Highly regioselective hydrolysis of tricarballylates (“retro-fats”) and citrates by subtilisin

Trimethyl and triethyl esters of tricarballylic acid and citric acid were hydrolysed with porcine liver esterase(PLE) to the isomeric diesters. In all cases the hydrolysis took place with poor regioselectivity (maximum 50% excess). However, the hydrolysis of trimethyl and triethyl esters of tricarballylic acid and of the triethyl ester of citric acid with subtilisin was absolutely regioselective and the symmetric 1,5-diester was obtained.     

Histological changes in rat duodenum mucosa after whole-body gamma irradiation.

In order to understand the mechanisms of intestinal injuries due to ionizing radiation, various groups of rats have been whole-body irradiated by gamma-rays at two dose rates (1 Gy/min and 1 Gy/hr), three doses (1, 2 and 4 Gy) and two post-irradiation times (24 and 48 hr). Duodenum samples of the animals were prepared for light microscopy, according to classical methods for histology and TUNEL reaction. A small number of morphological differences were observed within the mucosa between the two dose rates used. The extent and the number of lesions were more important at the slower dose rate (1 Gy/hr) and increased with the total dose. Clear cavities were seen inside the lamina propria which appeared like capillaries free of blood cells. The mitotic index calculated from crypt cells showed a regular decrease with the dose, which was exacerbated at 48 hr post-irradiation. On the other hand, the apoptotic index increased with the dose and the postirradiation time. Our results lead to hypothesize another mechanism of intestinal mucosa renewal allowing to explain mucosa denudations observed after radiotherapy. Thus we propose a new concept in which the duodenal mucosa renewal may occur by whole villi shedding into the duodenal lumen.     

Urea Transporter UT-B Deletion Induces DNA Damage and Apoptosis in Mouse Bladder Urothelium

Background

Previous studies found that urea transporter UT-B is abundantly expressed in bladder urothelium. However, the dynamic role of UT-B in bladder urothelial cells remains unclear. The objective of this study is to evaluate the physiological roles of UT-B in bladder urothelium using UT-B knockout mouse model and T24 cell line.

Methodology/Principal Findings

Urea and NO measurement, mRNA expression micro-array analysis, light and transmission electron microscopy, apoptosis assays, DNA damage and repair determination, and intracellular signaling examination were performed in UT-B null bladders vs wild-type bladders and in vitro T24 epithelial cells. UT-B was highly expressed in mouse bladder urothelium. The genes, Dcaf11, MCM2-4, Uch-L1, Bnip3 and 45 S pre rRNA, related to DNA damage and apoptosis were significantly regulated in UT-B null urothelium. DNA damage and apoptosis highly occurred in UT-B null urothelium. Urea and NO levels were significantly higher in UT-B null urothelium than that in wild-type, which may affect L-arginine metabolism and the intracellular signals related to DNA damage and apoptosis. These findings were consistent with the in vitro study in T24 cells that, after urea loading, exhibited cell cycle delay and apoptosis.

Conclusions/Significance

UT-B may play an important role in protecting bladder urothelium by balancing intracellular urea concentration. Disruption of UT-B function induces DNA damage and apoptosis in bladder, which can result in bladder disorders.     

Prognostic molecular markers in pediatric liver disease – Are there any?

Pediatric liver disease (PLD) is a major cause of severe morbidity and prolonged hospitalizations in children. Stratifying patients in terms of prognosis remains challenging. The limited knowledge about molecular mechanisms causing and accompanying PLD remains the main obstacle in a search for reliable prognostic biomarkers. A systematic search of MEDLINE via PubMed and Embase via OVID was conducted on studies published between August 2007 and August 2017. Molecular markers with a prognostic potential in terms of survival, need for liver transplantation or disease progression/regression were selected. In general, identified studies were single center smaller case-control studies or case series with a low level of evidence and a high risk of bias. Only 23 studies comprising 898 patients could be included, mostly focusing on biliary atresia, non-alcoholic fatty liver disease, viral hepatitis, and LT; and markers related to morphogenesis and fibrosis. Furthermore, molecular markers in metabolic pathways and inflammation shown to be relevant, however requiring further validation. Hence, further biological and clinical studies are needed to gain greater molecular insight into PLD.     

