.45). In addition, ΔMT was significantly and moderately correlated with ΔECW/ICW ratio (r = 0.61). Integrated data showed weak but significant correlation between ΔEI and ΔECW/ICW ratio as well (r = 0.31). The present results suggest multiple sets of exhaustive knee extension RE induce the acute increase of EI and ECW/ICW ratio as well as MT. The acute increase of muscle size after exercise can be at least partly explained by relative ECW increase.

CD200-CD200R imbalance correlates with microglia and pro-inflammatory activation in rat spinal cords exposed to amniotic fluid in retinoic acid-induced spina bifida

Spina bifida aperta is a congenital malformation characterized by the failure of neural tube closure resulting in an unprotected fetal spinal cord. The spinal cord then undergoes progressive damage, likely due to chemical and mechanical factors related to exposure to the intrauterine environment. Astrogliosis in exposed spinal cords has been described in animal models of spina bifida during embryonic life but its relationship with neuroinflammatory processes are completely unknown. Using a retinoic acid-induced rat model of spina bifida we demonstrated that, when exposed to amniotic fluid, fetal spinal cords showed progressive astrogliosis with neuronal loss at mid-gestation (E15) compared to unexposed spinal cords. The number of microglial cells with a reactive phenotype and activation marker expression increased during gestation and exhibited progressive disruption in the inhibitory immune ligand-receptor system. Specifically we demonstrate down-regulation of CD200 expression and up-regulation of CD200R. Exposed spinal cords demonstrated neuroinflammation with increased tissue water content and cytokine production by the end of gestation (E20), which correlated with active Caspase3 expression in the exposed layers. Our findings provide new evidence that microglia activation, including the disruption of the endogenous inhibitory system (CD200-CD200R), may participate in the pathogenesis of spina bifida through late gestation.

Quantitative MRI provides markers of intra-, inter-regional, and age-related differences in young adult cortical microstructure

Measuring the structural composition of the cortex is critical to understanding typical development, yet few investigations in humans have charted markers in vivo that are sensitive to tissue microstructural attributes. Here, we used a well-validated quantitative MR protocol to measure four parameters (R1, MT, R2*, PD*) that differ in their sensitivity to facets of the tissue microstructural environment (R1, MT: myelin, macromolecular content; R2*: myelin, paramagnetic ions, i.e., iron; PD*: free water content). Mapping these parameters across cortical regions in a young adult cohort (18–39 years, N = 93) revealed expected patterns of increased macromolecular content as well as reduced tissue water content in primary and primary adjacent cortical regions. Mapping across cortical depth within regions showed decreased expression of myelin and related processes – but increased tissue water content – when progressing from the grey/white to the grey/pial boundary, in all regions. Charting developmental change in cortical microstructure cross-sectionally, we found that parameters with sensitivity to tissue myelin (R1 & MT) showed linear increases with age across frontal and parietal cortex (change 0.5–1.0% per year). Overlap of robust age effects for both parameters emerged in left inferior frontal, right parietal and bilateral pre-central regions. Our findings afford an improved understanding of ontogeny in early adulthood and offer normative quantitative MR data for inter- and intra-cortical composition, which may be used as benchmarks in further studies.

P118. White matter macro- and microstructure alterations in preterm born adults

Introduction White matter (WM) injury, both macroscopic (visible on conventional MRI) and microscopic (detectable by diffusion tensor imaging, DTI) is frequent among preterm born infants investigated in later life ( Volpe, 2009 ). Degree and localization vary, but the corticospinal tract (CST) is often affected ( Eikenes et al., 2011 ). The relation between the micro- and macroscopic CST alterations has only been studied to our knowledge up to adolescence ( Bassi et al., 2011 , Estep et al., 2014 , Groeschel et al., 2014 ) but not in adults. We aimed to assess group differences in micro- and macroscopic WM integrity of the CST between preterm and full-term born adults and to evaluate the impact of macroscopic lesions onto the DTI parameters in and along the CST. Methods As part of a prospective study of preterm birth (Bavarian Longitudinal Study), we investigated adults at 26 years of age by means of MRI. Artifact-free DTI data were available from 51 full-term and 55 preterm born subjects ( Giorgio et al., 2010 ) and extracted DTI parameters (mean, axial, radial diffusivity - MD, AD, RD, and fractional anisotropy, FA) in the CST and slice-wise along the CST. On FLAIR-MRI images we identified macroscopic WM lesions as hyperintensities, noted their relation to the CST and correlated their presence with the DTI. Results and discussion WM hyperintensities, periventricular or in the corona radiata, were present in 9 of 51 (18%) full-term and 26 of 55 (47%) preterm born subjects. In 3 of 51 (6%) full-term and 17 of 55 (30%) preterm born subjects these ”lesions” affected the CST. Compared to full-term individuals, the preterm born subjects had significantly higher diffusivity (MD, AD, RD) in and along the CST but no difference in FA. These changes were weaker, but nevertheless remained significant when excluding subjects with macroscopic lesions. This suggests chronic CST injury with increased tissue water content ( Aung et al., 2013 ) even in the absence of visible WM lesions and points towards a high susceptibility of the CST after preterm birth.

