Showing posts with label endocrinology. Show all posts
Showing posts with label endocrinology. Show all posts

Saturday, February 18, 2012

Gila Monster and GLP!

Gila monster is the only venomous lizard native to the United States and one of only two known species of venomous lizards in North America


Venom is produced in modified salivary glands in the Gila monster's lower jaw, unlike snakes, whose venom is produced in the upper jaw. 
In 2005,  drug exenatide was approved (marketed as Byetta) for the management of type 2 diabetes. It is a synthetic version of a protein, exendin-4, derived from the Gila monster's saliva.
Exenatide led to healthy sustained glucose levels and progressive weight loss. The effectiveness is due to the fact that exenatide is about 50 percent identical to glucagon-like peptide-1 analog (GLP-1), a hormone released from the human digestive tract that helps to regulate insulin and glucagon. The lizard protein remains effective much longer than the human hormone, helping diabetics keep their blood sugar levels under control. 
Exenatide slows the emptying of the stomach and causes a decrease in appetite, contributing to weight loss.
The saliva of the Gila monster contains many chemicals which can be deadly. One of these has been shown to affect memory. Several companies have been researching the abilities of this chemical to help memory loss due to various diseases such as Alzheimer’s, schizophrenia, and ADHD. Gilatide, derived from exendin-4, has been shown to dramatically heighten memory in a study with mice. Gilatide is likely to be researched further to provide help to Alzheimer’s patients.
Source: Wikipedia

Wednesday, February 8, 2012

Neonatal Diabetes



Disease characteristics. Permanent neonatal diabetes mellitus (PNDM) is characterized by the onset of hyperglycemia within the first six months of life (mean age: 7 weeks; range: birth to 26 weeks) that does not resolve over time. Clinical manifestations at the time of diagnosis include intrauterine growth retardation (IUGR); hyperglycemia, glycosuria, osmotic polyuria, severe dehydration, and failure to thrive.


Approximately 20% of individuals with mutations in KCNJ11 have associated neurologic findings, called the DEND syndrome (developmental delay, epilepsy, and neonatal diabetes mellitus)


a milder form without seizures and with less severe developmental delay is called intermediate DEND syndrome


Pancreatic hypoplasia caused by homozygous PDX1 mutations results in severe insulin deficiency and exocrine pancreatic insufficiency.


Management. Treatment of manifestations: Start rehydration and intravenous insulin 






The five genes currently known to be associated with nonsyndromic PNDM (Autosomal Dominant) are KCNJ11(~30% of PNDM), ABCC8 (~19%), INS (~20%), GCK (~4%), and PDX1 (<1%). Molecular genetic testing is available on a clinical basis for all genes
Some Autosomal Recessive Mutations also exist
Prenatal counselling needs to be done in affected families


Courtesy: http://www.ncbi.nlm.nih.gov/books/NBK1447/


Image courtesy: http://diabetes.diabetesjournals.org/content/57/11/2889.full

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