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Biomedical subjects

J Moran

Publications and source records attributed to J Moran.

At least 109 records · Page 6Linked to original sources
PubMed1992

The effects of antimicrobial acrylic strips on the subgingival microflora in chronic periodontitis.

This study investigated the effects of root planing and/or the placement of acrylic strips containing chlorhexidine, metronidazole or tetracycline on the composition and antimicrobial susceptibility of the subgingival flora in chronic periodontitis. 101 periodontal pockets from 73 patients were entered into 6 treatment groups which were, chlorhexidine, metronidazole or tetracycline strips, root planing, root planing followed by metronidazole strips and a control, no treatment group. Total anaerobic counts and anaerobe/aerobe ratios were estimated from samples taken before treatment and 1, 2, 4, 8 and 12 weeks after treatment. In addition, a more detailed analysis of the effects of the treatments on the subgingival flora was carried out on 12 pockets in 12 patients. Tetracycline strips, metronidazole strips and root planing and metronidazole strips were more effective than chlorhexidine strips in causing reductions in total anaerobic count and anaerobe/aerobe ratio. However, the changes in microbial parameters rebounded to approach baseline levels 4 weeks after treatment. Chlorhexidine caused no detectable changes in the composition of the subgingival microflora, while metronidazole had a variable effect. Tetracycline appeared to effect major shifts in the composition of the microflora of treated pockets but caused a marked selection of tetracycline-resistant organisms.

Acrylic Resins↗
PubMed1992

A comparison of natural product, triclosan and chlorhexidine mouthrinses on 4-day plaque regrowth.

There is a continuing search for ingredients to enhance the chemical plaque inhibitory action of oral hygiene products. Sanguinarine, other natural extracts and triclosan have already been used in products. The aim of this study was to evaluate a number of triclosan and natural product rinses for effects on plaque regrowth. In particular, the influence of other rinse components were assessed, notably sodium lauryl sulphate (SLS) and zinc. The study was a randomised, blind, 9-cell cross-over design to measure the effects of each rinse on 4-day plaque regrowth from a zero baseline. 15 volunteers rinsed 2x daily with each product and plaque was recorded by area and score. The 0.2% chlorhexidine rinse (positive control) was significantly more effective, and the saline rinse (negative control) significantly less effective, than other rinses. Sanguinarine alone was little different from saline and the addition of zinc made a modest improvement in activity. The 3 triclosan/SLS rinses were more effective than the sanguinarine rinses but similar to their minus triclosan control rinse. A natural product/SLS experimental rinse was second to chlorhexidine and, in many analyses, significantly better than all other rinses, but caused some oral erosions. The results indicate that the plaque inhibitory properties of basic ingredients such as SLS may be difficult to enhance or surpass. However, the possible range of recipes, particularly using natural ingredients, provides scope for research and development in the field of oral hygiene products.

Adult↗
PubMed1992

A comparison of delmopinol and chlorhexidine on plaque regrowth over a 4-day period and salivary bacterial counts.

Delmopinol has been considered as a potential agent for the chemical control of plaque. The aims of these studies were to measure the effects of a 0.2% delmopinol hydrochloride mouthrinse on (1) plaque reformation and (2) salivary bacterial counts. Comparisons were made with a 0.2% chlorhexidine rinse and a placebo rinse. A group of 12 male volunteers took part in the plaque study which was of a double blind, randomised, 3 cell, cross-over design. From a zero plaque baseline subjects rinsed, 2x a day, under supervision, for 1 min with 10-ml volumes of the allocated rinse. After 4 days, during which no other form of oral hygiene was performed, plaque was scored by area and index. Plaque results were significantly lower with chlorhexidine and delmopinol compared with control, and with chlorhexidine compared to delmopinol. Side-effects with delmopinol were transient tingling and numbness of the tongue in some subjects. A 2nd group of 12 male volunteers received single, 1-min rinses of the 3 formulations. Salivary bacterial counts were determined immediately before and up to 420 min after rinsing. Compared to the control rinse, chlorhexidine significantly reduced bacterial counts of 420 min. Delmopinol produced a small reduction in bacterial counts which was only significantly different from control at one time point. Delmopinol deserves further evaluation as a chemical plaque inhibitor, particularly when used as an adjunct to normal toothcleaning.

Adult↗
PubMed1992

Local research ethics committees. Report of the 2nd National Conference.

