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As a part of round robin analysis to develop a finite element elastic-plastic seismic analysis procedure for nuclear safety class 1 components, a series of parametric analyses was carried out on the simulated pressurizer surge line system model to investigate sensitivity of the analysis results to finite element analysis variables. The analysis on the surge line system model considered dynamic effect due to the seismic load corresponding to PGA 0.6 g and elastic-plastic material behavior based on the Chaboche combined hardening model. From the parametric analysis results, it was found that strains such as accumulated equivalent plastic strain and equivalent plastic strain are more sensitive to the analysis variables than von Mises effect stress. The parametric analysis results also identified that finite element density and ovalization option in the elbow elements have more significant effect on the analysis results than the other variables.

A fluorescent triple staining method was developed to stain the cytoplasm of neurons red, the nuclei of all kinds of cells, including neurons, blue and the nuclei of apoptotic neurons in cyan in the twelve ventral ganglia (VG) of the Bombyx mori ventral nerve cord. This differential staining method was used to distinguish between apoptotic and normal neurons in the suboesophageal ganglion (SOG), thoracic ganglia (TG)1 to TG3 and abdominal ganglia (AG)1 to AG8 and also determine the changes in the numbers of apoptotic neurons that occur during postembryonic development. In most of the VG tested, neuronal apoptosis was most marked during the period from the end of larval life to the mid pupal stage. The greatest number of apoptotic neurons was found in SOG of day-5 pupae, TG1 to TG3 and AG1 to AG4 of day-1 pupae, and AG5 to AG8 of day-4 pupae. In vivo injection of 20-hydroxyecdysone (20E) into day-8 5th instar larvae resulted in both a considerable increase in the number of apoptotic neurons and cleavage of procaspase-3 into caspase-3, which induced neuronal apoptosis in SOG and AG6 to AG8 in day-1 pupae, and a slight increase in the number of apoptotic neurons in TG1. In TG3 and AG4, however, it had little effect on the number of apoptotic neurons or cleavage of procaspase-3. Treatment of the VG of both day-8 5th instar larvae and day-2 pupae with protein synthesis inhibitors by in vivo injection triggered a significant inhibition of neuronal apoptosis and procaspase-3 cleavage in most of these ganglia in day-1 pupae and day-4 pupae, but not TG3 and AG4, in which there was little procaspase-3 and caspase-3. In vivo injection of caspase-8 and -3 inhibitors into day-8 5th instar larvae and day-2 pupae led to a substantial inhibition of neuronal apoptosis and of procaspase-3 cleavage in SOG, AG6 and TAG, but not in TG3 or AG4 of day-1 pupae and day-4 pupae. These findings suggest that neurons that die in SOG, TG1 and AG6 to AG8 in day-1 and -4 pupae may undergo apoptosis induced by the synthesis of a new protein and caspase-8- and -3-implicated signal transduction by the increase in titre of 20E in the haemolymph but not the neuronal aopotosis in TG3 and AG4. This study provides neurobiologists with valuable information and a means of studying neuronal apoptosis in the nervous system of insects.

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OBJECTIVE To investigate the effects of intravesical electrical stimulation (IVES) on bladder function and synaptic neurotransmission in the lumbosacral spinal cord in the spinalized rat, as the clinical benefits of IVES in patients with increased residual urine or reduced bladder capacity have been reported but studies on the mechanism of IVES have mainly focused on bladder Aδ afferents in central nervous system-intact rats. MATERIALS AND METHODS In all, 30 female Sprague-Dawley rats were divided equally into three groups: normal control rats, sham-stimulated spinalized rats and IVES-treated spinalized rats. IVES was started 5 weeks after spinal cord injury (SCI) and was performed 20 min a day for 5 consecutive days. At 7 days after IVES, conscious filling cystometry was performed. Sections from the L6 and S1 spinal cord segments were examined forn-methyl-d-aspartic acid receptor 1 (NMDAR1) subunit and γ-aminobutyric acid (GABA) immunoactivity. RESULTS In IVES-treated spinalized rats, the number and maximal pressure of nonvoiding detrusor contractions were significantly less than in sham-stimulated spinalized rats. The mean maximal voiding pressure was also lower in IVES-treated than in sham-stimulated spinalized rats. IVES significantly reduced the interval between voiding contractions compared with the untreated spinalized rats. There was an overall increase in NMDAR1 immunoactivity after SCI, which was significantly lower in IVES-treated spinalized rats. Immunoactivity of GABA after SCI was significantly lower than in the control group and was significantly higher in IVES-treated spinalized rats. CONCLUSION Our results suggest that IVES might affect voiding contractions in addition to inhibiting C-fibre activity and that IVES seems to have a more complex effect on the bladder control pathway. For synaptic neurotransmission in the spinal cord, IVES could possibly shift the balance between excitation and inhibition towards inhibition. [ABSTRACT FROM AUTHOR]

