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4.
Int J STD AIDS ; 23(8): 603-5, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22930304

RESUMEN

A 33-year-old man who developed progressive multifocal leukoencephalopathy (PML) with HIV infection is reported. The patient exhibited rapid decline in neurological status after initiation of antiretroviral therapy (ART), which was attributed to the PML-immune re-constitution inflammatory syndrome. Following the administration of mefloquine in combination with ART, the patient's neurological status improved substantially. This case suggests that further investigation of the use of mefloquine might be warranted for treatment of PML in HIV-infected patients.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Fármacos Anti-VIH/uso terapéutico , Antivirales/uso terapéutico , Leucoencefalopatía Multifocal Progresiva/tratamiento farmacológico , Mefloquina/uso terapéutico , Adulto , Fármacos Anti-VIH/administración & dosificación , Antivirales/administración & dosificación , Encéfalo/patología , Encéfalo/virología , Humanos , Virus JC/efectos de los fármacos , Leucoencefalopatía Multifocal Progresiva/patología , Imagen por Resonancia Magnética , Masculino , Mefloquina/administración & dosificación , Neuroimagen
5.
Br J Dermatol ; 153 Suppl 2: 37-46, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16280020

RESUMEN

BACKGROUND: The epidermal basement membrane (BM) plays important roles in adhesion between epidermis and dermis, and in controlling epidermal differentiation. The BM has been reported to be damaged in sun-exposed skin. Although matrix metalloproteinases (MMPs) are believed to be involved in the BM damage, there is no good in vitro model for examining BM damage by MMPs or for exploring methods to protect the BM. OBJECTIVES: To examine the involvement of MMPs in BM damage and approaches to protect the BM from such damage by using an in vitro skin-equivalent (SE) model. METHOD: SE was prepared by culturing human keratinocytes on contracted collagen gel including human fibroblasts. MMP-1, -2, -3 and -9, laminin 5 and type IV and VII collagens were determined by specific sandwich ELISAs, and MMP-2 and MMP-9 were analysed by gelatin zymography. Histological examination of SE was also carried out. RESULTS: Despite production of BM components such as laminin 5 and type IV and VII collagens in SEs, BM was rarely observed at the dermal-epidermal junction. Several MMPs, such as MMP-1, -2, -3 and -9, were observed to be present in conditioned media and some of them were in active forms. Tissue inhibitor of metalloproteinase (TIMP)-2 was not detected, although TIMP-1 was present. Synthetic MMP inhibitors, CGS27023A and MMP-inhibitor I, which inhibit MMP-1, -2, -3 and -9, markedly augmented deposition of laminin 5 and type IV and VII collagens at the dermal-epidermal junction, resulting in the formation of continuous epidermal BM. CONCLUSIONS: Our results indicate that MMPs are involved in the degradation of BM in SEs, and that MMP inhibitors exert a protective effect against BM damage.


Asunto(s)
Membrana Basal/efectos de la radiación , Epidermis/ultraestructura , Ácidos Hidroxámicos/farmacología , Oligopéptidos/farmacología , Inhibidores de Proteasas/farmacología , Pirazinas/farmacología , Envejecimiento de la Piel , Rayos Ultravioleta/efectos adversos , Membrana Basal/efectos de los fármacos , Membrana Basal/enzimología , Moléculas de Adhesión Celular/análisis , Células Cultivadas , Colágeno Tipo IV/análisis , Colágeno Tipo VII/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Epidermis/enzimología , Epidermis/efectos de la radiación , Humanos , Masculino , Metaloproteinasa 1 de la Matriz/análisis , Metaloproteinasa 2 de la Matriz/análisis , Metaloproteinasa 3 de la Matriz/análisis , Metaloproteinasa 9 de la Matriz/análisis , Microscopía Electrónica , Modelos Biológicos , Sulfonamidas/farmacología , Inhibidor Tisular de Metaloproteinasa-1/análisis , Inhibidor Tisular de Metaloproteinasa-2/análisis , Kalinina
6.
Plant Cell Rep ; 23(3): 144-7, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15168072

RESUMEN

Plant genomes contain a heavily methylated region in which cytosines are methylated in both the symmetrical and asymmetrical sequences. The physical mapping of such a hypermethylated region is difficult because many restriction enzymes are sensitive to methylated cytosine residues in their recognition sites. The Phi29 DNA polymerase provides an efficient and representative amplification of the genomic DNA that is methylation-free. Using this amplified genomic DNA, we were able to show that a heavily methylated genomic DNA region becomes amenable to physical mapping with any restriction enzymes. This protocol will be especially useful for analysis of the heavily methylated region of plant genomes.


