Diagnostic accuracy and clinical impact of natriuretic peptide screening for the detection of heart failure in the community: a protocol for systematic review and meta-analysis

Introduction: Patients diagnosed with heart failure in primary care have a better prognosis than those diagnosed in hospital. However, most cases are missed in the community. Recent attention has focussed on the potential of early detection through screening. Natriuretic peptides (NPs) are tested by GPs and used to rule out heart failure in patients presenting with symptoms. Evidence is now emerging that they may also have a role in screening but their accuracy in this context and the associated optimal thresholds, have not been established. The impact that NP screening would have on patients and health care systems also remains unclear. Methods: We aim to undertake a systematic search of the following sources: Ovid Medline, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. Screening, data extraction and critical appraisal will be carried out independently and in duplicate by two reviewers. We will include studies based in the community with >100 participants that recruited a screened population. We will not add a study design filter and there will be no language restriction. The primary outcome will be the sensitivity and the specificity of NP screening and optimal thresholds for screening will be explored. Outcomes of interest for the impact analysis will include mortality, hospital admissions and cost effectiveness. This protocol has been developed in accordance with guidelines from the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P). Discussion: This systematic review will identify how accurately NP screen for heart failure in the community and explore where NP screening thresholds should be set. It also aims to summarise the clinical impact of this strategy. Together, these results should inform future interventions that may provide an alternative pathway to facilitate improved detection of heart failure in the community. Registration: PROSPERO CRD42018087498; registered on 11 May 2018.

Diagnostic accuracy and clinical impact of natriuretic peptide screening for the detection of heart failure in the community: a protocol for systematic review and meta-analysis

Introduction: Patients diagnosed with heart failure in primary care have a better prognosis than those diagnosed in hospital. However, most cases are missed in the community. Recent attention has focussed on the potential of early detection through screening. Natriuretic peptides (NPs) are tested by GPs and used to rule out heart failure in patients presenting with symptoms. Evidence is now emerging that they may also have a role in screening but their accuracy in this context and the associated optimal thresholds, have not been established. The impact that NP screening would have on patients and health care systems also remains unclear. Methods: We aim to undertake a systematic search of the following sources: Ovid Medline, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. Screening, data extraction and critical appraisal will be carried out independently and in duplicate by two reviewers. We will include studies based in the community with >100 participants that recruited a screened population. We will not add a study design filter and there will be no language restriction. The primary outcome will be the sensitivity and the specificity of NP screening and optimal thresholds for screening will be explored. Outcomes of interest for the impact analysis will include mortality, hospital admissions and cost effectiveness. This protocol has been developed in accordance with guidelines from the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P). Discussion: This systematic review will identify how accurately NP screen for heart failure in the community and explore where NP screening thresholds should be set. It also aims to summarise the clinical impact of this strategy. Together, these results should inform future interventions that may provide an alternative pathway to facilitate improved detection of heart failure in the community. Registration: PROSPERO CRD42018087498; registered on 11 May 2018.

The potential of recycled materials used in agriculture to contaminate food through uptake by livestock

The potential for contaminant uptake from recycled materials used in livestock farming, to animal tissues and organs, was investigated in three practical modular studies involving broiler chickens, laying chickens and pigs. Six types of commercially available recycled materials were used either as bedding material for chickens or as fertilizer for cropland that later housed outdoor reared pigs. The contaminants studied included regulated contaminants e.g. polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins) and polychlorinated biphenyls (PCBs), but related contaminants such as polybrominated diphenylethers (PBDEs), hexabrominated cyclododecane (HBCDD), polychlorinated naphthalenes (PCNs), polybrominated dioxins (PBDD/Fs) and perfluoroalkyl substances (PFAS) were also investigated. Contaminant occurrence in the recycled materials was verified prior to the studies and the relationship to tissue and egg concentrations in market ready animals was investigated using a weights of evidence approach. Contaminant uptake to animal tissues and eggs was observed in all the studies but the extent varied depending on the species and the recycled material. PCBs, PBDEs, PCDD/Fs, PCNs and PFAS showed the highest potential to transfer, with laying chickens showing the most pronounced effects. PBDD/Fs showed low concentrations in the recycled materials, making it difficult to evaluate potential transfer. Higher resulting occurrence levels in laying chickens relative to broilers suggests that period of contact with the materials may influence the extent of uptake in chickens. Bio-transfer factors (BTFs) estimated for PCDD/F and PCBs showed a greater magnitude for chicken muscle tissue relative to pigs with the highest values observed for PCBs in laying chickens. There were no significant differences between BTFs for the different chicken tissues which contrasted with the high BTF values for pigs liver relative to muscle. The study raises further questions which require investigation such as the effects of repeated or yearly application of recycled materials as fertilizers, and the batch homogeneity/consistency of available recycled materials.

HLA-Dr Expression by Tumor Cells Compared with Survival in High Grade Astrocytomas

Frozen samples from 78 high grade astrocytomas were reacted with a monoclonal antibody directed against HLA-Dr invariant chain. Survival data was obtained for all 78 cases. HLA-Dr was expressed by a proportion of tumor cells in 65/78 (83 %). Comparison of the survival of positive and negative cases showed that the difference was not statistically significant (p = 0.4). The relevance of the finding is discussed in the context of the immunoreaction to brain tumors.

Mononuclear Cell Infiltrate and Hla-Dr Expression in 28 Pituitary Adenomas

Frozen sections from 28 pituitary adenomas were reacted with a panel of monoclonal antibodies to macrophages, lymphocytes and HLA-Dr invariant chain. A low number of macrophages were demonstrated in all tumors, mainly perivascular. CD8 and CD4 lymphocytes were detected in even smaller numbers in 80% and 14% of tumors respectively. B lymphocytes were present in only 1 case. An occasional NK cell was present in 1/13 cases studied. HLA-Dr antigen was expressed by macrophages in all cases and by tumor cells in 2 growth hormone-producing adenomas/19 adenomas. These findings may represent evidence for a low degree of cellular immune response to pituitary adenomas.

