WebPath 6 Atherosclerosis and Thrombosis
A 66-year-old man with Parkinson disease develops pleuritic chest pain. On exam, he has guarding over the right lower lung with dullness to percussion. A chest CT scan shows a focal, wedge-shaped pleural baesed area of hemorrhage in the right lower lobe. Which of the following is the most likely cause for his pulmonary lesion? A Embolism B Atherosclerosis C Vasculitis D Arteriolosclerosis E Thrombosis
(A) A pulmonary infarction is described. A thromboembolus from the venous circulation, usually arising in large leg veins, has lodged in a peripheral pulmonary arterial branch. The bronchial arterial supply to the lung does not provide enough oxygenation to prevent infarction, but does provide blood to make the infarct hemorrhagic. His neurodegenerative disorder with reduced movement is a risk for phlebothrombosis.
A 57-year-old man has had blood pressure measurements in the range of 160/95 to 180/110 mm Hg for many years. He has taken no medications. A renal scan reveals kidneys of normal size for age. These findings with benign nephrosclerosis are most likely to occur with which of the following vascular changes? A Hyaline arteriolosclerosis B Monckeberg's medial calcific sclerosis C Complex calcified atherosclerosis D Arterial mural thrombosis E Hyperplastic arteriolosclerosis
(A) Hyaline arteriolosclerosis is a feature of long-standing hypertension and is part of benign nephrosclerosis which may go on for many years with no complications. The small arterioles are thickened with pink (hyaline) proteinaceous deposits.
A 44-year-old African-American man has had elevated blood pressure for years which has not been treated. He now has severe headaches. On physical examination his blood pressure is 275/150 mm Hg. Laboratory studies show Hgb 13.8 g/dL, serum glucose 76 mg/dL, and creatinine 3.5 mg/dL. These findings are most likely to be associated with which of the following pathologic lesions involving his kidneys? A Hyperplastic arteriolosclerosis B Hyaline arteriolosclerosis C Monckeberg medial calcific sclerosis D Atherosclerosis E Thrombophlebitis
(A) Hyperplastic arteriolosclerosis is seen in the setting of malignant hypertension, and renal failure is common.
A 58-year-old woman has the sudden onset of severe dyspnea with chest pain and diaphoresis. A chest CT scan shows areas of decreased attenuation within the main pulmonary arteries. Her D-dimer assay is elevated. Her acute event is most likely to be a consequence of which of the following? A Placement of a hip prosthesis B Marked thrombocytopenia C Chronic alcoholism D Infection with the human immunodeficiency virus E Rheumatoid arthritis
(A) Immobilization is a major risk for the development of venous thrombosis and subsequent pulmonary embolization (the areas of diminished attenuation). Immobilization occurs following surgery. The postoperative goal: get the patient mobile as soon as possible, and meanwhile employ methods to reduce the risk for thrombosis.
n an experiment, a glass bead is embolized to a branch of the renal artery. A day later there is a focal area in which the renal parenchymal cells in the distribution of the occluded artery show karyolysis and karyorrhexis. The outlines of the cells are still visible, but the nuclei have lost basophilic staining and the cytoplasm is eosinophilic but pale. Which of the following types of cellular necrosis is most likely present? A Caseous B Coagulative C Fatty D Gangrenous E Liquefactive
(B) A typical ischemic infarction with coagulative necrosis is described. Coagulative necrosis is most likely to occur in solid internal organs with high metabolic demands.
A study of atherogenesis is performed. There is a propensity for atheromas to form at muscular arterial branch points, such as the carotid and aortic bifurcations. Which of the following events in the arteries at these locations is most likely to initiate atherogenesis? A Collagen synthesis B Endothelial dysfunction C Lactic acidosis D Cholesterol breakdown E Hypoxemia
(B) A variety of stressors may affect endothelial cells, including the shear stress from turbulent flow at arterial branch points. Endothelial dysfunction is the initiating event that allows insudation of lipids to promote atherogenesis.
