Northern blotting’s purpose is to measure the size and amount of RNA transcribed from a specific gene of interest.

The patient likely has celiac’s disease, but if she has been avoiding gluten, a biopsy may be negative. Even though a biopsy is the gold standard for diagnosis, she will need to re-introduce gluten into her diet prior to undergoing the biopsy.

Osteoarthritis (OA) is a disabling joint disease characterized by a noninflammatory degeneration of the joint complex (articular cartilage, subchondral bone, and synovium) that occurs with old age or from overuse. It mainly affects the weight-bearing and high-use joints, such as the hip, knee, hands, and vertebrae. Despite the widespread view that OA is a condition caused exclusively by degenerative “wear and tear” of the joints, newer research indicates a significant heterogeneity of causation, including pre-existing peculiarities of joint anatomy, genetics, local inflammation, mechanical forces, and biochemical processes that are affected by proinflammatory mediators and proteases. Major risk factors include advanced age, obesity, previous injuries, and asymmetrically stressed joints. In early-stage osteoarthritis, patients may complain of reduced range of motion, joint-stiffness, and pain that is aggravated with heavy use. As the disease advances, nagging pain may also occur during the night or at rest. Diagnosis is predominantly based on clinical and radiological findings. Classic radiographic features of OA do not necessarily correlate with clinical symptoms and appearance. RA involves proximal interphalangeal joints not distal. Gout occurs as a result of overproduction or underexcretion of uric acid and frequently involves first toe. Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues.

Uhthoff’s phenomenon is worsening of vision following a rise in body temperature.
Lhermitte’s sign describes paraesthesia in the limbs on neck flexion.
Oppenheim’s sign is seen when scratching of the inner side of leg leads to extension of the toes. It is a sign of cerebral irritation and is not related to multiple sclerosis.
Werdnig-Hoffman’s disease is also known as spinal muscular atrophy.

Psoriasis is a long-lasting autoimmune disease characterized by patches of skin typically red, dry, itchy, and scaly. Psoriasis can affect the nails and produces a variety of changes in the appearance of finger and toe nails including pitting and onycholysis. Nail psoriasis occurs in 40–45% of people with psoriasis affecting the skin and has a lifetime incidence of 80–90% in those with psoriatic arthritis. Psoriasis is mediated by type 1 helper T cells which are involved in the cell mediated response.

Palmar xanthomas are found in type III hyperlipoproteinemia. Her total cholesterol level and triglyceride level support the diagnosis.

Adverse effects due to IFN-alpha have been described in almost every organ system. Many side-effects are clearly dose-dependent. Taken together, occurrence of flu-like symptoms, haematological toxicity, elevated transaminases, nausea, fatigue, and psychiatric sequelae are the most frequently encountered side effects.

Thyroid malignancies are divided into papillary carcinomas (80%), follicular carcinomas (10%), medullary thyroid carcinomas (5-10%), anaplastic carcinomas (1-2%), primary thyroid lymphomas (rare), and primary thyroid sarcomas (rare).
Hürthle cell carcinoma is a rare thyroid malignancy that is often considered a variant of follicular carcinoma.
– Papillary and Follicular carcinoma are slow-growing tumours
– Sporadic cases of Medullary thyroid carcinoma also typically manifest with painless solitary thyroid nodules in the early stages.
– Anaplastic thyroid carcinoma has the most aggressive biologic behaviour of all thyroid malignancies and has one of the worst survival rates of all malignancies in general. It manifests as a rapidly growing thyroid mass in contrast to a well-differentiated carcinoma, which are comparatively slow-growing. Patients commonly present with associated symptoms due to local invasion. Hoarseness and dyspnoea resulting from the involvement of the recurrent laryngeal nerve and airway occur in as many as 50% of patients.
– Almost all patients with primary thyroid lymphoma have either a clinical history or histological evidence of chronic lymphocytic thyroiditis. The risk of primary thyroid lymphoma increases 70-fold in patients with chronic lymphocytic thyroiditis compared with the general population. Regional and distant lymphadenopathy is common.

