Suppressor T-lymphocyte dysfunction in MCNS: role of the H2 histamine receptor-bearing suppressor T lymphocytes

To evaluate the number and function of suppressor T cells in children with minimal change nephrotic syndrome (MCNS), we performed an inhibition test of rosette formation and measured leukocyte procoagulant activity. The number of histamine H2 receptor-bearing T lymphocytes (histamine H2 R+ lymphocytes) was markedly decreased at the onset of MCNS but gradually increased and was normalized following steroid therapy. The production of leukocyte procoagulant activity by normal T lymphocytes was abolished by incubation with patient's lymphocytes. However, pretreatment of the normal T lymphocytes with cimetidine markedly decreased the suppression. The results suggest an abnormality in the histamine H2 receptors on the patient's suppressor T lymphocytes.     

Stimulation of nonspecific resistance to infection induced by 6-O-acyl muramyl dipeptide analogs in mice.

The experimental system utilized in investigating the correlation between the chemical structures of muramyl peptides and their protective activities in the sepsis type of systemic infections caused by Escherichia coli was applied in evaluating the enhancement of resistance to infection induced by 32 synthetic glycopeptide analogs, including 6-O-acyl derivatives and 1-alpha-O-benzyl derivatives of muramyl dipeptide (N-acetyl muramyl-L-alanyl-D-isoglutamine). In assessing the 6-O-acyl derivatives of muramyl dipeptide, we found that the degree of protective activity was attributable to the kinds of fatty acids introduced. Acylation of the 6-hydroxy group on the muramic acid moiety in muramyl dipeptide with natural mycolic acid or a synthetic fatty acid possessing either an alpha-branched or an alpha-branched, beta-hydroxylated group resulted in a decrease in or a disappearance of the protective activity of muramyl dipeptide. Acylation with a normal fatty acid or an iso fatty acid resulted in a retention or enhancement of muramyl dipeptide activity. The activity of acylated derivatives containing linear fatty acids was stimulated by increasing the chain length up to 18 carbon atoms. The highest degree of protective activity occurred with the derivatives acylated with straight-chain fatty acids, particularly with the derivatives acylated with palmitic acid and arachidic acid. Benzylation of the 1-hydroxy group of muramyl dipeptide resulted in a decrease in or a loss of protective activity.     

Abnormal expression of complement receptor (CR1) in IgA nephritis: increase in erythrocytes and loss on glomeruli in patients with impaired renal function

The number of complement receptor for C3b (CR1) molecules in erythrocytes from patients with renal diseases was measured by an immunoradiometric assay using monoclonal antibodies against CR1. IgA nephritis patients with high serum creatinine value (Scr) showed markedly elevated levels of CR1, whereas patients with normal Scr had normal CR1 levels. A similar increase in CR1 number was observed in membranoproliferative glomerular nephritis with high Scr. CR1 of these patients functioned normally as a cofactor of C3b inactivator in cleaving immune complex-bound C3b. In contrast, a high frequency (5/6) of negative staining of glomerular CR1 was observed in IgA nephritis patients with high Scr by immunofluorescence study. We postulate that the disease-associated, acquired factors at least in part contribute to the abnormal expression of CR1: elevated levels in erythrocytes and defective expression on glomeruli.     

Effect of chemical cationization of antigen on glomerular localization of immune complexes in active models of serum sickness nephritis in rabbits.

The effect of chemical cationization of antigen on the glomerular localization and formation of immune complexes (IC) was investigated utilizing the models of acute accelerated and chronic serum sickness nephritis in rabbits. In acute accelerated serum sickness, neither antibody nor antigen was detected in the glomerulus before the second injection of antigen. At 15 min after the challenge, rabbits given cationized BSA developed IC deposition along the peripheral capillary walls, whereas no IC deposition was found in rabbits given native BSA. In chronic serum sickness, rabbits injected with a high dose (5 mg/rabbit/day), but not a low dose (500 micrograms/rabbit/day) of cationized BSA developed membranous nephropathy with severe proteinuria. In the group given cationized BSA, the levels and avidity of antibodies were lower than in the group given native BSA. Sucrose density gradient analysis of the complexes composed of 125I-cationized BSA showed that IC formed in vivo were slightly larger than 7S. These antibody characteristics, i.e. low precipitation and low avidity, continued from early on to the late period of immunization. These results suggest that chemical cationization altered the immunogenicity of the antigen and resulted in the formation of antibody of low precipitability and low avidity, even during long-term immunization.     