A 54-year-old man with diabetes mellitus has had 3 urinary tract infections during the past year. He now sees the physician for an ulceration on his right big toe which has not healed in 2 months. Laboratory studies on each of his doctor visits over the past year show blood glucose levels below 110 mg/dL. This situation could be best explained by which of the following laboratory findings? A Elevated hemoglobin A1C level B Increased urine ketones C Elevated serum osmolarity D Decreased plasma insulin E Elevated titer of anti-insulin antibodies
(A) Out-of-control diabetes over time can be better detected because the glycosylated RBCs will persist for months and the Hgb A1C increased. Single glucose values reflect the past few hours. His problems developed over years.
A 57-year-old woman has had episodes of abdominal pain following meals for the past year. Her BMI is 31. She has hypertension. Her total serum cholesterol is increased. Which of the following types of blood vessel is the most likely location for the pathologic abnormality causing her pain? A Artery B Arteriole C Capillary D Venule E Vein
(A) She has abdominal angina from vascular insufficiency. She has multiple risk factors for atherosclerosis. Atherosclerosis occurs in muscular arteries, because the level of blood pressure in arteries predisposes to endothelial dysfunction.
A 63-year-old man has had increasing exercise intolerance for the past 6 years so that he now becomes short of breath upon climbing a single flight of stairs. Laboratory studies have shown fasting blood glucose measurements from 145 to 210 mg/dL for the past 25 years, but he has not sought medical treatment. If he dies suddenly, which of the following is most likely to be the immediate cause of death? A Myocardial infarction B Nodular glomerulosclerosis C Cerebral hemorrhage D Hyperosmolar coma E Right lower leg gangrene
(A) This is the most common cause of death in persons with diabetes mellitus, because of the high prevalence of advanced coronary atherosclerosis.
An autopsy study reveals that evidence for atheroma formation can begin even in children. The gross appearances of the aortas are recorded and compared with microscopic findings of atheroma formation. Which of the following is most likely to be the first visible gross evidence for the formation of an atheroma? A Thrombus B Fatty streak C Calcification D Hemorrhage E Exudate F Ulceration
(B) A fatty streak on the arterial intimal surface is the first grossly visible sign of atheroma formation. It is benign and reversible, but it may be the precursor to more severe plaques.
Following a meal, lipids are digested and absorbed. Lipids collect within enterocytes. Which of the following chemical components of the blood is mainly responsible for transporting exogenous (dietary) triglyceride from the intestine to the liver? A Apoprotein B Chylomicron C Lipoprotein lipase D Oxidized low density lipoprotein E High density lipoprotein
(B) Chylomicrons formed in intestinal epithelial cells contain apoproteins, triglyceride and cholesterol.
A 30-year-old man goes to his physician for a routine health checkup. On physical examination there are no abnormal findings. Laboratory test findings include serum glucose 80 mg/dL, hemoglobin A1C 4%, total cholesterol 240 mg/dL, LDL cholesterol 180 mg/dL, and HDL cholesterol 20 mg/dL. Through which of the following mechanisms is endothelial vascular injury in this patient most likely to occur? A Accumulation of sorbitol B Insudation of lipid C Inflammation with neutrophils D Deposition of immunoglobulins E Activation of complement
(B) He has hypercholesterolemia with more of the 'bad' LDL cholesterol that can become oxidized and taken up by modified arterial wall LDL receptors. The lipid collects in macrophages that transform to foam cells. These foam cells accumulate and becomes a lipid lesion--the precursor to more serious atheromatous plaques.
A 60-year-old woman has become increasingly obtunded over the past day. She was found by her daughter in a stuporous condition and brought to the emergency department. On physical examination, she has poor skin turgor. She is afebrile. Her vital signs reveal a blood pressure of 90/40 mm Hg, respirations 15 and shallow, pulse 95, and temperature 36°C. Laboratory studies show a hemoglobin A1C of 10%. Her serum electrolytes show sodium 144 mmol/L, potassium 5 mmol/L, chloride 95 mmol/L, CO2 22 mmol/L, and glucose 940 mg/dL. Which of the following is the most likely diagnosis? A Insulin overdose B Hyperosmolar coma C Hyperlipidemia D Ketoacidosis E Overeating
(B) This is an extremely elevated serum glucose that would increase the serum osmolality markedly.
