Immuno-metabolic impact of the multiple sclerosis patients' sera on endothelial cells of the blood-brain barrier.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease which results from the invasion of the brain by activated immune cells across the endothelial cells (ECs) of the blood-brain barrier (BBB), due to loss of immune self-tolerance. Many reports define the metabolic profile of immune cells in MS, however little is known about the metabolism of the BBB ECs during the disease. We aim to determine whether circulating factors in MS induce metabolic alterations of the BBB ECs compared to a healthy state, which can be linked with disruption of BBB integrity and subsequent immune cell extravasation. METHODS AND RESULTS: In this report, we used an in vitro model to study the effect of sera from naïve-to-treatment, relapsing-remitting MS (RRMS) patients on the human brain microvascular endothelium, comparing effects to age/sex-matched healthy donor (HD) sera. Our data show that RRMS serum components affect brain endothelial cells by impairing intercellular tightness through the down-modulation of occludin and VE-cadherin, and facilitating immune cell extravasation through upregulation of intercellular adhesion molecules (ICAM-1) and P-glycoprotein (P-gp). At a metabolic level, the treatment of the endothelial cells with RRMS sera reduced their glycolytic activity (measured through the extracellular acidification rate-ECAR) and oxygen consumption rate (oxidative phosphorylation rate-OCR). Such changes were associated with the down-modulation of endothelial glucose transporter 1 (GLUT-1) expression and by altered mitochondrial membrane potential. Higher level of reactive oxygen species released from the endothelial cells treated with RRMS sera indicate a pro-inflammatory status of the cells together with the higher expression of ICAM-1, endothelial cell cytoskeleton perturbation (stress fibres) as well as disruption of the cytoskeleton signal transduction MSK1/2 and ß-catenin phosphorylation. CONCLUSIONS: Our data suggest that circulating factors present in RRMS patient serum induce physiological and biochemical alterations to the BBB, namely reducing expression of essential tightness regulators, as well as reduced engagement of glycolysis and alteration of mitochondrial potential. As these last changes have been linked with alterations in nutrient usage and metabolic function in immune cells; we propose that the BBB endothelium of MS patients may similarly undergo metabolic dysregulation, leading to enhanced permeability and increased disease susceptibility.

Type 2 diabetes is associated with the accumulation of senescent T cells.

Type 2 diabetes is a global health priority, given that it is driven, in part, by an ageing population, the role of immune senescence has been overlooked. This is surprising, as the functional impairments of senescent T cells show strong similarities to patients with hyperglycaemia. Immune senescence is typified by alterations in T cell memory, such as the accumulation of highly differentiated end-stage memory T cells, as well as a constitutive low-grade inflammation, which drives further immune differentiation. We show here in a preliminary study that people living with type 2 diabetes have a higher circulating volume of senescent T cells accompanied with a higher level of systemic inflammation. This inflammatory environment drives the expression of a unique array of chemokine receptors on senescent T cells, most notably C-X-C motif chemokine receptor type 2. However, this increased expression of migratory markers does not translate to improved extravasation owing to a lack of glucose uptake by the T cells. Our results therefore demonstrate that the presence of senescent T cells has a detrimental impact on immune function during type 2 diabetes.

Skin resident memory CD8+ T cells are phenotypically and functionally distinct from circulating populations and lack immediate cytotoxic function.

The in-depth understanding of skin resident memory CD8+ T lymphocytes (TRM ) may help to uncover strategies for their manipulation during disease. We investigated isolated TRM from healthy human skin, which expressed the residence marker CD69, and compared them to circulating CD8+ T cell populations from the same donors. There were significantly increased proportions of CD8+ CD45RA- CD27- T cells in the skin that expressed low levels of killer cell lectin-like receptor G1 (KLRG1), CD57, perforin and granzyme B. The CD8+ TRM in skin were therefore phenotypically distinct from circulating CD8+ CD45RA- CD27- T cells that expressed high levels of all these molecules. Nevertheless, the activation of CD8+ TRM with T cell receptor (TCR)/CD28 or interleukin (IL)-2 or IL-15 in vitro induced the expression of granzyme B. Blocking signalling through the inhibitory receptor programmed cell death 1 (PD)-1 further boosted granzyme B expression. A unique feature of some CD8+ TRM cells was their ability to secrete high levels of tumour necrosis factor (TNF)-α and IL-2, a cytokine combination that was not seen frequently in circulating CD8+ T cells. The cutaneous CD8+ TRM are therefore diverse, and appear to be phenotypically and functionally distinct from circulating cells. Indeed, the surface receptors used to distinguish differentiation stages of blood T cells cannot be applied to T cells in the skin. Furthermore, the function of cutaneous TRM appears to be stringently controlled by environmental signals in situ.

