A monoclonal anti-idiotype specific for human polyclonal IgM rheumatoid factor

One of the hallmarks of rheumatoid arthritis (RA) is the production of high titers of rheumatoid factor (RF) antibody directed against the Fc portion of IgG. Anti-Id that recognize the majority of monoclonal RF from patients with B cell dyscrasias are reactive with only 1 to 2% of these polyclonal RF from RA patients. We describe a new monoclonal anti-Id, 4C9, that recognizes a L chain determinant on polyclonal IgM RF from patients with RA but does not recognize a panel of monoclonal RF from patients with B cell malignancies. 4C9 reactivity is found in the serum of 34/43 RF-positive RA patients and in 12/12 RF-positive synovial fluids, but in only 1/14 RF-negative sera from RA patients and 1/22 sera containing monoclonal IgM RF. 4C9 reactivity is highly enriched in purified IgM RF from nine RA patients and represents a variable percentage of total IgM RF up to a maximum of 23%. Furthermore, 4C9 reactivity is enriched in the synovial fluid of three of five RA patients compared with serum, suggesting that 4C9-reactive IgM RF are synthesized within the joint. IgG RF from RA synovial fluids are not 4C9 reactive, indicating either that different genes are used to encode IgM and IgG RF in RA patients, or that IgG RF have somatically mutated away from idiotypic reactivity.

A monoclonal anti-idiotype specific for human polyclonal IgM rheumatoid factor

One of the hallmarks of rheumatoid arthritis (RA) is the production of high titers of rheumatoid factor (RF) antibody directed against the Fc portion of IgG. Anti-Id that recognize the majority of monoclonal RF from patients with B cell dyscrasias are reactive with only 1 to 2% of these polyclonal RF from RA patients. We describe a new monoclonal anti-Id, 4C9, that recognizes a L chain determinant on polyclonal IgM RF from patients with RA but does not recognize a panel of monoclonal RF from patients with B cell malignancies. 4C9 reactivity is found in the serum of 34/43 RF-positive RA patients and in 12/12 RF-positive synovial fluids, but in only 1/14 RF-negative sera from RA patients and 1/22 sera containing monoclonal IgM RF. 4C9 reactivity is highly enriched in purified IgM RF from nine RA patients and represents a variable percentage of total IgM RF up to a maximum of 23%. Furthermore, 4C9 reactivity is enriched in the synovial fluid of three of five RA patients compared with serum, suggesting that 4C9-reactive IgM RF are synthesized within the joint. IgG RF from RA synovial fluids are not 4C9 reactive, indicating either that different genes are used to encode IgM and IgG RF in RA patients, or that IgG RF have somatically mutated away from idiotypic reactivity.

Interaction between oligodendroglia and immune cells: mitogenic effect of an oligodendrocyte precursor cell line on syngeneic T lymphocytes

We analyzed cellular interactions between T lymphocytes and a recently established immortal glial line, L3 that retains several properties of immature oligodendrocytes (Aloisi et al., J Neurosci Res 27:16-24, 1990). L3 oligodendrocytes (L3-OL) cannot be induced to express class II antigens, nor do they specifically present antigen to syngeneic specific T lymphocyte. However, L3-OL strongly enhance the proliferation of freshly activated, interleukin-2(IL-2)-dependent T-line lymphocytes and concanavalin A (ConA)-activated lymphoblasts, irrespective of their antigen specificity or surface phenotype (CD4+ or CD8+). Resting and some activated T cells were susceptible to the mitogenic effect of L3-OL only in the presence of exogenous IL-2, not of other cytokines. The mitogenic effect of L3-OL did not depend on cell viability. It was observed in paraformaldehyde-fixed L3-OL cells and in membrane preparations, but not in culture supernatant. Neither intact L3-OL cells nor membrane preparations had direct IL-2 activity. The conclusion that the mitogenic effect of L3-OL cells is exerted by membrane structures acting as a costimulatory factor(s) of IL-2 is supported by the finding that it is largely blocked by a monoclonal anti-IL-2 receptor antibody. The effect is distinct from membrane-bound IL-1, membrane-bound tumor necrosis factor-alpha (TNF-alpha), IL-3, or IL-6 and cannot be reconstituted by these cytokines.

Structure-activity relationships of (+)-CC-1065 analogues in the inhibition of helicase-catalyzed unwinding of duplex DNA

(+)-CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis. Previous studies have shown that the potent cytotoxic and antitumor activities of (+)-CC-1065 are due to the ability of this compound to covalently modify DNA. (+)-CC-1065 reacts with duplex DNA to form a (N3-adenine)-DNA adduct which lies in the minor groove of DNA overlapping with a five base-pair region. As a consequence of covalent modification with (+)-CC-1065, the helix bends into the minor groove and also undergoes winding and stiffening. In the studies described here, we have constructed templates for helicase-catalyzed unwinding of DNA that contain site-directed (+)-CC-1065 and analogue DNA adducts. Using these templates we have shown that (+)-CC-1065 and select synthetic analogues, which have different levels of cytotoxicity, all produce a significant inhibition of unwinding of a 3'-tailed oligomer duplex by helicase II when the displaced strand is covalently modified. However, the extent of helicase II inhibition is much more significant for (+)-CC-1065 and an analogue which also produced DNA winding when the winding effects are transmitted in the opposite direction to the helicase unwinding activity. This observed pattern of inhibition of helicase-catalyzed unwinding of drug-modified templates was the same for a 3'-T-tail, for different duplex region sequences, and with the Escherichia coli rep protein. Unexpectedly, the gel mobility of the displaced drug-modified single strand was dependent on the species of drug attached to the DNA. Last, strand displacement by helicase II coupled to primer extension by E. coli DNA polymerase I showed the same pattern of inhibition when the lagging strand was covalently modified. In addition, the presence of helicase II on single-stranded regions of templates caused the premature termination of primer extension by DNA polymerase. These results are discussed from the perspective that (+)-CC-1065 and its analogues have different effects on DNA structure, and these resulting structural changes in DNA molecules are related to the different in vivo biological consequences caused by these drug molecules.

Synthetic peptides representing sequence 39 to 59 of rat V beta 8 TCR fail to elicit regulatory T cells reactive with V beta 8 TCR on rat encephalitogenic T cells

Subpathogenic doses of syngeneic autoreactive T cells protect experimental animals against associated autoimmune disease. Preferential use of the TCR of encephalitogenic T cells suggests that this molecule serves as the target for immunoregulation in experimental autoimmune encephalomyelitis (EAE). Whether peptides derived from the V beta 8 of the rat TCR elicit regulatory T cells and produce the same vaccinating effect against EAE as do whole T cells remains unknown. Here we show that immunization of Lewis rats with V beta 8(39-59), a peptide representing residues 39 to 59 of the rat V beta 8 TCR, does not induce the production of regulatory T cells reactive to the intact TCR V beta 8 containing this sequence. Moreover, animals that had recovered from both actively induced EAE and transferred EAE did not generate regulatory T cells that recognized the V beta 8(39-59) peptide. Further, transfusion of large doses of peptide-specific T cells did not protect the animals from EAE. Our results suggest that the V beta 8(39-59) peptide may comprise so-called cryptic epitopes, which function as immunogens only when dissociated from large protein complexes.

