RESUMO
Recently, possibilities of improving operation speed and force sensitivity in atomic-scale atomic force microscopy (AFM) in liquid using a small cantilever with an electron beam deposited (EBD) tip have been intensively explored. However, the structure and properties of an EBD tip suitable for such an application have not been well-understood and hence its fabrication process has not been established. In this study, we perform atomic-scale AFM measurements with a small cantilever and clarify two major problems: contaminations from a cantilever and tip surface, and insufficient mechanical strength of an EBD tip having a high aspect ratio. To solve these problems, here we propose a fabrication process of an EBD tip, where we attach a 2 µm silica bead at the cantilever end and fabricate a 500-700 nm EBD tip on the bead. The bead height ensures sufficient cantilever-sample distance and enables to suppress long-range interaction between them even with a short EBD tip having high mechanical strength. After the tip fabrication, we coat the whole cantilever and tip surface with Si (30 nm) to prevent the generation of contamination. We perform atomic-scale AFM imaging and hydration force measurements at a mica-water interface using the fabricated tip and demonstrate its applicability to such an atomic-scale application. With a repeated use of the proposed process, we can reuse a small cantilever for atomic-scale measurements for several times. Therefore, the proposed method solves the two major problems and enables the practical use of a small cantilever in atomic-scale studies on various solid-liquid interfacial phenomena.
RESUMO
The structure and protein resistance of oligo(ethylene glycol)-terminated self-assembled monolayers (OEG-SAMs) have been studied intensively using various techniques. However, their molecular-scale surface structures have not been well understood. In this study, we performed molecular-resolution imaging of OH-terminated SAMs (OH-SAMs) and hexa(ethylene glycol) SAMs (EG(6)OH-SAMs) formed on a Au(111) surface in an aqueous solution by frequency modulation atomic force microscopy (FM-AFM). The results show that most of the ethylene glycol (EG) chains in an EG(6)OH-SAM are closely packed and well-ordered to present a molecularly flat surface even in an aqueous solution. In addition, we found that EG(6)OH-SAMs have nanoscale defects, where molecules take a disordered arrangement with their molecular axes parallel to the substrate surface. We also found that the domain size (50-200 nm) of an EG(6)OH-SAM is much larger than that of OH-SAMs (10-40 nm). These findings should significantly advance molecular-scale understanding about the surface structure of OEG-SAMs.
RESUMO
Recent advancement of dynamic-mode atomic force microscopy (AFM) for liquid-environment applications enabled atomic-scale studies on various interfacial phenomena. However, instabilities and poor reproducibility of the measurements often prevent systematic studies. To solve this problem, we have investigated the effect of various tip treatment methods for atomic-scale imaging and force measurements in liquid. The tested methods include Si coating, Ar plasma, Ar sputtering and UV/O3 cleaning. We found that all the methods provide significant improvements in both the imaging and force measurements in spite of the tip transfer through the air. Among the methods, we found that the Si coating provides the best stability and reproducibility in the measurements. To understand the origin of the fouling resistance of the cleaned tip surface and the difference between the cleaning methods, we have investigated the tip surface properties by x-ray photoelectron spectroscopy and contact angle measurements. The results show that the contaminations adsorbed on the tip during the tip transfer through the air should desorb from the surface when it is immersed in aqueous solution due to the enhanced hydrophilicity by the tip treatments. The tip surface prepared by the Si coating is oxidized when it is immersed in aqueous solution. This creates local spots where stable hydration structures are formed. For the other methods, there is no active mechanism to create such local hydration sites. Thus, the hydration structure formed under the tip apex is not necessarily stable. These results reveal the desirable tip properties for atomic-scale AFM measurements in liquid, which should serve as a guideline for further improvements of the tip treatment methods.
