Parental SCN1A mutation mosaicism in familial Dravet syndrome

Different SCN1A mutations are known to cause a variety of phenotypes, such as generalized epilepsy with febrile seizures plus (GEFS+), Dravet syndrome and familial hemiplegic migraine (FHM). In Dravet syndrome, most mutations are de novo and familial cases are rare. In this study, Dravet syndrome is observed in two maternal half sisters. They have healthy fathers and their common mother has never experienced seizures, but has a lifelong history of migraine. Direct sequencing of DNA extracted from blood revealed a heterozygous SCN1A nonsense mutation c.3985C>T in the sisters, but not in the mother. The mutation induces a premature stop codon and probably leads to a non-functional protein. Further examination of the mother's DNA showed that she has a mosaicism of the mutation. This report of parental SCN1A nonsense mutation mosaicism in familial Dravet syndrome suggests that mosaicism might be more common than previously suspected and emphasizes the importance of taking mosaicism into account in genetic counselling of Dravet syndrome and SCN1A mutations. Furthermore, whether the migraine of the mother could be influenced by her SCN1A mutation mosaicism is not known, but increased awareness of migraine in future studies of SCN1A related epilepsies could clarify this intriguing link between migraine and epilepsy.     

Hepatitis B e antigen negative chronic hepatitis in Indian patients : A reality

Background: Hepatitis B e antigen negative chronic hepatitis (e⁻ CHB) with detectable levels of hepatitis B virus DNA (HBV DNA) in serum has been reported in cases from Asia. This study was undertaken to find out prevalence e⁻CHB and to correlate its presence with the clinical status and severity of the illness in cases of chronic liver disease in India.     

A Laboratory Investigation into Oviposition Responses of Aedes aegypti to Some Common Household Substances and Water from Conspecific Larvae

Background

The surveillance of Dengue vector – Aedes aegypti, is routinely done by using ovitraps (a dark container filled with water and a wooden paddle/towel cloth provided as a oviposition substrate), which indicates the extent of Aedes activity in an area.

Method

The study evaluated the oviposition responses of laboratory bred gravid Aedes aegypti to commonly available household substances by use of ovitrap method.

Results

Oviposition avoidance or deterrence was exhibited by gravid Aedes to ovitraps baited with salt, fenugreek, vinegar, lime juice, hibiscus leaves, radish and curry leaves, whereas positive oviposition response was noticed to waters from conspecific (of the same species) larvae and cumin seeds baited ovitraps.

Conclusion

The study findings may be utilized by researchers for further chemical analysis of the active ingredients of the substances found promising with a view to explore the possibility of their use by community and individuals for Aedes surveillance and control.Key Words: Aedes, Dengue, Oviposition deterrence/attraction     

Simulation and its role in medical education

Medical education is increasingly laying emphasis on a curriculum based on cognitive, psychomotor, and affective domains of learning which were originally proposed nearly 50 years ago. These reforms are framed around best standards of care, error management and patient safety, patient autonomy, and resource allocation. There is a worldwide shift in the method of medical education towards experiential (‘hands-on’) medical learning; however, applying this concept to real patients is less acceptable to society and is subject to legal and ethical issues.     

Factor V activity of platelets: evidence for an activated factor V molecule and for a platelet activator

This study was prompted by the observation that fresh platelet suspensions--prepared by gel filtration or albumin density gradient centrifugation--possessed only minimal factor V activity, whereas frozen-and-thawed platelet suspensions possessed striking factor V activity. Results of experiments with fresh suspensions suggested that unaltered platelets did not bind plasma factor V. The factor V activity of frozen-and-thawed platelet suspensions was markedly diminished after exposure to a factor V antibody, was not activated by thrombin, and was not associated with an increase in factor V antigen over that found in fresh platelet suspensions. Consequently, disruption by freezing and thawing must have resulted in the appearance of small amounts of an activated factor V molecule in platelet suspensions. Disrupted platelets were shown to activate native factor V, but an interaction between a platelet activator and traces of native factor V in fresh suspensions could not be demonstrated to account for the full activity of frozen-and-thawed suspensions. Apparently, therefore, platelets also contained an activated factor V molecule. Adding collagen, but not adenosine 5'-diphosphate to fresh platelet suspensions increased their factor V activity. Release of an activated platelet factor V molecule after exposure to collagen could represent a physiologically significant early step in hemostasis.