Ultrasound-guided caudal blockade and sedation for paediatric surgery: a retrospective cohort study

Data on safety and success rates of ultrasound‐guided caudal blockade, performed on sedated children with an uninstrumented airway, are scarce. We performed a retrospective observational study of validated data from April 2014 to December 2020 in a paediatric cohort where the initial plan for anaesthetic management was sedation and caudal epidural without general anaesthesia or airway instrumentation. We examined success rates of this approach and rates of block failure and block‐related complications. In total, 2547 patients ≤ 15 years of chronological age met inclusion criteria. Among the 2547 cases, including 453 (17.8%) former preterm patients, caudal‐plus‐sedation success rate was 95.1%. The primary anaesthesia plan was abandoned for general anaesthesia in 124 cases. Pain‐related block failure in 83 (3.2%) was the most common cause for conversion. Complications included 39 respiratory events and 9 accidental spinal anaesthetics. Higher odds of pain‐related block failure were associated with higher body weight (adjusted OR 1.063, 95%CI 1.035–1.092, p < 0.001) as well as with mid‐abdominal surgery (e.g. umbilical hernia repair) (adjusted OR 15.11, 95%CI 7.69–29.7, p < 0.001), whereas extreme (< 28 weeks) former prematurity, regardless of chronological age, was associated with higher odds (adjusted OR 3.62, 95%CI 1.38–9.5, p = 0.009) for respiratory problems. Ultrasound‐guided caudal epidural, performed under sedation with an uninstrumented airway, is an effective technique in the daily clinical routine. Higher body weight and mid‐abdominal surgical procedures are risk factors for pain‐related block failure. Patients who, regardless of chronological age, had been born as extreme preterm babies are at the highest risk for respiratory events.

Indium-mediated allylation of disaccharides

The indium-mediated allylation followed by ozonolysis has been applied for the elongation of different disaccharides such as cellobiose, lactose and maltose. This reaction sequence and per-O-acetylation produced the expected mixture of α/β-pyranoid as well as α/β-furanoid isomers. The main product in all cases adopted the β-pyranose form and could be isolated and fully characterized with the help of NMR-spin simulations. Thorough investigation of the side products throughout optimization of the conditions for the ozonolysis resulted in the discovery of a novel 12 membered bridged disaccharide.

Indium-mediated C-allylation of melibiose

The indium-mediated allylation reaction has been applied to melibiose, a disaccharidic substrate. This elongation methodology allows for a short, efficient and diastereoselective approach towards complex glycosylated carbohydrate structures. The stereochemical outcome of the key intermediates, allylated disaccharides, has been determined by X-ray analysis. Ozonolysis of the introduced double bond yielded the unprotected elongated disaccharides in the equilibrium of the pyranoid as well as furanoid isomers in both anomeric forms, respectively. Per-O-acetylation has been performed to facilitate separation of the isomeric mixture for structural identification. The main product revealed to adopt a β-pyranoid form of the elongated unit at the reducing end of the disaccharide.

Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

BACKGROUND

The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs).

METHODS

LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as 'night-time' when induction was between 8:00 PM and 7:59 AM.

RESULTS

Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P=0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P=0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P=0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09-1.90; P=0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89-1.90; P=0.15).

CONCLUSIONS

Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events.

CLINICAL TRIAL REGISTRATION

NCT01601223.

A versatile de novo synthesis of legionaminic acid and 4-epi-legionaminic acid starting from d-serine

Legionaminic acid and 4-epi-legionaminic acid are 5,7-diacetamido nonulosonic acids and are assumed to play a crucial role in the virulence of Legionella pneumophila, the causative agent of Legionnaires' disease. Moreover, they are ideal target motifs for the development of vaccines and pathogen detection. Herein, we present a versatile de novo synthesis of legionaminic acid and 4-epi-legionaminic acid. Starting from simple d-serine, the C₉-backbone is built up by two CC-bond formation reactions. First, the protected d-serine motif is elongated utilizing a highly stereoselective nitroaldol reaction to give a C₆-precursor of desired d-rhamno configuration. Second, an indium-mediated allylation is employed to further elongate the carbon backbone and introduce a masked α-keto acid function.

