A relation between osteoclastogenesis inhibition and membrane-type estrogen receptor GPR30

Disruption of the cooperative balance between osteoblasts and osteoclasts causes various bone disorders, some of which are because of abnormal osteoclast recruitment. Osteoporosis, one of the bone disorders, is not effectively treated by currently available medicines. In addition to the development of novel drugs for palliative treatment, the exploitation of novel compounds for preventive treatment is important in an aging society. Quercetin, a major flavonoid found in many fruits and vegetables, has been expected to inhibit cancer and prevent several diseases because of its anti-inflammatory and estrogenic functions. It has been reported that quercetin has the potential to reduce bone resorption, but the mechanism by which this compound affects the differentiation of osteoclasts remains unknown. Here, using a bone marrow cell-based in vitro osteoclast differentiation system from bone marrow cells, we found that the ability of quercetin to inhibit osteoclastogenesis was related to its estrogenic activity. The inhibition was partially blocked by a specific antagonist for the nuclear receptor estrogen receptor α, but a specific antagonist of the membrane-type receptor GPR30 completely ablated this inhibition. Furthermore, quercetin suppressed the transient increase of Akt phosphorylation induced by the stimulation of macrophage colony-stimulating factor and receptor activator of NF-κB ligand with no effect on MAPK phosphorylation, suggesting exquisite crosstalk between cytokine receptor and G-protein coupled receptor signaling. These results indicate the important role of GPR30 in osteoclast differentiation and provide new insights to the development of new treatments for osteoporosis.

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Flavonoids can prevent osteoporosis, but the precise mechanism remains unknown.

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The major flavonoid quercetin inhibited osteoclastogenesis.

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The inhibition was entirely rescued by GPR30 antagonism.

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GPR30 has a key role in mechanism of osteoclastogenesis prevention by quercetin.

The effect of repeated stress on KCC2 and NKCC1 immunoreactivity in the hippocampus of female mice

K⁺–Cl⁻ co-transporter (KCC2) and Na⁺–K⁺–2Cl⁻ co-transporter (NKCC1) are the main regulators of neuronal intracellular chloride concentration; altered expression patterns of KCC2 and NKCC1 have been reported in several neurodegenerative diseases. In this paper, we show the effect of repeated stress on KCC2, NKCC1, and serine 940 phosphorylated KCC2 (pKCC2^ser940) immunoreactivity.

The data were obtained from the hippocampus of female mice using single-plane confocal microscopy images. The mean fluorescence intensity of the perisomatic area of neurons, defined as raw fluorescence intensity (RFI) was calculated. Repeated stress (RS) resulted in a decrease in perisomatic area of immunoreactive (IR)-KCC2 and an increase of the IR-NKCC1. In addition, RS decreased perisomatic IR-pKCC2^ser940, corresponding to that of KCC2. The data in this article support the results of a previous study [1] and provide the details of immunohistological methods. Interpretation of the data in this article can be found in “Repeated stress-induced expression pattern alterations of the hippocampal chloride transporters KCC2 and NKCC1 associated with behavioral abnormalities in female mice” by Tsukahara et al. [1].

Repeated stress-induced expression pattern alterations of the hippocampal chloride transporters KCC2 and NKCC1 associated with behavioral abnormalities in female mice

The balance of cation-chloride co-transporters, particularly KCC2 and NKCC1, is critical for GABAergic inhibitory signaling. However, KCC2/NKCC1 balance is disrupted in many neurodegenerative diseases. Moreover, correlations between chronic stress, KCC2 and NKCC1 in the hippocampus remain poorly understood. Despite the fact that emotional disorders in humans are far more prevalent in women, there have been relatively few studies about female subjects. Here we investigated behaviors and expression patterns of KCC2 and NKCC1 in the hippocampi of female mice under chronic stress. Repeated stress (RS) was induced in experimental mice by repeated forced water administration. Then, expression patterns of GABAergic signaling molecules were identified by immunohistochemical analysis and performance was assessed using several behavioral tests. The results of semi-quantitative analysis showed that RS decreased KCC2 expression and increased NKCC1 expression in membranes of granular and pyramidal cells in the hippocampus. The novel object recognition (NOR) test and sociability test revealed that RS induced cognitive and sociability deficits, whereas RS increased the time spent in the open arms of the elevated plus maze test and induced attention deficits in other tests. In summary, RS induced alterations in membrane KCC2/NKCC1 balance in the hippocampus of female mice, which may contribute to GABAergic disinhibition associated with cognitional, sociability and attention deficits.

Low-intensity resistance training after high-intensity resistance training can prevent the increase of central arterial stiffness

Although high-intensity resistance training increases arterial stiffness, low-intensity resistance training reduces arterial stiffness. The present study investigates the effect of low-intensity resistance training before and after high-intensity resistance training on arterial stiffness. 30 young healthy subjects were randomly assigned to a group that performed low-intensity resistance training before high-intensity resistance training (BLRT, n=10), a group that performed low-intensity resistance training after high-intensity resistance training (ALRT, n=10) and a sedentary control group (n=10). The BLRT and ALRT groups performed resistance training at 80% and 50% of one repetition maximum twice each week for 10 wk. Arterial stiffness was measured using carotid-femoral and femoral-ankle pulse wave velocity (PWV). One-repetition maximum strength in the both ALRT and BLRT significantly increased after the intervention (P<0.05 to P<0.01). Both carotid-femoral PWV and femoral-ankle PWV after combined training in the ALRT group did not change from before training. In contrast, carotid-femoral PWV after combined training in the BLRT group increased from before training (P <0.05). Femoral-ankle PWV after combined training in the both BLRT and ALRT groups did not change from before training. These results suggest that although arterial stiffness is increased by low-intensity resistance training before high-intensity resistance training, performing low-intensity resistance training thereafter can prevent the increase of arterial stiffness.

Low-density lipoprotein receptor deficiency causes impaired osteoclastogenesis and increased bone mass in mice because of defect in osteoclastic cell-cell fusion

Osteoporosis is associated with both atherosclerosis and vascular calcification attributed to hyperlipidemia. However, the cellular and molecular mechanisms explaining the parallel progression of these diseases remain unclear. Here, we used low-density lipoprotein receptor knockout (LDLR(-/-)) mice to elucidate the role of LDLR in regulating the differentiation of osteoclasts, which are responsible for bone resorption. Culturing wild-type osteoclast precursors in medium containing LDL-depleted serum decreased receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation, and this defect was additively rescued by simultaneous treatment with native and oxidized LDLs. Osteoclast precursors constitutively expressed LDLR in a RANKL-independent manner. Osteoclast formation from LDLR(-/-) osteoclast precursors was delayed, and the multinucleated cells formed in culture were smaller and contained fewer nuclei than wild-type cells, implying impaired cell-cell fusion. Despite these findings, RANK signaling, including the activation of Erk and Akt, was normal in LDLR(-/-) preosteoclasts, and RANKL-induced expression of NFATc1 (a master regulator of osteoclastogenesis), cathepsin K, and tartrate-resistant acid phosphatase was equivalent in LDLR-null and wild-type cells. In contrast, the amounts of the osteoclast fusion-related proteins v-ATPase V(0) subunit d2 and dendritic cell-specific transmembrane protein in LDLR(-/-) plasma membranes were reduced when compared with the wild type, suggesting a correlation with impaired cell-cell fusion, which occurs on the plasma membrane. LDLR(-/-) mice consistently exhibited increased bone mass in vivo. This change was accompanied by decreases in bone resorption parameters, with no changes in bone formation parameters. These findings provide a novel mechanism for osteoclast differentiation and improve the understanding of the correlation between osteoclast formation and lipids.

Receptor activator of NF-κB ligand-dependent expression of caveolin-1 in osteoclast precursors, and high dependency of osteoclastogenesis on exogenous lipoprotein

Although extensive studies have done much to clarify the molecular mechanisms of osteoclastogenesis during the last ten years, there may still be unknown molecules associated with osteoclast differentiation. Thus, we used fluorescent differential display to screen for genes whose expression is induced by receptor activator of NF-κB ligand (RANKL), a crucial molecule for osteoclast formation. We identified caveolin-1 (Cav-1) as a RANKL-induced gene. Cav-1 is a major structural protein of caveolae and lipid rafts, cholesterol-enriched microdomains in the plasma membrane (PM). The RANKL-induced Cav-1 was immediately conveyed to lipid rafts. Conversely, expression of flotillin-1 (Flot-1), another scaffolding protein of lipid rafts, was reduced during osteoclastogenesis, indicating conversion of Flot-1-predominant rafts into Cav-1-enriched rafts. However, in vitro osteoclastogenesis of precursor cells from Cav-1-null mice was comparable to that of wild-type mice, while Cav-2 expression in the knockout osteoclasts was maintained. Conversely, Cav-2 gene silencing in Cav-1-null osteoclast precursors using siRNA for Cav-2 increased osteoclast formation, suggesting that the Cav-1/Cav-2 complex may act as a negative regulator for osteoclastogenesis. On the other hand, destruction of lipid rafts by removal of cholesterol from the PM by methyl-ß-cyclodextrin (MCD) treatment caused disordered signal transductions for osteoclastogenesis, such as hyperactivation of Erk1/2 and insensitivity of Akt to RANKL stimulus. The abnormal signaling was reproduced by deleting exogenous lipoproteins from the culture medium, which also resulted in reduced osteoclast formation. In addition, the deletion caused delayed expression of nuclear factor of activated T cells c1 (NFATc1), and depressed its activation in the cytosol and inhibited its translocation into nuclei. Simultaneously, the deletion reduced the level of FcRγ, a trigger protein for initiating the calcium signaling needed to activate NFATc1, and decreased Cav-1 in lipid rafts. These findings indicate that the molecular mechanisms of osteoclastogenesis are highly dependent on extracellular lipoprotein and the integrity of lipid rafts, and suggest possible involvement of cholesterol.

The expression patterns of Pax7 in satellite cells during overload-induced rat adult skeletal muscle hypertrophy

AIM

Activated satellite cells (SCs) have the ability to reacquire a quiescent, undifferentiated state. Pax7 plays a crucial role in allowing activated SCs to undergo self-renewal. Because the increase in the SC population is induced during overload-induced skeletal muscle hypertrophy, it is possible that Pax7-regulated SC self-renewal is involved in the modulation of the SC population during the functional overload of skeletal muscles. However, the characteristics of the expression patterns of Pax7 in SCs during the functional overload of adult skeletal muscles are poorly understood.

METHODS

Using immunohistochemical approaches, we examined the temporal and spatial expression patterns of Pax7 expressed in SCs during the functional overloading of rat skeletal muscles.

RESULTS

The time course of Pax7 expression in SCs was similar to that of the expression of the differentiation regulatory factor myogenin during the early stage of functional overload. However, the percentage of SCs that expressed Pax7 was markedly higher than that of the SCs that expressed myogenin. Coexpression of Pax7 and myogenin was not detected in SCs. In addition, the expression of cyclin-dependent kinase inhibitor p21, which regulates cell cycle arrest and differentiation, was not detected in Pax7-positive SCs.

CONCLUSION

These results suggest that Pax7-regulated self-renewal of SCs may be induced during the early stage of functional overload and may contribute to modulating the SC population in hypertrophied muscles. Furthermore, it was suggested that the numbers of SCs which underwent self-renewal may be higher than that of SCs which were provided as the additional myonuclei for hypertrophying myofibres.

Protective protein/cathepsin A down-regulates osteoclastogenesis by associating with and degrading NF-kappaB p50/p65

Disruption of the cooperative function balance between osteoblasts and osteoclasts causes various bone disorders, some of which are attributed to abnormal osteoclast recruitment. Osteoclast differentiation is dependent on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) as well as the macrophage colony-stimulating factor. The osteoclast formation induced by cytokines requires activation of NF-kappaB, AP-1 and nuclear factor of activated T cells c1. However, osteoclasts are not the only cell types that express these transcription factors, suggesting that some unknown molecules specific for osteoclasts may associate with the transcription factors. Here, we explored the possibility of molecules binding directly to NF-kappaB and cloned protective protein/cathepsin A (PPCA) by yeast two-hybrid screening using a cDNA library of osteoclast precursors. Forced expression of PPCA with p50/p65 in HEK293 cells decreased both the level of p50/p65 proteins and the transcriptional activity. Abundant PPCA was detected in the lysosomes of the transfected HEK293 cells, but a small amount of this enzyme was also present in the cytosolic fraction. In addition, over-expression of PPCA caused the disappearance of p50/p65 in both the lysosomal and cytosolic fractions. PPCA was expressed throughout osteoclastogenesis, and the expression was slightly up-regulated by RANKL signaling. Knockdown of PPCA in osteoclast precursors with PPCA siRNA stimulated binding of nuclear proteins to oligonucleotides containing an NF-kappaB binding motif and increased osteoclastogenesis. Our present results indicate a novel role for PPCA in osteoclastogenesis via down-regulation of NF-kappaB activity and suggest a new function for PPCA as an NF-kappaB-degrading enzyme in addition to its known multifunctional properties.

