Prominent caudal shift of the lumbar plexus roots in spines with 18 thoracolumbar vertebrae.

PURPOSE: It remains unclear whether concomitant changes in the thoracolumbar (TL) vertebrae and lumbar plexus roots seen in experimental embryology are present in humans with different vertebral formulas, particularly in humans with 18 TL vertebrae. We thus investigated the human lumbar plexus root changes occurring in spines with an additional TL vertebra (18TL). METHODS: The lumbosacral plexus was macroscopically dissected in TL anomaly cases found in 161 computed tomography examinations. TL anomalies were distinguished as simple abnormalities in total TL count and abnormal TL trade-offs, i.e., exchanges between the last thoracic and first lumbar vertebrae, and were analyzed separately. RESULTS: One additional TL vertebra (7C_18TL_5S) was observed in 4/159 cases (2.5%), excluding cases with cervical and sacral abnormalities. Different from the unclear shifts of nerve roots in cases with 16TL and 17TL trade-offs, the 18TL trade-off tended to involve a caudal shift at the cranial limit, without event change at the caudal limit. In addition, only one nerve segment shift was reconfirmed with a change in two vertebral segments from 16 to 18 TL vertebrae. CONCLUSIONS: We revealed that concomitant changes in the lumbar plexus roots and vertebrae in humans with 18TL vertebrae may become more pronounced than those in humans with 16 or 17TL vertebrae, by approaching the typical mammalian TL formula (19TL). This study showed that the TL formula can be used to estimate changes in the lumbar plexus roots, which may assist in the planning of nerve-sparing spinal and pelvic surgery.

Morphological analysis of neck muscle nerves and neurons in cats.

Previous studies have failed to show morphological differences between neck muscle alpha and gamma motor fibers or alpha and gamma motoneurons. The present study aimed to investigate the morphological features of neck muscle motor nerves and motoneurons in cats. To determine the morphological features of peripheral motor fibers, the value of the outer contours of each fiber was converted into a perfect circle after ganglionectomy to remove sensory fibers, and the fiber diameters were calculated based on their circumferences. The sizes of neck motor fibers in the peripheral nerves had an evident bimodal distribution into small and large fiber groups, as depicted in histograms. The sizes of small and large motor fibers ranged from 2 to 12 µm and from 12 to 40 µm, respectively. The small fiber group is likely to correspond to gamma motor fibers and the large fiber group to alpha motor fibers. The morphological features of neck muscle motoneurons sectioned in the horizontal plane were examined using the horseradish peroxidase (HRP) retrograde labeling technique. The diameters of the biventer cervicis and complexus motoneurons had bimodal distributions. The inflection point between the small and large diameter population was 28 µm for the biventer cervicis and 26 µm for the complexus. We also observed that larger neurons displayed more dendrites. In conclusion, we could identify morphological differences likely to correlate with alpha and gamma motoneurons in both neck muscle peripheral nerves and neck motoneurons.

Integrated anatomical practice combining cadaver dissection and matched cadaver CT data processing and analysis.

PURPOSE: With the increasing significance of diagnostic imaging in clinical practice, long-term anatomical education and training is required to ensure that students can reliably distinguish anatomical structures and interpret images. To improve students' motivation and prospects for learning imaging anatomy, we developed an integrated anatomical practice program combining cadaveric dissection with cadaver CT data processing and analysis during undergraduate students' dissection courses. METHODS: Workstations imported with post-mortem CT data of dissected cadavers and various forms of clinical CT/MRI data were set in the dissection room. Medical students had free access to the imaging data during cadaver dissection, and they were challenged to process and analyze the data for submission of voluntary imaging reports on their topics of interest. Finally, we surveyed the integrated anatomical education of 481 medical students. RESULTS: The positive response rate to the integrated anatomical practice was 74.9%, and 79.4% of the students answered that this form of practice offered a suitable introduction to anatomical imaging. The usefulness of this approach in understanding the 2- to 3D arrangement of the human body and enhancing interest in anatomy was also confirmed. The submission rate of voluntary imaging reports also increased annually and is currently 97.4%. CONCLUSION: Our integrated anatomical practice only allowed students to actively browse CT images and facilitated imaging processing and analysis of their region of interest. This practice may improve students' long-term ability to analyze images and deepen their understanding. A competitive imaging contest may help improve students' motivation when they begin learning imaging anatomy.

