Differential Regional Responses in Soluble Monomeric Alpha Synuclein Abundance Following Traumatic Brain Injury

Alpha synuclein (α-synuclein) is a neuronal protein found predominately in presynaptic terminals. While the pathological effect of α-synuclein aggregates has been a topic of intense study in several neurodegenerative conditions, less attention has been placed on changes in monomeric α-synuclein and related physiological consequences on neuronal function. A growing body of evidence supports an important physiological role of α-synuclein in neurotransmission. In the context of traumatic brain injury (TBI), we hypothesized that the regional abundance of soluble monomeric α-synuclein is altered over a chronic time period post-injury. To this end, we evaluated α-synuclein in the cortex, hippocampus, and striatum of adult rats at 6 h, 1 day, 1, 2, 4, and 8 weeks after controlled cortical impact (CCI) injury. Western blot analysis demonstrated decreased levels of monomer α-synuclein protein in the ipsilateral hippocampus at 6 h, 1 day, 1, 2, and 8 weeks, as well as in the ipsilateral cortex at 1 and 2 weeks and in the ipsilateral striatum at 6 h after CCI compared with sham animals. Immunohistochemical analysis revealed lower α-synuclein and a modest reduction in synaptophysin staining in the ipsilateral hippocampus at 1 week after CCI compared with sham animals, with no evidence of intracellular or extracellular α-synuclein aggregates. Collectively, these findings demonstrate that monomeric α-synuclein protein abundance in the hippocampus is reduced over an extensive (acute-to-chronic) post-injury interval. This deficit may contribute to the chronically impaired neurotransmission known to occur after TBI.

Investigating accident causation through information network modelling

Management of risk in complex domains such as aviation relies heavily on post-event investigations, requiring complex approaches to fully understand the integration of multi-causal, multi-agent and multi-linear accident sequences. The Event Analysis of Systemic Teamwork methodology (EAST; Stanton et al. 2008) offers such an approach based on network models. In this paper, we apply EAST to a well-known aviation accident case study, highlighting communication between agents as a central theme and investigating the potential for finding agents who were key to the accident. Ultimately, this work aims to develop a new model based on distributed situation awareness (DSA) to demonstrate that the risk inherent in a complex system is dependent on the information flowing within it. By identifying key agents and information elements, we can propose proactive design strategies to optimize the flow of information and help work towards avoiding aviation accidents. Statement of Relevance: This paper introduces a novel application of an holistic methodology for understanding aviation accidents. Furthermore, it introduces an ongoing project developing a nonlinear and prospective method that centralises distributed situation awareness and communication as themes. The relevance of findings are discussed in the context of current ergonomic and aviation issues of design, training and human-system interaction.

Fenofibrate attenuates endothelial monocyte adhesion in chronic heart failure: an in vitro study

BACKGROUND

Inflammation is implicated in chronic heart failure (CHF). In this study, the potential inhibitory effect of peroxisome proliferator-activated receptor-alpha (PPARalpha) activator fenofibrate on monocyte adhesion in CHF patients was investigated in vitro.

MATERIALS AND METHODS

Isolated peripheral blood mononuclear cells (PBMCs) were collected from 36 patients (aged 65 +/- 8 years) with symptomatic CHF and from 12 healthy control subjects. The cultured human aortic endothelial cells (HAECs) were stimulated with or without 2 ng mL(-1) tumour necrosis factor-alpha (TNF-alpha) and the inhibitory effects of fenofibrate at 25, 50, 100 and 200 microM on endothelial mononuclear cell adhesion were tested. Furthermore, the HAECs were stimulated with 70% sera obtained from CHF patients and control individuals, respectively, with or without pretreatments with fenofibrate. The endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was then confirmed by mRNA expression and Western blot.

RESULTS

We found that the increased adhesion of PBMCs to TNF-alpha-stimulated HAECs in CHF patients was reduced when the HAECs were pretreated with fenofibrate (31% inhibition, P = 0.0121). However, pretreatment of the isolated PBMCs collected from CHF patients with fenofibrate failed to suppress their adherence to TNF-alpha-stimulated HAECs. Furthermore, stimulation of cultured HAECs with CHF patient sera significantly increased VCAM-1 and ICAM-1 expression, which could also be inhibited by fenofibrate.

CONCLUSIONS

The fenofibrate directly inhibits monocyte binding by TNF-alpha-activated HAECs, probably through preventing up-regulation of cell adhesion molecules by endothelial cells in response to inflammatory stimuli. This PPARalpha activator may have the potential to ameliorate vascular inflammation in patients with CHF.

Design and implementation of a system with a multielement thermopile for monitoring temperature of a plane

In this paper, we report the design of a system equipped with a multielement thermopile for measuring the temperature of a given plane. We evaluate the performance of our measurement system, which comprises a microcontroller, an analog-to-digital converter, a liquid crystal display (LCD), light-emitting diodes (LEDs), a buzzer, laser pointers, and a rotary encoder. We use different types of display modes such as an LCD for displaying the measured temperature, LEDs which colors indicate the temperature range, and an RS-232 or a wireless interface that transmits the temperature values to be displayed as different colors on a PC screen. The buzzer/alarm in the system is activated when the threshold temperature is reached. The system is inexpensive, portable, and can be used for two-dimensional temperature measurements; further, its emissivity can be easily adjusted. The effective detection range of this system is from -20 to 115 degrees C, and the field of view is 41 degrees x32 degrees ; the measurement error is confined to +/-1 degrees C. The experimental results demonstrate the effectiveness of the system in monitoring the temperature of a remote plane. Hence, it is possible to identify a hot spot that occurred in the electrical heating equipment or a smoldering source hidden in upholstery.

Using cognitive work analysis to explore activity allocation within military domains

Cognitive work analysis (CWA) is frequently advocated as an approach for the analysis of complex socio-technical systems. Much of the current CWA literature within the military domain pays particular attention to its initial phases; work domain analysis and contextual task analysis. Comparably, the analysis of the social and organisational constraints receives much less attention. Through the study of a helicopter mission planning system software tool, this paper describes an approach for investigating the constraints affecting the distribution of work. The paper uses this model to evaluate the potential benefits of the social and organisational analysis phase within a military context. The analysis shows that, through its focus on constraints, the approach provides a unique description of the factors influencing the social organisation within a complex domain. This approach appears to be compatible with existing approaches and serves as a validation of more established social analysis techniques. As part of the ergonomic design of mission planning systems, the social organisation and cooperation analysis phase of CWA provides a constraint-based description informing allocation of function between key actor groups. This approach is useful because it poses questions related to the transfer of information and optimum working practices.

