High-titer screening PCR: a successful strategy for reducing the parvovirus B19 load in plasma pools for fractionation

BACKGROUND

Human parvovirus B19 (B19) is regarded as a potential risk factor for certain patient populations receiving plasma components.

STUDY DESIGN AND METHODS

The prevalence of B19 was determined in a limited plasma donor population. Conditions for high-titer screening PCR were designed to allow the removal of plasma donations in the acute phase of infection with virus loads >or=10(7) genome equivalents per milliliter before manufacturing. Antithrombin III lots originating from screened plasma were compared to lots originating from untested plasma with respect to their B19 DNA load by a sensitive PCR assay.

RESULTS

B19 was shown to have a prevalence of about 1 per 800 plasma donations. Only a minority (1/8000) of occurrences were in the acute phase of infection. Removing plasma units with high virus load as determined by high-titer screening PCR significantly decreased peak virus loads of plasma pools for fractionation. Together with a virus-removal capacity of 10.4 log(10) of the manufacturing process, this screening resulted in a final antithrombin III product that was nonreactive for B19 on PCR.

CONCLUSION

Combining the strategy of high-titer screening PCR with the virus reduction capacity of the manufacturing process considerably increased the margin of B19 virus safety of antithrombin III. This strategy should have positive impact on other plasma components as well.

Reduction of chronic aggressive behaviour 10 years after brain injury

This study demonstrates the successful management of aggressive behaviour with a client 10 years post-injury in a small, residential neurorehabilitation unit. The case presented is unusual for two main reasons. First, it proved possible to significantly modify previously chronic challenging behaviour many years after brain injury had been sustained. Secondly, the rehabilitation environment in which treatment was conducted did not comprise a highly specialized neurobehavioural service, Instead, staff were specifically trained regarding the administration of the treatment programme, which was based on principles derived from behaviour modification and applied neuropsychology. Specific interventions used included those of differential reinforcement and graduated increase of expectations. Recordings made over the course of 85 weeks demonstrate a significant decrease in the frequency and severity of aggression. Successful inhibition of challenging behaviour attained a level which facilitated transfer of the client to a non-institutionalized community home. Reasons underlying the success of the intervention, and the limitations inherent in attempting to manage aggression within neurorehabilitation environments will be discussed.

Peripheral WBC count and serum prolactin level in various seizure types and nonepileptic events

PURPOSE

To analyze effects of different types of seizures and nonepileptic events as well as effects of seizure duration and lapse between the time of seizure and blood collection on serum prolactin level and peripheral white blood cell (WBC) count.

METHODS

We prospectively collected blood samples from all patients admitted to our Epilepsy Monitoring Unit at baseline and after an event. Blood samples were analyzed, and serum prolactin level and WBC count were determined. Statistical analyses were performed to evaluate the relation of each type of seizure, its duration, and time lapse between a seizure and collection of blood sample to the serum prolactin level and peripheral WBC count.

RESULTS

Serum prolactin level increases above twice the level at baseline after a complex partial seizure or a generalized seizure. Peripheral WBC count is elevated above the upper limit of normal in about one third of cases after a generalized seizure. In generalized seizures, the length of a seizure is positively associated, whereas the lapse time between the seizure onset and blood draw is negatively correlated with the increase in WBC count. Thus the longer the seizure and quicker the blood draw, the higher the WBC count.

CONCLUSIONS

We conclude that complex partial or generalized seizures are associated with an increase in serum prolactin level. Peripheral WBC count increases significantly after a generalized seizure and is probably transient in nature.

Volumetric MRI, pathological, and neuropsychological progression in hippocampal sclerosis

OBJECTIVE

To examine the relationships between age at onset and duration of seizure disorder with severity of hippocampal sclerosis (HS) and cognitive functioning in patients with HS and unilateral temporal lobe epilepsy.

METHODS

Twenty-six subjects had left temporal lobe seizure onset; 20 had right temporal onset. Measures were age at seizure onset, duration of seizure disorder divided by age (seizure duration), history of febrile convulsion (FC), ratio of the smaller hippocampal volume to the larger (HF) as determined by volumetric MRI, and pathologic HS grade.

