Reactive oxygen species produced by Zn2+ influx after exposure to AMPA, but not NMDA and their capturing effect on nigral dopaminergic protection

Glutamate excitotoxicity is involved in dopaminergic degeneration in the substantia nigra pars compacta (SNpc). Here we compared vulnerability to neurodegeneration after exposure to NMDA and AMPA. Apomorphine-induced movement disorder and dopaminergic degeneration in the SNpc, which are associated with Parkinson's syndrome, were induced after injection of AMPA into the SNpc of rats, but not after injection of NMDA. Co-injection of 1-naphthyl acetyl spermine (NASPM), a selective blocker of Ca²⁺- and Zn²⁺-permeable GluR2-lacking AMPA receptors rescued dopaminergic degeneration and increase in intracellular Zn²⁺ by AMPA. Furthermore, we tested the effect of capturing reactive oxygen species (ROS) produced by Zn²⁺ on neuroprotection in vivo. The levels of ROS, which were determined by HYDROP, a membrane-permeable H₂O₂ fluorescence probe and Aminophenyl Fluorescein (APF), a fluorescence probe for hydroxyl radical and peroxynitrite, were increased after injection of AMPA, but not after co-injection of CaEDTA, an extracellular Zn²⁺ chelator, suggesting that increase in Zn²⁺ influx by AMPA elevates the levels of intracellular ROS. AMPA-mediated dopaminergic degeneration was completely rescued by co-injection of either HYDROP or APF. The present study indicates that neurotoxic signaling of the influx of extracellular Zn²⁺ through Zn²⁺-permeable GluR2-lacking AMPA receptors is converted to ROS production and that capturing the ROS completely protects dopaminergic degeneration after exposure to AMPA, but not NMDA. It is likely that regulation of the conversion from Zn²⁺ influx into ROS production plays a key role to preventing Parkinson's syndrome.

Heated Leaf Extract of Coriandrum sativum L. Protects Nigral Dopaminergic Degeneration in Rats

Coriandrum sativum L. (coriander), which is an annual herb of the Apiaceae family, has been traditionally used as a remedy. Here we tested whether heated extract of coriander leaf protects nigral dopaminergic neurodegeneration after exposure to 6-hydroxydopamine (6-OHDA). After injection of 6-OHDA into the rat substantia nigra pars compacta (SNpc), dopaminergic degeneration, which was determined by tyrosine hydroxylase immunostaining, was rescued by co-injection of CaEDTA, an extracellular Zn²⁺ chelator, suggesting that extracellular Zn²⁺ influx is involved in neurodegeneration. Both intracellular Zn²⁺ dysregulation determined by ZnAF-2 fluorescence and dopaminergic degeneration in the SNpc induced by 6-OHDA were rescued by co-injection of 0.25% coriander extract, which also reduced reactive oxygen species (ROS) production in the SNpc determined by aminophenyl fluorescein fluorescence. The present study suggests that coriander leaf extract protects nigral dopaminergic neurodegeneration induced by intracellular Zn²⁺ dysregulation. It is likely that the nutraceutical property of coriander leaf extract contributes to the protection via reducing ROS production.

Paraquat-induced intracellular Zn2+ dysregulation causes dopaminergic degeneration in the substantia nigra, but not in the striatum

Parkinson's disease is characterized by a selective death of nigrostriatal dopaminergic neurons, while the difference in the vulnerability to the death between the substantia nigra pars compacta (SNpc) and the striatum is poorly understood. Here we tested the difference focused on paraquat (PQ)-induced intracellular Zn²⁺ toxicity via extracellular glutamate accumulation. When PQ was locally injected into the SNpc and the striatum, dopaminergic degeneration was observed in the SNpc, but not in the striatum. Intracellular hydrogen peroxide (H₂O₂) produced by PQ was increased in both the SNpc and the striatum. In contrast, extracellular glutamate accumulation was observed only in the SNpc and rescued in the presence of N-(p-amylcinnamoyl)anthranilic acid (ACA), a blocker of the transient receptor potential melastatin 2 (TRPM2) cation channels. PQ increased intracellular Zn²⁺ level in the SNpc, but not in the striatum. The increase was rescued by 1-naphthyl acetyl spermine (NASPM), a selective blocker of Ca²⁺- and Zn²⁺-permeable GluR2-lacking AMPA receptors. PQ-induced dopaminergic degeneration in the SNpc was rescued by ACA, NASPM, and GBR, a dopamine reuptake inhibitor. The present study indicates intracellular H₂O₂ produced by PQ, which is taken up through dopamine transporters, is retrogradely transported to presynaptic glutamatergic terminals, activates TRPM2 channels, accumulates glutamate in the extracellular compartment, and induces intracellular Zn²⁺ dysregulation via Ca²⁺- and Zn²⁺-permeable GluR2-lacking AMPA receptor activation, resulting in dopaminergic degeneration in the SNpc. However, H₂O₂ signaling is not the case in the striatum. Paraquat-induced Zn²⁺ dysregulation plays a key role for neurodegeneration in the SNpc, but not in the striatum.

Intracellular hydrogen peroxide produced by 6-hydroxydopamine is a trigger for nigral dopaminergic degeneration of rats via rapid influx of extracellular Zn2

To elucidate the mechanism and significance of 6-hydroxydopamine (6-OHDA)-induced Zn²⁺ toxicity, which is involved in neurodegeneration in the substantia nigra pars compacta (SNpc) of rats, we postulated that intracellular hydrogen peroxide (H₂O₂) produced by 6-OHDA is a trigger for intracellular Zn²⁺ dysregulation in the SNpc. Intracellular H₂O₂ level elevated by 6-OHDA in the SNpc was completely inhibited by co-injection of GBR 13069 dihydrochloride (GBR), a dopamine reuptake inhibitor, suggesting that 6-OHDA taken up through dopamine transporters produces H₂O₂ in the intercellular compartment of dopaminergic neurons. When the SNpc was perfused with H₂O₂, glutamate accumulated in the extracellular compartment and the accumulation was inhibited in the presence of N-(p-amylcinnamoyl)anthranilic acid (ACA), a blocker of the transient receptor potential melastatin 2 (TRPM2) channels. In addition to 6-OHDA, H₂O₂ also induced intracellular Zn²⁺ dysregulation via AMPA receptor activation followed by nigral dopaminergic degeneration. Furthermore, 6-OHDA-induced nigral dopaminergic degeneration was completely inhibited by co-injection of either HYDROP, an intracellular H₂O₂ scavenger or GBR into the SNpc. The present study indicates that H₂O₂ is produced by 6-OHDA taken up through dopamine transporters in the SNpc, is retrogradely transported to presynaptic glutamatergic terminals, activates TRPM2 channels, accumulates glutamate in the extracellular compartment, and induces intracellular Zn²⁺ dysregulation via AMPA receptor activation, resulting in nigral dopaminergic degeneration prior to movement disorder. It is likely that intracellular H₂O₂, but not extracellular H₂O₂, is a key trigger for nigral dopaminergic degeneration via intracellular Zn²⁺ dysregulation.