Abstract P2-11-15: Development of a web-based survey tool to assess change in breast cancer (BrCa) survivor knowledge after receipt of cancer treatment summary and survivorship care plan (SCP)

Intro: The Institute of Medicine advocates survivorship care plans (SCPs) as tools to improve coordination of care by improving survivor knowledge of follow-up recommendations and future risks. No evidence exists to demonstrate that SCPs impact survivor knowledge of diagnosis, treatment, or future/chronic side effects. Furthermore, there is a lack of information on existing surveys and their ability to assess survivor knowledge regarding these issues, without change over time. The purpose of this research is to report on the development of a survey assessing knowledge of diagnosis, treatment, and side effects in BrCa survivors.

Methods: Using existing literature, two oncologists created 24 questions addressing knowledge of diagnosis, treatment, and side effects. Content experts including breast oncology providers (representing multiple subspecialties), Survey Research Shared Service (SRSS) and patient advocates reviewed and revised the questions. Next, potential questions were administered in a group setting to BrCa survivors to evaluate clarity of instructions and survey wording. The Breast Cancer Knowledge (BreaCK) survey was further revised based on survivor feedback.

For pilot testing, BrCa survivors were recruited from clinic to test BreaCK survey content and clarity. Survey 1 was administered in clinic online. SRSS conducted verbal assessments regarding content after Survey 1. Four weeks later, survivors received Survey 2 via email and answered online. Correct answers were abstracted from the medical record.

Results: Nine subjects completed both surveys. Qualitatively, little intra-subject variation was seen between surveys. Subjects did not feel that the survey was burdensome or intrusive. No subject was able to correctly answer all questions. Final survey adjustments were made based on subject feedback and common incorrect answers encountered when grading the surveys. Specifically, subjects had difficulty understanding “endocrine or hormone therapy.” Furthermore, subjects reported guessing in response to some questions – additional answer categories were added, including “I don't know.”

Conclusion: Survivor knowledge did not change significantly between surveys. This suggests survivor knowledge was not impacted by the survey over the four-week interval. The revised BreaCK survey may be a useful tool for assessing survivor knowledge of diagnosis, treatment and side effects. A larger cohort of BrCa survivors is being recruited, starting Summer 2012, and will be evaluated using the survey.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-11-15.

Towards a differentiated understanding of active travel behaviour: using social theory to explore everyday commuting

Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work (‘active commuting’) as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions.

Changes in tobacco use among 13-15-year-olds between 1999 and 2007: findings from the Eastern Mediterranean Region

This report focuses on change over time in tobacco use among adolescents in countries included in the Eastern Mediterranean Region (EMR) of the World Health Organization. The Global Youth Tobacco Survey (GYTS) was conducted in each site at least twice between 1999 and 2007. Results indicate that for students aged 13-15 years tobacco use is a major public health problem. Increase in the use of water pipe, the likely initiation of smoking by never smokers, and a potential increase in tobacco use among young girls was found in most of the EMR sites. The results from the GYTS can be used by all of the EMR countries involved to set their tobacco control programme and policy agenda

Patterns of tobacco use: results from the 2005 Global Youth Tobacco Survey in Lebanon

We report the results of the 2005 Global Youth Tobacco Survey in Lebanon which investigated the self-reported attitudes and behaviours related to tobacco among 3314 Lebanese schoolchildren aged 13-15 years. Current use of any tobacco product was 60.1%; the use of cigarettes was 10% and other tobacco products 59% with male predominance in all areas. About 80% of students lived in homes where others smoked. About 60% of current smokers wanted to quit smoking and 51% of all students had learned about the effects of tobacco in class. Over a quarter (27%) thought that boys who smoke have more friends and 17% believed that smoking makes boys more attractive. The majority of students had been exposed to both anti-smoking media messages and pro-smoking advertisements.

Linking data to tobacco control program action among students aged 13-15 in Association of Southeast Asian Nations (ASEAN) member states, 2000-2006

BACKGROUND

The Association of Southeast Asian Nations (ASEAN) has made tobacco use prevention a primary health issue. All ASEAN countries except Indonesia have ratified the World Health Organization Framework Convention on Tobacco Control (WHO FCTC), the world's first public health treaty on tobacco control.

METHODS

Global Youth Tobacco Survey (GYTS) data were collected from representative samples of students in school grades associated with ages 13-15 in Cambodia, Indonesia, Laos (Vientiane), Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam (Hanoi).

RESULTS

Current cigarette smoking ranged from less than 5% (Vietnam and Cambodia) to 20.2% in Malaysia. Current use of tobacco products other than cigarettes was less than 10% in all countries. Boys were significantly more likely than girls to smoke cigarettes or use other tobacco products. Exposure to second-hand smoke in public places was greater than 50%, direct pro-tobacco advertising exposure was greater than 75% and over 10% of students were exposed to indirect advertising. Over 60% of students who currently smoked cigarettes wanted to stop, but 80% who tried to quit in the year prior to the survey failed.

CONCLUSIONS

Efforts to reduce the current and projected harm caused by tobacco use in the ASEAN countries are urgently needed. ASEAN countries need to expand their national comprehensive tobacco prevention and control programs and enforce those laws already passed. Without this effort little reduction can be expected in the burden of chronic diseases and tobacco-related mortality.

Method for cotemporal and coplanar comparison of magnetic resonance imaging and neuropathology of formalin-fixed human brains

We describe the design and production of a mitre box that allows magnetic resonance imaging and pathological sectioning of a formalin-fixed brain so that the pathological and radiological slices are coplanar and therefore readily comparable.

