Biomedical subjects

J J Murray

Publications and source records attributed to J J Murray.

At least 127 records · Page 7Linked to original sources

PubMed1993

General anesthesia and children's dental health: present trends and future needs.

Attitudes toward general anesthesia and patterns of dental disease in children have changed markedly over the past 20 years. This paper reviews past and present trends to estimate future needs of general anesthesia for school-aged children. The impact of the Poswillo report on general dentistry, sedation, and resuscitation in dentistry is discussed along with the changes in patterns of dental health of children.

Adolescent↗

PubMed1993

Reproduction of the obliterative bronchiolitis lesion after heterotopic transplantation of mouse airways.

Obliterative bronchiolitis, characterized histopathologically by airway inflammation and occlusion of small airways by vascularized fibrous tissue, constitutes an important threat to the long-term survival of lung and heart-lung transplant recipients. The pathogenesis of obliterative bronchiolitis is poorly understood, and successful preventative or treatment strategies are not available. We sought to develop a preclinical model system of obliterative bronchiolitis by transplanting murine airway grafts, consisting of tracheas and main bronchi, into the subcutaneous tissue of allogeneically mismatched recipient animals. By 10 days after transplantation, allografts demonstrated subepithelial and/or peritracheal inflammation, epithelial necrosis, and early fibroproliferation. Grafts harvested 21 days after transplantation demonstrated fibroproliferation in the airway wall or lumen in nine of 10 allografts versus 0 of 10 isografts (P = 0.0001). In addition, abnormal epithelium (ie, nonciliated cuboidal, squamous, or absent) was seen in all allografts, while nine of nine isografts demonstrated normal respiratory epithelium (P = 0.0003). Although differences exist between this model and the chronic rejection process in human lung transplant recipients, these findings reproduce the characteristic features of obliterative bronchiolitis and demonstrate that this lesion can result from allograft rejection. This model will be useful for studying the pathogenesis, prevention, and treatment of obliterative bronchiolitis after lung transplantation.

Animals↗

PubMed1992

The British Dental Journal: a report on its activities 1986-1991.

The contents of 139 issues of the British Dental Journal, published between January 11, 1986 and December 1991, have been analysed. Part I of the Journal contains, on average, one Leader, eleven items of news and notes, 12 letters and eight abstracts/book reviews. One thousand, three hundred and seventeen manuscripts were submitted for publication during the 6-year period. Of these, 403 original articles, 119 case reports and 203 review articles were accepted and published in Part II. Part III of the Journal is devoted to annual and other reports and policy documents, worldwide dentistry, practice management and vocational training, dental electives, trade news, meeting reports and obituaries. Over 40 'strap headings' denoting specialised areas of dentistry were used to describe articles published. Almost one-fifth of the papers were concerned with restorative dentistry. Case reports comprised 14% of the papers published. Oral surgery/oral medicine/oral pathology, and related subjects accounted for nearly 15% of papers published. Articles concerned with community dental health, orthodontics and paediatric dentistry accounted for a similar proportion of the total, as did the section comprising general dental practice, vocational training and practice management. Anaesthesia, analgesia, medical topics, microbiology and therapeutics took up 12% of articles published. The remaining 12% consisted of articles on dental education and research, oral biology, dental history, auxiliaries, dental instruments and diagnostic aids.

Humans↗

PubMed1992

Crohn's disease and carcinoma: increasing justification for surveillance?