New continuous-flow total artificial heart and vascular permeability

BackgroundWe tested the short-term effects of completely nonpulsatile versus pulsatile circulation after ventricular excision and replacement with total implantable pumps in an animal model on peripheral vascular permeability. MethodsTen calves underwent cardiac replacement with two HeartMate III continuous-flow rotary pumps. In five calves, the pump speed was rapidly modulated to impart a low-frequency pulse pressure in the physiologic range (10–25 mm Hg) at a rate of 40 pulses per minute (PP). The remaining five calves were supported with a pulseless systemic circulation and no modulation of pump speed (NP). Skeletal muscle biopsies were obtained before cardiac replacement (baseline) and on postoperative days (PODs) 1, 7, and 14. Skeletal muscle-tissue water content was measured, and morphologic alterations of skeletal muscle were assessed. VE-cadherin, phospho–VE-cadherin, and CD31 were analyzed by immunohistochemistry. ResultsThere were no significant changes in tissue water content and skeletal muscle morphology within group or between groups at baseline, PODs 1, 7, and 14, respectively. There were no significant alterations in the expression and/or distribution of VE-cadherin, phospho–VE-cadherin, and CD31 in skeletal muscle vasculature at baseline, PODs 1, 7, and 14 within each group or between the two groups, respectively. Although continuous-flow total artificial heart (CFTAH) with or without a pulse pressure caused slight increase in tissue water content and histologic damage scores at PODs 7 and 14, it failed to reach statistical significance. ConclusionsThere was no significant adherens-junction protein degradation and phosphorylation in calf skeletal muscle microvasculature after CFTAH implantation, suggesting that short term of CFTAH with or without pulse pressure did not cause peripheral endothelial injury and did not increase the peripheral microvascular permeability.

Terahertz spectroscopy for the study of paraffin-embedded gastric cancer samples

Terahertz (THz) spectroscopy constitute promising technique for biomedical applications as a complementary and powerful tool for diseases screening specially for early cancer diagnostic. The THz radiation is not harmful to biological tissues. As increased blood supply in cancer-affected tissues and consequent local increase in tissue water content makes THz technology a potentially attractive. In the present work, samples of healthy and adenocarcinoma-affected gastric tissue were analyzed using transmission time-domain THz spectroscopy (THz-TDS). The work shows the capability of the technique to distinguish between normal and cancerous regions in dried and paraffin-embedded samples. Plots of absorption coefficient α and refractive index n of normal and cancer affected tissues, are presented and the conditions for discrimination between normal and affected tissues are discussed.

Abstract W P32: Association of Low Cerebral Blood Volume With Negative FLAIR Hyperintensity in Acute Ischemic Stroke

Objective: FLAIR hyperintensity is being used in clinical trials as a surrogate imaging biomarker for stroke onset time to test the safety of thrombolysis. Studies have shown that patients with negative and positive FLAIR hyperintensity overlap at similar time points from stroke onset in the early phase of acute ischemic stroke (AIS). Hyperintensity on FLAIR MRI likely represents increased tissue water content. We sought to determine if cerebral blood volume (CBV) mediates FLAIR hyperintensity in the early phase of AIS. Methods: AIS patients seen in 2012 were included in the study if i) onset time was known, ii) an MRI with perfusion was performed within 12 hours of onset time, iii) had imaging confirmed vascular occlusion of ICA, M1, or M2. Following co-registration of raw perfusion images with FLAIR, CBV maps were generated using PMA ASIST™ software. Two raters blinded to clinical information separately evaluated the DWI, FLAIR and CBV maps and measured the signal intensity ratio (SIR) for the brightest region on FLAIR normalized by homologous contra-lateral tissue. The SIR was similarly measured for CBV in same region. FLAIR negative was defined as SIR&lt;1.15, “Low CBV” was defined as CBV SIR &lt;0.5. Results: One hundred eighty two patients were screened and 30 met all study criteria; 21 women, with mean age of 71 (± 16) years and median NIHSS 18 (IQR 9-22). Using linear regression analysis, CBV SIR was associated with FLAIR SIR (p &lt;0.049). In the 0-3hr time window, overall CBV was not associated with FLAIR hyperintensity. However, in the 3-7.5hr time window, patients with negative FLAIR were more likely to have low CBV and conversely, patients with positive FLAIR were more likely to have normal CBV. Conclusion: CBV likely mediates FLAIR hyperintensity in 3-7.5hr of stroke onset but it has less impact on FLAIR hyperintensity in the first 3 hours of AIS. Low CBV could be a potential surrogate imaging biomarker in addition to FLAIR hyperintensity in the early phase of AIS.

