Über die Wirkung von Amin-Zusätzen auf Größe und Zusammensetzung der 82Br-Retention in neutronenbestrahltem n- und iso-Propylbromid

Mit Hilfe radio-gaschromatographischer Methoden wurde die Wirkung von zahlreichen Aminen auf die retendierte 82Br-Aktivität in neutronenbestrahltem n- und iso-Propylbromid untersucht. Während tertiäre Amine beim n-Propylbromid eine beträchtliche Retentions-Erhöhung hervorrufen, bewirken alle untersuchten Aminzusätze beim iso-Propylbromid eine Retentions-Erniedrigung. Der Betrag der Retentions-Erniedrigung scheint weitgehend der chemischen Reaktionsfähigkeit der Amine mit dem bestrahlten Propylbromid zu entsprechen. Die bemerkenswerte Retentions-Erhöhung durch tertiäre Amine beim n-Propylbromid ist um so größer, je stärker ausgeprägt sein Quartärnisierungs-Vermögen mit n-Propylbromid ist. Gerade hier sollte jedoch nach dem Formalismus der Hofmann sehen Reaktion eine Retentions-Erniedrigung erwartet werden. Die durch tertiäre Amine hervorgerufene Retentions-Erhöhung drückt sich hauptsächlich in der vermehrten Bildung der 82Br-markierten Muttermoleküle aus, die in diesem Falle bis zu 90% der induzierten Gesamtaktivität ausmacht.

Eine Deutung dieser Retentions-Erhöhung kann über die Annahme eines dissoziativen Austausches gegeben werden, der nur beim Zusatz tertiärer Amine zu einer Retentions-Erhöhung führen kann. Es wird weiterhin festgestellt, daß die individuellen 82Br-Reaktionsprodukte stark von der Konstitution des zugesetzten Amins abhängig sind. Eine durch die ionisierende Strahlung im Reaktor bewirkte Retentions-Erhöhung wird durch einen geringen Zusatz von primären aromatischen Aminen weitgehend vermieden.

Das Auftreten von ungesättigten 82Br-Rückstoßverbindungen wie Vinylbromid, 1-Brompropen-l und 2-Brompropen-1 wird beim n-Propylbromid nur in Gegenwart von aromatischen Aminen beobachtet. Unter unseren Bestrahlungsbedingungen (2 Stdn. bei 2,6·1011 n/cm2 sec) jedoch nicht beim reinen n-Propylbromid.

Eine Unterscheidung zwischen den auf „heißem“ und den auf „thermischem“ Wege entstandenen Anteilen der Rückstoßprodukte läßt sich mit Amin-scavengern nicht ohne weiteres treffen.

Novel type of sex pheromone structure identified fromStigmella malella (Stainton) (Lepidoptera: Nepticulidae)

Short-chain unsaturated chiral methyl carbinols are identified as a new class of lepidopteran pheromone components. The natural female-produced pheromone of the banded apple pigmyStigmella malella (=Nepticula malella) (Stainton) (Lepidoptera: Nepticulidae) was identified to be a mixture of (S)-(E)-6,8-nonadien-2-ol and (S)-(Z)-6,8-nonadien-2-ol. For monitoring traps, a 10:3E:Z blend at 100-1000 µg is recommended. It is suggested that pheromones with similar structures may be specific to Nepticulidae and other related microlepidopteran families.

Colonization and infection due to multi-resistant bacteria in neonates: a single center analysis

BACKGROUND

In the last years the prevalence of multi-resistant pathogens (MRPs) has increased. Systemic infections remain important for neonatal morbidity and mortality.

PATIENTS

Neonates born between January 2011 and December 2012 and admitted to the neonatology before their tenth day of life were included into this retrospective analysis. Vancomycin-resistant Enterococci, Methicillin-resistant Staphylococcus aureus, Gram-negative bacilli with Extend Spectrum Beta Lactamase or AMP-C resistance were defined as multi-resistant pathogens (MRPs). MRP positive and negative patients were analyzed regarding clinical risk factors and the incidence of systemic infections.

RESULTS

635 neonates were admitted during the analysis period. In 31 patients MRPs were detected. 2 patients developed MRP-associated infections. Both were discharged without long term health risks. Low gestational age and need for mechanical ventilation were risk factors for colonization with MRPs in the univariat analysis. The incidence density (per 1 000 patient days) for all MRE increased from 0.76 in 2011 to 3.51 in 2012. In contrast the sepsis rate remained stable (14.9% and 14.2%). 2 MRP colonization clusters were detected by routine microbiology swabs. Both could be controlled by appropriate hygienic measures.

