Evidence of Antineutrinos from Distant Reactors Using Pure Water at SNO.

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.

Assessing social anhedonia in adolescence: The ACIPS-A in a community sample.

To date, nearly all self-report measures of anhedonia have been developed for use with adult samples. A valid measure of anhedonia that can be used with adolescents would be useful in order to address key questions about the nature and course of anhedonia during adolescence. This study examined the psychometric properties of an adolescent version of a relatively new measure of social anhedonia, namely, the Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS-A). The ACIPS-A was administered to a general, community-derived Spanish adolescent sample of 449 students, including 251 males (55.9%), who ranged in age from 13 to 19 years old. Other measures included the Temporal Experience of Pleasure Scale (TEPS), anhedonia subscales from the Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), and the General Health Questionnaire-12 (GHQ-12). Exploratory factor analysis yielded a four-factor solution (close relationships, casual friendships and relationships, social bonding, and negative affiliation/emancipation). The total ACIPS-A showed excellent internal consistency, with ordinal alpha=0.95. The ACIPS-A total scores were positively correlated with the TEPS-Anticipatory scores (r=0.44, P<0.001) and TEPS-Consummatory scores (r=0.30, P<0.001) but not with total GHQ-12 scores. The ACIPS-A total scores were negatively correlated with social anhedonia subscale scores (r=-0.55) taken from a measure developed for use with adolescents. These results suggest that the ACIPS-A is a valid measure for use with non-clinical adolescents and is likely to prove useful for screening purposes.

Thought disorder in mid-childhood as a predictor of adulthood diagnostic outcome: findings from the New York High-Risk Project.

BACKGROUND: Thought disorder has been proposed as an indicator of schizotypy, which is considered to be necessary but not sufficient for the development of schizophrenia. It is unclear whether thought disorder is an indicator of susceptibility (i.e. an endophenotype) for schizophrenia. The goal of the present study was to elucidate the role of thought disorder in relation to schizotypy by examining its presence in high-risk individuals during mid-childhood. Method The sample consisted of 265 subjects drawn from the New York High-Risk Project. Individuals at high risk for schizophrenia (i.e. offspring of parents with schizophrenia) were compared with individuals at low risk for schizophrenia (i.e. offspring of parents with affective disorder or offspring of psychiatrically normal parents). Videotaped interviews were rated for thought disorder using the Scale for the Assessment of Thought, Language, and Communication (TLC). The same subjects were administered diagnostic interviews in late adolescence/early adulthood. RESULTS: Although positive thought disorder was equally present in subjects with affective and non-affective psychoses, negative thought disorder (namely, poverty of speech and poverty of content of speech) was elevated only in subjects with schizophrenia-related psychosis. Logistic regression analyses revealed that negative thought disorder added to the prediction of schizophrenia-related psychosis outcomes over and above positive thought disorder. CONCLUSIONS: These findings suggest that negative thought disorder may have a specific association with schizotypy, rather than a more general association with psychosis. The findings also support consideration of negative thought disorder as an endophenotypic indicator of a schizophrenia diathesis.

Temporal stability of saccadic task performance in schizophrenia and bipolar patients.

BACKGROUND: Identifying endophenotypes of schizophrenia will assist in the identification of individuals who are at heightened risk for the disorder. Investigators have proposed antisaccade task deficits as an endophenotypic marker of schizophrenia. However, the diagnostic specificity and the temporal stability of the task deficit are unresolved issues. To date, there are few published reports of test-retest stability of antisaccade task performance in psychiatric patients. METHOD: Twenty-three schizophrenia out-patients and 10 bipolar out-patients were administered two saccadic (antisaccade and refixation) tasks at two separate assessments, with an average test retest interval of 33 months. RESULTS: The schizophrenia patients displayed high test-retest reliabilities of antisaccade task accuracy, despite changes in medication and clinical status. Additionally, the schizophrenia group's saccadic reaction times for antisaccade correct responses and task errors were moderately stable over time. In contrast, the bipolar patients did not show temporal stability in their antisaccade task accuracy or in their response latencies to either correct or incorrect antisaccade responses. CONCLUSIONS: The results are supportive of the trait-like characteristics of antisaccade task deficits in schizophrenia patients. These findings also suggest that antisaccade task deficits may serve as an endophenotypic marker of schizophrenia.

The association between antisaccade task and working memory task performance in schizophrenia and bipolar disorder.

