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Biomedical subjects

F Suzuki

Publications and source records attributed to F Suzuki.

At least 523 records · Page 29Linked to original sources
PubMed1983

Tuberous sclerosis: proline and hydroxyproline contents in serum.

The serum levels of proline and hydroxyproline were determined by high-performance liquid chromatography using the post-labeled method with o-phthalaldehyde and sodium hypochlorite in 30 patients of tuberous sclerosis (TS) and compared with those in 32 pathological control subjects of similar age. No significant difference in the levels of serum free hydroxyproline was observed between TS and controls in any age group. In the age group of 9 to 18 years, TS showed significantly higher mean free proline levels in serum than controls with a difference of about 50 mumol/L. In both groups of TS and controls, total and free levels of hydroxyproline from ethanol-extractable serum showed similar age-dependent curves with peak values at age 12 years, and there was also no difference in the 2 levels between the 2 groups. It is suggested that this higher free proline level in TS with the autosomal dominant trait may be explained as the abnormal regulation of proline metabolism.

Adolescent↗
PubMed1983

Decrease in adipose S-100 protein levels by epinephrine in rat.

Soluble S-100 protein levels in epididymal adipose tissue of male rats (1.3 +/- 0.1 micrograms/mg protein) were markedly decreased (to 0.15 +/- 0.06 microgram/mg protein) by serial injection of epinephrine (0.1 mg/day for 9 days). But injection of insulin in a similar manner (4 U/day for 9 days) had little effect on the adipose S-100 protein levels (1.1 +/- 0.2 micrograms/mg protein). The S-100 protein levels in cerebrum, spleen, and adrenal gland were not affected by epinephrine or insulin administration. These results strongly suggested that S-100 protein levels in adipose tissue are regulated hormonally.

Adipose Tissue↗
PubMed1983

Role of polyamines in expression of the differentiated phenotype of chondrocytes: effect of DL-alpha-hydrazino-delta-aminovaleric acid (DL-HAVA), an inhibitor of ornithine decarboxylase, on chondrocytes treated with parathyroid hormone.

Previously, it was demonstrated that parathyroid hormone (PTH) induces a series of events, successive increases of the level of cyclic AMP, the activity of ornithine decarboxylase [ODC; EC 4.1.1.17] and glycosaminoglycan synthesis, a characteristic chondrocyte phenotype, in rabbit costal chondrocytes in culture. Cyclic AMP analogues also increase ODC activity and glycosaminoglycan synthesis in these cells. Therefore, in the present work, the role of polyamines in expression of the differentiated phenotype of chondrocytes was investigated. DL-alpha-Hydrazino-delta-aminovaleric acid (DL-HAVA), a potent inhibitor of ODC, inhibited the increase in polyamine levels of quiescent cultures of chondrocytes treated with PTH. DL-HAVA also inhibited stimulation of expression of the differentiated phenotype of chondrocytes by PTH, as judged by decreases in glycosaminoglycan synthesis and metachromasia on toluidine blue staining. Similarly, DL-HAVA inhibited stimulation of expression of the differentiated phenotype of chondrocytes by dibutyryl cyclic AMP. The inhibitory effect on expression of the differentiated phenotype of chondrocytes by DL-HAVA was effectively diminished by addition of polyamines. Under the same conditions, PTH, DL-HAVA, or polyamines had little effect on DNA synthesis. These findings suggest that the rise in polyamine levels induced by PTH, which is mediated by an increase of cyclic AMP concentration, is essential for expression of the differentiated phenotype of chondrocytes.

Animals↗
PubMed1983

Increase in S-100 protein levels in blood plasma by epinephrine.

The level of S-100 protein in rat blood plasma (about 1.4 ng/ml), which was detectable by the present immunoassay method, was markedly increased by a single injection of epinephrine (5 h after injection, 19.7 +/- 5.2 ng/ml). The S-100 protein thus increased was eluted in the same fractions as that of rat brain on butyl-Sepharose 4B column chromatography. The S-100 protein levels were also enhanced moderately by norepinephrine and slightly by isoproterenol, but not by insulin. It is strongly suggested that the increased S-100 protein in blood plasma is derived mainly from the adipose tissue through the effect of catecholamines.

