Depressive Symptoms in Later Life in China: Situating "Long Arm" of Child Physical Maltreatment Within a Family Context

Objective: This article intends to reveal the long-term effects of physical maltreatment in childhood on depressive symptoms in later life in China. Methods: Data were drawn from the China Health and Retirement Longitudinal Study (CHARLS). 8676 respondents aged 45 and older were included in the study. In this study, we use ordinary least squares (OLS) regression models to estimate the long-term impact on children of physical punishment from their parents. Results: We found that individuals who recalled being hit by their mother in early life reported more depressive symptoms than those who recalled being punished by their father. Difficult family contexts (e.g., comparative poverty, family violence, and parent's poor mental health) had a weak association with higher risk of reporting physical maltreatment and more depressive symptoms among respondents in later life. Conclusion: This article extended the exploration of the long-term impact of child physical maltreatment beyond adolescence and into until later adult life. Effective policies to protect children from maltreatment in the form of physical punishment require further attention to the challenges posed by tradition and culture.

Definitions of recovery and reintegration across the first year: A qualitative study of perspectives of persons with spinal cord injury and caregivers

STUDY DESIGN

Longitudinal, qualitative cohort study.

OBJECTIVES

To understand how people with newly acquired spinal cord injury (PWS) and their support person (SP) define recovery and successful community reintegration (CR) across the first 12 months post-injury (mpi) and their satisfaction with the rate of recovery and reintegration experienced.

SETTING

Academic and Veterans hospitals in Midwest USA.

METHODS

In-depth, semi-structured interviews were conducted in two cohorts of PWS and SP during the initial inpatient rehabilitation stay, at 6 mpi, and at 12 mpi. Recordings were transcribed; four authors independently undertook line-by-line coding. The team discussed codes to reach consensus and synthesize into broader themes within the International Classification of Function, Disability, and Health and Transformative frameworks.

RESULTS

Data are reported on 23 PWS and 21 SP. PWS and SP are similar in defining recovery as gaining motor function and achieving independence. However, SP more frequently define recovery in terms of maintaining positivity and emotional recovery. At 12 mpi both groups shift to define recovery according to progress. Social roles, being active, and employment are persistent themes of how PWS and SP define successful CR. However, SP also frequently define successful CR as reestablishing identity and emotional adjustment. Veterans with SCI less frequently defined successful CR as employment.

CONCLUSIONS

This study is the first to reveal how PWS and SP define recovery and reintegration during the first 12 mpi. Given decreasing lengths of stay, this information can be used to tailor rehabilitation strategies during the critical first year of injury to optimize recovery.

Seeking sufficient and appropriate care during the first year after spinal cord injury: a qualitative study

STUDY DESIGN

Longitudinal qualitative study, based on a constructivist grounded theory and transformative approach.

OBJECTIVES

This study investigated experiences of individuals with spinal cord injury (SCI) while navigating rehabilitation, resources for recovery, and community reintegration during the first year after injury.

SETTING

An acute inpatient rehabilitation facility in the Midwest United States.

METHODS

In-depth, semi-structured interviews were conducted with 20 individuals with newly-acquired SCI. Interviews were conducted approximately every other month for one year, beginning at acute inpatient rehabilitation. Data were analyzed and interpreted using a constructivist grounded theory approach and transformative paradigm, which examines power and social structures within and across institutions and gives voice to people at risk for marginalization.

RESULTS

Participants experienced variable post-injury trajectories, with an average of four transitions within and across healthcare institutions in the first three months. Half of the cohort was discharged to a skilled nursing facility (SNF). Emergent themes included discharge (un)readiness; length of stay uncertainty and insurance impacts; challenges choosing a SNF including time-sensitive decisions; and early cessation of therapy in the SNF. Participants experienced resource navigation challenges such as communication/information access barriers and contending with many concerns at once.

CONCLUSIONS

The experiences of this cohort reveal significant challenges to attaining sufficient and appropriate rehabilitation. Acute inpatient rehabilitation is a critical aspect of recovery, but does not ensure sufficient intervention for maximization of functional skills and community reintegration. Innovative rehabilitation models need to be developed for positive impacts on successful transition to independent living in the community.

Reimagining Children's Rights in the US

IMPORTANCE

The US faces a pivotal moment of opportunity and risk regarding issues affecting children (aged 0-17 years). Although the US remains the only United Nations member state to not have ratified the Convention on the Rights of the Child (CRC), a child rights framework is essential for child health professionals seeking to advance many issues affecting children in the US. The Reimagining Children's Rights project (2020-2021) conducted an in-depth environmental scan of relevant literature and policy analysis using the Three Horizons design process to assess strategies that could advance the rights and well-being of children in the US. The project was overseen by a steering committee and informed by an advisory committee composed of youth leaders and experts in children's rights, advocacy, health, law, and a range of child-specific issues (eg, youth justice, early childhood development), who provided expert input on strategic considerations for advancing children's rights.

