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1.
Phys Rev Lett ; 118(5): 052701, 2017 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-28211732

RESUMEN

The cross sections of the ^{7}Be(n,α)^{4}He reaction for p-wave neutrons were experimentally determined at E_{c.m.}=0.20-0.81 MeV slightly above the big bang nucleosynthesis (BBN) energy window for the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the ^{7}Be(n,α)^{4}He reaction rate is not large enough to solve the cosmological lithium problem, and this conclusion agrees with the recent result from the direct measurement of the s-wave cross sections using a low-energy neutron beam and the evaluated nuclear data library ENDF/B-VII.1.

2.
Biochim Biophys Acta ; 1163(3): 243-9, 1993 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-8507662

RESUMEN

The amino-acid sequence of purified recombinant pro-major basic protein from Chinese hamster kidney cells was determined to verify the primary structure and glycosylation sites. Reduced and S-carboxamidemethylated protein was first digested with Achromobacter proteinase I. Each peptide was characterized by amino-acid analysis and amino-acid sequence analysis. We could identify all the peptides which were expected from the pro-major basic protein cDNA sequence. Sequence analysis and deglycosylation study revealed that Ser-8, Thr-9, Ser-46 and Asn-70 were glycosylated. The results indicated that proMBP has three types of sugar chains, O-glycoside, N-glycoside and glycosaminoglycan, in the pro-portion.


Asunto(s)
Proteínas Sanguíneas/química , Glicoproteínas/química , Monosacáridos/análisis , Precursores de Proteínas/química , Ribonucleasas , Secuencia de Aminoácidos , Animales , Asparagina/química , Proteínas Sanguíneas/metabolismo , Cricetinae , Proteínas en los Gránulos del Eosinófilo , Glicopéptidos/química , Glicoproteínas/metabolismo , Glicosilación , Datos de Secuencia Molecular , Mapeo Peptídico , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Señales de Clasificación de Proteína/química , Señales de Clasificación de Proteína/metabolismo , Análisis de Secuencia , Serina/química , Serina Endopeptidasas/metabolismo , Treonina/química
3.
Diabetes ; 46(12): 2075-81, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9392499

RESUMEN

Mononuclear cells, including monocytes/macrophages and T-cells, are considered to be involved in the progression of diabetic nephropathy, although the mechanism of their recruitment into diabetic glomeruli is unclear. The intercellular adhesion molecule-1 (ICAM-1) promotes the infiltration of leukocytes into atherosclerotic lesions as well as inflammatory tissues. In the present study, we investigated the expression of ICAM-1 in the glomeruli of streptozotocin-induced diabetic rats. The expression of ICAM-1 was increased significantly during the early stage of diabetes. The number of mononuclear cells, primarily monocytes/macrophages and lymphocytes, was significantly increased in diabetic glomeruli. Mononuclear cell infiltration into diabetic glomeruli was prevented by anti-ICAM-1 monoclonal antibody. Insulin treatment decreased ICAM-1 expression and mononuclear cell infiltration. The ICAM-1 expression on cultured human umbilical vein endothelial cells was not induced under high glucose culture conditions. Glomerular hyperfiltration is a characteristic change in the early stage of diabetic nephropathy. Treatment with aldose reductase inhibitor, which prevented glomerular hyperfiltration without changes in blood glucose levels, decreased ICAM-1 expression and mononuclear cell infiltration. Moreover, we examined the ICAM-1 expression in the glomeruli of the 5/6 nephrectomized rat, which is a model for glomerular hyperfiltration without hyperglycemia. The ICAM-1 expression and infiltration of mononuclear cells was significantly increased in the glomeruli of 5/6 nephrectomized rats. We conclude that ICAM-1 is upregulated and promotes the recruitment of mononuclear cells in diabetic glomeruli. Moreover, glomerular hyperfiltration that occurs in the early stage of diabetic glomeruli may be one of the potential mechanisms of ICAM-1 upregulation in diabetic nephropathy.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Glomérulos Renales/metabolismo , Aldehído Reductasa/antagonistas & inhibidores , Animales , Anticuerpos Monoclonales/farmacología , Células Cultivadas , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Endotelio Vascular/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Inmunohistoquímica , Insulina/uso terapéutico , Molécula 1 de Adhesión Intercelular/inmunología , Glomérulos Renales/patología , Linfocitos/patología , Macrófagos/patología , Masculino , Monocitos/patología , Nefrectomía , Ratas , Ratas Sprague-Dawley , Venas Umbilicales
4.
Mol Immunol ; 29(4): 537-46, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1565101

