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1.
Transplant Proc ; 36(8): 2269-73, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15561215

RESUMEN

BACKGROUND: In Japan ABO-incompatible liver transplantation has been done on >100 occasions up to 2003. However, <30% are cases involving adults. The difficultly of ABO-incompatible liver transplantation is associated with the high frequency of humoral rejection and local disseminated intravascular coagulation (DIC), leading to many postoperative complications. We report a successful case of adult ABO-incompatible liver transplantation with the use of an intrahepatic artery infusion. METHODS: A 36-year-old man with Wilson disease, underwent living donor liver transplantation from an ABO-incompatible donor. The immunosuppressive therapy included multiple perioperative plasmaphereses, splenectomy, and treatment with tacrolimus, methylprednisolone, and cyclophosphamide. The dose and blood level of tacrolimus were the same as in ABO-compatible cases. In addition to these therapies, we administered an intrahepatic arterial infusion with prostaglandin (PG) E1 alone. RESULTS: After perioperative plasmapheresis and cyclophosphamide, antidonor blood group antibody titers remained undiluted and without vascular complications throughout the postoperative course, but there was a tendency for bleeding that continued for 10 days after transplantation. On postoperative day 10, a reexploration was performed for intraabdominal bleeding. During another operation on postoperative day 59 a biloma was found and drained. The patient has now survived for 120 days after transplantation with normal liver function. CONCLUSIONS: Beneficial effect of intrahepatic artery infusion with PGE1 seems to be useful in adult ABO-incompatible liver transplantation.


Asunto(s)
Sistema del Grupo Sanguíneo ABO , Degeneración Hepatolenticular/cirugía , Infusiones Intraarteriales , Trasplante de Hígado/métodos , Adulto , Incompatibilidad de Grupos Sanguíneos , Quimioterapia Combinada , Arteria Hepática , Degeneración Hepatolenticular/sangre , Humanos , Inmunosupresores/uso terapéutico , Cuidados Intraoperatorios , Pruebas de Función Hepática , Trasplante de Hígado/inmunología , Donadores Vivos , Masculino , Plasmaféresis , Esplenectomía , Resultado del Tratamiento
4.
Int Immunol ; 13(4): 495-505, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11282989

RESUMEN

In order to understand the specificity of sequences or structures recognized by a recombinase involved in class switch recombination (CSR), we examined the relative CSR efficiency of various switch sequences in artificial CSR constructs that undergo CSR in CH12F3-2 murine B lymphoma line. Since CSR recombination is not specific to switch regions of different isotypes or orientation of S sequences, we examined the efficiency of S sequences of non-mammalian species and artificial sequences which lack several characters of mammal switch sequences: chicken S(mu), Xenopus S(mu), telomere, multiple cloning site (MCS) and unrelated negative control sequence. CSR occurred in chicken S(mu) and MCS with significantly higher efficiency than the negative control. A common character of these two sequences is that they are rich in palindrome and stem-loop structures. However, telomeres, which are G-rich and repetitive but not palindromic, could not serve as switch sequences at all. The AT-rich Xenopus S(mu) sequence was inefficient but capable of CSR. CSR breakpoint distribution suggests that the cleavage may take place preferentially in the proximity of the junctions (neck) between the loop and stem in the secondary structure of the single-stranded S sequence, which can be formed by palindromic sequences. The results suggest that the secondary structure of S-region sequences which is transiently formed during transcription may be necessary for recognition by class switch recombinase.


Asunto(s)
Cambio de Clase de Inmunoglobulina/genética , Región de Cambio de la Inmunoglobulina/genética , Cadenas mu de Inmunoglobulina/genética , Animales , Secuencia de Bases , Línea Celular , Pollos , Cadenas alfa de Inmunoglobulina , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Alineación de Secuencia , Especificidad de la Especie , Xenopus
6.
Ann Clin Biochem ; 38(Pt 2): 124-8, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11269752

RESUMEN

The authors investigated the binding of human plasma 125I-labelled chylomicrons to Chinese hamster ovary (CHO) cells, i.e. native CHO cells are mutant ldl-A7 cells lacking the low-density lipoproteins receptor, in the absence and presence of exogenous bovine milk lipoprotein lipase (LPL) in the culture medium. Only a small amount of binding to either cell was observed in the absence of added LPL. Exogenously added LPL increased the specific binding of chylomicrons to ldl-A7 cells, as well as to native CHO cells. The enhanced binding of chylomicrons to ldl-A7 cells or native CHO cells by LPL was inhibited by heparinase and a monoclonal antibody against LPL (5D2) which recognizes the carboxyl terminal of LPL. However, the enhanced binding was not inhibited by 1 M NaCl, which abolishes the enzymatic activity of LPL in either ldl-A7 cell or native CHO cells. These results suggest that LPL enhances the binding of chylomicrons to heparan sulphate proteoglycans of CHO cells, and that it is the carboxyl terminal of LPL but not the enzymatic activity of LPL that is essential for LPL to mediate the binding of chylomicrons to CHO cells.


Asunto(s)
Quilomicrones/metabolismo , Lipoproteína Lipasa/farmacología , Animales , Células CHO , Quilomicrones/antagonistas & inhibidores , Quilomicrones/sangre , Quilomicrones/aislamiento & purificación , Cricetinae , Cricetulus , Relación Dosis-Respuesta a Droga , Proteoglicanos de Heparán Sulfato/metabolismo , Liasa de Heparina/farmacología , Humanos , Mutación , Ensayo de Unión Radioligante/métodos , Receptores de LDL/deficiencia , Receptores de LDL/genética , Factores de Tiempo
7.
Rinsho Shinkeigaku ; 41(8): 491-7, 2001 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-11889833

RESUMEN

We reported a 60-year-old man with granulomatous angiitis of the central nervous system (GACNS) manifesting as subacute mental deterioration. His first symptoms were nausea and vomiting which brought him to a hospital, where no abnormality was found except for gastritis. One month later, he began to feel dizziness and brain tumor was suspected by a neurosurgeon with the MRI findings such as abnormal T2 signal and swelling in his brainstem. While he was followed up, he gradually presented mental change, disorientation and dysmnesia with the abnormal T2 signal spreading over the cerebral white matter bilaterally. Corticosteroid therapy was started based on the suspicion of a lymphoproliferative disease, and his symptoms and the abnormal MRI findings improved. Then he was referred to our department for further evaluation. Because we could not find any evidence of systemic diseases and he had been almost fully recovered, we discontinued the therapy. Soon after that, his mental deterioration as well as the abnormal T2 signal lesions on MRI relapsed. By open brain biopsy, the diagnosis of GACNS was established, and steroid pulse therapy was started. His symptoms and the abnormal T2 signal lesions improved gradually and the steroid was tapered to the maintenance dose without remission. Since the laboratory and imaging findings are not specific for the diagnosis of the angiitis confined to the central nervous system, brain biopsy is recommended for these disorders.


Asunto(s)
Trastornos Mentales/etiología , Vasculitis del Sistema Nervioso Central/diagnóstico , Vasculitis del Sistema Nervioso Central/patología , Enfermedad Aguda , Encéfalo/patología , Diagnóstico Diferencial , Progresión de la Enfermedad , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos Mentales/tratamiento farmacológico , Metilprednisolona/administración & dosificación , Persona de Mediana Edad , Quimioterapia por Pulso , Resultado del Tratamiento , Vasculitis del Sistema Nervioso Central/complicaciones
8.
J Atheroscler Thromb ; 8(3): 95-100, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11866037

RESUMEN

High density lipoprotein-cholesterol (HDL-C) levels are inversely related to the incidence of coronary artery disease. We studied the influence of a G(-75)-->A transition in the promoter of the apolipoprotein (apo) A-I gene, a major protein component of HDL, on serum HDL-C levels in hyperlipidemic subjects. Seventy three hyperlipidemic subjects with serum levels of high HDL-C (HDL-C > or = 70 mg/dl, Group H) were compared with hyperlipidemic subjects with levels of HDL-C between 40 and 70 mg/dl (Group N) and those with HDL-C < 40 mg/dl (Group L). Group H showed a higher incidence (45.2%) of low plasma cholesteryl ester transfer protein (CETP) activity than Groups N (9.1%) and L (5.3%) (p < 0.001). Group H had a higher incidence of the G(-75)-->A transition (0.275) than Groups N (0.117, p < 0.05) and L (0.056, p < 0.01), among subjects with normal CETP activities. The HDL-C levels in subjects with the transition (84 +/- 16 mg/dl) were higher than those in subjects without the transition (56 +/- 12 mg/dl) (p < 0.05). These data suggest that a G(-75)-->A transition of the apo A-I gene promoter, in addition to the common mutation of CETP gene, contributes to high HDL-C levels among hyperlipidemic patients in Japan.


Asunto(s)
Adenina/química , Apolipoproteína A-I/genética , HDL-Colesterol/sangre , Glicoproteínas , Guanina/química , Hiperlipidemias/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Proteínas Portadoras/sangre , Proteínas de Transferencia de Ésteres de Colesterol , Humanos , Hiperlipidemias/sangre
9.
Intern Med ; 39(10): 804-9, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11030204

RESUMEN

A 61-year-old Japanese woman with heterozygous familial hypercholesterolemia (FH), type 2 diabetes mellitus and coronary artery disease underwent coronary artery bypass grafting (CABG) utilizing a saphenous vein graft at the age of 46, in June 1984, 6 months before low density lipoprotein (LDL) apheresis was started. She had received LDL apheresis every two weeks, along with combined drug treatment since the age of 47 (December 1984). She had bilateral xanthelasma and Achilles tendon xanthomas. Her fasting baseline serum total cholesterol and triglyceride level were 464 mg/dl and 57 mg/dl, respectively at the age of 47 when she visited our hospital for the first time. Analysis of the genomic DNA from the patient revealed heterozygous amino acid substitution of Leu for Pro664 in the LDL receptor gene. She was diagnosed as type 2 diabetes mellitus at the age of 53. Combined treatment in the steady state yielded a pretreatment LDL cholesterol level of 230+/-14 mg/dl and a posttreatment level of 57+/-7.6. All grafts were widely patent after as long as 14 years since CABG, suggesting that LDL apheresis combined with drug therapy is highly effective in preventing the occlusion of bypass grafts in a patient with heterozygous FH and type 2 diabetes mellitus.


Asunto(s)
Eliminación de Componentes Sanguíneos , Puente de Arteria Coronaria , Oclusión de Injerto Vascular/prevención & control , Hiperlipoproteinemia Tipo II/terapia , Lipoproteínas LDL/sangre , Mutación Puntual , Receptores de LDL/genética , Vena Safena/trasplante , Aorta/cirugía , Angiografía Coronaria , Enfermedad Coronaria/sangre , Enfermedad Coronaria/cirugía , Vasos Coronarios/cirugía , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Estudios de Seguimiento , Oclusión de Injerto Vascular/sangre , Humanos , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/genética , Persona de Mediana Edad , Resultado del Tratamiento
10.
Circulation ; 101(17): 2022-5, 2000 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-10790340

RESUMEN

BACKGROUND: The cyclin-dependent kinase inhibitors (CKIs) have different patterns of expression in vascular diseases. The Kip/Cip CKIs, p27(Kip1) and p21(Cip1), are upregulated during arterial repair and negatively regulate the growth of vascular smooth muscle cells (VSMCs). In contrast, the Ink CKI, p16(Ink4), is not expressed in vascular lesions. We hypothesized that a variation in the inactivation of cdk2 and cdk4 during the G(1) phase of the cell cycle by p27(Kip1), p21(Cip1), and p16(Ink4) leads to different effects on VSMC growth in vitro and in vivo. METHODS AND RESULTS: The expression of p27(Kip1) and p21(Cip1) in serum-stimulated VSMCs inactivated cdk2 and cdk4, leading to G(1) growth arrest. p16(Ink4) inhibited cdk4, but not cdk2, kinase activity, producing partial inhibition of VSMC growth in vitro. In an in vivo model of vascular injury, overexpression of p27(Kip1) reduced intimal VSMC proliferation by 52% (P<0.01) and the intima/media area ratio by 51% (P<0.005) after vascular injury and gene transfer to pig arteries, when compared with control arteries. p16(Ink4) was a weak inhibitor of intimal VSMC proliferation in injured arteries (P=NS), and it did not significantly reduce intima/media area ratios (P=NS), which is consistent with its minor effects on VSMC growth in vitro. CONCLUSIONS: p27(Kip1) and p21(Cip1) are potent inhibitors of VSMC growth compared with p16(Ink4) because of their different molecular mechanisms of cyclin-dependent kinase inhibition in the G(1) phase of the cell cycle. These findings have important implications for our understanding of the pathophysiology of vascular proliferative diseases and for the development of molecular therapies.


Asunto(s)
Quinasas CDC2-CDC28 , Proteínas Portadoras/farmacología , Proteínas de Ciclo Celular , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Ciclinas/farmacología , Proteínas Asociadas a Microtúbulos/farmacología , Músculo Liso Vascular/citología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas , Proteínas Supresoras de Tumor , Animales , Proteínas Portadoras/metabolismo , División Celular/efectos de los fármacos , Células Cultivadas , Quinasa 2 Dependiente de la Ciclina , Quinasa 4 Dependiente de la Ciclina , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Ciclinas/metabolismo , Expresión Génica , Proteínas Asociadas a Microtúbulos/metabolismo , Porcinos
11.
Eur J Biochem ; 267(11): 3189-97, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10824103

RESUMEN

A novel trypsin-type serine proteinase, which processes the precursors of the envelope fusion glycoproteins of pneumotropic Sendai and human influenza A viruses, was purified to homogeneity from pig lungs. On SDS/PAGE, the purified enzyme gave a protein band corresponding to about 32 kDa, and has an apparent molecular mass of 120 kDa, as determined by gel permeation chromatography. Immunohistochemical staining with antibodies against this enzyme revealed that the enzyme is located in pig lung mast cells. The N-terminal 44-amino-acid sequence of the enzyme exhibits about 80% identity with those of mast cell tryptases from other species. Of the inhibitors tested, di-isopropyl fluorophosphate, antipain, leupeptin, benzamidine and a few proteinaceous inhibitors, such as mucus protease inhibitor and aprotinin, inhibited this enzyme activity. Heparin stabilized the enzyme, but high-ionic-strength conditions did not, unlike for human mast cell tryptase. The purified enzyme efficiently processed the fusion glycoprotein precursor of Sendai virus and slowly processed hemagglutinin of human influenza A virus, and triggered the infectivity of Sendai virus in a dose-dependent manner, although human mast cell tryptase beta and rat mast cell tryptase (rat MCP-7) from lungs did not process these fusion glycoproteins at all. These results suggest that mast cell tryptase in pig lungs is the possible trigger of the pneumotropic virus infections.


Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Virus de la Influenza A/fisiología , Pulmón/citología , Mastocitos/enzimología , Precursores de Proteínas/metabolismo , Respirovirus/fisiología , Serina Endopeptidasas/fisiología , Proteínas del Envoltorio Viral/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Cromatografía en Gel , Quimasas , Activación Enzimática/efectos de los fármacos , Heparina/farmacología , Humanos , Concentración de Iones de Hidrógeno , Mamíferos/metabolismo , Datos de Secuencia Molecular , Peso Molecular , Ratas , Alineación de Secuencia , Homología de Secuencia , Serina Endopeptidasas/aislamiento & purificación , Inhibidores de Serina Proteinasa/farmacología , Especificidad de la Especie , Especificidad por Sustrato , Porcinos , Triptasas , Virulencia , Cultivo de Virus
12.
Atherosclerosis ; 149(2): 351-8, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10729385

RESUMEN

The mechanism of diabetic macroangiopathy was studied from the view point of phenotypic change of arterial smooth muscle cells (SMC). Otsuka Long-Evans Tokushima fatty (OLETF) rat, an animal model of non-insulin dependent diabetes mellitus (NIDDM), develops spontaneous persistent hyperglycemia after the age of 18 weeks. Medial SMC in OLETF rats expressed more platelet-derived growth factor (PDGF) beta-receptor and fibronectin at the protein level than those from control, Long-Evans Tokushima Otsuka (LETO) rats, not only after but also before the onset of diabetes mellitus. Cultured SMC from OLETF rats more strongly responded specifically to the mitogenic stimuli of PDGF-AB and PDGF-BB and also expressed PDGF beta-receptor more intensely compared with those from LETO rats. PDGF is known to be the main contributor to the intimal thickening induced by balloon catheter injury, which is one of several forms of arterial injuries. Intimal thickening of carotid arteries in OLETF rats after balloon catheter injury increased compared with that in LETO rats before the onset of diabetes mellitus. In in vitro culture system, fibronectin synthesis was stimulated by transforming growth factor-beta1(TGF-beta1) in SMC from OLETF rats, but not in those from LETO rats, suggesting that SMC from OLETF rats respond to TGF-beta1. These results indicate that overexpression of PDGF beta-receptor and fibronectin in medial SMC plays an important role in the accelerated intimal thickening before the onset of diabetes mellitus in OLETF rats.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Fibronectinas/metabolismo , Músculo Liso Vascular/metabolismo , Factor de Crecimiento Derivado de Plaquetas/análisis , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/análisis , Animales , Aorta Torácica/citología , Aorta Torácica/patología , Becaplermina , División Celular , Células Cultivadas , ADN/análisis , ADN/biosíntesis , Modelos Animales de Enfermedad , Fibronectinas/análisis , Masculino , Músculo Liso Vascular/citología , Músculo Liso Vascular/patología , Factor de Crecimiento Derivado de Plaquetas/farmacología , Proteínas Proto-Oncogénicas c-sis , Ratas , Ratas Endogámicas OLETF , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Valores de Referencia , Sensibilidad y Especificidad , Túnica Íntima/lesiones , Túnica Íntima/patología
13.
Endocr J ; 47(5): 557-62, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11200935

RESUMEN

In this study, we analyzed plasma lipid and lipoprotein levels before and after treatment with 1-desamino-8-D-arginine vasopressin (DDAVP) in subjects with partial and complete central diabetes insipidus (DI) in order to determine how a shortage and supplement of this hormone affect plasma lipid metabolism. The subjects consisted of 6 patients with partial and 6 with complete central DI. After treatment with DDAVP through nasal cavity, plasma total cholesterol (TC) level did not decrease either in complete or partial form. Plasma triglyceride (TG) levels decreased from 306+/-175 mg/dl to 198+/-91 (35% decrease, p=0.027) in complete form, while TG did not change significantly in partial form. A detailed investigation of plasma lipoprotein metabolism during treatment with DDAVP was carried out in 3 of the 6 subjects with complete form of DI. Lipoprotein lipase activity and mass in post-heparin plasma from those three subjects tended to increase after treatment with DDAVP, along with the complete disappearance of an unusual lipoprotein between low density lipoprotein (LDL) and very low density lipoprotein (VLDL) as analyzed by polyacrylamide gel electrophoresis. These results suggest that the DDAVP treatment has a favorable effect on lipid and lipoprotein metabolism, especially triglyceride-rich lipoproteins, either directly or through modifying factors contributing to lipid metabolism.


Asunto(s)
Diabetes Insípida Neurogénica/complicaciones , Hiperlipidemias/complicaciones , Administración Intranasal , Colesterol/sangre , HDL-Colesterol/sangre , Desamino Arginina Vasopresina/administración & dosificación , Desamino Arginina Vasopresina/uso terapéutico , Diabetes Insípida Neurogénica/sangre , Femenino , Humanos , Hiperlipidemias/sangre , Hiperlipidemias/tratamiento farmacológico , Lipasa/sangre , Lipoproteína Lipasa/sangre , Hígado/enzimología , Masculino , Persona de Mediana Edad , Triglicéridos/sangre
14.
Scand J Clin Lab Invest ; 59(3): 159-66, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10400160

RESUMEN

In order to test whether a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor has an anti-atherogenic activity, the effects of carvastatin, a newly developed potent inhibitor, and pravastatin were examined on the intimal thickening of the artery after the endothelial denudation induced by balloon catheter injury. Rabbits were divided into four groups; control, pravastatin-treated (20 mg kg(-1) day(-1)) and two of carvastatin-treated groups (10 or 20 mg kg(-1) day(-1)). Two weeks after balloon catheter injury, the areas of intima and media of the injured carotid arteries were determined, and the ratios of intima to media (I/M) were calculated as an index of intimal thickening. Average I/M ratios of the injured artery were 0.42+/-0.05 for control, 0.49+/-0.07 for pravastatin, 0.19+/-0.03 (10 mg kg(-1) day(-1)) and 0.20+/-0.04 (20 mg kg(-1) day(-1)) for carvastatin-treated rabbits, respectively. Thus, carvastatin reduced I/M ratio of the injured artery to approximately half versus control, but pravastatin failed to suppress the intimal thickening. For in vitro study, vascular smooth muscle cells (SMC) from rabbit aorta were explanted, then cultured, and the effects of carvastatin on SMC migration and SMC proliferation were also examined. Carvastatin inhibited dose-dependently SMC migration and SMC proliferation with IC50 values of 0.5 microM and 1 microM, respectively. These inhibitory effects of carvastatin were cancelled by the coexistence of mevalonate, a metabolite of cholesterol synthesis. Our results suggest that carvastatin may be useful in rabbits as an anti-atherogenic drug by means of the inhibition of SMC migaration or SMC proliferation.


Asunto(s)
Arterias Carótidas/efectos de los fármacos , Cateterismo/efectos adversos , Movimiento Celular/efectos de los fármacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Músculo Liso Vascular/citología , Naftalenos/farmacología , Piranos/farmacología , Animales , Anticoagulantes/farmacología , Arteriosclerosis/tratamiento farmacológico , Arteriosclerosis/patología , Becaplermina , Carcinoma Hepatocelular , Arterias Carótidas/patología , División Celular/efectos de los fármacos , LDL-Colesterol/biosíntesis , Humanos , Masculino , Ácido Mevalónico/farmacología , Músculo Liso Vascular/química , Músculo Liso Vascular/metabolismo , Naftalenos/química , Factor de Crecimiento Derivado de Plaquetas/farmacología , Pravastatina/farmacología , Proteínas Proto-Oncogénicas c-sis , Piranos/química , Conejos , Receptores de LDL/biosíntesis , Células Tumorales Cultivadas , Túnica Íntima/efectos de los fármacos
15.
Scand J Clin Lab Invest ; 59(2): 71-6, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10353318

RESUMEN

The role of sialic acid linked with lipoprotein lipase (LPL) in its catalytic activity was studied. When LPL was treated with sialidase, the molecular weight decreased by 2000. The sialidase-treated LPL showed unchanged hydrolyzing activity for tributyrin, a water-soluble substrate of esterase, compared with the untreated LPL. The sialidase-treated LPL also showed similar hydrolyzing activity for triolein emulsified with Triton X-100, phosphatidylcholine and phosphatidylethanolamine, whereas it showed significantly increased hydrolyzing activity for triolein emulsified with phosphatidylserine and cardiolipin (152% and 183%, compared with untreated LPL, respectively). In addition, the sialidase-treated LPL showed significantly increased hydrolyzing activity against triolein incorporated into very low-density lipoproteins and chylomicrons (151% and 186%, compared with the untreated LPL, respectively). These results suggest that the loss of sialic acids does not modify the function of the catalytic site of LPL, but facilitates the interaction of the enzyme with the interface of the surface of substrate lipoproteins.


Asunto(s)
Lipoproteína Lipasa/química , Ácidos Siálicos/química , Animales , Sitios de Unión , Células CHO , Catálisis , Cricetinae , Esterasas/análisis , Humanos , Cinética , Lipoproteínas/química , Neuraminidasa/química , Octoxinol/farmacología , Fosfolípidos/farmacología , Especificidad por Sustrato , Triglicéridos/química , Trioleína/química
18.
Eur J Clin Invest ; 28(9): 712-9, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9767370

RESUMEN

BACKGROUND: In mutations of the low-density lipoprotein (LDL) receptor gene, the defect of internalization is caused by a mutation in the cytoplasmic domain of the receptor linked with exons 17 and 18, and the O-linked sugar domain linked with exon 15 has been speculated not to affect the function of the receptor. Here, we describe a novel mutation of the O-linked sugar domain of the LDL receptor gene, designated familial hypercholesterolaemia (FH)-Mishima with Japanese pedigree, which resembles but still differs from classical defective internalization cases. METHODS: LDL metabolism was examined in cultured skin fibroblasts from patients. Immunoprecipitation and immunohistochemical techniques were applied for the detection of the receptor protein size and distribution. Screening of the mutant exon(s) of the LDL receptor gene was performed using the polymerase chain reaction-single-strand conformation polymorphism technique (PCR-SSCP), and sequencing of the mutated alleles was carried out using the dideoxy chain termination method. RESULTS: LDL-binding activity at 4 degrees C in skin fibroblasts from patients was similar to normal, but that at 37 degrees C with the ligand decreased time dependently and was lost at 6 h, resulting in the defect of internalization and degradation of LDL. The receptor protein on the cell surface was detected at 4 degrees C by IgG-C7, an anti-LDL receptor antibody, but was not detected after incubation with LDL at 37 degrees C. The size of the receptor was 112 kD as determined by immunoprecipitation analysis. A deletion of two nucleotides in exon 15 was detected in the DNA sequence of the LDL receptor gene. The deletion results in a shift of the reading frame after Thr-713 of the mutant and makes a stop codon at amino acid 759. CONCLUSION: Deletion of the two nucleotides caused novel amino acid sequences after the O-linked sugar domain, which has the ability of sorting on the cell membrane at 4 degrees C, but not at 37 degrees C in vivo, resulting in the complete cessation of activity of the LDL receptor.


Asunto(s)
Hiperlipoproteinemia Tipo II/genética , Receptores de LDL/genética , Eliminación de Secuencia , Secuencia de Aminoácidos , Secuencia de Bases , Membrana Celular/metabolismo , Células Cultivadas , Niño , ADN/genética , Exones , Femenino , Fibroblastos/metabolismo , Humanos , Hiperlipoproteinemia Tipo II/metabolismo , Japón , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/metabolismo , Masculino , Datos de Secuencia Molecular , Peso Molecular , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Receptores de LDL/química , Receptores de LDL/metabolismo , Temperatura
19.
Clin Endocrinol (Oxf) ; 48(4): 515-20, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9640420