Carcinoma of the colon that arises in patients with Crohn's disease is being reported with increasing frequency. To help clarify the nature of this association, records of 25 patients with Crohn's disease and colorectal carcinoma seen from 1957 through 1989 were reviewed. One patient had leiomyosarcoma of the rectum, and two patients had the onset of Crohn's disease after the diagnosis and treatment of colorectal carcinoma. Therefore, 22 patients were available for complete retrospective analysis. The median age at diagnosis of Crohn's disease was 37 years (range, 15-67 years), and the median age at diagnosis of carcinoma was 54.5 years (range, 32-76 years). The median duration of symptoms preceding the discovery of colorectal carcinoma was 18.5 years (range, 0-32 years). Carcinoma arose in colonic segments with known Crohn's disease in 77 percent of patients, and six patients (27 percent) had associated colonic mucosal dysplasia. One lesion was classified as Dukes A, nine lesions were Dukes B, five lesions were Dukes C, and seven lesions were Dukes D. Patients with an onset of Crohn's disease before the age of 40 years had primarily Dukes C or D lesions and consequently poor survival. Most patients presented with nonspecific signs and symptoms, with nothing to distinguish the activity of the Crohn's disease from the presence of colorectal neoplasm. Younger patients with long-standing Crohn's disease should be considered for colonic surveillance to permit earlier diagnosis and treatment of potential colorectal carcinoma.

Adolescent↗

PubMed1992

Factors predictive of persistent or recurrent Crohn's disease in excluded rectal segments.

The fate of the excluded rectal segment after surgery for Crohn's colitis remains poorly defined. To determine prognostic factors relating to the fate of the rectal segment, records of 47 patients who underwent creation of an excluded rectal segment were studied. Disease developed in 33 patients (70 percent) in the excluded rectal segment by five years; 24 patients (51 percent) had completion proctectomy by 2.4 years; and 9 patients (19 percent) retained a rectum with disease at a median follow-up period of five years (range, 2-13 years). At a median follow-up time of six years (range, 2-21 years), 14 patients were without clinical disease. The three groups were equivalent with respect to sex, duration of preoperative disease, indication for operation, distribution of disease, and histologic involvement of the proximal rectal margin. The median age of patients in the proctectomy group at diagnosis tended to be younger than that of patients with a retained excluded rectal segment (22, 30, and 31 years for patients having proctectomy, patients with a diseased excluded rectal segment, and patients with a normal excluded rectal segment, respectively). Neither initial involvement of the terminal ileum nor endoscopic inflammatory changes seen in the rectum predicted eventual disease of the excluded rectal segment. However, initial perianal disease complicating Crohn's colitis was predictive of persistent excluded rectal segment disease and often required proctectomy. Therefore, because the presence of perianal disease and Crohn's colitis predicts persistent or recurrent excluded rectal segment disease, primary total proctocolectomy or early completion proctectomy may be indicated in this subgroup of patients.

Adolescent↗

PubMed1992

Anastomotic-vaginal fistula after colorectal surgery.

The most feared complication of anterior and low anterior resection is anastomotic dehiscence. Although most leakages remain clinically silent, some may lead to formation of a colovaginal fistula. At the Lahey Clinic Medical Center, the records of nine patients with colovaginal fistula as a complication of colorectal surgery were reviewed to determine clinical characteristics and optimal management. The mean age was 63.7 years (range, 47-72 years). The initial indications for surgery were carcinoma of the rectum (n = 4), diverticular disease (n = 3), and closure of the colostomy after Hartmann's procedure (n = 2). Hysterectomy had been performed earlier in seven patients (78 percent). The end-to-end anastomosis (EEA) stapling device was used in five patients, and four patients had a handsewn anastomosis. The fistula developed within 23 days after surgery and usually originated within 8 cm of the anal verge. Two patients underwent immediate diverting transverse colostomy. None of the seven patients who were initially managed medically had spontaneous closure of the fistula. High fistulas were successfully treated by colorectal resection in two patients, whereas low fistulas healed after transanal repair without colostomy in two patients. These results suggest that previous hysterectomy predisposes to development of a colovaginal fistula after colorectal surgery. Not all patients require fecal diversion. Colorectal resection for high fistulas and transanal repair for low fistulas appear to be viable options for treatment.

Aged↗

PubMed1992

Role of perfluorochemical emulsions in the treatment of myocardial reperfusion injury.