Noninvasive respiratory monitoring system based on the piezoceramic transducer's pyroelectric effect

This paper presents a simple alternative method and system for noninvasive respiratory airflow monitoring. The proposed system uses a piezoceramic transducer to measure respiratory airflow. When a piezoceramic transducer is impacted by respiratory airflow, there is a piezoelectric and a pyroelectric response to pressure and thermal airflow fluctuations. In this study, the selected transducer's response output is dominated by the pyroelectricity factor. Therefore, the piezoelectric effect is not significant and can be ignored in this study. Using the transducer's pyroelectricity to measure thermal flow variations, a subject's respiratory rate and respiratory air volumetric flow rate can be monitored. The proposed system was evaluated for accuracy and response time using quiet and postphysical exertion breathing modes. Using the pneumotach system as a benchmark, the proposed system's respiratory rate measurement accuracy for the two breathing modes is approximately 98.78%. In addition, the proposed system's output voltage is highly correlated with the respiratory volumetric flow rate measured by the selected pneumotach (r2=0.9783). The average correlation coefficient between the pneumotach system's output waveform and the proposed system is approximately 0.9389. Moreover, the proposed system and the selected pneumotach have almost the same rapid response time to respiratory airflow. When compared to a temperature measurement thermistor system, the thermistor on average is approximately 25.3 ms slower than the proposed system. Furthermore, compared to the selected screen-type pneumotach system, the proposed system simplifies the respiration monitoring requirements. Instead of sensing the pressure drop across a mesh screen, like the screen-type pneumotach, it measures respiration at one point within the respiratory airflow. The proposed system benefits from simplified processing circuits and a mesh-free design. The advantages of this new respiratory airflow measurement method are fast response time, high accuracy, low cost, and ease of implementation.

An accurate air temperature measurement system based on an envelope pulsed ultrasonic time-of-flight technique

A new microcomputer based air temperature measurement system is presented. An accurate temperature measurement is derived from the measurement of sound velocity by using an ultrasonic time-of-flight (TOF) technique. The study proposes a novel algorithm that combines both amplitude modulation (AM) and phase modulation (PM) to get the TOF measurement. The proposed system uses the AM and PM envelope square waveform (APESW) to reduce the error caused by inertia delay. The APESW ultrasonic driving waveform causes an envelope zero and phase inversion phenomenon in the relative waveform of the receiver. To accurately achieve a TOF measurement, the phase inversion phenomenon was used to sufficiently identify the measurement pulse in the received waveform. Additionally, a counter clock technique was combined to compute the phase shifts of the last incomplete cycle for TOF. The presented system can obtain 0.1% TOF resolution for the period corresponding to the 40 kHz frequency ultrasonic wave. Consequently, with the integration of a humidity compensation algorithm, a highly accurate and high resolution temperature measurement can be achieved using the accurate TOF measurement. Experimental results indicate that the combined standard uncertainty of the temperature measurement is approximately 0.39 degrees C. The main advantages of this system are high resolution measurements, narrow bandwidth requirements, and ease of implementation.

What's skill got to do with it? Vehicle automation and driver mental workload

Previous research has found that vehicle automation systems can reduce driver mental workload, with implications for attentional resources that can be detrimental to performance. The present paper considers how the development of automaticity within the driving task may influence performance in underload situations. Driver skill and vehicle automation were manipulated in a driving simulator, with four levels of each variable. Mental workload was assessed using a secondary task measure and eye movements were recorded to infer attentional capacity. The effects of automation on driver mental workload were quite robust across skill levels, but the most intriguing findings were from the eye movement data. It was found that, with little exception, attentional capacity and mental workload were directly related at all levels of driver skill, consistent with earlier studies. The results are discussed with reference to applied theories of cognition and the design of automation.

Changing drivers' minds: the evaluation of an advanced driver coaching system

This paper reports on the study of an advanced driver coaching system. The study distinguishes between different types of post-licensure programmes in order to explore a system based on a model of identifying and responding to hazards, called 'information, position, speed, gear and acceleration' (IPSGA). Previous literature has been sceptical about the benefits of advanced driver education; thus, the current study was designed to control for the effects of coaching drivers in the 'IPSGA' system (the treatment group) against the effects of being accompanied (control group 1), as well as the mere effects of time (control group 2). Measures were taken before the driver coaching began (as a baseline measure) and again after 8 weeks (to see if any changes had occurred). These measures included driver knowledge via a post-drive interview, observations of driving skill and driver attitude using a locus of control scale. The results suggest that advanced driver coaching using the IPSGA system had a beneficial effect on all of these measures. Drivers in the coaching condition improved their situation awareness, driving skills and reduced attributions of external locus of control. The study lends support to the case for one-to-one individualized driver coaching using a systematic model of driving.

Envelope pulsed ultrasonic distance measurement system based upon amplitude modulation and phase modulation

A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the "measurement pulse" in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40 kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2 mm at a range of 50-500 mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation.

Quantification of pre-parturition restlessness in crated sows using ultrasonic measurement

This study presents the non-video, noninvasive, automatic, and on-site monitoring system employing ultrasonic transducers to detect the behavior in sows before, during and after parturition. An ultrasonic transmitting/receiving (T/R) circuit of 40kHz is mounted above a conventional parturition bed. The T/R units use ultrasonic time-of-flight (TOP) ranging technology to measure the height of the confined sows at 8 predetermined locations. It is suggested that the system could be applied to automatic prediction of sow parturition, with automatic notification of remote management personnel so human attendance at the birth could reduce rates of sow and piglet mortality.

Distributed situation awareness in dynamic systems: theoretical development and application of an ergonomics methodology

The purpose of this paper is to propose foundations for a theory of situation awareness based on the analysis of interactions between agents (i.e. both human and non-human) in subsystems. This approach may help to promote a better understanding of technology-mediated interaction in systems, as well as helping in the formulation of hypotheses and predictions concerning distributed situation awareness. It is proposed that agents within a system each hold their own situation awareness, which may be very different from (although compatible with) that of other agents. It is argued that we should not always hope for, or indeed want, sharing of this awareness, as different system agents have different purposes. This view marks situation awareness as a dynamic and collaborative process binding agents together on tasks on a moment-by-moment basis. Implications of this viewpoint for the development of a new theory of, and accompanying methodology for, distributed situation awareness are offered.

