A role for vessel-associated extracellular matrix proteins in multiple sclerosis pathology

Multiple sclerosis (MS) is unsurpassed for its clinical and pathological hetherogeneity, but the biological determinants of this variability are unknown. HLA-DRB1*15, the main genetic risk factor for MS, influences the severity and distribution of MS pathology. This study set out to unravel the molecular determinants of the heterogeneity of MS pathology in relation to HLA-DRB1*15 status. Shotgun proteomics from a discovery cohort of MS spinal cord samples segregated by HLA-DRB*15 status revealed overexpression of the extracellular matrix (ECM) proteins, biglycan, decorin, and prolargin in HLA-DRB*15-positive cases, adding to established literature on a role of ECM proteins in MS pathology that has heretofore lacked systematic pathological validation. These findings informed a neuropathological characterisation of these proteins in a large autopsy cohort of 41 MS cases (18 HLA-DRB1*15-positive and 23 HLA-DRB1*15-negative), and seven non-neurological controls on motor cortical, cervical and lumbar spinal cord tissue. Biglycan and decorin demonstrate a striking perivascular expression pattern in controls that is reduced in MS (-36.5%, p = 0.036 and - 24.7%, p = 0.039; respectively) in lesional and non-lesional areas. A concomitant increase in diffuse parenchymal accumulation of biglycan and decorin is seen in MS (p = 0.015 and p = 0.001, respectively), particularly in HLA-DRB1*15-positive cases (p = 0.007 and p = 0.046, respectively). Prolargin shows a faint parenchymal pattern in controls that is markedly increased in MS cases where a perivascular deposition pattern is observed (motor cortex +97.5%, p = 0.001; cervical cord +49.1%, p = 0.016). Our findings point to ECM proteins and the vascular interface playing a central role in MS pathology within and outside the plaque area. As ECM proteins are known potent pro-inflammatory molecules, their parenchymal accumulation may contribute to disease severity. This study brings to light novel factors that may contribute to the heterogeneity of the topographical variation of MS pathology.

Regional contribution of vascular dysfunction in white matter dementia: clinical and neuropathological insights

The maintenance of adequate blood supply and vascular integrity is fundamental to ensure cerebral function. A wide range of studies report vascular dysfunction in white matter dementias, a group of cerebral disorders characterized by substantial white matter damage in the brain leading to cognitive impairment. Despite recent advances in imaging, the contribution of vascular-specific regional alterations in white matter dementia has been not extensively reviewed. First, we present an overview of the main components of the vascular system involved in the maintenance of brain function, modulation of cerebral blood flow and integrity of the blood-brain barrier in the healthy brain and during aging. Second, we review the regional contribution of cerebral blood flow and blood-brain barrier disturbances in the pathogenesis of three distinct conditions: the archetypal white matter predominant neurocognitive dementia that is vascular dementia, a neuroinflammatory predominant disease (multiple sclerosis) and a neurodegenerative predominant disease (Alzheimer's). Finally, we then examine the shared landscape of vascular dysfunction in white matter dementia. By emphasizing the involvement of vascular dysfunction in the white matter, we put forward a hypothetical map of vascular dysfunction during disease-specific progression to guide future research aimed to improve diagnostics and facilitate the development of tailored therapies.

Posterior circulation ischaemic stroke diagnosis and management

This narrative review provides an overview of the posterior circulation and the clinical features of common posterior circulation stroke (PCS) syndromes in the posterior arterial territories and how to distinguish them from mimics. We outline the hyperacute management of patients with suspected PCS with emphasis on how to identify those who are likely to benefit from intervention based on imaging findings. Finally, we review advances in treatment options, including developments in endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT), and the principles of medical management and indications for neurosurgery. Observational and randomised clinical trial data have been equivocal regarding EVT in PCS, but more recent studies strongly support its efficacy. There have been concomitant advances in imaging of posterior stroke to guide optimal patient selection for thrombectomy. Recent evidence suggests that clinicians should have a heightened suspicion of posterior circulation events with the resultant implementation of timely, evidence-based management.

Cognitive decline and diabetes: a systematic review of the neuropathological correlates accounting for cognition at death

Given conflicting findings in epidemiologic studies, we determined the relative contributions of different neuropathologies to the excess risk of cognitive decline in diabetes mellitus (DM) through a systematic review of the literature. Included studies compared subjects with and without DM and reported neuropathological outcomes accounting for cognition at death. Data on Alzheimer's disease (AD) pathology, cerebrovascular disease and non-vascular, non-AD pathology were extracted from each study. Eleven studies (n=6 prospective cohorts, n=5 retrospective post-mortem series, total n=6330) met inclusion criteria. All 11 studies quantified AD changes and 10/11 measured cerebrovascular disease: macroscopic lesions (n=9), microinfarcts (n=8), cerebral amyloid angiopathy (CAA, n=7), lacunes (n=6), white matter disease (n=5), haemorrhages (n=4), microbleeds (n=1), hippocampal microvasculature (n=1). Other pathology was infrequently examined. No study reported increased AD pathology in DM, three studies showed a decrease (n=872) and four (n= 4018) showed no difference, after adjustment for cognition at death. No study reported reduced cerebrovascular pathology in DM. Three studies (n=2345) reported an increase in large infarcts, lacunes and microinfarcts. One study found lower cognitive scores in DM compared to non-DM subjects despite similar cerebrovascular and AD-pathology load suggesting contributions from other neuropathological processes. In conclusion, lack of an association between DM and AD-related neuropathology was consistent across studies, irrespective of methodology. In contrast to AD, DM was associated with increased large and small vessel disease. Data on other pathologies such as non-AD neurodegeneration, and blood-brain-barrier breakdown were lacking. Further studies evaluating relative contributions of different neuropathologies to the excess risk of DM are needed.