Animals↗
PubMed1983

Electrophysiologic evaluation of antiarrhythmic drugs on supraventricular tachyarrhythmias.

The effects of the intravenous administration of three drugs, i.e., verapamil, disopyramide, and procainamide, on paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation (Af) and atrial flutter (AF) were evaluated electrophysiologically. Efficacy on PSVT was 94.7% (36/38) with verapamil, 61.5% (13/18) with disopyramide and 100% (4/4) with procainamide. Efficacy on Af and AF was 9.1% (1/11) with verapamil and 80.0% (12/15) with disopyramide. PSVT termination mechanisms were as follows: 1) Verapamil: A-H block in 5 cases and H-A block in 5 cases with Type 1 A-V nodal reentrant tachycardia (AVNRT). H-A block in 6 cases with Type 2 and Type 3. A-H block in 17 of 18 cases with A-V reciprocating tachycardia (AVRT). Cycle length alternans were observed in 13 of 34 cases. 2) Disopyramide: H-A block in 2 cases with AVNRT and V-A block in 2 cases with AVRT. 3) Procainamide: V-A block in 4 cases with AVRT. These results suggest that verapamil and disopyramide are most effective on PSVT and Af, respectively.

Anti-Arrhythmia Agents↗
PubMed1983

Effect of multiplication-stimulating activity (MSA) on the cyclic AMP level and proteoglycan synthesis in cultured chondrocytes.

Multiplication-stimulating activity (MSA), a somatomedin purified from conditioned medium of Buffalo rat liver cells, had little effect on the intracellular level of cyclic AMP when it markedly enhanced the synthesis of sulphated glycosaminoglycans in rabbit chondrocytes in culture. In addition, MSA did not inhibit prostaglandin E1- or parathyroid hormone-induced accumulation of cyclic AMP in the chondrocytes. On the contrary, MSA slightly decreased stimulation of cyclic AMP accumulation by prostaglandin in human fibroblasts. Dibutyryl cyclic AMP and MSA increased the incorporation of [35S]sulphate and [3H]serine into proteoglycans synthesized by rabbit chondrocytes, and their effects were additive. These findings suggest that somatomedin and dibutyryl cyclic AMP enhance sulphate proteoglycan synthesis through different mechanisms. The lack of inhibitory effect of MSA on cyclic AMP accumulation may be favourable for producing additive effects with cyclic AMP on proteoglycan synthesis and DNA synthesis in chondrocytes.

Alprostadil↗
PubMed1983

Antiviral effect of interferon on influenza virus infection in mice.

The antiviral effect of highly purified mouse interferon (IFN) was studied on influenza virus infection in mice, by changing the routes of administration. By repeated intravenous (i.v.) administrations of IFN, no antiviral effect was observed. However, IFN was effective when the infected mice received either intraperitoneal (i.p.) or intranasal (i.n.) administrations. While all of the untreated mice died within 10 days after infection, 20% of the i.p. treated mice and 67% of the i.n. treated mice survived more than 30 days. To explain these different effects after administration by different routes, the distribution of given IFN in mouse organs was examined. Fifteen min after i.v. injection, only a low-titered IFN was detected in the serum, lung, spleen and liver of the mice and soon disappeared. However, a relatively high-titered IFN was detected 30 min after i.p. administration in the lung and serum. After i.n. administration, high-titered IFN was detected in the lung within 15 min after administration and continued for 90 min. Thus the findings demonstrated that the maintenance of a detectable amount of IFN in mice organs is dependent on the route of administration, and the higher the titer of IFN in the lung, the higher the protective effect of IFN against influenza virus infection.

Administration, Intranasal↗
PubMed1983

Electrophysiologic study on atrioventricular nodal reetrant tachycardia with special reference to recent controversies.

