Extra Credit Seminar- Biomarker of exposure and relationship to genetics by Steven Myer, Ph.D

Tobacco smoking during pregnancy has many know harmful side effects to the baby. The child will receive less food and oxygen in vitro. There is an increased risk of miscarriage, stillborn, premature birth, SIDS, and decreased IQ. Also second hand smoke can lead to increased ear infections and asthmas. Almost all the chemicals that are discussed in a general Organic Chemistry college level course are found in tobacco smoke. As the child is exposed to the smoke, there is a great increase in asthmatic syndrome and bronchitis. But the most harmful time comes in the 1st 6-9 weeks of the pregnancy, with the common cleft palate development. 

Because of the over 4000 chemicals in tobacco smoke, there must be a way to study the effects without testing for each in particular. Biomarkers are molecular, biochemical, or cellular alterations that are measurable in bio media, ex: human tissues, cells, fluids. Molecular epidemiology studies biomarkers in a group which must have specificity, sensitivity, and practicality. An important aspect of this field is the toxicological paradigm. The paradigm is as follows; exposure to internal dose to Biological effective dose to early biological effect to altered structure/function and finally disease. A good biomarker is early in the paradigm

There are certain criteria for biomarkers. There must be a relationship between biomarkers and the disease. They must appear at a defined stage of the disease process. Finally they involve non invasive collection techniques such as sputum or urine collection. Amniotic fluid serves as an effective biomarker in the 1st trimester. In tobacco smokers, they have an increase level of 1-hydroxypene which is a non-carcinogen. This is one such biomarker that can be tested in vitro. Another important biomarker for studying the effects of smoking on the baby in vitro is hemoglobin. By matching the maternal and cord blood of the baby, levels of both can be compared. Globin acts as a nucleophile while tobacco acts as an electrophile. They stay bound for 128 days which is the live of an erythrocyte. 

Finally, 4-Aminobiphenyl is a very powerful carcinogen and there is a direct correlation between the levels in mom and baby. The babies weight decreases as the levels of this chemical increases. Strangely, while there is no significant difference in the levels in across the African or American census, there are decrease levels in hispanics. 

Dr. Myers presented the information in a clear and effective way. Since he is one of the professors of pharmacology at UofL medical school, his lecture increase my desire to head to my goal of D.O school and can't wait to learn about this types of topics all school year.

                                            (4-Aminobiphenyl)