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1.
Fungal Syst Evol ; 4: 21-31, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32467904

RESUMO

Olpidiopsis is a genus of obligate holocarpic endobiotic oomycetes. Most of the species classified in the genus are known only from their morphology and life cycle, and a few have been examined for their ultrastructure or molecular phylogeny. However, the taxonomic placement of all sequenced species is provisional, as no sequence data are available for the type species, O. saprolegniae, to consolidate the taxonomy of species currently placed in the genus. Thus, efforts were undertaken to isolate O. saprolegniae from its type host, Saprolegnia parasitica and to infer its phylogenetic placement based on 18S rDNA sequences. As most species of Olpidiopsis for which sequence data are available are from rhodophyte hosts, we have also isolated the type species of the rhodophyte-parasitic genus Pontisma, P. lagenidioides and obtained partial 18S rDNA sequences. Phylogenetic reconstructions in the current study revealed that O. saprolegniae from Saprolegnia parasitica forms a monophyletic group with a morphologically similar isolate from S. ferax, and a morphologically and phylogenetically more divergent species from S. terrestris. However, they were widely separated from a monophyletic, yet unsupported clade containing P. lagenidioides and red algal parasites previously classified in Olpidiopsis. Consequently, all holocarpic parasites in red algae should be considered to be members of the genus Pontisma as previously suggested by some researchers. In addition, a new species of Olpidiopsis, O. parthenogenetica is introduced to accommodate the pathogen of S. terrestris.

2.
Vox Sang ; 113(3): 290-296, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29280152

RESUMO

BACKGROUND AND OBJECTIVE: The rare Ko phenotype lacks all 36 antigens in the Kell blood system. The molecular basis of the Ko phenotype has been investigated, and more than 40 silent KEL alleles are reported by many investigators. The majority of silent alleles are the KEL*02 background. Here, we report molecular genetic analysis of the KEL gene in Japanese individuals with the Ko phenotype. MATERIALS AND METHODS: The Ko phenotype was screened from Japanese blood donors for several years using monoclonal anti-Ku or anti-K14 by an automated blood grouping system PK7300. Kell-related antigens were typed by standard tube tests. Genomic DNA was extracted from the blood samples, and KEL gene was analysed by polymerase chain reaction (PCR) and Sanger sequencing. RESULTS: We collected 35 Ko blood samples with K-k-, Kp(a-b-), Js(a-b-) and K14-. PCR and sequence analysis revealed that 11 individuals were homozygous for a mutant KEL allele with a c.299G>C (p.Cys100Ser) mutation (rs. 200268316). Three individuals were homozygous for the KEL*02N.24 allele that is c.715G>T (p.Glu239*), and one individual was homozygous for the KEL*02N.40 allele that is c.1474C>T (p.Arg492*). Five individuals were homozygous for novel KEL alleles with single-nucleotide mutations, four individuals had a c.2175delC (p.Pro725 fs*43), and one individual had a c.328delA (p.Arg110 fs*79). The remaining 15 individuals were compound heterozygous, and eight new alleles were identified from them. CONCLUSIONS: We identified three known and ten new silent KEL alleles from Japanese individuals with the Ko phenotype. The KEL allele with the c.299G>C (p.Cys100Ser) mutation was the most frequent.


Assuntos
Alelos , Glicoproteínas de Membrana/genética , Metaloendopeptidases/genética , Fenótipo , Genótipo , Humanos , Japão , Mutação
3.
Lupus ; 23(4): 342-52, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24474704

RESUMO

OBJECTIVE: A glycosylated transmembrane protein, CD147, has been implicated in regulating lymphocyte responsiveness and leukocyte recruitment. As lupus nephritis (LN) often follows a relapsing-remitting disease course, accurate understanding of the disease activity would be extremely helpful in improving prognosis. Unfortunately, neither clinical nor serological data can accurately reflect the histological features of LN. The present study investigated whether CD147 can accurately predict pathological features of LN. METHODS: Plasma and spot urine samples were collected from 64 patients who underwent renal biopsy between 2008 and 2011. Disease activity for LN tissues was evaluated using the biopsy activity index, and compared to levels of biomarkers including CD147. RESULTS: In LN tissues, CD147 induction was striking in injured glomeruli and infiltrating inflammatory cells, but not in damaged tubules representing atrophy. Plasma CD147 levels accurately reflected the histological disease activity. However, prediction using a single molecule would be quite difficult because of the complex pathogenesis of LN. The diagnostic accuracy of multiplex parameters indicated that the combination including plasma CD147 might yield excellent diagnostic abilities for guiding ideal LN therapy. CONCLUSION: Plasma CD147 levels might offer useful insights into disease activity as a crucial biomarker in patients with LN.


Assuntos
Basigina/sangue , Nefrite Lúpica/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Nefrite Lúpica/sangue , Nefrite Lúpica/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
4.
Transfus Apher Sci ; 48(1): 21-34, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22985534

RESUMO

In 2007, the Japanese Red Cross Blood Center performed a large-scale questionnaire study of post-donation adverse reactions. The questionnaire was distributed to 98,389 donors, and the answers were returned by 55,231 (56.1%). In total, 2,877 (5.2%) complained of an adverse reaction. Assuming that there were no adverse reactions for the 46,150 donors who did not reply, the rate of adverse reaction can be speculated to be 2.8%. Our study strongly suggests that blood centers have long underestimated the risks of vaso-vagal reactions. Taking at least 6h of careful rest after donation would be a helpful counter measure.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Inquéritos e Questionários/normas , Síncope Vasovagal/etiologia , Adulto , Humanos , Japão , Masculino , Fatores de Risco
5.
Vox Sang ; 97(3): 240-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19476605

RESUMO

BACKGROUND AND OBJECTIVES: Morbidity and mortality from ABO-incompatible transfusion persist as consequences of human error. Even so, insufficient attention has been given to improving transfusion safety within the hospital. MATERIALS AND METHODS: National surveys of ABO-incompatible blood transfusions were conducted by the Japanese Society of Blood Transfusion, with support from the Ministry of Health, Labor and Welfare. Surveys concluded in 2000 and 2005 analysed ABO-incompatible transfusion data from the previous 5 years (January 1995 to December 1999 and January 2000 to December 2004, respectively). The first survey targeted 777 hospitals and the second, 1355 hospitals. Data were collected through anonymous questionnaires. RESULTS: The first survey achieved a 77.4% response rate (578 of 777 hospitals). The second survey collected data from 251 more hospitals, but with a lower response rate (61.2%, or 829 of 1355 hospitals). The first survey analysed 166 incidents from 578 hospitals, vs. 60 incidents from 829 hospitals in the second survey. The main cause of ABO-incompatible transfusion was identification error between patient and blood product: 55% (91 of 166) in the first survey and 45% (27 of 60) in the second. Patient outcomes included nine preventable deaths from 1995 to 1999, and eight preventable deaths from 2000 to 2004. CONCLUSION: Misidentification at the bedside persists as the main cause of ABO-incompatible transfusion.


Assuntos
Sistema ABO de Grupos Sanguíneos/análise , Incompatibilidade de Grupos Sanguíneos/epidemiologia , Erros Médicos/estatística & dados numéricos , Reação Transfusional , Acreditação , Bancos de Sangue/organização & administração , Bancos de Sangue/normas , Bancos de Sangue/estatística & dados numéricos , Incompatibilidade de Grupos Sanguíneos/etiologia , Tipagem e Reações Cruzadas Sanguíneas , Transfusão de Sangue/estatística & dados numéricos , Emergências , Inquéritos Epidemiológicos , Número de Leitos em Hospital , Hospitais/normas , Hospitais/estatística & dados numéricos , Humanos , Japão/epidemiologia , Laboratórios Hospitalares/organização & administração , Laboratórios Hospitalares/normas , Laboratórios Hospitalares/estatística & dados numéricos , Erros Médicos/prevenção & controle , Sistemas de Registro de Ordens Médicas , Sistemas de Medicação no Hospital , Sistemas de Identificação de Pacientes
8.
J Pept Res ; 65(5): 485-90, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15853942

