[The effect of the histoculture drug response assay (HDRA) based perioperative chemotherapy for non-small cell lung cancer]

In this study we analyze the usefulness of the histoculture drug response assay (HDRA) based perioperative chemotherapy for non-small cell lung cancer. From 2001 to 2006, we examined the chemosensitivity of 70 lung cancer tissues to cisplatin (CDDP), carboplatin (CBDCA), paclitaxel, docetaxel, gemcitabine and irinotecan. In 16 patients with stage III lung cancer who treated induction therapy, the response rate was 100% of 5 patients treated chemotherapy using 2 HDRA-positive drugs, 50% of 8 patient treeated using 1 positive drugs and 0% of 3 patients treated using negative drugs, respectively. The 3-year survival rate of the 5 patients treated using 2 positive drugs was better than that of 11 patient treated using 1 or non positive drugs (p = 0.07). In 39 patients with stage III lung cancer who treated adjuvant chemotherapy, the survival rate of the 14 patients treated chemotherapy using 2 positive drugs was significantly better than that of 25 patients treated using 1 or non positive drugs (p = 0.03). Therefore, HDRA may useful to the improvement of the response to chemotherapy and survival.

Abortion in a thoroughbred mare associated with an infection with avirulent Rhodococcus equi

An eight-year-old thoroughbred mare with no previous history of illness aborted a fetus at 196 days of gestation, and its internal tissues were examined immunohistologically and bacteriologically. The placenta was not examined, but specimens of the intrauterine fluids and the dam's faeces were collected four days after the abortion and examined bacteriologically. No significant histological lesions were found in the fetus but the amnion and the umbilical cord were oedematous and had petechial haemorrhages. Rhodococcus equi was isolated in pure culture from the lung, heart and stomach contents of the fetus and from an intrauterine specimen and faeces of the dam. The anti-R equi antibody titre of the mare was high after the abortion. The diagnosis was confirmed in the lung of the fetus by immunohistochemical staining with R equi-specific antibodies. Isolates from the fetus and mare were identified as avirulent R equi by pcr and the mouse pathogenicity test. The avirulent isolates were characterised by pulsed-field gel electrophoresis, which yielded only one VspI profile in all the isolates from the fetus and its dam.

Regulation of mesodermal differentiation of mouse embryonic stem cells by basement membranes

Basement membranes (BMs) have been implicated in cell fate determination during development. Embryoid bodies (EBs) derived from mouse embryonic stem cells deficient in the laminin gamma1 chain are incapable of depositing a BM, resulting in failure of primitive ectoderm epithelialization. To elucidate the mechanisms involved in this phenomenon, we compared the gene expression profiles of EBs with or without a BM to identify the genes showing BM-dependent expression. We found that the expressions of marker genes for the epithelial-mesenchymal transition (EMT), including the transcription factor Snai2, were up-regulated in LAMC1(-/-) EBs, whereas restoration of a BM to LAMC1(-/-) EBs suppressed the up-regulation of these genes. Overexpression of Snai2 induced the EMT in control EBs by molecular and morphological criteria, suggesting that suppression of the EMT regulatory genes is involved in BM-dependent epithelialization of primitive ectoderm. Despite the failure of primitive ectoderm epithelialization in BM-deficient EBs, mesodermal differentiation was not compromised, but rather accelerated. Furthermore, at later stages of control EB differentiation, the BM was disrupted at the gastrulation site where mesodermal markers were strongly expressed only in cells that had lost contact with the BM. Taken together, these results indicate that the BM prevents the EMT and precocious differentiation of primitive ectoderm toward mesoderm in EBs, implying that BMs are important for the control of mammalian gastrulation.

