Hereditary fructose intolerance presenting as Reye's-like syndrome: report of one case

Hereditary fructose intolerance (HFI) is an autosomal recessive disease caused by catalytic deficiency of aldolase B (fructose-1, 6-bisphosphate aldolase). Herein we report on a case of hereditary fructose intolerance with initial presentation of episodic unconsciousness, seizure, hypoglycemia, hepatomegaly, and abnormal liver function since the patient was 11 months old. She was diagnosed as Reye's-like syndrome according to a liver biopsy done at 20 months of age. As she grew up, cold sweating, abdominal pain or gastrointestinal discomfort shortly after the intake of fruits was noted and she developed an aversion to fruits, vegetables and sweet-tasting foods. At 9 years of age, a fructose tolerance test signified a positive result that induced hypoglycemia, transient hypophosphatemia, hyperuricaemia, elevation of serum magnesium, and accumulation of lactic acid. Appropriate dietary management and precautions were recommended. The patient has been symptom-free and exhibited normal growth and development when followed up to 12 years of age.

Long-term follow-up study of core gene deletion mutants in children with chronic hepatitis B virus infection

Core gene deletion mutants of hepatitis B virus (HBV) have been identified in adults. Because the acquisition of HBV occurs mainly in infancy and childhood in hyperendemic areas, this study aimed to learn the temporal profile of such mutants in children with chronic HBV infection. We have followed up 365 HBV-infected children for more than 10 years and screened out HBV core gene deletion from their sera. Serial serum samples of positive cases were subjected to HBV-DNA nucleotide sequence analyses and quantification. Deletion mutants were found in 18 of the 365 patients (4.9%). Most cases (15 of 18) with deletion mutants heralded hepatitis B e antigen (HBeAg) seroconversion phase, while the other cases (3 of 18) remained in HBeAg-seropositive phase. Deletion mutants disappeared after HBeAg seroconversion except in 1 child. Decreased HBV-DNA levels accompanied deletion mutants for those who finally underwent HBeAg seroconversion, but the HBV-DNA level did not decline if there was no seroconversion. Deletion mutants were not associated with a particularly high peak liver enzyme. Core gene deletion mutants could appear as early as the age of 5. The duration of their appearance was 0.5 to 5 years. Horizontal rather than perinatal transmission of HBV was a favorable factor for these mutants to develop. Deletion fragments were located in the middle part of core gene. The emergence of the mutants was likely the result of host-viral interaction and mostly signified HBeAg seroconversion within 1 year. Core gene deletion mutants appeared preferably in children acquiring HBV by horizontal transmission.

Modulation of the basal activity of phosphatidylinositol-3-kinase/protein kinase B signaling pathway in human hepatocarcinoma cells

The modulation of GnT-V activity by signaling molecules in PI-3-K/PKB pathway in human hepatocarcinoma cell line 7721 was studied. GnT-V activity was determined after the transfection of sense or antisense cDNA of PKB into the cells, as well as the addition of activators, specific inhibitors, and the antibodies to the enzyme assay system or culture medium. It was found that the basal activity of GnT-V was up regulated by the sense and down regulated by the antisense cDNA of PKB transfected into 7721 cells. GnT-V was activated by PIP2, PIP3 or GTPgamma[S] added to the assay system, and the activation of PIP2 or GTPgamma[S] was abolished by LY2940002, a specific inhibitor of PI-3-K, but the activation of PIP3 was not attenuated by LY2940002. In addition, GnT-V activity in cultured parental or H-ras transfected cells was inhibited by the antibody against PKB or PI-3-K. These findings demonstrated the involvement of PI-3-K/PKB signaling pathway in the regulation of GnT-V. Moreover, ET18-OCH3, an inhibitor of Raf translocation and PI-PLC enzyme, which produces the activator of PKC, as well as the antibodies against Raf-1 or MEK also inhibited GnT-V activity in the parental and H-ras transfected cells. The inhibitory rates, however, were less in the transfected cells than those in the parental cells. These results reveal that in parental and H-ras transfected 7721 cells, the basal activity of GnT-V is also regulated by the Ras/Raf-1/MEK/MAPK cascade in addition to PI-3-K/PKB signaling pathway. The significance of these two pathways in the regulation of GnT-V and their relations to the activation of PKC previously reported by our laboratory (Ju TZ et al., 1995 Glyconjugate J 12, 767-772) was discussed.

