Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nature ; 531(7595): 480-4, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-27008966

RESUMO

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon and the bombardment history of the early Solar System.

2.
Nature ; 491(7423): 244-8, 2012 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-23135471

RESUMO

Palaeomagnetic studies of Palaeoproterozoic to Cretaceous rocks propose a suite of large and relatively rapid (tens of degrees over 10 to 100 million years) excursions of the rotation pole relative to the surface geography, or true polar wander (TPW). These excursions may be linked in an oscillatory, approximately coaxial succession about the centre of the contemporaneous supercontinent. Within the framework of a standard rotational theory, in which a delayed viscous adjustment of the rotational bulge acts to stabilize the rotation axis, geodynamic models for oscillatory TPW generally appeal to consecutive, opposite loading phases of comparable magnitude. Here we extend a nonlinear rotational stability theory to incorporate the stabilizing effect of TPW-induced elastic stresses in the lithosphere. We demonstrate that convectively driven inertia perturbations acting on a nearly prolate, non-hydrostatic Earth with an effective elastic lithospheric thickness of about 10 kilometres yield oscillatory TPW paths consistent with palaeomagnetic inferences. This estimate of elastic thickness can be reduced, even to zero, if the rotation axis is stabilized by long-term excess ellipticity in the plane of the TPW. We speculate that these sources of stabilization, acting on TPW driven by a time-varying mantle flow field, provide a mechanism for linking the distinct, oscillatory TPW events of the past few billion years.

3.
J Histochem Cytochem ; 49(6): 739-48, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11373320

RESUMO

Apolipoprotein A-II (apoA-II), an apolipoprotein in serum high-density lipoprotein, is a precursor of mouse senile amyloid fibrils. The liver has been considered to be the primary site of synthesis. However, we performed nonradioactive in situ hybridization analysis in tissue sections from young and old amyloidogenic (R1.P1-Apoa2C) and amyloid-resistant (SAMR1) mice and revealed that other tissues in addition to the liver synthesize apoA-II. We found a strong hybridization signal in the basal cells of the squamous epithelium and the chief cells of the fundic gland in the stomach, the crypt cells and a small portion of the absorptive epithelial cells in the small intestine, the basal cells of the tongue mucosa, and the basal cells of the epidermis and hair follicles in the skin in both mouse strains. Expression of apoA-II mRNA in those tissues was also examined by RT-PCR analysis. Immunolocalization of apoA-II protein also indicated the cellular localization of apoA-II. ApoA-II transcription was not observed in the heart. Amyloid deposition was observed around the cells expressing apoA-II mRNA in the old R1.P1-Apoa2C mice. These results demonstrate that the apoA-II mRNA is transcribed and translated in various extrahepatic tissues and suggest a possible contribution of apoA-II synthesized in these tissues to amyloid deposition.


Assuntos
Envelhecimento/fisiologia , Amiloidose/etiologia , Apolipoproteína A-II/isolamento & purificação , Animais , Apolipoproteína A-II/biossíntese , Apolipoproteína A-II/genética , Mucosa Gástrica/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Mucosa Intestinal/metabolismo , Intestinos/química , Fígado/química , Fígado/metabolismo , Camundongos , RNA Mensageiro/isolamento & purificação , Pele/química , Pele/metabolismo , Estômago/química , Língua/química , Língua/metabolismo
4.
Pathol Int ; 50(10): 793-800, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11107051

RESUMO

To clarify the clinicopathological features of an atypical cystic duct (ACD) as defined by Tsuchiya's criteria as a precancerous lesion of the breast, we used 200 whole mammary gland serial sections of breast cancer. Forty-four (22%) of the 200 breast cancer patients had ACD breast lesions. The frequency of patients with ACD increased in premenopausal women (P = 0.001). There was no correlation between the ACD-present group and the ACD-absent group for immunohistochemical status of the estrogen receptor (ER), progesterone receptor (PgR), p53, or c-erbB2; Ki-67 labeling index of cancer tissues; size of tumor, or lymph node metastases. A number of ACD lesions displayed continuity to cancer lesions. In 500 serial sections of a paraffin-embedded tissue of a ACD case at 3 microm intervals, an apparent transition from ACD into ductal carcinoma in situ was observed. Immunohistochemical analysis using alpha-smooth muscle actin showed that myoepithelial cells of ACD stained strongly, and their nuclei and cytoplasm were thinning. In 16 of the 44 (36%) ACD-present patients, carcinoma cells stained positive for p53. Within those 16 cases, 12 cases (75%) were positive for p53 in ACD lesions. There was a significant correlation between the expression of p53 protein in malignant cells and ACD (P = 0.001). All 44 ACD lesions had no staining of c-erbB2, regardless of staining in malignant lesions. The mean Ki-67 labeling index of ACD lesions was low (0.3%), suggesting that ACD had a low proliferative rate. We suggest that ACD is the precancerous breast lesion because of a histologic continuum between ACD and malignancy, and because of p53 protein expression in ACD.


Assuntos
Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Lesões Pré-Cancerosas/patologia , Adulto , Idoso , Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Neoplasias da Mama/cirurgia , Carcinoma in Situ/química , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/química , Carcinoma Ductal de Mama/cirurgia , Feminino , Humanos , Técnicas Imunoenzimáticas , Linfonodos/patologia , Metástase Linfática/patologia , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Lesões Pré-Cancerosas/química , Lesões Pré-Cancerosas/cirurgia , Pré-Menopausa , Receptores de Estrogênio/análise , Receptores de Progesterona/análise
5.
Cancer Cytopathol ; 87(5): 245-53, 1999 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-10536348

RESUMO

BACKGROUND: We previously reported that adenoma malignum (the mucinous type of minimal deviation adenocarcinoma [mucinous MDA]) of the uterine cervix expresses gastric phenotypes. The application of immunocytochemistry using HIK1083, a monoclonal antibody for gastric gland mucous cell mucin, enabled us to identify cellular clusters derived not only from typical lesions of mucinous MDA and less well differentiated lesions but also from gastric metaplasia. In this study, we tried to clarify the cellular features of such clusters in cervical and endometrial smears. METHODS: Twelve cases of mucinous MDA were studied. Papanicolaou stain and immunostaining with HIK1083 were performed on histologic and cytologic slides, including cervical and endometrial smears, decolorized smear slides, imprint slides of the tumors, and imprint slides of normal endocervical and gastric mucosa. RESULTS: Cellular clusters derived from metaplastic lesions, typical lesions, and less well differentiated lesions were found in 9, 4, and 2 cases, respectively. The cellular clusters derived from the metaplastic lesions lacked atypia but resembled those from gastric mucosa. Those derived from the typical lesions showed slight atypia. The cytoplasmic mucins of these cellular clusters, which were positive for HIK1083, were stained yellowish-orange by Papanicolaou stain, whereas those of normal endocervical cells were negative for HIK1083 and were stained pinkish by Papanicolaou stain. CONCLUSIONS: Yellowish-orange staining of cytoplasmic mucins by the Papanicolaou method is an important diagnostic clue aiding identification of mucinous MDA and related lesions by cytology. Moreover, immunostaining with HIK1083 is a useful tool in the diagnosis of these lesions by cytology as well as by histology. Cancer (Cancer Cytopathol)


Assuntos
Adenocarcinoma Mucinoso/patologia , Neoplasias do Colo do Útero/patologia , Adenocarcinoma Mucinoso/metabolismo , Adulto , Idoso , Citodiagnóstico , Feminino , Histocitoquímica , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Teste de Papanicolaou , Neoplasias do Colo do Útero/metabolismo , Esfregaço Vaginal
6.
Appl Opt ; 38(34): 7080-4, 1999 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18324254

RESUMO

A simple method of measuring the scattering losses of optical fibers was developed. The method permits the measurement of the scattering-loss spectra by use of photon counting. Measurement is based on right-angle scattering, which is dominated by Rayleigh scattering, a material-intrinsic loss. A reference fiber for which the scattering loss is known is used to cancel out the unknown factors that are dependent on the optical setup. The scattering-loss measurement was demonstrated by use of two different low-loss fibers and was found to agree with predetermined figures to within 10% over the wavelength range 0.44-1.0 microm. Finally, the method was applied to a new high-numerical-aperture optical fiber to find its material scattering loss.

7.
Pathol Int ; 48(5): 348-54, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9704341

RESUMO

Intending to clarify the true incidence of invasive lobular carcinoma of the breast in Japanese women as well as the frequency of unilateral multicentricity, 362 cases of clinically defined monocentric breast cancer without pre-operative biopsy (previously fine needle aspiration or needle biopsy were routinely carried out for every case) were examined by whole mammary gland serial sectioning. On the basis of pathology and the World Health Organization classification of breast tumors, each case was assigned to one of two main histologic types: invasive lobular carcinoma (ILC) or invasive ductal carcinoma (IDC). Invasive lobular carcinoma was further separated into classic and variant types by employing previously published criteria. Twenty-one cases of ILC (5.8%) were diagnosed, which is more than in most previous Japanese studies. Unilateral multicentric breast carcinoma was detected in 9.5% of ILC and 16.1% of IDC (the difference was found not significant). Microscopically, ILC tumors were found to be, on average, larger than IDC. Patients with classic type ILC tended to be younger than those with variant type or IDC. Estrogen receptor expression was found more frequently in variant type ILC than in classic type. These results suggest that the incidence of invasive lobular carcinoma of the breast in Japanese women is low and that unilateral multicentricity is not significantly higher in ILC than in IDC.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Lobular/patologia , Adulto , Idoso , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/metabolismo , Carcinoma Lobular/epidemiologia , Carcinoma Lobular/metabolismo , Feminino , Humanos , Japão , Microtomia , Pessoa de Meia-Idade , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo
8.
Dermatology ; 197(1): 58-61, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9693189

RESUMO

A 42-year-old man showed prominent blistering lesions of the mouth and esophagus in addition to a few bullous lesions of the skin. Direct immunofluorescence microscopy revealed distinct linear deposition of IgG and C3 at the epidermal basement membrane zone where slight deposition of IgA and IgM was also observed. In direct immunoelectron-microscopic examination, antibody was detected in the sublamina densa of the basement membrane zone. Immunoblot analysis with dermal extracts demonstrated that the patient's serum contained circulating IgG antibodies against the 290-kD protein, which comigrated with type VII collagen. The lesions healed without any scars. The results of these studies corresponded to the laboratory findings in epidermolysis bullosa acquisita (EBA), although the clinical features were distinct from classic EBA.


Assuntos
Colágeno/imunologia , Epidermólise Bolhosa Adquirida/diagnóstico , Epidermólise Bolhosa Adquirida/imunologia , Imunoglobulina G/sangue , Adulto , Anticorpos/sangue , Vesícula/etiologia , Doença Crônica , Diagnóstico Diferencial , Epidermólise Bolhosa Adquirida/complicações , Epidermólise Bolhosa Adquirida/patologia , Esofagoscopia , Humanos , Masculino , Microscopia de Fluorescência , Mucosa/patologia
9.
Int J Cancer ; 79(2): 179-86, 1998 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-9583734

RESUMO

To evaluate the association among known angiogenic growth factors or factors related to the plasminogen activation system and clinicopathological factors in patients with colorectal cancer, we examined the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PA-R) and plasminogen activator inhibitor-1 (PAI-1) in clinical specimens of colorectal cancers by Northern blot analysis. In comparison with the expression of these angiogenesis-related genes in 7 paired samples of colorectal cancers and the adjacent normal mucosa, VEGF mRNA level was significantly higher in the cancer tissues than in the adjacent normal mucosa (p < 0.05). We analyzed expression of these genes in 44 cases of primary colorectal cancers. Among the 3 angiogenic growth factors we examined, VEGF mRNA expression was significantly higher in the cancer tissues with blood vessel invasion or with lymphatic vessel invasion than in those without, respectively (p < 0.05). On the other hand, u-PA-R mRNA expression was significantly higher in the cancers with blood vessel invasion than in those without (p < 0.05). In addition, there was a correlation between the expression levels of VEGF and u-PA-R mRNA in the cancer tissues we have examined. Using immunohistochemistry, strong staining of VEGF or u-PA-R was observed in the cancer cells invading the microvessels. Our findings suggest that malignant transformation might accompany the upregulation of VEGF expression in colorectal cancers and that VEGF and u-PA-R might contribute cooperatively to increase angiogenesis around the tumor as well as the metastasis via microvessels.


Assuntos
Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/patologia , Fatores de Crescimento Endotelial/biossíntese , Linfocinas/biossíntese , Transcrição Gênica , Ativador de Plasminogênio Tipo Uroquinase/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular , Colo , Neoplasias do Colo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/cirurgia , Sondas de DNA , Fatores de Crescimento Endotelial/fisiologia , Feminino , Fator 2 de Crescimento de Fibroblastos/biossíntese , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Linfocinas/fisiologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , RNA Mensageiro/biossíntese , Fator de Crescimento Transformador alfa/biossíntese , Ativador de Plasminogênio Tipo Uroquinase/fisiologia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
10.
Breast Cancer ; 5(4): 411-416, 1998 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-11091684

RESUMO

An unusual case of synchronous bilateral breast cancer occurring during combination chemotherapy and radiation to the outside of the breast for malignant lymphoma is reported. Two histologically rare carcinomas, spindle cell carcinoma and apocrine carcinoma, were observed in this case. A 77-year-old woman, who had been treated for stage IIIA non-Hodgkin's lymphoma, developed bilateral breast tumors. Aspiration biopsy cytology findings of the tumor in the left breast showed several clusters of adenocarcinoma cells and some large atypical spindle shaped cells, which suggested spindle cell carcinoma. The cytologic findings of the right breast tumor were highly suggestive of scirrhous carcinoma. A modified radical mastectomy was performed on both breasts. Pathological examination disclosed two separate cancer lesions in the left breast. The lesion which had been detected before the operation, was a spindle cell carcinoma. Another lesion, detected for the first time by pathological examination, was an apocrine carcinoma. The lesion in the right breast was a scirrhous carcinoma. Since non-invasive fociwere detected in these three cancer lesions, each lesion was thought to be a primary cancer. All dissected bilateral axillary lymph nodes showed malignant lymphoma. Immuno-histochemistry of the spindle cell carcinoma revealed positive immunoreactivity for cytokeratin, which suggested the epithelial as well as mesenchymal nature of this tumor. Synchronous existence of malignant lymphoma and three independent breast cancers including spindle cell carcinoma and apocrine carcinoma is very rare.

11.
Breast Cancer ; 5(4): 411-6, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-18843558

RESUMO

An unusual case of synchronous bilateral breast cancer occurring during combination chemotherapy and radiation to the outside of the breast for malignant lymphoma is reported. Two histologically rare carcinomas, spindle cell carcinoma and apocrine carcinoma, were observed in this case. A 77-year-old woman, who had been treated for stage IIIA non-Hodgkin's lymphoma, developed bilateral breast tumors. Aspiration biopsy cytology findings of the tumor in the left breast showed several clusters of adenocarcinoma cells and some large atypical spindle shaped cells, which suggested spindle cell carcinoma. The cytologic findings of the right breast tumor were highly suggestive of scirrhous carcinoma. A modified radical mastectomy was performed on both breasts. Pathological examination disclosed two separate cancer lesions in the left breast. The lesion which had been detected before the operation, was a spindle cell carcinoma. Another lesion, detected for the first time by pathological examination, was an apocrine carcinoma. The lesion in the right breast was a scirrhous carcinoma. Since non-invasive foci were detected in these three cancer lesions, each lesion was thought to be a primary cancer. All dissected bilateral axillary lymph nodes showed malignant lymphoma. Immuno-histochemistry of the spindle cell carcinoma revealed positive immunoreactivity for cytokeratin, which suggested the epithelial as well as mesenchymal nature of this tumor. Synchronous existence of malignant lymphoma and three independent breast cancers including spindle cell carcinoma and apocrine carcinoma is very rare.

12.
Breast Cancer ; 4(3): 187-191, 1997 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-11091596

RESUMO

We encountered a very rarc case of occult breast cancer associated with paraneoplastic sensory polyneuropathy. A 59-year-old woman was admitted to our hospital complaining of numbness in all extremities, ataxia of left extremities and a tumor in the left axilla. From the neurological findings, a malignant tumor was suspected. The immunohistochemical analysis of the axillar swollen lymph node revealed metastasis from breast cancer and confirmed the primary lesion. On a preoperative diagnosis of suspected occult breast cancer, left mastectomy and resection of left axillar lymph nodes were performed. Furthermore, immunohistochemical staining of sural nerves and Western blot analysis of the serum of this patient showed the loss of axons and the presence of antineural antibody in the seurm. Immunological response was considered to be the remote effector system between the breast cancer and sensory polyneuropathy in this disorder.

13.
World J Surg ; 18(6): 921-4; discussion 925, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7846920

RESUMO

Primary hyperparathyroidism was investigated using the presence of basic fibroblast growth factor (bFGF) from the immunohistochemical viewpoint with an anti-bFGF antibody in hyperplastic parathyroid glands of patients with multiple endocrine neoplasia type I (MEN-I) and of patients with non-MEN. The results corresponded well with the data from the DNA analysis. Twenty-five hyperplastic parathyroid glands from 11 patients with MEN-I and 38 glands from 20 patients with non-MEN primary hyperparathyroidism were stained immunohistochemically according to the avidin-biotin-peroxidase complex procedure. When 50% or more of the cells appeared uniformly stained, it was judged positively stained. In addition, 18 hyperplastic parathyroid glands from patients with MEN-I patients and 24 hyperplastic parathyroid glands from non-MEN patients were also analyzed for DNA using flow cytometry. The ratio of positively stained hyperplastic parathyroid glands was 72% in MEN-I patients and 18% in non-MEN patients. The difference between the two groups was significant (p < 0.01). The nodules consisted of oxyphilic cells in 7 of 25 hyperplastic parathyroid glands from MEN-I patients and in 10 of 38 hyperplastic parathyroid glands from non-MEN patients, and all the cells were positive for bFGF. There was no significant correlation between bFGF staining and the DNA ploidy pattern. bFGF possibly plays a role in the development of parathyroid gland hyperplasia, especially in MEN-I patients. The increase of oxyphilic cells may be correlated with the expression of bFGF.


Assuntos
Fator 2 de Crescimento de Fibroblastos/análise , Neoplasia Endócrina Múltipla Tipo 1/metabolismo , Glândulas Paratireoides/química , Glândulas Paratireoides/patologia , Humanos , Hiperparatireoidismo/metabolismo , Hiperplasia , Imuno-Histoquímica , Neoplasia Endócrina Múltipla Tipo 1/patologia
15.
Gan No Rinsho ; 29(14): 1668-72, 1983 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-6607368

RESUMO

An autopsy case of adult T cell leukemia associated with hypercalcemia and hyperplastic parathyroid glands is reported. A 51-year-old man complained of systemic lymphadenopathy and hepato-splenomegaly; a diagnosis of adult T cell leukemia was made based on clinico-pathological findings. The pathogenesis of hypercalcemia in adult T cell leukemia is discussed. However, cases associated with hyperplasia of the parathyroid gland are very rare. We emphasize the role of the parathyroid gland in the pathogenesis of hypercalcemia in adult T cell leukemia.


Assuntos
Leucemia/patologia , Glândulas Paratireoides/patologia , Divisão Celular , Humanos , Hipercalcemia/complicações , Hipertrofia , Leucemia/complicações , Masculino , Pessoa de Meia-Idade , Linfócitos T
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...