Efficient derivation of embryonic stem cells by inhibition of glycogen synthase kinase-3

Embryonic stem (ES) cells are derived from the inner cell mass (ICM) of blastocysts. The use of ES cells as a source of differentiated cells holds great promise for cell transplantation therapy. The efficiency of ES cell derivation is affected by genetic variation in mice; that is, some mouse strains, such as C57BL/6, are amenable to ES cell derivation, whereas others, such as BALB/c, are refractory. Developing an efficient method to establish ES cells from strains of various genetic backgrounds should be valuable for derivation of ES cells in various mammalian species, including human. Although it is well-established that various signaling pathways, including phosphoinositide 3-kinase (PI3K)/Akt and Wnt/beta-catenin, regulate the maintenance of ES cell pluripotency, little is known about the signaling pathways involved in the derivation of ES cells from ICMs. In this study, we demonstrated that inhibition of glycogen synthase kinase-3 (GSK-3), one of the crucial molecules in the regulation of the Wnt/beta-catenin, Hedgehog, and Notch signaling pathways, dramatically augmented ES cell derivation from both C57BL/6 and BALB/c mouse strains. In contrast, Akt signaling activation enhanced the growth of ICM but did not increase the efficiency of ES cell derivation. Our study establishes an efficient means for ES cell derivation by pharmacological inhibition of GSK-3.

Disruption of the mouse protein Ser/Thr phosphatase 2Cβ gene leads to early pre-implantation lethality

Protein phosphatase 2Cbeta (PP2Cbeta) is a member of a family of protein Ser/Thr phosphatases (PP2C) that is composed of at least twelve different gene products. Recent studies have revealed that PP2Cbeta mRNA accumulates in mature sperm, unfertilized metaphase II-arrested oocytes and zygotes, but that the mRNA level then decreases sharply between the early two-cell and eight-cell stages, remaining at low levels during the 16-cell to blastocyst stages of mice. These observations raised the possibility that PP2Cbeta plays a crucial role during gametogenesis, fertilization, and/or early stages of embryonic development. In this study, we employed a gene knockout technique in mice to test this possibility. We found that PP2Cbeta(Delta/wt) mice generate normal mature gametes. However, PP2Cbeta(Delta/Delta) embryos die between the two-cell and eight-cell stages. To our interest, PP2Cbeta(Delta/Delta) ES cells which had been generated by transfecting PP2Cbeta(3lox/3lox) ES cells with Cre-expressing plasmid were viable. In addition, knockdown of PP2Cbeta using siRNA did not affect the proliferation of wild-type ES cells. These observations suggest that relatively high PP2Cbeta expression is specifically required during the early stages of pre-implantation development. The possible mechanisms for the early pre-implantation lethality of PP2Cbeta(Delta/Delta) mice are discussed.

Pluripotency governed by Sox2 via regulation of Oct3/4 expression in mouse embryonic stem cells

The pluripotency of embryonic stem (ES) cells is thought to be maintained by a few key transcription factors, including Oct3/4 and Sox2. The function of Oct3/4 in ES cells has been extensively characterized, but that of Sox2 has yet to be determined. Sox2 can act synergistically with Oct3/4 in vitro to activate Oct-Sox enhancers, which regulate the expression of pluripotent stem cell-specific genes, including Nanog, Oct3/4 and Sox2 itself. These findings suggest that Sox2 is required by ES cells for its Oct-Sox enhancer activity. Using inducible Sox2-null mouse ES cells, we show that Sox2 is dispensable for the activation of these Oct-Sox enhancers. In contrast, we demonstrate that Sox2 is necessary for regulating multiple transcription factors that affect Oct3/4 expression and that the forced expression of Oct3/4 rescues the pluripotency of Sox2-null ES cells. These results indicate that the essential function of Sox2 is to stabilize ES cells in a pluripotent state by maintaining the requisite level of Oct3/4 expression.

Efficient conversion of ES cells into myogenic lineage using the gene-inducible system

We established genetically engineered ES (ZHTc6-MyoD) cells that harbor a tetracycline-regulated expression vector encoding myogenic transcriptional factor MyoD, for the therapy of muscle diseases, especially Duchenne muscular dystrophy (DMD). Almost all the ZHTc6-MyoD cells were induced into muscle lineage after removal of tetracycline. The undifferentiated ZHTc6-MyoD cells are Sca-1+ and c-kit+, but CD34-, all well-known markers for mouse hematopoietic stem cells. In addition, they are able to maintain themselves in the undifferentiated state, even after one month of culture. Therefore, it is possible to obtain a large quantity of ZHTc6-MyoD cells in the undifferentiated state that maintain the potential to differentiate only into muscle lineage. Additionally, at two weeks post-injection of these cells into muscle of mdx, a model mouse of DMD, clusters of dystrophin-positive myofibers were observed at the injection site. Therefore, ES cells have considerable therapeutic potential for treating muscle diseases.

Activin-Nodal signaling is involved in propagation of mouse embryonic stem cells

Embryonic stem (ES) cells are self-renewing cells that maintain pluripotency to differentiate into all types of cells. Because of their potential to provide a variety of tissues for use in regenerative medicine, there is great interest in the identification of growth factors that govern these unique properties of ES cells. However, the signaling pathways controlling ES cell proliferation remain largely unknown. Since transforming growth factor beta (TGFbeta) superfamily members have been implicated in the processes of early embryogenesis, we investigated their roles in ES cell self-renewal. Inhibition of activin-Nodal-TGFbeta signaling by Smad7 or SB-431542 dramatically decreased ES cell proliferation without decreasing ES pluripotency. By contrast, inhibition of bone morphogenetic protein (BMP) signaling by Smad6 did not exhibit such effects, suggesting that activin-Nodal-TGFbeta signaling, but not BMP signaling, is indispensable for ES cell propagation. In serum-free culture, supplementation of recombinant activin or Nodal, but not TGFbeta or BMP, significantly enhanced ES cell propagation without affecting pluripotency. We also found that activin-Nodal signaling was constitutively activated in an autocrine fashion in serum-free cultured ES cells, and that inhibition of such endogenous signaling by SB-431542 decreased ES cell propagation in serum-free conditions. These findings suggest that endogenously activated autocrine loops of activin-Nodal signaling promote ES cell self-renewal.

Prox1 induces lymphatic endothelial differentiation via integrin alpha9 and other signaling cascades

During embryonic lymphatic development, a homeobox transcription factor Prox1 plays important roles in sprouting and migration of a subpopulation of blood vessel endothelial cells (BECs) toward VEGF-C-expressing cells. However, effects of Prox1 on endothelial cellular behavior remain to be elucidated. Here, we show that Prox1, via induction of integrin alpha9 expression, inhibits sheet formation and stimulates motility of endothelial cells. Prox1-expressing BECs preferentially migrated toward VEGF-C via up-regulation of the expression of integrin alpha9 and VEGF receptor 3 (VEGFR3). In mouse embryos, expression of VEGFR3 and integrin alpha9 is increased in Prox1-expressing lymphatic endothelial cells (LECs) compared with BECs. Knockdown of Prox1 expression in human LECs led to decrease in the expression of integrin alpha9 and VEGFR3, resulting in the decreased chemotaxes toward VEGF-C. These findings suggest that Prox1 plays important roles in conferring and maintaining the characteristics of LECs by modulating multiple signaling cascades and that integrin alpha9 may function as a key regulator of lymphangiogenesis acting downstream of Prox1.

How is pluripotency determined and maintained?

Mouse embryonic stem (ES) cells are pluripotent, as they have the ability to differentiate into the various cell types of a vertebrate embryo. Pluripotency is a property of the inner cell mass (ICM), from which mouse ES cells are derived, and of the epiblast of the blastocyst. Recent extensive molecular studies of mouse ES cells have revealed the unique molecular mechanisms that govern pluripotency. These studies show that ES cells continue to self-renew because of a self-organizing network of transcription factors that prevents their differentiation and promotes their proliferation, and because of epigenetic processes that might be under the control of the pluripotent transcription factor network.

