Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan.

BACKGROUND: The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients. MATERIALS AND METHODS: Thirty-five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1-week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 x 10(9) L(-1) were defined as idiopathic thrombocytopenic purpura responders. RESULTS: Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 x 10(9) L(-1) in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori-negative patients experienced the same improvement (P = 0.015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0.015). CONCLUSIONS: Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.

Prolonged effects of polyriboinosinic:polyribocytidylic acid on spontaneous running wheel activity and brain interferon-alpha mRNA in rats: a model for immunologically induced fatigue.

Following 2 weeks acclimation to the running wheel in the home cages, an i.p. injection of a synthetic double-stranded RNA, polyriboinosinic:polyribocytidylic acid (poly I:C, 3 mg/kg), was performed to produce the immunologically induced fatigue in rats. The daily amounts of spontaneous running wheel activity decreased to about 40-60% of the preinjection level until day 9 with normal circadian rhythm, then gradually returned to the baseline level by day 14. Rats given a heat exposure (36 degrees C for 1 h) for the consecutive 3 days showed an increase in activity except for the first day. In the open field test, the total moving distance and the number of rearing of the poly I:C-injected rats decreased on day 1, but they were not different from the saline-injected group on day 7, suggesting that the poly I:C-induced fatigue on day 7 was not due to the peripheral problems such as muscle/joint pain, but involved the CNS. Quantitative analysis of mRNA levels using a real-time capillary reverse transcriptase-polymerase chain reaction (RT-PCR) method revealed that interferon-alpha (IFN-alpha) mRNA contents in the cortex, hippocampus, hypothalamic medial preoptic, paraventricular, and ventromedial nuclei were higher in the poly I:C group than those in the saline and heat-exposed groups on day 7, although the amount of interleukin-1 beta mRNA showed no differences. Serum adrenocorticotropic hormone and catecholamine levels were not significantly different between groups. The present results indicate that the prolonged fatigue induced by poly I:C, which is evaluated by the spontaneous running wheel activity, can be used as an animal model for the immunologically induced fatigue associated with viral infection, and suggest that brain IFN-alpha may play a role in this model.

Expression of vascular endothelial growth factor in patients with testicular germ cell tumors as an indicator of metastatic disease.

BACKGROUND: Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor (PD-ECGF) are involved in increased angiogenic activity and disease progression in solid tumors. However, there is no information regarding the association of these angiogenic factors with clinicopathologic findings in testicular germ cell tumors (GCTs). METHODS: The authors examined the expression of VEGF and TP as well as microvessel density in GCTs and their association with clinicopathologic findings. Expression of VEGF and TP and microvessel density were examined immunohistochemically in 80 GCTs, including 33 seminomas (25 tumors with organ-confined disease and 8 with metastasis) and 47 nonseminomatous testicular GCTs (NSGCTs) (20 tumors with organ-confined disease and 27 with metastasis). Expression of VEGF also was examined in four GCTs and one nonneoplastic testis by immunoblotting. RESULTS: VEGF protein was expressed more highly in GCTs compared with nonneoplastic testes. VEGF expression in GCTs was correlated significantly with microvessel count (P < 0.001). Both VEGF expression and microvessel count were correlated with metastasis in seminoma (P = 0.008 and P < 0.001, respectively), but only VEGF expression was identified as statistically significant by multiple regression analysis (P = 0.006). Conversely, four variables (VEGF expression, microvessel count, the presence of venous invasion, and the presence of embryonal carcinoma elements in the primary tumor) were correlated with metastasis in NSGCT (P < 0.001, P < 0.001, P = 0.004, and P = 0.029, respectively). However, multiple regression analysis revealed that only VEGF expression and microvessel count were significant factors for metastasis (P < 0.007 and P < 0.001, respectively). In contrast, high levels of TP were observed in infiltrating cells, but not in the majority of cancer cells. CONCLUSIONS: The findings of the current study suggest that VEGF expression is involved in tumor development, angiogenesis, and metastasis in GCT.

Neuroimmunomodulatory actions of hypothalamic interferon-alpha.