RESUMEN

We have purified a novel immunoregulatory factor (BMPG: bone-marrow proteoglycan) produced by a T-cell hybridoma, with a monoclonal antibody column. Using an oligonucleotide probe corresponding to the partial amino acid sequence of BMPG, we cloned, sequenced, and expressed a cDNA for BMPG. BMPG has 222 amino acid residues with a 16 N-terminal signal sequence, so the mature form has 206 amino acid residues. BMPG was found to have unique characteristics: it has three types of sugar chains and it shows a marked homology with animal lectins including the human asialoglycoprotein receptor, chicken hepatic lectin and the homing receptor of lymphocytes.


Asunto(s)
Proteínas Sanguíneas , ADN/análisis , Lectinas/genética , Proteoglicanos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cromatografía de Afinidad , Clonación Molecular , ADN/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Proteína Mayor Básica del Eosinófilo , Humanos , Hibridomas , Células Asesinas Naturales/inmunología , Datos de Secuencia Molecular , Mapeo Nucleótido , Proteoglicanos/inmunología , Proteoglicanos/aislamiento & purificación , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Linfocitos T/metabolismo
5.
J Biochem ; 85(3): 699-704, 1979 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-429260

RESUMEN

The rates of synthesis and degradation of arginosuccinate synthetase in rat liver under various dietary conditions were determined. The relative rate of the enzyme synthesis in the livers of rats fed on 70% casein diet was 4.0 times greater than that for rats fed on 5% casein diet. The rate constants of degradation (Kd of argininosuccinate synthetase were estimated to be 0.15 and 0.16 day-1 under 70% and 5% casein feeding, respectively. When the dietary conditions were changed acutely from 70% to 5% casein diet or vice versa, the rates of the enzyme synthesis decreased or increased, respectively, and the rates of enzyme degradation were also affected. The change from 5% to 70% casein diet caused a transient decrease in the rate of degradation. After the enzyme activity had achieved a new steady-state level, the enzyme degradation proceeded at the normal steady rate. On the other hand, the change from 70% to 5% casein diet caused a transient increase in the rate of degradation. Thus, the only factor regulating the amount of enzyme in rat liver is the rate of enzyme synthesis under the steady-state conditions. However, the rates of both enzyme synthesis and degradation are involved in the regulation of the amount of enzyme during dietary transition.


Asunto(s)
Argininosuccinato Sintasa/metabolismo , Proteínas en la Dieta/metabolismo , Ligasas/metabolismo , Hígado/enzimología , Animales , Caseínas/metabolismo , Leucina/metabolismo , Masculino , Proteínas/metabolismo , Ratas
6.
Biophys Chem ; 61(2-3): 63-72, 1996 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-8956480

RESUMEN

Using an in vitro motility assay on acto-H-meromyosin, we studied the sliding velocity of an actin filament driven by two kinds of H-meromyosin heads: H-meromyosin head with ATP bound (fast motor) and with GTP bound (slow motor). We found a significant increase in the sliding velocity owing to the coexistence of the fast motor and the slow motor. This phenomenon may give an important suggestion with regard to the integration over multiple interactions of H-meromyosin heads along the actin filament.


