Secretin is a peptide hormone produced in the S cells of the duodenum, which are located in the intestinal glands. In humans, the secretin peptide is encoded by the SCT gene.
Secretin helps regulate the pH of the duodenum by
1) inhibiting the secretion of gastric acid from the parietal cells of the stomach and
(2) stimulating the production of bicarbonate from the ductal cells of the pancreas.
G cells in the antrum of the stomach release gastrin
I cells in upper small intestine release CCK
D cells in the pancreas & stomach secrete somatostatin
K cells secrete gastric inhibitory peptide, an incretin, which also promotes triglyceride storage.

Polycythaemia vera (PV) is associated with a low ESR.

PV, also known as polycythaemia rubra vera, is a myeloproliferative disorder caused by clonal proliferation of marrow stem cells leading to an increase in red cell volume, often accompanied by overproduction of neutrophils and platelets. It has peak incidence in the sixth decade of life, with typical features including hyperviscosity, pruritus, splenomegaly, haemorrhage (secondary to abnormal platelet function), and plethoric appearance. PV is associated with a low ESR.

Some management options of PV include lose-dose aspirin, venesection (first-line treatment), hydroxyurea (slightly increased risk of secondary leukaemia), and radioactive phosphorus (P-32) therapy.

In PV, thrombotic events are a significant cause of morbidity and mortality. 5–15% of the cases progress to myelofibrosis or acute myeloid leukaemia (AML). The risk of having AML is increased with chemotherapy treatment.

Posterior vitreous detachment is thought to occur in up to 50-75% of the population over 65 years and is the most likely diagnosis here. Patients should be reviewed by an ophthalmologist to assess the risk of progressing to retinal detachment. Flashes of light (photopsia) occur in the peripheral field of vision while floaters often occur on the temporal side of the central vision.

Mechanism of action of low molecular weight heparin (LMWH):
It inhibits coagulation by activating antithrombin III. Antithrombin III binds to and inhibits factor Xa. In doing so it prevents activation of the final common path; Xa inactivation means that prothrombin is not activated to thrombin, thereby not converting fibrinogen into fibrin for the formation of a clot.

LMHW is a small fragment of a larger mucopolysaccharide, heparin. Heparin works similarly, by binding antithrombin III and activating it. Heparin also has a binding site for thrombin, so thrombin can interact with antithrombin III and heparin, thus inhibiting coagulation.
Heparin has a faster onset of anticoagulant action as it will inhibit not only Xa but also thrombin, while LMWH acts only on Xa inhibition.

Compared to heparin, LMWHs have a longer half-life, so dosing is more predictable and can be less frequent, most commonly once per day.

Dosage and uses:
LMWH is administered via subcutaneous injection. This has long-term implications on the choice of anticoagulant for prophylaxis, for example, in orthopaedic patients recovering from joint replacement surgery, or in the treatment of DVT/PE.

Adverse effects:
The main risk of LMWH will be bleeding. The specific antidote for heparin-induced bleeding is protamine sulphate.
Less commonly it can cause:
Heparin-induced thrombocytopenia (HIT)
Osteoporosis and spontaneous fractures
Hypoaldosteronism
Hypersensitivity reactions

Desmopressin test (done to differentiate nephrogenic diabetes insipidus from central diabetes insipidus), and serum lithium levels can together confirm a diagnosis of lithium-induced nephrogenic diabetes insipidus.

Bipolar disease is most often managed with mood stabilizers like lithium. This patient develops gastrointestinal symptoms followed by an acute confusional state associated with polyuria and polydipsia. These symptoms are suggestive of diabetes insipidus.

In a case where these symptoms occur in a bipolar patient under treatment, lithium-induced nephrogenic diabetes insipidus should be considered as the most probable cause.

Lithium intoxication can present with symptoms of nausea, vomiting, mental dullness, action tremor, weakness, ataxia, slurred speech, blurred vision, dizziness, especially vertical nystagmus and stupor or coma. Diffuse myoclonic twitching and nephrogenic diabetes insipidus can also occur. Such a clinical syndrome occurs above the serum level of lithium of 1.5–2.0 mEq/L.

