Mental health symptoms in children and adolescents during COVID-19 in Australia

OBJECTIVE

COVID-19 has led to disruptions to the lives of Australian families through social distancing, school closures, a temporary move to home-based online learning, and effective lockdown. Understanding the effects on child and adolescent mental health is important to inform policies to support communities as they continue to face the pandemic and future crises. This paper sought to report on mental health symptoms in Australian children and adolescents during the initial stages of the pandemic (May to November 2020) and to examine their association with child/family characteristics and exposure to the broad COVID-19 environment.

METHODS

An online baseline survey was completed by 1327 parents and carers of Australian children aged 4 to 17 years. Parents/carers reported on their child's mental health using five measures, including emotional symptoms, conduct problems, hyperactivity/inattention, anxiety symptoms and depressive symptoms. Child/family characteristics and COVID-related variables were measured.

RESULTS

Overall, 30.5%, 26.3% and 9.5% of our sample scored in the high to very high range for emotional symptoms, conduct problems and hyperactivity/inattention, respectively. Similarly, 20.2% and 20.4% of our sample scored in the clinical range for anxiety symptoms and depressive symptoms, respectively. A child's pre-existing mental health diagnosis, neurodevelopmental condition and chronic illness significantly predicted parent-reported child and adolescent mental health symptoms. Parental mental health symptoms, having a close contact with COVID-19 and applying for government financial assistance during COVID-19, were significantly associated with child and adolescent mental health symptoms.

CONCLUSION

Our findings show that Australian children and adolescents experienced considerable levels of mental health symptoms during the initial phase of COVID-19. This highlights the need for targeted and effective support for affected youth, particularly for those with pre-existing vulnerabilities.

Co-designing a digital mental health platform, "Momentum", with young people aged 7-17: A qualitative study

Introduction

Digital mental health interventions (DMHIs) offer a promising alternative or adjunct treatment method to face-to-face treatment, overcoming barriers associated with stigma, access, and cost. This project is embedded in user experience and co-design to enhance the potential acceptability, usability and integration of digital platforms into youth mental health services.

Objective

To co-design a digital mental health platform that provides self-directed, tailored, and modularised treatment for young people aged 7-17 years experiencing anxiety, depression and other related problems.

Methods

Sixty-eight participants, aged 7-17 years, engaged in one of 20 co-design workshops. Eight workshops involved children (n  =  26, m  =  9.42 years, sd  =  1.27) and 12 involved adolescents (n  =  42, m  =  14.57 years, sd  =  1.89). Participants engaged in a variety of co-design activities (e.g., designing a website home page and rating self-report assessment features). Workshop transcripts and artefacts (e.g., participants' drawings) were thematically analysed using Gale et al.'s Framework Method in NVivo.

Results

Six themes were identified: Interactive; Relatable; Customisable; Intuitive; Inclusive; and Personalised, transparent and trustworthy content. The analysis revealed differences between children's and adolescents' designs and ideas, supporting the need for two different versions of the platform, with age-appropriate activities, features, terminology, and content.

Conclusions

This research showcased co-design as a powerful tool to facilitate collaboration with young people in designing DMHIs. Two sets of recommendations were produced: 1) recommendations for the design, functionality, and content of youth DMHIs, supported by child- and adolescent-designed strategies; and 2) recommendations for clinicians and researchers planning to conduct co-design and intervention development research with children and adolescents.

Correlates of distress in young people with cystic fibrosis: the role of self-efficacy and metacognitive beliefs

OBJECTIVES

While significantly elevated distress is repeatedly found amongst young people with cystic fibrosis, their determinants remain largely unknown. This study explored whether metacognitive beliefs and self-efficacy for emotion regulation were associated with anxiety and depression after control for physical functioning, age and gender.

DESIGN

Cross-sectional study using a 110-item online questionnaire.

METHODS

An online survey was undertaken by 147 young people with CF aged 10-18 from five countries. Associations of Hospital Anxiety and Depression Scale scores with gender, age, physical functioning, Metacognitive Beliefs Questionnaire for Children (MCQ-C) subscales and Self-Efficacy for Emotion Regulation (SE-ER) were examined using hierarchical multiple linear regressions.

RESULTS

Physical functioning, gender and age accounted for 31% of the variance in anxiety and 39% in depression. The MCQ-C and SE-ER added another 45% to the variance of anxiety and 32% to depression. At the final step of both analyses, physical functioning, SE-ER, MCQ-C Negative Meta-Worry and Superstition, Punishment & Responsibility contributed significantly. Older age was also significantly associated with depression.

CONCLUSIONS

Self-efficacy for emotion regulation, concern about worrying and shame may be particularly important foci for interventions aimed at ameliorating anxiety and depression in young people with CF.

A Metacognitive Intervention of Narrative Imagery for young people with cystic fibrosis: A feasibility study

Cystic fibrosis and its treatment can have substantial functional and emotional impacts on patients and their families. This feasibility study assessed a new cystic fibrosis treatment, Metacognitive Intervention of Narrative Imagery, integrating narrative and meta-cognitive therapies with mental imagery. A total of 13 patients, aged 10-17 years, received three 1-hour sessions and were assessed on emotional functioning, anxiety, and depression at baseline and 4 and 8 weeks post-baseline. Participants had significant improvements in anxiety, and changes in emotional functioning and anxiety had a medium effect size. Participants and parents rated Metacognitive Intervention of Narrative Imagery highly on usability and favourability. Further clinical trials are indicated.

