Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ): Rationale and Study Design of the Largest Global Prospective Cohort Study of Clinical High Risk for Psychosis

This article describes the rationale, aims, and methodology of the Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ). This is the largest international collaboration to date that will develop algorithms to predict trajectories and outcomes of individuals at clinical high risk (CHR) for psychosis and to advance the development and use of novel pharmacological interventions for CHR individuals. We present a description of the participating research networks and the data processing analysis and coordination center, their processes for data harmonization across 43 sites from 13 participating countries (recruitment across North America, Australia, Europe, Asia, and South America), data flow and quality assessment processes, data analyses, and the transfer of data to the National Institute of Mental Health (NIMH) Data Archive (NDA) for use by the research community. In an expected sample of approximately 2000 CHR individuals and 640 matched healthy controls, AMP SCZ will collect clinical, environmental, and cognitive data along with multimodal biomarkers, including neuroimaging, electrophysiology, fluid biospecimens, speech and facial expression samples, novel measures derived from digital health technologies including smartphone-based daily surveys, and passive sensing as well as actigraphy. The study will investigate a range of clinical outcomes over a 2-year period, including transition to psychosis, remission or persistence of CHR status, attenuated positive symptoms, persistent negative symptoms, mood and anxiety symptoms, and psychosocial functioning. The global reach of AMP SCZ and its harmonized innovative methods promise to catalyze the development of new treatments to address critical unmet clinical and public health needs in CHR individuals.

The self, neuroscience and psychosis study: Testing a neurophenomenological model of the onset of psychosis

AIM

Basic self disturbance is a putative core vulnerability marker of schizophrenia spectrum disorders. The primary aims of the Self, Neuroscience and Psychosis (SNAP) study are to: (1) empirically test a previously described neurophenomenological self-disturbance model of psychosis by examining the relationship between specific clinical, neurocognitive, and neurophysiological variables in UHR patients, and (2) develop a prediction model using these neurophenomenological disturbances for persistence or deterioration of UHR symptoms at 12-month follow-up.

METHODS

SNAP is a longitudinal observational study. Participants include 400 UHR individuals, 100 clinical controls with no attenuated psychotic symptoms, and 50 healthy controls. All participants complete baseline clinical and neurocognitive assessments and electroencephalography. The UHR sample are followed up for a total of 24 months, with clinical assessment completed every 6 months.

RESULTS

This paper presents the protocol of the SNAP study, including background rationale, aims and hypotheses, design, and assessment procedures.

CONCLUSIONS

The SNAP study will test whether neurophenomenological disturbances associated with basic self-disturbance predict persistence or intensification of UHR symptomatology over a 2-year follow up period, and how specific these disturbances are to a clinical population with attenuated psychotic symptoms. This may ultimately inform clinical care and pathoaetiological models of psychosis.

A protocol for the first episode psychosis outcome study (FEPOS): ≥15 year follow-up after treatment at the Early Psychosis Prevention and Intervention Centre, Melbourne, Australia

BACKGROUND

Specialist early intervention (SEI) service models are designed to treat symptoms, promote social and vocational recovery, prevent relapse, and resource and up-skill patients and their families. The benefits of SEI over the first few years have been demonstrated. While early recovery can be expected to translate to better long-term outcomes by analogy with other illnesses, there is limited evidence to support this from follow-up studies. The current study involves the long-term follow-up of a sub-set of first episode psychosis (FEP) patients, with a range of diagnoses, who were first treated at Orygen's Early Psychosis Prevention and Intervention Centre (EPPIC) between 1998 and 2000. The aim of this paper is to present the methodology for this follow-up study.

METHODS

Between January 1998 and December 2000, 786 patients between the ages of 15-29 years were treated at EPPIC, located in Melbourne, Australia. Our cohort consists of 661 people (82 were transferred/discharged and 43 were not diagnosed with a psychotic disorder at time of discharge). The 18-month treatment characteristics of this cohort have been extensively examined in the First Episode Psychosis Outcome Study (FEPOS). The ≥15 year outcomes of this cohort are being examined in this study, known as FEPOS15.

RESULTS

Participant follow-up is ongoing. In order to extend and assess broader outcomes of the cohort, data linkage with health-related databases will be conducted.

CONCLUSION

This study will provide a comprehensive evaluation of the long-term trajectory of psychotic disorders after treatment for FEP in a SEI service.

