Proteasome inhibitors induce apoptosis by superoxide anion generation via NADPH oxidase 5 in human neuroblastoma SH-SY5Y cells

The ubiquitin-proteasome system (UPS) is a major proteolytic system that plays an important role in the regulation of various cell processes, such as cell cycle, stress response, and transcriptional regulation, especially in neurons, and dysfunction of UPS is considered to be a cause of neuronal cell death in neurodegenerative diseases. However, the mechanism of neuronal cell death caused by UPS dysfunction has not yet been fully elucidated. In this study, we investigated the mechanism of neuronal cell death induced by proteasome inhibitors using human neuroblastoma SH-SY5Y cells. Z-Leu-D-Leu-Leu-al (MG132), a proteasome inhibitor, induced apoptosis in SH-SY5Y cells in a concentration- and time-dependent manner. Antioxidants N-acetylcysteine and EUK-8 attenuated MG132-induced apoptosis. Apocynin and diphenyleneiodonium, inhibitors of NADPH oxidase (NOX), an enzyme that produces superoxide anions, also attenuated MG132-induced apoptosis. It was also found that MG132 treatment increased the expression of NOX5, a NOX family member, and that siRNA-mediated silencing of NOX5 and BAPTA-AM, which inhibits NOX5 by chelating calcium, suppressed MG132-induced apoptosis and production of reactive oxygen species in SH-SY5Y cells. These results suggest that MG132 induces apoptosis in SH-SY5Y cells through the production of superoxide anion by NOX5.

An Increase in Peroxiredoxin 6 Expression Induces Neurotoxic A1 Astrocytes in the Lumbar Spinal Cord of Amyotrophic Lateral Sclerosis Mice Model

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease with selective degeneration of motor neurons. It has been reported that an increase in the levels of inflammatory cytokines and glial cells such as reactive astrocytes is closely involved in the pathological progression of ALS. Recently, the levels of neuropathic cytotoxic (A1) astrocytes among reactive astrocytes have reportedly increased in the central nervous system of ALS mice, which induce motor neuron degeneration through the production of inflammatory cytokines and secretion of neuropathic factors. Hence, elucidating the induction mechanism of A1 astrocytes in ALS is important to understand the mechanism of disease progression in ALS. In this study, we observed that the expression of peroxiredoxin 6 (PRDX6), a member of the peroxiredoxin family, was markedly upregulated in astrocytes of the lumbar spinal cord of SOD1G93A mice model for ALS. Additionally, when PRDX6 was transiently transfected into the mouse astrocyte cell line C8-D1A and human astrocytoma cell line U-251 MG, the mRNA expression of complement C3 (a marker for A1 astrocyte phenotype) and inflammatory cytokines was increased. Furthermore, the mRNA expression of C3 and inflammatory cytokine was increased in C8-D1A and U-251 MG cells stably expressing PRDX6, and the increased mRNA expression was significantly suppressed by MJ33 (lithium[1-hexadecoxy-3-(2,2,2-trifluoroethoxy) propan-2-yl] methyl phosphate), an inhibitor of the phospholipase A2 activity of PRDX6. Our results suggest that the expression of PRDX6 in astrocytes plays an important role in the induction of A1 astrocytes and expression of inflammatory cytokines in the ALS mice model.

Schwann cell derived-peroxiredoxin protects motor neurons against hydrogen peroxide-induced cell death in mouse motor neuron cell line NSC-34

Schwann cells and oligodendrocytes secrete proteins that promote neuron survival, but their role in amyotrophic lateral sclerosis (ALS) is unclear. To address this question, we evaluated the effect of molecules secreted by Schwann cells on reactive oxygen species (ROS)-induced motor neuronal cell death. We observed that in motor neuron cell line NSC-34 cultures, the conditioned medium (CM) from Schwann cell line YST-1 (YST-1 CM) cultures had a protective effect against hydrogen peroxide-induced cell death. However, this protective effect of YST-1 CM was abolished by removing peroxiredoxin 1-4 (PRDX1-4) from the CM. We found that the expression of PRDX1 mRNA was markedly downregulated in the lumbar spinal cord of the superoxide dismutase 1 (SOD1)G93A mouse model of ALS. We also found that transient transfection of YST-1 cells with G93A SOD1 resulted in reduced PRDX1 mRNA expression. Additionally, in the mutant transfected cells, YST-1 CM showed decreased neuroprotective effect against hydrogen peroxide-induced NSC-34 cell death compared to those transfected with WT SOD1. Our results suggest that Schwann cells protect motor neurons from oxidative stress by secreting PRDX1 and that the reduction of PRDX secreted from Schwann cells contributes to increased ROS and associated motor neuronal death in ALS.

Dopamine inhibits the expression of proinflammatory cytokines of microglial cells through the formation of dopamine quinone in the mouse striatum

We previously reported that dopamine (DA) attenuated lipopolysaccharide (LPS)-induced expression of proinflammatory cytokines through the formation of DA quinone (DAQ) in murine microglial cell line BV-2 and primary murine microglial cells. To reveal whether DA inhibits the expression of proinflammatory cytokines of microglial cells through the formation of DAQ in the central nervous system (CNS), in this study, we examined the effect of DAQ on LPS-induced mRNA expression of proinflammatory cytokines in C57BL/6 mouse brain under two experimental conditions: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration and l-dopa/carbidopa administration. Acute MPTP administration reduced the number of tyrosine hydroxylase-positive cells in the substantia nigra, and decreased the level of quinoprotein, an indicator of DAQ formation, in the striatum. Real-time RT-PCR analysis revealed that intraperitoneal administration of LPS increased the mRNA levels of proinflammatory cytokines, including tumor-necrosis factor-α and interleukin-1β, in the striatum. These increases were enhanced in MPTP-treated mice. On the other hand, l-dopa/carbidopa administration increased the level of quinoprotein, attenuated the LPS-induced mRNA expression of proinflammatory cytokines, and reduced the LPS-induced increase in the number of microglial cells in the striatum. These results suggest that DA attenuate the expression of proinflammatory cytokines in microglia through the formation of DAQ in the CNS.

