17 research outputs found
A new approach to fetal echocardiography: digital casts of the fetal cardiac chambers and great vessels for detection of congenital heart disease
OBJECTIVE: The purpose of this study was to describe a method of 4-dimensional (4D) reconstruction of the cardiac chambers and outflow tracts using a combination of spatiotemporal image correlation, "inversion mode," and "B-flow" imaging. METHODS: Spatiotemporal image correlation and the inversion mode were used in the examination of the volume data sets of 23 fetuses with congenital heart anomalies. A subset was also examined with B-flow imaging using the gradient light algorithm. Digital reconstructions from abnormal hearts were compared with a library obtained from fetuses without abnormalities. RESULTS: Rendered images of the 4-chamber view using the inversion mode were characterized by: (1) echogenic chambers; (2) sharp delineation of chamber contours when compared with 2-dimensional (2D) images; and (3) distinct display of the myocardium, interventricular septum, interatrial septum, and mitral and tricuspid valves as anechoic structures. Ventricular septal defects, abnormal differential insertion of the atrioventricular valves, and valve atresia were well visualized with the inversion mode. The application of inversion mode or B-flow imaging to 4D rendering of the outflow tracts resulted in "digital casts" displaying the spatial relationships between the outflow tracts as well as the connections between the great arteries and ventricular chambers. The spatial relationships and communications among cardiac structures cannot be visualized with conventional 2D ultrasonography. CONCLUSIONS: The application of spatiotemporal image correlation, inversion mode, and B-flow imaging generates information about the anatomy and pathologic characteristics of the fetal heart (digital casts) that cannot be obtained with 2D fetal echocardiography. We propose that these modalities enhance the information provided by ultrasonographic interrogation of the fetal heart and will improve prenatal diagnosis
Variations in TcdB Activity and the Hypervirulence of Emerging Strains of Clostridium difficile
Hypervirulent strains of Clostridium difficile have emerged over the past decade, increasing the morbidity and mortality of patients infected by this opportunistic pathogen. Recent work suggested the major C. difficile virulence factor, TcdB, from hypervirulent strains (TcdBHV) was more cytotoxic in vitro than TcdB from historical strains (TcdBHIST). The current study investigated the in vivo impact of altered TcdB tropism, and the underlying mechanism responsible for the differences in activity between the two forms of this toxin. A combination of protein sequence analyses, in vivo studies using a Danio rerio model system, and cell entry combined with fluorescence assays were used to define the critical differences between TcdBHV and TcdBHIST. Sequence analysis found that TcdB was the most variable protein expressed from the pathogenicity locus of C. difficile. In line with these sequence differences, the in vivo effects of TcdBHV were found to be substantially broader and more pronounced than those caused by TcdBHIST. The increased toxicity of TcdBHV was related to the toxin's ability to enter cells more rapidly and at an earlier stage in endocytosis than TcdBHIST. The underlying biochemical mechanism for more rapid cell entry was identified in experiments demonstrating that TcdBHV undergoes acid-induced conformational changes at a pH much higher than that of TcdBHIST. Such pH-related conformational changes are known to be the inciting step in membrane insertion and translocation for TcdB. These data provide insight into a critical change in TcdB activity that contributes to the emerging hypervirulence of C. difficile
Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine
[This corrects the article DOI: 10.1186/s13054-016-1208-6.]
Three-dimensional color power imaging of the fetal hepatic circulation
Objective
The purpose of this study was to describe the use of three-dimensional power Doppler ultrasonography to identify vascular congenital anomalies of fetal portosystemic and umbilical venous systems.Study design
In a prospective study, the hepatic and umbilical venous systems were examined in 390 fetuses with two-dimensional ultrasonography, color, and spectral Doppler imaging. Fetuses suspected to have anomalies of the portal system and ductus venosus were additionally examined with three-dimensional power Doppler ultrasonography.Results
Vascular anomalies were identified in 8 fetuses (absent ductus venosus, n = 4; direct connection between the umbilical vein and the right atrium, n = 2; and direct connection between the umbilical vein and the inferior vena cava, n = 2) out of the 310 in which the venous system could be adequately imaged (prevalence = 2.6%). Three-dimensional power Doppler imaging showed the course of the umbilical vein, its relationship to the portosystemic circulation, and whether a ductus venosus was present.Conclusion
Three-dimensional power Doppler ultrasonography can be used to image normal fetal hepatic and portal circulation, as well as identify anomalies of the fetal portosystemic and umbilical venous systems. <br/
Maternal plasma osteoprotegerin concentration in normal pregnancy
