Combining two model systems of psychosis: The effects of schizotypy and sleep deprivation on oculomotor control and psychotomimetic states

Model systems of psychosis, such as schizotypy or sleep deprivation, are valuable in informing our understanding of the etiology of the disorder and aiding the development of new treatments. Schizophrenia patients, high schizotypes, and sleep‐deprived subjects are known to share deficits in oculomotor biomarkers. Here, we aimed to further validate the schizotypy and sleep deprivation models and investigated, for the first time, their interactive effects on smooth pursuit eye movements (SPEM), prosaccades, antisaccades, predictive saccades, and measures of psychotomimetic states, anxiety, depression, and stress. To do so, n = 19 controls and n = 17 high positive schizotypes were examined after both a normal sleep night and 24 h of sleep deprivation. Schizotypes displayed higher SPEM global position error, catch‐up saccade amplitude, and increased psychotomimetic states. Sleep deprivation impaired SPEM, prosaccade, antisaccade, and predictive saccade performance and increased levels of psychotomimetic experiences. Additionally, sleep deprivation reduced SPEM gain in schizotypes but not controls. We conclude that oculomotor impairments are observed in relation to schizotypy and following sleep deprivation, supporting their utility as biomarkers in model systems of psychosis. The combination of these models with oculomotor biomarkers may be particularly fruitful in assisting the development of new antipsychotic or pro‐cognitive drugs.     

Cardiovascular responses after brisk finger movement and their dependency on the "eigenfrequency" of the baroreflex loop

The ‘thermal grill illusion’ refers to paradoxical sensations of heat and pain, resulting from simultaneous application of interlaced warm and cold stimuli to the skin. It provides an interesting model of integrative mechanisms in the nervous system, supposed to be relevant in explaining the hypersensitivity found in chronic pain of unclear etiology. The aim of this study is to investigate the perceptual qualities elicited by a reconstruction of the original grill stimulator and to compare these qualities with those elicited by a single temperature thermode of identical dimensions. Healthy participants performed these comparisons by choosing adjectives describing the perceived sensory qualities. We hypothesized that the thermal grill would be perceived as different from a single temperature hot stimulus near pain threshold because of varying sensory qualities. Moreover, the qualities elicited by the grill were expected to be different from the qualities elicited by its single component temperatures. The thermal grill elicited a complex percept, which was distinguished almost perfect from a hot stimulus. The pattern of perceived qualities of the thermal grill differed from single temperature warm and hot stimuli. Pain-related sensations were less present in the grill percept than in a single hot stimulus near pain threshold. The spectrum of qualities of the grill stimulus changed marginally with stimulus duration by decrease of a cold component and concurrent increase of a heat component. In conclusion, the percept of the thermal grill is not simply pain - it can be understood as a metaesthetic percept at the transition from heat to pain.     

Paul E. Meehl's influence on experimental psychopathology: fruits of the nexus of schizotypy and schizophrenia, neurology, and methodology

Paul E. Meehl made numerous contributions to clinical science and a hallmark of many of these contributions was their integrative nature. Meehl's positions on complex topics, especially one such as schizophrenia, were reflective of input from a variety of disciplines and levels of analysis. In this essay the authors focus on Meehl's uniquely rich contribution to our understanding of schizophrenia through his theoretical model of schizotypy, his abiding interest in exploring neurologically based indicators of schizophrenia liability and encouragement to others to pursue such indicators, and his passion for rigorous research methodology. Meehl's contributions in each of these areas continue to influence the direction and research strategies used in experimental psychopathology to illuminate the fundamental nature of schizophrenia. These contributions have also shaped inquiry into many other psychopathological entities.     

The influence of attachment representation on parental perception and interpretation of infant emotions: A multilevel approach

The aim of the study was to investigate parental perception and interpretation of infant emotional expression depending on their attachment representation. Forty‐six parents' responses to infant pictures depicting positive, neutral, and negative emotions were assessed on the level of affective judgments (valence, arousal), mimic responses (facial muscle activity), and of the eyelid reflex (using the startle paradigm). Results revealed small differences between parents of different attachment representations with respect to their subjective evaluations. However, secure parents, as compared to insecure ones, showed a positive bias in their mimic responses to infant pictures. The modulation of the startle response indicated a negative evaluation of negative infant emotion expressions in dismissing parents, while an augmentation of the startle response to negative infant emotions could not be observed in secure and preoccupied parents. The findings highlight the role of attachment experiences for emotional information processing in parents and its consequences for parental behavior. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 411–423, 2010.     

