China
Africa
Explore chapters and articles related to this topic
Lung and Tracheo-Bronchial Tumours - main types.
Published in Fred W Wright, Radiology of the Chest and Related Conditions, 2022
Heitzman et al. (1982) used the term 'corona radiata', as they have seen it with some benign fibrotic conditions. Nordenstrom (1987) also noted its occurrence with some benign tumours and granulomas.
Fertilization and normal embryonic and early fetal development
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Asim Kurjak, Ritsuko K. Pooh, Aida Salihagic-Kadic, Iva Lausin, Lara Spalldi-Barisic
Already few minutes after the ovulation, oocyte is located in the ampullar part of the fallopian tube. It is surrounded by the zona pellucida. On the surface of the zona pellucida, there are few rows of the granulosa cells that make corona radiata. At the periphery of the corona radiata are left cells of cumulus oophorus. Often, these three units are called oocyte–corona–cumulus complex. Capability for the fertilization is limited: oocyte can be fertilized only 6 to 12 hours after the ovulation. Sperms are capable for fertilization 48 to 72 hours, until they are movable. Fertilization occurs in the ampullar part of the fallopian tube. The process of fertilization begins with conditioning of the spermatozoon in the male and female reproductive tracts. Thereafter, fertilization involves not only the egg itself but also the various investments that surround the egg at the time it is released from the ovary follicle. Fertilization, therefore, is not an event; it is a complex biochemical process requiring a minimum of 24 hours to complete syngamy (formation of a diploid set of chromosomes). During that process, there is no commingling of maternal and paternal chromosomes within a single nuclear membrane (pre-zygote); after this process, the paternal chromosome material is commingled (zygote). The most important activity of this new cell is the recognition of the new genome that presents the principal information center for the development of the human being and for all its further activities.
In Vitro Fertilization and Embryo Transfer
Published in Asim Kurjak, Ultrasound and Infertility, 2020
Between 100,000 and 500,000 motile spermatosoids are added to every mature oocyte. Out of those 500,000 spermatozoa, 500 to 1000 manage to stick to the zone pellucida of the oocyte. Although in natural circumstances such a high number of spermatozoa never get into contact with a single oocyte, up to now statistics show that no significant difference between the number of triploidias resulting from in vitro program (4%) and ones spotted in early abortions following natural reproduction could be spotted (8%). To ensure fertilization, the oocyte is kept in insemination medium for not less than 16 to 18 h. Now the microscopic examination in normally fertilized ova should show male and female nuclei and two polar bodies. Sometimes, however, corona radiata cells obstruct a clear view on fertilization and, to get a view of the oocyte, cytoplasm should be removed.
Altered white matter diffusivity and subtle motor function in a pilot cohort of adolescents with sports-related concussion
Published in Brain Injury, 2022
Jewel E. Crasta, Robert N. Tucker, Joshua Robinson, Hsuan Wei Chen, Deana Crocetti, Stacy J. Suskauer
Few studies have examined the association between DTI metrics and motor measures in children with brain injury. In children with mild to moderate brain injury assessed 6-months post-injury, lower FA of the corpus callosum was associated with slower motor speed (60). In children with varying degrees of severity of brain injury in the chronic stage of recovery (> 6 months post-injury), reduced FA of the corticospinal tract as compared to controls was associated with balance and motor coordination deficits (61,62). The superior corona radiata which includes the corticospinal tract has an important role in motor function (33). These results show that DTI metrics can link the microstructure of motor-associated white matter pathways to subtle motor function in adolescents with acute SRC. However, further research is required to identify if injury to specific white matter pathways and regions is responsible for motor deficits observed in SRC. Given the minimal studies examining brain–behavior relations with sensitive assessments in adolescents with SRC, the present study findings may be of particular importance in identifying promising measures that should be further explored in larger studies.
Longitudinal Changes in the Sensorimotor Pathways of Very Preterm Infants During the First Year of Life With and Without Intervention: A Pilot Study
Published in Developmental Neurorehabilitation, 2021
Sonia Khurana, Megan E Evans, Claire E Kelly, Deanne K Thompson, Jennifer C. Burnsed, Amy D. Harper, Karen D. Hendricks-Muñoz, Mary S Shall, Richard D Stevenson, Ketaki Inamdar, Gregory Vorona, Stacey C Dusing
DTI metrics (FA and MD) and volume were calculated for five white matter regions of interest (ROIs): i) corticospinal tract (CST), ii) posterior limb of internal capsule (PLIC), iii) corona radiata (CR), iv) cerebral peduncles (CP), and v) cerebellar peduncles (CBP). In case of cerebellar peduncle we averaged superior, middle, and inferior cerebellar peduncle together to obtain one single value each for FA and MD. However, volume was derived by adding the values of all three regions together into one. The CST was chosen to be the primary region of interest based on its importance in the output of voluntary movement, as well as the extensive literature on CST dysfunction in preterm infants.25 Likewise, the PLIC is commonly used to predict the development of cerebral palsy based on the amount of myelination.26 Lastly, the corona radiata, cerebral peduncles, and cerebellar peduncles (superior, middle, and inferior) were included based on their role in motor learning and motor processing.27,28
Varicella-zoster virus causing a ring-like cerebral lesion in AIDS
Published in Baylor University Medical Center Proceedings, 2020
Jennifer Nielsen Fan, Robyn R. Fader, MaryAnn P. Tran, Christie Ann Shen
MRI of the brain showed a ring-enhancing lesion in the region of the left corona radiata measuring 1.0 × 0.8 × 0.7 cm (Figure 1). HIV screening and a confirmatory test returned positive for HIV-1 antibodies. The patient’s clinical status began to improve on acyclovir, and by hospital day 3 he was oriented to person, place, and time. When more alert, the patient reported being screened for HIV many years ago but not recently. Cerebrospinal fluid Gram stain and culture returned negative, and cerebrospinal fluid cell count with differential showed a white blood cell count of 24 × 109/L, a lymphocytic predominance of 96%, high protein of 140 g/dL, and low glucose of 35 mg/dL. A meningitis/encephalitis panel was positive for varicella-zoster virus. His CD4 count was 211 (9%), and Toxoplasma IgG and IgM antibodies returned negative. Other workup performed on the cerebrospinal fluid was negative, including tests for Bartonella, Cryptococcus, coccidioidomycosis, blastomycosis, histoplasmosis, tuberculosis, acid-fast bacilli, syphilis, Epstein-Barr virus, arbovirus, and BK and JC virus. A brain biopsy ruled out primary central nervous system lymphoma but showed perivascular lymphocytosis consistent with a vasculitis of infectious etiology. He was discharged to a rehabilitation facility after 4 weeks of inpatient care and has been improving with antiretroviral therapy.