Effect of Treatment With Tabalumab, a B Cell-Activating Factor Inhibitor, on Highly Sensitized Patients With End-Stage Renal Disease Awaiting Transplantation.

B cell-activation factor (BAFF) is critical for B cell maturation. Inhibition of BAFF represents an appealing target for desensitization of sensitized end-stage renal disease (ESRD) patients. We conducted a Phase 2a, single-arm, open-label exploratory study investigating the effect of tabalumab (BAFF inhibitor) in patients with ESRD and calculated panel reactive antibodies (cPRAs) >50%. The treatment period duration was 24 weeks. Eighteen patients received tabalumab, at doses of 240-mg subcutaneous (SC) at Week 0 followed by 120-mg SC monthly for 5 additional months. Patients were followed for an additional 52 weeks. Immunopharmacologic effects were characterized through analysis of blood for HLA antibodies, BAFF concentrations, immunoglobulins, T and B cell subsets, as well as pre- and posttreatment tonsil and bone marrow biopsies. Significant reductions in cPRAs were observed at Weeks 16 (p = 0.043) and 36 (p = 0.004); however, absolute reductions were small (<5%). Expected pharmacologic changes in B cell subsets and immunoglobulin reductions were observed. Two tabalumab-related serious adverse events occurred (pneumonia, worsening of peripheral neuropathy), while the most common other adverse events were injection-site pain and hypotension. Three patients received matched deceased donor transplants during follow-up. Treatment with a BAFF inhibitor resulted in statistically significant, but not clinically meaningful reduction in the cPRA from baseline (NCT01200290, Clinicaltrials.gov).

Future intensification of extreme Aleutian low events and their climate impacts.

Extreme Aleutian Low (AL) events have been associated with major ecosystem reorganisations and unusual weather patterns in the Pacific region, with serious socio-economic consequences. Yet, their future evolution and impacts on atmosphere-ocean interactions remain uncertain. Here, a large ensemble of historical and future runs from the Community Earth System Model is used to investigate the evolution of AL extremes. The frequency and persistence of AL extremes are quantified and their connection with climatic variables is examined. AL extremes become more frequent and persistent under the RCP8.5 scenario, associated with changes in precipitation and air temperature patterns over North America. Future changes in AL extremes also increase the variability of the sea surface temperature and net heat fluxes in the Kuroshio Extension, the most significant heat and energy flux region of the basin. The increased frequency and persistence of future AL extremes may potentially cause substantial changes in fisheries and ecosystems of the entire Pacific region as a knock-on effect.

Lattice effects observed in chaotic dynamics of experimental populations.

Animals and many plants are counted in discrete units. The collection of possible values (state space) of population numbers is thus a nonnegative integer lattice. Despite this fact, many mathematical population models assume a continuum of system states. The complex dynamics, such as chaos, often displayed by such continuous-state models have stimulated much ecological research; yet discrete-state models with bounded population size can display only cyclic behavior. Motivated by data from a population experiment, we compared the predictions of discrete-state and continuous-state population models. Neither the discrete- nor continuous-state models completely account for the data. Rather, the observed dynamics are explained by a stochastic blending of the chaotic dynamics predicted by the continuous-state model and the cyclic dynamics predicted by the discrete-state models. We suggest that such lattice effects could be an important component of natural population fluctuations.

Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone.

The biological carbon pump drives a flux of particulate organic carbon (POC) through the ocean and affects atmospheric levels of carbon dioxide. Short term, episodic flux events are hard to capture with current observational techniques and may thus be underrepresented in POC flux estimates. We model the potential hidden flux of POC originating from Antarctic krill, whose swarming behaviour could result in a major conduit of carbon to depth through their rapid exploitation of phytoplankton blooms and bulk egestion of rapidly sinking faecal pellets (FPs). Our model results suggest a seasonal krill FP export flux of 0.039 GT C across the Southern Ocean marginal ice zone, corresponding to 17-61% (mean 35%) of current satellite-derived export estimates for this zone. The magnitude of our conservatively estimated flux highlights the important role of large, swarming macrozooplankton in POC export and, the need to incorporate such processes more mechanistically to improve model projections.

