Search PubMed⌕ Search

Biomedical subjects

S Inagaki

Publications and source records attributed to S Inagaki.

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

Identification of a novel transmembrane semaphorin expressed on lymphocytes.

Semaphorin (also known as collapsin) members are thought to be involved in axon guidance during neural network formation. Here, we report the isolation of a novel member, mouse semaphorin G (M-sema G), which encodes a semaphorin domain followed by a single putative immunoglobulin-like domain, a transmembrane domain, and a cytoplasmic domain. M-sema G is most closely related to M-sema F, which we previously reported, and semB and semC. These four members appear to constitute a transmembrane type subfamily in mouse semaphorins. In contrast to the predominant expression of M-sema F mRNAs in the nervous tissues, M-sema G mRNAs are strongly expressed in lymphoid tissues, especially in the thymus, as well as in the nervous tissues. The mRNAs are also detected in various cell lines from hematopoietic cells. By generating specific antibodies, we confirmed the strong expression of M-Sema G proteins on the surface of lymphocytes. These results provide the first evidence that semaphorin is expressed on lymphocytes and suggest that semaphorins may play an important role in the immune system, as well as in the nervous system.

Amino Acid Sequence↗
PubMed1996

Localization of mRNAs for Rlim-1, the rat Xlim-1 homolog, in the developing rat brain.

We studied the localization of Rlim-1 mRNAs, the rat Xlim-1 homolog, in the developing rat brain using in situ hybridization histochemistry. On embryonic day 13 (E13), strong signals were observed in the most superficial layer of the telencephalon, the zonalimitans intrathalamica, the ventral thalamus, some nuclei of the hypothalamus, the tectum, the cerebellum, the lower brainstem and the spinal cord. In the above-mentioned regions except the cerebellum, the distribution pattern remained almost the same from embryonic stage to adulthood but the intensity of expression gradually decreased after birth. In the cerebellum, the distribution pattern changed. during development; all the primordium of cerebellum in E13, the external granular and the Purkinje cell layers in postnatal day 7 (P7), and only the Purkinje cell layer in the adult expressed positive signals. These results suggest that Rlim-1 may be involved in region specification.

Animals↗
PubMed1996

Differential distribution of mRNA encoding cAMP-specific phosphodiesterase isoforms in the rat brain.

We studied the distributions of four different cyclic AMP-specific phosphodiesterase isoform mRNAs (APDE1-4) and compared them with that of 63 kDa calmodulin-stimulated phosphodiesterase (CPDE) in the rat brain by in situ hybridization histochemistry using specific radiolabeled oligonucleotides. The distribution patterns were unique for all the APDE isoforms examined here. Although no significant signals for APDE1 could be detected anywhere in the rat brain, all other isoforms were expressed ubiquitously but unevenly and showed overlapping distribution patterns. Among all the APDE isoforms studied here, APDE3 showed the strongest and the most extensive expression. Its distribution pattern implies that it may modulate different cellular processes associated with learning and memory. Compared to APDE3, the levels of expression of APDE2 and APDE4 were weaker, the latter showing the weakest expression. Our study suggests that different isoforms of APDE are expressed together in the same class of neurons implying complex interactions among different signaling pathways, thereby mediating distinct and specific functions.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-MIBG and 201Tl in congestive heart failure.

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-meta-iodobenzylguanidine (123I-MIBG) and 201Tl in various organs was performed in 13 patients with congestive heart failure (CHF) and 13 subjects without heart failure. In order to reduce the crosstalk of 201Tl to the 123I energy window to less than 5%, a dose of 123I-MIBG more than five times greater than that of 201Tl was administered following 201Tl scintigraphy. Regional uptake of 201Tl (%dose) was significantly increased in the heart (left ventricle) and lung (both P < 0.01) in the patients with CHF. The increased global cardiac uptake could have been related to the enlarged left ventricle. The patterns of regional uptake of 123I-MIBG (% dose) at 15 min were similar to those of 201Tl, suggesting that early 123I-MIBG uptake could in part depend on regional perfusion in both groups. At 3 h, regional uptake of 123I-MIBG was significantly increased in the heart, lung and kidney (all P < 0.01) in the patients with CHF. The delayed 123I-MIBG uptake indicates the degree of neuronal accumulation of the tracer, and therefore reflects adrenergic activity. Interestingly, the cardiac 123I-MIBG (adrenergic activity) to 201Tl (unit of perfusion) ratio decreased significantly in the heart (P < 0.01) but increased significantly in the kidney (P < 0.01) in the patients with CHF compared with the control group. Cardiac 123I-MIBG washout was also significantly increased in the CHF patients. Moreover, the cardiac 123I-MIBG:201Tl ratio was negatively correlated with plasma norepinephrine concentration (r = -0.74, P < 0.01), but positively correlated with LVEF (r = 0.60, P < 0.01). These data suggest that there may be impairment of both the neuronal uptake function and the vesicular storage function in the failing heart, and an increment in neuronal uptake function in the kidneys in patients with CHF. We suggest that dual-tracer scintigraphy is a useful non-invasive method for the simultaneous assessment of adrenergic activity and perfusion in various organs in patients with heart failure.

