Session End Research Articles

산업 안전 서비스를 위한 셰퍼드 기반의 SIP 환경

본 논문은 산업 안전 서비스를 위하여 컴퓨터 지원 협동 작업의 하나의 환경을 제안한다. 산업 안전 환경의 좋은 예는 화약고이다. 본 논문에서는 산업안전 서비스를 위한 셰퍼드와 세션 초기 프로토콜 환경에서 실행되는 컴퓨터 기반의 멀티미디어 통합 환경에 대해서 제안하였다. 기존의 멀티미디어 프레임워크는 컴퓨터 기반의 멀티미디어 통합을 위한 세션 초기 프로토콜 환경에서 거의 없는 실정이다. 본 논문에서는 세션을 잘 유지할 수 있게 하기 위하여 셰퍼드와 세션 초기 프로토콜 환경에서 실행되는 컴퓨터 기반의 멀티미디어 통합 환경을 기술하였다. This paper suggests an environment of a CSCW(Computer Supported Cooperative Works) for industry safety service. A good example of industry safety service is gunpowder. This paper proposed a computer-based integrated multimedia for industry safety service running on shepherd and SIP(Session Initiation Protocol). But, conventional framework has not yet fully progressed a shepherd for computer-based integrated multimedia running on SIP(Session Initiation Protocol). Session management include function of session creation, session end, late comer process, and access control. Therefore, this paper described an environment of integrated multimedia based on a shepherd and SIP environment to maintain good session condition.

Chronotype and Improved Sleep Efficiency Independently Predict Depressive Symptom Reduction after Group Cognitive Behavioral Therapy for Insomnia.

Cognitive behavioral therapy for insomnia (CBT-I) has been shown to improve both sleep and depressive symptoms, but predictors of depression outcome following CBT-I have not been well examined. This study investigated how chronotype (i.e., morningness-eveningness trait) and changes in sleep efficiency (SE) were related to changes in depressive symptoms among recipients of CBT-I. Included were 419 adult insomnia outpatients from a sleep disorders clinic (43.20% males, age mean ± standard deviation = 48.14 ± 14.02). All participants completed the Composite Scale of Morningness and attended at least 4 sessions of a 6-session group CBT-I. SE was extracted from sleep diary; depressive symptoms were assessed using the Beck Depression Inventory (BDI) prior to (Baseline), and at the end (End) of intervention. Multilevel structural equation modeling revealed that from Baseline to End, SE increased and BDI decreased significantly. Controlling for age, sex, BDI, and SE at Baseline, stronger evening chronotype and less improvement in SE significantly and uniquely predicted less reduction in BDI from Baseline to End. Chronotype did not predict improvement in SE. In an insomnia outpatient sample, SE and depressive symptoms improved significantly after a CBT-I group intervention. All chronotypes benefited from sleep improvement, but those with greater eveningness and/or less sleep improvement experienced less reduction in depressive symptom severity. This suggests that evening preference and insomnia symptoms may have distinct relationships with mood, raising the possibility that the effect of CBT-I on depressive symptoms could be enhanced by assessing and addressing circadian factors.

컴퓨터 기반의 통합 멀티미디어를 위한 원격 환경 상에서 접근 제어에 관한 연구

본 논문에서는 셰퍼드와 세션 초기 프로토콜 환경에서 실행되는 컴퓨터 기반의 멀티미디어 통합을 위한 접근 제어에 대해서 제안하였다. 기존의 멀티미디어 프레임워크는 접근제어에 대한 기능은 있지만, 컴퓨터 기반의 멀티미디어 통합을 위한 세션 초기 프로토콜 환경에서 거의 없는 실정이다. 세션 관리에는 세션의 생성, 종료 및 지각자처리, 접근제어 등의 기능이 있다. 본 논문에서는 세션을 잘 유지할 수 있게 하기 위하여 셰퍼드와 세션 초기 프로토콜 환경에서 실행되는 컴퓨터 기반의 멀티미디어 통합을 위한 접근제어를 기술하였다. This paper proposed an access control for computer-based integrated multimedia running on shepherd and SIP(Session Initiation Protocol). But, conventional framework for access control SIP environment has not yet fully progressed a shepherd and an access control for computer-based integrated multimedia running on SIP(Session Initiation Protocol). Session management include function of session creation, session end, late comer process, and access control. Therefore, this paper described access control based on a shepherd and SIP environment to maintain good session condition.

