RESUMEN
Nanotubes with a single monolayer membrane wall comprised of a synthetic glycolipid and one of two synthetic azobenzene derivatives were assembled. X-ray diffraction, infrared, UV-visible, and circular dichroism spectroscopy clarified the embedding style of the azobenzene derivatives in the membrane wall, revealing that, depending on their different intermolecular hydrogen bond strengths, one azobenzene derivative was individually dispersed whereas the other formed a J-type aggregate. The non-aggregated derivative was insensitive to UV irradiation due to tight fixation by the surrounding glycolipid. In contrast, the aggregated derivative was sensitive to UV irradiation, which induced trans-to-cis isomerization of the derivative and disassembly of the J-type aggregate. Subsequent dissociation of the derivative into the bulk solution resulted in the formation of many nanometer-scale holes in the membrane wall. Although a model protein encapsulated within the nanotubes was slowly released over time from the two open ends of the nanotubes without UV irradiation, exposure to UV irradiation resulted in faster, preferential release of the protein through the holes in the membrane wall. The present findings are expected to facilitate the development not only of efficient means of recovering guest compounds stored within nanotubes but also the development of novel stimuli-responsive capsules in biological and medical fields.
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The Ezo red fox (Vulpes vulpes schrencki), a subspecies endemic to Hokkaido island, Japan, is a known host species for the tapeworm Echinococcus multilocularis. To develop tools for molecular ecological studies, we isolated 28 microsatellite regions from the genome of Ezo red fox, and developed 18 polymorphic microsatellite markers. These markers were characterized using 7 individuals and 22 fecal samples of the Ezo red fox. The number of alleles for these markers ranged from 1 to 7, and the observed heterozygosity, estimated on the basis of the genotypes of 7 individuals, ranged from 0.29 to 1.00. All markers, except DvNok5, were in Hardy-Weinberg equilibrium (P > 0.05), and no linkage disequilibrium was detected among these loci, except between DvNok14 and DvNok28 (P = 0.01). Moreover, six microsatellite loci were successfully genotyped using feces-derived DNA from the Ezo red fox. The markers developed in our study might serve as a useful tool for molecular ecological studies of the Ezo red fox.
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Zorros/genética , Técnicas de Genotipaje/métodos , Repeticiones de Microsatélite , Animales , Heces/química , Marcadores Genéticos/genética , HeterocigotoRESUMEN
OBJECTIVE: To develop an augmented reality (AR) neuronavigation system with Web cameras and examine its clinical utility. METHODS: The utility of the system was evaluated in three patients with brain tumors. One patient had a glioblastoma and two patients had convexity meningiomas. Our navigation system comprised the open-source software 3D Slicer (Brigham and Women's Hospital, Boston, Massachusetts, USA), the infrared optical tracking sensor Polaris (Northern Digital Inc., Waterloo, Canada), and Web cameras. We prepared two different types of Web cameras: a handheld type and a headband type. Optical markers were attached to each Web camera. We used this system for skin incision planning before the operation, during craniotomy, and after dural incision. RESULTS: We were able to overlay these images in all cases. In Case 1, accuracy could not be evaluated because the tumor was not on the surface, though it was generally suitable for the outline of the external ear and the skin. In Cases 2 and 3, the augmented reality error was â¼2 to 3 mm. CONCLUSION: AR technology was examined with Web cameras in neurosurgical operations. Our results suggest that this technology is clinically useful in neurosurgical procedures, particularly for brain tumors close to the brain surface.