Tobacco use and cessation counselling: cross-country. Data from the Global Health Professions Student Survey (GHPSS), 2005-7

BACKGROUND

Brief intervention by a health professional can substantially increase smoking cessation rates among patients. However, few studies have collected information on tobacco use and training to provide cessation counselling among health professional students.

OBJECTIVE

To examine tobacco use prevalence and tobacco cessation training among students pursuing advanced degrees in health professions.

METHODS

The Global Health Professions Student Survey (GHPSS) has been conducted among third-year students attending dental, medical, nursing and pharmacy schools. The GHPSS was conducted in schools during regular lectures and class sessions. GHPSS follows an anonymous, self-administered format for data collection.

RESULTS

The GHPSS was completed by at least one of the four target disciplines in 31 countries between 2005 and 2007 for a total of 80 survey sites. In 47 of the 80 sites, over 20% of the students currently smoked cigarettes; and in 29 of 77 sites, over 10% of the students currently used other tobacco products. GHPSS data showed that the majority of health professional students recognised that they are role models in society, believed that they should receive training on counselling patients to quit using tobacco, but in 73 of 80 sites less than 40% of the students reported they received such training.

CONCLUSIONS

Health professional schools, public health organisations and education officials should discourage tobacco use among health professionals and work together to design and implement programmes that train all health professionals in effective cessation counselling techniques. If the goal of the tobacco control community is to reduce substantially the use of tobacco products, then resources should be invested in improving the quality of education of health professionals with respect to tobacco control.

Patterns of global tobacco use in young people and implications for future chronic disease burden in adults

BACKGROUND

Tobacco use is a leading preventable risk factor for many chronic disorders, which are expected to account for an increasing share of the global disease burden. As part of the Global Youth Tobacco Survey (GYTS), we aimed to assess the effect of tobacco use by young people on global mortality.

METHODS

GYTS is a school-based survey of students aged 13-15 years. The survey was undertaken at 395 sites in 131 countries and the Gaza Strip and West Bank. We questioned students about current tobacco use, susceptibility to smoking among non-smokers, and exposure to secondhand smoke at home and in public places.

FINDINGS

The difference in current cigarette smoking between boys and girls is narrower than expected in many regions of the world. Use of tobacco products other than cigarettes by students is as high as cigarette smoking in many regions. Almost one in five never-smokers reported they were susceptible to smoking in the next year. Student exposure to secondhand smoke was high both at home (more than four in ten) and in public places (more than five in ten). Never-smokers were significantly less likely than current smokers to be exposed to secondhand smoke at home (prevalence 39.1% [95% CI 36.6-41.6] vs 72.8% [64.0-81.6]) and in public places (49.5% [46.7-52.3] vs 81.2% [74.2-88.2]).

INTERPRETATION

Our findings are troubling for the future of chronic disease and tobacco-related mortality. Reduction of tobacco consumption will require a redoubling of efforts to prevent initiation and promote cessation among the large proportion of young people who currently use tobacco. High exposure to secondhand smoke suggests a need for countries to pass strong and effective smoke-free policies.

Neuropsychological and Information Processing Performance and Its Relationship to White Matter Changes Following Moderate and Severe Traumatic Brain Injury: A Preliminary Study

Reductions in information processing speed have frequently been reported following moderate and severe traumatic brain injuries (TBIs), consistent with the effects of diffuse white matter damage. Although the corpus callosum (CC) is a common site for diffuse damage following TBI, the effects of this damage on information processing speed have not been adequately examined. This study assessed a TBI group and a matched control group on tests of attention, memory, fluency, and set shifting ability, together with reaction time (RT) tasks requiring the inter- and intrahemispheric processing of visual and tactile information. The RT tasks were designed to target the cognitive functions that are likely to be affected by diffuse white matter damage, including damage to the CC. The TBI group demonstrated deficits in verbal and visual fluency and verbal memory. They were also slower on the visual and tactile RT tasks, were more affected by task complexity, and slower on RT tasks requiring the interhemispheric transfer of information. In fact, one of the interhemispheric tactile RT tasks proved to be the most discriminating of all the cognitive and RT measures. MRIs completed on a subset of TBI participants indicated that the mean CC measurements were 5% to 19% smaller than a normative control group, with the most atrophied areas being the isthmus and anterior midbody. Although white matter atrophy was moderately related to visual and tactile RT performance, and total hippocampal volume related to memory performance, CC area was not related to many of the tasks that were designed to tap interhemispheric processing. None of the standard cognitive tests correlated with outcome in the TBI group, but 1 of the tactile RT measures was significantly related to 2 measures of outcome.

Excitotoxic model of post-traumatic syringomyelia in the rat

STUDY DESIGN

A rat model was developed to elucidate the role of excitatory amino acids and spinal subarachnoid block in the genesis of post-traumatic syringomyelia. This excitotoxic model produces intramedullary cavities rather than the dilation of the central canal (canalicular syringomyelia) created by previous animal models.

OBJECTIVES

To produce extracanalicular cysts in the rat spinal cord with quisqualic acid, a potent agonist of multiple excitatory amino acid receptors, and to compare the effects of excitotoxic injury only with that of excitotoxic injury and subarachnoid block with kaolin.

SUMMARY OF BACKGROUND DATA

In post-traumatic syringomyelia, primary injury and excitotoxic cell death secondary to elevated levels of excitatory amino acids may initiate a pathologic process leading to the formation of spinal cavities. Subarachnoid block by arachnoiditis may promote enlargement of the cavities.

METHODS

Three control rats received a unilateral injection of normal saline into the spinal cord, and another five rats received an injection of kaolin into the spinal subarachnoid space. Quisqualic acid was injected unilaterally into the spinal cord of 20 rats, and 13 additional rats received a unilateral injection of quisqualic acid into the spinal cord after injection of kaolin into the subarachnoid space. Histologic and immunocytochemical assessments were undertaken.

