The structure and function of the cemento-dentinal junction in human teeth

The structure and function of the cemento-dentinal junction were studied in human molars by light and electron microscopy. The cemento-dentinal junction was an approximately 1-3-micron-thick layer full of proteoglycans with mucopolysaccharides but containing fewer collagen fibrils than the root dentin and cementum. In places, cemental fibrils crossed the cemento-dentinal junction. These fibrils appeared to intermingle with dentinal fibrils. By enzymatic treatment of decalcified specimen with hyaluronidase and trypsin, the cemento-dentinal junction decreased or lost staining affinity to toluidine blue. Prolonged treatment caused the separation of cementum from the root dentin during routine histological processes. These data suggest that the adhesion of proteoglycans is more important than the intermingling of dentinal and cemental fibrils for the cemento-dentinal attachment.

Severe impairment of B cell function in lpr/lpr mice expressing transgenic Fas selectively on B cells

Transgenic lpr/lpr mice expressing functional Fas selectively on B cells were produced in an attempt to elucidate the role of Fas on B cells in the regulation of autoantibody production. The homozygous lpr/lpr mice carrying the transgene did not produce anti-double-stranded DNA antibodies throughout their lives, whereas the development of abnormal lpr T cells (double negative, B220(+)) was not suppressed. Further analyses, however, revealed that the expression of the transgenic Fas on B cells of lpr/lpr homozygous mice resulted in severe impairment of the B cell function. The defect was characterized by a decrease in the number of mature peripheral B cells, a reduction in the serum Ig level and the total failure of B cells to mount antibody responses to stimulations of T-dependent as well as T-independent antigens. Such a defect was prominent only when the transgene was expressed on the lpr/lpr homozygous background. On the contrary, B cells of the transgenic lpr/lpr mice were shown to be capable of producing Ig when stimulated with anti-CD40 in the presence of IL-4 and IL-5. Furthermore, lpr/lpr T cells showed enhanced non-specific cytolytic activity. These observations suggested that the observed B cell defect was probably attributable to the destruction of activated B cells expressing transgenic Fas by aggressive lpr/lpr T cells.

Malignancies of natural killer (NK) cell precursor: myeloid/NK cell precursor acute leukemia and blastic NK cell lymphoma/leukemia

Malignant hematolymphoid disorders arising from natural killer (NK) cells have become widely recognized in the past decade. Recently, we as well as others have drawn attention to some neoplasms of conceivable NK cell precursor origin that might represent two distinct entities, i.e. myeloid/NK cell precursor acute leukemia and blastic NK cell lymphoma/leukemia. Both of these diseases were characterized by remarkable extramedullary involvement and lymphoblastoid morphology, although the sites of involvement differed. Myeloid/NK cell precursor acute leukemia exhibited more frequent involvement of bone marrow (BM) and lymph nodes, whereas blastic NK cell lymphoma/leukemia affected extranodal sites, mainly the skin/subcutis. Tumor cells of these two diseases shared the CD16-, CD56+ and CD57- phenotype, but differed in other phenotypic profiles. Indeed, myeloid/NK cell precursor acute leukemia was immunophenotypically characterized by the expression of CD34 and blastic NK cell lymphoma/leukemia by that of CD4. On the theoretical level in the NK cell differentiation pathway, myeloid/NK cell precursor acute leukemia might be derived from a myeloid antigen-positive precursor preceding a NK cell committed precursor as a conceivable counterpart of blastic NK cell lymphoma/leukemia. Most cases with either disease lacked cytotoxic activities or molecules, a finding which seems to support their precursor origin. Notably, Epstein Barr virus (EBV) was negative in all cases, which contrasted with its high level associated with mature NK cell malignancies. Chemotherapy for acute myeloid leukemia was generally effective for myeloid/NK cell precursor acute leukemia, while the regimen for lymphoid malignancy was effective for blastic NK cell lymphoma/leukemia. These data suggests that each of these two diseases constitutes a distinct entity, which is also different from mature NK cell malignancies.

