Failure of human rhombic lip differentiation underlies medulloblastoma formation

Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain^1-4. Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage^5-8. By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL^9,10. However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage^3,4. Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES⁺KI67⁺ unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB.

Report from the 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; 28-29 September 2018

The 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, 28-29 September 2018. This interactive multidisciplinary conference is attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancers. In addition, invited speakers from other provinces participate. Surgical, medical, and radiation oncologists, and allied health care professionals participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancers.

Report from the 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Winnipeg, Manitoba; 29-30 September 2017

The 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Winnipeg, Manitoba, 29-30 September 2017. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Post-admission outcomes of participants in the PARAMEDIC trial: A cluster randomised trial of mechanical or manual chest compressions

BACKGROUND

The PARAMEDIC cluster randomised trial evaluated the LUCAS mechanical chest compression device, and did not find evidence that use of mechanical chest compression led to an improvement in survival at 30 days. This paper reports patient outcomes from admission to hospital to 12 months after randomisation.

METHODS

Information about hospital length of stay and intensive care management was obtained through linkage with Hospital Episode Statistics and the Intensive Care National Audit and Research Centre. Patients surviving to hospital discharge were approached to complete questionnaires (SF-12v2, EQ-5D, MMSE, HADS and PTSD-CL) at 90days and 12 months. The study is registered with Current Controlled Trials, number ISRCTN08233942.

RESULTS

377 patients in the LUCAS arm and 658 patients in the manual chest compression were admitted to hospital. Hospital and intensive care length of stay were similar. Long term follow-up assessments were limited by poor response rates (53.7% at 3 months and 55.6% at 12 months). Follow-up rates were lower in those with worse neurological function. Among respondents, long term health related quality of life outcomes and emotional well-being was similar between groups. Cognitive function, measured by MMSE, was marginally lower in the LUCAS arm mean 26.9 (SD 3.7) compared to control mean 28.0 (SD 2.3), adjusted mean difference -1.5 (95% CI -2.6 to -0.4).

CONCLUSION

There were no clinically important differences identified in outcomes at long term follow-up between those allocated to the mechanical chest compression compared to those receiving manual chest compression.

Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.

Abstract P5-14-02: Clinical predictors of benefit from fulvestrant in advanced breast cancer: A meta-analysis of randomized controlled trials

Background: While fulvestrant is approved by the United Stated Food and Drug Administration as an alternate endocrine therapy for treatment of advanced breast cancer, data on its efficacy compared to other endocrine treatments are inconsistent. Clinical markers predictive of greater benefit from fulvestrant compared to the alternate endocrine agents have not been identified.

Methods: We searched the literature from inception to May, 2015 from MEDLINE, EMBASE, and major conference proceedings. We included randomized controlled trials that evaluated Fulvestrant compared to either tamoxifen or an AI. We collected the efficacy data reported as Time to Progression (TTP) or Progression Free Survival (PFS) on 7 distinct subgroup of patients from the RCTs defined by: age, time to cancer reoccurrence from primary diagnosis, presence of visceral metastasis, previous chemotherapy exposure, presence of measurable disease, hormone receptor status and, HER-2 status. Data on rates of occurrences of 9 most frequently reported adverse events were also collected from both arms of the studies. Data on both efficacy and toxicity were then weighted using generic inverse variance approach and pooled in a meta-analysis using RevMan 5.3 software.

Results: We identified 8 RCTs that fulfilled our criteria and involved 4,024 patients (2,032 on fulvestrant and 1,992 on control arms). TTP/PFS was the primary endpoint in 7 out of 8 RCTs and secondary endpoint in one. Compared to an AI or tamoxifen, there was a statistically significant improvement in TTP favoring fulvestrant in patients who had visceral metastasis [Hazards Ratio (HR) 0.86; 95% Confidence Interval (CI) 0.77 to 0.96, p<0.01], measurable disease [HR 0.74; 95% CI 0.58 to 0.93, p=0.01], and HER-2 overexpression [HR 0.43; 95% CI 0.27 to 0.70, p<0.001]. Similar effect sizes were observed in a sensitivity analysis excluding the trials of combinations of fulvestrant and AI in the experimental arm. Rates of occurrences of adverse events were similar between fulvestrant and other endocrine agents.

Conclusion: Patients with advanced breast cancer that have visceral disease, measurable disease, or HER-2 driven disease are likely to derive higher benefits from treatment with fulvestrant compared to tamoxifen or an AI. These results may have implications for selection of patients in the design of future clinical trials and to inform treatment decisions in clinical practice.

Citation Format: Niraula S, Pitz M, Gordon V, Grenier D, Amir E, Brandes L. Clinical predictors of benefit from fulvestrant in advanced breast cancer: A meta-analysis of randomized controlled trials. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-14-02.

Consensus statement: the 16th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; September 5-6, 2014

The 16th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, September 4-5, 2014. The Consensus Conference is an interactive, multidisciplinary event attended by health care professionals from across western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) involved in the care of gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Is knowledge and practice safer in England after the release of national guidance on the resuscitation of patients in mental health and learning disabilities?

