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Biomedical subjects

C Newton

Publications and source records attributed to C Newton.

At least 55 records · Page 3Linked to original sources
PubMed1995

A study of the accuracy of predicted soft tissue changes produced by a computer software package (COG 3.4) in a series of patients treated by the Le Fort I osteotomy.

This study was performed to compare soft tissue movements resulting from a series of Le Fort I osteotomies with those predicted for the same cases by means of a computerised software package (COG 3.4). The source material consisted of serial lateral cephalometric radiographs for 25 consecutive patients that had received similar Le Fort I osteotomies primarily to correct an antero-posterior skeletal discrepancy. Generally it was found that many of the digitised points on the facial profile were surprisingly well predicted. In addition, the chin and profile changes resulting from mandibular auto-rotation also were reasonably well predicted. However, in a number of cases prediction was less consistent and this was particularly true in the region of the nose and lips. In such instances, initial size, thickness and the existing morphology of the soft tissues appeared to be important factors. The tendency of the software occasionally to 'cross-over' the plots for the upper and lower lip profile made the judgement in this area of predicted profile change difficult in some cases.

Adolescent↗
PubMed1995

Joint CNS appointment: is it viable?

A CNS joint appointment that is supported by the departments of nursing and medicine is viable when goals of the nurse and the organizations are congruent and expectations are delineated. Many challenges and strategies are associated with a joint appointment. Although the challenges and strategies were similar for the first (C.N.) and second authors (L.A.), their experiences differed. Based on the experience of the authors, feasibility of a joint appointment and benefits, challenges, and strategies for enacting the role are presented.

Feasibility Studies↗
PubMed1995

delta 9-Tetrahydrocannabinol, cytokines, and immunity to Legionella pneumophila.

The major psychoactive component of marijuana, delta 9-tetrahydrocannabinol (THC), has been shown to suppress the functions of various immune cells. However, the relationship of these findings to THC-induced suppression of host resistance to infection has not been firmly established. In this report, we review the literature concerning THC's effects on cytokine production and resistance to infection with Legionella pneumophila (Lp). Recent reports have linked THC-induced immunomodulation with drug-induced modulation of the cytokine network. Specifically, THC in vivo suppresses interferon (IFN) production while in vitro modulates the production of tumor necrosis factor (TNF), interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-2 receptor (IL-2R). These results suggested that THC treatment might alter host immunity by disrupting the cytokine network. Immunity and resistance to infection with Lp depends upon the activation of killer cells and the stimulation of the cytokine network. THC injection into rodents was observed to augment acute phase cytokine mobilization in response to a primary Lp infection; on the other hand, the drug suppressed the development of protective immunity and resistance to secondary Lp infection by causing a change in the profile of T helper cell cytokines produced by Th1 and Th2 cells. Thus, it appears that THC injection suppresses resistance to Lp infection by disrupting the cytokine network. Regarding the molecular mechanisms of these effects of THC, data is reviewed concerning the role of cannabinoid receptors (CR) in cells of the immune system. In summary, the literature to date supports the role of THC as an immunomodulator capable of suppressing resistance to infection through mechanisms involving alteration of the cytokine network. The role of CR receptors in these events has yet to be determined.

Cytokines↗
PubMed1995

Legionella pneumophila-induced visual learning impairment reversed by anti-interleukin-1 beta.

Infecting mice with the opportunistic intracellular pathogen Legionella pneumophila markedly inhibited place learning of infected C57BL/6 mice as determined by the Morris water maze test. Mice infected with L. pneumophila evinced much less ability to learn the position of a hidden platform than did normal noninfected mice, which quickly learned the location of the hidden platform and escaped from the cool water of the pool with increasing efficiency. However, infected mice treated with anti-interleukin-1 (anti-IL-1) neutralizing antibody learned the task with about the same efficiency as the controls. When the animals were tested 1 week after learning, control animals remembered the task well and were able to escape with near maximal efficacy. On the other hand, L. pneumophila-infected mice performed as poorly after the 1 week rest as during the training period, indicating that infection blocked learning and not merely performance. Mice infected with L. pneumophila and given the antibody treatment were found to be indistinguishable from controls in that they remembered the task and escaped with good efficiency. Thus, the results of this study suggest that the pro-inflammatory cytokine, IL-1 beta, is involved, at least partly, in the attenuation of spatial navigational learning in mice infected acutely with a sublethal concentration of L. pneumophila. These results, therefore, suggest that cognitive impairment of L. pneumophila-infected mice may be related to the cytokine IL-1 beta and, furthermore, that cytokines may be related to learning and memory changes experienced by individuals suffering acute bacterial infections.