Management:
– Correcting electrolyte abnormalities in patients with acute disease is critical and often life-saving.
– Treatment should be initiated with parenteral fluids to replete hypovolemia (normal saline at 200-250 mL/h), followed by administration of hypotonic fluid (0.5% normal saline).
– On the restoration of the volume status of the patient forced diuresis should be initiated by the administration of parenteral furosemide or bumetanide accompanied by continued intravenous hypotonic fluid administration to maintain volume status.
– Polyuria is managed with hydrochlorothiazide combined with amiloride, acetazolamide.

A study conducted showed that the average post smoking cessation weight gain was about 2 kg.
Withdrawal symptoms usually peak after 1–3 days and then decrease over a period of 3–4 weeks. After this time, the body has expelled most of the nicotine, and the withdrawal effects are mainly psychological.

Drug metabolism can be broadly classified into:
Phase I (functionalization) reactions: also termed non-synthetic reactions, they include oxidation, reduction, hydrolysis, cyclization and de-cyclization. The most common and vital reactions are oxidation reactions. (Of the given enzymes only Alcohol dehydrogenase is involved in phase I drug metabolism. Succinate dehydrogenase, is a vital enzyme involved in the Kreb’s cycle and the mitochondrial electron transport chain). They are mainly catalysed by Cytochrome P-450 enzyme.

Phase II (conjugation) reactions: occur following phase I reactions, they include reactions: glucuronidation and sulphate conjugation, etc. They are mostly catalysed by UDP-glucuronosyltransferase enzyme. Other phase II enzymes include: sulfotransferases, N-acetyltransferases, glutathione S-transferases and methyltransferases.

Prevention of osteoporosis associated with chronic glucocorticoid therapy is done by administrating bisphosphonates. Oral bisphosphonates are indicated for patients aged above 65 who have been on steroid therapy for over 3 months, so as to reduce the risk of steroid induced osteoporosis. HRT is usually done in post menopausal women who have oestrogen related bone resorption.

In adults, the most common symptom of meningitis is a severe headache, occurring in almost 90% of cases of bacterial meningitis, followed by nuchal rigidity (the inability to flex the neck forward passively due to increased neck muscle tone and stiffness). Other signs commonly associated with meningitis include photophobia (intolerance to bright light) and phonophobia (intolerance to loud noises).
In the United Kingdom empirical treatment consists of a third-generation cefalosporin such as cefotaxime or ceftriaxone. In the USA, where resistance to cefalosporins is increasingly found in streptococci, addition of vancomycin to the initial treatment is recommended. Penicillins, cephalosporins, carbapenems and monobactams all act via inhibition of cell wall synthesis.

The best treatment for a colovesicular fistula is surgery. This is the only definitive treatment. If the patient is a poor surgical candidate, there can be an attempt to manage them non-operatively, but this is absolutely NOT the MOST EFFECTIVE therapy.

With biliary obstructive symptoms in a patient with ulcerative colitis, one should immediately think of primary sclerosing cholangitis (PSC). PSC is characterized by inflammation and fibrosis of the intrahepatic and extrahepatic ducts. The best diagnostic test for PSC is ERCP. ANCA antibiotics may be positive, but not the best test to DIAGNOSE THE CONDITION. The same can be said of serum transaminase levels– they will be abnormal but nonspecific. While a liver ultrasound may be helpful, it is not the best test. Liver biopsy would be used to stage the PSC later.

Distal renal tubular acidosis is due to defective proton secretion from the alpha intercalated cells of the distal tubule caused by dysfunction of the H+/K+ antiporter on the apical membrane. This leads to failure of H+ excretion thereby causing systemic acidosis and potassium depletion. Inability to lower the urine pH below 5.3 in the presence of systemic acidosis is the diagnostic hallmark of type I or distal renal tubular acidosis. Hypercalciuria, hypocitraturia and elevated urinary pH observed in distal renal tubular acidosis can lead to nephrocalcinosis and may cause renal calculi, obstructive uropathy and renal failure necessitating surgical or endoscopic stone extraction.