To date, the research literature has yielded conflicting reports regarding the specificity of antisaccade deficits to schizophrenia. We sought to examine antisaccade and working memory task performance in schizophrenia patients and bipolar patients, as well as to examine the relationship between the two tasks in both patient populations. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 nonpatient controls were administered saccadic inhibition (antisaccade), working memory, and sensorimotor tasks. Compared with the controls, the schizophrenia patients displayed both antisaccade deficits and working memory deficits. In contrast, the bipolar patients produced significantly more errors on the antisaccade task than the controls, though the bipolar group performed similarly to the control group on the working memory task. Mediational analyses demonstrated that working memory partially mediates the relationship between patients' diagnostic group status and antisaccade task performance; working memory performance contributed uniquely to the prediction of antisaccade task performance in the two patient groups. Antisaccade deficits do not appear specific to schizophrenia. The results suggest that in schizophrenia, working memory and antisaccade tasks are tapping similar cognitive processes, whereas in bipolar patients the processes underlying antisaccade and working memory performance are disparate.

Cognitive slippage in schizotypic individuals.

The Miers and Raulin Cognitive Slippage Scale was used to assess subtle thought disorder, and the Wisconsin Card Sorting Test (WCST) was used to assess cognitive performance in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (N = 63), high scorers on the revised Social Anhedonia Scale (N = 62), and in control subjects (N = 83). Results indicate that schizotypic individuals are more likely to report greater cognitive slippage and less likely to achieve as many WCST categories as controls. Individuals with both positive and negative symptoms of schizotypy reported higher levels of cognitive slippage than those individuals reporting only negative schizotypy. Additionally, the results confirm the presence of an especially high-risk group of psychosis-prone individuals, namely, those individuals with deviant scores on the revised Social Anhedonia Scale who possess additional indicators of schizotypy.

Evidence of schizophrenia patients' reduced perceptual biases in response to emotion chimera.

The goal of the study was to determine whether dextral individuals with schizophrenia display atypical perceptual biases in response to faces in general, or whether they display atypical perceptual biases in response to emotional facial cues. To this end, we assessed perceptual processing in schizophrenia patients with four types of free-vision chimeric stimuli. Perceptual biases were evaluated in 45 schizophrenia patients and in 46 controls using two face (emotion, gender) tasks and two nonface (dots, gradients) tasks. In response to the emotion chimera, the patients with schizophrenia displayed a reduced left perceptual bias. The two groups did not differ significantly in their response to the gender chimera or to the two nonface chimera. These findings are consistent with the assertion that schizophrenia patients have impaired emotional perception. In the discussion we consider possible reasons for schizophrenia patients' difficulty comprehending emotional facial stimuli. We suggest that schizophrenia patients' reduced perceptual bias in response to the emotion chimera reflects a hypothesized affective information-processing deficit.

Smooth pursuit eye tracking and visual fixation in psychosis-prone individuals.

Subjects identified by Perceptual Aberration-Magical Ideation (Per-Mag) scores (n=97), Social Anhedonia (SocAnh) scores (n=45), and Physical Anhedonia (PhysAnh) scores (n=31) as well as normal controls (n=94), underwent psychophysiological and clinical assessment. This is the first published investigation of pursuit system functioning in three groups of questionnaire-identified at-risk individuals. Pursuit during a simple non-monitor tracking task was measured using root-mean-square error (RMSE) scores and pursuit gain scores. Fixation performance was measured in terms of number of saccades away from the central fixation point. The at-risk subjects were more likely to display aberrant smooth pursuit tracking than controls, though there were no significant differences between the at-risk subjects endorsing items relevant to positive-symptom schizotypy and those endorsing items pertaining to negative-symptom schizotypy. The groups did not differ significantly in their visual fixation performance. Participants were also evaluated for the presence of Axis I symptomatology and psychotic-like experiences. Neither the experimental subjects nor the control subjects displayed a significant association between ocular motor performance and psychotic-like experiences. These findings are consistent with prior evidence that pursuit tracking is a trait characteristic, independent of clinical status.

Fixation stability in schizophrenia, bipolar, and control subjects.

A few investigators have suggested that visual fixation abnormalities may serve as an endophenotype of liability for schizophrenia. However, the data are equivocal. Conflicting reports regarding the specificity of fixation deficits to schizophrenia may be attributable to methodological differences. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 non-patient controls were presented targets for central fixation. Fixation was scored in terms of frequency of saccades as well as qualitative ratings. Analysis of variance on the number of saccades produced during fixation revealed that the three groups did not differ. Similarly, we observed that the schizophrenia patients did not differ from either bipolar patients or controls in terms of ratings of fixation quality. It appears that schizophrenia patients are not characterized by poor visual fixation. The findings are discussed in terms of the viability of visual fixation as a marker of schizophrenic diathesis, as well as possible implications for the analysis of schizophrenia patients' visual search performance.

