Microstructural alterations of major thalamic nuclei in the chronic pediatric spinal cord injured population

Background

The brain undergoes reorganization following spinal cord injury (SCI), but little is known about how the thalamus is affected in pediatric SCIs.

Purpose

To characterize microstructural alterations in the thalamus after SCI with diffusion tensor imaging (DTI) metrics.

Methods

18 pediatric participants with chronic SCI (8-20 years) were stratified using the American Spinal Injury Association Impairment Scale (AIS) into groups: A, B, and C/D. DTI of the brain used a 3 T Siemens Verio MRI using the parameters: 20 directions, number of averages = 3, b = 1000 s/mm2, voxel size = 1.8 mm × 1.8 mm, slice thickness = 5 mm, TE = 95 ms, TR = 4300 ms, 30 slices, FOV = 230 × 230 mm2, matrix = 128 × 128, acquisition time = 4:45 min. Diffusion data was processed to generate DTI metrics FA, MD, AD, and RD.

Data analysis

DTI metrics were acquired by superimposing the AAL3 thalamic atlas onto participant diffusion images registered to MNI152 space. We utilized a multiple Mann-Whitney U-test to compare between AIS groups, considering values of p ≤ 0.05 as significant.

Results

FA, AD, RD, and MD significantly differed in thalamic nuclei between AIS groups A vs B and B vs C/D. Significant nuclei include the right ventral anterior, left intralaminar, bilateral lateral pulvinar, and right lateral geniculate.

Conclusion

Our findings suggest the presence of microstructural alterations based on SCI severity in pediatric patients. These results are encouraging and warrant further study.

Carotid angioplasty and stenting for recurrent and radiation-induced stenosis: preliminary experience

Carotid endarterectomy for atherosclerotic occlusive disease has become the standard of care for the treatment of symptomatic and asymptomatic occlusive disease of the carotid bifurcation, based on the results of the North American Symptomatic Carotid Endarterectomy Trial, as well as the Asymptomatic Carotid Atherosclerosis Study. For surgical treatment to be of benefit, the perioperative complication rate for neurological events should be 6% or less in the symptomatic population and 3% or less in the asymptomatic group. The performance of carotid endarterectomy for recurrent stenosis and radiation-induced stenosis has reported neurological events ranging from 4 to 10%. It is in this particular population that carotid angioplasty and stent placement may play a role. The authors performed a retrospective analysis of 11 patients who underwent carotid angioplasty and stent placement for recurrent or radiation-induced stenosis. One patient in whom endarterectomy was performed by the vascular surgery service had a critical stenosis distal to the endarterectomy site and awoke with a neurological deficit. This patient underwent reexploration and placement of a stent in the artery distal to the arteriotomy site. The follow-up period ranged from 7 to 12 months. Patient age ranged from 65 to 77 years (mean 75 years). Five of eight patients underwent angioplasty and stent placement for recurrent atherosclerotic disease. Two patients had radiation-induced stenosis, and one patient had a stent placed intraoperatively. All patients, with the exception of the one who underwent intraoperative stent placement, had posttreatment stenoses of less than 15%. The surgical patient had a 30% residual stenosis distally. There were no intra- or postoperative transient ischemic attacks, major or minor strokes, or deaths. Patients who have recurrent or radiation-induced stenosis are potential candidates for angioplasty and stent placement. Before this can be recommended as an alternative to surgical correction, a longer follow-up period is required.

Current use of biologic graft extenders for spinal fusion

Use of biologic graft extenders in spinal fusions is increasing. Multiple allograft alternatives exist to the "gold-standard" autologous bone grafting. The ideal graft extender is osteoconductive, osteoinductive and has osteogenic potential. While the ideal graft extender has yet to be found, available bone graft extenders have varying degrees of predominantly osteoconductive and osteoinductive properties. This review will provide an update on available graft extenders including bone morphogenetic proteins, mesenchymal stem cells, and demineralized bone matrix. The goal is to provide a review of the current use in spinal fusions and future directions in biologics for spinal fusion.

Patient safety and quality of care continue to improve in NHS North West following early implementation of the European Working Time Directive

OBJECTIVES

NHS North West aimed to fully implement the European Working Time Directive (EWTD) 1 year ahead of the August 2009 national deadline. Significant debate has taken place concerning the implications of the EWTD for patient safety. This study aims to directly address this issue by comparing parameters of patient safety in NHS North West to those nationally prior to EWTD implementation, and during 'North West-only' EWTD implementation.

DESIGN

Hospital standardised mortality ratio (HSMR), average length of stay (ALOS) and standardised readmission rate (SRR) in acute trusts across all specialties were calculated retrospectively throughout NHS North West for the three financial years from 2006/2007 to 2008/2009. These figures were compared to national data for the same parameters.

