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.

The Impact of Fractional Flow Reserve-Guided Coronary Revascularization in Patients with Coronary Stenoses of Intermediate Severity

BACKGROUND

Previous studies have shown that the use of fractional flow reserve (FFR) in addition to angiography significantly reduced the rate of all major adverse cardiovascular events (MACE). However, this practice has not been widely accepted and limited outcome data exist about FFR-guided percutaneous coronary intervention (PCI) in Taiwan. The aim of the present study was to evaluate the possible impact of FFR-guided PCI in coronary stenoses of intermediate severity.

METHODS

We performed a retrospective case-control study on 443 cases of intermediate coronary stenoses in 206 patients recruited from our computerized database. The study patients were divided into two groups: the FFR group (n = 101) and the angiography group (n = 105), matched with age, gender, clinical and angiographic lesion characteristics. In the angiography group, the indicated lesions had been treated with PCI by angiographic or anatomical assessment, whereas those patients in the FFR group underwent PCI of indicated lesions only if the FFR was < 0.80. The primary end point was the MACE rate regarding death, nonfatal myocardial infarction (MI), and target vessel failure at a mean follow-up of 418 days.

RESULTS

The MACE rate was similar in both groups (6% in the angiography group and 3% in the FFR group, p = 0.06). However, FFR-guided PCI strategy prevented unnecessary revascularization in up to 75% of patients, and markedly reduced costs of the index hospitalization. Moreover, multivariate analysis found that the use of drug-eluting stent and statin therapy, and the presence of family history of premature coronary artery disease and periprocedural MI are independent predictors of clinical outcomes.

CONCLUSIONS

FFR-guided intervention, compared to angiography-guided intervention for Taiwanese patients with coronary stenoses of intermediate severity, achieved similar clinical outcomes and provided cost-savings.

In-Hospital Tele-ECG Triage and Interventional Cardiologist Activation of the Infarct Team for STEMI Patients is Associated with Improved Late Clinical Outcomes

BACKGROUND

Due to recent advances, door-to-balloon time (D2BT) has been reduced significantly for patients with ST-segment elevation myocardial infarction (STEMI). However, whether this reduction can be translated into a concrete mortality or morbidity benefit is still the subject of controversy. We conducted a before-and-after study to determine the impact of in-hospital tele-electrocardiography (ECG) triage and interventional cardiologist activation of the infarct team on D2BT and long-term clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI).

METHODS

A total of 272 consecutive patients with acute STEMI undergoing PPCI were enrolled in our study, comprising 102 tele-ECG patients and 170 conventional triage patients. Major adverse cardiovascular and cerebral vascular events (MACCE), including death, recurrent nonfatal MI, nonfatal stroke, and angina-driven target vessel revascularization were recorded during a 3-year follow-up.

RESULTS

The median D2BT of the tele-ECG group was significantly shorter than control group (79 minutes vs. 109 minutes, p < 0.001). The tele-ECG triage group had a higher percentage of patients reaching the D2BT goal (< 90 minutes) (78% vs. 55%; p < 0.001). The MACCE rate was significantly lower in the Tele-ECG versus the control group (23.5% vs. 38.2%, p = 0.012). Tele-ECG group had a lower mortality rate which did not reached statistical significance (2% vs. 5.9%, p = 0.102). In multivariable Cox proportional hazards analyses, the implementation of tele-ECG triage (HR = 0.43, p = 0.003) and the presence of moderate or severe mitral regurgitation at presentation (HR = 1.87, p = 0.029) were discovered as independently associated with MACCE.

CONCLUSIONS

In-hospital tele-ECG triage and interventional cardiologist activation can shorten D2BT and is associated with improved late clinical outcomes during a 3-year follow-up in STEMI patients undergoing PPCI.

Transradial versus transfemoral rotablation for heavily calcified coronary lesions in contemporary drug-eluting stent era

BACKGROUND

Although radial access for drug-eluting stent (DES) combined with rotational atherectomy (RA) in patients with calcified coronary lesions may be associated with a lower risk of major bleeding complications and obtain favorable clinical results compared with femoral access, the long-term outcome data of this approach were limited in contemporary DES era.

