Secretin is a peptide hormone produced in the S cells of the duodenum, which are located in the intestinal glands. In humans, the secretin peptide is encoded by the SCT gene.
Secretin helps regulate the pH of the duodenum by
1) inhibiting the secretion of gastric acid from the parietal cells of the stomach and
(2) stimulating the production of bicarbonate from the ductal cells of the pancreas.
G cells in the antrum of the stomach release gastrin
I cells in upper small intestine release CCK
D cells in the pancreas & stomach secrete somatostatin
K cells secrete gastric inhibitory peptide, an incretin, which also promotes triglyceride storage.

Flashes and floaters are symptoms of vitreous detachment. The patient is at risk of retinal detachment and should be referred urgently to an ophthalmologist.

The most common causes of a sudden painless loss of vision are as follows:
– Ischaemic optic neuropathy (e.g. temporal arteritis or atherosclerosis)
– Occlusion of central retinal vein
– Occlusion of central retinal artery
– Vitreous haemorrhage
– Retinal detachment

The darkness of the cinema room will have caused halfway dilation of the pupil. This can cause an acute attack of angle closure glaucoma. The appropriate test to diagnose this is applanation tonometry.

This case presents with sensorimotor neuropathy secondary to his DM. The progression of the neuropathy, known dying-back neuropathy, is a distal axonopathy or axonal degeneration as where the sensorimotor loss begins distally and travels proximally.

Results of a randomized trial confirm that the antidepressant sertraline can be used safely in patients with recent MI or unstable angina and is effective in relieving depression in these patients.

There are theoretical reasons for believing that selective serotonin reuptake inhibitors (SSRIs), widely used to treat depression, might increase the risk of gastrointestinal bleeding. Gastroprotective drugs are advocated for high risk patients taking non-steroidal anti-inflammatory drugs, another class of drug that causes gastrointestinal bleeding.

Serotonin is released from platelets in response to vascular injury and promotes vasoconstriction and a change in the shape of the platelets that leads to aggregation. Platelets cannot themselves synthesise serotonin. SSRIs inhibit the serotonin transporter, which is responsible for the uptake of serotonin into platelets. It could thus be predicted that SSRIs would deplete platelet serotonin, leading to a reduced ability to form clots and a subsequent increase in the risk of bleeding.

The well established association between nonsteroidal anti-inflammatory drugs and upper gastrointestinal bleeding is estimated to result in 700-2000 deaths/year in the UK. This has led to the recommendation that patients in high risk groups should receive gastroprotection in the form of an H2 antagonist, proton pump inhibitor (lansoprazole), or misoprostol.

Proton pump inhibitors have been shown to reduce endoscopically diagnosed mucosal damage and heal ulcers induced by non-steroidal anti-inflammatory drugs but not to reduce the incidence of severe gastrointestinal bleeds.

Breast feeding has not been shown to increase the risk of transmission of HCV from mother to baby. This is simply a fact to memorize. The other answer choices are not the most accurate as there is no evidence-proven way to decrease the chance that baby will get HCV from the mother during the birth. About 5 out of every 100 infants born to HCV infected mothers become infected.

Philadelphia translocation, t(9;22), is a marker of poor prognosis in acute lymphoblastic leukaemia (ALL).

ALL is the malignancy of lymphoid progenitor cells affecting B or T cell lineage. This results in the arrest of lymphoid cell maturation and proliferation of immature blast cells (lymphoblasts), leading to bone marrow and tissue infiltration.

ALL is the most common type of childhood cancers. Its peak incidence is between two to three years of age.

Acute B lymphoblastic leukaemia (B-ALL) is the most common type of ALL, involving overproduction of B-cell lymphoblasts. It is manifested by low initial WCC and is associated with a good prognosis.

Poor prognostic factors for ALL include:
1. Pre-B cell or T-cell ALL (T-ALL)
2. Philadelphia translocation, t(9;22)
3. Age <2 years or >10 years
4. Male sex
5. CNS involvement
6. High initial WBC (e.g. >100 x 10^9/L)
7. non-Caucasian

Leukemoid reaction has a high LAP score.

Leukemoid reaction refers to leucocytosis occurring as a physiological response to stress or infection which may be mistaken for leukaemia, especially chronic myeloid leukaemia (CML). Leucocytosis occurs, initially, because of accelerated release of cells from the bone marrow and is associated with increased count of more immature neutrophils in the blood (left-shift). In order to differentiate, LAP score is used. Leukocytic alkaline phosphatase (ALP) activity is high in a leukemoid reaction but low in CML.