Animals↗
PubMed1995

A decision support database for nurse care planning as part of a hospital information system.

This paper, based on a doctoral thesis, describes the development and evaluation of a computerized care planning database at the Royal Hampshire County Hospital. It is part of an integrated Hospital Information System, the first to be installed in an United Kingdom. The research examines nurses' attitudes to the Nursing Process to the new care planning system before, three months after, and one year after its implementation. The quality of manual vs. computer care planning is compared in the same time periods using an existing quality assurance instrument and an audit tool, developed during the research. All data was analyzed in each time period in a framework of personal and organizational change theories. The proactive nature of the research allowed findings to be used as a basis for modifications during the process, which culminated in a further project to provide a database of standard based care plans. Results showed that an understanding of the Nursing Process was inadequate and that most nurses were ambivalent about paper care planning and the proposed computer care plans. Three months after implementation, attitudes became more unfavorable; however, after a year, attitudes showed a significant shift towards the positive pole. Conversely, the overall quality-of-care planning improved significantly.

Attitude to Computers↗
PubMed1994

delta 9-Tetrahydrocannabinol (THC) modulates IL-1 bioactivity in human monocyte/macrophage cell lines.

We have previously observed that delta 9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, increased supernatant interleukin-1 (IL-1) bioactivity in cultures of mouse resident peritoneal macrophages stimulated with lipopolysaccharide (LPS). In this study, experiments were performed to determine whether THC treatment similarly affected phagocytes of human origin. The results showed that THC increased the levels of supernatant IL-1 bioactivity of two human monocytic cell lines, but only if the cells were differentiated with phorbol myristate acetate. Undifferentiated cells displayed decreased IL-1 bioactivity in response to THC. However, under conditions in which THC augmented supernatant IL-1 bioactivity from THP-1 cells, ELISA studies showed that the levels of IL-1 alpha and IL-1 beta were unchanged and decreased, respectively. Furthermore, supernatant interleukin-6 (IL-6) levels were decreased, but tumor necrosis factor (TNF-alpha) levels were increased by THC treatment. These results show that THC treatment modulates cytokine production and/or release by mouse and human macrophages and the drug effects on IL-1-like bioactivity in the supernatants of the human THP-1 cells are due to increased levels of other cytokines, such as TNF-alpha, rather than IL-1 itself.

Animals↗
PubMed1994

Outcome after temporary vascular occlusion for the management of renal trauma.

To determine the impact of temporary vascular occlusion on patient outcome after surgery for renal trauma, we reviewed the records of 30 patients managed since 1977 whose injuries represented 17% of a total of 181 injuries in 175 patients. Reconstruction was judged to be adequate in 25 patients, while the remaining 5 underwent immediate nephrectomy. Compared with patients whose renal injuries did not require temporary occlusion, these 30 were more likely to have renovascular trauma, shock at presentation and higher transfusion requirements. Postoperatively, of 20 patients renal imaging (9) and radionuclide scanning (11) demonstrated preservation of significant renal parenchyma or function in 18 (90%). Although complications were more common in patients whose renal injuries required temporary vascular occlusion, only 2 were related to the renal injury or its method of repair (urinary extravasation in 1 patient and azotemia in 1 with bilateral injury). Temporary vascular occlusion can be performed expeditiously and safely, and may have an important role in preserving renal function. Our results support the routine use of early vascular control and the selective use of temporary vascular occlusion in renal injuries requiring exploration.

Adolescent↗
PubMed1994

Differences and similarities in permissive A/J versus non-permissive BALB/c murine macrophages infected with Legionella pneumophila: the role of iron.

