An siRNA screen identifies transmembrane 7 superfamily member 3 (TM7SF3), a seven transmembrane orphan receptor, as an inhibitor of cytokine-induced death of pancreatic beta cells.

AIMS/HYPOTHESIS: Pro-inflammatory cytokines induce death of pancreatic beta cells, leading to the development of type 1 diabetes. We sought to identify novel players and the underlying mechanisms involved in this process. METHODS: A high-throughput screen of 3,850 mouse small interfering RNAs (siRNAs) was performed in cytokine-treated MIN6 beta cells. Cells were transfected with the different siRNAs and then treated with a combination of TNFα, IL-1ß and IFNγ. Cellular apoptosis (caspase-3/7 activity), and changes in cellular reducing power and cell morphology were monitored. The resulting data were analysed and the corresponding z scores calculated. RESULTS: Several gene families were identified as promoting cytokine-induced beta cell apoptosis, the most prominent being those encoding ubiquitin ligases and serine/threonine kinases. Conversely, deubiquitinating enzymes appeared to reduce apoptosis, while protein phosphatases were mainly associated with lowering cellular reducing power. The screen suggested with high confidence the involvement of several novel genes in cytokine-induced beta cell death, including Camkk2, Epn3, Foxp3 and Tm7sf3, which encodes an orphan seven transmembrane receptor. siRNAs to Tm7sf3 promoted cytokine-induced death of MIN6 cells and human pancreatic islets, and abrogated insulin secretion in these cells. These findings implicate transmembrane 7 superfamily member 3 as a potential new player in the inhibition of cytokine-induced death and in the promotion of insulin secretion from pancreatic beta cells. CONCLUSIONS/INTERPRETATION: The signalling pathways and novel genes that we identified in this screen and that mediate beta cell death offer new possible targets for therapeutic intervention in diabetes and its adverse complications.

Transcallosal resection of hypothalamic hamartoma for gelastic epilepsy.

INTRODUCTION: Hypothalamic hamartomas (HHs) are commonly associated with severe epilepsy resistant to anticonvulsant therapy. Historically, surgical resection of HHs resulted in considerable morbidity. DISCUSSION: Two series of patients who successfully underwent resection using a transcallosal approach have now been published; we report the first UK experience of this technique in a series of five patients with HHs and gelastic epilepsy resistant to anticonvulsant therapy. Patients were assessed pre- and postoperatively for seizure activity, endocrine function, ophthalmology, and neurocognitive function. Two patients had precocious puberty and all had evidence of developmental delay and behavioral problems. Postoperatively, all children experienced at least a 50% reduction in seizure frequency with abolition of major seizure types; one child remains seizure-free. One child developed a mild postoperative right hemiparesis and one developed transient diabetes insipidus. CONCLUSION: There were no adverse developmental effects of surgery. Transcallosal resection of HHs ameliorates resistant epilepsy syndromes associated with HH.

Distinct right frontal lobe activation in language processing following left hemisphere injury.

Right hemisphere activation during functional imaging studies of language has frequently been reported following left hemisphere injury. Few studies have anatomically characterized the specific right hemisphere structures engaged. We used functional MRI (fMRI) with verbal fluency tasks in 12 right-handed patients with left temporal lobe epilepsy (LTLE) and 12 right-handed healthy controls to localize language-related activity in the right inferior frontal gyrus (RIFG). During the phonemic task, LTLE patients activated a significantly more posterior region of the right anterior insula/frontal operculum than healthy controls (P = 0.02). Activation of the left inferior frontal gyrus (LIFG) did not differ significantly between the two groups. This suggests that, following left hemisphere injury, language-related processing in the right hemisphere differs from that with a functionally normal left hemisphere. The localization of activation in the left and right inferior frontal gyri was determined with respect to the anatomical sub-regions pars opercularis (Pop), pars triangularis (Ptr) and pars orbitalis (Por). In the LIFG, both healthy controls (8 out of 12) and LTLE patients (9 out of 12) engaged primarily Pop during phonemic fluency. Activations in the RIFG, however, were located mostly in the anterior insula/frontal operculum in both healthy controls (8 out of 12) and LTLE patients (8 out of 12), albeit in distinct regions. Mapping the locations of peak voxels in relation to previously obtained cytoarchitectonic maps of Broca's area confirmed lack of homology between activation regions in the left and right IFG. Verbal fluency-related activation in the RIFG was not anatomically homologous to LIFG activation in either patients or controls. To test more directly whether RIFG activation shifts in a potentially adaptive manner after left hemisphere injury, fMRI studies were performed in a patient prior to and following anatomical left hemispherectomy for the treatment of Rasmussen's encephalitis. An increase in activation magnitude and posterior shift in location were found in the RIFG after hemispherectomy for both phonemic and semantic tasks. Together, these results suggest that left temporal lobe injury is associated with potentially adaptive changes in right inferior frontal lobe functions in processing related to expressive language.

