scholarly journals Serologically Weak D-phenotype: Review and Interpretation of Blood Group RhD

2020 ◽  
Vol 5 (5) ◽  
pp. 45-52
Author(s):  
R. P. Pavliuk ◽  
Keyword(s):  
Pregnant Women ◽  
Accurate Determination ◽  
Clinical Importance ◽  
Scientific Justification ◽  
Serological Studies ◽  
International Laboratory ◽  
Complete Set ◽  
Polymerase Chain ◽  
D Antigen

The Rhesus system is the second most important erythrocyte system for transfusion after ABO. Accurate determination of the Rhesus status of the donor, recipient, pregnant allows to prevent the development of post-transfusion hemolytic complications of the fetus or newborn associated with incompatibility of the blood of the mother and the fetus by D antigen. Generally, determination of the Rhesus affiliation of a person is performed by serological methods using anti-Rhesus reagents with full or incomplete antibodies. However, the results of serological studies are not always clear. Mutations and other effects of the RH gene locus disrupt the production of the normal D antigen and lead to the emergence of numerous varieties of antigen D. The variant of antigen D was described in 1946 and was designated as Du. The study showed that the differences between Du antigen and normal D were quantitative rather than qualitative. The Du antigen was later designated as Dweak - a weak D-antigen or a weak D-phenotype. In the early 1950s, anti-D antibodies were detected in recipients with a weak D-antigen after transfusion with Rh-positive blood and in pregnant women with the Du phenotype during pregnancy and at the birth of a D+ baby. It was suggested that the D antigen was not homogeneous and consisted of numerous partial variants: D1, D2, D3, etc. A complete set of partial variants corresponds to a complete D-antigen. The absence of any of one or more partial factors leads to the appearance of attenuated forms of the D antigen, denoted as Dpartial. People lacking certain partial antigens can produce anti-D antibodies against them. Differentiation of weak D phenotypes has great clinical importance, because transfusion of Rh-erythrocytes to recipients with Dweak and who are actually Rh-positive, has no scientific justification and leads to unjustified consumption of deficient blood and unnecessary immunoprophylaxis of anti-Rh immunoglobulin to pregnant women. International laboratory practice has no unified policy regarding the diagnosis of weak variants of D antigen and the interpretation of the results. Polymerase chain reaction allows to accurately define the Rh status of an individual and to avoid unreasonable transfusions of Rh-negative blood and unnecessary immunoprophylaxis

The Frequency and Clinical Significance of Twin Gestations According to Zygosity and Chorionicity

2010 ◽  
Vol 13 (6) ◽  
pp. 609-619 ◽  
Author(s):  
Kyung A. Lee ◽  
Kyung Joon Oh ◽  
Seung Mi Lee ◽  
Ahm Kim ◽  
Jong Kwan Jun
Keyword(s):  
Clinical Significance ◽  
Dna Analysis ◽  
Perinatal Death ◽  
Molecular Genetic ◽  
Accurate Determination ◽  
Clinical Importance ◽  
University Hospital ◽  
Dna Analyses ◽  
Mz Twins

Background:Although the clinical importance of chorionicity in twin pregnancies has been studied widely, the significance of perinatal determination of zygosity using molecular genetic analyses remains controversial. The purpose of this study was to determine the frequency and clinical significance of twin gestations according to zygosity and chorionicity in a Korean population.Methods:We enrolled 569 women who delivered twin newborns (> 24 weeks) at Seoul National University Hospital between 1999 and 2008. Chorionicity was established by histologic examination of placentae. Zygosity was determined with sex of neonates, chorionicity, and DNA analysis of umbilical cord blood.Results:The frequency of dizygotic (DZ) twins was 71.0% (404/569 pairs) based on the opposite sex (238/404 [58.9%]) and DNA analyses (166/404 [41.1%]); that of monozygotic (MZ) twins was 29.0% (165/569), including monochorionic (MC) (72.1% [119/165]) and dichorionic (DC) twins (27.9% [46/165]), which was confirmed by DNA analyses. Among spontaneously conceived twins, the frequency of MZ twins was more than twice that of DZ twins. The risk of low birth weight was 1.8-fold higher among MZDC twins and 1.9-fold higher among MZMC twins than among DZDC twins (p< .05). Bronchopulmonary dysplasia occurred more frequently among MZMC twins than among DZDC twins (adjusted OR 8.42, 95% CI 1.82–39.08,p< .01). However, the frequencies of other neonatal morbidities were not significantly higher in the MZMC group than in the MZDC and DZDC groups. The perinatal mortality rate was 15 per 1000 total births in the DZDC twins, 20 per 1000 total births in the MZDC and 56 per 1000 total births in the MZMC (p< .01).Conclusions:Although monozygosity was shown to be a risk factor for perinatal death and accurate determination of zygosity plays a great role in the future consideration of organ transplantation and twin studies, the value of zygosity determination along with chorionicity in relation to overall neonatal morbidity was not definite.