Estimation of the costs of acute gastrointestinal illness in British Columbia, Canada.

The costs associated with gastrointestinal infection (GI) in the province of British Columbia, Canada, were estimated using data from a population-based survey in three health service delivery areas, namely Vancouver, East Kootenay and Northern Interior. The number of cases of disease, consequent expenditure of resources and associated economic costs were modeled as probability distributions in a stochastic model. Using 2004 prices, the estimated mean annual cost per capita of gastrointestinal infection was CAN$128.61 (207.96 euros), with a mean annual cost per case of CAN$1,342.57 (2,170.99 euros). The mean estimate of the overall economic burden to British Columbia was CAN$514.2 million (831.5 million euros) (95% CFI CAN$161.0 million to CAN$5.8 billion; 260.3 million euros to 9.38 billion euros). The major element of this cost was the loss of productivity associated with time away from paid employment by both the sick and their caregivers. Sensitivity analysis suggested that the uncertainty associated with the base model assumptions did not significantly affect the estimates. The results are comparable to those obtained in an earlier study using a similar analytical framework and data from the city of Hamilton, Ontario, Canada.

The potential role of Antarctic krill faecal pellets in efficient carbon export at the marginal ice zone of the South Orkney Islands in spring.

Antarctic krill (Euphausia superba) play a central role in the food web of the Southern Ocean, forming a link between primary production and large predators. Krill produce large, faecal pellets (FP) which can form a large component of mesopelagic particulate organic carbon (POC) fluxes. However, the patchy distribution of krill swarms, highly variable pellet composition, and variable sinking and attenuation rates means that these episodic, but potentially large, carbon fluxes are difficult to sample or model. We measured particle flux and type using Marine Snow Catchers (MSC) in the marginal ice zone near the South Orkneys, Antarctica. Krill FP were the dominant component of the POC flux in the upper 200 m (typically 60-85%). FP sinking velocities measured onboard were highly variable (15-507 m d-1) but overall high, with mean equivalent velocities of 172, 267, and 161 m d-1 at our three stations. The high numbers of krill FP sinking through the mesopelagic suggest that krill FP can be transferred efficiently and/or that rates of krill FP production are high. We compared our direct MSC-derived estimates of krill FP POC flux (33-154 mg C m-2 d-1) and attenuation to estimates of krill FP production based on previous measurements of krill density and literature FP egestion rates, and estimated net krill FP attenuation rates in the upper mesopelagic. Calculated attenuation rates are sensitive to krill densities in the overlying water column but suggest that krill FP could be transferred efficiently through the upper mesopelagic, and, in agreement with our MSC attenuation estimates, could make large contributions to bathypelagic POC fluxes. Our study contrasts with some others which suggest rapid FP attenuation, highlighting the need for further work to constrain attenuation rates and assess how important the contribution of Antarctic krill FP could be to the Southern Ocean biological carbon pump.

In vitro monitoring of in vivo development of human anti-thymoglobulin antibodies by ELISA.

Thymoglobulin (rATG), polyclonal immunoglobulin, is prepared from rabbits immunized with human thymocytes. It is effective in prevention and treatment of renal allograft rejection. Human antibodies against antilymphocyte preparations can reduce efficacy by accelerating drug clearance or by inducing serum sickness. We developed an enzyme-linked immunosorbent assay (ELISA) to study posttreatment development of anti-rATG. In an Institutional Review Board-approved trial, we tested 101 allograft recipients for anti-rATG antibodies. Patients received rATG intravenously at 1.25 to 2.0 mg/kg/d for 2 to 14 days. Serum samples were obtained pretreatment and at weeks 1, 2, 4, 6, and months 3 and 6 post-rATG. ELISA plates were coated with rATG (10 microg/mL). Samples were diluted 1:100 and tested in quadruplicate. Positive samples were titrated. Horseradish peroxidase-conjugated (HRPO) affinity-purified goat anti-human immunoglobulin G (H&L) antibody reacted with bound human antibody. A chromagenic substrate for HRPO was added and optical density (OD, 490 nm) was read. An OD of twice the negative control was considered positive. Mean ODs of negative and positive controls were 0.113 +/- 0.030 and 1.042 +/- 0.196, respectively. Ten patients had detectable anti-rATG before rATG administration (1:100). Thirty-five of 101 patients (35%) developed anti-rATG antibody. Patients showed an initial positive anti-rATG antibody from days 8 to 59 after infusion and titers from 1:100 to 1:4000. In spite of rATG's postulated anti-B-cell activity, this study confirms that rATG induces sensitization at a frequency and titer seen with other xenogeneic antilymphocyte antibodies. Formation of such antixenoantibodies can have a negative impact on treatment response and hence warrant monitoring.