Noradrenaline protects neurons against H2 O2 -induced death by increasing the supply of glutathione from astrocytes via β3 -adrenoceptor stimulation

Oxidative stress has been implicated in a variety of neurodegenerative disorders, such as Alzheimer's and Parkinson's disease. Astrocytes play a significant role in maintaining survival of neurons by supplying antioxidants such as glutathione (GSH) to neurons. Recently, we found that noradrenaline increased the intracellular GSH concentration in astrocytes via β₃ -adrenoceptor stimulation. These observations suggest that noradrenaline protects neurons from oxidative stress-induced death by increasing the supply of GSH from astrocytes to neurons via the stimulation of β₃ -adrenoceptor in astrocytes. In the present study, we examined the protective effect of noradrenaline against H₂ O₂ -induced neurotoxicity using two different mixed cultures: the mixed culture of human astrocytoma U-251 MG cells and human neuroblastoma SH-SY5Y cells, and the mouse primary cerebrum mixed culture of neurons and astrocytes. H₂ O₂ -induced neuronal cell death was significantly attenuated by pretreatment with noradrenaline in both mixed cultures but not in single culture of SH-SY5Y cells or in mouse cerebrum neuron-rich culture. The neuroprotective effect of noradrenaline was inhibited by SR59230A, a selective β₃ -adrenoceptor antagonist, and CL316243, a selective β₃ -adrenoceptor agonist, mimicked the neuroprotective effect of noradrenaline. DL-buthionine-[S,R]-sulfoximine, a GSH synthesis inhibitor, negated the neuroprotective effect of noradrenaline in both mixed cultures. MK571, which inhibits the export of GSH from astrocytes mediated by multidrug resistance-associated protein 1, also prevented the neuroprotective effect of noradrenaline. These results suggest that noradrenaline protects neurons against H₂ O₂ -induced death by increasing the supply of GSH from astrocytes via β₃ -adrenoceptor stimulation.

Endogenous Apelin Is Protective Against Age-Associated Loss of Retinal Ganglion Cells in Mice

Age-associated loss of retinal ganglion cells (RGCs) causes visual deficits, but there is not yet any therapeutic agent to prevent the loss of these cells. Herein, we report that apelin, an endogenous peptide ligand of APJ receptor, is protective against the age-related loss of RGCs in mice. The mRNA expression of apelin was reduced in the retina of old mice compared with that in young mice, whereas retinal APJ expression increased with age. Immunofluorescence staining showed that APJ was present in RGCs and their surrounding cells expressed apelin. In addition, both functional and histological analyses demonstrated that apelin deficiency accelerated the loss of RGCs associated with age in mice. These results suggest that endogenous apelin plays a protective role against the degeneration of RGCs and that the apelinergic axis may be a new target for preventing age-related visual impairment.

Dopamine attenuates lipopolysaccharide-induced expression of proinflammatory cytokines by inhibiting the nuclear translocation of NF-κB p65 through the formation of dopamine quinone in microglia

Many reports have indicated that dopamine has immunomodulatory effects on peripheral immune cells. The purpose of this study was to reveal the immunomodulatory effect of dopamine on the expression of proinflammatory cytokines in microglial cells, which are the immune cells of the central nervous system. In murine microglial cell line BV-2 cells, pretreatment with dopamine for 24 h attenuated the lipopolysaccharide (LPS)-induced expression of proinflammatory cytokines such as tumor-necrosis factor-α, interleukin-1β, and interleukin-6. Neither (5R)-8-chloro-3-methyl-5-phenyl-1,2,4,5-tetrahydro-3-benzazepin-7-ol; hydrochloride (SCH-23390) nor sulpiride, which are dopamine D₁-like and D₂-like receptor antagonists, respectively, affected the attenuation of LPS-induced expression of cytokines by dopamine. In addition, pretreatment with neither (-)-(6aR,12bR)-4,6,6a,7,8,12b-Hexahydro-7-methylindolo[4,3-a]phenanthridin (CY208-243) nor bromocriptine, dopamine D₁-like and D₂-like receptor agonists, respectively, was effective in doing so. However, N-acetylcysteine (NAC), which inhibits dopamine oxidation to dopamine quinone, did inhibit this attenuated expression. Dopamine increased the level of quinoproteins, and this increase was inhibited by NAC. Western blot and immunocytochemical analyses revealed that dopamine inhibited LPS-induced nuclear translocation of nuclear factor-kappa B (NF-κB) p65. Dopamine also attenuated the expression of cytokines and the nuclear translocation of NF-κB p65 induced by LPS in mouse microglial cells in primary culture. These results suggest that dopamine attenuated LPS-induced expression of cytokines by inhibiting the nuclear translocation of NF-κB p65 through the formation of dopamine quinone in microglial cells.

Preferences for health information in middle-aged Japanese workers based on health literacy levels: a descriptive study

OBJECTIVES

To describe the health information preferences in middle-aged Japanese workers based on health literacy (HL) levels and presence of medications.

STUDY DESIGN

A cross-sectional study.

METHODS

We performed a web-based questionnaire survey with Japanese workers aged below 60 years. HL was assessed using the total score of communicative skills (five items) and critical skills (four items) from the 14-item Health Literacy Scale. Regarding their health information preferences, participants were asked about the health information they wanted (four items), could easily understand (six items), or easily use (two items) and answered on a 4-point scale (strongly agree/agree/disagree/strongly disagree). The percentages of the affirmative responses (strongly agree or agree) were compared among tertiles based on the HL score.

RESULTS

We obtained data from a total of 3387 volunteers, of whom 510 participants were on either antihypertensive, lipid-lowering, or antidiabetic drugs. Compared with the high HL and middle HL groups, low HL had fewer affirmative responses to most health information items. Health information items received 70% of affirmative responses even in the low HL level. They were visually shown by figures or pictures, highlighted by colors for important points, could be read in 1-2 min, and were accessed on the Internet, regardless of the presence of medications. Additionally, the explanation for mechanisms of medications or lifestyle to prevent or improve diseases showed high affinity in all HL levels, only for those on medications.

CONCLUSIONS

This result generates a hypothesis that low HL individuals have a low interest in health information. Our data showed several possible forms of health information with high affinity based on HL levels that would help plan future population approaches.

A red fluorophore comprising a borinate-containing xanthene analogue as a polyol sensor

A xanthene derivative containing a borinate moiety emitted red fluorescence with a high quantum yield. The interaction between the borinate and a sugar molecule induced a fluorescence change based on the change in the HOMO-LUMO gap. The response was pH-resistant in a wide range. In addition, catechol quenched through photoinduced electron transfer. The red fluorescence and polyol binding ability of dyes will pave the way for new biological applications of chemical sensors.

