The answer is: D

Respiratory syncytial virus (RSV) is the most important cause of pneumonia and bronchiolitis in infants. The infection is localized to the respiratory tract. The virus can be detected rapidly by immunofluorescence on smears of respiratory epithelium. In older children, the infection resembles the common cold. Aerosolized ribavirin is recommended for severely ill hospitalized infants.

The answer is: D

Kuru and Creutzfeldt-Jakob disease (CJD) are similar but not identical diseases with very different epidemiology. Kuru is prevalent among certain tribes in New Guinea who practiced ritual cannibalism by eating the brains of the departed. CJD is found worldwide and has been transmitted by corneal transplants and in pituitary hormone preparations. There is some association between CJD and Mad Cow Disease in England. Prions are unconventional selfreplicating proteins, sometimes called amyloid. It is now thought that CJD, Kuru, and animal diseases such as scrapie, visna, and bovine spongiform encephalopathy (Mad Cow Disease) are caused by prions.

The answer is: D

Aseptic meningitis is characterized by a pleocytosis of mononuclear cells in the cerebrospinal fluid; polymorphonuclear cells predominate during the first 24 h, but a shift to lymphocytes occurs thereafter. The cerebrospinal fluid of affected persons is free of culturable bacteria and contains normal glucose and slightly elevated protein levels. Peripheral white blood cell counts usually are normal. Although viruses are the most common cause of aseptic meningitis, spirochetes, chlamydiae, and other microorganisms also can produce the disease.

The answer is: B

Human papillomavirus (HPV) is the cause of genital warts. It is one of the most pervasive of all the sexually transmitted diseases. There is no specific cure or vaccine. There are multiple serotypes of papillomavirus and some serotypes are linked to cervical cancer. New techniques for molecular diagnosis of HPV show promise for rapid and sensitive detection and perhaps more aggressive treatment.

The correct answer is C

Explanation

Coagulative necrosis occurs five to six hours after the infarction occurs.

• Collagen synthesis (choice a) occurs at the site of the infarction three to six weeks after a myocardial infarction.
• Contraction (choice b) of the scar tissue occurs four to six weeks after the myocardial infarction.
• Influx of eosinophils, lymphocytes and plasma cells (choice d) occurs approximately two weeks after an infarction.
• New capillaries at the site of infarction (choice e) occurs after about a week.

The correct answer is C

Explanation

The lesion described are called telangiectasia. Hereditary hemorrhagic telangiectasia is also called Osler-Rendu-Weber. It is autosomal dominant, which explains why her father had it as well.

• Sturge-Weber syndrome (choice a) is associated with port-wine stain on the face.
• The cutaneous manifestations of Von Recklinghausen disease (choice b) are cafe au lait spots and neurofibromatosis, not telangiectasias.
• The lesions of Kaposi sarcoma (choice d) are dark blue-red papules and nodules.
• Although the lesions of Peutz-Jeghers syndrome (choice e) affect the oral mucosa, and it also is inherited by an autosomal dominant mechanisms, the lesions are tan-brown and do not result in bleeding

The correct answer is A

Explanation
In the diagnostic evaluation of the woman with withdrawal bleeding , an LH and FSH level may be helpful. If the LH is high (above about 10 MIU/ml) and the LH/FSH ratio is above 2:1, this supports the clinical diagnosis of polycystic ovarian disease

The correct answer is D

Explanation
A vaginal lubricant would be appropriate since although most of the estrogen acts locally, some of it is rapidly absorbed into the systemic circulation

Answer: D

This patient has many potential causes for a hypercoagulable state including bedrest, possible HIT from heparin flushes in his central venous catheter, carcinoma, and a possible inherited predisposition to thrombosis as suggested by his previous DVT. In terms of tests that should be done at this time, the genetic tests can be accurately interpreted, but should be done on a tissue sample different from the usual peripheral blood leukocyte sample due to the circulating white cells from the transplant donor.

The other tests should not be performed until the patient is stable and more time has passed after the acute event and the treatment for it is completed. The patient currently has liver function abnormalities that might affect his synthetic function, so the coagulation screening tests and the protein C, protein S, and antithrombin levels may be abnormal; however, they would not be indicative of a hereditary thrombophilia.

Reference:

1. Seligsohn U, Lubetsky A. Genetic suseptibility to venous thrombosis. New Eng J Med 2001; 344:1222-31.

Answer: E

Patients with CLL may have aberrant immune responses that include the development of antibodies to coagulation factors. In this case, the patient had a low factor VIII ( and, on further testing, low VWF) due to an acquired antibody to VWF leading to clearance and decreased levels of VWF and factor VIII. A lupus anticoagulant or a decreased factor XII would not be expected to lead to bleeding, which the patient reports. Although decreased factor IX or factor XI levels could lead to bleeding, there is no past history or family history of bleeding, and acquired antibodies to these factors are exceedingly rare.

References:

1. Tefferi A, Nichols WL. Acquired von Willebrand disease: concise review of occurrence, diagnosis, pathogenesis, and treatment. Am J Med 1997;103:536-40.

2. Veyradier A, Jenkins CSP, Fressinaud E, Meyer D. Acquired von Willebrand syndrome: from pathophysiology to management. Thromb Haemost 2000; 84:175-82.

Answer: B

An alpha2 antiplasmin deficiency will cause bleeding, particularly after an invasive procedure when the fibrinolytic system is activated, and (as seen in this case) it will not cause abnormalities in the screening coagulation studies. The normal screening coagulation studies in the patient make it very unlikely that coagulation screening of the mother, a factor XI level, or a d-Dimer will be helpful in this evaluation. Electron microscopic study of the patient’s platelets is not indicated in the face of the normal platelet studies that have been reported.

