Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats

Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes), infarct size (percentage of the arc with infarct on 3 transverse planes), systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient). Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005). The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction) to 53.1 ± 1.5% (control) and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001) and histology (r = -0.78; P < 00001). The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7) was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3). There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats.

Foreign Direct Investment, Clean Development Mechanism, and Environmental Management: A case of Sub-Saharan Africa

This doctoral dissertation explores the contribution of environmental management practices, the so-called clean development mechanism (CDM) projects, and foreign direct investment (FDI) in achieving sustainable development in developing countries, particularly in Sub- Saharan Africa. Because the climate change caused by greenhouse gas emissions is one of the most serious global environmental challenges, the main focus is on the causal links between carbon dioxide (CO2) emissions, energy consumption, and economic development in Sub-Saharan Africa. In addition, the dissertation investigates the factors that have affected the distribution of CDM projects in developing countries and the relationships between FDI and other macroeconomic variables of interest. The main contribution of the dissertation is empirical. One of the publications uses crosssectional data and Tobit and Poisson regressions. Three of the studies use time-series data and vector autoregressive and vector error correction models, while two publications use panel data and panel data estimation methods. One of the publications uses thus both timeseries and panel data. The concept of Granger causality is utilized in four of the publications. The results indicate that there are significant differences in the Granger causality relationships between CO2 emissions, energy consumption, economic growth, and FDI in different countries. It appears also that the causality relationships change over time. Furthermore, the results support the environmental Kuznets curve hypothesis but only for some of the countries. As to CDM activities, past emission levels, institutional quality, and the size of the host country appear to be among the significant determinants of the distribution of CDM projects. FDI and exports are also found to be significant determinants of economic growth.

NMDA receptor blockade alters the intracellular distribution of neuronal nitric oxide synthase in the superficial layers of the rat superior colliculus

Nitric oxide (NO) is a molecular messenger involved in several events of synaptic plasticity in the central nervous system. Ca2+ influx through the N-methyl-D-aspartate receptor (NMDAR) triggers the synthesis of NO by activating the enzyme neuronal nitric oxide synthase (nNOS) in postsynaptic densities. Therefore, NMDAR and nNOS are part of the intricate scenario of postsynaptic densities. In the present study, we hypothesized that the intracellular distribution of nNOS in the neurons of superior colliculus (SC) superficial layers is an NMDAR activity-dependent process. We used osmotic minipumps to promote chronic blockade of the receptors with the pharmacological agent MK-801 in the SC of 7 adult rats. The effective blockade of NMDAR was assessed by changes in the protein level of the immediate early gene NGFI-A, which is a well-known NMDAR activity-dependent expressing transcription factor. Upon chronic infusion of MK-801, a decrease of 47% in the number of cells expressing NGFI-A was observed in the SC of treated animals. Additionally, the filled dendritic extent by the histochemical product of nicotinamide adenine di-nucleotide phosphate diaphorase was reduced by 45% when compared to the contralateral SC of the same animals and by 64% when compared to the SC of control animals. We conclude that the proper intracellular localization of nNOS in the retinorecipient layers of SC depends on NMDAR activation. These results are consistent with the view that the participation of NO in the physiological and plastic events of the central nervous system might be closely related to an NMDAR activity-dependent function.

Mechanical cardiac remodeling and new-onset atrial fibrillation in long-term follow-up of subjects with chronic Chagas' disease

