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1.
Proc Natl Acad Sci U S A ; 119(30): e2202125119, 2022 07 26.
Article in English | MEDLINE | ID: mdl-35862451

ABSTRACT

Protein kinase A (PKA) directly phosphorylates aquaporin-2 (AQP2) water channels in renal collecting ducts to reabsorb water from urine for the maintenance of systemic water homeostasis. More than 50 functionally distinct PKA-anchoring proteins (AKAPs) respectively create compartmentalized PKA signaling to determine the substrate specificity of PKA. Identification of an AKAP responsible for AQP2 phosphorylation is an essential step toward elucidating the molecular mechanisms of urinary concentration. PKA activation by several compounds is a novel screening strategy to uncover PKA substrates whose phosphorylation levels were nearly perfectly correlated with that of AQP2. The leading candidate in this assay proved to be an AKAP termed lipopolysaccharide-responsive and beige-like anchor protein (LRBA). We found that LRBA colocalized with AQP2 in vivo, and Lrba knockout mice displayed a polyuric phenotype with severely impaired AQP2 phosphorylation. Most of the PKA substrates other than AQP2 were adequately phosphorylated by PKA in the absence of LRBA, demonstrating that LRBA-anchored PKA preferentially phosphorylated AQP2 in renal collecting ducts. Furthermore, the LRBA-PKA interaction, rather than other AKAP-PKA interactions, was robustly dissociated by PKA activation. AKAP-PKA interaction inhibitors have attracted attention for their ability to directly phosphorylate AQP2. Therefore, the LRBA-PKA interaction is a promising drug target for the development of anti-aquaretics.


Subject(s)
Adaptor Proteins, Signal Transducing , Aquaporin 2 , Body Water , A Kinase Anchor Proteins/genetics , A Kinase Anchor Proteins/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Animals , Aquaporin 2/genetics , Aquaporin 2/metabolism , Body Water/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Homeostasis , Mice , Phosphorylation
2.
J Anesth ; 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38940927

ABSTRACT

PURPOSE: This study aimed to determine whether the administration of a modified thoracoabdominal nerves block through perichondrial approach (M-TAPA) could result in the blockade of the lateral cutaneous branches. This study focused on a newly discovered anatomical space/plane adjacent to the M-TAPA plane, which we termed "space between the endothoracic fascia, diaphragm, and costodiaphragmatic recess: SEDIC." METHODS: Thirteen sides of nine formalin-embalmed cadavers were macroscopically dissected to investigate the anatomical spaces related to the effects of M-TAPA. Furthermore, ten adult volunteers were administered 20 mL of 0.2% ropivacaine into the abdominal plane (corresponding to the M-TAPA plane) and the SEDIC, and a pinprick test was performed 1 h after the injection. RESULTS: Cadaver macrodissection revealed the presence of the SEDIC adjacent to the M-TAPA plane. The SEDIC was completely spatially isolated from the M-TAPA plane by the presence of costal cartilage and/or tendinous structures. In the volunteer study, the administration of local anesthetics into the SEDIC effectively blocked the lateral cutaneous branches of T8-T12, in addition to the anterior branches. CONCLUSION: Our study revealed the presence of the SEDIC adjacent to the M-TAPA plane. Administration of local anesthetics into the SEDIC, named re-modified TAPA, may have the potential to enhance the analgesic effect in the abdominal region.

3.
Surg Radiol Anat ; 46(5): 649-657, 2024 May.
Article in English | MEDLINE | ID: mdl-38573505

ABSTRACT

PURPOSE: This study aimed to clarify the structural arrangement of the orbicularis oris (OOr), the buccinator, and the other perioral muscles around the modiolus. METHODS: The perioral muscles in seventeen cadavers fixed with formalin were dissected in situ and/or in isolated muscle specimens, and their layers were reconstructed schematically upon pantomographic view of the skeleton to evaluate their actions. RESULTS: The buccinator was composed of three parts including upper and lower oblique parts in its superficial layer and a middle transverse part in its deep layer. The superior and inferior OOr were composed of an inner marginal part (IM) and an outer labial part (OL) in each. The perioral muscles as a whole were arranged in three layers. The first layer consisted of the depressor anguli oris and the OL of superior OOr connected at the modiolus in a vertical direction. The second layer consisted of the upper and inner oblique part of buccinator and a part of the OL of inferior OOr connected at the modiolus in a horizontal direction. The third layer contained the middle transverse part of buccinator continuous with the IM of both OOr and a part of the OL of inferior OOr without connection to the modiolus. CONCLUSIONS: The different arrangement of the three layers of perioral muscles around the modiolus could serve as a good basis to predict the actions of the individual perioral muscles on the movement of lips in open/close of the oral fissure and widening/narrowing of the lip width.


Subject(s)
Cadaver , Facial Muscles , Humans , Facial Muscles/anatomy & histology , Facial Muscles/diagnostic imaging , Male , Female , Aged , Aged, 80 and over , Middle Aged , Dissection , Lip/anatomy & histology , Lip/diagnostic imaging
4.
J Anat ; 243(2): 284-296, 2023 08.
Article in English | MEDLINE | ID: mdl-36914559

ABSTRACT

The structural and functional differences of individual hamstrings have not been sufficiently evaluated. This study aimed to clarify the morphological architecture of the hamstrings including the superficial tendons in detail using isolated muscle specimens, together with quantification of structural parameters of the muscle. Sixteen lower limbs of human cadavers were used in this study. The semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BFlh), and biceps femoris short head (BFsh) were dissected from cadavers to prepare isolated muscle specimens. Structural parameters, including muscle volume, muscle length, fiber length, sarcomere length, pennation angle, and physiological cross-sectional area (PCSA) were measured. In addition, the proximal and distal attachment areas of the muscle fibers were measured, and the proximal/distal area ratio was calculated. The SM, ST, and BFlh were spindle-shaped with the superficial origin and insertion tendons on the muscle surface, and the BFsh was quadrate with direct attachment to the skeleton and BFlh tendon. The muscle architecture was pennate in the four muscles. The four hamstrings possessed either of two types of structural parameters, one with shorter fiber length and larger PCSA, as in the SM and BFlh, and the other with longer fiber length and smaller PCSA, as in the ST and BFsh. Sarcomere length was unique in each of the four hamstrings, and thus the fiber length was suitably normalized using the average sarcomere length for each, instead of uniform length of 2.7 µm. The proximal/distal area ratio was even in the SM, large in the ST, and small in the BFsh and BFlh. This study clarified that the superficial origin and insertion tendons are critical determinants of the unique internal structure and structural parameters representing the functional properties of the hamstring muscles.


Subject(s)
Hamstring Muscles , Humans , Tendons/anatomy & histology , Muscle Fibers, Skeletal , Lower Extremity , Cadaver , Muscle, Skeletal/anatomy & histology
5.
Can J Anaesth ; 69(10): 1203-1210, 2022 10.
Article in English | MEDLINE | ID: mdl-35999334

ABSTRACT

PURPOSE: No reports have described techniques to efficiently anesthetize the lateral cutaneous branches of the entire abdomen. The aim of this study was to investigate an effective procedure for blocking the lateral cutaneous branches in the abdominal region. We sought to describe the sensory distribution of the previously described thoracoabdominal nerve block through perichondrial approach (TAPA) and the novel costal and lateral external oblique muscle plane (EXOP) blocks in healthy volunteers. METHODS: This was a proof-of-concept pilot study that comprised ten volunteers with an American Society of Anesthesiologists Physical Status I. The participants underwent modified TAPA (M-TAPA), injection 2 of TAPA (injection into the anterior aspect of the 10th costal cartilage: I2-TAPA), costal EXOP, and lateral EXOP blocks with injection of 20 mL of ropivacaine 0.2% for each block. A pinprick test was performed one hour after injection and repeated at 30-min intervals until the effect of the nerve block disappeared. RESULTS: The M-TAPA injection anesthetized the anterior branches from T6/7 to T11/12, whereas the I2-TAPA injection had no effect. Costal and lateral EXOP injections anesthetized the lateral cutaneous branches of T7-10 and T11-12, respectively. CONCLUSION: The results of this pilot study in ten healthy volunteers indicate that novel EXOP blocks involving local anesthetic injection superficial to the external oblique muscle efficiently anesthetize the lateral cutaneous branches of the thoracoabdominal nerves. Our study shows that it may be anatomically plausible for the combined use of these blocks to anesthetize the entire abdominal wall.


RéSUMé: OBJECTIF: Aucune présentation de cas n'a décrit de techniques permettant l'anesthésie efficace des branches cutanées latérales de tout l'abdomen. L'objectif de cette étude était d'évaluer une procédure efficace pour bloquer les branches cutanées latérales de la région abdominale. Nous avons cherché à décrire la distribution sensorielle du bloc nerveux thoraco-abdominal par approche périchondrale (TAPA), décrit précédemment, et des nouveaux blocs du plan musculaire oblique externe (EXOP) costal et latéral réalisés chez des volontaires sains. MéTHODE: Il s'agissait d'une étude pilote de preuve de concept qui comprenait dix volontaires avec un statut physique I selon l'American Society of Anesthesiologists. Les participants ont bénéficié d'un bloc TAPA modifié (M-TAPA), de l'injection 2 d'un bloc TAPA (injection dans l'aspect antérieur du 10e cartilage costal : I2-TAPA), d'un bloc EXOP costal et d'un bloc EXOP latéral avec injection de 20 mL de ropivacaïne 0,2 % pour chaque bloc. Un test cutané par piqûre d'épingle a été réalisé une heure après l'injection et répété à des intervalles de 30 minutes jusqu'à ce que l'effet du bloc nerveux disparaisse. RéSULTATS: L'injection de M-TAPA a anesthésié les branches antérieures de T6/7 à T11/12, tandis que l'injection d'I2-TAPA n'a eu aucun effet. Les injections costales et latérales d'EXOP ont anesthésié les branches cutanées latérales de T7­10 et T11­12, respectivement. CONCLUSION: Les résultats de cette étude pilote chez dix volontaires sains indiquent que les nouveaux blocs EXOP avec une injection superficielle d'anesthésique local au muscle oblique externe anesthésient efficacement les branches cutanées latérales des nerfs thoraco-abdominaux. Notre étude montre qu'il peut être anatomiquement plausible de combiner ces blocs pour anesthésier toute la paroi abdominale.


Subject(s)
Abdominal Wall , Anesthetics, Local , Abdominal Muscles/innervation , Abdominal Oblique Muscles , Abdominal Wall/innervation , Healthy Volunteers , Humans , Pilot Projects , Ropivacaine , Ultrasonography, Interventional/methods
6.
Eur J Orthop Surg Traumatol ; 32(2): 341-345, 2022 Feb.
Article in English | MEDLINE | ID: mdl-33885982

ABSTRACT

PURPOSE: Although pubic ramus fractures are common in the elderly, resultant hemodynamic instability is a rare complication. The corona mortis, a vascular anastomosis between the obturator vessels and the external iliac vessels in the retropubic space, is occasionally damaged by fractures of the pubic ramus, causing significant hemorrhage. The purpose of this study was to evaluate the incidence and anatomical position of the corona mortis on the anteroposterior and inlet views. METHODS: Sixty-one cadavers (122 hemipelvizes) were dissected and the incidence of the corona mortis was evaluated. Photographs were then taken simulating anteroposterior and inlet radiographs, and labeled as the anteroposterior and inlet views. The distance from the pubic symphysis to the corona mortis was measured on each of the two views. RESULTS: The corona mortis was present in 76.1% of hemipelvizes. The corona mortis traverses along the periosteum of the dorsal surface of the pubis. The incidence of arterial corona mortis was 28.3% and that of venous corona mortis was 76.1%. The distance from the superior margin of the symphysis pubis to the corona mortis measured 47.7 ± 9.9 (45.9-49.6) mm on the anteroposterior view, and 59.4 ± 9.2 (57.3-61.5) mm on the inlet view. CONCLUSIONS: In order to predict possible hemodynamic instability of the corona mortis following pubic ramus fractures, it is of clinical significance to precisely establish the anatomical position of the corona mortis on the anteroposterior and inlet views.


Subject(s)
Fractures, Bone , Pubic Symphysis , Aged , Bays , Humans , Iliac Artery/diagnostic imaging , Pelvis , Pubic Symphysis/diagnostic imaging
7.
Kidney Int ; 99(2): 382-395, 2021 02.
Article in English | MEDLINE | ID: mdl-33144214

ABSTRACT

Podocytes are highly specialized cells within the glomerulus that are essential for ultrafiltration. The slit diaphragm between the foot processes of podocytes functions as a final filtration barrier to prevent serum protein leakage into urine. The slit-diaphragm consists mainly of Nephrin and Neph1, and localization of these backbone proteins is essential to maintaining the integrity of the glomerular filtration barrier. However, the mechanisms that regulate the localization of these backbone proteins have remained elusive. Here, we focused on the role of membrane-associated guanylate kinase inverted 2 (MAGI-2) in order to investigate mechanisms that orchestrate localization of slit-diaphragm backbone proteins. MAGI-2 downregulation coincided with a reduced expression of slit-diaphragm backbone proteins in human kidneys glomerular disease such as focal segmental glomerulosclerosis or IgA nephropathy. Podocyte-specific deficiency of MAGI-2 in mice abrogated localization of Nephrin and Neph1 independently of other scaffold proteins. Although a deficiency of zonula occuldens-1 downregulated the endogenous Neph1 expression, MAGI-2 recovered Neph1 expression at the cellular edge in cultured podocytes. Additionally, overexpression of MAGI-2 preserved Nephrin localization to intercellular junctions. Co-immunoprecipitation and pull-down assays also revealed the importance of the PDZ domains of MAGI-2 for the interaction between MAGI-2 and slit diaphragm backbone proteins in podocytes. Thus, localization and stabilization of Nephrin and Neph1 in intercellular junctions is regulated mainly via the PDZ domains of MAGI-2 together with other slit-diaphragm scaffold proteins. Hence, these findings may elucidate a mechanism by which the backbone proteins are maintained.


Subject(s)
Glomerulosclerosis, Focal Segmental , Podocytes , Animals , Guanylate Kinases , Intercellular Junctions , Kidney Glomerulus , Mice
8.
Clin Anat ; 34(7): 991-1001, 2021 Oct.
Article in English | MEDLINE | ID: mdl-32783229

ABSTRACT

INTRODUCTION: Strains of the soleus are widely found both in amateur and professional athletes. For their accurate regional diagnoses, understanding the anatomy of the spatial relationship between muscular fibers and tendinous structures is important because their interfaces are susceptible sites to muscle strains. Therefore, this study evaluated the precise architecture of the soleus. MATERIALS AND METHODS: We evaluated the precise anatomical architecture of the soleus in 87 formaldehyde-fixed soleus muscles. To calculate mean relative physiological cross-sectional area of each muscular fiber compartment, we measured the fiber length, volume, and pennation angle in isolated compartments. RESULTS: The posterior soleus surface was covered by a broad aponeurotic posterior insertion tendon (PIT), which continued inferiorly to the insertion tendon. The anterior surface had three aponeurotic origin tendons, lateral origin tendon (LOT), medial origin tendon (MOT), and tendinous arch, which were arranged along the soleus margins. The anterior bipennate muscle portion (ABP), surrounded by the three origin structures, terminated as the sagittal insertion tendon (SIT), which continued inferiorly to PIT. The posterior main muscle portion behind LOT and MOT was separated into lateral and medial portions by the SIT. The soleus thus possessed a broad musculotendinous junction. Furthermore, ABP exhibited wide structural diversity in shape and size: in extreme cases, it was duplicated or absent. CONCLUSION: Systematic anatomical descriptions of the soleus will be useful for accurate regional diagnosis of its strains with magnetic resonance imaging and ultrasonography.


Subject(s)
Leg/anatomy & histology , Muscle, Skeletal/anatomy & histology , Tendons/anatomy & histology , Aged , Aged, 80 and over , Cadaver , Female , Humans , Male
9.
Cell Tissue Res ; 382(3): 609-625, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33191456

ABSTRACT

The excretory system produces urine by ultrafiltration via a filtration epithelium. Podocytes are widely found as filtration epithelial cells in eucoelomates. In some animal taxa, including insects and crustaceans, nephrocytes serve to separate toxic substances from the body fluid, in addition to podocytes. Drosophila nephrocytes have been recently utilized as a model system to study podocyte function and disease. However, functionality and cellular architecture are strikingly different between Drosophila nephrocytes and eucoelomate podocytes, and the phylogenetic relationship between these cells remains enigmatic. In this study, using focused-ion beam-scanning electron microscopy (FIB-SEM) tomography, we revealed three-dimensional architecture of decapod nephrocytes with unprecedented accuracy-they filled an enormous gap, which can be called "missing link," in the evolutionary diversity of podocytes and nephrocytes. Thus, we concluded that nephrocytes are part of the spectrum of filtration epithelial diversity in animal phylogeny.


Subject(s)
Drosophila Proteins/genetics , Podocytes/metabolism , Animals , Drosophila melanogaster , Phylogeny
10.
Cell Tissue Res ; 379(2): 245-254, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31758252

ABSTRACT

Podocytes are specialized epithelial cells used for glomerular filtration in the kidney. They can be divided into the cell body, primary process and foot process. Here, we describe two useful methods for the three-dimensional(3D) visualization of these subcellular compartments in rodent podocytes. The first method, field-emission scanning electron microscopy (FE-SEM) with conductive staining, is used to visualize the luminal surface of numerous podocytes simultaneously. The second method, focused-ion beam SEM (FIB-SEM) tomography, allows the user to obtain serial images from different depths of field, or Z-stacks, of the glomerulus. This allows for the 3D reconstruction of podocyte ultrastructure, which can be viewed from all angles, from a single image set. This is not possible with conventional FE-SEM. The different advantages and disadvantages of FE-SEM and FIB-SEM tomography compensate for the weaknesses of the other. The combination renders a powerful approach for the 3D analysis of podocyte ultrastructure. As a result, we were able to identify a new subcellular compartment of podocytes, "ridge-like prominences" (RLPs).


Subject(s)
Imaging, Three-Dimensional , Microscopy, Electron, Scanning , Podocytes/ultrastructure , Tomography , Animals , Male , Rats , Subcellular Fractions/ultrastructure
11.
J Am Soc Nephrol ; 30(1): 96-108, 2019 01.
Article in English | MEDLINE | ID: mdl-30514724

ABSTRACT

BACKGROUND: Foot process effacement is one of the pathologic indicators of podocyte injury. However, the morphologic changes associated with it remain unclear. METHODS: To clarify the developmental process, we analyzed puromycin nephrotic podocytes reconstructed from serial focused-ion beam/scanning electron microscopy (FIB/SEM) images. RESULTS: Intact podocytes consisted of four subcellular compartments: cell body, primary process, ridge-like prominence (RLP), and foot process. The RLP, a longitudinal protrusion from the basal surface of the cell body and primary process, served as an adhesive apparatus for the cell body and primary process to attach to the glomerular basement membrane. Foot processes protruded from both sides of the RLP. In puromycin nephrotic podocytes, foot process effacement occurred in two ways: by type-1 retraction, where the foot processes retracted while maintaining their rounded tips; or type-2 retraction, where they narrowed across their entire lengths, tapering toward the tips. Puromycin nephrotic podocytes also exhibited several alterations associated with foot process effacement, such as deformation of the cell body, retraction of RLPs, and cytoplasmic fragmentation. Finally, podocytes were reorganized into a broad, flattened shape. CONCLUSIONS: The three-dimensional reconstruction of podocytes by serial FIB/SEM images revealed the morphologic changes involved in foot process effacement in greater detail than previously described.


Subject(s)
Glomerular Basement Membrane/pathology , Imaging, Three-Dimensional , Nephrosis/pathology , Podocytes/pathology , Puromycin Aminonucleoside/pharmacology , Tomography, X-Ray Computed/methods , Animals , Cells, Cultured , Disease Models, Animal , Injections, Intraperitoneal , Male , Microscopy, Electron, Scanning/methods , Nephrosis/chemically induced , Podocytes/cytology , Podocytes/drug effects , Random Allocation , Rats , Rats, Wistar , Reference Values
12.
Arthroscopy ; 36(11): 2814-2819, 2020 11.
Article in English | MEDLINE | ID: mdl-32622803

ABSTRACT

PURPOSE: To measure the height of the posteroinferior glenohumeral ligament (PIGHL) attachment to the labrum and the depth of the posteroinferior labrum to the glenoid, macroscopically, and to investigate the morphology of the attachment of the posteroinferior labrum to the glenoid, histologically. METHODS: Fifty cadaveric shoulders without exposed subchondral bone on the glenoid and detached posterior labrum were used. We examined the frequency of the heights of the PIGHL attachments to the labrum and the length of the labral attachment on the glenoid rim at the 7, 8, 9, and 10 o'clock positions, macroscopically. According to morphology of the histological labral attachments, it was divided into 3 groups. Labra attached on the articular surface and the glenoid neck were defined as the SN type, while labra attached only to the glenoid neck constituted labra attached to the bone and side of the articular cartilage (Nc type) and labra attached only to bone (Nb type). RESULTS: The PIGHL attached from 7 o'clock to 9 o'clock in 48 shoulders (96%). The mean labral attachment at the 7 o'clock position was 6.3 ± 1.0 mm (range, 4.6-9.4 mm), which was significantly longer than at the other positions (P < .05). Histologically, the frequency of SN type attachment was 49 (98%) shoulders at the 7 o'clock position. CONCLUSIONS: The PIGHL attached between 7 and 9 o'clock in 96% of the shoulders. In 98% of the shoulders, the labrum did not attach to the articular surface, but attached to both the articular cartilage and the bone of the glenoid neck at 7 o'clock. CLINICAL RELEVANCE: The posteroinferior labrum should be repaired widely at the 7 o'clock position and not on the articular surface because the labrum attached anatomically to the glenoid neck.


Subject(s)
Scapula/anatomy & histology , Shoulder Joint/surgery , Aged , Aged, 80 and over , Cadaver , Cartilage, Articular/anatomy & histology , Female , Humans , Ligaments, Articular/anatomy & histology , Male , Middle Aged
13.
Clin Anat ; 33(4): 479-487, 2020 May.
Article in English | MEDLINE | ID: mdl-31008535

ABSTRACT

The localization of nutrient foramina and direction of nutrient canals have been studied. However, information about the origin and extraosseous course of nutrient arteries is lacking in some types of long tubular and irregular bones. Thus, we aimed to reexamine the origin and course of the femoral nutrient artery (FNA) through cadaveric dissection to clarify its anatomic characteristics. Sixty thighs were collected from 57 cadavers. To fix the cadavers and visualize the small arterial branches, 10% formalin was injected from the femoral artery, followed by an injection of acrylic ink. The arterial tree in the posterior part of the thigh was recorded by line drawings. The femur received single or double FNAs via the femoral nutrient foramina, which were on and along the linea aspera. In cases with single FNA (41 of the 60 thighs), it typically arose from the four parts of the profunda femoris system: profunda femoris artery between the origins of the third and fourth perforating arteries; second perforating artery; third perforating artery; and terminal branch. In cases with double FNAs (remaining 19 thighs), the superior FNA typically arose from the second perforating artery, and the inferior FNA arose from the terminal branch of the profunda femoris artery and popliteal system. FNAs are described as branches of the perforating arteries in Terminologia Anatomica and anatomy textbooks. However, we found that FNAs also frequently arose from the profunda femoris artery and popliteal system, in addition to the perforating arteries. Clin. Anat. 33:479-487, 2020. © 2019 Wiley Periodicals, Inc.


Subject(s)
Femoral Artery/anatomy & histology , Femur/blood supply , Cadaver , Dissection , Female , Femur/surgery , Fractures, Bone/surgery , Humans , Male
14.
J Cell Sci ; 130(1): 132-142, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27358478

ABSTRACT

Podocytes present a unique 3D architecture specialized for glomerular filtration. However, several 3D morphological aspects on podocyte development remain partially understood because they are difficult to reveal using conventional scanning electron microscopy (SEM). Here, we adopted serial block-face SEM imaging, a powerful tool for analyzing the 3D cellular ultrastructure, to precisely reveal the morphological process of podocyte development, such as the formation of foot processes. Development of foot processes gives rise to three morphological states: the primitive, immature and mature foot processes. Immature podocytes were columnar in shape and connected to each other by the junctional complex, which migrated toward the basal side of the cell. When the junctional complex was close to the basement membrane, immature podocytes started to interdigitate with primitive foot processes under the level of junctional complex. As primitive foot processes lengthened, the junctional complex moved between primitive foot processes to form immature foot processes. Finally, the junctional complex was gradually replaced by the slit diaphragm, resulting in the maturation of immature foot processes into mature foot processes. In conclusion, the developmental process of podocytes is now clearly visualized by block-face SEM imaging.


Subject(s)
Cell Shape , Microscopy, Electron, Scanning/methods , Podocytes/cytology , Podocytes/ultrastructure , Animals , Kidney Glomerulus/blood supply , Kidney Glomerulus/cytology , Kidney Glomerulus/ultrastructure , Male , Rats, Wistar
15.
Cell Tissue Res ; 378(2): 289-300, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31089884

ABSTRACT

Nephrocytes are similar in structure to podocytes and play a role in the isolation of toxic substances from hemolymph in insects. Drosophila melanogaster nephrocytes have recently been used to study podocyte function and disease. However, the three-dimensional ultrastructure of nephrocytes is not clearly understood because their surrounding basement membrane makes it difficult to observe using conventional scanning electron microscopy. We reconstructed the three-dimensional ultrastructure of Drosophila pericardial nephrocytes using serial focused-ion beam/scanning electron microscopy (FIB/SEM) images. The basal surfaces were occupied by foot processes and slit-like spaces between them. The slit-like spaces corresponded to the podocyte filtration slits and were formed by longitudinal infolding/invagination of the basal plasma membrane. The basal surface between the slit-like spaces became the foot processes, which ran almost linearly, and had a "washboard-like" appearance. Both ends of the foot processes were usually anastomosed to neighboring foot processes and thus free ends were rarely observed. We demonstrated that FIB/SEM is a powerful tool to better understand the three-dimensional architecture of nephrocytes.


Subject(s)
Drosophila melanogaster/cytology , Imaging, Three-Dimensional/methods , Podocytes/ultrastructure , Animals
17.
Clin Anat ; 31(3): 404-408, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29044664

ABSTRACT

There is currently no method to quantify the quality of the harvested graft before anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to explore a method for measuring stiffness of the normal tendon of the semitendinosus muscle using shear wave elastography (SWE). Our investigation comprised two steps. First, we determined orientation of the semitendinosus tendon fibers in 20 lower legs of embalmed cadavers. Second, we investigated the feasibility of quantifying stiffness of the normal semitendinosus tendon by SWE in 24 subjects (48 legs: 24 male and 24 female subjects) in vivo. Measured values were compared between male and female subjects. The point at the intersection of the semitendinosus tendon with the axial section through the center of the patella mostly was the middle of the semitendinosus tendon in the cadavers. The SWE modulus in all of the subjects could be measured on this point in vivo. The SWE modulus of males and females were 474.0 ± 71.9 kPa and 396.9 ± 104.5 kPa, respectively. The SWE modulus of males was significantly larger than that of females (P < 0.01). This study demonstrates that stiffness of the tendon of the semitendinosus muscle can be measured by SWE. It also shows that tendon of the semitendinosus muscle in males is stiffer than in females. Clin. Anat. 31:404-408, 2018. © 2017 Wiley Periodicals, Inc.


Subject(s)
Anterior Cruciate Ligament Reconstruction , Elasticity Imaging Techniques , Hamstring Tendons/diagnostic imaging , Transplants/diagnostic imaging , Aged , Aged, 80 and over , Feasibility Studies , Female , Humans , Male
18.
J Am Soc Nephrol ; 27(9): 2685-700, 2016 09.
Article in English | MEDLINE | ID: mdl-26823550

ABSTRACT

Studies have revealed many analogies between podocytes and neurons, and these analogies may be key to elucidating the pathogenesis of podocyte injury. Cathepsin D (CD) is a representative aspartic proteinase in lysosomes. Central nervous system neurons in CD-deficient mice exhibit a form of lysosomal storage disease with a phenotype resembling neuronal ceroid lipofuscinoses. In the kidney, the role of CD in podocytes has not been fully explored. Herein, we generated podocyte-specific CD-knockout mice that developed proteinuria at 5 months of age and ESRD by 20-22 months of age. Immunohistochemical analysis of these mice showed apoptotic podocyte death followed by proteinuria and glomerulosclerosis with aging. Using electron microscopy, we identified, in podocytes, granular osmiophilic deposits (GRODs), autophagosome/autolysosome-like bodies, and fingerprint profiles, typical hallmarks of CD-deficient neurons. CD deficiency in podocytes also led to the cessation of autolysosomal degradation and accumulation of proteins indicative of autophagy impairment and the mitochondrial ATP synthase subunit c accumulation in the GRODs, again similar to changes reported in CD-deficient neurons. Furthermore, both podocin and nephrin, two essential components of the slit diaphragm, translocated to Rab7- and lysosome-associated membrane glycoprotein 1-positive amphisomes/autolysosomes that accumulated in podocyte cell bodies in podocyte-specific CD-knockout mice. We hypothesize that defective lysosomal activity resulting in foot process effacement caused this accumulation of podocin and nephrin. Overall, our results suggest that loss of CD in podocytes causes autophagy impairment, triggering the accumulation of toxic subunit c-positive lipofuscins as well as slit diaphragm proteins followed by apoptotic cell death.


Subject(s)
Cathepsin D/physiology , Podocytes , Proteinuria/etiology , Renal Insufficiency, Chronic/etiology , Animals , Mice , Mice, Knockout , Podocytes/pathology
19.
Clin Anat ; 30(1): 98-105, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27598432

ABSTRACT

The quadriceps femoris (QF), a major extensor of the knee joint, plays an important role in human movement. However, descriptions of the three vastus muscles of the QF in anatomy textbooks remain confusing. We analyzed 33 QFs by a novel approach, using isolated muscle specimens to clarify the structures of the vastus lateralis (VL), vastus medialis (VM), and vastus intermedius (VI) origins. The origins of the VL and VM were quite constant in shape and location, but the VI was much more structurally diverse. In typical cases (23 of 33), the origin of the VI attached muscularly to the anterior and lateral surface of the femoral shaft. It adjoined the origin of the VL at the lateral lip (LL) of the linea aspera to form a common origin. In some cases (10 of 33), the muscle belly and origin of the VI were much smaller than those in the typical cases; the origin of the VI attached only to the anterior surface of the femur and did not contact the LL. In addition, the muscle belly of the VI was narrow and almost corresponded to the width of the femoral shaft. The isolated muscle specimen is a useful tool for analyzing individual muscle structures, which can be difficult to observe by routine dissection. Using this method, it became clear that the VI is more structurally diverse in its origin than the VL and VM. Clin. Anat. 30:98-105, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Quadriceps Muscle/anatomy & histology , Aged , Aged, 80 and over , Anatomic Variation , Female , Humans , Male
20.
Clin Anat ; 30(7): 978-987, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28795436

ABSTRACT

Anatomic characterization of the humeral nutrient artery varies among the several textbooks on human anatomy. To clarify the anatomic characteristics of the humeral nutrient artery, we reexamined its origin and course by cadaveric dissection. In typical cases, one prominent nutrient foramen was situated on the anteromedial surface of the humeral shaft, and the nutrient canal distally penetrated the cortical bone layer. The humeral nutrient artery originated from the brachial artery below the level of the nutrient foramen as a short ascending branch. On reaching near the nutrient foramen, the humeral nutrient artery formed a hairpin loop on the periosteum to enter into the nutrient foramen. In some cases, an accessory nutrient foramen was also found near the groove for the radial nerve on the posterior surface of the humerus. This accessory nutrient foramen received an accessory humeral nutrient artery that originated from the radial collateral artery. The present findings corresponded well with the descriptions in the anatomy textbooks published in English-speaking countries. However, textbooks published in German-speaking countries describe only one type of humeral nutrient artery, the branch of the profunda brachii artery. Terminologia Anatomica, the international standard in human anatomic terminology, most likely adopted the description in the German anatomy textbooks, and thus, it is necessary to correct the position of the humeral nutrient artery in the hierarchy of Terminologia Anatomica for accurate morphological description. Clin. Anat. 30:978-987, 2017. © 2017 Wiley Periodicals, Inc.


Subject(s)
Arteries/anatomy & histology , Humerus/blood supply , Adult , Brachial Artery/anatomy & histology , Cadaver , Dissection , Female , Fracture Healing , Humans , Humeral Fractures/physiopathology , Humerus/surgery , Male , Periosteum/anatomy & histology
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