Atherosclerosis in aged mice over-expressing the reverse cholesterol transport genes

We determined whether over-expression of one of the three genes involved in reverse cholesterol transport, apolipoprotein (apo) AI, lecithin-cholesterol acyl transferase (LCAT) and cholesteryl ester transfer protein (CETP), or of their combinations influenced the development of diet-induced atherosclerosis. Eight genotypic groups of mice were studied (AI, LCAT, CETP, LCAT/AI, CETP/AI, LCAT/CETP, LCAT/AI/CETP, and non-transgenic) after four months on an atherogenic diet. The extent of atherosclerosis was assessed by morphometric analysis of lipid-stained areas in the aortic roots. The relative influence (R²) of genotype, sex, total cholesterol, and its main sub-fraction levels on atherosclerotic lesion size was determined by multiple linear regression analysis. Whereas apo AI (R² = 0.22, P < 0.001) and CETP (R² = 0.13, P < 0.01) expression reduced lesion size, the LCAT (R² = 0.16, P < 0.005) and LCAT/AI (R² = 0.13, P < 0.003) genotypes had the opposite effect. Logistic regression analysis revealed that the risk of developing atherosclerotic lesions greater than the 50th percentile was 4.3-fold lower for the apo AI transgenic mice than for non-transgenic mice, and was 3.0-fold lower for male than for female mice. These results show that apo AI overexpression decreased the risk of developing large atherosclerotic lesions but was not sufficient to reduce the atherogenic effect of LCAT when both transgenes were co-expressed. On the other hand, CETP expression was sufficient to eliminate the deleterious effect of LCAT and LCAT/AI overexpression. Therefore, increasing each step of the reverse cholesterol transport per se does not necessarily imply protection against atherosclerosis while CETP expression can change specific athero genic scenarios.

Towards sustainable transport: A comparison of demographic and behavioural characteristics of Finnish and international car sharing users

SStrong evidence suggests that the climate is changing and that these changes are largely caused by human activities. A consensus exists among researchers that human activity is causing global warming and that actions to mitigate global warming need to be taken swiftly. The transportation sector, which relies heavily on fossil fuel burning and primarily oil, is one of the big contributors to air pollution problems at local, regional and global levels. It is the fastest growing source of greenhouse gas emissions and is estimated to be responsible for nearly a quarter of global energyrelated carbon dioxide emissions. Car sharing is a mobility solution encouraging its users to decrease private car usage in favour of communal transit and environmental goals. The idea of car sharing originates from the aspiration to decrease personal car ownership and to reduce vehicle distance travelled. This thesis seeks to complement the understanding of Finnish car sharing users and their usage through better categorization. Through better categorization and segmentation of Finnish car sharing users the thesis seeks to provide information for improved marketing insight. Research is done on the demographic and behavioural characteristics of Finnish car sharing users and they are compared with international findings about the characteristics of International car sharing users. The main research problem is Are Finnish car sharing users similar to international ones? A theoretical research framework on the determinants of individual car sharing usage is built based on international research about demographic and behaviouristic characteristics. After this a quantitative survey is performed to the customers of a Finnish car sharing organization. The data analysed in the thesis consist out of 532 answers received from the car sharing organizations customers. The data is analysed with descriptive and other exploratory methods, which create an understanding of Finnish car sharing users. At the end of the analysis the demographic and behavioural characteristics of Finnish car sharing users are compared with international ones. The research findings of the thesis indicate that the demographic and behavioural characteristics of Finnish car sharing usage largely follow those of their international counterparts. Thanks to the thesis results the car sharing organization is able to better target their customers through improved marketing insight.