A successful case of "temporary endoluminal bypass technique" using a guide extension catheter during thrombolysis for acute limb ischemia in the non-stenting zone.

It is still difficult to treat acute limb ischemia (ALI) in the non-stenting zone such as the popliteal artery. We describe a temporary endoluminal bypass technique for ALI in the non-stenting zone using a guide extension catheter. An 83-year-old female was admitted and diagnosed with ALI in her left leg. The angiogram showed a thrombotic obstruction of the left popliteal artery. Aspiration and dilation by angioplasty could not revascularize. Although Fogarty thrombectomy can be applicable, we avoided it because of its risk of complications and performed a temporary endoluminal bypass technique. After evaluating the occluded lesion by intravascular ultrasound, we delivered a guide extension catheter to fully cover it. Because it played the role of an endoluminal bypass, the blood flow to the distal tibial arteries could be confirmed in the angiogram. A thrombolytic drug was administered intra-arterially for the whole day, and the angiogram showed a reduction of the thrombus on postoperative day (POD) 1. On POD 2, the blood flow was maintained without flow limitation even after removing the catheter. Finally, she was discharged without any complications. This technique might be an alternative in cases of failed conventional treatments for ALI although further investigation needs to be undertaken. .

First in situ 3D visualization of the human cardiac conduction system and its transformation associated with heart contour and inclination.

Current advanced imaging modalities with applied tracing and processing techniques provide excellent visualization of almost all human internal structures in situ; however, the actual 3D internal arrangement of the human cardiac conduction system (CCS) is still unknown. This study is the first to document the successful 3D visualization of the CCS from the sinus node to the bundle branches within the human body, based on our specialized physical micro-dissection and its CT imaging. The 3D CCS transformation by cardiac inclination changes from the standing to the lying position is also provided. Both actual dissection and its CT image-based simulation identified that when the cardiac inclination changed from standing to lying, the sinus node shifted from the dorso-superior to the right outer position and the atrioventricular conduction axis changed from a vertical to a leftward horizontal position. In situ localization of the human CCS provides accurate anatomical localization with morphometric data, and it indicates the useful correlation between heart inclination and CCS rotation axes for predicting the variable and invisible human CCS in the living body. Advances in future imaging modalities and methodology are essential for further accurate in situ 3D CCS visualization.

Postmortem evaluation of neuromuscular damages more extensive than the surgical intervention area after iliac crest bone graft.

Several complications may occur following iliac bone grafting, one of the common sites for autologous bone harvesting. Of these, it is difficult to localize the damage in neurological complications due to the presence of several nerves in a similar distribution area with variations among individuals. To minimize these complications, conventional clinical anatomical studies using normal human cadavers have estimated the theoretical neurological damage area corresponding to the surgical intervention area. We report a case of neuromuscular damage in a 93-year-old woman who had an iliac crest defect after a bone graft, based on the virtual and physical dissections with histological confirmations.In this study, the patient was confirmed to have severe neuromuscular complications with major complications including a hernia protruding through the iliac defect. One of the two ilioinguinal nerves was extracted with the hernia sac through the iliac defect, and its distal part was completely damaged. The iliohypogastric nerve, which was far from the defect foramen, also showed remarkable fibrosis and demyelination, affected by the degeneration of the transversus abdominis muscles.The present anatomical findings show that the area of eventual neuromuscular damage should be estimated to larger than the conventionally predicted area of direct nerve damage, which is usually concomitant with the surgical intervention area.

Successful wound healing of refractory digital ulcer in patient with systemic sclerosis by Waon therapy.

