Alterations In Water Content Research Articles

The effect of lime leaf extract (Citrus aurantifolia) through drinking water on the chemical and physical quality of broiler meat

This study aims to investigate the impact of supplementing lime leaf extract (EDJ) in broiler chickens' drinking water on both the chemical and physical qualities of their meat. A total of 128 New Lohmann MB 202 strain broiler roosters were subjected to the same basal feed regimen but received distinct drinking water treatments over a 35-day rearing period. The drinking water treatments included plain water without additives (negative control; T0), water supplemented with 50 ppm Tetracycline antibiotics (positive control; T1), water enriched with 15 ml/liter EDJ (T2), and water infused with 30 ml/liter EDJ (T3). The basal diet consisted of corn and soybean flour, with a crude protein content of 22.01% and a metabolic energy level of 3113.12 kcal/kg. Feed and drinking water are provided ad libitum during the rearing period. The parameters observed in this study were the chemical and physical quality of the meat, which included variables: moisture content, ash content, protein content, fat content, pH value, water holding capacity, cooking loss, and tenderness. The data obtained were then analyzed for variance (ANOVA) using a one-way Complete Randomized Design based on a P value of less than 5%. The findings of the study indicated that the supplementation of EDJ through drinking water did not produce significant alterations in water content, protein content, fat content, cooking loss, or tenderness of the broiler meat. However, a notable outcome was observed: the addition of 30 ml/liter of EDJ to the drinking water led to a substantial increase in water holding capacity (P<0.05) while simultaneously reducing the meat's pH value (P<0.05). These results suggest that EDJ supplementation has the potential to enhance the physical quality of broiler meat, primarily by increasing water retention and decreasing pH values, which can contribute to improve meat texture and juiciness.

The influence of water on size of the monodisperse polystyrene microspheres prepared by dispersion polymerization

AbstractPolystyrene microspheres with uniform sizes have a wide range of applications in biomedical engineering. However, detailed and systematic investigations on the influence of water content on alcohol/water systems are relatively scarce. In this study, the impact of trace water content on microsphere size was comprehensively examined, and a systematic exploration of the varying effects of different hydration levels on particle nucleation and growth mechanisms was conducted. When the water content increased from 0.1% to 0.4%, the microsphere diameter rapidly decreases from 3.6 to 2.71 μm. Correspondingly, the molecular weight increased from 29,797 to 69,186. However, within the water content range of 0.5%–14.5%, alterations in water content induced only slight variations in the microsphere diameter. The microsphere size, molecular weight, conversion rate, and reaction rate were compared in two stages. It was observed that the diminishing influence of water on the system was due to the changes in the main polymerization sites. Subsequently, the addition of water content up to 33.5% revealed an exponential decrease in the microsphere size with increasing water content in ethanol. This pattern was also observed in methanol and isopropanol, demonstrating its universality and predictability, making it applicable for precise prediction of microsphere size in different solvents.

Examining the Role of Magnetic Resonance Imaging (MRI) in Cerebral Ischemic Stroke: A Cross-Sectional Study

Objective: The aim of this study is to examine the role of Magnetic Resonance Imaging (MRI) when detecting cerebral ischemic stroke. Study design: A cross-sectional study Place and Duration: This study was conducted at Sandeman Provincial Hospital/ Bolan medical complex hospital Quetta, Quetta from March 2021 to March 2022 Methodology: Age and gender distribution of infarcts was done to find out the territory and location of the blood vessels involved. Overall, 52 individuals were involved in this research. Every patient was clinically suspected to have a cerebral ischemic stroke during the time span of our research. HDXT software with 1.5 Tesla 16 channel GE was used to perform the MRI scans. FLAIR axial, T1WI axial, T2WI axial and coronal, ADC maps, and gradient echo axial were the sequences used. SWI was optional. Results: The age group which was above 60 years included more percentage of males than females. It was seen that in the age group above 60 years, infarction was the most common and hypertension was the most common risk factor. Hemiplegia (Weakness) was seen to be the most common clinical presentation. It was seen that middle cerebral artery (MCA) territory infarcts had a slight rise on the right side. On the diffusion-weighted imaging (DWI), restricted diffusion was seen from subacute as well as acute infarcts along with a low apparent diffusion coefficient (ADC)valves. T2 FLAIR was normal in acute infarcts, but changes were reflected by DWI. Practical implication : Expanding the rationale for acute stroke thrombolysis may be more rationally accomplished by comprehending the clinical implications of numerous valuable MRI findings and thoroughly incorporating those factors into treatment decision-making. Conclusion: No radiation hazard is seen in MRI and it is non-invasive. The multiplanar imaging ability and grey-white resolution of the MRI perceive the subtle lesions. Infarcts are detected early due to the sensitivity of MRI to altered water content. Keywords: magnetic resonance imaging, stroke, cerebral infarcts,

Mapping microstructural gradients of the human striatum in normal aging and Parkinson's disease.