Immune regulation in self tolerance: functional elimination of a self-reactive, counterregulatory CD8+ T lymphocyte circuit by neonatal transfer of encephalitogenic CD4+ T cells lines

Transfer of encephalitogenic, CD4+ T lymphocyte lines into syngeneic adult Lewis rats not only leads to the development of experimental autoimmune encephalomyelitis (EAE), but, in addition, to the expansion of counterregulatory, CD8+ T lymphocyte clones which are able to lyse specifically the encephalitogenic T cells in vitro and to neutralize their encephalitogenic capacity in vivo. In striking contrast, in neonatal rats, which still lack myelin (autoantigens), injection of the same encephalitogenic lines neither mediates EAE, nor confers protection in later life against the myelin-specific T cells. In fact, this treatment results in the life-long functional elimination of counterregulatory, clonotypic CD8+ T lymphocytes, which cannot even be reinduced by repeated injections of the relevant CD4+ T line. These data seem to point to a self-protective T cell control mechanism which is developed within the immune system prior to, and thus independent of the appearance of the appropriate self antigen.

The antitumor agent CC-1065 inhibits helicase-catalyzed unwinding of duplex DNA

The antitumor drug CC-1065 is thought to exert its effects by covalent bonding to N3 of adenine in DNA and interfering with some aspect of DNA metabolism. Therefore, it is of interest to determine what effect this drug has on enzymes involved in various aspects of DNA metabolism. In this report, we examine the ability of two DNA helicases, the dda protein of phage T4 and helicase II of Escherichia coli, to unwind CC-1065-adducted, tailed, oligonucleotides. It is shown that the presence of the drug on DNA strongly inhibits unwinding catalyzed by the T4 and E. coli proteins. A significant difference between the results obtained with the two helicases is that DNAs containing drug on either the tailed or the completely duplex strands are poor substrates for helicase II but dda protein-mediated unwinding is inhibited only when the drug is on the tailed strand. The drug-modified, helicase-released, strands migrate abnormally through a native gel, suggesting that the drug traps an unusual secondary structure generated in the course of protein-mediated unwinding. A kinetic analysis of the drug-inhibited reactions reveals that the helicases are trapped by the DNA-drug complex. This is evidenced by a decrease in the rate of helicase exchange between drug-bound substrate and drug-free duplex. The implications of these results with respect to the mechanism of action of CC-1065 in vivo are discussed.

Interaction between DNA and alpha/beta-type small, acid-soluble spore proteins: a new class of DNA-binding protein

DNA in spores of Bacillus and Clostridium species is associated with small, acid-soluble proteins (SASP) of the alpha/beta type; the presence of these proteins is a major factor in causing spore resistance to UV light, alpha/beta-type SASP did not bind to single-stranded DNA, single- or double-stranded RNA, or DNA-RNA hybrids in vitro. However, these proteins bound a variety of double-stranded DNAs and conferred protection against DNase cleavage. The binding of alpha/beta-type SASP to DNA saturated at a protein/DNA ratio (wt/wt) of 4:1 to 5:1, which is approximately 1 SASP per 4 bp. alpha/beta-type SASP-DNA interaction did not require divalent cations, was independent of pH between 6 and 8, and, for some SASP-DNA pairs, was relatively insensitive to salt up to 0.3 M. The relative affinity of alpha/beta-type SASP for different DNAs was poly(dG).poly(dC) greater than poly(dG-dC).poly(dG-dC) greater than plasmid pUC19 greater than poly(dA-dT).poly(dA-dT), with poly(dA).poly(dT) giving no detectable binding. This order in alpha/beta-type SASP-DNA affinities parallels the facility with which the DNAs adopt an A-like conformation, the conformation in alpha/beta-type SASP-DNA complexes. An oligo(dG).oligo(dC) of 12 bp was bound by alpha/beta-type SASP. While a 26-bp oligo(dG).oligo(dC) bound more tightly than the 12-mer, there was no significant increase in affinity for alpha/beta-type SASP with further increase in size of oligo(dG).oligo(dC). In contrast, binding of alpha/beta-type SASP to oligo(dA-dT).oligo(dA-dT) was minimal up to at least a 70-mer, and binding to poly(dA-dT).poly(dA-dT) was very cooperative. In addition to blocking DNase digestion, binding of alpha/beta-type SASP to DNA blocked (i) cleavage of the DNA backbone by hydroxyl radicals and orthophenanthroline-Cu2+, (ii) DNA cleavage by restriction enzymes, in particular those with specificity for GC-rich sequences; and (iii) in vitro transcription of some but not all genes. However, methylation of dG residues by dimethyl sulfate was not affected by alpha/beta-type SASP binding.

Endothelium-dependent dilation to L-arginine in isolated rat skeletal muscle arterioles

The vascular actions of L-arginine (L-Arg) were studied in isolated, pressurized first-order rat cremaster muscle arterioles (93 +/- 2.9 microns) bathed in a Krebs bicarbonate-buffered solution, pH 7.4, equilibrated with 21% O2-5% CO2. Arterioles were studied before and after either the administration of NG-nitro-L-arginine (L-NNA, 10(-3) M), an inhibitor of the synthesis of endothelium-derived relaxing factor (EDRF), or the removal of the endothelium. Acetylcholine (ACh, 10(-8) and 10(-6) M), sodium nitroprusside (SNP, 10(-8) M) and phenylephrine (PE, 10(-7) M) evoked dilation and constriction, respectively. L-Arg, (10(-5)-10(-3) M) the precursor of EDRF, evoked dose-dependent arteriolar dilation; whereas D-arginine (D-Arg, 10(-5)-10(-3) M) was without any significant effect. Administration of L-NNA significantly reduced basal diameters and significantly inhibited the arteriolar dilations to both ACh and L-Arg but had no effect on the dilation to SNP. Removal of the arteriolar endothelium with air inhibited dilations to both ACh and L-Arg, had no effect on responses to SNP, and potentiated vasoconstrictor responses to PE. These findings suggest that in skeletal muscle arterioles the dilations to ACh and L-Arg are endothelium dependent and that microvascular endothelium modulates constrictor responses to PE. Thus EDRF may play an important role in the local regulation of arteriolar resistance and blood flow.