Ellis-van Creveld syndrome: craniofacial morphology and multidisciplinary treatment

OBJECTIVE

The craniofacial morphology and multidisciplinary treatment of a patient with Ellis-van Creveld Syndrome are presented.

PATIENT

The patient presented is female. Her treatment began at the age of 10 years 6 months. She exhibited small stature with acromelic shortening of the extremities, postaxial syndactyly, and dysplastic nails. In the oral region, hyperplastic frena, absent anterior teeth, and small barrel-shaped teeth were noted.

SETTING AND INTERVENTION

The patient was treated at the University Hospital, Faculty of Dentistry, of the Tokyo Medical and Dental University. The treatment was divided into three stages: growth observation during which the patient wore acrylic plates with artificial anterior teeth; surgical-orthodontic treatment with sagittal split ramus osteotomy; and prosthodontic treatment with removable partial dentures.

MAIN OUTCOME MEASURES

Cephalometric analyses were performed to evaluate the changes in craniofacial morphology with growth during treatment.

RESULTS

Characteristic craniofacial morphology included a small posterior cranial base, small maxilla, and a large mandible with an increased gonial angle. Maxillo-mandibular relation was skeletal class III, and skeletal open bite was found. The skeletal class III relationship was progressive with growth. The patient was satisfied by the results of the multidisciplinary treatment.

CONCLUSION

The craniofacial morphology of the patient demonstrated disturbed growth of the cartilage bones. An acceptable result was obtained through combined surgical-orthodontic-prosthodontic treatment.

[Primary lung cancer (adenocarcinoma) associated with cardiac sarcoidosis]

A 56-year-old woman who had been given oral prednisolone for iridocyclitis by an ophthalmologist received a diagnosis of pulmonary sarcoidosis on the basis of transbronchial lung biopsy findings, and began receiving therapy at our hospital on an outpatient basis. Chest X-ray films disclosed hilar lymphadenopathy in both lungs. In addition, Holter electrocardiograms detected ventricular premature beat (Lown 4B) and echocardiograms detected reduced left ventricular wall motion with dilatation of the left ventricular chamber. Cardiac sarcoidosis developed in the patient. She was admitted to our hospital because of shortness of breath on exertion. Chest X-ray films on admission disclosed a large nodular heterogeneous mass in the right upper lobe. Histologically, transbronchial lung biopsy specimens of the mass disclosed an adenocarcinoma. Although lung cancer and sarcoidosis are common, their coexistence in the same patient is not. Furthermore, the coexistence of lung cancer with cardiac sarcoidosis, as in this case, is very rare.

A new preconditioning regimen with melphalan, busulphan and total body irradiation followed by low-dose immunosuppressant in allogeneic haemopoietic stem cell transplantation

Twenty adult patients with high-risk leukaemia underwent allogeneic haemopoietic stem cell transplantation after melphalan, busulphan and total body irradiation followed by short-term methotrexate and low-dose cyclosporine or tacrolimus. Three patients developed veno-occlusive disease and no patient developed renal dysfunction. Seven patients experienced grade II-IV acute graft-versus-host disease (aGVHD) and five patients experienced grade III-IV. The 3-year probabilities of relapse and leukaemia-free survival were 22 +/- 11% (95% confidence interval) and 50 +/- 11%, respectively. These data suggest that this preconditioning regimen followed by a low-dose immunosuppressant provided a more anti-leukaemic effect without increased regimen-related toxicity and aGVHD.

