Gene cloning, expression, and crystallization of a thermostable exo-inulinase from Geobacillus stearothermophilus KP1289

The gene ( inuA) encoding exo-inulinase (EC 3.2.1.80) was cloned from the thermophilic Geobacillus stearothermophilus ( Bacillus stearothermophilus) KP 1289 growing at between 41 degrees C and 69 degrees C. The inuA gene consisted of 1,482 bp encoding a protein of 493 amino acids. The deduced polypeptide of molecular mass ( M) 56,744 Da showed strong sequence similarity to Pseudomonas mucidolens exo-inulinase, Bacillus subtilis levanase, Paenibacillus polymyxa ( Bacillus polymyxa) fructosyltransferase, and so on, indicating that the enzyme belonged to glycosyl hydrolase family 32. The M of the purified exo-inulinase, expressed in Escherichia coli HB101, was estimated as approximately 54,000 Da by both SDS-PAGE and gel filtration. These results suggested that the active form of the enzyme is a monomer. The enzyme was active between 30 and 75 degrees C with an optimum at 60 degrees C. The properties were identical to those of the native enzyme. Additionally, for the first time for a prokaryotic GH32 protein, crystals of the recombinant enzyme were obtained.

MxA expression in patients with viral infection after allogeneic stem cell transplantation

Many patients suffer febrile diseases soon after allogeneic stem cell transplantation (SCT). Some of the symptoms of viral infections and acute GVHD are often difficult to distinguish. However, an accurate diagnosis is important since the treatments for these conditions are different. It is known that MxA protein is specifically induced in patients with several viral infections. We investigated the cytoplasmic expression of MxA in the peripheral blood mononuclear cells (PBMCs) of patients with fever after allogeneic SCT using a newly generated monoclonal antibody (KM1135) and flow cytometry. The level of MxA expression was significantly higher in patients diagnosed with viral infections (n=6, cytomegalovirus in three, Epstein-Barr virus in one, human herpesvirus-6 in one, adenovirus in one) than control individuals (n=9) (P<0.05, Mann-Whitney test). The level of MxA in patients with aGVHD (n=7) was identical to that in controls. The level of MxA correlated well with the amount of the cytomegalovirus antigen-positive cells in the presence of acute GVHD in two patients. The measurement of MxA is simple and useful in distinguishing viral disease from acute GVHD after allogeneic SCT.

Establishment of tendon-derived cell lines exhibiting pluripotent mesenchymal stem cell-like property

Development of the musculoskeletal system requires coordinated formation of distinct types of tissues, including bone, cartilage, muscle, and tendon. Compared to muscle, cartilage, and bone, cellular and molecular bases of tendon development have not been well understood due to the lack of tendon cell lines. The purpose of this study was to establish and characterize tendon cell lines. Three clonal tendon cell lines (TT-E4, TT-G11, and TT-D6) were established using transgenic mice harboring a temperature-sensitive mutant of SV40 large T antigen. Proliferation of these cells was significantly enhanced by treatment with bFGF and TGF-beta but not BMP2. Tendon phenotype-related genes such as those encoding scleraxis, Six1, EphA4, COMP, and type I collagen were expressed in these tendon cell clones. In addition to tendon phenotype-related genes, expression of osteopontin and Cbfal was observed. These clonal cell lines formed hard fibrous connective tissue when implanted onto chorioallantoic membrane in ovo. Furthermore, these cells also formed tendon-like tissues when they were implanted into defects made in patella tendon in mice. As these tendon cell lines also produced fibrocartilaginous tissues in tendon defect implantation experiments, mesenchymal stem cell properties were examined. Interestingly, these cells expressed genes related to osteogenic, chondrogenic, and adipogenic lineages at low levels when examined by RT-PCR. TT-G11 and TT-E4 cells differentiated into either osteoblasts or adipocytes, respectively, when they were cultured in cognate differentiation medium. These observations indicated that the established tendon cell line possesses mesenchymal stem cell-like properties, suggesting the existence of mesenchymal stem cell in tendon tissue.