OBSERVATIONS

Seven findings about advancing children's rights in the US are notable, all reflecting current gaps and opportunities for using a whole-child rights framework in the US, even without formal adoption of the CRC. Actionable strategies, tactics, and tools to leverage sustainable change in the multitude of issue areas can advance the current state of children's rights. High-potential strategies for catalyzing advancement of children's rights include youth activism, innovations in governance and accountability, legislative action, impact litigation, place-based initiatives, education and public awareness, alignment with other children's movements, and research. The child rights framework is unifying and adaptive to future unforeseen challenges.

CONCLUSIONS AND RELEVANCE

Children's rights provide a powerful, synergistic framework for child health professionals-in partnership with youth and other leaders-to increase equity and protect the rights and well-being of all children in the US.

The Long Arm of Child Maltreatment and Mental Health in Later Life: The Effects of Maltreatment and Family Context?

Purpose. This article examines the role of family context in shaping the influence of childhood maltreatment on later life psychological well-being in the cultural context of Chinese society. Method. Data were drawn from the China Health and Retirement Longitudinal Study (CHARLS) baseline. Maltreatment was measured by corporal punishment by either mother or father in childhood. We used family violence, parents’ family socioeconomic status (SES) and mental health to represent family context. Result. Our ordinary least square regression analysis shows that corporal punishment administered by a mother was associated with higher depressive symptoms (b=0.308, p<0.05) in later life while being hit by father did not result in higher depressive symptoms. Family contexts had residual (“long arm”) influence on respondents’ mental health: violence in the family, including being hit by siblings (b=0.657, p<0.001) and witnessing violence between parents (b=0.658, p<0.001) contributed significantly to higher depressive symptoms. Conclusion. Corporal punishment by parents had long term effects on mental health of their children in later life. Cultural values, such as filial piety did not eliminate the negative impacts of being hit in childhood on mental health in later life. Family contexts including violence between parents also played important roles in shaping the relationship between child maltreatment and mental health in later life. Implication. Our study offers important insights about the complex matrix of cultural traditions, social circumstances and diversity in dealing with child rearing stress and their consequences for later life mental health.

Effects of pro-inflammatory cytokines on cannabinoid CB1 and CB2 receptors in immune cells

Aims

To investigate the regulation of cannabinoid receptors CB₁ and CB₂ on immune cells by pro‐inflammatory cytokines and its potential relevance to the inflammatory neurological disease, multiple sclerosis (MS).

CB₁ and CB₂ signalling may be anti‐inflammatory and neuroprotective in neuroinflammatory diseases. Cannabinoids can suppress inflammatory cytokines but the effects of these cytokines on CB₁ and CB₂ expression and function are unknown.

Methods

Immune cells from peripheral blood were obtained from healthy volunteers and patients with MS. Expression of CB₁ and CB₂mRNA in whole blood cells, peripheral blood mononuclear cells (PBMC) and T cells was determined by quantitative real‐time polymerase chain reaction (qRT‐PCR). Expression of CB₁ and CB₂ protein was determined by flow cytometry. CB₁ and CB₂ signalling in PBMC was determined by Western blotting for Erk1/2.

Results

Pro‐inflammatory cytokines IL‐1β, IL‐6 and TNF‐α (the latter likely NF‐κB dependently) can upregulate CB₁ and CB₂ on human whole blood and peripheral blood mononuclear cells (PBMC). We also demonstrate upregulation of CB₁ and CB₂ and increased IL‐1β, IL‐6 and TNF‐α mRNA in blood of patients with MS compared with controls.

Conclusion

The levels of CB₁ and CB₂ can be upregulated by inflammatory cytokines, which can explain their increase in inflammatory conditions including MS.

Rights and the role of family engagement in child welfare: an international treaties perspective on families' rights, parents' rights, and children's rights

According to international human rights treaties, what rights do family members, parents, and children have in family engagement in child welfare decision-making? A socio-legal analytical approach produces a typology of rights, then applies the typology to eight countries' approaches to family engagement to show that strong bundles of rights are available in some countries, but not in others. This study reveals international treaties have articulated many rights necessary to family engagement, but some rights are missing.

Accelerated thymocyte maturation in IL-12Rβ2-deficient mice contributes to increased susceptibility to autoimmune inflammatory demyelination

IL-12Rβ2(-/-) mice, which are unresponsive to IL-12, develop severe experimental autoimmune encephalomyelitis (EAE). The mechanisms for enhanced autoimmunity are incompletely understood. We report that in IL-12Rβ2(-/-) mice, thymocytes undergo markedly accelerated maturation. This occurs at the transition from a double positive (DP) to a single positive (SP) phenotype, resulting in higher numbers of CD4 and CD8 SP cells, and to a lesser extent at the transition from double negative (DN) to DP cells. Accelerated maturation is observed in mice injected with anti-CD3 to mimic pre-T-cell receptor stimulation, and also in mice immunized with myelin oligodendrocyte glycoprotein (MOG) peptide to induce EAE.

