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1.
Nature ; 590(7847): 561-565, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33627814

RESUMEN

The fundamental building blocks of the proton-quarks and gluons-have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles and their dynamics give rise to the quantum bound state of the proton and its physical properties, such as its spin1. The two up quarks and the single down quark that comprise the proton in the simplest picture account only for a few per cent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force2. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions in which a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, given that their masses are very similar and small compared to the mass of the proton3. Here we provide evidence from muon pair production measurements that these distributions are considerably different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momenta. These results are expected to revive interest in several proposed mechanisms for the origin of this antimatter asymmetry in the proton that had been disfavoured by previous results4, and point to future measurements that can distinguish between these mechanisms.

3.
Br J Dermatol ; 177(1): 229-237, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28028810

RESUMEN

BACKGROUND: In extramammary Paget disease (EMPD), Paget cells are sometimes detected outside the clinical border (subclinical extension). However, the spreading pattern of Paget cells in subclinical extension remains unclear. In addition, the macroscopic appearances of lesions accompanied by subclinical extension are totally unknown. OBJECTIVES: To characterize the spreading pattern of Paget cells as well as the macroscopic appearance of lesions of EMPD with subclinical extension. METHODS: Nineteen patients with primary anogenital EMPD underwent mapping biopsies and excisional surgeries; biopsy samples were then taken at the periphery of well-demarcated lesions. Samples were transparentized and subjected to whole-mount immunostaining with anticytokeratin 7 antibody to label Paget cells. The histological border was evaluated in three dimensions by two-photon microscopy. The shape and location of the histological border were compared with those of the clinical border. RESULTS: In 21 samples taken at the lesion where subclinical extension was not shown by mapping biopsy, the shape and location of the histological border were almost identical to those of the clinical border. However, two samples exhibited small foci of Paget cells outside the clinical border, showing subclinically extended satellite lesions. In the two samples taken at the lesions where subclinical extension was shown by mapping biopsy, a continuous arrangement of Paget cells extending beyond the clinical border was identified. Subclinically extended Paget cells were detected solely outside hypopigmented patches with erythema. CONCLUSIONS: In EMPD, at least two patterns of subclinical extension exist: continuous and satellite lesions. Subclinical extension might exist preferentially outside hypopigmented patches with erythema.


Asunto(s)
Neoplasias del Ano/patología , Enfermedad de Paget Extramamaria/patología , Neoplasias Cutáneas/patología , Neoplasias Urogenitales/patología , Adulto , Anciano , Anciano de 80 o más Años , Dermoscopía/métodos , Femenino , Humanos , Hipopigmentación/patología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Enfermedad de Paget Extramamaria/cirugía , Fotones , Cuidados Preoperatorios , Neoplasias Cutáneas/cirugía
4.
Br J Dermatol ; 173(4): 1054-8, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25973640

RESUMEN

Docetaxel and paclitaxel are widely used in the treatment of various malignant neoplasms. Taxane-induced sclerosis is dose-dependent and usually not generalized. Little information on the pathogenesis of scleroderma is currently available. Here, we report a case of generalized scleroderma and a case of early-stage oedematous sclerosis, both of which presented with intense versican deposits after administration of taxane for angiosarcoma.


Asunto(s)
Glicosaminoglicanos/metabolismo , Cuero Cabelludo/patología , Esclerodermia Localizada/inducido químicamente , Taxoides/efectos adversos , Versicanos/metabolismo , Docetaxel , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Hemangiosarcoma/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Esclerosis/inducido químicamente , Neoplasias Cutáneas/tratamiento farmacológico
5.
Clin Exp Dermatol ; 39(2): 213-5, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24266764

RESUMEN

Exposure to contact allergens in order to produce allergic contact dermatitis (ACD) seems to induce hair cycle/growth, but the mechanism of this remains unclear. In the current study, we investigated this mechanism and found that repeated application of hapten induced production of interleukin (IL)-4 in lymph-node immune cells. In addition, hair growth was induced in mice after the adoptive transfer of T-helper (Th)2 cells that had been purified from mice exposed to repeated cutaneous application of hapten. These findings lead us to speculate that Th2 cells that are repeatedly hapten-sensitized are recruited to hapten-challenged skin areas, and thus stimulate the production of IL-4 in the vicinity of the hair follicles, which influences hair cycle/growth. Our results may provide fundamental insights into the mechanism of contact hypersensitivity-induced hair cycle/growth.


