Preliminary investigation of the feasibility of a long-term but low-frequency preventive intervention for depression in Japanese high schools

AIM

We explored the feasibility of a long-term but low-frequency psychological preventive intervention in a high school setting.

BACKGROUND

High school students may experience depression; psychological interventions to improve social and cognitive skills may be useful to decrease such depression. A long-term but low-frequency intervention may be feasible in this setting because of its minimal time demands and lack of need for specialist human resources DESIGN: We conducted a single-arm longitudinal descriptive study with an intervention applied six times over 2 years in one high school.

METHOD

We conducted a psychological preventive intervention with 94 high school students in one school for 2 years (April 2014 to March 2016). This intervention aimed to improve social and cognitive skills. We measured social skills, cognitive distortion, and depression five times during the 2-year period, through a self-report scale.

RESULTS/FINDINGS

Scores for maintaining relationship skills tended to increase over the 2 years. However, depression did not decrease over the intervention period.

CONCLUSION

Although our research did not include control conditions and the intervention did not decrease depression, the six-session programme for high school adolescents improved an aspect of social skills that is a preventive factor against depression.

Impact of repetitive thought and processing mode on goal striving

BACKGROUND AND OBJECTIVES

Striving to attain personal goals is important for maintaining well-being. Previous research indicates that repetitive thoughts can influence the affect and cognition associated with personal goal strivings. Repetitive thought in the concrete-experiential processing mode improves affect and cognition after a negative event more than does repetitive thought in the abstract-analytic processing mode. We extend this prior work by examining whether repetitive thought directly influences the maintenance of personal goal strivings through a longitudinal survey.

METHODS

In Study 1, we examined the daily maintenance effect of repetitive thought on personal goal strivings using a multilevel analysis of 29 participants who reported their thoughts and goal strivings daily for one week. In Study 2, participants (N = 131) reported their thoughts and goal strivings over 10 weeks, and we examined the maintenance effect of repetitive thought on personal goal strivings every two weeks.

RESULTS

Highly repetitive thought in the abstract-analytic processing mode decreased the maintenance of short-term personal goal strivings in individuals with difficult goals. However, highly repetitive thought in the concrete-experiential processing mode increased the maintenance of long-term personal goal strivings in individuals with difficult goals.

LIMITATIONS

The study participants were university students; therefore, we cannot generalize the results to clinical populations or other age groups.

CONCLUSION

Interventions that increase repetitive thought in the concrete-experiential processing mode may be effective in facilitating long-term goal strivings in individuals attempting to overcome difficult situations and achieve important personal goals.

Identification of putative gene encoded on ORF16 of the 81 kb contig of Arabidopsis thaliana chromosome III as alpha-mannosidase

We isolated cDNA corresponding to open reading frame (ORF) 16 of the 81 kb contig of Arabidopsis thaliana chromosome III [Quigley., Nucleic Acids Res., 24, 4313-4318 (1996)] and expressed alpha-mannosidase activity in tobacco suspension-cultured cells, which revealed that ORF16 encodes alpha-mannosidase. We also suggested that Arabidopsis harbors three genes encoding alpha-mannosidase by homology search against the database.

Inducing peripheral sympathetic nerve activity by therapeutic electrical stimulation

PURPOSE

To examine whether the activity of peripheral sympathetic nerves in animals with spinal cord injury can be controlled using therapeutic electrical stimulation.

METHODS

The spinal cords of 6 Wistar rats were severed at T12/T13 disk level and were given continuous therapeutic electrical stimulation. Microneurography was used to record sympathetic nerve activity at 24, 48, and 72 hours after severing the spinal cord.

RESULTS

Integrated values of muscle sympathetic nerve activity after 72 hours of therapeutic electrical stimulation revealed significantly larger potentials on the stimulated side than the non-stimulated side. Skin sympathetic nerve activity showed no difference between the 2 sides.

CONCLUSION

Therapeutic electrical stimulation was found to have a facilitatory effect on the muscle sympathetic nerve activity, whereas regulatory function was activated by the sympathetic nerves.

Diagnostic utility of waveform analysis of compound muscle action potentials for carpal tunnel syndrome

PURPOSE

To determine the diagnostic utility of waveform analysis of compound muscle action potentials (CMAP) for carpal tunnel syndrome (CTS).

METHODS

A total of 131 hands in 71 patients diagnosed with CTS (grouped according to severity) and 80 hands in 44 normal subjects were evaluated using nerve conduction test through the carpal tunnel combined with waveform analysis of CMAP.

RESULTS

Compared to normal subjects, the sensory nerve conduction velocity and mean frequency of the CMAP waveform were significantly reduced in patients with CTS. Compared with distal motor latency and sensory nerve conduction velocity, the mean frequency of the CMAP decreased significantly with increasing clinical severity.

CONCLUSION

This study suggests that waveform analysis of CMAP is of diagnostic value in CTS, and is also of value in objective evaluation of postoperative recovery of carpal median nerve dysfunction.

Sympathetic skin response in patients with spinal cord injury

PURPOSE

To assess the effectiveness of sympathetic skin response in evaluating peripheral sympathetic nerve activity of patients with spinal cord injury, and to report on the basic properties of sympathetic skin response.

METHODS

Sympathetic skin response evoked by electrical stimulation was recorded from the palms and soles of healthy volunteers and patients with spinal cord injury.

RESULTS

Sympathetic skin response was recorded in 17 healthy volunteers and 14 patients with spinal cord injury. Of the 4 waveforms, the shortest latency was obtained from the palm; the sympathetic skin response was 1.2 to 1.4 ms at all stimulated sites, 1.9 to 2.0 ms at the sole, with a difference of about 0.6 ms between the palm and the sole. None of the patients with spinal cord injury responded at either the upper or lower limbs. In patients with a thoracic cord injury, some responded at the upper limbs but none at the lower limbs; some responded at neither upper nor the lower limbs; and some responded at both upper and lower limbs. The conducting pathway of sympathetic skin response in the spinal cord for the upper limbs descends to the upper thoracic cord (T4-6), and the conducting pathway for the lower limbs departs from the spinal cord at the lower thoracic cord (T9-10).

CONCLUSION

It appears that sympathetic skin response should be used for the evaluation and morbid investigation of the functional abnormalities of the sympathetic nervous system in patients with spinal cord lesions such as spinal cord injuries, cervical spondylosis, and spinal canal stenosis.

The relationship between nerve conduction study and clinical grading of carpal tunnel syndrome

PURPOSE

To conduct a median nerve conduction study on patients with carpal tunnel syndrome and investigate the relationship between nerve conduction study parameters and clinical grading.

METHODS

A nerve conduction study was performed on 60 upper limbs of 37 patients with idiopathic carpal tunnel syndrome, and the relationship between the clinical grade and various study parameters was assessed.

RESULTS

The amplitude of the sensory nerve action potential and the motor nerve action potential differed according to clinical grading, but this pattern was not seen for sensory nerve conduction velocity, motor nerve conduction velocity, or motor nerve terminal latency and clinical grading.

CONCLUSION

The amplitude of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters for assessing clinical grading based on nerve conduction velocity.

Effect of Chlamydia pneumoniae infection on coronary flow reserve and intimal hyperplasia after stent implantation in patients with angina pectoris

OBJECTIVES

Chlamydia pneumoniae (C. pneumoniae) has been detected in tissue from coronary atherosclerotic vascular lesions and may be involved in the pathogenesis of atherosclerosis. However, the effect of prior C. pneumoniae infection on coronary intimal hyperplasia after stent implantation and on coronary microvascular function is unknown.

METHODS

Seventy-three patients with stable angina pectoris and a single de novo coronary lesion were studied prospectively. All patients underwent successful coronary angioplasty and stent implantation for the stenotic lesion. Blood samples were tested for prior C. pneumoniae infection before the procedure, and patients were divided into two groups: Seropositive and seronegative. Coronary flow reserve was measured in the non-stenotic coronary vessel before angioplasty, and quantitative coronary arteriography was performed at the stent implantation site before angioplasty and 6 months later in all patients.

RESULTS

Coronary flow reserve in the non-stenotic vessel was significantly lower in the seropositive group than in the seronegative group (2.51 +/- 0.35 vs 2.76 +/- 0.43, p < 0.05). The minimum luminal diameter was smaller and late loss was greater in the seropositive group than in the seronegative group (minimum luminal diameter: 1.52 +/- 0.59 vs 1.91 +/- 0.79 mm, p < 0.05, late loss: 1.17 +/- 0.55 vs 0.76 +/- 0.67, p < 0.05). However, there was no significant difference in the restenosis rate or target lesion revascularization rate between the two groups.

CONCLUSIONS

Prior C. pneumoniae infection may accelerate intimal hyperplasia after stent implantation and impair coronary microvascular function in the non-stenotic coronary vessels.

Localization of nitric oxide synthase activity in unfertilized oocytes and fertilized embryos during preimplantation development in mice

Changes in the activities of nitric oxide synthase (NOS) during embryonic development, and the distribution of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) isoforms were examined in unfertilized mouse oocytes at the second meiotic metaphase (MII) stage and in fertilized mouse embryos during preimplantation development. In addition, the effects of NOS inhibitors on mouse preimplantation development in vitro were investigated. The activities of NOS in MII oocytes and fertilized embryos during the preimplantation period were determined by NADPH-diaphorase staining. Although NOS activity was detected in unfertilized MII oocytes, the intensity of staining was much weaker than that of fertilized embryos at the one-cell stage. There was a decrease in NOS activity in embryos from the four-cell to the eight-cell stage; however, NOS activity increased again in embryos at the morula stage, particularly in the inner cell population. In the expanded blastocysts, staining was confined to the inner cell mass. Immuno-cytochemical staining showed that eNOS and iNOS were expressed in the cytoplasm of oocytes and embryos during the preimplantation period, and eNOS was also distributed in the nuclei of the embryos. When one-cell embryos were treated with 1 mmol N(omega)-nitro-L-arginine methyl ester (L-NAME) l(-1), their development in vitro was arrested at the two-cell stage. This inhibition of development was overcome by the addition of 1 mmol L-arginine l(-1) to the medium. These observations indicate that nitric oxide plays an important role as a diffusible regulator of cell proliferation and differentiation, especially at the developmental transition from the two-cell to the four-cell stage during preimplantation development of mice.