Dexamethasone accelerates catabolism of leukotriene C4 in bronchial epithelial cells

Leukotriene (LT)C4, a potent chemical mediator in bronchial asthma, is metabolised to the less active LTE4 via LTD4 in two consecutive reactions catalysed by enzymes of the glutamyl transpeptidase and dipeptidase families. The activities of these catabolic enzymes may be influenced by glucocorticosteroids. This study was conducted to examine whether this inactivation of LTC4 is affected by dexamethasone (DEX) in transformed human bronchial epithelial cells and normal human bronchial epithelial cells. After incubation with DEX for 0-5 days, cells were resuspended in the presence of exogenous LTC4, and conversion of LTC4 to LTE4 was measured using high-performance liquid chromatography. Gamma-glutamyl transpeptidase (GGT) and GGT-related enzyme (GGTRE) messenger ribonucleic acid (mRNA) expression were examined using reverse transcriptase-polymerase chain reaction analysis, and GGT activity by enzyme assay. Conversion to LTE4 was accelerated by DEX pretreatment. GGTRE but not GGT mRNA expression was enhanced after incubation with DEX. The results indicate that dexamethasone transcriptionally upregulates the activity of gamma-glutamyl transpeptidase-related enzyme in human bronchial epithelial cells, which accelerates inactivation of leukotriene C4 via conversion to leukotriene E4. This is a novel mechanism of glucocorticosteroids in human bronchial epithelial cells.

Hedgehog signaling enhances core-binding factor a1 and receptor activator of nuclear factor-kappaB ligand (RANKL) gene expression in chondrocytes

Hedgehog signaling is considered to play a crucial role in chondrogenesis by regulation through a network of cytokine actions, which is not fully understood. We examined the effect of hedgehog signaling on the expression of core-binding factor a1 (Cbfa1), a critical transcription factor for the development of bone and cartilage. Primary chondrocytes prepared from the costal cartilage of newborn mice were treated with N-terminal fragment of recombinant murine sonic hedgehog (rmShh-N). Northern blot analysis indicated that Cbfa1 mRNA expression levels in the chondrocyte cultures were elevated by the treatment with rmShh-N. rmShh-N treatment enhanced 1.8 kb Cbfa1 promoter activity in chondrocytes, suggesting the presence of transcriptional control. As Cbfa1-binding site(s) have been located in the promoter of the receptor activator of nuclear factor-kappaB (RANK) ligand (RANKL) gene, we also examined RANKL expression. rmShh-N treatment upregulated RANKL and RANK mRNA expression levels in chondrocytes. Interestingly, RANKL suppressed the hedgehog enhancement of alkaline phosphatase activity in chondrocytes, suggesting the presence of a link between these signaling molecules. We conclude that hedgehog signaling activates Cbfa1 gene expression through its promoter in chondrocytes, and also activates and interacts with RANKL to maintain cartilage development.

Successful treatment of natural killer (NK) cell leukemia following a long-standing chronic active Epstein-Barr virus (CAEBV) infection with allogeneic bone marrow transplantation

The optimal treatment for natural killer (NK) cell leukemia after chronic active Epstein-Barr virus (CAEBV) infection has not been determined. A 15-year-old boy presented with NK cell leukemia following CAEBV infection for 5 years. The peripheral blood and BM had an increased number of CD3(-)CD56(+) large granular lymphocytes and a monoclonal integration of the EBV genome was detected. Chemotherapy was not sufficiently effective to control the disease. Allogeneic BMT from an HLA-identical sister was performed using a conditioning regimen consisting of total body irradiation, cyclophosphamide and thiotepa. The patient is disease-free with a perfect performance status 24 months after BMT. This is the first report to show that allogeneic BMT is potentially able to cure NK cell leukemia after CAEBV infection.