An apelin receptor antagonist prevents pathological retinal angiogenesis with ischemic retinopathy in mice

Pathological retinal angiogenesis is caused by the progression of ischemic retinal diseases and can result in retinal detachment and irreversible blindness. This neovascularization is initiated from the retinal veins and their associated capillaries and involves the overgrowth of vascular endothelial cells. Since expression of the apelin receptor (APJ) is restricted to the veins and proliferative endothelial cells during physiological retinal angiogenesis, in the present study, we investigated the effect of APJ inhibition on pathological retinal angiogenesis in a mouse model of oxygen-induced retinopathy (OIR). In vitro experiments revealed that ML221, an APJ antagonist, suppressed cultured-endothelial cell proliferation in a dose-dependent manner. Intraperitoneal administration of ML221 inhibited pathological angiogenesis but enhanced the recovery of normal vessels into the ischemic regions in the retina of the OIR model mice. ML221 did not affect the expression levels of vascular endothelial growth factor (VEGF) and its receptor (VEGFR2) in the retina. APJ was highly expressed in the endothelial cells within abnormal vessels but was only detected in small amounts in morphologically normal vessels. These results suggest that APJ inhibitors selectively prevent pathological retinal angiogenesis and that the drugs targeting APJ may be new a candidate for treating ischemic retinopathy.

Noradrenaline increases intracellular glutathione in human astrocytoma U-251 MG cells by inducing glutamate-cysteine ligase protein via β3-adrenoceptor stimulation

Glutathione (GSH) plays a critical role in protecting cells from oxidative damage. Since neurons rely on the supply of GSH from astrocytes to maintain optimal intracellular GSH concentrations, the GSH concentration of astrocytes is important for the survival of neighboring neurons against oxidative stress. The neurotransmitter noradrenaline is known to modulate the functions of astrocytes and has been suggested to have neuroprotective properties in neurodegenerative diseases. To elucidate the mechanisms underlying the neuroprotective properties of noradrenaline, in this study, we investigated the effect of noradrenaline on the concentrations of intracellular GSH in human U-251 malignant glioma (MG; astrocytoma) cells. Treatment of the cells with noradrenaline for 24h concentration-dependently increased their intracellular GSH concentration. This increase was inhibited by a non-selective β-adrenoceptor antagonist propranolol and by a selective β3-adrenoceptor antagonist SR59230A, but not by a non-selective α-adrenoceptor antagonist phenoxybenzamine, or by a selective β1-adrenoceptor antagonist atenolol or by a selective β2-adrenoceptor antagonist butoxamine. In addition, the selective β3-adrenoceptor agonist CL316243 increased the intracellular GSH in U-251 MG cells. Treatment of the cells with noradrenaline (10μM) for 24h increased the protein level of the catalytic subunit of glutamate-cysteine ligase (GCLc), the rate-limiting enzyme of GSH synthesis; and this increase was inhibited by SR59230A. These results thus suggest that noradrenaline increased the GSH concentration in astrocytes by inducing GCLc protein in them via β3-adrenoceptor stimulation.

Dopamine inhibits lipopolysaccharide-induced nitric oxide production through the formation of dopamine quinone in murine microglia BV-2 cells

Dopamine (DA) has been suggested to modulate functions of glial cells including microglial cells. To reveal the regulatory role of DA in microglial function, in the present study, we investigated the effect of DA on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine microglial cell line BV-2. Pretreatment with DA for 24 h concentration-dependently attenuated LPS-induced NO production in BV-2 cells. The inhibitory effect of DA on LPS-induced NO production was not inhibited by SCH-23390 and sulpiride, D1-like and D2-like DA receptor antagonists, respectively. In addition, pretreatment with (-)-(6aR,12bR)-4,6,6a,7,8,12b-Hexahydro-7-methylindolo[4,3-a]phenanthridin (CY 208-243) and bromocriptine, D1-like and D2-like DA receptor agonists, respectively, did not affect the LPS-induced NO production. N-Acetylcysteine, which inhibits DA oxidation, completely inhibited the effect of DA. Tyrosinase, which catalyzes the oxidation of DA to DA quionone (DAQ), accelerated the inhibitory effect of DA on LPS-induced NO production. These results suggest that DA attenuates LPS-induced NO production through the formation of DAQ in BV-2 cells.

Potential of D-Octaarginine-Linked Polymers as an in Vitro Transfection Tool for Biomolecules

We have been investigating the potential use of cell-penetrating peptide-linked polymers as a novel penetration enhancer. Since previous in vivo studies demonstrated that poly(N-vinylacetamide-co-acrylic acid) bearing D-octaarginine, a typical cell-penetrating peptide, enhanced membrane permeation of biomolecules, its potential as an in vitro transfection tool was evaluated in this study. A plasmid DNA encoding green fluorescent protein (pGFP-C1), β-galactosidase, and bovine serum albumin (BSA) were used as model biomolecules. Anionic pGFP-C1 interacted electrostatically with cationic d-octaarginine-linked polymers. When the ratio of mass concentration of polymers to that of pGFP-C1 reached 2.5, complexes whose size and zeta potential were approximately 200 nm and 15 mV, respectively, were obtained. GFP expression was observed in cells incubated with complexes prepared under conditions in which the polymer/pDNA concentration ratio exceeded 2.5. The expression level elevated with an increase in the concentration ratio, but physicochemical properties of the complexes remained unchanged. Results suggested that free polymers contributed to pGFP-C1 internalization. Another cell study demonstrated that β-galactosidase premixed with polymers was taken up into cells in its active tetrameric form. Similar electrostatic interaction-driven complex formation was observed for BSA charged negatively in neutral solution. However, it appeared that the internalization processes of BSA differed from those of pGFP-C1. A mass concentration-dependent increase in internalized BSA was observed, irrespective of the polymer/protein concentration ratio. Due to frail interactions, polymers that were released from the complexes and subsequently immobilized on cell membranes might also contribute to membrane permeation of BSA.

Safety and efficacy of selective sac extraction method of inguinal hernia repair in children: results of a prospective study

PURPOSE

A prospective study was conducted to confirm the safety and efficacy of the selective sac extraction method (SSEM) of inguinal hernia repairs in children.

METHODS

Primary endpoints of the study were the incidence of any complication related to the SSEM, or hernia recurrence. Secondary endpoints included the success rate of the SSEM, length of incision at the end of operation, and duration of operation. The incidence of contralateral manifestation of hernia was also examined.

RESULTS

Between October 2009 and December 2011, a total of 317 repairs, 145 male repairs and 172 female repairs, were performed by applying the SSEM. There were three operative conversions, and the success rate of the SSEM was 99% in both male and female patients. The length of incision ranged from 4.0 to 12.5 mm (median 6.0 mm) and was ≤7.0 mm in 93% repairs. The incisional length for male repairs ranged from 4.0 to 12.5 mm (median 6.0 mm) and was ≤7.0 mm in 86% repairs, while it ranged from 4.0 to 9.0 mm (median 5.5 mm) in female repairs and was ≤6.5 mm in 96% repairs. The duration of the operation for unilateral repair ranged from 9 to 66 min (median 21 min). Eighty percent of repairs were examined 6-44 months (median 12 months) after the operation. There was one (0.4%) recurrence among 250 repairs and two (1.7%) cases of testicular dislocation among 115 male repairs. Contralateral hernia presented in 19 (9.5%) of 199 patients with unilateral hernia who underwent the follow-up.