Comparison of clinical outcomes between percutaneous coronary intervention for the de novo lesion versus in-stent restenosis lesion

Background and objective

Percutaneous coronary intervention (PCI) with metallic coronary stent (bare-metal stents [BMS] and drug-eluting stents [DES]) implantation is most frequently performed therapeutic procedures for coronary artery disease. In-stent restenosis (ISR) is a critical drawback of metallic coronary stents. Incidence of ISR has been reported in up to 30% after BMS implantation. The use of DES has greatly reduced the proportion of restenosis compared with the BMS. However, ISR still remains the primary concern after PCI even in the contemporary DES era, and thought to be associated with worse clinical outcomes. However, comparative data on ISR and de novo lesions are rare.

Purpose

The aim of the present study was to compare the clinical outcomes after PCI for the de novo lesion and the ISR lesion.

Methods

We performed a retrospective analysis of patients who underwent PCI between 2013 and 2020. The incidences of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death were evaluated. MACCE was defined as composite of cardiovascular death, non-fatal myocardial infarction, and stroke.

Results

In this study, 1538 patients were enrolled and divided into two groups: PCI for de novo lesion group (n=1258, 81.8%), and PCI for ISR lesion group (n=280, 18.2%). Patients in the ISR lesion group were significantly older and had higher prevalence of hypertension, diabetes mellitus, dyslipidemia and chronic kidney disease than patients in the de novo lesion group. During a median follow-up period of 1.9 years, Kaplan-Meier curves showed no significant differences in the incidences of MACCE (log-rank, p=0.86) and all-cause death (p=0.84) between two groups. After adjustment for other covariates, PCI for ISR lesion were not significantly associated with MACCE (hazard ratio [HR], 1.10; 95% confidential interval [CI], 0.61–1.97; p=0.76) and all-cause death (HR, 0.93; 95% CI, 0.56–1.56; p=0.79)

Conclusion

PCI for the ISR lesion was not associated with worse clinical outcomes compared with PCI for the de novo lesion.

Funding Acknowledgement

Type of funding sources: None.

The relationship among extent of lipid-rich plaque, factors associated with a reduction of lipid-rich plaque and late lumen loss: a near-infrared spectroscopy and intravascular ultrasound study

Background

Near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) are useful imaging modalities to identify lipid-rich plaque (LRP) which is associated with an increased risk of future cardiovascular events in individuals undergoing PCI. Pathological studies have raised concerns that treating LRP with stents may impair vascular healing. However, the impact of stent implantation to LRP lesions was less known. Moreover, little information is available about changes in the extent of LRP at before and after PCI.

Purpose

The aim of this study was to investigate changes in LRP by NIRS between pre- and post-stent implantation, and to evaluate an association among impact of LRP by NIRS at pre- and post-stenting and late lumen loss (LLL) by angiography.

Methods

We studied 175 lesions in 149 patients who underwent PCI under NIRS-IVUS guidance and follow-up angiography at 8-month later from 2017 to 2020. Plaque characteristics on IVUS, the extent of LRP [defined as a long segment with a 4-mm maximum lipid core burden index (maxLCBI4mm)] on NIRS, and quantitative coronary angiography measurements were analyzed. We evaluated a change of the extent of LRP between pre- and post-stenting at index PCI procedure, and association between the extent of LRP and a 8-month LLL at follow-up coronary angiography. A large LRP was defined as maxLCBI4mm>400 at pre-stenting.

Results

Mean age was 64.5 years old, and 123 (82%) patients were male. The prevalence of large LRP was 51% and median plaque burden at minimum lumen area was 81%. The extent of LRP at culprit lesion significantly decreased from pre- to post-stenting (median maxLCBI4mm [interquartile range (IQR)]: 407 [199, 580] to 133 [13, 319], p<0.001) (Figure 1). In multivariable liner regression analysis, independent predictors for the reduction of LRP were a pre-stenting LRP (β coefficient = −57.0, 95% confidence interval (CI) [−65.1 to −48.8], p<0.001) and plaque burden (β coefficient = −30.0, 95% CI [−56.6 to −3.4], p<0.001), respectively. On the other hands, patient comorbidities, lipid profile and inflammatory markers were not associated with the reduction of LRP (all p>0.05). Median LLL at follow-up angiogram was 0.17 [0.07–0.35] mm. Both the extent of pre- and post-stenting LRP were not associated with LLL (r=0.018, p=0.80 and r=0.022, p=0.76, respectively) (Figure 2). In addition, there was no significant difference in LLL between the post-stenting large and non-large LRP (median [IQR] 0.18 [0.08–0.35] vs. 0.17 [0.07–0.35]; P=0.95).

Conclusions

This study showed coronary stent implantation significantly reduced the NIRS-derived LRP in patients undergoing PCI. Although the extent of pre-stenting LRP and IVUS plaque burden predicted the reduction of LRP, the extent of pre- and post-stenting LRP were not associated with LLL. These findings suggest that stent implantation for LRP, even in a large LRP, is safe and does not affect LLL.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Scatter plotsFigure 2. CENTRAL Figure

Coronary lipid-rich plaque characteristics with acute coronary syndrome and chronic coronary syndrome: a near infrared spectroscopy and intravascular ultrasound study

Background

Asians have a much lower incidence of adverse coronary events than Caucasians, and the characteristics of vulnerable plaque might be different among the ethnics.

Purpose

The aim of this study was to investigate the clinical characteristics of lipid-rich plaque (LRP) in the Asian population and we also aimed to distinguish the characteristics of an acute coronary syndrome (ACS) culprit lesion and a chronic coronary syndrome (CCS) culprit lesion. Furthermore, we evaluated the association between lipid core burden index (LCBI) and cardiovascular risk factors, lipid profiles, and inflammatory biomarkers, as determined in vivo by near infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging in patients undergoing percutaneous coronary intervention (PCI).

Methods

We evaluated 207 patients (ACS, n=75; CCS, n=132) who underwent PCI under NIRS-IVUS. Plaque characteristics and the extent of LRP [defined as a long segment with a 4-mm maximum LCBI (maxLCBI4mm)] on NIRS in de-novo culprit and non-culprit segments were analyzed.

Results

The mean age was 65 years old and 82% of patients were male. The ACS culprit lesions had a significantly higher maxLCBI4mm (median [interquartile range (IQR)]: 533 [385–745] vs. 361 [174–527], p<0.001) than the CCS culprit lesions. Whereas, no significant difference was seen in maxLCBI4mm between ACS and CCS non-culprit lesion segments (246 [53, 342] vs. 185 [37, 350], p=0.47) (Figure 1). Receiver-operating characteristic analysis showed that the NIRS maxLCBI4mm could distinguish the ACS culprit segment from the CCS culprit segment, with a sensitivity of 73% and a specificity of 69% (c-statistic = 0.69; p<0.001, cut-off value of max LCBI4mm = 408) (Figure 2). On multivariate logistic analysis, a large LRP (defined as maxLCBI4mm ≥400) was the strongest independent predictor of the ACS culprit segment (odds ratio, 3.87; 95% confidence interval, 1.95–8.02). In non-culprit segments, 19.8% of patients had at least one large LRP without a small lumen. No significant correlation was found between the extent of LRP and circulating lipid profiles and inflammatory makers biomarkers (hs-CRP, IL-6, TNF-α) in both the culprit and non-culprit lesion segments, whereas the extent of LRP was positively correlated with IVUS plaque burden (r=0.24, p<0.001).

