BCR/ABL and IL-3 activate Rap1 to stimulate the B-Raf/MEK/Erk and Akt signaling pathways and to regulate proliferation, apoptosis, and adhesion

The Ras family small GTPase Rap1 is activated by hematopoietic cytokines, such as interleukin (IL)-3, to induce beta1 integrin-mediated cell adhesion or by the BCR/ABL fusion tyrosine kinase to stimulate the MEK/Erk signaling pathway. Here, we demonstrate that the abrogation of Rap1 activation by SPA-1, a Rap1-specific GAP, inhibits activation of B-Raf, MEK, Erk, and Akt in a murine hematopoietic cell line, Ton.B210, stimulated with IL-3 or inducibly expressing BCR/ABL. Furthermore, Rap1 inactivation had an inhibitory effects on proliferation and survival of Ton.B210 cells, which were more remarkable when cells were stimulated by BCR/ABL than by IL-3. Induction of BCR/ABL expression increased adhesion of Ton.B210 cells to fibronectin in a manner at least partly dependent on its kinase activity, and Rap1 inhibition by SPA-1 partially inhibited BCR/ABL-induced adhesion of cells. Thus, IL-3- or BCR/ABL-induced activation of Rap1 may play important roles in regulation of cell proliferation and survival through activation of the B-Raf/MEK/Erk and Akt signaling pathways and in induction of integrin-mediated cell adhesion. Furthermore, as compared with IL-3, BCR/ABL is more dependent on Rap1-mediated signaling to induce cell proliferation and survival and, thus, Rap1 may represent an attractive target for novel therapies for leukemias caused by BCR/ABL.

Acute interstitial pneumonitis during chemotherapy for haematological malignancy

Fourteen adult patients with haematological malignancies (eight non-Hodgkin's lymphoma, one multiple myeloma, one chronic lymphocytic leukaemia, two acute lymphoblastic leukaemia and two acute myeloid leukaemia) developed acute interstitial pneumonitis (IP) during the course of chemotherapy. All patients manifested high fever over 38 degrees C, bilateral diffuse pulmonary interstitial infiltrates in the chest radiograph and severe hypoxia without hypercapnia in the arterial blood gas analysis. Pathogenic microorganisms were not detected in repeated examinations in any patient. Chemotherapy given included various anti-neoplastic drugs. Five patients had received granulocyte colony-stimulating factor (G-CSF) for chemotherapy-induced leucopenia. The onset was associated with an increase of leucocytes in 10 patients. All patients were treated with high dose steroid hormone and broad spectrum antibiotics with or without anti-fungal agents, and three required mechanical ventilation. Eleven patients quickly recovered from these situations, whereas three died. Autopsies were done in two patients and disclosed pneumocystis carinii (PC) pneumonitis in one and non-specific pulmonary congestive oedema and fibrosis in the other. In conclusion, IP of unknown cause could develop in patients with various haematological malignancies especially at the recovery phase of chemotherapy-induced leucopenia irrespective of the previous G-CSF administration. High dose steroid hormone should be used as therapy for such patients as soon as possible after exclusion of an infective aetiology.

The role of CD4 and CD8 cytotoxic T lymphocytes in the formation of viral vesicles

BACKGROUND

Herpetic vesicles caused by herpes simplex virus and varicella zoster virus, and hydroa vacciniforme (HV) are characterized by umbilicated vesicule formation.

OBJECTIVES

To understand the histogenesis of umbilicated vesicles in herpetic vesicles and HV, we demonstrated the presence of the virus-associated molecules in the lesions, and the pathogenic role of cytotoxic T-lymphocyte (CTL) immune responses.

METHODS

Phenotyping of infiltrating cells was carried out in biopsy specimens from herpes simplex, varicella, herpes zoster and HV, and compared with nonviral contact dermatitis. Viral antigens and Epstein-Barr virus-encoded small nuclear RNA (EBER) were detected by immunostaining and by in situ hybridization, respectively. Infiltrating CTLs expressing granzyme B and granulysin were determined by double immunostaining using confocal laser scanning microscopy.

RESULTS

In all herpetic vesicles, the corresponding viral antigens were observed in the cytopathic keratinocytes, and infiltration of lymphoid cells was present in the upper dermis and around the vessels. In all HV lesions studied, EBER+ T cells made up 5-10% of the dermal infiltrates and the dermal infiltrates contained almost no CD56 cells. CTLs expressing granzyme B and granulysin were present in both herpetic and HV lesions, in which they made up 10-30% of the total dermal infiltrates, whereas they comprised less than 5% of the infiltrates of biopsy specimens from nonviral contact dermatitis. Confocal laser microscopic examination demonstrated that both CD4+ and CD8+ T cells expressed granzyme B and granulysin.