CONCLUSIONS

The prevalence of Gram-negative MRPs increased in neonates. Microbiological screening seems to be helpful for early detection of colonization and thus prevention of nosocomial infections with MRPs. Despite the increased attention towards the problems associated with multiresistant bacteria, there are still major efforts needed for prevention and early treatment of sepsis with non-resistant bacteria.

[Advances, limitations and prospects of oncological liver surgery]

Modern oncological liver surgery continues to push the limits of resectability by incorporating an array of new developments in the fields of surgery, anaesthesia and intensive care, oncology, radiology and transplantation medicine. New criteria for determining the resectability of primary and secondary liver tumours have been developed and introduced into national consensus guidelines. Modern tools for improving oncological outcome include the rapid induction of liver hypertrophy prior to major liver resection, downstaging of tumours with advanced chemotherapy protocols, minimally invasive local therapies like radiofrequency ablation and chemo- or radioembolisation, and liver transplantation for non-resectable hepatocellular carcinoma.

The efficacy and safety of long-term Norditropin® treatment in children with Prader-Willi syndrome

Prader-Willi syndrome is a genetic disorder that is associated with short stature, partial growth hormone deficiency, small hands and feet, learning and behavioural problems, and hyperphagia leading to severe, often morbid, obesity. Growth hormone therapy is associated with an improvement in height and body composition. We evaluated the efficacy and safety of long-term growth hormone treatment in a retrospective observational multinational study of 41 prepubertal children (mean age 3.8±3.0 years) with genetically diagnosed Prader-Willi syndrome treated with growth hormone (0.03-0.06 mg/kg/day) for >12 months [mean duration 4.1 (range 0.9-9.5) years]. Height, weight, and body composition measurements were recorded at baseline and at 6 month intervals until last observation. Mean (SD) gain in height at 12 months was 0.9 (0.2) SD score (p<0.0001). At last observation (after approximately 6 years) mean gain in height was 1.3 (0.3) (p=0.0001) with 85% of children achieving height>- 2 SD score. Body composition improved during treatment with an estimated 9.1% increase in lean body mass and 9.1% decrease in fat mass at last observation (p=0.019). Scoliosis was reported in 3 patients at baseline and 8 patients at last observation. Sleep apnoea was recorded in 3 (7.3%) patients. There were no other severe adverse events reported. Long-term growth hormone treatment of prepubertal children with Prader-Willi syndrome was associated with significant improvements in height and body composition. Treatment was well tolerated. The development of scoliosis warrants monitoring by an orthopaedic specialist.

Concept of "awake venovenous extracorporeal membrane oxygenation" in pediatric patients awaiting lung transplantation

In patients awaiting LuTx, MV and ECMO are often the last ways to create a bridge to LuTx. Both interventions are associated with a poor posttransplant outcome and survival rate. To improve the results of these patients, new "bridging-strategies" are necessary. Recent reports demonstrate promising results for the concept of "awake ECMO" in adult patients. To date, no data on this approach in pediatric patients have been available. We therefore describe the use of VV-ECMO as a treatment strategy for RF in awake pediatric patients. It presents our experiences with the first three children treated using this new concept. Mean amount of time on ECMO was 44 days (range, 11.5-109 days). Two patients were successfully bridged to their LuTx. Both are still alive without any recurrences (24 and three months following LuTx). One patient died before a further LuTx after 109 days on ECMO due to adenoviral infection. Although reintubation was necessary in two patients, and total time being awake while on ECMO was <50%, we conclude that the concept of "awake VV-ECMO" is feasible for the treatment of RF and can be used as a "bridging therapy" to LuTx.