Effects of muscle contraction timing during resistance training on vascular function

Muscle contractions in normal resistance training are performed by eccentric (ECC, lowering phase) and concentric (CON, lifting phase) muscle contractions. However, the difference in effects of timing of muscle contraction during resistance training on arterial stiffness is unknown. This study investigated the effect of muscle contraction timing during resistance training on vascular function in healthy young adults. Thirty healthy men were randomly assigned to group of resistance training with quick lifting and slow lowering (ERT, n=10), group of resistance training with slow lifting and quick lowering (CRT, n=10) and sedentary groups (SED, n=10). The ERT and CRT groups underwent two supervised resistance-training sessions per week for 10 weeks. The ERT group performed the on set of 8-10 repetitions with 3 s ECC and 1 s CON muscle contractions. In contrast, the CRT group performed the on set of 8-10 repetitions with 1 s ECC and 3 s CON muscle contractions. Brachial-ankle pulse wave velocity (baPWV) after ERT did not change from baseline. In contrast, baPWV after CRT increased from baseline (from 1049+/-37 to 1153+/-30 cm s(-1), P<0.05). No significant changes in flow-mediated dilation were observed in the ERT and CRT groups. These values did not change in the SED group. These findings suggest that although both training does not deteriorate a vascular endothelial function, resistance training with quick lifting and slow lowering (that is, ERT) prevent the stiffening of arterial stiffness.

Production of IL-7 is increased in ovariectomized mice, but not RANKL mRNA expression by osteoblasts/stromal cells in bone, and IL-7 enhances generation of osteoclast precursors in vitro

Osteoclastogenic cytokines produced by T and B lineage cells and interleukin (IL)-7-induced expansion of the pool size of osteoclast precursors have been suggested to play an important role in acceleration of osteoclastogenesis induced by estrogen deficiency. However, the contribution of increased RANKL produced by osteoblasts/stromal cells to increase osteoclastogenesis in a mouse model of estrogen-deficient osteoporosis and in vitro effects of IL-7 on osteoclast precursor generation remain controversial. Thus, we investigated the effect of ovariectomy (OVX) of mice on production of RANKL, osteoprotegerin (OPG), and IL-7 in bone and the effect of IL-7 on osteoclast precursor generation in vitro. OVX did not significantly stimulate mRNA expressions of RANKL and OPG in whole femurs. Because the epiphysis, but not the femoral shaft (diaphysis) or bone marrow, is the main site of osteoclastogenesis, it is important to specifically analyze mRNA expression by osteoblasts/stromal cells at these parts of the femur. Therefore, we isolated RNA from bone marrow cell-free epiphysis, diaphysis, and flushed-out bone marrow and examined mRNA expression. The results showed no significant changes of RANKL and OPG mRNA expression in any part of the femur. In addition, OVX did not significantly affect RANKL and OPG mRNA expression by the adherent stromal cells isolated from flushed-out bone marrow cells but did stimulate RANKL mRNA expression by B220(+) cells in the nonadherent cell fraction. On the other hand, OVX increased IL-7 mRNA expression in the femur as well as IL-7 concentrations in bone fluid. In cultures of unfractionated bone cells isolated by vigorous agitation of minced whole long bones to release the cells tightly attached to the bone surfaces, but not in cocultures of clonal osteoblasts/stromal cells and flushed-out bone marrow cells, IL-7 stimulated generations of osteoclasts as well as osteoclast precursors. These data suggest that increased RANKL production by osteoblasts/stromal cells is unlikely to play a central role in acceleration of osteoclastogenesis in estrogen deficiency of mice and that IL-7 stimulates osteoclast precursor generation, presumably through an action of IL-7 on the cells attached to bone rather than on cells contained in the bone marrow cell population.

PGC7/Stella protects against DNA demethylation in early embryogenesis

DNA methylation is an important means of epigenetic gene regulation and must be carefully controlled as a prerequisite for normal early embryogenesis. Although global demethylation occurs soon after fertilization, it is not evenly distributed throughout the genome. Genomic imprinting and epigenetic asymmetry between parental genomes, that is, delayed demethylation of the maternal genome after fertilization, are clear examples of the functional importance of DNA methylation. Here, we show that PGC7/Stella, a maternal factor essential for early development, protects the DNA methylation state of several imprinted loci and epigenetic asymmetry. After determining that PGC7/Stella binds to Ran binding protein 5 (RanBP5; a nuclear transport shuttle protein), mutant versions of the two proteins were used to examine exactly when and where PGC7/Stella functions within the cell. It is likely that PGC7/Stella protects the maternal genome from demethylation only after localizing to the nucleus, where it maintains the methylation of several imprinted genes. These results demonstrate that PGC7/Stella is indispensable for the maintenance of methylation involved in epigenetic reprogramming after fertilization.

Effects of eccentric and concentric resistance training on arterial stiffness

It has been suggested that resistance training (RT) increases arterial stiffness. The purpose of the present study was to clarify the effect of eccentric RT (ERT) and concentric RT (CRT) on arterial stiffness in female adults by an interventional study. In total, 29 healthy female subjects were randomly assigned to either the ERT group (n=10), CRT group (n=10) or sedentary (SED) group (n=9). The ERT and CRT groups performed resistance training three times a week for 8 weeks. We determined brachial blood pressure, brachial-ankle pulse wave velocity (baPWV), carotid artery intimamedial thickness (IMT) and carotid arterial lumen diameter before and after training and after detraining. The before-training baPWV did not differ significantly among the three groups. After 8 weeks of RT, arterial stiffness in the CRT group was increased compared with the ERT and SED group (P<0.05). However, brachial blood pressure, baPWV, carotid IMT and carotid lumen diameter in the ERT and CRT groups were unchanged by RT for 8 weeks. Consequently, it was clarified that arterial stiffness was not changed by ERT for 8 weeks. This suggests that ERT may be effective as an exercise prescription for middle-aged and elderly adults.

Localization of MyoD, myogenin and cell cycle regulatory factors in hypertrophying rat skeletal muscles

AIM

MyoD, myogenin, proliferating cell nuclear antigen (PCNA) and cyclin-dependent kinase inhibitor p21 (p21) proteins are key molecules in inducing the growth of myogenic cells in vitro. However, it has not been determined which cell types express these factors in hypertrophying skeletal muscles in vivo.

METHODS

Using immunohistochemical techniques, we examined the spatial and temporal expression patterns of MyoD, myogenin, PCNA and p21 proteins in functionally overloaded rat plantaris muscles induced by ablation of the soleus and gastrocnemius muscles.

RESULTS

MyoD and myogenin were detected in myonuclei located inside the dystrophin-positive plasma membrane of myofibres, m-cadherin-positive satellite cell nuclei and nuclei located in the interstitial spaces between myofibres on days 1, 3, 5 and 7 post-surgery. Entry of satellite cells into the cell cycle was indicated by the expression of PCNA on day 3 post-surgery, and withdrawal from the cell cycle was observed by the expression of p21 in satellite cell nuclei on day 5 post-surgery. However, the expression of both PCNA and p21 in satellite cell nuclei disappeared on day 7 post-surgery.

CONCLUSION

These results indicate that proliferated satellite cell-derived myoblasts and undefined myogenic cells located in the interstitial spaces may contribute to an increase in myonuclear number and/or hyperplasia. Furthermore, we provide evidence that all of myonuclei, satellite cells and undefined myogenic cells express both MyoD and myogenin proteins. These results suggest that continual expression of MyoD and myogenin proteins in these cells is an essential molecular event which induces the successful hypertrophy of skeletal muscles.

Enhanced degradation of MDM2 by a nuclear envelope component, mouse germ cell-less

A mouse homologue of Drosophila germ cell less, mouse germ cell less-1 (mgcl-1), encodes a nuclear envelope component essential for nuclear integrity. To analyze the molecular function of mGCL-1, we carried out two hybrid screening and found that mGCL-1 bound to the gene product of tumor susceptibility gene 101 (tsg101). Effects of mGCL-1 on the expression of MDM2-p53 axis were examined, since TSG101 has been shown to elevate the amount of MDM2 by inhibiting the ubiquitination. mGCL-1 significantly reduced the amount of MDM2 probably by changing the sub-cellular localization of the MDM2 and facilitating the ubiquitination of MDM2. In addition, the amount of p53 was increased and transactivation by p53 was enhanced by mGCL-1. Thus, mGCL-1 turned out to be a factor modulating MDM2-p53 axis by enhanced degradation of MDM2.

GATA-2 and GATA-2/ER display opposing activities in the development and differentiation of blood progenitors

GATA-2 is a zinc finger transcription factor essential for the development of hematopoiesis. While GATA-2 is generally considered to play an important role in the biology of hematopoietic stem and progenitor cells, its function within these compartments is not well understood. Here we have employed both conditional expression of GATA-2 and conditional activation of a GATA-2/estrogen receptor (ER) chimera to examine the effect of enforced GATA-2 expression in the development and differentiation of hematopoietic progenitors from murine embryonic stem cells. Consistent with the phenotype of GATA-2 null animals, conditional expression of GATA-2 from a tetracycline-inducible promoter enhanced the production of hematopoietic progenitors. Conditional activation of a GATA-2/ER chimera produced essentially opposite effects to those observed with conditional GATA-2 expression. GATA-2 and GATA-2/ER differ in their binding activities and transcriptional interactions from other hematopoietic-associated transcription factors such as c-Myb and PU.1. While we have exploited these differences in activity to explore the transcriptional networks underlying hematopoietic cell fate determination, our results suggest that care should be taken in interpreting results obtained using only chimeric proteins.

Novel arterial infusion chemotherapy using cisplatin, 5-fluorouracil, and leucovorin for patients with advanced hepatocellular carcinoma

Advanced hepatocelluar carcinoma (HCC) has a poor prognosis. In this study, the authors evaluated the efficacy of chemotherapy using cisplatin (CDDP), 5-fluorouracil (5-FU), and leucovorin (LV), comparing our regimen with chemotherapy using CDDP and 5-FU. Nineteen patients with advanced HCC were treated by arterial infusion of a chemotherapeutic agent via a subcutaneously implanted injection port. In Group A (n=9), one course of chemotherapy consisted of the daily administration of CDDP (10 mg/1 h, on 5 days) and LV (12 mg/10 min, on 5 days) followed by 5-FU (250 mg/5 h, on 5 days). In Group B (n=10), except for the administration of LV, the same regimen was employed. This course was repeated each week for 4 weeks. In Group A, two patients showed a complete response (CR), and the other three showed a partial response (PR). In Group B, two patients showed PR. The response rate (CR+PR/all cases) in Group A was significantly higher than that in Group B (56 vs. 20%; P=0.022). The 1- and 2-year survival rates of Group A (66.7, 44.4%) were significantly higher than those of Group B (10, 0%) (P=0.033). These results suggest that our regimen may be useful in treating patients with advanced HCC.

Identification of PGC7, a new gene expressed specifically in preimplantation embryos and germ cells

The gene expression patterns of primordial germ cells (PGCs) and embryonic stem cells were analyzed by a modified serial analysis of gene expression. During the process, we cloned a novel gene, PGC7, which was preferentially expressed in PGCs. Immunohistochemical analysis revealed that PGC7 was specifically expressed in early pre-implantation embryos, PGCs and oocytes. These results suggest that PGC7 might play an important role in the development of PGCs and oocytes.

HBV-related fulminant hepatic failure: successful intensive medical therapy in a candidate for liver transplantation

Fulminant hepatic failure (FHF) usually has a fatal prognosis without liver transplantation. We describe the case of a woman who developed FHF, and was evaluated as a candidate for liver transplantation, but who was cured without transplantation through intensive medical care that included glucagon-insulin therapy, methylprednisolone pulse therapy, interferon beta and lamivudine administration, cyclosporine administration, and high-volume hemodiafiltration and plasma exchange. In a patient with FHF who is a candidate for liver transplantation but for whom the transplantation cannot be performed for some reason, intensive medical therapy, including regeneration-promoting therapy, immunosuppressive therapy, antiviral therapy, and vigorous hepatic support, should be carried out.

