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Friction modifiers (FMs) are surface-active additives added to base fluids to reduce friction between rubbing surfaces. Their effectiveness depends on their interactions with rubbing surfaces and may be mitigated by the choice of the base fluid. In this work, the performance of an imidazolium ionic liquid (ImIL) additive in polyethylene-glycol (PEG) and 1,4-butanediol for lubricating steel/steel and diamond-like-carbon/diamond-like carbon (DLC—DLC) contacts were investigated. ImIL-containing PEG reduces friction more effectively in steel—steel than DLC—DLC contacts. In contrast, adding ImIL in 1,4-butanediol results in an increase in friction in steel—steel contacts. Results from the Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and focused ion beam-transmission electron microscopy (FIB-TEM) reveal that a surface film is formed on steel during rubbing in ImIL-containing PEG. This film consists of two layers. The top layer is composed of amorphous carbon and are easily removed during rubbing. The bottom layer, which contains iron oxide and nitride compound, adheres strongly on the steel surface. This film maintains its effectiveness in a steel—steel contact even after ImIL additives are depleted. Such film is not observed in 1,4-butanediol where the adsorption of ImIL is hindered, as suggested by the quartz crystal microbalance (QCM) measurements. No benefit is observed when the base fluid on its own is sufficiently lubricious, as in the case of DLC surfaces.This work provides fundamental insights on how compatibilities among base fluid, FM, and rubbing surface affect the performance of IL as surface active additives. It reveals the structure of an ionic liquid (IL) surface film, which is effective and durable. The knowledge is useful for guiding future IL additive development.

We report a survey of neurology residency program directors (PDs) and recent neurology residency graduates about the education provided during residency on functional seizures (FS), a subtype of functional neurological disorder (FND). The purpose of our study was to assess the education gap for neurology residents about FS since patients with FS are frequently seen by neurologists, who typically conduct the evaluation and share the findings with the patient. A survey was sent to 93 Neurology residency program directors and 71 recent graduates. We obtained a low response rate of 17%. Results of the survey revealed that the most frequent settings for education on FS were within a clinical rotation in the Epilepsy Monitoring Unit (68.8% of PDs and 88.7% of recent graduate respondents) and via a single didactic lecture (81.3% of PDs and 80.3% of recent graduate respondents). The majority of programs did not provide a curriculum for training and feedback on best practices in communicating the diagnosis or on evidence-based treatments. Eighteen percent of neurology residents reported not learning how to communicate the diagnosis of FS to patients, while 77% responded that they were not taught about treatment. These results illustrate a curriculum gap in what neurology residents are taught about diagnosis and management of FS (and FND). We propose a standardized model that can be adapted in residencies.

An HPLC method for simultaneous determination of insecticide clothianidin and its metabolites (TZNG, TMG, TZMU, and MNG) in rice was developed and is described in this paper. We extracted the parent clothianidin compound and its metabolites from samples with methanol and an aliquot of the extract was evaporated in a rotary evaporator to remove methanol. The residue was dissolved in 1 mL of 0.005 M 1-sodium octansulfonate (pH 8.3) and transferred to the ENVI-CARB cartridge coupled with an HLB cartridge for solid phase extraction (SPE). Clothianidin and its 4 metabolites were eluted from the cartridges with 3.5 mL of 70% acetonitrile in 0.005 M 1-sodium octansulfonate (pH 7). Determination and separation of clothianidin and its four metabolites were performed in an Agilent Aq column using gradient mobile phase and different UV wavelengths. The average recoveries of clothianidin, TZNG, TMG, TZMU, and MNG were 110%, 87%, 113%, 108%, and 61%, respectively, spiked at 2 ppm into rice. The relative standard deviation (RSD) was determined to be less than 10% in a triple-repeated confirmation test. The limits of quantification (LOQ) were 0.05 ppm for clothianidin, TZNG, TZMU and MNG, and 0.1 ppm for TMG in rice. The method was applied for the determination of clothianidin and its metabolites in 8 polished and 4 unpolished rice grain samples, each of which was collected from a different market in Taiwan. No residue of clothianidin or any of its metabolites was found at levels or at greater than the LOQ in these rice samples.

