Question | Answer |
What are the needed coenzymes of Branched-chain alpha-ketoacid dehydrogenase? | Thiamine, Lipoate, Coenzymes A, FAD, and, NAD |
What enzyme is deficient in Maple Syrup disease? | Branched-chain a-ketoacid dehydrogenase |
Deficient Branched-chain alpha-ketoacid dehydrogenase. Dx? | Maple Syrup Urine disease |
What is the common treatment for Maple Syrup Urine disease? | High-dose Thiamine |
Which condition is associated with lifelong dietary restriction of Leucine, Isoleucine, and Valine? | Maple Syrup Urine disease |
Which amino acids should be avoided at all costs in patients with Maple Syrup disease? | Leucine, Isoleucine, and Valine |
What is Medullary Thyroid cancer? | Neuroendocrine tumor that arises for Parafollicular Calcitonin-secreting C cells |
What malignancy is derived from Parafollicular Calcitonin-secreting cells? | Medullary Thyroid cancer |
What are the histological features of Medullary Thyroid cancer? | Nests or sheets of Polygonal or Spindle-shaped cells with extracellular amyloid deposits derived from Calcitonin |
Histological findings include:
- Spindle-shaped cells
- Extracellular amyloid deposits derived from Calcitonin | Medullary Thyroid cancer |
What is the common treatment for 21-(OH) deficiency? | Low doses of exogenous corticosteroids |
What is the purpose of administering lose dose of exogenous corticosteroids in patients with 21-(OH) deficiency? | Suppress excess ACTH secretion, which reduces production of androgens by the adrenal cortex |
What is the most common Congenital Adrenal Hyperplasia? | 21-(OH) deficiency |
What are common symptoms seen with hypoglycemia? | Tremor, diaphoresis, and confusion |
What type of insulin-toxicity is suspected in a person with hypoglycemia, elevated insulin and low C-peptide levels? | Exogenous Insulin injection |
Hypoglycemia + Elevated Insulin + Elevated C-peptide. | Suggest an insulin secretagogue or insulin secreting tumor |
An insulin secreting-tumor will develop high levels of insulin, hypoglycemia, and high or low levels of C peptide? | High levels of C peptide |
What is the fetal risk of Gestational Diabetes? | Increased transplacental glucose delivery to infant, fetal hyperglycemia, and subsequently Pancreatic B-cell hyperplasia |
What are the fetal physical features of Hyperinsulinemia? | Fetal macrosomia and hypoglycemia after delivery |
What condition is often associated with Fetal Pancreatic B cell islet hyperplasia? | Gestational diabetes |
What is the response of sodium, potassium, and hydrogen ions in primary hyperaldosteronism? | Increased Na+ reabsorption ---> increased urinary secretion of K+ and H+ |
What condition is associated with secondary hypertension, hypokalemia, and metabolic alkalosis? | Primary hyperaldosteronism |
What phenomenon or process maintains serum sodium concentration normal in Primary Hyperaldosteronism? | Aldosterone escape |
What is the relation between Aldosterone escape and sodium? | The Aldosterone escape allow for the maintained of normal serum levels of sodium, despite the increased reabsorption in the collecting tubules |
How is Exogenous Hyperthyroidism characterized? | Elevated free T4, suppressed TSH, and low/undetectable thyroglobulin |
What is the result of the chronic lack of TSH stimulation due to medication or otherwise? | Thyroid follicles become atrophic |
What can be suspected to result in thyroid follicles becoming atrophic? | Lack of TSH stimulation |
What is the result of hypercalcemia in smooth muscle contraction? | Inhibits nerve depolarization, leading to impaired smooth muscle contraction and reduced colonic motility |
What is often the cause of constipation in women with elevated serum calcium, Hx of nephrolithiasis, and abdominal pain? | Hypercalcemia reduces colonic motility by imparirijn nerve depolarization, and thus, halting smooth muscle contraction |
What are the calcium and phosphorus levels associated with Primary Hyperparathyroidism? | Hypercalcemia and hypophosphatemia |
What are the most common Thioamides? | PTU and Methimazole |
Which enzyme is inhibited by Thioamides ? | Thyroid peroxidase |
Thyroid peroxidase is inhibited by the use of which two common hyperthyroid medications? | PTU and Methimazole |
What is Thyroid Peroxidase responsible for? | 1. Iodine organification and,
2. Coupling of iodotyrosine |
Does PTU or Methimazole decrease peripheral conversion of T4 --> T3? | PTU |
What is a common GnRH agonist? | Leuprolide |
What is the effect and mode of action of long-term use of GnRH agonists? | Suppresses pituitary LH release and leads to the reduced production of testosterone |