Recent studies have revealed that the brain produces interferon-alpha (IFN-alpha) in response to noninflammatory as well as inflammatory stress and that it might have a role in normal physiology. When administered intracerebrally, IFN-alpha causes diverse effects including fever, anorexia, analgesia and changes in the central neuronal activities. These responses are inhibited by the opioid receptor antagonist naloxone. This is consistent with the reports suggesting that recombinant human (rh) IFN-alpha binds to opioid receptors in rodent brain membrane. We revealed that rhIFN-alpha altered the activity of thermosensitive neurons in the medial preoptic area (MPO) and glucose-responsive neurons in the ventromedial hypothalamus in an opioid-receptor-dependent way. As a stress which produces opioid-dependent analgesia is known to suppress the cytotoxicity of splenic natural killer cells, we investigated whether the administration of beta-endorphin and rhIFN-alpha may induce a similar immunosuppression. We found that central, but not peripheral, injection of both compounds inhibited natural killer (NK) cytotoxicity. Further studies revealed that rhIFN-alpha decreased the activity of MPO neurons via opioid receptors and the altered activity of MPO neurons in turn resulted in the activation of corticotropin-releasing factor neurons, thereby suppressing NK cytotoxicity predominantly through activation of the splenic sympathetic nerve and beta-receptor mechanisms in splenocytes. Thus, IFN-alpha may alter the brain activity to exert a feedback effect on the immune system. Further detailed whole-cell clamping analyses on neuronal mechanisms in rat brain tissue slices showed that the inhibitory effect of rhIFN-alpha on N-methyl-D-aspartate-induced membrane current responses of MPO neurons was mediated not only by opioid receptors but also by the local production of reactive oxygen intermediates, nitric oxide and prostanoids, possibly due to neuron-glial cell interaction.

Effect of cilostazol in preventing restenosis after percutaneous transluminal coronary angioplasty.

This study sought to evaluate the effect of cilostazol in preventing restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) in 68 patients: 35 patients received cilostazol immediately after PTCA and 33 patients received aspirin or ticlopidine. Repeat coronary angiography was performed 4 to 6 months after PTCA and the incidence of restenosis was significantly lower (17%) in the cilostazol group than in the non-cilostazol group (40%) (p < 0.05), which indicates that cilostazol has the potential to prevent restenosis after PTCA.

The autonomic nervous system as a communication channel between the brain and the immune system.

Much evidence from various fields has revealed multiple channels of communication between the brain and the immune system. Among the routes of signal transmission, this review focuses on the roles and mechanisms of neural communication between the two systems. As for the centrifugal neural pathway by which the brain modulates immunity, there are various requirements for the noradrenergic sympathetic innervation of the primary and secondary lymphoid organs. In addition to the presence of beta- and alpha-adrenergic receptors on different types of immunocompetent cells, histological studies have demonstrated direct contact between tyrosine-hydroxylase-positive nerve terminals and lymphocytes in the spleen and thymus. The exposure of lymphocytes and macrophages to adrenergic agonists in vitro modulates their functions. A surgical or chemical sympathectomy is known to alter the immune responses in rodents. Recent data from the rat show that stress-induced immunosuppression is only slightly affected, if at all, by hypophysectomy or adrenalectomy, whereas it is largely dependent on sympathetic innervation. The splenic sympathetic nerve alters the firing rate by an ablation or stimulation of the hypothalamus, the administration of cytokines or neuropeptides, and an exposure to stress. Furthermore, such procedures provoke the increase in the release of noradrenaline in the rat spleen as assessed by in vivo microdialysis. The altered activities of the splenic sympathetic nerves mentioned above have been found to be causally related to the alteration in immunological responses including natural killer cytotoxicity. The splenic sympathetic nerve may thus constitute a communication channel that mediates central modulation of peripheral cellular immunity. Although the roles and mechanisms of parasympathetic control of lymphoid organs still remain obscure, recent data suggest that the thymic vagal efferent nerve may be involved in central modulation of immunity. Finally, electrophysiological studies have shown that hepatic vagal afferents may be one of the pathways through which blood-borne cytokines signal the brain.

Interferon-alpha acts at the preoptic hypothalamus to reduce natural killer cytotoxicity in rats.

We previously demonstrated that an intracerebroventricular injection of recombinant human interferon-alpha (rhIFN-alpha) reduced the cytotoxicity of splenic natural killer (NK) cells in rats and mice. In the present study, we investigated the brain sites at which rhIFN-alpha acts to suppress splenic NK activity in unanesthetized rats implanted unilaterally with a chronic hypothalamic cannula. A microinjection of 200 U of rhIFN-alpha into the medial part of the preoptic hypothalamus reduced NK activity to approximately 60% of control 30 min after the injection. Administration of 50 U of rhIFN-alpha also decreased NK activity to approximately 80%. The injection of 200 U of rhIFN-alpha into other hypothalamic areas (lateral preoptic hypothalamus, ventromedial hypothalamus, lateral hypothalamus, and paraventricular nucleus) had no effect. The medial preoptic hypothalamus-rhIFN-alpha-induced immunosuppression was completely blocked by splenic denervation, but not by adrenalectomy. These results suggest that IFN-alpha suppresses splenic NK activity predominantly through the medial preoptic hypothalamus-sympathetic pathway.

The hypothalamo-sympathetic nervous system modulates peripheral cellular immunity.

Our findings reviewed in this article have revealed that the stimulation of opioid receptors of the hypothalamic neurons by interferon alpha and beta-endorphin synthesized in the brain or by stress causing the opioid-dependent analgesia suppresses the natural killer cytotoxicity, an important component of immunosurveillance, through an activation of the hypothalamic CRF-sympathetic nervous system.

Roles of cytokines in the neural-immune interactions: modulation of NMDA responses by IFN-alpha.

Several lines of evidence have indicated that interferon-alpha (IFN-alpha) induces a variety of central actions; e.g., fever anorexia, slow wave sleep and depression. However, little is known about the cellular mechanisms by which IFN-alpha affects neuronal activity. In the present article, the effects of recombinant human IFN-alpha on N-methyl-D-aspartate (NMDA)-induced responses of rat medial preoptic (MPO) neurons were examined by means of slice patch method as an in vitro model of neural-immune interactions. The results suggest that IFN-alpha suppresses the NMDA responses through its action on opioid receptors and the production of free radicals such as hydroxyl radicals and nitric oxide (NO) due to the neuron-glial cell interactions.

The biphasic changes in splenic natural killer cell activity following ventromedial hypothalamic lesions in rats.

The cytotoxic activity of natural killer (NK) cells in the spleen was measured by a standard 4-h chromium release assay following electrical lesioning of the ventromedial hypothalamic nucleus (VMH) in rats. The splenic NK cell activity of VMH lesioned rats was found to be significantly suppressed at effector:target cell ratios of 100:1 and 50:1 compared with that of sham lesioned rats on day 4 after the lesion. On the other hand, on day 49, the VMH lesioned animals that had become hyperphagic and obese showed an enhancement of splenic NK cell activity compared with sham lesioned animals. The mechanisms of the biphasic change in NK cell activity following the VMH lesions are discussed.

Hypothalamic modulation of splenic natural killer cell activity in rats.

1. The cytotoxic activity of splenic natural killer cells measured by a standard chromium release assay in urethane and alpha-chloralose-anaesthetized rats was significantly suppressed 20 min after bilateral ablation of the medial part of the preoptic hypothalamus (MPO). The suppression was completely blocked by prior splenic denervation. The splenic natural killer cell activity of MPO sham-lesioned rats or thalamus-lesioned rats, both having an intact splenic innervation, were not different from that of a non-treated control group. 2. Electrical stimulation of the bilateral MPO (0.1 ms, 0.1-0.3 mA, 5-100 Hz) suppressed the efferent activity of the splenic nerve in all six rats examined. The reduction of the nerve activity was accompanied by a transient fall in blood pressure. An I.V. injection of phenylephrine (3 micrograms/0.3 ml) also evoked a suppression of the nerve activity, which was accompanied by transient hypertension, suggesting that the suppressive effect of the MPO stimulation was independent of changes in blood pressure. On the other hand, a bilateral lesion of the MPO resulted in a sustained increase in the electrical activity of the splenic sympathetic nerve filaments which lasted for more than 2 h. 3. Microinjection of monosodium-L-glutamate (0.1 and 0.01 M in 0.1 microliters saline) unilaterally into the MPO evoked a transient suppression of the efferent discharge rate of the splenic nerve activity within 1 min, which was also accompanied by a decrease in blood pressure. The injection of saline (0.1 microliter) into the MPO had no effect. The microinjection of recombinant human interferon-alpha (200 and 2000 U in 0.1 microliter saline) into the MPO dose dependently increased the splenic nerve activity without any change in blood pressure. 4. In contrast, microinjection of interferon-alpha into the paraventricular nucleus of the hypothalamus (PVN) had no effect on splenic nerve activity, although an injection of glutamate increased the nerve activity. 5. The present results, taken together with previous reports, suggest that the neuronal networks between the MPO and the splenic sympathetic nerve, which may be activated by centrally administered interferon-alpha, are important in the suppression of the splenic cellular immunity.

