Assessment on interoceptive awareness on alcohol use and gambling disorders reveals dissociable interoceptive abilities linked to external and internal dependencies: Practical use of Body Perception Questionnaire Very Short Form (BPQ-VSF) in clinical settings

Interoception is one of the pivotal cognitive functions for mechanisms of our body awareness, and malfunction of the interoceptive network is thought to be associated with mental illness, including addiction. Within addictive disorders, substance-based and non-substance-based addictions are known to hold dissociable reward systems. However, little is known about how interoceptive awareness between these addiction sub-types would differ. Subjective interoceptive awareness was assessed among patients with alcohol use disorder (n = 50) who were subsequently hospitalized or remained out-patient and gambling addiction (n = 41) by the Body Awareness component of the Japanese version of the Body Perception Questionnaire (BPQ-VSFBA-J) and compared them against healthy control (n = 809). Both addiction groups showed significantly lower BPQ than the control, with no substantial differences between inpatients and outpatients for alcohol samples. Notably, BPQ scores for gambling patients were significantly lower than those for the alcohol group. This evidence may suggest a putative role of interoceptive ability on the severity of behavioral addiction over substance-based addiction.

A single site study to investigate the current prevalence of anti-hepatitis C virus antibody among substance use disorder patients in Hiroshima-Insufficient testing and diagnosis

AIMS

Hepatitis C virus (HCV) infection among drug users presents an important public health problem; however, little recognition and few approaches to address this issue in Japan. This study was conducted to investigate the current disease status by assessing anti-HCV antibody (Ab) seroprevalence among people who inject drugs (PWIDs) and people who use drugs (PWUDs) in Hiroshima, Japan.

METHODS

This study was a psychiatric single-site chart review in patients with drug abuse problems in the Hiroshima region. The primary outcome was anti-HCV Ab prevalence among PWIDs who underwent anti-HCV Ab testing. The secondary outcomes included the prevalence of anti-HCV Ab among PWUDs who underwent anti-HCV Ab testing and the proportion of patients who underwent anti-HCV Ab examination.

RESULTS

A total of 222 PWUD patients were enrolled. Among these, 16 patients (7.2%) had records of injection drug use (PWIDs). Eleven (68.8%) of the 16 PWIDs received anti-HCV Ab tests, and 4 (36.4%, 4/11) were anti-HCV Ab-positive. Among 222 PWUDs, 126 (56.8%) patients received anti-HCV Ab tests, and 57 of these patients (45.2%, 57/126) were anti-HCV Ab-positive.

CONCLUSION

The prevalence of anti-HCV Ab among PWIDs and PWUDs who visited the study site was higher than the general population, which was 2.2% among hospitalized patients between May 2018 and November 2019. Considering the World Health Organization's (WHO) elimination goal and recent advances in HCV treatment, patients with drug abuse experience should be encouraged to take HCV tests and consult hepatologists for further investigations and treatment if they are positive for anti-HCV Ab.

Risk factors for the onset of dependence and chronic psychosis due to cannabis use: Survey of patients with cannabis-related psychiatric disorders

AIM

The objective of the current study was to identify risk factors that affect the onset of dependence and chronic psychosis due to cannabis use.

METHODS

We examined clinical genetic factors, psychiatric disorders prior to cannabis use, starting age of cannabis use, duration and frequency of cannabis use, types of cannabis products used, combined use of other psychoactive substances, and the psychiatric diagnosis of 71 patients with cannabis-related psychiatric disorders who underwent treatment at nine mental health hospitals in Japan. Information was collected from cross-sectional interview surveys conducted by each patient's attending psychiatrist.

RESULTS

For the diagnosis of dependence syndrome due to the use of cannabis, we found associations with the number of years of cannabis use and the use of cannabis products with a high Δ9-tetrahydrocannabinol (THC) content. However, we found no association between diagnosis of residual and late-onset psychotic disorders and clinical genetic factors, presence of preceding psychiatric disorders, duration and frequency of cannabis use, starting age of cannabis use, or combined use of other psychoactive substances; an association was found only for the absence of use of cannabis products other than dried cannabis.

CONCLUSION

The onset of cannabis dependence was related to long-term cannabis use and the use of cannabis products with a high THC content. However, chronic psychosis was not associated with total THC intake or psychiatric vulnerability. Thus, unknown factors appear to be involved in the onset of chronic psychosis.

Predicting difficulty in extending the ileal pouch to the anus in restorative proctocolectomy: investigation of a simple predictive method using computed tomography

AIM

This study aimed to assess the ability of preoperative axial computed tomography (CT) to predict surgical difficulty in bringing the ileal pouch to the level of the anus during restorative proctocolectomy (RPC).

METHOD

Patients who underwent RPC with an ileal pouch-anal anastomosis (or ileal pouch-anal canal anastomosis) in our institution between January 2008 and April 2014 were enrolled. The patients were divided into two groups, including those in whom CT indicated potential difficulty in extending the pouch downwards (extension difficult (ED) group) and patients with no CT evidence of potential difficulty (normal group). The groups were compared for clinical factors and the thickness of the slices of CT showing the root of the superior mesenteric artery, the point of communication of the ileocaecal artery with the marginal artery (tICA) and the anal verge (AV). Receiver-operating characteristic analysis was performed, and a cut-off value was calculated for predicting the degree of difficulty in bringing the ileal pouch down to the anal canal.

RESULTS

Thirty-four patients were entered in the study. The ED group included significantly taller patients and more with familial adenomatous polyposis than the normal group. The distance between tICA and AV was significantly longer in the ED group, with a cut-off of 21 cm giving a sensitivity of 100% and a specificity of 83.3%.

CONCLUSION

The distance between tICA and AV measured by axial CT can be a useful predictor for the difficulty in bringing the ileal pouch down to the anus during RPC.

Three-step method for ultrasound-guided central vein catheterization

BACKGROUND

The long-axis view and in-plane needle approach (LAX-IP) for ultrasound-guided central vein catheterization is considered ideal because of the quality of real-time imaging. We describe a novel technique, using a step-by-step procedure, to overcome the pitfalls associated with the LAX-IP. This study was undertaken to demonstrate the clinical utility of this approach.

METHODS

All operators underwent training before participation in this study. One hundred patients were enrolled in this study and underwent central venous catheterization using this method. Using a portable ultrasound and vein catheterization kit, patients were appropriately positioned and a straight portion of the vein identified (Step 1). A needle guide was used (Step 2) and the vein imaged in real time in two directions (Step 3), to identify the true long axis and prevent damage to surrounding tissues.

RESULTS

The overall success rate for catheterization was 100% with a median of one puncture for each patient. All catheterizations were performed within three punctures. Problems with the first puncture included difficult insertion of the guide-wire due to coiling, difficult anterior wall puncture, less experience with the procedure, and other reasons. There were no complications associated with the procedure.

CONCLUSIONS

This three-step method is not dependent on an operator's ability to proceed based on spatial awareness, but rather depends on logic. This method can prevent difficulties associated with a two-dimensional ultrasound view, and may be a safer technique compared with others. Further clinical trials are needed to establish the safety of this technique.

