Conditional deficiency of Rho-associated kinases disrupts endothelial cell junctions and impairs respiratory function in adult mice

The Ras homology (Rho) family of GTPases serves various functions, including promotion of cell migration, adhesion, and transcription, through activation of effector molecule targets. One such pair of effectors, the Rho-associated coiled-coil kinases (ROCK1 and ROCK2), induce reorganization of actin cytoskeleton and focal adhesion through substrate phosphorylation. Studies on ROCK knockout mice have confirmed that ROCK proteins are essential for embryonic development, but their physiological functions in adult mice remain unknown. In this study, we aimed to examine the roles of ROCK1 and ROCK2 proteins in normal adult mice. Tamoxifen (TAM)-inducible ROCK1 and ROCK2 single and double knockout mice (ROCK1flox/flox and/or ROCK2flox/flox;Ubc-CreERT2) were generated and administered a 5-day course of TAM. No deaths occurred in either of the single knockout strains, whereas all of the ROCK1/ROCK2 double conditional knockout mice (DcKO) had died by Day 11 following the TAM course. DcKO mice exhibited increased lung tissue vascular permeability, thickening of alveolar walls, and a decrease in percutaneous oxygen saturation compared with noninducible ROCK1/ROCK2 double-floxed control mice. On Day 3 post-TAM, there was a decrease in phalloidin staining in the lungs in DcKO mice. On Day 5 post-TAM, immunohistochemical analysis also revealed reduced staining for vascular endothelial (VE)-cadherin, β-catenin, and p120-catenin at cell-cell contact sites in vascular endothelial cells in DcKO mice. Additionally, VE-cadherin/β-catenin complexes were decreased in DcKO mice, indicating that ROCK proteins play a crucial role in maintaining lung function by regulating cell-cell adhesion.

Assessing the Safety of Mechanically Fibrillated Cellulose Nanofibers (fib-CNF) via Toxicity Tests on Mice: Single Intratracheal Administration and 28 Days' Oral Intake

Mechanically fibrillated cellulose nanofibers, known as fib-CNF (fiber length: 500 nm; diameter: 45 nm), are used in composites and as a natural thickener in foods. To evaluate their safety, we conducted a 28-day study in mice with inhalation exposure at 0.2 mg/body and oral administration of 400 mg/kg/day. Inhalation exposure to fib-CNF caused transient weight loss, changes in blood cell counts, and increased lung weights. These changes were attributed to adaptive responses. The oral administration of fib-CNF for 28 days resulted in no apparent toxic effects except for a slight decrease in platelet counts. The fib-CNF administration using the protocols studied appears to be safe in mice.

IQSEC3 Deletion Impairs Fear Memory Through Upregulation of Ribosomal S6K1 Signaling in the Hippocampus

BACKGROUND

IQSEC3, a gephyrin-binding GABAergic (gamma-aminobutyric acidergic) synapse-specific guanine nucleotide exchange factor, was recently reported to regulate activity-dependent GABAergic synapse maturation, but the underlying signaling mechanisms remain incompletely understood.

METHODS

We generated mice with conditional knockout (cKO) of Iqsec3 to examine whether altered synaptic inhibition influences hippocampus-dependent fear memory formation. In addition, electrophysiological recordings, immunohistochemistry, and behavioral assays were used to address our question.

RESULTS

We found that Iqsec3-cKO induces a specific reduction in GABAergic synapse density, GABAergic synaptic transmission, and maintenance of long-term potentiation in the hippocampal CA1 region. In addition, Iqsec3-cKO mice exhibited impaired fear memory formation. Strikingly, Iqsec3-cKO caused abnormally enhanced activation of ribosomal P70-S6K1-mediated signaling in the hippocampus but not in the cortex. Furthermore, inhibiting upregulated S6K1 signaling by expressing dominant-negative S6K1 in the hippocampal CA1 of Iqsec3-cKO mice completely rescued impaired fear learning and inhibitory synapse density but not deficits in long-term potentiation maintenance. Finally, upregulated S6K1 signaling was rescued by IQSEC3 wild-type, but not by an ARF-GEF (adenosine diphosphate ribosylation factor-guanine nucleotide exchange factor) inactive IQSEC3 mutant.

CONCLUSIONS

Our results suggest that IQSEC3-mediated balanced synaptic inhibition in hippocampal CA1 is critical for the proper formation of hippocampus-dependent fear memory.

Inhibition of low-density lipoprotein uptake by Helicobacter pylori virulence factor CagA

Helicobacter pylori (H. pylori) infection mainly causes gastroduodenal diseases, including chronic gastritis, peptic ulcer disease and gastric cancer. In recent years, several studies have demonstrated that infection with H. pylori, especially strains harboring the virulence factor CagA (cytotoxin-associated gene A), contribute to the development of non-gastric systemic diseases, including hypercholesterolemia and atherosclerotic cardiovascular diseases. However, mechanisms underlying this association has not been defined. In this study, we carried out a large-scale genetic screen using Drosophila and identified a novel CagA target low-density lipoprotein receptor (LDLR), which aids in the clearance of circulating LDL. We showed that CagA physically interacted with LDLR via its carboxy-terminal region and inhibited LDLR-mediated LDL uptake into cells. Since deficiency of LDLR-mediated LDL uptake has been known to increase plasma LDL and accelerate atherosclerosis, our findings may provide a novel mechanism for the association between infection with CagA-positive H. pylori and hypercholesterolemia leading to atherosclerotic cardiovascular diseases.

Downregulation of WDR20 due to loss of 14q is involved in the malignant transformation of clear cell renal cell carcinoma

Previously, we reported that genomic loss of 14q occurs more frequently in high-grade than in low-grade clear cell renal cell carcinomas (ccRCCs), and has a significant impact on the levels of expression of genes located in this region, suggesting that such genes may be involved in the malignant transformation of ccRCCs. Here, we found that six of the genes located in the minimal common region of 14q loss were significantly downregulated in high-grade ccRCCs due to copy number loss. Using a dataset from The Cancer Genome Atlas Research Network, we found that downregulation of one of these six genes, WDR20, was significantly associated with poorer outcome in patients with ccRCC, suggesting that WDR20 downregulation may be involved in the malignant transformation of ccRCCs. In functional assays, exogenous WDR20 significantly inhibited the growth of RCC cell lines and induced apoptosis. Interestingly, the phosphorylation levels of ERK and protein kinase B/AKT, which reportedly contribute to the malignant phenotype of RCC cells, were clearly reduced by exogenous expression of WDR20. Thus, our data suggest that downregulation of WDR20 due to 14q loss may be involved in the malignant transformation of ccRCCs, in part through activation of the ERK and protein kinase B/AKT pathways.

