Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.214
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
N Z Vet J ; : 1-7, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39079681

RESUMEN

CASE HISTORY: In 2023, the New Zealand Department of Conservation seized 63 endemic reptiles that were being held without a permit. This group included three adult female West Coast green geckos (Naultinus tuberculatus) that had been illegally removed from the wild 2 years earlier. They had been held in an outdoor enclosure with a pair of goldstripe geckos (Woodworthia chrysosiretica). CLINICAL FINDINGS: On physical examination, all three geckos had at least two soft palpable masses in the coelom. Repeated ultrasonographic examination over several months confirmed the diagnosis of pre-ovulatory follicular stasis (POFS) in each gecko, and in subsequent weeks, more ovarian follicles developed in each animal. LABORATORY FINDINGS: All three geckos were negative on culture of cloacal swabs for Salmonella spp., and negative on PCR assay of a cloacal flush for Cryptosporidium spp., despite other reptiles in the seized group showing positive results for multiple Salmonella spp., and one other gecko being positive for Cryptosporidium parvum, subtype IIcA5G3. TREATMENT AND OUTCOME: For all three geckos, para-midline ventral coeliotomy was performed under general anaesthesia, and folliculectomy of degenerate ovarian follicles was performed. Post-operative complications were seen in all three animals, which developed suture-line infections following disruption of normal skin shedding and entrapment of shed keratin in the surgical sites. A second surgery was undertaken to remove impacted keratin and caseous inflammatory material from the surgical wounds of all three animals and buried sutures were placed to close the coelomic wounds. The geckos were treated with 20 mg/kg ceftazidime IM every second day for 2 weeks post-operatively. Subsequent ecdysis (skin shedding) occurred without complication and the geckos were released back to the wild 10 months after admission. CLINICAL RELEVANCE: The recommended treatment for POFS in reptiles is ovariectomy, which is not appropriate for wild animals. The use of folliculectomy to resolve preovulatory follicular stasis should be considered for animals where retaining reproductive ability is essential.

2.
Phys Rev Lett ; 131(9): 092502, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37721815

RESUMEN

We successfully performed electron scattering off unstable nuclei which were produced online from the photofission of uranium. The target ^{137}Cs ions were trapped with a new target-forming technique that makes a high-density stationary target from a small number of ions by confining them in an electron storage ring. After developments of target generation and transportation systems and the beam stacking method to increase the ion beam intensity up to approximately 2×10^{7} ions per pulse beam, an average luminosity of 0.9×10^{26} cm^{-2} s^{-1} was achieved for ^{137}Cs. The obtained angular distribution of elastically scattered electrons is consistent with a calculation. This success marks the realization of the anticipated femtoscope which clarifies the structures of exotic and short-lived unstable nuclei.

3.
Geophys Res Lett ; 49(15): e2022GL099655, 2022 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-36247517

RESUMEN

Microbursts are impulsive (<1 s) injections of electrons into the atmosphere, thought to be caused by nonlinear scattering by chorus waves. Although attempts have been made to quantify their contribution to outer belt electron loss, the uncertainty in the overall size and duration of the microburst region is typically large, so that their contribution to outer belt loss is uncertain. We combine datasets that measure chorus waves (Van Allen Probes [RBSP], Arase, ground-based VLF stations) and microburst (>30 keV) precipitation (FIREBIRD II and AC6 CubeSats, POES) to determine the size of the microburst-producing chorus source region beginning on 5 December 2017. We estimate that the long-lasting (∼30 hr) microburst-producing chorus region extends from 4 to 8 Δ MLT and 2-5 Δ L. We conclude that microbursts likely represent a major loss source of outer radiation belt electrons for this event.

