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Biomedical subjects

W D Robertson

Publications and source records attributed to W D Robertson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Orbital dermoids: features on CT.

The computed tomographic (CT) features of orbital dermoids were retrospectively reviewed in 17 patients; 15 of the lesions were proved histologically. On the basis of clinical and CT features, the tumors were classified as superficial or deep. All but one were extraconal in location. Seven lesions appeared cystic; only six showed typical fat density. The presence of a margin or rim, often partially calcified, was identified in ten lesions. Irregular scalloping of adjacent bone was a highly suggestive feature, occurring with 11 dermoids. Other bone changes, such as linear defects, thinning, or sclerosis, also occurred. Superficial dermoids showed less apparent bone changes. An extraconal orbital lesion associated with adjacent bone thinning or notching should raise the possibility of a dermoid, especially if a rim with calcification is seen. The appearance is pathognomonic if fat density is also present.

Adolescent↗
PubMed1987

Assessment of multiple sclerosis lesions by magnetic resonance imaging.

Fifty patients clinically suspected to have multiple sclerosis (MS), who were classified by Schumacher's criteria into three clinical categories (definite, probable, or possible MS), underwent complete brain magnetic resonance (MR) scans. The T2-weighted spin echo (SE) pulse sequence was more sensitive than inversion recovery (IR) in detecting MS lesions. Greater than 50% of the lesions demonstrated by SE were missed on the corresponding IR slices. However, lesions in the brainstem were more readily assessed using IR. MS lesions appeared larger on SE than on IR. Fifty-five percent of SE-demonstrated lesions were 1 to 2 cm or larger in size, while only 32% of IR-demonstrated lesions were greater than 1 cm. Axial and coronal planes of study demonstrated the same number, size, and location of lesions.

Adult↗
PubMed1986

A comparison of the new topical antibiotic mupirocin ('Bactroban') with oral antibiotics in the treatment of skin infections in general practice.

A trial was carried out in general practice in 200 patients presenting with skin infections to compare topical antibiotic treatment with mupirocin ointment with orally administered flucloxacillin or erythromycin. Patients were assigned at random to receive 4 to 10 days' treatment with either mupirocin applied 3-times daily or one of the oral antibiotics in the dosage normally used by the general practitioner for skin infections. The majority of infections were impetigo and infected wounds/lacerations; the main organisms isolated initially from 127 of the patients were either Staphylococcus aureus or beta-haemolytic Group A streptococci. Clinical response to mupirocin ointment (86% cured, 13% improved) was significantly better than that seen with erythromycin (47% cured, 26% improved) and similar to that with flucloxacillin (76% cured, 23% improved). Treatment outcome was not related to treatment duration with either the topical or oral preparations. Post-treatment samples from 76 patients showed that in the mupirocin group all the pathogens originally isolated were eliminated, including Gram-negative organisms.

Administration, Topical↗
PubMed1986

Value of intravenous contrast enhancement in the CT evaluation of intraspinal tumors.

The usefulness of intravenous contrast-enhanced CT in delineating intraspinal cord tumors has not been well documented. To determine if intradural spinal tumors enhance, if the location and type of tumor can be determined, and if a double dose of contrast material provides more information than a single dose, a retrospective study of 23 patients with proven intradural extramedullary or intramedullary tumors was performed. All the tumors studied with CT after intravenous contrast enhancement showed that most lesions (18/23) enhanced, contrary to published reports. Contrast-enhanced studies delineated the extent of the tumor, helping to separate solid and cystic components. The enhancement pattern of ependymomas and astrocytomas was similar, while schwannomas had a characteristic appearance. A double dose of intravenous contrast material had no apparent advantage over a single dose.

Adolescent↗
PubMed1983

Eye-pressing by visually impaired children.

Many children with severely impaired sight exhibit stereotyped mannerisms. Visual self-stimulation, e.g. eye-pressing and light-gazing, normally is restricted to the visually impaired; prolonged eye-pressing is the most common. This behaviour depends on onset of visual impairment, age, degree and quality of residual light, type of ocular abnormality, the presence of additional handicaps, and the activities in which the child is involved. Children with bilateral optic-nerve defects never press their eyes; those with retinal disorders tend to press vigorously. A possible physiological explanation is that self-stimulation occurs when the demand of the brain for meaningful visual information is not adequately met.

Adolescent↗
PubMed1982

Computed tomographic diagnosis of intraventricular hemorrhage. Etiology and prognosis.

Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrhage rather than obstruction of the ventricular system by blood. IVH per se is seldom a major factor in the neurological outcome.

Adolescent↗
PubMed1982

Transient early computed tomographic changes mimicking tumor progression after brain tumor irradiation.

Transient computed tomographic (CT) changes occurring within three months after radiotherapy are described in three patients with cerebral gliomas. These changes consist of enlargement of an area of central necrosis, new tumor enhancement, and increased tumor enhancement with adjacent low-density changes. Subsequent scans showed regression of these changes in all patients. It is proposed that these changes are the direct effect of radiation on tumor tissue and adjacent normal brain; possible mechanisms are discussed. These radiation-induced changes mimic tumor progression on CT. The importance of recognizing their transient nature is stressed.

Adolescent↗
PubMed1982

Computed tomographic scanning of the cerebellopontine angle and the internal auditory canal.

CT scanning of the posterior fossa has been available for eight years, with continued and marked improvements in the scanning accuracy and resolution, particularly in the past three years. Newer computer programs combined with thin axial and coronal slices allow discovery of lesions that are millimeters in size. CT scanning has become the method of choice for screening patients with symptoms referrable to the posterior fossa and is also the most accurate radiographic method of detection. By demonstrating lesions less than one cm in size, CT has greatly enhanced the diagnosis and improved the management of patients who suffer from posterior fossa lesions.

Adult↗
PubMed1981

Acute orbital pseudotumors: classification and CT features.

Acute orbital pseudotumors are inflammatory lesions of unknown etiology that may affect part or, less often, all of the tissue within the orbit. A retrospective computed tomographic (CT) study of 16 patients demonstrated that these lesions occur in one of five specific anatomic patterns: anterior, posterior, diffuse, lacrimal, or myositic. The most common location was lacrimal followed by anterior pseudotumors. Posterior, most common location was lacrimal followed by anterior pseudotumors. Posterior, diffuse, and myositic pseudotumors were equally frequent. Localization on the basis of clinical features correlated with the CT localization. Illustrative cases of each of the five types are included. The role of CT in evaluating the therapeutic response is discussed.

Acute Disease↗
PubMed1980

Carotid injury due to intraoral trauma: case report and review of the literature.

This report describes a 25-month-old child with an internal carotid artery injury that was caused by a fall upon the sharp end of a comb held in the mouth. The initial injury appeared trivial, but 24 hours later a right cerebral hemispheric infarct occurred. Delayed deterioration was caused by increased intracranial pressure and transtentorial herniation. Aggressive medical therapy was instituted for the control of intracranial pressure. The clinical and radiographic features are described in detail and the pertinent literature is reviewed. This is the first reported patient with this condition who survived once transtentorial herniation was present.

Adolescent↗
PubMed1980

Positioning of patients after metrizamide lumbar myelography.

This prospective study of 90 patients after lumbar metrizamide myelography indicates that the semiupright position at 45 degrees in bed or early ambulation reduces postprocedure vomiting but does not reduce the frequency of headache. Ambulatory patients have less frequent nausea than patients kept in bed.

Female↗
PubMed1980

Three mile island.

Explore the source record for details and available documents.

Journal Article↗
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↗