Mapping structural spatial change (i.e., gradients) in the striatum is essential for understanding the function of the basal ganglia in both health and disease. We developed a method to identify and quantify gradients of microstructure in the single human brain in vivo. We found spatial gradients in the putamen and caudate nucleus of the striatum that were robust across individuals, clinical conditions, and datasets. By exploiting multiparametric quantitative MRI, we found distinct, spatially dependent, aging-related alterations in water content and iron concentration. Furthermore, we found cortico-striatal microstructural covariation, showing relations between striatal structural gradients and cortical hierarchy. In Parkinson’s disease (PD) patients, we found abnormal gradients in the putamen, revealing changes in the posterior putamen that explain patients’ dopaminergic loss and motor dysfunction. Our work provides a noninvasive approach for studying the spatially varying, structure-function relationship in the striatum in vivo, in normal aging and PD.

Longitudinal microstructural MRI markers of demyelination and neurodegeneration in early relapsing-remitting multiple sclerosis: Magnetisation transfer, water diffusion and g-ratio

IntroductionQuantitative microstructural MRI, such as myelin-sensitive magnetisation transfer ratio (MTR) or saturation (MTsat), axon-sensitive water diffusion Neurite Orientation Dispersion and Density Imaging (NODDI), and the aggregate g-ratio, may provide more specific markers of white matter integrity than conventional MRI for early patient stratification in relapsing-remitting multiple sclerosis (RRMS). The aim of this study was to determine the sensitivity of such markers to longitudinal pathological change within cerebral white matter lesions (WML) and normal-appearing white matter (NAWM) in recently diagnosed RRMS. MethodsSeventy-nine people with recently diagnosed RRMS, from the FutureMS longitudinal cohort, were recruited to an extended MRI protocol at baseline and one year later. Twelve healthy volunteers received the same MRI protocol, repeated within two weeks. Ethics approval and written informed consent were obtained.3T MRI included magnetisation transfer, and multi-shell diffusion-weighted imaging. NAWM and whole brain were segmented from 3D T1-weighted MPRAGE, and WML from T2-weighted FLAIR. MTR, MTsat, NODDI isotropic (ISOVF) and intracellular (ICVF) volume fractions, and g-ratio (calculated from MTsat and NODDI data) were measured within WML and NAWM. Brain parenchymal fraction (BPF) was also calculated.Longitudinal change in BPF and microstructural metrics was assessed with paired t-tests (α = 0.05) and linear mixed models, adjusted for confounding factors with False Discovery Rate (FDR) correction for multiple comparisons. Longitudinal changes were compared with test-retest Bland-Altman limits of agreement from healthy control white matter. The influence of longitudinal change on g-ratio was explored through post-hoc analysis in silico by computing g-ratio with realistic simulated MTsat and NODDI values. ResultsIn NAWM, g-ratio and ICVF increased, and MTsat decreased over one year (adjusted mean difference = 0.007, 0.005, and −0.057 respectively, all FDR-corrected p < 0.05). There was no significant change in MTR, ISOVF, or BPF. In WML, MTsat, NODDI ICVF and ISOVF increased over time (adjusted mean difference = 0.083, 0.024 and 0.016, respectively, all FDR-corrected p < 0.05). Group-level longitudinal changes exceeded test-retest limits of agreement for NODDI ISOVF and ICVF in WML only. In silico analysis showed g-ratio may increase due to a decrease in MTsat or ISOVF, or an increase in ICVF. DiscussionG-ratio and MTsat changes in NAWM over one year may indicate subtle myelin loss in early RRMS, which were not apparent with BPF or NAWM MTR. Increases in NAWM and WML NODDI ICVF were not anticipated, and raise the possibility of axonal swelling or morphological change. Increases in WML MTsat may reflect myelin repair. Changes in NODDI ISOVF are more likely to reflect alterations in water content. Competing MTsat and ICVF changes may account for the absence of g-ratio change in WML. Longitudinal changes in microstructural measures are significant at a group level, however detection in individual patients in early RRMS is limited by technique reproducibility. ConclusionMTsat and g-ratio are more sensitive than MTR to early pathological changes in RRMS, but complex dependence of g-ratio on NODDI parameters limit the interpretation of aggregate measures in isolation. Improvements in technique reproducibility and validation of MRI biophysical models across a range of pathological tissue states are needed.

