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1.
Cryo Letters ; 33(1): 45-57, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22434122

RESUMEN

This paper reviews a 10-year experience in establishing a cryopreserved Allium germplasm collection at the genebank of the National Agrobiodiversity Center, Republic of Korea. A systematic approach to Allium cryopreservation included: 1. revealing the most critical factors that affected regeneration after cryostorage; 2. understanding the mechanisms of cryoprotection by analyzing the thermal behavior of explants and cryoprotectant solutions using DSC and influx/efflux of cryoprotectants using HPLC; 3. assessing genetic stability of regenerants; and 4. revealing the efficiency of cryotherapy. Bulbil primordia, i.e. asexual bulbs formed on unripe inflorescences, proved to be the most suitable material for conservation of bolting varieties due to high post-cryopreservation regrowth and lower microbial infection level, followed by apical shoot apices from single bulbs and cloves. A total of 1,158 accessions of garlic as well as some Allium species have been cryopreserved during 2005-2010 using the droplet-vitrification technique with a mean regeneration percentage of 65.9 percent after cryostorage. These results open the door for large-scale implementation of cryostorage and for simplifying international exchange for clonal Allium germplasm.


Asunto(s)
Allium/citología , Criopreservación/métodos , Crioprotectores , Células Germinativas de las Plantas/citología , Allium/fisiología , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Frío , Células Germinativas de las Plantas/fisiología , Enfermedades de las Plantas/virología , Raíces de Plantas/crecimiento & desarrollo , Brotes de la Planta/crecimiento & desarrollo , Virus de Plantas , Regeneración , República de Corea , Vitrificación
2.
Phys Rev Lett ; 105(6): 066602, 2010 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-20867995

RESUMEN

A steady-state electrical current flowing in a magnetic heterostructure can exert a torque on the magnetization, and provides a means to control magnetization states and dynamics in spintronics structures. However, some components of the torque are difficult to measure and to calculate. We have determined the perpendicular spin torque in MgO magnetic tunnel junctions by measuring their lowest ferromagnetic resonance frequency and find that it decreases linearly with increasing bias voltage. Micromagnetic modeling shows that this decrease is caused by the perpendicular component of spin torque. We obtain a quantitative value for the perpendicular spin torque effective field as a function of bias voltage, and show that this effective field is a linear function in bias voltage and approximately equal in magnitude to the in-plane spin torque effective field.

3.
Vet Pathol ; 47(2): 292-7, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20118322

RESUMEN

C hepatica, an important zoonotic parasite, and C fasciolaris are common parasites in rodents. In rodent livers, C hepatica causes sequential morphologic changes that are designated as early, intermediate, or late phase, and C fasciolaris forms cysts surrounded by fibroplasia and granulomatous inflammation. The present study describes the prevalence of these parasites and associated liver and lung lesions in wild rats (Rattus norvegicus) living around pig farms in South Korea. Selected parenchymal organs, including liver and lung, of 89 wild rats were examined. Of 89 rats, 28 (31.5%) were infected with either C hepatica or C fasciolaris or with both parasites. Severe medial hypertrophy of small arterioles was observed in the lungs of 11 of the 28 parasite-infected rats (P < .01). The pulmonary arteriolar hypertrophy in the rats infected with C hepatica was strongly associated with early and/or intermediate phases (88.8%) of morphologic change in the livers (P < .01). As such, this report is the first to suggest a significant association between parasite-induced hepatitis and pulmonary arteriolar hypertrophy in rodents. Further studies are warranted for the use of C hepatica-infected rats as an animal model to explore the underlying mechanisms of portopulmonary hypertension in humans.


Asunto(s)
Animales Salvajes , Parasitosis Hepáticas/veterinaria , Enfermedades Pulmonares Parasitarias/veterinaria , Enfermedades de los Roedores/parasitología , Taenia/aislamiento & purificación , Teniasis/veterinaria , Animales , Histocitoquímica , Corea (Geográfico)/epidemiología , Parasitosis Hepáticas/epidemiología , Parasitosis Hepáticas/parasitología , Enfermedades Pulmonares Parasitarias/epidemiología , Enfermedades Pulmonares Parasitarias/parasitología , Prevalencia , Ratas , Enfermedades de los Roedores/epidemiología , Teniasis/epidemiología , Teniasis/parasitología
4.
Oncogene ; 25(24): 3408-23, 2006 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-16186809