Equity for excellence in academic institutions: a manifesto for change

Higher academic institutions in the UK need to drive improvements in equity, diversity, and inclusion (EDI) through sustainable practical interventions. A broad view of inclusivity is based on an intersectional approach that considers race, geographical location, caring responsibilities, disability, neurodiversity, religion, and LGBTQIA+ identities. We describe the establishment of a diverse stakeholder group to develop practical grass-roots recommendations through which improvements can be advanced. We have developed a manifesto for change, comprising six domains through which academic institutions can drive progress through setting short, medium, and long-term priorities. Interventions will yield rewards in recruitment and retention of a diverse talent pool, leading to enhanced impact and output.

51 CT Head and Cervical Spine Audit in Patients Over the Age of 65: A District General Hospital Perspective

Introduction

Cervical spine (c-spine) injury has a high morbidity and mortality in patients over the age of 65; more than 60% result from falls from standing height (Beedham et al., 2019).

The Canadian Cervical Spine Rule (Stiell et al., 2001) deems that there is a high risk of c-spine fracture if any of the following apply:

The c-spine cannot be cleared clinically if the patient fits any of the above criteria. Imaging should be considered. As a result of recent clinical experiences Trust Guidelines at Stoke Mandeville Hospital now reflect this evidence (Hadley et al., 2019).

Methods

Fifty patients over the age of 65 who had a computerised tomography (CT) head scan in the Emergency Department (ED) following a traumatic head injury were randomly selected over a 1 month period. Cases were checked for examination of c-spine and/or CT c-spine. Results of the first cycle of the audit were presented at an ED Education Meeting. Indications for CT c-spine were displayed in poster format around the ED. Following these interventions, a re-audit was carried out using the same methodology.

Results

In fifty patients aged over 65 attending ED during one month, 16% had a CT c-spine in addition to a CT head. There was documented c-spine examination of 16% of those without CT c-spine on admission. In the re-audit 38% of the fifty patients who had a CT head underwent CT c-spine. In the group that did not have imaging of the c-spine, the proportion with documented cervical spine examination on admission remained the same (16%).

Conclusion

There was a 137.5% increase in the number of patients aged over 65 who appropriately underwent a CT c-spine as per Trust and National guidelines. Simple interventions (staff education and posters within the ED) were sufficient to significantly alter practice. Current trauma triage is not optimal for older patients who are reviewed by more junior doctors, less likely to be transferred to Major Trauma Centres and more likely to die than younger patients with similar injuries (Major Trauma In Older People 2017 Report). An older person’s trauma team in ED with age-appropriate triage would lead to appropriate imaging in a timely fashion, potentially improving the morbidity and mortality of these vulnerable patients.

Growth Differentiation Factor-11 Causes Neurotoxicity During Ischemia in vitro

Age-related neuronal dysfunction can be overcome by circulating factors present in young blood. Growth differentiation factor-11 (GDF-11), a systemic factor that declines with age, can reverse age-related dysfunction in brain, heart and skeletal muscle. Given that age increases susceptibility to stroke, we hypothesized that GDF-11 may be directly protective to neurons following ischemia. Primary cortical neurons were isolated from E18 Wistar rat embryos and cultured for 7-10 days. Neurons were deprived of oxygen and glucose (OGD) to simulate ischemia. Neuronal death was assessed by lactate dehydrogenase, propidium iodide or CellTox™ green cytotoxicity assays. 40 ng/mL GDF-11 administration during 2 h OGD significantly increased neuronal death following 24 h recovery. However, GDF-11 pre-treatment did not affect neuronal death during 2 h OGD. GDF-11 treatment during the 24 h recovery period after 2 h OGD also did not alter death. Real-time monitoring for 24 h revealed that by 2 h OGD, GDF-11 treatment had increased neuronal death which remained raised at 24 h. Co-treatment of 1 μM SB431542 (ALK4/5/7 receptor inhibitor) with GDF-11 prevented GDF-11 neurotoxicity after 2 h OGD and 24 h OGD. Transforming growth factor beta (TGFβ) did not increase neuronal death to the same extent as GDF-11 following OGD. GDF-11 neurotoxicity was also exhibited following neuronal exposure to hydrogen peroxide. These results reveal for the first time that GDF-11 is neurotoxic to primary neurons in the acute phase of simulated stroke through primarily ALK4 receptor signaling.

Rapamycin in ischemic stroke: Old drug, new tricks?

The significant morbidity that accompanies stroke makes it one of the world's most devastating neurological disorders. Currently, proven effective therapies have been limited to thrombolysis and thrombectomy. The window for the administration of these therapies is narrow, hampered by the necessity of rapidly imaging patients. A therapy that could extend this window by protecting neurons may improve outcome. Endogenous neuroprotection has been shown to be, in part, due to changes in mTOR signalling pathways and the instigation of productive autophagy. Inducing this effect pharmacologically could improve clinical outcomes. One such therapy already in use in transplant medicine is the mTOR inhibitor rapamycin. Recent evidence suggests that rapamycin is neuroprotective, not only via neuronal autophagy but also through its broader effects on other cells of the neurovascular unit. This review highlights the potential use of rapamycin as a multimodal therapy, acting on the blood-brain barrier, cerebral blood flow and inflammation, as well as directly on neurons. There is significant potential in applying this old drug in new ways to improve functional outcomes for patients after stroke.