Characterization of expansive soils for the foundation of an irrigation canal in the Peruvian Andes, Cabana-Mañazo case

Alterations in water content in swelling soils cause volume variation, which implies constructive, socioeconomic and environmental damage. This paper characterizes the swelling soil located in an irrigation canal of the Peruvian Altiplano and its behavior of the properties by addition of lime in 5, 10, 15 and 20% of the total weight. Finding that the sample of the station 6+575 has combined presence of montmorillonite clays in a percentage of 13.52% together with the group of kaolinites in a percentage of 1.31%, consequently, it makes expandable clay of high plasticity. The soils of the station 6+250 have the characteristics of kaolinite clay, which distinguishes it as having low plasticity. In the swelling tests the high expansiveness was found, in the station 6+575, which has decreased with the addition of lime. Considering that concrete canals are generally of small thickness it would be important to consider the slightly dangerous effects on irrigation infrastructure.

Expression and functional maintenance of volume-regulated anion channels in myometrial smooth muscles of pregnant mice.

Pregnancy causes changes in the uterus, such as increased cell volume and altered water content. However, the mechanisms that protect the structure and maintain the function of uterine smooth muscle cells against these changes during pregnancy have not been clarified. This study focused on the volume-regulated anion channel (VRAC), which opens with cell swelling under low osmotic pressure and releases Cl– ions and various organic osmolytes to resist cell swelling and regulates a wide range of biological processes such as cell death. In this study, myometrial smooth muscle (MSM) tissues and cells (MSMCs) were collected from non-pregnant and pregnant mice. Using western blotting and immunocytochemistry, leucine-rich repeat containing protein 8A (LRRC8A), an essential membrane protein that constitutes part of the VRAC, was determined to be diffused throughout MSMCs including in the cell membrane. Patch-clamp experiments were performed to investigate the electrophysiology of swelling-induced Cl– currents (ICl, swell) mediated by the VRAC. No significant changes between non-pregnancy and pregnancy groups were observed in either the expression density of LRRC8A or the current density of ICl, swell, however the presence of LRRC8A on the cell membrane was significantly increased in the third trimester of pregnancy compared to the non-pregnancy. This study suggests that the VRAC may play a role, such as maintaining cellular homeostasis in the pregnant MSM.

Impact of soil moisture on cesium uptake by plants: Model assessment

Computational models of radioisotopes soil-to-plant transfer are an essential component of decision support systems for nuclear emergency and assessment impact of nuclear accidents on human beings and the environment. The soil water regime impact on cations behavior in the «soil-plant » system. Therefore, relationships between radioisotopes accumulation by plants and soil moisture should be included in the computational models. A kinetic model for simulation of Cs+ root uptake under alteration of soil moisture content in soil is presented in this paper. The model simulates Cs+ and K+ diffusion from bulk soil into rhizosphere under alteration of water content. The model results show a drop of Cs+ and K+ concentration in the rhizosphere with decreasing soil moisture. The magnitude of enhanced root uptake of Cs+ with soil moisture alteration depends on the exchangeable potassium content and soil texture. The Cs+ root uptake rate has a maximum at 60%–80% of field capacity under sufficient and high exchange potassium content. A similar dependence should also be seen for the RCs soil-to-plant transfer factor. The results indicate the importance of soil water content for modification of the RCs accumulation by plants and the necessity to include this factor into an appropriate semi-mechanistic model.

