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Biomedical subjects

G Ferguson

Publications and source records attributed to G Ferguson.

84 records · Page 5Linked to original sources
PubMed1983

Intraventricular hemorrhage from ruptured aneurysm. Retrospective analysis of 91 cases.

Intraventricular hemorrhage (IVH) from aneurysm rupture is generally considered to be of grave prognostic significance. Ninety-one cases have been studied retrospectively from seven medical centers. The overall mortality rate was 64%. The dramatically poor condition of these patients leads to their rapid admission to the hospital. Eighty-seven percent were admitted on Day 0 or 1, and more than half were classified neurologically as Grade 4 or 5. A multiple regression analysis explained 56% of the variance in survival, using the variables of ventriculocranial ratio (VCR), day of admission, diastolic blood pressure, location of aneurysm, associated intracerebral hematoma, age, grade on admission, sex, and systolic blood pressure. No patient with a VCR of more than 0.25, as calculated from the initial computerized tomography (CT) scan, survived. No patient whose smallest VCR was 0.23 or more survived. This ratio can be simply measured with a millimeter ruler from the CT scan. Patients with IVH usually had enlarged ventricles, even initially. The overall results suggest that early management of intracranial hypertension should be more generally considered, although even when this was done the prognosis was still guarded. The timing of surgery was not an important determinant of outcome, although a significant number of patients died awaiting surgery.

Adolescent↗
PubMed1976

Perceptual and motor training for the acquisition and retention of psychomotor skills in dental amalgam restorations: class I in the mandibular first molar.

From a study of 72 dental students during amalgam restoration using four training methods (psychomotor, mental, psychomotor and mental, and conventional)--one method for each 18 students--the following conclusions are drawn: (1) It is economically feasible to develop and utilize self-paced instructions without the aid of instructors for the acquisition of psychomotor skills. (2) Training through self-paced analytical programs results in higher retention of the acquired skills than training through conventional training methods.

Dental Amalgam↗
PubMedDate not supplied

Physical factors determining the utility of radiation safety glasses.

Ten types of lenses were tested for their radiation protection properties in three experimental circumstances: (a) Their good geometry (scatter free) attenuation was determined as a function of HVL in a direct x-ray beam. (b) Their dose reducing properties were determined under simulated clinical fluoroscopic conditions, using both ion chambers and thermoluminescent dosimeters (TLD's) while the lenses, mounted in frames, were worn by a head phantom. The head was oriented in four different directions to simulate clinical conditions in a fluoroscopic room. (c) Their dose reducing properties were measured with TLD's while the glasses were worn by radiologists during clinical fluoroscopic procedures. Although several of the lenses could attenuate a direct x-ray beam several thousand times, none of the glasses offer more than a factor of 8 reduction in eye exposure when the glasses are worn during fluoroscopy. This is attributed to backscatter from the fluoroscopist's head and deficient lateral shielding. Some of the glasses may even be causing an increase in eye exposure when the TV monitor is located 90 degrees or more from the patient.

Eye Protective Devices↗
PubMedDate not supplied

No evidence of infection with porcine endogenous retrovirus in recipients of encapsulated porcine islet xenografts.

Transplantation of pig tissues into humans has the potential for cotransferring pig infections. Knowledge of the epidemiology of pig infections transmissible to humans allows the development of risk limitation strategies at the source herd level, but potentially infectious pig endogenous retrovirus (PERV) is ubiquitous in all domestic pigs and therefore is not avoidable. Using a specific and sensitive RT-PCR and nested PCR for PERV nucleic acids with primers, the screening of pigs from New Zealand herds for the presence and expression of the PERV was conducted. The presence of PERV proviral DNA (pol and env region) and viral RNA was demonstrated in all tested pig tissues including pancreas, liver, spleen, brain, heart, and PBMC. Using the same assays it was established that different tissues (liver, spleen, and heart) of nude and nonobese diabetic (NOD) mice previously transplanted with nonencapsulated pig islets were PERV DNA and RNA negative. Alginate polylysine capsules prepared with encapsulated pig islets were tested for possible leakage of viral particles or viral nucleic acids. RNA was extracted from the supernatant of viable encapsulated pig islet cells grown in culture for 2 months. No evidence of PERV RNA or of cellular nucleic acids could be found. Two adult type I diabetic subjects were transplanted with 1 x 10(6) neonatal pig islets encased in alginate capsules into the peritoneal cavity. One patient was immunosuppressed. Both showed evidence of graft function (up to 34% reduction in insulin dose, corresponding increase in serum pig C-peptide) for up to 2 years. DNA and RNA were extracted from PBMC and blood plasma of both patients at 19 months posttransplant. No evidence of PERV proviral DNA or RNA could be detected. Piglet islets contain PERV DNA and RNA, but this does not traverse the capsules used or produce any evidence of infection in nude and nonobese diabetic (NOD) mice or humans.

Adult↗
PubMedDate not supplied

Giant unclippable aneurysms: treatment with detachable balloons.

Nine cases of giant unclippable aneurysms treated with the detachable balloon technique are reported. Adjunctive surgical bypass procedures and arterial ligation were also carried out in four and one cases, respectively. All the patients tolerated occlusion of the carotid artery (eight cases) or of both vertebral arteries (one case). Three patients developed neurologic complications: two transient and one permanent (blindness in one eye). The complications occurred when attempts were made to occlude the aneurysm lumen only to preserve the carotid blood flow. Permanent occlusion of the carotid artery appears safer than aneurysm obliteration. Surgical procedures are necessary if the patient does not tolerate permanent occlusion of the artery or if occlusion of the artery is insufficient to obtain thrombosis of the aneurysm.

Adolescent↗