Legionella pneumophila, a facultative intracellular pathogen, replicates within and kills thioglycolate-elicited (TG) macrophages from A/J mice, while growth is inhibited in TG macrophages from BALB/c mice which show no impaired viability. The role of iron in BALB/c and A/J macrophages regarding their permissiveness to L. pneumophila intracellular growth was investigated. We previously reported that TG macrophages from the A/J mouse strain readily supported the intracellular growth of L. pneumophila, while resident macrophages from the same strain of mice were not permissive. Recently we also found that such a difference in permissiveness between both A/J macrophage populations may be explained, at least in part, to intracellular availability of iron. In this report, differences in permissiveness to L. pneumophila growth between A/J TG macrophages and BALB/c TG macrophages was not due to intracellular iron availability. BALB/c and A/J TG macrophages exhibited similar expression of transferrin receptor and cellular iron content. The treatment of BALB/c TG macrophages with different iron compounds, namely ferric nitrilotriacetate (12.5-100 microM), ferric citrate (12.5-100 microM) and transferrin (0.5-5 mg ml-1), did not stimulate the intracellular proliferation of L. pneumophila. The reduction of intracellular iron availability by treatment with antibodies against transferrin receptor or with desferrioxamine suppressed the growth of L. pneumophila within BALB/c TG macrophages, suggesting that these cells do not restrict L. pneumophila growth because of iron. The production of nitric oxide was also similar in both macrophage populations, as measured by the Griess reaction. However, the synthesis of oxygen reactive species was three times higher in non-permissive BALB/c macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Macrophage permissiveness for Legionella pneumophila growth modulated by iron.

We have investigated the modulation of iron in two populations of macrophages which differ in susceptibility to Legionella pneumophila intracellular proliferation. Previously, we reported that thioglycolate-elicited peritoneal macrophages obtained from the inbred A/J mouse strain readily support the intracellular growth of L. pneumophila, while resident macrophages from the same strain do not. In this study, we show that A/J elicited macrophages exhibit markedly higher expression of transferrin receptor and intracellular iron content than A/J resident macrophages. Furthermore, apotransferrin and desferrioxamine inhibited the intracellular proliferation of L. pneumophila in elicited macrophages, and this suppression was reversed by the additions of Fe-transferrin or ferric nitrilotriacetate. Fe-transferrin and ferric nitrilotriacetate did not further increase the intracellular proliferation of L. pneumophila in thioglycolate-elicited macrophages. However, ferric citrate and ferric nitrilotriacetate stimulated in a dose-dependent manner the growth of L. pneumophila in resident macrophages. Furthermore, equimolar concentrations of desferrioxamine reversed the stimulatory effect of iron in these resident cells. These data provide evidence supporting the hypothesis that differences in susceptibility to L. pneumophila growth between permissive elicited macrophages and nonpermissive resident macrophages from the A/J mouse strain are due to intracellular availability of iron.

Animals↗
PubMed1994

Inhibition of Legionella pneumophila growth by gamma interferon in permissive A/J mouse macrophages: role of reactive oxygen species, nitric oxide, tryptophan, and iron(III).

