Search PubMed⌕ Search

Biomedical subjects

J Edwards

Publications and source records attributed to J Edwards.

At least 253 records · Page 14Linked to original sources
PubMed1989

Plasma nitrendipine concentrations in elderly normotensive volunteers after single and multiple dosing.

An acute and chronic dosing pharmacokinetic study of the calcium antagonist nitrendipine was carried out in 8 normotensive volunteers (mean age 80.1 +/- 3.4 years) to investigate if drug accumulation occurred in the elderly. Subjects received 10 mg nitrendipine once daily by mouth for 8 days. Plasma nitrendipine concentrations before administration and at 0.5, 1, 2, 4, 6 and 8 hours after dosing were measured after the first and last dose. Comparison of the pharmacokinetic data from Days 1 and 8 failed to show any evidence of nitrendipine accumulation in these elderly subjects.

Aged↗
PubMed1989

Membrane N-acetylglucosamine: expression by cells in rheumatoid synovial fluid, and by pre-cultured monocytes.

After 21-48 h in culture, 2-8% of human peripheral blood monocytes strongly express terminal N-acetylglucosamine (GlcNAc) on their membranes. This can be detected with a monoclonal antibody selected for binding to asialo-agalacto-fetuin, and is eliminated by incubating the cells in pure N-acetylglucosaminidase. Expression of GlcNAc is transient, and can no longer be detected by day 4. These cells are a subset of macrophages since they are positive for non-specific esterase and stained by the monoclonal antibody EBM 11. GlcNAc-positive cells showing double staining with monoclonal antibodies UCHM1 and RFD7 were detected. Their numbers were not influenced by the addition of GM-CSF, IFN-gamma, 1,25-(OH)2 cholecalciferol or indomethacin. Macrophages which give membrane staining for terminal GlcNAc were also found in rheumatoid synovial fluid, and in synovial tissue, though in the peripheral blood their frequency was the same in samples from normal donors and from patients with rheumatoid arthritis. Immunoblots of 24-48-h monocyte cultures or of fresh synovial fluid cells using the anti-GlcNAc monoclonal, show the anticipated agalactosyl IgG heavy chains, and an additional band of 70-80kDa.

Acetylglucosamine↗
PubMed1989

Effect of intermittent pneumatic compression on lower limb skin perfusion.

Transcutaneous oxygen (tcPO2) and carbon dioxide (tcPCO2) measurements were used before, during, and after intermittent pneumatic compression (IPC) to assess lower limb skin perfusion in 21 healthy adult volunteers and 23 elderly patients. The temperature of the sensors was set at 44 degrees C during calibration and maintained throughout all tests. Resting tcPO2 was significantly lower (p less than 0.01) in patients than in controls. In all subjects tcPO2 decreased and tcPCO2 increased during compression. Patients showed a highly significant increase (p less than 0.001) in tcPCO2 during and after the treatment. Results of this study indicate that the symptomatic improvement, in peripheral vascular disease and wound healing following IPC, is not due to improved skin perfusion or enhancement of oxygenation and CO2 removal.

Aged↗
PubMed1989

Growth of fresh-frozen pulmonary allograft conduit in growing lambs.

To investigate the fate of cryopreserved pulmonary conduit allografts, an experimental model was used in lambs. The lambs underwent resection of the pulmonary trunk and valve to the level of the bifurcation of the pulmonary arteries and then were replaced by cryopreserved (CryoLife, Incorporated, Laboratories) pulmonary conduit allografts obtained from lambs of similar size. Lambs were operated on at 4 weeks of age and followed up with cardiac catheterization and cineangiography every 3 months for a period of 18 months. Lambs were electively sacrificed in the following order: two at 1 month, two at 3 months, one at 6 months, two at 12 months, and five at 18 months. To assess the structure of the conduit tissue, sections for light microscopy were obtained from the proximal, midportion, and distal ends of the conduit. While the lambs grew from a weight of 11.7 kg at the time of implant to more than 70 kg at 18 months, the diameter of the pulmonary conduit distended from 16 mm at the time of implant to 17.7, 19.1, 24.9, 34.3, and 33.7 mm at 1, 3, 6, 12, and 18 months, respectively. The length of the conduit also extended from an original inner length of 25 mm and an original outer length of 32 mm to the following dimensions: inner lengths of 27.9, 32.7, 38.8, 43.6, and 45.3 mm, respectively, at 1, 3, 6, 12, and 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Urinary MHPG, platelet 3H-imipramine binding and symptomatology in depression: an exploratory study of clinical heterogeneity.