RESUMEN

We have examined the effects of transforming growth factor-beta (TGFbeta) signaling on mammary epithelial cell survival. Transgenic mice expressing an active mutant of Alk5 in the mammary gland (MMTV-Alk5(T204D)) exhibited reduced apoptosis in terminal endbuds and during postlactational involution. Transgene-expressing mammary cells contained lower Smad2/3 and higher c-myc levels than controls, high ligand-independent phosphatidylinositol-3 kinase (PI3K) and Akt activities, and were insensitive to TGFbeta-mediated growth arrest. Treatment with a proteasome inhibitor increased Smad2/3 levels and ligand-independent Smad transcriptional reporter activity, as well as reduced both c-myc protein and basal cell proliferation. Treatment with an Alk5 kinase small-molecule inhibitor upregulated Smad2/3 levels, reduced PI3K activity, P-Akt, and c-myc, and inhibited cell survival. Although Alk5(T204D)-expressing mice did not develop mammary tumors, bigenic MMTV-Alk(T204D) x Neu mice developed cancers that were more metastatic than those occurring in MMTV-Neu transgenics. These data suggest that (1) TGFbeta can signal to PI3K/Akt and enhance mammary epithelial cell survival in vivo before cytological or histological evidence of transformation, and (2) TGFbeta signaling can provide epithelial cells with a 'gain-of-function' effect that synergizes with oncogene-induced transformation.


Asunto(s)
Glándulas Mamarias Animales/metabolismo , Neoplasias Mamarias Animales/patología , Proteínas Serina-Treonina Quinasas/fisiología , Receptores de Activinas Tipo I/metabolismo , Animales , Apoptosis , Supervivencia Celular , Progresión de la Enfermedad , Genes Reporteros , Neoplasias Mamarias Animales/metabolismo , Ratones , Metástasis de la Neoplasia , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/metabolismo
5.
Mol Cell Biol ; 19(9): 6323-32, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10454579

RESUMEN

Activating signal cointegrator 1 (ASC-1) harbors an autonomous transactivation domain that contains a putative zinc finger motif which provides binding sites for basal transcription factors TBP and TFIIA, transcription integrators steroid receptor coactivator 1 (SRC-1) and CBP-p300, and nuclear receptors, as demonstrated by the glutathione S-transferase pull-down assays and the yeast two-hybrid tests. The ASC-1 binding sites involve the hinge domain but not the C-terminal AF2 core domain of nuclear receptors. Nonetheless, ASC-1 appears to require the AF2-dependent factors to function (i.e., CBP-p300 and SRC-1), as suggested by the ability of ASC-1 to coactivate nuclear receptors, either alone or in cooperation with SRC-1 and p300, as well as its inability to coactivate a mutant receptor lacking the AF2 core domain. By using indirect immunofluorescence, we further show that ASC-1, a nuclear protein, is localized to the cytoplasm under conditions of serum deprivation but is retained in the nucleus when it is serum starved in the presence of ligand or coexpressed CBP or SRC-1. These results suggest that ASC-1 is a novel coactivator molecule of nuclear receptors which functions in conjunction with CBP-p300 and SRC-1 and may play an important role in establishing distinct coactivator complexes under different cellular conditions.


Asunto(s)
Receptores Citoplasmáticos y Nucleares/metabolismo , Transactivadores/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Línea Celular , Núcleo Celular/metabolismo , Medio de Cultivo Libre de Suero , Citosol/metabolismo , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Células HeLa , Histona Acetiltransferasas , Humanos , Modelos Biológicos , Datos de Secuencia Molecular , Proteínas Nucleares/metabolismo , Coactivador 1 de Receptor Nuclear , Receptores de Ácido Retinoico/metabolismo , Receptores de Esteroides/metabolismo , Receptores X Retinoide , Homología de Secuencia de Aminoácido , Transducción de Señal , Transactivadores/química , Transactivadores/genética , Factores de Transcripción/metabolismo , Dedos de Zinc
6.
J Invest Dermatol ; 105(1): 80-6, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7615982

RESUMEN

We examined the regulation of cellular retinol-binding protein (CRBP) mRNA and protein expression in human skin in vivo by all-trans retinoic acid and all-trans retinol. Treatment of human skin for 24 h with all-trans retinoic acid (0.1%) or all-trans retinol (1.6%) induced CRBP mRNA 5.5-fold (p < 0.01, n = 10) and 5.7-fold (p < 0.01, n = 5), respectively, compared with skin treated with vehicle or sodium lauryl sulfate (used as an irritant control). In vitro translation of poly A+ RNA from all-trans retinoic acid, all-trans retinol, sodium lauryl sulfate, and vehicle-treated human skin demonstrated that the observed increased CRBP mRNA in all-trans retinoic acid- and all-trans retinol-treated skin was able to direct increased (2.3-2.9-fold) CRBP protein synthesis. Riboprobe in situ hybridization revealed that CRBP mRNA was uniformly elevated throughout the epidermis and in dermal cells after all-trans retinoic acid treatment of human skin. Western analysis revealed that CRBP protein was elevated 3.2-fold (p < 0.01, n = 6) and 3.0-fold (p < 0.01, n = 6) after all-trans retinoic acid treatment of human skin in vivo for 24 and 96 h, respectively, compared with vehicle- and sodium lauryl sulfate-treated skin. In addition, functional CRBP levels measured by [3H]all-trans retinol binding were elevated 1.9-fold (p < 0.01, n = 6) and 3.5-fold (p < 0.01, n = 6) at 24 and 94 h, respectively, after all-trans retinoic acid treatment, compared with vehicle- or sodium lauryl sulfate-treated skin. Gel mobility shift analysis revealed that retinoid receptors in nuclear extracts from human skin formed a specific complex with a DNA probe containing the retinoic acid response element in the mouse CRBP gene. Monoclonal antibodies to nuclear retinoid receptors demonstrated that predominantly retinoic acid receptor-alpha/retinoid X receptor-alpha heterodimers bound to the CRBP retinoic acid response element. These data demonstrate that CRBP expression in human skin in vivo is regulated by exogenous all-trans retinoic acid and all-trans retinol.


