Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FRACP 2023 Cram Homicrons Edition > Endo > Flashcards

Endo Flashcards

1
Q

Dx on CXR?

A

Rachitic rosary
Calcipenic ricketts
Expect low Ca/vit D, elevated PTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Dx on CXR?

A

Osteopetrosis
Skeletal dysplasia = hardening of the bones
- Altered bowel gas pattern & hepatosplenomegaly also consistent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Patterns of hypoglycemia (inc insulin/ketones)

A

Low BSL/ketones & high insulin
- Hyperinsulinemia
(congenital)
- Insulin prevents breakdown fat > FFA = low ketones

Low BSL/insulin, high ketones
- Indequete substrate (fasting)
- Defect in counter regulatory hormones
- Defecits iin glycogenolysis/GNG

Low BSL, ketones & insulin
- FAO defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Features of 21-OH CAH?

A

CYP21a2 mutation
Lack 21-OH enzyme =
build up of 17OHP

↓ Cortisol
↓ Aldosterone
↑ Sex steroids

Classic
- Simple virilising 25% (enough aldosterone, lack sex steroids)
- Severe salt wasting 75%
(no sex steroids or aldo)

Hypotension, hyponatremia & hyperkalemia
Metabolic acidosis

Ambiguous genitalia in females
Virilisation in males/females

Non-classical
- Late onset
- Androgen excess without genital ambiguity
(pubarche, hirstutism etc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Features of 17a-OH CAH

A

CYP17A1 mutation

Normal cortisol
↑ Aldosterone
↓ Sex steroids
(Inc DOC/corticosterone)

Hypertension, hypernatremia, hypokalemia,
Metabolic alkalosis

Sexual infantilism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Features of 11b-OH CAH

A

CYP11B1 mutation

↓ Cortisol
↑ Aldosterone
↑ Sex steroids (androgens), ↓ Oestrogen
(inc DOC, 11-DOC)

Hypertension, hypernatremia, hypokalemia
Metabolic alkalosis

Ambigous genitalia (female)
Virilisation (M&F)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Features of 3b-OHS CAH

A

HSD3B2 mutation

↓ Cortisol
↓ Aldosterone
↓ Androgens (males, ↑ in females)
(increased DHEA)

Hypotension, hyponatremia, hyperkalemia
Metabolic acidosis

Ambiguous genitalia in males, mild in females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Genetics of 21-OH CAH- what correlates to disease severity?

A

2 steroid 21-hydroxylase genes
– CYP21P
- CYP21(pseudogene with 9 mutations)

> 90% of mutations causing 21-hydroxylase deficiency are recombinations between CY21 and CYP21P

20% are deletions generated by unequal meiotic crossing over

Gene conversion – caused by non-reciprocal transfer of deleterious mutations

Disease severity correlates with mutations – ie. salt wasting disease results from mutations on both alleles that completely destroy enzymatic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Outline types of Cushing’s Syndrome

A

CS= glucocorticoid excess
CD = caused by pituitary adenoma

Moon facies, buffalo hump, obesity, impaired growth
HTN, hyperglycemia, osteoporosis

ACTH dependent (central)
1. Pituitary adenoma
- Most common >7yrs
- Assoc MEN1

  1. Ectopic ACTH production
    - Pancreatic Ca, neuroblastoma
    - HTN more common

ACTH independant (adrenal)
1. Iatrogenic
2. Adrenal adenoma
3. Syndromic
- Primary pigmented nodular adrenocortical disease
- McCune Albright

Ix: Elevated midnight cortisol (usually nadir), urinary free cortisol,
- Elevated dexa supression test >5 (not supressed in ACTH independant, only larger dose supresses in ACTH dependant)
- CRH: IV bolus of CRH
ACTH-dependent Cushing’s = exaggerated ACTH and cortisol response
ACTH-independent (eg. adrenal tumour) = no increase to ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Epi/genetics of T1DM?