Asunto(s)
Actinas/metabolismo , Adenosina Trifosfato/metabolismo , Guanosina Trifosfato/metabolismo , Subfragmentos de Miosina/metabolismo , Animales , Guanosina 5'-O-(3-Tiotrifosfato)/farmacología , Guanosina Difosfato/farmacología , Cinética , Músculo Esquelético/metabolismo , Unión Proteica , Conejos
7.
Diabetes Res Clin Pract ; 53(3): 149-59, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11483230

RESUMEN

Glomerular hyperfiltration plays a pathogenic role in the early stages of diabetic nephropathy. Experimental studies in laboratory animals suggest that nitric oxide (NO) might be involved in the pathogenesis of glomerular hyperfiltration. We performed a cross-sectional study to determine the relationship between diabetic glomerular hyperfiltration and the NO system. Normoalbuminuric (n=41), microalbuminuric (n=25), and macroalbuminuric (n=16) patients with type 2 diabetes were recruited in this study and compared with age-matched 84 non-diabetic control subjects. Creatinine clearance and urinary NO(2)(-)/NO(3)(-) excretion (urinary NOx) were measured, and the expression of endothelial cell nitric oxide synthase (ecNOS) was evaluated in human renal tissues. Glomerular hyperfiltration was present in 19 (37.5%) and nine (36.6%) of normoalbuminuric and microalbuminuric type 2 diabetic patients, respectively. The urinary NOx was significantly higher in normoalbuminuric patients compared with normal subjects. Creatinine clearance correlated significantly with urinary NOx in normoalbuminuric and microalbuminuric patients. Immunohistochemical staining intensities for ecNOS were significantly increased in glomerular endothelial cells of microalbuminuric type 2 diabetic patients as compared with the control subjects. These results suggest that NO may contribute to the pathogenesis of glomerular hyperfiltration in Japanese type 2 diabetic patients.


Asunto(s)
Albuminuria , Diabetes Mellitus Tipo 2/fisiopatología , Tasa de Filtración Glomerular/fisiología , Óxido Nítrico/fisiología , Adulto , Factores de Edad , Anciano , Animales , Glucemia/metabolismo , Presión Sanguínea , Creatinina/sangre , Creatinina/orina , Estudios Transversales , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/orina , Dihidrolipoamida Deshidrogenasa/análisis , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Hemoglobina Glucada/análisis , Humanos , Glomérulos Renales/enzimología , Masculino , Persona de Mediana Edad , Nitratos/orina , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo III , Nitritos/orina , Valores de Referencia
8.
J Chromatogr A ; 930(1-2): 165-9, 2001 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-11681574

RESUMEN

Peak areas, peak heights, and apparent theoretical plate numbers were examined as a function of sample injection times by use of the batch-type CL detection cell. Comparing the experimental data with those obtained by absorption detector, some considerations were carried out about the peak shape. The peak shape in CL detection was influenced by not only concentration distribution of sample in a sample zone but also sample diffusion and CL reaction at the capillary outlet. The sample injection time of ca. 35 s was recommended for the present CE with CL detector. The injection time much influenced peak shape as well as sensitivity in the CL detection cell.


Asunto(s)
Electroforesis Capilar/instrumentación , Mediciones Luminiscentes
9.
Respir Med ; 89(4): 271-8, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7597266

RESUMEN

Clinical and pathological studies on cryptogenic organizing pneumonitis (COP) were performed in 19 cases diagnosed with transbronchial lung biopsy (TBLB). All patients suffered from fever and several respiratory symptoms. Laboratory data showed increases in erythrocyte sedimentation rate, positivity for C-reactive protein, negative tuberculin reactions and increases in complement level. Pathological findings demonstrated that there were two kinds of organizing processes. Fourteen of the 19 cases were treated with prednisolone, and two cases were observed without administration. The remaining three cases could not be followed up after therapy. In 11 of the 16 cases, abnormal shadows in chest X-ray disappeared, but remained present in five cases. As for the relationship between pathological findings and shadows in chest X-ray, Masson bodies without fibrin were observed in the 11 cases which were without shadows on X-ray, but Masson bodies containing or related to fibrin were observed in the five cases in which abnormal shadows remained. These results suggest that there are two types of organizing process in COP. Type I is an unexplained organizing process in which fibrin is not present or involved. It responds well to steroids and the prognosis is favourable. Type II is an organizing process which involves fibrin, and the character of the fibroblast-like cells is very similar to that of myofibroblasts. Type II organizing process responds poorly to steroids. Both processes can be notified relatively easily, even by TBLB tissues.