Mechanisms of gene targeting in higher eukaryotes

Targeted genome modifications using techniques that alter the genomic information of interest have contributed to multiple studies in both basic and applied biology. Traditionally, in gene targeting, the target-site integration of a targeting vector by homologous recombination is used. However, this strategy has several technical problems. The first problem is the extremely low frequency of gene targeting, which makes obtaining recombinant clones an extremely labor intensive task. The second issue is the limited number of biomaterials to which gene targeting can be applied. Traditional gene targeting hardly occurs in most of the human adherent cell lines. However, a new approach using designer nucleases that can introduce site-specific double-strand breaks in genomic DNAs has increased the efficiency of gene targeting. This new method has also expanded the number of biomaterials to which gene targeting could be applied. Here, we summarize various strategies for target gene modification, including a comparison of traditional gene targeting with designer nucleases.

Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs

We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

The histone demethylase Fbxl11/Kdm2a plays an essential role in embryonic development by repressing cell-cycle regulators

Methylation and de-methylation of histone lysine residues play pivotal roles in mammalian early development; these modifications influence chromatin architecture and regulate gene transcription. Fbxl11 (F-box and leucine-rich repeat 11)/Kdm2a is a histone demethylase that selectively removes mono- and di-methylation from histone H3K36. Previously, two other histone H3K36 demethylases (Jmjd5 or Fbxl10) were analyzed based on the phenotypes of the corresponding knockout (KO) mice; the results of those studies implicated H3K36 demethylases in cell proliferation, apoptosis, and senescence (Fukuda et al., 2011; Ishimura et al., 2012). To elucidate the physiological role of Fbxl11, we generated and examined Fbxl11 KO mice. Fbxl11 was expressed throughout the body during embryogenesis, and the Fbxl11 KO mice exhibited embryonic lethality at E10.5-12.5, accompanied with severe growth defects leading to reduced body size. Furthermore, knockout of Fbxl11 decreased cell proliferation and increased apoptosis. The lack of Fbxl11 resulted in downregulation of the Polycomb group protein (PcG) Ezh2, PcG mediated H2A ubiquitination and upregulation of the cyclin-dependent kinase inhibitor p21Cip1. Taken together, our findings suggest that Fbxl11 plays an essential role in embryonic development and homeostasis by regulating cell proliferation and survival.

Botch promotes neurogenesis by antagonizing Notch

Regulation of self-renewal and differentiation of neural stem cells is still poorly understood. Here we investigate the role of a developmentally expressed protein, Botch, which blocks Notch, in neocortical development. Downregulation of Botch in vivo leads to cellular retention in the ventricular and subventricular zones, whereas overexpression of Botch drives neural stem cells into the intermediate zone and cortical plate. In vitro neurosphere and differentiation assays indicate that Botch regulates neurogenesis by promoting neuronal differentiation. Botch prevents cell surface presentation of Notch by inhibiting the S1 furin-like cleavage of Notch, maintaining Notch in the immature full-length form. Understanding the function of Botch expands our knowledge regarding both the regulation of Notch signaling and the complex signaling mediating neuronal development.

Polypyrimidine tract-binding protein regulates the cell cycle through IRES-dependent translation of CDK11(p58) in mouse embryonic stem cells

Polypyrimidine tract-binding protein (PTB/PTBP1/hnRNP I) is a member of the heterogeneous nuclear ribonucleoprotein family that binds specifically to pyrimidine-rich sequences of RNAs. Although PTB is a multifunctional protein involved in RNA processing and internal ribosome entry site (IRES)-dependent translation, the role of PTB in early mouse development is unclear. Ptb knockout mice exhibit embryonic lethality shortly after implantation and Ptb-/- embryonic stem (ES) cells have a severe proliferation defect that includes a prolonged G2/M phase. The present study shows that PTB promotes M phase progression by the direct repression of CDK11(p58) IRES activity in ES cells. The protein expression and IRES activity of CDK11(p58) in Ptb-/- ES cells is higher than that of wild-type ES cells, indicating that PTB is involved in the repression of CDK11(p58) expression through IRES-dependent translation in ES cells. Interestingly, CDK11(p58) IRES activity is activated by upstream of N-Ras (UNR) in 293T and NIH3T3 cells, whereas UNR is not present in the Cdk11 mRNA-protein complex in ES cells. In addition, PTB interacts directly with the IRES region of CDK11(p58) in ES cells. These results suggest that PTB regulates the precise expression of CDK11(p58) through direct interaction with CDK11(p58) IRES and promotes M phase progression in ES cells.

BMP-induced REST regulates the establishment and maintenance of astrocytic identity

Astrocyte differentiation and maintenance is promoted by BMP signaling, which induces REST/NRSF to repress neuronal genes.

Once they have differentiated, cells retain their individual character and repress genes that are specifically expressed in other cell lineages, but how alternative fate choice is restricted during and/or after differentiation remains unclear. In the mammalian central nervous system, neurons, astrocytes, and oligodendrocytes are generated throughout life from common tripotent neural progenitor cells (NPCs). Bone morphogenetic proteins (BMPs) are well-known astrocyte-inducing cytokines. We show here that the expression of a transcriptional repressor, RE1 silencer of transcription (REST)/neuron-restrictive silencer factor (NRSF), is up-regulated and sustained by BMP signal activation in the course of astrocytic differentiation of NPCs, and restricts neuronal differentiation. We further show that, in differentiated astrocytes, endogenous REST/NRSF associates with various neuronal genes and that disruption of its function resulted in their derepression, thereby explaining how ectopic neuronal gene expression is prevented in cells with astrocytic traits. Collectively, our results suggest that REST/NRSF functions as a molecular regulator of the nonneuronal phenotype in astrocytes.

Notch-Hes1 pathway contributes to the cochlear prosensory formation potentially through the transcriptional down-regulation of p27Kip1

The Notch signaling pathway has a crucial role in the differentiation of hair cells and supporting cells by mediating "lateral inhibition" via the ligands Delta-like1 (Dll1) and Jagged2 (Jag2) and the effectors Hes1 and Hes5 during mammalian inner ear development. Recently, another Notch ligand, Jagged1 (Jag1)-dependent Notch activation, has been revealed to be important for the determination of the prosensory region in the earlier stage before cell differentiation. However, little is known about the effectors of the Notch pathway in this context. P27(Kip1), a cyclin-dependent kinase inhibitor, is also known to demarcate the prosensory region in the cochlear primordium, which consists of the sensory progenitors that have completed their terminal mitoses. Hes1 reportedly promotes precursor cell proliferation through the transcriptional down-regulation of p27(Kip1) in the thymus, liver, and brain. In this study, we observed Hes1 as a mediator between the Notch signaling pathway and the regulation of proliferation of sensory precursor cells by p27(Kip1) in the developing cochlea. We showed that Hes1, but not Hes5, was weakly expressed at the time of onset of p27(Kip1). The expression pattern of Hes1 prior to cell differentiation was similar to that of activated Notch1. P27(Kip1) was up-regulated and BrdU-positive S-phase cells were reduced in the developing cochlear epithelium of Hes1 null mice. These results suggest that the Notch-Hes1 pathway may contribute to the adequate proliferation of sensory precursor cells via the potential transcriptional down-regulation of p27(Kip1) expression and play a pivotal role in the correct prosensory determination.