The treatment of digital ulcer (DU) in systemic sclerosis (SSc) has not been established. A 77-year-old female with a refractory DU in SSc on the right foot was transferred to our hospital. Wound healing had not been achieved despite several endovascular treatments (EVT) and minor amputations. We started Waon therapy 5 days per week as an adjunct therapy. She was placed in a far-infrared-ray dry sauna maintained at 45 °C for 15 min, and was subsequently kept to rest with soothing warmth using a blanket for additional 30 min outside the room. Gradually, the wound had become smaller and the skin perfusion pressure (SPP) had increased. The increase of the blood flow to the wound could be observed in the angiogram on day 109. An additional EVT on day 109 also accelerated wound healing. Finally, wound healing was completely achieved without additional amputations on day 173. In this presented case, Waon therapy contributed to increase of the blood flow to the wound, evidenced by SPP value. Waon therapy may serve as an effective adjunct therapy of DU in SSc. .

The phenotypic morphology of human lumbar plexus roots associated with changes in the thoracolumbar vertebral count and trade-off.

This study investigated the developmental basis for the human phenotypic morphology of the interaction between the vertebrae and the nerve plexus by evaluating changes in the human lumbar plexus according to various thoracolumbar formulas. The dissection found that the changes in lumbar nerve roots reported by experimental embryology studies to be concomitant with thoracolumbar trade-off, i.e., a change in vertebrae from thoracic to lumbar with no change in the overall thoracolumbar count, were not apparent in humans with the usual 17 or mutant 16 thoracolumbar vertebrae. When vertebral changes in two segments were examined by comparing spines with a reduced thoracolumbar count of 16 to those with an increased count of 18, this tended to show only a single-segment caudal shift of the lumbar plexus. We cannot provide evidence for the phylogenetic difference in the concomitant changes of lumbar nerves and vertebrae, but comparisons between experimental rodents and humans highlighted fewer and shorter lumbar vertebra and more complicated lumbar plexus in humans. Therefore, these multiple differences may contribute to a human phenotypic morphology that is not evident in the concomitant transformation of vertebrae and lumbar nerves reported in experimental rodents.

Internal structure of the rat subiculum characterized by diverse immunoreactivities and septotemporal differences.

The subiculum is one of output structures of the hippocampal formation and plays a pivotal role in learning and memory. Because its morphological features are less investigated than those of the hippocampus proper, we explored the internal structure of the rat subiculum using immunohistochemistry. The septal subiculum comprised one region, whereas the temporal subiculum consisted of two subregions, the distal subiculum (Sub1) and proximal subiculum (Sub2). The Sub2 contained four layers: (1) molecular layer, (2) superficial cell layer containing three types of pyramidal neurons immunolabeled for either nitric oxide synthase, Purkinje cell protein 4 (PCP4), or calbindin, (3) middle cell layer where boutons labeled for zinc transporter 3 and those for vesicular glutamate transporter 2 accumulated in the proximal and distal part of the Sub2, respectively, and (4) deep cell layer containing PCP4-positive pyramidal cells, apical dendrites of which showed a characteristic bundling pattern. These features were not observed in either the Sub1 or septal subiculum. There were clear species differences between rats and mice in labeling patterns of pyramidal cells. Morphological differences along the septotemporal axis might be the basis of the functional diversity of the subiculum, such as spatial memory and emotional memory processed at different septotemporal levels.

Derived muscle arrangements and their shared innervation patterns of external and internal cheek pouches in rodents.

Cheek pouches have evolved from the oral cavity in rodents and act as temporary food storage repositories. There are two types of opening, internal and external. Details about the complex cutaneous muscles controlling the pouches have still not been fully elucidated. To understand the shared and derived traits of the muscles surrounding the cheek pouch and their innervation, we carried out an evolutionary morphological study using two desert kangaroo rats (Dipodomys deserti) and three plains pocket gophers (Geomys bursarius) from each of the two families equipped with external cheek pouches, and four Syrian hamsters (Mesocricetus auratus) with internal cheek pouches. The most conspicuous derived trait of the muscles between the external and internal cheek pouches, the sphincter sacculi, surrounds almost all of the edge of the outer entrance of the pouch. It is present in both species with external pouches, but not in hamsters, which have internal pouches. Our neurological findings demonstrate that most pouch muscles are innervated by both the facial and the cervical nerves, regardless of the pouch type. In these dually innervated muscles, the ventromedial part of the muscles tends to be innervated dominantly or uniquely by the cervical nerves, which usually enter from the superficial or lateral aspect. As a trait shared with the cervical nerves innervating the propatagial muscles in aerodynamic mammals such as bats and flying squirrels, and panniculus carnosus in most mammals, our neurological evidence suggests that the cervical nerve has the potential to innervate derived cutaneous muscles in the cervicofacial region.