Differential effects of peroxisome proliferator-activated receptor ligands and sulfonylurea plus statin treatment on plasma concentrations of adipokines in type 2 diabetes with dyslipidemia

OBJECTIVES

Peroxisome proliferator-activated receptor gamma is the master regulator of adipocyte differentiation and controls many adipocyte genes in response to anti-diabetic thiazolidinediones (TZDs) and lipid-lowering fibrates. We hypothesized that the combination of TZD+fibrate may be better than the sulfonylurea + statin approach regarding modifying the adipokine profile in diabetic patients with dyslipidemia.

METHODS

We measured the lipid profiles and circulating levels of adiponectin, resistin, and inflammatory markers before and after treatment in 24 type 2 diabetic patients with dyslipidemia (aged 64+/-9 years; M/F=5/19). The study patients were randomly assigned to receive an 8-week treatment of either rosiglitazone 4 mg daily and fenofibrate 160 mg daily (PPAR group) or glibenclamide 5 mg daily and atorvastatin 10 mg daily (non-PPAR group).

RESULTS

Even though the administration of sulfonylurea+statin can achieve a greater reduction of total cholesterol and LDL-cholesterol levels and a comparable glucose control compared to PPAR treatment, their administration did not change the plasma adipokine levels significantly. In contrast, a significant greater increase of the plasma concentrations of adiponectin (P<0.0001), a trend to a greater decrease of the plasma resistin levels (P=0.061), a significantly greater increase of HDL-cholesterol (P=0.002), and a significantly greater reduction of triglyceride levels (P=0.018) were seen in the PPAR group.

CONCLUSIONS

Considering the clinical significance of the adipokine-endothelial interaction in the progression and long-term prognosis of atherosclerosis, the differential effects of PPAR ligands and sulfonylurea+statin on plasma adipokine concentrations demonstrated in this study are interesting foci of investigation in the future.

The effects of weight load and joint immobilization on reorganization of postural tremor

To investigate change in coordinative strategies due to wrist immobilization and index loading, postural tremors from the index, hand, and forearm were recorded during different postural holding tasks. The wrist joint was immobilized with a thermoplastic splint in the constrained condition, and a copper mass of 100 grams was applied to the index finger in the loaded condition. The structures of the postural tremors of all upper limb segments among the unloaded-unconstrained, unloaded-constrained, loaded-unconstrained, and loaded-constrained conditions were compared. Index loading exaggerated index/forearm postural tremor, while the load-induced tremor enhancement was no longer evident for wrist immobilization. In the unloaded condition, wrist immobilization resulted specifically in enhancement of carpal postural tremor, rather than in the index and forearm. Index loading induced a marked tremor peak and relative power in the range of 5-8 Hz. Wrist immobilization potentiated the carpal tremor peak of 1-4 Hz in association with enhancement of carpal-forearm mechanical coupling. In light of structural changes in postural tremor, our data suggest that (1) a wrist splint is effective to counteract load-induced enhancement of postural tremor, and (2) freezing of the wrist joint might facilitate compensatory strategies to minimize passive fluctuation transmission from the carpal to index.

Heart transplant coronary artery disease in Chinese recipients

BACKGROUND

Transplant coronary artery disease is the principle limiting factor for long-term survival of heart transplantation (HTx) recipients. We reviewed our data to assess the incidence of this disorder among Chinese HTx recipients and to compare it with the results of Western studies.

MATERIAL AND METHODS

From July 1988 to May 2002, 182 patients received 184 orthotopic HTx. One hundred sixty-three recipients survived for at least 1 year with available SPECT scans or coronary angiogram studies. The data set included donor characteristics, recipient characteristics, active cytomegalovirus (CMV) infection rate, rejection episodes, immunosuppressants, and human leukocyte antigen (HLA) mismatches.

RESULTS

Surgical mortality in our program was 4.3% and the actuarial freedom from coronary artery disease at 1, 3, and 5 years was 99%, 95%, and 92%, respectively. Angiogram results were stratified into coronary artery disease (n = 15) or absence of the disorder (n = 148) groups. Only older donor age showed statistical significance between the groups. Compared with the Western series, the present data show higher actuarial survival rates and freedom from coronary artery disease. There were statistically significant differences in regard to graft ischemia time, proportion of male recipients, ischemic heart disease, rejection episodes during the first year, and incidence of CMV infection.

CONCLUSIONS

SPECT scan can detect coronary artery disease before there is significant stenosis of the coronary artery with acceptable survival rates. Chinese HTx recipients show a lower incidence of the disorder, lower rates of ischemia heart disease, lower proportion of male gender, lower incidence of CMV infection, fewer rejection episodes during the first year, and less ischemic time than Western recipients, which maybe the contributing factors to their better survival.

Heart transplantation at Cheng Hsin General Hospital in Taiwan: 15-year experience

Heart transplantation (HTx) in Taiwan, which started in 1987, now includes more than 500 cases. From July 1988 to September 2003, we performed 215 cases of orthotopic HTx in 164 male and 51 female recipients of mean age of 47.3 +/- 14.3 years, (range 2.7 to 74.9 years). The leading etiologies were dilated cardiomyopathy (CMP), 68.5%; ischemic CMP, 20.2%; and valvular CMP, 4.2%. The actuarial survival rates at 1, 5, and 10 years are 88.3%, 77.1%, and 57.2%, respectively. We performed the first case of HTx in Asia after bridging for 14 days with an indigenous total artificial heart (TAH; the Phoenix-7 model); we performed the first case of infant HTx without blood transfusion and also the first case of autotransplantation of heart for repair of a left ventricular rupture after a mitral valve replacement. These cases were all successful with the longest surviving HTx recipient in Asia. We have used the biatrial anastomosis technique in all cases. We discovered familial CMP due to mitochondrial defects in two pediatric cases. Because of the scarcity of donor hearts, we have used size-mismatched hearts as well as suboptimal and hepatitis-positive donor hearts, all with satisfactory outcomes. Our experience has shown comparable results to Western programs, with efficacy and cost-effectiveness. We find the technique of biatrial anastomosis for orthotopic HTx to result in a low incidence of tricuspid regurgitation and conduction anomalies. The use of suboptimal and size-mismatched donor hearts is also promising.

Application of a mixed-mode solid-phase extraction and cleanup procedure for LC/MS determination of thiabendazole and carbendazim in apple juice

Recently, a mixed-mode solid-phase extraction (SPE) procedure was developed for rapid extraction and cleanup for determination of the fungicides thiabendazole and carbendazim in various fruit juices. This paper reports the application of that sample preparation procedure to the liquid chromatographic/mass spectrometric determination of these fungicides in apple juice with detection by positive electrospray ionization mass spectrometry (ESI/MS). Response was linear for sample concentrations from 2 to 500 microg/L (ppb). Recoveries averaged 74% (9% RSD) for carbendazim and 93% (9% RSD) for thiabendazole. After SPE cleanup, no matrix supression was observed for the ESI+ response for either compound studied. The method was applied to the analysis of incurred residues in 4 store-bought apple juices; carbendazim levels ranged from 10 to 70 microg/L and thiabendazole levels ranged from less than 2 to 130 microg/L.

Research Validity Scales for the NEO-PI-R: additional evidence for reliability and validity

We examined the reliability and validity of the research validity scales (Schinka, Kinder, & Kremer, 1997) for the NEO-Personality Inventory-Revised (NEO-PI-R) in a clinical sample. The Negative Presentation Management (NPM) and Positive Presentation Management (PPM) scales were found to have satisfactory internal consistency reliability. Support for the validity of these scales was provided by the pattern of convergent and discriminant correlations with respective Personality Assessment Inventory (PAI) validity scales. Finally, PAI profiles of individuals with invalid NPM scores were found to differ significantly from those with valid NPM scores. Comparisons of the invalid profiles with profiles from other clinical samples provided additional support for the use of the NPM scale as a measure of negative impression management.

STATT: a titrate-to-goal study of simvastatin in Asian patients with coronary heart disease. Simvastatin Treats Asians to Target

BACKGROUND

Most published studies on the use of lipid-lowering agents to treat hypercholesterolemia have focused on Western populations, with few data on Asian populations.

OBJECTIVE

The Simvastatin Treats Asians to Target (STATT) study used a titrate-to-goal protocol to evaluate the efficacy and tolerability of simvastatin 20 to 80 mg/d in the treatment of Asian patients with coronary heart disease.

METHODS

This was a multicenter, open-label, uncontrolled, 14-week study in patients with coronary heart disease and serum low-density lipoprotein cholesterol (LDL-C) levels of 115-180 mg/dL and triglyceride levels of < or = 400 mg/dL. The dose of simvastatin was titrated from 20 to 80 mg/d to achieve the National Cholesterol Education Program (NCEP) LDL-C target of < or = 100 mg/dL. The primary efficacy measure was the percentage of patients achieving the NCEP target. Among secondary measures were the percentage of patients achieving European Society of Cardiology/European Atherosclerosis Society/European Society of Hypertension target LDL-C levels of < or = 115 mg/dL and the percentage change from baseline in lipid parameters. Tolerability was assessed in terms of the overall incidence of adverse experiences and the incidences of the most commonly reported adverse experiences.

RESULTS

The intent-to-treat analysis included 133 Asian patients (93 men, 40 women; mean age, 59.5 years), of whom 125 completed 14 weeks of therapy. Their mean blood pressure was 130.2/79.4 mm Hg. Overall, 104 (78.2%) patients treated with simvastatin achieved LDL-C levels < or = 100 mg/dL at week 14, and 125 (94.0%) achieved this target at some point during the study. Similarly, 122 (91.7%) patients achieved an LDL-C level < or = 115 mg/dL at week 14, and 130 (97.7%) achieved this target at some point during the study. Treatment with simvastatin had favorable effects on the lipid profile, producing significant percentage changes from baseline in all parameters (P < 0.001). Simvastatin was well tolerated across the dose range. Overall, 40 patients (30.1%) had > or = 1 clinical adverse experience. Only 14 (10.5%) had adverse experiences that were possibly, probably, or definitely related to study drug; none of these experiences were considered serious. The most common adverse experiences (> or = 3% incidence) were abdominal pain (6%); chest pain (5%); dizziness (4%); and asthenia/fatigue, fibromyalgia, headache, insomnia, and upper respiratory tract infection (3% each). No new or unexpected adverse experiences were seen at the higher doses.

CONCLUSIONS

Simvastatin was effective and well tolerated at doses of 20, 40, and 80 mg/d in Asian patients with coronary heart disease. Titration enabled the majority to achieve target LDL-C levels of < or = 100 mg/dL.

Spontaneous reattachment of a dislodged atrial lead

Acute lead dislodgment is a complication that should be managed immediately. Spontaneous reattachment of a dislodged atrial pacing lead has never been reported before. This case report describes a lucky patient whose atrial lead spontaneously gained a new functioning position after dislodgment from its initial implantation site.

Mixed-mode solid-phase extraction and cleanup procedures for the liquid chromatographic determination of thiabendazole and carbendazim in fruit juices

Solid-phase extraction (SPE) procedures were developed for rapid cleanup and determination of thiabendazole and carbendazim in orange, apple, and grape juices. Samples were prepared by using an SPE cartridge containing a mixed-mode sorbent with both reversed-phase and strong cation-exchange chemistries. Analysis was by liquid chromatography with photodiode-array UV detection. Orange juice was analyzed by mixed-mode cation-exchange extraction with reversed-phase cleanup; the other juices were analyzed by reversed-phase extraction with cation-exchange cleanup. Recoveries >80% for carbendazim and >90% for thiabendazole. Quantitation limits were 20 microg/L for both analytes.

Phase II study of combination human recombinant GM-CSF with intermediate-dose cytarabine and mitoxantrone chemotherapy in patients with high-risk myelodysplastic syndromes (RAEB, RAEBT, and CMML): an Eastern Cooperative Oncology Group Study

A Phase II study of GM-CSF with intermediate-dose cytarabine and mitoxantrone was conducted in patients with high-risk myelodysplastic syndrome. It was designed to evaluate if priming with growth factor could increase the efficiency of chemotherapy. In this older population only two of 10 patients achieved a bone marrow CR, including one patient whose leukemic blasts had an "S" phase increase of 2.55x at 48 hr. Unexpected hepatotoxicity was noted. This regimen cannot be recommended for this elderly population of patients.

