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Biomedical subjects

N Ueno

Publications and source records attributed to N Ueno.

At least 253 records · Page 14Linked to original sources
PubMed1990

Activin as a cell differentiation factor.

Activin, originally discovered as a polypeptide hormone that is capable of stimulating follicle-stimulating hormone secretion from pituitary cells in vitro, has recently been found to have a much wider range of biological activities. There are a number of reports of activin action as a cell differentiation factor on various types of cells rather than as a modulator of hormone secretion, as predicted initially, based on its structural similarity to transforming growth factor-beta. Studies of the distribution of activin and its receptor in a variety of tissues and its wide-ranging actions clearly illustrates its multifunctional properties. In particular, activin has been shown to be a potential regulator of early development of Xenopus laevis. Observation of activin effect in embryogenesis is of general importance to our understanding of the role of the family of growth factors in developmental processes.

Activin Receptors↗
PubMed1990

Liquefaction of human vitreous in model aphakic eyes by 300-nm UV photolysis: monitoring liquefaction by fluorescence.

After the lens is removed in cataract surgery, the vitreous presumably receives all of the ambient 300-nm light that has filtered through the cornea. Using this model for aphakic eyes, we progressively irradiated intact vitreous samples of a 49-year-old human with 300-nm light and monitored changes in absorption, fluorescence, and circular dichroism (CD) properties. CD and fluorescence measurements of unirradiated vitreous samples showed a) a strong tryptophan fluorescence band of non-collagenous protein at 336 nm and a very weak band around 430 nm due to N-formylkynurenine (N-FK), a photoproduct of tryptophan, and b) a strong, negative CD band below 250 nm representing a composite spectrum of hyaluronic acid, collagen, and non-collagenous protein. Upon irradiation, the tryptophan emission band at 336 nm progressively decreased with time and the band maximum was concomitantly red-shifted; the N-FK fluorescence band at 430 nm, on the other hand, continually increased with the time of irradiation. A significant increase in the fluidity (liquefaction) of the vitreous gel also was noted upon irradiation, a change that was monitored successfully by measuring the progressive decrease in the polarization value of tryptophan fluorescence. The extent of liquefaction, measured spectroscopically, was found to be 40% upon irradiation for 10 hr. In addition, CD measurements indicated a partial loss in the secondary structure of the non-collagenous protein.

Aphakia, Postcataract↗
PubMed1990

[A medical treatment of esophageal varices by propranolol].

The effect of a long-term propranolol administration on portal hemodynamics, liver function tests and endoscopic findings of esophageal varices were evaluated in 27 patients with established esophageal varices. And the following results were obtained. 1) After a long-term propranolol administration, the portal vein pressure fell in 8 of 12 cases (75%), portal blood flow volume reduced in 12 of 13 cases (92.3%) and the improvement of endoscopic findings of esophageal varices were observed in 17 of 27 cases (63%). 2) No significant correlation between dosage and serum concentration of propranolol was observed, and the effective serum concentrations of propranolol were found to be different on each individual. 3) It is considered that the periodical observation of the changes of portal hemodynamics and the endoscopic findings of esophageal varices must be performed under the therapy of a long-term propranolol administration, because that the effect is different on each individual, and when the treatment is not effective, the dosage of the drug should be changed.

Adult↗
PubMed1989

Glycosaminoglycan conformations and changes on periodate oxidation.