Intracerebroventricular administration of endothelin-1 impairs the habituation of rats to a novel environment in conjunction with brain serotonergic activation

The effects of i.c.v. administration of endothelin-1, at a low dose that does not produce abnormal behaviors such as barrel-rolling, on the emotional state of rats exposed to a novel environment were examined. Changes in the emotional state of rats with a novel environment were evaluated in terms of changes in exploratory activity in the hole-board apparatus, i.e., locomotor activity as well as the number and duration of rearing and head-dipping behaviors. Rats treated with i.c.v. saline showed marked exploratory behaviors immediately after exposure to the hole-board apparatus, but these exploratory behaviors decreased rapidly with time. On the other hand, the habituation of rats to a novel environment was prolonged by the i.c.v. administration of endothelin-1 (0.3 and 1 pmol). Furthermore, we also found that i.c.v. administration of endothelin-1 (1 pmol) significantly increased the serotonin (5-hydroxytryptamine) turnover in some brain regions, i.e., the cerebral cortex, hippocampus and midbrain, and the inhibition of brain 5-hydroxytryptamine synthesis by treatment with p-chlorophenylalanine (200 mg/kg/day, s.c.) for 2 days suppressed the behavioral effects of endothelin-1 (1 pmol, i.c.v.). In addition, i.c.v. administration of endothelin-1 (1 pmol) did not affect the spontaneous motor activity of rats. The present study demonstrated that i.c.v. administration of low doses of endothelin-1 impairs the habituation of rats to a novel environment in conjunction with brain 5-hydroxytryptaminergic activation. These results suggest that the central endothelin system may play a significant role in mediating emotionality.

Bone morphogenetic protein-2 enhances osterix gene expression in chondrocytes

Osterix is a recently identified zinc-finger-containing transcription factor, which is required for skeletogenesis as no bone formation was observed in osterix-deficient mice. Osterix was first cloned as a gene whose expression was enhanced by BMP in C2C12 cells. As BMP induces ectopic bone formation in vivo via a pathway reminiscent to endochondral bone formation, BMP may also regulate osterix gene expression in chondrocytes. However, no information was available regarding the BMP actions on osterix gene expression in chondrocytes. We therefore examined the effects of BMP-2 on osterix gene expression in chondrocytes in culture. RT-PCR analysis indicated that osterix mRNA was expressed in the primary cultures of chondrocytes derived from mouse rib cartilage. The treatment with BMP-2 enhanced the levels of osterix transcripts within 24 h and the enhancement was still observed at 48 h based on RT-PCR analysis. This BMP effect was specific to this cytokine, as TGF-beta did not alter osterix gene expression. BMP effects on the osterix mRNA levels were also confirmed by Northern blot analysis. The enhancing effect of BMP on osterix gene expression was observed in a dose-dependent manner starting at 200 ng/ml. The BMP enhancement of the osterix gene expression in chondrocytes was blocked in the presence of a protein synthesis inhibitor, cycloheximide, while it was still observed in the presence of 5,6-dichloro-1-beta D-ribofuranosylbenzimidazol (DRB) suggesting the involvement of post-transcriptional events, which require new protein synthesis. These results indicated that osterix gene is expressed in the primary cultures of chondrocytes and its expression is under the control of BMP-2.

Clinicopathologic evaluation after resection for ductal adenocarcinoma of the pancreas: a retrospective, single-institution experience

INTRODUCTION

Between April 1992 and December 2000, 167 patients with pancreatic carcinoma were evaluated and treated in our department. One hundred eight patients (64.7%) with pancreatic carcinoma underwent pancreatectomy. Of these patients, 94 had histologically proven ductal adenocarcinoma. The overall postoperative mortality rate was 3.2% (3 patients), and the morbidity rate was 35.1% (33 patients). The estimated 1-, 2-, 3-, and 5-year survival rates were 43.6%, 28.7%, 21.8%, and 12.9%, respectively. There were only six long-term survivors who survived >5 years after surgery. METHODOLOGY AND AIMS: Institutional experience with 94 consecutive patients with ductal adenocarcinoma who underwent pancreatectomy was reviewed to clarify the influence of 29 prognostic factors (5 host, 17 tumor, and 7 treatment factors). Special reference was made to determine whether these significant factors have an effect on long-term survival. Univariate and multivariate models were used to analyze the effect of prognostic factors on survival.