Perfluorochemicals are substances with small particle size, low viscosity, and high oxygen-carrying capacity. The role of one perfluorochemical preparation. Fluosol, an emulsion of two perfluorocarbons, a detergent Pluronic F-68 (poloxamer 188), and phospholipids on myocardial reperfusion injury was investigated in a closed-chest canine model of regional ischemia. Intracoronary and intravenous infusions of Fluosol in the perireperfusion period significantly reduced infarct size and improved ventricular function in animals that were examined for up to 2 weeks after reperfusion. Fluosol preserved endothelial structure and endothelium-dependent relaxation of large and small vessels. Fluosol reduced neutrophil plugging of capillaries and attenuated neutrophil infiltration into the reperfused bed. Ex vivo studies of neutrophil function demonstrated apparent suppression of chemotaxis and lysozyme degranulation in cells from animals that were treated with Fluosol. However, treatment of cells in vitro manifested enhanced superoxide anion production within 5 minutes of incubation even with low concentrations of Fluosol. This effect was found to be almost entirely attributable to the detergent, Pluronic F-68. The stimulation of neutrophils by Fluosol was found to result directly from phagocytosis and indirectly from activation of the complement cascade. These findings suggest that perfluorochemicals may provide a novel form of therapy to enhance myocardial salvage after successful reperfusion. The mechanism appears to be due to stimulation and subsequent "deactivation" of neutrophils peripherally, which thereby reduces their cytotoxic potential in the reperfused myocardium. The role of the oxygen-carrying ability of the perfluorocarbons in the reduction of reperfusion injury remains to be determined. In a pilot study in human beings, Fluosol that was used as adjunctive therapy with angioplasty has also been shown to improve regional ventricular function. Clinical trials with perfluorochemical emulsions appear warranted to determine the role of reperfusion injury in limiting myocardial salvage in patients who are undergoing pharmacologic or mechanical reperfusion.

Animals↗

PubMed1992

Pharmacologic perturbation of neutrophils by Fluosol results in a sustained reduction in infarct size in the canine model of reperfusion.

Previous studies have demonstrated that intravenous administration of large doses of Fluosol, a perfluorochemical preparation, reduced infarct size 24 h after reperfusion, an effect that was associated with reduced neutrophil infiltration. The effect of a clinically tolerable dose of Fluosol on infarct size after a prolonged period of reperfusion and its mechanism of action on neutrophils remain unknown. Twenty-one anesthesized closed chest dogs were subjected to 90 min of proximal left anterior descending coronary artery occlusion and 72 h of reperfusion. An additional five dogs that did not undergo regional myocardial ischemia were utilized to explore the mechanism of action of Fluosol on neutrophil function. In the infarct study, animals were randomized to receive either intravenous Fluosol (n = 10) or an equivalent volume of Ringer's lactate solution (control; n = 11) at 15 ml/kg body weight during the last 30 min of occlusion and for the 1st 30 min of reperfusion. Fluosol significantly reduced infarct size when expressed as percent area at risk 72 h after reperfusion (13.7 +/- 2.7% vs. 38.3 +/- 4.5%, respectively, p less than 0.001). This reduction was associated with significant improvement in regional wall motion (18.4 +/- 2.3% vs. 5.5 +/- 2%, p less than 0.001). Endocardial blood flow in the ischemic bed was significantly higher 3 h after reperfusion in Fluosol-treated dogs (0.63 +/- 0.08 vs. 0.34 +/- 0.07 ml/min per g, p = 0.01). Reduced capillary plugging by neutrophils with relative preservation of endothelial cell structure was observed in Fluosol-treated animals. Infusion of Fluosol produced a marked transient decrease in peripheral neutrophil and platelet counts in both ischemic and nonischemic dogs and was associated with a significant reduction in total hemolytic complement levels. Studies of neutrophil function ex vivo revealed a reduction in chemotaxis and lysozyme degranulation after infusion of Fluosol. In vitro experiments showed that Fluosol produced a rapid and sustained activation of neutrophils determined by superoxide anion production. These data demonstrate that low dose intravenous Fluosol produces a sustained reduction in infarct size in the canine model. The beneficial effect may be in part due to the suppression of various neutrophil functions in the reperfused myocardium subsequent to peripheral activation by Fluosol. Such interventions may offer a novel therapy to enhance myocardial salvage by sequestration of circulating neutrophils during the critical early reperfusion period.