Smooth pursuit and saccadic eye movement performance in a prefrontal leukotomy patient.

The authors wished to examine the role of the prefrontal cortex in oculomotor performance. They assessed smooth pursuit and saccadic performance in a patient with schizophrenia who had undergone a bilateral prefrontal leukotomy. Her performance on neuropsychological test measures sensitive to frontal lobe functioning were also examined. Against a background of intact intellectual and neurological functioning, the patient displayed a dissociation in premotor and prefrontal functioning. Smooth pursuit performance was within normal limits, as were the patient's finger tapping scores. In contrast, the patient performed poorly on the Wisconsin Card Sorting Test, and verbal and design fluency tasks. Similarly, her performance on the antisaccade task was markedly deviant. Despite advanced age and a frontal leukotomy, this patient with schizophrenia displayed intact smooth pursuit, indicating that the frontal cortex is not necessary for normal smooth pursuit performance.

Perceptual biases in psychosis-prone individuals.

College students screened for psychosis-proneness using the Chapman scales were compared on 4 free-vision tasks that typically yield left-spatial-field biases. The tasks included 2 chimeric face tests, consisting of happy/neutral faces and male/female faces, and 2 nonface tasks, consisting of pairs of dot-filled or gradient-filled rectangles. Participants endorsing perceptual aberration items, magical ideation items, or both (n = 98) and control participants (n = 112) were left-biased on all tasks but gradients and were most biased on emotion faces; in contrast, i.e., social anhedonia participants (n = 40) displayed very little or no left-field biases. For all groups, task intercorrelations were greatest between the 2 face tasks and between the 2 nonface tasks. These findings suggest patterns of atypical perceptual asymmetry in psychosis-prone individuals.

Antisaccade task performance in questionnaire-identified schizotypes.

Individuals who scored high on Perceptual Aberration-Magical Ideation Scales (Per-Mag; n = 90), the Social Anhedonia Scale (SocAnh; n = 39), and control participants (n = 89) were administered saccadic refixation (prosaccade) and saccadic suppression (antisaccade) tasks. Eye movements were scored in terms of error rates and latency. None of the groups differed in terms of their performance on the prosaccade task. Both the Per-Mag (p < 0.01) and SocAnh (p < 0.05) groups exceeded the controls in terms of mean antisaccade errors. The high-risk groups did not differ from each other. Eighteen of the Per-Mag individuals and 10 of the SocAnh individuals displayed deviant antisaccade performance. These findings are particularly interesting in light of suggestive evidence that antisaccade task deficits may serve as a marker of susceptibility to schizophrenia. It is hypothesized that the individuals who scored aberrantly on the Chapman scales and displayed antisaccade performance deficits are most likely to be at risk for the development of psychosis.

Wisconsin Card Sorting Test deficits in schizotypic individuals.

The present study investigates executive functioning in schizotypic college students and control subjects using the Wisconsin Card Sorting Test (WCST). Inhibitory control and working memory, two aspects of executive functioning, were examined in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (n=97), high scorers on the revised Social Anhedonia Scale (n=58), and in control subjects (n=104). The schizotypic groups displayed significantly more perseverative errors and achieved fewer categories than the control group. The two schizotypic groups did not differ from each other. We identified a subset of schizotypic individuals who also produced clinically deviant WCST profiles. The findings support the hypothesis that executive function deficits may precede the onset of schizophrenia and related illnesses.

Working memory and Wisconsin Card Sorting Test performance in schizotypic individuals: a replication and extension.

The present study examined spatial working memory and Wisconsin Card Sorting Test (WCST) performance in psychosis-prone individuals, either those with extremely high scores on the Social Anhedonia Scale (SocAnh; n = 49) or deviant scores on the Perceptual Aberration-Magical Ideation Scales (Per-Mag; n = 66). Sixty-three individuals with normal scores on the Chapman Psychosis-Proneness Scales served as control subjects. In order to evaluate working memory performance, participants were administered three tasks, namely, sensorimotor, degraded stimulus, and delayed-response tasks. Although the SocAnh and Per-Mag groups displayed poorer performance than control subjects on the working memory task, they did not differ significantly from each other. The SocAnh group exhibited slower reaction times on the working memory task compared to the control group. The groups did not differ in their performance on sensorimotor or degraded stimulus control tasks. Both psychosis-prone groups differed significantly from control subjects in terms of their WCST performance. Working memory performance was inversely associated with the number of perseverative errors (r = -0.17) and the number of trials to complete the first category on the WCST (r= -0.15). These findings extend the literature by indicating that some psychosis-prone individuals with social-interpersonal schizotypal deficits also display subtle spatial working memory impairments.

