After renal transplant, asymptomatic patients can still have graft dysfunction as an early complication, with rising serum creatinine; therefore, urine and blood cultures should be ordered first. This should be followed by measuring the Tacrolimus levels, as this drug can be directly nephrotoxic. Next, a Doppler ultrasound of the transplant site should be ordered, to check for any obstructions or occlusions.

The tumour has only invaded the visceral pleura and measures 3cm in the greatest dimension. Hence it is designated at T2. Ipsilateral peribronchial and/or hilar lymph node involvement would make it N1. There is no distal metastasis so M would be 0.

Barrett’s oesophagus is the transformation of the normal squamous epithelium of the oesophagus to columnar, intestinal type epithelium. It is often seen in patients with reflux and there is a 50-100 fold increased risk of oesophageal adenocarcinoma in patients with Barrett’s oesophagus.

CADASIL is the most common form of hereditary stroke disorder. This case has a strong history of migraine with aura with stroke-like episodes, characteristic of CADASIL. Additionally, there is positive family history of migraine and early dementia but no other vascular risk factors like hypertension, diabetes, or hypercholesterolaemia, which all confirm the suspicion of CADASIL, an arteriopathy where there is thickening of the smooth muscle cells in the blood vessels.

Gaucher’s disease is characterized by hepatosplenomegaly, cytopenia, sometimes severe bone involvement and, in certain forms, neurological impairment. The variability in the clinical presentations of GD may be explained by the continuum of phenotypes. However, three major phenotypic presentations can usually be distinguished. Type-1 GD is usually named non-neuronopathic GD; type-2 and type-3 are termed neuronopathic-GD. Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages.

A history of ischaemic heart disease in a contraindication for prescribing triptans because they act by constricting cerebral and also coronary vessels, increasing the risk of stroke.

Juvenile Onset Parkinson’s is an autosomal recessive condition that usually presents in late childhood to early adulthood, initially with gait disorders caused by lower limb dystonia that later develops to the more classical signs Parkinson’s.

Normal distribution describes the spread of many biological and clinical measurements. Usually, 68.3% lies within 1 standard deviation (SD) of the mean, 95.4% lies within 2 SD of the mean and 99.7% lies within 3 SD of the mean.

Euthyroid sick syndrome (also known as nonthyroidal illness syndrome) can be described as abnormal findings on thyroid function tests that occurs in the setting of a nonthyroidal illness (NTI), without pre-existing hypothalamic-pituitary and thyroid gland dysfunction. After recovery from an NTI, these thyroid function test result abnormalities should be completely reversible.
Multiple alterations in serum thyroid function test findings have been recognized in patients with a wide variety of NTIs without evidence of pre-existing thyroid or hypothalamic-pituitary disease. The most prominent alterations are low serum triiodothyronine (T3) and elevated reverse T3 (rT3), leading to the general term low T3 syndrome. Thyroid-stimulating hormone (TSH), thyroxine (T4), free T4 (FT4), and free T4 index (FTI) also are affected in variable degrees based on the severity and duration of the NTI. As the severity of the NTI increases, both serum T3 and T4 levels drop, but they gradually normalize as the patient recovers.
Reverse T3 is used to differentiate between this condition and secondary thyroid failure.

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.

PCR is a simple, yet elegant, enzymatic assay, which allows for the amplification of a specific DNA fragment from a complex pool of DNA. PCR can be performed using source DNA from a variety of tissues and organisms, including peripheral blood, skin, hair, saliva, and microbes. Only trace amounts of DNA are needed for PCR to generate enough copies to be analysed using conventional laboratory methods. For this reason, PCR is a sensitive assay. Each PCR assay requires the presence of template DNA, primers, nucleotides, and DNA polymerase. The DNA polymerase is the key enzyme that links individual nucleotides together to form the PCR product. The above mentioned components are mixed in a test tube or 96-well plate and then placed in a machine that allows repeated cycles of DNA amplification to occur in three basic steps. The machine is essentially a thermal cycler. It has a thermal block with holes, into which the test tubes or plates holding the PCR reaction mixture are inserted. The machine raises and lowers the temperature of the block in discrete, precise and pre-programmed steps. The reaction solution is first heated above the melting point of the two complementary DNA strands of the target DNA, which allows the strands to separate, a process called denaturation. The temperature is then lowered to allow the specific primers to bind to the target DNA segments, a process known as hybridization or annealing. Annealing between primers and the target DNA occurs only if they are complementary in sequence (e.g. A binding to G). The temperature is raised again, at which time the DNA polymerase is able to extend the primers by adding nucleotides to the developing DNA strand. With each repetition of these three steps, the number of copied DNA molecules doubles.