Polypyrimidine tract-binding protein is essential for early mouse development and embryonic stem cell proliferation

Polypyrimidine tract-binding protein (PTB) is a widely expressed RNA-binding protein with multiple roles in RNA processing, including the splicing of alternative exons, mRNA stability, mRNA localization, and internal ribosome entry site-dependent translation. Although it has been reported that increased expression of PTB is correlated with cancer cell growth, the role of PTB in mammalian development is still unclear. Here, we report that a homozygous mutation in the mouse Ptb gene causes embryonic lethality shortly after implantation. We also established Ptb(-/-) embryonic stem (ES) cell lines and found that these mutant cells exhibited severe defects in cell proliferation without aberrant differentiation in vitro or in vivo. Furthermore, cell cycle analysis and a cell synchronization assay revealed that Ptb(-/-) ES cells have a prolonged G(2)/M phase. Thus, our data indicate that PTB is essential for early mouse development and ES cell proliferation.

Notch signaling activation in human embryonic stem cells is required for embryonic, but not trophoblastic, lineage commitment

The Notch signaling pathway plays important roles in cell-fate determination during embryonic development and adult life. In this study, we focus on the role of Notch signaling in governing cell-fate choices in human embryonic stem cells (hESCs). Using genetic and pharmacological approaches, we achieved both blockade and conditional activation of Notch signaling in several hESC lines. We report here that activation of Notch signaling is required for undifferentiated hESCs to form the progeny of all three embryonic germ layers, but not trophoblast cells. In addition, transient Notch signaling pathway activation enhanced generation of hematopoietic cells from committed hESCs. These new insights into the roles of Notch in hESC-fate determination may help to efficiently direct hESC differentiation into therapeutically relevant cell types.

Cell-cycle-specific nestin expression coordinates with morphological changes in embryonic cortical neural progenitors

During brain development, neural progenitor cells extend across the thickening brain wall and undergo mitosis. To understand how these two completely different cellular events are coordinated, we focused on the transcription pattern of the nestin gene (Nes), which encodes an intermediate filament protein strongly expressed in neural progenitor cells. To visualize nestin expression in vivo, we generated transgenic mice that expressed a destabilized fluorescent protein under the control of Nes second intronic enhancer (E/nestin:dVenus). During the neurogenic stage, when the brain wall thickens markedly, we found that nestin was regulated in a cell-cycle-dependent manner. Time-lapse imaging showed that nestin gene expression was upregulated during G1-S phase, when the neural progenitor cells elongate their fibers. However, nestin expression dramatically declined in G2-M phase, when progenitor cells round up to undergo mitosis. The cell-cycle-dependent phosphorylation of an upstream regulator class III POU transcription factor (Pou3f2 or Brn2) reduced its binding activity to the nestin core enhancer element and was therefore responsible for the decreased Nes transcription in G2-M phase. Collectively, these findings demonstrate precisely orchestrated gene regulation that correlates with the 3D morphological changes in neural progenitor cells in vivo.

Differential Notch signalling distinguishes neural stem cells from intermediate progenitors

During brain development, neurons and glia are generated from a germinal zone containing both neural stem cells (NSCs) and more limited intermediate neural progenitors (INPs). The signalling events that distinguish between these two proliferative neural cell types remain poorly understood. The Notch signalling pathway is known to maintain NSC character and to inhibit neurogenesis, although little is known about the role of Notch signalling in INPs. Here we show that both NSCs and INPs respond to Notch receptor activation, but that NSCs signal through the canonical Notch effector C-promoter binding factor 1 (CBF1), whereas INPs have attenuated CBF1 signalling. Furthermore, whereas knockdown of CBF1 promotes the conversion of NSCs to INPs, activation of CBF1 is insufficient to convert INPs back to NSCs. Using both transgenic and transient in vivo reporter assays we show that NSCs and INPs coexist in the telencephalic ventricular zone and that they can be prospectively separated on the basis of CBF1 activity. Furthermore, using in vivo transplantation we show that whereas NSCs generate neurons, astrocytes and oligodendrocytes at similar frequencies, INPs are predominantly neurogenic. Together with previous work on haematopoietic stem cells, this study suggests that the use or blockade of the CBF1 cascade downstream of Notch is a general feature distinguishing stem cells from more limited progenitors in a variety of tissues.

Mapping of notch activation during cochlear development in mice: implications for determination of prosensory domain and cell fate diversification

Recent chick experiments have shown that Notch signaling plays context-dependent distinct roles in inner ear development: initially, Notch activity confers a prosensory character on groups of cells by "lateral induction"; subsequently, it is involved in the establishment of fine-graded patterns of hair cells and supporting cells by "lateral inhibition." However, the spatiotemporal pattern of Notch activation in situ during mammalian inner ear development has not been investigated. In this study, we detected the expression patterns of the activated form of Notch1 (actN1) as well as those of endogenous Notch1, Jagged1 (Jag1), and Math1. ActN1 was detected by immunohistochemistry using an antibody that specifically recognizes the processed form of the intracellular domain of Notch1 cleaved by presenilin/gamma-secretase activity. Between embryonic days (E)12.5 and E14.5, actN1 was weakly detected mainly in the medial region of cochlear epithelium, where Jag1-immunoreactivivty (IR) was also observed. Jag1-IR gradually became stronger in a more sharply defined area, finally becoming localized in supporting cells, while actN1 was detected in an overlapping area. Thus, a positive feedback loop was assumed to exist between the expression of Jag1 and actN1. In addition, actN1 started to be strongly expressed in the cells surrounding Math1-positive hair cell progenitors between E14.5 and E15.5. Strong actN1-IR continued in both a supporting cell lineage and in the greater epithelial ridge during the perinatal stage but ended by P7, suggesting that Notch1 activation may initially demarcate a prosensory region in the cochlear epithelium and then inhibit progenitor cells from becoming hair cells via classical "lateral inhibition."