LAP score is high in:
1. Leukemoid reaction
2. Infections
3. Myelofibrosis
4. Polycythaemia rubra vera
5. Steroids, Cushing’s syndrome
6. Pregnancy, oral contraceptive pill

LAP score is low in:
1. CML
2. Pernicious anaemia
3. Paroxysmal nocturnal haemoglobinuria (PNH)
4. Infectious mononucleosis

Cataract is a condition characterized by clouding of the lens of the eye. This condition most frequently occurs due to age-related degenerative processes in the lens, but can also be associated with ocular trauma, metabolic disorders, side-effects of drugs, or congenital infections. The clouding causes distortion of light, as it passes through the lens, resulting in visual impairment and glare. Initially, a cataract presents discretely and may even go unnoticed, but the visual impairment worsens as the cataract grows larger.

Diagnosis is typically established on the basis of a thorough history and direct visualization of the cataract (by means of slit-lamp microscopy). Surgery is indicated with significant visual impairment and involves lens extraction and implantation of an artificial lens. Untreated cataracts eventually lead to complete blindness.

Sun burn reactions usually occur after individuals with a light skin tone have prolonged exposure to the sun. The usual symptoms are redness and itching of the skin. The best treatment plan would be further avoidance of sun exposure and the topical application of emollients. These are Ist degree burns and aggressive therapy is not required in such cases.

The most possible diagnosis is a pituitary tumour. Pituitary tumours compress the optic chiasm inferiorly and can cause visual field defects (bitemporal hemianopia or quadrantanopia). Temporal arteritis usually develops in older people and acute glaucoma usually requires a family history. Amaurosis fugax is classed as a stroke and usually leads to reversible unilateral vision loss. A subconjunctival haemorrhage does not typically produce the symptoms described.

The patient is most likely to have Bulimia nervosa. A young girl with a low body mass contributes to the low urea. Hypokalaemia and hyponatraemia are due to vomiting. Her urine sodium is also low.
– In Addison’s diseases, there are low levels of sodium and high levels of potassium in the blood. In acute adrenal crisis: The most consistent finding is elevated blood urea nitrogen (BUN) and creatinine. Urinary and sweat sodium also may be elevated.
– In Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) there is hyponatremia with corresponding hypo-osmolality, continued renal excretion of sodium, urine less than maximally dilute and absence of clinical evidence of volume depletion.

Interleukin 1 alpha and interleukin 1 beta (IL1 alpha and IL1 beta) are cytokines that participate in the regulation of immune responses, inflammatory reactions, and hematopoiesis. It is secreted mainly by macrophages and monocytes and acts as a costimulator of T cell and B cell proliferation.

MDMA commonly known as ecstasy or molly, is a psychoactive drug primarily used as a recreational drug. The desired effects include altered sensations, increased energy, empathy, and pleasure. Features of MDMA abuse include hyponatraemia, tachycardia, hyperventilation, and hyperthermia.

Bronchial carcinoids are uncommon, slow growing, low-grade, malignant neoplasms, comprising 1-2% of all primary lung cancers.
It is believed to be derived from surface of bronchial glandular epithelium. Mostly located centrally, they produce symptoms and signs of bronchial obstruction such as localized wheeze, non resolving recurrent pneumonitis, cough, chest pain, and fever. Haemoptysis is present in approximately 50% of the cases due to their central origin and hypervascularity.
Central bronchial carcinoids are more common than the peripheral type and are seen as endobronchial nodules or hilar/perihilar mass closely related to the adjacent bronchus. Chest X-ray may not show the central lesion depending on how small it is.

This case has hypercalcaemia most likely associated with the bony metastases from her pre-existing breast carcinoma. The most appropriate next step is to give Pamidronate 60mg intravenously, a bisphosphonate, to immediately inhibit bone resorption and formation.

Ethanol competes with ethylene glycol for alcohol dehydrogenase and thus, helps manage a patient with ethylene glycol toxicity.

Ethylene glycol is a type of alcohol used as a coolant or antifreeze
Features of toxicity are divided into 3 stages:
Stage 1: (30 min to 12 hours after exposure) Symptoms similar to alcohol intoxication: confusion, slurred speech, dizziness (CNS depression)
Stage 2: (12 – 48 hours after exposure) Metabolic acidosis with a high anion gap and high osmolar gap. Also tachycardia, hypertension
Stage 3: (24 – 72 hours after exposure) Acute renal failure

Management has changed in recent times:
Fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol.
Ethanol has been used for many years works by competing with ethylene glycol for the enzyme alcohol dehydrogenase this limits the formation of toxic metabolites (e.g. glycolaldehyde and glycolic acid) which are responsible for the hemodynamic/metabolic features of poisoning.
Haemodialysis has a role in refractory cases.

There is a strong suspicion of Thrombotic Thrombocytopenic Purpura (TTP) in this patient as he presents with neurological changes (from confusion to convulsions and coma), fever, haemolysis, thrombocytopenia, and renal failure. Additionally, TTP cases may present with jaundice, splenomegaly, and hypertension as seen in this patient. With a diagnosis of TTP, recent studies have shown that platelet transfusion is not recommended in this case because it has been shown to increase the risk for arterial thrombosis and mortality possibly due to increased aggregations.

