MAX controls meiotic entry in sexually undifferentiated germ cells

Meiosis is a specialized type of cell division that occurs physiologically only in germ cells. We previously demonstrated that MYC-associated factor X (MAX) blocks the ectopic onset of meiosis in embryonic and germline stem cells in culture systems. Here, we investigated the Max gene's role in mouse primordial germ cells. Although Max is generally ubiquitously expressed, we revealed that sexually undifferentiated male and female germ cells had abundant MAX protein because of their higher Max gene expression than somatic cells. Moreover, our data revealed that this high MAX protein level in female germ cells declined significantly around physiological meiotic onset. Max disruption in sexually undifferentiated germ cells led to ectopic and precocious expression of meiosis-related genes, including Meiosin, the gatekeeper of meiotic onset, in both male and female germ cells. However, Max-null male and female germ cells did not complete the entire meiotic process, but stalled during its early stages and were eventually eliminated by apoptosis. Additionally, our meta-analyses identified a regulatory region that supports the high Max expression in sexually undifferentiated male and female germ cells. These results indicate the strong connection between the Max gene and physiological onset of meiosis in vivo through dynamic alteration of its expression.

Two DNA binding domains of MGA act in combination to suppress ectopic activation of meiosis-related genes in mouse embryonic stem cells

Although the physiological meaning of the high potential of mouse embryonic stem cells (ESCs) for meiotic entry is not understood, a rigid safeguarding system is required to prevent ectopic onset of meiosis. PRC1.6, a non-canonical PRC1, is known for its suppression of precocious and ectopic meiotic onset in germ cells and ESCs, respectively. MGA, a scaffolding component of PRC1.6, bears two distinct DNA-binding domains termed bHLHZ and T-box. However, it is unclear how this feature contributes to the functions of PRC1.6. Here, we demonstrated that both domains repress distinct sets of genes in murine ESCs, but substantial numbers of meiosis-related genes are included in both gene sets. In addition, our data demonstrated that bHLHZ is crucially involved in repressing the expression of Meiosin, which plays essential roles in meiotic entry with Stra8, revealing at least part of the molecular mechanisms that link negative and positive regulation of meiotic onset.

Identification of germ cell-specific Mga variant mRNA that promotes meiosis via impediment of a non-canonical PRC1

A non-canonical PRC1 (PRC1.6) prevents precocious meiotic onset. Germ cells alleviate its negative effect by reducing their amount of MAX, a component of PRC1.6, as a prerequisite for their bona fide meiosis. Here, we found that germ cells produced Mga variant mRNA bearing a premature termination codon (PTC) during meiosis as an additional mechanism to impede the function of PRC1.6. The variant mRNA encodes an anomalous MGA protein that lacks the bHLHZ domain and thus functions as a dominant negative regulator of PRC1.6. Notwithstanding the presence of PTC, the Mga variant mRNA are rather stably present in spermatocytes and spermatids due to their intrinsic inefficient background of nonsense-mediated mRNA decay. Thus, our data indicate that meiosis is controlled in a multi-layered manner in which both MAX and MGA, which constitute the core of PRC1.6, are at least used as targets to deteriorate the integrity of the complex to ensure progression of meiosis.

Renal arteriolar hyalinosis, not intimal thickening in large arteries, is associated with cardiovascular events in people with biopsy-proven diabetic nephropathy

AIMS

Diabetic nephropathy, a pathologically diagnosed microvascular complication of diabetes, is a strong risk factor for cardiovascular events, which mainly involve arteries larger than those affected in diabetic nephropathy. However, the association between diabetic nephropathy pathological findings and cardiovascular events has not been well studied. We aimed to investigate whether the pathological findings in diabetic nephropathy are closely associated with cardiovascular event development.

METHODS

This retrospective cohort study analysed 377 people with type 2 diabetes and biopsy-proven diabetic nephropathy, with a median follow-up of 5.9 years (interquartile range 2.0 to 13.5). We investigated how cardiovascular events were impacted by two vascular diabetic nephropathy lesions, namely arteriolar hyalinosis and arterial intimal thickening, and by glomerular and interstitial lesions.

