Differences in the developmental origins of the periosteum may influence bone healing.

BACKGROUND AND OBJECTIVE: The jaw bone, unlike most other bones, is derived from neural crest stem cells, so we hypothesized that it may have different characteristics to bones from other parts of the body, especially in the nature of its periosteum. The periosteum exhibits osteogenic potential and has received considerable attention as a grafting material for the repair of bone and joint defects. MATERIAL AND METHODS: Gene expression profiles of jaw bone and periosteum were evaluated by DNA microarray and real-time polymerase chain reaction. Furthermore, we perforated an area 2 mm in diameter on mouse frontal and parietal bones. Bone regeneration of these calvarial defects was evaluated using microcomputed tomography and histological analysis. RESULTS: The DNA microarray data revealed close homology between the gene expression profiles within the ilium and femur. The gene expression of Wnt-1, SOX10, nestin, and musashi-1 were significantly higher in the jaw bone than in other locations. Microcomputed tomography and histological analysis revealed that the jaw bone had superior bone regenerative abilities than other bones. CONCLUSION: Jaw bone periosteum exhibits a unique gene expression profile that is associated with neural crest cells and has a positive influence on bone regeneration when used as a graft material to repair bone defects. A full investigation of the biological and mechanical properties of jaw bone as an alternative graft material for jaw reconstructive surgery is recommended.

Superhydrophobic surfaces: are they really ice-repellent?

This work investigates the anti-ice performance of various superhydrophobic surfaces under different conditions. The adhesion strength of glaze ice (similar to that deposited during "freezing rain") is used as a measure of ice-releasing properties. The results show that the ice-repellent properties of the materials deteriorate during icing/deicing cycles, as surface asperities appear to be gradually damaged. It is also shown that the anti-icing efficiency of superhydrophobic surfaces is significantly lower in a humid atmosphere, as water condensation both on top of and between surface asperities takes place, leading to significantly larger values of ice adhesion strength. This work thus shows that superhydrophobic surfaces are not always ice-repellent and their use as anti-ice materials may therefore be limited.

Re-evaluation of stomach position as a simple prognostic factor in fetal left congenital diaphragmatic hernia: a multicenter survey in Japan.

OBJECTIVES: To document outcome and to explore prognostic factors in fetal left congenital diaphragmatic hernia (CDH). METHODS: This was a multicenter retrospective study of 109 patients with prenatally diagnosed isolated left CDH born between 2002 and 2007. The primary outcome was intact discharge, defined as discharge from hospital without major morbidities, such as a need for respiratory support including oxygen supplementation, tube feeding, parenteral nutrition or vasodilators. All patients were managed at perinatal centers with immediate resuscitation, gentle ventilation (mostly with high-frequency oscillatory ventilation) and surgery after stabilization. Prenatal data collected included liver and stomach position, lung-to-head ratio, gestational age at diagnosis and presence or absence of polyhydramnios. Stomach position was classified into four grades: Grade 0, abdominal; Grade 1, left thoracic; Grade 2, less than half of the stomach herniated into the right chest; and Grade 3, more than half of the stomach herniated into the right chest. RESULTS: Overall intact discharge and 90-day survival rates were 65.1% and 79.8%, respectively. Stomach herniation was classified as Grade 0 in 19.3% of cases, Grade 1 in 45.9%, Grade 2 in 13.8% and Grade 3 in 21.1%. Multivariate analysis revealed that liver position was the strongest prognostic variable for intact discharge, followed by stomach position. Based on our results, we divided patients into three groups according to liver (up vs. down) and stomach (Grade 0-2 vs. Grade 3) position. Intact discharge rates declined significantly from liver-down (Group I), to liver-up with stomach Grade 0-2 (Group II), to liver-up with stomach Grade 3 (Group III) (87.0%, 47.4% and 9.5% of cases, respectively). CONCLUSION: Current status and outcomes of prenatally diagnosed left CDH in Japan were surveyed. Stomach herniation into the right chest was not uncommon and its grade correlated with outcome. The combination of liver and stomach positions was useful to stratify patients into three groups (Group I-III) with different prognoses.

