Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
J Phys Condens Matter ; 32(27): 274001, 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32143205

RESUMO

We have developed a special technique and succeeded to carry out small-angle x-ray scattering measurements for some liquid metal systems. The purpose is to investigate effects of transitions such as liquid-liquid (LLT), liquid-gas (LGT) and metal-nonmetal (MNMT) transitions on mesoscopic density fluctuations in liquids. In liquid Te systems (Se-Te and Ge-Te mixtures), which show continuous LLT accompanying MNMT, parameters of density fluctuations show maxima almost in the middle of the transition, both in strength and spatial size. This work (and Kajihara et al 2012 Phys. Rev. B86 214202) was the first direct observation that density fluctuations exhibit maximum corresponding to LLT. However in this study, we could not clearly separate the effects of LLT and MNMT on the observed density fluctuations. Thus, we also investigated fluid Hg under high pressure and high temperature conditions, which shows MNMT near a critical point of LGT, to investigate how MNMT affects them. We observed distinct density fluctuations; a strength and a correlation length of them show maxima at around a critical isochore of LGT, and the former is basically consistent with a phase diagram (compressibility) of LGT; they do not show any peaks at MNMT region. Precise analysis revealed that MNMT only affects a shift of another parameter, a short-range correlation length. These results in fluid Hg indicate that the density fluctuations are mainly derived from a critical phenomena of LGT and MNMT does not play any critical role on them. We believe that the latter conclusion also holds true for liquid Te systems; MNMT plays no important role on the density fluctuations in liquid Te systems and LLT is the main origin of them.

5.
Curr Med Chem ; 16(33): 4419-44, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19835564

RESUMO

Protein cysteines (cysteinyl residues) play critical roles in biological processes. In the course of protein evolution under oxidizing atmosphere of the Earth, organisms have utilized highly reactive cysteines in many proteins essential for maintenance of life, i.e. enzymes, transcriptional factors, cytoskeletons, and receptors. In some enzymes, sophistical cysteine modification characterizes each catalytic mechanism. In vivo modification of protein cysteines with natural chemical compounds modulates protein functions as a molecular switch. Oxidation/reduction, thiol-disulfide exchange, nitrosylation, sulfuration, thiolation, acylation and prenylation are involved. Some protein cysteines coordinate metals or metal cofactors such as a heme or an iron sulfur cluster to form metalloproteins, serving as sensor proteins, metalloenzymes or transcriptional factors. Information on the in vitro chemical modifications and their reaction specificities of protein cysteines are essential for the investigation of the mechanisms and functions of in vivo protein cysteine modifications. In this review, we also mention historically important knowledge other than recent results on protein cysteine modification and modulation of protein function to fertilize medical proteomics.


Assuntos
Cisteína/química , Proteínas/química , Proteômica/métodos , Acetilação , Alquilação , Biocatálise , Metais/química , Nitrosação , Oxirredução , Prenilação , Proteínas/metabolismo , Compostos de Sulfidrila/química
6.
Nihon Igaku Hoshasen Gakkai Zasshi ; 61(9): 502-7, 2001 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-11577436

RESUMO

The aim of this study was to investigate the usefulness of whole-body MRI(WB-MRI) in the evaluation of cellularity in bone marrow and the distribution of fatty marrow in aplastic anemia. WB-MRI was performed on five patients with aplastic anemia who ranged in age from 62 to 70 years of age, and on four controls with malignant lymphoma who ranged in age from 59 to 67 years. Coronal images were obtained using a body coil with an FOV of 48 cm x 48 cm, and with both fast short T1 inversion recovery(STIR) and spin-echo T1-weighted(T1-WI) in three regions: (1) head to thorax, (2) abdomen to pelvis, and (3) lower extremities. The findings on WB-MRI were compared with those of histological studies of bone marrow at the sternum and the posterior iliac crest. The results were as follows: (1) there was a correlation between the cellularity of histological studies of bone marrow and signal intensity on WB-MRI; (2) WB-MRI could detect the activity of bone marrow; and (3) in a comparison of signal intensity in aplastic anemia and control subjects, there were differences of signal intensity in the central marrow.