Regulation of cellular retinol-binding protein type II gene expression by arachidonic acid analogue and 9-cis retinoic acid in caco-2 cells

We previously showed that unsaturated fatty acids induced gene expression of cellular retinol-binding protein type II (CRBPII) in rat jejunum [Suruga, K., Suzuki, R., Goda, T. and Takase, S. (1995) J. Nutr. 125, 2039-2044]. In the present study, we investigated this induction mechanism(s) using the human intestinal Caco-2 cell line. The postconfluent mature Caco-2 cells were maintained in serum-free medium containing arachidonic acid or its analogue, 5,8,11, 14-eicosatetraynoic acid (ETYA). Northern blot analysis showed that these compounds induced CRBPII mRNA levels to rise and that this induction was more effective when combined with 9-cis retinoic acid. This effect was independent of cycloheximide and inhibited by actinomycin D. Nuclear run-on assays confirmed that the ETYA and 9-cis retinoic acid-induced increase of CRBPII mRNA levels was due to an increased rate of transcription of its gene. In Caco-2 cells, the transcripts of peroxisome proliferator-activated receptor alpha (PPARalpha) and retinoid X receptor alpha (RXRalpha), which were activated by their ligands ETYA and 9-cis retinoic acid, respectively, were coexpressed. The gel shift study using rat CRBPII gene nuclear receptor response elements (RXRE, RE2, RE3) revealed that several forms of nuclear proteins from Caco-2 cells specifically bound to these elements. Some of these protein/DNA complexes reacted to both anti-RXRalpha and anti-PPAR antibodies. In addition, in-vitro synthesized RXRalpha and PPARalpha cooperatively bound to these elements as a heterodimer and these binding activities were enhanced by addition of ETYA or arachidonic acid but not by addition of 9-cis retinoic acid. These studies suggest that fatty acid or its analogue may regulate CRBPII gene expression through PPAR/RXR heterodimer bound to the nuclear receptor response element(s) of the CRBPII genes.

Time course of activated coagulation time at various sites during continuous haemodiafiltration using nafamostat mesilate

OBJECTIVE

To determine the adequate site of activated coagulation time (ACT) measurement during continuous haemodiafiltration (CHDF) using nafamostat mesilate.

DESIGN

Prospective, consecutive, clinical study.

SETTING

An intensive care unit of a general hospital.

PATIENTS

Ten patients with acute organ failure including kidney, lung and liver, caused by sepsis after major surgery.

INTERVENTIONS

A CHDF circuit with a haemofilter made of polymethylmethacrylate membrane was primed with 50 mg nafamostat in 500 ml saline, and was started at a circuit flow rate of 100 ml/min. Continuous injection of 0.5 mg/kg per h nafamostat, 700 ml/h of dialysis fluid and 1000 ml/h of filtrate fluid was set.

MEASUREMENTS AND RESULTS

The circuit pressure at the inlet and outlet of the circuit were monitored, and ACT was measured every 2 h at the site of nafamostat injection, outlet, patient's artery and inlet until 24 h. A value of standard deviation of ACT at each site was regarded as the variation value of ACT. The circuit pressure did not change significantly. The ACT did not change significantly at any measurement site. The variation value of ACT at the inlet of the circuit was significantly lower than that at the site of nafamostat injection.

CONCLUSIONS

The ACT value at the inlet of the circuit may be adequate to monitor anticoagulation during CHDF using nafamostat.

Mouse popliteal lymph node assay for assessment of allergic and autoimmunity-inducing potentials of low-molecular-weight drugs

In the present collaborative study, popliteal lymph node (PLN) responses to penicillin G (an allergenic chemical), D-penicillamine (an autoimmunity-inducing chemical), and barbital (a negative reference chemical) were investigated in three different mouse strains by ten pharmaceutical companies. Two inbred mouse strains (BALB/c and A/J) and one outbred strain (ICR) were subcutaneously injected with saline solutions containing penicillin G (1.25, 2.5 and 5 mg/mouse), D-penicillamine (0.5, 1 and 2 mg/mouse), or barbital (2 mg/mouse) into one hind footpad and saline only was injected into the contralateral footpad. PLN cellularity indices were determined on day 7. In the three strains tested, the penicillin G and D-penicillamine injections resulted in approximately dose-dependent responses. In contrast, barbital failed to generate a significant PLN reaction. In the typical data from one of the participating laboratories, the PLN responses of A/J, BALB/c, and ICR to penicillin G were high, intermediate and low, respectively, while their PLN responses to D-penicillamine were all high. Some variation in PLN cellularity indices was observed among the participating laboratories, but reproducibility of the popliteal lymph node assay (PLNA) evaluation was partly confirmed. Although the appropriate selection of mouse strains and drug dosage levels has to be considered, these results suggest that the PLNA may be an appropriate screening system for prediction of the allergic or autoimmunity-inducing potentials of low-molecular-weight drugs.