Generation of recombinant human C3dg tetramers for the analysis of CD21 binding and function.

CD21 (complement receptor 2, CR2) binds the terminal proteolytic fragments of the third component of complement (C3) that have been covalently attached to immune complexes or other targets during the activation of complement. We used the technique of in vivo biotinylation to create a recombinant multivalent ligand for CD21. A sequence coding for a biotinylation signal peptide was added to the 3' end of the human C3dg cDNA. The modified C3dg was expressed in Escherichia coli and biotinylated intracellularly by the bacterial biotin holoenzyme synthetase (BirA) enzyme. Monomeric C3dg was unable to bind to CD21 as determined by flow cytometry, while biotinylated recombinant C3dg (rC3dg) complexed with fluorochrome-conjugated streptavidin bound tightly. Binding was observed using CD21 positive B cells but not seen on pre-B cells that do not express this complement receptor. Two assays were used to assess the functional capacity of the recombinant C3dg. First, multimeric C3dg caused the phosphorylation of the mitogen-activated kinase, p38, in mature B lymphoma cells. Second, C3dg greatly enhanced the activation of primary B cells in combination with a sub-stimulatory concentration of anti-IgM monoclonal antibody. These results illustrate the utility of the technique of in vivo biotinylation to generate ligands for cell surface receptors that require multimerization for high avidity binding and function.

Effects of (-)-RO363 at human atrial beta-adrenoceptor subtypes, the human cloned beta 3-adrenoceptor and rodent intestinal beta 3-adrenoceptors.

1. Chronic treatment of patients with beta-blockers causes atrial inotropic hyperresponsiveness through beta 2-adrenoceptors, 5-HT4 receptors and H2-receptors but apparently not through beta 1-adrenoceptors despite data claiming an increased beta 1-adrenoceptor density from homogenate binding studies. We have addressed the question of beta 1-adrenoceptor sensitivity by determining the inotropic potency and intrinsic activity of the beta 1-adrenoceptor selective partial agonist (-)-RO363 and by carrying out both homogenate binding and quantitative beta-adrenoceptor autoradiography in atria obtained from patients treated or not treated with beta-blockers. In the course of the experiments it became apparent that (-)-RO363 also may cause agonistic effects through the third atrial beta-adrenoceptor. To assess whether (-)-RO363 also caused agonistic effects through beta 3-adrenoceptors we studied its relaxant effects in rat colon and guinea-pig ileum, as well as receptor binding and adenylyl cyclase stimulation of chinese hamster ovary (CHO) cells expressing human beta 3-adrenoceptors. 2. beta-Adrenoceptors were labelled with (-)-[125I]-cyanopindolol. The density of both beta 1- and beta 2-adrenoceptors was unchanged in the 2 groups, as assessed with both quantitative receptor autoradiography and homogenate binding. The affinities of (-)-RO363 for beta 1-adrenoceptors (pKi = 8.0-7.7) and beta 2-adrenoceptors (pKi = 6.1-5.8) were not significantly different in the two groups. 3. (-)-RO363 increased atrial force with a pEC50 of 8.2 (beta-blocker treated) and 8.0 (non-beta-blocker treated) and intrinsic activity with respect to (-)-isoprenaline of 0.80 (beta-blocker treated) and 0.54 (non-beta-blocker treated) (P < 0.001) and with respect to Ca2+ (7 mM) of 0.65 (beta-blocker treated) and 0.45 (non-beta-blocker treated) (P < 0.01). The effects of (-)-RO363 were resistant to antagonism by the beta 2-adrenoceptor antagonist, ICI 118,551 (50 nM). The effects of 0.3-10 nM (-)-RO363 were antagonized by 3-10 nM of the beta 1-adrenoceptor selective antagonist CGP 20712A. The effects of 20-1000 nM (-)-RO363 were partially resistant to antagonism by 30-300 nM CGP 20712A. 4. (-)-RO363 relaxed the rat colon, partially precontracted by 30 mM KCl, with an intrinsic activity of 0.97 compared to (-)-isoprenaline. The concentration-effect curve to (-)-RO363 revealed 2 components, one antagonized by (-)-propranolol (200 nM) with pEC50 = 8.5 and fraction 0.66, the other resistant to (-)-propranolol (200 nM) with pEC50 = 5.6 and fraction 0.34 of maximal relaxation. 5. (-)-RO363 relaxed the longitudinal muscle of guinea-pig ileum, precontracted by 0.5 microM histamine, with intrinsic activity of 1.0 compared to (-)-isoprenaline and through 2 components, one antagonized by (-)-propranolol (200 nM) with pEC50 = 8.7 and fraction 0.67, the other resistant to (-)-propranolol with pEC50 = 4.9 and fraction 0.33 of maximal relaxation. 6. (-)-RO363 stimulated the adenylyl cyclase of CHO cells expressing human beta 3-adrenoceptors with pEC50 = 5.5 and intrinsic activity 0.74 with respect to (-)-isoprenaline (pEC50 = 5.9). (-)-RO363 competed for binding with [125I]-cyanopindolol at human beta 3-adrenoceptors transfected into CHO cells with pKi = 4.5. (-)-Isoprenaline (pKi = 5.2) and (-)-CGP 12177A (pKi = 6.1) also competed for binding at human beta 3-adrenoceptors. 7. We conclude that under conditions used in this study, (-)-RO363 is a potent partial agonist for human beta 1- and beta 3-adrenoceptors and appears also to activate the third human atrial beta-adrenoceptor. (-)-RO363 relaxes mammalian gut through both beta 1- and beta 3-adrenoceptors. (-)-RO363, used as a beta 1-adrenoceptor selective tool, confirms previous findings with (-)-noradrenaline that beta 1-adrenoceptor-mediated atrial effects are only slightly enhanced by chronic treatment of patients with beta-blockers. Chronic treatment with