Tributyltin interacts with mitochondria and induces cytochrome c release

Although triorganotins are potent inducers of apoptosis in various cell types, the critical targets of these compounds and the mechanisms by which they lead to cell death remain to be elucidated. There are two major pathways by which apoptotic cell death occurs: one is triggered by a cytokine mediator and the other is by a mitochondrion-dependent mechanism. To elucidate the mechanism of triorganotin-induced apoptosis, we studied the effect of tributyltin on mitochondrial function. We found that moderately low doses of tributyltin decrease mitochondrial membrane potential and induce cytochrome c release by a mechanism inhibited by cyclosporine A and bongkrekic acid. Tributyltin-induced cytochrome c release is also prevented by dithiols such as dithiothreitol and 2,3-dimercaptopropanol but not by monothiols such as GSH, N-acetyl-L-cysteine, L-cysteine and 2-mercaptoethanol. Further studies with phenylarsine oxide agarose revealed that tributyltin interacts with the adenine nucleotide translocator, a functional constituent of the mitochondrial permeability transition pore, which is selectively inhibited by dithiothreitol. These results suggest that, at low doses, tributyltin interacts selectively with critical thiol residues in the adenine nucleotide translocator and opens the permeability transition pore, thereby decreasing membrane potential and releasing cytochrome c from mitochondria, a series of events consistent with established mechanistic models of apoptosis.

Transmembrane TNF (pro-TNF) is palmitoylated

Human transmembrane tumor necrosis factor (pro-TNF) was examined for protein acylation. The cDNA encoding pro-TNF was expressed in both COS-1 cells and Sf9 cells and metabolic labeling with [(3)H]myristic or [(3)H]palmitic acid was attempted. The 17 kDa mature TNF secreted from the transfected cells was not labeled, whereas the 26 kDa pro-TNF was specifically labeled with [(3)H]palmitic acid. The [(3)H]palmitic acid labeling of pro-TNF was eliminated by treatment with hydroxylamine, indicating that the labeling was due to palmitoylation of a cysteine residue via a thioester bond. Site-directed mutagenesis of the two cysteine residues residing in the leader sequence of pro-TNF demonstrated that palmitoylation of pro-TNF occurs solely at Cys-47, located at the boundary between the transmembrane and cytoplasmic domains of pro-TNF. Thus, pro-TNF interacts with the plasma membrane via both its proteinaceous transmembrane domain and a lipid anchor.

Sympathetic skin response evoked by respiratory stimulation as a measure of sympathetic function

OBJECTIVES

To compare respiratory and electrical methods of evoking a sympathetic skin response (SSR).

METHODS

SSRs evoked by both electrical and respiratory stimulation were recorded from the palms of 47 healthy volunteers. Expiration and inspiration were used as separate stimuli. The correlation coefficients between the amplitude and latency of the SSR from the palm electrodes and the various components of heart rate variability were calculated.

RESULTS

Waveform patterns of the SSRs obtained from electrical stimulation showed varied responses to and habituation to this type of stimulation. On the other hand, no subjects showed a phase change in SSR waveform patterns between the first and last expiratory stimuli. The potentials recorded after expiratory stimulation had significantly greater amplitudes than those recorded after electrical stimuli. The low frequency component of heart rate variability induced by expiratory stimulation was significantly greater than that induced by electrical stimulation. The SSR may also correlate strongly with the change of respiratory rate since a more rapid pressure change occurs during expiratory movement than during inspiratory movements.

CONCLUSIONS

The SSR evoked by expiratory stimulation is more reliable than either electrical stimulation or inspiratory stimulation for determining sympathetic function.

Ascitic fluid cytology of adenosarcoma of the ovary: a case report

Extrauterine adenosarcoma is very rare and originates in the ovary, adnexa, or myometrium. Cytologic study of ascites is very important to determine clinical staging of malignant ovarian tumors and provide adequate therapy for recurrence. The cytomorphologic features of adenosarcoma have been only rarely described. A 77-yr-old woman visited a hospital with a complaint of lower abdominal pain for 1 mo. A tumor originating from the right adnexa in the pelvis, and involving the rectum, was found in surgery. In the ascitic fluid cytology, a few dispersed tumor cells with large cytoplasm and nuclei were oval-shaped, with nuclear invagination. The chromatin was finely granular; one or two nucleoli were conspicuous. To our knowledge, this is the fifteenth reported case of adenosarcoma of the ovary, and there have been no prior reports describing the cytological features of ascitic fluid cells in adenosarcoma of the ovary.

Hypoxic induction of adrenomedullin in cultured human umbilical vein endothelial cells

OBJECTIVES

The current study evaluated the hypoxic induction of adrenomedullin gene expression and secretion, and its mechanism in cultured human umbilical vein endothelial cells (HUVEC).

METHODS

HUVEC were exposed to hypoxia or normoxia as controls for 1 to 24 h. Using Northern blot analysis and a radioimmunoassay, we evaluated adrenomedullin expression in HUVEC. The transcriptional component of adrenomedullin gene regulation was assessed by nuclear run-off experiments, and adrenomedullin mRNA half-life was measured by actinomycin D experiments.

RESULTS

We found that hypoxic conditions (1-3% oxygen) significantly increased adrenomedullin mRNA and protein in HUVEC. This increase was inversely proportional to oxygen tension and was reversible upon re-exposure to a 21% oxygen environment Nuclear run-off experiments revealed the enhanced transcriptional rate of adrenomedullin gene. Next, actinomycin D experiments revealed the enhanced adrenomedullin mRNA stability.

CONCLUSIONS

These results indicate that hypoxia increases adrenomedullin gene expression and secretion in HUVEC by transcriptional and post-transcriptional mechanisms. Hypoxic induction of adrenomedullin may play a pathophysiological role in the vascular systems.