Asunto(s)
Mapeo Cromosómico/métodos , ADN de Plantas/genética , ADN Polimerasa Dirigida por ADN/farmacología , Nicotiana/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Citosina/metabolismo , ADN/genética , ADN/metabolismo , Metilación de ADN , ADN de Plantas/efectos de los fármacos , ADN Polimerasa Dirigida por ADN/metabolismo , Silenciador del Gen , Genoma de Planta , Plantas Modificadas Genéticamente/enzimología , Plantas Modificadas Genéticamente/genética , Nicotiana/enzimología , Transgenes/genética
7.
Osteoarthritis Cartilage ; 10(10): 808-15, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12359167

RESUMEN

OBJECTIVE: To examine the mechanism by which the Arg-->Cys 519 mutation causes the clinical phenotype employing transgenic mice that express the mutated human COL2A1. METHODS: A DNA construct under the control of a COL2A1 specific promoter was prepared from genomic DNA isolated from fibroblasts from the proband with primary generalized osteoarthritis (OA) associated with a mild chondrodysplasia. Transgenic mice were obtained by injection of the constructs into pro-nuclei of fertilized eggs from the FVB/N inbred mouse strain. Transgenic mice harboring two alleles of the mutated human COL2A1 were examined for morphological abnormalities and for alterations of their skeletal development. Ultrastructural examination was performed to identify changes in the organization and density of collagen II fibrils in articular cartilage of the transgenic mice. RESULTS: Transgenic mice harboring two alleles of the mutated human collagen gene were smaller than their normal littermates, had a cleft palate, and disorganized growth plate. Electron microscopy of articular cartilage showed a decreased density of collagen II fibrils and revealed chondrocytes with dilated Golgi cysternae. CONCLUSIONS: Expression of a COL2A1 with an Arg-->Cys 519 substitution in transgenic mice causes retardation of skeletal development and ultrastructural alterations in articular cartilage with a profound reduction of the density of the collagen II fibrils in the tissue. These alterations may be responsible for the phenotype of precocious generalized OA and chondrodysplasia displayed by patients harboring this COL2A1 mutation.


Asunto(s)
Arginina/genética , Huesos/anomalías , Cartílago Articular/patología , Colágeno Tipo II/genética , Cisteína/genética , Esqueleto , Sustitución de Aminoácidos , Animales , Huesos/patología , Condrocitos/patología , Colágeno/genética , Humanos , Ratones , Ratones Transgénicos , Microscopía Electrónica , Mutación Missense , Osteoartritis/genética
8.
Surg Endosc ; 16(9): 1363-4, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12235509

RESUMEN

Hemostasis of a resected stump of liver is extremely difficult in laparoscopic hepatectomy. Although Pringle's maneuver, which is a total clamping of the hepatoduodenal ligament, is a useful technique, it is often difficult in laparoscopic circumstances. Moreover, total inflow occlusion leads to postoperative liver damage. Therefore, the local bleeding method is ideal. The Endoclose, a device for port site closure, is formed from an outer sheath and an inner needle with a notch to load the suture. The Endoclose is loaded with a suture and passed through the liver. The suture is left under the liver, and the device is removed. Next, the suture carrier is passed through the liver at an appropriate distance, and the suture is regrasped by this suture carrier and brought out of the liver. Herein we report a case in which a new bleeding control method using Endoclose was introduced for laparoscopy-assisted hepatectomy.