Conclusions

We confirmed that NIRS-IVUS plaque assessment could be useful to differentiate ACS from CCS culprit lesions, and that a threshold maxLCBI4mm ≥400 was clinically suitable in Japanese patients. No systemic surrogate markers were found to be associated with the extent of LRP by NIRS in culprit and non-culprit segments. Consequently, we believe that direct intravascular evaluation of coronary plaque characteristics remains important for identification of high-risk LRP.

Funding Acknowledgement

Type of funding sources: None. Figure 1. The difference of maxLCBI4mmFigure 2. ROC curve

Age-related vulnerability to nigral dopaminergic degeneration in rats via Zn2+-permeable GluR2-lacking AMPA receptor activation

On the basis of the evidence that extracellular Zn2+ influx induced with AMPA causes Parkinson's syndrome in rats that apomorphine-induced movement disorder emerges, here we used a low dose of AMPA, which does not increase intracellular Zn2+ level in the substantia nigra pars compacta (SNpc) of young adult rats, and tested whether intracellular Zn2+ dysregulation induced with AMPA is accelerated in the SNpc of aged rats, resulting in age-related vulnerability to Parkinson's syndrome. When AMPA (1 mM) was injected at the rate of 0.05 μl/min for 20 min into the SNpc, intracellular Zn2+ level was increased in the SNpc of aged rats followed by increase in turning behavior in response to apomorphine and nigral dopaminergic degeneration. In contrast, young adult rats do not show movement disorder and nigral dopaminergic degeneration, in addition to no increase in intracellular Zn2+. In aged rats, movement disorder and nigral dopaminergic degeneration were rescued by co-injection of either extracellular (CaEDTA) or intracellular (ZnAF-2DA) Zn2+ chelators. 1-Naphthyl acetyl spermine (NASPM), a selective blocker of Ca2+- and Zn2+-permeable GluR2-lacking AMPA receptors blocked increase in intracellular Zn2+ in the SNpc of aged rats followed by rescuing nigral dopaminergic degeneration. The present study indicates that intracellular Zn2+ dysregulation is accelerated by Ca2+- and Zn2+-permeable GluR2-lacking AMPA receptor activation in the SNpc of aged rats, resulting in age-related vulnerability to Parkinson's syndrome.

P1745Clinical characteristics and long-term outcome in patients with helicopter-transported acute coronary syndrome after primary percutaneous coronary intervention

Background

Reducing delay to percutaneous coronary intervention improves functional outcome and reduces long-term mortality. Transportation by helicopter is often quicker than ground transport and thus may improve overall prognosis through reduced ischemic injury and infarction size. Our hospital is located on the medically-depopulated peninsula surrounded by mountain. The journey from the southern tip of the peninsula to the critical care medical center of our hospital take 1.5 hour by a ground ambulance but only 15 minutes by helicopter.

We compared the clinical characteristics and long-term mortality between air and ground transport of ACS patients for primary PCI.

Methods

We conducted an observational cohort study evaluating 2324 patients (mean age 68.5±12.0, male 75.2%) with ACS underwent primary PCI between April 2004 and December 2017 at our hospital.

We divided into three groups according to transportation system type (air, ground, walk-in).

The primary outcome was defined as all-cause death during the long-term follow-up.

Results

Among the entire cohort, 577 patients (24.8%) were transported by air. 1326 (57.1%) patients by ambulance, 421 (18.1%) patients by walk. Baseline characteristics were comparable, but patients by air had a higher prevalence of ST-elevation myocardial infarction.

The rate of long-term mortality was comparable during the median follow up of 6 years (air, 21.1% vs. ground, 21.4% vs. walk-in, 21.1%, respectively, log-rank p=0.72). Multivariate Cox regression analysis showed no significant association between air transportation and long-term mortality (Adjusted HR [vs ground] 1.05, 95% CI 0.60–1.78, p=0.85 and [vs walk-in] 0.94, 95% CI 0.62–1.43, respectively, p=0.77).

Kaplan-Meier curve

Conclusions

The rate of long-term mortality in patients with ACS transported by air was comparable with those transported by ground.

Intake of Heated Leaf Extract of Coriandrum sativum Contributes to Resistance to Oxidative Stress via Decreases in Heavy Metal Concentrations in the Kidney

Coriandrum sativum (coriander) is an annual herb of the Apiaceae family and has been used as a traditional remedy. Here we examined whether heated leaf extract of coriander decreases the concentrations of heavy metals in tissues. Male ddY mice were given a drinking water containing 0.25% of heated leaf extract of coriander for 8 weeks. Eight weeks after the intake, the concentrations of zinc, iron, copper, arsenic, and cadmium were measured in the liver and kidney. The intake of coriander did not modify the concentrations of all heavy metals tested in the liver, but decreased the concentrations of iron, arsenic, and cadmium in the kidney. Because heavy metals can induce oxidative stress, the effect of coriander intake on hydrogen peroxide-induced oxidative stress was compared between slices from the kidney and liver. The slices were immersed in Ringer solution containing 100 μM hydrogen peroxide and aminophenyl fluorescein (APF), a probe for detecting reactive oxygen species (ROS). APF fluorescence was markedly increased in the control kidney slices, while the increase was completely blocked in kidney slices from coriander intake group. In contrast, APF fluorescence was also markedly increased in the control liver slices, while the increase was not blocked by coriander intake. The present study indicates that intake of coriander leaf extract contributes to powerful resistance to oxidative stress in the kidney, probably via decreased concentrations in heavy metals. It is likely that decrease in arsenic concentration to the detection limit is a major factor for the resistance.

Blockade of Rapid Influx of Extracellular Zn2+ into Nigral Dopaminergic Neurons Overcomes Paraquat-Induced Parkinson's Disease in Rats

The herbicide paraquat (PQ) has been reported to enhance the risk of developing Parkinson's disease (PD) from epidemiological studies. PQ-induced reactive oxygen species (ROS) are linked with a selective loss of nigrostriatal dopaminergic neurons. Here, we first report a unique mechanism of nigrostriatal dopaminergic degeneration, in which rapid intracellular Zn²⁺ dysregulation via PQ-induced ROS production causes PD in rats. When the substantia nigra pars compacta (SNpc) of rats was perfused with PQ, extracellular concentrations of glutamate and Zn²⁺ were increased and decreased, respectively, in the SNpc. These changes were ameliorated by co-perfusion with Trolox, an antioxidative agent. In in vitro slice experiments, PQ rapidly increased extracellular Zn²⁺ influx via AMPA receptor activation. Both loss of nigrostriatal dopaminergic neurons and increase in turning behavior in response to apomorphine were markedly reduced by coinjection of PQ and intracellular Zn²⁺ chelator, i.e., ZnAF-2DA into the SNpc. Furthermore, loss of nigrostriatal dopaminergic neurons induced with a low dose of PQ, which did not induce any behavioral abnormality, was completely blocked by coinjection of ZnAF-2DA. The present study indicates that rapid influx of extracellular Zn²⁺ into dopaminergic neurons via AMPA receptor activation, which is initially induced by PQ-mediated ROS production in the SNpc, induces nigrostriatal dopaminergic degeneration, resulting in PQ-induced PD in rats. Intracellular Zn²⁺ dysregulation in dopaminergic neurons is the cause of PQ-induced pathogenesis in the SNpc, and the block of intracellular Zn²⁺ toxicity leads to defending PQ-induced pathogenesis.

