RESUMO
A comprehensive review of physics at an [Formula: see text] linear collider in the energy range of [Formula: see text] GeV-3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.
Assuntos
Infecções por Chlamydophila/complicações , Chlamydophila pneumoniae/isolamento & purificação , Degeneração Macular/microbiologia , Idoso , Anticorpos Antibacterianos/análise , Arteriosclerose/complicações , Infecções por Chlamydophila/imunologia , Chlamydophila pneumoniae/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Degeneração Macular/imunologia , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Quantifying mechanisms underlying extracellular signaling by the neurotransmitter dopamine (DA) is a difficult task, particularly in the complex extracellular microenvironment of the intact brain. In this study, two methods for evaluating release and uptake from DA dynamics monitored by real-time voltammetry are described. Both are based on a neurochemical model characterizing electrically evoked levels of DA as a balance between these opposing mechanisms. The theoretical basis of what is called here nonlinear regression and single curve analyses is given. Fitting simulated data tests the reliability of the methods. The two analyses are also compared with an experimental data set describing the effects of pharmacologically inhibiting the DA transporter in the caudate-putamen (CP) and nucleus accumbens (NAc). The results indicate that nonlinear regression and single curve analyses are suitable for quantifying release and uptake mechanisms underlying DA neurotransmission. Additionally, the most important experimental finding of this technical study was the independent confirmation of high affinity (approximately 0.2 microM) DA uptake in the intact striatum.
Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Eletrofisiologia/métodos , Glicoproteínas de Membrana , Modelos Neurológicos , Proteínas do Tecido Nervoso , Terminações Pré-Sinápticas/metabolismo , Transmissão Sináptica/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Cocaína/farmacologia , Corpo Estriado/efeitos dos fármacos , Dopamina/farmacologia , Proteínas da Membrana Plasmática de Transporte de Dopamina , Inibidores da Captação de Dopamina/farmacologia , Estimulação Elétrica/instrumentação , Estimulação Elétrica/métodos , Eletrofisiologia/instrumentação , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Cinética , Masculino , Moduladores de Transporte de Membrana , Proteínas de Membrana Transportadoras/antagonistas & inibidores , Proteínas de Membrana Transportadoras/metabolismo , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Nomifensina/farmacologia , Dinâmica não Linear , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Terminações Pré-Sinápticas/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/efeitos dos fármacosRESUMO
To determine whether Chlamydia pneumoniae (C. pneumoniae) infection is associated with hypertension in Japanese adults, we measured serum levels of IgA (a marker of reinfection) and of IgG (a marker of previous infection) antibodies to C. pneumoniae by enzyme-linked immunosorbent assay in 112 adults including normotensive and untreated hypertensive subjects and in 117 hypertensive subjects who had been receiving treatment for more than 3 years. In 112 adults, positivity rate for IgA was lower (P < .01) in hypertensive than in normotensive or borderline hypertensive subjects. Positivity rates for IgA and IgG together, which indicate persistent infection of C. pneumoniae, were lower (P < .01) in hypertensive than in normotensive subjects. IgA levels were inversely correlated with systolic blood pressure (SBP) (r = 0.530, P = .0001) and with diastolic blood pressure (DBP) (r = 0.398, P = .0001). In the 117 hypertensive subjects treated with medication, positivity rate for IgA was lower (P < .01) in subjects with poor control than in those with good control. Positivity rates for IgA and IgG together were lower (P < 0.01) in the poor control group than in the good or fair control groups. IgA levels were correlated inversely with SBP and DBP. In both 112 adults and 117 hypertensive patients, levels of SBP or DBP were inversely associated with positivity rates for IgA and IgG together in multiple logistic regression analysis. The results suggest an inverse relationship between high blood pressure and C. pneumoniae infection in Japanese adults.
Assuntos
Infecções por Chlamydophila/complicações , Chlamydophila pneumoniae , Hipertensão/microbiologia , Idoso , Anticorpos Antibacterianos/análise , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Chlamydophila pneumoniae/imunologia , Feminino , Humanos , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Imunoglobulina A/análise , Imunoglobulina G/análise , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
The fixation of fractured bone with screws is important for orthopedic surgery, however, rigid fixation often cannot be attained in elderly patients with osteoporosis. Recently, we developed a new injectable, nonresorbable bone cement (CAP) that possesses mechanical and biological properties superior to those of polymethylmethacrylate (PMMA) cement. CAP can directly bond with bone without intervening fibrous tissue, and the peak curing temperature is 46 degrees C. In this study, we assessed the effects of CAP and PMMA cement on the augmentation of screw fixation in vivo. A cancellous screw was placed in the proximal metaphysis of rabbit tibiae. One side of each tibia was randomly selected to be augmented with CAP or PMMA. The contralateral side received a screw without cement (control). Of the 36 rabbits included in this study, 9 rabbits from each group were sacrificed and the tibial constructs retrieved 1 or 3 months after the initial operation. The screws were then pulled out to failure. The values of the pullout force of the screws augmented with CAP and PMMA were higher than those of the control specimens at both 1 month (319 +/- 58 N for CAP vs. 105 +/- 41 N for control; p < 0.05, 284 +/- 100 N for PMMA vs. 132 +/- 71 N for control; p < 0.05) and 3 months (387 +/- 109 N for CAP vs. 196 +/- 107 N for control; p < 0.05, 372 +/- 145 N for PMMA vs. 242 +/- 100 N for control; p > 0.05) after the operation. However, the average increase in the pullout force between CAP and PMMA augmentation was not statistically significant at either time. The values of energy absorption augmented with CAP and PMMA were also higher than those of the control specimens at both 1 month (129 +/- 54 N*mm for CAP vs. 19 +/- 10 N*mm for control; p < 0.05, 145 +/- 95 N*mm for PMMA vs. 28 +/- 21 N*mm for control; p < 0.05) and 3 months (172 +/- 58 N*mm for CAP vs. 44 +/- 41N*mm for control; p < 0.05, 185 +/- 198 N*mm for PMMA vs. 67 +/- 49N*mm for control; p > 0.05) after the operation. However, there were also no significant differences in energy absorption between the two types of cement augmentation. On the other hand, a significant increase was not observed in stiffness among the CAP, PMMA, and respective control groups at either 1 month (626 +/- 133 N/mm for CAP vs. 441 +/- 180 N/mm for control; p < 0.05, 577 +/- 87 N/mm for PMMA vs. 450 +/- 121 N/mm for control; p > 0.05) or 3 months (622 +/- 144 N/mm for CAP vs. 600 +/- 204 N/mm for control; p > 0.05, 633 +/- 175 N/mm for PMMA vs. 630 +/- 168 N/mm for control; p > 0.05) after the operation, except in the average increase between CAP augmentation and its control 1 month after the operation. These results suggested that a cancellous screw fixation augmented with CAP, as well as PMMA, was effective compared with the unaugmented control in vivo. Because of its biocompatibility and low curing temperature, CAP can be used clinically to augment cancellous screw fixation.
Assuntos
Materiais Biocompatíveis , Parafusos Ósseos , Resinas Compostas , Durapatita , Animais , Cimentos Ósseos , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Polimetil Metacrilato , Coelhos , Radiografia , Estresse Mecânico , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/terapiaRESUMO
In the practice of home hospice care, death education for both patient and family is extremely important, although little information on its usefulness is available. In this study, the effects of death education under home hospice care were analyzed for 16 patients who died at home. Death education for the patient and his/her family was given at least once in each phase of care, and at least four times in total. The acceptance of death by the patients was judged according to the way they spent their remaining time, to their attitudes, and to their hope for a life after death. Fourteen of 15 patients appeared to accept their own death. An autopsy was performed in five of the 16 cases. In one case, the doctor recommended an autopsy to the family; in the other cases, it was performed in accordance with the patient's or family's wish. As the goal of death education in home hospice care is the acceptance of death by both patient and family, our methods of death education appear to be effective.
Assuntos
Morte , Serviços de Assistência Domiciliar/organização & administração , Cuidados Paliativos na Terminalidade da Vida/organização & administração , Neoplasias/psicologia , Educação de Pacientes como Assunto/organização & administração , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude Frente a Morte , Cuidadores/educação , Cuidadores/psicologia , Família/psicologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Revelação da VerdadeRESUMO
The crystal structure of FMN-binding protein (FMN-bp) from Desulfovibrio vulgaris Miyazaki F was solved by the multiple isomorphous replacement method and refined to an R factor of 15.1% at 1.3 A resolution. FMN-bp exists in a dimeric form in the crystal, in contrast to the monomeric structure determined by NMR. R.m.s. deviations between the crystal structure and the solution structure are more than 2 A, which implies significant differences. There are some hydrophobic residues in the interface between the two monomers. In particular, Leu122 in the C-terminus has a close contact with the o-xylene moiety of FMN, while solvent molecules may cover the o-xylene moiety in the solution structure.
Assuntos
Proteínas de Bactérias/química , Proteínas de Transporte/química , Desulfovibrio vulgaris/química , Flavoproteínas , Cristalização , Cristalografia por Raios X , Dimerização , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Proteica , Solventes , XilenosRESUMO
"HITAZYME C. pneumoniae" (or "HITAZYME CPN", for short) is a diagnostic reagent that has been recently developed by adopting an ELISA method for detection of anti-Chlamydia pneumoniae (C. pneumoniae) antibodies. When this reagent is used under a current diagnostic standard that has been set as a provisional standard, however, high antibody positive rates are often produced for both IgG and IgA even using the specimens of healthy persons. So, it is difficult to distinguish C. pneumoniae-infected patients from healthy persons. Therefore, this time, we tried to establish a new diagnostic standard by setting up of special cut-off values for a single serum and rise rates of antibody titers for paired sera to improve the accuracy for diagnosis of C. pneumoniae infection. For a single serum testing, we set a special cut-off value at ID 3.00 for both IgG and IgA, so that most healthy persons fall within the range of the "negative" zone. This value was based on the calculation of "Mean+2SD" using measurement results (or IDs) of healthy persons. When this cut-off value was applied, the rate of > or = ID 3.00 for either IgG or IgA was 7.6% for healthy persons, and 64.9% for infected patients. (The rate reached 76.4% when the highest IDs of multiple specimens taken from each patient for this test were used in calculation) As a diagnostic standard for a single serum, therefore, it was defined that: "If ID is 3.00 or greater for IgG and/or IgA, it is highly likely that the case has an acute or a present infection." Using paired sera, we could confirm almost a linear relationship between the results by HITAZYME CPN and those by micro-IF method. Under micro-If method, if the antibody titer increases four times or greater using paired sera, acute infection is diagnosed. As it was found that the four-fold increase in antibody titer corresponds to the increase of 1.35 in ID for IgG and 1.00 for IgA, we defined a diagnostic standard for paired sera as follows: "If ID increases by 1.35 or greater for IgG, and/or if ID increases by 1.00 or greater for IgA, the case may be diagnosed as acute infection."
Assuntos
Anticorpos Antibacterianos/análise , Infecções por Chlamydia/diagnóstico , Chlamydophila pneumoniae/imunologia , Ensaio de Imunoadsorção Enzimática , Testes Sorológicos/normas , Doença Aguda , Adulto , Humanos , Kit de Reagentes para DiagnósticoRESUMO
In order to improve the biological characteristics of DA-3934 (5), a novel gastrin/cholecystokinin (CCK)-B receptor antagonist, phenoxyacetic acid derivatives replacing the N-methyl-N-phenylcarbamoylmethyl moiety of 5 with various alkyl chains have been synthesized and their biological activity evaluated. The relationship between the structure of these compounds and their human gastrin receptor binding affinity showed that there should be the optimal size among the various N-alkyl chains. Also a significant increase in the receptor binding affinity was achieved by several compounds. Among those compounds, 2-[3-[3- [N-cyclohexylmethyl-N-[2-(N-methyl- N-phenylcarbamoylmethoxy)phenyl]carbamoylmethyl]ureido]pheny l]acetic acid (22c) and (+/-)-2-[3-[3-[N-[2-(N-methyl-N- phenylcarbamoylmethoxy)phenyl]-N-(3-methylpentyl)carbamoy lmethyl]ureido] phenyl]acetic acid (22h) exhibited high affinity for human gastrin receptors and were also more potent inhibitors in a pentagastrin-induced gastric acid secretion model than the parent compound, 5. The ED50 values of these compounds when administered intraduodenally to rats were 0.12 and 0.63 mg/kg, respectively.
Assuntos
Acetatos/farmacologia , Fenoxiacetatos/síntese química , Fenoxiacetatos/farmacologia , Compostos de Fenilureia/farmacologia , Receptores da Colecistocinina/antagonistas & inibidores , Acetatos/química , Alquilação , Animais , Células CHO , Fenômenos Químicos , Físico-Química , Cricetinae , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Gastrinas/metabolismo , Humanos , Masculino , Pentagastrina/antagonistas & inibidores , Pentagastrina/farmacologia , Compostos de Fenilureia/química , Ratos , Ratos Sprague-Dawley , Receptor de Colecistocinina B , Relação Estrutura-AtividadeRESUMO
The flavin mononucleotide binding protein from Desulfovibrio vulgaris (Miyazaki F) was crystallized using the vapour-diffusion method. The crystal belongs to the monoclinic space group P21 with unit-cell parameters a = 37.2, b = 84.6, c = 41.1 A, beta = 94.1 degrees, contains two molecules per asymmetric unit and diffracts beyond 1.2 A resolution with a synchrotron radiation X-ray source.
Assuntos
Proteínas de Bactérias/química , Proteínas de Transporte/química , Desulfovibrio vulgaris/química , Mononucleotídeo de Flavina/metabolismo , Flavoproteínas , Cristalização , Cristalografia por Raios X , Conformação ProteicaRESUMO
BACKGROUND AND OBJECTIVES: Chlamydia trachomatis infection is believed to be the most common bacterial sexually transmitted disease (STD) in industrialized countries. The objective of the current study was to assess the recent trend in the prevalence of C. trachomatis in Japan. GOAL OF THIS STUDY: To determine the trend in the seroprevalence for C. trachomatis among pregnant women in Nagasaki, Japan, during the past 10 years. STUDY DESIGN: The seroprevalence for C. trachomatis of 9,652 pregnant women of various ages screened in 1996 and 1997 was compared with those of 275 and 297 stocked samples from 1987 and 1992, respectively. Serum antibodies to C. trachomatis were detected by the enzyme immunoassay. Prospective samples of 33 seropositive cases were also analyzed to determine kinetics of the serum antibody titer. RESULTS: The seroprevalence has decreased in all age groups during the last 10 years. More than 70% of seropositive cases converted to be seronegative within 10 years. CONCLUSION: The prevalence of C. trachomatis has been decreasing among Japanese pregnant women.
Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/imunologia , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Distribuição por Idade , Feminino , Humanos , Japão/epidemiologia , Gravidez , Estudos Retrospectivos , Estudos SoroepidemiológicosRESUMO
We reported previously that bradykinin induces endothelium-dependent relaxation at nanomolar (nM) concentrations in isolated bovine coronary arteries with an intact endothelium. Recently we have found that in the presence of 10 microM indomethacin, femtomolar (fM) concentrations of bradykinin induce endothelium-dependent relaxation in some bovine coronary arteries (approximately 10% of the coronary arteries examined). The present study was designed to characterize the relaxation induced by fM bradykinin. Relaxation was completely abolished by repeated application of fM bradykinin, by 100 microM N(omega)-nitro-L-arginine methyl ester and by 10 microM methylene blue. Relaxation induced by nM bradykinin was partly affected by these treatments. Relaxation induced by both concentrations of bradykinin was inhibited by a B2-kinin receptor antagonist, [Thi5,8, D-Phe7]-bradykinin, in a concentration-dependent manner, but not by a B1-kinin receptor antagonist, des-Arg9, [Leu8]-bradykinin. In the presence of 10 microM captopril, an angiotensin-converting enzyme (ACE) inhibitor, all coronary arteries examined in this experiment showed endothelium-dependent relaxation to fM bradykinin. These results show that some bovine coronary arteries relax in response to fM bradykinin, and this response is mediated predominantly by the release of nitric oxide via stimulation of endothelial B2-kinin receptors. The relaxation may be dependent on ACE activity.
Assuntos
Bradicinina/farmacologia , Vasos Coronários/efeitos dos fármacos , Óxido Nítrico/metabolismo , Vasodilatação/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Antagonistas dos Receptores da Bradicinina , Captopril/farmacologia , Bovinos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Técnicas In Vitro , Azul de Metileno/farmacologia , NG-Nitroarginina Metil Éster/farmacologia , Receptor B1 da Bradicinina , Receptor B2 da BradicininaRESUMO
A series of phenoxyacetanilide derivatives was synthesized and their antagonist activities for human gastrin/cholecystokinin (CCK)-B and CCK-A receptors were evaluated. Among the compounds synthesized, 2-[3-[3-[N-[2-(N-methyl-N-phenylcarbamoylmethoxy)phenyl]-N-(N-meth yl-N- phenylcarbamoylmethyl)carbamoylmethyl]-ureido]phenyl]acetic acid (20i, DA-3934) exhibited high affinity for gastrin/CCK-B receptors and high selectivity over CCK-A receptors. DA-3934 and its methyl ester derivative inhibited pentagastrin-induced gastric acid secretion in rats in a dose-dependent manner.
Assuntos
Acetatos/síntese química , Antiulcerosos/síntese química , Gastrinas/antagonistas & inibidores , Fenoxiacetatos/síntese química , Compostos de Fenilureia/síntese química , Receptores da Colecistocinina/antagonistas & inibidores , Acetatos/farmacologia , Animais , Antiulcerosos/farmacologia , Ligação Competitiva , Células CHO , Cricetinae , Ácido Gástrico/metabolismo , Humanos , Masculino , Pentagastrina/antagonistas & inibidores , Compostos de Fenilureia/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Colecistocinina A , Receptor de Colecistocinina B , Relação Estrutura-AtividadeRESUMO
A novel series of phenoxyacetic acid derivatives was synthesized based on considerations of the three-dimensional structural similarity of YM022 and RP72540. The gastrin/cholecystokinin (CCK)-B and CCK-A receptor antagonist activities of these compounds were evaluated by investigation of their affinities for human gastrin/CCK-B receptors and human CCK-A receptors, respectively. It was found that N-methyl-N-phenyl-2-[2-[N-(N-methyl-N-phenyl-carbamoylmethyl)-N-[2 -[3-(3- methylphenyl)ureido]acetyl]amino]phenoxy]acetamide (20k, DZ-3514) exhibited high affinity for gastrin/CCK-B receptors and high selectivity over CCK-A receptors.
Assuntos
Acetamidas/síntese química , Colecistocinina/antagonistas & inibidores , Gastrinas/antagonistas & inibidores , Compostos de Fenilureia/síntese química , Acetamidas/química , Acetamidas/farmacologia , Animais , Células CHO/efeitos dos fármacos , Colecistocinina/efeitos dos fármacos , Cricetinae , Gastrinas/efeitos dos fármacos , Técnicas de Transferência de Genes , Humanos , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologiaRESUMO
Novel benzophenone derivatives were synthesized and screened for cytotoxic and antitumor activity. Friedel-Crafts condensation was employed to construct the benzophenone skeleton. Among the compounds synthesized, morpholino and thiomorpholino benzophenones 3a-d exhibited potent cytotoxic activity against P388 murine leukemia and PC-6 human lung carcinoma cells in vitro, and compounds 3a, 3c, and 3j, when administered intraperitoneally, showed significant antitumor activity against the malignant ascites caused by intraperitoneal inoculation of P388 cells in mice.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Benzofenonas/síntese química , Benzofenonas/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Células Tumorais CultivadasRESUMO
Studies were conducted with the goal of developing a kit for assaying anti-Chlamydia pneumoniae antibodies in human serum which would enable judging positive cases with high specificity by means of an objective numerical index. Thus, an enzyme-linked immunosorbent assay (ELISA) method employing a C. pneumoniae outer membrane complex protein was established. Elementary bodies (EB) were purified from the YK-41 strain of C. pneumoniae, and subsequent treatment with Sarkosyl, DNase and RNase yielded chlamydial outer membrane complex (COMC). COMC was employed as the antigen and immobilized on 96-well microplates for ELISA method. This ELISA method was used to test 51 serum specimens from patients who had been demonstrated to be positive for C. pneumoniae antigen (throat swab: PCR positive), and the levels of IgG, IgA and IgM antibodies were assayed. For each specimen, comparison was made with the antibody titers determined by the micro immunofluorescence test (Micro-IF method). The results showed good correlation coefficients of 0.950 for IgG, 0.852 for IgA and 0.866 for IgM. In addition, the two assay methods showed the following high agreement rates: 90.2% for IgG, 84.3% for IgA and 82.4% for IgM. Specimens which did not yield the same results with the ELISA method and Micro-IF method were subjected to analysis by Western blot method, and the rates of agreement with the ELISA results were 80% for IgG, 87.5% for IgA and 88.9% for IgM. These data indicate the efficacy of this new ELISA method. Moreover, COMC was reacted with mouse antisera to three Chlamydia species, and the mouse IgG antibody was assayed. Anti-C. pneumoniae antiserum showed the strongest reactivity, whereas weaker reactivity was shown by anti-C. trachomatis antiserum (1/32nd of the reactivity of the anti-C. pneumoniae antiserum) and anti-C. psittaci antiserum (1/4th). In addition, sera from patients infected with C. trachomatis or C. psittaci (Psittacosis) were subjected to the ELISA method using COMC from C. pneumoniae. It was found that the correlation between the ELISA and Micro-IF methods was higher in relation to the anti-C. pneumoniae antibody titer than either the anti-C. trachomatis antibody titer or anti-C. psittaci antibody titer. These findings indicate this new assay kit based on the ELISA method has high specificity for C. pneumoniae.
Assuntos
Anticorpos Antibacterianos/análise , Proteínas da Membrana Bacteriana Externa , Infecções por Chlamydia/diagnóstico , Chlamydophila pneumoniae/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Kit de Reagentes para Diagnóstico , Animais , Especificidade de Anticorpos , Imunofluorescência/métodos , Humanos , CamundongosRESUMO
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder characterized by complement-mediated hemolysis. Abnormal hematopoietic cells from patients with PNH are deficient in glycosylphosphatidylinositol (GPI)-anchored proteins and clonally dominate various hematopoietic lineages in the bone marrow and the peripheral blood. Analysis of many patients with PNH has showed that somatic mutation in the X-linked gene PIG-A is responsible for the GPI-anchor deficiency in PNH. The PIG-A mutation must also be relevant to the clonal dominance of GPI-anchor deficient (GPI-) blood cells because two or more PIG-A mutant clones become dominant in many patients. However, whether the PIG-A mutation alone is sufficient for clonal dominance is not known. To address this question, we generated chimeric mice using Pig-a (the murine homologue of PIG-A) disrupted embryonic stem (ES) cells, in which the animals are chimeric with respect to the surface expression of GPI-anchored proteins. The chimerism of hematopoietic and nonhematopoietic tissues in such mice was always low, suggesting that the higher contribution of Pig-a disrupted GPI- cells had a lethal effect on the chimera. GPI- cells appeared in the peripheral blood of some of the chimeric mice. However, the percentage of GPI- erythrocytes did not increase for 10 months after birth, implying that the Pig-a mutation alone does not immediately cause the clonal dominance of GPI- blood cells; another pathologic or physiologic change(s) in the hematopoietic environments or in the clone itself may be necessary.
Assuntos
Glicosilfosfatidilinositóis/deficiência , Hematopoese/genética , Hemoglobinúria Paroxística/genética , Proteínas de Membrana/genética , Animais , Sequência de Bases , Células Clonais , Genes Dominantes , Glicosilfosfatidilinositóis/genética , Hemoglobinúria Paroxística/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , MutaçãoRESUMO
The relationships between paroxysmal nocturnal hemoglobinuria (PNH), aplastic anemia (AA), and myelodysplastic syndrome (MDS) are not clear. Here we describe a patient, J20, who developed a reciprocal translocation of chromosome 12 and PNH during follow-up of AA. All metaphases in CD59-deficient bone marrow mononuclear cells had the translocation, whereas none of the CD59-deficient cells had it, indicating that the PNH clone coincided with a cell population bearing the chromosomal aberration. We found a somatic single-base deletion mutation in the PIG-A gene of this patient's peripheral blood cells. This is the first patient with PNH with a PNH clone containing a chromosomal translocation.
Assuntos
Anemia Aplástica/genética , Cromossomos Humanos Par 12 , Glicosilfosfatidilinositóis/genética , Hemoglobinúria Paroxística/genética , Translocação Genética , Adulto , Anemia Aplástica/complicações , Sequência de Bases , Medula Óssea/imunologia , Medula Óssea/ultraestrutura , Antígenos CD59/análise , Eritrócitos/imunologia , Eritrócitos/ultraestrutura , Feminino , Granulócitos/imunologia , Granulócitos/ultraestrutura , Hemoglobinúria Paroxística/complicações , Humanos , Cariotipagem , Dados de Sequência MolecularRESUMO
Many membrane proteins are anchored to the cell membrane by glycosylphosphatidylinositol (GPI). The core structure and biosynthesis of the GPI anchor are well conserved in eukaryote cells. We previously cloned a human PIGA gene that participates in GPI anchor biosynthesis. We have now cloned complementary and genomic DNA of Pig-a, the murine homologue of PIGA, and compared its function and gene structure with those of PIGA. The deduced amino acid sequence of mouse PIG-A is 88% identical with that of human PIG-A. Transfection of Pig-a cDNA complemented the defects of both a PIG-A-deficient murine cell line and a PIG-A-deficient human cell line, demonstrating that functions of mouse and human PIG-A are conserved. Like human PIGA, the chromosomal Pig-a gene has six exons and spans approximately 16 kb. Moreover, Pig-a was mapped to X-F3/4, which is syntenic to human Xp22.1, where PIGA is located. Thus, murine Pig-a provides a good animal model to study paroxysmal nocturnal hemoglobinuria, a disease caused by a somatic mutation of PIGA. Database analysis demonstrated that a yeast gene, SPT14, is homologous to Pig-a and PIGA and that these genes are members of a glycosyltransferase gene family.