A

Most common form in childhood
Bimodal peak 4-6yrs, 10-14yrs

Genetics:
- 85% have no FHx
- MZ concordance 30% in 10yrs
- Both parents- up to 30%
- HLADR3/4 + DQ2/8 = susceptible (DR2 protective)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Patho of T1DM

A

Patho:
Trigger in susceptible host (geography, viral infections, diet, SES)
- T cell mediated B cell destruction
- Preclinical autoimmunity
- Symptoms when 90% destroyed
- Decreased gluc uptake in liver, muscle, fat storage
- Shunts to GNG from fat/protein
- Transient remission with therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the dawn phenomenon in T1DM

A

Early morning (2-8am) hypoglycaemia due to overnight GH secretion + ↑ insulin clearance
Occurs in peri-pubertal + pubertal years, may result in sub-optimal morning insulin levels
Manage with ↑ evening protophane dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Somogyi phenomenon in T1DM

A

Rebound hyperglycaemia from late night/ early AM hypoglycaemia,
Due to exaggerated counter regulatory response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Antibodies in T1DM and progression?

A
  1. Anti-insulin antibodies (appears first then disappears with insulin therapy)
  2. Anti GAD
  3. Anti- islet cell cytoplasmic ABs (70% prevalence in newly diagnosed)
  4. Anti-IA2- best predictor for T1DM development
  5. Anti-ZNT8: lecrease rapidly over time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Autoimmune associations in T1DM

A

More common in HLADR3 carriers
- 7-15% coeliac disease within first 6yrs
- 6% prevalence of vitiligo (6x background population)
- 2-5% hypo, 1% hyperthyroidism (HLADQB1)
- APS2/IPEX
- Adrenal disease 21OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Short, intermediate and long acting insulins?

A

Short: Novorapid/actrapid/ humalog
Intermediate: humulin/protophane
Long: Levemir/lantus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Earliest sign of diabetic nephropathy?

A

Hyperalbuminuria defined as albumin excretion between 30-300 mg/day (20-200 mcg/min)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Mauriac syndrome

A

Dwarfism associated with glycogen-laden liver

Complication of chronic low insulin levels in T1DM

19
Q

Mortality of cerebral oedema in T1DM and risk factors prevention?

A

Cerebral oedema
- 50-60% of T1DM related deaths
- Occurs 6 and 12 hours after starting therapy
- Risk factors = first presentation, long history of poor control, young age (< 5 yr)

20
Q

Risk factors for T2DM

A

Obesity, +ve FHx (one parent 40%, two parent 60%, MZ 90%), female/PCOS, gestational, glut2 defect

21
Q

What percentage of patients with T2DM present with DKA vs HHONK?

A

5-15% both

22
Q

What percentage of patients with T2DM present with DKA vs HHONK?

A

5-15% both

23
Q

What symptom of T2DM is a good marker of insulin resistance?

A

Acanthosis nigricans – marker of insulin resistance found in 50-90% of youth with T1DM

24
Q

Rx T2DM

A

OHGs:
1. Metformin monotherapy is treatment of choice (metabolic acidosis/GI upset)
2. Sulfonylureas: inc insulin secretion from B cells (low BSL, weight gain)
3. Acarbose: ↓glucose absorption from GI tract (GI Sx)
4. GLP 1 analogues: improve pancreatic islet glucose sensing (N&V)
5. DPP-IV inhibitors: Prolong GLP1 action, leading to improved beta-cell sensing (hypersensitivity/headache)
6. SLGT2 inhibitor (pee out glucose) = risk inc infection
7. Thiazolidinediones: ↑ insulin sensitivity (weight gain significant)

Insulin if:
HbA1c >9%
Severe hyperglycaemia (serum glucose > 15 mmol/L)
Ketosis/ketoacidosis

25
Q

MODY syndromes & overview

A

2-5% of DM diagnosis
AD, younger onset

Reduced insulin response to glucose:
MODY 1 (<10%) - HNF4a
- Rx sulfonylurea
MODY 2 (15-30%)- GCK
- Mild/non progressive
- Rx diet
MODY 3 (65%)- HNF1a most common
- Rx sulfonylurea

Pancreatic dysfunction:
MODY 4- IPF1
MODY 5- HNFb
MODY 6- NEUROD

26
Q

Vitamin D homeostasis

A
27
Q

RFs/protective factors for presentation with DKA in T1DM

A

RFs: <2yrs, delay in diagnosis, minority group, COVID pandemic

Protective: family history, screening programmes

28
Q

2 week boy presents with lethargy, vomiting

Na 124, K+ 8, glucose 1.8

Dx & Mx?

