Test of recrudescence hypothesis for overwintering of West Nile virus in gray catbirds

West Nile virus is a pathogen of concern for both human and wildlife health. Although many aspects of the ecology of West Nile virus are well understood, the mechanisms by which this and similar mosquito-borne viruses overwinter and become reinitiated each spring in temperate regions is not known. A thorough understanding of this mechanism is crucial to risk assessment and development of control strategies. One of the hypotheses to explain the mechanism by which this virus persists from year to year is the spring recrudescence of latent virus in avian reservoir hosts. Stress-related immunosuppression is implicated in the recrudescence of latent viruses in birds. We tested the spring recrudescence hypothesis in a controlled laboratory experiment using hatching-year gray catbirds (Dumatella carolinensis) captured in northern Ohio (July-August 2006). Catbirds (n = 60) were experimentally infected (September 2006) and later examined for the effects of immunosuppression through exogenous hormones and artificially induced migratory disposition. We found no effect of either testosterone or migratory behavior on infection status in any of the treatment birds. Moreover, we detected no viral RNA in the kidney, spleen, brain, or liver upon necropsy at 24 wk postinfection.

Effect of informational internet web pages on patients' decision-making: randomised controlled trial regarding choice of spinal or general anaesthesia for orthopaedic surgery

This study explored whether patients' preference for particular types of anaesthesia could be influenced pre-operatively by giving them the addresses of various relevant websites. Patients at an orthopaedic pre-assessment education clinic completed a questionnaire, which included a short multiple-choice general knowledge quiz about anaesthesia, and also questioned them as to their choice of anaesthesia (general or neuraxial). Patients were randomly assigned to intervention or control groups. Intervention group members were given the addresses of three relevant anaesthesia and health related websites to access at home. All patients were asked to complete the questionnaires on a second occasion, before surgery. Initially, most patients stated a preference for general anaesthesia. Subsequently, the intervention group altered their preference towards neuraxial anaesthesia compared to the control group (p < or = 0.0001). The increase in median (IQR [range]) anaesthesia knowledge test score was greater in the intervention group (from 10.0 (9.0-12.0 [5.0-14.0]) to 13.0 (11.0-14.0 [6.0-14.0])) than in the control group (from 10.0 (9.0-11.5 [3.0-13.0]) to 11.0 (9.0-12.0 [4.0-14.0]); p = 0.0068).

The size of the spleen by magnetic resonance imaging in patients with cystic fibrosis; with and without diabetes--a novel observational study

BACKGROUND

Magnetic resonance imaging (MRI) has been shown to be a useful tool to evaluate the volume of the pancreas. There is currently no information about the size of the spleen in cystic fibrosis (CF) patients.

PATIENTS AND METHODS

We investigated 51 adult volunteers: 28 pancreatic insufficient CF patients [13 with CF-related diabetes (CFRD) and 15 non-diabetic] and 23 male non-CF patients [12 with type 1 diabetes mellitus (T1DM) and 11 healthy control subjects]. Patients with known liver cirrhosis or portal hypertension were excluded. The size of the spleen was measured in all subjects by an investigator unaware of patients' clinical status. For comparison of spleen size in the four study groups only male CF patients were included. For CF patients, spleen size was compared with forced expiratory volume in 1 s (FEV(1)), body mass index (BMI), total number of days of intravenous (IV) antibiotic treatment for pulmonary exacerbations in year previous to study, levels of circulating white blood cells, glycosylated haemoglobin A1c (HbA1c), and exocrine function of the pancreas, as assessed by daily requirement of oral lipase.

RESULTS

Amongst the four study groups, spleen size was greatest in the male non-diabetic CF patients (P = 0.01). For CF patients, spleen size was greater in male compared to female patients (P = 0.012). For patients with CFRD, there was an inverse correlation between the spleen size and HbA1c (r = -0.59, P = 0.04) and the daily intake of supplementary lipase (r = -0.63, P = 0.02). The size of the spleen in patients with CFRD, but not in CF patients without CFRD, inversely correlated with the days of IV antibiotic treatment received in the year previous to the study (r = -0.67, P = 0.012). There was no correlation between spleen size and BMI, FEV1 and white blood cell counts in any group.