Augmenter of liver regeneration (ALR) may promote liver regeneration by reducing natural killer (NK) cell activity in human liver diseases

Cytotoxicity of liver natural killer cells against regenerating hepatocytes has been reported as a possible mechanism of regeneration failure in fulminant hepatitis. An augmenter of liver regeneration (ALR) inhibits liver natural killer cell activity in rats. In this study, we measured hepatic expression of ALR mRNA, blood levels of ALR, and peripheral blood natural killer cell activity in patients with various types of acute liver disease to investigate the relationship between failure of liver regeneration and hepatic natural killer cells. Hepatic ALR mRNA expression was higher in liver disease patients than in non-liver disease controls, and a correlation was found between serum ALR values and hepatic levels of ALR mRNA. In acute liver injury, the serum ALR level also showed a negative correlation with NK activity. ALR was produced by and released from the liver at the time of hepatic injury. Our findings suggest that ALR may protect against failure of regeneration by inhibition of hepatic natural killer cell activity in acute liver injury.

Molecular cloning of murine STAP-1, the stem-cell-specific adaptor protein containing PH and SH2 domains

To identify the novel substrate of c-kit which is important for hematopoietic stem cell self-renewal or differentiation, CD34-low/negative, Sca-1-positive, c-kit-positive, and lineage marker-negative (CD34(low/-)Sca-1(+)c-kit(+)Lin(-)) cells were sorted by a fluorescence-activated cell sorter from mouse bone marrow cells and a yeast two-hybrid cDNA library was constructed. By screening with c-kit as bait, we cloned a novel cDNA, designed STAP-1, encoding an adaptor protein with a Pleckstrin homology domain, the Src homology 2 (SH2) domain, and a number of tyrosine phosphorylation sites. RT-PCR analysis revealed that STAP-1 expression is restricted in the bone marrow cell fraction expressing c-kit. The highest expression was observed in the CD34(low/-)Sca-1(+)c-kit(+)Lin(-) stem cell-enriched fraction. The murine myeloid cell line, M1, expressed a high level of STAP-1. However, the expression was strongly repressed in response to leukemia inhibitory factor (LIF) which induced monocytic differentiation of M1 cells, suggesting that STAP-1 is associated with the undifferentiated cell type. A two-hybrid assay indicated that STAP-1 bound not only to c-kit but also to c-fms but not to JAK2 or Pyk2. In 293 cells, STAP-1 was tyrosine-phosphorylated by activated c-kit. An in vitro binding assay suggested that the STAP-1 SH2 domain interacted with several tyrosine-phosphorylated proteins including c-kit and STAT5. These suggest that STAP-1 functions as an adaptor molecule downstream of c-kit in hematopoietic stem cells.

The JAK-binding protein JAB inhibits Janus tyrosine kinase activity through binding in the activation loop

The Janus family of protein tyrosine kinases (JAKs) regulate cellular processes involved in cell growth, differentiation and transformation through their association with cytokine receptors. However, compared with other kinases, little is known about cellular regulators of the JAKs. We have recently identified a JAK-binding protein (JAB) that inhibits JAK signaling in cells. In the studies presented here we demonstrate that JAB specifically binds to the tyrosine residue (Y1007) in the activation loop of JAK2, whose phosphorylation is required for activation of kinase activity. Binding to the phosphorylated activation loop requires the JAB SH2 domain and an additional N-terminal 12 amino acids (extended SH2 subdomain) containing two residues (Ile68 and Leu75) that are conserved in JAB-related proteins. An additional N-terminal 12-amino-acid region (kinase inhibitory region) of JAB also contributes to high-affinity binding to the JAK2 tyrosine kinase domain and is required for inhibition of JAK2 signaling and kinase activity. Our studies define a novel type of regulation of tyrosine kinases and might provide a basis for the design of specific tyrosine kinase inhibitors.

CIS3 and JAB have different regulatory roles in interleukin-6 mediated differentiation and STAT3 activation in M1 leukemia cells

We have reported JAK-signaling modulators, CIS1 (cytokine-inducible SH2 protein-1), CIS3 and JAB (JAK2 binding protein), which are structurally related. In M1 myeloid leukemia cells, CIS3 was induced by neither interleukin 6 (IL6) nor interferon gamma (IFNgamma), while JAB was induced strongly by IFNgamma and slightly by IL6 and leukemia inhibitory factor (ILF). Forced expression of CIS3 and JAB in M1 cells prevented IL6- or LIF-induced growth arrest and differentiation, even when their expression levels were comparable to endogenous ones in several cell lines such as HEL, UT-7, IFNgamma-treated M1, and CTLL2 cells. Pretreatment of parental M1 cells with IFNgamma but not IFNbeta resulted in suppression of LIF-induced STAT3 activation and differentiation, further supporting that physiological level of JAB is sufficient to inhibit LIF-signaling. However, unlike JAB, CIS3 did not inhibit IFNgamma-induced growth arrest, suggesting a difference in cytokine specificity between CIS3 and JAB. CIS3 inhibited STAT3 activation with slower kinetics than JAB and allowed rapid c-fos induction and partial FcgammaRI expression in response to IL6. In 293 cells, CIS3 as well as JAB bound to JAK2 tyrosine kinase domain (JH1), and inhibited its kinase activity, however, the effect of CIS3 on tyrosine kinase activity was weaker than that of JAB, indicating that CIS3 possesses lower affinity to JAK kinases than JAB. These findings suggest that CIS3 is a weaker inhibitor than JAB against JAK signaling, and JAB and CIS3 possess different regulatory roles in cytokine signaling.

A Janus kinase inhibitor, JAB, is an interferon-gamma-inducible gene and confers resistance to interferons

It has been shown that interferons (IFNs) exert their signals through receptor-associated Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). However, molecular mechanism of regulation of IFN signaling has not been fully understood. We have reported novel cytokine-inducible SH2 protein (CIS) and JAK binding protein (JAB) family genes that can potentially modulate cytokine signaling. Here we report that JAB is strongly induced by IFN-gamma but not by IFN-beta in mouse myeloid leukemia M1 cells and NIH-3T3 fibroblasts. NIH-3T3 cells ectopically expressing JAB but not CIS3 lost responsiveness to the antiviral effect of IFN-beta and IFN-gamma. M1 leukemic cells stably expressing JAB were also resistant to IFN-gamma and IFN-beta-induced growth arrest. In both NIH-3T3 and M1 transformants expressing JAB, IFN-gamma did not induce tyrosine phosphorylation and DNA binding activity of STAT1. Moreover, IFN-gamma-induced activation of JAK1 and JAK2 and IFN-beta-induced JAK1 and Tyk2 activation were inhibited in NIH-3T3 JAB transformants. These results suggest that JAB inhibits IFN signaling by blocking JAK activity. We also found that IFN-resistant clones derived from LoVo cells and Daudi cells expressed high levels of JAB without stimulation. In IFN-resistant Daudi cells, IFN-induced STAT1 and JAK phosphorylation was partially reduced. Therefore, overexpression of JAB could be, at least in part, a mechanism of IFN resistance.

