Anatomical variations of the frontal sinus: A computed tomography-based study.

Background: The pneumatization of the frontal sinus is variable between individuals, including monozygotic twins. The volumetric anatomic variants of the frontal sinus are classified into aplasia, hypoplasia, medium-sized, and hyperplasia. We aimed to study the frontal sinus morphology in Omani patients using computed tomography (CT) evaluations. Methods: Retrospectively, 1220 frontal sinus CT scans from 610 patients investigated at Sultan Qaboos University Hospital, Oman, from January 2019 to December 2020 were reviewed. The frontal sinus morphology was classified according to the classification proposed by Guerram et al. The Chi-square test was used to determine the influence of sex. Results: With regard to the unilateral occurrence, the most prevalent frontal sinus category observed was medium-sized (13.3%), followed by hyperplasia (7.9%), hypoplasia (5.4%), and aplasia (2%) categories. Similarly, in bilateral occurrence, the most common frontal sinus category observed was medium-sized (53%), followed by hyperplasia (13.1%), hypoplasia (3.4%) and aplasia (2%) categories. Right and left frontal sinus aplasia were observed in 2.1% and 1.8% of cases, respectively. In terms of sex influence, the left unilateral ( p<0.01) and the bilateral hypoplasia ( p<0.05) were significantly higher in females. On the other hand, the left unilateral ( p<0.01) and the bilateral hyperplasia ( p<0.05) were higher in males. Conclusions: The baseline data of frontal sinus category frequencies reported in the present study is helpful in the diagnostic evaluation of sinusitis in the clinical setting. The preoperative recognition of frontal sinus types, particularly frontal sinus aplasia in multiplanar CT scans, is crucial to avoid unexpected complications while performing endoscopic sinus surgery.

Prevalence of Congenital Uterine Anomalies and Tubal Blockage in Infertile Omani Women: A Retrospective Study.

Objectives: Congenital uterine anomalies (CUAs) occur because of malformation of the female genital tract at any stage of the Müllerian duct development process. This retrospective study investigated the prevalence of CUAs and tubal blockage in infertile Omani women who underwent a hysterosalpingogram procedure as part of the evaluation of infertility. Methods: The radiographic reports of patients aged 19-48 years who underwent hysterosalpingogram as part of infertility evaluation during the 2013-2018 period, were collected and analyzed for the presence and the type of CUAs. Results: The records of N = 912 patients were evaluated, 44.3% of whom had been investigated for primary infertility and 55.7% for secondary infertility. Patients with primary infertility were significantly younger than those with secondary infertility. Of the 27 (3.0%) patients who were found to have CUAs, 19 had arcuate uterus. No correlation was found between the type of infertility and the CUAs. Conclusions: CUAs were prevalent in 3.0% of the cohort, most of whom were diagnosed with arcuate uterus.

Oncologists' Knowledge, Practice and Attitude toward Fertility Preservation: A National Survey.

BACKGROUND: Improved chemotherapy and radiotherapy treatment protocols, fortunately, increased the rates of cancer survivors over the years. However, these treatments may result in infertility or subfertility. Oncologists are considered the gateway for knowledge about cancer and its treatments' effects. Several studies showed that many oncologists do not discuss fertility preservation with their patients. This study aimed to explore the perspective of oncologists in Oman on fertility preservation. METHODS: A cross-sectional study of physicians and surgeons dealing with patients with cancer was conducted from June 2021 to December 2021. A standardized and validated questionnaire was used to collect data. RESULTS: Participants reported that they are knowledgeable about sperm cryopreservation and gonadotropin-releasing hormone agonists use but not other methods of fertility preservation. About 94% of the participants reported that they need more knowledge about fertility preservation. More than half of the participants had never encountered cancer patients who used ovarian cryopreservation, testicular tissue cryopreservation, in vitro fertilization with embryo cryopreservation and oocyte cryopreservation. The majority (78%) agreed that discussing fertility preservation with newly diagnosed cancer patients is a high priority. CONCLUSIONS: Oncologists in Oman are supportive of fertility preservation. The lack of knowledge and unavailability of well-structured fertility preservation services in Oman hinders the initiation of fertility preservation discussions.

Insights into organoid-based modeling of COVID-19 pathology.

Since December 2019, various types of strategies have been applied due to the emergent need to investigate the biology and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to discover a functional treatment. Different disease modeling systems, such as mini-organ technology, have been used to improve our understanding of SARS-CoV-2 physiology and pathology. During the past 2 years, regenerative medicine research has shown the supportive role of organoid modeling in controlling coronavirus disease 2019 (COVID-19) through optimal drug and therapeutic approach improvement. Here, we overview some efforts that have been made to study SARS-CoV-2 by mimicking COVID-19 using stem cells. In addition, we summarize a perspective of drug development in COVID-19 treatment via organoid-based studies.

