Virtual Reality Could Help Assess Sexual Aversion Disorder

Virtual reality (VR) may improve our understanding of sexual dysfunctions' manifestations, although research in this area remains limited. This study assessed the potential use of a VR Behavior Avoidance Test (VR-BAT) as a tool for examining the clinical features of Sexual Aversion Disorder (SAD): the experience of fear, disgust, and avoidance when facing sexual cues/contexts. A sample of 55 adults (≥ 18y) with (n = 27) and without SAD (n = 28) completed a self-report measure of sexual avoidance. Their anxiety, disgust, electrodermal activity, heart rate, and visual and behavioral avoidance were then examined during two VR-BATs involving sexual or non-sexual stimuli. Mixed repeated measures ANOVAs, t-tests, and correlational analyses were performed. Results showed that individuals in the SAD group reported greater anxiety and disgust compared to their non-SAD counterparts during the sexual stimuli condition. Sexual avoidance scores were largely positively related to anxiety and disgust during the VR sexual condition, and moderately negatively related to the time spent touching the virtual character's genitals. This study is important given the prevalence of sexual difficulties, such as SAD, and the new research avenues offered by emerging technologies, like VR.

Hot for Robots! Sexual Arousal Increases Willingness to Have Sex with Robots

Robots designed to elicit sexual arousal are coming. Sexual arousal can increase our willingness to engage in risky or unconventional sexual behaviors. However, researchers have yet to examine whether this effect extends to robots. Hence, this study provides the first empirical evidence that state sexual arousal can increase our willingness to engage erotically with robots. Based on previous research, we hypothesized that levels of sexual arousal would positively predict willingness to engage erotically with robots (Hypothesis 1); and that men would be more willing to engage erotically with robots than women (Hypothesis 2). A convenience sample of 321 adults (≥18y) completed a two-part online survey measuring their willingness to have sex with, love, engage in an intimate relationship with, and be friends with a robot and a human before and after viewing a sexually explicit video. The results partly support Hypotheses 1-2. They show that state sexual arousal increases willingness to have sex with a robot, and that men are more willing to have sex and engage in an intimate relationship with a robot than women, pre- and post-manipulation. These findings are important given the rise of sex robots and their potential influence on our intimate decisions and behaviors.

The Case for Space Sexology

Space poses significant challenges for human intimacy and sexuality. Life in space habitats during long-term travel, exploration, or settlement may: detrimentally impact the sexual and reproductive functions of astronauts, restrict privacy and access to intimate partners, impose hygiene protocols and abstinence policies, and heighten risks of interpersonal conflicts and sexual violence. Together, this may jeopardize the health and well-being of space inhabitants, crew performance, and mission success. Yet, little attention has been given to the sexological issues of human life in space. This situation is untenable considering our upcoming space missions and expansion. It is time for space organizations to embrace a new discipline, space sexology: the scientific study of extraterrestrial intimacy and sexuality. To make this case, we draw attention to the lack of research on space intimacy and sexuality; discuss the risks and benefits of extraterrestrial eroticism; and propose an initial biopsychosocial framework to envision a broad, collaborative scientific agenda on space sexology. We also underline key anticipated challenges faced by this innovative field and suggest paths to solutions. We conclude that space programs and exploration require a new perspective - one that holistically addresses the intimate and sexual needs of humans - in our pursuit of a spacefaring civilization.

A Framework for Developing Pharmacotherapy for Agitation in Alzheimer's Disease: Recommendations of the ISCTM* Working Group

Dementia is characterized by a significant decline in one of several cognitive domains such as memory, language and executive function, affecting independence and representing a significant deterioration from a previous level of functioning (1). Alzheimer’s Disease (AD) represents the most common form of dementia and contributes up to 70% of the almost 50 million dementia cases worldwide, a number that is projected to double in 20 years (2).

A Literature Review of Methodologies Used in Randomized Clinical Trials of Agitation in Alzheimer's Disease

Agitation is a common and burdensome symptom associated with Alzheimer's disease (AD). This is a narrative literature review of the designs and methods used in randomized clinical trials of agitation in patients with AD; sources range from published, to completed but not published, to ongoing studies in the past 10 years. Selection for review included blinded, randomized trials conducted to assess the effect of a pharmacological intervention for which agitation in patients with AD was among the prespecified end points. Key criteria for exclusion included open-label studies, trials of dementia not specific to AD, or mixed populations of AD and unspecified dementia. A search of PubMed and clinicaltrials.gov databases identified 36 trials for which agitation was among the prespecified end points: 18 were published trials and 18 were completed but not published or ongoing. There was significant heterogeneity among AD studies in terms of diagnostic criteria, assessment of severity of disease and agitation, sample size and powering assumptions, treatment duration, patient age and cognitive status, and outcomes measurements. Few studies used a mitigation strategy for placebo response. Accumulating evidence suggests that it is important to consider the following in trial design: thresholds for baseline severity of agitation and AD; use of prespecified accepted criteria to define agitation; and use of standardized, validated tools to measure treatment effects during a trial. Adoption of these design strategies might help improve signal detection and bring us closer to identifying the most appropriate, effective, and safe treatments for agitation in patients with AD.

Fatal Clostridium difficile enteritis caused by the BI/NAP1/027 strain: a case series of ileal C. difficile infections

Clostridium difficile generally causes diarrhoea and colitis. Small-bowel infections are considered to be rare. Twelve cases of ileal C. difficile infections are presented, including the first reported case proven to be caused by the hypervirulent BI/NAP1/027 strain. This case series suggests that small bowel involvement in C. difficile infections may be more frequent than previously thought.

