Novel thin bronchoscope with a 1.7-mm working channel for peripheral pulmonary lesions

In the present study, the authors evaluated the diagnostic utility of a novel thin bronchoscope with a 1.7-mm working channel for peripheral pulmonary lesions. A total of 118 patients were included in this prospective study. Bronchoscopic examination was performed using a 5.9-mm standard bronchoscope. If no visible endobronchial lesion was found, transbronchial biopsies were performed with 1.5-mm biopsy forceps under fluoroscopic guidance and the bronchus were washed with 10-20 mL of saline solution, using a prototype 3.5-mm thin bronchoscope with a 1.7-mm working channel. Endobronchial lesion was visualised with the standard bronchoscope in 16 patients, and the other 102 patients underwent biopsies with the thin bronchoscope. The mean bronchus levels reached with the standard bronchoscope and the thin bronchoscope were 2.3 and 4.3 generations, respectively. Endobronchial abnormality was revealed with the thin bronchoscope in a further 14 patients. Diagnostic material was obtained in 50 of 68 (74%) patients with malignant disease and 18 of 30 (60%) patients with benign disease. Four patients did not return to follow-up. The diagnostic yield was 57%, even in lesions <20 mm. There were no major complications. In conclusion, bronchoscopy using a 3.5-mm thin bronchoscope with a 1.7-mm working channel is useful and safe for the diagnosis of peripheral pulmonary lesions.

Identification of novel suppressors for Mog1 implies its involvement in RNA metabolism, lipid metabolism and signal transduction

Mog1 is conserved from yeast to mammal, but its function is obscure. We isolated yeast genes that rescued a temperature-sensitive death of S. cerevisiae Scmog1Delta, and of S. pombe Spmog1(ts). Scmog1Delta was rescued by Opi3p, a phospholipid N-methyltransferase, in addition to S. cerevisiae Ran-homologue Gsp1p, and a RanGDP binding protein Ntf2p. On the other hand, Spmog1(ts) was rescued by Cid13 that is a poly (A) polymerase specific for suc22(+) mRNA encoding a subunit of ribonucleotide reductase, Ssp1 that is a protein kinase involved in stress response pathway, and Crp79 that is required for mRNA export, in addition to Spi1, S. pombe Ran-homologue, and Nxt2, S. pombe homologue of Ntf2p. Consistent with the identification of those suppressors, lack of ScMog1p dislocates Opi3p from the nuclear membrane and all of Spmog1(ts) showed the nuclear accumulation of mRNA. Furthermore, SpMog1 was co-precipitated with Nxt2 and Cid13.

Characterization of the immune escape phenotype of human gastric cancers with and without high-frequency microsatellite instability

Gastric cancers with and without high-frequency microsatellite instability (MSI-H) represent distinctive pathways of carcinogenesis. The aim of this study was to clarify if human leukocyte antigen (HLA) class I antigen subunits and antigen processing machinery (APM) components are differentially downregulated in these two groups of tumours. Using reverse transcription PCR (RT-PCR), loss of heterozygosity (LOH) analysis, methylation-specific PCR (MSP), DNA sequencing, immunohistochemistry, and flow cytometry, we analysed expression and/or alteration of HLA class I antigen subunits and APM components, including low molecular weight polypeptide proteasome subunit (LMP)2, LMP7, LMP10, transporter associated with antigen processing (TAP)1, TAP2, tapasin, proteasome activator (PA) 28alpha, and PA28beta in two stage-matched panels of 30 MSI-H and 30 microsatellite stable (MSS) gastric cancers. Mutations at coding microsatellites (cMS) located within beta2-microglobulin (beta2m) and genes encoding APM components, including endoplasmic reticulum (ER) chaperone protein genes, such as calnexin, SEC63, SEC31, and P4HB (p55), were also analysed. HLA class Ia transcripts were totally downregulated in 18.3% of cancer cases. Locus-specific downexpression of HLA-A, -B, and -C was detected in 41.7%, 45.0%, and 31.7% of cases. Loss of HLA-A was significantly more frequent in MSI-H cancers. The LOH ratios of the HLA-A, -B, and -C loci microsatellite markers were relatively low: 5/32 (15.6%) for D6S306, 4/32 (12.5%) for D6S258, 4/33 (12.1%) for D6S273, and 4/30 (13.3%) for D6S1666. Methylation of HLA-A, -B, and -C was detected in 38.3%, 40.0%, and 28.3% of cases. A significant association between methylation and reduction in expression was observed in gastric cancer tissues. Mutations at cMS of beta2m and APM components were detected in 3.3-46.7% of MSI-H cancers but in none of MSS cancers. These data show that gastric cancers have various defects in HLA class I antigen subunits and APM components and that the MSI phenotype is associated with frequent HLA-A inactivation and frameshift mutations of the beta2m and APM genes.