CONCLUSION

On MRI, the spleen size was greatest in male non-diabetic CF patients in comparison with other groups. The size of the spleen in CFRD patients was smaller when diabetes was poorly controlled, when exocrine pancreatic function was greatly impaired and in those with greater need for IV antibiotics in the year prior to the study.

Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator

Bi2Se3 is one of a handful of known topological insulators. Here we show that copper intercalation in the van der Waals gaps between the Bi2Se3 layers, yielding an electron concentration of approximately 2x10{20} cm{-3}, results in superconductivity at 3.8 K in CuxBi2Se3 for 0.12<or=x<or=0.15. This demonstrates that Cooper pairing is possible in Bi2Se3 at accessible temperatures, with implications for studying the physics of topological insulators and potential devices.

Increased accuracy of batch fecundity estimates using oocyte stage ratios in Plectropomus leopardus

Using the ratio of the number of migratory nuclei to hydrated oocytes to estimate batch fecundity of common coral trout Plectropomus leopardus increases the time over which samples can be collected and, therefore, increases the sample size available and reduces biases in batch fecundity estimates.

Tetragonal-to-orthorhombic structural phase transition at 90 K in the superconductor Fe(1.01)Se

In this Letter we show that superconducting Fe(1.01)Se undergoes a structural transition at 90 K from a tetragonal to an orthorhombic phase but that nonsuperconducting Fe(1.03)Se does not. High resolution electron microscopy at low temperatures further reveals an unexpected additional modulation of the crystal structure of the superconducting phase that involves displacements of the Fe atoms, and that the nonsuperconducting composition shows a different, complex nanometer-scale structural modulation. Finally, we show that magnetism is not the driving force for the phase transition in the superconducting phase.

The metal-insulator transition in Fe(1.01-x)Cu(x)Se

Iron selenide, Fe(1.01)Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8 K. Here we show that copper can be substituted at the iron site in Fe(1.01)Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe(2) structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12% doping, where a spin-glass transition near 15 K is observed.

Physiological consequences of the P2328S mutation in the ryanodine receptor (RyR2) gene in genetically modified murine hearts

Aim

To explore the physiological consequences of the ryanodine receptor (RyR2)-P2328S mutation associated with catecholaminergic polymorphic ventricular tachycardia (CPVT).

Methods

We generated heterozygotic (RyR2^p/s) and homozygotic (RyR2^s/s) transgenic mice and studied Ca²⁺ signals from regularly stimulated, Fluo-3-loaded, cardiac myocytes. Results were compared with monophasic action potentials (MAPs) in Langendorff-perfused hearts under both regular and programmed electrical stimulation (PES).

Results

Evoked Ca²⁺ transients from wild-type (WT), heterozygote (RyR2^p/s) and homozygote (RyR2^s/s) myocytes had indistinguishable peak amplitudes with RyR2^s/s showing subsidiary events. Adding 100 nm isoproterenol produced both ectopic peaks and subsidiary events in WT but not RyR2^p/s and ectopic peaks and reduced amplitudes of evoked peaks in RyR2^s/s. Regularly stimulated WT, RyR2^p/s and RyR2^s/s hearts showed indistinguishable MAP durations and refractory periods. RyR2^p/s hearts showed non-sustained ventricular tachycardias (nsVTs) only with PES. Both nsVTs and sustained VTs (sVTs) occurred with regular stimuli and PES with isoproterenol treatment. RyR2^s/s hearts showed higher incidences of nsVTs before but mainly sVTs after introduction of isoproterenol with both regular stimuli and PES, particularly at higher pacing frequencies. Additionally, intrinsically beating RyR2^s/s showed extrasystolic events often followed by spontaneous sVT.

Conclusion

The RyR2-P2328S mutation results in marked alterations in cellular Ca²⁺ homeostasis and arrhythmogenic properties resembling CPVT with greater effects in the homozygote than the heterozygote demonstrating an important gene dosage effect.

Applying computer-assisted structure elucidation algorithms for the purpose of structure validation: revisiting the NMR assignments of hexacyclinol

Computer-assisted structure elucidation (CASE) using a combination of 1D and 2D NMR data has been available for a number of years. These algorithms can be considered as "logic machines" capable of deriving all plausible structures from a set of structural constraints or "axioms", defined by the spectroscopic data and associated chemical information or prior knowledge. CASE programs allow the spectroscopist not only to determine structures from spectroscopic data but also to study the dependence of the proposed structure on changes to the set of axioms. In this article, we describe the application of the ACD/Structure Elucidator expert system to help resolve the conflict between two different hypothetical hexacyclinol structures derived by different researchers from the NMR spectra of this complex natural product. It has been shown that the combination of algorithms for both structure elucidation and structure validation delivered by the expert system enables the identification of the most probable structure as well as the associated chemical shift assignments.

Performance validation of neural network based (13)c NMR prediction using a publicly available data source

The validation of the performance of a neural network based 13C NMR prediction algorithm using a test set available from an open source publicly available database, NMRShiftDB, is described. The validation was performed using a version of the database containing ca. 214,000 chemical shifts as well as for two subsets of the database to compare performance when overlap with the training set is taken into account. The first subset contained ca. 93,000 chemical shifts that were absent from the ACD\CNMR DB, the "excluded shift set" used for training of the neural network and the ACD\CNMR prediction algorithm, while the second contained ca. 121,000 shifts that were present in the ACD\CNMR DB training set, the "included shift set". This work has shown that the mean error between experimental and predicted shifts for the entire database is 1.59 ppm, while the mean deviation for the subset with included shifts is 1.47 and 1.74 ppm for excluded shifts. Since similar work has been reported online for another algorithm we compared the results with the errors determined using Robien's CNMR Neural Network Predictor using the entire NMRShiftDB for program validation.

Field investigation of perinatal mortality in friesian cattle associated with myocardial degeneration and necrosis

Perinatal mortality and stillbirths were investigated in an extensively managed herd of Friesian cows and heifers calving over a 2-year period: 504 cows were calved and 215 heifers. Cows were bred to Friesian and Jersey bulls using natural service. The perinatal fetal mortality rate was 7.5% for cows and 30% for heifers. An experienced stockman managed these calvings and veterinary assistance was required only on nine occasions. All stillborn fetuses were examined post-mortem by the Veterinary Laboratories Agency, Carmarthen and no infectious agent was identified on any occasion. Thyroid hyperplasia was found in two fetuses. In blood samples taken from 10 late pregnant heifers, mean glutathione peroxidase values were 7.9 +/- 1.7 IU/ml Packed Cell Volume (PCV). Tissues from eight fetuses were submitted to the University of Liverpool for histopathological examination; all presented lesions consistent with myocardial degeneration and necrosis of the left ventricle. Following treatment of 205 late pregnant heifers with sodium selenite and vitamin E, the overall perinatal mortality rate in these cattle fell to below 11%.

Identification of metabolites produced from N-phenylpiperazine by Mycobacterium spp

Mycobacterium sp. 7E1B1W and seven other mycobacterial strains known to degrade hydrocarbons were investigated to determine their ability to metabolize the piperazine ring, a substructure found in many drugs. Cultures were grown at 30 degrees C in tryptic soy broth and dosed with 3.1 mM N-phenylpiperazine hydrochloride; samples were removed at intervals and extracted with ethyl acetate. Two metabolites were purified from each of the extracts by high-performance liquid chromatography; they were identified by mass spectrometry and (1)H nuclear magnetic resonance spectroscopy as N-(2-anilinoethyl)acetamide and N-acetyl-N'-phenylpiperazine. The results show that mycobacteria have the ability to acetylate piperazine rings and cleave carbon-nitrogen bonds.