Non-patient factors related to rates of ruptured appendicitis

BACKGROUND

Adult rates of ruptured appendicitis vary from 13.2 to 41.9 per cent in urban hospitals, despite controlling for individual factors. This suggests an effect of hospital organization. Surgeons report that appendicectomies may be delayed because of lack of access to operating rooms.

METHODS

Combining interviews with hospital personnel and information from medical records for 1998-1999, a cross-sectional study using logistic regression, taking hospital clustering of patients into account, was conducted on 861 patients from 12 hospitals. Hospitals were grouped into organizational models. The diagnostic information was recoded to ensure interhospital validity.

RESULTS

Hospitals with high activity and volumes of patients, but without an operating room designated for urgent surgery, were associated with a significantly higher risk of peritonitis (P<0.050). Time to surgery was very long in all hospitals, particularly time after departure from the emergency department and for elderly patients.

CONCLUSION

Organizational characteristics, in unfavourable combinations, influence the course of time-dependent diseases such as appendicitis. Difficulties in gaining access to operating rooms, even for urgent operations, have emerged. Delays in treatment must be addressed when planning healthcare reforms.

The Quebec Association of Gastroenterology position paper on colorectal cancer screening - 2003

Colorectal cancer is a leading cause of death and the third most common cancer in Canada. Evidence suggests that screening can reduce mortality rates and the cost effectiveness of a program compares favourably with initiatives for breast and cervical cancer. The objectives of the Association des gastro-entérologues du Québec Task Force were to determine the need for a policy on screening for colorectal cancer in Quebec, to evaluate the testing methods available and to propose one or more of these alternatives as part of a formal screening program, if indicated. Fecal occult blood testing (FOBT), endoscopy (including sigmoidoscopy and colonoscopy), barium enema and virtual colonoscopy were considered. Although most clinical efficacy data are available for FOBT and sigmoidoscopy, there are limitations to programs based on these strategies. FOBT has a high false positive rate and a low detection yield, and even a combination of these strategies will miss 24% of cancers. Colonoscopy is the best strategy to both detect and remove polyps and to diagnose colorectal cancer, with double contrast barium enema also being a sensitive detection method. The Task Force recommended the establishment, in Quebec, of a screening program with five- to 10-yearly double contrast barium enema or 10-yearly colonoscopy for individuals aged 50 years or older at low risk. The program should include outcome monitoring, public and professional education to increase awareness and promote compliance, and central coordination with other provincial programs. The program should be evaluated; specific billing codes for screening for colorectal cancer would help facilitate this. Formal feasibility, effectiveness and cost-effectiveness studies in Quebec are now warranted.

[Could we trust clinical statistics from data banks of the National Health Service (NHS)?]

Can we accept the statistics provided by the Ministry of Health, which uses large computerized databases? Through MEDECHO, the Ministry provides to hospital managers, reports cards on different interventions. These reports compare different hospitals performances. Surgeons involved in the process hesitate to accept this information. Using the results of the performance of cholecystectomy provided by this system (Gr: A), we compared the same cohort (1 April-31 December 1996 = 346 cholecystectomies) but using specific criteria determined as relevant to our surgeons (Gr: B). The rate of complication gives a crude aftermath and no attempt was used to adjust for severity. The MEDECHO data are adjusted for severity. The global rate of complications is similar Gr: A 11%, Gr: B 12%. Major complication rate for pulmonary embolism, hemorrhage and biliary duct trauma are identical. The rate of surgical site infection is higher in Gr: B (5% vs. 2%). The patients are seen in the outpatient clinic and these observations are not included by the analytical system unless the patient has been readmitted. For our hospital, the MEDECHO data are valid and reliable even though they underestimated the wound infection rate. These results could be explained by an appropriate interpretation of the code system by the archivist and by the surgeons' precision to complete the summary sheet of hospitalization. We can conclude that these data can be used as a means to evaluate the quality of outcome of a surgical service.

Acquisition of lexical morphology in simple partial epilepsy

In the study of language acquisition following early brain damage, results have been divergent. On one hand, some studies claim that language eventually resumes to normal, whereas, on the other hand, studies show lasting deficits throughout development. Discrepancies in the results could arise from different etiologies and tests used. This study attempts to determine the extent to which the development of verb production is affected in later development in children who had simple partial epilepsy (SPE). Measures of diversity and fluency of three verb types, namely main verbs, auxiliary and copula verbs, and nonfinite verbs were used on three children diagnosed as SPE and compared to control groups. Our main results show a limited production of auxiliary verbs. Further analysis of their productions suggest a telegraphic style of speech, as reflected by a superior production of nonfinite verb type compared with normal children. These findings are interpreted as reflecting long-lasting consequences of early brain damage with respect to language development.

The safe use of epidural anesthesia after subcutaneous injection of low-dose heparin in general abdominal surgery

OBJECTIVE

To determine if epidural anesthesia after the subcutaneous injection of low-dose unfractionated heparin (LDUH) in patients who undergo elective bowel surgery is safe with respect to hemorrhagic complications.

DESIGN

A prospective cohort study.

SETTING

Two hospitals affiliated with the Université de Montréal.

PATIENTS

Fifty patients scheduled for elective bowel surgery.

INTERVENTION

Subcutaneous injection of 5000 units of LDUH and elective surgery for colonic carcinoma, chronic diverticulosis or inflammatory bowel disease.

MAIN OUTCOME MEASURES

Activated partial thromboplastin time (APTT), anti-IIa and anti-Xa heparin levels measured before and 2 and 4 hours after injection of LDUH.

