Biomedical subjects
Publications and source records attributed to L Guerra.
The clinical results of 772 biointegrated hydroxylapatite-coated titanium dental implants are discussed. The longest radiographic follow-up was done at 5 years, with a success rate of greater than 95%. Supporting animal research with other titanium implants is also provided.
Fifty-six S. aureus episodes of catheter exit-site tunnel infections were diagnosed in 40 out of 163 patients treated by CAPD for 30 +/- 22 months, with standard double-cuff Tenckhoff catheters. The rate of infection was 1 episode every 29 patient/months. Local care and antibiotic therapy were effective in 52% of the cases. Whereas in 29 episodes in which the medical therapy failed to eradicate the infection the entire area of granulation tissue and cellulitis was excised then the outer dacron cuff was shaved from the silicone catheter. With this treatment 13 episodes (48%) were cured while, in the remaining 14 patients the catheters were removed because of peritonitis in 10; and for failure to eradicate the infection in 4.
The Authors analyze their experience of 25 thumb reimplantations and revascularizations within 5 years. The importance of the first finger in the functional hand economy as well as the ratio between reimplantation take rate and degree of functional recovery with regard to the type of trauma, technique used, and possible and incidental complications are underlined. The venous autologous grafts are of great importance in this microsurgical area and they are more and more applied. In most cases, indeed, intimal lesions are more extended than their macroscopic appearance and the tract of damaged vessels is always wider than assessed. The graft interposition solves the problem with the further advantage to preserve the maximal bone length and to avoid especially contaminated areas. The results achieved confirm these statements and the Authors conclude for the absolute need of venous grafts in thumb reimplantations, especially after amputation from avulsion or crush traumas, even though a greater skill is necessary in using this technique.
The free latissimus dorsi flap has been used to repair 10 complex losses of substance of the lower extremity. The results have shown the great reconstructive potentialities of the microvascular transfer of this muscle, considered by the authors the most versatile of the myocutaneous flaps. Among the advantages there are the extended surface, its thickness, its pedicle with adequate length and diameter as well as the absence of functional involvement, especially by preserving the upper branch of the thoracodorsal nerve. The indications, however, are limited due to a significant rate of complications which prevent its extended use.
The persistence of cartilage in the adult newt (Notophthalmus viridescens) forelimb skeletal regenerate has recently been reported by Libbon et al. It is particularly evident in the carpal group, which remains cartilaginous for at least 9 months while all other regrown skeletal parts are either ossified or ossifying. The present investigation was undertaken to determine whether delayed ossification in the adult regenerate recapitulates a pattern evident during the development of the forelimb of the red eft (N. viridenscens' immature terrestrial phase). Right upper limbs of 20 efts were examined at low magnification to establish carpal composition and organization. Among five efts of the smallest size (26.54 plus or minus 2.20 mm snout-to-vent length), and displaying bright orange dorsal skin coloration, all carpal rudiments were cartilaginous. Eleven efts, intermediate in length (33.88 plus or minus 0.81 mm), displaying orange-green coloration, all carpals had ossified. These observations demonstrate that during adult newt forelimb regeneration, the failure of the carpal elements to begin ossification in synchrony with other regrown skeletal parts duplicates a similar schedule of delayed mesopodial ossification which is evident during the development of the red eft's forelimb.
The frequency of thimerosal sensitization was determined in 5 groups of subjects: military recruits; healthy subjects; patients with asthma or rhinitis undergoing hyposensitizing therapy with thimerosal-preserved antigenic extracts; patients with allergic contact dermatitis; patients with allergic contact conjunctivitis. Our patients with allergic contact dermatitis have a higher incidence of positive patch tests to thimerosal than healthy subjects. The source of thimerosal sensitization in this group remains obscure, their history of exposure to this or to other mercury derivatives being comparable to that of the healthy population. Patients with allergic contact conjunctivitis and patients receiving immunotherapy for asthma or rhinitis present a significantly higher frequency of thimerosal sensitization than the other groups, indicating that ophthalmic solutions and thimerosal-preserved allergen extracts are an important source of thimerosal sensitization. The clinical relevance of thimerosal sensitization was definitively established only in patients with allergic contact conjunctivitis, even though patients receiving immunotherapy frequently presented local reactions at the site of allergen inoculation.
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The use of a differential quantitative blood culture technique (Isolator) to diagnose intravascular-device-related bacteremia (IDRB) was studied prospectively. During septic episodes in 44 patients, blood was obtained simultaneously through the suspected infected device and from a peripheral venipuncture. The blood samples were processed by the Isolator technique, which enables easy quantification of microorganisms. The cannula was removed, and its tip was cultured semiquantitatively. Of the 52 cannulas studied, 15 were the cause of IDRB, but only 7 of these showed a significantly higher bacterial count in blood obtained through the device compared with peripheral blood. The bacterial count was higher in blood drawn through the device than in peripheral blood in four of six cases that did not fulfill the definition of IDRB. Some blood cultures obtained through the device were positive despite negative cultures of peripheral blood and cannula tips (six cannulas). Quantitative blood cultures were not useful in diagnosing IDRB in this study.
