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Biomedical subjects

J Moran

Publications and source records attributed to J Moran.

At least 127 records · Page 7Linked to original sources
PubMed1989

A comparison of oral milrinone, digoxin, and their combination in the treatment of patients with chronic heart failure.

We randomly assigned 230 patients in sinus rhythm with moderately severe heart failure to treatment with digoxin, milrinone, both, or placebo. The effects of each were compared during a 12-week, double-blind trial. Treatment with milrinone or digoxin significantly increased treadmill exercise time as compared with placebo (by 82 and 64 seconds respectively; 95 percent confidence limits, 44 and 123, and 30 and 100). Both treatments reduced the frequency of decompensation from heart failure, from 47 percent with placebo to 34 percent with milrinone (P less than 0.05; 95 percent confidence limits, 22 and 46) and 15 percent with digoxin (P less than 0.01; 95 percent confidence limits, 7 and 26). However, the clinical condition of 20 percent of the patients taking milrinone deteriorated within two weeks after treatment was begun, as compared with only 3 percent of those taking digoxin (P less than 0.05). The left ventricular ejection fraction at rest was not significantly changed by milrinone (+0.2 percent; 95 percent confidence limits, -1.5 and 1.9), but it was increased by digoxin (+1.7 percent; P less than 0.01; 95 percent confidence limits, -0.03 and 3.4) and decreased by placebo (-2.0 percent; 95 percent confidence limits, -3.8 and -0.1). Three-month survival was related inversely to the base-line ejection fraction. Analysis of mortality from all causes according to the intention to treat suggested an adverse effect of milrinone (P = 0.064). After adjustment for an excess of patients with lower ejection fractions randomly assigned to receive milrinone, this trend was not significant (P = 0.26). Increased ventricular arrhythmias occurred more frequently in patients who received milrinone than in those who did not (18 vs. 4 percent; P less than 0.03). We conclude that milrinone significantly increased exercise tolerance and reduced the frequency of worsened heart failure. However, in the population of patients studied, milrinone or the combination of milrinone and digoxin offered no advantage over digoxin alone. Furthermore, our data suggest that milrinone may aggravate ventricular arrhythmias.

Administration, Oral↗
PubMed1989

Effect of potassium depolarization on phosphate-activated glutaminase activity in primary cultures of cerebellar granule neurons and astroglial cells during development.

The cerebellar granule cells are believed to be glutamatergic neurons. During the normal development of granule cells grown in a chemically defined medium, the specific activity of phosphate-activated glutaminase increased from 60 at 3 days to 150 (nmol/h/mg protein) at 15 days in vitro. Treatment with 25 mM K+ for the last 2 days elevated glutaminase activity in an age-dependent manner: about 100% at 3 and 6 days, 75% at 10 days, and 40% at 15 days in vitro. The enhancement of glutaminase in granule cells was dose-dependent. The half-maximal effect was obtained at about 20 mM K+, whereas the maximum concentration, which produced about a 2.5-fold increase in 3-day-old cultures was about 40 mM K+. The voltage-sensitive Na+ channel inhibitor tetrodotoxin had no effect on the depolarization-induced activity in granule cells. However, the increase in glutaminase by 25 mM K+ was significantly blocked by both organic (nifedipine) and inorganic (Ni2+ and Mg2+) calcium antagonists, indicating that elevation in activity may be mediated through transmembrane Ca2+ entry into granule cells. In contrast to neurons, in cultured cerebellar astrocytes, the activity of glutaminase slightly decreased during development, and treatment with 25 mM K+ had no significant effect on this enzyme activity. The present findings, together with previous observations, would indicate that depolarization with K+, which is believed to mimic in vivo presynaptic stimulation, could be one of the mechanisms that selectively controls the development and function of neurons, when measured in terms of the activity of the enzymes involved in the synthesis of cell-specific neurotransmitters.

Animals↗
PubMed1989

Effect of histamine on the development of astroglial cells in culture.

