10 research outputs found
The Importance of the Study of the Hemodynamics of the Uterine Tumors by the Method of Dopplerometry in the Two- and Three-dimensional Echography Modes for Differential Diagnostics of Simple, Proliferating Leiomyomas and Uterine Sarcomas (Review of Litera
The article analyzes modern literature data on the importance of studying the hemodynamics of uterine tumors with dopplerometry in two - and three - dimensional regimens of echography for differential diagnosis of simple proliferating leiomyomas and sarcomas of the uterus. It is shown that the differential diagnosis of benign and Malignant tumors using the dopplerometry is based on various features of the blood supply of these tumors. On the basis of the analysis of literature data, it was concluded that in the dopplerometry evaluation of benign, borderline and Malignant tumors of myometrium in the two-dimensional regime, there were differences in the localization of the detected vessels in the CDM regimen, in the rates of vascular blood flow and vascular resistance in pulse dopplerometry. For a simple leiomyoma, the absence of a central intra-node localization of blood vessels in the CDM regimen, a low rate of arterial and venous blood flow, as well as an average resistance of arterial blood flow in the regime of impulsive dopplerometry are most typical; in a leiomyoma with eating disorders, the absence of a central intra-node localization of blood vessels, a low rate of arterial and venous blood flow in combination with high arterial resistance were more often observed. For the proliferating leiomyoma, the central intra-node localization of the vessels and the average blood flow velocities with low and medium resistance are characteristic. For sarcoma of the uterus, there is abundant vascularization both around the periphery and in the center, high blood flow rates and low resistance. The authors emphasize that there is information about the low specificity of this gradation, since the detection of a central type of vascularization and low resistance values can be in simple myomatous nodes with edema, eating disorders and destruction, and leads to diagnostic errors and suspicion of Malignancy. In the three-dimensional dopplerometry mode for simple leiomyomas, low indices of volume perfusion indices were characteristic, and for proliferating leiomyomas and sarcomas of the uterus – high indices of volume perfusion indices exceeding those in the uterus as a whole.Based on the review of the literature, the authors concluded that the presently available echographic and dopplerometric two- and three-dimensional markers are characterized by high sensitivity, but very low specificity. The low specificity of the known ultrasonic and dopplerometric criteria combined with the rarity of cases of sarcoma in the uterus against the background of a large number of similar echographically and dopplerometrically leiomyomas lead to low diagnostic accuracy of ultrasound diagnostics. This situation requires a further continuation of the scientific search for differential diagnostic ultrasound criteria by leiomyomas and sarcomas of the uterus using modern technologies, including three-dimensional echography
Study of Hemodynamics of the Uterine Body by the Method of Three-dimensional Energy Dopplerography of Patients with Leiomyoma in Different Age Periods
To date, there is not enough papers to establish the reproducibility of the calculation of three-dimensional indices of blood flow and their threshold values for the diagnosis of a particular pathology. In this regard, the technique of three-dimensional Doppler sonography requires further study.The aim of research is studying the hemodynamics of the uterine body of patients with leiomyoma by three-dimensional energy Doppler ultrasonography to determine the possible patterns of changes in the indicators of three-dimensional vascularization indices depending on the phases of the menstrual cycle of women of reproductive age, in perimenopause and at different periods of menopause.Materials and methods. 326 women between the ages of 18 and 75 were surveyed (Me = 46.5). The comparison group consisted of 157 (48.15 %) healthy women, the main group was 169 women (51.84 %) with uterine leiomyoma. All patients in both groups were divided into women of reproductive age, women in peri - and menopause.In 3D reconstruction of the uterus using the energy mapping function and the VOCAL (Virtual Organ Computer - aided Analysis) option, an objective assessment of the hemodynamics of the uterine body was performed by calculating the vascularization index (VI), which characterizes the percentage of colour voxels in uterus body volume, flow intensity index (FI), showing the median luminance of colour voxels, which depends on the blood flow velocity in a given three-dimensional volume and vascularization-flow index (VFI), which is a product of multiplying the vascularization index and the flow index, divided by 100.Result. As a result, the main group identified the patterns of dynamics of three-dimensional indices of blood flow, depending on the survey at different ages, similar to the comparison group. In the reproductive period in patients with uterine leiomyoma, regardless of the size and degree of vascularization, the minimum values of the indexes VI, FI and VFI of the body of the uterus were registered in the early proliferative phase, significantly increasing to the middle secretion phase, coinciding with the fertility period of