Loss of vision after consumption of antifreeze is a characteristic presentation of methanol poisoning.

Pathophysiology of methanol toxicity:
When ingested, methanol is absorbed rapidly via the gastrointestinal tract in less than 10 minutes. Methanol is not protein-bound and is absorbed directly into the total body water compartment.
Metabolism occurs mainly in the liver through serial oxidation via alcohol dehydrogenase and aldehyde dehydrogenase but begins with alcohol dehydrogenase present in the gastric mucosa.
Alcohol dehydrogenase oxidizes methanol to formaldehyde, and aldehyde dehydrogenase subsequently oxidizes formaldehyde to formic acid.
Formic acid is the primary toxic metabolite that accounts for the associated anion gap metabolic acidosis and end-organ damage.

Clinical presentation:
Patients who present within the first 12 to 24 hours following ingestion may appear normal, and this is described as the latent period.
Nausea, vomiting, and abdominal pain subsequently ensue, followed by CNS depression and hyperventilation due to metabolic acidosis.
Ocular symptoms associated with retinal toxicity are often evident in the form of blurry vision, decreased visual acuity, photophobia, and “halo vision.”

Treatment:
Treatment options for methanol toxicity include supportive care, fomepizole (Antizole, 4-Methylpyrazole or 4MP), ethanol, dialysis, and folate.

Interferon alfa alone, not interferon alfa and ribavirin, has been shown to achieve HBeAg seroconversion for patients with HBeAg-positive chronic hepatitis B.

Osteopenia is an early sign of bone weakening that is less severe than osteoporosis.
The numerical result of the bone density test is quantified as a T score. The lower the T score, the lower the bone density. T scores greater than -1.0 are considered normal and indicate healthy bone. T scores between -1.0 and -2.5 indicate osteopenia. T scores lower than -2.5 indicate osteoporosis.
DEXA also provides the patient’s Z-score, which reflects a value compared with that of person matched for age and sex.
Z-score values of –2.0 SD or lower are defined as below the expected range for age and those above –2.0 SD as within the expected range for age.

Rifampicin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription, by forming a stable drug-enzyme complex with a binding constant of 10(-9) M at 37 C.

The cause for bone marrow suppression in this patient is most probably mercaptopurine toxicity.
Azathioprine is metabolized to 6-mercaptopurine (6-MP), which itself is metabolized by xanthine oxidase.
Xanthine oxidase inhibition by allopurinol leads to the accumulation of 6-MP which then precipitates bone marrow failure.
This may be potentially fatal if unrecognized.
Clinical presentation:
Toxicity symptoms include gastrointestinal symptoms, bradycardia, hepatotoxicity, myelosuppression.

Live virus vaccines include: Vaccinia (smallpox), Measles, Mumps, Rubella (MMR combined vaccine), Varicella (chickenpox), Influenza (nasal spray), Rotavirus, Zoster (shingles) and Yellow fever. Inactivated vaccines are Polio (IPV), Hepatitis A and Rabies.

In hyperkalaemia the ECG will show tall, tented T waves as well as small P waves and widened QRS complexes. 

The patient presents with flank pain and fever with haematuria and proteinuria associated with a social history of not being in a steady relationship. This patient is a young presumably sexually active female, so the diagnosis is most likely pyelonephritis which has an increased incidence in young sexually active women or men of >50 years of age.

Nice guidelines for lung reduction surgery:

FEV1 > 20% predicted
PaCO2 < 7.3 kPa
TLco > 20% predicted
Upper lobe predominant emphysema

This patient has pCO2 of 7.4 so she is unsuitable for referral for lung reduction surgery.

Peroneal nerve injury is also known as foot drop. The common peroneal nerve supplies the ankle and toe extensor muscle groups as well as sensation over the dorsum of the foot; thus, there is also loss of sensation in these cases.

Amoebic, bacterial and fungal meningitis may present acutely but is not common in tuberculous meningitis. Amoebic meningitis is caused by Naegleria fowleri as a result of swimming in infected freshwater. The organism may be found in fresh CSF specimens with phase contrast microscopy.

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.