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Biomedical subjects

D Duncan

Publications and source records attributed to D Duncan.

At least 73 records · Page 4Linked to original sources
PubMed1985

Inactivation of rabbit muscle phosphoglycerate mutase by limited proteolysis with thermolysin.

Rabbit muscle phosphoglycerate mutase is inactivated by proteolysis with thermolysin. Inactivation is correlated with the breakage of one (or a few) bond(s) near one end of the polypeptide chain. There is no change in the overall conformation, quaternary structure or binding to Cibacron Blue on proteolysis. The possible analogy with the existence of a flexible tail in the yeast enzyme is discussed.

Animals↗
PubMed1985

Purification and preliminary characterization of phosphoglycerate mutase from Schizosaccharomyces pombe.

Phosphoglycerate mutase could be purified to over 95% homogeneity by a single step procedure involving elution from Cibacron Blue-Sepharose by a pulse of cofactor 2,3-bisphosphoglycerate. Although the enzyme has been isolated in only small quantities (c. 100 micrograms), gel filtration and sodium dodecylsulphate polyacrylamide gel electrophoresis indicated that it is monomeric with Mr approximately 23,000, an extremely low value for this enzyme. Preliminary investigations of the kinetic characteristics and the nature of important amino acid side chains have been undertaken.

Diacetyl↗
PubMed1985

Detection and characterization of monoclonal antibodies specific to IgE receptors on human lymphocytes by flow cytometry.

BALB/c mice were immunized with human lymphoblastoid cells (RPMI 8866 cells) expressing surface receptors for IgE (Fc epsilon R). Spleen cells from animals displaying high titres of anti-Fc epsilon R antibodies were fused with HGPRT-deficient NSI myeloma cells. Anti-Fc epsilon R antibodies were identified by a flow cytometric assay based on their ability to block the binding of IgE-coated fluorescent latex particles to Fc epsilon R-positive cells. Fourteen monoclonal hybridoma cell lines secreting antibody of the required specificity were amplified in tissue culture and then grown in the peritoneal cavity of BALB/c mice in order to obtain ascitic fluids with high antibody titres. The specificity of each monoclonal antibody (Mab) to lymphocyte Fc epsilon R was shown by the following observations: (i) the intact monoclonal antibody molecule or, in some cases, its F(ab')2 fragments blocked the binding of IgE to several Fc epsilon R(+) cell lines different from that employed for the initial immunization; (ii) the Mab bound directly to all the Fc epsilon R(+) cell lines tested, but not to several Fc epsilon R(-) cells as determined by indirect immunofluorescence; (iii) the binding of Mab to Fc epsilon R(+) cells was selectively blocked by IgE, but not by the other classes of Ig; and (iv) Mab had no effect on the binding of IgG to Fc gamma R on normal human peripheral blood mononuclear cells (PBMC).

Animals↗
PubMed1984

Comparative study of the neutral proteinases from fungi and actinomycetes using polyacrylamide gel electrophoresis.

Neutral proteinases from mycelial extracts of fungi and actinomycetes may be readily detected by polyacrylamide gel electrophoresis in which azocasein is incorporated into the gels. Most of the proteinases detectable at pH 6.5 were sensitive to both phenylmethanesulphonyl fluoride and to mercuric chloride. In all the species examined, except for one, the proteinase activities in the mycelial extracts increased during storage at 19 degrees C.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Atlanto-axial instability and spinal cord compression in children--diagnosis by computerized tomography.

Five children who were at risk for atlanto-axial instability underwent computerized tomography scanning of the cervical spine in flexion and extension to document the degree of bone instability and the presence or absence of spinal cord compression. Two patients had Morquio's syndrome, two had os odontoideum , and one had Klippel-Feil syndrome, and in all five the lateral radiographs of the cervical spine in flexion and extension were equivocal with regard to instability or were difficult to interpret because of the bone anomalies. The computerized tomography scan then provided a diagnosis by a non-invasion technique and quantitated the amount of compromise of the spinal cord by delineating flattening of the cord. The scan therefore helped the surgeon to decide if the spinal cord was at significant risk and if atlanto-axial fusion was advisable.

Atlanto-Axial Joint↗
PubMed1982

Visual screening: an alternative method for reducing stereotypic behaviors.

Visual screening, a mildly aversive response suppression procedure, was evaluated across two studies for its effectiveness in reducing topographically similar and dissimilar stereotypic behaviors of four developmentally disabled children. In the first study, a multiple baseline design across subjects and behaviors was used to assess the effectiveness of the procedure as a treatment for reducing the visual and auditory self-stimulatory responses of two 9-yr-old mentally retarded and behaviorally disturbed children. A multiple baseline design across subjects was used in the second study to evaluate the effectiveness of visual screening as a treatment for reducing stereotypic fabric pulling and self-mutilative ear bending, respectively, of two 13-yr-old mentally retarded, autisticlike adolescents. Long-term follow-up data for both studies were reported. The results suggested that visual screening was an easily administered, effective, and exceptionally durable treatment procedure for controlling a variety of stereotypic behaviors commonly associated with the developmentally disabled.

Adolescent↗
PubMed1981

The importance of osmolality fall and ultrafiltration rate on hemodialysis side effects. Influence of intravenous mannitol.

