Presumptive dirofilariasis in a pale-headed saki monkey (Pithecia pithecia).

A 6-yr-old male pale-headed saki monkey (Pithecia pithecia), born at the Dallas Zoo, reentered the collection in 1994 after it was housed for 4 yr in Rhode Island and 2 yr in Florida. The monkey tested negative for both Dirofilaria immitis microfilariae and D. immitis adult antigens (via commercially available tests) upon return. However, it tested positive for adult antigens 1 yr later, and additional testing, including ultrasonography, suggested a diagnosis of aberrant dirofilariasis. Relevant evidence of previous microfilaremia in pale-headed saki monkeys at the Dallas Zoo is reviewed. Dirofilaria immitis infection should be included in the differential diagnosis list for any nonhuman primate with cardiopulmonary disease wherever the parasite is enzootic.

Papaverine-induced penile blood flow acceleration in impotent men measured by duplex scanning.

We assessed the value of penile blood flow acceleration as a parameter in the evaluation of the penile arteries. Duplex sonography and pulsed Doppler analysis with papaverine were performed in 50 impotent men. Measured parameters included cavernous artery diameters before and after papaverine, post-papaverine peak blood flow velocity and blood flow acceleration. Erections were graded subjectively on a scale of 1 to 4, with 4 being a full erection. Penile blood flow acceleration appeared to correlate with vessel dilatability and poor erectile response, and was subjectively more discriminating than peak blood flow velocity. This parameter provides additional measurable data about arterial function and should be obtained in addition to the other 2 parameters.

Effect of a left atrium-pulmonary vein baroreflex on peripheral vascular beds.

A step increase of left atrial and pulmonary venous pressure from 0 to 25 mmHg was used in anesthetized dogs with controlled arterial blood pressure to generate reflex systemic vasodilation. The resultant response of total peripheral resistance was an initial transient fall of about 40% which spontaneously regressed while the stimulus was maintained. Injections of differently tagged radioactive microspheres were used to measure selected organ blood flows prior to raising atrial pressure, at the response peak, during the steady state, and after recovery. Resistances of skin, skeletal muscle, kidney, and large intestine significantly fell upon atriovenous distention. The response in muscle, which greatly exceeded that of the other organs, was not sustained, whereas resistances of other responding beds remained depressed until the stimulus was removed. No significant responses occurred in small intestine, liver (hepatic artery), or adrenal gland.