This paper reports on the issue of resuscitation in mental health inpatient environments. It reviews the literature on national standards and best practice when emergency situations arise in mental health settings. The discussion on the best practice literature takes place alongside the reporting of a national evaluation of how National Patient Safety Agency improvement guidelines for the provision for life support, and resuscitation for mental health service users was effectively implemented across health-care providers in England. Methods used to establish the effective use of the guidelines include feedback from clinical staff and staff responsible for the implementation of the new national standards for resuscitation. Serious incident data were also compared prior to the release of the national guidelines and after the guideline release dates. This included looking at events around choking and cardiac/respiratory arrest in inpatient areas. There were five deaths post-implementation of the guidelines that were considered to have serious enough error associated with the resuscitation process. This was down from 18 prior to the release of the guidelines. However, our survey showed that despite organisations reporting 100% compliance with the implementation of the guidelines, around half of frontline clinical staff were not aware of them. Although our survey responses show a contradiction between organisational and clinical staff awareness, our analysis suggests a reduction in moderate and severe harm cases and of deaths. There is evidence of a reduction in the worst types of error resulting in death, albeit with small numbers. In 2008, the National Patient Safety Agency issued a Rapid Response Report (RRR) aimed at health-care organisations providing inpatient care for mental health and learning disability patients, requiring organisations to make proper provision for life support and resuscitation for these patients. This paper examines whether effective implementation of the RRR recommendations had occurred across health providers in England. The methods used in this paper are the following: (1) Questionnaires were distributed nationally to clinical staff and implementation leads; (2) A national comparison of the number and severity of pre- and post-RRR release-related incidents involving choking/cardiac/respiratory arrest in Mental Health and Learning Disabilities settings was conducted; (3) Organisational compliance with the patient safety alert for all National Health Service Organisations in England was measured. There were five deaths post-implementation of the RRR that were considered to have serious enough error associated with the resuscitation. This was down from 18 deaths pre the RRR release. Although our survey responses show a contradiction between organisational implementation and clinical staff awareness, our analysis suggests a reduction in moderate and severe harm cases and of deaths. There is evidence of a reduction in the worst types of error resulting in death, albeit with small numbers.

Exploring the relationship between ADHD symptoms and prison breaches of discipline amongst youths in four Scottish prisons

OBJECTIVE

To explore the relationship between attention deficit hyperactivity disorder (ADHD) symptoms (inattention, hyperactivity and impulsivity) and violent and non-violent prison breaches of discipline in incarcerated male youths aged 18-21 years.

STUDY DESIGN

A case-control study of 169 male youth offenders incarcerated in Scottish prisons and classified as 'symptomatic' or 'non-symptomatic' of inattentive and hyperactive/impulsive ADHD symptoms.

METHODS

ADHD symptoms were measured using the Conners' Adult ADHD Rating Scales-Self Report: Long Version, and prison breaches of discipline were gathered from the Scottish Prison Service's Prisoner Records System.

RESULTS

Youths who were symptomatic of Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) ADHD total symptoms had a significantly higher number of prison breaches of discipline than those who were non-symptomatic. Youths who were symptomatic of DSM-IV hyperactive/impulsive symptoms had a significantly higher number of violent and non-violent prison breaches of discipline than those who were non-symptomatic. However, no such significant difference was found between youths who were symptomatic and non-symptomatic of DSM-IV inattentive symptoms.

CONCLUSIONS

Young male offenders who are symptomatic of ADHD have a higher number of prison breaches of discipline. In particular, symptoms of hyperactivity/impulsivity are associated with breaches of both a violent and non-violent nature. Implications of such symptoms on rehabilitation and recidivism are discussed.

Single Stage versus Multi-staged Stent-assisted Endovascular Repair of Intracranial Aneurysms

BACKGROUND

Stent-assisted coiling of intracranial aneurysms is performed either as a single-stage or a multi-staged procedure. The objective of our study is to compare the complications between the in single-stage versus the multi-staged stent-assisted coiling of intracranial aneurysm.

METHODS

From January 2003 to January 2010, consecutive patients treated with intracranial stent for aneurysms were prospectively enrolled. Patients' demographics including cerebrovascular risk factors, aneurysms size and locations were collected. Technical and clinical complications as well as outcomes were measured. Data were analyzed retrospectively using SPSS software version 11.5.

RESULTS

87 patients (87 aneurysms) with a mean of 51.2 ± 13.6 years were treated with 90 intracranial (Neuroform 74, Enterprise 16) stents, single-stage 37 (42.5%) and multi-staged 50 (57.5%). Eight adverse events were observed without any mortality, 6 of which were in the single-stage group-rupture of aneurysm in 2, and thrombo-embolic events in 4. Both rupture occurred in basilar artery bifurcation aneurysms, required ventriculostomy and resuscitations. In single-stage, asymptomatic intra-operative stent thrombosis developed in one, symptomatic stent thrombosis in one on day 14, transient ischemic attack on day 6 and immediate post operative stroke in one. Only two minor strokes were observed in the multi-staged group, one on post-procedure day 7 and other on day 60. Majority of the patients had good outcomes including those with events.

CONCLUSION

Our study revealed that single-stage stent-coiling technique is associated with a higher rate of complications than multistaged procedure. Therefore, staging the procedure may be an option whenever possible.

