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Biomedical subjects

C Olson

Publications and source records attributed to C Olson.

At least 19 recordsLinked to original sources
PubMed1992

Variations of response of cattle to experimentally induced viral papillomatosis.

The common bovine papilloma virus type 1 has been widely used to stimulate basic research on papilloma viruses involved in some cancers of mankind. The usually benign neoplasms of cattle caused by bovine papilloma viruses are frequent clinical problems for veterinarians. Approximately 240 experimentally induced cutaneous fibropapillomas on 8 susceptible calves had a uniform appearance of initial growth. Their size and duration ranged from about 2 months to nearly 3 years but were similar for the multiple papillomas of each calf. Sequential biopsies were done to examine the histologic changes and existence of viral antigen. Veterinarians in practice may encounter the common fibropapillomas caused by bovine papilloma virus 1 and 2 as well as papillomas with no fibromatous element. These types may develop on teats of cows in some herds. Interdigital papillomas cause a problem in some dairy herds and a virus suspected but not yet found. Prophylactic vaccination with a formalin-killed vaccine will protect against infection with bovine papilloma virus 1 and 2.

Animals↗
PubMed1992

Impact of a clinic-based growth monitoring programme on maternal nutrition knowledge in Lesotho.

An evaluation of the impact of a nationwide clinic-based growth monitoring (GM) programme was done in Lesotho to determine if clinic attendance was associated with improved maternal knowledge of weaning practices and diarrhoea. A total of 907 mothers from eight clinics were included in the study. Our results showed that mothers who had attended the clinics knew more about the appropriate timing for introducing animal protein-rich foods in the child's diet and about the use of oral rehydration salts for diarrhoea, than those who had not. The difference in knowledge between previous clinic attendants and new attendants was particularly marked among mothers with less than secondary schooling and mothers with young babies (less than 6 months). From observation in the clinics, we believe that group nutrition education, although it was not integrated with growth monitoring, was probably responsible for the positive association between clinic attendance and maternal knowledge. Prior clinic attendance was not specifically associated with improved knowledge about feeding during diarrhoea or the need to stop breastfeeding gradually. These need to be better incorporated into present clinic nutrition education. Whether improvements in growth monitoring would further significantly improve nutrition education remains to be seen.

Adult↗
PubMed1992

Activation defects caused by mutations in Escherichia coli rpoA are promoter specific.

Escherichia coli RNA polymerases containing mutated alpha subunits were tested for their ability to respond to three different positive regulators (activators) in vitro. The two alpha (rpoA) mutants, alpha-256 and alpha-235, have deletions of the C-terminal 73 and 94 amino acids, respectively. In runoff transcription assays catalyzed by reconstituted holoenzyme, the effects of the mutations on each of three promoters tested were different: activation of the lambda pRM promoter by cI protein (repressor) was nearly normal, activation of the lambda pRE promoter by cII protein was reduced approximately fivefold, and direct activation of the trpPB promoter of Pseudomonas aeruginosa was completely inhibited. We also found that the reconstituted mutant enzyme was defective in recognition of trpPI in the absence of activator. The differential responses of the three promoters to their activators in the presence of the mutant enzymes indicate that the location of an activator-binding site does not by itself determine the region of RNA polymerase with which the activator interacts.

Binding Sites↗
PubMed1991

Structures of bovine and human papillomaviruses. Analysis by cryoelectron microscopy and three-dimensional image reconstruction.

The structures of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 1 (HPV-1) were determined at 2.5 nm resolution by cryoelectron microscopy and three dimensional image reconstruction techniques. As expected, the reconstructions showed that both viruses consist of a T = 7 icosahedral capsid (approximately 60 nm in diameter) which surrounds a nucleohistone core. The capsid morphologies of the two viruses are nearly indistinguishable. Each capsid consists of a shell layer (approximately 2 nm thick) of nearly continuous density from which capsomers project radially to a maximum height of approximately 5.8 nm. The five-coordinate (pentavalent) and six-coordinate (hexavalent) capsomers both exhibit distinct five-fold axial symmetry as was observed for SV40 and polyoma viruses. Thus, both genera (papilloma and polyoma) of the papovavirus family have now been shown to have the characteristic "all-pentamer" capsid construction. BPV-1 and HPV-1 capsomers consist of a thick (8.6 nm diameter) trunk that broadens distally to form a regular five-pointed, star-shaped head, and proximally to create the shell layer where capsomers associate. A cylindrical channel (approximately 2.8 nm diameter) extends along the axis of each capsomer from the interior of the virus to a point approximately half way to the capsomer surface. Computationally sectioned views of individual capsomers displayed at decreasing radii show that each of the five capsomer subunits (in both pentavalent and hexavalent capsomers) makes a pronounced (30 degrees) left-handed twist just above the outer surface of the capsid shell. Similar views of the reconstructions also clarify the morphology of intercapsomer contacts. For example, they show how hexavalent capsomers coordinate six neighboring capsomers despite the fact that they contain only five subunits. The system of intercapsomer contacts is indistinguishable in BPV-1 and HPV-1, but quite different from that reported for polyoma virus capsids assembled in vitro from the major capsid protein, VP1 (D. M. Salunke, D. L. D. Caspar, and R. L. Garcea. 1989. Biophys. J. 56:887-900). Thus, because both polyoma and papilloma viruses have all-pentamer capsids, it appears that intracapsomer subunit-subunit interactions which stabilize pentameric capsomers are better preserved evolutionarily than those involved in capsomer-capsomer contacts.

