The luciferase-based in vivo protein-protein interaction assay revealed that CHK1 promotes PP2A and PME-1 interaction

Protein phosphatase 2A (PP2A) is an essential serine/threonine protein phosphatase, and its dysfunction is involved in the onset of cancer and neurodegenerative disorders. PP2A functions as a trimeric holoenzyme whose composition is regulated by the methyl-esterification (methylation) of the PP2A catalytic subunit (PP2Ac). Protein phosphatase methylesterase-1 (PME-1) is the sole PP2Ac methylesterase, and the higher PME-1 expression is observed in various cancer and neurodegenerative diseases. Apart from serving as a methylesterase, PME-1 acts as a PP2A inhibitory protein, binding directly to PP2Ac and suppressing its activity. The intricate function of PME-1 hinders drug development by targeting the PME-1/PP2Ac axis. This study applied the NanoBiT system, a bioluminescence-based protein interaction assay, to elucidate the molecular mechanism that modulates unknown PME-1/PP2Ac protein-protein interaction (PPI). Compound screening identified that the CHK1 inhibitors inhibited PME-1/PP2Ac association without affecting PP2Ac methylation levels. CHK1 directly phosphorylates PP2Ac to promote PME-1 association. Phospho-mass spectrometry identified multiple phospho-sites on PP2Ac, including the Thr219, that affect PME-1 interaction. An anti-phospho-Thr219 PP2Ac antibody was generated and showed that CHK1 regulates the phosphorylation levels of this site in cells. On the contrary, in vitro phosphatase assay showed that CHK1 is the substrate of PP2A, and PME-1 hindered PP2A-mediated dephosphorylation of CHK1. Our data provides novel insights into the molecular mechanisms governing the PME-1/PP2Ac PPI and the triad relationship between PP2A, PME-1, and CHK1.

ERK2-topoisomerase II regulatory axis is important for gene activation in immediate early genes

The function of the mitogen-activated protein kinase signaling pathway is required for the activation of immediate early genes (IEGs), including EGR1 and FOS, for cell growth and proliferation. Recent studies have identified topoisomerase II (TOP2) as one of the important regulators of the transcriptional activation of IEGs. However, the mechanism underlying transcriptional regulation involving TOP2 in IEG activation has remained unknown. Here, we demonstrate that ERK2, but not ERK1, is important for IEG transcriptional activation and report a critical ELK1 binding sequence for ERK2 function at the EGR1 gene. Our data indicate that both ERK1 and ERK2 extensively phosphorylate the C-terminal domain of TOP2B at mutual and distinctive residues. Although both ERK1 and ERK2 enhance the catalytic rate of TOP2B required to relax positive DNA supercoiling, ERK2 delays TOP2B catalysis of negative DNA supercoiling. In addition, ERK1 may relax DNA supercoiling by itself. ERK2 catalytic inhibition or knock-down interferes with transcription and deregulates TOP2B in IEGs. Furthermore, we present the first cryo-EM structure of the human cell-purified TOP2B and etoposide together with the EGR1 transcriptional start site (-30 to +20) that has the strongest affinity to TOP2B within -423 to +332. The structure shows TOP2B-mediated breakage and dramatic bending of the DNA. Transcription is activated by etoposide, while it is inhibited by ICRF193 at EGR1 and FOS, suggesting that TOP2B-mediated DNA break to favor transcriptional activation. Taken together, this study suggests that activated ERK2 phosphorylates TOP2B to regulate TOP2-DNA interactions and favor transcriptional activation in IEGs. We propose that TOP2B association, catalysis, and dissociation on its substrate DNA are important processes for regulating transcription and that ERK2-mediated TOP2B phosphorylation may be key for the catalysis and dissociation steps.

Cooperative DNA-binding activities of Chp2 are critical for its function in heterochromatin assembly

Heterochromatin protein 1 (HP1) is an evolutionarily conserved protein that plays a critical role in heterochromatin assembly. HP1 proteins share a basic structure consisting of an N-terminal chromodomain (CD) and a C-terminal chromoshadow domain (CSD) linked by a disordered hinge region. The CD recognizes histone H3 lysine 9 methylation, a hallmark of heterochromatin, while the CSD forms a dimer to recruit other chromosomal proteins. HP1 proteins have been shown to bind DNA or RNA primarily through the hinge region. However, how DNA or RNA binding contributes to their function remains elusive. Here, we focus on Chp2, one of the two HP1 proteins in fission yeast, and investigate how Chp2's DNA-binding ability contributes to its function. Similar to other HP1 proteins, the Chp2 hinge exhibits clear DNA-binding activity. Interestingly, the Chp2 CSD also shows robust DNA-binding activity. Mutational analysis revealed that basic residues in the Chp2 hinge and at the N-terminus of the CSD are essential for DNA binding, and the combined amino acid substitutions of these residues alter Chp2 stability, impair Chp2 heterochromatin localization and lead to a silencing defect. These results demonstrate that the cooperative DNA-binding activities of Chp2 play an important role in heterochromatin assembly in fission yeast.

Differential second messenger signaling via dopamine neurons bidirectionally regulates memory retention

Memory formation and forgetting unnecessary memory must be balanced for adaptive animal behavior. While cyclic AMP (cAMP) signaling via dopamine neurons induces memory formation, here we report that cyclic guanine monophosphate (cGMP) signaling via dopamine neurons launches forgetting of unconsolidated memory in Drosophila. Genetic screening and proteomic analyses showed that neural activation induces the complex formation of a histone H3K9 demethylase, Kdm4B, and a GMP synthetase, Bur, which is necessary and sufficient for forgetting unconsolidated memory. Kdm4B/Bur is activated by phosphorylation through NO-dependent cGMP signaling via dopamine neurons, inducing gene expression, including kek2 encoding a presynaptic protein. Accordingly, Kdm4B/Bur activation induced presynaptic changes. Our data demonstrate a link between cGMP signaling and synapses via gene expression in forgetting, suggesting that the opposing functions of memory are orchestrated by distinct signaling via dopamine neurons, which affects synaptic integrity and thus balances animal behavior.

GC-MS analysis of exhaled gas for fine detection of inflammatory diseases

Exhaled gas analysis is a non-invasive test ideal for continuous monitoring of biological metabolic information. We analyzed the exhaled gas of patients with inflammatory diseases for trace gas components that could serve as biomarkers that enable early detection of inflammatory diseases and assessment of treatment efficacy. Furthermore, we examined the clinical potential of this method. We enrolled 34 patients with inflammatory disease and 69 healthy participants. Volatile components from exhaled gas were collected and analyzed by a gas chromatography-mass spectrometry system, and the data were examined for gender, age, inflammatory markers, and changes in markers before and after treatment. The data were tested for statistical significance through discriminant analysis by Volcano plot, Analysis of variance test, principal component analysis, and cluster analysis comparing healthy and patient groups. There were no significant differences in the trace components of exhaled gas by gender or age. However, we found differences in some components of the exhaled gas between healthy and untreated patients. In addition, after treatment, gas patterns including the patient-specific components changed to a state closer to the inflammation-free status. We identified trace components in the exhaled gas of patients with inflammatory diseases and found that some of these regressed after treatment.

