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Biomedical subjects

W D Robertson

Publications and source records attributed to W D Robertson.

5 recordsLinked to original sources
PubMed1979

High resolution real time ultrasound of the carotid bifurcation.

We have been using a high resolution real time ultrasound mechanical sector scanner to visualize the carotid bifurcation. Twenty-six patients were studied before carotid arteriography for transient ischemic attacks. One bifurcation was not adequately visualized. Of the remaining 51, plaques were identified correctly in 29; absence of plaques was identified correctly in 15; small plaques were demonstrated by ultrasound in two that did not appear on the arteriogram; and four small plaques and one significant stenosis were not identified by ultrasound.

Arteriosclerosis↗
PubMed1979

Ixodicidal resistance in Boophilus microplus (Canestrini) in the Republic of South Africa and Transkei.

A series of in vitro trials using unfed larvae and fully fed adult ticks confirmed ixodicidal resistance in the one-host Pantropical Blue Tick, Boophilus microplus (Canestrini). Fifty-seven of 64 field isolates were resistant to arsenic; 10 of 56 were resistant to toxaphene; 1 of 5 were resistant to lindane; 3 of 5 were resistant to dieldrin; 3 of 19 were resistant to DDT and 8 of 55 were resistant to the organophosphorus ixodicide, dioxathion. One of the field isolates resistant to dioxathion was also highly resistant to the carbamate, carbaryl, and to the organophosphorus ixodicides benoxophos and diazinon. A second was resistant to the organophosphorus ixodicides benoxophos, diazinon, carbophenothion, dicrotophos, ethion, fenitrothion and quintiofos. Low levels of resistance, less than 3X, were shown to chlorfenvinphos and coumaphos. No resistance was shown to chlorpyrifos, bromophos ethyl or the diamidine ixodicide, amitraz. In hand-spraying trials no variation in the susceptibility of an organophosphorus resistant strain or the susceptible laboratory strain to amitraz was observed. This is the first recorded resistance to ixodicides by B. microplus in Africa.

Animals↗
PubMed1978

Radiologic assessment of pituitary microadenomas.

Radiographs of 146 patients who had a pituitary adenoma removed by the transsphenoidal approach were reviewed. The area and volume of the sella were measured in all the patients. In 73 patients the sella had a normal size and appearance as shown on routine lateral and frontal radiographs. However, thin-section tomograms of the sella in these patients demonstrated findings indicative of an intrasellar mass in all but three instances. The diagnosis of pituitary microadenoma (adenoma less than 1.5 cm in diameter) may, therefore, be missed if only plain skull radiographs are used to assess the sella. No correlation could be shown between the location of the sellar changes seen using thin-section tomography and the histologic type of pituitary adenoma.

Adenoma↗
PubMed1977

An epizootic of waterfowl associated with a red tide episode in Florida.

During February and March, 1974, an epizootic involving lesser scaup (Aythya affinis) occurred in the Tampa Bay area on the west coast of Florida. Several thousand ducks are estimated to have died. Concurrent with this epizootic was a red tide caused by heavy blooms of the toxic dinoflagellate Gymnodinium breve intoxication were evident in some of the lesser scaup. A controlled experimental feeding of G. breve toxic material to White Pekin ducklings produced illness and death with signs comparable to some of those seen in the scaup.

Animals↗