Techniques used for collecting biopsy sample include: （ ）
C:Deep organ puncture
E:All the other options are included
答案: 【All the other options are included】
A 17-year-old boy infected with hepatitis A experiences mild nausea for about 1 week and develops very mild scleral icterus. On physical examination, he has minimal right upper quadrant tenderness. Laboratory findings include a serum AST of 68U/L, ALT 75U/L, and total bilirubin 5.l mg/dL. The increase in this patient's serum enzyme levels most likely results from which of the following changes in the hepatocytes?
A:Dispersion of ribosomes
B:Autophagy by lysosomes
C:Swelling of the mitochondria
D:Clumping of nuclear chromatin
E:Defects in the cell membrane
答案: 【Defects in the cell membrane】
An experiment analyzes cells for enzyme activity associated with sustained cellular proliferation. Which of the following cells is most likely to have the highest telomerase activity?
In a clinical trial, a chemotherapeutic agent is given to patients with breast cancer metastases. Samples of the cancer cells are obtained and assessed for the presence of death of tumor cells by apoptosis. Mutational inactivation of which of the following products is most likely to render tumor cells resistant to the effects of such an agent?
答案: 【NF- kappaB】
A 22-year-old woman has a congenital anemia that has required multiple transfusions of RBCs for many years. On physical examination, she now has no significant findings; however, liver function tests show reduced serum albumin. Which of the following findings would most likely appear in a liver biopsy specimen?
A:Steatosis in hepatocytes
B:Bilirubin in canaliculi
C:Glycogen in hepatocytes
D:Amyloid in portal triads
E:Hemosiderin in hepatocytes
答案: 【Hemosiderin in hepatocytes】
A 69-year-old man has had difficulty with urination, including hesitancy and frequency, for the past 5 years. A digital rectal examination reveals that the prostate gland is palpably enlarged to about twice normal size. A transurethral resection of the prostate is performed, and the microscopic appearance of the prostate “chips” obtained is that of nodules of glands with intervening stroma. Which of the following pathologic processes has most likely occurred in the prostate?
A 33-year-old woman has had increasing lethargy and decreased urine output for the past week. Laboratory studies show serum creatinine level of 4.3mg/dL and urea nitrogen level of 40mg/dL. A renal biopsy is performed, and the specimen is examined using electron microscopy. Which of the following morphologic changes most likely suggests a diagnosis of acute tubular necrosis?
B:Plasma membrane blebs
答案: 【Nuclear fragmentation】
A 63-year-old man has a 2-year history of worsening congestive heart failure. An echocardiogram shows mitral stenosis with left atrial dilation. A thrombus is present in the left atrium. One month later, he experiences left flank pain and notes hematuria. Laboratory testing shows elevated serum AST. Which of the following patterns of tissue injury is most likely to be present?
答案: 【Coagulative necrosis】
On a routine visit to the physician, an otherwise healthy 51-year-old man has a blood pressure of 150/95 mm Hg. If the patient's hypertension remains untreated for years, Which of the following cellular changes is unlikely to occur in myocardium?
In an experiment, cells are subjected to radiant energy in the form of x-rays. This results in cell injury caused by hydrolysis of water. Which of the following cellular enzymes does not protect cells from this damage?
答案: 【Phospholipase;Endonuclease;Lactate dehydrogenase;Protease】
A 68-year-old woman suddenly lost consciousness and, on awakening 1 hour later, she could not speak or move her right arm and leg. Two months later, a head CT scan showed a large cystic area in the left parietal lobe. Which of the following pathologic processes has most likely occurred in the brain?
答案: 【Liquefactive necrosis】
A 60-year-old woman developed chest pain that persisted for 4 hours. A radiographic imaging procedure showed an apparent myocardial infarction involving a 3×4 cm area of the posterior left ventricular free wall. Laboratory findings showed serum creatine kinase of 600 U/L. The patient received both anti-arrhythmic and pressor agents to treat the decreased cardiac output while in the hospital. Which of the following pathologic findings would most likely be seen in the left ventricle l month later?
