The construction of an in vitro three-dimensional hematopoietic microenvironment for mouse bone marrow cells employing porous carriers

Spatial development of mouse bone marrow cellsemploying porous carriers was investigated in order todesign a bioreactor with a three-dimensionalhematopoietic microenvironment. Three types of porouscarriers were used for examining the spatialdevelopment of anchorage-dependent primary stromalcells as feeder cells. Stromal cells were found tospread well at a high density on a polyester nonwovendisc carrier (Fibra cel (FC)) under a scanningelectron microscope, while cells on porous cellulosebeads (Microcube (MC), 500 mum pore diameter)spread at a low density; cells on another type ofcellulose porous beads (CPB, 100 mum pore diameter)were globular. Mouse bone marrow cells wereinoculated to dishes containing three types of porouscarriers which shared more than 30% of the bottomsurface in a dish. The concentration of stromal cellsin the well containing FC was lower than that on theother two carriers. However, the weekly output oftotal hematopoietic cell (suspension cells) increasedbetween day 21 and 28 in the culture using FC while itdecreased monotonously in the cultures by use of theother two carriers. The proportion of progenitorcells (BFU-E, CFU-GM) in the total hematopoietic cellpopulation, after showing an initial decrease,increased after 1 week in the culture using FC whilethe proportion decreased monotonously to zero in thecultures using MC and CPB.

Immunohistochemical detection of mutated epidermal growth factor receptors in pulmonary adenocarcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) mutational analysis has become essential in determining a therapeutic strategy for lung cancer. This study validated the reliability of recently generated rabbit monoclonal antibodies that recognise specific mutations of the EGFR protein.

PATIENTS AND METHODS

Pulmonary adenocarcinoma tissue from 20 previously genotyped specimens was prepared for immunohistochemical staining by two antibodies that recognise products of in-frame deletions in exon 19 (E746_A750del) and a point mutation that replaces leucine with arginine at codon 858 in exon 21 (L858R) of the EGFR gene.

RESULTS

The findings of EGFR-mutation-specific immunohistochemistry were concordant with the results of DNA analysis in 18 of 20 tested samples leading to 90% sensitivity and 100% specificity of the method.

CONCLUSION

This immunohistochemical assay for products of representative EGFR gene mutations may be performed reliably using tissue specimens from resected pulmonary adenocarcinomas.

Antenatal glucocorticoid therapy accelerates ATP production with creatine kinase increase in the growth-enhanced fetal rat heart

BACKGROUND

Previous study has demonstrated the increase of several cardiac function-related proteins, including creatine kinase (CK) as an important enzyme in the process of ATP synthesis in the fetal heart of rats administered glucocorticoid (GC) antenatally. In the present study the effect of antenatal GC administration on the CK expression in fetal and neonatal hearts was demonstrated.

METHODS AND RESULTS

Dexamethasone was administered to pregnant rats on days 19 and 20 of gestation. The mRNA levels of the CK isoforms, CK-M and Mi-CK, in 21-day-old fetal and 1-day-old neonatal hearts were significantly increased after antenatal GC administration. CK protein levels were also increased in both cultured cardiomyocytes and the mitochondria of the hearts. Uptake of 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl-benzimidazolocarbocyanine iodide by mitochondria was significantly increased. An increased ATP level accompanied the CK increase in the neonatal hearts. Furthermore, in vitro these effects were mediated though the GC receptor of cardiomyocytes. Peroxisome proliferator-activated receptor gamma as the upstream transcription factor of CK was significantly increased in fetal hearts.

CONCLUSIONS

These results suggest that antenatal GC administration accelerates ATP synthesis through increased CK and may contribute to maturation of the premature heart so that it is ready for preterm delivery. (Circ J 2010; 74: 171 - 180).

Insulin-like growth factors I and II in the aseptic loosening of total hip implants

Periprosthetic interface tissue and pseudocapsule samples surrounding aseptically loosened hip implants and control knee synovium were studied by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Endothelial cells, fibroblasts, and monocyte/macrophages contained bone formation-enhancing insulin-like growth factors (IGFs). In interface tissue we found fewer IGF-I and IGF-II positive cells than in control tissue. In pseudocapsular tissue we found fewer IGF-I positive cells and an equal amount of IGF-II positive cells compared to control tissues. Decreased bone formation may contribute to net loss of bone around aseptically loosened hip implants.

