HL-1 cells are currently the only cardiomyocyte cell line available that continuously divides and spontaneously contracts while maintaining a differentiated cardiac phenotype. Extensive characterization using microscopic, genetic, immunohistochemical, electrophysiological, and pharmacological techniques has demonstrated how similar HL-1 cells are to primary cardiomyocytes. In the few years that HL-1 cells have been available, they have been used in a variety of model systems designed to answer important questions regarding cardiac biology at the cellular and molecular levels. Whereas HL-1 cells have been used to study normal cardiomyocyte function with regard to signaling, electrical, metabolic, and transcriptional regulation, they have also been used to address pathological conditions such as hypoxia, hyperglycemia-hyperinsulinemia, apoptosis, and ischemia-reperfusion. The availability of an immortalized, contractile cardiac cell line has provided investigators with a tool for probing the intricacies of cardiomyocyte function. In this review, we describe the culture and characterization of HL-1 cardiomyocytes as well as various model systems that have been developed using these cells to gain a better understanding of cardiac biology at the cellular and molecular levels.

Summary 1.Dispersal is fundamental to ecological processes at all scales and levels of organization, but progress is limited by a lack of information about the general shape and form of plant dispersal kernels. We addressed this gap by synthesizing empirical data describing seed dispersal and fitting general dispersal kernels representing major plant types and dispersal modes. 2. A comprehensive literature search resulted in 107 papers describing 168 dispersal kernels for 144 vascular plant species. The data covered 63 families, all the continents except Antarctica, and the broad vegetation types of forest, grassland, shrubland and more open habitats (e.g. deserts). We classified kernels in terms of dispersal mode (ant, ballistic, rodent, vertebrates other than rodents, vehicle or wind), plant growth form (climber, graminoid, herb, shrub or tree), seed mass and plant height. 3. We fitted 11 widely used probability density functions to each of the 168 data sets to provide a statistical description of the dispersal kernel. The exponential power (ExP) and log-sech (LogS) functions performed best. Other 2-parameter functions varied in performance. For example, the lognormal and Weibull performed poorly, while the 2Dt and power law performed moderately well. Of the single-parameter functions, the Gaussian performed very poorly, while the exponential performed better. No function was among the best-fitting for all data sets. 4. For 10 plant growth form/dispersal mode combinations for which we had >3 data sets, we fitted ExP and LogS functions across multiple data sets to provide generalized dispersal kernels. We also fitted these functions to subdivisions of these growth form/dispersal mode combinations in terms of seed mass (for animal-dispersed seeds) or plant height (wind-dispersed) classes. These functions provided generally good fits to the grouped data sets, despite variation in empirical methods, local conditions, vegetation type and the exact dispersal process. 5. Synthesis. We synthesize the rich empirical information on seed dispersal distances to provide standardized dispersal kernels for 168 case studies and generalized kernels for plant growth form/ dispersal mode combinations. Potential uses include the following: (i) choosing appropriate dispersal functions in mathematical models; (ii) selecting informative dispersal kernels for one's empirical study system; and (iii) using representative dispersal kernels in cross-taxon comparative studies.

ObjectivesNodding syndrome is a devastating neurological disorder of uncertain aetiology affecting children in Africa. There is no diagnostic test, and risk factors and symptoms that would allow early diagnosis are poorly documented. This study aimed to describe the clinical, electrophysiological and brain imaging (MRI) features and complications of nodding syndrome in Ugandan children.DesignCase series.Participants22 children with nodding syndrome brought to Mulago National Referral Hospital for assessment.Outcome measuresClinical features, physical and functional disabilities, EEG and brain MRI findings and a staging system with a progressive development of symptoms and complications.ResultsThe median age of symptom onset was 6 (range 4–10) years and median duration of symptoms was 8.5 (range 2–11) years. 16 of 22 families reported multiple affected children. Physical manifestations and complications included stunting, wasting, lip changes and gross physical deformities. The bone age was delayed by 2 (range 1–6) years. There was peripheral muscle wasting and progressive generalised wasting. Four children had nodding as the only seizure type; 18 in addition had myoclonic, absence and/or generalised tonic–clonic seizures developing 1–3 years after the onset of illness. Psychiatric manifestations included wandering, aggression, depression and disordered perception. Cognitive assessment in three children demonstrated profound impairment. The EEG was abnormal in all, suggesting symptomatic generalised epilepsy in the majority. There were different degrees of cortical and cerebellar atrophy on brain MRI, but no hippocampal changes. Five stages with worsening physical, EEG and brain imaging features were identified: a prodrome, the development of head nodding and cognitive decline, other seizure types, multiple complications and severe disability.ConclusionsNodding syndrome is a neurological disorder that may be characterised as probably symptomatic generalised epilepsy. Clinical manifestations and complications develop in stages which might be useful in defining treatment and rehabilitation. Studies of risk factors, pathogenesis, management and outcome are urgently needed.