[Effect of long-term cilostazol administration on coronary flow velocity and coronary flow reserve]

Cilostazol, a novel potent inhibitor of phosphodiesterase, increases coronary flow. The effects of cilostazol on coronary flow velocity and coronary flow reserve were studied in 103 patients with coronary artery disease who underwent coronary angiography. Cilostazol 200 mg/day was administered for 3 months (31 patients) or 6 months (37 patients), and coronary flow reserve were measured before and after the cilostazol administration. Coronary flow reserve were measured twice at an interval of 6 months in the control group (35 patients). The Doppler guide wire was advanced into the coronary artery with no significant vessel stenosis. After obtaining continuous baseline coronary flow velocity, an intracoronary infusion of papaverine (10 mg) was performed to measure coronary flow reserve. There were no significant differences in coronary flow velocity just before intracoronary papaverine infusion between the initial and follow-up studies in any of the 3 groups. Coronary flow reserve increased significantly after cilostazol administration in the 3 months and 6 months groups compared with before administration (3 months group: 2.8 +/- 0.8 vs 2.4 +/- 0.9, p < 0.05; 6 months group: 2.8 +/- 1.0 vs 2.4 +/- 0.7, p < 0.01). However, there was no significant difference in coronary flow reserve in the control group between follow-up and initial studies (2.7 +/- 0.8 vs 2.5 +/- 0.8, NS). In conclusion, the long-term oral administration of cilostazol for 3 or 6 months improves coronary flow reserve.

Acute effects of nicotine content in cigarettes on coronary flow velocity and coronary flow reserve in men

We investigated the acute effects of smoking on coronary flow reserve in terms of the nicotine content of cigarettes in 21 smokers. Coronary flow velocity was measured with a Doppler flow wire. Subjects smoked cigarettes containing >1 mg nicotine (n = 8, group 1) or <1 mg (n = 6, group 2). Subjects in the control group mimicked smoking without a cigarette (n = 7). Coronary flow reserve decreased after smoking in group 1, but not in group 2 or the control group. This reduction may have mediated nicotine or some other unknown substances influenced by smoking.

[Impaired coronary flow reserve due to long-term smoking recovers after quitting]

Cigarette smoking is a major risk factor for coronary artery disease. The present study examined whether impaired coronary flow reserve by smoking can be recovered by quitting. Coronary flow velocity was measured by Doppler guide wire during coronary angiography and coronary flow reserve was determined by injecting 10 mg intracoronary papaverine in 45 patients who were present or former smokers. Twenty-three patients were smoking more than 800 cigarettes/day x years and 22 patients less than 800, and 13 patients had smoked more than 800 but had quit smoking at least for 5 years. None of the patients had any significant coronary stenosis in the left anterior descending artery where the Doppler probe was positioned, nor any coronary risk factors except smoking. Twenty-six non-smokers served as control subjects. There was no difference in the coronary flow reserve between controls and light smokers (3.3 +/- 0.7 vs 3.3 +/- 1.0), but it was significantly reduced in heavy smokers (2.6 +/- 0.8) compared to controls or light smokers (p < 0.05, p < 0.05, respectively), There was no significant difference in coronary flow reserve between controls, light smokers and ex-smokers (3.3 +/- 1.2). These results suggest that the deteriorating effect on the coronary flow reserve by smoking is corrected after its cessation.

Inhibition of rat vascular smooth muscle proliferation in vitro and in vivo by bone morphogenetic protein-2

Vascular proliferative disorders are characterized by the proliferation of vascular smooth muscle cells (SMCs) and excessive extracellular matrix synthesis. We found that bone morphogenetic protein-2 (BMP-2) inhibited serum-stimulated increases in DNA synthesis and cell number of cultured rat arterial SMCs in a fashion quite different from that in the case of transforming growth factor-beta1 (TGF-beta1). In addition, TGF-beta1 stimulated collagen synthesis in SMCs, whereas BMP-2 did not. In an in vivo rat carotid artery balloon injury model, the adenovirus-mediated transfer of the BMP-2 gene inhibited injury-induced intimal hyperplasia. These results indicate that BMP-2 has the ability to inhibit SMC proliferation without stimulating extracellular matrix synthesis, and suggest the possibility of therapeutic application of BMP-2 for the prevention of vascular proliferative disorders.

Effect of time interval between two balloon inflations on ischemic preconditioning during coronary angioplasty

Ischemic preconditioning, defined as a reduction in myocardial ischemia caused by repeated brief episodes of coronary occlusions, is observed during percutaneous transluminal balloon angioplasty (PTCA). To elucidate the effects of the length of the interval between consecutive balloon inflations on ischemic preconditioning during PTCA, we examined 62 patients with chronic stable angina (48 males and 14 females; mean age 62 +/- 10 yr). PTCA was performed on the left anterior descending artery lacking in collateral vessels. A 2-min balloon inflation was performed twice and the extent of ST segment elevation in the electrocardiogram and the severity of chest pain (scored from 0 to 10) for each inflation were determined and compared. Patients were divided into three groups according to the interval between the two inflations: 1 min, Group 1; 2 min, Group 2; and 5 min, Group 5. In Groups 2 and 5, ST-segment elevation was significantly decreased during the second balloon inflation, as compared with that during the first inflation (P < 0.01, P < 0.001). A significant decrease was also observed in the severity of chest pain (P < 0.05, P < 0.01). However, Group 1 showed no significant decrease in ST-segment elevation or severity of chest pain between the first and second inflations. ST-segment elevation and chest pain were reduced to a greater extent in Group 5 than in Group 2. Results suggest that an interval of more than 2 min between balloon inflations is required to achieve ischemic preconditioning during PTCA.

