Intestinal phosphate absorption is mediated by both transcellular and paracellular routes. The 1,25(OH)2D increases intestinal transcellular phosphate absorption at least in part by enhancing expression of type 2b sodium–phosphate cotransporter, thus increasing plasma phosphate.

The antithrombotic action of aspirin is due to inhibition of platelet function by acetylation of the platelet cyclooxygenase (COX) at the functionally important amino acid serine529. This prevents the access of the substrate (arachidonic aid) to the catalytic site of the enzyme at tyrosine385 and results in an irreversible inhibition of platelet-dependent thromboxane formation.

Carboxylation of factor II, VII, IX, X and protein C is affected by warfarin. Factor XII is not affected.

Agitation, hypomania and suicidal intent within a few days after initiating corticosteroid therapy is highly suggestive of a diagnosis of corticosteroid-induced psychosis.

In some patients corticosteroid related psychosis has been diagnosed up to 12 weeks or more after commencing therapy.

Euphoria and hypomania are considered to be the most common psychiatric symptoms reported during short courses of steroids.
During long-term treatment, depressive symptoms were the most common.
Higher steroid doses appear to carry an increased risk for such adverse effects; however, there is no significant relationship between dose and time to onset, duration, and severity of symptoms.

Management: Reduction or cessation of corticosteroids is the mainstay of treatment for steroid psychosis. For those patients who cannot tolerate this reduction/cessation of steroids, mood stabilizers may be of some benefit.

A patient with a gradual onset of schizophrenia is to be associated with a poor prognosis.

Schizophrenia is a functional psychotic disorder characterized by the presence of delusional beliefs, hallucinations, and disturbances in thought, perception, and behaviour.

Clinical features:
Schneider’s first-rank symptoms may be divided into auditory hallucinations, thought disorders, passivity phenomena, and delusional perceptions:

Auditory hallucinations of a specific type:
Two or more voices discussing the patient in the third person
Thought echo
Voices commenting on the patient’s behaviour

Thought disorder:
Thought insertion
Thought withdrawal
Thought broadcasting

Passivity phenomena:
Bodily sensations being controlled by external influence
Actions/impulses/feelings – experiences which are imposed on the Individual or influenced by others

Other features of schizophrenia include
Impaired insight (a feature of all psychoses)
Incongruity/blunting of affect (inappropriate emotion for circumstances)
Decreased speech
Neologisms: made-up words
Catatonia
Negative symptoms: incongruity/blunting of affect, anhedonia (inability to derive pleasure), alogia (poverty of speech), avolition (poor motivation).

Treatment:
For the initial treatment of acute psychosis, it is recommended to commence an oral second-generation antipsychotics such as aripiprazole, olanzapine, risperidone, quetiapine, etc.
Once the acute phase is controlled, switching to a depot preparation like aripiprazole, paliperidone, zuclopenthixol, fluphenazine, haloperidol, pipotiazine, or risperidone is recommended.
Cognitive-behavioural therapy (CBT) and the use of art and drama therapies help counteract the negative symptoms of the disease, improve insight, and assist relapse prevention.
Clozapine is used in case of treatment resistance.

The a wave indicates atrial contraction. The c wave indicates ventricular contraction and resulting bulging of the tricuspid valve into the right atrium during isovolumetric systole. The v wave indicates venous filling. The x descent indicates the atrium relaxation and the movement of tricuspid valve downward. The y descent indicates the filling of the ventricle after the opening of the tricuspid valve.

Infection of chickenpox in the first half of pregnancy can result in congenital varicella syndrome. It presents as cerebral, cortical and cerebellar hypoplasia with convulsions and rudimentary digits. Prevention is by administering varicella vaccine, even before pregnancy. Varicella immunoglobulin is administered to pregnant women who are exposed to infection. Infection during pregnancy is treated with acyclovir.

Absolute risk reduction (ARR) – also called risk difference (RD) – is the most useful way of presenting research results to help your decision-making. Absolute risk reduction = (Control event rate) – (Experimental event rate) = 0.15 = 15%

Cystic fibrosis (CF) is a multisystemic, autosomal recessive disorder that predominantly affects infants, children, and young adults. CF is the most common life-limiting genetic disorder in whites, with an incidence of 1 case per 3200-3300 new-borns in the United States.