Animals↗

PubMed1992

Regulation of phosphatidic acid phosphohydrolase activity during stimulation of human polymorphonuclear leukocytes.

Phosphatidic acid phosphohydrolase (PPH) activity was determined in human polymorphonuclear leukocytes (PMNs) by measuring the hydrolysis of [32P]phosphatidic acid (PA) added to cell sonicates. Enzyme activity was localized primarily to a soluble fraction. Soluble and particulate activities required magnesium and were inhibited by calcium, N-ethylmaleimide, sphingosine, and propranolol. The activity in unstimulated PMNs was 0.64 +/- 0.11 nmol of PA hydrolyzed.mg protein-1.min-1 in particulate and 4.20 +/- 0.42 in soluble fractions. Stimulation of PMNs with 1 microM f-Met-Leu-Phe (FMLP) for 10 min caused a slight decrease in soluble activity and a small increase in the activity of particulate fractions. Preincubation with 10 microM cytochalasin B for 5 min before FMLP stimulation markedly enhanced both of these changes. The effect of FMLP plus cytochalasin B was rapid (less than 10 s), whereas the calcium ionophore A23187 (1 microM) and phorbol myristate acetate (100 ng/ml) caused slower and smaller changes in enzyme activity. These results indicate that after chemoattractant stimulation; PPH activity decreases in the soluble fraction and increases in the particulate fraction suggesting that PPH may participate in signal transduction in the PMN.

Calcimycin↗

PubMed1992

The child as a dental patient.

The management of children's anxiety continues to be at the focal point of research into the child as a dental patient. This review is concerned first with different psychological concepts of anxiety, including psychoanalytic approaches, infant attachments, and behavioral and cognitive approaches. Incidents contributing to fear of dentistry and strategies used to manage anxiety and behavioral problems are then considered. The next section deals with coping mechanisms children devise to deal with anxiety-provoking situations. Finally, some comments are made on groups of children with special needs. The decline in caries and an increase in the awareness by dentists of the psychological needs of children should enable the next generation to be less fearful and more positive about the benefits of good dental health.

Adaptation, Psychological↗

PubMed1992

Phagocytic activation of human neutrophils by the detergent component of fluosol.

Fluosol (Alpha Therapeutic Corporation, Los Angeles, CA) an emulsion of perfluorocarbons with a high oxygen-carrying capacity, was approved as an adjunct to alleviate myocardial ischemia during coronary angioplasty. This drug also significantly enhances myocardial salvage presumably related to an action on the neutrophil. The mechanism by which fluosol and its individual components, including the detergent Pluronic F-68, affected neutrophil function was examined. During the incubation of neutrophils with fluosol, a rapid stimulation of superoxide anion production and degranulation which progressively increased over a 30-minute period was detected. Neutrophils incubated with only Pluronic F-68 produced similar amounts of superoxide anion. Cytochalasin B, an inhibitor of phagocytosis, significantly inhibited this superoxide anion generation. As shown previously, neutrophils incubated with fluosol for 30 minutes and then subsequently stimulated manifested a reduction in lysozyme release as compared with untreated cells. Results of an electron microscopic examination confirmed the cellular uptake of the fluosol within phagocytic vacuoles. Neutrophil viability determined by trypan blue was unaffected after fluosol treatment. These observations show that the fluosol emulsion, primarily through micelles formed by the detergent Pluronic F-68, activates human neutrophils by serving as a phagocytic stimulus, which produces a cell refractory to subsequent stimulation.

Blood Substitutes↗

PubMed1992

The prevalence of developmental defects of enamel in 15-16-year-old children residing in three districts (natural fluoride, adjusted fluoride, low fluoride) in the north east of England.