The major theme of this conference was the present variable performance of local research ethics committees (LRECs). Opening the meeting, Dame Margaret Turner-Warwick pointed to the tremendous advances that were taking place in medical practice and science and that this was therefore an opportune moment to 'see where we are, and share solutions as well as problems in the discussion and debate of this meeting'.

Epidemiology↗
PubMed1992

Nursing research priorities for the care of the naval hospital patient: a Delphi survey.

The purpose of this study was to identify priorities for nursing research in a naval hospital using the Delphi technique. A general objective was to provide empirically based information to guide the development of a nursing research program at a regional medical treatment facility. Via a three-round Delphi survey, priority research questions were identified for the nursing department of a naval regional medical treatment facility. A serendipitous result was the identification of nursing research priorities within a deployed naval fleet hospital.

Delphi Technique↗
PubMed1991

Guided tissue regeneration.

One of the main goals of periodontal therapy is the predictable regeneration of the periodontium by allowing repopulation of periodontal ligament cells into the wound area after surgery and preventing the colonisation of the exposed root surface with epithelial, gingival, and bone cells. In order to achieve this, emphasis has been placed on the use of barrier materials in the form of semipermeable membranes which are interposed between the mucoperiosteal flap and the bone and tooth surfaces during surgery. This technique is known as 'guided tissue regeneration' (GTR) and this article looks at the theory and practice of GTR, as well as reviewing the use of non-resorbable membrane materials such as expanded polytetrafluor-ethylene and ethyl cellulose, and resorbable materials such as collagen and polylactic acid.

Biodegradation, Environmental↗
PubMed1991

Magnetic fields associated with spreading depression in anaesthetised rabbits.

Magnetic fields were measured with SQUID magnetometry outside the skull of anaesthetised rabbits during initiation and propagation of spreading depression (SD) in the cortex. Slowly changing fields (up to 1.4 pT) were observed during the propagation phase, from 4-8.5 min after initiation of SD with KCl application, with maxima at about 6 min. The peak amplitude of the equivalent net dipole generators in the brain was ca. 28 microA.mm, substantially less than previously observed with SD in vitro, but large enough that similar signals might be detectable in man.

Anesthesia, General↗
PubMed1991

Auditory evoked cortical magnetic field (M100-M200) measurements in tinnitus and normal groups.

Recently, Hoke et al. (1989) and Pantev et al. (1989) demonstrated that the auditory evoked cortical magnetic field (AECMF) M100 component was larger, and M200 was smaller and occurred later in subjects with unilateral tinnitus compared with normal subjects. These group amplitude differences resulted in an M200/M100 amplitude ratio that was smaller for the subjects with tinnitus. The purposes of the present investigation were to: 1) extend the observations of Hoke et al. (1989), and, 2) determine whether contralateral AECMF differences existed following stimulation of the non-tinnitus and tinnitus ears of patients with tinnitus. Neuromagnetic AECMF recordings were recorded from 25 young normal hearing and 14 patients with unilateral tinnitus and hearing loss. The results failed to support the findings of Hoke et al. (1989). Specifically, there is no evidence suggesting that the M100 amplitude is larger, the M200 latency later, or, the M200/M100 amplitude ratios smaller, when the two samples are compared. Additionally, there were no differences in the amplitudes or latencies of M100 or M200 when results from stimulation of the tinnitus and non-tinnitus ears of tinnitus subjects were compared.

Adult↗
PubMed1991

The use of an oxidising mouthwash to reduce staining associated with chlorhexidine. Studies in vitro and in vivo.

Discolouration of the teeth, tongue and dental restorative materials associated with the use of cationic antiseptics is still the limiting factor in long-term usage of antiplaque agents such as chlorhexidine. Oxidising agents have been used successfully to remove dental stain in animals, but products and regimens have not been evaluated in humans. These pilot studies in vitro and in vivo assessed a long-established oxidising mouthwash, based on peroxyborate, for stain removal from teeth and acrylic. The laboratory studies measured chlorhexidine tea stain removal from tooth and acrylic specimens. The oxidising agent markedly reduced staining on specimens. In a short-term clinical experiment, dental staining was forced over a 2 1/2-day period by reciprocal chlorhexidine and tea rinsing. 5 rinses with the oxidising mouthwash during the next 1 1/2 days dramatically reduced staining compared with water after rinses. Additionally, a single rinse with peroxyborate following the 5 water after rinses, again considerably reduced the residual staining. Effects on tongue staining were less impressive. Both experimental models produced findings consistent with those from the animal model. The results suggest proprietary oxidising mouthwashes could have a place in the control of dental stain associated with the use of chlorhexidine. Further studies to evaluate such products in a more conventional chlorhexidine regimen are indicated.