An autopsy study is conducted involving the gross appearance of the aorta of adults ranging in age from 60 to 90. In some of these patients, the aorta demonstrates atheromatous plaques covering from 70 to 95% of the intimal surface area, mainly in the abdominal portion, with ulceration and calcification. Which of the following contributing causes of death are these patients most likely to have? A Hyperparathyroidism B Hypertension C Marfan syndrome D Thrombophlebitis E Vasculitis F Colonic adenocarcinoma G Systemic lupus erythematosus
(B) Hypertension is a risk factor that accelerates atheromatous plaque formation.
A 73-year-old woman who exercises regularly falls down the stairs and injures her right hip. A radiograph is taken of the pelvis. There is no fracture but the radiograph reveals calcification of the small muscular arteries lateral to her uterus. What is the probable vascular lesion which accounts for this calcification? A Ulcerative atherosclerosis B Calcific medial sclerosis C Metastatic calcification D Trauma E Dystrophic calcification
(B) Monckeberg calcific medial sclerosis is a benign, incidental finding most often seen in the elderly. Small arteries in pelvis, breast, neck, and extremities are typically involved. The vascular lumen is not compromised.
62-year-old man has experienced substernal chest pain upon exertion with increasing frequency over the past 6 months. An electrocardiogram shows features consistent with ischemic heart disease. He has a total serum cholesterol of 262 mg/dL. By angiography, there is 75% narrowing of coronary arteries. In which of the following locations is a mural thrombus most likely to occur in this man? A Left atrium B Left ventricle C Right atrium D Right ventricle E Aorta F Vena cava
(B) The left ventricle is the major user of oxygen and nutrients and requires a good blood supply. A complication of ischemic heart disease with infarction is development of overlying mural thrombus. Such mural thrombi are likely to result from damage to the left ventricle from ischemic heart disease, either acutely with an underlying myocardial infarction, or with a left ventricular aneurysm formed following resolution of a large myocardial infarction
A 68-year-old woman has survived multiple episodes of pulmonary thromboembolism during the past three months. On physical examination there are no abnormal findings. Which of the following is the most likely underlying condition leading to this patient's recurrent pulmonary thromboembolism? A Micronodular cirrhosis of the liver B Adenocarcinoma of the pancreas C Thrombocytopenia D Familial hypercholesterolemia E Mitral valve endocarditis F Type II diabetes mellitus
(B) The recurrent episodes suggest a hypercoagulable state, and carcinomas can do this (Trousseau syndrome) by releasing substances that act as thromboplastins.
A longitudinal study is conducted to detect serum markers that predict risk for death from acute coronary syndromes. A marker is identified that is synthesized and released from the liver in response to formation of cytokines in atheromatous plaques. This marker increases endothelial adhesiveness to platelets. What is this marker most likely to be? A Prostacyclin B Immunoglobulin G C C-reative protein D Alpha-1-antitrypsin E Acetoacetate
(C) An increased CRP predicts a greater likelihood for adverse events from atherogenesis. One benefit of 'statin' drugs is their CRP lowering effect.
A study of pathologic findings in the islets of Langerhans is performed. It is observed that insulitis may occur in the islets. The inflammatory infiltrate is predominantly composed of T lymphocytes. Which of the following is most likely to occur as a consequence of insulitis? A Neoplasia B Malabsorption C Ketoacidosis D Obesity E Sepsis
(C) An insulitis is seen with type I diabetes mellitus. Actually, it is rare to see it because by the time the patients present with overt diabetes mellitus, the islets are long gone.
A 63-year-old man has had insulin dependent diabetes mellitus for over two decades. The degree of control of his disease is indicated by the laboratory finding of hemoglobin A1C 10.1%. He has noted episodes of abdominal pain following meals. These episodes have worsened over the past year. On physical examination, there are no masses and no organomegaly of the abdomen, and he has no tenderness to palpation. Which of the following pathologic findings is most likely to be present in this man? A Ruptured aortic aneurysm B Hepatic infarction C Mesenteric artery occlusion D Acute pancreatitis E Chronic renal failure
(C) He has 'abdominal angina' from diminished blood flow to the bowel as a consequence of severe atherosclerosis. Persons with diabetes mellitus may have this finding, because all branches of major arteries to the bowel are affected by atherosclerosis.