METHODS & RESULTS

This retrospective study sought to compare in-hospital and long-term outcomes for patients undergoing RA via the transradial (TR) and transfemoral (TF) route in 126 consecutive patients (59 radial, 67 femoral) from 2009 to 2014. TR RA procedures were performed in 44/62 (71%) by the three TR operators, compared with 15/64 (23%) by the four TF operators in the present study. Significantly smaller diameter guide catheters and burrs (1.39 ± 0.16 mm vs. 1.53 ± 0.24 mm, P = 0.001) were used in the TR group. Procedural success rates were similar in both TR and TF groups. There was a significantly less major access site bleeding complications in favor of radial artery access (2% vs. 16%, P = 0.012). The incidence of in-hospital death or myocardial infarction was low in both groups. Although a trend of lower adverse event rate was demonstrated in the TR group compared with the TF one, no statistical significance (21% vs. 27%, P = 0.135) was detected.

CONCLUSIONS

Radial access, a useful alternative to femoral access for RA and DES, can be safely and successfully performed on up to 71% of the patients with heavily calcified coronary lesions needing RA by experienced TR operators.

The effects and underlying mechanisms of S-allyl l-cysteine treatment of the retina after ischemia/reperfusion

PURPOSE

Retinal ischemia-associated ocular disorders are vision-threatening. The aim of the present study was to examine whether S-allyl l-cysteine (SAC) is able to protect against retina ischemia/reperfusion injury.

METHODS

In vivo, retinal ischemia in the rat was induced by raising intraocular pressure (IOP) to 120 mmHg for 60 min. In vitro, an ischemic-like insult, namely oxidative stress, was established by incubating retinal ganglion cell-5 (RGC-5) with 500 μM H(2)O(2) for 24 h. The mechanisms involved in these processes were evaluated by electrophysiology, immunohistochemistry, and molecular biological approaches.

RESULTS

The retinal changes caused by the high IOP were characterized by a decrease in electroretinogram b-wave amplitudes, a loss of choline acetyltransferase immunolabeling amacrine cell bodies/neuronal processes, and an upregulation of the mRNA levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelium growth factor (VEGF), and matrix metalloproteinase-9 (MMP-9). The increased protein levels of HIF-1α, VEGF, and MMP-9 were also seen in RGC-5 cells subjected to defined oxidative stress. Of clinical importance, the ischemic/ischemic-like detrimental effects were concentration-dependently (least effect at 25 μM) and/or significantly (50 and/or 100 μM) blunted when SAC was applied 15 min before retinal ischemia or ischemic-like insult, respectively.

CONCLUSION

SAC would seem to protect against retinal ischemia by acting as an antioxidant and inhibiting the upregulation of HIF-1α, VEGF, and MMP-9.

Effect of emergency department in-hospital tele-electrocardiographic triage and interventional cardiologist activation of the infarct team on door-to-balloon times in ST-segment-elevation acute myocardial infarction

Current guidelines recommend that >75% of patients with ST-elevation myocardial infarction (STEMI) receive primary percutaneous coronary intervention (PPCI) within 90 minutes. The goal has been hardly achievable, so we conducted a 2-year before-and-after study to determine the impact of emergency department (ED) tele-electrocardiographic (tele-ECG) triage and interventional cardiologist activation of the infarct team at door-to-balloon time (D2BT) and the proportion of patients undergoing PPCI within 90 minutes since arrival. In total 105 consecutive patients with acute STEMI (mean age 62 ± 13 years, 82% men) were studied, 54 before and 51 after the change in protocol. The 51patients in the tele-ECG group underwent tele-electrocardiography at the ED and electrocardiograms were transmitted to a third-generation mobile telephone of an on-call interventional cardiologist within 10 minutes of ED arrival. The infarct team was activated and PPCI was performed by the interventional cardiologist. Fifty-four patients with acute STEMI who underwent PPCI in the year before implementation of tele-electrocardiography served as control subjects. Median D2BT of the tele-ECG group was 86 minutes, significantly shorter than the median time of 125 minutes of the control group (p <0.0001). The proportion of patients who achieved a D2BT <90 minutes increased from 44% in the control group to 76% in the tele-ECG group (p = 0.0001). In conclusion, implementation of ED tele-ECG triage and interventional cardiologist activation of the infarct team can significantly shorten D2BT and result in a larger proportion of patients achieving guideline recommendations.

Transradial approach in myocardial infarction

OBJECTIVE

This study investigates the feasibility, efficacy, and safety of routine primary percutaneous coronary intervention via transradial approach in patients with acute ST-elevation myocardial infarction.