Effect of 3 Forms of Early Intervention for Young People With Borderline Personality Disorder: The MOBY Randomized Clinical Trial

Importance

Clinical trials have neither focused on early intervention for psychosocial impairment nor on the contribution of components of borderline personality disorder (BPD) treatment beyond individual psychotherapy.

Objective

To evaluate the effectiveness of 3 early interventions for BPD of differing complexity.

Design, Settings, and Participants

This single-blinded randomized clinical trial recruited young people between March 17, 2011, and September 30, 2015, into parallel groups. The study took place at 2 government-funded mental health services for young people in Melbourne, Australia. Inclusion criteria were age 15 to 25 years (inclusive), recent DSM-IV-TR BPD diagnosis, and never receiving evidence-based BPD treatment. A total of 139 participants were randomized (pool of 876; 70 declined, 667 excluded), balanced for sex, age, and depressive symptomatology. Data analysis completed May 2020.

Interventions

(1) The Helping Young People Early (HYPE) dedicated BPD service model for young people, combined with weekly cognitive analytic therapy (CAT); (2) HYPE combined with a weekly befriending psychotherapy control condition; and (3) a general youth mental health service (YMHS) model, combined with befriending. Therefore, the 3 treatment arms were HYPE + CAT, HYPE + befriending, and YMHS + befriending. Participants were randomly assigned both to 1 treatment arm (in a 1:1:1 ratio) and to a clinician.

Main Outcomes and Measures

Psychosocial functioning, measured with the Inventory of Interpersonal Problems Circumplex Version and the Social Adjustment Scale Self-report.

Results

One hundred twenty-eight participants (104 [81.3%] were female; mean [SD] age, 19.1 [2.8] years; HYPE + CAT: 40 [31.3%]; HYPE + befriending: 45 [35.2%]; YMHS + befriending: 43 [33.6%]) who provided postbaseline data were included in the intent-to-treat analysis. Regardless of group, from baseline to 12 months, there was a mean of 19.3% to 23.8% improvement in the primary outcomes and 40.7% to 52.7% for all secondary outcomes, except severity of substance use and client satisfaction. The latter remained high across all time points. Planned comparisons (YMHS + befriending vs HYPE; HYPE + CAT vs befriending) showed that neither the service model nor the psychotherapy intervention was associated with a superior rate of change in psychosocial functioning by the 12-month primary end point. The HYPE service model was superior to YMHS + befriending for treatment attendance (median [IQR], 22 [19] vs 3 [16] contacts; median duration, 200 [139.5] vs 94 [125] days) and treatment completion (44 of 92 [47.8%] vs 9 of 47 [19.2%]). HYPE + CAT was superior to befriending for treatment attendance (median [IQR], 12 [16.5] vs 3 [9.8] sessions) and treatment completion (24 of 46 [52.2%] vs 29 of 93 [31.2%]).

Conclusions and Relevance

In this randomized clinical trial of 3 interventions for young people with BPD, effective early intervention was not reliant on availability of specialist psychotherapy but did require youth-oriented clinical case management and psychiatric care. A dedicated early intervention BPD service model (HYPE), with or without individual psychotherapy, achieved greater treatment attendance and completion, making it more likely to meet service user, family, and community expectations of care.

Trial Registration

anzctr.org.au Identifier: ACTRN12610000100099.

A Comparison of Adolescent versus Young Adult Outpatients with First-Presentation Borderline Personality Disorder: Findings from the MOBY Randomized Controlled Trial

OBJECTIVE

The increasing focus on adolescent personality disorder has tended to ignore evidence of the developmental continuity of the period from puberty to young adulthood. This study aims to: (1) describe the characteristics of a sample of young people with borderline personality disorder (BPD) who had no previous history of evidence-based treatment for the disorder and (2) compare their characteristics by participant age group.

METHODS

One hundred and thirty-nine young people (15 to 25 years) with BPD, newly enrolled in the Monitoring Outcomes of BPD in Youth randomized controlled trial, completed semi-structured interview and self-report measures assessing demographic, clinical, and functional characteristics. Younger (aged 15 to 17 years; n = 64) and older (aged 18 to 25 years; n = 75) participants were compared on these same variables using t-tests, chi-square tests, and logistic regression.