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.

The Stages of COPD:
Mild COPD or Stage 1—Mild COPD with a FEV1 about 80 percent or more of normal.
Moderate COPD or Stage 2—Moderate COPD with a FEV1 between 50 and 80 percent of normal.
Severe COPD or Stage 3—Severe emphysema with a FEV1 between 30 and 50 percent of normal.
Very Severe COPD or Stage 4—Very severe or End-Stage COPD with a lower FEV1 than Stage 3, or people with low blood oxygen levels and a Stage 3 FEV1.

This patient has a FEV1 percent of 40 which falls within the stage 2 or moderate COP

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.

The farmer has most likely ingested an organophosphate insecticide.
Organophosphorus compounds are used widely as:
• Insecticides – Malathion, parathion, diazinon, dichlorvos
• Nerve gases – Soman, sarin, tabun, VX
• Ophthalmic agents – Echothiophate
• Antihelmintics – Trichlorfon
• Herbicides – merphos
• Industrial chemical (plasticizer) – Tricresyl phosphate
Signs and symptoms of Organophosphorus Poisoning (OPP) can be classified as:
• Muscarinic effects:
o Cardiovascular – Bradycardia, hypotension
o Respiratory – Rhinorrhoea, bronchorrhea, bronchospasm, cough, severe respiratory distress
o Gastrointestinal – Hypersalivation, nausea and vomiting, abdominal pain, diarrhoea, faecal incontinence
o Genitourinary – Incontinence
o Ocular – Blurred vision, miosis
o Glands – Increased lacrimation, diaphoresis
• Nicotinic effects:
o Muscle fasciculation, weakness, cramping, diaphragmatic failure, and autonomic side effects include: hypertension, tachycardia, and mydriasis.
• Central nervous system (CNS) effects:
o Anxiety, emotional lability, restlessness, confusion, ataxia, tremors, seizures, coma, apnoea
Mainstay Treatment:
• Decontamination
• Securing Airway, Breathing and Circulation
• Atropine
• Pralidoxime
• Benzodiazepines

Given she is not showing signs of systemic illness, you do not need to treat for an acute flair (which would be steroids), but you need to put her on maintenance medication. Oral ASA would be the best option for this, it is first line. You cannot give rectal ASA because the location of her disease is in the ascending colon and the enema will not reach.

High-resolution CT (HRCT) scanning is more sensitive than standard chest radiography and is highly specific for diagnosing emphysema (outlined bullae are not always visible on a radiograph).

HRCT scanning may provide an adjunct means of diagnosing various forms of COPD (i.e., lower lobe disease may suggest AAT deficiency) and may help the clinician to determine whether surgical intervention would benefit the patient.

The incidence rate is the number of new cases per population at risk in a given time period. For example, if a population initially contains 1,000 non-diseased persons and 28 develop a condition over two years of observation, the incidence proportion is 28 cases per 1,000 persons per two years, i.e. 2.8% per two years.
Prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seat-belt use). It is derived by comparing the number of people found to have the condition with the total number of people studied, and is usually expressed as a fraction, as a percentage, or as the number of cases per 10,000 or 100,000 people.
Incidence should not be confused with prevalence, which is the proportion of cases in the population at a given time rather than rate of occurrence of new cases. Thus, incidence conveys information about the risk of contracting the disease, whereas prevalence indicates how widespread the disease is.

Graves’ disease is the most common cause of thyrotoxicosis in pregnancy.

– Poor control of thyrotoxicosis is associated with pregnancy loss, pregnancy-induced hypertension, prematurity, low birth weight, intrauterine growth restriction, stillbirth, thyroid storm, and maternal congestive heart failure.

