Dnmt2 is not required for de novo and maintenance methylation of viral DNA in embryonic stem cells

We have shown previously that de novo methylation activities persist in mouse embryonic stem (ES) cells homozygous for a null mutation of Dnmt1 that encodes the major DNA cytosine methyltransferase. In this study, we have cloned a putative mammalian DNA methyltransferase gene, termed Dnmt2 , that is homologous to pmt1 of fission yeast. Different from pmt1 in which the catalytic Pro-Pro-Cys (PPC) motif is 'mutated' to Pro-Ser-Cys, Dnmt2 contains all the conserved methyltransferase motifs, thus likely encoding a functional cytosine methyltransferase. However, baculovirus-expressed Dnmt2 protein failed to methylate DNA in vitro . To investigate whether Dnmt2 functions as a DNA methyltransferase in vivo , we inactivated the Dnmt2 gene by targeted deletion of the putative catalytic PPC motif in ES cells. We showed that endogenous virus was fully methylated in Dnmt2 -deficient mutant ES cells. Furthermore, newly integrated retrovirus DNA was methylated de novo in infected mutant ES cells as efficiently as in wild-type cells. These results indicate that Dnmt2 is not essential for global de novo or maintenance methylation of DNA in ES cells.

CD86 (B7-2) antigen on B cells from atopic patients shows selective, antigen-specific upregulation

To determine whether B7 signals are associated with atopic responses in man, we assayed CD80 and CD86 expression on B cells and monocytes from atopic patients and controls. Peripheral blood mononuclear cells from 10 patients with perennial allergic rhinitis and from 10 normal subjects were cultured in the presence or absence of house-dust-mite antigen, and B cells and monocytes were assayed for expression of CD80 and CD86 by flow cytometry. CD86 on B cells was significantly and selectively upregulated in all atopic subjects, but not in normal subjects, whereas CD80 expression was not altered in B cells from the atopic subjects or controls. In contrast, both CD80 and CD86 were upregulated in monocytes from the atopic subjects as well as the controls. However, CD86 upregulation was significantly higher in the atopic subjects than in controls. Our results seem to suggest that selective upregulation of CD86 on B cells by a challenging antigen may play a critical role in the development of Th2 cells in patients with atopic disease.

A 75-kD autoantigen recognized by sera from patients with X-linked autoimmune enteropathy associated with nephropathy

Autoimmune enteropathy (AIE) is a rare disorder characterized by intractable diarrhoea and antienterocyte autoantibody. In this study, we detected a 75-kD autoantigen which distributed through the whole intestine and the kidney, as assessed by Western blot analysis using sera from two unrelated cases of AIE associated with nephropathy. Our results suggest that the detection of the autoantibody against the 75-kD antigen has a diagnostic value in AIE and that the autoimmune reaction against the 75-kD antigen may be implicated in the development of intestinal and renal tissue damage in this rare disorder.

Correlation of expression levels of P-glycoprotein with resistance to adriamycin in a renal adenocarcinoma cell line

We have demonstrated that low-level expression of P-glycoprotein (PGP), detectable by reverse transcriptase polymerase chain reaction (RT-PCR) assay and flow cytometric assay, is an important factor in multidrug resistance (MDR) in ACHN cancer cells. In this study, we established a subline highly resistant to adriamycin (ACHN/ADM) from ACHN cells, and determined the correlation between PGP levels and MDR levels using ACHN/ADM cells and their parent ACHN cells. The ACHN/ADM cells showed overexpression of PGP, and sensitivity to antitumor agents was lower than that found in ACHN cells. Intracellular accumulation of ADM in ACHN/ADM cells was approximately half the amount of its accumulation in ACHN cells. Sensitivity to ADM in ACHN/ADM cells was enhanced by chemosensitizers with an increase in intracellular ADM accumulation. These results indicate that PGP levels correlate with MDR levels and suggest that chemotherapy using chemosensitizers might be effective in the treatment of renal cancers with overexpression of PGP.