CONCLUSIONS

The feasibility of the SSEM was reconfirmed, and it was revealed that the complication and recurrence rates were low and acceptable. The SSEM is safe and effective, and should be a standard method for repairing inguinal hernia in children.

Inhibition of apelin expression switches endothelial cells from proliferative to mature state in pathological retinal angiogenesis

The recruitment of mural cells such as pericytes to patent vessels with an endothelial lumen is a key factor for the maturation of blood vessels and the prevention of hemorrhage in pathological angiogenesis. To date, our understanding of the specific trigger underlying the transition from cell growth to the maturation phase remains incomplete. Since rapid endothelial cell growth causes pericyte loss, we hypothesized that suppression of endothelial growth factors would both promote pericyte recruitment, in addition to inhibiting pathological angiogenesis. Here, we demonstrate that targeted knockdown of apelin in endothelial cells using siRNA induced the expression of monocyte chemoattractant protein-1 (MCP-1) through activation of Smad3, via suppression of the PI3K/Akt pathway. The conditioned medium of endothelial cells treated with apelin siRNA enhanced the migration of vascular smooth muscle cells, through MCP-1 and its receptor pathway. Moreover, in vivo delivery of siRNA targeting apelin, which causes exuberant endothelial cell proliferation and pathological angiogenesis through its receptor APJ, led to increased pericyte coverage and suppressed pathological angiogenesis in an oxygen-induced retinopathy model. These data demonstrate that apelin is not only a potent endothelial growth factor, but also restricts pericyte recruitment, establishing a new connection between endothelial cell proliferation signaling and a trigger of mural recruitment.

[Diagnosis and treatment of acute appendicitis in children]

In this review article, we discussed the pathogenesis, pathophysiology, diagnosis and treatment of acute appendicitis in children. Indications for early surgery, the operative methods of laparoscopic appendectomy and the treatment outcome are also presented.

Association of extrahepatic bile duct duplication with pancreaticobiliary maljunction and congenital biliary dilatation in children: a case report and literature review

We herein report a case of cystic-type congenital biliary dilatation (CBD) in whom an extremely rare anomalous duplication of the common bile duct and pancreaticobiliary maljunction were diagnosed intraoperatively by meticulous surgical manipulations via conventional open surgery. By performing a dissection at the outer epicholedochal layer of the cyst, a thin cord-like structure shown to be the distal part of the common bile duct was identified. A further exploration revealed that the most distal (extra- and intrapancreatic) part of the common bile duct was duplicated, and each branch of the duct was connected to the main and accessory pancreatic ducts. The experience with our case and a literature review showed that extrahepatic bile duct duplication is generally associated with pancreaticobiliary maljunction and CBD. We conclude that an extremely careful exploration with delicate and meticulous surgical manipulation is essential to identify these morphological anomalies and prevent intraoperative and postoperative complications of CBD, such as pancreatic duct injury or pancreatitis.

Apelin deficiency accelerates the progression of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons. Recent studies have implicated that chronic hypoxia and insufficient vascular endothelial growth factor (VEGF)-dependent neuroprotection may lead to the degeneration of motor neurons in ALS. Expression of apelin, an endogenous ligand for the G protein-coupled receptor APJ, is regulated by hypoxia. In addition, recent reports suggest that apelin protects neurons against glutamate-induced excitotoxicity. Here, we examined whether apelin is an endogenous neuroprotective factor using SOD1^G93A mouse model of ALS. In mouse CNS tissues, the highest expressions of both apelin and APJ mRNAs were detected in spinal cord. APJ immunoreactivity was observed in neuronal cell bodies located in gray matter of spinal cord. Although apelin mRNA expression in the spinal cord of wild-type mice was not changed from 4 to 18 weeks age, that of SOD1^G93A mice was reduced along with the paralytic phenotype. In addition, double mutant apelin-deficient and SOD1^G93A displayed the disease phenotypes earlier than SOD1^G93A littermates. Immunohistochemical observation revealed that the number of motor neurons was decreased and microglia were activated in the spinal cord of the double mutant mice, indicating that apelin deficiency pathologically accelerated the progression of ALS. Furthermore, we showed that apelin enhanced the protective effect of VEGF on H₂O₂-induced neuronal death in primary neurons. These results suggest that apelin/APJ system in the spinal cord has a neuroprotective effect against the pathogenesis of ALS.

Apelin Is a Crucial Factor for Hypoxia-Induced Retinal Angiogenesis

Objective— To investigate the role of endogenous apelin in pathological retinal angiogenesis.

Methods and Results— The progression of ischemic retinal diseases, such as diabetic retinopathy, is closely associated with pathological retinal angiogenesis, mainly induced by vascular endothelial growth factor (VEGF) and erythropoietin. Although antiangiogenic therapies using anti-VEGF drugs are effective in treating retinal neovascularization, they show a transient efficacy and cause general adverse effects. New therapeutic target molecules are needed to resolve these issues. It was recently demonstrated that the apelin/APJ system, a newly deorphanized G protein–coupled receptor system, is involved in physiological retinal vascularization. Retinal angiography and mRNA expression were examined during hypoxia-induced retinal angiogenesis in a mouse model of oxygen-induced retinopathy. Compared with age-matched control mice, retinal apelin expression was dramatically increased during the hypoxic phase in oxygen-induced retinopathy model mice. APJ was colocalized in proliferative cells, which were probably endothelial cells of the ectopic vessels in the vitreous body. Apelin deficiency hardly induced hypoxia-induced retinal angiogenesis despite the upregulation of VEGF and erythropoietin mRNA in oxygen-induced retinopathy model mice. Apelin small and interfering RNA suppressed the proliferation of endothelial cells independent of the VEGF/VEGF receptor 2 signaling pathway.

Conclusion— These results suggest that apelin is a prerequisite factor for hypoxia-induced retinal angiogenesis.