Rapid and accurate determination of the potency of varicella vaccine by quantitative polymerase chain reaction

Vaccine ◽  
2011 ◽  
Vol 29 (47) ◽  
pp. 8490-8495 ◽  
Author(s):  
Marsha S. Russell ◽  
Changgui Li ◽  
Louise Larocque ◽  
Junzhi Wang ◽  
Aaron Farnsworth ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Quantitative Polymerase Chain Reaction ◽  
Accurate Determination ◽  
Varicella Vaccine ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Clinical Usefulness of Bioavailable Vitamin D and Impact of GC Genotyping on the Determination of Bioavailable Vitamin D in a Korean Population

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Hyun-Young Kim ◽  
Jin Hyun Kim ◽  
Myeong Hee Jung ◽  
In Ae Cho ◽  
Youngjin Kim ◽  
...  
Keyword(s):  
Vitamin D ◽  
Pregnant Women ◽  
Accurate Determination ◽  
Laboratory Data ◽  
Korean Population ◽  
Healthy Controls ◽  
Vitamin D Status ◽  
Gene Encoding ◽  
Bioavailable Vitamin D

Background. Bioavailable 25-hydroxy vitamin D (25(OH)D) has been suggested for the accurate determination of vitamin D status. The purpose of this study was to determine the utility of bioavailable 25(OH)D in assessing vitamin D status when vitamin D-binding protein (VDBP) was significantly altered by pregnancy and liver cirrhosis (LC). The role of genotyping of GC, a gene encoding VDBP, in the determination of bioavailable 25(OH)D concentration in a Korean population was also evaluated. Methods. This prospective study enrolled a total of 136 subjects (53 healthy controls, 45 patients with LC, and 38 pregnant women) from 2017 to 2018. The concentrations of total 25(OH)D and VDBP were measured, and bioavailable 25(OH)D concentrations were calculated. GC genotyping was performed to determine rs4588 and rs7041 polymorphisms. Clinical and laboratory data were compared among the three groups of subjects. Results. Median VDBP and total 25(OH)D concentrations were 165.2 μg/ml and 18.5 ng/ml in healthy controls, 76.9 μg/ml and 10.5 ng/ml in patients with LC, and 368.9 μg/ml and 17.7 ng/ml in pregnant women, respectively. Compared with controls, patients diagnosed with LC had significantly lower VDBP and total 25(OH)D concentrations (all P<0.001) while pregnant women had significantly higher VDBP concentrations (P<0.001). Although total 25(OH)D concentrations in pregnant women were similar to those in controls (P=0.394), their bioavailable 25(OH)D concentrations were significantly lower (1.2 vs. 3.0 ng/ml; P<0.001). Among all the three groups combined, the genotype-specific bioavailable 25(OH)D and the genotype-independent bioavailable 25(OH)D concentrations did not differ significantly (P=0.299). Conclusions. Our study has demonstrated that bioavailable 25(OH)D concentration reflects vitamin D status more accurately than the total 25(OH)D concentration, especially in pregnant women. In addition, GC genotyping did not significantly affect bioavailable 25(OH)D concentration. Therefore, if VDBP concentration is significantly altered, the measurement of bioavailable 25(OH)D concentration might facilitate the accurate determination of vitamin D status. However, GC genotyping might be unnecessary.

scholarly journals Amperometric Immunosensing Scaffolds for Rapid, Simple, Non-Invasive and Accurate Determination of Protein Biomarkers of Well-Accepted and Emerging Clinical Importance

Proceedings ◽  
2017 ◽  
Vol 1 (8) ◽  
pp. 727
Author(s):  
María Pedrero ◽  
Cristina Muñoz-San Martín ◽  
Rebeca M. Torrente-Rodríguez ◽  
Víctor Ruiz-Valdepeñas Montiel ◽  
Eva Vargas ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Clinical Importance ◽  
Protein Biomarkers ◽  
Non Invasive

scholarly journals III. Magnetic observations at Kerguelen

1878 ◽  
Vol 26 (179-184) ◽  
pp. 95-102
Keyword(s):  
Accurate Determination ◽  
Magnetic Survey ◽  
South Indian Ocean ◽  
Terrestrial Magnetism ◽  
Scientific Investigations ◽  
South Indian ◽  
Magnetic Elements ◽  
Complete Set ◽  
The Government

