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Biomedical subjects

A Morris

Publications and source records attributed to A Morris.

At least 163 records · Page 9Linked to original sources
PubMed1994

The challenges of educational program evaluation.

The demand for fiscal restraint and accountability has forced health care facilities to carefully evaluate the benefits of new programs. Some time ago, the Long Term Care Nursing Department of Sunnybrook Health Science Centre in Toronto, Ontario, collaborated with Centennial College to provide a Gerontology Certificate Program to registered nurses. While originally conceived as a retention and recruitment strategy, it became obvious that such a program could and should have additional benefits to staff and long term care residents alike. This article describes the changes as indicated by three scales, and the benefits described by the registered nurses. It also illustrates, rather humorously, that even the more educated and experienced among us can make mistakes and learn from them!

Aged↗
PubMed1993

The molecular basis of a spectral shift in the rhodopsins of two species of squid from different photic environments.

The molecular basis of spectral tuning of rhodopsin pigments in two squid species is examined. The absorbance spectra of rhodopsin extracts from Alloteuthis subulata (lambda max 499 nm) showed a 5 nm red shift compared with Loligo forbesi (lambda max 494 nm). The rhodopsin gene sequence of A. subulata opsin was determined from polymerase chain reaction (PCR) amplified fragments by using genomic DNA as template. The deduced amino acid sequence was compared with that obtained from the previously published cDNA sequence of Loligo forbesi. A total of 22 amino acid differences are present, although only seven can be considered to be non-homologous substitutions. Three of these changes occur in helical transmembrane regions but only one, the substitution of phenylalanine by serine at site 270 in Alloteuthis subulata, involves the replacement of an apolar with a hydroxyl-bearing residue at a site located near the centre of helix VI and on the inner face of the retinal-binding pocket. The equivalent site is also used for the spectral tuning of primate cone pigments, an example of convergent evolution. It is proposed that substitution at this site is responsible for the 5 nm red shift. The relation between this spectral shift and the maximum depth distribution of Alloteuthis subulata of about 200 m, compared with about 360 m for Loligo forbesi, is discussed. An unexpected finding was that the rhodopsin gene of both species appears to lack introns.

Amino Acid Sequence↗
PubMed1993

A low-temperature-responsive translation elongation factor 1 alpha from barley (Hordeum vulgare L.).

A cDNA clone (pBLT63) encoding a protein synthesis elongation factor 1 alpha (EF-1 alpha) was isolated from a low-temperature winter barley shoot meristem library by differential screening. The nucleotide sequence of the coding region of the low-temperature-induced barley gene shows very high homology with two EF-1 alpha plant genes from tomato and Arabidopsis. The barley genome contains an EF-1 alpha gene family situated on the short arm of chromosome 2 and the long arm of chromosome 5.

Amino Acid Sequence↗
PubMed1993

Interactions between interferon gamma and retinoic acid with transforming growth factor beta in the induction of immune recognition molecules.

The cell-surface expression of major histocompatibility (MHC) antigens and the adhesion molecule intercellular adhesion molecule 1 (ICAM-1) is essential for target cell recognition by T lymphocytes. The expression of both classes of molecule is induced by various cytokines, notably interferon gamma (IFN gamma). Since transforming growth factor beta (TGF beta) has been recently reported to antagonise HLA-DR induction by IFN gamma we have examined, using a number of murine and human cell lines, the effect of TGF beta on IFN gamma-induced MHC class I and class II and ICAM-1 expression. All of the cell lines tested expressed elevated class I MHC following IFN gamma treatment. Class II MHC induction was seen on most but not all of the cells, the exceptions being among a panel of human colorectal carcinoma cell lines. A striking difference between cells of different origin was noted in the response to TGF beta. TGF beta was found to antagonise IFN gamma-induced class I and class II MHC expression on C3H 10T1/2 murine fibroblasts, early-passage BALB/c mouse embryo fibroblasts, a murine oligodendroglioma cell line, and on MRC5 human fibroblasts and two human glioblastoma cell lines. Class II MHC was much more strongly inhibited (sometimes completely) than class I MHC. TGF beta also inhibited induction of class I MHC expression by IFN alpha. However, TGF beta did not inhibit class I or class II MHC induction by IFN gamma in any of the nine colorectal carcinoma cell lines, although two of five of the lines tested were growth-inhibited by TGF beta. On the other hand, human ICAM-1 induction by IFN gamma was not affected by simultaneous treatment with TGF beta in any of the cell lines. The down-regulation of IFN gamma-induced MHC antigens by TGF beta is not, therefore, the result of a general antagonism of IFN gamma. Retinoic acid has recently been reported to induce ICAM-1 expression on human tumour cells. We have confirmed this observation on MRC5, and the two human glioblastoma cell lines, however six colorectal carcinoma cell lines tested did not respond. In contrast to IFN gamma-induced ICAM-1 expression, retinoic-acid-induced ICAM-1 expression was inhibited by TGF beta on two of the three responsive lines.