Impact d’un programme d’amélioration de la stabilité de l’épuration extrarénale continue

ObjectivesDuring continuous renal replacement therapy (CRRT), circuit clotting increases nursing workload, cost of the therapy and blood loss. The aim of this study was to assess the impact of a program designed to improve CRRT stability on unexpected circuit clotting. Study designRetrospective and observational study. Patients and methodsIn January 2011, several changes have been adopted regarding CRRT management. Regional citrate anticoagulation, continuous hemodialysis using super high-flux membranes and a specific training for intensive care unit nurses were implemented. CRRT sessions before (year 2009 and 2010, “Before group”) and after (year 2011 and 2012, “After group”) were analyzed. The primary endpoint was the incidence of unexpected CRRT session end. ResultsDuring the study period, 401 sessions performed in 152 patients were analyzed. Sixty-three unexpected session's end (40%) occurred before and 43 (17%) after the implementation of the program (P<0.0001). Median filter life time was 33 (13–48) hours before and 55 (27–67) hours after (P<0.0001). ConclusionOur program designed to improve CRRT stability reduced filter losses by reducing unexpected circuit clotting.

Unobtrusive measurement of daily computer use to detect mild cognitive impairment

BackgroundMild disturbances of higher order activities of daily living are present in people diagnosed with mild cognitive impairment (MCI). These deficits may be difficult to detect among those still living independently. Unobtrusive continuous assessment of a complex activity such as home computer use may detect mild functional changes and identify MCI. We sought to determine whether long-term changes in remotely monitored computer use differ in persons with MCI in comparison with cognitively intact volunteers. MethodsParticipants enrolled in a longitudinal cohort study of unobtrusive in-home technologies to detect cognitive and motor decline in independently living seniors were assessed for computer use (number of days with use, mean daily use, and coefficient of variation of use) measured by remotely monitoring computer session start and end times. ResultsMore than 230,000 computer sessions from 113 computer users (mean age, 85 years; 38 with MCI) were acquired during a mean of 36 months. In mixed-effects models, there was no difference in computer use at baseline between MCI and intact participants controlling for age, sex, education, race, and computer experience. However, over time, between MCI and intact participants, there was a significant decrease in number of days with use (P = .01), mean daily use (∼1% greater decrease/month; P = .009), and an increase in day-to-day use variability (P = .002). ConclusionsComputer use change can be monitored unobtrusively and indicates individuals with MCI. With 79% of those 55 to 64 years old now online, this may be an ecologically valid and efficient approach to track subtle, clinically meaningful change with aging.

