PubMed Health⌕ Search

Biomedical subjects

A Ooi

Publications and source records attributed to A Ooi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Integrin distribution in gastric carcinoma: association of beta 3 and beta 5 integrins with tumor invasiveness.

Immunolocalization of a variety of integrins using monoclonal antibodies against beta 3, beta 5, alpha 3 beta 1 and alpha 6, and polyclonal antibodies against vitronectin receptor (alpha v beta 3) and beta 1 were investigated on PLP-fixed paraffin sections of 19 cases of advanced gastric carcinomas. The beta 5 integrin, which pairs only with the alpha v subunit, was positive in seven cases (37%), and was associated closely with scirrhous invasion (P < 0.05). beta 5 was positive chiefly in the cytoplasm of carcinoma cells and infrequently in cell membranes. beta 3, which is another subunit pairing with alpha v, was positive in six cases (32%), and tended to be associated with scirrhous invasion (P < 0.01). beta 3 was also located chiefly in the cytoplasm. Five of the seven beta 5-positive cases showed coexpression of beta 3. Polyclonal antibodies to alpha v beta 3 also showed a significant difference among the amounts of stroma (P < 0.05). Anti-beta 1 antibodies showed clear positivity in many cases (89%). Of the beta 1 integrins, alpha 3 beta 1 was positive in a few cases (26%) without any preferential pattern, and laminin receptor subunit alpha 6 stained on cell membranes of neoplastic epithelia in many cases of carcinoma (89%) except for mucinous carcinoma These distinctive patterns of integrin positivity indicate a close association of beta 5 and beta 3 expression with scirrhous invasion in gastric carcinoma.

Adult↗
PubMed1994

Detection of human cytomegalovirus, Epstein-Barr virus, and herpes simplex virus in diffuse interstitial pneumonia by polymerase chain reaction and immunohistochemistry.

Using formalin-fixed and paraffin-embedded tissues from autopsy, the authors examined infection by human cytomegalovirus, Epstein-Barr virus, and herpes simplex virus in 54 patients with primary or secondary diffuse interstitial pneumonia (DIP) by polymerase chain reaction and immunohistochemistry and compared it with that in 32 persons without lung complications. Polymerase chain reaction and immunohistochemistry demonstrated that approximately 40% and 30% of DIP were positive for human cytomegalovirus and Epstein-Barr virus, respectively, but none of 32 controls had evidence of infection by human cytomegalovirus and Epstein-Barr virus. The polymerase chain reaction was more sensitive than the immunohistochemical technique for detection of herpes simplex virus. The former technique revealed herpes simplex virus infection in approximately 90% of DIP and controls and the latter in approximately 50% of each group. However, immunohistochemistry had the advantage of demonstrating the morphologic location of infected cells and of allowing their semiquantitative evaluation. Herpes simplex virus was more extensively distributed in the lungs of several DIP cases than in those of controls, suggesting the reactivation of herpes simplex virus. Only DIP patients (31 cases [57.4%]) were infected by two or three kinds of herpesviruses. The combination of polymerase chain reaction and immunohistochemistry revealed that these herpesviruses proliferated in many cases of DIP.

Base Sequence↗
PubMed1992

Gastric carcinoma cells with endocrine differentiation show no evidence of proliferation.

The proliferative activity of gastric cancer cells with endocrine features was evaluated in five cases by means of a double-immunostaining procedure. The endocrine cells were recognized by a monoclonal antibody to chromogranin A (CGA) and the proliferative activity by a monoclonal antibody to proliferating cell nuclear antigen (PCNA). With the use of two different chromogens it was easy to determine whether CGA was located in the cytoplasm and whether PCNA was located in the nucleus of the same section. The CGA-positive endocrine cells of the normal gastric antral mucosa could be readily distinguished from the PCNA-positive cells scattered in the mucosal neck zones. Over 1,000 CGA-positive cancer cells were counted per case. A few cells (average, less than 1.0%) exhibited faint nuclear staining with anti-PCNA; in no instance was unequivocal PCNA reactivity demonstrable in the gastric cancer cells with endocrine differentiation. By contrast, the PCNA reaction was positive in one fourth to one third of the other cancer cells. These observations suggest that gastric cancer cells with endocrine features are differentiated and do not participate in the cell cycle.

Cell Division↗
PubMed1992

Malignant schwannoma with rhabdomyoblastic and melanocytic differentiation.