Transient outward potassium current and Ca2+ homeostasis in the heart: beyond the action potential

Normal central nervous system development relies on accurate intrinsic cellular programs as well as on extrinsic informative cues provided by extracellular molecules. Migration of neuronal progenitors from defined proliferative zones to their final location is a key event during embryonic and postnatal development. Extracellular matrix components play important roles in these processes, and interactions between neurons and extracellular matrix are fundamental for the normal development of the central nervous system. Guidance cues are provided by extracellular factors that orient neuronal migration. During cerebellar development, the extracellular matrix molecules laminin and fibronectin give support to neuronal precursor migration, while other molecules such as reelin, tenascin, and netrin orient their migration. Reelin and tenascin are extracellular matrix components that attract or repel neuronal precursors and axons during development through interaction with membrane receptors, and netrin associates with laminin and heparan sulfate proteoglycans, and binds to the extracellular matrix receptor integrins present on the neuronal surface. Altogether, the dynamic changes in the composition and distribution of extracellular matrix components provide external cues that direct neurons leaving their birthplaces to reach their correct final location. Understanding the molecular mechanisms that orient neurons to reach precisely their final location during development is fundamental to understand how neuronal misplacement leads to neurological diseases and eventually to find ways to treat them.

Purification, partial characterization and role in lipid transport to developing oocytes of a novel lipophorin from the cowpea weevil, Callosobruchus maculatus

Lipid transport in arthropods is achieved by highly specialized lipoproteins, which resemble those described in vertebrate blood. Here we describe purification and characterization of the lipid-apolipoprotein complex, lipophorin (Lp), from adults and larvae of the cowpea weevil Callosobruchus maculatus. We also describe the Lp-mediated lipid transfer to developing oocytes. Lps were isolated from homogenates of C. maculatus larvae and adults by potassio bromide gradient and characterized with respect to physicochemical properties and lipid content. The weevil Lp (465 kDa) and larval Lp (585 kDa), with hydrated densities of 1.22 and 1.14 g/mL, contained 34 and 56% lipids and 9 and 7% carbohydrates, respectively. In both Lps, mannose was the predominant monosaccharide detected by paper chromatography. SDS-PAGE revealed two apolipoproteins in each Lp with molecular masses of 225 kDa (apolipoprotein-I) and 79 kDa (apolipoprotein-II). The lipids were extracted and analyzed by thin-layer chromatography. The major phospholipids found were phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine in adult Lp, and phosphatidylcholine, phosphatidylethanolamine and sphingomyelin in larval Lp. Hydrocarbons, fatty acids and triacylglycerol were the major neutral lipids found in both Lps. Lps labeled in the protein moiety with radioactive iodine (125I-iodine) or in the lipid moiety with fluorescent lipids revealed direct evidence of endocytic uptake of Lps in live oocytes of C. maculatus.

Role of 11β-hydroxysteroid dehydrogenase 2 renal activity in potassium homeostasis in rats with chronic renal failure

Aldosterone concentrations vary in advanced chronic renal failure (CRF). The isozyme 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), which confers aldosterone specificity for mineralocorticoid receptors in distal tubules and collecting ducts, has been reported to be decreased or normal in patients with renal diseases. Our objective was to determine the role of aldosterone and 11β-HSD2 renal microsome activity, normalized for glomerular filtration rate (GFR), in maintaining K+ homeostasis in 5/6 nephrectomized rats. Male Wistar rats weighing 180-220 g at the beginning of the study were used. Rats with experimental CRF obtained by 5/6 nephrectomy (N = 9) and sham rats (N = 10) were maintained for 4 months. Systolic blood pressure and plasma creatinine (Pcr) concentration were measured at the end of the experiment. Sodium and potassium excretion and GFR were evaluated before and after spironolactone administration (10 mg·kg-1·day-1 for 7 days) and 11β-HSD2 activity on renal microsomes was determined. Systolic blood pressure (means ± SEM; Sham = 105 ± 8 and CRF = 149 ± 10 mmHg) and Pcr (Sham = 0.42 ± 0.03 and CRF = 2.53 ± 0.26 mg/dL) were higher (P < 0.05) while GFR (Sham = 1.46 ± 0.26 and CRF = 0.61 ± 0.06 mL/min) was lower (P < 0.05) in CRF, and plasma aldosterone (Pald) was the same in the two groups. Urinary sodium and potassium excretion was similar in the two groups under basal conditions but, after spironolactone treatment, only potassium excretion was decreased in CRF rats (sham = 0.95 ± 0.090 (before) vs 0.89 ± 0.09 µEq/min (after) and CRF = 1.05 ± 0.05 (before) vs 0.37 ± 0.07 µEq/min (after); P < 0.05). 11β-HSD2 activity on renal microsomes was lower in CRF rats (sham = 0.807 ± 0.09 and CRF = 0.217 ± 0.07 nmol·min-1·mg protein-1; P < 0.05), although when normalized for mL GFR it was similar in both groups. We conclude that K+ homeostasis is maintained during CRF development despite normal Pald levels. This adaptation may be mediated by renal 11β-HSD2 activity, which, when normalized for GFR, became similar to that of control rats, suggesting that mineralocorticoid receptors maintain their aldosterone selectivity.

