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1.
J Neonatal Perinatal Med ; 16(2): 221-226, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37092238

RESUMEN

BACKGROUND: A few studies have been reported on the influence of fetal hiccups on umbilical artery. The aim of this study is to clarify the influence of fetal hiccups on Doppler blood flow waveform (DBFW) of some fetal arteries, and to show the difference in these influences among fetal arteries. OBJECTIVE: DBFW of umbilical artery, descending aorta, and middle cerebral artery were recorded at hiccups in normal fetuses between 34th and 40th gestational weeks. The changes on DBFW were classified into three shapes by the direction and the size of the changes. Shape 1: sharp decrease but not to the baseline, Shape 2: sharp decrease to the baseline (absence), and Shape 3: reverse flow. RESULTS: At all hiccups, the changes on DBFW of these arteries were observed. These changes were classified into three shapes. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of the descending aorta and middle cerebral artery were Shape 3 whenever the hiccup occurred during cardiac cycle. CONCLUSION: The changes on DBFW of fetal arteries were observed at all hiccups. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of descending aorta and middle cerebral artery were Shape 3. This is the first study clarified the influence of fetal hiccups on DBFW of some fetal arteries, and showed the difference in these influences among fetal arteries.


Asunto(s)
Hipo , Femenino , Embarazo , Humanos , Velocidad del Flujo Sanguíneo , Ultrasonografía Prenatal , Feto/diagnóstico por imagen , Feto/fisiología , Arteria Cerebral Media/diagnóstico por imagen , Arterias Umbilicales/diagnóstico por imagen , Arterias Umbilicales/fisiología
2.
Skin Res Technol ; 22(3): 318-24, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26725774

RESUMEN

BACKGROUND: Facial skin pigmentation is one of the most prominent visible features of skin aging and often affects perception of health and beauty. To date, facial pigmentation has been evaluated using various image analysis methods developed for the cosmetic and esthetic fields. However, existing methods cannot provide precise information on pigmented spots, such as variations in size, color shade, and distribution pattern. The purpose of this study is the development of image evaluation methods to analyze individual pigmented spots and acquire detailed information on their age-related changes. METHODS: To characterize the individual pigmented spots within a cheek image, we established a simple object-counting algorithm. First, we captured cheek images using an original imaging system equipped with an illumination unit and a high-resolution digital camera. The acquired images were converted into melanin concentration images using compensation formulae. Next, the melanin images were converted into binary images. The binary images were then subjected to noise reduction. Finally, we calculated parameters such as the melanin concentration, quantity, and size of individual pigmented spots using a connected-components labeling algorithm, which assigns a unique label to each separate group of connected pixels. RESULTS: The cheek image analysis was evaluated on 643 female Japanese subjects. We confirmed that the proposed method was sufficiently sensitive to measure the melanin concentration, and the numbers and sizes of individual pigmented spots through manual evaluation of the cheek images. The image analysis results for the 643 Japanese women indicated clear relationships between age and the changes in the pigmented spots. CONCLUSION: We developed a new quantitative evaluation method for individual pigmented spots in facial skin. This method facilitates the analysis of the characteristics of various pigmented facial spots and is directly applicable to the fields of dermatology, pharmacology, and esthetic cosmetology.


Asunto(s)
Colorimetría/instrumentación , Dermoscopía/instrumentación , Envejecimiento de la Piel/patología , Envejecimiento de la Piel/fisiología , Pigmentación de la Piel/fisiología , Piel/patología , Adulto , Anciano , Anciano de 80 o más Años , Mejilla/anatomía & histología , Mejilla/fisiología , Colorimetría/métodos , Dermoscopía/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Interpretación de Imagen Asistida por Computador/instrumentación , Interpretación de Imagen Asistida por Computador/métodos , Iluminación/instrumentación , Iluminación/métodos , Masculino , Persona de Mediana Edad , Fotograbar/instrumentación , Fotograbar/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Técnica de Sustracción/instrumentación , Adulto Joven
3.
Insect Mol Biol ; 20(3): 409-15, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21435062

RESUMEN

Mammalian-type CRYPTOCHROME (CRY-m) is considered to be a core repressive component of the circadian clock in various insect species. However, this role is based only on the molecular function of CRY-m in cultured cells and it therefore remains unknown whether CRY-m is indispensable for governing physiological rhythms at the organismal level. In the present study, we show that RNA interference (RNAi) targeting of cry-m in the bean bug Riptortus pedestris disrupts the circadian clock governing the cuticle deposition rhythm and results in the generation of a single cuticle layer. Furthermore, period expression was induced in cry-m RNAi insects. These results verified that CRY-m functions as a negative regulator in the circadian clock that generates physiological rhythm at the organismal level.


