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Biomedical subjects

J Morgan

Publications and source records attributed to J Morgan.

At least 217 records · Page 12Linked to original sources
PubMed1989

Emergency planning for technology-assisted children.

Development of emergency systems is essential to ensure a safe home environment for technology-assisted children. Defined as combinations of circumstances or the resulting states that call for immediate action, assistance, or relief, emergencies may arise related to health, equipment, or environmental situations. Based on the philosophy that emergency services should be planned in advance of emergencies for technology-supported individuals, systems for each area of planning are outlined.

Child↗
PubMed1988

Mechanism of human monocyte activation via the 40-kDa Fc receptor for IgG.

It is shown that a mAb specific for the human 40-kDa FcR (FcRII) leads to activation of human monocytic cells but that extensive cross-linking of the receptor is required. Calcium mobilization can be induced in immature monocytic cells (undifferentiated U937 cells) and peripheral blood monocytes with an intact IgG1 anti-FcRII antibody (CIKM5) but not by F(ab')2 fragments of this antibody. The intact antibody can bind in a tripartite manner by its two F(ab') sites and its Fc-binding site whereas the F(ab')2 fragments of this antibody can only bind in a divalent fashion. A rise in intracellular free calcium ion concentration occurs when F(ab')2 fragments are cross-linked with F(ab')2 anti-mouse Ig indicating that more extensive cross-linking of FcRII is required rather than an obligatory requirement for an Fc-FcRII interaction. Calcium mobilization in response to intact or cross-linked F(ab')2 fragments of CIKM5 is associated with superoxide production only in IFN-gamma-primed peripheral blood monocytes and IFN-gamma differentiated U937 cells indicating that the activation signal produced via FcRII is inadequate to fully stimulate non-"primed" cells. A second mAb reactive with FcRII (2E1) does not cause calcium mobilization in monocytes or U937 cells, and partially blocks the effects of CIKM5. 2E1 also blocks CIKM5 superoxide production in IFN-gamma-primed monocytes and differentiated U937 cells. This may be explained in part by the fact that 2E1 is an IgG2a antibody and can only participate in bipartite binding with FcRII. When 2E1 is cross-linked with F(ab')2 anti-mouse Ig there is a small calcium response. This does not cause superoxide generation in IFN-primed monocytes but does do so in IFN-gamma differentiated U937 cells. FcRII is also expressed on granulocytes and some B cells but the effects of cross-linking the receptor on these cells differ from those seen in monocytes.

Antibodies, Monoclonal↗
PubMed1988

A nondenaturing vertical isoelectric focusing polyacrylamide slab gel system suitable for silver staining and electrophoretic blotting.

We have devised a nondenaturing vertical isoelectric focusing (IEF)-polyacrylamide gel electrophoresis (PAGE) system which is amenable to silver staining and electroblotting. Apart from being accessible, inexpensive, and simple to use, this new methodology overcomes problems inherent in current IEF methods, for example, pH gradient drift, nonuniform cooling, restricted sample volume, and inability to perform electroblotting. Two photopolymerization gel formulas were derived: a 5% acrylamide formula using bisacrylamide (Bis) as the crosslinker and a 6% acrylamide formula using diallyltartdiamide (DATD) as the crosslinker. The 5% acrylamide Bis gel gave excellent resolution and separation of proteins whereas the 6% acrylamide DATD gel expanded slightly during silver staining, resulting in mild band distortions. At least 80 ng of protein per band could be detected by the silver staining protocol devised. Both the DATD and the Bis gels were suitable for electroblot transfer. Parameters to ensure the optimum conditions for reproducible, high resolution vertical IEF-PAGE are described. IEF-PAGE silver staining and electroblotting procedures and silver staining of the nitrocellulose electroblot procedures are also described. The advantages of this methodology over previously published methods are discussed.

Animals↗
PubMed1988

Regional localization of the autosomal dominant polycystic kidney disease locus.