Dalteparin Dosing in High-Flux Haemodialysis and Haemodiafiltration

Background: Low-molecular-weight heparins are being increasingly used as an alternative to unfractionated heparin for anticoagulation of the haemodialysis (HD) circuit. Data on dalteparin use in high-flux HD and haemodiafiltration (HDF) are limited. We examined the safety and efficacy of dalteparin in this setting to enable recommendations on the optimal dose range. Methods: This prospective study was conducted in a single dialysis unit. Subjects who had been receiving dalteparin for at least 10 HD sessions were studied. Anti-Xa activity was measured for all subjects at the start of the HD session, at 60 min into HD and at the end of dialysis. Results: 55 subjects were studied. None had detectable anti-Xa activity at the start of the session. Using adequacy criteria based on target anti-Xa activity >0.4 IU/ml at 1 h and <0.4 IU/ml at the end of dialysis, 39 (71%) patients had adequate anticoagulation, 12 (22%) patients were under-anticoagulated and 4 (7%) were over-anticoagulated. The mean dose in the adequately anticoagulated group was 60.7 ± 11.7 IU/kg, in the under-anticoagulated group 39.3 ± 9.6 IU/kg and in the over-anticoagulated group 70.1 ± 14.6 IU/kg. The optimal dose of dalteparin appears to be 60 ± 10 IU/kg, which facilitates the achievement of the target anti-Xa activity in the range of 0.4-0.75 IU/ml at 1 h and <0.4 IU/ml at the session end. Conclusion: Dalteparin is a safe and effective anticoagulant for patients on high-flux HD and HDF. The optimal dose appears to be 60 ± 10 IU/kg. The desirable target range of anti-Xa activity is 0.4-0.75 at 1 h and <0.4 IU/ml at the session end.

A randomized, controlled pilot study of MDMA (±3,4-Methylenedioxymethamphetamine)-assisted psychotherapy for treatment of resistant, chronic Post-Traumatic Stress Disorder (PTSD)

Psychiatrists and psychotherapists in the US (1970s to 1985) and Switzerland (1988-1993) used MDMA legally as a prescription drug, to enhance the effectiveness of psychotherapy. Early reports suggest that it is useful in treating trauma-related disorders. Recently, the first completed pilot study of MDMA-assisted psychotherapy for PTSD yielded encouraging results. Designed to test the safety and efficacy of MDMA-assisted psychotherapy in patients with treatment-resistant PTSD; our randomized, double-blind, active-placebo controlled trial enrolled 12 patients for treatment with either low-dose (25 mg, plus 12.5 mg supplemental dose) or full-dose MDMA (125 mg, plus 62.5 mg supplemental dose). MDMA was administered during three experimental sessions, interspersed with weekly non-drug-based psychotherapy sessions. Outcome measures used were the Clinician-Administered PTSD Scale (CAPS) and the Posttraumatic Diagnostic Scale (PDS). Patients were assessed at baseline, three weeks after the second and third MDMA session (end of treatment), and at the 2-month and 1-year follow-ups. We found that MDMA-assisted psychotherapy can be safely administered in a clinical setting. No drug-related serious adverse events occurred. We did not see statistically significant reductions in CAPS scores (p = 0.066), although there was clinically and statistically significant self-reported (PDS) improvement (p = 0.014). CAPS scores improved further at the 1-year follow-up. In addition, three MDMA sessions were more effective than two (p = 0.016).

Heparin‐grafted dialysis membrane allows minimal systemic anticoagulation in regular hemodialysis patients: A prospective proof‐of‐concept study

This prospective, multicenter, proof-of-concept study aimed to evaluate the possibility to reduce the ordinary heparin dose and the systemic anti-Xa activity during hemodialysis (HD) sessions using a new heparin-grafted HD membrane. In 45 stable HD patients, the use of a heparin-grafted membrane with the ordinary heparin dose was followed by a stepwise weekly reduction of dose. Reduction was stopped when early signs of clotting (venous pressure, quality of rinse-back) occurred during two out of three weekly HD sessions. Heparin dose was decreased for 67% of patients resulting in the lowering of these patients' anti-Xa activity by 50%. Dose reductions were achieved with both types of heparin (low-molecular-weight heparin: 64 ± 14 to 35 ± 12 IU/kg, P < 0.0001; unfractionated heparin: 82 ± 18 to 46 ± 13 IU/kg, P < 0.0001) resulting in a decrease of anti-Xa activity at dialysis session end (low-molecular-weight heparin: 0.51 ± 0.25 to 0.25 ± 0.11 IU/mL, P < 0.0001; unfractionated heparin: 0.28 ± 0.23 to 0.13 ± 0.07 IU/mL, P < 0.0001). Failure to further decrease heparin dose was related to signs of clotting in blood lines (57% of sessions), in dialyzer (9%), or both (34%). Significant reduction of heparin dose and anti-Xa activity at the end of HD sessions was possible in stable HD patients using heparin-grafted membrane. HD patients who require low anti-Xa activity at the end of HD sessions might benefit from a heparin-grafted membrane to reduce bleeding risk and other heparin adverse events.