3-Iodobenzylguanidine↗
PubMed1995

Identification of a member of mouse semaphorin family.

Grasshopper semaphorin I (Sema I) and its related proteins, chick collapsin and mouse Sema III contribute to the axon guidance by their repellent actions [5,9,12]. We have identified a member of semaphorin gene family from the mouse brain and named it M-Sema F. The N-terminal encodes a semaphorin domain that is similar between Sema I-III [6] followed by a single putative immunoglobulin-like domain, a transmembrane domain, and a proline-rich intracellular domain. M-Sema F mRNA is expressed widely in the nervous tissues during development. These suggest that M-Sema F is a transmembrane member of the semaphorin family of the vertebrate which may function in the developing neuronal network.

Amino Acid Sequence↗
PubMed1995

Whole-body 201Tl scintigraphy during one-leg exercise and at rest in normal subjects: estimation of regional blood flow changes.

To determine the effect of exercise intensity on regional blood flow in exercising and resting leg muscles and organs, we assessed relative changes in the regional distribution of 201Tl during one-leg ergometer exercise and at rest by whole-body scintigraphy as an estimate of regional blood flow changes in 10 healthy males. The regional 201Tl activity was expressed as a percentage of the whole-body activity, and relative changes in each region were compared to those at the anaerobic threshold (AT) and at peak exercise. In the legs, the distribution of 201Tl in the exercising thigh and calf increased significantly at the AT to 390.7 and 219.2% respectively of resting levels (both P < 0.01), but remained unchanged the resting thigh from rest to peak exercise. Conversely its distribution in the resting calf decreased significantly at the AT to 60.0% of the resting level (P < 0.01). However, there were no significant differences between AT and peak exercise. In the organs, the distribution of 201Tl in the lung, liver, spleen and kidneys decreased significantly at the AT to 88.4 +/- 10.4%, 67.0 +/- 11.5%, 62.4 +/- 11.8% and 67.0 +/- 8.6% respectively of resting levels (all P < 0.01). Redistribution of blood flow to the exercising leg occurs predominantly during mild to moderate exercise. Therefore, blood flow in the leg during strenuous exercise depends primarily upon an increase in cardiac output. The splanchnic organs are the major sources of redistribution.

Adult↗
PubMed1995

Testicular spermatid and epididymal sperm head counts as an indicator for reproductive toxicity in rats.

The testes of rats were exposed to a single soft x-ray irradiation at levels of 10, 25 and 63 Gy. Testicular and cauda epididymal weights and their sperm counts were decreased at 7 weeks after the irradiation. Histologically, there was an evidence of interrupted spermatogenesis dose-dependently. Animal mating trails, in which irradiated males were mated with untreated females revealed a slight increase in early stage of postimplantation loss at as low as 10 Gy. There were increases in preimplantation and early stage of postimplantation losses in the group of irradiated at 25 Gy. Infertility occurred in irradiated males at 63 Gy. The effects of irradiation were more severe on the sperm count parameters than on reproductive organ weights, histological examination and reproductive status. The testicular spermatid and epididymal sperm head counts are considered to be useful indicators to detect quantitatively the adverse effects on spermatogenesis.

Animals↗
PubMed1995

Effects of UFT (mixed compound of tegafur and uracil) on cell kinetics and inhibition of thymidylate synthase in L1210 ascites tumor.