Animals↗
PubMed1993

A review of cervical fractures and fracture-dislocations without head impacts sustained by restrained occupants.

Crash injury reduction via lap-shoulder belt use has been well documented. Like any other interior car component, lap-shoulder belts may be related to injury in certain crashes. Relatively unknown is the fact that cervical fractures or fracture-dislocations to restrained front seat occupants occur where no head contact was evidenced by both medical records and car inspection. A review of the available literature on car crash injuries revealed more than 100 such cases. A review of the National Accident Severity Study (NASS) 80-88 file was also conducted, revealing more examples. Case capsule descriptions from the authors' files are also detailed along with examples of such injuries in infants and children in child restraints. However, cervical fractures or fracture dislocations are rare, as evidenced by the relatively few cases identified in the literature, in the author's files, and by an analysis of NASS 80-90 data that revealed a cervical spine injury frequency of only .4% at the AIS-3 level (Huelke, Morris, and Mackay 1992).

Accidents, Traffic↗
PubMed1993

Mycobacteria in stool specimens: the nonvalue of smears for predicting culture results.

A previous recommendation suggests that stool be cultured for mycobacteria only if the smear is positive. We have correlated smear and culture results of 2,176 stool specimens submitted for mycobacterial culture. The sensitivity, specificity, and positive and negative predictive values for smears to predict culture results are 34, 99, 90, and 87%, respectively. We recommend that the stool smear not be used as a screening technique to decide which specimens from at-risk patients should be cultured because it lacks the necessary sensitivity.

AIDS-Related Opportunistic Infections↗
PubMed1993

Adequacy of food rations in soldiers during an arctic exercise measured by doubly labeled water.

To investigate the adequacy of food rations to supply energy needs in cold-temperature environments, caloric expenditure and intake and body composition changes were measured in a group of infantrymen during a 10-day field exercise in the Canadian Arctic. Energy expenditure was measured by the doubly labeled water method (n = 10), and caloric intake was measured by complete food intake records (n = 20). Body composition was determined by isotope dilution (n = 10) and bioelectrical impedence analysis (n = 20) on days 0 and 10. Baseline isotopic enrichment shifts due to geographical relocation were also monitored (n = 5). Mean body weight decreased 0.63 +/- 0.83 (SD) kg over the study period (P < 0.005), although fat-free and fat mass compartment changes were not significant. Baseline isotopic changes were -4.65 +/- 2.54 and -0.48 +/- 0.07 /1000/day for deuterium and 18O, respectively. Mean baseline corrected energy expenditure level was 4,317 +/- 927 kcal/day. Self-reported caloric intakes obtained from food records were 2,633 +/- 499 kcal/day (61.0% of expenditure). Rations packs contained 4,350 kcal/day. Results suggest that 1) food intake was significantly underreported and 2) the energy needs of most subjects were being met by rations and available supplements.

Arctic Regions↗
PubMed1992

Maintenance of lower proportions of (n - 6) eicosanoid precursors in phospholipids of human plasma in response to added dietary (n - 3) fatty acids.