The range and nature of sleep dysfunction in untreated Parkinson's disease (PD). A comparative controlled clinical study using the Parkinson's disease sleep scale and selective polysomnography

In this study we have explored the nature and range of sleep dysfunction that occurs in untreated Parkinson's disease (PD) comparing data obtained from the use of the Parkinson's disease sleep scale (PDSS) in an untreated PD patient group compared to advanced PD and healthy controls. 25 untreated (drug-naive, DNPD) PD patients (mean age 66.9 years, range 53-80, 18 males) completed the validated Parkinson's disease sleep scale (PDSS), mean duration of PD was 2.1 years (1-10, up to 4 years in all except one patient with tremulous PD reporting tremor duration of 10 years) and mean Hoehn and Yahr score 1.9 (1-3). Data were compared to 34 advanced PD (mean age 70.2 years, range 51-88, 23 male), mean duration of PD 11 years (range 4-22), mean Hoehn and Yahr score 3.4 (3-5) and PDSS data obtained from 131 healthy controls (mean age 66.6 years, range 50-93, 56 males). Total PDSS scores and PDSS sub-items, except PDSS item 2, were highly significantly different (p<0.001) between DNPD, advanced PD and controls. Controls reported higher mean PDSS scores than both groups of patients, and advanced cases reported lower (mean+/-S.D.) PDSS scores (86.95+/-20.78) than drug-naive (105.72+/-21.5) (p<0.001). Logistic regression analysis showed that items PDSS8 (nocturia), PDSS11 (cramps), PDSS12 (dystonia), PDSS13 (tremor), and PDSS15 (daytime somnolence) were significantly impaired in DNPD compared to controls while PDSS7 (nighttime hallucinations) additionally separated advanced PD from DNPD. In a subgroup of 11 advanced PD cases (mean age 62 years, range=49-84 years, mean Hoehn and Yahr score 2.5, range=1-3) with high Epworth Sleepiness Scale (ESS) scores (mean 14.5), low item 15 PDSS score (mean 4.7) and complaints of severe daytime sleepiness, underwent detailed overnight polysomnography (PSG) studies, all showing abnormal sleep patterns. We conclude that nocturia, nighttime cramps, dystonia, tremor and daytime somnolence seem to be the important nocturnal disabilities in DNPD and some of these symptoms may be reminiscent of "off" period related symptoms even though patients are untreated. Furthermore, polysomnography in "sleepy" PD patients may help diagnose unrecognised conditions such as periodic limb movement of sleep (PLMS), obstructive sleep apnoea (OSA) and REM Sleep Behaviour Disorder.

Effects of thyroid status on bone metabolism: a primary role for thyroid stimulating hormone or thyroid hormone?

Thyroid hormones are essential for normal skeletal growth and the maintenance of bone mass in adulthood, although their mechanism of action in bone is poorly understood. Hypothyroidism causes impaired bone formation and growth retardation whereas thyrotoxicosis results in accelerated growth, advanced bone age and decreased bone mass. Adults with thyrotoxicosis or a suppressed thyroid stimulating hormone (TSH) from any cause have an increased risk of osteoporotic fracture. Conventionally, bone loss in thyrotoxicosis has been regarded as a direct consequence of thyroid hormone excess acting locally on bone. Recently, however, it has been proposed that TSH may be a direct negative regulator of bone turnover acting via the TSH receptor on both osteoblasts and osteoclasts. Thus, TSH deficiency could be partly responsible for the skeletal loss seen in thyrotoxicosis. Here we provide an overview of the molecular actions of thyroid hormone in bone and discuss in detail the current evidence relating to a possible role for TSH in bone metabolism.

