Targets and mechanisms.
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Biomedical subjects
Publications and source records attributed to J Owens.
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BACKGROUND/AIMS: Cationic antiseptics such as chlorhexidine (CHX) and cetyl pyridinium chloride (CPC) interact with dietary chromogens to produce extrinsic stain, and this can be used as a measure of activity of products. The aim of these studies in vitro was to determine if toothpaste influenced the tea staining effects of CHX and CPC as a predictor of action in vivo. METHOD: Clear acrylic specimens were soaked in pooled human saliva followed by sequential 2-min soaks in pairs of agents, namely 0.05% CHX, 0.05% CPC, 0.2% CHX, water (W) and toothpaste slurry (TP). The combinations were; TP/CHX, CHX/TP, TP/CPC, CPC/TP, W/CHX, CHX/W, W/CPC, CPC/W, TP/W, W/TP, W/W. These treatments were followed by a 60 min soak in tea. Optical density readings were taken at baseline and after each of 8 cycles. RESULTS: In the separate CHX and CPC studies by comparison with W/CHX, TP/0.05% CHX had little effect on staining, but TP/0.2% CHX showed a reduction in staining of 18%. 0.05% CHX/TP reduced staining by >40%, and 0.2% CHX by >78%. TP/CPC reduced staining by >26% and CPC/TP by 80%. Water after 0.2% CHX, 0.05% CHX and CPC reduced staining by 18%, 13% and 17% respectively. Little staining was seen with TP and W combinations. The data for CHX are in agreement with a study in vivo except TP followed by CHX reduced the activity of CHX. CONCLUSION: Toothpaste appears to adversely affect the activity of CHX and CPC particularly if used immediately after the antiseptics. The data further supports the concept of separating the use of antiseptics until sometime after the use of toothpaste, and the idea of developing mouthwash friendly toothpastes.
AIMS OF STUDY: The aims of the study were to carry out a critical incident study to: (1) Describe what nurses consider to be spiritual needs; (2) Explore how nurses respond to the spiritual needs of their patients; (3) Typify nurses' involvement in spiritual dimensions of care; (4) Describe the effect of nurses' intervention related to spiritual care. BACKGROUND: In the caring professions a focus on individuals as bio-psychological-spiritual beings is gaining recognition and this notion is based on the premise that there should be a balance of mind, body and spirit for the maintenance of health in a person (Stoll 1979). Emerging research highlights the importance of spiritual care in nursing and suggests that there is scope for improving this dimension of care in order to improve the quality of life for many patients. However, there is very little evidence about how nurses respond to the spiritual needs of their patients. Therefore the purpose of this study was to map by critical incident techniques how nurses construct and respond to patients' spiritual needs in a variety of clinical settings. METHODS: Critical incidents were obtained from 115 nurses. The data from these incidents were subjected to content analysis and categories were developed and described. The emerging categories were subjected to peer reviews to ensure reliability and validity of findings. FINDINGS: The findings suggest that there is confusion over the notion of spirituality and the nurse's role related to spiritual care. A variety of approaches to spiritual care emerged in this study from the critical incidents derived from nurse respondents. These were categorized as 'personal', 'procedural', 'culturalisit' or 'evangelical'. There was an overwhelming consensus that patients' faith and trust in nurses produces a positive effect on patients and families, and nurses themselves derived satisfaction from the experience of giving spiritual care. In this respect, spiritual care interventions promote a sense of well-being in nurses as well as being a valuable part of total patient care. CONCLUSION: The study concluded that there is scope for developing an ideal model of spiritual care using the critical incident data from this study.
AIMS: Coagulase-negative staphylococci (CNS) are now important nosocomial pathogens and are usually resistant to multiple antibiotics. Citrate is an alternative antimicrobial product which has been used as a preservative. METHODS AND RESULTS: In this pilot study the bactericidal activity of Na citrate against 10 isolates of CNS and 6 other gram-positive pathogens was examined and compared with that of Na lactate. CONCLUSIONS: All staphylococci tested were susceptible (> or = 2 log(10) killing) to citrate at 6.25-25 mg ml(-1). Na lactate showed only modest killing at 50 or 100 mg ml(-1). SIGNIFICANCE AND IMPACT OF THE STUDY: Citrate may warrant broader evaluation as an antimicrobial additive such as in topical agents.
This paper outlines some important issues discovered about undertaking qualitative interviews. A description of a study that involved interviewing the authors' students is followed by discussion of aspects of the interviewing process that became apparent during analysis of those interviews. Problems that were encountered with retrospective interviews, power differentials, question sequencing, some interview techniques, and a prior knowledge of the students are illuminated to assist other qualitative interviewers to be aware of these potential areas of difficulty.
