[Epidural anesthesia for fetoscopy : Retrospective analysis of a one-year cohort]. / Peridurale Anästhesie zur Fetoskopie : Retrospektive Analyse einer Einjahreskohorte.

BACKGROUND: The introduction of routine prenatal screening using ultrasound has led to a substantial increase in diagnoses of fetal disorders that are amenable to intrauterine treatment. While an ultrasound guided insertion of small bore cannulas can be performed under local anesthesia, insertion of a fetoscope usually requires anesthetic management for the mother and the fetus. Additionally, the fetus' intrauterine position may have to be manipulated in order to enable access. Such manoeuvres depend on relaxation of the mother's abdominal wall. General anesthesia has been the preferred method, but it involves substantial risks both to the mother and possibly the fetus, especially when combined with aggressive uterine relaxation. Epidural anesthesia (EA) may provide an alternative. Only little systematic data on the efficacy, requirements or untoward effects of epidural anesthesia for fetoscopy exists in the literature, yet a high rate of arterial hypotension following EA has been reported. We therefore aimed to assess the hemodynamic reaction to EA in a mixed population of pregnant women undergoing fetoscopy for a variety of fetal conditions and performed a retrospective analysis of a one-year cohort in a single university hospital. METHODS: The local ethics committee approved this retrospective analysis and waived patient consent (local study identifier 304/14). We extracted anesthesiologic and hemodynamic data from the anesthesia charts of 23 consecutive cases of elective fetoscopic procedures requiring anesthesia between May 2011 and 2012 at a German university medical centre. RESULTS: Twenty-three cases of fetoscopy were included in this study. Indications for fetoscopy were congenital diaphragmatic hernia (n = 9), aortic valve stenosis (n = 8), and feto-fetal transfusion syndrome (n = 6). Median gestational age was 26 (8, interquartile range) weeks. Lumbar epidural catheters were injected with a median dose of 0.09 (0.02, interquartile range) ml ropivacaine 0.75% per cm maternal height. In 11 patients, EA was titrated to a sufficient height whereas 12 patients received a single dose with a median volume of 0.08 (0.02) ml/cm maternal height. After injection, systolic arterial pressure did not change significantly, mean arterial pressure dropped from 93 (14) mm Hg to 88 (15) mm Hg (p = 0.03). Heart rate fell from 96 (29) to 89 (20) beats per minute (p = 0.02). At incision, neither blood pressure nor heart rate changed significantly. For hemodynamic support during the procedure, cafedrine/theodrenaline (Akrinor™) was injected in five patients (median dose in these patients 0.5 (1.5) ml). One patient carrying a fetus with a poor prognosis and who underwent two separate procedures demanded additional sedation, for which we chose remifentanil. Another patient was hypotensive after intravenous administration of the tocolytic drug atosiban. A stable hemodynamic condition was quickly restored in this patient with administration of cafedrine/theodrenaline and i. v. fluids. All procedures were performed without conversion to general anaesthesia. CONCLUSION: This retrospective study demonstrates that fetoscopic procedures under EA in the range of indications treated in our institution can be performed safely. EA was associated with stable hemodynamic conditions in this mixed cohort of pregnant women. EA appears thus to be a suitable technique for fetoscopy, avoiding the risks inherent to general anesthesia in pregnant women.

[Visualization of the superior vena cava in the supraclavicular acoustic window]. / Darstellbarkeit der Vena cava superior im rechten supraklavikulären Schallfenster.

BACKGROUND: The ultrasound-guided venipuncture of the internal jugular vein for placement of a central venous catheter is well established. For verification of the catheter tip position mostly intracardiac ECG or chest radiography are used. Previously, we established the right supraclavicular fossa view for ultrasound based verification of the catheter placement in the superior vena cava utilizing a microconvex probe. The microconvex probe has a small footprint. However, not all ultrasound systems used in the operating theater are equipped with a microconvex transducer. AIM: Thus, we systematically compared the visibility of intrathoracic vessels obtained by a linear and a microconvex prone via the right supraclavicular view. MATERIAL AND METHODS: We assessed the visibility of the junction of the brachiocephalic veins, the superior vena cava, the right pulmonary artery, the ascending aorta and the internal jugular vein, comparing a linear with a microconvex probe when using the right supraclavicular view in healthy volunteers. The superior vena cava also was identified using Doppler ultrasound. RESULTS: With the microconvex probe the superior vena cava was visible in all 30 healthy volunteers, but with a linear transducer it was visible in only 53 %. The combined view of the superior vena cava and the right pulmonary artery was possible in all cases when using the microconvex probe, but in only 38 % when using the linear probe. The junction of the brachiocephalic veins was seen in 75 % of the volunteers with the microconvex probe and in 38 % with the linear one. The aorta was visible in 87 % of cases with the microconvex transducer, but only in 30 % with the linear probe. The internal jugular vein was always visible with either probe. CONCLUSION: The microconvex transducer as compared to the linear probe is superior in visualizing the superior vena cava. Possible reasons are a smaller footprint, a better degree of freedom for angulation and a greater penetration depth of the microconvex probe.