References:

1. Saito H. ₂-plasmin inhibitor and its deficiency states. J Lab Clin Med 1988; 112:671-78.

2. Miles LA, Plow EF, Donnelly KJ, Hougie C, Griffin JH. A bleeding disorder due to deficiency of alpha 2-antiplasmin. Blood 1982; 59:1246-51.

The correct answer is A

Explanation

• Vitamin B9, also called folic acid or folate, is one of eight water-soluble B vitamins. All B vitamins help the body to convert carbohydrates into glucose (sugar), which is "burned" to produce energy.
  
• These B vitamins, often referred to as B complex vitamins, are essential in the breakdown of fats and protein.
  
• B complex vitamins also play an important role in maintaining muscle tone along the lining of the digestive tract and promoting the health of the nervous system, skin, hair, eyes, mouth, and liver.

1. Folic acid is crucial for proper brain function and plays an important role in mental and emotional health. It aids in the production of DNA and RNA, the body's genetic material, and is especially important during periods of high growth, such as infancy, adolescence and pregnancy.
   
2. Folic acid also works closely together with vitamin B12 to regulate the formation of red blood cells and to help iron function properly in the body.

• Vitamin B9 works closely with vitamins B6 and B12 as well as the nutrients betaine and S-adenosylmethionine (SAMe) to control blood levels of the amino acid homocysteine.
• Elevated levels of this substance appear to be linked to certain chronic conditions such as heart disease and, possibly, depression and Alzheimer's disease.

The correct answer is D
Explanation

Manifestations of Vitamin K deficiency include hypoprothrombinemia ,hemorrhaagic diathesis, an increased tendency to bleeding and a prolonged coagulation time. Vitamin K is required for gamma-carboxylation of glutamic acid residues of the procoagulant Factors II (prothrombin), VII, IX, and X and the anticoagulant factors protein C and protein S Severe vitamin K deficiency can lead to a hemorrhagic diathesis that is characterized by prolongations of the PT and sometimes also the aPTT.

The PT is more sensitive than the aPTT in detecting vitamin K deficiency states because Factor VII, the only one of the vitamin K-dependent factors that is in the extrinsic pathway of coagulation, is the most labile of these proteins. The two major sources of vitamin K are dietary intake and synthesis by the bacterial flora of the intestine.

Therefore, in the absence of malabsorption, nutritional deficiency alone rarely causes clinically significant vitamin K deficiency. However, such a condition can arise when eradication of gut flora is combined with inadequate dietary intake. This situation typically occurs in critically ill patients in intensive care units who have no oral intake and are receiving broad-spectrum antibiotics for prolonged periods. Vitamin K deficiency can also develop in patients receiving total parenteral nutrition unless the infusions are supplemented with vitamin K

The correct answer is B

Explanation

Trimetaphan appears to work by competitive block of ACh receptors. Mecamylamine is also a blocker of neuronal nicotinic receptors, initially developed as an antihypertensive ganglionic blocker, abandoned because of postural hypotension, and now of interest because its noncompetitive voltage-dependent interference with nicotinic receptors makes it significant in the study of addiction

The correct answer is B

Explanation

class Ib
- shorten action potential
- limited effect on rate of rise of phase 0
- shorten repolarization
- shorten QT
- raise fibrillation threshold
- mild-moderate sodium channel blockade
- little effect on refractoriness since there is essentially no blockade of potassium channels
- eg lignocaine, mexilitine, phenytoin, propafenone

The correct answer is B
Explanation

class Ib
- shorten action potential
- limited effect on rate of rise of phase 0
- shorten repolarization
- shorten QT
- raise fibrillation threshold
- mild-moderate sodium channel blockade
- little effect on refractoriness since there is essentially no blockade of potassium channels
- eg lignocaine, mexilitine, phenytoin, propafenone

The correct answer is D
Explanation

Class II
- decrease potential for arrhythmias to develop in response to catecholamines
- eg bretylium: blocks release of sympathetic transmitters
- beta blockers: competitive antagonists and also block possible arrhythmogenic effect of cAMP
- indirect blockade of Ca channel opening by attenuating adrenergic activation

PThe correct answer is D

Explanation

Class III
- K channel blockers: prolong duration of action potential with resulting prolongation of effective refractory period
- eg amiodarone, sotalol, disopyramide, bretylium

The correct answer is C
Explanation

Zollinger-Ellison syndrome is caused by excessive gastrin production and is usually due to a gastrinoma (90%)of the pancreas.The diagnosis should be suspected in the case of peptic ulcers failing to respond to drug therapy and repeated episodes of diarrhea and steathorrea (as in this case) Antral G cell hyperplasia is present in 10%. The commonest location is the duodenal bulb, followed by the stomach and then the postbulbar dusodenum. Gastro-esophageal reflux (as in this case)is a complication rather than a cause and is present in most of these patients and often complicated by esophagitis.

Tags: MCQS, Medicine, Gastroenterology, Zollinger-Ellison

The correct answer is D

Explanation

Valproic acid is a drug of choice for:

Generalized epilepsy of unknown cause that produces more than one type of seizure. Absence seizures.

Ethosuximide is the other drug of choice.

If a person has absence seizures as well as other types of seizures, however, valproic acid usually works better because it can control several types of seizures.
Myoclonic seizures, such as those caused by juvenile myoclonic epilepsy.

Clonazepam may be used when valproic acid does not work.

Valproic acid is also considered a first-line drug for treating partial seizures.