Distinct functions of human numb isoforms revealed by misexpression in the neural stem cell lineage in the Drosophila larval brain

Mammalian Numb (mNumb) has multiple functions and plays important roles in the regulation of neural development, including maintenance of neural progenitor cells and promotion of neuronal differentiation in the central nervous system (CNS). However, the molecular bases underlying the distinct functions of Numb have not yet been elucidated. mNumb, which has four splicing isoforms, can be divided into two types based on the presence or absence of an amino acid insert in the proline-rich region (PRR) in the C-terminus. It has been proposed that the distinct functions of mNumb may be attributable to these two different types of isoforms. In this study, we used the outer optic anlage (OOA) of the Drosophila larval brain as an assay system to analyze the functions of these two types of isoforms in the neural stem cells, since the proliferation pattern of neuroepithelial (NE) stem cells in the OOA closely resembles that of the vertebrate neural stem/progenitor cells. They divide to expand the progenitor cell pool during early neurogenesis and to produce neural precursors/neurons during late neurogenesis. Clonal analysis in the OOA allows one to discriminate between the NE stem cells, which divide symmetrically to expand the progenitor pool, and the postembryonic neuroblasts (pNBs), which divide asymmetrically to produce neural precursors (ganglion mother cells), each of which divides once to produce two neurons. We found that in the OOA, the human Numb isoform with a long PRR domain (hNumb-PRRL), which is mainly expressed during early neurogenesis in the mouse CNS, promotes proliferation of both NE cells and pNBs without affecting neuronal differentiation, while the other type of hNumb isoform with a short PRR domain (hNumb-PRRS), which is expressed throughout neurogenesis in the mouse embryonic CNS, inhibits proliferation of the stem cells and promotes neuronal differentiation. We also found that hNumb-PRRS, a functional homologue of Drosophila Numb, more strongly decreases the amount of nuclear Notch than hNumb-PRRL, and could antagonize Notch functions probably through endocytic degradation, suggesting that the two distinct types of hNumb isoforms could contribute to different phases of neurogenesis in the mouse embryonic CNS.

Collinear to spiral spin transformation without changing the modulation wavelength upon ferroelectric transition in Tb1-xDyxMnO3

Lattice modulation and magnetic structures in magnetoelectric compounds Tb1-xDyxMnO3 have been studied around the ferroelectric (FE) Curie temperature TC by x-ray and neutron diffraction. Temperature-independent modulation vectors through TC are observed for the compounds with 0.50 <or=x<or=0.68. This indicates that ferroelectricity with a polarization (P) along the c axis in the RMnO3 series cannot be ascribed to such an incommensurate-commensurate transition of an antiferromagnetic order as was previously anticipated. A neutron diffraction study with x=0.59 shows that the FE transition is accompanied by the transformation of the Mn-spin alignment from sinusoidal (collinear) antiferromagnetism into a transverse-spiral structure. The observed spiral structure below TC is expected to produce P along the c axis with the "inverse" Dzialoshinski-Moriya interaction, which is consistent with observation.

Role of numb in dendritic spine development with a Cdc42 GEF intersectin and EphB2

Numb has been implicated in cortical neurogenesis during nervous system development, as a result of its asymmetric partitioning and antagonizing Notch signaling. Recent studies have revealed that Numb functions in clathrin-dependent endocytosis by binding to the AP-2 complex. Numb is also expressed in postmitotic neurons and plays a role in axonal growth. However, the functions of Numb in later stages of neuronal development remain unknown. Here, we report that Numb specifically localizes to dendritic spines in cultured hippocampal neurons and is implicated in dendritic spine morphogenesis, partially through the direct interaction with intersectin, a Cdc42 guanine nucleotide exchange factor (GEF). Intersectin functions as a multidomain adaptor for proteins involved in endocytosis and cytoskeletal regulation. Numb enhanced the GEF activity of intersectin toward Cdc42 in vivo. Expression of Numb or intersectin caused the elongation of spine neck, whereas knockdown of Numb and Numb-like decreased the protrusion density and its length. Furthermore, Numb formed a complex with EphB2 receptor-type tyrosine kinase and NMDA-type glutamate receptors. Knockdown of Numb suppressed the ephrin-B1-induced spine development and maturation. These results highlight a role of Numb for dendritic spine development and synaptic functions with intersectin and EphB2.

Noxious cold stimulation induces mitogen-activated protein kinase activation in transient receptor potential (TRP) channels TRPA1- and TRPM8-containing small sensory neurons

Two cold-sensitive transient receptor potential (TRP) channels, TRPA1 and TRPM8, have been identified and considered interesting because of their possible roles in thermosensation, nociception and other functions. Recently, we have reported that the phosphorylation of extracellular signal-regulated protein kinase and p38 mitogen-activated protein kinase occurred in primary afferent neurons in response to noxious heat stimulation of the peripheral tissue, i.e. activity-dependent activation of extracellular signal-regulated protein kinase and p38 in dorsal root ganglion neurons. In the present study, we investigated the phosphorylation of extracellular signal-regulated protein kinase, p38, and c-Jun N-terminal kinase in the rat dorsal root ganglion by cold stimulation using immunohistochemistry. Cold stimuli (28-4 degrees C) were applied by immersion of the hind paw into a water bath (six times of 10 s stimulation and 10 s interval, total 2 min). Noxious cold stimulation induced phosphorylated-extracellular signal-regulated protein kinase and phosphorylated-p38, but not phosphorylated-c-Jun N-terminal kinase, in small to medium diameter sensory neurons with a peak at 2 min after stimulation. We found that a cold stimulation at 4 degrees C showed a marked increase in the number of activated neurons. Furthermore, double staining for phosphorylated-extracellular signal-regulated protein kinase and phosphorylated-p38 showed no colocalization in the dorsal root ganglion neurons. We then performed double-labeling experiments for TRPA1 and TRPM8 mRNA and phosphorylation of mitogen-activated protein kinase. The majority of phosphorylated-extracellular signal-regulated protein kinase-positive neurons also expressed TRPM8 mRNA, whereas phosphorylated-p38 heavily colocalized with TRPA1 mRNA after noxious cold stimulation. Our data suggest that the noxious, but not innocuous, cold stimulation in vivo induced differential activation of extracellular signal-regulated protein kinase and p38 pathways in each subpopulation containing TRPA1 or TRPM8 in dorsal root ganglion.

The effect of site and type of nerve injury on the expression of brain-derived neurotrophic factor in the dorsal root ganglion and on neuropathic pain behavior

A number of rat neuropathy models have been developed to simulate human neuropathic pain conditions, such as spontaneous pain, hyperalgesia, and allodynia. In the present study, to determine the relative importance of injury site (proximal or distal to the primary afferent neurons) and injury type (motor or sensory), we examined pain-related behaviors and changes of brain-derived neurotrophic factor expression in the dorsal root ganglion in sham-operated rats, and in the L5 dorsal rhizotomy, L5 ventral rhizotomy, L5 dorsal rhizotomy+ventral rhizotomy, and L5 spinal nerve transection models. L5 ventral rhizotomy and spinal nerve transection produced not only mechanical and heat hypersensitivity, but also an increase in brain-derived neurotrophic factor mRNA/protein in the L5 dorsal root ganglion at 7 days after surgery. In contrast, rats in the L5 dorsal rhizotomy and dorsal rhizotomy+ventral rhizotomy groups did not show both pain behaviors at 7 days after surgery, despite brain-derived neurotrophic factor upregulation in medium- and large-size neurons in the L5 dorsal root ganglion. On the other hand, L5 spinal nerve transection, but not dorsal rhizotomy, dorsal rhizotomy+ventral rhizotomy or ventral rhizotomy, increased the expression of brain-derived neurotrophic factor in the L4 dorsal root ganglion at 7 days after surgery. Taken together, these findings suggest that the upregulation of brain-derived neurotrophic factor expression in the L4 and L5 dorsal root ganglion neurons may be, at least in part, involved in the pathophysiological mechanisms of neuropathic pain and that the selective nerve root injury models may be useful for studying the underlying mechanisms of chronic pain after nerve injury.