Adult↗
PubMed1991

Kinetic modeling as a prescription aid in peritoneal dialysis.

Methods for calculating fluid and mass removal in peritoneal dialysis are presented in order to aid clinicians in their care and management of patients and to assist them in their understanding of the physiological mechanisms which govern peritoneal transport. These methods are based on the Pyle-Popovich peritoneal mass transport model which encompasses both diffuse and convective transport as well as lymphatic flow and residual renal function. Algebraic solutions to the mass balance equations governing solute transport are provided. Since these solutions are expressed explicitly as functions of time, they are easily programmed for use on a personal computer or calculator. This offers considerable advantage over the more computer-intensive numerical solutions which had been previously required since one can now calculate both mass removal and changes in blood concentration at the end of an exchange without requiring any intermediate calculations. This computational advantage and the ability to model changes in blood concentration are shown to be of particular importance when modeling more dynamic therapies such as CCPD or Tidal peritoneal dialysis. Finally, the model and solutions, when assessed clinically among 5 patients on two separate occasions, resulted in predicted fluid and mass removals which were in high concordance with measured fluid and mass removals (concordance correlation coefficients in excess of 0.97). Our findings suggest that kinetic modeling can provide the kind of analytical tools necessary to guide clinicians in their care and management of peritoneal dialysis patients.

Algorithms↗
PubMed1991

The effects of a cetylpyridinium chloride prebrushing rinse as an adjunct to oral hygiene and gingival health.

A NUMBER OF MOUTHWASH PRODUCTS containing cetylpyridinium chloride (CPC) are available. Data for individual products are limited, although overall the antiseptic has been shown to reduce plaque. Results for gingivitis reductions by CPC have been equivocal. This study was an active/placebo parallel group design to evaluate the use of a CPC mouthrinse as an adjunct to oral hygiene when used before toothbrushing. Plaque and gingivitis scores were recorded at baseline and after 6 weeks, following twice daily use of the active or placebo prebrushing rinses. Plaque and gingivitis were significantly reduced at 6 weeks in both groups with no significant treatment differences between the active and placebo formulations. Whether the order of rinsing to toothbrushing influenced these findings cannot be determined. However, the results further question the adjunctive benefits of CPC rinses to gingival health.

Cetylpyridinium↗
PubMed1990

Volume-sensitive release of taurine from cultured astrocytes: properties and mechanism.

Release of taurine in response to cell swelling induced by hyposmolarity was observed in cultured astrocytes. Efflux of 3H-taurine increased by 30% and 70% upon reductions in osmolarity of only 5% and 10%. Reductions in osmolarity of 20%, 30%, and 50% stimulated basal taurine release by 300%, 500%, and 1,500%, respectively. The properties of this volume-sensitive release of taurine were examined to investigate: 1) its association with K+ and Cl- fluxes, currently activated during volume regulation: 2) its relationship with Ca2(+)-dependent reactions; and 3) the mechanism of the taurine efflux process. Taurine release was unaffected by removal of Na+, Ca2+, or Cl-, by pimozide and trifluoperazine, or by agents disrupting the cytoskeleton. The K+ channel inhibitors barium, quinidine, tetraethylammonium, and gadolinium had no effect. Taurine release was reduced by furosemide, a blocker of K+/Cl- cotransport, but not by the more specific inhibitor, bumetanide. It was markedly reduced by the inhibitors of Cl- channels DIDS, SITS, and anthracene-9-carboxylate. Taurine efflux was pH-dependent, being reduced at low pH values. It was decreased at 4 degrees C but not at 14 degrees C or 20 degrees C. These results suggest that the volume-sensitive release of taurine is independent of K+ fluxes but may be associated with Cl- conductances. It also seems unrelated to Ca2(+)-dependent transduction mechanisms. The Na(+)-dependent taurine carrier apparently is not involved in the swelling-induced release process.

Animals↗
PubMed1990

The use of antimicrobial acrylic strips in the nonsurgical management of chronic periodontitis.

