P–518 Assessment of mitochondrial DNA viability ratio in day–4 biopsied embryos as an add-in to select euploid embryos for single embryo transfer

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A M Metwalley ◽  
A Hellani ◽  
S Esteves ◽  
A El-Damen ◽  
A Abde. Razik ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Embryo Transfer ◽  
Small Sample Size ◽  
Embryo Implantation ◽  
Critical Factor ◽  
Single Embryo Transfer ◽  
Small Sample ◽  
Embryo Viability ◽  
Prognostic Information ◽  
The Mean

Abstract Study question Is mitochondrial DNA viability ratio of day–4 biopsied embryos associated with embryo implantation potential? Summary answer The mitochondrial DNA viability ratio is significantly higher in embryos that implant. The score might help to select euploid embryos for single embryo transfer. What is known already Embryo euploidy is a critical factor for successful pregnancy outcomes. However, transfer of euploid embryos does not invariably result in implantation, thus indicating that other factors may play a role. Metabolic rates and adenosine triphosphate content vary significantly in oocytes and embryos and might affect embryo viability. Embryo function, indirectly measured by mitochondrial DNA viability ratio (mtV) has emerged as a potential quantitative biomarker for embryonic selection before the transfer, but clinical data remains limited. The purpose of this study is to characterize and compare mtV in euploidy day 4 embryos. Study design, size, duration Retrospective cohort study carried out between Jan. 2017 to Jan. 2020, involving 75 infertile couples undergoing IVF-ICSI with PGT-A and single embryo transfer (SET) of day 4 euploid embryos. Participants/materials, setting, methods We compared the mtV ratios of 34 non-pregnant patients with those of 41 patients who achieved clinical pregnancy after SET. The mtV ratio was obtained from a cohort of 75 euploidy embryos. The embryos were biopsied 80–85 hours post–ICSI and subjected to next-generation sequencing (NGS). The mtV was determined using Multiple of Mean (MoM) values, obtained by dividing the mtV ratio of individual embryos by the mean mtV value of all implanted embryos. Main results and the role of chance The mean mtV ratio (1.51; 95% confidence interval [CI] 1.25–1.77) of non-pregnant patients was significantly lower than those of pregnancy counterparts (2.5; 95% CI 1.82–2.68; p < 0.01). At a 0.5 MoM cutoff, the sensitivity and specificity of mtV ratio to discriminate between implanted embryos versus non-implanted embryos were 35.3% and 78.2%, respectively., with a positive predictive value (PPV) of 41.4%. Limitations, reasons for caution Our study is limited by the small sample size and lack of stratification by causes of female/male infertility. Endometrial receptivity issues, which could have contributed to implantation failure, was not evaluated. Wider implications of the findings: Assessment of mtV ratio could provide additional prognostic information for selecting euploid embryos for transfer in SET programs. Further research is warranted to establish the clinical utility of routine application of mtV evaluation in PGT programs. Trial registration number N/A

O-087 Embryos with higher mitochondrial DNA ratios show better clinical outcomes in single euploid embryo transfer

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
D Chen ◽  
C W Kao
Keyword(s):  
Mitochondrial Dna ◽  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Implantation Rate ◽  
Single Embryo Transfer ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Embryo Viability ◽  
Significant Difference ◽  
Euploid Embryo

Abstract Study question To assess whether there is a relationship between mitochondrial DNA content and implantation result. Summary answer The embryos with a higher mitochondrial DNA ratio increase pregnancy rate and implantation rate in single euploid embryo transfer. What is known already Mitochondria is an important organelle that generates energy during embryonic development. Recent literature points out that mitochondrial content and function may be related to implantation success and embryo viability. Some studies have linked increased ratios of mitochondrial DNA to aneuploidy, advanced maternal age, and euploid blastocyst with implantation failure, while others have failed to demonstrate similar findings. Study design, size, duration This study is a retrospective cohort study from 2016 to 2019, including 1465 single embryo transfer cycles. Participants/materials, setting, methods The involved embryos were biopsied on Day 5 or 6 and the mitochondrial DNA ratio of 1465 embryos was examined undergoing PGS/NGS. The mitochondrial DNA ratios were normalized for technical batch-to-batch variation. The mitochondrial DNA ratio between the implantation group and non-implantation group was statistically analyzed. Data were analyzed by the student’s t-test for continuous variables and Chi-square test for categorical variables. Main results and the role of chance The mitochondrial DNA ratio of embryos was no significant difference between different age spans ( p = 0.772) and ploidy (p = 0.224). D5 biopsied embryos, however, contained a significantly higher mitochondrial DNA ratio than D6 biopsied embryos (p < 0.0001). All of the single embryo transferred embryos were classified into two groups; implanted and non-implanted embryos. Results from 1465 transferred embryos show that the mitochondrial DNA ratio of implanted embryos was statistically significantly higher than non-implanted embryos (p = 0.0053). Besides, the cut-off values were established, dividing the transferred embryos into high and low mitochondrial DNA ratio groups. The pregnancy rate and implantation rate of the high mitochondrial DNA ratio group was higher than the low mitochondrial DNA ratio group: [Pregnancy rate] 74% vs. 63.5% (p = 0.0209); [Implantation rate] 57.3% vs. 50.8% (p = 0.1907). Limitations, reasons for caution The mitochondrial DNA ratios were analyzed by bioinformatics processing in Miseq reporter software (Illumina) files in the BAM and FASTQ format. Not sure if there is reproducibility in different sequencing platforms. Wider implications of the findings There still remains a lack of clarity regarding the relationship between mitochondrial function and transfer outcome. This retrospective study links an association between increased mtDNA content and increased implantation. Trial registration number not applicable

