Modulation of the kallikrein/kinin system by the angiotensin-converting enzyme inhibitor alleviates experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Bradykinin is the end-product of the kallikrein/kinin system, which has been recognized as an endogenous target for combating CNS inflammation. Angiotensin-converting enzyme (ACE) inhibitors influence the kallikrein/kinin system and reportedly have immunomodulatory characteristics. The objectives of this study were to determine whether bradykinin is involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and whether bradykinin control by the ACE inhibitor could be a therapeutic target in MS. The ACE inhibitor enalapril (1·0 or 0·2 mg/kg/day) was administered orally to EAE mice and the serum levels of bradykinin and cytokines in EAE mice were analysed. As a result, the administration of enalapril increased serum bradykinin levels, decreased the clinical and pathological severity of EAE and attenuated interleukin-17-positive cell invasion into the CNS. Additionally, bradykinin receptor antagonist administration reduced the favourable effects of enalapril. Our results suggest that bradykinin is involved in the pathomechanism underlying CNS inflammation in EAE, possibly through inhibiting cell migration into CNS. Control of the kallikrein/kinin system using ACE inhibitors could be a potential therapeutic strategy in MS.

Anti-high mobility group box 1 monoclonal antibody ameliorates experimental autoimmune encephalomyelitis.

High mobility group box 1 (HMGB1) is an established inflammatory mediator when released from cells. Recent studies have implicated extracellular HMGB1 in the pathogenesis of various autoimmune diseases. The objective of this study was to determine whether HMGB1 could be a therapeutic target for experimental autoimmune encephalomyelitis (EAE). In this study, an anti-HMGB1 monoclonal antibody was injected intraperitoneally into a mouse model of EAE. We also measured serum cytokines levels in EAE and anti-HMGB1 monoclonal antibody-treated EAE. As a result, intraperitoneal injection of an anti-HMGB1 monoclonal antibody ameliorated the clinical and pathological severity of EAE and attenuated interleukin-17 up-regulation in serum. In conclusion, HMGB1 is involved in EAE pathogenesis and could trigger inflammation in the central nervous system. The novel aspect of this study is the demonstration that anti-HMGB1 ameliorates EAE. HMGB1 may be a novel therapeutic strategy for multiple sclerosis.

Neogenin regulates neuronal survival through DAP kinase.

The repulsive guidance molecule (RGM) is a membrane-bound protein that has diverse functions in the developing central nervous system. Identification of neogenin as a receptor for RGM provided evidence of its cell death-inducing activity in the absence of RGM. Here, we show that the serine/threonine kinase death-associated protein kinase (DAPK) is involved in the signal transduction of neogenin. Neogenin interacts with DAPK and reduces DAPK autophosphorylation on Ser308 in vitro. Neogenin-induced cell death is abolished in the presence of RGM or by blocking DAPK. Although neogenin overexpression or RGM downregulation in the chick neural tube in vivo induces apoptosis, coexpression of the dominant-negative mutant or small-interference RNA of DAPK attenuates this proapoptotic activity. Thus, RGM/neogenin regulates cell fate by controlling the DAPK activity.

Rap1 is involved in the signal transduction of myelin-associated glycoprotein.

Myelin-associated glycoprotein (MAG) is a well-characterized axon growth inhibitor in the adult vertebrate nervous system. Several signals that play roles in inhibiting axon growth have been identified. Here, we report that soluble MAG induces activation of Rap1 in postnatal cerebellar granule neurons (CGNs) and dorsal root ganglion (DRG) neurons. The p75 receptor associates with activated Rap1 and is internalized in response to MAG. After MAG is applied to the distal axons of the sciatic nerves, the activated Rap1, internalized p75 receptor, and MAG are retrogradely trafficked via axons to the cell bodies of the DRG neurons. Rap1 activity is required for survival of the DRG neurons as well as CGNs when treated with MAG. The transport of the signaling complex containing the p75 receptor and Rap1 may play a role in the effect of MAG.