RESULTS

In no case was the heparin anti-IIa or anti-Xa level higher than 0.20 U/mL, which is considered a significant detectable level of heparin.

CONCLUSION

LDUH given subcutaneously is not associated with significant detectable heparin levels, so epidural anesthesia should be safe when performed 2 hours after LDUH injection in patients who undergo general abdominal surgery in the absence of any other impairment of hemostasis.

Clinimetric scale to measure surgeons' satisfaction with anesthesia services

PURPOSE

Continuous quality improvement is of increasing interest to anesthesiologists. Since surgeons are coworkers and important clients of anesthesiologists, the level of satisfaction of surgeons with anesthesia services should be explored to optimize quality. The purpose of this study was, first, to introduce the concept of surgeons as clients of anesthesiologists and second, to develop and test an instrument to measure surgeons' satisfaction, the Surgeon Satisfaction with Anesthesia Services (SSAS) scale.

METHODS

A conceptual model of surgeon satisfaction with anesthesia services was created before the development of the SSAS scale. The scale, composed of socio-demographic, Likert-type and open-ended questions was sent to a sample of 250 surgeons selected randomly by the Collège des Médecins du Québec. Exploratory factorial analysis were performed on the results.

RESULTS

A Cronbach's alpha of 0.84 was obtained for internal consistency. Exploratory factorial analysis yielded two subscale factors: a) clinical expertise and b) attitudes and behaviour Global mean of surgeons'satisfaction was moderately high (3.11/4.0). Satisfaction was not related to sociodemographic variables. Very high scores were obtained for items related to clinical expertise. Items related to attitudes and behaviour obtained lower scores. A significant difference was obtained between both factors (t = -5.732, P = 0.0001).

CONCLUSION

The SSAS scale is a new instrument to evaluate surgeon satisfaction. Overall, surgeons seem satisfied with anesthesia services, but many areas of dissatisfaction persist. Further discussions with surgeons should be encouraged, in view of improving the perceptions of the quality of anesthesia services and interprofessional relationships.

[Recurrence and satisfaction levels following onysectomy with or without phenolization]

OBJECTIVE

To compare recurrence and satisfaction levels among patients undergoing onysectomy with phenolization (OP) and without phenolization (OS).

DESIGN

Retrospective cohort study.

SETTING

Family practice unit.

PARTICIPANTS

All patients (N = 35) undergoing onysectomy between September 1992 and May 1993, and between January 1996 and February 1997.

MAIN OUTCOME MEASURES

Type of onysectomy (OP or OS) was taken from the patient's medical record. A telephone interview was used to determine whether patients had experienced recurrence; satisfaction was measured retrospectively at diagnosis, at time of surgery, and after surgery using a five-point scale (very unsatisfied to very satisfied).

RESULTS

Among the 30 patients interviewed by telephone, four of the six patients in the OS group experienced recurrence, and four of the 24 patients in the OP group experienced recurrence. (Fisher's exact test, P = .007). In the OS group, satisfaction levels at diagnosis, during surgery, and after surgery were 4.7, 4.5, and 4.2, respectively. In the OP group, satisfaction levels at these three points were 4.3, 4.2, and 4.4, respectively. Notwithstanding technique used, a connection was noted between recurrence and satisfaction level at the time of the telephone interview (repeated measures test, P = .036).

CONCLUSION

In general medicine, onysectomy with phenolization could be the treatment of choice for ingrown toenails.

[Assessment of the quality of life during adjuvant chemotherapy of colorectal cancer]

Enhanced 5 year survival rates with adjuvant chemotherapy for colon and rectal cancers are 5% and 9% respectively, according to recent meta-analysis. Despite the NIH consensus statement endorsing adjuvant chemotherapy, many clinicians regard such a seemingly small benefit not justworthy of the expense, inconvenience, discomfort and risk of treatment for their individual patient with colorectal carcinoma. The aim of this study is to evaluate these quality of life issues. The seven criteria considered most important were determined by interviews of treated patients, who emphasized the following quality of life parameters: nausea and vomiting, diarrhea, perineal dermatitis, asthenia, impairment of daily activity, family support, and difficulties of daily transportation to hospital. A numeric scale (1-5) was used to measure their answers (0 = hospitalization, 5 = no modification), and the nonparametric rank coefficient of Kendall was used to compare them. Twenty patients with colon cancer treated with Moertel's protocol and 5 patients with rectal cancer treated with Krook's protocol were evaluated. The study revealed a diminished quality of life for both patients with colon cancer (7 on a scale of 10) and those with rectal cancer (6 on the same scale). By using the same questionnaire at one week interval, the responses remained unchanged (p < 0.001). The effect of radiotherapy seems to be responsible for this difference. This study is one of the first to approach the quality of life from the real interested party's point of view: the patient.

Bowel preparation with polyethylene glycol electrolyte lavage solution is potentially hazardous in patients with carcinoma of the cardia: a case report

Polyethylene glycol (PEG) electrolyte solution can induce potentially fatal complications when used as a lavage in preoperative bowel preparation. A 60-year-old man with carcinoma of the esophagogastric junction had a Mallory-Weiss tear after bowel preparation with PEG. He was successfully resuscitated, first with balanced salt solution then by transfusion. The literature on the subject is reviewed and recommendations are made, which include consideration of alternative methods of bowel preparation (e.g., sodium phosphate solution) in patients with esophageal obstruction.

Acute colonic surgery and unrecognized hypothyroidism: a warning. Report of six cases

PURPOSE

This study was designed to highlight the significant morbidity related to undetected hypothyroidism in the elderly who are undergoing emergency surgery.

