Visualising the dynamics of live pancreatic microtumours self-organised through cell-in-cell invasion

Pancreatic ductal adenocarcinoma (PDAC) reportedly progresses very rapidly through the initial carcinogenesis stages including DNA damage and disordered cell death. However, such oncogenic mechanisms are largely studied through observational diagnostic methods, partly because of a lack of live in vitro tumour imaging techniques. Here we demonstrate a simple live-tumour in vitro imaging technique using micro-patterned plates (micro/nanoplates) that allows dynamic visualisation of PDAC microtumours. When PDAC cells were cultured on a micro/nanoplate overnight, the cells self-organised into non-spheroidal microtumours that were anchored to the micro/nanoplate through cell-in-cell invasion. This self-organisation was only efficiently induced in small-diameter rough microislands. Using a time-lapse imaging system, we found that PDAC microtumours actively stretched to catch dead cell debris via filo/lamellipoedia and suction, suggesting that they have a sophisticated survival strategy (analogous to that of starving animals), which implies a context for the development of possible therapies for PDACs. The simple tumour imaging system visualises a potential of PDAC cells, in which the aggressive tumour dynamics reminds us of the need to review traditional PDAC pathogenesis.

Anchorage-dependent multicellular aggregate formation induces a quiescent stem-like intractable phenotype in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal refractory cancers. Aggressive features in PDAC cells have been well studied, but those exhibited by a population of PDAC cells are largely unknown. We show here that coculture with epithelial-like feeder cells confers more malignant phenotypes upon PDAC cells forming anchorage-dependent multicellular aggregates (Ad-MCAs, a behavior of collective cells), in vitro. When CD44v3-10^high/CD44s^low PDAC cell lines, which exhibited an epithelial phenotype before the onset of epithelial-mesenchymal transition (EMT), were cocultured with a monolayer of HEK293T cells overnight, they formed Ad-MCAs on the feeder layer and acquired gemcitabine resistance. CD44v8-10 expression was dramatically increased and Ki-67 staining decreased, suggesting that PDAC cells forming Ad-MCAs acquired cancer stem cell (CSC)-like intractable properties. We found that highly downregulated genes in PDAC cells cocultured with HEK293T cells were significantly upregulated in malignant lesions from pancreatic cancer patients. Our work implies that PDAC cells forming Ad-MCAs partially return to a normal tissue gene profile before the onset of EMT. The collective cell behavior like Ad-MCA formation by PDAC cells may mimic critical events that occur in cancer cells at the very early phase of metastatic colonization.

Pancreatic cancer cells express CD44 variant 9 and multidrug resistance protein 1 during mitosis

Pancreatic cancer is one of the most lethal cancers with high metastatic potential and strong chemoresistance. Its intractable natures are attributed to high robustness in tumor cells for their survival. We demonstrate here that pancreatic cancer cells (PCCs) with an epithelial phenotype upregulate cell surface expression of CD44 variant 9 (CD44v9), an important cancer stem cell marker, during the mitotic phases of the cell cycle. Of five human CD44(+) PCC lines examined, three cell lines, PCI-24, PCI-43 and PCI-55, expressed E-cadherin and CD44 variants, suggesting that they have an epithelial phenotype. By contrast, PANC-1 and MIA PaCa-2 cells expressed vimentin and ZEB1, suggesting that they have a mesenchymal phenotype. PCCs with an epithelial phenotype upregulated cell surface expression of CD44v9 in prophase, metaphase, anaphase and telophase and downregulated CD44v9 expression in late-telophase, cytokinesis and interphase. Sorted CD44v9-negative PCI-55 cells resumed CD44v9 expression when they re-entered the mitotic stage. Interestingly, CD44v9(bright) mitotic cells expressed multidrug resistance protein 1 (MDR1) intracellularly. Upregulated expression of CD44v9 and MDR1 might contribute to the intractable nature of PCCs with high proliferative activity.

