NICE guidelines on hypercalcemia recommend that maintaining good hydration equals drinking 3-4 L of fluid/day, provided there are no contraindications. A low calcium diet is not necessary because intestinal absorption of calcium is reduced. The patient should avoid any other drugs or vitamins that could worsen the hypercalcemia. Mobilization is encouraged and any symptoms of hypercalcemia should be reported.

The Hyperlipidaemia Effect: Pseudohyponatremia in Pancreatic Cancer; Patients who have disorders of cholestasis commonly present with volume depletion due to vomiting and poor oral intake, which, in turn, often leads to hypovolemic hyponatremia. It is less well known that disorders of cholestasis, including tumours of the hepatobiliary system, can be accompanied by hyperlipidaemia.

Lysosomal hydrolases are synthesized in the rough endoplasmic reticulum and specifically transported through the Golgi apparatus to the trans-Golgi network, from which transport vesicles bud to deliver them to the endosomal/lysosomal compartment. The explanation of how the lysosomal enzymes are accurately recognized and selected over many other proteins in the trans-Golgi network relies on them being tagged with a unique marker: the mannose-6-phosphate (M6P) group, which is added exclusively to the N-linked oligosaccharides of lysosomal soluble hydrolases, as they pass through the cis-Golgi network. Generation of the M6P recognition marker depends on a reaction involving two different enzymes: UDP-N-acetylglucosamine 1-phosphotransferase and α-N-acetylglucosamine-1-phosphodiester α-N-acetylglucosaminidase.

The number needed to treat (NNT) is valuable information in treatment decisions. NNT is the inverse of the absolute risk reduction (1/ARR) between two treatment options.

Molluscum contagiosum (MC), is a viral infection of the skin that results in small, raised, pink lesions with a dimple in the center with little to no surrounding erythema. They may occasionally be itchy or sore. They may occur singularly or in groups. Any area of the skin may be affected, with abdomen, legs, arms, neck, genital area, and face being most common. Onset of the lesions is around 7 weeks after infection. It usually goes away within a year without scarring.
Chickenpox lesions in the early stages may be mistaken for molluscum. However, the presence of associated macules and later vesicles and pustules help to differentiate them.

Hypovitaminosis B1, consistent with dry beriberi is crucially a treatable condition, although sometimes with incomplete recovery, but it is probably under-recognized yet increasingly common given increasing levels of alcohol abuse in the western world. Dry beriberi or ‘acute nutritional polyneuropathy’ is considered to be rare in the western world. Rapid deterioration can occur, typically with weakness, paraesthesia and neuropathic pain. Striking motor nerve involvement can occur, mimicking Guillain-Barré syndrome (GBS). In the context of increasing alcohol abuse in the western world, it is possible that alcoholic neuropathy associated with abrupt deterioration due to concomitant nutritional hypovitaminosis B1 may be seen increasingly often.

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

This woman is receiving methotrexate, an immunosuppressant, to control her rheumatoid arthritis. In such immunocompromised patients, BNF suggests clarithromycin as first-line management.

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.

Depending on the level of SCI, patients experience paraplegia or tetraplegia. Paraplegia is defined as the impairment of sensory or motor function in lower extremities. Patients with incomplete paraplegia generally have a good prognosis in regaining locomotor ability (,76% of patients) within a year. Complete paraplegic patients, however, experience limited recovery of lower limb function if their NLI is above T9. The spinothalamic tract is the one responsible for sensory information such as pain or temperature. However, it decussates at the same level the nerve root enters the spinal cord, meaning that the sensory loss will be contralateral. However, the dorsal column carries sensory fibres for fine touch and vibration and it decussates at the medulla which means that the sensory loss will be ipsilateral. The corticospinal tract is responsible for motor functions and it decussates at the medulla, meaning that the motor function loss will be ipsilateral.