METHOD

Case reports of six patients who presented with acute colonic surgical conditions are reviewed.

RESULTS

Six cases of undetected hypothyroidism in a group of elderly patients was unmasked at the time of surgery for acute colonic conditions or in the perioperative period. These patients experienced increased morbidity, but once detected and treated, all but one had an uneventful recovery.

CONCLUSION

Unrecognized hypothyroidism may lead to unnecessary surgery or even a potentially fatal outcome. A heightened awareness of this not so uncommon entity is mandatory.

Adjuvant chemotherapy in colorectal carcinoma: results of a meta-analysis

Despite the National Institutes of Health consensus regarding use of adjuvant chemotherapy in colorectal carcinoma, many general surgeons question the efficacy of this approach when considering costs involved for both the individual patient and society at large.

PURPOSE

This study was designed to determine the real impact of adjuvant chemotherapy on five-year survival rates of patients.

METHOD

A qualitative and quantitative meta-analysis of results from 39 randomized clinical trials published from 1959 to 1993 is described.

RESULTS

Design quality of clinical trials had a mean score of 48.6 percent (+/-6.2 standard deviation). A small benefit of therapy in terms of overall survival was noted, with a mortality odds ratio (OR) of 0.91 (confidence interval (CI) 95 percent, 0.83-0.99). For the group of colon carcinomas, the OR was 0.81 (CI 95 percent, 0.69-0.94) with an OR of 0.64 (CI 95 percent, 0.48-0.85) for the group of rectal carcinomas. The effect size was 0.09 for the colon group and 0.20 for the rectal group. For those patients who receive chemotherapy, this effect size implies that we can expect an increase of 5 percent in the survival rate in the group with colon carcinoma and a 9 percent increase in the survival rate in the group with rectal carcinoma.

CONCLUSION

Given the high incidence of colorectal carcinoma, the small benefit observed for those patients receiving chemotherapy is far from negligible. However, indications for adjuvant chemotherapy warrant further discussion.

Two contributions of motion induction: a preattentive effect and facilitation due to attentional capture

By combining the paradigms of motion induction (presentation of an inducing stimulus, followed after a short delay by the presentation of an elongated bar next to it) and visual search (many-item displays with or without a pop-out target), it was possible to demonstrate the existence of two separate contributions to the motion induction effect. Illusory motion in the test bar could be produced either preattentively or by facilitation due to attentional capture. The former effect is fast, independent of the delay between the inducers and the test bar and operating simultaneously at all locations across the visual display, the latter is slower (full strength in 200-300 msec) and confined to the vicinity of the pop-out inducer. The two possibly also differ in their spatial extent, the attentional capture effect extending over a larger area around the inducer. We conclude that the motion induction effect can be used to show the existence of several effects due to the sudden presentation of a visual stimulus.

Hypothalamic-pituitary-adrenocortical activity and response to cognitive behavior therapy in unmedicated, hospitalized depressed patients

OBJECTIVE

Surprisingly little research supports the hypothesis that depressions characterized by objective measures of neurobiological dysregulation respond poorly to psychotherapy. Moreover, relevant studies testing this hypothesis have been compromised by low rates of neurobiological abnormality in outpatient samples. The authors therefore investigated response to cognitive behavior therapy in relation to pretreatment measures of hypothalamic-pituitary-adrenocortical (HPA) activity in hospitalized, yet unmedicated, patients.

METHOD

The subjects were 29 unmedicated, hospitalized patients with major depression (DSM-III-R and Schedule for Affective Disorders and Schizophrenia/Research Diagnostic Criteria), nonpsychotic/nonbipolar subtype. After a 7- to 14-day evaluation, urinary free cortisol levels and dexamethasone suppression tests (DSTs) were obtained. Patients were treated for an average of 3 weeks with intensive individual cognitive behavior therapy. Response was assessed in relation to clinical severity of illness and pretreatment HPA parameters.

RESULTS

Response to inpatient cognitive behavior therapy was inversely associated with pretreatment urinary free cortisol concentrations, although not strongly correlated with DST results. Overall, 12 (92%) of 13 cortisol suppressors on the DST who had normal urinary free cortisol concentrations responded to treatment, compared with only seven (44%) of the 16 patients characterized by nonsuppression of cortisol and/or elevated urinary free cortisol excretion. The relation between response to cognitive behavior therapy and HPA activity was not explained by clinical measures of symptom severity.

CONCLUSIONS

Results are consistent with the hypothesis that patients with increased HPA function are less responsive to psychotherapy and, hence, might require somatic interventions. It is proposed that the negative impact of hypercortisolism on neurocognitive function mediates this relationship.

Sertraline safety and efficacy in major depression: a double-blind fixed-dose comparison with placebo

In a 6-week, randomized, double-blind, multicenter trial, sertraline 50 mg, 100 mg, or 200 mg, or placebo, was administered once daily to 369 patients with DSM-III-defined major depression. Efficacy variables included changes from baseline scores for total Hamilton Rating Scale for Depression (HAMD), HAMD Bech Depression Cluster, Clinical Global Impressions (CGI) Severity, CGI Improvement, and Profile of Mood States Depression/Dejection Factor. For the evaluable-patients analysis, all sertraline groups showed significantly (p < 0.05 or better) greater improvements in all efficacy variables except one when compared with the placebo group. For the all-patients analysis, all efficacy variables in the 50 mg group were statistically significantly (p < 0.05) better than placebo. Side effects increased with increasing dosage but were usually mild and well tolerated. The results of this study show that sertraline 50 mg once daily is as effective as higher dosages for the treatment of major depression with fewer side effects and therapy discontinuations.