Role of histone phosphorylation in chromatin dynamics and its implications in diseases

In eukaryotic cells, relaxed interphase chromatin undergoes pronounced changes resulting in formation of highly condensed mitotic chromosomes. Moreover, chromatin condensation is particularly evident during mitosis and apoptotic cell death, whereas chromatin relaxation is necessary for replication, repair, recombination and transcription. The post-translational modifications of histone tails such as reversible acetylation, phosphorylation and methylation play a critical role in dynamic condensation/relaxation that occurs during the cell cycle. Histone phosphorylation is believed to play a direct role in mitosis, cell death, repair, replication and recombination. However, definitive roles for this modification in these processes have not yet been elucidated. In this review, we discuss recent progress in studies of histone phosphorylation.

Temperature-sensitive defects of the GSP1gene, yeast Ran homologue, activate the Tel1-dependent pathway

RanGTPase is involved in many cellular processes. It functions in nuclear-cytosolic transport and centrosome formation. Ran also localizes to chromatin as RCC1 does, its guanine nucleotide exchange factor, but Ran's function on chromatin is not known. We found that gsp1, a temperature-sensitive mutant of GSP1, a Saccharomyces cerevisiae Ran homologue, suppressed the hydroxyurea (HU) and ultra violet (UV) sensitivities of the mec1 mutant. In UV-irradiated mec1 gsp1 cells, Rad53 was phosphorylated despite the lack of Mec1. This suppression depended on the TEL1 gene, given that the triple mutant, mec1 gsp1 tel1, was unable to grow. The gsp1 mutations also suppressed the HU sensitivity of the rad9 mutant in a Tel1-dependent manner, but not the HU sensitivity of the rad53 mutant. These results indicated that Rad53 was activated by the Tel1 pathway in mec1 gsp1 cells, suggesting that Gsp1 helps regulate the role switching the ATM family kinases Mec1 and Tel1.

Different mating-type-regulated genes affect the DNA repair defects of Saccharomyces RAD51, RAD52 and RAD55 mutants

Saccharomyces cerevisiae cells expressing both a- and alpha-mating-type (MAT) genes (termed mating-type heterozygosity) exhibit higher rates of spontaneous recombination and greater radiation resistance than cells expressing only MATa or MATalpha. MAT heterozygosity suppresses recombination defects of four mutations involved in homologous recombination: complete deletions of RAD55 or RAD57, an ATPase-defective Rad51 mutation (rad51-K191R), and a C-terminal truncation of Rad52, rad52-Delta327. We investigated the genetic basis of MAT-dependent suppression of these mutants by deleting genes whose expression is controlled by the Mata1-Matalpha2 repressor and scoring resistance to both campothecin (CPT) and phleomycin. Haploid rad55Delta strains became more damage resistant after deleting genes required for nonhomologous end-joining (NHEJ), a process that is repressed in MATa/MATalpha cells. Surprisingly, NHEJ mutations do not suppress CPT sensitivity of rad51-K191R or rad52-Delta327. However, rad51-K191R is uniquely suppressed by deleting the RME1 gene encoding a repressor of meiosis or its coregulator SIN4; this effect is independent of the meiosis-specific homolog, Dmc1. Sensitivity of rad52-Delta327 to CPT was unexpectedly increased by the MATa/MATalpha-repressed gene YGL193C, emphasizing the complex ways in which MAT regulates homologous recombination. The rad52-Delta327 mutation is suppressed by deleting the prolyl isomerase Fpr3, which is not MAT regulated. rad55Delta is also suppressed by deletion of PST2 and/or YBR052C (RFS1, rad55 suppressor), two members of a three-gene family of flavodoxin-fold proteins that associate in a nonrandom fashion with chromatin. All three recombination-defective mutations are made more sensitive by deletions of Rad6 and of the histone deacetylases Rpd3 and Ume6, although these mutations are not themselves CPT or phleomycin sensitive.

The vibratory characteristics of obturators with different bulb height and form designs

The aim of the present study was to investigate whether the vibratory characteristics of obturator prostheses are affected by bulb design, i.e.: the hollow or buccal flange type, and different lateral and medial bulb heights. Buccal flange and hollow bulb obturator prostheses were fabricated with two different lateral bulb wall heights and two different medial bulb wall heights. Ultimately, eight obturator prostheses were prepared for evaluation of their vibratory characteristics. The frequency-response functions were recorded on an FFT analyzer to identify their vibratory characteristics. A transient response simulation was carried out in which an impact was applied to the non-defect side. The decay rate, damping time and maximum amplitude of the retainers were statistically analysed by anova with Scheffé's test (P < 0.05). The decay rate of every buccal flange type was higher and damping time was shorter than those of every hollow type, except between a pair with low lateral and low medial bulb walls. The maximum amplitude values of four obturators with low medial bulb walls were significantly lower than those of four obturators with high medial walls. The buccal flange obturator prosthesis with high lateral and low medial walls showed the maximum decay rate and the minimum amplitude of the retainers on molars. Vibration analysis suggests that a buccal flange obturator prosthesis with high lateral and low medial walls is preferable.

H2A.Z functions to regulate progression through the cell cycle

Histone H2A variants are highly conserved proteins found ubiquitously in nature and thought to perform specialized functions in the cell. Studies in yeast on the histone H2A variant H2A.Z have shown a role for this protein in transcription as well as chromosome segregation. Our studies have focused on understanding the role of H2A.Z during cell cycle progression. We found that htz1delta cells were delayed in DNA replication and progression through the cell cycle. Furthermore, cells lacking H2A.Z required the S-phase checkpoint pathway for survival. We also found that H2A.Z localized to the promoters of cyclin genes, and cells lacking H2A.Z were delayed in the induction of these cyclin genes. Several different models are proposed to explain these observations.

Barrier function at HMR

The silenced HMR domain is restricted from spreading by barrier elements, and the right barrier is a unique t-RNA(THR) gene. We show that sequences immediately flanking the silenced domain were enriched in acetylated, but not methylated, histones, whereas the barrier element was associated with a nucleosome-free region. Surprisingly, the SAGA acetyltransferase resided across the entire region. We further demonstrate that a mutation in the barrier eliminated the nucleosome-free gap but only subtly altered the distribution of SAGA. Interestingly, neither reformation of the nucleosome nor mutations in chromatin-modifying enzymes alone led to an unrestricted spread of silenced chromatin. Double mutations in the t-RNA barrier and these complexes, on the other hand, led to a significant spread of Sir proteins. These results suggest two overlapping mechanisms function to restrict the spread of silencing: one of which involves a DNA binding element, whereas the other mechanism involves specific chromatin-modifying activities.