People with CF can have a variety of symptoms, including:
Very salty-tasting skin
Persistent coughing, at times with phlegm
Frequent lung infections including pneumonia or bronchitis
Wheezing or shortness of breath
Poor growth or weight gain in spite of a good appetite
Frequent greasy, bulky stools or difficulty with bowel movements
Male infertility

Signs of bronchiectasis include the tubular shadows; tram tracks, or horizontally oriented bronchi; and the signet-ring sign, which is a vertically oriented bronchus with a luminal airway diameter that is 1.5 times the diameter of the adjacent pulmonary arterial branch.

Bronchiectasis is characterized by parallel, thick, line markings radiating from hila (line tracks) in cylindrical bronchiectasis. Ring shadows represent dilated thick-wall bronchi seen in longitudinal section or on-end or dilated bronchi in varicose bronchiectasis.

Pseudomonas aeruginosa is the key bacterial agent of cystic fibrosis (CF) lung infections, and the most important pathogen in progressive and severe CF lung disease. This opportunistic pathogen can grow and proliferate in patients, and exposure can occur in hospitals and other healthcare settings.

Haemophilus influenzae is regularly involved in chronic lung infections and acute exacerbations of CF patients

The given clinical scenario is suggestive of myo-neuropathy and is most likely to be caused by colchicine toxicity.
It gives rise to subacute proximal muscle weakness and on occasions can lead to an acute necrotizing myopathy. Creatine phosphokinase may be normal or may be elevated.
Weakness resolves when the drug is discontinued but the neuropathic features remain.
Death is usually a result of respiratory depression and cardiovascular collapse.
Treatment is symptomatic and supportive, and the treatment for colchicine poisoning includes lavage and measures to prevent shock.

The oxygen saturation in the pulmonary artery is higher than that of the right ventricle. The pressure of the pulmonary artery and of the PCWP are also high. So patent ductus arteriosus is highly suggestive.

The somatotroph cells of the anterior pituitary gland produce growth hormone (GH).
GH deficiency in adults usually manifests as reduced physical performance and impaired psychological well-being. It results in alterations in the physiology of different systems of the body, manifesting as altered lipid metabolism, increased subcutaneous and visceral fat, decreased muscle mass, decreased bone density, low exercise performance, and reduced quality of life.

The most probable diagnosis of this patient is Cotard syndrome with major depressive disorder.

Cotard syndrome is a rare mental disorder where the affected patient believes that they (or in some cases just a part of their body) is either dead or non-existent. This delusion is often difficult to treat and can result in significant problems due to patients stopping eating or drinking as they deem it not necessary. Cotard syndrome is often associated with severe depression and psychotic disorders (like schizophrenia).

Other delusional syndromes:
– Othello syndrome is a delusional belief that a patients partner is committing infidelity despite no evidence of this. It can often result in violence and controlling behaviour.
– De Clerambault syndrome (otherwise known as erotomania), is where a patient believes that a person of higher social or professional standing is in love with them. Often this presents with people who believe celebrities are in love with them.
– Capgras syndrome is characterised by a person believing their friend or relative had been replaced by an exact double.
– Couvade syndrome is also known as ‘sympathetic pregnancy’. It affects fathers, particularly during the first and third trimesters of pregnancy, who suffer the somatic features of pregnancy.
– Ekbom syndrome is also known as delusional parasitosis and is the belief that they are infected with parasites or have ‘bugs’ under their skin. This can vary from the classic psychosis symptoms in narcotic use where the user can ‘see’ bugs crawling under their skin or can be a patient who believes that they are infested with snakes.

Whilst asthma and COPD are different diseases they cause similar symptoms, which can present a challenge in identifying which of the two diseases a patient is suffering from. COPD causes chronic symptoms and narrowed airways which do not respond to treatment to open them up. In the case of asthma the constriction of the airways through inflammation tends to come and go and treatment to reduce inflammation and to open up the airways usually works well.

COPD is more likely than asthma to cause a chronic cough with phlegm and is rare before the age of 35 whilst asthma is common in under-35s. Disturbed sleep caused by breathlessness and wheeze is more likely in cases of asthma, as is a history of allergies, eczema and hay fever. Differentiating between COPD and asthma requires a history of both symptoms and spirometry. The spirometry history should include post bronchodilator measurements, the degree of reversibility and, ideally, home monitoring which gives a history of diurnal variation.

Airflow Obstruction: Both asthma and COPD are characterised by airflow obstruction. Airflow obstruction is defined as a reduced FEV1 and a reduced FEV1/FVC ratio, such that FEV1 is less than 80% of that predicted, and FEV1/FVC is less than 0.7.