Visualization of spatiotemporal activation of Notch signaling: Live monitoring and significance in neural development

Notch signaling plays various key roles in cell fate determination during CNS development in a context-dependent fashion. However, its precise physiological role and the localization of its target cells remain unclear. To address this issue, we developed a new reporter system for assessing the RBP-J-mediated activation of Notch signaling target genes in living cells and tissues using a fluorescent protein Venus. Our reporter system revealed that Notch signaling is selectively activated in neurosphere-initiating multipotent neural stem cells in vitro and in radial glia in the embryonic forebrain in vivo. Furthermore, the activation of Notch signaling occurs during gliogenesis and is required in the early stage of astroglial development. Consistent with these findings, the persistent activation of Notch signaling inhibits the differentiation of GFAP-positive astrocytes. Thus, the development of our RBP-J-dependent live reporter system, which is activated upon Notch activation, together with a stage-dependent gain-of-function analysis allowed us to gain further insight into the complexity of Notch signaling in mammalian CNS development.

Induction of plasminogen activator inhibitor-1 and -2 in dorsal root ganglion neurons after peripheral nerve injury

We have previously found that tissue type and urokinase type plasminogen activators (tPA and uPA) are induced in dorsal root ganglia (DRG) neurons after peripheral axotomy and that tPA plays crucial roles in generating neuropathic pain. Here we examined whether the plasminogen activator inhibitor-1 and -2 (PAI-1 and PAI-2) mRNA, endogenous inhibitors of tPA and uPA, are induced in the DRG following sciatic nerve transection. L4 and L5 DRG sections were examined using in situ hybridization histochemistry. The results showed that both PAI-1 and PAI-2 mRNA were up-regulated in DRG neurons within 1 day, and peaked at 1-3 days, after injury. Reduction of these mRNA was observed from 7 days after injury. The precise expression patterns of PAI-1 and PAI-2 mRNA at 3 days after axotomy revealed that PAI-1 mRNA was observed in predominantly small neurons, while much of the PAI-2 mRNA was expressed in large neurons. Double-labeling analysis of these mRNAs with activated transcription factor 3, known as an injury marker, revealed that most PAI-1 and PAI-2 mRNAs was induced in injured neurons. Co-expression of PAI-1, 2 with tPA and uPA in DRG neurons suggests that these inhibitors may act in an autocrine manner to modulate extracellular proteolytic activity after nerve injury.

Activation of extracellular signal-regulated protein kinase in the dorsal root ganglion following inflammation near the nerve cell body

Inflammation of the primary afferent proximal to the dorsal root ganglion (DRG) and the DRG itself is known to produce radicular pain. Here, we examined pain-related behaviors and the activation of extracellular signal-regulated protein kinase (ERK) in the DRG after inflammation near the DRG somata. Inflammation of the L4/5 nerve roots and DRG induced by complete Freund's adjuvant (CFA) produced mechanical allodynia on the ipsilateral hindpaw and induced an increase in the phosphorylation of ERK, mainly in tyrosine kinase (trk) A-expressing small- and medium-size neurons. This CFA-induced increase in ERK phosphorylation was mediated through trk receptors, because intrathecal treatment with the tyrosine kinase inhibitor, K252a, reduced the activation of ERK. On the other hand, an increase in brain-derived neurotrophic factor (BDNF) mRNA/protein in the DRG concomitant with the ERK activation was also observed. Furthermore, we found that nerve growth factor (NGF) injection directly into the L4/5 nerve roots and DRG produced mechanical allodynia, and an increase in the phosphorylation of ERK and BDNF expression in the DRG, but the mitogen-activated protein kinase (MAPK) kinase1/2 inhibitor, U0126, inhibited the effects induced by NGF. Therefore, we suggest that after inflammation near the cell body, NGF synthesized within the nerve root and DRG induces BDNF expression through trkA receptors and intracellular ERK-MAPK. The activation of MAPK in the primary afferents may be involved in the pathophysiological mechanisms of inflammation-induced radiculopathy and MAPK pathways in the primary afferents may be potential targets for pharmacological intervention for neuropathic pain produced by inflammation near the DRG somata.

Distinct expression patterns of splicing isoforms of mNumb in the endocrine lineage of developing pancreas

The pancreas is composed of three tissues: endocrine, exocrine, and duct. The endocrine/exocrine lineages diverge from the ductal lineage before E12.5 in mice, and then further separate into endocrine and exocrine precursors. These processes are regulated by differential activation of Notch1-mediated signaling, which is required to repress the expression of the pro-endocrine gene neurogenin3 (ngn3) in the exocrine lineage. Mammalian Numb (mNumb) is an ortholog of Drosophila Numb (dNumb), which is likely to be an intracellular inhibitor of Notch signaling, and has four splicing isoforms: PTBS-PRRS, PTBL-PRRS, PTBS-PRRL, and PTBL-PRRL. Here we developed an anti-PRRL antibody, which recognizes only the PRRL forms of mNumb. We then performed immunohistochemical analyses using anti-PRRL together with anti-pan Numb, which recognizes all the isoforms of mNumb, antibodies that determine the spatio-temporal expression pattern of mNumb in the mouse fetal pancreas. mNumb PRRS and PRRL were first expressed in identical cells in the early stage of pancreatic development (i.e., E10.5), but gradually became biased. At the stage of endocrine and exocrine divergence, mNumb PRRS continued to be expressed in endocrine lineage cells, whereas PRRL was down-regulated during endocrine differentiation. Even after the endocrine/exocrine divergence, notch1 expression was sustained in endocrine lineage, where ngn3 was expressed. These results agree with the notion that mNumb PRRS has an inhibitory effect on Notch signaling, indicating its potential roles in the differentiation of pancreatic endocrine lineage. In addition, islet cells, which are produced from ductal tissue, were immunostained by the anti-panNb antibody. Our present results will contribute to the understanding of the mechanisms of islet development from ductal tissue.

Diagnostic value of culture, histology and PCR for Helicobacter pylori in the remnant stomach after surgery

BACKGROUND

Diagnosis of Helicobacter pylori infection in the remnant stomach has not been established.

AIMS

To investigate the diagnostic value of culture, histology, PCR and serum IgG against H. pylori (ELISA) with and without eradication therapy in the remnant stomach, compared with the unoperated stomach.

METHODS

Biopsy samples for bacterial culture and histological diagnosis of H. pylori were taken from the stoma and upper corpus of the remnant stomach and gastric juice was used for PCR assay.

