24 research outputs found
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Nucleotidyl Cyclase Activity of Particulate Guanylyl Cyclase A: Comparison with Particulate Guanylyl Cyclases E and F, Soluble Guanylyl Cyclase and Bacterial Adenylyl Cyclases Cyaa and Edema Factor
Guanylyl cyclases (GCs) regulate many physiological processes by catalyzing the synthesis of the second messenger cGMP. The GC family consists of seven particulate GCs (pGCs) and a nitric oxide-activated soluble GC (sGC). Rat sGC α1β1 possesses much broader substrate specificity than previously assumed. Moreover, the exotoxins CyaA from Bordetella pertussis and edema factor (EF) from Bacillus anthracis possess nucleotidyl cyclase (NC) activity. pGC-A is a natriuretic peptide-activated homodimer with two catalytic sites that act cooperatively. Here, we studied the NC activity of rat pGC-A in membranes of stably transfected HEK293 cells using a highly sensitive and specific HPLC-MS/MS technique. GTP and ITP were effective, and ATP and XTP were only poor, pGC-A substrates. In contrast to sGC, pGC-A did not use CTP and UTP as substrates. pGC-E and pGC-F expressed in bovine rod outer segment membranes used only GTP as substrate. In intact HEK293 cells, pGC-A generated only cGMP. In contrast to pGCs, EF and CyaA showed very broad substrate-specificity. In conclusion, NCs exhibit different substrate-specificities, arguing against substrate-leakiness of enzymes and pointing to distinct physiological functions of cyclic purine and pyrimidine nucleotides.</p
Photonic flip-chip assembly of InP on TriPleX with laser soldering
We present a photonic flip-chip assembly for a 4 mm × 4.6 mm InP die with 58 electrical connections on a 16 mm × 8 mm TriPleX die by using laser soldering. Two laser soldering schemes are investigated and show reliable contacts with a 6 N shear force: (1) using a laser wavelength where silicon is highly transmissive (through-silicon laser soldering) and (2) using a laser wavelength where silicon is not transmissive (heat-conduction laser soldering)
The ReCoDe addiction research consortium:Losing and regaining control over drug intake-Findings and future perspectives
Substance use disorders (SUDs) are seen as a continuum ranging from goal-directed and hedonic drug use to loss of control over drug intake with aversive consequences for mental and physical health and social functioning. The main goals of our interdisciplinary German collaborative research centre on Losing and Regaining Control over Drug Intake (ReCoDe) are (i) to study triggers (drug cues, stressors, drug priming) and modifying factors (age, gender, physical activity, cognitive functions, childhood adversity, social factors, such as loneliness and social contact/interaction) that longitudinally modulate the trajectories of losing and regaining control over drug consumption under real-life conditions. (ii) To study underlying behavioural, cognitive and neurobiological mechanisms of disease trajectories and drug-related behaviours and (iii) to provide non-invasive mechanism-based interventions. These goals are achieved by: (A) using innovative mHealth (mobile health) tools to longitudinally monitor the effects of triggers and modifying factors on drug consumption patterns in real life in a cohort of 900 patients with alcohol use disorder. This approach will be complemented by animal models of addiction with 24/7 automated behavioural monitoring across an entire disease trajectory; i.e. from a naïve state to a drug-taking state to an addiction or resilience-like state. (B) The identification and, if applicable, computational modelling of key molecular, neurobiological and psychological mechanisms (e.g., reduced cognitive flexibility) mediating the effects of such triggers and modifying factors on disease trajectories. (C) Developing and testing non-invasive interventions (e.g., Just-In-Time-Adaptive-Interventions (JITAIs), various non-invasive brain stimulations (NIBS), individualized physical activity) that specifically target the underlying mechanisms for regaining control over drug intake. Here, we will report on the most important results of the first funding period and outline our future research strategy.</p
Immunomodulation and Postpartum Relapses in Patients with Multiple Sclerosis
Multiple sclerosis (MS) mainly affects young women during a life period with
desire for children. Relapse rate decreases during pregnancy and rises after
delivery. Therefore, studies on satisfactory postpartum relapse prevention and
its efficacy are essential. Previous smaller and uncontrolled studies suggested
that intravenous immunoglobulin (IVIG) administration reduced the relapse rate
following delivery. The objective of our observational study was to compare the
efficacy of IVIG application, treatment with other immunomodulatory compounds or
no treatment at all on the postpartal relapse rate in female MS patients from
our pregnancy database. One hundred and twenty four pregnancies were followed in
a partly prospective design. Relapse rate was reduced during pregnancy (p50.001)
and increased during the initial 3 months after delivery in all MS patients
(p50.001). The relapse rate reduction showed only a trend in favour of the
IVIG-treated women, probably due to the small number of patients. However,
analysing the expected number of relapses, IVIG treated patients had
significantly less relapses postpartum than the untreated control group matched
for disease activity before and during pregnancy (χ2,
p
= 0.013). The results suggest that IVIG could be an option to
prevent postpartum relapse of MS