Developmental defects of enamel were assessed in 15-year-old children born and continuously resident in three communities in the north east of England. In naturally fluoridated Hartlepool (F = 1.0-1.3 ppm), artificially fluoridated Newcastle (F = 1.0 ppm) and non-fluoridated Middlesbrough (F < 0.2 ppm) 361, 356 and 376 children respectively were examined. Conventional clinical recording and a photographic technique where colour slides are assessed at random were used and compared. Scoring in both assessments was done by using a modified version of both the Murray and Shaw index and the developmental defects of enamel index. In the clinical assessment more white lines and diffuse opacities were found in the fluoridated areas than in the non-fluoridated area. More opacities were recorded using the photographic assessment than with the clinical assessment, but a similar trend of an increased prevalence of white lines and diffuse opacities was observed using the photographic method. Overall, there was only a small increase in the prevalence of milder forms of enamel defects in fluoridated compared with non-fluoridated areas.

Adolescent↗

PubMed1991

The effect of residence and social class on dental caries experience in 15-16-year-old children living in three towns (natural fluoride, adjusted fluoride and low fluoride) in the north east of England.

Caries experience in 1374 children aged 15-16 years from three towns in the north east of England with varying concentrations of fluoride in drinking water, was determined. The mean DMFT values for 15-year-old continuous residents was 1.7 in Hartlepool (natural F 1.0-1.3 ppm), 2.5 in Newcastle (F adjusted to 1.0 ppm) and 3.3 in Middlesbrough (F = 0.2 ppm). Forty per cent of Hartlepool 15-year-olds were caries free, compared with 30% in Newcastle and 24% in Middlesbrough. Caries prevalence for both Hartlepool and Newcastle 'continuous residents' was lower than for non-continuous residents, whereas in Middlesbrough, the low fluoride area, non-continuous residents had a lower DMF value than those who had lived in Middlesbrough all their lives. There was a slight trend in both Newcastle and Middlesbrough for DMFT values to increase from social class I to social class V, but no discernable trend was observed in Hartlepool. The results for Hartlepool 15-year-olds were very similar to those reported by Weaver in 1949.

Adolescent↗

PubMed1991

Differential effects of propranolol on responses to receptor-dependent and receptor-independent stimuli in human neutrophils.

Recent evidence suggests that the hydrolysis of phosphatidylcholine (PC) by phospholipase D (PLD) may mediate superoxide anion (O2-) production in human neutrophils. To define the role of the PC-specific PLD products phosphatidic acid (PA) and diacylglycerol (DAG) in O2- production in response to agonists which activate the PLD pathway, we blocked the metabolism of PA to DAG with propranolol, an inhibitor of PA phosphohydrolase. Propranolol (150 microM) enhanced the production of O2- in response to the receptor agonists n-formyl-methionyl-leucyl-phenylalanine (FMLP, 292 +/- 94% of controls), platelet-activating factor (PAF, 932 +/- 215%) and leukotriene B4 (LTB4, 1305 +/- 475%). In the presence of propranolol, total O2- production in response to PAF and LTB4, which are potent priming stimuli but very weak direct agonists, was similar to that obtained with FMLP. IN contrast, responses to receptor-independent agonists phorbol myristate acetate (PMA) and ionomycin were inhibited (81 +/- 8% and 87 +/- 5% inhibition, respectively). The effects of propranolol were demonstrable in the absence of cellular calcium and were shared by both stereoisomers of the drug. These data are consistent with the hypothesis that PA produced through the hydrolysis of PC by PLD is an important mediator of O2- production in response to receptor-dependent agonists. However, the inhibitory effects of propranolol on receptor-independent stimuli suggest that PA generated through the PLD pathway plays a different role in the signal transduction mechanisms of these agonists or that propranolol may have additional effects beyond inhibition of PA phosphohydrolase.

Calcium↗

PubMed1991

An assessment of dental anxiety in children.

