Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Hum Reprod ; 29(1): 83-9, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24218401

RESUMEN

STUDY QUESTION: Is perceived social support from partner, family, and friends associated with increased infertility-related stress? SUMMARY ANSWER: While men's perceived support did not seem to influence their partners' stress, women's perceptions of spousal and familial support can affect the way men deal with the challenge of infertility. WHAT IS KNOWN ALREADY: Previous studies showed that low levels of social support are associated with poor psychosocial adjustment and treatment termination in women and men. Studies examining the impact of social support using the couple as unit of analysis are lacking. STUDY DESIGN, SIZE, DURATION: A cross-sectional sample of 613 Portuguese patients participated in the research, online over a 3-month period, and in a public fertility clinic over 11 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: The final sample comprised 213 married or cohabiting couples (191 from the fertility clinic) who were actively attempting to have a child, were seeking infertility treatment and had not undergone previous preimplantation genetic diagnosis. Perceived social support was assessed through the Multidimensional Scale of Perceived Social Support and infertility-related stress was assessed with the fertility problem inventory. Hypotheses were tested by applying the actor-partner interdependence model using structural equation modeling. MAIN RESULTS AND THE ROLE OF CHANCE: Couples had been living together for an average (±SD) of 6 ± 3.5 years, and attempting a pregnancy for 3.8 ± 2.6 years. Nearly half of the couples had undergone infertility treatment (41.3%). Infertility stress was found to be associated with low family support for women (ß = -0.27, P = .003), and low partner support for both men (ß = -0.29, P = .001) and women (ß = -0.45, P = .006). Both women and men's perceived friend support were not significantly related to male or female infertility stress. Men infertility stress was also associated with their partners low levels of partner (ß = -0.24, P = .049) and family support (ß = -0.23, P < .001). No significant partner effects were observed for women. Despite being related to actor effects alone (female partner and family support), the explained variance of the model in women's fertility stress was greater (R(2) = 21%) than that (R(2) = 15.6%) for the combined actor and partner effects in men's fertility stress (male partner support, female partner and family support). LIMITATIONS, REASONS FOR CAUTION: The study data are cross-sectional and the generalizability of results is limited by self-selection. The characteristics of non-participants in both the clinical and online samples were not available, the perception of infertility-specific supportive behaviors was not assessed and differential analyses according to infertility diagnosis were not included in this study. WIDER IMPLICATIONS OF THE FINDINGS: Our data underline the importance of partner support in alleviating the burden of infertility. Men may experience infertility indirectly through the impact that it has on their partners. Our findings reinforce the need to involve the male partner throughout the whole treatment process and for couple-based interventions when providing infertility counseling. Further prospective research should be aimed at investigating the male experience of infertility. STUDY FUNDING/COMPETING INTEREST: This research was supported by a PhD scholarship from the Portuguese Foundation for Science and Technology granted to M.M. (FCT, SFRH/BD/44232/2008). The authors have no conflicts of interest to declare.


Asunto(s)
Infertilidad Femenina/psicología , Infertilidad Masculina/psicología , Apoyo Social , Estudios Transversales , Composición Familiar , Femenino , Humanos , Masculino , Percepción , Parejas Sexuales , Estrés Psicológico
2.
Mater Sci Eng C Mater Biol Appl ; 109: 110492, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32228989

RESUMEN

Laser texturing is a technique that has been increasingly explored for the surface modification of several materials on different applications. Laser texturing can be combined with conventional coating techniques to functionalize surfaces with bioactive properties, stimulating cell differentiation and adhesion. This study focuses on the cell adhesion of laser-sintered coatings of hydroxyapatite (HAp) and 45S5 bioactive glass (45S5 BG) on zirconia textured surfaces using MC3T3-E1 cells. For this purpose, zirconia surfaces were micro-textured via laser and then coated with HAp and 45S5 BG glass via dip coating. Afterwards, the bioactive coatings were laser sintered, and a reference group of samples was conventionally sintering. The cell adhesion characterisation was achieved by cell viability performing live/dead analysis using fluorescence stains and by SEM observations for a qualitative analysis of cell adhesion. The in vitro results showed that a squared textured pattern with 100µm width grooves functionalized with a bioactive coating presented an increase of 90% of cell viability compared to flat surfaces after 48h of incubation. The functionalized laser sintered coatings do not present significant differences in cell viability when compared to conventionally sintered coatings. Therefore, the results reveal that laser sintering of HAp and 45S5 BG coatings is a fast and attractive coating technique.