Shifts in Public-Private Provision of Retirement Income

In the midst of governmental budget battles in the late 20th century, many countries' public pension programs faced challenges. In some countries, private provision grew in importance, but shifts from public to private retirement income did not automatically occur. The author examined retirement income programs in Belgium, Canada, Denmark, and New Zealand from 1980 to 1995 to evaluate the components of pension programs, both public and private, that were or were not protected from cutbacks. The author explores ways in which the public sector cooperates with the nonpublic sectors to form retirement income policy in these four countries. He then evaluates the explanatory frameworks scholars use to study social policy change by examining parts of pension programs that were maintained and those that were reduced. The author suggests that some factors take on greater explanatory importance for the diminution and durability of pension programs when both public and private pension programs are considered.

The protease inhibitor, Bowman-Birk Inhibitor, suppresses experimental autoimmune encephalomyelitis: a potential oral therapy for multiple sclerosis

Available treatments for multiple sclerosis (MS) require frequent injections and have significant side effects. Proteases generated during inflammation are involved in the induction of tissue damage during inflammatory demyelination in the central nervous system (CNS). The Bowman-Birk Inhibitor (BBI), a soy-derived protease inhibitor with anti-carcinogenic and anti-inflammatory properties, has been shown to be well tolerated in clinical trials for pre-cancerous conditions, such as oral leukoplakia and the inflammatory disease, ulcerative colitis. We hypothesized that BBI may modulate experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The BBI concentrate (BBIC), a soybean extract enriched in BBI, was administered to myelin basic protein (MBP)-immunized Lewis rats by gastric gavage in different treatment regimens, during the induction or the effector phase of disease. BBIC significantly delayed disease onset and suppressed disease severity, clinically and pathologically, in all treatment protocols. Both in vitro and ex vivo, BBIC inhibited MBP-specific proliferation of lymph node cells. BBIC reduced the activity of matrix metalloproteinase (MMP)-2 and -9 in spleen cell supernatants and was detected in the CNS of treated rats. BBIC suppresses EAE, it can be administered orally, and it is safe and relatively inexpensive. It may have a therapeutic role in patients with MS.

A second opinion: rethinking the public-private dichotomy for health insurance

Does the public-private dichotomy effectively describe health insurance systems in the advanced industrialized democracies? Is the boundary separating the public and private sectors accurate for studies o f social policy formation and cutback? This article has three goals. The first is to discuss reasons for reconsidering the public-private dichotomy, as it applies to health insurance systems. The second is to offer a reconceptualization of the public-private demarcation useful for analyses of health insurance systems; the author presents four sectors that may illuminate patterns of health insurance for different OECD countries: the social, individual, public, and market sectors. The third goal is to present results using a new methodological approach useful for studying complex social phenomena: the fuzzy-set approach, which allows researchers to treat social phenomena as partially belonging to more than one category. This approach is employed to demonstrate that health insurance provision rarely is solely public or private, but is formed by a combination of sectors. Underlying these three goals is the contention that comparative and historical sociological researchers can offer innovative approaches to the study of health insurance and the interests served by public and nonpublic health insurance programs through reconceiving the public-private dichotomy.

Combinatorial peptide libraries and biometric score matrices permit the quantitative analysis of specific and degenerate interactions between clonotypic TCR and MHC peptide ligands

The interaction of TCRs with MHC peptide ligands can be highly flexible, so that many different peptides are recognized by the same TCR in the context of a single restriction element. We provide a quantitative description of such interactions, which allows the identification of T cell epitopes and molecular mimics. The response of T cell clones to positional scanning synthetic combinatorial libraries is analyzed with a mathematical approach that is based on a model of independent contribution of individual amino acids to peptide Ag recognition. This biometric analysis compares the information derived from these libraries composed of trillions of decapeptides with all the millions of decapeptides contained in a protein database to rank and predict the most stimulatory peptides for a given T cell clone. We demonstrate the predictive power of the novel strategy and show that, together with gene expression profiling by cDNA microarrays, it leads to the identification of novel candidate autoantigens in the inflammatory autoimmune disease, multiple sclerosis.