Corticofugal influence on evoked activity of lateral geniculate neurons in the rabbit

Summary Corticofugal influence upon lateral geniculate units was eveluated by inactivating the visual cortex with a topical application of 3 M KCL in rabbits. The results revealed a decrease of spontaneous firing in slow P cells following cortical depression suggesting a tonic corticofugal influence. The most consistently observed alteration was an enhancement of the ON response with a decrease of the response to the opposite stimulus (OFF); and vice versa: the short latency excitation being augmented. It is suggested that the visual cortex exerts a powerful influence on intra-geniculate inhibitory processes.Supported by N.R.C.C. No. A6943     

Sham feeding as a procedure for assessing the influence of diet palatability on food intake

Most of the methods used to evaluate the role of taste factors on food intake are confounded by the postingestional consequences of the ingested diet which interfere with measurements of consumption based strictly upon the stimulus properties of the food. The present experiment examines the utility of sham feeding in the gastric fistulated rat as a means of isolating, and thereby evaluating, the contribution of hedonically positive (sweet) and hedonically negative (bitter) taste factors on the magnitude of food intake. Rats equipped with open gastric cannulae sham fed solutions varying in their sucrose or quinine concentrations. The results revealed that the magnitude of sham feeding in a fixed time period varied systematically with the taste properties of the food. It is concluded that sham feeding represents a useful technique for isolating the influence of diet palatability on food intake. Furthermore, the present data identify one of the parameters that influences the magnitude of the sham feeding response, information that is important for studies using this preparation as a means of examining oral sensory controls of food intake control systems.     

The influence of the atrial myocardium on impulse formation in the rabbit sinus node

In the isolated right atrium of the rabbit heart the influence of the atrial myocardium on impulse formation in the sinus node was investigated. Under normal conditions the pacemaker (earliest activation) was located in the center of the node where fibers with the highest rate of diastolic depolarization were found. After disconnection of the atrium from the sinus node spontaneous cycle length decreased from a mean of 348 ms to a mean of 288 ms (–18%) in all experiments (n=15). This was accompanied by a shift of the pacemaker from the nodal center towards the border zone. By means of multiple microelectrode impalements changes in action potential configuration were studied. After disconnection of atrium and sinus node the rate of diastolic depolarization of fibers in the border zone was increased from a mean of 26 mV/s to a mean of 78 mV/s, whereas in the center of the sinus node no increase was found (mean: 52 mV/s). It was concluded that the fibers in the border zone of the sinus node are better pacemaker fibers than in the nodal center. However under normal conditions the intrinsic pacemaker properties of the border zone fibers are electronically depressed by the connected atrial myocardium.     

Transnatal olfactory continuity in the rabbit: behavioral evidence and short-term consequence of its disruption

This study investigates the role of prenatal odor learning on postnatal adaptive orientation responses in the newborn rabbit. Preference tests revealed that pups are equally attracted to the odors of placentae and colostrum (Experiments 1-4), suggesting that an odor continuity may exist between the fetal and neonatal environments. To test some predictions derived from this hypothesis, we manipulated the odor of the diet of pregnant-lactating does to control the chemical niches of their perinates. Fetuses exposed in this way to the odor of cumin (C) were selectively attracted as neonates to the odor of pure C (Experiment 6). Prenatal exposure to C also was followed, to a certain extent, by enhanced attraction to C odor in the placenta or colostrum from females which had consumed it (Experiments 5 & 7). Finally, the functional implications of perinatal odor continuity were tested by disrupting it. The odor component of the feto-neonatal transitional environment revealed indeed to affect the ability of certain pups to gain colostrum and milk at the very first sucking opportunities (Experiment 8).     

The influence of sympathetic nerve activity on axial position of the rabbit incisor tooth

Changes in position of the upper front tooth in response to sectioning and subsequent electrical stimulation of the cervical sympathetic nerves were studied in 25 anesthetized rabbits. The position was continuously recorded by an ultrasonic transit time technique. Sectioning of the nerves was found to induce an average tooth extrusion of about 7 μm. Sympathetic nerve stimulation for periods of 20–30 s caused intrusion of the tooth, with about 70% of maximum occurring at 2 Hz stimulations. The intrusive response was reduced by phentolamine. Neither atropine nor propranolol affected the stimulation response, but the latter drug led to marked extrusion of the tooth. In conclusion, the position of the rabbit's front tooth was found to be highly sensitive to alterations in sympathetic nerve activity to the vasculature of the tooth-supporting tissues.     