Barrier proteins remodel and modify chromatin to restrict silenced domains

Transcriptionally active and inactive domains are frequently found adjacent to one another in the eukaryotic nucleus. To better understand the underlying mechanisms by which domains maintain opposing transcription patterns, we performed a systematic genomewide screen for proteins that may block the spread of silencing in yeast. This analysis identified numerous proteins with efficient silencing blocking activities, and some of these have previously been shown to be involved in chromatin dynamics. We isolated subunits of Swi/Snf, mediator, and TFIID, as well as subunits of the Sas-I, SAGA, NuA3, NuA4, Spt10p, Rad6p, and Dot1p complexes, as barrier proteins. We demonstrate that histone acetylation and chromatin remodeling occurred at the barrier and correlated with a block to the spread of silencing. Our data suggest that multiple overlapping mechanisms were involved in delimiting silenced and active domains in vivo.

Nonmyeloablative stem cell transplantation with fludarabine and cyclophosphamide for patients with hematologic malignancies

We conducted a multi-center phase I/II trial of nonmyeloablative stem cell transplantation for patients with hematologic malignancies. The aim of this trial was to assess the safety and feasibility of this treatment modality for older or younger patients with significant organ dysfunction, who could not be treated with conventional high dose chemoradiotherapy. Twelve patients were treated with a conditioning regimen consisting of fludarabine and cyclophosphamide, followed by peripheral blood stem cell transplantation from human leukocyte antigen (HLA) identical siblings. Nonhematologic toxicities were mild. Median time to absolute neutrophils above 0.5 x 10(9)/l, 1.0 x 10(9)/l and platelets above 50 x 10(9)/l were 8, 10 and 12 days, respectively. Donor dominant hematopoiesis was achieved in all patients, with or without donor leukocyte infusion. The cumulative incidence of acute and chronic graft-versus-host disease (GVHD) was 75 and 56%, respectively. Only one patient experienced early death within 100 days, caused by acute GVHD complicated by fungal infection. All patients except one achieved complete remission. With a median follow-up of 330 days, expected progression-free survival is 75%. Overall survival is 76%. Our study confirms that nonmyeloablative stem cell transplantation with cyclophosphamide and fludarabine conditioning is a safe and promising treatment for elderly patients with hematologic malignancies. A further study in large-scale setting is warranted.

Blockers and barriers to transcription: competing activities?

In the eukaryotic cell active and inactive genes reside adjacent to one another and are modulated by numerous regulatory elements. Insulator elements prevent the misregulation of adjacent genes by restricting the effects of the regulatory elements to specific domains. Enhancer blockers prevent enhancers from inadvertently activating neighboring genes, and recent results suggest that they might function by a conserved mechanism across species. These elements appear to disrupt enhancer-promoter "communications" by interacting with the regulatory elements and sequestering these elements into specific regions of the nucleus thus rendering them non-functional. Barrier elements insulate active genes from neighboring heterochromatin and recent results suggest that they function by specific localized recruitment of acetyltransferases that antagonize the spread of heterochromatin-associated deacetylases, thus preventing the propagation of heterochromatin.

Vibration analysis of maxillary removable partial denture frameworks

The purpose of this study was to investigate the vibratory characteristics of three designs of the Class I Kennedy maxillary removable partial denture frameworks as the basic study. Their major connectors comprised a U-shaped palatal connector (UPC), single palatal bar (SPB), and anterior-posterior palatal bars (APB). Frequency response functions were measured when the framework was impacted. The modal shape was observed and the decay rate was calculated using modal analysis software. The results showed that the vibratory properties of each framework differed from each other. Within the range of frequencies from 10 to 2000 Hz, the UPC type had seven natural frequencies, while the SPB and the APB types had six. The UPC type had a greater number of natural modes accompanied by elastic deformation, including fluttering and twisting, than the other type, and the UPC type was considered to be unfavourable. The decay rate of the APB type was significantly higher than those of the UPC and the SPB types (P < 0.01).