Purpose: c-fos expression in spinal neurons that are activated by lower urinary tract stimulation are not organ specific. In this experiment, we demonstrated changes of c-fos expression in bladder-specific preganglionic neurons (PGNs) and interneurons using pseudorabies virus (PRV). Materials and Methods: Forty Sprague-Dawley rats were used. We identified the neuronal pathway associated with the bladder by injecting PRV into the detrusor. An immunohistochemical method was used to stain Fos-protein encoded by the c-fos gene. Immunofluorescent staining for PRV was performed to evaluate changes in bladder-specific spinal neurons. Results: Immunofluorescent staining with choline acetyltransferase (ChAT) revealed that the sacral parasympathetic nucleus (SPN) regions contained 9.8 PGNs/section. In rats with chronic spinal cord injury by intravesical saline instillation, 82.4 ± 10.3% of PGNs in SPN exhibited Fos-immunoreactive (IR). Two and a half days after PRV infection, PRV-IR PGNs were observed at 5.4 PGNs/section, and 2.7 ± 1.6% of them exhibited Fos-IR. Unlike ChAT-IR PGNs, PRV-IR PGNs are bladder-specific neurons and PRV-IR and Fos-IR cells found in the back of PRV-IR PGNs are bladder-specific interneurons. Three days after PRV infection, we observed many PRV-IR and Fos-IR cells in the dorsal commissure. These neurons are interneurons distributed in the bladder. Conclusion: We confirmed that in chronic spinal cord injury, the patterns of c-fos expression in bladder-specific spinal neurons were similar to those in voiding-reflex related spinal neurons, which had already been demonstrated earlier. We believe that our methodology can be applied to study interactions between voiding and other organs as well, such as the urethra and prostate. [ABSTRACT FROM AUTHOR]

Abstract  Myb genes are a family of transcription factors and have been implicated in the control of the proliferation and differentiation of normal and transformed cells. c-Myb is the best characterized member of the myb family. In the present study, we investigated age-dependent changes of c-myb immunoreactivity, its protein and mRNA level in the hippocampus proper (CA1–3 regions) at various age stages in gerbils. In the postnatal month 1 (PM 1) group, c-myb immunoreactivity was detected in non-pyramidal neurons of the strata oriens and radiatum as well as in pyramidal neurons of the stratum pyramidale. At PM 3, c-myb immunoreactivity and its protein level were similar to those at PM 1. Thereafter, c-myb immunoreactivity and its protein level were increased with time. In the PM 24 group, c-myb immunoreactivity, its protein and mRNA levels were highest. These results suggest that the significant increase of c-myb immunoreactivity, protein and mRNA levels in the aged hippocampus may be associated with neuronal aging. [ABSTRACT FROM AUTHOR]