The correct answer is E
Explanation

Beta-1 selective blockers

These include atenolol and metoprolol (as well as betaxolol, bevantolol, and perhaps esmolol).

Metoprolol
This beta blocker lacks ISA and MSA; one can deduce its metabolism and short half-life from its lipophilicity. Some slow-release formulations of metoprolol have peculiar doses.

Atenolol

Examination candidates should probably know this agent fairly well. Important topics to discuss would be its water solubility, metabolism, ß-1 selectivity, and recent studies showing improved post-operative survival even after very short-term use in the peri-operative period.

Esmolol
This beta blocker is relatively beta-1 selective. hydrolysis by nonspecific esterases accounts for its tiny half-life of about 9 minutes. The traditional approach of starting therapy with a 0.5mg/kg IV bolus is excessive,and potentially life-threatening. Be more gentle. This agent has been much abused to "manage tachycardia" intra-operatively, where the anaesthetist should rather be thinking about the cause of the tachycardia, for example, pain)!

Non-selective beta blockers
There's a confusing array of these agents, including propranolol, nadolol, pindolol, sotalol, oxprenolol and timolol. From a practical (and examination) point of view, it's probably important to know the following well:
propranolol

(Note its lipophilicity and consequent hepatic metabolism, lack of ISA, irrelevant MSA, short half-life, and several exotic effects including inhibition of peripheral conversion of thyroxine to T3, as well as shift of the Hb:O2 dissociation curve to the right)! carvedilol;

The correct answer is B
Explanation

Parathion is a commonly used insecticide which belongs to organophosphorous group of chemicals. Poisoning due to parathion occurs usually in farming areas where it is used as an insecticidal agent. Parathion acts by irreversible inhibition of the enzyme acetylcholine esterase which is responsible for the breakdown of acetylcholine. Normally acetylcholine binds to the esteratic site of the enzyme resulting in acetylation of the enzyme. The acetylated enzyme reacts with water resulting in breakdown of acetylcholine and release of free enzyme.

Parathion also binds to the esteratic site of the enzyme acetylcholine esterase but in this case the enzyme does not react with water and the enzyme undergoes irreversible inhibition. This results in accumulation of acetylcholine resulting in severe cholinergic overactivity. The severity of the symptoms depends on the exposure dose of parathion. In small to moderate doses it causes salivation, vomiting, abdominal cramps, lacrimation etc. it also causes respiratory distress due to large amount of tracheo-bronchial secretions.

In large doses it can cause convulsions and death due to respiratory paralysis. Specific antidote used is 2-Pralidoxime. 2-Pralidoxime has a quaternary nitrogen which attaches to the anionic site of the enzyme. The oxime part of 2-Pralidoxime reacts with the phosphorous atom of parathion forming an oxime-phosphonate which diffuses away leaving behind the reactivated enzyme. In this way 2-pralidoxime reactivates the inhibited enzyme and acts as a specific antidote for parathion poisoning.

• Atropine is also used for the treatment of parathion poisoning but it only serves as a physiological antagonist of acetylcholine and provides symptomatic relief. It does not reactivate the enzyme therefore it is not a specific antidote.
• Diazepam is used to control the convulsions due to the poisoning and is not a specific antidote.
• Amyl nitrite is used in cyanide poisoning and not in parathion poisoning.
• Physostigmine itself is an inhibitor of the enzyme acetylcholine esterase and would further worsen the symptoms of parathion poisoning if administered.

The correct answer is A
Explanation

Spironolactone is effective in lowering the systolic and diastolic blood pressure in patients with primary hyperaldosteronism. It is also effective in most cases of essential hypertension, despite the fact that aldosterone secretion may be within normal limits in benign essential hypertension.

Through its action in antagonizing the effect of aldosterone, spironolactone inhibits the exchange of sodium for potassium in the distal renal tubule and helps to prevent potassium loss.

Hyperkalemia: Hyperkalemia may occur in patients treated with spironolactone if the potassium intake is excessive. This can cause cardiac irregularities, some of which may be fatal. Hyperkalemia may also occur even in the absence of potassium supplementation, particularly in patients with impaired renal function, elderly patients, or patients with diabetes. Consequently, no potassium supplementation should ordinarily be given with spironolactone. Hyperkalemia can be treated promptly by rapid i.v. administration of glucose (20 to 50%) and regular insulin, using 0.25 to 0.5 units of insulin/g of glucose. This is a temporary measure to be repeated if required. Spironolactone should be discontinued and potassium intake (including dietary potassium) restricted.

Hyponatremia: During the administration of spironolactone, patients suffering from sodium depletion must be attentively monitored and signs of electrolyte imbalance must be carefully checked.
Spironolactone may, if administered concomitantly with other diuretics, cause or aggravate hyponatremia, as manifested by dryness of the mouth, thirst, lethargy, and drowsiness.

Metabolic Effects: Hyperchloremic metabolic acidosis: Spironolactone may induce or worsen hyperchloremic metabolic acidosis.

The correct answer is D
Explanation

Recognised complications of Quinidine.

Hypotension and a reflex increase in heart rate. Due to peripheral vasodilation.
Depresses vagal tone. Due to an antimuscarinic action (works against direct effect on SA and AV nodes).

Torsades de pointes. A potentially life-threatening proarrhythmia.

Cinchonism. A syndrome characterized by nausea, vomiting, diarrhea, tinnitus, headache, auditory and visual disturbances and vertigo.

Hypersensitivity reactions (rashes, fever, angioneurotic edema hepatitis) and reversible thrombocytopenia.