Asunto(s)
Relojes Circadianos , Ritmo Circadiano , Criptocromos/fisiología , Heterópteros/fisiología , Proteínas Circadianas Period/fisiología , Animales , Criptocromos/genética , Silenciador del Gen , Heterópteros/genética , Proteínas de Insectos/fisiología , Proteínas Circadianas Period/genética , Interferencia de ARN
4.
Heredity (Edinb) ; 87(Pt 4): 392-9, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11737286

RESUMEN

In Drosophila elegans, partial sexual isolation has developed between the brown and black morphs, which are distributed allopatrically. The present study aims to understand how they discriminate between potential mates. Mating experiments show that the females of the two morphs differ in sexual signal(s) and the males discriminate using these differences. Body colouration is not used as a sexual cue in this species. Between the females of the two morphs, a large difference was observed in the percentages of 7-pentacosene and 9-pentacosene on the cuticle. Genetical analysis using recombinant inbred lines supported the possibility that the concentration of these pentacosenes plays a role in mate discrimination of these two morphs. However, males did not respond to killed females at all, suggesting that cuticular hydrocarbons of females are not the only cue for the induction of male courtship behaviour. It may be that unknown signals or substances are essential to induce male courtship and pentacosenes modulate the attractiveness of females, positively in the black morph and negatively in the brown morph. Drosophila elegans F1 offspring had intermediate characteristics in mate discrimination and hydrocarbon composition between the parental brown and black morph strains. The number of loci responsible for the differences in the concentration of pentacosenes and the male and female components in the mate recognition between these two morphs is suggested to be more than one.


Asunto(s)
Drosophila/química , Drosophila/fisiología , Hidrocarburos/análisis , Caracteres Sexuales , Conducta Sexual Animal , Animales , Cromatografía de Gases , Cruzamientos Genéticos , Señales (Psicología) , Drosophila/anatomía & histología , Drosophila/genética , Femenino , Hidrocarburos/química , Hidrocarburos/metabolismo , Masculino , Atractivos Sexuales/análisis , Atractivos Sexuales/química , Atractivos Sexuales/metabolismo , Especificidad de la Especie
5.
Eur J Biochem ; 268(18): 4892-8, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11559358

RESUMEN

Using an anti-(glutathione S-transferase-UVS.2 cDNA) Ig and uterine egg vitelline envelope (UEVE) protein of Xenopus laevis as probes, the hatching enzyme (HE) from Xenopus was solubilized in hatching medium and purified by gel-filtration and ion-exchange chromatography, and characterized in terms of its molecular mass and enzymatic properties. The hatching medium solubilized the UEVE and contained molecules reactive to the anti-(GST UVS.2) Ig against Xenopus HE. It was found that the HE had a molecular mass of 60 kDa, and often preparations also contained a 40-kDa form. The 60-kDa HE had a high hydrolytic and UEVE-solubilizing activity, and its activities against Boc-Leu-Gly-Arg-7-amino-4-methylcoumarin (-NH-Mec) and UEVE were inhibited by anti-(GST UVS.2) Ig in a dose-dependent manner. The 60-kDa form was easily autodigested into a 40-kDa form. The 40-kDa molecule alone had no detectable UEVE-solubilizing activity, even it still had high hydrolytic activity. It probably represents the main protease domain of the 60-kDa form after loss of two CUB repeats during autodigestion or digestion. The autodigestion of the 60-kDa molecule into 40-kDa molecule is probably a congenital behavior for successfully dissolving the embryo envelope during the hatching process. The two molecules may play different roles at different stages of the hatching process, during which they co-ordinate with each other to achieve complete solubilization of the embryo envelope, similar to the high and low choriolytic enzymes in medaka (Oryzias latipes). Their hydrolytic activity against Boc-Leu-Gly-Arg-NH-Mec was optimal at pH of 7.4, and with an apparent Km value of 200 micromol.L-1 at 30 degrees C. The HE is very sensitive to trypsin-specific inhibitors such as leupeptin, (4-amidino-phenyl)methane sulfonyl fluoride, diisopropyl fluorophosphate (DFP) and N-alpha-tosyl-L-lysylchloromethane (Tos-Lys-CH2Cl), indicates that it is a trypsin-type protease. The results on EDTA and some metal ions, combined with the occurrence of a astacin family metalloprotease-specific 'HExHxxGFxHE' sequence in the deduced HE amino-acid sequence, indicates that this HE is a Zn2+ metalloprotease.