Inhibition of amiloride-sensitive apical Na+ conductance by acetylcholine in rabbit cortical collecting duct perfused in vitro.

We examined effects of acetylcholine (ACh) on the electrical parameters and intracellular Ca2+ concentration ([Ca2+]i) in the isolated rabbit cortical collecting duct (CCD) perfused in vitro using the conventional microelectrode technique and microscopic fluorescence spectrophotometry. ACh (10(-8) to 10(-5) M) in the bath caused a positive deflection of the transepithelial voltage (VT) and an increase in [Ca2+]i. Carbachol also showed similar but smaller effects. The effects of ACh were antagonized by muscarinic receptor antagonists. ACh at 10(-6) M hyperpolarized the apical membrane voltage and increased the fractional resistance of the apical membrane of the collecting duct cells accompanied by a positive deflection of VT and an increase in transepithelial resistance, whereas it did not affect these parameters in the beta-intercalated cells. In the presence of 10(-5) M amiloride in the lumen, the effects of ACh were almost completely abolished. The ACh-induced increase in [Ca2+]i is accounted for by the release of Ca2+ from intracellular store and Ca2+ entry from the bath. In the absence of Ca2+ in the bath, the ACh-induced changes in electrophysiological parameters were significantly smaller than those observed in the presence of Ca2+. Both phorbol-12-myristate-13-acetate (PMA) and phorbol-12,13-dibutylate (PDBu), activators of protein kinase C (PKC), also inhibited the apical Na+ conductance. In the presence of PMA or PDBu in the bath, ACh did not show further inhibitory effect. 1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine, an inhibitor of PKC, partially attenuated the effect of ACh. These observations indicate that ACh inhibits the apical Na+ conductance partly by both increasing [Ca2+]i and activating PKC. Such an action of ACh may partially explain its natriuretic effect.

KMD-3213, a novel alpha1A-adrenoceptor antagonist, potently inhibits the functional alpha1-adrenoceptor in human prostate.

KMD-3213, (-)-(R)-1-(3-hydroxypropyl)-5-[2-[[2-[2-(2,2,2-trifluoroethoxy)phe noxy]ethyl]amino]propyl]indoline-7-carboxamide, is a novel and selective alpha1A-adrenoceptor antagonist. The potency of this drug to antagonize functional alpha1-adrenoceptor-mediated contraction in human prostatic smooth muscle was evaluated and compared with that of other alpha1-adrenoceptor antagonists. KMD-3213 inhibited noradrenaline-induced contractions with an apparent pK(B) value of 9.45 +/- 0.039, indicating a potency similar to that of tamsulosin. The affinity of prazosin for prostatic alpha1-adrenoceptors is given as potency for the alpha1L-adrenoceptor with an estimated pA2 value of 8.84 +/- 0.044. The data obtained in this study suggest that KMD-3213, an alpha1A-adrenoceptor-selective antagonist, has strong affinity for the alpha1L-adrenoceptor in the human prostate.

Evaluation of a rheumatoid arthritis patient education program: impact on knowledge and self-efficacy.

We have evaluated the effects of an education program on the knowledge and self-efficacy of 51 rheumatoid arthritis patients, using two previously validated questionnaires. At completion of the program, both knowledge and self-efficacy were significantly improved and this was maintained at follow-up. However, there was no correlation between knowledge and self-efficacy at baseline and follow-up, suggesting that these variables improved independently of each other. We conclude that education programs are a worthwhile means of improving the non-medical causes of morbidity in rheumatoid arthritis patients and that the two instruments utilized are a valuable means of both demonstrating effectiveness and quality assurance.

Transient kinetics of an inward rectifier K+ channel in the myocardial cell membrane.

The current through a myocardial inward rectifier K+ channel was recorded by the patch clamp technique. The inactivation gate of the channel has open probability of nearly 1 at the potentials positive to EK and showed peculiar kinetics in the 1st open events after hyperpolarization from these potentials. Analysis of this kinetics suggested two open states in this gate.