Impacts of Brain Serotonin Deficiency following Tph2 Inactivation on Development and Raphe Neuron Serotonergic Specification

Brain serotonin (5-HT) is implicated in a wide range of functions from basic physiological mechanisms to complex behaviors, including neuropsychiatric conditions, as well as in developmental processes. Increasing evidence links 5-HT signaling alterations during development to emotional dysregulation and psychopathology in adult age. To further analyze the importance of brain 5-HT in somatic and brain development and function, and more specifically differentiation and specification of the serotonergic system itself, we generated a mouse model with brain-specific 5-HT deficiency resulting from a genetically driven constitutive inactivation of neuronal tryptophan hydroxylase-2 (Tph2). Tph2 inactivation (Tph2-/-) resulted in brain 5-HT deficiency leading to growth retardation and persistent leanness, whereas a sex- and age-dependent increase in body weight was observed in Tph2+/- mice. The conserved expression pattern of the 5-HT neuron-specific markers (except Tph2 and 5-HT) demonstrates that brain 5-HT synthesis is not a prerequisite for the proliferation, differentiation and survival of raphe neurons subjected to the developmental program of serotonergic specification. Furthermore, although these neurons are unable to synthesize 5-HT from the precursor tryptophan, they still display electrophysiological properties characteristic of 5-HT neurons. Moreover, 5-HT deficiency induces an up-regulation of 5-HT(1A) and 5-HT(1B) receptors across brain regions as well as a reduction of norepinephrine concentrations accompanied by a reduced number of noradrenergic neurons. Together, our results characterize developmental, neurochemical, neurobiological and electrophysiological consequences of brain-specific 5-HT deficiency, reveal a dual dose-dependent role of 5-HT in body weight regulation and show that differentiation of serotonergic neuron phenotype is independent from endogenous 5-HT synthesis.     

Effectiveness of a Training Course for General Practice Nurses in Motivation Support in Type 2 Diabetes Care: A Cluster-Randomised Trial

Background

Type 2 diabetes is a common metabolic disease with the potential for prevention of complications. The prevention requires a high level of lasting actions from the patients, which may be burdensome. The aim of this trial was to evaluate the effectiveness of a training course for general practice nurses in motivation support at 18 months follow-up in the affiliated type 2 diabetes population.

Methods

Forty general practices with nurse-led diabetes consultations from the area of Aarhus, Denmark were randomised 1∶1 to either intervention or usual practice. Intervention practices were offered a 16-hour Self-determination theory - based course including communication training for general practice nurses delivered over 10 months. The affiliated diabetes populations (aged 40–74 years) were identified from registers (intervention n = 2,005; usual n = 2,029). Primary outcomes were register-based glycated haemoglobin (HbA_1c) -, total cholesterol levels, and well-being measured by the Problem Areas In Diabetes scale (PAID) and the mental component summary score, SF12 (SF12, mcs). Intention-to-treat analyses were performed. Predefined subgroups analyses were performed.

Results

The differences between the intervention- and the control practices’ mean HbA_1c and total cholesterol at follow-up adjusted for baseline values and clustering were respectively: −0.02%-points (95% CI: −0.11 to 0.07; p: 0.67); 0.08 mmol/l (95% CI: 0.01 to 0.15; p: 0.02). Differences in median scores adjusted for clustering were for PAID: 1.25; p = 0.31 and SF12, mcs: 0.99; p = 0.15. Women in intervention practices differed from women in usual practices on mean HbA_1c: −0.12%-points (−0.23 to −0.02; p = 0.02) and SF12, mcs: 2.6; p = 0.01.

Conclusions

Offering a training course for general practice nurses in applying the Self-determination theory in current type 2 diabetes care had no effect compared with usual practice measured by HbA_1c and total cholesterol levels and the well-being at 18 months of follow-up in a comprehensive register-based diabetes population. Subgroup analyses suggested a possible effect in women, which deserves further attention.