AMPA-induced extracellular Zn2+ influx into nigral dopaminergic neurons causes movement disorder in rats

On the basis of the findings that the rapid influx of extracellular Zn²⁺ into nigral dopaminergic neurons causes dopaminergic neurodegeneration, here we report that AMPA causes movement disorder in rats. AMPA markedly increased turning behavior in response to apomorphine 1 and 2 weeks after AMPA injection into the substantia nigra pars compacta (SNpc), while AMPA-induced movement disorder was suppressed by co-injection of intracellular Zn²⁺ chelators, i.e., ZnAF-2DA and TPEN, suggesting that AMPA-induced movement disorder is due to intracellular Zn²⁺ dysregulation. Furthermore, AMPA markedly induced loss of nigrostriatal dopaminergic neurons 2 weeks after AMPA injection into the SNpc, while AMPA-induced neurodegeneration was also suppressed in the SNpc and the striatum by co-injection of ZnAF-2DA and TPEN. AMPA rapidly increased nigral intracellular Zn²⁺ after AMPA injection into the SNpc and this increase was blocked by co-injection of TPEN. These results indicate that AMPA receptor activation rapidly increases influx of extracellular Zn²⁺ into nigral dopaminergic neurons and causes nigrostriatal dopaminergic neurodegeneration, resulting in movement disorder in rats. The evidence that AMPA-induced intracellular Zn²⁺ dysregulation causes movement disorder via nigrostriatal dopaminergic neurodegeneration suggests that AMPA receptors, probably Ca²⁺- and Zn²⁺-permeable GluR2-lacking AMPA receptors are potential targets for overcoming Parkinson's syndrome.

Involvement of intracellular Zn2+ signaling in LTP at perforant pathway-CA1 pyramidal cell synapse

Physiological significance of synaptic Zn²⁺ signaling was examined at perforant pathway-CA1 pyramidal cell synapses. In vivo long-term potentiation (LTP) at perforant pathway-CA1 pyramidal cell synapses was induced using a recording electrode attached to a microdialysis probe and the recording region was locally perfused with artificial cerebrospinal fluid (ACSF) via the microdialysis probe. Perforant pathway LTP was not attenuated under perfusion with CaEDTA (10 mM), an extracellular Zn²⁺ chelator, but attenuated under perfusion with ZnAF-2DA (50 μM), an intracellular Zn²⁺ chelator, suggesting that intracellular Zn²⁺ signaling is required for perforant pathway LTP. Even in rat brain slices bathed in CaEDTA in ACSF, intracellular Zn²⁺ level, which was measured with intracellular ZnAF-2, was increased in the stratum lacunosum-moleculare where perforant pathway-CA1 pyramidal cell synapses were contained after tetanic stimulation. These results suggest that intracellular Zn²⁺ signaling, which originates in internal stores/proteins, is involved in LTP at perforant pathway-CA1 pyramidal cell synapses. Because the influx of extracellular Zn²⁺ , which originates in presynaptic Zn²⁺ release, is involved in LTP at Schaffer collateral-CA1 pyramidal cell synapses, synapse-dependent Zn²⁺ dynamics may be involved in plasticity of postsynaptic CA1 pyramidal cells.

In vitro and in vivo physiology of low nanomolar concentrations of Zn2+ in artificial cerebrospinal fluid

Artificial cerebrospinal fluid (ACSF), i.e., brain extracellular medium, which includes Ca²⁺ and Mg²⁺, but not other divalent cations such as Zn²⁺, has been used for in vitro and in vivo experiments. The present study deals with the physiological significance of extracellular Zn²⁺ in ACSF. Spontaneous presynaptic activity is suppressed in the stratum lucidum of brain slices from young rats bathed in ACSF containing 10 nM ZnCl₂, indicating that extracellular Zn²⁺ modifies hippocampal presynaptic activity. To examine the in vivo action of 10 nM ZnCl₂ on long-term potentiation (LTP), the recording region was perfused using a recording electrode attached to a microdialysis probe. The magnitude of LTP was not modified in young rats by perfusion with ACSF containing 10 nM ZnCl₂, compared to perfusion with ACSF without Zn²⁺, but attenuated by perfusion with ACSF containing 100 nM ZnCl₂. Interestingly, the magnitude of LTP was not modified in aged rats even by perfusion with ACSF containing 100 nM ZnCl₂, but enhanced by perfusion with ACSF containing 10 mM CaEDTA, an extracellular Zn²⁺ chelator. The present study indicates that the basal levels of extracellular Zn²⁺, which are in the range of low nanomolar concentrations, are critical for synaptic activity and perhaps increased age-dependently.

Behavioral Abnormality Induced by Enhanced Hypothalamo-Pituitary-Adrenocortical Axis Activity under Dietary Zinc Deficiency and Its Usefulness as a Model

Dietary zinc deficiency increases glucocorticoid secretion from the adrenal cortex via enhanced hypothalamo-pituitary-adrenocortical (HPA) axis activity and induces neuropsychological symptoms, i.e., behavioral abnormality. Behavioral abnormality is due to the increase in glucocorticoid secretion rather than disturbance of brain zinc homeostasis, which occurs after the increase in glucocorticoid secretion. A major target of glucocorticoids is the hippocampus and their actions are often associated with disturbance of glutamatergic neurotransmission, which may be linked to behavioral abnormality, such as depressive symptoms and aggressive behavior under zinc deficiency. Glucocorticoid-mediated disturbance of glutamatergic neurotransmission in the hippocampus is also involved in the pathophysiology of, not only psychiatric disorders, such as depression, but also neurodegenerative disorders, e.g., Alzheimer’s disease. The evidence suggests that zinc-deficient animals are models for behavioral and psychological symptoms of dementia (BPSD), as well as depression. To understand validity to apply zinc-deficient animals as a behavioral abnormality model, this paper deals with the effect of antidepressive drugs and herbal medicines on hippocampal dysfunctions and behavioral abnormality, which are induced by enhanced HPA axis activity under dietary zinc deficiency.

Development and evaluation of 'disaster preparedness' educational programme for pregnant women

PURPOSE

The objective of this study is the development and evaluation of the usability of an educational programme that teaches disaster preparedness to pregnant women.

METHODS

This intervention study examined an intervention group that attended an educational programme and a control group that did not. The subjects were pregnant women in their second trimester. The programme was developed with prior studies and evaluated by self-administered questionnaires that asked about disaster preparedness. The questionnaire was administered twice to the participants in both groups: to the intervention group just before the childbirth class and 1 month after the class, and to the control group at the time of their maternity examination and 1 month afterwards. Two hundred twenty-six members of the intervention group and 262 members of the control group responded to both questionnaires. Of these, 99 of the intervention group and 104 of the control group were primiparous without disaster experience, and the programme was evaluated by comparing these two groups. Effects due to the disaster experience were also analysed within the intervention group.

RESULTS

Among primiparous without disaster experience, an intervention effect was found in items concerning awareness modification (five of six items) and behaviour modification (three of seven items). The intervention effect was particularly pronounced in a comparison of primiparous without disaster experience.

