Regulation of Fc gamma receptor subtype expression on a human eosinophilic leukemia cell line EoL-3: participation of cAMP and protein kinase C in the effects of interferon-gamma and phorbol ester

We investigated the effects of interferon-gamma (IFN-gamma), phorbol myristate acetate (PMA), and dibutyryl cAMP (Bt2cAMP) on Fc gamma R subtype expression on a human eosinophilic leukemia cell line, EoL-3. Unstimulated EoL-3 cells expressed Fc gamma RII as determined by monoclonal antibody (mAb) IV-3, whereas there was little or no Fc gamma RI and Fc gamma RIII expression as determined by mAbs 32.2 and 3G8, respectively. IFN-gamma induced Fc gamma RI expression, and Bt2 cAMP, which did not induce Fc gamma RI expression by itself, showed an additive effect on IFN-gamma-induced Fc gamma RI expression. Fc gamma RII expression was augmented by IFN-gamma, PMA, and Bt2 cAMP. Bt2 cAMP also showed an additive effect on IFN-gamma-augmented Fc gamma RII expression. Fc gamma RIII expression could be induced only by IFN-gamma plus Bt2 cAMP. H-7, a protein kinase C (PK-C) inhibitor, suppressed the enhancement of Fc gamma R subtype expression induced by these reagents. These results show that Fc gamma R subtype expression on EoL-3 cells is regulated differently in each subtype and that cAMP and PK-C play important roles in the regulation.

Growth regulation of a human mature B cell line, B104, by anti-IgM and anti-IgD antibodies

An EBNA- human B lymphoma cell line, B104, was established. B104 cells express IgD as well as IgM on their surface, which is thought to be a basic characteristic of mature B cells. The growth of B104 cells was inhibited by treatment with a panel of anti-IgM antibodies. Cell cycle analyses revealed that the transition of B104 cells from the G2/M to the G0/G1 phase of the cell cycle was markedly inhibited by treatment with anti-IgM antibodies. Progression of B104 cells to the M phase of the cell cycle was found to be suppressed in the presence of anti-IgM antibodies. In contrast, both the entrance of G0/G1 phase cells into the S phase and the progression of S phase cells to the G2/M phase of the cell cycle did not seem to be inhibited significantly by treatment with anti-IgM antibodies. These results indicate that the mechanism of the inhibition of growth of B104 cells by anti-IgM antibodies is blockage of the transition from the G2 to the M phase of the cell cycle. In contrast to anti-IgM antibodies, anti-IgD antibodies could not cause growth inhibition of B104 cells at all. B cell growth factors such as IL-4 and IL-6 had no effect on the inhibition of growth of B104 cells by anti-IgM antibody. IFN-alpha and -beta, which have no B cell growth factor activity, did increase the number of cells that survived the treatment with anti-IgM antibodies. B104 is an excellent experimental model for the study of the mechanism of signal transduction through sIg as well as the functional difference between sIgM and sIgD.

Growth regulation of a human mature B cell line, B104, by anti-IgM and anti-IgD antibodies

An EBNA- human B lymphoma cell line, B104, was established. B104 cells express IgD as well as IgM on their surface, which is thought to be a basic characteristic of mature B cells. The growth of B104 cells was inhibited by treatment with a panel of anti-IgM antibodies. Cell cycle analyses revealed that the transition of B104 cells from the G2/M to the G0/G1 phase of the cell cycle was markedly inhibited by treatment with anti-IgM antibodies. Progression of B104 cells to the M phase of the cell cycle was found to be suppressed in the presence of anti-IgM antibodies. In contrast, both the entrance of G0/G1 phase cells into the S phase and the progression of S phase cells to the G2/M phase of the cell cycle did not seem to be inhibited significantly by treatment with anti-IgM antibodies. These results indicate that the mechanism of the inhibition of growth of B104 cells by anti-IgM antibodies is blockage of the transition from the G2 to the M phase of the cell cycle. In contrast to anti-IgM antibodies, anti-IgD antibodies could not cause growth inhibition of B104 cells at all. B cell growth factors such as IL-4 and IL-6 had no effect on the inhibition of growth of B104 cells by anti-IgM antibody. IFN-alpha and -beta, which have no B cell growth factor activity, did increase the number of cells that survived the treatment with anti-IgM antibodies. B104 is an excellent experimental model for the study of the mechanism of signal transduction through sIg as well as the functional difference between sIgM and sIgD.

Analysis of IgG immune complexes in sera from patients with membranous nephropathy: role of IgG4 subclass and low-avidity antibodies

The levels of circulating immune complexes (CIC) were determined using an anti-C3d binding assay in patients with various types of glomerulonephritis (GN). It was found that IgG class CIC were positive in 20% (7/35) of patients with idiopathic membranous nephropathy (MN) and in 80% (8/10) of patients with lupus glomerulonephritis (LN). Of these patients, IgG4 subclass CIC were observed more frequently in 29% of MN and 60% (3/5) of minimum change nephrotic syndrome, and, with less amounts, in 10% (1/10) of membranoproliferative GN (MPGN) and 20% (2/10) of IgA nephropathy. On the other hand, the patients with LN showed a lower positivity (30%) of IgG4-CIC as compared with that of IgG-CIC. In the comparison of mean levels, only MN patients showed significantly higher value than normal individuals (p less than 0.05). In patients with MN, the CIC of the other IgG subclasses (IgG1, IgG2, IgG3) were not significantly elevated and their positivities were low (9-11%). The study on the salt-dependent dissociability of CIC, which is considered to reflect the avidity of antibodies in CIC, showed that the IgG-CIC of 11 of 15 patients with MN were dissociable to various extents even at the physiological concentration. These findings suggested that IgG4 subclass specificity and low avidity may be pathogenic characteristics of IgG-CIC in certain populations of patients with MN.

Hepatitis B virus mutants with precore-region defects in two babies with fulminant hepatitis and their mothers positive for antibody to hepatitis B e antigen

Clones of hepatitis B virus (HBV) DNA were propagated from sera of two babies who developed neonatal fulminant hepatitis B, as well as from sera of their mothers who carried HBV with antibody to hepatitis B e antigen, and the precore-region sequences were determined. A point mutation from guanine to adenine, converting codon 28 for tryptophan (TGG) to a stop codon (TAG), was detected in 18 of 20 HBV DNA clones from mother and all 31 clones from baby in one family, and invariably in 55 clones from mother and three clones from baby in the other family. These results indicate that HBV mutants defective in the precore region in some carrier mothers with antibody to hepatitis B e antigen may transmit fulminant hepatitis B to their babies.

Defects in the precore region of the HBV genome in patients with chronic hepatitis B after sustained seroconversion from HBeAg to anti-HBe induced spontaneously or with interferon therapy

Hepatitis B virus DNA clones were propagated from sera of six patients with chronic hepatitis B who seroconverted from HBeAg to antibody to HBeAg either spontaneously or after administration of alpha-interferon. Defects in the precore region blocking synthesis and secretion of HBeAg were detected in all 46 hepatitis B virus DNA clones from three patients who remained positive for antibody to HBeAg and in whom hepatitis resolved. Defective clones had point mutations from guanine to adenine at nucleotide 83 in the precore region, converting codon 28 from tryptophan (TGG) to a stop codon (TAG). In contrast, this defect was not found in any of 39 hepatitis B virus DNA clones from three patients who seroconverted to antibody to HBeAg but then redeveloped HBeAg with reactivation of hepatitis. Using these results, the G-to-A point mutation at nucleotide 83 in the precore region would predict sustained positivity for antibody to HBeAg and remission of hepatitis in patients who have seroconverted either spontaneously or with interferon therapy.