The prompt is suggestive of celiac disease as an aetiology. The antibody that is used primarily to suggest this diagnosis is anti-tissue transglutaminase antibody. You can also check anti-gliadin and anti-endomyseal antibodies, although anti-TTG antibodies are now the preferred test. To get an official diagnosis you must have a tissue diagnosis (biopsy). Anti-smooth muscle antibodies would be seen in autoimmune hepatitis. Anti-thyroid antibodies are not at all related to this, and are associated with thyroid. Anti-nuclear antibodies are non-specific.

Confusion and pink mucosae are typical features of CO poisoning.
The patient often presents, most commonly with headaches, and other symptoms like malaise, nausea, and dizziness.

Carbon monoxide (CO) poisoning, considered as the great imitator of other diseases as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.

Features of carbon monoxide toxicity
– Headache: 90% of cases
– Nausea and vomiting: 50%
– Vertigo: 50%
– Confusion: 30%
– Subjective weakness: 20%
– Severe toxicity: ‘pink’ skin and mucosae, hyperpyrexia, arrhythmias, extrapyramidal features, coma, death

Treatment:
Use of Hyperbaric oxygen therapy (HBOT) for treating mild to moderate CO poisoning is not routine.
The selection criteria for HBOT in cases of CO poisoning include:
• COHb levels > 20-25%
• COHb levels > 20% in pregnant patient
• Loss of consciousness
• Severe metabolic acidosis (pH <7.1)
• Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)

A muscarinic receptor antagonist (MRA) is a type of anticholinergic agent that blocks the activity of the muscarinic acetylcholine receptor. There are six antimuscarinic drugs currently marketed for the treatment of urge incontinence: oxybutynin, tolterodine, propiverine, trospium, darifenacin, and solifenacin.

Azathioprine therapy can cause acute myelosuppression. Toxicity is in part caused by the incorporation of azathioprine-derived 6-thioguanine nucleotides (6-TGN) into deoxyribonucleic acid (DNA). The enzyme thiopurine methyltransferase (TPMT) plays an important role in azathioprine catabolism.

Absolute contraindications for fibrinolytic use in STEMI

Prior intracranial haemorrhage (ICH)
Known structural cerebral vascular lesion
Known malignant intracranial neoplasm
Ischemic stroke within 3 months
Suspected aortic dissection
Active bleeding or bleeding diathesis (excluding menses)
Significant closed head trauma or facial trauma within 3 months
Intracranial or intraspinal surgery within 2 months
Severe uncontrolled hypertension (unresponsive to emergency therapy)
For streptokinase, prior treatment within the previous 6 months

Betahistine is a histamine analogue that has been the mainstay treatment drug for Meniere’s disease.

Psoriasis is a long-lasting autoimmune disease which is characterized by patches of abnormal skin. These skin patches are typically red, itchy, and scaly commonly on the extensor surfaces. Psoriasis is associated with an increased risk of psoriatic arthritis, lymphomas, cardiovascular disease, Crohn’s disease, and depression. Psoriatic arthritis affects up to 30% of individuals with psoriasis. Psoriasis is mediated by type 1 helper T cells which are involved in the cell mediated response, rather than type 2 helper T cells

Breast cancer has a lower incidence in HIV positive patients. Seminoma, Hodgkin’s disease, anal cancer, and non-small cell lung cancer are all increased incidence. Memorize this breast cancer fact.

12-lead electrocardiography and transthoracic echocardiography are recommended as a screening method for family members of patients with HCM.

This is most likely describing irritable bowel syndrome (IBS). Symptoms are either diarrhoea, constipation, or both, abdominal pain, bloating, of varying duration. It is a functional, not an organic problem, as far as research shows at this point. It is essentially a diagnosis of exclusion. Treatment is a high fibre diet with fluids. Caffeine should be avoided as this can worsen symptoms.

Spironolactone is an aldosterone antagonist which acts in the distal convoluted tubule. It is a potassium-sparing diuretic that prevents the body from absorbing too much salt and keeps the potassium levels from getting too low. Spironolactone is used to treat heart failure, high blood pressure (hypertension), or hypokalaemia (low potassium levels in the blood).

Othello syndrome (OS) is a type of paranoid delusional jealousy, characterized by the false absolute certainty of the infidelity of a partner, leading to preoccupation with a partner’s sexual unfaithfulness based on unfounded evidence. OS has been associated with psychiatric and neurological disorders including stroke, brain trauma, brain tumours, neurodegenerative disorders, encephalitis, multiple sclerosis, normal pressure hydrocephalus, endocrine disorders, and drugs.