Anchorage-dependent multicellular aggregate formation induces CD44 high cancer stem cell-like ATL cells in an NF-κB- and vimentin-dependent manner

Adult T-cell leukemia/lymphoma (ATL) is an intractable T-cell malignancy accompanied by massive invasion of lymphoma cells into various tissues. We demonstrate here that ATL cells cultured on a layer of epithelial-like feeder cells form anchorage-dependent multicellular aggregates (Ad-MCAs) and that a fraction of MCA-forming ATL cells acquire CD44 high cancer stem cell-like phenotypes. ATL cells forming Ad-MCAs displayed extracellular microvesicles with enhanced expression of CD44v9 at cell synapses, augmented expression of multidrug resistance protein 1, and increased NF-κB activity. Blockade of the NF-κB pathway dramatically reduced Ad-MCA formation by ATL cells and the emergence of CD44 high ATL cells, but left a considerable number of ATL cells adhering to the feeder layer. Disruption of vimentin cytoskeleton by treatment with withaferin A, a natural steroidal lactone, suppressed not only the adhesion of ATL cells to the feeder layer but also subsequent Ad-MCA formation by ATL cells, suggesting the involvement of vimentin in anchoring ATL cells to the feeder layer. Ad-MCA formation by ATL cells on a layer of epithelial-like feeder cells may mimic critical events that occur in metastatic colonization.

MICA/B expression in macrophage foam cells infiltrating atherosclerotic plaques

Infiltrating macrophages accumulate in fatty streak lesions and transform into foam cells, leading to the formation of atherosclerotic plaques. Inflammatory mechanisms underlying the plaque formation mediated by NKG2D-positive lymphocytes such as CD8+ T cells, natural killer cells and natural killer T cells have been extensively investigated. Yet, the involvement of the NKG2D system itself remains poorly understood. Recent work in mouse models has shown that blockade of an NKG2D receptor-ligand interaction reduces plaque formation and suppresses inflammation in aortae. In this study, we conducted immunohistochemical analysis of NKG2D ligand expression in autopsy-derived aortic specimens. Foam cells expressing NKG2D ligands MICA/B were found in advanced atherosclerotic lesions accompanied by a large necrotic core or hemorrhage. Human monocyte-derived macrophages treated in vitro with acetylated low-density lipoproteins enhanced expression of MICA/B and scavenger receptor A, thus accounting for NKG2D ligand expression in foam cells infiltrating atherosclerotic plaques. Our results suggest that, as in mice, the NKG2D system might be involved in the development of atherosclerosis in humans.

Protective roles of epithelial cells in the survival of adult T-cell leukemia/lymphoma cells

Adult T-cell leukemia/lymphoma (ATL) is a highly invasive and intractable T-cell malignancy caused by human T-cell leukemia virus-1 infection. We demonstrate herein that normal tissue-derived epithelial cells (NECs) exert protective effects on the survival of leukemic cells, which may partially account for high resistance to antileukemic therapies in patients with ATL. Viral gene-silenced, ATL-derived cell lines (ATL cells) dramatically escaped from histone deacetylase inhibitor-induced apoptosis by direct co-culture with NECs. Adhesions to NECs suppressed p21(Cip1) expression and increased a proportion of resting G0/G1 phase cells in trichostatin A (TSA)-treated ATL cells. ATL cells adhering to NECs down-regulated CD25 expression and enhanced vimentin expression, suggesting that most ATL cells acquired a quiescent state by cell-cell interactions with NECs. ATL cells adhering to NECs displayed highly elevated expression of the cancer stem cell marker CD44. Blockade of CD44 signaling diminished the NEC-conferred resistance of ATL cells to TSA-induced apoptosis. Co-culture with NECs also suppressed the expression of NKG2D ligands on TSA-treated ATL cells, resulting in decreased natural killer cell-mediated cytotoxicity. Combined evidence suggests that interactions with normal epithelial cells augment the resistance of ATL cells to TSA-induced apoptosis and facilitate immune evasion by ATL cells.

Two novel NKG2D ligands of the mouse H60 family with differential expression patterns and binding affinities to NKG2D

H60, originally described as a dominant minor histocompatibility Ag, is an MHC class I-like molecule that serves as a ligand for the NKG2D receptor. In the present study, we identified two novel mouse chromosome 10-encoded NKG2D ligands structurally resembling H60. These ligands, which we named H60b and H60c, encode MHC class I-like molecules with two extracellular domains. Whereas H60b has a transmembrane region, H60c is a GPI-anchored protein. Recombinant soluble H60b and H60c proteins bound to NKG2D with affinities typical of cell-cell recognition receptors (K(d) = 310 nM for H60b and K(d) = 8.7 muM for H60c). Furthermore, expression of H60b or H60c rendered Ba/F3 cells susceptible to lysis by NK cells, thereby establishing H60b and H60c as functional ligands for NKG2D. H60b and H60c transcripts were detected only at low levels in tissues of healthy adult mice. Whereas H60b transcripts were detectable in various tissues, H60c transcripts were detected mainly in the skin. Infection of mouse embryonic fibroblasts with murine cytomegalovirus induced expression of H60b, but not H60c or the previously known H60 gene, indicating that transcriptional activation of the three types of H60 genes is differentially regulated. The present study adds two new members to the current list of NKG2D ligands.

Altered expression of apoptosis-related genes in osteocytes exposed to high-dose steroid hormones and hypoxic stress

OBJECTIVE

High-dose steroid hormones cause necrosis of the femoral head. Since steroid hormones function as blood coagulants, we hypothesized that ischemic hypoxia induced by steroid hormones is critical for apoptosis which occurs before necrosis of osteocytes.

METHODS

We performed an analysis of gene expression in the process of leading osteocytes to apoptosis, using a mouse cell line. Cultured osteocytes were loaded with hypoxic stress with or without exposure to steroid hormones, and the gene expression under these conditions was investigated using a cDNA array and real-time quantitative RT-PCR.

RESULTS

The proapoptotic p53 gene was downregulated under a hypoxic (1% O2) condition without exposure to steroid hormones. On the other hand, the expression of antiapoptotic Bcl-2 gene was increased by exposure to high-dose steroid hormones under a normoxic condition (20% O2). Interestingly, both proapoptotic (p53 and Bax) and antiapoptotic (Bcl-2 and MDM2)genes were downregulated in osteocytes treated with high-dose steroid hormones in the hypoxic environment.

CONCLUSIONS

These findings suggest that osteocytes exposed to high-dose steroid hormones appear to be more sensitive to apoptosis in the hypoxic environment than those without exposure to steroid hormones. This concept helps to understand the pathogenesis of idiopathic necrosis of the bone.

Short communication: expression of human endogenous retrovirus-R gene links to differentiation of squamous cells

To investigate the biological roles of human endogenous retrovirus-R (HERV-R) in vivo, we established transgenic rats carrying the full sequence of the viral genome with control of its own long terminal repeat promoter. The Env protein was expressed on the surface of the epidermis of fetal HERV-R transgenic rats on day 10 of gestation. The epidermal Env expression disappeared by day 18 of gestation. After day 18 of gestation, the Env protein was detected in the prickle layer of the esophageal epithelium of transgenic rats. Interestingly, it was not detected in the basal layer of the epithelium, and the expression in the granular layer was weaker than in the prickle layer. These findings suggest that expression of HERV-R is linked not only to the development but also to the differentiation of squamous cells. Next, we examined alterations in the expression of the HERV-R env gene in cultured human squamous cells after exposure to all-trans retinoic acids (ATRA). The env expression was increased by ATRA in a dose-dependent manner, while the expression of transglutaminase 1 (TGM1), a terminal marker for squamous differentiation, was decreased. TGM1 is expressed in the granular layer of the squamous epithelium, and ATRA suppresses the differentiation of cultured squamous cells. Thus, these in vitro data also suggest that HERV-R expression is regulated by a mechanism closely related to the differentiation of squamous cells. This study is the first to demonstrate the association of HERV-R expression and differentiation of squamous cells.

Role of neuronal interferon-gamma in the development of myelopathy in rats infected with human T-cell leukemia virus type 1

Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of not only adult T-cell leukemia but also HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Among the rat strains infected with HTLV-1, chronic progressive myelopathy, named HAM rat disease, occurs exclusively in WKAH rats. In the present study, we found that HTLV-1 infection induces interferon (IFN)-gamma production in the spinal cords of HAM-resistant strains but not in those of WKAH rats. Neurons were the major cells that produced IFN-gamma in HTLV-1-infected, HAM-resistant strains. Administration of IFN-gamma suppressed expression of pX, the gene critically involved in the onset of HAM rat disease, in an HTLV-1-immortalized rat T-cell line, indicating that IFN-gamma protects against the development of HAM rat disease. The inability of WKAH spinal cord neurons to produce IFN-gamma after infection appeared to stem from defects in signaling through the interleukin (IL)-12 receptor. Specifically, WKAH-derived spinal cord cells were unable to up-regulate the IL-12 receptor beta2 gene in response to IL-12 stimulation. We suggest that the failure of spinal cord neurons to produce IFN-gamma through the IL-12 pathway is involved in the development of HAM rat disease.