Antenatal glucocorticoid therapy increase cardiac alpha-enolase levels in fetus and neonate rats

AIMS

Antenatal glucocorticoid therapy has been shown to prevent acute diseases including infant respiratory distress syndrome and reduce mortality, although little is known about the effects on cardiac function-related proteins in the fetus or neonate. We investigated whether cardiac function-related proteins were altered in cardiac tissues of fetuses and neonates born to pregnant rats treated by glucocorticoid.

MAIN METHODS

Dexamethasone (DEX) was administered to pregnant rats for 2 days on day 17 and 18 or day 19 and 20 of gestation to simulate antenatal DEX therapy, and cardiac tissues of 19- and 21-day fetuses and 1-, 3-, and 5-day neonates were analyzed using a proteomic technique with liquid chromatography-mass spectrometry/mass spectrometry.

KEY FINDINGS

The identified five proteins; alpha-enolase, creatine kinase-M type, beta-tubulin, troponin T, and ATP synthase beta-chain, were significantly increased in fetal cardiac tissues with DEX administration. We observed that significant increase of alpha-enolase in the 19-day fetuses by DEX using Western blotting and immunohistochemistry. ATP and cAMP levels were also increased in the fetal heart tissue. In addition, pyruvate levels were significantly increased in the fetus groups by DEX.

SIGNIFICANCE

These results suggest that increased alpha-enolase may contribute to acceleration of glycolysis in the preterm heart.

Evaluation of unexpected positive results from a commercial ELISA for antibodies to PRRSV

Unexpected positive results from the widely used IDEXX ELISA for the detection of antibodies to porcine reproductive and respiratory syndrome virus (PRRSV) may confound investigations of the disease. Supplementing the ELISA with blocking agents and the use of IgG purified from serum samples had no effect on the unexpected positive results, suggesting that they were due to an antibody-antigen reaction. Simple competitive and blocking ELISAs were developed by modifying the IDEXX ELISA, and they and an indirect fluorescent antibody test (IFAT) were used to examine PRRSV antibodies in 33 antibody-negative, 88 antibody-positive and 73 unexpectedly positive sera. All the unexpectedly positive sera were negative by IFAT, and 89.0 per cent were negative by both the competitive and blocking ELISAs. The competitive ELISA (97.7 per cent) and the blocking ELISA (96.5 per cent) detected more positive sera than the IFAT (90.9 per cent). These results show that both ELISAs are capable of distinguishing positive and unexpectedly positive sera, and suggest that most of the unexpected positive signals are false-positives.

Messenger RNA expression of angiotensin-converting enzyme, endothelin, cyclooxygenase-2 and prostaglandin synthases in bovine placentomes during gestation and the postpartum period

The bovine placenta contains local vasoactive-related systems, including angiotensin-converting enzyme (ACE), endothelin-1 (ET-1), ET-A receptor (ETAR) and ET-B receptor (ETBR), as well as arachidonic acid (AA) cascade-related enzymes, such as cyclooxygenase-2 (Cox-2), prostaglandin E-synthase (PGES) and prostaglandin F-synthase (PGFS). The mRNA expression of these molecules was examined in bovine placentomes (caruncles and cotyledons) collected immediately (0 h) and 6h after spontaneous parturition from 15 cows with early (fetal membranes released within 6 h of parturition) or late (fetal membranes released 6-12 h after parturition) detachment, as well as from 15 pregnant cows at a slaughterhouse. Significant differences were observed in expression of ET-1, ETAR and ETBR mRNAs between gestation and the postpartum period in both caruncles and cotyledons. Significant differences were also found between 0 and 6 h postpartum in the expression of ETBR mRNA in the early detachment group and PGES mRNA in the early and late detachment groups. Compared to PGFS, both Cox-2 and PGES exhibited opposite mRNA expression patterns during gestation and the postpartum period. The vasoactive-related peptide systems and AA cascade-related enzymes may mediate placental development and fetal membrane detachment after parturition in cattle.

Pneumococcal whole-cell vaccine: optimization of cell growth of unencapsulated Streptococcus pneumoniae in bioreactor using animal-free medium

The high cost of the available pneumococcal conjugated vaccines has been an obstacle in implementing vaccination programs for children in developing countries. As an alternative, Malley et al. proposed a vaccine consisting of inactivated whole-cells of unencapsulated S. pneumoniae, which provides serotype-independent protection and involves lower production costs. Although the pneumococcus has been extensively studied, little research has focused on its large-scale culture, thus implying a lack of knowledge of process parameters, which in turn are essential for its successful industrial production. The strain Rx1Al- eryR was originally cultured in Todd-Hewitt medium (THY), which is normally used for pneumococcus isolation, but is unsuitable for human vaccine preparations. The purposes of this study were to compare the strains Rx1Al- eryR and kanR, develop a new medium, and generate new data parameters for scaling-up the process. In static flasks, cell densities were higher for eryR than kanR. In contrast, the optical density (OD) of the former decreased immediately after reaching the stationary phase, and the OD of the latter remained stable. The strain Rx1Al- kanR was cultivated in bioreactors with medium based on either acid-hydrolyzed casein (AHC) or enzymatically hydrolyzed soybean meal (EHS). Biomass production in EHS was 2.5 times higher than in AHC, and about ten times higher than in THY. The process developed for growing the strain Rx1Al- kanR in pH-controlled bioreactors was shown to be satisfactory to this fastidious bacterium. The new culture conditions using this animal-free medium may allow the production of the pneumococcal whole-cell vaccine.

[Experience of complete Carney's triad showing pulmonary hamartoma associated with gastrointestinal stromal tumor and para-arotic paraganglioma]

A 34-year-old man, who had undergone the gastrectomy for gastrointestinal stromal tumor (GIST) and para-aortic paraganglioma 3 years before, was found to have a left lung tumor on a computed tomography. The tumor was revealed to be a pulmonary hamartoma, and diagnosed as Carney's triad. This is a rare case of complete type Carney's triad of an adult male.

Oviductal progesterone concentration and its spatial distribution in cyclic and early pregnant cows

Changes and local distribution of oviductal progesterone (P(4)) concentration during the estrous cycle and early pregnancy in cows were investigated. Intact reproductive tracts were collected from 16 Holstein cows at an abattoir. Samples were classified in to 4 stages (follicular, postovulatory, luteal and early pregnant,< 20 d) based on visual observation of corpus luteum (CL), uterine characteristics and luteal P(4) concentrations. Oviducts were separated from the uterus at the utero-tubal junction and divided into 4 parts: fimbriae, proximal, medial and distal parts. Luteal tissue samples were also collected. Progesterone levels in oviductal and luteal tissues were determined by radioimmunoassay (RIA). Comparatively higher (P < 0.001) P(4) levels were found in stages with a functioning CL ( luteal phase and early pregnancy) than in those with a regressing CL (follicular phase and post ovulation). The oviduct ipsilateral to the CL bearing ovary during the luteal phase and early pregnancy showed higher ( P < 0.001) P(4) concentrations than the contralateral side. Such a difference was not observed during the follicular phase or post ovulation. The ipsilateral oviduct to the functioning CL at early pregnancy showed higher (P <0.05) P(4) levels than at the luteal phase, while no significant difference in luteal P(4) levels between these 2 stages was observed. Neither were any differences in P(4) concentration within the oviduct observed during any phase of the estrous cycle or during early pregnancy. A positive relationship between luteal and oviductal P(4) concentrations was noted. In conclusion, changes in P(4) levels in the oviduct depend on the location and functional stage of the CL. Localized levels of P(4) in the oviduct may be due to local delivery of P(4) from the CL.