Asunto(s)
Osteoblastos/efectos de los fármacos , Circonio/química , Animales , Adhesión Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Durapatita/química , Masculino , Ratones , Microscopía Electrónica de Rastreo , Ratas , Ratas Sprague-Dawley
3.
J Mech Behav Biomed Mater ; 102: 103516, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31877521

RESUMEN

The present study aims at developing a computational framework with experimental validation to determine the mechanical properties of zirconia foams for bone tissue engineering. A micro-CT based finite element model that allows characterizing the mechanical property of such cellular structures is developed. Micro-CT images are filtered to vanish noises and smooth boundaries before constructing 3D zirconia foams using an adaptive Body-Centered Cubic background lattice. In addition to micro-CT images, the local material property at the scaffold struts is measured using a micro-indentation test, which shows a considerable difference with that of common zirconia owing to the manufacturing process. The computational model also takes the plastic deformation of material into account employing the Voce law, a nonlinear isotropic hardening law, as well as Von-mises yield criterion. Zirconia foams with different pore sizes are manufactured using the replica method and their mechanical properties determined experimentally. Such experimental outcomes are to validate and demonstrate the capability of the developed model, which can be used for pre-operational evaluations and preclinical tests of zirconia scaffolds. The stress magnitude and distribution within the scaffold as well as plastic strains and flow stress of the zirconia scaffold are computed and analysed. Using the proposed approach, a deep insight into the association of macroscopic behaviour of the scaffold to microscopic features, e.g. strut waviness, Plateau border, thickness variation of cells, irregularity, microstructural variability, imperfections and strut's material property associated with to the manufacturing procedure, can be gained.


Asunto(s)
Huesos , Ingeniería de Tejidos , Análisis de Elementos Finitos , Estrés Mecánico , Andamios del Tejido , Microtomografía por Rayos X , Circonio
4.
J Mech Behav Biomed Mater ; 94: 110-125, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30884280

RESUMEN

Zirconia implants are becoming a preference choice for different applications such as knee, dental, among others. In order to improve osseointegration, implant's surfaces are usually coated with bioactive materials like hydroxyapatite (HAp) and beta-tricalcium phosphate (ß-TCP) that are very similar to the calcium phosphates found in bones. However, due to the implantation process, these coatings can be detached from the zirconia surface, leading to implant premature failure. In this work, a new component materials design aiming to avoid this coating detachment problem is proposed. It is based on the use of a bioactive zirconia-calcium phosphate composite outer layer onto the zirconia bulk, where the zirconia bulk provides mechanical strength and the outer layer provides biological performance. In order to assess the potential of this new materials design, two types of bioactive zirconia outer composite layers (zirconia reinforced by 10 vol% of HAp and by 10 vol% of ß-TCP) were produced by press and sinter process and the gradated samples were fully characterized concerning materials, mechanical resistance, fatigue resistance, and biological performance, as measured by different approaches. Results showed that the novel component materials design and the manufacturing process proposed for producing the bioactive zirconia samples with outer composite layers on zirconia bulk substrates are a promising solution for implants, with improved biological performance without substantially compromising their overall mechanical and fatigue properties.


Asunto(s)
Prótesis e Implantes , Circonio/química , Fosfatos de Calcio/química , Durapatita/química , Módulo de Elasticidad , Dureza , Propiedades de Superficie , Temperatura , Humectabilidad
5.
J Mech Behav Biomed Mater ; 96: 219-226, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31055212

