Biomedical subjects

K Miyakawa

Publications and source records attributed to K Miyakawa.

At least 37 records · Page 2Linked to original sources

PubMed1998

Diagnostic value of contrast-enhanced computed tomography for diagnosing the intraductal component of breast cancer.

BACKGROUND: It is important to reduce local residual cancer to avoid local recurrence after breast conserving treatment. We therefore tried to detect the intraductal components and small invasive foci of breast cancers by contrast-enhanced helical computed tomography (CE-CT). METHODS: In 122 women whose breasts were examined by CE-CT preoperatively, intraductal spread detected on ultrasound (US), mammography (MMG), and CE-CT, and extensive intraductal components (EICs) detected by histological examination were analyzed for correlations among the extent and subtypes of intraductal components, and deviations in tumor size. RESULTS: EICs were present in 44 patients. The sensitivities of EIC detection by US, MMG, and CE-CT were 35%, 61%, and 88%, respectively, and the corresponding specificities were 83%, 86%, and 79%, respectively. The sensitivities of detecting EIC and small invasive foci were 34%, 57%, and 91%, respectively. In 5 patients, EIC could only be visualized by CE-CT. The median deviation of the size of intraductal spread revealed by CE-CT from pathological EIC was 0.0 cm (range + 3.0 to - 1.7 cm). CONCLUSIONS: CE-CT is useful for visualizing intraductal spread and small invasive foci of breast cancer.

Adult↗

PubMed1998

Properties of the membranes containing the particulate methane monooxygenase from Methylosinus trichosporium OB3b.

The particulate methane monooxygenase (pMMO) from Methylosinus trichosporium OB3b was partially purified and characterized by measuring the effects of reducing agents and additives, and the stability of pMMO was studied. Duroquinol was a suitable reducing agent, and pMMO was stabilized by bovine serum albumin (BSA). Among the additives, the copper (II) ion stimulated pMMO at low concentration and inhibited at high concentration. The optimum conditions for pMMO activity were as follows: 45 degrees C, pH 6.5 and 55 mM 3-morpholinopropanesulfonic acid (MOPS) buffer, and the rate of propene epoxide formation was 13.6 nmol min-1 mg-1 protein. ESR spectra indicate that the copper cluster in the membrane fraction is reduced by duroquinol and oxidized by dioxygen. The result suggests that the copper cluster is contained in the active site of pMMO.

Animals↗

PubMed1998

Systemic and local immunological features of atopic dermatitis patients with ocular complications.

AIMS: Clinical factors and data from recent cases of atopic dermatitis (AD) (with or without ocular complications) and non-AD cases were examined to evaluate the mechanism of atopic ocular complications. METHODS: IgE-RAST for eight allergens including rice, egg, and mite and serum total IgE were measured in 216 patients with AD (70 ocular type, 146 non-ocular type) and 69 non-AD individuals. Tear histamine and leukotriene B4 (LTB4) levels were also measured. RESULTS: The serum levels of IgE were significantly increased in AD patients with ocular complications compared with those without ocular complications. The positive rates of IgE-RAST for rice and wheat were significantly higher in ocular type AD than in non-ocular type AD. In ocular type AD, serum IgE was significantly increased in patients with cataract compared with that in those without cataract. Tear histamine and LTB4 levels in AD patients with ocular complications showed significant elevations compared with those in patients with pure AD and controls. CONCLUSIONS: These results suggest that ocular type AD belongs to the most severe end of the spectrum of AD, and that some food antigens may contribute to the pathogenesis of severe AD resulting in ocular complications.

Adolescent↗

PubMed1998

Effects of granulocyte/macrophage colony-stimulating factor on the development and differentiation of CD5-positive macrophages and their potential derivation from a CD5-positive B-cell lineage in mice.