RESULTS

Bacterial culture-based diagnosis in the remnant stomach, sensitivity and specificity of culture were 95.1%, 100%; histology 89%, 92.3%; PCR 66%, 89.7%; and ELISA 100%, 50%, respectively, in cases without H. pylori eradication therapy. In assessment of the results of therapy for the remnant stomach, sensitivity and specificity of culture were 100%, 100%; histology 80%, 96.8%; PCR 80%, 91.7%; and ELISA 100%, 0%, respectively.

CONCLUSION

Bacterial culture had the highest diagnostic value in the remnant stomach as well as unoperated stomach. Sensitivity by histology and PCR was lower in the remnant stomach than the unoperated stomach, but specificity values were equal. Serum ELISA assay was not suitable for the remnant stomach.

Mapping spatio-temporal activation of Notch signaling during neurogenesis and gliogenesis in the developing mouse brain

Notch1 plays various important roles including the maintenance of the stem cell state as well as the promotion of glial fates in mammalian CNS development. However, because of the very low amount of the activated form of Notch1 present in vivo, its precise activation pattern has remained unknown. In this study, we mapped the active state of this signaling pathway in situ in the developing mouse brain using a specific antibody that recognizes the processed form of the intracellular domain of Notch1 cleaved by presenilin/gamma-secretase activity. By using this antibody, active state of Notch1 came to be detectable with a higher sensitivity than using conventional antibody against Notch1. We found that activated Notch1 was mainly detected in the nuclei of a subpopulation of radial glial cells, the majority of proliferating precursor cells in the ventricular zone (VZ). However, Notch1 activation was not detected in neuronal precursor cells positive for neuronal basic helix-loop-helix proteins or in differentiating neurons in the embryonic forebrain. Interestingly, we found that Notch1 was transiently activated in the astrocytic lineage during perinatal CNS development. Taken together, the present method has enabled us to determine the timing, gradients, and boundaries of the activation of Notch signaling.

Association of the interleukin-1 beta genetic polymorphism and gastric cancer risk in Japanese

BACKGROUND

Helicobacter pylori infection is associated not only with gastroduodenal ulcers but with the development of gastric cancer. Interleukin-1 beta (IL-1 beta) is a potent inhibitor of gastric secretion. The -31 C-to-T base transition in the intron of this gene has been reported to be involved in carcinogenic changes within the stomach, especially in H. pylori-infected individuals.

METHODS

In this study, the -511 T-to-C polymorphism in the IL-1 beta gene was investigated in 669 patients with gastric diseases.

RESULTS

The allelic frequencies of the C allele, which indicates low acid secretion and is a component of a supposedly high-risk genotype for gastric cancer, were 0.48 in H. pylori-negative noncancer controls, 0.52 in H. pylori-positive noncancer controls, 0.57 in subjects with chronic active gastritis (CAG) with H. pylori, 0.58 in subjects with intestinal metaplasia (IM) or CAG without H. pylori, and 0.52 in gastric cancer patients. Significant differences among the groups were observed between the IM or CAG without H. pylori group and the gastric cancer group and between the IM or CAG without H. pylori group and the H. pylori-negative noncancer control group (P < 0.05).

CONCLUSIONS

The IL-1 beta-511 genetic polymorphism was not associated with gastric cancer in a multistep carcinogenesis model. However, in view of the results for the IM or CAG without H. pylori group, the presence of the C allele may also indicate a risk of mucosal atrophy of the stomach in the Japanese population.

Expression of amphiphysin I in Sertoli cells and its implication in spermatogenesis

Amphiphysin I is a protein concentrated in nerve terminals and involved in the endocytosis of synaptic vesicle membrane. We show here that amphiphysin I is expressed in the rat testis, localized exclusively in the Sertoli cells. In the postnatal testicular development, expression of amphiphysin I was not evident at birth, but became significant at postnatal day 15 (P15), coinciding with the onset of spermatogenesis. The expression level of amphiphysin I increased 10-fold between P15 and P25 to reach the adult level. In adult testes reversibly damaged by ethane dimethane sulphonate administration, expression of amphiphysin I did not change following the damage, whereas the protein was transiently converted into its phosphorylated form. The increase in levels of phosphorylated amphiphysin I was closely associated with the severe histological damage to germ cells. The present findings suggest that amphiphysin I in Sertoli cells is involved in spermatogenesis, probably through endocytic processes.

Hemorrhagic gastric carcinoma in an acromegalic patient

A rare case of hemorrhagic gastric carcinoma in an acromegalic patient is reported. A 79-year-old Japanese man was referred to our hospital with diagnoses of upper gastrointestinal hemorrhage and angina pectoris. This patient showed typical clinical features of acromegaly, with increased serum growth hormone (GH) and insulin-like growth factor I (IGF-I) level. A high titer of serum anti-Helicobacter pylori (H. pylori) IgG was also observed. After percutaneous transluminal coronary angioplasty treatment for stenosis of the right coronary artery, the patient underwent distal gastrectomy. Gastric cancer was Type 2 macroscopically and was diagnosed histologically as a papillary and well to moderately differentiated tubular adenocarcinoma. Reverse transcription-polymerase chain reaction analysis estimated that the amount of IGF-I receptor mRNA expression in the gastric cancer tissue was 1.6 times higher than that in the adjacent atrophic mucosa, whereas the amount of IGF-I mRNA expression in the cancer tissue was only half that in the atrophic mucosa. Both the stimulatory effects of GH and/or IGF-I on cell proliferation and H. pylori infection in gastric tumorigenesis may have been responsible for the development and growth of gastric carcinoma in this patient.

The effect of electroacupuncture on pain behaviors and noxious stimulus-evoked Fos expression in a rat model of neuropathic pain

Chronic-constriction injury (CCI) of the sciatic nerve causes mechanical and heat hyperalgesia and mechanical allodynia in the plantar surface of the hindpaw. The underlying mechanism thought to account for these phenomena include central sensitization induced by peripheral nerve injury, ie, the increase in neuronal activity of spinal dorsal horn neurons. As a marker of neuronal activation of the central nervous system, Fos expression has been used widely to monitor the change in neuronal activity evoked by peripheral input. In this study, we examined the antinociceptive effect of electroacupuncture (EA) on pain behavior and noxious stimulus-evoked Fos expression in dorsal horn neurons of the spinal cord in CCI rats 14 days after injury. Male Sprague-Dawley rats (180 to 200 g) received loose ligation of the left sciatic nerve. Heat and mechanical hyperalgesia and mechanical allodynia were examined by the plantar foot test, the pin-prick test, and the von Frey test before and after the EA treatment (100 Hz, 0.3 millisecond, 3 or 1 mA, 20 minutes) into the Zusanli point (S36). When EA stimulation to the Zusanli point was applied, the mechanical and heat hyperalgesia were significantly suppressed; however, mechanical allodynia was not affected. The EA stimulation to nonacupuncture point did not show any significant effect. Next, pinch stimulation was applied to the plantar surface of the operated hindpaw of the CCI rats for 10 minutes, and the stimulus-evoked Fos expression in dorsal horn neurons in L4-L6 spinal cord levels was then examined by using immunohistochemistry. The number of noxious stimulus-evoked Fos-labeled neurons in both the superficial and deep laminae of the dorsal horn in the CCI rats was increased significantly compared with those in sham-operated rats, suggesting an increased excitability of dorsal horn neurons to noxious stimuli. Concurrent EA treatment to the Zusanli point with the pinch stimulus suppressed the increase in the number of Fos-labeled cells in the spinal dorsal horn in the CCI rats. The present results show that EA treatment has antinociceptive effects on both pain behavior and neuronal activation of the spinal dorsal horn neurons in CCI rats.