Atrial fibrillation (AF) affects subjects with Chagas' disease and is an indicator of poor prognosis. We investigated clinical, echocardiographic and electrocardiographic variables of Chagas' disease in a long-term longitudinal study as predictors of a new-onset AF episode lasting >24 h, nonfatal embolic stroke and cardiac death. Fifty adult outpatients (34 to 74 years old, 62% females) staged according to the Los Andes classification were enrolled. During a follow-up of (mean ± SD) 84.2 ± 39.0 months, 9 subjects developed AF (incidence: 3.3 ± 1.0%/year), 5 had nonfatal stroke (incidence: 1.3 ± 1.0%/year), and nine died (mortality rate: 2.3 ± 0.8%/year). The progression rate of left ventricular mass and left ventricular ejection fraction was significantly greater in subjects who experienced AF (16.4 ± 20.0 g/year and -8.6 ± 7.6%/year, respectively) than in those who did not (8.2 ± 8.4 g/year; P = 0.03, and -3.0 ± 2.5%/year; P = 0.04, respectively). In univariate analysis, left atrial diameter ≥3.2 cm (P = 0.002), pulmonary arterial hypertension (P = 0.035), frequent premature supraventricular and ventricular contraction counts/24 h (P = 0.005 and P = 0.007, respectively), ventricular couplets/24 h (P = 0.002), and ventricular tachycardia (P = 0.004) were long-term predictors of AF. P-wave signal-averaged ECG revealed a limited long-term predictive value for AF. In chronic Chagas' disease, large left atrial diameter, pulmonary arterial hypertension, frequent supraventricular and ventricular premature beats, and ventricular tachycardia are long-term predictors of AF. The rate of left ventricular mass enlargement and systolic function deterioration impact AF incidence in this population.

Cloning, bioinformatics analysis, and expression of the dust mite allergen Der f 5 of Dermatophagoides farinae

Crude extracts of house dust mites are used clinically for diagnosis and immunotherapy of allergic diseases, including bronchial asthma, perennial rhinitis, and atopic dermatitis. However, crude extracts are complexes with non-allergenic antigens and lack effective concentrations of important allergens, resulting in several side effects. Dermatophagoides farinae (Hughes; Acari: Pyroglyphidae) is one of the predominant sources of dust mite allergens, which has more than 30 groups of allergen. The cDNA coding for the group 5 allergen of D. farinae from China was cloned, sequenced and expressed. According to alignment using the VECTOR NTI 9.0 software, there were eight mismatched nucleotides in five cDNA clones resulting in seven incompatible amino acid residues, suggesting that the Der f 5 allergen might have sequence polymorphism. Bioinformatics analysis revealed that the matured Der f 5 allergen has a molecular mass of 13604.03 Da, a theoretical pI of 5.43 and is probably hydrophobic and cytoplasmic. Similarities in amino acid sequences between Der f 5 and allergens of other domestic mite species, viz. Der p 5, Blo t 5, Sui m 5, and Lep d 5, were 79, 48, 53, and 37%, respectively. Phylogenetic analysis indicated that Der f 5 and Der p 5 clustered together. Blo t 5 and Ale o 5 also clustered together, although Blomia tropicalis and Aleuroglyphus ovatus belong to different mite families, viz. Echimyopodidae and Acaridae, respectively.

Developments in the use of nanocapsules in oncology

The application of nanotechnology to medicine can provide important benefits, especially in oncology, a fact that has resulted in the emergence of a new field called Nanooncology. Nanoparticles can be engineered to incorporate a wide variety of chemotherapeutic or diagnostic agents. A nanocapsule is a vesicular system that exhibits a typical core-shell structure in which active molecules are confined to a reservoir or within a cavity that is surrounded by a polymer membrane or coating. Delivery systems based on nanocapsules are usually transported to a targeted tumor site and then release their contents upon change in environmental conditions. An effective delivery of the therapeutic agent to the tumor site and to the infiltrating tumor cells is difficult to achieve in many cancer treatments. Therefore, new devices are being developed to facilitate intratumoral distribution, to protect the active agent from premature degradation and to allow its sustained and controlled release. This review focuses on recent studies on the use of nanocapsules for cancer therapy and diagnosis.