RESULTS

The analysis of HSMR, ALOS and SRR reveal no significant difference in trend across three financial years when NHS North West is compared to England. HSMR and SRR within NHS North West continued to improve at a similar rate to the England average after August 2008. The ALOS analysis shows that NHS North West performed better than the national average for the majority of the study period, with no significant change in this pattern in the period following August 2008. When the HSMRs for NHS North West and England are compared against a fixed benchmark year (2005), the data shows a continuing decrease. The NHS North West figures follow the national trend closely at all times.

CONCLUSION

The data presented in this study quantitatively demonstrates, for the first time, that implementation of the EWTD in NHS North West in August 2008 had no obvious adverse impact on key outcomes associated with patient safety and quality of care. Continued efforts will be required to address the challenge posed nationally by the restricted working hour's schedule.

Eczema, atopy and allergen exposure in adults: a population-based study

BACKGROUND

There are few published studies on geographical variation in prevalence of eczema in adults or its association with recognised risk factors for allergic disease.

OBJECTIVE

To describe the geographical variation in prevalence of eczema in adults, assess the associations with sociodemographic risk factors, serum-specific IgE and IgG, and exposure to allergen.

METHODS

A community-based sample of 8206 adults aged 27-56 years, in 25 European centres and Portland, USA, provided questionnaire information on symptoms of eczema. Serum-specific IgE to house dust mite (HDM), cat, grass and Cladosporium, and IgG and IgG4 to HDM and cat were measured. Mattress levels of mite and cat allergen were assessed.

RESULTS

Overall prevalence of eczema was 7.1% (range between countries of 2.2-17.6%). Eczema was associated with female gender [odds ratio (OR) 1.25; 95% confidence interval (CI) (1.01-1.55)], family history of atopic disease (OR 1.43; 95% CI 1.18-1.74), IgE sensitization to at least one allergen (OR 1.50; 95% CI 1.19-1.90), particularly Cladosporium (OR 3.65; 95% CI 1.81-7.37), and total IgE. Eczema was negatively associated with age and no clear associations were observed with sibship size, mattress mite and cat allergen levels or with cat and HDM-specific IgG or IgG4.

CONCLUSIONS

There is geographical variation in the prevalence of eczema in adults both within and between countries. Although the disease is associated with IgE sensitization, in this study it was not related to mattress mite or cat allergen levels.

Improvements in total mortality and lipid levels after acute myocardial infarction in an English health district (1995-1999)

OBJECTIVES

To quantify changes in 30 day and one year mortality among patients with acute myocardial infarction in southern Derbyshire (population 560 000) in each of five consecutive years (1995-1999) before the publication of the National Service Framework for coronary heart disease, and to assess the proportion of one year survivors in whom serum lipids were measured and were below target values.

DESIGN

All hospital admissions coded on the patient administration system (PAS) as "AMI" (ICD codes I-21, I-22, and I-23) and with a creatine kinase measurement in the pathology database were identified over a five year period (n = 4912). All deaths in the district are automatically notified to the PAS. Total mortality after acute myocardial infarction (30 days and one year) and lipid levels were analysed by year of admission, age group (35-74 years v > or = 75 years), and sex using unconditional logistic regression analysis.

SETTING

An acute hospitals trust and pathology laboratory, as sole service providers for a catchment population of 560 000.

RESULTS

The number of admissions for acute myocardial infarction was similar in each of the five years (n = 4912, 62% male, 63% < 75 years old). Overall, among patients aged 35-74 years there were 396 deaths (13%) at 30 days and 585 (19%) at one year; mortality was higher in women (1.28-fold at 30 days, p = 0.02) and in subjects aged 75 years or more (3.26-fold at 30 days, p < 0.0001). There was a progressive reduction in 30 day mortality of 9%/year over the five year period (95% confidence interval, 4% to 13%, p = 0.012). The proportion of one year survivors (35-74 years) in whom serum lipids were measured at least once increased from 74% in 1995 to 88% in 1999; of these, 27% of men and 23% of women had a total serum cholesterol of < 5 mmol/l in 1995, increasing to 65% and 74%, respectively, in 1998 and 1999 (p < 0.0001).

CONCLUSIONS

In the five year period 1995-1999, there was a significant year on year decline in 30 day and one year mortality after admission for acute myocardial infarction, and progressively more patients achieved cholesterol levels below 5 mmol/l. Men were more likely than women to have their lipids measured after myocardial infarction. Mortality at one year was 1.32-fold higher among women than among men.