Lack of association between suicidal ideation and enhanced platelet 5-HT2A receptor-mediated calcium mobilization in cancer patients with depression

BACKGROUND

Increased density of 5-HT2A receptors was observed in the platelets of depressive patients with suicidal ideation. Enhanced 5-HT2A receptor-mediated platelet calcium mobilization has been proposed as a biological marker for the pathophysiology of major depression in cancer patients as well as in physically healthy patients. To examine whether depressive cancer patients with suicidal ideation have enhanced 5-HT2A receptor-mediated platelet response compared with those without suicidal ideation, we compared 5-HT-induced platelet calcium mobilization in depressive cancer patients with and without suicidal ideation.

METHODS

5-HT-induced platelet calcium mobilization was examined in 24 cancer patients diagnosed as having major depression according to the DSM-IV criteria. Suicidal ideation was evaluated by the Hamilton Depression Rating Scale and Zung's Self Depression Scale, as well as by the DSM-IV criteria.

RESULTS

There was no significant differences in 5-HT-induced platelet calcium response between the depressive cancer patients with (n = 8) and without suicidal ideation (n = 16). 5-HT-induced platelet calcium response was also not significantly associated with the severity of suicidal ideation or with the severity of depression assessed by Hamilton Depression Rating Scale and Zung's Self Depression Scale.

CONCLUSIONS

These findings suggest that enhanced 5-HT2A receptor-mediated response was not associated with suicidal ideation in cancer patients with depression.

Meige syndrome with apraxia of lid opening after the discontinuation of sulpiride treatment

We report a case of Meige syndrome with apraxia of lid opening that lasted for about seven months after discontinuation of sulpiride treatment. To our knowledge, this is the first report demonstrating that Meige syndrome with apraxia of lid opening is induced by sulpiride, and that the condition persists.

The effects of antidepressant drug treatments on activator protein-1 binding activity in the rat brain

Since a long-term administration of antidepressant drugs and mood stabilizers is required in the treatment of mood disorders, the regulation of gene expression by these drugs that is mediated by transcription factors, such as activator protein-1 (AP-1) complex, may play an important role in the therapeutic action. In this study, the authors investigated the influence of lithium, antidepressant drugs and stress on AP-1 binding activity in the rat brain. In addition, we examined pretreatment with these drugs on the expression of AP-1 binding activity in response to stress. A gel shift assay was used to measure the levels of AP-1 binding activity. Our results indicate that neither acute nor chronic treatment with antidepressant drugs affects in AP-1 binding activity in the rat frontal cortex or hippocampus. However, the authors found that acute restraint stress for 90 min upregulated the induction of AP-1 binding activity in the rat frontal cortex. In addition, chronic pretreatment with imipramine, but not lithium or paroxetine, downregulated the induction of AP-1 binding activity in response to acute restraint stress in the frontal cortex. The functional classification of antidepressant drugs based on the downregulation of restraint stress-induced AP-1 binding activity may contribute to the advances in our understanding of the pathogenesis of depression.

Chronic lithium treatment increases the expression of brain-derived neurotrophic factor in the rat brain

RATIONALE

Lithium is the most widely prescribed mood stabilizer, but the precise mechanism of lithium is unresolved.

OBJECTIVE

We examine the effects of the administration of therapeutically relevant concentrations of lithium on the expression of brain-derived neurotrophic factor (BDNF) and its receptor, Trk B, as well as glia-derived neurotrophic factor (GDNF) and its receptors, RET and GDNFR-alpha, in the rat brain. In addition, we also examined the effect of another well-prescribed mood stabilizer, valproate, on the expression of BDNF and GDNF.

METHODS

Rats were kept on a 0.2% lithium carbonate-containing diet for 1, 7, 14, or 28 days or treated with valproate (400 mg/kg per day i.p.) for 1 or 14 days. After the brains were rapidly removed, the levels of BDNF, GDNF, and their receptors were measured by ELISA or western blot analysis.

RESULTS

Chronic lithium treatment for 14 and 28 days significantly increased the expression of BDNF in the hippocampus and temporal cortex. In addition, chronic lithium treatment for 14 days significantly increased the expression of BDNF in the frontal cortex. In contrast, acute or chronic dietary lithium treatment did not alter GDNF expression in these brain regions. In addition, acute or chronic lithium treatments did not change the levels of Trk B, RET, or GDNFR-alpha immunoreactivity. As well as lithium, repeated administration of valproate also increased the expression of BDNF in the frontal cortex and hippocampus.

CONCLUSIONS

Our results suggest that the chronic administration of mood stabilizers may produce a neurotrophic effect mediated by the upregulation of BDNF in the rat brain.

Characterization of 5-HT2A receptor desensitization and the effect of cycloheximide on it in C6 cells

Effect of prolonged pretreatment with serotonin (5-HT) on 5-HT2A receptor desensitization was examined by the measurement of intracellular calcium ([Ca2+]i) mobilization in C6 cells. 5-HT-induced desensitization of [Ca2+]i mobilization was in a time and dose dependent manner and reached a plateau after 3 hr. After 1 and 3 hr 5-HT pretreatment, 5-HT concentration in the medium little changed. 5-HT pretreatment with cycloheximide, a protein synthesis inhibitor, produced an enhancement of the desensitization for 3 and 6 hr pretreatment. However, 5-HT pretreatment for 3 and 6 hr caused no marked change in the 5-HT2A receptor mRNA level or Galphaq/11 protein in this study, suggesting that 5-HT may decrease 5-HT-induced [Ca2+]i mobilization independent of 5-HT2A receptor mRNA or G-proteins. Endothelin-1-induced [Ca2+]i mobilization did not alter after 5-HT and/or cycloheximide pretreatment. These results showed that activation of the 5-HT2A receptor induced homologous desensitization and pretreatment with 5-HT and/or cycloheximide did not change the efficacy of the second messenger pathway from Gq to a [Ca2+]i rise.

Modulation of serotonin2A receptor function in rats after repeated treatment with dexamethasone and L-type calcium channel antagonist nimodipine

1. It has been conceivable that the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity plays an important role in the pathophysiology of depression. In the present study, we have investigated the effect of repeated treatment with dexamethasone on serotonin (5-HT) 1A, 5-HT2A and alpha1-adrenergic receptors in the rat frontal cortex. Moreover, several studies have suggested the effectiveness of L-type calcium channel antagonist nimodipine for the treatment of depression. We also investigated the effect of repeated treatment with nimodipine on 5-HT2A receptor in rats with repeated dexamethasone treatment. 2. Repeated treatment with dexamethasone (1 mg/kg/day for 14 days) increased the density of 5-HT2A receptor, but not 5-HT1A and alpha1-adrenergic receptors in the rat frontal cortex. 3. The density of 5-HT2A receptor in the rat frontal cortex was significantly increased 1 day after repeated treatment with dexamethasone, but was not increased 7 or 14 days after repeated treatment. Wet dog shakes (WDS) induced by (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI), a 5-HT2A receptor agonist, in rats were significantly enhanced 1, 7 and 14 days after repeated treatment with dexamethasone, although the frequency of WDS gradually decreased after repeated treatment. 4. Repeated treatment with nimodipine (5 mg/kg/day for 14 days) attenuated DOI-induced WDS enhanced by repeated treatment with dexamethasone (1 mg/kg/day for 14 days), however, it did not change the density of 5-HT2A receptor. Repeated treatment with dexamethasone decreased locomotor activity and body weight, but repeated treatment with nimodipine did not recover these parameters. 5. The results of the present study suggest that repeated treatment with dexamethasone may selectively increase the 5-HT2A receptor in the rat frontal cortex and affect 5-HT2A receptor-mediated signal transduction. In addition, the intracellular calcium homeostasis by blocking calcium influx through L-type calcium channel may play an important role in the regulation of the 5-HT2A receptor function by dexamethasone.