RESULTS

In the control groups, no parenchymal cyst developed in any of the animals. Spinal cord cyst formation was observed in 16 of 19 animals in the quisqualic acid groups, but no cysts exceeding two segments in the length of the spinal cord developed in any of the rats. Much larger cavities were seen in 9 of 11 animals in the group with quisqualic acid and kaolin, and cysts exceeding two segments developed in all 9 of these (9/11; 82%).

CONCLUSIONS

In post-traumatic syringomyelia, excitotoxic cell death occurring secondarily to elevated levels of excitatory amino acids may contribute to the pathologic process leading to the formation of spinal cord cysts. Subarachnoid block by arachnoiditis is likely to cause enlargement of the cavity.

Upregulation of neuronal amyloid precursor protein (APP) and APP mRNA following magnesium sulphate (MgSO4) therapy in traumatic brain injury

The aim of this study was to assess and quantitate topographically the effects of posttraumatic intravenous magnesium sulphate (MgSO4) on neuronal perikaryal APP antigen and messenger RNA (mRNA) expression in sheep brains 2 h after a controlled focal head impact. The percentage brain area with APP immunoreactive neuronal perikarya was 71, 56, 27.5 and 5.5%, respectively, in MgSO4-treated head-injured animals, head-injured animals without any treatment, MgSO4 treated nonimpacted animals, and nontreated nonimpacted control sheep. Although there was no statistically significant difference in APP immunoreactive neuronal perikarya in the MgSO4-treated HI group (mean 71%) compared to the HI group without any treatment (mean 56%), northern analysis showed that there was a 2.3-+/-0.2-fold increase in APP mRNA in the thalamus of treated impacted animals compared to untreated impacted animals (p < 0.005). However, MgSO4 treated nonimpacted control animals also showed a 1.6-+/-0.1-fold increase in APP mRNA compared to untreated nonimpacted controls (p < 0.005). MgSO4 therapy results in upregulation of neuronal APP mRNA and APP expression that is quantitatively greater following a focal head impact.

Topography and severity of axonal injury in human spinal cord trauma using amyloid precursor protein as a marker of axonal injury

STUDY DESIGN

Axonal injury was examined in 18 human cases of acute spinal cord compression using amyloid precursor protein as a marker of AI.

OBJECTIVES

To topographically map and semiquantitate axonal injury in spinal cord compression of sufficient severity to produce para- or quadriplegia.

SUMMARY OF BACKGROUND DATA

Amyloid precursor protein is carried along the axon by fast axoplasmic transport and has been extensively used as a marker of traumatic axonal injury.

METHODS

The study group comprised 18 cases of spinal cord compression (17 due to fracture dislocation of the vertebral column and 1 iatrogenic compression from Harrington rods) and two normal control. All the cords were examined according to a standard protocol, and at least 10 segmental levels were immunostained using a monoclonal antibody to amyloid precursor protein and immunopositive AI was semiquantitated using a grading system to provide the axonal injury severity score (AISS). The focal injury at the site of cord compression (haemorrhage, haemorrhagic necrosis, ischaemic necrosis) was also semiquantitated to provide the focal injury area score (FIAS). AI occurring around the site of focal compression (focal axonal injury severity score or FAISS) was distinguished from AI distant to the focal injury (nonfocal axonal injury severity score or NFAISS).

RESULTS

All 18 cases showed widespread amyloid precursor protein immunoreactive axonal injury and the AISS ranged from 28 to 60%. In all cases, the FAISS was greater than the NFAISS and there was a statistically significant relationship between the AISS and the FIAS.

CONCLUSION

Acute spinal cord compression of sufficient severity to produce permanent paralysis causes widespread axonal damage that is maximal at the site of compression but also present throughout the length of the cord in segments far distant from the site of the focal injury.

Cervical and thoracic juxtafacet cysts causing neurologic deficits

STUDY DESIGN

Case reports and review of the literature.

OBJECTIVES

To review the clinical features, treatment, and outcome of juxtafacet cysts.

SUMMARY OF BACKGROUND DATA

There have previously been 4 reported cases of thoracic juxtafacet cysts and 19 cases of cervical juxtafacet cysts. Cervical cysts have usually originated from the cruciate ligament and caused myelopathy. Thoracic cysts are usually signaled by myelopathy.

METHODS

The records of the Neurosurgery Department of Royal Adelaide Hospital from 1980 through 1995 were reviewed for cases of intraspinal juxtafacet cysts.

RESULTS

Eight cases of intraspinal juxtafacet cysts were identified; six were in the lumbar spine. One patient had a cervical cyst related to a facet joint and had unilateral radiculopathy. A second patient with a thoracic cyst had the gradual onset of myelopathy. Both patients had surgical excision of the cyst without resection of the adherent dura. The symptoms and neurologic signs improved in each case.

CONCLUSIONS

Cervical and thoracic juxtafacet cysts are rare lesions that are usually signaled by myelopathy. Results of surgery are excellent in most cases, even if the cyst is not completely excised.

Mechanisms underlying the formation and enlargement of noncommunicating syringomyelia: experimental studies

The pathogenesis of noncommunicating syringomyelia is unknown, and none of the existing theories adequately explains the production of cysts that occur in association with conditions other than Chiari malformation. The authors' hypothesis is that an arterial pulsation–driven perivascular flow of cerebrospinal fluid (CSF) is responsible for syrinx formation and enlargement. They investigated normal CSF flow patterns in 20 rats and five sheep by using the tracer horseradish peroxidase; the effect of reducing arterial pulse pressure was examined in four sheep by partially ligating the brachiocephalic trunk; CSF flow was examined in 78 rats with the intraparenchymal kaolin model of noncommunicating syringomyelia; and extracanalicular cysts were examined using the excitotoxic model in 38 rats.

