Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 361 records · Page 20Linked to original sources

PubMed2000

Conversion to docosahexaenoic acid-containing phosphatidylserine from squid skin lecithin by phospholipase D-mediated transphosphatidylation.

Phospholipase D (PLD)-mediated transphosphatidylation of squid skin lecithin with L-serine was examined to prepare docosahexaenoic acid-containing phosphatidylserine (DHA-PS). When a biphasic system with organic solvent and 0.2 M acetate buffer (pH 5.5) was used, PS synthesis was significantly affected by the amount of 3.4 M L-serine-containing acetate buffer. L-Serine concentration in the acetate buffer and choice of organic solvent were also crucial. In a typical reaction with 0.8 unit of PLD (Streptomyces sp.), 2.5 mL of ethyl acetate substrate solution containing 30 mg of squid skin lecithin in combination with 3 mL of 3.4 M L-serine-containing 0.2 M acetate buffer (pH 5.5), PS content in the recovered phospholipid fraction increased to 43.1% after 24 h. DHA composed 37.6% of fatty acids in the converted PS. This was the same DHA level as in the substrate. Phosphatidylcholine (squid skin PC, DHA 44.2%) in the squid skin lecithin was more effectively converted to PS than phosphatidylethanolamine.

Animals↗

PubMed2000

An FTIR study on the structure of the oxygen-evolving Mn-cluster of Photosystem II in different spin forms of the S(2) state.

The S(2) state of the oxygen-evolving Mn-cluster of Photosystem II (PS II) is known to have different forms that exhibit the g =2 multiline and g = 4.1 EPR signals. These two spin forms are interconvertible at > 200 K and the relative amplitudes of the two signals are dependent on the species of cryoprotectant and alcohol contained in the medium. Also, it was recently found that the mutiline form can be converted to the g = 4.1 form by absorption of near-infrared light by the Mn-cluster itself at around 150 K [Boussac et al. (1996) Biochemistry 35: 6984-6989]. We have used light-induced Fourier transform infrared (FTIR) difference spectroscopy to study the structural difference in these two S(2) forms. FTIR difference spectra for S(2)/S(1) as well as for S(2)Q(A) (-)/S(1)Q(A) measured at cryogenic temperatures using PS II membranes in the presence of various cryoprotectants, and monohydric alcohols did not show any specific differences except for intensities of amide I bands, which were larger when ethylene glycol or glycerol was present in addition to sucrose. This result was interpreted due to more flexible movement of the protein backbones upon S(2) formation with a higher cryoprotectant content. Light-induced difference spectra measured at 150 K using either blue light without near-infrared light or red plus near-infrared light also did not show any detectable difference. In addition, a different spectrum upon near-infrared illumination at 150 K of the PS II sample in which the S(2) state had been photogenerated at 200 K exhibited no meaningful signals. These results indicate that the two S(2) forms that give rise to the multiline and g = 4.1 signals have only minor differences, if any, in the structures of amino-acid ligands and polypeptide backbones. This conclusion suggests that conversion between the two spin states is caused by a spin-state transition in the Mn(III) ion rather than valence swapping within the Mn-cluster that would considerably affect the vibrations of ligands.

Journal Article↗

PubMed2000

Characterization of chloroplast psbA transformants of Chlamydomonas reinhardtii with impaired processing of a precursor of a photosystem II reaction center protein, D1.

