Congenital Defects, Genetic Therapy, and Age-Related Diseases in Medicine

Genetic Therapy

Introduction of genes into multicellular plants and animals using harmless viruses.

Two possible approaches of genetic therapy

1. Transferring genes to replace harmful ones, 2. Selectively inhibiting defective genes.

Etiology of Down Syndrome

95% of cases result from error in cell division during meiosis.

Triple Screen

A maternal blood test measuring alpha-fetoprotein, human chronic gonadotropin, and estroil.

Amenorrhea

The absence of menstruation; categorized as primary or secondary.

Bulimia Nervosa

An eating disorder characterized by binge eating followed by purging.

Dysmenorrhea

Painful menstruation.

Epstein-Barr Virus

The causative agent of Infectious Mononucleosis.

Gonadotropins

Hormones that trigger the onset of reproductive changes.

Kyphosis

An abnormal spinal curvature characterized by increased convexity of the thoracic spine.

Leukocytosis

An increase in the number of white blood cells in the blood, often indicating infection.

Lordosis

An abnormal spinal curvature characterized by increased concavity of the lumbar spine.

Osteomyelitis

An infection of the bone, often resulting from trauma.

Sequestrum

A piece of dead bone tissue formed during the process of osteomyelitis.

Splenomegaly

Abnormal enlargement of the spleen, seen in conditions like Mononucleosis.

Turner's Syndrome

A chromosomal disorder in females where one X chromosome is missing.

Gravidity

Total number of times a person has been pregnant, regardless of the outcome.

Parity

Specifically counts the number of pregnancies who have reached the point of viability.

Embryo

From conception till end of eighth week.

Estimated Date of Delivery (EDD)

EDD = subtract three months from date of LMP + add 7 days.

Biological marker in pregnancy test

The chronic villi that are vascular projections that forms part of the placenta releases human chorionic gonadotropin (hCG).

Folic acid supplements

Helps reduce the risk of neural tube defects, specifically prevents spina bifida and anencephaly.

Primigravida

A person who is experiencing their first pregnancy.

Multipara

A person who had two or more pregnancies that reached viability.

Primary components of placenta

Chronic villi, decidua basalis with maternal blood circulating intervillous space, supported by umbilical cord, spiral arteries, and chronic plate.

Pregnancy induced hypertension (PIH)

Elevated blood pressure above 140/90 mmHg, develops after 20 weeks of gestation.

Preeclampsia

High blood pressure, proteinuria, weight gain, and generalized edema.

Eclampsia

More severe condition that includes all of the above plus onset seizures.

Placenta Previa

When the placenta is implanted very low in the uterus or completely covers the internal os, leading to painless bleeding.

Abruptio Placenta

Premature separation of placenta from uterine wall resulting in painful bleeding.

DIC Mechanism

Serious complication of preeclampsia or placental abruption characterized by extra activity of clotting mechanism.

Post-childbirth leg clots

Thrombophlebitis (clot in vein becomes inflamed) and phlebothrombosis (clot in deep veins without initial inflammation).

Thromboembolism Path

A blood clot that has detached and moves through the circulatory path until it gets caught in smaller vessels.

Rh Incompatibility (first pregnancy)

First exposure to PH-positive fetal antigens leads to IgM antibodies that do not cross the placenta.

Rh Incompatibility (second pregnancy)

Mother rapidly produces IgG antibodies that cross the placenta, destroying fetal red blood cells.

Types of immobility

Single body part, paraplegia, hemiplegia, entire body.

Muscle inactivity effects

Inactive muscle will lose strength, endurance, and mass, leading to atrophy and contractures.

Factors contributing to skin breakdown

Ischemia at prolonged pressure points, poor circulation, edema, improper nutrition, mechanical irritation, extra moisture, and friction.

Prolonged immobility impact on cardiovascular system

Causes orthostatic hypotension and increases risk of thrombosis and embolisms.

Respiratory complications of immobility

Decreased oxygen demands, buildup of secretions, leading to pneumonia or atelectasis.

Three stages of general Adaptation syndrome (GAS)

Alarm stage, resistance stage, exhaustion stage.

Sympathetic nervous system during alarm stage

Releases norepinephrine causing vasoconstriction in skin and viscera, decreasing glomerular filtration rate.

Role of adrenal cortex during resistance stage

Stimulated by ACTH to release cortisol and aldosterone, increasing blood volume and blood pressure.

Theoretical factors of aging

Genetic programming, wear and tear, cellular damage, increased collagen cross-linkages.

Telomeres

Repetitive sequence at the ends of chromosomes that shortens with age, linked with decreased life spans.

Role of DNA in aging

DNA repair mechanisms decline with age, leading to accumulated mutations.

DNA Repair Mechanism

Declines as organisms age, leading to accumulated mutations.

Senescence

State where cells stop dividing but remain metabolically active.

