3rd Year Lab Med

What is the recommended triple therapy for H.pylori infection?

Pantoprazole + Amoxicillin + Metronidazole

What stain is used to detect H.pylori under microscopy?

Silver Stain

What parasite is commonly transmitted through contact lenses?

Acanthamoeba

What parasite is commonly transmitted by the anopheles mosquito?

Malaria (Plasmodium)

What parasite is commonly transmitted by faecally contaminated water?

Entamoeba Histolytica

What parasite is commonly acquired from contact with warm soil/sand?

Cutaneous Larva Migrans (Ancylostoma)

What parasite is commonly transmitted by deer ticks?

Babesia

What parasite is commonly acquired through interaction with cat faeces

Toxoplasma

What parasite is commonly transmitted by the Triatomine Bug

Trypanosoma Cruzi

Congo Red Stain is used in the diagnosis of what illness?

Amyloidosis

Giemsa stain is used in the detection of what organisms?

Trophozoites (e.g. babesia)

What 2 stains are used in the microscopic diagnosis of liver cirrhosis?

1. Trichrome Stain

2. Reticulin Stain

What stain is used in the diagnosis of Tuberculosis?

Ziehl-Neelsen Stain

Which stain is used in the diagnosis of alpha-1-antitrypsin deficiency?

PAS (periodic acid Schiff)

What stain is used in the diagnosis of hereditary haemochromatosis?

Prussian Blue

What combination of stains is used in the diagnosis of Barrett's Oesophagus?

PAS + Alcian Blue

What is the likely causative organism for Blepharitis and Dacryocystitis?

Staph Aureus

Schaumann Bodies & Asteroid Bodies are associated with what illness?

Sarcoidosis

Aschoff bodies are associated with what disease?

Rheumatic fever

The presence of crescents on renal biopsy is linked to what illness?

Rapidly progressing glomerulonephritis

The effacement of podocyte foot processes is associated with what renal disease?

Minimal change disease

What is Alagille syndrome?

an autosomal dominant condition involving liver, kidneys, heart and others. In liver results in bile duct abnormalities (drop out, absence)

What is Mirizzi syndrome?

a common hepatic duct obstruction caused by extrinsic compression from an impacted stone in the cystic duct or infundibulum of the gallbladder

What is Carcinoid syndrome?

a number of symptoms caused by the release of humoral factors such as polypeptides, prostaglandins, and biogenic amines, mostly released from well-differentiated neuroendocrine tumors - most commonly of the midgut that metastasize to the liver

What is Zollinger-Ellison Syndrome?

group of symptoms comprised of severe peptic ulcer disease, gastroesophageal reflux disease (GERD), and chronic diarrhea caused by a gastrin-secreting tumor of the duodenum or pancreas (gastrinoma triangle) that results in increased stimulation of acid-secreting cells of the stomach.

What is Cushing's syndrome?

excessive cortisol production

A 45-year-old patient presents with abdominal pain, abdominal distension, and hepatomegaly. Doppler ultrasound reveals thrombosis in the hepatic veins and ascites.

Budd-Chiari Syndrome - occlusion of the hepatic veins,

What is Lemierre's Syndrome?

Infectious thrombophlebitis of IJV, often occurring as a complication of fusobacterium necrophorum

What is Boerhaave syndrome?

spontaneous perforation of the esophagus that results from a sudden increase in intra-oesophageal pressure (e.g. vomiting) combined with negative intrathoracic pressure. Complication of Mallory-Weiss Tears

A 23-year-old man with a family history of kidney disease presents with microscopic hematuria and progressive hearing loss. Kidney biopsy reveals lamellated and split glomerular basement membranes on electron microscopy.

Alport Syndrome - a genetically heterogeneous disorder characterized by nephritic syndrome, often with sensorineural deafness and less commonly ophthalmologic symptoms

A 40 year-old male refugee from Yemen presenting with an acute diarrhoeal illness

shortly after his arrival in Ireland, passing what were described as 'rice water' stools

Cholera (Vibrio Cholerae)

A 70 year-old male who has been on a Medicine for the Elderly ward for 4 weeks

develops an acute episode of vomiting and diarrhoea. Several other patients on this

ward have had similar symptoms during the past week.