Dermatitis herpetiformis (DH), or Duhring’s disease, is a chronic blistering skin condition,characterised by blisters filled with a watery fluid. Despite its name, it is neither related to nor caused by herpes virus: the name means that it is a skin inflammation having an appearance similar to herpes.
Dermatitis herpetiformis is characterized by intensely itchy, chronic papulovesicular eruptions, usually distributed symmetrically on extensor surfaces (buttocks, back of neck, scalp, elbows, knees, back, hairline, groin, or face)
Dermatitis herpetiformis is an autoimmune condition associated with HLA-DR3.
HLA-A3 is associated with haemochromatosis. HLA-B5 is most commonly associated with Behcet’s disease. HLA-DR4 is associated with both type 1 diabetes mellitus and rheumatoid arthritis. HLA-B27 is most commonly associated with several diseases, most commonly ankylosing spondylitis.

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.

Relative risk reduction (RRR) tells you by how much the treatment reduced the risk of bad outcomes relative to the control group who did not have the treatment. In the previous example, the relative risk reduction of fever and rash in the group of the children on the intervention was 40 per cent (1 – 0.6 = 0.4 or 40 per cent). RRR = (EER -CER) / CER = (0.1 – 0.4) / 0.4 = -0.75 or 75% reduction.

L4 dermatome distribution includes the kneecaps.

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.

Polymerase chain reaction (PCR) is a method widely used in molecular biology to make several copies of a specific DNA segment. Using PCR, copies of DNA sequences are exponentially amplified to generate thousands to millions of more copies of that particular DNA segment.The main advantage of PCR is its sensitivity: only one strand of sample DNA is needed to detect a particular DNA sequence. It now has many uses including prenatal diagnosis, detection of mutated oncogenes and diagnosis of infections. PCR is also extensively used in forensics.

Achondroplasia is a common cause of dwarfism. It is caused by a mutation in fibroblast growth factor receptor 3 (FGFR3). In normal development FGFR3 has a negative regulatory effect on bone growth. In achondroplasia, the mutated form of the receptor is constitutively active and this leads to severely shortened bones. The effect is genetically dominant, with one mutant copy of the FGFR3 gene being sufficient to cause achondroplasia, while two copies of the mutant gene are invariably fatal. A person with achondroplasia thus has a 50% chance of passing dwarfism to each of their offspring. People with achondroplasia can be born to parents that do not have the condition due to spontaneous mutation. It occurs as a sporadic mutation in approximately 80% of cases (associated with advanced paternal age) or it may be inherited as an autosomal dominant genetic disorder.
People with achondroplasia have short stature, with an average adult height of 131 centimeters (52 inches) for males and 123 centimeters (48 inches) for females.

Reverse transcription polymerase chain reaction is a laboratory technique combining reverse transcription of RNA into DNA and amplification of specific DNA targets using polymerase chain reaction. It is primarily used to measure the amount of a specific RNA. The main advantage of PCR is its sensitivity: only one strand of sample DNA is needed to detect a particular DNA sequence. It now has many uses including prenatal diagnosis, detection of mutated oncogenes and diagnosis of infections.

Nerve conduction velocity is an important aspect of nerve conduction studies. It is the speed at which an electrochemical impulse propagates down a neural pathway. Ultimately, conduction velocities are specific to each individual and depend largely on an axon’s diameter and the degree to which that axon is myelinated.
The cardiac action potential is a brief change in voltage (membrane potential) across the cell membrane of heart cells. Conduction speed varies:
Atrial conduction spreads along ordinary atrial myocardial fibres at 1 m/sec
AV node conduction 0.05 m/sec
Ventricular conduction Purkinje fibres are of large diameter and achieve velocities of 2-4 m/sec (this allows a rapid and coordinated contraction of the ventricles.

A case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the cases) with patients who do not have the condition/disease but are otherwise similar (the controls).
An odds ratio (OR) is a statistic that quantifies the strength of the association between two events, A and B. The odds ratio is defined as the ratio of the odds of A in the presence of B and the odds of A in the absence of B or vice versa.

Funnel plots are graphical tools to assess and compare clinical performance of a group of care professionals or care institutions on a quality indicator against a benchmark. Incorrect construction of funnel plots may lead to erroneous assessment and incorrect decisions potentially with severe consequences.