Fulminant hepatitis complicated by small intestine infection and massive hemorrhage

A 34-year-old man diagnosed with fulminant hepatitis, caused by hepatitis B virus, and acute renal failure was referred to our hospital. After admission to the intensive care unit, the liver and renal failure were ameliorated. Melena requiring transfusion occurred during the course of his illness. Endoscopic examination demonstrated pseudomembranes, erosions, ulcers, and hemorrhage in the duodenum, the upper jejunum, and the terminal ileum, suggesting widespread lesions throughout the small intestine. Pseudomonas putida, Xanthomonas maltophilia, and Candida glabrata were cultured from ileal fluid. Candida glabrata was also detected in sputum, feces, and on an intravenous catheter tip. The patient was treated with amphotericin B and miconazole. The melena was ameliorated, but inflammation of the small intestine persisted. Although we had difficulty in treating the enteritis, the patient survived, and 1 year later colonoscopic examination demonstrated no abnormalities. The small intestine is a difficult site to examine, but endoscopic examination of this site is important when massive hemorrhage develops.

Change in bacterial community during biodegradation of aniline

The response of river water microbial communities to chemical compounds was monitored under laboratory conditions using aniline as a model. Bacteria were collected from unpolluted and polluted sites. Bacterial abundance (plate and total direct counting) and its relation to aniline biodegradation was examined. Colony hybridization with 16S rRNA oligonucleotide probes was used to study the changes in microbial community structure during biodegradation of aniline. The changes in bacterial abundance and community structure were related to biodegradation of aniline. Burkholderia-Pseudomonas (rRNA group III), an authentic Alcaligenes group became dominant despite the initial differences in the microbial communities, suggesting that these genera are the main aniline degraders in the aquatic environment.

Purification and partial amino acid sequences of the binding protein from Bombyx mori for CryIAa delta-endotoxin of Bacillus thuringiensis

The binding protein for Bacillus thuringiensis delta-endotoxin, CryIAa, from the brush border membrane of the midgut of Bombyx mori was purified by the dot blot method and delta-endotoxin affinity chromatography. The binding protein was purified to 235-fold enrichment from cholic acid extracts of brush border membranes from B. mori midgut by activated CryIAa-affinity chromatography and DEAE ion-exchange chromatography. The purified binding protein showed a single band of 180 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and this band specifically reacted to 125I-labeled CryIAa on Immobilon membrane. The affinity of the binding protein for CryIAa was equivalent to that of the brush border membrane vesicles and solubilized membrane proteins. Partial amino acid sequences of the binding protein showed sequence similarity to the cadherin-like binding protein for CryIAb from Manduca sexta, but not for CryIAc binding protein from M. sexta and Heliothis virescens.

Cloning and characterization of novel CIS family genes

We have reported two JAK-signaling modulators, CIS (cytokine-inducible SH2 protein) and JAB (JAK2 binding protein), which are structurally related. Here we cloned three additional CIS family genes (CIS2, CIS3, and CIS4) on the basis of an expression sequence tag (EST) database search. We also found at least two additional candidates of this gene family in the database. These genes were induced by erythropoietin and granulocyte-macrophage colony stimulating factor in certain hematopoietic cell lines. The SH2 domain and a C-terminal 40 amino acid region, designated the CIS homology domain (CH domain), are highly conserved in this family, while the N-terminal regions of these proteins share little similarity. A yeast two-hybrid assay and in vitro and in vivo binding assays revealed that in addition to JAB, CIS3 bound to the JAK2 tyrosine kinase domain (JH1), although the interaction of CIS3 with the JAK2-JH1 domain was much weaker than that of JAB. Transient expression of JAB and CIS3, but not other CISs, strongly inhibited leukemia inhibitory factor (LIF)-induced STAT3-reporter gene activation in 293 cells. Furthermore, constitutive overexpression of JAB and CIS3 in M1 leukemia cells prevented LIF-induced differentiation and growth arrest. Although the physiological function remains to be investigated, CIS family genes could play a role in the negative regulation of cytokine signaling by interacting with specific targets.

Cloning and characterization of APS, an adaptor molecule containing PH and SH2 domains that is tyrosine phosphorylated upon B-cell receptor stimulation

Stimulation of B lymphocytes through their antigen receptor (BCR) results in rapid increases in tyrosine phosphorylation of a number of proteins, which leads to a cascade of biochemical changes that initiates B cell proliferation and differentiation or growth inhibition. A novel cDNA, designed APS, encoding an adaptor protein with a Pleckstrin homology (PH) domain, Src homology 2 (SH2) domain, and a tyrosine phosphorylation site was cloned from a B cell cDNA library using a yeast two hybrid system. APS is structurally similar to SH2-B, an SH2 protein that potentially binds to the immunoreceptor tyrosine-based activation motif (ITAM) as well as Lnk which is postulated to be a signal transducer that links T-cell receptor to phospholipase Cgamma, Grb2 and phosphatidylinositol 3-kinase. APS expressed only in human Burkitt's lymphoma cells among cell lines we examined and tyrosine phosphorylated in response to BCR stimulation. APS bound to Shc irrespective of stimulation and bound to Grb2 after stimulation, suggesting that it plays a role in linkage from BCR to Shc/Grb2 pathway. These results indicate that APS, SH2-B and Lnk form a new adaptor family that links immune receptors to signaling pathways involved in tyrosine-phosphorylation.

A new protein containing an SH2 domain that inhibits JAK kinases

The proliferation and differentiation of cells of many lineages are regulated by secreted proteins known as cytokines. Cytokines exert their biological effect through binding to cell-surface receptors that are associated with one or more members of the JAK family of cytoplasmic tyrosine kinases. Cytokine-induced receptor dimerization leads to the activation of JAKs, rapid tyrosine-phosphorylation of the cytoplasmic domains, and subsequent recruitment of various signalling proteins, including members of the STAT family of transcription factors, to the receptor complex. Using the yeast two-hybrid system, we have now isolated a new SH2-domain-containing protein, JAB, which is a JAK-binding protein that interacts with the Jak2 tyrosine-kinase JH1 domain. JAB is structurally related to CIS, a cytokine-inducible SH2 protein. Interaction of JAB with Jak1, Jak2 or Jak3 markedly reduces their tyrosine-kinase activity and suppresses the tyrosine-phosphorylation and activation of STATs. JAB and CIS appear to function as negative regulators in the JAK signalling pathway.