This is the first case report of an unusual malignant tumor with components of malignant schwannoma, rhabdomyosarcoma, and melanoma, occurring in an adult. The tumor was observed in the left temple in a 35-year-old man without von Recklinghausen's disease. The possible derivation of this tumor from primitive neuroectodermal cells is discussed.

Adult↗
PubMed1991

Predominant Paneth cell differentiation in an intestinal type gastric cancer.

A distinct morphological variant of a diffuse type adenocarcinoma of the stomach with Paneth cell differentiation is reported. The tumor was a Borrmann's Type III carcinoma measuring 6.0 x 5.5 cm at the body along the greater curvature. It was composed of Paneth cell- and endocrine cell differentiated cancer cells in addition to tubular and poorly differentiated adenocarcinoma cells. The Paneth cell differentiation was characterized histologically by cytoplasmic distinct coarse eosinophilic granules stained red with periodic acid-Schiff and Masson trichrome reagents and reddish brown with phosphotungstic acid hematoxylin, and electron microscopically by lysozyme in cytoplasmic electron dense granules. In addition, electron microscopy revealed acid mucin globules and various intermediate forms between Paneth granules and the mucin globules which might be regarded as abortive forms of Paneth granules presumably resulting from defective incorporation of lysozyme-positive mucosubstances into acid mucin. Endocrine differentiated cancer cells consisted of serotonin-, peptide YY-, and glucagon/glicentin-positive cells. The various cell phenotypes found in the present tumor could be explained on the basis of intestinal differentiation of gastric cancer.

Adenocarcinoma↗
PubMed1991

Analysis of gastric carcinoma growth by endoscopic ultrasonography.

Endoscopic ultrasonography (EUS) was performed preoperatively in 82 patients with gastric carcinoma (40 with early and 42 advanced malignancy). Measurements of wall thickness were performed in each case and showed good correlation with histological findings. Wall thickening was found to consist of both tumorous and accompanying ulcerous tissue. Thus, increasing wall thickness, as demonstrated by EUS, may not necessarily mean progressive tumor growth. The EUS features of gastric carcinoma were analyzed and four distinct growth patterns found: predominantly intramural (IM) or intraluminal (IL) growth with preservation (Type 1) or destruction (Type 2) of the submucosal echo-rich layer. All early carcinomas displayed the IL-type growth pattern on EUS (98% IL1-type) and 81% of advanced tumors showed IM-type features. EUS was able to differentiate between early and advanced carcinoma in 98% of cases. The EUS pattern of submucosal destruction (type IM2 or IL2) corresponded to the expanding type tumor according to Ming's histopathological classification. On the other hand, 24 of 26 infiltrative tumors according to Ming were found on EUS to have an intramural growth pattern with preservation of the submucosa (type IM1). It is concluded that EUS is highly sensitive in predicting the tumor growth pattern in gastric carcinoma, providing important additional information to the currently used TNM staging system. Measurements of wall thickness are reliable but differentiation between tumorous growth and peritumorous changes is not possible.

Carcinoma↗
PubMed1991

A limitation of endoscopic ultrasound: an unusual case of early gastric cancer overlying a pancreatic rest.

Endoscopic ultrasonography (EUS) has been developed as a valuable tool for examining the depth of carcinoma invasion and evaluating the submucosal tumors of the gastrointestinal tract. In the present case, that of a 60-yr-old woman, the work-up of radiography and conventional endoscopy revealed an ulcerating cancer of the stomach. Subsequent EUS showed a solid high-echoic mass occupying the third (submucosal) and fourth (muscularis propria) layers of gastric wall, suggestive of an advanced cancer invading the muscularis propria. However, histologic examination of the surgical specimen showed that this tumor was early submucosal carcinoma confined to the surface of a pancreatic rest. Retrospective evaluation of EUS pictures proved that the mass had tubular or circular echoless structures associated with thickening of the fourth layer, suggesting the pancreatic rest. Our experience in reviewing EUS findings of this tumor seems noteworthy, inasmuch as EUS indicates that EUS may provide certain characteristic features of gastric pancreatic rest that should be differentiated from invading carcinoma.

Carcinoma↗
PubMed1990

Expression of placental alkaline phosphatase in gastric and colorectal cancers. An immunohistochemical study using the prepared monoclonal antibody.

The authors developed monoclonal antibodies (MoAb) against human placental alkaline phosphatase (PLAP). Four specific MoAb reacting only with PLAP and two nonspecific MoAb reacting equally with isozymes of alkaline phosphatase (hepatic, intestinal, and placental) were obtained. Immunohistochemical staining with the specific MoAb showed that the cell membrane and cytoplasm of cancer cells were stained in gastric and colorectal carcinoma. The incidence of PLAP positivity was 23% (25 of 107) of all gastric carcinomas. Among gastric carcinomas, the 42% (13 of 31) positivity of highly differentiated carcinoma (papillary adenocarcinoma and well-differentiated tubular adenocarcinoma) was a significantly higher rate than that found in poorly differentiated carcinoma (poorly differentiated adenocarcinoma and signet-ring cell carcinoma, five of 41, 12%). The incidence of PLAP positivity was 11% (four of 35) in colorectal carcinoma. In contrast, gastric adenoma, intestinal metaplasia, and noncancerous tissue adjacent to cancer did not show staining. These results indicated that expression of PLAP was apt to occur in more highly differentiated gastric carcinoma and was highly specific for carcinoma in the gastrointestinal tract, although its incidence was not high.

Alkaline Phosphatase↗
PubMed1990

Medullary carcinoma with lymphocytic infiltration of the stomach. Clinicopathologic study of 27 cases and immunohistochemical analysis of the subpopulations of infiltrating lymphocytes in the tumor.

The current study attempts to clarify the possible immune response that occurs in medullary carcinoma with lymphocytic infiltration of the stomach by an immunohistochemical analysis of the subpopulations of tumor-infiltrating lymphocytes. This carcinoma was histologically characterized by the sparse population of small nests consisting of poorly differentiated carcinoma cells, widely separated by intervening nondesmoplastic stroma infiltrated uniformly with abundant lymphocytes frequently accompanied by lymph follicles. An immunohistochemical analysis revealed that T-cells were evenly distributed throughout the tumor with intimate contact with individual carcinoma cells, except the lymph follicles consisted mainly of B-cells. Because of the similarities of morphologic features and subpopulations of tumor-infiltrating lymphocytes of this carcinoma to the normal lymphoid tissue, an organized immune response combined with cell-mediated and humoral immunities against the invading carcinoma cells seemed to occur in this type of gastric carcinoma, resulting in a excellent prognosis compared with that in ordinary gastric carcinoma.

Adult↗
PubMed1990

Alpha-fetoprotein (AFP)-producing gastric carcinoma. Is it hepatoid differentiation?

Biochemical and immunohistochemical analyses were done on five cases of gastric carcinoma with excessive production of alpha-fetoprotein (AFP). Histologic and ultrastructural examination of these cases showed conventional poorly differentiated adenocarcinoma of cuboidal or polygonal tumor cells in the medullary area with scattered AFP-positive cancer cells. Comparative studies on serum AFP between these cases and in hepatocellular carcinoma (HCC) or in testicular yolk sac tumor cases using concanavalin A (ConA)-affinity and lens culinalis agglutinin A (LCA)-affinity sepharose columns revealed that the AFP derived from four cases had a high ConA nonadsorping rate and high LCA-reactive fraction similar to that of yolk sac tumor. The AFP from one case had a small LCA-reactive fraction similar to that of HCC. Further immunohistochemical study using several markers for liver cells or germ cell tumor did not show additional evidence of these tumor cells to differentiate into liver cells or yolk sac tumor cells. Thus, this study indicates that AFP-producing gastric carcinomas are not always derived from hepatoid differentiation of the foregut. These gastric carcinomas might be categorized into medullary tumor with gastrointestinal tract-specific AFP.

Adenocarcinoma↗
PubMed1990

[Study on neoadjuvant chemotherapy of Borrmann 4 type carcinoma of stomach and its clinical significance].

Considering a high potential of biological malignancies of Borrmann 4 type carcinoma (abbr., Borr. 4) of the stomach, preoperative induction (neoadjuvant) chemotherapy was applied to patients with Borr. 4 as an initial therapy. Anticancer drugs used in this study were FAM-OK432, sequential MTX-5Fu or UFT-M through aortic infusion or induced hypertension chemotherapy (IHC) in order to obtain selective enhancement of drug delivery into tumor tissue. These trials were carried out on 24 patients who had Borr. 4 type carcinoma. The response to neoadjuvant chemotherapy showed CR in 1 case, PR in 3 cases and MR in 4 cases. The objective improvement except the primary gastric lesion showed shrinking of distant metastatic lymph nodes along paraaorta or Virchow of 50% (5/10), disappearance of pleural or peritoneal fluids 85. 7% (6/7) and marked decrease of tumor marker such as CEA, CA19-9 or CA125 100% (12/12). In one of 5 cases showing morphological improvement of primary gastric lesion, no viable cancer cells were seen in the stomach associated with multiple foci of granulofibromatous lesion of regional nodes. In 17 cases of 24 total gastrectomy was done with extended lymphadenectomy (R2-R3). While there was no difference in the median survival time (MST) among curable resection group, MST of non-curable resection group with neoadjuvant chemotherapy showed a fairly good prognosis for 14 months as compared to that of 4 months without chemotherapy. As for disease-free survival, patients whose tumor showed a high response to neoadjuvant chemotherapy had a good prognosis in non-curable resection group (p less than 0.01). In conclusion our results demonstrated that patients whose tumor were effectively destroyed by neoadjuvant chemotherapy against Borr. 4 carcinoma of stomach had an improved prognosis.

Adult↗
PubMed1990

The effect of UFTM therapy on primary and metastatic colon cancer from the same human xenotransplanted into nude mice.

Successful simultaneous transplants of a cancer of the ascending colon from a 60 year old woman, taken from 3 sites: the primary focus, a lymph node metastasis, and a hepatic metastasis, into nude mice yielded KHC (-P, -N, -H) strains. These three strains were compared under uniform conditions of nude mouse transplantation from the standpoints of morphological variation, growth rate, and sensitivity to chemotherapy. The results showed no major differences in morphology or growth rate. However, an effect on chemotherapeutic sensitivity was observed in KHC-P and KHC-N, with reduction rates of 25.8 per cent and 31.4 per cent, respectively, in the MMC only treatment group with large doses, and in KHC-N and KHC-H, with reduction rates of 46.5 per cent and 34.9 per cent, respectively, in the UFTM group. Chemotherapy sensitivity not only exhibited heterogeneity by site, but also differed according to the chemotherapeutic agent used. These results indicate that this method of nude mouse transplantation is a good experimental system for comparing primary foci and metastases under uniform conditions, and also strongly suggest the presence of heterogeneity in sensitivity to chemotherapy.

Adenocarcinoma, Mucinous↗
PubMed1990

Evidence for the existence of two equilibrium conformations of the ternary complex of myosin subfragment-1, ADP, and orthovanadate.

In order to investigate the flexibility of the ternary complex consisting of myosin subfragment-1 (S1), ADP, and orthovanadate (Vi), i.e., S1.ADP.Vi, the exchangeability of the bound ADP was examined. After isolation of the ternary complex of S1.ADP.Vi by gel filtration, 3'-O-(N-methylanthraniloyl)-ADP (Mant-ADP), a fluorescent analogue of ADP, was added at 0.5 degrees C. The added Mant-ADP was incorporated into the ternary complex very slowly by replacing the bound ADP. The nucleotide exchange occurred without regeneration of the ATPase activity of S1. Similarly, the ternary complex of S1.Mant-ADP.Vi prepared and isolated by gel filtration according to Hiratsuka (3, 4), was incubated with ADP (2.4 mM) at 4.5 degrees C. The nucleotide exchange of S1.Mant-ADP.Vi with ADP occurred in two phases with the apparent rates of 4.5 x 10(-4) s-1 (the fast phase) and 6.7 x 10(-6) s-1 (the slow phase). Biphasic exchange of the bound nucleotide was also observed with S1(A1) isozyme, indicating that the biphasic exchange did not correspond to two S1 isozymes. The apparent rates of the fast and the slow phases increased with the concentration of the added ADP, but they became saturated at an ADP concentration of the order of 2 mM, indicating that the nucleotide exchange reaction involves a step (or steps) which is insensitive to the concentration of free ADP in the solution. This step might be a reversible isomerization.

Adenosine Diphosphate↗
PubMed1990

Biological and clinicopathological significance of endocrine differentiation of gastric adenocarcinoma evaluated by double immunohistochemical labeling for chromogranin A and bromodeoxyuridine.

To elucidate the biological and clinicopathological significance of endocrine differentiation in gastric adenocarcinoma, an immunohistochemical study was made of 127 cases with ascertained five-year survivals, and of 45 recent cases of bromodeoxyuridine (BrdU) labeling. Endocrine differentiated cancer cells were demonstrated in 37 out of the 127 cases (29.1%) evaluated by chromogranin A (CGA) immunoreactivity, and all CGA-positive tumors were classified as advanced gastric cancer. Analysis of retrospective five-year survival rates revealed the adenocarcinomas with endocrine differentiation to have had significantly longer survival times than those without endocrine immunoreactivity in stage II, but not in stages III or IV. Double immunolabeling for CGA and BrdU in the other 45 adenocarcinoma cases showed only a single CGA-positive cancer cell with BrdU incorporation among a total of 454 CGA-positive cells examined. There was no significant difference between the labeling indices of the general cancer population and the cancer cells adjacent to CGA-positive cells. In conclusion, endocrine differentiation of gastric cancer is not uncommon, particularly in advancing cancer, and it would be a useful marker for a better prognosis in stage II. Probably, endocrine differentiated cancer cells are almost dormant with virtually no DNA synthesizing activity, and their paracrine effect is most unlikely to work in vivo.