K63-linked polyubiquitination of LGP2 by Riplet regulates RIG-I-dependent innate immune response

Type I interferons (IFNs) exhibit strong antiviral activity and induce the expression of antiviral proteins. Since excessive expression of type I IFNs is harmful to the host, their expression should be turned off at the appropriate time. In this study, we find that post-translational modification of LGP2, a member of the RIG-I-like receptor family, modulates antiviral innate immune responses. The LGP2 protein undergoes K63-linked polyubiquitination in response to cytoplasmic double-stranded RNAs or viral infection. Our mass spectrometry analysis reveals the K residues ubiquitinated by the Riplet ubiquitin ligase. LGP2 ubiquitination occurs with a delay compared to RIG-I ubiquitination. Interestingly, ubiquitination-defective LGP2 mutations increase the expression of type I IFN at a late phase, whereas the mutant proteins attenuate other antiviral proteins, such as SP100, PML, and ANKRD1. Our data indicate that delayed polyubiquitination of LGP2 fine-tunes RIG-I-dependent antiviral innate immune responses at a late phase of viral infection.

Postnatal expression of cell cycle promoter Fam64a causes heart dysfunction by inhibiting cardiomyocyte differentiation through repression of Klf15

Introduction of fetal cell cycle genes into damaged adult hearts has emerged as a promising strategy for stimulating proliferation and regeneration of postmitotic adult cardiomyocytes. We have recently identified Fam64a as a fetal-specific cell cycle promoter in cardiomyocytes. Here, we analyzed transgenic mice maintaining cardiomyocyte-specific postnatal expression of Fam64a when endogenous expression was abolished. Despite an enhancement of cardiomyocyte proliferation, these mice showed impaired cardiomyocyte differentiation during postnatal development, resulting in cardiac dysfunction in later life. Mechanistically, Fam64a inhibited cardiomyocyte differentiation by repressing Klf15, leading to the accumulation of undifferentiated cardiomyocytes. In contrast, introduction of Fam64a in differentiated adult wildtype hearts improved functional recovery upon injury with augmented cell cycle and no dedifferentiation in cardiomyocytes. These data demonstrate that Fam64a inhibits cardiomyocyte differentiation during early development, but does not induce de-differentiation in once differentiated cardiomyocytes, illustrating a promising potential of Fam64a as a cell cycle promoter to attain heart regeneration.

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Overexpression of cell cycle promoter Fam64a in cardiomyocytes causes heart failure

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Fam64a inhibits cardiomyocyte differentiation during development by repressing Klf15

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Transient and local induction of Fam64a in adult hearts improves recovery upon injury

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Fam64a activates cardiomyocyte cell cycle without dedifferentiation upon injury

Relationship between distal radius fracture severity and 25-hydroxyvitamin-D level among perimenopausal and postmenopausal women

Aims

Low-energy distal radius fractures (DRFs) are the most common upper arm fractures correlated with bone fragility. Vitamin D deficiency is an important risk factor associated with DRFs. However, the relationship between DRF severity and vitamin D deficiency is not elucidated. Therefore, this study aimed to identify the correlation between DRF severity and serum 25-hydroxyvitamin-D level, which is an indicator of vitamin D deficiency.

Methods

This multicentre retrospective observational study enrolled 122 female patients aged over 45 years with DRFs with extension deformity. DRF severity was assessed by three independent examiners using 3D CT. Moreover, it was categorized based on the AO classification, and the degree of articular and volar cortex comminution was evaluated. Articular comminution was defined as an articular fragment involving three or more fragments, and volar cortex comminution as a fracture in the volar cortex of the distal fragment. Serum 25-hydroxyvitamin-D level, bone metabolic markers, and bone mineral density (BMD) at the lumbar spine, hip, and wrist were evaluated six months after injury. According to DRF severity, serum 25-hydroxyvitamin-D level, parameters correlated with bone metabolism, and BMD was compared.

Results

The articular comminuted group (n = 28) had a significantly lower median serum 25-hydroxyvitamin-D level than the non-comminuted group (n = 94; 13.4 ng/ml (interquartile range (IQR) 9.8 to 17.3) vs 16.2 ng/ml (IQR 12.5 to 20.4); p = 0.005). The AO classification and volar cortex comminution were not correlated with the serum 25-hydroxyvitamin-D level. Bone metabolic markers and BMD did not significantly differ in terms of DRF severities.

Conclusion

Articular comminuted DRF, referred to as AO C3 fracture, is significantly associated with low serum 25-hydroxyvitamin-D levels. Therefore, vitamin D₃ supplementation for vitamin D deficiency might prevent articular comminuted DRFs. Nevertheless, further studies must be conducted to validate the results of the current study.

Cite this article: Bone Jt Open 2022;3(3):261–267.

Seven Amino Acid Types Suffice to Create the Core Fold of RNA Polymerase

The extant complex proteins must have evolved from ancient short and simple ancestors. The double-ψ β-barrel (DPBB) is one of the oldest protein folds and conserved in various fundamental enzymes, such as the core domain of RNA polymerase. Here, by reverse engineering a modern DPBB domain, we reconstructed its plausible evolutionary pathway started by "interlacing homodimerization" of a half-size peptide, followed by gene duplication and fusion. Furthermore, by simplifying the amino acid repertoire of the peptide, we successfully created the DPBB fold with only seven amino acid types (Ala, Asp, Glu, Gly, Lys, Arg, and Val), which can be coded by only GNN and ARR (R = A or G) codons in the modern translation system. Thus, the DPBB fold could have been materialized by the early translation system and genetic code.

Cryo-EM structure of the human ELMO1-DOCK5-Rac1 complex

The dedicator of cytokinesis (DOCK) family of guanine nucleotide exchange factors (GEFs) promotes cell motility, phagocytosis, and cancer metastasis through activation of Rho guanosine triphosphatases. Engulfment and cell motility (ELMO) proteins are binding partners of DOCK and regulate Rac activation. Here, we report the cryo-electron microscopy structure of the active ELMO1-DOCK5 complex bound to Rac1 at 3.8-Å resolution. The C-terminal region of ELMO1, including the pleckstrin homology (PH) domain, aids in the binding of the catalytic DOCK homology region 2 (DHR-2) domain of DOCK5 to Rac1 in its nucleotide-free state. A complex α-helical scaffold between ELMO1 and DOCK5 stabilizes the binding of Rac1. Mutagenesis studies revealed that the PH domain of ELMO1 enhances the GEF activity of DOCK5 through specific interactions with Rac1. The structure provides insights into how ELMO modulates the biochemical activity of DOCK and how Rac selectivity is achieved by ELMO.