Effect of the (+)-CC-1065-(N3-adenine)DNA adduct on in vitro DNA synthesis mediated by Escherichia coli DNA polymerase

(+)-CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis. Previous studies have shown that the potent cytotoxic and antitumor activities of (+)-CC-1065 are due to the ability of this compound to covalently modify DNA. (+)-CC-1065 reacts with duplex DNA to form an N3-adenine DNA adduct which lies in the minor groove of the DNA helix overlapping with a 5-base-pair region. As a consequence of covalent modification with (+)-CC-1065, the DNA helix bends into the minor groove and also undergoes winding and stiffening [Lee, C.-S., Sun, D., Kizu, R., & Hurley, L. H. (1991) Chem. Res. Toxicol. 4, 203-213]. In the studies described here, in which we have constructed site-directed DNA adducts on single-stranded DNA templates, we have shown that (+)-CC-1065 and select synthetic analogues, which have different levels of cytotoxicity, all show strong blocks against progression of Klenow fragment, E. coli DNA polymerase, and T4 DNA polymerase. The inhibition of bypass of drug lesions by polymerase could be partially alleviated by increasing the concentration of dNTPs and, to a small extent, by increasing polymerase levels. Klenow fragment binds equally well to a DNA template adjacent to a drug modification site and to unmodified DNA. These results taken together lead us to suspect that it is primarily inhibition of base pairing around the drug modification site and not prevention of polymerase binding that leads to blockage of DNA synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of rat encephalitogenic T cells bearing non-Vβ8 T cell recepotors

In this study, we demonstrate that T cell lines specific for a synthetic peptide representing sequence 87 to 99 of myelin basic protein (MBP) are encephalitogenic in Lewis rats. However, unlike syngeneic T cells specific for MBP residues 68 to 88 which exclusively use V beta 8 in their antigen receptors, these cells do not. None of the 10 T cell lines and T hybridomas specific for MBP (87-99) used V beta 8 in their T cell receptors. Our results document for the first time that rat encephalitogenic T cells do not exclusively use V beta 8 in T cell receptors that rat encephalitogenic T cells specific for MBP (87-99) are heterogeneous and that MBP (87-99) contains at least two epitopes for rat T cells.

Effect of chromosome location of Bacillus subtilis forespore genes on their spo gene dependence and transcription by E sigma F: identification of features of good E sigma F-dependent promoters

Translational lacZ fusions to forespore genes of Bacillus subtilis were not expressed in spoIIAC (sigma F) or spoIIIE mutants when the lacZ fusions were integrated at the loci of the same genes or at the SP beta locus. However, some of these genes, including gerA, gpr, spoIIIG (sigma G), and sspE, were expressed in spoIIIE mutants and spoIIIE spoIIIG double mutants (but not in spoIIAC mutants) when the lacZ fusions were integrated at the amyE locus. When tested, the beta-galactosidase made in these mutants was found only in the forespore, and the 5' ends of the mRNAs produced in these mutants were identical to those in a Spo+ background. Analysis of the in vitro transcription of forespore genes by RNA polymerase containing sigma F (E sigma F) revealed a direct correlation between good in vitro transcription by E sigma F and expression at the amyE locus in spoIIIE mutants. This result suggests that forespore genes are transcribed by E sigma F in spoIIIE and spoIIIE spoIIIG mutants. Comparison of the promoter regions of genes transcribed well and poorly by E sigma F in vivo and in vitro showed that good transcription by E sigma F was correlated with G residues at positions -15 and -16, a purine residue at position -13, and a T residue at position -7 relative to the start site of transcription. The importance of these residues in sigma F recognition was confirmed by analysis of the E sigma F-dependent transcription in vivo and in vitro of mutant ssp genes.

Analysis of T cell receptor beta chains in Lewis rats with experimental allergic encephalomyelitis: conserved complementarity determining region 3

This study explores the usage of T cell antigen receptor (TCR) beta chain elements in Lewis rats with experimentally induced allergic encephalomyelitis (EAE). TCRs from 15 different T cell clones and hybridomas derived from animals immunized with myelin basic protein (MBP), and all having specificity for the 21-mer encephalitogenic fragment MBP 68-88, utilized V beta 8.2. In addition, there was a marked conservation of the first two amino acid residues of the junctional complementarity determining region 3 (CDR3) associated with the V beta 8.2 receptors. 12 of 15 contained an aspartic acid followed by serine regardless of the associated J beta element. At the nucleotide level, this conservation of AspSer residues was accomplished with few or no nongermline-encoded nucleotide (N) additions. A similar pattern of AspSer usage and N region nucleotide additions was observed in a number of V beta 8.2 isolates derived from MBP-immunized lymph nodes. In contrast, V beta 8.2 polymerase chain reaction amplified isolates from Lewis T cells activated with concanavalin A or from lymph nodes of complete Freund's adjuvant-immunized animals showed no AspSer utilization (0/31) in the CDR3, and four to nine N region nucleotide additions. We conclude from this finding that AspSer residues in the CDR3, limited N region nucleotide additions, along with V beta 8.2 sequences, contribute to TCR specificity for MBP 68-88. This raises the possibility that encephalitogenic, disease-causing T cells either represent a population that derives from late fetal life or alternatively, that they are rare cells with this particular TCR phenotype contributed to the T cell pool throughout adulthood and are selected by antigen. In either case, the CDR3 AspSer sequences as well as V beta 8.2 sequences are candidates for the receptor target structures recognized by regulator T cells in recovery from and resistance to active EAE. In this respect, a preliminary analysis of TCR utilization in three T cell clones specific for MBP 68-88 isolated from animals recovered from active EAE indicates that while all three use V beta 8.2, only one contains AspSer in the CDR3.

Enhanced interferon-gamma-induced Ia-antigen expression by glial cells after previous exposure to this cytokine

Encephalitogenic T cells appear capable of destroying class II major histocompatibility complex (MHC) antigen (Ia)-positive glial cells in the brain, thus accounting for the pathologic activity of these lymphocytes in experimental autoimmune encephalomyelitis (EAE). However, glial cells do not generally express Ia molecules, suggesting that regulation of Ia expression figures prominently in autoimmune diseases of the central nervous system. In studies to understand the regulatory mechanisms involved in Ia expression, a glial cell clone generated from the brains of neonatal Lewis rats (F10 clone) readily expressed class II major histocompatibility (Ia) antigens after stimulation by interferon-gamma (IFN-gamma) at doses from 10 to 100 units/ml. Level of the antigen decreased gradually within 5-7 days after cultures were depleted of the cytokine. Reexposure of the cells to the IFN-gamma at 100-fold lower doses induced a stronger Ia response than did the initial exposure. F10 cells also expressed Ia when they were cultured with small numbers of syngeneic T lymphocytes, either proliferating or nonproliferating. Proliferating T cells had direct Ia-inducing activity, whereas nonproliferating T cells had this effect only when they were added to cultures with small amounts of T cell-specific antigen. Moreover, Ia-inducing effects of IFN-gamma on F10 cells were also greatly enhanced when these cells were preexposured to T cells. Our results suggest that initial exposure to IFN-gamma or T cells enhances the Ia responsiveness of glial cells to further stimulation with the cytokine.

Effect of structural variations in cholesteryl-conjugated oligonucleotides on inhibitory activity toward HIV-1

A number of oligonucleotide analogues containing internucleoside phosphorothioate linkages and a covalently attached cholesteryl residue was synthesized and tested for activity against HIV-1 in cultures of Molt3 cells. Structural features important for high antiviral activity are the presence of a cholesteryl moiety, a run of terminal phosphorothioate groups, and the presence of nucleoside residues. An increase in length of the tether between cholesteryl and phosphorus from six to 14 atoms has no significant effect on antiviral activity, and up to one-half of the internucleoside links in a cholesteryl-conjugated phosphorothioate oligomer and one-third of the internucleoside links in a nonconjugated phosphorothioate can be replaced with phosphodiester links without much change in antiviral activity. However, replacement of nucleoside units in the oligomers by a simple analogue (-OCH2CH2CH2O-) yields inactive or very weakly active compounds, even in the presence of a cholesteryl group. Dose-response patterns for assays in which cholesteryl-conjugated oligomers are added to test cells either simultaneously or subsequently to viral infection are similar for homooligomer derivatives and for oligomers containing "antisense" sequences, suggesting a similarity in mode of action for the two classes of oligomers in this system.

CD4-CD8- splenic T cells from Lewis rats recovered from experimental autoimmune encephalomyelitis respond to encephalitogenic T cells that mediate this disorder

We previously demonstrated that encephalitogenic CD4+ T lymphocytes from the long-term cultured line S1, specific for myelin basic protein, induce a CD8+ T cell population in vivo that protects naive Lewis rats against experimental autoimmune encephalomyelitis caused by S1 cells. In order to determine the contribution of individual T cell population in the development of induced resistance, we have analyzed the in vitro proliferative capacity of phenotypically distinct T cell populations isolated from S1-immunized rats. We found that both CD8+ and CD8-CD4- T cells show striking proliferative responses when stimulated with S1 cells, whereas CD4+ T cells show only minimal responses. In addition, a significant proportion of the CD8-CD4- cells, after stimulated by S1 cells, became CD8+ and had a strong cytolytic activity toward S1 cells. These results suggest a contribution of double-negative splenic T cells in the regulatory circuit associated with autoimmune encephalomyelitis.

High-performance self-pumped phase conjugator with a multichannel in KNSBN:Cu crystal

A Cu-doped (0.04 wt. %) (K(0.5)Na(0.5))(0.2)(Sr(0.61) Ba(0.39))(0.9)Nb(2)O(6) crystal produced as much as 68% self-pumped phaseconjugate reflectivity at the laser wavelength lambda = 514.5 nm. We also observed some phenomena that helped us to understand the mechanism for the self-pumped phase-conjugate mirror.

Analysis of transcriptional control of the gerD spore germination gene of Bacillus subtilis 168

The gerD locus of Bacillus subtilis comprises a single gene whose function is essential for the germination of B. subtilis spores in media containing asparagine, glucose, and fructose. The expression of gerD has been characterized by using a chromosomal lacZ fusion to the gerD promoter. The promoter is switched on at the same time as the synthesis of glucose dehydrogenase, 2.5 h after sporulation has been initiated in the developing forespore. The gerD gene is not expressed in spoIIB or spoIIIA, -IIIB, -EIII, -FIII, or -IIIG mutants, but it is expressed in spoIIIC and -IIID and spoIVA mutant backgrounds. The in vivo transcriptional start point of the gene has been mapped by primer extension analysis, and sequences upstream from the start point show considerable homology with the promoter consensus sequences recognized by RNA polymerase containing the forespore-specific sigma factor sigma G (E sigma G). gerD is transcribed in vitro by E sigma G with a similar if not identical start point to that found in vivo, and expression of the gene can be rapidly induced in vegetative cells following the induction of sigma G synthesis. These results indicate that gerD is another member of the sigma G regulon, which includes a number of genes expressed only in the forespore compartment of sporulating cells of B. subtilis.

The causes and complications of late diagnosis of foreign body aspiration in children. Report of 210 cases

Late diagnoses of foreign body aspiration were defined as occurring beyond 3 days between the aspiration of the foreign body, or onset of symptoms, and correct diagnosis. We reviewed a total of 210 children with late diagnosis of foreign body aspiration. The causes creating late diagnosis of foreign body aspiration in children were as follows: (1) parental negligence (106/210, 50%); (2) misdiagnosis by the fellow professionals and pediatricians (39/210, 19%); (3) the normal chest roentgenographic findings (29/210, 14%); (4) lack of typical symptoms and signs (26/210, 12%); (5) mismanagement (8/210, 4%); and (6) a negative bronchoscopic finding (2/210, 1%). The most common complications encountered were obstructive emphysema (77/186, 41%), mediastinal shift (63/186, 34%), pneumonia (43/186, 24%), and atelectasis (33/186, 18%) in 186 patients who underwent a chest roentgenographic examination. The incidence of major complications was 64% (48/75) in the children who were diagnosed within 4 to 7 days; however, the complication rate was 70% (39/56) in those with a delay in diagnosis of 15 to 30 days, and 95% (20/21) in the cases with a delay in diagnosis of over 30 days after aspirating the foreign bodies.

A subset of mouse splenic macrophages can constitutively present alloantigen directly to CD8+ T cells

About a third of mouse splenic macrophage (M phi) progenitors give rise to cloned progeny that constitutively induce the selective proliferation of naive allogeneic CD8+ T cells in a CD4+ helper cell-independent manner--a response that is inhibited by mAb to the MHC class I molecules present on the M phi. Colony-mixing experiments indicated that the failure of most M phi clones to present allo-Ag was not due to their suppression of the ability of CD8+ cells to respond, nor did the nonpresenting clones interfere with the activity of the allo-Ag presenting M phi. The allo-Ag presenting phenotypes were found to be a stable characteristic in a panel of cell lines derived from individual clones of M phi. Analysis of the cell lines revealed that the differential expression of allo-APC activity could not be attributed to the levels of MHC class I molecules; rather, the cell lines and the primary M phi clones differ in their expression of a cell-associated costimulator molecule that likely functions to induce the expression of the IL-2R on and the secretion of IL-2 from the T cells.

A subset of mouse splenic macrophages can constitutively present alloantigen directly to CD8+ T cells

About a third of mouse splenic macrophage (M phi) progenitors give rise to cloned progeny that constitutively induce the selective proliferation of naive allogeneic CD8+ T cells in a CD4+ helper cell-independent manner--a response that is inhibited by mAb to the MHC class I molecules present on the M phi. Colony-mixing experiments indicated that the failure of most M phi clones to present allo-Ag was not due to their suppression of the ability of CD8+ cells to respond, nor did the nonpresenting clones interfere with the activity of the allo-Ag presenting M phi. The allo-Ag presenting phenotypes were found to be a stable characteristic in a panel of cell lines derived from individual clones of M phi. Analysis of the cell lines revealed that the differential expression of allo-APC activity could not be attributed to the levels of MHC class I molecules; rather, the cell lines and the primary M phi clones differ in their expression of a cell-associated costimulator molecule that likely functions to induce the expression of the IL-2R on and the secretion of IL-2 from the T cells.