CIS, a cytokine inducible SH2 protein, is a target of the JAK-STAT5 pathway and modulates STAT5 activation

We searched for immediate early cytokine responsive genes and isolated a novel gene, CIS (Cytokine Inducible SH2 containing protein) that is induced in hematopoietic cells by a subset of cytokines including interleukin-2 (IL-2), IL-3, and erythropoietin (EPO). The mutant IL-2 receptor that fails to activate STAT5 could not induce CIS, suggesting that STAT5 is involved in the cytokine-inducible expression of CIS. We cloned the 5'-flanking region of the CIS gene and found that about 200 bases upstream of the transcription-initiation site contain four potential STAT5 binding sites (MGF boxes). Luciferase reporter assays showed that these MGF boxes were essential for EPO-dependent promoter activity. Expression of STAT5 and the EPO receptor in HEK293 cells conferred EPO-dependent activation of the CIS promoter. These data indicate that CIS is a target of the JAK-STAT5 pathway of cytokine receptors. CIS contains an SH2 domain and binds to tyrosine-phosphorylated EPO and IL-3 receptors. In HEK293 cells expressing STAT5 and the EPO receptor, EPO-dependent tyrosine phosphorylation of STAT5, as well as EPO-dependent CIS-promoter activation, was suppressed when CIS was coexpressed. Moreover, the induction of oncostatin M, another STAT5 target, as well as the tyrosine-phosphorylation of STAT5, were partially suppressed by CIS expression in Ba/F3 cells. Thus, CIS is a feedback modulator of STAT5; its expression is induced by STAT5 and it negatively modulates STAT5 activation.

Expression of hepatocyte growth factor, transforming growth factor alpha, and transforming growth factor beta 1 messenger RNA in various human liver diseases and correlation with hepatocyte proliferation

Hepatocyte growth factor (HGF) and transforming growth factor alpha (TGF-alpha) stimulate liver regeneration, whereas transforming growth factor beta 1 (TGF-beta 1) inhibits it in rats. However their significance in human liver diseases, especially in severe acute liver injury, remains unclear. We studied HGF, TGF-alpha, and TGF-beta 1 messenger RNA (mRNA) expression in the livers of patients with live diseases using a competitive reverse transcriptase polymerase chain reaction. As little as a twofold difference in mRNA expression could be detected from minute liver biopsy samples. We then examined cell proliferation using proliferating cell nuclear antigen (PCNA) staining. HGF mRNA levels were significantly higher (approximately threefold) in acute hepatitis (AH) than in exacerbation of chronic liver disease (EX) (P < .05). TGF-alpha mRNA levels were significantly greater in AH (approximately twofold) than EX (P < .05), and the levels were significantly higher (approximately threefold) in chronic hepatitis (CH) than in EX (P < .05). The TGF-beta 1 mRNA levels in all the groups were not significantly different. In acute liver injury (AH and EX), there was a significant correlation between HGF mRNA expression and the PCNA labeling index (LI) in the liver (r = .87, P < .005). TGF-alpha mRNA expression also correlated with the PCNA LI (r = .92,P < .0001). There was no significant correlation between the serum HGF and the PCNA LI in the liver. In conclusion, HGF and TGF-alpha produced in the liver stimulate hepatocyte proliferation in response to acute liver injury in humans.

Hepatocyte proliferation induced in rats by lead nitrate is suppressed by several tumor necrosis factor alpha inhibitors

Lead nitrate induces liver cell proliferation in rats without accompanying liver cell necrosis. However, the mechanism of this proliferation and its effect on hepatocytes remain unknown. Therefore, we examined the liver and blood level of hepatocyte growth factor and tumor necrosis factor alpha (TNF-alpha) at various intervals to determine whether lead nitrate modifies hepatocyte proliferation by altering the production of these cytokines. We also administered several TNF-alpha inhibitors, dexamethasone, adenosine, (2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonyl-2- propenoic acid (E 3330), and pentoxifylline, to rats to clarify whether pretreatment with these inhibitors suppresses the increase of TNF-alpha messenger RNA (mRNA) in the liver and prevents the hepatocyte proliferation induced by lead nitrate. Hepatocyte proliferation occurred by 24 hours and reached a peak 48 hours after a single intravenous injection of lead nitrate (100 mumol/kg). TNF-alpha mRNA expression in the liver was increased 1, 6, and 12 hours after the injection, whereas no alteration was observed in liver or blood level of hepatocyte growth factor. Pretreatment with dexamethasone (4.0 mg/kg), E3330 (100 mg/kg) adenosine (0.3 mmol/kg), and pentoxifylline (100 mg/kg), inhibited both TNF-alpha mRNA expression and hepatocyte proliferation 48 hours after the injection. These experimental results strongly support the hypothesis that TNF-alpha positively regulates the hepatocyte proliferation induced in rats by the mitogen, lead nitrate.

Expression of hepatocyte growth factor and transforming growth factor beta 1 mRNA in P. acnes and lipopolysaccharide-treated rats

Hepatocyte growth factor (HGF), a potent hepatocyte mitogen in vitro, triggers hepatocyte regeneration after partial hepatectomy and acute liver cell necrosis induced by chemicals. In contrast, transforming growth factor beta 1 inhibits hepatocyte proliferation in vitro and suppresses liver regeneration in vivo. We assessed the expression of HGF and TGF beta 1 mRNA in an endotoxin-related hepatic cell necrosis model. Intravenous injection of Gram-negative lipopolysaccharide (LPS) into rats previously given heat-killed Propionibacterium acnes induced endotoxin-related hepatic cell necrosis. In this model, serum ALT began to rise to more than 100IU as early as 3 h after LPS injection, reaching 300IU 12h after injection. HGF mRNA levels in the liver did not increase significantly until 5h after LPS injection; at 12h, they had increased about threefold compared with controls. TGF beta 1 mRNA expression increased threefold after P. acnes treatment alone and increased further after LPS injection. In the spleen, HGF mRNA levels increased within 3h, but in the lung no increase in HGF mRNA was observed. Early elevation of liver TGF beta 1 mRNA levels and delayed elevation of HGF mRNA levels, with low expression of HGF in the lung, may play a role in the pathogenesis of endotoxin-related hepatic necrosis.