Respiratory syncytial virus infections and intravenous gamma-globulins.

The respiratory syncytial virus (RSV) is a common cause of bronchiolitis and pneumonia in infants and young children. Throughout the world annual RSV epidemics result in numerous hospitalizations, substantial morbidity and some mortality. Until the recent introduction of ribavirin only supportive therapy has been available for treating these infections. The development of animal models of RSV infection and the observation that some lots of immunoglobulin prepared for intravenous administration contained substantial RSV-neutralization antibody titers, prompted a series of studies examining the safety and efficacy of immunoglobulin prepared for intravenous administration in the prophylaxis and treatment of RSV infections. This discussion will review our published, or soon to be published, studies on the use of Sandoglobulin for both immunoprophylaxis and immunotherapy of RSV infections in cotton rats. It will summarize studies utilizing both parenteral and topical (tracheal) Sandoglobulin therapy for RSV infections in owl monkeys. Finally the results of a small double blind trial of parenteral albumin or Sandoglobulin in the therapy of RSV bronchiolitis and/or pneumonia in hospitalized children will be reviewed. The data show that immunoprophylaxis and immunotherapy of RSV infections in laboratory animals was well-tolerated, was safe and induced highly significant reductions in RSV shedding from the lower respiratory tract. Further, immunotherapy of RSV infections in children was also well-tolerated, induced no short or long term evidence of toxicity or injury and caused significant improvements in oxygenation and reductions in RSV shed from the respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylic cranioplasty using miniplate struts.

OBJECTIVE: Cranioplasty using acrylic is a common procedure in patients with cranial defects secondary to trauma, infection, or tumor. The limitations of this technique include poor adherence of the acrylic to surrounding bone and difficulty in achieving a proper cosmetic contour in complicated cranial defects, especially those involving the orbital rim. The authors have been continually developing techniques of cranioplasty. METHODS: Ten consecutive cranioplasties were performed over the past 5 years using this new technique. TECHNIQUE: The authors describe a technique using miniplates as struts to which the acrylic is applied using a "reinforced concrete" principle. RESULTS/CONCLUSION: All patients achieved excellent cosmetic results with no complications. This technique allows contour of the repair site while the acrylic is curing and provides a more resilient resulting prosthesis.

Late surgical treatment of unilateral coronal synostosis using methyl methacrylate.