Associations between lipoprotein lipase gene polymorphisms and insulin resistance in coronary heart disease

BACKGROUND

Lipoprotein lipase (LPL) is a crucial enzyme in plasma lipoprotein metabolism. Variants of the LPL gene (Pvu II and Hind III polymorphisms) may increase the risk of developing coronary heart disease (CHD) but their effect on insulin resistance remains unknown. The present study was conducted to examine whether DNA variations of the LPL gene were related to insulin resistance, carbohydrate and lipid risk factors for CHD in nondiabetic individuals.

METHODS

Pvu II and Hind III allele status of the LPL gene and fasting plasma glucose, insulin and lipid values were determined in nondiabetic men with angiographically documented CHD (n = 102) and in a control group (n = 145). Plasma glucose and insulin responses to a 75-g oral glucose tolerance test and insulin resistance as measured by an insulin suppression test were also carried out in 46 (45%) of the patients with CHD and in 73 (50%) of the control individuals.

RESULTS

The allele frequencies of LPL Pvu II and Hind III were not significantly different between the CHD patients and the controls. No association was found between Pvu II status and blood pressure, fasting plasma glucose, insulin, lipid levels or insulin resistance in patients with CHD. Nevertheless, compared with individuals with the Hind III H2H2 allele, CHD patients carrying the H1 allele (H1H1 + H1H2) were more insulin resistant, as indicated by higher steady state plasma glucose concentrations (253 +/- 87 vs 200 +/- 74 mg/dl, p = 0.032).

CONCLUSIONS

We suggest that the LPL gene Hind III allele might be associated with insulin resistance in nondiabetic men with CHD. However, further studies with larger populations of both sexes will be required to confirm this finding.

Predictors of short-term outcome in Chinese patients with ambulatory heart failure for heart transplantation with ejection fraction <25%

Heart transplantation (HT) provides longer survival than that of the natural history in patients with dilated cardiomyopathy (DCM). However, the optimal timing for cardiac transplantation and predictors of mortality in patients with end-stage cardiomyopathy (ESCM) has been poorly defined. The primary purpose of this study focused on the natural history of ambulatory patients with ESCM for HT assessment. Secondly, we tried to determine prognostic factors of individuals with the poorest short-term outcome and the optimal timing for HT in patients with ESCM. Finally, clinical treatment with angiotensin converting-enzyme inhibitors (ACEIs), carvedilol and amiodarone in the prevention of mortality caused by ESCM, were retrospectively evaluated. The short-term outcomes of 119 referral patients with ESCM for four years were observed. The patients had New York Heart Association class III to IV dyspnea at initial assessment for HT. Left ventricular ejection fraction (LVEF) was 17 +/- 6% and cardiac index (CI) was 2.0 +/- 0.6l/min/m2. After optimization of medical treatment, the patients were divided into two major groups according to CI equal to or less than 2.0l/min/m2 and more than 2.0l/min/m2. HTs were accepted in 88 patients and the patients were divided into two groups: medical treatment (group 1, 56 patients) or HT (group 3, 32 patients); HT was not accepted in the other 31 patients (group 2). We studied the probability of the survival curve and prognostic variables of the groups with medical treatment in the follow-up of 12 +/- 9 months. During follow-up, 49 patients were alive without HT. The remaining 38 patients died; 27 patients were in group 1 and 11 patients were in group 2. Eight deaths in group 2 were sudden. The actuarial survival rate among the non-HT population was 73%, 68%, 63 %, and 56 % at 3, 6, 9 and 12 months, respectively. The actuarial survival rate among group 1 was 70 %, 59 %, 55 %, and 52 % at 3, 6, 9 and 12 months, respectively. The actuarial survival rate among group 2 was 87 %, 85 %, 77 %, and 65 % at 3, 6, 9 and 12 months, respectively. A comparison, excluding patients with HT, was performed with those who had survived < 1 year and > or 1 year after assessment, and those who had died. Two parameters were independent predictors of prognosis on univariate and multivariate analysis: total pulmonary vascular resistance (TPR) > or = 14 Wood units (W) and CI < 1.65 l/min/m2 at 6 and 12 months after assessment. Treatment with amiodarone for ventricular tachycardia (VT) showed no convincing role in the prevention of sudden death in our patients. Also, treatment with ACEIs or carvedilol for heart failure was unconvincing to improve the short-term outcome in this study. Our results suggest in properly selected patients that HT should be considered within six months among patients with severe heart failure. Hemodynamic parameters associated with right cardiac function are important determinants of mortality caused by progressive heart failure. Predictors such as CI and TPR may be considered as important markers of mortality in prediction of short-term outcome in patients with ESCM, as other predictors reported in the literature.

Coronary artery disease risk predicted by insulin resistance, plasma lipids, and hypertension in people without diabetes

BACKGROUND

It has been shown that insulin resistance syndrome, including glucose intolerance, dyslipidemia, and hypertension, is frequently associated with coronary artery disease (CAD). However, their relative contributions and predictive power in the development of CAD are still unclear, particularly in persons without diabetes.

METHOD

We examined these risk factors between 96 patients without diabetes but with angiographically documented CAD and 96 age-, sex-, and body mass index-matched healthy control subjects. Fasting plasma lipoprotein, glucose, and insulin concentrations in response to a 75-g oral glucose tolerance test were determined, and insulin sensitivity was measured by the insulin suppression test.

RESULTS

Patients with CAD had significantly higher values of fasting glucose, glucose and insulin responses to oral glucose tolerance test, total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride and decreased high-density lipoprotein (HDL) cholesterol concentrations compared with those of healthy people (P < 0.02-0.001). Although the steady-state plasma insulin values were similar in both groups, the steady-state plasma glucose (SSPG) concentrations were significantly higher in patients with CAD (12.2+/-0.4 versus 8.1+/-0.4 mmol/L, P < 0.001) compared with healthy subjects. When HDL < 0.9 mmol/L, LDL cholesterol > or = 4.1 mmol/L, triglyceride > or = 2.3 mmol/L, SSPG > or = 10.5 mmol/L, and presence of hypertension were defined as separate risk factors for CAD, significantly higher odds-ratio values were observed in patients with CAD compared with healthy people. From logistic multiple regression analysis, SSPG was the strongest risk, followed by lowered HDL cholesterol, elevated triglyceride and LDL cholesterol, and hypertension, to predict CAD. These 5 factors accounted for 36% of total risk for development of CAD in persons without diabetes.