Objective To determine the frequency and yield of neuroimaging in patients with known seizure disorders presenting to the emergency department (ED) with recurrent (nonindex) seizures. Methods We reviewed 822 consecutive ED visits for nonindex seizures at the Oregon Health & Science University and the VA Portland Health Care System. For each visit, we abstracted details of the clinical presentation, whether neuroimaging was obtained, the results of neuroimaging, and the results of previous neuroimaging studies, when available. We determined whether ED neuroimaging led to an acute change in patient management (yield). Clinical factors associated with obtaining ED neuroimaging, and with the yield of neuroimaging, were evaluated by multivariate logistic regression. Results A majority (78%) of ED seizure visits were for nonindex seizures. Neuroimaging was obtained in 381 of 822 nonindex seizure visits (46%). Of these, 11 imaging studies (3%) led to an acute change in patient management, 8 (2%) after excluding false-positive scans. Acute head trauma, prolonged alteration of consciousness, and a focal neurologic examination at presentation were associated with an increased yield of ED neuroimaging. Absent any of these 3 clinical factors the true positive yield of neuroimaging was zero. Significance ED neuroimaging was performed in nearly half of all patients presenting with nonindex seizures. A more conservative use of ED neuroimaging for nonindex seizures, based on clinical factors at presentation, could decrease imaging frequency with minimal loss of yield.

Background Open Payments is a United States federal program mandating reporting of medical industry payments to physicians, increasing transparency of physician conflicts of interest (COI). Study objectives were to assess industry payments to physician-editors, and to compare their financial COI rate to all physicians within the specialty. Methods and findings We performed a retrospective analysis of prospectively collected data, reviewing Open Payments from August 1, 2013 to December 31, 2016. We reviewed general payments (“… not made in connection with a research agreement”) and research funding to “top tier” physician-editors of highly-cited medical journals. We compared payments to physician-editors and physicians-by-specialty. In 35 journals, 333 (74.5%) of 447 “top tier” US-based editors met inclusion criteria. Of these, 212 (63.7%) received industry-associated payments in the study period. In an average year, 141 (42.3%) of physician-editors received any direct payments to themselves including general payments and research payments, 66 (19.8%) received direct payments >$5,000 (National Institutes of Health threshold for a Significant Financial Interest) and 51 (15.3%) received >$10,000. Mean annual general payments to physician-editors was $55,157 (median 3,512, standard deviation 561,885, range 10–10,981,153). Median general payments to physician-editors were mostly higher compared to all physicians within their specialty. Mean annual direct research payment to the physician-editor was $14,558 (median 4,000, range 15–174,440). Mean annual indirect research funding to the physician-editor’s institution (highly valued by academic leaders such as departmental chairs and deans) was $175,282 (median 49,107, range 0.18–5,000,000). The main study limitation was difficulty identifying physician-editors primarily responsible for making manuscript decisions. Conclusions A substantial minority of physician-editors receive payments from industry within any given year, sometimes quite large. Most editors received payment of some kind during the four-year study period. Given the extent of editors’ influences on the medical literature, more robust and accessible editor financial COI declarations are recommended.