– Antithyroid drugs are the treatment of choice of hyperthyroidism during pregnancy. The lowest dose of ATD needed to maintain TT4 1.5× the upper limit of the non-pregnant reference range or FT4 at the upper limit of the reference range should be used.
Two different antithyroid drug (ATD) regimens are in common use for Grave’s disease: i) Titration method and ii) Block-and-replace method.
In the titration method, the usual starting dose is 15–30 mg/day methimazole (or equivalent doses of other thionamides); further to periodic thyroid status assessment, daily dose is tapered down to the lowest effective dose (avoiding both hyper- and hypothyroidism).
The block-and-replace method uses persistently high ATD doses in association with L-thyroxine replacement to avoid hypothyroidism; treatment lasts 6 months. This method has advantages and disadvantages over the titration method. Higher doses of ATDs may have a greater immunosuppressive action useful for a permanent remission of hyperthyroidism, but this effect remains to be demonstrated.
Avoidance of hypothyroidism or ‘escape’ of hyperthyroidism seems easier than with the titration method; treatment is shorter, and the number of visits lower. On the other hand, the much higher number of tablets taken every day may create problems of poor compliance. The block-and-replace method should not be used during pregnancy.

– Breastfeeding has been shown to be safe in mothers taking ATDs in appropriate doses.

Night sweats are a B symptom in Hodgkin lymphoma (HL) and imply a poor prognosis.

HL is a malignant proliferation of lymphocytes characterised by the presence of distinctive giant cells known as Reed-Sternberg cells. It has a bimodal age distribution being most common in the third and seventh decades of life.

Staging of HL is done according to the Ann Arbor staging system:

Stage
I: Single lymph node region (I) or one extra lymphatic site (IE)

II: Two or more lymph node regions on same side of the diaphragm (II) or local extra lymphatic extension plus one or more lymph node regions on same side of the diaphragm (IIE)

III: Lymph node regions on both sides of the diaphragm (III) which may be accompanied by local extra lymphatic extension (IIIE)

IV: Diffuse involvement of one or more extra lymphatic organs or sites

Suffix
A: No B symptoms

B: Presence of at least one of the following: unexplained weight loss >10% baseline during 6 months before staging; recurrent unexplained fever >38°C; recurrent night sweats—poor prognosis.

Alpha1-antitrypsin (AAT) deficiency, first described in 1963, is one of the most common inherited disorders amongst white Caucasians. Its primary manifestation is early-onset of pan acinar emphysema. In adults, alpha1-antitrypsin deficiency leads to chronic liver disease in the fifth decade. As a cause of emphysema, it is seen in non-smokers in the fifth decade of life and during the fourth decade of life in smokers.

Symptoms of alpha1-antitrypsin (AAT) deficiency emphysema are limited to the respiratory system. Dyspnoea is the symptom that eventually dominates alpha1-antitrypsin deficiency. Similar to other forms of emphysema, the dyspnoea of alpha1-antitrypsin deficiency is initially evident only with strenuous exertion. Over several years, it eventually limits even mild activities.
The serum levels of some of the common genotypes are:
•PiMM: 100% (normal)
•PiMS: 80% of normal serum level of A1AT
•PiSS: 60% of normal serum level of A1AT
•PiMZ: 60% of normal serum level of A1AT, mild deficiency
•PiSZ: 40% of normal serum level of A1AT, moderate deficiency
•PiZZ: 10–15% (severe alpha 1-antitrypsin deficiency)

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)

The history of diabetes, complete loss of vision in the affected eye and inability to visualise the retina, suggest a diagnosis of vitreous haemorrhage (VH). 3 conditions cause 59 to 88.5% of VH cases: proliferative diabetic retinopathy, posterior vitreous detachment (PVD), and ocular trauma

Difficulty in initiating movement (bradykinesia), postural instability and unilateral symptoms (initially) are typical of Parkinson’s. Essential tremor symptoms are usually worse if arms are outstretched and eased by rest and alcohol.

