Many drugs are responsible for causing drug induced lupus. However, it is most commonly associated with hydralazine, procainamide and quinidine.

When statistically comparing data sets, researchers estimate the population of each sample and examine them to see whether they are identical. The standard error of the mean (SEM) – not the standard deviation (SD), which represents the variation in the sample – is used to estimate the population mean. Via this process, researchers conclude that the sample used in their studies appropriately represents the population within the error range specified by the pre-set significance level.
The SEM is smaller than the SD, as the SEM is estimated usually with the SD divided by the square root of the sample size. For this reason, researchers are tempted to use the SEM when describing their samples. It is acceptable to use either the SEM or SD to compare two different groups if the sample sizes of the two groups are equal; however, the sample size must be stated in order to deliver accurate information. For example, when a population has a large amount of variation, the SD of an extracted sample from this population must be large. However, the SEM will be small if the sample size is deliberately increased.

Seasonal affective disorder (SAD) is a type of depression that’s related to changes in seasons. SAD begins and ends at about the same time every year. For most people with SAD, the symptoms start in the fall and continue into the winter months, sapping the person’s energy and making him feel moody. Less often, SAD causes depression in the spring or early summer.

Treatment for SAD may include light therapy (phototherapy), medications and psychotherapy.

Signs and symptoms of SAD may include:
Feeling depressed most of the day, nearly every day
Losing interest in activities you once enjoyed
Having low energy
Having problems with sleeping
Experiencing changes in your appetite or weight
Feeling sluggish or agitated
Having difficulty concentrating
Feeling hopeless, worthless or guilty
Having frequent thoughts of death or suicide.

Seasonal affective disorder is diagnosed more often in women than in men. And SAD occurs more frequently in younger adults than in older adults.

Factors that may increase your risk of seasonal affective disorder include:
Family history. People with SAD may be more likely to have blood relatives with SAD or another form of depression.
Having major depression or bipolar disorder. Symptoms of depression may worsen seasonally if you have one of these conditions.
Living far from the equator. SAD appears to be more common among people who live far north or south of the equator. This may be due to decreased sunlight during the winter and longer days during the summer months.

The patient has hyperinsulinemia and hypoglycaemia, but her C-peptide levels are normal. This is strongly suggestive of the fact that she is self-administering insulin.
In Insulinoma, common diagnostic criteria include:
– blood glucose level < 50 mg/dl with hypoglycaemic symptoms,
– relief of symptoms after eating
– absence of sulfonylurea on plasma assays.
The classic diagnostic criteria include the demonstration of the following during a supervised fast:
Increased plasma insulin level
Increased C peptide level
Increased proinsulin level
However, the patient has normal C-peptide levels.
In type-1 diabetes mellitus, insulin and C-peptide levels are low.

The immunological changes in HIV include depletion in CD4+ T cell, cytokine dysregulation and immune dysfunction. The dominant immunologic feature of HIV infection is progressive depletion of the helper T cell (CD4+ T cell), which reverses the normal CD4:CD8 ratio and subsequently lead to immunodeficiency. Other imuunological changes include:
increased B2-microglobulin
decreased IL-2 production
polyclonal B-cell activation
decreased NK cell function
reduced delayed hypersensitivity responses

NPV = TN / FN+TN

= TN (true negative) / FN+TN (false negative + true negative)

= Probability (patient not having disease when test is negative)

The likely diagnosis in this case is Haemolytic Uremic Syndrome (HUS), which is generally seen in young children presenting with a triad of symptoms, namely: acute renal failure, microangiopathic haemolytic anaemia, and thrombocytopenia. The typical cause of HUS is ingestion of a strain of Escherichia coli.

Right ventricular volume overload is indicated by a parasternal heave and right axis deviation. Oxygen saturation in right atrium is higher than oxygen saturation of the inferior and superior vena cavae. So the most probable diagnosis is atrial septal defect.

The main cause of growth hormone (GH) deficiency is a pituitary tumour or the consequences of treatment of the tumour including surgery and/or radiation therapy.
Sheehan’s syndrome (SS) is postpartum hypopituitarism caused by necrosis of the pituitary gland. It is usually the result of severe hypotension or shock caused by massive haemorrhage during or after delivery. Patients with SS have varying degrees of anterior pituitary hormone deficiency.

Laron syndrome is Insulin-like growth factor I (IGF-I) deficiency due to GH resistance or insensitivity due to genetic disorders of the GH receptor causing GH receptor deficiency.

Both long-acting calcium channel blockers and beta blockers improve symptoms of patients with SVT. Verapamil does not have adverse maternal or fetal side effects which would suggest that the use of verapamil in the treatment of supraventricular arrhythmias in pregnancy is safe and effective. Beta blockers are associated with intrauterine fetal growth restriction.

Urobiligen is produced by the action of bacteria on bilirubin in the intestine. As a reminder, unconjugated bilirubin becomes conjugated in the hepatocyte. Conjugated bilirubin goes through enterohepatic circulation. About half of the urobiligen is reabsorbed and excreted by the kidneys in the urine. The rest is converted to stercobilinogen –> stercobilin, which is excreted in stool, giving it its brown colour.

Idiopathic pulmonary fibrosis (IPF) is a condition in which the lungs become scarred and breathing becomes increasingly difficult.
The most common signs and symptoms of idiopathic pulmonary fibrosis are shortness of breath and a persistent dry, hacking cough. Many affected individuals also experience a loss of appetite and gradual weight loss.

