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Polygenic risk, familial liability and stress reactivity in psychosis: an experience sampling study
- Anita Schick, Ruud van Winkel, Bochao D. Lin, Jurjen J. Luykx, Sonja M.C. de Zwarte, Kristel R. van Eijk, GROUP Investigators, Inez Myin-Germeys, Ulrich Reininghaus
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- Journal:
- Psychological Medicine / Volume 53 / Issue 7 / May 2023
- Published online by Cambridge University Press:
- 07 January 2022, pp. 2798-2807
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Background
There is evidence for a polygenic contribution to psychosis. One targetable mechanism through which polygenic variation may impact on individuals and interact with the social environment is stress sensitization, characterized by elevated reactivity to minor stressors in daily life. The current study aimed to investigate whether stress reactivity is modified by polygenic risk score for schizophrenia (PRS) in cases with enduring non-affective psychotic disorder, first-degree relatives of cases, and controls.
MethodsWe used the experience sampling method to assess minor stressors, negative affect, positive affect and psychotic experiences in 96 cases, 79 first-degree relatives, i.e. siblings, and 73 controls at wave 3 of the Dutch Genetic Risk and Outcome of Psychosis (GROUP) study. Genome-wide data were collected at baseline to calculate PRS.
ResultsWe found that associations of momentary stress with psychotic experiences, but not with negative and positive affect, were modified by PRS and group (all pFWE<0.001). In contrast to our hypotheses, siblings with high PRS reported less intense psychotic experiences in response to momentary stress compared to siblings with low PRS. No differences in magnitude of these associations were observed in cases with high v. low level of PRS. By contrast, controls with high PRS showed more intense psychotic experiences in response to stress compared to those with low PRS.
ConclusionsThis tentatively suggests that polygenic risk may operate in different ways than previously assumed and amplify reactivity to stress in unaffected individuals but operate as a resilience factor in relatives by attenuating their stress reactivity.
Prefrontal cortical thinning links to negative symptoms in schizophrenia via the ENIGMA consortium
- E. Walton, D. P. Hibar, T. G. M. van Erp, S. G. Potkin, R. Roiz-Santiañez, B. Crespo-Facorro, P. Suarez-Pinilla, N. E. M. van Haren, S. M. C. de Zwarte, R. S. Kahn, W. Cahn, N. T. Doan, K. N. Jørgensen, T. P. Gurholt, I. Agartz, O. A. Andreassen, L. T. Westlye, I. Melle, A. O. Berg, L. Morch-Johnsen, A. Færden, L. Flyckt, H. Fatouros-Bergman, Karolinska Schizophrenia Project Consortium (KaSP), E. G. Jönsson, R. Hashimoto, H. Yamamori, M. Fukunaga, N. Jahanshad, P. De Rossi, F. Piras, N. Banaj, G. Spalletta, R. E. Gur, R. C. Gur, D. H. Wolf, T. D. Satterthwaite, L. M. Beard, I. E. Sommer, S. Koops, O. Gruber, A. Richter, B. Krämer, S. Kelly, G. Donohoe, C. McDonald, D. M. Cannon, A. Corvin, M. Gill, A. Di Giorgio, A. Bertolino, S. Lawrie, T. Nickson, H. C. Whalley, E. Neilson, V. D. Calhoun, P. M. Thompson, J. A. Turner, S. Ehrlich
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- Journal:
- Psychological Medicine / Volume 48 / Issue 1 / January 2018
- Published online by Cambridge University Press:
- 26 May 2017, pp. 82-94
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Background
Our understanding of the complex relationship between schizophrenia symptomatology and etiological factors can be improved by studying brain-based correlates of schizophrenia. Research showed that impairments in value processing and executive functioning, which have been associated with prefrontal brain areas [particularly the medial orbitofrontal cortex (MOFC)], are linked to negative symptoms. Here we tested the hypothesis that MOFC thickness is associated with negative symptom severity.
MethodsThis study included 1985 individuals with schizophrenia from 17 research groups around the world contributing to the ENIGMA Schizophrenia Working Group. Cortical thickness values were obtained from T1-weighted structural brain scans using FreeSurfer. A meta-analysis across sites was conducted over effect sizes from a model predicting cortical thickness by negative symptom score (harmonized Scale for the Assessment of Negative Symptoms or Positive and Negative Syndrome Scale scores).