Summary1. Seed predation of 12 fleshy-fruited species was recorded in experimental dishes under early successional forest in south-west Germany (four seasons 1992 and 1993) and in south England (summer 1995). On each occasion, 200 dishes were laid out, each containing five seeds of a given species. The mean time for three or more seeds to be removed was taken as a measure of granivore preferences. We tested correlations of these preferences with several physical and nutritional seed traits. 2. Live trapping and selectively accessible dishes indicated that rodents were the major granivores (Apodemus sylvaticus, Apodemus flavicollis, Clethrionomys glareolus); no predation by birds or insects was observed. The rank order of the rodents' seed preferences was consistent among sites, seasons and years, but mean predation differed between species, sites and seasons. Seed predation was highest in summer and lowest in winter. Possible implications of the seasonal pattern in predation risk are discussed. 3. The preferences of rodents were significantly correlated with the species-specific viability of seeds (i.e. percentage of sound seed) in five of eight experiments and with the percentage of water in the embryo-plus-endosperm fraction (EEF) in four of eight experiments. Surprisingly, preferences were not correlated to seed mass, EEF mass or nitrogen concentration. Predation was lowest among toxic species (Berberis vulgaris, Euonymus europaeus, Sambucus nigra) and among species with woody endocarps (Cornus sanguinea, Crataegus spp.).

SUMMARY Purpose Epilepsy is common in sub-Saharan Africa (SSA), but the clinical features and consequences are poorly characterized. Most studies are hospital-based and few studies have compared different ecological sites in SSA. We described active convulsive epilepsy (ACE) identified in cross-sectional community-based surveys in SSA, to understand the proximate causes, features, and consequences. Methods We performed a detailed clinical and neurophysiological description of ACE cases identified from a community survey of 584,586 people using medical history, neurological examination and electroencephalograph (EEG) data from five sites in Africa: South Africa; Tanzania; Uganda; Kenya and Ghana. The cases were examined by clinicians to discover risk factors, clinical features, and consequences of epilepsy. We used logistic regression to determine the epilepsy factors associated with medical comorbidities. Key findings Half (51%) of the 2,170 people with ACE were children and 69% of seizures began in childhood. Focal features (EEG, seizure types and neurological deficits) were present in 58% of ACE cases, and varied significantly with site. Status epilepticus occurred in 25% of people with ACE. Only 36% received antiepileptic drugs (phenobarbital was the commonest drug (95%)), and the proportion varied significantly with the site. Proximate causes of ACE were adverse perinatal events (11%) for onset of seizures before 18 years; acute encephalopathy (10%) and head injury prior to seizure-onset (3%). Important comorbidities were malnutrition (15%), cognitive impairment (23%) and neurological deficits (15%). The consequences of ACE were burns (16%), head injuries (post seizures) (1%), lack of education (43%) and being unmarried (67%) or unemployed (57%) in adults; all significantly more common than those without epilepsy. Significance There were significant differences in the co-morbidities across sites. Focal features are common in ACE suggesting identifiable and preventable causes. Malnutrition, cognitive and neurological deficits are common in people with ACE and should be integrated into the management of epilepsy in this region. Consequences of epilepsy such as burns, lack of education, poor marriage prospects and unemployment need to be addressed.