Lubricants operating in elastohydrodynamic (EHD) contacts exhibit local variations in rheological properties when the contact pressure rises. Direct evidence of this behaviour has only been obtained by examining through-thickness velocity profiles

Summary Objective Electrocorticographic (ECoG) recordings from patients with medically intractable partial-onset seizures treated with a responsive neurostimulator system (the RNS System) that detects and stores physician-specified ECoG events provide a new data resource. Interpretation of these recordings has not yet been validated. The purpose was to evaluate the interrater interpretation of chronic ambulatory ECoG recordings obtained by the RNS System. Methods Five pairs of five experts independently classified 7,221 ECoG recordings obtained from 128 patients with medically intractable partial seizures who participated in a randomized controlled trial of the safety and efficacy of the RNS System. ECoG detections—“long episodes” or “saturations”—were classified as “seizures” or “not seizures” based on a reference definition. Interrater agreement rates and kappa score reliabilities were calculated between rater pairs from the ECoG sample as a whole and within individual patients who had more than the median number of individual ECoG recordings. Results The overall interrater agreement was 79%, with a reliability κ = 0.57 (moderate agreement). Agreement between pairs of reviewers ranged from 0.69 to 0.85. Agreement rates were 94% or better for 50% of patients. Only 25% of patients had ECoG recordings agreement rates worse than 75%. ECoGs with mixed interpretations (one reviewer “seizure”/the other—“not seizure”) consisted of periods of low amplitude activity that evolved in amplitude or periodic discharges near 2 Hz. Significance Although reliability as a whole was moderate, for the majority of patients, detections yielded highly reliably interpreted events of either electrographic seizures or nonictal epileptiform activity.

This chapter addresses the neurological and medical factors associated with psychogenic nonepileptic seizures (PNES). PNES can occur concurrently with epilepsy in 5 to 20% of patients. Traumatic brain injury (TBI) is a major cause of epilepsy, but it is also commonly cited by patients with PNES as the primary cause of their seizures. PNES are also overrepresented in patients with intellectual and learning disabilities. Patients with PNES usually have additional subjective neurological and medical complaints. Pain complaints are overrepresented in patients with PNES and are a major contributor to health care use. Cognitive complaints are also common, with a patient’s mood playing a larger role than objective cognitive dysfunction. Medically unexplained symptoms such as fibromyalgia and chronic fatigue syndrome are overrepresented in patients with PNES. Their occurrence increases the likelihood of diagnosing PNES over epilepsy. These observations reveal a complex pattern of susceptibility to the development of PNES. PNES are thus best viewed as only one symptom of a heterogeneous disorder characterized by multiple physical symptoms used to express psychological distress.

SummaryObjective Previous studies reporting circadian patterns of epileptiform activity and seizures are limited by (1) short-term recording in an epilepsy monitoring unit (EMU) with altered antiepileptic drugs (AEDs) and sleep, or (2) subjective seizure diary reports. We studied circadian patterns using long-term ambulatory intracranial recordings captured by the NeuroPace RNS System. Methods Retrospective study of RNS System trial participants with stable detection parameters over a continuous 84-day period. We analyzed all detections and long device–detected epileptiform events (long episodes) and defined a subset of subjects in whom long episodes represented electrographic seizures (LE-SZ). Spectrum resampling determined the dominant frequency periodicity and cosinor analysis identified significant circadian peaks in detected activity. Chi-square analysis was used to compare subjects grouped by region of seizure onset. Results In the 134 subjects, detections showed a strongly circadian and uniform pattern irrespective of region of onset that peaked during normal sleep hours. In contrast, long episodes and LE-SZ patterns varied by region. Neocortical regions had a monophasic, nocturnally dominant rhythm, whereas limbic regions showed a more complex pattern and diurnal peak. Rhythms in some individual limbic subjects were best fit by a dual oscillator (circadian + ultradian) model. Significance Epileptiform activity has a strong 24 h periodicity with peak nocturnal occurrence. Limbic and neocortical epilepsy show divergent circadian influences. These findings confirm that circadian patterns of epileptiform activity vary by seizure-onset zone, with implications for treatment and safety, including SUDEP.