Epstein-Barr virus infection and its role in the expanding spectrum of human diseases

Recent advances of the various laboratory tests to detect Epstein-Barr virus (EBV) infection have clarified the causative role for a spectrum of EBV-associated diseases. They include lymphoproliferative disorders (LPD), which occur in immunologically compromised individuals, Hodgkin's disease (HD), chronic active EBV infection (CAEBV), virus-associated hemophagocytic syndrome (VAHS), certain forms of T cell lymphoma, and some gastric carcinomas, in addition to the classical EBV-associated diseases such as EBV genome-positive Burkitt's lymphoma (BL), undifferentiated nasopharyngeal carcinoma (NPC) and infectious mononucleosis (IM). This review intends to introduce the recent progress of studies on EBV infection mainly from the clinical points of view.

Successful peripheral T-lymphocyte-directed gene transfer for a patient with severe combined immune deficiency caused by adenosine deaminase deficiency

Ten patients with adenosine deaminase deficiency (ADA-) have been enrolled in gene therapy clinical trials since the first patient was treated in September 1990. We describe a Japanese ADA- severe combined immune deficiency (SCID) patient who has received periodic infusions of genetically modified autologous T lymphocytes transduced with the human ADA cDNA containing retroviral vector LASN. The percentage of peripheral blood lymphocytes carrying the transduced ADA gene has remained stable at 10% to 20% during the 12 months since the fourth infusion. ADA enzyme activity in the patient's circulating T cells, which was only marginally detected before gene transfer, increased to levels comparable to those of a heterozygous carrier individual and was associated with increased T-lymphocyte counts and improvement of the patient's immune function. The results obtained in this trial are in agreement with previously published observations and support the usefulness of T lymphocyte-directed gene transfer in the treatment of ADA-SCID.

Gammadelta T cells are not essential for control of cutaneous Leishmania major infection in genetically resistant C57BL/6 mice

As gammadelta T cells are believed to be involved in host defense against Leishmania major, the role of gammadelta T cells in immunity against this parasite was investigated. The growth of L. major was measured in alphabeta (T cell receptor [TCR] alpha -/-) and gammadelta (TCR delta -/-) TCR-deficient C57BL/6 mice and compared with growth in control (C57BL/6) mice. While TCR alpha -/- mice developed nonhealing lesions containing large numbers of parasites following L. major infection, TCR delta -/- and C57BL/6 mice effectively controlled the infection. Following in vitro stimulation, lymph node cells from C57BL/6 mice produced significantly more interferon (IFN)-gamma than those from TCR delta -/- mice during early and late phases of infection; however, both produced similar levels of IFN-gamma at postinfection week 6. Culture supernatants from both TCR delta -/- and C57BL/6 mice contained interleukin-4, at postinfection week 2 only. These results indicate that gammadelta CD3 T cells are not essential for mediating protection against cutaneous L. major infection in C57BL/6 mice.

Painful small-fibre multifocal mononeuropathy and local myositis following influenza B infection

A 47-year-old man experienced multifocal mononeuropathy and putative ganglionopathy associated with influenza B infection, characterized by aching and dysesthesia in the right arm and left leg with normal deep sense. He displayed muscle atrophy in the affected limbs, which might have resulted from local myositis or a disorder similar to neuralgic amyotrophy. Sural nerve biopsy revealed a severe loss of unmyelinated and thinly myelinated fibres, consistent with a small fibre neuropathy, without evidence of angiopathy or inflammation. We could not detect any other cause of the neuropathy except influenza B. In this case, it may be inferred that small-diameter neurons in the dorsal root ganglia and thinly- or nonmyelinated fibres were selectively involved through a post-infectious immune process. To our knowledge, small fibre neuropathy following influenza B has never been reported.

Differentiation-dependent expression of laminin-8 (alpha 4 beta 1 gamma 1) mRNAs in mouse 3T3-L1 adipocytes

We report that laminin-8 (alpha 4 beta 1 gamma 1) is the specific isoform of laminin synthesized in adipocytes. Reverse transcription-polymerase chain reaction (RT-PCR) of mRNA from mouse 3T3-L1 cells with paired primers for alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, beta 1, beta 2, beta 3, gamma 1 and gamma 2 laminins yielded amplified fragments only for alpha 4, beta 1 and gamma 1. A polyclonal antibody against mouse laminin-1 (alpha 1 beta 1 gamma 1) precipitated alpha 4 in addition to beta 1 and gamma 1, while the antibody against a deduced peptide sequence of mouse alpha 4 in addition to beta 1 and gamma 1 in addition to alpha 4. Thus, laminin-8 (alpha 4 beta 1 gamma 1) is the only isoform expressed in 3T3-L1 cells. Northern blots showed that the levels of alpha 4, beta 1 and gamma 1 mRNAs increased 2.5-fold during adipose conversion of 3T3-L1 cells. A 1062 bp cDNA fragment cloned by RT-PCR demonstrated a polymorphism in the mouse alpha 4 gene which would lead to five amino acid changes in the domain G.

