Early induction of interferon-independent virus-specific ICAM-1 (CD54) expression by flavivirus in quiescent but not proliferating fibroblasts--implications for virus-host interactions

West Nile Virus (WNV) infection of human embryonic fibroblasts can induce expression of ICAM-1 by two distinct mechanisms. An early and direct mechanism occurs within 2 hr of virus infection which is cytokine independent, and an indirect mechanism occurs within 24 hr of virus infection and is regulated by the release of IFN-type 1. Virus-inactivated, conditioned supernatants removed from WNV-infected fibroblast cultures at 4 hr did not alter ICAM-1 expression on fresh, untreated fibroblasts, whereas conditioned supernatants from 24-hr-infected cultures induced small increases in ICAM-1 expression after incubation for 24 hr but not after 4 hr. These studies also demonstrate that the expression of ICAM-1 on fibroblasts in response to flavivirus is cell-cycle dependent. WNV can only induce increased ICAM-1 expression in quiescent fibroblasts in G0 phase. In contrast, induction of ICAM-1 after exposure to types 1 and 2 IFN is not cell-cycle dependent. Other viruses, including double-stranded DNA viruses, vaccinia, and adenovirus 2 and 5 and the single, positive-stranded RNA alphavirus, Semiliki Forest virus, did not induce ICAM-1 expression on fibroblasts after 24 hr. Another alphavirus, Ross river, was able to induce ICAM-1 but only by the indirect mechanism of type 1 IFN-dependent release. The closely related flavivirus, Kunjin, induced increased ICAM-1 expression in a manner similar to WNV. The ability of flaviviruses to induce increased ICAM-1 expression directly within a few hours of infection may be an important virus-host survival strategy promoting cell-cell adhesion and hence possible further viral infection/replication.

Adherence status regulates the primary cellular activation responses to the flavivirus West Nile

Increases in cell-surface intercellular adhesion molecule-1 (ICAM-1; CD54) and major histocompatibility complex antigen class I (MHC-I) and class II (MHC-II) expression during flavivirus infection of murine macrophages was strongly dependent on adherence status. CD54 and MHC expression was significantly increased during infection with the flavivirus West Nile (WNV) on adherent, but not on non-adherent, macrophages. In contrast, increased CD54 and MHC-I expression was induced by interferon-gamma (IFN-gamma) in both cultures but was significantly greater on adherent cells than non-adherent cells. Adherent status was also important in human embryonic fibroblasts (HEF), adherent cells of non-immune origin. Similar to macrophages, WNV induced increased CD54 or MHC-I expression on adherent but not non-adherent HEF. Again, induction of these antigens by IFN-gamma occurred in both cultures but was significantly greater on adherent cells than non-adherent cells. Macrophages or HEF that aggregated when cultured at high density under non-adherent conditions, responded to WNV and IFN-gamma in a manner similar to adherent cells. Unresponsive non-adherent cells infected with WNV or treated with IFN-gamma under non-adherent conditions for 24 or 48 hr recovered if transferred to adherent culture conditions for 24 or 48 hr. Moreover, these cells expressed significantly higher cell-surface CD54 and MHC-I concentrations, compared to similarly treated HEF cultured under adherent conditions during the entire culture period. WNV infection also induced significant nitric oxide production in macrophages, and adherence status was similarly important in this response, with adherent cells producing higher amounts of nitrite/nitrate than non-adherent cells. These results suggest that adherent status may be critical for effective antiviral immune responses involving macrophages.

Diagnosis, assessment, and treatment of internalizing problems in children: the role of longitudinal data

This review examines the role of longitudinal data in the diagnosis, assessment, and treatment of internalizing disorders in children and adolescents. On the basis of the limited longitudinal data available, it is suggested that internalizing disorders in children and adolescents are highly prevalent, frequently comorbid with other childhood disorders, and, arguably so, persistent over time. However, it is also noted that a considerable amount of instability characterizes these disorders and that the developmental course is not fully understood at this time. In addition, these disorders are responsive to treatment, at least on a short-term basis. Finally, a plea is made for longitudinal studies that use a developmental perspective in examining internalizing disorders in children and adolescents.