Effects of H-ras and v-sis overexpression on N-acetylglucosaminyltransferase V and metastasis-related phenotypes in human hepatocarcinoma cells

Oncogenes and N-acetylglucosaminyltransferase (GnT-V) are both commonly associated with carcinogenesis and metastasis. In order to elucidate the relationship between oncogenes and GnT-V, two oncogenes, H-ras and v-sis/PDGF (platelet-derived growth factor), were selected, and the effects of their overexpression on GnT-V in 7721 human hepatocarcinoma cells were investigated. The results showed that the over expression of H-ras or v-sis/PDGF-B up-regulated the activities of GnT-V to various degrees in the transfected cells. In H-ras- and PDGF-B-overexpressing cells, the activity of GnT-V was up-regulated to double the normal value. The transient expression of v-sis, which produces a protein almost identical to PDGF-B, stimulated the GnT-V activity by 80.3%, and the effect was more pronounced (increased by 182.5%) in 7721 cells with stable expression of v-sis. The stimulating effect was entirely abolished by treatment with PDGF-B antibody. The staining of asparagine-linked glycans (N-glycans) in the H-ras- and v-sis-overexpressing 7721 cells was intensified when horseradish peroxidase-labeled leucoagglutinating phytohemogglutinin was used as a probe, indicating the increased content of beta1,6GlcNAc branching on the N-glycans. The enhancement of GnT-V mRNA expression was also observed in H-ras- and v-sis- overexpressing cells, indicating that H-ras and v-sis regulated GnT-V via the transcription of GnT-V mRNA and the synthesis of GnT-V protein. The cells overexpressing H-ras and v-sis displayed some changes in metastasis-related phenotypes, including acceleration of cell growth, decline of cell adhesion to fibronectin, and an increase of cell adhesion to laminin, as well as increased invasiveness through Matrigel. These results indicated that the alteration of cell adhesion and invasion induced by oncogenes is closely related to the up-regulation of GnT-V activity and its product, beta1,6GlcNAc branching in N-glycans on the cell surface.

Transcriptional repression of p21((Waf1/Cip1/Sdi1)) gene by c-jun through Sp1 site

Previously, we found that c-jun represses the tumor suppressor p21((Waf1/Cip1/Sdi1)) (p21) gene expression. In this study, we further investigated the mechanism of the inhibitory effect of c-jun on p21. After analysis of a series of deletion and point mutants of p21 promoter, we found that Sp1-3 site (-77 and -83) relative to the transcription start site played an important role for c-jun-repressing-responsive element in the p21 promoter. Both Sp1 and Sp3 transcription factors were the key factors for this event. However, the data from electrophoretic mobility shift assay indicated that c-jun did not change the Sp1 DNA-binding affinity, suggesting that additional factors may be involved in the repression of p21 by c-jun. Furthermore, c-jun could inhibit butyrate-inducing p21 gene expression through Sp1, indicating at least one common pathway whereby p21 expression is affected by c-jun and butyrate in opposing actions. Moreover, the hyperphosphorylated retinoblastoma protein (Rb) increased in c-jun expressing cells, indicating that phosphorylated Rb may play a role in regulating Sp1 to repress p21 expression. This is the first demonstration of how housekeeping factors and oncogene product counteract the function of tumor suppressor genes to control cell cycle progression.

[Contents of general flavonoides in Epimedium acuminatum Franch. and its differently-processed products]

OBJECTIVE

Determining and comparing the contents of general flavonoides in four kinds of differently-processed products of Epimedium acuminatum.

METHOD

Determining the contents by ultraviolet spectrophotometry.

RESULT

The contents were found in the following seguence: unprocessed product, clearly-fried product, alcohol-broiled product, salt-broiled product, sheep-fat-broiled product. The average recovery rate was 96.01%, with a 0.74% RSD(n = 5).

CONCLUSION

Heating causes the contents of general flavonoides in the processed products to decrease. These processed products are still often used in clinical treatment, for the reason that the adjuvant features certain coordinating and promoting functions. The study is to be pursued further.