Visual search asymmetry for viewing direction

In visual search experiments, we examined the existence of a search asymmetry for the direction with which three-dimensional objects are viewed. It was found that an upward-tilted target object among downward-tilted distracting objects was detected faster than when the orientation of target and distractors was reversed. This indicates that the early visual process regards objects tilted downward with respect to the observer as the situation that is more likely to be encountered. That is, the system is set up to expect to see the tops of these objects. We also found a visual field anisotropy, in that the asymmetry was more pronounced in the lower visual field. These findings are consistent with the idea that the tops of objects are usually situated in the lower visual field and less often in the upper field. Examination of the conditions under which the asymmetry and the anisotropy occur demonstrated the importance of the three-dimensional nature of the stimulus objects. Early visual processing thus makes use of heuristics that take into account specific relationships between the relative locations in space of the observer and 3-D objects.

Local and global factors of similarity in visual search

Effects of the similarity between target and distractors in a visual search task were investigated in several experiments. Both familiar (numerals and letters) and unfamiliar (connected figures in a 5 x 5 matrix) stimuli were used. The observer had to report on the presence or absence of a target among a variable number of homogeneous distractors as fast and as accurately as possible. It was found that physical difference had the same clear effect on processing time for familiar and for unfamiliar stimuli: processing time decreased monotonically with increasing physical difference. Distractors unrelated to the target and those related to the target by a simple transformation (180 degrees rotation, horizontal or vertical reflection) were also compared, while the physical difference was kept constant. For familiar stimuli, transformational relatedness increased processing time in comparison with that for unrelated stimulus pairs. It was further shown in a scaling experiment that this effect could be accounted for by the amount of perceived similarity of the target-distractor pairs. For unfamiliar stimuli, transformational relatedness did have a smaller and less pronounced effect. Various comparable unrelated distractors resulted in a full range of processing times. Results from a similarity scaling experiment correlated well with the outcome of the experiments with unfamiliar stimuli. These results are interpreted in terms of an underlying continuum of perceived similarity as the basis of the speed of visual search, rather than a dichotomy of parallel versus serial processing.

The interaction of depth parameters in motion integration with polar plaids

Many parameters have been investigated as to their effect on the way in which the visual system is able to integrate different motion directions at the same visual location. Of special interest have been parameters that determine the depth relationship between surfaces, such as disparity, relative contrast, and occlusion versus transparency. The preferred stimulus for this research has been the 'plaid', usually constructed from two linear gratings. The present study concentrated not on these Cartesian plaids, but on polar plaids, made from a combination of concentric circles and radial gratings. These kinds of plaids also have a special theoretical significance: within the Lie Transformation Group approach to visual pattern processing, Cartesian and polar stimuli represent different invariances in the visual world. This study compared Cartesian, polar and hybrid plaids as to their propensity to be perceived as coherently moving stimuli. Cartesian and polar plaids were similar in terms of the effects of intersection luminance and relative contrast on coherence, polar plaids being consistently less coherent. Hybrid plaids did not usually cohere at all. Adaptation to an unambiguously coherent plaid decreased perceived coherence when tested with a bistable plaid from the same, and not from the other Lie group, i.e. there was within-group adaptation but no between-group adaptation. Polar plaids also offer the possibility of studying the influence of another depth parameter on motion integration: expansion or contraction of circular gratings, which represent motion-in-depth toward or away from the observer. This motion-in-depth was tested for interaction with disparity or relative contrast in the determination of motion integration. The results were negative under the present conditions. Thus not all depth parameters contribute equally to the determination of the stimulus depth relations affecting the motion integration process.

The effect of disparity on motion coherence

Many moving plaid stimuli are ambiguous, and perception switches between a coherent plaid pattern and two transparent gratings. Here, experiments are reported that examined the effect of stereodepth between the two gratings of the moving plaid stimulus on the perception of coherence or motion transparency. Increasing disparity increased the percentage of time that two independently drifting transparent gratings were perceived. This was studied for plaids with various levels of intersection luminance. Using intersection luminances beyond conditions of physical transparency increased the percentage of time that one coherent plaid was seen. These two opposing influences could be pitted against each other to achieve constant levels of coherence. An adaptation paradigm was also used in which observers adapted to a stationary stimulus with either zero, crossed or uncrossed disparity between the gratings, and then indicated the occurrence of coherence and motion transparency in test stimuli of drifting plaids with zero, crossed or uncrossed disparity. Adaptation to crossed and uncrossed stereo-depth increased relative perceived coherence equally, especially for zero test disparity. An analysis of the length of the episodes of coherence and motion transparency indicated that the effect of adaptation was to decrease the length of motion transparency episodes, while the length of coherence episodes did not change. It is concluded that mechanisms involved in the processing of stereo-depth must have an input to the integration stage of the motion channel and that pattern and component motion mechanisms can operate quite independently.

Ambiguous plaids: switching between coherence and transparency

A plaid pattern consisting of two differently oriented moving gratings can be seen as two alternative percepts: transparency, in which the two gratings are seen to slide over each other in their respective directions, or coherence, in which one integrated pattern (the plaid) is seen to move in a new direction. With prolonged inspection, an observer switches between these two alternatives. It was found here that adaptation to unambiguous coherence reduces the time that coherence is seen with an ambiguous test stimulus. Similarly, adaptation to transparency reduces the time transparency is seen. Analysis of the duration of consecutive episodes revealed that the underlying processes are adapted independently. Control experiments confirmed that adaptation occurred to the coherent plaid and not to the intersections, and that this adaptation was not simply a directional motion aftereffect. It is concluded that switching occurs between motion processes at different cortical levels that can be adapted independently.