These episodes are usually associated with widespread, but variable, airflow obstruction within the lung that is often reversible either spontaneously or with treatment.

COPD: COPD is a chronic, slowly progressive disorder characterised by airflow obstruction (reduced FEV1 and FEV1/VC ratio) that does not change markedly over several months. The airflow obstruction is not fully reversible.

Spirometry COPD Asthma
VC Reduced Nearly normal
FEV1 Reduced Reduced in attack
FVC (or FEV6) Reduced Nearly normal
FEV1 Ratio
(of VC/FVC/FEV6) Reduced in attack

This man has a low FEV1 and FVC. His diffusions capacity is also low despite having a normal total lung capacity. These values confirm a diagnosis of COPD.

This patient has Wilson’s disease. They Kayser-Fleischer ring (ring that encircles the iris) is diagnostic of this. Low serum copper is seen in Wilson’s disease. With the Kayser-Fleischer ring, this makes all of the other answer choices incorrect.

Features that affect prognosis are tumour thickness in millimetres (Breslow’s depth – the deeper the Breslow thickness the poorer the prognosis.), depth related to skin structures (Clark level – the level of invasion through the dermis), type of melanoma, presence of ulceration, presence of lymphatic/perineural invasion, presence of tumour-infiltrating lymphocytes (if present, prognosis is better), location of lesion, presence of satellite lesions, and presence of regional or distant metastasis. Malignant melanoma tends to grow radially before entering a vertical growth phase. The diameter it reaches has not been found to be a prognostic factor.

Age-related macular degeneration is the most common cause of blindness in the UK. Degeneration of the central retina (macula) is the key feature with changes usually bilateral. Smoking and genetic factors are risk factors for macular degeneration. The severity is divided into early, intermediate, and late types. The late type is additionally divided into dry and wet forms with the dry form making up 90% of cases.

History of recurrent infections and failure to thrive (probably due to pancreatic enzyme insufficiency) is highly suggestive of cystic fibrosis. Pseudomonas has been identified as an important respiratory pathogen in patients with cystic fibrosis.

Syringomyelia is a development of a cavity (syrinx) within the spinal cord. Signs and symptoms include loss of feeling, paralysis, weakness, and stiffness in the back, shoulders, and extremities. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. Symptoms typically vary depending on the extent and, often more critically, on the location of the syrinx within the spinal cord.

Acute cord compression is a medical emergency. Typically, signs of segmental damage at the level of compression are usually combined with corticospinal tract dysfunction (e.g., hyperreflexia, Babinski’s sign and weakness) and sensory deficits below the level of compression. Symptoms include spinal pain that precedes the development of weak legs and sensory loss. There may be loss of bladder (and anal) sphincter control, manifesting as hesitancy, frequency and, finally, painless retention.
Spinal X-rays are rarely diagnostic. MRI is usually the investigation of choice and should not be delayed, but if not available consider doing a CT scan and myelography to confirm cord compression and fully define the level and extent of the lesion. If malignancy is the cause, it is important to give dexamethasone (oral or intravenous) while considering therapy more specific to the cause.

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 is a classic clinical presentation, with alcohol intake and nausea/vomiting that leads to hematemesis, of a Mallory-Weiss tear. Because of the history, that makes this more likely than haemorrhagic gastritis, duodenal ulceration, or oesophagitis (also oesophagitis would not bleed a cupful). Oesophageal varices would present with copious amounts of hematemesis and most likely hemodynamic instability as a result of the amount of blood loss. In Mallory-Weiss tear they are typically presented as a hemodynamically stable patient.

Hypopyon can be seen in anterior uveitis, however the combination of a normal pupillary reaction and contact lens use make a diagnosis of keratitis more likely. Keratitis describes inflammation of the cornea, and features include red eye with pain and erythema, photophobia, and foreign body/gritty sensation.

Exposure to aniline dyes is a risk factor for transitional cell carcinoma. Aniline dyes are used in dyestuffs and pigment manufacturing.

The other aforementioned options are ruled out because:
1. Feed production may expose to aflatoxin (hepatocellular carcinoma).

2. Being a military personnel may expose to mustard gas (lung cancer).

3. Rubber industry may expose to nitrosamines (oesophageal and gastric cancer).

4. Refrigerant production before 1974 may expose to vinyl chloride (hepatic angiosarcoma).

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.