Deciphering the Proteotoxic Stress Responses Triggered by the Perturbed Thylakoid Proteostasis in Arabidopsis

Here, we explored heat dependent thylakoid FtsH protease substrates and investigated proteotoxicity induced by thermal damage and processive protease dysfunction on the thylakoid membrane. Through our thylakoid enriched proteome analysis and biochemical experiments, carbonylated stromal proteins were suggested as possible FtsH targets. Furthermore, we observed in the thylakoid fractions in the absence of FtsH stromal reactive oxygen species-detoxifying enzymes, as well as heat shock proteins and chaperones, which are known to be upregulated at the transcriptional level when this protease is absent, which is called the damaged protein response, resembling unfolded protein response in eukaryotic cells. Interestingly, the thylakoid-enriched high-density fractions included stromal translation factors and RNA-binding proteins, along with aminoacyl-tRNA synthetase, reminiscent of the formation of stress granules. Unexpectedly, extraplastid proteins such as mitochondrial chaperones, peroxidase, tricarboxylic acid cycle and respiratory chain enzymes, as well as cytosolic ribosomes, translation factors, heat shock proteins, antioxidants and metabolic enzymes, were also found deposited in the high-density fractions depending on the loss of thylakoid FtsH, with more prominent effects of thermal stress on the cytosolic proteins. This may reflect intracellular adaptation to the proteotoxic influences from the organelle.

Cryo-EM structure of the CENP-A nucleosome in complex with phosphorylated CENP-C

The CENP-A nucleosome is a key structure for kinetochore assembly. Once the CENP-A nucleosome is established in the centromere, additional proteins recognize the CENP-A nucleosome to form a kinetochore. CENP-C and CENP-N are CENP-A binding proteins. We previously demonstrated that vertebrate CENP-C binding to the CENP-A nucleosome is regulated by CDK1-mediated CENP-C phosphorylation. However, it is still unknown how the phosphorylation of CENP-C regulates its binding to CENP-A. It is also not completely understood how and whether CENP-C and CENP-N act together on the CENP-A nucleosome. Here, using cryo-electron microscopy (cryo-EM) in combination with biochemical approaches, we reveal a stable CENP-A nucleosome-binding mode of CENP-C through unique regions. The chicken CENP-C structure bound to the CENP-A nucleosome is stabilized by an intramolecular link through the phosphorylated CENP-C residue. The stable CENP-A-CENP-C complex excludes CENP-N from the CENP-A nucleosome. These findings provide mechanistic insights into the dynamic kinetochore assembly regulated by CDK1-mediated CENP-C phosphorylation.

Bridgin connects the outer kinetochore to centromeric chromatin

The microtubule-binding outer kinetochore is coupled to centromeric chromatin through CENP-C^Mif2, CENP-T^Cnn1, and CENP-U^Ame1 linker pathways originating from the constitutive centromere associated network (CCAN) of the inner kinetochore. Here, we demonstrate the recurrent loss of most CCAN components, including certain kinetochore linkers during the evolution of the fungal phylum of Basidiomycota. By kinetochore interactome analyses in a model basidiomycete and human pathogen Cryptococcus neoformans, a forkhead-associated domain containing protein “bridgin” was identified as a kinetochore component along with other predicted kinetochore proteins. In vivo and in vitro functional analyses of bridgin reveal its ability to connect the outer kinetochore with centromeric chromatin to ensure accurate chromosome segregation. Unlike established CCAN-based linkers, bridgin is recruited at the outer kinetochore establishing its role as a distinct family of kinetochore proteins. Presence of bridgin homologs in non-fungal lineages suggests an ancient divergent strategy exists to bridge the outer kinetochore with centromeric chromatin.

The kinetochore is a multi-complex structure that helps attach chromosomes to spindle microtubules, ensuring accurate chromosome segregation during cell division. Kinetochores are thought to be evolutionarily conserved, but which components are conserved is unclear. Here, the authors report that some members of the fungal phylum of Basidomycota lack many conventional kinetochore linker proteins. Instead, they possess a human Ki67-like protein that bridges the outer part of the kinetochore to centromere DNA, which may compensate for the loss of a conventional linker.

Reinvestigation of the virulence of Rhodococcus equi isolates from patients with and without AIDS

Rhodococcus equi emerged as a zoonotic pathogen of human immunodeficiency virus-infected patients over the last three decades. Two virulence plasmid types of R. equi, pVAPA and pVAPB associated with equine and porcine isolates, have been recognized, and more recently, pVAPN, a novel host-associated virulence plasmid in R. equi, was found in bovine and caprine isolates. We reinvestigated 39 previously reported isolates of R. equi from patients with and without acquired immunodeficiency syndrome (AIDS) by detecting vapA, vapB and vapN using PCR and plasmid profiling. After excluding one isolate that could not be cultured from frozen storage, eight isolates carried a virulence plasmid encoding vapA (pVAPA), 10 carried a virulence plasmid encoding vapB (pVAPB), seven carried a virulence plasmid encoding vapN (pVAPN) and 13 were negative for those genes. Of the 29 isolates from patients with AIDS, 7, 10 and 5 harboured pVAPA, pVAPB and pVAPN respectively. Among nine isolates from patients without AIDS, one and two harboured pVAPA and pVAPN respectively. This study demonstrated that pVAPN-positive R. equi existed in human isolates before 1994 and reaffirmed that equine-associated pVAPA-positive, porcine-associated pVAPB-positive and bovine- or caprine-associated pVAPN-positive R. equi are widely spread globally. Because domestic animals might be major sources of human infection, further research is needed to reveal the prevalence of pVAPN-positive R. equi infection in cattle and goats.

Structural basis for histone variant H3tK27me3 recognition by PHF1 and PHF19

The Polycomb repressive complex 2 (PRC2) is a multicomponent histone H3K27 methyltransferase complex, best known for silencing the Hox genes during embryonic development. The Polycomb-like proteins PHF1, MTF2, and PHF19 are critical components of PRC2 by stimulating its catalytic activity in embryonic stem cells. The Tudor domains of PHF1/19 have been previously shown to be readers of H3K36me3 in vitro. However, some other studies suggest that PHF1 and PHF19 co-localize with the H3K27me3 mark but not H3K36me3 in cells. Here, we provide further evidence that PHF1 co-localizes with H3t in testis and its Tudor domain preferentially binds to H3tK27me3 over canonical H3K27me3 in vitro. Our complex structures of the Tudor domains of PHF1 and PHF19 with H3tK27me3 shed light on the molecular basis for preferential recognition of H3tK27me3 by PHF1 and PHF19 over canonical H3K27me3, implicating that H3tK27me3 might be a physiological ligand of PHF1/19.