Teaching, Learning and Assessing Anatomy with Artificial Intelligence: The Road to a Better Future.

Anatomy is taught in the early years of an undergraduate medical curriculum. The subject is volatile and of voluminous content, given the complex nature of the human body. Students frequently face learning constraints in these fledgling years of medical education, often resulting in a spiraling dwindling academic performance. Hence, there have been continued efforts directed at developing new curricula and incorporating new methods of teaching, learning and assessment that are aimed at logical learning and long-term retention of anatomical knowledge, which is a mainstay of all medical practice. In recent years, artificial intelligence (AI) has gained in popularity. AI uses machine learning models to store, compute, analyze and even augment huge amounts of data to be retrieved when needed, while simultaneously the machine itself can be programmed for deep learning, improving its own efficiency through complex neural networks. There are numerous specific benefits to incorporating AI in education, which include in-depth learning, storage of large electronic data, teaching from remote locations, engagement of fewer personnel in teaching, quick feedback from responders, innovative assessment methods and user-friendly alternatives. AI has long been a part of medical diagnostics and treatment planning. Extensive literature is available on uses of AI in clinical settings, e.g., in Radiology, but to the best of our knowledge there is a paucity of published data on AI used for teaching, learning and assessment in anatomy. In the present review, we highlight recent novel and advanced AI techniques such as Artificial Neural Networks (ANN), or more complex Convoluted Neural Networks (CNN) and Bayesian U-Net, which are used for teaching anatomy. We also address the main advantages and limitations of the use of AI in medical education and lessons learnt from AI application during the COVID-19 pandemic. In the future, studies with AI in anatomy education could be advantageous for both students to develop professional expertise and for instructors to develop improved teaching methods for this vast and complex subject, especially with the increasing paucity of cadavers in many medical schools. We also suggest some novel examples of how AI could be incorporated to deliver augmented reality experiences, especially with reference to complex regions in the human body, such as neural pathways in the brain, complex developmental processes in the embryo or in complicated miniature regions such as the middle and inner ear. AI can change the face of assessment techniques and broaden their dimensions to suit individual learners.

Students' Performance in Face-to-Face, Online, and Hybrid Methods of Teaching and Assessment in Anatomy.

In recent times, online teaching and assessment have provided a great opportunity to explore better methods in medical education. There are inconsistent views concerning the effectiveness of online assessment. Hence, the present study aimed to evaluate online teaching and assessment methods in relation to face-to-face methods by comparing students' performances. The students' assessment results in two basic anatomy courses, which are part of the Doctor of Medicine and Biomedical Sciences programs at Sultan Qaboos University, were analysed. We compared the students' mean scores and coefficient of variance in the multiple-choice written exams and the objective structured practical exams during the spring semesters of 2019, 2020, and 2021, containing face-to-face teaching and exams, partial online teaching and online exams, and online teaching and both proctored online and face-to-face exams, respectively. The sudden transition to online teaching and assessment halfway through the semester resulted in higher means and a lower coefficient of variance among students' scores in both theory and practical exams. However, when the fully adopted online method of teaching and assessment was employed, the mean scores decreased, and the coefficient of variance increased to figures close to those witnessed before the pandemic, when teaching and assessment were face-to-face. This trend applied to both the Doctor of Medicine and Biomedical Sciences programs' anatomy courses. The results indicate that online assessment of theoretical and practical anatomical knowledge is comparable to that of face-to-face assessment. However, proper planning and preparedness are mandatory to achieve the desired outcomes.

Human Pluripotent Stem Cells in Reproductive Science-a Comparison of Protocols Used to Generate and Define Male Germ Cells from Pluripotent Stem Cells.

Globally, fertility-related issues affect around 15% of couples. In 20%-30% of cases men are solely responsible, and they contribute in around 50% of all cases. Hence, understanding of in vivo germ-cell specification and exploring different angles of fertility preservation and infertility intervention are considered hot topics nowadays, with special focus on the use of human pluripotent stem cells (hPSCs) as a source of in vitro germ-cell generation. However, the generation of male germ cells from hPSCs can currently be considered challenging, making a judgment on the real perspective of these innovative approaches difficult. Ever since the first spontaneous germ-cell differentiation studies, using human embryonic stem cells, various strategies, including specific co-cultures, gene over-expression, and addition of growth factors, have been applied for human germ-cell derivation. In line with the variety of differentiation methods, the outcomes have ranged from early and migratory primordial germ cells up to post-meiotic spermatids. This variety of culture approaches and cell lines makes comparisons between protocols difficult. Considering the diverse strategies and outcomes, we aim in this mini-review to summarize the literature regarding in vitro derivation of human male germ cells from hPSCs, while keeping a particular focus on the culture methods, growth factors, and cell lines used.