C. diff Infection

A 7 year-old girl who presented to the hospital with bloody diarrhea and is now found

to have renal failure

Verotoxigenic E. coli - haemolytic uraemic syndrome

A 20 year-old university student who consumes a Chinese take-away that includes

chicken and fried rice has a vomiting illness within 30 minutes of consuming the meal.

Bacillus cereus

A 6 year-old child is brought to her General Practitioner by her parents with a short

history of waking at night with peri-anal itching.

Enterobius Vermicularis (pinworms)

What liver condition is suggested by an AST: ALT > 2:1

alcoholic liver disease

What condition is characterised by ↑ ALP + ↑ GGT + Normal AST, ALP, Bilirubin

Intrahepatic cholestasis (PBC)

A 28-year-old man presents with intermittent mild jaundice triggered by fasting or illness. ↑ Bilirubin but AST, ALT, ALP, GGT, and other labs are normal?

Gilbert's Disease

↑ ↑ AST + ↑ ↑ ALT suggests what pattern of illness?

Hepatocellular

↑ALP + Normal GGT in adolescents is suggestive of what?

Normal bone growth - important to use paediatric reference ranges

↑ALP + Normal GGT in adults is suggestive of what?

Bone disease (Paget's, metastasis)

Charcot's triad (RUQ pain, jaundice, fever) is associated with what condition?

Cholangitis

Elevated serum amylase and lipase on a clinical presentation of severe epigastric pain is suggestive of what?

Acute pancreatitis

What might explain an isolated rise in GGT?

alcohol excess

What illness presents with elevated ALT and AST, with a high anti-smooth muscle antibody (ASMA) and elevated immunoglobulin G (IgG) levels

Autoimmune hepatitis

What tests can be used to assess the synthetic function of the liver?

PT, Glucose, Albumin

Rokitansky-Aschoff sinuses on histology are associated with what illness?

chronic cholecystitis

Retinal roth spots are associated with what illness?

Infective endocarditis

What is the likely causative pathogen in infective endocarditis involving native valves?

Staph. aureus

Rheumatic fever is caused by what pathogen?

Strep pyogenes (Group A Strep)

Antischkow cells ('owl's eyes') are associated with what condition?

Rheumatic heart disease

fish mouth appearance of aortic/mitral valve is associated with what illness?

chronic rheumatic fever - rheumatic heart disease

What is Dressler's Syndrome?

form of pericarditis tends to occur weeks to months after myocardial infarction. It is an autoimmune response triggering systemic inflammation, affecting other serous membranes as well such as the pleura.

What is a classic clinical presentation of pericarditis?

radiation to the trapezius ridge

What is the recommended treatment of pericarditis involving pericardial effusion?

pericardiocentesis

What virus is most commonly associated with viral myocarditis?

Coxsackie virus B3

Borrelia burgdorferi is the causative organism of what illness?

Lyme Disease

What is a common ECG presentation of myocarditis?

Sinus tachycardia +/- ST segment or T wave changes (typically concave)

When is the Dallas Criteria used?

following endomyocardial biopsy in the diagnosis of myocarditis

What is the histological presentation of hypertrophic myocarditis?

Myocyte hypertrophy

Myocyte disarray

Interstitial fibrosis

What is the most common genetic cause of hypertrophic myocarditis?

missense point mutation of sarcomeric proteins

What is Loeffler Endomyocarditis?

the abnormal infiltration of eosinophils into the endomyocardium, with subsequent tissue damage and fibrosis resulting from eosinophil degranulation, eventually leading to impaired diastolic function and restrictive ventricular filling

What are the microscopic characteristics of cardiac tissue 12-18 hours post-MI?

Coagulative necrosis,

Contraction band necrosis

Nuclear Karryorhexis

What are examples of endogenous compounds that cause direct toxic injury to the tubules?

Myoglobin, Haemoglobin

What drugs can cause tubulointerstitial nephritis?

Antibiotics, NSAIDs, PPIs

What are the extrapulmonary manifestations of TB?

Lupus Vulgaris

Tuberculosis epididymitis

Pott's disease (spinal TB)

Tuberculous meningitis

What pathogen is the most common cause of soft tissue infection in humans following bites or scratches from dogs and cats?

Pasteurella multocida

High serum levels of unconjugated bilirubin is associated with what condition?

haemolytic anaemia

The majority of patients (95%) with coeliac disease are positive for what gene?