METHODS AND RESULTS

From 2005 to 2007,122 consecutive patients with acute ST-elevation myocardial infarction within 12 hours, including those experiencing cardiogenic shock, were eligible for primary transradial PCI if the radial artery pulse could be felt. Efficacy, safety, and major adverse cardiac events regarding mortality, recurrent non-fatal myocardial infarction, and revascularization were recorded. Eighty-five of 122 patients underwent transradial PCI, and 37 had transfemoral PCI. Older women, haemodynamic instability, and the presence of severe chronic kidney disease (stages 4 and 5) or end-stage renal disease were significantly related to choice of transfemoral approach (P < 0.05). Glycoprotein IIb/IIIa inhibitors were used more often in patients who underwent transradial PCI than in those who underwent transfemoral PCI (37% vs 16%; P = 0.043). The incidence of major bleeding complications requiring blood transfusion was significantly higher in the transfemoral group (P = 0.004). A similar procedural success rate was achieved in both groups (P = 0.737). During follow-up of 580 days, the total major adverse cardiac events were similar in both groups (P = 0.299).

CONCLUSIONS

Routine transradial primary PCI can be safely and successfully performed on up to 70% of acute ST-elevation myocardial infarction patients and, compared with transfemoral approach, is associated with a significantly reduced rate of major bleeding complications.

Baicalein significantly protects human retinal pigment epithelium cells against H₂O₂-induced oxidative stress by scavenging reactive oxygen species and downregulating the expression of matrix metalloproteinase-9 and vascular endothelial growth factor

PURPOSE

Age-related macular degeneration is a leading cause of blindness in the elderly. At a later stage, neovascular or exudative age-related macular degeneration can lead to severe central vision loss that is related to aging-associated cumulative oxidative stress of the human retinal pigment epithelium (hRPE) cells. Early prevention with antioxidants is mandatory. The aim of this study was to determine whether and how baicalein can act as an antioxidant.

METHODS

The methods used included lactate dehydrogenase, 2′,7′-dichloro-fluorescein diacetate, or enzyme-linked immunosorbent assay to measure cell viability, oxygen free radical levels, or the levels of vascular endothelial growth factor (VEGF)/matrix metalloproteinase-9 (MMP-9), respectively.

RESULTS

H₂O₂ dose-dependently reduced the cell viability of hRPE cells. This negative effect was dose-dependently (with a lower effect at 20µM) and significantly counteracted by pretreatment with baicalein (50µM). Treatment with H₂O₂ significantly stimulated the formation of oxygen free radicals. This increase was dose-dependently and significantly blunted by baicalein. Further, treatment with a sublethal dose of H₂O₂ was associated with an upregulation in the levels of VEGF and MMP-9. The increases in these proteins were also dose-dependently (with a lower effect at 20µM) and significantly (50µM) blunted by pretreatment with baicalein.

CONCLUSION

This study supports an antioxidative role for baicalein whereby it protects hRPE cells against H₂O₂-induced oxidative stress by downregulating the levels of VEGF and MMP-9, which are increased by H₂O₂.

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.

Increased endothelial monocyte adhesiveness is related to clinical outcomes in chronic heart failure

BACKGROUND

Vascular inflammation and endothelial dysfunction are evident in patients with chronic heart failure (CHF). We hypothesized that circulating peripheral blood mononuclear cells (PBMCs) may be activated and the resultant increased endothelial monocyte adhesion may be functionally and pathophysiologically relevant in CHF. In the present study, we investigated the clinical significance of the activity of PBMCs in patients with CHF.

METHODS

PBMCs were isolated from 34 CHF patients, from 10 healthy volunteers (normal control group) and from 17 patients admitted for investigation of suspected coronary artery disease (disease control group). In each patient, the adhesiveness of PBMCs to cultured human aortic endothelial cells (HAECs) with or without tumor necrosis factor-alpha (TNF-alpha) stimulation was determined. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening heart failure) were determined in the 34 CHF patients during a median follow-up period of 182 days.

RESULTS

Compared with those from both control groups and from mild CHF patients, PBMCs isolated from severe CHF patients adhered more to the HAECs. The endothelial adhesiveness of PBMCs correlated positively with the circulating levels of CAMs and can supply prognostic information in CHF patients. The difference between event-free curves based on the median levels of endothelial-PBMC adhesion was significant (log rank test, p=0.0139).

CONCLUSIONS

Endothelial adhesiveness of PBMCs is increased and correlated to clinical outcomes, and may be pathophysiologically relevant to the progression of CHF.

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.