OBJECTIVE: Pregnancy is associated with major changes in calcium metabolism because the neonatal skeleton contains approximately 30 g of calcium, which are largely deposited in the third trimester. Osteoprotegerin (OPG) acts as a decoy receptor for the "Receptor Activator of Nuclear Factor-kappaB Ligand" (RANKL), which is an essential factor for bone remodeling. This study was conducted to determine whether there were changes in maternal plasma OPG concentration during normal pregnancy. STUDY DESIGN: A cross-sectional study was performed in 433 patients of reproductive age (40 nonpregnant and 393 pregnant). Pregnant patients were classified into 4 groups according to gestational age: group 1: 11 to 14 weeks (n = 100); group 2: 15 to 18 weeks (n = 99); group 3: 27 to 30 weeks (n = 100); and group 4: 37 to 42 weeks (n = 94). Plasma OPG concentrations were measured with the use of a sensitive and specific immunoassay. Nonparametric statistics were used for analysis. RESULTS: OPG was detected in the plasma of all women tested. The median OPG concentration was significantly higher in term patients than in those in early pregnancy (median: 6.63 pmol/L [range: 1.57-25.57] vs median: 3.98 pmol/L [range: 0.41-13.71], P < .001). There was no significant difference in plasma OPG concentrations between nonpregnant women and those in groups 1 or 2 (nonpregnant women median: 3.86 pmol/L [range: 1.64-15.29] vs group 1 median: 3.98 pmol/L [range: 0.41-13.71] vs group 2 median: 3.87 pmol/L [range: 1.14-69.83], P = .75). CONCLUSION: The median maternal plasma OPG concentration is higher in the third trimester than in the first trimester of pregnancy. OPG may be involved in the regulation of bone turnover during pregnancy
Comparative metabolomic profiling reveals that dysregulated glycolysis stemming from lack of salvage NAD⁺ biosynthesis impairs reproductive development in Caenorhabditis elegans
Temporal developmental progression is highly coordinated in Caenorhabditis elegans. However, loss of nicotinamidase PNC-1 activity slows reproductive development, uncoupling it from its typical progression relative to the soma. Using LC/MS we demonstrate that pnc-1 mutants do not salvage the nicotinamide released by NAD(+) consumers to resynthesize NAD(+), resulting in a reduction in global NAD(+) bioavailability. We manipulate NAD(+) levels to demonstrate that a minor deficit in NAD(+) availability is incompatible with a normal pace of gonad development. The NAD(+) deficit compromises NAD(+) consumer activity, but we surprisingly found no functional link between consumer activity and reproductive development. As a result we turned to a comparative metabolomics approach to identify the cause of the developmental phenotype. We reveal widespread metabolic perturbations, and using complementary pharmacological and genetic approaches, we demonstrate that a glycolytic block accounts for the slow pace of reproductive development. Interestingly, mitochondria are protected from both the deficiency in NAD(+) biosynthesis and the effects of reduced glycolytic output. We suggest that compensatory metabolic processes that maintain mitochondrial activity in the absence of efficient glycolysis are incompatible with the requirements for reproductive development, which requires high levels of cell division. In addition to demonstrating metabolic requirements for reproductive development, this work also has implications for understanding the mechanisms behind therapeutic interventions that target NAD(+) salvage biosynthesis for the purposes of inhibiting tumor growth
Henkilöstön vaihtuvuus ja siihen liittyvät tekijät telemarkkinointialalla : case: Gainer Oy
Tämä opinnäytetyö toteutettiin toimeksiantosopimuksena Gainer Oy:lle, joka on toiminut telemarkkinoinnin alalla jo vuodesta 1984. Opinnäytetyön tutkimusstrategiaksi valittiin case study eli tapaustutkimus. Käytimme tutkimusmenetelmänä kvalitatiivista eli laadullista tutkimusta.
Tavoitteenamme oli tutkia ja selvittää henkilöstön vaihtuvuutta ja siihen liittyviä tekijöitä alalla, jossa henkilöstön vaihtuvuus koetaan ongelmaksi.
Teoriaosuudessa käsittelemme teoreettisen viitekehyksen liittyen työnantajan keinoihin vaikuttaa työntekijän sitouttamiseen. Tämä on jaettu kahteen osa-alueeseen, jotka ovat rekrytointi sekä työhyvinvointi ja osaamisen kehittäminen.
Empiirisessä osiossa päädyimme käyttämään puolistrukturoitua teemahaastattelua, joka toteutettiin suurimmaksi osaksi puhelimitse sekä muutama haastattelu tehtiin kasvotusten. Teemahaastattelu valikoitui parhaimmaksi menetelmäksi johtuen aiheen moniulotteisuudesta. Avoimella haastattelulla emme olisi välttämättä saaneet merkittävää tietoa samassa mittakaavassa kuin puolistrukturoidulla mallilla.
Opinnäytetyön tuloksena päädyimme esittämään toimeksiantajalle muutamia kehitysehdotuksia. Haastatteluista johdetuilla päätelmillä saatettaisiin parantaa rekrytoinnin onnistumista, joka osaltaan parantaa kannattavuutta niin tuloksellisesti, kuin henkilöstön resurssejakin säästäen. Kehitysehdotuksia muodostui myös muihin osa-alueisiin liittyen. Näillä on myös vaikutusta henkilöstön yleiseen työhyvinvointiin ja työssä jaksamiseen.This thesis was carried out as a commission agreement for Gainer Oy, which has operated in the field of telemarketing since 1984. Our study was carried out as a case study using qualitative approach as our research method. Our objective was to study personnel turnover and matters relating to it in a field where personnel turnover is seen as a problem.
In the theoretical section of the study we deal with the theoretical frame of reference related to the employer's means to influence employee engagement. This is divided into two sections that are recruiting, and occupational health and development of skills.
In the empirical part of our study, we ended up using half-structured theme interviews, which were mainly carried out by telephone. A few interviews were carried out face-to-face. Theme interview was selected to be the best method because of the multidimensionality of the subject. By using open interviews, we would not necessarily have received as much significant information as by using the half-structured model.
As a result of our study, we presented a few development proposals for our client/commissioner. The conclusions drawn from the interviews may lead to more successful recruiting, which in turn improves viability both in terms of productivity and by saving the resources of the personnel. There were also other development proposals concerning other areas. The results of the study may also help to improve the general well-being at work and coping with one’s workload