RESUMO
In this study, we have investigated the performance of liquid-environment FM-AFM with various cantilevers having different dimensions from theoretical and experimental aspects. The results show that reduction of the cantilever dimensions provides improvement in the minimum detectable force as long as the tip height is sufficiently long compared with the width of the cantilever. However, we also found two important issues to be overcome to achieve this theoretically expected performance. The stable photothermal excitation of a small cantilever requires much higher pointing stability of the exciting laser beam than that for a long cantilever. We present a way to satisfy this stringent requirement using a temperature controlled laser diode module and a polarization-maintaining optical fiber. Another issue is associated with the tip. While a small carbon tip formed by electron beam deposition (EBD) is desirable for small cantilevers, we found that an EBD tip is not suitable for atomic-scale applications due to the weak tip-sample interaction. Here we show that the tip-sample interaction can be greatly enhanced by coating the tip with Si. With these improvements, we demonstrate atomic-resolution imaging of mica in liquid using a small cantilever with a megahertz-order resonance frequency. In addition, we experimentally demonstrate the improvement in the minimum detectable force obtained by the small cantilever in measurements of oscillatory hydration forces.
RESUMO
Neurotoxicity is one of the major effects of tributyltin (TBT). The effects on the next generation of F(1) rats exposed to TBT via the placenta and their dams' milk may be stronger than those on adults. Pregnant Wister rats were exposed to TBT at 0 and 125 ppm in their food. Half of the female F(1) rats in both groups were exposed to TBT at 125 ppm in their food from 9 to 15 weeks of age. Female F(1) rats were divided into the following groups: the control-control (CC) group, with no exposure; the TBT-control (TC) group, exposed to TBT via the placenta and their dams' milk; the control-TBT (CT) group, exposed to TBT via their food from 9 to 15 weeks of age; and the TBT-TBT (TT) group, exposed to TBT via the placenta, their dams' milk, and their food (n = 10/group). After administration, an open-field test and prepulse inhibition (PPI) test were performed at 15 weeks of age. The mean body weights of the TC and TT groups were significantly lower than that of the CC group from 9 to 15 weeks of age. The mean relative thymus weight of the TC and TT groups was significantly lower than that of the CC group. In the open-field test, a marked decrease in the total locomotion distance was observed in the TT group. The mean values in the TT and TC groups were significantly lower than that in the CC group. For the locomotion distance between 15 and 20 min, the mean values in the CT, TC, and TT groups were significantly lower than that in the CC group. The mean locomotor distance between 25 and 30 min in the TT group was significantly lower than that in the CC and TC groups. The mean values of instances of wall rearing in the TC, CT, and TT groups were significantly lower than that in the CC group. The mean value of face washing or body washing in the TT group was significantly lower than that in the CT group. There were no significant differences in indexes of the PPI test. Exposure to TBT via the placenta and their dams' milk inhibited the development of F(1) rats, which continued after weaning. Inhibition of the rats' activity induced by exposure to TBT via the placenta and their dams' milk and/or via their food was suggested. The effects were most evident in the TT group.
Assuntos
Comportamento Animal/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Exposição Materna/efeitos adversos , Atividade Motora/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Compostos de Trialquitina/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/psicologia , Ratos , Ratos WistarRESUMO
The specific antiserum against a type of ferritin that is especially common to leukemia cells and the placenta was used to test, by countercurrent immunoelectrophoresis, sera from humans with various diseases. The best results were obtained with leukemia; patients with chronic myelogenous leukemia in blastic phase, acute myelogenous leukemia, lymphogenous leukemia, and unclassifiable juvenile leukemia frequently showed a positive reaction, but patients with chronic myelogenous leukemia in static phase did not. The average incidence of positive reaction among all leukemia patients was 54.0%. Patients with other malignant tumors (i.e., multiple myeloma, malignant lymphoma and carcinomas of the stomach, rectum, and liver) also often showed a positive reaction. The average incidence of positive reaction among all the patients with malignant diseases of the hematopoietic system, except for leukemia, was 34.3%, and that among patients with nonhematologic malignant neoplasms was 36.8%. However, the incidence of a positive reaction in patients with benign diseases and healthy individuals was less than 3%.
Assuntos
Ferritinas/imunologia , Leucemia/sangue , Neoplasias/diagnóstico , Contraimunoeletroforese , Humanos , Leucemia Linfoide/diagnóstico , Leucemia Mieloide/diagnóstico , Leucemia Mieloide Aguda/diagnóstico , Neoplasias Hepáticas/diagnóstico , Linfoma/diagnóstico , Mieloma Múltiplo/diagnóstico , Placenta/imunologia , Neoplasias Retais/diagnóstico , Neoplasias Gástricas/diagnósticoRESUMO
To clarify the pathogenesis of insulitis in the nonobese diabetic (NOD) mouse, an animal model for human insulin-dependent diabetes mellitus, T-lymphocyte-depleted NOD mice (B mice) were adoptively transferred with spleen and lymph node cells from cyclophosphamide-treated NOD mice after separating the cells with monoclonal antibodies against various T-lymphocyte surface antigens plus complement. Light-microscopic and immunohistochemical studies were also performed to investigate the lymphocytic infiltrations. The incidence of insulitis detected in B mice was much lower when compared with that of the lesion naturally occurring in the NOD mouse. However, higher incidence of insulitis was inducible in B mice by transferring unfractionated lymphoid cells from NOD mice. When the Thy1+ cell-depleted fraction was transferred into the B mice, no increase in the incidence of insulitis was observed. The Lyt1+ or L3T4+ cell-eliminated fraction was also unable to transfer insulitis. Conversely, donor cells depleted of Lyt2+ components successfully induced insulitis in the recipient B mice. These data were consistent with the immunohistochemical study, which showed that the main phenotype of the cells infiltrating the islets was L3T4+. These results suggest the importance of L3T4+Lyt2- T-lymphocytes in the pathogenesis of insulitis in NOD mice.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Imunização Passiva , Ilhotas Pancreáticas , Linfócitos T/transplante , Animais , Doenças Autoimunes/etiologia , Diabetes Mellitus/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Feminino , Imuno-Histoquímica , Linfonodos/citologia , Linfonodos/transplante , Depleção Linfocítica , Masculino , Camundongos , Camundongos Mutantes , Obesidade , Pancreatopatias/etiologia , Baço/citologia , Baço/transplante , Linfócitos T/patologiaRESUMO
To study the role of interferon-gamma (IFN gamma), which is released from activated lymphocytes in the development of lymphocytic thyroiditis, we investigated the effects of IFN gamma on the morphology of mouse thyrocytes, using scanning electron microscopy. Thyrocytes were cultured in monolayers for 5-7 days and incubated with TSH (10 mU/ml) for 1 h before fixation. IFN gamma (200 U/ml) was added to the culture medium for 1 h to 5 days before TSH stimulation. Coculture of thyrocytes with IFN gamma for more than 24 h inhibited TSH-induced morphological changes in the thyrocytes; IFN gamma inhibited the increase in the number of and elongation of microvilli and the appearance of pseudopods. IFN gamma also reduced the number of actin filaments in thyrocytes, as confirmed by immunofluorescence photometry. These results suggest that IFN gamma inhibits the morphological response of thyrocytes to TSH stimulation by the reduction of actin filaments.
Assuntos
Actinas/metabolismo , Interferon gama/farmacologia , Microvilosidades/ultraestrutura , Pseudópodes/ultraestrutura , Glândula Tireoide/ultraestrutura , Tireotropina/farmacologia , Animais , Células Cultivadas , Epitélio/efeitos dos fármacos , Epitélio/ultraestrutura , Feminino , Imunofluorescência , Queratinas/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Glândula Tireoide/efeitos dos fármacosRESUMO
The effects of interferon-gamma (IFN gamma) on the morphology of thyroid follicles and the expression of major histocompatibility complex (MHC) class II antigens were examined. The thyroid follicles were suspended in RPMI-1640 containing 10% fetal calf serum with or without IFN gamma (200 U/ml). After culture for 5 days, follicles were incubated in the presence of TSH (10 mU/ml) for 1 h and fixed for electron microscopic and immunohistochemical examination. Regardless of the presence of IFN gamma, suspended follicles became inverted within 5 days. However, MHC class II antigens were expressed only in inverted follicles cultured with IFN gamma. In inverted follicles cultured without IFN gamma, TSH stimulation induced remarkable morphological changes, such as elongation of microvilli and an appearance of pseudopods. On the other hand, the follicles cultured with IFN gamma showed poor response to TSH. Thus, IFN gamma induced the expression of MHC class II antigens of cultured thyroid follicles and inhibited TSH-induced morphological changes in the cells.