3D-QSAR based on quantum-chemical molecular fields: toward an improved description of halogen interactions

Current 3D-QSAR methods such as CoMFA or CoMSIA make use of classical force-field approaches for calculating molecular fields. Thus, they can not adequately account for noncovalent interactions involving halogen atoms like halogen bonds or halogen-π interactions. These deficiencies in the underlying force fields result from the lack of treatment of the anisotropy of the electron density distribution of those atoms, known as the "σ-hole", although recent developments have begun to take specific interactions such as halogen bonding into account. We have now replaced classical force field derived molecular fields by local properties such as the local ionization energy, local electron affinity, or local polarizability, calculated using quantum-mechanical (QM) techniques that do not suffer from the above limitation for 3D-QSAR. We first investigate the characteristics of QM-based local property fields to show that they are suitable for statistical analyses after suitable pretreatment. We then analyze these property fields with partial least-squares (PLS) regression to predict biological affinities of two data sets comprising factor Xa and GABA-A/benzodiazepine receptor ligands. While the resulting models perform equally well or even slightly better in terms of consistency and predictivity than the classical CoMFA fields, the most important aspect of these augmented field-types is that the chemical interpretation of resulting QM-based property field models reveals unique SAR trends driven by electrostatic and polarizability effects, which cannot be extracted directly from CoMFA electrostatic maps. Within the factor Xa set, the interaction of chlorine and bromine atoms with a tyrosine side chain in the protease S1 pocket are correctly predicted. Within the GABA-A/benzodiazepine ligand data set, PLS models of high predictivity resulted for our QM-based property fields, providing novel insights into key features of the SAR for two receptor subtypes and cross-receptor selectivity of the ligands. The detailed interpretation of regression models derived using improved QM-derived property fields thus provides a significant advantage by revealing chemically meaningful correlations with biological activity and helps in understanding novel structure-activity relationship features. This will allow such knowledge to be used to design novel molecules on the basis of interactions additional to steric and hydrogen-bonding features.

Large-area 2D periodic crystalline silicon nanodome arrays on nanoimprinted glass exhibiting photonic band structure effects

Two-dimensional silicon nanodome arrays are prepared on large areas up to 50 cm² exhibiting photonic band structure effects in the near-infrared and visible wavelength region by downscaling a recently developed fabrication method based on nanoimprint-patterned glass, high-rate electron-beam evaporation of silicon, self-organized solid phase crystallization and wet-chemical etching. The silicon nanodomes, arranged in square lattice geometry with 300 nm lattice constant, are optically characterized by angular resolved reflection measurements, allowing the partial determination of the photonic band structure. This experimentally determined band structure agrees well with the outcome of three-dimensional optical finite-element simulations. A 16% photonic bandgap is predicted for an optimized geometry of the silicon nanodome arrays. By variation of the duration of the selective etching step, the geometry as well as the optical properties of the periodic silicon nanodome arrays can be controlled systematically.

Reclassification of diabetes type in pediatric patients initially classified as type 2 diabetes mellitus: 15 years follow-up using routine data from the German/Austrian DPV database

OBJECTIVE

To examine change of diagnosis in patients from the German/Austrian multicenter DPV (Diabetes Patienten Verlaufsdokumentation) database initially classified as type 2 diabetes.

METHODS

Patients aged ≤20 years at onset, diagnosed between 1995 and 2010 were followed for at least 6 months. Chi-square/Wilcoxon tests were performed to compare patient groups according to diabetes type after reclassification.

RESULTS

From 580 study patients, 60 (10.3%) were reclassified, on average 2.4 years after initial diagnosis as follows: 23 (38.3%) as type 1 diabetes; 9 (15%) as maturity onset diabetes of the young (MODY); 20 (33.3%) as "other specific diabetes forms" and 8 (13.3%) as "remission" of type 2 diabetes. Patients reclassified to type 1 were significantly younger (13.5 ± 2.9 versus 14.0 ± 2.6; p=0.027) and more often β-cell antibody positive at disease onset (80.0% versus 31.2%; p=0.002), while patients reclassified as MODY had significantly lower BMI-SDS values than 520 patients with confirmed type 2 diabetes (2.5 ± 1.1 versus 0.9 ± 1.1; p<0.001). The latter were also considerably more obese than patients in "remission" and those reclassified to "other specific diabetes forms".

CONCLUSION

About 10% of patients in the DPV database, initially diagnosed as type 2 diabetes, were retrospectively reclassified.

Olfactory bulb volume and olfactory function in patients with multiple sclerosis

BACKGROUND

Some studies reported olfactory dysfunction in patients with multiple sclerosis (MS). There is no agreement about the most suitable testing method for measuring olfactory function (OF) in MS patients. Recent studies showed that olfactory bulb volume changes with the degree of olfactory dysfunction. We assessed olfactory bulb volume of MS patients with magnetic resonance imaging (MRI) and related it to the OF.