Inhalation of foreign bodies in Chinese children: a review of 400 cases

A retrospective review of 400 Chinese children who had inhaled foreign bodies was undertaken. There has been a yearly increase in the total number of cases of airway foreign bodies removed in our hospital. Fifty-eight percent of the children presenting were from the countryside; 42% were townspeople. Approximately 90% of the patients were under 3 years of age, with the peak incidence of foreign body inhalation occurring between 1 and 2 years of age (57.8%). The male-female ratio was about 1.2:1. About 95% of the removed foreign bodies were organic in origin. The majority of the foreign bodies were found most often in the right bronchial tree (46%). A positive history of foreign body inhalation was obtained in 98% of the cases. Twenty-eight percent of the children presented at the hospital within 24 hours, 71% within 1 week, and 29% more than 1 week after inhaling the foreign body. The most common presenting symptoms of laryngotracheal foreign bodies were cough, wheezing, dyspnea, and hoarseness; those of bronchial foreign bodies were cough, wheezing, decreased air entry, and rhonchi. More than two-thirds of the children with larygotracheal foreign bodies had normal x-ray findings. The most common fluoroscopic findings in those children with bronchial foreign bodies were mediastinal shift (36.8%), obstructive emphysema (35.7%), and normal findings (35%). A total of 348 (87%) bronchial foreign bodies were removed by rigid bronchoscopy (81%), rod-lens bronchoscopy (5%), and spontaneous expulsion (1%); 52 (13%) laryngeal and tracheal foreign bodies were removed by direct laryngoscopy (12%) and tracheotomy (1%). A single endoscopic procedure successfully removed 92.5% of 400 foreign bodies detected in the airways. One child died during bronchoscopy, for a mortality rate of 0.25%.

Characterization of monoclonal antibodies against alpha-hemolysin of Escherichia coli

Monoclonal antibodies (MAbs) were raised against native and denatured alpha-hemolysin (HlyA) of Escherichia coli. Binding of the MAbs to native, denatured, and erythrocyte-complexed active wild-type hemolysin and mutant derivatives was tested. All 15 MAbs analyzed bound to native hemolysin, even when the toxin was complexed with human erythrocytes. While some MAbs were unable to bind to a specific native mutant hemolysin, others could not even bind to mutant hemolysin carrying deletions remote from their actual binding sites. A rough determination of the binding sites of 15 MAbs on HlyA was performed by Western immunoblot analysis using CNBr fragments of HlyA and mutant hemolysin proteins. Interestingly, the binding sites of the MAbs against native hemolysin seem to be more randomly distributed on HlyA than are those of MAbs against denatured hemolysin. Three MAbs inhibited the hemolytic activity significantly. Two of these MAbs bound to the hydrophobic region, and the other one bound to the repeat domain of HlyA. The use of synthetic peptides from these regions allowed determination of the linear epitopes for two of these MAbs.

Constitutive antigen presentation by mouse splenic macrophages is restricted to the progeny of a distinct progenitor population

Mouse splenic macrophage progenitors differ in their ability to give rise to cloned progeny that constitutively present complex protein antigens to T-cell hybridomas. To determine if the constitutive presentation of diverse antigens is restricted to cells derived from the same subpopulation of progenitors, we expanded macrophage clones into multiple subcultures and compared them for the ability to present different antigens to their respective antigen-specific T-cell hybridomas. Only subcultures derived from the same minority fraction of splenic macrophage progenitors were capable of constitutively presenting the antigens, and the activity of these subcultures was unaffected by the addition of recombinant murine IFN-gamma. This suggests that a specialized sub-population of constitutive antigen-presenting macrophages exists in the spleens of mice.

Determination of the structural features of (+)-CC-1065 that are responsible for bending and winding of DNA

Analysis of the anomalous migration in electrophoretic mobilities of (+)-CC-1065-modified oligomers following ligation reveals that (+)-CC-1065 induces DNA bending and winding of the helix. (+)-CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis. This drug selectively bonds covalently to N3 of adenine and lies in the minor groove of DNA, reacting in a highly sequence-selective manner. Structurally, (+)-CC-1065 consists of three subunits: two identical pyrroloindole units (subunits B and C) and a third subunit containing the DNA-reactive cyclopropane ring (subunit A). While the bonding reaction is the main determinant of DNA sequence selectivity of (+)-CC-1065, binding interactions between the inside edge substituents of the B and C subunits and the floor of the minor groove of DNA can modulate or fine tune this sequence selectivity, [Hurley, L. H., Lee, C.-S., McGovern, J. P., Mitchell, M. A., Warpehoski, M. A., Kelly, R. C., & Aristoff, P. A. (1988) Biochemistry 27, 3886-3892]. The A subunit of (+)-CC-1065 is responsible for the bending of DNA, and close van der Waals contacts between the inside edge of (+)-CC-1065 and the floor of the minor groove of DNA cause winding equivalent to about 1 base pair per alkylation site and stiffening of DNA. The magnitude of DNA bending induced by (+)-CC-1065 and related compounds is about 14-19 degrees, which is equivalent to that produced by an adenine-thymine tract of about 5-6 base pairs in length. Experiments using oligomers containing both an adenine tract and a unique (+)-CC-1065 bonding site approximately one helix turn apart demonstrate that the directionality of drug-induced bending is in toward the minor groove and the locus of bending is about 2-3 base pairs to the 5'-side of the covalently modified adenine. A circularization efficiency assay shows that the optimum size of circles produced by (+)-CC-1065 and related drugs is between 168 and 180 base pairs. These results are discussed in relation to the molecular basis of the DNA sequence selectivity of (+)-CC-1065, and the (+)-CC-1065-induced DNA bending is compared with the intrinsic bending associated with adenine tracts. Since (+)-CC-1065 induces effects on local DNA structure that appear similar to those produced naturally by adenine tracts and certain DNA binding proteins, the relevance of this phenomenon to biological effects of (+)-CC-1065 and related drugs is considered.

[The effect of the emergent vaccination using DTP vaccine to control the outbreak of pertussis]

This paper reports the results of the effects of the emergent vaccination with DTP vaccine to control the outbreak of pertussis. Objects of observation were 4-6 years old children of kindergarten having pertussis vaccination and exposed history. The children were at random divided into two groups: 76 children were vaccinated with DTP vaccine and 72 children were inoculated with placebo. The results of observation: there was no strong and abnormal reaction in the vaccinated children; two weeks and three months after emergent vaccination with DTP vaccine, GMT antibody of pertussis were increased 18.14 and 4.73 times more than before vaccination respectively. There were no differences of the attack rates average days from vaccination to onset, average days of cough (P greater than 0.2) within 21 days after vaccination between the two groups. The protection rate was 62.11% three months after vaccination. The results showed that the emergent vaccination with DTP to control the outbreak of pertussis was safe and effective.