Asunto(s)
Proteínas de Unión al Retinol/biosíntesis , Piel/efectos de los fármacos , Tretinoina/farmacología , Secuencia de Bases , Humanos , Hibridación in Situ , Datos de Secuencia Molecular , ARN Mensajero/análisis , Receptores de Ácido Retinoico/metabolismo , Proteínas de Unión al Retinol/genética , Proteínas Celulares de Unión al Retinol , Piel/metabolismo , Vitamina A/metabolismo , Vitamina A/farmacología
7.
J Invest Dermatol ; 116(3): 374-9, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11231310

RESUMEN

We isolated a cDNA clone from grafted mouse skin that encodes a serine protease homologous to human C1r. The C1r protease is involved in the activation of the first component of the classical pathway in the complement system. In order to identify novel transcripts whose expression is regulated in grafted mouse skin, we first performed differential display reverse transcription polymerase chain reaction analysis and obtained 18 partial cDNA clones whose protein products are likely to play an important role in allograft rejection. One of these showed significant sequence homology with human complement C1r precursor. The other clones displayed no homology to any known sequences, however. Northern blot analysis demonstrated that the level of this transcript was upregulated in day 8 postgrafted skin. The full-length cDNA 2121 nucleotides in length obtained from screening a mouse skin cDNA library contained a single open reading frame encoding 707 amino acid residues with a calculated molecular weight of 80,732 Da. Its deduced amino acid sequence revealed an 81% identity and 89% similarity to the human C1r counterpart. In particular, mouse C1r contained His501, Asp559, and Ser656, which were conserved among this group of serine proteases. This protein was thus designated as mouse C1r. We have expressed a truncated fragment of C1r protein without the N-terminal hydrophobic sequence in Escherichia coli and generated a polyclonal antibody against it. Subsequent immunohistochemical analysis confirmed that mouse C1r was significantly expressed 8 d after the skin graft in both allografted and autografted skins, compared with normal skins. These collective data suggest that a component of the complement system, C1r, might contribute to the graft versus host immune responses in mice.


Asunto(s)
Complemento C1r/genética , ADN Complementario/genética , Serina Endopeptidasas/genética , Piel/metabolismo , Animales , Expresión Génica , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Ratones , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Serina Endopeptidasas/metabolismo
8.
J Invest Dermatol ; 105(4): 549-56, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7561157

RESUMEN

We investigated the clinical, histologic, and molecular responses of normal human skin to all-trans-retinol (ROL) application, compared to those induced by topical all-trans-retinoic acid (RA), and measured ROL-derived metabolites. Up to 1.6% ROL, 0.025% RA in vehicle (70% ethanol/30% propylene glycol), or vehicle alone were applied in a double-blind fashion to normal buttock skin and occluded for 4 d. ROL produced from none to only trace erythema, which was clinically and statistically insignificant, whereas RA induced a significant 3.7-fold increase in erythema score compared to vehicle (n = 10, p < 0.01). However, ROL induced significant epidermal thickening (1.5-fold at 1.6% ROL, p < 0.01), similar to RA (1.6-fold at 0.025% RA, p < 0.01), relative to the vehicle. ROL, compared with vehicle, also increased mRNA levels of cellular retinoic acid binding protein (CRABP-II) and cellular retinol binding protein (CRBP) genes as determined by Northern analysis (5-6-fold and 6-7-fold, respectively) and riboprobe in situ hybridization. CRABP-II and CRBP protein levels were also higher following ROL than vehicle treatment, as measured by ligand binding (3.2-fold, p < 0.001; n = 7) and Western analysis (3.6-fold, p < 0.003; n = 6), respectively. Epidermal retinyl ester (RE) content, measured after removal of stratum corneum, rose 240-fold (p < 0.005, n = 5) by 24 h of ROL occlusion. RA content, however, was undetectable or detectable only at trace amounts in all samples obtained at 0, 6, 24, and 96 h after ROL occlusion. Detectability of RA was not correlated with ROL treatment (compared to untreated normal skin, p = 0.86) or baseline skin ROL levels (average r = -0.1, p > 0.3). These data demonstrate that ROL application 1) produces trace erythema not significantly different from vehicle, whereas RA causes erythema; 2) induces epidermal thickening and enhances expression of CRABP-II and CRBP mRNAs and proteins as does RA; 3) causes marked accumulation of retinyl ester; and 4) does not significantly increase RA levels. Taken together, the data are compatible with the idea that ROL may be a prohormone of RA, because it produces changes in skin similar to those produced by RA but without measurable RA or irritation.