Cyclosporine stimulates hepatocyte proliferation and accelerates development of hepatocellular carcinomas in rats

A recent study from our laboratory demonstrated that cyclosporine (CsA), a prototype immunosuppressant, enhanced the growth of carcinogen-induced enzyme altered foci in rat liver, suggesting that CsA may stimulate development of hepatocellular carcinomas. In the present study, we examined (i) whether CsA accelerates development of hepatocellular carcinomas in experimental animals, (ii) whether CsA stimulates the proliferation of resting hepatocyte in vivo and (iii) whether CsA modulates the production of growth factors implicated in liver cell growth, hepatocyte growth factor (HGF), transforming growth factor alpha (TGF alpha) and transforming growth factor beta 1 (TGF beta 1). Foci of hepatocytes, positive for glutathione S-transferase placental form were induced in male F344 rats by a single dose of diethylnitrosamine followed by 7 weeks promotion by a choline-deficient diet. The animals were then divided in two groups, and subsequent development of hepatocellular carcinomas was compared in rats fed a basal diet or a basal diet containing 0.015% CsA. Development of hepatocellular carcinoma was accelerated in the rats maintained on a CsA diet. Feeding a CsA diet as the sole treatment, for 2, 4 and 10 weeks induced significant increases in liver weight, and resulted also in an enhanced incorporation by hepatocytes of 5-bromo-2-deoxy-uridine. Serum levels of glutamate-oxaloacetate transferase, glutamate-pyruvate transferase and lactic dehydrogenase were not altered by feeding a CsA diet. Northern Blot analyses of the expression of HGF, TGF alpha and TGF beta 1 mRNAs in the liver showed similar patterns of expression between rats fed a basal diet and a CsA diet. The levels of HGF mRNA were not altered in the lungs and kidneys of rats fed a CsA diet. These results indicate that CsA stimulates rat liver cell proliferation in vivo without inducing liver cell necrosis, and that this effect may contribute to accelerated development of hepatocellular carcinomas in rats fed a CsA diet. As previously observed with BR 931, a hypolipidemic peroxisome proliferator, stimulation of liver cell growth by CsA did not entail changes in the production of HGF, TGF alpha or TGF beta 1.

Changes of vinculin and extracellular matrix components following blunt trauma to rat skeletal muscle

The purpose of the present study was to determine changes in the localization of vinculin, Type IV collagen, laminin, and fibronectin during the damage-repair process in the skeletal muscle over several days following acute blunt trauma. A single blunt trauma to the gastrocnemius muscle of the rat was induced by applying 1.57 J of kinetic energy to one leg. By day 2 after trauma, vinculin had disappeared rapidly from the intracellular submembraneous region corresponding to the costamere, whereas Type IV collagen and laminin persisted around the degenerating myofibers (corresponding to the basement membrane). Fibronectin could be observed filling the widened endomysium and in the ruptured myofibers. In the early phase of muscle regeneration (day 5 after trauma), newly synthesized vinculin, Type IV collagen, and laminin formed ring-like structures around the regenerating myotubes. Fibronectin could also be observed filling the widened endomysium around the regenerating myotubes. Further, when small newly formed or splitted myofibers were observed in the areas of regenerating myofibers (day 10 after trauma), vinculin, Type IV collagen, laminin, and fibronectin were localized in specialized regions corresponding to the costamere, basement membrane, and endomysium. These results demonstrated that restoration of the costamere, basement membrane, and endomysium are essential to the maturation of regenerating myofibers after injury.

Differential expression of hepatocyte growth factor, transforming growth factor-alpha and transforming growth factor-beta 1 messenger RNAs in two experimental models of liver cell proliferation

Hepatocyte growth factor, a potent hepatocyte mitogen in vitro, appears to trigger hepatocyte regeneration after partial hepatectomy and after acute liver cell necrosis. Transforming growth factor-alpha and transforming growth factor-beta 1 may also be involved in the control of liver regeneration. In this study we assessed possible roles of hepatocyte growth factor, transforming growth factor-alpha and transforming growth factor-beta 1 on liver cell proliferation in vivo, using a model of choline deficiency that is associated with liver cell necrosis and a model of a hypolipidemic agent (4-chloro-6-(2,3 xylidino)-2-pyrimidinylthio (N-beta-hydroxyethyl) acetamide) without liver necrosis. Male F344 rats were fed a choline-deficient diet or 0.16% 4-chloro-6-(2,3 xylidino)-2-pyrimidinylthio (N-beta-hydroxyethyl) acetamide diet for 6 and 4 wk, respectively. Rats were killed periodically, and the expression of hepatocyte growth factor messenger RNA in the liver, lung and kidney was determined by Northern-blot analysis. The levels of transforming growth factor-alpha and transforming growth factor-beta 1 messenger RNAs in the liver were also determined. Feeding a choline-deficient diet for 1 to 6 wk led to gradual increases in the levels of hepatocyte growth factor, transforming growth factor-alpha and transforming growth factor-beta 1 messenger RNAs in the liver. Feeding a 4-chloro-6-(2,3 xylidino)-2-pyrimidinylthio (N-beta-hydroxyethyl) acetamide diet for 3 days and 2 wk induced marked enhancement of liver cell proliferation as judged by hepatocyte 5-bromo-2-deoxyuridine incorporation.(ABSTRACT TRUNCATED AT 250 WORDS)

Theoretical studies on capillary microviscometry of skeletal muscle actin

For improving Ostwald's viscometry, which is time-consuming and requires a relatively large volume of specimen to determine viscosity, we developed a capillary microviscometric method with an appropriate mathematical model, and have compared this method with Ostwald's method.

HMM-decorated filaments in leukocyte nucleus

HMM-decorated filaments could be observed in the leukocyte nucleus under an electron microscope. The filaments were distributed in parallel or randomly among chromatin granules and showed "arrowhead" structures similar to those of cytoplasmic filaments. These observations suggest that the leukocyte nucleus may possess contractile filaments containing actins which probably function in the structural transformation of the nucleus.

[Effects of a warning signal on heart rate and 17-hydroxycorticosteroid in urine (author's transl)]

The purpose of this study was to test whether a warning signal given prior to an unpleasant stimulus would influence heart rate (HR) and 17-Hydroxycorticosteroid in urine (17-OHCS). The results for HR were as follows: (a) In the anticipation period, subjects given no warning signal (NS group) showed higher degree in their HR than that of those given a warning signal (S group), (b) On at impact, a warning signal tended to decrease subjects' HR when an unpleasant stimulus was given, (c) In the recovery period, subject group indicated lower degree in their HR than that of NS group, and (d) Subject group showed more adaptation by repeated trials to an unpleasant stimulus in their HR. However, as for urinary 17-OHC, nosignificant difference was observed.