Evidence to date has demonstrated the potential value of acrylic strips to deliver antimicrobial compounds into periodontal pockets. The present study was designed to evaluate further the therapeutic effect of antimicrobial acrylic strips in the management of chronic periodontitis. A total of 101 pockets in 69 patients were randomly treated with (1) chlorhexidine strips, (2) metronidazole strips, (3) tetracycline strips, (4) root planing, and (5) combined root planing and metronidazole strips. Immediately before and after treatment clinical measurements of disease were recorded over a three-month period. For all treatment groups significant improvements in clinical parameters were seen compared to control untreated sites but the most effective treatment was combined root planing and metronidazole and the least effective chlorhexidine. Although not significant, combined root planing and metronidazole also appeared to produce some adjunctive effects on clinical parameters compared to root planing alone. Antimicrobial acrylic strips appear useful treatments for chronic periodontitis, but should be used primarily as an adjunct to conventional root planing.

Acrylic Resins↗
PubMed1990

Neuromagnetic fields in migraine: preliminary findings.

Neuromagnetic signals consistent with spreading cortical depression have been observed in 9 of 12 migraine patients studied, but not in normal controls (out of 8 studied) or in patients with non-migrainous headache (4 studied). These signals consist of large amplitude, usually biphasic waveforms presumably arising from the onset or offset of spreading cortical depression in a sulcus, and prolonged attenuation of magnetic amplitudes, associated with suppressed neuronal activity. Techniques are described which recognize various kinds of artefacts and which distinguish changes in state of arousal of the patient from the presumed spreading cortical depression signals.

Cortical Spreading Depression↗
PubMed1990

Antibody to collagen type I in gingival crevicular fluid.

Gingival crevice fluid (GCF) was collected from inflamed sites in 20 patients before and 6 weeks after treatment. Levels of IgG to human collagen Type I were measured in the GCF and autologous serum using an enzyme-linked immunosorbent assay and compared with levels in control sera. IgG antibody to collagen was detected in GCF at significantly (P less than 0.01) higher levels than in control sera, but these levels were not significantly (P greater than 0.05) different from those in autologous sera. The levels of IgG antibody in GCF and autologous sera did not alter significantly (P greater than 0.05) after treatment. IgG antibody to collagen Type I is present in GCF in the diseased and healing state.

Adult↗
PubMed1989

Stimulation of the N-methyl-D-aspartate receptor promotes the biochemical differentiation of cerebellar granule neurons and not astrocytes.

Cerebellar granule cells are believed to be glutamatergic, but, as they receive excitatory amino acidergic input from mossy fibers, they also possess N-methyl-D-aspartate (NMDA) receptors. The possible involvement of these NMDA receptors in the biochemical differentiation of cultured granule neurons was studied in terms of the specific activity of phosphate-activated glutaminase, an enzyme important in the synthesis of the putative neurotransmitter pool of glutamate. When the partially depolarized cells were treated with NMDA for the last 3 days (i.e. between 2 and 5 days in vitro), it elevated specific activity of glutaminase in the dose- and time-dependent manners. The half-maximal effect was obtained at about 10 microM NMDA, whereas the maximum concentration, which produced about a 2.7-fold increase in 5-day-old cultures, was about 50 microM NMDA. This increase in glutaminase was completely blocked by the NMDA receptor antagonist, 2-amino-5-phosphonovaleric acid, and by the NMDA receptor-linked Ca2+ ion channel blockers, MK 801 and Mg2+. The effect of NMDA was not related to the survival of the granule cells, as the experiments were carried out before the dependence on high K+ for the survival of granule cells develops in culture, and during the period of investigation none of the compounds used compromised the survival of these cells. The enhancement of glutaminase activity was due to an induction in enzyme protein, since it was completely blocked by cycloheximide and actinomycin D. In contrast to granule neurons, the treatment with NMDA had no significant effect on the activity of glutaminase and glutamine synthetase in cultured cerebellar astroglial cells. Our present results on glutaminase enzyme would indicate that an increase in the cellular concentration of free Ca2+ mediated through the NMDA induced increase in Ca2+ conductance, leads to long term changes in differentiating cerebellar granule neurons, and it is possible that this kind of physiological stimulation of granule cells is normally provided in vivo by the presynaptic glutamatergic mossy fibers.

2-Amino-5-phosphonovalerate↗