Hepatitis B vaccination in predialysis chronic renal failure patients a comparison of two vaccination schedules

To improve seroconversion to hepatitis B vaccination, it is recommended that patients suffering with chronic renal failure be vaccinated as soon as dialysis is anticipated. We compared seroconversion rates in 121 predialysis patients with moderate chronic renal failure using either 40 or 20 microg of Engerix B recombinant hepatitis B vaccine administered at 0, 1 and 6 months. Seroconversion was not significantly higher after three doses of 40 microg (67%) compared to 20 microg (57%, p=0.27). Multivariable analysis using dose of vaccine, eGFR (MDRD equation), calculated creatinine clearance (Cockcroft--Gault), and age as independent continuous variables showed that neither dose nor degree of renal function contributed to seroconversion. Younger age was weakly associated with improved seroconversion (p=0.052). Seroconversion was attained in 13% of non-responders after a fourth dose of vaccine.

Analysis of an adult Duchenne muscular dystrophy population

BACKGROUND

Advances in management have led to increasing numbers of patients with Duchenne muscular dystrophy (DMD) reaching adulthood. Older patients with DMD are necessarily severely disabled, and their management presents particular practical issues.

AIM

To review the management of a late adolescent and adult DMD population, and to identify areas in which the present service provisions may be inadequate to their needs.

DESIGN

Retrospective review.

METHODS

We studied 25 patients with DMD referred to an adult neuromuscular clinic over a 7-year period. Clinical details were obtained retrospectively, from case notes or direct observations.

RESULTS

There were 24 males and one symptomatic female carrier. Nine patients died during the observation period. There was no significant correlation between age of wheelchair confinement and age of death. Sixteen patients received non-invasive positive pressure support. Twelve attended mainstream schools and 12, residential special schools. All the patients lived at home for some or all of the time, when their main carers were either one or both of the parents. The most striking difficulties were with the provision of practical aids, including appropriate hoists and belts, feeding and toileting aids, and the conversion of accommodation. Patients rarely wished to discuss the later stages of their disease, and death was often more precipitate than expected. Death usually occurred outside hospital and the final cause was often difficult to establish.

DISCUSSION

Adult patients with DMD develop progressive impairment, due to respiratory, orthopaedic and general medical factors. However, the particular areas of difficulty in this study often reflected inadequate and poorly directed social and medical support, illustrating the need for improvements in the structure, co-ordination and breadth of rehabilitation services for adult patients with DMD.

Down-regulation of the sodium channel Na(v)1.1 alpha-subunit following focal ischemic brain injury in rats: in situ hybridization and immunohistochemical analysis

Change in sodium channel (NaCh) activity can play a role in reorganization, recovery, or possibly excitotoxic damage after CNS injury. Alteration of sodium channel function has been reported to occur in a variety of neuropathological states including epilepsy and brain injury. Previously we reported that out of five NaCh alpha subunit genes that were down-regulated, Na(v)1.1 exhibited the most dramatic and sustained alterations following focal cerebral ischemia in the rat. In the present study, we evaluated the acute spatial and temporal time course distribution of Na(v)1.1 mRNA (in situ hybridization) and protein (immunohistochemistry) following ischemic brain injury. Male rats were subjected to 2 h of middle cerebral artery occlusion (MCAo) followed by reperfusion and brain tissue was collected at 2, 6, 24, and 48 h post-MCAo. Analysis of brain tissue revealed a qualitative drop in both mRNA and protein levels of Na(v)1.1 throughout ischemic regions, beginning at the early stage of injury (6 h) with dramatic losses at later stages (24 and 48 h). Quantitative cell counts and optical density measurements indicated significant decreases in the percent of brain cells immunoreactive for Na(v)1.1 as well as a loss of signal in those cells positive for Na(v)1.1 in the injured cortex and striatum as compared to the contralateral hemisphere. Double labeling with NeuN and Na(v)1.1 immunoflouresence confirmed that the predominate loss of Na(v)1.1 immunoreactivity was in neurons. In conclusion, these data map the time-dependent loss of Na(v)1.1 mRNA and protein following focal ischemic brain injury in the rat out to 48 h post-injury.

The association between narcolepsy and REM behavior disorder (RBD)

BACKGROUND AND PURPOSE

Rapid eye movement (REM) sleep Behavior Disorder (RBD) is a movement disorder associated with loss of REM-related muscle atonia and is characterized by complex, vigorous and frequently violent dream-enacting behavior during REM sleep. RBD is usually idiopathic or secondary to neurological problems such as Parkinson's disease. This study looked at the association of RBD with another sleep disorder, narcolepsy.

PATIENTS AND METHODS

Seventy-eight questionnaires were sent to known narcoleptics chosen at random from those with contact details available at the center. The questionnaire addressed current narcolepsy symptoms, medication use and symptoms of RBD. Positive questionnaire results were followed up with a telephone interview. Limited polysomnography (PSG) data was also analyzed.

RESULTS

Fifty-five patients responded (response rate 71%). Of these, 20 (36%) had symptoms suggestive of RBD. The typical RBD patient is an older male (mean age of onset 60.9 years, 87% male); however, in this study, females were as likely to have RBD as males, and the mean age was 41 years. Sixty-eight percent of patients who regularly experienced cataplexy and the associated symptoms of narcolepsy (sleep paralysis, hypnogogic hallucinations and automatic behavior) had RBD, compared to 14% of those who never or rarely experienced these symptoms.

CONCLUSION

This study implies a stronger relationship between these disorders than a previously published figure of 7-12% This is clinically significant as RBD is a potentially distressing but readily treatable disorder. It follows that narcoleptics, especially those with cataplexy and other associated symptoms, should be questioned about symptoms of RBD and treated accordingly. Similarly, anyone presenting with RBD should be assessed for symptoms of narcolepsy, particularly if female or of a younger age group than would otherwise be expected.

Outcomes, cost and long term survival of patients referred to a regional weaning centre

BACKGROUND

Regional weaning centres provide cost effective care for patients who have undergone prolonged mechanical ventilation. There are few published European data on outcomes in these patients.

METHODS

Patients admitted for weaning to the Lane Fox Respiratory Unit (LFU) between January 1997 and December 2000 were identified. The proportion weaned from mechanical ventilation, in-hospital mortality, and subsequent survival after discharge were examined.

RESULTS

A total of 153 patients had been ventilated for a median of 26 days before transfer. The daily cost per patient stay was 1350. Fifty eight patients (38%) were fully weaned, 42 (27%) died, and 53 (35%) required ventilatory support at discharge from hospital of whom 36 (24%) required only nocturnal ventilation. Univariate analysis showed increasing age (OR 1.06, p<0.001), length of ICU stay (OR 1.02, p = 0.001), APACHE II predicted risk of death score (OR 1.02, p = 0.05), and a surgical cause for admission (OR 4.04) were associated with mortality. Neuromuscular/chest wall conditions were associated with low mortality (OR 0.36) but low likelihood of weaning from ventilation (OR 0.28). Female sex (OR 2.13, p = 0.03) and COPD (OR 2.81) were associated with successful weaning. Overall survival at 3 years from admission was 47%. Long term survival was lowest in patients with COPD.

CONCLUSIONS

Most patients survived to leave hospital, the majority having been liberated from ventilatory support. Survivors were younger and spent less time ventilated in the referring ICU. The underlying diagnosis determined success of weaning, hospital survival, and long term outcome.