The decreases in serum osmolality as well as the rate of ultrafiltration during hemodialysis and the influence of each upon the side effects of this treatment were studied in 13 chronic stable dialysis patients. Mannitol (9 mosm/kg water) was infused in two out of four dialyses, in a double blind fashion. A solution of 5% glucose in water was used as control. 1 week after the treatment, there was no residual mannitol in the patients' serum (p less than 0.0005). The decrease in osmolality during dialysis was lower when the patients received treatment with mannitol than with placebo: 14.7 versus 25.0 mosm/kg water (p less than 0.001). The symptoms during dialysis were much less severe when the patients received mannitol (p less than 0.05). Analyzed separately, ultrafiltration rate had no effect on severity of symptoms during dialysis (p greater than 0.1). Decrease in serum osmolality during dialysis seems to be the most important factor in the genesis of dialysis symptoms in chronic stable dialysis patients and are counteracted by the infusion of an osmotically active substance such as mannitol, 1 g/kg/dialysis; this results in a slight increase in body weight between dialyses, and cannot be used routinely because of slow accumulation.

Adult↗
PubMed1981

A thought on the nature of psychoanalytic theory.

In this paper I suggest that much of recent experiment in analytic theory, even widely diverse approaches, has a common denominator the problem of the conceptual vacuum created by the shift away from a central creative position of the idea of psychic mechanisms. I try to illustrate, by comparing theories of Bion and George Klein, that this movement seems to point in the direction of considering now what is uniquely psychoanalytic about our theories. I content that what is unique about psychoanalytic theories is that they are involved in the experiential core-function of the applied science by becoming internalized and used symbolically to aid the analyst inwardly to endure persecutory anxiety and loss of the sense of objective reality, and so maintain the analytic position.

Consciousness↗
PubMed1978

Relative numbers of several types of synaptic connections in the substantia gelatinosa of the cat spinal cord.

The relative numbers of axo-dendritic, axo-axonic, dendro-axonic and dendro-dendritic synapses were determined by classifying and recording all such specialized contacts in sample areas of the substantia gelatinosa. The samples were taken from segments L1-L5 of the cat spinal cord. In the glomerular complexes 97% of all synapses were recorded as axo-dentritic. In substantia gelatinosa deprived of glomerular complexes by dorsal root section, 96.5% were axo-dendritic. The remainders were about equally divided between axo-axonic, dendro-dendritic and dendro-axonic synapses.

Animals↗
PubMed1978

Beclomethasone dipropionate dry-powder inhalation compared with conventional aerosol in chronic asthma.

In a double-blind study beclomethasone dipropionate inhaled as a dry powder in doses of 100 microgram four times daily and 150 microgram four times daily was compared with the conventional aerosol dose of 100 microgram four times daily in 20 outpatients with chronic asthma. Each of the three treatments was given for four weeks. The dry powder in a dose of 150 microgram four times daily had advantages over the other two treatments in terms of FEV1 and the number of exacerbations of asthma during the study. There were no adverse reactions to inhaling dry-powder beclomethasone. It was concluded that this new way of administering the drug was effective in chronic asthma, and should allow most patients with chronic asthma who cannot use conventional pressurised aerosols efficiently to benefit from inhaled corticosteroid treatment.

Adult↗
PubMed1976

Methadone blockade in the treatment of opiate addiction: a follow-up study.

This paper describes methadone blockade treatment of 50 opiate addicts. At follow-up, 36 patients were traced and interviewed. Results show that 89% of the 36 patients cooperated with the treatment programme, 88% had no new criminal convictions and 75% remained drug-free, apart from taking methadone during the follow-up period (mean, 12-5 months). Five of the 36 patients were free of all drug addictions, including methadone.

Adult↗
PubMed1976

Effects of water immersion to the neck on pulmonary circulation and tissue volume in man.

Utilizing the rebreathing of a gas mixture containing C2H2, C180, He O2, and N2, we obtained serial measurements of the pulmonary capillary blood flow (Qc), diffusing capacity per unit of alveolar volume (DL/VA), functional residual capacity (FRC), pulmonary tissue plus capillary blood volume (VTPC), and O2 comsumption (VO2) in five normal subjects under the following conditions: 1) 6 h of sitting, 2) 4 h of sitting while immersed in thermoneutral water to the neck, and 3) 4 h of lying in thermoneutral water to the neck. Water immersion (NI) was preceded and followed by 1-h prestudy and 1-h recovery periods. The measurements were made at 30-min intervals. Seated NI produced a fourfold increase in sodium excretion (UNaV), a 25-36% increase in Qc, a 45-59% increase in DL/VA, and a 30-36% decrease in FRC. This occurred as early as the 1st h of NI and persisted throughout the 4-h period of study. Throughout the seated control and NI periods, VO2, heart rate, and VTPC remained constant. During supine NI, Qc, HR, DL/VA, FRC, and VO2 did not differ significantly from supine prestudy. These date demonstrate that seated NI causes a significant increase of Qc and DL/VA which persists throughout the immersion period. Furthermore, the lack of change of VTPC suggests that the central vascular engorgement induced by seated NI is not accompanied by extravasation of fluid into the pulmonary interstitial space.

Adolescent↗