RESULTS

Univariate analysis indicated that blood loss, operative time, postoperative complications, histopathologic lymphatic and venous permeation, lymph node metastasis, conclusive stage, conclusive curability, resection margins, serosal invasion, size of tumor, retroperitoneal invasion, major arterial invasion, and mode of histologic infiltration were associated with significantly longer survival (p < 0.05). By Cox proportional hazards survival analysis, the most powerful predictors of outcome were venous permeation, lymph node metastasis, tumor diameter, and conclusive curability. The longest-term survivor had the most advanced stage (stage IV(b)) of disease and curability C. No long-term survivors had all of the good prognostic factors (according to multivariate analysis).

CONCLUSIONS

The prognosis after surgical resection of pancreatic carcinoma mostly depends on tumor factors. In this study, it was difficult to identify the determinants of long-term survival in patients with resectable tumors.

Defects in growth and bone metabolism in klotho mutant mice are resistant to GH treatment

Klotho mutant (kl/kl) mice exhibit growth retardation after weaning, and previous electron microscopic examination of GH-producing cells in pituitary glands revealed a reduction in GH granules. However, it has not been known whether growth retardation in klotho mutant mice is related to the loss of GH function. We therefore examined whether treatment with GH could rescue the retardation of growth. At the end of 3 weeks of treatment with human GH, the body weight of wild-type (WT) mice was increased. In contrast, body weight was not increased in klotho mutant mice even after the treatment with human GH. Another feature of klotho mutant mice is the presence of osteopetrosis in the epiphyses of long bones and vertebrae. Treatment with human GH increased trabecular bone volume in the epiphyseal region of WT tibiae. Interestingly, increase in trabecular bone volume by GH treatment was also observed in klotho mutant mice and, therefore, the phenotype of high bone volume in the klotho mice was further enhanced. These findings indicate that a GH receptor system in cancellous bones could operate in mutant mice. Thus, growth retardation in the klotho mutant mice is resistant against GH treatment even when these mice respond to GH treatment in terms of cancellous bone volume.

Growth of human T cell acute lymphoblastic leukemia lymphoblasts in NOD/SCID mouse fetal thymus organ culture

The in vitro proliferation of T cell acute lymphoblastic leukemia (T-ALL) cells in its entirety has not been well delineated because of a lack of an appropriate culture system that mimics the growth pattern in a living body. We applied a NOD/SCID mouse fetal thymus organ culture (FTOC) for leukemic cells from fresh (one case) and frozen (seven cases) bone marrow (BM) samples of children with T-ALL. Cell growth was observed in all seven samples in the culture, reaching a proliferational peak at 4 weeks, and it was calculated that the proliferation potential was 212-to 319-fold. The FTOC-derived T-ALL cells showed similarity to the original cells morphologically and immunophenotypically, still possessed clonalities and were able to regenerate overt leukemia in NOD/SCID mice. These FTOC-derived T-ALL cells differed from ordinary cell lines because they always need FTOC support. Thus, we established a new in vitro culture for T-ALL cells. A comparison of the original and FTOC-derived T-ALL cells revealed that the proportion of cells expressing IL-7R increased in all seven cases. Sorting and re-seeding of FTOC-derived IL-7R+ and IL-7R- cells into secondary FTOC resulted in a predominant generation of IL-7R+ cells from both fractions, while IL-7R- cells proliferated more potently than did IL-7R+ cells, suggesting that a pathway for the conversion of IL-7R- to IL-7R+ exists during the proliferation of T-ALL lymphoblasts. Addition of exogenous IL-7 or neutralization with anti-IL-7 antibody did not influence the growth pattern of T-ALL cells in FTOC. The current study provides a unique assay system for the exploration of the hierarchy within human T-lymphoid leukemic cells, and should facilitate the establishment of novel therapeutic modalities.

