Local variation in absolute water content of human and rabbit eye lenses measured by Raman microspectroscopy

Raman spectra were obtained from fresh, fixed and sliced rabbit lenses and from human lens slices. For all lenses and lens slices the ratio R, defined as the Raman intensity at 3390 cm−1 divided by the Raman intensity at 2935 cm−1, was measured at different locations along the visual and equatorial axis. The ratios R were transformed to absolute water mass percentages by measuring solutions with known protein concentrations. It was shown that fixation and slicing have very little effect on the absolute water content of the lenses. The values obtained for the absolute water content are comparable to values given in literature. It was also shown that the water content in rabbit and human lenses rapidly decreases from the immediate anterior and posterior subsurface region to the deep superficial cortex and is relatively constant in the nucleus. Raman microspectroscopy appears to be a reliable method for the measurement of the absolute water content of small volumes on defined positions in the lens. This can be very useful when analyzing the possible relation between local variations in water content and the occurrence of opacities in the lens

Raman microspectroscopy of fixed rabbit and human lenses and lens slices: New potentialities

Raman spectroscopy is a non-invasive, non-destructive technique for the study of the macromolecular composition of tissues. Raman spectra were obtained from intact fresh and paraformaldehyde fixed rabbit lenses and from thin slices prepared from these lenses. In addition the Raman spectrum of an intact 82-yr-old human lens was compared with a slice of the same lens. It appeared that fixation with paraformaldehyde had only a minor qualitative effect on the Raman spectra and that Raman spectra of intact lenses and lens slices were comparable. It was also shown that in the slice of the old human lens the fluorescence, due to chromophores, could be reduced so that a reliable Raman spectrum could be obtained.\ud \ud The use of slices improves the accuracy of the position at which Raman spectra are recorded and fixation extends the time available for Raman analysis which is particularly important for the study of human lenses. Moreover, slicing enables Raman analysis of old human lenses, which up to now was thought to be impossible due to the overwhelming fluorescence of the chromophores present in these lenses

Range-depths tracking of multiple sperm whales over large distances using a two-element vertical array and rhythmic properties of clicks-trains

International audienceSperm whales (Physeter macrocephalus) have followed fishing vessels off the Alaskan coast for decades, in order to remove sablefish ("depredate") from longlines. The Southeast Alaska Sperm Whale Avoidance Project (SEASWAP) has found that whales respond to distinctive acoustic cues made by hauling fishing vessels, as well as to marker buoys on the surface. Between 15-17 August 2010 a simple two-element vertical array was deployed off the continental slope of Southeast Alaska in 1200 m water depth. The array was attached to a longline fishing buoyline at 300 m depth, close to the sound-speed minimum of the deep-water profile. The buoyline also served as a depredation decoy, attracting seven sperm whales to the area. One animal was tagged with both a LIMPET dive depthtransmitting satellite and bioacoustic B-probe tag. Both tag datasets were used as an independent check of a passive acoustic scheme for tracking the whale in depth and range, which exploited the elevation angles and relative arrival times of multiple ray paths recorded on the array. The localization approach doesnt require knowledge of the local bottom bathymetry. Numerical propagation models yielded accurate locations up to at least 35 km range at Beaufort sea state 3. Ongoing work includes combining the arrival angle information with an algorithm developed by Le Bot et al. [1] that uses the rhythmic properties of odontocet click trains to separate interleaved click trains. This approach will improve our localization capabilities in presence of multiple sperm whales. In order to achieve better separation of interleaved click trains it is possible to use machine learning based algorithms. This new concept is based on finding useful information hidden in a large database. This useful information can then be represented by a sparse subspace. The first step of the approach is to extract informative features with a new detector proposed by Dadouchi et al. [2]. Once the dictionary of features is learned, any signal of this considered dataset can be approximated sparsely. By reducing the dimensional space, the sparse representation has the advantage to provide an optimally representation of the data. [Work supported by the North Pacific Research Board, the Alaska SeaLife Center, ONR, NOAA and ANR-12-ASTR-0021-03 "MER CALME"

Individual differences in the use of the response scale determine valuations of hypothetical health states: an empirical study

ABSTRACT: BACKGROUND: The literature remains inconclusive about the effects of socio-demographic characteristics of the respondent, including age, on valuation scores of hypothetical health states. We analyzed data from a study designed to discriminate between the effects of respondents age and time preference on valuations of health states to get insight in the contribution of individual response patterns to the variance in valuation scores. METHODS: 212 respondents from different age groups valued six hypothetical health states with three methods: a Visual Analogue Scale (VAS) and two variants of the Time trade-off (TTO). Analyses included a generalizability study, principal components analysis and cluster analysis. RESULTS: Valuation scores differed significantly but not systematically between valuation methods. A total of 36.8% of variance was explained by health states, 1.6% by elicitation method and 0.2% by age group. Individual differences in the use of the response scales, e.g. a tendency to give either high or low TTO-scores, or a high or low scoring tendency on the VAS were the main source of remaining variance. These response patterns were not related to age or other identifiable respondent characteristics. CONCLUSIONS: We conclude that individual response patterns were more important determinants of TTO or VAS valuations of health states than age or other measured respondent characteristics. Further valuation research should focus on explaining individual response patterns as a possible key to understanding the determinants of health state valuations

