Nationwide collaborative study of HLA class II associations with distinct types of juvenile chronic arthritis (JCA) in Greece

The aim of this study was to investigate the association of different groups and subgroups of juvenile chronic arthritis (JCA) with HLA class II (DR, DP, DQ) alleles and/or haplotypes. Groups and subgroups were mainly distinguished on the basis of the type of onset, the course and complications of the disease, and some predefined disease markers according to the criteria proposed by the ILAR Standing Committee (Chile, 1994). On the basis of these criteria the following five JCA groups and their subgroups were included in the study: (1) definite systemic onset (n = 25) and systemic progressing to persistent arthritis (n = 14); (2) JCA of oligoarthritis onset (O-JCA, n = 124) and of oligoarthritis onset and course (n = 98), O-JCA of early (< 6 years) or late (> 6 years) onset (EOO-JCA n = 71 and LOO-JCA n = 44), O-JCA with ANA positive (n = 69) or negative (n = 55) and O-JCA progressing to extended arthritis (n = 22); (3) JCA of polyarthritis onset (P-JCA) with rheumatic factor (RF) negative (n = 29), and P-JCA RF negative with antinuclear antibodies (ANA) positive (n = 13) or negative (n = 16); (4) JCA complicated with chronic anterior uveitis (CAU, n = 32); (5) juvenile psoriatic arthritis (n = 20). To assess the HLA allele frequencies in the above 223 Greek children with JCA, these frequencies were compared to those of 98 age-matched and 250 adult controls. The main findings were the following. A common HLA-DRB1* allele was not involved in the JCA groups and subgroups studied; on the other hand, the DQA1*0501 allele was found to be associated with different JCA groups/subgroups (O-JCA, P-JCA RF-negative ANA-positive, JCA with CAU), probably suggesting a closer relationship of this locus with the immunogenetic background of JCA. The DPB1*0201 allele was associated with the development of either EOO-JCA or CAU. Susceptibility to CAU was stronger when the DPB1*0201 was combined with the presence of DRB1*13. Another allele, DQB1*0301, was also associated with O-JCA and CAU. Finally, no specific HLA class II allele was found to be related to the presence of ANA or psoriatic lesions or to the severity of the arthritis. Our findings suggest that the wide clinical and laboratory spectrum of JCA is associated with an immunogenetic background that is linked with HLA alleles of more than one locus. Some of them, such as the DPB1*0201 allele, confer susceptibility to certain clinical onsets and courses or complications of the disease. The rapidly advancing techniques of typing of DNA profiles may lead to more definite conclusions.     

Effects of protein kinase C activators on phorbol ester-sensitive and - resistant EL4 thymoma cells

Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12- myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester- resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.      

Perinatal stimulation and adaptation of the neonate

The present report describes psychobiological studies of behavior around the time of birth. An adaptive, ecological perspective is presented in which stimulation of the fetus and newborn is purported to instigate adaptive postpartum behavior. Studies describing the perinatal sensory environment are reviewed, with a consideration of emergent sensory function of the fetus. It is asserted that afferent input associated with parturition perturbs the fetus and neonate, producing a general arousal state that facilitates breathing, suckling, and early learning. The view developed herein is that perinatal sensory input induces and canalizes the newborn's behavior, thereby regulating adaptive postpartum function. Deviations in afferent input may alter ontogenetic trajectories and compromise developmental outcome by reducing availability of conditions necessary for adequate postpartum adaptation.     

Prekallikrein-Kallikrein conversion rate as a predictor of contrast material catastrophies

An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%.