Interferon gamma induces intercellular adhesion molecule-1 on murine midterm trophoblast and enhances susceptibility to specific lysis by paternally directed allo-immune cytotoxic T cells

Expression and function of intercellular adhesion molecule-1 (ICAM-1) on murine trophoblast cells and its regulation by interferon gamma (IFN-gamma) were investigated. Flow cytometry was used to detect ICAM-1 and class I major histocompatibility complex (MHC) antigen expression, while a 51Cr release assay was used to investigate the role of ICAM-1 in cytotoxic T lymphocyte (CTL)-mediated lysis and the effect of anti-ICAM-1 antibody blockade on lysis. We found that murine trophoblasts cells from midterm pregnancy (Day 14 postcoitum) express low or undetectable ICAM-1 and MHC antigens but that these are readily inducible by IFN-gamma. Untreated cells resisted lysis by allospecific CTL however, after treatment with IFN-gamma for 72 h, these trophoblasts were readily susceptible to lysis by allospecific CTL. The lysis was significantly reduced by anti-ICAM-1 antibody blocking. This finding which indicates that ICAM-1 can take part in CTL-mediated lysis of midterm trophoblast, has potentially important implications in vivo for the immunological relationship between mother and fetus.

Assessing the fears of children with disability using the Revised Fear Survey Schedule for Children: a comparative study

This study compared the self-reported fears of children with disability using the Fear Survey Schedule for Children-Revised (FSSC-R). Children with intellectual disability reported a significantly greater number of fears than children with no disability, children with hearing impairment and children with visual impairment. Also the children with intellectual disability reported more idiosyncratic fears related to the unknown, injury and small animals. Consistent with normative findings (King et al., 1989b; Ollendick, King & Frary, 1989), girls reported significantly more fears than boys. Methodological issues are discussed including the reliability and validity of self-reported fears for children with disability.

Diagnosis, assessment, and treatment of internalizing problems in children: the role of longitudinal data

This review examines the role of longitudinal data in the diagnosis, assessment, and treatment of internalizing disorders in children and adolescents. On the basis of the limited longitudinal data available, it is suggested that internalizing disorders in children and adolescents are highly prevalent, frequently comorbid with other childhood disorders, and, arguably so, persistent over time. However, it is also noted that a considerable amount of instability characterizes these disorders and that the developmental course is not fully understood at this time. In addition, these disorders are responsive to treatment, at least on a short-term basis. Finally, a plea is made for longitudinal studies that use a developmental perspective in examining internalizing disorders in children and adolescents.

Ontogeny of major histocompatibility complex antigen expression on cultured human embryonic skeletal myoblasts

Human embryonic myoblasts isolated from 13- to 19-week embryos were treated for 24 to 144 hr with 0.1-500 U/ml IFN-gamma and the constitutive and IFN-gamma-inducible MHC expression was examined by flow cytometry. Low levels of constitutive MHC I were expressed that increased with both developmental age and incubation time. In contrast, no constitutive MHC II was detected on human embryonic myoblasts at any age or incubation time. Both classes of MHC can be induced by IFN-gamma. Maximal MHC I induction increased in parallel with age, i.e., maximal induction occurred on 19-week myoblasts, while MHC II induction peaked at 17 weeks. IFN-gamma-induced expression of MHC I and II also increased with incubation time. Induced expression of MHC I antigen reached plateau levels at 72 hr of IFN-gamma incubation, whereas MHC II increased to a plateau level at 120 hr. The immunological importance of these findings for myoblast transfer therapy is discussed.