Comparing local and remote motion aftereffects

A new method, using phase-reversing sinusoidal gratings to cancel perceived motion, was developed to measure the motion aftereffect (MAE). This technique was used to show the existence of a remote MAE, i.e. an MAE in areas that were not directly stimulated during adaptation. In several experiments, this remote MAE was compared to the local MAE. The remote effect was generally weaker and of shorter duration. It showed no directional tuning within the investigated range, as compared to a tuning of +/- 60 deg of the local MAE. There was no adaptation effect to the component gratings of a plaid, indicating that the plaid was treated as a coherent pattern. The local MAE showed clear spatial frequency tuning, whereas the remote MAE varied little with spatial frequency difference, although there was a tendency towards frequencies lower than the adaptation frequency. The possibility is considered that both local and remote MAEs are generated in extrastriate areas.

Pouchitis and gastric hyposecretion: cause or effect?

Pouchitis is a well recognized entity but its aetiology is still controversial. The aim of this study is to determine if gastric acidity has a role in the physiopathology of this problem. In a series of 70 consecutive patients with pelvic reservoir (65 mucosal ulcerative colitis (UC), 5 familial adenomatous polyposis (FAP], 15 patients developed pouchitis. Ten patients responded favourably to metronidazole. Five patients had several episodes of resistant pouchitis. Two of these (with FAP) developed recurrent bouts of pouchitis while on cimetidine therapy for severe peptic disease. Both patients were improved on sucralfate and symptoms did not recur after highly selective vagotomy. The other three patients began to complain of pouchitis one to six years after the fabrication of the reservoir. Gastric studies were undertaken to determine the fasting gastric pH. The values were high in all three cases despite normal stimulation tests and normal gastric biopsy. After pouch removal for toxic dilatation (without obstruction) in one of these patients, the gastric pH returned to normal. From these preliminary results, it seems that pouchitis might be associated with hypochlorhydria. It might also be possible that certain physiologic properties of the reservoir reduce gastric acidity and so create recurrent bouts of pouchitis. Further studies are needed to evaluate the physiologic consequences of the pelvic ileal reservoir on gastric physiology.

Pyloromyotomy of Ramstedt: experience of a nonspecialized centre

In a general hospital over a period of 6 years 57 infants with congenital hypertrophic stenosis underwent a Ramstedt pylorotomy. In most cases a surgical resident-in-training performed the operation under the direct supervision of a general surgeon. There were no complications of anesthesia, no deaths and no substantial morbidity. The majority of infants left the hospital within 48 hours. The results in this series compared favourably with those reported from more specialized centres.

Dietary habits after ileal pouch-anal anastomosis

Dietary habits of patients who had undergone ileal pouch-anal anastomosis were assessed and correlated with bowel function. Twenty-four well-adapted patients (11 women, 13 men; mean age 32 years) voluntarily entered the study 30 +/- 4 months after closure of the diverting ileostomy. A standardized questionnaire on 108 food items and a 3-day food journal were used in the assessment. Twenty-one patients had no difficulty in selecting an appropriate diet. Caloric intake was adequate. Specific symptoms associated with several foods were as follows: increased stool frequency (beer, spirits, chinese food), decreased stool consistency (beer, wine, fried fish), perianal irritation (spicy foods), undigested particles (grapefruit, lettuce), odours (eggs). Pasta and bananas were associated with increased stool consistency. The authors believe that these observations may help in dietary counselling after ileal pouch-anal anastomosis.

Postoperative myocardial infarction and cardiac death. Predictive value of dipyridamole-thallium imaging and five clinical scoring systems based on multifactorial analysis

Sixty-six patients unable to complete a standard preoperative exercise test because of physical limitations were studied to determine the predictive value of individual clinical parameters, of clinical scoring systems based on multifactorial analysis, and of dipyridamole-thallium imaging before major general and vascular surgery. Study endpoints were limited to postoperative myocardial infarction or cardiac death before hospital discharge. There were nine postoperative cardiac events (seven deaths and two nonfatal infarctions). There was no statistical correlation between cardiac events and preoperative clinical descriptors, including individual clinical parameters, the Dripps-American Surgical Association score, the Goldman Cardiac Risk Index score, the Detsky Modified Cardiac Risk Index score, Eagle's clinical markers of low surgical risk, and the probability of postoperative events as determined by Cooperman's equation. There were no cardiac events in 30 patients with normal dipyridamole-thallium scans or in nine patients with fixed myocardial perfusion defects. Of 21 patients with reversible perfusion defects who underwent surgery, nine had a postoperative cardiac event (sensitivity, 100%; specificity, 43%). In the six other patients with reversible defects, preoperative angiography showed severe coronary disease or cardiomyopathy. Thus in patients unable to complete a standard exercise stress test, postoperative outcome cannot be predicted clinically before major general and vascular surgery, whereas dipyridamole-thallium imaging successfully identified all patients who sustained a postoperative cardiac event.

