As the public expect and deserve higher and higher standards and the health services become more aware of their financial limitations, the constant need for dentists to re-appraise their own professionalism throughout life becomes all the more important. This article, taken from a presidential address, discusses what is meant by professionalism and looks into some of the implications that it holds for dentists now and in the future.
View Article and Find Full Text PDFThe objective of this study was to investigate the regulation of endothelial nitric oxide (NO) synthase by NO. Partially purified endothelial NO synthase was exposed to authentic NO (10-200 microM) and to the nitrovasodilators sodium nitroprusside (SNP; 10-1,000 microM) and S-nitroso-N-acetylpenicillamine (SNAP; 100-1,000 microM), and enzyme activity was assayed by measuring the conversion of L-[3H]arginine to L-[3H]citrulline in the presence of added cofactors. NO, SNP, and SNAP inhibited NO synthase activity in a dose-dependent manner, NO being the most potent inhibitor.
View Article and Find Full Text PDFInhalational anesthetics inhibit the nitric oxide (NO)-soluble guanylate cyclase signaling pathway in vascular and neuronal tissues and it has been proposed that this inhibition is due to several mechanisms, which include a direct inhibition of NO synthase. To determine the direct interaction of anesthetics with NO synthase, the effects of halothane, isoflurane and enflurane on NO synthase activity of bovine and rat brains and cultured bovine aortic endothelial cells were investigated. Halothane and enflurane at 1% to 3% concentrations produced no significant effect on crude bovine brain NO synthase activity, as measured by the conversion of L-[3H]arginine to L-[3H]citrulline.
View Article and Find Full Text PDFWe report here the synthesis of iberiotoxin (IbTX), a 37-amino acid peptide containing three disulfide bridges, and a series of mono-looped analogues. All syntheses were conducted using Fmoc chemistry. Synthesis of IbTX gave a product which was indistinguishable from a reference sample in both its physico-chemical properties and its biological activity.
View Article and Find Full Text PDFInt J Oral Maxillofac Implants
August 1995
An international prospective study of Brånemark implants retaining overdentures was conducted at nine clinical centers. One hundred thirty-three subjects were recruited in a 12-month period and provided with 510 implants, 117 of which were in maxillae and 393 were in mandibles. This study reports the 3-year follow-up status of 120 overdentures and 444 implants.
View Article and Find Full Text PDFWe addressed the controversial role of nitric oxide (NO) in bronchial function by an immunohistochemical study of the localization of NO synthase (NOS) and its effector protein, soluble guanylate cyclase, in rat bronchus. For this study, a monoclonal antibody to the bovine constitutive neuronal NOS was developed and characterized. In Western blot analysis, this monoclonal antibody (anti-NOS antibody) reacted with bovine cerebellum NOS (150 kDa) as well as with structurally different NOSs from cultured bovine aortic endothelial cells (130 kDa) and cultured RAW 264.
View Article and Find Full Text PDFExpression and localization of nitric oxide synthase (NOS) in the lungs of chronically hypoxic and normoxic rats were studied using both immunohistochemistry and NADPH diaphorase (NADPH-d) staining techniques. In the normoxic and in the hypoxic rat, NOS was detected by both methods in the endothelium of large pulmonary vessels and in the epithelium of bronchi and bronchioli. NOS expression was not detected in the endothelium of normoxic pulmonary resistance vessels but was prominently expressed in the endothelium of these vessels after 2-4 wk of chronic hypoxia.
View Article and Find Full Text PDFBiochem Pharmacol
July 1994
The effect of H2O2 and catalase on isolated rat cerebellum nitric oxide (NO) synthase activity was determined by measuring the conversion of L-[3H]arginine to L-[3H]citrulline. H2O2 (1-5 mM) markedly increased NO synthase activity in the presence of endogenous catalase (72 +/- 4 U/mL). This effect of H2O2 was further increased by exogenous catalase (200 U/mL).
View Article and Find Full Text PDFThe significance of tightening abutment screws and gold cylinders to osseointegrated fixtures with the correct torque is demonstrated, and a simple relationship between applied torque and screw preload is derived by use of mechanical engineering principles. The principles of a number of tightening methods are outlined and assessments made of their accuracy. The difference between optimum and design torque is highlighted.
View Article and Find Full Text PDFType II (inducible) nitric oxide synthase (NOS) may play an important role in pulmonary pathophysiology, yet it remains controversial whether human tissues are capable of expressing this protein. Therefore, a polyclonal antibody (8196) was raised against type II NOS from induced RAW 264.7 macrophages and used to investigate the expression of this enzyme in human lung tissue.
View Article and Find Full Text PDFChronic, recurrent low back pain, although one of the most commonly encountered medical conditions in the workplace, is one of the most difficult to manage. With the passage of the Americans with Disabilities Act, the proper management of the worker with recurrent low back pain poses an even greater challenge. We propose an interdisciplinary methodology to evaluate the worker at high medical risk of recurrent low back pain and determine the potential ergonomic risks of essential function tasks in material-handling work.
View Article and Find Full Text PDFCompetitive swimmers commonly focus upon optimising performance at a single competition. A period where training volume is incrementally reduced or "tapered" often precedes such a competition. The use of taper is justified as increases in muscular power, and the restoration of plasma haematocrit, haemoglobin and creatine kinase are evident with this training reduction.
