Effects of propofol on endothelial cells subjected to a peroxynitrite donor (SIN-1)

We investigated the effect of propofol on endothelial cells subjected to the peroxynitrite (ONOO-) donor 3-morpholino sydnonimine (SIN-1). Cells were incubated overnight with 0.5, 1.0 or 2.0 mM SIN-1, with or without 10-3 M propofol (Diprivan). Cytotoxicity, assessed by measuring the release of pre-incorporated 51Cr, increased when the concentration of SIN-1 increased, and was significantly decreased by 10-3 M propofol (90%, 78% and 28% of protection against 0.5, 1.0 and 2.0 mM SIN-1, respectively). Cell protection against 1 mM SIN-1 was tested with 0.03-1.0 mM propofol and this was compared to tyrosine, a target molecule for peroxynitrite. Propofol protected cells in a dose-dependent manner (r = 0.98; p < 0.001) and was as effective as tyrosine. Finally, using high-performance liquid chromatography, we demonstrated that propofol reacted with ONOO- more rapidly than did tyrosine, inhibiting nitrotyrosine formation. In the absence of propofol, 3.5 mM ONOO- with 1 mM tyrosine yielded 39.6% nitrotyrosine, but nitrotyrosine was not produced when 5 mM propofol was added. We conclude that propofol protects endothelial cells against the toxicity of ONOO-. The anti-oxidant properties of propofol can be partially attributed to its scavenging effect on peroxynitrite, a property that might be relevant in pathological situations involving a significant contribution of peroxynitrite to tissue damage.     

Cellular diversity of human placental stem villi: an ultrastructural and immunohistochemical study

The aim of the study was to investigate the distribution and differentiation of cell types in the stroma of human placental stem villi (SV). A total of 14 human term placental tissues were studied. Double immunolabeling was performed for desmin-vimentin, desmin--smooth actin and vimentin--smooth actin. Cytokeratin 7, proliferating cell nuclear antigen immunolabeling was also performed. Parallel tissue samples were examined by transmission electron microscopy. HSCORE was performed for the semi-quantitative analysis of distribution of cells in the stroma of SV. Vimentin-labeled cells were mostly distributed in the subtrophoblastic area. Desmin-vimentin double immunolabeling was mainly localized in the triangular area and to a lesser degree in the perivascular area and vessel walls (p=<0.001). However, desmin- smooth actin labeling was observed predominantly in the vessel wall and perivascular area. Vimentin- smooth actin immunoreactivity was significantly stronger in the triangular and perivascular areas compared to the vessel walls (p=0.003).

Ultrastructurally, cells in the stroma of SV were mesenchyme cells, reticulum cells, fibroblasts, myofibroblasts, smooth muscle cells, and Hofbauer cells, filamented and vacuolated cells. The differentiation of myofibroblasts in the triangular and perivascular areas may play a role in maturation of SV and villous contractility, modulation of the intervillous space and this may have effects on maternofetal placental circulation.     

The prevalence and characteristics of patients with classic locked-in syndrome in Dutch nursing homes

To establish the point prevalence and characteristics of patients with locked-in syndrome (LIS), particularly of the classic type, residing in Dutch nursing homes, a cross-sectional survey of Dutch nursing homes was conducted. The classic form of LIS was defined according to the criteria of the American Congress of Rehabilitation Medicine (1995). All Dutch long-term care organisations (n = 187) were asked if they had any patients with classic LIS as of December 5, 2011. The treating Elderly Care Physicians were then contacted to provide patient characteristics. Of all organisations, 91.4 % responded, and 11 organisations reported a total of 12 patients. After analysing the questionnaires, it was determined that ten patients had LIS, and two patients were characterised with vegetative state. Only two patients met the criteria for classic LIS, while six patients showed partial LIS. One of these patients was admitted to the nursing home after December 5, 2011, and was therefore, excluded. LIS without accompanying pontine lesion was observed in the remaining two patients. For the first time, the prevalence of classic LIS has been established at 0.7/10,000 somatic nursing home beds in all Dutch long-term care organisations. Possible explanations for this low prevalence could be the Dutch provision of home care or the influence of end-of-life decisions, such as euthanasia and withholding or withdrawing all medical treatment, including artificial nutrition and hydration. These alternate outcomes should be explored in further studies.     

Macular thickness after uneventful cataract surgery determined by optical coherence tomography