The clinical findings of IPF are bibasilar reticular abnormalities, ground glass opacities, or diffuse nodular lesions on high-resolution computed tomography and abnormal pulmonary function studies that include evidence of restriction (reduced VC with an increase in FEV1/FVC ratio) and/or impaired gas exchange (increased P(A-a)O2 with rest or exercise or decreased diffusion capacity of the lung for carbon monoxide [DLCO]).

Carcinoid tumours are of neuroendocrine origin and derived from primitive stem cells in the gut wall, especially the appendix. They can be seen in other organs, including the lungs, mediastinum, thymus, liver, bile ducts, pancreas, bronchus, ovaries, prostate, and kidneys. While carcinoid tumours tend to grow slowly, they have the potential to metastasise.
Signs and symptoms seen in larger tumours may include the following:
– Periodic abdominal pain: Most common presentation for a small intestinal carcinoid; often associated with malignant carcinoid syndrome.
– Cutaneous flushing: Early and frequent (94%) symptom; typically affects head and neck.
– Diarrhoea and malabsorption (84%): Watery, frothy, or bulky stools, gastrointestinal (GI) bleed or steatorrhea; may or may not be associated with abdominal pain, flushing, and cramps.
– Cardiac manifestations (60%): Valvular heart lesions, fibrosis of the endocardium; may lead to heart failure with tachycardia and hypertension.
– Wheezing or asthma-like syndrome (25%): Due to bronchial constriction; some tremors are relatively indolent and result in chronic symptoms such as cough and dyspnoea.
– Pellagra with scale-like skin lesions, diarrhoea and mental disturbances.
– Carcinoid crisis can be the most serious symptom of the carcinoid tumours and life-threatening. It can occur suddenly or after stress, including chemotherapy and anaesthesia.

Acute angle closure glaucoma is associated with hypermetropia, whereas primary open-angle glaucoma is associated with myopia. Glaucoma is a group of eye disorders characterised by optic neuropathy due, in the majority of patients, to raised intraocular pressure (IOP). It is now recognised that a minority of patients with raised IOP do not have glaucoma and vice versa.

The patient most likely suffers from antiphospholipid syndrome. The clinical criteria consist of vascular thrombosis and pregnancy morbidity. Vascular thrombosis is defined as one or more clinical episodes of arterial, venous, or small-vessel thrombosis in any tissue or organ confirmed by findings from imaging studies, Doppler studies, or histopathology. ASD, VSDs would cause paradoxical emboli and stroke, however the recurrent pregnancy loss in this case is strongly suggestive of antiphospholipid syndrome. The ECG would be normal in most cases associated with anti phospholipid syndrome.

The hazard ratio describes the relative risk of the complication based on comparison of event rates.

Hazard ratios have also been used to describe the outcome of therapeutic trials where the question is to what extent treatment can shorten the duration of the illness. However, the hazard ratio, a type of relative risk, does not always accurately portray the degree of abbreviation of the illness that occurred. In these circumstances, time-based parameters available from the time-to-event curve, such as the ratio of the median times of the placebo and drug groups, should be used to describe the magnitude of the benefit to the patient. The difference between hazard-based and time-based measures is analogous to the odds of winning a race and the margin of victory. The hazard ratio is the odds of a patient’s healing faster under treatment but does not convey any information about how much faster this event may occur.

Methotrexate lung disease (pneumonitis and fibrosis) is the specific etiological type of drug-induced lung disease. It can occur due to the administration of methotrexate which is an antimetabolite, which is given as disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis. The typical clinical symptoms include progressive shortness of breath and cough, often associated with fever. Hypoxemia and tachypnoea are always present and crackles are frequently audible. Symptoms typically manifest within months of starting therapy. Methotrexate withdrawal is indicated in such cases.

Treatment with fibrates, a widely used class of lipid-modifying agents, results in a substantial decrease in plasma triglycerides and is usually associated with a moderate decrease in LDL cholesterol and an increase in HDL cholesterol concentrations.
Evidence from studies is available to implicate 5 major mechanisms underlying the above-mentioned modulation of lipoprotein phenotypes by fibrates:
1. Induction of lipoprotein lipolysis.
2. Induction of hepatic fatty acid (FA) uptake and reduction of hepatic triglyceride production.
3. Increased removal of LDL particles. Fibrate treatment results in the formation of LDL with a higher affinity for the LDL receptor, which is thus catabolized more rapidly.
4. Reduction in neutral lipid (cholesteryl ester and triglyceride) exchange between VLDL and HDL may result from decreased plasma levels of TRL.
5. Increase in HDL production and stimulation of reverse cholesterol transport. Fibrates increase the production of apoA-I and apoA-II in the liver, which may contribute to the increase of plasma HDL concentrations and a more efficient reverse cholesterol transport.

The chronic asymptomatic carrier state is thought to be why there is continued appearance of the bacterium in human populations. As shedding of the organism is intermittent and sometimes at low levels, methods to detect it have been limited. The Salmonella typhi may be cultured from intestinal secretions, faeces or urine in chronic carriers and is recommended to confirm the diagnosis. Vi agglutination test can also be high in normal people in areas with typhoid endemic. Full blood count or blood culture would not be helpful to determine carrier status. Widal antigen test is unable to differentiate carriers from people with a hx of prior infection.

Breast cancer has a lower incidence in HIV positive patients. Seminoma, Hodgkin’s disease, anal cancer, and non-small cell lung cancer are all increased incidence. Memorize this breast cancer fact.