Assuntos
Antígenos de Histocompatibilidade Classe II/análise , Interferon gama/farmacologia , Glândula Tireoide/ultraestrutura , Tireotropina/farmacologia , Animais , Técnicas de Cultura , Masculino , Camundongos , Camundongos Endogâmicos C3H , Microscopia Eletrônica de Varredura , Suspensões , Glândula Tireoide/imunologiaRESUMO
A considerable number of thyrocytes in patients with autoimmune thyroiditis ectopically express HLA-DR antigen. Furthermore, it has been reported that interferon-gamma-induced DR-positive thyrocytes in vitro secrete less thyroid hormone in response to TSH stimulation compared with DR-negative ones. However, the function of the intrinsically DR-positive thyrocytes is unknown. To evaluate their function, we stained by immunofluorescence for both DR antigen and thyroid peroxidase (TPO) in thyroid epithelial cells from patients with Graves' disease. We also measured the quantity of DR antigen and TPO using fluorescent photometry. The content of TPO was not significantly reduced in DR-positive thyrocytes compared with that in DR-negative thyrocytes. The TPO content is one measure of thyrocyte function. There was no significant difference between DR-positive and DR-negative thyrocytes. In conclusion, the function of DR-positive thyrocytes in vivo was not suppressed compared with that of DR-negative thyrocytes.
Assuntos
Doença de Graves/enzimologia , Doença de Graves/imunologia , Antígenos HLA-DR/imunologia , Iodeto Peroxidase/metabolismo , Glândula Tireoide/enzimologia , Glândula Tireoide/imunologia , Adulto , Feminino , Imunofluorescência , Doença de Graves/cirurgia , Antígenos HLA-DR/análise , Humanos , Imuno-Histoquímica , Linfócitos/imunologia , MasculinoRESUMO
To clarify the role of interferon-gamma (IFN gamma) in autoimmune thyroid diseases, we investigated the effects of IFN gamma on the content of thyroid peroxidase (TPO) and the expression of HLA-DR antigens in cultured normal human thyrocytes. The effect of TSH on the action of IFN gamma was investigated. Immunofluorescence staining and photometric analysis showed that IFN gamma not only induced the expression of DR antigen, but also reduced the content of TPO in a concentration-dependent manner. The addition of TSH increased the content of TPO and enhanced the IFN gamma-induced expression of DR antigen. IFN gamma also inhibited the increase in TPO content induced by TSH. Thus, complex interactions appear to exist between IFN gamma and TSH or thyroid-stimulating antibodies in the modulation of hormone secretion and autoimmune phenomena in the thyroid.
Assuntos
Interferon gama/farmacologia , Iodeto Peroxidase/metabolismo , Glândula Tireoide/enzimologia , Tireotropina/farmacologia , Adenoma/enzimologia , Adenoma/cirurgia , Adulto , Células Cultivadas , Criança , Feminino , Imunofluorescência , Antígenos HLA-DR/análise , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/enzimologia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Tireotropina/antagonistas & inibidoresRESUMO
Anaplastic thyroid carcinoma (ATC) is usually associated with a poor prognosis, with most patients dying within a few months. The mechanism of its carcinogenesis is unclear, and its rapid growth and spread often prevent effective surgical therapy. Thus, chemotherapy is necessary. However, ATC is often resistant to anticancer drugs. Therefore, prediction of chemosensitivity is important in selecting appropriate treatment. In this study, after the establishment of three cell lines (K119, KOA2, and IAA) from patients with ATC, we analyzed them for abnormalities in certain oncogenes (myc, ras, ret, and c-erbB2) and the p53 tumor suppressor gene. Only one of three cell lines (KOA2) had a N-ras mutation [codon 61 CAA(Gln)-->CGA(Arg)] and a p53 gene mutation [exon 6 codon 192 Caa(Gln)-->TAG(stop)]. We also investigated their in vitro drug sensitivity and compared it with clinical chemosensitivity, retrospectively. In vitro drug sensitivity was determined using an adhesive tumor cell culture system. Only the K119 cells were sensitive to adriamycin and cisplatin in vitro. The other two were resistant to them in vitro. These results paralleled the clinical responses. We also evaluated the in vitro drug sensitivity of a poorly differentiated thyroid carcinoma cell line (SMP) and papillary thyroid carcinoma cell lines (NPA). None of the five cell lines expressed the multidrug resistance gene (mdr-1). In conclusion, we established ATC cell lines that are suitable models for characterizing the nature of multidrug resistance and carcinogenesis.