RESULTS

Of the 377 people with diabetic nephropathy, 331 (88%) and 295 (78%) had arteriolar hyalinosis and arterial intimal thickening, respectively. During the entire follow-up period, those with arteriolar hyalinosis had higher cardiovascular event rates in the crude Kaplan-Meier analysis than those without these lesions (P = 0.005, log-rank test). When fully adjusted for clinically relevant confounders, arteriolar hyalinosis independently predicted cardiovascular events [hazard ratio (HR) 1.99; 95% confidence interval (CI) 1.12, 3.86], but we did not find any relationship between arterial intimal thickening and cardiovascular events (HR 0.89; 95% CI 0.60, 1.37). Additionally, neither glomerular nor interstitial lesions were independently associated with cardiovascular events in the fully adjusted model.

CONCLUSIONS

Arteriolar hyalinosis, but not intimal thickening of large arteries, was strongly associated with cardiovascular events in people with diabetic nephropathy.

Abstract P3-08-11: The prognostic impact of retinoic acid-induced 2 (RAI2) expression in ERα-positive breast cancer patients

Background: Breast cancer cells disseminate to the bone marrow and form bone metastases in a large majority of late-stage patients. Retinoic Acid-Induced 2 (RAI2) was reported as a putative suppressor of early hematogenous dissemination of tumor cells to the bone marrow in breast cancer, particularly in estrogen receptor α (ERα)-positive breast cancer. Here, we investigated mRNA expression of RAI-2 in breast cancer patients during long-term follow-up.

Materials and methods: A total of 451 invasive breast cancer tissues was available for analysis of RAI2 mRNA using a TaqMan PCR system. We also sought correlations between clinicopathological factors and levels of RAI2 expression in these samples. The expression of markers associated with tumor-initiating capacity, such as SNAI1, SNAI2 and VIM was also analyzed. The median follow-up period was 9.0 years. Survival curves were analyzed using the Kaplan-Meier method. Cox proportional hazards regression analysis was used for univariate and multivariate analyses of prognostic values.

Results: We found positive correlations between low expression of RAI2 mRNA and shorter disease-free survival and overall survival in breast cancer patients (P=0.003, P<0.0001, respectively), which was limited to ERα-positive patients (P=0.04, P=0.0009, respectively), and not seen in ERα-negative patients (P=0.52, P=0.27, respectively). Low RAI2 mRNA levels were positively correlated with high grade, ERα-negativity and PgR negativity. Multivariate analysis indicated that low level RAI2 mRNA expression was an independent factor for survival both overall in breast cancer and in ERα-positive breast cancer patients

Multivariate analysis (ERα-positive breast cancer patients)  OS  Multivariate patientsp valueHR(95%CI)Tumor size≤2cm1390.83691 (Reference) >2cm207 1.08(0.54-2.28)Node statusNegative176<0.00011 (Reference) Positive144 4.72(2.33-10.34)Grade11240.95921 (Reference) 2•3218 0.98(0.50-2.14)RAI2 mRNA expressionhigh140<0.00011 (Reference) middle•low206 4.79(2.14-12.78)

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Conclusion:We show that low expression of RAI2 is an independent factor predictive of a poor prognosis in ERα-positive breast cancer patients. RAI2 could be a promising candidate biomarker and therapeutic target in ERα-positive breast cancer to prevent dissemination to the bone marrow.

Citation Format: Nishikawa S, Kondo N, Endo Y, Hato Y, Hisada T, Nishimoto M, Dong Y, Okuda K, Kato H, Takahashi S, Nakanishi R, Toyama T. The prognostic impact of retinoic acid-induced 2 (RAI2) expression in ERα-positive breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-08-11.

Link between embryonic stem cell pluripotency and homologous allelic pairing of Oct4 loci

The Oct4 gene is a master regulator of the pluripotent properties of embryonic stem cells (ESCs). Recently, Oct4 loci were shown to frequently localize in close proximity to one another during the early stage of cellular differentiation, implicating this event as an important prerequisite step for ESCs to exert their full differentiation potential. Although the differentiation capacity of embryonal carcinoma cells (ECCs), such as F9 and P19 ECC lines, is severely restricted compared with ESCs, ECCs bear a highly similar expression profile to that of ESCs including expression of Oct4 and other pluripotency marker genes. Therefore, we examined whether allelic pairing of Oct4 loci also occurs during differentiation of F9 and P19 ECCs. Our data clearly demonstrate that this event is only observed within ESCs, but not ECCs, subjected to induction of differentiation, indicating transient allelic pairing of Oct4 loci as a specific feature of pluripotent ESCs. Moreover, our data revealed that this pairing did not occur broadly across chromosome 17, which carries the Oct4 gene, but occurred locally between Oct4 loci, suggesting that Oct4 loci somehow exert a driving force for their allelic pairing.