CONCLUSIONS

An intervention effect was found among the pregnant women who took the programme. In particular, it was statistically significant among primiparous without disaster experience, which suggests that the programme should be shaped to reflect this subject demographic.

The clock gene cryptochrome of Bactrocera cucurbitae (Diptera: Tephritidae) in strains with different mating times

Differences in mating time between populations can give rise to premating reproductive isolation. Tephritid fruit flies exhibit large variation in mating time among intra- or inter-specific populations. We previously cloned the clock gene period from two strains of melon fly, Bactrocera cucurbitae; in one the individuals mate early during the day, whereas in the other the individuals mate later. These strains were originally established by divergent artificial selection for developmental time, 'short' and 'long', with early and late mating times, respectively. The deduced amino acid sequences of PERIOD proteins for these two strains were reported to be identical. Here we cloned another clock gene cryptochrome (cry) from the two strains, and found two stable amino acid substitutions in the strains. In addition, the allele frequency at the two polymorphic sites of cry gene correlated with the circadian locomotor period (tau) across strains, whereas the expression pattern of cry mRNA in the heads of flies taken from the short strain significantly differed from that from the long strain. These findings suggest that variation in the cry gene is related to differences in the circadian behaviour in the two strains, thus implying that the cry gene may have an important role in reproductive isolation.

TRANSURETHRAL INCISION FOR HEMATOSPERMIA CAUSED BY EJACULATORY DUCT OBSTRUCTION

Hematospermia is supposed to be derived from pathological conditions in the seminal vesicle, prostate, testis, epididymis, or urethra. A recent advance in diagnostic procedures has demonstrated the seminal vesicle, the prostate, and midline cyst as potential sources of hematospermia. The authors describe a case of hematospermia caused by ejaculatory duct obstruction, in which a transurethral technique was successful. A 51-year-old male was referred to the authors' clinic with a chief complaint of hematospermia. Transurethral ultrasonography showed a cystic lesion surrounded with hyperechoic area in the middle of the prostate. Vasography demonstrated the distal dilation of the ejaculatory duct. Magnetic resonance imaging demonstrated a high signal intensity area in the middle of the prostate. Urethrocystoscopy showed an enlarged cystic lesion with an orifice at the prostatic urethra, which was incised endoscopically. There was no complication observed postoperatively. Seven months after the technique, hematospermia resolved completely. A midline cyst should be considered a cause of hematospermia and the incidence of such cysts may be higher than that previously recognized. The transurethral technique is expected to be a successful treatment approach.

Diagnostic accuracy of cardiac metaiodobenzylguanidine scintigraphy in Parkinson disease

BACKGROUND AND PURPOSE

To estimate the diagnostic accuracy of cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigram for detection of Parkinson disease.

METHODS

A cross-sectional study with index test of MIBG scintigram and reference standard of U.K. Parkinson's Disease Brain Bank Criteria was performed in 403 patients. Ratio of cardiac-to-mediastinum MIBG accumulation was determined at 20 min (early H/M) and 4 h (late H/M). Area under the receiver-operator characteristic (ROC) curve, sensitivity and specificity in detecting Parkinson disease were analyzed. Accuracy was analyzed in a subgroup of patients with disease duration of 3 years or less.

RESULTS

Area under the ROC curve was 0.89 using either early or late H/M as a diagnostic marker (95% CI 0.85-0.92 for early H/M and 0.86-0.93 for late H/M). Sensitivity and specificity were 81.3% (76.1-85.8%) and 85.0% (77.7-90.6%) for early H/M and 84.3% (79.3-88.4%) and 89.5% (83.01-94.1%) for late H/M. In the subgroup with duration of 3 years or less, the ROC curve area, sensitivity, and specificity were 0.86 (0.79-0.92), 76.0% (64.8-85.1%), and 83.9% (71.7-92.4%) for early H/M and 0.85 (0.78-0.92), 73.3% (61.9-82.9%), and 87.5% (75.9-94.8%) for late H/M.

CONCLUSION

Although diagnostic accuracy of cardiac MIBG scintigram is high, it is limited because of insufficient sensitivity in patients with short duration.

Assessment of sperm quality analyzer II B: comparison with manual semen analysis and CASA

Two hundred and seven patients with male infertility were investigated. Total sperm concentration and percent progressive motility by SQA IIB showed high correlations with those of conventional manual method. Percent of normal morphology showed a significant correlation among these techniques. The sperm motility index (SMI) and total functional sperm concentration (TFSC) demonstrated high correlations with any variables of manual analysis. Only velocity and amplitude of lateral head displacement showed significant correlations with the variables obtained by SQA IIB, especially with SMI and TFSC. It was suggested that SQA IIB could be a useful instrument in the clinical practice of infertility as a screening test for semen quality.

Metastatic prostate cancer with normal level of serum prostate-specific antigen

The clinical and pathological features of metastatic prostate cancer with normal level of serum prostate-specific antigen (PSA) were investigated. Four patients with metastatic prostate cancer had serum PSA within the normal range at the diagnosis. All tumors were poorly-differentiated adenocarcinoma. Endocrine therapy was performed as the initial therapy in all patients. Despite subsequently treatment, all cases died of prostate cancer at 2, 8, 9 and 38 months. During disease progression, 3 of 4 patients had elevated serum markers such as carcinoembryonic antigen (CEA), CA19-9, CA15-3, CA125, neuron-specific enolase and pro-gastrin releasing peptide. Immunohistochemical examination of the initial biopsy specimens revealed that 4 and 3 cases were positive for CEA and chromogranin A, respectively. In advanced prostate cancer patients with low PSA level, those markers may aid in the follow up of disease.

Persistent Müllerian duct syndrome: a surgical approach

Laparoscopy revealed a left inguinal testis and a right abdominal testis. Surgery revealed uterus-like structures. The bilateral testes showed primitive testis without ovarian tissue. Physical examination showed a normal and an empty scrotum with a nonpalpable gonad. Chromosome analysis revealed 46,XY. Pathological findings demonstrated the immature testis and the immature uterus.

Establishment of heterotropic liver tissue mass with direct link to the host liver following implantation of hepatocytes transfected with vascular endothelial growth factor gene in mice

One of the major goals of tissue engineering is to establish an integrated organ in vivo. We have previously shown that transfection of vascular endothelial growth factor (VEGF) gene into hepatocytes promotes tissue formation by engrafted cells. Here we show that tissue growth was significantly enhanced by co-transplantation of hepatocyte growth factor (HGF) and tumor necrosis factor-alpha (TNF alpha) gene transfected hepatocytes with VEGF-gene transfected cells, but tissue islands were scattered nonspecifically in the abdomen of mice. The result brought us forward to the next step to establish an integrated mass and structural formation of liver tissue. We entrapped VEGF gene transfected hepatocytes in a nylon mesh bag and intraperitoneally engrafted close to the liver. Three weeks later, the bag was covered by a thick network of blood vessels, compared to the control. Histological examination showed that the blood vessels penetrated the parenchyma of the engrafted bag and formed a well-developed vessel network in the region. The use of hepatocytes from lacZ transgenic mice and PCR analysis demonstrated survival and albumin production by hepatocytes in the engrafted bag. Our model can potentially be developed into a heterotropic artificial liver with direct access to the host blood circulation.