Ketotifen inhibits PAF-induced actin polymerization in a human eosinophilic leukaemia cell line, EoL-1

The inhibitory effect of ketotifen on platelet activating factor (PAF)-induced actin polymerization in a human eosinophilic leukaemia cell line, EoL-1, was examined by flow cytometry with the use of reagents specific for the filamentous form of actin (F-actin). Actin polymerization has been considered to be essential for locomotion of cells, chemotaxis and chemokinesis, and thus it reflects the chemotactic reaction of EoL-1 cells stimulated by PAF. Unstimulated EoL-1 cells showed little PAF-induced actin polymerization, whereas EoL-1 cells cultured for 9 days with the supernatant of a human ATL cell line, HIL-3 (HIL-3 sup), showed marked actin polymerization when stimulated with PAF. The actin polymerization in EoL-1 cells induced by PAF was seen in a dose-dependent manner at concentrations of 10(-10) M to 10(-6) M of PAF, and the maximum effect was seen at 10(-7) M of PAF. CV-3988, a specific antagonist of PAF, inhibited 80% of the actin polymerization in EoL-1 cells induced by PAF at a concentration of 10(-5) M. Ketotifen inhibited up to 40% of the PAF-induced actin polymerization of EoL-1 cells in a dose-dependent manner at concentrations of 10(-9) M to 10(-5) M. These results suggest that ketotifen may play an important role in the prevention of eosinophil-induced inflammation in allergic disorders by inhibiting PAF-induced chemotaxis of eosinophils.

Defects in the precore region of hepatitis B virus DNA in a plasma pool from carriers seropositive for antibody against e antigen and with infectivity in chimpanzees

A plasma pool from 12 asymptomatic carriers seropositive for antibody against hepatitis B e antigen (anti-HBe) contained hepatitis B virus (HBV) with chimpanzee infectious doses of 1-100/mL, and another pool from 12 carriers positive for hepatitis B e antigen (HBeAg) contained 10(8)/mL doses or more. The HBeAg-positive pool contained 10(6)-fold more HBV DNA than the anti-HBe-positive pool, reflecting the difference in infectivity in chimpanzees. The precore region sequences of HBV DNA in the two plasma pools were amplified by polymerase chain reaction, and separate HBV DNA clones were propagated for determining the nucleotide sequence. Of 114 clones from the anti-HBe-positive pool, 113 displayed a point mutation from guanine to adenine at nucleotide 83 in the precore region, which converted codon 28 for tryptophan (TGG) to a stop codon (TAG), and the remaining clone had a point mutation from adenine to cytosine at the first letter of codon 1 (CTG) to inhibit the translation initiation of the precore region. Precore region defects, in contrast, were observed in only 10 (8%) of 119 clones from the HBeAg-positive pool. These results indicate the infectious capacity of HBV mutants, defective in the precore region and incapable of directing the synthesis and secretion of HBeAg, which prevail in the circulation of hosts after they seroconvert from HBeAg to anti-HBe.

Ketotifen inhibits PAF-induced actin polymerization in a human eosinophilic leukaemia cell line, EoL-1

The inhibitory effect of ketotifen on platelet activating factor (PAF)-induced actin polymerization in a human eosinophilic leukaemia cell line, EoL-1, was examined by flow cytometry with the use of reagents specific for the filamentous form of actin (F-actin). Actin polymerization has been considered to be essential for locomotion of cells, chemotaxis and chemokinesis, and thus it reflects the chemotactic reaction of EoL-1 cells stimulated by PAF. Unstimulated EoL-1 cells showed little PAF-induced actin polymerization, whereas EoL-1 cells cultured for 9 days with the supernatant of a human ATL cell line, HIL-3 (HIL-3 sup), showed marked actin polymerization when stimulated with PAF. The actin polymerization in EoL-1 cells induced by PAF was seen in a dose-dependent manner at concentrations of 10(-10) M to 10(-6) M of PAF, and the maximum effect was seen at 10(-7) M of PAF. CV-3988, a specific antagonist of PAF, inhibited 80% of the actin polymerization in EoL-1 cells induced by PAF at a concentration of 10(-5) M. Ketotifen inhibited up to 40% of the PAF-induced actin polymerization of EoL-1 cells in a dose-dependent manner at concentrations of 10(-9) M to 10(-5) M. These results suggest that ketotifen may play an important role in the prevention of eosinophil-induced inflammation in allergic disorders by inhibiting PAF-induced chemotaxis of eosinophils.

Common and subtypic determinants of hepatitis B surface antigen particles: susceptibility to reduction and/or alkylation evaluated with monoclonal antibodies

The specificity of five monoclonal antibodies, three raised against hepatitis B surface antigen (HBsAg) particles and two against envelope polypeptides, was tested for on a panel of 366 sera containing HBsAg of various subtypes (131 adw, 146 adr, 39 ayw and 50 ayr). Three monoclonals bound to HBsAg irrespective of subtypes, and therefore, were directed to the common antigenic determinants of HBsAg. Of these, two raised against particles (No. 824 and No. 7922) did not bind with reduced HBsAg particles. The other raised against peptides (No. 5124) bound to reduced HBsAg particles. It did not, however, bind to reduced and alkylated HBsAg particles, thereby indicating that it was directed to an epitope involving cysteine residues not contributing to the conformation. The remaining two monoclonals were directed to subtypic determinants not identical to any of d, y, w and r determinants. The subtypic determinant detectable by one of them (No. 4403), raised against HBsAg polypeptides, markedly increased after reduction of HBsAg particles with or without alkylation. In contrast, the subtypic determinant, detectable by the other monoclonal (No. 2155) raised against particles, substantially decreased after reduction. Non-identity of common or subtypic determinants detectable by the five monoclonals were established by blocking tests in which labeled antibody was competed by non-labeled antibody, of a homologous or heterologous specificity, for the binding with HBsAg. These monoclonals would be useful in studies for immunochemical configuration of HBsAg particles and epidemiology of novel subtypic determinants.

Transforming growth factor beta and dexamethasone suppress the expression of Fc epsilon receptor 2 (CD23) on a human eosinophilic cell line EoL-3

The effects of interferon-alpha (IFN-alpha), INF-gamma, transforming growth factor beta (TGF-beta) and dexamethasone on low-affinity Fc receptors for IgE (Fc epsilon R2/CD23) expression on a human eosinophilic leukemia cell line, Eol-3, were examined. Fc epsilon R2/CD23 expression was enhanced by both IFN-alpha and IFN-gamma, and suppressed by TGF-beta and dexamethasone. Northern blot analysis revealed that these reagents regulate the Fc epsilon R2/CD23 expression from mRNA level: both IFN-alpha and IFN-gamma increased the amount of Fc epsilon R2/CD23 mRNA, while both dexamethasone and TGF-beta decreased Fc epsilon R2/CD23 mRNA, where the effect of dexamethasone was much stronger than that of TGF-beta. In comparison with IFN-alpha, IFN-gamma seemed to enhance preferentially the release of surface Fc epsilon R2/CD23, which resulted in the increase of soluble Fc epsilon R2/CD23. These results suggest that these reagents may play important regulatory roles in allergy and in helminth infections via their effects on Fc epsilon R2/CD23 expression on eosinophils.

Agranulocytosis following infectious mononucleosis

A girl developed acute agranulocytosis (45/mm3), 37 days after the onset of infectious mononucleosis. The bone marrow showed myeloid hyperplasia with maturation arrest and erythroid hypoplasia. A normal amount of colony forming units of granulocytes and macrophages (CFU-GM) colonies with a relative high number of clusters was observed. Neither anti-neutrophil antibodies nor circulating inhibitors of colony growth were found in serum. Granulocyte and macrophage colony stimulating factor (GM-CSF) activity in the patient's serum rose at this time. The agranulocytosis lasted 5 days and her clinical state soon improved. These results suggested that agranulocytosis was presumably not due to serum factors, including auto-antibodies and/or suppressive substances, and that Epstein-Barr virus (EBV) had some direct or indirect effect on the marrow cells of the myeloid series.

The 5'-terminal sequence of the hepatitis C virus genome

The 5'-terminal sequence of the genome of hepatitis C virus (HCV) was determined for two distinct HCV strains in human and chimpanzee carriers. It had a 5'-noncoding region of at least 324 nucleotides, well preserved by the two strains with a high homology (99.1%), followed by 1348 nucleotides that continued to the documented sequence of prototype HCV spanning 7310 nucleotides (European Patent Application #88310922.5). Based on these results, HCV is considered to possess an uninterrupted open reading frame encoding at least 2886 amino acid residues. Two structural genes were postulated on the 5'-terminal sequence of the HCV genome. One gene in the upstream region, highly conserved by the two strains at the amino acid level and rich in basic amino acids such as arginine, appeared to encode the viral capsid protein. The other gene in the downstream region was divergent between the two strains at both nucleotide and amino acid levels. It coded for nine potential N-glycosylation sites, and was considered to encode the viral envelope protein. Disclosure of the 5'-terminal sequence of the HCV genome would facilitate its taxonomic classification, and contribute toward immunological diagnosis of infection and development of vaccines.

