A clinical study of type 1 neurofibromatosis in

The article titled A clinical study of type 1 neurofibromatosis in north west England (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1734324/pdf/v036p00197.pdf) includes a study in NW England about Neurofibromatosis type 1 (NF1).  They found that in this particular region about 1 in 3000 to 1 in 4000 people have inherited this disorder which can be found as a mutation on chromosome 17.  The authors studied characteristics of NF1 and found Café au lait spots, Axillary freckling, Groin freckling, cutaneous NF as well as subcutaneous NF to be common symptoms associated with NF1.  The most common of outcomes due to these symptoms included optic nerve gliomas and Malignant nerve sheath tumors (MNST). The authors used a “time until an event” system from date of diagnosis to date of birth to determine percent’s of individuals and severity of symptoms and age comparison.  Out of the 523 persons affected by NF1, 327 of which were found to have a first degree relative showing symptoms of NF1 as well.  There was no evidence to show preference over male to females born to mothers known to have NF1.  Table 2 (found in article) demonstrates that younger persons tend to have higher numbers of expressed symptoms in comparison with persons of age.  This could be due to a higher death rate in cases with more severe symptoms or a greater number of symptoms expressed.  Of the reported tumors Plexiform tumors followed by Malignant nerve sheath tumors were found to have to highest percent rate of risk.  The necessary information was not available in regards to previous-existing plexiform neurofibromas. 

I am more interested in MNST and if anyone knows of a better study or any idea as to where to look, please share.  I am looking forward to learning more about MNST and will probably be writing another blog solely about them.  Thanks for your help!

Alcohol and Nuerotransmitter Interactions

I found an interesting article titled Alcohol and Neurotransmitter Interactions (http://pubs.niaaa.nih.gov/publications/arh21-2/144.pdf). The article states that alcohol disrupts the sensitive balance between inhibitory and excitatory neurotransmitters (NT) which can be thought of as a sort of scale such as a titer totter. Short term use of alcohol or binge drinking causes inhibitory neurotransmitters to become more heavily weighted on this scale which the article states decreases responsiveness of other neurons to further stimuli. Long term use of alcohol has just the opposite effect and the brain tries to equilibrate this unbalanced scale and thus increases the amount of excitatory neurotransmitters. Alcohol affectively increases receptors of glycine which acts as an inhibitory NT in the spinal cord as well as the brain stems causing the behavioral changes associated with alcohol consumption. The main inhibitory NT is called Gamma-aminobutyre (GABA) which is also responsible for behavioral changes. Increased amounts of GABA (in short term use or binge drinking) due to the effects of alcohol on Purkinje cells also affects the activation of neuroepinefrin which controls the NTs. Neuromodulators such as adenosine are increased which leads to the sedative effect of alcohol. Chemicals such as caffeine and theophylline found in coffee and energy drinks have the opposite affect and inhibits adenosine which is why it is very dangerous to mix alcohol with beverages containing caffeine. The main excitatory NTs are known as N-methel-D-aspartate (NMDA) and when these excitatory receptors show activity, increase changes in calcium levels of the nerve cells. GABA and NMDA are thought to work together and ultimately change the voltage-sensitive calcium channels, which in turn, are responsible for the electrical currents created in the neurons. In addition, short term use of alcohol increases GABA and inhibits the calcium flow which is vary dangerous because in large quantities can cause death through sedation of breathing and heart rate. In contrast, long term use decreases GABA which decreases the sensitivity to NTs.

I am still a little confused and would greatly appreciate any feedback to hopefully clarify this study. It was also hard to state the authors findings in a better way, simply said, they said it best!