Asunto(s)
Hepatectomía/instrumentación , Hepatectomía/métodos , Laparoscopía/métodos , Anciano , Hemostasis Endoscópica/instrumentación , Hemostasis Endoscópica/métodos , Humanos , Hígado/irrigación sanguínea , Hígado/diagnóstico por imagen , Hígado/patología , Hígado/cirugía , Neoplasias Hepáticas/irrigación sanguínea , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/cirugía , Masculino , Técnicas de Sutura , Tomografía Computarizada por Rayos X , Ultrasonografía
9.
Cell ; 107(6): 789-800, 2001 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-11747814

RESUMEN

Matrix metalloproteinases (MMPs) are essential for proper extracellular matrix remodeling. We previously found that a membrane-anchored glycoprotein, RECK, negatively regulates MMP-9 and inhibits tumor invasion and metastasis. Here we show that RECK regulates two other MMPs, MMP-2 and MT1-MMP, known to be involved in cancer progression, that mice lacking a functional RECK gene die around E10.5 with defects in collagen fibrils, the basal lamina, and vascular development, and that this phenotype is partially suppressed by MMP-2 null mutation. Also, vascular sprouting is dramatically suppressed in tumors derived from RECK-expressing fibrosarcoma cells grown in nude mice. These results support a role for RECK in the regulation of MMP-2 in vivo and implicate RECK downregulation in tumor angiogenesis.


Asunto(s)
Matriz Extracelular/fisiología , Metaloproteinasas de la Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Neoplasias Experimentales/patología , Neovascularización Patológica , Neovascularización Fisiológica , Animales , Células Cultivadas , Regulación hacia Abajo , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Proteínas Ligadas a GPI , Marcación de Gen , Humanos , Inmunohistoquímica , Metaloproteinasa 14 de la Matriz , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz , Metaloproteinasas de la Matriz/genética , Metaloproteinasas de la Matriz Asociadas a la Membrana , Glicoproteínas de Membrana/genética , Metaloendopeptidasas/antagonistas & inhibidores , Metaloendopeptidasas/genética , Metaloendopeptidasas/metabolismo , Ratones , Ratones Desnudos , Músculo Liso Vascular/metabolismo , Mutación , Trasplante de Neoplasias , Neoplasias Experimentales/metabolismo , Transfección , Células Tumorales Cultivadas
10.
Biochemistry ; 40(48): 14422-8, 2001 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-11724554

RESUMEN

Single amino acid substitutions in collagen II cause heterogeneous cartilage disorders including some chondrodysplasias and certain forms of heritable osteoarthritis. In this study, we examined molecular interactions between normal collagen II and collagen IX, and the effect of a Cys substitution for Arg-alpha1-519 in collagen II on these interactions. Binding assays showed that the association equilibrium constant of collagen IX-collagen II interaction is 15 x 10(6) M(-1). Specificity of the interaction was analyzed by the binding of collagen IX to recombinant collagen II variants lacking fragments of 234 amino acids corresponding to particular D-periods. The results indicated that the C-terminal half of collagen II, which includes the D3 and D4 periods, has a high affinity for collagen IX, and that the nontriple helical telopeptides of collagen II are not essential for the specific binding of collagen IX. Computer analysis of the surface of the mutated collagen II and binding assays showed that a Cys substitution for Arg-alpha1-519 changes electrostatic properties around the mutation site, increases the affinity of mutant collagen II for collagen IX, and possibly alters the specificity of the interaction. Thus, the results indicate that interactions between collagen II and collagen IX are site specific and that single amino acid substitutions in collagen II may change the molecular interactions with collagen IX that could destabilize the cartilaginous matrix.


Asunto(s)
Sustitución de Aminoácidos , Arginina/genética , Colágeno Tipo II/química , Colágeno Tipo IX/química , Cisteína/genética , Proteína Morfogenética Ósea 1 , Proteínas Morfogenéticas Óseas/metabolismo , Colágeno Tipo II/genética , Colágeno Tipo IX/genética , Humanos , Cinética , Metaloendopeptidasas/metabolismo , Mutación , Procolágeno/química , Procolágeno N-Endopeptidasa/metabolismo , Unión Proteica , Proteínas Recombinantes , Relación Estructura-Actividad
11.
Exp Cell Res ; 271(2): 249-62, 2001 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-11716537