What are the effects of lower levels of circulating testosterone? | Accelerated bone loss and increased risk of osteoporosis |
In which life-periods are women subjected to increased Estrogen activity? | 1. Pregnancy
2. Post-menopausal women on Estrogen replacement therapy |
Increased levels of estrogen activity, has which Thyroid gland effect? | Increase the level of Thyroid-binding globulin |
What is the result of increased levels of Thyroid-binding globulin? | Increase in total TH levels, but feedback control maintains normal levels of free (biologically active) thyroid hormone |
What are two common examples of Sodium-Glucose Cotransporter 2 inhibitors? | Canagliflozin and Dapagliflozin |
MOA of Sodium-Glucose Cotransporter 2 inhibitors? | Decreased renal reabsorption of glucose and sodium, leading to lower blood glucose levels |
How does the use of Sodium-Glucose Cotransporter-2 inhibitors help reduce blood pressure? | Decreased reabsorption of Na+ and glucose in the collecting tubules |
What is an possible adverse effect of Sodium-glucose cotransporters-2 inhibitors? | Excess urinary glucose increases risk of UTIs |
________________ are used to decrease TH production. | Thioamides |
Why is Methimazole often preferred by patients over PTU to treat hyperthyroidism? | Methimazole is less hepatotoxic than PTU |
Which anti-hyperthyroid medication is used during the 1st trimester of pregnancy? | PTU |
Why is PTU used during the first trimester of pregnancy to treat maternal hyperthyroidism? | Less potential teratogenic effects compared to Methimazole |
What is the fist source of ATP during the beginning of physical exercise? | Phosphocreatine shuttle |
What is a key feature or characteristic of the Phosphocreatine shuttle? | It is the first source of ATP generation during physical exercise and it quickly is depleted |
What are the sequential forms or sources of ATP in physical exercise? | 1st -- Phosphocreatine shuttle
2nd -- Anaerobic glycolysis
3rd -- Oxidative phosphorylation |
How does hyperthyroidism cause bone problems? | It leads to increased bone turnover with net bone loss, potentially leading to osteoporosis |
T3. Stimulates osteoclast or osteoblast activity? | Osteoclast |
What are the effects on bone of T3 activity? | 1. Stimulation of osteoclast differentiation
2. Increase bone resorption
3. Release of Calcium |
What is secreted by the cleavage of Proinsulin? | Insulin and C-peptide in equimolar amounts |
Where is proinsulin stored prior to been released in insulin and C-peptide? | Secretory granules |
What are the Chromaffin cells? | Modified neuroendocrine cells derived from the neural crests |
From which embryonic tissue are Chromaffin cells are derived from? | Neural crests |
What neurotransmitter stimulates the Chromaffin cells in the Adrenal medulla? | Acetylcholine |
Where are the catecholamines secreted into by the adrenal medulla? | Directly into bloodstream to amplify sympathetic neurons system activation |
What is directly stimulated by PTH? | Stimulates Osteoblasts, leading to increase bone formation |
On what cells is RANK-L expressed in? | Osteoblasts |
What does the expression of RANK-L on osteoblast cause? | Induce increases bone resorption via a Paracrine effect on osteoclasts |
Which are directly affected by PTH, osteoblasts or osteoclasts? | Osteoblasts |
Which are INDIRECTLY affected by PTH, osteoblasts or osteoclasts? | Osteoclasts |
What are the factors in hyperparathyroidism that lead to net bone loss? | 1. Increased RANK-L expression on osteoblasts
2. Decreased expression of osteoprotegerin |
What type of urinary incontinence is due to diabetic autonomic neuropathy? | Overflow incontinence |
How does Diabetic autonomic neuropathy causes overflow incontinence? | Inability to sense full bladder and incomplete voiding leading to obstruction |
What are the main causes of Overflow incontinence? | 1. Impaired detrusor contractility or,
2. Bladder Outlet Obstruction |
Which condition is consistent with thick, viscous, secretion o in ducts throughout the body? | Cystic fibrosis |
What causes Cystic Fibrosis-related Diabetes? | After the progressive destruction of Pancreatic islet cells leads to decreased insulin production |
What is the pathogenesis of Diabetes mellitus type 2? | Insulin resistance and relative insulin deficiency |
What is an important factor contributing to DM2 pathogenesis? | Chronically elevated Free Fatty acid levels |
How do elevated Free Fatty acid levels contribute to insulin resistance? | Impairing insulin-dependent glucose uptake and increasing hepatic gluconeogenesis |
How does glucagon increases serum glucose levels? | By increasing hepatic glycogenolysis and gluconeogenesis |
What is the effect of glucagon on pancreatic insulin release? | Increases secretion of insulin by pancreas |
What is an important difference in the MOA of glucagon and epinephrine? | Glucagon has an insignificant effect on glucose homeostasis i the skeletal muscle, adipose tissue, and renal cortex |
Which has a significant effect on glucose homeostasis, epinephrine or glucagon? | Epinephrine |
Which substance is known to have an INSIGNIFICANT effect on glucose homeostasis in the skeletal muscle, renal cortex, and adipose tissue? | Glucagon |
What is the MOA of Metformin? | 1. Inhibits hepatic gluconeogenesis and,
2. Increases peripheral glucose utilization |
What is a rare but severe adverse effect of Metformin? | Lactic acidosis |
Which type of patients have increase risk of developing Lactic acidosis due to Metformin use? | Renal insufficiency patients |
How does chronic use of glucocorticoids leads to osteoporosis? | They inhibit replication and differentiation of osteoblast precursor cells, increase osteoclast activity, and promote renal and intestinal calcium wasting |
Which drug class is known to promote osteoporosis by inhibiting the differentiation and replication of osteoblastic precursor cells? | Glucocorticoids |
What are the 3 main effects of glucocorticoids that lead to Osteoporosis? | 1. Inhibit replication and differentiation of osteoblast precursor cells
2. Increase osteoclast activity
3. Promote Intestinal and Renal calcium (Ca2+) watsting |
SERM, that has estrogen agonist effect on bone and decreases bone resorption | Raloxifene |
What are some common drugs that increase risk of venous thrombotic events? | Drugs with estrogen agonist activity, such as Raloxifene, OCP, and Hormone Replacement therapy |
How do Thiazolidinediones lower blood glucose? | By decreasing insulin resistance |
What receptor is activated by Thiazolidinediones? | PPAR-gamma |
What is the result of activation of the PPAR-gamma receptor by Thiazolidinediones? | Alters the transcription of genes involved in glucose and lipid metabolism |
Which receptor, at it gets activated by drugs, causes alteration in the transcription of genes involved in glucose and lipid metabolism? | PPAR-gamma |
What are clinical results of glucocorticoid's catabolic features? | Muscle weakness, skin thinning, impaired wound healing, osteoporosis, and immunosuppression |
What is the effect on the liver by glucocorticoids? | Increased hepatic synthesis of gluconeogenic and glycogenic proteins to increase glucose availability |
How does the liver in association to glucocorticoids help increasing glucose availability? | Increasing hepatic synthesis of gluconeogenic and glycogenic proteins |
Ultimately, glucocorticoid use, cause a patient to become hyper- or hypoglycemic? | Hyperglycemic |
What is an common GnRH antagonist used in treatment of Prostate cancer? | Leuprolide |
What is the initial result of the use of continuous Leuprolide? | Stimulates pituitary LH secretion, which lead to a rise in androgen levels |
Initially, the use of Leuprolide, will increase or decrease the levels of Androgens? | Increase |
What is the late result of Leuprolide use in treating Prostate cancer? | GnRH receptor is downregulated, which dramatically drops LH release and lead to a long term decrease in androgen production |
What causes TSH resistance? | Mutation in TSH receptor gene |
How is TSH resistance clinically presented? | Congenital hypothyroidism characterized by increased TSH and low thyroxine |
How is the structure of TSH resistance hypothyroidism? | Thyroid gland in normal in size and location |
What are some Estrogen precursors? | Androstenediones, DHEA, and DHEA sulfate |
What occurs to estrogen precursors in peripheral tissues? | Aromatized into estrogens |
What is an embarrassing side effect in males due to hypogonadism? | Decreased testosterone leads to elevation of the estrogen:testosterone level, leading to gynecomastia |
What is the role of Ghrelin? | Stimulates appetite and promotes weight gain |
A high activity of Ghrelin, means a person going to lose or gain weight? | Gain weight |
What hormone is responsible for stimulating appetite and promote weight gain? | Ghrelin |
What are some hormones that work n the CNS and decrease or suppress appetite? | Leptin and Insulin |
A caloric restriction would lead to an increased level of ghrelin or decreased level of ghrelin? | Increased Ghrelin |
A person hungry has what levels of Leptin, insulin, and ghrelin? | Increased Ghrelin, and decreased leptin and insulin levels |