Abstract P6-07-34: The prognostic impact of inositol polyphosphate 5-phosphatase PIPP (INPP5J) expression in breast cancer tissue

Background : Inositol polyphosphate 5-phosphatase PIPP (INPP5J) has been identified as a suppressor of oncogenic PI3K/Akt signaling in breast cancer.INPP5J depletion increases transformation and accelerates oncogene-driven tumor growth in vivo, while paradoxically reducing cell migration, invasion, and metastasis. Therefore, we hypothesized that INPP5J gene expression in human breast cancer tissues would be prognostic in early breast cancer patients over long-term follow-up.

Methods: A total of 478 breast cancer tissue samples collected between 2003 and 2008 was available for analysis. We measured INNPP5J mRNA using a TaqMan gene expression assay. PIK3CA mutation status was evaluated using a TaqMan mutation detection assay. We then investigated the correlations of clinicopathological factors and prognosis with levels of INPP5J mRNA and the PIK3CA mutation status.

Results: INPP5J mRNA was expressed at a low level in 30.1% (144/478) and at a medium to high level in the remaining breast cancer samples. Low INPP5J mRNA correlated with larger tumor (p=0.015), high grade (p<0.0001) and, ER-negativity (p<0.0001). PIK3CA mutations were detected in 46% (63/138) of patients analyzed. We found that disease-free survival (DFS) was significantly worse in patients with low levels of INPP5J (p=0.008). Although DFS and INPP5J levels tended to be associated in estrogen receptor (ER)-positive patients (p=0.052), DFS was significantly worse in patients with wild-type PIK3CA and low INPP5J mRNA expression (p=0.008).

Conclusion: We shows that the level of INPP5J mRNA expression is prognostics in breast cancer patients and that its prognostic impact is affected by PIK3CA mutation status.

Citation Format: Kondo N, Kim T-S, Wanifuchi Y, Hato Y, Hisada T, Nishimoto M, Nishikawa S, Toyama T. The prognostic impact of inositol polyphosphate 5-phosphatase PIPP (INPP5J) expression in breast cancer tissue [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-34.

Abstract P2-03-07: Exome sequencing of human breast cancer tissues resistant to taxanes

Background: Although taxanes are a mainstay of breast cancer treatment, some cases are resistant to these drugs. This is a crucial issue in breast cancer therapy. In the emerging era of next-generation sequencing, it is possible to obtain extensive genomic information on individual tumors in a very short time. Using this technology, it was reported that specific mutations might affect therapeutic efficacy and induce resistance to specific treatment.

Objective: The aim of this study was to investigate the mechanisms of taxane resistance using whole exon sequencing and expression analyses in human breast cancer tissues.

Materials and Methods: We selected six breast cancer patients whose tumors responded well to anthracycline treatment but suffered disease progression on taxane treatment. We then performed whole exon sequencing on these samples using HiSeq (Illumia). In this way, we identified somatic mutations of candidate genes considered to be instrumental for mediating resistance to taxanes. Next, we performed mRNA expression analyses of these candidate genes in a further 122 breast cancers treated with taxanes at our institute. Finally, we correlated mRNA expression levels of these genes with clinicopathological factors and prognosis.

Results: We identified 9 mutations common to all 6 patients analyzed in this study, and a further 16 mutations shared by 5 of them. Kaplan-Meier analyses showed that high level mRNA expression of 3 of these 25 genes was significantly associated with poorer disease-free survival. Moreover, high level mRNA expression of one of these three genes was significantly associated with worse overall survival. However, there were no significant correlations between expression levels of these three genes and any clinicopathologeical features.

Conclusion: Using next-generation sequencing, we have identified three candidate genes involved in resistance to taxane treatment in breast cancer. We are now analyzing the functional attributes of these three genes.

Citation Format: Endo Y, Dong Y, Kondo N, Hato Y, Hisada T, Nishimoto M, Nishikawa S, Takahashi S, Toyama T. Exome sequencing of human breast cancer tissues resistant to taxanes [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-03-07.

Loss of MAX results in meiotic entry in mouse embryonic and germline stem cells

Meiosis is a unique process that allows the generation of reproductive cells. It remains largely unknown how meiosis is initiated in germ cells and why non-germline cells do not undergo meiosis. We previously demonstrated that knockdown of Max expression, a gene encoding a partner of MYC family proteins, strongly activates expression of germ cell-related genes in ESCs. Here we find that complete ablation of Max expression in ESCs results in profound cytological changes reminiscent of cells undergoing meiotic cell division. Furthermore, our analyses uncovers that Max expression is transiently attenuated in germ cells undergoing meiosis in vivo and its forced reduction induces meiosis-like cytological changes in cultured germline stem cells. Mechanistically, Max depletion alterations are, in part, due to impairment of the function of an atypical PRC1 complex (PRC1.6), in which MAX is one of the components. Our data highlight MAX as a new regulator of meiotic onset.

The mechanisms that trigger meiosis in germ cells and halt this process in non-germline cells are unclear. Here, the authors show that knockout of Max in embryonic stem cells results in meiotic onset in a mechanism that involves the PRC1 complex.

Forced expression of Nanog or Esrrb preserves the ESC status in the absence of nucleostemin expression

Nucleostemin (NS) is a nucleolar GTP-binding protein that is involved in a plethora of functions including ribosomal biogenesis and maintenance of telomere integrity. In addition to its expression in cancerous cells, the NS gene is expressed in stem cells including embryonic stem cells (ESCs). Previous knockdown and knockout studies have demonstrated that NS is important to preserve the self-renewality and high expression levels of pluripotency marker genes in ESCs. Here, we found that forced expression of Nanog or Esrrb, but not other pluripotency factors, resulted in the dispensability of NS expression in ESCs. However, the detrimental phenotypes of ESCs associated with ablation of NS expression were not mitigated by forced expression of Rad51 or a nucleolar localization-defective NS mutant that counteracts the damage associated with loss of NS expression in other NS-expressing cells such as neural stem/progenitor cells. Thus, our results indicate that NS participates in preservation of the viability and integrity of ESCs, which is distinct from that in other NS-expressing cells. Stem Cells2015;33:1089–1101

Effectiveness of antibacterial prophylaxis with non-absorbable polymyxin B compared to levofloxacin after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Fluoroquinolones are widely used for antibacterial prophylaxis during neutropenia following hematopoietic stem cell transplantation (HSCT). Nevertheless, data are inadequate as to whether fluoroquinolones decrease mortality rate compared with other antibiotics.

METHODS

We retrospectively compared the efficacy of antibacterial prophylaxis using non-absorbable polymyxin B (PB) (n = 106) or systemic levofloxacin (LVFX) (n = 140) after allogeneic SCT at our institute between 2004 and 2013.

RESULTS

No significant difference was observed between the 2 groups in the cumulative incidences of failure of prophylaxis (P = 0.21), clinically documented infections (P = 0.70), or non-relapse mortality within the first 100 days after transplantation (P = 0.42). With bacteremia, the rate of resistance to LVFX was 82% in the PB group and 100% in the LVFX group (P = 0.41). Also, no significant difference was found in overall survival between the 2 groups (P = 0.78).

CONCLUSION

Our results indicate no difference in the effectiveness of antibacterial prophylaxis between systemic antibiotic LVFX and non-absorbable antibiotic PB.

Viper bite during pregnancy: case report

Viper bites in pregnant women have rarely been reported thus far. Moreover, there is no consensus regarding the treatment of such cases. In this paper, the authors report the successful treatment of viper bite during pregnancy without using antivenom.

Striking similarity in the gene expression levels of individual Myc module members among ESCs, EpiSCs, and partial iPSCs

Predominant transcriptional subnetworks called Core, Myc, and PRC modules have been shown to participate in preservation of the pluripotency and self-renewality of embryonic stem cells (ESCs). Epiblast stem cells (EpiSCs) are another cell type that possesses pluripotency and self-renewality. However, the roles of these modules in EpiSCs have not been systematically examined to date. Here, we compared the average expression levels of Core, Myc, and PRC module genes between ESCs and EpiSCs. EpiSCs showed substantially higher and lower expression levels of PRC and Core module genes, respectively, compared with those in ESCs, while Myc module members showed almost equivalent levels of average gene expression. Subsequent analyses revealed that the similarity in gene expression levels of the Myc module between these two cell types was not just overall, but striking similarities were evident even when comparing the expression of individual genes. We also observed equivalent levels of similarity in the expression of individual Myc module genes between induced pluripotent stem cells (iPSCs) and partial iPSCs that are an unwanted byproduct generated during iPSC induction. Moreover, our data demonstrate that partial iPSCs depend on a high level of c-Myc expression for their self-renewal properties.