Competition between the (n - 3) and (n - 6) types of highly unsaturated fatty acids can diminish the abundance of (n - 6) eicosanoid precursors in a tissue, which in turn can diminish the intensity of tissue responses that are mediated by (n - 6) eicosanoids. The mixture of 20- and 22-carbon highly unsaturated fatty acids maintained in the phospholipids of human plasma is related to the dietary intake of 18:2 (n - 6) and 18:3 (n - 3) by empirical hyperbolic equations in a manner very similar to the relationship reported for laboratory rats (Lands, W.E.M., Morris, A. and Libelt, B. (1990) Lipids 25, 505-516). Analytical results from volunteers ingesting self-selected diets showed an inter-individual variance for the proportion of (n - 6) eicosanoid precursors in the fatty acids of plasma phospholipids of about 5%, but the variance among multiple samples taken from the same individual throughout the day was less (about 3%), closer to the experimental variance of the analytical procedure (about 1%). The reproducibility of the results makes it likely that analysis of fatty-acid composition of plasma lipids from individuals will prove useful in estimating the diet-related tendency for severe thrombotic, arthritic or other disorders that are mediated by (n - 6) eicosanoids. Additional constants and terms were included in the equations to account for the effects of 20- and 22-carbon highly unsaturated (n - 3) fatty acids in the diet. A lower constant for the 20- and 22-carbon (n - 3) fatty acids compared to that for the 18-carbon (n - 3) fatty acid in decreasing the ability of dietary 18:2 (n - 6) to maintain 20:4 (n - 6) in tissue lipids confirmed the greater competitive effectiveness of the more highly unsaturated n - 3 fatty acids in the elongation/desaturation process. Also, a lower constant for direct incorporation of 20-carbon fatty acids of the n - 6 vs. the n - 3 type indicated a greater competitive effectiveness of 20:4 (n - 6) relative to 20:5 (n - 3) in reesterification after release from tissue lipids. The equations may be used in reverse to estimate the dietary intakes of the (n - 3) and (n - 6) fatty acids by using the composition of the fatty acids that had been maintained in plasma lipids.

Aged↗
PubMed1992

Antimicrobial susceptibility of anaerobic bacteria in Auckland 1987-90.

The antimicrobial susceptibility of 292 clinical isolates of anaerobic bacteria was determined by a standard agar dilution method. Metronidazole was the most active agent with only one Bacteroides fragilis, two anaerobic cocci, and Propionibacterium acnes being resistant. For B fragilis itself and other members of the B fragilis group: 35/35 (100%) and 43/44 (98%) respectively, were susceptible to amoxycillin-clavulanic acid; 47/47 (100%) and 55/56 (98%) respectively, were susceptible to cefoxitin; and 20/28 (71%) and 7/25 (28%) respectively, were susceptible to ceftriaxone. All four agents and penicillin were almost always active against anaerobic cocci and Fusobacterium species. All agents were active against clostridium isolates except for cefoxitin where only 47/57 (82%) were susceptible. These results allow comparison with isolates from other locations and may be considered when choosing an antimicrobial agent for prophylaxis or therapy of anaerobic infections.

Amoxicillin↗
PubMed1992

Peripheral mechanical loading and the mechanism of the tremor of chronic alcoholism.

The tremor of chronic alcoholism, although clinically similar to essential tremor, has been considered a distinct syndrome. Its underlying mechanism was analyzed in five patients (none in the acute stages of alcohol withdrawal) hospitalized in an alcohol detoxification program. All five patients performed tracking tasks in which they pursued a linearly moving "target" light with a response light that they controlled by flexion-extension activity of the wrist. Stationary and dynamic targets were used with both isometric and unconstrained wrist mechanical interfaces. Frequency, torque, and displacement tremor characteristics were examined under varying inertial loading or isometric voluntary torque conditions. Two simultaneous tremor components were present in all patients: a prominent 4- to 7-Hz low-frequency peak and a smaller-amplitude 9.4- to 9.6-Hz high-frequency peak. As the inertia of the hand was augmented during unconstrained tasks, the low-frequency peak decreased, while the high-frequency peak was unaffected. As required voluntary effort was increased during isometric testing, the amplitude of the low-frequency peak increased. These findings suggest that the low-frequency peak represents the significant pathologic component of the tremor of chronic alcoholism and that it has a biomechanical reflex mechanism similar to that of the lower-amplitude normal physiologic tremor.

Adult↗
PubMed1992

Improved diagnosis of chronic hepatitis C virus infection by detection of antibody to multiple epitopes: confirmation by antibody to synthetic oligopeptides.