RESULTS

Young outpatients with BPD had extensive and severe psychopathology and were functioning poorly. Adolescents and young adults with BPD showed substantial similarities on 20 key aspects of their presentation. Significant between-groups differences were observed in household makeup, treatment history, antisocial personality disorder, emotion dysregulation, substance use, age of commencement and extent of self-harm, and achievement of age-appropriate educational milestones. Adolescent BPD group membership was predicted by family composition and self-harm, whereas young adult BPD group membership was predicted by not achieving age-appropriate milestones, vocational disengagement, and emotion dysregulation. The final model explained 54% of the variance and correctly classified 80.2% of the sample by age.

CONCLUSIONS

Both adolescents and young adults with early stage BPD present with severe and often similar problems to one another, supporting developmental continuity across this age range. However, there are also meaningful differences in presentation, suggesting that pathways to care might differ by age and/or developmental stage. Detection and intervention for personality disorder should not be delayed until individuals reach 18 years of age.

Evaluation of a culturally sensitive social and emotional well-being program for Aboriginal and Torres Strait Islanders

OBJECTIVE

To evaluate Deadly Thinking, a social and emotional well-being promotion program targeted to remote and rural Aboriginal and Torres Strait Islander communities. Deadly Thinking aims to improve emotional health literacy, psychological well-being and attitudes towards associated help-seeking.

DESIGN

Participants completed pre/post-test evaluations via a brief self-report survey immediately before and after the Deadly Thinking workshop.

SETTING

Aboriginal and Torres Strait Islander communities in rural and regional Australia.

PARTICIPANTS

Data were obtained from 413 participants (69.8% female, mean age 41.6 years), of whom 70.4% identified as Aboriginal or Torres Strait Islanders.

INTERVENTION

Deadly Thinking workshops involve participant's engaging with a series of videos and facilitated group discussions with other participants related to social and emotional well-being topics relevant to individuals and communities.

MAIN OUTCOME MEASURES

Participants completed measures of psychological distress, suicidal ideation, substance use, changes in attitudes towards help-seeking and help-seeking intentions and satisfaction with the workshop. Additionally, participants in a train-the-trainer workshop rated their perceived confidence to deliver the program post-workshop.

RESULT

Participants reported positive perceptions of community safety and well-being and low rates of marked distress, with no significant difference between train-the-trainer and community workshop participants. Results indicated significant improvement in help-seeking intentions post-workshop and high rates of satisfaction with workshop components.

CONCLUSION

Initial evaluation indicates good acceptability and feasibility of delivering the Deadly Thinking program in rural and remote Indigenous communities; however, more robust evaluation of the program is warranted using controlled conditions to measure effectiveness, particularly for changing in help-seeking behaviour.

Aripiprazole compared with placebo for auditory verbal hallucinations in youth with borderline personality disorder: Protocol for the VERBATIM randomized controlled trial

AIM

Up to half of patients with borderline personality disorder report auditory verbal hallucinations that are phenomenologically indistinguishable from those in schizophrenia, occur early in the course of the disorder, and are enduring, distressing and disabling. In clinical practice, this symptom is widely assumed to be unresponsive to treatment with antipsychotic medication and early intervention is rarely offered. The Verbal Experiences Response in Borderline personality disorder to Aripiprazole TrIal Medication (VERBATIM) study aims to be the first controlled trial to investigate the effectiveness of conventional pharmacotherapy for this symptom in this patient group.

METHOD

VERBATIM is a 12-week, triple-blind, single-centre, parallel groups randomised controlled trial, with a 27-week follow-up period. Participants between the ages of 15 and 25 years receive either aripiprazole or placebo daily, commencing at 2 mg and increasing to 10 mg by day 15. Further dose escalations (up to 30 mg) may occur, as clinically indicated. This trial was prospectively registered with the Australian and New Zealand Clinical Trials Registry ACTRN12616001192471 on 30/08/2016.

RESULTS

The primary outcome is severity of auditory verbal hallucinations assessed using the Psychotic Symptom Rating Scale. Secondary outcomes include the severity of general psychopathology, borderline personality pathology, social and occupational functioning and change in brain resting state connectivity. The primary endpoint is week 12 and secondary endpoint is week 39.

CONCLUSION

The results will inform treatment decisions for individuals with borderline personality disorder who present with auditory verbal hallucinations.