One of the photosystem II reaction center proteins, D1, is encoded by the psbA gene and is synthesized as a precursor form with a carboxyl-terminal extension that is subsequently cleaved between Ala-344 and Ser-345. We have generated three psbA transformants of the green alga Chlamydomonas reinhardtii in which Ala-344 or Ser-345 have been substituted with Pro or Glu (A344P, S345E, and S345P) to understand the effects of the amino acid substitutions on the processing of the precursor D1. S345E grew photoautotrophically and showed PSII activity like the wild type. However, A344P and S345P were unable to grow photoautotrophically and were significantly photosensitive. A344P was deficient in the processing of precursor D1 and in oxygen-evolving activity, but assembled photosystem II complex capable of charge separation. In contrast, both precursor and mature forms of D1 accumulated in S345P cells from the logarithmic phase and the cells evolved oxygen at 18% of wild-type level. However, S345P cells from the stationary phase contained mostly the mature D1 and showed a twofold increase in oxygen-evolving activity. The rate of processing of the accumulated pD1 was estimated to be about 100 times slower than in the wild type. It is therefore concluded that the functional oxygen-evolving complex is assembled when the precursor D1 is processed, albeit at a very low rate. These results suggest the functional significance of the amino acid residues at the processing site of the precursor D1.

Amino Acid Substitution↗

PubMed2000

A monoclonal antibody stains radial glia in the adult zebrafish (Danio rerio) CNS.

We have prepared a monoclonal antibody, denoted as C-4, which specifically recognizes astroglia with radial forms in the adult zebrafish brain. This report suggests that there are at least two different types of astroglia in the mature teleost brain, only one of which is recognized by C-4. Further, we have found that the C-4-binding astroglia are comprised of three morphologically distinct cellular types. Immunoblot analysis revealed that the antibody recognized only one protein band of approximately 30 kDa in the membrane fraction of the adult zebrafish brain. In the spinal cord, stained glial cells appeared to occur in the same location as ependymocytes. The processes and cell bodies of extra-ependymal cells, many adjacent to ependymocytes and a few near the pial surface, were also stained by the antibody. In the cerebellum, long processes stained by C-4 were found in the molecular layer, and these connected the cerebellum surface to the Purkinje-like cell layer. Long processes were also stained in the mesencephalon, but these were thicker than those in the spinal cord and they linked the two ventricles. The optic tectum, olfactory bulb and cranial nerves, including the optic nerves, were, however, completely devoid of the C-4 antigen. Double-immunofluorescence with antibodies against glial fibrillary acidic protein (GFAP) and C-4 demonstrated that C-4-positive cells were also GFAP-positive, although there was also a subset of GFAP-positive cells which were C-4-negative. The C-4 antibody is thus a useful tool for studying subtypes of GFAP-positive astroglia.

Age Factors↗

PubMed2000

Involvement of CYP3A4 in the metabolism of bromperidol in vitro.

In this study, human cytochrome P450 isoenzymes (CYP1A2, CYP2C19, CYP2D6, and CYP3A4) expressed in a cell line were used to elucidate their roles in the metabolism of bromperidol. We found that CYP3A4 catalyzes the N-dealkylation of bromperidol and its metabolite, reduced bromperidol. CYP3A4 also catalyzes the dehydration of bromperidol to bromperidol 1,2,3,6-tetrahydropyridine, metabolizes bromperidol to bromperidol pyridinium, and catalyzes the oxidation of reduced bromperidol back to bromperidol. CYP1A2, CYP2C19, and CYP2D6 do not catalyze these reactions.

Aryl Hydrocarbon Hydroxylases↗

PubMed2000

Immunologic 'ignorance' of vascularized organ transplants in the absence of secondary lymphoid tissue.

Secondary lymphoid organs (the spleen, lymph nodes and mucosal lymphoid tissues) provide the proper environment for antigen-presenting cells to interact with and activate naive T and B lymphocytes. Although it is generally accepted that secondary lymphoid organs are essential for initiating immune responses to microbial antigens and to skin allografts, the prevailing view has been that the immune response to primarily vascularized organ transplants such as hearts and kidneys does not require the presence of secondary lymphoid tissue. The assumption has been that the immune response to such organs is initiated in the graft itself when recipient lymphocytes encounter foreign histocompatibility antigens presented by the graft's endothelial cells. In contrast to this view, we show here that cardiac allografts are accepted indefinitely in recipient mice that lack secondary lymphoid tissue, indicating that the alloimmune response to a vascularized organ transplant cannot be initiated in the graft itself. Moreover, we demonstrate that the permanent acceptance of these grafts is not due to tolerance but is because of immunologic 'ignorance'.

