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Biomedical subjects

M Mai

Publications and source records attributed to M Mai.

At least 127 records · Page 7Linked to original sources
PubMed1989

[A comparative study of the biological behavior of gastric cancer from the view of the amount of connective tissue in the cancerous tissue--a correlation between the amount of connective tissue and the metastatic pattern].

Differences between advanced gastric cancer of the medullary type (med.: 138 cases) and the scirrhous type (sci: 164 cases) with regard to the amount of connective tissue that was cancerous have been studied clinicopathologically. A correlation was found between med and liver metastasis, and sci and peritoneal dissemination in metastatic types, whereas no correlation was observed in other factors except between med and a localized type, sci and infiltrating type in gross type. The study of tumorigenicity in nude mice showed remarkable difference between med (86.7%) and sci. (0%). These results indicate that there is definite relationship between the amount of connective tissue and the biological behavior of a gastric cancer.

Adenocarcinoma, Scirrhous↗
PubMed1989

[A clinicopathological study on colonic carcinomas arising from right side colon].

This paper discusses the clinicopathological characteristics of colonic carcinomas arising from right side colon. Out of 214 cases of resected colonic carcinomas during the past 13 years, 36 cases of a right side colon carcinoma (in the cecum, in the ascending colon, or in the hepatic flexure) were encountered. Several characteristics have been associated with this type of cancer. They are as follows: 1) in half of these cases an abdominal pain but no anal bleeding, as has been noted in carcinomas of the sigmoid or rectum; 2) in histological type, poorly differentiated adenocarcinomas or mucinous carcinomas in 30.5% of these 36 cases, and associated with a far distant nodal involvement (n3, n4) in advanced carcinomas; and 3) although there was no difference in the 5-year survival rate between a right side colon carcinoma or a colon carcinoma at another site, the prognosis for those given a curative resection for a right side colon carcinoma was poor--only 22% due to hepatic metastases, indicating that colonic carcinomas of the right side has a poor prognosis due to the subsequent risk of highly potential malignancies.

Abdominal Pain↗
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↗
PubMed1988

Hepatocellular carcinoma arising in the abdominal cavity. An autopsy case of ectopic liver origin.

An unusual case of extrahepatic disseminating hepatocellular carcinoma in a 64-year-old man is reported. The initial symptom was abdominal fullness and progressive ascites. Alpha-fetoprotein in the serum was 117,000 ng/ml. Exploratory laparotomy disclosed dissemination of tumor nodules throughout the abdominal cavity without any other possible primary tumor. CT scan, ultrasonography and hepatic angiography were unable to detect any tumor lesion in the liver. The final histologic diagnosis was hepatocellular carcinoma, although at first epithelioid mesothelioma was suspected. The present case of hepatocellular carcinoma was thought to have possibly developed from ectopic liver on the peritoneum.

Abdominal Neoplasms↗
PubMed1988

Vestibulo-ocular (VOR) abnormalities at high rotational frequencies in patients with Menière's disease.

Although visual feedback is required to maintain gaze stability during low-frequency rotations (below 1 Hz) because of suboptimal VOR gain in this frequency range, such behavior is not as evident at higher frequencies. Benson and Hydén et al. noted a steady increase in VOR gain in the higher-frequency range (2 to 5 Hz), where visual feedback has little effect. Similar behavior has also been reported in the monkey models. Eleven patients with diagnoses of Meniere's disease had tests of VOR and VOR cancellations performed with the use of pseudorandom oscillations as high as 5 Hz. The responses at various frequencies were compared with normal data from 17 subjects. The VOR gain in patients exhibited a more rapid rise at high frequencies than that observed in normal subjects. For example, at 3.5 Hz the normal gain was 1.09, whereas patients exhibited a gain of 1.35 (mean of 11 subjects). When the performance during VOR cancellation tasks was compared, Meniere's patients appeared to be less able to perform these tasks; however, when the values were compared by use of a cancellation index that compensates for any difference in VOR gain, this apparent difference disappeared.

Adult↗
PubMed1988

[Effect of a conjugate of adriamycin and an antibody to human alpha-fetoprotein (AFP) on AFP-producing hepatic tumors].

We have studied the effect of an anti-FP antibody coupled via a dextran bridge to adriamycin on six AFP-producing liver tumors (3 cases with hepatoma and 3 cases with liver metastases from an AFP-producing gastric cancer). Results have revealed that MR was observed in 2 out the 5 of surviving evaluated cases. The toxicity of this conjugate was not evident in all cases, except for a low-grade fever. Further, an autopsy revealed no remarkable change in the histology of the case that had ended in death. These results indicate that this conjugate can be considered one of the treatment therapies available for a nonresectable AFP-producing tumor.

Aged↗
PubMed1988

[The correlation between the reduction rate of tumor and the survival time of patients as an effect of chemotherapy].