Asunto(s)
Metaloendopeptidasas/química , Metaloendopeptidasas/metabolismo , Xenopus laevis , Animales , Western Blotting , Caseínas/metabolismo , Cationes Bivalentes/metabolismo , Cationes Bivalentes/farmacología , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Inhibidores Enzimáticos/farmacología , Femenino , Hidrólisis , Metaloendopeptidasas/antagonistas & inhibidores , Metaloendopeptidasas/aislamiento & purificación , Peso Molecular , Tinción con Nitrato de Plata , Solubilidad , Especificidad por Sustrato , Membrana Vitelina/metabolismo , Zinc/metabolismo , Zinc/farmacología
6.
J Obstet Gynaecol Res ; 27(3): 141-5, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11561830

RESUMEN

OBJECTIVE: To investigate the effects of tamoxifen on the uterine endometrium and define the indications for histological examination of endometrium on the thickness of uterine endometrium and on the duration of tamoxifen therapy. METHODS: The endometrial thickness was measured on the transvaginal ultrasonogram in 40 postmenopausal breast carcinoma patients receiving tamoxifen (tamoxifen group), and control group. Endometrial histological examination was carried out. Receiver operating characteristic (ROC) curve analysis was carried out. RESULTS: Endometrial thickness in the tamoxifen group was 11.2 +/- 5.1 mm, and that of the control group was 3.8 +/- 2.1 mm. The incidence of endometrial abnormalities in the tamoxifen group was greater than that in control group. The cut off values derived from the ROC curve analysis were 9 mm for endometrial thickness, and 24 months for duration of tamoxifen therapy. CONCLUSION: The histological examination of endometrium should be carried out if the endometrial thickness is more than 9 mm, or the duration of tamoxifen therapy is more than 24 months even if the patients do not have any symptoms.


Asunto(s)
Antineoplásicos Hormonales/efectos adversos , Neoplasias de la Mama/tratamiento farmacológico , Endometrio/diagnóstico por imagen , Tamoxifeno/efectos adversos , Antineoplásicos Hormonales/uso terapéutico , Biopsia , Hiperplasia Endometrial/diagnóstico por imagen , Hiperplasia Endometrial/patología , Neoplasias Endometriales/diagnóstico , Endometrio/patología , Femenino , Humanos , Pólipos/diagnóstico , Posmenopausia , Curva ROC , Tamoxifeno/uso terapéutico , Factores de Tiempo , Ultrasonografía
7.
J Obstet Gynaecol Res ; 27(1): 33-5, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11330728

RESUMEN

In the presence of severe hyperbilirubinemia in Crigler-Najjar syndrome Type II, a fetus is at risk for kernicterus. A 34-year-old woman, gravida 4, para 1, with Crigler-Najjar syndrome Type II was treated with phenobarbital administration following phototherapy during each of 2 pregnancies. Both infants were healthy and developed normally.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Síndrome de Crigler-Najjar/terapia , Fenobarbital/uso terapéutico , Fototerapia , Complicaciones del Embarazo/terapia , Adulto , Femenino , Humanos , Recién Nacido , Embarazo , Resultado del Embarazo
8.
Glycoconj J ; 18(4): 347-53, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11788803