Hodgkin's disease expressing follicular dendritic cell marker CD21 without any other B-cell marker: a clinicopathologic study of nine cases

Reed-Sternberg (RS) and Hodgkin's (H) cells are considered to be the neoplastic cells in Hodgkin's disease (HD). Although most data suggest their lymphoid origin, the nature of these cells still remains a subject of controversy. Recently, a number of RS cells have been found to express an antigen that is also present on follicular dendritic cells (FDCs), asserting FDCs as the possible progenitor cells of H-RS cells. This prompted us to investigate whether these CD21-positive cases had distinct clinicopathologic characteristics. In a series of 94 examined cases of HD, we identified 9 CD21-positive ones (4 of 37 cases of nodular sclerosis, 1 of 41 mixed cellularity, and 4 of 12 lymphocyte depletion HD) without any other B-cell marker on paraffin sections. The patients varied in age from 16 to 82 years (median, 50 years) and included six men and three women. They had superficial or mesenteric lymphadenopathy without hepatosplenomegaly. Peripheral blood leukocytosis was seen in three patients. The clinical course was indolent, and all patients but one achieved an initial complete response with HD-based treatment regimens, although three of them relapsed. Morphologically, two subgroups could be delineated. Six of the cases were characterized, besides by the classic RS cells, by a varying number of the cells with the distinctive walnutlike or cerebrumlike nuclei and cytologically with cytoplasmic processes. Their fine structural examination also revealed villous processes, but no desmosomes. The other three cases had multinucleated RS cells often with triangular nuclei, but not cytoplasmic processes. The percentage of CD21-positive tumor cells ranged from less than 10% to 60% among the H-RS cells. These RS cells were positive for CD30 (9 of 9), CD15 (7 of 9), CD68 (1 of 8), fascin (8 of 8), S-100 protein (1 of 7), and epithelial membrane antigen (2 of 8) on paraffin sections. Notably, of eight cases examined on frozen sections, two showed immunostaining for DRC1, CD35, R4/23, and Ki-M4p. Only CD35 was also detected in the other two cases. Genotypic investigation showed germline configuration of the T-cell receptor beta and gamma chain genes and the immunoglobulin heavy chain gene in all eight cases examined. In situ hybridization showed Epstein-Barr virus sequences in four cases, three of which were examined by the terminal region analysis and showed the Epstein-Barr virus to be monoclonal. We concluded that in a small proportion (9.6%) of HD, H-RS cells might be derived from FDCs and that they appear to represent a distinct pathologic variant based on morphologic and phenotypic traits within the framework of HD.

Molecular cytogenetic delineation of the breakpoint at 18q21.1 in low-grade B-cell lymphoma of mucosa-associated lymphoid tissue

Extranodal malignant non-Hodgkin lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma) represents a subtype of B-cell lymphoid malignancies with distinct clinicopathological features and is often associated with a favorable prognosis. Recent cytogenetic studies have revealed that t(11;18)(q21;q21) is a characteristic chromosomal aberration in low-grade B-cell MALT-type lymphoma. In the present study, we employed florescence in situ hybridization analysis using contiguous YAC clones mapped to the 18q21.1 region to identify a YAC clone, y789F3, encompassing the breakpoint of t(11;18)(q21;q21) in a MALT lymphoma. PI artificial chromosome (PAC) contigs constructed on this YAC clone were used to analyze the breakpoint region. PAC clone 264m4 was observed on normal chromosome 18 and on der(18), and PAC clone 879n 10 on normal chromosome 18 and on der(II), confirming that the breakpoint is located between these two PAC clones. We also found that a region of approximately 500 kb between the two PAC clones was deleted. These results indicate that the locus between PAC clones 264m4 and 879n 10 at 18q21.1 involved in t(11;18) translocation or associated deletion plays an important role in the development of MALT lymphoma.

Localization of mRNA for Dri 42, subtype 2b of phosphatidic acid phosphatase, in the rat brain during development

The expression of a gene termed Dri 42, a differentiation-related gene originally identified from intestine and a gene encoding phosphatidic acid phosphatase 2b isoform, was localized in developing and matured rat brains by in situ hybridization histochemical analysis. The gene expression was dominant in the ventricular germinal zone without significant expression in the intermediate, mantle and marginal zones throughout embryonic brain and spinal cord. The dominant expression in the ventricular germinal zone was maintained at P0 and P7, but it markedly decreased at later postnatal stages, while persistently high expression was detected in Bergmann glial cells of the cerebellar Purkinje cell layer throughout the postnatal development.

Prolongation of the effective duration of cytomedical therapy by re-injecting SK2 hybridoma cells microencapsulated within alginate-poly(L)lysine-alginate membranes into human interleukin-6 transgenic mice

We previously reported that SK2 hybridoma cells that secreted anti-human interleukin-6 (hIL-6) monoclonal antibodies (SK2 mAb) were microencapsulated within alginate-poly(L)lysine-alginate (APA) membranes (APA-SK2 cells) for immunoisolation, and a single intraperitoneal injection of these APA-SK2 cells remarkably improved IgG1 plasmacytosis in hIL-6 transgenic mice (hIL-6 Tgm). However, the duration of the effectiveness of APA-SK2 cells as a cytomedicine was unfortunately limited. In this study, we attempted to re-inject APA-SK2 cells into hIL-6 Tgm for the purpose of prolonging the cytomedical therapy. In hIL-6 Tgm re-injected with APA-SK2 cells, the plasma IgG1 level did not show any increase in 37 week old mice, and their survival time was at least three times longer than those of untreated hIL-6 Tgm. These results suggest that re-injected APA-SK2 cells survived and secreted SK2 mAb in the allogeneic mice. Thus, the limited duration of the cytomedical effects of APA-SK2 cells was probably caused by the disappearance of the inner space of microcapsules for cell proliferation, not by the rejection of the host's immune system. Therefore, if we can regulate the proliferation of the cells microencapsulated within a semipermeable membrane, we may be able to develop a cytomedicine which will continue its function longer after a single injection.

Polyclonal expansion of TCRBV2- and TCRBV6-bearing T cells in patients with Kawasaki disease

We examined T-cell receptor (TCR) usage, cytokine production and antibody responses to superantigens in patients with Kawasaki disease (KD) to facilitate a better understanding of the immunopathogenesis of KD. The mean percentage of VB2- or VB6. 5-bearing T cells in peripheral blood mononuclear cells (PBMC) of patients with acute-phase KD was significantly higher than that of patients in the convalescent phase of KD or in healthy donors. Expansion of VB2- or VB6.5-bearing T cells was polyclonal because DNA sequences in the complementarity determining region 3 of VB2- and VB6.5-positive cDNA clones were all different from each other. The plasma levels of interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL-10, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and granulocyte colony-stimulating factor (G-CSF) were elevated in the acute phase of KD. We previously reported that streptococcal pyrogenic exotoxin C (SPEC) was a potent stimulator of VB2- and VB6.5-positive T cells and, furthermore, serum levels of anti-SPEC antibodies were significantly higher in patients with acute and convalescent KD than in age-matched controls. The results of the present study, together with those of our previous report, suggest that SPEC induces activation and polyclonal expansion of VB2- and VB6.5-positive T cells, and that SPEC-induced activation of T cells may lead to the pathogenesis of KD.

The effectiveness of spinal and systemic morphine on rat dorsal horn neuronal responses in the spinal nerve ligation model of neuropathic pain

The treatment of pain arising from nerve injury can be difficult and the opioid sensitivity of neuropathic pain remains debatable. Clinical and animal studies report a wide range in the effectiveness of morphine, ranging from inadequate to potent analgesia. In this electrophysiological study we compare the effectiveness of spinal versus systemic administration of morphine on the natural and electrically evoked responses of spinal neurones of rats with a selective spinal nerve (L5/6) ligation. Recordings were made 1 week and/or 2 weeks after ligation. We have also compared the effects of morphine, by the two routes, on normal and sham operated animals. In spinal nerve ligated rats, morphine (0.1-5 microg) administered via the intrathecal route produced greater dose-dependent inhibitions of the neuronal responses compared with those produced by the systemic route (1-6 mg/kg). The dose response curves for intrathecal morphine on the C-fibre evoked and noxious natural stimuli evoked neuronal responses (mechanical and thermal) of spinal nerve ligated rats were to the left of those of sham operated and normal rats, suggesting an enhanced potency of intrathecal morphine after nerve injury. This was clearest for the lower doses of the opioid. The effects of spinal morphine on the responses to low intensity stimuli were similar in all groups of rats. In contrast to the spinal route, systemic morphine was less effective in inhibiting the evoked neuronal responses of spinal nerve ligated rats. This was especially clear for the C-fibre evoked and noxious natural stimuli evoked responses (mechanical and thermal) of spine nerve ligated rats. Our results suggest that the effectiveness of morphine may be partly related to the timing of the treatment relative to the duration of the neuropathy, the route of administration and also the neuropathic symptom. Spinal opioids may be a useful approach to pain control in neuropathic pain states where systemic routes produce inadequate analgesia.

Experimental metastasis is suppressed in MMP-9-deficient mice

Matrix metalloproteinases (MMPs) are thought to play a key role in tumor invasion and metastasis. The role of MMP-9 (gelatinase B) in tumor metastasis was examined in MMP-9-deficient mice produced by gene targeting using embryonic stem cells. MMP-9-deficient mice develop normally and are fertile. In these mice, the number of metastatic colonies of B16-BL6 melanoma cells or Lewis lung carcinoma cells that were implanted intravenously fell by 45% for B16-BL6 melanoma and 59% for Lewis lung carcinoma (p = 0.03 and p = 0.0043, respectively). Gelatin zymography showed that both tumor cell lines did not secrete MMP-9 by themselves but the host cells surrounding the tumor cells secrete MMP-9 in vivo. These results indicated that host-derived MMP-9 plays an important role in the process of tumor metastasis.

Specific interaction of fused H protein of bacteriophage phiX174 with receptor lipopolysaccharides

The DNA fragment encoding the spike H protein of bacteriophage phiX174 was amplified by polymerase chain reaction. The fragment was sub-cloned into pQE-30 to yield pQE-H. The histidine-tagged H protein (HisH) was obtained from the cell extract of Escherichia coli M15 (pREP4) harboring pQE-H and purified by nickel chelating and anion-exchange chromatographies. HisH was shown to bind dose-dependently to the lipopolysaccharides (LPSs) isolated from phiX174-sensitive strains, E. coli C or Salmonella typhimurium TV119 (Ra mutant). In sharp contrast, HisH did not bind to the LPSs from insensitive strains, E. coli F583 (Rd2 mutant) or E. coli O111:B4 (smooth strain). Since the same selectivity was observed in the plaque counting assay for in vitro inactivation of phiX174, the spike H protein was shown to recognize receptor LPS.

Graphic analysis of microscopic tumor cell infiltration, proliferative potential, and vascular endothelial growth factor expression in an autopsy brain with glioblastoma

BACKGROUND

Growth of brain tumors requires tumor-cell attachment to adjacent structures, degradation of surrounding matrixes, migration of tumor cells, proliferation of vasculature, and tumor cell proliferation. Comparison of the findings on neuroimaging, degrees and patterns of tumor invasion, regional tumor cell viability detected by Ki-67 immunohistochemistry, and regional vascular endothelial growth factor (VEGF) expression in whole-brain specimen of glioblastoma therefore is of great interest, and will facilitate study of the host reaction against the glioblastoma.

