1.Fetal development and growth of the human neck axial musculature
Sayako SUZUKI ; Eri MIYAMOTO ; Yuki YOSHIHASHI ; Masahito YAMAMOTO ; Gen MURAKAMI ; Shin-ichi ABE ; Jose Francisco RODRÍGUEZ-VÁZQUEZ
Anatomy & Cell Biology 2026;59(1):68-81
Neck epaxial muscles, which are differentiated for suspending the head, occupy a large space posterior to the cervical lordosis. Limited information exists regarding developmental process that determines the muscle fiber direction and bony attachment of neck epaxial muscles. We examined histological sections of 28 human fetuses aged approximately 7–18 weeks (crown-rump length, 20–150 mm). In place of the underdeveloped lordosis, the transverse process of cervical vertebrae was shifted anteriorly at the cervicothoracic junction. The semispinalis and longissimus were distinguished by the direction of muscle fibers connecting between the surface aponeurosis and transverse process. The semispinalis capitis and splenius capitis had a bulky anterior margin without bony attachments. The obliquus capitis inferior continued to both the rectus capitis posterior major and the semispinalis cervicis, but the obliquus capitis superior was consistently independent. Muscle attachments to the scapula were quite different from the final morphology: 1) the levator and rhomboidei usually extended inferiorly along the developing scapula beyond the inferior angle and 2) the splenius capitis or semispinalis cervicis rarely issued an aberrant bundle attaching to the scapula. The scaleni, rhomboidei, levator scapulae, iliocostalis and longissimus were arranged in parallel from the anteromedial to the posterolateral planes and together formed a thick oblique muscle bundle originating from the cervical transverse process and running toward the upper thoracic vertebra and ribcage. The transient oblique muscle bundle seen in early fetuses seemed to provide the so-called intermediate axial muscle between the epaxial-hypaxial muscles: a concept postulated in recent molecular neurology and embryology.
2.Safety and efficacy of trans-afferent loop endoscopic ultrasound-guided pancreaticojejunostomy for post pancreaticoduodenectomy anastomotic stricture using the forward-viewing echoendoscope: a retrospective study from Japan
Ahmed SADEK ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO ; Kenneth TACHI
Clinical Endoscopy 2025;58(2):311-319
Background/Aims:
Endoscopic ultrasound (EUS)-guided pancreatic duct drainage is a well-established procedure for managing pancreaticojejunostomy anastomotic strictures (PJAS) post-Whipple surgery. In this study, we examined the effectiveness and safety of EUS-guided pancreaticojejunostomy (EUS-PJS).
Methods:
This retrospective, single-arm study was performed at Aichi Cancer Center Hospital on 10 patients who underwent EUS-guided pancreaticojejunostomy through the afferent jejunal loop using a forward-viewing echoendoscope when endoscopic retrograde pancreatography failed. Our primary endpoint was technical success rate, defined as successful stent insertion. The secondary endpoints were early and late adverse events.
Results:
A total of 10 patients underwent EUS-PJS between February 2019 and October 2023. The technical success rate was 100%. The median procedure time was 23.5 minutes. No remarkable early or late adverse events related to the procedure, except for fever, occurred in two patients. The median follow-up duration was 9.5 months, and the median number of stent exchanges was two. A stent-free state was achieved in three patients.
Conclusions
EUS-PJS for PJAS management after pancreaticoduodenectomy appears to be an effective and safe procedure with the potential advantages of fewer reinterventions and the creation of a permanent drainage fistula.
3.Efficacy and safety of endoscopic ultrasound-guided hepaticogastrostomy for biliary drainage in hypervascular hepatocellular carcinoma: a retrospective study from Japan
Kenneth TACHI ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Ahmed Mohammed SADEK ; Hossam El-Din Shaaban Mahmoud IBRAHIM ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO
Clinical Endoscopy 2025;58(3):448-456
Background/Aims:
Biliary obstruction drainage in patients with hepatocellular carcinoma (HCC) is associated with symptom palliation, improved access to chemotherapy, and improved survival. Stent placement and exchange via endoscopic retrograde cholangiopancreatography biliary drainage risk traversing the HCC, a hypervascular tumor and causing bleeding. Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) potentially prevents procedure-related bleeding. Therefore, we evaluated the efficacy and safety of EUS-HGS as an alternative treatment for biliary obstruction in patients with HCC.