Asunto(s)
Erupciones por Medicamentos/etiología , Epidermis/efectos de los fármacos , Eritema/inducido químicamente , Regulación de la Expresión Génica/efectos de los fármacos , Receptores de Ácido Retinoico/biosíntesis , Proteínas de Unión al Retinol/biosíntesis , Tretinoina/análisis , Vitamina A/toxicidad , Administración Cutánea , Adulto , Relación Dosis-Respuesta a Droga , Erupciones por Medicamentos/genética , Erupciones por Medicamentos/metabolismo , Erupciones por Medicamentos/patología , Epidermis/química , Epidermis/patología , Eritema/genética , Eritema/metabolismo , Eritema/patología , Ésteres/aislamiento & purificación , Humanos , Hiperplasia , Hibridación in Situ , Apósitos Oclusivos , Receptores de Ácido Retinoico/genética , Proteínas de Unión al Retinol/genética , Proteínas Celulares de Unión al Retinol , Seguridad , Tretinoina/aislamiento & purificación , Tretinoina/farmacología , Tretinoina/toxicidad , Vitamina A/farmacología
9.
Hypertension ; 28(5): 719-24, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8901814

RESUMEN

Classification schemes for hypertension are necessary. They provide us with definitions for when hypertension begins and help us to assess risk, determine prognosis, and guide management. Systems in current use rely on either the level of blood pressure (diastolic, systolic, or both) and classify patients based on the level of relative risk (the proportional likelihood of cardiovascular events occurring as blood pressure rises), absolute risk (the actual odds that a patient or a population will develop an event), or both. Absolute risk reflects the sum of all the factors that contribute to the likelihood that a patient will experience cardiovascular disease. The system we propose stages hypertensive individuals on the basis of blood pressure level (as does the Fifth Joint National Committee report on the detection, evaluation, and treatment of high blood pressure [JNC-V] and the World Health Organization/International Society of Hypertension guidelines) but uses different levels for each stage than do the previous systems and then modifies the numerical stage with the subscript "c" for complicated (when target-organ damage and/or other cardiovascular risk factors are present) or "u" for uncomplicated (when they are absent). The data obtained from a complete medical history and physical examination and a few inexpensive laboratory tests provide the information a provider needs to classify an individual as being complicated or uncomplicated. This system also provides a guide to treatment, as drug therapy would be used sooner in individuals with complicated hypertension, and we propose that compensation for providers be higher when they are caring for a patient with complicated rather than uncomplicated hypertension.


Asunto(s)
Hipertensión/clasificación , Humanos , Hipertensión/economía , Medición de Riesgo
10.
Mol Cells ; 8(1): 90-5, 1998 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-9571637

RESUMEN

Rac, a member of the Rho family GTPases, has been implicated in the regulation of a wide range of biological processes including actin remodeling, cell transformation, G1 cell cycle progression, and gene expression. To determine whether Rac GTPase activity is required for epidermal growth factor-induced mitogenesis, Rat-2 stable cells expressing a dominant-negative Rac1 mutant, RacN17, were prepared. Exposure to EGF exhibited a significantly restricted growth response in Rat-2-RacN17 cells compared to Rat-2 parental cells, suggesting an essential role of Rac in EGF-induced mitogenesis. In contrast, addition of lysophosphatidic acid exerted the same level of growth in Rat-2 and Rat-2-RacN17 cells. To gain further evidence for the essential role of Rac in EGF-induced mitogenesis, we performed the microinjection experiment. EGF-induced DNA synthesis was significantly blocked by microinjection of recombinant RacN17 protein, and not control IgG. Our further study to analyze the downstream mediator of Rac in EGF-signaling to mitogenesis demonstrated that Rac-activated phospholipase A2 plays a critical role. Taken together, our results suggest that the "Rac and Rac-activated PLA2" cascade is one of the major mitogenic pathways induced by EGF.