Complete spontaneous resolution of childhood Chiari I malformation and associated syringomyelia

The diagnosis of Chiari I malformation and associated syringomyelia is often made in childhood. Since the advent of magnetic resonance imaging, these abnormalities are increasingly detected incidentally. Despite incomplete understanding of the natural history of asymptomatic Chiari I malformations, the current recommendation is to consider prophylactic surgical intervention in those with an associated syringomyelia. This case report presents a complete spontaneous resolution of a Chiari I malformation and syringomyelia in a child. It illustrates the possibility that asymptomatic children with Chiari I malformations and syringomyelia may be followed conservatively.

Reciprocal expression of the TNF family receptor herpes virus entry mediator and its ligand LIGHT on activated T cells: LIGHT down-regulates its own receptor

The TNF receptor (TNFR) family plays a central role in the development of the immune response. Here we describe the reciprocal regulation of the recently identified TNFR superfamily member herpes virus entry mediator (HVEM) (TR2) and its ligand LIGHT (TL4) on T cells following activation and the mechanism of this process. T cell activation resulted in down-regulation of HVEM and up-regulation of LIGHT, which were both more pronounced in CD8(+) than CD4(+) T lymphocytes. The analysis of HVEM and LIGHT mRNA showed an increase in the steady state level of both mRNAs following stimulation. LIGHT, which was present in cytoplasm of resting T cells, was induced both in cytoplasm and at the cell surface. For HVEM, activation resulted in cellular redistribution, with its disappearance from cell surface. HVEM down-regulation did not rely on de novo protein synthesis, in contrast to the partial dependence of LIGHT induction. Matrix metalloproteinase inhibitors did not modify HVEM expression, but did enhance LIGHT accumulation at the cell surface. However, HVEM down-regulation was partially blocked by a neutralizing mAb to LIGHT or an HVEM-Fc fusion protein during activation. As a model, we propose that following stimulation, membrane or secreted LIGHT binds to HVEM and induces receptor down-regulation. Degradation or release of LIGHT by matrix metalloproteinases then contributes to the return to baseline levels for both LIGHT and HVEM. These results reveal a self-regulating ligand/receptor system that contributes to T cell activation through the interaction of T cells with each other and probably with other cells of the immune system.

A Homogenous 384-Well High Throughput Screen for Novel Tumor Necrosis Factor Receptor: Ligand Interactions Using Time Resolved Energy Transfer

The herpes virus entry mediator (HVEM) receptor and its ligand, HVEM-L, are involved in both herpes simplex virus type-1 (HSV-1) herpes simplex virus type-2 (HSV-2) infection, and in T-cell activation such that antagonists of this interaction are expected to have utility in viral and inflammatory diseases. In this report we describe the configuration of a homogeneous 384-well assay based on time-resolved energy transfer from a europium chelate on the HVEM receptor to an allophycocyanin (APC) acceptor on the ligand. Specific time resolved emission from the acceptor is observed on receptor:ligand complex formation. The results of various direct and indirect labeling strategies are described. Several assay optimization experiments were necessary to obtain an assay that was robust to automation and file compound interference while sensitive to the effect of potential inhibitors. The signal was stable for more than 24 h at room temperature using the Eu(3+) chelates, suggesting no dissociation of the lanthanide ion. The 384-well assay was readily automated and was able to identify more than 99.5% of known positive controls in the validation studies successfully. Screening identified both a series of known potent inhibitors and several structural classes of hits that readily deconvoluted to yield single compound inhibitors with the desired functional activity in secondary biological assays. The equivalence of the data in 384- and 1536-well formats indicates that routine implementation of 1536-well chelate-based energy transfer screening appears to be primarily limited by liquid handling rather than detection issues.

Safety of intrathecal sodium nitroprusside for the treatment and prevention of refractory cerebral vasospasm and ischemia in humans

BACKGROUND AND PURPOSE

The delayed type of cerebral vasoconstriction known as cerebral vasospasm (DCV) remains an important cause of permanent neurological injury and death following aneurysmal subarachnoid hemorrhage despite best current medical therapy. The mechanism of DCV remains unknown. A new treatment for refractory DCV using intrathecally delivered sodium nitroprusside and results in 21 patients is reported.

METHODS

Candidates for treatment were patients with secured cerebral aneurysms presenting with clinical or radiographic SAH of grade 3 or higher. Patients with and without established DCV were treated. In 57% (12/21 patients) the diagnosis of severe DCV refractory to conventional treatment (HHH therapy and nimodipine) was established before treatment. Ten patients received ITSNP prophylactically. All patients with established DCV were in grave neurological condition before treatment. Procedures for vasospasm reversal were performed under simultaneous angiographic control with extensive hemodynamic and neurophysiologic monitoring. ITSNP was delivered by intraventricular or subdural catheter or by direct intraoperative suffusion. End points of intervention for established DCV were (1) durable angiographic reversal of vasoconstriction, (2) failure to effect reversal within 30 minutes, and (3) adverse effect. End points for DCV prevention were (1) post-SAH day 10 without evidence of vasoconstriction and (2) adverse effect. Cerebral angioplasty was used concomitantly in 9 treatments. The total number of treatments recorded was 171.