BACKGROUND AND PURPOSE: GM volume, WMH volume, and FA are each associated with cognition; however, few studies have detected whether these 3 different types of MR imaging measurements exert independent or additive effects on cognitive performance. To detect their extent of contribution to cognitive performance, we explored the independent and additive contributions of GM atrophy, white matter injury, and white matter integrity to cognition in elderly patients. MATERIALS AND METHODS: Two hundred and 9 elderly patients participated in the study: 97 were CN adults, 65 had MCI, and 47 had dementia. We measured GM on T1-weighted MR imaging, WMH on FLAIR, and FA on DTI, along with psychometrically matched measures of 4 domains of cognitive performance, including semantic memory, episodic memory, executive function, and spatial abilities. RESULTS: As expected, patients with dementia performed significantly more poorly in all 4 cognitive domains, whereas patients with MCI performed generally less poorly than dementia patients, though considerable overlap in performance was present across groups. GM, FA, and WMH each differed significantly between diagnostic groups and were associated with cognitive measures. In multivariate models that included all 3 MR imaging measures (GM, WMH, and FA), GM volume was the strongest determinant of cognitive performance. CONCLUSIONS: These results strongly suggest that MR imaging measures of GM are more closely associated with cognitive function than WM measures across a broad range of cognitive and functional impairment.

Venturing into foreign countries is highly risky. A study was conducted to examine the internationalisation of Malaysian contractors. Considerations that guide their decisions to enter particular foreign markets were examined. Data was collected using a postal questionnaire survey, interviews and secondary data. It was found that Malaysian contractors examine a whole range of market-entry considerations before entering a particular country. The collected data were analysed to determine the applicability of the premises embedded in certain extant models of firm internationalisation in the context of the subject. It is found that in these models more often than not, market-entry considerations can be termed as ‘locational disadvantages’ rather than locational advantages. This is because these contractors, by virtue of having to deliver their services on location, are not only market-seeking, but, in the process, also have to be resource-seeking, asset-seeking and efficiency-seeking. The study finds ...

A novel methodology, based on the use of phosphorescence imaging, is applied to determine the local through-thickness velocity profile of lubricant in an elastohydrodynamic contact. The technique has spatial and temporal resolutions of 40 μm and 340 μs respectively and thus allows lubricant rheology to be investigated at conditions close to service conditions. The capability of the newly-developed method is verified by examining the flow of 5P4E polyphenyl ether, a lubricant base fluid used in very high temperature applications and is well-known for its high viscosity-pressure coefficient. Experimental results highlight the effect of the contact pressure on the velocity profile of this fluid in lubricated contacts. At low pressures, the velocity profile of 5P4E is close to linear, characteristic of Couette flow. As the local pressure increases, its velocity profile progressively deviates from a Couette profile and shear banding is evident at high pressure.

SAXS was used to investigate the morphological responses of two commercial thermoplastic poly(ether-co-urethane) elastomers during repeated uniaxial extension and stress-relaxation at constant strain. Experimental data was analysed using a “globular” morphological model, which has previously been shown to provide a good interpretation of the SAXS from these polymers. The results indicated that microdomain rotation and fragmentation coincided with and may have contributed to the strain-softening observed during the initial deformation cycles and stress relaxation. However, these morphological changes appeared to be largely reversed, when the material was allowed to retract; consequently, they appeared insufficient to account for the dramatic changes in mechanical properties and permanent set observed between the first and second extension cycles. One possible explanation is that the mechanical properties may have been dominated by a few, larger microdomains that were too large to be observed by SAXS. Alternatively, the considerable changes in scattering intensity suggested a mechanism based on the slippage of entanglements as a result of strain-induced segmental mixing.