Time preferences in long-tailed macaques (Macaca fascicularis) and humans (Homo sapiens)

Rosati et al. (Curr Biol 17(19):1663-1668, 2007) found in a self-control test in which choice was between a smaller, immediately delivered food and a larger, delayed food, that chimpanzees preferred the larger reward (self-control); humans, however, preferred the smaller reward (impulsivity). They attributed their results to a species difference in self-control. In Experiment 1, monkeys (long-tailed macaques) were exposed to a self-control task in two conditions: where the food was hidden under differently colored bowls and where it was visible. When these two conditions were compared, choice shifted from greater preference for the impulsive alternative in the hidden condition to greater preference for the self-control alternative in the visible condition. Additionally, in both conditions, preference shifted from self-control to impulsivity over sessions. These results were explained in terms of the reversed-contingency effect (a propensity to reach for more over less when rewards are visible) and not to a capacity for self-control. In Experiment 2, humans that demonstrated preference for more over less in choice preferred the impulsive alternative when choice to either alternative was followed by the same intertrial interval-a preference that accelerates trial rates relative to preference of the self-control alternative. When trial rates were equated so that neither choice accelerated session's end, humans demonstrated self-control. These results suggest that Rosati et al.'s demonstration of impulsivity in humans was due to participants' desire to minimize session time.

Education in mental health promotion and its impact on the participants' attitudes and perceived mental health.

BackgroundAlthough the promotion of mental health (MHP) through education and training is widely accepted, there is scarce evidence for its effectiveness in the literature from outcome studies worldwide. The present study aimed to assess the effect of a three-semester MHP educational program on the recipients' opinions towards mental illness and on their own self-assessed health.MethodsRespondents were 78 attendees who completed the assessment battery at the first (baseline) and the last session (end) of the training course. They were primary care physicians or other professionals, or key community agents, working in the greater Athens area. The course consisted of 44 sessions (4 h each), over a 3-semester period, focusing on the principles and methods of mental health promotion, the main aspects of major psychiatric disorders, and on relevant to health skills. Assessment instruments included the Opinion about Mental Illness (OMI) scale and the General Health Questionnaire (GHQ-28).ResultsThe mean scores of three OMI factors, that is, social discrimination, social restriction and social integration, and the two GHQ-28 subscales, that is, anxiety/insomnia and social dysfunction, were significantly improved by the end of the training course.ConclusionsThe results of this study provide evidence, with limitations, for the short-term effectiveness of the implemented educational MHP program on an adult group of recipients-key agents in their community. Because interventions for strengthening positive opinions about mental illness and enhancing self-assessed health constitute priority aims of mental health promotion, it would be beneficial to further investigate the sustainability of the observed positive changes. In addition it would be useful to examine (a) the possible interplay between the two outcome measures, that is, the effect of opinions of recipients about mental health on their perceived health, and (b) the applicability of this intervention in individuals with different sociodemographic profiles.