[Traumatic tricuspid valve insufficiency with right-to-left shunt: bridging using extracorporeal venovenous membrane oxygenation]. / Traumatische Trikuspidalklappeninsuffizienz mit Rechts-links-Shunt: "Bridging" mithilfe der extrakorporalen venovenösen Membranoxygenierung.

The case of a young male motor vehicle driver is reported who suffered multiple trauma in a car accident with pulmonary and cardiac contusions. In the course of severe pneumonia and traumatic tricuspid valve insufficiency a right-to-left shunt with refractory hypoxemia developed across a pre-existing atrial septal defect (ASD). The patient could be successfully treated by the combination of extracorporeal membrane oxygenation for bridging, interventional ASD occlusion and in the long-term by operative reconstruction of the tricuspid valve.

A single exposure to hyperbaric oxygen increases levels of circulating nucleosomes but does not induce mononuclear cell apoptosis in divers.

Recent reports that hyperbaric oxygenation (HBO2) induced apoptosis in T-cell lines raised concern about a possible immunosuppressive effect of HBO2. Nucleosomes, DNA fragments wrapped around a histone core, have been observed in the circulation in diseases with increased cell death such as sepsis. Our aim was to investigate, whether HBO2 increases circulating nucleosomes as a marker of cell death and induces apoptosis of peripheral blood mononuclear cells in vivo. After informed consent 29 healthy volunteers were exposed to a 30 minute dive at 2.8 atmospheres absolute in a pressure chamber under resting conditions, while breathing 100% oxygen. Samples were obtained before and 24 hours after exposure. Circulating nucleosomes were measured in serum. Caspase-3 activation, Bcl-2 expression and mRNA of Bcl-2, Bcl-xl and Bax were analyzed in mononuclear cell extracts. Nucleosomes were elevated markedly 24h after exposure (p<0.01), while caspase-3 was not activated significantly. mRNA levels of Bcl-2, Bcl-xl and Bax were not altered. In conclusion, while evidence of elevated levels of circulating nucleosomes was found, mononuclear cell apoptosis was not affected by a single exposure to hyperbaric oxygen.

[Apoptosis as a pathomechanism in sepsis]. / Apoptose als Pathomechanismus in der Sepsis.

Sepsis is still a leading cause of death in many intensive care patients. The pathophysiology of the disease is dominated by complex immune cascades. Recent research demonstrates that immune cells respond to sepsis with an increased rate of programmed cell death. Up-regulated apoptosis of leukocytes was observed in animal models of sepsis as well as in patients suffering from severe sepsis. The mitochondrial protein Bcl-2 and the caspase cascade play an important role in the regulation of apoptosis. Overexpression of Bcl-2 or inhibition of caspases resulted in an increased survival in animal models of sepsis. Recent reports indicate the relevance of apoptosis in patients with severe sepsis. These results may spawn novel immunomodulatory strategies in the treatment of sepsis.

Induction of glutathione synthesis in human keratinocytes by Ginkgo biloba extract (EGb761).

The objective of the present study was to characterize the action of Ginkgo biloba extract (EGb761) and its sub-fractions on glutathione homeostasis in a human keratinocyte cell culture model. Cells were incubated with EGb761, its purified flavonoid (quercetin, kaempferol, rutin) or terpenoids (gingkolides A, B, C, J, bilobalide) constituents or the vehicle for up to 72 hours. Incubation of keratinocytes with the purified flavonoids or terpenoids did not affect cellular GSH levels. However, EGb761 treatment (up to 200 microg/ml) resulted in a dose-dependent increase of cellular GSH. Western blot analysis of extracts from cells treated with EGb761 revealed increased levels of the catalytic subunit of gamma-glutamylcysteinyl synthetase (gamma-GCS), the rate-limiting enzyme in GSH synthesis. The abundance of mRNA for the catalytic subunit (assayed by RT-PCR) was also increased by the treatment with EGb761. Increased levels of cellular GSH by EGb761 were also observed in other cell lines including those from human bladder and liver as well as in murine macrophages indicating that the induction of gamma-GCS mRNA, protein and GSH may be an ubiquitous effect of EGb761 in mammalian cells.