RESULTS

Results showed that pathologic HS grade and HF were positively related to seizure duration, and negatively related to seizure onset. When subjects were divided into onset prior to age 10 versus later, subjects with earlier onset had higher mean pathologic HS grade and smaller (more asymmetric) mean HF. When subjects were divided into seizure duration <0.5 (i.e., less than half current lifetime) vs greater, subjects with seizure duration > or =0.5 had higher mean pathologic HS grade and lower mean HF. There was also evidence for earlier age at seizure onset and longer seizure duration being associated with worse performance on neuropsychological measures. FC was not related to either seizure duration or age at seizure onset, but patients with a history of FC showed higher pathologic HS grade and lower HF. A history of FC was not related to cognitive functioning.

CONCLUSIONS

Unilateral HS patients with earlier seizure onset and longer duration of epilepsy have more severe HS and greater hippocampal volume asymmetry. This suggests that HS may be a progressive disorder with risk for cognitive dysfunction.

Relationship of flumazenil and glucose PET abnormalities to neocortical epilepsy surgery outcome

BACKGROUND

Cortical areas showing abnormal glucose metabolism and [(11)C]flumazenil (FMZ) binding are commonly seen on PET scans of patients with intractable partial epilepsy, but it is unclear whether these must be totally resected to achieve seizure control.

OBJECTIVE

To analyze whether the extent of cortex showing 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) or FMZ PET abnormalities correlates with the outcome of resective epilepsy surgery.

METHODS

Cortical FDG and FMZ PET abnormalities in 15 young patients (mean age, 12.2 +/- 7.0 years) with intractable partial epilepsy of neocortical origin were marked as regions with abnormal asymmetry using an objective semiautomated software package. These marked regions were then projected and measured on the brain surface reconstructed from the coregistered high-resolution MRI. Following cortical resection, the size of nonresected cortex with preoperative PET abnormalities was also measured (calculated separately for marked areas in the lobe of seizure onset as defined by long-term video EEG monitoring, and in remote cortical areas). Extent of preoperative PET abnormalities and postoperative nonresected cortex abnormalities on PET were correlated with outcome scores.

RESULTS

Large preoperative FMZ PET abnormalities were associated with poor outcome (r = 0.57; p = 0.025). Larger areas of nonresected cortex with preoperative FMZ PET abnormalities in the lobe of seizure onset were also associated with worse outcome in the whole group (r = 0.66; p = 0.007) as well as in patients with extratemporal resection (r = 0.73; p = 0.007), and in those with no lesion on MRI (r = 0.60; p = 0.049). Patients with seizure-free outcome had significantly smaller nonresected cortex with preoperative FMZ PET abnormalities than those who continued to have seizures (p = 0.022). No significant correlations between nonresected FDG PET abnormalities and surgical outcome were found.

CONCLUSIONS

Extensive cortical abnormalities on FMZ PET predict poor outcome in neocortical epilepsy surgery. Resection of FMZ abnormalities in the lobe of seizure onset is associated with excellent outcome even in the absence of a structural lesion. In contrast, although FDG PET abnormalities regionalized the epileptogenic area, their size was not related to the extent of epileptogenic tissue to be removed.

Disrupting Il13 impairs production of IL-4 specified by the linked allele

Interleukin 13-deficient (IL-13-/-) mice express a defect in priming for IL-4 production that is not corrected by adding IL-13 to the priming culture. This is partly accounted for by the consumption of IL-4 without endogenous replacement during culture of IL-13-/- CD4+ T cells. We examined cells from mice in which disrupted Il13 was linked to wild-type Il4 on one chromosome and wild-type Il13 was linked to a "knocked-in" green fluorescent protein (Gfp) gene in the Il4 locus. Our results show that the deficit in IL-4 production was due, at least in part, to a cis effect, in which disrupted Il13 diminished IL-4 production from the linked Il4 gene.

Spontaneous temporal encephaloceles masked by dual pathology: report of two cases

Spontaneous temporal meningoencephaloceles are rare entities and diagnostic difficulties can occur. We present two cases whose presentation was atypical and diagnosis delayed by the presence of dual pathology.