Effect of storage and preconditioning of healing rat Achilles tendon on structural and mechanical properties

Tendon tissue storage and preconditioning are often used in biomechanical experiments and whether this generates alterations in tissue properties is essential to know. The effect of storage and preconditioning on dense connective tissues, like tendons, is fairly understood. However, healing tendons are unlike and contain a loose connective tissue. Therefore, we investigated if storage of healing tendons in the fridge or freezer changed the mechanical properties compared to fresh tendons, using a pull-to-failure or a creep test. Tissue morphology and cell viability were also evaluated. Additionally, two preconditioning levels were tested. Rats underwent Achilles tendon transection and were euthanized 12 days postoperatively. Statistical analyzes were done with one-way ANOVA or Student’s t-test. Tissue force and stress were unaltered by storage and preconditioning compared to fresh samples, while high preconditioning increased the stiffness and modulus (p ≤ 0.007). Furthermore, both storage conditions did not modify the viscoelastic properties of the healing tendon, but altered transverse area, gap length, and water content. Cell viability was reduced after freezing. In conclusion, preconditioning on healing tissues can introduce mechanical data bias when having extensive tissue strength diversity. Storage can be used before biomechanical testing if structural properties are measured on the day of testing.

Dramatic change of bacterial assembly process and co-occurrence pattern in Spartina alterniflora salt marsh along an inundation frequency gradient

Exotic Spartina alterniflora has become widely distributed along most of the coastlines in China in a wide range of inundation frequencies. However, the assembly processes and co-occurrence patterns of the bacterial community in S. alterniflora wetlands under different inundation frequencies remain elusive. In this study, an in-situ mesocosm was established to investigate the changes in soil bacterial community. We found that soil water content was the most decisive factor in influencing the bacterial community. Balanced variation, rather than abundance gradients, accounted for the major shifts in bacterial communities and was significantly and positively correlated with the changes in water content, suggesting that species substitution was facilitated by the increased water content. Deterministic processes were dominant in community assembly, and a large degree of change in water content increased variable selection. Co-occurrence network revealed that increasing water content significantly decreased the average degree and the relative abundance of keystone species, resulting in a network with less complexity. Structural equation modelling suggests that increasing inundation frequency has strong impacts on bacterial community, primarily by altering water content, network degree, and the relative abundance of keystone species. Overall, our results illustrate that increasing inundation frequency significantly influences the bacterial community assembly processes and co-occurrence patterns.

Hormonal regulation and redox reaction of maize under partial root drying irrigation

How three different irrigation regimes, conventional irrigation (CI), partial root drying (PRD), and deficit irrigation (DI), on endogenous hormonal abscisic acid (ABA) and zeatin-riboside (ZR) changes, stomatal conductance (gs), reactive oxygen species (ROS), antioxidant enzyme activities, and metabolism of non-enzymatic compounds was assessed. This investigation revealed that the root-sourced chemical signals induced by PRD irrigation reduced the gs without any altered relative water content (RWC) in leaves, and further analysis found that stress-triggered ABA could induce stomatal closure; however, ZR exhibited antagonistic effects on the accumulation and stomatal regulation of ABA. Thus, in the current study, gs was more responsive to the combined ABA/ZR signal than ABA signal solely. Both PRD and DI treatments increased the production rate of superoxide anion ( $$ {\text{O}}_{2}^{ \bullet - } $$ ) as well as hydrogen peroxide (H2O2) concentration in root and leaf tissues under stress conditions; however, the superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities significantly increased under PRD irrigation. Moreover, compared with DI regime, PRD irrigation caused less proline and malondialdehyde (MDA) accumulation in stressed root and leaf tissues, suggesting that PRD irrigation technique alleviated the stress-induced physiological damage. Consequently, compared to CI, the leaf area and whole-plant dry weight in maize were unchanged under PRD irrigation but reduced significantly under DI treatment.

Water-content related alterations in macro and micro scale tendon biomechanics

Though it is known that the water content of biological soft tissues alters mechanical properties, little attempt has been made to adjust the tissue water content prior to biomechanical testing as part of standardization procedures. The objective of this study was to examine the effects of altered water content on the macro and micro scale mechanical tissues properties. Human iliotibial band samples were obtained during autopsies to osmotically adapt their water content. Macro mechanical tensile testing of the samples was conducted with digital image correlation, and micro mechanical tests using atomic force microscopy. Analyses were conducted for elastic moduli, tensile strength, and strain at maximum force, and correlations for water content, anthropometric data, and post-mortem interval. Different mechanical properties exist at different water concentrations. Correlations to anthropometric data are more likely to be found at water concentrations close to the native state. These data underline the need for adapting the water content of soft tissues for macro and micro biomechanical experiments to optimize their validity. The osmotic stress protocol provides a feasible and reliable standardization approach to adjust for water content-related differences induced by age at death, post-mortem interval and tissue processing time with known impact on the stress-strain properties.