Lysophosphatidylcholine transduces Ca2+ signaling via the platelet-activating factor receptor in macrophages

To clarify the molecular mechanism underlying the lysophosphatidylcholine (LPC) signaling, we studied the effect of LPC on the intracellular free calcium concentration ([Ca2+]i) in murine peritoneal macrophages. LPC when added alone induced biphasic elevation of [Ca2+]i, which consisted of a rapid increase followed by sustained elevation. LPC, when added with equimolar cholesterol, induced only the rapid increase in [Ca2+]i, which was blocked by WEB-2086, a selective platelet-activating factor (PAF) receptor antagonist. These results suggest LPC exerts a specific Ca2+ signaling. The sustained elevation reflected the cell lysis. Furthermore, we confirmed its pathway in a more specific manner using cloned PAF receptors expressed in Chinese hamster ovary cells. LPC induced an elevation of [Ca2+]i in a concentration-dependent manner only when the PAF receptor had been expressed, and the elevation of [Ca2+]i was blocked by WEB-2086. Taken together, LPC transduces Ca2+ signaling via the PAF receptor. Activation of the PAF receptor by LPC may indicate its novel important role in the pathogenesis of atherosclerosis.

A study of the normal values and habituation phenomenon of sympathetic skin response

Sympathetic skin response (SSR) has been developed recently as a method of capturing the autonomic nerve response as a parameter of the sweat gland function. In this study, our aim was to obtain the normal values with regard to both amplitude and latency of SSR from 50 healthy subjects and to find out the habituation mode, which is one of the most characteristic phenomena of SSR. The measurements were recorded from the hand and foot by rectangular waveform electric stimulation. The correlation coefficient regarding hand and foot leads, amplitude, and latency were studied at normal values. The result was that no significant difference could be observed between the left and right leads with regard to amplitude and latency recorded from the hand and foot leads. However, between hand and foot leads, a significant difference was observed for both latency and amplitude. As for the habituation, electric stimulations were also applied to 20 healthy subjects (age range, 21-62 yr) in the same manner as that used in taking the normal values. For the latency and amplitude of the response in association with the stimulation trials (Rn), the mean values of the hand as well as the foot were determined by averaging the values recorded from both hands and both feet of the 20 subjects. These values were designated as the latency and the amplitude of the hand and foot from R1 to R15. The changes observed in response to the transition in the number of stimulations were statistically evaluated as a gradual decrease in the amplitude. This phenomenon is thought to be a result of learning. On the basis of the 15 consecutive stimulations, a decrease in amplitude to the 7th and 8th stimulations and constancy in the results thereafter was observed, although minor differences in the results were apparent between the hand and foot leads.

[Effects of the time interval between the first and second balloon inflations on ischemic preconditioning during percutaneous transluminal coronary angioplasty]

Ischemic preconditioning is an attenuation of myocardial ischemia by repeated brief coronary occlusions observed during percutaneous transluminal coronary angioplasty (PTCA). The effects of the time delay between balloon inflations during PTCA on ischemic preconditioning were investigated in 48 patients with chronic stable angina but no rich collateral vessels. After successful predilatation, two 2-min balloon inflations were performed and the ST segment elevation in the electrocardiogram and chest pain were measured during each balloon inflation and compared. Patients were divided into three groups according to the interval between balloon inflations; 1 min (I1), 2 min (I2) and 5 min (I5). There were no significant differences in ST elevation (3.4, 3.2 and 3.7 mm) and chest pain during the first balloon inflation between these three groups. ST elevation and chest pain were decreased in groups I2 and I5 (2.6 and 2.8 mm) during the second balloon inflation compared with those during the first balloon inflation. However, there was no significant difference in ST elevation and chest pain during the first and second (3.7 mm) balloon inflations in group I1. ST elevation and chest pain were reduced more in group I5 than in I2. These results suggest that an interval of more than 2 min between balloon inflations is necessary to obtain the effect of ischemic preconditioning during PTCA.

Rapid induction of vascular endothelial growth factor expression by transient ischemia in rat heart

Vascular endothelial growth factor (VEGF or vascular permeability factor), a direct-acting, endothelial cell-specific mitogen, has been suggested to be involved in development and maintenance of vasculatures in tumor neovascularization and in normal tissues. To investigate possible roles of VEGF in ischemic hearts, we studied induction of VEGF mRNA by ischemia and hypoxia using coronary artery-ligated hearts in vivo and perfused hearts and cultured myocardial cells in vitro. VEGF mRNA was potently induced by ischemia in the heart in vivo. In perfused hearts, maximum expression was rapidly induced (within 30 min) by transient reversible ischemia (5-10 min of ischemia) and lasted at least 3 h. Induction was also caused by hypoxia, which was confirmed in perfused hearts and cultured myocardial cells. These results suggest that induction of VEGF mRNA is upregulated by oxygen deprivation in the heart and that not only infarction but also chronic ischemia in the clinical setting could induce VEGF as a potent angiogenesis factor to stimulate coronary collateral formation.