METHODS

We graphically analyzed microscopic tumor-cell infiltration, regional differences in Ki-67 labeling indices (LI), and immunohistochemical expression of VEGF in an autopsy brain with glioblastoma.

RESULTS

Glioblastoma cells infiltrated the brain far beyond the gross limits of the tumor and the areas with high signal intensity on T2-weighted magnetic resonance images. A wide range of histologic malignancy was apparent from hematoxylin-eosin staining and the Ki-67 labeling indices. VEGF was highly expressed in normal astrocytes located outside the tumor.

CONCLUSION

Graphic analysis of histologic and immunohistochemical patterns is a useful method of investigating the mechanisms of glioma growth, tumor cell infiltration in the brain, and the host reaction of the brain against neoplasms.

Establishment and characterization of nurse cell-like stromal cell lines from synovial tissues of patients with rheumatoid arthritis

OBJECTIVE

To investigate the features of synovial stromal cells established from patients with rheumatoid arthritis (RA), and to define these cells as nurse cells.

METHODS

Synovial nurse-like stromal cell lines (RA-SNCs) were established from patients with RA. These cell lines were examined for morphology, pseudoemperipolesis activity, cell surface markers, and cytokine production. The interaction between these RA-SNCs and a synovial tissue B cell clone was also examined.

RESULTS

RA-SNCs had nurse cell activity. They spontaneously produced interleukin-6 (IL-6), IL-8, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Furthermore, they produced IL-1beta and tumor necrosis factor alpha and expressed higher levels of the other cytokines after coculture with the B cell clone. Proliferation and Ig production by the B cell clone were dependent on direct contact with RA-SNCs.

CONCLUSION

These results indicate that the RA-SNCs were nurse cells. The findings suggest that RA-SNCs may play an important role in the pathogenesis of RA by producing large amounts of cytokines and maintaining infiltrating lymphocytes.

Blast crisis of chronic myelogenous leukemia exhibiting immunophenotypic features of a myeloid/natural killer cell precursor

We report a patient with Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) which transformed into blast crisis bearing the immunophenotypic features similar to those of the myeloid/natural killer (NK) cell precursor leukemia we proposed previously. Using a CD45 blast gating method, the myeloperoxidase-negative blasts were positive for CD7, CD13, CD33, CD34, CD56, and HLA-DR, but no other lymphoid antigens. Southern blot analysis showed germ line T cell receptor beta and delta genes and immunoglobulin heavy and light chain genes. Although NK cell blastic transformation with Ph1 positive CML has been reported in a single patient, this is, to our knowledge, the first report of CML blast crisis of myeloid/NK cell precursor origin.

Magnetic resonance imaging findings in cerebral fat embolism: correlation with clinical manifestations

OBJECTIVES

Cerebral fat embolism (CFE) is a serious complication after fracture of long bones. The mortality rate of CFE may be high. However, recent progress in treatment may decrease the mortality. We studied the validity of magnetic resonance imaging (MRI) to detect and grade severity of CFE in 11 patients with CFE.

METHODS

Glasgow Coma Scale score, PaO2, PaCO2 at the onset, and minimal hemoglobin and platelet levels were monitored, and phagocytes in bronchoalveolar lavage fluid were counted. Brain computed tomographic and MRI scans were performed serially. MRI findings were graded into four categories according to the severity of T2-weighted images.

RESULTS

High-intensity T2 signals were identified in the various brain regions as early as 4 hours after onset of CFE. The maximum MRI grade significantly correlated with Glasgow Coma Scale score at the onset of CFE (p < 0.01). High-intensity T2 signal lesions fused and enlarged with time. In most cases, they diminished within 2 weeks. Three patients had persistent morbidity.

CONCLUSION

MRI-T2-weighted imaging seems to be the most sensitive imaging technique for diagnosing CFE, and correlates well with the clinical severity of brain Injury. With the aid of proper treatment for pulmonary fat embolism, CFE is a potentially reversible disease that can have a good outcome.