Assuntos
Carcinoma/tratamento farmacológico , Carcinoma/genética , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Mutação , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/genética , Idoso , Sequência de Bases , Cisplatino/uso terapêutico , Primers do DNA , Doxorrubicina/uso terapêutico , Feminino , Genes p53/genética , Genes ras/genética , Humanos , Pessoa de Meia-Idade , Sondas de Oligonucleotídeos , Oncogenes/genética , Estudos Retrospectivos , Células Tumorais CultivadasRESUMO
A case of immunoglobulin E (IgE) myeloma with clinical features of "classic" myeloma is presented. Skeletal roentgenograms showed osteoporosis and compression fractures of the vertebrae but no osteosclerosis. Protein analyses revealed an M component of the IgE kappa type with a concentration of 3.1 g/dl. Although morphologic examination revealed that the plasma cells were not so differentiated, well-developed Golgi apparatus and abundant rough-surfaced endoplasmic reticulum were observed. An indirect immunofluorescence technique showed characteristic apple green fluorescence. The E myeloma protein of our patient had no antibody activity. Treatment with melphalan or cyclophosphamide resulted in a decrease in the serum IgE level and in the level of Bence Jones protein in the urine. The clinical and laboratory features of IgE myeloma were summarized and compared with those of other classes of myeloma.
Assuntos
Imunoglobulina E/análise , Mieloma Múltiplo/imunologia , Proteínas do Mieloma/análise , Idoso , Proteína de Bence Jones/urina , Ciclofosfamida/uso terapêutico , Feminino , Humanos , Masculino , Melfalan/uso terapêutico , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico por imagem , Mieloma Múltiplo/ultraestrutura , Plasmócitos/ultraestrutura , RadiografiaRESUMO
PURPOSE: The main purpose of this study was to determine influential factors related to minor leukoencephalopathy (LEP) caused by moderate-dose methotrexate (MTX) and prophylactic cranial radiotherapy (CRT) in childhood hematopoietic malignancies. We also compared the incidence of LEP following this treatment to that reported in the literature following treatment with high-dose MTX alone. METHODS AND MATERIALS: Thirty-eight pediatric patients of hematopoietic malignancies (37 acute lymphoblastic leukemias, 1 non-Hodgkin lymphoma) who were given CRT (18-24 Gy) as well as prophylactic intrathecal and per os MTX were studied for leukoencephalopathy by magnetic resonance (MR) imaging. All the patients were free from grave neuropsychiatric disturbances. The data were examined to elucidate the influential ones of five factors (patients' age, doses of intrathecal and per os MTX, dose of CRT, interval between treatment, and MR study) to develop LEP using multiple regression analysis. To compare the effect of moderate-dose MTX and prophylactic CRT on LEP to that of high-dose MTX alone, we conducted literature review. RESULTS: Seven out of 38 patients (18%) developed LEP. From multiple regression analysis and partial correlation coefficients, the age and CRT dose seemed influential in the subsequent development of LEP. The incidence of LEP following treatment with moderate-dose MTX and prophylactic CRT appears to be less than that reported in the literature following treatment with intravenous high-dose MTX. However, even moderate-dose MTX in combination with CRT can result in a significant incidence of MR-detectable LEP, particularly in children 6 years of age or younger receiving 24 Gy. CONCLUSION: Leukoencephalopathy was caused by moderate-dose MTX and prophylactic CRT in pediatric patients, probably less frequently than by high-dose MTX treatment alone. The influential factors were patient's age and CRT dose.