The localization of the autosomal dominant polycystic kidney disease locus (PKD1) within an array of anonymous polymorphic DNA sequences on chromosome 16 band p13 was determined by multipoint mapping. Nine polymorphic DNA markers, including two hypervariable sequences, were used to study 19 PKD1 and 21 reference families. PKD1 was found to lie proximal to the 3' and 5' hypervariable regions of alpha-globin and distal to the anonymous sequence CRI-0327. Somatic cell hybrid mapping places PKD1 within the region 16p13.11-16pter. The availability of an array of linked markers which bracket the PKD1 locus provides a framework for further attempts to identify the PKD1 gene and offers an improved method of presymptomatic diagnosis of the disease.

Animals↗
PubMed1988

Carriage of Neisseria meningitidis: investigations in a military establishment.

A prevalence study of personnel on a Royal Naval Air Station revealed that 23.0% of 2479 personnel were carrying a meningococcus. Selected groups of personnel were subsequently swabbed monthly for a year. We have shown that it is only by repeated swabbing and the use of optimal methods including enrichment media that one can have a hope of identifying the 'true' carriage rate. A presumed virulent strain of Neisseria meningitidis B15 P1.16 was repeatedly isolated from three personnel who remained well, as did their colleagues both at their work place and socially. The study served to emphasize our lack of knowledge of the virulence factors associated with N. meningitidis.

Adult↗
PubMed1988

Diameters and dry weights of tree shoots: effects of Young's modulus, taper, deflection and angle.

The structural theory for cantilever beams was used to calculate the diameters and dry weights of wood that unbranched shoots must produce to support their own weights. The study was done on Picea sitchensis (Bong.) Carr., Pinus contorta Dougl., Larix decidua Mill. and Betula pendula Roth. syn. verrucosa Ehrh. The weights of wood increased in a non-linear fashion with increase in shoot length. A large investment in wood (as measured by diameter and dry weight) was required to maintain a small endpoint deflection (1-5% of the length). By contrast, the degree of linear taper had only a small effect on support costs, as did the Young's modulus of the wood (over the range 1-4 GPa) and the angle of the shoot from the horizontal (over the range 0-45 degrees ). Current year's shoots on young trees of P. sitchensis and P. contorta incur a high support cost in order to maintain small (1-5%) deflections throughout the year: similar shoots of L. decidua and B. pendula have smaller support costs because they deflect by about 20% after leaf expansion in spring.

Journal Article↗
PubMed1988

Support costs of different branch designs: effects of position, number, angle and deflection of laterals.

The structural theory for cantilever beams was used to calculate the dry weight of wood that a branch of Picea sitchensis (Bong.) Carr. must produce to support its own weight plus that of laterals in different positions and numbers, and with different angles and deflections. The endpoint of the branch was maintained at 2% of its length, and constant values or functions (measured on real branches) were assumed for Young's modulus, taper and self weights of wood and foliage. Support costs (branch wood dry weights) were minimized when laterals were positioned so that the center of gravity was close to the base of the branch, and when the branch was angled upward from the horizontal. Small savings in support costs also resulted when laterals were not forward pointing, were angled upward and had endpoint deflections of at least 20% of their length.

Journal Article↗
PubMed1988

Natural killer cell activity in asbestos workers. Interactive effects of smoking and asbestos exposure.

Both the numbers and function of natural killer (NK) cells in 60 were evaluated in asbestos cement workers grouped by smoking history and chest roentgenogram findings (ILO profusion scores less than 1/0 or greater than or equal to 1/0, or isolated pleural plaques). Worker and control subjects who smoked had smoking histories of less than 27 pack-years, a level of smoking lower than that previously determined to adversely affect NK function. Asbestos workers who did not smoke had percentages and total numbers of NK cells and NK function not different from that of nonsmoker control subjects. Workers who smoked and had evidence of asbestosis (ILO profusion category greater than or equal to 1/0) had significantly lower total numbers of NK cells and mononuclear cell NK activity than did smoker control subjects or smokers with pleural plaques only (p less than or equal to 0.05). Numbers of NK cells and NK cell function were not decreased in either of the asbestos-exposed smoking groups without asbestosis when compared to nonsmoker controls. We conclude that smoking and asbestos exposure interact to decrease mononuclear cell NK function in workers with levels of asbestos exposure sufficient to induce asbestosis. This finding may explain in part the previously reported synergistic effect of smoking and asbestos exposure on the risk of lung cancer. Furthermore, the data presented here clarify previous conflicting reports on NK function where asbestos exposed groups have not been stratified for analysis of data.