RESUMEN

The epidermal basement membrane (BM) plays important roles in adhesion between epidermis and dermis and in controlling epidermal differentiation. In a skin-equivalent (SE), components of the epidermal BM such as laminin 5 and type IV and VII collagens were detected in conditioned media and in basal keratinocytes. Despite production of these BM components, however, BM was rarely observed at the dermal-epidermal junction. One possible explanation for the absence of BM in SEs is that matrix metalloproteinases (MMPs) degrade newly synthesized extracellular matrices. In fact, several MMPs, such as MMPs-1, 2, 3, and 9, were observed to be present in conditioned media and some of them were in active forms. Tissue inhibitor of metalloproteinase (TIMP)-2 was not detected, although TIMP-1 was present. BM degradation activity presumably exceeds BM formation activity in the SE, resulting in the absence of lamina densa at the dermal-epidermal junction. Synthetic MMP inhibitors CGS27023A and MMP inhibitor I, which inhibit MMPs 1, 2, 3, and 9, markedly augmented deposition of laminin 5 and type IV and VII collagens at the dermal-epidermal junction, resulting in formation of continuous epidermal BM. These results suggest that the balance between synthesis and degradation of BM components is important for BM formation.


Asunto(s)
Membrana Basal/metabolismo , Colágeno/metabolismo , Dermis/metabolismo , Epidermis/metabolismo , Matriz Extracelular/metabolismo , Laminina/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Animales , Membrana Basal/efectos de los fármacos , Membrana Basal/ultraestructura , Colágeno/efectos de los fármacos , Colágeno Tipo IV/efectos de los fármacos , Colágeno Tipo IV/metabolismo , Colágeno Tipo VII/efectos de los fármacos , Colágeno Tipo VII/metabolismo , Dermis/efectos de los fármacos , Dermis/ultraestructura , Inhibidores Enzimáticos/farmacología , Epidermis/efectos de los fármacos , Epidermis/ultraestructura , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/ultraestructura , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Queratinocitos/ultraestructura , Laminina/efectos de los fármacos , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz , Ratones , Microscopía Electrónica , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/metabolismo
12.
Surg Endosc ; 15(6): 541-4, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11591936

RESUMEN

BACKGROUND: No reports exist on the role of laparoscopic hepatectomy in the short- and long-term outcomes of patients with hepatocellular carcinoma (HCC). We present our results from using laparoscopic hepatectomy for HCC and discuss the importance of this procedure. METHODS: To investigate the role of laparoscopic hepatectomy in the short- and long-term outcomes, 17 patients with HCC who underwent laparoscopic hepatectomy (laparoscopic hepatectomy group) were compared with 38 patients who underwent conventional open hepatectomy (open hepatectomy group) during the same period. RESULTS: No differences in operation time, blood loss, rate of blood transfusion, or incidence of postoperative complications were found between the two groups. The postoperative hospital stay for the laparoscopic hepatectomy group was significantly shorter than for the open hepatectomy group. With long-term prognosis, no difference was found in survival rate and disease-free survival rate between the two groups. No recurrence was found in the stump of the remaining liver after laparoscopic hepatectomy. CONCLUSIONS: Laparoscopic hepatectomy has resulted in a better short-term outcome after surgery than conventional open hepatectomy. The long-term prognosis in the laparoscopic hepatectomy group was similar to that in the open hepatectomy group. Therefore, laparoscopic hepatectomy can be a new alternative for treatment of cirrhotic patients with HCC when patients are strictly selected.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía , Neoplasias Hepáticas/cirugía , Carcinoma Hepatocelular/sangre , Supervivencia sin Enfermedad , Várices Esofágicas y Gástricas/epidemiología , Humanos , Incidencia , Tiempo de Internación , Neoplasias Hepáticas/sangre , Recuento de Plaquetas , Pronóstico
13.
Nippon Ganka Gakkai Zasshi ; 105(8): 535-8, 2001 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-11558164