Chronic graft-versus-host disease-like autoimmune disorders spontaneously occurred in rats with neonatal thymus atrophy

We earlier reported that the human T cell leukemia virus type-1 pX gene transduced into rat thymic epithelial cells had an impact on biology of the cells. We report here that FW-pX rats born by mating of F344 transgenic rats expressing the pX gene without tissue specificity with nontransgenic Wistar rats developed disorders, including atrophy of the thymus, lymphocytopenia, and inflammatory cell infiltration into multiple organs, similar to events in chronic graft-vs.-host disease (GVHD). Vanishment of thymic epithelial cells especially in the cortex and marked depletion of CD4 CD8 double-positive thymocytes were evident in the neonatal thymus in these rats. The relative abundance of CD8 compared to CD4 T cells may be related to dominant infiltration of CD8 T cells into the affected organs. Additionally, adoptive transfer of FW-pX splenocytes could induce lymphocytic infiltration into sublethally irradiated wild-type syngeneic recipients. Analysis of the expression level of the Foxp3 gene in peripheral blood mononuclear cells revealed that the numbers of immunoregulatory T cells were less in FW-pX rats than in wild-type rats. The collective evidence suggested that the FW-pX rats spontaneously developed chronic GVHD-like autoimmune diseases, following abortive differentiation of T cells in the thymus in early days of the newborn. This rat model may shed light on the pathogenesis of chronic GVHD and also other systemic autoimmune diseases, the etiology of which is unknown.

Aberrant gene expression by CD25+CD4+ immunoregulatory T cells in autoimmune-prone rats carrying the human T cell leukemia virus type-I gene

Transgenic rats expressing the env-pX gene of human T cell leukemia virus type-I under the control of the viral long terminal repeat promoter (env-pX rats) developed systemic autoimmune diseases. Prior to disease manifestation, the immunosuppressive function of CD25(+)CD4(+) T (T-reg) cells was impaired in these rats. Since T cell differentiation appeared to be disordered in env-pX rats, we assumed that the impairment of T-reg cells might be caused by an abortive differentiation in the thymus. However, reciprocal bone marrow transfers between env-pX and wild-type rats revealed that direct effects of the transgene unrelated to the thymus framework induced the abnormality of T-reg cells. To identify molecular changes, comparative analyses were done between env-pX and wild-type T-reg cells. Expression of the Foxp3 gene and cell-surface markers supported a naive phenotype for env-pX T-reg cells. Array analyses of gene expression showed some interesting profiles, e.g. up-regulation of genes associated with the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways in env-pX T-reg cells. Additionally, expression of the suppressor of cytokine signaling (SOCS) family genes, which inhibit the JAK/STAT signals, was extremely low in env-pX T-reg cells. These findings suggest that the transgene may mediate the down-regulation of the SOCS family genes and that subsequent excess signals through the JAK/STAT pathways may result in the loss of function of env-pX T-reg cells. We suggest that investigation of the pathology of T-reg cells in our autoimmune-prone rat model may aid in understanding the roles of T-reg cells in human autoimmune diseases.

Bone marrow cells carrying the env-pX transgene play a role in the severity but not prolongation of arthritis in human T-cell leukaemia virus type-I transgenic rats: a possible role of articular tissues carrying the transgene in the prolongation of arthritis

Transgenic rats carrying the env-pX gene of human T-cell leukaemia virus type-I (env-pX rats) were immunized with type II collagen (CII), and chronological alterations of arthritis were compared with findings of collagen-induced arthritis (CIA) in wildtype Wistar-King-Aptekman-Hokudai (WKAH) rats. Arthritis induced by CII in env-pX rats was more severe and persisted longer than CIA in WKAH rats. To determine whether the phenomenon is caused mainly by the transgene-carrying lymphocytes or articular tissues, we immunized lethally irradiated env-pX and WKAH rats with reciprocal bone marrow cell (BMC) transplantation. A severe but transient arthritis was induced by CII in WKAH rats reconstituted by env-pX BMC (w/tB/CII rats). On the other hand, in env-pX rats reconstituted by WKAH BMC, arthritis persisted longer than in w/tB/CII rats, although the degree was less at an early phase after CII immunization. These findings suggest that articular tissues rather than the BMCs carrying the env-pX transgene play a role in the prolongation of arthritis in env-pX rats, although BMCs carrying the transgene are associated with the severity of arthritis. When inflammatory cytokines in synovial cells isolated from env-pX rats before they developed arthritis were examined, interleukin-6 (IL-6) was detected at a higher level than in synovial cells from WKAH rats, thus suggesting the critical role of IL-6 in env-pX arthritis.

Differential modulation of gene expression among rat tissues with warm ischemia

The aim of this study is to determine if warm ischemia after surgical extirpation impacts gene expression in tissue samples which will be used for cDNA array analysis. We investigated effects of warm ischemia on gene expression in lung, liver, kidney, and spleen of rats, chronologically, using an original cDNA array, real-time quantitative RT-PCR and immunohistochemistry. Although no visible alteration was found in RNA quality, cDNA array showed that expression of many genes was modulated by warm ischemia within 60 min in these tissues, 19.1% of the tested genes in lung, 11.0% in liver, 5.1% in kidney, and 16.2% in spleen. Quantitative RT-PCR revealed that warm ischemia significantly induced up-regulation of immediate early genes, c-fos, Egr-1, and c-jun, in lung, but not in liver. These findings suggest that genes may show tissue-dependent differential transcriptional response against warm ischemia. Tissue samples obtained from patients during surgery cannot completely escape effects of ischemia. In case of examination by cDNA array analysis, biologists should keep in mind that tissue samples come equipped with particular footprints.

Correlation between the levels of circulating adhesion molecules and PR3-ANCA in Wegener's granulomatosis

OBJECTIVE

The adhesion of neutrophils to the vascular endothelial cells appears to be important for the pathogenesis of vasculitis in Wegener's granulomatosis (WG). To determine the pathological significance of the neutrophil adhesion, we have examined and evaluated the relationships between the levels of adhesion molecules and proteinase-3 anti-neutrophil cytoplasmic antibodies (PR3-ANCA), and between the levels of TNF-alpha and disease activities in WG.

METHODS

sELAM-1 and sICAM-1 in sera from WG and healthy donors were detected by ELISA. SLex and LFA-1 on neutrophils were detected by flow cytometry.

RESULTS

The level of sICAM-1 was significantly higher in active WG than in inactive WG, tending to reflect individual disease activities. There was no difference in the level of sELAM-1 between WG patients and healthy donors.

CONCLUSION

Our study suggests that the adhesion of neutrophils to the vascular endothelium is significant for the pathogenesis of the vasculitis in WG.

An experimental study of the combined effect of radiotherapy and chemotherapy on head and neck squamous cell carcinoma cell line

OBJECTIVE

We have reported clinical effects of radiotherapy combined with either CDDP or CBDCA for head and neck cancer. In this study, we examined the combined effects of either CDDP or CBDCA with irradiation on the cell lines established from tongue SCC.

METHODS

The effects of irradiation, chemotherapy and the combined therapy on growth of the cell lines were examined respectively by the Alamar Blue assay.

RESULTS

The combination of 0.1 and 0.25 microg/ml CDDP with four times exposure to I Gy 60Co. which did not affect the growth of the cell lines, suppressed the growth synergistically. The combination of 1.0 and 2.0 ) microg/ml of CBDCA with four times exposure to 1 Gy 60Co showed synergistically suppressive effects on the growth of the cell lines.

CONCLUSION

It was suggested that the radiotherapy combined with the platium coordination complexes had a clinical usefulness in patients with head and neck cancer.

An autopsy case of familial idiopathic dilatation of bilateral atria

A 59-year-old male patient was followed up for congestive heart failure. Echo cardiogram showed no abnormal findings other than a remarkable dilatation of the bilateral atria. The coronary arteries and left ventricular contraction were normal. Left ventricular endomyocardial biopsy showed no significant abnormal findings. Further, we examined his siblings using dynamic magnetic resonance imaging (MRI) and found that they all also had dilated bilateral atria. After several hospitalizations, the proband died from cardiogenic shock. Pathological findings showed nonspecific change in bilateral atria and ventricles. This is a very rare case of familial idiopathic dilatation of bilateral atria.

[Decision-making style among hemodialysis patients]

The purpose of this descriptive study was to identify the decision-making style among the dialysis patients. Subjects were a Convenience sample of hemodialysis patients who agreed to participate this study. The data was collected through semi-structured interviews. The interviews were recorded on the tape and transcribed. Decision-making episodes were picked and interpreted by searchers. Data was analyzed based on the Inductive Theory Approach.

RESULT

Subject were 21 patients from 4 hospitals. The mean age was 51.1 and the mean duration after they started the hemodialysis was 9.1 years. The 16 decision-making styles were identified: accept, unvacillate, resignation, compromise, perseverance, challenge, self-activation, groupie, crisis-avoidance, withdrawal, prudent, reserve, escape, refusal, dogmatic, and entrust. These 16 decision-making styles were characterized by the reality oriented perception, the constructive regimes, the higher quality of social support. On the other hand, the passive decision-making styles were characterized by the distorted perception, the passive regimes, and the poor social support.

DISCUSSION

The reality orientation, energy, openness, values system were discussed as key factors which determined the decision-making style among hemodialysis patients. The nursing approach supporting the patients to make their decision were discussed.

[Components of decision-making among hemodialysis patients]

The purpose of this descriptive study was to identify the components of decision-making among the dialysis patients. Subjects were a Convenience sample of hemodialysis patients who agreed to participate this study. The data was collected through semi-structured interviews was recorded on the tape and transcribed. Decision-making episodes were picked and interpreted by researchers. Data was analysed based on the Grounded Theory Approach.

RESULT

Subject were 21 patients from 4 hospitals. The mean age was 51.1 and the mean duration after the hemodialysis was 9.1 years. The number of episode of decision-making were 136. Six components of decision-making were extracted such as <goal> <recognition of situation> <recognition of self> <choice> <planning> <evaluation>. The subject were making decision by examining and judging the situation and oneself, and then setting the goal. They were selecting situation and themselves. After all, the outcomes of decision-making were evaluating. Seven type of decision-making, erection type, reality-oriented type, elaborate type, dogmatic type, passive type, chance type, resistant type were extracted.

DISCUSSION

The factors which were related to the quality of decision-making were discussed such as the ability to examine the reality and control own wishes and needs, and the commitment for the decision-making. The nursing approach to facilitate the patients to make the decision were mentioned.

Adenosine mediates the antiarrhythmic effect of ischemic preconditioning in isolated rat hearts

Adenosine appears to mediate the preconditioning-induced reduction in infarct size in rabbits and dogs, but little is known about the role of adenosine in preconditioning-induced protection against ischemia-induced arrhythmias. We compared the effects of preconditioning induced by 2 cycles of 5 min of global ischemia and 2 cycles of 5 min of perfusion with either adenosine (100 mumol/L) or the adenosine A1-selective agonist 2-chloro-N6-cyclopentyladenosine (CCPA, 100 nmol/L) in protecting against ischemia-induced arrhythmias in Langendorff-perfused rat hearts. Preconditioning reduced the incidence of ventricular tachycardia (VT) from 100 to 58% and the incidence of sustained VT or ventricular fibrillation (VF) from 92 to 33%. Perfusion with adenosine reduced the incidence of VT from 100 to 55%, the incidence of VF from 67 to 9% and the incidence of sustained VT or VF from 92 to 9%. CCPA reduced the incidence of sustained VT or VF from 92 to 25%. These interventions provided a true reduction in the severity of arrhythmias, rather than merely a delay in the onset. Our results suggest that the stimulation of A1 receptor by adenosine is involved in triggering ischemic preconditioning-induced protection against ischemia-induced arrhythmias in rats.

Prognostic indicators of major cardiac events in patients with asymptomatic coronary artery disease

We investigated the role of myocardial ischemia in acute myocardial infarction and cardiac death in 253 patients with asymptomatic coronary disease (206 men, 47 women, mean age: 55 +/- 8 years). Patients were divided into two groups: those with angina pectoris with no history of myocardial infarction (AP group, 93 patients) and those with a history of myocardial infarction (MI group, 160 patients). We also examined the usefulness of exercise electrocardiographic and Holter electrocardiographic findings as prognostic indicators of cardiac events. After 24-hour Holter electrocardiograms were obtained in both groups, patients were assigned to subgroups with or without silent myocardial ischemia (SMI) based on the presence or absence of transient ST-segment depression. Prognostic indicators were evaluated by multiple regression analysis. Cardiac events occurred in 26 (10.3%) of 253 patients; in 6 patients these events were fatal. The incidence of cardiac events was significantly higher in the SMI group than in the non-SMI group (16.4% versus 5.6%, p < 0.05). SMI was identified as a significant prognostic indicator in the overall population (p = 0.0088), as were the number of diseased coronary arteries in the AP group (p = 0.0152), and SMI (p = 0.0022) in the MI group. There were 3 deaths related to cardiac events in each group. The mean time from onset of angina pectoris to death was 73 +/- 41 months compared with 33 +/- 43 months in the MI group. Our findings suggest that the severity of the coronary lesion and SMI were important predictors of major cardiac events, and that the mechanism of the onset of cardiac events was different in the AP and MI groups.

