Objectives:To estimate normal linear dimensions and volume of spleen in Jordanians using ultrasonography, and to correlate splenic volume with age and body parameters: height, weight, body surface area (BSA), and body mass index (BMI).Methods:A prospective pilot study was conducted on 205 volunteers (115 males and 90 females) not known to have any conditions likely to be associated with splenomegaly. The study was performed at the Radiology Department, Jordanian University Hospital, Amman, Jordan, between December 2013 and August 2014. All linear dimensions of spleen were measured, and splenic volume (index) was calculated using the standard prolate ellipsoid formula (length × width × depth × 0.523). The splenic volume was then analyzed with age and body parameters using the Pearson’s correlation coefficient.Results:The mean (± SD) splenic dimensions were 10.72±1.37 cm in length, 7.40±1.52 cm in width, 4.40±1.47 cm in depth, and 184.15±79.56 cm3 in volume. Men had larger spleens than women (p<0.0001). Age had no significant effect on spleen volume (r=0.11, p=0.12). There was a significant moderate positive correlation (p<0.0001), using Pearson’s correlation coefficient, between the spleen volume, and other parameters (height, weight, BSA, and BMI), with correlation coefficients exceeding 0.3.Conclusion:A local reference of spleen dimensions was established with a different range of values reported previously.

SUMMARY:The foramen magnum is morphometrically typified by two perpendicular diameters and a distinct margin. This important anatomical landmark is subject to high interindividual variation. The objective of this study was to evaluate the dimensions and morphology of the foramen magnum in a Jordanian population. In this retrospective study, 247 individuals were consecutively sampled using the institutional picture archiving and communication system. The anteroposterior and transverse diameters of the foramen magnum were measured; the foramen magnum index was calculated; and, the shape of the foramen magnum was visually assessed. The sex-pooled anteroposterior and transverse diameters were 35.1 ± 3.2 mm and 29.3 ± 2.5 mm, respectively. The sex-pooled foramen magnum index was 1.20 ± 0.10. The diameters were significantly different (P<0.001) and positively correlated (r=0.52, P<0.001). Participant age was negatively correlated with the anteroposterior (r s =-0.15, P=0.02) and transverse (r s =-0.14, P=0.03) diameters. After controlling for participant age, there was a statistically significant difference in the anteroposterior diameter (P<0.001), the transverse diameter (P<0.001), and the foramen magnum index (P=0.02) between sexes. The foramen magnum was most commonly irregular in shape (36 % of all cases). In contrast to previous studies, we report, for the first time, a negative correlation between age and the diameters of the foramen magnum. In addition, a predominance of irregularly shaped foramen magnum was found. The finding makes an already heterogenous group of published data even more variable, prompting reconsideration of the role of visual assessment in morphometric studies.

The relative importance of ATP as a functional sympathetic neurotransmitter in blood vessels has been shown to be increased when the level of preexisting vascular tone or pressure is increased, in studies carried out in rat mesenteric arteries. The aim of the present study was to determine whether tone influences the involvement of ATP as a sympathetic cotransmitter with noradrenaline in another species. We used the porcine perfused mesenteric arterial bed and porcine mesenteric large, medium and small arteries mounted for isometric tension recording, because purinergic cotransmission can vary depending on the size of the blood vessel. In the perfused mesenteric bed at basal tone, sympathetic neurogenic vasocontractile responses were abolished by prazosin, an α 1 -adrenoceptor antagonist, but there was no significant effect of α,β-methylene ATP, a P2X receptor-desensitizing agent. Submaximal precontraction of the mesenteric arterial bed with U46619, a thromboxane A 2 mimetic, augmented the sympathetic neurogenic vasocontractile responses; under these conditions, both α,β-methylene ATP and prazosin attenuated the neurogenic responses. In the mesenteric large, medium and small arteries, prazosin attenuated the sympathetic neurogenic contractile responses under conditions of both basal and U46619-raised tone. α,β-Methylene ATP was effective in all of these arteries only under conditions of U46619-induced tone, causing a similar inhibition in all arteries, but had no significant effect on sympathetic neurogenic contractions at basal tone. These data show that ATP is a cotransmitter with noradrenaline in porcine mesenteric arteries; the purinergic component was revealed under conditions of partial precontraction, which is more relevant to physiological conditions.

Objectives To assess the medical students' satisfaction and knowledge attainment through distant learning during the COVID-19 pandemic. Methods This is a cross-sectional, self-reported, questionnaire-based study that was conducted at the School of Medicine at the University of Jordan in April 2020. The targeted population was the students at the school of medicine. An online questionnaire was created using Google Forms. Satisfaction and knowledge attainment among students were assessed using independent-samples t -test. Results A total of 1000 medical students completed the survey, 506 (50.6%) basic science students and 494 (49.4%) were clinical science students. 655 (65.5%) of all students were either satisfied or neutral with e-learning. 63.6% of basic science students and 59.5% of clinical students stated that they gained and understood knowledge in the same way as or better than they did before initiation of exclusive e-learning. Satisfaction and knowledge gain were significantly affected by student preparedness (p < 0.000), teacher performance (p < 0.000), and website accessibility (p < 0.000). Conclusion Transition from traditional in-class teaching to distant learning, whether full or blended, is an inevitable step. In our sample, students were generally satisfied with e-learning and the knowledge attained using it. There was a significant relation between satisfaction and attainment and preparedness of students, teachers, and the medical school.

