Long-term cardiac assessment in a sample of adolescent-onset anorexia nervosa.

BACKGROUND: High mortality rates have been reported in patients with anorexia nervosa, mainly due to cardiovascular alterations. The purpose of the present study was to assess cardiac structural and functional abnormalities some 20 years after initial treatment in a sample of adolescent-onset anorexia nervosa (A-AN) and to compare them with matched healthy controls (HC). METHODS: A sample of 29 women diagnosed and treated for AN during adolescence (A-AN) were assessed more than 20 years later. A complete cardiac evaluation was carried out including an electrocardiogram (ECG) and a standard 2D echocardiography. Thirty matched HC were also assessed. RESULTS: In the A-AN group, four subjects had a body mass index lower than 18.5 and met full DSM 5 criteria for AN at follow-up (Low-Weight group). They were compared with the rest of the sample (n = 25) who had normalized their weight (Normal-Weight group), though some still showed some eating disorder symptoms. Both groups were compared with the HC group. Subjects in the Low-Weight group presented statistically significant decreases in the left ventricular end-diastolic and left atrium dimensions and left ventricular mass in comparison with the Normal-Weight group and the HC. No other differences in cardiac parameters were found between groups. CONCLUSIONS: Echocardiographic and ECG parameters of adults who had presented A-AN twenty years earlier and currently maintained normal weight were similar to those of HC who had never been treated or diagnosed with AN. Adult subjects with A-AN who still had low weight in the long term present certain cardiac abnormalities similar to those seen in short-lasting disease. More studies are needed to confirm these results in a larger sample.

Anorexia nervosa is associated with multiple medical complications and high mortality, mainly due to cardiovascular complications. The main objective of the project was to study long-term cardiac abnormalities in a group of patients diagnosed with anorexia nervosa during adolescence. A sample of 29 patients, treated during adolescence for anorexia nervosa, were evaluated 20 years later. We did an echocardiogram and an electrocardiogram to all of them, and compared them with 30 healthy controls. Of the 29 patients with anorexia nervosa, 4 had low weight and 25 had normal weight. Patients who had normalized their weight did not present cardiac alterations and did not differ from the healthy controls. The 4 underweight patients did present cardiac abnormalities similar to those observed in short-term studies, such as decreased dimensions and mass of the left ventricle and the left atrium.

Development and psychometric properties of the "Suicidality: Treatment Occurring in Paediatrics (STOP) Risk and Resilience Factors Scales" in adolescents.

Suicidality in the child and adolescent population is a major public health concern. There is, however, a lack of developmentally sensitive valid and reliable instruments that can capture data on risk, and clinical and psychosocial mediators of suicidality in young people. In this study, we aimed to develop and assess the validity of instruments evaluating the psychosocial risk and protective factors for suicidal behaviours in the adolescent population. In Phase 1, based on a systematic literature review of suicidality, focus groups, and expert panel advice, the risk factors and protective factors (resilience factors) were identified and the adolescent, parent, and clinician versions of the STOP-Suicidality Risk Factors Scale (STOP-SRiFS) and the Resilience Factors Scale (STOP-SReFS) were developed. Phase 2 involved instrument validation and comprised of two samples (Sample 1 and 2). Sample 1 consisted of 87 adolescents, their parents/carers, and clinicians from the various participating centres, and Sample 2 consisted of three sub-samples: adolescents (n = 259) who completed STOP-SRiFS and/or the STOP-SReFS scales, parents (n = 213) who completed one or both of the scales, and the clinicians who completed the scales (n = 254). The STOP-SRiFS demonstrated a good construct validity-the Cronbach Alpha for the adolescent (α = 0.864), parent (α = 0.842), and clinician (α = 0.722) versions of the scale. Test-retest reliability, inter-rater reliability, and content validity were good for all three versions of the STOP-SRiFS. The sub-scales generated using Exploratory Factor Analysis (EFA) were the (1) anxiety and depression risk, (2) substance misuse risk, (3) interpersonal risk, (4) chronic risk, and (5) risk due to life events. For the STOP-SRiFS, statistically significant correlations were found between the Columbia-Suicide Severity Rating Scale (C-SSRS) total score and the adolescent, parent, and clinical versions of the STOP-SRiFS sub-scale scores. The STOP-SRiFS showed good psychometric properties. This study demonstrated a good construct validity for the STOP-SReFS-the Cronbach Alpha for the three versions were good (adolescent: α = 0.775; parent: α = 0.808; α = clinician: 0.808). EFA for the adolescent version of the STOP-SReFS, which consists of 9 resilience factors domains, generated two factors (1) interpersonal resilience and (2) cognitive resilience. The STOP-SReFS Cognitive Resilience sub-scale for the adolescent was negatively correlated (r = - 0.275) with the C-SSRS total score, showing that there was lower suicidality in those with greater Cognitive Resilience. The STOP-SReFS Interpersonal resilience sub-scale correlations were all negative, but none of them were significantly different to the C-SSRS total scores for either the adolescent, parent, or clinician versions of the scales. This is not surprising, because the items in this sub-scale capture a much larger time-scale, compared to the C-SSRS rating period. The STOP-SReFS showed good psychometric properties. The STOP-SRiFS and STOP-SReFS are instruments that can be used in future studies about suicidality in children and adolescents.