The progressive periodate oxidation of glycosaminoglycans (GAG), including hyaluronate (HA), chondroitins (CH) (chondroitin, chondroitin 4- and 6-sulfate), dermatan sulfate (DS), and keratan sulfate (KS), were monitored by CD and high performance liquid chromatography (HPLC) using a size-exclusion column. The rate of oxidation also was measured and calculated using first- and second-order kinetics, and the data appear to fit better with first-order kinetics. In both HA and CH, the n - pi amide band at 208 nm decreases in intensity upon oxidation, but in HA it becomes positive after 16 h of periodate treatment. In CH, the band disappears, and the pi - pi amide band below 200 nm becomes optically active. Concomitantly, a second negative band near 290 nm appears for these two oxidized GAG. Oxidation causes a slight change in the CD of DS. It ordinarily displays a very weak n - pi band at 210 nm, but instead shows an intense pi - pi amide band near 190 nm. CD of KS remains unaffected by periodate. Kinetic studies, however, show a higher oxidation rate for DS than HA and CH. With the exception of KS, all other oxidized polymers shown an apparent decrease in molecular weight (higher peak retention time) in HPLC analysis. Both CD and HPLC results have been attributed to a major conformational change of HA and CH, and a minor one for DS. The ease and extent of periodate oxidation as well as the changes in molecular properties following periodate treatment are critically dependent on the configuration of the individual GAG rather than the oxidation rate. There is a distinct difference in the conformational change between HA and CH, as manifested by their dichroic behavior, that was attributed to the equatorial disposition of C-4 hydroxyl group in HA and axial disposition CH.

Carbohydrate Conformation↗
PubMed1989

[Experimental study on the effect of UFT with concomitant radiotherapy of uterine cervical cancer].

In order to examine effectiveness of the chemotherapy with concomitant radiotherapy, an experimental study was designed using AMCC-1 cell line established from a human uterine cervical carcinoma in our laboratory. The growth of AMCC-1 cells cultured in plastic flask was inhibited significantly in the group treated with a half of minimal effective doses of 60Co and 5-FU in comparison with the control group. The 5-FU treatment after radiation inhibited the AMCC-1 cell growth more effectively than that before radiation. The growth of AMCC-1 tumor transplanted into nude mice was inhibited significantly in the group given a combination chemoradiotherapy, consisted of oral administration of three quarters of minimal effective dose of UFT for fourteen consecutive days and radiation of a half of minimal effective dose of 60Co. The oral administration of UFT after radiation inhibited the AMCC-1 tumor growth more effectively than that before radiation. These results suggest that the radiotherapy with administration of UFT was more effective against uterine cervical cancer than radiation alone and it is important to administer UFT orally after radiation as well as before radiation.

Animals↗
PubMed1989

Spectral properties of human placental aldose reductase and aldehyde reductase II.

Circular dichroism and fluorescence spectra of aldose reductase (E.C.1.1.1.21) and aldehyde reductase II (E.C.1.1.1.19) purified to homogeneity from human placenta have been studied. The alpha helical content of aldose reductase and aldehyde reductase II was 51% and 56%, respectively, whereas no beta helical structure was found in either case. In the case of aldose reductase, the secondary structure was unaffected at alkaline pH (9.5), whereas a drastic alteration in the structure was observed at 58 degrees C. The secondary structure of aldehyde reductase II, on the other hand, remained unaffected at higher pH and temperature.

Aldehyde Reductase↗
PubMed1989

[Visualization of blood flow in abdominal tumors by the ultrasonic pulsed Doppler method].

The clinical utility of visualizing the blood flow in the margin and inside of tumors by ultrasonic pulsed Doppler method (UPDM) was evaluated in 54 patients (85 lesions) with various abdominal tumors. It was proved that UPDM was able to evaluate the vascularity of the tumor and the surrounding vascular system. These results indicate that this method may be applied clinically for judging the effects of and the indications for the transcatheter arterial embolization (TAE) therapy. It is also suggested that UPDM may be applied in the differential diagnosis of tumors according to the changes of blood velocity and wave patterns.

Abdominal Neoplasms↗
PubMed1989

[Evaluation of the effect of premenopausal oophorectomy on bone mineral content].