ResultsMeta-analytical results showed that left, but not right, MOFC thickness was significantly associated with negative symptom severity (βstd = −0.075; p = 0.019) after accounting for age, gender, and site. This effect remained significant (p = 0.036) in a model including overall illness severity. Covarying for duration of illness, age of onset, antipsychotic medication or handedness weakened the association of negative symptoms with left MOFC thickness. As part of a secondary analysis including 10 other prefrontal regions further associations in the left lateral orbitofrontal gyrus and pars opercularis emerged.
ConclusionsUsing an unusually large cohort and a meta-analytical approach, our findings point towards a link between prefrontal thinning and negative symptom severity in schizophrenia. This finding provides further insight into the relationship between structural brain abnormalities and negative symptoms in schizophrenia.
Chapter 31 - Sepsis
- from Section 4 - The pregnant patient with coexisting disease
- Edited by Marc van de Velde, Helen Scholefield, Lauren A. Plante
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- Maternal Critical Care
- Published online:
- 05 July 2013
- Print publication:
- 04 July 2013, pp 346-355
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Summary
Intensivists, physicians specially trained in critical care medicine, and other members of the ICU care team may have in-depth knowledge of monitors not available to the practitioner, who does not use them on a daily basis. The most commonly encountered non-invasive monitors are electrocardiography (ECG), pulse oximetry, blood pressure measurement by manometry, urine output, pulse oximetry and end-tidal carbon dioxide monitoring. Central venous pressure (CVP) is measured by placing a catheter into or near the right atrium or vena cava. Central venous pressure can be measured via a small microcatheter inserted into the frontal white matter. The physiological basis for intracranial pressure (ICP) monitoring is based on two separate but related mechanisms that contribute to cerebral ischemia. Fetal monitoring, in practice, is generally limited to the generation and interpretation of fetal heart rate patterns obtained through Doppler ultrasound.
Contributors
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- By Victoria M. Allen, Frederic Amant, Sarah Armstrong, Thomas F. Baskett, Michael A. Belfort, Meredith Birsner, Renee D. Boss, Leanne Bricker, Josaphat K. Byamugisha, Giorgio Capogna, Michael P. Casaer, Frank A. Chervenak, Vicki Clark, Filip Claus, Malachy O. Columb, Charles Cox, Jean T. Cox, Vegard Dahl, John Davison, Jan Deprest, Clifford S. Deutschman, Roland Devlieger, Karim Djekidel, Steven Dymarkowski, Roshan Fernando, Clare Fitzpatrick, Sreedhar Gaddipati, Thierry Girard, Emily Gordon, Ian A. Greer, David Grooms, Sina Haeri, Katy Harrison, Edward J. Hayes, Michelle Hladunewich, Andra H. James, Tracey Johnston, Bellal Joseph, Erin Keely, Ruth Landau, Stephen E. Lapinsky, Susanna I. Lee, Larry Leeman, Hennie Lombaard, Stephen Lu, Alison MacArthur, Laura A. Magee, Paul E. Marik, Laurence B. McCullough, Alexandre Mignon, Carlo Missant, Jack Moodley, Lisa E. Moore, Kate Morse, Warwick D. Ngan Kee, Catherine Nelson-Piercy, Clemens M. Ortner, Geraldine O’Sullivan, Luis D. Pacheco, Fathima Paruk, Melina Pectasides, Nigel Pereira, Patricia Peticca, Sharon T. Phelan, Felicity Plaat, Lauren A. Plante, Michael P. Plevyak, Dianne Plews, Wendy Pollock, Laura C. Price, Peter Rhee, Leiv Arne Rosseland, Kathryn M. Rowan, Helen Ryan, Helen Scholefield, Neil S. Seligman, Nadir Sharawi, Alex Sia, Bob Silver, Mieke Soens, Ulrich J. Spreng, Silvia Stirparo, Nova Szoka, Andrew Tang, Kha M. Tran, Els Troost, Lawrence C. Tsen, Derek Tuffnell, Kristel Van Calsteren, Marc Van de Velde, Marcel Vercauteren, Chris Verslype, Peter von Dadelszen, Carl Waldman, Michelle Walters, Linda Watkins, Paul Westhead, Cynthia A. Wong, Gerda G. Zeeman, Joost J. Zwart
- Edited by Marc van de Velde, Helen Scholefield, Lauren A. Plante
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- Book:
- Maternal Critical Care
- Published online:
- 05 July 2013
- Print publication:
- 04 July 2013, pp ix-xiv
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Intake rates and the functional response in shorebirds (Charadriiformes) eating macro-invertebrates
- John D. Goss-Custard, Andrew D. West, Michael G. Yates, Richard W. G. Caldow, Richard A. Stillman, Louise Bardsley, Juan Castilla, Macarena Castro, Volker Dierschke, Sarah. E. A. Le. V. dit Durell, Goetz Eichhorn, Bruno J. Ens, Klaus-Michael Exo, P. U. Udayangani-Fernando, Peter N. Ferns, Philip A. R. Hockey, Jennifer A. Gill, Ian Johnstone, Bozena Kalejta-Summers, Jose A. Masero, Francisco Moreira, Rajarathina Velu Nagarajan, Ian P. F. Owens, Cristian Pacheco, Alejandro Perez-Hurtado, Danny Rogers, Gregor Scheiffarth, Humphrey Sitters, William J. Sutherland, Patrick Triplet, Dave H. Worrall1, Yuri Zharikov, Leo Zwarts, Richard A. Pettifor