Progressive occlusion of aneurysms in Neuroform Stent-assisted treatment of intracranial aneurysms

INTRODUCTION

The long term effect of Neuroform stent in progressive occlusion of intracranial aneurysms is not yet completely understood. Here the effect of the Neuroform stent in progressive occlusion of intracranial aneurysms and clinical outcome is reported.

METHODS

Consecutive patients treated with the Neuroform stent from January 2003 to July 2007 were prospectively enrolled. Patients' demographics, immediate and delayed rate of occlusion, and clinical outcomes using the National Institution of Health Stroke Scale (NIHSS) and the Glasgow Outcome Scale (GOS) were recorded.

RESULTS

Neuroform stent placement was attempted in 72 patients, including 10 ruptured cases. However, stent placement could not be accomplished in two patients who were not included for analysis. Mean age was 50 ± 14 years and mean aneurysm diameter was 10.28 ± 5.9 mm. Immediate complete occlusion was observed in 31 (44%), neck remnants in 29 (41%) and subtotal occlusion in 10 (14%). Angiographic follow-up was available in 59 cases; complete occlusion was observed in 48/59 (81%), neck remnant in 7/59 (13%) and recanalisation in 4/49 (7%). Of 39 patients with immediate incomplete obliteration, progressive complete occlusions were achieved in 25/31 (81%), no changes in two and recanalisation in four cases. The majority of patients had good outcomes (GOS 1 or NIHSS 0 in 66/70 (94%), GOS 2 or NIHSS 2 in one patient and GOS 3 or NIHSS 4 in three at the 90 day follow-up visit.

CONCLUSIONS

The Neuroform stent assisted neck remodelling technique improves progressive obliteration of intracranial aneurysms with a low recanalisation rate and good clinical outcome.

Prospective evaluation of somatic and autonomic small fibers in selected autonomic neuropathies

BACKGROUND

There are a number of distal and generalized small-fiber neuropathies. The neuropathologic basis is poorly understood as somatic and autonomic C fibers are not usually studied in the same region of the body.

OBJECTIVE

To evaluate prospective somatic and autonomic C-fiber function in 11 healthy control subjects and 38 patients with different clinical patterns of neuropathy.

METHODS

Distal small-fiber neuropathy (DSFN), peripheral neuropathy (PN), diabetic neuropathy (DN), neuropathic postural tachycardia syndrome (POTS), and idiopathic autonomic neuropathy (IAN) were evaluated. Intraepidermal nerve fiber density was used to evaluate distal somatic C fibers. Both quantitative sudomotor axon reflex test and skin norepinephrine content were measured for the biopsy site to assess distal autonomic C-fiber function. Postganglionic sudomotor, adrenergic, and cardiovagal functions were evaluated by autonomic reflex testing and quantified using a Composite Autonomic Severity Scale.

RESULTS

Skin norepinephrine concentration was significantly related to CASS. DN was associated with somatic and autonomic C-fiber impairment with good agreement. POTS was associated with selective distal autonomic deficit. DSFN had combined distal somatic and C-fiber impairment. IAN showed combined and selective distal and generalized autonomic C-fiber impairment. The somatic neuropathies had C-fiber impairment affecting both populations to varying degrees.

CONCLUSION

Although a general agreement exists between the loss of somatic C fibers and autonomic deficits, selective involvement occurs for specific autonomic neuropathies.

Long-term neuroprotective effect of inhibiting poly(ADP-ribose) polymerase in rats with middle cerebral artery occlusion using a behavioral assessment

Poly(ADP-ribose) polymerase (PARP) can initiate an energy-consuming and inefficient repair cycle following cerebral ischemia/reperfusion by transferring ADP ribose units to nuclear proteins eventually leading to cellular dysfunction and neuronal death. 3-Aminobenzamide (3-AB) is a selective inhibitor of PARP that can significantly reduce brain damage after focal ischemia in rats and displays a low toxicity in vivo. The goals of this study were to determine if inhibiting PARP with 3-AB has a long-term neuroprotective effect and if functional outcome improves in rats following focal ischemia and treatment with 3-AB. Focal ischemia was induced by a 2-h occlusion of the middle cerebral artery (MCA), using an intraluminal filament. Motor functions were evaluated from 5 to 28 days after reperfusion in four groups of rats: stroke without treatment; stroke treated with 3-AB at doses of 15 mg/kg, stroke treated with 3-AB at doses of 55 mg/kg; and the non-ischemic control rats. Functional behaviors were tested by a series of motor function tasks (foot placing, parallel bar crossing, rope and ladder climbing), as well as a neurological examination. Infarct volume of stroke brain in the same rat was determined by Nissl staining 28 days after surgery. Comparison of the untreated stroke group (n=11) and the treated stroke groups indicates that impairment of motor function was significantly (P<0.001) reduced by administration of 3-AB at doses of 15 mg/kg (n=9) or 55 mg/kg (n=10). Neurological outcome was also improved significantly (P<0.001). Infarct volume was significantly (P<0.01) reduced in both treated groups. Long-term neuroprotection following ischemia/reperfusion injury to the brain can be obtained by administration of a PARP inhibitor. The motor tests employed in this study can be used as sensitive, objective and reproducible measurements of functional impairment in rats following an ischemic stroke.