Regulation of phospholipase D from human hepatocarcinoma cell line by purine nucleotides and protein kinase A

The regulation of phosphatidylcholine-specific phospholipase D by purine nucleotides and protein kinase A were studied in vitro using an enzyme preparation partially purified from the membranous fraction of 7721 hepatocarcinoma cells. It was found that the enzyme activity was elevated by low concentrations of some purine nucleotides, but the activating effects were decreased when the concentrations of the nucleotides were higher. The optimal concentrations of GTP, GTPgamma[S], GDP and ATP for maximal activation were 0.1 mM, 5 microM, 1 mM and 1 mM respectively. The activation caused by 1 mM ADP was lower. The enzyme was not activated by 1 mM AMP, but significant activation was observed by the addition of 1 mM cAMP. The latter was mediated by protein kinase A, as a specific inhibitor of protein kinase A abolished the activation. There were synergic effects between ATP and GTP, ATP and PIP2, but not between ATP and GTPgamma[S], or PIP2 and GTPgamma[S]. The activating effects of GTP and ATP were abolished by neomycin, a PIP2 scavenger. These results suggest that phospholipase D is regulated by GTP-binding protein and the presence of PIP2 is required for the activation induced by GTP. Protein kinase A may be another protein kinase in addition to protein kinase C and protein tyrosine kinase which regulate the activity of phospholipase D, when the intracellular concentration of cAMP is increased.

Opposing changes in N-acetylglucosaminyltransferase-V and -III during the cell cycle and all-trans retinoic acid treatment of hepatocarcinoma cell line

The changes in N-acetylglucosaminyltransferase-V and -III (GnT-V, GnT-III) during the cell-cycle of synchronized 7721 human hepatocarcinoma cell line were investigated. Using an HPLC method to assay GnT and flow cytometry (FCM) for cell cycle analysis, it was found that GnT-V showed the highest activity, but GnT-III reached the lowest activity when G(2)/M cells were most abundant. In contrast, GnT-V declined to the minimum while GnT-III elevated to maximum when G(0)/G(1) cells were most predominant. The opposing changes were more obvious when the activities of GnT-V and GnT-III were expressed as relative activities (activity of GnT-V or GnT-III/the sum of activities of GnT-V plus GnT-IV plus GnT-III). These opposing changes of GnT-V and GnT-III during the cell cycle might result from the different regulatory mechanisms of GnT-V and GnT-III expression in the cell cycle. The alterations in the structures of cell surface N-glycans were compatible with the changes of the activities of GnTs. The results from immunocytochemistry and Northern blot showed that the protein and mRNA contents of GnT-V were not significantly changed during the cell cycle. The activity of a cell cycle regulating protein kinase, p34(cdc2) kinase, correlated to the activity of GnT-V. These findings suggested that the change of GnT-V activity in cell cycle was not the consequence of the alteration of gene transcription or enzyme protein synthesis, but might be caused by the post-translational regulation. The decrease in GnT-V and the corresponding increase in GnT-III activities were also found after the cells were treated with all-trans retinoic acid (ATRA), and the mechanism of this might be different from that in the cell cycle.

Effects of all-trans retinoic acid and epidermal growth factor on the expression of nm23-H1 in human hepatocarcinoma cells

The effects of all-trans retinoic acid (ATRA) and epidermal growth factor (EGF) on the expression of nm23-H1, a metastasis suppressor gene, were studied in a human 7721 hepatocarcinoma cell line. It was discovered that the expression of nm23-H1 mRNA was up-regulated by ATRA. This was compatible with the observation that the metastasis-associated phenotypes, such as chemotaxic cell migration and invasion, were both reduced in the ATRA-treated and nm23-H1-cDNA-transferred 7721 cells. However, ability of cells to adhere to fibronectin and laminin was not altered identically in the ATRA-treated and nm23-H1-cDNA-transfected 7721 cells. In contrast, the expression of nm23-H1 mRNA in 7721 cells was down-regulated both by the treatment with EGF and by the transfection of c-erbB-2/neu cDNA, which codes a protein homologous to the EGF receptor. EGF is a compound with biological effects opposite to those of ATRA, and c-erbB-2/neu is known to be a metastasis-promoting gene. These results reveal that the metastasis-preventing effect of ATRA may partly result from the up-regulation of nm23-H1, and the metastasis-promoting effects of EGF and c-erbB-2/neu were probably mediated in part by the down-regulation of nm23-H1.