Psychosocial risk factors for suicidality in children and adolescents.

Suicidality in childhood and adolescence is of increasing concern. The aim of this paper was to review the published literature identifying key psychosocial risk factors for suicidality in the paediatric population. A systematic two-step search was carried out following the PRISMA statement guidelines, using the terms 'suicidality, suicide, and self-harm' combined with terms 'infant, child, adolescent' according to the US National Library of Medicine and the National Institutes of Health classification of ages. Forty-four studies were included in the qualitative synthesis. The review identified three main factors that appear to increase the risk of suicidality: psychological factors (depression, anxiety, previous suicide attempt, drug and alcohol use, and other comorbid psychiatric disorders); stressful life events (family problems and peer conflicts); and personality traits (such as neuroticism and impulsivity). The evidence highlights the complexity of suicidality and points towards an interaction of factors contributing to suicidal behaviour. More information is needed to understand the complex relationship between risk factors for suicidality. Prospective studies with adequate sample sizes are needed to investigate these multiple variables of risk concurrently and over time.

Development and psychometric properties of the Suicidality: Treatment Occurring in Paediatrics (STOP) Suicidality Assessment Scale (STOP-SAS) in children and adolescents.

BACKGROUND: To create a self-reported, internet-based questionnaire for the assessment of suicide risk in children and adolescents. METHODS: As part of the EU project 'Suicidality: Treatment Occurring in Paediatrics' (STOP project), we developed web-based Patient Reported Outcome Measures (PROMs) for children and adolescents and for proxy reports by parents and clinicians in order to assess suicidality. Based on a literature review, expert panels and focus groups of patients, we developed the items of the STOP Suicidality Assessment Scale (STOP-SAS) in Spanish and English, translated it into four more languages, and optimized it for web-based presentation using the HealthTrackerTM platform. Of the total 19 questions developed for the STOP-SAS, four questions that assess low-level suicidality were identified as screening questions (three of them for use with children, and all four for use with adolescents, parents and clinicians). A total of 395 adolescents, 110 children, 637 parents and 716 clinicians completed the questionnaire using the HealthTrackerTM, allowing us to evaluate the internal consistency and convergent validity of the STOP-SAS with the clinician-rated Columbia Suicide Severity Rating Scale (C-SSRS). Validity was also assessed with the receiver operating characteristic (ROC) area of the STOP-SAS with the C-SSRS. RESULTS: The STOP-SAS comprises 19 items in its adolescent, parent, and clinician versions, and 14 items in its children's version. Good internal consistency was found for adolescents (Cronbach's alpha: 0.965), children (Cronbach's alpha: 0.922), parents (Cronbach's alpha: 0.951) and clinicians (Cronbach's alpha: 0.955) versions. A strong correlation was found between the STOP-SAS and the C-SSRS for adolescents (r:0.670), parents (r:0.548), clinicians (r:0.863) and children (r:0.654). The ROC area was good for clinicians' (0.917), adolescents' (0.834) and parents' (0.756) versions but only fair (0.683) for children's version. CONCLUSIONS: The STOP-SAS is a comprehensive, web-based PROM developed on the HealthTrackerTM platform, and co-designed for use by adolescents, children, parents and clinicians. It allows the evaluation of aspects of suicidality and shows good reliability and validity.