MoodHacker Mobile Web App With Email for Adults to Self-Manage Mild-to-Moderate Depression: Randomized Controlled Trial

BACKGROUND

Worldwide, depression is rated as the fourth leading cause of disease burden and is projected to be the second leading cause of disability by 2020. Annual depression-related costs in the United States are estimated at US $210.5 billion, with employers bearing over 50% of these costs in productivity loss, absenteeism, and disability. Because most adults with depression never receive treatment, there is a need to develop effective interventions that can be more widely disseminated through new channels, such as employee assistance programs (EAPs), and directly to individuals who will not seek face-to-face care.

OBJECTIVE

This study evaluated a self-guided intervention, using the MoodHacker mobile Web app to activate the use of cognitive behavioral therapy (CBT) skills in working adults with mild-to-moderate depression. It was hypothesized that MoodHacker users would experience reduced depression symptoms and negative cognitions, and increased behavioral activation, knowledge of depression, and functioning in the workplace.

METHODS

A parallel two-group randomized controlled trial was conducted with 300 employed adults exhibiting mild-to-moderate depression. Participants were recruited from August 2012 through April 2013 in partnership with an EAP and with outreach through a variety of additional non-EAP organizations. Participants were blocked on race/ethnicity and then randomly assigned within each block to receive, without clinical support, either the MoodHacker intervention (n=150) or alternative care consisting of links to vetted websites on depression (n=150). Participants in both groups completed online self-assessment surveys at baseline, 6 weeks after baseline, and 10 weeks after baseline. Surveys assessed (1) depression symptoms, (2) behavioral activation, (3) negative thoughts, (4) worksite outcomes, (5) depression knowledge, and (6) user satisfaction and usability. After randomization, all interactions with subjects were automated with the exception of safety-related follow-up calls to subjects reporting current suicidal ideation and/or severe depression symptoms.

RESULTS

At 6-week follow-up, significant effects were found on depression, behavioral activation, negative thoughts, knowledge, work productivity, work absence, and workplace distress. MoodHacker yielded significant effects on depression symptoms, work productivity, work absence, and workplace distress for those who reported access to an EAP, but no significant effects on these outcome measures for those without EAP access. Participants in the treatment arm used the MoodHacker app an average of 16.0 times (SD 13.3), totaling an average of 1.3 hours (SD 1.3) of use between pretest and 6-week follow-up. Significant effects on work absence in those with EAP access persisted at 10-week follow-up.

CONCLUSIONS

This randomized effectiveness trial found that the MoodHacker app produced significant effects on depression symptoms (partial eta(2) = .021) among employed adults at 6-week follow-up when compared to subjects with access to relevant depression Internet sites. The app had stronger effects for individuals with access to an EAP (partial eta(2) = .093). For all users, the MoodHacker program also yielded greater improvement on work absence, as well as the mediating factors of behavioral activation, negative thoughts, and knowledge of depression self-care. Significant effects were maintained at 10-week follow-up for work absence. General attenuation of effects at 10-week follow-up underscores the importance of extending program contacts to maintain user engagement. This study suggests that light-touch, CBT-based mobile interventions like MoodHacker may be appropriate for implementation within EAPs and similar environments. In addition, it seems likely that supporting MoodHacker users with guidance from counselors may improve effectiveness for those who seek in-person support.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02335554; https://clinicaltrials.gov/ct2/show/NCT02335554 (Archived by WebCite at http://www.webcitation.org/6dGXKWjWE).

Optimal Response to Cardiac Arrest study: defibrillation waveform effects

INTRODUCTION

Advances in early defibrillation access, key to the "Chain of Survival", will depend on innovations in defibrillation waveforms, because of their impact on device size and weight. This study compared standard monophasic waveform automatic external defibrillators (AEDs) to an innovative biphasic waveform AED.

MATERIAL AND METHODS

Impedance-compensated biphasic truncated exponential (ICBTE) and either monophasic truncated exponential (MTE) or monophasic damped sine (MDS) AEDs were prospectively, randomly assigned by date in four emergency medical services. The study design compared ICBTE with MTE and MDS combined. This subset analysis distinguishes between the two classes of monophasic waveform, MTE and MDS, and compares their performance to each other and to the biphasic waveform, contingent on significant overall effects (ICBTE vs. MTE vs. MDS). Primary endpoint: Defibrillation efficacy with < or =3 shocks. Secondary endpoints: shock efficacy with < or =1 shock, < or =2 shocks, and survival to hospital admission and discharge. Observations included return of spontaneous circulation (ROSC), refibrillation, and time to first shock and to first successful shock.