"Nurse, my head hurts": a review of childhood headaches

Headache, a frequent occurrence during childhood, can have a number of etiologies. Most headaches are benign, but all require appropriate assessment. Common types include sinusitis, migraine, and muscle contraction (tension). Headache assessment includes both history and physical examination. The headache history consists of the history of present illness, past history, family history, and environmental and social history. Physical examination begins with general observation and vital sign measurement and proceeds to specific inspection of the head, neck, and facial structures. The nursing interventions carried out are dependent on the interpretation of assessment findings. Pharmacologic interventions, commonly acetaminophen or ibuprofen, may be appropriate if pain management protocols exist. Nonpharmacologic strategies for headache relief include reassurance, rest, ingestion of simple and complex carbohydrate foods, relaxation exercises, or home care. Children with migraine headaches benefit from specific interventions, and children exhibiting headache warning signs should have emergency measures instituted.

Three-dimensional magnetic resonance angiography in the planning of aneurysm surgery

Standard planning for intracranial aneurysm surgery relies on the surgeon's intellectual reconstruction of the three-dimensional (3D) surgical field on the basis of a two-dimensional (2D) imaging modality, biplanar cerebral angiography. This method is relatively imprecise, and it relies on previous experience for optimal results. We describe a stereotactic magnetic resonance angiographic (MRA)-guided method based on computer segmentation techniques for the planning of aneurysm surgery that has the potential of bringing a 3D perspective to the lesion. The method has been evaluated retrospectively on 20 surgical patients in whom the aneurysm orientation and relationship to parent vessels were shown to match presurgical 3D stereotactic display. When it is adapted to frameless interactive surgical navigation, this method may become a useful adjunct in the surgical obliteration of these life-threatening lesions.

Stroke-specific FIM models in an urban population

Data from the Functional Independence Measure (FIM) are important outcome measures in the stroke population undergoing rehabilitation. The FIM consists of 18 scales scored from 1 to 7; higher numbers mean greater ability. Several different scores can be obtained from the FIM: a total score (sum of all the scales), individual scale scores, and a physical and cognitive score (a two-dimensional interpretation). Research has shown that FIM data can have multidimensional components. That implies different groupings of scales may exist and with this the possibility of developing more sophisticated and robust measures within stroke populations. This study examined the multidimensional aspects of FIM using an urban sample of ischemic and hemorrhagic stroke patients. We found a three-dimensional FIM solution for both stroke groups that included self-care, cognitive function, and toileting as the major grouping of scales. These findings confirm a multidimensional nature of FIM scores and show a condition-specific pattern of FIM scores in stroke patients. This knowledge will help nurses, clinicians, and researchers develop more sensitive ways of recording care outcomes; improved prediction of stroke outcomes may also emerge from this knowledge.

Agitation as a nursing-sensitive patient outcome in the neurologic patient population

Clinically, nursing has long recognized agitation as a significant patient problem. The adverse effects of agitation are well documented and include increased morbidity and mortality, patient self-injury, increased nursing resources, and increased length of stay. Agitation, however, can be influenced by the nursing care given, and alterations in levels of agitation can provide a measure for the effectiveness of nursing care to reduce agitation and prevent associated complications. This article presents a definition of agitation as a nursing-sensitive patient outcome in the neurologically impaired patient population. The author describes nursing interventions to prevent or reduce agitation, examines current tools to measure agitation, and offers recommendations for further research.

Serotonin infusions inhibit sensory input from the dural vasculature

Intravenous infusions of serotonin (5-hydroxtryptamine creatinine sulphate, 5HT, 50-300 microg/kg/min) in cats reversibly inhibited the responses of cervical spinal cord neurons to electrical stimulation of the superior sagittal sinus. Inhibition developed over 20-30 min and resolved over the same time course, suggesting a dependence on accumulation of 5HT in the central nervous system. Inhibition was suppressed by prior intravenous injection of the 5HT antagonists methysergide (1 mg/kg) and methiothepin (1 mg/kg). Infusions of 5HT (50 microg/kg/min) caused a rise in whole blood levels of 5HT by a factor of 1.5 of control values. 5HT levels in platelet-free plasma rose by a factor of 50. Levels of 5HT and 5 hydroxyindole acetic acid released into the cerebrospinal fluid rose significantly. The results suggest that earlier clinical observations that 5HT infusions can ameliorate the pain of migraine may not have been due to cranial vasoconstriction alone, but could have involved a central action of 5HT.

Surgical management of complex middle cerebral artery aneurysms

Complex middle cerebral artery (MCA) aneurysms are defined in this review as aneurysms larger than 20 mm, arising from the MCA bifurcation, and requiring unusual surgical approaches for their obliteration. The direct surgical approaches to complex MCA aneurysms can be divided into five techniques: 1) direct clipping, 2) trapping, 3) trapping and extracranial-intracranial anastomosis, 4) excision and end-to-end anastomosis, and 5) external wrapping. The pertinent surgical anatomy, preoperative preparation, intraoperative procedures, operative approaches, and potential complications will be reviewed.