The effects of premenopausal oophorectomy on bone mineral content (BMC) and serum parameters of bone metabolism, ie E2, PTH, Ca, P, ALP, BGP, 1-25(OH)2D3 were studied. The BMC of the spongiosum of L-3 vertebral body was calculated by means of computed tomography which was utilized in conjunction with a calibrated phantom containing a set of reference densities (CaCO3). The BMC tended to decrease markedly in the late 40s (r = -0.669, p less than 0.01) and a 38% decrease was found among the postmenopausal group (age 50-60) in comparison with the premenopausal group (age 40-49) (206.9 +/- 38.0 vs 128.5 +/- 32.7 mg/cm3, p less than 0.005). In cases of premenopausal bilateral oophorectomy (mean age 42.5) the BMC was found to decrease significantly about 2 years after the operation (150.0 +/- 25.2 mg/cm3, p less than 0.005), while no significant difference was found between the controls (mean age 43.5) and unilateral oophorectomized cases (mean age 40.3). Findings that indicated a decrease in E2, a significant increase in BGP and ALP, and a tendency for PTH to decrease were noted among bilateral oophorectomized cases and this may indicate accelerated osteogenesis. It was suggested that premenopausal bilateral oophorectomized cases are in danger of developing severe osteoporosis and are candidates for rigorous preventive treatment.

Adult↗
PubMed1989

Establishment and characterization of a new human cell-line (AMOC-2) derived from a serous adenocarcinoma of ovary.

A new cell line, designated as AMOC-2, was established from a mouse graft of human ovarian serous adenocarcinoma, and has grown well without interruption for over 12 months. The cultured cells of the AMOC-2 line were spindle or polygonal in shape and showed a monolayer growth with a pavement-like arrangement and a slight tendency to pile up, thus lacking contact inhibition. This cell line has a doubling time of 17.4h, a saturation density of 9.17 X 10(4) cells/cm2, a plating efficiency of 36.2% and a mitotic coefficient of 6.2%. The chromosomal number of this cell line is distributed in the diploid range and three of the specific marker chromosomes were identified in the cells with 49 chromosomes. This cell line was able to be transplanted into the subcutis of nude mice and produced a poorly differentiated serous adenocarcinoma resembling the original tumor. These cells have maintained their tumorigenic capacity despite prolonged maintenance in culture and are now in the 60th passage.

Animals↗
PubMed1988

Monitoring in situ circular dichroism of the intact vitreous: a new approach.

For the first time, an attempt has been made to study the vitreous humor in situ by circular dichroism (CD). The vitreous, an avascular and acellular gel-like tissue, is optically transparent and homogeneous, and, thus, light scattering is minimal. The macromolecular components of this tissue, hyaluronate (HA), collagen and noncollagenous protein (NC-P), appear to exist in the matrix in a nonoriented fashion. As a result, no linear dichroism was observed. A typical CD of the vitreous shows a minimum at 206 nm with a shoulder at 220 nm and one small positive peak at approximately 252 nm. Gaussian analysis resolves this spectrum into four component bands. CD analysis of individual components reveals that NC-P makes the major contribution to the dichroic strength of the vitreous; contributions of HA and collagen, on the other hand, are small. The positive peak arises largely from ascorbic acid in the vitreous. CD measurement of the intact vitreous appears to be a useful technique for assessing the structure and changes of the constituent molecules in the normal and diseased vitreous.

Animals↗
PubMed1988

Extraction of retinol and cholesterol by intraocular silicone oils.

According to their solubility parameters, retinol and its derivatives, as well as cholesterol and other lipophilic substances, are predicted to dissolve in intraocular silicone and fluorosilicone oils. Calf retinas were extracted in vitro with these oils and the oils then analyzed spectrophotometrically. The following levels were found after extraction for 4 and 48 hours, respectively: for retinol, silicone oil, 0.5 and 3.7 micrograms/ml, and fluorosilicone oil, 0.5 and 3.3 micrograms/ml; for cholesterol, silicone oil, 0.5 and 6.4 micrograms/ml, and fluorosilicone oil, 0.8 and 3.7 micrograms/ml. In in vivo experiments, intraocular oils were removed from rabbit eyes at 4 days to 10 weeks after injection. The retinol levels were 1.7 to 11.4 micrograms/ml in silicone oil and 2.4 to 7.3 micrograms/ml in fluorosilicone oil; the cholesterol levels were 2.7 to 12.6 micrograms/ml in silicone oil and 7.5 to 15.6 micrograms/ml in fluorosilicone oil. Fluorosilicone and silicone oils (1000 cs) removed from human eyes at 7.3 and 102.0 weeks postoperatively had a retinol content of 5.4 and 2.9 micrograms/ml, respectively. Silicone oil of 1000 cs removed from a patient 51 weeks postoperatively and silicone oil of 12,500 cs removed 96 weeks postoperatively gave reaction characteristics for cholesterol, 230 and 99 micrograms/ml, respectively.

