Biomedical subjects
Publications and source records attributed to C Gray.
Physicians who practise alternative medicine are paying close attention to the case of an Ontario physician who was found guilty of professional misconduct. The College of Physicians and Surgeons of Ontario says it is simply doing its job.
PURPOSE: To determine the accuracy of a target controlled infusion system for ketamine and to assess its suitability for the provision of analgesia when used in conjunction with a propofol infusion in spontaneously breathing patients. METHODS: Nineteen, adult, ASA I-III patients scheduled for elective surgery were studied. After premedication with 20 mg temazepam an appropriate plasma concentration of ketamine was selected and, when the target controlled infusion (TCI) system indicated that this had been achieved, anesthesia was induced and maintained using a propofol infusion. The plasma ketamine concentration was measured at predetermined intervals and cardiovascular and respiratory parameters recorded at 10 min intervals. Patients were reviewed in recovery and 24 hr postoperatively to assess the adequacy of their recovery and the presence of any undesirable side effects. RESULTS: The TCI system had a median performance error against predicted plasma concentrations of 18.9% (SE 2.5%) and a median absolute performance error of 23.3% (SE 2.3%). Divergence was 20.3% (SE 30.1%) and wobble was 12.9% (SE 2.1%). There was a mean decrease in arterial pressure of 6.4% (SD 19.7%) and a mean increase in heart rate of 4.3% (SD 17.4%). Little respiratory depression occurred and all patients made a rapid postoperative recovery with none describing unpleasant dreams or hallucinations. CONCLUSION: The TCI system provided a clinically acceptable degree of control of the plasma ketamine concentration although some further improvement should be possible by amending the pharmacokinetic model. Clinically the combination with a propofol infusion proved to be a satisfactory anesthetic technique.
Evidence showing that non-verbal short-term memory has distinct visual and spatial/sequential components is reviewed. A new test, The Visual Patterns Test (VPT), which was designed to measure short-term visual memory largely shorn of its spatio-sequential component, is described. Correlational studies of the VPT and the Corsi Blocks Test with healthy subjects and brain-damaged patients indicate a separation between visual and sequential abilities. This separation of function is supported by double dissociations shown by patients. Moreover, in a selective interference experiment, the VPT and the Corsi tests were found to show a double dissociation pattern of interference from visual and spatio sequential subsidiary tasks, respectively. The present results are discussed in relation to other findings in the literature, and it is concluded that non-verbal short-term memory can indeed be viewed as comprising distinct visual and spatio-sequential components. The VPT will be a useful neuropsychological instrument for measuring the visual component.
OBJECTIVES: To improve performance with mnemonic techniques for remembering words and proper names. DESIGN: For word recall, a 2 x 2 factorial in which type of pretraining and length of training were between-subjects manipulations. For proper name recall, a two-group design in which type of pretraining was manipulated between subjects. SETTING: Community. PARTICIPANTS: 268 community-dwelling adults over the age of 55 years who wished to improve their memory. MEASUREMENTS: Recall of words and proper names both before and after training in mnemonics. INTERVENTION: Participants received a 2-week training course on two mnemonic techniques, the method of loci for words and a name association technique for proper names. RESULTS: There was no effect of the pretraining manipulation on proper name recall. For word recall, however, a multiple regression that included age indicated that the older-old participants benefited more from a combination of comprehensive pretraining and extended mnemonic training than did the younger-old. CONCLUSIONS: Increased training time coupled with a comprehensive pretraining regimen can improve the performance of the older-old in using mnemonics; this improved performance cannot be attributed solely to enhanced knowledge of the mnemonic.