The neural RNA-binding protein Musashi1 translationally regulates mammalian numb gene expression by interacting with its mRNA

Musashi1 (Msi1) is an RNA-binding protein that is highly expressed in neural progenitor cells, including neural stem cells. In this study, the RNA-binding sequences for Msi1 were determined by in vitro selection using a pool of degenerate 50-mer sequences. All of the selected RNA species contained repeats of (G/A)U(n)AGU (n = 1 to 3) sequences which were essential for Msi1 binding. These consensus elements were identified in some neural mRNAs. One of these, mammalian numb (m-numb), which encodes a membrane-associated antagonist of Notch signaling, is a likely target of Msi1. Msi1 protein binds in vitro-transcribed m-numb RNA in its 3'-untranslated region (UTR) and binds endogenous m-numb mRNA in vivo, as shown by affinity precipitation followed by reverse transcription-PCR. Furthermore, adenovirus-induced Msi1 expression resulted in the down-regulation of endogenous m-Numb protein expression. Reporter assays using a chimeric mRNA that combined luciferase and the 3'-UTR of m-numb demonstrated that Msi1 decreased the reporter activity without altering the reporter mRNA level. Thus, our results suggested that Msi1 could regulate the expression of its target gene at the translational level. Furthermore, we found that Notch signaling activity was increased by Msi1 expression in connection with the posttranscriptional down-regulation of the m-numb gene.

Effect of matrix metalloproteinase inhibition on colonic anastomotic healing in rats

Wound strength depends on the balance between collagen synthesis and degradation; however, the role of collagen breakdown in wound healing is still not well understood. We investigated the role of matrix metalloproteinases in wound healing by using BE16627B, a matrix metalloproteinase inhibitor. Identical surgical procedures consisting of a colonic anastomosis (single-layer, inverted) and implantation of an osmotic pump in the back were performed in male Sprague-Dawley rats weighing 270 to 290 grams. The animals were randomly assigned to receive either BE16627B (n = 10) dissolved in dimethylsulfoxide and diluted with ethylene glycol at a dosage of 2.4 mg/rat/day for 3 days or the vehicle solution alone (n = 11). The solutions were administered through the surgically implanted osmotic pumps. The animals were killed 4 days after surgery, and the colonic bursting pressure (mm Hg) and hydroxyproline concentration (microg/mg wet tissue, index of collagen) were measured. The administration of BE16627B enhanced colonic anastomotic healing, as measured by the increase in the colonic bursting pressure (160 +/- 12 vs. 125 +/- 7 mm Hg; P < 0.05) and the increase in the soluble fraction of collagen (0.27 +/- 0.01 vs. 0.21 +/- 0.01 microg/mg wet tissue; P < 0.01) in the anastomosis. Histologic examination of the tissue revealed that the use of BE16627B resulted in the preservation of the multilayered colonic structure and increased the network of collagen between both ends of the colon in the thickening submucosal layer. These findings demonstrate that the inhibition of matrix metalloproteinase activity influences colonic anastomotic healing, indicating a potential mechanism for enhancing anastomotic healing.

Toxic shock-like syndrome with flu-like prodrome: a possible role of 'enhancing tissue focus' for streptococcal toxic shock

We describe three patients with invasive group A streptococcal infection, admitted during the 3 months between November 1996 and February 1997. All patients were previously healthy Japanese women who developed a profound shock, with a rapidly fatal outcome, after experiencing flu-like symptoms. All cases conformed to the case definition of toxic shock-like syndrome (TSLS).Currently, the pathogenic mechanism of TSLS remains unclear. Known microbial virulence factors can not sufficiently explain the occurrence of TSLS, and it has been generally considered that host factors may be contributory. On pathological examination, each patient had one organ or tissue that was most severely involved: Case 1 a non-penetrating trauma; Case 2 a pregnant uterus; and Case 3 a pulmonary lesion reminiscent of lymphocytic interstitial pneumonia. On the basis of clinicopathological features of these cases, we propose that the coexistence of 'enhancing tissue focus' may be one of host factors for the progression of TSLS in patients infected with non-invasive GAS.

Immunohistochemical analyses of DNA topoisomerase II isoforms in developing rat cerebellum

In mammalian cells, two isoforms of DNA topoisomerase II (topo IIalpha and topo IIbeta) have been identified. Topo IIalpha is essential in mitotic cells, whereas the function of topo IIbeta remains unclear. In the present study, we investigated the developmental control of topo II isoforms in two different neuronal lineages, cerebellar Purkinje cells and granule cells, by immunohistochemical analysis with isoform-specific monoclonal antibodies. As expected, proliferating cells in the neuroepithelium and in the external germinal layer (EGL) were topo IIalpha immunopositive. The migrating as well as differentiating Purkinje cells and granule cells showed an enhanced topo IIbeta immunoreactivity. The postmitotic granule cells in the postnatal EGL showed an abrupt transition of expressed topo II isoforms from IIalpha to IIbeta. The transition was clearly coincident with the completion of final cell division and the initiation of terminal differentiation because no increase of the topo IIbeta immunoreactivity was observed in the spreading EGL cells that are still in the cell division cycle. The topo IIbeta signal was detected in both nucleoplasm and nucleolus of differentiating cells. However, the nucleoplasmic signal decreased significantly as the cells reached terminal differentiation. The residual topo IIbeta in nucleoli was shown to occupy an unique location with respect to other nucleolar proteins, nucleolin and DNA topoisomerase I. Our findings indicate that both Purkinje cells and granule cells express the topo II isoforms in a similar timing during the cerebellar development and also suggest that topo IIbeta localized in nucleoplasm is the functional entity involved in neuronal differentiation.

Involvement of DNA topoisomerase IIbeta in neuronal differentiation

Two isoforms of DNA topoisomerase II (topo II) have been identified in mammalian cells. While topo IIalpha is essential for chromosome segregation in mitotic cells, in vivo function of topo IIbeta remains to be clarified. Here we demonstrate that the nucleoplasmic topo IIbeta, highly expressed in differentiating cerebellar neurons, is the catalytically competent entity operating directly on chromatin DNA in vivo. When the cells reached terminal differentiation, this in vivo activity decreased to a negligible level with concomitant loss of the nucleoplasmic enzyme. Effects of topo II-specific inhibitors were analyzed in a primary culture of cerebellar granule neurons that can mimic the in vivo situation. Only the beta isoform was expressed in granule cells differentiating in vitro. ICRF-193, a catalytic topo II inhibitor, suppressed the transcriptional induction of amphiphysin I which is essential for mature neuronal activity. The effect decreased significantly as the cells differentiate. Expression profiling with a cDNA macroarray showed that 18% of detectable transcripts were up-regulated during the differentiation and one-third of them were susceptible to ICRF-193. The results suggest that topo IIbeta is involved in an early stage of granule cell differentiation by potentiating inducible neuronal genes to become transcribable probably through alterations in higher order chromatin structure.