Methods:
This was a retrospective study of all EUS-HGS procedures performed in patients with HCC at the Aichi Cancer Center Hospital, Japan, from February 2017 to August 2023.
Results:
A total of 14 EUS-HGS procedures (42.9% primary) were attempted in 10 HCC patients (mean age 71.5 years, 80.0% male). Clinical and technical success rates were 92.9% and 90.9%, respectively. The observed procedure details in the 13 successful procedures included B3 puncture (53.8%), 22-G needle (53.8%), fully covered self-expandable metal stent (100%), and mean procedure time (32.7 minutes). There was no bleeding. Mild complications occurred in 27.3%. All patients resumed oral intake within 24 hours.
Conclusions
EUS-HGS is a technically feasible and clinically effective initial or salvage drainage option for the treatment of biliary obstruction in patients with HCC.
4.Safety and efficacy of trans-afferent loop endoscopic ultrasound-guided pancreaticojejunostomy for post pancreaticoduodenectomy anastomotic stricture using the forward-viewing echoendoscope: a retrospective study from Japan
Ahmed SADEK ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO ; Kenneth TACHI
Clinical Endoscopy 2025;58(2):311-319
Background/Aims:
Endoscopic ultrasound (EUS)-guided pancreatic duct drainage is a well-established procedure for managing pancreaticojejunostomy anastomotic strictures (PJAS) post-Whipple surgery. In this study, we examined the effectiveness and safety of EUS-guided pancreaticojejunostomy (EUS-PJS).
Methods:
This retrospective, single-arm study was performed at Aichi Cancer Center Hospital on 10 patients who underwent EUS-guided pancreaticojejunostomy through the afferent jejunal loop using a forward-viewing echoendoscope when endoscopic retrograde pancreatography failed. Our primary endpoint was technical success rate, defined as successful stent insertion. The secondary endpoints were early and late adverse events.
Results:
A total of 10 patients underwent EUS-PJS between February 2019 and October 2023. The technical success rate was 100%. The median procedure time was 23.5 minutes. No remarkable early or late adverse events related to the procedure, except for fever, occurred in two patients. The median follow-up duration was 9.5 months, and the median number of stent exchanges was two. A stent-free state was achieved in three patients.
Conclusions
EUS-PJS for PJAS management after pancreaticoduodenectomy appears to be an effective and safe procedure with the potential advantages of fewer reinterventions and the creation of a permanent drainage fistula.
5.Efficacy and safety of endoscopic ultrasound-guided hepaticogastrostomy for biliary drainage in hypervascular hepatocellular carcinoma: a retrospective study from Japan
Kenneth TACHI ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Ahmed Mohammed SADEK ; Hossam El-Din Shaaban Mahmoud IBRAHIM ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO
Clinical Endoscopy 2025;58(3):448-456
Background/Aims:
Biliary obstruction drainage in patients with hepatocellular carcinoma (HCC) is associated with symptom palliation, improved access to chemotherapy, and improved survival. Stent placement and exchange via endoscopic retrograde cholangiopancreatography biliary drainage risk traversing the HCC, a hypervascular tumor and causing bleeding. Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) potentially prevents procedure-related bleeding. Therefore, we evaluated the efficacy and safety of EUS-HGS as an alternative treatment for biliary obstruction in patients with HCC.
Methods:
This was a retrospective study of all EUS-HGS procedures performed in patients with HCC at the Aichi Cancer Center Hospital, Japan, from February 2017 to August 2023.
Results:
A total of 14 EUS-HGS procedures (42.9% primary) were attempted in 10 HCC patients (mean age 71.5 years, 80.0% male). Clinical and technical success rates were 92.9% and 90.9%, respectively. The observed procedure details in the 13 successful procedures included B3 puncture (53.8%), 22-G needle (53.8%), fully covered self-expandable metal stent (100%), and mean procedure time (32.7 minutes). There was no bleeding. Mild complications occurred in 27.3%. All patients resumed oral intake within 24 hours.
Conclusions
EUS-HGS is a technically feasible and clinically effective initial or salvage drainage option for the treatment of biliary obstruction in patients with HCC.