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Neuroimagen/métodos , Neuronavegación/métodos , Procedimientos Neuroquirúrgicos/métodos , Cirugía Asistida por Computador/métodos , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Estudios de Factibilidad , Femenino , Glioblastoma/patología , Glioblastoma/cirugía , Humanos , Meningioma/patología , Meningioma/cirugía , Persona de Mediana Edad , Neuroimagen/instrumentación , Neuronavegación/instrumentación , Procedimientos Neuroquirúrgicos/instrumentación , Cirugía Asistida por Computador/instrumentación , Resultado del TratamientoRESUMEN
BACKGROUND AND PURPOSE: Extracranial-intracranial (ECIC) bypass grafts have been assessed postoperatively by various neuroradiologic techniques. The aim of this prospective study was to evaluate postoperative changes in ECIC bypass graft by using superficial temporal artery duplex ultrasonography (STDU). Furthermore, this study assessed the ability of STDU to predict cerebrovascular reserve capacity (CVR). MATERIALS AND METHODS: Forty-five consecutive patients who underwent ECIC bypass procedure for atherosclerotic internal carotid artery occlusion were enrolled in this prospective study. All patients underwent single-photon emission CT and STDU preoperatively, 14 days after, 3 months after, 1 year after, and 2 years after ECIC bypass. RESULTS: The diameter and flow velocities of the ipsilateral superficial temporal artery (STA), and regional cerebral blood flow (rCBF) showed increase during the first 2 weeks and then remained stable, whereas CVR showed a constant improvement up to 2 years after surgery. The STA diameter and mean STA flow velocity correlated significantly with CVR at 1 year after surgery (r2 = 0.1232 and r2 = 0.08716, respectively; P < .05). A cutoff value of 1.8 mm STA diameter was determined as the most reliable value to predict CVR greater than 10% at 1 year after surgery. The positive predictive value was calculated as 96.6%, the negative predictive value as 43.8%, the sensitivity as 75.7%, the specificity as 87.5%, and the likelihood ratio as 6.056. CONCLUSIONS: ECIC bypass grafts can be assessed postoperatively in a noninvasive fashion with STDU. This technique provides information regarding patency as well as quantitative assessment of bypass function. Moreover, STDU is useful to predict CVR improvement.
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Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/cirugía , Revascularización Cerebral/métodos , Ecoencefalografía/métodos , Arterias Temporales/diagnóstico por imagen , Ultrasonografía Doppler Dúplex/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados Posoperatorios/métodos , Pronóstico , Arterias Temporales/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND: Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a rare multisystem disorder associated with plasma cell dyscrasia. There is increasing evidence that high-dose chemotherapy with autologous peripheral blood stem cell transplantation (Auto-PBSCT) is an efficacious treatment. OBJECTIVE: To elucidate the extent and time course of neurologic improvement after Auto-PBSCT in patients with POEMS syndrome. METHODS: Clinical and electrophysiologic findings in nine patients were reviewed. The median follow-up period was 20 months (range, 8 to 49 months). Serum levels of vascular endothelial growth factor (VEGF) were measured by ELISA. RESULTS: Serum VEGF levels rapidly decreased a month after Auto-PBSCT. Within 3 months, neurologic improvement began, and all the patients showed substantial neurologic recovery during the next 3 months. Particularly, three initially chairbound patients regained ability to walk at 6 months. Nerve conduction studies showed significant increases in conduction velocities and amplitudes within 6 months of treatment. At the end of follow-up periods, neuropathy was still improving, and no patients had recurrence of symptoms. CONCLUSION: Autologous peripheral blood stem cell transplantation results in obvious neurologic improvement within 6 months, presumably by extensive axonal regeneration and remyelination. This therapy could be considered as a first line treatment for patients with polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome with younger onset even if they are tetraplegic.
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Fuerza de la Mano/fisiología , Conducción Nerviosa/fisiología , Síndrome POEMS/terapia , Trasplante de Células Madre de Sangre Periférica/métodos , Potenciales de Acción/fisiología , Adulto , Terapia Combinada , Quimioterapia/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Nervio Mediano/fisiopatología , Persona de Mediana Edad , Síndrome POEMS/sangre , Síndrome POEMS/fisiopatología , Estudios Retrospectivos , Factores de Tiempo , Trasplante Autólogo , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/sangreRESUMEN
AIMS/HYPOTHESIS: Based on mouse study findings, pancreatic islet cells are supposed to lack basement membrane (BM) and interact directly with vascular endothelial BM. Until now, the BM composition of human islets has remained elusive. METHODS: Immunohistochemistry with specific monoclonal and polyclonal antibodies as well as electron microscopy were used to study BM organisation and composition in human adult islets. Isolated islet cells and function-blocking monoclonal antibodies and recombinant soluble Lutheran peptide were further used to study islet cell adhesion to laminin (Lm)-511. Short-term cultures of islets were used to study Lutheran and integrin distribution. RESULTS: Immunohistochemistry revealed a unique organisation for human Lm-511/521 as a peri-islet BM, which co-invaginated into islets with vessels, forming an outer endocrine BM of the intra-islet vascular channels, and was distinct from the vascular BM that additionally contained Lm-411/421. These findings were verified by electron microscopy. Lutheran glycoprotein, a receptor for the Lm alpha5 chain, was found prominently on endocrine cells, as identified by immunohistochemistry and RT-PCR, whereas alpha(3) and beta(1) integrins were more diffusely distributed. High Lutheran content was also found on endocrine cell membranes in short-term culture of human islets. The adhesion of dispersed beta cells to Lm-511 was inhibited equally effectively by antibodies to integrin and alpha(3) and beta(1) subunits, and by soluble Lutheran peptide. CONCLUSIONS/INTERPRETATION: The present results disclose a hitherto unrecognised BM organisation and adhesion mechanisms in human pancreatic islets as distinct from mouse islets.