Asunto(s)
Alérgenos/farmacología , Cabello/efectos de los fármacos , Haptenos/farmacología , Células Th2/inmunología , Administración Cutánea , Animales , Dermatitis Alérgica por Contacto/inmunología , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Cabello/crecimiento & desarrollo , Cabello/inmunología , Interleucina-4/metabolismo , Ratones , Ratones Endogámicos BALB C
6.
Skin Pharmacol Physiol ; 26(1): 22-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23108135

RESUMEN

It has been reported that basic fibroblast growth factor (bFGF) promotes the healing of skin ulceration by inducing fibroblast proliferation, yet the role of bFGF on epidermal barrier function, especially from the perspective of scratch-induced skin abrasion, remains unknown. To this end, we initially developed an epidermal abrasion mouse model induced by scratching with a stainless-steel wire brush, and examined the effects of bFGF on the wound healing induced by skin abrasion. This procedure induced a significant elevation of transepidermal water loss (TEWL) in a scratch-count-dependent manner. This elevated TEWL was significantly decreased following topical application of bFGF to the skin. In addition, bFGF increased the expression of Ki67 in keratinocytes following mechanical scratching. These results suggest that bFGF enhances keratinocyte proliferation, which, in turn, repairs the skin barrier disruption and wounds caused by scratching in mice. Consistently, bFGF stimulated proliferation of normal human epidermal keratinocytes (NHEK). Intriguingly, the effect of bFGF and other growth factors on NHEK proliferation was additive. However, high cell density diminished the effect of bFGF on NHEK proliferation. This particular result can be explained by our observation that FGF receptor mRNA expression in NHEK was low under conditions of high cell density. Our findings suggest that bFGF stimulates keratinocyte proliferation, especially in a lower cell density environment, to repair skin wound in accord with skin barrier recovery.


Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/administración & dosificación , Queratinocitos/efectos de los fármacos , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Adulto , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Células Epidérmicas , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Queratinocitos/citología , Queratinocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/genética , Piel/lesiones , Piel/metabolismo , Agua/metabolismo
7.
Clin Exp Dermatol ; 37(3): 252-8, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22409522

RESUMEN

BACKGROUND: Photoageing of skin is thought to be caused by protein denaturation, which can be induced by ultraviolet radiation. Previous studies have also reported that inflammation is related to protein denaturation; however, the influence of inflammation on skin ageing has not been explored in detail. AIM: To investigate the possible connection between inflammation and protein denaturation, which might lead to skin ageing, we focused on halogenated tyrosine as a denatured substance produced during the inflammation process. METHODS: We measured halogenated tyrosine in aged human skin. Inflammatory cells and halogenated tyrosine were detected by immunohistochemistry using antibodies to mast-cell tryptase, neutrophilic myeloperoxidase and halogenated tyrosine. Finally, using elastic van Gieson (EVG) staining, we investigated whether the sites of halogenated tyrosine coincided with the sites at which proteins were denatured. RESULTS: Immunohistochemical analysis indicated that both inflammatory cells and halogenated tyrosines increased with ageing in both photoexposed and photoprotected skin. EVG staining confirmed that the localization of halogenated tyrosine was close to the sites at which protein was denatured. CONCLUSIONS: Our investigations indicate a possible connection between skin ageing and inflammation, suggesting that halogenated tyrosine could be a useful marker of ageing skin.


Asunto(s)
Inflamación/metabolismo , Desnaturalización Proteica , Envejecimiento de la Piel , Piel/efectos de la radiación , Tirosina/metabolismo , Rayos Ultravioleta/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Niño , Femenino , Halogenación , Humanos , Inmunohistoquímica , Masculino , Mastocitos/citología , Persona de Mediana Edad , Neutrófilos/citología , Piel/citología , Tirosina/efectos de la radiación , Adulto Joven
8.
Clin Exp Dermatol ; 37(8): 904-8, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23050556

RESUMEN

BACKGROUND: High-performance sunscreen protects both healthy consumers and photosensitive patients from strong ultraviolet (UV) exposure. The sun-protection factor (SPF), which indicates the efficacy of UV protection, is determined using a prescribed sunscreen application thickness of 2.0 mg/cm(2). Therefore, users should apply at least 2.0 mg/cm(2) of sunscreen to obtain the level of UV protection expected from a product. In most cases, however, users apply insufficient amounts of sunscreen. AIM: To determine the amount of sunscreen applied under specific conditions, and the relationship between application thickness and SPF value in high-performance sunscreen. METHODS: The amount of applied sunscreen was calculated under practical conditions and conditions that directed a double application. The SPF values of high-performance sunscreen applied at three thicknesses (2.0, 1.0 and 0.5 mg/cm(2)) were determined according to the international SPF testing method. RESULTS. The relationship between SPF value and application thickness correlated in a logarithmic curve. The mean application thickness under practical conditions was approximately 1 mg/cm(2), and directing subjects to use a double application increased the application thickness to nearly 2 mg/cm(2). CONCLUSION: Encouraging a double application of sunscreen will help users apply products at a thickness sufficient to achieve expected SPF efficacy. We recommend that guidance on double application of sunscreen should be posted in public locations where sunscreen is likely to be in use.