Differential regulation of FGF-1 and -2 mitogenic activity is related to their kinetics of binding to heparan sulfate in MDA-MB-231 human breast cancer cells

The growth of the malignant human mammary MDA-MB-231 cells is stimulated by fibroblast growth factor-1 (FGF-1) but not by FGF-2. When these cells are cultured in the presence of chlorate, an inhibitor of heparan sulfate (HS) sulfation, their proliferation is stimulated by both FGF-1 and FGF-2. We analyzed the interactions of FGF-1 and FGF-2 with HS purified from the cell layer and the culture medium of control and chlorate-treated MDA-MB-231 cells. The HS from the cell layer bound FGF-1 with faster association kinetics than the HS from the culture medium, and so had a higher affinity for FGF-1. Chlorate treatment had no significant effect on the FGF-1 binding kinetics of the HS. In contrast to FGF-1, chlorate treatment of the cells significantly altered the FGF-2 binding kinetics. The HS from untreated cells possessed two binding sites for FGF-2, one with fast association kinetics (k(ass) 470,000 to 610,000 M(-1) s(-1)) and a high affinity (K(d) 46 to 70 nM) and one with slower association kinetics (k(ass) 74,000 to 100,000 M(-1) s(-1)) and a lower affinity (K(d) 290 to 400 nM). HS from chlorate-treated cells possessed just a single binding site for FGF-2 with fast association kinetics (k(ass) 270,000 to 290,000 M(-1) s(-1)) and a high affinity (K(d) 41 to 57 nM). These results show that there is a relationship between the binding kinetics of FGFs and their ability to stimulate cell growth.

Muscarinic regulation of basal versus thyrotropin-releasing hormone-induced prolactin secretion in rat anterior pituitary cells. differential roles of nitric oxide and intracellular calcium mobilization

Acetylcholine (ACh), synthesized in the pituitary, can act locally to modulate pituitary function. We used rat primary anterior pituitary (AP) cells to investigate how ACh affects pituitary prolactin (PRL) secretion in the presence or absence of known PRL regulators: thyrotropin-releasing hormone (TRH), 17beta-estradiol (E(2)) and triiodothyronine (T(3)). Cultured AP cells were prepared from ovariectomized rats and pretreated with diluent, 0.6 nM E(2), 10 nM T(3), or E(2) plus T(3) for 5 days, then challenged with various doses of ACh or muscarinic receptor agonists (oxotremorine or carbachol) and TRH (100 nM) for 20 min. Significant ACh (10(-5) M) suppression of both basal and TRH-induced PRL secretion was not evident in diluent-, E(2)- or T(3)-pretreated cells, but observed only in cells pretreated with both E(2) and T(3). Moreover, in E(2) plus T(3)-pretreated cells, oxotremorine and carbachol, like ACh (10(-7)-10(-5) M), suppressed both responses in a dose- related manner. Pertussis toxin (PTX; 100 ng/ml) as well as atropine (a muscarinic receptor antagonist; 1 mM) blocked these effects of cholinomimetics. ACh also inhibited both PRL responses elicited by drugs elevating intracellular cAMP (10 microM forskolin) or Ca(2+) (1 microM Bay K-8644) in a PTX-sensitive manner. ACh inhibition of basal PRL secretion was unaltered by intracellular Ca(2+) mobilization blockers, TMB-8 (100 microM) and thapsigargin (1 microM), but abrogated by the nitric oxide synthase inhibitor (300 microM L-NAME). ACh inhibition of TRH-induced PRL secretion was accentuated by TMB-8 and alleviated by thapsigargin or L-NAME. In summary, muscarinic inhibition of either basal or TRH-induced PRL secretion was augmented by E(2) and T(3), and involved the PTX-sensitive cAMP/Ca(2+) pathways. Furthermore, nitric oxide mediated the basal rather than TRH-induced PRL response to ACh, whereas the intracellular Ca(2+) mobilization concerned the TRH-induced rather than the basal PRL response to ACh. Thus, ACh synthesized in the AP appears to inhibit basal vs. TRH-induced PRL secretion via different mechanisms.

