Soluble guanylyl cyclase (GC-1) is the primary receptor of nitric oxide (NO) in smooth muscle cells and maintains vascular function by inducing vasorelaxation in nearby blood vessels. GC-1 converts guanosine 5′-triphosphate (GTP) into cyclic guanosine 3′,5′-monophosphate (cGMP), which acts as a second messenger to improve blood flow.

The main mechanism of fibrate drugs is activation of gene transcription factors known as PPARs, particularly PPAR-α, which regulate the expression of genes that control lipoprotein metabolism. There are several consequences of PPAR-α activation, which reduce circulating LDL cholesterol and triglycerides and increase HDL cholesterol.

The following drugs should be used as normal during pregnancy:
short acting β2 -agonists
long acting β2- agonists
inhaled corticosteroids
oral and intravenous theophyllines

Use steroid tablets as normal when indicated during pregnancy for severe asthma. Steroid tablets should never be withheld because of pregnancy.
If leukotriene receptor antagonists are required to achieve adequate control of asthma then they should not be withheld during pregnancy.

The following are conditions commonly associated with pyoderma gangrenosum:
Inflammatory bowel disease:
– Ulcerative colitis
– Crohn’s disease
Arthritides:
– Rheumatoid arthritis
– Seronegative arthritis
Haematological disease:
– Myelocytic leukaemia[8]
– Hairy cell leukaemia
– Myelofibrosis
– Myeloid metaplasia
– Monoclonal gammopathy
Autoinflammatory disease:
– Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA syndrome)
– Granulomatosis with polyangiitis

Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003.
In general, SARS begins with a high fever (temperature greater than 38.0°C). Other symptoms may include headache, an overall feeling of discomfort, and body aches. Some people also have mild respiratory symptoms at the outset. About 10 to 20 percent of patients have diarrhoea. After 2 to 7 days, SARS patients may develop a dry cough. Most patients develop pneumonia. 

Scleroderma renal crisis (SRC) is a rare but severe complication in patients with systemic sclerosis (SSc). It is characterized by malignant hypertension, microangiopathic haemolytic anaemia with schistocytes and oligo/anuric acute renal failure. SRC occurs in 5% of patients with systemic scleroderma, particularly in the first years of disease evolution and in the diffuse form. Patients may develop symptoms of fluid overload.

Warfarin is contraindicated during pregnancy due to its teratogenic effects. She should be given heparin throughout her pregnancy. It can be converted to warfarin if necessary after the delivery.

The most probable diagnosis in this patient is conversion disorder.

There may be underlying tension regarding her musical career which could be manifesting as apparent limb weakness.

Conversion disorder typically involves loss of motor or sensory function. The patient doesn’t consciously feign the symptoms (factitious disorder) or seek material gain (malingering). Patients may be indifferent to their apparent disorder – la belle indifference – although this has not been backed up by studies.

Other options:
Unexplained symptoms
There are a wide variety of psychiatric terms for patients who have symptoms for which no organic cause can be found:

Somatization disorder
Multiple physical symptoms present for at least 2 years
the patient refuses to accept reassurance or negative test results

Hypochondriacal disorder
The persistent belief in the presence of an underlying serious disease, e.g. cancer.
The patient again refuses to accept reassurance or negative test results

Dissociative disorder
Dissociation is a process of ‘separating off’ certain memories from normal consciousness
Unlike conversion disorder, it involves psychiatric symptoms e.g. amnesia, fugue, stupor
Dissociative identity disorder (DID) is the new term for multiple personality disorder as is the most severe form of dissociative disorder

Munchausen’s syndrome
Also known as factitious disorder
The intentional production of physical or psychological symptoms

Malingering
Fraudulent simulation or exaggeration of symptoms with the intention of financial or another gain.

The most probable diagnosis in the given scenario would be Charles-Bonnet syndrome.

Charles-Bonnet syndrome (CBS) is characterized by persistent or recurrent complex hallucinations (usually visual or auditory), occurring in clear consciousness. This is generally against a background of visual impairment (although visual impairment is not mandatory for a diagnosis). Insight is usually preserved. This must occur in the absence of any other significant neuropsychiatric disturbance.

Risk factors include:
Advanced age
Peripheral visual impairment
Social isolation
Sensory deprivation
Early cognitive impairment

CBS is equally distributed between sexes and does not show any familial predisposition. The most common ophthalmological conditions associated with this syndrome are age-related macular degeneration, followed by glaucoma and cataract.

Well-formed complex visual hallucinations are thought to occur in 10-30 percent of individuals with severe visual impairment. The prevalence of CBS in visually impaired people is thought to be between 11 and 15 percent.