Three techniques combining the shaping of calvarial and facial bone with onlay of methyl methacrylate are presented for use in the late treatment of unilateral coronal synostosis deformities. The procedures described are suggested as possible alternatives to extensive bone repositioning procedures. They have the advantage of being quicker and are therefore potentially safer operations. Acrylic is malleable and does not resorb; thus, permanent superior esthetic results may be achieved. The two most serious risks when using this technique are infection and limitation of growth. The risk of infection may be reduced by attaching the acrylic implant securely to surrounding bone, under sterile conditions, beneath well-vascularized skin. Growth limitation may be obviated by not placing acrylic across sutures in children with enlarging skulls.

Treatment of lumbar spinal stenosis by extensive unilateral decompression and contralateral autologous bone fusion: operative technique and results.

A new surgical technique for the treatment of lumbar spinal stenosis features extensive unilateral decompression with undercutting of the spinous process and, to preserve stability, uses contralateral autologous bone fusion of the spinous processes, laminae, and facets. The operation was performed in 29 patients over a 19-month period ending in December of 1991. All individuals had been unresponsive to conservative treatment and presented with low-back pain in addition to signs and symptoms consistent with neurogenic claudication or radiculopathy. Nine had undergone previous lumbar decompressive surgery. The minimum and mean postoperative follow-up times were 2 and 2 1/2 years, respectively. The mean patient age was 64 years; only two patients were younger than 50 years of age. Of the patients with neurogenic claudication, 69% reported complete pain relief at follow-up review. Of those with radicular symptoms, 41% had complete relief and 23% had mild residual pain that was rated 3 or less on a pain-functionality scale of 0 to 10. For the entire sample, this surgery decreased pain from 9.2 to 3.3 (p < 0.0001) on the scale. Sixty-nine percent of patients were satisfied with surgery. Low-back pain was significantly relieved in 62% of all patients (p < 0.0001). Low-back pain relief correlated negatively with number of levels decompressed (p < 0.05). To assess fusion, follow-up flexion/extension radiographs were obtained, and no motion was detected at the surgically treated levels in any patient. The results suggest that this decompression procedure safely and successfully treats not only the radicular symptoms caused by lateral stenosis but also the neurogenic claudication symptoms associated with central stenosis. In addition, the procedure, by using contralateral autologous bone fusion along the laminae and spinous processes, can preserve stability without instrumentation.

Anticonvulsant effects of gamma surgery in a model of chronic spontaneous limbic epilepsy in rats.

OBJECT: The management of intractable epilepsy remains a challenge, despite advances in its surgical and nonsurgical treatment. The identification of low-risk, low-cost therapeutic strategies that lead to improved outcome is therefore an important ongoing goal of basic and clinical research. Single-dose focal ionizing beam radiation delivered at necrosis-inducing and subnecrotic levels was investigated for its effects on seizure activity by using an established model of chronic recurrent spontaneous limbic seizures in rats. METHODS: A single 90-minute period of repetitive electrical stimulation (inducing stimulus) of the hippocampus in rats elicited a single episode of status epilepticus, followed by a 2- to 4-week seizure-free period. Spontaneous recurrent seizures developed subsequently and persisted for the duration of monitoring (2-10 months). Simultaneous computerized electroencephalography and video recording were used to monitor the animals. After the establishment of spontaneous recurrent seizures, bilateral radiation centered in the ventral hippocampal formation was administered with the Leksell gamma knife, aided by a stereotactic device custom made for small animals. A center dose of 10, 20, or 40 Gy was administered using a 4-mm collimator. Control animals were subjected to the same seizure-inducing stimulus but underwent a sham treatment instead of gamma irradiation. In a second experiment, the authors examined the effects of gamma irradiation on the proclivity of hippocampal neurons to display epileptiform discharges. Naive animals were irradiated with a single 40-Gy dose, as already described. Slices of the hippocampus were prepared from animals killed between 1 and 178 days postirradiation. Sensitivity to penicillin-induced epileptiform spiking was examined in vitro in slices prepared from control and irradiated rat brains. CONCLUSIONS: In the first experiment, single doses of 20 or 40 Gy (but not 10 Gy) reduced substantially, and in some cases eliminated, behaviorally and electrographically recognized seizures. Significant reductions in both the frequency and duration of spontaneous seizures were observed during a follow-up period of up to 10 months postradiation. Histological examination of the targeted region did not reveal signs of necrosis. These findings indicate that single-dose focal ionizing beam irradiation at subnecrotic dosages reduces or eliminates repetitive spontaneous seizures in a rat model of temporal lobe epilepsy. In the second experiment, synaptically driven neuronal firing was shown to be intact in hippocampal neurons subjected to 40-Gy doses. However, the susceptibility to penicillin-induced epileptiform activity was reduced in the brain slices of animals receiving 40-Gy doses, compared with those from control rats that were not irradiated. The results provide rational support for the utility of subnecrotic gamma irradiation as a therapeutic strategy for treating epilepsy. These findings also provide evidence that a functional increase in the seizure threshold of hippocampal neurons contributes to the anticonvulsant influence of subnecrotic gamma irradiation.

