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1.
J Fr Ophtalmol ; 46(7): 697-705, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37573231

RESUMEN

There is growing interest nowadays for artificial intelligence (AI) in all medical fields. Beyond the direct medical application of AI to medical data, generative AI such as "pre-trained transformer" (GPT) could significantly change the ophthalmology landscape, opening up new avenues for enhancing precision, productivity, and patient outcomes. At present, ChatGPT-4 has been investigated in various ways in ophthalmology for research, medical education, and support for clinical decisions purposes. This article intends to demonstrate the application of ChatGPT-4 within the field of ophthalmology by employing a 'mise en abime' approach. While we explore its potential to enhance the future of ophthalmology care, we will also carefully outline its current limitations and potential risks.


Asunto(s)
Inteligencia Artificial , Oftalmología , Humanos
2.
J Laryngol Otol ; 133(5): 390-393, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30947760

RESUMEN

BACKGROUND: It is hypothesised that patients with muscle tension dysphonia have a high prevalence of dysphagia in comparison to normative values reported in the literature. METHODS: This prospective study included 44 subjects diagnosed with muscle tension dysphonia, based on symptoms and laryngoscopic findings, and 25 control subjects with no history of dysphonia and normal laryngeal examination findings. Demographic data included age, gender and smoking history. The aetiology of muscle tension dysphonia was classified as primary or secondary. Evaluation involved the Eating Assessment Tool ('EAT-10') questionnaire. RESULTS: Patients' mean age was 45.93 ± 14.95 years, with a female to male ratio of 1.2:1. Fourteen patients had primary muscle tension dysphonia, while 30 had secondary muscle tension dysphonia. Among patients with secondary muscle tension dysphonia, Reinke's oedema was the most common aetiology. There was a significant difference in the prevalence of dysphagia between the study group and the control group (40.9 per cent vs 8 per cent respectively, p < 0.05). CONCLUSION: This study demonstrates a higher prevalence of dysphagia in patients with the presenting symptom of dysphonia and diagnosed with muscle tension dysphonia in comparison to subjects with no dysphonia.

3.
Opt Lett ; 37(17): 3672-4, 2012 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-22940986

RESUMEN

Attosecond science is enabled by the ability to convert femtosecond near-infrared laser light into coherent harmonics in the extreme ultraviolet spectral range. While attosecond sources have been utilized in experiments that have not demanded high intensities, substantially higher photon flux would provide a natural link to the next significant experimental breakthrough. Numerical simulations of dual-gas high harmonic generation indicate that the output in the cutoff spectral region can be selectively enhanced without disturbing the single-atom gating mechanism. Here, we summarize the results of these simulations and present first experimental findings to support these predictions.

4.
Biotechnol Bioeng ; 57(2): 220-7, 1998 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-10099197

RESUMEN

The effect of nonionic surfactants on the polycyclic aromatic hydrocarbon (PAH) oxidation rates by the extracellular ligninolytic enzyme system of the white-rot fungus Bjerkandera sp. strain BOS55 was investigated. Various surfactants increased the rate of anthracene, pyrene, and benzo[a]pyrene oxidation by two to fivefold. The stimulating effect of surfactants was found to be solely due to the increased bioavailability of PAH, indicating that the oxidation of PAH by the extracellular ligninolytic enzymes is limited by low compound bioavailability. The surfactants were shown to improve PAH dissolution rates by increasing their aqueous solubility and by decreasing the PAH precipitate particle size. The surfactant Tween 80 was mineralized by Bjerkandera sp. strain BOS55; as a result both the PAH solubilizing activity of Tween 80 and its stimulatory effect on anthracene and pyrene oxidation rates were lost within 24 h after addition to 6-day-old cultures. It was observed that the surfactant dispersed anthracene precipitates recrystallized into larger particles after Tween 80 was metabolized. However, benzo[a]pyrene precipitates remained dispersed, accounting for a prolonged enhancement of the benzo[a]pyrene oxidation rates. Because the endogenous production of H2O2 is also known to be rate limiting for PAH oxidation, the combined effect of adding surfactants and glucose oxidase was studied. The combined treatment resulted in anthracene and benzo[a]pyrene oxidation rates as high as 1450 and 450 mg L-1 d-1, respectively, by the extracellular fluid of 6-day-old fungal cultures.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos/metabolismo , Polyporales/metabolismo , Biodegradación Ambiental , Disponibilidad Biológica , Biotecnología , Peróxido de Hidrógeno/metabolismo , Cinética , Oxidación-Reducción , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Solubilidad , Tensoactivos
5.
Circulation ; 94(9 Suppl): II294-7, 1996 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-8901763