Hepatitis B surface antigen particles with all four subtypic determinants: point mutations of hepatitis B virus DNA inducing phenotypic changes or double infection with viruses of different subtypes

Hepatitis B surface antigen (HBsAg) particles carry the common determinant, a, as well as d or y and w or r subtype determinants, and are classified into the four major subtypes, i.e., adw, adr, ayw and ayr. Rare sera contain HBsAg particles with all four subtype determinants (adywr). Target sequences (nucleotides 38-550) in the S gene of hepatitis B virus (HBV) DNA in two such sera were amplified by the polymerase chain reaction. Individual amplification products were cloned in an M13 phage vector. The HBV DNA clones obtained were subtyped by determining the second letters of codon 122 and 160 for lysine (AAA/AAG) or arginine (AGA/AGG), which specify the d or y and w or r determinants, respectively. From one serum (S-63), two adw, 10 adr and 58 ayr clones were obtained. When the two adw clones and two representatives each of the adr and ayr clones were compared against each other, for the sequence of 235 base pairs representing nucleotides 295-529 in the S gene, they differed only by 0.4-2.1% (average 1.2%). These results indicated multiple point mutations of a single HBV strain of subtype ayr and co-infection of hepatocytes with the original HBV strain and its mutant of subtype adw as the mechanism for the production of HBsAg/adywr particles. From the other serum (K-45), 1 adw, 73 adr and 4 ayw clones were obtained. The adw clone and two representative adr clones differed only by 0-1.7% in the S gene sequences, but they differed by 8.5% or greater from two representative ayw clones. HBsAg/adywr particles in this serum, therefore, could be explained by double infection of hepatocytes with two HBV strains of different subtypes (adr and ayw).

Subtyping hepatitis B virus DNA in free or integrated forms by amplification of the S-gene sequences by the polymerase chain reaction and single-track sequencing for adenine

The S-gene fragments of hepatitis B virus (HBV) DNA in serum, or integrated in chromosomes of human hepatoma cells (PLC/PRF/5), were amplified by the polymerase chain reaction, cloned into an M13 phage vector, and then sequenced only for adenine. The subtype determinant d or y was established by the presence or absence of adenine as nucleotide 365, and w or r by that of nucleotide 479 in the S gene. The results were identical with those obtained by enzyme immunoassay with monoclonal antibodies. A high sensitivity for the detection of HBV DNA, amplified by the polymerase chain reaction, allowed subtyping of HBV in sera containing HBsAg in concentrations too low to be subtyped by immunological methods. Furthermore, subtyping at the nucleotide level can be applied to tissues containing HBV DNA sequences in integrated forms, such as hepatocellular carcinomas, stored frozen or in formalin.

Trans-complementation of the C gene of human and the P gene of woodchuck hepadnaviruses

A 5 bp insertion was introduced into the BstEII site at nucleotide 2815 in DNA of hepatitis B virus (HBV) and a mutant HBV genome was produced, which coded for envelope and core proteins, but not for DNA polymerase, due to a frameshift. Cultured hepatoma cells (HepG2) were simultaneously transfected with a plasmid harbouring a tandem dimer of the mutant HBV DNA and another plasmid harbouring a tandem dimer of DNA of woodchuck hepatitis virus or duck hepatitis B virus. The replication of mutant HBV DNA, incapable of encoding DNA polymerase, was accomplished by cotransfecting woodchuck hepatitis virus DNA, but not by duck hepatitis B virus DNA. These results indicated a trans-complementation of the C and P genes in mammalian hepadnaviruses beyond a species barrier.

Hepatitis B viruses with precore region defects prevail in persistently infected hosts along with seroconversion to the antibody against e antigen

The C gene of hepatitis B virus (HBV) codes for a nucleocapsid protein made of 183 amino acid residues and is preceded in phase by the precore (pre-C) region, encoding 29 residues. The pre-C-region product is required for the synthesis and secretion of hepatitis B e antigen (HBeAg), which is made of the C-terminal 10 amino acid residues of the pre-C-region product and the N-terminal 149 residues of the C-gene product. HBV mutants with pre-C-region defects prevailed in the circulation of three asymptomatic carriers as they seroconverted from HBeAg to the corresponding antibody (anti-HBe), and these mutants finally replaced nondefective HBV. HBV DNA clones were propagated from sera of an additional 15 carriers with anti-HBe and sequenced for the pre-C region. Essentially all HBV DNA clones (56 of 57 [98%]) revealed mutations that prohibited the translation of a functional pre-C-region product. A point mutation from G to A at nucleotide 83, converting Trp-28 (TGG) to a stop codon (TAG), was by far the commonest and was observed in HBV DNA clones from 16 (89%) of 18 carriers seropositive for anti-HBe. In addition, there were point mutations involving ATG codon to abort the translation initiation of the pre-C region, as well as deletion and insertion to induce frameshifts. Such mutations leading to pre-C-region defects were rarely observed in persistently infected individuals positive for HBeAg or in patients with type B acute hepatitis after they had seroconverted to anti-HBe. These results would indicate a selection of pre-C-defective mutants in persistently infected hosts, along with seroconversion to anti-HBe, by immune elimination of hepatocytes harboring nondefective HBV with the expression of HBeAg.

Prediction of the development of atopic symptoms in early childhood by cord IgE-binding factors (soluble Fc epsilon R2)

The relationship of cord serum sFc epsilon R2 levels to the development of atopic symptoms in early childhood was studied. Cord sFc epsilon R2 was 444.2 +/- 235.1 pg/ml (n = 77), which was not significantly different from maternal serum sFc epsilon R2 (541.7 +/- 346.9 pg/ml, n = 42). However, there was no correlation between cord and maternal serum sFc epsilon R2, suggesting that most, if not all, of cord serum sFc epsilon R2 was produced by the fetus itself. Cord serum sFc epsilon R2 in infants who developed atopic symptoms later was significantly higher than that in infants who were free of atopic symptoms (P less than 0.01 at 7 and 13 months of age). The incidence of the development of atopic symptoms increased with the increase of cord serum sFc epsilon R2. These results suggest that sFc epsilon R2 is related to the development of atopic disorders and that the measurement of cord serum sFc epsilon R2 may be of value in predicting the development of atopic disorders in early childhood.

Gamma-interferon production in response to hepatitis B core protein and its synthetic peptides in patients with chronic hepatitis B virus infection

The nucleocapsid of hepatitis B virus (HBV) is an efficient immunogen in activating T cells to produce interferon-gamma (IFN-gamma) in patients with chronic HBV infection. We investigated hepatitis B core antigen (HBcAg)-specific T cell recognition, which seems to be implicated in the pathogenesis of chronic liver disease. IFN-gamma production by peripheral-blood mononuclear cells of patients with chronic HBV infection [25 patients with chronic active hepatitis (CAH) and 14 asymptomatic carriers of HBV (ASCs)] was measured by an enzyme-linked immunosorbent assay. P19 polypeptide, which is derived from recombinant HBcAg particle (rHBcAg), increased IFN-gamma production in patients with CAH, but its effect was weaker than that of rHBcAg. P19 had no stimulating effect on T cells from ASCs. The fine specificity of T cell recognition of HBcAg was examined using 8 kinds of synthetic peptides. T cells from the patients who responded against P19 polypeptide recognized the sites within the common sequences of HBcAg and HBeAg (p72-90, P90-99, P108-122 and P126-146). These results suggest that HBcAg and P19 are cross-reactive at the T cell level, and that these T cells recognize the sites within the common sequences of HBcAg and HBeAg in HBV-infected patients.

