Lesson 5 Flashcards
What is teratology?
It is the study of abnormal development. Genetic, infectious and chemical factors cause congenital abnormalities in humans, the developmental stage during which the treatment occurred is the critical factor in determining the effects and targets.
Which are some general examples of human developmental toxicants?
- Radiation: a potential source is radiotherapy
- Infections: rubella virus, cytomegalovirus, herpes virus hominis, toxoplasmosis, syphilis
- Maternal metabolic imbalances: alcoholism, cretinism, diabetes, folic acid deficiency, hyperthermia, phenylketonuria, rheumatic disease
- Drugs and chemicals: androgenic chemicals, antibiotics
- Anticancer drugs
- Anticonvulsant
- Anti-thyroid drugs
Which is (probably) the molecular effect of thaliomide?
The hypothesis is an inhibition of angiogenesis and the generation of ROS leading to apoptosis of the cells.
Which is the 1° principle of teratology?
The access of adverse environmental influence to developing tissue depends on the nature on influences.
Developmental toxicants can be accessible to the embryo or fetus in two ways:
o Directly: ionizing radiation, microwaves, ultrasound
o Indirectly: toxicant that cross the placenta
Which is the 2° principle of teratology?
The final manifestations of abnormal development are death, malformation, growth retardation and functional disorder.
The outcome depends on the dose and chemical characteristics of the developmental toxicant and the developmental stage of the conceptus at the time of exposure
Which is the 3° principle of teratology?
Manifestation of deviant development increase in degree as dosage increases from the no-effect level to the totally lethal level.
The relationship between dose and response does not have to be linear: it can sometimes go from a no-effect level to a maximal effect within a doubling of the dose.
Which is the 4° principle of teratology?
Susceptibility to teratogenic agent varies with the developmental stage at the time of exposure.
Organ systems are most susceptible to perturbation by developmental toxicants prior to and during the phase of organ formation and differentiation.
Development, from fertilization to birth, is a progressive process so that ani adverse outcome after exposure to developmental toxicants will be dictated (in part) by the set of developmental processes active at the time of exposure.
Which is the 5° principle of teratology?
Teratogenic agents act through specific mechanisms on developing cells and tissues to initiate abnormal embryogenesis.
Which is the 6° principle of teratology?
Susceptibility to teratogenesis depends on the genotype of the conceptus and the mother in which this interacts with environmental factors.
Gene-gene and gene-environment interactions play a significant role in the etiology of many developmental defects.
Definition of phatogenesis
It’s the altered process by which the initial molecular interactions lead to a structural or functional deficit, it can involve altered pathology at cellular, tissue or organ level.