Animals↗

PubMed2000

Macular corneal dystrophy type I and type II are caused by distinct mutations in a new sulphotransferase gene.

Macular corneal dystrophy (MCD; MIM 217800) is an autosomal recessive hereditary disease in which progressive punctate opacities in the cornea result in bilateral loss of vision, eventually necessitating corneal transplantation. MCD is classified into two subtypes, type I and type II, defined by the respective absence and presence of sulphated keratan sulphate in the patient serum, although both types have clinically indistinguishable phenotypes. The gene responsible for MCD type I has been mapped to chromosome 16q22, and that responsible for MCD type II may involve the same locus. Here we identify a new carbohydrate sulphotransferase gene (CHST6), encoding an enzyme designated corneal N-acetylglucosamine-6-sulphotransferase (C-GlcNAc6ST), within the critical region of MCD type I. In MCD type I, we identified several mutations that may lead to inactivation of C-GlcNAc6ST within the coding region of CHST6. In MCD type II, we found large deletions and/or replacements caused by homologous recombination in the upstream region of CHST6. In situ hybridization analysis did not detect CHST6 transcripts in corneal epithelium in an MCD type II patient, suggesting that the mutations found in type II lead to loss of cornea-specific expression of CHST6.

Amino Acid Sequence↗

PubMed2000

Suppression of arterial intimal hyperplasia by cilostamide, a cyclic nucleotide phosphodiesterase 3 inhibitor, in a rat balloon double-injury model.

The effects of cilostamide, a cyclic nucleotide phosphodiesterase 3 (PDE3) selective inhibitor, on vascular intimal hyperplasia were evaluated using a single-balloon injury model and a double-injury model in which the rat common carotid artery was subjected to a second injury at a site injured 14 days previously. In the double-injury model, the second balloon injury caused more severe intimal hyperplasia (intima/media (IM) ratio, 1.88+/-0.10) than in the single-injury model (1.09+/-0.08). Histopathological study revealed that vascular smooth muscle cells (VSMC) were the predominant cell-type in the affected neointimal area. Oral administration of cilostamide for 2 weeks after the second injury suppressed intimal hyperplasia in the double-injury model (30 mg kg(-1) bid, 83% inhibition in terms of the IM ratio, P<0.05; 100 mg kg(-1) bid, 69% inhibition, P<0.05). Similar effects were also observed in the single-injury model with oral administration of cilostamide for 2 weeks (100 mg kg(-1) bid, 36% inhibition, P<0.01). Cilostamide inhibited DNA synthesis of cultured VSMC stimulated by foetal calf serum or different kinds of growth factors, but did not affect their migration stimulated by platelet-derived growth factor (PDGF)-BB. Cilostamide significantly increased the cyclic AMP concentration of VSMC dose-dependently. These results indicate that cilostamide suppresses intimal hyperplasia both in the single- and double-injury models of rat, presumably by inhibiting proliferation rather than migration of VSMC. It is suggested that PDE3 inhibitors might find application in preventing intimal hyperplasia following angioplasty such as percutaneous transluminal coronary angioplasty (PTCA) or stent.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed2000

Nail bed keratinocytes express an antigen of the carcinoembryonic antigen family.

Using a panel of monoclonal and polyclonal antibodies raised against human carcinoembryonic antigen (CEA) and CEA-related molecules, we detected strong expression of an antigen, with immunoreactivity consistent with non-specific cross-reacting antigen (NCA) (CD66c), in all of 26 normal human nail specimens obtained from various fingers and toes. In longitudinal sections, strong and constant expression of the NCA-like antigen was seen on keratinocytes distributed in the upper epithelial cell layers of the nail bed, while in transverse sections the expression was limited to the major central portions of the nail bed, but only where longitudinal epidermal ridges were observed. In the hyponychium and the ventral aspect of the proximal nail fold, the expression was weak or lacking. No expression was seen in the nail matrix, the nail plate, or the dorsal aspect of the proximal nail fold. The same results were obtained for all of the 26 nails studied. This report is the first to demonstrate that an antigen of the CEA family, with NCA-like immunoreactivity, is expressed in a specific subpopulation of keratinocytes in the nail bed. The specific expression pattern suggests that the antigen may play a part in adhesion of the nail plate to the nail bed.