Autoregulation in the middle meningeal artery

In cats anesthetized with alpha-chloralose, autoregulation of blood flow (F) in the middle meningeal and common carotid arteries was assessed by bleeding and subsequently reinfusing the animals to achieve a 25% step reduction in mean arterial blood pressure (P), while maintaining the systolic blood pressure >80 mmHg. The integrity of autoregulation was assessed by calculating the gain factor Gf = 1 - [(deltaF/F)/(deltaP/P)]. Cats were examined intact, after hexamethonium (10 mg/kg), and after papaverine (6 mg/kg). Reduction of blood pressure of 25 to 60 mmHg produced equivalent drops in carotid blood flow (Gf = 0.041 +/- 0.34; mean +/- standard deviation, n = 12). There were only small changes in flow in the middle meningeal artery during this procedure (Gf = 0.91 +/- 0.29). Hexamethonium did not block autoregulation in the middle meningeal artery (Gf = 0.92 +/- 0.13, n = 4). However, papaverine almost completely abolished the ability of the artery to autoregulate (Gf = 0.10 +/- 0.16, n = 7). The results suggest that the middle meningeal artery possesses an ability similar to that of the cortical circulation to autoregulate its blood flow through intrinsic, non-neuronal mechanisms. This will have important implications for the study of disturbances of dural arterial control in migraine and other headaches.

Reactions of the middle meningeal artery of the cat to neural and humoral stimulation

The physiology and pharmacology of the middle meningeal artery was investigated in cats in order to determine whether this artery was subject to normal neural and humoral control mechanisms. Carotid and middle meningeal arterial blood flows and resistances were measured in 16 cats anaesthetized with chloralose. The cervical sympathetic nerves were stimulated electrically. Stimulation of the cervical sympathetic nerves pre-ganglionically reduced blood flow in the middle meningeal artery by producing vasoconstriction in its resistance bed. The vasoconstriction was mediated via catecholamine-containing nerves, as it was abolished by prior intravenous administration of bretylium. Intravenous injections of noradrenaline or adrenaline also produced vasoconstriction in the middle meningeal arterial bed. 5-Hydroxytryptamine (5HT), on the other hand, produced a dilatation in the middle meningeal artery. We conclude that neurally or humorally released catecholamines can provide a plausible mechanism for vasoconstriction in the middle meningeal artery. The dilator effect of 5HT contrasts with the constrictor effect of the 5HT1-like receptor agonist sumatriptan and suggests a complex 5HT receptor pharmacology for the artery.

A social skills group for boys with Asperger's syndrome

A social skills group was conducted for 8 boys aged 8 to 12 years on a weekly basis for 14 sessions. In this descriptive paper we discuss the planning for the group, the teaching techniques used, the actual group process and a subjective assessment of outcomes. Possible directions for future interventions are also presented.

The development and evaluation of in vitro tests for photoirritancy

Photoirritancy, a reversible inflammatory reaction of the skin after chemical contact and UV radiation exposure, is increasingly observed as a side-effect of both cosmetics and certain systemic drugs. Despite the quantity of in vitro data available, none of the current animal models can be viewed as fully predictive of human exposure. It is therefore considered that the emphasis of future work should be the development and evaluation of in vitro assays. The aim of this study was to establish the interlaboratory performance of a physicochemical method, SOLATEX-PI. 12 pure chemicals at several concentrations were evaluated in the presence of UVA. In addition, a lymphoid cell assay was undertaken to allow a direct in vitro/in vitro comparison. The overall correlation between the laboratories was good when expressed in terms of a positive or negative result. However, there were some interlaboratory discrepancies, which were compounded by the lack of unequivocal in vivo data. Despite these discrepancies, both laboratories did agree on the final classification of nine of the 12 chemicals in the SOLATEX-PI system, based on the highest concentrations tested. The cellular photoirritancy assay, in contrast, predicted the correct classification for only eight of the 12 chemicals tested compared with the in vivo data supplied by IVI.

Assessment of chemical disinfectants against human immunodeficiency virus: overcoming the problem of cytotoxicity and the evaluation of selected actives

The aim of this study was to develop a standardised technique for assessing the virucidal activity of commercial disinfectants against human immunodeficiency virus (HIV). In the absence of any model procedure for HIV a protocol based on German DVV guidelines was developed. A major difficulty associated with such studies is the cytotoxic effect of the biocide on the target cells used in infectivity assays. This problem is most commonly overcome by dilution of the virus-disinfectant mixture, however, this requires high titre (> or = 10(7) TCID50) virus which is difficult to achieve with HIV. We employed a simple washing technique which effectively removed cytotoxicity while retaining infectivity. Incorporated into a standard suspension test, this method supported by virus isolation procedures was sensitive and reproducible. The reliability of the procedure was confirmed by evaluating the efficacy of some commercially available cidals which were known to be cytotoxic; namely two instrument disinfectants, Sactimed-I-Steril, an aldehyde based product, Sactimed-I-Sinald a guanide/quaternary-ammonium combination, and Levermed, an alcohol based hand disinfectant.