RESUMEN

OBJECTIVES: The purpose of this study was to investigate the possibility of impaired lipolysis of triglyceride-rich lipoproteins in patients with abdominal visceral fat accumulation by assessing two major lipolytic enzymes in the plasma, lipoprotein lipase (LPL) and hepatic lipase (HL). DESIGN AND PATIENTS: A total of 31 patients [20 men, 11 women, age 50 +/- 7 years old, body mass index (BMI) 26 +/- 2 kg/m2 (mean +/- sd)] were analyzed. Visceral fat and subcutaneous fat areas were evaluated using a computerized tomographic (CT) method at the level of the umbilicus. Total lipolytic activity in the postheparin plasma (PHP) was measured using Triton X-100-emulsified triolein and LPL activity was calculated as the activity in whole plasma inhibited by the 5D2 monoclonal antibody for LPL. LPL enzyme mass was determined by a sandwich enzyme immunoassay. RESULTS: The visceral fat area was found to be negatively correlated with LPL mass (V vs LPL mass, r = -0.37, P = 0.04) in PHP and had a tendency toward negative correlation with the LPL activity in the PHP (V vs LPL activity, r = -0.29, P = 0.12). Subcutaneous fat area, on the other hand, did not show any correlation with LPL activity (r = 0.13, P = 0.49) or mass (r = 0.22, P = 0.25) in the PHP. The visceral fat area was found to be positively correlated with fasting serum insulin levels (r = 0.67, P < 0.01). Body mass index (BMI) was not correlated with LPL mass or activity in the PHP. Multi-regressional analysis showed that abdominal visceral fat could be correlated with LPL mass in the PHP, independently of fasting serum insulin. The HL activity from PHP of the patients did not show significant correlation with visceral fat area, subcutaneous fat area or body mass index. CONCLUSIONS: Fat distribution affects LPL mass and activity, either directly or via another metabolic abnormality such as insulin resistance, leading to impaired hydrolysis of triglycerides in chylomicrons and very low density lipoproteins (VLDL) in these subjects.


Asunto(s)
Constitución Corporal , Lipoproteína Lipasa/sangre , Obesidad/enzimología , Abdomen , Ayuno , Femenino , Humanos , Insulina/sangre , Lipasa/sangre , Lipólisis , Hígado/enzimología , Masculino , Persona de Mediana Edad , Triglicéridos/metabolismo
20.
Scand J Clin Lab Invest ; 58(2): 149-54, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9587167

RESUMEN

Effects of fatty acids on intimal thickening induced by a balloon catheter injury model were investigated by feeding rabbits a small amount of either lard [L] or fish oil [F]. Serum lipids of these groups were not different from those of basal diet-fed rabbits [controls] after 4 weeks of feeding. Serum saturated fatty acids such as 14:0, 16:0, and 18.0 were significantly greater in the L-fed rabbits compared with controls, but those of the aorta were not significantly different. Fatty acid composition of the F-fed rabbits was only different from that of the controls in that n-3 fatty acids slightly increased. The mean and maximum intimal thickening 2 weeks after ballooning, carried out 2 weeks after feeding, were significantly higher in the carotid arteries of the L-fed rabbits than in the controls. The intimal thickening of the F-fed rabbits did not significantly differ from that of the controls. These results suggest that lard promotes the formation of the smooth muscle cell dominant type of arteriosclerosis without affecting serum lipid levels.


Asunto(s)
Cateterismo , Grasas de la Dieta/administración & dosificación , Lípidos/sangre , Túnica Íntima/patología , Alimentación Animal , Animales , Peso Corporal , Colesterol/sangre , HDL-Colesterol/sangre , Grasas de la Dieta/efectos adversos , Modelos Animales de Enfermedad , Ácidos Grasos/sangre , Aceites de Pescado/administración & dosificación , Masculino , Conejos , Trombosis/sangre , Trombosis/etiología , Trombosis/patología , Triglicéridos/sangre
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