The National General Practice Study of Epilepsy. The syndromic classification of the International League Against Epilepsy applied to epilepsy in a general population.

In this prospective, population-based study of 594 cases of newly diagnosed epilepsy, proportions in categories as defined by the International League Against Epilepsy (ILAE) were as follows: (1) localization-related epilepsies: 1.1* idiopathic, 1.2%; 1.2* symptomatic, 16.2%; and 1.3 cryptogenic, 24.6%; (2) generalized epilepsies: 2.1* idiopathic (idiopathic generalized epilepsy) with 3-Hz spike and wave: absence epilepsy, 2.2%; juvenile myoclonic epilepsy, 1.5%; and nonspecific idiopathic generalized epilepsy, 5.6%; 2.3.1* symptomatic generalized epilepsies, 1.5%; 2.3.2* specific syndromes with generalized epilepsy, 0.3%; 3.2 seizures without unequivocal focal or generalized features, 32%; 4.1 situation-related syndromes, isolated seizures, 9.9%; seizures due to acute toxic or metabolic cause,* 4.5%. Only 33.6% were in diagnostic ILAE categories (asterisks) and many rare syndromes were not represented. The remainder (66.4%) were in various nonspecific categories. Only 24% of localization-related epilepsies could be clinically localized to a single ILAE-proposed site of origin and of these best localized cases, 14% had strongly discordant imaging or electroencephalograms. These major problems in applying the ILAE classification to epilepsy in the general population and its underemphasis of modern imaging techniques are discussed.

National General Practice Study of Epilepsy (NGPSE): partial seizure patterns in a general population.

The National General Practice Study of Epilepsy (NGPSE) is a prospective community-based study of newly diagnosed epileptic seizures. Of 594 patients with definite epileptic seizures, 160 (26.9%) had seizures with a clinically localizable onset: 36 (22.5%) frontal, 52 (32.5%) central sensorimotor, 43 (27%) temporal, nine (5.6%) frontotemporal, and 10 each (6.3%) parietal and other posterior cortex. There was no difference among these groups in seizure frequency or remission rate; 46.5% were seizure free and 6.9% had severe epilepsy. Etiology was identifiable in 41% and focal CT and EEG abnormalities in 33% and 19%, with results discordant with the clinical seizure localization in 21% and 20%. Temporal lobe epilepsy may be underreported, as it may be more difficult to localize clinically. Extratemporal seizures are extremely common in the general population, especially frontal and central sensorimotor, in relation to cerebrovascular disease. Prognoses are similar for partial epilepsies with different clinical patterns and regions of onset and are much better than suggested in hospital-based studies. The clinical, EEG, and CT localizations may frequently be discordant in this nonrefractory group.

Double pathology in Rasmussen's syndrome: a window on the etiology?

The syndrome of chronic encephalitis with epilepsy (Rasmussen's syndrome) typically occurs in children and is characterized by the development of intractable focal seizures, progressive hemiparesis and intellectual deterioration. The etiology is unknown, and the pathological abnormalities vary from those of active disease, with numerous microglial nodules, with or without neuronophagia, perivascular round cells and glial scarring, to those of remote disease, demonstrated by neuronal loss, gliosis and perivascular round cells but few microglial nodules. We describe five patients presenting with clinical features typical of Rasmussen's syndrome, in whom pathological examination showed a second, previously unsuspected pathology in addition to the changes of chronic encephalitis. Two of the patients had vascular abnormalities bearing some resemblance to cavernous angiomata, one had a tumor, one had tuberous sclerosis, and one the forme fruste of tuberous sclerosis. The coexistence of a second pathology in these patients may provide information about the underlying mechanism of this rare condition.

Chronic encephalitis and epilepsy in adults and adolescents: a variant of Rasmussen's syndrome?