Animals↗
PubMed1991

Identification of linear epitopes of the BPV-1 L1 protein recognized by sera of infected or immunized animals.

Sera from cattle that had been inoculated with BPV-1 virions or with recombinant L1 proteins and serum from a rabbit that had been immunized with SDS-denatured virions were evaluated for their reactivity with 466 overlapping synthetic peptides corresponding to 95% of the BPV-1 L1 protein. The late serological response of cattle to both intact virions and recombinant L1 proteins exhibited a similar profile of reactivity with approximately 70% (7 of 10) of L1 antigenic sites. However, the L1 serological response of the rabbit to SDS-denatured virions exhibited a significant difference from bovine serum antibodies in the profile of epitopes recognized, including a relative lack of response to major bovine epitopes located between L1 amino acids (AAs) 300-400. Importantly, only the sera from animals inoculated/immunized with intact virions was capable of neutralizing BPV-1 infectivity of murine C127 cells, suggesting that nonlinear epitopes are important for papillomavirus neutralization.

Amino Acids↗
PubMed1990

Microcomputer-based data acquisition system for clinical research.

We have described a computerized data acquisition system for clinical investigation that can record over fifty physiologic variables from up to twenty-four electronic monitors. The information is acquired by a personal computer using RS-232C serial communications and analog-to-digital conversion. In its present configuration the system records information from a Spacelabs 500 series physiologic monitor, Hewlett-Packard physiologic monitor with the Careport computer interface, SARA mass spectrometer, Nellcor pulse oximeter, Neurotrac processed EEG, Lawrence cardiac output monitor, Hewlett-Packard capnometer, and Bourns spirometer. The software can be easily modified to accommodate other physiologic monitors. The system records parameter or waveform information and writes the data into a file that can be accessed by commercially available graphical and statistical packages. The data acquisition system is easy to use, transportable, and inexpensive.

Humans↗
PubMed1990

Maternal birthing positions and perineal injury.

A study to evaluate the relationship between maternal birthing position and perineal outcome was undertaken on 335 patients in a rural family physician's practice whose babies were delivered vaginally between December 1980 and December 1988. The most common birthing position used by the women was the semi-sitting position in the birthing bed (44%, n = 146). Ninety-four women (28%) gave birth from the conventional lithotomy position, 80 (24%) used the birthing chair, and less than 5% used a side-lying position. Almost 30% of the women gave birth with intact perineum; the incidence of episiotomy was 44%. The use of a particular position for delivery varied with parity, and multiparous women used the semi-sitting position in the birthing bed more frequently than did primiparous women. There was no statistically significant relationship between birthing position and perineal outcome for primiparous women. A statistically significant relationship between delivery position and perineal outcome was found for multiparous women. Multiparous women using the birthing bed were more likely to have less perineal trauma than women giving birth on the delivery table.

Adult↗
PubMed1989

Quadriceps strength training using two forms of bilateral exercise.

The purpose of this study was to determine the effectiveness of quadriceps strength training in 15 women using bilateral constant resistance computerized exercise equipment that enabled only concentric contractions. To facilitate this investigation, data from an experimental control group (n = 14), using bilateral variable resistance exercise equipment which enables both concentric and eccentric muscle contractions, and a nonexercise control group (n = 17) were incorporated into the study design. Through a random selection process, subjects were assigned to one of three groups that participated in this 10-week study. Analysis, including univariate and multivariate statistical techniques, revealed no significant changes in strength between the two experimental groups. However, compared with the nonexercise group, there were significant increases in strength in the experimental exercise groups; yet, these increases were significant in both groups only on the right legs. In addition, the development of transient knee pain in two subjects engaged in both concentric and eccentric exercise training required their removal from the study. This finding, in concert with previous experimental evidence of an association between eccentric exercise and the development of transient pain, must be integrated into future studies. Results suggest that further investigation is necessary to reveal the neurologic or biomechanical factors which may result in unequal training stimuli to the limbs with bilateral strength training on various types of equipment.

Adult↗
PubMed1986

Ventricular function and morphology in chick embryo from stages 18 to 29.

We evaluated wet and dry ventricular and embryo weights, hemodynamic parameters of ventricular function, and myocardial myocyte organelle composition in the developing chick embryo. Phasic and dP/dt ventricular pressure were measured with a servo null pressure system, and phasic, mean, and dV/dt dorsal aortic velocities were measured with a 20-MHz pulsed-Doppler meter. Ventricular and embryo weight increased geometrically with development, but at different rates, so that the ventricle-to-embryo weight ratio decreased from 0.02 to 0.001 just prior to hatching. Ventricular systolic and end-diastolic pressure increased from 1.31 +/- 0.05/0.33 +/- 0.03 mmHg at stage 18 to 3.45 +/- 0.10/0.82 +/- 0.03 mmHg at stage 29, while dP/dt increased from 23.04 +/- 1.32 to 79.55 +/- 3.69 mmHg/s over the same period. Dorsal aortic dV/dt increased from 878 +/- 17 to 2.076 +/- 65 mm/s2 from stage 18 to 29. Myocyte percent volume of myofibrils increased from 16.7 +/- 0.9% at stage 18 to 23.6 +/- 1.1% at stage 27 and diminished to 18.4 +/- 0.8% at stage 29. Mitochondrial percent myocyte volume remained constant at about 11%. These data define the parameters of normal ventricular function and morphology during embryonic development in the chick.