Therapeutic effects of FTY720, a new immunosuppressive agent, in a murine model of acute viral myocarditis

OBJECTIVES

This study examines the efficacy of FTY720 (FTY), a new immunosuppressor, in the treatment of acute viral myocarditis in a murine model.

BACKGROUND

Immunosuppressive agents have no proven therapeutic efficacy in experimental or clinical myocarditis.

METHODS

Encephalomyocarditis virus was inoculated i.p. in DBA/2 mice on day 0. Postinoculation treatment consisted of FTY 10 mg/kg/day p.o. (FTY group), or cyclosporine A (CsA) 40 mg/kg/day p.o. (CsA group) or distilled water p.o. only (control group). Survival until day 14, as well as cardiac histopathology, virus concentrations, cytokines (interleukin [IL]-2, IL-12, interferon [IFN]-gamma and tumor necrosis factor [TNF]-alpha) and nitric oxide (NO) on day 5 were examined.

RESULTS

In the control and CsA groups, all mice died within 10 and 7 days, respectively. However, in the FTY group, 27% of the animals survived up to day 14. Compared with the control group, 1) histological scores were significantly lower in the FTY group but unchanged in the CsA group; 2) virus concentration was significantly higher in the CsA group but not in the FTY group; 3) expressions of IL-2, IL-12 and IFN-gamma in the heart were suppressed in both the FTY and CsA groups, though suppression was weaker in the FTY group; 4) TNF-alpha and NO were significantly increased in the CsA group but not in the FTY group.

CONCLUSIONS

FTY720 had a significant therapeutic effect in acute experimental myocarditis without inducing excessive virus replication. This report is the first to describe a beneficial effect by an immunosuppressive agent in the treatment of acute viral myocarditis.

Amlodipine inhibits the production of cytokines induced by ouabain

Recent studies have suggested that cytokines are capable of modifying cardiovascular function and that drugs used in the treatment of heart failure have various modulating properties on the production of cytokines. More recently, we have found that ouabain induces the production of cytokines. This study was performed to examine the effects of calcium channel blockers on the production of cytokines induced by a cardiac glycoside. Human peripheral blood mononuclear cells (PBMC) were obtained from healthy volunteers. PBMC were cultured in 0.1, 1, 10, and 30 micromol/l amlodipine, diltiazem, and nifedipine in presence of 1 micromol/l ouabain. After 24 h of incubation, IL-1alpha, IL-1beta, IL-6, and TNF-alpha were measured in the culture supernatants by enzyme-linked immunosorbent assay. Ouabain induced the production of IL-1alpha, IL-1beta and IL-6, but not of TNF-alpha. Induction of IL-1beta was most prominent. The production of IL-1alpha, and IL-6 was inhibited by amlodipine in a concentration-dependent manner and was significantly decreased at a concentration of 10 micromol/l. IL-1beta production was also inhibited by 30 micromol/l amlodipine. In contrast, neither diltiazem nor nifedipine inhibited the production of these cytokines. The unique property of amlodipine to inhibit the production of IL-1alpha, IL-1beta and IL-6 may contribute to its beneficial effects in heart failure patients.

High doses of digitalis increase the myocardial production of proinflammatory cytokines and worsen myocardial injury in viral myocarditis: a possible mechanism of digitalis toxicity

Results of recent studies suggest that proinflammatory cytokines cause myocardial contractile dysfunction, and that the drugs used to treat heart failure modulate the production of cytokines. This study was designed to examine the effects of digoxin in a murine model of heart failure induced by viral myocarditis. Four-week-old inbred DBA/2 mice were inoculated intraperitoneally with encephalomyocarditis virus (EMCV). Digoxin was given orally in doses of 0.1, 1 or 10 mg/kg daily from the day of virus inoculation. Interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha production in the heart were measured on day 5 after EMCV inoculation by enzyme-linked immunosorbent assay. The 14-day mortality tended to be increased in mice treated with 1 mg/kg, and was significantly increased in the group treated with 10 mg/kg per day. Myocardial necrosis and cellular infiltration on day 6 were significantly more severe in the high-dose digoxin group than in the control group. In the animals treated with 1 mg/kg digoxin, IL-1beta was significantly higher than in the control group. Intracardiac TNF-alpha levels were increased in a dose-dependent manner. These results suggest that digoxin worsens viral myocarditis, and that its use in high doses should be avoided in patients suffering from heart failure due to viral myocarditis.

Treatment of experimental viral myocarditis with interleukin-10

BACKGROUND

The T helper cell type 2-associated cytokine interleukin (IL)-10 has a variety of immunomodulatory properties. However, the effects of the cytokine on viral myocarditis remain unclear.

METHODS AND RESULTS

We studied the effects of recombinant human IL-10 (rhIL-10) fully active on mouse cells in a murine experimental model of acute viral myocarditis caused by the encephalomyocarditis virus (EMCV). Four-week-old DBA/2 mice were inoculated with EMCV (day 0). rhIL-10 (10 microg/mouse) was administered once daily, starting on day 0, and control mice received vehicle only. Survival rates were determined on day 14. Myocardial histopathology, cytokine levels in the heart by ELISA assay, and myocardial virus concentration were examined on day 6, and the expression levels of myocardial inducible nitric oxide synthase (iNOS) mRNA were measured by competitive polymerase chain reaction. The 14-day survival in mice treated with rhIL-10 was significantly higher (80%) than in the control group (30%, n=10 in each, P<0.05). rhIL-10 treatment significantly attenuated myocardial lesions and suppressed tumor necrosis factor-alpha and IL-2 in the heart. rhIL-10 treatment had little effect on myocardial virus concentration. The expression levels of myocardial iNOS mRNA were significantly decreased in the group treated with rhIL-10 (8.6+/-4.7 amol/mg total RNA in treated versus 26.5+/-7.1 amol/mg total RNA in control mice, P<0.05).

CONCLUSIONS

These findings provide new insights into the in vivo effects of IL-10 on viral infection and suggest a therapeutic effect of IL-10 on viral myocarditis.

Apical hypertrophic cardiomyopathy and hepatitis C virus infection

The familial form of hypertrophic cardiomyopathy (HCM) is attributed to mutations in the genes for contractile proteins, but the etiology of non-familial form remains unknown. This study was designed to examine the clinical features, histopathologic changes, and hepatitis C virus (HCV) genomes in patients with HCM associated with HCV infection. Anti-HCV antibody was present in the sera of 9 of 65 patients (13.8%) with HCM versus 2.41% in a control population of voluntary blood donors in Japan, a statistically significant difference (p<0.0001). Among these 9 patients, 6 had ace-of-spades-shaped deformities of the left ventricle with apical hypertrophy. Myocardial fibrosis was found in all patients, and mild cellular infiltration was observed in 5 patients. Type 1b HCV RNA was present in the sera of 5 of the 9 patients. The copy number of HCV was 5.5x10(3)-8.6x10(5) genomes/ml serum, and multiple clones of HCV were detected in the sera of each patient by an analysis of the hypervariable regions using fluorescent single-strand conformation polymorphism. Positive strands of HCV were found in the hearts of 5 patients, and negative strands in the hearts of 2 patients. A high prevalence of HCV infection was found in patients with HCM, particularly of the apical variety, suggesting that HCV is an important causal agent in the pathogenesis of the disease.