Human induced pluripotent stem cells from two azoospermic patients with Klinefelter syndrome show similar X chromosome inactivation behavior to female pluripotent stem cells.

STUDY QUESTION: Does the X chromosome inactivation (XCI) of Klinefelter syndrome (KS)-derived human induced pluripotent stem cells (hiPSCs) correspond to female human pluripotent stem cells (hPSCs) and reflect the KS genotype? SUMMARY ANSWER: Our results demonstrate for the first time that KS-derived hiPSCs show similar XCI behavior to female hPSCs in culture and show biological relevance to KS genotype-related clinical features. WHAT IS KNOWN ALREADY: So far, assessment of XCI of KS-derived hiPSCs was based on H3K27me3 staining and X-inactive specific transcript gene expression disregarding the at least three XCI states (XaXi with XIST coating, XaXi lacking XIST coating, and XaXe (partially eroded XCI)) that female hPSCs display in culture. STUDY DESIGN, SIZE, DURATION: The study used hiPSC lines generated from two azoospermic patients with KS and included two healthy male (HM) and one healthy female donor. PARTICIPANTS/MATERIALS, SETTING, METHODS: In this study, we derived hiPSCs by reprograming fibroblasts with episomal plasmids and applying laminin 521 as culture substrate. hiPSCs were characterized by karyotyping, immunocytochemistry, immunohistochemistry, quantitative PCR, teratoma formation, and embryoid body differentiation. XCI and KS hiPSC relevance were assessed by whole genome transcriptomics analysis and immunocytochemistry plus FISH of KS, HM and female fibroblast, and their hiPSC derivatives. MAIN RESULTS AND THE ROLE OF CHANCE: Applying whole genome transcriptomics analysis, we could identify differentially expressed genes (DEGs) between KS and HM donors with enrichment in gene ontology terms associated with fertility, cardiovascular development, ossification, and brain development, all associated with KS genotype-related clinical features. Furthermore, XCI analysis based on transcriptomics data, RNA FISH, and H3K27me3 staining revealed variable XCI states of KS hiPSCs similar to female hiPSCs, showing either normal (XaXi) or eroded (XaXe) XCI. KS hiPSCs with normal XCI showed nevertheless upregulated X-linked genes involved in nervous system development as well as synaptic transmission, supporting the potential use of KS-derived hiPSCs as an in vitro model for KS. LIMITATIONS, REASONS FOR CAUTION: Detailed clinical information for patients included in this study was not available. Although a correlation between DEGs and the KS genotype could be observed, the biological relevance of these cells has to be confirmed with further experiments. In addition, karyotype analysis for two hiPSC lines was performed at passage 12 but not repeated at a later passage. Nevertheless, since all XCI experiments for those lines were performed between passage 11 and 15 the authors expect no karyotypic changes for those experiments. WIDER IMPLICATIONS OF THE FINDINGS: As KS patients have variable clinical phenotypes that are influenced by the grade of aneuploidy, mosaicism, origin of the X chromosome, and XCI 'escapee' genes, which vary not only among individuals but also among different tissues within the same individual, differentiated KS hiPSCs could be used for a better understanding of KS pathogenesis. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Knut and Alice Wallenberg Foundation (2016.0121 and 2015.0096), Ming Wai Lau Centre for Reparative Medicine (2-343/2016), Ragnar Söderberg Foundation (M67/13), Swedish Research Council (2013-32485-100360-69), the Centre for Innovative Medicine (2-388/2016-40), Kronprinsessan Lovisas Förening För Barnasjukvård/Stiftelsen Axel Tielmans Minnesfond, Samariten Foundation, Jonasson Center at the Royal Institute of Technology, Sweden, and Initial Training Network Marie Curie Program 'Growsperm' (EU-FP7-PEOPLE-2013-ITN 603568). The authors declare no conflicts of interest.

Hormone Production by Human First-Trimester Gonads in a Functional In Vitro System.

