501. Metastasis
A. unequivocally proves malignancy.
B. is proven by lymph node enlargement adjacent to a tumour.
C. of breast cancer is usually to supraclavicular nodes.
D. is the most common presentation of melanoma.
E. all of the above

502. Regarding the Clostridium species
A. wound infections caused by C. perfringens generally occur 7-10 days following surgery.
B. C. tetani produces an endotoxin which causes muscle spasm.
C. the toxin of C. botulinum blocks serotonin and dopamine receptors.
D. vaccination against C. tetani has not significantly reduced the incidence of tetanus.
E. all are spore producing.

503. All of the following infectious disorders are associated with splenomegaly EXCEPT
A. leprosy.
B. toxoplasmosis.
C. tuberculosis.
D. typhoid fever.
E. cytomegalovirus.

504. Bacterial endotoxin
A. is exemplified by streptokinase.
B. is the cause of the severe form of diphtheria.
C. is the cause of gas gangrene.
D. is the outer cell wall of gram positive bacteria.
E. induces production of TNF.

505. In aseptic meningitis
A. the glucose in the CSF is raised.
B. the most commonly identified agent is an enterovirus.
C. there is a more fulminant course than bacterial meningitis.•
D. microscopically there is a large infiltration of lymphocytes.
E. there is no brain swelling.

506. In infectious diseases
A. bacterial endotoxin is a mucoprotein on the inner cell wall.
B. the molecular mechanisms of most exotoxins are unknown.
C. microbes that propogate in the lumen of the intestine are accessible to IgA antibodies.
D. macrophages in bronchi playa major role in protecting the lungs from bacterial infection.
E. bacterial adhesins that bind bacteria to host cells have a broad range of host cell specificity.

507. Staphylococcus aureus
A. has receptors on its surface that allow binding to host endothelial cells.
B. has a capsule that allows it to attach to artificial materials.
C. has a lipase that degrades lipids on the skin surface.
D. has enterotoxins that stimulate emetic receptors in the abdominal viscera.
E. all of the above.

508. In malaria
A. Plasmodium vivax causes severe anaemia.
B. innoculated sporozoites immediately invade the spleen.
C. parasites mature in red blood cells.
D. Plasmodium falciparum infection initially causes hepatomegaly.
E. cerebral malaria is caused by parasites invading gray matter.

509. In males the relative risk of cigarette smoking causing a cancer is highest for
A. lung.
B. larynx.
C. oesophagus.
D. lip, oral cavity and pharynx.
E. pancreas.

510. Cessation of cigarette smoking causes the most prompt reduction in risk for
A. lung cancer.
B. chronic obstructive airway disease.
C. myocardial infarction.
D. stroke.
E. cancer of the bladder.