Sulfhydryl (SH) reactive reagents, such as eosin derivatives, have been found to be useful in labeling water pathways in red cells. In the present study we used an impermeable SH-reagent, a fluorescent maleimide analogue EMA (eosin-5'-maleimide), in order to identify proteins involved in water permeability response to antidiuretic hormone (ADH). We observed that: 1) EMA (1 mM) mucosal pretreatment did not modify either the basal water flux or the subsequent ADH-induced hydrosmotic response; 2) EMA added to the mucosal bath at the maximum response to ADH, significantly decreased net water flux by about 40%; similar results were obtained when 10(-5) M forskolin was used as a hydrosmotic agent. These results suggest that the inhibitory effect of EMA occurs at a post cAMP step, possibly at the level of the sulfhydryl groups of the water channels themselves. Fluorescence distribution in SDS-PAGE of Triton X-100 extracted proteins from bladder labeled with EMA in both control conditions and under ADH stimulation allowed us to identify apical membrane proteins, labeled during ADH stimulation and not labeled in water impermeable controls. Of particular importance are four proteins of 52, 32-35, 26, 17, kDa. These polypeptides are probably involved in ADH-stimulated water transport and may be components of the water channels.
To evaluate the possible role of oral phosphatidylcholine administration in improving peritoneal ultrafiltration sixteen continuous ambulatory peritoneal dialysis (CAPD) patients with a reduced ultrafiltration rate (less than 500 mL/4 h after a standard 3.86% glucose exchange) were studied. Three patients spontaneously stopped phosphatidylcholine due to gastric side effects. Three out of the remaining 13 patients showed a mild increase of standard ultrafiltration, which was not followed by any increase in daily dialysate output. No differences in glucose, sodium, potassium, urea and creatinine equilibration curves were seen. In conclusion, in our series oral phosphatidylcholine is not free of side effects, and its efficacy in improving ultrafiltration is scanty, with no clinical relevance in increasing daily ultrafiltration.
To evaluate acceptability, safety, and efficacy of a Y set with two short branches (TAS) filled with electrolytic chloroxidizer solution during the dwell time, 60 patients were randomly allocated to be treated with the traditional Y set (TCS) or with the TAS. Twenty-three were new patients whereas the remaining 37 were patients already on continuous ambulatory peritoneal dialysis (CAPD) with the TCS. The follow-up was 416.5 months in the control group and 387.4 months in the test group. During the study period there were 6 peritonitis episodes in each group with an incidence of 1 episode every 69.4 patient-months in the control group and 1 episode every 64.6 patient-months in the test group. Twenty-four patients (80%) in the control group and 27 (90%) in the test group were free from peritonitis. The probability to remain free from peritonitis was respectively 87% and 83% in the test group and in control group after 12 months, 70% and 78% after 21 months. Seventy-nine percent of the patients who used both systems preferred the TAS for better handling, lower encumbrance, and major safety. One patient preferred the TCS, three patients did not find any differences between the two devices.
The classification, pathogenesis, clinical features and treatment of pemphigus are examined with emphasis' on the histopathological similarities of the elementary intraepithelial lesion and the histotopographical differences at epithelial level that differentiate the various types of pemphigus. In a detailed review of the pathogenesis of the condition, the circumstances propitious for the onset of pemphigus are identified as an HLA phenotype and the autoantigenic denaturation of the glycocalyx. The condition is described as vesicolobullous and is differentiated from similar bullous and non-bullous dermatoses. The most significant pictures of oral pemphigus are specified as are the basic elements of general and local treatment.
The Authors give a detailed analysis of the potential virulence factors and possible pathogenic processes associated with candida. They qualify the interactions between local, general, natural and acquired defences, setting out the possible deficiency involved in the emergence of secondary candidiasis. They make a classificatory revision of forms of candidiasis on the basis of topographic, anatomo-pathologic criteria and of the course of the disease. They investigate the most significant aspects of the situations described especially in oral localization. An evaluation is made of chronic mucocutaneous candidiasis as a pathological affection in itself and in its correlation with H.I.V. infection.
Involutional depression is often the first symptom of a psycho-organic syndrome or dementia and may not present overt symptoms itself; these depressive states have been variously classified by different schools in various countries. The hypothesis of catecholamine and indolamine in the aetiopathogenic agent is oversimplistic and the theory that abnormal receptor hypersensitivity is the cause of the condition is more convincing. On the basis of this hypothesis numerous studies have been conducted into the efficacy of various antidepressants in the treatment of this hypersensitivity. Involutional depressions are more common among women and are found in about 10% of 60-65 year olds. This report claims that combined viloxazine-piracetam is the most appropriate treatment for involutional depression. This approach (200 mg oral viloxazine and 9 g oral piracetam a day) was adopted for 3 months in 33 out patients about 64 years old who were subsequently put on maintenance doses (100 mg viloxazine, 3 g piracetam a day). The various Hamilton scale parameters were assessed as were reaction times to auditory and visual simple stimuli. Result sat the start and end of treatment were then compared. About three quarters of the patients showed improvement in both depression and psycho-organic syndrome symptoms, while total remission or lasting improvement in both pathologies was obtained in about 50%.
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Explore the source record for details and available documents.