RESUMO

In flow cytometry using two detecting methods, we have found that amyloid-beta-protein(1-40) [Abeta(1-40)] has high affinity to IMR-32 neuroblastoma cell membrane when it is aggregated to form beta-sheet conformation, whereas random coil small Abeta-species has low affinity. The difference in the binding ability to the cell membranes well accounts for the cytotoxicity of Abeta(1-40); namely, aggregated beta-sheet Abeta(1-40) gives cytotoxicity higher than random coil Abeta(1-40). Specific binding between Abeta(1-40) and ganglioside GM1 of the raft-like domain in lipid membrane is suggested from a surface plasmon resonance (SPR) experiment.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Membrana Celular/metabolismo , Neuroblastoma/metabolismo , Peptídeos beta-Amiloides/toxicidade , Dicroísmo Circular , Citometria de Fluxo/métodos , Gangliosídeo G(M1)/metabolismo , Humanos , Lipídeos de Membrana/metabolismo , Microdomínios da Membrana/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/toxicidade , Conformação Proteica , Ressonância de Plasmônio de Superfície , Testes de Toxicidade , Células Tumorais Cultivadas
9.
Genes Immun ; 6(2): 162-6, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15674393

RESUMO

A growing body of evidence indicates that genetic factors are involved in an increased risk of infection. We investigated whether mannose-binding lectin (MBL) gene polymorphisms that cause low levels of MBL are associated with the occurrence of major infections in patients, mainly bearing hematological malignancies, after high-dose chemotherapy (HDT) rescued by autologous peripheral blood stem cell transplantation (auto-PBSCT). A retrospective evaluation of 113 patients treated with HDT and auto-PBSCT revealed that the low-producing genotypes, B/B and B/LXA, were associated with major bacterial infection (P=0.0016, OR 7.9). We next performed a nation-wide large-scale study to assess the allele frequency of the MBL coding mutation in a total of 2623 healthy individuals in Japan. The frequency of allele B was estimated to be approximately 0.2, almost the same in seven different areas of Japan. This common occurrence suggests that MBL deficiency may play an important role in the clinical settings of immunosuppression.


Assuntos
Infecções Bacterianas/genética , Predisposição Genética para Doença , Neoplasias Hematológicas/terapia , Lectina de Ligação a Manose/genética , Transplante de Células-Tronco de Sangue Periférico , Polimorfismo Genético , Alelos , Infecções Bacterianas/etiologia , Estudos de Casos e Controles , Feminino , Frequência do Gene , Ligação Genética , Neoplasias Hematológicas/complicações , Humanos , Masculino , Transplante Homólogo
11.
Bone Marrow Transplant ; 32(5): 505-10, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12942097

RESUMO

We investigated effects of variations in the cellular composition of G-CSF-mobilized peripheral blood progenitor cell (G-PBPC) allografts on clinical outcomes of allogeneic PBPC transplantation. We retrospectively analyzed transplanted doses of various immunocompetent cells from 27 HLA-identical sibling donors in relation to engraftment, incidence of graft-versus-host disease (GVHD), and survival. Significant variability was documented in both absolute numbers and relative proportions of CD34+, CD2+, CD3+, CD4(high)+, CD4+25+, CD8(high)+, CD19+, CD56+, and CD56+16+ cells contained in these allografts. Stepwise Cox regression analysis revealed that the CD56+ cell dose was significantly inversely correlated with the incidence of GVHD. Thus, there was a significantly higher incidence of grade II acute GVHD in patients receiving a lower CD56+16+ cell dose (hazard ratio (HR) 0.0090; 95% confidence interval (CI), <0.00001-3.38; P=0.031), a higher incidence of chronic GVHD in those receiving allografts with a lower CD56+16+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.0007; P=0.0035), and a higher incidence of extensive chronic GVHD in those receiving allografts with a lower CD56+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.053; P=0.0083). These results suggest that CD56+ cells in G-PBPC allografts from HLA-identical sibling donors may play an important role in preventing the development of GVHD.