Estimation of 1992–1993 Dietary Intake of Organochlorine and Organophosphorus Pesticides in Fukuoka, Japan

To estimate Japanese daily intakes of organochlorine pesticides such as hexachlorocyclohexanes (HCHs), 1,1,1 -trichloro-2,2-bis-(4-chlorophenyl)-ethane (DDTs), dieldrin (aldrin), heptachlor-epoxide (heptachlor), and hexachlorobenzenes (HCBs) from foods, fish, fish products, meat, eggs, milk, and milk products were analyzed as major sources of these pesticides in the diet. Estimated daily intakes (EDIs) per person were 0.56 μg for total HCH, 0.20 μg for γ-HCH, 0.09 μg for dieldrin, 1.42 μg for total DDT, and 0.15 μg for HCB. Similarly, daily intakes of organophosphorus pesticides such as malathion and chlorpyrifosmethyl were estimated by analyzing wheat and wheat products as major contributing foods. EDIs of malathion and chlorpyrifos-methyl were 0.22 and 0.24 μg, respectively. Daily intakes of total HCH, dieldrin, and total DDT in fiscal year 1992–1993 decreased 29,44, and 40%, respectively, but γ-HCH intake increased 167%, in comparison with results of total diet studies for fiscal years 1980–1984. It was also shown that increase in γ-HCH intake was due to recent increase in consumption of imported meat and meat products. Malathion intake did not change significantly. This method, which estimates EDIs based on concentrations of pollutants in main foods and statistical data of food consumption from the Japanese National Nutrition Survey, is considered to be sufficiently accurate for use as a simplified total diet study.

H3K14 ubiquitylation promotes H3K9 methylation for heterochromatin assembly

The methylation of histone H3 at lysine 9 (H3K9me), performed by the methyltransferase Clr4/SUV39H, is a key event in heterochromatin assembly. In fission yeast, Clr4, together with the ubiquitin E3 ligase Cul4, forms the Clr4 methyltransferase complex (CLRC), whose physiological targets and biological role are currently unclear. Here, we show that CLRC-dependent H3 ubiquitylation regulates Clr4's methyltransferase activity. Affinity-purified CLRC ubiquitylates histone H3, and mass spectrometric and mutation analyses reveal that H3 lysine 14 (H3K14) is the preferred target of the complex. Chromatin immunoprecipitation analysis shows that H3K14 ubiquitylation (H3K14ub) is closely associated with H3K9me-enriched chromatin. Notably, the CLRC-mediated H3 ubiquitylation promotes H3K9me by Clr4, suggesting that H3 ubiquitylation is intimately linked to the establishment and/or maintenance of H3K9me. These findings demonstrate a cross-talk mechanism between histone ubiquitylation and methylation that is involved in heterochromatin assembly.

The effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament reconstruction: An animal study

Objectives

To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model.

Methods

Anterior cruciate ligament reconstruction using the plantaris tendon as graft material was performed on both knees of 24 rabbits (48 knees) to mimic ACL reconstruction by two different suspensory fixation devices for graft fixation. For the adjustable fixation device model (Socket group; group S), a 5 mm deep socket was created in the lateral femoral condyle (LFC) of the right knee. For the fixed-loop model (Tunnel group; group T), a femoral tunnel penetrating the LFC was created in the left knee. Animals were sacrificed at four and eight weeks after surgery for histological evaluation and biomechanical testing.

Results

Histologically, both groups showed a mixture of direct and indirect healing patterns at four weeks, whereas only indirect healing patterns were observed in both groups at eight weeks. No significant histological differences were seen between the two groups at four and eight weeks in the roof zone (four weeks, S: mean 4.8 sd 1.7, T: mean 4.5 sd 0.5, p = 0.14; eight weeks, S: mean 5.8 sd 0.8, T: mean 4.8 sd 1.8, p = 0.88, Mann-Whitney U test) or side zone (four weeks, S: mean 5.0 sd 1.2, T: mean 4.8 sd 0.4, p = 0.43; eight weeks, S: mean 5.3 sd 0.8,T: mean 5.5 sd 0.8, p = 0.61, Mann-Whitney U test) . Similarly, no significant difference was seen in the maximum failure load between group S and group T at four (15.6 sd 9.0N and 13.1 sd 5.6N) or eight weeks (12.6 sd 3.6N and 17.1 sd 6.4N, respectively).

Conclusion

Regardless of bone tunnel configuration, tendon-bone healing after ACL reconstruction primarily occurred through indirect healing. No significant histological or mechanical differences were observed between adjustable and fixed-loop femoral cortical suspension methods.

Cite this article: Y. Sato, R. Akagi, Y. Akatsu, Y. Matsuura, S. Takahashi, S. Yamaguchi, T. Enomoto, R. Nakagawa, H. Hoshi, T. Sasaki, S. Kimura, Y. Ogawa, A. Sadamasu, S. Ohtori, T. Sasho. The effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament reconstruction: An animal study. Bone Joint Res 2018;7:327–335. DOI: 10.1302/2046-3758.75.BJR-2017-0238.R2.

Optimization of antimicrobial therapy in vancomycin-resistant enterococcal bacteraemia using a rapid detection Gram-positive blood culture assay

Rapid molecular blood culture Gram-positive (BC-GP) assay can promptly identify vancomycin-resistant enterococcal (VRE) bloodstream infections (BSIs). We sought to evaluate patients with VRE BSI following the pre (N = 44) and post (N = 20) implementation of Verigene BC-GP assay. The average time to detection of VRE was 25.9 ± 4.1h (95% confidence interval (CI): 17.6-34.1; P < 0.001) earlier with Verigene BC-GP assay. Compared to patients in the pre-Verigene BC-GP period, the mean adjusted difference in time to administration of anti-VRE therapy was 18.2 ± 7.8h (95% CI: 2.5-33.8; P = 0.024) earlier among patients in the post-Verigene BC-GP period.

The recognition and incidence of peroneal tendon dislocation associated with a fracture of the talus

AIMS

The purposes of this study were to clarify first, the incidence of peroneal tendon dislocation in patients with a fracture of the talus and second the factors associated with peroneal tendon dislocation.

PATIENTS AND METHODS

We retrospectively examined 30 patients (30 ankles) with a mean age of 37.5 years, who had undergone internal fixation for a fracture of the talus. Independent examiners assessed for peroneal tendon dislocation using the pre-operative CT images. The medical records were also reviewed for the presence of peroneal tendon dislocation. The associations between the presence of dislocation with the patient characteristics or radiological findings, including age, mechanism of injury, severity of fracture, and fleck sign, were assessed using Fisher's exact tests.

RESULTS

The pre-operative CT images showed peroneal tendon dislocation in eight out of 30 patients. Dislocation was found later in one patient whose pre-operative CT image had not shown dislocation. The overall incidence of peroneal tendon dislocation was 30% (9/30). The presence of dislocation was associated with the presence of a fleck sign (p = 0.03).

CONCLUSIONS

Surprisingly, approximately one-third of the patients who underwent internal fixation for a fracture of the talus had peroneal tendon dislocation. This was associated with a fleck sign. Cite this article: Bone Joint J 2017;99-B:489-93.

The effect of systemic administration of G-CSF on a full-thickness cartilage defect in a rabbit model MSC proliferation as presumed mechanism: G-CSF for cartilage repair

Objectives

The aim of this study was to investigate the effect of granulocyte-colony stimulating factor (G-CSF) on mesenchymal stem cell (MSC) proliferation in vitro and to determine whether pre-microfracture systemic administration of G-CSF (a bone marrow stimulant) could improve the quality of repaired tissue of a full-thickness cartilage defect in a rabbit model.