Identification of Ccr4-not complex components as regulators of transition from partial to genuine induced pluripotent stem cells

Somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) by defined factors. However, substantial cell numbers subjected to iPSC induction stray from the main reprogramming route and are immortalized as partial iPSCs. These partial iPSCs can become genuine iPSCs by exposure to the ground state condition. However, such conversion is only possible for mouse partial iPSCs, and it is not applicable to human cells. Moreover, the molecular basis of this conversion is completely unknown. Therefore, we performed genome-wide screening with a piggyBac vector to identify genes involved in conversion from partial to genuine iPSCs. This screening led to identification of Cnot2, one of the core components of the Ccr4-Not complex. Subsequent analyses revealed that other core components, Cnot1 and Cnot3, also contributed to the conversion. Thus, our data have uncovered a novel role of core components of the Ccr4-Not complex as regulators of transition from partial to genuine iPSCs.

In vivo function and evolution of the eutherian-specific pluripotency marker UTF1

Embryogenesis in placental mammals is sustained by exquisite interplay between the embryo proper and placenta. UTF1 is a developmentally regulated gene expressed in both cell lineages. Here, we analyzed the consequence of loss of the UTF1 gene during mouse development. We found that homozygous UTF1 mutant newborn mice were significantly smaller than wild-type or heterozygous mutant mice, suggesting that placental insufficiency caused by the loss of UTF1 expression in extra-embryonic ectodermal cells at least in part contributed to this phenotype. We also found that the effects of loss of UTF1 expression in embryonic stem cells on their pluripotency were very subtle. Genome structure and sequence comparisons revealed that the UTF1 gene exists only in placental mammals. Our analyses of a family of genes with homology to UTF1 revealed a possible mechanism by which placental mammals have evolved the UTF1 genes.

Sirt1, p53, and p38(MAPK) are crucial regulators of detrimental phenotypes of embryonic stem cells with Max expression ablation

c-Myc participates in diverse cellular processes including cell cycle control, tumorigenic transformation, and reprogramming of somatic cells to induced pluripotent cells. c-Myc is also an important regulator of self-renewal and pluripotency of embryonic stem cells (ESCs). We recently demonstrated that loss of the Max gene, encoding the best characterized partner for all Myc family proteins, causes loss of the pluripotent state and extensive cell death in ESCs strictly in this order. However, the mechanisms and molecules that are responsible for these phenotypes remain largely obscure. Here, we show that Sirt1, p53, and p38(MAPK) are crucially involved in the detrimental phenotype of Max-null ESCs. Moreover, our analyses revealed that these proteins are involved at varying levels to one another in the hierarchy of the pathway leading to cell death in Max-null ESCs.

Risk factors affecting cardiac left-ventricular hypertrophy and systolic and diastolic function in the chronic phase of allogeneic hematopoietic cell transplantation

Chronic impairment of cardiac function can be an important health risk and impair the quality of life, and may even be life-threatening for long-term survivors of allogeneic hematopoietic cell transplantation (HCT). However, risk factors for and/or the underlying mechanism of cardiac dysfunction in the chronic phase of HCT are still not fully understood. We retrospectively investigated factors affecting cardiac function and left-ventricular hypertrophy (LVH) in the chronic phase of HCT. Sixty-three recipients who survived for >1 year after receiving HCT were evaluated using echocardiography. Based on simple linear regression models, high-dose TBI-based conditioning was significantly associated with a decrease in left-ventricular ejection fraction and the early peak flow velocity/atrial peak flow velocity ratio, following HCT (coefficient=-5.550, P=0.02 and coefficient=-0.268, P=0.02, respectively). These associations remained significant with the use of multiple linear regression models. Additionally, the serum ferritin (s-ferritin) level before HCT was found to be a significant risk factor for LVH on multivariable logistic analysis (P=0.03). In conclusion, our study demonstrated that a myeloablative regimen, especially one that involved high-dose TBI, impaired cardiac function, and that a high s-ferritin level might be associated with the development of LVH in the chronic phase of HCT.