Weak charge-lattice coupling requires reinterpretation of stripes of charge order in La1-xCaxMnO3

Modulations in manganites attributed to stripes of charge/orbital/spin order are thought to result from strong electron-lattice interactions that lock the superlattice and parent lattice periodicities. Surprisingly in La1-xCaxMnO3 (x>0.5,90 K), convergent beam (3.6 nm spot) electron diffraction patterns rule out charge stacking faults and indicate a superlattice with uniform periodicity. Moreover, large area electron diffraction peaks are sharper than simulations with stacking faults. Since the electron-lattice coupling does not lock the two periodicities (to yield stripes) it may be too weak to strongly localize charge.

Multiple system atrophy presenting as central sleep apnoea: Fig. 1.—

A 61-yr-old male presented with apparent idiopathic central sleep apnoea but after 4 yrs developed features of autonomic, cerebellar and extrapyramidal dysfunction consistent with a diagnosis of multiple system atrophy (MSA). Though central sleep apnoea can occur in multiple sleep apnoea, it is less frequent than obstructive sleep apnoea and occurs in the later stages of the disease. The pathogenesis of MSA involves gliosis and neuronal cell loss in specific areas of the central nervous system. Central sleep apnoea in MSA may be due to the depletion of cholinergic neurons in the arcuate nucleus of the medulla by apoptosis. This is the first description of multiple system atrophy presenting as central sleep apnoea. The current authors believe that multiple system atrophy should be considered in the differential diagnosis of late onset central sleep apnoea and progressive hypoventilation.

Rocking bed and prolonged independence from nocturnal non-invasive ventilation in neurogenic respiratory failure associated with limb weakness

A 40 year old mother of three with autosomal dominant scapuloperoneal muscular dystrophy presented with severe neurogenic respiratory failure requiring nocturnal non-invasive ventilation (NIV). Because of the development of profound proximal muscular weakness as a consequence of the progressive nature of her neurological disease, she eventually was unable to apply and remove the facial interface to set up her NIV circuit. She therefore became dependent on her children and carers to start and stop NIV during the night. A rocking bed was successfully employed as an alternative to nocturnal NIV. Ventilation was facilitated by the passive movement of the diaphragm as a consequence of the movement of the abdominal contents under the effect of gravity. Benefit was demonstrated objectively by pulse oximetry and subjectively by the improvement in the patient's symptomatology and continued independence at night. The ease of use of a rocking bed should be borne in mind when the necessity for nocturnal ventilatory support in neuromuscular disease results in the potential loss of independence for a patient.

Antiepileptic Drug Treatment of Nonconvulsive Seizures Induced by Experimental Focal Brain Ischemia

Nonconvulsive seizures (NCSs) after traumatic and ischemic brain injury are often refractory to antiepileptic drug therapy and are associated with a decline in patient outcome. We recently characterized an in vivo rat model of focal brain ischemia-induced NCS and here sought to evaluate potential pharmacological treatments. Electroencephalographic activity was recorded continuously for 24 h in freely behaving rats subjected to permanent middle cerebral artery occlusion (MCAo). Rats were treated with an antiepileptic drug from one of seven different drug classes at ED(50) and 2x ED(50) doses (as reported in other rat seizure models), delivered as a single i.v. injection 20 min post-MCAo. Vehicle-treated rats (n = 9) had an 89% incidence of NCS with an average number of NCS of 8.6 +/- 1.9. The latency to onset of NCS was 32.5 +/- 3.4 min post-MCAo with an average duration of 49.1 +/- 8.2 s/event. The high doses of ethosuximide, gabapentin, fos-phenytoin, and valproate significantly reduced the incidence of NCS (11, 14, 14, and 38%, respectively), whereas midazolam, phenobarbital, and dextromethorphan had no significant effect at either dose. Across treatment groups, there was a low but significant correlation between the number of NCS events per animal and volume of brain infarction (r = 0.352). Antiepileptic drug therapy that prevented the occurrence of NCS also reduced mortality from 26 to 7%. Based on combined effects on NCS, infarction, neurological recovery, and mortality, ethosuximide and gabapentin were identified as having the best therapeutic profile.