Methods

MSCs from rabbits were cultured in a control medium and medium with G-CSF (low-dose: 4 μg, high-dose: 40 μg). At one, three, and five days after culturing, cells were counted. Differential potential of cultured cells were examined by stimulating them with a osteogenic, adipogenic and chondrogenic medium.

A total of 30 rabbits were divided into three groups. The low-dose group (n = 10) received 10 μg/kg of G-CSF daily, the high-dose group (n = 10) received 50 μg/kg daily by subcutaneous injection for three days prior to creating cartilage defects. The control group (n = 10) was administered saline for three days. At 48 hours after the first injection, a 5.2 mm diameter cylindrical osteochondral defect was created in the femoral trochlea. At four and 12 weeks post-operatively, repaired tissue was evaluated macroscopically and microscopically.

Results

The cell count in the low-dose G-CSF medium was significantly higher than that in the control medium. The differentiation potential of MSCs was preserved after culturing them with G-CSF.

Macroscopically, defects were filled and surfaces were smoother in the G-CSF groups than in the control group at four weeks. At 12 weeks, the quality of repaired cartilage improved further, and defects were almost completely filled in all groups. Microscopically, at four weeks, defects were partially filled with hyaline-like cartilage in the G-CSF groups. At 12 weeks, defects were repaired with hyaline-like cartilage in all groups.

Conclusions

G-CSF promoted proliferation of MSCs in vitro. The systemic administration of G-CSF promoted the repair of damaged cartilage possibly through increasing the number of MSCs in a rabbit model.

Cite this article: T. Sasaki, R. Akagi, Y. Akatsu, T. Fukawa, H. Hoshi, Y. Yamamoto, T. Enomoto, Y. Sato, R. Nakagawa, K. Takahashi, S. Yamaguchi, T. Sasho. The effect of systemic administration of G-CSF on a full-thickness cartilage defect in a rabbit model MSC proliferation as presumed mechanism: G-CSF for cartilage repair. Bone Joint Res 2017;6:123–131. DOI: 10.1302/2046-3758.63.BJR-2016-0083.

Positive association of free triiodothyronine with pancreatic β-cell function in people with prediabetes

AIM

To analyse the effects of thyroid hormones on β-cell function and glucose metabolism in people with prediabetes who are euthyroid.

METHODS

A total of 111 people who were euthyroid underwent 75-g oral glucose tolerance tests, of whom 52 were assigned to the normal glucose tolerance and 59 to the prediabetes groups. Homeostatic model assessment of β-cell function, insulinogenic index and areas under the curve for insulin and glucose were evaluated as indices of pancreatic β-cell function.

RESULTS

In both groups, BMI, fasting insulin, homeostasis model assessment ratio and HDL cholesterol correlated significantly with all indices of pancreatic β-cell function. Free triiodothyronine correlated positively with all insulin secretion indices in the prediabetes group. Multiple linear regression analysis showed that free triiodothyronine was an independent variable that had a positive correlation with all indices of β-cell function in the prediabetes group. By contrast, no such correlation was found in the normal glucose tolerance group.

CONCLUSIONS

Free triiodothyronine is associated with both basal and glucose-stimulated insulin secretion in people with prediabetes who are euthyroid; therefore, the regulation of insulin secretion by thyroid hormones is a potentially novel therapeutic target for the treatment of diabetes.

N-terminal phosphorylation of HP1α increases its nucleosome-binding specificity

Heterochromatin protein 1 (HP1) is an evolutionarily conserved chromosomal protein that binds to lysine 9-methylated histone H3 (H3K9me), a hallmark of heterochromatin. Although HP1 phosphorylation has been described in several organisms, the biological implications of this modification remain largely elusive. Here we show that HP1's phosphorylation has a critical effect on its nucleosome binding properties. By in vitro phosphorylation assays and conventional chromatography, we demonstrated that casein kinase II (CK2) is the kinase primarily responsible for phosphorylating the N-terminus of human HP1α. Pull-down assays using in vitro-reconstituted nucleosomes showed that unmodified HP1α bound H3K9-methylated and H3K9-unmethylated nucleosomes with comparable affinity, whereas CK2-phosphorylated HP1α showed a high specificity for H3K9me3-modified nucleosomes. Electrophoretic mobility shift assays showed that CK2-mediated phosphorylation diminished HP1α's intrinsic DNA binding, which contributed to its H3K9me-independent nucleosome binding. CK2-mediated phosphorylation had a similar effect on the nucleosome-binding specificity of fly HP1a and S. pombe Swi6. These results suggested that HP1 phosphorylation has an evolutionarily conserved role in HP1's recognition of H3K9me-marked nucleosomes.

The Upf factor complex interacts with aberrant products derived from mRNAs containing a premature termination codon and facilitates their proteasomal degradation

Up-frameshift (Upf) factors eliminate aberrant mRNAs containing a specific premature termination codon (PTC). Here, we show that Upf complex facilitates the ubiquitin-dependent degradation of products derived from mRNA containing specific PTCs in Saccharomyces cerevisiae. The efficiency of recruitment of the Upf complex to a PTC product was correlated with the decay of the PTC product. Upf factors promoted the degradation of the human von Hippel-Lindau (VHL) protein, which is an unfolded protein in yeast cells, in a manner that depends on the presence of a faux 3'-UTR. Mass spectrometric analysis and Western blot analysis revealed that Hsp70 was associated with the PTC product. These findings suggest that the Upf complex may be recruited to ribosomes in a faux 3'-UTR-dependent manner and then associates with aberrant products to facilitate their degradation by the proteasome.

Mediator complex recruits epigenetic regulators via its two cyclin-dependent kinase subunits to repress transcription of immune response genes

The Mediator complex (Mediator) plays pivotal roles in activating transcription by RNA polymerase II, but relatively little is known about its roles in repression. Here, we identified the histone arginine methyltransferase PRMT5 and WD repeat protein 77/methylosome protein 50 (WDR77/MEP50) as Mediator cyclin-dependent kinase (CDK)-interacting proteins and studied the roles of PRMT5 in the transcriptional regulation of CCAAT enhancer-binding protein (C/EBP) β target genes. First, we purified CDK8- and CDK19-containing complexes from HeLa nuclear extracts and subjected these purified complexes to mass spectrometric analyses. These experiments revealed that two Mediator CDKs, CDK8 and CDK19, individually interact with PRMT5 and WDR77, and their interactions with PRMT5 cause transcriptional repression of C/EBPβ target genes by regulating symmetric dimethylation of histone H4 arginine 3 (H4R3me2s) in the promoter regions of those genes. Furthermore, the recruitment of the DNA methyltransferase DNMT3A correlated with H4R3 dimethylation potentially leading to DNA methylation at the promoter proximal region and tight inhibition of preinitiation complex formation. In vertebrates, C/EBPβ regulates many genes involved in immune responses and cell differentiation. These findings shed light on the molecular mechanisms of the repressive roles of Mediator CDKs in transcription of C/EBPβ target genes and might provide clues that enable future studies of the functional associations between Mediators and epigenetic regulation.