Assuntos
Dano Encefálico Crônico/etiologia , Encéfalo/efeitos dos fármacos , Encéfalo/efeitos da radiação , Irradiação Craniana/efeitos adversos , Linfoma não Hodgkin/terapia , Metotrexato/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Dano Encefálico Crônico/induzido quimicamente , Dano Encefálico Crônico/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Análise de RegressãoRESUMO
A noninvasive biochemical testing method for early detection and monitoring the condition of cardiac complications in hemodialysis (HD) patients would be useful and might lead to improved survival. The aim of this study is to clarify the pathophysiological significance of plasma brain natriuretic peptide (BNP) levels in HD patients with and without coronary artery disease (CAD). We measured plasma atrial natriuretic peptide (ANP) and BNP levels on Monday, Wednesday, and Friday before and after HD in 28 consecutive patients who underwent HD three times weekly. In addition, we measured plasma ANP and BNP levels in 21 HD patients with CAD and 27 HD patients without CAD and studied the relationships between BNP levels and cardiac function and clinical variables. Plasma ANP levels significantly decreased after HD on Monday, Wednesday, and Friday, and predialysis plasma ANP levels on Monday were significantly greater than those on other days. Plasma BNP levels did not change after HD on Monday; however, they significantly decreased after HD on Wednesday and FRIDAY: Predialysis plasma BNP levels on Monday were greater than those on other days, and postdialysis plasma BNP levels on Monday were greater than predialysis plasma BNP levels on WEDNESDAY: Plasma BNP levels in HD patients with CAD were significantly greater than those in HD patients without CAD and significantly correlated with left ventricular (LV) ejection fraction (r = -0.69), end-diastolic volume index (r = 0.59), and end-systolic volume index (r = 0.84) determined by left ventriculography. Conversely, plasma BNP levels in HD patients without CAD significantly correlated with LV mass index (r = 0.54) determined by echocardiography and mean systolic blood pressure (r = 0.72) determined by 48-hour ambulatory blood pressure monitoring. These results suggest the following: (1) plasma BNP levels before and after HD in chronic HD patients directly correlate with the degree of body fluid retention, and the day of the week on which the sample is obtained should be considered for its evaluation; (2) plasma BNP levels reflect LV function in HD patients with CAD; and (3) plasma BNP levels reflect LV mass and blood pressure in HD patients without CAD.
Assuntos
Falência Renal Crônica/terapia , Peptídeo Natriurético Encefálico/sangue , Diálise Renal , Adulto , Idoso , Fator Natriurético Atrial/sangue , Pressão Sanguínea/fisiologia , Doença das Coronárias/sangue , Doença das Coronárias/complicações , Doença das Coronárias/fisiopatologia , Feminino , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
We studied a family in which thyroid neoplasms appeared to occur through genetic inheritance. Six blood relations, including the two probands, had thyroid carcinoma, and six others had benign thyroid tumors. When both parents had a thyroid neoplasm, their children frequently had thyroid neoplasms; this was confirmed through two generations of this family. To clarify the mechanism of inheritance, we performed chromosomal analysis, Southern blot analysis of three variable number of tandem repeats markers and HLA typing on two probands, and examined their RET proto-oncogenes, and p53 and RB tumor suppressor genes. We could not find any positive data on genetic analysis, although our data were limited. In conclusion, we studied a family in which thyroid neoplasms have occurred partly through genetic inheritance, although environmental factors may have influenced the occurrence of thyroid diseases. A search for a predisposing gene, using the microsatellite technique, is required to clarify the gentic factors involved.
Assuntos
Adenoma/genética , Proteínas de Drosophila , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Southern Blotting , Mapeamento Cromossômico , Feminino , Genes do Retinoblastoma/genética , Genes p53/genética , Antígenos HLA/análise , Antígenos HLA/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-ret , Receptores Proteína Tirosina Quinases/genética , Sequências Repetitivas de Ácido NucleicoRESUMO
Certain strains of Streptococcus sanguis and group-H streptococci have been shown to have similar physiological properties and serological specificities. Serological studies revealed that serotype-III S. sanguis shared a common antigen with the so-called "British" group-H streptococci, but not with the "American" group-H streptococci. Serotype-III antigen was extracted in cold 5% trichloroacetic acid from isolated cell walls of S. sanguis ATCC 10558, and purified chromatographically. The purified serotype-III antigen consisted of neutral and amino sugars and some phosphorus, and was negatively charged. Hapten inhibition of the quantitative precipitin reaction between serotype-III antigen and antiserum indicated the strong possibility of alpha-glucosidic linkages being an immunodeterminant of the antigen.
Assuntos
Antígenos de Bactérias/imunologia , Streptococcus sanguis/imunologia , Streptococcus/imunologia , Antígenos de Bactérias/análise , Antígenos de Bactérias/isolamento & purificação , Carboidratos/análise , Epitopos , Imunodifusão , Sorotipagem , Streptococcus/classificação , Streptococcus sanguis/classificaçãoRESUMO
The ultrastructure of extracellular polysaccharides produced in colonies by two clinical isolates and that of a nitrosoguanidine-induced mutant of serotype c Streptococcus mutans with different polysaccharide-synthesizing abilities were compared electron-microscopically. A large amount of polysaccharide was produced from sucrose by colonies of typical serotype c strain MT8148R and a clinical variant MT6801R with an enhanced fructan-synthesizing ability. Transmission electron-microscopy (TEM) revealed that the polysaccharides consisted of three structural components, i.e., globular, single-stranded filamentous, and double-stranded fibrillar structures. These structures were ascribed to production of fructan, water-soluble glucan, and water-insoluble glucan, respectively. On the other hand, two kinds of structures, a globular body and an amorphous substance, were observed by scanning electron-microscopy (SEM). The former was composed of fructan, while the latter contained a mixture of water-soluble and water-insoluble glucans which formed filamentous and double-stranded fibrillar structures under TEM. Very small quantities of polysaccharides were formed in colonies of mutant NG7183, which was derived from S. mutans MT6801R. This strain was found to possess low glucan- and no fructan-synthesizing abilities. The polysaccharides produced in colonies of mutant NG7183 were composed only of filamentous and double-stranded fibrils under TEM. A small amount of amorphous substance was observed by SEM in colonies of NG7183.
Assuntos
Polissacarídeos Bacterianos , Streptococcus mutans/ultraestrutura , Dextranase , Glucosiltransferases/metabolismo , Hexosiltransferases/metabolismo , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Streptococcus mutans/classificação , Streptococcus mutans/enzimologiaRESUMO
In patients with malignant lymphomas, a sarcoid reaction is occasionally observed. However, lymphoma-related granulomas with caseous necrosis are rare. We describe such a case of T-cell gastric lymphoma that was difficult to diagnose. A 50-year-old man was referred to our hospital because of abnormal gastric endoscopic findings: hypertrophic folds with narrowing of the gastric lumen and multiple ulcers in the body. Gastric biopsy specimens showed non-specific inflammation. An open biopsy of the enlarged gastric regional lymph nodes was performed. The sections revealed effacement of the normal architecture and replacement by numerous epithelioid granulomas accompanied by Langhan's type giant cells with or without central caseous necrosis, strongly suggesting tuberculosis. However, mycobacteria and other causative organisms were not detected, and an anti-tuberculous regimen was ineffective. Repeat gastric biopsies were performed and, finally, atypical lymphocytes were observed infiltrating the mucosa. The patient was diagnosed with gastric T-cell lymphoma based on the results of immunohistochemical stainings. After chemotherapy, a total gastrectomy was performed. The diagnosis of gastric T-cell lymphoma with a sarcoid reaction was confirmed by histological findings of the sections. Namely, the gastric wall was replaced by atypical lymphocytes showing the phenotype of helper T cells, admixed with epithelioid granulomas with Langhan's type giant cells. Thus, this case suggests that regional lymph nodes in gastric lymphomas may be present as epithelioid granulomas with caseous necrosis, mimicking tuberculosis.
Assuntos
Granuloma de Células Gigantes/etiologia , Linfoma de Células T/diagnóstico , Neoplasias Gástricas/diagnóstico , Antituberculosos/uso terapêutico , Biópsia , Quimioterapia Adjuvante , Terapia Combinada/métodos , Diagnóstico Diferencial , Gastrectomia , Células Gigantes de Langhans , Granuloma de Células Gigantes/patologia , Humanos , Linfoma de Células T/complicações , Linfoma de Células T/terapia , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/complicações , Neoplasias Gástricas/terapia , Tuberculose dos Linfonodos/diagnóstico , Tuberculose dos Linfonodos/tratamento farmacológicoRESUMO
Graves' disease (GD), myasthenia gravis (MG), and polymyositis (PM) are organ-specific autoimmune diseases. The association between GD and MG is well known, and an association between MG and PM has been reported. However, only one patient with all three diseases has been reported. We describe a patient with GD and PM developing 6 and 29 years, respectively after the onset of MG. This case suggests that the expression of autoimmunity occurred over a prolonged period of time and these organ-specific autoimmune diseases may be induced by a similar mechanism.