Production of hydrogen peroxide by transforming growth factor-beta 1 and its involvement in induction of egr-1 in mouse osteoblastic cells.

TGF-beta 1 controls the expression of numerous genes, including early response and cellular matrix genes. However, the signal-transducing mechanism underlying this regulation of gene expression is not fully understood. In this study, we investigated whether redox regulation plays a role in the TGF-beta 1 signal transduction in the mouse osteoblastic cell line (MC3T3-E1). The overall intracellular oxidized state of the cells, when measured using 2',7'-dichlorofluorescin diacetate by laser-scanning confocal microscopy, was increased transiently after the addition of TGF-beta 1. This increase was abolished by the addition of oxygen radical scavengers such as catalase and N-acetylcysteine. In a variant cell line lacking the TGF-beta 1 receptor, the intracellular oxidized state was not modulated by treatment with TGF-beta 1. We then examined the expression of early growth response-1 (egr-1) gene, which is inducible by TGF-beta 1 and H2O2. Radical scavengers inhibited the induction of egr-1 by TGF-beta 1, but not that by 12-O-tetradecanoylphorbol-13 acetate. A nuclear run-on assay indicated that this inhibition was at the transcriptional level. From transient expression experiments using chloramphenicol acetyltransferase gene linked to serially deleted egr-1 gene 5'-upstream region, the CArG element in the 5' flanking region of egr-1 was identified as an essential sequence in the transcriptional activation for both TGF-beta 1 and H2O2 stimulation. These findings suggest that H2O2 acts as a mediator for the TGF-beta 1-induced transcription of egr-1 gene.

By-side PCDD/Fs in technical PCB formulations of Kanechlor series.

The Japanese Kanechlor technical PCB formulations such as KC-300, KC-400, KC-500, KC-600 and KC-1000 have been examined for possible contamination with by-side PCDD/Fs. 75 PCDDs and 135 PCDF have been determined using isotope dilution, separation and enrichment on silica gel impregnated with activated carbon, and final HRGC/HRMS measurement. MonoCDDs to OCDD were absent in KC-300, KC-600 and KC-1000. Tetra- and PentaCDDs occurred at > 1 ng/g in KC-400 and KC-500. The Kanechlors were contaminated with nearly all 135 PCDFsw. In parallel with an increasing degree of chlorination of a particular Kanechlor formulation examined increased also the content of more chlorinated PCDFs. In term of total dioxin-like toxicity and TEQ loads the KC-500 contained highly toxic PCDD/Fs at 270 ng TEQ/g and followed by KC-400 with 269 ng TEQ/g, KC-600 with 188 ng TEQ/g, KC-1000 with 164 ng TEQ/g and KC-300 with 79 ng TEQ/g. From 99.5 to 100% of PCDD/Fs toxicity found in the Kanechlors was from PCDFs.

Characterization of Jumping translocation breakpoint (JTB) gene product isolated as a TGF-beta1-inducible clone involved in regulation of mitochondrial function, cell growth and cell death.

Jumping translocation breakpoint (JTB) is a gene located on human chromosome 1 at q21 that suffers an unbalanced translocation in various types of cancers, and potentially encodes a transmembrane protein of unknown function. The results of cancer profiling indicated that its expression was suppressed in many cancers from different organs, implying a role in the neoplastic transformation of cells. Recently, we isolated JTB as a TGF-beta1-inducible clone by differential screening. In this study, we characterized its product and biological functions. We found that it was processed at the N-terminus and located mostly in mitochondria. When expressed in cells, JTB-induced clustering of mitochondria around the nuclear periphery and swelling of each mitochondrion. In those mitochondria, membrane potential, as monitored with a JC-1 probe, was significantly reduced. Coinciding with these changes in mitochondria, JTB retarded the growth of the cells and conferred resistance to TGF-beta1-induced apoptosis. These activities were dependent on the N-terminal processing and induced by wild-type JTB but not by a mutant resistant to cleavage. These findings raised the possibility that aberration of JTB in structure or expression induced neoplastic changes in cells through dysfunction of mitochondria leading to deregulated cell growth and/or death.

Extensive skin necrosis of the arm in a patient with complex regional pain syndrome.

We report a 36-year-old woman with complex regional pain syndrome (CRPS) type 1 presenting with extensive skin necrosis of the left arm. The patient cooled her arm with ice packs to ease severe pain due to CRPS, in spite of repeated cautions against frostbite injury. The regions of skin necrosis corresponded with the sites where she had applied ice packs. We considered that the severe skin necrosis in our case was due to a self-induced frostbite injury.

Arterial stiffness after successful renal transplantation.

Cardiovascular disease is a major barrier to the long-term survival of transplant recipients. The aim of this study was to determine whether successful renal transplantation improves the arterial stiffness resulting from chronic renal failure. This study involved a group of 9 recipients (23-56 years) who underwent successful renal transplantation at our clinic. The brachial-ankle pulse wave velocity and--intima-media thickness of the bilateral common carotid arteries were measured in each patient before and 1 year after successful renal transplantation. One year after renal transplantation, the 9 patients showed a mean serum creatinine level of 1.41 mg/dL. Assessment of arterial stiffness in this group revealed that the mean brachial-ankle pulse wave velocity was reduced after renal transplantation, but there was no reduction in the mean intima-media thickness of the bilateral common carotid arteries. There was a significant correlation between the variance ratios of pulse wave velocity and median blood pressure. The more effective blood pressure control provided by renal transplantation may functionally improve arterial stiffness. However, organic arterial stiffness remained unchanged 1 year after transplantation.

Efficacy of carvedilol for ischemia/reperfusion-induced oxidative renal injury in rats.

In renal transplantation, ischemia/reperfusion (I/R) injury is related to production of reactive oxygen species. In addition to its antihypertensive action due to nonselective beta-adrenergic blocking activity, carvedilol has potent antioxidant activity. This study was designed to investigate the effects of carvedilol on I/R injury in rats. On postoperative days 2 and 4, serum creatinine levels were higher among the control and the metoprolol treatment groups compared with the carvedilol treatment group (P < .005). However, there were no significant differences on postoperative day 7. In conclusion, increased antioxidant modulation by carvedilol attenuated renal I/R injury.

Hic-5-reduced cell spreading on fibronectin: competitive effects between paxillin and Hic-5 through interaction with focal adhesion kinase.

Hic-5 is a paxillin homologue that is localized to focal adhesion complexes. Hic-5 and paxillin share structural homology and interacting factors such as focal adhesion kinase (FAK), Pyk2/CAKbeta/RAFTK, and PTP-PEST. Here, we showed that Hic-5 inhibits integrin-mediated cell spreading on fibronectin in a competitive manner with paxillin in NIH 3T3 cells. The overexpression of Hic-5 sequestered FAK from paxillin, reduced tyrosine phosphorylation of paxillin and FAK, and prevented paxillin-Crk complex formation. In addition, Hic-5-mediated inhibition of spreading was not observed in mouse embryo fibroblasts (MEFs) derived from FAK(-/-) mice. The activity of c-Src following fibronectin stimulation was decreased by about 30% in Hic-5-expressing cells, and the effect of Hic-5 was restored by the overexpression of FAK and the constitutively active forms of Rho-family GTPases, Rac1 V12 and Cdc42 V12, but not RhoA V14. These observations suggested that Hic-5 inhibits cell spreading through competition with paxillin for FAK and subsequent prevention of downstream signal transduction. Moreover, expression of antisense Hic-5 increased spreading in primary MEFs. These results suggested that the counterbalance of paxillin and Hic-5 expression may be a novel mechanism regulating integrin-mediated signal transduction.

Induction of senescence-like phenotypes by forced expression of hic-5, which encodes a novel LIM motif protein, in immortalized human fibroblasts.