The effect of rapamycin treatment on cerebral ischemia: A systematic review and meta-analysis of animal model studies

BACKGROUND

Amplifying endogenous neuroprotective mechanisms is a promising avenue for stroke therapy. One target is mammalian target of rapamycin (mTOR), a serine/threonine kinase regulating cell proliferation, cell survival, protein synthesis, and autophagy. Animal studies investigating the effect of rapamycin on mTOR inhibition following cerebral ischemia have shown conflicting results.

AIM

To conduct a systematic review and meta-analysis evaluating the effectiveness of rapamycin in reducing infarct volume in animal models of ischemic stroke.

SUMMARY OF REVIEW

Our search identified 328 publications. Seventeen publications met inclusion criteria (52 comparisons: 30 reported infarct size and 22 reported neurobehavioral score). Study quality was modest (median 4 of 9) with no evidence of publication bias. The point estimate for the effect of rapamycin was a 21.6% (95% CI, 7.6%-35.7% p < 0.01) improvement in infarct volume and 30.5% (95% CI 17.2%-43.8%, p < 0.0001) improvement in neuroscores. Effect sizes were greatest in studies using lower doses of rapamycin.

CONCLUSION

Low-dose rapamycin treatment may be an effective therapeutic option for stroke. Modest study quality means there is a potential risk of bias. We recommend further high-quality preclinical studies on rapamycin in stroke before progressing to clinical trials.

The role of the endoplasmic reticulum stress response following cerebral ischemia

Background Cornu ammonis 3 (CA3) hippocampal neurons are resistant to global ischemia, whereas cornu ammonis (CA1) 1 neurons are vulnerable. Hamartin expression in CA3 neurons mediates this endogenous resistance via productive autophagy. Neurons lacking hamartin demonstrate exacerbated endoplasmic reticulum stress and increased cell death. We investigated endoplasmic reticulum stress responses in CA1 and CA3 regions following global cerebral ischemia, and whether pharmacological modulation of endoplasmic reticulum stress or autophagy altered neuronal viability . Methods In vivo: male Wistar rats underwent sham or 10 min of transient global cerebral ischemia. CA1 and CA3 areas were microdissected and endoplasmic reticulum stress protein expression quantified at 3 h and 12 h of reperfusion. In vitro: primary neuronal cultures (E18 Wistar rat embryos) were exposed to 2 h of oxygen and glucose deprivation or normoxia in the presence of an endoplasmic reticulum stress inducer (thapsigargin or tunicamycin), an endoplasmic reticulum stress inhibitor (salubrinal or 4-phenylbutyric acid), an autophagy inducer ([4'-(N-diethylamino) butyl]-2-chlorophenoxazine (10-NCP)) or autophagy inhibitor (3-methyladenine). Results In vivo, decreased endoplasmic reticulum stress protein expression (phospho-eIF2α and ATF4) was observed at 3 h of reperfusion in CA3 neurons following ischemia, and increased in CA1 neurons at 12 h of reperfusion. In vitro, endoplasmic reticulum stress inducers and high doses of the endoplasmic reticulum stress inhibitors also increased cell death. Both induction and inhibition of autophagy also increased cell death. Conclusion Endoplasmic reticulum stress is associated with neuronal cell death following ischemia. Neither reduction of endoplasmic reticulum stress nor induction of autophagy demonstrated neuroprotection in vitro, highlighting their complex role in neuronal biology following ischemia.

The transient intraluminal filament middle cerebral artery occlusion model as a model of endovascular thrombectomy in stroke

The clinical relevance of the transient intraluminal filament model of middle cerebral artery occlusion (tMCAO) has been questioned due to distinct cerebral blood flow profiles upon reperfusion between tMCAO (abrupt reperfusion) and alteplase treatment (gradual reperfusion), resulting in differing pathophysiologies. Positive results from recent endovascular thrombectomy trials, where the occluding clot is mechanically removed, could revolutionize stroke treatment. The rapid cerebral blood flow restoration in both tMCAO and endovascular thrombectomy provides clinical relevance for this pre-clinical model. Any future clinical trials of neuroprotective agents as adjuncts to endovascular thrombectomy should consider tMCAO as the model of choice to determine pre-clinical efficacy.

A systematic review and meta-analysis of randomized controlled trials of endovascular thrombectomy compared with best medical treatment for acute ischemic stroke

BACKGROUND

Acute ischemic strokes involving occlusion of large vessels usually recanalize poorly following treatment with intravenous thrombolysis. Recent studies have shown higher recanalization and higher good outcome rates with endovascular therapy compared with best medical management alone. A systematic review and meta-analysis investigating the benefits of all randomized controlled trials of endovascular thrombectomy where at least 25% of patients were treated with a thrombectomy device for the treatment of acute ischemic stroke compared with best medical treatment have yet to be performed.

AIM

To perform a systematic review and a meta-analysis evaluating the effectiveness of endovascular thrombectomy compared with best medical care for treatment of acute ischemic stroke.

SUMMARY OF REVIEW

Our search identified 437 publications, from which eight studies (totaling 2423 patients) matched the inclusion criteria. Overall, endovascular thrombectomy was associated with improved functional outcomes (modified Rankin Scale 0-2) [odds ratio 1·56 (1·32-1·85), P < 0·00001]. There was a tendency toward decreased mortality [odds ratio 0·84 (0·67-1·05), P = 0·12], and symptomatic intracerebral hemorrhage was not increased [odds ratio 1·03 (0·71-1·49), P = 0·88] compared with best medical management alone. The odds ratio for a favorable functional outcome increased to 2·23 (1·77-2·81, P < 0·00001) when newer generation thrombectomy devices were used in greater than 50% of the cases in each trial.

CONCLUSIONS

There is clear evidence for improvement in functional independence with endovascular thrombectomy compared with standard medical care, suggesting that endovascular thrombectomy should be considered the standard effective treatment alongside thombolysis in eligible patients.

Reality of evidence-based practice in palliative care

There has been a paradigm shift in medicine away from tradition, anecdote and theoretical reasoning from the basic sciences towards evidence-based medicine (EBM). In palliative care however, statistically significant benefits may be marginal and may not be related to clinical meaningfulness. The typical treatment vs. placebo comparison necessitated by ‘gold standard’ randomised controlled trials (RCTs) is not necessarily applicable. The complex multimorbidity of end of life care involves considerations of the patient’s physical, psychological, social and spiritual needs. In addition, the field of palliative care covers a heterogeneous group of chronic and incurable diseases no longer limited to cancer. Adequate sample sizes can be difficult to achieve, reducing the power of studies and high attrition rates can result in inadequate follow up periods. This review uses examples of the management of cancer-related fatigue and death rattle (noisy breathing) to demonstrate the current state of EBM in palliative care. The future of EBM in palliative care needs to be as diverse as the patients who ultimately derive benefit. Non-RCT methodologies of equivalent quality, validity and size conducted by collaborative research networks using a ‘mixed methods approach’ are likely to pose the correct clinical questions and derive evidence-based yet clinically relevant outcomes.

Unexplained gastrointestinal symptoms: think mitochondrial disease

Defects in mitochondrial function are increasingly recognised as central to the pathogenesis of many diseases, both inherited and acquired. Many of these mitochondrial defects arise from abnormalities in mitochondrial DNA and can result in multisystem disease, with gastrointestinal involvement common. Moreover, mitochondrial disease may present with a range of non-specific symptoms, and thus can be easily misdiagnosed, or even considered to be non-organic. We describe the clinical, histopathological and genetic findings of six patients from three families with gastrointestinal manifestations of mitochondrial disease. In two of the patients, anorexia nervosa was considered as an initial diagnosis. These cases illustrate the challenges of both diagnosing and managing mitochondrial disease and highlight two important but poorly understood aspects, the clinical and the genetic. The pathophysiology of gastrointestinal involvement in mitochondrial disease is discussed and emerging treatments are described. Finally, we provide a checklist of investigations for the gastroenterologist when mitochondrial disease is suspected.

A method of inducing global cerebral ischemia

The four-vessel occlusion (4-VO) method of global forebrain cerebral ischemia mimics the human clinical condition of cardiac arrest. It results in selective neuronal damage and is a useful experimental system to dissect underlying mechanisms behind ischemic phenomena such as the differential susceptibility of CA1 compared to the CA3 region of the hippocampus. It also provides a "proof-of-principle" system for testing out potential agents for neuroprotection.

Transdermal fentanyl for cancer pain

BACKGROUND

Opioid drugs have been used for many years to relieve pain. Transdermal fentanyl offers one option for delivering and maintaining pain relief in patients with moderate or severe cancer pain.

OBJECTIVES

To determine the analgesic efficacy of transdermal fentanyl for relief of cancer pain, and to assess the adverse events associated with the use of transdermal fentanyl for relief of cancer pain.

SEARCH METHODS

The following databases were searched: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 4 of 12); MEDLINE (1966 to May 2013); EMBASE (1974 to May 2013; CANCERLIT (PubMED) (November 2012); and ClinicalTrials.gov (May 2013).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of transdermal fentanyl in adults and children with cancer pain. Studies with fewer than 10 participants were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two review authors. We extracted any available data on the number or proportion of patients with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales), together with information about adverse events and withdrawals.

MAIN RESULTS

We identified nine studies meeting the inclusion criteria, including a Turkish study that is awaiting formal translation. There were 1244 participants randomised in classically designed RCTs, of whom 1197 had evaluable data, and 138 patients enrolled in an enriched enrolment, randomised withdrawal (EERW) trial. Overall, 600 participants were treated with transdermal fentanyl patches, 382 with various formulations of morphine, 36 with methadone, and 221 with paracetamol plus codeine. There were major sources of potential bias, including lack of blinding, small size, high levels of attrition, and inconsistent reporting.We could not compare data in a meaningful analysis regarding adverse events such as nausea, abdominal pain, gastrointestinal bleeding, and confusion. These events may have been attributable to the underlying disease process.There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNT) for the analgesic effect. In seven studies with 461 participants reporting pain intensity results after about two weeks, the mean or median pain scores were on the borderline of mild and moderate pain. Most participants would have had no worse than mild pain on treatment. Another reported that 77% of participants using transdermal fentanyl had an undefined successful outcome. Fewer participants experienced constipation with transdermal fentanyl (28%) than with oral morphine (46%), giving a risk ratio of 0.61 (95% CI 0.47 to 0.78); the NNT to prevent constipation was 5.5 (95% CI 3.8 to 10).

AUTHORS' CONCLUSIONS

The randomised trial literature for effectiveness of transdermal fentanyl is limited, but it is an important medicine. Most studies recruited fewer than 100 participants and did not provide data appropriate for meta-analysis. Only a few reported how many patients had good pain relief but, where data were reported, a majority had no worse than mild pain within a reasonably short time period. The evidence pointed to a useful and significant reduction in complaints about constipation for transdermal fentanyl compared with oral morphine.

The exact science of stroke thrombolysis and the quiet art of patient selection

The science of metric-based patient stratification for intravenous thrombolysis, revolutionized by the landmark National Institute of Neurological Disorders and Stroke trial, has transformed acute ischaemic stroke therapy. Recanalization of an occluded artery produces tissue reperfusion that unequivocally improves outcome and function in patients with acute ischaemic stroke. Recanalization can be achieved mainly through intravenous thrombolysis, but other methods such as intra-arterial thrombolysis or mechanical thrombectomy can also be employed. Strict guidelines preclude many patients from being treated by intravenous thrombolysis due to the associated risks. The quiet art of informed patient selection by careful assessment of patient baseline factors and brain imaging could increase the number of eligible patients receiving intravenous thrombolysis. Outside of the existing eligibility criteria, patients may fall into therapeutic 'grey areas' and should be evaluated on a case by case basis. Important factors to consider include time of onset, age, and baseline blood glucose, blood pressure, stroke severity (as measured by National Institutes of Health Stroke Scale) and computer tomography changes (as measured by Alberta Stroke Programme Early Computed Tomography Score). Patients with traditional contraindications such as wake-up stroke, malignancy or dementia may have the potential to receive benefit from intravenous thrombolysis if they have favourable predictors of outcome from both clinical and imaging criteria. A proportion of patients experience complications or do not respond to intravenous thrombolysis. In these patients, other endovascular therapies or a combination of both may be used to provide benefit. Although an evidence-based approach to intravenous thrombolysis for acute ischaemic stroke is pivotal, it is imperative to examine those who might benefit outside of protocol-driven practice.

Endogenous neuroprotection: hamartin modulates an austere approach to staying alive in a recession

Tuberous sclerosis complex 1 (hamartin) is an effective endogenous neuroprotectant. Understanding the endogenous mechanism for neuroprotection mediated by hamartin may afford a novel approach to effective treatment of neurological diseases such as stroke, neurodegenerative diseases, and epilepsy, with possible applications to nonneurological conditions.

Suppression of the inflammatory response by diphenyleneiodonium after transient focal cerebral ischemia

Diphenyleneiodonium (DPI), a NADPH oxidase inhibitor, reduces production of reactive oxygen species (ROS) and confers neuroprotection to focal cerebral ischemia. Our objective was to investigate whether the neuroprotective action of DPI extends to averting the immune response. DPI-induced gene changes were analyzed by microarray analysis from rat brains subjected to 90 min of middle cerebral artery occlusion, treated with NaCl (ischemia), dimethylsulfoxide (DMSO), or DMSO and DPI (DPI), and reperfused for 48 h. The genomic expression profile was compared between groups using ingenuity pathway analysis at the pathway and network level. DPI selectively up-regulated 23 genes and down-regulated 75 genes more than twofold compared with both DMSO and ischemia. It significantly suppressed inducible nitric oxide synthase signaling and increased the expression of methionine adenosyltransferasesynthetase 2A and adenosylmethionine decarboxylase 1 genes, which are involved in increasing the production of the antioxidant glutathione. The most significantly affected gene network comprised genes implicated in the inflammatory response with an expression change indicating an overall suppression. Both integrin- and interleukin-17A-signaling pathways were also significantly associated and suppressed. In conclusion, the neuroprotective effects of DPI are mediated not only by suppressing ischemia-triggered oxidative stress but also by limiting leukocyte migration and infiltration.

A potential pathway for managing diabetic patients with arterial emboli detected by retinal screening

OBJECTIVE

The aim was to review a pathway of care for diabetic patients found to have retinal artery emboli detected by retinal screening.

DESIGN

This was a retrospective review of a pathway agreed in 2001 by a multidisciplinary team.

MATERIALS AND METHODS

The prospectively collected Gloucestershire Diabetic Retinal Screening Programme database was reviewed; patients sent for carotid duplex imaging underwent review of their scan results and their casenotes.

RESULTS

The prevalence of retinal emboli was 214 out of 25,299 diabetic patients who had retinal screening (0.85%). Some 200 diabetic patients underwent carotid duplex imaging; 23 had ipsilateral and 2 had contralateral carotid stenosis > 70%. Of these, ten patients underwent carotid endarterectomy without any major morbidity.

CONCLUSIONS

[corrected] A pathway was established for the small number of patients with retinal emboli, and could be tested in other populations.

Deficiency of Atf3, an adaptive-response gene, protects islets and ameliorates inflammation in a syngeneic mouse transplantation model

AIMS/HYPOTHESIS

Islet transplantation is a potential therapeutic option for type 1 diabetes. However, the need for multiple donors per patient and heavy immunosuppression of the recipients limit its use. The goal of this study was to test whether the gene encoding activating transcription factor 3 (ATF3), a stress-inducible pro-apoptotic gene, plays a role in graft rejection in islet transplantation.

METHODS

We compared wild-type (WT) and Atf3 knockout (KO) islets in vitro using stress paradigms relevant to islet transplantation: isolation, inflammation and hypoxia. We also compared the WT and KO islets in vivo using a syngeneic mouse transplantation model.

RESULTS

ATF3 was induced in all three stress paradigms and played a deleterious role in islet survival, as evidenced by the lower viability of WT islets compared with KO islets. ATF3 upregulated various downstream target genes in a stress-dependent manner. These target genes can be classified into two functional groups: (1) apoptosis (Noxa [also known as Pmaip1] and Bnip3), and (2) immunomodulation (Tnfalpha [also known as Tnf], Il-1beta [also known as Il1b], Il-6 [also known as Il6] and Ccl2 [also known as Mcp-1]). In vivo, Atf3 KO islets performed better than WT islets after transplantation, as evidenced by better glucose homeostasis in the recipients and the reduction of the following variables in the KO grafts: caspase 3 activation, macrophage infiltration and expression of the above apoptotic and immunomodulatory genes.

CONCLUSIONS/INTERPRETATION

ATF3 plays a role in islet graft rejection by contributing to islet cell death and inflammatory responses at the graft sites. Silencing the ATF3 gene may provide therapeutic benefits in islet transplantation.

Can observational studies provide a realistic alternative to randomized controlled trials in palliative care?

Evidence-based medicine demands 'gold standard' randomized controlled trials (RCTs). If strict criteria of quality, validity, and size are met, observational studies give the same result. Given the dearth of RCTs in palliative care, our aim was to identify good observational studies using PubMed searches and e-mail letters to experts in palliative care. The prior intention was provide the most comprehensive description possible to date of observational studies in palliative care, rather than to perform any statistical analyses. Three hundred and forty abstracts of study reports were identified, of which 27% (91) included > or = 200 subjects and 8% (27) > or = 1000 subjects. In reports with > or = 200 subjects, 51% included only cancer patients, and 42% included heterogeneous 'palliative care' patients. Prospective and retrospective studies accounted for 38% and 32% of all reports with > or = 200 subjects. In reports with > or = 1000 subjects, 59% were retrospective and 19% prospective. Patients had some input in 26% of studies with > or = 200 subjects, and 15% with > or = 1000 subjects. Only 12 prospective reports had one specific intervention. We found that palliative care is deficient not only in RCTs, but also good quality observational studies. Those that exist are extremely heterogeneous in subject, design, outcome reporting, and intervention.

How useful are systematic reviews for informing palliative care practice? Survey of 25 Cochrane systematic reviews

BACKGROUND

In contemporary medical research, randomised controlled trials are seen as the gold standard for establishing treatment effects where it is ethical and practical to conduct them. In palliative care such trials are often impractical, unethical, or extremely difficult, with multiple methodological problems. We review the utility of Cochrane reviews in informing palliative care practice.

METHODS

Published reviews in palliative care registered with the Cochrane Pain, Palliative and Supportive Care Group as of December 2007 were obtained from the Cochrane Database of Systematic Reviews, issue 1, 2008. We reviewed the quality and quantity of primary studies available for each review, assessed the quality of the review process, and judged the strength of the evidence presented. There was no prior intention to perform any statistical analyses.

RESULTS

25 published systematic reviews were identified. Numbers of included trials ranged from none to 54. Within each review, included trials were heterogeneous with respect to patients, interventions, and outcomes, and the number of patients contributing to any single analysis was generally much lower than the total included in the review. A variety of tools were used to assess trial quality; seven reviews did not use this information to exclude low quality studies, weight analyses, or perform sensitivity analysis for effect of low quality. Authors indicated that there were frequently major problems with the primary studies, individually or in aggregate. Our judgment was that the reviewing process was generally good in these reviews, and that conclusions were limited by the number, size, quality and validity of the primary studies.We judged the evidence about 23 of the 25 interventions to be weak. Two reviews had stronger evidence, but with limitations due to methodological heterogeneity or definition of outcomes. No review provided strong evidence of no effect.

CONCLUSION

Cochrane reviews in palliative care are well performed, but fail to provide good evidence for clinical practice because the primary studies are few in number, small, clinically heterogeneous, and of poor quality and external validity. They are useful in highlighting the weakness of the evidence base and problems in performing trials in palliative care.

Acute humoral rejection of renal allografts in CCR5(-/-) recipients

Increasing detection of acute humoral rejection (AHR) of renal allografts has generated the need for appropriate animal models to investigate underlying mechanisms. Murine recipients lacking the chemokine receptor CCR5 reject cardiac allografts with marked C3d deposition in the parenchymal capillaries and high serum donor-reactive antibody titers, features consistent with AHR. The rejection of MHC-mismatched renal allografts from A/J (H-2(a)) donors by B6.CCR5(-/-) (H-2(b)) recipients was investigated. A/J renal allografts survived longer than 100 days in wild-type C57BL/6 recipients with normal blood creatinine levels (28 +/- 7 micromol/L). All CCR5(-/-) recipients rejected renal allografts within 21 days posttransplant (mean 13.3 +/- 4 days) with elevated creatinine (90 +/- 31 micromol/L). The rejected allografts had neutrophil and macrophage margination and diffuse C3d deposition in peritubular capillaries, interstitial hemorrhage and edema, and glomerular fibrin deposition. Circulating donor-reactive antibody titers were 40-fold higher in B6.CCR5(-/-) versus wild-type recipients. Depletion of recipient CD8 T cells did not circumvent rejection of the renal allografts by CCR5-deficient recipients. In contrast, microMT(-/-)/CCR5(-/-) recipients, incapable of producing antibody, did not reject most renal allografts. Collectively, these results indicate the rapid rejection of renal allografts in CCR5(-/-) recipients with many histopathologic features observed during AHR of human renal allografts.