A stereoselective and flexible synthesis to access both enantiomers of N-acetylgalactosamine and peracetylated N-acetylidosamine

Synthetic approaches towards N-acetylgalactosamine (GalNAc) have been attracting considerable interest since this compound is known for its pivotal role in cell–cell interaction and receptor induced cell signaling. Herein, we present a synthetic route in which two of the four stereogenic centers present in the target compound are derived from enantiopure tartaric acid being selectively converted to epoxy alcohols. The key step is the Pd-catalyzed, stereo- and regioselective epoxide opening and subsequent nucleophilic substitution of an azide functionality. This approach enables the synthesis of the naturally D- and unnaturally L-configured GalNAc, as well as both enantiomers of the largely unknown N-acetylidosamine (IdoNAc).

Patient's and health care provider's perspectives on music therapy in palliative care - an integrative review

Background

The use of music as therapy in multidisciplinary end-of-life care dates back to the 1970s and nowadays music therapy (MT) is one of the most frequently used complementary therapy in in-patient palliative care in the US. However existing research investigated music therapy’s potential impact mainly from one perspective, referring to either a quantitative or qualitative paradigm. The aim of this review is to provide an overview of the users’ and providers’ perspectives on music therapy in palliative care within one research article.

Methods

A systematic literature search was conducted using several databases supplemented with a hand-search of journals between November 1978 and December 2016. Inclusion criteria were: Music therapy with adults in palliative care conducted by a certified music therapist. Both quantitative and qualitative studies in English, German or a Scandinavian language published in peer reviewed journals were included. We aimed to identify and discuss the perspectives of both patients and health care providers on music therapy’s impact in palliative care to forward a comprehensive understanding of it’s effectiveness, benefits and limitations. We investigated themes mentioned by patients within qualitative studies, as well as commonly chosen outcome measures in quantitative research. A qualitative approach utilizing inductive content analysis was carried out to analyze and categorize the data.

Results

Twelve articles, reporting on nine quantitative and three qualitative research studies were included. Seven out of the nine quantitative studies investigated pain as an outcome. All of the included quantitative studies reported positive effects of the music therapy. Patients themselves associated MT with the expression of positive as well as challenging emotions and increased well-being. An overarching theme in both types of research is a psycho-physiological change through music therapy.

Conclusions

Both quantitative as well as qualitative research showed positive changes in psycho-physiological well-being. The integration of the users´ and providers´ perspectives within future research applicable for example in mixed-methods designs is recommended.

An observational study of the macro- and micro-haemodynamic implications of epidural anaesthesia in children

The haemodynamic implications of epidural anaesthesia in children are poorly documented. We report macro- and micro-haemodynamic data from an observational study of 25 children ranging from neonates to six-years old, who underwent surgery conducted with a specific combination of monitoring systems. We analysed 90 min of study-related monitoring after epidural catheterisation, with skin incision taking place after around 30 min. We recorded macrohaemodynamic parameters (monitored using LiDCOrapid) including heart rate, mean arterial pressure, cardiac output, stroke volume, systemic vascular resistance and stroke volume variation. Microhaemodynamic parameters (monitored using Invos™) included cerebral and peri-renal oxygenation. Based on the entire 90 min of study-related monitoring, we found significant increases in cardiac output (p = 0.009), stroke volume (p = 0.006) and stroke volume variation (p = 0.008), as well as decreases in systemic vascular resistance (p = 0.007) around 30 min after epidural blockade. There were no significant changes in heart rate, arterial pressure and cerebral or peri-renal oxygenation during these 90 min. Considering that the microhaemodynamic parameters were not affected by the macrohaemodynamic changes, we conclude that autoregulation of the brain and the kidneys was maintained in children under epidural anaesthesia.

Delaying surgery to perform CT scans for suspected appendicitis decreases the rate of negative appendectomies without increasing the rate of perforation nor postoperative complications

PURPOSE

Negative appendectomies are costly and are embedded with unnecessary risks for the patients. A careful indication for surgery seems mandatory even more so, since conservative therapy emerges as a potential alternative to surgery. The aims of this population-based study were to analyze whether radiological examinations for suspected appendicitis decreased the rate of negative appendectomies without increasing the rate of perforation or worsening postoperative outcomes.

METHOD

This study is a retrospective analysis of a prospective population-based database. The data collection included preoperative investigations and intraoperative and postoperative outcomes.