CONCLUSIONS

CD4+ and/or CD8+ CTLs reactive to the virus-infected cells might be responsible for the histogenesis of herpetic and HV lesions characterized by umbilicated vesicles.

Filter-free wavelength converter using Sagnac loop and delayed interferometer

A filter-free fiber-XPM-based wavelength converter is proposed and experimentally demonstrated without conventional bandpass optical filters used to filter out the converted signal. The converter is constructed with a propagation-diversity Sagnac loop to separate a converted signal from a pump signal and a delayed interferometer to covert the XPM signal into intensity modulation. We show that 10-Gbit/s input signals are successfully converted to signals with allotted wavelengths by our proposed scheme.

dsRNA enhances eotaxin-3 production through interleukin-4 receptor upregulation in airway epithelial cells

The exacerbation of asthma during viral infections is mainly explained by neutrophils infiltrating into the airways. However, enhanced functions of eosinophils are also observed. The aim of this study was to reveal the mechanism of how eosinophils are activated during and after viral infection of the airways, using a model of viral infection. A synthetic double-stranded RNA, poly inosinic-cytidyric acid (poly(IC)), was transfected to a human airway epithelial cell line (BEAS-2B) and the primary bronchial epithelial cells, to mimic a viral infection. The production of chemokines from the cells was investigated. The transfection of poly(IC), alone, marginally affected the eotaxin-3 production of the cells. However, the transfection of poly(IC) prior to interleukin (IL)-4 stimulation enhanced eotaxin-3 production. Poly(IC) transfection increased mRNA and protein expressions of IL-4 receptor (R)alpha and IL-2Rgamma, components of the IL-4R. In BEAS-2B cells, IL-4-mediated phosphorylation of signal transducer and activator of transcription six was enhanced in poly(IC) transfected cells. This was reversed by the addition of anti-IL-4Ralpha antibody, suggesting the role of an increased number of IL-4 receptors in enhanced IL-4-induced eotaxin-3 production. Poly(IC)-induced upregulation of IL-4Ralpha was inhibited by treatment with cycloheximide or dexamethasone. In conclusion, these results suggest that viral airway infection may enhance interleukin-4-induced eotaxin-3 production through upregulation of the interleukin-4 receptor in airway epithelial cells.

Unloading-induced bone loss was suppressed in gold-thioglucose treated mice

Loss of mechanical stress causes bone loss. However, the mechanisms underlying the unloading-induced bone loss are largely unknown. Here, we examined the effects of gold-thioglucose (GTG) treatment, which destroys ventromedial hypothalamus (VMH), on unloading-induced bone loss. Unloading reduced bone volume in control (saline-treated) mice. Treatment with GTG-reduced bone mass and in these GTG-treated mice, unloading-induced reduction in bone mass levels was not observed. Unloading reduced the levels of bone formation rate (BFR) and mineral apposition rate (MAR). GTG treatment also reduced these parameters and under this condition, unloading did not further reduce the levels of BFR and MAR. Unloading increased the levels of osteoclast number (Oc.N/BS) and osteoclast surface (Oc.S/BS). GTG treatment did not alter the basal levels of these bone resorption parameters. In contrast to control, GTG treatment suppressed unloading-induced increase in the levels of Oc.N/BS and Oc.S/BS. Unloading reduced the levels of mRNA expression of the genes encoding osteocalcin, type I collagen and Cbfa1 in bone. In contrast, GTG treatment suppressed such unloading-induced reduction of mRNA expression. Unloading also enhanced the levels of fat mass in bone marrow and mRNA expression of the genes encoding PPARgamma2, C/EBPalpha, and C/EBPbeta in bone. In GTG-treated mice, unloading did not increase fat mass and the levels of fat-related mRNA expression. These results indicated that GTG treatment suppressed unloading-induced alteration in bone loss.

[Diaphragmatic eventration with paroxysmal supraventricular tachycardia; report of a case]

A 68-year-old man visited our hospital complaining of chest discomfort and palpitation and was hospitalized under the diagnosis of diaphragmatic eventration. The chest X-ray showed an elevated left hemidiaphragm including air bubbles. The chest computed tomography (CT) and magnetic resonance imaging (MRI) showed a very high position of the left hemidiaphragm and displacement of the abdominal organs into the left thoracic cavity. The Holter electrocardiogram showed paroxysmal supraventricular tachycardia. The procedure was performed under video-assisted thoracoscopic surgery with a minithoracotomy (7 cm) in the 8th intercostal space. The left diaphragm appeared loose and reduced in thickness, the diaphragm was incised and longitudinal plication 12cm in diameter was accomplished with a series of U-stitches with Teflon-felt. Furthermore, the suture line was reinforced by prolene mesh. Postoperative course was uneventful, and the chest symptom and arrhythmia were resolved immediately.

Intra- and intercontinental molecular variability of an Alu insertion in the 3' untranslated region of the LDLR gene

One-hundred three individuals from two Mongolian, two Siberian, and ten native American populations were studied in relation to a 340-bp sequence from an Alu insertion located in the 3' untranslated region of the LDLR gene. Seven haplotypes have been determined, and haplotype B1 was the most common, accounting for about half the sequences found. In general, diversity values are quite high, about 2.5 times higher than those found in other autosomal Alu sequences. Almost all (93%) of the variability occurs at the intrapopulation level, but the greatest among-group differentiation (6-8%) was found when we grouped in a single population all Native Americans plus Siberian Eskimos and Chukchi and compared them with Mongolians. This result is compatible with earlier mtDNA and Y-chromosome suggestions of a single origin for the first colonizers of the American continent. With this nuclear locus it was not possible to broadly distinguish between Central and South American natives. No evidence of selection or marked demographic changes was obtained with these data.

[Successful removal of an intrapulmonary aberrant needle under video-assisted thoracoscopic surgery; report of a case]

Intrapulmonary aberrant needles are rare in clinical practice. We report the successful removal of intrapulmonary aberrant needle. A 59-year-old man, though he was asymptomatic, was referred to our department after an abnormal shadow had been detected on a chest X-ray. Chest X-ray and chest computed tomography (CT) showed a foreign body suspected to be a metal artifact in the left upper lobe. It was diagnosed as an intrapulmonary aberrant needle and an operation under video-assisted thoracoscopic surgery was performed. Using perioperative fluoroscopy, we could confirm the location of the needle and remove it successfully. An intrapulmonary aberrant needle should be removed surgically, even if the patient is asymptomatic, due to the development of lung abscess or pyothorax and the risk containing harmful matter to health.

Apoptotic wing degeneration and formation of an altruism-regulating glandular appendage (gemma) in the ponerine ant Diacamma sp. from Japan (Hymenoptera, Formicidae, Ponerinae)

We here show an example of morphological novelties, which have evolved from insect wings into the specific structures controlling social behaviour in an ant species. Most ant colonies consist of winged queen(s) and wingless workers. In the queenless ponerine ant Diacamma sp. from Japan, however, all female workers have a pair of small thoracic appendages, called "gemmae", which are homologous to the forewings and acts as an organ regulating altruism expression. Most workers, whose gemmae are clipped off by other colony members, become nonreproductive helpers, while only a single individual with complete gemmae becomes functionally reproductive. We examined histologically the development of gemmae, and compared it with that of functional wings in males. Female larvae had well-developed wing discs for both fore- and hindwings. At pupation, however, the wing discs started to evaginate and later degenerate. The hindwing discs completely degenerated, while the degeneration of forewing discs was incomplete, leading to the formation of gemmae. The degeneration process involved apoptotic cell death as confirmed by TUNEL assay. In addition, glandular cells differentiated from the epithelial cells of the forewing buds after completion of pupation. The mechanism of developmental transition from wing to gemma can be regarded as an evolutionary gain of new function, which can be seen in insect appendages and vertebrate limbs.

Electron acceleration by a nonlinear wakefield generated by ultrashort (23-fs) high-peak-power laser pulses in plasma

We study experimentally the interaction of the shortest at present (23-fs) , relativistically intense (20-TW), tightly focused laser pulses with underdense plasma. MeV electrons constitute a two-temperature distribution due to different plasma wave-breaking processes at a plasma density of 10(20) cm(-3). These two groups of electrons are shown numerically to constitute bunches with very distinctive time durations.

Percutaneous radiofrequency ablation for unresectable large hepatic tumours during hepatic blood flow occlusion in four patients

AIM

To evaluate percutaneous radiofrequency (RF) ablation therapy for unresectable large hepatic tumours combined with regional interruption of hepatic blood flow, and to assess the safety and efficacy of this procedure.

MATERIALS AND METHODS

Four patients with hepatic tumours were enrolled in this study. Patients were treated by a single session of RF ablation during occlusion of both hepatic artery and hepatic vein. Tumour size ranged from 45-57 mm (mean 50.2 mm). Initial therapeutic efficacy was evaluated with helical computed tomography (CT) performed within 9 days after the treatment. CT or magnetic resonance imaging (MRI) was performed every 2-3 months thereafter.

RESULTS

The largest axis of coagulated lesions after the ablation was 50-60 mm (mean 56.5 mm) in diameter. The ablation therapy was considered complete in three patients; after a mean follow-up of 12.7 months, CT and MRI revealed complete destruction of their tumours. One patient required further treatment. No severe complications occurred.

CONCLUSION

Although further studies are needed, in this limited clinical trial a local ablation area exceeding 50 mm in diameter was achieved safely.

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.