Pimobendan inhibits the production of proinflammatory cytokines and gene expression of inducible nitric oxide synthase in a murine model of viral myocarditis

OBJECTIVES

This study was designed to examine the effects of pimobendan in a murine model of viral myocarditis in relation to proinflammatory cytokine production and nitric oxide (NO) synthesis by inducible NO synthase (iNOS) in the heart.

BACKGROUND

Pimobendan has been recently confirmed to improve both acute and chronic heart failure. Since the modulation of myocardial necrosis and contractile dysfunction by various proinflammatory cytokines may be partially mediated by the production of nitric oxide, the effects of pimobendan on the production ofproinflammatory cytokines and NO were investigated in an animal model of viral myocarditis involving heart failure.

METHODS

DBA/2 mice were inoculated with the encephalomyocarditis virus. To observe its effect on survival up to 14 days, pimobendan (0.1 mg/kg or 1 mg/kg) or vehicles were given from the day of virus inoculation (day 0) orally once daily. The effects of pimobendan on histological changes, cytokine production, NO production and iNOS gene expression in the heart were studied in mice treated either with pimobendan, 1 mg/kg or with vehicles only, and sacrificed seven days after virus inoculation.

RESULTS

The survival of mice improved in a dose-dependent fashion such that a significant difference (p < 0.02) was found between the higher-dose pimobendan group (20 of 30 [66.7%]) and the control group (11 of 30 [36.7%]). Histological scores for cellular infiltration (1.1+/-0.1 vs. 2.0+/-0.0, p < 0.001), intracardiac tumor necrosis factor (TNF)-alpha (18.2+/-1.8 vs. 35.8+/-4.2 pg/mg heart, p < 0.001) and interleukin (IL)-1beta (9.3 +/-1.2 vs. 26.6+/-7.1 pg/mg heart, p < 0.01) were significantly lower in the mice given pimobendan versus those of the control mice. Interleukin-6 levels (7.1+/-0.8 vs. 9.2+/-1.9 pg/mg heart) were also lower in the mice treated with pimobendan. Furthermore, intracardiac NO production was significantly (p < 0.001) less in the pimobendan group (0.165+/-0.004 nmol/mg heart) than in the control group (0.291+/-0.051 nmol/mg heart), and intracardiac iNOS gene expression in the mice given pimobendan was 74% lower than it was in the control animals (p < 0.01).

CONCLUSIONS

These findings suggest that the beneficial effects of pimobendan in viral myocarditis are partially mediated by the inhibition of both proinflammatory cytokine production and NO synthesis by iNOS.

Denopamine, a beta1-adrenergic agonist, prolongs survival in a murine model of congestive heart failure induced by viral myocarditis: suppression of tumor necrosis factor-alpha production in the heart

OBJECTIVES

This study was designed to examine the effects of denopamine, a selective beta1-adrenergic agonist, in a murine model of congestive heart failure (CHF) due to viral myocarditis.

BACKGROUND

Positive inotropic agents are used to treat severe heart failure due to myocarditis. However, sympathomimetic agents have not been found beneficial in animal models of myocarditis.

METHODS

In vitro: The effects of denopamine on lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-alpha) production was studied in murine spleen cells. In vivo: Four-week-old DBA/2 mice were inoculated with the encephalomyocarditis virus (day 0). Denopamine (14 micromol/kg), denopamine (14 micromol/kg) with a selective beta1-blocker metoprolol (42 micromol/kg), or denopamine (14 micromol/kg) with metoprolol (84 micromol/kg) was given daily, and control mice received the vehicle only. Survival and myocardial histology on day 14 and TNF-alpha levels in the heart on day 6 were examined.

RESULTS

In the in vitro study, TNF-alpha levels in treated cells were significantly lower than in controls (p < 0.05). In the in vivo study treatment with denopamine significantly improved the survival of the animals (14 of 25 (56%) treated, vs 5 of 25 (20%) control mice), attenuated myocardial lesions, and suppressed TNF-alpha production (66.5+/-7.5 pg/mg of heart in treated mice vs 113.5+/-15.1 pg/mg of heart in control mice, mean+/-SE). There was a strong linear relationship between mortality and TNF-alpha levels (r=0.98, n=4, p < 0.05). These in vitro and in vivo effects of denopamine were significantly inhibited by metoprolol.

CONCLUSIONS

These results suggest that denopamine may exert its beneficial effects, in part, by suppressing the production of TNF-alpha via beta1-adrenoceptors.

Amiodarone inhibits production of tumor necrosis factor-alpha by human mononuclear cells: a possible mechanism for its effect in heart failure

BACKGROUND

Recent studies suggest that cytokines such as tumor necrosis factor (TNF)-alpha and interleukins (ILs) are capable of modulating cardiovascular function and that drugs used in the treatment of heart failure have various modulatory effects on the production of cytokines. This study was performed to examine the effects of amiodarone (a drug shown to be beneficial in some patients suffering from heart failure) versus other antiarrhythmic agents on the production of cytokines in vitro.

METHODS AND RESULTS

Human peripheral blood mononuclear cells (PBMC) were obtained from healthy volunteers. PBMC were cultured with 0.1, 1, and 10 micromol/L of amiodarone, quinidine, disopyramide, and lidocaine in the presence of lipopolysaccharide. After 24 hours' incubation, TNF-alpha, IL-1beta, and IL-6 were measured in the culture supernatants by an enzyme-linked immunosorbent assay. TNF-alpha production was inhibited by amiodarone but stimulated by quinidine in a concentration-dependent manner. Disopyramide and lidocaine tended to increase TNF-alpha production. IL-6 production was decreased by amiodarone in all concentrations but was increased significantly by disopyramide. Modulation of IL-1beta production by amiodarone was biphasic and significantly increased at a concentration of 10 micromol/L.

CONCLUSIONS

These previously unrecognized immunomodulatory effects of amiodarone may contribute to its beneficial effects in heart failure patients.

Modulation of cytokine production and protection against lethal endotoxemia by the cardiac glycoside ouabain

BACKGROUND

Recent studies have shown that cytokines are capable of modulating cardiovascular function and that some drugs used in the treatment of heart failure variably modulate the production of cytokines. To examine whether cardiac glycosides also modulate cytokine production, we evaluated the effects of ouabain on the production of cytokines in vitro and in vivo.

METHODS AND RESULTS

Human peripheral blood mononuclear cells (PBMC) were obtained from healthy volunteers. PBMC were cultured with or without ouabain in the presence or absence of lipopolysaccharide (LPS). Ouabain induced the production of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha in PBMC and induced mRNA of these cytokines, an induction apparently at the transcriptional level. Amiloride, staurosporin, and genistein inhibited cytokine production, and protein kinase C and tyrosine kinase appeared to be involved in the modulation of cytokine production induced by ouabain. However, when PBMC were stimulated with LPS, ouabain suppressed the production of IL-6 and TNF-alpha. To investigate whether ouabain modulates cytokine production in vivo, we evaluated the effects of ouabain in LPS-treated mice. Ouabain was found to protect against LPS-induced lethal toxicity in mice and decreased circulating IL-6 and TNF-alpha levels in vivo.

CONCLUSIONS

These previously unrecognized immunomodulating effects of a cardiac glycoside may explain either the beneficial or the detrimental effects of these drugs in heart failure patients.