Plasma concentrations of interleukin-1beta, interleukin-6, soluble interleukin-2 receptor and tumor necrosis factor alpha of depressed patients in Japan

There are a number of investigations which indicate the important relationship between depression and cytokines. In this study, we investigated plasma interleukin (IL)-1beta, IL-6, soluble IL-2 receptor (sIL-2R) and tumor necrosis factor (TNF)-alpha of depressed patients whose clinical evaluation was performed by the Hamilton Rating Scale for Depression (HAM-D) and the Profile of Mood States (POMS). They were compared with those of the control subjects, and before and after treatment with antidepressants. Before the treatment, plasma IL-1beta, IL-6, sIL-2R and TNF-alpha of the patients were not significantly different from those of the control subjects. sIL-2R was positively correlated with the POMS-tension-anxiety subscale and tended to have a positive correlation with HAM-D. After pharmacotherapy, TNF-alpha levels of the depressed patients increased, without any relationship between the change in the HAM-D or the POMS and the change in TNF-alpha. These results suggest that the plasma sIL-2R concentration is associated with mood state, and that the plasma TNF-alpha concentration is increased after pharmacotherapy in Japanese depressed patients.

Calf and shin muscle oxygenation patterns and femoral artery blood flow during dynamic plantar flexion exercise in humans

The effects of dynamic plantar flexion exercise [40, 60, and 80 contractions.min-1 (cpm)] on calf and shin muscle oxygenation patterns and common femoral artery blood flow (Qfa) were examined in six female subjects [mean age 21 (SD 1) years] who exercised for 1 min at 33% of their maximal voluntary contraction at ankle angles between 90 degrees and 100 degrees. Spatially resolved near-infrared spectroscopy was used to measure medial gastrocnemius, lateral soleus (synergist) and anterior tibialis (antagonist) muscle oxygen saturation (SO2, %). Qfa was measured by ultrasound Doppler. The SO2 changed significantly only in the medial gastrocnemius and its decrease (up to about 30%) was independent of the contraction frequencies examined. The increase in Qfa, at the end of exercise, was highest at 80 cpm. When the exercise at 60 cpm was prolonged until exhaustion [mean 2.7 (SD 1.1) min], medial gastrocnemius SO2 decreased, reaching its minimal value [mean 30 (SD 10)%] within the 1st min, and had partially recovered before the end of the exercise with concomitant increases in total haemoglobin content and Qfa. These results suggest that the medial gastrocnemius is the muscle mostly involved in dynamic plantar flexion exercise and its oxygen demand with increases in contraction frequency and duration is associated with an up-stream increase in Qfa.

Effect of beta-estradiol on voltage-gated Ca(2+) channels in rat hippocampal neurons: a comparison with dehydroepiandrosterone

We investigated the effects of beta-estradiol, dehydroepiandrosterone and dehydroepiandrosterone sulfate on intracellular calcium concentration ([Ca(2+)](i)) increases induced by gamma-aminobutyric acid (GABA), high K(+) and N-methyl-D-aspartate acid (NMDA) in cultured hippocampal neurons. Acute treatment with beta-estradiol, dehydroepiandrosterone and dehydroepiandrosterone sulfate inhibited the GABA-induced [Ca(2+)](i) increases to the similar extent. Tamoxifen, an estrogen receptor antagonist, did not block the inhibitory effects of beta-estradiol. On the other hand, GABA type A (GABA(A)) receptor antagonists, picrotoxin and bicuculline, blocked the GABA-induced [Ca(2+)](i) increases. Previously, we demonstrated that GABA- and high K(+)-induced [Ca(2+)](i) increases were commonly mediated by voltage-gated calcium channels (VGCCs). Therefore, we examined the effects of these steroids on the high K(+)-induced [Ca(2+)](i) increases. The inhibitory effect of beta-estradiol on the high K(+)-induced [Ca(2+)](i) increases was much greater than that of dehydroepiandrosterone and dehydroepiandrosterone sulfate. beta-Estradiol inhibited the NMDA-induced [Ca(2+)](i) increases with an IC(50) of 51.8 microM and NMDA responses were reduced to half in the presence of 10 micro M nifedipine, indicating that the NMDA-induced [Ca(2+)](i) increases also involved VGCCs. Further, we examined the inhibitory effect of beta-estradiol on the high K(+)-induced [Ca(2+)](i) increases in the presence of a N-type VGCCs antagonist, 1 microM omega-conotoxin, or a L-type VGCCs antagonist, 10 microM nifedipine. The IC(50) value of beta-estradiol alone (45.5 microM) was similar to that of omega-conotoxin (33.1 microM), while the value combined with nifedipine was reduced to 2.2 microM. beta-Estradiol also abolished the positive modulatory effect of L-type VGCCs agonist, 1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]pyridine-3-carboxylic acid methyl ester (Bay K 8644). Our results showed that the inhibitory mechanism of beta-estradiol is different from that of dehydroepiandrosterone and dehydroepiandrosterone sulfate and beta-estradiol may act primarily at L-type VGCCs.

Effect of heat stress on serotonin-2A receptor-mediated intracellular calcium mobilization in rat C6 glioma cells

This study was conducted to investigate an effect of heat stress at 44 degrees C for 30 min on intracellular Ca2+ signaling system and on heat shock protein (HSP)-70 expression. 5-HT-induced Ca2+ mobilization was reduced 1, 3 and 6 hrs after heat stress, and recovered to the control level 12 and 24 hrs after heat stress. One hr after heat stress, Ca2+ rise was significantly decreased when the cells were stimulated by any concentration of 5-HT. Thrombin-induced Ca2+ increase was also markedly reduced 1 hr after heat stress. HSP-70 level was increased 6 and 9 hr after heat stress. In HSP synthesis inhibitor quercetin-treated cells, HSP-70 expression was not enhanced after heat stress, and Ca2+ rise in response to 5-HT did not return to the control level. However, the Ca2+ rise induced by 5-HT was not restored to the control level after stress in Ac-Asp-Glu-Val-Asp-H (DEVD)-exposed cells while DEVD had little effect on heat stress-induced synthesis of HSP-70. Dexamethasone did not alter the change in HSP-70 expression or Ca2+ response after heat stress. These results indicate that heat stress attenuated 5-HT-induced Ca2+ mobilization and that HSP-70 expression played an important role in recovery from Ca2+ impairment, possibly via protease activity in C6 cells.

Effects of antidepressants on gamma-aminobutyric acid- and N-methyl-D-aspartate-induced intracellular Ca(2+) concentration increases in primary cultured rat cortical neurons

We investigated the effects of antidepressants on the intracellular Ca2+ concentration ([Ca2+]i) increases induced by gamma-aminobutyric acid (GABA) or N-methyl-D-aspartate (NMDA) in primary cultured rat cortical neurons using fluorescence imaging. Acute treatment with imipramine inhibited GABA- and NMDA-induced increases in [Ca2+]i in a concentration-dependent manner. Doses of 30 microM clomipramine, desipramine, amoxapine and maprotiline also inhibited both the GABA- and NMDA-induced [Ca2+]i increases significantly. Both inhibitory effects of the five major antidepressants on the GABA- or the NMDA-induced [Ca2+]i increases were well-correlated. Imipramine could inhibit significantly high-K+-induced [Ca2+]i increases. Our previous study has already shown that the GABA-induced [Ca2+]i increase involves a similar pathway to high-K+-induced Ca2+ influx. In conclusion, imipramine and several other antidepressants have acute inhibitory effects on the GABA-, NMDA- and high-K+-induced [Ca2+]i increases, suggesting that these inhibitory effects are not related to specific receptors. One possibility is that these effects may be commonly mediated via part of the high-K+-induced [Ca2+]i pathway.

Effect of acute lipopolysaccharide administration on (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2 aminopropane-induced wet dog shake behavior in rats: comparison with body weight change and locomotor activity

1. Several reports have shown that serotonin (5-HT)2A receptor density and its function are altered after physiological or pharmacological stress. To examine whether an acute administration of lipopolysaccharide (LPS), a bacterial endotoxin, affected 5-HT2A receptor function, wet dog shakes of male Wistar rats were observed after a subcutaneous injection of DOI, a 5-HT2A receptor agonist following LPS treatment. Body weight change and locomotor activity were also observed. 2. DOI (1 mg/kg)-induced WDS significantly decreased after 400 or 1000 microg/kg LPS treatment compared with that of control rats 1 and 3 hr after injection, and WDS completely recovered 8 hr after LPS treatment. Treatment with 10 mg/kg indomethacin (IND) or 1 mg/kg naltrexone (NLTX) canceled the effect of 400 microg/kg LPS on DOI-induced WDS. 3. Body weight decrease was significantly greater in LPS-treated rats compared with control rats 3, 5 and 8 hr after treatment. Treatment with IND (10 mg/kg) significantly recovered the reduction in body weight induced by 400 microg/kg LPS. Treatment with NLTX (1 mg/kg) also prevented the LPS effect on body weight decrease. 4. Eight hr after treatment with LPS (400 microg/kg), the rats showed significant attenuation of locomotor activity. IND (10 mg/kg) treatment abolished the inhibitory effect of LPS on locomotor activity, and NLTX (1 mg/kg) also improved the decrease in locomotion 8 hr after LPS treatment. 5. Plasma tumor necrosis factor (TNF)-alpha concentration dramatically increased 1 hr after the injection of 400 microg/kg LPS, and returned almost to the basal level 3 hr later. Next, rats were injected with 50 microg/kg TNF-alpha intraperitoneally, and body weight change and DOI-induced WDS was determined 3 hr after TNF-alpha injection. Body weight loss was significantly greater in rats treated with TNF-alpha. On the other hand, DOI-induced WDS was not altered when rats were treated with TNF-alpha. 6. These results suggest that acute treatment with LPS inhibited 5-HT2A receptor-mediated behavior via cyclooxygenase and opioid receptor activation, but that the inhibition of the WDS by LPS appears to be independent of TNF-alpha production.

Three sets of diagnostic criteria for major depression and correlations with serotonin-induced platelet calcium mobilization in cancer patients

OBJECTIVE

Enhanced serotonin-induced platelet calcium mobilization has been proposed to be a biological marker for the pathophysiology of major depression in physically healthy patients. To determine the most appropriate method of diagnosing major depression in cancer patients, we compared serotonin-induced platelet calcium mobilization between patients with and without major depression diagnosed according to three different sets of diagnostic criteria (inclusive, substitutive and exclusive).

METHODS

Among the cancer patients referred to our institution between June 1997 and March 1998, 24 patients diagnosed as having major depression according to the inclusive approach (in which the nine traditional symptoms of major depression contribute towards the diagnosis of depression regardless of its presumed etiology) participated in the study. Serotonininduced platelet calcium mobilization was examined in these patients and in the same number of non-depressed controls matched for age, sex, cancer stage and cancer site. The depressed patients were then re-evaluated using substitutive and exclusive criteria, and calcium mobilization comparisons with the relevant controls were repeated.

RESULTS

Compared with the controls, an enhanced serotonin-induced platelet calcium response was only observed in the patients with major depression according to the exclusive criteria. No significant enhancement was observed when the inclusive or substitutive approaches were used.

CONCLUSION

These findings, based on the use of enhanced serotonin-induced platelet calcium mobilization as a biological marker, suggest that the exclusive approach might be the most valid and appropriate method of diagnosing major depression in cancer patients, while the inclusive and substitutive approaches might overestimate the occurrence of major depression in these patients.

Chronic electroconvulsive shock decreases (+/-) 1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI)-induced wet-dog shake behaviors of dexamethasone-treated rats

Electroconvulsive shock (ECS) therapy is considered to be an effective treatment for depression, but its mechanism of action is still unknown. We investigated the effect of chronic ECS in rats treated for 14 days with dexamethasone (Dex), a glucocorticoid receptor agonist. Chronic injection of sesame oil decreased body weight change and increased serotonin (5-HT)-2A receptor number and DOI (5-HT-2A, 2C receptor agonist)-induced wet-dog shake (WDS) behaviors. Dex treatment for 14 days decreased body weight of rats, but repeated ECS did not reverse this decrease. Dex also abolished plasma corticosterone levels, and ECS failed to restore these levels. These results indicate that chronic ECS does not antagonize the effect of Dex. The treatment with Dex increased 5-HT-2A receptor binding density of rat frontal cortex and the number of DOI-induced WDS behaviors. Chronic ECS reduced the enhanced WDS behaviors by Dex but had little effect on receptor density. These results suggest that chronic ECS might suppress 5-HT-2A receptor function at the postreceptor signaling level rather than at the receptor itself, without changing HPA axis function in Dex-treated rats.

Effect of lithium carbonate on the enhancement of serotonin 2A receptor elicited by dexamethasone

The purpose of this study was to investigate whether chronic dexamethasone (Dex) administration induces serotonin (5-HT) 2A receptor supersensitivity and if chronic lithium carbonate (Li) administration contributes to the normalization of 5-HT2A receptor supersensitivity induced by Dex in rat brain. We investigated the effects of a 14-day administration of Dex and/or Li on changes in body weight (BW), on plasma corticosterone levels, on plasma lithium levels, on 5-HT2A receptor binding sites, and on (+/-)-1-(2, 5-dimethoxy-4-iodophenyl)-2 aminopropane (DOI)-induced wet dog shake (WDS), which is mediated by 5-HT2A receptor in rats. Dex significantly reduced the BW of rats. Li did not have any effect on BW gain and did not prevent the BW loss induced by Dex. The plasma corticosterone levels of rats treated with Dex were too low to be detected. Li did not have any effect on corticosterone levels and did not prevent the decrease in the corticosterone levels induced by Dex. Six hours after the last treatment, the plasma lithium levels of rats treated with Li were significantly higher than those of rats treated with Dex/Li. Chronic Dex administration resulted in a significant increase in the density (B(max)) of the 5-HT2A receptor without a significant change in the affinity (K(d)). The increase in the B(max) induced by Dex was not prevented by chronic combined treatment with Dex and Li. Chronic Dex administration potentiated the WDS, and this increase was prevented by chronic combined treatment with Dex and Li. Chronic Li administration did not have any effect on WDS. These results indicate that chronic Li administration may improve the supersensitivity of the 5-HT2A receptor elicited by chronic Dex administration without decreasing the density of the 5-HT2A receptor, and the effect of Li was also independent of hypothalamo-pituitary-adrenal axis function.

Oxygen supply-consumption balance in the thigh muscles during exhausting knee-extension exercise

The purpose of this study was to investigate the difference in muscle oxygenation between the individual muscles involved in an exhaustive knee-extension exercise. Eight active women performed exercise by extending the knee joint from 90 degrees to 30 degrees (60 extensions min-1) at 20%, 30%, and 40% maximum voluntary contraction (MVC). Changes in oxy-(delta HbO2), deoxy-(delta Hb), and total (delta HbT) hemoglobin concentrations, and oxygen saturation (delta SO2NIRS = HbO2/HbT) in the vastus lateralis (VL) and rectus femoris (RF) muscles were measured with a spatially resolved near-infrared spectrometer (NIRS). The delta SO2NIRS in the VL and RF decreased rapidly from the pre-exercise control value (VL: 75.6 +/- 0.9%; RF: 81.6 +/- 1.6%) at the onset of exercise at three different intensities, although no significant difference in delta SO2NIRS was found between the two muscles at this time. However, the delta SO2NIRS decreased more rapidly thereafter and reached a lower value at exhaustion in the VL than in the RF. The difference in delta SO2NIRS between the VL (-10.3 +/- 1.7%) and RF (-4.0 +/- 1.0%) was significant (p < 0.05) when exercise intensity was 30% MVC. When the decreases in delta HbO2 and delta HbT (p < 0.05) were compared at different exercise intensities, the values at 30% and 40% MVC were significantly lower (delta HbO2: p < 0.01; delta HbT: p < 0.05) than those at 20% MVC in the VL, but there was no significant difference in any of the parameters in the RF, or in delta Hb in the VL. These results suggest that the muscle oxidative response to exhaustive knee-extension exercise differed between the VL and RF muscles. At exhaustion, oxygen saturation decreased to a lower level in the VL than in the RF, and an intensity-dependent difference in muscle oxygenation parameters was observed at 30% MVC in the VL but not in the RF muscles.

Neurotrophic action of interleukin 3 and granulocyte-macrophage colony-stimulating factor on murine sympathetic neurons

We investigated neurotrophic effects of interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on cultured sympathetic neurons obtained from mouse superior cervical ganglia. After 1 day of culture with physiological concentrations of mouse recombinant IL-3 and GM-CSF, the numbers of process-bearing neurons were increased. Maximum responses were elicited by 10 U/ml IL-3 and 1 U/ml GM-CSF, which were equivalent to the action of a submaximal dose (5 ng/ml) of nerve growth factor (NGF). The effects of IL-3 and GM-CSF were completely blocked by their corresponding antibodies, but not by anti-NGF, indicting their action is specific and completely independent of NGF. IL-3 and, to a lesser extent, GM-CSF were also able to protect NGF-differentiated neurons from apoptotic cell death caused by NGF withdrawal. The mitogen-activated protein (MAP) kinase signal transduction pathway is known to be involved in action of IL-3 and GM-CSF on hemopoietic cells, and thus we examined the participation of this pathway in the neurotrophic activities of IL-3 and GM-CSF. IL-3 and GM-CSF stimulation of the differentiated neurons was found to result in a rapid elevation of MAP kinase activity, and PD98059, an inhibitor of MAP kinase kinase activity, blocked both the neuritogenic and neuroprotective effects of IL-3 and GM-CSF. Immunocytochemical studies showed that IL-3 and GM-CSF receptors were present on the differentiated neurons. Thus, IL-3 and GM-CSF appear to be able to stimulate sympathetic nerve growth, via specific cytokine receptors on neurons, which lead to activation of the MAP kinase pathway that then mediates the observed neurotrophic effects.

Risperidone treatment of neuroleptic-induced tardive extrapyramidal symptoms

Tardive extrapyramidal symptoms (EPS) induced by neuroleptic treatment, and particularly EPS which persist after withdrawal of the drugs, are clinically serious problems. We describe a patient with four types of tardive and persistent EPS such as dystonia, dyskinesia, choreatic movement and myoclonus, induced by haloperidol. These EPS were remarkably inhibited by 3 mg/day risperidone. This is the first published case demonstrating simultaneous development of these four types of tardive EPS induced by a neuroleptic and then reduced by low-dose risperidone treatment. ( Int J Psych Clin Pract 2000; 4: 241 - 243).

Lithium chloride inhibits thrombin-induced intracellular calcium mobilization in C6 rat glioma cells

In this study, the authors have demonstrated the effect of lithium, a typical mood stabilizer, on thrombin-evoked Ca2+ mobilization in C6 cells to elucidate the action mechanisms of the drug. Thrombin-induced Ca2 mobilization was reduced 24 hr after 1 or 10 mM lithium chloride (LiCl) pretreatment. The Ca2+ rise was reduced in a time-dependent manner, and the significant inhibition was observed 9 hr pretreatment with 10 mM LiCl. On the other hand, pretreatment of the cells with 10 mM LiCl for 24 hr did not alter the amount of Galphaq/11 significantly. Pretreatment with 10 mM LiCl for 24 hr failed to reduce the 5-HT-induced Ca2+ mobilization or to affect the desensitization of the 5-HT signal. Finally, thrombin-elicited Ca2+ rise was markedly inhibited in the presence of 0.05 U/ml plasmin, however, the Ca2+ rise was not further attenuated in the presence of plasmin in C6 cells pretreated with LiCl for 24 hr. These results indicate that pretreatment with LiCl attenuated thrombin-evoked intracellular Ca2+ mobilization in plasmin sensitive manner in C6 rat glioma cells. Thus, it is important to investigate the effect of lithium on thrombin-induced cellular responses to clarify the action mechanism of lithium in relation to some abnormality in thrombin-evoked Ca2+ rise observed in bipolar disorders.

Lithium and clonazepam treatment of two cases with cluster headache

Patients with cluster headache are often treated with lithium. However, there are some patients who can not be fully treated with lithium alone. Two patients with cluster headache were treated with clonazepam, one of the most potent benzodiazepines. Lithium prolonged the period of remission, and the addition of clonazepam further prolonged it in case 1. Treatment with clonazepam reduced the symptoms in case 2, and when combined with lithium, the disorder went into remission after 6 months. These findings suggest that the combination of lithium and clonazepam may be effective in patients with cluster headache.

[Frequent convulsions in the post-eruptive stage of exanthem subitum]

We report here three infants with frequent convulsions in the post-eruptive stage of exanthem subitum (ES) due to human herpesvirus 6 (HHV-6) infection. Postictal electroencephalogram (EEG) showed in all the patients abnormal epileptic discharges, which disappeared in the following by three to eighteen months. In one case, brain magnetic resonance imaging (MRI) revealed focal gliosis. SPECT demonstrated hypoperfusion of the lesion. In the cerebro spinal fluid (CSF) of all the patients, HHV-6 DNA was negative on polymerase chain reaction (PCR) and HHV-6 antibodies were not significantly increased. Although encephalitis has been reported to complicate primary HHV-6 infection, our patients were not diagnosed as having encephalitis because of the clinical, CSF, EEG and CT findings. However, they had frequent convulsions. Not only virus invasion but also a secondary reaction including vasculitis may cause the central nervous system complications of HHV-6 infection. Frequent convulsions may occur in the post-eruptic stage after HHV-6 infection.