Asunto(s)
Piel/efectos de la radiación , Factor de Protección Solar , Quemadura Solar/prevención & control , Protectores Solares/administración & dosificación , Adulto , Pueblo Asiatico , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad
9.
J Eur Acad Dermatol Venereol ; 26(1): 114-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21371134

RESUMEN

BACKGROUND: Cholinergic urticaria (CU) has well-described characteristic clinical presentations, yet the precise pathological mechanism remains incompletely understood. A variety of pathogeneses has been proposed, which suggests that there exists several clinical subtypes. CONCLUSIONS: In this review, we categorize CU into four subtypes: (i) CU with poral occlusion; (ii) CU with acquired generalized hypohidrosis; (iii) CU with sweat allergy; and (iv) idiopathic CU, and discuss diagnostic and treatment options.


Asunto(s)
Receptores Colinérgicos/fisiología , Urticaria/etiología , Humanos , Urticaria/clasificación , Urticaria/fisiopatología , Urticaria/terapia
11.
Br J Dermatol ; 164(5): 1052-60, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21198537

RESUMEN

BACKGROUND: 'FOXP3+ regulatory T cells' (Tregs) are reported to be increased in tumour-bearing hosts including patients with melanoma, leading to tumour immune suppression. However, this idea is challenged by recent evidence that the 'FOXP3+ Treg' fraction in fact contains activated 'nonregulatory' T cells. Also, FOXP3+ T cells are reported to have functionally and kinetically distinct subsets. OBJECTIVES: To investigate whether either or both of regulatory and 'nonregulatory' FOXP3+ T cells are perturbed in patients with melanoma. METHODS: FOXP3+ T cells were classified into three subsets, namely CD45RO+FOXP3(low) nonregulatory T cells, CD45RO+FOXP3(high) effector Tregs, and CD45RO-FOXP3(low) naïve Tregs, according to their expression levels of FOXP3 and CD45RO. The percentage and cytokine production of these FOXP3+ T-cell subsets were assessed by flow cytometry. RESULTS: Both regulatory and nonregulatory T cells were increased in patients with melanoma. Moreover, we found three unexpected perturbations in FOXP3+ T-cell subsets: (i) patients with melanoma showed higher frequencies of FOXP3(low) nonregulatory T cells, which decreased and normalized after tumour removal; (ii) FOXP3(low) naïve Tregs containing higher frequencies of interferon-γ+ cells increased with tumour progression; and (iii) CD45RO+FOXP3(high) effector Tregs were pronouncedly infiltrated around tumour tissues. CONCLUSIONS: These findings demonstrate that patients with melanoma have distinct and differential perturbation of both regulatory and nonregulatory FOXP3+ T cells. The degree of perturbation is associated with tumour burden and progression, suggesting that the perturbation reflects fundamental pathophysiological processes in patients with melanoma. The presented analysis provides a practical approach to investigate the immunological environment of cancer patients.


Asunto(s)
Factores de Transcripción Forkhead/inmunología , Melanoma/inmunología , Neoplasias Cutáneas/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Citocinas/inmunología , Femenino , Citometría de Flujo , Humanos , Antígenos Comunes de Leucocito/metabolismo , Masculino , Melanoma/sangre , Persona de Mediana Edad , Neoplasias Cutáneas/sangre , Adulto Joven
19.
Phys Rev Lett ; 104(17): 172001, 2010 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-20482102

RESUMEN

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

20.
Br J Dermatol ; 161(2): 384-9, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19298271

RESUMEN

BACKGROUND: Recent reports suggest a cross-sectional association between psychiatric distress and pruritus in patients on haemodialysis (HD). However, no study has examined the likelihood of developing severe pruritus in patients on HD with depressive symptoms. OBJECTIVES: To evaluate the relationship between baseline depressive symptoms and subsequent risk of developing severe pruritus. METHODS: A longitudinal study with a 0.5-2.5-year follow-up period was performed using 1799 patients on HD who had no/mild pruritus at baseline, based on the Japan Dialysis Outcomes and Practice Patterns Study (1996-2004), a cohort study composed of a representative sample of patients on HD. We assessed pruritus after the follow-up period using a self-reported questionnaire and depressive symptoms using scores from the five-item version of the Mental Health Inventory (MHI-5). RESULTS: The 1799 patients had a mean age of 56.9 years, 59.5% were men, and 23.6% presented depressive symptoms. Multivariable analysis revealed that patients with depressive symptoms had significantly higher odds of developing severe pruritus during the 0.5-2.5-year follow-up period [adjusted odds ratio (AOR) 1.57, 95% confidence interval 1.22-2.01, P < 0.001]. In addition, a significant linear trend was observed between baseline MHI-5 scores and risk of developing severe pruritus, with AORs for third, second and first MHI-5 score quartiles of 1.08, 1.51 and 1.95, respectively (P for trend < 0.0001). CONCLUSIONS: Our results suggest that depressive symptoms measured by MHI-5 may predict the future risk of developing severe pruritus in patients on HD.


Asunto(s)
Trastorno Depresivo/psicología , Fallo Renal Crónico/psicología , Prurito/psicología , Diálisis Renal/psicología , Femenino , Humanos , Japón , Fallo Renal Crónico/terapia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pautas de la Práctica en Medicina , Prurito/etiología , Diálisis Renal/efectos adversos
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