Biochemical analysis of plasma-soluble invariant chains and their complex formation with soluble HLA-DR

The invariant chain (CD74) is preferentially localized in the cytoplasm and regulates the loading of exogenous derived peptides into HLA class II heterodimers. In addition, a small proportion of CD74:class II complexes is also expressed on the cell surface. We identified and quantified soluble CD74 (sCD74) molecules in the plasma and sCD74:sHLA-DR complexes by ELISA. EDTA plasma samples from 86 healthy probands were analyzed. sCD74 could be detected in all samples with a mean concentration of 1.14 relative units±1.04 SD (range 0.17-4.31). Approximately 10% of the samples had increased amounts of sCD74 (3.0 relative units). Complexes of sCD74 and sHLA-DR were detected in all samples and their quantities were positively correlated (r=0.83, p0.001) with the sCD74 concentrations. SDS-PAGE analysis of plasma samples with high sCD74 concentrations (3.0 relative units) revealed four isoforms of sCD74 with molecular weights of 45, 43, 35, 31 kDa corresponding to known sizes of intracellular CD74. However, only molecular weights of the 45 and 43 kDa isoforms of sCD74 are found complexed with sHLA-DR. Our data demonstrate, that CD74 molecules are present in their soluble form in the plasma of healthy probands and form complexes with soluble HLA-DR molecules.     

卡氏肺孢子虫的超微结构观察

采用皮下注射醋酸可的松和低蛋白饲养方法诱发SD大鼠自然感染卡氏肺孢子虫后,取其肺组织,按常规方法进行透射电镜的系统观察。结果除为Yoshida提出的卡氏肺孢子虫生活史的有性增殖和无性增殖循环的最新设想提供了某些形态学依据外,还继Vossen等之后再次发现该病原在1型肺泡上皮细胞内寄生的情况。本文最后就卡氏肺孢子虫对宿主的致病机理进行了讨论。     

Moclobemide and specific serotonin re-uptake inhibitor combination treatment of resistant anxiety and depressive disorders

This retrospective study was undertaken with the objective of determining how effective and safe moclobemide, a specific and reversible inhibitor of monoamine oxidase-A (RIMA), is when used in combination with specific serotonin re-uptake inhibitors (SSRIs), in a clinical setting. A thorough chart review was done of all patients with affective and anxiety disorders seen at our centre who received combination treatment with moclobemide and an SSRI. Combination moclobemide-SSRI treatment demonstrated good efficacy in treating treatment-resistant patients. The combination treatment was well tolerated with very few drug interactions. Dosages should be started low, titrated slowly and carefully, and patients should be monitored closely.     

Segregation analysis of diastolic blood pressure in a large pedigree

Hypertension, a major risk factor for cardiovascular diseases, is thought to be inherited to some extent. However, the nature of its genetic component remains unresolved. In the present study, data from a single large kindred (the HGAR1 pedigree) were used to search for evidence of single gene and multifactorial effects on diastolic blood pressure. Commingling analyses found that a mixture of three distributions fit the data significantly better than a single normal distribution, suggesting a major effect influencing diastolic blood pressure levels. However, segregation analysis, using regressive models, indicated that the transmission probabilities were not consistent with Mendelian expectations. There was no evidence of either major gene or polygenic effects on diastolic blood pressure levels in this family. © 1993 Wiley-Liss, Inc.     