Live/real time three-dimensional transthoracic echocardiographic assessment of left ventricular volumes, ejection fraction, and mass compared with magnetic resonance imaging

Due to reliance upon geometric assumptions and foreshortening issues, the traditionally utilized transthoracic two-dimensional echocardiography (2DTTE) has shown limitations in assessing left ventricular (LV) volume, mass, and function. Cardiac magnetic resonance imaging (MRI) has shown potential in accurately defining these LV characteristics. Recently, the emergence of live/real time three-dimensional (3D) TTE has demonstrated incremental value over 2DTTE and comparable value with MRI in assessing LV parameters. Here we report 58 consecutive patients with diverse cardiac disorders and clinical characteristics, referred for clinical MRI studies, who were evaluated by cardiac MRI and 3DTTE. Our results show good correlation between the two modalities.

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.

-arginine improves endothelial function and reduces LDL oxidation in patients with stable coronary artery disease

BACKGROUND

We investigated the effects of oral L-arginine on endothelial function, intravascular oxidative stress, and circulating inflammatory markers in patients with stable coronary artery disease (CAD).

METHODS

Thirty-one stable CAD patients were randomly assigned to oral L-arginine (10 g) or vitamin C (500 mg, an antioxidant, as active control) daily for 4 weeks, with crossover to the alternate therapy after 2 weeks off therapy, in this study. Brachial artery endothelial function studies were performed and serum concentrations of lipids and inflammatory markers were measured at baseline, at the end of each 4-week treatment period and at the 2-week wash-out period. Susceptibility of low-density lipoprotein (LDL) particles to oxidation, a marker of oxidative stress, was determined in 11 patients at random before and after 4-week treatment of oral L-arginine.

RESULTS

We demonstrates that consumption of either L-arginine or vitamin C significantly increased brachial artery flow-mediated dilatation (mean diameter change from baseline of 4.87%, P<0.0001 and of 3.17%, P=0.0003, respectively). Neither oral L-arginine nor vitamin C affected lipid profiles and circulating levels of inflammatory markers. However, in the 11 patients whose LDL susceptibility to oxidation was determined, lag time significantly increased by 27.1% (P=0.045) after consumption of L-arginine for 4 weeks.

CONCLUSIONS

Oral L-arginine supplement improved endothelial function and reduced LDL oxidation in stable CAD patients.

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.

Independent prognostic value of elevated high-sensitivity C-reactive protein in chronic heart failure

BACKGROUND

The serum concentration of C-reactive protein (CRP) is mildly elevated in patients with chronic congestive heart failure (CHF), but this level falls well within the range found in healthy subjects. Standard clinical assays for CRP lack sensitivity within the low reference range and thus cannot be used effectively for routine clinical risk prediction. Because assays for high-sensitivity CRP (hsCRP) are now available, we can measure hsCRP to determine its predictive value for the prognosis of patients with CHF.

METHODS

Serum levels of hsCRP in 108 patients with CHF and left ventricular ejection fraction (LVEF) <50% were examined. Major adverse cardiac events (death, heart transplantation, or hospitalization with worsening heart failure) during a median follow-up period of 403 days were determined.

RESULTS

The concentrations of hsCRP in this study population were significantly increased with the severity of CHF. In a multivariate analysis, LVEF and serum levels of hsCRP were independent significant predictors for adverse outcomes in these patients (hazard ratio, 3.714, P =.024, and hazard ratio, 2.584, P =.047, respectively). However, hsCRP was minimally correlated with LVEF (r = -0.167, P =.084). Further analysis indicated that hsCRP might identify a different high-risk group and could improve risk stratification beyond that of LVEF.

CONCLUSIONS

These findings suggest that an elevated level of hsCRP is an independent predictor of prognosis in CHF and can provide additional prognostic information for the risk stratification and treatment in patients with chronic CHF.

Implantation of a passive fixation dual chamber pacemaker in a patient with persistent left superior vena cava

Electrode instability and displacement have been reported in patients who underwent pacemaker implantation via persistent left superior vena cava. An active-fixation system, and sometimes epicardial pacing, is necessary to maintain pacing stability. We report the case of a 76-year-old man with a left superior vena cava who required dual-chamber permanent pacing. Passive-fixation atrial and ventricular leads were successfully inserted and produced good long-term pacing and sensing. To the best of our knowledge, this is the first reported case of implantation of a dual-chamber pacemaker via persistent left superior vena cava in Taiwan.

The prognostic value of circulating soluble cell adhesion molecules in patients with chronic congestive heart failure

BACKGROUND

Circulating soluble (s) cell adhesion molecules (CAMs) are elevated in patients with congestive heart failure (CHF) and may play an important role in the pathogenesis of CHF by mediating the cell-cell interactions of the immune response. However, clinical data about the prognostic value of sCAMs are sparse. The purpose of this study is to determine whether various sCAMs can provide prognostic information in patients with CHF.