Regulation of Cl- conductance in the thin ascending limb of Henle's loop.

Characteristics of the ion transport of the ascending thin limb of Henle's loop (ATL) were reviewed with special reference to the regulatory mechanisms of the putative Cl- channel. The ATL is highly permeable to NaCl, moderately permeable to urea, and virtually impermeable to water. The Cl- permeability is extremely high, having saturation kinetics and being inhibited by halogens. The Cl- conductances exist in series in both apical and basolateral membranes. They are inhibited by anion transport inhibitors including DIDS, phloretin, and NPPB. The Cl- conductance is pH sensitive and activated by Ca2+. NEM exhibits dual action on this conductance: irreversible inhibition and reversible stimulation. This highly effective Cl- transport system is favorable for the operation of the countercurrent multiplication system in the renal medulla.

Spontaneously active cells isolated from the sino-atrial and atrio-ventricular nodes of the rabbit heart.

Single cells or cell clusters composed of 3-10 cells were isolated from the S-A and A-V nodes of the rabbit heart by coronary perfusion of collagenase dissolved in Ca-free Tyrode solution (0.04%, for 1 hr). For comparison, atrial and ventricular cells were also isolated from the same heart. Shapes of the isolated nodal cell were either rod or round and nodal cells were slightly smaller than ventricular cells. Spontaneous activity was observed in both rod and round nodal cells. The action potentials had the configurations similar to those recorded from larger conventional preparations. The membrane current recorded from the small nodal cell clusters (5-10 cells) by the two-microelectrode voltage clamp technique showed a time course similar to that of previous recordings from conventional preparations, but the amplitude of the currents was 5-10 times smaller. The isolated cells showed normal sensitivities to both acetylcholine and epinephrine. Findings given in this study indicate that the isolated cells maintain the typical membrane characteristics of the nodal cells and that they are suitable for electrophysiological studies of the cardiac pacemaker cell.

Follicular dendritic cell sarcoma: ultrastructural and immunohistochemical studies.

A rare case of follicular dendritic cell (FDC) sarcoma is reported. A 71-year-old woman was admitted for evaluation of constipation. Computerized tomography showed cervical, supraclavicular, retroperitoneal, and paraaortic lymphadenopathies. Histological findings from a cervical lymph node revealed Hodgkin's disease at first. But tumors that arose both in the cervical and the left interscapular regions during the chemotherapy were immunohistochemically confirmed to be of follicular dendritic cell origin. The ultrastructural findings were consistent with those of FDC sarcoma. FDC sarcoma is a rare nonlymphoid cell-derived malignant tumor originating from the lymphoid tissue. The diagnosis of FDC sarcoma is most accurately established by immunohistochemical methods, using its specific markers.

[Histochemical study of biotinylated lectins in prostatic cancer].

We examined the staining pattern of various lectins in the malignant and benign prostatic tissues to clarify the difference of sugar residues of mucosubstances between them. The binding of different lectins (Concanavalia ensiformis [Con A], Triticum vulgaris [WAG], Ricinus communis [RCA-I], Arachis hypogaea [PNA], Ulex europaeus [UEA-I], Glycine max [SBA], and Gliffonia simplicifolia II [GSA-II]) to cells of benign prostatic tissues (17 cases) and adenocarcinoma (54 cases) was evaluated immunohistochemically. SBA which was negative in benign epithelial cells, showed tendency to the binding to prostatic carcinoma (42.6%). UEA-I was significantly bound to the adenocarcinoma (68.5%) compared to the benign prostatic tissue (35.3%). We also examined histochemically 25 pairs of tissues obtained from prostatic adenocarcinoma before and after the various therapies with various lectins. The histological responsiveness on the post-therapeutic specimens showed a significant correlation to the clinical responsiveness to therapy. But the staining pattern of these 7 lectins on the pre-therapeutic specimens did not show a significant correlation to the clinical responsiveness to therapy. In summary, the staining pattern of some lectins in the prostatic cancers is different from that in the benign prostatic tissues.