At autopsy, the kidneys of a 44-year-old woman who died suddenly are found to be of normal size. Their surfaces appear finely granular. There are small hemorrhages noted. The cortices appear pale. Microscopically, many small renal arteries and arterioles demonstrate concentric intimal thickening with marked luminal narrowing. These findings are most likely to be present as a result of which of the following underlying diseases? A Amyloidosis B Systemic lupus erythematosus C Scleroderma D Rheumatoid arthritis E Viral hepatitis F Diabetes mellitus
(C) Hyperplastic arteriolosclerosis is typically seen in association with severe hypertension, which can complicate prior 'essential' hypertension or occur with progressive systemic sclerosis (scleroderma).
A 10-year-old previously healthy child has been noted by her parents to be constantly thirsty. She is consuming large amounts of soft drinks. She is urinating often. Her diet and exercise patterns have not changed, except for an increased appetite, yet she appears cachectic and has lost 7 kg over the past 4 months. On physical examination there are no abnormal findings, other than peripheral muscle wasting and weakness. Which of the following laboratory findings would you most strongly suspect is present in this girl? A Increased blood insulin B Decreased blood glucagon C Ketonuria D Increased serum osmolality E Decreased plasma H+ (alkalosis) F Decreased plasma cortisol
(C) Ketonuria is typical for type I diabetes mellitus. The findings of polydipsia, polyuria, and polyphagia are present in this case. The absolute decrease in insuling leads to a catabolic state, with underutilization of carbohydrates, and lipolysis with metabolism of fatty acids to produce ketone bodies.
A 49-year-old woman has experienced marked pain in her lower extremities on ambulation more than 300 meters for the past 5 months. On physical examination, her lower extremities are cool and pale, without swelling or erythema. No dorsalis pedis or posterior tibial pulses are palpable. Her body mass index is 32. She is a smoker. Which of the following abnormalities of the vasculature is most likely to account for these findings? A Lymphatic obstruction B Arteriolosclerosis C Atherosclerosis D Medial calcific sclerosis E Venous thrombosis
(C) She has claudication from severe peripheral arterial atherosclerosis, most likely from the iliac arteries down. Her major risk factor is obesity that promotes insulin resistance and diabetes mellitus that leads to atherosclerosis.
A 66-year-old woman has the sudden loss of movement on part of the left side of her body. She has smoked a pack of cigarettes a day for the past 45 years. She has vital signs including T 37.1°C, P 80/minute, RR 16/minute, and BP 160/100 mm Hg. A cerebral angiogram reveals occlusion of a branch of her middle cerebral artery. Laboratory findings include a hemoglobin A1C of 9%. Which of the following components of blood lipids is most important in contributing to her disease? A Chylomicrons B Lipoprotein lipase C Oxidized LDL D VLDL E HDL cholesterol
(C) She has had a 'stroke' which is most often a consequence of cerebral atherosclerosis or embolic disease from the heart as a consequence of ischemic heart disease from atherosclerosis. LDL brings cholesterol to arterial walls, and when increased LDL is present or when there is hypertension, smoking, and diabetes, there is more degradation of LDL to oxidized LDL which is taken up into arterial walls via scavenger receptors in macrophages to help form atheromas.
A study is performed involving persons who have a history of diabetes mellitus type 1 or type 2. These patients are found to have cellular injury that results from glycosylation end products and from sorbitol accumulation within cells. The same patients are also shown to have ischemic tissue damage from accelerated and advanced atherosclerosis. Which of the following complications is most likely to result from atherosclerosis in these patients? A Hepatic failure B Impotence C Stroke D Cataracts E Retinopathy
(C) Stroke from cerebral atherosclerosis or from embolization of mural thrombi from a heart involved with ischemic injury as a consequence of atherosclerosis....