Changes of hepatitis B surface antigen variants in carrier children before and after universal vaccination in Taiwan

Mutants of a determinant of hepatitis B surface antigen (HBsAg) identified in vaccinated children pose a potential threat to long-term success of vaccination programs. We examined the mutants of a determinant (residues 110-160) of HBsAg in hepatitis B virus (HBV) DNA-positive children identified during previous serosurveys in Taipei undertaken just before (1984), 5 years after (1989), and 10 years after (1994) universal vaccination began. In HBV DNA-positive children from 3 surveys, the prevalence of a determinant mutants increased from 8 of 103 (7.8%) in 1984 to 10 of 51(19.6%) in 1989 and 9 of 32 (28.1%) in 1994 and was higher in those fully-vaccinated than unvaccinated (12/33 vs. 15/153, P =. 0003). Most amino acid changes of the variants clustered in residues 125-129 and 140-149. In all 27 children with detectable mutants, the mean age of those vaccinated was younger than those unvaccinated (4. 8 +/- 3.8 vs. 7.9 +/- 2.3 yrs, P <.05); and mutations occurred in a region with greatest local hydrophilicity (residues 140-149) more frequently in those vaccinated than in those unvaccinated (10/12 vs. 6/15, P =.0253). More mutated residues and more mutations at neutralizing epitopes, such as N146, C147, T148, and C149, were found in the 1994 survey. Vaccinated children may contract variant infections through vertical or horizontal transmission. Universal vaccination has accelerated an accumulation of HBsAg a determinant mutants with amino acid changes critical for immune escape in vaccinated children who became carriers, suggesting that new vaccination strategies should be considered.

Increased susceptibility to apoptosis of human hepatocarcinoma cells transfected with antisense N-acetylglucosaminyltransferase V cDNA

The antisense cDNA of N-acetylglucosaminyltransferase V (GnT-V, EC 2. 4.1.155) was constructed as pcDNA3/GnT-V-AS plasmid and transfected into 7721 cells, a human hepatocarcinoma cell line. The transfection was confirmed with Northern blot. By using HPLC and HRP-lectin staining, it was found that the cells transfected with pcDNA3/GnT-V-AS (GnT-V-AS/7721) expressed less GnT-V activity and beta-1,6-GlcNAc branching in the cell glycoproteins compared with the cells mock-transfected with the vector pcDNA3 (pcDNA3/7721). The growth rate of GnT-V-AS/7721 was decreased in serum-containing medium, while the cell death was accelerated in serum-free medium. The GnT-V-AS/7721 cells were more susceptible to the apoptosis induced by ATRA than the mock-transfected cells. This was evidenced by the obvious appearance of a hypoploid sub-G(1) fraction in the DNA histogram using FCM analysis, the more condensed new moon-type nuclei under morphological observation, and the more intensive TUNEL reaction for assaying the fragmented DNA. At the same time as GnT-V down-regulation by GnT-V-AS, an increase of another N-aceylglusaminyltransferase, GnT-III (EC 2.4.1.144), was observed, and the biological significance of this finding was discussed.

Cutaneous lymphocyte antigen is expressed on memory/effector B cells in the peripheral blood and monocytoid B cells in the lymphoid tissues

Cutaneous lymphocyte antigen (CLA) is expressed on a subpopulation of human memory T cells and is involved in the primary step of their skin homing. T cells and some B cells in the peripheral blood express CLA, but the pathophysiologic roles of CLA(+) B cells have not yet been clarified. We examined the relationships among CLA expression in B cells and immunoglobulin heavy chain subtype, the localization of CLA(+) B cells in the peripheral lymphoid tissues, and their functional binding to E-selectin. CLA was expressed on class-switched, memory B cells in the peripheral blood and tonsils as revealed by flow cytometry. Immunohistochemical staining of the lymph nodes with various types of inflammation or reactive hyperplasia showed CLA on the monocytoid B cells, which correspond to memory cells. The functional study revealed that CLA on B cells bound to E-selectin transfectants. E-selectin was detected on some of the high endothelial venules in the monocytoid B-cell-rich lymph nodes. These findings suggest that CLA is also expressed on a subset of memory/effector B cells, in addition to a subset of memory T cells. Such B cells were located in the lymph nodes or tonsils and rarely in chronic dermatitis. Therefore, CLA seems to be related to memory/effector B-cell trafficking to the lymph nodes or tonsils. According to the multistep theory, mechanisms involved in the second or third step might be different between CLA(+) B and T cells.