Glatiramer acetate induces a Th2-biased response and crossreactivity with myelin basic protein in patients with MS

Glatiromer acetate (GA) is an approved treatment for multiple sclerosis (MS). The proposed mechanism of action is the induction of GA-specific T cells characterized by protective anti-inflammatory Th2 response. We tested this hypothesis in 11 MS patients treated with GA from 1-19 months. Interferon-gamma and IL-5 (markers of Th1 and Th2 responses respectively) were assayed by ELISA in GA-specific T-cell lines (TCL) supernatants. Th1/Th2 bias was defined based on the ratio of IFN-gamma/IL-5 secretion. Fifty-eight pre-treatment and 75 on-treatment GA-specific TCL were generated. On-treatment mean IL-5 levels in GA-TCL increased significantly, whereas those for IFN-gamma were markedly reduced. Consequently, the ratio of IFN-gamma IL-5 also shifted in favor of a Th2 response. The percentage of GA-TCL classified as Th1 was decreased, whereas those classified as Th2 increased on-treatment as compared to pre-treatment. Some GA-specific TCL, (approximately 25%) generated during treatment secreted predominantly IL-5 in response to MBP and the immunodominant MBP peptide 83-99, indicating that these crossreactive antigens can act as partial agonists for GA-reactive TCL. These results strongly suggest that the mechanism of action of GA in MS involves the induction of crossreactive GA-specific T cells with a predominant Th2 cytokine profile.

Molecular mimicry and antigen-specific T cell responses in multiple sclerosis and chronic CNS Lyme disease

The concept of molecular mimicry provides and elegant framework as to how cross-reactivity between antigens from a foreign agent with self proteins may trigger autoimmune diseases. While it was previously thought that sequence and structural homology between foreign and self proteins or the sharing of T cell receptor (TCR) and MHC-binding motifs are required for molecular mimicry to occur, we have shown that even completely unrelated peptide sequences may lead to cross-recognition by T cells. The use of synthetic combinatorial peptide libraries in the positional scanning format (PS-SCL) together with novel biometric prediction approaches has allowed us to describe the recognition profiles of individual autoreactive T cell clones (TCC) with unprecedented accuracy. Through studies of myelin-specific TCC as well as clones from the nervous system of patients suffering from chronic central nervous (CNS) Lyme disease it has become clear that at least some T cells are more degenerate than previously anticipated. These data will not only help us to redefine what constitutes specific T cell recognition, but also allow us to study in more detail the biological role of molecular mimicry. A recent clinical trial with an altered peptide ligand (APL) of one of the candidate myelin basic protein (MBP) epitopes in MS (amino acids 83-99) has shown that such a modified MBP peptide may not only have therapeutic efficacy, but also bears the potential to exacerbate disease. Thus, we provide firm evidence that the basic principles of cross-recognition and their pathogenetic significance are relevant in MS.

T cells, cytokines, and autoantigens in multiple sclerosis

In multiple sclerosis (MS), inflammatory demyelination in the central nervous system is thought to be initiated by T cells that recognize myelin antigens. T cells are the main regulators of acquired immunity and are involved in the pathogenesis of several organ-specific autoimmune diseases. This review provides an overview of recent studies on the role of T cells in autoimmune demyelination. Because autoreactive T cells are normally present in the mature repertoire of T cells in the blood and lymphoid organs of MS patients, but also in normal controls, particular attention is devoted to the mechanisms of activation and the functional phenotype of such T cells in patients with MS. The role of cytokines as effector molecules and the main candidate antigens are also discussed.

Lessons from studies of antigen-specific T cell responses in Multiple Sclerosis

Multiple Sclerosis (MS) is considered a T cell-mediated autoimmune disease of central nervous system myelin. Based on elegant experiments in an animal model of MS, experimental allergic encephalomyelitis (EAE), a number of myelin proteins and peptides derived from these can induce inflammatory demyelinating lesions. Recent studies with transgenic mice expressing human HLA-DR molecules and a myelin basic protein (MBP)-specific T cell receptor as well as data from a phase II clinical trial with an altered peptide ligand based on MBP peptide (83-99) provide convincing evidence that the pathogenetic concepts which largely stem from the above EAE studies are valid in MS, too.

Association of apolipoprotein E polymorphism to clinical heterogeneity of multiple sclerosis

In this study we investigated the distribution of apolipoprotein E (APO E) genotypes in sporadic multiple sclerosis (MS) cases and in normal controls. Later onset of chronic progressive MS was observed in patients carrying the epsilon2 allele, whereas APO E alleles were found at similar frequency in MS and in the control population. These findings indicate that clinical heterogeneity, but probably not susceptibility to the disease, is associated to APO E genotypes.

Mechanisms of immunomodulation by glatiramer acetate

OBJECTIVE

To define the mechanism of action of glatiramer acetate (GA; formerly known as copolymer-1) as an immunomodulatory treatment for MS.

BACKGROUND

The proposed mechanisms of action of GA include 1) functional inhibition of myelin-reactive T cells by human leukocyte antigen (HLA) blocking, 2) T-cell receptor (TCR) antagonism, and 3) induction of T helper 2 (Th2) immunomodulatory cells. In this report, the authors examined the effects of GA on the functional activation of human T-cell clones (TCC) specific for myelin basic protein (MBP) and for foreign antigens. Several questions were addressed: Is the inhibitory effect of GA specific for autoantigens? Is it mediated by blocking the interaction between peptide and HLA molecule? Is GA a partial agonist or TCR antagonist, or does it induce anergy? Does it induce Th2 modulatory T cells?