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OBJECTIVE: To review the etiology, clinical decision-making process, and outcomes of apparent life-threatening events (ALTEs) presenting to a children's hospital emergency department (ED). DESIGN: Retrospective patient record review. SUBJECTS: One hundred thirty infants under the age of 1 year fulfilling the diagnostic definition of an apparent life-threatening event. RESULTS: In a calendar year, 130 infants presented to a large children's hospital ED. The total number of ALTEs studied was 196. The median age was 2 months, and 50% of infants had a normal clinical examination. Eighty-three percent of ALTEs resulted in admission to the hospital. The approach to investigation and management of an ALTE during admission appeared unstructured. Discharge diagnoses, both from the ED and the inpatient service, were numerous, the most common being convulsion, febrile convulsion, GOR, and lower respiratory tract infection. The diagnosis frequently changed in those attending more than once. Eighteen months after cessation of data collection, no infants had died. Follow-up information revealed a higher-than-expected prevalence of asthma and seizures. CONCLUSIONS: This is a diverse group of infants, many of whom appear normal following the ALTE. There are many possible diagnoses, but diagnosis correlates poorly with presenting symptoms. It also appears that many commonly performed investigations conducted in this group of infants may not be those that are most helpful for diagnosis, and doctors may be making diagnoses with little supportive evidence. Until research on this group of "first-presentation" infants provides management guidelines for family and emergency doctors, it may be prudent to advise that all such infants presenting with an ALTE should be admitted for a period of observation and further investigation. This would help ensure more accurate diagnosis, as well as provide reassurance for the family.
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Editorial writers from the US descended on Ottawa recently for their annual meeting, and CMAJ contributing editor Charlotte Gray was one of the speakers. She said the visitors received widely differing views on the Canadian health care system and may have emerged from the meeting more confused than informed.
betaA4 (Abeta) amyloid peptide, a major component of Alzheimer's disease (AD) plaques, is a proteolytic product of the amyloid precursor protein (APP). Endoproteases, termed beta- and gamma-secretase, release respectively the N- and C-termini of the peptide. APP default secretion involves cleavage within the betaA4 domain by alpha-secretase. To study the conservation of APP processing in lower eukaryotes, the yeast Pichia pastoris was transfected with human APP695 cDNA. In addition to the full-length integral transmembrane protein found in the cell lysate, soluble/secreted APP (sAPP) was detected in the culture medium. Most sAPP comprised the N-terminal moiety of betaA4 and corresponds to sAPPalpha, the product of alpha-secretase. The culture medium also contained minor secreted forms detected by a monoclonal antibody specific for sAPPbeta (the ectodomain released by beta-secretase cleavage). Analysis of the cell lysates with specific antibodies also detected membrane-associated C-terminal fragments corresponding to the products of alpha and beta cleavages. Moreover, immunoprecipitation of the culture medium with three antibodies directed at distinct epitopes of the betaA4 domain yielded a 4 kDa product with the same electrophoretic mobility as betaA4 synthetic peptide. These results suggest that the alpha-, beta-, and gamma-secretase cleavages are conserved in yeast and that P. pastoris may offer an alternative to mammalian cells to identify the proteases involved in the generation of AD betaA4 amyloid.
Federal Minister of Health Allan Rock appears committed to improved funding for the health care system, but this may be a hard sell in cabinet. He outlined his views during the CMA's recent annual meeting in Whitehorse.
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If Canada's medicare system has a home town it is probably Ottawa, where the system was first welded together 30 years ago. Charlotte Gray reports that there is a certain irony now that examples of private health care are sprouting up in the nations's capital.
First, Ontario decided it would close or reduce the operations of 3 Ottawa hospitals and combine 2 others. When the board for the combined hospital named a Parti Québécois confidant the new hospital's CEO, it hoped David Levine's background would go unnoticed. As Charlotte Gray reports, it didn't, and Levine became the lightning rod for a lot of anger.
Health Canada and the Canadian-Italian Physicians Association recently spent $20,000 to send 4 Canadian cancer specialists to Italy to check out the "miracle" anticancer cocktail prepared by an Italian physician. Most doctors remain decidedly sceptical about this latest "cure," but Charlotte Gray says their suspicions count for little when an issue like this captures the imagination of the public and their politicians.