[Case of myotonic dystrophy eventually diagnosed by preoperative Allen's test]

A 59-year-old woman was scheduled for resection of a parotid tumor under general anesthesia. Preoperative interview was done 7 days before the operation. Laboratory data were normal except for a slightly elevated CPK level. Though ECG showed abnormal P and T waves, exercise ECG was normal. Respiratory function test revealed decreased %VC. She did not complain of motor weakness and atrophy of distal muscles. When the anesthesiologist did Allen's test, slow relaxation of hand grip, i.e. grip myotonia, was observed. Further history taking disclosed that she had a family history of myotonic dystrophy (MD) in her son. She was diagnosed as MD by a neurologist on the day of preoperative interview, although she lacked obvious symptoms and consciousness of MD. The operation was performed as scheduled and she was anesthetized with oxygen-nitorous oxide, propofol, fentanyl and vecuronium. Vecuronium was not antagonized because of the adverse effect of neostigmine reported in MD patients. The operation and anesthesia were conducted uneventfully. Her recovery from anesthesia was so smooth that she was discharged uneventfully. In this case, careful examination led to diagnosis of MD and prevented perioperative complications associated with MD. It is important to examine patients meticulously not to miss trivial symptoms in our daily visits.

Dissecting Oct3/4-regulated gene networks in embryonic stem cells by expression profiling

POU transcription factor Pou5f1 (Oct3/4) is required to maintain ES cells in an undifferentiated state. Here we show that global expression profiling of Oct3/4-manipulated ES cells delineates the downstream target genes of Oct3/4. Combined with data from genome-wide chromatin-immunoprecipitation (ChIP) assays, this analysis identifies not only primary downstream targets of Oct3/4, but also secondary or tertiary targets. Furthermore, the analysis also reveals that downstream target genes are regulated either positively or negatively by Oct3/4. Identification of a group of genes that show both activation and repression depending on Oct3/4 expression levels provides a possible mechanism for the requirement of appropriate Oct3/4 expression to maintain undifferentiated ES cells. As a proof-of-principle study, one of the downstream genes, Tcl1, has been analyzed in detail. We show that Oct3/4 binds to the promoter region of Tcl1 and activates its transcription. We also show that Tcl1 is involved in the regulation of proliferation, but not differentiation, in ES cells. These findings suggest that the global expression profiling of gene-manipulated ES cells can help to delineate the structure and dynamics of gene regulatory networks.

Functional characterization of Musca glutamate- and GABA-gated chloride channels expressed independently and coexpressed in Xenopus oocytes

Ligand-gated chloride channels (LGICs) are important targets for insecticides and parasiticides. Genes encoding subunits of two LGICs, a glutamate-gated chloride channel (MdGluCl-alpha) and a gamma-aminobutyric acid (GABA)-gated chloride channel (MdRdl), were cloned from house-flies (Musca domestica L.). These genes were first expressed independently in Xenopus laevis oocytes by cRNA injection in order to investigate the pharmacology of these ligand-gated channels using two-electrode voltage-clamp electrophysiology. It was found that L-glutamate and GABA activated the MdGluCl-alpha homo-oligomers with an EC(50) value of 30 microM and the MdRdl homo-oligomers with an EC(50) value of 101 microM, respectively. Both channels were chloride ion-permeable, and the MdRdl channel was more sensitive to chloride channel blockers, such as gamma-hexachlorocyclohexane (gamma-HCH), fipronil and picrotoxinin, than the MdGluCl-alpha channel. MdGluCl-alpha required only 1-2 days of incubation after cRNA injection to be expressed in oocytes, whereas 4-7 days of incubation was necessary to achieve MdRdl expression. However, when the cRNA of MdGluCl-alpha was injected at a dose of 1% (w/w) 1 day after the injection of the cRNA of MdRdl, a significant increase in the current amplitude of responses to GABA was observed, and the incubation period necessary for MdRdl expression became shorter. These results suggest that MdGluCl-alpha assists in the expression of MdRdl when the two are coexpressed.

Proline-glutamic acid-proline-lysine peptide set as a specific antigen for the serological diagnosis of strangles

The reactivity of synthesised peptide sets for the M-like proteins SeM and SzPSe with sera from horses infected with Streptococcus equi or Streptococcus zooepidemicus, or control horses, was investigated by an ELISA. Seventeen horses were infected experimentally with S equi or S zooepidemicus, convalescent sera were obtained from 25 horses and control sera were obtained from 1945 horses. The serum antibody responses of individual horses to the peptide sets were highly variable. Some of the peptide sets for SeM reacted strongly with the sera from the horses infected experimentally with S equi, but also reacted with sera from some of the horses infected experimentally with S zooepidemicus. However, the proline-glutamic acid-proline-lysine (PEPK) repeats peptide set, synthesised from the PEPK repeats areas of SzPSe, reacted most strongly with the sera from the horses infected experimentally with S equi and the horses convalescing from strangles, and reacted only minimally with the sera from the horses infected experimentally with S zooepidemicus and the control horses.

Inhibition of DNA binding of Sox2 by the SUMO conjugation

Sox2 is a member of the high mobility group (HMG) domain DNA-binding proteins for transcriptional control and chromatin architecture. The HMG domain of Sox2 binds the DNA to facilitate transactivation by the cooperative transcription factors such as Oct3/4. We report that mouse Sox2 is modified by SUMO at lysine 247. Substitution of the target lysine to arginine lost the sumoylation but little affected transcriptional potential or nuclear localization of Sox2. By contrast with the unmodified form, Sox2 fused to SUMO-1 did not augment transcription via the Fgf4 enhancer in the presence of Oct3/4. Further, SUMO-1-conjugated Sox2 at the lysine 247 or at the carboxyl terminus reduced the binding to the Fgf4 enhancer. These indicate that Sox2 sumoylation negatively regulates its transcriptional role through impairing the DNA binding.

Klf4 cooperates with Oct3/4 and Sox2 to activate the Lefty1 core promoter in embryonic stem cells

Although the POU transcription factor Oct3/4 is pivotal in maintaining self renewal of embryonic stem (ES) cells, little is known of its molecular mechanisms. We previously reported that the N-terminal transactivation domain of Oct3/4 is required for activation of Lefty1 expression (H. Niwa, S. Masui, I. Chambers, A. G. Smith, and J. Miyazaki, Mol. Cell. Biol. 22:1526-1536, 2002). Here we test whether Lefty1 is a direct target of Oct3/4. We identified an ES cell-specific enhancer upstream of the Lefty1 promoter that contains binding sites for Oct3/4 and Sox2. Unlike other known Oct3/4-Sox2-dependent enhancers, however, this enhancer element could not be activated by Oct3/4 and Sox2 in differentiated cells. By functional screening of ES-specific transcription factors, we found that Krüppel-like factor 4 (Klf4) cooperates with Oct3/4 and Sox2 to activate Lefty1 expression, and that Klf4 acts as a mediating factor that specifically binds to the proximal element of the Lefty1 promoter. DNA microarray analysis revealed that a subset of putative Oct3/4 target genes may be regulated in the same manner. Our findings shed light on a novel function of Oct3/4 in ES cells.

[A study of high-resolution computed tomography (HRCT) findings of resected small pulmonary nodules 2 cm or less in diameter with reference to the malignant nature]

To identify the characteristics of peripheral small lung mass lesions on high-resolution computed tomography (HRCT) and discriminate between malignant and benign, 223 mass lesions 2 cm or less resected surgically were evaluated about following points. 1) Density : 90.7% of lesions with mixed solid and ground-glass opacity (GGO) components were adenocarcinomas. Pure GGO lesions without scale-down between several months were all adenocarcinomas or atypical adenomatous hyperplasia (AAH). Thereby, patients with these findings are good candidates for surgical resection. 2) Spicular or pleural indentation :75.2% (88 of 117 cases) of adenocarcinomas and all squamous cell carcinomas (18 cases) showed these findings, but 26.6% (41 of 154 cases) of positive cases were benign lesion (non-specific inflammation, mycobacterisis, and so on). Accordingly, they are not peculiar to malignancy. 3) Satellite lesion : all lesions with this one showed benign, therefore it was thought that this finding could exclude malignant lesion. Thus, recognition of certain characteristics at HRCT can be helpful in discrimination between small malignant mass and benign mass.