Chronic encephalitis and epilepsy (Rasmussen's encephalitis) is a rare progressive disorder of uncertain etiology that usually occurs in children, producing focal epilepsy, hemiparesis, and intellectual deterioration. We identified 13 patients in whom seizures developed in adolescence or adulthood with a pathologic picture of chronic encephalitis. The clinical characteristics were more variable than those occurring in children, with the patients falling into three groups: five patients developed seizures in adulthood, but otherwise showed many resemblances to the childhood form; five developed seizures in adolescence, with similar presentation but rather more benign course than in the younger patients; and three presented with clinical features initially suggestive of a tumor. Occipital onset to the seizures appeared to be more common than in the childhood form, and bilateral disease also occurred.

Medical treatment of Rasmussen's syndrome (chronic encephalitis and epilepsy): effect of high-dose steroids or immunoglobulins in 19 patients.

We treated 19 patients with Rasmussen's syndrome (chronic encephalitis and epilepsy)--a rare progressive disorder of unknown etiology causing focal epilepsy, hemiparesis, and intellectual deterioration--with intravenous immunoglobulins, high-dose steroids, or both, to control seizures and improve the end point of the disease. Ten of 17 patients receiving steroids, and eight of nine patients receiving immunoglobulins, had some reduction of seizure frequency in the short term. Improvement in hemiparesis was slight. The effect of these drugs in ameliorating the end point of the disease in the long term remains unknown, and further multicenter studies with standardized protocols are warranted.

Metabolically stable analogues of substance P: persistent action of partially modified retro-inverso analogues of substance P on rat parotid and hypothalamic slices.

In a search for metabolically stable analogues of substance P (SP) the hexapeptide [pGlu6]SP-(6-11) was modified by reversal of the direction of a single amide bond. This novel peptide modification reverses the direction of the amide bonds at the peptide backbone but attempt to retain the topology of the amino acid side-chains at the peptide surface. The partial retro-inverso modification was successfully applied in a previous study for enkephalin analogues which were found to have potent and protracted morphinomimetic activity both in vivo and in vitro. The partially modified retro-inverso analogues: [pGlu6 psi(NH-CO)(RS)-Phe7]SP-(6-11) (analogue II) and [pGlu6,Phe8 psi(NH-CO)Gly9]SP-(6-11) (analogue III) were tested on guinea-pig ileum and for K+ release from rat parotid slices. Metabolic stability of the analogues was measured by their ability to produce persistent K+ release from parotid slices, their half life time (t1/2) in the rat parotid and hypothalamic slice systems and their resistance to proteolytic cleavage by chymotrypsin, pepsin, papain and pronase. Analogue II was devoid of biological activity and was slowly degraded in the parotid system and by several proteases. Analogue II was a full agonist of the SP-P receptor with a potency of 22 and 15% of the parent compound I, in the guinea-pig ileum and parotid slice system respectively. Pretreatment of the guinea-pig ileum with atropine (0.3 microM) had no effect on the potency of analogue III. On the other hand, when tested on rat vas deferens (an SP-E system), analogue III was about 20-fold more potent than the parent compound I.(ABSTRACT TRUNCATED AT 250 WORDS)

The nature of epilepsy in the general population. I. Characteristics of patients receiving medication for epilepsy.

The study is a community-based study carried out in the UK to determine the characteristics of patients receiving treatment for epilepsy, with particular reference to the duration, nature and severity of epilepsy. 119 participating general practitioners distributed questionnaires to 2528 patients taking medication for epilepsy. Information requested included the age and sex distribution of the patients, seizure type, duration of epilepsy and frequency of seizures, employment status of the patients, and state benefits received. 1628 patients replied. The prevalence of people receiving treatment for epilepsy was estimated at 4.5/1000. Fourteen per cent were under the age of 20 years and 23% were aged 60 or more. Seventy per cent had had epilepsy for at least 5 years, while 8% had been diagnosed in the previous year. Fifty-three per cent had had one or more seizures in the year prior to the survey, and 20% had seizures at least monthly on average. Most patients had seizures of partial origin. The rate of unemployment and receipt of social security benefits was higher than in the general population. The study indicates that the majority of patients receiving treatment for epilepsy in the community have long-standing epilepsy, often intractable to medical treatment, and associated with considerable social handicap. Health care planning should take this into account.

The nature of epilepsy in the general population. II. Medical care.