Genetic analysis of interspecific incompatibility in Brassica rapa

In interspecific pollination of Brassica rapa stigmas with Brassica oleracea pollen grains, pollen tubes cannot penetrate stigma tissues. This trait, called interspecific incompatibility, is similar to self-incompatibility in pollen tube behaviors of rejected pollen grains. Since some B. rapa lines have no interspecific incompatibility, genetic analysis of interspecific incompatibility was performed using two F(2) populations. Analysis with an F(2) population between an interspecific-incompatible line and a self-compatible cultivar 'Yellow sarson' having non-functional alleles of S-locus genes and MLPK, the stigmas of which are compatible with B. oleracea pollen grains, revealed no involvement of the S locus and MLPK in the difference of their interspecific incompatibility phenotypes. In QTL analysis of the strength of interspecific incompatibility, three peaks of LOD scores were found, but their LOD scores were as high as the threshold value, and the variance explained by each QTL was small. QTL analysis using another F(2) population derived from selected parents having the highest and lowest levels of interspecific incompatibility revealed five QTLs with high LOD scores, which did not correspond to those found in the former population. The QTL having the highest LOD score was found in linkage group A02. The effect of this QTL on interspecific incompatibility was confirmed by analyzing backcrossed progeny. Based on synteny of this QTL region with Arabidopsis thaliana chromosome 5, a possible candidate gene, which might be involved in interspecific incompatibility, is discussed.

Hypocretin/orexin and narcolepsy: new basic and clinical insights

Narcolepsy is a chronic sleep disorder, characterized by excessive daytime sleepiness (EDS), cataplexy, sleep paralysis and hypnagogic hallucinations. Both sporadic (95%) and familial (5%) forms of narcolepsy exist in humans. The major pathophysiology of human narcolepsy has been recently discovered based on the discovery of narcolepsy genes in animals; the genes involved in the pathology of the hypocretin/orexin ligand and its receptor. Mutations in hypocretin-related genes are rare in humans, but hypocretin ligand deficiency is found in a large majority of narcolepsy with cataplexy. Hypocretin ligand deficiency in human narcolepsy is probably due to the post-natal cell death of hypocretin neurones. Although a close association between human leucocyte antigen (HLA) and human narcolepsy with cataplexy suggests an involvement of autoimmune mechanisms, this has not yet been proved. Hypocretin deficiency is also found in symptomatic cases of narcolepsy and EDS with various neurological conditions, including immune-mediated neurological disorders, such as Guillain-Barre syndrome, MA2-positive paraneoplastic syndrome and neuromyelitis optica (NMO)-related disorder. The findings in symptomatic narcoleptic cases may have significant clinical relevance to the understanding of the mechanisms of hypocretin cell death and choice of treatment option. The discoveries in human cases lead to the establishment of the new diagnostic test of narcolepsy (i.e. low cerebrospinal fluid hypocretin-1 levels for 'narcolepsy with cataplexy' and 'narcolepsy due to medical condition'). As a large majority of human narcolepsy patients are ligand deficient, hypocretin replacement therapy may be a promising new therapeutic option, and animal experiments using gene therapy and cell transplantations are in progress.

Transient receptor potential (TRP) channels and taste sensation

Humans have 5 basic taste sensations: sweet, bitter, sour, salty, and umami (taste of 1-amino acids). Among 33 genes related to transient receptor potential (TRP) channels, 3--including TRP-melastatin 5 (TRPM5), polycystic kidney disease-1-like 3 (PKD1L3), and polycystic kidney disease-2-like 1 (PKD2L1)--are specifically and abundantly expressed in taste receptor cells. TRP-melastatin 5 is co-expressed with taste receptors T1Rs and T2Rs, and functions as a common downstream component in sweet, bitter, and umami taste signal transduction. In contrast, polycystic kidney disease-1-like 3 and polycystic kidney disease-2-like 1 are co-expressed in distinct subsets of taste receptor cells not expressing TRP-melastatin 5. In the heterologous expression system, cells expressing both polycystic kidney disease-1-like 3 and polycystic kidney disease-2-like 1 responded to sour stimuli, showing a unique "off-response" property. Genetic ablation of poly-cystic kidney disease-2-like 1-expressing cells resulted in elimination of gustatory nerve response to sour stimuli, indicating that cells expressing polycystic kidney disease-2-like 1 function as sour taste detectors. These results suggest that polycystic kidney disease-1-like 3/polycystic kidney disease-2-like 1 may play a significant role, possibly as taste receptors, in sour taste sensation.

Visceral coverage with absorbable mesh followed by split-thickness skin graft in the treatment of ruptured giant omphalocele

We report a case of ruptured giant omphalocele in whom herniated organs were successfully covered by an absorbable mesh and a subsequent skin graft. A 2,200 g male baby was born at 35 weeks of gestation. An abdominal wall abnormality was detected by prenatal ultrasound at 21 weeks of gestation. At birth, the entire liver, stomach, and small and large bowel had herniated from the defect of the abdominal wall. The thorax and abdomen were highly underdeveloped, and attempts to reduce the organs into the abdomen were unsuccessful due to the extremely small abdominal cavity and associated pulmonary hypoplasia. To protect the herniated organs and prevent abdominal infections, the organs were covered by a polyglycan mesh and subsequently a meshed split-thickness skin graft. Ten weeks later, it was confirmed that the organs were completely covered by epithelialized tissue. However, the patient suffered from frequent respiratory infections and finally died of respiratory insufficiency. Based on the experience of the patient, we conclude that coverage of the herniated organs with an absorbable mesh and a skin graft is a recommendable treatment in ruptured giant omphalocele.

Splenic autotransplantation for a congested and enlarged wandering spleen with torsion: report of a case

In children with diseases of the spleen, every effort should be made to preserve the organ, to prevent severe infections postsplenectomy. We report the case of a 7-year-old girl with torsion of a wandering spleen who we treated by autotransplantation of splenic tissues following splenectomy, when fixation of the enlarged spleen seemed impossible. Spleen scintigraphy showed uptake in the regenerating splenic tissues 9 months after surgery, and evidence of an increase in the size of the tissues 23 months after surgery. Howell-Jolly bodies had disappeared by 16 months after surgery. These findings suggested that the transplanted splenic tissues were resuming splenic functions. Based on our experience with this case, we conclude that autotransplantation after splenectomy is a treatment option for wandering spleen with torsion when fixation seems difficult because of splenic congestion and enlargement.

Efficacy of granulocyte apheresis in pediatric patients with ulcerative colitis: a pilot study

OBJECTIVES

Granulocyte apheresis (GCAP), involving the removal of granulocytes from the blood, may improve clinical symptoms and facilitate a reduction in the dose of steroids in adult patients with ulcerative colitis. As a preliminary trial, GCAP was used to taper the dose of steroids in 4 pediatric patients with ulcerative colitis.

METHODS

Three males and 1 female ranging from 11 to 17 years old were treated with GCAP once per week for 5 consecutive weeks/course. The ages of patients at clinical onset ranged from 8 to 12 years and the length of time from the clinical onset to GCAP treatment ranged from 28 to 58 months (median, 38.5 months).

