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S Yamagami

Publications and source records attributed to S Yamagami.

At least 73 records · Page 4Linked to original sources
PubMed1997

Effects of fluvoxamine on food intake during rebound hyperphagia in rats.

We examined the effects of fluvoxamine on food intake during rebound hyperphagia induced by a time-restricted feeding schedule in rats. Rats were allowed access to food for only 2 h daily for 7 days, and then had free access to food for 7 consecutive days. The daily food intake of the rats was dramatically increased, by 42.5% (rebound hyperphagia), for 7 days of the free-feeding period. Intraperitoneal injection of fluvoxamine decreased food intake significantly in a dose-dependent manner for the first 3 h of feeding during 7 days. When rats were allowed access to one of the standard, carbohydrate-, fat-, or protein-rich diets in the free-feeding period following the time-restricted feeding schedule, fluvoxamine significantly decreased food intakes of standard, carbohydrate- and fat-rich diets on all days, and the protein-rich diet after the 2nd day of the free-feeding period. These results indicate that fluvoxamine, irrespective of the diet composition, suppresses rebound hyperphagia induced by a time-restricted feeding schedule, but that its effect is short-lived.

Animals↗
PubMed1997

Bromocriptine enhances feeding behavior without changing dopamine metabolism.

Bromocriptine is an ergot derivative and has been thought to act as a selective D2 receptor agonist, but its effects on dopamine release in vivo have not been confirmed. We administered bromocriptine into the striatum of rats and studied the effects on feeding behavior and dopamine release. Bromocriptine was perfused via a microdialysis probe into the ventrolateral striatum of rats fasted for 22 h, and the rats were then allowed to feed freely for 6 h. Bromocriptine perfusion increased food intake in a dose-dependent manner, whereas the extracellular concentrations of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) did not change. Perfusion of (-) sulpiride, a selective D2 receptor antagonist, decreased food intake, but increased dopamine release and the levels of DOPAC and HVA. Pretreatment with (-)sulpiride perfusion for 1 h prior to bromocriptine perfusion inhibited the increase of food intake induced by bromocriptine, and it increased dopamine release and the levels of DOPAC and HVA. These findings suggest that bromocriptine directly perfused into the ventrolateral striatum acts selectively on postsynaptic D2 receptors and enhances feeding behavior.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1997

The comparative effects of haloperidol, (-)-sulpiride, and SCH23390 on c-fos and c-jun mRNA expressions, and AP-1 DNA binding activity.

The c-fos and c-jun mRNA expressions were measured by the RNase protection assay method following intraperitoneal injection of haloperidol, (D1 and D2 receptor antagonists), (-)-sulpiride, (D2 receptor antagonist), and SCH23390, (D1 receptor antagonist). Haloperidol and (-)-sulpiride increased their mRNA expressions in a dose-dependent manner, peaking at 30 min after injection followed by a gradual decline. The SCH23390 did not induce expression of either c-fos or c-jun mRNA. A significant decrease of c-fos as well as c-jun mRNA expression was found due to pretreatment with SCH23390 (1 mg/kg i.p.) followed by injection of (-)-sulpiride (20 mg/kg i.p.). The results suggest that the expression of these mRNAs is closely related to the dopamine D2-like antagonism. Administration of haloperidol or (-)-sulpiride increased AP-1 DNA binding activity with similar manner of dose-dependence, whereas their activities were reduced by Fos and Jun antibodies, implying that AP-1 components, transcriptional factors, forming due to Fos and Jun were actually activated by either haloperidol or (-)-sulpiride.

Animals↗
PubMed1997

Nuclear polyadenylate polymerase activity in the brain of seizure-prone EL mice.

Nuclear polyadenylate polymerase from I activity in the brains of seizure-prone EL mice was significantly higher than in seizure-non-susceptible progenitor ddY mice. This finding may be essential in acquiring susceptibility to seizures, since there was no significant difference between EL(S) mice and those that did not receive stimulation, EL(NS) mice. Lower form II enzymatic activity was observed in both groups of EL mice but not in ddY mice. Moreover, significantly lower activities of form II 7 days after seizures were found in EL(S) mice compared with EL(NS) mice, suggesting that this is a consequence of repeated seizures. The activity of form I enzyme decreased immediately and at 30 and 60 min after seizures, then returned to control levels at 100 min. Form II enzymatic activity was significantly decreased only at 30 min after seizures, implying that seizures exerted a later effect on form II enzyme. These changes may cause a decrease in the rate of polyadenylation in the brain; thus, alteration of post-transcriptional events, including messenger RNA processing and transport, may occur during epileptic seizures.