RESUMEN

The binding of Shiga toxin (Stx) to Gb3Cer in detergent-insoluble microdomains (DIM)/raft of the ACHN human renal tubular cell line causes the temporal activation of the Src-family kinase Yes [1]. As a strategy for examining signaling mechanisms in DIM/raft, monoclonal antibodies (MAbs) are reliable tools for characterizing the constituent molecules in these microdomains. Thus, we employed DIM/raft suspensions of ACHN cells as an immunogen to develop MAbs. Simply subcutaneous injections of ACHN DIM/raft could elevate the serum titer after several boosts. The first screening was performed using dot-blot immunostaining with culture supernatants on a polyvinylidene difluoride (PVDF) membrane, on which DIM/raft or their chloroform/methanol (C/M) (2:1, v/v) extracts were dot-blotted. The next screening was performed by flowcytometric analysis of ACHN cells treated with or without a permeabilizing reagent. Many of the clones (21/31 clones=68%) thus obtained were also found to recognize to lipid fractions of the DIM/raft. Strikingly, all of the 21 clones that reacted to the lipid fraction were found to recognize monosialosyl galactosylgloboside (MSGG) or GL7, which carries the SSEA-4 epitope. Using DIM/raft as immunogens may enable us to easily obtain MAbs for glycolipids.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Epítopos/inmunología , Globósidos/inmunología , Glicoesfingolípidos/inmunología , Riñón/inmunología , Microdominios de Membrana/inmunología , Animales , Anticuerpos Monoclonales/biosíntesis , Antígenos/química , Antígenos/inmunología , Línea Celular , Centrifugación por Gradiente de Densidad , Cromatografía en Capa Delgada , Epítopos/química , Citometría de Flujo , Globósidos/química , Glicoesfingolípidos/química , Humanos , Hibridomas/inmunología , Immunoblotting , Riñón/citología , Microdominios de Membrana/química , Ratones , Solubilidad , Antígenos Embrionarios Específico de Estadio , Células Tumorales Cultivadas
10.
Zygote ; 8(4): 303-14, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11108552

RESUMEN

We reported previously that in mouse testis calmodulin-dependent protein phosphatase (calcineurin) is localised in the nuclei of round and elongating spermatids (Cell Tissue Res. 1995; 281: 273-81). In this study, we studied the immunohistochemical localisation of calcium/calmodulin-dependent protein kinase (CaM kinase II) using antibodies against CaM kinase IIgamma from chicken gizzard and specific antibodies raised against the amino acid sequence Ileu480-Ala493 of this enzyme, and compared it with the distribution of calmodulin. Indirect immunofluorescence was most concentrated in early spermatocytes and localised in the outermost layer of seminiferous tubules where the calmodulin level was relatively low. Measurements of immuno-gold particle densities on electron micrographs revealed that CaM kinase II is transiently increased in the nucleus of zygotene spermatocytes. These observations suggest the involvement of CaM kinase II in the meiotic chromosomal pairing process. An extremely high concentration of calmodulin in spermatogenic cells undergoing meiosis may not be directly related to activation of calmodulin-dependent kinases and phosphatases.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/análisis , Calmodulina/análisis , Testículo/enzimología , Animales , Western Blotting , Encéfalo/enzimología , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Núcleo Celular/enzimología , Núcleo Celular/ultraestructura , Pollos , Células Epiteliales/citología , Células Epiteliales/enzimología , Molleja de las Aves/enzimología , Inmunohistoquímica/métodos , Masculino , Ratones , Ratones Endogámicos ICR , Microscopía Inmunoelectrónica , Ratas , Túbulos Seminíferos/citología , Túbulos Seminíferos/enzimología , Células de Sertoli/enzimología , Células de Sertoli/ultraestructura , Testículo/citología
11.
Dev Growth Differ ; 42(5): 459-67, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11041487