Urinary MHPG concentrations and platelet 3H-imipramine binding (Bmax, Kd) were measured in 20 psychiatric inpatients with diagnoses of major depressive disorder. Clinical assessments were performed using the Present State Examination (PSE) interview, and several dimensions of symptomatology were constructed on the basis of the PSE items. There was a significant positive relationship between Bmax and items reflecting both psychomotor retardation and anxiety. Urinary MHPG bore a comparatively complex nonlinear relationship to Bmax and to the psychomotor retardation symptom dimension. Urinary MHPG also showed an inverse, curvilinear correlation with certain neurotic symptoms. The implications of these findings are briefly discussed in the light of the "dysregulation" hypothesis of affective disorder.

Adult↗
PubMed1988

Immunological changes associated with a successful outcome of pollen immunotherapy.

Changes in immunological measurements thought to be important in the mechanism of immunotherapy for hay fever were related to objective measurements of treatment outcome. Antigen-specific IgE and IgG, and T suppressor cell status, using monoclonal antibodies and a specific functional assay, were measured before and after immunotherapy. Treatment outcome was assessed using nasal and conjunctival challenge tests. Seventeen subjects received immunotherapy for 6 months. Nine showed a decrease in nasal and/or conjunctival sensitivity, compared with 2 of 13 control subjects (P less than 0.05). Subjects responding to immunotherapy had a significantly higher post treatment IgE level and a higher pre- and post-treatment IgG level than non-responders and controls. Immunotherapy had no effect on suppressor cell status.

Adolescent↗
PubMed1988

Effect of actinomycin D and cycloheximide on replication of Sindbis virus in Aedes albopictus (mosquito) cells.

Production of Sindbis virus in the presence of transcription and translation inhibitors was examined in three Aedes albopictus cell lines. Addition of cycloheximide to heat-resistant Sindbis virus (SVHR)-infected mosquito cells arrested viral RNA synthesis completely, in contrast to the effects of this drug on virus-infected vertebrate cells. Production of mature virus by both SVHR (a variant commonly used as a wild-type virus) and SBamr (a mutant which is resistant to the effects of 18 h of pretreatment of vertebrate cells with actinomycin D) in mosquito u4.4, C6-36, and C7-10 cells was inhibited by 2 h of pretreatment with actinomycin D. Pretreatment with this drug for 2 h slightly enhances virus production in vertebrate cells. Treatment of mosquito cells with actinomycin D resulted in shutoff of SVHR RNA synthesis. The mutant SBamr was able to overcome the effects of actinomycin D on viral RNA synthesis and produced both 26S and 49S RNAs, even though no viral structural proteins or mature particles were produced in the presence of the drug. This result suggests that, in the presence of actinomycin, the nonstructural genes of SBamr are translated sufficiently to allow for RNA synthesis but that 26S RNA may not be translated to an extent that allows significant virus production. These data demonstrate that host components are involved in at least two distinct steps in the production of Sindbis virus in mosquito cells: (i) production of viral RNA and (ii) synthesis of viral structural polypeptides.

Aedes↗
PubMed1988

Human immunodeficiency virus and female prostitutes, Sydney 1985.

One hundred and thirty two female prostitutes and 55 non-prostitutes who were tested for antibodies to human immunodeficiency virus (HIV) were surveyed by questionnaire at this centre. The two groups were well matched for age and were very similar in other except for numbers of their sexual partners. Questions were asked about drug taking, sexual practices, general health, and episodes of sexually transmitted diseases (STDs). None of the women in the survey was found to be seropositive, but both groups were found to be seriously at risk of HIV infection through using intravenous (IV) drugs, having unprotected sexual intercourse with men who used IV drugs, having unprotected sexual intercourse with bisexual men, or exposure to several STDs.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Exchange of labeled bicarbonate and carbon dioxide with erythrocytes suspended in an elutriator.

An elutriator was used to study exchange of labeled CO2 and bicarbonate with erythrocytes. Rabbit erythrocytes were suspended by centrifugation in a stream of fluid and exposed to transient injections of an extracellular indicator (125I-albumin or 22Na+), a water indicator (3H2O), and H14CO3- and/or 14CO2. Diffusion of indicators into erythrocytes was judged by comparison of initial concentrations of diffusible and extracellular indicators in the elutriator outflow. It was possible to conduct these experiments at normal hematocrits because any carbonic anhydrase released from erythrocytes by hemolysis was washed away in the elutriator flow, and ambient pH, PO2, and PCO2 were kept constant by the inflow of fresh fluid. Equilibration of HCO3- with erythrocytes was complete during the 7- to 10-s transit time through the chamber. After this exchange was irreversibly inhibited by the anion exchange inhibitor, DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid), addition of carbonic anhydrase (100 mg/dl) accelerated exchange, but acetazolamide (20 mg/dl) was without effect. These observations were consistent with the absence of carbonic anhydrase on the surface of the erythrocytes.