Death from multi-resistant shigellosis in Fiji Islands

Death from Shigellosis is rare in developed countries, however it causes over a million deaths in developing countries worldwide annually. Death from shigellosis is rare in Fiji. However, the global problem of emerging multidrug resistance raises some issues about the management of Shigellosis in this country. Within Fiji, Shigella is a notifiable disease. The Fiji Ministry of Health recorded 68 cases of Shigella in 1996, 173 cases in 1997 and 334 cases in 1998 (no data available for 1999). There was only one recorded death during this time--in 1998. Resistance to chloramphenicol occurred in 82% of cases. Shigella flexneri in Fiji remains sensitive to cephalothin and cefaclor. The current antibiotic guidelines in Fiji, recommend that antibiotics be used only for cases of moderate and severe dysentery. Shigellosis was suspected soon after presentation however the patient was unable to take oral antibiotics and was treated with intravenous antibiotics (chloramphenicol and ampicillin), which were ineffective due to resistance of the organism. The current antibiotic guidelines for severe dysentery recommend chloramphenicol or nalidixic acid--the later not available in Fiji. However the only intravenous drugs that retain their sensitivity to Shigella-ceftriaxone and cephalothin, are expensive ($F 45.00 per vial of ceftriaxone) and these are only available in large regional hospitals.

Naratriptan as short-term prophylaxis of menstrually associated migraine: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To determine the efficacy of naratriptan 1-mg and 2.5-mg tablets twice daily compared with placebo as short-term prophylaxis of menstrually associated migraine.

BACKGROUND

Approximately 60% of women with migraine report headaches associated with their menstrual cycles. Results from an open-label study suggest that short-term administration of sumatriptan is useful in the prophylaxis of menstrually associated migraine.

METHODS

A randomized, double-blind, three-arm, parallel-group, placebo-controlled study was conducted in women aged 18 years or older with a history of migraine with or without aura, as defined by the International Headache Society, of at least 6 months. Two dose strengths of naratriptan (1 mg, 2.5 mg) or identical-appearing placebo tablets (1:1:1) were administered twice daily for 5 days starting 2 days prior to the expected onset of menses across four perimenstrual periods. End points included the number of menstrually associated migraines, total migraine days, peak headache severity, lost work/activity time, migraine-related quality of life, and incidence of adverse events.

RESULTS

Overall, the intent-to-treat population comprised 206 women (naratriptan 1 mg, n = 70; naratriptan 2.5 mg, n = 70, and placebo, n = 66); 171 women treated four perimenstrual periods. Significantly more perimenstrual periods per subject treated with naratriptan, 1 mg, were headache-free compared with placebo (50% versus 25%, P =.003). Naratriptan, 1 mg, significantly reduced the number of menstrually associated migraines (2.0 versus 4.0, P <.05) and menstrually associated migraine days (4.2 versus 7.0, P <.01) compared with placebo. More patients treated with naratriptan, 1 mg, were headache-free across all treated perimenstrual periods compared with placebo (23% versus 8%). No difference in headache severity was observed in breakthrough headaches. The incidence and severity of adverse events was similar across treatment groups. Naratriptan, 2.5 mg, was not statistically superior to placebo for any measure.

CONCLUSIONS

Naratriptan, 1 mg, with tolerability similar to placebo, is an effective, short-term, prophylactic treatment for menstrually associated migraine.

Structural analysis of the binding modes of minor groove ligands comprised of disubstituted benzenes

Two-dimensional homonuclear NMR was used to characterize synthetic DNA minor groove-binding ligands in complexes with oligonucleotides containing three different A-T binding sites. The three ligands studied have a C(2) axis of symmetry and have the same general structural motif of a central para-substituted benzene ring flanked by two meta-substituted rings, giving the molecules a crescent shape. As with other ligands of this shape, specificity seems to arise from a tight fit in the narrow minor groove of the preferred A-T-rich sequences. We found that these ligands slide between binding subsites, behavior attributed to the fact that all of the amide protons in the ligand backbone cannot hydrogen bond to the minor groove simultaneously.

Improved quality of life among patients with symptomatic carotid artery disease undergoing carotid endarterectomy

BACKGROUND

Few studies have examined how carotid endarterectomy affects patients' view of their quality of life.