Immunoglobulin prophylaxis against cytomegalovirus infection in patients at high risk of infection following allogeneic hematopoietic cell transplantation

Reports on the efficacy of intravenous immunoglobulin (IVIG) prophylaxis against cytomegalovirus (CMV) infection after allogeneic hematopoietic cell transplantation (HCT) have often sparked controversy. In addition, we are not aware of any study that has examined whether prophylaxis with IVIG affects the incidence of CMV infection in high-risk patients--those who are elderly or have received human leukocyte antigen (HLA) mismatched HCT. In the present open-label, phase II study, we addressed this question. We enrolled 106 patients in the study. The cumulative incidences of CMV infection at 100 days after HCT were similar in the intervention and the control groups (68% and 64%, P=.89; 89% and 87%, P=.79, respectively, for patients 55 years or older and those who received HLA-mismatched HCT). In those who received HLA-mismatched HCT, 1-year overall survival after HCT was 46% in the intervention group and 40% in the control group (P=.31); for age≥55 years, the corresponding values were 46% and 40% (P=.27). Our data showed that prophylaxis with regular polyvalent IVIG did not affect the incidence of CMV infections or survival among older patients or those who receive HLA-mismatched HCT.

Indefinite self-renewal of ESCs through Myc/Max transcriptional complex-independent mechanisms

Embryonic stem cells (ESCs) can self-renew indefinitely under the governance of ESC-specific transcriptional circuitries in which each transcriptional factor regulates distinct or overlapping sets of genes with other factors. c-Myc is a key player that is crucially involved in maintaining the undifferentiated state and the self-renewal of ESCs. However, the mechanism by which c-Myc helps preserve the ESC status is still poorly understood. Here we addressed this question by performing loss-of-function studies with the Max gene, which encodes the best-characterized partner protein for all Myc family proteins. Although Myc/Max complexes are widely regarded as crucial regulators of the ESC status, our data revealed that ESCs do not absolutely require these complexes in certain contexts and that this requirement is restricted to empirical ESC culture conditions without a MAPK inhibitor.

Consequence of the loss of Sox2 in the developing brain of the mouse

The transcription factor Sox2 is expressed at high levels in neural stem and progenitor cells. Here, we inactivated Sox2 specifically in the developing brain by using Cre-loxP system. Although mutant animals did not survive after birth, analysis of late gestation embryos revealed that loss of Sox2 causes enlargement of the lateral ventricles and a decrease in the number of neurosphere-forming cells. However, although their neurogenic potential is attenuated, Sox2-deficient neural stem cells retain their multipotency and self-renewal capacity. We found that expression level of Sox3 is elevated in Sox2 null developing brain, probably mitigating the effects of loss of Sox2.

The normal neonatal brain: MR imaging, diffusion tensor imaging, and 3D MR spectroscopy in healthy term neonates

BACKGROUND AND PURPOSE

There is a lack of normative diffusion tensor imaging (DTI) and 3D MR spectroscopy (MRS) data in the early neonatal period. We report quantitative values from a cohort of healthy term neonates to serve as baseline data for studies assessing brain development and injury.

MATERIALS AND METHODS

Sixteen healthy term neonates (median age, 7 days) were studied with spin-echo T1- and T2-weighted MR imaging, DTI, and 3D point-resolved spectroscopy sequence (PRESS) MRS without sedation on a 1.5 T scanner. Average diffusivity (D(av)), fractional anisotropy (FA), eigenvalues (EV), and metabolite ratios (N-acetylaspartate [NAA]/choline, lactate/choline) were calculated by automated processing in 7 brain regions. Neurodevelopment was assessed by blinded and validated neuromotor examinations and the Bayley II test at 3 and 14 months.

RESULTS

Two neonates were excluded from the cohort: one had brain injury on T2-weighted imaging, and the other, who had normal MR imaging, showed mildly delayed cognition at 14 months. The mean DTI values of the remaining 14 neonates were between these ranges: D(av)=0.98-1.48 10(-3) mm(2)/s, FA=0.14-0.30, EV1=1.21-1.88, EV2=0.95-1.46, and EV3=0.77-1.24 (all x 10(-3) mm(2)/s). The NAA/choline ratio ranged between 0.58 and 0.73, and minimal lactate/choline (<0.15) could be detected in each neonate. All neonates exhibited clinically normal neuromotor status.

CONCLUSIONS

Our study demonstrates the feasibility of obtaining high-quality quantifiable MR data in nonsedated healthy term neonates that can be used to study normal early brain development and as control data in studies of perinatal brain injury.