The correct answer is E
Explanation

Phenytoin is approximately 90 per cent bound to serum albumin. Therefore, in an initial total plasma phenytoin concentration of 20ìg/ml represents the sum of the protein bound drug (90 per cent of 20 = 18ìg/ml) and the unbound drug (10 per cent of 20 = 2ìg/ml). The unbound drug is available for distribution to the site of therapeutic effect (ie, the brain), peripheral tissues, and the site of elimination (the liver). The bound drug is confined to the bloodstream.

The correct answer is B
Explanation

Primary treatment of gastroparesis includes dietary manipulation and administration of antiemetic and prokinetic agents.Dietary recommendations include eating frequent smaller-size meals and replacing solid food with liquids, such as soups. Foods should be low in fat and fiber content.

Antiemetic agents are administered for nausea and vomiting. The principal classes of antiemetic drugs are antidopaminergics, antihistamines, anticholinergics, and more recently serotonin receptor antagonists. The antiemetic action of phenothiazine compounds is primarily due to a central antidopaminergic mechanism in the area postrema of the brain. Commonly used agents include prochlorperazine, trimethobenzamide, and promethazine.

Serotonin (5-HT3) receptor antagonists are helpful in treating or preventing chemotherapy-induced nausea and vomiting. The sites of action of these compounds include the area postrema as well as peripheral afferent nerves. These agents are frequently used for nausea and vomiting due to other etiologies with little published evidence demonstrating their efficacy. These agents are best used on an as-needed basis.

Current prokinetic agents include metoclopramide and erythromycin, which can be administered orally or intravenously.

Patients refractory to the initial treatment of gastroparesis can be difficult to manage. Treatment may involve switching prokinetic and antiemetic agents, combining prokinetic agents, injecting botulinum toxin into the pylorus, using gastrostomy/jejunostomy tubes, and implanting a gastric electric stimulator.

A treatment recently reported to be helpful for refractory gastroparesis is endoscopic injection of botulinum toxin into the pyloric sphincter. Botulinum toxin, which reduces the release of acetylcholine from cholinergic nerves, may relax pyloric sphincter resistance, allowing more food to empty from the stomach.

Decompressing gastrostomy and feeding jejunostomy tubes are occasionally used when necessary. A jejunostomy tube may provide a route for administering enteral nutrition, hydration, and medications.

Gastric electric stimulation is an emerging therapy for refractory gastroparesis. There are several ways to stimulate the stomach by varying the electrical parameters. With gastric electrical pacing, the goal is to entrain and pace the gastric slow waves at a higher rate than the patient's normal myoelectric frequency.

Answer: D

Although the history initially suggests ITP, further questioning indicates that the patient has a life-long bleeding history and that her father may have a bleeding disorder. Additionally, the patient did not respond to treatment with prednisone.

Although the results of the VWF activity and antigen were within the normal reference range, they should be increased above normal (approximately twice normal) at this point in the patient’s pregnancy.

Type 2B VWD can cause this clinical picture with worsening thrombocytopenia during pregnancy; this is due to the increased synthesis of VWF that normally occurs in later pregnancy, leading to a higher level of the abnormal VWF in the circulation that binds to platelets and causes small aggregate formation and clearance of the platelets.

A VWF multimer study will reveal a decrease in the highest molecular weight multimers of VWF. A ristocetin-induced platelet aggregation study can be attempted, but the low platelet numbers would likely make this test difficult to interpret (one would expect aggregation with low concentrations [<0.60>

Platelet aggregation studies would be difficult to carry out due to the low count, and the size distribution of platelets will not yield a specific diagnosis. The thromboelastogram test also will not indicate a specific diagnosis, and a bleeding time will be prolonged due to the low platelet count.

Reference:

1. Rick ME, Williams SB, Sacher RA, McKeown LP. Thrombocytopenia associated with pregnancy in a patient with type IIB von Willebrand’s disease. Blood 1987; 69:786-89.

The answer is: B

HSV meningitis or encephalitis is difficult to diagnose by laboratory tests as there is a low titer of virus present in the CSF. Neonatal HSV infects the child during the birth process. While culture, Tzanck smear, and even antibody tests may be useful in adults, particularly those with HSV-rich lesions, they are not useful for CSF testing. Only PCR is sensitive enough to detect HSV DNA in the CSF. Once diagnosed rapidly, HSV encephalitis or meningitis can be treated with acyclovir.

The correct answer is A

Explanation

The incidence of hyponatremia associated with Chlorpropamide is about 7 percent. The majority of patients are mildly hyponatremic with serum sodium concentrations between 130 and 134 mmol/L. The incidence of Chlorpropamide-induced syndrome of inappropriate antidiuretic hormone is 2 percent. Concurrent angiotensin-converting enzyme (ACE) inhibitor is identified as a risk factor; thiazide diuretic use is not.

The answer is: B

Rubella virus does not produce cytopathic effects (CPEs) in tissue-culture cells. Moreover, rubella-infected cells challenged with a picornavirus are resistant to subsequent infection and thus would not exhibit CPEs. Monkey kidney cells infected only with picornavirus would show CPEs.

The correct answer is B
Explanation

Primary treatment of gastroparesis includes dietary manipulation and administration of antiemetic and prokinetic agents.

Dietary recommendations include eating frequent smaller-size meals and replacing solid food with liquids, such as soups. Foods should be low in fat and fiber content.
Antiemetic agents are administered for nausea and vomiting. The principal classes of antiemetic drugs are antidopaminergics, antihistamines, anticholinergics, and more recently serotonin receptor antagonists. The antiemetic action of phenothiazine compounds is primarily due to a central antidopaminergic mechanism in the area postrema of the brain. Commonly used agents include prochlorperazine, trimethobenzamide, and promethazine.