Estimating the incidence of food-borne Salmonella and the effectiveness of alternative control measures using the Delphi method.

The paper describes the use of the Delphi method to estimate the incidence of food-borne Salmonella in the UK and the effectiveness of alternative control measures. A panel of experts of food-borne Salmonella participated in the Delphi survey, which involved five rounds of questioning taking place in the period July 1993 to January 1994. Participants were asked to give initial estimates for a number of parameters and invited to revise these estimates through progressive rounds of the survey at which the group responses were reported back. This process resulted in a reduction in the variation between the estimates given by individual experts. The final estimated annual incidence of food-borne Salmonella in the UK was 537,000, although significant variation remained between, individual estimates. The foods judged to be the most important modes of transmission were poultry and poultry products (50% of cases) and eggs and egg products (26% of cases). The panel was also requested to estimate the effectiveness of strategies available to reduce the incidence of food-borne Salmonella from all sources. The most effective methods were judged to be food irradiation and mandatory application of HACCP, although there were significant differences in the judged effectiveness of these technologies for individual respondents. The paper demonstrates the efficacy of the Delphi method as a mechanism for reconciling differences between expert judgements of the incidence of food-borne disease and the effectiveness of alternative control strategies.

Small cell lung carcinoma causing epidural hematoma: case report.

BACKGROUND: Epidural hematoma usually stems from trauma, yet it may occur from other etiologies, including neoplasms. We present a case of small cell lung carcinoma with focal hemorrhagic central nervous system metastasis producing an epidural hematoma, and review the associated literature. CLINICAL PRESENTATION: A 67-year-old man was undergoing chemotherapy for small cell carcinoma of the lung. Acute neurologic deterioration resulted from a large parietal epidural hematoma of non-traumatic origin. INTERVENTION: The clot was evacuated via craniotomy with marked improvement in his clinical state. Metastatic tumor was present in the scalp, muscle, bone, and dura. No gross brain invasion was apparent. CONCLUSIONS: This case illustrates the wisdom of including metastatic disease in the differential diagnosis of intracranial hemorrhage. Even epidural hematoma may result from metastatic cancer. The prevalence of lung carcinoma and the aging of the population may produce an increased appearance of this phenomenon. Appropriate evaluation and rapid intervention will aid the patient in both the acute and long-term phases, and should improve the quality of survival.

Consumer attitudes and understanding of cholesterol-lowering claims on food: randomize mock-package experiments with plant sterol and oat fibre claims.

BACKGROUND/OBJECTIVES: Few studies have examined consumer acceptability or comprehension of cholesterol-lowering claims on food labels. Our objective was to assess consumer attitudes and understanding of cholesterol-lowering claims regarding plant sterols (PS) and oat fibre (OF). SUBJECTS/METHODS: We conducted two studies on: (1) PS claims and (2) OF claims. Both studies involved a randomized mock-packaged experiment within an online survey administered to Canadian consumers. In the PS study (n=721), we tested three PS-related claims (disease risk reduction claim, function claim and nutrient content claim) and a 'tastes great' claim (control) on identical margarine containers. Similarly, in the OF study (n=710), we tested three claims related to OF and a 'taste great' claim on identical cereal boxes. In both studies, participants answered the same set of questions on attitudes and understanding of claims after seeing each mock package. RESULTS: All claims that mentioned either PS or OF resulted in more positive attitudes than the taste control claim (P<0.0001), despite all products within each study having the same nutrition profile. How consumers responded to the nutrition claims between the two studies was influenced by contextual factors such as familiarity with the functional food/component and the food product that carried the claim. CONCLUSIONS: Permitted nutrition claims are approved based on physiological evidence and are allowed on any food product as long as it meets the associated nutrient criteria. However, it is difficult to generalize attitudes and understanding of claims when they are so highly dependent on contextual factors.