A psychoeducational group intervention for family and friends of youth with borderline personality disorder features: protocol for a randomised controlled trial

BACKGROUND

Caring for a person with borderline personality disorder is associated with poor outcomes including elevated psychological distress and burden. This study will compare the effectiveness of two brief psychoeducational programs for carers of youth presenting for early intervention for borderline personality disorder features. The protocol for this study is presented here.

METHODS

The study is a single-centre parallel group, randomised controlled trial. As a family unit, relatives, partners and friends ('carers') are randomly allocated to one of two treatment arms to receive either an online borderline personality disorder psychoeducation program, or both the online psychoeducation group and a face-to-face group program, Making Sense of Borderline Personality Disorder. Carers are assessed at baseline and follow-up (4 weeks after the intervention). It is expected that participants who received the combined group and online programs will have better outcomes than those who received the online program alone. The primary outcome is carer burden, assessed using the negative appraisal subscales of the Experience of Caregiving Inventory. Secondary outcomes include positive experiences of caregiving, coping, self-rated personality disorder knowledge, psychological distress, expressed emotion and quality of life.

DISCUSSION

This will be the first published evaluation of a psychoeducational intervention for carers of youth with borderline personality disorder features using a randomised controlled trial design. The results have the potential to inform clinicians and carers about the effectiveness of brief interventions designed to support families and friends of young people with borderline personality disorder, and what medium those interventions should utilise.

TRIAL REGISTRATION

Prospectively registered with the Australian New Zealand Clinical Trial Registry ACTRN12616000304437 on 08 March 2016.

Help seeking in older Asian people with dementia in Melbourne: using the Cultural Exchange Model to explore barriers and enablers

The prevalence of dementia is increasing in Australia. Limited research is available on access to Cognitive Dementia and Memory Services (CDAMS) for people with dementia from Culturally and Linguistically Diverse (CALD) communities. This study aimed to determine the barriers and enablers to accessing CDAMS for people with dementia and their families of Chinese and Vietnamese backgrounds. Consultations with community members, community workers and health professionals were conducted using the "Cultural Exchange Model" framework. For carers, barriers to accessing services included the complexity of the health system, lack of time, travel required to get to services, language barriers, interpreters and lack of knowledge of services. Similarly, community workers and health professionals identified language, interpreters, and community perceptions as key barriers to service access. Strategies to increase knowledge included providing information via radio, printed material and education in community group settings. The "Cultural Exchange Model" enabled engagement with and modification of the approaches to meet the needs of the targeted CALD communities.

Aged Care Assessment Service practitioners: a review of current practice for assessment of cognition of older people of culturally and linguistically diverse backgrounds in Victoria

AIM

This paper describes current practices and gaps identified by Aged Care Assessment Service (ACAS) clinicians in the assessment of cognition of clients of culturally and linguistically diverse (CALD) background in Victoria.

METHOD

A web-based survey, exploring practices and challenges faced by clinicians in assessing CALD clients and their families, was sent to all Victorian ACAS managers to distribute to their teams. Three focus groups were also conducted with ACAS clinicians to further explore these issues.

RESULTS

Seventy-nine web-based surveys were returned and 21 ACAS clinicians attended a focus group. Challenges reported included the availability and quality of interpreters, and variability in training received and confidence in assessing cognitive impairment in CALD clients.

CONCLUSION

ACAS clinicians reported that assessment of cognition for those of CALD background was challenging. Based on this feedback, practice tip sheets were developed as educational aids to assist ACAS staff.

Scoping the ethics of dementia research within an Australian human research context

Research with people with dementia can be ethically challenging because of the effects of dementia on cognitive function. A narrative literature review of ethical human dementia research was conducted, highlighting ethical challenges that can be categorised under the following themes: substitute judgment; how capacity can vary due to risks; barriers to recruiting people with dementia; how to determine capacity to give consent; and gaining assent rather than consent from participants. The results of the review were further analysed in relation to the Australian National Statement on Ethical Conduct in Human Research (National Statement). Gaps in the National Statement include: how capacity should be determined; what defines best interests; how assent and dissent by someone with dementia should be determined and respected; and whether or not people with dementia should be included in high-risk research.

Development and validation of an elbow score

OBJECTIVES

Few of the questionnaires available for evaluating the function and clinical state of the elbow have been validated. An ideal score would be consistent, sensitive, reliable and elbow-specific, incorporating both patient perception and clinician assessment. This was our aim.