Adenosine as an endogenous mediator of hypoxia for induction of vascular endothelial growth factor mRNA in U-937 cells

Adenosine induced by hypoxia exerts various effects via different types of receptors. Recently, hypoxia was shown to be a strong inducer of vascular endothelial growth factor, a secreted endothelial cell specific mitogen. In this report, we studied on effects of adenosine on inducibility of VEGF and possible mediation of hypoxia for its induction in U-937 cells. Hypoxia induced expression of VEGF mRNA with an early peak at 1 hour. 5'-N-ethylcarboxamidoadenosine, an adenosine analog, strongly induced VEGF mRNA, which was inhibited by 3,7-dimethyl-1-propargylxanthine (DMPX), an A2-antagonist. The hypoxic induction was inhibited by adenosine deaminase, 7-(beta-hydroxyethyl)theophylline, a non-selective adenosine receptor antagonist and DMPX. These results suggest that the hypoxic induction of VEGF mRNA is mediated by adenosine via A2-receptor in U-937 cells.

Effect of long-term cyclic mechanical load on protein synthesis and morphological changes in cultured myocardial cells from neonatal rat

We studied the effect of prolonged cyclic mechanical stimulation on protein synthesis and morphological changes in cultured cardiac myocytes isolated from 3-day-old neonatal rats to develop an in vitro model for cardiac hypertrophy induced by a mechanical load. Myocardial cells were cultured on deformative culture plates with M-199 culture medium in the presence or absence of fetal calf serum (FCS), and a cyclic mechanical load was applied for 2 hours up to 15 days. Mechanical stimulation for 2 hours increased the 14C-phenylalanine incorporation rate of myocardial cells, both in the absence and presence of FCS or when the myocardial cells were either beating or arrested with tetrodotoxin. The incorporation rate always increased by mechanical stimulation during 15 days of cell culture as compared to cells that sustained no mechanical stress. The cell size and protein content, which increased gradually with mechanical stimulation and reached a maximum at 10 days, were even greater in the presence of FCS. Within 10 days myocardial cells had aligned in the direction of the maximal cyclic mechanical load. In these cells electron microscopy revealed an increase in the number of myofilaments associated with the development of mitochondria as recognized in the adult myocardial cells. These results indicate that long-term cyclic mechanical loading of cultured myocardial cells may be a good in vitro model for the study of cardiac hypertrophy.

High incidence of mitral and tricuspid regurgitation in patients with Graves' disease detected by two-dimensional color Doppler echocardiography

With two-dimensional (2D) color Doppler echocardiography, the cardiac and valvular function of 24 consecutive patients with a history of Graves' disease (17 were hyperthyroid and 7 were euthyroid at the time of the examination) were evaluated. The incidences of mitral regurgitation (MR), tricuspid regurgitation (TR) and MR plus TR were significantly higher in the patients with Graves' disease than in the age-matched control group of patients without this disease. In the patients who had signs of congestive heart failure (CHF) while they were hyperthyroid, a significantly higher incidence of severe TR was observed. This is the first report of a 2D color Doppler echocardiography study on the incidences of TR and/or MR in patients with Graves' disease. Our data indicate that in Graves' disease valvular dysfunction can be caused by systemic disorders and that severe TR is a possible risk factor for CHF.

Pathological analysis of the right ventricular hypertrophy and ventricular interdependence in autopsied hearts with cor pulmonale and pulmonary hypertensive rat hearts

Thirty autopsied hearts with cor pulmonale and 20 experimental pulmonary hypertensive rat hearts were analysed macroscopically and histometrically. In autopsied hearts with cor pulmonale, right ventricle dilatated in oblique length, and right ventricular wall thickness significantly increased at pulmonary conus (PC) and posterior wall of right ventricle (RVP) compared with that at anterior wall of right ventricle (RVA). Mean diameters of myocardial fibers at PC, RVP, right ventricular side of interventricular septum (IVR) and mid layer of interventricular septum (IVM) significantly increased compared with that at mid layer of left ventricular wall (LVM). The wet weight and the diameter of myocardial fibers in right ventricle (RV) significantly correlated with those in interventricular septum (IVS). In pulmonary hypertensive rats, wet weights of RV and IVS increased significantly with the elevation of mean pulmonary arterial pressure. The diameters of myocardial fibers increased at RVP, RVA, IVR and IVM. There was no significant cardiac hypertrophy in left ventricle (LV), either microscopically or macroscopically. These results suggest that IVS responded morphometrically rather than in concord with RV but not with LV in the cor pulmonale heart.

Risk factors for the complication of cerebral infarction in Japanese patients with acute myocardial infarction

The incidence and risk factors for cerebral infarction in Japanese patients with acute myocardial infarction were evaluated. Seven (5.0%) of 140 patients with acute myocardial infarction suffered from cerebral infarction during their initial hospitalization. The incidence was slightly higher than those reported in Western countries. Anterior wall myocardial infarction and a past history of cerebrovascular disease were considered to be probable risk factors for the complication. A beneficial effect of anticoagulant therapy in preventing cerebral infarction in cases of acute myocardial infarction with those risk factors is suggested.

Biochemical mechanisms of cardiac hypertrophy

Rapid cardiac growth in adult rats and neonatal pigs involves more efficient use of existing components of the protein synthesis pathway and synthesis of new ribosomes and mRNA to increase the capacity for protein synthesis. Greater efficiency of synthesis can be induced by mechanical perturbations that stretch the ventricular wall, including increased cardiac work and increased ventricular pressure development in beating hearts, and increased aortic and intraventricular pressure in arrested-drained hearts. The biochemical signal linking stretch to more efficient protein synthesis has not been identified. Preferential synthesis of new ribosomes occurs in the first two hours of exposure of Langendorff preparations to high aortic pressure or within four hours after injection of thyroid hormone into normal rats. The rate of protein degradation is either accelerated or unchanged in hypertrophing hearts but is inhibited by induction of cardiac work or high aortic pressure in Langendorff preparations. Overall, increased capacity for, and efficiency of, protein synthesis are the major factors accounting for cardiac growth.

