[Analysis of cell nuclei and the quantity of chromosomal DNA by laser scanning cytometer (LSC)].
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Animals↗
Biomedical subjects
K Kawamoto
Publications and source records attributed to K Kawamoto.
Nerve growth factor prevents apoptosis of rat peritoneal mast cells through the trk proto-oncogene receptor.
We investigated the inhibitory activity of nerve growth factor (NGF) on apoptosis of rat peritoneal mast cells (PMCs) and compared it with that of recombinant stem cell factor (rSCF), which is a mast cell growth factor. When PMCs were incubated up to 72 hours in the presence of control medium, internucleosomal fragmentation of DNA indicating apoptosis was detected by agarose gel electrophoresis and flow cytometry. The aged PMCs showed morphological changes typical for apoptosis, such as chromatin condensation and loss of microvilli of the cell membrane. Addition of NGF or rSCF prevented development of the characteristic DNA fragmentation and decreased the proportion of apoptotic cells with low DNA content values in a dose-dependent manner. Polyclonal antibody to NGF completely abolished the inhibitory activity of NGF but not of rSCF. NGF-induced PMCs were in the G0/G1 phase of the cell cycle, but rSCF transited them from the G0/G1 phase to the S/G2M phase, suggesting that NGF, unlike rSCF, may have no proliferation activity to PMCs. By flow cytometric analysis with antibodies to NGF receptors p75LNGFR and p140trk, we defined that PMCs expressed p140trk but not p75LNGFR. Addition of herbimycin A or K-252a, tyrosine kinase inhibitors, to NGF resulted in blockage of the NGF-induced p140trk phosphorylation and restriction of the inhibitory activity of NGF on apoptosis of PMCs. These results indicated that NGF suppressed apoptosis of rat PMCs through the p140trk tyrosine phosphorylation and possessed no proliferative activity. Thus, NGF may act as a key factor to promote survival of connective tissue-type mast cells.
Animals↗
Glycosylation-dependent binding of pancreatic type I phospholipase A2 to its specific receptor.
Pancreatic group I phospholipase A2 (PLA2-I) elicits various biological responses via its specific receptor. The PLA2-I binding to its recombinant soluble receptor was considerably reduced after Peptide: N-glycosidase F treatment of the receptor. In cultured bovine smooth muscle cells, treatment with tunicamycin, a N-glycosylation inhibitor, resulted in a decrease in the number of PLA2-I receptor. In addition, the PLA2-I binding was blocked by the addition of a lectin, Wheat germ agglutinin. These results suggest an involvement of N-linked oligosaccharides of the PLA2-I receptor for its ligand recognition.
Animals↗
Correlation between tumor volume doubling time and histologic findings in gastric smooth muscle tumors: clinical implications of tumor volume doubling time.
To assess the clinical implications of the tumor volume doubling time of gastric smooth muscle tumors based on a comparison with the histologic findings, seven tumors (four leiomyomas and three leiomyosarcomas) were followed up by consecutive upper gastrointestinal studies between March 1985 and December 1993. The patients were four men and three women with an average age of 58 years (range: 50-71 years). The observation period ranged from 6 to 51 months, with an average of 35 months. All tumors were surgically resected and the histologic diagnosis was confirmed. The following microscopic features were evaluated: 1) mitotic rate, 2) nuclear atypia, and 3) cellularity. Each tumor was also evaluated for the presence or absence of necrosis, hemorrhage, and degeneration. The doubling time ranged from 5 to 27 months with a mean of 16 months. There was a strong negative correlation between the mitotic rate and the doubling time (r = -0.935, P = 0.0019). The doubling time was also significantly related to nuclear atypia, but the number of tumors studied was so small that its reliability was questionable. The doubling time was not related to any other histologic findings. This study shows that the doubling time is useful for estimating the malignant potential of gastric smooth muscle tumors, and that tumors with a doubling time of 16 months or less should be considered as malignant.
Aged↗
Analysis of the growth rate and cavernous sinus invasion of pituitary adenomas.
Pituitary adenomas generally are regarded as benign tumours, but a part of them can invade the cavernous sinus and recur. We examined 43 pituitary adenomas for the following factors: tumour volume, endocrinological function, cavernous sinus invasion, and growth rates examined by using anti-proliferating cell nuclear antigen (PCNA) and MIB1 (a novel anti-Ki-67) as markers. There was significant correlation between PCNA- and MIB1-positive cell rates and PCNA- and MIB1-positive cell rates were higher in the three cases with rapid regrowth than in the other cases. Staining was stronger and more distinct for MIB1 than for anti-PCNA; thus, MIB1-positive cells were easily distinguished by their intense immunoreactivity. MIB1 may be useful for detecting those rare cases with rapid regrowth even when initially regarded as benign tumours. Adenomas with cavernous sinus invasion were significantly larger than those demonstrating no invasion. However, no significant difference was found in the frequency of PCNA- or MIB1-positive cells between adenomas with and without cavernous sinus invasion. These findings suggest that cavernous sinus invasion and growth rate are independent biological factors. Therefore, cavernous sinus invasion may be due to chemical factors produced by the tumour itself rather than as a result of rapid tumour growth.
Adenoma↗
Natural history of minute sessile colonic adenomas based on radiographic findings. Is endoscopic removal of every colonic adenoma necessary?
PURPOSE: With the development of colonoscopy and double-contrast barium enema, detection of minute sessile colonic adenomas has increased. We evaluated progression of these lesions radiologically and attempted to clarify the natural history. METHODS: A total of 125 minute sessile adenomas (< or = 5 mm in size) with histologic confirmation were examined by double-contrast barium enema at an interval of more than one year. The average follow-up period was 24 (range, 12-36; standard deviation, 9.4) months. To allow for differences in magnification, adenomas increasing in size by 2 mm or more were defined as growing, and the other lesions were defined as unchanged. RESULTS: Eighty-six adenomas showed no interval change in size. Four adenomas decreased 1 mm in size, and 27 adenomas increased 1 mm in size. The remaining eight adenomas (6 percent) increased by 2 or 3 mm in size. None of the adenomas showed any morphologic changes. There was also no difference in degree of histologic atypia between growing and unchanged adenomas. None of the adenomas developed into carcinomas during the follow-up period. CONCLUSIONS: These data show that most minute sessile adenomas remain unchanged in size and morphology over the long term. Accordingly, these adenomas probably should be followed up radiologically or endoscopically to avoid excessive polypectomy.
Adenoma↗
Clinicopathologic growth factors of acoustic neuromas.
BACKGROUND Understanding the tumor growth rate is very important when considering strategies for the treatment of an acoustic neuroma, although the natural course of acoustic neuromas has not been reviewed in detail. METHODS The clinicopathologic features and the postoperative growth of tumors were evaluated in 32 patients with acoustic neuromas. This study was undertaken to assess the variability of the growth potential of cells within an acoustic tumor and to determine the relationships between the growth rate and the clinicopathologic characteristics of the patients with acoustic neuromas, including age at surgery, gender, tumor location and preoperative size, the duration of the symptoms, the presence of cystic regions, the presence of Antoni type A and B cells, the tumor cell density, tumor vascularity, mitotic rate, the presence of hyaline degeneration and hemosiderin deposition, nucleolar organizer regions (NORs), and the level of proliferating cell nuclear antigen (PCNA). RESULTS The growth patterns of the tumors were divided into three groups according to their growth rate: a regression group, a "no-growth" group (growth rates from 0-0.11 cm/year) and a progression group (growth rates from 0.19-1.72 cm/year). An additional operation was required in all patients whose growth rate was more than 0.38 cm/year. A statistical study on the factors associated with an increased growth rate showed that the three histopathologic factors most significantly associated with a postoperative growth rate were hyaline degeneration (p < 0.05), cell density (p < 0.005), and PCNA labeling index (p < 0.005). CONCLUSIONS These results strongly suggest that acoustic tumors can be subdivided into several groups, based upon different biologic activities and tumor growth rates.
Adult↗
Possible discrimination of Gitelman's syndrome from Bartter's syndrome by renal clearance study: report of two cases.