4.
Phys Rev Lett ; 124(10): 102501, 2020 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-32216444

RESUMEN

Interaction cross sections for ^{42-51}Ca on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

5.
Phys Rev Lett ; 118(26): 262501, 2017 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-28707914

RESUMEN

The first elastic electron scattering has been successfully performed at the self-confining radioactive-isotope ion target (SCRIT) facility, the world's first electron scattering facility for SCRIT technique achieved high luminosity (over 10^{27} cm^{-2} s^{-1}, sufficient for determining the nuclear shape) with only 10^{8} target ions. While ^{132}Xe used in this time as a target is a stable isotope, the charge density distribution was first extracted from the momentum transfer distributions of the scattered electrons by comparing the results with those calculated by a phase shift calculation.

6.
Reprod Domest Anim ; 52(4): 655-660, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28370483

RESUMEN

In this study, sperms collected from the right and left cauda epididymis were grouped into having canine prostatic fluid (PF) sensitization or not diluted with egg yolk Tris-fructose citrate extender, and stored at 4°C. The necessity of canine PF in cooled preservation was determined by elucidating the sperm quality after the storage. As a result, while there was no difference among all groups up to 48 hr of storage, after storage for 96 hr and more, a significantly lower sperm motility was observed in the group without being sensitized to PF than the groups with being sensitized to PF (p < .05, p < .01). Although sperm abnormality increased in all groups with increased storage time, the group without being sensitized to PF showed significantly higher sperm abnormality than did the groups with being sensitized to PF after storage for 24 hr and more (p < .01). From these findings, we concluded that PF was necessary for the cooled preservation of the canine sperm because these sperms were protected from any effects of low temperatures by being sensitized to PF.


Asunto(s)
Líquidos Corporales/fisiología , Perros/fisiología , Próstata , Preservación de Semen/veterinaria , Motilidad Espermática/fisiología , Espermatozoides/fisiología , Animales , Frío , Epidídimo/citología , Masculino , Análisis de Semen
7.
Lymphology ; 49(2): 93-106, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29906367

RESUMEN

Patients with breast cancer-related lymphedema (BCRL) need a life-long self-care program that they can adhere to enable them to manage their lymphedema. The objective of this study was to assess the effectiveness of a holistic BCRL self-care program that patients could easily adhere to and comply with. A prospective, longitudinal, comparative study between affected arms and unaffected arms in unilateral breast cancer patients was implemented over a six-month period. Both the lymphedematous and unaffected arms of 23 patients with unilateral BCRL were followed and measured. The daily 10-minute holistic BCRL self-care program consisted of modified Japanese rajio taiso (Japanese radio calisthenics), a gentle arm exercise combined with deep breathing, skin moisturizing care using a traditional lymphatic drainage technique, and basic self-care education. Arm and edema volume, relative volume change, resistance of the skin to compression (fibrosis), lymphedema-related symptoms, skin condition, and self-care were assessed. At the end of six-months the volume of all limb segments and resistance of the tissues to compression at all measurement points of the affected arm were significantly reduced. On the unaffected side, only the volume of the forearm and the whole arm was significantly reduced and fibrosis significantly reduced only in the forearm. There was no significant difference in edema volume and relative volume change. Lymphedema-related symptoms significantly improved. Perceived adherence, effectiveness, burden, score and average time for self-care significantly increased. Our results demonstrate that this 10-minute self-care program may improve BCRL and its self-care.


Asunto(s)
Linfedema del Cáncer de Mama/terapia , Neoplasias de la Mama/cirugía , Ejercicios Respiratorios/métodos , Terapia por Ejercicio/métodos , Escisión del Ganglio Linfático , Drenaje Linfático Manual/métodos , Mastectomía , Autocuidado/métodos , Cuidados de la Piel/métodos , Actividades Cotidianas , Adulto , Anciano , Aromaterapia , Axila , Quimioterapia Adyuvante , Citrus paradisi , Femenino , Humanos , Japón , Estudios Longitudinales , Mastectomía Segmentaria , Persona de Mediana Edad , Aceites Volátiles/uso terapéutico , Cooperación del Paciente , Educación del Paciente como Asunto , Estudios Prospectivos , Radioterapia Adyuvante , Factores de Tiempo , Resultado del Tratamiento
8.
Clin Transplant ; 28(9): 1025-30, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24974916