Establishment of a permanent rat brain-derived glial cell line as a source of purified oligodendrocyte-type 2 astrocyte lineage cell populations

A permanent glial cell line (L3) has been established from mixed glial cultures obtained from neonatal rat forebrain by repetitive passaging and selection of the process-bearing cells growing on top of a flat cell monolayer. Continuous propagation of the process-bearing cells was supported by the flat cells, of presumed astroglial origin, which were present in negligible amounts following each passage but then grew and formed a basal, feeder layer. Throughout a culture period of over 2 years, the L3 cells have maintained a stable morphological and antigenic phenotype. In serum-containing culture medium, most of the process-bearing cells expressed at the same time features of immature oligodendrocytes (O4 positivity) and of astrocytes [glial fibrillary acidic protein (GFAP) positivity]. A smaller proportion of them was labeled by the monoclonal antibody LB1. LB1+ or O4+ cells were rarely GFAP-, and GFAP+ cells were rarely LB1- or O4-. GalC+ oligodendrocytes were seen only occasionally, but the proportion of these cells increased up to 30% upon culturing in chemically defined medium containing 0.5% fetal calf serum. The L3 process-bearing cells accumulated the neurotransmitter gamma-aminobutyric acid (GABA), expressed the proteoglycan chondroitin sulfate, and responded to the mitogenic action of platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF). All these properties are characteristic of cells belonging to the O-2A (oligodendrocyte-type 2 astrocyte) cell lineage. The L3 flat cells were largely negative for the glial markers tested, but resembled type 1 astrocytes in their ability to support the growth of O-2A lineage cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Variation of secretory antibodies in parotid saliva to human immunodeficiency virus type 1 with HIV-1 disease stage

The secretory immune response to pathogens of the gut-associated lymphoid tissue is often independent of the systemic response. We investigated and compared the presence of antibodies to human immunodeficiency virus type 1 (HIV-1) antigens in parotid saliva and serum by Western blotting in 22 HIV-1-infected individuals. Antibodies to the HIV-1 envelope antigen gp160 were detected in saliva samples from 21 of 22 individuals and in serum from all individuals who were classified as CDC Group II, III, or IV. Antibody titers to gp160 were approximately 3000 times higher in serum than in saliva. Antibodies to viral core antigen p24 were detected in 6 of 7 Group II individuals in saliva and in 7 of 7 in serum. Antibodies to p24 were not found in the parotid saliva, but were detected in the sera of 3 of 3 Group III and 11 of 12 Group IV patients. The absence of secretory antibodies to HIV-1 core antigen p24 was correlated with CD4+ cell counts of less than 200/mm3. The results suggest that loss of secretory anti-p24 antibodies may be an early sign of progression to higher CDC clinical stages in HIV-1-infected individuals.

High expression of multinucleated giant cells in cultures of peripheral blood cells from HIV infected patients

Multinucleated giant cells (MGCs) were detected in cell lines established from peripheral blood lymphocytes of patients with: (a) acquired immunodeficiency syndrome (AIDS) and lymphadenopathy syndrome (LAS), (b) chronic active hepatitis (CAH), (c) papular acrodermatitis (PA) negative for hepatitis B virus antigens but positive for EBV, and (d) epidermolysis bullosa acquisita positive for EBV. All the cell lines established, including those established from AIDS and LAS patients, were examined for the presence of human immunodeficiency virus (HIV) by indirect immunofluorescence with monoclonal antibodies directed against the HIV antigens p17 and p24 and for the presence of reverse transcriptase. All the cell lines were found to be negative for HIV. While the cell lines obtained from AIDS patients still express MGCs after more than two years in culture, their supernatants are negative for reverse transcriptase activity and carry phenotypic markers characteristic of B cells. From the LAS and chronic active hepatitis patients we obtained a monolayer of adherent cells almost completely represented by MGCs that lasted for six and four months, respectively. After this period of time a proliferation process took place. Both the cell lines obtained carry B cell phenotypic markers, but MGCs are still a characteristic only for the LAS-derived cell culture. Non infected patients or normal subjects express MGCs only during the early stage of the cultue. The correlation between the presence of MGCs and a retrovirus infection is discussed in the light of the role of MGCs in the pathogenesis of AIDS.

The regulation of transcription of the gerA spore germination operon of Bacillus subtilis

The gerA operon of Bacillus subtilis 168 comprises three genes concerned with the triggering of spore germination by L-alanine and its analogues. The expression of this operon has been characterized using chromosomal lacZ fusions to the gerA promoter. The gerA promoter is switched on 2.5-3 hours after the initiation of sporulation, in parallel with glucose dehydrogenase. A high proportion of the gerA-driven beta-galactosidase detected in sporulating cells is found in the mature spore; the gerA promoter is therefore active in the forespore compartment of the sporulating cell. The gerA promoter is not expressed in spoO, spoII or spoIIIA, B, E and G mutant backgrounds, but is expressed in spoIIIC and D and in spoIV and V mutants. The in vivo transcriptional startpoint of the operon has been mapped by primer extension experiments; sequences upstream from this startpoint show significant homology with recognition sequences for RNA polymerase containing sigma G (E sigma G). The gerA operon was transcribed in vitro by E sigma G with a startpoint identical to that used in vivo, and expression of the gerA operon was rapidly induced in vegetative cells by induction of sigma G synthesis. These data indicate that the gerA operon is an additional member of the sigma G regulon, which includes a number of genes expressed in parallel only in the forespore compartment of sporulating B. subtilis cells.

Functional heterogeneity among CD4+ encephalitogenic T cells in recruitment of CD8+ T cells in experimental autoimmune encephalomyelitis

Inoculation of Lewis rats with live or attenuated (irradiated or paraformaldehyde-fixed) CD4+ encephalitogenic T cells (S1 line) protects the recipients from transferred experimental autoimmune encephalomyelitis (tEAE) induced by S1 cells. A CD8+ T lymphocyte population specifically activated against the EAE-inducing S1 cells can be readily isolated from the lymphoid organs of pretreated animals. We show, in the present study, that encephalitogenic T cell lines derived from Lewis rats differ in their ability to induce resistance against tEAE in vivo and to stimulate CD8+ cell proliferation in vitro. We also demonstrate that the S19 line of encephalitogenic T cells, in combination with myelin basic protein (MBP), can stimulate CD8+ cell proliferation in vitro. The CD8+ cells generated in this way strongly suppress MBP-specific T cell proliferation in vitro. This combined effect of T cells and MBP was also evident in vivo. Neither S19 cells nor MBP alone induced resistance against S19-mediated tEAE, rather coinjection of these cells and MBP was required. Our results suggest that resistance to EAE is mediated by distinct populations of encephalitogenic T cells that activate Ts cells through different mechanisms. In some instances, both autoreactive T cells and their relevant autoantigen(s) may be needed to activate Ts cells in vivo.