Interactions between membrane IgM and the cytoskeleton involve the cytoplasmic domain of the immunoglobulin receptor

Cross-linking induced interactions between the membrane form of immunoglobulin (mIg) and the cytoskeletal matrix have been described by several groups. To date, the function of mIgM association with the cytoskeleton is not yet understood. Delineation of the molecular basis of these interactions will be instrumental in elucidating their function. We have previously shown that the Igα/β heterodimer is not required for ligand-induced mIgM binding to the cytoskeleton. In this study, we have investigated the role of other B cell-specific proteins in mediating these interactions. For this, we expressed mIgM in the non-hematopoietic human cervical carcinoma cell line HeLa S3 and verified the capacity of the surface-expressed IgM to interact with the cytoskeletal matrix upon cross-linking with anti-μ chain antibodies. We show here that only the mIgM molecule itself and no other B cell-specific protein(s) is required in mediating mIgM interactions with actin filaments. In an attempt to determine the cytoskeleton-binding site of mIgM we investigated the role of the cytoplasmic tail of mIgM (KVK) in binding the receptor to actin-based microfilaments. Using mutated forms of mIgM expressed in J558L cells, we show here that KVK plays a role in mediating these interactions. The absence of KVK did not, however, completely abrogate mIgM-cytoskeletal interactions, suggesting that there are additional molecular requirements for the ligand-induced mIgM binding to the cytoskeletal matrix.     

Anterior lumbar instrumentation improves correction of severe lumbar Lenke C curves in double major idiopathic scoliosis

Fifteen skeletally immature patients with double major adolescent idiopathic scoliosis with large lumbar curves and notable L4 and L5 coronal plane obliquity were retrospectively studied. Seven patients who underwent anterior release and fusion of the lumbar curve with segmental anterior instrumentation and subsequent posterior instrumentation ending at L3 were compared with eight patients treated with anterior release and fusion without anterior instrumentation followed by posterior instrumentation to L3 or L4. At 4.5 years follow-up (range 2.5-7 years), curve correction, coronal balance and fusion rate were not statistically different between the two groups; however, the group with anterior instrumentation had improved coronal plane, near normalangulation in the distal unfused segment compared with the group without anterior instrumentation. In cases involving severe lumbar curvatures in the context of double major scoliosis, when as a first stage anterior release is chosen, the addition of instrumentation appears to restore normal coronal alignment of the distal unfused lumbar segment, and may in certain cases save a level compared with traditional fusions to L4.     

The organization of trigeminotectal and trigeminothalamic neurons in rodents: a double-labeling study with fluorescent dyes

Retrogradely transported fluorescent dyes (fast blue and diamidino-dihydrochloride yellow) were used to compare the distributions of trigeminofugal neurons that project to the superior colliculus and/or the thalamus in three rodent species. The objective was to determine what the projection and collateralization patterns of these trigeminofugal pathways are and whether they are similar among different species. In each anesthetized animal, one dye was injected into the superior colliculus and the other into the topographically congruent area of the thalamus. Counts of the numbers of yellow, blue, and double-labeled neurons were made throughout the trigeminal complex: principalis, pars oralis, pars interpolaris, and pars caudalis. Trigeminothalamic projections were similar in each of the rodent species studied. The densest concentration of retrogradely labeled neurons was in principalis, with substantially fewer neurons in pars interpolaris, and fewer still in pars oralis and pars caudalis. These neurons were generally small and tended to have round or fusiform somata. A common pattern was also noted among the three species for trigeminotectal neurons. Most trigeminotectal projections originated from neurons in pars interpolaris, somewhat fewer from pars oralis, and the fewest from principalis and pars caudalis. These neurons tended to be the largest in each subdivision and were often multipolar. Following paired injections of the tracers, double-labeled neurons were scattered throughout the sensory trigeminal complex and had morphologies characteristic of single-labeled trigeminotectal neurons. Although comparatively few double-labeled neurons were observed in any species, most of those seen were restricted to the ventrolateral portion of pars interpolaris, a position that corresponds to the representation of the vibrissae. These data indicate that, regardless of the rodent species, the vast majority of labeled trigeminal neurons project either to the superior colliculus or the thalamus, but not to both targets. This might be expected on the basis of the very different behavioral roles these structures play. On the other hand, a subpopulation of trigeminal neurons exists (mainly in pars interpolaris) that does project to both the superior colliculus and the thalamus, perhaps because both structures require some of the same somatosensory information to perform their behavioral functions.     