Chemically processed bovine heterografts of the second generation as arterial substitutes: a comparative evaluation of three commercial prostheses

The use of chemically processed bovine heterografts is primarily confined to the construction of arterio-venous blood accesses in those patients requiring hemodialysis, plasmapheresis or chemotherapy. The grafts of the first generation i.e. Artegraft and Solcograft are now being supplanted by those of the second generation i.e. Reinforced Artegraft, Solco P and NCGT. We have investigated these three types of arterial prostheses as a biomaterial in terms of sterility, inflammatory response and cytocompatibility and as a blood conduit in dogs in terms of patency and healing. For each type of graft, two implantations were carried out for durations of 4 hours, 24 hours, 48 hours, one week, two weeks, one month, three months, and six months. Therefore a total of 48 grafts were implanted. All grafts but five were patent at sacrifice: thromboses were observed in two Reinforced Artegraft (after two weeks and after one month) and in three NCGT (after 24 hours, after 48 hours, and after one month). Therefore the following patencies were observed: Reinforced Artegraft 14/16, Solco P 16/16 and NCGT 13/16. In all the patent grafts, the healing was reduced to the formation of a pannus along both anastomoses; thrombotic accumulations were observed on the surface defects of the grafts, particularly the NCGT graft. The Reinforced Artegraft presents only minor advantages over the previous Artegraft; the Solco P, somewhat more acceptable is no longer commercially available since the manufacturer withdrew it after early clinical failures. The improvements noted in the bovine heterografts of the second generation appear to be marginal as compared to those of the first generation.

Glycosylation at specific sites of erythropoietin is essential for biosynthesis, secretion, and biological function

The glycoprotein hormone erythropoietin (Ep), the primary regulator of erythropoiesis, is synthesized by the kidney and secreted as the mature protein with three N-linked and one O-linked oligosaccharide chains. To investigate the role(s) of each carbohydrate moiety in the biosynthesis and function of Ep, we have used oligonucleotide-directed mutagenesis of a cDNA for human Ep to alter the amino acids at each of the carbohydrate attachment sites. Each mutated cDNA construct was expressed in stably transfected sublines of a kidney cell line, baby hamster kidney. We show, by preventing attachment of N-linked carbohydrate at asparagines 38 or 83, or preventing O-linked glycosylation at serine 126, that glycosylation of each of these specific sites is critical for proper biosynthesis and secretion of Ep. Fractionation of cellular extracts demonstrated that the mutant proteins lacking glycosylation at each of these three sites, (38, 83, and 126) were associated mainly with membrane components or were degraded rapidly. Less than 10% of these three mutant proteins were processed properly and secreted from the cells. The Ep protein lacking N-linked glycosylation at asparagine 24 is synthesized and secreted as efficiently as native Ep. The carbohydrates at positions 24 and 38 may be involved in the biological activity of Ep, since the absence of either of the oligosaccharide side chains at these positions reduced the hormone's biological activity.

Cholinergic REM sleep induction by arecoline in normal subjects: relation to thyroid function

Serum thyroid hormones and the speed of rapid eye movement (REM) sleep induction by the central muscarinic agonist arecoline were measured in 21 normal volunteers. The arecoline-REM induction latencies had a modestly significant negative correlation with free thyroxine index. This finding is discussed in the light of observations in animal studies that thyroid hormones stimulate central cholinergic neuronal function.

Determining gastric contents during general anaesthesia: evaluation of two methods

Two methods used to measure the volume of gastric contents were evaluated in 24 supine anaesthetized adults. Methods compared were: (1) aspiration of stomach contents through a large, vented, multi-orificed gastric tube, and (2) indirect determination by a dye dilution method using polyethylene glycol (PEG) as the marker. The volumes determined by these methods (Vasp and Vpeg respectively) were compared to the total volume (Vtot) present in the stomach, determined by direct inspection of the gastric pouch by the surgeon at the beginning of surgery. The results show that the volume of aspirated gastric fluid, using this type of tube, is a very good estimate of the total volume of gastric residue. The PEG dilution method yields similar results. However, correlation between Vpeg and Vtot was not as close-fitting as the correlation between Vasp and Vtot. PEG dilution is more complicated, time-consuming and offers no advantage over aspiration.

Quantitative assessment of pelvic ileal reservoir emptying with a semisolid radionuclide enema. A correlation with clinical outcome

Fecal stasis in an ileal reservoir may lead to overgrowth of bacteria and changes in mucosal morphology that are of future concern. Moreover, improper evacuation may lead to increased stool frequency and reduced continence. The aims of this study were: to compare the functional results of two types of ileal reservoirs constructed with an ileoanal anastomosis, to compare their emptying to a normal rectum as assessed by a radionuclide enema, and to correlate functional results with emptying. The reservoirs were made of two (J) or three (S) limbs of terminal ileum. Thirty-three patients (16 with J-pouch and 17 with S-pouch) and ten healthy controls were included in the study. There was no difference in the mean age of patients or interval following diverting ileostomy closure. Functional results were obtained by written questionnaire assessing stool frequency, and soiling, use of medication, need for intubation, and episodes of pouchitis. Emptying was measured with instillation per anus of a semisolid medium labeled with 1.0 mCi of Tc-99. Ileal pouch counts were measured using a scintillation camera and computer before and after spontaneous evacuation. The emptying was defined as the difference in counts divided by preevacuation counts. The functional results were similar in the two groups. Nocturnal soiling occurred more frequently in the S-pouch group. Pouchitis occurred in seven patients. Emptying of the two types of reservoir was similar (J: 72 +/- 4%, S: 67 +/- 5%), but it was less efficient than a normal rectum (90 +/- 3%, P less than 0.004). No correlation was established between age, sex, number of stools, pouchitis, and the efficacy of emptying. The clinical outcome of two patients who emptied less than 30%, however, was greatly improved by intermittent intubation. In conclusion, a semisolid radionuclide enema can be useful to identify patients who would benefit from intubation. No persistent defect in emptying was detected in patients with pouchitis.