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Membrana Basal/citología , Células Endoteliales/citología , Islotes Pancreáticos/irrigación sanguínea , Islotes Pancreáticos/citología , Adulto , Animales , Anticuerpos Monoclonales , Membrana Basal/metabolismo , Membrana Basal/ultraestructura , Biomarcadores/metabolismo , Adhesión Celular , Moléculas de Adhesión Celular/inmunología , Moléculas de Adhesión Celular/metabolismo , Sistema Endocrino/citología , Células Endoteliales/metabolismo , Células Endoteliales/ultraestructura , Humanos , Inmunohistoquímica , Islotes Pancreáticos/ultraestructura , Laminina/inmunología , Laminina/metabolismo , Sistema del Grupo Sanguíneo Lutheran , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Ratones , Microscopía Electrónica de Transmisión , Proteínas de Neoplasias/inmunología , Proteínas de Neoplasias/metabolismo , Receptores de Laminina/inmunología , Receptores de Laminina/metabolismoRESUMEN
Hypoglossal neurinomas usually manifest with hemiatrophy and weakness of the tongue. A rare case of intracranial hypoglossal neurinoma without preoperative hypoglossal nerve dysfunction and its operative view are presented. A 36-year-old female who presented with headaches and vertigo was admitted to our hospital. The neurological examination revealed bilateral papilledema and mild truncal ataxia, although weakness and atrophy of the tongue were not observed. Magnetic resonance and computed tomography images demonstrated a large foramen magnum tumor without enlargement of the hypoglossal canal. Total removal of the tumor was performed via a lateral suboccipital craniotomy and C1 partial laminectomy. During the operation, two trunks were observed for the hypoglossal nerve at the entrance of the hypoglossal canal. The tumor arose from the caudal trunk, while the intact rostral trunk entered the hypoglossal canal normally. The tumor only developed intracranially, and since the rostral trunk of the hypoglossal nerve was intact, the patient did not present with hypoglossal nerve palsy preoperatively.
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Neoplasias de los Nervios Craneales/patología , Neoplasias de los Nervios Craneales/cirugía , Neurilemoma/patología , Neurilemoma/cirugía , Neoplasias de la Base del Cráneo/patología , Neoplasias de la Base del Cráneo/cirugía , Adulto , Atlas Cervical/diagnóstico por imagen , Atlas Cervical/patología , Atlas Cervical/cirugía , Fosa Craneal Posterior/diagnóstico por imagen , Fosa Craneal Posterior/patología , Fosa Craneal Posterior/cirugía , Neoplasias de los Nervios Craneales/complicaciones , Craneotomía , Descompresión Quirúrgica , Femenino , Cefalea/etiología , Humanos , Nervio Hipogloso/patología , Nervio Hipogloso/fisiopatología , Nervio Hipogloso/cirugía , Enfermedades del Nervio Hipogloso/etiología , Enfermedades del Nervio Hipogloso/patología , Enfermedades del Nervio Hipogloso/fisiopatología , Laminectomía , Imagen por Resonancia Magnética , Neurilemoma/complicaciones , Procedimientos Neuroquirúrgicos , Hueso Occipital/diagnóstico por imagen , Hueso Occipital/patología , Hueso Occipital/cirugía , Neoplasias de la Base del Cráneo/complicaciones , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Vértigo/etiologíaRESUMEN
We have characterized a new allele of the protocadherin 15 gene (designatedPcdh15(av-6J)) that arose as a spontaneous, recessive mutation in the C57BL/6J inbred strain at Jackson Laboratory. Analysis revealed an inframe deletion in Pcdh15, which is predicted to result in partial deletion of cadherin domain (domain 9) in Pcdh15. Morphologic study revealed normal to moderately defective cochlear hair cell stereocilia in Pcdh15(av-6J) mutants at postnatal day 2 (P2). Stereocilia abnormalities were consistently present at P5 and P10. Degenerative changes including loss of inner and outer hair cells were seen at P20, with severe sensory cell loss in all cochlear turns occurring by P40. The hair cell phenotype observed in the 6J allele between P0 and P20 is the least severe phenotype yet observed in Pcdh15 alleles. However, young Pcdh15(av-6J) mice are unresponsive to auditory stimulation and show circling behavior indicative of vestibular dysfunction. Since these animals show severe functional deficits but have relatively mild stereocilia defects at a young age they may provide an appropriate model to test for a direct role of Pcdh15 in mechanotransduction.