METHODS

Patients undergoing carotid endarterectomy from January 1996 to March 1997 at the John Radcliffe Hospital completed the United Kingdom Short Form 36 (SF-36) Health Survey Questionnaire before undergoing the procedure and again at 3 months afterward. Scores were compared with population normal values.

RESULTS

In 50 patients with symptomatic carotid artery disease, there was significant improvement in the SF-36 overall "change in health" score after the procedure compared with beforehand (61.0 +/- 3.7 vs 44.5 +/- 3.4, P =.003, Wilcoxon signed rank test). There were, however, no statistically significant differences in the group's mean SF-36 subscores after operation compared with before the procedure. The physical subscores were below age-adjusted healthy population means but similar to those for chronically ill patients (physical function subscore P =.015 vs normal, P =.89 vs ill; role limitation-physical subscore P =.007 vs normal, P =.89 vs ill). Patients with postoperative complications did not have an improved change in health score (-12.5 vs 22.0, P =.03, Mann-Whitney U test). There was no effect on change in health score because of other risk factors or in patients with contralateral carotid artery occlusion or a history of preoperative stroke.

CONCLUSIONS

Patients with symptomatic carotid artery disease undergoing an uncomplicated carotid endarterectomy perceive improved quality of life and overall health. There is no perception of worsened pain, energy, or physical or mental function after the procedure. These results confirm that patients believe that performance of carotid endarterectomy improves their overall health, supporting the surgical approach to carotid artery disease.

Regulation of expression of IL-4 alleles: analysis using a chimeric GFP/IL-4 gene

CD4 cells from mice heterozygous for an IL-4 and a GFP/IL-4 gene frequently express a single allele. Analysis of IL-4 or GFP production by cells from recently primed Th2 cells indicates that essentially all are competent to transcribe either allele but have a low probability of doing so. By contrast, long-term Th2 clones show distinct and heritable ratios in the proportion of cells that express IL-4 or GFP. We conclude that in the course of Th2 priming an early efficient event renders both alleles capable of being inefficiently transcribed; a second, less frequent event occurs that renders one allele more competent, accounting for the differential expression of IL-4 and GFP in different clones.

NKT cell-mediated repression of tumor immunosurveillance by IL-13 and the IL-4R-STAT6 pathway

Using a mouse model in which tumors show a growth-regression-recurrence pattern, we investigated the mechanisms for down-regulation of cytotoxic T lymphocyte-mediated tumor immunosurveillance. We found that interleukin 4 receptor (IL-4R) knockout and downstream signal transducer and activator of transcription 6 (STAT6) knockout, but not IL-4 knockout, mice resisted tumor recurrence, which implicated IL-13, the only other cytokine that uses the IL-4R-STAT6 pathway. We confirmed this by IL-13 inhibitor (sIL-13R alpha 2-Fc) treatment. Loss of natural killer T cells (NKT cells) in CD1 knockout mice resulted in decreased IL-13 production and resistance to recurrence. Thus, NKT cells and IL-13, possibly produced by NKT cells and signaling through the IL-4R-STAT6 pathway, are necessary for down-regulation of tumor immunosurveillance. IL-13 inhibitors may prove to be a useful tool in cancer immunotherapy.

The use of stimulus-biased assay systems to detect agonist-specific receptor active states: implications for the trafficking of receptor stimulus by agonists

The quantitative comparison of the relative potency of agonists is a standard method of receptor and agonist classification. If agonist potency ratios do not correspond in two given tissues, this is used as presumptive data to conclude that the receptors in those two tissues are different. This article presents data to show that a single receptor can demonstrate varying agonist potency ratios in different host cells. These data are described in terms of the production of more than one agonist-selective receptor active state and the interaction of these different active states with multiple G proteins in the membrane to produce cellular response. Stable host human embryonic kidney 293 cells with enhanced quantities of the respective Galpha-protein were created. Wild-type and Galpha-subunit enriched cells were then transiently transfected with human calcitonin receptor type 2 (hCTR2). Binding did not detect differences in the G protein-enriched cells versus wild-type cells. In contrast, functional studies did show differences between the host cell lines and Galpha-subunit enriched cell lines. The relative potency of eight calcitonin agonists was measured in studies of calcium fluorescence in transfected cells containing human calcitonin receptor type 2 by comparing pEC(50) (-log molar concentration producing half-maximal response) values. In Galphas-enriched cells, the relative order of potency of the agonists changed. The host-cell dependent differences in potency ratios ranged from 2-fold to more than 46-fold. This finding is not consistent with the idea that all of the agonists produce response in the same manner (i.e., through a common active state of the receptor). These data are consistent with the idea that these different agonists produce arrays of active states that differentially use G proteins. This idea is discussed in terms of the design of stimulus-bias assay systems to detect agonist-selective receptor active states with resulting potential for increased selectivity of agonists.