RESUMEN

The development of dental restorative materials that mimic tooth-like properties provided by graded structures, aesthetics and properties such as strength, damping capacity and the ability for a continuous remodeling according to the biomechanical solicitation is a great challenge. In this work, damping capacity and dynamic Young's modulus of Y-TZP/porcelain composites for all-ceramic dental restorations were studied. These mechanical properties were assessed by dynamic mechanical analyses (DMA) at frequencies of 1, 5 and 10 Hz, over a temperature ranging from 0 to 60 °C, simulating extreme conditions when a cold or hot drink is experienced. The results showed that porcelain and porcelain-matrix composites exhibited higher damping capacity while Y-TZP and Y-TZP-matrix composites presented higher dynamic Young's modulus. Furthermore, while damping capacity is strongly influenced by the temperature, no significant difference in dynamic Young's modulus was found. For both damping and modulus properties, no significant influence of frequency was found for the tested materials. Based on the obtained results and also on the known advantages of the graded Y-TZP/porcelain structures over traditional bi-layer solutions (e.g., improved bending strength, enhanced mechanical and thermal stress distribution), a novel design of all-ceramic restoration with damping capacity has been proposed at the end of this study. A positive impact on the long-term performance of these all-ceramic restorations may be expected.


Asunto(s)
Porcelana Dental/química , Módulo de Elasticidad , Ensayo de Materiales , Itrio/química , Circonio/química , Adhesividad , Dureza , Temperatura
6.
J Biomed Mater Res B Appl Biomater ; 107(4): 1113-1121, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30230711

RESUMEN

Different zirconia porous layers were produced on zirconia dense zirconia substrates by slip casting using powder with different mean sizes: 40 µm (Z40), 70 µm (Z70), and 100 µm (Z100). The dynamic and static coefficients of friction against bovine femoral bone, mimicking the implantation process, were conducted using a ball-on-flat reciprocating sliding tribometer under 3 N of normal load. Additionally, the porous layers were assessed with regard to their low temperature degradation (aging). Results revealed that the porous layers were able to keep their integrity during the sliding testes against bone, with no zirconia particles being transferred to the bone. Results did not show significant differences (p > 0.05) in kinetic and static COF values for Z40, Z70, Z100, and GRAD specimens, ranging from 0.53 to 0.77 and 0.65 to 0.90, respectively. The aging tests revealed that all surfaces were prone to low temperature degradation (~49% of monoclinic content after 18 h). In conclusion, the cohesive integrity of the layers and relatively high COF observed reveled that zirconia porous layers may be considered for replacing the current implant surfaces, and are expected to improve their primary stability. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1113-1121, 2019.


Asunto(s)
Interfase Hueso-Implante/patología , Fémur , Implantes Experimentales , Circonio , Animales , Bovinos , Fémur/química , Fémur/metabolismo , Fémur/patología , Porosidad
7.
J Biomed Mater Res A ; 105(2): 672-679, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27750384

RESUMEN

Bioactive glasses (BGs) are promising materials for bone repair due to their desirable properties such as osteoconductivity, biodegradability, angiogenic potential, and antibacterial activity. Ionic dissolution products from bioactive glasses increase the medium pH inhibiting surrounding bacteria proliferation. The activity of BGs against biofilm formation has been enhanced by incorporating organic antibacterial compounds. The aim of this review was to summarize evidence in literature which assesses the efficacy of antibacterial and anti-biofilm compounds embedded in bioactive glasses to prevent peri-implant infection during bone healing. A PubMed bibliographical research was carried out including articles published in the last 20 years. Most previous studies evaluated antibacterial efficiency in planktonic cultures but did not investigate biofilm inhibition, underestimating biofilm clinical relevance. Multifactorial features such as biocompatibility of embedded compounds, receptor site characteristics, and drug delivery efficiency have been found to influence the bioactive glass capability of acting both as an anti-biofilm agent and as a bone repairing biomaterial. Accordingly, further in vitro and in vivo studies are required to select the most promising anti-biofilm agents which should be incorporated into bioactive glasses to counteract biofilm proliferation, without inducing toxic effects on human cells, and with the added functionality of promoting bone regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 672-679, 2017.