METHODS

Items were generated using 25 patients and expert opinion, and reduced using 25 new patients to yield a nine-item patient questionnaire and a six-item clinical evaluation (of strength, motion and ulnar nerve involvement). This was validated using 63 new patients (of whom 28 were studied twice without therapy and 18 were studied again after appropriate surgery).

RESULTS

The test-retest reliability coefficient of determination (R2 = 0.93) and internal consistency (Cronbach's alpha = 0.98) were both good. Convergent validity was attested by good correlations with other scores, the Disabilities of Arm, Shoulder and Hand Questionnaire (DASH) and the Nottingham Health Profile (NHP) (physical) (R2 = 0.62 and 0.29, P < 0.0005). Sensitivity to change was demonstrated by correlating preoperative-postoperative changes to those in DASH and NHP (physical) (R2 = 0.50 and 0.27, P < 0.04).

CONCLUSION

This is a reliable, internally consistent score, correlating well with other, non-elbow specific scores and sensitive to change on treatment.

Motilin secretion and the migrating myoelectric complex in the pig

The concentration of motilin in plasma from the abdominal aorta and the hepatic portal vein and the net portal motilin output varied with the phase of the migrating myoelectric complex (m.m.c.) in five of six pigs fasted for 17 h. Maximum concentrations and output occurred 9-12 min before phase III in the duodenum or upper jejunum. In fed pigs m.m.c.s occurred and the first phase III in the duodenum occurred within 90 min of feeding. Both portal and arterial motilin concentrations were reduced after feeding and no longer varied with the phase of the m.m.c. Altered secretion of motilin after feeding did not appear to be associated with absorption of glucose as infusion of glucose (50 g/l, 10 ml/min) into the duodenum raised arterial and portal plasma glucose concentrations to post-prandial levels yet motilin concentrations and output rates still varied with the phase of the m.m.c. Infusions of motilin (1 or 10 ng/kg X min) into the portal vein of 17 h fasted pigs did not induce an extra phase III or alter the duration of the m.m.c. Hydrochloric acid (100 mmol/l) infused into the duodenum of fasted pigs at 10-21 ml/min increased the concentration of motilin in the portal blood but was without effect at 5 ml/min. Rapid injections of 50 ml hydrochloric acid into the duodenum also increased the portal motilin concentration. Hydrochloric acid infusion or injection did not alter the interval between phase IIIs. It is concluded that motilin secretion is a consequence of the m.m.c. or shows the same periodicity as the m.m.c. but that motilin is not an important factor in the initiation and control of the m.m.c. in the pig.

Small intestinal motility and transit by electromyography and radiology in the fasted and fed pig

The pattern of small intestinal digesta transit was studied in six young pigs (20-30 kg) by simultaneous electromyography and radiology. Pigs showed migrating myoelectric complexes (m.m.c.s) in the small intestine both when fasted and after feeding. The m.m.c.s were modified by feeding; quiescence was much reduced in duration and irregular spiking activity (i.s.a.) was prolonged; m.m.c.s were not disrupted and phases of regular spiking activity (r.s.a.) were still seen after feeding. The r.s.a. phase could be recognized on the screen and in spot films from both fasting and fed pigs as a band of intense rhythmic contractions pinching off the intestine and propelling all intestinal contents ahead of it. The r.s.a. moved caudad clearing the small intestine of digesta and leaving an empty quiescent intestine behind it. It was particularly characteristic in the fasted pig where it was usually associated with the progression of a gas bubble. The pattern of m.m.c.s in both fasted and fed animals along with the intermittent nature of stomach emptying, divided digesta into batches which progressed through the small intestine. Each batch--propelled by a m.m.c.--normally took 180-190 min to pass through the small intestine. M.m.c.s had a cycle length of 70-115 min in different parts of the small intestine. Usually two or three m.m.c.s and batches of intestinal contents were present in the small intestine at any one time. 22-33% of the m.m.c.s faded out in the proximal ileum. Batches of digesta propelled by these m.m.c.s had transit times increased by one m.m.c. duration and fused with the subsequent batch. Sometimes new m.m.c.s were generated in the terminal ileum. Two patterns of transport into the large intestine were seen. Usually digesta was transported by peristaltic rushes starting 100-200 cm from the ileo-caecal junction. The rush then continued through 1-1 1/2 turns of the spiral colon; occasionally the terminal ileum emptied by slow peristalsis. In this case there was no colonic rush and digesta went into the caecum.