[How the lifestyle of families who care for home parenteral nutrition patients changes]

The role of families who care for home parenteral nutrition (HPN) patients is extremely important. They face many problems not only in caring for patients but also in their own lifestyle. We investigated by questionnaire the changes in the family of terminal stage cancer patients receiving HPN. Replies submitted to the questionnaire were obtained from 20 out of 32 families who underwent HPN in the Osaka Prefectural General Hospital. Ten out of 20 people answered that they changed their lifestyle during HPN. The changes were decreased opportunity to communicate with other people and decreased time for to spend on a hobby or other activity. The care of the HPN patients affects the wife, daughter-in-law and children more than the husband of the patient, because the former have to manage housekeeping as well as patient care. This result suggests that the quality of life of the family of terminal stage cancer patients at home with HPN declined because they had to change their own lifestyle in order to spare time to care for the patients.

[Comparison of the families of terminal stage cancer patients who underwent HPN and the nurses who cared those patients in their thoughts on home care]

In the home care for terminal stage cancer patients, the quality of life of patients has been regarded as more important than the QOL of their family. Now, however, we think the QOL of the family of the patients is as important as that of the patients themselves. We investigated the opinion of the families and nurses by questionnaire in the HPN care for terminal stage cancer patients and compared them. The family answered positively about HPN, but they had a negative opinion in that they do not want to undergo HPN because they felt a heavy burden and responsibility in caring for patients, and they do not want to cause these feelings in others in their family. The nurses also answered positively about HPN, and they answered that they want to undergo HPN if they have terminal stage cancer. These results suggest that the family feels a greater burden and responsibility in caring for patients at home than the medical staff realize. The medical staff should support the family as well as terminal stage cancer patients and should not force our own opinions as medical staff.

Posttranslational modification of the glycosylation inhibiting factor (GIF) gene product generates bioactive GIF

Glycosylation inhibiting factor (GIF) and macrophage migration inhibitory factor (MIF) share an identical structure gene. Here we unravel two steps of posttranslational modifications in GIF/MIF molecules in human suppressor T (Ts) cell hybridomas. Peptide mapping and MS analysis of the affinity-purified GIF from the Ts cells revealed that one modification is cysteinylation at Cys-60, and the other is phosphorylation at Ser-91. Cysteinylated GIF, but not the wild-type GIF/MIF, possessed immunosuppressive effects on the in vitro IgE antibody response and had high affinity for GIF receptors on the T helper hybridoma cells. In vitro treatment of wild-type recombinant human GIF/MIF with cystine resulted in preferential cysteinylation of Cys-60 in the molecules. The cysteinylated recombinant human GIF and the Ts hybridoma-derived cysteinylated GIF were comparable both in the affinity for the receptors and in the immunosuppressive activity. Polyclonal antibodies specific for a stretch of the amino acid sequence in alpha2-helix of GIF bound bioactive cysteinylated GIF but failed to bind wild-type GIF/MIF. These results strongly suggest that cysteinylation of Cys-60 and consequent conformational changes in the GIF/MIF molecules are responsible for the generation of GIF bioactivity.

Effect of early postoperative feeding on the healing of colonic anastomoses in the presence of intra-abdominal sepsis in rats

PURPOSE

Intra-abdominal infection is generally considered a major risk factor for dehiscence of primary colon anastomosis. To elucidate the indications for nutritional support during intra-abdominal sepsis, we investigated the healing of anastomoses in an animal model.

METHODS

Twenty male Sprague-Dawley rats (280-320 g) underwent cecal ligation and single puncture. After 24 hours the perforated cecum was removed, and the left colon was transected and anastomosed in a single-layer inverted fashion. Animals were randomly assigned to receive both chow and water (early-fed group; n = 10) or water alone for the first 72 hours and chow thereafter (late-fed group; n = 10). Colon-bursting pressure was measured five days after the anastomosis, at which time the anastomosis was excised.

RESULTS

The survival rate after cecal ligation and single puncture was 100 percent, and blood cultures were positive in 20 percent of animals five days after surgery. All data are expressed as means +/- standard error of the mean. Body weight increased more in the early-fed group than in the late-fed group (15.6+/-3 vs. -6.3+/-2.8 g; P < 0.001). Early feeding resulted in increased anastomotic bursting pressure (200+/-11 vs. 161+/-12 mmHg; P < 0.05) and total collagen concentration at the site of anastomosis (2.36+/-0.09 vs. 2.01+/-0.07 microg/mg wet tissue; P < 0.01) compared with the late-fed group.

CONCLUSION

Early feeding has a positive effect on anastomotic healing in the presence of intraabdominal sepsis. The mechanism by which early feeding enhances the colonic anastomotic healing is unclear, although preservation of colonic collagen seems to play a significant role.

On the antioxidant mechanism of curcumin: classical methods are needed to determine antioxidant mechanism and activity

[reaction: see structure] The antioxidant activity of curcumin (1, 7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) was determined by inhibition of controlled initiation of styrene oxidation. Synthetic nonphenolic curcuminoids exhibited no antioxidant activity; therefore, curcumin is a classical phenolic chain-breaking antioxidant, donating H atoms from the phenolic groups not the CH(2) group as has been suggested (Jovanovic et al. J. Am. Chem. Soc. 1999, 121, 9677). The antioxidant activities of o-methoxyphenols are decreased in hydrogen bond accepting media.

Regional differences in the expression of DNA topoisomerase IIbeta in the pyramidal neurons of the rat hippocampus

A detailed analysis of the differential expression of a nuclear enzyme, DNA topoisomerase (topo) IIbeta, was performed in the rat hippocampal pyramidal layer. Three-dimensional (3-D) reconstruction from serial sections immunostained with anti-topo IIbeta antibody showed that the immunoreactivity was apparently weak in the entire CA3 region. Almost all CA1 pyramidal cells showed similar immunoreactivity to that seen in the dentate granular cells, the subicular neurons, and the cerebral neocortical neurons. In addition, immunoblotting analysis in the adult dorsal hippocampus showed that the expression level of topo IIbeta in the CA3 was significantly lower than that in the CA1 region. The dissociation in the expression level between CA1 and CA3 occurred in postnatal days 4 (P4) through P6. The present finding suggests that the enzyme is possibly involved in activities of the hippocampal pyramidal neurons.