Serotonin (5-HT3) receptor antagonists are helpful in treating or preventing chemotherapy-induced nausea and vomiting. The sites of action of these compounds include the area postrema as well as peripheral afferent nerves. These agents are frequently used for nausea and vomiting due to other etiologies with little published evidence demonstrating their efficacy. These agents are best used on an as-needed basis.

Current prokinetic agents include metoclopramide and erythromycin, which can be administered orally or intravenously.

Patients refractory to the initial treatment of gastroparesis can be difficult to manage. Treatment may involve switching prokinetic and antiemetic agents, combining prokinetic agents, injecting botulinum toxin into the pylorus, using gastrostomy/jejunostomy tubes, and implanting a gastric electric stimulator.

A treatment recently reported to be helpful for refractory gastroparesis is endoscopic injection of botulinum toxin into the pyloric sphincter. Botulinum toxin, which reduces the release of acetylcholine from cholinergic nerves, may relax pyloric sphincter resistance, allowing more food to empty from the stomach.
Decompressing gastrostomy and feeding jejunostomy tubes are occasionally used when necessary. A jejunostomy tube may provide a route for administering enteral nutrition, hydration, and medications.

Gastric electric stimulation is an emerging therapy for refractory gastroparesis. There are several ways to stimulate the stomach by varying the electrical parameters. With gastric electrical pacing, the goal is to entrain and pace the gastric slow waves at a higher rate than the patient's normal myoelectric frequency.

Answer: C

In this case where there have been several past cardiac surgical procedures, the chances are high that the patient was exposed to “fibrin glue” which contains bovine thrombin (and bovine factor V in this semi-purified preparation). Inhibitors to bovine thrombin and factor V commonly develop, and although the antibody to bovine thrombin usually does not cross react with human thrombin, the antibody to factor V frequently cross reacts with human factor V and can cause serious bleeding. A factor V test showing a decreased level should be followed by a factor V inhibitor assay to confirm this; a thrombin time performed with human thrombin as the reagent would be normal. DIC is not likely in the presence of a normal platelet count and this degree of abnormality in the coagulation tests. A hereditary dysfibrinogenemia could cause prolonged assays in all 3 tests noted above, but it is not likely to cause bleeding, and it was not detected on the previous testing. A lupus anticoagulant would not cause a prolonged thrombin time. Heparin would not be expected to cause this prolongation of the prothrombin time, and thrombin time would be greater than 2 minutes if the aPTT is increased to 51 seconds by heparin.

References:

1. Zehnder JL, Leung LLK. Development of antibodies to thrombin and factor V with recurrent bleeding in a patient exposed to topical bovine thrombin. Blood 1990; 76:2011-16.

2. Ortel TL, Charles LA, Keller FG, Marcom PK, Oldham HN, Kane WH, Macik BG. Topical thrombin and acquired coagulation factor inhibitors. Amer J Hemat 1994; 45:128-35.

Answer: E

The history suggests a possible autoimmune disease (such as Systemic Lupus Erythematosis) as well as a lymphoma. The prolonged aPTT that only partially corrects with a 1:1 mixing study indicates an inhibitor, while the total correction of the prothrombin time on 1:1 mix suggests a deficiency. A lupus anticoagulant with an associated factor II (prothrombin) deficiency due to an antibody that complexes with prothrombin (affecting clearance but not affecting the active site of thrombin) will cause this pattern of laboratory results. von Willebrand disease would cause only a prolonged aPTT, and a factor V deficiency or inhibitor would not be expected to give this pattern of correction in the 1:1 mixing studies (either both assays would be corrected or both would not be corrected). DIC is unlikely because the aPTT is prolonged out of proportion to the prothrombin time and degree of thrombocytopenia, and the patient has no bleeding symptoms. Platelet antibodies, while they might be positive in this setting, would not account for the abnormal coagulation parameters.

References:

1. Fleck RA, Rapaport SI, Rao VM. Anti-prothrombin antibodies and the lupus anticoagulant. Blood 1988; 72:512-9.

2. Pernod G, Arvieux J, Carpentier PH, Pascal M, Bosson J Luc, Benoît P. Successful treatment of lupus anticoagulant-hypoprothrombinemia syndrome using intravenous immunoglobulins. Thromb Haemost 1997; 78:969-70.

The answer is: E

The advent of triple therapy or a therapeutic "cocktail" has had a marked effect on AIDS patients. The combination of drugs work together as reverse transcriptive inhibitors and a protease inhibitor. Patients improve rapidly, their CD4 lymphocyte counts increase, and their HIV viral load is drastically reduced, often to <50>

On the other hand, an untreated HIV-positive patient with a low CD4 and a high viral load

(a) is at increased risk of opportunistic infection and

(b) has a much greater chance of developing AIDS than if the viral load was <50,000.>

The patient is infectious and his HIV antibody screening test will be positive. The high viral load, however, is not a predictor of response to therapy. Many patients with high viral loads do very well on triple therapy, although resistance to one or more of the agents may subsequently occur. A low CD4 count does not predict progression to AIDS but does indicate increased chance of opportunistic infection such as those listed.

Kaposi’s sarcoma, which has been linked to herpesvirus type 8, pneumocystis, and mycobacterial disease are three of the most prevalent opportunistic infections. While HIV-positive patients contract pneumococcal pneumonia, they are probably at no more risk than the general population, as protection against pneumococcal disease is linked to the presence of anticapsular antibody.