Waterpipe Tobacco and Cigarette Smoking: Direct Comparison of Toxicant Exposure

Waterpipe (hookah, shisha) tobacco smoking has spread worldwide. Many waterpipe smokers believe that, relative to cigarettes, waterpipes are associated with lower smoke toxicant levels and fewer health risks. For physicians to address these beliefs credibly, waterpipe use and cigarette smoking must be compared directly. The purpose of this study is to provide the first controlled, direct laboratory comparison of the toxicant exposure associated with waterpipe tobacco and cigarette smoking. Participants (N=31; M=21.4 years, SD=2.3) reporting monthly waterpipe use (M=5.2 uses/month, SD=4.0) and weekly cigarette smoking (M=9.9 cigarettes/day, SD=6.4) completed a crossover study in which they each smoked a waterpipe for a maximum of 45 minutes, or a single cigarette. Outcome measures included expired-air carbon monoxide (CO) 5 minutes after session's end, and blood carboxyhemoglobin (COHb), plasma nicotine, heart rate, and puff topography. Data were collected in 2008-2009 and analyzed in 2009. On average, CO increased by 23.9 ppm for waterpipe use (SD=19.8) and 2.7 ppm for cigarette smoking (SD=1.8), while peak waterpipe COHb levels (M=3.9%, SD=2.5) were three times those observed for cigarette smoking (M=1.3%, SD=0.5; p's<0.001). Peak nicotine levels did not differ (waterpipe M=10.2 ng/mL, SD=7.0; cigarette M=10.6 ng/mL, SD=7.7). Significant heart rate increases relative to pre-smoking were observed at 5, 10, 15, 20, 25, and 35 minutes during the cigarette session and at 5-minute intervals during the waterpipe session (p's<0.001). Mean total puff volume was 48.6 L for waterpipe use as compared to 1.0 L for cigarette smoking (p<0.001). Relative to cigarette smoking, waterpipe use is associated with greater CO, similar nicotine, and dramatically more smoke exposure. Physicians should consider advising their patients that waterpipe tobacco smoking exposes them to some of the same toxicants as cigarette smoking and therefore the two tobacco-smoking methods likely share some of the same health risks.

Simulation in coronary artery anastomosis early in cardiothoracic surgical residency training: The Boot Camp experience

We evaluated focused training in coronary artery anastomosis with a porcine heart model and portable task station. At "Boot Camp," 33 first-year cardiothoracic surgical residents participated in 4-hour coronary anastomosis sessions (6-7 attending surgeons per group of 8-9 residents). At beginning, midpoint, and session end, anastomosis components were assessed on a 3-point rating scale (1 good, 2 average, 3 below average). Performances were video recorded and reviewed by 3 surgeons in a blinded fashion. Participants completed questionnaires at session end, with follow-up surveys at 6 months. Ten to 18 end-to-side anastomoses with porcine model and task station were performed. Initial assessments ranged from 2.11 +/- 0.58 (forceps use) to 2.44 +/- 0.48 (needle angles). Midpoint scores ranged from 1.76 +/- 0.63 (forceps use) to 1.91 +/- 0.49 (needle angles). Session end scores ranged from 1.29 +/- 0.45 (needle holder use) to 1.58 +/- 0.50 (needle transfer and suture management and tension; P < .001). Video recordings confirmed improved performance (interrater reliability >0.5). All respondents agreed that task station and porcine model were good methods of training. At 6 months, respondents noted that the anastomosis session provided a basis for training; however, only slightly more than half continued to practice outside the operating room. Four-hour focused training with porcine model and task station resulted in improved ability to perform anastomoses. Boot Camp may be useful in preparing residents for coronary anastomosis in the clinical setting, but emphasis on simulation development and deliberate practice is necessary.