[A Japanese family with paroxysmal dystonic choreoathetosis]

We present the first report of Japanese family with paroxysmal dystonic choreoathetosis (PDC). At least seventeen individuals of this family in six generations were affected by PDC by autosomal dominant inheritance. The affected individuals had attacks of choreoathetosis/dystonia-like involuntary movements without loss of consciousness. These attacks were precipitated by stress, caffeine, menstruation or ovulation, but not by sudden voluntary movements, which are common precipitating factors in paroxysmal kinesigenic choreoathetosis (PKC). MRI studies of the brain revealed no abnormalities. Some of the family members received clonazepam, or garlic with significant therapeutic effects, while one female case improved after hysterectomy. The pathogenesis of PDC remains unknown, but it could be attributed to a form of channelopathy. Recently, two linkage studies were reported and the PDC locus was identified on chromosome 2q, which may lead to clarify the PDC gene. The family described here may be important for the future biochemical and genetic analyses. We also suspect that PDC may relate to endocrinological abnormalities besides channelopathy.

Comparison of surgical results of responders and non-responders to the prism adaptation test in intermittent exotropia

The data for 94 consecutive patients with intermittent exotropia of basic type, ranging from 20 to 40 prism diopters (delta), who preoperatively wore neutralizing prisms for 3 to 5 days, were studied retrospectively. The surgery in 43 patients in whom the amount of increase of angle was 4delta or less was based on the original angle (Group A), while that in 51 patients in whom the magnitude of increase was 5delta or more was based on the increased angle of deviation (Group B). Patients with initial deviation less than 30delta and patients younger than 7 years of age showed an increase of deviation with prism correction. There were no significant differences in surgical results between the two groups at 1 year, and at 3 years; although at 3 years satisfactory motor alignment and binocular function for single vision at distance was higher in Group B than that in Group A.

[Analysis of induction of MDR1 gene expression by anticancer chemotherapy in bladder cancer]

Using a reverse transcriptase-polymerase chain reaction (RT-PCR)-based quantitative analysis method, we investigated MDR1 mRNA expression levels in 58 bladder cancer specimens to determine whether MDR1 gene expression was induced or enhanced in bladder cancers during chemotherapy. In bladder cancer specimens which were obtained from patients treated with anticancer drugs, significantly higher expression levels of MDR1 mRNA were observed than in those from patients not treated with any anticancer drugs (p = 0.0134, Mann-Whitney U test). From 14 patients who had bladder cancer, clinical specimens were obtained before and after neoadjuvant intra-arterial chemotherapy. The expression levels of MDR1 mRNA were significantly higher in the post-treatment specimens than in the pre-treatment specimens (p = 0.0298, Wilcoxon signed-rank test). Of these 14 patients, 7 patients exhibited increased levels of MDR1 mRNA expression after chemotherapy. In 6 patients, there were no changes in the MDR1 mRNA expression levels before and after chemotherapy. Only one patient exhibited decreased levels of MDR1 mRNA expression after chemotherapy. No significant correlations were observed, between MDR1 mRNA expression levels and effect of the chemotherapy determined microscopically, dosage of anticancer drugs, or patient outcome. In conclusion, this study indicates that MDR1 gene expression in bladder cancers is induced and enhanced during chemotherapy. This overexpression of the MDR1 gene may contribute to resistance to anticancer drugs after repeated chemotherapy.

Anti-tuberculosis activity of quassinoids

In vitro evaluation of anti-tuberculosis activity was conducted for fifty-six quassinoids isolated in our laboratory from Simaroubaceous plants, Ailanthus altissima (= Aa, 10 compounds), Brucea antidysenterica (= Ba, 16 compounds), Picrasma ailanthoides (= Pa, 14 compounds), and Brucea javanica (= Bj, 16 compounds). Of the compounds tested, shinjulactone K (1), ailanthone (2), shinjudilactone (3), and dehydrobruceantin (4) were the most potent. Although the activities were very low (0-19%), the resulting data provided a picture of structure-activity relationships.