Risk factors for postoperative mortality and morbidities in emergency surgeries

BACKGROUND

Emergency surgery itself induces high risk for postoperative mortality and morbidities; however, it remains unknown which concomitant pathological conditions of emergency surgeries are causative factors of deteriorating outcomes. This study examined the causal factors of postoperative mortality and morbidity in cases of emergency surgery.

METHODS

Patients undergoing emergency surgery from January to December 2007 were enrolled in this retrospective cohort study. Causal relationships were analyzed by stepwise multivariate logistic regression analysis between possible independent factors (sex, age, kind of surgical department, timing of surgery, duration of surgery, blood transfusion, deteriorated consciousness level, shock state, abnormal coagulate state, and history of hypertension, diabetes, ischemic heart disease, chronic obstructive pulmonary disease, renal failure, and anemia) and postoperative mortality or morbidities (failure of removal of tracheal tube after operation, tracheotomy, cerebral infarction, massive hemorrhage, severe hypotension, severe hypoxemia, and severe arrhythmia during or after surgery).

RESULTS

Shock, deteriorated consciousness level, chronic obstructive lung disease, and ischemic heart disease were significant risk factors for mortality (OR 14.2, 7.9, 6.4, and 3.8, respectively), and deteriorated consciousness level, blood transfusion, shock, chronic obstructive lung disease, diabetes, cardiovascular surgery, and operation longer than 2 h were significant risk factors for morbidity (OR 19.1, 3.3, 3.0, 2.5, 2.4, 2.4, and 1.8, respectively).

CONCLUSION

State of shock, deteriorated consciousness level, chronic obstructive lung disease, ischemic heart disease, hemorrhage requiring blood transfusion, age over 80 years, cardiovascular surgery, surgeries at night, and surgeries of duration more than 2 h cause patients to be strongly susceptible to postoperative mortality or morbidity in emergency surgeries.

Development of ICF code selection tools for mental health care

BACKGROUND

The International Classification of Functioning, Disability and Health (ICF) has been available as a means of coding life functions but the coding process is cumbersome due to the large number of ICF codes. In the current study, we developed ICF code selection tools to support the coding of activity and participation data recorded in domiciliary mental health care reports.

METHODS

We first developed a search system to facilitate the selection of ICF codes by tracking back through codes' conceptual trees using a directory tool. We performed a morphological analysis on the training data set to correlate nouns with the ICF codes and obtained an analysis corpus to which numerical scores representing the frequencies of associated ICF codes for each noun were assigned. Based on the obtained corpus we developed a full-text search tool, which could simplify ICF coding relative to that performed using the directory tool. We then evaluated the usefulness of the former tool on the test data set.

RESULTS

Using the full-text search tool, correct ICF codes were recorded in the first candidate list for only 54.2% of sentences. However, correct ICF codes appeared on the combined candidate lists for 90.1% of sentences and on the top three candidate lists for 71.7%. In a specific case (General Tasks and Demands), 100% of the correct codes were included on the combined candidate lists.

CONCLUSION

We developed selection tools that effectively supported ICF coding, although it was impossible to fully automate ICF coding. This indicated that ICF codes could more effectively be applied to mental health care.

Abstract P4-10-11: Nobel Approach for Breast Conserving Surgery after Primary Systemic Therapy: Real-Time Virtual Navigation

Background:

Breast-conserving surgery after primary systemic therapy (PST) has become a widely acceptable procedure for locally advanced breast cancers. Sometimes it is difficult to determine the appropriate resection-line at the time of surgical operation because of tumor size reduction or indistinct boundary of the tumor. Moreover we cannot detect tumors in cases with complete response. That was why we developed a new navigation technique using real-time image reconstruction.

Materials and methods: Multi-detector row computed tomography (MD-CT) has been performed for all breast cancer patients in our institute. DICOM images of MD-CT were analyzed by image processing software ‘OsiriX'. OsiriX is an open source software which anyone can download from website (http://www. osirix-viewer.com). OsiriX has been specifically designed for navigation and visualization of multimodality and multidimensional images. We used 3D volume rendering images. At the time of surgery, pre-PST volume rendering images ware superimposed directly on the patients’ skin from projector which was connected to a personal computer in the operating room.

Results: We could see ‘real-time’ rendering images (from skin to organ by layer to layer) on the patient's body. By using pre-PST imaging data, we could recognize precise tumor area and could perform breast conserving surgery safer and easier than before.

Conclusion: Using 3D reconstruction MD-CT images which were obtained before PST, ‘real-time’ virtual navigation was helpful to determine the resection-line for clear surgical margin in breast-conserving surgery after PST. This new technique does not need some expensive equipments and easily performed by surgeon. Ordinary personal computer and projector make it possible to demonstrate a new environment in surgical operation.

Hexabromocyclododecane determination in seafood samples collected from Japanese coastal areas

The levels of three hexabromocyclododecane (HBCD) isomers and ΣHBCDs in 54 wild and 11 farmed seafood samples collected from four regions of Japan were determined by LC/MS/MS. For the fish classified as Anguilliformes, Perciformes, Clupeiformes and farmed Salmoniformes, the medians (ranges) of ΣHBCDs are 2.09 (0.05-36.9), 0.75 (ND-26.2), 0.12 (0.09-77.3) and 1.29 (1.09-1.34) ng g(-1)ww, respectively. However, HBCDs were not detected in samples classified as Crustacea, Mollusca, Pleuronectiformes and Scorpaeniformes, or if detected, the levels were very low. The rank correlation between ΣHBCDs (or α-HBCD) and fat content could not be found except for the Japanese sea bass of the Tohoku region. In HBCD isomer profiles, for fish samples above 20 ng g(-1)ww, the trend was found that γ-HBCD was predominant, which suggests the influence of discharge from a nearby industrial plant. In the other wild fish and the farmed fish samples, on the other hand, α-HBCD was mostly predominant, which suggests biomagnification via the food chain. Additionally, to assess the risk to human health, based on the determined HBCD median concentrations for Anguilliformes, farmed Salmoniformes and Perciformes, the daily intake of HBCDs from fish by an average Japanese adult was tentatively calculated to be 3.7, 2.3 and 1.3 ng (kg body weight)(-1) d(-1), respectively.

[Dioxin concentration in the preserved umbilical cord from Yusho patients]

Dioxins are known as endocrine disrupters and widespread environmental contaminants. They are bioaccumulated in the human body. In this study, we determined concentrations of dioxins (PCDD, PCDF, Non-ortho PCB and Mono-ortho PCB) in eighteen umbilical cords provided by twelve mothers of Yusho patients and twelve umbilical cords provided by ten mothers of normal controls. The average concentrations of PCDD, PCDF, Non-ortho PCB, Mono-ortho PCB and total dioxins (PCDD/ F + Dioxin-like PCB) in the umbilical cords of Yusho patients and normal controls were 0.55, 4.55, 0.08, 0.08 and 5.26 pg-TEQ/g, respectively, and 0.50, 0.11, 0.03, 0.02 and 0.66 pg-TEQ/g, respectively. Total dioxins and PCDF concentrations in the umbilical cords of Yusho patient were about 8 and 40 times higher than those in the umbilical cords of normal controls, respectively. The average concentration of 2,3,4,7,8-PeCDF in the umbilical cords of Yusho patients was 10 pg/g. We couldn't detect 2,3,4,7, 8-PeCDF in the umbilical cords of normal controls. We suspected the 2,3,4,7,8-PeCDF concentrations in the mothers' blood were related to the 2,3,4,7,8-PeCDF concentrations in umbilical cords.