Urobiligen is produced by the action of bacteria on bilirubin in the intestine. As a reminder, unconjugated bilirubin becomes conjugated in the hepatocyte. Conjugated bilirubin goes through enterohepatic circulation. About half of the urobiligen is reabsorbed and excreted by the kidneys in the urine. The rest is converted to stercobilinogen –> stercobilin, which is excreted in stool, giving it its brown colour.

Brugada syndrome is an autosomal dominant disorder characterized by sudden cardiac death. The positive family history and characteristic ECG findings are in favour of Brugada syndrome. Usually the physical findings are normal.

Central retinal vein occlusion includes features such as sudden painless loss of vision, but is distinguished from central retinal artery occlusion by the presence of severe retinal haemorrhages on fundoscopy examination.

Smoking cessation is the most effective intervention in stopping the progression of COPD, as well as increasing survival and reducing morbidity. This is why smoking cessation should be the top priority in the treatment of COPD. Long term oxygen therapy (LTOT) may increase survival in hypoxic patients. The rest of the options dilate airways, reduce inflammation and thereby improve symptoms but do not necessarily increase survival.

Beef liver is one of the best sources of folic acid, amongst others like green vegetables and nuts.

From the given history the patient has NYHA grade III heart failure. He can be safely started on an ACE inhibitor as his serum potassium was towards the lower limit. As there an impairment of renal function, his urea, creatinine and serum electrolytes should be closely monitored after commencing an ACE inhibitor. Adding atenolol will not have any clinical benefit. Increasing the digoxin dose is not needed as the patient is in sinus rhythm. Increasing furosemide will only have symptomatic relief.

The correct answer is patchy inflammation. Superficial ulceration as well as non-patchy inflammation are seen in ulcerative colitis (UC) in the colon and rectum; you would expect to see transmural inflammation in Crohn’s disease and it can be patchy and located anywhere from mouth to anus. Crypt distortion and crypt abscesses are seen in both UC and Crohn’s, however they are more common in ulcerative colitis.

Activated charcoal is useful if given within one hour of the paracetamol overdose. Liver function tests, INR and prothrombin time will be normal, as liver damage may not manifest until 24 hours or more after ingestion.

The antidote of choice is intravenous N-acetylcysteine, which provides complete protection against toxicity if given within 10 hours of the overdose.

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.

Giardiasis also known as travellers diarrhoea is caused by Giardia lamblia, which is an anaerobic parasite affecting the small intestine. It can lead to diarrhoea, flatulence, abdominal cramps, malodourous greasy stools and intestinal malabsorption. It can also cause bloody diarrhoea. The investigation of choice is stool examination for trophozoites and cysts. It is treated by metronidazole and tinidazole as first line therapies.

The normal partial pressure reference values are: oxygen PaO2 more than 80 mmHg (11 kPa), and carbon dioxide PaCO2 lesser than 45 mmHg (6.0 kPa).
This patient has an elevated PaCO2 of 6.8kPa which exceeds the normal value of less than 6.0kPa.
The pH is also lower than 7.35 at 7.32

In any patient with asthma, an increasing PaCO2 indicates severe airway obstruction that is leading to respiratory muscle fatigue and patient exhaustion.

According to the British Thoracic Society guidelines:
Indications for admission to intensive care or high-dependency units include
patients requiring ventilatory support and those with acute severe or life-threatening asthma who are failing to respond to therapy, as evidenced by:
• deteriorating PEF
• persisting or worsening hypoxia
• hypercapnia
• arterial blood gas analysis showing fall in pH or rising hydrogen concentration
• exhaustion, feeble respiration
• drowsiness, confusion, altered conscious state
• respiratory arrest

Transfer to ICU accompanied by a doctor prepared to intubate if:
• Deteriorating PEF, worsening or persisting hypoxia, or hypercapnia
• Exhaustion, altered consciousness
• Poor respiratory effort or respiratory arrest

A single dose of intravenous magnesium sulphate is safe and may improve lung function and reduce intubation rates in patients with acute severe asthma. Intravenous magnesium sulphate may also reduce hospital admissions in adults with acute asthma who have had little or no response to standard treatment.

Consider giving a single dose of intravenous magnesium sulphate to
patients with acute severe asthma (PEF <50% best or predicted) who have not had a good initial response to inhaled bronchodilator therapy.
Magnesium sulphate (1.2–2 g IV infusion over 20 minutes) should only be used following consultation with senior medical staff.

Clubbing of the fingers can be present in many clinical conditions like CLD, bronchiectasis, lung abscess, Ulcerative colitis and Crohn’s Disease.

Koilonychia or spoon shaped nails are a typical finding in iron deficiency anaemia.

Splinter haemorrhages are pin point haemorrhages found in infective endocarditis and secondary to trauma.

Yellow nails are present in pulmonary and renal disease.

Warfarin inhibits the vitamin K-dependent procoagulants II, VII, IX, and X as well as anticoagulant protein C and S. It is highly protein-bound and can be displaced by a wide variety of drugs. It has a half-life of 36–48 hours.