Asunto(s)
Antiinfecciosos , Biopelículas/efectos de los fármacos , Regeneración Ósea/efectos de los fármacos , Sustitutos de Huesos , Cerámica , Materiales Biocompatibles Revestidos , Animales , Antiinfecciosos/química , Antiinfecciosos/uso terapéutico , Biopelículas/crecimiento & desarrollo , Sustitutos de Huesos/química , Sustitutos de Huesos/uso terapéutico , Cerámica/química , Cerámica/uso terapéutico , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/uso terapéutico , Humanos
8.
J Biomed Mater Res A ; 105(2): 590-600, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27750402

RESUMEN

In this work, TiO2 ceramic scaffolds were fabricated by the replica method using polyurethane (PU) sponges. Suspensions with high solid content were used to achieve scaffolds with improved mechanical behavior. TiO2 ceramic suspensions were optimized by rheological studies using different additives. It was found that the composition with 0.5 wt % Darvan enhanced the covering of the sponge struts. PU sponges of 45 to 80 ppi (pore per inch) were well coated without clogging pores. A thermal treatment with varying holding times, temperatures and heating rates was adjusted. The influence of different pore sizes on mechanical strength was evaluated. It was possible to obtain TiO2 scaffolds with 90% porosity and high pore interconnectivity, having compressive strength exceeding 0.6 MPa. TiO2 scaffolds were filled up with a 58S bioactive glass suspension to impart bioactive character to the scaffolds. These hybrid structures presented mechanical strengthening of about 26-213% depending on their sponge porosity. The prediction for cells viability via zeta potential measures indicated that this hybrid material is very promising for scaffold application with -19 to -25 mV between pH of 7.35-7.45. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 590-600, 2017.


Asunto(s)
Vidrio/química , Estrés Mecánico , Andamios del Tejido/química , Titanio/química , Concentración de Iones de Hidrógeno , Porosidad
9.
J Biomed Mater Res A ; 105(7): 1994-2003, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28263451

RESUMEN

Bioactive glass is an attractive biomaterial that has shown excellent osteogenic and angiogenic effects for oral bone repairing procedures. However, anti-biofilm potential related to such biomaterial has not been completely validated, mainly against multi-species biofilms involved in early tissue infections. The aim of the present study was to evaluate the anti-biofilm effect of 58 S bioactive glass embedding calcium bromide compounds at different concentrations. Bioactive glass free or containing 5, or 10 wt % CaBr2 was synthesized by alkali sol-gel method and then characterized by physco-chemical analyses and scanning electron microscopy (SEM). Then, samples were tested by microbiological assays using optical density, real time q-PCR, and SEM. Bioactive glass particles showed accurate chemical composition and an angular shape with a bimodal size distribution ranging from 0.6 to 110 µm. The mean particle size was around 29 µm. Anti-biofilm effect was recorded for 5 wt % CaBr2 -doped bioactive glass against S. mitis, V. parvula, P. gingivais, S. gordoni, A. viscosus, F, nucleatum, P. gingivais. F. nucleatum, and P. gingivalis. Such species are involved in the biofilm structure related to infections on hard and soft tissues in the oral cavity. The incorporation of calcium bromide into bioactive glass can be a strategy to enhance the anti-biofilm potential of bioactive glasses for bone healing and infection treatment. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1994-2003, 2017.


Asunto(s)
Bacterias/crecimiento & desarrollo , Fenómenos Fisiológicos Bacterianos , Biopelículas/crecimiento & desarrollo , Bromuros/química , Vidrio/química , Boca/microbiología
10.
Arch Dermatol Res ; 270(3): 325-31, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-7271316

RESUMEN

The diameters of Sudan Black B stained sebum vesicles and acid hematein stained perinuclear granules, and the numerical density of the latter, were determined in mature sebaceous preputial cells from normal male and female rats, testosterone-treated female rats and estradiol-treated male rats. Statistical analysis by Student's t-test showed that the diameter of lipid droplets was significantly higher in male than in female controls and that testosterone increased female values up to make control levels. Estradiol treatment decreased male values to levels below those of normal male and female controls and of testosterone-treated female rats. Diameters of perinuclear granules did not vary among animal groups but their numerical density was larger in testosterone treated than in normal female rats or estradiol treated male rats. Lipid droplet sizes and perinuclear granule numbers are thus increased by androgens and decreased by estrogens, which was interpreted an meaning that sexual hormones do not only act on sebaceous cell multiplication or turnover time as previously known, but also on the production of lipid and the output of beta-glucuronidase containing granules in this gland.