RESULTS

Of 338 out-of-hospital cardiac arrests, 115 had a cardiac aetiology, presented with ventricular fibrillation, and were shocked by an AED. Defibrillation efficacy for the first "stack" of up to 3 shocks, for up to 2 shocks and for the first shock alone was superior for the ICBTE waveform than for either the MTE or the MDS waveform, while there was no difference between the efficacy of MTE and MDS. Time from the beginning of analysis by the AED to the first shock and to the first successful shock was also superior for the ICBTE devices compared to either the MTE or the MDS devices, while again there was no difference between the MTE and MDS devices. More ICBTE patients achieved ROSC pre-hospital than did MTE patients. While the rates of ROSC were identical for MTE and MDS patients, the difference between ICBTE and MDS was not significant. Rates of refibrillation and survival to hospital admission and discharge did not differ among the three populations.

CONCLUSIONS

ICBTE was superior to MTE and MDS in defibrillation efficacy and speed and to MTE in ROSC. MTE and MDS did not differ in efficacy. There were no differences among the waveforms in refibrillation or survival.

Multicenter, randomized, controlled trial of 150-J biphasic shocks compared with 200- to 360-J monophasic shocks in the resuscitation of out-of-hospital cardiac arrest victims. Optimized Response to Cardiac Arrest (ORCA) Investigators

BACKGROUND

In the present study, we compared an automatic external defibrillator (AED) that delivers 150-J biphasic shocks with traditional high-energy (200- to 360-J) monophasic AEDs.

METHODS AND RESULTS

AEDs were prospectively randomized according to defibrillation waveform on a daily basis in 4 emergency medical services systems. Defibrillation efficacy, survival to hospital admission and discharge, return of spontaneous circulation, and neurological status at discharge (cerebral performance category) were compared. Of 338 patients with out-of-hospital cardiac arrest, 115 had a cardiac etiology, presented with ventricular fibrillation, and were shocked with an AED. The time from the emergency call to the first shock was 8.9+/-3.0 (mean+/-SD) minutes.

CONCLUSIONS

The 150-J biphasic waveform defibrillated at higher rates, resulting in more patients who achieved a return of spontaneous circulation. Although survival rates to hospital admission and discharge did not differ, discharged patients who had been resuscitated with biphasic shocks were more likely to have good cerebral performance.

The solution structure of a class II major histocompatibility complex superantigen binding domain

We have used 600 MHz 1H NMR spectroscopy data to determine the solution structure of a 31-residue domain of a murine class II major histocompatibility (MHC) protein. This domain, I-Ab(beta)-(60-90), binds to the superantigen staphylococcal enterotoxin A. Distance geometry and dynamical simulated annealing calculations were performed using NOESY- and COSY-deduced constraints. I-Ab(beta)-(60-90), which is mostly alpha-helical, is more similar to the corresponding region of the class II MHC protein HLA-DR1 than to the class I MHC protein HLA-A2. Arg-72 and Arg-80 lie on the same side of the helix and face away from the antigenic peptide binding groove. His-81, implicated in both superantigen and peptide binding, is located midway between the surface defined by Arg-72/Arg-80 and residues that define the inside of the peptide binding groove, allowing for its participation in both types of binding.

Bodywork--the art of touch

Massage, neuromuscular therapy, Trager, and Bowen work reduce stress, relieve pain, rebalance the body, and restore a sense of general well-being. They can be used by themselves to promote physical and emotional health or with conventional medical care to restore health. This article examines the differences and similarities among these four therapies and concludes with case histories to illustrate the use of bodywork in primary care.

Identification of binding domains on the superantigen, toxic shock syndrome-1, for class II MHC molecules

Toxic shock syndrome toxin-1 (TSST-1) is a member of the staphylococcal enterotoxin superantigen family. In order to determine the regions on the TSST-1 molecule involved in binding to class II MHC, seven overlapping peptides of the entire TSST-1 molecule were synthesized and tested for their ability to compete with 125I-TSST-1 for binding to class II MHC on murine A20 cells and HLA on Raji cells. Peptides corresponding to N-terminal amino acid residues 39 through 68 and C-terminal residues 155 through 194 competed with 125I-TSST-1 for binding to class II MHC. Also, binding studies with class II MHC beta-chain peptides indicate that regions encompassed by I-A beta b(30-60) and I-A beta b(60-90) are binding regions for TSST-1. Thus, we have identified binding domains on the TSST-1 molecule for class II MHC molecule receptors on antigen presenting cells.

Evidence for the alpha-helicity of class II MHC molecular binding sites for the superantigen, staphylococcal enterotoxin A

Circular dichroism (CD) spectra of class II MHC peptides revealed the alpha-helical conformation of superantigen-binding peptides I-A beta b(60-90), I-A beta b(65-85), and I-A alpha b(51-80), but not the nonbinding peptide I-A beta b(80-100). These CD spectra provide biophysical evidence for the alpha-helicity of class II MHC molecular binding sites for the superantigen, staphylococcal enterotoxin A (SEA). Alanine-substituted analogs of the SEA binding-site peptide, I-A beta b(65-85), were used to implicate beta-chain residues 72 and 80 in class II MHC-SEA binding. The data support SEA binding away from the class II antigen binding cleft along the faces of the alpha-helices.