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Objectives: The goal of the current study was to compare the sleep characteristics of children diagnosed with a partial arousal parasomnia to a community sample and further, to compare children diagnosed with sleep terrors to those diagnosed with sleepwalking.Background: Many children experience frightened awakenings, with up to 15% meeting criteria for a parasomnia. Despite this, very little empirical data exists examining parasomnias in childhood.Method: The parents of children (between 2 and 12 years of age) referred to a pediatric sleep disorders clinic completed the Children's Sleep Habits Questionnaire (CSH) on their child. The group meeting criteria for partial parasomnia was then matched with a community sample to identify differences in sleep characteristics between children with parasomnias and a normative sample.Results: Children with parasomnias had higher rates of bedtime resistance, sleep onset delay, night waking, and reduced sleep duration than a matched community sample. Sleepwalkers had more sleep onset problems than children with sleep terrors. Almost one quarter of sleepwalkers between 3 and 12 years of age reported nocturnal enuresis.Conclusions: Children with partial arousal parasomnias do have slightly more disturbed sleep than community controls.
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N-(1-Naphthyl)-N'-(3-[(125)I]-iodophenyl)-N'-methylguanidine ([(125)I]-CNS 1261) was synthesized as a potential radioligand to image N-methyl-D-aspartate (NMDA) receptor activation. [(125)I]-CNS 1261 was prepared by radioiodination of N-(1-naphthyl)-N'-(3-tributylstannylphenyl)-N'-methylguanidine using Na(125)I and peracetic acid. [(125)I]-CNS 1261 uptake in vivo reflected NMDA receptor distribution in normal rat brain, whereas in ischemic rat brain, uptake was markedly increased in areas of NMDA receptor activation. Radiolabeled CNS 1261 appears to be a good candidate for further development as a single photon emission computed tomography tracer in the investigation of NMDA receptor activation in cerebral ischemia.
The Auger electron emitting agent 5-[125I]iodo-2'-deoxyuridine (i.e. [125I]IUdR) holds promise for the treatment of residual glioma after surgery because this thymidine analogue kills only proliferating cells. However, malignant cells which are not synthesizing DNA during exposure to the radiopharmaceutical will be spared. To determine whether tumour incorporation of [125I]IUdR could be enhanced by protracted administration, we used a C6 cell line, growing in the brains of Wistar rats, as a glioma model and compared three methods of intracerebral delivery of [125I]IUdR. Twenty-four hours after administration of drug, autoradiography of brain sections demonstrated nuclear uptake of the radiopharmaceutical in cells throughout tumour while normal brain cells remained free of radioactivity. The [125I]IUdR labelling indices (% +/- s.e.m.) achieved were 6.2 (0.4) by single injection, 22.5 (4.1) using a sustained release polymer implant (poly(lactide-co-glycolide)) and 34.3 (2.0) by mini-osmotic pump. These results emphasize the need for a sustained delivery system as a prerequisite for effective treatment. These findings are also encouraging for the development of a sustained release system for radiolabelled IUdR for use in the treatment of intracranial tumours, particularly in the immediate postoperative setting.
The radiochemical purity (RCP) of 99Tcm-MAG3 was determined using solid-phase extraction (SPE), high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). The difference between the HPLC and SPE methods was highly significant (P < 0.001), yielding values for RCP of 94.4 +/- 1.4% and 86.0 +/- 5.1% [corrected] respectively (mean +/- s). Further qualitative analysis of the SPE fractions obtained, was carried out using HPLC and TLC. The unexpected presence of 99Tcm-MAG3 in one of the fractions was observed together with the appearance of hydrophilic impurities in the hydrophobic extract. This lack of specificity may be the reason for the discrepancy between the SPE and HPLC methods. Use of the SPE method leads to an underestimation of the RCP of 99Tcm-MAG3 and, indeed, had we been relied solely on this method of analysis, we would have had to reject most kits we prepared. In a separate study, we compared a TLC method with HPLC. Differences were found to be highly significant (P < 0.001), yielding values of 98.3 +/- 0.6% and 95.8 +/- 0.9% respectively. Comparison of the data points showed that TLC gave consistently higher RCP yield than HPLC. This elevated value was found to be due to the inability of the TLC method to separate 99Tcm-lipophilic impurity, seen on HPLC, from the 99Tcm-MAG3. Therefore, use of this TLC method leads to an overestimation of the RCP of 99Tcm-MAG3.
Radioiodinated meta-iodobenzylguanidine (MIBG) is used routinely for imaging and targeted radiotherapy of tumours derived from the neural crest. Since active uptake of MIBG by the noradrenaline transporter (NAT) makes a greater contribution to total drug accumulation than passive uptake when MIBG is present at low concentrations, tumour-specific uptake should be enhanced by the administration of lower molar amounts of MIBG. This could be achieved through the use of MIBG with a high specific activity. Commercially available preparations of 123I-MIBG have specific activities of approximately 200 MBq.mg-1. We have synthesized and used no-carrier-added (n.c.a.) 123I-MIBG produced by an iododesilylation reaction (specific activity 0.7 TBq.mg-1). We report here the first clinical studies comparing the commercially available and n.c.a. MIBG diagnostic preparations. Five patients with known phaeochromocytoma were studied. Unlike studies in animal models, no consistent improvement in tumour uptake was observed with the n.c.a. material. A larger patient group is required to determine whether there are significant differences between the two preparations, before proceeding to studies at therapeutic activity levels of n.c.a. 131I-MIBG. Even with no improvement in tumour uptake, n.c.a. MIBG may be the favoured formulation for therapeutic applications to reduce the molar amount of drug injected.