Effect of benzoyl peroxide on antioxidant status, NF-kappaB activity and interleukin-1alpha gene expression in human keratinocytes.

Benzoyl peroxide (BP) is used as a topical treatment for acne. Besides its anti-bacterial activity, the exact molecular mechanisms underlying its mode of action are not fully understood. In the current study, the effects of BP on cell viability, antioxidant status and, IL-1 and IL-8 gene expression were investigated in HaCaT keratinocytes. Keratinocytes incubated for 24 h with BP exhibited a dose-dependent cytotoxicity at concentrations above 250 microM. Furthermore, in the presence of 300 microM BP about 50% of the cellular vitamin E was depleted within the first 30 min. The intracellular ratio of oxidized to reduced glutathione (GSSG/GSH) was increased significantly starting 6 h after BP treatments indicating that BP reacts rapidly with targets in the cell membrane and more slowly with those in the cytosol. NF-kappaB transactivation was not significantly affected by BP. However, BP treatment of HaCaT keratinocytes resulted in a dose-dependent increase in IL-1alpha gene expression whereas no changes in IL-8 mRNA levels were observed. These results demonstrate that BP induces an inflammatory reaction mediated by oxidative stress by a pathway independent of the redox-sensitive transcription factor NF-kappaB.

Effect of selenium and vitamin E deficiency on differential gene expression in rat liver.

To examine the molecular events associated with selenium (Se) and vitamin E (VE) deficiency, we applied cDNA array technology to define the transcriptional response in the liver of Se- and VE-deficient rats. VE deficiency alone did not induce any significant changes in expression profile among the genes evaluated. Se deficiency lead to a down-regulation of Se-dependent cGPx and to an induction of genes, encoding for detoxifying enzymes in liver (cytochrome P450 4B1, UDP-glucuronosyltransferase 1). Combined VE and Se deficiency was characterized by alterations in the expression level of genes encoding for proteins involved in inflammation (multispecific organic anion exporter, SPI-3 serine protease inhibitor) and acute phase response (alpha-1 acid glycoprotein, metallothionein 1). Additionally, a significant down-regulation in the expression level of genes important in the inhibition of apoptosis (defender against cell death 1 protein, Bcl2-L1), cell cycle (G1/S-specific cyclin D1) and antioxidant defense (gamma-glutamylcysteine synthetase catalytic subunit) was demonstrated. The experimental strategy identified several novel Se and VE sensitive genes.

Molecular aspects of alpha-tocotrienol antioxidant action and cell signalling.

Vitamin E, the most important lipid-soluble antioxidant, was discovered at the University of California at Berkeley in 1922 in the laboratory of Herbert M. Evans (Science 1922, 55: 650). At least eight vitamin E isoforms with biological activity have been isolated from plant sources. Since its discovery, mainly antioxidant and recently also cell signaling aspects of tocopherols and tocotrienols have been studied. Tocopherols and tocotrienols are part of an interlinking set of antioxidant cycles, which has been termed the antioxidant network. Although the antioxidant activity of tocotrienols is higher than that of tocopherols, tocotrienols have a lower bioavailability after oral ingestion. Tocotrienols penetrate rapidly through skin and efficiently combat oxidative stress induced by UV or ozone. Tocotrienols have beneficial effects in cardiovascular diseases both by inhibiting LDL oxidation and by down-regulating 3-hydroxyl-3-methylglutaryl-coenzyme A (HMG CoA) reductase, a key enzyme of the mevalonate pathway. Important novel antiproliferative and neuroprotective effects of tocotrienols, which may be independent of their antioxidant activity, have also been described.

Ozone potentiates vitamin E depletion by ultraviolet radiation in the murine stratum corneum.

As the outermost layer of the skin, the stratum corneum is exposed to environmental oxidants. To investigate putative synergisms of environmental oxidative stressors in stratum corneum, hairless mice were exposed to ultraviolet radiation (UV) and ozone (O(3)) alone and in combination. Whereas a significant depletion of alpha-tocopherol was observed after individual exposure to either a 0.5 minimal erythemal dose of UV or 1 ppm O(3) for 2 h, the combination did not increase the effect of UV alone. However, a dose of 0.5 ppm O(3) x 2 h, which had no effect when used alone, significantly enhanced the UV-induced depletion of vitamin E. We conclude that concomitant exposure to low doses of UV and O(3) at levels near those that humans can be exposed to causes additive oxidative stress in the stratum corneum.