Serum samples from 226 patients covering a wide spectrum of liver disease were tested for antibodies to hepatitis C virus (HCV) using both first and second generation enzyme linked immunosorbent assays. Selected sera were also tested by peptide immunoassays, by the four-antigen recombinant immunoblot assay (RIBA II), and for viral genome by the polymerase chain reaction. Antibody to c100-3 was detected in 61% of patients with chronic non-A, non-B (NANB) hepatitis and/or 46.5% with presumed NANB-related cirrhosis by the first generation test. These figures increased to 77% and 58% when antibodies to recombinant structural and non-structural HCV antigens were sought by the second generation assay. Supplemental testing against peptide Sp75 and Sp65/sp67 confirmed that reactivity of sera by second generation assays was due to antibodies to the additional structural and non-structural antigens. Samples negative by the first generation assay were not confirmed by the supplemental assay using peptides Sp75 and Sp65/Sp67. HCV RNA was detected in 60% of the anti-HCV positive sera tested, most of which were also RIBA II positive. Our findings confirm that the introduction of the structural and non-structural antigens, especially the putative nucleocapsid protein, improves sensitivity of detection of antibodies to HCV, and facilitates diagnosis in patients with "cryptogenic" chronic hepatitis.

Antigens, Viral↗
PubMed1992

Assessment of costs to donor hospitals for organ transplantation.

In 1987, die Department of Health in the UK set up a working party to identify reasons contributing to a shortfall in donor organs. One recommendation was reimbursement to the District Health Authorities for costs incurred in providing the donor organs. The figure chosen was not to be seen as an incentive to donate organs, merely as an appropriate compensation for the costs incurred. There would be no direct payment to doctors, trustees or relatives of the donor. With the development of the competitive health care environment in the United Kingdom, the reimbursement of donating hospital costs is being considered with these data.

Costs and Cost Analysis↗
PubMed1992

Cytokine augmentation of HIV-1 LTR-driven gene expression in neural cells.

The induction of human immunodeficiency virus type 1 (HIV-1) gene expression by cytokines was investigated in cells of central nervous system origin. These were human neuroblastoma, glioblastoma, and astrocytoma cell lines, a murine oligodendroglioma and primary murine astrocyte cultures. The cytokines used were tumor necrosis factor alpha (TNF alpha), interleukin-1 beta (IL-1 beta), IL-6, and interferons alpha and gamma (IFN alpha, gamma). Transient transfection of cells with a chloramphenicol acetyltransferase (CAT) reporter gene under the control of the HIV-1 long terminal repeat (LTR) showed significant augmentation following treatment by particular cytokines. TNF alpha was found to augment HIV LTR-directed CAT activity in all cell types. IL-1 beta also activated the HIV LTR reporter gene in glioblastoma, astrocytoma, and astrocyte cells. IL-6 enhanced HIV gene expression in one example only, the primary astrocyte cultures. The interferons generally suppressed expression from the LTR except IFN gamma which produced a twofold rise in the murine glial cells and IFN alpha augmenting expression in one neuroblastoma cell line. No synergy was observed between pairs of activating cytokines tested. The HIV tat gene product was found to be functional in all cells, cotransfection of a tat expression vector transactivating expression from the LTR, with varying degrees of efficiency. In some cell lines the combination of an activating cytokine and tat resulted in an enhancement above that obtained by cotransfection of tat alone. In others, the level of CAT activity did not significantly change. Analysis of nuclear extracts from cytokine-treated cells further implicated the involvement of NFKB in the induction of HIV-1 gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The use of verbatim and schematic strategies in the recall of written stories by deaf and hearing children.

It is, in general, difficult to study cognitive structures in deaf children: in particular, the enquiry into the nature of their story-knowledge structures (or story schemata) is fraught with thorny methodological problems. While some of the available evidence would suggest that typical deaf children do not read "story schematically", theirs may be a problem of lack of access to (rather than absence of) such cognitive structures. On the other hand, it cannot be assumed a priori that cognitive structures are identical in deaf and hearing children. A study using a picture arrangement method is described, the results of which support the view that the story schemata of deaf children are basically similar to those of hearing children. Deaf children, however, may not utilise the presence of certain story features which, if presented to hearing children, lend strength and salience to the story line.

Attention↗