RESUMEN

Ectoderm pieces explanted from embryos of Xenopus laevis were cultured and examined for differentiation of hatching gland cells, using immunoreactivity against anti-XHE (Xenopus hatching enzyme) as a marker. The anterio-dorsal ectoderm excised from stage 12-13 (mid-late gastrula) embryos developed hatching gland cells. Meanwhile, the posterio-, but not the anterio-dorsal ectoderm from stage 11 (early gastrula) embryos developed these cells, although it is not fated to do so during normogenesis. This hatching gland cell differentiation from stage 11 posterior ectoderm was not affected by conjugated sandwich culture with the mesoderm but was suppressed when explants contained an anterior portion of the ectoderm. Conjugated cultures of anterior and posterior portions of the ectoderm in various combinations indicated that differentiation of hatching gland cells from stage 11 posterior and stage 12 anterior portions was suppressed specifically by stage 11 anterior ectoderm. Northern blot analyses of cultured explants showed that XHE was expressed in association with XA-1, suggesting its dependence on the anteriorized state. These results indicate that the planar signal(s) emanating from stage 11 anterior ectoderm participates in suppression of the expression of the anteriorized phenotype so that an ordered differentiation along the anteroposterior axis of the surface ectoderm is accomplished.


Asunto(s)
Embrión no Mamífero/metabolismo , Animales , Northern Blotting , Embrión no Mamífero/anatomía & histología , Femenino , Metaloendopeptidasas/genética , Fenotipo , Xenopus laevis/embriología
12.
J Biol Chem ; 274(49): 35278-82, 1999 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-10575015

RESUMEN

Shiga toxin (Stx) is an enterotoxin produced by Shigella dysenteriae serotype 1 and enterohemorrhagic Escherichia coli, which binds specifically to globotriaosylceramide, Gb3, on the cell surface and causes cell death. We previously demonstrated that Stx induced apoptosis in human renal tubular cell line ACHN cells (Taguchi, T., Uchida, H., Kiyokawa, N., Mori, T., Sato, N., Horie, H., Takeda, T and Fujimoto, J. (1998) Kidney Int. 53, 1681-1688). To study the early signal transduction after Stx addition, Gb3-enriched microdomains were prepared from ACHN cells by sucrose density gradient centrifugation of Triton X-100 lysate as buoyant, detergent-insoluble microdomains (DIM). Gb3 was only recovered in DIM and was associated with Src family kinase Yes. Phosphorylation of tyrosine residues of proteins in the DIM fraction increased by 10 min and returned to the resting level by 30 min after the addition of Stx. Since the kinase activity of Yes changed with the same kinetics, Yes was thought to be responsible for the hyperphosphorylation observed in DIM proteins. Unexpectedly, however, all of the Yes kinase activity was obtained in the high density, detergent-soluble fraction. Yes was assumed to be activated and show increased Triton X-100 solubility in the early phase of retrograde endocytosis of Stx-Gb3 complex. Since Yes activation by the Stx addition was suppressed by filipin pretreatment, Gb3-enriched microdomains containing cholesterol were deeply involved in Stx signal transduction.


Asunto(s)
Toxinas Bacterianas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Trihexosilceramidas/metabolismo , Familia-src Quinasas , Animales , Antibacterianos/farmacología , Toxinas Bacterianas/farmacología , Línea Celular , Centrifugación por Gradiente de Densidad , Cromatografía en Capa Delgada , Detergentes/farmacología , Activación Enzimática/efectos de los fármacos , Filipina/farmacología , Humanos , Cinética , Ratones , Octoxinol/farmacología , Pruebas de Precipitina , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas c-yes , Ratas , Toxinas Shiga , Transducción de Señal , Factores de Tiempo
13.
Arch Dermatol Res ; 291(10): 560-3, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10552215

RESUMEN

The effects of four different magnesium salts on the cutaneous barrier recovery rate after barrier disruption were evaluated. We spread an aqueous solution of each salt on the flank skin of hairless mice, occluded the area with a plastic membrane for 20 min, and then left the skin surface to dry. All of the magnesium salts, except magnesium bis(dihydrogen phosphate), accelerated barrier repair. We next estimated the effects of magnesium chloride aqueous solutions which contained calcium chloride at different molar ratios. When the calcium to magnesium ratio was lower than 1, the mixture accelerated barrier repair. The application of an aqueous solution of 10 mM magnesium chloride and 10 mM calcium chloride was found to hasten the barrier recovery more effectively than a solution of 10 mM magnesium chloride. These results suggest that the effects of these metal ions are different depending on the counter ion and/or the method of application.