Establishment of an inducible expression system of chimeric MLL-LTG9 protein and inhibition of Hox a7, Hox b7 and Hox c9 expression by MLL-LTG9 in 32Dcl3 cells

The MLL (HRX/ALL-1 gene is frequently disrupted in infantile leukemias and therapy-related leukemias and fused to various translocation partner genes. We previously showed that chimeric MLL proteins localize in the nuclei in a fashion similar to that of MLL protein even if the partner gene encodes a cytoplasmic protein and indicated the importance of the N-terminal portion of MLL common to various MLL translocations. This time we established an inducible expression system for chimeric MLL-LTG9 and truncated N-terminal MLL proteins (MLL-Zf(-)) in 32Dcl3 cells. By utilizing this system, we were able to show inhibition of Hox a7, Hox b7 and Hox c9 genes' expression by induced MLL-LTG9 and MLL-Zf(-). Up-regulation of Hox a7, Hox b7 and Hox c9 was observed when 32Dcl3 cells were cultured with granulocyte colony stimulating factor (G-CSF) in place of interleukin 3 and induction of MLL-LTG9 and MLL-Zf(-) was shown to suppress this upregulation. At the same time, expression of two mammalian Polycomb group genes, M33 and mel-18, which both reportedly affect Hox genes' expression, was not inhibited by MLL-LTG9 and MLL-Zf(-) induction. These results indicate that MLL has an important effect on the expression of at least some Hox genes in hematopoietic cells and suggest that inhibition of the proper expression of Hox genes by chimeric MLL proteins may dysregulate hematopoietic cell differentiation and proliferation, which then can lead to leukemogenesis.

[Erosive duodenitis after eradication therapy for Helicobacter pylori]

We studied the characteristics of erosive duodenitis after eradication therapy for Helicobacter pylori (Hp). Fifty-nine patients with Hp-positive peptic ulcer disease were treated with a combination of amoxicillin, clarithromycin, lansoprazol, and polaprezinc Subsequently, erosive duodenitis developed in 18 (43.2%) of 44 patients in whom Hp was eradicated successfully. There were no significant differences in demographic characteristics between the patients in whom duodenitis developed and those whom it did not, except that the incidence of duodenal ulcer before treatment was highte in the former group than in the latter. Erosions were located not only in the anterior wall of the first portion of the duodenum but also in the posterior wall or the second portion. Our results suggest that the development erosive duodenitis after Hp eradication therapy is a favorable, rather than an unfavorable, event, because erosive duodenitis appeared only in the patients with in whom Hp was successfully eradicated, moreover, the patients with duodenitis had no complaints and had a good prognosis without follow-up treatment.

[Isolation of Shiga toxin-producing Escherichia coli O157:H7 from processed salmon roe associated with the outbreaks in Japan, 1998, and a molecular typing of the isolates by pulsed-field gel electrophoresis]

Shiga toxin-producing Escherichia coil (STEC) O157 were isolated from processed salmon roe which had been a suspected food item in sporadic infections which occurred in Japan in 1998. A total of 45 samples of the processed salmon roe were pre-enriched in trypticase soy broth (TSB) at 36 degrees C for 6 h and novobiocin-supplemented modified EC broth (mEC-NB) at 42 degrees C for 18 h. After the pre-enrichments, the cultures were examined for possible occurrence of STEC O157, using an immunomagnetic separation (IMS) method. From the examination, a total of 84 strains of STEC O157:H7 that were positive for both stx 1 and stx 2 genes were isolated. By applying the most-probable-number technique, it was estimated that the number of STEC O157 was in the range of 0.73-1.5 per 10 g of the processed salmon roe. Subsequent analysis of the isolates by a pulsed-field gel electrophoresis (PFGE) revealed a pattern commonly seen in 82 isolates and another pattern in two isolates. Clinical isolates from 7 patients also showed an identical pattern to those of the 82 isolates and one isolate from a patient showed the other pattern identical to those of the two isolates. The isolates were found to belong to the phage type 14.