Stillbirth Rate and Weight at Birth of Quintuplets in Japan

1989 ◽  
Vol 38 (1-2) ◽  
pp. 65-69 ◽  
Author(s):  
Yoko Imaizumi
Keyword(s):  
Sample Size ◽  
Birth Order ◽  
Gestational Age ◽  
Size Effects ◽  
Maternal Age ◽  
Small Sample Size ◽  
Small Sample ◽  
Stillbirth Rate ◽  
The Mean

AbstractNation-wide data in Japan on births and prenatal deaths of 16 sets of quintuplets during 1974-1985 were analysed. Among the 16 sets, 3 sets were liveborn, 8 were stillborn, and 5 were mixed, with a stillbirth rate of 0.64 (51/80). Effects of sex, maternal age and birth order on the stillbirth rate were not considered because of the small sample size. Effects of gestational age and birthweight on stillbirth rate were also examined. The mean weight of the 40 quintuplet individuals was 1,048 g.

The use of frequency distributions in an attempt to detect host mortality induced by infections of diplostomatid metacercariae

Parasitology ◽  
1984 ◽  
Vol 89 (2) ◽  
pp. 209-220 ◽  
Author(s):  
C. R. Kennedy
Keyword(s):  
Small Sample Size ◽  
Parasite Burden ◽  
Fish Host ◽  
Small Sample ◽  
Host Age ◽  
Parasite Abundance ◽  
Frequency Distributions ◽  
Host Mortality ◽  
The Mean ◽  
Over Dispersion

SummaryFollowing recent suggestions that a peaked host age–parasite abundance curve, concomitant with a decline in the degree of dispersion of parasites in the older age classes of hosts, can provide evidence of parasite-induced host mortality, the changes in mean abundance and over-dispersion of metacercarial stages of Diplostomum spathaceum, D. gasterostei, Tylodelphys clavata and T. podicipina in relation to fish age were studied in a field locality. The mean parasite burden of D. spathaceum, D. gasterostei and T. clavata increased with host age and the maximum mean burden was found in the oldest hosts. The variance to mean ratio also increased in D. gasterostei, but decreased in the oldest hosts in D. spathaceum and T. clavata. It is concluded that this decrease could be due to parasite-induced host mortality but could equally be due to death of parasites within the host or to changes in infection rate or could be a reflection of the small sample size of the oldest fish. The mean burden of T. podicipina declined gradually with host age, but the variance to mean ratio remained constant and it is concluded that this could be explained by death of the parasites within the host. None of these data or data from other localities provided clear and unambiguous evidence of host mortality induced by heavy infections of any of the four species, although they are consistent with such mortality and do not refute such a possibility. It is concluded that it may be just as difficult to detect and unequivocally demonstrate parasite-induced host mortality in metacercarial digenean–fish host systems as in any other parasite–host systems.

scholarly journals Mitochondrial DNA Content Varies with Pathological Characteristics of Breast Cancer

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Ren-Kui Bai ◽  
Julia Chang ◽  
Kun-Tu Yeh ◽  
Mary Ann Lou ◽  
Jyh-Feng Lu ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Tumor Size ◽  
Small Sample Size ◽  
Small Sample ◽  
Coding Region ◽  
Normal Tissues ◽  
Pathological Characteristics ◽  
Loop Region ◽  
Tumor Tissues ◽  
Grade Ii