Preferential use of a T cell receptor V beta gene by acetylcholine receptor reactive T cells from myasthenia gravis-susceptible mice

Experimental autoimmune myasthenia gravis (EAMG) is an important model for testing current concepts in autoimmunity and novel immunotherapies for autoimmune diseases. The EAMG autoantigen, acethylcholine receptor (AChR), is structurally and immunologically complex, a potential obstacle to the application of therapeutic strategies aimed at oligoclonal T cell populations. Inasmuch as we had previously shown that the clonal heterogeneity of T cell epitope recognition in EAMG was unexpectedly limited, we examined TCR V beta expression. AChR primed lymph node T cells and established AChR reactive T cell clones from EAMG-susceptible C57BL/6 (B6; H-2b, Mls-1b) mice showed preferential utilization of the TCR V beta 6 segment of the TCR. After in vivo priming and in vitro restimulation for 7 days with AChR or a synthetic peptide bearing an immunodominant epitope, V beta 6 expressing lymph node cells (LNC) were expanded several-fold, accounting for up to 75% of recovered viable CD4+ cells. The LNC of B6.C-H-2bm12 (bm12; H-2bm12, Mls-1b) mice, which proliferated in response to AChR but not to the B6 immunodominant peptide, failed to expand V beta 6+ cells. Inasmuch as nonimmune bm12 and B6 animals had similar numbers of V beta 6+ LNC (4-5%), this suggested that structural requirements for TCR recognition of Ag/MHC complexes dictated V beta usage. Results concerning peptide reactivity and V beta 6 expression among T cells from (B6 x bm12)F1 animals also suggested that structure-function relationships, rather than negative selection or tolerance, accounted for the strain differences between B6 and bm12. To examine the potential effects of thymic negative selection of V beta 6+ cells on the T cell response to AChR, CB6F1 (H-2bxd, Mls-1b; V beta 6-expressing) and B6D2F1 (H-2bxd, Mls-1axb; V beta 6-deleting) strains were analyzed for AChR and peptide reactivity and V beta 6 expression. Both F1 strains responded well to AChR but the response of B6D2F1 mice to peptide was significantly reduced compared to CB6F1. Short and long term cultures of peptide-reactive B6D2F1 LNC showed no expansion of residual V beta 6+ cells, although similar cultures of CB6F1 LNC were composed of more than 60% V beta 6+ cells. The results from the F1 strains further indicated that the T cell repertoire for peptide was highly constrained and that non-V beta 6 expressing cells could only partially overcome Mls-mediated negative selection of V beta 6+ TCR capable of recognizing peptide.(ABSTRACT TRUNCATED AT 400 WORDS)

Preferential use of a T cell receptor V beta gene by acetylcholine receptor reactive T cells from myasthenia gravis-susceptible mice

Experimental autoimmune myasthenia gravis (EAMG) is an important model for testing current concepts in autoimmunity and novel immunotherapies for autoimmune diseases. The EAMG autoantigen, acethylcholine receptor (AChR), is structurally and immunologically complex, a potential obstacle to the application of therapeutic strategies aimed at oligoclonal T cell populations. Inasmuch as we had previously shown that the clonal heterogeneity of T cell epitope recognition in EAMG was unexpectedly limited, we examined TCR V beta expression. AChR primed lymph node T cells and established AChR reactive T cell clones from EAMG-susceptible C57BL/6 (B6; H-2b, Mls-1b) mice showed preferential utilization of the TCR V beta 6 segment of the TCR. After in vivo priming and in vitro restimulation for 7 days with AChR or a synthetic peptide bearing an immunodominant epitope, V beta 6 expressing lymph node cells (LNC) were expanded several-fold, accounting for up to 75% of recovered viable CD4+ cells. The LNC of B6.C-H-2bm12 (bm12; H-2bm12, Mls-1b) mice, which proliferated in response to AChR but not to the B6 immunodominant peptide, failed to expand V beta 6+ cells. Inasmuch as nonimmune bm12 and B6 animals had similar numbers of V beta 6+ LNC (4-5%), this suggested that structural requirements for TCR recognition of Ag/MHC complexes dictated V beta usage. Results concerning peptide reactivity and V beta 6 expression among T cells from (B6 x bm12)F1 animals also suggested that structure-function relationships, rather than negative selection or tolerance, accounted for the strain differences between B6 and bm12. To examine the potential effects of thymic negative selection of V beta 6+ cells on the T cell response to AChR, CB6F1 (H-2bxd, Mls-1b; V beta 6-expressing) and B6D2F1 (H-2bxd, Mls-1axb; V beta 6-deleting) strains were analyzed for AChR and peptide reactivity and V beta 6 expression. Both F1 strains responded well to AChR but the response of B6D2F1 mice to peptide was significantly reduced compared to CB6F1. Short and long term cultures of peptide-reactive B6D2F1 LNC showed no expansion of residual V beta 6+ cells, although similar cultures of CB6F1 LNC were composed of more than 60% V beta 6+ cells. The results from the F1 strains further indicated that the T cell repertoire for peptide was highly constrained and that non-V beta 6 expressing cells could only partially overcome Mls-mediated negative selection of V beta 6+ TCR capable of recognizing peptide.(ABSTRACT TRUNCATED AT 400 WORDS)

Teaching physical diagnosis in the nursing home: a prospective, controlled trial

STUDY OBJECTIVE

To investigate the suitability of the nursing home as a site for teaching physical diagnosis to second-year medical students.