Regulation of Fc gamma receptor expression and phagocytosis of a human monoblast cell line U937. Participation of cAMP and protein kinase C in the effects of IFN-gamma and phorbol ester

We investigated the positive and negative effects of IFN-gamma, PMA, dibutyryl cAMP (Bt2cAMP), dexamethasone and transforming growth factor-beta (TGF-beta) on Fc gamma R subtype expression and phagocytosis of a human monoblast cell line, U937. IFN-gamma increased and Bt2cAMP decreased Fc gamma RI expression determined by a mAb 32.2, whereas PMA and Bt2cAMP increased Fc gamma RII expression determined by a mAb IV-3. Phagocytosis was measured microscopically by counting ingested aggregated human IgG- or BSA-treated ox E (Eo'-IgG or Eo'-BSA). IFN-gamma increased the phagocytosis of Eo'-IgG but not that of Eo'-BSA, and PMA increased the phagocytosis of both Eo'-IgG and Eo'-BSA. Bt2cAMP decreased both basal and IFN-gamma- and PMA-augmented phagocytosis of U937 cells. Dexamethasone also inhibited both basal and IFN-gamma-augmented Fc gamma RI expression and PMA-augmented Fc gamma RII expression and phagocytosis, but did not affect IFN-gamma-augmented phagocytosis of Eo'-IgG. The augmentation of phagocytosis of Eo'-IgG by IFN-gamma thus seems to be due mainly to the increased internalizing process rather than to increased Fc gamma RI expression. TGF-beta slightly decreased Fc gamma R expression. In a study of the participation of protein kinase C (PK-C), it was found that H-7, a PK-C inhibitor, did not inhibit either IFN-gamma- or PMA-enhanced Fc gamma RI and Fc gamma RII expression, respectively, and 1-oleoyl-2-acetylglycerol and N-(6-phenylhexyl)-5-chloro-1-naphthalenesulfonamide, both PK-C activators, did not show any apparent increase in Fc gamma R expression and phagocytosis. These results show that Fc gamma RI and Fc gamma RII expression on U937 cells is regulated by different mechanisms and that IFN-gamma and PMA play their roles in Fc gamma R expression and phagocytosis by different pathways. It is possible that cAMP but not PK-C plays an important role in the regulation of Fc gamma R expression and phagocytosis.

Regulation of Fc gamma receptor expression and phagocytosis of a human monoblast cell line U937. Participation of cAMP and protein kinase C in the effects of IFN-gamma and phorbol ester

We investigated the positive and negative effects of IFN-gamma, PMA, dibutyryl cAMP (Bt2cAMP), dexamethasone and transforming growth factor-beta (TGF-beta) on Fc gamma R subtype expression and phagocytosis of a human monoblast cell line, U937. IFN-gamma increased and Bt2cAMP decreased Fc gamma RI expression determined by a mAb 32.2, whereas PMA and Bt2cAMP increased Fc gamma RII expression determined by a mAb IV-3. Phagocytosis was measured microscopically by counting ingested aggregated human IgG- or BSA-treated ox E (Eo'-IgG or Eo'-BSA). IFN-gamma increased the phagocytosis of Eo'-IgG but not that of Eo'-BSA, and PMA increased the phagocytosis of both Eo'-IgG and Eo'-BSA. Bt2cAMP decreased both basal and IFN-gamma- and PMA-augmented phagocytosis of U937 cells. Dexamethasone also inhibited both basal and IFN-gamma-augmented Fc gamma RI expression and PMA-augmented Fc gamma RII expression and phagocytosis, but did not affect IFN-gamma-augmented phagocytosis of Eo'-IgG. The augmentation of phagocytosis of Eo'-IgG by IFN-gamma thus seems to be due mainly to the increased internalizing process rather than to increased Fc gamma RI expression. TGF-beta slightly decreased Fc gamma R expression. In a study of the participation of protein kinase C (PK-C), it was found that H-7, a PK-C inhibitor, did not inhibit either IFN-gamma- or PMA-enhanced Fc gamma RI and Fc gamma RII expression, respectively, and 1-oleoyl-2-acetylglycerol and N-(6-phenylhexyl)-5-chloro-1-naphthalenesulfonamide, both PK-C activators, did not show any apparent increase in Fc gamma R expression and phagocytosis. These results show that Fc gamma RI and Fc gamma RII expression on U937 cells is regulated by different mechanisms and that IFN-gamma and PMA play their roles in Fc gamma R expression and phagocytosis by different pathways. It is possible that cAMP but not PK-C plays an important role in the regulation of Fc gamma R expression and phagocytosis.

[Clinical studies on cefixime in pediatrics]

Clinical usefulness of cefixime (CFIX), a new oral cephalosporin antibiotic, in pediatric field was investigated. The results obtained were summarized as follows. 1. The clinical efficacy of CFIX was investigated in a total of 138 children including 49 with upper respiratory tract infections (RTI), 22 with acute bronchitis, 18 with pneumonia, 19 with scarlet fever and 21 with urinary tract infections (UTI). 2. Clinical effectiveness was excellent in 58, good in 60, fair in 14 and poor in 3, with an overall efficacy rate of 87.4%. The efficacy rate classified according to types of infection were 85.7% in upper RTI, 89.5% in acute bronchitis, 94.4% in pneumonia, 78.9% in scarlet fever, and 90.5% in UTI. 3. Out of the suspected causative organisms, 43 strains of a total of 50 strains isolated were eradicated. The bacteriological eradication rate was 86.0%. (Haemophilus influenzae 100%, Haemophilus parainfluenzae 100%, Streptococcus pyogenes 88.5%, Escherichia coli 85.7%). 4. One hundred forty four children were analyzed for side effect. Side effects were observed in 2 children (1.4%) with diarrhea in 1 and anorexia in another. Abnormal laboratory test results were recorded in 4 children (3.3%). The above results suggest that CFIX is a very useful new oral cephalosporin for the treatment of bacterial infections in children.

Combined hepatitis B immune globulin and vaccine for postexposure prophylaxis of accidental hepatitis B virus infection in hemodialysis staff members: comparison with immune globulin without vaccine in historical controls

Twenty-three staff members serving in a hemodialysis unit were exposed accidentally to needlestick contaminated with blood containing hepatitis B surface antigen and hepatitis B e antigen, as well as high levels of DNA polymerase activity (greater than 100 cpm). They received hepatitis B vaccine (20 micrograms) simultaneously with hepatitis B immune globulin (5 ml, 200 IU per ml) within 48 hr after the exposure, and the vaccination was repeated at 1 and 3 months. The protective efficacy was compared with that in a past study in the same unit in which 33 members were given hepatitis B immune globulin alone within 48 hr after the exposure to blood with similarly high levels of DNA polymerase activity. No differences were noted in age or sex between the staff members who were vaccinated and those who were not, nor were there any differences between their inocula in the titers of hepatitis B virus markers. During 12 months after the accident, only one (4%) of the 23 vaccinated members contracted hepatitis B virus infection, at a frequency significantly lower than 11 (33%) of the 33 members who did not receive vaccine (p less than 0.02). These results indicate that hepatitis B vaccine, when given in combination with hepatitis B immune globulin, is efficacious for postexposure immunoprophylaxis of accidental infection.

Regulation of Fc epsilon receptor 2 (CD23) expression on a human eosinophilic cell line EoL3 and a human monocytic cell line U937 by transforming growth factor beta

Regulation of low-affinity receptors for IgE (Fc epsilon R2/CD23) on a human eosinophilic cell line EoL3 and a human monocytic cell line U937 was studied using an anti-Fc,R2/CD23 monoclonal antibody H107 by flow cytometry. While platelet-activating factor, interleukin 4, and interferon gamma significantly augmented Fc epsilon R2/CD23 expression on both cell lines, transforming growth factor beta (TGF beta) inhibited both the basal level of Fc epsilon R2/CD23 expression and the enhanced Fc epsilon R2/CD23 expression induced by these reagents in dose- and time-dependent manners. However, TGF beta did not significantly suppress the high basal level of Fc epsilon R2/CD23 expression on RPMI 8866 cells. These results suggest that Fc epsilon R2/CD23 expression on EoL3 and U937 cells is regulated by various cytokines and growth factors, and that TGF beta plays an important regulatory role in IgE-mediated immune responses.