Assuntos
Anemia Aplástica/diagnóstico , Medula Óssea/patologia , Imageamento por Ressonância Magnética/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Nihon Koshu Eisei Zasshi ; 48(6): 470-9, 2001 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-11494592

RESUMO

PURPOSE: The purpose of this study was to investigate the actual conditions of childcare and home education among families of female nurses in the P. R. of China. METHODS: The subjects were nurses from 15 hospitals in 3 provinces and 2 autonomous areas. They were surveyed by questionnaire regarding their childcare and home education. It was distributed by the Ministry of Health in the P. R. of China and data were collected between February and April in 1996. RESULTS: A total of 4284 (80.0%) questionnaires were collected. 1. The age of the subjects was between 18 and 62 years old with a mean of 32.9 +/- 9.0 (SD) years 71.4% of them had husbands, whose ages were between 23 and 71 years old, the mean age being 38.3 +/- 8.4 (SD) years. The family types were 63.2% nuclear family and 33.7% extended family, with 3.1% being single. 65.1% of the subjects had children, whose mean number was 1.1 +/- 0.4 (SD). Firstborn children were 49.9% girls and 50.1% boys. 2. The most popular method of infant nutrition was breast-feeding, utilized by 60.1%. The highest rate (67.8%) was in the age group of 25 to 29 years old (P < 0.01). 3. The practice of "swaddling" (wrapping the child so as not to allow movement) was more common in the over 40 year old age group than the under 40 year old group (P < 0.01). Swaddling-practice showed significant differences by area. 4. The rates for children who helped with housework were 50.3% for girls and 46.7% for boys. 5. A number of children between 7 and 18 years old were studying English privately. 6. The greatest expectation of the subjects, for their children aged between 7 and 18 years old, was to study. CONCLUSIONS: 1. Infant nutrition showed significant differences between generations, and swaddling-practice differed with the generation and the area. 2. Although girls help their parents more than boys in Japan, boys and girls equally helped their parents in the P. R. of China. 3. Concerning the topics of private learning and parents expectations, the results were similar to those in Japan.


Assuntos
Educação Infantil/tendências , Enfermeiras e Enfermeiros , Mulheres Trabalhadoras , Adolescente , Adulto , Idoso , Criança , Cuidado da Criança/tendências , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Cell Struct Funct ; 26(5): 253-61, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11831357

RESUMO

Tyrosine kinase activity of v-Src from Rous sarcoma virus (RSV) inhibits the differentiation of quail myoblasts. To clarify the inhibitory mechanism, we focused on the signaling pathways from v-Src. When the activation of the Ras/MAP (mitogen-activated protein) kinase pathway was inhibited by a dominant-negative mutant of Ras or PD98059, a specific inhibitor of p42 MAP kinase kinase, differentiation was restored; muscle specific proteins were expressed and myotubes formed even under active conditions of v-Src. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (P13-kinase), showed no effects on the inhibition by v-Src. These findings suggest that v-Src activates the Ras/MAP kinase signaling pathway, but not the P13-kinase pathway, and inhibits the differentiation. However, the myotubes derived from the dominant-negative Ras did not form actin fibers, suggesting that myofibril assembly is regulated by other pathway(s) from v-Src.


Assuntos
Transformação Celular Neoplásica , Sistema de Sinalização das MAP Quinases/fisiologia , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/enzimologia , Miofibrilas/enzimologia , Proteínas ras/metabolismo , Animais , Vírus do Sarcoma Aviário , Diferenciação Celular , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Regulação da Expressão Gênica , Genes src , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Codorniz , Temperatura , Transfecção , Proteínas ras/genética
9.
Nihon Igaku Hoshasen Gakkai Zasshi ; 60(5): 249-54, 2000 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-10824532

RESUMO

The aim of this study was to investigate the usefulness of whole body MR imaging (WB-MRI) in the detection of bone metastases from breast cancer and to compare the results with those from bone scintigraphy. In 21 patients with suspected bone metastasis from breast cancer, both bone scintigraphy and WB-MRI were performed. With WB-MRI, coronal images were obtained using a body coil in an FOV of 48 cm, and sequences of fast short TI inversion recovery (STIR) and gadolinium-enhanced fast spoiled GRASS (SPGR) were used in three parts: from the head to the thorax, the abdomen to the pelvis, and the lower extremities. Of the total 105 metastatic bone lesions, 65 (61.9%) were detected by bone scintigraphy, 98 (93.3%) by fast STIR, and 74 (70.5%) by fast SPGR. Thus, the detection of bone metastases by WB-MRI was excellent. However, detectability in the ribs was lower for WB-MRI than for bone scintigraphy. Contrast-enhanced MRI was useful in the differentiation of osteosclerotic lesions, in which high signal intensity is rare, pleural effusion, which has high signal intensity on STIR, and bone metastatic lesions. In conclusion, WB-MRI showed high reliability in the detection of bone metastatic lesions from breast cancer.


Assuntos
Neoplasias Ósseas/secundário , Osso e Ossos/diagnóstico por imagem , Neoplasias da Mama/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Neoplasias Ósseas/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Cintilografia , Reprodutibilidade dos Testes
10.
Nihon Igaku Hoshasen Gakkai Zasshi ; 59(9): 470-2, 1999 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-10487060

RESUMO

Preliminary studies were performed to evaluate the usefulness of whole-body magnetic resonance imaging (WB-MRI) in the screening of bone metastases. The fast short TI inversion recovery sequence was the most suitable method because of its minimal image distortion and uniformity of fat suppression in a large field of view. In 4 cases of malignant tumor, the localization of all 8 bone metastases detected with bone scintigraphy (BS) could be clarified with WB-MRI. Furthermore, WB-MRI with fast STIR alone could depict 4 lesions undetected by BS, and WB-MRI combined with contrast enhancement could depict 5 such lesions.


Assuntos
Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Osso e Ossos/patologia , Imageamento por Ressonância Magnética/métodos , Humanos , Aumento da Imagem/métodos
11.
Nihon Igaku Hoshasen Gakkai Zasshi ; 59(7): 325-32, 1999 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-10429431

RESUMO

Peripheral vascular lesions may occur as a result of various clinical problems, cosmetic or dysfunctional causes, or bleeding. In severe cases, coagulopathy and congestive heart failure may occur. Although the efficacy of transarterial embolization (TAE) for arterial vascular lesions is well known, TAE has no effect on low-flow vascular lesions (venous malformations, venous angiomas, and venous components of arteriovenous malformation). Therefore, in such cases, a percutaneous approach is the best method, and we consider sclerotherapy to be the most useful conservative treatment. The primary objective of this study was to confirm the efficacy of percutaneous sclerosing treatment for peripheral low-flow vascular lesions. Lesions were classified on the basis of state of blood flow and morphologic features, and infiltration was classified on the basis of angiographic features and magnetic resonance imaging (MRI) findings. In sclerosing treatment, we used 5% solutions of polidocanol, absolute ethanol, and N-butyl-2-cyanoacrylate (NBCA) as sclerosing agents. Each type of lesion, static or slow-flow, cystic, or localized, showed remarkable improvement after sclerosing treatment with only polidocanol. However, for moderate-to-fast-flow lesions, another sclerosing agent (absolute ethanol/NBCA) was needed. With diffuse infiltrative lesions, surgical repair might be needed, but we recognize the usefulness of sclerosing treatment for functional or cosmetic improvement in these cases.


Assuntos
Doenças Vasculares Periféricas/terapia , Escleroterapia/métodos , Adolescente , Adulto , Criança , Extremidades/irrigação sanguínea , Feminino , Cabeça/irrigação sanguínea , Humanos , Masculino , Pescoço/irrigação sanguínea , Doenças Vasculares Periféricas/fisiopatologia , Polidocanol , Polietilenoglicóis/administração & dosagem , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Soluções Esclerosantes/administração & dosagem
13.
Gan To Kagaku Ryoho ; 23(11): 1479-81, 1996 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-8854785

RESUMO

Since 1992, we have treated 43 patients with head and neck tumors by superselective intra-arterial infusion chemotherapy (SIIC) via femoral artery. In 8 patients among then, operation was performed thereafter with/without radiation therapy (RT). CDDP and/or CBDCA were utilized as the chemotherapeutic modality. Only SIIC or RT showed Grade (Gr.) 0-2b pathological effects on Oboshi-Shimosato classification scheme, while a combination of SIIC and RT exhibited Gr. 2b-4 pathological effects. We conclude that a combination of SIIC and RT was most effective and had induced degeneration or necrotic changes in the tumor tissue.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carboplatina/administração & dosagem , Carcinoma de Células Escamosas/radioterapia , Cisplatino/administração & dosagem , Terapia Combinada , Feminino , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Infusões Intra-Arteriais , Masculino , Pessoa de Meia-Idade
14.
Parasitology ; 113 ( Pt 1): 19-23, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8710411

RESUMO

A low molecular weight factor in a basal medium essential for erythrocytic Plasmodium falciparum development in a serum-free medium using a cell growth-promoting factor derived from adult bovine serum was detected. The factor was hypoxanthine. The optimal hypoxanthine concentration for parasite growth was between 15 and 120 microM. The contribution of hypoxanthine to increased parasite growth was clearly evident in cultures on day 4. Among various low molecular weight supplements tested, adenine, adenosine, AMP, ATP, cyclic AMP, guanine, guanosine, inosine, inosine monophosphate, xanthine, NAD, NADH, NADP, NADPH and deoxyguanosine triphosphate showed a similar effect to that of hypoxanthine in the serum-free culture system. On the other hand, the addition of uric acid, FAD, thymidine, uridine, orotic acid, deoxythymidine triphosphate, deoxycytidine triphosphate, deoxyadenosine triphosphate, ribose-1-phosphate, or ethanolamine was not beneficial to the parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements of the parasite.


Assuntos
Hipoxantinas/metabolismo , Plasmodium falciparum/crescimento & desenvolvimento , Animais , Bovinos , Meios de Cultura Livres de Soro , Humanos , Hipoxantina , Peso Molecular , Nucleotídeos de Purina/química , Nucleotídeos de Purina/metabolismo
15.
Eur J Radiol ; 21(2): 94-9, 1995 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-8850500

RESUMO

A group of 26 patients with carcinoma of the head and neck region was treated by superselective intra-arterial infusion of cisplatin (CDDP)-carboplatin (CBDCA). The tumor locations included the tongue (n = 4), oral base (n = 2), nasopharynx (n = 2), oropharynx (n = 8), hypopharynx (n = 4) and larynx (n = 4). Using the coaxial technique, a microcatheter was placed in the lingual, ascending pharyngeal, facial and superior thyroidal arteries according to the location of the tumor. Under imaging studies, CDDP (50 mg/m2)-CBDCA (300 mg/m2) was infused into the vessel, via injectors at the rate of 12.5 ml/min. One to five injections were given every 4 weeks. During and following the chemotherapy the patients received radiotherapy (n = 22), surgery (n = 4) or both (n = 3). Sixty-six sessions of intra-arterial chemotherapy were given with no major complications. Drug-related systemic side effects were mild. The overall response rate was 96% (complete response (CR) 50% and partial response (PR) 46%). Superselective CDDP-CBDCA combined infusion is feasible, relatively non-toxic, and important as multimodality therapy.


Assuntos
Antineoplásicos/administração & dosagem , Carboplatina/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Quimioterapia do Câncer por Perfusão Regional , Cisplatino/administração & dosagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/efeitos adversos , Carcinoma de Células Escamosas/cirurgia , Cateterismo Periférico/instrumentação , Cisplatino/efeitos adversos , Terapia Combinada , Estudos de Viabilidade , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Neoplasias Hipofaríngeas/tratamento farmacológico , Neoplasias Hipofaríngeas/cirurgia , Infusões Intra-Arteriais , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/cirurgia , Pessoa de Meia-Idade , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/cirurgia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/cirurgia , Neoplasias Orofaríngeas/tratamento farmacológico , Neoplasias Orofaríngeas/cirurgia , Radioterapia Adjuvante , Indução de Remissão , Neoplasias da Língua/tratamento farmacológico , Neoplasias da Língua/cirurgia
18.
Acta Radiol ; 30(5): 535-9, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2611061

RESUMO

The effects of injection of absolute ethanol into the renal artery were investigated in 13 rabbit kidneys previously implanted with VX2 carcinoma. Eight rabbits with implanted tumors served as controls. The effects were evaluated by angiography and histology. Three days after implantation, tumors were demonstrated by angiography as relatively hypovascular areas in the subcapsular cortex of the kidneys. Following angiography, absolute ethanol (0.3 ml/kg) was injected into the renal artery. Repeat angiography with barium sulphate was performed after an additional 3 days (10 ethanol treated animals, 2 controls), 10 days (2 treated, 1 control) or 14 days (1 treated, 0 control). In treated animals the tumors were markedly smaller in comparison with those of the control group. The occlusion procedure, however, did not completely eradicate tumor cells. The histologic study of the implanted tumor confirmed the findings previously reported that viable tumor cells still remained in the peripheral portions of infarcted areas. This study demonstrated the beneficial, though not curative, short-term effects of transcatheter renal artery treatment with absolute ethanol in malignant renal tumors.


Assuntos
Embolização Terapêutica , Etanol/uso terapêutico , Neoplasias Renais/terapia , Artéria Renal , Animais , Linhagem Celular , Etanol/administração & dosagem , Injeções Intra-Arteriais , Transplante de Neoplasias , Coelhos
19.
Radiat Med ; 5(6): 187-90, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3452848

RESUMO

It is well known that patients with pseudo (PHP)- and idiopathic (IHP) hypoparathyroidism are frequently associated with intracranial calcifications. The relative sensitivity of computed tomography (CT) and conventional skull radiography in detecting basal ganglia calcifications was studied in two patients with PHP and six with IHP. CT was more sensitive: the detection rate was 71% (5/7) for CT and 14% (1/7) for skull radiography. Furthermore, patients with more prolonged hypocalcemia showed a higher incidence of calcifications. Thus, CT was useful as a diagnostic technique in the early detection of calcified basal ganglia.


Assuntos
Doenças dos Gânglios da Base/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Hipoparatireoidismo/complicações , Pseudo-Hipoparatireoidismo/complicações , Adolescente , Adulto , Idoso , Doenças dos Gânglios da Base/etiologia , Calcinose/etiologia , Feminino , Humanos , Hipocalcemia/complicações , Masculino , Valor Preditivo dos Testes , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA