Two Types of Variational Arteries' Courses From the Superior Mesenteric Artery to Supply the Splenic Flexure: Gross Anatomical Study.

BACKGROUND: Complete mesocolic excision with central vascular ligation is a standard method for managing colon cancer. However, there is no consensus on its procedure, especially for cancer in the splenic flexure of the transverse colon. This is because various types of variational arteries are distributed to the region, and their running course below and near the pancreas leads to difficulty in ligating the artery. OBJECTIVE: To clarify the arterial distribution to the splenic flexure of the transverse colon using cadavers. DESIGN: The arteries in the transverse mesocolon distributed to the colon were dissected in cadavers, and their route was quantitatively visualized using drawing software. SETTINGS: This study was conducted at the Department of Anatomy, Tokyo Medical University. PATIENTS: Sixty cadavers donated to Tokyo Medical University in 2017-2021 were used. MAIN OUTCOME MEASURES: The arterial courses to the splenic flexure of the transverse colon in the mesocolon and their patterns were evaluated. RESULTS: We found 34 variational arteries distributed to the splenic flexure of the transverse colon. Most originated from the superior mesenteric artery and the middle colic artery, with their typical course below the pancreas. We identified another arterial course, crossing the mesocolon away from the pancreas toward the splenic flexure of the transverse colon. Furthermore, the origin of these arteries was not behind the pancreas and can be found in the caudal region of the pancreas. LIMITATIONS: We cannot discuss how the arteries within the transverse mesocolon are observed by CT examination. CONCLUSIONS: This study showed 2 types of arterial courses (below the pancreas and within the mesocolon) toward the splenic flexure of the transverse colon for the first time. In the latter case, the complete mesocolic excision with central vascular ligation is likely performed more easily than in the former. See Video Abstract. DOS TIPOS DE RECORRIDO VARIACIONAL DE LA ARTERIA DESDE LA ARTERIA MESENTRICA SUPERIOR PARA IRRIGAR EL NGULO ESPLNICO ESTUDIO ANATMICO MACROSCPICO: ANTECEDENTES:La escisión mesocólica completa con ligadura vascular central es un método estándar para el cáncer de colon. Sin embargo, no hay consenso sobre su procedimiento, especialmente para el cáncer en el ángulo esplénico del colon transverso. Esto se debe a que varios tipos de arterias variacionales se distribuyen en la región, y su recorrido por debajo y cerca del páncreas dificulta la ligadura de la arteria.OBJETIVO:Este estudio tuvo como objetivo aclarar la distribución arterial al SF del colon transverso utilizando cadáveres.DISEÑO:Las arterias en el mesocolon transverso distribuidas al colon fueron disecadas en cadáveres, y su ruta fue visualizada cuantitativamente utilizando un software de dibujo.AJUSTES:Este estudio se realizó en el Departamento de Anatomía de la Universidad Médica de Tokio.PACIENTES:Se utilizaron sesenta cadáveres donados a la Universidad Médica de Tokio en 2017-2021.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluaron los cursos arteriales al ángulo esplénico del colon transverso en el mesocolon y sus patrones.RESULTADOS:Encontramos 34 arterias variacionales distribuidas al ángulo esplénico del colon transverso. La mayoría se originaron en la arteria mesentérica superior y la arteria cólica media, con su trayecto típico por debajo del páncreas. Identificamos otro curso arterial, cruzando el mesocolon alejándose del páncreas hacia el ángulo esplénico del colon transverso. Además, el origen de estas arterias no estaba detrás del páncreas y se pueden encontrar en la región caudal del páncreas.LIMITACIONES:No podemos discutir cómo se observan las arterias dentro del mesocolon transverso mediante un examen de tomografía computarizada.CONCLUSIONES:Este estudio mostró por primera vez dos tipos de trayectos arteriales (por debajo del páncreas y dentro del mesocolon) hacia el ángulo esplénico del colon transverso. En el último caso, es probable que la escisión mesocólica completa con ligadura vascular central se realice más fácilmente que en el primero. (Traducción-Dr. Aurian Garcia Gonzalez ).

Neurotransmission, Vasculogenesis, and Osteogenesis Activities are Altered in the Aging Temporomandibular Joint of the Senescence-Accelerated Prone 8 Mouse Model.

BACKGROUND: Alterations in neurotransmission, vasculogenesis, and osteogenesis pathways that may play pivotal roles in age-related changes in the temporomandibular joint (TMJ) are poorly understood. PURPOSE: This study aimed to measure the associations between gene and protein profiles in senescence-accelerated prone 8 (SAMP8) mice. STUDY DESIGN: The investigators designed and used 3 groups of 2 mouse models: 1) early aging SAMP8 at 24 weeks of age and control SAMR1 at 12 and 24 weeks (each stage n = 12). PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The independent variable was investigated using 3 mouse models: an early aging mouse model and a control mouse model (12 and 24 weeks). MAIN OUTCOME VARIABLE(S): The primary outcome variables were CGRP, VEGF-A, CD31, LYVE-1, osteocalcin, osteopontin, type I and II collagen, and MMP-2. The secondary outcome variables were histological characteristics. COVARIATES: Not applicable. ANALYSES: The gene and protein expression profiles of neurotransmitters, vasculogenesis, and osteogenesis were identified by quantitative real-time polymerase chain reaction and dot blot analysis, respectively. The cellular localization of these events was verified by in situ hybridization and immunohistochemistry. Bivariate statistics were computed for each of the outcome variables. Statistical significance was set to a P value < .05. RESULTS: The expression of CGRP mRNA in the bony mandibular condyle (BMC) of SAMP8 mice (SAMP8, 3.3 ± 0.39 vs SAMR1, 0.001 ± 0.0001) was high at 24 weeks of age (24 weeks) (P < .001). Higher numbers of cells positive percentage for CGRP (MF, SAMP8, 28.67 ± 1.60 vs SAMR 1, 6.36 ± 1.10; CMC, 27.5 ± 2.12 vs 9.00 ± 1.21; BMC, 31.31 ± 2.81 vs 7.85 ± 1.14) and VEGF-A (MF, 34.43 ± 2.45 vs 14.01 ± 1.28; MD, 32.69 ± 1.86 vs 8.00 ± 0.91; CMC, 36.60 ± 2.05 vs 14.19 ± 1.25 BMC 36.49 vs 12.59 ± 1.41) antibodies were found in the 24 weeks TMJ (P < .01). CONCLUSIONS AND RELEVANCE: The neurotransmitter, vasculogenesis, and osteogenesis pathways are associated with TMJ aging in the SAMP8 mouse model. In the future, the SAMP8 mouse model may prove to be a robust model for identifying molecular and biochemical events underlying the effects of feeding, occlusal changes, and tooth loss in the aging TMJ.

Expression patterns of sex steroid receptors in developing mesonephros of the male mouse: three-dimensional analysis.

The androgen pathway via androgen receptor (AR) has received the most attention for development of male reproductive tracts. The estrogen pathway through estrogen receptor (ESR1) is also a major contributor to rete testis and efferent duct formation, but the role of progesterone via progesterone receptor (PGR) has largely been overlooked. Expression patterns of these receptors in the mesonephric tubules (MTs) and Wolffian duct (WD), which differentiate into the efferent ductules and epididymis, respectively, remain unclear because of the difficulty in distinguishing each region of the tracts. This study investigated AR, ESR1, and PGR expressions in the murine mesonephros using three-dimensional (3-D) reconstruction. The receptors were localized in serial paraffin sections of the mouse testis and mesonephros by immunohistochemistry on embryonic days (E) 12.5, 15.5, and 18.5. Specific regions of the developing MTs and WD were determined by 3-D reconstruction using Amira software. AR was found first in the specific portion of the MTs near the MT-rete junction at E12.5, and the epithelial expression showed increasing strength from cranial to the caudal regions. Epithelial expression of ESR1 was found in the cranial WD and MTs near the WD first at E15.5. PGR was weakly positive only in the MTs and cranial WD starting on E15.5. This 3-D analysis suggests that gonadal androgen acts first on the MTs near the MT-rete junction but that estrogen is the first to influence MTs near the WD, while potential PGR activity is delayed and limited to the epithelium.

Expression of neurotransmitters, vasculogenesis markers and myosin heavy chain isoforms in the masseter muscle of senescence-accelerated mouse prone 8 mice.

BACKGROUND: Learning and memory deficits and pathologic changes in the hippocampus caused by toothlessness and soft diet feeding are related to reduced masseter muscle (MM) function. OBJECTIVE: Myosin heavy chain (MyHC) isoform expression in the MM also changes under different chewing conditions. The neurotransmitter calcitonin gene-related peptide (CGRP) and vascular endothelial growth factor A (VEGF-A) are involved in MM formation. However, the relationship between CGRP, VEGF-A and MyHC isoforms in the MM in the senescence-accelerated mouse prone 8 (SAMP8) strain, a model of learning and memory deficits, remains unclear. METHODS: Changes in CGRP, VEGF-A, vasculogenesis marker and MyHC isoform mRNA expression in the MMs of ageing SAMP8 and senescence-accelerated mouse resistant 1 (SAMR1) mice was investigated through quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. RESULTS: qRT-PCR revealed obviously high CGRP levels in the SAMP8 mouse MM (p < .001). MyHC-IId/x mRNA expression in the MM was higher in 24-week-old SAMP8 mice than 24-week-old SAMR1 mice (p < .001) but lower in slow-MyHC SAMP8 mice than SAMR1 mice (p < .001). CGRP mRNA was observed on the muscle fibres of the SAMP8 mouse MM but not the SAMR1 mouse MM through in situ hybridization. Principal component analysis (PCA) revealed strong positive contributions of SAMP8-MyHC-IId/x, SAMP8-CGRP, SAMR1-MyHC-emb, SAMR1-CGRP, SAMR1-VEGF-A, SAMR1-CD31, SAMP8-VEGF-A, and SAMP8-CD31 in the MM at 12 and 24 weeks. CONCLUSION: Calcitonin gene-related peptide is also key for the MyHC-IId/x and slow-MyHC patterns in the MMs of SAMP8 mice.

Three-dimensional analysis of mesonephric tubules remodeling into efferent tubules in the male mouse embryo.

BACKGROUND: Spermatozoa are transported to the epididymal duct through efferent tubules. Although the origin of the efferent tubules is thought to be mesonephric tubules (MTs), their detailed developmental process, for example, where the rete testis and efferent tubules are connected, is unclear. We investigated the structural changes of the MTs in the male mouse embryo using a three-dimensional reconstruction method. RESULTS: Three to six MTs were connected to the Wolffian duct, and some of them branched, resulting in five to nine tips. Rete cells contacted the three to six tips. The MTs showed a folded shape when the gonadal fate was determined. After the testis development started, they became short and straight but emerged as long and twisting by birth. Before birth, the efferent duct was composed of MTs and a cranial portion of the folded Wolffian duct. CONCLUSIONS: The contact between the rete testis and efferent tubules is possibly established at the tip of each MT. The MTs regress after gonadal fate is determined but is remodeled to the twisting efferent tubules by birth. The efferent tubules are composed of the MTs but also a cranial portion of the folded Wolffian duct in the mouse.

Structural and CBCT analysis of mandibular canal microvessels expressing neurotransmitters in human cadavers.

PURPOSE: This study focused on the detailed structure of microvessels of the neurotransmitter-positive vasa nervorum of the inferior alveolar nerve, vein, and artery in the mandibular canal (MC) to obtain information for improved safety in dental treatments. We also observed the detailed structure of the MC from the mental foramen to the mandibular foramen using cone-beam computed tomography (CBCT). METHODS: In this study, mandibles from 45 sides of 23 human cadavers aged 76-104 years were examined by microscopy, immunohistochemistry, and CBCT analysis. These data were further evaluated by principal component analysis (PCA). RESULTS: The microvessels of the vasa nervorum with calcitonin gene-related peptide- and neuropeptide Y-positive reactions were classified into 5 types: large (4.19%, 28/667); irregular large (7.35%, 49/667), numerous intermediate (29.23%, 195/667), irregular intermediate (29.23%, 195/667), and scattered fine (30.0%, 200/667) microvessels. The MC showed various structures from the 3rd molar to the premolars and was also classified into three types, including complete (57.0%, 228/400), partial (33.8%, 135/400), and unclear (9.2%, 37/400), from the mandibular foramen to the mental foramen. PCA results revealed that developed capillaries were mainly localized in the molar region. CONCLUSIONS: Fine microvessels of the vasa nervorum expressing neurotransmitters are present from the molar to premolar region, which is key information for mandibular dental treatments. The different microvessel structures also indicate differences in specific characteristics between dentulous and edentulous cadavers regarding oral surgical and implant treatments.

Three-dimensional structure of the facial canal and related blood vessels and nerves in the temporal bone.

PURPOSE: There are only limited anatomical data on nerves, veins, and arteries in the temporal bone. More detailed anatomical data are required to improve planning of treatments targeting the temporal bone region. Herein, we performed a detailed analysis of the facial canal (FC) and the related carotid artery and vein. METHODS: We examined the bony structure of the middle ear and FC, jugular foramen, and carotid canal in 30 Japanese elderly donor cadavers. Three-dimensional reconstruction of the canal structure was achieved using cone beam computed tomography, while macroscopic and histological analyses were also performed. RESULTS: The FC form was classified as either straight (28%) or bent (72%). There were significant differences in the diameter of the FC and the distance between the internal jugular vein, other FC branches, and the FC. Principal component analysis (PCA) was performed for the FC using 29 factors. Two principal components significantly explained 30.9% (component 1, 18.6%; component 2, 12.3%) of the FC. Histological observation showed numerous ganglion cells and shrunken neurons in the geniculate ganglion of the facial nerve of elderly samples. CONCLUSION: FC diameter is an important contributor to the relationship between the FC and the jugular foramen. The FC and the internal jugular vein are located close to each other, which is useful information for the trans-canal surgery of the otology. Furthermore, the geniculate ganglion contains numerous ganglion cells and shrunken neurons, which may affect the FC structure during bone matrix remodeling with aging.

The interrelationship between three-dimensional foot mobility and bodyweight bearing.

[Purpose] To clarify the three-dimensional nature of foot mobility and its interrelationships within the foot due to bodyweight bearing. [Participants and Methods] Data regarding left foot mobility due to body weight bearing were collected from 31 healthy adults. Foot shape differences while sitting and standing, and their interrelationship were examined. The same examiner reapplied the landmark stickers when misaligned during measurement position changes. [Results] The foot length, heel width, forefoot width, hallux valgus angle, and calcaneus eversion angle were significantly larger in the standing than in sitting position. The digitus minimus varus angle was significantly smaller in the standing than in sitting position. The medial and lateral malleoli, navicular, and dorsum of the foot were displaced medially and inferiorly; the other indices, except for the midfoot, were displaced anteriorly. The interrelationships within the foot showed a positive correlation between the calcaneus eversion angle and the medial displacement of the medial and lateral malleoli, navicular, and dorsum of the foot points. There was a negative correlation between the calcaneus eversion angle and inferior displacement of the medial malleolus, navicular, and dorsum of the foot. [Conclusion] The intra-foot coordination relationship in response to bodyweight bearing was clarified.

Relationship between the thoracic asymmetry in standing position and the asymmetry of ankle moment in the frontal plane during gait.

[Purpose] We aimed to investigate the relationship of thoracic asymmetry in standing position with asymmetry of the internal ankle moment in the frontal plane during gait. [Participants and Methods] The following measurements were recorded in 22 healthy adult males using a 3D motion analyzer and force plates: thoracic lateral deviation, asymmetrical ratios of the upper and lower thoracic shape, internal ankle moment in the frontal plane, mediolateral deviations of the center of mass and center of pressure. [Results] In the standing position, the thorax was deviated to the left relative to the pelvis, and the upper and lower thoracic shapes were asymmetrical. During gait, significant lateralities were observed in the internal ankle moment in the frontal plane, mediolateral deviations of the center of mass and the center of pressure. Significant positive correlations were observed between the asymmetrical ratio of the lower thoracic shape and both the asymmetry of the internal ankle moment in the frontal plane and the mediolateral deviation of the center of pressure. [Conclusion] These results suggest that thoracic asymmetry is associated with mediolateral control of the ankle during gait.

Relationship between the bilateral ratios of the thoracic shape and electromyographic activity of the thoracic and lumbar iliocostalis muscles during thoracic lateral translation.

[Purpose] This study aimed to determine the relationship between thoracic lateral deviation, the bilateral ratio of the thoracic shape, and the bilateral ratio of the thoracic and lumbar iliocostalis muscles during resting sitting and thoracic lateral translation. [Participants and Methods] We included 23 healthy adult males in the study. The measurement tasks were resting sitting and thoracic lateral translation relative to the pelvis. The thoracic lateral deviation and bilateral ratio of the upper and lower thoracic shapes were measured using three-dimensional motion capture. The bilateral ratio of the thoracic and lumbar iliocostalis muscles were measured using the surface electromyographic recording. [Results] The bilateral ratio of the lower thoracic shape was significantly positively correlated with the thoracic translation distance and the bilateral ratio of the thoracic and iliocostalis muscles. In addition, the bilateral ratio of the thoracic iliocostalis muscles was significantly negatively correlated with the bilateral ratios of the lower thoracic shape and lumbar iliocostalis muscles. [Conclusion] Our findings showed that the asymmetry of the lower thoracic shape is associated with left lateral deviation of the thorax at rest and thoracic translation distance. In addition, the thoracic and lumbar iliocostalis muscle activity differed between the left and right translations.

Relationship between scapular elevation exercises with different alignments and activity of the trapezius and levator scapulae muscles.

[Purpose] This study aimed to examine whether scapular elevation exercises in sitting positions with different alignments lead to contractions of the trapezius and levator scapulae muscles. [Participants and Methods] The participants were 25 males, measured in four sitting positions with different alignments. Spine alignment was assessed by measuring the head protrusion, upper thoracic spine tilt, and pelvic tilt angles. Upper limb alignment was evaluated using the scapula tilt angle, scapula rotation angle, and distance between scapular spinous processes. Scapular elevation exercises were measured, and the thickness of the trapezius and levator scapulae muscles were measured in resting and elevated positions, with changes in muscle thickness. [Results] The trapezius muscle thickness was greater in the sitting position with less thoracic spine tilt and scapula tilt angles. Conversely, the levator scapulae muscle thickness was greater in the sitting position with more thoracic spine tilt and scapula tilt angles. [Conclusion] Scapular elevation exercises induce separate contractions of the trapezius and levator scapulae muscles by modifying the alignment of the spine and upper limbs.

Microenvironment for spermatogenesis and sperm maturation.

The male reproductive system consists of testes, a series of ducts connecting the testes to the external urethral orifice, accessory sex glands, and the penis. Spermatogonial stem cells differentiate and mature in testes and epididymides, and spermatozoa are ejaculated with exocrine fluids secreted by accessory sex glands. Many studies have clarified the detailed structure and function of the male reproductive system, and have shown that various biologic controls, including genomics, epigenetics, and the neuroendocrine-immune system regulate proliferation, differentiation, and maturation of germ cells. In other words (1) genetic deletion or abnormalities, (2) aberration of DNA methylation and histone modifications, as well as small RNA dysfunction, and (3) neuroendocrine-immune disorders are involved in functional failure of the male reproductive system. In this article, we review these three factors for germ cell microcircumstance, especially focused on the immunoendocrine environment. In particular, the relation between factors protecting germ cells with strong auto-immunogenicity and opposite factors compromising this protection are discussed. Reductions in sperm count, concentration, and semen quality are serious problems in developed countries, although the causes are complex and remain unclear. The accumulation of basic knowledge regarding the structure, function, and regulation of the male reproductive system under various experimental conditions will be important to resolve these problems.

Comparative anatomy on the development of sperm transporting pathway between the testis and mesonephros.

The male genital tract is diverse among vertebrates, but its development remains unclear, especially in the rete region. In this study, we investigated the testis-mesonephros complex of rabbit, chicken, and frog (Xenopus tropicalis) by immunohistochemistry for markers such as Ad4BP/Sf-1 (gonadal somatic and rete cells in mammals) and Pax2 (mesonephric tubules), and performed a three-dimensional reconstruction. In all investigated animals, testis cords were bundled at the mesonephros side. Rete cells positive for Ad4BP/Sf-1 (rabbit) or Pax2 (chicken and frog) were clustered at the border region between the testis and mesonephros. The cluster possessed two types of cords; one connected to the testis cords and the other to the mesonephric tubules. The latter rete cords were contiguous to Bowman's capsules in rabbit and chicken but to nephrostomes in frog. In conclusion, this study showed that mammals, avian species, and frogs commonly develop the bundle between the testis cords (testis canal) and the cluster of rete cells (lateral kidney canal), indicating that these animals share basic morphogenesis in the male genital tract. The connection site between the rete cells and mesonephric tubules is suggested to have changed from the nephrostome to the Bowman's capsule during vertebrate evolution from anamniote to amniote.

GIT1 is an untolerized autoantigen involved in immunologic disturbance of spermatogenesis.

Male haploid cells, spermatids and spermatozoa, that appear after the establishment of immune tolerance express novel cell surface and intracellular proteins that can be recognized as foreign antigens by the self-immune system. However, these germ cells do not normally evoke a pathological immune response. The immune-privileged micro-circumstance in testis involving the blood-testis-barrier formed by Sertoli cells protects these germ cells from autoimmune attack. We recently found that immunization with heat shock protein family A member 4-like (HSPA4L), one of the new differentiation antigens of haploid cells, induced experimental autoimmune orchitis (EAO) in A/J male mice. In this study, we focused on G protein-coupled receptor kinase interacting protein-1 (GIT1), another haploid cell-specific differentiation antigen, to investigate whether GIT1 is a target autoantigen for EAO induction. GIT1 emulsified with complete Freund's adjuvant was injected subcutaneously into the mice inguinal region once on day 0 and again on day 14, and the optimum condition of EAO induction was determined. Mice immunized with 200 µg GIT1 showed significantly higher incidence of EAO than that of immunization with other concentrations. In particular, significant lymphocytic inflammation and extensive aspermatogenesis were observed in these mice at 120 days after the first immunization. These findings indicate that GIT1 is also a target antigen that induces EAO, like HSPA4L.

Three-dimensional analysis and in vivo imaging for sperm release and transport in the murine seminiferous tubule.

Spermatozoa released from Sertoli cells must be transported to the epididymis. However, the mechanism of the luminal flow in seminiferous tubules has remained unclear to date. Therefore, in this study, we investigated luminal flow and movements in the seminiferous tubules by three-dimensional analysis and in vivo imaging. Serial 5-µm-thick mouse testicular sections at 50-µm-intervals were prepared and stained by Periodic Acid-Schiff-hematoxylin. After three-dimensional reconstruction of the seminiferous tubules, the localization of the released spermatozoa and the stages observed in the sections were recorded in each reconstructed tubule. Luminal movements in the seminiferous tubules were observed by in vivo imaging using a fluorescent-reporter mouse and two-photon excitation microscopy system. Spermatozoa without contact to the seminiferous epithelium were not accumulated toward the rete testis. Additionally, such spermatozoa were found on their way not only to the most proximal rete testis but also a more distant rete testis from any stage VIII seminiferous epithelia. In vivo imaging demonstrated that the direction of the flagella of spermatozoa attached to the seminiferous epithelium was repeatedly reversed. The epithelium at the inner curve of the seminiferous tubule was shaken more actively and had fewer spermatozoa attached compared with the epithelium at the outer curve. Our results hence suggest that the luminal flow in the seminiferous tubules is repeatedly reversed and that this physical force helps spermatozoa to be released from Sertoli cells. In brief: Spermatozoa are released from Sertoli cells and flow in the seminiferous tubule to the rete testis. Our results suggest that the luminal flow in the tubules is repeatedly reversed and that this physical force helps spermatozoa release from the Sertoli cells.

Sacroiliac innervation.

PURPOSE: To investigate the innervation pattern of the sacroiliac region, especially with regard to the sacroiliac joint (SIJ). Dorsal SIJ innervation was analyzed and described. Our main hypothesis was that nerves reach the SIJ dorsally, passing ligamental compartments, as this would explain dorsal SIJ pain. METHODS: To examine sacroiliac innervation, we followed the nerves in over 50 specimens over several years. Plastinated slices were evaluated, nerves in the region were stained histologically, and the data were summarized as 3D models. RESULTS: The Rami communicans and posterior branches of the spinal nerves and their branches that form a dorsal sacral plexus and communicating branches, together with corresponding vessels, were observed to form neurovascular bundles embedded by tiny fatty connectives in gaps and tunnels. Branches of L5-S1 pass the inner sacroiliac ligaments (the interosseous sacroiliac ligament and axial interosseous ligament). The outer sacroiliac ligaments (posterior sacroiliac ligaments, long posterior sacroiliac ligament, sacrotuberal ligament, thoracolumbar fascia) are passed by the S1-S4 branches. However, although the paths of these nerves are in the direction of the SIJ, they do not reach it. It is possible that impingement of the neurovascular bundles may result in pain. Moreover, the gaps and tunnels connect to the open dorsal SIJ. CONCLUSION: Our findings suggest that Bogduk's term "sacroiliac pain" correlates to "sacroiliac innervation", which consists of "inner-" and "outer sacroiliac ligament innervation", and to ventral "SIJ pain". The watery gaps and tunnels observed could play a significant role in innervation and thus in the origins of SIJ pain. LEVEL OF EVIDENCE: Individual cross-sectional studies with consistently applied reference standard and blinding.

Connection between seminiferous tubules and epididymal duct is originally induced before sex differentiation in a sex-independent manner.

BACKGROUND: Spermatozoa in mammals develop in seminiferous tubules in a testis and are transported through the male reproductive tract. Their developmental origins are, however, different from each other; the seminiferous tubules are testicular (gonadal) structure but the subsequent ducts stem from the mesonephros. Although some mechanisms should function for the connection between these ducts, there are few reports on them. In the present study, basic information such as timing, localization, and cell types involved in the connection was obtained by sequential immunohistochemistry. RESULTS: At the time when the undifferentiated gonad differentiates into the testis or ovary, Adrenal-4 binding protein/steroidogenic factor-1 (Ad4BP/SF-1)-positive gonadal cells were noted in the mesonephric tubules (MT) in both sexes. At an earlier stage, although Ad4BP/SF-1-positive coelomic epithelial cells were adjacent to the MT, a basal membrane around them was not observed. CONCLUSIONS: The connection between the testis cords and MT is suggested to be induced between Ad4BP/SF-1-positive gonadal cells and the MT before sex differentiation in a sex-independent manner.

Neonatal maternal separation causes decreased numbers of sertoli cell, spermatogenic cells, and sperm in mice.

Neonatal maternal separation is an experimental model used to evaluate the effects of toxic stress in neonates, or early life stress. Although various physiological and psychological stresses during childhood have been reported, the effects of neonatal maternal separation on the male reproductive system remain unclear. Therefore, the present study evaluated the effects of neonatal maternal separation on the male reproductive system. In neonatal male ICR mice, maternal separation was performed for 0.5, 1, 2, and 4 hours/day, from postnatal day 1 to 10. At 10 weeks of age, the neonatal maternal separation mice exhibited decreases in both testicular weight and epididymal sperm number, along with various testicular morphological changes involving germ cells, Sertoli cells, and interstitial cells. Notably, neonatal maternal separation mice showed decreased numbers of Sertoli cells. Animals subjected to 0.5-, 1-, and 2-h/day neonatal maternal separation exhibited decreases in serum levels of testosterone but not in those of gonadotropin (luteinizing hormone and follicle-stimulating hormone). Together, these data showed that neonatal maternal separation in male mice causes decreased Sertoli cell numbers following puberty, resulting in subsequent decreased spermatogenic activity.

Effects of the posterior pelvic tilt sitting posture on thoracic morphology and respiratory function.

[Purpose] We investigated how differences in pelvic angle in the posterior pelvic tilt sitting posture simultaneously affect the thoracic morphology and the respiratory function. [Participants and Methods] The participants were 18 healthy young males. We positioned the pelvis at 0°, 10°, 20°, and 30° of posterior tilt, following which the thoracic expansion volume ratio, thoracic spine tilt angle, and respiratory function were measured. We calculated the thoracic volume and thoracic spine tilt angle by measuring the amount of displacement of reflective markers attached to the thoracic area using the Vicon MX 3D-analysis system. Respiratory function was measured by spirometry. [Results] The expansion volume ratio decreased significantly in response to 10-30° posterior pelvic tilt sitting at the mid-thorax and 30° posterior pelvic tilt sitting at the lowest thorax. The upper thoracic spine level showed a change in anterior tilt at 10-30° posterior pelvic tilt sitting, whereas the lower thoracic spine level showed a change in posterior tilt at 30° posterior pelvic tilt sitting. Respiratory function was significantly lower at 30° posterior pelvic tilt sitting than at 0° posterior pelvic tilt sitting. A positive correlation between thoracic expansion volume ratio and respiratory function was found at 30° posterior pelvic tilt sitting. [Conclusion] Changes in thoracic spine tilt angle due to posterior pelvic tilt sitting may restrict the expansion of thoracic motion during respiration, thereby affecting respiratory function.

Pelvic collateral pathway during endovascular aortoiliac aneurysm repair with internal iliac artery interruption: a retrospective observational study.

BACKGROUND: Ipsilateral branches of the deep femoral artery (DFA) are qualitatively identified as collateral arteries based on angiography after internal iliac artery (IIA) interruption. The purpose of this study was to quantitatively identify the major collateral pathway after unilateral IIA interruption during endovascular aortoiliac aneurysm repair to preserve the pelvic circulation and reduce the risk of ischemic complications. METHODS: The study population included 28 patients (mean age 76.3 years) with aortoiliac aneurysm who underwent endovascular aneurysm repair with unilateral IIA interruption from August 2012 to January 2020. The diameters of the bilateral preoperative and postoperative DFA, lateral femoral circumflex artery (LFCA), medial femoral circumflex artery (MFCA) and obturator artery (ObA) were measured on contrast-enhanced computed tomography using a 3-dimensional image analysis system. The measured values were evaluated and analyzed with a repeated measures two-way analysis of variance and Dunnett's test. RESULTS: The postoperative diameters of the MFCA (P = 0.051) and ObA (P = 0.016) were observed to be larger than the preoperative diameters. Such increases in the MFCA (P < 0.001) and ObA (P < 0.001) diameters were only found to be significant on the unilateral side of the IIA interruption, and the diameter of the ipsilateral LFCA (P < 0.001) was also found to have significantly increased in size. However, no significant arterial extension was found on the contralateral side. CONCLUSIONS: The ipsilateral MFCA-ObA pathway might therefore be a major collateral pathway arising from the DFA to preserve pelvic circulation after unilateral IIA interruption.