Answer: B

Surface antigens	M1/M2	M3	M4/M5	M6	M7
HLA-DR	+	-	+	-	+
CD11	+	+	+	-	-
CD13	+	+	+	-	-
CD14	+	-	+	-	-
CD33	+	+	+	+	+
CD41/61	-	-	-	-	+
Glycophorin A	+	-	-	+	-

Weir, E.G., Borowitz, M.J. Flow cytometry in the diagnosis of acute leukemia. Seminars in Hematology. 2001, 38:124-128.

Answer: B

Primary mediastinal large B cell lymphomas demonstrate a diffuse large cell proliferation. Sclerosis is present in most cases. The neoplastic cells have a large transformed cell appearance. This type of lymphoma is most common in females and has a proclivity for local invasion and superior vena cava obstruction. The neoplastic cells are CD19, CD20, CD22 positive, they are negative for CD5, CD10, CD30, CD15 and in general do not express surface immunoglobulin. Non-Burkitt small transformed cell lymphomas are positive for CD45, CD19, CD20, CD10 and surface immunoglobulins. B lymphoblastic lymphomas express CD19, CD20, CD10 and do not express surface immunoglobulins. Reed-Sternberg cells are typically CD45-, CD30+ and CD15+.

Follicular hyperplasia is diagnosed morphologically.

Davis, R.E., Dorfman, R.F., Warnke, R.A. Primary large-cell lymphoma of the thymus: a diffuse B-cell neoplasm presenting as primary mediastinal lymphoma. Hum. Pathol, 1990, 21: 1262-1268.

Answer: C

The autoimmune lymphoproliferative syndrome (ALPS) arises in early childhood in patients who inherit mutations in genes that mediate apoptosis. ALPS is inherited in an autosomal dominat fashion. The syndrome is defined as chronic, non-malignant lymphoproliferation associated with an elevated percentage (>1%) of double negative T lymphocytes (CD3+, CD4-, CD8-) and defective lymphocyte apoptosis. Autoimmune syndromes are commonly associated with ALPS. The most common autoimmune diseases are hemolytic anemia and ITP. Most cases of ALPS are associated with specific Fas mutations; mutations in other apoptosis genes are thought to underlie cases in patients with normal Fas. Peripheral blood or tissues, show no evidence of clonality or chromosome abnormalities.

Straus, S.E., Sneller, M., Lenardo, M.J., Puck, J.M.,Strober, W. An inherited disorder of lymphocyte apoptosis: The autoimmune lymphoproliferative syndrome. Ann.Int.Med, 1999,130:591-601.

Answer : 1

Lower esophageal sphincter tone is decreased by:

- Pregnancy
- Obesity
- Smoking, Alcohol
- Fatty foods, large meals, chocolate
- Diseases such as diabetes

The lower esophageal sphincter (LES) is a ring of muscle that forms a valve at the lower end of the esophagus, where it joins the stomach.

The LES remains closed except during swallowing, when it allows food to pass from the esophagus into the stomach. When the LES is closed, it prevents the backflow (reflux) of stomach acid into the esophagus. If the LES does not close tightly enough, stomach acid backs up into the esophagus, causing heartburn. A weak lower esophageal sphincter is a major cause of gastroesophageal reflux disease (GERD).

Answer: D

Mast cell disease is associated with irregular and patchy marrow infiltration. The majority of mast cells are the fusiform type and contain a variable number of granules. Fibrosis accompanies mast cell infiltrates. Abundant numbers of eosinophils and foci of reactive lymphocytes are present near the mast cell foci. Uninvolved marrow is usually normal.

Giemsa, toluidine blue, aldehyde-fuschin, astra blue, chloroacetate esterase and tryptase stains are strongly positive in mast cells.

Bain, B.J. Systemic mastocytosis and other mast cell neoplasms. Br. J. Haematol. 1999, 106: 9-17.

Answer: D

( MDS: myelodysplastic syndrome, AML: acute myeloid leukemia, LGL: Large granular lymphocyte )

Hairy cell leukemia (HCL) is most often associated with cytopenias. Anti-CD20 is a highly sensitive immunohistochemical stain for B cells and, thus, is more sensitive for diagnosing HCL than TRAP, but the TRAP stain is more specific. The bone marrow in HCL is very often hypocellular, dysplastic changes are usually not present. Aplastic anemia, myelodysplastic syndrome , hypocellular AML and LGL syndrome are part of the differential diagnosis in a cytopenic patient with mild splenomegaly and an hypocellular marrow; large aggregates of CD20 positive lymphocytes are not seen in these disorders.

Pettitt, A.R., Zuzel, M., Cawley, J.C. Hairy cell leukemia: Biology and management. Br.J.Haematol, 1999, 106:2-8.

The correct answer is A

Explanation

• The optochin test is a presumptive test that is used to identify strains of Streptococcus pneumoniae.
• Optochin (ethyl hydrocupreine) disks are placed on inoculated blood agar plates. Because S. pneumoniae is not optochin resistant, a zone of inhibition will develop around the disk where the bacteria have been lysed. This zone is typically 14mm from the disk or greater.
• Streptococcus pneumoniae is a gram-positive coccus that in clinical specimens often appears in pairs with tapered ends (lancet shaped), although it grows in short chains on nutrient broth media.
• It is a relatively fastidious facultative anaerobe and requires increased carbon dioxide for optimum recovery from clinical specimens .
  
• Susceptibility to ethyl hydrocupriene hydrochloride (Optochin) distinguishes pneumococci from other streptococci in the clinical microbiology laboratory.

The correct answer is E

Explanation
 
The earliest ECG evidence of hyperkalemia usually appears in the T waves The variety of changes include: Increased amplitude and peaking of the T wave PR interval prolongation QRS interval prolongation Flattening of the P wave. A plasma potassium of >6.5mmol/l should be treated urgently unless it is an artefact.

