Representational Difference Analysis (RDA) reveals differential expression of conserved as well as novel genes during caste-specific development of the honey bee (Apis mellifera L.) ovary

In highly eusocial insects, such as the honey bee, Apis mellifera, the reproductive bias has become embedded in morphological caste differences. These are most expressively denoted in ovary size, with adult queens having large ovaries consisting of 150-200 ovarioles each, while workers typically have only 1-20 ovarioles per ovary. This morphological differentiation is a result of hormonal signals triggered by the diet change in the third larval instar, which eventually generate caste-specific gene expression patterns. To reveal these we produced differential gene expression libraries by Representational Difference Analysis (RDA) for queen and worker ovaries in a developmental stage when cell death is a prominent feature in the ovarioles of workers, whereas all ovarioles are maintained and extend in length in queens. In the queen library, 48% of the gene set represented homologs of known Drosophila genes, whereas in the worker ovary, the largest set (59%) were ESTs evidencing novel genes, not even computationally predicted in the honey bee genome. Differential expression was confirmed by quantitative RT-PCR for a selected gene set, denoting major differences for two queen and two worker library genes. These included two unpredicted genes located in chromosome 11 (Group11.35 and Group11.31, respectively) possibly representing long non-coding RNAs. Being candidates as modulators of ovary development, their expression and functional analysis should be a focal point for future studies. (C) 2011 Elsevier Ltd. All rights reserved.

Sudden unexpected death in an adolescent with epilepsy: All roads lead to the heart?

The incidence of sudden unexpected death in epilepsy (SUDEP) has been estimated from 0.5-1.4/1,000 person-years in people with treated epilepsy, and 9/1,000 person-years in candidates for epilepsy surgery. Potential risk factors for SUDEP include: age, early onset of epilepsy, duration of epilepsy, uncontrolled seizures, seizure type and winter temperatures. The arrythmogenic side-effect of antiepileptic drugs and seizures may increase the risk of SUDEP. In this report, we describe a patient with prolonged post-ictal tachycardia in EEG video recordings with a typical case of SUDEP: a 16-year-old boy with medically intractable complex partial seizures. Magnetic resonance imaging revealed left mesial temporal sclerosis. During non-invasive video-EEG monitoring, the patient presented a post-ictal heart rate increased for five hours. Two months after video-EEG, he died from SUDEP during a tonic-clonic secondary generalized seizure. The possibility of cardiac involvement in the pathogenesis of SUDEP has been suggested by many studies. Evaluation of this patient with EEG-video monitoring, including measurement of heart rate, contributed to an identification of ictal tachycardia that may have played a role in the SUDEP. Premature mortality seems to be increased in patients with epilepsy, and cardiac abnormalities may be a possible cause of SUDEP. (Cardiol J 2011; 18, 2: 194-196)

Pediatric epilepsy surgery and sudden unexpected death epilepsy: the contribution of a Brazilian epilepsy surgery program

Individuals with epilepsy are at higher risk of death than those from the general population, and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Epilepsies in the pediatric group are more frequently associated with known potentially risk factors for SUDEP, and a treatment resulting in an improved seizure control may also decrease mortality. The aim of this study is to identify the incidence of SUDEP in a group of operated-on children and adolescents. We analyzed 267 patients up to 18 years old, with medically intractable epilepsy submitted to surgery. We considered the age at surgery, the seizure type, the pathological findings, and the seizure outcome. Data were prospectively collected, according to the protocols of our institution`s ethics committee. The percentage of boys was 58.05. A good outcome was achieved in 72.6% of the cases and a bad outcome in 27.4%. Nine patients died during follow-up, six from clinical complications, and one from SUDEP. All patients who died during the long-term follow-up had persisted with refractory postoperative seizures. The patient who died from SUDEP died during a generalized tonic-clonic seizure. Of the patients, 72.6% had excellent postoperative outcome, and one patient died of SUDEP. All patients who died had had disabling seizures` persistence. The surgical treatment of epilepsy in children and adolescents is an efficient therapy for the medically intractable symptomatic epilepsies and also for the reduction of mortality and SUDEP risks.

Subclinical hyperthyroidism and sudden unexpected death in epilepsy

Epilepsy is the most common serious neurological condition and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Information concerning risk factors for SUDEP is conflicting, but high seizure frequency is a potential risk factor. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmias during and between seizures or transmission of epileptic activity to the heart via the autonomic nervous system potentially play a role. In parallel, several studies have shown a link between hormones and epilepsy. However, exact knowledge regarding the association of thyroid hormones and epilepsy is lacking. As subclinical hyperthyroidism has been linked with increased risk of cardiovascular disease, we propose in this paper that SUDEP, at least in some cases, could be related with subclinical thyroid dysfunction. (C) 2009 Elsevier Ltd. All rights reserved.

Benefits of sunlight: Vitamin D deficiency might increase the risk of sudden unexpected death in epilepsy

Epilepsy is the most common serious neurological condition and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. information concerning risk factors for SUDEP is conflicting, but high seizure frequency is a potential risk factor. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmias during and between seizures or transmission of epileptic activity to the heart via the autonomic nervous system potentially play a role. In parallel, studies have shown a link between vitamin D dysfunction and epilepsy. Moreover, several evidences in the literature suggest an association between low vitamin D and seizures, indicating the possibility of anticonvulsant properties of this hormone. Quite interesting, a growing body of data suggests that low vitamin D levels may adversely affect cardiovascular health, directly associated with death from heart failure and sudden cardiac death. In view of the above findings, our research group focused in this review article that SUDEP, at least in some cases, could be related with low vitamin D levels. (C) 2009 Elsevier Ltd. All rights reserved.

Does the lunar phase have an effect on sudden unexpected death in epilepsy?

The incidence of sudden unexpected death in epilepsy (SUDEP) in Our epilepsy unit over an 8-year period was analyzed to determine a possible association between phase of the moon and SUDEP. Analysis revealed that the number of SUDEPs was highest in full moon (70%), followed by waxing moon (20%) and new moon (10%). No SUDEPs Occurred during the waning cycle. These preliminary findings suggest that the full moon appears to correlate with SUDEP. (C) 2008 Elsevier Inc. All rights reserved.