Successful treatment of relapsed blastic natural killer cell lymphoma with unrelated cord blood transplantation

The prognosis for blastic natural killer (NK) cell lymphoma is generally dismal. We report a patient who was successfully treated with unrelated cord blood transplantation (UCBT). A 15-year-old boy was diagnosed as having blastic NK cell lymphoma in the cervical lymph nodes. Autologous peripheral blood stem cell transplantation was performed on achieving a complete remission. However, the disease recurred in the bone marrow 6 months later. Chemotherapy induced a second remission and the patient received UCBT with a conditioning regimen consisting of total body irradiation, thiotepa and cyclophosphamide. Chronic GVHD of the lung occurred, but it was well controlled with steroids. At the time of writing, he remains in remission 18 months after UCBT with an excellent performance status. UCBT may be an option for patients with blastic NK cell lymphoma.

Neutrophil chemotaxis in bile duct-obstructed rats, and effect of internal biliary drainage

BACKGROUND/AIMS

Our previous studies demonstrated enhanced neutrophil chemotaxis in bile duct-ligated, obstructive jaundice rats. In the present study, we produced a reversible obstructive jaundice model in rats. The efficacy of the present model in producing sufficient bile flow blockade and subsequent internal biliary drainage was assessed. Furthermore, the effect of internal biliary drainage on neutrophil chemotaxis was evaluated.

METHODOLOGY

Bile duct was obstructed with a polyester tape attached with a stainless steel coil. Internal biliary drainage was performed by removing the tape. Rats were subjected to either 10 days' bile duct obstruction or 4 days' bile duct obstruction followed by 6 days' internal biliary drainage. Some animals underwent conventional bile duct ligation and dissection for 4 or 10 days. Neutrophil chemotaxis was evaluated with a modified Boyden method using interleukin-8 (recombinant rat Gro-beta) as chemoattractant.

RESULTS

The present technique produced sufficient obstructive jaundice as evidenced by increases in serum alanine aminotransferase and total bilirubin throughout the observation period, the values of which were insignificant with those induced by the conventional method. Internal biliary drainage effectively normalized these values. Similarly, neutrophil chemotaxis was enhanced with both procedures, and increased neutrophil chemotaxis was significantly decreased after drainage.

CONCLUSIONS

The present reversible obstructive jaundice method is as efficacious as the conventional method for producing obstructive jaundice, and internal biliary drainage could be readily available. With the present model, neutrophil overactivity in obstructive jaundice was effectively alleviated by internal biliary drainage. The result may support the role of preoperative biliary drainage in the prevention of postoperative septic complications.

Causes of titanium release from plate and screws implanted in rabbits

To investigate the mechanism behind the release of metal from titanium implants in vivo, bone-plate-screw sets consisting of pure titanium were implanted into the legs of rabbits for 48 weeks. Four groups of experiments containing control were conducted: (1) The tibia cut artificially was fixed by one set of bone plate and screws, (2) the same set was implanted separately into muscles in the leg, (3) the set was fixed on the tibia and immediately retrieved, and (4) no implantation was performed. The amounts of titanium in all tissues from knee to ankle were quantified using atomic adsorption spectrometry. The ratio of amounts of titanium detected in the groups (1), (2), and (3) was 100 : 10 : 43. No titanium was detected in the group (4). Causes of the release of titanium in the group (1) include that in the groups (2) and (3). Major causes of titanium release were surgical handling in implantation and wear and/or fretting during experimental-term for 48 weeks. Titanium was also released in the absence of wear. No morphological abnormality was observed around tissue of the implant by biopsy at post-operation week 48.

The effect of biliary decompression on antibiotic biliary excretion

BACKGROUND/AIMS

Raised biliary pressure may affect antibiotic biliary excretion. We evaluated whether biliary decompression for patients with biliary obstruction could improve antibiotic biliary excretion.

METHODOLOGY

Eight patients with common bile duct obstruction undergoing endoscopic nasobiliary drainage were evaluated. During endoscopic cannulation, biliary pressure above the obstruction and antibiotic concentrations in the bile and peripheral blood were determined 60 min after the intravenous antibiotic (panipenem) administration.