Central interferon-alpha inhibits natural killer cytotoxicity through sympathetic innervation.

The brain has been known to produce high levels of interferon-alpha (IFN-alpha) during viral infections. We investigated the central and peripheral mechanisms of the brain IFN-alpha-induced suppression of natural killer (NK) cytotoxicity in the rat. The activity of NK cells in the spleen and the peripheral blood decreased 30-120 min after intracerebroventricular (icv) injection of recombinant human IFN-alpha of > 1,000 U but not after its intraperitoneal injection. This effect was antagonized by pretreatment with icv naltrexone (NLTX). Splenic denervation was observed to completely abolish the IFN-alpha-induced suppression of NK activity, whereas bilateral adrenalectomy did not. Furthermore, this immunosuppression was blocked by an icv injection of an antagonist of corticotropin-releasing factor (CRF), alpha-helical CRF-(9-41). The icv injection of CRF resulted in reduced NK activity, which was not affected by NLTX. The results suggest that brain IFN-alpha activates the CRF system through central opioid receptors and thereby suppresses the NK cytotoxicity predominantly through splenic sympathetic innervation.

Roles of sympathetic nervous system in the suppression of cytotoxicity of splenic natural killer cells in the rat.

1. We previously demonstrated that a central injection of interferon-alpha in rats induced a suppression of cytotoxicity of splenic natural killer cells which depended upon intact splenic sympathetic innervation, suggesting the important role of the splenic nerve in immunosuppression. To further study the mechanisms of this phenomenon, we investigated: (1) the effects of a central injection of recombinant human interferon-alpha on the electrical activity of the splenic nerve, and (2) the responses of splenic natural killer cytotoxicity on the electrical stimulation of the splenic nerve in urethane with alpha-chloralose anaesthetized rats. 2. An injection of recombinant human interferon-alpha (1.5 x 10(3) and 6.0 x 10(3) units (u) per rat) into the third cerebral ventricle produced a sustained and long lasting (at least for more than 60 min) increase in the electrical activity of splenic sympathetic nerve filaments in a dose-dependent manner. Following an intra-third-ventricular injection of recombinant human interferon-alpha at a dose of 6.0 x 10(3) u, the efferent discharges were elevated 2-6 times that of the pre-injection level with a mean onset latency of 12 min (8-16 min). No changes in the arterial blood pressure and body temperature were observed after injections of recombinant human interferon-alpha. 3. The excitation of the nerve activity induced by intra-ventricular recombinant human interferon-alpha was reversibly suppressed by an intravenous injection of an opioid antagonist, naloxone (1 mg/kg in 0.1 ml saline), whereas the injection of naloxone alone did not affect either the baseline level of the nerve activity or the systemic blood pressure. 4. The cytotoxicity of natural killer cells in the spleen measured by a standard chromium release assay was reduced 20 min after the laparotomy alone in anaesthetized rats. The reduced natural killer activity then recovered significantly when the splenic nerve was cut immediately after the laparotomy. When the peripheral cut end of the splenic nerve was subsequently stimulated (0.5 mA, 0.5 ms, 20 Hz for 20 min), a further suppression of natural killer cytotoxicity was observed. 5. The reduction of natural killer cytotoxicity produced by the stimulation of the splenic nerve was completely blocked by an intravenous injection of nadolol (a peripherally acting beta-adrenergic receptor antagonist), but not by that of prazosin (an alpha-antagonist). 6. These results indicate that a central injection of recombinant human interferon-alpha activates the splenic sympathetic nerve through brain opioid receptors and thereby suppresses the natural killer cytotoxicity by beta-adrenergic mechanisms.(ABSTRACT TRUNCATED AT 400 WORDS)

In vivo measurement of hypothalamic serotonin release by intracerebral microdialysis: significant enhancement by immobilization stress in rats.