Human serum paraoxonase (PON1) isozymes Q and R hydrolyze lactones and cyclic carbonate esters

It is well established that human serum paraoxonase (PON1) catalyzes the hydrolysis of organophosphate insecticides and nerve agents, as well as that of a number of aromatic carboxylic acid esters. Our laboratory has recently found a new class of PON1 substrates that includes at least 30 lactones and cyclic carbonate esters. The lactone substrates vary in their ring size from 4 to 7 atoms. Substituents on the ring carbons may enhance or reduce the rate of lactone hydrolysis. An appreciable degree of stereospecificity exists with some activities differing up to 9-fold between enantiomers (i.e., S-alpha-hydroxy-gamma-butyrolactone is hydrolyzed 5 to 9 times faster than the R form). Thiolactones are hydrolyzed less efficiently, and some lactams are potent inhibitors. Four lactone-containing drugs-spironolactone, mevastatin, simvastatin, and lovastatin-have been identified as substrates for PON1. All lactone substrates are hydrolyzed by both the Q and R isozymes of human serum PON1. However, some lactone substrates are hydrolyzed faster by the Q than R isozyme, whereas others show a reverse preference. Moreover, these new substrates include homogentisic acid lactone, mevalonic acid lactone, homocysteine thiolactone, and gamma-hydroxybutyric acid lactone-all lactone forms of endogenous compounds. It is reasonable to expect that further investigations may uncover PON1 lactone substrates that are, themselves, endogenous compounds. In this article we characterize the basic enzymatic properties of PON1's newly identified hydrolytic activities with lactone and cyclic carbonate ester substrates and compare these properties with those of representative arylesters and organophosphates.

Electroclinical correlates of flumazenil and fluorodeoxyglucose PET abnormalities in lesional epilepsy

OBJECTIVE

To analyze the clinical utility of [11C]flumazenil (FMZ) PET to detect perilesional and remote cortical areas of abnormal benzodiazepine receptor binding in relation to MRI, 2-deoxy-2-[18F]fluoro-d-glucose (FDG) PET, and electrocorticographic (ECoG) findings as well as clinical characteristics of the epilepsy in epileptic patients with brain lesion.

BACKGROUND

The success of resective surgery in patients with medically intractable epilepsy and brain lesion depends not only on removal of the lesion itself but also on the reliable presurgical delineation of the epileptic cortex that commonly extends beyond it. PET could provide a noninvasive identification of such epileptogenic areas.

METHODS

Seventeen patients underwent high resolution MRI, FDG and FMZ PET, and presurgical EEG evaluation, including chronic intracranial ECoG monitoring or intraoperative ECoG. Regional cortical FDG/FMZ PET abnormalities were defined on partial volume-corrected PET images using an objective method based on a semiautomated definition of areas with abnormal asymmetry. Structural lesions were defined on coregistered MRI. The marked PET abnormalities visualized on three-dimensional cortical surface were compared with each other, to the extent of MRI-defined lesion, as well as to ECoG findings.

RESULTS

The mean surface extent of FMZ PET abnormalities was significantly larger than the corresponding structural lesions, but it was significantly smaller than areas of glucose hypometabolism. The size of perilesional FDG PET abnormalities showed a correlation with the lifetime number of seizures (r = 0.93, p = 0.001). The extent of perilesional FMZ PET abnormalities was independent of the seizure number and showed an excellent correspondence with spiking cortex, the resection of which resulted in seizure-free outcome in all but one operated patient. Remote FMZ PET abnormalities (n = 6) were associated with early age at seizure onset (p = 0.048) and appeared in ipsilateral synaptically connected regions from the lesion area.