RESULTS

Based on 2559 patients, the rate of negative appendectomies decreased significantly with the use of CT scan as compared to clinical evaluation only (9.3 vs 5 %, p = 0.019), whereas ultrasonography alone was not able to decrease this rate (9.3 vs 6.2 %, p = 0.074). Delaying surgery for radiological investigation did not increase the rate of perforation (18.1 vs 19.2 %; adjusted odds ratio (OR) 1.01; 0.8-1.3; p = 0.899). Postoperative complications (surgical reintervention, postoperative wound infection, postoperative hematoma, postoperative intra-abdominal abscess, postoperative ileus) were all comparable.

CONCLUSION

In this population-based study, CT scan was the only radiological modality that significantly reduced the rate of negative appendectomy. The delay induced by such additional imaging did not increase perforation nor complication rates. Abdominal CT scans for suspected appendicitis should therefore be more frequently used if clinical findings are unconclusive.

Novel approaches in selective tryptophan isotope labeling by using Escherichia coli overexpression media

NMR-based investigations of large protein complexes require optimized isotopic labeling schemes. We report new methods to introduce stable isotopes into tryptophan residues; these are fine-tuned to the requirements of the particular protein NMR experiment. Selective backbone labeling was performed by using a new α-ketoacid precursor as an additive in cell-based overexpression media. Additionally, we developed synthetic routes to certain isotopologues of indole with (13)C-(1)H spin systems surrounded by (12)C and (2)H. The corresponding proteins, overexpressed in the presence of these precursor compounds, can be effectively analyzed for conformational changes in tryptophan residues in response to external stimuli, such as interaction with other proteins or small molecules.

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

Higher aminosugars are interesting targets in carbohydrate synthesis since these compounds play important roles in biological systems. However, their availability from natural sources is limited. Thus, in order to investigate their biological function, the development of facile and adaptable routes to this class of compounds is of fundamental importance. Our synthetic route towards these target molecules makes use of readily accessible pentoses and hexoses, which are subjected to indium-mediated two-carbon chain elongation. Subsequent ozonolysis and treatment with base yields α,β-unsaturated aldehydes, which are stereoselectively epoxidized using Jørgenson’s protocol. After Wittig chain elongation the obtained allylic epoxides were regio- and stereoselectively opened with trimethylsilyl azide under palladium catalysis. Finally, a suitable deprotection protocol, starting with acidic acetate cleavage and ozonolysis was established. Peracetylation of the products simplifies purification and subsequent azide reduction followed by final deacetylation using methanolic sodium methoxide furnishes the title compounds.

α-Ketoacids as precursors for phenylalanine and tyrosine labelling in cell-based protein overexpression

(13)C-α-ketoacid metabolic precursors of phenylalanine and tyrosine effectively enter the metabolism of a protein overexpressing E. coli strain to label Phe- and Tyr-residues devoid of any cross-labelling. The methodology gives access to highly selective labelling patterns as valuable tools in protein NMR spectroscopy without the need of (15)N-chiral amino acid synthesis using organic chemistry.

α-Ketoacids as precursors for phenylalanine and tyrosine labelling in cell-based protein overexpression

(13)C-α-ketoacid metabolic precursors of phenylalanine and tyrosine effectively enter the metabolism of a protein overexpressing E. coli strain to label Phe- and Tyr-residues devoid of any cross-labelling. The methodology gives access to highly selective labelling patterns as valuable tools in protein NMR spectroscopy without the need of (15)N-chiral amino acid synthesis using organic chemistry.

Selective isotope labelling of leucine residues by using α-ketoacid precursor compounds

You can have one without the other: A new metabolic precursor compound can selectively introduce (13)C and (2)H patterns at leucine residues in proteins in cell-based expression systems without interfering with valine metabolism. The protocol provides selectively labelled macromolecules well suited for probing structure and dynamics in high-molecular-weight proteins by NMR spectroscopy.

Clinical ex vivo lung perfusion--pushing the limits

Ex vivo lung perfusion (EVLP) provides the ability to evaluate donor lungs before transplantation. Yet, limited prospective clinical data exist with regard to its potential to recondition unacceptable donor lungs. This paper summarizes the results of a prospective study of lung transplantation using only initially unacceptable donor lungs, which were improved by EVLP for 2-4 h. From March 2010-June 2011, 13 lungs were evaluated ex vivo. Median donor PaO(2) at FiO(2) 1.0/PEEP5 was 216 mmHg (range 133-271). Four lungs, all with trauma history, showed no improvement and were discarded. Nine lungs improved to a ΔPO(2) higher than 350 mmHg. Median PvO(2) at final assessment in these lungs was 466 mmHg (range 434-525). These lungs were transplanted with a median total ischemic time of 577 min (range 486-678). None of the patients developed primary graft dysfunction grades 2 or 3 within 72 h after transplantation. One patient with secondary pulmonary hypertension was left on a planned prolonged extracorporeal membrane oxygenation postoperatively. Median intubation time was 2 days. Thirty-day mortality was 0%. During the observation period, 119 patients received standard lung transplantation with comparable perioperative outcome. EVLP has a significant potential to improve the quality of otherwise unacceptable donor lungs.