Efficient lentiviral transduction of human cord blood CD34(+) cells followed by their expansion and differentiation into dendritic cells

OBJECTIVE

To support immune reconstitution after cord blood transplantation, immunotherapy using gene-modified dendritic cells (DCs), the most potent antigen-presenting cells, can be a powerful strategy for preventing infection and recurrence. To investigate the applicability of lentiviral vector-transduced DCs compared to retroviral vectors, we transduced umbilical cord blood (CB) CD34(+) cells, then expanded and differentiated them into DCs.

MATERIALS AND METHODS

We transduced CB CD34(+) cells by vesicular stomatitis virus G-protein pseudotyped self-inactivating lentiviral vector or retroviral vectors carrying the enhanced green fluorescent protein gene. The cells were expanded in the stroma-dependent culture system and transferred to the culture condition for developing DCs. The efficiency of transduction and expression of the transgene in severe combined immunodeficiency (SCID) mice-repopulating cells (SRCs) and DCs were compared between lentiviral vector and retroviral vectors. Induced DCs were cocultured with allogeneic or autologous T cells to test the ability to present antigens.

RESULTS

CB CD34(+) cells transduced by lentiviral vector and expanded ex vivo sustained stable transgene expression and multipotentiality by assessing SRCs assay and clonogenic assay of bone marrow cells from the transplanted mice. DCs derived from these cells expressed green fluorescent protein and surface markers CD1a, CD80, and HLA-DR and showed potent allo-stimulatory activity as well as nontransduced DCs did. On the other hand, we did not detect transgene expression in SRCs and DCs transduced by retroviral vectors.

CONCLUSION

Gene-modified DCs derived from ex vivo expanded CB CD34(+) cells transduced by lentiviral vector will be useful in future immunotherapy protocols.

Modal analysis of the maxillary dentition in cleft lip and palate patients before and after bone grafting

The aim of this study was to analyze the vibratory characteristics in the maxillary dentition of 4 cleft lip and palate (CLP) patients before and after bone grafting. First, the central incisor on the noncleft side was impacted with an impact hammer, and the responses were received using an acceleration sensor from the teeth between the upper first molars on both sides. The transfer functions were then obtained from each measurement point using a fast Fourier transform analyzer. Finally, a computer analysis and simulation were performed based on the measured transfer functions to obtain the natural frequency, modal shape, decay rate (DR) and maximum displacement (MDP). Before bone grafting, distinct phase differences between the major and minor dental arches (MDA and mDA) were observed in the modal shapes. After surgery, however, both the MDA and mDA vibrated in phase. These results were identical in all subjects. The MDPs of the central incisors conspicuously decreased after bone grafting in 3 subjects. From the standpoint of vibratory characteristics, this study indicated that bone grafting had a favorable effect on prosthodontic treatment using a fixed prosthesis across the cleft in CLP patients.

Extensive and long-term ex vivo production of dendritic cells from CD34 positive umbilical cord blood or bone marrow cells by novel culture system using mouse stroma

We previously developed a system using murine strome (HESS-5), which could expand umbilical cord blood (UCB) stem and progenitor cells, especially CD34+/38- cells, in the presence of human recombinant cytokines. In this study, the ability of expanded UCB- or bone marrow (BM)-CD34+ cells to differentiate into dendritic cells (DCs) was examined. DCs could be induced either from short or long term cultured CD34+ cells after switching the cytokines from Flk-2/Flt-3 ligand, stem cell factor (SCF), thrombopoietin (TPO) to granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) (immature type) plus tumor necrosis factor (TNF)-alpha with stimulation by CD40L transfectant (mature type). Each immature or mature UCB-DCs showed a dextran uptake or a potent allo-T lymphocytes proliferative ability, respectively. Furthermore, those DCs from BM significantly stimulated auto-T lymphocytes in an antigen (varicella zoster virus) specific manner. In conclusion, a novel culture system using HESS-5 is useful to support a rapid and sustained generation of primitive myeloid cells which can develop into functional DCs.