Nasotracheal intubation under curve-tipped suction catheter guidance reduces epistaxis

BACKGROUND

Nasotracheal intubation (NTI) has greater potential for trauma of nasopharyngeal mucosa than orotracheal intubation. The present study investigated the success rate of NTI and frequency of nasal bleeding using a curve-tipped suction catheter (CTSC) to guide nasotracheal tube advancement.

METHODS

Subjects comprised 131 adult patients who under-went NTI. Subjects were randomly divided into two groups: a) NTI under CTSC guidance (G[+] group). The CTSC (14 Fr) was first inserted through the tracheal tube, with the tip of the CTSC emerging from the distal end of the tube. The curved tip was directed ventrally. Both tracheal tube and CTSC were advanced together through the nasopharynx; b) NTI without CTSC guidance (G[-] group). The tracheal tube was advanced into the nasal cavity and passed into the pharynx without CTSC guidance. The time required to pass the endotracheal tube through the nasal cavity (nasal passage time), success rate of nasal passage with nasotracheal tube, and the incidence and severity of nasal bleeding were compared.

RESULTS

Success rate for nasal passage was 100% in the G(+) group (62/62) and 82.6% in the G(-) group (57/69; P = 0.0006). Frequency of nasal bleeding was significantly lower in the G(+) group (21/62, 33.9%) than in the G(-) group (37/69, 53.6%; P = 0.023). Severity of nasal bleeding was also significantly lower in the G(+) group than in the G(-) group (P = 0.030).

CONCLUSIONS

Nasotracheal intubation under CTSC guidance increases the success rate of airway instrumentation, and also reduces the incidence and severity of epistaxis.

Nuclear and chromatin reorganization in the MHC-Oct3/4 locus at developmental phases of embryonic stem cell differentiation

Epigenetic gene control is involved in mechanisms of development. Little is known about the cooperation of nuclear and chromatin events in programmed differentiation from mouse embryonic stem cells (ESC). To address this, Oct3/4-positive ESC and differentiated progenies, Sox1-positive neural precursor cells (NPC) and post-mitotic neurons (PMN), were isolated using a stage-selected culture system. We first investigated global nuclear organization at the each stage. Chromocenter preexists in ESC, disperses in NPC and becomes integrated into large heterochromatic foci in PMN, while the formation of PML bodies markedly decreases in neural differentiation. We next focused on the gene-dense MHC-Oct3/4 region. Oct3/4 gene is expressed preferentially adjacent to PML bodies in ESC and are repressed in the absence of chromocenter association in NPC and PMN. Histone deacetylation in NPC, demethylation of lysine 4 of histone H3 (H3K4), tri-methylation of H3K27, and CpG methylation in PMN are targeted for the Oct3/4 promoter within the region. Interestingly, di-methyl H3K4 mark is present in Oct3/4 promoter in NPC as well as ESC. These findings provide insights into the molecular basis of global nuclear reorganization and euchromatic gene silencing in differentiation through the spatiotemporal order of epigenetic controls.

Synergistic action of Wnt and LIF in maintaining pluripotency of mouse ES cells

Leukaemia inhibitory factor (LIF) was the first soluble factor identified as having potential to maintain the pluripotency of mouse embryonic stem (ES) cells. Recently, a second factor, Wnt, with similar activity was found. However, the relationship between these completely different signals mediating the overlapping functions is still unclear. Here, we report that the conditioned medium of L cells expressing Wnt3a maintains ES cells in the undifferentiated state in feeder-free culture, followed by expression of stem cell markers and their ability to generate germline chimaeras. However, although the activity of this conditioned medium is dependent on Wnt3a, recombinant Wnt3a protein cannot maintain ES cells in the undifferentiated state. As supplementation with Wnt3a to the sub-threshold level of LIF alone was not sufficient to maintain ES self-renewal, the results of maintenance of the undifferentiated state indicated the synergistic action of Wnt and LIF. Induction of constitutively activated beta-catenin alone is unable to maintain ES self-renewal but shows a synergistic effect with LIF. These observations indicate that the Wnt signal mediated by the canonical pathway is not sufficient but enhances the effect of LIF to maintain self-renewal of mouse ES cells.