Signaling through CD40 rescues IgE but not IgG or IgA secretion in X-linked immunodeficiency with hyper-IgM

The ligand for CD40 (CD40L) is a membrane protein on activated T cells that induces B cell proliferation and differentiation. Several mutations of the CD40L gene were reported responsible for defective class switching of B cells in an X-linked immunodeficiency with hyper IgM (X-HIM). We studied four affected males from three families and found three independent mutations including new mutations of CD40L gene. In every X-HIM patient tested, however, anti-CD40 plus IL-10 did not induce class switching from IgM to IgG or IgA, even in the presence of Staphylococcus aureus Cowan I strain (SAC). CD4+ T cell clones, expressing CD40L on their surface, also did not rescue IgG or IgA induction by X-HIM peripheral blood B cells in vitro. But signaling through CD40 induced both B cell proliferation and IgE secretion when IL-4 was added to the culture. Taken together, these results show that in vitro signaling through CD40 rescues IgE but not IgG or IgA secretion by peripheral blood X-HIM B cells and suggest that in vivo CD40 and CD40L interaction might be necessary for IgG and IgA differentiation in X-HIM.

Functional chicken gizzard heavy meromyosin expression in and purification from baculovirus-infected insect cells

The heavy chain and the essential and the regulatory light chains of chicken gizzard heavy meromyosin (HMM) were coexpressed in Spodoptera frugiperda (fall armyworm) cells infected with a mixture of two recombinant Autographa californica baculoviruses. Soluble HMM consisting of the heavy chain and the two types of light chains was obtained. The recombinant HMM was purified from the virus-infected cells and characterized. The regulatory light chain of the isolated recombinant HMM was phosphorylated by myosin light chain kinase in the presence of calmodulin in a Ca(2+)-dependent manner. The ATPase of the recombinant HMM was activated by rabbit skeletal muscle actin when myosin light chain kinase, calmodulin, and Ca2+ were present in the reaction medium. Chicken gizzard tropomyosin enhanced the actin-activated ATPase activity. The recombinant HMM decorated actin filaments, displaying the characteristic arrowhead pattern along the filaments. This report on a functional recombinant double-headed smooth muscle myosin fragment opens the way to detailed studies on the molecule.

Angiotensin-converting enzyme polymorphism and development of diabetic nephropathy in non-insulin-dependent diabetes mellitus

We determined the distribution frequency of angiotensin-converting enzyme insertion/deletion (I/D) polymorphism in 111 Japanese patients with non-insulin-dependent diabetes mellitus (NIDDM) of at least 10 years duration (80 patients with diabetic nephropathy and 31 patients without nephropathy) and 76 healthy Japanese controls. Patients with diabetic nephropathy showed an excess of the ID genotype compared with patients without nephropathy (p < 0.02) and less of the II genotype compared with healthy controls (p < 0.01) and patients without nephropathy (p < 0.01). NIDDM patients with the II genotype have a decreased risk for the development of diabetic nephropathy.

Adult idiopathic chondrolysis of the hip--report of two cases

Idiopathic chondrolysis of the hip is characterized by pain, limping and a progressive restriction in the range of motion of the hip. The paper describes the case of two female patients, age 28 and 37, who were referred to our hospital in October 1985 and May 1991 for pain and limitation of movement in the right hip. Neither patient had a previous history of systemic illness or trauma or medication such as steroids. On admission they underwent clinical and X-ray examinations. Both required an open biopsy to confirm the diagnosis. They have been followed for 4 years and 8 years, respectively.

Supersensitization of neurochemical responses by L-DOPA and dopamine receptor agonists in the striatum of experimental Parkinson's disease model rats

We studied the mechanisms of dopamine receptor agonist- and L-DOPA-mediated supersensitization in experimental Parkinson's disease model rats, by measuring in vivo acetylcholine (ACh) release, GTPase activities, and mRNA expression in the striatum of 6-hydroxydopamine-treated rats. D1 agonist (SKF38393) and D2/D3 agonists (bromocriptine and quinpirole) showed more potent stimulation or inhibitions on ACh release in the model rat than in the control. However, quinpirole-evoked stimulation of GTPase activity was enhance in the model rats, compared to the control, while there was no significant enhancement of the bromocriptine-evoked stimulation. On the other hand, L-DOPA at 0.3-10 pM showed a biphasic action including significant inhibition on the GTPase activity in the lesioned striatal membranes, but not in the control. In the RNAase protection assay, neither D1, D2, Gi1 alpha, GoA alpha nor Gs alpha mRNA expression in the model was significantly different from the control. These findings suggest that there is supersensitization of D1 and D2/D3 receptors in the experimental Parkinson's disease model, while the upregulation of their receptors or GTP-binding proteins (G-proteins) to be coupled to their receptors is unlikely involved in major parts of such mechanisms. In addition, the present report provides the first evidence that L-DOPA mediates neurochemical responses in the plasma membranes, possibly through its receptor.