Staphylococcal enterotoxin superantigens

Staphylococcal enterotoxins (SE) are a family of structurally related proteins that are produced by Staphylococcus aureus. They play a role in the pathogenesis of food poisoning and are the most potent activators of T lymphocytes known. The receptors for SE on antigen-presenting cells are major histocompatibility complex class II molecules. Recent studies have shown that a complex of SE and major histocompatibility complex class II molecules is required for binding to the variable region of the T cell antigen receptor beta-chain. SE mitogenic activity is dependent on induction of interleukin 2, which may be intimately involved in the mechanism of SE toxicity. The minor lymphocyte-stimulating "endogenous" self-superantigen has recently been shown to be a retroviral gene product, so that this too is apparently a microbial superantigen. An understanding of the mechanism of action of these microbial superantigens has implications for normal and pathological immune functions.

Staphylococcal enterotoxin microbial superantigens

Staphylococcal enterotoxins are a family of structurally related proteins that are produced by Staphylococcus aureus. In addition to their role in the pathogenicity of food poisoning, these microbial superantigens have profound effects on the immune system, which makes them useful tools for understanding its mechanism of action. These molecules (24-30 kDa) are highly hydrophilic and exhibit low alpha helix and high beta pleated sheet content, suggesting a flexible, accessible structure. Staphylococcal enterotoxins are among the most potent activators of T lymphocytes known. The receptors for staphylococcal enterotoxins on antigen-presenting cells are major histocompatibility complex (MHC) class II molecules. Further, the alpha-helical regions of the class II molecule are essential for function and appear to interact directly with the NH2-terminal region of staphylococcal enterotoxins such as SEA. Recent studies have shown that a complex of staphylococcal enterotoxin and MHC class II molecules is required for binding to the V beta region of the T cell antigen receptor. Staphylococcal enterotoxin mitogenic activity is dependent on induction of interleukin 2, which may be intimately involved in the mechanism of toxicity. The mouse minor lymphocyte stimulating (M1s) "endogenous" self-superantigen has been shown to be a retroviral gene product, so this too is apparently a microbial superantigen. An understanding of the mechanisms of action of these microbial superantigens has implications for normal and pathological immune functions.

Both alpha-helices along the major histocompatibility complex binding cleft are required for staphylococcal enterotoxin A function

The superantigen staphylococcal enterotoxin A (SEA) requires interaction with class II major histocompatibility complex (MHC) molecules to activate T cells. We have previously used the synthetic peptide approach to establish one side of the hypothetical class II foreign-antigen binding cleft, alpha-helical region 65-85 of the beta chain, as a binding site involved in accessory cell presentation of SEA to T cells. To further characterize the structural basis for MHC-SEA interaction we have examined the role of the alpha-helical regions of the class II alpha and beta chains in SEA function. Using the synthetic peptide approach, we have found that both alpha-helical regions are required for SEA-induced proliferation. Their corresponding peptides directly bound SEA. Although the beta-chain peptides were able to inhibit SEA binding to human and mouse cells, the alpha-chain peptides were not. The data suggest that the alpha-helices along both sides of the hypothetical class II MHC molecule binding cleft are required for SEA-induced function, whereas the beta-chain alpha-helix is sufficient for SEA binding. A model of superantigen presentation is proposed wherein the MHC beta chain, possibly region 70-80, interacts with SEA region 1-45, whereas another region of SEA binds region 51-80 of the alpha chain.

The I-A beta b region (65-85) is a binding site for the superantigen, staphylococcal enterotoxin A

Ia antigen is a receptor for the superantigen staphylococcal enterotoxin A (SEA). Peptides I-A beta b(30-60), I-A beta b(50-70), I-A beta b(65-85), and I-A beta b(80-100) of the MHC class II antigen beta chain on mouse (H-2b) accessory cells were synthesized. Only I-A beta b(65-85) inhibited SEA binding to the mouse B-cell lymphoma line, A20 (H-2d) and the human Burkitt's lymphoma line, Raji (HLA-DR). The I-A beta b(65-85) sequence is a predicted alpha-helix along the hypothetical antigen binding cleft of the Ia molecule. I-A beta b(65-85) also directly and specifically bound both the intact SEA molecule and its Ia binding site, represented by the peptide SEA(1-45). The results suggest that I-A beta b region (65-85) is a necessary site for Ia molecular interaction with the superantigen SEA. Further, the data suggest that the same helical region of other Ia antigens binds SEA irrespective of haplotype and species.

Site of nonrestrictive binding of SEA to class II MHC antigens

We have used the synthetic peptide approach to show that the N-terminal 45-amino acids of staphylococcal enterotoxin A (SEA), SEA(1-45), constitute an important part of its binding site on class II major histocompatibility complex (MHC) molecules. SEA(1-45) and to a lesser extent SEA(1-27) were able to displace SEA from HLA-DR on Raji cells as assessed by flow cytometry and to compete with radiolabeled SEA for interaction with HLA-DR in a direct binding assay. Specific binding of SEA to Ia on murine A-20 cells could be inhibited by the same peptides [i.e. SEA(1-45) greater than SEA(1-27)] that blocked binding to HLA-DR. Therefore, different class II MHC molecules associate with the same functional site on SEA. Further, an ELISA system was used to demonstrate that SEA(1-45) is able to directly bind to a mouse synthetic I-A beta b peptide, I-A beta b (65-85), which contains a binding site of the class II MHC molecule involved in SEA presentation to T cells. Thus, we have localized a site on SEA that is involved in selective surface association with class II MHC antigens and identified the region on the class II MHC antigen to which that site binds.