Aortic perfusion pressure, protein synthesis, and protein degradation

An increase in aortic pressure from 60 to 120 mm Hg accelerated protein synthesis and inhibited protein degradation in isolated rat hearts perfused as Langendorff preparations. This elevation of aortic pressure raised intraventricular pressure development, coronary flow, and oxygen consumption. The effect of aortic pressure on protein turnover was dissociated from intraventricular pressure development, contractile activity, and oxygen consumption by use of beating-drained and arrested-drained preparations. Results of other experiments argued against coronary flow as a determinant of rates of protein synthesis and degradation. These results indicated that effects of elevated aortic pressure on protein turnover were caused by stretch of the ventricular wall via its engorgement with blood, the so-called erectile properties of the heart or "garden-hose effect." These effects on protein turnover may be of importance in initiating hypertrophy of the heart secondary to pressure or volume overload.

Mechanical factors affecting protein turnover in isolated rat hearts

Induction of cardiac work increased protein synthesis in hearts supplied glucose or a mixture simulating normal plasma levels of glucose, insulin, glucagon, lactate, and beta-hydroxybutyrate. During 2 h of perfusion, cardiac work did not accelerate protein synthesis in hearts supplied a mixture of glucose, lactate, and higher concentrations of insulin. Protein degradation was decreased by work in hearts supplied glucose. Nitrogen balance was negative in Langendorff-perfused hearts provided glucose, but was less so in working preparations. Nitrogen balance was zero or positive in working hearts provided the mixture simulating plasma or the mixture of glucose, lactate, and insulin. In Langendorff preparations, increased aortic pressure accelerated protein synthesis during the second hour of perfusion in hearts supplied glucose, glucose plus insulin, or pyruvate. When ventricular pressure development was prevented by ventricular draining or when drained hearts were arrested with tetrodotoxin, protein synthesis still increased as perfusion pressure was raised from 60 to 120 mm Hg. Oxygen consumption increased as aortic pressure was increased in drained, beating hearts, but was unaffected in arrested, drained hearts. These studies indicated that increased aortic pressure and its attendant stretch of the ventricular wall were the mechanical parameter most closely associated with faster rates of protein synthesis.

Aortic pressure as a determinant of cardiac protein degradation

Mechanical parameters and intracellular mediators that may control protein degradation were studied in isolated rat hearts subjected to increased aortic pressure. Elevation of aortic pressure from 60 to 120 mmHg in Langendorff preparations provided glucose or pyruvate as substrate decreased the rate of protein degradation during the second hour of perfusion. Intracellular contents of ATP or creatine phosphate or the creatine phosphate/creatine ratio did not indicate that energy depletion accounted for these effects. When ventricular pressure development was prevented by ventricular draining, and hearts were arrested with tetrodotoxin, protein degradation still decreased as aortic pressure was raised. The effect of elevated aortic pressure on proteolysis was unchanged when perfusate calcium concentrations were 0.6, 3.0, or 5.1 mM, or when indomethacin or meclofenamate was added to the perfusion buffer. These results provided no evidence to indicate that intraventricular pressure development or cardiac contraction was responsible for the inhibitory effect of increased aortic pressure on protein degradation. Instead, they suggested that stretch of the ventricular wall, as a consequence of increased aortic pressure, could be the mechanical parameter most closely related to the restraint on proteolysis. No evidence was obtained that the lower rate of degradation depended on energy or calcium availability or prostaglandin synthesis.

Dependence of protein synthesis on aortic pressure and calcium availability

Increased aortic pressure accelerated protein synthesis in control-beating and arrested-drained hearts supplied with either glucose or pyruvate. Elevation of perfusion pressure from 60 to 120 mm Hg increased oxygen consumption in control-beating but not in arrested-drained preparations. Energy availability, as assessed by adenylate energy charge or creatine phosphate/creatine ratio, or both, was increased in arrested-drained hearts supplied with glucose and perfused at 60 and 120 mm Hg aortic pressure. In control-beating or arrested-drained hearts supplied with pyruvate, energy availability was not improved by elevation of aortic pressure from 60 to 120 mm Hg. An increase of perfusate calcium concentration from 0.5 to 5.0 mM in control-beating Langendorff preparations supplied with glucose and perfused at an aortic pressure of 90 mm Hg doubled oxygen consumption and decreased energy availability, but had no effect on the rate of protein synthesis. In arrested-drained hearts supplied with either glucose or pyruvate and calcium concentrations ranging from 0.5 to 5.0 mM, the rates at 120 mm Hg aortic pressure were 11-25% higher than at 60 mm Hg. These findings provide no evidence to implicate increased oxidative metabolism, energy availability, or extracellular calcium concentration as important factors in the mechanism that accounts for the effects of increased aortic pressure on protein synthesis.