Development and validation of a genotype 3 recombinant protein-based immunoassay for hepatitis E virus serology in swine

Hepatitis E virus (HEV) is classified within the family Hepeviridae, genus Hepevirus. HEV genotype 3 (Gt3) infections are endemic in pigs in Western Europe and in North and South America and cause zoonotic infections in humans. Several serological assays to detect HEV antibodies in pigs have been developed, at first mainly based on HEV genotype 1 (Gt1) antigens. To develop a sensitive HEV Gt3 ELISA, a recombinant baculovirus expression product of HEV Gt3 open reading frame-2 was produced and coated onto polystyrene ELISA plates. After incubation of porcine sera, bound HEV antibodies were detected with anti-porcine anti-IgG and anti-IgM conjugates. For primary estimation of sensitivity and specificity of the assay, sets of sera were used from pigs experimentally infected with HEV Gt3. For further validation of the assay and to set the cutoff value, a batch of 1100 pig sera was used. All pig sera were tested using the developed HEV Gt3 assay and two other serologic assays based on HEV Gt1 antigens. Since there is no gold standard available for HEV antibody testing, further validation and a definite setting of the cutoff of the developed HEV Gt3 assay were performed using a statistical approach based on Bayes' theorem. The developed and validated HEV antibody assay showed effective detection of HEV-specific antibodies. This assay can contribute to an improved detection of HEV antibodies and enable more reliable estimates of the prevalence of HEV Gt3 in swine in different regions.

Show me your brain! Stories of interdisciplinary knowledge creation in practice. Experiences and observations from Aalto Design Factory, Finland.

This dissertation centres on the themes of knowledge creation, interdisciplinarity and knowledge work. My research approaches interdisciplinary knowledge creation (IKC) as practical situated activity. I argue that by approaching IKC from the practice-based perspective makes it possible to “deconstruct” how knowledge creation actually happens, and demystify its strong intellectual, mentalistic and expertise-based connotations. I have rendered the work of the observed knowledge workers into something ordinary, accessible and routinized. Consequently this has made it possible to grasp the pragmatic challenges as well the concrete drivers of such activity. Thus the effective way of organizing such activities becomes a question of organizing and leading effective everyday practices. To achieve that end, I have conducted ethnographic research of one explicitly interdisciplinary space within higher education, Aalto Design Factory in Helsinki, Finland, where I observed how students from different disciplines collaborated in new product development projects. I argue that IKC is a multi-dimensional construct that intertwines a particular way of doing; a way of experiencing; a way of embodied being; and a way of reflecting on the very doing itself. This places emphasis not only the practices themselves, but also on the way the individual experiences the practices, as this directly affects how the individual practices. My findings suggest that in order to effectively organize and execute knowledge creation activities organizations need to better accept and manage the emergent diversity and complexity inherent in such activities. In order to accomplish this, I highlight the importance of understanding and using a variety of (material) objects, the centrality of mundane everyday practices, the acceptance of contradictions and negotiations well as the role of management that is involved and engaged. To succeed in interdisciplinary knowledge creation is to lead not only by example, but also by being very much present in the very everyday practices that make it happen.

Effect of osmotic predehydration on drying characteristics of banana fruits

Osmotic dehydration is considered to be a suitable preprocessing step to reduce the water content of foods. Such products can be dried further by conventional drying processes to lower their water activity and thus extend their shelf life. In this work, banana (Musa sapientum) fruits were initially treated by osmosis by varying several parameters of the processing conditions which included, besides the cutting format (longitudinal and round slices) of the fruit, temperature (28 and 49 ºC), syrup concentration (50, 60 and 67 ºBrix), treatment time (2, 4, 6, 10, 14, 16 and 18 hours), fruit and syrup ratio (1:1, 1:2, 1:3 and 1:4) and agitation effects. The best quality products were obtained by the use of the 67 ºBrix syrup, for 60 minutes of osmotic treatment, at 28 ºC, having a fruit and syrup ratio of 1:1 and agitation. The experimental data obtained on reduction in moisture content during the osmotic treatment were correlated with the experimental equation of M/Mo = Ae(-Kt), where A and K are the constants which represent the geometry and effective diffusivity of the drying process. This simplified mathematical model correlated well with the experimental results.