Cadmium tolerance and accumulation in Indian mustard is enhanced by overexpressing gamma-glutamylcysteine synthetase.

To investigate rate-limiting factors for glutathione and phytochelatin (PC) production and the importance of these compounds for heavy metal tolerance, Indian mustard (Brassica juncea) was genetically engineered to overexpress the Escherichia coli gshI gene encoding gamma-glutamylcysteine synthetase (gamma-ECS), targeted to the plastids. The gamma-ECS transgenic seedlings showed increased tolerance to Cd and had higher concentrations of PCs, gamma-GluCys, glutathione, and total non-protein thiols compared with wild-type (WT) seedlings. When tested in a hydroponic system, gamma-ECS mature plants accumulated more Cd than WT plants: shoot Cd concentrations were 40% to 90% higher. In spite of their higher tissue Cd concentration, the gamma-ECS plants grew better in the presence of Cd than WT. We conclude that overexpression of gamma-ECS increases biosynthesis of glutathione and PCs, which in turn enhances Cd tolerance and accumulation. Thus, overexpression of gamma-ECS appears to be a promising strategy for the production of plants with superior heavy metal phytoremediation capacity.

Sebaceous gland secretion is a major physiologic route of vitamin E delivery to skin.

Skin plays an important part in the protection against oxidative stressors, such as ultraviolet radiation, ozone, and chemicals. This study was based on the observation that upper facial stratum corneum contained significantly higher levels of the antioxidant alpha-tocopherol than corresponding layers of arm stratum corneum. We hypothesized that the underlying mechanism involves sebaceous gland secretion of vitamin E. To test this, we examined in eight human volunteers: (i) stratum corneum levels and distribution profiles of vitamin E in sites with a different sebaceous gland density (arm versus cheek); (ii) whether vitamin E is a significant constituent of human sebum; and (iii) if there is a correlation between levels of vitamin E and squalene, a marker of sebum secretion, in skin surface lipids. Using standardized techniques for stratum corneum tape stripping and sebum collection, followed by high-performance liquid chromatography analysis of tocopherols and squalene, we found that: (i) the ratio of cheek versus upper arm alpha-tocopherol levels was 20 : 1 for the upper stratum corneum and decreased gradually with stratum corneum depth; (ii) vitamin E (alpha- and gamma-tocopherol forms) is a significant constituent of human sebum and is continuously secreted at cheek and forehead sites during a test period of 135 min; and (iii) vitamin E correlates well with levels of cosecreted squalene (r2 = 0.86, p < 0.001). In conclusion, sebaceous gland secretion is a relevant physiologic pathway for the delivery of vitamin E to upper layers of facial skin. This mechanism may serve to protect skin surface lipids and the upper stratum corneum from harmful oxidation.

Vitamin C, uric acid, and glutathione gradients in murine stratum corneum and their susceptibility to ozone exposure.

The stratum corneum has been recognized as the main cutaneous oxidation target of atmospheric ozone (O3), a major part of photochemical smog. This study reports the presence and distribution of vitamin C, glutathione, and uric acid in murine stratum corneum, and evaluates their susceptibility to acute environmental exposure to O3. Based on tape stripping and a modified extraction method with high performance liquid chromatography electrochemical analysis, we detected vitamin C (208.0 +/- 82.5 pmol per 10 consecutive pooled tapes), glutathione (283.7 +/-96.3), and uric acid (286.4 +/-47.1) in murine stratum corneum as compared with only 16.5 +/- 1.4 pmol alpha-tocopherol. Vitamin C, glutathione (both p < 00.001), and urate (p < 0.01) were found to exhibit a gradient with the lowest concentrations in the outer layers and a steep increase in the deeper layers. To investigate the effect of O3 exposure on hydrophilic antioxidants, we exposed SKH-1 hairless mice to O3 concentrations of 0, 0.8, 1, and 10 p.p.m., and stratum corneum was analyzed before and after exposure. Whereas mock exposure with 0 p.p. m. for 2 h had no significant effect, O3 doses of 1 p.p.m. for 2 h and above showed depletion of all three antioxidants. Vitamin C was decreased to 80% +/- 15% of its pretreatment content (p < 0.05), GSH to 41% +/- 24% (p < 0.01), and uric acid to 44% +/- 28% (p < 0.01). This report demonstrates the previously unrecognized role of hydrophilic antioxidants in the stratum corneum and provides further evidence that O3 induces oxidative stress in this outer skin layer.