In co-cultures of either the murine pre-B cell line J13, fetal liver cells, or adult peritoneal or bone marrow cells with ST2 mouse bone marrow stromal cells in the presence of granulocyte/macrophage colony-stimulating factor (GM-CSF), the development of CD5+ macrophages was demonstrated by immunohistochemical staining and flow cytometry. Although CD5+ macrophages were not present in the peritoneal cavities of normal mice, approximately 30% of the peritoneal macrophages in viable motheaten (mev/mev) mice, deficient in SHP-1 protein tyrosine phosphatase, expressed cell surface CD5 and B220, markers for B cells. In the mev/mev mice, GM-CSF level in peritoneal fluid was increased significantly. At 5 days after daily intravenous injection with GM-CSF, many CD5+ macrophages appeared in the peritoneal cavity and in omental milky spots of normal mice but fewer in osteopetrosis (op) mutant mice, deficient in macrophage (M)-CSF. These results indicate that GM-CSF, in combination with M-CSF, induces the development and differentiation of CD5+ macrophages in the peritoneal cavity, particularly in the omental milky spots of mice. In the peritoneal cavity of GM-CSF-treated mice, the percentages of hematopoietic progenitor cells doubly positive for CD5 and CD34 or c-kit and of macrophage precursor cells doubly positive for CD5 and ER-MP58 or ER-MP20 were increased significantly during the development of CD5+ macrophages and CD5 B cells, suggesting that CD5+ macrophages and B cells may share a bipotential progenitor in vivo.

Animals↗

PubMed1998

[Estimation of cell proliferation in hepatocellular carcinoma and in background liver cirrhosis, by using MIB-1 LI].

The 23 hepatectomized patients with hepatocellular carcinoma (HCC) were studied. Samples were biopsied from both cancerous portion and from non-cancerous cirrhotic portion at operation. MIB-1 LIs were measured in these biopsied samples. Then the relationships between MIB-1 LIs and pathologic feature, clinical data, and prognosis were investigated. LIs of the cancerous portion (10.2 +/- 6.8%, Mean +/- SE) were significantly (p < 0.001) greater than those of non-cancerous cirrhotic portion (3.8 +/- 2.1%). LIs of the cancerous portion in the patients who were dead with in 18 months after their hepatectomies, were significantly (p < 0.05) greater than those in the patients who survived more than 18 months after operations. LIs of the cancerous portion in the patients whose samples revealed Edmondson & Steiners classification grade III, were significantly (p < 0.05) greater than those in the patients whose samples revealed grade II. LIs of the cancerous portion in the patients whose serum AFP levels showed high level (> or = 100 ng/ml) were significantly (p < 0.005) greater than those in the patients whose serum AFP levels showed low level (< 100 ng/ml). And LIs of the non-cancerous portion in the patients whose thymol turbidity test (TTT) showed high level (> 5K-U), were significantly (p < 0.005) greater than those in the patients whose TTT levels showed within normal range. LIs of the non-cancerous potion in the patients whose zinc sulphate turbidity test (ZTT) showed high level (> 12K-U), were significantly (p < 0.01) greater than those in the patients whose ZTT levels showed within normal range. LIs of the non-cancerous portion in the patients whose PT levels were prolonged (14 sec <), were significantly (p < 0.05) greater than those in the patients whose PT levels were within range. MIB-1 LIs were proved to be a good marker for estimation of biological behaviour of HCC tumors.

Aged↗

PubMed1997

Clinical Use of Contrast-Enhanced Computed Tomography for Decision Making in Breast Conserving Surgery.

BACKGROUND: A reduction in local residual breast cancer is important to avoid local recurrence after breast conserving treatment (BCT). Previous studies suggested the usefulness of contrast-enhanced computed tomography (CE-CT) in detecting extensive intraductal component(EIC), which is associated with local recurrence. This study investigates the practical role of CE-CT in BCT. METHODS: In 130 women whose breasts were examined by CE-CT preoperatively, intraductal spread detected using ultrasound (US), mammography (MMG) and CE-CT, and EIC detected by histological examination were analyzed to determine possible correlations among the extent and subtypes of intraductal components. RESULTS: The sensitivities of EIC detection by US, MMG and CE-CT were 29%, 53% and 88%, respectively, and the corresponding specificities were 58%, 70% and 72%, respectively. In 6 patients, EIC could only be visualized using CE-CT. CE-CT demonstrated the extent of cancerous lesions more accurately than standard diagnostic modalities. Intraductal components with a higher histological grade tended to show stronger enhancement. Most false negative intraductal components obtained on CE-CT (6/7) were of a low histological grade. CONCLUSIONS: CE-CT is useful for visualizing EIC and small invasive foci of breast cancer, and can suggest the optimal extent of resection.