Synthesis of fluorinated maltose derivatives for monitoring protein interaction by (19)F NMR

A novel reporter system, which is applicable to the ¹⁹F NMR investigation of protein interactions, is presented. This approach uses 2-F-labeled maltose as a spy ligand to indirectly probe protein–ligand or protein–protein interactions of proteins fused or tagged to the maltose-binding protein (MBP). The key feature is the simultaneous NMR observation of both ¹⁹F NMR signals of gluco/manno-type-2-F-maltose-isomers; one isomer (α-gluco-type) binds to MBP and senses the protein interaction, and the nonbinding isomers (β-gluco- and/or α/β-manno-type) are utilized as internal references. Moreover, this reporter system was used for relative affinity studies of fluorinated and nonfluorinated carbohydrates to the maltose-binding protein, which were found to be in perfect agreement with published X-ray data. The results of the NMR competition experiments together with the established correlation between ¹⁹F chemical shift data and molecular interaction patterns, suggest valuable applications for studies of protein–ligand interaction interfaces.

Gram scale synthesis of 3-fluoro-1-hydroxyacetone phosphate: a novel donor substrate in rabbit muscle aldolase-catalyzed aldol reactions

An efficient gram scale synthesis of 3-fluoro-1-hydroxyacetone phosphate (FHAP) has been developed. As a close analog to dihydroxyacetone phosphate, FHAP was used as a novel donor substrate for rabbit muscle aldolase catalyzed reactions. The different binding affinities of the gem-diol and keto form of FHAP were studied by (19)F-NMR.

Diclofenac hypersensitivity: antibody responses to the parent drug and relevant metabolites

Background

Hypersensitivity reactions against nonsteroidal antiinflammatory drugs (NSAIDs) like diclofenac (DF) can manifest as Type I-like allergic reactions including systemic anaphylaxis. However, except for isolated case studies experimental evidence for an IgE-mediated pathomechanism of DF hypersensitivity is lacking. In this study we aimed to investigate the possible involvement of drug- and/or metabolite-specific antibodies in selective DF hypersensitivity.

Methodology/Principal Findings

DF, an organochemically synthesized linkage variant, and five major Phase I metabolites were covalently coupled to carrier proteins. Drug conjugates were analyzed for coupling degree and capacity to crosslink receptor-bound IgE antibodies from drug-sensitized mice. With these conjugates, the presence of hapten-specific IgE antibodies was investigated in patients' samples by ELISA, mediator release assay, and basophil activation test. Production of sulfidoleukotrienes by drug conjugates was determined in PBMCs from DF-hypersensitive patients. All conjugates were shown to carry more than two haptens per carrier molecule. Immunization of mice with drug conjugates induced drug-specific IgE antibodies capable of triggering mediator release. Therefore, the conjugates are suitable tools for detection of drug-specific antibodies and for determination of their anaphylactic activity. Fifty-nine patients were enrolled and categorized as hypersensitive either selectively to DF or to multiple NSAIDs. In none of the patients' samples evidence for drug/metabolite-specific IgE in serum or bound to allergic effector cells was found. In contrast, a small group of patients (8/59, 14%) displayed drug/metabolite-specific IgG.

Conclusions/Significance

We found no evidence for an IgE-mediated effector mechanism based on haptenation of protein carriers in DF-hypersensitive patients. Furthermore, a potential involvement of the most relevant metabolites in DF hypersensitivity reactions could be excluded.