Intracerebral microdialysis was used to measure extracellular serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the hypothalamus of unanesthetized rats. Increase in the concentration of K+ in the perfusing Ringer solution (70 mM) produced a sharp increase in serotonin release, which was significantly attenuated by omitting Ca2+ from the perfusion medium. Intraperitoneal injection of 5-hydroxytryptophan, a precursor of serotonin, or local perfusion of pargyline, a monoamine oxidase inhibitor, elevated the hypothalamic serotonin. Releasers or uptake inhibitors of serotonin, such as fenfluramine, cocaine, mazindol, or imipramine, when added to the perfusion medium, significantly increased serotonin level, whereas 5-HIAA was unaffected by these substances. Immobilization-stress caused an immediate increase in both the extracellular serotonin and 5-HIAA in the hypothalamus, suggesting that the hypothalamic serotonergic system is activated during immobilization stress. The present study indicates that the brain microdialysis is useful for analysis of local changes in serotonin concentration which directly reflect neuronal transmission.

Immune cytokines and regulation of body temperature, food intake and cellular immunity.

Interleukin-1 (IL-1) and interferon alpha (IFN alpha), cytokines originally detected in immunological cells, now have been shown to produce nonimmunological host defense responses of central and peripheral origins. These cytokines are released from glial cells in the brain in pathological states. Local application of IL-1 beta and IFN alpha to thermosensitive neurons in the preoptic and anterior hypothalamus and glucose responsive neurons in the ventromedial hypothalamus in vivo and in vitro, altered the activity in appropriate ways to explain the cytokines-induced fever and anorexia, respectively. The responses to IL-1 beta, but not to IFN alpha, were blocked by sodium salicylate, suggesting the involvement of synthesis of prostaglandins. alpha MSH, an endogenous antipyretic and a possible antagonist of IL-1 beta at lymphocytes, specifically depressed the responses to IL-1 beta, but not those to IFN alpha. In contrast, the action of IFN alpha was reversibly blocked by naloxone, suggesting the opioid receptor mediation. Intracerebral injection of IFN alpha and beta-endorphin in the rat and mouse resulted in the suppression of cytotoxic activity of natural killer cells in the spleen by activation of brain opioid receptor, which was shown to be mediated predominantly by splenic sympathetic nerves. The results suggest a view that immune cytokines may provide afferent links for the regulatory circuits between the brain and the immune system.

Central administration of interferon-alpha enhances rat sympathetic nerve activity to the spleen.

Intracerebroventricular injection of recombinant human interferon-alpha (IFN-alpha) in a dose of 1 x 10(4) U, but not 3 x 10(3) U, produced a long-lasting (at least for 60 min) increase (2.5-5 times the preinjection level) in the electrical activity of splenic sympathetic nerve filaments in urethane-alpha chloralose-anesthetized rats. Intravenous injection of IFN-alpha (3 x 10(4) U) also produced a similar excitation of splenic sympathetic nerves. There were no changes in arterial blood pressure and body temperature. The result, together with the previous findings, provides further evidence that the central IFN-alpha-induced suppression of cytotoxic activity of splenic natural killer cells may be mediated by the sympathetic innervation.

Hypothalamic microdialysis of mazindol causes anorexia with increase in synaptic serotonin in rats.

Brain microdialysis was used to determine if lateral hypothalamic serotonin (5-HT) is involved in the mazindol-induced anorexia in rats. Direct application of mazindol through a microdialysis membrane both significantly increased the 5-HT levels in the lateral hypothalamus and suppressed food intake by fasted rats. The increase in 5-HT concentration was dose related and the concentration of mazindol for half-maximal response was 4.6 microM. Pretreatment with methysergide, a potent 5-HT receptor-blocking agent, significantly antagonized the mazindol-induced anorexia. These results suggest that the anorectic action of mazindol might be mediated, at least in part, through serotonergic mechanisms in the hypothalamus.

A case of moyamoya disease with progressive involvement from unilateral to bilateral.

A case of Moyamoya disease in a child starting with unilateral lesion and developing into bilateral involvement is reported. Angiographic findings at onset showed unilateral involvement, hence, it was filed as a "probable" case according to the diagnostic criteria of the Japanese Cooperative Research Committee. The carotid angiograms, on the other side were totally normal. Three years later the occlusive lesion became bilateral, to meet the criteria as a "definite" case. Clinical manifestations, angiograms, electroencephalograms, and positron emission tomograms in this case are presented, and the relation between the probable and definite cases is discussed.