RESUMEN

BACKGROUND: The effect of pretransplant sensitization on outcome after cardiac transplant has been controversial. Sensitization, defined as a positive panel-reactive antibody (PRA) screen in patients awaiting transplant, represents circulating antibodies to a random panel of donor lymphocytes (usually T lymphocytes). The significance of pretransplant circulating antibodies to B lymphocytes has not been reported, and many centers disregard its use. METHODS AND RESULTS: We retrospectively reviewed the pretransplant PRA screens for 311 patients who underwent cardiac transplant at our institution. The PRA screen was performed by use of the lymphocytotoxic technique treated with dithiothreitol to remove IgM autoantibodies. Patients with PRA > or = 11% against T or B lymphocytes had significantly lower 3-year survival (T lymphocytes, 39%; B lymphocytes, 56%) than those patients with PRA = 0% and PRA = 1% to 10% (T lymphocytes, 76% and 78%; B lymphocytes, 78% and 74%, respectively) (P < .001). For this high-risk group, the rejection episode tended to occur earlier than in those patients with PRA = 0% and PRA = 1% to 10% (T lymphocytes, 2.3 versus 4.0 and 3.8 months; B lymphocytes, 2.1 versus 4.1 and 3.4 months, respectively), and there were more clinically severe rejections that required OKT3 therapy. CONCLUSIONS: Cardiac transplant patients with pretransplant T- and/or B-lymphocyte PRA > or = 11% despite negative donor-specific crossmatch at the time of transplant appear to have earlier and more severe rejection with significantly lower survival after transplant surgery. Modification of immunosuppression in these high-risk patients may be warranted.


Asunto(s)
Anticuerpos/sangre , Linfocitos B/inmunología , Trasplante de Corazón , Linfocitos T/inmunología , Adulto , Anciano , Femenino , Rechazo de Injerto , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
6.
J Calif Dent Assoc ; 23(11): 61-6, 68, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9052003

RESUMEN

Organ transplantation is a viable treatment for individuals whose quality of life is significantly impaired. There has been a dramatic increase in the number of whole organ transplants being performed over the past few years; and although somewhat limited by donor availability, these numbers have continued to increase as success rates improve and more medical centers perform them. The number of solid organ transplants performed throughout the world has grown from 35,628 (1980-1990) to 285,561 (1989-1991). The number of patients on the waiting list for organs has increased by 59.4 percent from 1988 to 1993. As this patient population grows, the community-based dental practitioner will be faced with a special set of concerns. Understanding the diverse precautions for treatment of pre- and post-organ transplant patients will help the practitioner adequately treat the dental needs of this patients population.


Asunto(s)
Atención Dental para Enfermos Crónicos , Inmunosupresores/efectos adversos , Enfermedades de la Boca/etiología , Trasplante de Órganos/efectos adversos , Humanos , Enfermedades de la Boca/terapia , Planificación de Atención al Paciente , Premedicación , Acondicionamiento Pretrasplante/efectos adversos
7.
Eur J Biochem ; 229(3): 658-68, 1995 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-7758460

RESUMEN

The oxidized Fe4S4 ferredoxin from the hyperthermophilic bacterium Thermotoga maritima has been investigated by one- and two-dimensional NMR in order to characterize its hyperfine-shifted resonances originating from the cysteinyl cluster ligands and to assign its resonances in the diamagnetic shift range. The chemical shift and relaxation time pattern of the hyperfine-shifted signals is very similar to other oxidized Fe4S4 ferredoxins. A tentative sequence-specific assignment of these resonances according to a general pattern of chemical shift of cysteine protons versus sequence position of cluster ligand is presented. Furthermore, sequence-specific assignments for 85% of the amino acid residues that were obtained without any guidance by known X-ray structures of ferredoxins are given. They reveal the formation of at least two elements of secondary structure by the polypeptide chain of T. maritima ferredoxin: an alpha-helix comprising residues C43-D49 and a double-stranded antiparallel beta-sheet consisting of the N- and C-terminal parts of the protein. This folding pattern is very similar to that of the crystallographically characterized ferredoxin from the mesophile Desulfovibrio gigas [Kissinger, C.R., Sieker, L.C., Adman E.T. & Jensen, L.H. (1991) J. Mol. Biol. 219, 693-715] and therefore suggesting different mechanisms of stabilization for T. maritima ferredoxin and the ferredoxin from the hyperthermophilic archaeon Pyrococcus furiosus that was recently investigated by NMR [Teng, Q., Zhou, Z.H., Smith, E.T., Busse, S. C., Howard, J.B., Adams M.W.W. & La Mar, G.N. (1994) Biochemistry 33, 6316-6326].