Asunto(s)
Neumonía/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fibrina , Fibroblastos/patología , Humanos , Masculino , Persona de Mediana Edad , Neumonía/diagnóstico , Neumonía/tratamiento farmacológico , Prednisolona/uso terapéutico , Pronóstico , Alveolos Pulmonares/patología
10.
Diabetologia ; 48(11): 2402-11, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16231067

RESUMEN

AIMS/HYPOTHESIS: Recent studies have shown that the inflammatory process is involved in the pathogenesis of diabetic nephropathy. Fourteen-membered ring macrolides, including erythromycin, have anti-inflammatory, as well as antibacterial effects. The aim of this study was to investigate the renoprotective effects of erythromycin in streptozotocin (STZ)-induced diabetic rats. METHODS: STZ-induced diabetic rats were treated orally with erythromycin (5 mg/kg body weight) or vehicle every day for 8 weeks. To evaluate the effect of erythromycin treatment, we measured urinary albumin excretion, and examined the following in the kidney: histological changes, the expression of intercellular adhesion molecule-1 (ICAM-1), macrophage infiltration, and nuclear factor-kappa B (NF-kappaB) activity. RESULTS: Erythromycin significantly reduced urinary albumin excretion without affecting blood glucose levels and blood pressure. Erythromycin also attenuated glomerular hypertrophy, mesangial expansion, macrophage infiltration and ICAM-1 expression in renal tissues. The expression of the gene encoding TGFB1 (also known as TGF-beta1), type IV collagen protein production and NF-kappaB activity in renal tissues were increased in diabetic rats and reduced by erythromycin treatment. CONCLUSIONS/INTERPRETATION: Erythromycin prevented renal injuries without changes of blood glucose levels and blood pressure in experimental diabetic rats. These results suggest that the renoprotective effects of erythromycin are based on its anti-inflammatory effect via suppression of NF-kappaB activation. Modulation of microinflammation with erythromycin may provide a new approach for diabetic nephropathy.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/prevención & control , Eritromicina/farmacología , Riñón/efectos de los fármacos , Albuminuria/tratamiento farmacológico , Animales , Quimiocina CCL2/efectos de los fármacos , Quimiocina CCL2/genética , Colágeno Tipo IV/efectos de los fármacos , Colágeno Tipo IV/genética , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/patología , Molécula 1 de Adhesión Intercelular/metabolismo , Riñón/patología , Riñón/fisiología , Macrófagos/efectos de los fármacos , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Ratas , Ratas Sprague-Dawley , Estreptozocina/toxicidad , Factor de Transcripción ReIA/efectos de los fármacos , Factor de Transcripción ReIA/metabolismo , Factor de Crecimiento Transformador beta/efectos de los fármacos , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta1
11.
Nihon Kyobu Shikkan Gakkai Zasshi ; 32(6): 550-4, 1994 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-8089942

RESUMEN

Idiopathic organizing pneumonia (OP) was classified pathologically into two types, and the clinical profiles were compared. Cases in which fibrin in Masson bodies, alpha-sm-actin and m-actin antibodies were negative were regarded as type I (14 cases), and those in which they were positive as type II (7 cases). No significant differences in age and sex were observed between the two groups. As to clinical symptoms and laboratory findings, dyspnea and CRP positivity were observed more frequently and inflammatory reactions were stronger, in type II than in type I. The two groups could not be distinguished by chest X-ray findings. With regard to treatments and outcome, chest X-ray shadows disappeared completely after steroid therapy in type I, and no deaths occurred despite recurrence in some cases. In type II, chest X-ray shadows partially remained in all cases even after steroid therapy, recurrence was rare, and death occurred in some cases due to exacerbations of the initial episode. These observations suggest that there are two pathological types of OP and that the differences in clinical symptoms, laboratory findings, treatments, and prognosis between the two types must be taken into consideration in treating OP.