Simulation and analysis of conjunctive use with MODFLOW's farm process

The extension of MODFLOW onto the landscape with the Farm Process (MF-FMP) facilitates fully coupled simulation of the use and movement of water from precipitation, streamflow and runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. This allows for more complete analysis of conjunctive use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within "water-balance subregions" comprised of one or more model cells that can represent a single farm, a group of farms, or other hydrologic or geopolitical entities. Simulation of micro-agriculture in the Pajaro Valley and macro-agriculture in the Central Valley are used to demonstrate the utility of MF-FMP. For Pajaro Valley, the simulation of an aquifer storage and recovery system and related coastal water distribution system to supplant coastal pumpage was analyzed subject to climate variations and additional supplemental sources such as local runoff. For the Central Valley, analysis of conjunctive use from different hydrologic settings of northern and southern subregions shows how and when precipitation, surface water, and groundwater are important to conjunctive use. The examples show that through MF-FMP's ability to simulate natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand can be analyzed, understood, and managed. This analysis of conjunctive use would be difficult without embedding them in the simulation and are difficult to estimate a priori.

Can soaked-in scavengers protect metalloprotein active sites from reduction during data collection?

One of the first events taking place when a crystal of a metalloprotein is exposed to X-ray radiation is photoreduction of the metal centres. The oxidation state of a metal cannot always be determined from routine X-ray diffraction experiments alone, but it may have a crucial impact on the metal's environment and on the analysis of the structural data when considering the functional mechanism of a metalloenzyme. Here, UV-Vis microspectrophotometry is used to test the efficacy of selected scavengers in reducing the undesirable photoreduction of the iron and copper centres in myoglobin and azurin, respectively, and X-ray crystallography to assess their capacity of mitigating global and specific radiation damage effects. UV-Vis absorption spectra of native crystals, as well as those soaked in 18 different radioprotectants, show dramatic metal reduction occurring in the first 60 s of irradiation with an X-ray beam from a third-generation synchrotron source. Among the tested radioprotectants only potassium hexacyanoferrate(III) seems to be capable of partially mitigating the rate of metal photoreduction at the concentrations used, but not to a sufficient extent that would allow a complete data set to be recorded from a fully oxidized crystal. On the other hand, analysis of the X-ray crystallographic data confirms ascorbate as an efficient protecting agent against radiation damage, other than metal centre reduction, and suggests further testing of HEPES and 2,3-dichloro-1,4-naphtoquinone as potential scavengers.

Direct methods and residue type specific isotope labeling in NMR structure determination and model-driven sequential assignment

Direct methods in NMR based structure determination start from an unassigned ensemble of unconnected gaseous hydrogen atoms. Under favorable conditions they can produce low resolution structures of proteins. Usually a prohibitively large number of NOEs is required, to solve a protein structure ab-initio, but even with a much smaller set of distance restraints low resolution models can be obtained which resemble a protein fold. One problem is that at such low resolution and in the absence of a force field it is impossible to distinguish the correct protein fold from its mirror image. In a hybrid approach these ambiguous models have the potential to aid in the process of sequential backbone chemical shift assignment when (13)C(beta) and (13)C' shifts are not available for sensitivity reasons. Regardless of the overall fold they enhance the information content of the NOE spectra. These, combined with residue specific labeling and minimal triple-resonance data using (13)C(alpha) connectivity can provide almost complete sequential assignment. Strategies for residue type specific labeling with customized isotope labeling patterns are of great advantage in this context. Furthermore, this approach is to some extent error-tolerant with respect to data incompleteness, limited precision of the peak picking, and structural errors caused by misassignment of NOEs.

Intravenous immunoglobulins induce CD32-mediated platelet aggregation in vitro

BACKGROUND

Intravenous immunoglobulins (IVIg) and cytomegalovirus immunoglobulins (CMVIg) are currently finding increased acceptance in clinical states of high immune activity and in transplant recipients. A rare side-effect of their application is intravascular thrombosis, which is thought to be related to pre-existing hyperviscosity. In a previous study we have shown that rabbit antithymocyte globulin causes platelet aggregation in vitro via the Fc IgG receptor (CD32).

OBJECTIVES

To investigate if IVIg and CMVIg have the potential to cause CD32-dependent platelet aggregation.

METHODS

The influence of CMVIg or IVIg on platelets pre-incubated with or without monoclonal antibody AT10 was studied in an aggregometer. Expression of platelet surface activation marker CD62P was determined by fluorescence-activated cell sorting analysis and presence of soluble CD40L (sCD40L) was evaluated by enzyme-linked immunosorbent assay. All in vitro experiments were performed using platelet concentrates from the blood bank, at therapeutic concentrations of immunoglobulins. Results Incubation of platelets with CMVIg and IVIg markedly induced platelet aggregation, and increased expression of CD62P and secretion of sCD40L. The capacity of CMVIg and IVIg to induce platelet aggregation was completely abrogated by adding the blocking antibody AT10 directed against the low-affinity Fc IgG receptor (CD32).