Protective role of interleukin-12 in viral myocarditis

The co-ordinate action of several cytokines determines the nature, severity and duration of myocarditis. Interleukin (IL)-12 mediates a broad range of effects on both innate and acquired immunity. However, the in vivo role of IL-12 in viral myocarditis remains to be elucidated. To clarify the role of IL-12 in viral myocarditis, we treated mice inoculated with the encephalomyocarditis virus (EMCV), with recombinant IL-12 and neutralizing anti-IL-12 antibody. The successive administration of 10 ng of IL-12 from the day of virus inoculation to 5 days thereafter, reduced mortality, myocardial damage and viral replication in the heart tissue. The gene expression of IL-12p35 and IL-12p40 was enhanced in the hearts of EMCV inoculated mice. Treatment with neutralizing anti-IL-12 resulted in increased mortality of mice inoculated with EMCV. In conclusion, endogenous and exogenous IL-12 play protective roles in murine viral myocarditis.

[Usefulness of directional coronary atherectomy as a bail-out device for acute closure after coronary angioplasty]

The usefulness of directional coronary atherectomy (DCA) as a bail-out device for acute closure (reclosure) after percutaneous transluminal coronary angioplasty (PTCA) was evaluated. PTCA was performed in 1,023 patients (182 with acute myocardial infarction) between January 1993 and January 1994 in our hospital. Thirty-one patients (11 with acute myocardial infarction) suffered acute closure (reclosure) after PTCA. In six patients (five with acute myocardial infarction), DCA was performed as a rescue treatment for acute closure (reclosure). In three of these patients, angioscopy was performed before DCA, which demonstrated intimal tear and some thrombi although coronary angiography showed no evidence of thrombus. Bail-out DCA was successful in all six patients without complications. DCA is useful as a bail-out device for acute closure (reclosure) after PTCA when the thrombus is not massive.

Plasma levels of the monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 are elevated in patients with acute myocardial infarction

Cardiac inflammatory responses appear to play a pivotal role in scar formation after acute myocardial infarction. Monocyte chemotactic and activating factor (MCAF) monocyte chemoattractant protein-1 (MCP-1) is a cytokine with chemotactic activity for mononuclear phagocytes, but also for NK cells, T cells, mast cells, and basophils. To investigate the possible involvement of MCAF/MCP-1 in the pathogenesis, its course was studied in patients with acute myocardial infarction. Twenty-three consecutive patients with acute myocardial infarction and 18 patients with angina pectoris were studied. Cytokines were measured by enzyme-linked immunosorbent assay. Plasma levels of interleukin IL-1alpha, IL-1beta, and IL-2 were below the detection limit of our method. IL-6 and interferon-gamma were detected in 17.4%, and tumor necrosis factor-alpha in 13.0% of patients with acute myocardial infarction, but the frequency was not statistically significantly different from that in angina pectoris. The plasma level of MCAF/MCP-1 in myocardial infarction tended to increase at 3 h after the onset of chest pain (133 +/- 19 pg/ml, P= 0.06) and was significantly elevated at 9 h (143 +/- 20 pg/ml) when compared with that in angina pectoris (87 +/- 6 pg/ml, P<0.05). The MCAF/MCP-1 level remained increased during the 24-hours observation period (P<0.01), and maximum level (168 +/- 13 pg/ml) was seen at 24 hour. The level of MCAF/ MCP-1 correlated significantly with the plasma level of another chemokine, IL-8, at 12 h after the onset of chest pain (r=0.51, P<0.05), suggesting that common stimuli mediate the release of both cytokines in myocardial infarction. The identification of MCAF/MCP-1 as an inflammatory mediator in acute myocardial infarction suggests that mononuclear phagocytes may play an important role in the early stage of the disease.

Detection of hepatitis C virus RNA from the heart of patients with hypertrophic cardiomyopathy

We investigated hepatitis C virus (HCV) infection in 35 patients with hypertrophic cardiomyopathy and 40 patients with ischemic heart disease who were consecutively admitted to our hospital. Frequency of positive anti-HCV antibody was significantly higher in patients with hypertrophic cardiomyopathy (6 of 35 patients, 17.1%) than that in patients with ischemic heart disease (1 of 40 patients, 2.5%, p = 0.036). In three of these six patients with hypertrophic cardiomyopathy, HCV RNA was detected in myocardial tissue. In two of these three patients, HCV RNA was detected from biopsy and autopsy specimens of the ventricles, but not in the serum, suggesting that HCV may replicate in myocardial tissue and may be relevant to ventricular hypertrophy. Thus, HCV infection may play a role in the development of hypertrophic cardiomyopathy.

Increased circulating hepatocyte growth factor in the early stage of acute myocardial infarction

We measured serum hepatocyte growth factor (HGF) in patients with acute myocardial infarction, angina pectoris, and other heart diseases. In patients with acute myocardial infarction, blood was collected at the time of admission. Serum HGF was elevated within 3 hours in 8 of 10 patients (80%) with acute myocardial infarction after onset of chest pain (9.4 +/- 3.2 ng/mL, mean +/- SEM, values in normal subjects <0.39 ng/mL). Mean value of serum HGF was 11.0 +/-2.6 ng.mL (n=11) in patients who admitted to the hospital between 6 and 9 hours and 13.1 +/- 5.7 ng.mL between 12 and 24 hours after onset. Elevated HGF levels were significantly more frequent than those of creatine kinase within 3 hours, and elevated levels correlated well with those of serum creatine kinase at 6-9 hours after onset of acute myocardial infarction. No increase in serum HGF value was found in patients with angina pectoris or other heart diseases. Thus, measurement of HGF is a sensitive method for early diagnosis of acute myocardial infarction.

Epidemiological study of Yersinia enterocolitica and Yersinia pseudotuberculosis infections in Shimane Prefecture, Japan

In Shimane Prefecture, Japan, 175 Yersinia enterocolitica isolates from 6,479 stools and 347 appendixes of patients were separated into biotype 3B (VP-, sorbose-, inositol-) serotype O3 phage type II (22 isolates); biotype 4 (84 isolates), biotype 4 (ornithine-) (16 isolates) and biotype 4 (maltose-) (9 isolates) of serotype O3 phage type VIII, biotype 2 serotype O9 (1 isolate) and biotype 1 (43 isolates). This may be the first documentation of isolation of Y. enterocolitica biotype 3B serotype O3 phage type II from patients. Twenty-three Yersinia pseudotuberculosis isolates from stools of 23 patients were grouped into serotypes IB (13 isolates), III (2 isolates) and IVB (8 isolates). Clinical manifestations were more numerous in Y. pseudotuberculosis infections than Y. enterocolitica O3 infections. Y. enterocolitica O3 was more frequently isolated between summer and autumn but Y. pseudotuberculosis and Y. enterocolitica biotype 1 were isolated between winter and spring. Secondary infection with Yersinia among close family members was frequent. Y. enterocolitica O3 and Y. pseudotuberculosis infected persons excreted 10(4) to 10(9) viable cells per g stool during 27 and 19 days, but Y. enterocolitica biotype 1 strains were detected only when using enrichment techniques. Serological responses were not observed in under 2 year old persons infected with Y. enterocolitica O3.