RESULTS

In 2 patients, symptoms and signs indicating disease activity improved after 2 courses of GCAP. Laboratory data and endoscopic findings also improved after treatment and the clinical efficacy was judged to be excellent in these patients. In 1 patient, GCAP improved laboratory and endoscopic hallmarks, but bloody stools persisted. Finally, the treatment was ineffective in the fourth patient who eventually underwent surgery.

CONCLUSIONS

GCAP is effective in improving clinical symptoms and may play an important role in converting steroid therapy to other treatments in children with steroid-refractory or steroid-dependent ulcerative colitis.

Clinical characteristics and surgical treatment of perianal and perineal rhabdomyosarcoma: analysis of Japanese patients and comparison with IRSG reports

Rhabdomyosarcomas of the perianal and perineal regions are uncommon. This study was performed to clarify the clinical characteristics and guidelines of surgical treatment of patients with perianal and perineal rhabdomyosarcomas younger than 20 years of age. Twenty-nine patients, 26 patients identified in the Japanese literature and three of our own, were analyzed and the results were compared with the data reported from the Intergroup Rhabdomyosarcoma Study Group (IRSG). Female predominance and a twin-peak age distribution in infancy and adolescence were characteristic findings of the Japanese patients that were not observed in the IRSG studies. The demographic differences between the two groups were attributed to the differences in demographics of patients younger than 10 years of age. Of the 29 patients, 17 were categorized into clinical groups III/IV and 21 patients into stages 3/4. Alveolar histology was diagnosed in 18 patients. In patients more than 10 years of age, the female predominance was more prominent and the incidences of advanced clinical groups/stages and alveolar histology were significantly higher than those in patients younger than 10 years of age. Inguinal lymph nodes were always involved in patients with lymph node metastases and three patients developed metastases to the breast. Information regarding the survival time was available for 18 patients and the 5-year overall survival was 20%. Two patients with a group I/stage 2 tumor and one with a group II/stage 3 tumor survived for more than 2 years with no evidence of the disease. In these patients, the tumors were excised by primary surgery or primary reexcision and they were not accompanied by lymph node metastasis. Based on these data, complete tumor resection prior to chemotherapy should be pursued and the inguinal lymph nodes should be at least sampled because nodal involvement is closely associated with the patient's prognosis.

Secretion and expression of epithelial markers supports the biliary origin of solitary nonparasitic cyst of the liver in infancy

Solitary nonparasitic cyst of the liver (SNPCL) is rare in children. Although there are several hypotheses regarding the pathogenesis, the true origin of SNPCL remains unknown. The authors present an infant with a huge SNPCL in whom the epithelial markers, CA19-9, DU-PAN-2, and SPan-1, were elevated in the serum and cystic fluid. The presence of CA19-9 and DU-PAN-2 was shown by immunohistochemistry in the cystic epithelia. These indicate that the classical idea of biliary origin of SNPCL is supported.

[Nonpenetrating traumatic injury of the thoracic aorta and left subclavian artery; report of a case]

Nonpenetrating traumatic injury of the thoracic aorta and/or its major branch is usually fatal and the treatment of this condition carries extremely high risk because of associated visceral organ injuries. Accurate diagnosis have been difficult. However, recently developed multi-slice helical computed tomography (CT) is highly sensitive in early detection of precise location of injury and associating injuries of other organs. Here we report our case with combined thoracic aortic and left subclavian artery injuries, diagnosed by 3-dimensional (3-D) CT and treated successfully.

Diffuse xanthogranulomatous pyelonephritis in a patient with myotonic dystrophy and cerebral palsy

Xanthogranulomatous pyelonephritis (XGP), a morphological and clinical variant of chronic pyelonephritis, is an uncommon disease in children. It is characterized by the destruction of the renal parenchyma and replacement by granulomatous tissue containing foamy lipid-laden macrophages and is classified into diffuse and focal XGP. We present a case of diffuse XGP in a child with myotonic dystrophy complicated by cerebral palsy and discuss the importance of correct diagnosis and preoperative management to reduce inflammation and improve malnutrition associated with the disease.

Laparoscopic versus open appendectomy in children with uncomplicated and complicated appendicitis

PURPOSE

To address whether laparoscopic appendectomy could be an alternative to conventional open appendectomy in children with complicated appendicitis as well as uncomplicated appendicitis, a retrospective study comparing laparoscopic and open appendectomies was performed.

METHODS

One hundred patients who were treated by immediate appendectomy, either laparoscopically or by the open method, between May 2000 and August 2003 were included in the study. There were 53 patients in the laparoscopic appendectomy group and 47 patients in the open appendectomy group.

RESULTS

The operating time was significantly longer for laparoscopic appendectomy than for open appendectomy (P < .001). The length of hospital stay was significantly shorter in laparoscopic appendectomy in patients with uncomplicated appendicitis (P = .001). Thirteen of the 100 patients (13.0%) had 15 postoperative complications including wound infection (n = 8), intraabdominal abscess (n = 4), stitch abscess (n = 2), and small bowel obstruction (n = 1). In both uncomplicated and complicated appendicitis, there was no significant difference between laparoscopic and open appendectomies in the complication rates, and the incidences of each complication did not differ between the procedures. Among the 14 patients with generalized peritonitis, postoperative complications were seen in 5 patients (35.7%). Although the presence of generalized peritonitis was associated significantly with postoperative complications (P = .017), there was no significant association between the procedure and complications. Overall treatment costs were increased by 26.0% in laparoscopic appendectomy.

CONCLUSIONS

Laparoscopic appendectomy should remain an option in children with uncomplicated and complicated appendicitis, and when laparoscopy is selected, consideration of the advantages and disadvantages of the procedure is essential.

Infantile intestinal leiomyosarcoma is prognostically favorable despite histologic aggressiveness: case report and literature review

Intestinal leiomyosarcomas in children are extremely rare. The authors present a case of infantile intestinal leiomyosarcoma of the colon that was resected and was classified histologically as grade 2 because of abundant mitoses. The tumor cells infiltrated the submucosa and the serosal surface. Immunohistochemically, these cells were positive for alpha-smooth muscle actin but not for CD34 or CD117, by which the tumor was differentiated from gastrointestinal stromal tumor (GIST). The patient underwent follow-up without adjuvant therapy and is now doing well with no evidence of the disease for 42 months. Based on the current case and a review of 18 reported cases, it is concluded that infantile intestinal leiomyosarcoma, which is differentiated from GIST, has a favorable prognosis even when the histologic appearance is suggestive of aggressive biological characteristics. Adjuvant therapy is unnecessary when tumors are completely resected.

