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M Ohara

Publications and source records attributed to M Ohara.

At least 19 recordsLinked to original sources
PubMed2006

Intracytoplasmic lumina in invasive micropapillary carcinoma of the lung.

Micropapillary carcinoma of the lung is a rare neoplasm, and several reports on micropapillary carcinoma of the lung have been presented to date. We present a case of micropapillary carcinoma of the lung here. A 75-yr-old Japanese man received the medical checkup and his chest X-ray disclosed the abnormal shadow of the lower lobe of the left lung. The histological examination of resected lung and extirpated lymph node showed the finding of micropapillary carcinoma. Some neoplastic cells of primary site contained intracytoplasmic lumina positive for Alcian blue and PAS stains. Pleural effusion appeared 9-mo after the operation. The cytology of pleural effusion showed cohesive clusters of neoplastic cells consisting of 3-20 cells without fibrovascular core. Additionally, intracytoplasmic lumina were observed in some neoplastic cells. Finally, carcinoma cells with micropapillary morphology may possess the intracytoplasmic lumina in the cytoplasm of metastatic site as well as primary site.

Aged↗
PubMed2006

Seasonal changes in pollinator activity influence pollen dispersal and seed production of the alpine shrub Rhododendron aureum (Ericaceae).

In alpine ecosystems, microscale variation in snowmelt timing often causes different flowering phenology of the same plant species and seasonal changes in pollinator activity. We compared the variations in insect visitation, pollen dispersal, mating patterns, and sexual reproduction of Rhododendron aureum early and late in the flowering season using five microsatellites. Insects visiting the flowers were rare early in the flowering season (mid-June), when major pollinators were bumblebee queens and flies. In contrast, frequent visitations by bumblebee workers were observed late in the season (late July). Two-generation analysis of pollen pool structure demonstrated that quality of pollen-mediated gene flow was more diverse late in the season in parallel with the high pollinator activity. The effective number of pollen donors per fruit (N(ep)) increased late in the season (N(ep) = 2.2-2.7 early, 3.4-4.4 late). However, both the outcrossing rate (t(m)) and seed-set ratio per fruit were smaller late in the season (t(m) = 0.89 and 0.71, seed-set ratio = 0.52 and 0.18, early and late in the season, respectively). In addition, biparental inbreeding occurred only late in the season. We conclude that R. aureum shows contrasting patterns of pollen movement and seed production between early and late season: in early season, seed production can be high but genetically less diverse and, during late season, be reduced, possibly due to higher inbreeding and inbreeding depression, but have greater genetic diversity. Thus, more pollinator activity does not always mean more pollen movement.

Animals↗
PubMed2006

Gastric carcinosarcoma with neuroendocrine differentiation as the carcinoma component and leiomyosarcomatous and myofibroblastic differentiation as the sarcomatous component.

Gastric carcinosarcoma with neuroendocrine differentiation is a very rare neoplasm. In this article we present such a case. The gastroendoscopic examination of a 59-year-old Japanese man disclosed gastric cancer during follow-up after operation for rectal cancer. Subsequently, total gastrectomy was carried out because of gastric cancer. A large tumor measuring 9.2 x 8.4 cm was observed in the posterior wall of the upper portion of the stomach. The tumor was composed of carcinoma and sarcomatous cells, and the histological transition of both components was observed. Immunohistochemically, carcinoma and sarcomatous cells were positive for cytokeratin CAM5.2. The carcinoma contained adenocarcinoma and malignant cells with neuroendocrine differentiation. The sarcomatous component showed leiomyosarcomatous and myofibroblastic differentiation. The present tumor is the fifth case of gastric carcinosarcoma with neuroendocrine differentiation and the first case of gastric carcinosarcoma with myofibroblastic differentiation. Pathologists should bear in mind that gastric carcinosarcoma may show various types of differentiation.

Carcinoma, Neuroendocrine↗
PubMed2006

Lung adenocarcinoma with a micropapillary pattern: a clinicopathological study of 25 cases.

Lung adenocarcinoma with a micropapillary pattern has recently been described, but its biological behavior is as yet uncertain. In this article we present a clinicopathological study of lung adenocarcinoma with micropapillary morphology. We selected 25 patients with lung adenocarcinoma with micropapillary morphology from the 2001-2004 pathology files (age range 54 to 81 years; mean 64.5 years). Micropapillary carcinoma is predominantly located at the periphery of the tumor nodule or mass and occurs irrespective of the subtype of the adenocarcinoma. A micropapillary component was seen against a mucinous background in three cases and microcalcifications resembling psammoma bodies were seen in one case. Four cases showed intensive invasive growth such as micropapillary adenocarcinoma of the breast and 21 showed alveolar type morphology with piling-up of the neoplastic cells with or without stromal invasion. Seven of twenty-three (30.4%) showed lymph node metastases at time of operation. Twelve of twenty-five (48%) showed pleural invasion. Regarding clinical outcome, 14 patients were alive without disease, 5 were alive with disease, and 5 died of the lung adenocarcinoma. No significant relationship was found between the extent of the micropapillary component and prognosis. However, the carcinoma seen in the five patients who died showed breast type histology with intensive invasive growth in three cases and alveolar type histology with intensive stromal invasion in two. Lung micropapillary carcinoma of breast type may behave more aggressively than the alveolar type.

Adenocarcinoma↗
PubMed2006

Female urethral adenocarcinoma with a heterogeneous phenotype.

We here report a very rare case of female urethral adenocarcinoma. A 77-year-old woman presented with urinary retention. Cystoscopy showed a urethral tumor and the biopsy material showed adenocarcinoma. Macroscopically, the tumor measuring 3.0 x 3.0 x 2.4 cm was predominantly observed around the periurethral area on the proximal side. Histologically, patterns of columnar/mucinous adenocarcinoma, clear cell adenocarcinoma and papillary/micropapillary carcinoma were observed, but there was no evidence of a cribriform pattern. Immunohistochemically, neoplastic cells of at least one of three components were positive for CK7 and CK20 or CA125. We suggest that female urethral adenocarcinoma with a histologically and immunohistochemically heterogeneous phenotype may originate from cells within urethral or paraurethral tissue, such as urethritis glandularis or intestinal metaplastic epithelium and Mullerian tissue.

Adenocarcinoma↗
PubMed2006

Bilateral hamartoma arising in axillary accessory mammary glands. Case report.

A 57-year-old Japanese woman presented with a lump, originally noticed 10 years previously, in both axillary regions. Histologically, the axillary tumors consisted of a random admixture of ducts, lobules and fibrous stroma with predominant adipose tissue. This is the first case of bilateral ectopic hamartoma arising in the axillary regions. Surgeons and pathologists should be aware that ectopic breast hamartoma can occur in both axillary regions.

Breast Neoplasms↗
PubMed2006

Bridging necrosis and reticulin bridging fibrosis induced by intrahepatic involvement of acute biphenotypic leukemia.

A 47-year-old Japanese woman was diagnosed as having acute biphenotypic leukemia with association of t(9;22)(q34;q11). Cholestatic liver dysfunction arose, and she died of cachexia and intracranial hemorrhage. Autopsy showed unusual hepatic fibrosis. In the liver, bridging infiltration, bridging necrosis and bridging fibrosis by leukemic cells were seen. It seemed that the degree of fibrosis was associated with the number of aggregates of infiltrating leukemic cells. The fibrotic foci were predominantly composed of reticulin and collagen fibers, and distortion of the lobules was observed. Immunohistochemically, dense bundles of alpha-smooth muscle actin (ASMA)-positive stromal cells, namely activated hepatic stellate cells (HSCs), were observed in the immature fibrotic foci as well as along the sinusoids densely infiltrated by leukemic cells. No cells positive for TGF-beta1 or PDGF-BB were identified. In conclusion, extensive intrahepatic involvement by neoplastic cells in adult acute biphenotypic leukemia may cause the unusual "disorganized" hepatic fibrosis.

Becaplermin↗
PubMed2004

Clinical and pathological differences between Mikulicz's disease and Sjögren's syndrome.

OBJECTIVE: Mikulicz's disease (MD) has been included within the diagnosis of primary Sjögren's syndrome (SS), but represents a unique condition involving enlargement of the lachrymal and salivary glands and characterized by few autoimmune reactions and good responsiveness to glucocorticoids. We have previously described elevated immunoglobulin (Ig) G4 in the serum of four patients with MD. In this paper, we accumulated more MD cases and undertook clinical and histopathological analysis of these patients to clarify differences between MD and SS. METHODS: We diagnosed seven patients with MD according to the following criteria: (i) visual confirmation of symmetrical and persistent swelling in more than two lachrymal and major salivary glands; (ii) prominent mononuclear infiltration of lachrymal and salivary glands; and (iii) exclusion of other diseases that present with glandular swelling, such as sarcoidosis and lymphoproliferative disease. We summarized the clinical and serological characteristics (IgG subclasses and IFN-gamma/IL-4 ratio) of seven patients with MD, compared with SS with glandular swelling (SSw) and without glandular swelling (SSo). After steroid administration, we analysed changes in IgG subclasses in MD. Labial salivary gland specimens in MD, SSw and SSo were stained with anti-IgG4 antibodies. RESULTS: The concentration (+/-s.d.) of IgG4 was 1169.7 +/- 892.2 mg/dl in MD, 24.4 +/- 7.0 mg/dl in SSw (P<0.005) and 82.6 +/- 189.7 mg/dl in SSo (P<0.005). The IFN-gamma/IL-4 ratio was 0.392 +/- 0.083 (0.78 +/- 0.23/2.14 +/- 0.31 IU/pg) in MD, 0.004 +/- 0.002 (0.20 +/- 0.07/57.02 +/- 14.05 IU/pg) in SSw (P<0.05) and 0.012 +/- 0.009 (0.58 +/- 0.86/116.24 +/- 207.65 IU/pg) in SSo (P<0.05). The concentration (+/-s.d.) of IgG4 in MD decreased to 254.0 +/- 50.3 mg/dl (P<0.05) after glucocorticoid treatment. Histopathologically, only MD was associated with prominent infiltration of IgG4-positive plasmacytes into lachrymal and salivary glands. CONCLUSION: Mikulicz's disease is quite different from SS clinically and histopathologically. MD is suggested to be an IgG4-related systemic disease.

Aged↗
PubMed2004

Elevated IgG4 concentrations in serum of patients with Mikulicz's disease.

Mikulicz's disease has recently been included within primary Sjögren's syndrome. It is a unique condition involving enlargement of the lacrimal and salivary glands, characterized by few autoimmune reactions. It is responsive to glucocorticoid treatment. Analysis of IgG fractions was performed in patients with Mikulicz's disease in order to determine the differences between Mikulicz's disease and Sjögren's syndrome. The study showed that serum IgG4 concentrations are elevated in patients with Mikulicz's disease, but not in those with Sjögren's syndrome.

Aged↗
PubMed2004

Blue light inhibits melanin synthesis in B16 melanoma 4A5 cells and skin pigmentation induced by ultraviolet B in guinea-pigs.

BACKGROUND: Little has been known about the effects of visible light in mammalian cells. We recently found that blue light not only suppressed the growth of B16 melanoma cells in a time-dependent manner but also inhibited metastasis of the B16 melanoma cells to the lung. These findings suggest that exposure to blue light modifies the functions of B16 melanoma cells. The present study investigated the effects of blue light on B16 melanoma 4A5 cells and Weiser-Maple guinea-pigs to confirm the biological effect of blue light on melanin formation. METHODS: The effect of red, green, and blue light on melanin synthesis in B16 melanoma 4A5 cells was measured. The back skin of brown Weiser-Maple guinea-pigs was exposed to ultraviolet B (UVB; 588 mJ/cm(2) (0.7 mW/cm(2)x 14 min) three times a week for 2 weeks to induce melanin deposition. Thirty minutes after each UVB exposure, blue light was applied for 30 min. Pigmentation of the exposed areas of skin was checked once a week, and photographs of the skin were taken by digital camera. Observation was continued for 18 days after the final UVB exposure. RESULTS: Melanin synthesis in B16 melanoma 4A5 cells was selectively suppressed by blue light, but blue light did not induce decolorization of previously produced melanin. In the back skin of brown guinea-pigs, the brightness of the sites exposed to UVB began to decrease on the fifth day of the experiment, decreasing further from the 12th day to the 18th day after UVB exposure. The brightness of the sites exposed to UVB and blue light decreased in a manner similar during the UVB exposure, but remained relatively unchanged from the 12th day to the 30th day. CONCLUSIONS: These results suggest that blue light suppresses melanin formation following repeated UVB exposure. Further investigation with various light such as blue light may lead to a new approach to the care of ultraviolet-affected skin such as hyperpigmentation.

Animals↗
PubMed2001

Jejunal carcinoid tumor mimicking leiomyosarcoma: preoperative diagnosis by endoscopic biopsy.

Primary carcinoid tumor of the jejunum is rare, and is an unusual cause of massive gastrointestinal bleeding. A case of primary jejunal carcinoid tumor in a 39-year-old woman who presented with massive hematochezia is described. Both upper and lower gastrointestinal endoscopies showed no abnormalities. An abdominal computed tomographic scan, small-bowel barium contrast studies, and small-bowel endoscopy showed a subserosal mass, of 5 x 4 cm, with a cavity suggesting central necrosis, and a deep mucosal ulceration, located in the proximal jejunum. Although these clinical presentations were strongly suggestive of a leiomyosarcoma, histologic examination of biopsy samples obtained by enteroscopy confirmed the diagnosis of jejunal carcinoid tumor. The patient underwent radical jejunal resection and recovered uneventfully. In spite of the large size of the tumor, there was one solitary lymph node metastasis, but no evidence of liver metastases. This kind of jejunal carcinoid tumor, presenting with massive gastrointestinal bleeding and a subserosal bulky growth mimicking a leiomyosarcoma, has not been reported previously. Moreover, this is a rare case of a jejunal carcinoid which was diagnosed preoperatively by small bowel-endoscopic biopsy.

Adult↗
PubMed2001

Identification of a novel gene, Mblk-1, that encodes a putative transcription factor expressed preferentially in the large-type Kenyon cells of the honeybee brain.

Mushroom bodies (MBs) are considered to be involved in higher-order sensory processing in the insect brain. To identify the genes involved in the intrinsic function of the honeybee MBs, we searched for genes preferentially expressed therein, using the differential display method. Here we report a novel gene encoding a putative transcription factor (Mblk-1) expressed preferentially in one of two types of intrinsic MB neurones, the large-type Kenyon cells, which makes Mblk-1 a candidate gene involved in the advanced behaviours of honeybees. A putative DNA binding motif of Mblk-1 had significant sequence homology with those encoded by genes from various animal species, suggesting that the functions of these proteins in neural cells are conserved among the animal kingdom.

Amino Acid Sequence↗
PubMed2001

Peritoneal lavage with oxygenated perfluorochemical preserves intestinal mucosal barrier function after ischemia-reperfusion and ameliorates lung injury.

OBJECTIVE: To evaluate the effect of peritoneal lavage with an oxygenated perfluorochemical (PFC) on intestinal ischemia-reperfusion injury (IIR), we assessed intestinal barrier function in terms of bacterial translocation and endotoxemia, morphologic changes, and changes of intestinal luminal pH in rats subjected to IIR. We also examined lung injury after IIR to test the effect of oxygenated PFC lavage on remote organ failure. DESIGN: Prospective, randomized, and controlled animal study. SETTING: Laboratory of a university hospital. SUBJECT: Male Sprague-Dawley rats. INTERVENTIONS: Rats were subjected to ischemia by clipping the superior mesenteric artery. Reperfusion was achieved by release of the clip. Lavage of the abdominal cavity was performed by inflow and outflow of oxygenated PFC solution during ischemia. RESULTS: Rats undergoing peritoneal lavage with oxygenated PFC (PFC group) showed significantly better survival after IIR. The frequency of bacterial translocation and the endotoxin concentration in superior mesenteric venous blood were significantly lower in the PFC group. Luminal acidosis also was alleviated in the PFC group. Furthermore, PFC lavage preserved the intestinal mucosal architecture and inhibited interstitial edema and infiltration of inflammatory cells in the lungs. CONCLUSION: We conclude that peritoneal lavage with oxygenated PFC protects the intestinal mucosa and maintains mucosal barrier function after IIR. Preservation of the intestinal mucosa ameliorates lung injury after IIR.

Animals↗
PubMed2001

Activation of alveolar macrophages in acid-injured lung in rats: different effects of pentoxifylline on tumor necrosis factor-alpha and nitric oxide production.

OBJECTIVE: To determine whether acid instillation augments tumor necrosis factor-alpha and nitric oxide production by alveolar macrophages in rats, and to study the effects of treatment with pentoxifylline before acid instillation on the production of these inflammatory mediators. DESIGN: Controlled laboratory investigation on tumor necrosis factor-alpha and nitric oxide production by alveolar macrophages of rats that had acid-induced lung injury. SETTING: University research laboratory. SUBJECT: Alveolar macrophages of rats. INTERVENTIONS: Alveolar macrophages were recovered by bronchoalveolar lavage at 4, 10, 16, 24, and 72 hrs after unilateral hydrochloric acid (pH, 1.0; volume, 0.1 mL) instillation into the lungs of rats. Alveolar macrophages then were cultured with or without lipopolysaccharide. One group of rats was pretreated with pentoxifylline before acid instillation. MEASUREMENTS AND MAIN RESULTS: Alveolar macrophages from both acid-instilled and contralateral lungs, which had recovered 24 hrs after acid instillation, produced significantly greater tumor necrosis factor-alpha and nitric oxide. Subsequent exposure to lipopolysaccharide, as a surrogate for bacterial infection, further promoted tumor necrosis factor-alpha and nitric oxide release. Alveolar macrophages from rats pretreated with pentoxifylline before acid instillation produced significantly less tumor necrosis factor-alpha and did not overproduce tumor necrosis factor-alpha when exposed to lipopolysaccharide. In contrast, pretreatment with pentoxifylline had no effect on nitric oxide production by alveolar macrophages. CONCLUSIONS: Acid instillation stimulates alveolar macrophages to produce tumor necrosis factor-alpha and nitric oxide. Pentoxifylline preserved innate production of tumor necrosis factor-alpha to lipopolysaccharide and did not inhibit the production of bactericidal nitric oxide. This may partly explain why pentoxifylline reduces acid aspiration-induced lung injury while maintaining the host's ability to combat bacterial infection after acid aspiration.

Animals↗
PubMed2001

Complete nucleotide sequence of a Staphylococcus aureus exfoliative toxin B plasmid and identification of a novel ADP-ribosyltransferase, EDIN-C.

The complete nucleotide sequence of pETB, a 38.2-kb Staphylococcus aureus plasmid encoding the exfoliative toxin B (ETB), was determined. A total of 50 open reading frames were identified on the plasmid genome and, among these, 32 showed sequence similarity to known proteins. pETB contains three copies of IS257, which divide the pETB genome into three regions: (i) a cadmium resistance operon-containing region, (ii) a lantibiotic production gene-containing region, and (iii) the remaining part where genes for plasmid replication and/or maintenance are dispersed. In the third region, genes of various kinds of functions are present among the replication- and maintenance-related genes. They include two virulence-related genes, the etb gene and a gene encoding a novel ADP-ribosyltransferase closely related to EDIN, which belongs to the C3 family of ADP-ribosyltransferases modifying Rho GTPases. They also include genes for a cell wall-anchoring surface protein and a phage resistance protein. Based on the determined sequence of pETB, the genome structures of etb-bearing plasmids (ETB plasmids) from various clinical isolates were analyzed by the PCR scanning method. The data indicate that, although the ETB plasmids are highly heterogeneous in genome size, the fundamental genome organization is well conserved. The size variation of the plasmid is mainly attributed to defined regions which may be hot spots for gene shuffling.

Amino Acid Sequence↗
PubMed2001

Chronic NOS inhibition reverses systemic vasodilation and glomerular hyperfiltration in pregnancy.

The chronic role of nitric oxide (NO), independent of prostaglandin synthesis, in the primary peripheral vasodilation, increased glomerular filtration rate (GFR), and renal plasma flow (RPF) in normal pregnancy remains to be defined. The purpose of the present study was to chronically inhibit NOS to return systemic vascular resistance (SVR), cardiac output (CO), GFR, and RPF to nonpregnant values. Pregnant rats received the nitric oxide synthase (NOS) inhibitor, nitro-L-arginine methyl ester (L-NAME), orally from gestational days 7 through 14. Results were compared with nonpregnant and untreated pregnant rats. At 14 days gestation, CO significantly increased in pregnant vs. nonpregnant rats (187 +/- 17 vs. 125 +/- 10 ml/min, P < 0.05) as SVR decreased (0.64 +/- 0.08 vs. 1.08 +/- 0.08 mmHg. ml(-1). min, P < 0.05) and mean arterial pressure was unchanged (117 +/- 5 vs. 125 +/- 2 mmHg, not significant). Pregnant rats also demonstrated increased GFR (3,015 +/- 33 vs. 2,165 +/- 136 microl/min, P < 0.01) and RPF (7,869 +/- 967 vs. 5,507 +/- 290 microl/min, P < 0.05) vs. nonpregnant rats. L-NAME-treated pregnant rats had values for CO (118 +/- 7 ml/min), SVR (1.09 +/- 0.07 mmHg. ml(-1). min), GFR (2,264 +/- 150 microl/min), and RPF (5,777 +/- 498 microl/min), which were no different than nonpregnant animals. In summary, similar to human pregnancy, primary peripheral vasodilation occurs early in rat pregnancy. Furthermore, the hyperdynamic circulation and glomerular hyperfiltration of normal rat midterm pregnancy can be chronically reversed by NOS inhibition. These findings suggest a role for endothelial damage and decreased NO in the pathogenesis of preeclampsia.

Animals↗