CONCLUSIONS

Patients without diabetes with CAD have abnormal glucose metabolism, hyperinsulinemia, and insulin resistance. Degree of insulin resistance (SSPG values), plasma lipid values, and history of hypertension together accounted for one third of all risk for CAD, although degree of insulin resistance was the strongest risk factor.

The effects of selective response preparation on corticospinal excitability

OBJECTIVE

Both motor imagery and selective motor cues enhance performance. Motor cortex is activated during motor imagery. We wanted to learn if selective motor cueing also activates motor cortex.

METHODS

We gave normal right-handed subjects information about which hand to use to respond to an imperative stimulus (selective intention) or where in space an imperative stimulus would occur (selective attention). To minimize anticipatory responses, warning stimulus validity was 80%. During this choice reaction time task, we recorded magnetic motor evoked potentials. Imperative stimuli and transcranial magnetic stimulation were presented randomly to assess the effect of warning cues on reaction times and corticospinal excitability.

RESULTS

Selective intentional and attentional warning cues reduced reaction times, but neither stimulus altered motor evoked potentials.

CONCLUSIONS

These results suggest that unlike motor imagery, selective intention to respond to an imperative stimulus and shifting spatial attention to an imperative stimulus do not alter corticospinal excitability.

A combined system for measuring animal motion activities

In this study, we have developed a combined animal motion activity measurement system that combines an infrared light matrix subsystem with an ultrasonic phase shift subsystem for animal activity measurement. Accordingly, in conjunction with an IBM PC/AT compatible personal computer, the combined system has the advantages of both infrared and ultrasonic subsystems. That is, it can at once measure and directly analyze detailed changes in animal activity ranging from locomotion to tremor. The main advantages of this combined system are that it features real time data acquisition with the option of animated real time or recorded display/playback of the animal's motion. Additionally, under the multi-task operating condition of IBM PC, it can acquire and process behavior using both IR and ultrasound systems simultaneously. Traditional systems have had to make separate runs for gross and fine movement recording. This combined system can be profitably employed for normative behavioral activity studies and for neurological and pharmacological research.

Transcranial magnetic stimulation identifies upper motor neuron involvement in motor neuron disease

OBJECTIVE

To evaluate the sensitivity of transcranial magnetic stimulation (TMS) to identify upper motor neuron involvement in patients with motor neuron disease.

BACKGROUND

Diagnosis of ALS depends on upper and lower motor neuron involvement. Lower motor neuron involvement may be documented with electromyography, whereas definite evidence of upper motor neuron involvement may be elusive. A sensitive, noninvasive test of upper motor neuron function would be useful.

METHODS

TMS and clinical assessment in 121 patients with motor neuron disease.

RESULTS

TMS revealed evidence of upper motor neuron dysfunction in 84 of 121 (69%) patients, including 30 of 40 (75%) patients with only probable upper motor neuron signs and unsuspected upper motor neuron involvement in 6 of 22 (27%) patients who had purely lower motor neuron syndromes clinically. In selected cases, upper motor neuron involvement identified with TMS was verified in postmortem examination. Increased motor evoked potential threshold was the abnormality observed most frequently and was only weakly related to peripheral compound muscle action potential amplitude. In a subset of 12 patients reexamined after 11+/-6 months, TMS showed progression of abnormalities, including progressive inexcitability of central motor pathways and loss of the normal inhibitory cortical stimulation silent period.

CONCLUSIONS

TMS provides a sensitive means for the assessment and monitoring of excitatory and inhibitory upper motor neuron function in motor neuron disease.

Effect of stimulator orientation on F-wave persistence

Most electrodiagnosis texts advocate cathode distal stimulation (CDS) for nerve conduction, but suggest cathode proximal stimulation (CPS) for F waves, because of anodal block. We postulated that CDS and CPS elicit F waves of similar persistence. We studied 657 (207 median, 204 ulnar, 136 tibial, and 110 peroneal) nerves in 225 consecutive subjects. In the median nerve, CDS elicited F waves of slightly greater persistence than CPS. Stimulator orientation did not affect F-wave persistence in the remaining nerves.

Angiotensinogen gene polymorphism is associated with insulin resistance in nondiabetic men with or without coronary heart disease

BACKGROUND

Variants of the angiotensinogen gene may increase the risk of having arterial hypertension and coronary heart disease (CHD), but their effect on insulin resistance remains unknown.

METHODS

We determined M235 and T174 allele status and fasting plasma glucose, insulin, and lipids values in nondiabetic men with CHD documented on angiography (n = 102) and in a control group (n = 145). Plasma glucose and insulin responses to 75 gm oral glucose tolerant test and insulin resistance as measured by an insulin suppression test were also carried out in 46 (45%) patients with CHD and in 73 (50%) members of a control group.

RESULTS

We found no association between M235T status and blood pressure, fasting plasma glucose, insulin, most of the lipids values, and insulin resistance in patients with CHD and normal subjects. Nevertheless, compared with individuals with homozygotes T174, subjects with heterozygotes T174M were associated with greater glucose and insulin response to the oral glucose tolerance test and insulin resistance indicated by higher steady state plasma glucose concentrations in patients with CHD (14.7+/-0.9 vs 11.3+/-0.7 mmol/L, p < 0.04). Similar findings were found in the control group, with higher steady-state plasma glucose values in individuals with heterozygotes T174M than in those with homozygotes T174 (10.1+/-1.4 vs 7.7+/-0.4 mmol/L, p < 0.05).

CONCLUSION

We suggest that the angiotensinogen T174M allele might be associated with insulin resistance in nondiabetic men with and without CHD.

Preparation of environmental samples for determination of sulfonylurea herbicides by solid-phase extraction using a polymeric sorbent

An analytical procedure was developed for rapid determination of sulfonylurea herbicides in water or soil. Samples were prepared by solid-phase extraction using polymeric sorbents in cartridges and analyzed by liquid chromatography with photodiode array detection. Recoveries were consistent for all sample matrixes tested and were generally > 85%, except for tribenuron methyl (75%). Detection limits were < 100 ng/L for water samples.