Hyperkalemia may have a variety of causes: Renal failure; Excess potassium replacement therapy;Acidosis from any one of various causes (diabetic ketoacidosis, lactic acidosis, etc.); Presence of insufficient corticosteroids (Addison's disease). As in hypokalemia, there may be a poor correlation between serum potassium levels and the typical ECG changes.

The correct answer is C

Explanation

• In severe aortic stenosis , the left ventricle functions at the steep portion of the pressure-volume curve.

• In aortic stenosis, there is pressure overload leading to concentric hypertrophy of the left ventricle. This causes increased contractility and decreased compliance of the chamber. More pressure is thus exerted to eject the same volume of blood. The pressure–volume curve therefore shifts to the left.

• In aortic and mitral regurgitation, volume overload occurs leading to a dilated left ventricle. This causes decreased contractility and increased compliance and shifts the pressure–volume curve to the right.
  
• In mitral and tricuspid stenosis, there is pressure overload in the left atrium and not the left ventricle. There would thus be no change in the pressure–volume curve of the left ventricle. MAP = diastolic blood pressure + [(systolic BP – diastolic BP)/3]. Even in the presence of heart failure or hypertensive encephalopathy, a controlled reduction, to a level of about 150/90 mmHg, over a period of 24–36 hours is ideal. In most patients, blood pressure can be brought down with bed rest and oral medication.
• Intravenous labetalol (2 mg/min to a maximum of 200 mg), intravenous glyceryl trinitrate (0.6–1.2 mg/h), intravenous sodium nitroprusside (0.3–1.0 mg/kg per min) or intramuscular hydralazine (5 or 10 mg repeated at half-hourly intervals) are all effective but require close monitoring.

The correct answer is E.

Most RNA viruses (eg, poliovirus) replicate in the cytoplasm and therefore can replicate in enucleated cells. Poliovirus belongs to the family Picornaviridae. These viruses are nonenveloped and have an icosahedral nucleocapsid that contains positive-sense RNA.
The exception to the rule regarding RNA viruses is the family Orthomyxoviridae, the influenza viruses (choice C). Orthomyxoviruses undergo transcription and RNA replication in the nucleus of the host cell because they need to cannibalize the capped 5' termini of cellular RNAs for use as primers for viral mRNA transcription.

For most DNA viruses, transcription and DNA replication occur in the nucleus of the host cell. The exception to this observation is the family Poxviridae, which carries out its replication in the cytoplasm. Poxviridae includes variola virus, vaccinia virus, molluscum contagiosum, and orf virus.

Adenoviruses (choice A) are nonenveloped and have an icosahedral nucleocapsid that contains a double-stranded linear DNA genome.

Cytomegalovirus (choice B) is a member of family Herpesviridae. It is an enveloped virus with an icosahedral nucleocapsid that contains a double-stranded linear DNA genome.

JC virus (choice D) belongs to family Papovaviridae. It is nonenveloped and has an icosahedral nucleocapsid that contains a double-stranded circular DNA genome.

Answer: E

Review:

	CD20	CD5	CD10	CD23	CD43	CIg	SIg	Cyclin D1
CLL	+	++	-	++	++	5% +	+	+/-
LPL	++	-	-	-	+/-	+	++	-
MCL	++	++	-	-	++	-	++	++
MZL	++	-	-	+/-	+/-	+/-	++	-
FCL	++	-	60% +	+/-	-	-	++	-

Stetler-Stevenson, M., Braylan, R.C. Flow cytometric analysis of lymphomas and lymphoproliferative disorders. Seminars in hematology. 2001, 38:11-123

The correct answer is C
Explanation

Kallmann's syndrome which is an isolated gonadotropin (LH and FSH) deficiency occurs in both a sporadic and familial form and although uncommon i.e. 1 in 10,000 men, it is second to Klinefelter's syndrome as a cause of hypogonadism. The syndrome is often associated with anosmia, congenital deafness, hair lip, cleft palate, craniofacial asymmetry, renal abnormalities, color blindness. The hypothalamic hormone GnRH appears to be absent.

If exogenous GnRH is administered, both LH and FSH are released from the pituitary. Except for the gonadotropin deficiency, anterior pituitary function is intact. The syndrome appears to be inherited either as an autosomal recessive trait or an autosomal dominant trait with incomplete penetrance.

The differential diagnosis should include delayed puberty. Kallmann's syndrome distinguishing features though are testes less than 2 cm in diameter and positive family history with the presence of anosmia. "Fertile eunuch" are individuals with isolated LH deficiency.

They have eunuchoid proportions with variable degrees of virilization and gynecomastia. They characteristically have large testes and semen containing a few sperm. Plasma FSH levels are normal but both the serum LH and testosterone concentrations are low normal.

The cause appears to be a partial gonadotropin deficiency in which there is adequate LH to stimulate testosterone production with resultant spermatogenesis but insufficient testosterone to promote virilization. In isolated FSH deficiency which is rare, patient's are normally virilized and have normal testicular size and baseline levels of LH and testosterone.

Sperm counts range from O to a few sperm. Serum FSH levels are low and do not respond to GnRH stimulation. Congenital hypogonadotropic syndromes are associated with secondary hypogonadism and a multitude of other somatic findings. Prader-Willi syndrome is characterized by hypogonadism, hypomentia, hypotonia at birth and obesity. Laurence-Moon-Bardet-Biedel syndrome is an autosomal recessive trait characterized by mental retardation, retinitis pigmentosa, polydactyly and hypogonadism. These syndromes are felt to be due to a defect in hypothalamic deficiency of GnRH.