METHODS

We measured circulating levels of three sCAMs (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and sP-selectin) in 74 patients with symptomatic chronic CHF and left ventricular ejection fraction (LVEF) <50%. We compared these levels with those of a group of 19 age-matched control subjects. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening CHF) during a median follow-up period of 240 days were determined.

RESULTS

The concentrations of the three sCAMs in the 74 patients with CHF were significantly associated with one another. Their levels were higher than those of the control subjects and increased with the severity of CHF. Significantly higher sCAM levels were noted in those patients who had major adverse cardiac events during the follow-up period. There were significant negative correlations between LVEF and sCAMs. However, only high levels of sP-selectin were found to be an independent significant predictor of CHF by Cox proportional hazards analysis.

CONCLUSIONS

These findings indicate that the levels of these three sCAMs increase with the severity of CHF and are related to clinical outcomes. Among them, high levels of sP-selectin can provide prognostic information independently in patients with CHF.

Impairment of coronary microvascular function in patients with neurally mediated syncope

Recent evidence suggests that myocardial ischemia may occur in patients with neurally mediated syncope and normal coronary angiograms. This study was conducted to evaluate if coronary microvascular function is impaired in such patients. Coronary hemodynamic studies and head-up tilt table tests (HUTs) were performed on 30 consecutive patients with normal coronary angiograms and recurrent syncope. Another ten subjects with atypical chest pain and no evidence of myocardial ischemia or syncope served as a control. Great cardiac vein flow (GCVF) and coronary sinus flow (CSF) were measured by the thermodilution method at baseline and after dipyridamole infusion (0.56 mg/kg i.v. for 4 minutes). Coronary flow reserve (CFR), derived from CSF and GCVF, was significantly lower in the 15 patients with positive HUT than in the other 15 patients with negative HUT (1.75 +/- 0.48 vs 2.64 +/- 0.8, P < 0.01 and 2.29 +/- 0.45 vs 3.07 +/- 0.63, P < 0.01, respectively). Ischemic-like ECG was noted during treadmill exercise test in 40% of the former and in 7% of the latter group (P = 0.01). There was no significant difference in CFR between patients with negative HUT and control subjects. Coronary microvascular function was impaired in syncopal patients with positive HUT and relatively preserved in those with negative HUT, suggesting the possible linkage between coronary microvascular dysfunction and the development of neurally mediated syncope.

Safe right bundle branch block pattern during permanent right ventricular pacing

It is known that an electrocardiogram (ECG) after transvenous right ventricular (RV) pacing should yield left bundle branch block (LBBB) QRS patterns. When right bundle branch block (RBBB) pacing morphology appears in a patient with a permanent or temporary transvenous RV pacemaker, myocardial perforation or malposition of the pacing lead must be ruled out, even though the patient may be asymptomatic. We report a case of a 77-year-old man who underwent permanent transvenous VDD pacemaker implantation for symptomatic heart block. The postoperative ECG revealed a RBBB pacing configuration, but his chest X-ray and echocardiographic studies confirmed uncomplicated RV pacing. We review and discuss the literature concerning the differential diagnosis of such a safe RBBB ECG pattern.

Development of an echocardiographic method for choosing the best fitting single-pass VDD lead

To achieve stable single-lead VDD pacing, a selection of the electrode with the optimal distance between the lead tip and the floating atrial dipole (AV distance [AVD]) is important. The authors hypothesized that the size of the right heart chambers may affect atrial sensing, and that measurement of their internal dimension at end-diastole (RHIDd) in the apical four chamber view by transthoracic echocardiography may aid in choosing the proper AVD. Twenty-six consecutive cases that had undergone VDD pacer implantation using the conventional chest X ray were examined retrospectively by the echocardiographic method. The chest x-ray method properly selected a lead with optimal atrial sensing, defined as minimum P wave amplitude > or = 1.0 mV, for only 20 (77%) of 26 patients. By comparing these results with their respective RHIDd, a cut-off point of 13 cm was obtained that indicated a criterion for choosing the proper AVD. The indication was that if the RHIDd was > or = 13 cm, a lead with an AVD of 15.5/16 cm should have been used; if the RHIDd was < 13 cm, a lead with an AVD of 13/13.5 cm should have been chosen. Using the echocardiographic method, all six patients who had suboptimal atrial sensing could be identified and classified as having missized (four undersized; two oversized) permanent leads. In conclusion, the described method provides a promising preoperative assessment of the best fitting electrode length in single lead VDD pacing. A prospective study is ongoing to verify its applicability.

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.