Effectiveness of an organized follow-up system for elder patients released from the emergency department

OBJECTIVES

To determine whether an effective telephone callback system can be successfully implemented in a busy ED and to quantify the benefits that can be obtained related to the follow-up care of elder patients.

METHODS

This was a prospective, cohort study conducted at a community teaching hospital during a 6-month period. Consecutive patients > or = 60 years old and released from the ED were selected for telephone follow-up. Calls were made by a research nurse within 72 hours after the patient's ED visit. Follow-up information included current medical status, problems encountered during the ED visit, compliance, and impact of the illness on self-care capabilities.

RESULTS

Seventy-nine percent (831/1,048) of the patients selected for telephone follow-up were successfully contacted. The calls lasted an average of 4 +/- 2.5 minutes. Although 94% (778/831) of these patients had a regular physician, 14% failed to make their recommended follow-up arrangements. Compliance was significantly improved when a follow-up physician was contacted during the patient's ED visit. Approximately 96% of the patients were either satisfied or very satisfied with their ED care. However, 13% (109/831) had moderate deterioration in their ability to care for themselves. Of the patients contacted, 333 (40%) required further clarification of their home care instructions, 31 were advised to return to the ED for reevaluation, and 26 were referred to a medical social worker for psychosocial concerns.

CONCLUSION

A telephone callback system is a feasible and effective method to improve follow-up care of elder patients released from the ED.

Stereotactic pallidotomy lengthens the transcranial magnetic cortical stimulation silent period in Parkinson's disease

We compared the duration of the EMG cortical stimulation silent period (CSSP) elicited in abductor pollicis brevis using transcranial magnetic stimulation (TMS) before and after stereotactic unilateral globus pallidus internus pallidotomy (PAL) in 12 patients with Parkinson's disease. We used TMS stimulus intensities of 200, 150, 120, and 100% of motor evoked potential (MEP) threshold before and after (86 +/- 25 days) PAL. PAL increased CSSP duration at stimulus intensities of 200% of MEP threshold in the hand contralateral to the stereotactic lesion. In a subset of five patients able to remain at rest during pre-PAL testing sessions, PAL decreased the resting MEP/M-wave area ratio in the hand contralateral to the lesion at a stimulus intensity of 120% of MEP threshold. PAL did not significantly modify the effects of TMS in the hand ipsilateral to the globus pallidus lesion. The results suggest that PAL improves the function of cortical motor inhibitory circuits in Parkinson's disease.

Ultrasonic analysis of tremorine and cold tremor activity in unanesthetized rats

In order to quantify the tremorine and cold tremor activity in unanesthetized rats, a new ultrasonic motion transducer method was used. Both kinds of activity are reported as vibratory body motion that occurred between 18-32 Hz as determined by spectral analysis. The recorded signal was analyzed and its power spectrum was obtained through a fast Fourier transform operation. It was found that a negative linear relation occurs between shiver amplitude and ambient temperature (r = 0.999). A negative linear relation also occurs between metabolic rate and ambient temperature (r = 0.997). In addition, a positive linear relation between metabolic rate and cold shiver exists (r = 0.999). Both tremorine (30 mg/kg, i.p.) and cold tremor (Ta = 2-22 degrees C) activity monitored by the ultrasonic method were completely abolished by premedication with 1 mg/kg atropine. Thus, it appears that the advantages of this tremor detection method are that is non-invasive and non-contact. Therefore, the ultrasonic method provides a good choice for quantifying tremorine and cold tremor activity in unanesthetized animals during studies of thermoregulatory physiology or motor disorders.

A new ultrasonic method for measuring minute motion activities of rats

A new ultrasonic method is presented for measuring the minute motion activities of rats. A pair of low-cost 40 kHz ultrasonic transducers are used to transmit ultrasound toward a rat and receive the ultrasound reflected from the rat. The relative motion of the rat modulates the phase difference between the transmitted and received ultrasound signals. An 8-bit digital phase meter was designed to record the phase difference signal which was used to reconstruct the relative motion waveform of the rat in an 8751 single-chip microcomputer. The reconstructed data are then sent to a PC-AT microcomputer for further processing. This method employs a spectrum analysis for the reconstructed data and can measure three minute motion activities including locomotor activity (LMA), tremor and myoclonia. Finally, the method has been tested with real animal experiments. The main advantages of this new method are that it is non-invasive, non-contact, low cost and high precision. This new method could also be profitably employed for other behavioral studies and offer potential for research in basic medicine.

A new automated method for detection and recording of animal moving path

A new electronic system has been developed to trace the location and movement of small animals in an open-field environment. The system, incorporated with a conventional touch panel position sensor (TPPS) and an IBM AT compatible computer, automtically digitizes and records the moving path of the animal. The detection principle of the TPPS is based on the pressure effect. Whenever an animal is put on the TPPS, the location of the animal can be detected. The personal computer system is in corporate to record the locomotion data of the animal. The system described here is shown to be a reliable and accurate tool to record the moving path of an animal. This measurement did not require extra light or other stimuli, and the apparatus is low priced, and simple to build up and user friendly.

Facilitation of magnetic motor evoked potentials during the mixed nerve silent period

We studied motor neuron excitability during the mixed nerve silent period (MNSP) in a hand muscle using magnetic motor evoked potentials (MEPs) and F-waves. MEPs elicited between the V1 and V2 potentials of the MNSP were much larger than control MEPs elicited at rest, and were even comparable in size to control MEPs elicited during voluntary contraction. This facilitation of MEPs occurred without shortening of MEP latency, suggesting a supraspinal mechanism. MEPs were facilitated during the MNSP when elicited with a figure-8-shaped coil in a posterior-anterior orientation, but not when MEPs of the same size were elicited with the coil held in a lateral-medial orientation. F-waves elicited during the MNSP were variable between subjects, and not consistently different from control F-waves elicited at rest. Our findings may reflect increased cortical motor excitability during the MNSP, possibly related to activation of muscle afferents by mixed nerve stimulation.

Primary malignant cardiac tumor: an analysis of seven cases

BACKGROUND

Primary malignant cardiac tumor is a rare disorder which has a myriad of clinical manifestations. It dominates about one-fourth of all cardiac tumors, exhibiting typically malignant histological characteristics and invasive behavior.