In the past, explant tissue-culture methodologies have been used to grow gonads and study their development. Results from in vitro cultures of human gonads showed limited progress toward gonadal cell differentiation and were focused mainly on germ-cell differentiation. Thus, detailed studies focusing on human first-trimester gonadal tissue functionality in vitro are still missing. In this study we investigated the endocrine function of human first-trimester gonads in vitro. We included 27 female and 28 male gonadal samples, derived from a total of 55 cases, at postconceptional ages of 4.5 to 10.5 weeks. Tissues were cultured using an explant tissue-culture system for 14 days. Assays for testosterone (liquid chromatography-tandem mass spectrometry), anti-Müllerian hormone (AMH; ELISA), and inhibin B (ELISA) were performed using media collected after 7 and 14 days of culture. We demonstrated sex- and age-dependent secretion profiles of testosterone, AMH, and inhibin B in the culture media, which resemble the pattern of hormone production in human gonads in vivo, from the few available studies at the same age range. Our study shows that explant tissue-culture conditions are robust for culture of human first-trimester gonadal somatic cells. Thus, it can be used to study human gonadal development and related diseases as well as the effect of potentially hormone-disturbing substances in human gonads during development. However, detailed molecular studies are needed for better understanding of the mechanistic control of the endocrine function of human first-trimester gonads.

Laminin 521 Stabilizes the Pluripotency Expression Pattern of Human Embryonic Stem Cells Initially Derived on Feeder Cells.

Human embryonic stem (hES) cells represent an important tool to study early cell development. The previously described use of human recombinant laminin (LN) 521 represented a step forward in generating clinically safe culture conditions. To test the short-term effect of LN521 on cultured hES cells, five male hES cell lines were cultured on human foreskin fibroblasts (hFFs), Matrigel, LN521, and LN121 and characterized by qPCR, immunofluorescence analysis, as well as their potential for three-germ layer differentiation. Variations in gene expression related to pluripotency, stemness, and testicular cells at different passages and culture conditions were evaluated by qPCR. All cell lines expressed pluripotency markers at protein and RNA level and were able to differentiate into cell types of the three germ layers after being cultured on LN521 for nine passages. Reduction in variation of pluripotency marker expression could be observed after culturing the cells on LN521 for nine passages. hES cells cultured on LN521 exhibited less differentiation, faster cell growth, and attachment when compared to hES cells cultured on LN121 or Matrigel. Our results indicate a positive effect of LN521 in stabilizing pluripotency gene expression and might be the first step towards more controllable and robust culture conditions for hES cells.

Knock-Out Serum Replacement and Melatonin Effects on Germ Cell Differentiation in Murine Testicular Explant Cultures.

Finding robust culture conditions for in vitro maturation (IVM) of male germ cells is still a challenge. Recently, a testis organ culture method, using Knockout Serum Replacement (KSR), was suggested as a promising approach. However, the efficiency of that model is still not optimal. Hence, we have tried to establish the culture conditions in two laboratories, and to improve the reliability of the culture system to generate mature germ cells. Male mice at three days of age were sacrificed. Testes were cut into small pieces which were cultured atop agarose stands, using Minimum Essential Medium alpha supplemented with different supplements; melatonin, Glutamax, and different concentrations of KSR. The results showed that the duration of culture beyond 18 days had an impact on the number of differentiated germ cells. Supplementation with melatonin and Glutamax revealed a positive influence on the efficiency of male germ cell differentiation in vitro. Furthermore, the results confirmed that KSR had a positive effect on germ cell maturation and testosterone production, with a concentration of at least 10%. In conclusion, this study emphasizes the beneficial role of at least 10% KSR in the IVM of germ cells.

Over Expression of NANOS3 and DAZL in Human Embryonic Stem Cells.

The mechanisms underlying human germ cell development are largely unknown, partly due to the scarcity of primordial germ cells and the inaccessibility of the human germline to genetic analysis. Human embryonic stem cells can differentiate to germ cells in vitro and can be genetically modified to study the genetic requirements for germ cell development. Here, we studied NANOS3 and DAZL, which have critical roles in germ cell development in several species, via their over expression in human embryonic stem cells using global transcriptional analysis, in vitro germ cell differentiation, and in vivo germ cell formation assay by xenotransplantation. We found that NANOS3 over expression prolonged pluripotency and delayed differentiation. In addition, we observed a possible connection of NANOS3 with inhibition of apoptosis. For DAZL, our results suggest a post-transcriptional regulation mechanism in hES cells. In addition, we found that DAZL suppressed the translation of OCT4, and affected the transcription of several genes associated with germ cells, cell cycle arrest, and cell migration. Furthermore, DAZL over expressed cells formed spermatogonia-like colonies in a rare instance upon xenotransplantation. These data can be used to further elucidate the role of NANOS3 and DAZL in germ cell development both in vitro and in vivo.