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Biomedical subjects

W D Robertson

Publications and source records attributed to W D Robertson.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1978

The current status of resistance to organophosphorus ixodicides by the blue tick, Boophilus Decoloratus (Koch) in the Republic of South Africa and Transkei.

In a four year survey 253 isolates of Boophilus decoloratus from the Republic of South Africa and Transkei were tested in the laboratory for their susceptibility to certain organophosphorus ixodicides. Fifty-seven of these isolates were susceptible to organophosphorus compounds, 88 isolates showed a range of susceptibility between that of the susceptible laboratory strain and a strain having a resistance greater than that for the Berlin type strain. A field trial confirmed degrees of resistance shown in the laboratory to the organophosphorus ixodicides benoxophos, chlorfenvinphos, dioxathion, dicrotophos, quintiofos and chlorfenvinphos/dioxathion.

Drug Resistance↗
PubMed1978

Resistance to certain organophosphorus ixodicides in the bont tick, Amblyomma hebraeum Koch, in the Republic of South Africa and Swaziland.

A series of in vitro trails confirmed resistance in the three-host tick, Amblyomma hebraeum Koch, to the organophosphorus ixodicides, dioxathion, chlorfenvinphos, quintiofos, bromophos-ethyl and a dioxathion/chlorfenvinphos combination. The results of a routine survey showed that a resistance factor of greater than 100x was present in the offspring of ticks in six of 115 field isolates tested. These six isolates were confined to the lowveld areas of the province of Natal, Republic of South Africa, and Swaziland. Ticks in a further 59 isolates were less susceptible than the reference strain. Resistance was present in all three tick instars. This is the first recorded resistance to the organophosphorus group of ixodicides by multi-host ticks in Africa.

Drug Resistance↗
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↗
PubMed1977

Pebble ingestion: an unusual form of geophagia.

Reported is a case representing an unusual form of geophagia, in which ingestion of pebbles by a 27-year-old mentally retarded woman resulted in impaction and complete filling of the colon with pebbles. Conservative therapy was successful in clearing the stones by the sixth day of treatment; however, a follow-up visit approximately six weeks later revealed that the patient was again ingesting pebbles.

Adult↗
PubMedDate not supplied

Clinical experience with Hexabrix in cerebral angiography.

Sixty patients from the University of British Columbia, Vancouver General Hospital, and University of Alberta Hospitals Edmonton participated in an open-labelled clinical study on the safety, tolerability and efficacy of ioxaglic acid (Hexabrix) in cerebral angiography. Only 4% of patients experienced significant pain during carotid and brachiocephalic injections of Hexabrix. No increased incidence of side effects or adverse effects were encountered. In addition, radiographic film quality overall was excellent and comparable to that obtained using conventional contrast agents. Hexabrix is a safe and effective contrast agent for cerebral angiography.

Adolescent↗
PubMedDate not supplied

Computed tomography of a cerebellopontine angle lipoma.

In this report we document the clinical, radiologic, surgical, and pathologic features of a cerebellopontine angle (CPA) lipoma, including the CT visualization of the seventh and eighth cranial nerves passing through the middle of the lesion, a feature previously undescribed. Comparison is made with other reported CPA lipomas.

Adult↗
PubMedDate not supplied

Computed tomography of anterior inferior cerebellar artery aneurysm mimicking an acoustic neuroma.

Twenty-one previously reported cases of aneurysms of the anterior inferior cerebellar artery (AICA) were reviewed. They often present acutely with subarachnoid hemorrhage due to rupture, or less frequently with an insidious onset, as a cerebellopontine angle (CPA) mass. Rupture of the aneurysm is usually not difficult to diagnose because of the acute symptoms and the subarachnoid hemorrhage, which can easily be detected by CT or lumbar puncture. However, caution must be exercised in those lesions presenting as a CPA mass clinically, which on CT appear unusually dense with contrast enhancement. Erosion of the internal auditory canal may be present but is non-specific. If an enhancing CPA mass appears atypical and dynamic CT confirms rapid enhancement, vertebrobasilar angiography is essential to establish an AICA aneurysm as the cause.

Adult↗
PubMedDate not supplied

Computed tomography of calvarial and petrous bone sarcoidosis.

This report describes the radiographic features in a case of sarcoidosis involving both the frontal calvaria and the petrous bone. The plain radiographic and nuclear medicine findings were consistent with previous descriptions. High resolution CT demonstrated concentric growth with a lucent advancing margin, ghost-like remnant of partially replaced bone, crossing of suture lines, invasion of contiguous bones, and lack of associated soft tissue mass.

Bone Diseases↗