MATERIAL AND METHODS

Volumetric measurements of the right and left olfactory bulb (OB) were performed by manual segmentation within 36 MS patients. Psychophysical testing of the orthonasal OF was performed using threshold-discrimination-identification (TDI) score in MS patients.

RESULTS

Of all MS patients, 44.4% displayed olfactory dysfunction. The TDI score of all 36 MS patients, especially the score of the Identification subtest correlated strongly with neurological scores typical of MS. In patients with a decreased OB volume, there was a positive correlation between volumetry of the OB and OF.

CONCLUSION

OB volumes may provide valuable information about MS patients with olfactory dysfunction. The TDI test and Identification subtest were very sensitive in detecting olfactory dysfunction in MS patients.

Phylogenetic and proteomic analysis of an anaerobic toluene-degrading community

AIMS

This study intended to unravel the physiological interplay in an anaerobic microbial community that degrades toluene under sulfate-reducing conditions combining proteomic and genetic techniques.

METHODS AND RESULTS

An enriched toluene-degrading community (Zz5-7) growing in batch cultures was investigated by DNA- and protein-based analyses. The affiliation and diversity of the community were analysed using 16S ribosomal RNA (rRNA) genes as a phylogenetic marker as well as bssA and dsrAB genes as functional markers. Metaproteome analysis was carried out by a global protein extraction and a subsequent protein separation by two-dimensional gel electrophoresis (2-DE). About 85% of the proteins in the spots were identified by nano-liquid chromatography coupled with electrospray mass spectrometry (nano-LC-ESI-MS/MS) analysis. DNA sequencing of bssA and the most abundant dsrAB amplicons revealed high similarities to a member of the Desulfobulbaceae, which was also predominant according to 16S rRNA gene amplicons. Metaproteome analysis provided 202 unambiguous protein identifications derived from 236 unique protein spots. The proteins involved in anaerobic toluene activation, dissimilatory sulfate reduction, hydrogen production/consumption and autotrophic carbon fixation were mainly affiliated to members of the Desulfobulbaceae and several other Deltaproteobacteria.

CONCLUSION

Phylogenetic and metaproteomic analyses revealed a member of the Desulfobulbaceae as the key player of anaerobic toluene degradation in a sulfate-reducing consortium.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This is the first study that combines genetic and proteomic analyses to indicate the interactions in an anaerobic toluene-degrading microbial consortium.

Efficacy of biorhythmic transdermal combined hormone treatment in relieving climacteric symptoms: a pilot study

OBJECTIVE

To evaluate the efficacy of a combination of bioidentical combined 17β-estradiol and progesterone transdermal delivery system (lipophilic emulsion-type base) to relieve climacteric symptoms. The hormonal replacement was given during a period of 6 months at four different cyclic doses to mimic the normal ovary secretory pattern.

DESIGN

An open, randomized, comparative, between-patient trial conducted over 6 months in 29 menopausal women with climacteric symptoms assessed with the Kupperman index at baseline and during treatments. Saliva and serum values of 17β-estradiol and progesterone were quantitated before treatment and after 3 and 6 months. Pharmacokinetic data following transdermal administration of 17β-estradiol (0.3 mg, daily) and progesterone (100 mg, daily) were calculated from saliva levels using high-performance liquid chromatography analysis.

RESULTS

Improvement in climacteric symptoms was reported in 93% of women evaluated before and after 3 and 6 months of treatment. Values of saliva 17β-estradiol increased after 6 months from 0.6 ± 0.3 pg/mL to 14.1 ± 3.3 pg/mL, and the values of serum 17β-estradiol increased from 3.3 ± 2.8 pg/mL to 80.6 ± 21.9 pg/mL. Of responders, 88% characterized symptom relief as complete. No adverse health-related events were attributed to the bioidentical hormone therapy. Time to maximum saliva concentrations (Tmax), in all experimental cases, was observed after 6 hours. Baseline values were reached within 24 hours, indicating a diurnal rhythm of 17β-estradiol seen in normally cyclic women over the 24-hour period, ie, its daily biological rhythm.

CONCLUSION

Percutaneous absorption of 17β-estradiol, as well as the absorption of progesterone, was associated with relief of climacteric symptoms. The cyclical transdermal delivery of combined bioidentical hormones may be advantageous because it mimics the secretory profiles of 17β-estradiol and progesterone in normally cyclic women over a 28-day period. Larger studies are needed to determine the long-term effects of our therapy.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.