Adult↗
PubMed1988

Uptake of antibody directed cytotoxic liposomes by CD3 on human T cells.

Using polyclonal human T cells and anti-CD3 monoclonal antibodies we have shown that small unilamellar liposomes covalently coupled with protein A become bound to T cells and not to B cells and that the binding was a specific liposome-antibody-receptor interaction. Intracellular delivery of liposome contents was demonstrated by the use of encapsulated carboxyfluorescein and flow cytometry and the transfer of membrane-bound liposomal carboxyfluorescein was virtually complete in 30 min. Liposomes containing methotrexate inhibited the growth of PHA-stimulated peripheral blood lymphocytes by 90%, after 48 h incubation. Potential applications are proposed in the study of the behaviour of surface membrane components and in T cell depletion and purging of bone marrow.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Effectiveness of individualized long-term therapy with niacin and probucol in reduction of serum cholesterol.

A retrospective analysis was made of the results of the individualized office management of hypercholesterolemia in 37 patients (25 male, 12 female) with severe atherosclerosis (n = 35) or a predisposition to it (n = 2). The effects of diet instruction, diet and a niacin supplement, and diet plus the niacin supplement and probucol were assessed. Diet alone (n = 37) was prescribed for an average of 4.8 years; diet plus niacin (n = 37) for an average of 2.0 years; and diet plus niacin and probucol (n = 19) for an average of 2.9 years. Each patient served as his or her own control. The maximum serum cholesterol at the beginning of the diet period was 8.69 +/- 2.15 mmol/L (336 +/- 83 mg/dL) (mean plus or minus standard deviation; n = 37). The goal cholesterol was less than 5.20 mmol/L (200 mg/dL). On diet alone the cholesterol level fell to 7.21 +/- 1.27 mmol/L (279 +/- 49 mg/dL) (P less than .001); and goal cholesterol was reached by 12 of 37 patients (32.4 percent), but was maintained in none. On adding niacin, the mean cholesterol fell to 6.21 +/- 1.16 mmol/L (240 +/- 45 mg/dL) (P less than .001). The goal cholesterol was reached in 22 of 37 patients (59.4 percent), but was maintained in only 7 of 37 (18.9 percent). Nineteen of 37 patients on diet plus niacin also received probucol. Goal cholesterol was reached in 14 of 19 patients (73.6 percent), and was maintained in 11 of 19 (57.9 percent).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Molecular cloning and expression of a human B-cell growth factor gene in Escherichia coli.

A human B-cell growth factor (BCGF) (12 kilodaltons) supports the clonal proliferation of B lymphocytes. A clone was isolated that contained the proper structural sequence to encode biologically active, 12-kilodalton BCGF in Escherichia coli and to hybridize to a specific messenger RNA, identified by in vitro translation in Xenopus laevis oocytes. A relatively hydrophobic region of 18 amino acids was found at the amino terminal of the 124-amino acid-long polypeptide. The carboxyl terminal is composed of at least 32 amino acids that are derived from nucleotide sequences bearing significant homology to the Alu repeat family.

Amino Acid Sequence↗
PubMed1987

Serotonin uptake in blood platelets of Duchenne muscular dystrophy patients.

Serotonin (5-HT) uptake was studied in the blood platelets of 10 patients with Duchenne-type muscular dystrophy (DMD) and 7 age-matched controls. Vmax (maximum number of uptake sites) of platelet 5-HT uptake in the DMD patients was significantly less than that of the normal controls. There was no difference in the affinity for 5-HT (Km) between the two groups. There was a significant negative correlation between serum creatine kinase activity and Km of 5-HT uptake in blood platelets of these patients. However, no correlation was found between Km or Vmax and ambulatory status of DMD.

Adolescent↗
PubMed1987

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study.

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