Nailfold capillary plexus visibility in relation to schizotypy.

High plexus visibility is a potential biological marker of a schizophrenia diathesis. Plexus visibility was assessed in college students endorsing schizotypal traits and normal controls. Twenty-two (nearly 14%) of the 160 schizotypal individuals displayed the trait. None of the controls (n = 99) showed high plexus visibility. These results provide supportive evidence for an association between increased plexus visibility and schizotypy.

Temporal stability of smooth-pursuit eye tracking in first-episode psychosis.

We evaluated the temporal stability of smooth-pursuit eye tracking in 38 schizophrenic, 42 nonschizophrenic psychotic (bipolar, depressive, paranoid psychotic, and schizophreniform), and 49 normal subjects. Pursuit performance was evaluated on two testing occasions separated by approximately 9.5 months. Retest reliability coefficients of root mean square (RMS) error scores for schizophrenic and normal subjects were .68 and .57, respectively. The reliability coefficients of RMS error scores for the nonschizophrenic psychotic patients ranged from .44 to .51. Level of psychological functioning was not significantly related to tracking performance, and most patients' pursuit performance remained stable despite changes in medication and clinical status. These results support the hypothesis that eye tracking dysfunction is a trait characteristic that can serve as a vulnerability indicator of schizophrenia.

The association between lithium carbonate and smooth pursuit eye tracking among first-episode patients with psychotic affective disorders.

The association between treatment with lithium carbonate and smooth pursuit eye tracking performance was investigated in first-episode patients with psychotic affective disorders. The horizontal pursuit performance of patients with major depression and bipolar disorder who were receiving lithium carbonate was contrasted with that of patients not receiving lithium carbonate. In addition, the accuracy and quality of pursuit eye tracking was examined in bipolar patients whose lithium status changed from the time of initial testing to the time of retest 10 months later. For the combined group of depressed and bipolar patients, treatment with lithium carbonate was not associated with worse pursuit performance. Bipolar disordered patients on lithium did not differ in tracking proficiency from those not on lithium; bipolar patients whose lithium status changed from intake to retest also did not display a significant change in pursuit performance.

Epidural hydromorphone with and without epinephrine for post-operative analgesia after cesarean delivery.

The efficacy of epidural hydromorphone alone or in combination with epinephrine for postoperative analgesia was evaluated in 30 healthy women who underwent cesarean delivery with epidural anesthesia. They were assigned randomly to receive either 1.5 mg hydromorphone alone (N = 15) or 1.5 mg hydromorphone with 1/200,000 epinephrine (N = 15). Duration of analgesia (mean +/- SD) was 24.3 +/- 9.4 hours after the epidural injection of hydromorphone plus epinephrine. This was significantly greater (p less than 0.01) than the duration of 18.2 +/- 5.9 hours after the same dose of plain hydromorphone. Analgesia was more rapid in onset and significantly better at the 0.5, 1, 3, and 12 hours postoperatively in the hydromorphone-epinephrine group. Side effects including pruritus (73%), nausea (20%), and vomiting (15%) were of similar frequency with and without epinephrine. Although mean venous PCO2 (PvCO2) levels three and six hours after the hydromorphone-epinephrine dose were elevated significantly over the pre-drug PvCO2 levels, no respiratory depression was detected by an apnea monitor to which all patients were connected. The addition of epinephrine to epidural hydromorphone hastened onset and prolonged the duration of analgesia after cesarean section.

Comparison of porous silica packing materials for preparative ion-exchange chromatography.

Although analytical high-performance liquid chromatographic columns have been successfully used for purification of milligram amounts of proteins, they do not appear to be ideal for preparing gram or kilogram quantities because of cost and load capacities. In this paper the development of preparative weak anion-exchange materials is described. These materials possess similar chromatographic characteristics to analytical 5-10 micron materials, yet also have high load capacities. A number of inorganic packings were examined to determine which had the best combination of high load capacity, good resolution, stability, and low cost. When appropriate flow-rates and gradient shapes were used, 30-50 micron materials produced resolution of components of a commercial ovalbumin sample that was comparable to that achieved on a 6-micron material. An amount of 3 g of a protein could be loaded onto a 250 X 21 mm-I.D. column with adequate resolution to separate it from some of its impurities.