Effect of acute and chronic administration of dehydroepiandrosterone on (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane-induced wet dog shaking behavior in rats

It has been reported that dehydroepiandrosterone (DHEA) or dehydroepiandrosterone sulfate (DHEA-S) is associated with affective disorders and that pathology of affective disorders are related with dysfunction of serotonin(5-HT)-2A receptor-mediated responses. In this study, we investigated the effect of DHEA on (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2 aminopropane (DOI), 5-HT-2A receptor agonist, -induced wet dog shaking behavior (WDS) in rats. Acute treatment with DHEA inhibited the DOI-induced WDSs dose dependently. This inhibition was recovered by opioid receptor antagonist, naltrexone. 5-HT-2A receptor-mediated WDSs were desensitized after chronic treatment with DOI, however chronic treatment with DHEA had no effect on this desensitization. Chronic treatment with DHEA had no facilitating effect of chronic dexamethasone treatment on DOI-induced WDSs. These findings may lead the possibility that DHEA has the inhibitory effect of 5-HT-2A mediated signaling pathway via non-genomic action.

The relationship of the platelet 5-HT-induced calcium response to clinical symptoms in eating disorders

Clinical observations indicate that persons with eating disorders exhibit many psychopathologic symptoms such as difficulty with impulse control and depressed mood associated with impaired regulation of serotonin (5-HT) synaptic function in the central nervous system. In this study, we focused on the relationship between the 5-HT-induced calcium response in platelets and the clinical symptoms. While age, body weight, and severity of depressive symptoms were not correlated with 5-HT-induced response, there was an enhanced response in patients with bulimic symptoms or other impulsive behaviors. Moreover, patients with multi-impulsive behaviors had a significantly higher maximal increase than patients with uni-impulsive behavior, i.e., those who had only bulimic symptoms, as well as non-impulsive patients, and controls. Considering these results, the 5-HT-induced response may be related to difficulty with impulse control in general rather than bulimic eating attitudes specifically.

Antipsychotic-induced life-threatening 'esophageal dyskinesia'

We report two patients with lingual dyskinesia and complaints of food regurgitation following long-term antipsychotic therapy. Esophageal contrast radiography revealed dyskinetic movements extending from the pharynx to the upper portion of the esophagus. The elevation of intraesophageal pressure was confirmed by esophageal manometry. The dyskinetic movements almost disappeared along with improvement of lingual dyskinesia following the administration of sulpiride in one patient. Another patient suddenly died due to asphyxiation of foods before the beginning of treatment. We termed this life-threatening movement, 'esophageal dyskinesia'. It should be emphasized that 'esophageal dyskinesia' associated with lingual dyskinesia is a potentially fatal adverse reaction to antipsychotic therapy.

Neuroleptics with differential affinities at dopamine D2 receptors and sigma receptors affect differently the N-methyl-D-aspartate-induced increase in intracellular calcium concentration: involvement of protein kinase

This study examined the effect of chronic antipsychotic treatment on the NMDA-elicited changes in intracellular free Ca2+ concentration ([Ca2+]i) in the primary culture of rat frontal cortical neurons. Antipsychotics used in the study were chosen for their differential affinities at dopamine D2 receptors and sigma receptors. The potential involvement of protein kinases in this action of antipsychotics were also examined. Chronic treatment of cells with antipsychotics (sulpiride, clozapine, and chlorpromazine) which are known to be potent dopamine D2 receptor ligands, whereas possessing low or no appreciable affinity for sigma receptors, caused a dose-dependent potentiation of the NMDA-induced increase in [Ca2+]i. On the contrary, haloperidol, which is as potent a sigma receptor ligand as a dopamine D2 receptor ligand, did not affect the NMDA-elicited increase in [Ca2+]i. Sulpiride increased the maximum effect afforded by different concentrations of NMDA and shifted the dose-response curve of NMDA to the left (EC50 value from 12.5 microM to 1.39 microM). Consistent with sulpiride's affinity at dopamine D2 receptors, this action of sulpiride was stereoselective: S(-)-sulpiride was active whereas R(+)-sulpiride was inactive. Treatment of cells with dopamine (3 microM) tends to decrease the NMDA-induced increase in [Ca2+]i. Sulpiride at 1 microM totally abolished this action of dopamine and restored its potentiating action on the NMDA-induced increase in [Ca2+]i. Haloperidol, a potent dopamine D2 and sigma receptor ligand, did not affect the sulpiride's potentiating action on the NMDA-induced responses. On the other hand, chronic treatment of cells with a sigma receptor agonist, DTG, at a concentration producing no effect of its own (10 nM), led to an enhancement of the potentiating effect of sulpiride on NMDA-induced increase in [Ca2+]i. This action of DTG was abolished by haloperidol. Further, chronic, but not acute, treatment of cells with either a protein kinase inhibitor H-7 or a cAMP-dependent protein kinase (PKA) inhibitor H-89 abolished this effect of sulpiride on the NMDA-induced [Ca2+]i changes. These results indicate that the action of NMDA in the primary cortical neurons are regulated differently by ligands with differential affinities at dopamine D2 and sigma receptors. The results with protein kinase inhibitors indicate that the potentiation of NMDA responses by sulpiride involves intracellular biochemical events.

Nocturnal eating/drinking syndrome and neuroleptic-induced restless legs syndrome

Nocturnal eating/drinking syndrome secondary to neuroleptic-induced restless legs syndrome (RLS) occurred under treatment with low-dose haloperidol in a 51-year-old female schizophrenic patient. Polysomnographic investigation showed a low level of sleep efficacy, periodic leg movements, and a strict relationship between nocturnal eating episodes and non-rapid eye movement sleep. Her nocturnal eating and RLS were completely inhibited by clonazepam treatment. To our knowledge, this is the first published case of nocturnal eating/drinking syndrome secondary to neuroleptic-induced RLS.

Plasma dehydroepiandrosterone sulfate in unipolar major depression. Short communication

We investigated plasma dehydroepiandrosterone sulfate (DHEAS) and cortisol levels in 12 patients with unipolar depression and 11 matched normal controls. The depressed patients showed significantly higher values of plasma DHEAS and cortisol than the controls. After 4 weeks of treatment with antidepressants (mainly clomiplamine), the high plasma DHEAS levels recovered. This finding showed the possible relationship between plasma DHEAS levels and depression, as well as cortisol levels.

Effects of carbon monoxide exposure on serotonergic neuronal systems in rat brain

It is well known that some psychiatric sequelae exist after CO poisoning, but few animal studies on serotonergic neuronal function after CO exposure have been carried out. We investigated the effects of successive carbon monoxide (CO) exposure (6000 ppm, 10 min, 3 repetitions) on serotonergic neuronal systems in rat brain. Serotonin (5-HT) concentrations were significantly decreased only in the frontal cortex from 1 hr to 7 days after CO exposure. 5-Hydroxyindoleacetic acid (5-HIAA) concentrations were significantly increased at 1 hr in all six brain regions measured (frontal cortex, striatum, hypothalamus, hippocampus, midbrain, and pons). 5-HT synthesis, measured by the accumulation of 5-hydroxytryptophan (5-HTP) after the administration of m-hydroxybenzylhydrazine (NSD-1015), was significantly decreased in all regions from 1 hr to 7 days after CO exposure. [3H]Ketanserin (5-HT2A) binding sites in the frontal cortex were not affected by CO exposure. DOI-induced head shakes, a 5-HT2A receptor mediated behavior, were not changed after CO exposure. These findings indicated that CO exposure caused presynaptic serotonergic neuronal dysfunctions that consisted mainly of decreased concentration of 5-HT in the frontal cortex or a decrease of 5-HT synthesis in all six regions, without compensatory hyperfunction of 5-HT2A receptors.

Positive influence of a liaison program on the rate of psychiatric consultation referrals for cancer patients

To improve access to psychiatric consultation for cancer patients as well as non-cancer patients with psychiatric disorders, a psychiatric liaison programme to communicate closely with physicians and ward staff regarding anticipated psychiatric morbidity in patients, was introduced in each ward of a general hospital. The rate of psychiatric consultation referrals for cancer patients was significantly higher after the psychiatric liaison programme was established. The programme had a greater impact on the rate of psychiatric consultation in a unit with cancer patients who were informed of their diagnoses. The greater consultation rates in cancer patients after the liaison programme might be, in part, associated with the physicians' attitude toward the more open disclosure of the cancer diagnosis.

Intracellular calcium signaling systems in the pathophysiology of affective disorders

In this paper, we show the importance of intracellular calcium (Ca2+) signaling systems in the pathophysiology of mood disorders based on our recent work. Patients with affective disorders appear to have an enhanced intracellular Ca2+ rise in response to serotonin. We have observed effects of antidepressant drugs on intracellular Ca2+ signaling in rat cultured neuronal cells and glioma cells, and found that acute application of several classes of antidepressant drugs inhibited intracellular Ca2+ signaling and Ca2+-related signaling. It is important to investigate the role of intracellular Ca2+ signaling system for an understanding of the pathophysiology of affective disorders.

Lipopolysaccharide regulates both serotonin- and thrombin-induced intracellular calcium mobilization in rat C6 glioma cells: possible involvement of nitric oxide synthase-mediated pathway

To investigate the mechanisms by which lipopolysaccharide (LPS) affects Ca2+ signaling systems, we studied the effects of LPS on the serotonin (5-HT)- or thrombin-induced intracellular Ca2+ ([Ca2+]i) increase in rat C6 glioma cells. Pretreatment of the cells with 1 microg/ml LPS for 24 hr significantly inhibited [Ca2+]i increase induced by 10 microM 5-HT- or 0.5 U/ml thrombin. Its inhibitory effects were both dose- and time-dependent. Treatment with 1 mM dibutyryl cGMP (dbcGMP) for 30 min also significantly inhibited the 5-HT- and thrombin-induced [Ca2+]i increase to approximately 60-70% of control. However, simultaneous pretreatment with LPS and dbcGMP did not show any synergistic inhibition. The simultaneous pretreatment with LPS and the potent cGMP-dependent protein kinase (PKG) inhibitors H-8 and KT5823 for 24 hr significantly antagonized the inhibitory effect of LPS. Pretreatment of the cells with 1 microg/ml LPS for 24 hr significantly enhanced cGMP accumulation, while dexamethasone and NMMA (NOS inhibitors) significantly attenuated the LPS-induced enhancement in cGMP accumulation. In addition, pretreatment of the cells with 100 nM dexamethasone for 24 hr significantly suppressed LPS-induced inducible nitric oxide synthase (iNOS; type II NOS, NOS-II) protein expression. These results indicate that LPS may inhibit both 5-HT- and thrombin-induced [Ca2+]i increase via iNOS expression and PKG activation pathway in rat C6 glioma cells.

Effect of dantrolene on KCl- or NMDA-induced intracellular Ca2+ changes and spontaneous Ca2+ oscillation in cultured rat frontal cortical neurons

Dantrolene has been known to affect intracellular Ca2+ concentration ([Ca2+]i) by inhibiting Ca2+ release from intracellular stores in cultured neurons. We were interested in examining this property of dantrolene in influencing the [Ca2+]i affected by the NMDA receptor ligands, KCl, L-type Ca2+ channel blocker nifedipine, and two other intracellular Ca2(+)-mobilizing agents caffeine and bradykinin. Effect of dantrolene on the spontaneous oscillation of [Ca2+]i was also examined. Dantrolene in microM concentrations dose-dependently inhibited the increase in [Ca2+]i elicited by NMDA and KCl. AP-5, MK-801 (NMDA antagonists), and nifedipine respectively reduced the NMDA and KCl-induced increase in [Ca2+]i. Dantrolene, added to the buffer solution together with the antagonists or nifedipine, caused a further reduction in [Ca2+]i to a degree similar to that seen with dantrolene alone inhibiting the increase in [Ca2+]i caused by NMDA or KCl. At 30 microM, dantrolene partially inhibited caffeine-induced increase in [Ca2+]i whereas it has no effect on the bradykinin-induced change in [Ca2+]i. The spontaneous oscillation of [Ca2+]i in frontal cortical neurons was reduced both in amplitude and in base line concentration in the presence of 10 microM dantrolene. Our results indicate that dantrolene's mobilizing effects on intracellular Ca2+ stores operate independently from the influxed Ca2+ and that a component of the apparent increase in [Ca2+]i elicited by NMDA or KCl represents a dantrolene-sensitive Ca2+ release from intracellular stores. Results also suggest that dantrolene does not affect the IP3-gated release of intracellular Ca2+ and that the spontaneous Ca2+ oscillation is, at least partially, under the control of Ca2+ mobilization from internal stores.

Effect of dantrolene on K(+)- and caffeine-induced dopamine release in rat striatum assessed by in vivo microdialysis

Recently, dantrolene has been reported to affect the central nervous system in addition to peripheral targets such as skeletal muscle. We examined effects of dantrolene on K(+)- and caffeine-induced dopamine release in rat striatum using in vivo microdialysis. Perfusion with KCl via the dialysis probe for 20 min induced immediate increase in DA release. Either chelation of extracellular calcium or addition of dantrolene for 120 min preceded reapplication of 100 mM KCl for 20 min. Calcium chelation attenuated the increase in DA release induced by KCl. Application of dantrolene enhanced the KCl-induced increase in DA release, but this effect disappeared at 100 microM. Caffeine caused a dose-dependent increase in dopamine release, independently of extracellular calcium. Treatment with 100 microM dantrolene for 120 min reduced the increase in DA release induced by caffeine. These findings that dantrolene modulates dopamine release in rat striatum indicate that conventionally administered dantrolene is likely to act on the central nervous system.

Differential regulation by pregnenolone sulfate of intracellular Ca2+ increase by amino acids in primary cultured rat cortical neurons

We investigated the effects of pregnenolone sulfate (PS) on the [Ca2+]i increase induced by gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) using fluorescence imaging. PS inhibited the 50 microM GABA-induced increase in [Ca2+]i in a dose-dependent manner with an IC50 of 30 microM. The inhibitory effect of PS was apparent within 5 min and was in a non-competitive manner, suggesting that PS may act directly to the membrane level but indirectly to the GABA binding sites. Our previous study has already shown that the GABA-induced Ca2+ increase involves GABAA receptors and the similar pathway to a high K(+)-induced Ca2+ response (Takebayashi et al., 1996). Because 50 microM of PS could not inhibit a 25 mM K(+)-induced Ca2+ increase, it seems likely that the site of the inhibitory action of PS on the GABA-induced Ca2+ increase may be independent of the pathway of the high K(+)-induced Ca2+ response, but rather at GABAA receptor complex. In contrast, PS potentiated the 50 microM NMDA-induced increase in [Ca2+]i in a dose-dependent manner. The magnitude of the NMDA response was approximately doubled in the presence of 100 microM of PS. However, PS did not affect the acetylcholine(Ach)-induced increase in [Ca2+]i. Furthermore, corticosterone had little effect on the GABA- and NMDA-induced Ca2+ increases, indicating that the alteration of the Ca2+ response is specific for PS. In conclusion, it is suggested that PS modulates differentially [Ca2+]i increase induced by GABA and NMDA.