[Characterization of infiltrating mononuclear cells in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis (EAE)]

Mononuclear cells (MNCs) infiltrating in spinal cords (SCs) of Lewis rats with EAE were isolated in order to permit flow cytometric (FCM) analysis of these cell populations, using monoclonal antibody to T cell, CD4, CD8. MHC class II antigen (Ia), intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1). The number of MNCs isolated from SC varied from 5 to 620 x 10(4). They were increased and reached a peak on day 2 post clinical onset, and subsequently declined through the clinical course. The increase of infiltrating cells in SC paralleled the severity of the disease development. The surface phenotypes of MNCs from rats on the day of clinical onset were determined by flow cytometry. The phenotypes found in these rats were as follows: T cells (70.3%); CD4 + (58.3%); CD8 + (40.3%); Ia (51.9%); ICAM-1 (62.6%); LFA-1 (75.8%). These findings suggest that high proportion of ICMA-1 and LFA-1 expression may be important in antigen presentation in the inflammatory lesions of SC and in promoting lymphocyte extravasation across the blood-brain barrier during the disease. The approach we employed offered more sophisticated and quantitative analysis of CNS inflammatory cells, which is unobtainable by tissue section staining.

[Inflammatory mechanisms in nervous system]

Experimental autoimmune encephalomyelitis (EAE), is a neuroautoimmune inflammatory disease, involving sensitization to central nervous system myelin basic protein (MBP). Our studies of the coagulation system and ensuing fibrinolysis implicate coagulation and cleavage of fibrin within or on the luminal surface of the cerebrovasculature, as events initiating the inflammation characterizing EAE. Among recipient rats injected with MBP-primed, cultured-activated lymph node cells, "opening" the blood-brain barrier (BBB) and deposition of perivascular fibrin within the spinal cord occur in parallel one day before onset of clinical signs of EAE. The critical event precipitating EAE is a binding of circulating MBP-reactive immune effector cells to MBP immunodeterminants on the surface of cerebrovascular endothelial cells. Coagulation and ensuring fibrinolysis occur at sites of binding of effector cells to cerebrovascular endothelium. Release of biologically active peptides, cleaved from fibrin, "open" the BBB. Once BBB is opened, even transiently, the stage is set for a complex cascade of immunologically-nonspecific inflammatory events, which plays an important role in the development of tissue damage, including demyelination.

Oxygen scavengers in simple bone cysts

Simple bone cyst is a fluid-filled, cystic lesion that occurs in the metaphysis of the long bones of children and adolescents. The chemical characteristics of the cyst fluid of the simple bone cyst are similar to those of serum. The existence of the cyst fluid itself may be an obstacle to cyst healing, and, in part, this may be because the cyst fluid contains bone destructive factors. Oxygen-free radicals, which are cytotoxic and cause connective tissue damage, are known to be generated under ischemic conditions. Blockage to the drainage of interstitial fluid within the metaphysis has been suggested as the possible primary cause of simple bone cyst, thus causing an ischemic state in which free radicals are generated. The precise measurement of free radical levels is difficult to obtain because of their extremely short half-lives. High levels of oxygen-free radicals induce high levels of oxygen scavengers locally to protect cells from the harmful effects of the free radicals. Therefore, the activity of the oxygen scavengers, superoxide dismutase and catalase, was measured in the cyst fluid of 9 cases of simple bone cyst as an indicator of high oxygen-free radical content in the cyst. Serum from the patients with simple bone cyst and joint fluid from patients with osteoarthritis were used for comparison with the intracystic levels of oxygen scavengers. Superoxide dismutase activity was directly measured at room temperature using an electron spin resonance spin-trapping technique with 5,5'-dimethyl-1-pyrroline-N-oxide as a trapping agent.(ABSTRACT TRUNCATED AT 250 WORDS)

[A study on subpopulation of helper T cells in chronic inflammatory demyelinating polyneuropathy]

Chronic inflammatory demyelinating polyneuropathy (CIDP) is thought to be an inflammatory autoimmune disease against peripheral myelin. Recently several animal models have suggested that preferential activation of Th1 cell response is central to the pathogenesis of this disease. We studied the function of CD4 positive T cell subsets, Th1 cells and Th2 cells by analyzing their representative secreting cytokines. Th1 cells secrete Interferon gamma (IFH gamma) and Th2 cells secrete Interleukin 4 (IL4). Using enzyme linked immunospot (ELISPOT) assay, a very sensitive single cell analysis system, we enumerated IFN gamma and IL4 secreting peripheral blood lymphocytes in patients with CIDP. Also we examined these cytokines in supernatants of cultured peripheral blood lymphocytes by a very sensitive enzyme linked immunosorbent assay (ELISA), Immunodot assay and westernblot assay. In culture supernatants of CIDP patients' peripheral blood lymphocytes, the levels of both IFN gamma and IL4 were higher during the exacerbation stage than the remission stage. In the remission period, though the levels of IFN gamma and IL4 were low in the supernatants, the ELISPOT assay revealed that the number of IL4 secreting cells was elevated compared with that of IFN gamma secreting cells. Our results suggest that the switch from Th1 to Th2 might play an important role in inducing the remission stage in patients with CIDP.

Variations in the thoracic duct of the Japanese monkey (Macaca fuscata)

Variations in the thoracic duct of Japanese monkeys were compared with previous reports on the human (Japanese) thoracic duct. The most striking difference between man and the Japanese monkey was that in the majority of the monkeys examined the right thoracic duct ascended without crossing to the left side whereas in man the upper portion of the right duct crosses over to the left. Although most thoracic ducts in man, other primates and domestic animals reportedly enter the left venous angle, about half of the ducts of Japanese monkeys enter the right venous angle. A ring configuration in the thoracic duct was found in 24.4% of Japanese monkeys. This was less frequent than human Japanese. Three out of 41 monkeys had an intercalated lymph node, situated between the 10th and 11th and 12th thoracic vertebrae; this has only occasionally been reported in man.