The correlation between reduction rate of tumor by anti-cancer chemotherapy and survival time of patients was studied in 17 cases with liver metastases from 12 stomach cancers and 5 colonic cancers. The survival time ranged from 4 to 15 months (mean 8.4 +/- 4.3 months) in 5 cases with CR or PR, from 6 to 15 months (mean 9.8 +/- 4.1 months) in 4 cases with NC, from 2 to 12 months (mean 8.0 +/- 3.7 months) in 8 cases with PD. There was no correlation between reduction rate of tumor and survival time of patients. The tumor marker doubling times, both before and after chemotherapy, were studied in 5 cases. The difference of doubling time between before and after chemotherapy was not significant. These results suggest that individual doubling time plays an important role in survival time as an effect of chemotherapy.

Aged↗
PubMed1987

Muscarine receptors on the rat phrenic nerve, evidence for positive and negative muscarinic feedback mechanisms.

Neuronal transmitter stores of the rat phrenic nerve were labelled by incubation with [3H]choline. Release of [3H]acetylcholine was elicited by electrical nerve stimulation (100 or 1,500 pulses, 5 or 25 Hz) or by high potassium (27 mmol/l) and the effects of the muscarine receptor agonist oxotremorine and the antagonist scopolamine were investigated. Neither oxotremorine nor scopolamine affected the basal tritium efflux. A low concentration of oxotremorine (10 nmol/l) enhanced and a high concentration of oxotremorine (1 mumol/l) reduced the electrically evoked [3H]acetylcholine release. Likewise, the high potassium-evoked [3H]acetylcholine release was reduced by a high concentration of oxotremorine. Both effects of oxotremorine, increase and decrease, were abolished by a pretreatment (30 min before the first stimulation period) with 0.1 mumol/l scopolamine. Scopolamine (0.1 mumol/l) alone, enhanced [3H]acetylcholine release evoked by 100 pulses (5 Hz) or by high potassium. Scopolamine, however, reduced [3H]acetylcholine release evoked by 1,500 pulses (5 Hz or 25 Hz). The concentration-response curves obtained for scopolamine under these latter stimulation conditions were flat-running and biphasic which might indicate the involvement of two opposite effects (increase and decrease) of scopolamine under the present stimulation conditions. Both effects of scopolamine were reduced in the presence of 10 mumol/l neostigmine.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1987

Conjugates of mitomycin with anti-alpha-fetoprotein antibody: antitumor effect against alpha-fetoprotein-producing human gastric carcinoma implanted in nude mice.

Conjugates of mitomycin (MMC) with an affinity-purified horse anti-human alpha-fetoprotein (AFP) antibody were prepared by direct conjugation or by indirect conjugation mediated by human serum albumin; 1a-[4-(N-succinimidoxycarbonyl)butyryl]-MMC was used in the preparation. In therapeutic experiments with athymic nude mice inoculated with the human AFP-producing gastric carcinoma OSS, the conjugates caused a greater inhibition of the tumor growth than did an unconjugated mixture of anti-AFP antibody and MMC or similar conjugates with normal horse immunoglobulin. The AFP serum level and its ratio to tumor volume were low in the group of mice treated with anti-AFP conjugate. The enhanced drug activity of the anti-AFP conjugates was not observed against human gastric carcinoma YSS (no AFP production) in nude mice; this suggests the involvement of the specific antibody-antigen interaction in the activity of the anti-AFP conjugates.

Animals↗
PubMed1987

[Clinicopathological study of AFP producing gastric cancer--significance of AFP in gastric cancer].

We experienced fifteen cases (3.9%) out of 387 with gastric cancer showing elevation of alphafetoprotein (AFP) in serum. In these cases AFP producing cells in primary lesion demonstrated positive for anti-AFP by means of immunohistochemical study. In this report, clinicopathological feature and clinical significance as a tumor marker of gastric cancer were discussed. Gross type showed Borrmann II and III which were located in atrophic area in the stomach. Histological type revealed papillary, moderately differentiated and poorly differentiated adenocarcinoma, all of which showed medullary growth in stroma. In clinical field, liver metastasis was observed in 12(80%) of 15 cases. In these cases, elevation of serum AFP was already observed before the detection of liver metastases by CT or Echo. Immunohistochemical study showed no difference between primary tumor and metastases, and no AFP positive cells were seen in 68 early gastric cancers without elevation of serum AFP.

Aged↗
PubMed1987

[Evaluation of CA 15-3 radioimmunoassay].

The CA 15-3 RIA kit (Centocor Co.) based on a solid-phase radioimmunoassay was evaluated both experimentally and clinically. The results of a basic study of the reproducibility, recovery and dilution were very satisfactory. Serum levels of CA 15-3 were determined in 211 patients with malignancies including 13 breast cancers, 81 patients with benign diseases and 13 controls. Elevated levels of this antigen (greater than 25 U/ml) were observed in 16.7% of esophageal cancers, 9.7% of gastric cancers, 7.9% of colon cancers, 10% of hepatocellular cancers, 10% of biliary tract cancers, 10% of pancreatic cancers, 33% of lung cancers, and 75% of recurrent breast cancers. Thus, in malignant diseases the positivity was low except for recurrent breast cancer. On the other hand, the false-positive rate in benign diseases was only 3.7% and the false-positive cases had a level of 40 U/ml or less. These results indicate that the serum levels of CA 15-3 may have diagnostic value in patients with recurrent breast cancer.

Antigens, Neoplasm↗