The medical care received by an unselected population of patients with epilepsy identified from the lists of 119 general practitioners in the UK was evaluated and compared with established standards. The study was carried out by questionnaire distributed to the patients and their general practitioners. Information was collected about hospital referral patterns, the doctor responsible for follow-up, investigations performed, attendances at Accident and Emergency (A&E) departments, hospital admissions, medication, and the information supplied to patients. Eighty-one per cent of patients had been referred to a hospital outpatient clinic, and 28% were under continuing hospital follow-up. Only 6% had been seen in a specialist epilepsy clinic. The majority had had an electroencephalogram (EEG), but less than half a CT scan. Forty-three per cent had attended an A&E department on account of epilepsy, and 47% had required hospital admission. Sixty-five per cent of patients were on monotherapy, mostly phenytoin, carbamazepine or sodium valproate: a significant proportion also took phenobarbitone. Except for the issues of free prescriptions and driving, patients could remember being given little information about epilepsy, and this was the most common source of dissatisfaction. The study suggests many accepted recommendations about the care of people with epilepsy are not followed, with hospital referral patterns, a shortage of specialists epilepsy clinics, and lack of patient information being areas of concern.

The efficacy and long-term tolerability of lamotrigine in the treatment of severe epilepsy.

We report the effects of the addition of lamotrigine, a novel antiepileptic drug, to the therapy of 125 patients with severe refractory epilepsy. Forty-five patients (36%) reported adverse experiences and in 19 (15%), the drug was withdrawn. The commonest adverse experiences were diplopia, headache, ataxia, drowsiness, skin rash and deterioration in seizure control. Two patients were withdrawn for other reasons. The remaining 104 patients were followed for a mean of 11 months (range 3-27): 26 (25%) of these showed a marked improvement in seizure frequency (a 50% or more reduction when compared with the pre-trial period), but no patient was rendered seizure-free. Tolerance to the effects of the drug was not seen.

The cost of epilepsy in the United Kingdom: an estimation based on the results of two population-based studies.

Epilepsy has important socio-economic costs to a population. It is important to assess these costs so that health care priorities can be set. We assessed the burden of illness of epilepsy at the community level, and from this we were able to estimate costs for an individual and the cost to the United Kingdom (UK) as a whole. Cost analysis was based on two different populations of patients with epilepsy, a prevalent and an incident population. Patients with established epilepsy (n = 1628), who were identified from general practices throughout the UK as part of the National Epilepsy Survey (NES), and patients with newly diagnosed epilepsy (n = 602), from the National General Practice Study of Epilepsy (NGPSE), which is a prospective longitudinal cohort study of epilepsy. Indirect and direct costs were assessed in the NES, and direct costs in the NGPSE. A longitudinal cost profile of epilepsy was calculated, with an average initial direct costs of 611 pounds (US$917) per patient per annum which decreased after eight years of follow up to 169 pounds (US$254) per patient per annum. The cost to the UK of newly diagnosed epilepsy in the first year of diagnosis was 18 million pounds (US$27 million). The total annual cost of established epilepsy to the UK was estimated at 1930 million pounds (US$2895 million), over 69% of which was due to indirect costs (unemployment and excess mortality). The cost of active epilepsy per patient was approximately 4167 pounds (US$6251), and of inactive epilepsy 1630 pounds (US$2445) per patient per annum. Methodological issues in cost studies of epilepsy are reviewed.

All that shakes is not epilepsy.

Experience from the clinic suggests that many people equate the term 'epilepsy' with the occurrence of convulsions, with the corollary that attacks involving shaking are likely to be due to epilepsy. However, just as many seizure types do not involve shaking, the differential diagnosis of intermittent shaking is wide and includes vasovagal syncope, cardiac disorders, concussive convulsions, psychogenic non-epileptic seizures, 'shaking transient ischaemic attacks', parasomnias, breath-holding attacks in children, hypoglycaemia and movement disorders.

Evolutionary trade-offs, Pareto optimality, and the geometry of phenotype space.

Biological systems that perform multiple tasks face a fundamental trade-off: A given phenotype cannot be optimal at all tasks. Here we ask how trade-offs affect the range of phenotypes found in nature. Using the Pareto front concept from economics and engineering, we find that best-trade-off phenotypes are weighted averages of archetypes--phenotypes specialized for single tasks. For two tasks, phenotypes fall on the line connecting the two archetypes, which could explain linear trait correlations, allometric relationships, as well as bacterial gene-expression patterns. For three tasks, phenotypes fall within a triangle in phenotype space, whose vertices are the archetypes, as evident in morphological studies, including on Darwin's finches. Tasks can be inferred from measured phenotypes based on the behavior of organisms nearest the archetypes.