Aged↗

PubMed2000

Preferential potentiation by nitric oxide of spontaneous inhibitory postsynaptic currents in rat supraoptic neurones.

Magnocellular neurones in the supraoptic nucleus and paraventricular nucleus express mRNA for nitric oxide synthase (NOS) and the expression becomes more prominent when the release of vasopressin or oxytocin is stimulated. It has also been reported that NO donors inhibit the electrical activity of supraoptic nucleus neurones, but the mechanism involved in the inhibition remains unclear. In the present study, to know whether modulation of synaptic inputs into supraoptic neurones is involved in the inhibitory effect of NO, we measured spontaneous excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) from rat supraoptic nucleus neurones in slice preparations identified under a microscope using the whole-cell mode of the slice-patch-clamp technique. The NO donor, S-nitroso-N-acetylpenicillamine (SNAP), reversibly increased the frequency of spontaneous IPSCs mediated by GABAA receptors, without affecting the amplitude, indicating that NO potentiated IPSCs via a presynaptic mechanism. The NO scavenger, haemoglobin, suppressed the potentiation of IPSCs by SNAP. On the other hand, SNAP did not cause significant effects on EPSCs mediated by non-NMDA glutamate receptors. The membrane permeable analogue of cGMP, 8-bromo cGMP, caused a significant reduction in the frequency and amplitude of both IPSCs and EPSCs. The results suggest that NO preferentially potentiates the inhibitory synaptic inputs into supraoptic nucleus neurones by acting on GABA terminals in the supraoptic nucleus, possibly via a cGMP-independent mechanism. The potentiation may, at least in part, account for the inhibitory action of NO on the neural activity of supraoptic neurones.

Animals↗

PubMed2000

Sleep problems in Japanese industrial workers.

In order to investigate the prevalence of a disordered condition due to shift work (DCSW) and the influence of sleep disorders on the performance of working and driving, a preliminary questionnaire was conducted on industrial workers. Among 332 shift workers, 110 (33.1%) were found to suffer from DCSW. Subjects with DCSW were found to be working shorter periods in shift work than were subjects without DCSW. The rate of sleepiness-related troubles while driving and working were highest in the subjects with probable hypersomnia. This finding encourages the need for early diagnosis and treatment of sleep disorders among industrial workers.

Adult↗

PubMed2000

Relationship between hypersomnia and respiratory disorder during sleep in Prader-Willi syndrome.

To assess whether hypersomnia in Prader-Willi syndrome (PWS) patients is related to the respiratory disorder during sleep (RDDS), we made a systematic evaluation regarding the relationship between the two disorders in three patients. All patients showed hypersomnia manifested as the long duration of night sleep and shortened sleep latencies of multiple sleep latency test. Although magnetic resonance imaging and laboratory studies revealed obstruction of the upper airway and mild increase of esophageal pressure during sleep, the number of other apneic episodes or awakenings was not as frequent. From the above results, we speculate that the mechanism of excessive daytime sleepiness in PWS is not caused by RDDS and quite resembles that of essential hypersomnia.

Adolescent↗

PubMed2000

Clinical significance of negative esophageal pressure in sleep apnea syndrome.

The authors investigated the relationship between esophageal pressure fluctuation (DPes) during sleep and the following parameters: respiratory disorder variables and daytime sleepiness manifested as the Epworth sleepiness scale (ESS). In the younger patient group under 60 years of age (n=33), DPes was correlative to both the apnea-hypopnea index and ESS. However, in the elderly group of 60 years and over (n = 16), the variables showed smaller values than did those in the younger group. These results suggest that DPes may be associated with the aggravating process of sleep apnea syndrome (SAS) in the younger patient.