Animals↗
PubMed1988

Primary structure of the human follistatin precursor and its genomic organization.

Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. By use of the recently characterized porcine follistatin cDNA as a probe to screen a human testis cDNA library and a genomic library, the structure of the complete human follistatin precursor as well as its genomic organization have been determined. Three of eight cDNA clones that were sequenced predicted a precursor with 344 amino acids, whereas the remaining five cDNA clones encoded a 317 amino acid precursor, resulting from alternative splicing of the precursor mRNA. Mature follistatins contain four contiguous domains that are encoded by precisely separated exons; three of the domains are highly similar to each other, as well as to human epidermal growth factor and human pancreatic secretory trypsin inhibitor. The genomic organization of the human follistatin is similar to that of the human epidermal growth factor gene and thus supports the notion of exon shuffling during evolution.

Adult↗
PubMed1988

Myelin basic protein present in the acid extracts of rat hypothalami releases insulin and glucagon from isolated rat pancreatic islets.

The insulinotropic and glucagon-releasing activity of acid extracts of rat hypothalami were tested in two bioassay systems using short-time incubation of isolated rat pancreatic islets and a rat insulinoma (RIN) cell line. Release of insulin and glucagon into the incubation medium was measured by radioimmunoassay. The major insulin-releasing and glucagon-releasing activity eluted in a broad zone in Sephacryl S-200 gel filtration in 30% acetic acid corresponding to the molecular weights between approximately 10 and 40 kD. The highest activity was eluted in a zone corresponding to 14 kD and was purified to homogeneity by means of two steps of reversed-phase HPLC. Amino acid analysis and SDS polyacrylamide gel electrophoresis indicated that the biologically active material was the rat small (myelin) basic protein characterized previously by Dunkley & Carnegie (1974). The purified rat hypothalamic material showed insulinotropic and glucagon-releasing activity indistinguishable from that of purified porcine myelin basic protein, and lost its insulinotropic activity when incubated with anti-myelin basic protein immunosorbent. We conclude that the major insulin-releasing and glucagon-releasing activity in acid extracts of the high-molecular-weight fractions of rat hypothalami is myelin basic protein.

Amino Acids↗
PubMed1988

BCNU in silicone oil in proliferative vitreoretinopathy: I. Solubility, stability (in vitro and in vivo), and antiproliferative (in vitro) studies.

Various pharmacologic agents have been tried to control proliferative vitreoretinopathy (PVR). However, most are water soluble and cannot be used with silicone oil (SO), a tamponade agent also used in PVR management. We evaluated a lipophilic, antiproliferative drug, BCNU, in regard to its solubility and stability in SO, its release from SO into an aqueous solution, and its effect on cell cultures. BCNU is soluble in SO (peak concentration in micrograms/ml 1020, 750, and 294 at 37 degrees C, 21 degrees C, and 4 degrees C, respectively), and stable (half-life = 6.7 weeks at 37 degrees C, 17.9 weeks at 21 degrees C). At 4 degrees C, no significant decrease in concentration up to eight weeks was noted. BCNU is released from SO to water (partition coefficient = 10.28 +/- 2.16). Its median inhibitory doses (ID50) on bovine retinal pigment epithelial (RPE), rabbit RPE, and subconjunctival fibroblast cells are 13, 1.9, and 15.6 micrograms/ml, respectively. BCNU may be a useful pharmacologic tool to control PVR.

Animals↗