Animals↗
PubMed1988

The effects of race and body habitus on bone mineral density of the radius, hip, and spine in premenopausal women.

The incidence of osteoporosis and fractures of the hip are diminished in blacks and in obese subjects. To determine whether bone mass is increased in them, bone mineral density (BMD) of the lumbar spine, trochanter, and femoral neck was measured by dual photon absorptiometry in 89 nonobese white and 51 nonobese black women, all of whom were within 30% of their ideal body weight and between the ages of 20 and 50 yr, and in 21 obese white women and 21 obese black women, all of whom weighed 30% on more than their ideal body weight and were in the same age range. The BMD of the mid radius was also measured by single photon absorptiometry. The mean BMD of the mid radius was higher in black than in white nonobese women [0.73 +/- 0.01 (+/- SE) vs. 0.70 +/- 0.01 g/cm2; P less than 0.01] and was not altered by obesity in either group. The mean BMD was higher in the black than in the white nonobese women at the lumbar spine (1.23 +/- 0.02 vs. 1.16 +/- 0.01 g/cm2; P less than 0.01), trochanter (0.78 +/- 0.02 vs. 0.72 +/- 0.01 g/cm2; P less than 0.01) and femoral neck (0.96 +/- 0.02 vs 0.90 +/- 0.02 g/cm2; P less than 0.02). The mean body weight was higher in the obese than in the nonobese white women (92 +/- 2 vs. 61 +/- 1 kg; P less than 0.001) and black women (94 +/- 3 vs. 63 +/- 1 kg; P less than 0.001). The mean BMD was higher in the obese than in the nonobese white women at the lumbar spine (1.24 +/- 0.03 g/cm2; P less than 0.05), trochanter (0.89 +/- 0.04; P less than 0.001), and femoral neck (0.99 +/- 0.03; P less than 0.01) and was higher in the obese than in the nonobese black women at the lumbar spine (1.33 +/- 0.03 g/cm2; P less tham 0.01), trochanter (0.88 +/- 0.04 g/cm2; P less than 0.05), and femoral neck (1.04 +/- 0.03 g/cm2; P less than 0.05). Multivariate regression analysis revealed positive correlations between body weight and BMD at each of the 3 weight-bearing sites, but not at the mid radius, in both the black women and white women.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1988

Hemodynamics of vein graft stenosis.

The hemodynamics of 56 femorodistal saphenous vein bypasses (in situ [n = 53] or reversed [n = 3]) identified to have residual or recurrent graft stenoses were characterized with Doppler-derived blood flow velocity and resting limb systolic pressure measurements. The magnitude and configuration of the graft blood flow velocity waveform were the best predictors of graft stenosis. Transformation of the graft blood flow velocity waveform from a triphasic to a monophasic or biphasic configuration coupled with a low (less than 45 cm/sec) or decrease (greater than 30 cm/sec) in peak systolic blood flow velocity relative to initial postoperative levels reliably predicted the presence of a remote occlusive lesion. In 20 (36%) of the 56 limbs, the ankle-brachial systolic pressure index (ABI) did not identify graft stenosis. The low sensitivity of ABI in the identification of graft stenosis was due to insignificant decrease (less than 0.15) of ABI (n = 11), incompressibility of the tibial arteries (n = 6), or residual occlusive lesions after surgery (n = 3). Duplex scanning of grafts with low blood flow velocity localized the site of stenosis in 31 (86%) of 36 patients examined. Graft revision increased systolic blood flow velocity from 33 +/- 9 to 77 +/- 18 cm/sec (mean +/- one standard deviation) a velocity similar to immediate postoperative levels (74 +/- 17 cm/sec). Resting ABI increased from 0.61 +/- 0.2 to 0.92 +/- 0.1 after graft revision. Four grafts with low systolic blood flow velocity (range 18 to 40 cm/sec) not revised occluded 5 to 45 days later.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Effect of intermittent pneumatic compression on lower limb oxygenation.

The effect of intermittent pneumatic compression (IPC) of the lower limbs on transcutaneous oxygen tension (tcPO2) was studied in 14 healthy volunteers and the same number of elderly patients. The oxygen sensor was calibrated at 37C in room air. This temperature was also used for measurements. Compression pressure in the IPC garment was standardized to 50mmHg inflation and zero mmHg deflation. Cycle time was set to 30 seconds inflation and 30 seconds deflation. It was found that using this combination of pressure and cycle times, tcPO2 fell during compression in all subjects and returned to the precompression level after the treatment. Although reactive hyperemia of various intensities occurred in some subjects after compression, tcPO2 did not rise significantly above the resting level. This suggests that the symptomatic improvement reported by patients treated with IPC was more likely to be due to enhanced removal of metabolites and supply of nutrients than to an improvement in leg oxygenation.

Adult↗