Effect of dietary fish oil on blood levels of free fatty acids,ketone bodies and triacylglycerol in humans

Although the reduction of serum triacylglycerol concentrations by dietary fish oil is a well-known effect, the exact mechanism of this effect has not been previously studied in human subjects. Therefore, the aim of this study was (i) to examine the effect of short-term fish oil supplementation on blood concentrations of ketone bodies, free fatty acids and triacylglycerol in healthy humans and (ii) to verify whether the observed relationships between these variables would be consistent with reduced lipolysis and/or enhanced hepatic fatty acid oxidation after fish oil supplementation. Twenty subjects (21–23 years, normal liver function tests) were randomly divided into two groups to supplement their usual diet with either 30 g/d of fish oil (n=11) or olive oil (n=9). Venous blood samples were drawn after an overnight fast, before and after 1, 3 and 7 d of fish oil/olive oil supplementation. Blood concentrations of triacylglycerol and free fatty acids decreased consistently after fish oil supplementation; the reduction was already significant after one day of fish oil (P<0.001 for triacylglycerol andP=0.01 for free fatty acids). In contrast, neither of these blood values changed after olive oil supplementation (P>0.10). No significant changes in glucose, insulin or ketone body levels were observed in either group after supplementation. After fish oil, but not after olive oil supplementation, the ratio of blood ketone body levels to free fatty acid levels increased significantly (P<0.05). Furthermore, after fish oil supplementation only, free fatty acid levels were significantly correlated with levels of ketone bodies (day 7 of supplementation: r=0.90,P<0.001) and triacylglycerol (maximum value on day 3: r=0.77,P<0.01). These findings suggest that reduced lipolysis and increased hepatic β-oxidation/ketogenesis may contribute to reduced triacylglycerol levels after ω3 fatty acid supplementation in humans. Turnover studies are needed in order to further quantitate these processes.     

The value of statistical life in road safety: a meta-analysis

Costs of accidents make up an important part of the total external cost of traffic. A substantial proportion of accident costs is related to fatal accidents. In the evaluation of fatal accident costs the availability of an estimate of the economic value of a statistical life is pivotal. We present an overview of the empirical literature on the value of statistical life in road safety (VOSL), and use meta-analysis to determine variables that explain the variation in VOSL estimates reported in the literature. We show that the magnitude of VOSL estimates depends on the value assessment approach (particularly, stated versus revealed preference), and for contingent valuation studies also on the type of payment vehicle and elicitation format. We explain that VOSL estimates cannot simply be averaged over studies. The magnitude of VOSL is intrinsically linked to the initial level of the risk of being caught up in a fatal traffic accident and to the risk decline implied by the research set-up.     

Kinetics and energetics of subunit dissociation/unfolding of TIM: the importance of oligomerization for conformational persistence and chemical stability of proteins

Kinetics of unfolding and refolding of rabbit muscle triosephosphate isomerase (TIM) were measured as a function of guanidine hydrochloride (GdnHCl) concentration. From the rate constants of these processes, the activation free-energy barriers (delta G++) were calculated using the Arrhenius equation. Assuming a linear dependence of delta G++ on the concentration of GdnHCl, activation energies in the absence of GdnHCl were estimated. The Gibbs free-energy change of dissociation/unfolding (delta G) was determined from GdnHCl unfolding curves in equilibrium. Using these data and the literature value for the bimolecular association rate constant of folded TIM monomers [Zabori, S., Rudolph, R., and Jaenicke, R. (1980) Z. Naturforsch. 35C, 999-1004], a model was developed that fully describes both kinetics and energetics of subunit dissociation/unfolding of TIM. Unfolded TIM monomers are susceptible to proteolytic digestion and thiol oxidation, while native TIM is resistant to both. The present model explains how the dimeric nature of TIM decreases the frequency of subunit unfolding by several orders of magnitude, thus increasing the chemical stability of the protein. Furthermore, the model also explains the recently demonstrated persistence (on a time scale of hours to days) of conformational heterogeneity of native TIM dimers [Rietveld, A. W. M., and Ferreira, S. T. (1996) Biochemistry 35, 7743-7751]. Again, it appears that the dimeric nature of TIM is essential for this behavior.     

