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Three functions of Prolactin

Breast development; Milk production; Sexual gratification

LH functions

Females: Triggers ovulation, Devt of corpus luteum;
Males: Production of testosterone by Leydig cells

FSH functions

Females: Follicle growth and oogenesis;
Males: Spermatogenesis

ACTH function

Stimulates Adrenal cortex to release the cortical triad: Aldosterone, Cortisol, Androgens

GH (STH) function

Stimulates growth, mitosis, and protein synthesis at bones and muscles

IGF-1 site of origin and function

Made at liver; mediates [and is agonist for] GH effects

Four Oxytocin functions

Cervical dilation, Uterine contractions, Milk let-down, Neurotransmitter

ADH alternate name and function

Vasopressin; Anti-diuresis [H2O reabsorption] and vascular constriction

Pituitary masses epidemiology

Most are benign, but many secrete 1 or more hormones; 10% of all reported intracranial masses; ≤25% pop

Microadenoma vs macroadenoma

≤1cm X ≥1cm

Most common pituitary adenomas; effect and gender distribution. Which MEN do they appear in?

Prolactinomas; hyperprolactinemia; gynecomastia; mostly female. Appear in MEN1 [pituitary, parathyroid, pancreas].

Symptoms of Hyperprolactinemia

Galactorrhea, Breast enlargement & tenderness, Anovulatory amenorrhea, dysmenorrhea, decreased libido, ED

Hyperprolactinemia treatment

Bromocriptine [Parlodel- a DA agonist] or Cabergoline [Dostinex- an ergot derivative used to Tx Parkinson's, associated with gambling compulsion]

Bromcriptine uses; Mechanism; Contraindications

-Dopamine agonist used in the treatment of pituitary tumors, Parkinson's, Hyperprolactinaemia, Neuroleptic Malignant Syndrome, and DM2.
-For Hyperprolactinemia, given as Parlodel;
-Avoid in Breastfeeding, because decreases Prolactin;

Bromcriptine interactions

-Triptans [serotonin receptor agonists in migraine treatment],
-Decongestants [HTN/tachy],
-Antipsychotics [hTN]

Cabergoline use; Trade; Mechanism; Contraindications

-Hyperprolactinemia treatment [Dostinex];
-DA agonist @ anterior pituitary,
-Decreases Prolactin
-Contraindicated in Breastfeeding

Short Stature diagnostic criteria

2 SDs below average for age/gender;
Gold Standard: Insulin tolerance [0.1ug/kg] followed by sampling for GH. If GH <5 [10 in kids] POS for GH deficiency

Short stature treatment. What interactions and side-effects exist?

GH daily injection: Nutropin, Humatrope, Genotropin; Increase [glu], decrease INR in Coumadin pts; Diabetes, HTN, Pancreatitis

Acromegaly diagnosis and treatment. What side effects are there?

GH levels 1 hr after 1 hr-GTT are >1µ/L;
Surgical resection & Octreotide IM (Sandostatin) or Lanreotide IM (Somatuline);
Cardiomegaly/CHF, HTN, Diabetes, RF, HA, visual disturbance from tumor

Thyroxine forms & distribution

T4: 90%, T3: 10% (4X [T4]); 99% is bound to TBG [Thyroid Binding Globulin]. Only free hormone is active.

Element required for thyroxine

Iodine

Cells producing T4 & mechanism

Follicular cells; bind I to Thyroglobulin [TG]

Iodine-capturing enzyme

Thyroid Peroxidase [TPO]

Thyroxine regulating gland & hormone; regulatory mechanism

TSH [Thyrotropin] made at anterior pituitary in response to T4 levels

Second Thyroid hormone and function

Calcitonin, Ca2+ regulator. Opposes PTH-- decreases serum [Ca2+]

Hypothyroid S/s

Fatigue, Wt gain, Depression, Hair loss, Dry skin, Dysmenorrhea, Brady

Hypo-Iodine incidence

9% omnivores, 25% vegetarians, 80% vegans are LOW

Hashimoto's; Gender distribution; Mechanism

Autoimmune hypothyroidism; 10X more female; Thyroid Peroxidase ABs bind & inhibit T4; Insidious onset w/ hyPER-thyroid 1st; Hi Genetics