Asunto(s)
Factor de Crecimiento Epidérmico/farmacología , GTP Fosfohidrolasas/metabolismo , Proteínas de Unión al GTP/metabolismo , Mitógenos/farmacología , Mitosis/efectos de los fármacos , Animales , División Celular/efectos de los fármacos , Células Cultivadas , ADN/biosíntesis , ADN/efectos de los fármacos , Activación Enzimática , Fibroblastos , GTP Fosfohidrolasas/fisiología , Proteínas de Unión al GTP/genética , Inhibidores de Crecimiento/fisiología , Microinyecciones , Mitosis/genética , Fosfolipasas A/metabolismo , Fosfolipasas A/fisiología , Fosfolipasas A2 , Ratas , Proteínas Recombinantes/farmacología , Proteínas de Unión al GTP rac
11.
Cancer Chemother Pharmacol ; 41(5): 353-60, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9523730

RESUMEN

A human stomach-adenocarcinoma cell line (MKN-45) was selected for resistance to Adriamycin by stepwise exposure to increasing concentrations of this agent. The resulting cell line (MKN/ADR) exhibited a high level of cross-resistance to topoisomerase II (topo II)-targeted drugs such as Adriamycin, mitoxantrone, and etoposide but showed no cross-resistance to other chemotherapeutic agents such as cisplatin, carboplatin, 5-fluorouracil, or mitomycin-C. P-glycoprotein encoded by the mdr-1 gene was not overexpressed in the MKN/ADR cell line. The doubling time of the MKN/ADR cell line (2.1 days) increased only slightly as compared with that of the MKN cell line (1.7 days). The patterns of cross-resistance to various chemotherapeutic agents led us to examine the cellular contents of topo II in both the drug-sensitive and the drug-resistant cells. Extractable topo II enzyme activity was 3-fold lower in MKN/ADR cells as compared with the parental MKN cells. Levels of topoisomerase I (topo I) catalytic activity were similar in both wild-type MKN and drug-resistant MKN/ADR cells. Southern-blot analysis of genomic DNA probed with topo IIalpha or IIbeta showed no sign of either gene rearrangement or hypermethylation. Northern-blot analysis revealed that both topo IIalpha and topo IIbeta mRNA transcripts were essentially identical in the MKN and MKN/ADR cells. In contrast, Western-blot analysis revealed an approximately 20-fold lower level of topo IIalpha in drug-resistant cells as compared with drug-sensitive cells, whereas topo IIbeta levels were similar in both lines. Moreover, the amount of in vivo topo IIalpha-DNA covalent complexes formed in the presence of etoposide was also approximately 20-fold lower in drug-resistant cells. No mutation was detected in the promoter region of the topo IIalpha gene in resistant cells as compared with sensitive cells. Thus, low levels of topo IIalpha polypeptide cannot be ascribed to changes in the mRNA levels. Collectively, the data suggest that a quantitative reduction in topo IIalpha may contribute to the resistance of MKN cells to Adriamycin and other topo II-targeted drugs.


Asunto(s)
Adenocarcinoma/enzimología , Antibióticos Antineoplásicos/farmacología , ADN-Topoisomerasas de Tipo II/efectos de los fármacos , Doxorrubicina/farmacología , Resistencia a Múltiples Medicamentos/genética , Proteínas de Neoplasias/efectos de los fármacos , Neoplasias Gástricas/enzimología , Adenocarcinoma/patología , División Celular/efectos de los fármacos , ADN-Topoisomerasas de Tipo I/metabolismo , ADN-Topoisomerasas de Tipo II/metabolismo , Resistencia a Antineoplásicos , Represión Enzimática , Humanos , Proteínas de Neoplasias/metabolismo , Regiones Promotoras Genéticas/genética , ARN Mensajero/metabolismo , Neoplasias Gástricas/patología , Células Tumorales Cultivadas/efectos de los fármacos
12.
Cardiol Clin ; 13(4): 509-18, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8565014

RESUMEN

Many epidemiologic studies have shown that the risks associated with high blood pressure are considerably greater in those with target-organ damage and other risk factors. Clinical trials also have shown that although lowering blood pressure decreases the incidence of premature cardiovascular diseases, those with target-organ damage and other cardiovascular risk factors benefit considerably more than those with comparable levels of blood pressure who are free of complications or additional risk factors. The classification schemes currently in use for hypertension, which are based only on the level of blood pressure, provide inadequate risk stratification, can be misleading, and may lead to making erroneous therapeutic decisions. We propose a new diagnostic classification for hypertension that combines the level of blood pressure with the presence of other risk factors for premature cardiovascular events and target-organ damage in order to provide a more accurate risk assessment and offer superior guidance for therapeutic decisions. This scheme includes a new category for the elderly with elevated systolic blood pressure, who we now know have excessive morbidity and mortality rates if their diastolic blood pressure is low. Our new classification scheme is simple to use and yet comprehensive, and we feel it provides better risk stratification and is a better guide to therapeutic decision-making than those now in use.


Asunto(s)
Hipertensión/clasificación , Anciano , Presión Sanguínea , Humanos , Hipertensión/diagnóstico , Factores de Riesgo
13.
Arch Dermatol Res ; 293(7): 356-62, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11550809

RESUMEN

To reconstruct the basement membrane in a skin equivalent, the epidermodermal interface was coated with porcine type IV collagen and mouse laminin-1 at various ratios before keratinocyte seeding. Laminin-1, a component of the basement membrane, induced massive infiltration of keratinocytes into the dermal equivalent, while type IV collagen induced discrete demarcation between dermal and epidermal compartments without any infiltrating cells. Immunohistochemical staining indicated that the laminin-induced infiltrating cells expressed endogenous type IV collagens at the cell periphery, which were not incorporated into the basement membrane structure. The infiltrating cells did not express fibronectin receptor alpha5beta1 integrin but showed MMP-9 secretion and cell surface associated MMP-2. However, when laminin-1 was preincubated with type IV collagen, laminin-1-induced keratinocyte infiltration as well as MMP-9 induction were almost completely suppressed to basal levels. Therefore, replenishment of the type IV collagen lattice seemed to cause laminin-stimulated cells to anchor to the lattice, in a similar manner to the basal cells on the basement membrane of normal skin. Our study suggests that the molar ratio of basement membrane components may determine the behavior of basal cells within the wound healing microenvironment, which is probably regulated either by extracellular matrix deposition or degradation.


Asunto(s)
Membrana Basal/fisiología , Laminina/fisiología , Piel Artificial , Células 3T3 , Animales , Antígenos de Superficie/fisiología , Colágeno , Colágeno Tipo IV/fisiología , Fibronectinas/farmacología , Integrina alfa6beta4 , Integrinas/fisiología , Queratinocitos/efectos de los fármacos , Queratinocitos/fisiología , Laminina/antagonistas & inhibidores , Metaloproteinasa 2 de la Matriz/fisiología , Metaloproteinasa 9 de la Matriz/fisiología , Ratones , Porcinos
14.
World J Gastroenterol ; 3(2): 119-20, 1997 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-27041967

RESUMEN

AIM: To analyze clinical features and response to treatment in inflammatory bowel disease (IBD) patients from the Hubei Province of China. METHODS: Clinical data was collected retrospectively from 74 patients with IBD [66 with ulcerative colitis (UC) and 8 with Crohn's disease (CD)] admitted to The Second Hospital, Hubei Medical University from 1986 to 1995. RESULTS: The most common symptoms in IBD patients were abdominal pain, diarrhea, blood and mucus in stool, and constipation. Extraintestinal manifestations of IBD were not common. In these patients, inflammation was predominantly located in the sigmoid and left colon in UC cases, and in the ileum and colon in CD cases. Treatment with sulphasalazine and corticosteroids was effective in 95% of UC cases; However, about 42% of UC patients showed disease recurrence during the follow-up period of 1.11 years. Five out of eight CD patients had part of their intestine removed, whereas three were treated with anti-tuberculosis drugs or the antibiotic metronidazole. Out of four patients we followed up for 1-8 years, one died of severe complications after surgery, two experienced recurrence while in treatment with drugs, and one remained in remission under sulphasalazine treatment after surgery. CONCLUSION: Five percent of the patients reported a family history of IBD. About 34% of the patients were smokers and 32% of the patients were alcoholic. Epidemiological studies are urgently needed in the Hubei Province of China to assess the role that genetics and environmental factors play in the pathogenesis of inflammatory bowel diseases.

15.
Oncogene ; 30(35): 3792-801, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21460850

RESUMEN

The mammalian target of rapamycin (mTOR) is a highly conserved serine-threonine kinase activated in response to growth factors and nutrients. Because of frequent dysregulation of the mTOR signaling pathway in diverse human cancers, this kinase is a key therapeutic target. Redd1 is a negative regulator of mTOR, mediating dissociation of 14-3-3 from tuberous sclerosis complex (TSC)2, which allows formation of a TSC-TSC2 complex. In the present study, we identify TXNIP that inhibits mTOR activity by binding to and stabilizing Redd1 protein. Redd1 and TXNIP expression was induced by a synthetic glucose analog, 2-deoxyglucose (2-DG). Moreover, Redd1 expression in response to 2-DG was regulated by activating transcription factor 4 (ATF4). Overexpression of TXNIP was associated with reduced mTOR activity mediated by an increase in Redd1 level, whereas knockdown of TXNIP using small interfering RNA resulted in recovery of mTOR activity via downregulation of Redd1 during treatment with 2-DG. Interestingly, Redd1 was additionally stabilized via interactions with N-terminal-truncated TXNIP, leading to suppression of mTOR activity. Our results collectively demonstrate that TXNIP stabilizes Redd1 protein induced by ATF4 in response to 2-DG, resulting in potentiation of mTOR suppression. To the best of our knowledge, this is the first study to identify TXNIP as a novel member of the mTOR upstream that acts as a negative regulator in response to stress signals.


Asunto(s)
Proteínas Portadoras/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Factores de Transcripción/metabolismo , Factor de Transcripción Activador 4/metabolismo , Línea Celular Tumoral , Desoxiglucosa/farmacología , Humanos , Estabilidad Proteica , Serina-Treonina Quinasas TOR/antagonistas & inhibidores
16.
Biochem Biophys Res Commun ; 284(2): 419-25, 2001 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-11394895

RESUMEN

We report in this study that proliferation inhibition of SCC13 cells by calcipotriol was possibly mediated by its inhibitory effect on autocrine activation of EGF receptor. Based on MTT assay, PCNA staining, DAPI staining, and involucrin immunocytochemical staining, we showed that calcipotriol inhibited cell growth and stimulated differentiation but did not induce apoptosis. Western blot analysis of concanavalin-A-bound fraction demonstrated that calcipotriol specifically dephosphorylated 170- and 66-kDa polypeptides from 8 h posttreatment and complete dephosphorylation was observed at 12 h posttreatment. The 170- and 66-kDa polypeptides were confirmed as EGF receptor and Shc, respectively. Calcipotriol-mediated EGF receptor dephosphorylation required the presence of extracellular calcium. Similar kinetics of the dephosphorylation was also observed in HaCaT cells cultured in medium of high calcium concentration. By BrdU labeling, we also showed calcium dependency of calcipotriol for the inhibition of cell proliferation. Therefore, EGF receptor deactivation by calcipotriol might be a mechanism of action for the inhibition of cell proliferation and the stimulation of differentiation in SCC13 cell and HaCaT cells.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Antineoplásicos/farmacología , Comunicación Autocrina/efectos de los fármacos , Calcitriol/farmacología , Carcinoma de Células Escamosas/metabolismo , Diferenciación Celular/efectos de los fármacos , Receptores ErbB/metabolismo , Apoptosis , Western Blotting , Bromodesoxiuridina , Calcitriol/análogos & derivados , Calcio/metabolismo , División Celular/efectos de los fármacos , Línea Celular , Colorantes Fluorescentes , Humanos , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Fosforilación/efectos de los fármacos , Antígeno Nuclear de Célula en Proliferación/metabolismo , Precursores de Proteínas/metabolismo , Proteínas/metabolismo , Proteínas Adaptadoras de la Señalización Shc , Transducción de Señal/efectos de los fármacos , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Sales de Tetrazolio , Tiazoles
17.
Br J Dermatol ; 133(2): 157-67, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7547380

RESUMEN

The family of protein kinase C (PKC) isoenzymes plays a fundamental part in signal transduction, and thereby regulates important cellular functions, including growth, differentiation, cytokine production and adhesion molecule expression. In lesional psoriatic skin, Ca(2+)-dependent PKC activity, PKC-beta protein and epidermal Langerhans cell (LC) PKC-beta immunostaining are significantly decreased, indicating activation and subsequent down-regulation of PKC. Whether these changes occur in other inflammatory/hyperplastic dermatoses is, however, unknown. We examined PKC-alpha and PKC-beta expression in normal skin, psoriasis, cutaneous T-cell lymphoma (CTCL), lamellar ichthyosis, non-bullous ichthyosiform erythroderma, atopic dermatitis, urushiol-induced allergic contact dermatitis, and sodium lauryl sulphate (SLS)-induced irritant contact dermatitis. Cryostat sections were stained for PKC-alpha and PKC-beta, and the LC marker CD1a, using an immunoperoxidase technique and specific monoclonal antibodies. Double-labelling studies, in normal skin, revealed co-expression of PKC-beta and CD1a by epidermal LCs. Analysis of the number of PKC-beta+ and CD1a+ epidermal LCs, in diseased compared with normal skin, revealed three categories: (i) in psoriasis and CTCL, the PKC-beta+ epidermal LC number was significantly reduced, whereas the CD1a+ epidermal LC number was unchanged; (ii) in allergic and irritant contact dermatitis, both PKC-beta+ and CD1a+ epidermal LCs were significantly reduced in number; and (iii) in atopic dermatitis, the PKC-beta+ epidermal LC number was normal, and CD1a+ epidermal LCs were significantly increased in number. Moreover, the ratio of epidermal LC PKC+/CD1a+ was reduced in all the dermatoses studied, suggesting activation of PKC-beta, with subsequent down-regulation. Within the dermis, increased PKC-beta staining of infiltrating cells was observed in all the conditions studied except lamellar ichthyosis and non-bullous ichthyosiform erythroderma. These data indicate that: (i) down-regulation of LC PKC-beta occurs in a variety of inflammatory and hyperplastic skin disorders, and is not unique to psoriasis, and (ii) the pattern of epidermal LC PKC-beta and CD1a expression varies among the diseases studied. In mice, PKC activation induces LC migration. Thus, down-regulation of epidermal LC PKC-beta associated with reduced CD1a+ epidermal LCs in allergic and irritant contact dermatitis suggests that PKC-beta may transduce the signal for migration of LCs from human epidermis.


Asunto(s)
Isoenzimas/metabolismo , Células de Langerhans/enzimología , Proteína Quinasa C/metabolismo , Enfermedades de la Piel/enzimología , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD1/análisis , Dermatitis Atópica/enzimología , Dermatitis por Contacto/enzimología , Regulación hacia Abajo , Femenino , Humanos , Ictiosis Lamelar/enzimología , Técnicas para Inmunoenzimas , Células de Langerhans/inmunología , Linfoma Cutáneo de Células T/enzimología , Masculino , Persona de Mediana Edad , Psoriasis/enzimología , Enfermedades de la Piel/inmunología , Neoplasias Cutáneas/enzimología
18.
Acta Derm Venereol ; 77(3): 194-7, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9188869

RESUMEN

The characteristics rash of herpes zoster begins as erythematous macules and papules, progressing to vesicles within 12-24 h. Patients with persistent papules without vesicular change are occasionally found. Our aim was to elucidate differences in vesicular and papular types of herpes zoster. Biopsy specimens from 21 patients were examined by an in situ hybridization method to observe viral distribution, and lymphocytic immunophenotypes were evaluated immunohistochemically. There was no differences in cell-mediated immunity or immunophenotypes in lymphocytic infiltrates between vesicular and papular types of herpes zoster. DNA of varicella-zoster virus was detected in the epidermis and hair follicles in the vesicular type but was found in the pilosebaceous unit in the papular type. This indicates that the appearance of clinical types of herpes zoster depends on the infected site of varicella-zoster virus in the tissue.


Asunto(s)
ADN Viral/análisis , Herpes Zóster/virología , Herpesvirus Humano 3/genética , Adolescente , Adulto , Anciano , Femenino , Herpes Zóster/inmunología , Herpes Zóster/patología , Humanos , Inmunofenotipificación , Hibridación Fluorescente in Situ , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/inmunología
19.
Pediatr Dermatol ; 13(2): 146-7, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-9122074

RESUMEN

Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before.


Asunto(s)
Dermatosis de la Mano/patología , Xantogranuloma Juvenil/patología , Núcleo Celular/ultraestructura , Niño , Eosinófilos/patología , Femenino , Células Espumosas/patología , Estudios de Seguimiento , Células Gigantes/patología , Humanos , Linfocitos/patología , Macrófagos/patología
20.
J Am Acad Dermatol ; 42(6): 1033-40, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10827410

RESUMEN

BACKGROUND: Several clinical studies have focused on the therapeutic effects of interferon gamma (IFN-gamma) in patients with severe atopic dermatitis (AD), although the dosage of recombinant IFN-gamma (rIFN-gamma), therapeutic schedule, and the degree of clinical improvement were different among studies. Although the exact mechanism of action of IFN-gamma therapy in AD is not clear, the beneficial effects of IFN-gamma have been attributed mainly to an immunomodulating effect on the expression of certain immunologic markers. OBJECTIVE: Our purpose was to study the therapeutic effect of two different dosages of rIFN-gamma on AD and to investigate the change of lesional expression of infiltrating inflammatory cell markers associated with rIFN-gamma therapeutic efficacy. METHODS: Fifty-one patients with severe recalcitrant AD were treated with rIFN-gamma. Twenty patients were treated with 0.5 x 10(6) IU/m(2) of rIFN-gamma (low-dose [LD] group); 21 patients received 1.5 x 10(6) IU/m(2) of rIFN-gamma (high-dose [HD] group); and 10 patients received placebo. The patients were injected subcutaneously 3 times a week for 12 weeks. Immunohistochemical study was performed in 20 patients of the HD group in the initial visit and after completion of rIFN-gamma therapy with a panel of 14 monoclonal antibodies as markers of inflammatory cells and cytokines. RESULTS: The disease severity of the 2 groups treated with rIFN-gamma was reduced significantly at the end of treatment compared with that of the placebo group (P<.05). More rapid clinical improvement and more effective treatment outcome were seen in the HD group than in the LD group for the initial 6-week treatment period; however, the clinical improvement in both of the treated groups was stable and maintained after week 8 of treatment. Immunohistochemical findings showed statistically significant reduction in the lesional expression of CD25 and EG2 cells that infiltrated into skin after rIFN-gamma therapy. CONCLUSION: This study demonstrated that rIFN-gamma therapy for AD is safe and effective. In the early phase of therapy, a higher dosage of rIFN-gamma is more effective; and for the maintenance of clinical improvement, a lower dosage of rIFN-gamma is recommended when high cost and effectiveness of rIFN-gamma are considered. The therapeutic efficacy of rIFN-gamma in AD might be in part related to the decreased number of CD25(+) and EG2(+) inflammatory cells infiltrated into skin.


Asunto(s)
Antineoplásicos/uso terapéutico , Dermatitis Atópica/tratamiento farmacológico , Interferón gamma/uso terapéutico , Adolescente , Adulto , Antineoplásicos/administración & dosificación , Biomarcadores/análisis , Análisis Costo-Beneficio , Citocinas/análisis , Dermatitis Atópica/inmunología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Inmunohistoquímica , Interferón gamma/administración & dosificación , Linfocitos/inmunología , Masculino , Receptores de Interleucina-2/análisis , Resultado del Tratamiento
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