Asunto(s)
Ferredoxinas/química , Bacterias Anaerobias Gramnegativas/química , Proteínas Hierro-Azufre/química , Espectroscopía de Resonancia Magnética , Estructura Secundaria de Proteína , Secuencia de Aminoácidos , Cisteína/química , Datos de Secuencia Molecular , Oxidación-Reducción , Pliegue de Proteína , Alineación de Secuencia
8.
Arch Mal Coeur Vaiss ; 87(3): 409-13, 1994 Mar.
Artículo en Francés | MEDLINE | ID: mdl-7832631

RESUMEN

A cardiac tumour of the interventricular septum was detected in a young woman presenting with an ejectional systolic murmur. Surgical ablation was carried out before a precise diagnosis was made. Histopathological analysis of the surgical specimen confirmed a hydatid cyst. The main complication was complete atrioventricular block. This case underlines the difficulty of making the diagnosis of intracardiac hydatid disease in a non-specific context, because of the long period of clinical latency, despite the considerable aid of echocardiography and other medical imaging techniques (CT scan and magnetic resonance imaging.


Asunto(s)
Equinococosis/complicaciones , Cardiopatías/etiología , Tabiques Cardíacos , Adulto , Equinococosis/cirugía , Ecocardiografía Doppler en Color , Ecocardiografía Transesofágica , Femenino , Bloqueo Cardíaco/etiología , Cardiopatías/diagnóstico , Cardiopatías/cirugía , Humanos
9.
Eur Heart J ; 9 Suppl E: 77-82, 1988 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3402484

RESUMEN

To appreciate the incidence, the promoting factors and the consequences of mitral calcification in aortic stenosis (AS), the data from 675 patients operated on for AS were reviewed. Mitral calcification was revealed by fluoroscopy, echocardiography and/or surgery. Mitral annular calcification (MAC) was observed in 169 patients (25%). In patients with MAC, females were more frequent (42.3 vs. 17.9%, P less than 0.0001), age was greater (64 vs. 58 years, P less than 10(-7)), AS was more severe (0.6 vs. 0.7 cm2, P less than 0.002), and LV walls were thicker (interventricular septum 13.5 vs. 12 mm, P less than 0.0003 posterior wall 12.8 vs. 11.9 mm, P less than 0.004). First-degree AV block was more frequent in patients with MAC but did not lead to more frequent pacemaker implantation. Mitral anterior leaflet calcification was noted in 215 patients (31.8%). When massive, it created mitral stenosis which, in one case, required later mitral replacement. Five- and ten-year actuarial survival rates were not different in patients with or without mitral calcification. We conclude that mitral calcification is frequent in AS. Promoting factors for MAC are age, severity of AS, and female gender.


Asunto(s)
Estenosis de la Válvula Aórtica/patología , Calcinosis/patología , Válvula Mitral/patología , Adulto , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Ecocardiografía , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Radiografía , Estudios Retrospectivos
10.
Eur Heart J ; 8(5): 457-63, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3609040