Asunto(s)
Cloruro de Calcio/farmacología , Magnesio/farmacología , Fenómenos Fisiológicos de la Piel/efectos de los fármacos , Animales , Ratones , Ratones Pelados , Concentración Osmolar , Sales (Química)/farmacología , Soluciones , Factores de Tiempo
14.
J Obstet Gynaecol Res ; 25(5): 303-7, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10533323

RESUMEN

This is the first report of placenta previa increta in which the placenta villi penetrated the entire thickness of the uterine myometrium, but did not invade the pubocervical fascia. Ultrasonographic and magnetic resonance imaging findings are described.


Asunto(s)
Imagen por Resonancia Magnética , Miometrio/patología , Placenta Previa/patología , Ultrasonografía Prenatal , Adulto , Cesárea , Femenino , Edad Gestacional , Humanos , Miometrio/diagnóstico por imagen , Placenta Previa/diagnóstico por imagen , Embarazo , Tocólisis
15.
Dev Genet ; 25(2): 123-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10440846

RESUMEN

Acquisition of fertilizability in Xenopus coelomic eggs is correlated with the conversion from coelomic to vitelline envelope during passage of the eggs through the pars recta portion of oviduct. The conversion includes processing of a major envelope constituent gp43 of coelomic envelopes to gp41 of vitelline envelopes by a trypsin-type protease, oviductin, which is secreted from the pars recta. Our recent sequencing analyses [Kubo et al., (1997): Dev Growth Diff 39:405-411] strongly suggested that the N-terminal portion of gp41 is exposed as a result of oviductin digestion. In this study, a monoclonal antibody specific to the predicted N-terminus of gp41 was raised by immunizing mice with a synthetic N-terminal hexapeptide (QLPVSP) coupled to keyhole limpet hemocyanin. The antibody specifically reacted to gp41, but not to gp43, indicating that Gln62 is exposed as the N-terminal amino acid of gp41 by oviductin-mediated cleavage of gp43 at Arg61 in GSR61. The C-terminal sequencing of gp43 and gp41 indicated that Arg373 in GSR373 as the C-terminus of gp41 is generated by cleavage of three amino acid (WNQ) residues from the C-terminus of gp43. The resulting polypeptide moiety of gp41 has a molecular mass of 33900 Da with 312 amino acid residues. We propose that oviductin possessing the substrate specificity of GSR simultaneously digests gp43 at Arg residues in GSR61 and GSR373 to generate the N- and C-terminus of gp41, respectively.


Asunto(s)
Proteínas del Huevo/metabolismo , Glicoproteínas/metabolismo , Glicoproteínas de Membrana/metabolismo , Óvulo/metabolismo , Receptores de Superficie Celular , Serina Endopeptidasas/metabolismo , Proteínas de Xenopus , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales , Sitios de Unión , Proteínas del Huevo/genética , Proteínas del Huevo/inmunología , Femenino , Glicoproteínas/genética , Glicoproteínas/inmunología , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Ratones , Procesamiento Proteico-Postraduccional , Xenopus laevis , Glicoproteínas de la Zona Pelúcida
16.
Dev Biol ; 210(2): 269-76, 1999 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10357890

RESUMEN

The acquisition of fertilizability in coelomic eggs of Xenopus laevis has been shown to be correlated with the physical, biochemical, and ultrastructural alterations of the egg envelope [coelomic envelope (CE)] induced during the passage of eggs through the pars recta portion of the oviduct. However, no direct evidence that the pars recta renders eggs fertilizable has yet been presented. In this study, we show that coelomic eggs are highly fertilizable when they are incubated with continuous shaking for 4 h at 15 degrees C in pars recta extract (PRE) derived from females prestimulated by pregnant mare serum gonadotropin. The PRE from pituitary-stimulated Bufo japonicus was as potent as homologous PRE in rendering Xenopus eggs fertilizable. Incubation of coelomic eggs in PRE for 30 min induced a dramatic increase in the rates of sperm binding to the envelope to a level equivalent to that exhibited by the envelope from uterine eggs (VEs). The CE-to-VE ultrastructural conversion and a 43k-to-41k hydrolysis of the envelope glycoprotein component started 5 min after, and were completed by 15 min after, the start of incubation in PRE and were accompanied by an exposure of a new N-terminal sequence typical to gp41. Thus, the biochemical and ultrastructural conversions and the sperm-binding activity of the envelope induced by PREs, although being prerequisite, were not sufficient to render coelomic eggs fully accessible to fertilizing sperm.