Abstract: P186 OSTEOPONTIN IS PIVOTAL FOR DEVELOPMENT OF UREMIC ATHEROSCLEROSIS

Low TGF-β1 serum levels are a risk factor for atherosclerosis disease in ESRD patients.It is thought that transforming growth factor-β1 (TGF-β1) might be a key inhibitor of atherogenesis in non-uremic patients. We evaluated the intra- and post-dialytic serum levels of TGF-β1 in uremic patients to assess if TGF-β1 is an independent risk factor for cardiovascular diseases, and if any correlation exists between TGF-β1 and any yet known atherosclerotic risk factors.We studied 155 patients who were on regular hemodialysis, with or without clinically significant atherosclerotic vascular disease. Forty-one apparently healthy people were enrolled as a control group. TGF-β1 was evaluated during the midweek dialysis session, at times 0, 30, and 120 minues, at the end of the session, and 3 hours after the session's end. All hitherto known atherosclerotic risk factors also were evaluated. The investigation was performed over a 24-month follow-up.TGF-β1 values (mean ± SD) in dialysis patients were 26.64 ± 7.0 ng/mL (N = 155) compared with 42.31 ± 6.0 ng/mL in the control group (N = 41, P < 0.0001). A weak inverse correlation emerged between TGF-β1 and age (r = -0.28), TGF-β1 and lipoprotein(a) [Lp(a); r = -0.35], TGF-β1 and C-reactive protein (CRP; r = -0.27), and TGF-β1 and plasminogen activator inhibitor-1 (PAI-1; r = -0.41). TGF-β1 also correlated with albumin (r = 0.31). In the coronary heart disease (CHD) group (N = 32) the TGF-β1 was 26.2 ± 4.9 ng/mL; in the cerebrovascular disease (CVD) group (N = 8) it was 26.7 ± 3.7 ng/mL and in the peripheral vascular disease (PVD) group (N = 9) it was 25.4 ± 1.7 ng/mL. In dialysis patients with no cardiovascular disease (N = 80) TGF-β1 was 35.1 ± 6.8 ng/mL (P < 0.0001 vs. CHD, CVD and PVD patients). TGF-β1 was significantly lower among those patients with triple coronary vessel disease than with the other CHD patients. The Cox analysis demonstrated that a 1 ng/mL reduction in TGF-β1 concentration was associated with a 9% increase in the relative risk of a cardiovascular event.TGF-β1 was significantly reduced in hemodialysis patients, in particular in those with severe cardiovascular disease. Baseline TGF-β1, diabetes mellitus and serum albumin levels proved to be the only independent contributors to atherosclerotic risk in dialysis patients.

FORWARD-LOOKING SESSIONS FEATURED IN EDUCATIONAL PROGRAM IN DALLAS

FORWARD-LOOKING SESSIONS FEATURED IN EDUCATIONAL PROGRAM IN DALLAS

Continuous Monitoring of Left Ventricle Function by VEST in Hemodialyzed Patients

Cardiovascular disease is a major cause of morbidity and mortality in chronic kidney disease. Radionuclide-based methods can be used for analyses on the perfusion of coronary arteries and ventricular function. The present study reports the use of a new procedure for continuous measurements of left ventricle function during a dialytic session with the use of a recently developed portable gamma radiation detector (ventricular function study system). On average, left ventricle ejection fraction and stroke volume progressively and continuously decreased throughout the session (end session versus baseline: -13.8% for ejection fraction, -25.9% for stroke volume, P<.02). A biphasic response was found for heart rate: a transient modest decrease (at session midpoint, -4.2%) followed by an increase up to values higher than baseline (end session, +4.7%). Cardiac output decreased by 10.4% at session midpoint (P=.023 versus baseline) without further reduction in the following hours. Mean changes in systolic pressure paralleled data for cardiac output. Individual changes in indices of left ventricle function were scattered and strongly were correlated with thickness of interventricular septum and telediastolic left ventricular volume measured by standard echocardiogram in the interdialytic period (R>.75, P<.05). Data indicate that the ventricular function study system could be a powerful tool for characterization of the profile of left ventricular function in hemodialyzed patients.