Bleeding is the major side effect. Easy bruising, as seen in this case, is commonly seen in patients of warfarin overdose. Grossly prolonged PT and lesser increase in APTT may be seen in such cases.

Ostium secundum atrial septal defects are known to cause stroke due to the passage of emboli from the right sided circulation to the left sided circulation. ECG shows tall, peaked P waves (usually best seen in leads II and V2) and prolongation of the PR interval, rSR pattern in leads V3 R and V1 as well as right axis deviation.

The vas deferens is a long tube that connects the epididymis to the ejaculatory ducts. It acts as a canal through which mature sperm may pass through the penis during ejaculation.

Most men with CF (97-98 percent) are infertile because of a blockage or absence of the vas deferens, known as congenital bilateral absence of the vas deferens (CBAVD). The sperm never makes it into the semen, making it impossible for them to reach and fertilize an egg through intercourse. The absence of sperm in the semen can also contribute to men with CF having thinner ejaculate and lower semen volume.

Extended-spectrum beta-lactamases (ESBL) are enzymes that confer resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam. Extended spectrum beta-lactamase (ESBL) production is the main reason for multi-drug resistance among E.coli. Commonly used medications to treat ESBL-involved infections include carbapenems (imipenem, meropenem, and doripenem), cephamycins (cefoxitin and cefotetan), Fosfomycin, nitrofurantoin, beta-lactamase inhibitors (clavulanic acid, tazobactam, or sulbactam), non-beta-lactamases and colistin (if all other medications have failed.)

Prostacyclin (PGI2) generated by the vascular wall is a potent vasodilator, and the most potent endogenous inhibitor of platelet aggregation so far discovered. Prostacyclin inhibits platelet aggregation by increasing cyclic AMP levels. Prostacyclin is a circulating hormone continually released by the lungs into the arterial circulation. Circulating platelets are, therefore, subjected constantly to prostacyclin stimulation and it is via this mechanism that platelet aggregability in vivo is controlled.

Before the initiation of trastuzumab, an echocardiography is a must to rule out any pre-existing cardiac abnormalities as trastuzumab is cardiotoxic.

Trastuzumab (Herceptin) is a monoclonal antibody directed against the HER2/neu receptor. It is used mainly in metastatic breast cancer although some patients with early disease are now also given trastuzumab.

Adverse effects include:
Flu-like symptoms and diarrhoea are common.
Cardiotoxicity:
– Risk increases when anthracyclines are used concomitantly.
– Trastuzumab-induced cardiac dysfunctions are regarded as less severe and largely reversible because primary cardiomyocyte do not show ultrastructure changes unlike those associated with anthracycline-induced cardiotoxicity.
– Primary myocyte injury does not occur in patients who were treated with trastuzumab.

This describes a clinical scenario of spontaneous bacterial peritonitis. The diagnosis is made when fluid removed (ascites) is found to have > 250/mm cubed of PMNs (polymorphonuclear leukocytes). Cefotaxime or another third generation cephalosporin is the treatment of choice.

Lambert-Eaton myasthenic syndrome (LEMS) is a rare presynaptic disorder of neuromuscular transmission in which release of acetylcholine (ACh) is impaired, causing a unique set of clinical characteristics, which include proximal muscle weakness, depressed tendon reflexes, post-tetanic potentiation, and autonomic changes.

In 40% of patients with LEMS, cancer is present when the weakness begins or is found later. This is usually a small cell lung cancer (SCLC). However, LEMS has also been associated with non-SCLC, lymphosarcoma, malignant thymoma, or carcinoma of the breast, stomach, colon, prostate, bladder, kidney, or gallbladder.

This patient is having vaso-occlusive event/crisis (thrombotic crisis) which is a type of sickle cell crisis. It may be associated with ostealgia.

There is no evidence of an aplastic crisis in this case as the haemoglobin level is reasonable with a good reticulocyte count. Conversely, the haemoglobin is not low enough and reticulocyte count and bilirubin are not high enough for a haemolytic crisis.

Sickle cell anaemia is characterised by periods of good health with intervening crises. The four main types of sickle cell crises are thrombotic crisis (painful or vaso-occlusive crisis), sequestration crisis, aplastic crisis, and haemolytic crisis.

Thrombotic crisis is precipitated by infection, dehydration, alcohol, change in temperature, and deoxygenation. Sequestration crisis is characterised by acute chest syndrome (i.e. fever, dyspnoea, chest/rib pain, low pO2, and pulmonary infiltrates). Aplastic crisis is characterised by a sudden fall in haemoglobin without marked reticulocytosis. It usually occurs secondary to parvovirus infection. In haemolytic crisis, a fall in haemoglobin occurs secondary to haemolysis. It is a rare type of sickle cell crisis.