Animals↗
PubMed1997

Production of hepatocyte growth factor is increased in chronic renal failure.

Hepatocyte growth factor (HGF) facilitates recovery from tissue injuries. We previously reported that serum HGF levels were elevated in chronic renal failure (CRF) patients. In the present study Western blot analysis of CRF patients' sera showed the majority of their serum HGF was a single-chain precursor molecule. In CRF rats developed by 5/6 nephrectomy or high adenine diet, both HGF mRNA expression levels and tissue HGF concentrations were increased in liver and spleen. The results suggest that HGF production increases in CRF, which may be a response to chronic progressive renal injuries in an endocrine manner.

Adult↗
PubMed1997

Detection of peptidoglycan and endotoxin in dialysate, using silkworm larvae plasma and limulus amebocyte lysate methods.

Silkworm larvae plasma (SLP) reagent is activated by peptidoglycan (PG), a fragment of both the gram-positive and gram-negative bacterial cell wall, as well as beta-glucan (BG), a component of fungi. It is possible to measure contamination of gram-positive bacteria quantitatively by combining the conventional limulus amebocyte lysate (LAL) and PG measurement methods. Therefore, a more highly accurate analysis of dialysate can be made using both SLP and LAL methods to detect endotoxin (ET) and/or PG contamination. We studied the effects of contaminated dialysate on human peripheral blood mononuclear cells (PBMC) by producing various cytokines in vitro. Muramyl dipeptide (MDP) was used as the biologically active minimum constituent of PG. A total of 54 dialysate samples were obtained under sterile conditions from 4 sites: (1) reverse osmosis water unit; (2) proportioning unit; (3) multiple dialysate preparation console, and (4) personal dialysate preparation console, at 9 dialysis facilities. To detect bacterial contamination, the samples were measured with LAL(C), LAL(G) and SLP methods. PBMC were collected from 10 healthy controls and from 10 hemodialysis patients and cultured for 24 h with ET, MDP, ET + MDP and contaminated dialysate. IL-1 receptor antagonist (IL-1Ra), IL-1 beta and TNF-alpha in the culture medium supernatants were measured using the ELISA method. PG was not detected in dialysate from sites 1 or 2. However, dialysate from the inlet of the dialyzer at the bedside monitor of the central supply and personal console showed 4.1 +/- 6.1 ng/ml for site 3 (in 7 of 18 samples) and 3.3 +/- 4.6 ng/ml for site 4 (in 3 of 18 samples). Contamination by PG alone and complex contamination by PG and ET were also detected. Furthermore, IL-1Ra, IL-1 beta and TNF-alpha production by PBMC increased in accordance with the concentrations of MDP. Cytokine production was enhanced 5-10 times more where MDP and ET coexisted than where either MDP or ET existed alone, showing the synergic effects of MDP and ET. Based on these results, there is a high possibility that PG may also be a pyrogen in the dialysate prior to this study. ET had been considered the only pyrogen in dialysate. Therefore, it is essential to recognize the existence of both ET and PG in investigating dialysate contamination.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1997

Regional cerebral blood flow and glucose utilization in spontaneously epileptic EL mice.

UNLABELLED: The dynamics of the relative regional cerebral blood flow (rCBF) and regional glucose utilization (rGU) were examined in spontaneously epileptic EL mice in the interictal, ictal and postictal states, using autoradiography with 125I-N-isopropyl-p-iodoamphetamine (IMP) and 14C-2-deoxyglucose (DG), respectively. METHODS: EL mice were used in the study, which have previously been used as a model of the idiopathic human epilepsy. EL mice develop secondary generalized tonic-clonic convulsions, and ddY and EL(o) mice, which do not experience seizures, were used as controls. IMP and DG, respectively, were injected in EL mice in the interictal, ictal and postictal states. We examined the relative rCBF and rGU from the obtained autoradiograms of mouse brain sections. RESULTS: No significant changes in the relative rCBF were obtained in the hippocampus in the course of epileptic seizures. In contrast, significant increases in the relative rGU were observed in the hippocampus in the ictal and early postictal states. The dissociation between the dynamics of the rCBF and rGU were found in the event of epileptic seizures of EL mice. CONCLUSION: The flow metabolism dissociation in the ictal and early postictal states is of both conceptual and practical interest, while the reason for the dissociation of rCBF from the rGU in epileptics seizures remains to be established. Our results emphasize the importance of estimating both cerebral perfusion and glucose metabolism in epilepsy.