Trial Registration

ClinicalTrials.gov (Identifier {"type":"clinical-trial","attrs":{"text":"NCT01187069","term_id":"NCT01187069"}}NCT01187069).     

Multiple roles of heparin in the aggregation of p25α

The 219-residue protein p25α stimulates the fibrillation of α-synuclein (αSN) in vitro and colocalizes with it in several α-synucleinopathies. Although p25α does not fibrillate by itself under native conditions in vitro, αSN-free p25α aggregates have also been observed in vivo in, for example, multiple system atrophy. To investigate which environmental conditions might trigger this aggregation, we investigated the effect of polyanionic biomolecules on p25α aggregation. Heparin, polyglutamate, arachidonic acid micelles, and RNA all induce p25α aggregation. More detailed studies using heparin as template for aggregation reveal that a minimum of 10-14 heparin monosaccharide units per heparin polymer are required. Bona fide fibrils are only formed at intermediate heparin concentrations, possibly because an excess of heparin binding sites blocks the inter-p25α contacts required for amyloid formation. Other polyanions also show an optimum for amyloid formation. Aggregation involves only modest structural changes according to both spectroscopic and proteolytic experiments. The aggregates do not seed aggregation of heparin-free p25α, suggesting that heparin is required in stoichiometric amounts to form organized structures. We are able to reproduce these observations in a model involving two levels of binding of p25α to heparin. We conclude that the modest structural changes that p25α undergoes can promote weak intermolecular contacts and that polyanions such as heparin play a central role in stabilizing these aggregates but in multiple ways, leading to different types of aggregates. This highlights the role of non-protein components in promoting protein aggregation in vivo.     

Emergence, spread, persistence and fade-out of sylvatic plague in Kazakhstan

Predicting the dynamics of zoonoses in wildlife is important not only for prevention of transmission to humans, but also for improving the general understanding of epidemiological processes. A large dataset on sylvatic plague in the Pre-Balkhash area of Kazakhstan (collected for surveillance purposes) provides a rare opportunity for detailed statistical modelling of an infectious disease. Previous work using these data has revealed a host abundance threshold for epizootics, and climatic influences on plague prevalence. Here, we present a model describing the local space-time dynamics of the disease at a spatial scale of 20 × 20 km(2) and a biannual temporal scale, distinguishing between invasion and persistence events. We used a Bayesian imputation method to account for uncertainties resulting from poor data in explanatory variables and response variables. Spatial autocorrelation in the data was accounted for in imputations and analyses through random effects. The results show (i) a clear effect of spatial transmission, (ii) a high probability of persistence compared with invasion, and (iii) a stronger influence of rodent abundance on invasion than on persistence. In particular, there was a substantial probability of persistence also at low host abundance.     

Maternal survival costs in an asocial mammal

Maternal characteristics, social dynamics, and environmental factors can all influence reproduction and survival and shape trade‐offs that might arise between these components of fitness. Short‐lived mammals like the golden‐mantled ground squirrel (GMGS; Callospermophilus lateralis) tend to maximize effort toward current reproduction at the expense of survival but may be complicated by other aspects of the species’ life history and environment. Here, we use 25 years of data (1995–2020) collected from a population of GMGS at the Rocky Mountain Biological Research Laboratory in Gothic, Colorado, to test the effect of several maternal characteristics (e.g., age, experience, and timing of litter emergence), social context (e.g., litter sex ratio and kin density), and environmental context (e.g., date of bare ground and length of vegetative growing season) on survival of reproductive female GMGS using Cox proportional hazard models. Our results indicated that social dynamics (i.e., density) and environmental conditions (i.e., standardized first day of permanent snow cover and length of growing season) explained significant variation in annual maternal survival, while maternal characteristics did not. A higher density of related breeding females and the total number of females (both related and unrelated to the focal mother) were associated with an increase in the mortality hazard. A later standardized date of the first day of permanent snow cover and a shorter growing season both reduced the maternal mortality hazard. Together, our results suggest that factors extrinsic to the squirrels affect maternal survival and thus may also influence local population growth and dynamics in GMGS and other short‐lived, territorial mammal species.