Asunto(s)
Enfermedades Pulmonares Intersticiales/diagnóstico , Actinas/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Autoanticuerpos/análisis , Bronquiolitis Obliterante/diagnóstico , Bronquiolitis Obliterante/inmunología , Femenino , Fibrina/análisis , Humanos , Inmunohistoquímica , Enfermedades Pulmonares Intersticiales/inmunología , Masculino , Persona de Mediana Edad , Pronóstico
12.
J Biol Chem ; 266(32): 21709-17, 1991 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-1939195

RESUMEN

In the adult dog liver cytosol we identified four glutathione S-transferase (GST) subunits, Yd1 (Mr 26,000), Yd2 (Mr 27,000), Yd3 (Mr 28,000), and Ydf (Mr 27,400), and purified GST forms comprising Yd1, Yd2, and Yd3, to apparent homogeneity. Unlike rat transferases the enzyme activity toward 1,2-dichloro-4-nitrobenzene (DCNB) was not retained on the affinity column. Thus the DCNB-active enzyme, GST YdfYdf, from the flow-through fraction of the affinity column was also purified to homogeneity by gel filtration, DE52 chromatography, chromatofocusing, and hydroxylapatite column chromatography. Immunoblot analysis of dog GSTs revealed that the subunits Yd1, Yd2, and Yd3 belong to the pi, alpha, and mu class, respectively. On the contrary, Ydf had no reactivity with antibodies raised against any of the three classes of GST. Each subunit, Yd1, Yd2, Yd3, and Ydf, was distinguishable by its own retention time on reverse-phase high performance liquid chromatography. N-terminal amino acid sequences of the dog GSTS Yd1Yd1 and Yd3Yd3 revealed a high degree of homology to the pi and mu class transferases from rat, human, and mouse, respectively, while the N terminus of Yd2Yd2 is blocked. N-terminal amino acid sequences of GST YdfYdf showed no homology to any of the three classes of GST. The most significant property noted of GST YdfYdf is the high specific activity toward DCNB, exceeding by 1 order of magnitude the corresponding values for the known mu class GSTs. The present results strongly suggest that dog GST YdfYdf is a unique enzyme distinct from the hitherto characterized GST isozymes.


Asunto(s)
Glutatión Transferasa/metabolismo , Isoenzimas/metabolismo , Hígado/enzimología , Nitrobencenos/metabolismo , Secuencia de Aminoácidos , Animales , Western Blotting , Cromatografía de Afinidad , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Citosol/enzimología , Perros , Electroforesis en Gel de Poliacrilamida , Glutatión Transferasa/genética , Glutatión Transferasa/aislamiento & purificación , Humanos , Inmunodifusión , Isoenzimas/genética , Isoenzimas/aislamiento & purificación , Cinética , Sustancias Macromoleculares , Masculino , Datos de Secuencia Molecular , Peso Molecular , Homología de Secuencia de Ácido Nucleico , Especificidad por Sustrato
13.
Biochem J ; 283 ( Pt 1): 307-11, 1992 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-1567376

RESUMEN

The unique glutathione S-transferase (GST) subunit Yx, which is undetectable in normal adult rat liver cytosol, was shown to occur in the liver cytosol of rats with hereditary hyperbilirubinuria (EHB). The Yx subunit is a member of the Alpha-class GST subunits, and is immunologically closely related to the Yc subunit. The Yx subunit has an apparent M(r) of 26,400, different from those of Ya (M(r) 25,800), Yb1 and Yb2 (both M(r) 27,200) and Yc (M(r) 28,400). During postnatal development in livers of EHB rats, the Yx subunit concentration in either sex was highest during the first week post partum and declined rapidly with age. Although the concentration of subunit Yx at 8 weeks of age accounted for about 60% in females and 40% in males of that observed in 1-week-old 'neonatal' male EHB rats, concentrations in females thereafter increased gradually to almost the neonatal level and remained at this high level at least up to 37 weeks of age, whereas the concentration in males did not increase again. Thus the post-pubertal Yx subunit concentration was 2-fold higher in females than in males. In contrast, in normal Sprague-Dawley rat liver, the Yfetus subunit, with the same M(r) as the Yx subunit, had the highest concentration in 10-day-old animals, declined rapidly thereafter, and was not detectable in the post-pubertal period. The Yfetus subunit was also immunoreactive with an antibody against GST YcYc. The analysis of GST subunits by reverse-phase h.p.l.c. revealed that the Yx subunit was eluted at a retention time different from other known subunits, but coincided with that of Yfetus. The N-terminal amino acid sequence of the Yx subunit displayed a high degree of sequence similarity to that of the Yfetus subunit. These data suggest that the Yx subunit in EHB rats may be very similar to, if not identical with, the Yfetus subunit.