Synthesis of cytotoxic fluorinated quassinoids

The C-15 senecioyl side chain of brusatol was interchanged with fluorinated acyl groups, and the C-3 hydroxy group of bruceolide was esterified with fluorinated acyl chlorides. These fluorinated quassinoids 11, 12, 13, and 17 showed significant cytotoxic activity against eight human cancer cell lines including small and non-small cell lung, colon, CNS, ovarian and renal cancers, leukemia, and melanoma with 17 being about 100 times more potent than 11, 12, and 13. The activity of 17 was similar to that of bruceantin (1) in this in vitro cell line panel.

An exaggerated manifestation of penile cancer: a report from Japan

This report describes a Japanese case of penile carcinoma characterized by an extravagantly harsh clinical presentation. Report of penile cancer from Japan is extremely rare.

High susceptibility of an Epstein-Barr virus-converted Burkitt's lymphoma cell line to cytotoxic drugs

Susceptibility to cytotoxic drugs was studied using an Epstein-Barr virus (EBV) genome-negative Burkitt's lymphoma (BL) cell line (Ramos) originating from the tumor cells and an in vitro EBV-converted Ramos cell line (B7). Decreased doubling time (DT) with increased saturation density (SD) and elevated [3H]thymidine incorporation were shown in B7, indicating more rapid cell proliferation and growth. However, B7 was highly susceptible to cytotoxic drugs when compared to Ramos. These results indicated whether the presence or absence of EBV genome in tumor cells may be beneficial for evaluation of susceptibility to cytotoxic chemotherapy in patients with BL.

Extremely high serum level of IgE during immunosuppressive therapy: paradoxical effect of cyclosporine A and tacrolimus

A case of X-linked autoimmune enteropathy was successfully treated with cyclosporine A (CsA) or tacrolimus (FK506) and developed extremely high serum levels of IgE during the immunosuppressive therapy. Serum IgE levels increased from 190 to 1,000-2,500 IU/ml with CsA therapy and as high as 80,000 IU/ml with subsequent FK506 therapy. Serum IgG2 and IgG4 levels were slightly elevated compared to serum IgE levels. Thereafter, serum IgE levels progressively decreased in parallel with a reduced dosage of FK506. Total serum IgG levels and peripheral eosinophil counts, however, showed no significant changes during the course. These observations suggest that both CsA and FK506, potent immunosuppressants, could paradoxically enhance some immune responses, possibly through the action of CsA-/FK506-resistant immune systems.

Inhibitory effects of quassinoid derivatives on Epstein-Barr virus early antigen activation

Short-term in vitro assays for tumor promoters and antitumor promoters (Epstein-Barr virus activation test) were carried out for semisynthetic quassinoids (3-7), which were obtained by esterification of the C-15 OH group of deacetylated isobrucein-B (2). All the ester derivatives showed higher antitumor promoting activity than that of the potent compound 2. A compound containing a fluorinated aliphatic ester showed the highest potency.

Atypical MRI features of Wilson's disease: high signal in globus pallidus on T1-weighted images

Most reports of MRI in Wilson's disease have been of abnormal low-signal lesions on T1-weighted images and high signal intensity on T2-weighted images. In contrast, we report three patients who had high-signal lesions in the globus pallidus on T1-weighted images, a finding seen in patients with portal-systemic encephalopathy. The possible causes include the paramagnetic effect of copper or iron and accumulation of Alzheimer type II glial cells.

Therapeutic approaches for severe Epstein-Barr virus infection

Epstein-Barr virus, (EBV) is one of the eight known human herpesviruses and is associated with diseases in a spectrum from benign to lethal. Until recently, there has been no definite treatment for severe EBV infection. However, many therapeutic approaches have been attempted, and some of them seem to be beneficial for a certain EBV-associated disease. This review introduces them and provides a more rational basis for the treatment of severe EBV infection.

Quassinoids as inhibitors of Epstein-Barr virus early antigen activation

Short-term in vitro assays for tumor promoters and antitumor promoters (Epstein-Barr virus activation test) were carried out for 14 quassinoids isolated from Ailanthus altissima. Some quassinoids, including ailantinol B, ailantinol C, ailanthone, and shinjulactone A, showed moderate activity at a molar ratio of 1:100 (TPA/quassinoids), and the results led to the elucidation of structure-activity relationships.