A 54-year-old previously healthy woman is hospitalized for pneumonia. On the 10th hospital day she is found to have swelling and tenderness of her right leg, which has developed over the past 48 hours. Raising the leg elicits pain. An ultrasound examination reveals findings suggestive of femoral vein thrombosis. Which of the following conditions is most likely to have contributed the most to the appearance of these findings? A Trousseau syndrome B Protein C deficiency C Immobilization D Pregnancy E Chronic alcohol abuse F Hypertension
(C) The immobilization while in hopsital would predispose to thrombosis of leg veins. This is the most common cause for deep venous thrombosis.
A 61-year-old man has the sudden onset of severe chest pain. Vital signs include T 37°C, P 102/minute, RR 20/minute, and BP 80/40 mm Hg. An electrocardiogram demonstrates changes that are consistent with myocardial ischemia involving the left lateral ventricular free wall. He is given thrombolytic therapy with tissue plasminogen activator (tPA) 3 hours after the onset of chest pain. However his serum creatinine kinase is found to be 450 U/L 3 hours after this therapy. Which of the following cellular events has most likely occurred? A Cellular regeneration B Drug-induced necrosis C Reperfusion injury D Increased synthesis of creatine kinase E Myofiber atrophy
(C) The restoration of blood flow is helpful if the existing cell damage is not great, so further damage can be prevented. However, the reperfusion of damaged cells results in generation of oxygen free radicals to produce a reperfusion injury.
A 25-year-old man experiences chest pain on exercise when he attempts to climb three flights of stairs. This pain is relieved by sublingual nitroglycerin. He is 178 cm tall and weighs 101 kg. His blood pressure is 130/85 mm Hg. Laboratory studies show a total serum cholesterol of 550 mg/dL with an HDL cholesterol component of 25 mg/dL. The blood glucose is 120 mg/dL. He is worried about these findings because his brother died of a myocardial infarction at age 34. Which of the following conditions is this man most likely to have? A Diabetes mellitus, type II B Malignant hypertension C Familial hypercholesterolemia D Cushing syndrome E Morbid obesity
(C) The very high cholesterol with symptoms of coronary artery disease at such a young age, coupled with the family history, are all consistent with familial hypercholesterolemia. In most persons with hypercholessterolemia from multifactorial causes, including diet and exercise patterns, the cholesterol rarely exceeds 400 mg/dL.
A 72-year-old man suffered a myocardial infarction involving half the left ventricular free wall 3 months ago. He now has increasing dyspnea and orthopnea. On echocardiography his ejection fraction is 29%. On examination he has poor capillary filling in hands and feet. A chest x-ray shows pulmonary edema. Which of the following laboratory test analytes is most likely to be increased in this man at this point in time? A Sodium B Creatine kinase C Natriuretic peptide D Hematocrit E Sedimentation rate
(C) With congestive heart failure, there is volume overload that triggers an increase in natriuretic peptide, typically measured as the b-type (BNP). This hormone normally leads to natriuresis, diuresis, and vasodilation, lessening the strain on the myocardium.
A 57-year-old woman has experienced episodes of altered mental status for the past month. On physical examination, she has bilateral carotid artery bruits. She is given folic acid supplementation. Which of the following laboratory test findings is she most likely to have? A Factor V Leiden mutation B Factor VIII deficiency C Increased carcinoembryonic antigen D Homocysteinemia E Increased HDL cholesterol
(D) An elevated plasma homocysteine level is a risk for atherosclerosis as well as thrombosis. Her findings point to transient ischemic attacks (TIAs) with risk for stroke. The carotid bruits represent arterial narrowing as the result of atherosclerosis.
A 45-year-old man feels some crushing chest pain along with numbness in his left arm after shoveling 15 cm of snow off his driveway. Three hours later he collapses and is taken to the emergency room. Which of the following laboratory tests run on a blood specimen is most useful in this situation? A Total white blood cell count B Glucose C Platelet count D Creatine kinase E Amylase
(D) Elevations in CK enzyme are going to be seen acutely with myocardial infarction beginning within 3 hours and remaining for 3 days. The total CK reflects changes in any striated muscle, and is not specific for cardiac muscle. The CK-MB fraction is most specific to myocardium.