Asunto(s)
Feto/enzimología , Glutatión Transferasa/metabolismo , Hiperbilirrubinemia Hereditaria/enzimología , Hígado/enzimología , Secuencia de Aminoácidos , Animales , Western Blotting , Cromatografía Líquida de Alta Presión , Citosol/enzimología , Femenino , Glutatión Transferasa/fisiología , Immunoblotting , Hígado/crecimiento & desarrollo , Sustancias Macromoleculares , Masculino , Datos de Secuencia Molecular , Embarazo , Ratas , Ratas Endogámicas , Ratas Mutantes
14.
Nephron ; 83(2): 160-4, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10516496

RESUMEN

Paraneoplastic nephrotic syndrome is rare, bur occurs mostly in lung cancer. The glomerular lesion usually exhibits membranous nephropathy. Although surgical therapy has been shown to be effective, the treatment of a paraneoplastic nephrotic syndrome has always been a challenge. Currently no standard therapy has been established, if the paraneoplastic nephrotic syndrome is associated with advanced cancer with unresectable lesions. We present 2 cases having paraneoplastic nephrotic syndrome associated with advanced squamous cell carcinoma of the lung. Radiation therapy of the primary tumor effectively caused regression of the paraneoplastic nephrotic syndrome without affecting the renal function. Our results suggest that irradiation can be the first choice in the treatment of nephrotic syndrome, if the primary tumor is unresectable.


Asunto(s)
Neoplasias Pulmonares/complicaciones , Síndrome Nefrótico/etiología , Síndrome Nefrótico/radioterapia , Anciano , Edema/radioterapia , Glomerulonefritis Membranosa/diagnóstico por imagen , Glomerulonefritis Membranosa/etiología , Glomerulonefritis Membranosa/radioterapia , Humanos , Riñón/patología , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Síndrome Nefrótico/diagnóstico por imagen , Síndromes Paraneoplásicos/radioterapia , Proteinuria/etiología , Proteinuria/patología , Proteinuria/radioterapia , Tomografía Computarizada por Rayos X
15.
Nephron ; 80(4): 408-13, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9832639

RESUMEN

Mannan binding protein (MBP) is a C-type lectin and has a high affinity to mannose and N-acetyl glucosamine. It is also known to activate C4 and C2 without C1 component, which is called 'lectin pathway'. We now report the presence of MBP and MBP-mediated complement activation in renal glomeruli of IgA nephropathy patients using an immunohistochemical method. In 7 of 42 cases with IgA nephropathy, MBP was detected in the glomerular mesangial area and colocalized with IgA1. In 19 cases with other types of IC-mediated glomerulonephritis including lupus nephritis and membranous nephropathy or without nephritis, MBP was not detected in the glomerulus. The C2- and/or C4-positive rate was 87.5% in the MBP-positive group and 20% in the MBP-negative group of IgA nephropathy. In addition, MBP-positive cases showed marked mesangial cell proliferation, lower creatinine clearance (53.4 +/- 10.0 vs. 77. 8 +/- 4.7 ml/min) and higher urinary protein excretion (2.5 +/- 0.9 vs. 0.9 +/- 0.2 g/day) compared with MBP-negative cases. These findings suggested that MBP was involved in glomerular complement activation through the lectin pathway and thus induced glomerular injury of IgA nephropathy. Since oligosaccharide chain alterations such as reduced sialic acid and galactose of IgA1 molecule have been reported in IgA nephropathy patients, MBP might bind to the IgA1 molecule via interaction between MBP and sugar chain.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas Portadoras/fisiología , Activación de Complemento/fisiología , Glomerulonefritis por IGA/metabolismo , Glomérulos Renales/metabolismo , Adulto , División Celular/fisiología , Colectinas , Complemento C2/metabolismo , Complemento C2/fisiología , Complemento C4/metabolismo , Complemento C4/fisiología , Glomerulonefritis por IGA/sangre , Glomerulonefritis por IGA/patología , Humanos , Inmunohistoquímica , Glomérulos Renales/patología , Persona de Mediana Edad
16.
Biochem Biophys Res Commun ; 257(1): 234-8, 1999 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-10092539