Changes in mitochondrial DNA (mtDNA) content in cancers have been reported with controversial results, probably due to small sample size and variable pathological conditions. In this study, mtDNA content in 302 breast tumor/surrounding normal tissue pairs were evaluated and correlated with the clinico-pathological characteristics of tumors. Overall, mtDNA content in tumor tissues is significantly lower than that in the surrounding normal tissues,P<0.00001. MtDNA content in tumor tissues decreased with increasing tumor size. However, when the tumor is very large (>50 cm3), mtDNA content started to increase. Similarly, mtDNA content decreased from grades 0 and I to grade II tumors, but increased from grade II to grade III tumors. Tumors with somatic mtDNA alterations in coding region have significantly higher mtDNA content than tumors without somatic mtDNA alterations (P<0.001). Tumors with somatic mtDNA alterations in the D-Loop region have significantly lower mtDNA content (P<0.001). Patients with both low and high mtDNA content in tumor tissue have significantly higher hazard of death than patients with median levels of mtDNA content. mtDNA content in tumor tissues change with tumor size, grade, and ER/PR status; significant deviation from the median level of mtDNA content is associated with poor survival.

scholarly journals The Impact of Improved Thermistor Calibration on the Expendable Bathythermograph Profile Data

2017 ◽  
Vol 34 (9) ◽  
pp. 1947-1961 ◽  
Author(s):  
Marlos Goes ◽  
Elizabeth Babcock ◽  
Francis Bringas ◽  
Peter Ortner ◽  
Gustavo Goni
Keyword(s):  
Small Sample Size ◽  
Heat Content ◽  
Small Sample ◽  
Profile Data ◽  
Expendable Bathythermograph ◽  
Different Types ◽  
Long Term Trends ◽  
The Mean ◽  
The Impact

AbstractExpendable bathythermograph (XBT) data provide one of the longest available records of upper-ocean temperature. However, temperature and depth biases in XBT data adversely affect estimates of long-term trends of ocean heat content and, to a lesser extent, estimates of volume and heat transport in the ocean. Several corrections have been proposed to overcome historical biases in XBT data, which rely on constantly monitoring these biases. This paper provides an analysis of data collected during three recent hydrographic cruises that utilized different types of probes, and examines methods to reduce temperature and depth biases by improving the thermistor calibration and reducing the mass variability of the XBT probes.The results obtained show that the use of individual thermistor calibration in XBT probes is the most effective calibration to decrease the thermal bias, improving the mean thermal bias to less than 0.02°C and its tolerance from 0.1° to 0.03°C. The temperature variance of probes with screened thermistors is significantly reduced by approximately 60% in comparison to standard probes. On the other hand, probes with a tighter weight tolerance did not show statistically significant reductions in the spread of depth biases, possibly because of the small sample size or the sensitivity of the depth accuracy to other causes affecting the analysis.

Swedish military officers through other nations’ eyes

2016 ◽  
Vol 24 (4) ◽  
pp. 615-633 ◽  
Author(s):  
Gerry Larsson ◽  
Carina Brandow ◽  
Maria Fors Brandebo ◽  
Alicia Ohlsson ◽  
Gunnar Åselius
Keyword(s):  
Negative Feedback ◽  
Small Sample Size ◽  
Comparative Method ◽  
Critical Factor ◽  
Work Force ◽  
Small Sample ◽  
Military Officers ◽  
Leadership Model ◽  
Content Type ◽  
Task Forces

Purpose Globalisation of working life means that many organisations are manned by people from different countries. A potentially critical factor is how members from various nations are looked upon by their partner countries. Such perception may be more or less accurate and affect organisational outcomes. The military is no exception as modern warfare is characterised by multinational composition of task forces. The aim of this paper was to gain a deeper understanding of how military officers from other nations perceive Swedish military officers and their leadership qualities in particular. Design/methodology/approach Interviews were conducted with 20 military officers representing ten nations. Interview questions were deduced from the Developmental leadership model. Responses were first coded inductively according to the constant comparative method. Generated categories were then deductively related to this leadership model. Findings The analysis resulted in positive and negative patterns. The positive picture included Swedish officers being perceived as calm, competent and generally good at exhibiting exemplary leadership behaviour, showing individualised consideration and creating an inspiring atmosphere. The negative side included opinions such as Swedish officers being too emotionally restrained, exhibiting poor self-confidence, discussing too much before making decisions and having difficulties giving negative feedback. The results are discussed in relation to the Developmental leadership model and the stereotype concept. Research limitations/implications Small sample size and a focus on military organisations imply a low degree of generalisability. Practical implications Three suggestions regarding Swedish officer education are presented: officer students should be given an increased awareness of how they are perceived by others, decision-making without group support and giving negative feedback in a constructive, straight forward, but still considerate way, should be practiced and more attention should be paid to emotion management. Originality/value The paper addresses an increasing tendency in work organisations – a multinational composition of the work force. The foundation of study in leadership theory and the stereotype concept is new.

scholarly journals Geographic Variation of the Curve-Billed Thrasher (Toxostoma Curvirostre) Complex