RESUMEN

BACKGROUND: Hepatic arterial reconstruction during living donor liver transplantation (LDLT) is a very delicate and technically complicated procedure. Post-LDLT hepatic arterial complications are associated with significant morbidity and mortality. METHODS: We retrospectively analyzed the details of post-operative hepatic arterial complications in 673 consecutive adult LDLT recipients between January 1996 and September 2009. RESULTS: Hepatic arterial complications occurred in 43 of 673 adult recipients (6.4%) within a median of 13 post-transplant days (range, 1-63). These included hepatic artery thrombosis (including anastomotic stenosis) in 33 cases, anastomotic bleeding in seven cases, and rupture of anastomotic aneurysm in three cases. To treat these complications, surgical re-anastomosis was performed in 26 cases, while the other 17 cases underwent conservative therapies, including four angioplasties by interventional radiology. Biliary complications after hepatic arterial complications occurred in 17 cases. The overall survival rate after LDLT was significantly lower in the hepatic arterial complication group compared with that in the non-complication group (60.7% vs. 80.1% at one yr, 44.3% vs. 74.2% at five yr, respectively; p < 0.001). Multivariate analysis showed that the extra-anatomical anastomosis (p = 0.011) was the only independent risk factor for hepatic arterial complications. CONCLUSION: Because hepatic arterial complications after LDLT are associated with poor patient survival, early diagnosis and immediate treatment are crucial. The anatomical anastomosis may be the first choice for the hepatic arterial reconstruction to the extent possible.


Asunto(s)
Arteriopatías Oclusivas/etiología , Arteria Hepática/cirugía , Trasplante de Hígado , Donadores Vivos , Complicaciones Posoperatorias , Adolescente , Adulto , Anciano , Anastomosis Quirúrgica/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Hepatopatías/cirugía , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Receptores de Trasplantes , Adulto Joven
10.
Reprod Domest Anim ; 49(5): E44-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25130649

RESUMEN

Human chorionic gonadotropin (hCG) is a glycoprotein used in the treatment of spermatogenic dysfunction. However, previous studies performed in dogs show that repeated administration of large doses of hCG produces antibodies against hCG. In this study, we examined the efficacy of low-dose injections of hCG in four male dogs with spermatogenic dysfunction and low plasma testosterone (T) levels. We administered 100 IU hCG per animal, five times at 3-day intervals, and evaluated the changes in semen quality and plasma T levels. The total number of sperm in ejaculate, the percentage of progressively motile sperm and the plasma T levels had increased by 3-5 weeks after the first injection of hCG in three of the four dogs, but were unchanged in the fourth dog. These findings indicate that temporary improvement of the semen quality of dogs with spermatogenic dysfunction and low plasma T levels is possible after five low-dose injections of hCG.


Asunto(s)
Gonadotropina Coriónica/uso terapéutico , Infertilidad Masculina/veterinaria , Espermatogénesis/efectos de los fármacos , Animales , Perros , Infertilidad Masculina/tratamiento farmacológico , Masculino , Testosterona/sangre
11.
Nat Genet ; 8(3): 236-42, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7874165

RESUMEN

Hereditary progressive dystonia with marked diurnal fluctuation (HPD) (also known as dopa responsive dystonia) is a dystonia with onset in childhood that shows a marked response without any side effects to levodopa. Recently the gene for dopa responsive dystonia (DRD) was mapped to chromosome 14q. Here we report that GTP cyclohydrolase I is mapped to 14q22.1-q22.2. The identification of four independent mutations of the gene for GTP cyclohydrolase I in patients with HPD, as well as a marked decrease in the enzyme's activity in mononuclear blood cells, confirms that the GTP cyclohydrolase I gene is a causative gene for HPD/DRD. This is the first report of a causative gene for the inherited dystonias.