Inactivation of human immunodeficiency virus (HIV) by ionizing radiation in body fluids and serological evidence

A method to use ionizing radiation to inactivate HIV (Human Immunodeficiency Virus) in human body fluids was studied in an effort to reduce the risk of accidental infection to forensic science laboratory workers. Experiments conducted indicate that an X-ray absorbed dose of 25 krad was required to completely inactivate HIV. This does not alter forensically important constituents such as enzymes and proteins in body fluids. This method of inactivation of HIV cannot be used on body fluids which will be subjected to deoxyribonucleic acid (DNA) typing.

Functional heterogeneity among CD4+ encephalitogenic T cells in recruitment of CD8+ T cells in experimental autoimmune encephalomyelitis

Inoculation of Lewis rats with live or attenuated (irradiated or paraformaldehyde-fixed) CD4+ encephalitogenic T cells (S1 line) protects the recipients from transferred experimental autoimmune encephalomyelitis (tEAE) induced by S1 cells. A CD8+ T lymphocyte population specifically activated against the EAE-inducing S1 cells can be readily isolated from the lymphoid organs of pretreated animals. We show, in the present study, that encephalitogenic T cell lines derived from Lewis rats differ in their ability to induce resistance against tEAE in vivo and to stimulate CD8+ cell proliferation in vitro. We also demonstrate that the S19 line of encephalitogenic T cells, in combination with myelin basic protein (MBP), can stimulate CD8+ cell proliferation in vitro. The CD8+ cells generated in this way strongly suppress MBP-specific T cell proliferation in vitro. This combined effect of T cells and MBP was also evident in vivo. Neither S19 cells nor MBP alone induced resistance against S19-mediated tEAE, rather coinjection of these cells and MBP was required. Our results suggest that resistance to EAE is mediated by distinct populations of encephalitogenic T cells that activate Ts cells through different mechanisms. In some instances, both autoreactive T cells and their relevant autoantigen(s) may be needed to activate Ts cells in vivo.

Inhibition of human immunodeficiency virus in early infected and chronically infected cells by antisense oligodeoxynucleotides and their phosphorothioate analogues

Antisense oligodeoxynucleotides, both the phosphorothioate analogues and unmodified oligomers of the same sequence, inhibit replication and expression of human immunodeficiency virus already growing in tissue cultures of MOLT-3 cells with much greater efficacy than do mismatched ("random") oligomers and homooligomers of the same length and with the same internucleotide modification. This preferential inhibitory effect is elicited in as short a time as 4-24 hr postinfection. Likewise, antisense oligomers exhibit greater inhibitory effects on human immunodeficiency virus in chronically infected cells than do mismatched oligomers and homooligomers. Phosphorothioate antisene oligomers are up to 100 times more potent than unmodified oligomers of the same sequence in these inhibitory assays. These results, in major respects, confirm and extend those recently published by Matsukura et al. [Matsukura, M., Zon, G., Shinozuka, K., Robert-Guroff, M., Shimada, T., Stein, C. A., Mitsuza, H., Wong-Staal, F., Cohen, J. S. & Broder, S. (1989) Proc. Natl. Acad. Sci. USA 86, 4244-4248]. They also point out the importance of computer analysis of sequences though to be random but that in reality contain significant areas of likely hybridization, either to the viral genome or to the complementary DNA strand synthesized from it. They thus reinforce the concept that specific base pairing is a crucial feature of oligonucleotide inhibition of human immunodeficiency virus.

Inhibitors of adenosine catabolism improve recovery of dog myocardium after ischemia

The effects of inhibitors of adenosine catabolism on contractile function and metabolites were assessed during 15 minutes of ischemia followed by 30 minutes of reperfusion in the open-chest dog heart. As compared to sham treatment, pretreatment with erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and dipyridamole (DP) protected contractile function during ischemia, and improved recovery of high energy phosphate content and contractile function during reperfusion following ischemia. Testing EHNA and DP in a free-radical generating system indicated both compounds have some scavenging ability, suggesting the effect of EHNA + DP may not be on adenosine nucleotide metabolism alone. Comparison of end diastolic segment lengths to contractile function indicated the results were not affected by changes in preload resulting from peripheral vasodilation.

Inhibition of HIV replication by liposomal encapsulated amphotericin B

This report shows the potential of using a liposomal encapsulated preparation of amphotericin B (a polyene macrolide antibiotic) for the in vitro inhibition of HIV. There was no significant difference between the effective doses of the free form of drug when compared to the liposomal encapsulated preparation in inhibiting the growth of HIV. Virus expression was suppressed at a concentration of 5-10 micrograms/ml of the drugs. The liposomal preparation showed greatly reduced cytotoxicity in experiments using cultures of murine leukocytes. These results show the potential usefulness of liposomal encapsulated drugs in the treatment of patients with AIDS or AIDS related complex.

Evidence for an additional temporal class of gene expression in the forespore compartment of sporulating Bacillus subtilis

We present evidence indicating that the previously studied, sporulation-induced gene 0.3 kb, which encodes a stable RNA present at late developmental stages, is transcribed in the forespore chamber of sporulating cells of Bacillus subtilis. Compartmentalized gene expression was demonstrated on the basis of subcellular fractionation experiments in which severalfold-higher levels of 0.3 kb-directed beta-galactosidase specific activity were observed in forespore extracts than in extracts from the mother cell and dependence studies in which 0.3 kb transcription was found to be blocked in mutants bearing mutations in spoIIIA, spoIIIE, and spoIIIG, genes which are known to govern forespore gene expression. Also, 0.3 kb transcription could be switched on during growth in cells in which transcription of the forespore regulatory gene spoIIIG was engineered to be activated in response to the lac inducer IPTG (isopropyl-beta-D-thiogalactopyranoside). Although it is transcribed in the forespore, 0.3 kb is switched on at a later developmental stage than other previously studied forespore-expressed genes, and hence it appears to be representative of an additional temporal class of compartmentalized gene expression.

Conservation of the D-mannose-adhesion protein among type 1 fimbriated members of the family Enterobacteriaceae

A variety of genera and species of the family Enterobacteriaceae bear surface fimbriae that enable them to bind to D-mannose residues on eukaryotic cells. Until recently, it was thought that the D-mannose binding site was located in the major structural subunit (FimA), of relative molecular mass (Mr) 17,000 (17 K), of these organelles in Escherichia coli. New evidence indicates that this binding site resides instead in a minor protein Mr 28-31 K (FimH) located at the tips and at long intervals along the length of the fimbriae, and is reminiscent of the minor tip adhesion proteins of pyelonephritis-associated pili (Pap) and S fimbriae. In contrast to the antigenic heterogeneity of the major FimA subunit, the antigenic structure of FimH is conserved among different strains of E. coli. Here, we report an even broader conservation of this minor adhesion protein extending to other genera and species of type 1 fimbriated Enterobacteriaceae. Our results may have implications for the development of broadly protective vaccines against Gram-negative bacillary infections in animals and perhaps in man.