METHODS

The effects of GA on antigen-induced activation of human TCC specific for MBP, influenza virus hemagglutinin, and Borrelia burgdorferi were studied by proliferation and cytokine measurements, TCR downmodulation, and anergy assays. GA-specific TCC were generated in vitro from the peripheral blood of patients and healthy controls by limiting dilution.

RESULTS

GA more strongly inhibited the proliferation of MBP, as compared with foreign antigen-specific TCC; in some MBP-specific TCC, the production of Th1-type cytokines was preferentially inhibited. In addition to HLA competition, the induction of anergy, but not direct TCR antagonism, was observed. Numerous GA-specific TCC were generated from the peripheral blood of both MS patients and normal controls, and a fraction of these showed a Th2 phenotype.

CONCLUSIONS

This study confirms a preferential inhibitory effect of GA on autoreactive TCC. With respect to cellular mechanisms, although HLA competition appears to play the most important role in functional inhibition in vitro, a direct effect on the TCR may be involved at least in some autoreactive T cells as shown by anergy induction. Although not confirmed at the clonal level, it is demonstrated further that GA induces T cells that crossreact with myelin proteins. GA-specific, Th2-modulatory cells may play an important role in mediating the effect of the drug in vivo.

Encephalitogenic potential of the myelin basic protein peptide (amino acids 83-99) in multiple sclerosis: results of a phase II clinical trial with an altered peptide ligand

Myelin-specific T lymphocytes are considered essential in the pathogenesis of multiple sclerosis. The myelin basic protein peptide (a.a. 83-99) represents one candidate antigen; therefore, it was chosen to design an altered peptide ligand, CGP77116, for specific immunotherapy of multiple sclerosis. A magnetic resonance imaging-controlled phase II clinical trial with this altered peptide ligand documented that it was poorly tolerated at the dose tested, and the trial had therefore to be halted. Improvement or worsening of clinical or magnetic resonance imaging parameters could not be demonstrated in this small group of individuals because of the short treatment duration. Three patients developed exacerbations of multiple sclerosis, and in two this could be linked to altered peptide ligand treatment by immunological studies demonstrating the encephalitogenic potential of the myelin basic protein peptide (a.a. 83-99) in a subgroup of patients. These data raise important considerations for the use of specific immunotherapies in general.

Minimal peptide length requirements for CD4(+) T cell clones--implications for molecular mimicry and T cell survival

CD4(+) T lymphocytes usually recognize peptides of 12-16 amino acids in the context of HLA class II molecules. We have recently used synthetic peptide combinatorial libraries to dissect in detail antigen recognition by autoreactive CD4(+) T cell clones (TCC). The results of these studies demonstrated that antigen recognition by T cells is highly degenerate and that many cross-reactive ligands can be defined, some of which much more potent than the selecting autoantigen. Based on these observations, we examined the response of a myelin basic protein-specific HLA class II-restricted CD4(+) TCC to truncation variants of optimal ligands. Surprisingly, pentapeptides, tetrapeptides and even tripeptides derived from different segments of the optimal ligands were recognized by the TCC, and some were even more potent than the selecting autoantigen. In addition, these peptides enhanced the survival of the TCC at low concentration. The relevance of this finding was supported by the generation of pentapeptide-specific CD4(+) TCC from peripheral blood lymphocytes. These observations not only change existing views on the length requirements for activation of CD4(+) HLA class II-restricted T cells, but also extend our knowledge about the flexibility of TCR recognition and the potential for cross-reactivity in the immune system.

Contribution of individual amino acids within MHC molecule or antigenic peptide to TCR ligand potency

The TCR recognition of peptides bound to MHC class II molecules is highly flexible in some T cells. Although progress has been made in understanding the interactions within the trimolecular complex, to what extent the individual components and their amino acid composition contribute to ligand recognition by individual T cells is not completely understood. We investigated how single amino acid residues influence Ag recognition of T cells by combining several experimental approaches. We defined TCR motifs for CD4+ T cells using peptide synthetic combinatorial libraries in the positional scanning format (PS-SCL) and single amino acid-modified peptide analogues. The similarity of the TCR motifs defined by both methods and the identification of stimulatory antigenic peptides by the PS-SCL approach argue for a contribution of each amino acid residue to the overall potency of the antigenic peptide ligand. In some instances, however, motifs are formed by adjacent amino acids, and their combined influence is superimposed on the overall contribution of each amino acid within the peptide epitope. In contrast to the flexibility of the TCR to interact with different peptides, recognition was very sensitive toward modifications of the MHC-restriction element. Exchanges of just one amino acid of the MHC molecule drastically reduced the number of peptides recognized. The results indicate that a specific MHC molecule not only selects certain peptides, but also is crucial for setting an affinity threshold for TCR recognition, which determines the flexibility in peptide recognition for a given TCR.

Dipeptidyl peptidase IV (CD26): role in T cell activation and autoimmune disease

The ectoenzyme dipeptidyl peptidase IV (DP IV; EC 3.4.14.5; CD26) has been shown to play a crucial role in T cell activation. In the present study, we show by flow cytometry and by enzymatic DP IV assay that myelin basic protein (MBP)-specific, CD4+ T cell clones (TCC) derived from patients with multiple sclerosis (MS) express high levels of DP IV/CD26. The enzymatic activity of resting TCC was found to be three to fourfold higher than on resting peripheral blood T cells and close to that of T cells 48 hours after PHA stimulation. The DP IV inhibitors Lys[Z(NO2)]-thiazolidide and Lys[Z(NO2)]-pyrrolidide suppress in a dose-dependent manner DNA synthesis and IFN-gamma, IL-4, and TNF-alpha production of the antigen-stimulated TCC. These data suggest that CD26 plays a role in regulating activation of autoreactive TCC. Further in vivo investigations will clarify, whether the inhibition of the enzymatic activity of DP IV could be a useful tool for therapeutic interventions in MS and/or other autoimmune diseases.

Identification of candidate T-cell epitopes and molecular mimics in chronic Lyme disease

Elucidating the cellular immune response to infectious agents is a prerequisite for understanding disease pathogenesis and designing effective vaccines. In the identification of microbial T-cell epitopes, the availability of purified or recombinant bacterial proteins has been a chief limiting factor. In chronic infectious diseases such as Lyme disease, immune-mediated damage may add to the effects of direct infection by means of molecular mimicry to tissue autoantigens. Here, we describe a new method to effectively identify both microbial epitopes and candidate autoantigens. The approach combines data acquisition by positional scanning peptide combinatorial libraries and biometric data analysis by generation of scoring matrices. In a patient with chronic neuroborreliosis, we show that this strategy leads to the identification of potentially relevant T-cell targets derived from both Borrelia burgdorferi and the host. We also found that the antigen specificity of a single T-cell clone can be degenerate and yet the clone can preferentially recognize different peptides derived from the same organism, thus demonstrating that flexibility in T-cell recognition does not preclude specificity. This approach has potential applications in the identification of ligands in infectious diseases, tumors and autoimmune diseases.

Molecular mimicry and multiple sclerosis--a possible role for degenerate T cell recognition in the induction of autoimmune responses

Multiple sclerosis is an inflammatory demyelinating disease of the central nervous system. The etiology is unknown, but several lines of evidence support the hypothesis that the pathogenesis is mediated by autoreactive T lymphocytes. Molecular mimicry has been proposed as a possible mechanism for the development of an autoimmune response to myelin antigens. According to this model, an immune reaction to self antigens could be initiated by T cells that cross-react with infectious agents that "mimic" the autoantigen, i.e. they share immunologic epitopes. It was previously thought that, in order for a cross-reaction of T cells to two different antigens to occur, a substantial amino acid sequence homology between the two antigens was required. More recent studies on the basic mechanisms of T cell antigen recognition have shown that, at least for some T cell clones, antigen recognition is more "degenerate" and sequence homology is not required for crossreactivity to occur. This article reviews the relevance of these recent advances in basic T cell receptor immunology to the occurrence of autoimmunity in the central nervous system.

Molecular mimicry and multiple sclerosis: degenerate T-cell recognition and the induction of autoimmunity

Various mechanisms have been proposed for the initiation of autoimmune responses by autoreactive T-cell clones. One of these, the molecular mimicry hypothesis, postulates that myelin-reactive T-cell clones are activated by foreign antigens. Until recently, sequence homology between self- and foreign antigens was considered necessary for cross-recognition to occur in multiple sclerosis. This article reviews current progress in T-cell receptor immunology that led to modify this view and proposes a role for degenerate T-cell antigen recognition in the induction of autoimmunity.

Exploring immunological specificity using synthetic peptide combinatorial libraries

The definition of epitopes for human B and T cells is fundamental for the understanding of the immune response mechanism and its role in the prevention and cause of human disease. This understanding can be applied to the design of diagnostics and synthetic vaccines. In recent years, the understanding of the specificity of B and T cells has been advanced significantly by the development and use of combinatorial libraries made up of thousands to millions of synthetic peptides. The use of this approach has had four major effects: first, the definition of high affinity ligands both for T cells and antibodies; second, the application of alternative means for identifying immunologically relevant peptides for use as potential preventive and therapeutic vaccines; third, a new appreciation of the requirements for TCR interactions with peptide-MHC complexes in immunogenicity; fourth, the establishment of new principles regarding the level of cross-reactivity in immunological recognition.