Agricultural Microcredit and Household Vulnerability in Rural Malawi

textabstractSixteen girls with Turner syndrome (TS) were treated for 4 years with biosynthetic growth hormone (GH). The dosage was 4IU/m2 body surface s.c. per day over the first 3 years. In the 4th year the dosage was increased to 61 U/m2 per day in the 6 girls with a poor height increment and in 1 girl oxandrolone was added. Ethinyl oestradiol was added after the age of 13. Mean (SD) growth velocities were 3.4 (0.9), 7.2 (1.7), 5.3 (1.3), 4.3 (2.0) and 3.6 (1.5) cm/year before and in the 1st, 2nd, 3rd and 4th year of treatment. Skeletal maturation advanced faster than usual in Turner patients especially in the youger children. Although the mean height prediction increased by 5.6 cm and 11 of the 16 girls have now exceeded their predicted height, the height of the 4 girls who stopped GH treatment exceeded the predicted adult height by only 0 to 3.4 cm

Intraoperative visualisation and treatment of salivary glands in Sjögren's syndrome by contrast-enhanced ultrasound sialendoscopy (CEUSS):protocol for a phase I single-centre, single-arm, exploratory study

INTRODUCTION: We established a promising sialendoscopic treatment for in vivo enhancement of salivation in salivary glands affected by Sjögren's syndrome (SS). In this technique, the ducts of the salivary glands are irrigated with saline and steroids. This allows for dilatation of ductal strictures and removal of debris. Unfortunately, it is not possible to assess the delivery and penetration of saline or medications in the ductal system and parenchyma. To address this problem, we will conduct contrast-enhanced ultrasound sialendoscopy (CEUSS) using sulphur hexafluoride microbubbles. To the best of our knowledge, microbubbles have never been used for the treatment of salivary glands in SS. It is, therefore, imperative to test this application for its safety and feasibility. METHODS AND ANALYSIS: A single-arm phase I study will be performed in 10 SS patients. Under local anaesthesia, ultrasound (US) guided infusion of the parotid and submandibular glands with microbubbles will be performed. Continuous US imaging will be used to visualise the glands, including the location of strictures and occlusions. Main outcomes will be the evaluation of safety and technical feasibility of the experimental treatment. Secondary outcomes will consist of determinations of unstimulated whole mouth saliva flow, stimulated whole mouth saliva flow, stimulated parotid saliva flow, clinical oral dryness, reported pain, xerostomia, disease activity, salivary cytokine profiles and clinical SS symptoms. Finally, salivary gland topographical alterations will be evaluated by US. ETHICS AND DISSEMINATION: Ethical approval for this study was obtained from the Medical Ethics Committee of the Amsterdam University Medical Centre, Amsterdam, The Netherlands (NL68283.029.19). data will be presented at national and international conferences and published in a peer-reviewed journal. The study will be implemented and reported in line with the Standard Protocol Items: Recommendations for Interventional Trials' statement. TRIAL REGISTRATION NUMBERS: The Netherlands Trial Register: NL7731, MREC Trial Register: NL68283.029.19; Pre-results

Interexaminer Agreement and Reliability of an Internationally Endorsed Screening Framework for Cervical Vascular Risks Following Manual Therapy and Exercise:The Go4Safe Project

Objective: Clinicians are recommended to use the clinical reasoning framework developed by the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) to provide guidance regarding assessment of the cervical spine and potential for cervical artery dysfunction prior to manual therapy and exercise. However, the interexaminer agreement and reliability of this framework is unknown. This study aimed to estimate the interexaminer agreement and reliability of the IFOMPT framework among physical therapists in primary care. Methods: Ninety-six patients who consulted a physical therapist for neck pain or headache were included in the study. Each patient was tested independently by 2 physical therapists, from a group of 17 physical therapists (10 pairs) across The Netherlands. Patients and examiners were blinded to the test results. The overall interexaminer agreement, specific agreement per risk category (high-, intermediate-, and low-risk), and interexaminer reliability (weighted κ) were calculated. Results: Overall agreement was 71% (specific agreement in high-risk category = 63%; specific agreement in intermediate-risk category = 38%; specific agreement in low-risk category = 84%). Overall reliability was moderate (weighted κ = 0.39; 95% CI = 0.21-0.57) and varied considerably between pairs of physical therapists (κ = 0.14-1.00). Conclusion: The IFOMPT framework showed an insufficient interexaminer agreement and fair interexaminer reliability among physical therapists when screening the increased risks for vascular complications following manual therapy and exercise prior to treatment. Impact: The IFOMPT framework contributes to the safety of manual therapy and exercise. It is widely adopted in clinical practice and educational programs, but the measurement properties are unknown. This project describes the agreement and reliability of the IFOMPT framework

Regulation of chloride transport in cultured normal and cystic fibrobis keratinocytes