Toxic megacolon. An analysis of 70 cases

The clinical features and outcome of 70 patients treated for toxic megacolon between 1970 and 1984 in five university-affiliated hospitals were determined. There were 35 women and 35 men with a mean age of 39 +/- 0.2 years. Toxic megacolon occurred at the initial episode of colitis in 43 patients (61 percent). Only five patients had a specific colitis: salmonellosis, two; ischemic, two; and pseudomembranous, one. Of the 65 remaining patients with nonspecific colitis, six had to be operated on without delay because of peritonitis. In the remaining 59 patients, toxic megacolon was cured with intensive medical management in nine (15 percent), improved temporarily in 14 (24 percent), and remained unchanged in 36 (61 percent). The postoperative mortality rate was 11 percent for all patients (6/56), 4 percent for patients without perforation (2/50) compared with 27 percent for patients with perforation (4/15). None of the patients who underwent surgery within five days of medical treatment died. When toxic megacolon was complicated by hemorrhage (nine patients) or peritonitis (eight patients), the mortality rate increased to 33 percent and 27 percent, respectively. A one-stage proctocolectomy was performed in 19 patients (32 percent). Of 32 patients in whom the rectum was retained, successful restoration of continuity was possible in only seven (22 percent) within 12 months after surgery. In well-selected patients, a plea is made for rectal preservation to offer an alternative to permanent ileostomy.

Interface of panic and depression: clinical and sleep EEG correlates

Four groups of subjects were compared with respect to their clinical and demographic status and electroencephalographic (EEG) characteristics, namely: primary major depressive disorder (PRI MDD); panic disorder (Panic); "Mixed" group comprising patients meeting full syndromal criteria for MDD and panic occurring concomitantly; and normal controls. The "Mixed" (MDD + Panic) patients were characterized by earlier age of onset of psychiatric illness, longer duration of current episode, greater intensity of symptoms, higher impairment of functioning, increased miscellaneous psychopathology, and greater objective stress and anger. With respect to sleep EEG variables, PRI MDD patients were clearly different from the other three groups. The sleep profile of the "Mixed" group occupies an intermediate position between the "pure" Panic and MDD groups. Classification of the "Mixed" patients based on the discriminant function coefficients of the Schedule for Affective Disorders and Schizophrenia and sleep analysis of the "pure" groups (PRI MDD and Panic) reveals that some patients are classified as true PRI MDD while others are classified as falling somewhere along the PRI-MDD/Panic spectrum. The separation of the PRI MDD from Panic and Normals, however, is clear, suggesting that sleep can be successfully used as a physiological marker in the separation of these conditions.

The fate of human umbilical vein grafts as an infrarenal aortic substitute in monkeys

The literature contains conflicting reports about the potential value of the processed human umbilical vein graft as an arterial substitute. With a view to a better understanding of the ultimate fate of this device, a series of long-term implantation was undertaken with a nonhuman primate model. Dardik Biografts were implanted as an infrarenal aortic substitute in 13 monkeys. Nine were put to death following complications after post-operative periods ranging from 3 months to 3 years, while four animals remain alive. No calcification or lipid infiltration was found, presumably because the animals were healthy. The patency rate was poor because of complications associated with thrombotic deposits and thinning of the graft wall after implantation, which led to stenosis and fibrous hyperplasia along the anastomoses. The external polyester mesh was found to encourage external tissue proliferation, which could not prevent the graft from dilating since it contained neither elastin nor smooth muscle cells. Because the places where the graft had been damaged before or during processing were the sites of thrombotic accumulation and initial collagen degeneration, it is essential to use only defect-free material. As a consequence the long-term durability of this graft continues to be questioned.

Cholinergic REM induction response: separation of anxiety and depression

Five groups of subjects underwent EEG sleep recordings, arecoline rapid eye movement (REM) induction response testing, and Schedule for Affective Disorders and Schizophrenia (SADS) interview. Group I: 20 patients with primary major depressive disorder (MDD) (endogenous) without any coexisting anxiety disorder; Group II: 19 primary MDD (endogenous) patients with secondary panic, GAD, or phobic disorders; Group III: 18 patients with primary anxiety disorder without coexisting MDD; Group IV: 14 patients with primary anxiety plus secondary MDD; Group V: 26 normal controls. Modified Research Diagnostic Criteria (RDC) were used for diagnosis, based on the SADS interview. There was considerable overlap of SADS scaled scores between patient groups, which is consistent with a heterogeneous clinical presentation of depressive and anxiety states. REM latency was significantly shorter in patients with primary MDD (without anxiety) as compared with that in patients with primary anxiety (no MDD) and normals. Arecoline REM induction response time was significantly shorter in both primary affective groups (I and II) as compared with primary anxiety (no MDD) patients and normal controls. REM latency and arecoline REM induction time was not significantly different between the primary anxiety groups (III and IV) and normals. The study highlights the use of biological markers in differentiating between clinical syndromes confounded by mixed or overlapping phenomenology.

Propranolol in schizophrenia

1. 15 schizophrenic patients diagnosed according to criteria of I.C.D.-9 were treated with d1-propranolol in a 4 week open study. 2. A fixed dose schedule was followed and a maximum dose of 1920 mg/day was reached by day 17. 3. Results revealed a significant reduction in core schizophrenic symptoms of CPRS & BPRS starting between 1st and second weeks of therapy. Higher doses were well tolerated and serious bradycardia occurred only in 3 patients. 4. The implications of these results are discussed.