A/J mouse macrophages infected with Legionella pneumophila and treated with gamma interferon (IFN-gamma) in vitro developed potent antimicrobial activity. This antilegionella activity was independent of the macrophage capacity to generate reactive oxygen intermediates, since the oxygen radical scavengers catalase, superoxide dismutase, mannitol, and thiourea had no effect on the antilegionella activity of IFN-gamma-activated macrophages. Likewise, whereas the ability of IFN-gamma-activated macrophages to synthesize reactive nitrogen intermediates was markedly inhibited by the L-arginine (Arg) analogs, NG-monomethyl-L-arginine and L-aminoguanidine, as well as by incubation in L-Arg-free medium, their ability to inhibit the intracellular growth of L. pneumophila remained intact. The intracellular growth of L. pneumophila in A/J macrophages was inhibited by the iron(III) chelator desferrioxamine and reversed by Fe-transferrin as well as by ferric salts. Additionally, IFN-gamma-activated macrophages incorporated 28% less 59Fe(III) compared with nonactivated cells. Nonetheless, only partial blocking of growth restriction was observed when IFN-gamma-stimulated macrophages were saturated with iron(III). Indole-propionic acid, which appears to inhibit the biosynthesis of L-tryptophan (L-Trp), was an L-Trp-reversible growth inhibitor of L. pneumophila in macrophages, implying that the intracellular replication of this pathogen is also L-Trp dependent. However, an excess of exogenous L-Trp did not reverse the growth inhibition due to IFN-gamma, though a small synergistic effect was observed when the culture medium was supplemented with both iron(III) and L-Trp. We conclude that IFN-gamma-activated macrophages inhibit the intracellular proliferation of L. pneumophila by reactive oxygen intermediate- and reactive nitrogen intermediate-independent mechanisms and just partially by nutritionally dependent mechanisms. We also suggest that additional mechanisms, still unclear, may be involved, since complete reversion was never obtained and since at higher concentrations of IFN-gamma, iron(III) did not induce any significant reversion in the L. pneumophila growth inhibition.

Animals↗
PubMed1994

Swallowing assessment in primary brain tumor patients with dysphagia.

Dysphagia is a common problem in patients with neurologic disease and is often associated with significant morbidity and mortality. To evaluate primary brain tumor patients who complained of dysphagia, we adapted grading scales for severity of complaint and level of alertness (scale of 1 to 4) and bedside swallowing assessment and videofluoroscopic examination (scales of 1 to 5). Over 13 months, we prospectively screened 117 patients for dysphagia. Seventeen of these (14.5%) complained of dysphagia (mean age, 50.2 years; range, 20 to 75); an additional six control patients were studied from a group with no dysphagic complaints. Scoring for severity of complaint (mean, 2.3) and level of alertness (mean, 2.2) was mild-moderate in the majority of patients. Eleven of 17 patients scored > or = grade 3 (mean 3.2, moderate impairment, requiring supervision) on bedside testing, and six of seven scored > or = grade 3 (mean 3.8, moderate-moderately severe abnormality, trace or frequent aspiration) during videofluoroscopic evaluation. Bedside testing scores of the study group differed significantly (p < 0.001) from those of the control group. Level of alertness correlated strongly with bedside (r = 0.794) and videofluoroscopic (r = 0.780) scoring. Primary brain tumor patients with dysphagia are likely to have impairment of swallowing out of proportion to their complaints and therefore are at risk for aspiration and nutritional compromise. We recommend that these patients undergo formal swallowing assessment followed by rehabilitation or implementation of alternative feeding methods.

Adult↗
PubMed1994

Octreotide exerts different effects in vivo and in vitro in Cushing's disease.

The effect of the long-acting somatostatin analog octreotide (SMS 201-995) on adrenocorticotropin (ACTH) secretion was studied in five patients with untreated Cushing's disease in vivo and in six human corticotropic adenoma cell cultures in vitro. For the in vivo study, 100 micrograms of octreotide sc was given 30 and 180 min after cannulation of the cubital vein and 100 micrograms of corticotropin-releasing hormone (CRH) was injected iv at 210 min. Serum ACTH and cortisol levels were measured for 390 min. In vivo, octreotide had no significant effect either on basal or CRH-stimulated ACTH levels and did not influence cortisol levels. The in vitro studies were conducted with corticotropic adenoma cell cultures derived from adenoma tissue obtained from six patients with Cushing's disease. In four of six cell cultures, octreotide (1 nmol/l-1 mumol/l) inhibited basal ACTH secretion in a dose-dependent manner. The inhibition ranged from 70 to 92% for 1 nmol/l octreotide to 14-46% for 1 mumol/l octreotide as compared to controls (100%). In three of three octreotide-responsive adenoma cell cultures investigated. CRH-stimulated ACTH secretion was suppressed by octreotide. Hydrocortisone pretreatment in vitro abolished the inhibitory effect of octreotide on ACTH secretion in one octreotide-responsive corticotropic adenoma cell culture. In conclusion, we showed that octreotide in most cases could inhibit the ACTH release from human corticotropic adenoma cells in vitro but had no suppressive effect on ACTH levels of patients with Cushing's disease in vivo. This discrepancy could be due to a somatostatin receptor down-regulation by cortisol at the hypercortisolemic state in vivo.