Electrocardiographic and electrophysiologic studies were performed in 21 patients with atrioventricular (A-V) nodal reentrant tachycardia (AVNRT). Patients were classified into three types according to the patterns during the tachycardia, i.e., (1) type I; an atrial echo (Ae) occurred simultaneously with a ventricular electrogram (VE) (14 patients), (2) type II; an Ae occurred in front of the next VE (four patients) and (3) type III; an Ae followed immediately after the preceding VE (three patients). All patients with type I AVNRT showed discontinuous A-V and continuous ventriculoatrial (V-A) conduction curves. "Enhanced V-A conduction" (1:1 V-A conduction at the ventricular paced rate of 200 beats/min) was demonstrated in five of the 14 and after verapamil in two of the five patients. In type II AVNRT the tachycardia was initiated with a minimal amount of A-V nodal conduction delay and second degree A-V or V-A block was observed in all four patients. V-A conduction was poor in these patients. In type III AVNRT A-V conduction curves were discontinuous and retrograde study revealed the presence of retrograde dual A-V nodal pathways. In conclusion, A-V and V-A conduction in patients with AVNRT were variable and this variability seemed to be responsible for different patterns of AVNRT.

Adolescent↗
PubMed1983

Enhancement of adipose S-100 protein release by catecholamines.

When rat epididymal fat-pad pieces were incubated in vitro with 10 microM epinephrine, S-100 protein in the tissue was markedly decreased by release into the medium. The release of adipose S-100 protein was also enhanced by norepinephrine (10 microM), isoproterenol (10 microM), and dibutyryl cyclic AMP (5 mM), but not by insulin (0.8 microM). The enhancement of S-100 protein release by 10 microM epinephrine was completely inhibited by 10 microM propranolol. These results suggest that the release of adipose S-100 protein is regulated by the beta-adrenergic effect of catecholamines.

Adipose Tissue↗
PubMed1982

Measurement of enolase molecules in the single preimplantation rat embryo by an enzyme immunoassay system.

The amount of enolase (EC 4.2.1.11) molecules in a single preimplantation rat embryo was determined by an enzyme immunoassay system. An advantage of this assay system is its ability to distinguish each isozyme (alpha alpha, alpha gamma and gamma gamma forms) by using the specific antisera to alpha and gamma subunits. The isozyme of enolase was mostly the alpha alpha form through one-cell to blastocyst stages, whereas the alpha gamma and gamma gamma forms were scarcely detected. Since the immunoassay system is highly sensitive, and minimum amount detectable being 1 amol (1 X 10(-18) mole), the amount of alpha alpha form enolase could be determined in single embryos in all preimplantation stages. The results have revealed that the amount of alpha alpha form enolase molecules does not change through one-cell to morula stages, but increases remarkably between morula and blastocyst stages.

Animals↗
PubMed1982

Purification of two enolases from human brain using a chromatofocusing column.

When a purified preparation of rat alpha gamma enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) was applied to a chromatofocusing column, the enolase was almost completely dissociated and recombined to form alpha alpha and gamma gamma enolases, which were eluted at different fractions from the column. Using these phenomena, two homo-dimer forms (alpha alpha and gamma gamma) of human brain enolase were purified from a crude preparation of the hybrid alpha gamma enolase by the chromatofocusing, and subsequent chromatography on a QAE-Sephadex column (alpha alpha) or a DEAE-Sephadex column (gamma gamma). Each purified preparation showed a single band on SDS-gel electrophoresis with a relative mobility corresponding to a molecular weight of about 50 000. Amino acid analysis, peptide mapping analysis with a limited proteolysis and immunochemical studies of the purified alpha alpha and gamma gamma enolases revealed that the two subunits, alpha and gamma, are distinct proteins. The antisera to human alpha alpha or gamma gamma enolase cross-related with the respective form of rat enolase.

Amino Acids↗
PubMed1982

Distribution of nervous system-specific forms of enolase in peripheral tissues.

The distribution of 3 forms of rat enolase (alpha alpha, alpha gamma and gamma gamma forms), including nervous system-specific forms (alpha gamma and gamma gamma), was determined in various tissues with a sensitive enzyme immunoassay system. The brain and spinal cord contained more than 100 pmol/mg protein of the alpha alpha, alpha gamma and gamma gamma enolases. Organs such as the lungs, heart, spleen, liver, and kidney contained similarly high levels of alpha alpha enolase, but these tissues contained alpha gamma and gamma gamma enolases at levels less than 1% of the central nervous tissues. High levels of the alpha gamma (greater than 10 pmol/mg) and the gamma gamma (greater than 1.5 pmol/mg) forms were found in rectum, bladder, and uterus. In gut, major portions of the nervous system-specific forms were localized in the muscle layers. Skeletal muscle and diaphragm, which are composed of striated muscle, contained low levels of 3 forms of enolase. Megakaryocytes separated from the suspension of bone marrow contained 11.3, and 0.53 amol/cell of the alpha alpha and gamma gamma enolases, respectively, with little, if any, of the alpha gamma form.