The expression of chicken NOV, a member of the CCN gene family, in early stage development

The nephroblastoma overexpressed gene, NOV, is a member of the CCN gene family. We investigated the NOV gene expression pattern in the chicken during early stage embryogenesis. Several embryonic structures showed a distinct expression pattern. The initial expression was detected in Hensen's node (Hamburger and Hamilton stage (HH) 5). The expression was noted in the presumptive notochord and floor plate forming cells. The expression on the left side was more elongated posteriorly, a type of left-right asymmetry. Chicken NOV gene expression in the forming notochord and floor plate was observed until HH 18. The expression was also detected in the ventral area of the mesencephalon and isthmus at HH 14-16.

Follow up of a multicenter phase II study of sequential paclitaxel and S-1 (TXL/S1) as postoperative adjuvant chemotherapy for gastric cancer (GC)

15084

Background: Of patients who undergo R0 resection for GC with serosal invasion (T3–4), more than half recur mainly in the peritoneum, while TXL and S1 exhibited efficacy for diffuse type and peritoneal metastases in the phase II studies. Primary analysis of the sequential chemotherapy with TXL/S1 had shown its safety and tolerability, its survival benefit is being tested in a large phase III study (the SAMIT trial) with oral fluoropyrimidines as controls. The analysis for survival of this preceding phase II study is performed. Methods: Eligibility criteria included histologically proven GC; sT3–4; sN0–2; M0 (except peritoneal cytology: CY); post D2–3 gastrectomy and R0–1; ECOG PS 0–1; and 20–80 years old. On postoperative day 14 to 56, patients received 3 courses of weekly TXL (80mg/m2 on day 1, 8 for the 1st course and on day 1, 8, 15 for the 2nd and 3rd courses, repeated every 3 or 4 weeks) followed by 4 courses of S1 (80mg/m2 daily for 2 weeks, repeated every 3 weeks). The primary endpoints were % of patients who completed all 7 courses (compliance) to see whether the lower 95% confidence limit of compliance was greater than 69% and incidence of severe toxicities and the secondary endpoints were 3-year survival and toxicities. Results: 50 patients were accrued from May 2003 to March 2004. The median age was 63 (range 34–74); male/female: 34/16; pT2/T3/T4: 1/44/5; CY0/CY1: 4/46; f-stage2/3a/3b/4: 12/15/16/7. The overall compliance was 84%. Median follow up time was 1063 days for survivors (694–1332) and 1030 days for all. Three-year DFS were 64.6% for all, 66.1% for CY0 and 50.0% for CY1. Conclusions: Sequential TXL/S1 may serve as an active adjuvant for gastric cancer patients especially who are at high risk for peritoneal spread.

No significant financial relationships to disclose.

Randomized phase III study of S-1 alone versus S-1 + cisplatin in the treatment for advanced gastric cancer (The SPIRITS trial) SPIRITS: S-1 plus cisplatin vs S-1 in RCT in the treatment for stomach cancer

4514

Background: S-1 has been widely used against advanced gastric cancer (AGC) not only as monotherapy but also in combination with other cytotoxic compounds. Results of a phase I/II study combining S-1 + cisplatin (CDDP) were very encouraging with a high response rate (RR) of 76%, and the MST (Median Survival Time) of 383 days (Koizumi W et al, Br J Cancer, 2003). Based on these results, a phase III study comparing S-1 alone with S-1 + CDDP has been conducted to further evaluate the efficacy and safety for S-1 + CDDP as a standard treatment for AGC. Methods: This is a randomized, controlled, open-label, parallel, multicenter study. Patients (pts) are randomized to one of two treatment arms. Arm A: Pts receive oral S-1 (40 mg/m2) twice daily 28 days followed by 14 days rest. Arm B: Pts receive oral S-1 (40 mg/m2) twice daily 21 days followed by 14 days rest plus CDDP (60 mg/m2) iv on day 8. Eligibility criteria included unresectable/recurrent AGC, age 20–74, no prior chemotherapy for AGC. Primary endpoint was overall survival (OS). Main secondary endpoints included RR, time to treatment failure (TTF) and toxicity. Based on planned sample size of 284 pts, the trial was designed to have 90% power to detect an improvement in median OS from 8 to 12 months (2-sided log-rank test; significance level 0.05). Results: 305 pts (Arm A/B, 152/153) were randomized between Mar 2002 and Nov 2004. The eligible pts were 299 (Arm A/B, 150/149). Median age was 62.0/61.5 yrs. At a 2 yrs follow-up since last patient in, the MST for Arm A was 335.5 days (95%CI: 292.0 - 402.0) and for Arm B was 396.0 days (95%CI: 342.0 - 471.0). The OS for Arm B was superior to Arm A (log-rank p=0.0366, hazard ratio: 0.774, 95% CI: 0.608 - 0.985). RR was 31.1% for Arm A and 54.0% for Arm B. In Arm A vs Arm B, the most common grade 3/4 toxicities were: leucopenia, 2.0% vs 11.5%; neutropenia, 10.7% vs 39.9%; anemia (decreased Hb), 4.0% vs 25.7%; nausea, 1.3% vs 11.5%; anorexia, 6.0% vs 30.4%. No treatment related death was observed. Conclusions: The combination treatment of S-1 and CDDP met primary endpoint of OS, and was found to be effective and well tolerated in pts with AGC. Accordingly, this regimen can be regarded as one of first-line standard treatment for AGC.