6.Safety and efficacy of trans-afferent loop endoscopic ultrasound-guided pancreaticojejunostomy for post pancreaticoduodenectomy anastomotic stricture using the forward-viewing echoendoscope: a retrospective study from Japan
Ahmed SADEK ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO ; Kenneth TACHI
Clinical Endoscopy 2025;58(2):311-319
Background/Aims:
Endoscopic ultrasound (EUS)-guided pancreatic duct drainage is a well-established procedure for managing pancreaticojejunostomy anastomotic strictures (PJAS) post-Whipple surgery. In this study, we examined the effectiveness and safety of EUS-guided pancreaticojejunostomy (EUS-PJS).
Methods:
This retrospective, single-arm study was performed at Aichi Cancer Center Hospital on 10 patients who underwent EUS-guided pancreaticojejunostomy through the afferent jejunal loop using a forward-viewing echoendoscope when endoscopic retrograde pancreatography failed. Our primary endpoint was technical success rate, defined as successful stent insertion. The secondary endpoints were early and late adverse events.
Results:
A total of 10 patients underwent EUS-PJS between February 2019 and October 2023. The technical success rate was 100%. The median procedure time was 23.5 minutes. No remarkable early or late adverse events related to the procedure, except for fever, occurred in two patients. The median follow-up duration was 9.5 months, and the median number of stent exchanges was two. A stent-free state was achieved in three patients.
Conclusions
EUS-PJS for PJAS management after pancreaticoduodenectomy appears to be an effective and safe procedure with the potential advantages of fewer reinterventions and the creation of a permanent drainage fistula.
7.Efficacy and safety of endoscopic ultrasound-guided hepaticogastrostomy for biliary drainage in hypervascular hepatocellular carcinoma: a retrospective study from Japan
Kenneth TACHI ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Ahmed Mohammed SADEK ; Hossam El-Din Shaaban Mahmoud IBRAHIM ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO
Clinical Endoscopy 2025;58(3):448-456
Background/Aims:
Biliary obstruction drainage in patients with hepatocellular carcinoma (HCC) is associated with symptom palliation, improved access to chemotherapy, and improved survival. Stent placement and exchange via endoscopic retrograde cholangiopancreatography biliary drainage risk traversing the HCC, a hypervascular tumor and causing bleeding. Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) potentially prevents procedure-related bleeding. Therefore, we evaluated the efficacy and safety of EUS-HGS as an alternative treatment for biliary obstruction in patients with HCC.
Methods:
This was a retrospective study of all EUS-HGS procedures performed in patients with HCC at the Aichi Cancer Center Hospital, Japan, from February 2017 to August 2023.
Results:
A total of 14 EUS-HGS procedures (42.9% primary) were attempted in 10 HCC patients (mean age 71.5 years, 80.0% male). Clinical and technical success rates were 92.9% and 90.9%, respectively. The observed procedure details in the 13 successful procedures included B3 puncture (53.8%), 22-G needle (53.8%), fully covered self-expandable metal stent (100%), and mean procedure time (32.7 minutes). There was no bleeding. Mild complications occurred in 27.3%. All patients resumed oral intake within 24 hours.
Conclusions
EUS-HGS is a technically feasible and clinically effective initial or salvage drainage option for the treatment of biliary obstruction in patients with HCC.
8.Effects of speech duration and voice volume on the respiratory aerosol particle concentration.
Tomoki TAKANO ; Yiming XIANG ; Masayuki OGATA ; Yoshihide YAMAMOTO ; Satoshi HORI ; Shin-Ichi TANABE
Environmental Health and Preventive Medicine 2025;30():14-14
BACKGROUND:
SARS-CoV-2 (COVID-19) is transmitted via infectious respiratory particles. Infectious respiratory particles are released when an infected person breathes, coughs, or speaks. Several studies have measured respiratory particle concentrations through focusing on activities such as breathing, coughing, and short speech. However, few studies have investigated the effect of speech duration.
METHODS:
This study aimed to clarify the effects of speech duration and volume on the respiratory particle concentration. Study participants were requested to speak at three voice volumes across five speech durations, generating 15 speech patterns. Participants spoke inside a clean booth where particle concentrations and voice volumes were measured and analyzed during speech.