Aortic pressure, substrate utilization and protein synthesis

An increase in aortic pressure from 60 to 120 mmHg in Langendorff perfused hearts increased oxygen consumption, glucose utilization, pyruvate oxidation and protein synthesis. These changes were not prevented by insertion of a ventricular drain that prevented intraventricular pressure development. Arrest of the heart with tetrodotoxin markedly reduced oxygen consumption; under these conditions an elevation of aortic pressure did not increase oxygen consumption. Elevation of aortic pressure in arrested-drained preparations supplied either glucose or pyruvate as oxidizable substrate increased protein synthesis to a comparable extent. Energy availability, as assessed by measurements of the creatine-P/creatine ratio, increased as aortic pressure was raised in hearts provided glucose, but not pyruvate, suggesting that greater energy availability was not the factor linking higher aortic pressure to faster rates of synthesis. These results focus attention on stretch of the ventricular wall, as the mechanical factor responsible for the effects of aortic pressure on several metabolic activities of the heart.

Factors determining the utilization of glucose in isolated rat hearts

Glucose utilization by the isolated rat heart is restricted by flux through the membrane transport, phosphofructokinase and glyceraldehyde-3-P dehydrogenase reactions. These reactions can be accelerated by hormones, such as insulin, by mechanical factors, such as the "garden-hose effect", heart rate, and perhaps ventricular pressure development, and by oxygen deprivation. Glucose utilization is restricted by provision of exogenous non-carbohydrate substrates and by utilization of endogenous substrate stores. Isolated hearts perfused as Langendorff preparations with or without a ventricular drain, working hearts, and ischemic preparations are useful in defining rate-limiting steps and mechanisms of regulation. However, when glucose is supplied as the sole exogenous substrate, its rates of utilization do not reflect the more complex in vivo situation where competing substrates such as fatty acids are preferentially utilized.

Effects of noncarbohydrate substrates on protein synthesis in hearts from fed and fasted rats

An overnight fast reduced RNA content and resulted in lower rates and efficiency of protein synthesis when rat hearts were perfused in vitro and supplied glucose as oxidizable substrate. Decreased efficiency of synthesis was associated with development of a block in peptide chain initiation in hearts of both fed and fasted rats. Provision of pyruvate increased the rate and efficiency of protein synthesis in fasted but not fed tissue, and partially overcame the initiation block in both groups. A mixture of glucose, pyruvate and insulin increased the efficiency of protein synthesis and decreased ribosomal subunit content to similar values in both groups of hearts. Noncarbohydrate substrates, including pyruvate, lactate, acetoacetate and beta-hydroxybutyrate, supported higher rates of protein synthesis than glucose in hearts of fasted, but not fed rats. However, mixtures of glucose and either pyruvate, acetoacetate or beta-hydroxybutyrate increased the synthetic rate in fed tissue. Provision of noncarbohydrate substrates increased energy availability, as indicated by higher creatine-P/creatine ratios in both groups of hearts, but the synthetic rate increased as a function of creatine-P/creatine ratio only in the fasted tissue. Octanoate and leucine accelerated protein synthesis and increased energy availability in the fed tissue. The mixtures of glucose and noncarbohydrate substrates or octanoate elevated glucose-6-P content. These studies indicate that an overnight fast decreased the capacity for protein synthesis and modified the regulation of synthesis by noncarbohydrate substrates.

Aortic perfusion pressure as a determinant of cardiac protein synthesis

Mechanical parameters and intracellular mediators that may control protein synthesis have been studied in isolated rat hearts subjected to increased aortic pressure or induced to perform cardiac work. Elevation of aortic pressure from 60 to 120 mmHg in Langendorff preparations with glucose, glucose plus insulin, or pyruvate raised the rate of protein synthesis during the 2nd h of perfusion. These effects involved faster rates of both peptide chain initiation and elongation. In working hearts supplied glucose or glucose plus insulin, higher rate of synthesis were observed in both the 1st and 2nd h of perfusion, compared with Langendorff preparations perfused at 60 mmHg. Intracellular levels of glucose 6-phosphate, ATP/ADP ratio, adenylate energy charge, or creatine phosphate/creatine did not correlate with the rate of protein synthesis in beating control hearts. When ventricular pressure development was prevented by ventricular draining and hearts were arrested with tetrodotoxin, protein synthesis still increased as a function of perfusion pressure. Oxygen consumption increased as aortic pressure was raised in beating-drained hearts but was unaffected in arrested-drained hearts. These results indicate that intraventricular pressure development, cardiac contraction, oxygen consumption, glucose 6-phosphate, energy availability, and coronary flow could be dissociated from the stimulatory effect of higher aortic pressures on protein synthesis and suggested that stretch of the ventricular wall, as a consequence of increased aortic pressure, could be the mechanical parameter most closely related to the increase in protein synthesis.

A study of auditory middle latency responses in relation to electrode combinations and stimulus conditions

Auditory middle latency responses were recorded from healthy right-handed subjects. Acoustic clicks at a rate of 10/s were presented to the subjects via headphones. Using the electrode combination unilateral mastoid-nose tip, responses characterized by two early negative waves (about 11.5 and 18 ms peak latencies), followed by a late positive one (about 30 ms peak latency), were elicited by binaural stimulation (50-dB SL clicks). The waveform of responses from the unilateral mastoid-nose tip combination was similar to that recorded from a combination of the same side mastoid and a balanced noncephalic reference electrode, although the phase was opposite to that recorded from the Cz-unilateral mastoid combination. Auditory middle latency responses were recorded simultaneously from right mastoid and left mastoid and referenced to the nose tip; interaural differences in amplitude were found in most subjects. The amplitudes of the early components for binaural stimulation were larger than those for monaural stimulation.