RESUMEN

Between 1968 and 1984, 78 patients (mean age 43, range 14 to 65 years) underwent combined aortic, mitral and tricuspid surgery (22 triple valve replacements, 56 aortic valve replacements with tricuspid conservative surgery and mitral valve replacement (N = 48), or commissuroplasty (N = 8). Pre-operative consequences of valvular disease (mainly mixed valve disease) were severe as assessed by functional class (72 pts in III or IV NYHA), cardiomegaly (CTR: 62 +/- 6%), increase of mean pulmonary arterial and wedge pressures (respectively 30 +/- 12 and 19 +/- 6 mmHg) decrease in cardiac index (2.1 +/- 0.5 l min-1 m-2), LV dilatation (LV end diastolic volume: 184 +/- 86 ml m-2) and impairment of LV systolic function (LV ejection fraction: 50 +/- 12%). Operative mortality rate was 11.5%. The 69 survivors were all followed up, for a mean of 56 months (2 to 207). 16 late deaths occurred. Actuarial survival rate at 10 years was 58.4%, and greatly influenced by pre-operative NYHA class. Linearized rates of thromboembolic events, valve thrombosis and haemorrhage were respectively 6.4, 1.5 and 1.2% pt-1 yr-1. Those of infective endocarditis, periprosthetic leak, reoperation and valve failure were 0.6, 3.3 and 4.9% pt-1 yr-1 respectively. At 9 years, 42% of the patients were in NYHA class I or II and free from complications.


Asunto(s)
Válvula Aórtica/cirugía , Enfermedades de las Válvulas Cardíacas/cirugía , Prótesis Valvulares Cardíacas , Válvula Mitral/cirugía , Válvula Tricúspide/cirugía , Adolescente , Adulto , Anciano , Bioprótesis , Terapia Combinada , Femenino , Estudios de Seguimiento , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/mortalidad , Falla de Prótesis , Reoperación , Tromboembolia/mortalidad
11.
J Mol Cell Cardiol ; 17(4): 361-9, 1985 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2991538

RESUMEN

Isoproterenol-induced myocardial necrosis was examined in male mice with alloxan-induced and genetically transmitted diabetes. Ten days after alloxan treatment, mice exhibited an elevation in blood glucose concentrations, weight loss, polyuria and decreased heart rates (510 +/- 15 v. 675 +/- 11 beats/min) compared with matched control mice. Similarly, genetically diabetic mice exhibited lower heart rates than the corresponding age-matched controls (383 +/- 30 v. 603 +/- 30 beats/min). In comparison to matched controls, both groups of diabetic mice had a significant decrease in the severity of the cardiac necrosis which was induced by the administration of isoproterenol. The reduction in isoproterenol-induced cardiac lesions was similar in mice with chemically induced diabetics and mice with genetically transmitted diabetes. Biochemical studies of ventricular slices revealed no change in basal cAMP levels and no differences in isoproterenol-induced changes in cAMP levels in mouse hearts from both models of diabetes. Insulin treatment corrected the chemically induced diabetic state and restored the cardiotoxic potential of isoproterenol.


Asunto(s)
Cardiomiopatías/etiología , Diabetes Mellitus Experimental/complicaciones , Isoproterenol/toxicidad , Animales , Cardiomiopatías/patología , AMP Cíclico/metabolismo , Diabetes Mellitus Experimental/metabolismo , Corazón/efectos de los fármacos , Insulina/farmacología , Masculino , Ratones , Miocardio/metabolismo , Necrosis
12.
Agents Actions ; 12(4): 431-7, 1982 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6184975

RESUMEN

Comparisons were made of the ability of doxorubicin, daunorubicin, rubidazone and aclacinomycin A to release histamine from rat peritoneal mast cells. Preliminary in vitro experiments indicated that doxorubicin (10(-6) to 2.5 X 10(-4) M), in contrast to compound 48/80 and the calcium ionophore A23187, did not produce significant release under any condition tested when purified or unpurified rat mast cells were used. In in vitro experiments, released histamine was measured in the cell-free supernatant of peritoneal fluid of rats after intraperitoneal injection of the agents. The time course of doxorubicin-induced histamine release from the peritoneum was rapid, with maximal release occurring within 4 to 6 min. Dose-response curves of the 4 agents over the range 10(-5) to 3.3 X 10(-3) M revealed that all caused histamine release, with 10(-3) M concentrations of each causing maximal release of comparable magnitude to that produced by 9.5 X 10(-6) M A23187. Treated mast cells recovered from the peritoneal cavity showed degranulation and vacuolization when examined by electron microscopy. Increased vascular permeability by the Evans-blue test was also noted with all 4 agents, and zones were of comparable size after injection of the highest concentration of each agent. The results indicate that in vivo, doxorubicin, daunorubicin, rubidazone and aclacinomycin A cause a rapid release of histamine from rat mast cells and an increase in vascular permeability in rat sin. There also appeared to be a reasonable correlation between the blueing reaction and histamine release in the peritoneal cavity in that the doses that did not cause skin blueing also failed to cause histamine release. The lack of histamine release by doxorubicin from mast cell preparations in vitro suggests that alterations to the doxorubicin molecule or the presence of other critical substances may be necessary for this activity to commence.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Liberación de Histamina/efectos de los fármacos , Mastocitos/efectos de los fármacos , Aclarubicina , Animales , Daunorrubicina/análogos & derivados , Daunorrubicina/farmacología , Doxorrubicina/farmacología , Masculino , Naftacenos/farmacología , Ratas , Ratas Endogámicas , Coloración y Etiquetado
13.
Res Commun Chem Pathol Pharmacol ; 33(3): 509-23, 1981 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7036302

