ABSTRACT
Meiotic rapid prophase chromosome movements (RPMs) require connections between the chromosomes and the cytoskeleton, involving SUN (Sad1/UNC-84)-domain-containing proteins at the inner nuclear envelope (NE). RPMs remain significantly understudied in plants, with respect to their importance in the regulation of meiosis. Here, we demonstrate that Arabidopsis thaliana meiotic centromeres undergo rapid (up to 500 nm/s) and uncoordinated movements during the zygotene and pachytene stages. These centromere movements are not affected by altered chromosome organization and recombination but are abolished in the double mutant sun1 sun2. We also document the changes in chromosome dynamics and nucleus organization during the transition from leptotene to zygotene, including telomere attachment to SUN-enriched NE domains, bouquet formation, and nucleolus displacement, all of which were defective in sun1 sun2. These results establish A. thaliana as a model species for studying the functional implications of meiotic RPMs and demonstrate the mechanistic conservation of telomere-led RPMs in plants.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Chromosomes, Plant , Meiosis , Nuclear Envelope , Telomere , Arabidopsis/genetics , Arabidopsis/metabolism , Nuclear Envelope/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Chromosomes, Plant/genetics , Telomere/metabolism , Centromere/metabolism , Prophase , Meiotic Prophase I , Nuclear Proteins/metabolism , Nuclear Proteins/geneticsABSTRACT
PURPOSE: To document the association of CAD-related disorder (EIEE-50) with cortical visual impairment. OBSERVATIONS: An 8-month-old Caucasian boy with whole genome sequencing confirming 2 variants in the gene CAD, who presented with severe seizures, microcephaly, hyperreflexia, hypotonia, anemia, and severe cortical visual impairment. Magnetic resonance imaging (MRI) of the brain noted thickened cortical gray matter along the right calcarine fissure as well as changes suggesting malformation of cortical development. Empiric uridine monophosphate supplementation has significantly improved seizure activity, hypotonia, and development and has led to resolution of anemia. CONCLUSIONS AND IMPORTANCE: CAD-related disorder is treatable and may affect visual cortical development causing severe secondary cortical visual impairment, a newly described clinical manifestation.
Subject(s)
Magnetic Resonance Imaging , Humans , Male , Infant , Vision Disorders/etiologyABSTRACT
A high prevalence of mpox in men who have sex with men and in people with HIV, plus visually striking and contagious lesions, have raised concerns for mpox stigma. 24 PCR-confirmed mpox patients were surveyed over the course of three months, utilizing an mpox stigma scale adapted from the HIV Stigma Scale plus assessment of pain, analgesic efficacy, and healthcare experiences. Participants were cis-male (100%), with male sexual partners (96%), mostly African-American (88%), and living with HIV (79%). Patients answered 4-16 of 24 (mean 10) stigma questions affirmatively, particularly related to negative effects of mpox on the LGBTQ community. 79% reported pain, most commonly of limbs and perianal area, with perianal pain being rated most severe. The most effective pain relief occurred with opioids (100% major relief, n = 2) and tecovirimat (63% major relief, 25% moderate, n = 16). Patients were satisfied with care provided at the studied clinics, but had negative experiences at all other mentioned sites.
Subject(s)
Pain , Social Stigma , Humans , Male , Adult , Middle Aged , Pain/psychology , Baltimore/epidemiology , Surveys and Questionnaires , Disease Outbreaks , Homosexuality, Male/psychology , HIV Infections/psychology , HIV Infections/epidemiology , HIV Infections/drug therapy , Female , Sexual and Gender Minorities/psychology , Young AdultABSTRACT
Meiosis is a specialized eukaryotic division that produces genetically diverse gametes for sexual reproduction. During meiosis, homologous chromosomes pair and undergo reciprocal exchanges, called crossovers, which recombine genetic variation. Meiotic crossovers are stringently controlled with at least one obligate exchange forming per chromosome pair, while closely spaced crossovers are inhibited by interference. In Arabidopsis, crossover positions can be explained by a diffusion-mediated coarsening model, in which large, approximately evenly spaced foci of the pro-crossover E3 ligase HEI10 grow at the expense of smaller, closely spaced clusters. However, the mechanisms that control HEI10 dynamics during meiosis remain unclear. Here, through