D-lactic acidosis in short-bowel syndrome managed with antibiotics and probiotics

D-lactic acidosis sometimes occurs in malabsorbed patients with short-bowel syndrome and is characterized by recurrent episodes of encephalopathy and metabolic acidosis. The characteristic neurologic abnormalities and the presence of metabolic acidosis raises a diagnostic suspicion, and the diagnosis is made when the serum level of D-lactic acid is greater than 3 mmol/L. Standard treatment consists of restricting oral carbohydrates or fasting, correction of metabolic acidosis, and a long-term suppression of pathogenic floras with antibiotics. The authors present a case of D-lactic acidosis in a 22-year-old patient with short-bowel syndrome, to whom intestinal bacterial agents (probiotics) were given in addition to oral kanamycin. Recolonization of the intestine with nonpathogenic floras should be a long-term treatment for D-lactic acidosis.

Epidermoid cyst: rare testicular tumor in children

Epidermoid cyst of the testis, extremely rare in children, is a non-teratomatous benign tumor, and testis-sparing surgery should be the treatment of choice. To prevent unnecessary orchiectomy, recognition of this rare tumor in children is essential.

Umbilicoplasty for large protruding umbilicus accompanying umbilical hernia: a simple and effective technique

A large umbilical protrusion with redundant skin accompanying an umbilical hernia sometimes needs umbilicoplasty. Although several different techniques for making umbilical depression have been used, the results of the plastic surgery are sometimes unsatisfactory due to postoperative flattening or disappearance of the umbilical depression. To make a permanent umbilical depression that is cosmetically acceptable, we have modified the techniques. Umbilicoplasty was performed in 14 children whose ages ranged from 6 months-6 years and 3 months (median, 1 year and 10 months) and who had umbilical hernia with a large umbilical protrusion. After the fascial defect was closed, the diameter of the umbilicus was reduced to half that before surgery by removing fan-shaped skin flaps and approximating skin edges, and then inverting the umbilicus and fixing it caudally to the fascia and skin. There were no postoperative complications, and no flattening or disappearance of umbilical depression was observed during the follow-up of 10-19 months. The authors' technique of umbilicoplasty for a large protruding umbilicus accompanying umbilical hernia is a simple method that produces acceptable cosmetic results.

Reproducibility of the brain perfusion index for measuring cerebral blood flow using technetium-99m compounds

We previously developed an alternative method for estimating the brain perfusion index (BPI) using technetium-99m compounds and spectral analysis (SA) for quantification of cerebral blood flow (CBF). In this study, we investigated the reproducibility of the BPI values obtained by SA (BPIS) using a double injection of technetium-99m ethyl cysteinate dimer without any intervention, and compared it with that of the BPI values obtained by graphical analysis (BPIG). The BPIS values in the first (x) and second sessions (y) correlated closely (y=0.921x+0.036; r=0.962; n=64; s.e.e.=0.058 min-1). Although the BPIG values in the first (x) and second sessions (y) also correlated (y=0.942x+0.040; r=0.916; n=64; s.e.e.=0.061 min-1), the correlation coefficient for BPIS was significantly higher than that for BPIG. The reproducibility was dependent on the injection dose ratio of the second session to the first (R). The difference in BPI between the first and second sessions tended to be smaller when 1.5<R<2.5 than when 0<R<1.5 or 2.5<R. These results suggest that the reproducibility of BPIS is satisfactory and that it can be applied to two sequential measurements of CBF using a double injection of 99mTc compounds. When applying our method to such measurements, it is recommended that R is taken as approximately 2.0.

Treatment of VX2 carcinoma implanted in the liver with arterial and intraperitoneal administration of oily anticancer agents

PURPOSE

Long-term survival and cure cannot be achieved in patients with unresectable, advanced abdominal cancer, because no chemotherapeutic treatment has definite antitumor activity for malignant solid tumor and its dissemination. In this study, arterial and intraperitoneal administration of oily anticancer agents, which have properties that permit targeted chemotherapy for VX2 carcinoma implanted in the liver, was attempted to achieve long-term survival.

MATERIALS AND METHODS

Rabbits bearing VX2 tumors in the liver measuring 1-2 cm in diameter received an arterial injection of 0.2 ml of nitrogen mustard N-Oxide (HN2-O) dissolved in Lipiodol (7.5 mg/ml), a newly developed oily anticancer agent, for the tumor and an intraperitoneal injection of a cocktail of oily anticancer agents for the prevention of intraperitoneal dissemination.

RESULTS

Twelve out of thirteen rabbits survived and VX2 cancer was not observed in these 12 rabbits. The controls received a sham operation, an intraperitoneal injection of the cocktail of oily anticancer agents alone, or an arterial injection of HN2-O/Lipiodol alone. In these control groups, 27 out of 29 rabbits died of cancer. To examine the dose form for arterial injection, 14 rabbits received an arterial injection of the simple mixture of HN2-O dissolved in physiological saline and Lipiodol, with an additional intraperitoneal injection of the cocktail. Eight of these 14 rabbits died of enlargement of the hepatic tumor and peritoneal dissemination.

CONCLUSION

Long-term survival and cure was achieved in almost all rabbits bearing VX2 tumor in the liver by simultaneous arterial and intraperitoneal injection of oily anticancer agents.

An actin-binding protein, CAP, is expressed in a subset of rat taste bud cells

Single cell cDNA libraries were constructed from taste bud cells of rat circumvallate papillae. Using three steps of screening, including differential hybridization, sequence analyses and in situ hybridization, a clone encoding a rat homolog of yeast adenylyl cyclase-associated protein (CAP) was identified to be highly expressed in a subset of taste bud cells.

Profilin plays a role in cell elongation, cell shape maintenance, and flowering in Arabidopsis

Profilin (PFN) is an ubiquitous, low-M(r), actin-binding protein involved in the organization of the cytoskeleton of eukaryotes including higher plants. PFNs are encoded by a multigene family in Arabidopsis. We have analyzed in vivo functions of Arabidopsis PFN by generating transgenic plants carrying a 35S-PFN-1 or 35S-antisense PFN-1 transgene. Etiolated seedlings underexpressing PFN (PFN-U) displayed an overall dwarf phenotype with short hypocotyls whose lengths were 20% to 25% that of wild type (WT) at low temperatures. Light-grown PFN-U plants were smaller in stature and flowered early. Compared with equivalent cells in WT, most cells in PFN-U hypocotyls and roots were shorter, but more isodiametric, and microscopic observations of etiolated PFN-U hypocotyls revealed a rough epidermal surface. In contrast, light-grown seedlings overexpressing PFN had longer roots and root hair although etiolated seedlings overexpressing PFN were either the same size or slightly longer than WT seedlings. Transgenic seedlings harboring a PFN-1-GUS transgene directed expression in root and root hair and in a ring of cells at the elongating zone of the root tip. As the seedlings matured PFN-1-GUS was mainly expressed in the vascular bundles of cotyledons and leaves. Our results show that Arabidopsis PFNs play a role in cell elongation, cell shape maintenance, polarized growth of root hair, and unexpectedly, in determination of flowering time.