Adrenal Cortex Neoplasms↗
PubMed1994

Hospital records--asset or liability?

Health records of different sorts have been shown--in one region--to cost 13m pounds a year, and to take up 10 miles of shelving. Across one region, records would take up the length of the M4. Terry Gould and colleagues describe a project to establish some protocols for sensible record keeping.

Costs and Cost Analysis↗
PubMed1994

Nursing case management: enhancing interdisciplinary care of the spinal cord injured patient.

Comprehensive care of the person with a spinal cord injury (SCI) requires collaborative, coordinated, interdisciplinary care. It is imperative that the care provided by nurses, therapists, physicians, and ancillary personnel is organized and integrated in a holistic manner if optimal outcomes of rehabilitation are to be achieved. Nursing case management has been identified as an approach to health care delivery that provides quality, patient-centered care. The potential impact of this care delivery model on the health care system for persons with SCI includes quality rehabilitation outcomes, increased patient satisfaction, enhanced interdisciplinary relationships, and improved continuity of care from intensive care to community settings.

Humans↗
PubMed1994

delta 9-Tetrahydrocannabinol enhances the secretion of interleukin 1 from endotoxin-stimulated macrophages.

Interleukin (IL) 1 is a pleiotropic cytokine and an important mediator of various physiological responses including the acute phase response, inflammation, lymphocyte function and certain central nervous system responses. Because delta 9-tetrahydrocannabinol (THC) treatment also has been reported to affect these physiological responses, we tested the drug effect on IL1 production and secretion. Addition of THC to endotoxin (ETX)-treated murine, resident peritoneal macrophage cultures increased, in a dose-dependent manner, supernatant IL1 activity over ETX only treatment. Treatment with THC alone had no effect. Enzyme-linked immunosorbent assay studies and specific antibody neutralization studies demonstrated both IL1 alpha and IL1 beta were increased by drug treatment. The steady-state levels of cellular IL1 alpha and IL1 beta mRNAs, determined by Northern blotting and reverse transcription-polymerase chain reaction, were unchanged, suggesting the possibility THC was not increasing IL1 production. To examine this possibility further, ETX-activated macrophages, pulsed-labeled with 35S-methionine, were chased for 2, 4 and 6 hr in the presence of THC and the levels of the various IL1 bioforms determined by immunoprecipitation. These results showed THC treatment had no effect on the level of ETX-induced intracellular promature IL1 alpha and IL1 beta proteins; however, a THC-induced increase and prolongation of release of promature IL1 alpha and mature IL1 beta were observed. The immunoprecipitation results were confirmed by studies examining supernatant bioactivity. These results suggest THC augments the ETX-induced processing of IL1 beta and release of IL1 alpha rather than increasing the cellular production of IL1 protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The accuracy of computerized prediction of the soft tissue profile: a study of 25 patients treated by means of the Le Fort I osteotomy.

This study was performed to compare the soft tissue movements in facial profile predicted by a computer package with those that had actually occurred following a maxillary advancement osteotomy. The source of the material was serial lateral cephalograms for 25 consecutive patients who had received similar Le Fort I osteotomies primarily to correct an anteroposterior skeletal discrepancy. Many of the digitized points on the soft tissue profile were surprisingly well predicted by the computer package. The chin and profile changes resulting from mandibular autorotation and/or a genioplasty were generally predicted accurately. However, in some cases prediction was less consistent, particularly in the region of the nose and upper lip. In this latter group of patients, initial size, thickness, and morphology of the soft tissues appeared to be important factors to which some consideration could be given in the further refinement of this type of software.

Adolescent↗
PubMed1994

Uncertainty: strategies for patients with brain tumor and their family.

Patients diagnosed with a brain tumor and their families are faced with uncertainties that result from the progression of the disease and treatment regimen. Many strategies can be used to help patients and families deal with these uncertainties. A case report is used to illustrate how changing needs of a patient and family were met by using different strategies.

Adaptation, Psychological↗