RESULTS

The overall neurological outcome was good or excellent in 76% of patients (16/21) overall and in 88.9% of patients (16/18) having at least a 1-month follow-up. Of the 5 patients with less-than-good outcome, 4 had presented initially with severe neurological injury (clinical SAH grade 4). Angiography demonstrated reversal or amelioration of vasoconstriction in 83% (5/6 cases) of established DCV treated by ITSNP alone. Among patients treated prophylactically, none developed clinical DCV.

CONCLUSIONS

These results suggest that ITSNP is a safe and potentially effective treatment for established DCV and cerebral ischemia refractory to conventional treatment. The preliminary results of prophylactic treatment are also favorable with regard to safety.

Therapeutic modalities for the management of cerebral vasospasm: timing of endovascular options

OBJECTIVES

To determine if a window of time could be defined during which angioplasty would be most effective in reversing neurological decline and ultimately improving outcome.

METHODS

Of a group of 466 patients, 93 underwent endovascular management of clinical vasospasm that was medically refractory. Eighty-four of the 93 patients were available for follow-up for at least 6 months. All patients underwent mechanical angioplasty using compliant microballoon systems and, if distal spasm was present, the administration of papaverine.

RESULTS

Fifty-one patients underwent endovascular management within a 2-hour window, and 33 patients underwent treatment more than 2 hours after the development of their symptoms. Compared with the group treated more than 2 hours after neurological decline (P < 0.01; chi2 = 8.02), the group that underwent endovascular management within a 2-hour window after the development of symptoms demonstrated sustained clinical improvement.

CONCLUSION

When a patient develops symptomatic vasospasm and is unresponsive to traditional measures of critical care management, angioplasty may be effective in improving the patient's neurological status if this procedure is performed as early as possible. The results indicate that a 2-hour window may exist for restoration of blood flow to ultimately improve the patient's outcome.

Characterization of a novel TNF-like ligand and recently described TNF ligand and TNF receptor superfamily genes and their constitutive and inducible expression in hematopoietic and non-hematopoietic cells

A novel (TL1), a recently described (TL2) TNF-like, and three recently described TNF receptor-like (TR1, TR2, TR3) molecules were identified by searching a cDNA database. TL1 and TL2 are type-II membrane proteins. TR2 and TR3 are type-I membrane proteins whereas TR1 appears to be a secreted protein. TL1, TL2, TR2 and TR3 were expressed in hematopoietic cells, whereas TR1 was not. Northern blots hybridized with the cDNA probes revealed multiple forms of RNA as well as inducible expression of TL1, TL2, TR2 and TR3. TL2 and TR3, in particular, were highly induced in activated CD4+ T cells. Radiation hybrid mapping localized TR1 and TL2 to 8q24 and 3q26, respectively, which are not near any known superfamily members. TL1 was mapped to 9q32, near CD30L (9q33) and TR2 and TR3 mapped to the region of chromosome 1 that contains the TNFR-II, 4-1BB, OX40 and CD30 gene cluster at 1p36. Only TR3 in this cluster possesses a death domain. Southern blot analysis revealed the presence of TL and TR genes in different mammalian species. TL2, TR1, TR2 and TR3 were recently described by others as TRAIL/Apo-2L, OPG, HVEM and DR3/WSL-1/Apo-3/TRAMP/LARD, respectively.

A newly identified member of the tumor necrosis factor receptor superfamily with a wide tissue distribution and involvement in lymphocyte activation

The tumor necrosis factor receptor (TNFR) superfamily consists of approximately 10 characterized members of human proteins. We have identified a new member of the TNFR superfamily, TR2, from a search of an expressed sequence tag data base. cDNA cloning and Northern blot hybridization demonstrated multiple mRNA species, of which a 1.7-kilobase form was most abundant. However, TR2 is encoded by a single gene which, maps to chromosome 1p36.22-36.3, in the same region as several other members of the TNFR superfamily. The most abundant TR2 open reading frame encodes a 283-amino acid single transmembrane protein with a 36-residue signal sequence, two perfect and two imperfect TNFR-like cysteine-rich domains, and a short cytoplasmic tail with some similarity to 4-1BB and CD40. TR2 mRNA is expressed in multiple human tissues and cell lines and shows a constitutive and relatively high expression in peripheral blood T cells, B cells, and monocytes. A TR2-Fc fusion protein inhibited a mixed lymphocyte reaction-mediated proliferation suggesting that the receptor and/or its ligand play a role in T cell stimulation.