Animals↗
PubMed1982

Restoration by cyclic AMP of the differentiated phenotype of chondrocytes from de-differentiated cells pretreated with retinoids.

Parathyroid hormone (PTH) increases the cyclic AMP level in rabbit costal chondrocytes in culture. PTH, dibutyryl cyclic AMP (DBcAMP), and 8-bromo cyclic AMP (8-Br cAMP)induce ornithine decarboxylase (ODC) and expression of the differentiated phenotype of chondrocytes in this cell system. On the other hand, retinoids inhibit expression of the differentiated phenotype of chondrocytes. In the present study, the effects of PTH, DBcAMP, and 8-Br cAMP on rabbit costal chondrocytes pretreated with retinoids were examined. PTH did not increase the cellular cyclic AMP level in de-differentiated cells that had been pretreated with retinyl acetate or retinoic acid for three days, but it did increase the cyclic AMP level four days after removal of retinoids. PTH did not stimulate ODC activity or expression of the differentiated phenotype of chondrocytes in the de-differentiated state. On the other hand, DBcAMP or 8-Br cAMP stimulated expression of the differentiated phenotype of chondrocytes even in de-differentiated cells, as judged by morphological and histological changes of the cells and increase in glycosaminoglycan synthesis. Cyclic AMP analogues also induced ODC in these cells.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1982

Further observations on the Sertoli cell junctions of the mouse testis after metal contract freeze-fracture, and comparisons with cellular junctions of other epithelial cells.

Using a metal contact freezing methods, the junctional complexes of Sertoli cells and other epithelial cells (intestine, liver, and epididymis) in the mouse were studied by freeze-fracture in unfixed and in aldehyde-fixed specimens. The tight junctions of the Sertoli cells without fixation consists of discrete rows of particles located preferentially on the E face. Continuous furrows with or without tight-junctional particles are found on both fractured faces. The majority of the tight-junctional particles of th Sertoli cells are situated at one side of the furrow rather than in the center. The "aisle" configuration of the gap junction is seen in developing Sertoli cells prepared without fixation. Tight junctions of epithelial cells other than Sertoli cells consists of discrete rows of particles on the E face and furrows on the P face when prepared without fixation. The tight and gap junctions of the Sertoli cells are not affected by fixation, but the tight junctions of other types of epithelial cells are effected as previously suggested. A distribution pattern of the gap-junctional particles of the Sertoli cells and of other cells shows a pleomorphism. Changes in gap junctions produced by fixation could not be detected clearly. Characteristics of the Sertoli-cell junctions are discussed. Desmosomes between the intestinal epithelial cells without fixation are presented.

Animals↗
PubMed1982

Microvasculature of the mouse testis and excurrent duct system.

The microvascular architecture of the mouse testis and excurrent duct system was examined by a casting method with the aid of scanning electron microscopy and by sectioning techniques for light and transmission electron microscopy. Two fundamental types of peritubular capillary arrangements were noted in relation to the tubules. The first type most typically appeared in the testis. In this type, peritubular capillaries interconnected intertubular blood vessels to form a rope-ladder-like structure. The length of the individual peritubular capillaries was short, and a number of the capillaries encircled each tubule. Adjacent tubules shared a single layer of capillaries. The vascular organization of the ductuli efferentes and of the middle segment of the epididymis was also of this type, but the number of peritubular capillaries was much fewer compared with that of the testis. In the second type, the peritubular capillaries formed a network encircling each tubule in its subepithelial layer. The capillary organization in the initial and terminal segments of the epididymis and the ductus deferens belonged to the second type. In the distal part of the ductus deferens, a prominent venous plexus was formed in the most peripheral subepithelial layer.

Animals↗