Thrombocytosis in children at one medical center of southern Taiwan

Thrombocytosis in children is common, but usually without symptoms. The causes of thrombocytosis in children are considered to be mostly due to infection, trauma, surgery, blood disease, prematurity, renal disease and chronic inflammation. To evaluate the incidence and etiology of thrombocytosis of the hospitalized patients, patients who were admitted to the Pediatric Department of Kaohsiung Medical College Hospital (KMCH) from October 1996 to November 1997 were studied. There were 2910 cases studied and 220 cases (127 male and 93 female) had thrombocytosis (> or = 500 x 10(9)/L) with a rate of 7.6%. The causes of thrombocytosis are infections (49.5%), Kawasaki disease (6.4%), postsplenectomy (7.8%), blood diseases (3.7%), malignancies (3.2%), renal disorders (3.2%), prematurity (3.2%), tissue damage (4.5%), chronic inflammation (1.8%), recovery from marrow suppression (1.3%), immunologic disturbances (2.2%), essential thrombocythemia (0.5%), and miscellaneous factors (3.7%). Thrombocytosis associated with multiple, simultaneous causative factors was found in 9.0% of these cases. Thrombocytosis secondary to infectious diseases or Kawasaki disease was significantly more common in children under 2 years old. The most commonly associated infectious disease was respiratory tract infection (61.1%). There were 29 children (13.2%) presenting a platelet count of more than 800,000/mm3. However, no thrombotic complications were seen in any of the children. By far, the major cause of thrombocytosis in our cases was reactive in character. Most of the thrombocytosis cases were due to infections, inflammatory diseases, or Kawasaki disease.

Alterations in glycosyltransferases during myeloid and monocytoid differentiation of HL-60 cells

HL-60, a human promyelocytic leukemia cell line, can be differentiated to myeloid lineage by all- trans retinoic acid (ATRA), dimethylsulfoxide (DMSO) and n -butyric acid (n -BA), or to monocytoid(monocytic/macrophagic) lineage by phorbol-12-myristate-13-acetate (PMA) and ganglioside GM(3). The activity alterations of N -acetylglucosaminyltransferase III and V (GnT-III, GnT-V) as well as alpha-1,6-fucosyl-tranferase (alpha1,6 Fuc T) were studied during the differentiation of HL-60 cells by the above-mentioned five inducers using the fluorescence (PA)-labeled glycan-HPLC method for GnT assays and biotin-labeled glycan-LCA affinity chromatography combined with the HRP-avidin colorimetric method for alpha1,6 Fuc T assay. It was observed that after 3 days, all three enzymes decreased in HL-60 cells induced by 1 micromol/l ATRA and 0.6 mmol/l n-BA, while GnT-III and alpha1,6 Fuc T increased, but GnT-V still decreased after induction by 1% DMSO. GnT-V and alpha1,6 Fuc T declined, while GnT-III was elevated after induction by 0.1 micromol/l PMA for 3 days. In contrast, GnT-III increased after the treatment with 50 micromol/l GM(3)for 3 or 6 days, but GnT-V was not appreciably changed and alpha1,6 FucT was elevated after 6 days of GM(3)treatment. It may be concluded that the decrease of GnT-V is the common change in myeloid differentiation and the increase of GnT-III is the general alteration in monocytoid differentiation. The changes in the activities of glycosyltransferases were consistent with the structural changes in surface N -glycans previously found in our laboratory, i.e. that the antennary number of N -glycans decreased during myeloid differentiation by ATRA, and the amount of bisecting GlcNAc in N -glycans increased during monocytoid differentiation by PMA.

Hexamethyldisiloxane film as the bottom antireflective coating layer for ArF excimer laser lithography

We demonstrate a new bottom antireflective coating (BARC) layer for ArF excimer laser lithography. The antireflective layer is composed of hexamethyldisiloxane (HMDSO) film, which is deposited by the conventional electron cyclotron resonance-plasma-enhanced chemical-vapor deposition process. We obtain the appropriate HMDSO films for BARC layers by varying the gas-flow rate ratio of oxygen to HMDSO. Such a process has several advantages: high deposition rate, low process temperature, easy film removal, and reduced cost. Measured reflectances of less than 0.5% on both Al-Si and silicon crystal substrates have been achieved and agree well with the simulated reflectances. The swing effect is shown to be significantly reduced by addition of the HMDSO-based BARC layer.