The hic-5 gene encodes a novel protein with Zn finger-like (LIM) motifs, the expression of which increases during cellular senescence. The ectopic expression of hic-5 in nontumorigenic immortalized human fibroblasts, whose expression levels of hic-5 were significantly reduced in comparison with those of mortal cells, decreased colony-forming efficiency. Stable clones expressing high levels of hic-5 mRNA showed higher levels of mRNAs for several extracellular matrix-related proteins, along with the alteration of an alternative splicing as seen in senescent cells and decreased c-fos inducibility. Furthermore, these clones acquired a senescence-like phenotype, such as growth retardation; senescence-like morphology; and increased expression of Cip1/WAF1/sdi1 after 20 to 40 population doublings. On the other hand, antisense RNA expression of hic-5 in human normal diploid fibroblasts delayed the senescence process. HIC-5 was localized in nuclei and had affinity for DNA. Based on these observations, we speculated that HIC-5 affected the expression of senescence-related genes through interacting with DNA and thereby induced the senescence-like phenotypes. To our knowledge, hic-5 is the first single gene that could induce senescence-like phenotypes in a certain type of immortalized human cell and mediate the normal process of senescence.

Stimulation by hydrogen peroxide of DNA synthesis, competence family gene expression and phosphorylation of a specific protein in quiescent Balb/3T3 cells.

Treatment of quiescent Balb/3T3 clone A31-1-1 cells with 0.1-0.2 mM H2O2 in the presence of 1 microM insulin induced DNA synthesis 20-24 h later at almost the same level as that in cells treated with 10% serum. Treatment with 0.1-0.2 mM H2O2 alone did not induce DNA synthesis and was not toxic to the cells. Cell cycle analysis indicated that treatment with H2O2 plus insulin induced progression of the cell cycle from the quiescent state. The amounts of mRNA for competence family genes such as c-fos, KC and JE were increased by the addition of H2O2. Under these conditions H2O2 caused rapid phosphorylation of a protein of 78 kDa with a pI of 6.3 (p78). Phosphorylation of p78 increased on treatment with TPA and serum as well. Catalase reduced the increase in phosphorylation of p78 induced by TPA and serum. Endogenous production of H2O2 was observed within 10 min after treatment of quiescent cells with platelet derived growth factor (PDGF) or 12-O-tetradecanoylphorbol-13-acetate (TPA). These results indicate that H2O2 at certain concentrations mimics the action of competence factors on resting Balb/3T3 cells.

Transcriptionally active and inactive genes are similarly modified by chemical carcinogens or X-ray in normal human fibroblasts.

Chemical carcinogens and ionizing radiation induce DNA modifications and strand breaks in cells. This damage is reported to be affected by chromatin proteins or chromatin of a higher structure order. To compare the sensitivity of transcriptionally active and inactive genes on chromatin toward DNA-damaging agents, we treated normal human fibroblasts (WI-38) cells in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), X-ray, 4-hydroxyaminoquinoline 1-oxide or N-acetoxy-2-acetylaminofluorene, and high molecular weight DNA was isolated. After digestion with EcoRI to completion, the DNA was electrophoresed on an alkaline agarose gel, blotted on a nitrocellulose filter and hybridized with a transcriptionally active gene probe (human type I(alpha 2) procollagen gene) or an inactive gene probe (human beta-globin gene). The results show that both genes are similarly modified by these agents. Repair of DNA damage caused by MNNG also occurred similarly in collagen and beta-globin genes after removal of MNNG.

Forced expression of hic-5, a senescence-related gene, potentiates a differentiation process of RCT-1 cells induced by retinoic acid.

The hic-5 gene encodes the novel LIM protein which has been implicated in cellular senescence and differentiation processes. Previous studies of rat calvarial cells stimulated to differentiate by addition of retinoic acid (R.A.) showed a four-fold increase in hic-5 expression which preceded an increase in the expression of the differentiation markers, alkaline phosphatase and alpha (I) pro-collagen mRNA. These data suggest involvement of hic-5 in osteoblast differentiation. This hypothesis was further examined using rat calvarial RCT-1 cells containing expression vectors of hic-5. The over-expressing clones showed a decrease in proliferation and displayed the differentiation-related phenotypes such as increased basal levels of alpha (I) collagen mRNA expression and high inducibility by R.A. of alkaline phosphatase activity. Conversely, introduction of hic-5 anti-sense vector leads to the inhibition of alpha (I) collagen mRNA following induction by R.A. These results suggest that hic-5 is one of the regulatory molecules involved in the R.A. induced differentiation process of RCT-1 cells.