a forward genetic screen in Arabidopsis, we identified high crossover rate3 (hcr3), a dominant-negative mutant that reduces crossover interference and increases crossovers genome-wide. HCR3 encodes J3, a co-chaperone related to HSP40, which acts to target protein aggregates and biomolecular condensates to the disassembly chaperone HSP70, thereby promoting proteasomal degradation. Consistently, we show that a network of HCR3 and HSP70 chaperones facilitates proteolysis of HEI10, thereby regulating interference and the recombination landscape. These results reveal a new role for the HSP40/J3-HSP70 chaperones in regulating chromosome-wide dynamics of recombination via control of HEI10 proteolysis.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/genetics , Arabidopsis/metabolism , Crossing Over, Genetic , Proteolysis , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , MeiosisABSTRACT
AIMS: Patients with heart failure (HF) experience various signs and symptoms and have difficulties in perceiving them. Integrating insights from patients who have engaged in the process of symptom perception is crucial for enhancing our understanding of the theoretical concept of symptom perception. This study aimed to describe how patients with HF perceive symptoms through the processes of monitoring, awareness, and evaluation and what influences the process. METHODS AND RESULTS: Using a qualitative descriptive design, we conducted in-person semi-structured interviews with a purposeful sample of 40 adults experiencing an unplanned hospitalization for a HF symptom exacerbation. We elicited how patients monitor, become aware of, and evaluate symptoms prior to hospitalization. Data were analysed using directed qualitative content analysis. One overarching theme and three major themes emerged. Patients demonstrated Body listening, which involved active and individualized symptom monitoring tactics to observe bodily changes outside one's usual range. Trajectory of bodily change involved the patterns or characteristics of bodily changes that became apparent to patients. Three subthemes-sudden and alarming change, gradual change, and fluctuating change emerged. Patients evaluated symptoms through an Exclusionary process, sequentially attributing symptoms to a cause through a cognitive process of excluding possible causes until the most plausible cause remained. Facilitators and barriers to symptom monitoring, awareness, and evaluation were identified. CONCLUSION: This study elaborates the comprehensive symptom perception process used by adults with HF. Tailored nursing interventions should be developed based on the factors identified in each phase of the process to improve symptom perception in HF.
Subject(s)
Heart Failure , Qualitative Research , Humans , Heart Failure/psychology , Female , Male , Aged , Middle Aged , Adult , Awareness , Aged, 80 and over , Symptom Assessment/methods , Monitoring, Physiologic/methodsABSTRACT
PURPOSE: Utilization of navigation improves pedicle screw accuracy in adolescent idiopathic scoliosis (AIS). Our center switched from intraoperative CT (ICT) to an optical navigation system that utilizes pre-operative CT (PCT). We aim to evaluate the radiation dose and operative time for low-dose ICT compared to standard and low-dose PCT used for optical navigation in AIS patients undergoing posterior spinal fusion. METHODS: A single-center matched-control cohort study of 38 patients was conducted. Nineteen patients underwent ICT navigation (O-arm) and were matched by sex, age, and weight to 19 patients who underwent PCT for use with an optical-guided navigation (7D, Seaspine). A total of 418 levels were instrumented and reviewed. PCT was either a standard dose (N = 7) or a low dose (N = 12). The mean volume CT dose index, dose-length product, overall effective dose (ED), ED per level instrumented, and operative time per level were compared. RESULTS: ED per level instrumented was 0.061 ± 0.029 mSv in low-dose PCT and 0.14 ± 0.05 mSv in low-dose ICT (p < 0.0001). ED per level instrumented was significantly higher in standard PCT (1.46 ± 0.39 vs. 0.14 ± 0.03 mSv; p < 0.0001). Mean operative time per level was 31 ± 7 min for ICT and 33 ± 3 min for PCT (p = 0.628). CONCLUSION: Low-dose PCT resulted in 0.70 mSv exposure per case and 31 min per level, standard-dose was 16.95 mSv, while ICT resulted in 1.34-1.62 mSv and a similar operative time. Use of a standard-dose PCT involves radiation exposure about 9 times higher than ICT and 23 times higher than low-dose PCT per level instrumented. LEVEL OF EVIDENCE: Level III.