Practical limitations of interstitial thermometry during deep hyperthermia

PURPOSE: Intratumor thermometry during hyperthermia treatment is considered important for several reasons. The morbidity that we experienced from interstitially placed catheters in deep-seated tumors gave reason to weigh the advantages and disadvantages against each other. METHODS AND MATERIALS: The available thermometry in 215 patients treated with hyperthermia for deep-seated tumors was analyzed with the aim to evaluate practically feasible intratumor measurements. The influence of intratumor measurements on the treatment procedure was assessed. RESULTS: Total 120 catheters were placed interstitially in 78 patients. Over the years, the percentage of patients with interstitial thermometry decreased considerably. Forty-nine catheters could remain in place during the whole hyperthermia treatment series. The remaining catheters had to be removed for more or less severe complications, including one fatal event. In fact, the interstitial catheters caused the most severe treatment-related morbidity. During 188 of the total 859 treatments, at least one interstitial catheter was available for thermometry. Per treatment with catheter(s) in situ, the average number of intratumor measurement sites was 6.9. The value of interstitial thermometry for power steering during treatment, to both optimize intratumor temperature distribution and prevent toxicity, appeared limited. The mean volume of the tumors with interstitial thermometry was 314 cm3, SD 325. In relation to the large tumor volumes, the thermal dose parameters calculated from the available data is considered to be of limited value. CONCLUSION: In view of the possible severe complications and the limited clinical value of the information achieved by interstitially placed thermometry catheters, interstitial thermometry was not found to routinely benefit the individual patient.     

Preventing Relapse/Recurrence in Recurrent Depression With Cognitive Therapy: A Randomized Controlled Trial.

This article reports on the outcome of a randomized controlled trial of cognitive group therapy (CT) to prevent relapse/recurrence in a group of high-risk patients diagnosed with recurrent depression. Recurrently depressed patients (N = 187) currently in remission following various types of treatment were randomized to treatment as usual, including continuation of pharmacotherapy, or to treatment as usual augmented with brief CT. Relapse/recurrence to major depression was assessed over 2 years. Augmenting treatment as usual with CT resulted in a significant protective effect, which intensified with the number of previous depressive episodes experienced. For patients with 5 or more previous episodes (41% of the sample), CT reduced relapse/recurrence from 72% to 46%. Our findings extend the accumulating evidence that cognitive interventions following remission can be useful in preventing relapse/recurrence in patients with recurrent depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Angiogenesis in wound healing and tumor metastasis

Formation of new blood vessels is essential for several physiological and pathological events, e.g. embryogenesis, wound healing and tumor growth and metastasis. In order to increase the insight into the mechanisms of angiogenesis we have visualized the different components of the microvasculature in human wounds and tumors by immunohistochemistry on the light and electronmicroscopic level. For this purpose, antibodies recognizing distinct markers for human endothelial cells, pericytes and basal lamina were used on freshly frozen or paraformaldehyde-fixed tissue samples. In terms of efficacy, the PAL-E antigen is highly specific for blood vessel endothelium. Its sensitivity is less than other endothelial markers, such as von Willebrand factor and CD 31, as it is not expressed in arterioles. Within the context of the microvasculature alpha-smooth muscle actin and the HMW-MAA chondroitin sulphate proteoglycan are useful markers for pericytes. Type IV Collagen and Laminin can be visualized consistently in the microvascular basal lamina. During the formation of granulation tissue in wound healing a heterogeneity of the expression of endothelial and pericyte markers is found. In the least matured zone in granulation tissue of decubitus lesions and experimental skin wounds microvessels already contained both endothelial cells and pericytes, suggesting a role for both cell types in the early steps of angiogenesis. Regarding the tumor microvasculature, antibodies to von Willebrand factor often failed to stain capillaries, that did show expression of the other endothelial markers studied. Broad staining in pericytes was found for the HMW-MAA chondroitin sulphate proteoglycan. In contrast, these cells only locally expressed alpha-smooth muscle actin. Staining of the basal lamina components Type IV Collagen and Laminin within tumors was not restricted to the microvasculature. Therefore, antibodies recognizing endothelial markers, particularly PAL-E and BMA 120, are preferable as tools to visualize the tumor microvasculature. In accordance with the situation in granulation tissue of wound healing the broad presence of pericytes in the microvasculature of human tumor suggests an involvement of this cell type in tumor angiogenesis. Recent immunohistochemical studies on human tumor lesions indicated that a high number of microvessels adjacent to the tumor as a measure of tumor angiogenesis is an unfavorable prognostic factor in cutaneous melanoma, mammary carcinoma and non-small cell pulmonary carcinoma. This new application of immunohistochemistry represents a valuable, clinically relevant adjunct to the repertoire of the surgical pathologist.     