Genomic structure and chromosomal mapping of the mouse hic-5 gene that encodes a focal adhesion protein.

The hic-5 gene encodes a focal adhesion protein that has striking similarity to paxillin. Genomic clones of the mouse hic-5 gene were isolated, and included 10 exons that covered the whole mouse mRNA sequence. Comparison of the sequence with those in the expressed sequence tag database suggested that the hic-5 gene contained an extra exon (named exon 1') located about 1kb upstream of exon 1, and mouse cells seemed to express two alternatively spliced forms of mRNA. All the exon-intron boundaries followed the GT/AG rule. Physical mapping and fluorescent in situ hybridization analysis indicated that the hic-5 gene is located on mouse chromosome 7, 60. 0cM from the centromere.

Distribution of nucleosomes on reconstituted chromatin from cloned mouse beta-globin DNA.

Relative abundance of nucleosomes on reconstituted chromatin was estimated with cloned mouse beta-globin gene DNA. Mononucleosomal DNA was isolated from reconstituted chromatin after digestion with micrococcal nuclease, nick-translated and used as a probe for blot hybridization. DNA fragments of restriction nuclease-digested globin DNA were transferred to DBM-paper and hybridized with mononucleosomal [32P] DNA probe. The results showed non-random distribution of nucleosomes.

Induction of c-fos proto-oncogene by a chemotactic peptide in human peripheral granulocytes.

The chemotactic peptide, fMet-Leu-Phe (fMLP), induced proto-oncogene c-fos mRNA in purified human peripheral granulocytes. The induction was transient, and was inhibited by pertussis toxin or by an inhibitor of protein kinase C. These results suggest that activation of a guanine nucleotide-binding protein and of protein kinase C is involved in c-fos induction in granulocytes.

Inhibition by N-acetyl-L-cysteine of interleukin-6 mRNA induction and activation of NF kappa B by tumor necrosis factor alpha in a mouse fibroblastic cell line, Balb/3T3.

Redox-based modulation plays a role in transcriptional control of gene expression. In the present study, we investigated the possible role of reactive oxygen species in the induction of interleukin-6 (IL-6) mRNA and in increases in NF kappa B binding activity by tumor necrosis factor (TNF) alpha using a mouse fibroblastic cell line, Balb/3T3. Expression of IL-6 mRNA is known to be dependent upon NF kappa B that binds to the 5'-flanking region of the IL-6 gene. We found that: (i) TNF alpha increased IL-6 mRNA levels and this increase was inhibited by N-acetyl-L-cysteine (NAC), a scavenger of reactive oxygen species. (ii) NF kappa B binding activity in this cell line was also increased by TNF alpha, and the increase was inhibited in the presence of NAC. (iii) The treatment of cells with low doses of hydrogen peroxide increased the NF kappa B binding activity. (iv) Expression of a reporter gene in which the chloramphenicol acetyltransferase (CAT) gene was under the control of NF kappa B binding sites was induced by hydrogen peroxide. These results suggest that the induction of IL-6 mRNA is regulated by a mechanism involving reactive oxygen species and that NF kappa B, whose activity is sensitive to the cellular redox state, plays an important role in this induction in a fibroblastic cell line, Balb/3T3, stimulated with TNF alpha.

Decrease in CuZn-superoxide dismutase mRNA level during differentiation of human monocytic and promyelotic leukemia cells.

Change in the level of CuZn-superoxide dismutase (SOD) mRNA was examined using a molecular probe during differentiation of human monocytic leukemia U937 cells or promyelotic leukemia HL-60 cells induced by either 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or dimethylsulfoxide (DMSO). CuZn-SOD mRNA levels were found to decrease during the course of differentiation, and this response is specific for differentiation, since the treatment of human B cell leukemia cells or normal diploid fibroblasts with TPA failed to have any effect on the level of CuZn-SOD mRNA. The activity of CuZn-SOD in U937 cells also decreased during differentiation, but following that of the CuZn-SOD mRNA level. The expression of the CuZn-SOD gene is thus concluded to diminish during the differentiation of HL-60 and U937 cells.