SESSION 7B Palliative and End of Life Care

Background: Being told that one has a life threatening disease is shattering, but for some people it comes as a relief, following as it does the years of uncertainty and traumatic experiences that lead to diagnosis. The need to debrief the experience is paramount before the story of living with the disease can be told. Objectives: The purpose of this paper is to describe the extended and often demoralising process of diagnosis for people with ALS/MND. Methods: Grounded theory methodology was used to explore the life and world of people diagnosed and living with ALS/MND. Data were collected via in-depth interviews with 25 people with the disease, their stories and photographs, poems and books they identified as important, and field notes. The textual data were analysed using constant comparative analysis. All people who volunteered were included in the study. Many participants with communication challenges worked with the researcher to tell their stories. Results: Participants recounted the processes they experienced prior to the time when they were finally given a reason for the perplexing behaviour of their bodies. The diagnosis story was revealed as a sequence of: ‘recognizing a problem’, ‘seeking medical help’, ‘being on the diagnostic roundabout’, ‘confirming ALS/MND’, ‘reevaluating life and the future’, then ‘living with ALS/MND’. Consequences included a loss of trust in the competence of the health care system, which had implications for seeking help later when living with the disease. Discussion: Participant distress seemed to have more in common with the stress linked to post-traumatic stress disorder (PTSD). Participants continued to relive the diagnosis experience in their dreams and daily lives many months after diagnosis, which impacted negatively on their well-being. For this group of people, the diagnostic process itself was the traumatic stressor. It seemed that telling their stories gave them the opportunity to debrief and have their words recorded. Debrief support is recommended whenthe ALS/MND diagnosis is finalized, and continued, to prevent long-term reliving of the diagnostic process. Conclusion: Health professionals continue to address the issues around the process of giving the ‘bad news’ of ALS/MND. This ‘diagnosis story’ may provide additional guidance in addressing the process so as to limit potential harm and promote well-being for people with the disease and their families.

QTc interval and QTc dispersion during haemodiafiltration

Our aim was to evaluate QTc interval and QTc dispersion in 27 end-stage renal disease (ESRD) patients undergoing Acetate Free Biofiltration (AFB) in order to ascertain any correlations between the electrrocardiographic (ECG) parameters, serum Na+, K+, Ca++, Mg++ and intraerythrocytic Mg++ (Mg++e) concentrations. All measures were made at t0 (session beginning), t1 (first hour), t2 (second hour), t3 (third hour), and t4 (session end). Blood pressure, heart rate, bodyweight and total ultrafiltration in the three dialysis sessions were constant. A significant progressive increase occurred in serum Ca++ during the sessions, while there was a significant diminution in serum K+. The pattern for Mg++ concentrations in serum and erythrocytes differed: in serum it decreased, whereas Mg++e increased. At t4, the QTc interval was reduced to a significant extent with respect to the baseline value. QTc dispersion significantly increased at t1 without there being significant variations at other times with respect to t0. At t2, t3 and t4, values promptly returned to baseline levels. QTc had a negative correlation with serum Ca++ levels at t4. In contrast, an inverse correlation was found between QTc dispersion and serum K+ at t1. No other correlations could be found between any other electrolytes, QTc interval or QTc dispersion. In conclusion, the decrease observed in the QTc interval at the end of an AFB session was inversely related to serum Ca++ concentrations. Moreover, an increase in QTc dispersion occurred during the first hour of the session, and was negatively correlated with serum K+.

Low TGF-β1 serum levels are a risk factor for atherosclerosis disease in ESRD patients