We observed two patients who had hypokalemic metabolic alkalosis as well as hypomagnesemia and hypocalciuria with elevated serum renin levels. In renal clearance studies in our patients using furosemide or thiazide, urine volume and chloride clearance (CCI) were increased after furosemide administration but not after thiazide administration. Furthermore, the distal fractional chloride reabsorption [CH2O/(CH2O + CCI)] was dramatically decreased by furosemide administration in our patients, whereas thiazide had little effect on it, suggesting the presence of a defect in the distal tubule rather than in the thick ascending loop of Henle. These findings are compatible with the concept of Gitelman's syndrome, a variant form of Bartter's syndrome.
Adult↗
Pancreatic-type phospholipase A2 activates prostaglandin E2 production in rat mesangial cells by receptor binding reaction.
Our earlier studies have shown that mammalian pancreatic group I phospholipase A2 (PLA2-I) has its specific receptor (PLA2 receptor) on a wide range of mammalian cells and that the receptor-binding capability of PLA2-I is a property of this molecule separable from its enzymatic activity. To clarify whether PLA2 activity is required for eliciting a biological response via the receptor or not, we examined the enzymatic activity of PLA2-I/PLA2 receptor complex and the inducibility of prostaglandin (PG) E2 production in rat mesangial cells by mutant PLA2s-I. Using a recombinant soluble PLA2 receptor, we first found that PLA2-I could not hydrolyze a phospholipid substrate when complexed with the receptor. In the next experiment using various mutant porcine PLA2s-I, we found that PGE2 production in rat mesangial cells could be induced by a mutant PLA2-I which retained the receptor-binding activity but had almost completely lost its enzymatic activity. These findings indicate that the enzyme action of PLA2-I is not required for a PLA2-I-induced biological response, i.e., the augmentation of PGE2 production in rat mesangial cells.
Animals↗
Elevated serum growth hormone accelerates gastric tumorigenesis in F344 rats after treatment with N-methyl-N-nitrosourea in their drinking water.
We examined the effects of growth hormone on tumorigenesis in F344 rats treated with N-methyl-N-nitrosourea (MNU). Four-week-old male F344 rats were exposed to 100 ppm MNU in their drinking water for 15 weeks. Thereafter Group II animals received 100 microCi/100 g body weight of 131I (radiothyroidectomy, Tx) injected i.p. and Group III rats were implanted with pituitary tumors (MtT) secreting growth hormone while Group I received no further treatment after MNU. Non-carcinogen control animals received MtT, Tx or no treatment. Animals were killed at 39 weeks after starting MNU administration. Gastric tumors were present in 13 of 31 (43%), 15 of 32 (47%) and 17 of 32 (53%) rats in Groups I to III, respectively. All tumors were of well-differentiated type. Spinal cord tumors appeared in 15 of 31 (47%) in Group I, 10 of 32 (32%) in Group II and 10 of 32 (32%) in Group III, most being malignant schwannomas. Thymic lymphomas also appeared in 10 of 31 (32%), 5 of 32 (16%) and 6 of 32 (19%) animals in Groups I to III, respectively. There were no significant differences among the groups. However, tumors in Group III developed significantly earlier than in Groups I or II. This was mainly due to gastric tumors, and cumulative incidence curves for spinal cord tumors or thymic lymphomas were similar in all groups. The results indicate that gastric tumors induced by MNU in F344 male rats are influenced by elevated levels of growth hormone.
Animals↗
In vivo effect of cabergoline, a dopamine agonist, on estrogen-induced rat pituitary tumors.
Cabergoline (CG) is a dopamine agonist that inhibits the secretion of prolactin (PRL) and growth hormone. In the present study, we evaluated the in vivo effect of CG on PRL secretion and the pituitary tumor induced by estrogen. Estrogen was administered by subcutaneous injection to 4-week-old Fischer 344 rats weekly for 10 weeks to induce tumors. On the last day of estrogen administration, doses of either CG or bromocriptine (BC), 0.6 mg/kg, were administered as a single oral route or chronically, given every third day. Sera and pituitary tumors were sampled on each treatment schedule. Serum levels of PRL were measured and the pituitary glands were weighed. Immunohistological evaluation was performed by optical and electron microscopy. A single dose of CG significantly inhibited the serum levels of PRL for 6 days. Following a single dose of BC, the PRL level was significantly inhibited only at 6 hours' postadministration. The continued oral administration of CG significantly reduced both the serum PRL level and the weight of the pituitary during 15 to 60 days of treatment as compared with BC. Morphologic studies revealed that CG reduced the size of the cells and of the granules, and increased the number of granules per unit area of the cytoplasm. These findings suggest that CG inhibits the maturation of PRL secretory granules and the secretion of PRL more than its synthesis. Thus, CG induced a prolonged lowering of PRL and had a good antitumor effect on rat pituitary tumors induced by estrogen.
Animals↗
Characteristics of prolactin secretion in normal and estrogen-treated pituitaries of rats at the single cell level: analysis by reverse hemolytic plaque assay.
We studied PRL release from individual pituitary cells in normal and estrogen (E2)-treated female Fischer 344 rats by means of a reverse hemolytic plaque assay. In this assay, the area of the hemolytic plaque around a pituitary cell is proportional to the amount of hormone secreted from the cell. Multimodal distribution of the plaque area was observed in normal pituitary cells, and was unchanged in the course of aging. In E2-treated pituitary cells, bimodal distribution was found. The heterogeneity of the distribution pattern (functional heterogeneity) and PRL secretion from a single pituitary cell decreased in association with the length of E2 treatment. The mean plaque area for the E2-treated pituitary cells was smaller than that for the normal pituitary cells. These results suggest that in E2-treated pituitary cells, the functional heterogeneity and PRL release from a single cell decrease as tumorigenesis progresses.
Animals↗
Effect of cabergoline, a dopamine agonist, on estrogen-induced rat pituitary tumors: in vitro culture studies.
Cabergoline (CG) is a dopamine agonist that inhibits secretion of prolactin (PRL) and growth hormone. The purpose of this study was to investigate the PRL-lowering effect and antitumor effect of CG on estradiol-induced rat pituitary tumors in vitro and to elucidate these mechanisms. We compared the effects of CG with those of bromocriptine (BC) in terms of the inhibition of hormone secretion as well as antitumor effects on rat pituitary tumors. Primary cultures of dissociated pituitary tumor cells were used in these studies. A significant inhibition of prolactin (PRL) secretion was observed for both drugs within 12 h after treatment, and the inhibitory effects of CG and BC were antagonized by sulpiride or haloperidol. Inhibitory effect on PRL secretion after 12-h BC or CG pretreatment was more pronounced with CG than BC treatment at all time points. PRL secretion in group pretreated with CG was significantly suppressed at 72 h when compared to that of vehicle. Inhibition of de novo PRL synthesis was better demonstrated in the CG group. These findings suggest that CG has a higher affinity for the D2 receptor of pituitary cells as compared to BC and may preferentially inhibit PRL secretion rather than PRL production. An antitumor effect of CG has been confirmed at a lower dosage than that of BC.
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Secretion of growth hormone (GH)-releasing hormone by GH-producing pituitary adenoma assessed by cell immunoblot analysis.
To detect growth hormone-releasing hormone (GHRH) secreted by monodispersed human GH-producing pituitary adenoma cells, the cell immunoblot assay was performed. GHRH-secreting cells were observed in 3 cases of GH-producing pituitary adenomas. The incidence of GHRH-secreting cells in the total cell populations was 0.24-3.42%. By contrast, no GHRH-secreting cells were observed in 2 cases of clinically nonfunctioning pituitary adenomas. The findings obtained by immunohistochemical studies for adenohypophysial hormones and for nuclear antigens of proliferative activity revealed that the incidence of GHRH-secreting cells is more related to the frequency of GH cells than to the proliferative activity in GH-producing pituitary adenomas.
Adenoma↗
Assessment of production of endothelium-derived relaxing factor by cultured porcine cerebral microvessel endothelial cells.
To establish an experimental system to assess the production of endothelium-derived relaxing factor (EDRF) by cultured porcine cerebral microvessel endothelial cells (PCMEC), the effect of PCMEC on thrombin-induced platelet aggregation was studied. For the platelet aggregation cuvettes lined with PCMEC were used. The cuvettes were prepared by seeding PCMEC in gelatin-coated cuvettes at a cell density of 2 x 10(5) cells/ml and culturing for 48 hours. Thrombin-induced platelet aggregation was markedly inhibited in the presence of PCMEC. Indomethacin reduced the PCMEC-dependent anti-platelet aggregatory effect. This PCMEC-dependent anti-platelet aggregatory effect was increased by the addition of bradykinin which stimulates the production of EDRF. These findings suggest that this simple experimental system is useful in assessing the production of EDRF by PCMEC and in examining the effects of various chemicals (or agents) on EDRF production.
Animals↗
[A case of spinal astrocytoma presenting spinal transverse sign due to hematomyelia].
An unusual case of cervical astrocytoma due to hematomyelia was reported. A 68-year-old man was admitted to our institute because of sudden onset of paraplegia and urinary and bowel disturbance. CT and plain X ray on admission showed no abnormal findings, but emergency MRI revealed a high signal intensity area in Th 8-9 level on T1 weighted image. Preoperative diagnosis was idiopathic hematomyelia and emergency laminectomy was performed. After the dural incision from Th 8-10, the intramedullary hematoma was totally removed, but at the cephalic portion within the hematoma cavity an abnormal tumorous tissue was detected. It was noticed with the bleeding sauce of hematomyelia, and it, too, was totally removed. The microscopic finding concerning the surgical specimen was fibrillary astrocytoma (grade 2), and its vascular component was relatively rich.
Aged↗
Mechanisms of eosinophilia in mice infested with larval Haemaphysalis longicornis ticks.
Infestation of larval Haemaphysalis longicornis ticks induced a threefold increase of eosinophils in the peripheral blood of normal WBB6F1- +/+ mice 2 days after tick infestation. In genetically mast cell-deficient WBB6F1- W/Wv mice, a threefold increase of blood eosinophils was observed 6 days after the tick infestation. However, marked infiltration of eosinophils was detected in the tick infestation sites of the WBB6F1- +/+ mice but not the WBB6F1- W/Wv mice. When the mast cell deficiency of WBB6F1- W/Wv mice had been rescued locally by intradermal injections of WBB6F1- +/+ mouse-derived cultured mast cells, a rapid increase of blood eosinophils and tissue infiltration of eosinophils were revealed following tick infestation. The intravenous (i.v.) injection of immune spleen or lymph node cells obtained from WBB6F1- +/+ mice 10 days after tick infestation led to significant eosinophilia in naive recipient mice. Treatment with anti-Thy-1.2 or anti-CD4 monoclonal antibody (mAb) and complement (C) completely abolished the eosinophilia; the early response (2 days after tick challenge) is dependent on mast cells at the feeding site, and the late response (6 days after tick challenge) is dependent on T lymphocytes. Since amplified interleukin-5 (IL-5) cDNA was detectable in the spleen cells 4 days after tick infestation, the late response might be mediated by IL-5. The infiltration of eosinophils at the feeding site of skin appeared to be dependent on mast cells.
Animals↗
Cytogenical analysis of brain tumors by FISH (fluorescence in situ hybridization) and FCM (flow cytometry).
In the present study, an analysis was made of chromosomal aberrations in brain tumors using the fluorescence in situ hybridization (FISH) technique. At the same time DNA histograms were obtained by flow cytometry (FCM) to make a comparative study of histological malignancy and prognosis. The subjects included 30 gliomas (7 of astrocytoma grade II, 15 of anaplastic astrocytoma (grade III), 8 of glioblastoma (grade IV)) and 26 meningiomas. In the study of FISH, DNA probes for chromosomes No. 7, 9, 10, and 17, were used to cause a reaction with chromosome No. 22 added for meningiomas. In the study with FCM, DNA index from DNA histogram was calculated using lymphocytes as the internal standard. In gliomas as a whole, chromosomes No. 7 and 17 showed high values, whereas, chromosomes No. 9 and 10 low values. Analysis by the grades of glioma showed that compared with gliomas of other grades, grade IV gliomas were higher for chromosome No. 17 and lower for chromosome No. 10. In meningiomas, while many cases showed a low value for chromosome No. 22, most cases of recurrent and atypical meningiomas showed a high value for chromosome No. 17. In gliomas, DNA index showed a correlation with the grade, and a positive correlation particularly with chromosome No. 17 in FISH. Recurrent and atypical meningiomas had a high DNA index.
Adolescent↗