RESULTS:
Our findings suggest that as speech duration increased, the aerosol number concentration also increased. Through focusing on individual differences, we considered there might be super-emitters who emit more aerosol particles than the average human. Two participants were identified as statistical outliers (aerosol number concentration, n = 1; mass concentration, n = 1).
CONCLUSIONS
Considering speech duration may improve our understanding of respiratory particle concentration dynamics. Two participants were identified as potential super-emitters.
Humans
;
Male
;
Speech/physiology*
;
Adult
;
Female
;
COVID-19/transmission*
;
Respiratory Aerosols and Droplets
;
Voice
;
SARS-CoV-2
;
Time Factors
;
Young Adult
;
Aerosols/analysis*
9.Development and growth of the temporal fascia: a histological study using human fetuses
Kei KITAMURA ; Satoshi ISHIZUKA ; Ji Hyun KIM ; Hitoshi YAMAMOTO ; Gen MURAKAMI ; Jose Francisco RODRÍGUEZ-VÁZQUEZ ; Shin-ichi ABE
Anatomy & Cell Biology 2024;57(2):288-293
The temporal fascia is a double lamina sandwiching a thick fat layer above the zygomatic bony arch. To characterize each lamina, their developmental processes were examined in fetuses. We observed histological sections from 22 half-heads of 10 mid-term fetuses at 14–18 weeks (crown-rump length, 95–150 mm) and 12 near-term fetuses at 26–40 weeks (crown-rump length, 215–334 mm). The superficial lamina of the temporal fascia was not evident at mid-term. Instead, a loose subcutaneous tissue was attached to the thin, deep lamina of the temporal fascia covering the temporalis muscle. At near-term, the deep lamina became thick, while the superficial lamina appeared and exhibited several variations: i) a monolayered thick membrane (5 specimens); ii) a multi-layered membranous structure (6) and; iii) a cluster of independent thick fasciae each of which were separated by fatty tissues (1). In the second and third patterns, fatty tissue between the two laminae was likely to contain longitudinal fibrous bands in parallel with the deep lamina. Varying proportions of the multi-layered superficial lamina were not attached to the zygomatic arch, but extended below the bony arch. Whether or not lobulation or septation of fatty tissues was evident was not dependent on age. The deep lamina seemed to develop from the temporalis muscle depending on the muscle contraction. In contrast, the superficial lamina developed from subcutaneous collagenous bundles continuous to the cheek. Therein, a difference in development was clearly seen between two categories of the fasciae.
10.Safety and efficacy of endoscopic ultrasound-guided pancreatic duct drainage using a drill dilator: a retrospective study in Japan
Ahmed SADEK ; Kazuo HARA ; Nozomi OKUNO ; Shin HABA ; Takamichi KUWAHARA ; Toshitaka FUKUI ; Minako URATA ; Takashi KONDO ; Yoshitaro YAMAMOTO ; Kenneth TACHI
Clinical Endoscopy 2024;57(5):666-674
Background/Aims:
Dilation of the tract before stent deployment is a challenging step in endoscopic ultrasound-guided pancreatic duct drainage (EUS-PDD). In this study, we examined the effectiveness and safety of a novel spiral dilator, Tornus ES (Asahi Intec), for EUS-PDD.
Methods:
This was a retrospective, single-arm, observational study at Aichi Cancer Center Hospital. The punctured tract was dilated using a Tornus ES dilator in all EUS-PDD cases. Our primary endpoint was the technical success rate of initial tract dilation. Technical success was defined as successful fistula dilation using a Tornus ES followed by successful stent insertion. Secondary endpoints were procedure times and early adverse events.
Results:
A total of 12 patients were included between December 2021 and March 2023. EUS-PDD was performed in 11 patients for post-pancreaticoduodenectomy anastomotic strictures and one patient with pancreatitis with duodenal perforation. The technical success rates of stent insertion and fistula dilation using a Tornus ES dilator was 100%. The median procedure time was 24 minutes. No remarkable adverse events related to the procedure were observed, apart from fever, which occurred in 2 patients.
Conclusions
Tract dilation in EUS-PDD using a Tornus ES is effective and safe.

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