Amphetamines↗
PubMed1997

Risk factors for unsatisfactory intraocular pressure control in combined trabeculectomy and cataract surgery.

BACKGROUND AND OBJECTIVE: Trabeculectomy combined with posterior chamber intraocular lens (PC IOL) insertion is often chosen for the treatment of glaucoma combined with cataract. In this study, the clinical prognostic indicators for late intraocular pressure (IOP) control in combined procedures were investigated. PATIENTS AND METHODS: The clinical records of 60 eyes that underwent trabeculectomy combined with PC IOL implantation were retrospectively analyzed using the Cox proportional hazards model. All of the patients received postoperative 5-fluorouracil injections. RESULTS: Extracapsular cataract extraction (ECCE) was found to be a statistically significant risk factor for unsatisfactory late IOP control (hazard ratio 2.54; P < .01) and for unsatisfactory filtering bleb appearance (hazard ratio 5; P < .001). The frequency of fibrin formation and the incidence of a transient IOP spike (> or = 25 mm Hg) were significantly lower in the phacoemulsification and aspiration (PEA) group than in the ECCE group. In the PEA group, the probability of IOP control (< or = 15 mm Hg) without medication was 54%, and the probability of persistent filtering bleb appearance was 80% at 18 months. CONCLUSION: The PEA technique, not ECCE, should be employed in combined trabeculectomy and PC IOL implantation.

Aged↗
PubMed1996

Plasma neuropeptide Y in patients with major depressive disorder.

It has been suggested that neuropeptide Y (NPY) is involved in the pathophysiology of depression. Plasma peptide-rich fraction from patients with major depressive disorder and control subjects was eluted with high performance liquid chromatography (HPLC), followed by radioimmunoassay of NPY. The screening patterns of the NPY-like immunoreactivity in 50 fractions eluted by HPLC from the plasma peptide-rich fraction were different between the two groups. The values of NPY in the 16 controls and the 14 patients were 427 +/- 38 and 310 +/- 27 fmol/ml plasma (P < 0.05), respectively. These results suggest that impaired metabolism of plasma NPY and the reduced plasma NPY in patients with major depressive disorder could be involved in the pathogenesis or pathophysiology of major depressive disorder.

Adult↗
PubMed1996

Expression of calbindin-D28K by reactive astrocytes in gerbil hippocampus after ischaemia.

Calbindin-D28K (Calbindin) is a member of the superfamily of calcium-binding proteins that is implicated in the regulation of intracellular calcium. In the adult mammalian brain, calbindin was thought to be present only in neurones, where it is believed to serve a neuroprotective role. We now report the expression of calbindin after ischaemia in reactive astrocytes in the CA1 subfield of the hippocampus. Since other calcium-binding proteins, such as S-100 and calmodulin, which induce transformation or proliferation of glia, occur in astrocytes, it is conceivable that the expression of calbindin after ischaemia might be an important part of the process of gliosis.

Animals↗
PubMed1996

The role of cell adhesion molecules in allograft rejection after penetrating keratoplasty in mice. Clinical and immunohistochemical study.

BACKGROUND: It has been reported that adhesion molecules play an important role in immunological rejection after organ transplantation. In the present study, we examined the role of ICAM-1/ LFA-1 adhesion molecules in corneal allograft rejection and evaluated the immunological specificity of monoclonal antibodies (mAbs) in preventing allograft rejection in mice. METHODS: The allografted mice were intraperitoneally injected with 100 micrograms/day of the following mAbs: a control mAb, anti-ICAM-1 mAb, anti-LFA-1 mAb, or a mixture of anti-ICAM-1 and anti-LFA-1 mAbs from 1 day before to 7 days after surgery. The expression of ICAM-1 and LFA-1 molecules in the grafted cornea was studied immunohistochemically. The corneas from a syngeneic donor or a third-party strain were transplanted 4 weeks after the initial keratoplasty onto the mice treated with both anti-ICAM-1 and anti-LFA-1 mAbs. RESULTS: The allografts treated with anti-LFA-1 mAb alone or both anti-ICAM-1 and anti-LFA-1 mAbs remained transparent for more than 2 weeks, and the survival rate at 8 weeks was 40% in both groups. ICAM-1 was expressed on the mononuclear cells, keratocytes and endothelial cells in the allografts without treatment. The second corneal grafts syngeneic to the initial donor remained transparent at 2 weeks, whereas those from the third party were rejected. CONCLUSIONS: ICAM-1 and LFA-1 adhesion molecules play a crucial role in the pathophysiology of corneal transplant rejection. The immunosuppressive effects of anti-ICAM-1 and anti-LFA-1 mAbs are highly allospecific. The administration of mAbs to the adhesion molecules represents a new means of suppressing allograft rejection after penetrating keratoplasty.