Asunto(s)
Fertilización/fisiología , Oocitos/fisiología , Oviductos/fisiología , Interacciones Espermatozoide-Óvulo , Espermatozoides/fisiología , Animales , Bufonidae , Gonadotropina Coriónica/farmacología , Femenino , Gonadotropinas Equinas/farmacología , Masculino , Oocitos/efectos de los fármacos , Oocitos/ultraestructura , Xenopus laevis
17.
J Invest Dermatol ; 112(3): 303-9, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10084306

RESUMEN

The epidermal permeability barrier of premature infants matures rapidly following birth. Previous studies suggest that air exposure could contribute to this acceleration, because: (i) development of a structurally and functionally mature barrier accelerates when fetal rat skin explants are incubated at an air-medium interface, and (ii) occlusion with a water-impermeable membrane prevents this acceleration. To investigate further the effects of air exposure on epidermal barrier ontogenesis, we compared the activities of several key enzymes of lipid metabolism and gene expression of protein markers of epidermal differentiation in fetal rat skin explants grown immersed versus air exposed. The rate-limiting enzymes of cholesterol (HMG CoA reductase) and ceramide (serine palmitoyl transferase) synthesis were not affected. In contrast, the normal developmental increases in activities of glucosylceramide synthase and cholesterol sulfotransferase, responsible for the synthesis of glucosylceramides and cholesterol sulfate, respectively, were accelerated further by air exposure. Additionally, two enzymes required for the final stages of barrier maturation and essential for normal stratum corneum function, beta-glucocerebrosidase, which converts glucosylceramide to ceramide, and steroid sulfatase, which desulfates cholesterol sulfate, also increased with air exposure. Furthermore, filaggrin and loricrin mRNA levels, and filaggrin, loricrin, and involucrin protein levels all increased with air exposure. Finally, occlusion with a water-impermeable membrane prevented both the air-exposure-induced increase in lipid enzyme activity, and the expression of loricrin, filaggrin, and involucrin. Thus, air exposure stimulates selected lipid metabolic enzymes and the gene expression of key structural proteins in fetal epidermis, providing a biochemical basis for air-induced acceleration of permeability barrier maturation in premature infants.


Asunto(s)
Aire , Enzimas/metabolismo , Epidermis/embriología , Metabolismo de los Lípidos , Proteínas/metabolismo , Aciltransferasas/metabolismo , Animales , Arilsulfatasas/metabolismo , Desarrollo Embrionario y Fetal/fisiología , Feto/metabolismo , Feto/fisiología , Glucosilceramidasa/metabolismo , Glucosiltransferasas/metabolismo , Hidroximetilglutaril-CoA Reductasas/metabolismo , Proteínas/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Serina C-Palmitoiltransferasa , Esteril-Sulfatasa , Sulfotransferasas/metabolismo
18.
Arch Biochem Biophys ; 361(1): 135-41, 1999 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-9882438

RESUMEN

We compare the physicochemical and functional characteristics of nucleoplasmin obtained from Xenopus laevis oocytes and by bacterial overexpression of a plasmid containing the nucleoplasmin gene. The comparison shows that, while the secondary structure of the protein is not affected by the method used to obtain this protein, the bacterial expressed form exhibits a marked tendency to form large aggregates and an impaired ability to displace protamines from sperm nuclei. These results add a word of caution to the indiscriminate use, in functional or structural (crystallographic) studies, of bacterially overproduced proteins that have been end-terminally tagged with polyhistidine.