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- Journal:
- Biological Reviews / Volume 81 / Issue 4 / November 2006
- Published online by Cambridge University Press:
- 24 July 2006, pp. 501-529
- Print publication:
- November 2006
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As field determinations take much effort, it would be useful to be able to predict easily the coefficients describing the functional response of free-living predators, the function relating food intake rate to the abundance of food organisms in the environment. As a means easily to parameterise an individual-based model of shorebird Charadriiformes populations, we attempted this for shorebirds eating macro-invertebrates. Intake rate is measured as the ash-free dry mass (AFDM) per second of active foraging; i.e. excluding time spent on digestive pauses and other activities, such as preening. The present and previous studies show that the general shape of the functional response in shorebirds eating approximately the same size of prey across the full range of prey density is a decelerating rise to a plateau, thus approximating the Holling type II (‘disc equation’) formulation. But field studies confirmed that the asymptote was not set by handling time, as assumed by the disc equation, because only about half the foraging time was spent in successfully or unsuccessfully attacking and handling prey, the rest being devoted to searching.
A review of 30 functional responses showed that intake rate in free-living shorebirds varied independently of prey density over a wide range, with the asymptote being reached at very low prey densities (<150/m−2). Accordingly, most of the many studies of shorebird intake rate have probably been conducted at or near the asymptote of the functional response, suggesting that equations that predict intake rate should also predict the asymptote.
A multivariate analysis of 468 ‘spot’ estimates of intake rates from 26 shorebirds identified ten variables, representing prey and shorebird characteristics, that accounted for 81% of the variance in logarithm-transformed intake rate. But four-variables accounted for almost as much (77.3%), these being bird size, prey size, whether the bird was an oystercatcher Haematopus ostralegus eating mussels Mytilus edulis, or breeding. The four variable equation under-predicted, on average, the observed 30 estimates of the asymptote by 11.6%, but this discrepancy was reduced to 0.2% when two suspect estimates from one early study in the 1960s were removed. The equation therefore predicted the observed asymptote very successfully in 93% of cases.
We conclude that the asymptote can be reliably predicted from just four easily measured variables. Indeed, if the birds are not breeding and are not oystercatchers eating mussels, reliable predictions can be obtained using just two variables, bird and prey sizes. A multivariate analysis of 23 estimates of the half-asymptote constant suggested they were smaller when prey were small but greater when the birds were large, especially in oystercatchers. The resulting equation could be used to predict the half-asymptote constant, but its predictive power has yet to be tested.
As well as predicting the asymptote of the functional response, the equations will enable research workers engaged in many areas of shorebird ecology and behaviour to estimate intake rate without the need for conventional time-consuming field studies, including species for which it has not yet proved possible to measure intake rate in the field.
Long distance nitrogen air pollution effects on lichens in Europe
- C. M. van Herk, E. A. M. Mathijssen-Spiekman, D. de Zwart
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- Journal:
- The Lichenologist / Volume 35 / Issue 4 / July 2003
- Published online by Cambridge University Press:
- 28 March 2007, pp. 347-359
- Print publication:
- July 2003
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The epiphytic lichen flora of 25 European ICP-IM monitoring sites, all situated remote from air pollution sources, was statistically related to measured levels of SO2 in air, NH4+, NO3− and SO42− in precipitation, annual bulk precipitation, and annual average temperature. Significant regression models were calculated for eleven acidophytic species. Several species strong negative correlation with nitrogen compounds. At concentrations as low as 0·3 mg N l−1 in precipitation, a decrease of the probability of occurrence is observed for Bryoria capillaris, B. fuscescens, Cetraria pinastri, Imshaugia aleurites and Usnea hirta. The observed pattern correlations strongly suggests a key role of NH4+ in determining the species occurrence, additional role of NO3− cannot be ruled out. Some species show a distinct response to current of SO2 well. It may be concluded that long distance nitrogen air pollution has strong influence the occurrence of acidophytic lichen species.