RESUMEN

BACKGROUND: We report a 38-year-old female suffering from bilateral optic neuritis with lymphocytic adenohypophysitis. CASE: The initial symptom of the 38-year-old-female was diabetes insipidus. Magnetic resonance imaging showed swollen pituitary stalk and disappearance of the T1 shortening of the neurohypophysis. Immunological tests showed that the serum anterior pituitary antibody was positive. These findings suggested lymphocystic adenohypophysitis. Bilateral optic neuritis also occurred and the pattern visual evoked cortical potential (VECP) demonstrated increased P100 peak latency and reduction of amplitude. After steroid pulse therapy, the visual acuity and field improved and the pattern VECP became normal. Temporal hemianopia was not noted. CONCLUSION: A direct infiltration of the inflammatory change in the pituitary gland or some autoimmune problem was considered as a cause of the optic neuritis. In contrast to the VECPs of multiple sclerosis patients, the prolonged peak latency of pattern VECPs of this case were shortened in accordance with the recovery of visual acuity.


Asunto(s)
Potenciales Evocados Visuales , Linfocitos/patología , Neuritis Óptica/etiología , Neuritis Óptica/fisiopatología , Enfermedades de la Hipófisis/complicaciones , Enfermedades de la Hipófisis/patología , Adenohipófisis/patología , Adulto , Femenino , Estudios de Seguimiento , Humanos , Inflamación
14.
Transplantation ; 71(12): 1757-65, 2001 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-11455255

RESUMEN

BACKGROUND: The changes in the basement membrane occurring in acutely deteriorated renal allografts (ADR) have not been extensively investigated. Our purpose is to elucidate the alteration of collagen IV, a main constituent of the basement membrane in ADR. METHODS: Fifty biopsy specimens of ADR and 10 of chronic transplant nephropathy (CTN) were examined with two monoclonal antibodies specific for collagen IV. JK199 and JK132 are monoclonal antibodies that recognize triple helical collagen IV containing the alpha1 chain. JK199 recognizes all the basement membrane containing [alpha1 (IV)]2alpha2(IV), although JK132 reacts only with a limited portion of it. In the normal kidney, JK199 reacts with the mesangial matrix, the basement membrane of Bowman's capsule (BBM), and the tubular basement membrane, as well as with the glomelular basement membrane (GBM). JK132 reacts with the mesangial matrix, BBM, and the tubular basement membrane. RESULTS: In ADR, increased intensity of JK199 was observed in GBM, the mesangial matrix, BBM, the tubular basement membrane, and the interstitium. Increased intensity of JK132 was observed in the mesangial matrix, BBM, and the tubular basement membrane, but was not remarkable in GBM or the interstitium. In contrast, biopsy specimens of CTN showed increased intensity of JK132 in GBM, the mesangial matrix, BBM, the tubular basement membrane and the interstitium. CONCLUSION: These results suggest that collagen IV is up-regulated in ADR. Differential staining of collagen IV with JK199 and JK132 in GBM and the interstitium may contribute to diagnose CTN.


Asunto(s)
Colágeno/metabolismo , Trasplante de Riñón , Riñón/metabolismo , Riñón/patología , Adulto , Femenino , Humanos , Inmunohistoquímica , Enfermedades Renales/etiología , Enfermedades Renales/patología , Trasplante de Riñón/efectos adversos , Masculino , Persona de Mediana Edad , Trasplante Homólogo
16.
Cytokine ; 13(3): 188-91, 2001 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-11161464

RESUMEN

OBJECTIVE: The aim of this study is to clarify the perioperative cytokine changes and their mechanism in jaundiced liver. MATERIALS AND METHODS: Obstructive jaundice was induced using a common bile duct ligation (CBDL) and a two-thirds hepatectomy (HEP) was performed in six- to seven-week-old male C3H/HeN mice. When hepatectomy was added to CBDL, it was carried out 2 to 5 days after CBDL. The serum interleukin 6 (IL-6) levels and heat shock protein (HSP)-70 expression were evaluated. One mg per mouse of methylprednisolone (MPL) was intraperitonealy administered in some mice of CBDL+HEP group. RESULTS: The post-hepatectomy IL-6 values at 2 and 3 days after CBDL were significantly lower than those in the HEP group, while those at 5 days after CBDL were significantly higher than those in HEP group. The serum IL-6 value of the steroid group was significantly lower than that of non-steroid group in HEP group. However, no steroid effects were recognized on post-hepatectomy IL-6 values at 3 days after CBDL, steroid inhibited post-hepatectomy IL-6 production at 5 days after CBDL. No expression of HSP70 protein was observed in the control group, but HSP70 protein was expressed in both the hepatocytes and Kupffer cells 3 days after CBDL, then at 5 days after CBDL, no HSP70 protein was expressed in the Kupffer cells. CONCLUSIONS: In the early period of obstructive jaundice, the IL-6 level after hepatectomy did not increase in comparison to HEP group, and steroid had no effect on IL-6 level. According to the progression of obstructive jaundice, the IL-6 level after hepatectomy increased to a higher level than before, and the effect of MPL was restored. HSP70 is thus suggested to have an important role in cytokine production.