CONCLUSIONS

Three-dimensional surface-rendered FMZ PET is able to delineate perilesional epileptic cortex, and it may be especially useful to localize such areas in patients with extensive perilesional glucose hypometabolism associated with a large number of seizures. Remote FMZ PET abnormalities in patients with early onset and long duration of epilepsy might represent secondary epileptogenesis, but this requires further study.

Effect of motor tasks on the cortical topography of the human masseter muscle

Non-invasive magnetic stimulation of the brain was earlier used to reveal the corticomotor representation of the human masseter muscle but it is unclear how motor tasks affect this map. An experimental approach incorporating transcranial magnetic stimulation of verified locations on the scalp, surface electromyography, and controlled muscle facilitation was used to disclose the corticomotor output map of the masseter during three isometric tooth-contact tasks, viz., tooth clenching in the intercuspal position, biting on the left molar teeth, and biting on the incisors. Map area was significantly different for all tasks, and map height and volume were also different for biting on the incisor teeth (p<0.05). There was evidence of task-related modulation of corticobulbar activity that appeared to be mainly of corticomotoneuronal origin, although the role of differential, task-associated peripheral afferent input from orofacial receptors could not be discounted.

Is epileptogenic cortex truly hypometabolic on interictal positron emission tomography?

Positron emission tomography (PET) of glucose metabolism is often applied for the localization of epileptogenic brain regions, but hypometabolic areas are often larger than or can miss epileptogenic cortex in nonlesional neocortical epilepsy. The present study is a three-dimensional brain surface analysis designed to demonstrate the functional relation between glucose PET abnormalities and epileptogenic cortical regions. Twelve young patients (mean age, 10.8 years) with intractable epilepsy of neocortical origin underwent chronic intracranial electroencephalographic monitoring. The exact location of the subdural electrodes was determined on high-resolution three-dimensional reconstructed magnetic resonance imaging scan volumes. The electrodes were classified according to their locations over cortical areas, which were defined as hypometabolic, normometabolic, or at the border between hypometabolic and normal cortex (metabolic "border zones") based on interictal glucose PET. Electrodes with seizure onset were located over metabolic border zones significantly more frequently than over hypometabolic or normometabolic regions. Seizure spread electrodes also more frequently overlay metabolic border zones than hypometabolic regions. These findings suggest that cortical areas with hypometabolism should be interpreted as regions mostly not involved in seizure activity, although epileptic activity commonly occurs in the surrounding cortex. This feature of hypometabolic cortex is remarkably similar to that of structural brain lesions surrounded by epileptogenic cortex. Cortical areas bordering hypometabolic regions can be highly epileptogenic and should be carefully assessed in presurgical evaluations.

Objective method for localization of cortical asymmetries using positron emission tomography to aid surgical resection of epileptic foci

We designed a semiautomated method for the objective detection of abnormal regions of tracer accumulation in the brain. The purpose of the present study was to examine the diagnostic performance of this method by applying it to patients with clinically intractable epilepsy of unilateral origin; they underwent [F-18] deoxyglucose positron emission tomography (PET) prior to surgical resection of epileptic foci. A semiautomated method for assessment of asymmetries in the brain cortex was developed that compares activity concentrations in homotopic cortical areas. When these differences exceeded a predefined threshold, the areas with lower activity were marked and 3-dimensional surface rendered images were created to guide placement of intracranial electrodes (ECoG) followed by surgical resection. The normal amount of asymmetry between small (0.5-0.7 cm2) homotopic cortical regions was determined as 5.9 +/- 4.0% (mean +/- SD). The false-positive fraction was determined for cutoff thresholds of 1 SD (10%), 1.5 SD (12%), and 2 SD (15%) outside the mean and was found to be 89, 44, and 0%, respectively. The obtained sensitivity-specificity pairs for correct localization of epileptogenic lobes based on the ECoG results were best for the 15% threshold (80/94%, accuracy 0.90). This objective PET method allows the accurate determination of cortical asymmetries, and it proved to be highly efficient in guiding epilepsy surgery.

Multimodality imaging for improved detection of epileptogenic foci in tuberous sclerosis complex

OBJECTIVE

Using interictal alpha-[11C]methyl-l-tryptophan ([11C]AMT) PET scan, the authors have undertaken a quantitative analysis of all tubers visible on MRI or 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) PET, to determine the relationship between [11C]AMT uptake and epileptic activity on EEG.