Animals↗
PubMed1986

Clinical and grid predictions of inconsistencies in individuals' personal constructs.

An experiment was conducted to determine the ability of the coordinate grid to assess logical inconsistencies that characterize individuals. Previous research has shown the grid differentiates groups predicted to vary in inconsistency. In the present study therapists' were significantly likely to differentiate real from bogus grid reports of their clients' inconsistencies. Results suggest the grid does assess inconsistencies that characterize the individual.

Adaptation, Psychological↗
PubMed1985

Protein synthesis in rabbit reticulocytes. A study of the roles of Co-eIF-2, Co-eIF-2A80, and GDP in peptide chain initiation.

The roles of Co-eIF-2, Co-eIF-2A80, and GDP in ternary complex and Met-tRNAf X 40 S initiation complex formation were studied. 1) Partially purified eukaryotic initiation factor 2 (eIF-2) (50% pure) preparations contained 0.4-0.6 pmol of bound GDP/pmol of eIF-2. eIF-2 purity was calculated from ternary complex formation in the absence of Mg2+ and in the presence of excess Co-eIF-2. 2) In the absence of Mg2+, approximately 30% of the potentially active eIF-2 molecules formed ternary complexes, and both Co-eIF-2 and Co-eIF-2A80 were equally effective in full activation of the eIF-2 molecules for ternary complex formation. 3) In the presence of Mg2+, approximately 10% of the potentially active eIF-2 molecules formed ternary complexes in the absence of ancillary factors, and the ancillary factors Co-eIF-2A80 and Co-eIF-2 raised the incorporation to 20 and 50% of the eIF-2 molecules, respectively. 4) In the absence of Mg2+, [3H]GDP in preformed eIF-2 X [3H]GDP was readily displaced by GTP during ternary complex formation. 5) In the presence of Mg2+, [3H]GDP remained tightly bound to eIF-2 and ternary complex formation was inhibited. Co-eIF-2, but not Co-eIF-2A80, was effective in promoting [3H]GDP displacement and the former was more effective in promoting ternary complex formation than the latter. 6) eIF-2 X [3H]GDP was converted to eIF-2 X [3H] GTP by incubation in the presence of nucleoside-5'-diphosphate kinase and ATP, but the eIF-2 X [3H]GTP thus formed did not bind Met-tRNAf in the presence of Mg2+ and required exogeneous addition of Co-eIF-2 and GTP for ternary complex formation and GTP displacement. 7) In the absence of Mg2+, the increased ternary complex formed in the presence of eIF-2 X [3H] GDP and Co-eIF-2A80 (with accompanying loss of [3H] GDP) was inactive in a subsequent reaction, which involves Met-tRNAf transfer to 40 S ribosomes (in the presence of Mg2+), and required trace amounts of Co-eIF-2 for such activity. Based on the above observations, we have suggested a two-step activation of eIF-2 molecules by the Co-eIF-2 protein complex for functional ternary complex formation. One of these steps involves the Co-eIF-2A component of Co-eIF-2. This activation results in stimulated Met-tRNAf binding to eIF-2 and is most apparent in the absence of Mg2+ and with aged eIF-2 molecules.(ABSTRACT TRUNCATED AT 400 WORDS)

Eukaryotic Initiation Factor-2↗
PubMed1985

Synthesis and structure of proteoglycan core protein.

Studies of the structure and synthesis of cartilage proteoglycan core protein have been carried out. Deglycosylation of completed, secreted proteoglycan by HF-pyridine treatment yielded an intact homogeneous core protein of approximately 210,000 daltons, with a blocked amino-terminus. Greater than 95% of chondroitin sulfate chains and 80% of N- and O-linked oligosaccharides were removed by the procedure, which made the product an excellent xylosyltransferase acceptor. Little alteration of core protein structure occurred during the HF-pyridine treatment as shown by complete immunoreactivity with antiserums prepared against hyaluronidase-digested proteoglycan. In other studies, the initially synthesized precursor for proteoglycan core protein was found to be approximately 376,000 daltons and localized to the rough membrane fractions. This precursor already contained N-linked oligosaccharides, and was also able to accept xylose, thereby initiating chondroitin sulfate chains. The precursor was translocated intact in an energy-dependent manner to smooth membrane-Golgi fractions where further processing of high mannose type of oligosaccharides and addition of glycosaminoglycan chains occurred. The subcellular distribution pattern of the chondroitin sulfate-synthesizing enzymes corroborated the proposed topological modifications of the proteoglycan core protein precursor.

Animals↗