Assuntos
Antígeno CD56/análise , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco de Sangue Periférico/métodos , Adulto , Antígenos CD/análise , Antígeno CD56/imunologia , Feminino , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Mobilização de Células-Tronco Hematopoéticas/métodos , Teste de Histocompatibilidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Análise de Regressão , Estudos Retrospectivos , Irmãos , Transplante Homólogo
12.
Bone Marrow Transplant ; 29(9): 799-801, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12040480

RESUMO

We report two cases of patients with malignant lymphoma who presented with early onset of hemophagocytic syndrome after nonmyeloablative allogeneic peripheral blood stem cell transplantation. Fever and skin eruption developed early after transplantation, and neurological symptoms preceded cytopenia and worsened progressively. Activated macrophages with hemophagocytosis were found in bone marrow of the two patients at day 15 and 56, respectively. The fact that no obvious infectious agents associated with hemophagocytic syndrome were detected, and that serum soluble interleukin-2 receptor concentrations were elevated in the early phase after transplantation, reflecting the activation of donor-derived T cells, suggests that this complication resulted from an alloimmune response.


Assuntos
Histiocitose de Células não Langerhans/etiologia , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Imunologia de Transplantes/imunologia , Adulto , Feminino , Histiocitose de Células não Langerhans/imunologia , Humanos , Linfoma/complicações , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Condicionamento Pré-Transplante/métodos , Transplante Homólogo/efeitos adversos
13.
Opt Express ; 10(11): 469-74, 2002 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-19436383

RESUMO

A tunable wavelength filter based on an asymmetric single-mode grating fiber fabricated by anisotropic CF4 plasma etching is proposed. The reflection wavelength is shown to shift linearly with the degree of curvature of the bent fiber, affording a center wavelength shift of 3.5 nm at 1550 nm. In this region of wavelength shift, the rejection and half-power width of the measured spectra remain almost constant.

14.
Int J Hematol ; 74(3): 347-51, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11721975

RESUMO

A 41-year-old Japanese man complained of a left-sided visual disturbance. Imaging by magnetic resonance angiography revealed a narrowing of the left internal cervical artery. Thus, ticlopidine (Tc) administration was started at a daily dose of 300 mg. However, 2 weeks later, severe thrombocytopenia, fever, nausea, and psychiatric symptoms developed; Tc was therefore discontinued. Based on the diagnostic hallmark of 5 clinical signs, the patient's disease was diagnosed as thrombotic thrombocytopenic purpura (TTP). Daily plasmapheresis was performed for the first 4 days, and the patient's clinical signs gradually improved. Von Willebrand factor-cleaving protease (vWF-CPase) activity in his plasma was less than 3% of that of the control sample at diagnosis, but that value recovered steadily following plasmapheresis. In addition, immunoglobulin G purified from the patient plasma inhibited vWF-CPase activity in normal plasma with a specific activity of 0.8 Bethesda units/mg. No sign of TTP relapse has been noted following cessation of Tc. Thus, it was concluded that the patient developed TTP by producing an inhibitory autoantibody against vWF-CPase activity that was presumably triggered by Tc administration.


Assuntos
Autoanticorpos/imunologia , Imunoglobulina G/imunologia , Metaloendopeptidases/sangue , Inibidores da Agregação Plaquetária/efeitos adversos , Púrpura Trombocitopênica Trombótica/induzido quimicamente , Ticlopidina/efeitos adversos , Proteínas ADAM , Proteína ADAMTS13 , Adulto , Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/tratamento farmacológico , Humanos , Masculino , Inibidores da Agregação Plaquetária/administração & dosagem , Púrpura Trombocitopênica Trombótica/imunologia , Ticlopidina/administração & dosagem
15.
Am J Nephrol ; 21(5): 362-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11684795

RESUMO

Eighty-six patients (59 males and 27 females) diagnosed with steroid-responsive nephrotic syndrome during childhood were identified. The patients were 20-40 years of age (mean 27.0 +/- 5.0) with a mean follow-up period of 19.5 +/- 5.9 years. All patients had been treated with a long-term tapering corticosteroid therapy. Thirty patients had also received a course of cyclophosphamide (2 mg/kg/day for 12 weeks). Sixty-six had achieved sustained remission off corticosteroids, while 20 were still receiving corticosteroids to maintain remission. None of the 86 patients had proteinuria or renal insufficiency at the time of the study. Mean final heights in males and females were similar (-0.51 +/- 1.21 and -0.23 +/- 1.16 standard deviation score). Mean final height of 20 steroid-dependent patients was significantly less than that of 66 in remission off corticosteroids (p < 0.005). Ten cyclophosphamide-treated patients got married and 9 had at least 1 healthy child. In children with steroid-responsive nephrotic syndrome, the need for corticosteroid therapy to maintain remission may be associated with decreased adult height. Patients who received a 12-week course of cyclophosphamide are likely to be normally fertile as adults.


Assuntos
Ciclofosfamida/uso terapêutico , Imunossupressores/uso terapêutico , Rim/patologia , Síndrome Nefrótica/tratamento farmacológico , Adulto , Análise de Variância , Estatura , Feminino , Glucocorticoides/uso terapêutico , Humanos , Masculino , Síndrome Nefrótica/fisiopatologia , Prednisolona/uso terapêutico , Recidiva , Estatísticas não Paramétricas , Resultado do Tratamento
16.
Science ; 293(5532): 1127-9, 2001 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-11498588

RESUMO

About 30% of detected extrasolar planets exist in multiple-star systems. The standard model of planet formation cannot easily accommodate such systems and has difficulty explaining the odd orbital characteristics of most extrasolar giant planets. We demonstrate that the formation of terrestrial-size planets may be insulated from these problems, enabling much of the framework of the standard model to be salvaged for use in complex systems. A type of runaway growth is identified that allows planetary embryos to form by a combination of nebular gas drag and perturbations from massive companions-be they giant planets, brown dwarfs, or other stars.

17.
Nihon Ronen Igakkai Zasshi ; 38(3): 366-71, 2001 May.
Artigo em Japonês | MEDLINE | ID: mdl-11431892

RESUMO

Purpose-related activities are often lost in severe dementia, including oral hygiene habits such as brushing teeth. The aim of this study is to investigate whether patients with severe dementia can be induced to develop an oral hygiene routine through an occupational therapy approach and whether routine training in oral hygiene habits can reduce dental or denture plaque. Six female inpatients in the same room, who had been given diagnosis of multiple cerebral infarction and dementia. The project design included 4 periods a, b1, b2, and c, a and c were observation periods, while b1 and b2 were general approach periods. In the approach periods we held meetings, and made the program for oral hygiene, planning and problem-solving. In the b2 period both direct intervention by the dentists, dental hygienists and occupational therapists reinforced the habit of brushing teeth in subjects and educated care approach guidance. No patient completely resumed routine habit of brushing teeth, but an improvement in brushings was found in four subjects, one case had no change, and in one case brushing deteriorated. The state of oral hygiene showed improvement in periods b1 and b2. Although the adherence of dental plaque decreased in period b2, it increased in period c. Despite the improvement in performance, sufficient improvement in oral disease prophylaxis was not recognized, suggesting the necessity of professional oral health care by dental staff, and of a disciplinary team approach.


Assuntos
Demência/fisiopatologia , Assistência Odontológica para Idosos , Hábitos , Escovação Dentária , Idoso , Humanos
18.
Neuromuscul Disord ; 11(5): 464-9, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11404118

RESUMO

Myocardial involvement is frequently associated with various types of muscular dystrophy and Thallium-201 scintigraphy can show regional myocardial perfusion abnormalities in patients with muscular dystrophy. Myocardial fatty acid metabolism can now be imaged using a radioiodinated branched fatty acid (123I-BMIPP). The present study evaluates myocardial fatty acid metabolism in muscular dystrophy. Twenty-eight patients underwent 123I-BMIPP(BMIPP) and Thallium dual single photon emission tomography. Regional uptake of both tracers was visually analyzed. We also assessed electrocardiography and echocardiography. The results showed that the BMIPP uptake compared to Thallium was smaller in 57% of all patients. BMIPP SPECT images revealed abnormalities in four of eight patients with a normal electrocardiogram. Abnormal BMIPP uptake with normal regional wall motion was evident in nine patients. The size of the region with defective BMIPP uptake was larger than that of asynergic areas detected by echocardiography in 11 patients. In conclusion, muscular dystrophy involves depressed myocardial fatty acid metabolism in larger extent of region than that in perfusion or mechanical abnormality.


Assuntos
Ácidos Graxos/metabolismo , Distrofia Muscular de Duchenne/diagnóstico por imagem , Distrofia Muscular de Duchenne/metabolismo , Miocárdio/metabolismo , Adolescente , Adulto , Idoso , Criança , Ácidos Graxos/farmacocinética , Feminino , Humanos , Radioisótopos do Iodo , Iodobenzenos/farmacocinética , Masculino , Pessoa de Meia-Idade , Distrofias Musculares/diagnóstico por imagem , Distrofias Musculares/metabolismo , Volume Sistólico , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único
19.
Biomed Pharmacother ; 55(2): 96-101, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11293819

RESUMO

We studied intracellular cytokines in monocytes by flow cytometry from 28 patients with hematologic malignancies and solid tumors to analyze the role of monokines in the hematologic recovery phase for peripheral blood stem cell harvest. The patients were divided into three groups: the first group, A, had a documented infection; the second group, B, had fever of unknown origin; and the third group, C, was afebrile. We found an increase in intracellular IL-1alpha, IL-6, IL-8 and TNF-alpha positive monocytes as CD14 positive gated cells cultured with lipopolysaccharide in all groups, but no increase was found with medium only when cultured for 4 h. We also found an increase in intracellular IL-1a, IL-6, IL-8 and TNF-alpha positive monocytes cultured with autologous serum for 4 h, but only in group A. The rate of intracellular cytokine positive cells was higher in monocytes cultured with only autologous serum from group A patients compared to those cells from the other groups; the data concerning IL-1a, IL-6 and TNF-alpha reached statistical significance (P < 0.05). However, increasing intracellular cytokine levels in the control group of patients exhibiting only infectious disease were observed. Thus, it appear that pro-inflammatory intracellular cytokine levels in monocytes are only related to microbial infections.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Receptores de Lipopolissacarídeos/metabolismo , Monocinas/biossíntese , Adulto , Idoso , Antineoplásicos/uso terapêutico , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Monocinas/sangue , Neoplasias/tratamento farmacológico
20.
J Clin Endocrinol Metab ; 86(1): 381-5, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11232028

RESUMO

Nephrogenic diabetes insipidus (NDI) is characterized by resistance of the kidneys to the action of arginine vasopressin (AVP); X-linked recessive NDI is caused by an inactivating mutation of the vasopressin type-2 (V2) receptor. Several missense mutations in the first or second extracellular loop of the V2 receptor have been reported, and some of these mutant receptors were confirmed to have reduced affinities for ligand binding. We detected a novel V2 receptor gene mutation, a substitution of cysteine for arginine-104 (R104C) located in the first extracellular loop of the V2 receptor, in a patient with congenital NDI. Functional analysis by transient expression studies with COS-7 cells showed binding capacity of R104C mutant diminished as 10% of wild type, but binding affinity was strong rather than wild type. In the result of AVP stimulation studies, maximum cAMP accumulation of R104C decreased as 50% of wild type. On the other hand, a designed mutant receptor, substituted serine for arginine-104 as a model of modified R104C mutant receptor removed the influence of the sulfhydryl group in cysteine-104, recovered binding capacity up to 50% of wild type and maximum cAMP accumulation as 82% of wild type. Our study demonstrated that the R104C mutation of the V2 receptor was a cause of NDI. The mechanism of renal resistance to AVP was the reduction of ligand binding, and adenylyl cyclase activation depended on the V2 receptor. In addition, we confirmed that the sulfhydryl group of the cysteine-104 caused most part of R104C mutant receptor dysfunction.


Assuntos
Diabetes Insípido Nefrogênico/genética , Mutação/fisiologia , Receptores de Vasopressinas/genética , Sequência de Aminoácidos/genética , Animais , Sequência de Bases/genética , Células COS , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Receptores de Vasopressinas/metabolismo
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