Biomedical subjects

H Kawamata

Publications and source records attributed to H Kawamata.

At least 91 records · Page 5Linked to original sources

PubMed1994

[Three-dimensional imaging of portal and hepatic veins using helical CT with intravenous injection of contrast medium].

The authors developed a simple new method for obtaining three-dimensional helical CT images that simultaneously depict both the portal and hepatic veins. One hundred ml of contrast medium was injected intravenously, and helical CT was carried out. Three-dimensional venous images were successfully displayed with rotational movement on the CRT monitor. The new method provided high-quality images in which the anatomical relationship between the portal and hepatic venous systems could be clearly visualized. This information was useful in helping angiographers to successfully perform transjugular intrahepatic portosystemic shunt and will be of great value for the presurgical planning of hepatic resection.

Adult↗

PubMed1994

Persistence of carcinogen-altered cell population in rat urothelium which can be promoted to tumors by chronic inflammatory stimulus.

Chronic inflammation of the urinary tract is a significant risk factor for the development of urinary bladder cancer in man. Previously we have shown that acute and chronic inflammation induced by repeated intravesical instillation of killed Escherichia coli (KEC) strikingly enhanced N-methyl-N-nitrosourea (MNU)-initiated bladder carcinogenesis in our heterotopically transplanted rat urinary bladder model. We conducted the present study to determine whether delayed onset of KEC treatment can still enhance carcinogenesis of the MNU-initiated urothelium and whether continuous KEC treatment is necessary for the development of tumors. After the initiation of carcinogenesis in heterotopically transplanted bladders by the instillation of a single dose (0.25 mg) of MNU, animals were divided into several groups, for which weekly KEC treatment (5 x 10(8) cells suspended in 0.5 ml of phosphate-buffered 2.1% NaCl solution) was begun 1, 5, and 18 weeks later and continued until termination of the experiment at 31 weeks. In addition, animals received 4-week KEC treatment, which was started 1 or 5 weeks after MNU administration. Treatment with KEC alone or MNU alone induced few tumors. Maximal tumor development was demonstrated in the group receiving KEC treatment continuously throughout the experimental period. Delaying the onset of continuous KEC treatment by 4 weeks resulted in a significant decrease in the number of tumors (P = 0.006). However, a substantial number of tumors were induced even when KEC treatment was delayed as many as 18 weeks, as compared to tumor development in the group receiving MNU only (P = 0.007). The tumor volume (size) was not different between continuous and short-term KEC treatment groups. We conclude that (a) although a large number of cells undergo promutagenic DNA damage by a single dose of MNU, the amounts are reduced quickly during the subsequent 4 weeks; but that (b) a substantial number of genetically altered cells remain for a long time and can be promoted to tumors when stimulated by a chronic inflammatory stimulus; and that (c) the duration of KEC treatment determines the number, but not the volume, of tumors.

Animals↗

PubMed1994

In vitro and in vivo acceleration of the neoplastic phenotype of a low-tumorigenicity rat bladder carcinoma cell line by transfected transforming growth factor-alpha.

We conducted an experiment to determine whether expression of transforming growth factor-alpha (TGF-alpha) enhances tumorigenicity in a low-tumorigenicity rat bladder carcinoma cell line and whether it is sufficient to induce a tumorigenic phenotype in a nontumorigenic rat bladder cell line. D44c cells (which are nontumorigenic) were derived from a minute nodule from a bladder treated with N-methyl-N-nitrosourea (MNU); G1-200 cl-17 cells (which have low tumorigenicity) were isolated from D44c cells exposed to MNU in vitro. Neither cell line expressed TGF-alpha mRNA. The cells were cotransfected with pSV2neo and pSR alpha-rTGF-alpha. The latter plasmid contains the rat TGF-alpha cDNA under the transcriptional control of the SR alpha promoter. In the low-tumorigenicity G1-200 cl-17 cells, the expression of TGF-alpha mRNA and the subsequent synthesis of TGF-alpha protein activated epidermal growth factor receptors (EGFRs) and markedly enhanced tumorigenicity in nude mice (i.e., shortened the latency period before tumor appearance, accelerated the rate of growth, and increased the size of the tumors) as well as anchorage-independent growth in vitro. In nontumorigenic D44c cells, however, transfected TGF-alpha did not induce either anchorage-independent growth or tumorigenicity in nude mice, in spite of overexpression of EGFR mRNA and the constitutive expression of c-jun and junB mRNA. These results suggest that the increased signal transduction mediated by TGF-alpha enhanced tumorigenicity in a cell that was already tumorigenic but was not sufficient to induce tumorigenicity in a nontumorigenic cell.

Animals↗

PubMed1994

Cytotoxic effect of a fusion protein from transforming growth factor alpha and Pseudomonas exotoxin on rat and human bladder carcinoma cells in vitro.

A protein formed by fusion of transforming growth factor alpha with Pseudomonas exotoxin (TGF alpha-PE40) has been shown to have the ability to kill or inhibit the growth of several carcinoma cell lines. This study was designed to evaluate the in vitro cytotoxic effects of TGF alpha-PE40 on rat and human bladder carcinoma cell lines with different biological potential, and normal rat urothelial cells. The rat cell lines used were D44c, LMC19, and MYU3L, which were established in our laboratory. Human cell lines used were RT4, T24, and 253J. As a normal control, we used the first-passage culture of normal rat bladder urothelium (RU-P1). We examined the number and affinity of epidermal growth factor receptors (EGFR) in these cells, the ability of TGF alpha-PE40 to bind EGFR, and the cytotoxic effect of TGF alpha-PE40 and PE40. Rat cell lines, D44c, LMC19, and MYU3L (EGFR = 4.9 x 10(3)-11.4 x 10(3)/cell) had ED50 values (the concentration of TGF alpha-PE40 needed to reduce the viable cell population by 50%) of 180 pM, 540 pM and 6000 pM respectively; for cI (the concentration required to achieve complete inhibition of growth under continuous serum stimulation) TGF alpha-PE40 concentrations of 10(4) pM, 10(4) pM and higher than 10(4) pM respectively were required. Human cell lines, RT4, T24, and 253J (EGFR = 32 x 10(3)-126 x 10(3)/cell) had ED50 values of 20 pM, 66 pM, and 330 pM respectively and T24 showed cI values of 10(3) pM. RU-P1 (EGFR = 92.6 x 10(3)/cell) had the highest ED50 value of 8000 pM. These data indicate that the susceptibility to TGF alpha-PE40 does not always depend on the number of EGFR, that cells having a relatively small number of EGFR respond well to TGF alpha-PE40, and that normal urothelial cells are more resistant to TGF alpha-PE40 than are cancer cells. The differential effect of TGF alpha-PE40 on normal and neoplastic cells provides a rational basis for its use in vivo to control tumor growth.

ADP Ribose Transferases↗

PubMed1994

Human chorionic gonadotropin beta-subunit synthesis by undifferentiated urothelial carcinoma with syncytiotrophoblastic differentiation.

An undifferentiated deeply invasive ureteral carcinoma with syncytiotrophoblastic differentiation was analyzed for the synthesis of human chorionic gonadotropin beta-subunit by immunohistochemistry and Northern blot analysis. Human chorionic gonadotropin beta-subunit was localized immunohistochemically to syncytiotrophoblastic cells and scattered mononuclear tumor cells. Human chorionic gonadotropin beta-subunit gene was expressed at a high level by Northern blot analysis. To our knowledge, this is the first report demonstrating the synthesis of human chorionic gonadotropin beta-subunit at the transcriptional level in a urothelial carcinoma.

Aged↗

PubMed1993

Differential expression of keratin 5 gene in non-tumorigenic and tumorigenic rat bladder cell lines.

In this study, we attempted to find a gene or genes which were differentially expressed between a non-tumorigenic rat bladder cell line and a highly tumorigenic/metastatic bladder carcinoma cell line that was derived from the former after treatment in vitro with N-methyl-N-nitrosourea. We cloned a rat keratin 5 cDNA by a differential hybridization technique and found that all of the non-tumorigenic cells (7/7) and normal bladder tissue expressed keratin 5, but most of the tumorigenic cells (8/10) did not express keratin 5. Furthermore, in a spontaneously transformed cell line, keratin 5 expression was lost during the transformation process. These results suggest that loss of keratin 5 expression is closely associated with acquisition of a tumorigenic phenotype by rat bladder non-tumorigenic cells.

Animals↗

PubMed1993

Effect of epidermal growth factor and transforming growth factor beta 1 on growth and invasive potentials of newly established rat bladder carcinoma cell lines.

We established 5 rat bladder cell lines (MYU3L, MYU4, MYU6s, MYKU1L and MYP3). EGF stimulated DNA synthesis of all the cells in monolayer culture, regardless of the number of EGF receptors. In soft agar, only MYU3L formed colonies, and EGF enhanced their growth. However, EGF did not induce the other cells to grow in soft agar. In contrast, TGF-beta 1 inhibited the growth of the cells, but a tumorigenic cell and the cells which were established from large in vivo tumors were more resistant than the others to TGF-beta 1. We tested the effect of growth factors on the invasive potential of MYP3 cells (non-tumorigenic), MYU3L cells (tumorigenic/highly invasive but not metastatic) from newly established cell lines, and another metastatic cell line, LMC19. MYP3 expressed only a trace amount of 92-kDa gelatinase (MMP-9), whereas MYU3L expressed interstitial collagenase (MMP-1) and MMP-9, and LMC19 expressed 72-kDa gelatinase (MMP-2) and MMP-9. The release of MMP-2 in LMC19 was stimulated by TGF-beta 1, but EGF had no effect on the release of any MMPs in either type of cells. These observations suggest that EGF acted as a mitogen on all the cells tested, but did not enhance the malignant phenotype. Further, the loss of responsiveness to the suppressive effect of TGF-beta 1 may be an important step toward a malignant phenotype. Some of malignant tumors may utilize TGF-beta 1 for enhancing their invasive and metastatic potential.

Animals↗

PubMed1993

Enhancement of rat urinary bladder tumorigenesis by lipopolysaccharide-induced inflammation.

Chronic inflammation of the urinary tract is a significant risk factor for the development of urinary bladder cancer in humans. We previously demonstrated that weekly treatment with killed Escherichia coli enhanced rat urinary bladder tumorigenesis initiated by the carcinogen N-methyl-N-nitrosourea. We conducted the present study to determine whether lipopolysaccharide (LPS), a major cell wall component of E. coli, had a tumor-enhancing effect. LPS was instilled twice a week at three doses (100, 1.0, and 0.01 microgram/ml) into heterotopically transplanted rat urinary bladders which were treated with a single low dose (0.25 mg) of N-methyl-N-nitrosourea or vehicle. Rats treated with 100 micrograms/ml of LPS showed a significant increase in the incidence and number of tumors in the bladders pretreated with N-methyl-N-nitrosourea. Treatment with LPS alone did not induce tumors. The enhancing effects were associated with a marked increase in the numbers of polymorphonuclear leukocytes and an increase in the H2O2 concentration in the bladder lumen. Oxidative stress by reactive oxygen intermediates and a proliferative response of the carcinogen-exposed urothelium to the inflammatory stimulation appeared to play a significant role in tumor enhancement by LPS.

Animals↗

PubMed1993

Immunohistochemical localization of transforming growth factor alpha in the major salivary glands of male and female rats.

The three major salivary glands of normal male and female Fischer 344 rats of different ages were examined for the localization of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) by immunohistochemical staining. EGF was demonstrated only in the granulated convoluted tubule (GCT) cells of the submandibular gland, the results confirming the previous reports, and most abundantly in adult males and pregnant females. TGF alpha stain was localized in all three glands and was found throughout the entire duct system, excluding acinar cells. The myoepithelial cells of the sublingual gland were also reactive with the TGF alpha antibody. The specificity of the staining was confirmed by negative staining reaction with the absorbed antibody and by radio-immunoassay and Western blot methods. This is the first report describing the presence of TGF alpha in the rat salivary glands.

Animals↗

PubMed1993

Immunohistochemical localization of epidermal growth factor and transforming growth factor alpha in the male rat accessory sex organs.

We examined the presence of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) in the prostate (ventral, lateral, dorsal lobes), coagulating gland and seminal vesicle of Fisher 344 adult male rats by immunohistochemical and radioimmunoassay methods. Immunohistochemically demonstrable EGF was localized in the luminal secretion only of the dorsal lobe of the prostate. Reactive TGF alpha was localized in the lateral lobe (100% of epithelial cells), dorsal lobe (about 40% of the epithelial cells) and seminal vesicle (100% of epithelial cells), but not in the coagulating gland or ventral lobe of the prostate. Radioimmunoassay also demonstrated a measurable amount of TGF alpha in the lateral lobe (194 pg./gm. wet weight) and seminal vesicle (74 pg./gm.). Assayable EGF was demonstrated at much higher levels in all prostate lobes (ranging from 1.2 micrograms./gm. wet weight in the ventral lobe to 26.4 micrograms./gm. in the dorsal lobe) and wet weight in the ventral lobe to 26.4 micrograms./gm. in the dorsal lobe) and the seminal vesicle (0.9 micrograms./gm.). This is the first report describing the presence of immunoreactive TGF alpha and EGF in the male accessory sex organs.

Animals↗

PubMed1993

A new in vivo model for studying invasion and metastasis of rat and human bladder carcinomas.

The biological potential of tumor cells is best evaluated at the organ site orthotopic to the tumor cells. Recent studies have documented site-specific differences in the potential of tumor cell growth. However, orthotopic implantation of bladder cancer cells into bladders of nude mice only resulted in a low tumor yield. We have developed a new model that consists of a rat bladder transplanted into the retroperitoneal space and connected to a reservoir s.c. placed in a nude mouse. Rat malignant bladder cancer cells (MYU3L and LMC19) transfected with the human growth hormone (hGH) gene as a biomarker were introduced into the transplanted bladder by percutaneous puncture of the attached reservoir. Successful uptake was indicated by a progressive rise in the hGH level in the bladder aspirate. When examined at 6-16 weeks post transplantation, all mice that had received MYU3L (n = 6) or LMC19 (n = 6) cells were found to have invasive carcinomas. MYU3L was highly invasive, forming multiple peritoneal implants, but was not metastatic. LMC19 was deeply invasive and metastasized to the retroperitoneal and subclavian lymph nodes and the lungs (4/6). Of two human bladder cancer cell lines (RT4 and T24) tested, RT4 formed multiple minute papillary tumors in five of six bladders, two of which were minimally invasive to the muscle layer. T24 cells formed only one to two small tumors in three of six bladders, and these were confined to the lamina propria. This system appears promising for studies of the mechanism of tumor invasion and metastasis and for evaluation of antineoplastic agents.

Animals↗

PubMed1992

Effect of dibutyryl cyclic adenosine 3',5'-monophosphate on morphological features and biological markers of human salivary myoepithelial cell line in culture.

We have found the emergence of myoepithelial cells (HSG-AZA1) in neoplastic human salivary intercalated duct cell line HSG in culture after treatment with 5-azacytidine. When HSG-ZAZ1 cells were cultured in the presence of N6,O2-dibutyryl cyclic adenosine 3',5'-monophosphate (dB-cAMP), they formed long cytoplasmic processes which were densely packed with ample microfibrils in addition to microtubule bundles. The expression of neuron-specific enolase, synaptophysin, and catecholamine as well as neurofilaments in the treated HSG-AZA1 cells was found by the immunofluorescence staining technique, immunoblotting, immunoelectron microscopy, or catecholamine fluorescence. Both the anchorage-independent and anchorage-dependent growths of HSG-AZA1 cells were suppressed in the presence of dB-cAMP. After the removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype and growth rate of the untreated cells. These findings indicate that reversible differentiation into the neuron-like cells of HSG-AZA1 cells occurs in growth medium containing dB-cAMP.

Analysis of Variance↗

PubMed1992

Effect of epidermal growth factor/transforming growth factor alpha and transforming growth factor beta 1 on growth in vitro of rat urinary bladder carcinoma cells.

The response to growth factor stimulation was evaluated in clonally derived rat bladder carcinoma cell lines, ranging from nontumorigenic to tumorigenic and metastatic, in athymic nude mice. In the nontumorigenic cell line D44c, epidermal growth factor (EGF)/transforming growth factor (TGF) alpha weakly stimulated anchorage-dependent, but not -independent, growth. In tumorigenic/nonmetastatic cells (G1-200 Cl-17), EGF/TGF-alpha stimulated markedly anchorage-independent, but marginally anchorage-dependent growth, whereas TGF-beta 1 inhibited anchorage-independent growth and DNA synthesis. In the highly tumorigenic/metastatic cell line LMC19, EGF/TGF-alpha stimulated anchorage-dependent growth weakly and anchorage-independent growth strongly. In these cells, TGF-beta 1 did not inhibit anchorage-independent growth and DNA synthesis but increased the size of colonies irrespective of the presence of EGF, and some cells were scattered around colonies in soft agar. None of the cell lines showed evidence of TGF-alpha-specific mRNA transcription. Expression of TGF-beta 1 mRNA increased in parallel to the biological aggressiveness of the cell lines. Highly tumorigenic and metastatic cells also demonstrated gelatinase activity involving 72 kilodalton and 92 kilodalton types. Our data suggest that the growth-stimulatory effect of EGF/TGF-alpha in soft agar may be limited to cells that are already tumorigenic and that EGF/TGF-alpha is not effective in making nontumorigenic cells become tumorigenic (or in making nontumorigenic cells grow in soft agar).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

[Value of "additional arterial embolization" to bilateral internal iliac TAE in patients with severe pelvic fractures].

Transcatheter arterial embolization (TAE) of the bilateral internal iliac arteries has been shown to be of great value in controlling retroperitoneal massive hemorrhage associated with pelvic fractures. It has recently been reported, however, that TAE of only the bilateral internal iliac arteries sometimes fails to stabilize the patient's hemodynamics. The purpose of the present study was to evaluate "additional arterial embolization" to the bilateral internal iliac TAE in hemodynamically unstable cases. Sixty-eight patients who underwent emergency TAE following severe pelvic fractures were reviewed. Additional arterial embolization of the lumbar arteries in four patients, middle sacral arteries in two and inferior epigastric artery in one was carried out following bilateral internal iliac TAE. The damage to these arteries was associated with fractures of the lumbar costal process, sacrum, pubis, etc. The patients were in stable condition after the procedure, and no significant complication was experienced. When fractures and dislocations of the above-mentioned bones are seen on plain X-ray films and arterial bleeding is identified by angiography, additional embolization of the arteries should be performed immediately.

Adult↗

PubMed1990

[Clinical assessment of rotational digital angiography for the diagnosis of aortic dissection].

Rotational digital angiography was performed in five patients with aortic dissection. Intimal tears, intimal flap and involvement of major branches were clearly demonstrated in two patients with opacified false lumen. Ulcer-like projections were also identified in three patients with thrombosed false lumen. The device has, therefore, been found to be of great value in diagnosing aortic dissection particularly for the detection of intimal tear sites and ulcer-like projections.

Aortic Dissection↗

PubMed1990

Induction of bone formation in an adenoid cystic carcinoma of the maxillary sinus by adoptive immunotherapy involving intra-arterial injection of lymphokine-activated killer cells and recombinant interleukin-2 in combination with radiotherapy.

A patient with an adenoid cystic carcinoma of the maxillary sinus was treated by adoptive immunotherapy involving intra-arterial injection of lymphokine-activated killer cells (a total number of 7 x 10(7) cells) and recombinant interleukin-2 (a total dose of 2.75 x 10(7) units) in combination with radiotherapy (60Co; total irradiation dose of 5,000 rads). Consequently, it was found that bone formation was induced in the treated tumor, which was then replaced completely by lamellar bone tissue with myxomatous stroma. This finding indicates that the tumor cells composing certain adenoid cystic carcinoma can be converted into normal-appearing, bone-forming cells by current therapy and this differentiation phenomenon leads to cure of the tumor.

Biopsy↗

PubMed1989

Induction of cells with a chondrocyte-like phenotype by treatment with 1 alpha,25-dihydroxyvitamin D3 in a human salivary acinar cell line.

A clonal cell with an acinar cell phenotype, which was induced by 5-azacytidine treatment of a neoplastic human salivary intercalated duct cell line, was cultivated in the presence of 1 alpha,25-dihydroxyvitamin D3. Morphological changes occurred; large cells that were polygonal or round in shape and had numerous vacuoles in their cytoplasm appeared in the treated cells, whereas the same concentration of 1 alpha,25-dihydroxyvitamin D3 did not affect the morphology of the parental cells. Major alterations, such as expression of type II collagen, alpha and beta chains of S-100 protein, and sulfated proteoglycans, were observed in these cells with a phenotype similar to chondrocytes. After the removal of 1 alpha,25-dihydroxyvitamin D3 from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that the reversible differentiation into chondrocyte-like cells of a human salivary acinar cell line occurs in growth medium containing 1 alpha,25-dihydroxyvitamin D3.

Calcitriol↗

PubMed1988

Effects of retinoic acid on morphological features and biological markers of a neoplastic human salivary intercalated duct cell line in culture.

Retinoic acid has marked effects on the growth, morphological features, and biological markers of a neoplastic human salivary intercalated duct cell clone in culture, whereas the cell clone was not affected by other retinoids such as retinol and retinal. A cell clone with ultrastructure and biological markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of retinoic acid. Major alterations, such as expression of tonofilaments, Mr 68,000 cytokeratin, and involucrin, were observed in those cells with a phenotype similar to that of keratinizing squamous cells. In addition, the coexpression of Mr 68,000 cytokeratin and carcinoembryonic antigen in these altered cells was found. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of retinoic acid. After the removal of retinoic acid from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the keratinizing squamous cells of a neoplastic human salivary intercalated duct cell clone occurs in growth medium containing retinoic acid.

Adenocarcinoma↗