Variability in mitochondria of zebrafish photoreceptor ellipsoids.

Ultrastructural examination of photoreceptor inner segment ellipsoids in larval (4, 8, and 15 days postfertilization; dpf) and adult zebrafish identified morphologically different types of mitochondria. All photoreceptors had mitochondria of different sizes (large and small). At 4 dpf, rods had small, moderately stained electron-dense mitochondria (E-DM), and two cone types could be distinguished: (1) those with electron-lucent mitochondria (E-LM) and (2) those with mitochondria of moderate electron density. These distinctions were also apparent at later ages (8 and 15 dpf). Rods from adult fish had fewer mitochondria than their corresponding cones. The ellipsoids of some fully differentiated single and double cones contained large E-DM with few cristae; these were surrounded by small E-LM with typical internal morphology. The mitochondria within the ellipsoids of other single cones showed similar electron density. Microspectrophotometry of cone ellipsoids from adult fish indicated that the large E-DM had a small absorbance peak (∼0.03 OD units) and did not contain cytochrome-c, but crocetin, a carotenoid found in old world monkeys. Crocetin functions to prevent oxidative damage to photoreceptors, suggesting that the ellipsoid mitochondria in adult zebrafish cones protect against apoptosis and function metabolically, rather than as a light filter.

Communication using eye roll reflective signalling.

Body reflections in the ultraviolet (UV) are a common occurrence in nature. Despite the abundance of such signals and the presence of UV cones in the retinas of many vertebrates, the function of UV cones in the majority of taxa remains unclear. Here, we report on an unusual communication system in the razorback sucker, Xyrauchen texanus, that involves flash signals produced by quick eye rolls. Behavioural experiments and field observations indicate that this form of communication is used to signal territorial presence between males. The flash signal shows highest contrast in the UV region of the visual spectrum (lambdamax approximately 380 nm), corresponding to the maximum wavelength of absorption of the UV cone mechanism in suckers. Furthermore, these cones are restricted to the dorsal retina of the animal and the upwelling light background is such that their relative sensitivity would be enhanced by chromatic adaptation of the other cone mechanisms. Thus, the UV cones in the sucker have optimal characteristics (both in terms of absorbance and retinal topography) to constitute the main detectors of the flash signal. Our findings provide the first ecological evidence for restricted distribution of UV cones in the retina of a vertebrate.

Gradual and partial loss of corner cone-occupied area in the retina of rainbow trout.

Several studies have indicated that the rainbow trout (Oncorhynchus mykiss) loses ultraviolet (UV) sensitivity and the associated UV-sensitive corner cones when the animal transforms from a small (parr) juvenile to a larger, silver-coloured, smolt. Similar changes supposedly take place when parr juveniles are treated with thyroid hormone (T(4)) or retinoic acid. In contrast to previous investigations, this study shows that parr juveniles lack corner cones throughout the lower half of the ventral retina, suggesting that corner cones cease to be incorporated into the ventral retina some time after hatching. This uneven incorporation of corner cones across the retina, when combined with retinal growth, creates a progressively smaller area of lower retina occupied by corner cones. Because in previous studies, the stimulating illumination was directed primarily at the ventral retina, the reported age-dependent changes in UV or polarization sensitivities can be explained by differences in the area of corner cones that was illuminated, and not necessarily by a loss of corner cones. This study also shows: (1) that the double cones from non-ventral mosaics of parr rainbow trout may change in cross-sectional shape, altering the mosaic formation from a square to a row, (2) the existence of a 'pure' (non-changing) square mosaic in the ventral retina, and (3) a potential method, based on differential staining of cone nuclei, to classify paired cones into double or twin cones.

