Compensatory mechanisms mitigate the effect of warming and drought on wood formation

Because of global warming, high‐latitude ecosystems are expected to experience increases in temperature and drought events. Wood formation will have to adjust to these new climatic constraints to maintain tree mechanical stability and long‐distance water transport. The aim of this study is to understand the dynamic processes involved in wood formation under warming and drought. Xylogenesis, gas exchange, water relations and wood anatomy of black spruce [Picea mariana (Mill.) B.S.P.] saplings were monitored during a greenhouse experiment where temperature was increased during daytime or night‐time (+6 °C) combined with a drought period. The kinetics of tracheid development expressed as rate and duration of the xylogenesis sub‐processes were quantified using generalized additive models. Drought and warming had a strong influence on cell production, but little effect on wood anatomy. The increase in cell production rate under warmer temperatures, and especially during the night‐time warming at the end of the growing season, resulted in wider tree‐rings. However, the strong compensation between rates and durations of cell differentiation processes mitigates warming and drought effects on tree‐ring structure. Our results allowed quantification of how wood formation kinetics is regulated when water and heat stress increase, allowing trees to adapt to future environmental conditions.     

Presence of cancer cells in gastric lavage of gastric cancer patients as an indicator of advanced disease,predictor of tumour aggressive phenotype and independent prognostic factor for poor survival: The endoluminal metastatic pathway of gastric cancer and GL0/GL1 classification

Objective

As of 2017, the pathobiology of gastric cancer (GC) is far from fully understood; consequently, new methods of basic and advanced research have been proposed and tested. The presence (GL1) vs absence (GL0) of malignant cells exfoliated in gastric lavage (GL) of GC patients was formerly evaluated with diagnostic intent but not for staging or prognostic assessment. We investigated this hitherto unreported application of cytopathology.

Methods

GL was preoperatively and prospectively collected from 80 GC patients and cytologically analysed. The results were compared with the classic clinicopathological features of GC and related to survival. The prognostic value of GL1 was assessed through univariate and multivariate analyses.

Results

GL1 was detected in 36 samples (45%) and correlated with advanced tumour depth (T3‐T4), lymphatic metastasis (N+), distant metastasis (M1) and lymphovascular invasion (LVI1; P=.0317, .0024, .003 and .0028, respectively). Overall survival (OS) was significantly shorter for GL1 (23 months) vs GL0 patients (42 months; P=.005) and GL1 vs GL0 T1 subjects (12.6 vs 47.8 months, P=.0029). Univariate analysis revealed that GL1, N+, M1, LVI1 and advanced stage were significantly associated with OS. Multivariate analysis assessed GL1 as the only independent prognostic factor for worse OS and progression‐free survival (P=.0013 and .0107).

Conclusions

In the present study, GL1 was correlated with advanced disease, aggressive tumour behaviour and poor prognosis. Although additional studies are needed to confirm these findings, the GL0/GL1 classification can be applied to GC patients to achieve higher accuracy in staging, prognostic stratification and treatment selection.     

Chiral Piperazine‐2,5‐dione Derivatives as Effective α‐Glucosidase Inhibitors. Part 4

The potential to inhibit α‐ and β‐glucosidases of a series of chiral piperazine‐2,5‐dione derivatives was investigated. Three of the seven compounds tested, viz., 1, 5b , and 5c , showed to be non competitive inhibitors of α‐glucosidase, whereas they exhibited very low inhibitory activity towards β‐glucosidase. The most active compound, 5c (K_I of α‐glucosidase=5 μm), had a 100‐fold α‐glucosidase/β‐glucosidase inhibitor selectivity.     

Agglomerated Oral Dosage Forms of Artemisinin/β-Cyclodextrin Spray-Dried Primary Microparticles Showing Increased Dissolution Rate and Bioavailability

Artemisinin, a poorly water-soluble antimalarial drug, presents a low and erratic bioavailability upon oral administration. The aim of this work was to study an agglomerated powder dosage form for oral administration of artemisinin based on the artemisinin/β-cyclodextrin primary microparticles. These primary microparticles were prepared by spray-drying a water–methanol solution of artemisinin/β-cyclodextrin. β-Cyclodextrin in spray-dried microparticles increased artemisinin water apparent solubility approximately sixfold. The thermal analysis evidenced a reduction in the enthalpy value associated with drug melting, due to the decrease in drug crystallinity. The latter was also evidenced by powder X-ray diffraction analysis, while ¹³C-NMR analysis indicated the partial complexation with β-cyclodextrin. Agglomerates obtained by sieve vibration of spray-dried artemisinin/β-cyclodextrin primary microparticles exhibited free flowing and close packing properties compared with the non-flowing microparticulate powder. The in vitro dissolution rate determination of artemisinin from the agglomerates showed that in 10 min about 70% of drug was released from the agglomerates, whereas less than 10% of artemisinin was dissolved from raw material powder. Oral administration of agglomerates in rats yielded higher artemisinin plasma levels compared to those of pure drug. In the case of the agglomerated powder, a 3.2-fold increase in drug fraction absorbed was obtained.     