Patients with hypogonadism should be examined with respect to anosmia because such a combination suggests the diagnosis of Kallmann's syndrome. The selection of a therapeutic method should be strictly individual bearing in mind a degree of hypoplasia and the presence of cryptorchism. In the combination of Kallmann's syndrome with cryptorchism CG therapy results in the elimination of cryptorchism without surgery in most patients.

Chorionic gonadotropin should be administered in combination with androgens in marked testicular hypoplasia in any period at the reproductive age; later on it can be only chorionic gonadotropin. Correct diagnosis and adequate therapy lead to sex and social rehabilitation of patients with Kallmann's syndrome decreasing the number of sterile men.

The correct answer is E
Explanation

Craniopharyngioma is the most common brain neoplasm of nonglial origin and the most common brain tumor associated with hypothalamic-pituitary dysfunction and sexual infantilism.

Clinical manifestations include headache, visual disturbances, short stature, symptoms of diabetes insipidus, and weakness of one or more limbs. Physical findings include visual defects (including bilateral temporal field deficits), optic atrophy or papilledema, and signs of GH deficiency, delayed puberty, and hypothyroidism. Although only a few patients seek evaluation because of short stature, most are below the mean in height and height velocity at the time of diagnosis.

Laboratory evaluation often indicates deficiencies in one or more pituitary hormones, including gonadotropins, GH, thyrotropin (thyroid-stimulating hormone [TSH]), corticotropin, and vasopressin (AVP). The plasma level of prolactin may be normal or increased. Radiographic examination often shows retarded bone age.

Tags: Endocrinology, MCQS, Craniopharyngioma

The correct answer is C
Explanation

Medullary thyroid cancer is a malignancy of the thyroid parafollicular cells. Thyroid parafollicular cells normally produce the hormone calcitonin. A malignancy of these cells, therefore, can also produce calcitonin. Assay of calcitonin is a very good diagnostic test for medullary carcinoma of the thyroid. Thyroid stimulating hormone (choice a) is an anterior pituitary hormone and is not produced by the thyroid gland at all.

A tumor of the parafollicular cells would not produce thyroid stimulating hormone. Thyroid hormone is not produced by the parafollicular cells, but rather by the follicular cells. A tumor of the parafollicular cells would not produce thyroid hormone.Antidiuretic hormone is normally produced by the hypothalamus and released by the posterior pituitary. ADH can be seen other types of tumors as ectopic hormone production and produce a paraneoplastic syndrome. However, a tumor of the parafollicular cells would not produce antidiuretic hormone To understand which mechanism is responsible for uptake in medullary thyroid carcinoma one needs to explore the subject further.

This type of carcinoma arises from the neoplastic transformation of the C-cells of the thyroid. These cells are derived from the neural crest embryologically rather than the foregut endoderm as is the remainder of the thyroid. The tumor affects the upper third of the lateral lobe of the thyroid since this is where most of the C-cells are concentrated. Medullary carcinoma accounts for 10%% of thyroid neoplasms. It occurs sporadically in 80-90%% and is familial in 10-20% of cases. The familial type is transmitted as autosomal dominant and is associated with the MEN II or MEN III syndrome.

Thyroid function tests are usually normal. Numerous hormones are produced by this neoplasm and these include calcitonin, ketocalcin, L-Dopa decarboxylase, carcinoembryonic antigen, serotonin, prostaglandins, ACTH, histaminase and substance p. It should be noted that the first four hormones are also secreted by normal C cells. Elevated calcitonin is related to the secretory diarrhea which occurs in 30% of cases.

This particular hormone is the only sensitive indicator for the presence of tumor because it is the only one showing response to provocative or suppressive stimuli. Elevated histaminase correlates well with metastasis

The correct answer is D

Explanation The thermoregulatory control of human skin blood flow is vital to the maintenance of normal body temperatures during challenges to thermal homeostasis. Sympathetic neural control of skin blood flow includes the noradrenergic vasoconstrictor system and a sympathetic active vasodilator system, the latter of which is responsible for 80% to 90% of the substantial cutaneous vasodilation that occurs with whole body heat stress. With body heating, the magnitude of skin vasodilation is striking: skin blood flow can reach 6 to 8 L/min during hyperthermia.

The correct answer is D

Explanation

Wenckebach phenomenon is a form of incomplete atrio-ventricular heart block in which there is progressive lengthening of conduction time in cardiac tissue with P-R interval increasing until there is not a ventricular response.



This is followed by a conducted beat with a short P-R interval, and then the cycle repeats itself. This occurs frequently after an inferior myocardial infarction and tends to be self-limiting.

The correct answer is B

Explanation

With aortic stenosis there is a systolic ejection murmur that is heard loudest at the second right intercostal space (the aortic area). A systolic ejection murmur is also seen with pulmonic stenosis, however this is best heard in the second left intercostal space.


Atrial fibrillation is common in mitral stenosis. It is also seen in mitral regurgitation, however, less commonly than with mitral stenosis.


Aortic stenosis typically is not associated with atrial fibrillation.The pulse pressure is the difference between systolic and diastolic pressure. An increased pulse pressure is seen with aortic regurgitation.


It manifests itself with various signs: Quincke's sign, Duroziez's sign and a 'water hammer pulse'. diastolic murmur is heard with several different valvular conditions, including aortic regurgitation.


A diastolic murmer is not heard with aortic stenosis. The murmur of aortic stenosis is heard during systole.The symptoms of aortic stenosis include left ventricular failure (syncope and angina are also symptoms).