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Cadherinas/genética , Sordera/genética , Mutación , Precursores de Proteínas/genética , Alelos , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas Relacionadas con las Cadherinas , Cadherinas/química , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Potenciales Evocados Auditivos del Tronco Encefálico , Exones/genética , Femenino , Células Ciliadas Auditivas/ultraestructura , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Rastreo , Datos de Secuencia Molecular , Fenotipo , Precursores de Proteínas/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de SecuenciaRESUMEN
Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome is a rare multisystem disorder. Overproduction of vascular endothelial growth factor (VEGF) by plasmocytoma could be responsible for the symptoms. The authors treated four patients with high-dose chemotherapy and autologous peripheral blood stem cell transplantation. Within 6 months, symptoms associated with rapid normalization of serum VEGF levels improved.
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Trasplante de Células Madre Hematopoyéticas/métodos , Melfalán/uso terapéutico , Agonistas Mieloablativos/uso terapéutico , Síndrome POEMS/terapia , Adulto , Anciano , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndrome POEMS/fisiopatología , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/etiología , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Plasmacitoma/complicaciones , Plasmacitoma/tratamiento farmacológico , Plasmacitoma/metabolismo , Trasplante Autólogo , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/sangre , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Genetic variation in humans probably plays a role in determining the range of individual susceptibility to age-related hearing loss (AHL), but no contributing loci have been identified because of the difficulties of dissecting complex traits in humans. This paper reports mapping of an AHL locus using a panel of consomic mice between C57BL/6J (B6) and MSM strains, which covered more than a half of chromosome sets. B6 strain exhibited AHL beginning at 10 months of age whereas MSM strain, derived from Japanese wild mice, had normal hearing throughout life. Individuals in the panel were examined with auditory brainstem response (ABR) at various months of age, revealing that one particular strain (B6-Chr17(MSM)) substituting the chromosome 17 with the MSM-derived one showed a prominent resistance, having still good hearing at 18 months of age. Subsequent mapping using 89 individuals in the cross between B6-Chr17(MSM) and B6 was performed, which showed a significant association of ABR thresholds with loci in the vicinity of D17Mit119. These results show a novel AHL-resistant locus, designated as Ahl3, on the chromosome 17.
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Cromosomas de los Mamíferos , Presbiacusia/genética , Factores de Edad , Animales , Umbral Auditivo , Mapeo Cromosómico , Células Ciliadas Auditivas Externas/ultraestructura , Ratones , Ratones Endogámicos C57BL , Presbiacusia/diagnóstico , Sitios de Carácter CuantitativoRESUMEN
Using nucleotide sequences of the mitochondrial DNA (mtDNA) cytochrome b and SRY genes, we examined the genetic status of two major groups of domestic cattle, the humpless taurine (Bos taurus) and humped zebu (B. indicus), using 10 cattle populations in Asia. Several sequence polymorphisms specific for each major group were found, although the frequency of these polymorphisms varied in each population. Six major mtDNA-SRY composite types were observed. The Mishima, Mongolian, Korean, Chinese Yellow and Sri Lanka cattle populations had a full match between the mtDNA and SRY sequences, specifically the taurine/taurine type or zebu/zebu type. A non-match type (zebu/taurine type) was found at a high frequency in the Bangladesh (83.4%) and Nepal populations (83.3%). Our results suggest that these non-match type populations developed from genetic hybridization of different strains. Also, the domestication history of modern Asian domestic cattle could be explained by male-mediated introgression. Additionally, our results suggest the occurrence of introgression of mtDNA from other Bibos or Poephagus species into native cattle populations. The existence of other mtDNA-SRY composite types, such as the Bali-zebu and yak-zebu types in Indonesia (85.7%) and Nepal (16.7%), respectively, suggests that genetic introgression also occurred from other genera into domestic cattle during the process of domestication.