Asunto(s)
Mapeo Cromosómico , Distonía/genética , GTP Ciclohidrolasa/genética , Mutación , Edad de Inicio , Biopterinas/biosíntesis , Encéfalo/enzimología , Cromosomas Humanos Par 14 , Ritmo Circadiano , Clonación Molecular , Análisis Mutacional de ADN , Dopamina/biosíntesis , Distonía/clasificación , Distonía/tratamiento farmacológico , Distonía/epidemiología , Escherichia coli , Femenino , GTP Ciclohidrolasa/sangre , Heterocigoto , Humanos , Células Híbridas , Levodopa/uso terapéutico , Masculino , Mutagénesis Sitio-Dirigida , Proteínas del Tejido Nervioso/metabolismo , Linaje , Reacción en Cadena de la Polimerasa , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Tirosina 3-Monooxigenasa/metabolismo
12.
Nat Commun ; 14(1): 6143, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37903790

RESUMEN

Both solar wind and ionospheric sources contribute to the magnetotail plasma sheet, but how their contribution changes during a geomagnetic storm is an open question. The source is critical because the plasma sheet properties control the enhancement and decay rate of the ring current, the main cause of the geomagnetic field perturbations that define a geomagnetic storm. Here we use the solar wind composition to track the source and show that the plasma sheet source changes from predominantly solar wind to predominantly ionospheric as a storm develops. Additionally, we find that the ionospheric plasma during the storm main phase is initially dominated by singly ionized hydrogen (H+), likely from the polar wind, a low energy outflow from the polar cap, and then transitions to the accelerated outflow from the dayside and nightside auroral regions, identified by singly ionized oxygen (O+). These results reveal how the access to the magnetotail of the different sources can change quickly, impacting the storm development.

13.
Am J Transplant ; 12(12): 3406-13, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22994696

RESUMEN

Few studies have examined the long-term outcomes and prognostic factors associated with pediatric living living-donor liver transplantation (LDLT) using reduced and hyper-reduced left lateral segment grafts. We conducted a retrospective, single-center assessment of the outcomes of this procedure, as well as clinical factors that influenced graft and patient survival. Between September 2000 and December 2009, 49 patients (median age: 7 months, weight: 5.45 kg) underwent LDLT using reduced (partial left lateral segment; n = 5, monosegment; n = 26), or hyper-reduced (reduced monosegment grafts; n = 18) left lateral segment grafts. In all cases, the estimated graft-to-recipient body weight ratio of the left lateral segment was more than 4%, as assessed by preoperative computed tomography volumetry, and therefore further reduction was required. A hepatic artery thrombosis occurred in two patients (4.1%). Portal venous complications occurred in eight patients (16.3%). The overall patient survival rate at 1, 3 and 10 years after LDLT were 83.7%, 81.4% and 78.9%, respectively. Multivariate analysis revealed that recipient age of less than 2 months and warm ischemic time of more than 40 min affected patient survival. Pediatric LDLT using reduced and hyper-reduced left lateral segment grafts appears to be a feasible option with acceptable graft survival and vascular complication rates.


Asunto(s)
Supervivencia de Injerto/fisiología , Arteria Hepática/patología , Trasplante de Hígado/mortalidad , Vena Porta/patología , Complicaciones Posoperatorias , Femenino , Rechazo de Injerto , Humanos , Lactante , Recién Nacido , Trasplante de Hígado/efectos adversos , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Trombosis/etiología , Trombosis/mortalidad
14.
Eur Surg Res ; 48(3): 163-70, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22653087