No significant financial relationships to disclose.

Identification of four members of the Anopheles funestus (Diptera: Culicidae) group and their role in Plasmodium falciparum transmission in Bagamoyo coastal Tanzania

The role of Anopheles funestus group in malaria transmission was investigated in Bagamoyo coastal Tanzania, in the process of characterizing the area as a malaria vaccine testing site. Mosquitoes were sampled inside houses and multiplex PCR was used to identify 649 specimens. The following species were found: A. funestus s.s. (84.3%), A. leesoni (13.6%), A. rivulorum (1.5%) and A. parensis (0.6%). Multiplex PCR of 147 blood-fed specimens showed that over half (57.1%) of the identifiable blood meals were taken from human hosts, and human blood index in A. funestus and A. leesoni was 55% and 82% respectively. Plasmodium falciparum infection rate determined by nested PCR was 11% in A. funestus s.s. Although the abundance was low, 26 specimens of A. leesoni, two of A. rivolurum and one of A. parensis were found positive for P. falciparum. The presence of four A. funestus species in Tanzania emphasizes the relevance to define precisely their spatial and temporal distribution, specific behaviour, ecology and exact role in malaria transmission.

Developmental failure of the intra-articular ligaments in mice with absence of growth differentiation factor 5

OBJECTIVE

To show the phenotypic characteristics of the knee joints in brachypodism mice (bp mice), which carry a functional null mutation of the growth differentiation factor 5 (GDF5) gene, we investigated the adult and embryonic bp mice.

METHOD

Radiographic and macroscopic examinations of the knee joint of adult bp mice were performed. A histological examination of the knee joint of bp mice from E12.5 to E18.5 was also performed.

RESULTS

Radiographic and macroscopic examinations of the adult bp mice showed anterior dislocation, hypoplastic condyles, and absence of the intra-articular ligaments. Safranin O staining of knee joints of the embryonic bp mice showed severe hypoplasty of the chondroepiphyses and intra-articular ligaments at E16.5. There was no difference in the number and location of 5-bromo-2'-deoxyuridine (BrdU)-positive cells between wild-type and bp mice through E12.5 to E14.5. A terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) study showed excessive cell death of mesenchymal cells of the future knee joint in bp mice at E12.5 and E13.5.

CONCLUSION

bp mice exhibit developmental failure of the condyles and intra-articular ligament of the knee joints.

Fetal calf serum-free culture of Chinese hamster ovary cells employing fish serum

The effects of fish serum on cell growth and human granulocyte-macrophage colony-stimulating factor (hGM-CSF) production in an adhesion culture of Chinese hamster ovary (CHO) cells DR1000L4N were investigated and compared with those of fetal calf serum (FCS). Although fish serum did not stimulate the initial adhesion of CHO cells to culture dishes, it prompted cell growth after cell adhesion with FCS for 24 h. The cell density in the fish serum medium reached 75% that in the FCS medium. Fish serum promoted cell adhesion to and cell growth on collagen-coated dishes. The cell-specific production rate of hGM-CSF in the fish serum medium on collagen-coated dishes was almost the same as that in the FCS medium.