In the normal animals there was a rapid flow of CSF from the spinal subarachnoid space into the spinal cord perivascular spaces and then into the central canal. This flow ceased when arterial pulsations were diminished. In animals with noncommunicating syringomyelia, there was rapid CSF flow into isolated and enlarged segments of central canal, even when these cysts were causing pressure damage to the surrounding spinal cord. Exitotoxic injury of the spinal cord caused the formation of extracanalicular cysts, and larger cysts were produced when this injury was combined with arachnoiditis, which impaired subarachnoid CSF flow. The results of these experiments support the hypothesis that arterial pulsation–driven perivascular fluid flow is responsible for syrinx formation and enlargement.

Upregulation of amyloid precursor protein messenger RNA in response to traumatic brain injury: an ovine head impact model

There is evidence that the amyloid precursor protein (APP) plays an important role in neuronal growth and synaptic plasticity and that its increased expression following traumatic brain injury represents an acute phase response to trauma. We hypothesized that the previously described increased APP expression in response to injury (Van den Heuvel et al., Acta Neurochir. Suppl. 71, 209-211) is due to increased mRNA expression and addressed this by examining the expression of APP mRNA and APP within neuronal cell bodies over time in an ovine head impact model. Twenty-five anesthetized and ventilated 2-year-old Merino ewes sustained a left temporal head impact using a humane stunner and 9 normal sheep were used as nonimpact controls. Following postimpact survival periods of 15, 30, 45, 60, and 120 min, brains were perfusion fixed in 4% paraformaldehyde and examined according to standard neuropathological protocol. APP mRNA and antigen expression were examined in 5-microm sections by nonisotopic in situ hybridization and APP immunocytochemistry. The percentage of brain area with APP immunoreactivity within neuronal cell bodies in the impacted animals increased with time from a mean of 7.5% at 15 min to 54.5% at 2 h. Control brains showed only very small numbers of weakly APP-positive neuronal cell bodies ranging from 2 to 14% (mean 7%). Increased expression of APP mRNA was first evident in impacted hemispheres at 30 min after impact and progressively increased over time to involve neurons in all sampled regions of the brain, suggesting increased transcription of APP. In contrast, APP mRNA was undetectable in tissue from nonimpacted sheep. These data show that APP mRNA and antigen expression are sensitive early indicators of neuronal injury with widespread upregulation occurring as early as 30 min after head impact.

Cerebrospinal fluid flow in an animal model of noncommunicating syringomyelia

OBJECTIVE

The source of fluid and the mechanism of cyst enlargement in syringomyelia are unknown. It has been demonstrated that cerebrospinal fluid (CSF) normally flows from the subarachnoid space through perivascular spaces and into the spinal cord central canal. The aim of this study was to investigate whether this flow continues during cyst formation in an animal model of syringomyelia and to determine the role of subarachnoid CSF flow in this model.

METHODS

The intraparenchymal kaolin model of noncommunicating syringomyelia was established in 78 Sprague-Dawley rats. Horseradish peroxidase was used as a tracer to study CSF flow at 1 day, 3 days, 1 week, and 6 weeks after kaolin injection. CSF flow was studied at 0, 10, and 30 minutes after horseradish peroxidase injection into the cisterna magna or thoracic subarachnoid space.

RESULTS

The central canal became occluded at the level of the kaolin injection and at one or more rostral levels. Segments of the central canal isolated between occlusions gradually dilated, and axonal retraction balls were detected in the surrounding white matter. There was a partial blockage of subarachnoid CSF flow at the site of the kaolin injection, both in a rostral-caudal direction and in a caudal-rostral direction. Horseradish peroxidase was detected at all time points, in a distinctive pattern, in perivascular spaces and the central canal. This pattern was seen even where segments of the central canal were isolated and dilated.

CONCLUSION

In this animal model, noncommunicating syringes continue to enlarge even when there is evidence that they are under high pressure. There may be an increase in pulse pressure rostral to the block of subarachnoid CSF flow, causing an increase in perivascular flow and contributing to syrinx formation. The source of fluid in noncommunicating syringomyelia may be arterial pulsation-dependent CSF flow from perivascular spaces into the central canal.

A technique for in vivo vascular perfusion fixation of the sheep central nervous system

A method for perfusion fixation of the sheep central nervous system is described. The technique utilises the vascular anatomy of the spinal cord and brain to provide fixation that is comparable to transcardiac perfusion of the small animal. It can be applied with relative ease, cost effectiveness and without risking premature death of the animal due to complications of a major procedure such as thoracotomy.

Selective sensitization of adriamycin-resistant P388 murine leukemia cells to antineoplastic agents following transfection with human DNA topoisomerase II alpha

Previous studies have demonstrated decreased levels of DNA topoisomerase II alpha protein and messenger RNA in the Adriamycin-resistant P388 murine leukemia cell line P388/ADR/7 compared to the sensitive P388/4 cell line. An allelic fusion event involving the topoisomerase II alpha and the retinoic acid receptor a genes has been identified in these cells that probably contributes to the decreased topoisomerase II activity in P388/ADR/7 cells. However, this allelic mutation may be a minor contributor or even incidental to the resistance phenotype, since these cells display other candidate mechanisms of resistance, including increased P-glycoprotein, increased glutathione-S-transferase activity and an increased onset of DNA repair. To establish a role for topoisomerase II alpha in mediating the Adriamycin resistance phenotype, complementation of the mutant allele was attempted by transfecting the murine P388/ADR/7 cells with a human topoisomerase II alpha expression construct under the control of the human metallothionein IIA promoter. The majority of transfected cell lines that were obtained by selection in hygromycin B contained copies of the integrated expression construct that were rearranged. Only two of thirty-two transfected cell lines were found to contain a single, unrearranged copy of the human topoisomerase II alpha cDNA. P388/ADR/7 cell lines carrying an integrated, intact human topoisomerase II alpha expression vector were more sensitive to Adriamycin, daunorubicin, mitoxantrone, and etoposide, but not to actinomycin D and vincristine compared to control cells transfected with vector alone or cell lines with rearranged topoisomerase II alpha expression constructs. These findings suggest that topoisomerase II alpha is a selective and significant contributor to multifactorial resistance.