Asunto(s)
Estradiol/farmacología , Metabolismo de los Lípidos , Proteínas/metabolismo , Glándulas Sebáceas/efectos de los fármacos , Testosterona/farmacología , Animales , Gránulos Citoplasmáticos/efectos de los fármacos , Femenino , Masculino , Ratas , Sebo/efectos de los fármacos , Tasa de Secreción/efectos de los fármacos
11.
Ocul Immunol Inflamm ; 1(1-2): 171-8, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-22827211

RESUMEN

Toxic epidermal necrolysis (TEN) or Lyell's syndrome is an acute life-threatening disease often triggered by an adverse drug reaction and/or infection. It is characterized by an extensive epidermal loss and severe mucosal involvement. Its pathophysiology is unresolved, but several studies support the hypothesis of an immune mediation. The authors review the ocular involvement of ten drug-induced TEN cases observed in the last four years (eight females and two males; mean age=47). An epidermal loss ranging from 24 to 95% of body surface area was associated with ocular (10/10), oral (9/10), genital (6/10) and anal (4/10) involvement. Ocular findings in the acute phase were: bilateral mucopurulent conjunctivitis (9/10), with inflammatory membranes (3/10), punctate epithelial keratitis (6/10) and corneal ulcers (3/10). Skin palpebral detachment occurred in seven cases, all with extensive and severe systemic disease. In the chronic phase of the disease the authors observed keratoconjunctivitis sicca (4/7), symblepharon (3/7), entropion with trichiasis (2/7) and corneal neovascularization (2/7). HLA B44 (B12) was observed in four of eight studied patients. In conclusion, ocular involvement is frequent in TEN patients and, in those who survive, it significantly contributes to the morbidity of the disease.

12.
Cutis ; 40(1): 41-3, 1987 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2822359

RESUMEN

We describe a patient with multiple silica granulomas in the skin occurring fifteen years after trauma produced by the explosion of a land mine. The presence of silica in the granulomas was confirmed by x-ray microanalysis.


Asunto(s)
Explosiones , Granuloma/etiología , Personal Militar , Dióxido de Silicio/efectos adversos , Enfermedades de la Piel/etiología , Adulto , Granuloma/patología , Humanos , Masculino , Enfermedades de la Piel/patología , Factores de Tiempo , Guerra , Heridas y Lesiones/complicaciones
13.
Cutis ; 67(3): 243-5, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11270300

RESUMEN

We describe the case of a 38-year-old epileptic man with tufted hair folliculitis. The condition started 5 years ago after a scalp laceration that had been sustained 3 months earlier during an epileptic crisis. There then appeared a circumscribed inflammatory bulging lesion (with exudation and crusts) that evolved to scarring alopecia with tufts of 20 to 30 apparently normal hair shafts. Results of bacteriologic examination of pus extruding from the dilated follicular ostia revealed Staphylococcus aureus. The cutaneous pathologic examination showed polymorphous inflammatory exudate in the upper and mid dermis, which was mostly perifollicular, and the presence of normal and independent follicles in the deep dermis, which, while ascending, converged to a common dilated follicular channel. The patient was treated successively with oral flucloxacillin, erythromycin, ciprofloxacin, and amoxicillin/clavulanic acid and with topical application of erythromycin, clindamycin, povidone iodine, and ketoconazole. Transient improvement was followed by recurrence and enlargement of the affected area.


Asunto(s)
Epilepsia , Foliculitis/diagnóstico , Cuero Cabelludo/lesiones , Infecciones Estafilocócicas/diagnóstico , Adulto , Diagnóstico Diferencial , Foliculitis/patología , Humanos , Masculino , Infecciones Estafilocócicas/patología
14.
Med Cutan Ibero Lat Am ; 15(3): 205-7, 1987.
Artículo en Portugués | MEDLINE | ID: mdl-3312863

RESUMEN

A case of sebaceous trichofolliculoma on the nose of a 42 year old man, present at the birth, is reported. The histology was typical, with a cavity formed by the skin of the nose having numerous well developed sebaceous glands along with vellus and terminal hairs.