[Role of interstitium in the regulation of renal tubular solute transport].

The physiological significance of the renal interstitium is reviewed with special reference to solute transport. The renal tubules and vasculatures participate in essential parts of the nephron functions. The renal interstitium, interposing among these structures, regulates solute transport across the renal tubules. In the renal cortex, changes in the interstitial pressure modulate the proximal tubular fluid reabsorption via paracellular shunt pathways. In the renal medulla, the interstitium may play an important role in the lateral diffusion of solutes and water, contributing to the mechanisms of urine concentration, as well as, medullary potassium recycling and ammonia excretion.

The subthalamic activity and striatal monoamine are modulated by subthalamic stimulation.

AIMS: Not all the mechanisms by which subthalamic nucleus deep brain stimulation (STN-DBS) alleviates parkinsonian symptoms have been clarified as yet. The levels of striatal monoamine and the subthalamic beta activity might contribute to its efficacy. However, their direct relationship is unclear. We aimed to examine the correlation between the striatal monoamine and the STN beta activity induced by STN-DBS. EXPERIMENTAL PROCEDURES: Experiments were performed under urethane anesthesia in normal (n=4) and 6-hydroxydopamine hemi-lesioned Parkinson's disease (PD) model rats (n=5). STN-DBS was applied to the left STN, and local field potential (LFP) was recorded before and after STN-DBS. Striatal extracellular fluid was collected before, during, and after STN-DBS. Spectral analysis of STN-LFP was performed, and the levels of monoamine were measured. RESULTS: The levels of 3-4-dihydroxyphenylacetic acid (DOPAC) were significantly decreased after the cessation of stimulation in PD model rats. The levels of none of the monoamines were significantly affected in normal rats. The STN beta power was significantly elevated after the cessation of stimulation in normal rats but was significantly decreased in PD model rats. The STN beta power and the levels of DOPAC and 5-HT was positively correlated in PD model rats, whereas the levels of dopamine and 5-HT showed positive correlation and the levels of DOPAC and Homovanillic acid (HVA) showed negative correlation in normal rats. CONCLUSION: STN-DBS could decrease the levels of DOPAC and the STN beta power in a PD model rat. The STN beta power and the levels of striatal monoamine might be differentially correlated between normal and PD model rats.

High-contrast plasma-electrode Pockels cell.

A plasma-electrode Pockels cell (PEPC) has been developed for use on the OMEGA extended performance (EP) laser system that can be used in a high-contrast optical switch, as required for isolation of the system from retroreflected pulses. Contrast ratios reliably exceeded 500:1 locally everywhere in the clear aperture. The key to achieving this improvement was the use of circular windows simply supported on compliant O rings, which is shown to produce very low stress-induced birefringence despite vacuum loading. Reliable operation was achieved operating at a relatively high operating pressure, low operating pressures being found to be strongly correlated to occurrences of local loss of plasma density.

A Ca2+ channel in renal epithelial cells introduced by parathyroid hormone.

To investigate the mechanism of Ca2+ influx after hormonal stimuli, patch clamping with [Ca2+]i fluorescence measurement was performed in single renal proximal epithelial cells. A Ca2+ current appeared along with a rise in [Ca2+]i during parathyroid hormone addition to the bath, but not when the hormone was inside the cell-attached pipette. The Ca2+ channel, possessing linear I-V, was nonselective for cations, most active in hyperpolarized--membranes and showed oscillatory fluctuations in opening, which disappeared after excision. GTP gamma S opened the channel that had disappeared, which was suppressed by GDP beta S. These data show a PTH-responsive Ca2+ channel for which GTP/GDP may act as second messenger to open the latent Ca2+ channel.