DESIGN

Prospective comparison of teaching sessions in the nursing home to concurrent control sessions in acute care wards.

SETTING

Nursing Home Care Unit (NHCU) and acute care hospital wards of a Veterans Affairs Medical Center.

PATIENTS

Sessions with 38 NHCU patients and 68 hospital patients.

MEASUREMENTS AND MAIN RESULTS

Patient interviews and student questionnaires were used to obtain responses on a 1-10 scale (1 = poor, 10 = excellent). Patient responses were very favorable in both settings for overall quality of experience (mean score NHCU vs control: 8.8 vs 8.6) and willingness to participate again (8.4 vs 8.2). Student ratings showed no significant differences for patient attitude (7.4 vs 8.4) or quality of exam (7.2 vs 7.7) while quality of history (6.0 vs 7.6) and overall quality of session (7.6 vs 8.6) were rated higher (P less than 0.05) for the control sessions. Students rated both environments highly (8.6 vs 8.4) but reported that fewer NHCU sessions were interrupted (15% vs 25%) or disrupted by noise (6% vs 30%, P less than 0.005).

CONCLUSIONS

Advantages of the nursing home include readily available patients who view participation favorably, instructive physical findings, and a suitable environment. However, students rate the quality of the histories obtained there lower. This problem could be addressed by more careful patient selection and greater emphasis by course instructors on other goals of the history in addition to exploring the chief complaint.

Light chain restriction analysis of bone marrow plasma cells in patients with MGUS or 'solitary' plasmacytoma: diagnostic value and correlation with clinical course

Twenty-eight patients with a diagnosis of 'solitary' plasmacytoma or with gammopathy but with nondiagnostic morphologic examination of the bone marrow were investigated using a short-term bone marrow culture technique which enriched for the plasma cell fraction. The percentage of monotypic plasma cells in these plasma cell enriched cultures was correlated with the subsequent clinical course. The majority of patients with plasmacytoma and a significant number of those with gammopathy but with otherwise non-diagnostic investigations were found to have a monoclonal plasma cell component of greater than 20%. There was a significant correlation between the percentage of monoclonal plasma cells as detected by bone marrow culture and subsequent progression to disseminated myeloma. These results indicate that early bone marrow involvement can be detected by means of plasma cell culture prior to morphologic identification of marrow plasmacytosis and that short-term plasma cell culture distinguishes patients with early, low bulk myeloma from those with monoclonal gammopathy of uncertain significance (MGUS).

Quantitation of the monoclonal plasma cell component in bone marrow from patients with serum paraproteinemia and nondiagnostic marrow morphology

Twenty-one patients with serum monoclonal gammopathy but lacking acceptable morphological evidence of myelomatosis were studied with reference to the degree, if any, of monoclonal plasma cell expansion in aspirated marrow samples, enriched for plasma cells and analysed with respect to light chain distribution. Four of these patients had a biopsy-proven plasmacytoma of bone. Bone marrow aspirated from sites distant to the tumor showed clear evidence of infiltration by monoclonal plasma cells in two of the cases studied; the other two patients had normal results. Of the 17 other cases, 14 showed evidence of a monoclonal plasma cell component qualitatively concordant with the serum paraprotein as one would expect. These cases could be subdivided into those with myeloma (six cases) and those with monoclonal gammopathy of undetermined significance (eight cases) on the basis of conventional biochemical and radiological criteria. Three of the 17 patients, however, did not show evidence of monoclonal plasma cell infiltration, despite the presence of lytic lesions. It is important to recognize this minority group that simulates myeloma but that may well reflect alternative pathology that has not been identified.

Reactivity of the bronchial artery to 5-hydroxytryptamine

The activity of 5-hydroxytryptamine and its antagonism by the selective 5-HT2 serotonergic receptor antagonist, ketanserin, was tested on the bronchial arteries of three domestic species; bovine, equine and ovine. 5-hydroxytryptamine contracted the bronchial artery in the bovine (threshold: 1.0 X 10(-9) M), the equine (threshold: 1.0 X 10(-9) M) and ovine (threshold: 5.0 X 10(-9) M), dose-dependently. Ketanserin on the bronchial artery of the bovine (concentrations: 1.0 X 10(-9) M and 1.0 X 10(-8) M), equine (concentrations: 1.0 X 10(-10) M, 1.0 X 10(-9) M and 1.0 X 10(-8) M) and ovine (concentrations: 1.0 X 10(-10) M, 5.0 X 10(-10) M and 1.0 X 10(-9) M), significantly (p less than 0.05) shifted the concentration response curves to 5-hydroxytryptamine and caused a depression of the maximum at the higher concentrations. The data indicates the presence of 5-HT2 serotonergic receptors in the bronchial artery of these species. The depression may possibly be due to the antagonist's adrenolytic properties.