It is thought that transforming growth factor-beta1 (TGF-beta1) might be a key inhibitor of atherogenesis in non-uremic patients. We evaluated the intra- and post-dialytic serum levels of TGF-beta1 in uremic patients to assess if TGF-beta1 is an independent risk factor for cardiovascular diseases, and if any correlation exists between TGF-beta1 and any yet known atherosclerotic risk factors. We studied 155 patients who were on regular hemodialysis, with or without clinically significant atherosclerotic vascular disease. Forty-one apparently healthy people were enrolled as a control group. TGF-beta1 was evaluated during the midweek dialysis session, at times 0, 30, and 120 minues, at the end of the session, and 3 hours after the session's end. All hitherto known atherosclerotic risk factors also were evaluated. The investigation was performed over a 24-month follow-up. TGF-beta1 values (mean +/- SD) in dialysis patients were 26.64 +/- 7.0 ng/mL (N=155) compared with 42.31 +/- 6.0 ng/mL in the control group (N=41, P < 0.0001). A weak inverse correlation emerged between TGF-beta1 and age (r=-0.28), TGF-beta1 and lipoprotein(a) [Lp(a); r=-0.35], TGF-beta1 and C-reactive protein (CRP; r=-0.27), and TGF-beta1 and plasminogen activator inhibitor-1 (PAI-1; r=-0.41). TGF-beta1 also correlated with albumin (r=0.31). In the coronary heart disease (CHD) group (N=32) the TGF-beta1 was 26.2 +/- 4.9 ng/mL; in the cerebrovascular disease (CVD) group (N=8) it was 26.7 +/- 3.7 ng/mL and in the peripheral vascular disease (PVD) group (N=9) it was 25.4 +/- 1.7 ng/mL. In dialysis patients with no cardiovascular disease (N=80) TGF-beta1 was 35.1 +/- 6.8 ng/mL (P < 0.0001 vs. CHD, CVD and PVD patients). TGF-beta1 was significantly lower among those patients with triple coronary vessel disease than with the other CHD patients. The Cox analysis demonstrated that a 1 ng/mL reduction in TGF-beta1 concentration was associated with a 9% increase in the relative risk of a cardiovascular event. TGF-beta1 was significantly reduced in hemodialysis patients, in particular in those with severe cardiovascular disease. Baseline TGF-beta1, diabetes mellitus and serum albumin levels proved to be the only independent contributors to atherosclerotic risk in dialysis patients.

Stimulus control and generalization of point-loss punishment with humans.

Two experiments demonstrated stimulus control and generalization of conditioned punishment with humans. In both studies, responses first were reinforced with points exchangeable for money on a variable-interval schedule in the presence of one line length (S(D)). Next, a second line length was introduced, and point loss followed every response in the presence of that line (S(D)p). In the final training condition, points were deducted at session end. Response rate was lower in the presence of the S(D)p despite equal rates of points for money in the presence of both stimuli. In generalization testing for Experiment 1, the two lines were included in a 10-line continuum; S(D)p fell in the middle and the trained SD was at one end. Lines were presented randomly, and point delivery and loss contingencies were as in training but with points available in the presence of all lines. For all subjects, response rates were lowest around S(D)p and increased towards the SD end of the continuum. Because testing included only one or two lines beyond S(D), this pattern did not rule out S(D) generalization. Thus, in Experiment 2, stimuli beyond S(D) were added to generalization tests. Response rates did not decrease as a function of distance from S(D), clarifying the demonstration of punishment generalization.

Effects of Dialysis Membrane Nature on Intradialytic Phagocytizing Activity

Blood-membrane contact in the extracorporeal circuit affects the activation of many biological systems. Among these, phagocytizing activity has been reported to be influenced by the nature of the hemodialysis membrane used, whether cellulosic or synthetic. This work reports on an ex-vivo, comparative test between cellulosics and synthetics concerning the effects of blood-membrane contact on the polymorphonucleate and monocyte phagocytizing function, both during and after the hemodialysis session. By means of flow cytometry, we evaluated the capacity for phagosoma formation and oxidative burst both in polymorphonucleates and monocytes. Ten hemodialysis patients were included in the study. Six separate dialysis procedures for each patient were considered, one per dialyzer (3 cellulosic and 3 synthetic membranes). Tests were performed at 15', 60', 210' and 4 hours after the session end. Comparative evaluation was made according to Student's t test. Polymorphonucleate phagocytosis and oxidative burst activation were globally more marked for synthetic than cellulosic membranes, tending to level out in the post-dialysis. This result could be affected by their functional exhaustion following pulmonary sequestration. Monocyte intradialytic phagocytosis and oxidative burst proved more activated by cellulosic membrane. All differences tended to vanish in the post-dialysis.