Putative "stemness" gene jam-B is not required for maintenance of stem cell state in embryonic, neural, or hematopoietic stem cells

Many genes have been identified that are specifically expressed in multiple types of stem cells in their undifferentiated state. It is generally assumed that at least some of these putative "stemness" genes are involved in maintaining properties that are common to all stem cells. We compared gene expression profiles between undifferentiated and differentiated embryonic stem cells (ESCs) using DNA microarrays. We identified several genes with much greater signal in undifferentiated ESCs than in their differentiated derivatives, among them the putative stemness gene encoding junctional adhesion molecule B (Jam-B gene). However, in spite of the specific expression in undifferentiated ESCs, Jam-B mutant ESCs had normal morphology and pluripotency. Furthermore, Jam-B homozygous mutant mice are fertile and have no overt developmental defects. Moreover, we found that neural and hematopoietic stem cells recovered from Jam-B mutant mice are not impaired in their ability to self-renew and differentiate. These results demonstrate that Jam-B is dispensable for normal mouse development and stem cell identity in embryonic, neural, and hematopoietic stem cells.

Stent-supported angioplasty of a residual coronary artery dissection following replacement of the ascending aorta for acute type A aortic dissection. A report of a successful case

A 54-year-old-man suddenly experienced severe back pain while eating. On admission to our hospital, contrast-enhanced computed tomography revealed an acute type A aortic dissection, and emergency surgical repair was performed the same day. Through median sternotomy, graft replacement of the ascending aorta, including removal of the site of the intimal tear, was carried out under deep hypothermia and retrograde cerebral perfusion. Although the postoperative course was satisfactory, the patient suddenly complained of sever chest pain on postoperative day 23; the ECG trace showed anomalous alterations. Emergency coronary angiography revealed the presence of a wide coronary artery dissection from the entry of the left anterior descending aorta (LAD) to the re-entry of the left circumflex artery (LCX). Multiple stents were implanted in the LAD and LCX. After stenting, the chest symptoms remitted and the ECG trace was normal. The patient was discharged from our hospital on postoperative day 42.

The Sox2 regulatory region 2 functions as a neural stem cell-specific enhancer in the telencephalon

Sox2 is expressed at high levels in neuroepithelial stem cells and persists in neural stem/progenitor cells throughout adulthood. We showed previously that the Sox2 regulatory region 2 (SRR2) drives strong expression in these cells. Here we generated transgenic mouse strains with the beta-geo reporter gene under the control of the SRR2 in order to examine the spatiotemporal function of this regulatory region. We show that the SRR2 functions specifically in neural stem/progenitor cells. However, unlike Nestin 2nd intronic enhancer, the SRR2 shows strong regional specificity functioning only in restricted areas of the telencephalon but not in any other portions of the central nervous system such as the spinal cord. We also show by in vitro clonogenic assay that at least some of these SRR2-functioning cells possess the hallmark properties of neural stem cells. In adult brains, we could detect strong beta-geo expression in the subventricular zone of the lateral ventricle and along the rostral migrating stream where actively dividing cells reside. Chromatin immunoprecipitation assays reveal interactions of POU and Sox factors with SRR2 in neural stem/progenitor cells. Our data also suggest that the specific recruitment of these proteins to the SRR2 in the telencephalon defines the spatiotemporal activity of the enhancer in the developing nervous system.

Upflow anaerobic sludge blanket (UASB) treatment of supernatant of cow manure by thermal pre-treatment

Upflow anaerobic sludge blanket (UASB) methane fermentation treatment of cow manure that was subjected to screw pressing, thermal treatment and subsequent solid-liquid separation was studied. Conducting batch scale tests at temperatures between 140 and 180 degrees C, the optimal temperature for sludge settling and the color suppression was found to be between 160-170 degrees C. UASB treatment was carried out with a supernatant obtained from the thermal treatment at the optimal conditions (170 degrees C for 30 minutes) and polymer-dosed solid-liquid separation. In the UASB treatment with a COD(Cr) loading of 11.7 kg/m3/d and water temperature of 32.2 degrees C, the COD(Cr) level dropped from 16,360 mg/L in raw water to 3,940 mg/L in treated water (COD(Cr), removal rate of 75.9%), and the methane production rate per COD(Cr) was 0.187 Nm3/kg. Using wastewater thermal-treated at the optimal conditions, also a methane fermentation treatment with a continuously stirred tank reactor (CSTR) was conducted (COD(Cr) in raw water: 38,000 mg/L, hydraulic retention time (HRT): 20 days, 35 degrees C). At the COD(Cr) loading of 1.9 kg/m3/d, the methane production rate per COD(Cr), was 0.153 Nm3/kg. This result shows that UASB treatment using thermal pre-treatment provides a COD(Cr), loading of four times or more and a methane production rate of 1.3 times higher than the CSTR treatment.

