An integrated investigation of oocyte developmental competence: expression of key genes in human cumulus cells, morphokinetics of early divisions, blastulation, and euploidy.

PURPOSE: To investigate the association of cumulus cell (CC)-related expression of a selected cluster of key genes (PTGS2, CAMK1D, HAS2, STC1, and EFNB2) with embryo development to blastocyst. METHODS: Exploratory study at a private clinic. Eighteen advanced maternal age patients were enrolled (37.3 ± 4.0 years). Seventy-five cumuli were collected, whose oocytes resulted in either developmental arrest (N = 33) or blastocyst formation (N = 42). The noninvasive CC gene expression was combined with time-lapse morphokinetic parameters and, for blastocysts, with qPCR-based aneuploidy testing on trophectoderm biopsies. RESULTS: The detection rate was 100% for all transcripts, but STC1 (96%) and CAMK1D (89%). Among amplified assays, CC mean expression levels of CAMK1D, PTGS2, and HAS2 were higher from oocytes that developed to blastocyst. No difference in CC key gene expression was reported between euploid (N = 21) and aneuploid (N = 21) blastocysts. Some timings of early embryo development were faster in embryos developing to blastocyst (time of pronuclei appearance and fading, division to two- and four-cells, first and second cell cycles). However, the generalized linear models outlined increasing CAMK1D expression levels as the strongest parameter associated with oocytes' developmental potential from both a general (AUC = 0.78 among amplified samples) and an intrapatient perspectives (AUC = 0.9 among patients obtaining ≥ 2 zygotes from the cohort with different developmental outcomes). CONCLUSIONS: CAMK1D level of expression in CCs associated with blastocyst development. If confirmed from larger studies in wider populations of patients, the investigation of CC key gene expression might suit IVF clinics not adopting blastocyst culture. Future investigations should clarify the role of CAMK1D in ovarian physiology and could provide novel insights on how oocytes gain competence during folliculogenesis.

No evidence of association between blastocyst aneuploidy and morphokinetic assessment in a selected population of poor-prognosis patients: a longitudinal cohort study.

Recent studies involving a limited number of patients have indicated a correlation between aneuploidy and various morphokinetic parameters during preimplantation development. The results among different groups, however, have been inconsistent in identifying the parameters that are able to predict chromosomal abnormalities. The aim of this study was to investigate whether aneuploidy of human blastocysts was detectable by specific morphokinetic parameters in patients at increased risk of aneuploidy because of advanced maternal age, history of unsuccessful IVF treatments, or both. A longitudinal cohort study was conducted using 455 blastocysts from 138 patients. Morphokinetic features of preimplantation development were detected in a timelapse incubator. Blastocysts were subjected to trophectodermal biopsy and comprehensive chromosomal screening. Analyses were conducted by means of logistic mixed-effects models, with a subject-specific intercept. No statistical correlation between 16 commonly detected morphokinetic characteristics of in-vitro embryo development and aneuploidy was found. Results suggest that morphokinetic characteristics cannot be used to select euploid blastocysts in poor-prognosis patients regarded as candidates for pre-implantation genetic screening.

Electrophysiological and morphological changes in rabbit retina after exposure to the light of the operating microscope.

Healthy adult rabbit eyes were exposed to up to 4 h of continuous illumination with moderate light intensity, as is produced by the lamp of an ophthalmic operating microscope. Electroretinograms were recorded before and after the long period of illumination. The depression of the waves in the electroretinograms observed just following light exposure recovered within 1 h to normal values. Electron microscopy of the retina revealed changes within the cells of the pigment epithelium. These results are discussed in view of their clinical implications in human patients.

Eye and head movements to visual and auditory targets.

Coordinated eye-head movements evoked by the presentation of visual, auditory and combined audio-visual targets were studied in 24 human subjects. At 60 deg located targets latencies of eye and head movements were shorter for auditory than for visual stimuli. Latencies were shorter for bisensory than for monosensory targets. The eye and head latencies were differently influenced by the modality of the stimulus when the eccentricity of the target was changed, but not by the variation of the stimulus duration. The different responses of the eye and the head depending on target modality and target eccentricity can be partially attributed to perceptual and central processing mechanisms, and are important to answer the question about the initial event in coordinated eye-head orientation.

A photosensitive method for measuring horizontal movements of the head to visual and auditory targets.

A simple photosensitive method to assess movements of the whole body or its parts was described. The method was applied to record head movements to target sources of visual and auditory stimuli.