ABSTRACT
This work reviews the main undesirable optical effects encountered in case of correction of ametropies by spectacles. It reminds some mechanisms and envisages means we dispose to limit their disaggreable consequences.
Subject(s)
Eyeglasses , Optics and Photonics , Astigmatism/therapy , Color , Equipment Design , Eyeglasses/adverse effects , Humans , Lenses/adverse effects , Light , Refraction, Ocular , Refractive Errors/therapy , Surface PropertiesABSTRACT
Reasons of contra-indications, absolute or relative, of multifocals an progressive glasses may be objective and/or subjective. This work considers some principal of them. Their knowledge and the comprehension of their mechanisms must help the ophthalmologist to understand the reasons of some defeats and to avoid some others.
Subject(s)
Eyeglasses , Accommodation, Ocular , Attitude to Health , Color , Contraindications , Convergence, Ocular , Equipment Design , Eyeglasses/psychology , Facial Asymmetry/physiopathology , Head/anatomy & histology , Humans , Lenses , Nystagmus, Pathologic/physiopathology , Occupations , Optics and Photonics , Orbital Diseases/physiopathology , Posture , Refractive Errors/therapy , Surface Properties , Visual Acuity/physiologyABSTRACT
The introduction of nonpeptide angiotensin II antagonists in clinical use has necessarily led to comparison with the various and clinically established angiotensin converting enzyme inhibitors. In essence, losartan, the first approved angiotensin receptor antagonist, has a clinical profile highly similar to that of the converting-enzyme inhibitors, although much higher doses are required but with the advantage of no dry cough. On the other hand, the emergence of the concept of inverse agonism on other receptor systems has led to the search for pathological situations mediated through constitutive receptor activity as well as antagonists with inverse agonistic properties on the angiotensin receptor. Basic research on angiotensin peptide antagonists has led to the identification of molecular characteristics that produce antagonism. The combination of these characteristics then led to angiotensin antagonists that possessed a long in vivo duration of action. Studies with angiotensin converting enzyme inhibitors and nonpeptide antagonists on animal models of post-angioplastic restenosis revealed that both classes of compounds have similar partial efficacy on the inhibition of neointima formation. A peptide antagonist produced on the rat carotid model a complete inhibition of neointima formation. This increased efficacy is now tentatively attributed to potential inverse agonistic activity of this peptide antagonist. This concept would give angiotensin antagonists therapeutic opportunities where convertase inhibitors should be ineffective.
Subject(s)
Angioplasty, Balloon , Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Antihypertensive Agents/therapeutic use , Carotid Stenosis/prevention & control , Angiotensin II/analogs & derivatives , Animals , Carotid Stenosis/physiopathology , Imidazoles/therapeutic use , Male , Rats , Rats, Sprague-Dawley , Receptors, Angiotensin/physiology , Structure-Activity Relationship , Tetrazoles/therapeutic useABSTRACT
Cerebrovascular disease is a major cause of morbidity and mortality. Approximately 75% to 80% of strokes and transient ischemic attacks are due to vascular disease within the cartoid or cerebral circulation. Of the remaining 20% to 25%, perhaps 50% are due to a cardioembolic event. Transesophageal echocardiography is the best screening test available for an unexplained cerebrovascular event. Anticoagulation with warfarin is indicated in the majority of cases of cardioembolic emboli. Atrial fibrillation is a major risk factor for stroke and prophylactic anticoagulation is warranted.
Subject(s)
Heart Diseases/complications , Intracranial Embolism and Thrombosis/etiology , Echocardiography, Transesophageal , Heart Diseases/diagnostic imaging , HumansABSTRACT
In this paper an in vitro investigation of the biomechanical behavior of the tibiofibular frame in nonunion using electrical extensometry is presented. The intact and untreated nonunited frames are studied as well as three surgical treatments classically used in nonunion: the plating technique, the onlay graft technique and the external fixation according to Ilizarov. The monopodal position with extended knee is considered, and particular attention is paid to the different muscle insertions. The results for the plating and onlay grafting techniques resemble those for the intact frame, whereas the Ilizarov external fixator increases the overall rigidity of the frame. In the untreated nonunited tibiofibular frame, an inversion of the tension and compression areas at the level of the tibia was found. We hypothesize that this phenomenon could be one of the mechanical factors leading to nonunion. Indeed, cyclic stresses in the fracture callus might prevent bony fusion, for the areas healing under compression stresses must become tension areas once the tibia is healed and vice versa.