Arterial pulsation-dependent perivascular cerebrospinal fluid flow into the central canal in the sheep spinal cord

The impetus for the enlargement of syringes is unknown. The authors hypothesize that there is a flow of cerebrospinal fluid (CSF) from perivascular spaces into the central canal and that the flow is driven by arterial pulsations. Using horseradish peroxidase as a tracer, the CSF flow was studied in normal sheep, in sheep with damped arterial pulsations, and in sheep with lowered spinal subarachnoid pressure. The CSF flow from perivascular spaces into the central canal was demonstrated in the normal sheep, and two patterns of flow were identified: 1) from perivascular spaces in the central gray matter; and 2) from perivascular spaces in the ventral white commissure. Flow into the central canal was also observed in the sheep with lowered spinal subarachnoid pressure, but not in those with reduced arterial pulse pressure. This study provides evidence that CSF flow from perivascular spaces into the central canal is dependent on arterial pulsations. Arterial pulsation-driven CSF flow may be the impetus for the expansion of syringes.

A head impact model of early axonal injury in the sheep

Axonal injury (AI), one of the principal determinants of clinical outcome after head injury, may evolve over several hours after injury, raising the future possibility of therapeutic intervention during this period. A new head impact model of AI in sheep was developed to examine pathological and physiological changes in the brain resulting from a graded traumatic insult. In this preliminary study 10 anesthetized and ventilated Merino ewes were used. Head injury was produced by impact from a humane stunner to the temporal region of an unrestrained head. Eight sheep were studied for 1, 2, 4, or 6 h after impact. Two sham animals (no impact, 6 h survival) were also examined. Arterial blood pressure, intracranial pressure, and cerebral blood flow were monitored continuously. A physiological index of injury severity was calculated by weighting the percentage shift from preinjury values for each monitored parameter over the first hour after injury. Immunostaining with amyloid precursor protein (APP) was used as a marker of axonal damage and the distribution of APP positive axons was recorded according to a sector scoring method (APPS). Widespread AI was identified in 7 of the 8 impacted animals, around cerebral contusions and in hemispheric white matter, central gray matter, brain stem, and cerebellum, and was detected as early as 1 h after injury. The degree of axonal injury (APPS) correlated well with an index of physiological response to injury (r = 0.83, p = 0.005).

Choroid plexus arteriovenous malformations. A report of four pathologically proven cases and review of the literature

The clinical, radiological and pathological findings of four cases of primary intraventricular haemorrhage secondary to choroid plexus arteriovenous malformations (AVM) are described and the relevant literature reviewed. In three of the cases the diagnosis was confirmed or made at autopsy. The fourth case survived to undergo craniotomy followed by radiosurgery with excellent results. All AVMs originated in the choroid plexus of the lateral ventricle, and autopsy confirmation required a high degree of suspicion and the systematic microscopic examination of serial coronal sections of the ventricle with the clot in situ.

Evidence for rapid fluid flow from the subarachnoid space into the spinal cord central canal in the rat

Horseradish peroxidase (HRP) was used as a CSF tracer in Sprague-Dawley rats. One group of rats received an injection of HRP in the cisterna magna and a second group was injected in the thoracic spinal subarachnoid space. The animals were sacrificed 0, 10 or 30 min after HRP injection by rapid perfusion with paraformaldehyde and glutaraldehyde. In both groups, there was rapid HRP labeling of brain and spinal cord perivascular spaces. HRP was present in the central canal in a pattern that was not consistent with flow from the fourth ventricle: in both groups there were segments of unlabeled central canal between the fourth ventricle and central canal segments containing HRP. HRP-labeled perivascular spaces were seen in the central gray matter adjacent to the central canal. There was a distinctive pattern of interstitial HRP between perivascular spaces and the central canal. The results suggest that there is a normal flow of fluid from the subarachnoid space, into the perivascular spaces, across the interstitial space and into the central canal. The function of this flow may be to clear metabolites from the interstitial space. The existence of such a flow would add considerable support to the theory that non-communicating syringomyelia develops in segments of central canal isolated by occlusion or stenosis at each end.

Extradural haematoma: trends in outcome over 35 years

We have reviewed 35 years experience of extradural haemorrhage (EDH) in a large neurosurgical unit, based in two university hospitals, one dealing exclusively with children and the other a general hospital. A steady reduction in the mortality rate from 29 to 8.5% occurred during that period. A trend towards earlier diagnosis is noted and an increasing proportion of rural patients has been evident throughout the study period. During the time-period studied there were many significant developments: the establishment of a modern neurosurgical unit, the evolution of an intensive care unit, the availability of CT head scanning and the formal organization of rapid retrieval to service country areas. However, no single feature could be identified as the major contributor to falling mortality results. Clinical awareness and early diagnosis are the keys to successful management of EDH.

Characterization of the mononuclear cell infiltrate and HLA-Dr expression in 19 oligodendrogliomas

We have studied frozen tissue from 19 oligodendrogliomas with a panel of antibodies to lymphocytes and their subsets, macrophages, natural killer cells, and HLA-Dr antigens. Macrophages were detected in moderate numbers in 60%-100% of tumors depending on the antibody used. T lymphocytes were fewer in number than macrophages and were present in 62% of cases. Most of the T lymphocytes were of the CD8 phenotype. CD4 lymphocytes were very few in number and present in only 18%. B cells and natural killer cells were absent from all cases. HLA-Dr antigens were expressed by macrophages in all cases but never on tumor cells. The implications of these findings are that macrophages and, to a lesser extent, CD8 lymphocytes are the predominant cells infiltrating oligodendrogliomas and that they may exert cellular immune functions.