Abstract Cultured normal (N) and cystic fibrosis (CF) keratinocytes were evaluated for their Cl−-transport properties by patch-clamp-, Ussing chamber- and isotopic efflux-measurements. Special attention was paid to a 32 pS outwardly rectifying Cl− channel which has been reported to be activated upon activation of cAMP-dependent pathways in N, but not in CF cells. This depolarization-induced Cl− channel was found with a similar incidence in N and CF apical keratininocyte membranes. However, activation of this channel in excised patches by protein kinase (PK)-A or PK-C was not successfull in either N or CF keratinocytes. Forskolin was not able to activate Cl− channels in N and CF cell-attached patches. The Ca2+-ionophore A23187 activated in cell-attached patches a linear 17 pS Cl− channel in both N and CF cells. This channel inactivated upon excision. No relationship between the cell-attached 17 pS and the excised 32 pS channel could be demonstrated. Returning to the measurement of Cl− transport at the macroscopic level, we found that a drastic rise in intracellular cAMP induced by forskolin did in N as well as CF cells not result in a change in the short-circuit current (Isc) or the fractional efflux rates of 36Cl− and 125I−. In contrast, addition of A23187 resulted in an increase of the Isc and in the isotopic anion efflux rates in N and CF cells. We conclude that Cl−-transport in cultured human keratinocytes can be activated by Ca2+, but not by cAMP-dependent pathways

Occupational exposure to gases/fumes and mineral dust affect DNA methylation levels of genes regulating expression

Many workers are daily exposed to occupational agents like gases/fumes, mineral dust or biological dust, which could induce adverse health effects. Epigenetic mechanisms, such as DNA methylation, have been suggested to play a role. We therefore aimed to identify differentially methylated regions (DMRs) upon occupational exposures in never-smokers and investigated if these DMRs associated with gene expression levels. To determine the effects of occupational exposures independent of smoking, 903 never-smokers of the LifeLines cohort study were included. We performed three genome-wide methylation analyses (Illumina 450 K), one per occupational exposure being gases/fumes, mineral dust and biological dust, using robust linear regression adjusted for appropriate confounders. DMRs were identified using comb-p in Python. Results were validated in the Rotterdam Study (233 never-smokers) and methylation-expression associations were assessed using Biobank-based Integrative Omics Study data (n = 2802). Of the total 21 significant DMRs, 14 DMRs were associated with gases/fumes and 7 with mineral dust. Three of these DMRs were associated with both exposures (RPLP1 and LINC02169 (2x)) and 11 DMRs were located within transcript start sites of gene expression regulating genes. We replicated two DMRs with gases/fumes (VTRNA2-1 and GNAS) and one with mineral dust (CCDC144NL). In addition, nine gases/fumes DMRs and six mineral dust DMRs significantly associated with gene expression levels. Our data suggest that occupational exposures may induce differential methylation of gene expression regulating genes and thereby may induce adverse health effects. Given the millions of workers that are exposed daily to occupational exposures, further studies on this epigenetic mechanism and health outcomes are warranted

Kinesiophobia in patients with non-traumatic arm, neck and shoulder complaints: a prospective cohort study in general practice

BACKGROUND: Complaints of arm, neck and shoulder are common in Western societies. Of those consulting a general practitioner (GP) with non-traumatic arm, neck or shoulder complaints, about 50% do not recover within 6 months.Kinesiophobia (also known as fear of movement/(re)injury) may also play a role in these complaints, as it may lead to avoidance behaviour resulting in hypervigilance to bodily sensations, followed by disability, disuse and depression. However, in relation to arm, neck and shoulder complaints little is known about kinesiophobia and its associated variables.Therefore this study aimed to: describe the degree of kinesiophobia in patients with non-traumatic complaints of arm, neck and shoulder in general practice; to determine whether mean scores of kinesiophobia change over time in non-recovered patients; and to evaluate variables associated with kinesiophobia at baseline. METHODS: In this prospective cohort study set in general practice, consulters with a first or new episode of non-traumatic arm, neck or shoulder complaints (aged 18-64 years) entered the cohort. Baseline data were collected on kinesiophobia using the Tampa Scale for Kinesiophobia, the 13-item adjusted version: TSK-AV, and on patient-, complaint-, and psychosocial variables using self-administered questionnaires. The mean TSK-AV score was calculated. In non-recovered patients the follow-up TSK-AV scores at 6 and 12 months were analyzed with the general linear mixed model. Variables associated with kinesiophobia at baseline were evaluated using multivariate linear regression analyses. RESULTS: The mean TSK-AV score at baseline was 24.8 [SD: 6.2]. Among non-recovered patients the mean TSK-AV score at baseline was 26.1 [SD: 6.6], which remained unchanged over 12- months follow-up period. The strongest associations with kinesiophobia were catastrophizing, disability, and comorbidity of musculoskeletal complaints. Additionally, having a shoulder complaint, low social support, high somatization and high distress contributed to the kinesiophobia score. CONCLUSION: The mean TSK-AV score in our population seems comparable to those in other populations in primary care.In patients who did not recover during the 12- month follow-up, the degree of kinesiophobia remained unchanged during this time period.The variables associated with kinesiophobia at baseline appear to be in line with the fear-avoidance model