Production and characterization of lipid microparticles produced by spray cooling encapsulating a low molar mass hydrophilic compound

The objective of this research was to produce and characterize lipid particles (MpLs) that may be used as carriers of high amounts of hydrophilic core and evaluate the influence of the core amount on the performance of lipid microparticles. The MpLs were produced by spray cooling from solid and liquid lipid mixtures (stearic and oleic fatty acids and partly hydrogenated vegetable fat) containing glucose solution as core and soy lecithin as surfactant. The performance of MpLs was evaluated by means of the effective amount of encapsulated core, the core amount present on the surface of MpLs (superficial glucose) and the core release profile in aqueous solution. Morphological observations showed that MpLs presented spherical shape and a rugged and continuous surface, and an average diameter between 25 and 32 µm. The effective amount of encapsulated core was greater than 78% for all formulations evaluated. Larger amounts of superficial glucose were found in formulations in which more concentrated glucose solutions were used, regardless of the glucose lipid-solution ratio. The release results showed that core retention was significantly influenced by the glucose solution concentration, whereas release modulation was influenced by the glucose lipid-solution ratio.

Clinical and pathological correlations of C4d immunostaining and its infl uence on the outcome of kidney transplant recipients

INTRODUCTION: C4d is a marker of antibody-mediated rejection (ABMR) in kidney allografts, although cellular rejection also have C4d deposits. OBJECTIVE: To correlate C4d expression with clinico-pathological parameters and graft outcomes at three years. METHODS: One hundred forty six renal transplantation recipients with graft biopsies by indication were included. C4d staining was performed by paraffin-immunohistochemistry. Graft function and survival were measured, and predictive variables of the outcome were determined by multivariate Cox regression. RESULTS: C4d staining was detected in 48 (31%) biopsies, of which 23 (14.7%) had diffuse and 25 (16%) focal distribution. Pre-transplantation panel reactive antibodies (%PRA) class I and II were significantly higher in C4d positive patients as compared to those C4d negative. Both glomerulitis and pericapillaritis were associated to C4d (p = 0.002 and p < 0.001, respectively). The presence of C4d in biopsies diagnosed as no rejection (NR), acute cellular rejection (ACR) or interstitial fibrosis/ tubular atrophy (IF/TA) did not impact graft function or survival. Compared to NR, ACR and IF/TA C4d-, patients with ABMR C4d+ had the worst graft survival over 3 years (p = 0.034), but there was no difference between ABMR versus NR, ACR and IF/TA that were C4d positive (p = 0.10). In Cox regression, graft function at biopsy and high %PRA levels were predictors of graft loss. CONCLUSIONS: This study confirmed that C4d staining in kidney graft biopsies is a clinically useful marker of ABMR, with well defined clinical and pathological correlations. The impact of C4d deposition in other histologic diagnoses deserves further investigation.

A modified nominal stress method for fatigue assessment of steel plates with thermally cut edges

Thermal cutting methods, are commonly used in the manufacture of metal parts. Thermal cutting processes separate materials by using heat. The process can be done with or without a stream of cutting oxygen. Common processes are Oxygen, plasma and laser cutting. It depends on the application and material which cutting method is used. Numerically-controlled thermal cutting is a cost-effective way of prefabricating components. One design aim is to minimize the number of work steps in order to increase competitiveness. This has resulted in the holes and openings in plate parts manufactured today being made using thermal cutting methods. This is a problem from the fatigue life perspective because there is local detail in the as-welded state that causes a rise in stress in a local area of the plate. In a case where the static utilization of a net section is full used, the calculated linear local stresses and stress ranges are often over 2 times the material yield strength. The shakedown criteria are exceeded. Fatigue life assessment of flame-cut details is commonly based on the nominal stress method. For welded details, design standards and instructions provide more accurate and flexible methods, e.g. a hot-spot method, but these methods are not universally applied to flame cut edges. Some of the fatigue tests of flame cut edges in the laboratory indicated that fatigue life estimations based on the standard nominal stress method can give quite a conservative fatigue life estimate in cases where a high notch factor was present. This is an undesirable phenomenon and it limits the potential for minimizing structure size and total costs. A new calculation method is introduced to improve the accuracy of the theoretical fatigue life prediction method of a flame cut edge with a high stress concentration factor. Simple equations were derived by using laboratory fatigue test results, which are published in this work. The proposed method is called the modified FAT method (FATmod). The method takes into account the residual stress state, surface quality, material strength class and true stress ratio in the critical place.