HIV infection of placental macrophages: their potential role in vertical transmission

Placental macrophages were isolated and cultured in vitro to investigate their susceptibility to HIV infection and possible role in vertical transmission of HIV. After 10 days of in vitro culture the cells were positive for nonspecific esterase and acid phosphatase and negative for myeloperoxidase and placental alkaline phosphatase. They expressed cell surface HLA-ABC, HLA-DR, CD45, as well as CD68 intracellularly, as detected by flow cytometry, confirming their macrophage lineage. Approximately 80% of cells expressed surface CD14. CD4 antigen was expressed at very low levels and was confirmed by antibody blocking experiments. Infection of placental macrophage cultures with HIV resulted in a transient peak of viral replication 3 to 7 days after infection, but no later rise in HIV was detected with culture of up to 60 days. HIV replication was not up-regulated by coculture with phytohemagglutinin-stimulated lymphocytes or by treating infected cultures with tumor necrosis factor alpha or granulocyte-macrophage colony-stimulating factor.

CTL recognition of west Nile virus-infected fibroblasts is cell cycle dependent and is associated with virus-induced increases in class I MHC antigen expression

Confluent and non-confluent mouse embryo fibroblast (CMEF and NCMEF) monolayers were infected with West Nile virus (WNV) for 24 hr, and class I major histocompatibility complex antigen (MHC-I) concentrations measured by flow cytometry (FCM). Concentrations on CMEF increased significantly more than on NCMEF. This was not owing to differences in interferon-beta (IFN-beta)-mediated MHC induction, as the IFN-beta quantity secreted by each infected fibroblast was similar in each culture, and IFN-beta-mediated MHC-I induction on NCMEF was greater than on CMEF. Furthermore, despite neutralization of WNV-induced supernatant IFN-beta, CMEF increased MHC-I expression significantly more than NCMEF. Functionally, WNV-infected CMEF were lysed 10-fold better by WNV-specific and allospecific cytotoxic T cells, than infected NCMEF. FCM demonstrated 76% CMEF and 68% NCMEF distributed in G0/G1. This represented G0 in CMEF, and G1 in NCMEF, confirmed by ribonucleotide reductase M1 subunit labelling, where only 20% CMEF was labelled, compared to 84% NCMEF. The possible implications for antiviral immune responses are discussed.

Fears and their level of interference in adolescents

In this study, we first explored the prevalence of self-reported fears in 648 Australian adolescents and then determined the extent of interference associated with those fears. Consistent with other studies, fears were highly prevalent. An average of 9 fears was reported. Girls reported more fears than boys and younger adolescents reported more fears than older adolescents. A majority of the youth reported that their fears caused them considerable distress and that their fears interfered significantly with their daily activities. The limitations of the study were acknowledged and directions for future research were suggested.

1H magnetic resonance spectroscopy of primary human and murine cells of the myeloid lineage

Murine and human cells of the myeloid lineage can exhibit proton spectra arising primarily from neutral lipid such as triglyceride, similar to other activated and transformed cell types. These spectral characteristics are independent of proliferation or proliferative ability and can be induced in vivo and in vitro in murine peritoneal macrophages by Listeria and interferon-gamma stimulation, respectively. In human peripheral monocytes, this spectrum can develop in the apparent absence of external activating stimuli such as interferon or endotoxin and also occurs in the absence of proliferation. Furthermore, 16-h culture of mixed peripheral blood cells causes concomitant and similar spectral changes in lymphocytes, which do not occur in pure lymphocyte cultures. The lipid spectra induced in mixed cultures develop to the same extent regardless of cell density or the ability to adhere or form aggregates and regardless of whether serum supplementation is of fetal bovine or adult human origin. Unlike peritoneal macrophages, the addition of interferon-gamma causes no additional spectral changes in adherent or nonadherent cultures. However, reduction of serum concentrations in culture medium causes a dose-dependent decrease in the acquired lipid signal. The observed spectral differences between human and murine myeloid populations could be species-dependent but could also be due to their differentiation status.

Two-dimensional 1H NMR studies of membrane changes during the activation of primary T lymphocytes

Two-dimensional 1H NMR spectroscopy was used to quantify the level of "mobile" plasma membrane triglyceride and the intracellular concentrations of water-soluble phospholipid precursors during the activation of both mature and immature primary T lymphocytes. The concentration of mobile triglyceride in the plasma membrane was seen to increase approximately 35-fold during 72 h of activation of murine thymic and splenic T lymphocytes with ionomycin and phorbol 12-myristate 13-acetate. This dramatic increase in mobile plasma membrane triglyceride during the activation of both mature and immature T-lymphocyte populations supports the hypothesis that immune cell activation is associated with increased plasma membrane fluidity. The intracellular concentrations of various phospholipid precursors were shown to increase during the early stages of T-lymphocyte activation and then remain at levels above those in resting cells. This may facilitate de novo phospholipid biosynthesis, which is presumably necessary since cell volume, and hence the plasma membrane surface area, was demonstrated to increase significantly during T-lymphocyte activation. Various models that might explain the origin of the NMR-visible plasma membrane triglyceride that is observed during immune cell activation and malignant transformation are examined.

Acute inflammatory activity of the S100 protein CP-10. Activation of neutrophils in vivo and in vitro

The murine S100 chemotactic protein of m.w. 10,000 termed (CP-10), has potent chemotactic activity for murine and human myeloid cells. We examined the ability of a synthetic CP-10 hinge region peptide CP-10(42-55) and rCP-10 to act as chemotactic agents and induce expression of the adhesion molecule Mac-1 (CD 11b/CD 18) in vivo. Maximal neutrophil (PMN) accumulation occurred between 2 to 8 h after mouse footpad injection of rCP-10 (10(-7) M) or CP-10 peptide (10(-6) M). The infiltrating PMN expressed high levels of Mac-1, and low levels of the murine L-selectin Mel-14. Injection of CP-10 peptide i.p. also induced infiltration of PMNs that expressed high levels of Mac-1. Cell suspensions obtained after i.p. injection of CP-10 peptide could be significantly inhibited from adhering to fibrinogen-coated plates when incubated with anti-Mac-1 antibody. The chemotactic activity of CP-10 peptide toward murine inflammatory PMN in vitro was also inhibited by anti-Mac-1 antibody. Neither CP-10 analogue stimulated or primed murine inflammatory or human blood neutrophils for superoxide production or granular enzyme release. The localization of CP-10 in vivo was examined using murine footpads injected with LPS and was found to be concentrated around the endothelial cells of the small blood vessels. This distribution suggests that the accumulated CP-10 the may contribute to the generation of a chemotactic gradient.

Acute inflammatory activity of the S100 protein CP-10. Activation of neutrophils in vivo and in vitro

The murine S100 chemotactic protein of m.w. 10,000 termed (CP-10), has potent chemotactic activity for murine and human myeloid cells. We examined the ability of a synthetic CP-10 hinge region peptide CP-10(42-55) and rCP-10 to act as chemotactic agents and induce expression of the adhesion molecule Mac-1 (CD 11b/CD 18) in vivo. Maximal neutrophil (PMN) accumulation occurred between 2 to 8 h after mouse footpad injection of rCP-10 (10(-7) M) or CP-10 peptide (10(-6) M). The infiltrating PMN expressed high levels of Mac-1, and low levels of the murine L-selectin Mel-14. Injection of CP-10 peptide i.p. also induced infiltration of PMNs that expressed high levels of Mac-1. Cell suspensions obtained after i.p. injection of CP-10 peptide could be significantly inhibited from adhering to fibrinogen-coated plates when incubated with anti-Mac-1 antibody. The chemotactic activity of CP-10 peptide toward murine inflammatory PMN in vitro was also inhibited by anti-Mac-1 antibody. Neither CP-10 analogue stimulated or primed murine inflammatory or human blood neutrophils for superoxide production or granular enzyme release. The localization of CP-10 in vivo was examined using murine footpads injected with LPS and was found to be concentrated around the endothelial cells of the small blood vessels. This distribution suggests that the accumulated CP-10 the may contribute to the generation of a chemotactic gradient.