Arachnoid cyst presenting as an extradural haematoma

A case of extradural haematoma as the presenting feature of an arachnoid cyst is described. Haemorrhagic complications of arachnoid cysts are well known, but extradural haematoma is rare. A possible pathogenetic mechanism is proposed and the treatment of asymptomatic arachnoid cysts is discussed.

Mononuclear cell infiltrate and HLA-Dr expression in intra- and extradural secondary carcinomas

Frozen sections from 30 secondary carcinomas (22 intra- and 8 extradural) were reacted with a panel of monoclonal antibodies to macrophages, lymphocytes, NK cells and HLA-Dr invariant chain. A moderate number of macrophages was demonstrated in 91% of tumours. CD 8 and CD 4 lymphocytes were detected in smaller numbers in 68% and 28% of tumours respectively. B lymphocytes were present in only one tumour and NK cells were absent. There was no significant difference between the mononuclear cell infiltrate in the intra- and extradural tumours and in respect to the histological tumour type. HLA-Dr antigen was expressed by macrophages in most cases and by tumour cells in 5/22 (22%) (4 adeno and 1 anaplastic carcinoma; of which one adenocarcinoma was extradural and the remaining intradural). The results may represent evidence for a degree of cellular immune response to secondary carcinomas which is independent of the intra- or extradural location of the tumour.

Mononuclear cell infiltrate, HLA-Dr expression and proliferation in 37 acoustic schwannomas

Frozen sections from 37 schwannomas of the VIII nerve were reacted with a panel of monoclonal antibodies to macrophage, lymphocyte, HLA-Dr invariant chain and nuclear proliferation antigens. A moderate number of macrophages was demonstrated in 96% of tumours. CD8- and CD4-lymphocytes were detected in slightly smaller numbers in up to 87% and 23% of tumours respectively. B-lymphocytes were present in only 2/32 cases and NK-cells were absent from all 16 cases tested. HLA-Dr antigen was expressed by macrophages in most cases and by tumour cells in 13/24 tumours. These findings may represent evidence for a degree of cellular immune response. Occasional cells featuring nuclear proliferation were detected in 15/27 cases.

Epidermal growth factor receptor expression in 72 meningiomas

The expression of epidermal growth factor receptor (EGF-R) was studied immunohistochemically in 72 meningiomas using two monoclonal antibodies with specificities to protein and carbohydrate components, respectively, of the external domain of the EGF-R. One third of the tumors had cytoplasmic and membrane positivity with the protein-specific antibody but in none were there positive tumor cells with the carbohydrate-specific antibody which recognizes the blood group A antigen. There was no difference in EGF-R expression between typical and aggressive meningiomas. No evidence was found to support previous reports of specific EGF-R immunoreactivity in the vascular endothelial cells of meningiomas. The authors believe this discrepancy to be due to detection of normal blood group A antigen attached to endothelial cells in patients of blood group A or AB. This occurs because many monoclonal anti-EGF-R antibodies are specific for A antigen which is found on the EGF-R of A431 cells but has not been reported on EGF-R elsewhere.

Investigation of the expression of epidermal growth factor receptor and blood group A antigen in 110 human gliomas

The presence of epidermal growth factor receptor (EGF-R) and blood group A antigen was studied immunohistochemically in a series of 110 malignant gliomas using monoclonal antibodies. Fifty-seven percent of the tumours strongly expressed EGF-R on the malignant cells. Although blood group A antigen is present on EGF-R of A431 cells (a cell line derived from a human epidermoid carcinoma), in gliomas it was found only on vascular endothelial cells of tumours from blood group A patients. The results suggest that the EGF-R present in gliomas differs from that in A431 cells in the type or amount of the carbohydrate chains. This is in contrast to previous reports which have suggested that A antigen is present on EGF-R in gliomas. This has relevance in the choice of monoclonal antibodies used to study the EGF-R, as those directed against the A antigen component of the A431 cell EGF-R will not recognize EGF-R elsewhere and may cause normal blood group A antigen to be mistaken for EGF-R.

Cervical myelopathy in C.P.P.D. deposition disease

Cervical Myelopathy is a rare manifestation of calcium pyrophosphate dihydrate (C.P.P.D.) deposition disease. A case is presented where radiographically noncalcified extradural masses containing C.P.P.D. crystals were present at the C7 level, producing cord compression and neurological symptoms. These masses are thought to represent para-articular deposits related to the adjacent facet joints.

A double blind placebo controlled trial of the calcium entry blocking drug, nicardipine, in the treatment of vasospasm following severe head injury

A double blind, placebo controlled trial of nicardipine in the treatment of high Doppler Flow Velocity (DFV) following severe head injury (Glasgow Coma Score (GSC) less than or equal to 8) was performed. Thirty patients with high DFV (greater than or equal to 100 cm/s for 6 h duration) on transcranial Doppler ultrasound, were treated with nicardipine or placebo for 24 h (2.5 mg/h, increasing in steps of 2.5 mg/h at 2 h intervals (maximum rate 7.5 mg/h) depending on response of DFV). DFV was measured hourly for 24 h and then every 12 h for 2 days. Nicardipine significantly reduced DFV below the threshold of 100 cm/s (16/19 cf placebo 3/11, chi-square p less than 0.001). In the nicardipine treated group maximum DFV was significantly reduced (p less than 0.001) and time with DFV below 100 was significantly longer. Rises in DFV were significantly reduced by the drug if the DFV was normal at the time of entry. High DFV returned on cessation of the infusion. No unexpected or adverse side effects were seen. No clinical benefit was demonstrable.