HLA DQ2

What antibody test is diagnostic for Coeliac disease?

anti-tissue transglutaminase (tTG)

A patient with an uncomplicated UTI is most likely to be infected with what organism?

E. coli

Which UTI-causing organism is associated with the presence of renal calculi?

Proteus spp.

What organisms are associated with urinary catheter-associated UTIs?

Klebsiella spp

Staph epidermidis

Staph aureus

Pseudomonas aeruginosa

What changes seen on duodenal biopsy are associated with Coeliac disease?

Presence of villous atrophy leading to a flat mucosa

Crypt cell hyperplasia

Intraepithelial cell lymphocytosis

Inflammatory cell infiltration of the lamina propria

A 25-year-old backpacker recently returned from a hiking trip in a remote area. They report foul-smelling, greasy stools and bloating. Stool antigen test is positive.

Giardia infection

A 10-year-old child presenting with sudden onset vomiting, watery diarrhea, and fever after attending a school picnic. Symptoms resolve within 48 hours

Norovirus infection

A 40-year-old man with episodic abdominal pain and bloody diarrhea. Colonoscopy shows skip lesions and cobblestoning of the bowel.

Crohn's disease

A 30-year-old woman with pruritus, fatigue, and jaundice. Antimitochondrial antibodies (AMA) are positive, and imaging shows no biliary obstruction.

Primary biliary cholangitis

The majority (98%) of cases of PBC are positive for what AMA subtype?

AMA-M2

A 40-year-old man with elevated serum ferritin and transferrin saturation. Liver biopsy reveals iron deposition. Genetic testing confirms HFE mutation.

Hereditary haemochromatosis

Ursodeoxycholic acid is used to slow the progression of what disease?

Primary biliary cholangitis

A 40-year-old woman presents with tearing chest pain radiating to the back. Blood pressure differs by 30 mmHg between the arms.

Aortic dissection

A 47-year-old man presents with fatigue, syncope, and palpitations. He spent much of his life in a rural area of South America. ECG reveals left bundle branch block, and echocardiography shows apical aneurysm formation. What diagnostic test would you order?

Serologic testing for Trypanosoma cruzi

A 55-year-old man presents with worsening ankle oedema and abdominal fullness over several months. He reports an episode of tuberculosis decades ago. Echo reveals pericardial thickening with impaired ventricular filling, and catheterization confirms equalization of diastolic pressures.

Constrictive pericarditis (secondary to tuberculous pericarditis)

A 25-year-old man presents with hemoptysis, acute kidney injury, and hematuria. Serum testing reveals linear deposits of IgG along the glomerular basement membrane on immunofluorescence.

Goodpasture Syndrome

What cells are granulomas made up of?

Epithelioid histocytes

What is the cause of most necrotising granulomatous inflammation?

Mycoplasma tuberculosis infection

What are the causative organisms of MAC lung disease (nontuberculous)

Mycobacterium intracellulare & Mycobacterium avium

Rasmussen's aneurysm is associated with what disease?

Tuberculosis

spindle cell pseudotumours can mimic sarcoma in immunocompromised patients with which infection?

Tuberculosis

how are sarcoid granulomas diagnosed?

bronchoscopy,

endobronchial ultrasound, fine needle aspirate (EBUS-FNA)

Tx of idiopathic pulmonary fibrosis

Pirfenidone

what blood test is important in the diagnosis of granulomatosis with polyangiitis?

ANCA

causes of metabolic acidosis (↓HCO3) with a high anion gap?

diabetic ketoacidosis

lactic acidosis

toxins e.g. ethanol, methanol, salicylates

renal failure

examples of extracellular buffers

phosphate, bicarbonate

causes of metabolic acidosis (↓HCO3) with a normal anion gap?

renal tubular acidosis, diarrhoea

how does the kidney regulate HCO3 ?

1. Reabsorption of HCO3

2. Generation of HCO3 in DCT

3. Titratable Acidity

Causes of metabolic alkalosis (↑HCO3)?

GI losses

Diuretic therapy

Endocrine disturbances (mineralocorticoid excess, Cushing's syndrome

Serum ACE will be increased in the majority of patients with...

sarcoidosis

What are the primary risk factors associated with the development of ASCVD?

Dyslipidaemia

Hypertension

Obesity/T2DM