Differential regulation of the low affinity Fc receptor for IgE (Fc epsilon R2/CD23) and the IL-2 receptor (Tac/p55) on eosinophilic leukemia cell line (EoL-1 and EoL-3)

Two types of activation Ag, low affinity FcR for IgE (Fc epsilon R2)/CD23 and IL-2R (Tac/p55), were expressed and differently regulated on human eosinophilic leukemia cell lines (EoL-1 and EoL-3). Because the binding of IgE on EoL-3 cells was completely inhibited by H107 (anti-Fc epsilon R2/CD23 mAb) but not by irrelevant mAb, essentially all the low affinity Fc epsilon R2 on EoL-3 seemed to be the Fc epsilon R2/CD23 molecules. Both IL-4 and IFN-gamma enhanced the surface expression of Fc epsilon R2, whereas IL-1, IL-2, and IL-5 showed no effects, as determined by surface staining with anti-Fc epsilon R2 antibody (H107). In contrast to Fc epsilon R2 up-regulation, IL-4 and IFN-gamma showed a differential effect on the regulation of IL-2R (Tac/p55). Whereas IFN-gamma up-regulated the receptor expression of IL-2R/Tac, IL-4 did not. The result suggests that these lymphokines are involved in the different aspects of the activation pathway of the eosinophils. The possible role of Fc epsilon R2 and IL-2R on the function of eosinophils in allergic reaction is discussed.

Soluble low affinity Fc receptors for IgE in the serum of allergic and nonallergic children

IgE-binding factors are thought to have regulatory activity in in vitro IgE synthesis. To obtain evidence of the participation of IgE-binding factors in in vivo IgE synthesis, the serum level of low affinity Fc receptors for IgE (sFc epsilon RII) (IgE-BFs) was examined in 41 nonallergic children and in 37 allergic children whose serum IgE levels were significantly higher than those of nonallergic children. The serum level of sFc epsilon RII showed a marked age-dependent variation. It was highest in infants and then decreased gradually with age. The serum level of sFc epsilon RII in allergic children was significantly higher than that of nonallergic children in early childhood (1128.0 +/- 323.8 vs 777.3 +/- 227.0 pg/ml, p less than 0.01 in infants (less than 1 y) and 851.8 +/- 270.0 vs 579.4 +/- 197.1 pg/ml, p less than 0.05 in children aged 1-2 y) but not in older children (3-15 y). Three allergic infants (less than 1 y) with serum sFc epsilon RII levels higher than the mean + 1 SD (1451.8 pg/ml) of all allergic infants (less than 1 y) had serum IgE levels (geometric mean 125.9 IU/ml) significantly higher than the other seven allergic infants (less than 1 y) (geometric mean 5.6 IU/ml, p less than 0.05). A close positive correlation between the serum level of sFc epsilon RII and the absolute number of Fc epsilon RII(+) peripheral blood lymphocytes was observed (Spearman's rank correlation coefficient = 0.79, p less than 0.001 in 27 allergic and Spearman's rank correlation coefficient = 0.72, p less than 0.001 in 19 nonallergic children). In conclusion, serum sFc epsilon RII may be derived mainly from Fc epsilon RII(+) lymphocytes, and may have relationship to the increased production of IgE in early childhood (0-2 y).

Differential regulation of the low affinity Fc receptor for IgE (Fc epsilon R2/CD23) and the IL-2 receptor (Tac/p55) on eosinophilic leukemia cell line (EoL-1 and EoL-3)

Two types of activation Ag, low affinity FcR for IgE (Fc epsilon R2)/CD23 and IL-2R (Tac/p55), were expressed and differently regulated on human eosinophilic leukemia cell lines (EoL-1 and EoL-3). Because the binding of IgE on EoL-3 cells was completely inhibited by H107 (anti-Fc epsilon R2/CD23 mAb) but not by irrelevant mAb, essentially all the low affinity Fc epsilon R2 on EoL-3 seemed to be the Fc epsilon R2/CD23 molecules. Both IL-4 and IFN-gamma enhanced the surface expression of Fc epsilon R2, whereas IL-1, IL-2, and IL-5 showed no effects, as determined by surface staining with anti-Fc epsilon R2 antibody (H107). In contrast to Fc epsilon R2 up-regulation, IL-4 and IFN-gamma showed a differential effect on the regulation of IL-2R (Tac/p55). Whereas IFN-gamma up-regulated the receptor expression of IL-2R/Tac, IL-4 did not. The result suggests that these lymphokines are involved in the different aspects of the activation pathway of the eosinophils. The possible role of Fc epsilon R2 and IL-2R on the function of eosinophils in allergic reaction is discussed.

[Clinical evaluation of cefodizime in children]

Cefodizime (THR-221, CDZM), a new parenteral cephalosporin, was evaluated for its efficacy and safety in 20 children with bacterial infections (Table 1), and the following results were obtained. 1. CDZM was administered in 3 or 4 divided doses at daily dosages ranging from 54.5 to 84.2 mg/kg administered by 30 minutes drip infusion or intravenous injection to 20 patients (7 cases of acute tonsillitis, 6 cases of pneumonia, 2 cases each of bronchitis and suppurative cervical lymphadenitis, and 1 case each of acute pharyngitis, acute enteritis and furunculosis) and the following clinical results were obtained: excellent, 7 cases; good, 11 cases; fair, 2 cases. The overall efficacy rate was 90% (Table 4). 2. MICs of CDZM against 15 strains of isolated organisms are shown in Table 2. MICs against all 7 strains of Haemophilus influenzae were less than 0.025 micrograms/ml. MIC against 1 out of 5 strains of Streptococcus pneumoniae was 0.05 micrograms/ml and those against 2 strains were 0.10 micrograms/ml and against the other 2 were 0.20 micrograms/ml. MICs against 3 strains of Staphylococcus aureus were 1.56, 25 and higher than 100 micrograms/ml, respectively. 3. No clinical adverse reaction was observed in any of the 20 patients. Eosinophilia was observed in 2 cases. A slight elevation of S-GOT was found in 1 patient (case No. 8) and moderate elevation of S-GOT and S-GPT in another (case No. 18) (Table 4). In case No. 18, the S-GOT and S-GPT activity improved after the administration of the drug was stopped.(ABSTRACT TRUNCATED AT 250 WORDS)

DiGeorge syndrome with hypogammaglobulinaemia: a patient with excess suppressor T cell activity treated with fetal thymus transplantation

A male infant with DiGeorge syndrome had hypogammaglobulinaemia with a normal number of B cells. CD3(+) T cells were reduced and the CD4(+)/CD8(+) ratio was reversed. Proliferative responses of T cells to mitogens and to allogeneic cells were low. The pokeweed mitogen (PWM)-induced B cell differentiation assay revealed a higher than normal suppressor T cell activity. This suggests that some T cells had differentiated into functionally mature cells resulting in an imbalance of regulatory T cell functions and that excess suppressor activity might play a role in hypogammaglobulinaemia. Fetal thymus transplantation improved both cellular and humoral immunity. The patient's susceptibility to viral and bacterial infections, proliferative response of T cells and serum Ig concentration returned to normal. The excess suppressor activity seen before transplantation disappeared. Hypocalcaemia did not improve. These results show that fetal thymus transplantation was effective not only in reconstituting cellular immunity but also in normalizing the imbalance of regulatory T cell functions in this patient with DiGeorge syndrome.