Asunto(s)
Proteínas Nucleares/química , Proteínas Nucleares/genética , Oocitos/química , Fosfoproteínas/química , Fosfoproteínas/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Secuencia de Aminoácidos , Animales , Núcleo Celular/metabolismo , Cromatina/química , Cromatina/metabolismo , Dicroismo Circular , Escherichia coli/genética , Femenino , Peces , Masculino , Datos de Secuencia Molecular , Peso Molecular , Proteínas Nucleares/metabolismo , Nucleoplasminas , Fosfoproteínas/metabolismo , Proteínas Recombinantes/metabolismo , Espermatozoides/metabolismo , Ultracentrifugación , Xenopus laevis
19.
Can J Physiol Pharmacol ; 76(4): 395-400, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9795748

RESUMEN

Myotoxin a, a small basic polypeptide from prairie rattlesnakes (Crotalus viridis viridis), induces myonecrosis and binds to a single class of binding sites in skeletal muscle sarcoplasmic reticulum. In the present study, [125I]myotoxin a with a high specific activity was prepared and it was shown to bind mainly to microsomes in rat whole brain. [125I]Myotoxin a was further shown to bind to microsomes prepared from all regions tested in brain. Its specific binding to whole brain microsomes was of approximately 1.9 times lower affinity (KD = 0.76 microM; Bmax = 13.1 nmol/mg) than that to skeletal muscle sarcoplasmic reticulum. [125I]Myotoxin a binding to brain microsomes was displaced by unlabeled myotoxin a with an IC50 value of 4.5 microM. [125I]Myotoxin a binding was markedly reduced by treatment of microsomes with trypsin, suggesting that the binding site of [125I]myotoxin a is partially proteins. The binding was significantly inhibited by Mg2+ at concentrations above 1 mM. Having looked at several drugs, we noted that [125I]myotoxin a binding was noncompetitively inhibited by spermine, whereas it was enhanced by heparin. On the other hand, the i.c.v. injection of myotoxin a in mice induced potent convulsive effects at 0.05 nmol/mouse or more. This paper is the first to show that the specific binding site of myotoxin a is present in mouse brain and that myotoxin a is a novel peptidic convulsant in mice.


Asunto(s)
Encéfalo/metabolismo , Venenos de Crotálidos/metabolismo , Microsomas/metabolismo , Animales , Encéfalo/efectos de los fármacos , Venenos de Crotálidos/toxicidad , Inyecciones Intraventriculares , Masculino , Ratones , Microsomas/química , Ratas , Ratas Wistar
20.
Biochim Biophys Acta ; 1387(1-2): 153-64, 1998 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-9748549

RESUMEN

The culture medium in which prehatching embryos of the frog, Rana pirica, were cultured (hatching medium) solubilized the vitelline coat (VC) of unfertilized eggs and contained molecules reactive to antibodies (anti-UVS.2) against the Xenopus hatching enzyme (HE). The hydrolyzing activity of the hatching medium against Pro-Phe-Arg-MCA was inhibited dose-dependently by the same antibodies. Using anti-UVS.2 as a probe, we purified two distinct 56 kDa molecules exhibiting Pro-Phe-Arg-MCA hydrolyzing activity. These 56 kDa molecules, which were separable on anion exchange chromatography, were the same with respect to VC solubilizing activity and a substrate specificity for various MCA-peptides, and they were regarded as charge isomers that function as the HE. The hydrolyzing activity against Pro-Phe-Arg-MCA of HE was optimal at pH of 7.6, with the apparent Km value of 250 microM at 30 degreesC. The activity was strongly inhibited by DFP and EDTA, and was accelerated by extremely low concentrations of Mg2+ and Zn2+, indicating the serine protease and metalloprotease nature of the HE. The HE was glycosylated and was present as a putative proenzyme form of 63 kDa.


Asunto(s)
Embrión no Mamífero/enzimología , Metaloendopeptidasas/química , Ranidae/embriología , Animales , Anticuerpos/farmacología , Cationes Bivalentes/farmacología , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/química , Glicosilación , Concentración de Iones de Hidrógeno , Metaloendopeptidasas/inmunología , Oligopéptidos/metabolismo , Péptidos/metabolismo , Serina Endopeptidasas/química , Membrana Vitelina/metabolismo
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