RESUMEN

BACKGROUND: After small-for-size graft (SFSG) transplantation, elevated portal venous pressure (PVP) may lead to postoperative liver damage. Herein we evaluated the impact of portocaval shunt (PCS) to control PVP on liver grafts and intestine following SFSG transplantation. METHODS: Nineteen SFSG transplantations were performed with 30% of native liver in swine. Swine were divided into 3 groups: a high-flow shunt group (HS: n = 7), in which portal venous flow (PVF) was reduced with a 10-mm diameter PCS; a low-flow shunt group (LS: n = 6), in which PVF was reduced with a 5-mm diameter PCS, and a no-shunt group (NS: n = 6), in which no PCS was placed. RESULTS: Seven-day survivals were 83.3% in NS, 100% in LS and 0% in HS (p = 0.0088). PVP was significantly higher in the NS group (p = 0.0001; mean ± SEM NS/LS/HS: 20.5 ± 0.7/14.0 ± 1.2/11.6 ± 0.5 mm Hg). The LS group exhibited the highest compliance (PVF/PVP; NS/LS/HS 42.7 ± 10.9/44.6 ± 4.9/37.7 ± 8.3 ml/min/mm Hg; p = 0.009), the lowest aspartate aminotransferase (NS/LS/HS 562 ± 18/370 ± 55/720 ± 130 IU/l; p = 0.0493), and suppressed deleterious alternations of the hepatic parenchyma and intestinal mucosa. CONCLUSIONS: Portal hypertension after SFSG transplantation impaired liver and intestinal mucosa; however, inadequate portal flow impaired not only the liver, but also survival.


Asunto(s)
Mucosa Intestinal/patología , Trasplante de Hígado , Vena Porta/fisiología , Animales , Aspartato Aminotransferasas/sangre , Femenino , Hígado/patología , Derivación Portocava Quirúrgica , Porcinos , Presión Venosa
15.
Reprod Domest Anim ; 47 Suppl 6: 43-6, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23279463

RESUMEN

As a step towards elucidation of the timing and mechanism of the determination of the number of ovulated ova in dogs, we excised one ovary 2, 5 and 8 days after the beginning of vulval bleeding and examined whether the lost ovulation function, assessed by estimating the number of ovulated oocytes, would be compensated for by the remaining ovary. The number of ovulated ova was maintained by the remaining ovary in the group that underwent unilateral ovariectomy 2 days after the beginning of vulval bleeding. However, in the groups ovariectomized 5 or 8 days after the beginning of vulval bleeding, no compensation for the number of ova that would have been ovulated from the lost ovary was observed; ova were ovulated only from the follicles 3 mm or greater in diameter observed in the remaining ovary at unilateral ovariectomy. Thus, in dogs, the number of ovulated ova is considered to be determined within 5 days after the beginning of vulval bleeding.


Asunto(s)
Perros/fisiología , Ovariectomía/veterinaria , Ovulación/fisiología , Animales , Femenino , Folículo Ovárico/fisiología
16.
Reprod Domest Anim ; 47 Suppl 6: 47-51, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23279464

RESUMEN

This study investigated the duration of the interval between the onset of vulval bleeding at pro-oestrus and ovulation estimated from the plasma progesterone concentration in a large number of beagle bitches. The influence and association of individual variation, ageing and duration of the oestrous cycle were also investigated. The mean time of ovulation after the onset of vulval bleeding was 11.1 ± 0.2 days, but it widely ranged from 3 to 31 days. This timing was not influenced by age or duration of the oestrous cycle, and within-individual variation was small. As there has been no previous report in which the ovulation day was investigated by the age, these data may be very valuable.