Adenocarcinoma↗
PubMed1989

Ca2+-dependent regulation of the dynamic polarity of F-actin under the influence of tropomyosin and troponin.

A novel method that we have developed in the preceding paper to study the subunit exchange rates of F-actin (N. Suzuki and K. Mihashi, Biophys. Chem. 33 (1989) 177) was applied to regulated F-actin (a complex of F-actin, tropomyosin and troponin). We found that the dynamic polarity of regulated F-actin is modulated in a Ca2+-dependent manner, giving rise to strong suppression of the on/off rates of subunit exchange at the P-end. We interpreted this characteristic suppression as follows. Removal of Ca2+ from troponin C in regulated F-actin produces strong constraints on fluctuations in potential energy of an intermediate conformation of the terminal structure (P-end) which would be formed in the course of association and dissociation of the actin subunit.

Actins↗
PubMed1988

Endocrine differentiation of gastric adenocarcinoma. The prevalence as evaluated by immunoreactive chromogranin A and its biologic significance.

The prevalence of endocrine differentiation of conventional gastric adenocarcinoma was evaluated on the 212 cases (including 62 mucosal carcinomas) of consecutively resected stomach for adenocarcinoma in our hospital using anti-chromogranin A (CGA) antibodies. CGA-positive cells were found in 28 of 150 cases (18.7%) as an integral tumor component. In immunocytochemistry and electron microscopic examinations, we could classify these 28 cases into three groups according to the distribution patterns of CGA-positive cells. The first group consisted of 12 cases in which scattered CGA-positive cells were located in neoplastic glands. The second group consisted of six cases of scirrhous carcinoma in which CGA-positive cells were separated by fibrovascular tissue. The third group consisted of ten cases in which the positive cells were present in clusters. No definite correlation was recognized between the appearance of CGA cells and histologic types of predominance. In the analysis of the hormonal substances coexpressed by CGA-positive cells, immunoreactive serotonin (SER) was found most frequently, and somatostatin (SS), gastrin (GAS), glucagon/glicentin (GLU/GLI), and peptide-tyrosine-tyrosine (PYY) like immunoreactivities were found in a few tumor cells. CGA-positive cells occupied limited parts of the tumors in most cases, and they were noticeably more frequent in advanced stage cases. This might explain why endocrine differentiation reflects the dysexpression of the neoplastic stem cells. Furthermore, absence of mitotic figures in this type of cell and negativity of a single colony composed exclusively of CGA cells in metastatic foci suggested that these cells are in a dormant phase and are probably postmitotic.

Adenocarcinoma↗
PubMed1988

Desmoplastic reaction of gastric carcinoma: a light- and electron-microscopic immunohistochemical analysis using collagen type-specific antibodies.

The desmoplastic reaction in ten cases of gastric carcinoma was investigated light and electron immunohistochemically by using monospecific antibodies to collagen types. In addition to type I and III collagens, type V collagen was constantly recognized in the fibrous stroma, increasingly of the scirrhous carcinoma. Type IV collagen delineated the basement membranes of carcinoma nests linearly with occasional discontinuity, whereas in the scirrhous carcinoma, it was present along the thick bundles of collagenous fibers. Immunoelectron microscopic studies revealed that type I and III collagens were distributed on the collagen fibers, and type V collagen was stained in the margin of these fibers. These antibodies also reacted in the rough endoplasmic reticulum of fibroblasts or myofibroblasts in a few cases. Type IV collagen was localized in the periphery of smooth muscle cells, endothelial cells of collapsed capillaries, and myofibroblasts scattered in the stroma of scirrhous carcinoma. Carcinoma cells were not reactive with any antibodies examined. These findings suggest that type V collagen, as well as type I and III collagens, is involved in the formation of desmoplastic stroma, and that these collagens are reactively synthesized by fibroblasts and myofibroblasts in some interaction with invading carcinoma cells.

Animals↗