The effect of histamine on different aspects of the growth of astrocytes was studied using primary cultures derived either from forebrain or from cerebellum of the rat. The influence on general growth and differentiation was monitored in terms of the activities of ornithine decarboxylase and glutamine synthetase enzymes, whereas [3H]thymidine incorporation into DNA was used as a specific index of cell proliferation. Treatment with 500 nM histamine of cells grown for 6 days in vitro, caused a time-dependent significant increase in ornithine decarboxylase activity of astrocytes from both sources. The maximum increase was observed at 4 h after histamine treatment, at that time the elevation in ornithine decarboxylase activity being about 80% and 300% over control values in the forebrain and the cerebellar astrocytes, respectively. Under similar experimental conditions, addition of histamine (500 nM) to medium resulted in a significant increase in [3H]thymidine incorporation into DNA in both types of cultures: in comparison with control, the elevation was about 45% at 48 h in forebrain astrocytes and at 24 h in cerebellar astrocytes. On the other hand, the specific activity of glutamine synthetase in cerebellar astrocytes was markedly enhanced (about 100%) by treatment with histamine (500 nM) for 4 days, but forebrain astrocytes were little affected. Addition of histamine to the culture medium produced no significant alteration in the activity of lactate dehydrogenase and protein content of either type of astroglial cells. The present findings, which support our earlier proposal that the biochemical properties of astrocytes differ between various brain regions, provide direct evidence for the involvement of histamine in the regulation of growth and development of astrocytes.

Animals↗
PubMed1989

Lipids, lipoproteins and apolipoproteins A-I and B and apolipoprotein losses in continuous ambulatory peritoneal dialysis.

Comparison of lipid, lipoprotein and apolipoprotein levels was made between 3 groups: continuous ambulatory peritoneal dialysis patients (n = 5); haemodialysis patients (n = 15) and normals (n = 31). Continuous ambulatory peritoneal dialysis (CAPD) patients showed significantly elevated total cholesterol, low density lipoprotein (LDL)-cholesterol and apolipoprotein B (apo B) levels compared with haemodialysis and normal groups. Both CAPD and haemodialysis (HD) showed reduced levels of high density lipoprotein (HDL)-cholesterol and apolipoprotein A-I (apo A-I). Measurement of apo A-I and apo B in dialysate during a 6 h CAPD session indicated significant losses of apo A-I to dialysate with negligible losses of apo B. Grossly elevated apo B and reduced apo A-I indicates that CAPD patients are at increased risk of coronary heart disease and that their risk is probably greater than for haemodialysis patients.

Apolipoproteins A↗
PubMed1989

The effect of a cetylpyridinium chloride (CPC) detergent foam compared to a conventional toothpaste on plaque and gingivitis. A single blind crossover study.

A CPC-detergent formulation in a foam vehicle, was compared with a fluoride toothpaste for its ability to prevent plaque and gingivitis over a period of 12 days. Whilst refraining from all other oral hygiene procedures, the foam or toothpaste was applied to the teeth in fluoride application trays, in a group of 14 volunteers. At days 8 and 12 of this crossover study, the following assessments were made: gingival crevicular fluid; gingival index; bleeding on probing; plaque index; plaque area. Except for plaque area at day 8 of the study, there were no significant differences between the 2 products at either day 8 or day 12. It is therefore concluded that the CPC-detergent formulation, in its present form, does not inhibit plaque and gingivitis more effectively than a conventional fluoride toothpaste.

Adolescent↗
PubMed1989

Comparison of the effect of toothpastes containing enzymes or antimicrobial compounds with a conventional fluoride toothpaste on the development of plaque and gingivitis.

Many toothpastes have been formulated over recent years to contain antimicrobial compounds with the aim of preventing or reducing plaque, calculus, gingival inflammation or dental caries. For many, if not all of these toothpastes, it has yet to be proven whether they are significantly better at reducing plaque and gingivitis than conventional toothpastes, for which no such therapeutic effects have been claimed. This 12-day, incomplete block designed, cross-over study compared the development of plaque and gingivitis following rinsing with toothpaste slurries containing the following active ingredients: (1) hexetidine/zinc citrate, (2) 0.2% triclosan, (3) amyloglucosidase/glucose oxidase, (4) sodium fluoride/sodium monofluorophosphate (NaF, MFP). By the 8th day of the study, a significant difference in gingival crevicular fluid (GCF) and GI was found between the groups. By day 12, however, no significant difference in plaque index and gingival inflammation was found between the 4 toothpastes, although plaque area was significantly reduced with the hexetidine/zinc citrate paste when compared to the conventional fluoride paste. It was concluded that the active ingredients added to the toothpastes evaluated in this study provided little or no more additional benefit to oral hygiene and gingival health than could be achieved with a conventional fluoride toothpaste.