Cyno-EBV (EBV-related herpesvirus from cynomolgus macaques) induces rabbit malignant lymphomas and their tumor cell lines frequently show specific chromosomal abnormalities

Malignant lymphoma (ML) induction in rabbits by Epstein-Barr virus (EBV)-related herpesvirus of cynomolgus (Cyno-EBV) is reported. Twenty-seven of 30 (90%) rabbits inoculated intravenously with Cyno-EBV-producing simian (cynomolgus) lymphocyte cell line (Ts-B6) cells developed ML between 45 and 115 days after inoculation. The peroral inoculation of Ts-B6 cells induced ML in only 2 of 10 (20%) rabbits (75 to 85 days). Five of 6 (83%) rabbits injected with cell-free pellets from Ts-B6 cultures also developed ML (27 to 122 days). Antibody response to the viral capsid antigen of EBV was also detected in sera from rabbits inoculated with Ts-B6. ML of the large cell or mixed type infiltrated diffusely in many organs, frequently involving the spleen, liver, kidneys, heart, and less frequently the lungs, lymph nodes, brain, eyes, gastrointestinal tract, thymus, and bone marrow. A chromosomal analysis of five lymphoma cell lines established from tumor-bearing rabbits revealed the rabbit karyotype. Three of these cell lines showed the chromosomal abnormalities with 12q- or t (7p+:12q-). EBV-encoded small RNA-1 and EBV-associated nuclear antigen 1 were expressed in Ts-B6 cells, the tumor tissues, and all rabbit cell lines by in situ hybridization and by immunofluorescence tests, respectively. EBV DNA was also detected in Ts-B6 cells and rabbit lymphoma cell lines by polymerase chain reaction and Southern blot analysis. The Southern blots of EBV termini revealed oligoclonal bands in the Cyno-EBV-induced rabbit lymphomas. No lymphoma was induced by the inoculation of B95-8 (EBV-producing cells) or peripheral leukocytes from normal cynomolgus (controls). These data suggest that the high rate of lymphoma induction in rabbits may be caused not by human EBV (B95-8) but by Cyno-EBV from Ts-B6 cells. A sequence analysis of the IR1 (BamHIW) region of Cyno-EBV revealed that this region is quite similar to that of herpesvirus Macaca fascicularis 1, which is a causative agent for a monkey model of AIDS-related lymphomas. The present rabbit model of lymphoma with specific chromosomal abnormalities is very useful to clarify the role of EBV in human EBV-associated lymphoma and provides a means for studying prophylactic and therapeutic regimens.

Interference coatings based on synthesized silicon nitride

Silicon nitrides are synthesized by ion-assisted deposition with only one coating material and a nitrogen-ion-beam source. All the SiN(x) films are amorphous and mechanically strong. A wide range of refractive indices from 3.43 to 1.72 at a wavelength of 1550 nm is obtained. Near-IR antireflection coating and a bandpass filter based on the multilayers of SiN(x) and Si are demonstrated.

Primary sclerosing cholangitis in a child

Primary sclerosing cholangitis (PSC) is a rare disease in Taiwan and has not been described in Taiwanese children previously. We report a 4-year-old girl who presented with prolonged fever, eosinophilia (11%), hepatomegaly, and markedly elevated serum levels of alkaline phosphatase (3,318 IU/L) and gamma-glutamyl transpeptidase (475 IU/L). Subsequent investigations including endoscopic retrograde cholangiopancreatography and liver histology confirmed the diagnosis fo PSC. Treatment with a low dose of prednisolone for 2 months and ursodeoxycholic acid during 32 months of follow-up resulted in clinical remission and halted disease progression. A high index of suspicion is necessary for physicians to diagnose this disorder in children with chronic liver disease. Our experience in this case indicates that therapy with prednisolone and ursodeoxycholic acid may be helpful for the treatment of PSC in children, and suggests the need for more trials of combined therapy.