Data on the origin, course and distribution of the artery to the human atrioventricular node.

This article presents data on the anatomical variation of the origin, course and distribution of the artery to the atrioventricular node in humans. The findings hold clinical significance for coronary intervention, coronary angiography and cardiac pathology in cases of sudden cardiac death. For further interpretation and discussion, the original research article 'Clarifying the anatomy of the atrioventricular node artery' by Kawashima and Sato (2018) can be referred [1].

Clarifying the anatomy of the atrioventricular node artery.

BACKGROUND: Reports of conduction abnormalities necessitating permanent pacemaker implantation due to atrioventricular node artery injury and increasing evidence of stenosis of the atrioventricular node artery in cases of sudden death are of unsolved clinical importance. Unfortunately, technical issues associated with physical and virtual dissections of the atrioventricular conduction axis make it difficult to accurately assess its arterial supply. METHODS: We used a specialized dissection technique to gather anatomical information on the atrioventricular node artery and described them using attitudinally appropriate terminology. RESULTS: The mean number of atrioventricular node artery branches was 1.6 in 103 submacroscopic examinations and 2.3 in 17 histological reconstructions. The artery had 5 origins in the modified AHA anatomy guidelines: distal RCA (#3), 10.4%; right posterior interventricular artery (#4PI), 7.3%; proximal RCA posterolateral branch (proximal #4PL), 76.8%; distal RCA posterolateral branch detouring the coronary sinus (distal #4PL), 1.8%; distal LCX (#13), 3.7%. Histological examination revealed that most atrioventricular node arteries immediately left the distal compact node (71.8%), suggesting that they supply mainly the proximal part of the AV conduction axis. The artery to the atrioventricular node tended to originate from the medial and atrial aspect of RCA posterolateral branch, and supplied adjacent structures within the inferior pyramidal space before entering the compact atrioventricular node. CONCLUSIONS: Based on the visualisation of the atrioventricular conduction axis and its arterial supply, we herein provide the 'gold standard' for understanding the origin, course and distribution of the artery to the atrioventricular node.

Association of Epicardial, Visceral, and Subcutaneous Fat With Cardiometabolic Diseases.

BACKGROUND: Excess of visceral fat is a central factor in the pathogenesis of metabolic syndrome (MetS) and atherosclerosis. However, little is known about how much epicardial fat affects cardiometabolic disorders in comparison with visceral or subcutaneous fat.Methods and Results:Participants suspected as having angina pectoris underwent cardiac computed tomography (CT) imaging. Of them, 374 subjects were analyzed the association of clinical characteristics and CT-based fat distribution measured as epicardial fat volume (EFV), visceral fat area (VFA), and subcutaneous fat area (SFA). EFV was highly associated with VFA (R=0.58). Serum adiponectin was significantly decreased in high VFA subjects (VFA ≥100 cm2) and was also reduced in the high EFV group (EFV ≥80 cm3). Among the low VFA groups, the numbers of subjects with diabetes and coronary atherosclerosis were increased in high EFV group. Among the low EFV groups, the numbers of subjects with diabetes, hyperuricemia, and coronary atherosclerosis were increased among the high VFA subjects. In an age-, sex-, and body mass index (BMI)-adjusted model, EFV was associated with dyslipidemia and MetS, and VFA was significantly associated with hypertension, dyslipidemia, MetS, and coronary atherosclerosis, while SFA was not related with coronary risks and atherosclerosis. CONCLUSIONS: Epicardial fat accumulation may be a risk for coronary atherosclerosis in subjects without visceral fat accumulation. Visceral fat is the strongest risk for cardiometabolic diseases among the 3 types of fat depot.