RESUMEN

Human mesangial cells (HMCs) respond to angiotensin II stimulation, which modulates their physiological activities, i.e., contraction and proliferation. It has been revealed that focal adhesion kinase (FAK) and paxillin participate in the angiotensin II-mediated signaling and cytoskeletal rearrangements at focal adhesion. We investigated the influences of cell adhesion upon angiotensin II effects in HMCs. In adherent cells, both FAK and paxillin were tyrosine phosphorylated by angiotensin II, while the cell detachment completely inhibited the tyrosine phosphorylation of paxillin. Activation of p44/42 mitogen-activated protein (MAP) kinase by angiotensin II was accentuated in suspended cells. Moreover, p190, a member of Rho GTPase activating protein (GAP), and RasGAP were coprecipitated with paxillin in adherent cells and angiotensin II stimulation reduced the formation of paxillin-p190 and paxillin-RasGAP complexes. These results suggest that the formation of focal adhesion complexes accelerated by accumulation of mesangial matrices may inhibit the proliferation of HMCs by modulating MAP kinase activity and be related to mesangial cell depletion.


Asunto(s)
Angiotensina II/farmacología , Adhesión Celular/efectos de los fármacos , Mesangio Glomerular/metabolismo , Factores de Intercambio de Guanina Nucleótido , Proteínas/metabolismo , Transducción de Señal/efectos de los fármacos , Adhesión Celular/fisiología , Moléculas de Adhesión Celular/metabolismo , Células Cultivadas , Proteínas del Citoesqueleto/metabolismo , Activación Enzimática/efectos de los fármacos , Matriz Extracelular/metabolismo , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Proteínas Activadoras de GTPasa , Mesangio Glomerular/citología , Mesangio Glomerular/efectos de los fármacos , Mesangio Glomerular/enzimología , Humanos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Nucleares/metabolismo , Paxillin , Fosfoproteínas/metabolismo , Fosforilación/efectos de los fármacos , Fosfotirosina/metabolismo , Pruebas de Precipitina , Unión Proteica/efectos de los fármacos , Proteínas Tirosina Quinasas/metabolismo , Proteínas Represoras
17.
Biosci Biotechnol Biochem ; 62(6): 1211-5, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9692206

RESUMEN

The structure of the N-linked carbohydrate chains of peptide isomerase from the venom of the funnel web spider (Agelenopsis aperta) has been analyzed. Carbohydrates were released from peptide isomerase by hydrazinolysis and reductively aminated with 2-aminopyridine. The fluorescent derivatives were purified by phenol/chloroform extraction, followed by size-exclusion HPLC. The structure of the purified pyridylamino (PA-) carbohydrate chains were analyzed by a combination of two-dimensional HPLC mapping, sugar composition analysis, sequential exoglycosidase digestions, and mass spectrometry. The peptide isomerase contains six kinds of N-linked carbohydrate chains of truncated high-mannose type, with a fucose alpha 1-6 linked to the reducing N-acetylglucosamine in approximately 80% of them.


