Dietary phytosterols and phytostanols decrease cholesterol levels but increase blood pressure in WKY inbred rats in the absence of salt-loading

<p>Abstract</p> <p>Background</p> <p>There are safety concerns regarding widespread consumption of phytosterol and phytostanol supplemented food products. The aim of this study was to determine, in the absence of excess dietary salt, the individual effects of excess accumulation of dietary phytosterols and phytostanols on blood pressure in Wistar Kyoto (WKY) <it>inbred </it>rats that have a mutation in the <it>Abcg5 </it>gene and thus over absorb phytosterols and phytostanols.</p> <p>Methods</p> <p>Thirty 35-day old male WKY <it>inbred </it>rats (10/group) were fed a control diet or a diet containing phytosterols or phytostanols (2.0 g/kg diet) for 5 weeks. The sterol composition of the diets, plasma and tissues were analysed by gas chromatography. Blood pressure was measured by the tail cuff method. mRNA levels of several renal blood pressure regulatory genes were measured by real-time quantitative PCR.</p> <p>Results</p> <p>Compared to the control diet, the phytosterol diet resulted in 3- to 4-fold increases in the levels of phytosterols in plasma, red blood cells, liver, aorta and kidney of WKY <it>inbred </it>rats (<it>P </it>< 0.05). The phytostanol diet dramatically increased (> 9-fold) the levels of phytostanols in plasma, red blood cells, liver, aorta and kidney of these rats (<it>P </it>< 0.05). The phytosterol diet decreased cholesterol levels by 40%, 31%, and 19% in liver, aorta and kidney, respectively (<it>P </it>< 0.05). The phytostanol diet decreased cholesterol levels by 15%, 16%, 20% and 14% in plasma, liver, aorta and kidney, respectively (<it>P </it>< 0.05). The phytostanol diet also decreased phytosterol levels by 29% to 54% in plasma and tissues (<it>P </it>< 0.05). Both the phytosterol and phytostanol diets produced significant decreases in the ratios of cholesterol to phytosterols and phytostanols in plasma, red blood cells, liver, aorta and kidney. Rats that consumed the phytosterol or phytostanol diets displayed significant increases in systolic and diastolic blood pressure compared to rats that consumed the control diet (<it>P </it>< 0.05). The phytosterol diet increased renal <it>angiotensinogen </it>mRNA levels of these rats.</p> <p>Conclusion</p> <p>These data suggest that excessive accumulation of dietary phytosterols and phytostanols in plasma and tissues may contribute to the increased blood pressure in WKY <it>inbred </it>rats in the absence of excess dietary salt. Therefore, even though phytosterols and phytostanols lower cholesterol levels, prospective clinical studies testing the net beneficial effects of dietary phytosterols and phytostanols on cardiovascular events for subgroups of individuals that have an increased incorporation of these substances are needed.</p

Breaking down barriers to consistent, climate-smart regulation of invasive plants - a case study of northeast states

Efforts to prevent the introduction and spread of new invasive plants are most effective when regulated species are consistent across jurisdictional boundaries and proactively prohibit species before they arrive or in the earliest stages of invasion. Consistent and proactive regulation is particularly important in the northeast U.S. which is susceptible to many new invasive plants due to climate change. Unfortunately, recent analyses of state regulated plant lists show that regulated species are neither consistent nor proactive. To understand why, we focus on two steps leading to invasive plant regulation across six northeast states (Connecticut, Maine, Massachusetts, New Hampshire, New York, and Vermont): which sets of species are evaluated and how risk is assessed. Our analysis confirms previous findings that invasive plant regulations are inconsistent and reactive. Of the 128 plants regulated by one or more states, 54 were regulated by a single state and only 16 were regulated by all six states; regulated species tended to be widespread across the region (not proactive). These outcomes are largely driven by different sets of evaluated species. For example, neighboring states Vermont and New Hampshire evaluated 92 species in total, but only 26 overlapped. In addition, states rarely evaluated species that were absent from the state. Risk assessment protocols varied considerably across states, but consistently included criteria related to ecological impact, potential to establish, dispersal mechanisms, and life history traits. While none of the assessments explicitly consider climate change, they also did not contain language that would preclude regulating species that have not yet arrived in the state. To increase consistency and proactivity, states would benefit from 1) evaluating species identified as high risk by neighboring states as well as high risk, range-shifting invasives, both of which we compiled here and 2) explicitly considering climate change when assessing ‘potential distribution’ or ‘potential impact’ of target species. Additionally, a mechanism for sharing knowledge and risk assessments regionally would benefit states with fewer resources to address invasive species threats. Presenting a unified defense against current and future threats is critical for reducing impacts from invasive species and is achievable with better state-to-state coordination

Two classes of nonlocal Evolution Equations related by a shared Traveling Wave Problem

We consider reaction-diffusion equations and Korteweg-de Vries-Burgers (KdVB) equations, i.e. scalar conservation laws with diffusive-dispersive regularization. We review the existence of traveling wave solutions for these two classes of evolution equations. For classical equations the traveling wave problem (TWP) for a local KdVB equation can be identified with the TWP for a reaction-diffusion equation. In this article we study this relationship for these two classes of evolution equations with nonlocal diffusion/dispersion. This connection is especially useful, if the TW equation is not studied directly, but the existence of a TWS is proven using one of the evolution equations instead. Finally, we present three models from fluid dynamics and discuss the TWP via its link to associated reaction-diffusion equations

Finite to infinite steady state solutions, bifurcations of an integro-differential equation

We consider a bistable integral equation which governs the stationary solutions of a convolution model of solid--solid phase transitions on a circle. We study the bifurcations of the set of the stationary solutions as the diffusion coefficient is varied to examine the transition from an infinite number of steady states to three for the continuum limit of the semi--discretised system. We show how the symmetry of the problem is responsible for the generation and stabilisation of equilibria and comment on the puzzling connection between continuity and stability that exists in this problem

Maximum principles for nonlocal parabolic Waldenfels operators

As a class of Levy type Markov generators, nonlocal Waldenfels operators appear naturally in the context of investigating stochastic dynamics under Levy fluctuations and constructing Markov processes with boundary conditions (in particular the construction with jumps). This work is devoted to prove the weak and strong maximum principles for ‘parabolic’ equations with nonlocal Waldenfels operators. Applications in stochastic differential equations with α-stable Levy processes are presented to illustrate the maximum principles

Two-step solid-state synthesis of PEPPSI-type compounds

peer-reviewedThe two-step mechanochemical preparation of carbene–pyridine complexes of palladium and platinum is reported. The organometallic products, which represent a class of commercially available catalysts, are rapidly formed in excellent yield proving solvent-free synthesis to be a viable synthetic alternative even in the case of NHC-containing compounds

Pushed traveling fronts in monostable equations with monotone delayed reaction

We study the existence and uniqueness of wavefronts to the scalar reaction-diffusion equations $u_{t}(t,x) = \Delta u(t,x) - u(t,x) + g(u(t-h,x)),$ with monotone delayed reaction term $g: \R_+ \to \R_+$ and $h >0$. We are mostly interested in the situation when the graph of $g$ is not dominated by its tangent line at zero, i.e. when the condition $g(x) \leq g'(0)x,$ $x \geq 0$, is not satisfied. It is well known that, in such a case, a special type of rapidly decreasing wavefronts (pushed fronts) can appear in non-delayed equations (i.e. with $h=0$). One of our main goals here is to establish a similar result for $h>0$. We prove the existence of the minimal speed of propagation, the uniqueness of wavefronts (up to a translation) and describe their asymptotics at $-\infty$. We also present a new uniqueness result for a class of nonlocal lattice equations.Comment: 17 pages, submitte

New species of Mesoplia (Hymenoptera, Apidae) from Mesoamerica.

36 p. : ill. (some col.) ; 26 cm.This paper investigates the bionomics of the cleptoparasitic bee Mesoplia sapphirina Melo and Rocha-Filho, sp. nov. (described in the appendix), and of its ground-nesting host Centris flavofasciata Friese found along the Pacific coast of Guanacaste Province, Costa Rica. We explore the host-nest searching behavior, egg deposition, and hospicidal behavior of M. sapphirina. Anatomical accounts of its egg, first, second, and fifth larval instars are presented and compared with published descriptions of other ericrocidine taxa. Nests of the host bee as well as its egg and method of eclosion are also described