Histopathological study of venous aneurysms in patients with dural arteriovenous fistulas

OBJECT

Of all intracranial dural arteriovenous fistulas (DAVFs), those with cortical venous drainage associated with cortical venous ectasia or varices are predisposed to an aggressive course and produce progressive neurological symptoms or hemorrhages. The authors undertook a histological examination of venous aneurysms and arterialized veins in the proximity of these aneurysms that had been surgically removed in patients with DAVFs.

METHODS

Surgical specimens were obtained in eight patients. The excised venous aneurysms and the arterialized veins in their proximity were stained using hematoxylin and eosin, van Gieson's elastic, and Masson's trichrome stain. Immunostaining was also performed for alpha smooth-muscle actin, desmin, and factor VIII antigen. Five of the patients had presented with venous hypertension, and three had intracranial hemorrhages. The arterialized vein obtained in the proximity of the venous aneurysm exhibited local irregular intimal thickening; the internal elastic lamina (IEL) was grossly preserved. All venous aneurysms in patients with venous hypertension manifested medial thickening and local intimal thickening with loss of IEL; the thickness of the wall was relatively uniform. In contrast, the wall thickness of venous aneurysms in patients with hemorrhage was extremely irregular and there was no clear delineation between the media and the intima. In media with complete disappearance of IEL, there was scant muscle tissue.

CONCLUSIONS

Degenerative changes in venous aneurysms in patients with hemorrhage were much greater than in patients with venous hypertension, possibly because hemorrhages result from a more complicated interplay of anatomical, hemodynamic, and degenerative factors.

Asymmetric expression of antivin/lefty1 in the early chick embryo

Mammalian lefty and zebrafish antivin, highly related to lefty, are shown to be expressed asymmetrically and involved in the specification of the left body side of early embryos. We isolated a chick homologue of the antivin/lefty1 cDNA and studied its expression pattern during early chick development. We found that antivin/lefty1 is expressed asymmetrically on the left side of the prospective floorplate, notochord and lateral plate mesoderm of the chick embryo.

[Estimation of integral of input function for quantification of cerebral blood flow with N-isopropyl-p-[123I]iodoamphetamine using one-point venous blood sampling]

The present study was designed to investigate a possibility of substitution of the venous blood radioactivity counts sampled 26 min post injection for the octanol-extracted arterial blood radioactivity counts obtained at 5 min after the injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). Furthermore, we investigated whether the integral of input function can be estimated from the venous blood radioactivity counts sampled 26 min post injection and the whole-brain time-activity curves early after 123I-IMP injection. There was a good correlation between the arterial blood radioactivity counts sampled 5 min post injection (y) and those obtained at 26 min (r = 0.902; n = 91; y = 2.348x - 867.063). There was also a good correlation between the arterial (x) and venous blood radioactivity counts (y) sampled 26 min post injection (r = 0.954; n = 14; y = 0.761x + 924.336). The venous blood radioactivity counts sampled at 26 min (x) correlated well with the octanol-extracted arterial blood radioactivity counts sampled at 5 min (y) (r = 0.964; n = 32; y = 0.173x - 21.598). There was a good correlation between the integrals of input function obtained from the regression equation obtained above and the whole-brain time-activity curves acquired during 7 min post injection (y) and those obtained by 5-min continuous arterial blood sampling (x) (r = 0.965; n = 41; y = 0.957x + 2665.208). These results indicate that this noninvasive and simple method can estimate the integral of input function for quantification of cerebral blood flow using 123I-IMP.

An alternative approach to estimation of the brain perfusion index for measurement of cerebral blood flow using technetium-99m compounds

Cerebral blood flow (CBF) has been quantified non-invasively using the brain perfusion index (BPI) determined from radionuclide angiographic data generated by technetium-99m hexamethylpropylene amine oxime( )((99m)Tc-HMPAO) or technetium-99m ethyl cysteinate dimer( )((99m)Tc-ECD). The BPI is generally calculated using graphical analysis (GA). In the present study, BPI was measured using spectral analysis (SA), and its usefulness evaluated in comparison with GA. The BPI was calculated from the sum of spectral data obtained by SA. We applied this method to radionuclide angiographic data collected from the bilateral brain hemispheres of 20 patients with various brain diseases using (99m)Tc-HMPAO and from those of 20 patients using (99m)Tc-ECD. We also measured BPI using GA. The BPI values obtained by SA (BPI(S)) (x) and by GA (BPI(G)) (y) correlated closely (y=0.708x+0.038, r=0.945 for (99m)Tc-HMPAO and y=0.559x+0.093, r=0.931 for (99m)Tc-ECD). However, the BPI(G) values were underestimated by 22.9%+/-6.6% (mean+/-SD) for (99m)Tc-HMPAO and by 27.9%+/-7.5% for (99m)Tc-ECD as compared with the BPI(S) values. The extent of underestimation tended to increase with increasing BPI(S) values. These findings were considered to be a result of the BPI(G) values being affected by the first-pass extraction fraction of the tracer. We also compared the BPI(S) and BPI(G) values with those of CBF measured using N-isopropyl-p-[(123)I]iodoamphetamine (CBF(IMP)) in 16 patients (six for (99m)Tc-HMPAO and ten for (99m)Tc-ECD). Although both BPI(S) and BPI(G) values correlated significantly with the CBF(IMP) values, the correlation coefficient in BPI(S) was always better than that in BPI(G) (r=0.869 for (99m)Tc-HMPAO and r=0.929 for (99m)Tc-ECD in BPI(S), r=0.629 for (99m)Tc-HMPAO and r=0.856 for (99m)Tc-ECD in BPI(G)). These results suggest that SA can provide a more reliable BPI for quantifying CBF using (99m)Tc-HMPAO or (99m)Tc-ECD than the conventional method using GA. Our method will be useful especially when using a tracer with a low first-pass extraction fraction and/or when performing activation studies using pharmacological intervention.

A gustatory cyclic nucleotide-gated channels CNGgust, is expressed in the retina

Cyclic nucleotide-gated (CNG) channels are essential proteins that contribute to the intracellular signal transduction of the senses of sight and smell. Recently, we found a novel CNG channel (CNGgust) in rat taste buds, and demonstrated its possible involvement in taste signal transduction. In the present study, we used RT-PCR and immunostaining to prove that this gustatory CNG channel is expressed in the outer segments of rat cone photoreceptor cells. The study strongly suggests that the senses of taste and sight share, at least in part, a common signal transduction pathway.