Press forming of paperboard – advancement of converting tools and process control

Press forming is nowadays one of the most common industrial methods in use for producing deeper trays from paperboard. Demands for material properties like recyclability and sustainability have increased also in the packaging industry, but there are still limitations related to the formability of paperboard. A majority of recent studies have focused on material development, but the potential of the package manufacturing process can also be improved by the development of tooling and process control. In this study, advanced converting tools (die cutting tools and the press forming mould) are created for production scale paperboard tray manufacturing. Also monitoring methods that enable the production of paperboard trays with enhanced quality, and can be utilized in process control are developed. The principles for tray blank preparation, including creasing pattern and die cutting tool design are introduced. The mould heating arrangement and determination of mould clearance are investigated to improve the quality of the press formed trays. The effect of the spring back of the tray walls on the tray dimensions can be managed by adjusting the heat-related process parameters and estimating it at the mould design stage. This enables production speed optimization as the process parameters can be adjusted more freely. Real-time monitoring of pressing force by using multiple force sensors embedded in the mould structure can be utilized in the evaluation of material characteristics on a modified production machinery. Comprehensive process control can be achieved with a combination of measurement of the outer dimensions of the trays and pressing force monitoring. The control method enables detection of defects and tracking changes in the material properties. The optimized converting tools provide a basis for effective operation of the control system.

Physiological maturity of seeds and colorimetry of fruits of Jatropha curcas L.

The objective was to relate the coloration of fruits of Jatropha curcas L during the maturation process with morphometric (fruits and seeds) and germinative characteristics (seeds). Fruits were collected at various maturation stages from mast trees located in Eldorado/MS, and six maturation stages were visually classified based on fruit's epicarp color. Epicarp digital colorimetry was used to characterize maturation stages in addition to morphometric variables of length and width of fruits and seeds, as well their water content. For determining the physiological potential it was used germination test, emergence velocity index and first count of germination. Results indicated that seeds of J. curcas should be harvested when fruit epicarp shows a reading equal or smaller than 82, 70 or 65 nm of red, green or blue scales from a digital color analyzer. Seeds of fruits with that colorimetry can be harvested in virtue of the maxim acumululation of dry mass, water content below 38,5% and higher physiological potential.

Investigating the Existence of Business-IT Alignment Trap in Finnish IT Organizations

The overall purpose of this master's thesis is to investigate the existence of business-IT alignment trap in Finnish IT organizations. The alignment trap refers to the inability of IT investments to deliver the expected business benefits. The basis for this investigation is due to the previous knowledge that high level of IT alignment practice with very low efficacy in an organization can lead to alignment trap. The theory which was established on the dimensions of IT-alignment and efficacy of IT as a whole with considerations for cost reduction and revenue growth benefits. This study explored the same dimensions with the previous study but identified additional benefit (profitability). The study was conducted using the Finnish IT barometer data from different IT organizations. A quantitative research method was used in conducting this study which was built on positivist philosophical stance. The empirical data is based on survey data, an excerpt from the Finnish IT barometer data that captured the annual survey results of IT significance to Finnish organizations as evaluated by business and IT professionals. The survey data comprised of 249 respondents and their responses were categorized into high and low IT intensive which form the basis of the statistical analysis conducted. Overall, five analyses were conducted using the variables of cost reductions, revenue growth and profitability in the 2x2 matrix dimensions of IT alignment and efficacy of IT, grouped into alignment trap, maintenance zone, well-oiled IT and IT-enabled growth. The empirical results, revealed a partial existence of alignment trap in Finnish IT organizations. This is due to a very minute number of organizations that were ensnared in the alignment trap zone on the analyses conducted. Although they recorded considerable high performances in terms of revenue growth rate with IT spending below the average companies, their profitability was considered very low. Generally it was observed that Finnish IT organizations with high efficacy of IT practices had good performances, while those with low efficacy of IT experienced low performances, especially in the aspect of profitability, regardless of the degree of IT alignment. The study proposes that organizations should improve on practices that enhance effectiveness of IT more in order for them to realize the full benefits of IT and to avoid alignment trap.