Decreased calcitonin gene-related peptide expression in the dorsal root ganglia of TNF-deficient mice in a monoiodoacetate-induced knee osteoarthritis model

Background: The detailed mechanisms of knee osteoarthritis (OA) pain have not been clarified, but involvement of inflammatory cytokines such as tumor necrosis factor-alpha (TNF) has been suggested. The present study aimed to investigate the more detailed neurological involvement of TNF in joint pain using a TNF-knockout mouse OA model. Methods: The right knees of twelve-week-old C57BL/6J wild and TNF-deficient knockout (TNF-ko) mice (n=15, each group) were given a single intra-articular injection of 10 µg monoiodoacetate in 10 mL sterile saline. The left knees were only punctured as the control. Evaluations were performed immediately after the injection (baseline) and at 7, 14, and 28 days after the injection with a subsequent intra-articular injection of neurotracer into both knees. The animals were evaluated for immunofluorescence of the lumbar dorsal root ganglia (DRG) innervating the knee joints. The injected knees were observed macroscopically and mouse pain-related behaviors were scored. Results: Macroscopic observation showed similar knee OA development in both wild and TNF-ko mice. Calcitonin gene-related peptide (CGRP, a neuropeptide identified as a inflammatory pain-related biomarker) was significantly increased in DRG neurons innervating OA-induced knee joints with significantly less CGRP expression in TNF-ko animals. Pain-related behavior scoring showed a significant increase in pain in OA-induced joints, but there was no significant difference in pain observed between the wild and TNF-ko mice. Conclusions: The result of the present study indicates the possible association of TNF-alpha in OA pain but not OA development.     

Longitudinal evaluation of local muscle conditions in a rat model of gastrocnemius muscle injury using an in vivo imaging system

This study aimed to evaluate the time course of local changes during the acute phase of gastrocnemius muscle strain, in a rat model, using an in vivo imaging system. Thirty‐eight, 8‐week‐old Sprague‐Dawley male rats were used in our study. Experimental injury of the right gastrocnemius muscle was achieved using the drop‐mass method. After inducing muscle injury, a liposomally formulated indocyanine green derivative (LP‐iDOPE, 7 mg/kg) was injected intraperitoneally. We evaluated the muscle injuries using in vivo imaging, histological examinations, and enzyme‐linked immunosorbent assays. The fluorescence peaked approximately 18 h after the injury, and decreased thereafter. Histological examinations revealed that repair of the injured tissue occurred between 18 and 24 h after injury. Quantitative analyses for various cytokines demonstrated significant elevations of interleukin‐6 and tumor necrosis factor‐α at 3 and 18 h post‐injury, respectively. The time course of fluorescence intensity, measured using in vivo imaging, demonstrated that the changes in cytokine levels and histopathologic characteristics were consistent. Specifically, these changes reached peaked 18 h post‐injury, followed by trends toward recovery. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1034–1038, 2015.     

Glutamate transporters in neonatal cerebellar subarachnoid hemorrhage

We have previously described the immunoreactivities of glutamate transporters, EAAT4 and GLAST, in the developing human cerebellum. In the present report, we demonstrate the different expression of EAAT4 and GLAST in the pathologic condition, neonatal subarachnoid hemorrhage. EAAT4 and GLAST were characteristically disturbed in the cerebellar cortices beneath the subarachnoid hemorrhage. In preterm infants with subarachnoid hemorrhage the decrease in EAAT4 immunoreactivity was more prominent than in term infants, and GLAST immunoreactivity in the inner granular cell layer decreased and reappeared later than in term infants with subarachnoid hemorrhage. Although Bergmann's glia removes glutamate from the extracellular space surrounding Purkinje cells in the early stage of hypoxic-ischemic brain damage, the reaction of EAAT4 and GLAST in the cerebellar cortex under the subarachnoid hemorrhage was decreased, and immature glia had a delayed reaction. These characteristics of glutamate transporters in immature cells may lead to cell death and olivocerebellar degeneration.     

Mass of the postsynaptic density and enumeration of three key molecules

The total molecular mass of individual postsynaptic densities (PSDs) isolated from rat forebrain was measured by scanning transmission EM. PSDs had a mean diameter of 360 nm and molecular mass of 1.10 +/- 0.36 GDa. Because the mass represents the sum of the molecular masses of all of the molecules comprising a PSD, it becomes possible to derive the number of copies of each protein, once its relative mass contribution is known. Mass contributions of PSD-95, synapse-associated protein (SAP)97, and alpha-Ca2+/calmodulin-dependent protein kinase II (CaMKII) were determined by quantitative gel electrophoresis of PSD fractions. The number of PSD-95 molecules per average PSD, contributing 2.3% of the mass of the PSD, was calculated to be 300, whereas the number of SAP97 molecules, contributing 0.9% of the mass of the PSD, was 90. The alpha-CaMKII holoenzymes, which contribute 6% of the mass when brains are homogenized within 2 min of interrupting blood flow, have 80 holoenzymes associated with a typical PSD. When blood flow is interrupted 15 min before homogenization, the average mass of PSDs increases by approximately 40%. The additional alpha-CaMKII associated with PSDs accounts for up to 20% of this mass increase, representing the addition of 100-200 alpha-CaMKII holoenzymes.