The influence of risk perception for COVID-19 pandemic on posttraumatic stress disorder in healthcare workers: A survey from four designated hospitals

The aim of current study was to investigate risk perception of COVID-19 pandemic, sleep quality and time change of leisure activity and their correlations with posttraumatic stress disorder (PTSD) in healthcare workers (HCWs) from four designated hospitals in China. Medical staffs (n = 317) from three designated hospitals in Guangdong Province and one designated hospital in Guangxi Province were surveyed on their demographic information, sleep quality and time change of leisure activity, risk perception of pandemic and PTSD symptoms (by using PTSD checklist for DSM-5 (PCL-5)). Hierarchical regression and structural equation model (SEM) were used to examine the correlated factors of PTSD. The prevalence of high level of PTSD symptoms (PCL-5 > =33, a probable diagnosis of PTSD) was 10.7%. Regression analysis found that risk perception (dread: β = 0.142, p < 0.01; familiarity: β = 0.203, p < 0.01), sleep quality (β = 0.250, p < 0.001), time change of leisure activity (β = −0.179, p < 0.01), were independently correlated with PTSD severity, which was further confirmed by SEM. Locations of COVID-19-related hazards were significant different in cognitive map of risk perception between groups with high and low levels of PTSD symptoms. Risk perception of COVID-19 pandemic influenced PTSD symptoms in HCWs. Adequate time for leisure activity and good sleep quality protected some HCWs against PTSD symptoms under the influence of pandemic. More researches were warranted to understand the path from pre-factors of risk perception to its psychological consequences among HCWs.     

Judging beforehand the possibility of passing under obstacles without motion: the influence of egocentric and geocentric frames of reference

Previous studies have shown that the perception of the earth-based visual horizon, also named Gravity Referenced Eye Level (GREL), is modified by body tilt around a trans-ocular axis. Here, we investigated whether estimates of the elevation of a luminous horizontal line presented on a screen in otherwise darkness and estimates of the possibility of passing under are identically related to body tilt in absence of motion. Results showed that subjects overestimated the elevation of the projected line, whatever their body orientation. In the same way, subjects also overestimated their capacity of passing under the line. Both estimates appeared as a linear function of body tilt, that is, forward body tilt yielded increased overestimations, and backward body tilt yielded decreased overestimations. More strikingly, the linear effect of body tilt upon these estimates is comparable to that previously observed for direct GREL judgements. Overall, these data strongly suggest that the perception of the elevation of a visible obstacle and the perception of the ability of passing under in otherwise darkness shared common processes which are intimately linked to the GREL perception. The effect of body tilt upon these perceptions may illustrate an egocentric influence upon the semi-geocentric frame of reference required to perform the task. Possible interactions between egocentric and geocentric frames of reference are discussed.     

The influence of FDBA and autogenous bone particles on regeneration of calvaria defects in the rabbit: A pilot study

The histological behavior of bone formation using three biomaterials was examined including whether an 8 mm rabbit calvarial defect would behave as a critical size defect. Four trephine defects of 8 mm diameter in were created six rabbit parietal bones. A control defect was maintained only with coagulum and others were filled with autologous bone, FDBA (freeze dried bone allograft) and a mixture of autologous bone with FDBA, respectively. The animals were sacrificed after between 15 and 90 days at intervals of two weeks and the extracted samples were processed for histological evaluation. All control defects showed incomplete bone formation during 90 days of observation. The defects filled with FDBA and mixture of FDBA-autologous bone exhibited a higher regeneration degree than autologous bone after 60 days; however, the only biomaterial revealing complete mineralization of the original defect at 90 days was FDBA. In conclusion, 8 mm defects can be considered as critical size defects and only FDBA showed mature lamellar bone at 90 days.     

Randomized study assessing the influence of supervised exercises on ankle joint mobility in patients with venous leg ulcerations

Introduction

The aim of the study was to assess the influence of a supervised programme of exercises on ankle joint mobility in patients with venous leg ulcerations.