Hashimoto's Labs

TPO-antibody & TSH elevated; T3 and T4 depressed

Myxedema signs and symptoms

Non-pitting edema with severe hypothyroidism,
Reduced CO, Mental slowing. May result in myxedemic coma precipitated by stroke/MI

Hypothyroidism treatment & allergic issue; alternative

Levothyroxine [Synthroid or Levothroid]; Made with lactose binder OR
Dessicated thyroid (porcine or bovine)

Thyroid replacement monitoring

Monitor TSH, also T3/T4;
NB: T3 replacement suppresses TSH

Grave's disease hallmarks

Autoimmune Hyperthyroidism [Agonist effect]; Nervous, Tachy, Weight loss, Exophthalmia, Hyperhidrosis, Tremor, Insomnia

Grave's drugs names, mechanism; side effects

Methimazole and Propylthiouracil; Inhibit addition of iodine to Thyroglobulin to block T4 synthesis; Leukopenia, Agranulocytosis, Aplastic Anemia; Hepatotoxicity (PTU also alters INR in Coumadin Tx

1st line Grave's treatment

Methimazole (Tapazole), Propylthiouracil (PTU)

2nd line Grave's treatment

Ablation (w/ I-131) or thyroidectomy, followed by thyroid replacement Tx

Acute thyroiditis eponym, diagnosis, & treatment

-De Quervain's [also toxic thyroiditis]
-Hyperthyroidism secondary to infection. Differentiate from Grave's by:
1. recent URI or viral infection
2. elevated CRP and ESR
3. radioactive I uptake. [I-131 uptake by Grave's is high, uptake by acute thyroiditis is low;
-Treatment for acute is oral steroids

Thyroid mass epidemiology and evaluation

-40-50% adults;
-Usually benign tumors but may be cysts [rare]; --Ultrasound is Gold Standard, Cysts usually resolve, but may needle aspirate

Thyroid nodule treatment

-Ignore unless >1.5 cm, then do US and/or aspirate
-If unsure, do I-131 uptake. Active uptake ["hot"] is OK. No uptake ["cold"] may be malignant -> biopsy

Four kinds of thyroid tumors

1. Papillary [75%, most female, rarely metastasize, treatment: resection];
2. Follicular [15%, women > 50 yrs, may metastasize to lung/bone, treatment: resection or I-131];
3. Medullary [5%, very aggressive, metastatic to liver, lung, bone; treatment: resection];
4. Anaplastic carcinomas [5%, very aggressive with poor prognosis, treatment: radiation/chemo]

Post-thyroidectomy treatment

The sequence is:
1. Whole-body I-131 scan to destroy any metastases;
2. High-dose RAI ablation; repeat in 1 year;
3. High-dose Levo-T4 for 5 yrs to ensure TSH is not present, [unidentified metastasis], then normal dose

Thyroid replacement drug that replaces endogenous T3

Liothyronine [Cytomel]; used in conjunction with Levothyroxine for patients with poor T4-> T3 conversion.

When thyroidectomy is done

When there is significant obstructive thyromegaly.
Otherwise, radio-iodine ablation is used.

Treatment for acute thyroiditis

Corticosteroids to reduce inflammation

Distinguishing cancerous thyroid nodules from benign

I-132 uptake scan:
"Hot" [I-131 uptake POS] are usually benign,
"Cold" [I-132 uptake NEG] are likely malignant-- biopsy!!

Only definitive thyroid cancer diagnostic procedure.

Biopsy [needle or tissue]

Relationship between thyroid CA & labs

None: Thyroid CA is not associated with T3/T4/TSH changes.

Adrenal cortex regions and hormones

Go Find Rex, Make Good Sex;
Granulosa [Mineralocorticoid-> aldosterone];
Folliculata [Glucocorticoid-> cortisol];
Reticularis [DHEA-> -> testosterone]

1st line Adrenal Insufficiency treatment and side effects

Adrenal insufficiency-> Addison's-> ADD cortisol!
-Hydrocortisone = Cortef 25-30 qDay, divided BID;
-Side effects: Weight gain, HTN, Immuosuppression, DM

Two hormones with mild mineralocorticoid activity

Progesterone & Deoxycorticosterone

Cortisol effects

Increase BP, Increase glucose [by gluconeogenesis], inhibit insulin, antidiuretic [water retention]