Subject(s)
Kyphosis , Radiation Exposure , Scoliosis , Surgery, Computer-Assisted , Adolescent , Humans , Scoliosis/diagnostic imaging , Scoliosis/surgery , Scoliosis/etiology , Cohort Studies , Imaging, Three-Dimensional , Tomography, X-Ray Computed/methods , Surgery, Computer-Assisted/methods , Kyphosis/etiologyABSTRACT
PURPOSE: Imaging changes in the pituitary volume during pregnancy remains scantly researched. This study set out to assess the differences in total, anterior, and posterior pituitary volume in pregnant women compared to nulliparous and post-partum women. MATERIALS AND METHODS: A retrospective review was completed of women that had undergone MRI imaging of the brain. Patients were divided into three cohorts: pregnant, nulliparous, and post-partum (defined as being within 12 months of delivery). Anterior and posterior pituitary volumes were manually measured. RESULTS: 171 patients were included, of which 68 were pregnant, 52 were post-partum, and 51 were nulliparous. The average anterior (621.0 ± 171.6 mm3) and total (705.4 ± 172.2 mm3) pituitary volumes were significantly larger in pregnant patients than nulliparous women (522.6 ± 159.8 mm3 and 624.5 ± 163.7 mm3, respectively) (p = .002 and p = .01, respectively). The posterior pituitary volume was significantly smaller in pregnant women (84.4 ± 32.9 mm3) compared to both post-partum (101.2 ± 42.0 mm3) and nulliparous (102.0 ± 46.1 mm3) women (p = .02 for both). CONCLUSIONS: The anterior and total pituitary volumes are significantly larger during pregnancy persisting into the post-partum period. The posterior pituitary volume, conversely, decreases during pregnancy, and returns to its normal size in the post-partum period.
Subject(s)
Pituitary Diseases , Postpartum Period , Pregnancy , Female , Humans , Pituitary Gland/diagnostic imaging , Retrospective Studies , Magnetic Resonance ImagingABSTRACT
The synaptonemal complex (SC) is a proteinaceous structure that forms between homologous chromosomes during meiosis prophase. The SC is widely conserved across species, but its structure and roles during meiotic recombination are still debated. While the SC central region is made up of transverse filaments and central element proteins in mammals and fungi, few central element proteins have been identified in other species. Here we report the identification of two coiled-coil proteins, SCEP1 and SCEP2, that form a complex and localize at the centre of the Arabidopsis thaliana SC. In scep1 and scep2 mutants, chromosomes are aligned but not synapsed (the ZYP1 transverse filament protein is not loaded), crossovers are increased compared with the wild type, interference is lost and heterochiasmy is strongly reduced. We thus report the identification of two plant SC central elements, and homologues of these are found in all major angiosperm clades.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Animals , Synaptonemal Complex/genetics , Synaptonemal Complex/metabolism , Prophase , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Meiosis , Mammals/geneticsABSTRACT
Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.
Subject(s)
Photons , Tomography, X-Ray Computed , Humans , Child , Tomography, X-Ray Computed/methods , X-Rays , Phantoms, ImagingABSTRACT
Most primary orbital pathology in children is due to bacterial infection. Radiologists typically encounter these cases to evaluate for clinically suspected postseptal orbital involvement. Contrast-enhanced cross-sectional imaging is important for the detection and early management of orbital infection and associated subperiosteal/orbital abscess, venous thrombosis, and intracranial spread of infection. Benign mass-like inflammatory processes involving the pediatric orbit are rare, have overlapping imaging features, and must be distinguished from orbital malignancies.
Subject(s)
Orbital Cellulitis , Orbital Diseases , Sinusitis , Child , Humans , Orbit , Sinusitis/complications , Tomography, X-Ray Computed , Orbital Cellulitis/complications , Orbital Cellulitis/microbiology , Radiologists , Orbital Diseases/diagnostic imaging , Orbital Diseases/complicationsABSTRACT
Pituitary development arises from ectodermal tissue creating Rathke's pouch and ultimately the adenohypophysis anteriorly whereas neuroectodermal tissue arising from the diencephalon creates the neurohypophysis posteriorly. Alterations in pituitary development can lead to hormonal dysregulation and dysfunction. Following clinical suspicion of pituitary endocrinopathy, MRI plays a vital role in identifying and characterizing underlying structural abnormalities of the pituitary gland, as well as any associated extrapituitary findings. Here we report a case of an 18-month-old female presenting with short stature and growth hormone deficiency. MRI was notable for a shallow sella turcica, a hypoplastic adenohypophysis, thin pituitary stalk, and ectopic neurohypophysis. Interestingly, the pituitary stalk was noted to split dorsoventrally with a split pituitary bright spot and T1 hypointense lobe hypothesized to represent separation of the posterior pituitary lobes.
ABSTRACT
The fifth edition of the World Health Organization classification of tumors of the central nervous system (CNS), published in 2021, introduces major shifts in the classification of brain and spine tumors. These changes were necessitated by rapidly increasing knowledge of CNS tumor biology and therapies, much of which is based on molecular methods in tumor diagnosis. The growing complexity of CNS tumor genetics has required reorganization of tumor groups and acknowledgment of new tumor entities. For radiologists interpreting neuroimaging studies, proficiency with these updates is critical in providing excellent patient care. This review will focus on new or revised CNS tumor types and subtypes, beyond infiltrating glioma (described in part 1 of this series), with an emphasis on imaging features.