The effect of previous growth retardation on energy and nitrogen metabolism of goats infected with Trypanosoma vivax
- J. T. P. Van Dam, J. W. Schrama, A. Vreden, M. W. A. Verstegen, T. Wensing, D. Van Der Heide, D. Zwart
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- Journal:
- British Journal of Nutrition / Volume 77 / Issue 3 / March 1997
- Published online by Cambridge University Press:
- 09 March 2007, pp. 427-441
- Print publication:
- March 1997
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The effect of growth retardation, resulting from feed restriction for a prolonged period, on the course of infection with Trypanosoma vivax was studied. Twelve male castrated West Africa Dwarf goats were subjected to a restricted feeding reghen of 55 g pelleted lucerne (Medicago safiva)/kg body weight0·75 per d for on average 17 weeks. Twelve other animals were fed on pelleted lucerne ad libitum, resulting in a normal growth pattern. After this period, all animals were fed on pelleted lucerne ad libitum, and six animatn of each previous feeding regimen treatment were infected with Trypanosoma viva. The other animals served as controls. In week 2 and 4 post infection (pi) energy and N balaoces were measured. In the week before infection and daring infection blood biochemical and clinlcal variables were measured. At 2 weeks before, and 4 weeks after infection, a liver biopsy was taken for measurement of triacylglycerol. Iofection caused intermittent fever and anaemia. The first peak of fever persisted longer in iofected anlmaln with normal growth than in infected animals with retarded growth. Gross energy and metabolizable energy intake, and energy retention were reduced ininfected animals. Metabolizable energy requirements for mainteoaoce were increased by infection. Plasma non-esterified fatty acids (NEFA) and glucose concentratioos were increased in infected animals, whereas serum triiodothyronine and thyroxine coocentratioos were decreased.Plasma urea concentration and liver triacylglycerol were uoaffected. No interaction of growth retardation with infection with respect to blood biochemical variables was found, apart from plasma NEFA in week 2 pi. N retention was not significantly affected by treatments. In conclusion, minor indications were found for an interaction between growth retardation, as applied in the present study, and trypaommiasis infection in West Africao Dwarf goats with respect to energy and N metabolism.
The effect of Trypanosoma vivax infection on energy and nitrogen metabolism and serum metabolites and hormones in West African Dwarf goats on different food intake levels
- J. T. P. van Dam, D. van der Heide, W. van der Hel, T. S. G. A. M. van den Ingh, M. W. A. Verstegen, T. Wensing, D. Zwart
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- Journal:
- Animal Science / Volume 63 / Issue 1 / August 1996
- Published online by Cambridge University Press:
- 02 September 2010, pp. 111-121
- Print publication:
- August 1996
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Effects of Trypanosoma vivax infection on nitrogen and energy metabolism and serum hormones and metabolites were measured using 24 castrated West African Dwarf bucks. In order to discriminate between the effect of infection and the effect of food intake level on energy and nitrogen balance, food quantity restriction was applied for isonutritional comparison; a number of the animals were not infected and served as controls. Daily dry-matter (DM) intake was measured, and energy and nitrogen balance for a 7-day period in weeks 2, 4 and 6 after infection. Weekly blood sampling for analysis of hormones and metabolites was carried out.
Infected animals had a lower DM intake, compared with control animals, viz. 38·6 (s.e. 3·2) and 16·1 (s.e. 2·0) g/kg M0·75 per day, respectively (P < 0·001). Intake of gross energy and nitrogen followed the same pattern.
Metabolizability was not changed by infection and averaged 0·44. Heat production was increased by infection with an average of 33 kJ/kg M0·75 per day. Energy and nitrogen retention were negative for all groups; infection reduced energy retention and, during week 2 and 4 after infection, also nitrogen retention. The required metabolizable energy (ME) intake for maintenance was increased in infected animals (406 and 335 kJ/kg M0·75 per day for infected and control goats respectively), based on linear regression of energy retention on ME intake. The efficiency with which energy mobilization from body stores was substituted by dietary ME was estimated at 0·809 for both infected and control animals. The relationship between nitrogen retention and energy retention was not changed by infection. Therefore no indications were found for an increased catabolism of protein due to infection. Serum thyroxine and triiodothyronine were reduced by infection; serum metabolites and insulin levels reflected the negative energy balance in infected animals.