RESUMEN

Blood glucose concentrations were markedly elevated in CD-1 mice 48 hr after iv administration of alloxan (75 mg/kg). Treatment with three doses of ICRF-187 (96 to 345 mg/kg) given 60 min before and 4 and 8 hr after alloxan significantly attenuated the increase in blood glucose. Pretreatment with dimethyl sulfoxide (DMSO), a known free radical scavenger, at doses of 3.5 to 7.3 g/kg also protected against the alloxan diabetogenic action. When the lowest doses of ICRF-187 (96 mg/kg) and DMSO (3.5 g/kg) were combined, alloxan exerted no hyperglycemic effect. The protective effects of ICRF-187 and DMSO were confirmed morphologically. In alloxan-treated animals, beta cell granules were absent. In contrast, the degree of granulation showed only a mild to moderate reduction in those alloxan-treated animals given ICRF-187 alone, DMSO alone, or the combination of ICRF-187 and DMSO. These results suggest that ICRF-187 may alter the mechanism of free radical generation thought to be responsible for the production of alloxan diabetes.


Asunto(s)
Aloxano/antagonistas & inhibidores , Diabetes Mellitus Experimental/prevención & control , Piperazinas/uso terapéutico , Razoxano/uso terapéutico , Animales , Glucemia/análisis , Quelantes/farmacología , Relación Dosis-Respuesta a Droga , Radicales Libres , Islotes Pancreáticos/patología , Masculino , Ratones , Ratones Endogámicos , Razoxano/farmacología
14.
Z Parasitenkd ; 47(2): 79-89, 1975 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-171875

RESUMEN

Experimental infections of the hamster liver were carried out with five strains from patients with clinical amoebiasis and ten strains from asymptomatic carriers. Inocula of comparatively small size (12000-36000 amoebae) were injected under the liver capsule. 1. The virulence of the patient strains varied from 21-96% (see article) and declined sharply within 7-15 weeks after elimination of the associated bacterial flora. The virulence of the carrier strains varied from 0-100%, probably fluctuating with changes in the concomitant bacterial flora (Table 1). 2. The interrelation between size of inoculum, period of bacteria-free growth, and virulence was demonstrated with a Crithidia-associated patient strains (Table 2). 3. A patient strain showed a faster decrease of virulence during axenic than in Crithidia-associated cultivation (Table 3). 4. Two successive passages through hamster liver resulted in a marked increase of virulence of two bacteria-free strains, lasting for several months (Table 4). 5. A significant enhancement of virulence of Crithidia-associated and axenic amoebae by reassociation with a mixed bacterial flora during two weeks, followed by elimination of the bacteria, was demonstrated with two strains. The restored virulence was lost again within a few weeks (Table 5). 6. The virulence of an attenuated patient strain did not become manifest by adding large numbers of dead amoebae to the inoculum (Table 6). 7. The pathology of the different lesions caused in the hamster liver by the amoebae is described, including one of a granulomatous type, frequently found after inoculation with bacteria-free amoebae. 8. In an attempt to explain the occurrence of strains differing in pathogenicity an hypothesis is put forward based on the idea of selection of virulence and avirulent amoebae.


Asunto(s)
Amebiasis/parasitología , Portador Sano/parasitología , Entamoeba histolytica/patogenicidad , Entamebiasis/parasitología , Parasitosis Hepáticas/parasitología , Animales , Bacterias/crecimiento & desarrollo , Modelos Animales de Enfermedad , Entamoeba histolytica/crecimiento & desarrollo , Entamebiasis/patología , Eucariontes/crecimiento & desarrollo , Humanos , Hígado/patología , Parasitosis Hepáticas/patología , Virulencia
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