Abstract  Age-dependent studies on oligodendrocytes, which are the myelinating cells in the central nervous system, have been relatively less investigated. We examined age-dependent changes in Rip immunoreactivity and its protein level in the gerbil hippocampus during normal aging using immunohistochemistry and Western blot analysis with Rip antibody, an oligodendrocyte marker. Rip immunoreactivity and its protein level in the hippocampal CA1 region significantly increased at postnatal month 3 (PM 3). Thereafter, they decreased in the hippocampal CA1 region with age. At PM 24, Rip immunoreactive processes in the hippocampal CA1 region markedly decreased in the stratum radiatum. In the hippocampal CA2/3 region and dentate gyrus, the pattern of changes in Rip immunoreactivity and its protein level was similar to those in the hippocampal CA1 region; however, no significant changes were found in the CA2/3 region and dentate gyrus at various age stages. These results indicate that Rip immunoreactivity and protein level in the hippocampal CA1 region decreases significantly at PM 24 compared to the CA2/3 region and dentate gyrus. [ABSTRACT FROM AUTHOR]

Because the dopaminergic pathways in the midbrain have been closely associated with serious neuropsychiatric disorders, the elucidation of the mechanisms underlying dopaminergic neuronal development should provide some important clues for related disorders. In mice lacking the dopamine D2 receptor (D2R-/-), stereological cell counting analysis showed that the number of mesencephalic tyrosine hydroxylase (TH) cells was significantly low during ontogeny, compared with that observed in wild-type (WT) mice, thereby indicating an alteration in dopaminergic neuronal development in the absence of D2R. The results of immunohistochemical and reverse transcription-PCR analyses revealed that the expression of Nurr1, an orphan nuclear receptor, as well as Ptx3 expression, was selectively reduced in D2R-/- mice during the embryonic stage. A reporter gene assay using the Nur response element linked to the luciferase reporter gene indicated that the stimulation of D2R results in the activation of the Nurr1-mediated reporter gene. This D2R-mediated Nur response element-dependent transcriptional activity was regulated via the activation of extracellular signal-regulated kinase (ERK). Furthermore, quinpirole treatment was shown to elicit an increase in the number of TH-positive neurons, as well as the neuritic extension of TH neurons, coupled with ERK activation and Nurr1 activation in the TH-positive neurons in primary mesencephalic cultures from WT mice. However, this regulation was not detected in the D2R-/- mice. These results suggest that signaling through D2R in association with Nurr1 using ERK, plays a critical role in mesencephalic dopaminergic neuronal development. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the secretion of brain-derived neurotrophic factor (BDNF)-like neuropeptide in the silkworm, Bombyx mori , by using immunocytochemical techniques on the brain and retrocerebral complex of fifth instar larvae. In the brain, four pairs of median neurosecretory cell (MNC) bodies and six pairs of lateral neurosecretory cell (LNC) bodies had distinct immunoreactivities to this peptide, suggesting that this peptide is produced from two types of brain neuron. These reactivities were much stronger in the MNC than in the LNC. Labeled MNC projected their axons into the contralateral corpora allata, to which axons of labeled MNC were eventually innervated, through decussation in the median region, contralateral nerve corporis cardiaci I and nerve corpora allata I. Labeled LNC extended their axons into the ipsilateral corpora allata to be innervated through the ipsilateral nerve corporis cardiaci II and nerve corpora allata I. These results suggest that BDNF is secreted as a neurohormone from MNC and LNC of the brain into the corpora allata. [ABSTRACT FROM AUTHOR]

A cuticle protein gene, AyCP12, from the Japanese oak silkmoth, Antheraea yamamai, was isolated and characterized. The gene spans 1107 bp and consists of one intron and two exons coding for a 112 amino acid polypeptide with a predicted molecular mass of 12,163 Da and a pI of 4.4. The AyCP12 protein contained a type-specific consensus sequence identifiable in other insect cuticle proteins and the deduced amino acid sequence of the AyCP12 cDNA is most homologous to another silkmoth, A. pernyi, cuticle protein ApCP13 (82% protein sequence identity). Northern blot analysis revealed that AyCP12 showed the epidermis-specific expression. [ABSTRACT FROM AUTHOR]