Oct-3/4 maintains the proliferative embryonic stem cell state via specific binding to a variant octamer sequence in the regulatory region of the UTF1 locus

The POU transcription factor Oct-3/4 has been shown to be critical for maintaining embryonic stem (ES) cell character. However, the molecular mechanisms underlying its function remain elusive. We have previously shown that among the POU transcription factor family of proteins, Oct-3/4 alone is able to bind to the regulatory region of the UTF1 gene bearing a variant octamer sequence together with Sox-2. Here, we demonstrate using Oct-3/4-Oct-6 chimeras that there is a precise correlation between the ability of proteins to form a complex on the UTF1 enhancer with Sox-2 and the ability to maintain the stem cell state in ES cells. Different chimeric proteins show differential abilities to form a Sox-2-containing complex on the UTF1 regulatory region, with a decrease in efficiency of the complex formation accompanied by a decrease in the level of UTF1 expression and the rate of cell proliferation. Overexpression of UTF1 in these slow-growing cells was able to restore their proliferation rate to wild-type levels. Moreover, UTF1 was also observed to have an effect on teratoma formation. These results suggest a molecular pathway by which Oct-3/4 induces rapid proliferation and tumorigenic properties of ES cells through activation of the UTF1 gene.

Identification of an Enhancer That Controls Up-regulation of Fibronectin during Differentiation of Embryonic Stem Cells into Extraembryonic Endoderm

The extraembryonic endoderm is derived from inner cell mass cells of the blastocyst during early mouse embryogenesis. Formation of the extraembryonic endoderm, which later contributes to the yolk sac, appears to be a prerequisite for subsequent differentiation of the inner cell mass. While embryonic stem cells can be induced to differentiate into extraembryonic endoderm cells in vitro, the molecular mechanisms underlying this process are poorly understood. We used a promoter trap approach to search for genes that are expressed in embryonic stem cells and are highly up-regulated during differentiation to the extraembryonic endoderm fate. We showed that fibronectin fits this expression profile. Moreover we identified an enhancer in the 12th intron of the fibronectin locus that recapitulated the endogenous pattern of fibronectin expression. This enhancer carries Sox protein-binding sequences, and our analysis demonstrated that Sox7 and Sox17, which are highly expressed in the extraembryonic endoderm, were involved in enhancer activity.

[Management of remaining coronary artery dissection after the replacement of the ascending aorta in acute type A aortic dissection]

The authors report a case study of a 54-year-old male admitted to our hospital with severe chest pain and ST depression in II, III and aVf lead on the electrocardiogram. The chest X-ray showed an enlarged superior mediastinum. An enhanced computed tomography (CT) was performed and confirmed the diagnosis of acute type A aortic dissection. The patient underwent emergency surgical repair with the replacement of the ascending aorta. The patient recovered without complication until the fifteenth postoperative day, when another severe chest pain appeared. Emergency coronary angiography revealed a remaining dissection in both the left anterior descending artery (LAD) and the left circumflex artery (LCx). Implantation of Elite stents to the LAD and the LCx was performed. The patient recovered uneventfully after this operation. Remaining coronary artery dissection after the replacement of the ascending aorta is very rare. In this case coronary intervention with Elite stents was effective.

The Sox-2 regulatory regions display their activities in two distinct types of multipotent stem cells

The Sox-2 gene is expressed in embryonic stem (ES) cells and neural stem cells. Two transcription enhancer regions, Sox-2 regulatory region 1 (SRR1) and SRR2, were described previously based on their activities in ES cells. Here, we demonstrate that these regulatory regions also exert their activities in neural stem cells. Moreover, our data reveal that, as in ES cells, both SRR1 and SRR2 show their activities rather specifically in multipotent neural stem or progenitor cells but cease to function in differentiated cells, such as postmitotic neurons. Systematic deletion and mutation analyses showed that the same or at least overlapping DNA elements of SRR2 are involved in its activity in both ES and neural stem or progenitor cells. Thus, SRR2 is the first example of an enhancer in which a single regulatory core sequence is involved in multipotent-state-specific expression in two different stem cells, i.e., ES and neural stem cells.