Asunto(s)
Glándulas Sebáceas/patología , Neoplasias Cutáneas/patología , Adulto , Humanos , Masculino , Nariz , Neoplasias Cutáneas/cirugía
15.
Med Cutan Ibero Lat Am ; 14(4): 255-9, 1986.
Artículo en Portugués | MEDLINE | ID: mdl-3537586

RESUMEN

We describe two cases of Peutz-Jeghers syndrome, a 13 years old female and a 8 years old male patients. In the first case the patient showed pigmented macules on lips, face and oral mucosa, as well as gastric and jejunal polyposis which caused total gastrectomy and segmental enterectomy. The second patient had melanosis on the lower lip, face, buccal mucosa, forearms and perianal area, and the gastric endoscopy revealed two small gastric polyps on the angular incisura.


Asunto(s)
Síndrome de Peutz-Jeghers/patología , Adolescente , Niño , Femenino , Humanos , Masculino
16.
Med Cutan Ibero Lat Am ; 15(3): 208-12, 1987.
Artículo en Portugués | MEDLINE | ID: mdl-3312864

RESUMEN

We describe a 35 year old woman with shortness of stature, skin and muscle atrophy of the face and lower limbs, peripheric arthropathies, feet deformity, plantar hiperqueratosis, alopecia, canities, bilateral cataracts and bitonal voice. At the age of 21, the patient started having plantar hiperqueratosis, deformity and stiffness of the feet joints. At the time of the examination the patient had neither diabetes mellitus, nor peripheric arteriopathies or neoplasms. There wasn't a family history and the parents weren't consanguinous.


Asunto(s)
Síndrome de Werner/diagnóstico , Adulto , Femenino , Humanos , Síndrome de Werner/patología
19.
Dermatologica ; 162(3): 157-66, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-7195832

RESUMEN

In the epidermis from 4 cases of X-linked ichthyosis, granular cells contained a large number of keratohyalin granules of irregular surface, the largest ones having a spongy appearance. Keratinosomes were normal both in number and degree of extrusion. Corneal cells were linked by desmosomal discs up to the most superficial layers. The abnormal persistence of desmosomal discs may be a consequence of a decrease in the activity of acid hydrolases within the keratinosomes. In corneal cells there were a great number of melanosomes with normal appearance which may be responsible for scale pigmentation. Such increased number may be attributed to a deficiency in melanosome spontaneous degradation, rather than to an increased formation.


Asunto(s)
Ictiosis/patología , Piel/ultraestructura , Adolescente , Adulto , Niño , Femenino , Ligamiento Genético , Humanos , Ictiosis/genética , Masculino , Melanocitos/ultraestructura , Microscopía Electrónica , Cromosoma X
20.
J Submicrosc Cytol ; 16(2): 387-94, 1984 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-6201624

RESUMEN

In order to obtain information about the mechanism of dyskeratosis in Darier's disease, we have examined skin sections at different steps of differentiation at light and electron microscopic level in three patients. Corps ronds occurred at the basal aspect of spinous layer, while grains were abundant in the bulla and in the granular layer of the peripheral epidermis. Corps ronds contained cytoplasmic vacuoles and great number of keratinosomes. Their cytoplasm was divided by a circular ring of tonofilaments into a juxtanuclear and a peripheral compartment. More superficially corps ronds became dyskeratotic keratohyalin-containing cells by acquiring increasing amounts of keratohyalin granules; the cytoplasm turned more vacuolated and poor in keratinosomes. Grains exhibited nuclear pyknosis, shrinkage and densification of mitochondria, numerous tonofilament bundles and confluent vacuoles after disruption of their membrane. In these cells, keratohyalin granules appeared less electrondense and keratinosomes were rare or absent. Horny cells contained empty areas resulting from the persistence of vacuolar spaces. These observations suggest that corps ronds and grains represent stages in the same successive differentiation line and that grains give rise to the changed horny cells occurring in this condition.


Asunto(s)
Enfermedad de Darier/fisiopatología , Piel/fisiopatología , Adulto , Anciano , Diferenciación Celular , Gránulos Citoplasmáticos/ultraestructura , Enfermedad de Darier/patología , Desmosomas/ultraestructura , Femenino , Humanos , Hialina/análisis , Queratinas/análisis , Microscopía Electrónica , Piel/ultraestructura , Vacuolas/ultraestructura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA