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Biomedical subjects

F Abe

Publications and source records attributed to F Abe.

At least 73 records · Page 4Linked to original sources
PubMed1996

Effects of sex steroids and growth factors on migration and invasion of endometrial adenocarcinoma SNG-M cells in vitro.

Biological effects of sex steroids (estradiol-17beta, E2; progesterone, P; medroxyprogesterone acetate, MPA; Danazol, DZ) and growth factors (epidermal growth factor, EGF; transforming growth factor, TGF-alpha,beta) on migration and invasion of endometrial adenocarcinoma SNG-M cells were investigated by haptotactic migration and haptoinvasion assay. The enzymatic degradation of the extracellular matrix by tumor cells was also examined. Tumor cell migration along a gradient of substratum-bound fibronectin was inhibited by 0.1-10 microM MPA and DZ, but promoted by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. E2, P and TGF-beta did not have any effect on the motility of tumor cells. These effects were also confirmed by wound assay. The invasive activity of SNG-M cells into reconstituted basement membrane (Matrigel) was inhibited by the presence of 0.1-10 microM MPA and DZ, but promoted by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. E2, P and TGF-beta did not have any effect on tumor cell invasion. The zymography of tumor-conditioned medium showed that the treatment of SNG-M cells with EGF and TGF-alpha resulted in the increase of the 68, 72 and 92 kDa type IV collagenases (matrix metalloproteinase, MMP-2 and 9). Sex steroids and TGF-beta did not have significant effects on MMP-2 and 9. Stromelysin (MMP-3), also secreted by SNG-M cells, was not affected by sex steroids and growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion process of endometrial adenocarcinoma cells, which may partly be associated with the induction of type IV collagenase secretion by tumor cells. The inhibitory effects of MPA and DZ on tumor cell invasion may depend at least partly on their inhibitory action on the motility of tumor cells.

Adenocarcinoma↗
PubMed1996

Effects of cyclopiazonic acid and ryanodine on cytosolic calcium and contraction in vascular smooth muscle.

1. In smooth muscle, both Ca2+ release from the sarcoplasmic reticulum (SR) and Ca2+ influx across the plasma membrane are responsible for the increase in the cytosolic Ca2+ level ([Ca2+]i). To understand further the role of SR on smooth muscle contraction, the effects of an inhibitor of the SR Ca2+ pump, cyclopiazonic acid (CPA 10 microM), an inhibitor of the Ca(2+) -induced Ca2+ release, ryanodine, (10 microM), and an activator of the Ca(2+) -induced Ca2+ release, caffeine (20 mM), on [Ca2+]i and contractile force were examined in the ferret portal vein loaded with a photoprotein, aequorin. 2. CPA induced a small increase in the aequorin signal reaching a maximum at 7 min. Several minutes after the increase in the aequorin signal, muscle tension increased reaching a maximum at 21.5 min. In contrast, ryanodine changed neither the aequorin signal nor contraction. In the presence of ryanodine, caffeine induced a sustained increase in the aequorin signal and transient contraction. After washing ryanodine and caffeine, the aequorin signal and muscle tone returned to their respective control levels. After treatment with ryanodine and caffeine, the second addition of caffeine was almost ineffective whereas CPA still increased the aequorin signal and muscle tension. 3. In the presence of external Ca2+, noradrenaline (NA, 10 microM) induced a transient increase followed by a sustained increase in the aequorin signal and sustained contraction. In contrast, KCl (70 mM) induced sustained increases in the aequorin signal and sustained contraction. In Ca(2+) -free solution, NA induced a small transient increase in the aequorin signal and a small transient contraction. These changes were inhibited in the presence of CPA or on pretreatment of the muscle with ryanodine and caffeine. These results suggest that CPA or ryanodine and caffeine depleted Ca2+ in SR. High K+ was ineffective in the absence of external Ca2+. 4. In the presence of external Ca2+ and CPA, NA and high K+ induced larger aequorin signals than in the absence of CPA, whereas the magnitude and shape of the contractions did not change. In contrast, pretreatment with ryanodine and caffeine did not have such an effect. In the muscle pretreated with ryanodine and caffeine, CPA changed the responses to high K+ and NA in a similar manner to that in the muscle without the pretreatment with ryanodine and caffeine. 5. Dissociation of contraction from [Ca2+]i as measured with aequorin suggests that NA and high K+ increase Ca2+ in two compartments: a compartment containing contractile elements (contractile compartment) and another compartment unrelated to contractile elements (non-contractile compartment). Because CPA augmented the stimulant-induced increase in aequorin signal without changing contraction, the non-contractile compartment may be located near the SR and the CPA-sensitive SR Ca2+ pump may regulate the Ca2+ level in this compartment. However, because CPA changed neither the magnitude nor shape of the contractions in the presence of external Ca2+, the SR Ca2+ pump may have little effect on regulation of Ca2+ level in the contractile compartment. Furthermore, the release of Ca2+ from SR seems to have little effect on the increase in the contractile Ca2+ because ryanodine and caffeine changed neither the aequorin signals nor contractions induced by NA and high K+ in the presence of external Ca2+ in the ferret portal vein.

Adrenergic alpha-Agonists↗
PubMed1996

Nocturnal blood pressure and silent cerebrovascular lesions in elderly Japanese.

BACKGROUND AND PURPOSE: We conducted a cross-sectional epidemiological survey using ambulatory blood pressure monitoring and brain MRI in a cohort from northern Japan to determine whether an inappropriately low nocturnal blood pressure, or an excess fall in nocturnal blood pressure, might be responsible for silent cerebrovascular lesions in the elderly. METHODS: Untreated subjects over 55 years and under 64 years of age (late middle age; 24 men and 46 women, 60% of eligible people) and over 65 years and under 75 years of age (elderly; 29 men and 52 women, 91% of eligible people) participated in the study. We evaluated the relationship between the amplitude (Daytime Average-Nighttime Average) or the rate ([Daytime Average-Nighttime Average]/Daytime Average) of the fall in nocturnal blood pressure and the incidence of silent cerebrovascular lesions on MRI (number of lacunar infarctions or extent of periventricular hyperintensity). RESULTS: The amplitude or the rate of the fall in nocturnal blood pressure in elderly women with one or two lacunar infarctions was significantly higher than that in those without such infarctions. There was a significant positive correlation between the amplitude or the rate of the fall in nocturnal blood pressure and the extent of periventricular hyperintensity in the elderly women. This relationship was observed in women, but not in men, of late middle age; this was not seen in elderly men. CONCLUSIONS: Results indicate that an inappropriately low nocturnal blood pressure, or an excessive fall in nocturnal blood pressure, is associated with ischemic silent cerebrovascular lesions, at least in elderly women. Treatment of hypertension in such women should be administered with care and with regard to nocturnal blood pressure.

Age Distribution↗
PubMed1996

FR901483, a novel immunosuppressant isolated from Cladobotryum sp. No. 11231. Taxonomy of the producing organism, fermentation, isolation, physico-chemical properties and biological activities.

FR901483, a novel immunosuppressant, has been isolated from the fermentation broth of Cladobotryum sp. No. 11231. The molecular formula of FR901483 has been determined as C20H31N2O6P. FR901483 exerts a potent immunosuppressive activity in vitro and significantly prolongs graft survival time in the rat skin allograft model. This compound has an intriguing tricyclic structure possessing a phosphate ester in its molecule. The ester residue may play an important role in exerting immunosuppressive activity because the desphosphoryl compound is devoid of activity. It is thought that the primary target of immunosuppression by this compound is inhibition of purine nucleotide biosynthesis.

Animals↗
PubMed1996

Therapeutic advantages of angiotensin converting enzyme inhibitors in chronic renal disease.

More than other drugs, angiotension converting enzyme (ACE) inhibitors have been shown to provide better control of glomerular hypertension and improved preservation of renal function. Long-term treatment with captopril slows the progression of renal impairment in diabetic nephropathy; however, the data are inconclusive for non-diabetic nephropathies. ACE inhibitors such as captopril, enalapril, alacepril delapril cilazapril, and lisinopril were equally effective in reducing blood pressure in multicenter clinical trials focusing on renal hypertension in Japan. We studied the influence of ambulatory blood pressure (ABP) and the effects of hypertension therapy in 104 patients with chronic renal glomerulonephritis as diagnosed by renal biopsy. Patients were subdivided into hypertensive, normotensive and hypotensive groups according to ABP and ages. Hypotensive subjects showed an improvement, while normotensive subjects showed a slower rate of progression of renal function loss than hypertensive patients. This suggests that the adequate ABP levels were 100 to 125/55 to 75 in those who were less than 40 years old, 100 to 135/60 to 80 mm Hg in patients aged 40 to 60, and 105 to 140/60 to 85 mm Hg in those over 60 years old. The renal protective effects of calcium antagonists and ACE inhibitors were associated with a reduction in blood pressure, but not with the hypotensive action.

Adult↗
PubMed1996

[Growth inhibitory effects of ubenimex on leukemic cell lines resistant to chemotherapeutic agents].

Ubenimex (Bestatin, Ubx) has been shown to have anti-tumor activity and immuno-modulating activities. Ubx has been used in immuno-therapy in combination with remission maintenance chemotherapy after induction of complete remission for adult acute non-lymphocytic leukemia (ANLL, AML). Daunomycin (DNR), arabinosylcytosine (Ara-C) and 6-mercaptopurine (6-MP) are used for the standard chemotherapy for ANLL. It is, however, believed that emergence of resistant cells to chemotherapy cause minimal residual leukemia resulting in poor prognosis. Ubx has been administered in combination with these chemotherapeutic agents. We examined the combinatorial effect of Ubx with DNR, Ara-C, 6-MP and etoposide on K562 leukemic cell line and the chemotherapeutic agent resistant cells derived from K562 cell line. Ubx showed growth inhibitory effects on these cell lines. A synergistic effect was observed on growth inhibition and with colony formation of parent k562 cell line when DNR and Ubx were used in combination. A combination of Ubx with Ara-C or etoposide showed additional effects on parent cells and other resistant cell lines. The combined growth inhibitory effect of 6-MP and Ubx was stronger than the effect of 6-MP alone. These results show that Ubx has a direct growth inhibitory effect on leukemic cells and additional or synergistic effects are obtained on K562 leukemic cell line and on chemotherapeutic agent resistant cells derived from the K562 cell line when Ubx is used combination with the above chemotherapeutic agents.

Antibiotics, Antineoplastic↗
PubMed1995

Liquid chromatography combined with thermospray and continuous-flow fast atom bombardment mass spectrometry of glycosides in crude plant extracts.

In crude plant extracts, constituents of biological or pharmaceutical interest often exist in the form of glycosides. Off-line mass spectral investigations of these metabolites require soft ionisation techniques such as desorption chemical ionisation (DCI) or fast atom bombardment (FAB) if information on molecular mass or sugar sequence is desired. In LC-MS, glycosides can be ionised by using thermospray (TSP), continuous-flow fast atom bombardment (CF-FAB) or other interfaces. These techniques are thus potentially applicable to the on-line analysis of glycosides and can be applied to plant extract analysis. Thermospray (TSP) used with ammonium acetate as buffer provides mass spectra similar to those obtained with DCI-MS using NH3 and is potentially applicable to the on-line analysis of relatively small glycosides bearing no more than three sugar units. CF-FAB provides cleaner MS spectra than static FAB due to the lower concentration of the matrix used and can be applied to more polar compounds such as glycosides with a larger number of sugars. The use of a special setup involving post-column addition of the buffer or the matrix and splitting allows LC-UV, TSP LC-MS and CF-FAB LC-MS to be performed with the same standard HPLC conditions. Different crude plant extracts containing various types of glycosides with one to eight sugar units have been analysed by both TSP and CF-FAB. Cardenolides from Nerium odorum (Apocynaceae) and saponins from Swarzia madagascariensis (Leguminosae), Aster scaber and Aster tataricus (Asteraceae) have been studied by LC-MS. The combination of these two interfaces for the HPLC screening of crude plant extracts is discussed.

Cardenolides↗
PubMed1995

Hydrostatic pressure promotes the acidification of vacuoles in Saccharomyces cerevisiae.

Application of hydrostatic pressure caused a delay or cessation of cell growth in Saccharomyces cerevisiae. The yeast vacuole is an acidic organelle involved in cellular ion homeostasis and degradation of proteins. Hydrostatic pressure promoted the acidification of the vacuoles in the strain IFO 2347. A pressure of 40 to 60 MPa reduced the vacuolar pH, defined using 6-carboxyfluorescein, from 6.05 to 5.88, while a pressure of 20 MPa did not affect the pH. Similar results were obtained with the strain X2180. Bafilomycin A1, a specific inhibitor of vacuolar H(+)-ATPase (V-H(+)-ATPase), caused a significant alkalization of vacuoles in the strain X2180. The pHs rose to 7.34 and 6.84 at both atmospheric pressure and a pressure of 40 MPa, respectively. Meanwhile, vacuolar accumulation of the weak base quinacrine was increased by a pressure of 40 MPa, suggesting that uptake of the dye was induced by the increased pH gradient across the vacuolar membrane.

Anti-Bacterial Agents↗