Previous work in our laboratory showed that UFT (mixed compound of tegafur and uracil, molar ratio 1:4, respectively) caused the prolonged reduction of dTTP in L1210 leukemia cells in comparison with 5-fluorouracil (5-FU). The purpose of this study was to assess the effect of UFT on cell cycle distribution and thymidylate synthase activity of a leukemia cell line as compared with 5-FU. UFT and 5-FU were orally given to BDF1 mice bearing L1210 ascites tumor on day 3 after the tumor inoculation. Cell cycle distribution patterns at 24 hr after the drug administration showed a higher percentage of S phase in tumor cells treated with UFT than in those treated with 5-FU. Until 6 hr after the oral administration of the drugs, UFT inhibited the incorporation of [3H] deoxyuridine into DNA more long than 5-FU did. These results indicated that UFT has longer and stronger inhibitory effects on DNA replication than 5-FU in vivo under the employed experimental conditions (i.e., low and single doses of these fluorinated pyrimidines).

Animals↗
PubMed1995

Effects of photodegradation products of nifedipine: the nitroso-derivative relaxes contractions of the rat aortic strip induced by norepinephrine and other agonists.

Effects of four photodegradation products of nifedipine (nitroso-, nitro-, azoxy- and N,N'-dioxide-derivatives) were studied in the rat aortic strip suspended in the bath medium. In the CaCl2-free bath medium containing 40 mM KCl, CaCl2 (2.5 mM) induced contraction, which was relaxed by nifedipine (-log [EC50] = 8.66 M) and all the four photodegradation products (-log[EC50] = 4.15-4.82 M). The EC50 values for all these substances were not affected by denuding the vessel of endothelium. In the bath medium containing KCl (15 mM), Bay K-8644 (2 x 10(-6) M) induced contraction, which was relaxed by nifedipine (10(-9)-10(-6) M) and its four photodegradation products (3 x 10(-6)-10(-4) M). Norepinephrine (10(-7) M) induced contraction, which was relaxed by the nitroso-derivative (10(-4) M) noncompetitively (pIC50 = 4.37) but not by three other photodegradation products. Both methylene blue and hemoglobin had no effect on the relaxation produced by the nitroso-derivative. Phorbol 12-myristate 13-acetate induced contraction, which was inhibited completely by the nitroso-derivative (10(-4) M) but only by 42% by nifedipine (10(-4) M). Prostaglandin F2 alpha (3 x 10(-6) M), endothelin-1 (10(-9) M) and 5-hydroxytryptamine (10(-6) M) also induced contraction, which was relaxed effectively by the nitroso-derivative (10(-4) M) but not by any of the three other photodegradation products.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1994

Distribution of Rlim, an LIM homeodomain gene, in the rat brain.

We examined the distribution of Rlim, a homologue to Xlim-1, in the rat brain. Rlim, a LIM class homeodomain gene, was isolated from rat brain, and localized in the adult brain by in situ hybridization histochemistry. The expression of Rlim was found in discrete regions, such as the Purkinje cell layer of the cerebellum and several nuclei of the hypothalamus, midbrain and pons. This suggests that Rlim is related to regulation of genes that are specific to some neurons such as Purkinje cells in the adult.

Amino Acid Sequence↗
PubMed1994

Newly discovered photodegradation products of nifedipine in hospital prescriptions.

New photodegradation products of nifedipine (1) have been isolated. They were found in tablets dispensed in the pulverized form by hospitals. 1 decomposed concurrently into six components after storage of 30 days under exposure to normal room light. The main photoproduct was a nitroso derivative (2) and others were minor. Preparative thin-layer chromatography has been used to isolate the six photodegradation products. The chemical structures of these isolated compounds were identified or estimated by comparison with authentic samples and/or using UV, IR, 1H NMR, mass spectroscopy, melting point determination, and elementary analysis. From these analyses, it was found that 1 was converted into a cis-azoxy derivative (4), a trans-azoxy derivative (5), a N,N'-dioxide derivative (6) and a lactam derivative (7) in addition to 2 and a nitro derivative (3). Furthermore, it is proposed that 2 is mainly responsible for the formation of these new products (4-7) by photochemical condensation.

Chromatography, High Pressure Liquid↗
PubMed1994

Distinct regulation of sodium channel types I, II and III following nerve transection.