The latest research recommends that simple tooth extraction in patients on warfarin treatment can be performed safely without high risk of bleeding, providing that the INR is equal to or less than 3.5 on the day of extraction. A close follow-up and monitoring of patients taking warfarin is mandatory after dental extraction.

Type I interferons (IFNs) form a network of homologous cytokines that bind to a shared, heterodimeric cell surface receptor and engage signalling pathways that activate innate and adaptive immune responses.

The two statements that fit the characteristics of doxapram are, epilepsy is a contraindication for doxapram use and concurrent use with theophylline may increase agitation.

Doxapram is a central respiratory stimulant. In clinical practice, doxapram is usually used for patients who have an acute exacerbation of chronic obstructive pulmonary disease (COPD) who are unsuitable for admission to the intensive therapy unit for ventilatory support. Doxapram infusion may buy an extra 24 h to allow for recovery.

Contraindications include: ischaemic heart disease, epilepsy, cerebral oedema, acute stroke, asthma, hypertension, hyperthyroidism, and pheochromocytoma.
The infusion may worsen agitation and dyspnoea and lead to hypertension, nausea, vomiting and urinary retention.

Drug interactions:
Concomitant administration of doxapram and aminophylline (theophylline) can cause increased skeletal muscle activity, agitation, and hyperactivity.

The patient most likely has reactive arthritis which is usually diagnosed on history and clinical examination. The classic triad of symptoms include conjunctivitis, urethritis and arthritis. Arthritis and conjunctivitis may occur 4-6 weeks after a gastrointestinal or genitourinary infection. Arthritis usually occurs acutely, mostly involving the lower limb and is asymmetrical. Blood culture, urine culture and arthrocentesis (joint aspiration) will not yield positive results.

Positive predictive value is the probability that subjects with a positive screening test truly have the disease.

Positive predictive value = true positive / ( true positive + false positive)

The patient has presented with signs of small cell lung cancer. The associated proximal muscle weakness is most probably due to dermatomyositis which occurs as a paraneoplastic syndrome associated with lung carcinoma. In most cases, the first symptom is a distinctive skin rash on the face, eyelids, chest, nail cuticle areas, knuckles, knees or elbows. The rash is patchy and usually a bluish-purple colour. Corticosteroids are helpful in the management of the cutaneous changes and muscle weakness.

All of the aforementioned listed tumours, except brain tumours, can metastasise to lungs and produce the typical CXR picture consisting of hilar lymphadenopathy with either diffuse multinodular shadows resembling miliary disease or multiple large well-defined masses (canon balls). Occasionally, cavitation or calcification may also be seen.

Most brain tumours, however, do not metastasise. Some, derived form neural elements, do so but in these cases, intraparenchymal metastases generally precede distant haematogenous spread.

Post-concussion syndrome is a complex disorder in which various symptoms, such as headaches and dizziness, last for weeks and sometimes months after the injury that caused the concussion.

Concussion is a mild traumatic brain injury that usually happens after a blow to the head. It can also occur with violent shaking and movement of the head or body. You don’t have to lose consciousness to get a concussion or post-concussion syndrome. In fact, the risk of post-concussion syndrome doesn’t appear to be associated with the severity of the initial injury.

Post-concussion symptoms include:
Headaches
Dizziness
Fatigue
Irritability
Anxiety
Insomnia
Loss of concentration and memory
Ringing in the ears
Blurry vision
Noise and light sensitivity
Rarely, decreases in taste and smell

The principal mechanism by which strontium inhibits osteoclast activity is by enhancing the secretion of osteoprotegerin (OPG) and by reducing the expression of the receptor activator of nuclear factor κB ligand (RANKL) in osteoblasts.

Osteoporosis is defined as low bone mineral density caused by altered bone microstructure ultimately predisposing patients to low-impact, fragility fractures.

Management:
Vitamin D and calcium supplementation should be offered to all women unless the clinician is confident they have adequate calcium intake and are vitamin D replete
Alendronate is the first-line treatment. Around 25% of patients cannot tolerate alendronate, usually due to upper gastrointestinal problems. These patients should be offered risedronate or etidronate.
Strontium ranelate and raloxifene are recommended if patients cannot tolerate bisphosphonates.
Other medications that are useful in the treatment of osteoporosis are denosumab, teriparatide, raloxifene, etc.

An atheroma is an accumulation of degenerative material in the tunica intima (inner layer) of artery walls. The material consists of (mostly) macrophage cells, or debris, containing lipids (cholesterol and fatty acids), calcium and a variable amount of fibrous connective tissue.

IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect nearly any organ system: the pancreas, biliary tree, salivary glands, periorbital tissues, kidneys, lungs, lymph nodes, meninges, aorta, breast, prostate, thyroid, pericardium, and skin. The histopathological features are similar across organs, regardless of the site. IgG4-RD is analogous to sarcoidosis, in which diverse organ manifestations are linked by similar histopathological characteristics. Raised concentrations of IgG4 in tissue and serum can be helpful in diagnosing IgG4 disease, but neither is a specific diagnostic marker.

Some IgG4-RDs are:
1. Autoimmune pancreatitis
2. Riedel’s Thyroiditis
3. Mediastinal and Retroperitoneal Fibrosis
4. Periaortitis/periarteritis/Inflammatory aortic aneurysm
5. Kuttner Tumour (submandibular glands)
6. IgG4-related Mikulicz disease (lacrimal, parotid, and submandibular glands)

Gamma delta T cells are of low abundance in the body, are found in the gut mucosa, skin, lungs and uterus, and are involved in the initiation and propagation of immune responses. Their ligands are not known in detail, but the gamma delta T cell receptors recognise intact proteins rather than MHC-presented peptides. Like alpha beta T cells, they develop in the thymus.

Hypocalcaemia occurs in patients with impaired function of the parathyroid glands. This is most common after thyroid or parathyroid surgery, but it can be idiopathic—mostly in young adults and less often as part of a genetic syndrome, such as autoimmune polyglandular syndrome type 1. Usually, the first and most useful test to perform in such cases is the measurement of the parathyroid hormone.

Pulsus paradoxus is defined as the exaggerated fall in systolic blood pressure during inspiration by greater than 10 mmHg. Cardiac tamponade is the classic cause of pulsus paradoxus. Kussmaul’s sign (a rise in the jugular venous pressure on inspiration) is mostly seen in constrictive pericarditis. Hypotension, muffled heart sounds and raised JVP can be seen in both conditions.

Generally, underlying causes of confusion need to be looked for and treated as appropriate, for example, hypercalcaemia, infection, urinary retention, and medication. If specific treatments fail, the following may be tried:

1. First choice: haloperidol
2. Other options: chlorpromazine, levomepromazine

In the terminal phase of the illness, agitation or restlessness is best treated with midazolam.

Insulin is produced by the beta-cells in the islets of Langerhans in the pancreas while Glucagon is secreted from the alpha cells of the pancreatic islets of Langerhans.
Type 1 diabetes mellitus is the culmination of lymphocytic infiltration and destruction of the beta cells of the islets of Langerhans in the pancreas. As beta-cell mass declines, insulin secretion decreases until the available insulin is no longer adequate to maintain normal blood glucose levels. After 80-90% of the beta cells are destroyed, hyperglycaemia develops and diabetes may be diagnosed.

Methyldopa is the drug of first choice for the control of mild to moderate hypertension in pregnancy. Labetalol is also considered as a first line drug for hypertension in pregnancy. Calcium channel blockers and hydralazine are considered as second line drugs. Beta-blockers (except labetalol), angiotensin receptor blockers, angiotensin-converting enzyme inhibitors and thiazides are not recommended.

Hypertrophic cardiomyopathy is an autosomal dominant condition. Patients present with sudden cardiac death, dyspnoea, syncope and presyncope, angina, palpitations, orthopnoea and paroxysmal nocturnal dyspnoea, Congestive heart failure and dizziness. Physical findings include double or triple apical impulse, prominent a wave in the JVP, an ejection systolic crescendo-decrescendo murmur and a holosystolic murmur at the apex and axilla of mitral regurgitation.
ECG shows ST-T wave abnormalities and LVH, axis deviation (right or left), conduction abnormalities (P-R prolongation, bundle-branch block), sinus bradycardia with ectopic atrial rhythm, atrial enlargement, abnormal and prominent Q wave in the anterior precordial and lateral limb leads.
2D echocardiography shows abnormal systolic anterior leaflet motion of the mitral valve, LVH, left atrial enlargement, small ventricular chamber size, septal hypertrophy with septal-to-free wall ratio greater than 1.4:1, mitral valve prolapse and mitral regurgitation, decreased midaortic flow, partial systolic closure of the aortic valve in midsystole

Mitochondrial DNA (mtDNA) is a double-stranded molecule of 16.6 kb (Figure 1, lower panel). The two strands of mtDNA differ in their base composition, with one being rich in guanines, making it possible to separate a heavy (H) and a light (L) strand by density centrifugation in alkaline CsCl2 gradients.