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Bovinos/genética , ADN Mitocondrial/genética , Proteínas de Unión al ADN/genética , Proteínas Nucleares , Filogenia , Factores de Transcripción , Animales , Secuencia de Bases , Cartilla de ADN , Masculino , Reacción en Cadena de la Polimerasa , Proteína de la Región Y Determinante del SexoRESUMEN
Ghrelin, a gastric-derived peptide, has recently been identified as an endogenous natural ligand for the growth hormone (GH) secretagogue receptor. However, secretory characteristics of ghrelin are still obscure in ruminants. To investigate the diurnal rhythm in ghrelin secretion and its relationship to GH secretion, plasma ghrelin and GH concentrations were determined in Suffolk rams fed with a roughage diet once daily (Experiment 1). Abrupt increases (P<0.05) in plasma ghrelin occurred just before a meal-feeding compared with that at 1h before feeding, then rapidly fell with a minimum during the feeding. A pulsatile surge (P<0.01) in plasma GH concentrations, which seemed to follow a single surge in plasma ghrelin, was observed during the feeding. In Experiment 2, plasma ghrelin and GH were determined in sheep subjected to a pseudo-feeding of 2h to determine whether feed ingestion itself influences ghrelin and GH secretions. Compared with those at 1h before feeding, a tendency of increases (P<0.1) in plasma ghrelin and significant increases (P<0.05) in GH occurred just before and during a pseudo-feeding, respectively. Plasma ghrelin temporally declined within 1h after the start of the pseudo-feeding, and increased again and maintained higher levels during the last period of the pseudo-feeding. These results suggest that the transient surge of ghrelin secretion just before a scheduled meal feeding would not be due to the ingestion of feed, and that a pulsatile increase in plasma GH during the actual- or pseudo-feeding could be induced by the transient ghrelin surge.
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Ingestión de Alimentos , Hormonas Peptídicas , Péptidos/sangre , Animales , Ritmo Circadiano , Técnica del Anticuerpo Fluorescente , Ghrelina , Hormona del Crecimiento/sangre , Masculino , OvinosRESUMEN
Regime transitions of poly[(S)-lactide] (PLA) crystal growth from the melt were investigated by studying the morphological changes and carrying out kinetic analysis using microscopic techniques. PLA thin films with an average layer thickness of 100 nm were isothermally crystallized at a given crystallization temperature after melting at 220 degrees C. Following isothermal crystallization at a temperature below 145 degrees C, uniform two-dimensional spherulites having stacked flat-on lamellar texture were developed throughout the PLA thin films. On the basis of electron diffraction analysis for two-dimensional spherulites of PLA, it was found that the average growth direction of an individual lamellar crystal was parallel to the crystallographic b axis. At temperatures above 150 degrees C, hexagonal lamellar crystals were formed from the melt. Electron diffractograms of these lamellae showed that the crystal had orthogonal packing of PLA molecules and a truncated-lozenge-shaped growth behavior. The growth surfaces of the hexagonal crystal were parallel to either the crystallographic (110) or the (100) plane. The PLA crystal growth rate along the b axis direction was evaluated at various crystallization temperatures of the thin films. Kinetic analysis of crystal growth in the PLA thin film demonstrated that the regime transitions of PLA crystal growth, from regime III to regime II and from regime II to regime I, occur at around 120 and 147 degrees C, respectively. The transition from regime II to regime I induced morphological changes in the crystalline aggregates whereby spherulitic aggregates transformed into hexagonal lamellar stacking. As for the transition between regimes II and III, no obvious morphological change in the spherulitic crystal aggregates was observed.
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Poliésteres/química , Materiales Biocompatibles/química , Biodegradación Ambiental , Cristalización , Cinética , Sustancias Macromoleculares , Microscopía de Fuerza Atómica , Microscopía Electrónica , Estructura Molecular , TemperaturaRESUMEN
The crystallization behavior and crystalline morphologies of poly[(S)-lactide] (P[(S)-LA]) in thin films crystallized isothermally at over 160 degrees C were characterized by transmission electron microscopy and atomic force microscopy (AFM). The dendritic crystal and hexagonal crystal were formed in thin film with thicknesses below 30 nm or over 50 nm, respectively. The crystal structures of dendritic and hexagonal crystals were identical, suggesting that the crystalline morphology of P[(S)-LA] is strongly dependent upon the film thickness. In situ observation of the crystal growth in the P[(S)-LA] thin film at 165 degrees C from the melt was carried out by using temperature-controlled AFM equipped with a heating stage. The initial stage of crystallization and development of lamellae were successfully observed during isothermal crystallization at 165 degrees C. The first forming crystal showed the edge-on orientation, and grew to S-shaped edge-on lamellae. Dendritic flat-on crystals were developed from the S-shaped edge-on lamellae. The growth rates of flat-on and edge-on lamellae were almost identical.
