Effects of APB,PDA, and TTX on ERG responses recorded using both multifocal and conventional methods in monkey. Effects of APB,PDA, and TTX on monkey ERG responses

Results from studies of human subjects suggest that the multifocal ERG technique developed by Erich Sutter and colleagues has considerable potential for assessment of retinal function in both the clinic and laboratory. While the utility of this measure depends to a large extent upon an understanding of the physiological origin for the different response components, relatively little is known in this regard. For the experiments described in this report, we made ERG recordings using both multifocal and conventional methods. Intravitreal injections of APB, PDA, and TTX were used to identify contributions from activity in ON pathway, OFF pathway, and third order retinal neurons, respectively. The results show that photoreceptor activity makes a small direct contribution to 1st and 2nd order multifocal photopic luminance responses. TTX-sensitive activity in third order retinal neurons contributes to both 1st and 2nd order responses with relatively greater contribution to the 2nd order response. Blockade of TTX-sensitive activity in third order cells produces effects on the 2nd order response which are very similar to changes observed in eyes suffering selective loss of retinal ganglion cells resulting from experimental glaucoma. Effects of these intravitreally injected test agents were also determined, in the same recording session, for flash, 30 Hz flicker, and oscillatory potential responses.     

The evaluation of the introduction of a quality management system: a process-oriented case study in a large rehabilitation hospital

OBJECTIVES: So far, there is limited proof concerning the effects of the introduction of quality management systems (QMS) on organisational level. This study concerns the introduction of a QMS in a large rehabilitation hospital. METHODS: Using an observational framework, a process-analysis is performed. The effects were analysed with repeated analyses using the Dutch version of the EFQM-model. RESULTS: The introduction of a QMS can be seen as a change process; the pre-change diagnosis proved to be essential. Although many change-related aspects are vital, training and communication, in particular, seemed to be underestimated. Outcomes are a positive correlation between participation in quality activities and work satisfaction and a repeatedly favourable EFQM-score (compared to national levels). CONCLUSIONS: Through a process-analysis, information could be generated to guide organisations in introducing a QMS. An outcome analysis revealed positive effects both in the EFQM-score and the staff's work satisfaction.     

Angiotensin-converting enzyme inhibitor-enhanced phase-contrast MR imaging to measure renal artery velocity waveforms in patients with suspected renovascular hypertension

OBJECTIVE: We investigated the usefulness of phase-contrast MR imaging to measure renal artery velocity waveforms as an adjunct to renal MR angiography. We also examined whether an angiotensin-converting enzyme (ACE) inhibitor improves the diagnostic accuracy of waveform analysis. SUBJECTS AND METHODS: Thirty-five patients referred for MR angiography of renal arteries underwent non-breath-hold oblique sagittal velocity-encoded phase-contrast MR imaging through both renal hila (TR/TE, 24/5; flip angle, 30 degrees; signal averages, two; encoding velocity, 75 cm/sec) before and after i.v. administration of an ACE inhibitor (enalaprilat). We analyzed velocity waveforms using established Doppler sonographic criteria. A timing examination with a test bolus of gadolinium contrast material was performed to ensure optimal arterial enhancement during breath-hold gadolinium-enhanced three-dimensional gradient-echo MR angiography. RESULTS: MR phase-contrast waveform pattern analysis was 50% (9/18) sensitive and 78% (40/51) specific for the detection of renal artery stenosis equal to or greater than 60% as shown on MR angiography. Sensitivity (67%, 12/18) and specificity (84%, 42/50) increased slightly, but not significantly, after i.v. administration of an ACE inhibitor. Also, the accuracy of quantitative criteria such as acceleration time and acceleration index did not improve after the administration of ACE inhibitor. CONCLUSION: Renal hilar velocity waveforms, measured using non-breath-hold MR phase-contrast techniques with or without an ACE inhibitor, are insufficiently accurate to use in predicting renal artery stenosis.     

The interval from surgery to chemotherapy in the treatment of advanced epithelial ovarian carcinoma.

BACKGROUND: To study the effect of the interval between surgery and the start of chemotherapy in the treatment of patients with advanced ovarian cancer. METHODS: We stratified patients according to the start of platinum-based chemotherapy in group 1 (within 4 weeks from surgery), group 2 (between 4 and 8 weeks) and group 3 (between 8 and 12 weeks). RESULTS: Three hundred and ninty-four stage III ovarian cancer patients were analysed. In the multivariate analysis there were no differences in survival according to the interval between surgery and chemotherapy among the three groups. The independent prognostic variables were type of procedure (p = 0.014), performance status (p = 0.040) and post-chemotherapy CA-125 (p < 0.0001). CONCLUSIONS: The interval between surgery and chemotherapy does not affect outcome.     