Adult↗
PubMed1989

Chronic cavitary respiratory papillomatosis.

A 19-year-old white man with multiple recurrences of respiratory papillomatosis was admitted for recurrent left lower lobe pneumonia and lung abscesses. He was found to have a single large laryngeal papilloma, widespread bronchial papillomatosis, and large cavitary lesions of the left lower lobe. A lobectomy was performed. The smooth-walled, squamous-lined cavities contained large numbers of papillomas, which were strongly positive for human papillomavirus type 11 by in situ DNA hybridization. Findings of evaluation of the patient's humoral and cell-mediated immunity were within normal limits. Cavitation appears to have resulted from bronchial obstruction, postobstructive pneumonia, and liquefactive necrosis. We speculate that squamous metaplasia allowed the continued proliferation of papillomavirus within the cavities.

Adult↗
PubMed1988

Increased attention enhances both behavioral and neuronal performance.

Single cells were recorded from cortical area V4 of two rhesus monkeys (Macaca mulatta) trained on a visual discrimination task with two levels of difficulty. Behavioral evidence indicated that the monkeys' discriminative abilities improved when the task was made more difficult. Correspondingly, neuronal responses to stimuli became larger and more selective in the difficult task. A control experiment demonstrated that changes in general arousal could not account for the effects of task difficulty on neuronal responses. It is concluded that increasing the amount of attention directed toward a stimulus can enhance the responsiveness and selectivity of the neurons that process it.

Animals↗
PubMed1988

The antibacterial effect of toothpastes on the salivary flora.

Both past and presently available toothpastes contain potential antimicrobial agents which could have a beneficial effect in the prevention of plaque and gingivitis. If these preparations were to be effective clinically, some effect on salivary bacteria would also be expected. This cross-over study measured salivary bacterial counts and the presence or absence of residual antibacterial activity in saliva following tooth brushing with 7 commercially available toothpastes, and moreover, compared their effect with that produced by a chlorhexidine gel. Generally, all toothpaste products produced a reduction in aerobic, anaerobic and streptococcal counts with a hexetidine containing toothpaste producing the largest and longest lasting reduction. In contrast, an enzyme containing toothpaste and an amine fluoride toothpaste, had little effect on bacterial counts. The chlorhexidine gel produced the largest reduction in salivary counts, which was evident for at least 5 h following brushing. Residual antibacterial activity in saliva was only evident immediately following brushing with the hexetidine toothpaste, but for the chlorhexidine gel, was present up to 90 min following brushing. The findings of this study have illustrated the limited antibacterial activity of presently available toothpastes on the salivary flora compared to chlorhexidine, and as such, would tend to question the relative benefit of toothpaste in preventing periodontal disease through an antimicrobial effect.

Adult↗
PubMed1988

A clinical trial to assess the efficacy of sanguinarine-zinc mouthrinse (Veadent) compared with chlorhexidine mouthrinse (Corsodyl).

A single-blind crossover study was used to compare the ability of a 0.2% chlorhexidine mouthrinse (Corsodyl) with a sanguinarine-zinc mouthrinse (Veadent) to inhibit plaque and gingivitis. 14 volunteers starting with plaque-free mouths and optimal gingival health, rinsed with the preparations over two 19-day periods whilst refraining from all other oral hygiene procedures. At days 8, 15 and 19 of the trial, Corsodyl was significantly more effective at inhibiting both plaque and gingivitis. The findings of this study would suggest that the Veadent mouthrinse would at most only have a limited rôle as an inhibitor of plaque and gingivitis.

Adult↗
PubMed1988

Use of antimicrobial containing acrylic strips in the treatment of chronic periodontal disease. A three month follow-up study.