Brachial arterial blood flow during static handgrip exercise of short duration at varying intensities studied by a Doppler ultrasound method

The purpose of this study was to determine forearm blood flow changes during static handgrip exercise at different intensities in relation to heart rate and blood pressure. Seven active women performed static handgrip exercise at intensities of 10, 30, 50 and 70% maximum voluntary contraction (MVC) in a supine position for 1 min. During exercise at different intensities, the brachial arterial blood flow (Doppler ultrasound method), calculated from vessel diameter, flow velocity and heart rate (measured by ECG), increased to a similar level (137.3 +/- 20.2-160.9 +/- 26.1 mL min-1) from pre-exercise control value (87.5 +/- 14.1 mL min-1). These increases at the lower intensities were attributable to increased in-flow during one cardiac cycle, whereas at the higher intensities, they were due to increased heart rate. Both systolic and diastolic blood pressure (Finapres) changes increased from 10% MVC (16.1 +/- 3.4, 9.0 +/- 1.7 mmHg) up to 50% MVC (33.8 +/- 6.7, 25.0 +/- 4.9 mmHg), but were disproportionately more elevated at 70% MVC (46.1 +/- 7.9, 42.9 +/- 8.9 mmHg), suggesting neural vasoconstriction had occurred. Immediate post-exercise hyperaemia, used as an indicator of poor blood supply, became greater as the exercise intensity increased. These results suggest that the brachial arterial blood flow was maintained at a similar level during 60-s static handgrip exercise at different intensities by elevating the blood pressure and heart rate, which probably counteracted the increased intramuscular pressure and neural vasoconstriction occurring at the higher exercise intensity. The magnitude of the post-exercise hyperemic response increased as exercise level increased despite increased blood-flow to the arm during-exercise. This suggests a worsening imbalance in oxygen delivery in forearm muscles at higher levels of exercise.

Modulation of endothelin-induced intracellular Ca2+ mobilization by interleukin-1 beta and lipopolysaccharide in C6 rat glioma cells

We have investigated the effects of interleukin (IL)-1 beta and lipopolysaccharide (LPS) on endothelin (ET)-induced intracellular Ca2+ rise in C6 rat glioma cells in order to study the mechanisms of their effects on Ca2+ signaling systems. Pretreatment with IL-1 beta (10(3) U/mL) and LPS (1 microgram/mL) for 24 h significantly inhibited 100 nM ET-1-induced increase in intracellular Ca2+ either in the presence or absence of external Ca2+. Their inhibitory effects were in dosedependent (IL-1 beta; 50-1000 U/mL, LPS; 10-1000 ng/mL) and time-dependent (12-24 h) manners. A tyrosine kinase antagonist genistein (50 microM) but not a protein kinase C inhibitor H7 (30 microM) prevented the inhibition of the ET response by IL-1 beta and LPS. These results suggest that activation of tyrosine kinase may be essential for the inhibition of the ET receptor-mediated Ca2+ signaling systems by IL-1 beta and LPS.

Plasma levels of cyclic GMP, immune parameters and depressive status during interferon therapy. A prospective study in Japan

In this report, we investigated the relationship between depressive symptoms and plasma interferon (IFN)-alpha-like immunoreactivity, cyclic GMP (cGMP) and soluble interleukin-2 receptor (sIL-2R) levels during IFN therapy. An altered mood state was observed in 5 of 26 patients. IFN-alpha-like immunoreactivity in the depressed group tended to be elevated. cGMP levels of depressed patients were significantly greater than those of control subjects before and 6 weeks after IFN therapy. However, sIL-2R levels were not different between the two groups. These results suggest that a number of patients suffered from depression during IFN therapy and that patients had greater concentrations of cGMP levels.

Chronic treatment with antidepressants, verapamil, or lithium inhibits the serotonin-induced intracellular calcium response in individual C6 rat glioma cells

The effects of chronic treatment with antidepressants, verapamil, or lithium on serotonin (5-HT)-induced Ca2+ increase were investigated in single C6BU-1 glioma cells with digital imaging microscopy. Clomipramine and citalopram, at a concentration of 100 nM, decreased the peak values of 5-HT-induced [Ca2+]i changes. Verapamil (100 nM), a calcium antagonist, and lithium (1 mM) also inhibited the peak amplitudes in the same way. The present findings suggest that chronic treatment with antidepressants, verapamil, or lithium, at therapeutic concentrations, have the common action of inhibiting 5-HT-mediated [Ca2+]i increase.

Enhanced calcium response to serotonin in platelets from patients with affective disorders

In this report we have investigated the intracellular calcium (Ca2+) mobilization mediated by serotonin 5-HT2A receptors in the platelets of 13 patients with bipolar disorder and 12 patients with major depression in comparison with 15 healthy control subjects. We found an enhanced intracellular Ca2+ rise in response to 5-HT in platelets from both bipolar patients and patients with major depression. The 5-HT2A receptor-mediated intracellular Ca2+ signaling mechanism may have an important role in the pathophysiology of affective disorders.

Usage of haloperidol for delirium in cancer patients

Although haloperidol is mainly used for the medical treatment of delirium in cancer patients, there are no universally accepted guidelines for its usage. We accordingly assessed the usefulness in managing delirium of a haloperidol treatment regimen in ten delirious cancer patients. The results of this preliminary study suggest that, in the management of delirium, appropriate usage of haloperidol on the first day is important as it affects the dosage thereafter.

Differential cardiorespiratory response to combined exercise with different combinations of forearm and calf exercise

The purpose of this study was to examine whether cardiorespiratory responses to combined rhythmic exercise (60 contractions.min-1) was affected by different combinations of upper and lower limb exercise in seven healthy women. Six different rhythmic exercises were compared: 6-min rhythmic handgrip at 10% of isometric maximal voluntary contraction (MVC) (H10); 6-min rhythmic plantar flexion at 10% MVC (P10); exhausting rhythmic handgrip at 50% MVC (H50); exhausting rhythmic plantar flexion at 50% MVC (P50); H50 was added to P10 (P10H50); and P50 was added to H10 (H10P50). Exercise duration, after handgrip was combined with plantar flexion (P10H50), was shorter than that of H50, although the exercise duration of H10P50 was not significantly different from P50. No significant difference was found between the difference from rest in oxygen uptake (delta VO2) during H10P50 and the sum of delta VO2 during H10 and P50. Also, the differences from rest in forearm blood flow (delta FBF) and calf blood flow (delta CBF) during H10P50 were not significantly different from delta FBF in H10 and from delta CBF in P50. In contrast, delta VO2 in P10H50 was lower than the sum of delta VO2 in P10 and H50 (P < 0.05), and delta FBF in P10H50 was lower than that in H50 (P < 0.05), while delta CBF was not significantly different between P10H50 and P10. The changes in heart rate from rest (delta HR) during the combined exercises were lower than the sums of delta HR in the corresponding single exercises (P < 0.05). These results demonstrated an inhibitory summation of several cardiorespiratory responses to combined exercise resulting in a reduction in exercise performance which would seem to occur easily when upperlimb exercise is added to lower limb exercise.