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Poliésteres/aislamiento & purificación , Materiales Biocompatibles/química , Materiales Biocompatibles/aislamiento & purificación , Cristalización , Microscopía de Fuerza Atómica , Microscopía Electrónica , Poliésteres/química , TemperaturaRESUMEN
A novel mouse model for human nonsyndromic hearing loss, Waltzer niigata (v(ngt)), is found and subjected to positional cloning analysis. Genome-wide scan of 1648 backcross mice maps v(ngt) to the D10Mit258 locus near Waltzer (v). Recombination breakpoints are positioned on a physical map consisting of 13 BACs relative to the flanking markers in the vicinity of v(ngt). Allelism test done in parallel shows that v(ngt) and v are allelic. Sequence analysis reveals one-base deletion in the cDNA encoding a cadherin-related protein, Cdh23, mutation of which is recently reported in v mutants. The frame-shift change, producing a truncated protein of 51 amino acids, is ascribed to a base-substitution of G to A in the acceptor site of splicing junction which is predicted to cause one-base shift of the splicing position.
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Cadherinas/genética , Mapeo Cromosómico , Sordera/genética , Ratones Mutantes Neurológicos/genética , Mutación Puntual , Animales , Conducta Animal , Cadherinas/metabolismo , Cilios/metabolismo , Cilios/patología , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Etiquetas de Secuencia Expresada , Marcadores Genéticos , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/patología , Homocigoto , Endogamia , Ratones , Ratones Endogámicos ICR , Fenotipo , ARN Mensajero/metabolismo , Recombinación GenéticaRESUMEN
Recently identified laminin isoforms containing the alpha4 chain have been shown to be expressed in the basement membrane of restricted organs such as heart, skeletal muscle, and blood vessels, especially those in embryos. We screened 38 human cell lines for the expression of the laminin alpha4 chain by reverse transcriptase-polymerase chain reaction and found that T98G glioblastoma cells express only alpha4, but not other alpha chains. Laminin-8, an isoform containing the alpha4 and beta1 chains, was purified from conditioned medium of T98G cells by gel filtration and immunoaffinity chromatography using a monoclonal antibody against laminin beta1 chain. The purified laminin isoform was composed of disulfide-linked 230-, 220-, and 200-kDa subunits, which immunoblot analysis identified as the beta1, gamma1, and alpha4 chains. Purified laminin-8 had cell adhesive activity comparable to laminin-1 but significantly weaker than laminin-5 and laminin-10/11. T98G cells adhering to laminin-8 became more elongated than those adhering to other laminin isoforms and extended multiple pseudopods. Cell adhesion to laminin-8 was abolished by an antibody against the integrin beta1 subunit or a combination of antibodies against the integrin alpha3 and alpha6 subunits, but not by either anti-alpha3 or anti-alpha6 antibody alone, suggesting that both alpha3beta1 and alpha6beta1 integrins serve as adhesion receptors for laminin-8. Consistent with these observations, K562 erythroleukemic cells transfected with either integrin alpha3 or alpha6 cDNA were capable of adhering to laminin-8 when beta1 integrins were stimulated by the beta1-activating antibody 8A2. Despite its moderate cell adhesive activity, laminin-8 was significantly potent in promoting cell migration when compared with other laminin isoforms and fibronectin. Cell migration on laminin-8 was completely inhibited by a combination of antibodies against alpha3 and alpha6 integrins, and substantially inhibited by anti-alpha3 antibody alone, suggesting that laminin-8-mediated cell migration is predominantly mediated by alpha3beta1 integrin. Given its potency to stimulate cell migration and preferential localization to the basement membrane of capillaries and embryonic tissues, laminin-8 may play a role in processes requiring enhanced cell migration during development, wound healing, and angiogenesis.