The manometric, ultrastructural, radiographic, and physiological consequences of retrograde biliary infusion were determined in normostatic and cholestatic mice. Intraluminal biliary pressure changed as a function of infusion volume, rate, and viscosity. Higher rates of constant infusion resulted in higher peak intraluminal biliary pressures. The pattern of pressure changes observed was consistent with biliary ductular and/or canalicular filling followed by leakage at a threshold pressure. Retrograde infusion with significant elevations in pressure led to paracellular leakage of lanthanum chloride, radiopaque dye, and [(14)C]sucrose with rapid systemic redistribution via sinusoidal and subsequent hepatic venous drainage. Chronic extrahepatic bile duct obstruction resulted in significantly smaller peak intrabiliary pressures and lower levels of paracellular leakage. These findings indicate that under both normostatic and cholestatic conditions elevated intrabiliary volumes/pressures result in an acute pressure-dependent physical opening of tight junctions, permitting the movement of infusate from the intrabiliary space into the subepithelial tissue compartment. Control of intraluminal pressure may potentially permit the selective delivery of macromolecules >18-20 A in diameter to specific histological compartments.
In previous in vitro studies, we proposed a role for the extracellular matrix component, laminin-2, and its integrin receptor, VLA-6, in thymocyte development. The characterization of two dystrophic mouse strains with different defects in laminin-2 allowed us to examine this proposal in vivo. Mice deficient in laminin-2, dy/dy, show a significant reduction in thymus size and number of thymocytes compared to normal littermates. These mice also exhibited apparent alterations of thymic architecture. Examination of the CD4/CD8 populations in dy/dy thymi showed large relative increases in the DN (CD4- CD8-) and SP (CD4+ CD8-, CD4- CD8+) populations and a significant decrease in the DP (CD4+ CD8+) population. Further examination of the DN population for CD44 and CD25 expression showed a remarkable decrease in the more mature pre-T cell populations. Analysis of apoptosis in situ, and by flow cytometry, in dy/dy thymi revealed a significant increase in apoptotic DN thymocytes in the capsule and subcapsular regions. Interestingly, thymocyte development appeared to proceed normally in dystrophic mice expressing a mutant form of laminin-2, dy2J, as well as, in fetal and neonatal dy/dy mice. We propose that laminin-2 plays an active role in thymocyte development by delivering cell survival and differentiation signals at specific stages of development in young adult mice.
These studies sought to develop and validate an occlusal site-specific plaque index to be used to measure plaque removal by brushing or chewing gum. The index divides the occlusal surfaces into imaginary zones from which scores are apportioned on a 0-4 basis dependent on the perceived % plaque coverage of each zone. Examiner calibration was conducted over 2 studies assessing inter-examiner reproducibility and intra-examiner repeatibility, respectively. Study 1 involved 2 examiners who recorded scores from the same 3 groups of subjects who had suspended tooth cleaning for 4 days. Analyses for inter-examiner reproducibility showed no significant mean differences between examiners or no significant differences between variances of the 2 examiners scores. Study 2 involved the same 2 examiners individually scoring 3 groups of subjects 2 x (approximately 60 min apart) for occlusal plaque. Analysis for intra-examiner repeatability showed no significant mean differences between the 2 scorings of each examiner. Furthermore, there were no significant differences between the variances of each examiner's scores except for 1 examiner in the repeatability exercise for the 1st group of subjects. Study 3 involved groups of subjects at 2 separate clinical sites (Bristol, England and Berne, Switzerland) being scored for occlusal plaque before and after toothbrushing with water or after no toothbrushing. Data from individual examiners and examiners combined revealed a significant reduction in occlusal plaque with brushing compared to no brushing. Study 4 was the same as study 3 but occlusal plaque was scored before and after chewing gum or not chewing gum. The Bristol examiner recorded a significant reduction in plaque by chewing gum compared to not chewing gum but the Berne examiner did not. The latter may have resulted from a considerable disparity in the number of evaluable occlusal surfaces between the two study sites. The index could be employed as part of the overall assessment or oral hygiene or used in clinical trials to study mechanical and chemical plaque control agents.
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This Australian study, a replication of Canadian research by Dibert & Goldenberg, was undertaken to explore the relationship between preceptors' perceptions of benefits, rewards and support, and their commitment to the preceptor role. A convenience sample of 134 nurse preceptors involved in an undergraduate nursing course were invited to complete a four-part questionnaire consisting of the Preceptor's Perception of Benefits and Rewards Scale, the Preceptor's Perception of Support Scale, the Commitment to the Preceptor Role Scale, and demographic details. The results, in the main, parallel those of the original research, with differences reflecting the distinct nature and the more recent use of preceptorship in Australia. The results indicate a clear commitment to the preceptor role and a perception that both material and non-material benefits are derived from acting in the role. Additionally, support from the institution and coworkers was considered vital for participation in the role. This not only has implications for nursing educators, administrators and potential preceptors, but also for those being preceptored.