The influence of intestinal infusion of fats on small intestinal motility and digesta transit in pigs

The influence of duodenal and ileal infusion of nutrients on small intestinal transit of digesta, measured by the passage of phenol red marker, was studied in twelve pigs fitted with duodenal and ileal catheters, and a terminal ileal cannula. Changes in gastrointestinal motility were observed by electromyography and by use of an X-ray image intensifier in four of the pigs fitted additionally with nichrome wire electrodes in the gut wall and in seven pigs fitted only with a gastric catheter. Small intestinal transit time was unaffected by intestinal catheterization per se, or by duodenal or ileal infusion of glucose or peptone. It was reduced by duodenal infusion of fat or of some of the products of fat digestion including oleic acid and a monoglyceride containing unsaturated fatty acids (monoglyceride LS) but was not affected by infusion of glycerol, stearic acid or a monoglyceride containing saturated fatty acids (monoglyceride P). Ileal transit time was greatly reduced by ileal infusion of soya bean oil mixed with bile salts and lipase and by monoglyceride LS but not by soya bean oil alone. Total small intestinal transit time was reduced to a lesser degree by ileal infusion of soya bean oil mixed with bile salts and lipase and by monoglyceride LS and was unaffected by soya bean oil alone. The level of irregular spiking activity of the small intestine was greatly reduced by both duodenal and ileal infusion of fat, but rapidly propagated spike bursts were initiated from the point of infusion (identified radiologically as peristaltic rushes) many of which travelled right through to the ileo-caecal junction. It is concluded that intestinal infusion of fat accelerates small intestinal transit in pigs by induction of peristaltic rushes; that since the ileal transit times were more severely reduced than total small intestinal transit times by ileal infusion of fat the response is probably only seen over those areas of intestine in direct contract with the fat; and that the effect depends upon the presence of fat digestion products, i.e. the fatty acid and the monoglyceride, although probably only those containing unsaturated fatty acids.

Effects of motilin, somatostatin, and pancreatic polypeptide on the migrating myoelectric complex in pig and dog

Spiking activity of the gastrointestinal tract was recorded in 4 fasted pigs and 4 fasted dogs during the intravenous infusion at two rates, 5 (rate A) and 20 (rate B) ng . kg-1 . min-1 of 13-Nle-motilin, somatostatin, and bovine pancreatic polypeptide. Infusions continued for 2 h in pigs and for 5 h in dogs. 13-Nle-Motilin was unable to induce a migrating myoelectric complex or to modify its frequency in the pig at either rate of infusion. In contrast, the infusion of 13-Nle-motilin at rate B in the dog induced a migrating myoelectric complex but delayed the occurrence of the following migrating myoelectric complex. However, the mean duration (74 +/- 22 min) of the migrating myoelectric complex interval in the 5 h of infusion did not significantly change compared with the control period (92 +/- 8 min). At rate B, somatostatin inhibited the gastroduodenal spiking activity in the pig and disrupted the migrating myoelectric complex pattern, whereas this hormone at both rates of infusion increased the frequency of the migrating myoelectric complex by 69.3% and 17.2%, respectively, in the dog. The infusion of bovine pancreatic polypeptide increased the frequency of the migrating myoelectric complex significantly by 36.4% and 82% at rates A and B in the pig and by 148% at rate A in the dog. Bovine pancreatic polypeptide also inhibited spiking activity in the duodenum but not in the jejunum at rate B in the dog. These results suggest that pancreatic polypeptide, but not somatostatin, may have a regulatory function on the rhythmicity of the migrating myoelectric complex in the dog and pig and that motilin does not control the occurrence of duodenal migrating myoelectric complex in the pig.

Initiation of the migrating myoelectric complex in dogs

1. Contractile and spike activity in the conscious dog were recorded from strain gauge force transducers and electrodes chronically implanted on the antrum, duodenum and jejunum. The pattern of activity was related to the time elapsed after feeding a daily meal, both in intact dogs and in dogs with antro-jejunal or oesophago-duodenal anastomoses. 2. From 8 to 10 h after feeding, transient reductions of the continuous antral spiking activity were recorded while phases of regular spiking activity (RSA) and contractions developed on the proximal intestine. 3. About 18 h after feeding, the post-prandial antral activity became intermittent, each period of contractions being accompanied by the duodenal development of a RSA phase. 4. The RSA phases were still initiated on the duodenum after an antro-jejunal anastomosis and after gastrectomy. 5. It is concluded that phases of RSA of the migrating myoelectric complex are initiated in the proximal part of the small intestine rather than in the stomach. It is suggested that the RSA phase exerts an inhibitory effect on the antrum which may serve to reduce the flow of digesta through the pylorus when the ability of the duodenum to receive chyme is restricted.