Effect of trimetazidine treatment on the transient outward potassium current of the left ventricular myocytes of rats with streptozotocin-induced type 1 diabetes mellitus

Cardiovascular complications are a leading cause of mortality in patients with diabetes mellitus (DM). The present study was designed to investigate the effects of trimetazidine (TMZ), an anti-angina drug, on transient outward potassium current (Ito) remodeling in ventricular myocytes and the plasma contents of free fatty acid (FFA) and glucose in DM. Sprague-Dawley rats, 8 weeks old and weighing 200-250 g, were randomly divided into three groups of 20 animals each. The control group was injected with vehicle (1 mM citrate buffer), the DM group was injected with 65 mg/kg streptozotocin (STZ) for induction of type 1 DM, and the DM + TMZ group was injected with the same dose of STZ followed by a 4-week treatment with TMZ (60 mg·kg-1·day-1). All animals were then euthanized and their hearts excised and subjected to electrophysiological measurements or gene expression analyses. TMZ exposure significantly reversed the increased plasma FFA level in diabetic rats, but failed to change the plasma glucose level. The amplitude of Ito was significantly decreased in left ventricular myocytes from diabetic rats relative to control animals (6.25 ± 1.45 vs 20.72 ± 2.93 pA/pF at +40 mV). The DM-associated Ito reduction was attenuated by TMZ. Moreover, TMZ treatment reversed the increased expression of the channel-forming alpha subunit Kv1.4 and the decreased expression of Kv4.2 and Kv4.3 in diabetic rat hearts. These data demonstrate that TMZ can normalize, or partially normalize, the increased plasma FFA content, the reduced Ito of ventricular myocytes, and the altered expression Kv1.4, Kv4.2, and Kv4.3 in type 1 DM.

Correlation between sodium and potassium excretion in 24- and 12-h urine samples

Low-sodium and high-potassium diets have been recommended as an adjunct to prevention and treatment of hypertension. Analysis of these nutrients in 24-h urine has been considered the reference method to estimate daily intake of these minerals. However, 24-h urine collection is difficult in epidemiological studies, since urine must be collected and stored in job environments. Therefore, strategies for shorter durations of urine collection at home have been proposed. We have previously reported that collecting urine during a 12-h period (overnight) is more feasible and that creatinine clearance correlated strongly with that detected in 24-h samples. In the present study, we collected urine for 24 h divided into two 12-h periods (from 7:00 am to 7:00 pm and from 7:00 pm to 7:00 am next day). A sample of 109 apparently healthy volunteers aged 30 to 74 years of both genders working in a University institution was investigated. Subjects with previous myocardial infarction, stroke, renal insufficiency, and pregnant women were not included. Significant (P < 0.001) Spearman correlation coefficients (r s) were found between the total amount of sodium and potassium excreted in the urine collected at night and in the 24-h period (r s = 0.76 and 0.74, respectively). Additionally, the 12-h sodium and potassium excretions (means ± SD, 95% confidence interval) corresponded to 47.3 ± 11.2%, 95%CI = 45.3-49.3, and 39.3 ± 4.6%, 95%CI = 37.3-41.3, respectively, of the 24-h excretion of these ions. Therefore, these findings support the assumption that 12-h urine collected at night can be used as a reliable tool to estimate 24-h intake/excretion of sodium and potassium.

Effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity in Chinese subjects: an interventional study

Accumulating evidence has suggested that high salt and potassium might be associated with vascular function. The aim of this study was to investigate the effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity (PWV) in Chinese subjects. Forty-nine subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day NaCl), a high-salt diet for an additional 7 days (18.0 g/day NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day NaCl+4.5 g/day KCl). Brachial-ankle PWV was measured at baseline and on the last day of each intervention. Blood pressure levels were significantly increased from the low-salt to high-salt diet, and decreased from the high-salt diet to high-salt plus potassium supplementation. Baseline brachial-ankle PWV in salt-sensitive subjects was significantly higher than in salt-resistant subjects. There was no significant change in brachial-ankle PWV among the 3 intervention periods in salt-sensitive, salt-resistant, or total subjects. No significant correlations were found between brachial-ankle PWV and 24-h sodium and potassium excretions. Our study indicates that dietary salt intake and potassium supplementation, at least in the short term, had no significant effect on brachial-ankle PWV in Chinese subjects.

The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

It is currently accepted that superoxide anion (O2•−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

Fat gain with physical detraining is correlated with increased glucose transport and oxidation in periepididymal white adipose tissue in rats

As it is a common observation that obesity tends to occur after discontinuation of exercise, we investigated how white adipocytes isolated from the periepididymal fat of animals with interrupted physical training transport and oxidize glucose, and whether these adaptations support the weight regain seen after 4 weeks of physical detraining. Male Wistar rats (45 days old, weighing 200 g) were divided into two groups (n=10): group D (detrained), trained for 8 weeks and detrained for 4 weeks; and group S (sedentary). The physical exercise was carried out on a treadmill for 60 min/day, 5 days/week for 8 weeks, at 50-60% of the maximum running capacity. After the training protocol, adipocytes isolated from the periepididymal adipose tissue were submitted to glucose uptake and oxidation tests. Adipocytes from detrained animals increased their glucose uptake capacity by 18.5% compared with those from sedentary animals (P<0.05). The same cells also showed a greater glucose oxidation capacity in response to insulin stimulation (34.55%) compared with those from the S group (P<0.05). We hypothesize that, owing to the more intense glucose entrance into adipose cells from detrained rats, more substrate became available for triacylglycerol synthesis. Furthermore, this increased glucose oxidation rate allowed an increase in energy supply for triacylglycerol synthesis. Thus, physical detraining might play a role as a possible obesogenic factor for increasing glucose uptake and oxidation by adipocytes.

Improving Cost-Efficiency and Reducing Environmental Impacts of Intermodal Transportation with Dry Port Concept – Major Rail Transport Corridor in Baltic Sea Region