A

Salt wasting crisis in setting of 21-OH def (90% of cases)

  • XY patients may not have any physical features
  • Consider in any child <5wks with high K/low Na

Rx: fluid resuscitation, dextrose if low BSL, glucocorticoid Rx (steroid profile prior)

29
Q

46XY- ambiguous genitalia, around puberty undergoes significant masculinisation- growth of penis/testes

A

5a reductase deficiency

SRD5A gene
-AR
-Defective conversion of testosterone to DHT (role in EXTERNAL genitalia during embryogenesis)

  • Normal testosterone
  • Normal to low DHT
  • HIGH ratio testosterone:DHT
30
Q

46XY with female external genitalia, breasts & primary amenorrhoea, palpable gonads in labia

A

Complete androgen insensitivity
- AR
- Serum testosterone normal
- AMH present
- Androgen receptor does not sense

31
Q

46XY no uterus, undervirilised male genitalia with high T/DHT, normal ratios on HCG test T/DHT

A

Partial androgen insensitivity

32
Q

46XX, male external genitalia, uterus, high testosterone, high K+, low Na

A

21-OH

33
Q

DSDs at increased risk of malignancy

A

Risk of germ cell malignancy
HIGH
- Gonadal dysgenesis + Y chromosome positive + Intra-abdominal gonad
-Partial insensitivity syndrome + intra-abdominal gonad >50%

INTERMEDIATE
- Turner + Y
- GD + Y + scrotal gonads
- PAIS + scrotal gonads

LOW – No Y
-CAIS
- 46 XX ovotesticular DSD
- Turner, No Y chromosome

34
Q

Define precocious puberty?

A

= puberty < age 8 in girls or < 9 in boys

35
Q

How to differentiate central vs peripheral cause precocious puberty

A

Peripheral
- High testosterone, low FSH/LH
- Asynchronous development
- Paraneoplastic (HCG stimulates LH receptor)- germ cell tumors- CNS/gonads/liver/mediastinum

Central
- High testosterone, high LH/FSH

36
Q

Basics of calcium metabolism

A

99% stored in bone
- Resorption (breakdown): osteoclasts - clasts release calcium
- Mineralisation (bone formation): osteoblasts (blasts build)

1% in serum
- 50% ionised
- 40% albumin/globulin (influenced by pH)
- 10% in complexes- phosphate/citrate etc

10% excreted via urine
90% reabsorbed via PCT/LOH/DCT
- Acidosis increases excretion
- Alkalosis decreases excretion

37
Q

What receptor governs Ca2+ metabolism and where is it found?

A

Calcium sensing receptor
- Parathyroid chief cells
- Renal tubular cells
- C cells of thyroid

Regulates PTH/calcitonin release & Ca2+ renal absorption

38
Q

Differentiate Ricketts from osteomalacia?

A

Rickets = deficient mineralisation at the growth plate + architectural disruption of this structure

Osteomalacia = impaired mineralisation of the bone matrix

39
Q

Signs of Ricketts

A
  • Widened growth plate
  • Metaphyseal fraying
  • Cupping
  • Widening of distal metaphysis
40
Q

Genetic cause of pseudohypoparathyroidism

A

Pseudohypoparathyroidism = HypoCa,
hyperPhos, and raised PTH.

Allbright’s hereditary osteodystrophy
Imprinting disorder
- Maternally inherited GNAS mutations =
Allbright’s hereditary osteodystrophy +
pseudohypoparathyroidism.

  • Paternally inherited = Allbright’s
    hereditary osteodystrophy without
    endocrinopathy
    (pseudopseudohypoparathyroidism).
41
Q

Most common antibody at Dx T1DM

A
  1. ICA: Islet cell antibodies- 90%
    - Against cytoplasmic proteins in the beta cell
  2. GAD-65: Antibodies to glutamic acid
    decarboxylase- 80%
  3. IAA: Insulin autoantibodies- 75%
  4. IA2: antibodies to protein tyrosine phosphatase- 70%
42
Q

Detail these regions of bone development

A

Distal -> proximal:
Germinal zone
- irregularly scattered chondrocytes

Proliferation zone
- Chondrocytes divide, flatten and form columns
- Creates lengthening

Hypertrophic zone
- Maturation
- Chondrocytes differentiate, enlarge and die
- Bone is calcified
- Regulated by phosphate

Ossification zone
- Matrix formed by chondrocytes becomes template for osteoblasts to build bone

43
Q

Features of metabolic syndrome

A
  • Diabetes
  • Hypertension
  • Dislipidaemia
  • Abdominal Obesity
    Association with other conditions
    e.g. NASH, PCOS, OSA

FRACP 2023 Cram Homicrons Edition (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions