The isotopic biosignatures of photo- vs. thiotrophic bivalves: are they preserved in fossil shells?

Symbiont-bearing and non-symbiotic marine bivalves were used as model organisms to establish biosignatures for the detection of distinctive symbioses in ancient bivalves. For this purpose, the isotopic composition of lipids (δ13C) and bulk organic shell matrix (δ13C, δ34S, δ15N) from shells of several thiotrophic, phototrophic, or non-symbiotic bivalves were compared (phototrophic: Fragum fragum, Fragum unedo, Tridacna maxima; thiotrophic: Codakia tigerina, Fimbria fimbriata, Anodontia sp.; non-symbiotic: Tapes dorsatus, Vasticardium vertebratum, Scutarcopagia sp.). ∆13C values of bulk organic shell matrices, most likely representing mainly original shell protein/chitin biomass, were depleted in thio- and phototrophic bivalves compared to non-symbiotic bivalves. As the bulk organic shell matrix also showed a major depletion of δ15N (down to -2.2 ‰) for thiotrophic bivalves, combined δ13C and δ15N values are useful to differentiate between thio-, phototrophic, and non-symbiotic lifestyles. However, the use of these isotopic signatures for the study of ancient bivalves is limited by the preservation of the bulk organic shell matrix in fossils. Substantial alteration was clearly shown by detailed microscopic analyses of fossil (late Pleistocene) T. maxima and Trachycardium lacunosum shell, demonstrating a severe loss of quantity and quality of bulk organic shell matrix with time. Likewise, the composition and δ13C-values of lipids from empty shells indicated that a large part of these compounds derived from prokaryotic decomposers. The use of lipids from ancient shells for the reconstruction of the bivalve's life style therefore appears to be restricted.

[Dementia Care Manager for patients with dementia. Determination of the requirements and qualifications contents for nurses in the DelpHi-MV study]. / Dementia Care Manager für Patienten mit Demenz. Ermittlung des Anforderungsprofils und der Qualifizierungsinhalte für Pflegefachpersonen in der DelpHi-MV-Studie.

Dementia is one of the most prevalent chronic progressive diseases in older age. The progression of dementia is associated with an increasing demand for patient care. Thus, the nursing profession fulfills important tasks in the supply of care in dementia. Care of dementia patients requires nurses with more specialized professional knowledge. Consequently, the development of new qualification concepts in dementia is needed. Therefore, the German Center for Neurodegenerative Diseases, Rostock/Greifswald, has developed a qualification according to the Dementia Care Management concept. A prospective cross-sectional study identified the tasks and qualifications of nurses as Dementia Care Managers. Overall, 27 tasks and 28 qualification items were identified for a nurse to qualify as a Dementia Care Manager. In the next step, the first version of the Dementia Care Management Curriculum was developed.

Altered localization, abnormal modification and loss of function of Sigma receptor-1 in amyotrophic lateral sclerosis.

Intracellular accumulations of mutant, misfolded proteins are major pathological hallmarks of amyotrophic lateral sclerosis (ALS) and related disorders. Recently, mutations in Sigma receptor 1 (SigR1) have been found to cause a form of ALS and frontotemporal lobar degeneration (FTLD). Our goal was to pinpoint alterations and modifications of SigR1 in ALS and to determine how these changes contribute to the pathogenesis of ALS. In the present study, we found that levels of the SigR1 protein were reduced in lumbar ALS patient spinal cord. SigR1 was abnormally accumulated in enlarged C-terminals and endoplasmic reticulum (ER) structures of alpha motor neurons. These accumulations co-localized with the 20s proteasome subunit. SigR1 accumulations were also observed in SOD1 transgenic mice, cultured ALS-8 patient's fibroblasts with the P56S-VAPB mutation and in neuronal cell culture models. Along with the accumulation of SigR1 and several other proteins involved in protein quality control, severe disturbances in the unfolded protein response and impairment of protein degradation pathways were detected in the above-mentioned cell culture systems. Furthermore, shRNA knockdown of SigR1 lead to deranged calcium signaling and caused abnormalities in ER and Golgi structures in cultured NSC-34 cells. Finally, pharmacological activation of SigR1 induced the clearance of mutant protein aggregates in these cells. Our results support the notion that SigR1 is abnormally modified and contributes to the pathogenesis of ALS.

[Qualification concept for delegation of medical tasks to nonmedical professional groups. The "Greifswalder 3-level model"]. / Qualifikationskonzept für eine abgestufte Delegation medizinischer Tätigkeiten an nichtärztliche Berufsgruppen. Das "Greifswalder 3-Stufen-Modell".

To manage the current demographics and the expected medical, nursing, and social care needs of the population, structural changes are needed in the German health care system. On the regional level, there is a shortage of general practitioners in Germany. In the future, the number of affected regions will likely increase. These trends require new support strategies, which include the delegation of medical tasks to nonphysician professionals of which nurses and medical assistants are the primary profession. Thus, they will expand their traditional scope of work. However, their traditional training does not qualify them to perform medical tasks responsibly and with high quality. Hence, there is a need for further development of advanced training programs. The goal is to tailor modular advanced training to the specific support needs of the patients. A recent law (GKV-Versorgungsstrukturgesetz, GKV-VStG, 1 January 2012) was passed that specifies and extends the delegation options of medical tasks beyond the restrictions defined in previous German legislation (§ 63, SGB V in 2008). In this article, we present a three-stage model for qualifying nonphysician medical professionals for defined ranges of medical tasks.

Tracking TrkA's trafficking: NGF receptor trafficking controls NGF receptor signaling.

Growth factors such as the neurotrophins promote neuronal survival and shape neuronal morphology. Neurotrophin receptors are located on the surface of axons and dendrites and must convey their signal retrogradely to the nucleus to influence transcription of target genes. The distance between the site of receptor activation and the nucleus is tremendous. How is the retrograde transmission of survival signals being achieved? Recent work showed that signaling endosomes containing neurotrophin receptors and associated downstream kinases undergo retrograde vesicular transport along microtubules, propelled by the molecular motor dynein. The next objective in the "neurotrophin receptor trafficking meets signal transduction field" will be to elucidate the traffic control mechanisms governing the directed movement of signaling endosomes. Much is already known on the trafficking of the receptor for epidermal growth factor, EGFR. We will summarize the known traffic control mechanisms for EGFR and hypothesize whether EGFR-relevant traffic control mechanisms might also be relevant for neurotrophin receptor traffic control. Moreover, we speculate about potential implications of neurotrophin receptor traffic jams for neurodegenerative diseases.

Polymerization of w/o microemulsions for the preparation of transparent SiO2/PMMA nanocomposites.

Reverse w/o microemulsions composed of methyl methacrylate (MMA) forming the oil phase, nonionic surfactants, and water are used for the synthesis of transparent SiO2/PMMA nanocomposites. An inorganic precursor, tetraethoxysilane (Si(OEt)(4), TEOS), is hydrolyzed in the reverse micelles containing aqueous ammonia. During the hydrolysis of TEOS, polymerization of the continuous MMA phase is initiated using AIBN (azobisisobutyronitrile), and after thermal polymerization at 333 K for 12 h, solid blocks of PMMA are obtained in which nanometer-sized silica particles are trapped in the solid polymer matrix. According to small-angle X-ray and dynamic light scattering experiments, the water droplets in MMA microemulsions are 12 nm (R(W) = 13) in diameter, whereas after polymerization of the microemulsion, the SiO2 particles in the transparent SiO2/PMMA composites are 26 nm in diameter. Transmission electron micrographs demonstrate a low degree of agglomeration in the composites. In comparison with materials generated from micelle-free solutions, the particle size distribution is narrow. The reverse micelle-mediated approach produces composites of high transparency comparable with that of pure PMMA.

[Sudden bilateral deafness of luetic origin in an HIV-positive patient]. / Hipoacusia súbita bilateral de origen luético en una paciente HIV positiva.

We present the clinical record of a positive HIV woman that presented with bilateral sudden hearing loss as a sign of neurosyphilis. We discuss the epidemiological, clinical, diagnostic, and therapeutic implications of positive HIV in syphilis.