Animals↗
PubMed1996

A chronological study of the expression of glial fibrillary acidic protein and calbindin-D28 k by reactive astrocytes in the electrically lesioned rat brain.

Immunoreactivity of neuronal and glial marker proteins of reactive astrocytes around the electrically damaged pyramidal layer and stratum radiatum of the hippocampal CA1 region and corpus callosum was chronologically studied in electrically lesioned rat brains. A monoclonal antibody against calbindin-D28 k (CD28-Ab) and a polyclonal antibody against glial fibrillary acidic protein (GFAP-Ab) were used for immunostaining. Immunoreactivity of CD28 and GFAP in the reactive astrocytes was detected in brains 1-6 weeks post-lesion but not in non-lesioned brains. The number of immunohistochemically stained reactive astrocytes around the electrically damaged areas were counted and then compared with the number of those in the same areas of non-lesioned brains. The number of CD28- and GFAP-immunoreactive astrocytes began to increase around the lesion from 1-3 weeks following lesion in the pyramidal layer of the hippocampal CA1 region and from 1-4 weeks following lesion in the stratum radiatum of the hippocampal CA1 region and corpus callosum. These immunoreactive astrocytes could be observed for 6 weeks (the maximum survival time studies) in all areas of the lesioned brains studied. The increase in the number of reactive astrocytes might have been induced by the stimulatory effects of neurotrophic factors, or growth factors, produced around the lesioned site. The constancy in the number of reactive astrocytes after 3 and 4 weeks in the lesioned areas may have been due to the termination of the initial phase of the repair process, i.e. space-filling. Reactive astrocytes which were stained by GFAP-Ab were separated into two groups, based on the presence of CD28, i.e. CD28-positive and CD28-negative reactive astrocytes. The presence of CD28 might confer certain functions via calcium-mediated mechanisms on CD28-positive astrocytes in addition to the constructive role mediated by GFAP.

Animals↗
PubMed1996

Risk factors for graft failure in penetrating keratoplasty.

We clarified the preoperative risk factors for graft failure in penetrating keratoplasty with fresh donor corneas. This analysis covered 698 consecutive keratoplasty cases in a single center between 1971 and 1992, and was designed to assess the risk factors. The risk factors in penetrating keratoplasty were determined by the Cox multiple regression model which considers the follow-up periods and multiple factors simultaneously. The factors which worsen the prognosis of keratoplasty significantly were found to be preoperative endothelial dysfunction (hazard ratio = 2.3), prior glaucoma/ocular hypertension (hazard ratio = 2.0), preoperative corneal vascularization (hazard ratio for within one quadrant = 1.3, hazard ratio for 2 or more quadrants = 1.6), anterior synechiae of iris (hazard ratio = 1.5), aphakia or pseudophakia (hazard ratio = 1.4), and older donor age (hazard ratio = 1.3 in proportion to the increase of each 10-year period of age). Surgeons must take these risk factors into consideration to obtain a better prognosis for keratoplasty.

Adult↗
PubMed1996

Idiopathic ventricular fibrillation initiated by a short-coupled ventricular premature beat.

We report the case of a 38-year-old man who had idiopathic ventricular fibrillation (VF) which initiated by abnormally short-coupled ventricular premature beats. VF was successfully prevented by the combination of pilsicainide, propranolol, and verapamil. In particular, the effects of pilsicainide are assumed to exert an important effect in controlling this arrhythmia. Class Ic drugs may be effective for preventing VF initiated by short-coupled VPBs.

Adult↗