A 44-year-old woman has a family history of heart disease. Her father and mother both developed myocardial infarction and congestive heart failure as a result of occlusive coronary atherosclerosis. A dietary modification to include consumption of which of the following is most likely to reduce her risk for ischemic heart disease? A 40% of total caloric intake as fat B Increased saturated fat C Foods with cholesterol D Cold water fish oil E Fat found in beef products F Hydrogenated oils with trans-fats
(D) Fish oils diminish arachidonic acid metabolites and reduce platelet aggregation.
A 56-year-old reports reduced exercise tolerance over the past 5 years. In the past year he has noted chest pain after ascending a flight of stairs. He smokes 2 packs of cigarettes per day. On examination he has a blood pressure of 155/95 mm Hg. His body mass index is 30. Laboratory findings include a total serum cholesterol of 245 mg/dL with an HDL cholesterol of 22 mg/dL. Which of the following vascular abnormalities is he most likely to have? A Hyperplastic arteriolosclerosis B Lymphedema C Medial calcific sclerosis D Atherosclerosis E Deep venous thrombosis F Plexiform arteriopathy
(D) He has multiple risk factors for atherosclerosis, including his weight, smoking, hypertension, and high total cholesterol with low 'good' HDL cholesterol. His findings suggest coronary artery disease with risk for an acute coronary syndrome.
A 27-year-old woman had a hemoglobin A1C of 7.9% noted during a prenatal visit. She gives birth to a 4350 gm baby at 37 weeks gestation. Just after the delivery, the baby becomes irritable and displays seizure activity. Which of the following laboratory findings is most likely to be found in the baby: A Decreased hemoglobin A1C B Increased serum osmolality C Hyperlipidemia D Hypoglycemia E Ketoacidosis
(D) Infants of diabetic mothers are at risk for hypoglycemia following delivery, because they have islet hypertrophy and hyperplasia, and the increased islet production of insulin carries into the immediate postpartum period.
A 53-year-old man has the sudden onset of chest pain. He is found to have a serum troponin I of 5 ng/mL. A year later he has reduced exercise tolerance. An echocardiogram reveals an akinetic segment of left ventricle, and he has reduced cardiac output, with an ejection fraction of 25%. He then experiences a transient ischemic attack (TIA). His serum troponin I is now <0.5 ng/mL. Thrombus formation involving which of the following locations is most likely to have put him at greatest risk for the TIA? A Cerebral vein B Vertebral artery C Superior vena cava D Left ventricle E Coronary artery F Saphenous vein
(D) Mural thrombi can form over the damaged area of ventricular wall following myocardial infarction. This can happen acutely overlying the necrotic myocardium; it can occur remotely in a ventricular aneurysm. Portions of the mural thrombus can break off and embolize via the systemic arterial circulation to places such as the cerebral circulation.
Some cells demonstrate glucose uptake from the blood regardless of the plasma insulin level. In persons who have had persistent hyperglycemia for years, cellular injury can occur. Which of the following cell types is most likely to show injury from hyperglycemia? A Cardiac myocytes B Fibroblasts C Steatocytes D Neurons E Smooth muscle cells.
(D) Neurons do not require insulin for glucose uptake. The excess glucose diffusing into the cells is shunted into the sorbitol pathway and can lead to osmotic injury, resulting in neuropathy.
A 29-year-old woman is involved in a motor vehicle accident that results in severe lacerations to her lower extremities, along with blunt abdominal trauma. In the emergency room she is noted to have cool, pallid skin. She has vital signs showing T 36.9°C, P 110/minute, RR 26/minute, and BP 70/30 mm Hg. She has decreased urine output. Which of the following laboratory findings on a blood sample from this patient is most likely to be present? A Hematocrit of 54% B Glucose of 181 mg/dL C PaO2 of 20 mm Hg D Lactic acid of 4.8 mmol/L E Troponin I of 4 ng/mL
(D) She has marked blood loss with shock. There will be vasoconstriction in skin and soft tissue in response to the hypovolemia. Decreased renal blood flow from shock may lead to acute tubular necrosis. The lack of tissue perfusion with shock leads to increased anaerobic glycolysis and lactic acidosis.