The aims of this study were to assess child behaviour in a dental surgery and to isolate the variables most closely associated with lack of cooperation by means of a questionnaire/interview. Sixty-five children aged 6-18 years, who had been referred to one dentist because of poor cooperation, formed the study group. Forty-two children of similar age, treated by the same dentist, but referred for reasons other than lack of cooperation, acted as the control. Assessments of anxiety were made independently by a psychologist who used a number of indices, including the Child Manifest Anxiety Scale (CMAS), Melamed's Child Behaviour Rating Scale and the Venham Picture Scale. Fifty-one children in the study group had experienced a general anaesthetic for dental treatment compared with five in the control group (P less than 0.001). Parents of children in the study group could identify specific instances which contributed to fear of dentistry in 75% of cases. The CMAS found no difference between the groups in general anxiety, but anxiety and cooperation ratings made by parent and dentist in the dental surgery showed significant differences between the two groups, as did the results of the Venham Picture Scale.

Adolescent↗

PubMed1991

Cloning and expression of a complementary DNA encoding a bovine adrenal angiotensin II type-1 receptor.

Angiotensin II elicits different responses which affect cardiovascular, neuronal and electrolyte transport regulation. To understand the mechanisms responsible for its various actions, the receptor for angiotensin II has long been sought, but numerous attempts to purify the receptor have been unsuccessful owing to its instability and low concentration. We report here the expression cloning of a complementary DNA encoding a bovine angiotensin II receptor to overcome these difficulties. The receptor cDNA encodes a protein of 359 amino-acid residues with a transmembrane topology similar to that of other G protein-coupled receptors. COS-7 cells transfected with the cDNA expressed specific and high-affinity binding sites for angiotensin II, angiotensin II antagonist and a non-peptide specific antagonist for type-1 receptor. Dithiothreitol inhibited ligand binding. The concentration of intracellular Ca2+ and of inositol-1,4,5-trisphosphate increased in the transfected COS-7 cells in response to angiotensin II or angiotensin III, indicating that this receptor is the type-1 receptor for angiotensin II. Northern blot analysis revealed that the messenger RNA for this receptor is expressed in bovine adrenal medulla, cortex and kidney.

Adrenal Cortex↗

PubMed1991

The 5-year results of a clinical trial comparing a glass polyalkenoate (ionomer) cement restoration with an amalgam restoration.

A clinical trial comparing the efficacy of a glass polyalkenoate cement (GPC) restoration with an amalgam cement restoration (ACR) in the management of caries in the deciduous molar dentition was undertaken. Two hundred and thirty-eight restorations, that is 119 pairs, were placed in 76 patients with an age range of 5 to 11 years. The durability of these restorations was assessed during a 5-year follow-up period, using modified United States Public Health Service criteria. The glass polyalkenoate cement restorations occupied 16% of the occlusal surface of the tooth compared to 28% for the amalgam restorations, had a lower median survival time (33.4 [SE 2.26] months compared to 41.4 [SE 2.24] months) and underwent greater loss of anatomical form and marginal integrity than the paired amalgam controls.

Analysis of Variance↗

PubMed1991

Indeterminate colitis predisposes to perineal complications after ileal pouch-anal anastomosis.

This study retrospectively evaluated 288 patients who had undergone ileal pouch-anal anastomosis to determine the incidence of perineal complications and to relate these findings to the pathologic diagnosis, with the goal of specifically clarifying the appropriate surgical management of patients with indeterminate colitis. Of these 288 patients, 235 patients (82 percent) had a diagnosis of chronic ulcerative colitis, 18 patients (6 percent) had indeterminate colitis, 6 patients (2 percent) had Crohn's disease, and 29 patients (10 percent) had familial polyposis. All complications occurred at least 6 months after closure of the stoma and required operative therapy. Of 18 patients with indeterminate colitis, 9 patients experienced complications (50 percent) vs. 8 of 235 patients with chronic ulcerative colitis (3 percent), a highly significant difference (P less 0.001). Furthermore, the risk of eventual ileostomy because of perineal complications was 0.4 percent in patients with chronic ulcerative colitis vs. 28 percent in patients with indeterminate colitis (P less than 0.001). We conclude that a diagnosis of indeterminate colitis predisposes the patient undergoing ileal pouch-anal anastomosis to perineal complications, with a resultant high chance of reservoir loss. Ileal pouch-anal anastomosis should be considered with caution in the patient with a diagnosis of indeterminate colitis.

Abscess↗