Subject(s)
Fibula/physiopathology , Fractures, Ununited/physiopathology , Tibia/physiopathology , Tibial Fractures/physiopathology , Biomechanical Phenomena , Bone Plates , Bone Transplantation , External Fixators , Fractures, Ununited/therapy , Humans , Tibial Fractures/therapyABSTRACT
The data on hydrocarbon induced pancreatitis are conflicting. This question was therefore studied in a non-selected population exposed to hydrocarbons and in "formerly" exposed workers. Neither the past clinical history nor the pancreatic tests provided any evidence for a causal relation between exposure and pancreatitis. No signs of hydrocarbon induced liver damage were seen either. As a healthy worker effect cannot be totally excluded, however, a case-control study in a group of patients suffering from non-alcohol induced pancreatitis could give useful indications for finally excluding the possibility of pancreatitis being induced by hydrocarbons.
Subject(s)
Hydrocarbons/adverse effects , Occupational Diseases/chemically induced , Occupational Exposure/adverse effects , Pancreatitis/chemically induced , Alcohol Drinking/adverse effects , Bile Acids and Salts/metabolism , Humans , Male , Pancreatitis/metabolismABSTRACT
This article reports the treatment with continuous ambulatory peritoneal dialysis of a patient with intractable congestive heart failure secondary to an ischemic cardiomyopathy. Although the use of peritoneal dialysis to treat refractory heart failure is not new, the advent of an effective continuous peritoneal dialysis system has allowed its use over prolonged periods of time. The two-year treatment interval described herein represents the longest reported application of this technique, to the best of our knowledge.
Subject(s)
Heart Failure/therapy , Peritoneal Dialysis/methods , Humans , Male , Middle Aged , Peritoneal Dialysis/adverse effects , Peritonitis/etiology , Recurrence , Time FactorsABSTRACT
In relation to cochlear implants, the authors review the various etiologies of deafness in infancy and childhood, either genetic or acquired in order to determine the criteria for advising implantation. They put forward the necessity of complete evaluation of all the auditory pathways involved to determine if a premature who has sustained hypoxicischemic encephalopathy and a full term baby have the same chance to benefit from cochlear implants after meningitis. Defined criteria are urgent needs for patients and parents.
Subject(s)
Cochlear Implants , Deafness/etiology , Auditory Pathways , Child , Child, Preschool , Deafness/diagnosis , Deafness/therapy , Ear/abnormalities , Humans , Infant , Infant, Newborn , Infant, Newborn, Diseases/complications , Infant, Premature, Diseases/complicationsSubject(s)
Crowns , Gutta-Percha , Post and Core Technique , Root Canal Obturation/methods , Dental Bonding , Dental Cavity Preparation , HumansABSTRACT
In the post operative course of a peritonitis, the need for a central venous catheter. A 800 ml hemothorax in the left pleura occurred. It could not be relieved with a chest-tube, and had to be evacuated through a thoracotomy. The risk factors to be considered in this case were sequellae of an inner third clavicle fracture and an arterial hypertension; although the patient was given a minimal dose of calcium heparinate.
Subject(s)
Catheterization/adverse effects , Hemothorax/etiology , Subclavian Vein , Adult , Hemothorax/prevention & control , Humans , Male , RiskSubject(s)
Corneal Diseases/surgery , Eye Neoplasms/surgery , Fibroma/surgery , Adolescent , Cornea/surgery , Humans , MaleABSTRACT
Many drugs used during resuscitations, are mighty oxidants able to induce intravascular hemolysis in patient with G6PD deficiency. Reversible and not immediately recurrent, hemolysis should be avoided by systematic (prevention) using specific blood tests. This paper was suggested by the case of a 37-year-old (Malgache) patient, with no history sustaining an acute hemolysis with kidney failure, appearing after intra-operative phenothiazine injection.