Inhibitors of dipeptidyl peptidase IV/CD26 suppress activation of human MBP-specific CD4+ T cell clones

The ectoenzyme dipeptidyl peptidase IV (DP IV, EC 3.4.14.5, CD26) has been shown to play a crucial role in T cell activation. Specific inhibitors of DP IV suppress DNA synthesis as well as cytokine production (IL-2, IL-10, IL-12, IFN-gamma) of stimulated human and mouse T cells suggesting a potential application of these effectors in transplantations and autoimmune diseases. In the present study, we have examined the expression of DP IV/CD26 on six myelin basic protein (MBP)(87-99)-specific, CD4+ T cell clones (TCC) derived from patients with multiple sclerosis (MS) as well as the biological effects of the two synthetic DP IV inhibitors Lys[Z(NO2)]-thiazolidide and Lys[Z(NO2)]-pyrrolidide on the function of these cells. All TCC expressed high levels of DP IV/CD26, as shown by flow cytometry and by enzymatic DP IV assay. Enzymatic activity of resting TCC was found to be three to fourfold higher than on resting peripheral blood T cells and close to that of T cells 48 h after PHA stimulation. The DP IV inhibitors suppress DNA synthesis and IFN-gamma, IL-4, and TNF-alpha production of the antigen-stimulated TCC. These data suggest that CD26 plays a role in regulation of activation of autoreactive TCC. Further in-vivo investigations, first in experimental models, will clarify, whether the inhibition of the enzymatic activity of DP IV could be a useful tool for therapeutic interventions in MS or other autoimmune diseases.

Detection of skewed T-cell receptor V-beta gene usage in the peripheral blood of patients with multiple sclerosis

The ex vivo analysis of the T-cell receptor V-beta (TCRBV) gene usage by circulating T lymphocytes in Multiple Sclerosis (MS) patients may contribute to understanding disease pathogenesis. In the present study, TCRBV gene usage was analyzed in freshly collected unstimulated peripheral blood mononuclear cells (PBMC) isolated from 40 MS patients and 20 healthy controls. Nine patients presented abnormal repertoires, with expansion of one or more TCRBV segments. Among these patients, six presented expansion of TCRBV9 chain expression, three also having an expansion of TCRBV1, TCRBV11 and TCRBV22 segments. The most frequently observed TCRBV chain expansion, TCRBV9, was further analyzed and identified as polyclonal. Evaluation of clinical variables showed that median disease duration was shorter in patients with TCRBV gene expression abnormalities. Longitudinal evaluation of five patients with a skewed repertoire showed regression of expanded TCRBV chains expression to normal values. These data indicate that certain MS patients have abnormal TCRBV gene expression. Such abnormalities are caused by polyclonal expansions of T lymphocyte subpopulations that use the same TCRBV gene families, are unstable and preferentially observed early in the course of the disease.

Predictable TCR antigen recognition based on peptide scans leads to the identification of agonist ligands with no sequence homology

The potential of CD4+ T cells for cross-recognition of self and foreign Ags has important implications for the understanding of thymic selection, lymphocyte survival, and the occurrence of autoimmune diseases. Here, we define the extensive flexibility of Ag recognition for three human CD4+ autoreactive T cell clones (TCC) by using ligands with single and multiple amino acid (aa) substitutions. Our results demonstrate that the spectrum of tolerated ligands and the resulting stimulatory potency of peptides for a TCC can be predicted by the relative influence of each aa. Using this approach, we have identified stimulatory ligands not sharing a single aa in corresponding positions with the Ag used to establish the TCC. These results argue for an independent contribution of each aa in the peptide sequence to the affinity of the MHC/peptide complex to the TCR.

Immunosuppressive activity of 13-cis-retinoic acid in rats: aspects of pharmacokinetics and pharmacodynamics

Pharmacokinetics and pharmacodynamics of 13-cis-retinoic acid (13-cRA) administered at doses that suppress experimental autoimmune encephalomyelitis (EAE) have been investigated in rats. Serum concentration of the drug measured following oral administration of 37 mg/kg/12 h reached a peak of 1.8 x 10(-5) M in 2 h and linearly declined to 7.8 x 10(-7) M at hour 12. When spleen cells (SC) collected from 13-cRA-administered animals were cultured in vitro, their proliferative response to the T-cell mitogen concanavalin A (ConA) was suppressed and this effect was dependent on in vivo serum concentrations of the drug. In addition, in vitro exposure of antigen-specific T-cell lines to 13-cRA concentrations equivalent to those observed in vivo caused a dose-dependent suppression of the proliferation induced by the antigen as well as by T-cell mitogens. On a molar basis, 13-cRA showed a stronger in vitro immunosuppressive activity than two immunosuppressive agents used in human therapy, cyclosporin A and 6-mercaptopurin.