The morphological characterization of orientation-biased displaced large-field ganglion cells in the central part of goldfish retina.

The vertebrate retina has about 30 subtypes of ganglion cells. Each ganglion cell receives synaptic inputs from specific types of bipolar and amacrine cells ramifying at the same depth of the inner plexiform layer (IPL), each of which is thought to process a specific aspect of visual information. Here, we identified one type of displaced ganglion cell in the goldfish retina which had a large and elongated dendritic field. As a population, all of these ganglion cells were oriented in the horizontal axis and perpendicular to the dorsal-ventral axis of the goldfish eye in the central part of retina. This ganglion cell has previously been classified as Type 1.2. However, the circuit elements which synapse with this ganglion cell are not yet characterized. We found that this displaced ganglion cell was directly tracer-coupled only with homologous ganglion cells at sites containing Cx35/36 puncta. We further illustrated that the processes of dopaminergic neurons often terminated next to intersections between processes of ganglion cells, close to where dopamine D1 receptors were localized. Finally, we showed that Mb1 ON bipolar cells had ribbon synapses in the axonal processes passing through the IPL and made ectopic synapses with this displaced ganglion cell that stratified into stratum 1 of the IPL. These results suggest that the displaced ganglion cell may synapse with both Mb1 cells using ectopic ribbon synapses and OFF cone bipolar cells with regular ribbon synapses in the IPL to function in both scotopic and photopic light conditions.

Cell type-specific effects of p27KIP1 loss on retinal development.

BACKGROUND: Cyclin-dependent kinase (CDK) inhibitors play an important role in regulating cell cycle progression, cell cycle exit and cell differentiation. p27KIP1 (p27), one of the major CDK inhibitors in the retina, has been shown to control the timing of cell cycle exit of retinal progenitors. However, the precise role of this protein in retinal development remains largely unexplored. We thus analyzed p27-deficient mice to characterize the effects of p27 loss on proliferation, differentiation, and survival of retinal cells. METHODS: Expression of p27 in the developing and mature mouse retina was analyzed by immunohistochemistry using antibodies against p27 and cell type-specific markers. Cell proliferation and differentiation were examined in the wild-type and p27-deficient retinas by immunohistochemistry using various cell cycle and differentiation markers. RESULTS: All postmitotic retinal cell types expressed p27 in the mouse retinas. p27 loss caused extension of the period of proliferation in the developing retinas. This extra proliferation was mainly due to ectopic cell cycle reentry of differentiating cells including bipolar cells, Müller glial cells and cones, rather than persistent division of progenitors as previously suggested. Aberrant cell cycle activity of cones was followed by cone death resulting in a significant reduction in cone number in the mature p27-deficient retinas. CONCLUSIONS: Although expressed in all retinal cell types, p27 is required to maintain the quiescence of specific cell types including bipolar cells, Müller glia, and cones while it is dispensable for preventing cell cycle reentry in other cell types.

Anatomical visualization of neural course and distribution of anterior ascending aortic plexus.

The aim of this study was to document the detailed anatomy of neural course and distribution on the anterior ascending aorta, to identify the high and low density areas of the anterior ascending aortic plexus for further understandings in cardiovascular surgery. The embalmed hearts of 42 elderly individuals were submacroscopically and microscopically examined, after excluding any that were macroscopically abnormal. With its origins in the anterior ascending aortic plexus, the right coronary plexus substantially innervated the right coronary artery, the right atrium and ventricle, and the sinus node. The intensive neural area extending from 10 mm lateral to the interatrial groove below the pericardial reflection as far as the right coronary artery opening contained almost all the right coronary plexus in 61.3% of patients, and more than 40.9% of the total nerve volume of the anterior ascending aortic plexus. Our findings suggest that the most superior and lateral area on the ascending aorta show the lowest neural density of right coronary component in the anterior ascending aortic plexus and the high density areas are invisible in right lateral field of view as seen in the right trans-axillary MICS approach.