An N-terminal Fragment of the Prion Protein Binds to Amyloid-β Oligomers and Inhibits Their Neurotoxicity in Vivo

A hallmark of Alzheimer disease (AD) is the accumulation of the amyloid-β (Aβ) peptide in the brain. Considerable evidence suggests that soluble Aβ oligomers are responsible for the synaptic dysfunction and cognitive deficit observed in AD. However, the mechanism by which these oligomers exert their neurotoxic effect remains unknown. Recently, it was reported that Aβ oligomers bind to the cellular prion protein with high affinity. Here, we show that N1, the main physiological cleavage fragment of the cellular prion protein, is necessary and sufficient for binding early oligomeric intermediates during Aβ polymerization into amyloid fibrils. The ability of N1 to bind Aβ oligomers is influenced by positively charged residues in two sites (positions 23–31 and 95–105) and is dependent on the length of the sequence between them. Importantly, we also show that N1 strongly suppresses Aβ oligomer toxicity in cultured murine hippocampal neurons, in a Caenorhabditis elegans-based assay, and in vivo in a mouse model of Aβ-induced memory dysfunction. These data suggest that N1, or small peptides derived from it, could be potent inhibitors of Aβ oligomer toxicity and represent an entirely new class of therapeutic agents for AD.     

Group B Streptococcus chimeric capsular polysaccharides as novel multivalent vaccine candidates

Glycoconjugate Journal - The capsular polysaccharide of the human pathogen Group B Streptococcus is a key virulence factor and vaccine candidate that induces protective antibodies when conjugated...     

Effect of High- versus Low-Intensity Supervised Aerobic and Resistance Training on Modifiable Cardiovascular Risk Factors in Type 2 Diabetes; The Italian Diabetes and Exercise Study (IDES)

Background

While current recommendations on exercise type and volume have strong experimental bases, there is no clear evidence from large-sized studies indicating whether increasing training intensity provides additional benefits to subjects with type 2 diabetes.

Objective

To compare the effects of moderate-to-high intensity (HI) versus low-to-moderate intensity (LI) training of equal energy cost, i.e. exercise volume, on modifiable cardiovascular risk factors.

Design

Pre-specified sub-analysis of the Italian Diabetes and Exercise Study (IDES), a randomized multicenter prospective trial comparing a supervised exercise intervention with standard care for 12 months (2005–2006).

Setting

Twenty-two outpatient diabetes clinics across Italy.

Patients

Sedentary patients with type 2 diabetes assigned to twice-a-week supervised progressive aerobic and resistance training plus exercise counseling (n = 303).

Interventions

Subjects were randomized by center to LI (n = 142, 136 completed) or HI (n = 161, 152 completed) progressive aerobic and resistance training, i.e. at 55% or 70% of predicted maximal oxygen consumption and at 60% or 80% of predicted 1-Repetition Maximum, respectively, of equal volume.

Main Outcome Measure(s)

Hemoglobin (Hb) A_1c and other cardiovascular risk factors; 10-year coronary heart disease (CHD) risk scores.

Results

Volume of physical activity, both supervised and non-supervised, was similar in LI and HI participants. Compared with LI training, HI training produced only clinically marginal, though statistically significant, improvements in HbA_1c (mean difference −0.17% [95% confidence interval −0.44,0.10], P = 0.03), triglycerides (−0.12 mmol/l [−0.34,0.10], P = 0.02) and total cholesterol (−0.24 mmol/l [−0.46, −0.01], P = 0.04), but not in other risk factors and CHD risk scores. However, intensity was not an independent predictor of reduction of any of these parameters. Adverse event rate was similar in HI and LI subjects.

Conclusions

Data from the large IDES cohort indicate that, in low-fitness individuals such as sedentary subjects with type 2 diabetes, increasing exercise intensity is not harmful, but does not provide additional benefits on cardiovascular risk factors.

Trial Registration

www.ISRCTN.org ISRCTN-04252749.