Foraging and prey-search behaviour of small juvenile rainbow trout (Oncorhynchus mykiss) under polarized light.

Several fish species appear to be polarization sensitive, i.e. to be able to discriminate a light source's maximum plane of polarization from any other plane. However, the functional significance of this ability remains unclear. We tested the hypothesis that polarized light improves the prey location ability of free-swimming rainbow trout (Oncorhynchus mykiss) in laboratory aquaria. We found that prey location distances increased while the vertical component of prey location angle decreased under polarized compared with unpolarized (diffuse) illumination. The average frequency distribution of the horizontal component of prey location angle was more bimodal under polarized than unpolarized illumination. These results indicate that polarization sensitivity enhances prey location by juvenile rainbow trout.

Expression of pineal ultraviolet- and green-like opsins in the pineal organ and retina of teleosts.

In teleostean bony fishes, studies on the adults of various species have shown that pineal photoreceptors are maximally sensitive to short- and middle-wavelength light, possibly utilising both rod-like and pineal-specific opsins. Until recently, however, very little was known about the pineal opsins present in embryonic and larval teleosts and their relationships to opsins expressed by retinal photoreceptors. Our immunocytochemical studies have revealed that, in Atlantic halibut, herring and cod, pineal photoreceptors express principal phototransduction molecules during embryonic life before they appear in retinal photoreceptors. In cDNA from embryonic and adult halibut, we identified two partial opsin gene sequences, HPO1 and HPO4, with highest homology to teleost green and ultraviolet cone opsins (72-83% and 71-83% amino acid identity, respectively). In halibut, these opsins are expressed in the pineal organ of embryos and appear in the retina of larvae. Our recent in situ hybridisation studies with RNA probes for HPO1 and HPO4 demonstrate the presence of green-like opsin mRNAs in the pineal organ and the retina of herring, cod, turbot, haddock, Atlantic salmon, zebrafish and three species of cichlid, and of ultraviolet opsins in the retinas of zebrafish, Atlantic salmon, turbot and the three cichlid species. We conclude that the halibut pineal organ appears to have the potential for both ultraviolet and green photosensitivity from the embryonic stage and that the retina may acquire the same potential during the larval stages. In the other teleosts studied, although both pineal and retinal photoreceptors seem to utilise a green-like opsin from the larval stage, ultraviolet photoreception appears to be restricted to the retina.

Photoreceptors, visual pigments, and ellipsosomes in the killifish, Fundulus heteroclitus: a microspectrophotometric and histological study.

The photoreceptor layer of F. heteroclitus was examined by light and electron microscopy. We identified four cone visual pigments with maximum absorbance (lambda(max)) in the UV (363 nm), short (400 nm), middle (463 nm), and long (563 nm) wavelength regions of the spectrum and a rod visual pigment that peaked in the middle wavelengths (503 nm). Electron-dense bodies, ellipsosomes and pseudoellipsosomes, were present in the distal ellipsoids of long/middle (L/M) and long/long (L/L) wavelength double cones and in single short wavelength (S) cones, respectively. The light absorption of ellipsosomes indicated the presence of reduced cytochrome-c with the highest optical densities found in the M members of L/M double cones. By contrast, S cones contained pseudo-ellipsosomes which had very low optical density. UV cones were present everywhere as part of square or row mosaics in the retina of F. heteroclitus. Cone packing was on average higher for locations in the upper half of the retina while the highest cone density was found in the centro-ventral retina. An analysis of potential quantum catches for each cone type as a function of retinal sector and underwater irradiance characteristics revealed higher overall quantum catches for cones in the upper retina when the light field was assumed homogeneous, and higher quantum catches for cones in the lower retina when downwelling, horizontal, and upwelling irradiances were considered separately. At dusk, quantum catch was highest for M cones and the contribution to the overall retinal quantum catch by UV and S cones was much greater than during daylight hours. We propose that UV and S cones may be used to detect targets of interest against the background irradiance sensed by double cones.