Cardiac Muscle Changes

Fatty tissue and collagen accumulate, decreasing muscle strength and cardiac output.

Menopause

Occurs around age 50 when ovaries fail to respond to FSH and LH, decreasing estrogen and progesterone.

Benign Prostatic Hyperplasia (BPH)

Nodular hyperplasia of the prostate gland related to testosterone decline.

Heart Disease and Stroke Statistics

29% of deaths in Canada are due to heart disease and strokes.

Total Arterial Occlusion

Can lead to myocardial infarction or cerebrovascular accident (stroke) due to blood flow interruption.

Aneurysm

An occlusion, rupture, or hemorrhage of a large artery, often resulting from atherosclerosis.

Angina Pectoris

Ischemic heart disease caused by partial occlusion of coronary arteries.

Apoptosis

Programmed cell death triggered by shortened telomeres or significant DNA damage.

Atherosclerosis

Narrowing of large arteries caused by accumulation of cholesterol plaque and thrombus.

Cerebrovascular Accident (CVA)

Also known as a stroke; result of total occlusion of carotid or cerebral arteries.

Collagen Cross-linkage

Age-related increase in binding of collagen fibers, contributing to tissue stiffness.

Embolus

A blood clot or piece of plaque that breaks off and blocks a smaller artery.

Epigenetic Modification

Alterations in DNA methylation or histone modifications influencing aging.

GDF11

A secreted growth differentiation factor that may drive aging when decreased.

Myocardial Infarction (MI)

A heart attack resulting from total occlusion of a coronary artery.

Reactive Oxygen Species (ROS)

Chemically reactive molecules that can cause cellular damage, primarily produced by mitochondria.

Stenosis

Narrowing of an opening, such as a heart valve or artery, limiting blood flow.

Osteoporosis

Loss of calcium and bone mass, increasing fracture risk, especially in postmenopausal women.

Osteoarthritis

Non-inflammatory condition characterized by loss of cartilage and formation of bone spurs.

Analgesics

Medications used to provide pain relief, often for osteoarthritis.

Dysphagia

Difficulty or discomfort in swallowing, often due to neurological changes.

Fosamax

A drug used in osteoporosis therapy that inhibits bone resorption.

Glaucoma

Eye condition characterized by increased ocular pressure due to obstruction of aqueous humor flow.

Macular Degeneration

Blindness caused by vascular degeneration in the retina.

Myelin Sheath

Insulating layer around nerves; its loss is associated with aging.

Nocturia

Frequent need to urinate at night.

Osteophyte

Bony outgrowth or spur formed in joints affected by osteoarthritis.

Presbyopia

Farsightedness caused by loss of elasticity and increased lens size.

Three primary causes of congenital defects

1. Genetic factors, 2. Environmental factors, 3. Intrauterine factors.

Chromosomal disorder

Results from errors in meiosis and can cause spontaneous abortion.

Heterozygous

A person having two different versions (alleles) of a gene, one normal and one affected.

Characteristics of multifactorial disorders

Involves multiple genes or results from inherited tendency plus exposure to environmental factors.

X-linked recessive disorders

Disorders most common in males because the allele is carried on the X chromosome.

Teratogenic agent

An environmental factor that produces abnormalities during embryonic or fetal development.

Prenatal testing

Includes ultrasound, maternal serum screening, chorionic villus sampling, and percutaneous umbilical blood sampling.

Nuchal Translucency

A specific measurement taken during ultrasound of the fetus to check for abnormalities.

Organogenesis

The beginning of fetal development when organs and tissues are most affected by teratogens.

TORCH infections

Maternal infections that are possible causes of congenital defects.

Trisomy

A chromosomal disorder of having three copies of a gene on chromosome 21.

Primary goals of gene manipulation

To remove defective genes with the implant of normal genes.

Adolescence

The period of life between ages 10-12 and 18 years, marked by significant changes.

Puberty

The onset of reproductive changes involving organs like ovaries and testes.

Scoliosis

A lateral deviation or curvature of the spine, which can be structural or functional.

Fetus

Beginning of ninth week till birth.

Ectopic pregnancy

A fertilized ovum implants in a location outside of the main uterine cavity.

Possible sites for ectopic pregnancy

Fallopian tubes, ovaries, or the abdominal cavity.

Endometritis Causes

Inflammation of the endometrium often caused by retained products of conception.

Osteoblastic vs. Osteoclastic activity

Decrease in osteoblastic activity while osteoclastic activity continues leads to osteoporosis.

Immobility impact on children's growth

Causes delayed growth and deformities of extremities.

Hormonal Changes in Aging

Hormone production may remain constant, but tissue receptors decrease, affecting hormone response.

Mitosis

Process of cell division that slows down with age, leading to decreased tissue repair.

Thrombus

A blood clot formed within the vascular system that can obstruct blood flow.