Subject(s)
Brain Neoplasms , Central Nervous System Neoplasms , Glioma , Humans , Central Nervous System Neoplasms/diagnostic imaging , Glioma/diagnostic imaging , Brain/pathology , World Health Organization , RadiologistsABSTRACT
BACKGROUND: Temporal lobe encephaloceles (TEs) are a rare cause of drug-resistant temporal lobe epilepsy (DR-TLE), with head trauma and obesity identified as risk factors in adults. This study evaluated the clinical characteristics of childhood-onset DR-TLE due to TE. METHODS: This is a single-institution retrospective review of childhood-onset DR-TLE with radiographic TE identified between 2008 and 2020. The epilepsy history, brain imaging features, and surgical outcomes were collected. RESULTS: Eleven children with DR-TLE due to TE were included (median age at epilepsy onset was 11 years, interquartile range 8.5 to 13.5 years). Median latency between epilepsy diagnosis and TE detection was 3 years (range of 0 to 13 years). None had history of head trauma. Body mass index greater than 85 percentile for age and sex was seen in 36% of the children. No patient had bilateral TE identified. TEs were diagnosed based on epilepsy surgery conference re-review of imaging in 36% of cases. All herniations were contained defects without osseous dehiscence. Regional fluorodeoxyglucose (FDG) hypometabolism ipsilateral to the encephalocele was seen in all children who had FDG-positron emission tomography (PET) of the brain. Of the children who had surgery, 70% were seizure free or had nondisabling seizures at last follow-up (mean follow-up 52 months). CONCLUSIONS: TE is a surgically remediable etiology of DR-TLE in childhood. TEs are often overlooked at pediatric epilepsy diagnosis, calling for the need to increase awareness of this entity. FDG-PET temporal hypometabolism in children with presumed nonlesional DR-TLE should be carefully examined for occult TEs.
Subject(s)
Drug Resistant Epilepsy , Epilepsy, Temporal Lobe , Epilepsy , Adult , Humans , Child , Adolescent , Epilepsy, Temporal Lobe/diagnostic imaging , Epilepsy, Temporal Lobe/etiology , Epilepsy, Temporal Lobe/surgery , Encephalocele/etiology , Encephalocele/complications , Fluorodeoxyglucose F18 , Temporal Lobe/surgery , Drug Resistant Epilepsy/diagnostic imaging , Drug Resistant Epilepsy/etiology , Drug Resistant Epilepsy/surgery , Epilepsy/complications , Magnetic Resonance Imaging/methods , Treatment OutcomeABSTRACT
Childhood spinal tumors are rare. Tumors can involve the spinal cord, the meninges, bony spine, and the paraspinal tissue. Optimized imaging should be utilized to evaluate tumors arising from specific spinal compartments. This paper provides consensus-based recommendations for optimized imaging of tumors arising from specific spinal compartments at diagnosis, follow-up during and after therapy, and response assessment.
Subject(s)
Spinal Cord Neoplasms , Surface Plasmon Resonance , Child , Humans , Spine , Spinal Cord Neoplasms/diagnostic imaging , Spinal Cord , Magnetic Resonance ImagingABSTRACT
The fifth edition of the World Health Organization (WHO) classification of tumors of the central nervous system, published in 2021, contains substantial updates in the classification of tumor types. Many of these changes are relevant to radiologists, including "big picture" changes to tumor diagnosis methods, nomenclature, and grading, which apply broadly to many or all central nervous system tumor types, as well as the addition, elimination, and renaming of multiple specific tumor types. Radiologists are integral in interpreting brain tumor imaging studies and have a considerable impact on patient care. Thus, radiologists must be aware of pertinent changes in the field. Staying updated with the most current guidelines allows radiologists to be informed and effective at multidisciplinary tumor boards and in interactions with colleagues in neuro-oncology, neurosurgery, radiation oncology, and neuropathology. This review represents the first of a two-installment review series on the most recent changes to the WHO brain tumor classification system. This first installment focuses on the changes to the classification of adult and pediatric gliomas of greatest relevance for radiologists.