Purpose Peripapillary retinal nerve fiber layer (pRNFL) thickness is subject to high variability. Normative values of pRNFL thickness remain undocumented in the Middle East. The aim of our study is to assess the normative values of pRNFL thickness in a Middle Eastern population. Methods A retrospective chart review of 74 patients was conducted. Outpatients who had presented to the ophthalmology clinic at the Jordan University Hospital between January 2016 and July 2018 were consecutively sampled. Measurements had been recorded using Fourier-domain optical coherence tomography. Multivariable regression models were developed to generate predicted normative values with adjustments to candidate confounders. Results The mean global pRNFL thickness was 99 ± 11 μm. The mean quadrantic pRNFL thickness increased from the nasal quadrant (75 ± 16 μm) to the temporal (82 ± 20 μm), superior (114 ± 20 μm), and inferior (125 ± 20 μm) quadrants. Gender and eye sidedness did not contribute to the variability in pRNFL thickness. The relationship between aging and pRNFL thinning is independent of diabetes mellitus type 2 and systemic hypertension. Both systemic conditions significantly predicted pRNFL changes despite negative fundoscopic findings. Conclusions Our set of predicted normative data may be used to interpret measurements of pRNFL thickness in Middle Eastern patients. Our findings suggest that systemic conditions with potential ocular manifestations may require consideration in predictive models of pRNFL thickness, even in the absence of gross fundoscopic findings. Normative data from additional Middle Eastern populations are required to appraise our models, which adjust for common clinical confounders.

Backgrounds The coronavirus disease-2019 (COVID-19) pandemic with increasing morbidity and mortality has impacted the lives of the global population, including medical education. With the return of on-site medical education in Jordan, it is important to know whether this would pose any risk of COVID-19 infection in medical students. Objective To investigate COVID-19 infection infection rates among medical students and whether there is difference between preclinical and clinical students’ infection rate. Methods The study is a cross-sectional study, designed to (1) determine the incidence of COVID-19 in clinical and preclinical medical students (2) determine if there is a difference in infection rates between clinical and preclinical students. The study was situated at the University of Jordan and its affiliated hospitals. Data were collected from the 4 th of December 2020 till the 17th of February 2021through a structured web-based questionnaire. Results A total of 1,830 responses were retrieved. Thirty-nine percent were males, and (61.5%) were females. Overall, 237(13%) of students reported testing positive for COVID-19 infection by PCR, of which 123 were clinical students (15.2%) and 114 were pre-clinical students (11.2%), representing a relative risk of 1.36 of COVID-19 infection among clinical students compared to pre-clinical students. This difference is statistically significant ( P = 0.010). Rates of COVID-19 in females 13%; CI 7.5,18.4), were very close to those of males (12.9%; 95% CI 6.0,19.8). Positive COVID-19 cases peaked in November and October forming 36.3% and 32.9% of the cases, respectively. Conclusion The incidence of positive COVID-19 tests was found to be higher among clinical students as compared to pre-clinical students. Commitment to general health safety precautions did not appear to be protective enough for clinical students. It is fundamental that additional strategies, including access to vaccines, are set, and deficiencies in current protections are identified to maintain students’ safety and well-being.

Background: The COVID-19 pandemic highlighted the necessity of e-learning, which has been integrated in education worldwide at varying degrees. The University of Jordan has started introducing e-learning in its curriculum. However, the COVID-19 pandemic accelerated the process. This study aims to assess the satisfaction and knowledge attainment of the medical students through distant learning during the COVID-19 pandemic.Methods: This is a cross-sectional, self-reported, questionnaire-based study that was conducted at the School of Medicine at the University of Jordan in April 2020. The targeted population was the students at the school of medicine throughout the basic and clinical years of study. Results: 506 of the 1000 student participants are basic science students (BSS) and 494 are clinical science students (CS), 65.5% of all students were either satisfied, or neutral with e-learning. The most popular devices used to connect to the internet are the mobile phone, and the laptop. Streaming (Zoom and Skype) video conference platforms are used by 60% of students. Conclusion: Transition from traditional in-class teaching to distant learning, whether full or blended, is an inevitable step. It is not a lockdown redemption plan instead a step that needs commitment from the teaching institutions, the teachers, and the students.

Sexual dimorphism exists at all levels of the nervous system. These sex differences could underlie genderrelated differences in behavior and neuropsychological function, as well as the gender differences in the prevalence of various mental disorders such as autism, attention deficit disorders, and schizophrenia. Myelination, on the other hand, is a unique cellular process that can have a dramatic impact on the structure and physiology of an axon and its surrounding tissue. The corpus callosum (CC) is the largest of the brain commissures, which connects the cerebral cortices of the two hemispheres, and provides interhemispheric connectivity for information transfer and processing between cortical regions. Variation in the axonal properties of CC will alter the interhemispheric connectivity. The CC consists of myelinated and unmyelinated axons, glial cells and blood vessels. Several functional studies have reported that the function of CC is associated with its axons density and myelination properties. The sexual dimorphism in the axonal content of the CC has always been controversial; hence, the aim of this study was to analyze the differences in axons' diameter and myelin sheath thickness of the CC between male and female rats. For this purpose, five pairs of adult male and female rats were perfused and the CC were removed and sectioned. Four sections from different subregions of the corpus callosum that represent the genu, anterior body, posterior body, and splenium of the CC were stained and electron microscopic images were captured using stereological guidelines. Later, the axons diameter and myelin sheath thickness for each subregion were calculated and compared between males and females. Our preliminary findings of the present study indicated region specific differences in the myelinated axon thickness and diameter in the CC between male and female rats.