This work investigated the thermal behavior of a series of thermoplastic poly(ether-urethane)s containing 36–71% by weight hard segments derived from 4,4′-methylene-bisphenylisocyanate and butane-1,4-diol, with poly(tetramethylene oxide) soft segments. In all materials studied, differential scanning calorimetry revealed the presence of a T1 endotherm ∼20–30°C above the annealing temperature. Morphological changes during heating were observed using small-angle X-ray scattering; the data was analyzed using “globular” models based on a one-dimensional statistical lattice or the Percus–Yevick description of liquids, both of which appeared to provide good descriptions of these materials. The results indicated that the T1 endotherm coincided with the onset of morphological changes during heating. Possible explanations are discussed, based on the melting of small hard-segment crystals or an activation energy associated with transient segmental mixing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 779–790, 2006

Polyurethane net substrates (PNS) coupled with deferoxamine (DFO) have been studied to determine the extent of Fe2+ pick-up for use in chronic wound therapy. A m solution of ferrous sulphate (FeSO4) was used to generate ferrous ions similar to those found in chronic wounds. The concentration of Fe as a function of position through the dressings was evaluated using a variety of techniques. Atomic force microscopy (AFM) and energy-filtered transmission electron microscopy (EFTEM) revealed a rough precipitated layer at the surface of activated PNS exposed to FeSO4 solution. Optical microscopy (OM) and backscattered environmental scanning electron microscopy (ESEM) showed a clear layer of Fe3+-enriched material in the surface regions exposed to DFO. The penetration depth of DFO into activated dressings was found to be 20–30 μm. Energy-dispersive X-ray (EDX) analysis was used to approximate the distribution of bound- and unbound-Fe as a function of position within BPNS and DFO-activated dressings after immersing them in a FeSO4 solution for various times. These studies have shown the activity of iron with respect to ionic state in DFO-activated PNS for potential using as dressing for chronic wounds.

Uniaxial stress‐strain behavior of a wide range of polyurethane elastomers was compared with current models of rubber‐like elasticity. Although the data could be described well by a semi‐empirical model, a systematic discrepancy was observed with more theoretically based models. This took the form of an additional energy term during deformation, which depended on the polyurethane composition. Microdomain fragmentation may provide a possible explanation. Alternatively, it may be due to the effects of segmental interactions on the relaxation of polymer chain entanglements during deformation.

A 59-year-old woman with epilepsy reported episodes of dizziness, blurred vision, and an occasional stereotyped visual hallucination of a guardian angel. She had experienced this recurrent hallucination since childhood, and could draw it in detail (figure 1). MRI brain revealed a right parieto-occipital lesion (figure 2A). Inpatient EEG monitoring captured multiple seizures evolving over the right posterior quadrant. With one typical electrographic seizure (figure 2B), she awakened from stage II sleep, reporting seeing her guardian angel at bedside within 10 seconds of electrographic seizure offset. Among focal epilepsy patients, 0.4%–3.1% report ictal religious experiences.1

Small-angle X-ray scattering data from several experimental and commercial poly(ether urethane) formulations was used to test various scattering models based on different morphologies. The best fits were generally found with ‘globular’ scattering models based on a distorted one-dimensional lattice or the Percus–Yevick model of liquid structure. Whilst this is not conclusive proof of the morphologies exhibited by the materials studied, these scattering models are roughly consistent with many AFM and TEM studies, which indicated discrete globular or elongated cylindrical microdomains. Moreover, reasons why meandering elongated or finite lamellar microdomains may behave more like globular scattering bodies are discussed. Hence, these models are proposed as a basis for interpreting scattering data from polyurethanes. Other models were unable to fit the observed scattering data adequately. A model based on the weak segregation of copolymers was rejected on the basis of deviations from the observed scattering behaviour in the Porod region. A model based on stacks of ideal (infinite, parallel, flat) lamellae was ruled out, since it was unable to reproduce the observed peak width. The Teubner–Strey model, based on microemulsion structure, was found to be incapable of fitting the data at low q, particularly for strained samples. However, this model appeared to be more successful at reproducing the scattering observed at elevated temperatures. One possible inference is that the morphologies became more akin to microemulsions during heating.