A 53-year-old woman is found on a routine physical examination to have vital signs with T 37°C, P 78/minute, RR 16/minute, and BP 165/110 mm Hg. There are no other significant findings. She has an abdominal ultrasound examination that shows the right kidney to be atrophic. Angiography reveals markedly reduced blood flow to the right renal artery from an occlusion at the orifice in the abdominal aorta. Which of the following laboratory findings is she most likely to have? A Serum sodium of 161 mmol/L B Serologic evidence of anti-cardiolipin antibody C Prothrombin time of 25 seconds D Plasma renin activity of 4.8 ng/mL/hr supine E Serum lactic acid of 5.5 mmol/L
(D) She has renal artery stenosis that is reducing renal blood flow on the right and simulating the JG cells to secrete renin to try and raise blood pressure to increase renal blood flow.
A 45-year-old man dies suddenly and unexpectedly. The immediate cause of death is found to be a hemorrhage in the right basal ganglia region. On microscopic examination his renal artery branches have concentric endothelial cell proliferation which markedly narrows the lumen, resulting in focal ischemia and hemorrhage of the renal parenchyma. An elevation in which of the following substances in his blood is most likely to be associated with these findings? A Ammonia B Calcium C Cholesterol D Renin E Troponin I F Triglyceride G C-reactive protein
(D) The findings suggest hyperplastic arteriolosclerosis, which accompanies malignant hypertension. Reduced renal blood flow increases renin, driving hypertension.
A 52-year-old man has an ulcerated area on the sole of his foot that has not healed for 2 months. He is 180 cm tall, weighs 126 kg, and has continued to gain weight gradually. He has not had any major illnesses. His blood pressure is normal. Which of the following laboratory tests performed on serum from a blood sample would be most useful in elucidating the underlying cause for his problem: A Antithrombin III B Cortisol C Creatine kinase D Glucose E Carcinoembryonic antigen
(D) The history suggests diabetes mellitus, most likely type II, and persistent hyperglycemia would confirm the diagnosis.
In a clinical study of patients with diabetes mellitus, a group of patients is found who have had blood glucose measurements ranging from 140 to 180 mg/dL for at least 10 years. Rectal biopsies from these patients now show that there is a form of osmotic cellular injury present in arterioles. This form of injury is most likely to be manifested elsewhere in the body by which of the following complications? A Cerebral infarction B Gastric adenocarcinoma C Congestive heart failure D Impotence E Pyelonephritis
(D) The hyperglycemia leads to formation of sorbitol in tissues not requiring insulin for glucose uptake, resulting in osmotic cellular injury. This can occur in small vessels, retina, kidney, and nerves. The failure of erection and ejaculation results from diabetic neuropathy.
A 34-year-old previously healthy woman notes that she has bruises form on her arms and legs with just minor trauma. Physical examination reveals areas of purpura from 1 to 3 cm in size over her trunk and extremities, but no swelling, warmth, or erythema. Peripheral pulses are all palpable and full. Her blood pressure is 110/70 mm Hg. An ultrasound examination of her lower extremities with Doppler flow measurement reveals no evidence for thrombosis. Laboratory findings include serum urea nitrogen of 16 mg/dL, LDH 300 U/L, total protein 6.9 g/dL, albumin 5.3 g/dL, alkaline phosphatase 50 U/L, AST 40 U/L, and ALT 20 U/L. Which of the following additional laboratory findings is most likely to be present in this patient? A Hyperglycemia B Hypercholesterolemia C Lactic acidosis D Thrombocytopenia E Hypoprothrombinemia F Anemia
(D) The platelets are responsible for dealing with small leaks in small vessels. Thrombocytopenia is marked by petechiae and purpura. She does not have evidence for peripheral vascular disease, since her circulation is good. Venous thrombosis should lead to swelling and tenderness.