Effects of temperature on the immature development of the stone leek leafminer Liriomyza chinensis (Diptera: Agromyzidae)

The effect of nine constant temperatures (15, 17.5, 20, 22.5, 25, 27.5 30, 32.5, and 35 degrees C) on the development of the stone leek leafminer, Liriomyza chinensis (Kato), on Japanese bunching onion, Allium fistulosum L., was studied in the laboratory. Developmental times for immature stages were inversely proportional to temperature between 15 and 30 degrees C but increased at 32.5 degrees C. Total developmental times from egg to adult emergence decreased from 69.6 to 17.1 d for temperatures from 15 to 30 degrees C, with pupae requiring more time for development than the combined egg and larva stages. Both linear and nonlinear (Logan equation VI) models provided a reliable fit of development rates versus temperature for all immature stages. The lower developmental thresholds that were estimated from linear regression equations for the egg, first, second, and third instars, total larva, egg-larval, pupa, and total combined immature stages were 12.1, 10.6, 13.6, 8, 9.6, 11.3, 11.2, and 11.4 degrees C, respectively. The degree-day accumulation was calculated as 312.5 DD for development from egg to adult emergence. By fitting the nonlinear models to the data, the upper and optimal temperatures for egg, larva, pupa, and total immature stages were calculated as 37.8 and 31.7, 34.9 and 30.1, 35.8 and 30.6, and 35.0 and 30.9 degrees C, respectively. These data are useful for predicting population dynamics of L. chinensis under field conditions and determining the maximum proportion of susceptible individuals for facilitating improved timing of application of control measures.

Thrombin induces striatal neurotoxicity depending on mitogen-activated protein kinase pathways in vivo

Intracerebral hemorrhage represents stroke characterized by formation and expansion of hematoma within brain parenchyma. Blood-derived factors released from hematoma are considered to be involved in poor prognosis of this disorder. We previously reported that thrombin, a blood-derived serine protease, induced cytotoxicity in the cerebral cortex and the striatum in organotypic slice cultures, which depended on mitogen-activated protein kinase (MAPK) pathways. Here we investigated the mechanisms of thrombin cytotoxicity in the striatum in vivo. Thrombin microinjected into the striatum of adult rats induced neuronal death and microglial activation around the injection site. Neuronal loss without any sign of nuclear fragmentation was observed as early as 4 h after thrombin injection, which was followed by gradual neuronal death exhibiting nuclear fragmentation. Thrombin-induced damage assessed at 72 h after injection was partially but significantly reduced by concomitant administration of inhibitors of MAPK pathways. Activation of extracellular signal-regulated kinase (ERK) and p38 MAPK in response to thrombin was verified by Western blot analysis. Moreover, phosphorylated ERK and p38 MAPK were localized prominently in reactive microglia, and inhibition of microglial activation by minocycline attenuated thrombin-induced damage, suggesting that reactive microglia were responsible for thrombin-induced neuronal death. Thus, MAPK pathways and microglial activation may serve as therapeutic targets of pathogenic conditions associated with hemorrhagic stroke.

Quantitative analysis of messenger RNA expression of matrix metalloproteinases (MMP-2 and MMP-9), tissue inhibitor-2 of matrix metalloproteinases (TIMP-2), and steroidogenic enzymes in bovine placentomes during gestation and postpartum