Antigenic sites on the arginine-rich carboxyl-terminal domain of the capsid protein of hepatitis B virus distinct from hepatitis B core or e antigen

The capsid protein of hepatitis B virus (P19) is made of 183 amino acids and carries the antigenic sites of hepatitis B core antigen (HBcAg) and hepatitis B e antigen (HBeAg) on the amino-terminal domain. The carboxyl-terminal domain of P19 (amino acids 150-183) is arginine-rich (47%) and faces the interior of the nucleocapsid for the binding with DNA. Monoclonal antibody was raised against an antigenic site on this protamine-like region of P19, which was distinct from HBcAg or HBeAg sites, and the novel antigenic site(s) was provisionally designated as hepatitis B inner core antigen (HBicAg). When P19 in a low concn (150 ng/ml) was immobilized on the solid surface, HBicAg sites were preserved, while HBcAg or HBcAg sites were no longer available on it. This allowed the detection of antibodies against HBicAg (anti-HBic), by sandwiching them between immobilized P19 and anti-IgG labeled with horseradish peroxidase. Anti-HBic was detected in sera from HBsAg carriers, typically those seropositive for antibody to HBeAg. A synthetic arginine-rich decapeptide, with a sequence of Arg-Arg-Arg-Gly-Arg-Ser-Pro-Arg-Arg-Arg, representing amino acids 150-159 of P19 and conserved in the majority of reported hepatitis B virus, absorbed the activity to bind with P19 in seven (44%) out of 16 sera containing anti-HBic. These results indicate that the decapeptide carries an HBicAg epitope and the remaining amino acid sequence of the arginine-rich carboxyl terminal domain (160-183) may be responsible for the other HBicAg epitopes.

[Clinical evaluation of sulbactam/ampicillin in children]

Sulbactam/Ampicillin (SBT/ABPC), a combination at a fixed ratio of ABPC and SBT which is an irreversible inhibitor of beta-lactamase in a 2:1 ratio, was clinically evaluated for its efficacy and safety in 24 patients with ages from 5 month-old to 12 years old with bacterial infection. The results obtained are summarized as follows. 1. A pharmacokinetic study following 30 mg/kg SBT/ABPC administration by 30 minutes drip infusion or intravenous bolus injection showed that mean half-lives of SBT and ABPC were 48.9 minutes and 40.2 minutes, respectively, and mean urinary excretion rates of SBT and ABPC in the first 6 hours were 67.1% and 48.3%, respectively. 2. SBT/ABPC was administered to 14 patients with bronchopneumonia, 4 patients with tonsillitis, a patient each with acute upper respiratory infection, with submandibular lymphadenitis, with phlegmon, with enterocolitis, with pyelonephritis and with cystitis at a daily dosage of 88.2-133.3 mg/kg, divided into 3 or 4, by intravenous bolus injection or by 30 minutes drip infusion. Clinical responses of the 24 patients were as follows: excellent: 17 patients, good: 7 patients. The efficacy rate was 100%. 3. Neither clinical adverse reactions nor abnormal laboratory test values, except slight eosinophilia in a patient and an elevation of GOT, GPT in another were observed. 4. MICs of SBT/ABPC against 7 strong beta-lactamase producing strains isolated from some of the patients were as follows. MIC against a strain of Staphylococcus aureus was 3.13 micrograms/ml, MICs against 2 out of 5 strains of Branhamella catarrhalis were 0.10 microgram/ml and those of the remaining 3 strains were 0.20 microgram/ml. MIC against a strain of Haemophilus parainfluenzae was 3.13 micrograms/ml. 5. These data described above show that SBT/ABPC has excellent bactericidal capacity against beta-lactamase producing bacteria as well as beta-lactamase non-producing Gram-positive and negative bacteria and suggest that SBT/ABPC is a very useful antibiotic for pediatric patients.

Interferon and (2'-5')oligoadenylate enhance the expression of low affinity receptors for IgE (Fc epsilon R2/CD23) on the human monoblast cell line U937

The regulation of low affinity IgE receptor (Fc epsilon R2/CD23) expression on the human monoblast cell line U937 was examined by an anti-Fc epsilon R2/CD23 monoclonal antibody (H107) and the cDNA probe for Fc epsilon R2/CD23. Alpha interferon (IFN-alpha) and its intracellular mediator, (2'-5')oligoadenylate (2, 5-A), induced Fc epsilon R2/CD23 expression on U937 with no significant increase of the Fc epsilon R2/CD23 mRNA. PMA and IFN-gamma increased both surface Fc epsilon R2/CD23 expression and the Fc epsilon R2/CD23 mRNA levels. IFN-alpha effectively induced 2, 5-A synthetase activity in U937 cells, whereas IFN-gamma induced little. The results suggest that the mechanisms of enhancement of Fc epsilon R2/CD23 expression on U937 cells by IFN-alpha and IFN-gamma are different and that 2, 5-A may play an important role in the Fc epsilon R2/CD23 expression on U937 cells induced by IFN-alpha.

[Clinical evaluation of clarithromycin in pediatric patients]

A clinical evaluation of clarithromycin (TE-031, A-56268), a newly synthesized macrolide antibiotic, was made for its efficacy and safety in 30 patients with ages ranging from 8 month-old to 12 year- 2 month-old with mycoplasmal and bacterial infections. The obtained results are summarized below. 1. A pharmacokinetic study following oral administration of TE-031 at 10 mg/kg (granule) or 5.5 mg/kg (tablet) resulted in blood concentrations and urinary recovery rates higher than with other macrolides. 2. TE-031 was administered orally to 5 patients with Mycoplasma pneumonia, 21 patients with pneumonia or bronchopneumonia, 2 patients with pertussis and 2 patients with enterocolitis at daily dosages ranging 11.1-31.6 mg/kg divided into 3. Clinical evaluations of these 30 patients were as follows; excellent: 19 patients, good: 11 patients. The efficacy rate was 100%. 3. Neither clinical adverse reaction nor abnormal laboratory data was found in any of these 30 patients. 4. MICs of TE-031 against 10 strains of bacteria isolated from 10 patients with pneumonia or bronchopneumonia were as follows. MICs against 3, 2 and 2 out of 7 strains of Streptococcus pneumoniae were less than 0.025 microgram/ml, 0.05 microgram/ml and 0.10 microgram/ml, respectively. MIC against a strain of Haemophilus influenzae was 3.13 micrograms/ml. MICs of 2 strains of Branhamella catarrhalis were 0.20 microgram/ml. 5. TE-031 is considered to be a new useful and safe antibiotic in pediatric patient with an excellent bactericidal capacity.

The loss of subtypic determinants in alleles, d/y or w/r, on hepatitis B surface antigen

Hepatitis B surface antigen possesses the group-specific determinant called a and one or another member from each of two pairs of allelic determinants, d and y as well as w and r, thereby creating the four major subtypes, adw, adr, ayw and ayr. In the sequence of major surface antigen polypeptides made of 226 amino acid residues, lysine or arginine at amino acid position 122 specifies d or y determinant, and lysine or arginine at position 160 specifies w or r determinant, respectively. By means of site-directed mutagenesis and expression of mutant genes in cultured cells, the mechanism for the loss of subtypic determinants on surface antigens was investigated at the molecular level. A rare sample of surface antigen of subtype ad, devoid of w or r determinant, had asparagine at position 160. When it was converted to lysine, the surface antigen of subtype adw was obtained. Two samples of surface antigen were subtyped as ar. They lacked d determinant, despite having lysine at position 122 which usually specified it. They differed from all reported sequences of surface antigen in amino acid 144 or 145. They displayed d determinant when amino acid 144 was converted from glutamic acid to aspartic acid, or when amino acid 145 was changed from alanine to glycine. These results indicate that the key amino acid residue at position 122 or 160 is indispensable for the expression of subtypic determinants and that some distant residues are also crucially involved in conforming them.

Immunodeficiency associated with selective loss of helper/inducer T cells and hypogammaglobulinaemia in a child with intestinal lymphangiectasia

A patient with intestinal lymphangiectasia (IL) was studied for his immunological abnormalities. The patient had hypoproteinaemia with severe hypogammaglobulinaemia. The results of lymphocyte subpopulation studies revealed a decrease of CD4+ cells and a decrease of surface immunoglobulin (sIg)-positive B lymphocytes. T cell functions determined by the proliferative responses against Concanavalin A (Con A) or phytohaemagglutinin (PHA) and by delayed type cutaneous hypersensitivity (DTH) response to purified protein derivatives (PPD) and PHA were normal. No immunoglobulin (Ig)-secreting cells were induced when his peripheral blood lymphocytes (PBL) were cultured with pokeweed mitogen (PWM). His T cells showed suppressor function to the PWM-induced differentiation of normal B cells. This suppressor activity was sensitive to 3000 rads irradiation. His B cells also failed to differentiate into Ig-producing cells with the help of normal T cells and PWM. Thus, in this patient, the decrease of Ig-synthesis in vitro could be attributed to suppressor T cells, lack of T helper cells and an intrinsic B cell defect. Therefore, this patient appears to have immunological abnormalities which differ from previously reported IL patients.