Na(+)-dependent high affinity uptake of L-glutamate in primary cultures of human fibroblasts isolated from three different types of tissue

Cultured human fibroblasts isolated from embryonic muscle, skin and peripheral nerve tissues were found to accumulate [3H]L-glutamate by a Na(+)-dependent uptake process strongly inhibited by several glutamate/aspartate analogues including D- and L-aspartate, D- and L-threo-3-hydroxyaspartate and L-trans-pyrrolidine-2,4-dicarboxylate but not D-glutamate. It was also reduced by elevated concentrations of K+, Rb+ and Cs+. The values of Km's were 5-20 microM, well within the 'high affinity' region. Variations in the capacity (Vmax) of [3H]L-glutamate uptake did not correlate with the origin (muscle, skin or nerve tissue) of the fibroblasts. The uptake characteristics suggest that it is mediated by a transport system similar to that commonly observed only in brain tissue.

Panic in children and adolescents: a review

Based on our review of the available data, we conclude that panic attacks are common among adolescents, while both panic attacks and Panic Disorder appear to be present, but less frequent, in children. Furthermore, it is evident that both adolescents and children who report panic attacks describe the occurrence of cognitive symptoms, although with less frequency than physiological ones. Consistent with the cognitive model of panic, it seems that at least some youngsters are capable of experiencing the physiological symptoms of panic accompanied by the requisite catastrophic cognitions. However, a more complete understanding of the cognitive manifestation of panic attacks/disorder among children awaits further investigation. Future research should aim to explore the developmental progression in children's cognitive responses to specific panic symptomatology. Risk factors (e.g. anxiety sensitivity, depression) which may contribute to the likelihood of misinterpreting physiological sensations in a catastrophic manner throughout the course of development should also be assessed: Finally, we are in general agreement with Abelson and Alessi (1992) who argue that we must begin to ask ourselves how panic disorder may be manifested in children. That is, rather than assessing the frequency with which children experience symptoms of adult panic, we should explore what panic would look like in children. They propose that the study of panic in children would be facilitated by a reformulation of separation anxiety as a childhood expression of panic disorder. Although this reformulation makes intuitive sense and is appealing from a developmental perspective, we would insert a strong caveat. Although the research is yet to be conducted, it is probable that childhood separation anxiety is only one of many routes to panic disorder outcome. It is improbable that such direct and continuous pathways are present for the majority of children, adolescents and adults who experience panic disorder. More probably, the pathways are multiple, complex, and discontinuous (Robbins & Rutter, 1990). Much work remains to be done before we are able to ferret out the linkages between developmental processes and clinical outcomes for panic disorder in children and adolescents.

Human immunodeficiency virus type 1 infection of human placental macrophages in vitro

Placental macrophages (Hofbauer cells) were isolated and cultured in vitro to investigate their susceptibility to human immunodeficiency virus type 1 (HIV-1) infection. Of adherent cells, 80% expressed CD14, and > 99% were nonspecific esterase-positive. CD4 antigen was expressed at very low levels. CD4 mRNA could be detected in the cells by reverse transcription followed by polymerase chain reaction. The macrophages were infected productively after inoculation with low-passage blood isolates of cell-free HIV-1. Peak virus titers were detected 3-7 days after infection by HIV-1 antigen ELISA and reverse transcriptase assay. Replication of HIV-1 in placental macrophages was less than in blood monocytes. HIV-1 RNA was detected in placental macrophages by in situ hybridization 16 days after infection. Multinucleated giant cells were identified in some cultures, indicative of an HIV-induced cytopathic effect. Thus, placental macrophages can be infected productively with clinical isolates of HIV-1, and such cells may act as a reservoir of virus for transmission to the fetus in utero.

The fears of youth in the 1990s: contemporary normative data

This article reports the findings of a normative fear investigation involving a sample of 918 Australian children and adolescents, ranging in age from 7-18 years. The Fear Survey Schedule for Children and Adolescents-II (FSSC-II) was administered to determine self-reported prevalence, intensity, and content of fear. Consistent with past research, girls generally reported significantly higher levels of fearfulness than boys. Age differences also were found; younger children reported a higher intensity and a greater number of fears than older children and adolescents. Qualitative differences in normative fear were found, with younger children reporting more animal fears and older children reporting more fears relating to social evaluation or psychic stress. Significantly, although the specific content of children's and adolescents' normative fears in the 1990s (as compared with the 1960s) has changed (now including fear of AIDS and of nuclear war), the fears found to be most prevalent continue to relate to death and danger. These findings are discussed within the context of the prepotency and preparedness concepts of fear.

West Nile virus infection induces susceptibility of in vitro outgrown murine blastocysts to specific lysis by paternally directed allo-immune and virus-immune cytotoxic T cells

Day 3 post-coitum BALB/c and (BALB/c x CBA/H)F1 blastocysts were isolated and hatched in replicate wells. Some were treated with interferon-gamma (IFN-gamma). Whilst others were infected with West Nile Virus (WNV) at 100 plaque-forming units per cell, for 18 h. Controls were mock-treated. Gamma-irradiated (2000 rads) CBA/H, (paternal) WNV-specific and allo(CBA/H)-specific cytotoxic T (Tc) cells were then added to replicates of infected, mock-infected or IFN-gamma-treated cultures for 20 h. [3H]Thymidine was then added for a further 8 h. [3H]Thymidine incorporation was inhibited by 40-50% in WNV-infected cultures exposed to WNV-paternal-specific Tc cells and by 30-40% in WNV-infected cultures exposed to allo-paternal-specific Tc cells compared to similarly exposed, uninfected, or unexposed, WNV-infected, or unexposed, uninfected cultures. No significant differences in [3H]thymidine incorporation were found between these controls and IFN-gamma-treated cultures exposed to allo-paternal-specific Tc cells or IFN-gamma-treated cultures not exposed to Tc cells. Parallel exposure of L929 fibroblasts to the same Tc cells irradiated with 500-8000 rads in doubling doses, showed that irradiation did not alter the efficacy or specificity of the Tc cells. Relevance to maternal anti-viral immune responses during implantation is discussed.

Self-reports of panic attacks and manifest anxiety in adolescents

A recent paper by Nelles and Barlow (1988; Clinical Psychology Review, 8, 359-372) provided the rationale for an investigation of panic attacks in adolescents. A panic attack questionnaire and the Revised Children's Manifest Anxiety Scale were administered to an unselected sample of Australian adolescents. Of 534 adolescents, 42.9% reported having at least one panic attack. Other data are reported on the characteristics of panic attacks, life interference and avoidance behaviour. Panickers reported significantly higher anxiety levels than nonpanickers. Differences between the findings of Australian and American samples were noted and directions for future research were identified. Several methodological issues were also discussed including the reliability and validity of self-report data on panic attacks.

Treatment of childhood anxiety disorders using behaviour therapy and pharmacotherapy

Although the treatment of childhood anxiety disorders can be approached from numerous theoretical perspectives, the concentration of research has been on the efficacy of behaviour therapy. Behaviour therapy procedures are briefly described and evaluated, including systematic desensitisation, flooding, modelling, reinforcement and cognitive procedures. We also review research findings on pharmacotherapy, focusing on benzodiazepine and antidepressant usage. Finally, several conclusions are drawn concerning the scientific and clinical status of these treatment approaches for childhood anxiety disorders.

Flavivirus induces MHC antigen on human myoblasts: a model of autoimmune myositis?

Infection of human embryonic myoblasts by West Nile virus (WNV), a flavivirus, caused significant upregulation of class I and II MHC expression as determined by flow cytometry. After 48 hours at a multiplicity of infection of 5 pfu/cell, a sixfold increase in MHC class I expression was induced from initially low levels of expression. In contrast, MHC class II was induced de novo to five times the control fluorescence level. At least 70% of the cells were infected as determined using fluorescence microscopy and anti-WNV antibody labeling. Myoblasts were > 90% pure as shown by anti--Leu-19 labeling. MHC class I (but not class II) was increased threefold after exposure to virus-inactivated supernatant from 48-hour--infected cells, indicating the presence of factor(s) contributing to the MHC class I increase. These findings may be important in establishing a link between viral infection of human cells and induction of inflammatory autoimmune disease. We discuss the possibility of using WNV as an in vivo model.