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Biomedical subjects

M Mai

Publications and source records attributed to M Mai.

At least 91 records · Page 5Linked to original sources
PubMed1993

Early interstitial changes in hypertension-induced renal injury.

To elucidate the mechanisms of hypertensive renal injury, we investigated the time course and extent of changes in matrix composition, as well as cell proliferation and infiltration in two-kidney, one clip rats. The nonclipped kidneys from hypertensive and sham-operated control rats (n = 5 to 10 in each group) were studied at 7, 14, 21, and 28 days after clipping. Systolic blood pressure was elevated by day 7 (154 +/- 3 versus 111 +/- 4 mm Hg in sham group, P < .001, n = 10 each). Hypertension resulted in an early expansion of the interstitial volume by 37%, whereas hypertensive vascular changes and glomerular injury did not become evident until day 21. Immunofluorescence studies revealed an early interstitial accumulation of collagens I, III, IV, V, VI, and fibronectin by day 7. In contrast, the glomeruli showed a mild to moderate increase in collagens I, III, IV, V, laminin, and fibronectin but not collagen VI later in the established phase of hypertension. Staining for proliferating cell nuclear antigen as a marker of cell replication was increased in tubular epithelial but not interstitial or glomerular cells. A progressive infiltration of macrophages (16 +/- 2 versus 9 +/- 1 ED1+ cells/mm2, P < .05, n = 6) and T lymphocytes (93 +/- 15 versus 74 +/- 7 CD4+ cells/mm2, n = 8) in the cortical interstitium had already occurred by day 7. On the other hand, only macrophages increased in number within the glomeruli. Thus, renovascular hypertension leads to an early tubular cell proliferation, mononuclear cell recruitment, and deposition of matrix proteins primarily within the interstitium. We conclude that the injury producing nephrosclerosis in this model extends far beyond the glomeruli. Both the tubules and the interstitium are actively involved and may be the more important initial sites of injury.

Animals↗
PubMed1993

Rapidly growing mucinous cholangiocarcinoma.

A 65-year-old man was hospitalized due to an abdominal tumor. Several imaging studies showed multilocular tumors in the right hepatic lobe and in the pancreatic head, 4 and 7 cm in size, respectively. The hepatic tumor rapidly grew to 9 cm in 4 weeks, associated with a rapid increase in the serum carcinoembryonic antigen level from 125 ng/ml to 1,000 ng/ml. The pathologic diagnosis of the resected liver tumor was mucinous cholangiocarcinoma. This hepatic tumor produced a large amount of mucin, but did not secrete mucin into the bile ducts. Therefore, there was no obstructive jaundice. The incidentally accompanied pancreatic tumor was a typical serous cystadenoma. The present case suggested that mucinous cholangiocarcinoma could present rapid growth of the tumor. The clinicopathological features of mucinous cholangiocarcinoma are demonstrated for the first time, and the differences between mucinous cholangiocarcinoma and mucin-producing papillary adenocarcinoma of duct-spreading type are discussed.

Adenoma, Bile Duct↗
PubMed1993

[Prediction of recurrence of gastrointestinal cancer from standpoint of biological malignancies--tumor marker doubling time and its a half life period line].

It is well generally accepted that several tumor markers may be useful for determination of staging, metastatic patterns, devices of the malignancy and prediction of recurrence in postoperative follow-up. Our analysis of tumor markers in gastrointestinal cancer indicated that the patients who had a high level of AFP in the serum of gastric cancer patients showed a correlation between preoperative AFP level and liver metastasis. In patients with carcinomatous peritonitis positive rate of CA125 level in serum was 42.9% and, more importantly, the elevation of CA125 level after surgery was observed in 72.2% of patients complicated peritoneal dissemination before clinical evidence. On the other hand, the change of tumor marker levels in serum after surgery were plotted on a semi-logarithmic scale and we monitored tumor marker changes until the level decrease to the normal range or when recurrence was detected on imaging diagnosis. All patients showing high levels of CEA had surgical resection for gastrointestinal cancers. In the group of 25 patients who had no recurrence within 1 year or more, CEA levels decreased exponentially until these reached the normal range. The half life period of CEA was 4 to 5 days. However, CEA levels in 13 of 19 patients who recurred showed a dissociation from the theoretical line of half life period before the level decreased to normal range. We interpreted that this dissociation was caused by the growth of residual cancer cells. In other word, if dissociation point from exponential decrease line of CEA were pointed after the surgery, we can predict a possibility of recurrence in earlier period after surgery.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

A study into the phenomenon of head-shaking nystagmus: its presence in a dizzy population.

In this paper we have prospectively analyzed results from approximately 1,500 patients who underwent a head-shaking test during routine electronystagmography (ENG). The incidence of head-shaking nystagmus (HSN) in a dizzy population was relatively high (31.7%) when compared to other so-called abnormalities in the routine ENG test battery. Its presence was also similar in both active vs. passive head-shake tests. When present, different types of HSN were identified (monophasic (76.8%), biphasic (22.7%) and triphasic (0.5%)). In some cases, reversals of the expected "normal" pattern occurred. A high correlation was found to exist between a positive head-shake test and the presence of spontaneous nystagmus, positional nystagmus and caloric test abnormalities.

Adolescent↗
PubMed1993

Early invasive colorectal carcinomas metastatic to the lymph node with attention to their nonpolypoid development.

Clinicopathologic study of six cases of early invasive colorectal carcinoma metastatic to lymph node was performed in order to elucidate possible characteristics relating to the risk of metastasis, with particular attention to the growth pattern of the primary tumor. All of the cases had at least one of the well-known risk factors for lymph node metastasis, including moderately or poorly differentiated histologic characteristics, considerable degree of submucosal invasion, and lymphatic invasion. An interesting finding of the present study was the identification of a nonpolypoid growth pattern with no concomitant adenomatous tissue, which seemed to be different from that of "malignant polyps" of previously reported cases showing adenoma-carcinoma sequence. This unique growth feature was found in all of the cases. Therefore, in addition to the accepted risk factors, nonpolypoid growth pattern and absence of adenomatous component may be risk factors predictive of nodal metastasis in patients with early invasive colorectal carcinoma.

Adenocarcinoma↗
PubMed1992

Tumor necrosis factor alpha and interferon gamma synergistically induce interleukin 8 production in a human gastric cancer cell line through acting concurrently on AP-1 and NF-kB-like binding sites of the interleukin 8 gene.

Interleukin 8 (IL-8) is a novel cytokine which possesses neutrophil chemotactic and activating activities in addition to chemotactic activity for basophils and T lymphocytes. It has been shown that IL-8 is produced by a variety of human somatic cells including monocytes/macrophages, dermal fibroblasts, vascular endothelial cells, keratinocytes, mesangeal cells, and several types of tumor cell lines. We have examined here whether or not human gastric cancer cell lines produce IL-8 in vitro. The production of IL-8 protein was detected by enzyme-linked immunosorbent assay in the culture supernatants derived from eight of nine human gastric cancer cell lines stimulated with either interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha), or TNF alpha plus interferon gamma (IFN gamma). In some of the gastric cancer cell lines such as MKN 45 and KATO, TNF alpha plus IFN gamma synergistically induced the production of IL-8. In MKN 45 cells, synergistic increase of the steady state level of IL-8 mRNA by TNF alpha plus IFN gamma was not inhibited by cycloheximide treatment. Scatchard analysis revealed that IFN gamma changed neither the number nor the affinity constant of TNF alpha binding sites on a gastric cancer cell line, suggesting that the synergism was a post-receptor event. Furthermore, synergistic induction of chloramphenicol acetyltransferase activity by TNF alpha plus IFN gamma was observed in MKN 45 that were transiently transfected with chimeric chloramphenicol acetyltransferase reporter genes driven by the transcriptional regulatory region of human IL-8 gene. Through the mutation of the regulatory region of the IL-8 gene, both AP-1- and NF-kB-like factor binding elements were presumed to be involved in conferring the responsiveness to TNF alpha plus IFN gamma. Moreover, gel retardation analyses revealed that TNF alpha and IFN gamma synergistically induced the binding of NF-kB like as well as AP-1 like proteins bound to these sites. These results indicated that IFN gamma synergistically enhanced TNF alpha-induced IL-8 production in a human gastric cancer cell line through synergistic activation of transcription factors without up-regulating TNF alpha receptor.

Base Sequence↗
PubMed1992

Evaluation of basic procedures for adoptive immunotherapy for gastric cancer.

Peripheral blood lymphocytes (PBL) of gastric cancer patients in advanced stages showed lymphokine activated killer (LAK) activities comparable to those of healthy donors, suggesting potential applicability of LAK cells induced from PBL stimulated with recombinant interleukin-2 (rIL-2) in adoptive immunotherapy (AIT) for gastric cancer. In order to generate a large number of LAK cells from PBL, lymphocytes were cultured with both rIL-2 and phytohemagglutinin (PHA). In this culture, the numbers of cells increased to a greater extent than those in culture with rIL-2 alone but cytotoxic activity did not augment, thus suggesting that this procedure would not afford sufficient clinical effects. On the other hand, a large number of LAK cells with high anti-tumor activities were efficiently induced from spleen cells of the patients by culture of rIL-2; hence clinical usefulness of these LAK cells is anticipated. In regional lymph node lymphocytes (RLNL) cultured with rIL-2, the cytotoxic activities were lower than in those induced in PBL, and a characteristic increase of CD8 + CD11 + suppressor T cells was observed after incubation with rIL-2. Nevertheless, an increase of CD4 + 4B4 + helper inducer T cells was also observed in RLNL after the culture with rIL-2. Furthermore, high cytotoxic activities were induced in RLNL in some cases in which metastasis to the regional lymph nodes was not detected. When gastric cancer patients were pretreated with biological response modifiers (BRM), especially with Lentinan, LAK cells from PBL showed higher NK and LAK activities as compared with those of patients without BRM pretreatment.

Adult↗
PubMed1992

Experimental metastasis of oncogene-transformed NIH 3T3 cells in chick embryo.

By means of a highly sensitive and quantitative assay for specific detection of metastasized tumor cells in chick embryonic organs using the polymerase chain reaction (PCR), we have examined the experimental metastatic ability of individual clones of NIH 3T3 cells, transformed with oncogenes: v-Ki-ras, v-Ha-ras, v-src, v-fos, and v-abl. Such a transformed clone had different metastatic abilities in different embryonic organs. Among them, two clones of NIH 3T3 cells transformed with ras-oncogenes (v-Ki-ras or v-Ha-ras) metastasized to liver and lungs of chick embryo, and grew there more rapidly than the other clones. The parental NIH 3T3 cells were detected as slight bands of PCR products after iv injection, indicating some cells were trapped in chick embryonic organs, but did not grow. These findings indicate that the transformed cells are able to invade the organ tissues and grow in embryonic chick organs, but non-metastatic cells such as the untransformed-NIH 3T3 cells are not able to grow in the secondary sites. These experiments clearly demonstrate the usefulness of this assay system to study genes involved in malignant transformation.

3T3 Cells↗
PubMed1992

Expression of genes encoding type IV collagen-degrading metalloproteinases and tissue inhibitors of metalloproteinases in various human tumor cells.

Uncontrolled expression of matrix metalloproteinases 2, 3 and 9 (MMP-2, -3 and -9) is believed to be a critical part of the invasive potential of tumor cells because of their ability to degrade type IV collagen, a major structural component of basement membranes. Availability of proteolytic activity in the vicinity of the cell surface is further affected by a local balance between the enzymes and their inhibitors produced by the cell. To determine how frequently deregulated expression of the MMPs and tissue inhibitors of metalloproteinases (TIMPs) is associated with tumor cells, 26 human tumor cell lines were examined by Northern blotting. Transcripts for MMP-2 and MMP-9 were more frequently expressed in mesenchymal tumor cells (9/9 for MMP-2 and 6/9 for MMP-9) than in epithelial tumor cells (4/17 for MMP-2 and 2/17 for MMP-9). Although expression of MMP-2 mRNA was clearly cell type-specific, MMP-9 mRNA expression in mesenchymal cells correlated well with the reported tumorigenicity of the cells. Enhanced expression of MMP-9 mRNA was also associated with the tumorigenic transformation of cells by an activated c-H-ras gene in human embryonic fibroblasts. Only 3 of the 26 tumor cells expressed MMP-3 mRNA, and 2 of the 3 were epithelial tumor cells which coordinately expressed MMP-9 and TIMP-1 mRNAs. TIMP-1 mRNA was almost undetectable in 50% of the tumor cells, but TIMP-2 mRNA was expressed in the majority of the cells. These findings provide comprehensive information about mRNA expression of the MMPs and TIMPs in tumor cells, the deregulation of which is thought to be an integral part of the invasive potential of tumor cells.

Cell Transformation, Neoplastic↗
PubMed1992

[Controversy between endoscopic and surgical treatment against early gastric and colorectal cancer].

Although endoscopic treatment against the patients with early cancer in gastrointestinal tract is an excellent method especially in high aged or poor risk patients, there still exists controversy about the indication for endoscopic treatment because of deeper invasion of the cancer or lymph node metastases. In order to clarify whether the patient has a possibility of nodal involvement or not, we made the clinicopathological analysis concerning 220 cases with early gastric cancers and 118 cases with colorectal cancers. Our retrospective analysis shows that endoscopic resection can be indicated for small polypoid cancer less than 10 mm in size, excluding IIa + IIc type. As to small depressed type, this procedure should be applied for IIc type which is well differentiated adenocarcinoma without ulcer formation (U1 (-)). Regarding early colorectal cancer there has been many discussion how to treat the patients with sm-cancer. Based on our analysis of 39 cases with sm-cancer, we led to the conclusion that the characteristics of sm-cancer with lymph node metastases are i) massive invasion into submucosal layer, ii) positive lymphatic permeation, or iii) "de novo" cancer. As a result, a decision of further surgery should be made even in small lesions less than 10 mm, taking the fact into consideration of the possibility of nodal involvement of sm-cancer.

Adult↗
PubMed1992

[Significance of CA72-4 as a follow up of recurrent gastric cancer--comparison with CEA and CA19-9].

We studied a significance of serum CA72-4 as a follow up of recurrent gastric cancer in 24 recurrent cases with gastric cancer performed combination assay of CEA, CA19-9 and CA72-4. Positive rate of CA72-4 was 58.3%, which was almost same as that of CEA. Lymph node metastasis and peritoneal dissemination were observed relatively high rate in positive cases with serum CA72-4. Comparison of an elevation time of CEA and CA72-4 in recurrent cases showed that CEA earlier than CA72-4 was 3 cases, CA72-4 earlier than CEA was 3 cases, and the others were about same. These results indicated that CA72-4 was a useful tumor marker as a follow up of recurrent gastric cancer.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

[Clinical significance of serum CA 125 values in patients with gastric cancers--especially correlation with peritonitis carcinomatosa].

A study of 387 patients with gastric cancers revealed elevation of CA 125 in sera of 7.2% of the patients. Patients with Borrmann 1 and 2 in gross type, poorly differentiated adenocarcinoma in histological type and stage 4 in stage grouping of gastric cancer, showed a higher positive rate than patients with the others. In patients with peritonitis carcinomatosa, positive rate of serum CA 125 was 42.9% of patients with synclonus metastasis, 72.2% with metaclonus metastasis. Elevation of serum CA 125 was observed earlier than detection by image diagnosis in almost all cases. These results indicate that CA 125 is an useful tumor marker for detection and follow up of patients with peritonitis carcinomatosa from gastric cancers.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Establishment of a human chorionic gonadotropin-producing human gastric carcinoma in nude mice.

A human chorionic gonadotropin (HCG)-producing gastric carcinoma was transplanted into BALB/c nu/nu nude mice. The original tumor tissue had been obtained by gastrectomy from a 55-year-old patient with gastric carcinoma. The tumor was transplanted serially in nude mice, and its doubling time was stable to approximately 12 days. A positive correlation was observed between serum HCG level and tumor weight. The serum HCG level of the mice and the histology of the tumor weight. The serum HCG level of the mice and the histology of the tumor, papillary adenocarcinoma with partial poorly differentiated adenocarcinoma, did not change on serial transfers. HCG was positively stained by an immunochemical technique only in the site of the poorly differentiated adenocarcinoma, while staining was negative in the site of the papillary adenocarcinoma, which constituted most of the tumor. These results indicate that this tumor in nude mice will be useful not only as a therapeutic experimental system but also for studying the potential malignancy of HCG-producing cancer cells.

Adenocarcinoma, Papillary↗
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

Anisakiasis of the colon: report of two cases with emphasis on the diagnostic and therapeutic value of colonoscopy.

Anisakiasis of the colon is a rare entity as compared with gastric anisakiasis, and its diagnosis is very difficult. We present here two cases--a 42-year-old woman and a 30-year-old woman--of anisakiasis of the colon treated by colonoscopic removal of the worm without surgery. The importance of colonoscopy for the diagnosis and treatment of this disease is briefly discussed.

Adult↗
PubMed1991

The changing direction of nystagmus in acute Menière's disease: pathophysiological implications.

The direction(s) and pathophysiologic basis of nystagmus during an acute attack of Menière's disease have been subject to much debate in the world literature. Clinical recordings from two patients whose nystagmus was captured near the very beginning of the acute vertiginous episode are presented. Previous clinical observations in Meniere's disease, experimental animal models concerned with initiation of peripheral nystagmus, and the phenomenon of recovery are discussed.

Acute Disease↗