Subject(s)
Brain Neoplasms , Central Nervous System Neoplasms , Glioma , Adult , Brain Neoplasms/pathology , Central Nervous System Neoplasms/diagnostic imaging , Child , Glioma/diagnostic imaging , Glioma/pathology , Humans , Radiologists , World Health OrganizationABSTRACT
Pediatric orbital masses are not common but encompass a wide spectrum of benign and malignant entities that range from developmental anomalies to primary and secondary orbital malignancies and metastatic disease. Certain orbital tumors are unique to pediatric patients, such as retinoblastoma and neuroblastoma. Clinical symptoms and signs are often insufficient to differentiate between orbital lesions, and imaging is essential for narrowing the diagnostic considerations and determining the most appropriate management strategy. MRI is the primary imaging modality for evaluating orbital masses in children, with US and CT playing complementary roles. The authors review a spectrum of masses and tumor mimics that affect the pediatric globe and orbit. The shared and differentiating characteristics of pediatric orbital lesions are reviewed. Emphasis is placed on utilizing an orbital compartment-based approach to narrow the differential diagnosis. By using this organizational scheme, the authors describe intraocular processes (retinoblastoma, persistent fetal vasculature, and Coats disease), intraconal lesions (lymphatic malformation, schwannoma, optic nerve sheath meningioma, and optic pathway glioma), extraconal lesions (infantile hemangioma, rhabdomyosarcoma, idiopathic orbital inflammation, lymphoma, venous varix, plexiform neurofibroma, and pleomorphic adenoma of the lacrimal gland), and lesions involving the bony orbit (dermoid cyst, metastatic neuroblastoma, and Langerhans cell histiocytosis). The authors describe the basic management of each entity. Orbital infections and traumatic lesions are beyond the scope of this article. ©RSNA, 2022.
Subject(s)
Meningeal Neoplasms , Neoplasms, Second Primary , Neuroblastoma , Orbital Neoplasms , Retinal Neoplasms , Retinoblastoma , Child , Humans , Magnetic Resonance Imaging/methods , Neuroblastoma/diagnostic imaging , Orbital Neoplasms/diagnostic imaging , Orbital Neoplasms/pathologyABSTRACT
Hormonal contraceptives have been used in perimenopausal women to manage a variety of symptoms and prevent unintended pregnancy. However, it is unclear what contraceptive regimen is best for these women. To evaluate hormonal contraceptive methods in women experiencing perimenopause using two prespecified outcomes: perimenopausal symptom management and long-term effects. A literature search of PubMed and EMBASE databases was performed (January 1990 to October 2021) using search terms "perimenopause" and "contraception." Relevant full-text articles in English were included. Fifteen clinical articles were reviewed: Fourteen were internationally based, and one study was conducted in the United States. Nine articles evaluated symptom resolution, and six of these nine reported statistically significant changes in favor of treating perimenopausal women with hormonal contraceptives compared with no treatment. Seven studies evaluated long-term outcomes including bone loss and metabolic parameters, and six of these seven showed statistically significant improvements with hormonal contraceptives. Based on limited data and a lack of comparative studies, the use of a levonorgestrel intrauterine device with supplemental low-dose menopausal estrogen has positive results for the management of disruptive perimenopausal symptoms and long-term outcomes. Hormonal contraception in perimenopausal women improves symptom management and long-term outcomes if patients do not have contraindications. When selecting a contraceptive for women in perimenopause, clinicians and pharmacists need to address specific patient risk factors, symptom profiles, long-term risks and benefits, and patient preferences.
Subject(s)
Contraceptive Agents , Perimenopause , Contraception/methods , Female , Humans , Menopause , Pregnancy , Risk FactorsABSTRACT
The cerebrofacial metameric syndromes are a group of congenital syndromes that result in vascular malformations throughout specific anatomical distributions of the brain, cranium and face. Multiple reports of patients with high-flow or low-flow vascular malformations following a metameric distribution have supported this idea. There has been much advancement in understanding of segmental organization and cell migration since the concept of metameric vascular syndromes was first proposed. We aim to give an updated review of these embryological considerations and then propose a more detailed classification system for these syndromes, predominately incorporating the contribution of neural crest cells and somitomeres to the pharyngeal arches.
Subject(s)
Head , Vascular Malformations , Brain , Humans , Neural Crest , SyndromeABSTRACT
Cervicofacial vascular anomalies can result in morbidity, pain, and cosmetic concerns in affected individuals. Each anomaly has its own unique natural history, treatment, and associations with underlying genetic syndromes. For optimal patient care, it is important for the neuroradiologist to accurately recognize and characterize these entities to ensure appropriate treatment and management. In this review, we discuss the general characteristics, classifications, and imaging features associated with the most common vascular anomalies such as hemangiomas, arteriovenous malformations and fistulas, capillary malformations, venous malformations, and lymphatic malformations in the context of associated syndromes. Additionally, we discuss novel imaging techniques that aid in identifying these vascular anomalies.