Adult↗

PubMed2000

Case of a mentally retarded child with non-24 hour sleep-wake syndrome caused by deficiency of melatonin secretion.

A case of a 5-year-old boy with non-24 hour sleep-wake syndrome and mental retardation is reported. His free-running sleep-wake rhythm was remarkably improved by the oral administration of melatonin. The circadian variation in melatonin secretion was extremely low, and circadian rhythm of cortisol secretion was noted. It was speculated that his non-24 hour sleep-wake syndrome was due to a congenital deficiency of melatonin secretion, and supplemental melatonin therapy proved effective for treating his condition.

Administration, Oral↗

PubMed2000

A case report of comorbid eating disorder and factitious disorder.

A review of the literature on comorbid eating disorder and factitious disorder reveals that they are very rare. In this report the authors present the case of a 26-year-old Japanese female, who, in the midst of treatment for eating disorder, was found to be fabricating her physical symptoms, by injecting unclean water into her intravenous bottle. As a result she was diagnosed with factitious disorder.

Adult↗

PubMed2000

Effects of NO-1886, a lipoprotein lipase promoting agent, on homozygous and heterozygous Watanabe heritable hyperlipidaemic rabbits.

The novel compound NO-1886 ([4-(4-bromo-2-cyano-phenylcarbamoyl)-benzyl]-phosphonic acid diethyl ester, CAS 133208-93-2) is a lipoprotein lipase (LPL) activator, and long term administration of NO-1886 protects against the development of experimental atherosclerosis in rats and rabbits. In the present experiments, the effects of this compound were examined in Watanabe heritable hyperlipidaemic (WHHL) rabbits, an animal model for familial hypercholesterolemia lacking low density lipoprotein (LDL) receptors. NO-1886 increased postheparin plasma LPL activity, resulting in a reduction of plasma triglycerides with concomitant elevation of HDL cholesterol in heterozygous WHHL rabbits. However, the compound did not cause any changes in plasma lipids and postheparin plasma LPL activity in homozygous WHHL rabbits. The different responses suggest that the effects of NO-1886 may be either mediated by LDL receptors, or that persistent exposure to extreme hypercholesterolemia might affect the cellular response to this particular compound in homozygous WHHL rabbits.

Animals↗

PubMed2000

Use of the ultrasonically activated scalpel in acoustic neuroma surgery: preliminary report.

Recently, the ultrasonic activated scalpel (the Harmonic Scalpel, HS) has been introduced in laparoscopic surgery. We have applied the HS in debulking the tumor in the posterior fossa and concluded that this is useful in acoustic neuroma surgery. Fifteen patients with a tumor extending more than 20 mm into the posterior fossa were included in this study. The extended middle cranial fossa approach type II was used in 13 patients and type III (hearing preservation surgery) was used in 2 patients. In one of two patients, hearing was preserved. Postroperative facial nerve function according to the House-Brackmann method was grade I in 12 patients, grade II in 2 patients, and grade III in 1 patient. Compating the technique of using HS to a pair of bipolar forceps and/or ultrasonic cavitational aspirator, the former can result in better preservation of the facial nerve function.

Journal Article↗

PubMed2000

Surgical treatment for epidural abscess in the posterior cranial fossa using trapezius muscle or musculocutaneous flap.

Two patients developed an epidural abscess in the posterior cranial fossa following tumor dissection from the occipital region of the head and underwent surgical treatment. After debridement of necrotic and infectious tissues inside the abscess was performed, the empty cavity was filled and the tissue defect was reconstructed by using a trapezius muscle flap or a trapezius musculocutaneous flap. Both patients had good clinical results, and their abscesses were healed. The trapezius muscle flap and trapezius musculocutaneous flap were quite useful in the treatment for epidural abscess in the posterior cranial fossa.

Journal Article↗