The Effect of Psyllium Husk on Intestinal Microbiota in Constipated Patients and Healthy Controls.

Psyllium is a widely used treatment for constipation. It traps water in the intestine increasing stool water, easing defaecation and altering the colonic environment. We aimed to assess the impact of psyllium on faecal microbiota, whose key role in gut physiology is being increasingly recognised. We performed two randomised, placebo-controlled, double-blinded trials comparing 7 days of psyllium with a placebo (maltodextrin) in 8 healthy volunteers and 16 constipated patients respectively. We measured the patients’ gastrointestnal (GI) transit, faecal water content, short-chain fatty acid (SCFA) and the stool microbiota composition. While psyllium supplement had a small but significant effect on the microbial composition of healthy adults (increasing Veillonella and decreasing Subdoligranulum), in constipated subjects there were greater effects on the microbial composition (increased Lachnospira, Faecalibacterium, Phascolarctobacterium, Veillonella and Sutterella and decreased uncultured Coriobacteria and Christensenella) and alterations in the levels of acetate and propionate. We found several taxa to be associated with altered GI transit, SCFAs and faecal water content in these patients. Significant increases in three genera known to produce butyrate, Lachnospira, Roseburia and Faecalibacterium, correlated with increased faecal water. In summary, psyllium supplementation increased stool water and this was associated with significant changes in microbiota, most marked in constipated patients.

Preparation of a graphene oxide/faujasite composite adsorbent

Template-free synthesis of faujasite type zeolite was investigated in the presence of graphene oxide (GO) in the synthesis sol. Nano-sized FAU/EMT, nano-sized FAU, and micro-sized FAU can be obtained depending on synthesis conditions such as precursor molar ratios, crystallization temperature, and the use of freeze-drying to alter water content. The obtained GO/Faujasite powder was shaped in the form of a disk by vacuum filtration. The shaped GO/Faujasite powder is electrically conductive (∼0.4 S/m & 2000–3000 Ω/sq), mechanically stable (Young's modulus: ∼7 MPa) and contains micropores, mesopores, and macropores. Furthermore, the GO/Faujasite disk exhibits high methylene blue adsorption capacity and can be regenerated by thermal annealing at 300 °C without significant capacity loss.

Response of the photosynthetic apparatus in cucumber leaves to daily short-term temperature drops

Responses of the photosynthetic apparatus in cucumber (Cucumis sativus L.) leaves were examined after exposing the plants to daily short-term temperature drops to 12°C (for 2 h at the end of night periods, DROP treatment) during active leaf growth (DROPI) and at the mature leaf stage (DROPII). The DROP treatment induced adaptive changes in the photosynthetic apparatus that were evident in elevated photosynthetic activity at low temperature, modified composition of pigments, altered water content in leaves, and altered ratio of leaf dry matter to leaf area. The stage of leaf development had a significant influence on the responses of photosynthetic apparatus to DROP treatments. The leaves subjected to DROP during active growth were capable of large structural rearrangements, which provided a larger increase in resistance of photosynthesis to low temperature, whereas the leaves exposed to temperature drops at the mature leaf state were characterized by the reduced capacity for acclimation.

Magnetic resonance imaging cooling-reheating protocol indicates decreased fat fraction via lipid consumption in suspected brown adipose tissue.