Ontogenetic changes in visual sensitivity of the parasitic salmon louse Lepeophtheirus salmonis.

The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic copepod of salmonid fishes whose life cycle involves two broadly defined, free-living larval stages, the nauplius and the copepodid. After settling on a host, the copepodid goes through various transformations to become a mobile adult. We recorded swimming responses of free-swimming salmon lice at the naupliar, copepodid and adult stages to the onset (ON) and offset (OFF) of lights of varying spectral irradiance and polarization. Nauplii showed a prominent swim-up OFF response across the spectrum 352-652 nm, but no ON response. Copepodids exhibited a swim-up ON response and a passive (sinking) OFF response across the same spectral range. Adults showed active swim-up responses to both ON and OFF stimuli, although the OFF response was proportionately stronger. The spectral range of the adult ON and OFF responses was the same as that of the copepodids and slightly greater than that of the nauplii, which did not exhibit responses at 652 nm. The absolute sensitivity of copepodids under white light (approx. 10(-13) photons m(2) s(1)) was higher than that of nauplii (approx. 10(-17) photons(-1) m(2 )s, OFF response) and that of adult female lice (approx. 10(-14) photons(-1)m(2)s). This suggests that the naupliar visual system is best suited for detection of shadows (e.g. the host) under a bright light field (daylight hours), while copepodids and adults may be more specialized for host detection at crepuscular periods and during the night, when light levels are low. None of the developmental stages responded to the rotation of the plane of polarized light or exhibited any difference in directed response when polarized light was used in place of diffuse light.

The ontogeny of ultraviolet sensitivity, cone disappearance and regeneration in the sockeye salmon Oncorhynchus nerka.

This study examines the spectral sensitivity and cone topography of the sockeye salmon Oncorhynchus nerka throughout its life history with special emphasis on ultraviolet sensitivity. Electrophysiological recordings from the optic nerve show that ultraviolet sensitivity is greatly diminished at the smolt stage but reappears in adult fish weighing about 201 g. Concomitantly, light microscopy observations of the retina show that ultraviolet cones disappear from the dorsal and temporal retina at the smolt stage but reappear at the adult stage. These changes occur for sockeye salmon raised in fresh water or salt water after smoltification. In contrast to this ultraviolet cycle, the other cone mechanisms (short-, middle- and long-wavelength-sensitive) and the rod mechanism remain present throughout ontogeny. The natural appearance and disappearance of ultraviolet cones in salmonid retinas follows surges in blood thyroxine at critical developmental periods. Their presence coincides with times of prominent feeding on zooplankton and/or small fish that may be more visible under ultraviolet light. It is proposed that the primary function of ultraviolet cones in salmonids is to improve prey contrast.

Wavelength-dependent polarization orientation in Daphnia.

The ability to detect and use the polarization of light for orientation is widespread among invertebrates. Among terrestrial insects, the retinula cells that are responsible for polarization detection contain a single visual pigment, either ultraviolet or short (blue) wavelength sensitive. With the exception of a few aquatic insects, the visual pigments underlying polarization sensitivity in aquatic invertebrates have yet to be determined. Here we report that polarotaxis in Daphnia pulex, a freshwater crustacean, is wavelength dependent and most likely mediated by two visual pigments with absorbance maxima in the middle (green) and long wavelength (red) parts of the spectrum. This contrasts with the response of a closely related species, D. magna, in which polarotaxis is wavelength independent and based on a single middle wavelength visual pigment. The visual systems in Daphnia are the first among crustaceans shown to utilize a middle wavelength pigment for polarization detection and, in the case of D. pulex, the first shown to use more than one visual pigment for such a purpose.