Inhibition of insulin receptor phosphorylation by indomethacin

Insulin stimulated phosphorylation of tyrosine residues by the insulin receptor kinase may be part of a signalling mechanism associated with insulin's action. We report that indomethacin inhibited the phosphorylation of the beta-subunit of the solubilized adipocyte insulin receptor. Indomethacin also inhibited several insulin-sensitive processes in intact rat adipocytes. Indomethacin (1 mM) inhibited basal phosphorylation of the beta-subunit of the solubilized insulin receptor by 60% and insulin-stimulated phosphorylation by 30%. In adipocytes, indomethacin inhibited basal 3-0-[methyl-14C]-methyl-D glucose transport by 50% (P less than 0.01), D-[6-14C]-glucose oxidation by 50% (P less than 0.01), D-[6-14C]-glucose conversion to lipid by 30% (P less than 0.01), and D-[1-14C]-glucose conversion to lipid by 60% (P less than 0.01). Similarly, indomethacin inhibited insulin-stimulated 3-0-[methyl-14C]-methyl-D-glucose transport by 75% (P less than 0.01), D-[6-14C]-glucose oxidation by 20% (P less than 0.05), D-[1-14C]-glucose oxidation by 35% (P less than 0.01), D-[6-14C] glucose conversion to lipid by 25% (P less than 0.01), and D-[1-14C] glucose conversion to lipid by 45% (P less than 0.01). In contrast, insulin binding to its receptor, basal D-[1-14C]-glucose oxidation and both basal and insulin-stimulated activation of glycogen synthase were unaffected by indomethacin. Thus, indomethacin partially inhibited autophosphorylation of the solubilized insulin receptor on tyrosine and partially inhibited some but not all of insulin's actions.(ABSTRACT TRUNCATED AT 250 WORDS)

Circular dichroic spectra of apolipoprotein E in model complexes and cholesterol-rich lipoproteins: lipid contribution

Lipid-free apolipoprotein E (apo E) and canine apo E HDLc, a cholesterol-rich lipoprotein containing apo E as the only apolipoprotein, show very different circular dichroism (CD) spectra. To determine the cause of the spectral difference, we estimated the CD contribution of phospholipid, cholesterol, and cholesteryl ester in liposomes and microemulsions. We prepared microemulsions, containing nearly equal amounts of egg phosphatidylcholine (PC) and cholesteryl oleate (mean diameter 320 A), by an injection technique. Both microemulsions and cholesterol-containing liposomes exhibit intense negative CD bands in the far-ultraviolet region. Lipids contribute about 20% of the spectral difference between apo E and apo E HDLc at 222 nm, and about 60% of the spectral difference at 208 nm. The remainder of the spectral difference is attributable to lipid-protein interaction corresponding to a 15-30% increase in helicity of apo E. CD analysis indicates that the helical content of apo E in apo E HDLc resembles that in the ternary complex apo E-PC-cholesterol (or apo E-PC-cholesteryl ester) more than that in the binary complex apo E-PC, suggesting that cholesterol affects the conformation of apo E. Our data indicate that in going from a lipid-free state to a lipid environment, apo E undergoes a random to helix transition, assuming the maximal helicity predicted from its primary structure.

Formation of cholesterol- and apoprotein E-enriched high density lipoproteins in vitro

The delivery of cholesterol to canine serum or plasma altered the distribution of cholesterol and apoproteins in subclasses of high density lipoproteins (HDL). In these experiments, two in vitro systems were employed. The first system used cholesterol-celite particles to deliver cholesterol to canine plasma during 4-h incubations. When the cholesterol distribution in the lipoproteins was analyzed by Geon-Pevikon electrophoresis, an increase in cholesterol content was found in the slower migrating subclasses of HDL (HDL1 and HDLc). A large increase in apoprotein E (apo-E) was also observed in the lipoproteins. Densitometric analysis of lipid-stained, 4 to 30% gradient acrylamide gels of canine plasma after incubation with cholesterol-celite revealed that the concentration of the major high density lipoproteins (HDL3) decreased, and the concentration of subclasses of HDL-with apo-E (HDL1 and HDLc) increased 2- to 5-fold. In the second system, cholesterol-loaded mouse peritoneal macrophages released cholesterol to HDL in an incubation medium containing 10 to 20% canine serum. The HDL1 and HDLc, which demonstrated slower electrophoretic mobility as determined by Geon-Pevikon block electrophoresis, became enriched in cholesterol and cholesteryl esters. Gradient gel electrophoresis showed substantial increases in these subclasses of HDL-with apo-E. The cholesterol-loaded mouse peritoneal macrophages synthesized and secreted apo-E into the medium. When L-[35S]methionine was used as a precursor, 65 to 90% of the 35S-labeled protein associated with the lipoproteins in the 1.02 to 1.09 density range was immunoprecipitated with antibody directed against rat apo-E. Gradient gel electrophoresis of density fractions demonstrated the presence of HDL1 and HDLc as the major lipoproteins. In addition, when canine 125I-HDL3 (primarily apo-A-I-containing HDL) were added to canine serum and incubated with cholesterol-loaded macrophages, the appearance of HDL1 and HDLc was associated with a marked increase in the 125I label in these newly formed, cholesteryl ester-rich lipoproteins. There was a corresponding marked reduction in the 125I-HDL3 in the serum. Similar results were observed using human HDL3 and human serum.