Asunto(s)
Perros/fisiología , Estro/fisiología , Ovulación/fisiología , Animales , Femenino
17.
Space Sci Rev ; 218(5): 38, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35757012

RESUMEN

This paper presents the highlights of joint observations of the inner magnetosphere by the Arase spacecraft, the Van Allen Probes spacecraft, and ground-based experiments integrated into spacecraft programs. The concurrent operation of the two missions in 2017-2019 facilitated the separation of the spatial and temporal structures of dynamic phenomena occurring in the inner magnetosphere. Because the orbital inclination angle of Arase is larger than that of Van Allen Probes, Arase collected observations at higher L -shells up to L ∼ 10 . After March 2017, similar variations in plasma and waves were detected by Van Allen Probes and Arase. We describe plasma wave observations at longitudinally separated locations in space and geomagnetically-conjugate locations in space and on the ground. The results of instrument intercalibrations between the two missions are also presented. Arase continued its normal operation after the scientific operation of Van Allen Probes completed in October 2019. The combined Van Allen Probes (2012-2019) and Arase (2017-present) observations will cover a full solar cycle. This will be the first comprehensive long-term observation of the inner magnetosphere and radiation belts.

18.
Kyobu Geka ; 64(5): 406-9, 2011 May.
Artículo en Japonés | MEDLINE | ID: mdl-21591444

RESUMEN

A 52-year-old woman who presented with acute onset of chest pain was diagnosed with Stanford type A acute aortic dissection by computed tomography at another hospital. She was referred to our department for emergency surgery. The left pericardium visualized via a median sternotomy was clearly defective, and the left phrenic nerve was located ventral to the defect. The ascending aorta and total arch were replaced with an aortic valve and a prosthetic graft, respectively. Postoperative chest radiography excluded left phrenic nerve palsy. The postoperative course was uneventful and the patient was discharged on postoperative day 17.


Asunto(s)
Aneurisma de la Aorta/cirugía , Disección Aórtica/cirugía , Pericardio/anomalías , Enfermedad Aguda , Femenino , Humanos , Persona de Mediana Edad
19.
Sci Rep ; 11(1): 13724, 2021 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-34257336

RESUMEN

Pulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

20.
J Exp Med ; 185(1): 141-51, 1997 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-8996250

RESUMEN

We have investigated whether in the human thymus transition of CD4+CD8+ double positive (DP) to CD4+ or CD8+ single positive (SP) cells is sufficient for generation of functional immunocompetent T cells. Using the capacity of thymocytes to expand in vitro in response to PHA and IL-2 as a criterion for functional maturity, we found that functional maturity of both SP and DP thymocytes correlates with downregulation of CD1a. CD1a- cells with a persistent DP phenotype were also found in neonatal cord blood, suggesting that at least a proportion of mature DP cells can emigrate from the thymus. The requirements for generating functional T cells were investigated in a hybrid human/mouse fetal thymic organ culture. MHC class II-positive, but not MHC class II-negative, mouse thymic microenvironments support differentiation of human progenitors into TCR alpha beta+CD4+ SP cells, indicating that mouse MHC class II can positively select TCR alpha beta +CD4+ SP human cells. Strikingly, these SP are arrested in the CD1a+ stage and could not be expanded in vitro with PHA and IL-2. CD1a+CD4+ SP thymocytes do not represent an end stage population because purified CD1a+CD4+ SP thymocytes differentiate to expandable CD1a- cells upon cocultivation with human thymic stromal cells. Taken together these data indicate that when CD1a+ DP TCR alpha beta low cells mature, these cells interact with MHC, but that an additional, apparently species-specific, signal is required for downregulation of CD1a to generate functional mature TCR alpha beta + cells.


Asunto(s)
Antígenos CD1/biosíntesis , Antígenos CD/biosíntesis , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio , Linfocitos T/inmunología , Timo/inmunología , Envejecimiento/inmunología , Animales , Antígenos CD4/biosíntesis , Diferenciación Celular , Niño , Preescolar , Cartilla de ADN , Citometría de Flujo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/inmunología , Humanos , Lactante , Activación de Linfocitos , Ratones , Técnicas de Cultivo de Órganos , Reacción en Cadena de la Polimerasa , Biosíntesis de Proteínas , Receptores de Antígenos de Linfocitos T alfa-beta/biosíntesis , Timo/crecimiento & desarrollo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA