Biomedical subjects

G Asano

Publications and source records attributed to G Asano.

At least 91 records · Page 5Linked to original sources

PubMed1997

Differential distribution of ecNOS and iNOS mRNA in rat heart after endotoxin administration.

To evaluate the relationship between cardiovascular injury and the pathological significance of endothelial constitutive nitric oxide synthase (ecNOS) and inducible nitric oxide synthase (iNOS) in endotoxic shock, Wistar rats were injected intraperitoneally with 10 mg/kg Escherichia coli endotoxin and the resulting cardiovascular changes observed using immunohistochemistry, immunoelectron microscopy, the reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization at 4, 6, 8 and 10 h after endotoxin administration. Immunohistochemical and electron microscopic observations showed that ecNOS was localized in the cytoplasmic vesicles and rough endoplasmic reticulum of the endothelium of coronary arteries and intermyocardial capillaries in both control and endotoxin-treated rats. iNOS was localized in the cytoplasmic vesicles and endoplasmic reticulum of vascular endothelial cells, vascular smooth muscle cells and cardiomyocytes after endotoxin administration. The RT-PCR study confirmed the expression of ecNOS and iNOS mRNA in the heart tissues of all animals including controls. In situ hybridization showed that ecNOS mRNA was expressed in the cytoplasm of vascular endothelial cells in control and endotoxin-treated rats. After endotoxin administration, iNOS mRNA was strongly expressed in vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes and a small number of macrophages. Bacterial lipopoly-saccharide induces rapid release of nitric oxide in the microvasculature and cardiomyocytes resulting in the depression of cardiomyocyte contraction. These findings may describe the cardiac response after endotoxin treatment.

Animals↗

PubMed1997

Regenerative changes in median nerve defects using various rabbit skeletal muscles.

We examined the morphological changes of median nerve regeneration which situated to pass through degenerative latissimus dorsi and brachial triceps muscles in rabbits. Morphological observation was performed at 7, 14, 28, 45, 60 and 180 days after the creation of defect of the bilateral median nerves. Regenerative nerve fibers were observed in the residual tubes of left degenerative muscle bridges. In this respect the regenerative effect of the latissimus dorsi was better than that of the brachial triceps. These results suggest that regular and longer muscle fibers as those of latissimus dorsi may contribute to the effective regeneration of nerve.

Animals↗

PubMed1997

[Pathological findings of the liver in Hansen's disease].

In leprosy patients, granulomatous lesion are often observed, not only in skin and nerve, but also other visceral organs such as liver, kidney, spleen and cardiovascular system. But for the development of drug therapy, there are very few cases we can see the acid-fast bacilli in the lesion these days. We have reviewed the histopathological lesions in the liver of leprosy patients who had been treated for long term, based on autopsy findings of 31 cases, including 24 cases with lepromatous leprosy (LL) and 7 cases with tuberculoid leprosy (TL). Except one case of LL with progressive stage, most of them diagnosed as retrogressive or quiescent stage. Morphologically, acid-fast bacilli and granuloma were seen in a few cases of Hansen's disease. In addition, no suggestive changes of drug and virus induced liver injury were recognized. However, sclerotic change of portal vein was remarkably encountered in the tuberculoid leprosy.

Aged↗

PubMed1996

Inhibitory effect of anti-epidermal growth factor receptor antibody on a human gastric cancer.

BACKGROUND: Blockading the putative epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha)/EGF receptor autocrine pathway with anti-EGF receptor monoclonal antibody (MoAb) might prevent the growth of tumor. METHODS: The present study was designed to examine the effect of MoAb 528 on the growth of an EGF receptor which was hyperproducing human gastric cancer cells in vitro and in vivo. RESULTS: Treatment with MoAb 528 inhibited the growth of cultured cells in a dose-dependent manner. Twenty micrograms of MoAb 528 given intraperitoneally after inoculation of 1 x 10(6) cells and 200 micrograms of the MoAb 528 given after inoculation of 1 x 10(7) cells to athymic mice inhibited the growth of the xenograft. Twenty micrograms of MoAb 528 from a miniosmotic pump, which releases its contents over 2 weeks, also prevented the growth of the xenograft when the treatment was started on the day after tumor inoculation. However, no inhibitory effect was observed when the treatment was started 3 weeks after inoculation. The binding capacity of 125I-EGF on the MoAb treated tumors was diminished in comparison with control tumors. CONCLUSIONS: The results suggest that MoAb 528 blocks the EGF or TGF-alpha/EGF receptor signal pathway, resulting in the inhibition of cancer cell growth. This MoAb 528 may therefore be an effective antitumor agent against human gastric cancer that shows expression of the EGF receptor.

Animals↗

PubMed1996

Myoepithelial hamartoma of the small bowel: report of a case.

Benign small bowel tumors seldom cause symptoms, due to the fluid content and distensibility of the small bowel. We herein present the case of a solitary ileal hamartoma causing melena and abdominal pain in a 24-year-old man. The diagnosis of a submucosal ileal tumor was made after performing small bowel barium studies. Surgical treatment was undertaken, and a histological examination of the excised lesion, which showed a partially ulcerated tumor surface and extended from the submucosa to the subserosa, revealed numerous cystic glands of various sizes together with bundles of proliferating smooth muscle cells. Histochemical and immunohistochemical investigations were performed for differential diagnosis, and the tumor features were consistent with a diagnosis of ileal myoepithelial hamartoma. In the literature, small intestinal myoepithelial hamartomas are quite rare and this is the first report of a myoepithelial hamartoma causing melena.

Adult↗

PubMed1996

Expression and roles of heat shock proteins in human breast cancer.

Heat shock proteins (hsps) are thought to play important roles in the cell cycle and various processes of carcinogenesis. Therefore, we evaluated the expression of hsps, mainly hsp90 and hsp70, in human breast cancer tissues. Hsp90alpha mRNA was expressed at much higher levels in the cancerous tissue than in the non-cancerous tissue. In addition, a close correlation between hsp90alpha mRNA expression and the proliferating-cell-nuclear-antigen labeling index (PCNA LI) was observed for the cancerous tissue. These findings suggest that increased expression of the hsp90alpha isoform may play a role in cell proliferation. On the other hand, hsp90beta mRNA expression was significantly higher in poorly differentiated carcinomas than in well differentiated carcinomas of the breast. The intracellular localization of hsp70 was consistent with that of ubiquitin. In specimens showing hsp70 in the nucleus, the PCNA LI was significantly high. Hsc73 mRNA, a member of the hsp70 family, was also expressed at higher levels in cancerous tissues associated with a high PCNA LI than in non-cancerous tissues. These results suggest that hsp90alpha may play a role in cancer cell proliferation and that hsp90beta may contribute to cell differentiation and structural constitution. In addition, hsp70, especially hsc73, is related to ubiquitin and seems to be a marker for cancer proliferation.

Breast Neoplasms↗

PubMed1996

Immunohistochemical localization of tenascin, estrogen receptor and transforming growth factor-beta 1 in human endometrial carcinoma.

Tenascin is an extracellular matrix glycoprotein which plays a role in cell attachment, proliferation and migration. To elucidate the function of tenascin in the proliferation of endometrial carcinoma, we studied tenascin expression in the endometrial carcinoma of 36 cases. In 22 of the carcinomas, tenascin expression was intense in the entire extracellular space, especially at the front of muscle invasion. Furthermore, in cases with metastases, deep invasion into muscles and vascular invasion, the rate of tenascin expression was significantly high. Immunoelectron microscopy revealed the tenascin reaction product in the stroma around fibroblasts located some distance from the basal lamina of cancer cells. On the other hand, tenascin expression was found in a high proportion of cases showing weak or no expression of estrogen receptor, and intense expression of transforming growth factor-beta 1. These results suggest that tenascin not only promotes cell proliferation and invasion but also inhibits further proliferation of carcinoma.

Adenocarcinoma↗

PubMed1996

Synthesis of endothelin-1 in rat uterus during pregnancy.

Endothelin is a potent vasoconstrictive peptide first isolated from the supernatant of cultured porcine aortic endothelial cells. The purpose of this study was to determine the source of endothelin-1 (ET-1) production in rat uterus during pregnancy and to clarify its role in normal pregnancy. ET-1, as recognized by immunohistochemistry, was weakly expressed only in endometrial glandular cells in nonpregnant rats but was intensely expressed in both glandular and myometrial cells in the early postpartum period. In situ hybridization confirmed the localization of prepro-ET-1 mRNA in the cytoplasm of endometrial glandular and myometrial cells but not in stromal cells or in smooth muscle cells of blood vessels. Northern blot analysis detected prepro-ET-1 mRNA in myometrial tissue from pregnant but not nonpregnant rats. In particular, the expression of prepro-ET-1 mRNA was strongest in the early postpartum period compared with the various stages of pregnancy. These results indicate that, in addition to endothelial cells and endometrial glandular cells, myometrial cells also produce ET-1 and its production significantly increases in the early postpartum period. Therefore, ET-1 may play a pivotal role in controlling bleeding from the placental bed through myometrial contraction.

Animals↗

PubMed1996

[Three cases of adenomatoid tumor of the uterus].

Adenomatoid tumors arising in the uterus are not well-recognized and sometimes mistaken for other benign or malignant neoplasms. This study describes three cases of uterine adenomatoid tumors with clinical, light microscopic, histochemical and electron microscopical studies. Four distinctive histologic patterns (solid, adenoid, angiomatoid, cystic) were identified. Acid mucopolysaccharide was present in three cases and was digested by hyaluronidase. Immunohistochemically, tumor cells were positive for cytokeratin and vimentin. Electron microscopy revealed microvilli, intermediate filaments and dilated intercellular spaces. This gives further support to a mesothelial origin of the adenomatoid tumor. Interestingly, one case showed that the adenomatoid tumor was multiple and one nodule was connected with leiomyomatous nodule. In the other case, the tumor was large 5 x 4 x 4.5 cm). These features were unusual.

Adenomatoid Tumor↗

PubMed1996

[Effects of disease modifying antirheumatic drugs (DMARDs) and DEX on IL-1 beta and IL-6 production by IL-1 beta stimulated synovial culture cells].

UNLABELLED: To investigate the effects of disease modifying antirheumatic drugs (DMARDs) and DEX on production of IL-1 beta, IL-6 and TNF-alpha, synovial cells were observed after IL-1 beta administration in vitro. MATERIALS AND METHODS: Synovial tissue was obtained aseptically from 8 rheumatoid arthritis patients during joint surgery. The dissected tissue was treated with collagenase and adherent cells were passaged before using as samples. They were stimulated with IL-1 beta (1 ng/ml) and cultured with DMARDs and DEX in serum-free media. After 24 hours' incubation, the production of IL-1 beta, IL-6 and TNF-alpha in the supernatants was measured. RESULTS: DEX inhibited the production of IL-6. GST inhibited the production of IL-1 beta and IL-6. CONCLUSION: DEX and GST may modulate the disease activity by inhibiting the cytokine production from synovial cells.

Anti-Inflammatory Agents↗

PubMed1996

[Purification and partial characterization of a novel human platelet aggregation factor in the extracellular products of Streptococcus mitis, strain Nm-65].

In this paper, we report the purification and partial characterization of human platelet aggregation factor form the extracellular products (ECP) of Streptococcus mitis (S. mitis) isolated from a patient with Kawasaki disease (KD). Platelet aggregation reaction was carried out using platelet-rich plasma (PRP) and washed platelets suspended in ACD-PBS. The aggregation factor was designated as S. mitis-derived human platelet aggregation factor (Sm-hPAF). The results obtained were as follows. 1) Sm-hPAF was isolated by chromatography on DEAE-Sepharose CL-6 B, hydroxyapatite and Superdex 75 columns. The purified Sm-hPAF showed a single band upon SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and molecular weight of approximately 66 kDa on SDS-PAGE. The isoelectric point (pI) of Sm-hPAF was 8.5, and Sm-hPAF showed an absorption peak at 278 nm on absorption spectra. When the platelet aggregation activity of the Sm-hPAF was compared with that of ECP, the specific aggregation activity of the of Sm-hPAF was significantly increased (up to 28-fold). Sugars were not found in Sm-hPAF. The sequence of the first 15 amino-terminal amino acid residues were H.Asp-Glu-Gln-Gly-Asn-Arg-Pro-Val-Glu-Thr-Glu-Asn-Ile-Ala-Arg. The platelet aggregation activity of Sm-hPAF was inactivated by heating at 45 degrees C for 10 min. 2) PGE2 was released from platelets after incubation for 10 min with Sm-hPAF in a dose-dependent fashion. Platelet aggregation by the Sm-hPAF was totally inhibited by either PGE1, or GRGDS, but these reagents did not inhibit the platelet aggregation by collagen. 3) Histological examination of the rabbit skin sites showing an early reaction revealed increased dilatation of the veins and capillaries with cellular infiltration in the perivascular space of the dermis. Hyperplasia of the endothelial cells was noted. Degeneration of the vascular walls was observed in the later stages of the reaction. Aggregation of red cells in the vascular endothelium was also observed. Sm-hPAF was capable of producing vasculitis. 4) Twenty (76.9%) platelet-rich plasma samples (PRP) derived from 26 healthy human volunteers reacted with Sm-hPAF, but the remaining 6 PRPs were not reactive. Preliminary study suggests the existence of an inhibitory factor in plasma from nonreactive donors.

Animals↗

PubMed1996

[Role of peritoneal lavage smears and gastric wall brushing smears in gastric cancer surgery].

Examinations of peritoneal lavage smears (LC) and gastric wall brushing smear cytology (BC) appear to be important for determining accurately the stage of gastric cancer. We have been carrying out such examinations during gastric cancer surgery for 7 years. In the present study, we evaluated the results obtained from 287 patients with gastric cancer. Tumor invasion and peritoneal dissemination were correlated with a positive incidence of cancer cells in LC and/or BC. Gastric cancer showing serosal invasion was classified into positive for LC and/or BC and negative for LC and/or BC. Patients positive for LC and/or BC had a poorer prognosis. For future gastric cancer treatment, patients positive for peritoneal cytology are expected to be targeted for intensive treatment during or before surgery.

Adenocarcinoma↗

PubMed1996

[Expression of trefoil group antigen pS2 in human gastric cancer].

Expression of trefoil group antigen pS2 was examined immunohistochemically in resected stomachs from 121 patients with gastric cancer. Gastric cancer was classified as either undifferentiated or differentiated by histology, and was also divided into gastric type or non-gastric type by mucin-histochemistry. Immunoreactive pS2 was present in 20% of early cancers and 30% of advanced cancers (NS), and in 25% of undifferentiated and 15% of differentiated early cancers (NS), whereas the antigen was present in 38% of undifferentiated and 15% of differentiated advanced cancers (p = 0.04). Positivity for pS2 was found more often in gastric type early cancer (p = 0.04) as well as advanced cancer (p = 0.0002), and was also more frequent in cancers showing scirrhous (p = 0.04) and infiltrative growth (p = 0.03). Cancer positive for pS2 was characterized by mucin-histochemistry and microscopy as gastric type with scirrhous growth and diffuse infiltration, and thus the expression of pS2 in gastric cancer appears to be related to the growth of cancer with these characteristics.

Adenocarcinoma, Scirrhous↗

PubMed1995

Unilateral Multicentric Breast Carcinoma Studied by Whole Mammary Gland Serial Sectioning.

The incidence and clinicopathologic features of unilateral multicentric breast cancer (UMBC)were studied by mammary gland serial sectioning in 116 cases of clinically defined monocentric breast cancer (MONBC) examined histopathologically at the Nagano Cancer Detection Center. UMBC was defined as: 1) histopathologically discontinuous tumors each with an intraductal spread, 2)at least one tumor-free section separating two tumors, and 3) a large primary tumor and other small secondary tumors. UMBC was detected in 23 of 116 cases (19.8%), all with one secondary tumor. Primary and secondary tumors were located in the same quadrant in 34.8% and in different ones in 65.2%. The secondary tumors were < 5 mm in size in 56.5%. Secondary tumors, averaging 8.3 mm in size and 25.5 mm in distance from the primary tumor, were almost exlcusively noninvasive carcinomas, including 15 (65.4%) noninvasive ductal carcinomas and several special types. The primary and secondary tumors were of the same histologic type in 3 of 23 cases. UMBC patients averaged 6 years younger than MONBC patients, and the incidence of UMBC tended to be higher in younger patients (P<0.1). UMBC tended to occur more frequently in quadrant B with an average histologic tumor size significantly smaller than that in MONBC (P <0.01). The histologic types of the primary tumor in UMBC and MONBC were similar, with common types predominant. Lymph node metastases tended to be slightly more frequent in MONBC. This high incidence of UMBC calls for careful attention when considering breast conserving therapy.

Journal Article↗

PubMed1995

[Two autopsy cases of malignant mixed müllerian tumor of the uterus with metastasis to alimentary tract and liver].

Two autopsy cases (69 and 87-year-old women) of malignant mixed müllerian tumor (MMMT) following radiation therapy for uterine cervical cancer sixteen and twenty years ago respectively were reported. They were admitted due to abdominal pain and diagnosed as ileus. In the first case, CT examination revealed a tumor measuring about 8 x 10 cm in size in the uterine posterior wall. Recurrence of the uterine cancer was suspected and hysterooophorectomy combined with sigmoidectomy was performed. In the second case, artificial anus formation was performed because of sigmoid stricture by the invasion of the tumor. Histologically, tumors in both cases were composed of carcinomatous and sarcomatous components including heterologous elements such as cartilage. The patients died of extensive spreads and metastasis in the liver and alimentary tract.

Aged↗

PubMed1995

Cell damage and liberation of nitric oxide synthase in rat heart induced by endotoxin administration.

To evaluate the relationship between cardiovascular injury and the pathological aspect of the liberation of the nitric oxide synthase in endotoxin shock, Wistar rats were injected intraperitoneally with 10 mg/kg E. coli endotoxin and the cardiovascular changes were observed chronologically by immunohistochemical and electron microscopic techniques at 2, 4, 8 and 12 h respectively after endotoxin administration. Light microscopically, irregular contraction of cardiomyocytes was observed in the early stage. After 8 h of endotoxin administration, occasional disintegration of the myocytes as well as lysis of myofibrils became prominent, and diminished stainings of myoglobin and actin were seen in these myocytes. Ultrastructurally, increased pinocytotic vesicles were observed in endothelial cells associated with widened intercellular spaces, and vacuolization of endothelial and medial cells of the vasculature. In cardiomyocytes, swelling of mitochondria and interstitial edema were noted at 12 h after endotoxin administration. Immunohistochemically, an increased permeability of albumin was noted in the myocytes and vasculature and nitric oxide synthase was localized on the cytomembrane of the endothelium of the coronary arteries in control rats. After endotoxin administration, the reaction products of nitric oxide synthase increased in the endothelial and medial cells, and cardiomyocytes. These results suggest that the increased activity of nitric oxide synthase is an important factor in the excessive production of nitric oxide and in promoting the pathologic changes in the cardiovascular system after endotoxin administration.

Animals↗

PubMed1995

[The dermal connective tissue of long quiescent leprosy patients. Part 2. Comparison of the volumes of collagen with those of elastic fibers].

We studied dermal connective tissue of leprosy patients(Pa) in inactive condition. The dermal thickness(D) and the volumes of collagen and elastic fibers were measured utilizing automated computerized image analyzer. The length of each elastic fibers(E) in lower legs were also measured. The E in upper dermis of forearms were observed microscopically. All these were compared with age-matched control(Co). We got the following results accordingly. There was a relative increase of E in Pa's limb skin in spite of greatly decreased dermal thickness and fibrous components. The influence of sun exposure could not be recognized in this result. Each elastic fibers of Pa were longer than that of Co. The increased E in upper dermis was evident in Co's forearms, but not in Pa's. From our results, it is conceivable that the Pa's E either outlast or are overproduced exceedingly the collagen fibers. The factors that may account for these results are remained to be clarified.

Aged↗

PubMed1995

[Intraepidermal mass of M. leprae in a case of seborrheic keratosis due to Hansen's disease (LLs)].

A 67-year-old patient has had exanthema in the lower right limb since 51 years ago (16 years old at onset), which underwent repeated remission and recurrence. At present, he has bilateral symmetrical widespread infiltrating exanthema and asymmetrical marked neuralhypertrophy, and has been diagnosed typical LLs (His father had the same disease). The exanthema recurred several years ago, and the patient is being treated for Hansen's disease. He had a dark brown flat elevation with a rough surface and the size of a small finger tip in his right abdominal skin for approximately 20 years. A biopsy was performed, and the specimen was fixed in 10% formalin and paraffin sections were prepared for histopathologic examination. A part of the specimen was processed forscanning electron microscopic examination. Seborrheic keratosis was diagnosed by H & E staining. Acid-fast (FITE) staining, immunohistochemical staining (keratin, S-100 protein, anti-PGL antibody and anti-BCG antibody) and scanning electron microscopy revealed the presence of bacteria (M. leprae) in the dermal foam cells, the matrix with a banded structure and the squamous epithelial cells which normally lack phagocytosis function. Compared to the basal cells of normal epidermis, the basal cells located adjacent to the dermis affected with seborrheic keratosis showed increased proliferation and more marked characteristics of a germinative cell. The degree of differentiation of the basal cells appeared regressed, and they probably possessed augmented phagocytic activity. The phagocytosed bacteria were probably carried by the epidermal cell cycle toward the surface layer. However, bacteria could not be found in the stratum corneum, probably due to an association with the lysosome.

Aged↗