Major differences in cardiovascular risk indicators by educational status. Results from a population based screening program

All people aged 30-59 years living in one primary health care center's catchment area were invited to participate in a population based screening program. A total of 2642 people (68%) participated. An overall risk index for having a heart attack within 5 years (Ps) was calculated based on diastolic BP, smoking status, total cholesterol, and age. Other risk indicators registered were Body Mass Index, and physical activity. A highly significant association between education level and age-adjusted overall risk index for both men (p = 0.001) and women (p < 0.001) was found. Also Body Mass Index, total cholesterol, smoking status, and, for women, diastolic blood pressure showed similar significant variation with education level with higher education associated to lower risk. These findings imply the possibility of a great variation in the "risk" of receiving pharmacological treatment for one's CVD risk factors.

Transforming growth factor-beta 1 inhibits the proliferation of rat astrocytes induced by serum and growth factors

A number of cytokines and growth factors may affect astrocyte proliferation and functions. Transforming growth factor-beta 1 (TGF-beta 1) is a pleiotropic cytokine which exerts multiple effects on growth and differentiation of different cell types. TGF-beta 1 is present in low amounts in the normal brain. TGF-beta 1 gene expression, however, is increased in the central nervous system (CNS) in several pathological conditions. In this study we examined the in vitro effects of TGF-beta 1 on the proliferative response of rat astrocytes to serum and growth factors. Astrocyte cultures were established from the cerebellum and cortex of newborn Lewis rats. The proliferative response of these cultures to serum and growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), insulin-like growth factor 1 (IGF-1), IGF-2, interleukin 1 (IL-1)] was studied by [3H]-thymidine incorporation test in the presence or absence of TGF-beta 1. TGF-beta 1 significantly inhibited the proliferative response of astrocyte cultures to both autologous and heterologous serum. In addition, a strong inhibition of bFGF-, EGF-, and PDGF-induced proliferation was observed. The effect of TGF-beta 1 on the proliferative response to IL-1 was less evident but still significant. No effect was observed when TGF-beta 1 was added to IGF-1 and IGF-2 stimulated cultures. These data confirm previous reports showing a down-regulating activity of TGF-beta on astrocyte proliferation and suggest that this cytokine may play physiological and pharmacological roles in the regulation of reactive astrocytosis in the CNS.

Population based CVD health risk appraisal. A method to create a "critical mass" of health-conscious people

This study used a population based screening procedure as a means for a combined strategy for targeting individuals at high risk of cardiovascular disease while aiming for a low-risk population. During a five month period 68% of the total target population (2642 out of 3880) men and women attended the screening. We found, 1) that a broad population based health risk appraisal activity, supported by a personal computer as an educational tool and as a means to speed up the handling of each test, was feasible, 2) that it was easy to identify high risk individuals, to be able to offer them further follow-up, and 3) that there is evidence supporting the view that reaching a large proportion of the population in a limited time period, a "critical mass", will contribute to a growing health awareness not only among participants but also among the general population in the actual area.

Hemispheric asymmetry for the auditory recognition of true and false statements

A group of right-handed adult subjects (24 males and 24 females) were asked to judge phrases as to their truthfulness of falsehood, by listening to them via earphones either with the right or with the left ear. These phrases, which had been previously recorded by two non-actors (1 male and 1 female) and two actors (1 male and 1 female), were either true or false. The number of correct judgements made by the subjects was significantly higher than the number of wrong judgements. The subjects correctly recognised significantly more true phrases than false ones. Moreover, they better recognised true phrases pronounced by the actors and false phrases pronounced by the non-actors. True phrases pronounced by male speakers and false phrases pronounced by female speakers were better recognised. A left-ear advantage was found in the recognition of true statements.

Non-pharmacological methods reduce drug use in the treatment of hypertension. A two-year trial in general practice

In a primary-care based study, 122 patients who were taking antihypertensive drugs took part in a two-year trial that aimed at establishing the feasibility of non-pharmacological methods in the treatment of hypertension in general practice. The patients could choose from among 14 non-pharmacological methods of blood pressure reduction. Increased physical exercise; weight reduction, low-sodium and low-fat diet, relaxation training, and home-monitoring of blood pressure were the most popular methods. The use of anti-hypertensive drugs was reduced by 55% in the participants, with the defined daily dose (DDD) being lowered from 1.18 to 0.55 (P less than 0.001). At the end of the study, 46% of the participants were free from anti-hypertensive drugs. Significant reductions occurred in body mass index (27.1 to 26.4 kg/m2, P = 0.001) and serum cholesterol (6.89 to 6.48 mmol/l, P less than 0.001). According to some measures used, the study group's experience of "quality of life" was not reduced.