[Antineutrophil cytoplasmic antibody (C-ANCA) levels in relation to the treatment of Wegener's granulomatosis]

We assessed the clinical significance of cANCA in relation to the diagnosis and follow-up of Wegener's granulomatosis patients using NephroScholor C-ANC, the ELISA kit for the detection of cANCA. The NephroScholor C-ANC test for cANCA was revealed to be useful for the diagnosis of Wegener's granulomatosis, but slightly less sensitive than the indirect immunofluorescence assay using human neutrophils, which has been in widespread use for the detection of ANCAs. With NephroScholor C-ANC, the cANCA titer can be estimated conveniently and expressed quantitatively. When conventional immunosuppressive therapy with prednisolone and cyclophosphamide was applied, the patients' symptoms subsided as the cANCA titer decreased, and thus it also seemed useful for the follow-up of Wegener's granulomatosis patients. However, a rising ANCA titer during the course of the disease was not always correlated with the occurrence of a relapse as previously reported. Based on these findings, it is not recommended that treatment be changed immediately because of elevation of the ANCA titer alone, and it never seemed too late to increase immunosuppressive therapy, even after a clinical exacerbation was observed. Several treatments other than the conventional immunosuppressive therapy have often been applied for our patients, especially in the limited type of this disease, and these treatments, including sulfamethoxazole-trimethoprim alone, low-dose prednisolone alone, and cyclophosphamide alone, have often been useful. We conclude that the choice of therapy must depend on the severity or the condition of the individual patient, and this therapeutic policy should reduce unnecessary side effects of potentially toxic drugs.

Vasoactive intestinal peptide induces differentiation and MAP kinase activation in PC12h cells

Vasoactive intestinal peptide (VIP), a neuropeptide coupled with adenylate cyclase, was found to induce neurite extension of PC12h cells. Neurites appeared within 1 h after addition of VIP and extended for at least 24 h. The half-maximal concentration for the effect of VIP was 50 nM. In addition to the morphological change, VIP induced expression of VGF protein, a neuron-specific protein associated with neuronal differentiation. Western blotting with anti-phosphotyrosine antibody showed that VIP stimulated tyrosine phosphorylation of two proteins of 42 and 44 kDa, which may be two isoforms of MAP kinase, erk1 and erk2. Activation of MAP kinases was confirmed by ion-exchange chromatography on a Mono Q column, from which VIP-induced kinase activity was co-eluted with MAP kinase-immunoreactivity. Tyrosine-phosphorylation of MAP kinases was also stimulated by forskolin or dibutyryl cAMP, indicating that activation of MAP kinases by VIP might be mediated by cAMP. These results suggest that VIP-induced differentiation of PC12 cells is associated with cAMP-dependent activation of MAP kinases.

The signal transduction pathway for VGF expression due to NGF is different from that due to bFGF in PC12h cell

Using a polyclonal antibody against VGF, we examined the effects of various agents for its expression in PC12h cells. The results obtained were follows; 1) Basic fibroblast growth factor (bFGF), forskolin, dibutyryl cyclic AMP (dbcAMP), and nerve growth factor (NGF) induced the VGF protein. 2) The induction of VGF protein by NGF was inhibited by methylthioadenosine (MTA), but its induction by bFGF was not. 3) The induction of VGF protein by NGF was blocked by staurosporine, but its induction by bFGF was not. These findings suggest that the induction of VGF by NGF is distinct from that by bFGF in terms of sensitivities to MTA and staurosporine.

Desmoplastic fibroma of bone

We present a rare case of benign intraosseous desmoplastic fibroma, occurring in the tibial bone of a 48-year-old woman. The plain film features consist of a lytic, expansile lesion, in the metaphysis and epiphysis of the bone. We present a case involving the long bone in which the correct diagnosis was suggested by CT and MRI. The appearance of the lesion on CT and MR is described.

Genetic analysis of functional differences among distinct ferredoxins in Rhodobacter capsulatus

Rhodobacter capsulatus has been known to possess two ferredoxins (I and II) with distinct physicochemical and structural properties: ferredoxin I is a 2[4Fe-4S] type and the other is a [3Fe-4S] [4Fe-4S] type. To analyze their possible functional differences, their genes (fdxN and fdxA) were cloned, sequenced, and subjected to interposon mutagenesis experiments. The former gene was adjacent to a gene encoding a chloroplast-type [2Fe-2S] ferredoxin (fdxC). Mutants with inactivated fdxN and/or fdxC were obtained, and they showed virtually no growth under nitrogen-fixing conditions. Complementation experiments confirmed that both fdxN and fdxC were required for nitrogen fixation. On the other hand, we have not been able to disrupt fdxA under the screening conditions surveyed, including conditions that do not require nitrogenase activity for growth, suggesting that ferredoxin II could have an unknown essential role(s). These indicate functional differences among multiple ferredoxins in one bacterium other than in cyanobacterial heterocysts and indispensability of certain ferredoxins in nitrogen fixation other than Rhizobium meliloti FdxN.

Lumbar degenerative kyphosis. Clinical, radiological and epidemiological studies

We suggest that lumbar degenerative kyphosis be included as one of the abnormal sagittal curvatures in which a kyphosis or a marked loss of lordosis is seen in the lumbar spine, caused by degenerative changes in middle-aged and elderly. One hundred and five consecutive patients were investigated, most of whom complained of low-back pain, often with a long history. They all walked in a forward bending posture, either all the time or only when exhausted. In roentgenograms, most cases showed a marked loss of the sacral inclination, as well as multiple disc narrowing and/or vertebral wedging in the lumbar region. These subjects showed a definite weakness of the lumbar extensors compared to the flexors, and therefore a reversed ratio of extensors/flexors muscle power compared with normal controls and other types of spinal curvatures. Weakness of the lumbar extensors was clearly shown by isokinetic measurement and a marked atrophy of these muscles with fatty infiltration was demonstrated by CT scanning.

New modified activated partial thromboplastin time and prothrombin time methods using a synthetic chromogenic substrate in combination with diazotization

A chromogenic substrate, H-D-Phe-Pip-Arg-pNA (S-2238) is a highly specific substrate to thrombin and releases p-nitroaniline (pNA) by the action of thrombin. We describe new modified APTT and PT methods using S-2238 in combination with the diazotization of pNA. In the modified APTT method, 100 microliter citrated plasma (diluted to 10-fold), 90 microliter 1 mM S-2238, 100 microliter 20 mM CaCl2 and 100 microliter Actin were mixed in an ice-bath, then incubated for 8 min at 37 degrees C. The reaction was stopped, and the generated pNA was diazotized by adding the following solutions sequentially: 975 microliter 0.04% sodium nitrite, 975 microliter 0.3% ammonium sulfamate and 975 microliter 0.07% N-(l-naphthyl)-ethylenediamine dihydrochloride. Diazotization changed pNA from yellow to pink. Then, absorbance at 545 nm was read, and values were expressed as thrombin units/ml plasma. In the modified PT method, 100 microliter citrated plasma (diluted to 20-fold), 90 microliter 1 mM S-2238 and 200 microliter tissue thromboplastin-C solution were mixed and processed as above. Correlations of the present modified APTT and APTT methods, and of modified PT and PT methods were significant (r = 0.426, p less than 0.01 and r = 0.561, p less than 0.01, respectively).

[Synovial osteochondromatosis of the metatarsophalangeal joint of the great toe]

Synovial osteochondromatosis is an uncommon lesion in the metatarsophalangeal joint of the great toe. The condition is usually monoarticular, involving a large joint. Common locations include the knee, elbow, shoulder, hip and ankle. The histopathology is one of apparent cartilaginous bodies. Since these cartilage cells often display nuclear atypism, an accurate diagnosis is essential to avoid the erroneous diagnosis of chondrosarcoma. A case of synovial osteochondromatosis as it occurs in the metatarsophalangeal joint is presented, and this condition is discussed with a review of the literature.

Phosphorylation of D-glucosamine by rat liver glucokinase

D-Glucosamine was found to be phosphorylated by a rat liver extract in the presence of a high concentration of glucose, which was formerly believed to be a strong competitive inhibitor of this reaction. Results suggested that glucosamine may be phosphorylated by high Km hexokinase, i.e. glucokinase [EC 2.7.1.2]. The enzyme involved was separated from specific N-acetyl-D-glucosamine kinase [EC 2.7.1.59]. The phosphorylation was not inhibited by a physiological level of glucose or glucose 6-phosphate, which strongly inhibited low Km hexokinase. The apparent Km of glucokinase for glucosamine was estimated as 8 mM, which is ten times that of low Km hexokinase.