[Analysis of polychlorinated quaterphenyls in Yusho diagnosis in 2005]

The polychlorinated quaterphenyl (PCQ) concentrations in the blood are important discriminative parameters in Yusho patients. The blood samples of 81 persons were analyzed for PCQ in the 2005 annual inspection for Kanemi rice oil poisoning. PCQ was detected in 28 blood samples (ranging from 0.02 to 4.05 ppb). The means of PCQ concentration in the blood were 1.80 ppb (0.33-4.05 ppb) in pattern A, 0.71 ppb (<0.02-2.26 ppb) in pattern B, 0.03 ppb (< 0. 02-0.14 ppb) in pattern BC and 0.02 ppb (<0.02-0.45 ppb) in pattern C, respectively. PCQ was still present at high concentration in the blood of patterns A and B. Since PCQ concentration is a useful diagnostic criteria, it is important to follow up on this survey of blood PCQ levels.

[Blood PCB concentrations and their characteristics examined in Fukuoka 2006 annual inspection for Yusho]

We analyzed sixty-eight PCB isomers and determined their concentrations and characteristics in fifty-eight individual blood samples collected during the annual Yusho inspection in 2006. The method used in this study consists of a rapid GPC clean-up and sensitive PCB isomer-specific identification with HRGC/HRMS. As a result, the highest total PCB concentration in inspected subjects was 6.6 ppb on a blood weight basis, which was 8.1 times higher than that of a control blood sample. When blood PCB patterns were compared among twenty-seven persons in undergoing examinations both 2004 and 2006, the longitudinal classifications in the respective individuals hardly changed between these years. Mean concentrations of each PCB isomer in the blood of pattern A subjects (n=4) were compared with those in the blood collected from Fukuoka prefecture residents (n=127). Consequently, the respective blood concentrations of PCB #157, #156, #189, #137, #195, #170, #99 were obviously higher than those of Fukuoka residents, while those of PCB #118, # 05 was evidently lower than those of Fukuoka residents.

Immunologic effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides in Japanese infants

Effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides on lymphocyte subsets were investigated in the peripheral blood from 101 Japanese infants with approximately 10 months of age. Perinatal exposure to these organochlorine compounds were estimated by their contamination levels in the breast milk of the mothers. Lymphocyte subsets such as CD16+, HLA-DR+, CD4+, CD4+8+, CD8+, CD3+ and CD20+ cells in peripheral venous blood were assessed in a subgroup of 92 infants. Greater exposures to HCE, chlordane and dioxins were significantly associated with the increase in the percentages of CD8+ and CD3+ T lymphocytes and CD4+/CD8+ T cell ratios, respectively. In addition, higher HCH exposure was also associated with a decrease in the percentage of HLA-DR+ T lymphocytes. Furthermore effects of dioxins, DDT and PCBs on the percentage of CD16+ T lymphocyte were more pronounced by the combined exposure of dioxins and PCBs or by the combined exposure of DDT and PCBs. Effects of HCE on the percentages of CD8+ T lymphocyte were also more pronounced by the combined exposure of HCE and chlordane. In conclusion, our study suggests that greater exposures to dioxins, PCBs and organochlorine pesticides determined in this study (except dieldrin) influence the immune system of Japanese infant, although the clinical significance of these changes is uncertain.

Bronchoscopy-guided radiofrequency ablation as a potential novel therapeutic tool

The aim of the current study was to assess the safety of bronchoscopy-guided radiofrequency ablation (RFA) and compare the effectiveness between new internal cooled-RFA and standard noncooled-RFA. Normal lungs from sheep were used (n=6). Internal cooled-RFA and standard noncooled-RFA were set to assess the most suitable RFA conditions, such as power output, flow rate and ablation time. Internal cooled-RFA was then applied under the most optimal conditions of power output and flow rate for 15, 30, 60 and 120 s, and two water temperatures either room temperature (RT) water or cold water. Criteria for the most appropriate conditions were set over 15 s of ablation time and 50 degrees C of the tip's temperature. Internal cooled-RFA had no complications. Standard noncooled-RFA was complicated with bronchial bleeding after RFA. On the basis of the histological findings, average temperature and average output, the most appropriate conditions of the cooled-RFA were a power output of 30 W and flow rate of 30 or 40 mL.min(-1). The cooled-RFA using cold water caused a smaller, more discrete, lesion compared with that using RT water. Bronchoscopy-guided internal cooled-radiofrequency ablation was an effective, safe and feasible procedure that could become a potential therapeutic tool in managing lung pathology.

SOCS-2 interferes with myotube formation and potentiates osteoblast differentiation through upregulation of JunB in C2C12 cells

Suppressor of cytokine signaling (SOCS)-2 regulates normal postnatal growth and its deficiency in mice causes gigantism with increased bone length and proportional enlargement in skeletal muscles. Using C2C12 mesenchymal precursor cell line as a model, we investigated a possible role of SOCS-2 in the differentiation process of mesenchymal precursors. Stable transfection of SOCS-2 into C2C12 cells resulted in the acceleration of proliferation and survival, and inhibition of spontaneous myotube formation. In addition, SOCS-2 potentiated bone morphogenic protein (BMP)-induced transdifferentiation of C2C12 cells into osteoblast phenotypes. These effects of SOCS-2 on C2C12 cells differed strikingly from that of SOCS-1, another member of SOCS family, and its mechanisms were evaluated. SOCS-2 did not alter BMP-induced phosphorylation and nuclear accumulation of Smad1, nor the expression of inhibitory-Smads mRNA. However, SOCS-2 enhanced BMP-induced transcriptional activation of the Smad-responsive reporter gene, suggesting that the action of SOCS-2 is exerted at the transcriptional level. Interestingly, SOCS-2 overexpression in C2C12 cells increased the endogenous JunB protein, one of the key transcriptional factors in the control of BMP/Smad signaling responsiveness. In addition, the proteasome inhibitor enhanced JunB protein expression in C2C12 cells. Moreover, we found that SOCS-2 reduced JunB ubiquitination in COS-7 cells. Although SOCS-2 is a modulator of growth hormone (GH) signaling, the upregulation of JunB by SOCS-2 did not require GH signaling. Taken together, these results suggest that SOCS-2 positively regulates endogenous JunB protein expression in C2C12 cells through inhibition of JunB destabilization by the ubiquitin-proteasome pathway, and thereby regulates the cell fate of mesenchymal precursors.

