A comparison of pre- and post-clinical education learning preferences among medical students who elected to dissect compared to those who did not during the COVID-19 pandemic.

Anatomy instructional methods varied widely during the COVID-19 pandemic and programs are assessing innovations for retention. Learning preferences were assessed among medical students dichotomized as elective dissectors (ED) or non-dissectors (ND) during the COVID-19 partial re-opening in 2020 (preclinical) and again in 2022 after clinical exposure (post-clinical) to assess the viability of elective dissection post-pandemic. A mixed-method approach was used for the assessment of test scores, learning preference surveys, learning activities rankings, and thematic analyses. No significant differences occurred in anatomy examination scores. Dissection was considered useful by both preclinical groups but significantly more so by ED, while the presence of an instructor was significantly preferred by ED although a majority of ND agreed. Elective dissection was significantly preferred by ND but also by a large minority of ED students. Pre- and post-clinical ND believed that elective dissection offered more academic flexibility, did not hinder clinical learning, and did not negatively impact medical education. The corresponding ED stated that confidence improved, clinical experiences were enhanced, and dissection was irreplaceable. Preclinical ND preferred self-learning, while ED students preferred online learning, but these differences largely disappeared post-clinically. Learning activity rankings were not significantly different among all groups (ND, ED, preclinical, and post-clinical). A hybrid laboratory with a virtual learning environment ranked highest across groups and preferences increased over time suggesting that students benefited from this instructional method during clinical exposure. The absence of laboratory experience ranked lowest, and preference decreased over time suggesting that anatomy dissection is valued.

Extended reality visualization of medical museum specimens: Online presentation of conjoined twins curated by Dr. Jacob Henle between 1844-1852.

Background: The purpose of this study is to characterize a full-term conjoined twins' cadaver curated by Dr. Jacob Henle sometime between 1844 and 1852 and demonstrate digital distribution of an old and rare medical museum specimen using an extended reality (XR) model workflow. Methods: The cadaver (Preparation 296) is in the Department of Anatomy and Cell Biology at the University of Heidelberg. An XR display workflow comprises image capture, segmentation, and visualization using CT/MR scans derived from the cadaver. Online radiology presentation to medical students focuses on diagnostic characteristics of anatomical systems depicted with XR models. Results: Developmental defects in Preparation 296 include duplicated supradiaphragmatic structures and abnormal osteological features. Subdiaphragmatically, the gut is continuous on the right, but terminates at the distal esophagus on the left. One large liver occupies the abdomen with one spleen located on the left side. Observations suggest duplication of the primitive streak and separate notochords rostrally. Duplication occurs near the yolk sac and involves midgut formation while secondary midline fusion of the upper extremities and ribs likely results from the proximity of the embryos during development. Medical students access the model with device agnostic software during the curricular topic "Human Body Plan" that includes embryology concepts covering mechanisms of twinning. Conclusions: The workflow enables ease-of-access XR visualizations of an old and rare museum specimen. This study also demonstrates digital distribution and utilization of XR models applicable to embryology education.

The insulin-like growth factor (IGF)-I E-peptides are required for isoform-specific gene expression and muscle hypertrophy after local IGF-I production.

Insulin-like growth factor I (IGF-I) coordinates proliferation and differentiation in a wide variety of cell types. The igf1 gene not only produces IGF-I, but also generates multiple carboxy-terminal extensions, the E-peptides, through alternative splicing leading to different isoforms. It is not known if the IGF-I isoforms share a common pathway for their actions, or if there are specific actions of each protein. Viral administration of murine IGF-IA, IGF-IB, and mature IGF, which lacked an E-peptide extension, was utilized to identify IGF-I isoform-specific responsive genes in muscles of young growing mice. Microarray analysis revealed responses that were driven by increased IGF-I regardless of the presence of E-peptide, such as Bcl-XL. In contrast, distinct expression patterns were observed after viral delivery of IGF-IA or IGF-IB, which included matrix metalloproteinase 13 (MMP13). Expression of Bcl-XL was prevented when viral administration of the IGF-I isoforms was performed into muscles of MKR mice, which lack functional IGF-I receptors on the muscle fibers. However, MMP13 expression persisted under the same conditions after viral injection of IGF-IB. At 4 mo after viral delivery, expression of IGF-IA or IGF-IB promoted muscle hypertrophy, but viral delivery of mature IGF-I failed to increase muscle mass. These studies provide evidence that local production of IGF-I requires the E-peptides to drive hypertrophy in growing muscle and that both common and unique pathways exist for the IGF-I isoforms to promote biological effects.

Stems of the Arabidopsis pin1-1 mutant are not deficient in free indole-3-acetic acid.

The pin1-1 mutant of Arabidopsis thaliana has been pivotal for studies on auxin transport and on the role of auxin in plant development. It was reported previously that when whole shoots were analysed, levels of the major auxin, indole-3-acetic acid (IAA) were dramatically reduced in the mutant, compared with the WT (Okada et al. 1991). The cloning of PIN1, however, provided evidence that this gene encodes a facilitator of auxin efflux, raising the question of how the pin1-1 mutation might reduce overall IAA levels as well as IAA transport. We therefore re-examined IAA levels in individual parts of pin1-1 and WT plants, focusing on inflorescence stems. Our data show that there is in fact no systemic IAA deficiency in the mutant. The previously reported difference between mutant and WT may have been due to the inclusion of reproductive structures in the WT harvest: we show here that the inflorescence itself contains high levels of IAA. We reconcile the normal IAA levels of pin1-1 inflorescence stems with their (previously-reported) reduced ability to transport IAA by presenting evidence that the auxin in mutant stems is not imported from their apical portion. Our data also indicate that levels of another auxin, indole-3-butyric acid (IBA), are very low in stems of the genotypes used in this study.

Using CT to diagnose traumatic lumbar hernia.

OBJECTIVE: The objective of this study was to determine the CT findings of traumatic lumbar hernia in 15 patients and to discuss the mechanism and treatment of injury. CONCLUSION: CT can reveal traumatic lumbar hernia and show both the anatomy of disrupted muscular layers and the presence of herniated intraabdominal viscera or retroperitoneal fat.

CT detection of serious internal and skeletal injuries in patients with pelvic fractures.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the percentage of patients with known pelvic fractures who have additional findings of intraabdominal injury, as diagnosed at abdominal computed tomography (CT), and to determine if patients with specific types or patterns of fractures are more likely to have additional injuries. MATERIALS AND METHODS: The authors reviewed the medical records of 200 consecutive patients (125 women, 75 men; age range, 4-86 years) who had been admitted to a level 1 trauma center with osseous pelvic injury secondary to blunt trauma and who had undergone abdominal CT examinations. Abdominal CT findings in these patients were classified as negative, positive, or minimal and correlated with mechanism of pelvic fracture. RESULTS: Sixty-five (32%) of the 200 patients had negative CT findings, 43 (22%) had findings attributable to the trauma but required no follow-up, and 92 (46%) had positive findings that required nonsurgical management or exploratory laparotomy. Additional pelvic fractures were identified in 63 (32%) patients. The highest prevalence of additional injuries was in patients with Malgaigne fractures (four of 15, 27%) or bilateral pubic rami fractures (six of 18, 33%). CONCLUSION: CT examinations revealed that 135 (68%) of 200 patients with pelvic fractures secondary to blunt trauma had concomitant internal or skeletal injuries and that 92 (46%) patients had injuries severe enough to require nonsurgical management or exploratory laparotomy. Patients with bilateral pubic rami fractures or Malgaigne fractures were particularly prone to additional injuries; therefore, abdominal CT examinations are recommended in these patients.

Evaluation of the portal venous system: complementary roles of invasive and noninvasive imaging strategies.

Evaluation of the portal venous system is required in several clinical circumstances, including before and after liver transplantation, before creation of a transjugular intrahepatic portosystemic shunt, in the clinical setting of bowel ischemia, or to evaluate varices. Several noninvasive modalities (magnetic resonance [MR] imaging and MR angiography, computed tomography [CT], and ultrasound [US]) are available for evaluation of the portal venous system in addition to the invasive angiographic methods. In most clinical circumstances, either CT or MR imaging and MR angiography in combination with US of the liver vasculature will allow complete evaluation of the portal venous system. Invasive evaluation of the portal venous system is necessary when results of the noninvasive tests disagree or are inconclusive. Angiography may also be indicated whenever noninvasive tests indicate occlusion of the portal venous system, as this is often a crucial clinical question and false-positive results can occur with the noninvasive tests.

The natural history of portal hypertension after transjugular intrahepatic portosystemic shunts.

BACKGROUND & AIMS: The effects of transjugular intrahepatic portosystemic shunt (TIPS) on portal hemodynamics, esophageal and gastric varices, and hepatic function have not been fully defined. The aim of this study was to define prospectively the effects of TIPS on portal pressures and flow, variceal resolution, and hepatic function. METHODS: Pressure and flow measurements were made by angiography and Doppler sonography, respectively. Varices were assessed by endoscopy and angiography. Liver functions were evaluated by a battery of tests. RESULTS: In 100 consecutive subjects, mean portosystemic gradient decreased from 24 to 11 mm Hg (means) (P < 0.001) after TIPS. Recurrent portal hypertension caused by stent thrombosis (n = 5), stent retraction (n = 2), and stent stenosis (n = 51) occurred at 6 months but, by year 5, was not present in survivors (n = 0 of 8). Fundic gastric varices failed to resolve in 6 of 12 cases. Systemic venous pressures of >15 mm Hg, stent dysfunction, and continued alcoholism were risk factors for recurrent hemorrhage. Angiography was superior to endoscopy, which was superior to Doppler sonography for detection of recurrent portal hypertension. Progressive liver failure occurred in 8 patients. CONCLUSIONS: Recurrent portal hypertension caused by stent stenosis occurs commonly in the first 2 years after TIPS. Fundic gastric varices often fail to disappear after TIPS. The effects of TIPS on liver function are unpredictable.

Enhancing ascites: an aid to CT diagnosis.

Enhancement of ascitic fluid on delayed contrast-enhanced CT has been described as a potential pitfall in diagnosis. We present a case in which the phenomenon was beneficial to diagnosis. Enhancement of ascites was useful in delineating the entire extent of a cystic pelvic mass. We also discuss probable molecular and histologic mechanisms responsible for this unique type of enhancement.

Enzymatic digestion of the urethra after pancreatic transplantation: a case report.

The most common method of exocrine drainage in pancreatic transplantation is urinary drainage. With the shift from enteric drainage and duct occlusion techniques, there has been a concomitant shift from intraabdominal to urological complications. We present a case in which a simultaneous pancreas-kidney (SPK) transplant recipient developed urethral disruption and associated bladder outlet obstruction 11 months following surgery.

Anatomic CT demonstration of the peritoneal spaces, ligaments, and mesenteries: normal and pathologic processes.

Computed tomography (CT) has become increasingly useful in the detection of intraabdominal disease. Owing to the widespread use of CT, it is essential that radiologists have a thorough understanding of the peritoneal spaces and the ligaments and mesenteries that form their boundaries. The majority of ligaments and mesenteries in the abdomen are formed from remnants of the ventral and dorsal mesenteries, which suspend the primitive gut. Unlike the abdominal ligaments, the pelvic ligaments are mainly formed by reflections of peritoneum over the pelvic organs or structures. The mesenteries and ligaments form the boundaries of the peritoneal spaces; this knowledge aids in localizing fluid collections, allowing the differential diagnosis to be narrowed. The ability to localize fluid collections accurately is also important if percutaneous or surgical drainage is to be performed. In addition, neoplasms can be more accurately staged when the pathway of spread through adjacent ligaments and mesenteries is understood.

Performance of the internal jugular vein after functional neck dissection.

The objective of this study was to assess internal jugular vein performance after functional neck dissection in routine and extended head and neck surgical procedures, including bilateral neck dissections, treatment of radiation failures, and those combined with microvascular free grafts. Because the indications for functional neck dissection in our practice have increased. It is important to assess the use of the procedure in these circumstances. Although previous work has suggested the patency of the internal jugular vein after functional neck dissection, actual flow rates have not been investigated. The function of the dissected internal jugular vein was analyzed with duplex ultrasound at least 4 weeks after treatment. Maximal venous flow rates were evaluated. The results of this study will be presented and discussed.

Well-imaged large vessel vasculitis attributed to anticardiolipin antibody.

OBJECTIVE: We report a case of large vessel vasculitis, compare imaging techniques, and briefly review the literature. METHODS: Anticardiolipin antibody titers, acute-phase response, and ischemic symptoms in a 50-year-old man admitted for treatment of vasculitis-related ischemia of the fingers were monitored over a 14-month period. Images from serial magnetic resonance angiography (MRA) were compared with images from conventional arteriography in the evaluation of peripheral arterial circulation. RESULTS: The acute-phase response and anticardiolipin antibody levels were found to vary in parallel with slow resolution of ischemic symptoms following monthly treatment with pulse methylprednisolone and cyclophosphamide. CONCLUSION: Attribution of ischemic symptoms to anticardiolipin antibody is supported by the correlation of anticardiolipin antibody titers, acute-phase response parameters, and ischemic symptoms. The serial images from MRA demonstrate its usefulness as a noninvasive tool for followup studies of both large and medium-sized vessels affected by vasculitis.