Insulin and myoelectric activity of the small intestine of the pig

The effect of insulin on the myoelectric activity of the small intestine was determined in conscious pigs. Animals were implanted with electrodes along the small intestine, a strain gage on the stomach and catheters in both saphenous arteries. Feeding modified the migrating myoelectric complex (MMC), a cyclic pattern of action potential activity of the small intestine characteristic of fasting. The first period of regular spiking activity (RSA) on the duodenum after feeding was delayed and was not followed by quiescence. Plasma insulin and glucose concentrations during the first three MMC after feeding were highest just before periods of duodenal RSA. Injection or infusion of insulin into fasted pigs with production of hypoglycemia caused disruption of stomach motility and duodenal electrical activity. The duodenal MMC was not altered when glucose to prevent hypoglycemia was infused together with insulin or when glucose was infused alone. These studies suggest that insulin is not directly responsible for the postprandial modification of MMC activity as insulin infusions only modify the MMC when hypoglycemia occurs.

Do the blood vessels of the antler velvet of the red deer have an adrenergic innervation?

Samples of antler velvet and pedicle skin of Red deer were snap-frozen, freeze-dried and treated with hot formaldehyde vapour. Sections (4 microns thick) were epi-illuminated with ultra-violet light. No blue-green fluorescence characteristic of adrenergic nerves was seen in sections from the antler velvet except in one castrate, although the blood vessels of the pedicle skin were well innervated. Yellow fluorescence characteristic of 5-hydroxytryptamine was present in mast cells in the velvet. The lack of a discrete adrenergic vasomotor innervation of the antler blood vessels makes it unlikely that antlers in velvet control heat loss by functioning as heat radiators.

Characteristics of the internal anal sphincter and the rectum of the vervet monkey

1. The physiology of the internal anal sphincter of the vervet monkey was investigated. 2. Strips of sphincter in vitro contracted to noradrenaline and adrenaline; adrenoceptors were mainly alpha-excitatory. Strips of rectal circular muscle relaxed to noradrenaline and contained both inhibitory alpha- and beta-adrenoceptors. 3. All strips contracted to acetylcholine. After hyoscine or atropine, high doses of acetylcholine relaxed all strips by stimulating intramural inhibitory neurones as relaxations were blocked by tetrodotoxin and hexamethonium. Nicotine and DMPP gave relaxations with similar characteristics. 4. It was concluded that relaxations to acetylcholine, nicotine and DMPP were not adrenergic as relaxations still occurred in strips from sympathetically denervated or reserpinized animals. The block of these relaxations by propranolol and guanethidine was considered to be unrelated to their actions as adrenergic blocking drugs. 5. All strips relaxed to field electrical stimulation (1--5 Hz) through stimulation of intramural inhibitory neurones as tetrodotoxin blocked these relaxations. Adrenergic blocking drugs, prior reserpinization or prior section of the hypogastric nerves did not block these responses. The relaxations were not therefore adrenergic. 6. 5-Hydroxytryptamine relaxed all strips but was not the transmitter in relaxations to acetylcholine, DMPP or nicotine, nor to field electrical stimulation, as desensitization of strips of 5-HT did not alter these responses. 7. The circular smooth muscle of the internal anal sphincter had a dense terminal adrenergic innervation which rapidly decreased orad. 8. In vivo, hypogastric nerve stimulation relaxed the rectum but contracted the sphincter. Sacral nerve root stimulation caused an after-contraction in both rectum and sphincter. In vivo, a close arterial injection of adrenaline or noradrenaline inhibited the spontaneous contraction waves of the rectum, but contracted the sphincter. Both these responses were blocked by phentolamine. 9. It was concluded that the internal anal sphincter is a discrete high pressure zone which was excitatory cholinergic and adrenergic innervations and an inhibitory non-adrenergic innervation.