METHODS

Seven cases of primary malignant cardiac tumor were collected over eight years (1985-1993) in this hospital. Each case had different manifestations. All cases were diagnosed by physical examination, echocardiogram and were subsequently proved by tissue pathology.

RESULTS

The majority of these seven cases of primary malignant cardiac tumor had clinical symptoms of chest distress, shortness of breath and paroxysmal nocturnal dyspnea. The relatively young ages of the patients ranged from 11 to 62 years. One case of angiosarcoma, one case of fibrosarcoma, one case of leiomyosarcoma and three cases of lymphoma had the characteristics of cardiac hemodynamic obstruction which was induced by location and size of the tumors in the heart. Five cases of those primary malignant cardiac tumor were mortal; the average life span was nine months following surgical resection and chemotherapy.

CONCLUSIONS

From a clinical viewpoint, primary malignant cardiac tumor characteristically displays a rapid downhill course. Death most often occurs from a few weeks to two years after the onset of symptoms. Because these tumors are rare and have a poor clinical outcome, early diagnosis and treatment are vital.

A high-precision ultrasonic system for vertical movement counts in rats

A microcomputer-aided ultrasonic system was used to measure vertical displacement of rats in response to drug injection. The system utilizes an inexpensive PC/AT microcomputer for data collection and can distinguish between number of vertical movements of small (i.e., greater than 5 mm, but less than 15 mm), and large (i.e., greater than 15 mm) displacements. In addition, rest time denotes the time elapsed for the vertical motion of less than 5-mm displacements. As little as 0.32 mg/kg of d-amphetamine increased the average amount of both small and large activity (i.e., number of movements), but decreased the average amount of rest time in rats. On the contrary, as little as 2.5 mg/kg of chlorpromazine decreased the average amount of both small and large activity, but increased the rest time in rats. When the animal activity was measured with an infrared light system, the activity responses to drugs were not detectable. Thus, it appears that the ultrasonic method provides a high-precision system for measuring animal behaviors.

Electromyographic biofeedback use in the treatment of voluntary posterior dislocation of the shoulder: a case study

Voluntary posterior dislocation of the shoulder has been difficult to treat successfully. Electromyographic biofeedback is a nonoperative treatment measure that has been successfully used for this condition in three previously reported cases. The purpose of this article is to present a case history in which electromyographic biofeedback was used successfully as part of a nonoperative treatment program for voluntary posterior dislocation of the shoulder.

Heart failure due to chronic experimental aortic regurgitation

Previously reported experimental models of aortic regurgitation generally have manifested normal systolic performance and have not developed heart failure [Magid et al. Am. J. Physiol. 263 (Heart Circ. Physiol. 32): H226-H233, 1992]. To determine whether more severe chronic experimental aortic regurgitation would generate systolic malperformance, heart failure, and emulate the human disease process, 11 New Zealand White rabbits underwent surgical induction of aortic regurgitation and 5 control animals underwent sham operation. Doppler echocardiography was performed serially for up to 3 yr, and pathological studies were performed at necropsy. Left ventricular internal dimension at end diastole increased 80% (P < 0.00002) and left ventricular weight increased 250% (P < 0.0002) in aortic regurgitant rabbits (regurgitant fraction 52 +/- 13%) compared with baseline values. Six of 11 aortic regurgitant animals died with pathological evidence of congestive heart failure at 1.5 +/- 0.8 yr postoperatively; 2 of these developed severe systolic malperformance, manifest as fractional shortenings of 15 and 19% at 1.6 and 1.7 yr, respectively. Five of 11 aortic regurgitant animals survived until killed at 2.9 +/- 0.1 yr. Thus moderate-to-severe chronic aortic regurgitation in rabbits frequently results in heart failure and systolic dysfunction and may usefully model chronic aortic regurgitation and heart failure in humans.

A simplified method for selecting a carbon-fiber electrode in pulse voltammetry

A method for selecting a usable carbon-fiber electrode using the equivalent resistance and capacitance is presented. This method uses an instrument with a PC-based look-up table for measuring the electrical characteristics of a carbon-fiber electrode in pulse voltammetry. Using this instrument, the equivalent resistance and capacitance of the carbon-fiber electrode in saturated sodium chloride solution can be obtained. This instrument includes a decade resistance box, a peak current detection and hold circuit, a half peak comparator and a decay duration counter. A look-up table is established by using RC circuits to emulate the electrochemical reaction of the carbon-fiber electrode in pulse voltammetry. The equivalent resistance is obtained from the decade resistance box according to Kirchhoff's law. Then the equivalent capacitance is determined from the decay duration counter reading and equivalent resistance with the look-up table via a PC interpolation program. After obtaining the equivalent resistance and capacitance of an electrode, the values are compared with the usable thresholds. This method provides an effective quality evaluation index of carbon-fiber electrode for the user in order to reduce electrode-induced experimental failure. The method is also available for other kinds of carbon-fiber electrodes as long as their look-up table and desired thresholds are established.

Antagonistic effects of stimulation of the paramedian reticular nucleus in the rat medulla oblongata and of amphetamine on locomotor activity and striatal release of dopamine-like material

The effects of stimulation of the paramedian reticular nucleus (PRN) in the rat medulla oblongata on both amphetamine-induced locomotor activity and striatal release of dopamine-like material were assessed. PRN stimulation (by intra-PRN injection of the excitatory amino acid, kainic acid) decreased vertical motion and total distance travelled, and increased postural freezing, in freely moving rats. On the other hand, a small dose (e.g. 1.25 mg/kg, i.p.) of amphetamine increased locomotor activity (including horizontal motion, vertical motion, total distance travelled and lines crossed counts), increased the number of turnings (both clockwise and anti-clockwise), induced locomotor stereotypy (including both gamma value and number of trip types), and inhibited postural freezing. The changes in activity induced by amphetamine administration were suppressed following PRN stimulation. In vivo voltammetric data revealed that electrical stimulation of the PRN decreased the release of dopamine-like material in the corpus striatum. This effect could be mimicked by intra-PRN injection of kainic acid in anesthetized rats. In contrast, i.p. administration of amphetamine increased the release of dopamine-like material in the corpus striatum. Furthermore, the enhanced release of dopamine-like material induced by amphetamine was attenuated by simultaneous stimulation of the PRN. The results reported here indicate that PRN stimulation decreases the striatal dopamine release and results in attenuation of the amphetamine-induced locomotor activity responses in rats.