Localization of an immune functional site on staphylococcal enterotoxin A using the synthetic peptide approach

Using the synthetic peptide approach, we have identified a part of the staphylococcal enterotoxin A (SEA) molecule that is responsible for stimulation of T cell proliferation and induction of the lymphokine IFN-gamma. Peptides were synthesized corresponding to amino acids 1 to 27, SEA(1-27), and 28 to 45, SEA(28-45). Both peptides were tested for direct competition with SEA for blockage of SEA induced proliferation and production of IFN-gamma by T cells. Further, antibodies were produced to the peptides and tested for their ability to bind to SEA and block SEA function. SEA (1-27), but not SEA (28-45), blocked proliferation of human peripheral T cells and induction of IFN-gamma by the T cell line, L12-R4. The inhibitory effects were specific, because SEA (1-27) did not inhibit the induction of T cell proliferation by the mitogen PHA. Consistent with the direct inhibition of function, antibodies to SEA (1-27), but not SEA (28-45), neutralized the mitogenic activity of SEA on human PBL. The data suggest that a functional site on SEA that is responsible for its modulation of T cell function involves the N-terminal 27 amino acids. Residues 1 to 27 of SEA could potentially interact at either the level of the TCR or may block the proposed binding of SEA to class II MHC Ag, based on recent data showing that these molecules are involved in SEA-induced proliferation.

Localization of an immune functional site on staphylococcal enterotoxin A using the synthetic peptide approach

Using the synthetic peptide approach, we have identified a part of the staphylococcal enterotoxin A (SEA) molecule that is responsible for stimulation of T cell proliferation and induction of the lymphokine IFN-gamma. Peptides were synthesized corresponding to amino acids 1 to 27, SEA(1-27), and 28 to 45, SEA(28-45). Both peptides were tested for direct competition with SEA for blockage of SEA induced proliferation and production of IFN-gamma by T cells. Further, antibodies were produced to the peptides and tested for their ability to bind to SEA and block SEA function. SEA (1-27), but not SEA (28-45), blocked proliferation of human peripheral T cells and induction of IFN-gamma by the T cell line, L12-R4. The inhibitory effects were specific, because SEA (1-27) did not inhibit the induction of T cell proliferation by the mitogen PHA. Consistent with the direct inhibition of function, antibodies to SEA (1-27), but not SEA (28-45), neutralized the mitogenic activity of SEA on human PBL. The data suggest that a functional site on SEA that is responsible for its modulation of T cell function involves the N-terminal 27 amino acids. Residues 1 to 27 of SEA could potentially interact at either the level of the TCR or may block the proposed binding of SEA to class II MHC Ag, based on recent data showing that these molecules are involved in SEA-induced proliferation.

Causal association of interferon-gamma with tumor regression

Mouse interferon-gamma (MuIFN-gamma) can cause the rejection of malignant cells in vivo. The evidence presented here in support of this claim includes, first, that spontaneous regression of MSC sarcomas was associated with high intratumoral concentrations of endogenously-produced MuIFN-gamma. By contrast, progressively growing, lethal neoplasms of the same kind invariably contained very little IFN-gamma. Second, spontaneously regressing MSC sarcomas were converted into progressively growing, lethal neoplasms by injecting mice with a monoclonal antibody that neutralized the biological effects of endogenous IFN-gamma. Another monoclonal antibody that bound to, but did not neutralize, mouse IFN-gamma had no effect on the course of tumor regression. Together, these data causally relate MuIFN-gamma to the successful rejection of malignant cells in vivo. They also suggest that findings of poor therapeutic efficacy for IFN-gamma are probably attributable to problems other than an intrinsic lack in the biological activity of the lymphokine.

A positive feedback loop for staphylococcal enterotoxin-A-stimulated IFN-gamma production requires macrophage immune-associated antigen upregulation

The C57Bl/6-derived T cell line, L12-R4, produced murine interferon-gamma (IFN gamma) in response to mitogenic stimulation by phorbol myristate acetate (PMA) or concanavalin A (Con A), but not by staphylococcal enterotoxin A (SEA). Low levels of IFN gamma were produced by SEA stimulation of L12-R4 cells cocultured with C57Bl/6 bone marrow macrophages (BMM). Significantly increased yields of IFN gamma resulted from 48-hour pretreatment of the BMM with recombinant IFN gamma (100 U/ml) prior to coculture. Polyclonal anti-IFN gamma and anti-IFN alpha/beta were used to characterize the interferon as IFN gamma. Paraformaldehyde (0.1%) treatment of IFN gamma-pretreated BMM did not affect IFN gamma production, suggesting that processing of SEA was not required. IFN gamma treatment of BMM resulted in significantly increased expression of immune-associated (Ia) antigen as determined by flow cytometric analysis, suggesting that the accessory cell role of BMM involved Ia antigen. Polyclonal anti-Ia antibody selectively inhibited the production of IFN gamma by SEA-stimulated whole spleen cell cultures, consistent with the necessity of Ia antigen for BMM help in SEA induction of IFN gamma. More interestingly, induction of IFN gamma. These findings suggest that Ia antigen is necessary for BMM accessory function in SEA induction of IFN gamma. More interestingly, the results implicate class II molecules in a positive feedback loop for IFN gamma production by SEA.

Steric relationship of amino-terminal and carboxy-terminal domains of murine interferon-gamma as assessed by monoclonal antibodies

Spleen cells from a hamster immunized with murine interferon-gamma (IFN-gamma) carboxy-terminal (95-133) synthetic peptide [IFN-gamma (95-133)] conjugated to keyhole limpet hemocyanin (KLH) were fused with mouse myeloma cells, resulting in the production of an anti-IFN-gamma (95-133) monoclonal antibody, which reacted with IFN-gamma. This monoclonal antibody bound [125I]IFN-gamma in a dose-dependent and reversible fashion, and neutralized the antiviral and macrophage priming activities of IFN-gamma. Antibody-antibody competition for [125I]IFN-gamma binding, using this carboxy-terminal-specific antibody and two previously described amino-terminal-specific monoclonal antibodies, indicated that the carboxy-terminal-specific monoclonal antibody competed only with itself and that the two amino-terminal-specific monoclonal antibodies similarly competed only with each other for [125I]IFN-gamma. The data suggest that the amino- and carboxy-terminal IFN-gamma domains important for function are sterically distant from one another, and suggest the intriguing possibility that interaction of IFN-gamma with its receptor may involve more than one binding site on the IFN-gamma molecule.

Use of synthetic peptides to identify an N-terminal epitope on mouse gamma interferon that may be involved in function

We previously have assigned N-terminal specificity to three hamster monoclonal antibodies (mAbs I, II, and III) produced to mouse recombinant gamma interferon (IFN-gamma), based on the ability of the N-terminal peptide IFN-gamma-(1-39) to block binding of 125I-labeled IFN-gamma (125I-IFN-gamma) and on the ability of these antibodies to bind 125I-IFN-gamma-(1-39). Only mAb I blocked function and binding to the IFN-gamma receptor, suggesting that it may bind to a region of the molecule involved in interaction with the receptor. To further define the epitope specificities of the antibodies, a series of N-terminal peptides were synthesized and tested for their ability to block antibody binding of 125I-IFN-gamma. Peptides IFN-gamma-(1-39), IFN-gamma-(1-20), IFN-gamma-(3-20), and IFN-gamma-(5-20) inhibited binding of 125I-IFN-gamma by mAb I in order of decreasing effectiveness, while peptide IFN-gamma-(7-20) was without effect. Peptides IFN-gamma-(1-39), IFN-gamma-(1-20), and IFN-gamma-(3-20) also inhibited binding of 125I-IFN-gamma by mAb II but were less effective when compared with their inhibition of mAb I. IFN-gamma-(5-20) and IFN-gamma-(7-20) did not inhibit binding by mAb II. Peptides IFN-gamma-(1-10), IFN-gamma-(10-30), and IFN-gamma-(21-44) did not inhibit either mAb I or mAb II. While IFN-gamma-(1-39) and IFN-gamma-(10-30) inhibited binding by mAb III, neither IFN-gamma-(1-20) nor any of its truncated forms were inhibitory. All three antibodies had similar Kd values for 125I-IFN-gamma. A prediction of the secondary structure of the molecule and the peptide inhibition data suggest that the epitope (possible receptor binding region) for mAb I involves a loop in the area containing residues 12-20, with sequences N-terminal to these residues possibly stabilizing the loop conformation. Direct evidence that the N-terminal 1-39 region of IFN-gamma is important in receptor binding was the observation that IFN-gamma-(1-39), but not the C-terminal IFN-gamma-(95-133), competed with 125I-IFN-gamma for the receptor on mouse L cells. IFN-gamma-(1-39) also specifically blocked IFN-gamma antiviral activity at concentrations that blocked binding to the receptor. The fact that IFN-gamma-(1-39) was the only peptide that blocked both IFN-gamma binding to receptor and function is consistent with the antibody competition data, where it was the most effective peptide in blocking binding of 125I-IFN-gamma by the N-terminal-specific mAbs. The combination of peptide mapping of epitope specificities and receptor competition should further help define the structural basis for IFN-gamma action.

Phospholipase A2 treatment of lymphocytes provides helper signal for interferon-gamma induction. Evidence for second messenger role of endogenous arachidonic acid

To examine the role of endogenous arachidonic acid (AA) as the possible second messenger signal in interferon-gamma (IFN-gamma) production, helper cell-depleted mouse spleen cell cultures were treated with the enzyme phospholipase A2 (PLA2). Treatment with PLA2 from several different animal sources at concentrations between 10 and 300 U/ml resulted in complete, dose-dependent restoration of competence for IFN-gamma production. By comparison, phospholipase C (PLC) from several different species failed to restore competence at concentrations between 0.3 and 30 U/ml; the inability of PLC to provide the helper signal for induction of IFN-gamma was not due to cytotoxicity. Since PLA2 provides competence for IFN-gamma production by sn-2 hydrolysis, it was of interest to identify eicosanoids and other lipids released from [3H]-AA labeled cells by PLA2 and PLC. Treatment of spleen cells with PLA2, but not PLC, resulted in the appreciable release of AA only. Sufficient AA was released from spleen cells for restoration of competence for production of IFN-gamma. All glycerol-derived cell membrane phospholipids examined (phosphatidylethanolamine, -inositol, -choline, and -serine) incorporated labeled AA which was releasable by treatment with PLA2. The data support and extend previous studies which suggested that AA plays a pivotal role in mediation of the interleukin 2 helper signal for IFN-gamma production.

Phospholipase A2 treatment of lymphocytes provides helper signal for interferon-gamma induction. Evidence for second messenger role of endogenous arachidonic acid

To examine the role of endogenous arachidonic acid (AA) as the possible second messenger signal in interferon-gamma (IFN-gamma) production, helper cell-depleted mouse spleen cell cultures were treated with the enzyme phospholipase A2 (PLA2). Treatment with PLA2 from several different animal sources at concentrations between 10 and 300 U/ml resulted in complete, dose-dependent restoration of competence for IFN-gamma production. By comparison, phospholipase C (PLC) from several different species failed to restore competence at concentrations between 0.3 and 30 U/ml; the inability of PLC to provide the helper signal for induction of IFN-gamma was not due to cytotoxicity. Since PLA2 provides competence for IFN-gamma production by sn-2 hydrolysis, it was of interest to identify eicosanoids and other lipids released from [3H]-AA labeled cells by PLA2 and PLC. Treatment of spleen cells with PLA2, but not PLC, resulted in the appreciable release of AA only. Sufficient AA was released from spleen cells for restoration of competence for production of IFN-gamma. All glycerol-derived cell membrane phospholipids examined (phosphatidylethanolamine, -inositol, -choline, and -serine) incorporated labeled AA which was releasable by treatment with PLA2. The data support and extend previous studies which suggested that AA plays a pivotal role in mediation of the interleukin 2 helper signal for IFN-gamma production.

Induction of interferon by transformed cells: inhibition by retinoic acid

Retinoic acid (RA) inhibited transformed mouse L-929 and human WISH cell induction of interferon alpha/beta production by nonsensitized mouse spleen cells. The RA effect was both time and dose dependent and acted in near physiologic concentrations. The results suggest that the effect is due to a modulation of a previously described transformed cell surface associated glycoprotein IFN inducer.

Epitope and functional specificity of monoclonal antibodies to mouse interferon-gamma: the synthetic peptide approach

Spleen cells from hamsters immunized with recombinant mouse interferon-gamma (IFN-gamma) were fused with mouse myeloma cells, resulting in the production of four anti-IFN-gamma monoclonal antibodies. Binding of 125I-IFN-gamma by these protein A-bound antibodies was specifically blocked by cold IFN-gamma. Binding by three of these antibodies was also blocked by a synthetic peptide corresponding to the N-terminal 1-39 amino acids of IFN-gamma, whereas a corresponding C-terminal (95-133) peptide had no effect on binding. The N-terminal specificity of these three antibodies was confirmed by their specific binding of 125I-N-terminal (1-39) peptide. One of the N-terminal specific monoclonal antibodies inhibited both antiviral and macrophage priming (for tumor cell killing) activities of IFN-gamma, whereas the other two had no effect on either biologic function. The selectivity of the inhibition of IFN-gamma function was not due to a differential ability of the N-terminal specific antibodies to bind IFN-gamma. Blocking experiments with cold IFN-gamma and N-terminal peptide suggest that the epitope specificities of the monoclonal antibodies could be determined by the conformational or topographic structure of IFN-gamma. An exact determination of the epitope specificity of the monoclonal antibody that inhibited IFN-gamma function could provide insight into the structural basis for the role of the N-terminal domain in the biologic function of IFN-gamma. Polyclonal antibodies to either the N-terminal or the C-terminal peptides also inhibited both the antiviral and the macrophage-priming activities of IFN-gamma. All of the antibodies that inhibited IFN-gamma function also blocked binding of IFN-gamma to membrane receptor on cells, whereas antibodies that did not block function also did not inhibit binding. The data suggest that both the N-terminal and the C-terminal domains of IFN-gamma play an important role in its antiviral and macrophage-priming functions, possibly in a cooperative manner.

Epitope and functional specificity of monoclonal antibodies to mouse interferon-gamma: the synthetic peptide approach

Spleen cells from hamsters immunized with recombinant mouse interferon-gamma (IFN-gamma) were fused with mouse myeloma cells, resulting in the production of four anti-IFN-gamma monoclonal antibodies. Binding of 125I-IFN-gamma by these protein A-bound antibodies was specifically blocked by cold IFN-gamma. Binding by three of these antibodies was also blocked by a synthetic peptide corresponding to the N-terminal 1-39 amino acids of IFN-gamma, whereas a corresponding C-terminal (95-133) peptide had no effect on binding. The N-terminal specificity of these three antibodies was confirmed by their specific binding of 125I-N-terminal (1-39) peptide. One of the N-terminal specific monoclonal antibodies inhibited both antiviral and macrophage priming (for tumor cell killing) activities of IFN-gamma, whereas the other two had no effect on either biologic function. The selectivity of the inhibition of IFN-gamma function was not due to a differential ability of the N-terminal specific antibodies to bind IFN-gamma. Blocking experiments with cold IFN-gamma and N-terminal peptide suggest that the epitope specificities of the monoclonal antibodies could be determined by the conformational or topographic structure of IFN-gamma. An exact determination of the epitope specificity of the monoclonal antibody that inhibited IFN-gamma function could provide insight into the structural basis for the role of the N-terminal domain in the biologic function of IFN-gamma. Polyclonal antibodies to either the N-terminal or the C-terminal peptides also inhibited both the antiviral and the macrophage-priming activities of IFN-gamma. All of the antibodies that inhibited IFN-gamma function also blocked binding of IFN-gamma to membrane receptor on cells, whereas antibodies that did not block function also did not inhibit binding. The data suggest that both the N-terminal and the C-terminal domains of IFN-gamma play an important role in its antiviral and macrophage-priming functions, possibly in a cooperative manner.

Control of Polyomavirus T-antigen and DNA synthesis in mouse embryo fibroblast cells by vitamin A

Vitamin A (retinoic acid, 10(-6) M) treatment of confluent mouse embryo cells for only 7 h resulted in optimal inhibition of Polyomavirus replication. Depending upon the input multiplicity of virus, one could wait until between 12 and 18 h postinfection to add vitamin A and still observe maximal inhibition of virus yields. Taken together, and assuming the same kinetics before and after virus infection, these results suggested that the inhibitory action of vitamin A occurred between 19 and 25 h into the Polyomavirus replication cycle. In this model system, such a time corresponded to the onset of T-antigen expression and virus-induced cellular DNA synthesis. Analysis of both viral and virus-induced cellular DNA synthesis by the method of Hirt (J. Mol. Biol., 26: 365-369, 1967) and by cesium chloride gradients suggested that vitamin A preferentially inhibited viral, more than virus-induced cellular, DNA synthesis in confluent cell monolayers. Vitamin A also concomitantly inhibited Polyomavirus T-antigen expression in such confluent cultures. In contrast, viral DNA synthesis and infectious virus yields were not significantly inhibited by vitamin A in subconfluent cell cultures. The antagonistic effect of vitamin A on Polyomavirus replication in confluent monolayers could be blocked with cycloheximide, a reversible protein synthesis inhibitor. This suggested that vitamin A inhibition of Polyomavirus replication was indirect and mediated by a newly synthesized protein. Taken together, these results suggest that vitamin A induced a protein in confluent, but not subconfluent, cells, which blocked the expression of Polyomavirus T-antigen. Decreased amounts of T-antigen most likely reduced Polyomavirus and cellular DNA synthesis and virus yield.

Vitamin A inhibition of polyoma virus replication

Vitamin A (retinoic acid) inhibited polyoma virus replication in confluent mouse embryo cells. A significant, dose dependent inhibition was observed when cell monolayers were pretreated with concentrations of vitamin A (10(-8) to 10(-6) M) thought to approximate those found in vivo. This inhibitory effect could be reduced by increasing the input multiplicity of infection. Growth curves of polyoma virus in the presence and absence of vitamin A suggested that vitamin A actually inhibited, and did not simply delay, virus replication. The cell density dependence of this inhibitory effect suggested its association with the prevailing level of cellular DNA synthesis. Vitamin A caused a significant decrease in overall (viral plus cellular) DNA synthesis. Other viruses which do not require induction of host cell DNA synthesis for their replication in confluent, non-dividing cells were not inhibited by vitamin A. These results are consistent with the known inhibitory effects of vitamin A on papovavirus infection in vivo and suggest a mechanism of vitamin A action at the level of the infected cell.

Retinoic acid: enhancement of a tumor and inhibition of interferon's antitumor action

The effect of trans-retinoic acid on the growth of P388 lymphoid tumors in inbred female DBA/2 mice in the presence or absence of interferon (FN) treatment was studied. This acid derivative of vitamin A enhanced local tumor growth. trans-retinoic acid also partially reversed IFN protection against tumor growth and mortality.

Ehlers-Danlos syndrome during pregnancy: a case report and review of the literature

Since Ehlers-Danlos syndrome encompasses a wide spectrum of disease and only has an estimated incidence of approximately 1:150,000 (Beighton, 1968a), there is a paucity of data from large studies on which to base firm conclusions about the risks of pregnancy in association with the syndrome. Most reports refer to women with the gravis (type I) and ecchymotic (type IV) forms, unlike pregnancy in association with the mitis (type II), which is rarely reported despite the fact that it constitutes 35 per cent of all cases of Ehlers-Danlos syndrome (Beighton, 1970). We suspect this is because complications with the mitis form are rare. Women with the two severe forms of the syndrome, mentioned above, risk hemorrhage, severe trauma at delivery, and preterm labor, but whether this is the case in the mitis form is unproved. Our patient's course was uneventful, delivery by cesarean section being undertaken because of her hip fixity. Tyson (1972) suggested that delivery by cesarean section was indicated in all cases of Ehlers-Danlos syndrome, but this pertains to the severe forms of the syndrome. The question of vaginal delivery in the mitis form remains unanswered. We would hope that in future reports of pregnancy in association with Ehlers-Danlos syndrome that patients are classified according to type so that prognosis, particularly in the mitis form, can be more accurately assessed.