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder, often associated with cortical tubers and intractable epilepsy. The authors have shown previously that [11C]AMT PET scans show high tracer uptake in some epileptogenic tubers and low uptake in the remaining tubers.

METHODS

Eighteen children, age 7 months to 16 years, were studied. Patients underwent video-EEG monitoring, PET scans of [11C]AMT and [18F]FDG, and T2-weighted or fluid-attenuated inversion recovery (FLAIR) MRI. [11C]AMT uptake values were measured in 258 cortical tubers delineated with coregistered MRI or [18F]FDG scans. Uptake ratios were calculated between the [11C]AMT uptake in tubers and those for normal cortex (tuber/normal cortex). Using the region of epileptiform activity, the authors performed receiver operator characteristics (ROC) analysis and determined the optimal uptake ratio for detecting presumed epileptogenic tubers.

RESULTS

Tuber uptake ratios ranged from 0.6 to 2.0. Tuber uptake ratios in the epileptic lobes were higher than those in the nonepileptic lobes (p < 0.0001). All 15 patients with focal seizure activity showed one or more lesions with uptake ratio above 0.98 in the epileptic lobe. ROC analysis showed that a tuber uptake ratio of 0.98 resulted in a specificity of 0.91.

CONCLUSIONS

Cortical tubers with [11C]AMT uptake greater than or equal to normal cortex are significantly related to epileptiform activity in that lobe. Together, interictal [11C]AMT PET and FLAIR MRI improve the detection of potentially epileptogenic tubers in patients with TSC being evaluated for epilepsy surgery.

An examination of the sensitivity of reported trends in childhood leukemia incidence rates to geographic location and diagnostic coding (United States)

BACKGROUND

There have been conflicting reports of increased incidence of childhood leukemia in the United States with some, but not other, registries reporting increasing rates over the past two decades. Because of the reported discrepancy in childhood leukemia incidence rates an analysis of the SEER database was undertaken.

METHODS

The latest SEER data (1973-1995) were analyzed for trends in childhood (age 0-14) leukemia incidence rates by histologic group (all leukemia combined, acute lymphocytic leukemia (ALL), acute mylogenous leukemia (AML), and other acute leukemia) for each SEER reporting region.

RESULTS

A significant increase in ALL during 1973-1995 was observed in the combined SEER data, but the increase was a function of whether the first 3 years, data from the SEER Detroit reporting region are included. For the years 1973-1975 the Detroit region reported to much lower rates for ALL and much higher rates for "other acute leukemias" relative to the other SEER regions, resulting in an exaggerated temporal increase in ALL.

CONCLUSION

Excluding both the temporal variability, and coding differences for Detroit in the 1973-1975 time frame, there has been no significant increase in childhood leukemia of any histologic group or age category in the United States from the 1970s to 1990s.

Evaluating nursing administration instruments

OBJECTIVE

To identify and evaluate available measures that can be used to examine the effects of management innovations in five important areas: autonomy, conflict, job satisfaction, leadership, and organizational climate.

BACKGROUND

Management interventions target the context in which care is delivered and through which evidence for practice diffuses. These innovations need to be evaluated for their effects on desired outcomes. However, busy nurses may not have the time to locate, evaluate, and select instruments to measure expected nursing administration outcomes without research-based guidance. Multiple and complex important contextual variables need psychometrically sound and easy-to-use measurement instruments identified for use in both practice and research.

METHOD

An expert focus group consensus methodology was used in this evaluation research to review available instruments in the five areas and evaluate which of these instruments are psychometrically sound and easy to use in the practice setting.

RESULTS

The result is a portfolio of measures, clustered by concept and displayed on a spreadsheet. Retrieval information is provided. The portfolio includes the expert consensus judgment as well as useful descriptive information.

CONCLUSIONS

The research reported here identifies psychometrically sound and easy-to-use instruments for measuring five key variables to be included in a portfolio. The results of this study can be used as a beginning for saving time in instrument selection and as an aid for determining the best instrument for measuring outcomes from a clinical or management intervention.