[Molecular typing of Taiwanese Orientia tsutsugamushi isolates by restriction fragment profile]

Scrub typhus, which is caused by Orientia tsutsugamushi, is one of the reportable diseases in Taiwan, ROC. Positive cases seemed to be increasing in recent years and our laboratory had confirmed a total of 247 cases in 1997. In this study, 71 strains of O. tsutsugamushi were isolated from heparinized blood of the patients by cell culture, and their DNA was isolated. Two-step polymerase chain reaction was then used to amplify a specific sequence from the DNA, which was digested with restriction enzymes, Hha I and Sfa NI, for typing. With this technique, 34 strains gave rise to the same profile as that of the Kuroki type, 6 as the Karp type and 2 as the Gilliam type. The remaining 28 strains produced fragment profiles different from those of types Karp, Kato, Kawasaki, Kuroki, Gilliam and Shimokoshi and, therefore, were classified as 6 new types designated Taiwan A to Taiwan F, respectively. These strains with profiles different from those of the standard Japanese strains may represent the local mutant strains.

[Immunohistochemical study of the expression of fucosylated glycoconjugates in human lung carcinoma]

Lewis X, Sialyl Lewis X and Sialyl Dimeric Lewis X are three fucosylated glycoconjugates on cell surface. With immunohistochemical method, the expression of the three structures in the original lung cancer tissues (with or without metastasis), adjacent tissues and metastatic lesions of lung carcinoma were studied. It was found that the three antigens were expressed with different intensity on the cell surface and in the cytoplasm of the lung carcinoma cell. However, there was no or only trace expression of these antigens in the adjacent tissues of lung carcinoma and normal lung tissues. Moreover, the original lesions of lung carcinoma with metastasis and/or poor differentiation expressed higher level of the three antigens than those without metastasis and/or with well or medium differentiation. Sialyl Lewis X was considered to be more closely related to the metastatic ability and differentiation of the lung carcinoma cell than the other two antigens, Lewis X and Sialyl Dimeric Lewis X. Furthermore, in the lymph nodes with lung carcinoma cell metastasis, there were expression of the three antigens with different degree, while in those lymph nodes without lung carcinoma cell metastasis, there was no expression of the three antigens.

Differential reactivity of the rat S100A4(p9Ka) gene to sodium bisulfite is associated with differential levels of the S100A4 (p9Ka) mRNA in rat mammary epithelial cells

Elevated intracellular levels of S100A4, an S100-related calcium-binding protein, induce metastatic capability in benign mammary tumor-derived epithelial cells and in transgenic mice bearing oncogene-induced benign mammary tumors. The S100A4(p9Ka) gene in rat mammary epithelial cells expressing low levels of S100A4 yields a reduced number of fragments upon digestion with the methylation-sensitive restriction enzyme, HpaII, compared with the gene from high S100A4-expressing cells. Genomic sequencing of two potential regulatory elements in the S100A4 gene, an intronic enhancer and TATA box region, revealed that in low S100A4-expressing cells, most cytosine bases exhibited high levels of resistance to conversion to thymine by sodium bisulfite. In derivative cell lines, which express high levels of S100A4, only a small number of cytosine bases were resistant to treatment with sodium bisulfite. In contrast, cytosine bases in the DNA surrounding an upstream regulatory region, which binds inhibitory GC factor in the low-expressing cell lines, are sensitive to conversion to thymine by sodium bisulfite in both low- and high-expressing cell lines. The results suggest that the rat S100A4 gene is maintained in a different state in the low-expressing cell lines and that this state might be a consequence of the pattern of methylation in this regulated gene that does not contain a CpG island.

Alteration in transcripting the gene encoding the delta-opioid receptor in rat brain is not underlying the development of tolerance to [D-Ala2,D-Leu5] enkephalin

Previous study has demonstrated that chronic treatment of [D-Ala2,D-Leu5] enkephalin (DADLE) induces profound down-regulation of delta opioid receptor in rat brain. We further examined whether this down-regulation of receptor was due to a decrease in the transcription of gene encoding delta-opioid receptor (DOR-1). Rats received daily i.c.v. injection of DADLE for 1, 3, or 5 days and developed significant tolerance to the antinociceptive effect of DADLE after one-day treatment. We measured the level of mRNA in rat brain tissues using in situ hybridization. No significant changes in the mRNA levels of the cortex, striatum, hippocampus, and thalamus on any examined days were found as compared to those of rats received sham operation only. There is only a transient decrease of DOR-1 mRNA level in midbrain region that occurred after a three-day treatment. Thus, the result of this study did not suggest that alteration in transcription of gene-encoding delta-opioid receptor was responsible for the down-regulation of delta-opioid receptor associated with the development of tolerance to DADLE.