RESULTS

Biliary pressure was initially elevated above normal in all the patients, but normalized after biliary drainage for 5 to 7 days. At the initial endoscopic retrograde cholangiopancreatography, the aspirated bile contained low or undetectable levels of the antibiotic, but the mean bile panipenem concentration and the mean bile/plasma ratio of panipenem concentrations significantly improved after biliary decompression.

CONCLUSIONS

The results suggest an important role of biliary pressure in determining antibiotic transfer into the bile.

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) stimulates primitive and definitive erythropoiesis in mouse embryos expressing hGM-CSF receptors but not erythropoietin receptors

Although erythropoietin (EPO) and its receptor (EPOR) are crucial for the proliferation, survival, and terminal differentiation of erythroid progenitors, it remains to be elucidated whether EPOR-unique signaling is required for erythropoiesis. To address this issue, human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor (hGMR)-transgenic mice and heterozygous EPOR mutant mice were crossed by in vitro fertilization. In methylcellulose clonal culture of fetal liver (FL) cells of generated hGMR-expressing EPOR(-/-) embryos at embryonic day (E) 12.5 of gestation, hGM-CSF stimulated erythroid colony formation under serum-containing and serum-free conditions. Analysis of globin expression in individual erythrocyte-containing colonies formed from E12.5 FL cells showed that hGM-CSF supports primitive and definitive erythropoiesis even in EPOR(-/-) embryos. In comparison of activities between hGM-CSF and EPO in hGMR-expressing EPOR(+/+) embryos, the 2 substances supported the formation of similar numbers of erythroid colonies in clonal culture of E12.5 FL cells; enhanced adult, but not embryonic, globin synthesis; and induced increase of GATA-1 expression and decrease of erythroid Kruppel-like factor and cMyb expression in the FL cells. On the other hand, in E8.0 yolk sac erythropoiesis, both substances had a similar effect on erythroid colony formation, but hGM-CSF induced an increase of beta-major globin expression, while EPO did not. All together, the results of the present study demonstrated that hGM-CSF can stimulate the proliferation and differentiation of primitive and definitive erythroid cells independently of EPOR signal if they express hGMR, and the activity is comparable to that of EPO in definitive, but not primitive, erythropoiesis.

ik3-1/Cables is a substrate for cyclin-dependent kinase 3 (cdk 3)

p70ik3-1 (a 70-kDa protein) contains a cyclin box, and binds to p35cdk3 in vivo and in vitro [Matsuoka, M., Matsuura, Y., Semba, K. & Nishimoto, I. (2000) Biochem. Biophys. Res. Commun. 273, 442-447]. In spite of its structural similarity to cyclins, p70ik3-1 does not activate cyclin-dependent kinase 3 (cdk3)-mediated phosphorylation of pRb, histone H1, or the C-terminal domain of RNA polymerase II. Here, we report that Ser274 of p70ik3-1 is phosphorylated by cdk2 or cdk3 bound to cyclin A and to cyclin E in vitro. We also found that in COS7 cells in which cyclin E and cdk3 were ectopically overexpressed, the phosphorylation level of Ser274 in coexpressed p70ik3-1 is upregulated. We therefore conclude that p70ik3-1 is a substrate for cdk3-mediated phosphorylation.

Expression of G-CSF receptor on myeloid progenitors

Although granulocyte colony-stimulating factor (G-CSF) has been reported to act on cells of neutrophilic lineage, the expression of receptors for G-CSF (G-CSFR) on human hematopoietic progenitor cells has been unclear. We then analyzed the expression of G-CSFR on human bone marrow and G-CSF mobilized peripheral blood CD34+ cells, and examined the proliferation and differentiation capabilities of sorted CD34+ G-CSFR+ and CD34+ G-CSFR- cells using methylcellulose clonal culture. These results indicate that the expression of G-CSFR on CD34+ cells is restricted to myeloid progenitors, suggesting that the specific activity of G-CSF on myelopoiesis depends on the exclusive expression of its receptor on myeloid progenitors, and that the mobilization of various hematopoietic stem/progenitor cells is not a direct effect of G-CSF in humans.