ObjectivesTo evaluate whether a water-fat magnetic resonance imaging (MRI) cooling-reheating protocol could be used to detect changes in lipid content and perfusion in the main human brown adipose tissue (BAT) depot after a three-hour long mild cold exposure.Materials and MethodsNine volunteers were investigated with chemical-shift-encoded water-fat MRI at baseline, after a three-hour long cold exposure and after subsequent short reheating. Changes in fat fraction (FF) and R2*, related to ambient temperature, were quantified within cervical-supraclavicular adipose tissue (considered as suspected BAT, denoted sBAT) after semi-automatic segmentation. In addition, FF and R2* were quantified fully automatically in subcutaneous adipose tissue (not considered as suspected BAT, denoted SAT) for comparison. By assuming different time scales for the regulation of lipid turnover and perfusion in BAT, the changes were determined as resulting from either altered absolute fat content (lipid-related) or altered absolute water content (perfusion-related).ResultssBAT-FF decreased after cold exposure (mean change in percentage points = -1.94 pp, P = 0.021) whereas no change was observed in SAT-FF (mean = 0.23 pp, P = 0.314). sBAT-R2* tended to increase (mean = 0.65 s-1, P = 0.051) and SAT-R2* increased (mean = 0.40 s-1, P = 0.038) after cold exposure. sBAT-FF remained decreased after reheating (mean = -1.92 pp, P = 0.008, compared to baseline) whereas SAT-FF decreased (mean = -0.79 pp, P = 0.008, compared to after cold exposure).ConclusionsThe sustained low sBAT-FF after reheating suggests lipid consumption, rather than altered perfusion, as the main cause to the decreased sBAT-FF. The results obtained demonstrate the use of the cooling-reheating protocol for detecting changes in the cervical-supraclavicular fat depot, being the main human brown adipose tissue depot, in terms of lipid content and perfusion.

T1ρ imaging in premanifest Huntington disease reveals changes associated with disease progression.

Imaging biomarkers sensitive to Huntington's disease (HD) during the premanifest phase preceding motor diagnosis may accelerate identification and evaluation of potential therapies. For this purpose, quantitative MRI sensitive to tissue microstructure and metabolism may hold great potential. We investigated the potential value of T1ρ relaxation to detect pathological changes in premanifest HD (preHD) relative to other quantitative relaxation parameters. Quantitative MR parametric mapping was used to assess differences between 50 preHD subjects and 26 age- and sex-matched controls. Subjects with preHD were classified into two progression groups based on their CAG-age product (CAP) score; a high and a low/moderate CAP group. Voxel-wise and region-of-interest analyses were used to assess changes in the quantitative relaxation times. T1ρ showed a significant increase in the relaxation times in the high-CAP group, as compared to controls, largely in the striatum. The T1ρ changes in the preHD subjects showed a significant relationship with CAP score. No significant changes in T2 or T2* relaxation times were found in the striatum. T2* relaxation changes were found in the globus pallidus, but no significant changes with disease progression were found. These data suggest that quantitative T1ρ mapping may provide a useful marker for assessing disease progression in HD. The absence of T2 changes suggests that the T1ρ abnormalities are unlikely owing to altered water content or tissue structure. The established sensitivity of T1ρ to pH and glucose suggests that these factors are altered in HD perhaps owing to abnormal mitochondrial function.

Magnetic Resonance Imaging of the Hand and Wrist: Techniques and Spectrum of Disease

Magnetic resonance imaging (MRI) is an excellent imaging modality for the evaluation of pathologic processes of the hand and wrist. MRI of the hand and wrist provides high-resolution imaging of osseous structures and soft-tissue structures (including ligaments, tendons, nerves, and muscles) through the use of multiple imaging techniques and pulse sequences. This article updates orthopaedic surgeons on current MRI techniques and illustrates the spectrum of hand and wrist disease detectable by MRI. We searched PubMed with use of the keywords “MRI” plus “hand” or “wrist” for studies less than five years old evaluating MRI techniques. On the basis of a review of the recently published literature and the authors’ experience, we define and describe the applications of the following: (1) conventional, non-gadolinium-enhanced MRI, (2) gadolinium-enhanced MRI, and (3) MR arthrography. We also describe the classic MRI appearance of lesions commonly evaluated by MRI, including occult fracture, triangular fibrocartilage complex injury, interosseous ligament injury, extrinsic carpal ligament injury, thumb ulnar collateral ligament injury, traumatic tendon injury, finger pulley injury, ulnar impaction syndrome, tendinopathy, Kienbock disease, posttraumatic scaphoid osteonecrosis, infection, inflammatory arthropathy, compression neuropathy, and various soft-tissue masses. The incorporation of dedicated surface coils and higher-strength magnets has improved the quality of magnetic resonance imaging (MRI) scanners substantially over the last decade. By manipulating the scanning parameters when performing an MRI examination, contrast differences between tissues can be emphasized on the basis of inherent tissue properties known as T1 and T2. T1-weighted images are generally regarded as best for illustrating anatomic detail. T2-weighted sequences highlight alterations in water content, which are characteristic of most pathologic conditions. Short tau inversion recovery (STIR) and fat-suppressed T2-weighted images accentuate fluid and edema and are the most sensitive for detecting pathologic changes in both bone and soft tissue. The intravenous administration of a gadolinium-based contrast agent …