Serum glomerular binding activity is highly correlated with renal disease in MRL/lpr mice.

The pathogenesis of lupus nephritis is felt to be mediated by anti-DNA antibodies. However, the anti-DNA response and renal disease do not entirely correspond. We recently developed a new assay which detects immune elements based on their ability to bind glomeruli as an alternative approach to understanding the pathogenesis of this disorder. The glomerular binding activity (GBA) defined by this assay consists of immune elements containing IgG which interact specifically with renal tissue, the binding of which is DNase-inhibitable, but which do not bind to DNA directly. In the current study we assessed the relationship between GBA and renal disease in MRL/lpr mice (both untreated and cyclophosphamide-treated) and compared it with the anti-DNA assay. Both assays were highly correlated with renal disease in untreated mice in terms of proteinuria. In cyclophosphamide-treated mice, however, only a weak correlation between the anti-DNA assay and proteinuria was apparent. GBA, in contrast, was more strongly correlated with proteinuria in treated mice. This correlation improved substantially when the DNase-sensitive component of the GBA was used. GBA appeared related to, but not covariant with, the anti-DNA response. These results demonstrate that GBA is a better correlate of murine lupus nephritis than the anti-DNA assay, and suggest that the immune elements detected by this assay, the DNase-sensitive component in particular, may be pathogenically important.     

Ia-expressing microglial cells in experimental allergic encephalomyelitis in rats

Summary Monoclonal antibodies (MRC OX-6 and OX-17) recognized three types of cells expressing Ia antigen during the course of acute experimental allergic encephalomyelitis (EAE) in rats. In earlier stages of the disease, in animals with or without paralysis, Ia antigens were mostly localized to subarachnoidal and perivascular lymphocytic and histiocytic cell infiltrates, possibly serving as antigen-presenting cells. On the other hand, in convalescent rats, Ia antigens were expressed in a large number of cells with dendritic processes heavily populating the spinal gray matter. The appearance of these Ia-expressing cells in the convalescent stage coincided with the development of degenerating axon terminals in the spinal gray matter. These Ia-expressing cells possessed morphological features characteristic of microglia and were positive for ML-1 lectin but did not express glial fibrillary acidic protein. Immune electron microscopy disclosed the presence of Ia reaction products in the Golgi apparatus, endoplasmic reticulum and plasma membrane of these cells with dendritic processes, indicating active synthesis of Ia molecules in microglia. In addition, Ia antigens were localized to the cells with ultrastructural features of macrophages. Thus, Ia-expressing cells in EAE seems to play dual roles: the induction of immunological reactions during earlier stages and the participation in reparative processes during convalescence.Supported by Grants-in-aid from the Ministry of Health and Welfare for Intractable Neuroimmunological Diseases and from the Ministry of Education, Science and Culture (Project 61570380 to HK)     

"Necklace olfactory glomeruli" form unique components of the rat primary olfactory system

A distinct subset of rat primary olfactory neurons was identified immunohistochemically by means of a polyclonal antibody against human placental antigen X-P2 (hPAX-P2), an incompletely characterized substance found in all estrogen-biosynthetic organs. The subset of olfactory receptor cells was distributed widely over the olfactory epithelium with some degree of concentration on the dorsocaudal walls of nasal subcavities. The subset formed unique "necklace olfactory glomeruli," which were composed of seven to nine solitary glomeruli located in the caudal end of the olfactory bulb. One of them was located in the "modified glomerular complex" reported to be involved in rat suckling behavior. The projectional patterns of the necklace olfactory system, albeit diffuse, indicated some degree of spatial correspondence between zones of olfactory epithelium and specific glomeruli. Axons emanating from neighboring cells can project to several glomerular loci. From the necklace olfactory system, an average of 150-200 receptor cells were estimated to converge onto a single necklace glomerulus.