The relationship between the mRNA expression of proteolytic and steroidogenic enzymes in bovine placentomes was examined. Caruncle and cotyledon tissues were collected every 6 hr after spontaneous parturition until the fetal membranes were released. Based on the time of fetal membrane release after parturition, the specimens were classified as follows: (1) the early group, in which the fetal membranes were released within 6 hr after parturition; and (2) the late group, in which the fetal membranes were released 6-12 hr after parturition. The placentomes from a slaughterhouse were additionally collected as samples for the examination of enzymes during the gestation period. The mRNA expression of steroidogenic enzymes in the cotyledon was observed to be higher than that in caruncle tissues; however, the mRNA expression patterns of P450scc and StAR tended to be similar in both placental tissues. On the other hand, although the expression levels of TIMP-2 mRNA in both caruncle and cotyledon tissues were similar, during gestation and postpartum the expression levels of MMP-2 and MMP-9 mRNA were approximately 10 times higher in caruncle than in cotyledon tissue. Marked contrasting changes in mRNA expression patterns between pre- and postpartum periods were observed for MMP-2 and MMP-9 in caruncle tissues and for MMP-9 and TIMP-2 in cotyledon tissues. The present study provides the first evidence that MMP-2, MMP-9, and TIMP-2 mRNAs are expressed in bovine placentomes during the gestational and postpartum periods and suggests that these enzymes, in conjunction with steroidogenic enzymes, mediate fetal membrane detachment after parturition.

Gene silencing by the tRNA maturase tRNase ZL under the direction of small-guide RNA

We have been developing a unique system for the downregulation of a gene expression through cutting a specific mRNA by the long form of tRNA 3'-processing endoribonuclease (tRNase Z(L)) under the direction of small-guide RNA (sgRNA). However, the efficacy of this system and the involvement of tRNase Z(L) in the living cells were not clear. Here we show, by targeting the exogenous luciferase gene, that the efficacy of the sgRNA/tRNase Z(L) method can become comparable to that of the RNA interference technology and that the gene silencing is owing to tRNase Z(L) directed by sgRNA not owing to a simple antisense effect. We also show that tRNase Z(L) together with sgRNA can downregulate expression of the endogenous human genes Bcl-2 and glycogen synthase kinase-3beta by degrading their mRNAs in cell culture. Furthermore, we demonstrate that a gene expression in the livers of postnatal mice can be inhibited by an only seven-nucleotide sgRNA. These data suggest that sgRNA might be utilized as therapeutic agents to treat diseases such as cancers and AIDS.

Effect of NOS inhibitor on cytokine and COX2 expression in rat pulpitis

Various kinds of chemical mediators are synthesized in the course of pulpitis; thus, control of their production would assist in inducing a reduction in pulpal inflammation. We hypothesized that nitric oxide (NO) would be an important mediator of pulpal inflammation. Pulpal inflammation was induced by the application of LPS in rat incisor pulp, and inducible nitric oxide synthase (iNOS) expression was evaluated by reverse-transcription/polymerase chain-reaction and immunohistochemical staining. After LPS application, iNOS mRNA was first detected after 3 hrs, peaked at 6 hrs, and decreased thereafter. iNOS-positive cells were macrophages and neutrophils. An NOS inhibitor caused drastic decreases in the expression of pro-inflammatory cytokines and COX2 mRNA, which was highly induced in the LPS-induced pulpitis. These results indicate that NO synthesis is related to the initiation of mediator production, and that its down-regulation should contribute to the prevention of pro-inflammatory mediator synthesis.

Introduction of air in the anaerobic culture of Streptococcus pneumoniae serotype 23F induces the release of capsular polysaccharide from bacterial surface into the cultivation medium

AIM

An approach to increase Streptococcus pneumoniae capsular polysaccharide (CPS) in the culture medium during fed-batch cultivation in bioreactor.

METHODS AND RESULTS

Streptococcus pneumoniae serotype 23F was cultivated in a 5-l bioreactor with nitrogen-sparging and followed by addition of air in the stationary phase. The amount of CPS released in the supernatant progressively increased under air sparging. The profile of cellular viability and optical density was similar in both cultures. Immunoelectron microscopy showed that the amount of tightly cell-bound CPS was higher in bacteria cultivated under nitrogen than under air.

CONCLUSIONS

The stress caused by the addition of air at the stationary phase promoted a large increase of free CPS into the medium, as a consequence of the morphologic change in the capsule.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of air in the stationary phase of the culture would greatly simplify the subsequent downstream process, allowing CPS purification from the supernatant. The direct consequence of this process improvement is the reduction of vaccine production costs.