Regulatory circuits in autoimmunity: recruitment of counter-regulatory CD8+ T cells by encephalitogenic CD4+ T line cells

In this study, pretreatment of Lewis rats with a syngeneic encephalitogenic T cell line (S1) was found to be able to constantly induce resistance to the subsequent induction of transferred experimental autoimmune encephalomyelitis (tEAE). This treatment was capable of protecting recipient animals for at least 2-4 months. Here we show an enhanced suppressor T(anti-S1) cell activity, which can be readily detected in the lymphoid organs of animals which recovered from S1-induced tEAE, or from rats pretreated with attenuated (irradiated, fixative treated or water-lysed) S1 cells. Anti-S1 cells, which uniformly express the CD8 phenotype, were selectively stimulated to grow and expand into lines by confronting primed lymphoid cells with irradiated S1 cells in culture. The proliferative response of anti-S1 cells was independent of myelin basic protein and antigen-presenting cells, and the responses against unrelated encephalitogenic T cell lines were minimal. It was also found that none of the monoclonal antibodies tested (including CD8 and MHC class I antigen-specific antibodies) was able to block S1/anti-S1 interactions. These cells are functionally suppressive to the proliferation of S1 cells in vitro, are specifically cytolytic directed against the EAE-inducing S1 cells and are able to antagonize encephalitogenic capacity of S1 cells in vivo. In vivo elimination of the CD8+ T subset from Lewis rats, using a combined treatment of thymectomy and OX-8 antibody injection before the initial cell transfer, totally blocked the induction of resistance. Our experiments document that induction of functionally active suppressor T cells is responsible for the induced resistance observed in tEAE.

Berberine sulfate blocks adherence of Streptococcus pyogenes to epithelial cells, fibronectin, and hexadecane

Berberine sulfate is an alkaloid extracted from the roots and bark of various plants and possesses antibacterial, antifungal, and antiprotozoal activities. Most studies have focused on the bacteriostatic or bactericidal activities of this compound. In this study, we report that berberine sulfate is bacteriostatic for streptococci and that sub-MICs of berberine blocked the adherence of streptococci to host cells, immobilized fibronectin, and hexadecane. Concentrations of berberine below its MIC caused an eightfold increase in release of lipoteichoic acid from the streptococci. Higher concentrations of berberine directly interfered with the adherence of streptococci to host cells either by preventing the complexing of lipoteichoic acid with fibronectin or by dissolution of such complexes once they were formed. Thus, berberine sulfate interferes with the adherence of group A streptococci by two distinct mechanisms: one by releasing the adhesin lipoteichoic acid from the streptococcal cell surface and another by directly preventing or dissolving lipoteichoic acid-fibronectin complexes.

Inhibition of human immunodeficiency virus replication by antisense oligodeoxynucleotides

Twenty different target sites within human immunodeficiency virus (HIV) RNA were selected for studies of inhibition of HIV replication by antisense oligonucleotides. Target sites were selected based on their potential capacity to block recognition functions during viral replication. Antisense oligomers complementary to sites within or near the sequence repeated at the ends of retrovirus RNA (R region) and to certain splice sites were most effective. The effect of antisense oligomer length on inhibiting virus replication was also investigated, and preliminary toxicity studies in mice show that these compounds are toxic only at high levels. The results indicate potential usefulness for these oligomers in the treatment of patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex either alone or in combination with other drugs.

Influence of berberine sulfate on synthesis and expression of Pap fimbrial adhesin in uropathogenic Escherichia coli

We investigated the influence of berberine sulfate, an ancient Chinese antibiotic, upon the adhesion of uropathogenic Escherichia coli to erythrocytes and epithelial cells. Although berberine sulfate in increasing concentrations had no effect on bacterial growth or on the synthesis of major outer membrane proteins of the E. coli organisms, it increasingly blocked adhesion. The decreased adhesion was accompanied by a reduction in the synthesis of fimbrial subunits and in the expression of assembled fimbriae. These results suggest that the anti-infectious activity of berberine sulfate in E. coli-induced urinary tract infections may be mediated by the selective suppression of the synthesis and assembly of fimbriae by uropathogenic organisms.

A Mobile Oocyte Incubation Unit (MOIU): a device for improvement of the gamete intrafallopian transfer (GIFT) program

Forty couples with infertility due to various causes were selected for the gamete intrafallopian transfer (GIFT) program at our hospital. When the first 21 couples (Group A) had been treated in the program, the rate of pregnancy achieved was 23.8%, which did not seem satisfactory. This might have been caused by the distance between the embryo laboratory and the operating room. To eliminate this defect, a Mobile Oocyte Incubation Unit (MOIU) was designed. This is actually a compact laboratory that can be placed in the operating room. After the MOIU was utilized, the rate of pregnancy for the following 19 couples (Group B) increased to 42.1%. The MOIU has helped improve the performance of the GIFT program by increasing the stability of the pH value of the culture medium (Chetkowski R, et al.: J Vitro Fert Embryo Transfer 1985;2:207), lessening the exposure of the gametes to air and room temperature, and most importantly, shortening the time required for a GIFT procedure from 45-100 to 15-30 min. We expect that the MOIU will eventually become an integral part of the standard equipment for the GIFT program and make the program more successful and reliable in the treatment of infertility.

Dual biological activity of apurinic acid on human lymphocytes: induction of interferon-gamma and protection from human immunodeficiency virus infection in vitro

The chemically modified DNA, apurinic acid (APA), is cytotoxic for human lymphocytes at concentrations above 100 micrograms/ml. At low concentrations (0.05-1 micrograms/ml) APA acts as an inducer interferon gamma (IFN-gamma) in lymphocytes in vitro; the maximum interferon titer of 50 units/ml was reached at 0.4 micrograms/ml. When added to the cells in combination with phytohemagglutinin A (PHA), APA displays a significant synergistic interferon-inducing ability; the maximum titer of 940 units/ml was obtained with 10 micrograms/ml of APA and 6.25 micrograms/ml of PHA. APA also proved to be an effective inhibitor of human immunodeficiency virus (HIV-1) replication in H9 cells. At a concentration of 10 micrograms/ml, APA causes a 49% inhibition of virus growth, while 20 micrograms/ml of APA are required to inhibit expression of HIV-1 p17 and p24 gag proteins by 60%. The mechanism of anti HIV-1 activity of APA likely occurs at the level of viral reverse transcriptase. This enzyme is inhibited by APA in a noncompetitive way with a Ki of 0.39 microM, while the cellular DNA polymerases alpha, beta and gamma are 140- to 300-fold less sensitive to APA.

Scintillation counting of 14C-labeled soluble and insoluble compounds in plant tissue

A method is described for the liquid scintillation counting of 14C in plant tissues. Samples are fixed, in the scintillation vial, in a solution of ethanol and acetic acid (3:1) and decolorized with commercial bleach before the addition of scintillation liquid. The method was compared to other techniques of tissue oxidation or digestion and found to be equally effective at least with thin tissue samples. The technique is simple, rapid, and inexpensive and does not result in loss of 14C.