A 52-year-old woman has experienced marked substernal, crushing chest pain for the past 3 hours. Her vital signs show T 36.9°C, P 90/minute, RR 18/minute, and BP 100/60 mm Hg. Laboratory studies include a serum creatine kinase MB fraction of 10 microgm/L as well as a serum troponin I of 4.5 ng/mL. Which of the following findings is the best evidence for the presence of a coronary arterial thrombus as the etiology for her chest pain? A Total serum cholesterol of 300 mg/dL B Large size of the infarction by scintigraphic scanning C 80% coronary occlusion by angiography D Response to thrombolytic therapy E Hemoglobin A1C of 10.1%
(D) The purpose of thrombolytic therapy is to lyse the thrombus and restore blood flow. Many acute coronary events are the result of thrombus formation on pre-existing atheromas. Low dose aspirin therapy helps prevent such events.
A 70-year-old man has noted coldness and numbness of his lower left leg, increasing over the past 4 months. He also experiences pain in this extremity when he tries walking more than the distance of half a city block. On physical examination, his dorsalis pedis, posterior tibial, and popliteal artery pulses are not palpable. Which of the following laboratory test findings is he most likely to have? A Protein S deficiency B Blood culture with Staphylococcus aureus C Decreased arterial oxygen saturation D Hyperglycemia E Hypercalcemia
(D) This is peripheral arterial vascular disease from severe atherosclerosis, which is promoted by diabetes mellitus. The absence of pulses defines this as an arterial process, as does the claudication (pain with exercise). Thrombophlebitis is a venous process and leads to swelling and pain in the leg, but not loss of pulses..
During hospitalization, a 40-year-old woman develops thrombophlebitis. She recovers and is discharged. She returns to her job as an electrician. A couple of months later, which of the following terms would best describe the process seen in a femoral vein after recovery from her thrombophlebitis: A Acute inflammation B Rupture C Embolization D Organization E Propagation
(D) Thrombi may either lyse or will organize over time, with much of the clot eventually removed and the vascular lumen restored.
A 65-year-old man has had increasing lower leg swelling along with reduced exercise tolerance for the past 5 years. He has chest pain on exertion. He has not experienced dyspnea. He has had 4 transient ischemic attacks in the past year. He has experienced abdominal pain in the past 2 months. Vital signs show T 37°C, P 82/min, RR 16/min, and BP 130/85 mm Hg. He has pitting edema to the knees bilaterally. The lower extremities have palpable pulses, no tenderness, and no erythema. An abdominal CT scan shows dilation of the abdominal aorta to 5 cm, filled with mural thrombus. Other family members have had similar problems. Which of the following underlying conditions is the most likely risk factor for his findings? A Factor V Leiden mutation B Adenocarcinoma of the colon C Multiple blunt trauma D Vasculitis E Metabolic syndrome
(E) He has findings associated with atherosclerosis, including coronary and aortic disease at least, with congestive heart failure and evidence for an aortic aneurysm. Metabolic syndrome predisposes to atherosclerosis. Some patients may eventually develop overt diabetes mellitus type 2.
A 25-year-old previously healthy primigravida is in the first trimester of pregnancy. During two successive prenatal visits, she has fasting serum glucose levels of 127 and 131 mg/dL. Prior to this pregnancy, her fasting serum glucose was 80 mg/dL. A hemoglobin A1C level is 8.1% at the last visit, at 18 weeks gestation. She feels well and has no major health problems. Which of the following problems is most likely to become apparent in the latter part of her pregnancy? A Intrauterine fetal growth retardation B Ketoacidosis C Hyperosmolar coma D Congenital anomalies E Placental insufficiency
(E) The big problem in gestational diabetes is eventual placental malfunction in later pregnancy (third trimester) with potential fetal demise.
A atudy of persons with essential hypertension is performed. They have blood pressures in the range of 140/90 to 160/100 mm Hg. Laboratory studies show normal serum electrolyte values. Which of the following physiologic abnormalities is most likely to account for their hypertension? A Hyperreninemia B Hyperaldosteronism C Decreased natriuretic peptide D Decreased angiotensin converting enzyem E Sodium retention F Catecholamine excess
(E) The causes for essential hypertension are obscure. The 'set point' for sodium diuresis is probably increased at a higher blood pressure in affected persons. Diuretics that promotes natriuresis are effective in treating essential hypertension.