Asunto(s)
Isomerasas de Aminoácido/química , Poliaminas/análisis , Venenos de Araña/análisis , Aminopiridinas , Conformación de Carbohidratos , Secuencia de Carbohidratos , Cromatografía Líquida de Alta Presión , Datos de Secuencia Molecular
18.
J Biol Chem ; 265(13): 7604-9, 1990 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-2159004

RESUMEN

Human lymphotoxin (hLT) and its mutant genes have been constructed by in vitro mutagenesis and expressed in Escherichia coli. A deletion of Lys84 to Lys89 in hLT remarkably enhanced both the cytotoxicity against human WiDr cells (colon adenocarcinoma cell line) and the prostaglandin E2-inducing activity toward human synovial cells by approximately 1000- and 50-fold, respectively. The enhanced biological potency coincided with an increase of receptor binding affinity. Circular dichroism studies and the heat and folding stabilities were similar to those of the native form. We propose that the region of Lys84 to Lys89 forms a loop structure at the hLT molecular surface and plays an important role in modulating the receptor binding and biological activities of hLT.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Deleción Cromosómica , Linfotoxina-alfa/genética , Mutación , Receptores de Superficie Celular/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Dicroismo Circular , Clonación Molecular , Escherichia coli/genética , Genes , Vectores Genéticos , Humanos , Cinética , Linfotoxina-alfa/metabolismo , Linfotoxina-alfa/farmacología , Lisina , Ratones , Datos de Secuencia Molecular , Conformación Proteica , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico
19.
J Biol Chem ; 270(28): 16719-23, 1995 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-7622482

RESUMEN

A novel peptide isomerase was purified from the venom of funnel web spider, Agelenopsis aperta. The complete primary structure of the isomerase has been established by sequence analyses of polypeptide chains, assignments of disulfide bridges, carbohydrate analyses, and mass spectrometry of sugar chains. The isomerase was found to be a 29-kDa polypeptide that consists of an 18-residue light chain and a 243-residue heavy chain connected by a single disulfide bridge. The heavy chain contains three intramolecular disulfide bridges and one N-linked oligosaccharide chain with a simple trimannosyl core structure. A sequence homology search showed a significant similarity of the enzyme with serine proteases, particularly around a putative catalytic triad of the isomerase. The isomerase specifically interconverts the configuration of Ser46 of a 48-amino-acid peptide, omega-agatoxin-TK, and the conversion rate from L-Ser to D-Ser was approximately two times faster than the reverse reaction.


Asunto(s)
Isomerasas de Aminoácido/química , Péptidos/metabolismo , Venenos de Araña/análisis , Isomerasas de Aminoácido/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Serina Endopeptidasas/química , Arañas
20.
Biochem Biophys Res Commun ; 261(3): 820-3, 1999 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-10441508

RESUMEN

Previously, we reported that the formation of focal adhesion accelerated by accumulation of extracellular matrices may inhibit the angiotensin II-stimulated proliferation of human mesangial cells (HMCs). The process is regulated by p44/42 MAP kinase activity through the mediation of paxillin and GTPase activating proteins. In this report, we investigated the effect of integrin molecules on the angiotensin II-induced p44/42 MAP kinase activation in non-adherent HMCs. The results demonstrated that incubation of cells with both antibody to integrin beta(1) chain (K20) and GRGDS peptide induced integrin clustering, paxillin aggregation, and marked suppression of angiotensin II-induced p44/42 MAP kinase activation. On the other hand, incubation of cells with K20 alone induced integrin clustering without paxillin aggregation and the suppressive effect on angiotensin II-stimulated p44/42 MAP kinase activity. Our results strongly suggest the pivotal role of integrins in the inhibitory effect of focal adhesion on p44/42 MAP kinase activity, the checking system against angiotensin II-induced MAP kinase overactivation.


Asunto(s)
Angiotensina II/farmacología , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Adhesión Celular/fisiología , Mesangio Glomerular/enzimología , Integrinas/fisiología , Proteínas Quinasas Activadas por Mitógenos , Anticuerpos/farmacología , Antígenos CD/metabolismo , Moléculas de Adhesión Celular/metabolismo , Células Cultivadas , Proteínas del Citoesqueleto/metabolismo , Activación Enzimática/efectos de los fármacos , GTP Fosfohidrolasas/metabolismo , Humanos , Integrina alfa5 , Integrina beta1/inmunología , Integrina beta1/fisiología , Proteína Quinasa 3 Activada por Mitógenos , Paxillin , Fosfoproteínas/metabolismo
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