答案: 【Fibrous scar】
An experiment infects one group of test animals with viral hepatitis. Two months later, complete recovery of the normal liver architecture is observed when the livers from these animals are examined microscopically. A second test group is infected with bacterial organisms, and after the same period of time, fibrous scars from resolving abscesses are seen microscopically in the livers. Which of the following factors best explains the different outcomes for the two test groups?
A:Nature of the etiologic agent
B:Extent of liver cell injury
C:Injury to the connective tissue framework
D:Location of the lesion
E:Extent of damage to the bile ducts
答案: 【Injury to the connective tissue framework】
A 23-year-old woman receiving corticosteroid therapy for an autoimmune disease has an abscess on her upper outer right arm. She undergoes minor surgery to incise and drain the abscess, but the wound heals poorly over the next month. Which of the following aspects of wound healing is most likely to be deficient in this patient?
B:Fibroblast growth factor elaboration
D:Serine proteinase production
答案: 【Collagen deposition】
A cesarean section is performed on a 20-year-old woman to deliver a term infant, and the lower abdominal incision is sutured. The sutures are removed l week later. Which of the following statements best describes the wound site at the time of suture removal?
A:Granulation tissue is still present
B:Collagen degradation exceeds synthesis
C:Wound strength is 80% of normal tissue
D:Type IV collagen predominates
E:No more wound strength will be gained
答案: 【Granulation tissue is still present】
A 40-year-old man underwent laparotomy for a perforated sigmoid colon diverticulum. A wound infection complicated the postoperative course, and surgical wound dehiscence occurred. Primary closure was no longer possible, and the wound "granulated in." Six weeks later, the wound is only l0% of its original size. Which of the following processes best accounts for the observed decrease in wound size over the past 6 weeks?
A:Increase in synthesis of collagen
C:Inhibition of metalloproteinases
D:Resolution of subcutaneous edema
E:Elaboration of adhesive glycoproteins
答案: 【Myofibroblast contraction】
In an experiment involving observations on wound healing, researchers noted that intracytoplasmic cytoskeletal elements, including actin, interact with the extracellular matrix to promote cell attachment and migration in wound healing. Which of the following substances is most likely responsible for such interaction between the cytoskeleton and the extracellular matrix?
A:Epidermal growth factor
D:Platelet-derived growth factor
E:Type IV collagen
F:Vascular endothelial growth factor
In an experiment, release of epidermal growth factor into an area of denuded skin causes mitogenic stimulation of the skin epithelial cells. Which of the following proteins is most likely to be involved in transducing the mitogenic signal from the epidermal cell membrane to the nucleus?
答案: 【RAS proteins】
An experiment analyzes factors involved in the cell cycle during growth factor-induced cellular regeneration in a tissue culture. Cyclin B synthesis is induced; the cyclin B then binds and activates cyclin-dependent kinase 1 (CDK1). The active kinase produced by this process is most likely to control progression in which of the following phases of the cell cycle?
A:G0 to G1
B:G1 to S
C:S to G2
D:G2 to M
E:M to G1
答案: 【G2 to M】
An experiment is conducted involving cellular aspects of wound healing. Components of the extracellular matrix are analyzed to determine their sites of production and their binding patterns to other tissue components.Which of the following molecules synthesized by fibroblasts can best bind to cellular integrins and extracellular collagen and attach epidermal basal cells to basement membrane?
In an experiment, surgical incisions are made in a study group of laboratory rats. Observations about the wounds are recorded over a 2-week period using a variety of chemical mediators. Which of the following steps in the inflammatory-repair response is impossible affected by neutralization of transforming growth factor-β?
B:Increase in vascular permeability
C:Production of collagen
D:Chemotaxis of lymphocytes
E:Migration of epithelial cells
答案: 【Leukocyte extravasation;Increase in vascular permeability;Chemotaxis of lymphocytes;Migration of epithelial cells】