Asunto(s)
Colestasis Extrahepática/inmunología , Interleucina-6/sangre , Hígado/inmunología , Hígado/metabolismo , Animales , Colestasis Extrahepática/etiología , Colestasis Extrahepática/metabolismo , Proteínas HSP70 de Choque Térmico/biosíntesis , Hepatectomía , Interleucina-6/biosíntesis , Ligadura , Masculino , Ratones , Ratones Endogámicos C3H , Complicaciones Posoperatorias/inmunología , Complicaciones Posoperatorias/metabolismo
17.
Micron ; 32(3): 317-23, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11006511

RESUMEN

Although the triple-helical structure of fibrillar collagen is regarded in general as being quite similar, each type of collagen molecule has inherent characteristics in the triple-helical domain. Few studies have ever been performed in terms of the aggregate structure of the triple-helical domain of fibrillar collagen. Reconstituted aggregates from the purified triple-helical domain of each type of fibrillar collagen might amplify the subtle differences in the structural characteristics of each type of collagen molecule. In this study, the reconstituted aggregate structure of pepsin-treated type V collagen (type Vp collagen), that is, virtually its triple-helical domain was characterized by transmission electron microscopy. Pepsin-treated type I (type Ip) and type II (type IIp) collagen were compared with type Vp collagen. Unique features of the aggregate structure of the triple-helical domain of the type V collagen can be summarized as follows:These results suggested that the lateral packing of the triple-helical domain of type V collagen is determined by its molecular structure. The characteristics of type Vp collagen fibrils might be explained by their characteristic amino acid composition. A significant feature of the triple-helical domain of type V collagen is the high content of glycosylated hydroxylysine residues. Molecular model building of the collagenous structure suggests that a change in surface roughness is conspicuous by incorporating the glycosylated hydroxylysine residues. More than a ten-fold content of bulky glycosylated hydroxylysine residues in type V collagen compared to that of type I might have a significant influence on both the intermolecular and interfibrillar interactions of the triple-helical domain of type V collagen molecule.


Asunto(s)
Colágeno/química , Colágeno/ultraestructura , Secuencia de Aminoácidos , Animales , Glicosilación , Humanos , Hidroxilisina , Microscopía Electrónica , Modelos Moleculares , Datos de Secuencia Molecular , Pepsina A/metabolismo , Placenta/química , Conformación Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Ratas
18.
J Electron Microsc (Tokyo) ; 49(2): 371-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11108060

RESUMEN

Structures of biological surfaces pressed on to a pure liquid gallium surface were successfully traced on to the gallium surface by quick-freezing below the melting point (28.78 degrees C) in air or water for replication in scanning electron microscopy. Gallium's high surface tension (approximately 700 mN m(-1) at 30 degrees C) deteriorates the spatial resolution of replicas and destroys some types of specimens. Five different biological surfaces were replicated on to gallium surfaces to evaluate spatial resolution and specimen resistance, i.e. reproducibility and applicability. Gallium replication of jewel beetle wing and human hair demonstrated submicron spatial resolution in the horizontal direction at least. Trials of protozoa, bacteria, and culture cell replication showed that protozoa are suited to replication because the cell membrane has characteristic structures with sufficient resistance to the gallium surface.


Asunto(s)
Galio , Microscopía Electrónica de Rastreo/métodos , Técnicas de Réplica , Animales , Células CHO , Escarabajos/ultraestructura , Cricetinae , Eucariontes/ultraestructura , Cabello/ultraestructura , Humanos , Alas de Animales/ultraestructura
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