Background Using standardized macular optical coherence tomography (OCT) in the postoperative period, subclinical changes in macular thickness can be detected. With this method, postoperative development of macular thickness in healthy eyes is evaluated. The repeatability of the method and the influence of selected surgical (phaco time and phaco energy) and biometric parameters (axial length and anterior chamber depth) on the results were assessed. Methods In a prospective study, 33 patients without macular pathology in both eyes were examined. Phacoemulsification and intraocular lens (IOL) implantation was performed in one eye, and the contralateral eye served as control. OCT (StratusOCT; Zeiss, Dublin, CA, USA), mean minimal foveal thickness (MMFT) and mean foveal thickness (MFT) were measured preoperatively, at 1 day, 1 week and 6 weeks postoperatively. At these visits, the best-corrected visual acuity (BCVA) tests and slit-lamp examination were performed. To assess the influence on foveal thickness ocular axial length, anterior chamber depth, phacotime and energy were documented. Statistical analysis using parametric tests was carried out with standard statistical software (SPSS11, BIAS). Results MMFT of the operated eyes and the intraindividual difference of MMFT increased significantly at one day (+12.31 ± 24.2 μm, P < 0.001) and 6 weeks (+6.76 ± 22.6 μm, P = 0.009). MFT in the operated eyes and intraindividual difference of MFT rose significantly at 1 day, 1 week and 6 weeks (1 day: +10.66 ± 20.8 μm, P = 0,026; 1 week: +15.23 ± 19.7 μm; 6 weeks: +17.33 ± 14.81 μm, P < 0.001). Repeatability was better for MFT in controls (ICR = 0.92) than for MMFT in controls (ICR = 0.77). No clinical cystoid macular edema was diagnosed in this study. No correlation between macular thickening and visual acuity and selected surgical and biometrical parameters could be found. Conclusions After cataract surgery, a mild increase of foveal thickness without impact on visual acuity could be observed. This increase may be due to both subclinical changes and to influence of changes in media opacity on the measurement technique. Surgical and biometric parameters such as phacotime and energy and axial length did not correlate to the degree of macular thickening. Presented in part at the meeting of the European Society of Cataract and Refractive Surgeons (ESCRS), London, United Kingdom, September 2006 and at the meeting of the German Ophthalmological Society (DOG), Berlin, Germany, September 2006. The authors have no financial or proprietary interest in any material or method mentioned.     

Antimicrobial efficacy of semiconductor laser irradiation on implant surfaces

PURPOSE: This study was conducted to investigate the antimicrobial effect of an 809-nm semiconductor laser on common dental implant surfaces. MATERIALS AND METHODS: Sandblasted and acid-etched (SA), plasma-sprayed (TPS), and hydroxyapatite-coated (HA) titanium disks were incubated with a suspension of S. sanguinis (ATCC 10556) and subsequently irradiated with a gallium-aluminum-arsenide (GaAlAs) laser using a 600-microm optical fiber with a power output of 0.5 to 2.5 W, corresponding to power densities of 176.9 to 884.6 W/cm2. Bacterial reduction was calculated by counting colony-forming units on blood agar plates. Cell numbers were compared to untreated control samples and to samples treated with chlorhexidine digluconate (CHX). Heat development during irradiation of the implants placed in bone blocks was visualized by means of shortwave thermography. RESULTS: In TPS and SA specimens, laser irradiation led to a significant bacterial reduction at all power settings. In an energy-dependent manner, the number of viable bacteria was reduced by 45.0% to 99.4% in TPS specimens and 57.6% to 99.9% in SA specimens. On HA-coated disks, a significant bacterial kill was achieved at 2.0 W (98.2%) and 2.5 W (99.3%) only (t test, P < .05). For specimens treated with CHX, the bacterial counts were reduced by 99.99% in TPS and HA-coated samples and by 99.89% in SA samples. DISCUSSION: The results of the study indicate that the 809-nm semiconductor laser is capable of decontaminating implant surfaces. Surface characteristics determine the necessary power density to achieve a sufficient bactericidal effect. The bactericidal effect, however, was lower than that achieved by a 1-minute treatment with 0.2% CHX. The rapid heat generation during laser irradiation requires special consideration of thermal damage to adjacent tissues. CONCLUSION: No obvious advantage of semiconductor laser treatment over conventional methods of disinfection could be detected in vitro.     

Early improvement under mirtazapine and paroxetine predicts later stable response and remission with high sensitivity in patients with major depression

OBJECTIVE: Current clinical knowledge holds that antidepressants have a delayed onset of efficacy. However, the delayed onset hypothesis has been questioned recently by survival analytical approaches. We aimed to test whether early improvement under antidepressant treatment is a clinically useful predictor of later stable response and remission. METHOD: We analyzed data from a randomized double-blind controlled trial with mirtazapine and paroxetine in patients with major depression (DSM-IV). Improvement was defined as a 17-item Hamilton Rating Scale for Depression (HAM-D-17) score reduction of > or = 20%. Stable response was defined as > or = 50% HAM-D-17 score reduction at week 4 and week 6, and stable remission as a HAM-D-17 score of < or = 7 at week 4 and week 6. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. RESULTS: Improvement occurred in a majority of the analyzed patients within 2 weeks (mirtazapine: 72.7% of 109 patients; paroxetine: 64.9% of 103 patients). Early improvement was a highly sensitive predictor of later stable response or stable remission for both drugs. NPV approached maximum values as early as week 2 for mirtazapine and week 3 for paroxetine. After 2 weeks of treatment with mirtazapine and 3 weeks with paroxetine, almost none of the patients who had not yet improved became a stable responder or stable remitter in the later course. CONCLUSION: Our results strongly suggest that early improvement predicts later stable response with high sensitivity. These empirically derived data question the delayed onset hypothesis for both antidepressants tested and provide important clinical clues for an individually tailored antidepressant treatment.