Riboflavin, vitamin B2, is a water-soluble and heat-stable vitamin that the body uses to metabolize fats, protein, and carbohydrates into glucose for energy. Riboflavin deficiency can cause fatigue, swollen throat, blurred vision, and depression. It can affect the skin by causing skin cracks, itching, and dermatitis around the mouth. Hyperaemia and oedema around throat, liver degeneration, and hair loss can also occur along with reproductive issues. Usually, people with riboflavin deficiency also have deficiencies of other nutrients. In most cases, riboflavin deficiency can be reversed unless it has caused anatomical changes such as cataracts.

Supravalvular aortic stenosis, is associated with a condition called William’s syndrome.
William’s syndrome is an inherited neurodevelopmental disorder caused by a microdeletion on chromosome 7. The most common symptoms of Williams syndrome are heart defects and unusual facial features. Other symptoms include failure to gain weight appropriately in infancy (failure to thrive) and low muscle tone. Individuals with Williams syndrome tend to have widely spaced teeth, a long philtrum, and a flattened nasal bridge.
Most individuals with Williams syndrome are highly verbal relative to their IQ, and are overly sociable, having what has been described as a cocktail party type personality.

Acute, symptomatic hypocalcaemia is treated with 10ml of 10% calcium gluconate over 10 minutes.

The Smooth endoplasmic reticulum (ER) is the major site at which membrane lipids are synthesized in eukaryotic cells. Because they are extremely hydrophobic, lipids are synthesized in association with already existing cellular membranes rather than in the aqueous environment of the cytosol. Although some lipids are synthesized in association with other membranes, most are synthesized in the ER. They are then transported from the ER to their ultimate destinations either in vesicles or by carrier proteins.

Interleukin-4 (IL-4), IL-5 and IL-13, the signature cytokines that are produced during type 2 immune responses, are critical for protective immunity against infections of extracellular parasites and are responsible for asthma and many other allergic inflammatory diseases. Although many immune cell types within the myeloid lineage compartment including basophils, eosinophils and mast cells are capable of producing at least one of these cytokines, the production of these “type 2 immune response-related” cytokines by lymphoid lineages, CD4 T helper 2 (Th2) cells and type 2 innate lymphoid cells (ILC2s) in particular, are the central events during type 2 immune responses.

Meningiomas are the most common benign tumours of the brain. Their name is derived from the fact that they arise from the dura mater which together with the pia matter and arachnoid mater form the meninges. The chances that a meningioma is benign are almost 98%. They are non-invasive and well delineated, causing sign and symptoms of brain compression.

Relative Risk = (Probability of event in exposed group) / (Probability of event in not exposed group)
Experimental event rate, EER = 10 / 200 = 0.05

Control event rate, CER = 12 / 600 = 0.02

Therefore the relative risk = EER / CER = 0.05 / 0.02 = 2.5

Nitric oxide, known as an endothelium-derived relaxing factor (EDRF), is biosynthesized endogenously from L-arginine, oxygen, and NADPH by various nitric oxide synthase (NOS) enzymes and is a signaling molecule in many physiological and pathological processes in humans.
One of the main enzymatic targets of nitric oxide is guanylyl cyclase. The binding of nitric oxide to the haem region of the enzyme leads to activation, in the presence of iron.

Over consumption of fluids, prolonged race duration and inadequate training all can predispose to acute hyponatraemia.
Mild symptoms include a decreased ability to think, headaches, nausea, and an increased risk of falls. Severe symptoms include confusion, seizures, and coma. Normal serum sodium levels are 135 – 145 mEq/liter (135 – 145 mmol/L). Hyponatremia is generally defined as a serum sodium level of less than 135 mEq/L and is considered severe when the level is below 120 mEq/L.
The correct treatment to give is hypertonic saline. Decompressive craniotomy would help alleviate raised intracranial pressure due to cerebral oedema however is not an appropriate first line treatment. Demeclocycline is used for SIADH and mannitol is more likely to be used in the context of traumatic brain injury.
Hyponatremia is corrected slowly, to lessen the risk of the development of central pontine myelinolysis (CPM), a severe neurological disease involving a breakdown of the myelin sheaths covering parts of nerve cells. During treatment of hyponatremia, the serum sodium (salt level in the blood) should not rise by more than 8 mmol/L over 24 hours.