AUBF

Diabetes insipidus

inability to concentrate urine

Diabetes insipidus

Q: If a patient has polyuria with a low specific gravity, which diagnosis fits best?

Uroerythrin — pink pigment with urates.

Q: Which urine pigment is most associated with a pink color in refrigerated specimens due to amorphous urates?

Temperature correction.

A refractometer reading does NOT require which correction that a urinometer might?

Protein error of indicators.

On reagent strips, the principle for detecting protein is called?

Pass-Through Phenomenon

A positive Clinitest could be falsely negative for very high glucose because of?

β-hydroxybutyric acid (~78%).

Which ketone predominates in urine during ketosis?

Speckled pattern.

On blood reagent strip, an intact RBC produces what pattern?

pH pad (double indicator system).

Which reagent strip pad uses methyl red + bromthymol blue?

Detects esterase from lysed neutrophils

Which is TRUE about leukocyte esterase (LE)?

Nitrite test (Griess reaction).

Which reagent strip test detects nitrate-reducing bacteria?

Isosthenuria — loss of concentrating ability.

: Urine specific gravity 1.010 indicates what?

: Non-albumin proteins (e.g., Bence-Jones).

Positive SSA but negative strip protein suggests?

Yeast bud, RBCs don’t; Brownian motion differs.

How to differentiate yeast from RBCs?

Chronic/severe renal disease (late stage).

: Waxy casts indicate what?

Obstructive jaundice.

: Low/absent urobilinogen suggests?

False — some squamous cells may be present.

Are epithelial cells always absent in clean-catch urine?

Chronic renal failure, tubular dilation

Broad casts suggest?

Hemoglobin: red plasma; Myoglobin: clear plasma

Hemoglobinuria vs. myoglobinuria — plasma clue?

: False — they form in acidic or neutral urine.

: Calcium oxalate crystals form only in acidic urine?

No — polyelectrolyte pKa change, no correction.

Does reagent strip SG require temperature correction?

RBC casts.

Which cast is diagnostic of glomerulonephritis?

WBC casts.

Which cast indicates pyelonephritis?

Lipid-laden RTECs in nephrotic syndrome.

: What are oval fat bodies?

Cholesterol esters in oval fat bodies.

Maltese crosses under polarized light suggest?

Tamm-Horsfall (uromodulin)

What protein forms cast matrix?

Acute glomerulonephritis.

Child with hematuria, edema, RBC casts post-strep?

Early diabetic nephropathy & CV risk.

Microalbuminuria (20–200 mg/L) in diabetes means?

: Non–nitrate reducers (Enterococcus, Staph sapro).

Pyuria but nitrite negative — cause?

Nephrogenic diabetes insipidus.

: Infant with low SG despite normal ADH?

Obstructive jaundice.

Bilirubin positive, urobilinogen low?

1200–1500 mL (range: 600–2000 mL).

Normal daily urine output in adults?

Oliguria: <400 mL/day. Anuria: complete cessation of flow.

: Differentiate oliguria vs. anuria.

Hematuria: red & cloudy. Hemoglobinuria: red & clear.

What urine color change suggests hemoglobinuria vs. hematuria?

Rotten eggs odor.

What odor is linked with cystinuria?

Double sequential enzyme: glucose oxidase → peroxidase → chromogen.

What’s the principle of the urine glucose reagent strip?

160–180 mg/dL

Renal threshold for glucose?

Ammonium sulfate precipitation (Blondheim’s test).

Ammonium sulfate precipitation (Blondheim’s test).

True.

Only conjugated bilirubin can appear in urine — True or False?

: Ehrlich reaction (p-dimethylaminobenzaldehyde).

Urobilinogen reagent strip principle?

Watson-Schwartz test.

Which test differentiates urobilinogen from porphobilinogen?

Trichomonas vaginalis (pear-shaped, darting movement).

Parasite most commonly found in urine?

Schistosoma haematobium

Which parasite in urine is linked to bladder cancer?

Bacterial vaginosis (Gardnerella vaginalis)

'Clue cells' in urine sediment indicate what?

: Neutrophils with sparkling granules in hypotonic urine

Glitter cells are what type of cells?

Tamm-Horsfall protein (uromodulin)

What is the major matrix protein of casts?

Rapidly Progressive (Crescentic) GN.

Which renal disorder shows 'crescentic' GN with poor prognosis?

Goodpasture’s syndrome

Which syndrome combines hematuria + hemoptysis?

Anti-GBM antibody

What antibody is diagnostic in Goodpasture’s?

: ANCA (anti-neutrophil cytoplasmic antibody).

What antibody test supports granulomatosis with polyangiitis?

Alport syndrome.

Which inherited renal disorder presents with deafness and ocular abnormalities?