Imiquimod for Actinic Keratosis: Systematic Review and Meta-Analysis

Benefit and harm associated with treating actinic keratosis (AK) with the immune response modifier imiquimod was assessed using published randomized-controlled trials. Five randomized double-blind trials lasted 12-16 weeks and treated 1,293 patients. Complete clearance occurred in 50% of patients treated with imiquimod, compared to 5% treated with vehicle, and the number needed to treat (NNT) for one patient to have their keratosis completely cleared after 12-16 weeks was 2.2 (95% confidence interval 2.0-2.5). For partial (>/=75%) clearance the NNT was 1.8 (1.7-2.0). The proportion of patients with any adverse event, any local adverse event, or any treatment-related adverse event was substantially higher with imiquimod than with vehicle, and numbers needed to harm for one additional adverse event with imiquimod over 12-16 weeks ranged from 3.2 to 5.9. Particular local adverse events with imiquimod included erythema (27%), scabbing or crusting (21%), flaking (9%), erosion (6%), edema (4%), and weeping (3%). Imiquimod 5% cream was effective in the treatment of AK, preventing potential development of squamous cell carcinoma. Future investigation might be aimed at elucidating optimal dosing to minimize adverse events without detriment to efficacy, and evaluating long-term recurrence.

The safety and efficacy of the StarClose® vascular closure system: The ultrasound substudy of the CLIP study

BACKGROUND

The StarClose Vascular Closure System (Abbott Vascular, Redwood City, CA) features a nitinol clip that is designed to achieve closure of the femoral arteriotomy access site. The CLIP Study was performed to assess the safety and efficacy of StarClose when compared with standard manual compression following 5-6 French diagnostic or interventional percutaneous procedures. A substudy of this trial was designed to assess the utility of duplex ultrasonography to assess patency of the femoral artery and to determine access site complications (pseudoaneurysm, arteriovenous fistula, hematoma, deep vein thrombosis) in a multicenter prospective trial. This is the report of the duplex ultrasound (DUS) substudy of the CLIP trial.

METHODS

A total of 17 U.S. sites enrolled 596 subjects with 483 subjects randomized at a 2:1 ratio to receive StarClose or manual compression of the arteriotomy after a percutaneous procedure. The study included roll-in (n = 113), diagnostic (n = 208), and interventional (n = 275) arms with a primary safety endpoint of major vascular complications through 30 days and a primary efficacy endpoint of postprocedure time to hemostasis. A substudy of the CLIP interventional arm evaluated DUS images of the closure site at five study sites, targeting 100 subjects at day 30 following hemostasis. The DUS protocol was devised and implemented by an independent vascular ultrasound core laboratory with extensive experience in vascular device trials. DUS inguinal region from 6 cm proximal to 6 cm distal to the arteriotomy puncture was performed. A qualitative examination was performed to determine the presence of iatrogenic vascular injuries: hematoma, pseudoaneurysm (PSA), arteriovenous fistula (AVF), and arterial/venous thrombosis or stenosis using 2-dimensional gray scale, color, and focused Doppler images.

RESULTS

DUS of 96 subjects randomized to StarClose (n = 71) and compression (n = 25) were performed and evaluated. There was no evidence of hematoma, PSA, or AVF observed in the StarClose group. No StarClose subjects in the substudy had a PSA or AVF. All patients in the substudy demonstrated patency of the access site artery and vein without thrombosis or stenosis. Finally, in the entire study cohort, no clinically-driven DUS studies demonstrated iatrogenic vascular injury or vessel thrombosis in the StarClose treated patients.

CONCLUSION

DUS, a safe and reliable method for determining the safety and efficacy of access site closure devices, is a reliable, safe, inexpensive and accurate method of assessing vascular access site complications in multicenter trials. In this substudy of the CLIP study, DUS found no statistical difference in access site complications between the StarClose and manual compression groups. Both groups maintained vessel patency without stenosis, thrombosis, hematoma, pseudoaneurysm, or AV fistula.

Comparison of two methods for use in adaptive automation

Two psychophysiological adaptive automation methods were compared to assess their relative influence on teaching performance of 16 adults.

Inclusion of peripancreatic lymph node cells prevents recurrent autoimmune destruction of islet transplants: evidence of donor chimerism

BACKGROUND

Recurrent autoimmune beta-cell destruction may contribute to the poor results of clinical islet transplantation. Pancreas transplants from diabetes-resistant BB rats (BB-DR) are uniformly successful in autoimmune diabetic BB rats (BB-Ac), but isolated islets are destroyed, despite immunosuppression. In this study we tested the hypothesis that whole pancreas transplants abrogate autoimmunity by passive transfer to the host of an autoregulatory T-cell subset.

METHODS

BB-Ac rats served as recipients of BB-DR or Wistar Furth (WF) pancreas or islet transplants. Two cohorts of islet transplants included 50 or 100 x 10(6) peripancreatic lymph node cells (LNCs). Recipients were monitored for recurrent diabetes and subjected to fluorescence-activated cell sorter analysis of peripheral blood lymphocytes after 200 days by using monoclonal antibodies to class I, CD4, CD8, RT6.2, and RT6.1.

RESULTS

BB-DR pancreas transplants replete the RT6.1+ T-cell subset in BB-Ac rats, whereas BB-DR islet transplants, which are susceptible to recurrent autoimmunity, do not. Addition of 100 x 10(6) LNC results in repletion of RT6.1 to the same degree as the whole pancreas and leads to complete protection of the islets. WF pancreas transplants result in the appearance of RT6.2+ T cells in BB-Ac recipients, an RT allele that BB rats lack.

CONCLUSIONS

BB-Ac rat recipients of whole pancreatic or islets plus LNCs transplants become chimeric for a donor T-cell population that prevents recurrent autoimmune diabetes. Deliberate inclusion of donor lymphoid cells with clinical islet transplants may be beneficial.

Antiidiotypic antibodies to HLA class I alloantibodies in normal individuals: a mechanism of tolerance to noninherited maternal HLA antigens

Recent reports indicate that 25%-50% of transplant patients exhibit B-cell nonresponsiveness to their noninherited maternal HLA antigens (NIMAs). To test the hypothesis that tolerance of NIMAs is mediated by antiidiotypic antibodies, sera from seven normal human subjects were tested for the capacity to inhibit the reactivity of HLA alloantisera directed to NIMAs. Five of seven sera inhibited (50%-100%) the cytotoxicity of monospecific alloantisera directed to their NIMAs. This inhibition was specific in that antisera directed to third-party HLA antigens were not inhibited. Cytotoxicity inhibition by normal sera was selective for antisera directed to HLA-B locus antigens. Absorption with an antibody specific for an HLA class I framework determinant eliminated the inhibitory activity of three of the five sera, suggesting that the inhibition was mediated by soluble HLA antigens in these cases. However, two of the sera retained inhibitory activity following soluble antigen depletion, suggesting that, in these cases, inhibition is mediated by antiidiotypic antibodies. This hypothesis was confirmed by purifying the immunoglobulin (Ig) fraction of one of these sera by anti-Ig affinity chromatography; the column eluate (Ig fraction) but not the effluent (Ig-depleted serum) was capable of inhibition. These data are consistent with the hypothesis that tolerance of NIMAs is mediated, at least in part, by antiidiotypic antibodies.

Mesenchymal hamartoma of the liver. A report of 5 cases

Mesenchymal hamartoma of the liver is a rare benign tumour of childhood, characterised by an admixture of ductal structures within a copious loose connective tissue stroma. Less consistent features include hepatocytes and haemopoietic elements. The stroma has a propensity to accumulate fluid and to create macroscopic cystic spaces. Five cases are reported.

Functional and biochemical parameters of peptide antigen presentation

To understand the mechanism by which peptide antigens are processed and presented to T cells, we examined the T-cell response to the 13-amino-acid peptide alpha-melanocyte-stimulating hormone (alpha-MSH). To determine the fine specificity of T-cell recognition, T cells specific for alpha-MSH, and genetically restricted by I-Ab/d, were challenged with different alpha-MSH analogs and homologs. It was found that intact alpha-MSH, including the blocked amino and carboxy termini of the native molecule, was required for T-cell responsiveness. Antigen-presenting cells (APC) could be briefly pulsed with alpha-MSH and then present the alpha-MSH antigenic determinant to T cells, indicating that the relevant antigen was retained by the APC. APC stimulatory capacity was dramatically reduced by aldehyde treatment of the APC, or by pulsing the APC with alpha-MSH at low temperature. Efficient alpha-MSH pulsing was also impaired by treatment of the APC with the carboxylic ionophore, monensin, but not by the lysosomotropic agents chloroquine and methylamine. In addition, isolated APC plasma membranes added to the T cells in the presence of soluble alpha-MSH were not stimulatory. However, plasma membranes isolated from APC that had been previously pulsed with alpha-MSH retained stimulatory activity for T-cell responses. The only detectable alpha-MSH contained in these pulsed APC membranes was in an acid-stable complex of higher molecular weight than native peptide. The amount of alpha-MSH detected in the cellular membrane fraction isolated by density gradient sedimentation was also reduced by treatments that reduced the APC stimulatory capacity, such as pulsing at low temperature or in the presence of monensin. Taken together, these results suggest that processing of alpha-MSH is unlike that heretofore described for other peptide antigens and seems to involve APC handling to form the stimulatory moiety presented on the APC surface.

Fine structure of the host-fungus interface in orchid mycorrhiza

Electron microscopy of protocorms of Dactylorhiza purpurella infected with a symbiotic Rhizoctonia sp. showed that the intracellular hyphae examined did not penetrate the plasmalemma of the host cell. Walls of hyphae within cells bore many hemispherical protuberances over which the host plasmalemma was closely pressed. we estimate that these protuberances would increase the area of contact between hyphae and host plasmalemma by about 15%. They were not found on hyphae growing on agar. Except for these protuberances, and some vesicles or tubules which invaginated the fungus plasmalemma, no other structures were seen which could be suggested to be adaptations to transport across the living fungus-host interface.