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Adhesión Celular/fisiología , Integrinas/fisiología , Laminina/fisiología , Anticuerpos Monoclonales/farmacología , Antígenos CD/inmunología , Antígenos CD/fisiología , Línea Celular , Movimiento Celular/fisiología , Cromatografía de Afinidad , Cromatografía en Gel , Medios de Cultivo Condicionados , Glioblastoma , Humanos , Integrina alfa3 , Integrina alfa3beta1 , Integrina alfa6 , Integrina alfa6beta1 , Integrinas/inmunología , Células K562 , Laminina/química , Laminina/genética , Laminina/aislamiento & purificación , Isoformas de Proteínas/aislamiento & purificación , Isoformas de Proteínas/fisiología , Subunidades de Proteína , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales CultivadasRESUMEN
A mouse gene, Gsl5, controls the expression of Galbeta1-4(Fucalpha1-3)GlcNAcbeta1-6(Galbeta1-3)Gb4Cer and its precursor glycolipids in the kidney by regulating transcription of beta-1,6-GlcNAc transferase. Here we report that Gsl5 controls the expression of the core 2 structure [GlcNAcbeta1-6(Galbeta1-3)GalNAcalpha1-Ser/Thr] of glycoproteins as well as the glycolipid, GlcNAcbeta1-6(Galbeta1-3)GalNAcbeta1-3Galalpha1-4Galbeta1-4Glcbeta1-ceramide. Immunohistochemical studies using an anti-(core 2-Lex) monoclonal antibody demonstrated that lysosome-like vesicles of proximal tubule cells were clearly stained in a Gsl5 wild type mouse, but not in a Gsl5 mutant strain of mice. Western blotting of microsomal fractions of kidney tissue with the same antibody confirmed the histological findings. In situ hybridization with an antisense probe to the kidney-specific mRNA demonstrated that the mRNA is localized at proximal tubule-cells in the cortex adjacent to the medulla, but not detected in glomeruli nor in collecting duct cells in the medulla. The results obtained by immunohistological staining and in situ hybridyzation are compatible and lead to the conclusion that the kidney specific mRNA is expressed in a proximal tubular cell specific manner and produces core 2 GlcNAc transferase responsible for the production of glycoproteins localized at vesicles in the proximal tubular cells. Glycosylation regulated by Gsl5 gene may modify functions of membrane glycoproteins in proximal tubular cells.
Asunto(s)
Glicoproteínas/metabolismo , Túbulos Renales Proximales/enzimología , N-Acetilglucosaminiltransferasas/genética , Factores de Transcripción/fisiología , Animales , Western Blotting , Secuencia de Carbohidratos , Células Epiteliales/enzimología , Glucolípidos/metabolismo , Hibridación in Situ , Antígeno Lewis X/inmunología , Antígeno Lewis X/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos DBA , Ratones Mutantes , Microsomas/metabolismo , Modelos Químicos , Datos de Secuencia Molecular , N-Acetilglucosaminiltransferasas/metabolismo , ARN Mensajero/análisis , Factores de Transcripción/genética , Transcripción GenéticaRESUMEN
We report a rare case of hypereosinophilic syndrome (HES) that developed to acute myeloblastic leukemia (AML). The patient, a 34-year-old man, presented with eosinophilia of unknown origin (white blood cells 38,200/microliter with 74% eosinophils) and pericardial effusion, and was diagnosed as having HES with a normal karyotype. He received four cycles of combination chemotherapy including cyclophosphamide, cytosine arabinoside and vindesine, and thereafter remained in remission. After 12 years, he was referred to our hospital because of fever and malaise. On admission, CBC showed white blood cells 3,000/microliter with 70% myeloblasts and 3% eosinophils. The bone marrow was hypercellular with 95% blasts, which were negative for myeloperoxidase (MPO) staining. Immunophenotype analysis revealed that the cells were positive for CD13, CD19, CD34, HLA-DR and cytoplasmic MPO. CD19-positive AML was diagnosed. Cytogenetic analysis showed 46, XY, t(6;21)(q13;q22), add(7)(q11) in 19 of 20 metaphase spreads. Rearrangement of the AML1 gene at 21q22 and fusion of the BCR/ABL gene could not be detected by fluorescence in situ hybridization analysis. The patient received combination chemotherapy and achieved a complete remission. Chromosome aberrations involving 7q as well as 21q22 suggested that the initial chemotherapy for HES might have been implicated in the pathogenesis of acute leukemia in this case.