Hepatitis B surface antigen with an excess or deficiency in subtypic determinants in sera from asymptomatic carriers in Japan

Using the solid-phase enzyme immunoassay with monoclonal antibodies, hepatitis B surface antigen (HBsAg) was subtyped in sera from 5082 asymptomatic carriers who donated blood units at regional blood centers in Japan. Among them, 5004 sera contained HBsAg of a regular subtype, i.e., adw, adr, ayw or ayr, while 74 contained HBsAg with excessive subtypic determinants, such as adyw, adyr, adwr, aywr, or adywr. The presence of subtypic determinants on the selfsame particle was ascertained by sandwiching HBsAg between two monoclonal antibodies of distinct subtypic specificities. The remaining 4 sera contained HBsAg that possessed only one subtypic determinant, such as ad, ar or aw. HBsAg particles of atypical subtypes would have been given rise to by a point mutation in the S gene involving the codons regulating subtypic specificities.

Low burst-promoting activity (BPA) production by cord mononuclear cells is due to functional immaturity of monocytes

Cord blood mononuclear cells produced lower burst-promoting activity (BPA) than adult peripheral blood mononuclear cells when stimulated with phytohemagglutinin (PHA). In order to examine the cellular basis of the low production of BPA by PHA-stimulated cord blood mononuclear cells in the context of the functional immaturity of T cells or monocytes, we studied BPA production by T cells or monocytes from cord blood and adult peripheral blood. Cord T cells produced as much BPA as adult T cells. Monocytes themselves did not produce significant BPA at the concentration used in this experiment (1 x 10(5)/ml). BPA production by adult T cells was significantly enhanced by the presence of autologous monocytes. BPA production by cord T cells was also enhanced by the presence of adult monocytes but not by that of cord monocytes. Cord monocytes did not enhance BPA production by adult T cells either. These results indicate that cord monocytes are primarily responsible for the low BPA production by PHA-stimulated cord mononuclear cells.

[Clinical evaluation of sultamicillin fine granules in pediatric patients]

The clinical efficacy and the safety of sultamicillin (SBTPC) fine granules, which is a semisynthetic beta-lactam antibiotic for oral use with ester linked ampicillin (ABPC) and sulbactam (SBT), a beta-lactamase inhibitor, in a ratio of 1:1, were evaluated in 31 patients with ages from 6 months old to 10 years and 4 months old with various bacterial infections. The results obtained are summarized as follows. 1. In a pharmacokinetic study with a dose level of 10 mg/kg SBTPC, serum levels reached a peak in 1 hour after oral administration, with peak levels of 3.94 micrograms/ml for ABPC and 4.08 micrograms/ml for SBT. Half-lives of ABPC and SBT were 64.8 minutes and 63.6 minutes, respectively. The urinary excretion of ABPC over 6 hours was 66.2% and that of SBT was 60.4%. 2. SBTPC fine granules were administered orally to 1 patient with bronchitis, 9 patients with bronchopneumonia, 7 patients with tonsillitis, 4 patients with scarlet fever, 1 patient each with pharyngitis, otitis media, purulent parotitis, and urinary tract infection and 6 patients with skin and soft tissue infections at daily dosage levels of 26.1-31.6 mg/kg divided into 3 or 4. Clinical evaluations of these 31 patients were as follows, excellent: 20 patients, good: 10 patients, poor: 1 patient. The efficacy rate was 96.8%. 3. Diarrhea was observed in a patient with otitis media on the fifth day of SBTPC administration. No other clinical adverse reaction was observed in any of the remaining 30 patients. No abnormal laboratory data was found in any of 23 patients who were subjected to laboratory examinations for safety.(ABSTRACT TRUNCATED AT 250 WORDS)

Typing hepatitis B virus by homology in nucleotide sequence: comparison of surface antigen subtypes

The complete nucleotide sequences of the DNA of three hepatitis B virus (HBV) genomes of subtype adw, cloned from plasma samples of asymptomatic carriers living in the mainland and Okinawa Prefecture of Japan and Indonesia were determined. All three comprised 3215 bp and differed in sequence by only 3.9 to 5.6%. When these isolates were compared with the reported sequences of two HBV genomes of the same subtype derived from American carriers, however, the differences were greater (8.3 to 9.3% to an extent comparable with the nucleotide divergence between an HBV genome of subtype adw and that of a heterotypic subtype, such as adr, ayw or ayr. A total of 18 HBV genomes of various subtypes, including the three described here, 10 reported previously and five unpublished ones, were classified into four groups based on an inter-group divergence in nucleotide sequence of 8% or greater: group A (two adw genomes), group B (four adw), group C (three adw, four adr and one ayr) and group D (four ayw). Thus, the nine genomes of HBV subtype adw were distributed into three groups with considerably different sequences. These results indicate that the four major antigenically defined subtypes of envelope polypeptide do not reflect true genotypic variation of HBV. The fact that d to y, as well as w to r, subtypic change can be induced by an A----G point mutation at nucleotides 365 and 479 in the S gene, respectively, supports this view.

Typing hepatitis B virus by homology in nucleotide sequence: comparison of surface antigen subtypes

The complete nucleotide sequences of the DNA of three hepatitis B virus (HBV) genomes of subtype adw, cloned from plasma samples of asymptomatic carriers living in the mainland and Okinawa Prefecture of Japan and Indonesia were determined. All three comprised 3215 bp and differed in sequence by only 3.9 to 5.6%. When these isolates were compared with the reported sequences of two HBV genomes of the same subtype derived from American carriers, however, the differences were greater (8.3 to 9.3% to an extent comparable with the nucleotide divergence between an HBV genome of subtype adw and that of a heterotypic subtype, such as adr, ayw or ayr. A total of 18 HBV genomes of various subtypes, including the three described here, 10 reported previously and five unpublished ones, were classified into four groups based on an inter-group divergence in nucleotide sequence of 8% or greater: group A (two adw genomes), group B (four adw), group C (three adw, four adr and one ayr) and group D (four ayw). Thus, the nine genomes of HBV subtype adw were distributed into three groups with considerably different sequences. These results indicate that the four major antigenically defined subtypes of envelope polypeptide do not reflect true genotypic variation of HBV. The fact that d to y, as well as w to r, subtypic change can be induced by an A----G point mutation at nucleotides 365 and 479 in the S gene, respectively, supports this view.

Antibody against the translation product of the pre-S2 region of hepatitis B virus and the resolution of infection after accidental needlestick exposure

During a 5-yr period before the introduction of post-exposure immunoprophylaxis of hepatitis B virus (HBV), 363 medical personnel contracted infection after exposure to a contaminated needlestick. Among them, five (1.4%) developed a persistent carrier state, and they were followed for antibodies against translation product of the pre-S2 region (anti-pre-S2) by the enzyme immunoassay with native viral polypeptides. The consecutive seven cases in whom infection was terminated served as controls. In the acute phase, the levels of IgM and IgG anti-pre-S2 were significantly higher in the seven in whom infection resolved than in the five in whom infection persisted (mean sample:normal ratio, 11.1 +/- 4.4 vs 2.0 +/- 1.3 and 8.7 +/- 7.0 vs 3.0 +/- 1.1, respectively, p less than 0.05). In convalescence, 6 months after the normalization of serum transaminase, IgG anti-pre-S2 was detected in a high titer in the staff members with resolved infection (27.4 +/- 38.5), but was not detectable in those with persistent infection. On the basis of these observations, the intensity of humoral antibody response against the pre-S2 region product is closely correlated with the resolution of infection after exposure to HBV, and anti-pre-S2 persists in the circulation much longer than previously reported.

Antibodies to translation products of the pre-S1 and pre-S2 regions of the envelope gene of hepatitis B virus in fulminant hepatitis B

Sera from 11 patients with fulminant hepatitis B were tested for antibodies to translation products of the pre-S1 and pre-S2 regions of hepatitis B virus of IgM, IgA and IgG classes, as well as of IgA1, IgA2 and SIgA, with solid-phase enzyme immunoassays using native viral polypeptides. Antibodies to pre-S1 region product of IgM and/or IgA class were detected invariably in six patients who still had detectable hepatitis B surface antigen in serum at the time of clinical presentation. The remaining five patients who had lost HBsAg at presentation had antibodies to pre-S region products of various immunoglobulin classes in higher titers. The five patients with fulminant hepatitis without HBsAg had higher levels of IgA antibodies to pre-S region products than the seven patients with nonfulminant acute hepatitis B who had lost HBsAg: IgA antibody to pre-S1 region product (75.6 +/- 63.8 vs. 2.9 +/- 3.2, p less than 0.01) and IgA antibody to pre-S2 region product (28.9 +/- 25.3 vs. 4.2 +/- 6.9, p less than 0.01). IgA antibodies to pre-S1 and pre-S2 region products were invariably polymeric in fulminant hepatitis B. These findings are compatible with the hypothesis that a heightened humoral antibody response to pre-S1 and pre-S2 region products occurs early during the course of fulminant hepatitis B, participating in severe hepatic injury and early clearance of virus characteristic of this disease.

Regulation of Fc epsilon R2/CD23 gene expression by cytokines and specific ligands (IgE and anti-Fc epsilon R2 monoclonal antibody). Variable regulation depending on the cell types

The regulation of human low affinity FcR for IgE (Fc epsilon R2/CD23) and the soluble Fc epsilon R2 [IgE binding factor (BF)] of monocyte (U937), T (ED), and B (JIJOYE) cell lines was examined by anti-Fc epsilon R2 mAb (H107, Mab176) and the cDNA probe for Fc epsilon R2. The effect of IL-4 and IFN-gamma on Fc epsilon R2 regulation was variable among these three cell lines. IL-4 and IFN-gamma enhanced the Fc epsilon R2 gene expression and the production of Fc epsilon R2 and IgE-BF on U937, whereas IL-4 and IFN-gamma had no significant effect on the Fc epsilon R2 expression on ED. On JIJOYE, IL-4 enhanced the Fc epsilon R2 and IgE-BF production on both protein and mRNA levels. In U937 and JIJOYE cells, there was a marked increase of Fc epsilon R2 mRNA after combined stimulation with IFN-gamma and IL-4. However, in JIJOYE cells, there was a dissociation between the surface expression of Fc epsilon R2 and Fc epsilon R2 mRNA treated with IFN-gamma plus IL-4. In these cells. IFN-gamma even down-regulated the IL-4-induced expression of surface Fc epsilon R2. Stimulation of JIJOYE cells with both IFN-gamma and IL-4 resulted in the increase of the IgE-BF in the supernatant, suggesting that IFN-gamma enhanced the release of IgE-BF from Fc epsilon R2. The results indicated that Fc epsilon R2 and IgE-BF expression is regulated by IFN-gamma at least on two different levels: on transcriptional levels and the levels of cleavage of the surface Fc epsilon R2 to release soluble Fc epsilon R2 (IgE-BF). Ligands binding to the Fc epsilon R2 such as IgE and anti-Fc epsilon R2 mAb enhanced the surface expression of Fc epsilon R2 on these Fc epsilon R2(+) cell lines. This was mainly due to the surface accumulation of the receptors on JIJOYE and U937. However, the stimulation of ED by H107 and anti-Fc epsilon R2 mAb significantly enhanced the mRNA expression, indicating that Fc epsilon R2 synthesis may also be up-regulated by the specific ligands in some cell types.

Regulation of Fc epsilon R2/CD23 gene expression by cytokines and specific ligands (IgE and anti-Fc epsilon R2 monoclonal antibody). Variable regulation depending on the cell types

The regulation of human low affinity FcR for IgE (Fc epsilon R2/CD23) and the soluble Fc epsilon R2 [IgE binding factor (BF)] of monocyte (U937), T (ED), and B (JIJOYE) cell lines was examined by anti-Fc epsilon R2 mAb (H107, Mab176) and the cDNA probe for Fc epsilon R2. The effect of IL-4 and IFN-gamma on Fc epsilon R2 regulation was variable among these three cell lines. IL-4 and IFN-gamma enhanced the Fc epsilon R2 gene expression and the production of Fc epsilon R2 and IgE-BF on U937, whereas IL-4 and IFN-gamma had no significant effect on the Fc epsilon R2 expression on ED. On JIJOYE, IL-4 enhanced the Fc epsilon R2 and IgE-BF production on both protein and mRNA levels. In U937 and JIJOYE cells, there was a marked increase of Fc epsilon R2 mRNA after combined stimulation with IFN-gamma and IL-4. However, in JIJOYE cells, there was a dissociation between the surface expression of Fc epsilon R2 and Fc epsilon R2 mRNA treated with IFN-gamma plus IL-4. In these cells. IFN-gamma even down-regulated the IL-4-induced expression of surface Fc epsilon R2. Stimulation of JIJOYE cells with both IFN-gamma and IL-4 resulted in the increase of the IgE-BF in the supernatant, suggesting that IFN-gamma enhanced the release of IgE-BF from Fc epsilon R2. The results indicated that Fc epsilon R2 and IgE-BF expression is regulated by IFN-gamma at least on two different levels: on transcriptional levels and the levels of cleavage of the surface Fc epsilon R2 to release soluble Fc epsilon R2 (IgE-BF). Ligands binding to the Fc epsilon R2 such as IgE and anti-Fc epsilon R2 mAb enhanced the surface expression of Fc epsilon R2 on these Fc epsilon R2(+) cell lines. This was mainly due to the surface accumulation of the receptors on JIJOYE and U937. However, the stimulation of ED by H107 and anti-Fc epsilon R2 mAb significantly enhanced the mRNA expression, indicating that Fc epsilon R2 synthesis may also be up-regulated by the specific ligands in some cell types.

IgE receptor-bearing lymphocytes in allergic and nonallergic children

Using a monoclonal anti-human IgE receptor (Fc epsilon R) antibody, the percentage of Fc epsilon R(+) cells among peripheral blood lymphocytes in children with or without allergic disorders was determined. The percentage of Fc epsilon R(+) cells in 63 nonallergic children was 4.3 +/- 1.5%, which did not vary with age and was equal to that of adults (4.2 +/- 1.2%). Allergic younger children (0-2 yr) showed a significantly higher percentage of Fc epsilon R(+) cells (7.7 +/- 3.0%) than nonallergic younger children (0-2 yr) (4.0 +/- 1.3%, p less than 0.001). Similarly, in allergic younger children, serum IgE levels (geometric mean = 58.9 IU/ml) were also significantly higher than those of nonallergic younger children (geometric mean = 2.0 IU/ml) (p less than 0.01). A positive correlation between the percentages of Fc epsilon R(+) cells and serum IgE levels was observed (Spearman rank = 0.88, p less than 0.01] in eight allergic younger children (0-2 yr) with serum IgE levels higher than 100 IU/ml. The increase in the percentage of Fc epsilon R(+) cells in allergic younger children (0-2 yr) was not a secondary phenomenon caused by serum IgE because serum IgE levels in these children were much lower than the concentration at which IgE enhance Fc epsilon R expression on lymphocytes. In conclusion, Fc epsilon R(+) lymphocytes may play a regulatory role in IgE synthesis in allergic younger children (0-2 yr).

Postnatal changes in plasma burst-promoting activity (BPA) levels in preterm infants

Two-stage cell culture assays were used to determine burst-promoting activity (BPA) levels in the plasma of untransfused premature infants during the early anaemic period. The plasma BPA levels decreased during the early phase of the postnatal fall in haemoglobin and the mean plasma BPA levels at 2 and 4 weeks of age were significantly lower (24 +/- 9% and 20 +/- 14%) than those of normal adults (53 +/- 17%). After 8 weeks of age, plasma BPA levels increased markedly in correlation with the recovery of erythropoiesis. Inhibitors of erythroid colony growth were not significantly elevated in the plasma of premature infants. These results suggest that BPA may act as a regulator of erythropoiesis in preterm infants along with erythropoietin.