Local antimicrobial therapy has been considered for use in the treatment of chronic periodontal disease. This study evaluated chlorhexidine, metronidazole, and tetracycline delivered into periodontal pockets in an acrylic resin vehicle and compared the results with root planed and untreated sites over a three-month follow-up period. One site per patient where pocketing greater than or equal to 6 mm associated with a single rooted tooth was randomly allocated to one of the five possible regimens. Baseline and follow-up measurements included probing depth, loss of attachment, bleeding on probing, crevicular fluid flow, and dark-field microscopy of a subgingival plaque sample. Intratreatment evaluations revealed no significant changes in any parameter for untreated sites. Significant improvements in many parameters occurred with all four therapies although the magnitude and duration were greater in metronidazole and root planing groups. The more important intertreatment comparisons indicated that most treatments produced significant benefits compared with the control group; however, again these were greater with metronidazole and root planing. Furthermore, significantly greater effects were noted for metronidazole and root planing compared with tetracycline and more particularly chlorhexidine. It is concluded that some locally delivered antimicrobials alone may be useful in the treatment of chronic periodontal disease. However, at this time local antimicrobial therapy should be considered as adjunctive to conventional debridement techniques.

Adult↗
PubMed1987

Antithymocyte globulin therapy for pure white cell aplasia.

Severe neutropenia due to selective loss from the bone marrow of cells of the entire neutrophil maturation sequence developed in a patient with Goodpasture's Syndrome and was associated with serious infections complicating continuous ambulatory peritoneal dialysis. Involvement of T-lymphocytes in the process affecting the neutrophil series was implicated by the relation between recovery from neutropenia and treatment with antithymocyte globulin (ATG). Azathioprine and corticosteroid administration failed to sustain recovery from neutropenia induced by ATG. It is concluded that ATG can provide a nonmyelotoxic form of therapy for pure white cell aplasia whose effectiveness is independent of responsiveness to other immunosuppressive agents.

Adult↗
PubMed1987

Effect of tocopherol and taurine on membrane fluidity of retinal rod outer segments.

The deficiency of taurine and alpha-tocopherol results in disturbances of the structure of retinal rod outer segments. In this study the effect of alpha-tocopherol (vitamin E) and taurine on the fluidity of membranes from frog retinal rod outer segments and of liposomes prepared with lecithin or with lipids from outer segment membranes was examined by steady-state fluorescence polarization of diphenyl-hexatriene (DPH). alpha-Tocopherol increased the DPH anisotropy parameter in both preparations. The vitamin modified the breakpoint temperature of Arrhenius plots of DPH anisotropy, and decreased the activation energy. Taurine failed to modify any of the parameters examined in both outer segment membranes and lecithin liposomes. These results suggest a stabilizer role for tocopherol in rod outer segment membranes. In contrast, the requirement of taurine to maintain outer segment structure seems unrelated to an effect on the physical state of membrane lipids.

Animals↗
PubMed1987

Differentiation of proximal bronchogenic carcinoma from postobstructive lobar collapse by magnetic resonance imaging. Comparison with computed tomography.

MRI and CT studies in 18 patients with proximal bronchogenic carcinoma and postobstructive lobar collapse were analyzed retrospectively. The relative abilities of these imaging techniques to identify central tumor by a contour abnormality and to distinguish tumor mass from collapsed lung by CT attenuation values and MRI signal intensities were compared. MRI and CT were equivalent in their ability to identify a contour abnormality, both succeeding in 13 of 18 (72%) patients. CT was more successful than MRI in differentiating tumor mass from collapsed lung. Dynamic computed tomography scanning differentiated tumor from collapsed lung in eight of ten (80%) patients. MRI demonstrated different signal intensities of tumor and collapsed lung in 8 of 18 (44%) patients. T2-weighted images more often separated tumor from collapsed lung than other imaging sequences.

Aged↗
PubMed1987

Metastatic malignant melanoma presenting clinically as obstruction of the right ventricular inflow and outflow tracts. Characterization by magnetic resonance imaging.

Metastatic disease involving the heart may present in a variety of fashions. A patient with melanoma metastatic to the right ventricle which was diagnosed clinically by evidence of recent onset of right ventricular inflow and outflow tract obstruction is described. Important information regarding the extent of the metastatic process and potential resectability of the tumor was gained by magnetic resonance imaging.

Cardiomegaly↗