Topography following keratoplasty in cats is not representative of that in humans

The excurrent duct system of the rat submandibular gland consists of a number of distinct segments. Using the direction of salivary flow as a reference point, these segments are, in order, intercalated duct, granular convoluted tubule, striated duct, excretory duct, main excretory duct (MED), and salivary bladder (which is an expanded portion of the MED). Because these ducts (with the exception of the MED and the salivary bladder) are encased in secretory endpieces, they are difficult to locate and to observe by scanning electron microscopy. A simple method has been devised to rid the gland of these obscuring endpieces so that the detailed architecture of the duct system can be examined. Rat submandibular glands were fixed initially by vascular perfusion with half-strength Karnovsky's fixative. The connective tissue capsule was removed from extirpated glands and the glands remained in fixative for varying lengths of time. For our purposes, a 30-minute immersion in the aldehyde mixture was optimum. After the sublingual gland was removed, the submandibular gland was softly struck with forceps having rounded tips, then shaken in fixative or buffer. The tissue that remained was postfixed in osmium tetroxide. This method results in the complete divestment of nonductular parenchyma from the rat submandibular gland, leaving the duct system clean and ready for microscopic examination.     

Adverse Weather and Commuting Speed

This paper investigates the welfare effect of travelling through congested areas and adverse weather through changes in the speed of individuals’ car trips based on the entire commuting trip. Weather measurements are local and time specific (hourly basis). As most commuters travel twice a day between home and work, we are able to employ panel data techniques, which deals with issues related to unobserved heterogeneity and data selection. We find that travelling through congested areas reduces speed by about 7%. For most commuters the welfare effects of adverse weather conditions are negative but small. However, the commuters’ welfare costs due to rain are rather substantial during the evening peak in congested areas (and up to 12% of the overall commuting costs).     

Modeling the interactions between humics, ions, and mineral surfaces

Model VI and the NICA-Donnan model are two successful models presently available for describing metal ion binding by humic materials. Both models deal with the complexity of the underlying processes (intrinsic heterogeneity, partial correlation between affinity distributions, variable stoichiometry, electrostatics) in a pragmatic way. The parameters of the NICA-Donnan model and their determination are discussed. The current interpretation of the ion-specific "non-ideality" parameters, ni, found in the NICA-Donnan model, emphasizes their role in determining the stoichiometry for the competitive binding of ions. The ratio nM/nH is reflected in the corresponding exchange ratios and the pH dependence of the metal ion binding. Experimental complications occur in testing models. Although Model VI and the NICA-Donnan models have much in common, there are differences that may become more apparent as the models are more widely tested. Recently ion binding to complexes of humics and oxides has been described by combining the NICA-Donnan model (ion binding to humics) with the CD-MUSIC model (ion binding to oxides). The impact of humic to oxide binding on both cation and anion binding is briefly discussed.