Effects of 20-hydroxyecdysone and serotonin on the morphological development and the survival of antennal lobe neurons from day-2 pupal brains of the silk moth Bombyx mori were investigated in vitro. Four morphologically distinct neuronal types could be identified in the cultured antennal lobe neurons: unipolar, bipolar, multi-polar and projection neurons. Antennal lobe neurons in culture with 20-hydroxyecdysone and serotonin showed different patterns of the morphological development from those described in Manduca sexta. Projection neurons extend their neurites remarkably by 20-hydroxyecdysone in B, mort, but there is no extension from antennal lobe neurons in M, sexta. Multi-polar neurons conspicuously increase only formation of new branches from their primary neurites by serotonin in B. mori, but there are both extension and branching of the neurites in M. sexta. On day-5, antennal lobe neurons in lower titers of 20-hydroxyecdysone had significantly higher survival rates than those in higher titers. Neurons cultured for 7 days at different levels of 20-hydroxyecdysone generally showed significantly lower survival rates than neurons cultured for 5 days under the same conditions. [ABSTRACT FROM AUTHOR]

Presents information on a study which utilized polyclonal antisera to Manduca sexta allatotropin and allatostatin to localize allatotropin- and allatostatin-immunoreactivities in the central nervous system of larvae, pupae and adults from the silk moth Bombyx mori. Materials and methods; Results; Discussion.

In stem cell biology, there is a growing need for advanced technologies that may help to unravel the molecular mechanisms of self-renewal and differentiation. Proteomics, the comprehensive analysis of proteins, is such an emerging technique. To facilitate interactions between specialists in proteomics and stem cell biology, a new initiative has been undertaken, supported by the Human Proteome Organization (HUPO) and the International Society for Stem Cell Research (ISSCR). Here we present the Proteome Biology of Stem Cells Initiative (PBSCI) and report on its goals and future activities. [ABSTRACT FROM AUTHOR]

The Forkhead box O (FoxO) transcription factors, including FoxO1, FoxO3a, and FoxO4, have been implicated in the regulation of several biological processes, including stress resistance, metabolism, and apoptosis. In the present study, FoxO1 and FoxO3a patterns and their role in the regulation of the insulin signalling and mitogen-activated protein kinase (MAPK) pathways were analyzed after starvation in the fat body cells of the silkworm, Bombyx mori. FoxO1 and FoxO3a are localized to the nuclei. It was found that the levels of the insulin receptor and phosphoryated kinase Akt (p-Akt) increased when the animals ceased feeding. Starvation conditions caused a decrease in extracellular-signal-regulated kinase (ERK) phosphorylation, and an increase in c-Jun N-terminal kinase (JNK) and p38 (MAP kinase) phosphorylation. This implies that the FoxO transcription factors are activated by starvation and that starvation leads to changes in the insulin signalling and MAPK pathways in B. mori. These results strongly suggest that the FoxO transcription factor may be involved in the regulation of the insulin signalling and MAPK pathways in B. mori. As such, the findings provide molecular entomologists with valuable information on the molecular mechanism of the signalling pathways in postembryonic development ofthe silkworm. [ABSTRACT FROM AUTHOR]

The pattern and signal transduction of neuronal apoptosis in the brain of the silk moth, Bombyx mori, during postembryonic life, were characterized. Peak numbers of apoptotic neurons were detected in 4 day old 4th instar larvae, 9 day old 5th instar larvae and 4 day old pupae, indicating three waves of neuronal apoptosis during postembryonic development. Most of the apoptotic neurons were in the lateral portions of the brain. No apoptotic neurons were detected in 1 day old 1st instar larvae or in 7 day old pupae to 1 day old adults. Injection of 20-hydroxyecdysone (20E) into larvae resulted in a substantial increase in the brain in both neuronal apoptosis and cleavage of procaspases-8 and -3 into caspases-8 and -3. However, the injection of larvae with actinomycin D or cycloheximide inhibited death of pre-apoptotic neurons. Both the cleavage of procaspases-8 and -3 and death of pre-apoptotic neurons were inhibited by a general caspase inhibitor and caspase-8 and -3 inhibitors injected into larvae. These results suggest that 20E triggered the synthesis of a new protein that, in turn, induces cleavage of procaspases-8 and -3 into caspases-8 and -3. These caspases are prerequisites for neuronal apoptosis in postembryonic brains. [ABSTRACT FROM AUTHOR]