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 311-322
Author(s):  
Octavio R. Rojas-Soto
Keyword(s):  
Measurement Error ◽  
Small Sample Size ◽  
Morphological Characters ◽  
Color Pattern ◽  
Small Sample ◽  
Sierra Madre Occidental ◽  
Geographic Patterns ◽  
Western Group ◽  
Sierra Madre ◽  
The Mean

Abstract Geographic patterns of variation in morphological characters in the Curve-billed Thrasher (Toxostoma curvirostre) have been recognized by the description of seven subspecies. Twelve standard measurements, as well as three colorimetric characters and two color pattern characters, were analyzed to test whether subspecies limits predict patterns of variation. Measurement error was addressed by measuring each character three times and calculating the mean. A total of 821 male study skins were used, representing 29 locations. A variety of analysis revealed two major groups, an eastern and western group, divided by the Sierra Madre Occidental. Those two groups had previously been recognized as the curvirostre and palmeri groups, respectively. Those groups were also recovered by analysis of mtDNA. The two groups fulfill the requirements for species. The Tiburón Island (T. c. insularis) sample was distinct for several characters; however, small sample size precludes formal taxonomic recommendation. Within the two major groups, most characters showed incongruent clinal patterns of variation that did not match subspecies limits.

Evaluating Games in Classrooms

2013 ◽  
pp. 475-494 ◽  
Author(s):  
Günter Wallner ◽  
Simone Kriglstein ◽  
Johannes Biba
Keyword(s):  
Classroom Environment ◽  
Educational Games ◽  
Small Sample Size ◽  
Critical Factor ◽  
Black Box ◽  
Small Sample ◽  
Game Based Learning ◽  
Input And Output ◽  
Short Period ◽  
Controlled Environments

Educational games have gained wide acceptance over the years and have found their way into many classrooms. Numerous evaluations of such games have been published, but mostly evaluations were carried out in controlled environments, with a small sample size or over a short period of time. However, the particular context where playing takes place has been established as a critical factor for game-based learning. Moreover, educational games are often considered as black box, measuring only input and output variables but neglecting the intermediate process. Many researchers have therefore argued that evaluations of educational games have to go beyond testing the learning outcomes only and should also show how and why it works. In this chapter the authors describe the evaluation of the game DOGeometry, which was carried out in a classroom environment over a four month period. They report the development process, the design of the evaluation, results, challenges, and problems faced.

scholarly journals Implementation of a novel prehospital advance directive protocol in southeastern Ontario

CJEM ◽  
2007 ◽  
Vol 9 (04) ◽  
pp. 250-259 ◽  
Author(s):  
Rose P. Mengual ◽  
Michael J. Feldman ◽  
Gord R. Jones
Keyword(s):  
Prospective Observational Study ◽  
Small Sample Size ◽  
Small Sample ◽  
Decision Makers ◽  
Prehospital Setting ◽  
Do Not Resuscitate ◽  
Surrogate Decision Makers ◽  
The Mean ◽  
Surrogate Decision

ABSTRACTIntroduction:Do not resuscitate (DNR) orders are commonly accepted in most health care settings, but are less widely recognized in the prehospital setting. We describe the implementation of and satisfaction with a prehospital DNR protocol that allows paramedics to honour verbal and non-standard written DNR requests.Methods:This prospective observational study reviewed all cardiac arrests in southeastern Ontario between March 1, 2003 and September 31, 2005. Following a verbal or non-standard written DNR request, paramedics completed a questionnaire and a follow-up structured telephone interview was conducted with surrogate decision makers (SDMs).Results:There were 1890 cardiac arrests during the study period, of which 86 met our inclusion criteria. Paramedic surveys were available for 82 cases (95%), and surrogate decision makers (SDMs) were successfully contacted in 50 (58%) of them. Two SDMs declined to be interviewed. The mean patient age was 72.7 (standard deviation 13.8) years and 65% were male. Sixty-three (73%) of DNR requests were verbal, and 23 (27%) were written. The mean paramedic comfort was rated 4.9 on a 5-point Likert scale (with 5 being “very comfortable” ) (95% confidence interval [CI] 4.9–5.0). The mean SDM comfort was rated by paramedics as 4.9 (95% CI 4.8 –4.9). SDMs reported comfort in withholding CPR in 47 of 48 cases (98%), and with paramedic care in all cases. One SDM stated that although it was consistent with the patient's wishes, she was uncomfortable having to make the DNR request.Conclusions:Satisfaction with this novel prehospital DNR protocol was uniformly high among paramedic and SDM respondents. It appears that such a protocol is feasible and acceptable for the prehospital setting. Our conclusions are limited by a small sample size, the lack of a comparison group, and limited follow-up.

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