Cortisol diurnal cycle

Lowest 3 hrs into sleep;
Highest in early morning

Adrenal insufficiency name and hallmarks

-Addison's;
-Fatigue, dizzy, weakness, weight loss, diarrhea, hypotension, hyperpigmentation

Adrenal Insufficiency Types

-Primary: Adrenal dysfunction;
-Secondary: Ant pituitary fails to make ACTH;
-Tertiary: Hypothalamus fails to make CRH;
-Autoimmune: secondary to DM-1, Grave's, or Hashimoto's

Addisonian Crisis occurence, & signs and symptoms

-In untreated Addison patient or Addison patient with Infection or sepsis [often meningococcal septicemia = Wterhouse Friderichson];
-Fever, hypotension, vomiting, diarrhea, dehydration, weakness, , hypoglycemia,

2nd line adrenal insufficiency treatment

Prednisone or prednisolone. Has less mineralocorticoid activity then hydrocortisone

Mineralocorticoid replacement drug

Fludrocortisone [usually used with hydrocortisone in Addison's]

Adrenal excess condition

Cushing's

Ranked causes of Cushing's

1. Iatrogenic (corticosteroids/steroids);
2. Secondary (pituitary mass/tumor);
3. Primary (adrenal adenoma);
4. Ectopic tumor (Small cell lung CA producing ACTH)

Cushing's initial diagnostic lab test

Elevated cortisol in serum & 24-hr urine

Cushing's diagnostic details

Dexamethasone suppression test is NEG:
1. If ACTH: Absent/Low; Cortisol: Not suppressed by high Or low doses; Diagnosis is: Primary
2. If ACTH: Elevated; Cortisol: not suppressed by low, but is suppressed by high; Diagnosis is Secondary
3. If ACTH: Normal to Elevated; Cortiusol: Not suppressed by high OR low doses; Diagnosis: MEN

Cushing's signs and symptoms

Central obesity, Moon face, buffalo hump, hirsutism, amenorrhea, truncal striae, HTN, acne

Cushing's treatment

Iatrogenic: discontinue meds;
Secondary: Resection of pituitary tumor
Primary: Resection of adrenal adenoma
Follow resections by hormone replacement until ACTH rises again

Neuroendocrine adenomas that release catecholamines

Phaeochromocytoma

Phaeo signs and symptoms

HTN, tachy, red flushing, palpitations, diaphoresis, anxiety, HA

Phaeo diagnosis

Plasma free metanephrine (Epi metabolite) elevated [Gold standard], 24-hr urine metanephrines/catecholamines; MRI to localize
-May be MEN2A: parathyroid, pharochromocytoma, medullary thyroid tumor

Phaeo Tx

Resection following PHENOBENZAMINE (prevents severe HTN in surgery)

Phaeo contraindicated Rx

Beta Blockers (don't block alpha sites, get rebound HTN)

Diabetes Insipidus types & etiology; Tx

1. ADH deficiency from POST pit ; Tx: vasopressin replacement (Desmopressin) given as nasal spray, OR
2. Inability to bind ADH at collecting ducts; Tx: Hydrochlorothiazide

Calcium regulating glands; MOA

Parathyroids; Resorb Ca2+ from bone, Retain Ca2+ at gut (via Vit D) and recover Ca2+ at kidney

Hypoparathyroidism S/s

Hypocalcemia-> Muscle cramps/tetany, Parasthesia, Dry hair/skin, QT elongation, Brittle nails, Seizure

Hypoparathyroidism Tx

Ca2+ & Vit D replacement, monitor regularly to avoid arrhythmia (short QT) and Stones, Bones, Moan, Groans

Hyperparathyroidism S/s

Hypercalcemia-> Stones, Bones, Moans, Groans, Thrones

Parathyroid Tumor test

Sestamibi PT scan using Tc-99m isotope (uptake is faster in hyperthyroidism)

PT tumor resection indications

Under 65, cut it out. Under: monitor
Can't find ectopic tumor but have elevated Ca? Take out largest PT gland.

How are the various types of Adrenal Insufficiency diagnosed?

ACTH Stimulation test: "Cosyntropin" is given, then cortisol levels checked.
If no (or v. slight) cortisol increase: PRIMARY Addison's;
If 2-10X increase: SECONDARY
**For AI Adrenal Insufficiency, 90% in US, measurement of 21-hydroxylase autoantibodies is done

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