The C8 nerve forms part of the radial and ulnar nerves via the brachial plexus, and therefore has motor and sensory function in the upper limb. It originates from the spinal column from below the cervical vertebra 7 (C7).
The C8 nerve receives sensory afferents from the C8 dermatome. This consists of all the skin on the little finger, and continuing up slightly past the wrist on the palmar and dorsal aspects of the hand and forearm.
The other options available correspond to the C6 or C7 roots and these are unaffected as evidenced by normal elbow flexion and thumb sensation (C6) and normal sensation over the middle finger (C7). Elbow extension is weak as it has roots from both C7 and C8 and so cannot be used alone to decide between the two levels clinically.
The C8 nerve contributes to the motor innervation of many of the muscles in the trunk and upper limb. Its primary function is the flexion of the fingers, and this is used as the clinical test for C8 integrity, in conjunction with the finger jerk reflex.

Trunk:
– Pectoralis major – Medial and lateral pectoral nerves (C5, C6, C7, C8, T1)
– Pectoralis minor – Medial pectoral nerve (C5, C6, C7,C8, T1)
– Latissimus dorsi – Thoracodorsal nerve (C6, C7, C8)
Upper arm:
– Triceps brachii – Radial nerve (C6, C7,C8)
Forearm
– Flexor carpi ulnaris – Ulnar nerve (C7, C8, T1)
– Palmaris longus – Median nerve (C7,C8)
– Flexor digitorum superficialis – Median nerve (C8, T1)
– Flexor digitorum profundus – Median and Ulnar nerves (C8, T1)
– Flexor pollicis longus – Median nerve (C7,C8)
– Pronator quadratus – Median nerve (C7,C8)
– Extensor carpi radialis brevis – Deep branch of the radial nerve (C7,C8)
– Extensor digitorum – Posterior interosseous nerve (C7,C8)
– Extensor digiti minimi – Posterior interosseous nerve (C7,C8)
– Extensor carpi ulnaris – Posterior interosseous nerve (C7,C8)
– Anconeus – Radial nerve (C6, C7,C8)
– Abductor pollicis longus – Posterior interosseous nerve (C7,C8)
– Extensor pollicis brevis – Posterior interosseous nerve (C7,C8)
– Extensor pollicis longus – Posterior interosseous nerve (C7,C8)
– Extensor indicis – Posterior interosseous nerve (C7,C8)
Hand
– Palmaris brevis – Superficial branch of ulnar nerve (C8, T1)
– Dorsal interossei – Deep branch of ulnar nerve (C8, T1)
– Palmar interossei – Deep branch of ulnar nerve (C8, T1)
– Adductor pollicis – Deep branch of ulnar nerve (C8, T1)
– Lumbricals – Deep branch of ulnar, Digital branches of median nerve
– Opponens pollicis – Recurrent branch of median nerve (C8, T1)
– Abductor pollicis brevis – Recurrent branch of median nerve (C8, T1)
– Flexor pollicis brevis – Recurrent branch of median nerve (C8, T1)
– Opponens digiti minimi – Deep branch of ulnar nerve (C8, T1)
– Abductor digiti minimi – Deep branch of ulnar nerve (C8, T1)
– Flexor digiti minimi brevis – Deep branch of ulnar nerve (C8, T1)

Cystinuria is strongly suspected because of the recurrent passing of cystine stones and otherwise non-remarkable medical history of this young adult patient. Like Cystinuria, all the conditions listed are also inherited disorders, however, the other differentials usually present in the early years of childhood, usually with failure to thrive.

As the patient has early menopause, hormone replacement therapy (HT) is considered to be the first line of choice for prevention of bone loss and fracture in the early postmenopausal period for 5 years.

It is proven that spironolactone has survival benefits and loop diuretics only give symptomatic relief. Beta blockers are however, known to improve exercise tolerance, left ventricular function and reduce symptoms. They also reduce the mortality associated with heart failure. So administration of beta blockers will reduce the time spent in hospital by improving symptoms.

Diseases that cause predominantly sensory loss include diabetes, uraemia, leprosy, alcoholism, vitamin B12 deficiency, and amyloidosis.
Those that cause predominantly motor loss include Guillain-Barre syndrome, porphyria, lead poisoning, hereditary sensorimotor neuropathies, chronic inflammatory demyelinating polyneuropathy, and diphtheria.