Heat shock proteins contribute to mosquito dehydration tolerance

This study examines the responses of heat shock protein transcripts, Hsp70 and Hsp90, to dehydration stress in three mosquito species, Aedes aegypti, Anopheles gambiae and Culex pipiens. We first defined the water balance attributes of adult females of each species, monitored expression of the hsp transcripts in response to dehydration, and then knocked down expression of the transcripts using RNA interference (RNAi) to evaluate potential functions of the Hsps in maintenance of water balance. Fully hydrated females of all three species contained nearly the same amount of water (66-68%), but water loss rates differed among the species, with A. aegypti having the lowest water loss rate (2.6%/h), followed by C. pipiens (3.3%/h), and A. gambiae (5.1%/h). In all three species water could be replaced only by drinking water (or blood). Both A. aegypti and C. pipiens tolerated a loss of 36% of their body water, but A. gambiae was more vulnerable to water loss, tolerating a loss of only 29% of its body water. Dehydration elicited expression of hsp70 in all three species, but only C. pipiens continued to express this transcript during rehydration. Hsp90 was constitutively expressed and expression levels remained fairly constant during dehydration and rehydration, except expression was not noted during rehydration of C. pipiens. Injection of dsRNA to knock down expression of hsp70 (83% reduction) and hsp90 (46% reduction) in A. aegypti did not alter water content or water loss rates, but the dehydration tolerance was lower. Instead of surviving a 36% water loss, females were able to survive only a 28% water loss in response to RNAi directed against hsp70 and a 26% water loss when RNAi was directed against hsp90. These results indicate a critical function for these Hsps in mosquito dehydration tolerance.

Separation of healthy and early osteoarthritis by automatic quantification of cartilage homogeneity

Cartilage loss as determined either by magnetic resonance imaging (MRI) or by joint space narrowing in X-rays is the result of cartilage erosion. However, metabolic processes within the cartilage that later result in cartilage loss may be a more accurate assessment method for early changes. Early biological processes of cartilage destruction are among other things, a combination of proteoglycan turnover, as a result of altered charge distributions, and local alterations in water content (edema). As water distribution is detectable by MRI, the aim of this study was to investigate cartilage homogeneity visualized by MRI related to water distribution, as a potential very early marker for early detection of knee osteoarthritis (OA). One hundred and fourteen right and left knees from 71 subjects aged 22-79 years were scanned using a Turbo 3D T(1) sequence on a 0.18T MRI Esaote scanner. The medial compartment of the tibial cartilage sheet was segmented using a fully automatic voxel classification scheme based on supervised learning. From the segmented cartilage sheet, homogeneity was quantified by measuring entropy from the distribution of signal intensities inside the compartment. For each knee an X-ray was acquired and the knees were categorized by the Kellgren and Lawrence (KL) index and the joint space width (JSW) was measured. The P-values for separating the groups by each of JSW, cartilage volume, cartilage mean intensity, and cartilage homogeneity were calculated using the unpaired t-test. The P-value for separating the group diagnosed as KL 0 from the group being KL 1 based on JSW, volume and mean signal intensity the values were P=0.9, P=0.4 and P=0.0009, respectively. In contrast, the P-value for homogeneity was P=0.0004. The precision of the measures assessed, as a test-retest root mean square coefficient of variation (RMS-CV%) was 3.9% for JSW, 7.4% for volume, 3.9% for mean signal intensity and 3.0% for homogeneity quantification. These data demonstrate that the distribution of components of the articular matrix precedes erosion, as measured by cartilage homogeneity related to water concentration. We show that homogeneity was able to separate early OA from healthy individuals in contrast to traditional volume and JSW quantifications. These data suggest that cartilage homogeneity quantification may be able to quantify early biochemical changes in articular cartilage prior to cartilage loss and thereby provide better identification of patients for OA trials who may respond better to medicinal intervention of some treatments. In addition, this study supports the feasibility of using low-field MRI in clinical studies.