Journal Article↗

PubMed1997

Diagnostic Value of Enhanced Computed Tomography in the Detection of the Widely Spreading Intraductal Component of Breast Cancer: Case Reports.

We report cases of breast cancer with extensive intraductal component (EIC), the extent of which could be detected only by contrast-enhanced computed tomography (CT) scan. One case was a 32-year-old woman who presented left nipple bloody discharge without breast mass palpation. Mammography (MMG), galactography and ultrasonography (US) showed no abnormalities. Contrast helical CT scan revealed numerous patchy enhancement in the upper-outer quadrant of the left breast. Histological examnation revealed invasive ductal carcinoma with a predominant intraductal component. The second case was a 36- year-old woman who had noticed a left breast mass 2.4 cm in diameter. MMG and US suggested a localized breast cancer. Contrast helical CT scan revealed numerous patchy enhancement throughout the mammary gland in addition to the index tumor near the nipple. Histopathological results indicated invasive ductal carcinoma with widely spread ELC. In these two cases, the extent of intraductal cancer also correlated well with the CT findings. Breast CT scan can be an effective tool for determining the extent of the intraductal component of breast cancer, which is an important factor when considering breast-conserving therapy.

Journal Article↗

PubMed1997

Effects of in situ freezing and stress-shielding on the ultrastructure of rabbit patellar tendons.

The effects of in situ freezing and the combination of in situ freezing and stress-shielding on the microstructure and ultrastructure of the patellar tendon were studied with use of 20 mature rabbits. The patellar tendon was frozen in situ with liquid nitrogen to kill fibroblasts and then was completely released from stress by chronically pulling a stainless-steel wire installed between the patella and the tibial tubercle. Microstructurally, the freezing treatment induced separation of collagen fiber bundles and fibroblast necrosis at 3 weeks, although the separation disappeared at 6 weeks. Ultrastructurally, small collagen fibrils with a diameter of less than 90 nm were predominant; at 6 weeks, the area occupied by collagen fibrils had decreased. In the frozen-shielded tendon, numerous large spaces were observed in the matrix at 3 weeks. This treatment increased the number of fibrils with a diameter greater than 360 nm and decreased the number of collagen fibrils per unit of area and the area occupied by collagen fibrils at 3 weeks. This study demonstrated that in situ freezing and the combination of in situ freezing and stress-shielding leads to a smaller volume of collagen fibrils per unit of cross section of the patellar tendon by mechanisms that remain to be defined.

Animals↗

PubMed1997

Abdominal actinomycosis: barium enema and computed tomography findings.

A case of abdominal actinomycosis is described in a woman with recurrent right lower abdominal pain and low-grade fever without history of appendectomy. Past history included the use of an intrauterine device (IUD) until 10 years before manifestation of these symptoms. We followed up the patient, via diagnostic imaging, for 7 months. On initial barium enema, a polypoid lesion was visualized at the bottom of the cecum and there was constriction of the sigmoid colon; the appendix was not seen. Seven months later, poor extension at the cecum, severe constriction in the sigmoid colon, and narrowing of the terminal ileum were also visualized. On computed tomography (CT), the lesion was initially localized only in the ileocecal region adjacent to the sigmoid colon. After 7 months, the lesion had infiltrated adjacent anatomic components and showed direct infiltration of the pelvic space. Differential diagnosis was difficult, as it was not obvious whether this was a pelvic abscess due to inflammation or appendiceal carcinoma. Laparotomy was performed. Macroscopically, the lesion was not limited to the ileocecal region, but involved the right ureter, tubes the Fallopian and ovary, bladder, psoas muscle, and abdominal wall. Pathology findings showed, chronic inflammatory tissue with evidence of actinomycosis. Although previous reports have described a lack of specific findings in this disease. When actinomycosis is suspected, CT is recommended to define its extent.

Abdominal Abscess↗

PubMed1997

A case of bilateral reversible thalamic lesions.

We describe a case of bilateral reversible thalamic lesions with no neurological deficits and a good prognosis. The lesions appeared as low-density areas on CT and high-intensity areas on T2-weighted MR imaging, and resolved within 1 month, suggesting that the cause was edema.

Female↗

PubMed1997

Lymphohaematopoietic abnormalities and systemic lymphoproliferative disorder in interleukin-2 receptor gamma chain-deficient mice.

Interleukin-2 (IL-2) receptor gamma chain-deficient mice with a truncated mutation showed the absence or severe reduction of natural killer cells, decreased numbers of T- and B-cells, marked hypoplasia of the thymus and peripheral lymphoid tissues, defective formation of lymphoid follicles and germinal centre in the peripheral lymphoid tissues, and the absence of Peyer's patches in the intestinal mucosa. In addition, marked splenomegaly with extramedullary haematopoiesis, increased level of IgM and decreased levels of IgG and IgE in serum, severe reduction of conventional B cells (B-2) in the peripheral lymphoid tissues, the presence of IgM-producing CD5+ B cells (B-1) and their differentiation into plasma cells and Motto cells in the spleen, and increased production and differentiation of macrophages in various tissues were found in the mutant mice. However, the development of both marginal metallophilic macrophage populations in the spleen and of their related macrophages in the other tissues of the mutant mice was severely impaired. All these abnormalities seem to be induced by the loss-of-function of the IL-2 receptor gamma chain. From 8 weeks of age on, inflammatory changes occurred in the intestines, mesenteric lymph nodes, lungs, liver, and kidneys of the mutant mice. Besides the absence of Hassall's corpuscles, thymic cysts were frequently observed in the mutant mice. These pathological abnormalities suggest that the gamma chain is implicated not only in lymphoid and haematopoietic development but also in thymic epithelial cell ontogeny.

Animals↗

PubMed1997

Abnormal development and differentiation of macrophages and dendritic cells in viable motheaten mutant mice deficient in haematopoietic cell phosphatase.

In mice homozygous for the 'viable motheaten' (mev) mutation, numbers of macrophage progenitor cells, particularly monocytes, were markedly increased in the bone marrow and spleen. Increased mobilization of these precursor cells to peripheral tissues and their differentiation to macrophages were evidenced by striking increases in macrophage numbers. Immunohistochemical double staining of tissue sections and flow cytometry analyses of single cell suspensions from these mice demonstrated CD5 (Ly-1)-positive macrophages in the peritoneal cavity, spleen and other tissues. Ly-1-positive macrophage precursor cells were demonstrated in the peritoneal cavity of the mev mice and developed in the omental milky spots. The development of marginal metallophilic and marginal zone macrophages was poor in the splenic white pulp and related macrophage populations were absent in the other lymphoid tissues. The numbers of epidermal Langerhans cells in the skin and T cell-associated dendritic cells in the thymic medulla, lymph nodes, and the other peripheral lymphoid tissues were decreased. However, increased numbers of dendritic cells accumulated in the lungs, liver, and kidneys. These abnormalities in development and differentiation of macrophages and dendritic cells may be ascribed to the deficiency in haematopoietic cell SHP-1 tyrosine phosphatase or may be a secondary consequence of abnormal microenvironments, (either constitutive or in response to inflammatory stimuli) in the haematopoietic and lymphopoietic organs and tissues of these mice.

Animals↗

PubMed1997

Hepatic tumor invasion of bile ducts: wedge-shaped sign on MR images.

PURPOSE: To clarify the diagnostic importance of wedge-shaped areas of increased signal intensity that surround liver tumors on T1-weighted magnetic resonance (MR) images. MATERIALS AND METHODS: In five patients with hepatic tumors, T1-weighted MR images that demonstrated wedge-shaped areas of increased signal intensity in the liver were reviewed; findings were compared with those at surgical and histologic examinations. RESULTS: MR images showed localized intrahepatic bile duct dilatation lateral (three patients) and medial (two patients) to liver tumors within the wedge-shaped areas. At histopathologic examination, intraductal tumor growth was seen in local bile ducts in the same areas in five patients, and lipofuscin deposits were seen in the cytoplasm of atrophic hepatocytes in three patients. CONCLUSION: On T1-weighted images, wedge-shaped areas of increased signal intensity associated with liver tumors indicate intraductal tumor extension in intrahepatic bile ducts. T1 shortening is possibly caused by lipofuscin deposits in atrophic hepatocytes.

Adult↗

PubMed1997

Analysis of amyloid deposition in a transgenic mouse model of homozygous familial amyloidotic polyneuropathy.

Amyloid fibrils derived from the Japanese, Portuguese, and Swedish types of familial amyloidotic polyneuropathy all consist of a variant transthyretin (TTR) with a substitution of methionine for valine at position 30 (TTR Met 30). In an attempt to establish an animal model of TTR Met-30-associated homozygous familial amyloidotic polyneuropathy and to study the structural and functional properties of human TTR Met 30, we generated a mouse line carrying a null mutation at the endogenous ttr locus (ttr-/-) and the human mutant ttr gene (6.0-hMet 30) as a transgene. In these mice, human TTR Met-30-derived amyloid deposits were first observed in the esophagus and stomach when the mice were 11 months of age. With advancing age, amyloid deposits extended to various other tissues. Because no significant difference was detected in the onset, progression, and tissue distribution of amyloid deposition between the ttr-/- and ttr+/+ transgenic mice expressing 6.0-hMet 30, endogenous normal mouse TTR probably does not affect the deposition of human TTR Met-30-derived amyloid in mice. TTR is a tetramer composed of four identical subunits that binds thyroxine (T4) and plasma retinol-binding protein. The introduction of 6.0-hMet 30 into the ttr-/- mice significantly increased their depressed serum levels of T4 and retinol-binding protein, suggesting that human TTR Met 30 binds T4 and retinol-binding protein in vivo. The T4-binding ability of human TTR Met 30 was confirmed by the analysis of T4-binding proteins in the sera of ttr-/- transgenic mice expressing 6.0-hMet 30. The T4-binding studies also demonstrated the presence of hybrid tetramers between mouse and human TTR subunits in the ttr+/+ transgenic mice expressing 6.0-hMet 30.

Amyloid↗

PubMed1996

Expression of the fibroblast growth factor family and their receptor family genes during mouse brain development.

The fibroblast growth factor (FGF) family is composed of nine members and four genes encode protein tyrosine kinase receptors for them. To gain insight into the involvement of FGFs and their receptors in the development of nervous system, their expression in brains of perinatal and adult mice was examined by semi-quantitative reverse transcription-linked polymerase chain reactions and in situ hybridization. Although all the genes, with the exception of FGF-4, were found to be expressed, FGF-3, FGF-6, FGF-7 and FGF-8 genes demonstrated higher expression in the late embryonic stages than in postnatal stages, suggesting that these members are involved in the late stages of brain development. In contrast, expression of FGF-1 and FGF-5 increased after birth. Interestingly, FGF-6 expression in perinatal mice was restricted to the central nervous system and skeltal muscles, with intense signals in the developing cerebrum in embryos but in cerebellum in 5-day-old neonates. Furthermore, FGF-receptor (FGFR)-4, a cognate receptor for FGF-6, demonstrated similar spatiotemporal expression, suggesting that FGF-6 and FGFR-4 plays significant roles in the maturation of nervous system as a ligand-receptor system. The results indicate that individual member of the fibroblast growth factor and their receptor family are expressed either sequentially or simultaneously in brain development, strongly suggesting their involvement in the regulation of a variety of developmental processes of brain, i.e., proliferation and migration of neuronal progenitor cells, neuron and glia differentiation, neurite extensions, and synapse formations.

Animals↗

PubMed1996

Modulation of hematopoiesis in mice with a truncated mutant of the interleukin-2 receptor gamma chain.

The interleukin-2 (IL-2) receptor gamma chain is indispensable for IL-2-, IL-4-, IL-7-, IL-9-, and IL-15-mediated signaling. Mutations of the human gamma chain cause the X-linked severe combined immunodeficiency (XSCID), showing that T and natural killer cells absolutely require the gamma chain for their development in humans. To elucidate the roles of the gamma chain in hematopoiesis, we have generated mice, by gene targeting, that express a form of the gamma chain lacking the cytoplasmic region. Male mice carrying the truncated gamma-chain mutant, which mimics mutations in patients with XSCID, showed a decrease in the number of lymphocytes and an increase in monocytes; the number of T cells was profoundly reduced and no natural killer cells were detected, which is similar to the characteristic of human XSCID. Unlike human XSCID, the levels of B cells were also reduced. In spite of the severe decrease in CD45R+/sIgM+ B cells, the level of IgM in serum of the 8-week-old mutant mice was higher than that of control littermates. Interestingly, the stem cell population with surface phenotypes of CD34, c-kit, and Sca-1 was significantly increased. Furthermore, the colony-forming assay showed that the mutant mice had 15-fold higher numbers of hematopoietic progenitor cells in the spleen as compared with that of controls. These results indicate that functional loss of the gamma chain causes significant effects on the immunological system in mice.

Animals↗

PubMed1996

Dermatofibrosarcoma protuberans. CT findings with pathologic correlation in 6 cases.

PURPOSE: To characterize the CT findings of dermatofibrosarcoma protuberans. MATERIAL AND METHODS: CT and pathologic specimens of 6 patients with dermatofibrosarcoma protuberans (5 in the trunk and 1 in the leg) were retrospectively reviewed. RESULTS: CT clearly defined the tumors in the dermis and subcutaneous tissue with a characteristic, if not pathognomonic, protrusion. On postcontrast CT, 3 tumors showed marginal enhancement and central low density, while the others showed homogeneous enhancement. Pathologically, the marginal enhancement on CT corresponded to fibrosarcomatous changes, and the central low density to necrosis. The tumors with homogeneous enhancement had no sarcomatous changes. CONCLUSION: CT allows detection and precise anatomic localization of dermatofibrosarcoma protuberans. Marginal enhancement with central low density on CT may suggest a relatively poor prognosis.

Adult↗

PubMed1996

[An examination of the Cúnzhēn Huán Zhōng Tú].

A human dissection autopsy was performed in China in 1045, resulting in the production of the Oū Xī-fang Wū Zàng Tú. Subsequently, between 1102 and 1106, Yang Jie augmented this with the Cūn Zhén Tú. Both of these have not been preserved. The author has re-examined these on the basis of materials (preserved in Japan) left by the 16th century figure Gen'un. 1. The material used by Gen'un was the Cun Zhēn Huánzhōng Tú, and he did not cite directly from the Oū Xī-fang Wū Zàng Tú. 2. The drawing of internal viscera cited by Gen'un is the same as that cited in the Ton'ishō. 3. Cún Zhēn Huánzhōng Tú is comprised of two sections; the drawings and explanations in the Cún zhēn Tú deal with internal viscera, and those of the Huánzhōng Tú with meridians and acupoints. 4. The explanatory text in the Cún Zhēn Tú cited by Gen'un accords with the citation in the extant text of the Xīnkè Huá Tuó Nèizhao Tú. 5. Kōzō Watanabe has argued that the Ton'ishō cited the Cún Zhēn Huánzhōng Tú in its entirety, but this is incorrect. Rather, the citation is only a partial one.

Anatomy↗