Diffuse axonal injury in head trauma

Diffuse axonal injury (DAI) as defined by detailed microscopic examination was found in 34 of 80 consecutive cases of head trauma surviving for a sufficient length of time to be clinically assessed by the Royal Adelaide Hospital Neurosurgery Unit. The findings indicate that there is a spectrum of axonal injury and that one third of cases of DAI recovered sufficiently to talk between the initial head injury producing coma and subsequent death. The macroscopic "marker" lesions in the corpus callosum and dorsolateral quadrants of the brainstem were present in only 15/34 of the cases and represented the most severe end of the spectrum of DAI.

Intracranial haemorrhage from meningiomas: a report of five cases

Intracranial haemorrhage from meningiomas is rare and carries a mortality of over 40%. The authors present five cases presenting with intratumoral, intracerebral, subarachnoid or subdural haemorrhage. The relevant literature is reviewed and the pathology and possible mechanisms of haemorrhage in these tumours are discussed.

The mononuclear cell infiltrate compared with survival in high-grade astrocytomas

Frozen samples from 92 malignant astrocytomas were stained with a panel of monoclonal antibodies directed against macrophages and lymphocytes. A follow-up to death was available on 68 cases which form the basis of this study. Large numbers of macrophages were found in all cases; T lymphocytes, mostly of the CD8 phenotype were also seen in moderate numbers in 70% of cases. CD4-positive cells were present in small numbers in 32% and B cells were seen in only 8% of cases. Analysis of the survival showed no demonstrable correlation between the numbers of macrophages or CD4 lymphocytes and survival. The survival curves for parenchymal CD8 infiltration diverged after 9 months suggesting increased survival for those patients without such an infiltration but the difference failed to reach statistical significance (P = 0.37). No correlation between lymphocytic cuffing and survival was seen after studying all paraffin-embedded material. We conclude that there is no significant statistical correlation between survival and the various types of mononuclear cell infiltrating malignant astrocytomas.

A comparison of the intracellular uptake and radiosensitization efficiency in different media of uncharged 2-nitroimidazoles of varying lipophilicity

The effect of varying octanol: water partition coefficients, P, (range 0.026-260) on the uptake of uncharged 2-nitroimidazoles into Chinese hamster V79 379A cells has been studied. Average intracellular concentrations were measured by high performance liquid chromatography after centrifuging cells through oil or an aqueous medium. The ratio of intracellular concentration of radiosensitizer to extracellular concentration (Ci/Ce) for misonidazole (P = 0.43) was 0.85 for the oil method and 0.68 for the aqueous method. For values of P less than about 0.05 uptake was initially very slow and Ci was always less than Ce. When P greater than or equal to 0.1 uptake was rapid and then remained unchanged for times up to 3 h; for P greater than or equal to 10, Ci/Ce increased rapidly as P increased. Ro 31-1405 (P = 260) concentrated by a factor of 7 inside the cell. Although uptake was identical for cells suspended in full growth medium and PBS, radiosensitization was greater for cells in PBS: 1 mmol dm-3 misonidazole produced an enhancement ratio of 1.6 in full growth medium and 1.9 in PBS. This increase in radiosensitization could not be accounted for by protein binding. However, measurements on cellular non-protein sulphydryl (NPSH) demonstrated the levels to be reduced to about 60 per cent for cells in PBS. Similar reductions in NPSH levels have previously been shown not to increase the radiosensitivity of control cells but to increase greatly the effectiveness of nitroimidazole radiosensitizers.

Radiosensitization of Chinese hamster cells by oxygen and misonidazole at low X-ray doses

The radiosensitization of Chinese hamster V79 cells in vitro by air and misonidazole at low X-ray doses (0.2-6.0 Gy) had been studied. These survival data, together with high-dose data, were fitted to the linear quadratic model ln S = -(alpha D + beta D2), deriving estimates of alpha and beta by six different methods to illustrate the influence of the statistical treatment on the values so derived. This in vitro study clearly demonstrated that the survival parameters alpha and beta are dependent to some degree on the method of analysis of the raw survival data; however, their ratios, the values of oxygen enhancement ratios (OERs) and radiosensitizer enhancement ratios (SERs) derived from the different methods, are similar. All methods of analysis give reduced OERs at low radiation doses for combined low- and high-dose X-ray data. However, the OERs are still appreciably high, ranging from 2.45 to 2.50 for an oxic dose of 2 Gy. All methods of analysis gave reduced SERs at low doses for combined low and high X-ray dose data for hypoxic cells irradiated in 1 mmol dm-3 misonidazole. At survival levels corresponding to doses of 2 Gy in the presence of 1 mmol dm-3 misonidazole and SERs ranged from 1.2 to 1.5.

Acute subdural haematomas: aetiology, pathology and outcome

The aetiology, mechanisms of haemorrhage and results of treatment of a series of 63 consecutive cases of acute subdural haematoma are presented. Forty-six cases were due to trauma (46% mortality) and 17 cases were non-traumatic (41% mortality). Only 15 patients overall (24%) made a good recovery. The various mechanisms of venous and arterial bleeding leading to subdural haematoma are reviewed and the importance of brain swelling as a determinant of fatal outcome is stressed.

Human tumor cell destruction by distilled water. An in vitro evaluation

A distilled water lavage is sometimes used during tumor surgery in an effort to kill tumor cells spilled into a cavity or wound. To test the efficacy of this technique, a model study utilized nine different human tumor cell lines, subjected in vitro to hypotonic exposure for 1 to 10 minutes. Only the carcinoid, multiple myeloma, leiomyosarcoma cell lines, and normal lymphocytes were destroyed by the treatment. Although breast, ovarian, gastric, bladder, and melanoma cell lines were damaged to varying degrees, viable cells persisted in all cases. These data suggest that hypotonic shock is not an effective method to kill human tumor cells.