The potential of terahertz imaging for cancer diagnosis: A review of investigations to date.

The terahertz region lies between the microwave and infrared regions of the electromagnetic spectrum such that it is strongly attenuated by water and very sensitive to water content. Terahertz radiation has very low photon energy and thus it does not pose any ionization hazard for biological tissues. Because of these characteristic properties, there has been an increasing interest in terahertz imaging and spectroscopy for biological applications within the last few years and more and more terahertz spectra are being reported, including spectroscopic studies of cancer. The presence of cancer often causes increased blood supply to affected tissues and a local increase in tissue water content may be observed: this acts as a natural contrast mechanism for terahertz imaging of cancer. Furthermore the structural changes that occur in affected tissues have also been shown to contribute to terahertz image contrast. This paper introduces terahertz technology and provides a short review of recent advances in terahertz imaging and spectroscopy techniques. In particular investigations relating to the potential of terahertz imaging and spectroscopy for cancer diagnosis will be highlighted.

Do women's voices provide cues of the likelihood of ovulation? The importance of sampling regime.

The human voice provides a rich source of information about individual attributes such as body size, developmental stability and emotional state. Moreover, there is evidence that female voice characteristics change across the menstrual cycle. A previous study reported that women speak with higher fundamental frequency (F0) in the high-fertility compared to the low-fertility phase. To gain further insights into the mechanisms underlying this variation in perceived attractiveness and the relationship between vocal quality and the timing of ovulation, we combined hormone measurements and acoustic analyses, to characterize voice changes on a day-to-day basis throughout the menstrual cycle. Voice characteristics were measured from free speech as well as sustained vowels. In addition, we asked men to rate vocal attractiveness from selected samples. The free speech samples revealed marginally significant variation in F0 with an increase prior to and a distinct drop during ovulation. Overall variation throughout the cycle, however, precluded unequivocal identification of the period with the highest conception risk. The analysis of vowel samples revealed a significant increase in degree of unvoiceness and noise-to-harmonic ratio during menstruation, possibly related to an increase in tissue water content. Neither estrogen nor progestogen levels predicted the observed changes in acoustic characteristics. The perceptual experiments revealed a preference by males for voice samples recorded during the pre-ovulatory period compared to other periods in the cycle. While overall we confirm earlier findings in that women speak with a higher and more variable fundamental frequency just prior to ovulation, the present study highlights the importance of taking the full range of variation into account before drawing conclusions about the value of these cues for the detection of ovulation.

Hepatocyte growth factor suppresses ischemic cerebral edema in rats with microsphere embolism

The present study was aimed at determining whether human recombinant hepatocyte growth factor (HGF) ameliorates cerebral edema induced by microsphere embolism (ME). Rats were injected with 700 microspheres (48μm in diameter). Continuous administration of HGF at 13μg/3 days/animal into the right ventricle was started from 10min after embolism to the end of the experiment by using an osmotic pump. On day 3 after the ME, the rats were anesthetized, and their brains were perfused with an isotonic mannitol solution to eliminate constituents in the vascular and extracellular spaces. Thereafter, tissue water and cation contents were determined. A significant increase in tissue water content of the right hemisphere by ME was seen. This ME-induced increase in water content was associated with increases in tissue sodium and calcium ion contents and decreases in tissue potassium and magnesium ion contents of the right hemisphere. The treatment of the animal with HGF suppressed the increases in water and sodium and calcium ion contents, but not the decreases in potassium and magnesium ion contents. These results suggest that HGF suppresses the formation of ischemic cerebral edema provoked intracellularly in rats with ME.