The Government expedition to Kerguelen Island for the observation of the Transit of Venus on December 8th, 1874, presented a very favour­able opportunity for the accurate determination of the magnetic elements of an important station in the South-Indian Ocean, and one which will at most be visited only at distant intervals for the purpose of scientific investigations. When, therefore, I heard of my appointment to that station, I at once brought the question of terrestrial magnetism under the notice of the Astronomer Royal, and he readily agreed to my pro­posal of taking a complete set of magnetic instruments to Kerguelen, and of making any observations that would not interfere with the main object of our expedition. Being in charge of the whole Kerguelen party of observers, I could not expect to be able to devote much time personally to the magnetic work; but the Rev. W. Sidgreaves, whom long experience, both at the Stony-hurst Observatory and during our magnetic survey of Prance in 1868 and 1869, had made perfectly conversant with all the details both of instruments and observations connected with terrestrial magnetism, had already been placed on the staff of astronomical observers for Kerguelen. The assistance of a very efficient observer being thus secured, the next step was to procure the necessary instruments. Fortunately I experi­enced no difficulty in this matter, as the authorities at Kew immediately placed at my disposal a Jones unifilar and a Barrow dip-circle. There was no question of the want of a good chronometer, as the astronomers were to be supplied with nine of these, besides the eight reserved exclu­sively for longitude connexions, which remained always undisturbed in their quiet berth on shipboard.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Fast calibration of CBED patterns for quantitative analysis

1993 ◽  
Vol 51 ◽  
pp. 674-675
Author(s):  
M.A. Gribelyuk ◽  
M. Rühle
Keyword(s):  
Reciprocal Lattice ◽  
Accurate Determination ◽  
Incident Beam ◽  
Crystal Thickness ◽  
Structure Model ◽  
Beam Direction ◽  
Transmitted Beam ◽  
Reciprocal Vector ◽  
On Line

A new method is suggested for the accurate determination of the incident beam direction K, crystal thickness t and the coordinates of the basic reciprocal lattice vectors V1 and V2 (Fig. 1) of the ZOLZ plans in pixels of the digitized 2-D CBED pattern. For a given structure model and some estimated values Vest and Kest of some point O in the CBED pattern a set of line scans AkBk is chosen so that all the scans are located within CBED disks.The points on line scans AkBk are conjugate to those on A0B0 since they are shifted by the reciprocal vector gk with respect to each other. As many conjugate scans are considered as CBED disks fall into the energy filtered region of the experimental pattern. Electron intensities of the transmitted beam I0 and diffracted beams Igk for all points on conjugate scans are found as a function of crystal thickness t on the basis of the full dynamical calculation.

Computer-Assisted High-Re Solution TEM

1990 ◽  
Vol 48 (1) ◽  
pp. 162-163
Author(s):  
F.A. Ponce ◽  
H. Hikashi
Keyword(s):  
Signal To Noise Ratio ◽  
Accurate Determination ◽  
Computer Software ◽  
Video Camera ◽  
Image Contrast ◽  
Objective Lens ◽  
Computer Assisted ◽  
Optical Parameters ◽  
Astigmatism Correction

The determination of the atomic positions from HRTEM micrographs is only possible if the optical parameters are known to a certain accuracy, and reliable through-focus series are available to match the experimental images with calculated images of possible atomic models. The main limitation in interpreting images at the atomic level is the knowledge of the optical parameters such as beam alignment, astigmatism correction and defocus value. Under ordinary conditions, the uncertainty in these values is sufficiently large to prevent the accurate determination of the atomic positions. Therefore, in order to achieve the resolution power of the microscope (under 0.2nm) it is necessary to take extraordinary measures. The use of on line computers has been proposed [e.g.: 2-5] and used with certain amount of success.We have built a system that can perform operations in the range of one frame stored and analyzed per second. A schematic diagram of the system is shown in figure 1. A JEOL 4000EX microscope equipped with an external computer interface is directly linked to a SUN-3 computer. All electrical parameters in the microscope can be changed via this interface by the use of a set of commands. The image is received from a video camera. A commercial image processor improves the signal-to-noise ratio by recursively averaging with a time constant, usually set at 0.25 sec. The computer software is based on a multi-window system and is entirely mouse-driven. All operations can be performed by clicking the mouse on the appropiate windows and buttons. This capability leads to extreme friendliness, ease of operation, and high operator speeds. Image analysis can be done in various ways. Here, we have measured the image contrast and used it to optimize certain parameters. The system is designed to have instant access to: (a) x- and y- alignment coils, (b) x- and y- astigmatism correction coils, and (c) objective lens current. The algorithm is shown in figure 2. Figure 3 shows an example taken from a thin CdTe crystal. The image contrast is displayed for changing objective lens current (defocus value). The display is calibrated in angstroms. Images are stored on the disk and are accessible by clicking the data points in the graph. Some of the frame-store images are displayed in Fig. 4.

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