CONCLUSIONS

Our results suggest that CMVIg and IVIg solutions with activating Fc domains are able to bind CD32 on platelets and cause platelet aggregation in vitro. These results indicate a mechanism by which in vivo intravascular thrombosis may be explained and suggest caution with concomitant use of packed platelets and IVIg in autoimmune diseases in the clinical setting.

α-Lipoic acid in dietary supplements: Development and comparison of HPLC-CEAD and HPLC-ESI-MS methods

Alpha-lipoic acid is an antioxidant used both in the prevention and treatment of various oxidative stress related diseases. It is an important constituent of some dietary supplements and can also be found in plant and animal sources. A rapid method for the determination of alpha-lipoic acid in dietary supplements based on high performance liquid chromatography coupled with a coulometric electrode array detector (CEAD) and an electrospray ionization mass spectrometer (ESI-MS) was developed. First, alpha-lipoic acid was extracted with methanol by sonication, chromatographic separation was then achieved by isocratic elution [acetonitrile/methanol/50mM potassium dihydrogen phosphate (pH 3, adjusted with phosphoric acid): 350/65/585, v/v/v] using an ACE 3-C-18 column at a flow rate of 0.45 ml/min. alpha-Lipoic acid was detected by means of a CEAD at +300, +400, +450, +500, +550, +600, +650, and +700 mV against palladium reference electrodes. For ESI-MS detection (negative mode), the composition of the mobile phase was changed to 0.1% acetic acid in water/acetonitrile 55:45, v/v applying a flow rate of 0.2 ml/min. The presented methods were utilized to determine the alpha-lipoic acid content in six dietary supplements. The results of both detection modes were in good correlation.

[Subacute weakness of the lower limbs]

Complete and isolated herniation of the urinary bladder is extremely rare, and the consecutive appearance of bilateral urethral obstruction and renal failure is even rarer. We report about a 73 year old male presenting with massive nausea and muscular weakness. On physical examination he showed a giant inguinal hernia with involvement of the entire bladder along with evidence of bilateral hydronephrosis. His serum creatinine and potassium levels were markedly elevated most likely leading to his presenting symptoms of azotemia (nausea) and hyperkalemia (weakness). After transscrotal drainage and decompression of the bladder, a transurethral catheter was inserted. After gaining full renal recovery, the hernia was repaired successfully performing the Lichtenstein procedure.

Generation and relaxation of high rank coherences in AX3 systems in a selectively methionine labelled SH2 domain

The usefulness of selective isotope labelling patterns is demonstrated using the C-terminal SH2 domain of PLC-gamma1 selectively 13C labelled at methionine methyl groups. We demonstrate the generation and relaxation of coherences that are second rank in protons and first rank in carbons that derive from quadrupolar order in protons. The decay rates of second rank double quantum proton coherences are measured. These terms exhibit fewer channels for cross-correlated relaxation compared to single quantum coherences. Our results indicate the potential application of the measurement of high order proton coherences to the analysis of dynamics in methyl-bearing side chains.

Microarray analysis of newly synthesized RNA in cells and animals

Current methods to analyze gene expression measure steady-state levels of mRNA. To specifically analyze mRNA transcription, we have developed a technique that can be applied in vivo in intact cells and animals. Our method makes use of the cellular pyrimidine salvage pathway and is based on affinity-chromatographic isolation of thiolated mRNA. When combined with data on mRNA steady-state levels, this method is able to assess the relative contributions of mRNA synthesis and degradation/stabilization. It overcomes limitations associated with currently available methods such as mechanistic intervention that disrupts cellular physiology, or the inability to apply the techniques in vivo. Our method was first tested in serum response of cultured fibroblast cells and then applied to the study of renal ischemia reperfusion injury, demonstrating its applicability for whole organs in vivo. Combined with data on mRNA steady-state levels, this method provided a detailed analysis of regulatory mechanisms of mRNA expression and the relative contributions of RNA synthesis and turnover within distinct pathways, and identification of genes expressed at low abundance at the transcriptional level.