Accuracy of helical CT for acute pulmonary embolism: ROC analysis of observer performance related to clinical experience

The aim of this study was to test the influence of observer experience on the accuracy for interpreting helical CT for acute pulmonary embolism (PE) and to identify sources of observer errors. Three observers of different expertise blindly assessed 147 helical CT scans for suspected PE (true status regarding absence or presence of PE known from independent reference studies). These observers were (a) an experienced CT radiologist, (b) a fellow in CT, and (c) a second-year resident without any formal training in CT. None of them had prior experience with CT for PE. Firstly, 70 CT scans were scored without revealing true PE status. Afterwards, feedback was provided and another 77 CT scans were evaluated. The CT scans were scored on a 5-point confidence scale and receiver-operator-characteristic analysis was performed. Different sources of interpretation errors were analyzed. The two observers with CT experience were significantly more accurate than the unexperienced observer. Their performance was not influenced by feedback training. Certain observer errors were identified, but there was no clear difference among the three observers considering the type of errors. There is significant influence of observer experience on accuracy of reading helical CT for PE: A basic working experience with whole-body CT seems to be a prerequisite. These results suggest that with this experience any radiologist should be able to achieve good accuracy; helical CT thus might become a suitable technique for acute PE in routine clinical practice. Received 7 April 1997; Revision received 30 June 1997; Accepted 20 January 1998     

Implementation of an innovative health service a "real-world" diffusion study

BACKGROUND: Although reporting on the healthcare-setting level of continuance or discontinuance of an intervention once a trial is completed has been recommended, such "real-world" diffusion studies are rare. The present example was made possible by funding to explore opportunities for post-trial implementation of an innovative health counseling intervention for cardiovascular prevention in The Netherlands. METHODS: Between 2001 and 2004, in a longitudinal case study, we compared two healthcare settings: a cardiology outpatient clinic and general practices. Rogers' diffusion of innovations theory served as the theoretical background. Information was extracted from minutes of meetings and informal conversations with health counselors, and checked by the project manager. Additional data were collected from physicians with a short questionnaire. RESULTS: Implementation of the health counseling intervention was successful in the cardiology outpatient clinic, but was unsuccessful in the general practices. Success was related to a centralized diffusion system, stronger "change agent" efforts, avoidance of post-trial interruption of service delivery, easily achievable "reinventions," and positive physician perceptions of the service (i.e., not complex and compatible with current practice routines). Support came from changes in the organization of care that created opportunities for, instead of competition with, the innovative service. However, coincidental events may also have played a part. CONCLUSIONS: Our findings confirm the importance of most theoretically predicted individual and organizational diffusion variables. This implies that the implementation of innovative healthcare services requires attention at both levels.     

Rosiglitazone improves postprandial triglyceride and free fatty acid metabolism in type 2 diabetes

OBJECTIVE: Increased postprandial lipemia is part of diabetic dyslipidemia and is associated with accelerated atherosclerosis. We investigated the effects of the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone on postprandial lipemia in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A randomized, 8-week, crossover, placebo-controlled, double-blind trial was performed in which rosiglitazone at 4 mg was administrated twice daily in 19 patients with type 2 diabetes. Standardized 6-h oral fat-loading tests were performed after each treatment period. Postprandial curves were calculated as the total area under the curve (AUC) and the incremental area under the curve (dAUC). RESULTS: Rosiglitazone did not change fasting plasma triglycerides compared with placebo (1.97 +/- 0.22 vs. 1.88 +/- 0.20 mmol/l, respectively) but decreased postprandial triglyceride levels, leading to significantly lower triglyceride dAUC (-37%, P < 0.05), without changing total triglyceride AUC. Significant postprandial triglyceride reductions in the chylomicron fraction (Svedberg flotation rate [Sf] >400) were achieved with rosiglitazone, which resulted in a significant lower triglyceride AUC (-22%) in this fraction. The postprandial triglyceride increase in VLDL1 (Sf 60-400) was also lower after rosiglitazone (-27%), but this did not result in a significant lower triglyceride AUC. In VLDL2 (Sf 20-60), there were no significant differences in triglyceride AUC and triglyceride dAUC between rosiglitazone and placebo. Rosiglitazone decreased free fatty acid (FFA) AUC (-12%) and FFA dAUC (-18%) compared with placebo. CONCLUSIONS: Rosiglitazone improves the metabolism of large triglyceride-rich lipoproteins and decreases postprandial FFA concentrations in type 2 diabetes. This may have clinical implications, as these effects may contribute to cardiovascular risk reduction.     

Changes in acetylcholine contractions induced by carnitine in coronary vessels isolated "in vitro"

As suggested by literature about the carnitine's choline-mimetic effects, it has been studied the influence of this substance on the response to Ach of the isolated coronary arteries. It has been seen that Ach has often induced the contraction of the preparation that was preceded or abolished by atropine or prifinium bromide, or reduced by fendiline and verapamil. It resulted also that carnitine has always increased the entity of the contraction of the preparation treated with Ach and that the raising was abolished by fendiline or verapamil. Taking such results and suggestions from the literature as a basis, it has been concluded that the carnitine increased the response of the preparation to Ach, sensitizing muscarinic receptors which cause the entry of Ca++ throught the cell membrane.