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are immediately treated with inhaled beta2 agonists and inhaled anticholinergics, followed by antibiotics (if indicated) and systemic corticosteroids. Methylxanthine therapy may be considered in patients who do not respond to other bronchodilators.
High flow oxygen would worsen his symptoms. Usually titrated oxygen (88 to 92 %) is given in such patients to avoid the risk of hyperoxic hypercarbia in which increasing oxygen saturation in a chronic carbon dioxide retainer can inadvertently lead to respiratory acidosis and death.

Sarcoidosis is an inflammatory disease that affects one or more organs but most commonly affects the lungs and lymph glands. The inflammation may change the normal structure and possibly the function of the affected organ(s).
The presentation in sarcoidosis varies with the extent and severity of organ involvement, as follows:
Asymptomatic (incidentally detected on chest imaging): Approximately 5% of cases.
Systemic complaints (fever, anorexia): 45% of cases
Pulmonary complaints (dyspnoea on exertion, cough, chest pain, and haemoptysis [rare]): 50% of cases

Löfgren syndrome (fever, bilateral hilar lymphadenopathy, and polyarthralgias): Common in Scandinavian patients, but uncommon in African-American and Japanese patients.

Dermatologic manifestations may include the following:
– Erythema nodosum
– A lower-extremity panniculitis with painful, erythematous nodules (often with Löfgren syndrome)
– Lupus pernio (the most specific associated cutaneous lesion)
– Violaceous rash on the cheeks or nose (common)
– Maculopapular plaques (uncommon)

Staging of sarcoidosis is as follows:
Stage 0: Normal chest radiographic findings
Stage I: Bilateral hilar lymphadenopathy
Stage II: Bilateral hilar lymphadenopathy and infiltrates
Stage III: Infiltrates alone
Stage IV: Fibrosis

Nonsteroidal anti-inflammatory drugs (NSAIDs) are indicated for the treatment of arthralgias and other rheumatic complaints. Patients with stage I sarcoidosis often require only occasional treatment with NSAIDs.

Treatment in patients with pulmonary involvement is as follows:
Asymptomatic patients may not require treatment
In patients with minimal symptoms, serial re-evaluation is prudent
Treatment is indicated for patients with significant respiratory symptoms
Corticosteroids can produce small improvements in the functional vital capacity and in the radiographic appearance in patients with more severe stage II and III disease.

This patient has Stage 1 Sarcoidosis so observation is the most appropriate action.

Both fibrates and nicotinic acid have been associated with myositis, especially when combined with a statin. However, the Committee on Safety of Medicines has produced guidance which specifically warns about the concomitant prescription of fibrates with statins concerning muscle toxicity.

Bezafibrate: It is a fibric acid derivative (fibrate) that has been used as a class of agents known to decrease triglyceride levels while substantially increasing HDL-C levels.
Pharmacological effects:
– Increases VLDL catabolism by increasing lipoprotein and hepatic triglyceride lipase.
– Decreases triglyceride synthesis by inhibiting acetyl-CoA reductase.
– Decreases cholesterol synthesis by inhibiting HMG-CoA reductase.

Side effects:
– Hypersensitivity
– Primary biliary cirrhosis
– Pre-existing gallbladder disease
– Concurrent use with HMG-CoA inhibitors (statins) can produce myopathy
– Hepatic/renal impairment in a patient warrants dose adjustment as this drug is primarily excreted via the renal mechanism.

Contraindications: Concurrent use of MAO inhibitors, hypersensitivity, pre-existing cholestasis, and pregnancy.

Use: It can be used to treat Barth syndrome (characterized by dilated cardiomyopathy, neutropenia (presenting with recurrent infections), skeletal myopathy and short stature)

Xeroderma pigmentosum is an X-linked recessive condition, which is caused by mutations in DNA gyrase which further encodes the XP gene. The defect may lead to skin cancer at an early stage of life, especially at photo exposed sites.

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.