Material and methods

The study was carried out between 2008 and 2009 at the Venous Ulcer Treatment Outpatient Clinic and Clinic of General and Vascular Surgery of the Dr Jan Biziel University Hospital no. 2 in Bydgoszcz. It was a randomized control study in which 32 patients with venous leg ulcerations were qualified. Patients with ulcerations were randomized to 2 groups – 16 patients were included in the group with a supervised programme of exercises and the other 16 patients were included in the control group performing physical exercises by themselves, without supervision. The ranges of ankle joint mobility were assessed before, during and after the end of the 9-week exercise programme. A 32 cm goniometer with a scale from 0° to 180° with accuracy to 1° was used for measurements.

Results

In both groups a substantial increase of ankle joint mobility (p < 0.05) was observed. The total ankle joint mobility after completion of the exercises was significantly higher in the group performing exercises under the supervision of a nurse. Having a significant effect on the mobility of the ankle were the ulceration area, the extent of lipodermatosclerosis, and the intensity of symptoms and signs of CVI (p < 0.05).

Conclusions

Supervised physical exercises broaden the range of ankle joint mobility. They should constitute an integral part of a holistic model of care for patients with venous leg ulcerations.     

海水浸泡对火器伤兔肢体骨骼肌组织脂质过氧化反应影响的研究

目的:观察海水浸泡对火器伤伤口组织脂质过氧化反应的影响。方法:以滑膛枪发射质量250mg钢珠,致伤兔后肢,伤后将致伤兔随机分为两组:一组为海水浸泡组(SIG),将致伤兔浸泡于粗制海盐配制的人造海水中30min;另一组为单纯致伤组(SWG),伤后不浸泡海水。伤后3、6、12、24h手术取距伤道边缘0.5cm(A区)、1.5cm(B区)和2.5cm(C区)处肌组织,测定ATP、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力。取伤前骨骼肌组织作为对照。结果:伤后SIG兔伤肢骨骼肌MDA含量明显高于对照,伤后3、6h升高,12h略降,24h有再次升高的趋势。SWG的MDA含量变化与SIG相似,但升幅低于SIG;2组SOD活力和ATP含量的改变与MDA含量变化相似。结论:海水浸泡的火器伤伤口脂质过氧化反应增强,从而加重了肢体火器伤的过氧化反应。     

Clients' experience of change: An exploration of the influence of reformulation tools in cognitive analytic therapy

Case formulation is considered important in both the development of the therapeutic relationship and in starting the process of therapeutic change. Cognitive analytic therapy (CAT) describes the developmental origins and maintenance of a client's problems in both written (reformulation letter) and diagrammatic form (sequential diagrammatic reformulation). This study aimed to investigate the effects of these reformulation tools on insight and symptom change. A small‐N repeated measures design was employed with quantitative and qualitative measures collected from six therapist/client dyads. Participating therapists kept a record of their delivery of CAT reformulation tools. Participating clients completed the insight subscale of the Self‐Reflection and Insight Scale every fourth session and the Clinical Outcomes in Routine Evaluation‐10 every session. Qualitative data from client change interviews regarding their experiences of CAT and attributions of change was explored using template analysis. Participants demonstrated improvements (symptom reduction and insight increases) over the course of the intervention. Administration of reformulation tools did not consistently result in significant changes on insight and symptom measures. However, the tools were identified by participants as leading to insight and emotional change within the context of a good therapeutic relationship. These findings suggest that a genuine therapeutic relationship is an important change mechanism operating through, and strengthened by, CAT‐specific tools.     

术者经验对膝关节单髁置换术中的间隙平衡的影响：一项尸体研究

目的通过传感器技术,研究不同经验的术者在UKA术中所实现的间隙平衡是否有差别。方法依据术者既往单髁手术经验将术者分为无经验组、经验不足组及经验成熟组,通过压力传感器测量45例解冻尸体标本的单髁手术中的间隙压力,研究术者的手术经验是否与屈伸间隙平衡有关。结果经验成熟组术者的间隙平衡差为(53.19±43.47)N,显著低于经验不足组的(194.18±102.92)N和无经验组的(314.86±129.64)N(P<0.05)。而经验不足组与无经验组间差异无统计学意义(P>0.05)。结论术者的单髁手术经验与术中屈伸间隙平衡密切相关,而传感器技术可以帮助术者更加准确地判断间隙压力。     

Structure of the neointima after balloon catheter injury of the rabbit aorta in the context of hypercholesterolemia: analysis of endothelial influence on lipid accumulation

Balloon catheter de-endothelialization of abdominal aorta of cholesterol-fed rabbits was performed. As a result, partly endothelialized neointima was formed, consisting of smooth muscle cells and macrophages. Neutral lipids stored more intensely in non-endothelialized part of neointima. Preferential intracellular lipid accumulation in this area was observed while predominantly extracellular lipid accumulation was found in endothelium-covered part of neointima. It is supposed that endothelium inhibits intracellular lipid accumulation and at the same time stimulates an extracellular one, but as a whole it reduces the density of lipid inclusions in neointima.     