Osteoblast differentiation is impaired in SOCS-1-deficient mice

The suppressor of cytokine signaling-1 (SOCS-1) is a cytokine-inducible intracellular molecule that inhibits excessive activation of the JAK-STAT-mediated signal cascade initiated by various stimuli. The smaller size of SOCS-1 knockout (KO) mice suggests the presence of skeletal abnormality caused by the disruption of the regulatory system in JAK-STAT signaling. In addition to macroscopic examination, peripheral quantitative computed tomography (pQCT), bone histomorphometrical analysis, and in situ hybridization were used to examine the skeletal properties of SOCS-1 KO mice. Moreover, differentiation of primary cultured osteoblasts was investigated. Distinct phosphorylation of STAT1 was detected in the SOCS-1 KO calvarial cells but was hardly detectable in wild-type (WT) mice. Undercalcified areas in the skulls and sternum, as well as comparatively thinner calcified areas of cortical bone, were found in SOCS-1 KO mice. pQCT analysis showed a marked decrease in salt content, whereas the mineralization activity of primary cultured calvarial cells strongly suggested significant impairment in osteoblasts of SOCS-1 KO mice. In situ hybridization analysis demonstrated that these mice expressed the early markers [type I collagen (COL-1) and osteonectin (ON)] and the mid-marker [osteopontin (OP)] at levels comparable with those seen in WT mice. However, a dramatic decrease was observed in the expression level of the late marker [osteocalcin (OC)] of osteoblasts. Our findings thus demonstrate that SOCS-1 regulates osteoblast differentiation in the later stage.

Effects of cooking on concentrations of polychlorinated dibenzo-p-dioxins and related compounds in fish and meat

We investigated the cooking-induced changes in concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) (dioxins) using mackerel and beef. The concentrations of dioxins (29 congeners) were determined by isomer specific analyses and were compared between uncooked and cooked samples. The cooking procedures examined in this study included grilling as a fillet, boiling as a fillet, and boiling as tsumire (small, hand-rolled balls) for mackerel and boiling as a slice, broiling as a slice, and broiling as a hamburger for beef. Three trials were carried out for each cooking method. Generally, concentrations of dioxins were reduced in every cooking trial. When nondetected congener concentrations were assumed to be half the limit of detection for mackerel, the maximum percentage reductions of total concentrations given as 2,3,7,8-tetraCDD equivalents (TEQ) were 31% in grilling as a slice, 14% in boiling as a slice, and 21% in boiling as tsumire under the conditions of this study. In contrast, for beef, the reductions were 42% in boiling as a slice, 42% in broiling as a slice, and 44% in broiling as a hamburger. These results suggest that ordinary cooking processes with heating undoubtedly reduce the dioxin content in animal products, and the reductions estimated should be considered when dioxin intake is evaluated using contamination data for individual food items.

Factors associated with granulocyte colony-stimulating factor-induced peripheral blood stem cell yield in healthy donors

BACKGROUND AND OBJECTIVES

Poor collection results are a clinical problem in granulocyte-colony stimulating factor (G-CSF)-induced peripheral blood stem cell (PBSC) collection in healthy donors. It would be beneficial to be able to predict the PBSC yield from allogeneic donors before mobilization or harvesting.

MATERIALS AND METHODS

We examined the relationship between certain donor characteristics and the effectiveness of G-CSF-induced PBSC collection in 59 healthy family donors aged 3-63 years old (median 16 years). G-CSF was administered subcutaneously at 10 microg/kg for mobilization, daily for 5 days, and PBSC harvest using a continuous blood cell separator was started on day 5 of G-CSF treatment. Total cell yields were calculated as the number per unit of processed blood (l) per unit weight of the donor (kg).

RESULTS

In a univariate analysis, the donor's age, body mass index (BMI), white blood cell (WBC) count before mobilization, and platelet count before and during mobilization were significantly correlated with the yield of mononuclear cells (MNC), CD34(+) cells and granulocyte-macrophage colony-forming units (GM-CFU). Younger age (P < 0.001), a low BMI (P = 0.002), a high WBC count before mobilization (P = 0.004), a high platelet count before (P = 0.012) and during (P < 0.05) mobilization, and a low speed of withdrawal (P = 0.019) were associated with a higher CD34(+) cell yield. No significant correlation was found for gender, the type of G-CSF, the serum level of G-CSF, the type of cell separator, or the type of blood access. A multivariate forward and backward stepwise selection regression analysis showed that the factors associated with CD34(+) cell yield were age, platelet count before and during mobilization, and circulating CD34(+) cell concentration on day 2 of G-CSF treatment.

CONCLUSION

In this small preliminary study, we found that donor age is the most important factor in predicting G-CSF-induced PBSC yields. Old age and low platelet counts before mobilization might be useful indicators for identifying poor mobilizers. Further validation of these findings in a larger number of donors are needed to establish whether these findings apply to other populations.

Determination of polybrominated diphenyl ethers and polybrominated dibenzo-p-dioxins/dibenzofurans in marine products

Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in plastics and textile coatings, and these compounds have been recognized as ubiquitous environmental contaminants. Furthermore, it is considered a serious problem that polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs), having toxicities similar to those of chlorinated dioxins, are generated by the manufacture of brominated flame retardants (BFRs) such as PBDEs, and formed by the combustion of substances containing BFRs. Several congeners of PBDD/DFs and PBDEs have been detected in the adipose tissue of the Japanese. Although food is suspected as an exposure source, little information is available regarding the levels of these brominated compounds in food, as compared with information regarding dioxin or polychlorinated biphenyls. It is necessary to investigate the levels of these brominated organic compounds in various foods and to estimate their influence in the case of human exposure. We developed an efficient method of analyzing PBDEs and PBDD/DFs contents in food samples using accelerated solvent extraction and determined the concentrations in several marine products such as raw fish, processed foods, and seaweed purchased in Japan. A recovery test (n = 5) using the method and involving dried fish showed acceptable recoveries of 57.7-78.5% (RSD 5.4-15.9%) for PBDEs and 50.0-56.4% (RSD 1.5-7.9%) for PBDD/DFs. In the analysis of marine product samples, several congeners of PBDEs were detected in raw fish, processed fish, and seaweed; the highest concentration of sigmaPBDEs was detected in yellowtail (1161 pg/g whole basis), followed by mackerel (553.5 pg/g whole basis). The most dominant congener present in these marine samples was 2,2',4,4'-tetraBDE (#47).

[Analysis of polychlorinated quaterphenyls in Yusho diagnosis]

The polychlorinated quaterphenyl (PCQ) concentrations in the blood are important discriminative parameters in Yusho patients. In this study, the analytical method of PCQ was improved, and a high speed and precision analysis could be achieved. A recovery test showed satisfactory recoveries of 99.5% (RSD4.8%, n = 5). Using this method, the authors analyzed 62 blood samples which were collected from the 2004 annual inspection for Kanemi rice oil poisoning. PCQ was detected in 20 blood samples (ranging from 0.03 to 4.15 ng/g). The average concentration was 2.07 ng/g in the pattern A (typical Yusho patients), 0.76 ng/g in the pattern B, 0.18 ng/g in the pattern BC and 0.01 ng/g in the pattern C, respectively.