The morphological behaviour of poly(ether-urethane)s undergoing deformation was studied using two-dimensional small-angle X-ray scattering (2D-SAXS). The data was analysed using the Zernike-Prins and Percus-Yevick models, which fitted the data well and indicated morphologies composed of discrete, elongated hard segment (HS) microdomains. Although the formulations contained relatively large HS weight fractions, relatively low volume fractions of scattering bodies were indicated, which implied limited segmental de-mixing. Possible explanations for this were discussed. Curve-fitting the 2D-SAXS data for deformation experiments using the Zernike-Prins model, indicated that HS microdomains initially became aligned with the applied strain and subsequently fragmented. This suggested a morphological basis for the observed mechanical properties of these materials, which will be explored in more detail, in subsequent publications.

The mechanical properties of thermoplastic polyurethanes (TPU) depend upon their composition and the complex two‐phase morphologies, which originate from microphase separation of chains segments. In the present work, poly(ether‐urethanes) were prepared with hard segment contents from 36% to 71% by weight, by systematically varying the length of the soft‐segment macrodiol. Samples were prepared by hot pressing or solvent casting, and the resulting hard‐ and soft‐segment morphologies were characterized by using small‐angle x‐ray scattering (SAXS) and transmission electron microscopy (TEM). Environmental scanning electron microscopy (ESEM) was used to study the fracture surfaces of TPU samples. The deformation behavior of the morphology was studied in real time, by using 2‐dimensional SAXS (2D‐SAXS) at the Daresbury synchrotron radiation source. Two distinct mechanisms were identified, with the dominant mechanism in a given material dependent on the copolymer composition and the extent of microphase...

Prosthesis is often used to restore the appearance and functional mobility to individuals following limb amputatio n. The purpose of this study is to investigate the correlation between the electromyogram (EMG) signals with the rectification of patellar tendon bearing (PTB) socket. Six PTB sockets are manufactured with different compression depths at the patellar tendon region. Experiments for the subject are carried out to obtain the EMG signals using EMG telemetry system. From this study, it is found that there exists some kinds of pattern as the depths of PTB rectification is changed. As the PTB rectification depth is increased, the EMG activity rises generally yet in an N pattern for the quadriceps group for both left and right legs of the amputee. The results of this case study will lead to an appropriate range of rectification depths for prosthetists in the manufacturing of PTB sockets, and perhaps the identification of the most suitable depth for optimum transtibial amputee ambulation.

This initial Journal Club article looks at a study from Hesdorffer and colleagues1 who have calculated the lifetime risk of developing epilepsy. The study provides an elegant example of proper epidemiologic methods and results in data that have important implications for public health. When addressing public health aspects of epilepsy, it is essential to obtain an unbiased estimate of the lifetime risk of epilepsy. With this assessment, the economic burden of epilepsy, including health care expenditures, productivity loss, intangible costs such as those associated with stigma, and additional costs from medical comorbidities of epilepsy can be extrapolated.2,3 Similarly, the patient-perceived burden of epilepsy, including associations between epilepsy and poor health, unemployment, lower annual incomes, lower health-related quality of life, smoking, and obesity, can be better evaluated.4 Given this information and the proportion of the aging population that is at risk for epilepsy, the limited number of specialists able to care for epilepsy patients is a growing concern. Nearly 35% of adults with self-reported active epilepsy reported not having seen a neurologist or epileptologist in the previous year4 and the Workforce Task Force of the American Academy of Neurology predicts a shortfall of neurologists in the years to come.5 With these broad consequences of epilepsy, the questions that Hesdorffer and colleagues pose in their study are relevant to neurologic practice. What is the risk of developing epilepsy over the course of a lifetime? How much does this risk increase with age? How does the incidence of epilepsy differ among age groups? To answer these critical epidemiologic questions, Hesdorffer and colleagues performed a population-based retrospective cohort study using medical records from Southeastern Minnesota. The study population was limited to those who developed epilepsy between January 1, 1960, and December 31, 1979, as documented through the …