corpus luteum, secretion (p <0.05, CCU). In peri - and menopause, patients with leiomyomas have a statistically significant dynamics, similar to the nomograms of the comparison group, in reducing the values of the three-dimensional index of perfusion of the VI of the uterus as the period of absence of menstruation increases (CCU, p = 0.0472), with the highest values being characteristic of the perimenopause period. In the analysis of the dynamics of the FI and VFI indices of the body of the uterus of women with perio- and menopausal leiomyomas, the distribution of the studied indices was not confirmed by statistical significance. However, their pattern quite accurately reproduces the dynamics of a gradual decrease in these three-dimensional indices of blood flow in women with uterine body leiomyoma as the duration of absence of menstruation increases: the highest values were characteristic of the perimenopause period and the lowest - for the menopause period of more than 10 years.Conclusions. Taking into account the revealed patterns of dynamics of indicators of three-dimensional indices of blood flow depending on the age periods of women with leiomyoma will in the future increase the sensitivity and specificity of the method of three-dimensional energy Doppler sonography in the differential diagnosis of proliferative activity of uterine leiomyom
Evolution of the Sabin Vaccine into Pathogenic Derivatives without Appreciable Changes in Antigenic Properties: Need for Improvement of Current Poliovirus Surveillanceâ–ż
The Sabin oral polio vaccine (OPV) may evolve into pathogenic viruses, causing sporadic cases and outbreaks of poliomyelitis. Such vaccine-derived polioviruses (VDPV) generally exhibit altered antigenicity. The current paradigm to distinguish VDPV from OPV and wild polioviruses is to characterize primarily those poliovirus isolates that demonstrate deviations from OPV in antigenic and genetic intratypic differentiation (ITD) tests. Here we report on two independent cases of poliomyelitis caused by VDPVs with “Sabin-like” properties in several ITD assays. The results suggest the existence of diverse pathways of OPV evolution and necessitate improvement of poliovirus surveillance, which currently potentially misses this class of VDPV
Antigenic Evolution of Vaccine-Derived Polioviruses: Changes in Individual Epitopes and Relative Stability of the Overall Immunological Properties
The Sabin oral poliovirus vaccine (OPV) readily undergoes changes in antigenic sites upon replication in humans. Here, a set of antigenically altered descendants of the three OPV serotypes (76 isolates) was characterized to determine the driving forces behind these changes and their biological implications. The amino acid residues of OPV derivatives that lie within or close to the known antigenic sites exhibited a marked tendency to be replaced by residues characteristic of homotypic wild polioviruses, and these changes may occur very early in OPV evolution. The specific amino acid alterations nicely correlated with serotype-specific changes in the reactivity of certain individual antigenic sites, as revealed by the recently devised monoclonal antibody-based enzyme-linked immunosorbent assay. In comparison to the original vaccine, small changes, if any, in the neutralizing capacity of human or rabbit sera were observed in highly diverged vaccine polioviruses of three serotypes, in spite of strong alterations of certain epitopes. We propose that the common antigenic alterations in evolving OPV strains largely reflect attempts to eliminate fitness-decreasing mutations acquired either during the original selection of the vaccine or already present in the parental strains. Variability of individual epitopes does not appear to be primarily caused by, or lead to, a significant immune evasion, enhancing only slightly, if at all, the capacity of OPV derivatives to overcome immunity in human populations. This study reveals some important patterns of poliovirus evolution and has obvious implications for the rational design of live viral vaccines
Recent progress in L-H transition studies at JET: Tritium, Helium, Hydrogen and Deuterium
We present an overview of results from a series of L-II transition experiments undertaken at JET since the installation of the ITER-like-wall (JET-ILW), with beryllium wall tiles and a tungsten divertor. Tritium, helium and deuterium plasmas have been investigated. Initial results in tritium show ohmic L-H transitions at low density and the power threshold for the L-H transition (P-LH) is lower in tritium plasmas than in deuterium ones at low densities, while we still lack contrasted data to provide a scaling at high densities. In helium plasmas there is a notable shift of the density at which the power threshold is minimum ((n) over bar (e,min)) to higher values relative to deuterium and hydrogen references. Above (n) over bar (e,min) (He) the L-H power threshold at high densities is similar for D and He plasmas. Transport modelling in slab geometry shows that in helium neoclassical transport competes with interchange-driven transport, unlike in hydrogen isotopes. Measurements of the radial electric field in deuterium plasmas show that E-r shear is not a good indicator of proximity to the L-H transition. Transport analysis of ion heat flux in deuterium plasmas show a non-linearity as density is decreased below (n) over bar (e,min). Lastly, a regression of the JET-ILW deuterium data is compared to the 2008 ITPA scaling law