Double-cone internal reflection as a basis for polarization detection in fish.

Some species of fish are able to discriminate, in addition to intensity and wavelength (color), the direction of polarization of visible light. Optical experiments on axially oriented retinal cones from trout and sunfish with use of two types of polarization microscope indicate anisotropic light transmission through paired cones. The measured linear birefringence of paired cone ellipsoids is consistent with the presence of membranous partitions. It is proposed that the partition between the two members of a paired cone, which often appears extensive and flat, functions as a dielectric mirror and that polarization-dependent reflection and refraction at this partition constitutes the underlying mechanism in the transduction of polarization into intensity variation at the photoreceptor's outer segments. We support this hypothesis with linear birefringence and linear dichroism measurements, histological evidence, large-scale optical model measurements, and theoretical calculations based on Fresnel's formulas.

Cone photoreceptor topography in the retina of sexually mature Pacific salmonid fishes.

We examined the retinal cone topography in sexually mature individuals from four species of Pacific salmonid fishes by using semithin plastic sections. We identified variations in cone density and cone arrangements and noted the presence of putative ultraviolet (UV) cones. Putative UV cones were found over an area extending dorsotemporally from the center of the retina. Because most of the putative UV cones are believed to disappear in early ontogeny, their presence over a large proportion (15-20%) of the surface area of the adult retina suggests that they may be reincorporated prior to or at sexual maturity, at least in rainbow trout. Cone density varied across the retina, with highest values at the peripheral margin. Relatively high densities were observed ventrotemporally (in all specimens) and, to a lesser extent, dorsonasally (7 of 11 specimens). The higher cone density in the ventrotemporal retina may represent a retinal specialization in the part of the visual field located above and in front of the animal. Lowest cone densities were found dorsocentrally and coincided approximately with the distribution of putative UV cones, raising the possibility that these cones may not be used in visual tasks requiring the higher visual acuity normally associated with higher cone densities. We also report a novel cone arrangement that consists of rows of double cones inserted between rows composed of single-double cone pairs alternating in position.

No evidence of polarization sensitivity in freshwater sunfish from multi-unit optic nerve recordings.

The sensitivities of two species of sunfish (Lepomis gibbosus and Lepomis cyanellus) to the electric field (E-vector) of polarized light were assessed by compound action potential recordings from the optic nerve of live fish. Under white light and long wavelength adapting backgrounds, two cone mechanisms were found with maximum sensitivities in the long wavelength (lambda max approximately 620 nm) and middle wavelength (lambda max approximately 530 nm) regions of the spectrum. In contrast to previous findings (Cameron & Pugh, 1991), no evidence of polarization sensitivity was observed for either species. We conclude from these results that post-larval sunfish do not exhibit polarization sensitivity.

Is the use of underwater polarized light by fish restricted to crepuscular time periods?

We measured the spectral distributions of the underwater total and polarized light fields in the upper photic zone of meso-eutrophic waters (i.e., blue-green waters containing medium to high chlorophyll a concentrations). Per cent polarization levels during the day were always lower than 40%, but at crepuscular times these values could increase to 67%. A corresponding change occurred in the spectral distribution, with proportionately more shorter wavelength photons contributing to the total spectrum during crepuscular periods. Electrophysiological recordings from the optic nerve of rainbow trout subjected to light stimuli of varying polarization percentages show that the animal's threshold for detecting polarized light is between 63 and 72%. These physiological findings suggest that the use of water-induced polarized light cues by rainbow trout and similar percomorph fish should be restricted to crepuscular time periods.