Respiratory changes in subclavian vein diameters predicts fluid responsiveness in intensive care patients: a pilot study

The present pilot study investigated whether respiratory variation in subclavian vein (SCV) diameters correlates with fluid responsiveness in mechanically ventilated patients. Monocentric, prospective clinical study on fluid responsiveness in adult sedated, mechanically ventilated ICU patient, monitored with the PiCCO? system (Pulsion Medical System, Germany), and requiring a fluid challenge (FC). A 10-min fluid bolus of 500 mL of 0.9% saline was administered. Cardiac output (CO) and dynamic parameters [stroke volume variation (SVV) and pulse pressure variation (PPV)] measured by transpulmonary thermodilution and pulse contour analysis (PiCCO?) as well as classical hemodynamic parameters were recorded at baseline and after FC. Fluid responsiveness was described as an increase in CO of ≥?15%. Ultrasound measurements obtained in the subclavian long-axis view were used to calculate the SCV_variability index. A cut-off value for SCV variation for the prediction of fluid responsiveness was determined using receiver operating curve (ROC) analysis. Nine of 20 FCs (45%) induced an increase in CO of ≥?15%. At baseline, the SCV_variability index was greater in responders than in non-responders (34.0?±?21.4 vs. 9.0?±?5.5; p?=?0.0005). Diagnostic performance for the SCV_variability index revealed a cut-off value of 14 with a sensitivity of 100% [Confidence interval (CI) 95% (90; 100)] and a specificity of 82% [CI 95% (48; 98)] for the prediction of fluid responsiveness. Other parameters, such as SVV and PPV, could not predict fluid responsiveness. The correlation coefficient between CO variation and the SCV_variability index was 0.73 (p?<?0.001). The SCV_variability index was a reliable, non-invasive parameter for the prediction of fluid responsiveness at the bedside of mechanically ventilated, critically ill patients in this pilot study.     

Transplantation of human embryonic stem cell-derived oligodendrocyte progenitors into rat spinal cord injuries does not cause harm

Demyelination contributes to loss of function following spinal cord injury. We have shown previously that transplantation of human embryonic stem cell-derived oligodendrocyte progenitors into adult rat 200 kD contusive spinal cord injury sites enhances remyelination and promotes recovery of motor function. Previous studies using oligodendrocyte lineage cells have noted a correlation between the presence of demyelinating pathology and the survival and migration rate of the transplanted cells. The present study compared the survival and migration of human embryonic stem cell-derived oligodendrocyte progenitors injected 7 days after a 200 or 50 kD contusive spinal cord injury, as well as the locomotor outcome of transplantation. Our findings indicate that a 200 kD spinal cord injury induces extensive demyelination, whereas a 50 kD spinal cord injury induces no detectable demyelination. Cells transplanted into the 200 kD injury group survived, migrated, and resulted in robust remyelination, replicating our previous studies. In contrast, cells transplanted into the 50 kD injury group survived, exhibited limited migration, and failed to induce remyelination as demyelination in this injury group was absent. Animals that received a 50 kD injury displayed only a transient decline in locomotor function as a result of the injury. Importantly, human embryonic stem cell-derived oligodendrocyte progenitor transplants into the 50 kD injury group did not cause a further decline in locomotion. Our studies highlight the importance of a demyelinating pathology as a prerequisite for the function of transplanted myelinogenic cells. In addition, our results indicate that transplantation of human embryonic stem cell-derived oligodendrocyte progenitor cells into the injured spinal cord is not associated with a decline in locomotor function.     

Randomized controlled clinical trial of customized zirconia and titanium implant abutments for canine and posterior single-tooth implant reconstructions: preliminary results at 1 year of function

Objectives: The aim of this study was to test whether or not customized zirconia abutments exhibit the same survival rates in canine and posterior regions as titanium abutments, and to compare the esthetic result of the two abutment types. Material and methods: Twenty‐two patients with 40 implants in posterior regions were included and the implant sites were randomly assigned to 20 customized zirconia and 20 customized titanium abutments. All‐ceramic (AC) and metal–ceramic (MC) crowns were fabricated. In all except two cases, the crowns were cemented on the abutments using resin or glass‐ionomer cements. Two zirconia reconstructions were screw retained. At baseline, 6 and 12 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque (Pl) and bleeding on probing (BOP) were assessed and compared with natural control teeth. Furthermore, the difference of color (ΔE) of the peri‐implant mucosa and the gingiva of control teeth was evaluated by means of a spectrophotometer (Spectroshade). The data were analyzed with Student's unpaired t‐test, ANOVA and regression analyses. Results: Twenty patients with 19 zirconia and 12 titanium abutments were examined at a mean follow‐up of 12.6±2.7 months. The survival rate for reconstructions and abutments was 100%. No technical or biological problems were found at the test and control sites. Two chippings (16.7%) occurred at crowns supported by titanium abutments. No difference was found regarding PPD (meanPPD_ZrO2 3.4±0.7 mm, mPPD_Ti 3.3±0.6 mm), Pl (mPl_ZrO2 0.2±0.3, mPl_Ti 0.1±1.8) and BOP (mBOP_ZrO2 60±30%, mBOP_Ti 30±40%) between the two groups. Both crowns on zirconia and titanium abutments induced a similar amount of discoloration of the soft tissue compared with the gingiva at natural teeth (ΔE_ZrO2 8.1±3.9, ΔE_Ti 7.8±4.3). Conclusions: At 1 year, zirconia abutments exhibited the same survival and a similar esthetic outcome as titanium abutments.     

The impact of tumour volume and surgery on the outcome of adults with supratentorial WHO grade II astrocytomas and oligoastrocytomas

Summary Background. The study was performed to elucidate the impact of tumour volume and surgical resection on the long-term outcome of patients with supratentorial, diffuse, World Health Organization (WHO) grade II astrocytomas and oligo-astrocytomas.Method. After analysing 79 adult patients consecutively diagnosed between 1991 and 2000, we selected a group of 42 patients treated by surgery without adjuvant therapy. The tumour volume was defined as the whole region of T2-hyperintensity and measured interactively on pre- and postoperative and follow-up Magnetic Resonance Imaging (MRI) using a dedicated imaging software. Volumetric, clinical, and histological data were analysed for correlation with tumour progression (TP), malignant transformation (MT), drop in functional status (DKPS) and overall survival (OS).Findings. Pre- and postoperative tumour volumes, and the involvement of more than one lobe were strongly associated with worse outcome. Preoperative tumour volume was the strongest predictor of OS (p<0.01) and the only predictor of MT (p<0.05). The absolute and relative volumes of tumour removed by surgery were not significantly associated with outcome.Conclusions. Initial tumour volume, measured as the volume of T2-hyperintensity on MRI, and tumour extension are the strongest predictors of outcome in patients with supratentorial diffuse astrocytic WHO Grade II tumours. The potential benefit of aggressive tumour resection needs to be investigated in a prospective controlled trial.     

Transforming growth factor beta1 modulates cell migration in rat cortex: effects of ethanol

Transforming growth factor (TGF) beta1 regulates cell migration of non-neural cells. Hence, two hypotheses were tested: (i) that TGFbeta1 affects cell migration and the expression of associated adhesion proteins in developing cortex; and (ii) that these effects are antagonized by ethanol. The effects of TGFbeta1 (2.5-40 ng/ml) and ethanol (400 mg/dl) on cell migration were examined in organotypic cultures from fetal rat brains. Migration was determined by tracing the movement of cells pulse-labeled with bromodeoxyuridine. Cell migration was altered by TGFbeta1 in a concentration-dependent manner: at low concentrations, cell migration was promoted whereas at high concentrations TGFbeta1 impeded migration. Ethanol treatment alone reduced the rate of migration. Interestingly, the rate of cell migration in slices treated with both TGFbeta1 and ethanol was the same as that in untreated cultures. The expression of cell adhesion proteins (nCAM, integrin alpha3, alphav and beta1) was differentially effected by TGFbeta1 and/or ethanol. TGFbeta1 increased the expression of these adhesion proteins in a progressive, concentration-dependent manner. Likewise, ethanol also increased adhesion protein expression, however, combined TGFbeta1 and ethanol treatment reduced expression. Collectively, the data show that TGFbeta1 alters cell migration in the developing cortex and that the TGFbeta1 system is a target of ethanol toxicity.     

Receptor dysfunctions in human disease

Summary The characterization of binding parameters of hormones and drugs to specific receptors at various human cell types have introduced an interesting approach for the evaluation of pathogenic mechanisms involved in endocrine and metabolic disorders. The dysregulation of cellular receptors in those disease include changes in receptor number, changes in binding affinity and production of antibodies against receptor molecules. It can be concluded from these observations that altered receptor physiology may be of important value for abnormalities in cellular recognition and control mechanisms which can be observed in neoplastic, inflammatory, immune and developmental diseases.