Transportation plays a major role in the gross domestic product of various nations. There are, however, many obstacles hindering the transportation sector. Cost-efficiency along with proper delivery times, high frequency and reliability are not a straightforward task. Furthermore, environmental friendliness has increased the importance of the whole transportation sector. This development will change roles inside the transportation sector. Even now, but especially in the future, decisions regarding the transportation sector will be partly based on emission levels and other externalities originating from transportation in addition to pure transportation costs. There are different factors, which could have an impact on the transportation sector. IMO’s sulphur regulation is estimated to increase the costs of short sea shipping in the Baltic Sea. Price development of energy could change the roles of different transport modes. Higher awareness of the environmental impacts originating from transportation could also have an impact on the price level of more polluting transport modes. According to earlier research, increased inland transportation, modal shift and slowsteaming can be possible results of these changes in the transportation sector. Possible changes in the transportation sector and ways to settle potential obstacles are studied in this dissertation. Furthermore, means to improve cost-efficiency and to decrease environmental impacts originating from transportation are researched. Hypothetical Finnish dry port network and Rail Baltica transport corridor are studied in this dissertation. Benefits and disadvantages are studied with different methodologies. These include gravitational models, which were optimized with linear integer programming, discrete-event and system dynamics simulation, an interview study and a case study. Geographical focus is on the Baltic Sea Region, but the results can be adapted to other geographical locations with discretion. Results indicate that the dry port concept has benefits, but optimization regarding the location and the amount of dry ports plays an important role. In addition, the utilization of dry ports for freight transportation should be carefully operated, since only a certain amount of total freight volume can be cost-efficiently transported through dry ports. If dry ports are created and located without proper planning, they could actually increase transportation costs and delivery times of the whole transportation system. With an optimized dry port network, transportation costs can be lowered in Finland with three to five dry ports. Environmental impacts can be lowered with up to nine dry ports. If more dry ports are added to the system, the benefits become very minor, i.e. payback time of investments becomes extremely long. Furthermore, dry port network could support major transport corridors such as Rail Baltica. Based on an analysis of statistics and interview study, there could be enough freight volume available for Rail Baltica, especially, if North-West Russia is part of the Northern end of the corridor. Transit traffic to and from Russia (especially through the Baltic States) plays a large role. It could be possible to increase transit traffic through Finland by connecting the potential Finnish dry port network and the studied transport corridor. Additionally, sulphur emission regulation is assumed to increase the attractiveness of Rail Baltica in the year 2015. Part of the transit traffic could be rerouted along Rail Baltica instead of the Baltic Sea, since the price level of sea transport could increase due to the sulphur regulation. Both, the hypothetical Finnish dry port network and Rail Baltica transport corridor could benefit each other. The dry port network could gain more market share from Russia, but also from Central Europe, which is the other end of Rail Baltica. In addition, further Eastern countries could also be connected to achieve higher potential freight volume by rail.

Evaluation of temperatures in a refrigerated container for chilled and frozen food transport

The objective of this work was to monitor the operational conditions of the transport of chilled and frozen foods during delivery within cities and to evaluate the impact of the door openings on the alteration of the internal temperature of the refrigerated environment. Several temperature and pressure sensors were used in a refrigerated container with two compartments and they were installed in the refrigeration system unit and on the internal and external surfaces of the container. After the monitoring tests, it was verified that door openings during deliveries resulted in a disturbance that raised the internal temperature of the refrigerated container above values recommended for adequate conservation of the products transported. Moreover, increasing the number of door openings promoted a cumulative effect on the internal temperature, mainly in the chilled food compartment of the container. It was concluded that the refrigeration system unit presented serious limitations with regard to the maintenance of the container's internal temperature during the actual distribution routine, since it does not possess enough instantaneous capacity to restore the temperature set-point between deliveries.

Influence of packaging and potassium sorbate on the physical, physicochemical and microbiological alterations of guava preserves

The elaboration of preserves through fruit processing is a promising alternative for their conservation. Such processing provides pleasant flavor due to the increase of sweetness and allows good conservation of the product for a prolonged time. Seeking quality and higher durability of fruit preserves, the purpose of this work was to evaluate the interference of potassium sorbate addition, and polypropylene, metallic and cellophane film packaging on the quality of guava (Psidium guajava L.) preserves during storage, through the physical, physiochemical and microbiological characteristics. The physical, physiochemical and microbiological analyses showed that the different types of packaging did not interfere in the stability of the guava preserves until the 5th month of storage - time being the factor that most influences the quality of the preserves when stored under temperature and humidity of 19.6 °C and 76.2%, respectively. The potassium sorbate caused an increase of the soluble solid levels and a decrease of the water activity. Regardless of the treatment, the preserves remained microbiologically stable during storage.