View Article and Find Full Text PDFCathet Cardiovasc Diagn
February 1994
A 31-year-old woman developed increasing signs of congestive heart failure 15 years following placement of a mitral Starr-Edwards mechanical valve. A preoperative transesophageal echocardiogram (TEE) demonstrated a large, obstructive valvular thrombus and the patient underwent successful reoperative valve replacement.
View Article and Find Full Text PDFBackground: Inhaled nitric oxide (NO), an endothelium-derived relaxing factor, is a selective pulmonary vasodilator. The authors investigated whether inhaled NO decreases pulmonary vascular resistance (PVR) while preserving hypoxic pulmonary vasoconstriction and whether it maintains or improves oxygenation in patients during one-lung ventilation.
Methods: In supine cardiac surgical patients with a normal mean pulmonary artery pressure (PAP) (< 25 mmHg, n = 10) or a moderately elevated PAP (25-35 mmHg, n = 10), one-lung ventilation was established with 80% oxygen and 20% nitrogen followed by the same gas mixture containing 20 ppm NO for 6 min.
Int J Oral Maxillofac Implants
May 1994
Sixty-one patients participated in a longitudinal study designed to compare the psychological effects of osseointegrated implants with those of conventional denture replacements. Thirty-two patients who requested either relining or reconstruction of their dentures were asked to complete questionnaires designed to measure their psychological well-being while they were on a waiting list and then again 6 months after treatment. Their responses were compared with those of 29 patients who had received an osseointegrated implant.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
December 1993
Although superoxide anion is known to inactivate nitric oxide (NO) once formed, its effect on NO synthesis is unclear. In this study, xanthine oxidase-hypoxanthine, a superoxide anion generating system, inhibited bovine cerebellum NO synthase activity as measured by the conversion of L-[3H]arginine to L-[3H]citrulline. This inhibition by xanthine oxidase was concentration-dependent.
View Article and Find Full Text PDFA series of peptides and phosphopeptides corresponding to the auto-phosphorylation site of pp60src, -Asn-Glu-Tyr416-Thr-Ala-, were prepared by either Boc/solution or Fmoc/solid phase peptide synthesis and used as substrates to study their enzymatic phosphorylation by various casein kinases. The Tyr(P)-containing peptide, Asn-Glu-Tyr(P)-Thr-Ala, was prepared by the use of Fmoc-Tyr(PO3Bzl2)-OH in Fmoc/solid phase peptide synthesis followed by acidolytic treatment of the peptide-resin with 5% anisole/CF3CO2H. Both Asn-Glu-Tyr-Thr-Ala and Asn-Glu-Ser(P)-Thr-Ala were prepared by the Boc/solution phase peptide synthesis and employed hydrogenolytic deprotection of the protected peptides.
View Article and Find Full Text PDFThe vascular response to hypoxia in endotoxin (lipopolysaccharide; LPS)-exposed rat pulmonary artery (PA) and thoracic aorta (AO) was investigated and the mechanism of the observed hypoxic responses defined. In isometric tension studies, LPS-treated AO and PA rings, with and without endothelium, demonstrated decreased (P < 0.05) contractile response to phenylephrine (PE EC50), and the dose response was shifted to the right (P < 0.
View Article and Find Full Text PDFClin Oral Implants Res
September 1993
The surfaces of titanium (Ti) plates, as models for Ti implants, have been characterized by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF SIMS). Plates were prepared with rough and smooth surface topographies--the rough being similar to that of an implant. The XPS data has been used to construct a model of the plates' surface chemical structure, from the gas-solid interface through to pure Ti metal.
View Article and Find Full Text PDFJ Appl Physiol (1985)
September 1993
Inhaled nitric oxide (NO) is a vasodilator selective to the pulmonary circulation. Using isolated rat lungs, we determined the dose-response relationship of NO and the role of blood in mediating pulmonary vasodilation and selectivity. Inhaled 20, 50, 100, and 1,000 ppm NO attenuated (P < 0.
View Article and Find Full Text PDFWe investigated the effects of 14 d of resistive exercise detraining on 12 power athletes. In comparing performances pre- to post-detraining, there were no significant (P > 0.05) changes in free weight bench press (-1.
View Article and Find Full Text PDFThe derivative N alpha-fluorenylmethoxy-carbonyl-O-dimethylphosphono-L-tyrosi ne was utilized in continuous-flow solid-phase synthesis to prepare the O-phosphotyrosine analogue of human angiotensin II, [Tyr(P)4] angiotensin II. Side-chain deprotection, including the removal of the methyl phosphate groups, as well as cleavage of the peptide from the solid support was achieved with 1 M trimethylsilyl-bromide-thioanisole in trifluoroacetic acid. Overall yield of purified peptide was 46%.
View Article and Find Full Text PDFNitric oxide (NO) is a recently discovered messenger for the activation of soluble guanylate cyclase in a wide variety of cell types. Although enzymes involved in NO synthesis have been discovered, the regulation of their action is not clear. The possibility of NO regulating the activity of a crude NO synthase (EC 1.
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