We investigated mRNA expression of type I, II and III voltage-sensitive sodium channels in motoneurons following facial nerve transection by means of in situ hybridization histochemistry. Type I mRNA expression decreased markedly after nerve transection, while that of type III increased. Type II expression underwent no detectable change following nerve transection. These results suggest that type III sodium channels may be involved in regeneration and plasticity.

Animals↗
PubMed1994

Localization of 63-kDa calmodulin-stimulated phosphodiesterase mRNA in the rat brain by in situ hybridization histochemistry.

We studied the localization of 63-kDa Ca2+/calmodulin stimulated phosphodiesterase mRNA in the rat brain by in situ hybridization histochemistry using an oligonucleotides probe specific to this enzyme. The signals were especially concentrated in several brain regions such as the olfactory tubercle, accumbens nucleus, caudate putamen, fundus striati, dentate gyrus of the hippocampus, pontine nuclei and dorsal tegmental nucleus. These results suggest that in the neuronal groups containing the strong signals this enzyme is involved in calcium-dependent signal transduction system coupled to cyclic nucleotides messenger systems.

Animals↗
PubMed1994

Development of an effective and simple insemination method for the in vitro fertilization of patients with male-factor infertility.

An insemination method involving mechanical removal of the cumulus and multiple oocytes per dish (MRC-MOPD) was applied to achieve in vitro fertilization (IVF) of patients with male-factor infertility, and the prognosis of IVF and embryo transfer was evaluated. Although the fertilization rate of patients with male-factor infertility was only 41.4% (12/29) using standard insemination methods, a 73.0% (27/37) fertilization rate was achieved with the MRC-MOPD method. Moreover, 10 patients with male-factor infertility who were treated with the MRC-COPD method achieved clinical pregnancy. A comparison of the results in the 10 patients who were treated with both methods in common reveals that the MRC-MOPD method also increased the fertilization rate per oocyte. The rate of occurrence of polyploid fertilization did not increase, although large numbers of sperm were inseminated via the MRC-MOPD method. These results indicate that the MRC-MOPD method is an effective and simple insemination technique to achieve successful IVF of patients with male-factor infertility.

Embryo Transfer↗
PubMed1993

Neuropeptide Y innervation in the spinal nucleus of bulbocavernosus of the rat.

Immunoelectron microscopy combined with a retrograde tracing technique was carried out to examine the synaptic interaction between neuropeptide Y (NPY)-like immunoreactive (LI) axon terminals and spinal motoneurons innervating bulbocavernosus muscles. Cell bodies and proximal dendrites of these motoneurons were frequently found to receive synaptic inputs from NPY-LI axon terminals.

Animals↗
PubMed1993

Substance P-immunoreactive astrocytes in gracile sensory nervous tract of spinal cord in gracile axonal dystrophy mutant mouse.

In the gracile axonal dystrophy (GAD) mutant mouse, the dying-back type axonal dystrophy of the primary afferent neurons in the gracile tract of the spinal cord was marked by severe gliosis characterized by the hypertrophy and proliferation of the fibrous astrocytes. Immunocytochemical observation for substance P (SP) revealed that SP-positive cells increased in the lesioned sites, primarily in the gracile nucleus of the medulla and subsequently in the gracile fasciculus of the spinal cord. The combined immunostaining of both SP and glial fibrillary acidic protein (GFAP) indicated that a strong correspondence exists between GFAP-positive networks and SP-positive grains, suggesting that SP was accumulated in the cytoplasm of astrocytes. The networks of SP-positive astrocytes spread all over the gracile tract and were densest at the subpial membrane. Similar lesions and SP activity were detected along the marginal zone of the lateral and ventral funiculi. Using an electron microscope, in addition to SP-positive axonal terminals in the gracile nucleus, most SP-positive cells in the gracile tract were identified as reactive astrocytes whose processes surrounded myelinated and nonmyelinated axons, and extended their foot processes to the blood vessels. By in situ hybridization histochemistry of SP mRNA, we confirmed the synthesis of SP in the astrocytes. Although the functional significance of SP within astrocytes is not established here, these results imply that the astrocytes may play a role as a gliotransmitter through which the progress of axonal degeneration in the spinal cord was modified.

Animals↗