Introduction Posterior reversible encephalopathy syndrome (PRES) is a brain disorder characterized by clinical symptoms of headache, visual changes, altered mentation, and seizures. On neuroimaging, focal regions of symmetrical hemispheric edema are most commonly seen in the occipital lobes. It has been suggested that associated intracranial hemorrhage is present in approximately 5% to 17% of cases. We report a case of PRES with large bilateral parieto-occipital hemorrhages in the context of phentermine use. To our knowledge, this is the first reported case of phentermine use associated with PRES. Case report A 35-year-old woman taking phentermine for weight loss presented with altered mental status and 2 witnessed generalized seizures. She was found to have large bilateral parieto-occipital hemorrhages. The radiographic imaging was consistent with PRES with hemorrhagic conversion. After treatment with anti-epileptic medication, normalization of blood pressure, and discontinuation of phentermine, the patient improved clinically. Five months after the event, the patient had a repeat brain magnetic resonance imaging that showed resolution of the diffuse edema and hemorrhage. Conclusions This case of PRES with hemorrhagic conversation is distinctive in the bilateral and extensive nature of the hemorrhage, and, to our knowledge, is the first reported case of phentermine use likely resulting in PRES. Physicians should be aware of the cerebrovascular risks associated with phentermine use.

The aim of this study was to compare the ability of artificial neural networks and the Acute Physiology and Chronic Health Evaluation II score to predict mortality in adult intensive care units. The same physiological variables were used in both predictive models to predict hospital mortality from a data set of 8796 patients collected from 26 adult intensive care units in the United Kingdom and Ireland as part of the Intensive Care Society study. The results from the two models were compared with the actual outcome. The overall prediction accuracy and the overall goodness-of-fit of all the models were assessed. Both predictive models showed similar goodness-of-fit and prediction discrimination. The overall predictive and classification performance of the artificial neural network developed matched and in some aspects was better than that of Acute Physiology and Chronic Health Evaluation II.

The military and some civilian rescue agencies have a requirement for portable ventilators in the anaesthetic, resuscitation and pre-hospital environment. This paper describes two new portable ventilators specifically designed to satisfy the military requirement for lightweight, robust and versatile equipment which can also be used in a contaminated environment.

Oral exposure of mice to vomitoxin (VT) has been previously shown to enhance gene expression of several cytokines associated with macrophage activation. Here, the effects of exposure to VT in vitro on cytokine secretion and mRNA expression were determined in the murine macrophage cell line RAW 264.7. Enzyme-linked immunosorbent assay (ELISA) of supernatants revealed that significant increases in secreted tumour necrosis factor alpha (TNF-alpha) were observed 2 days after exposure to VT at 100 ng/ml and 250 ng/ml, both with and without lipopolysaccharide (LPS) activation. While VT did not affect IL-6 secretion in the absence of LPS, significantly increased IL-6 production was observed in culture supernatants after 1, 2 and 5 days of exposure to VT at 250 ng/ml in the presence of LPS. Soluble IL-1beta was not detected in control or VT-treated cell cultures with or without LPS activation. Immunochemical staining of intracellular cytokines in conjunction with flow cytometric analysis was used to detect the effects of VT on the percentage of positive cells and output per cell. The percentage of cells that produced intracellular TNF-alpha were significantly increased at 100 and 250 ng/ml VT with and without LPS whereas increased IL-6 output per cell was observed at 100 and 250 ng/ml VT with LPS. To assess the effects of VT on cytokine mRNA expression, RAW 264.7 cells were analysed semi-quantitatively using reverse transcription-polymerase chain reaction(RT-PCR) in conjunction with Southern hybridization analysis. Elevated TNF-alpha mRNA was observed at 100 and 250 ng VT/ml at 6 and 24 hr in the absence of LPS. With the addition of LPS, superinduction of TNF-alpha was not observed in the presence of VT. Increased IL-1beta and IL-6 mRNAs were observed at 100 and 250 ng VT/ml at 24 hr in the presence of LPS. These results demonstrated that VT could superinduce both cytokine secretion and mRNA levels in macrophage cultures.