The use of a registry database in clinical trial design: assessing the influence of entry criteria on statistical power and number of eligible patients

Randomized clinical trials (RCTs) are prospective empirical studies used to investigate the effect of a particular medical intervention. The design of a clinical trial is a delicate decision process, as each of the decisions that are taken in this process influences the eventual result of the clinical trial. Despite the efforts that are put into trial design, many trials fail to show an effect of the intervention. In some of these situations the intervention may be truly ineffective, however, more often this is caused by problems with the inclusion of patients and a resulting lack of statistical power to show the effect. To avoid this problem, in the design of a trial, the statistical power that can be achieved with the current design choices is calculated and balanced with economic considerations. In the choice of the entry criteria however, an important step in the design process, the influence of the chosen criteria on statistical power and number of eligible patients is not quantified. As these criteria influence the characteristics of the study population and the number of patients that will be eligible for the trial, and thereby the chances of finding an effect of the intervention, we believe that also in the choice of entry criteria explicit estimates of the number of eligible patients should be made. This paper presents a method to arrive at precise, objective estimates of statistical power and the number of eligible patients, using a registry database. Furthermore, we describe how this method is incorporated in the process of choosing entry criteria for a clinical trial. We illustrate the method with an example in the area of severe sepsis.     

The influence of vascular β-adrenoceptors on the position and mobility of the rabbit incisor tooth

The influence of vascular β-adrenoceptors on the tooth-supporting functions of the periodontal ligament were studied in 30 anesthetized rabbits. Propranolol and the β₂-adrenoceptor antagonists ICI 118,551 and H 35/25 induced a marked extrusion of the incisor, probably due to reduced vasodilator tone in periodontal postcapillary blood vessels. Isoprenaline reversed the movement. β₁- and β₂-receptor antagonists decreased the intrusive responses to sympathetic nerve stimulation in teeth close to control position, but had no effect on responses in fully extruded teeth. Intrusive mobility, as tested by intermittent loading with 5–10 g, remained unaffected by β-adrenoceptor blockade. The results suggest that vascular β₂-adrenoceptors are important in the regulation of tooth position by their control of periodontal postcapillary resistance. Prejunctional β-receptors enhancing the vasoconstrictor - and intrusive - responses to sympathetic nerve stimulation are probably a mixture of β₁- and β₂-receptors. It would seem that the periodontal vasculature is important for the position of the rabbit tooth but, due to rapid adaptive mechanisms of the tooth-supporting tissues, the vasculature contributes little to the resistance against loadinduced intrusive movements of the tooth.     

The Hot Flush Beliefs Scale: a tool for assessing thoughts and beliefs associated with the experience of menopausal hot flushes and night sweats

OBJECTIVES: Approximately 15-20% of women experience their hot flushes and night sweats as problematic. There is some evidence that cognitive appraisals may help explain individual variation, and that cognitive behaviour therapy can alleviate related distress. This paper describes the development of the Hot Flush Beliefs Scale (HFBS), a questionnaire to assess women's appraisals, and reports on the reliability, validity and factor structure of the scale. METHODS: An initial pool of 63 items was generated from several sources: empirical literature, clinicians' views, and in-depth interviews, with the aim of reflecting common thoughts and beliefs about flushes and sweats. A total of 103 women, aged 41-64 years completed the initial measure. Principal components analysis and principal axis factoring were applied to the data, with both orthogonal and oblique rotation to determine the most coherent and interpretable solution. RESULTS: Exploratory factor analysis culminated in a 27-item measure comprising three dimensions: beliefs about self in social context; beliefs about coping with hot flushes; beliefs about coping with night sweats/sleep. The HFBS was internally consistent, with subscale alphas ranging from 0.78 to 0.93, and test-retest reliability 0.74-0.78. Validity was supported through correlations with other measures of mood and menopause beliefs. CONCLUSIONS: Preliminary analysis of the HFBS reveals it to be a psychometrically sound instrument. The HFBS has the benefit of being grounded in women's experiences and shows initial promise as a tool to aid further clinical and theoretical understanding of the impact of hot flushes and night sweats.