[Mechanisms of bone formation by primary cilia].

Primary cilia are immotile cilia assembled from the centriole-derived basal body, and they protrude on the cell surface in almost all cell types during the cell cycle G0 phase. Due to the diffusion barrier at the ciliary base, cilia harbor selective G protein-coupled receptors, growth factor receptors, and ion channels on their membrane. Thus, cilia act as sensory organelles, regulating the proliferation and differentiation of the cells and promoting the formation and maturation of various organs including bone, brain, and kidney. It has been unveiled that malformation and dysregulation of cilia cause organ dysplasia, so-called ciliopathy, thus research on primary cilia has become active during the past 20 years. Research on the roles of cilia in bone formation and its regulatory mechanisms have also progressed. It is widely recognized that cilia of preosteoblasts receive hedgehog and promote differentiation of the cells to osteoblasts, resulting in the formation of skulls and long bones. Recently, it has been shown that a membrane-associated protein 4.1G is important in ciliogenesis, hedgehog signaling, and osteoblast differentiation in neonatal bone formation. In this review, we would like to summarize the roles of primary cilia in bone formation and their regulatory mechanisms including the contribution of 4.1G.

[Accuracy Verification for Slice Sensitivity Profile Measurement Method by Averaging the Multiple Tilted Wires in Computed Tomography Image].

PURPOSE: Several studies present the unsuitability of the tilted-wire method for slice sensitivity profile (SSP) in helical scan. We compared the accuracy for SSP by the tilted-wire averaging method using multiple wire profiles and by the conventional micro-coin method. METHODS: A micro-coin phantom positioned at the center or the off-center was scanned using a 64-detector row CT scanner in different positions where an X-ray tube starts scanning. In the same way, tilted-wire averaging phantoms, approximately 70 mm in diameter, in the shape of a donut, 8 wires tilted from the circumference toward the center, were scanned. Images were reconstructed with a slice thickness of 0.5 mm. RESULTS: The relative errors of full width at half maximum (FWHM) by the tilted-wire averaging method were -0.015 mm to -0.004 mm (-1.98% to -0.56%) at the center compared to those by the micro-coin method, and it is almost the same value regardless of the number of wires. Relative errors were 0.001 mm to 0.029 mm (0.11% to 3.74%) at the upper 8 cm from the center, and 0.014 mm to 0.078 mm (1.86% to 10.25%) at the upper 16 cm, and the value of relative errors increased as it got farther from the center and as the number of wires went fewer. CONCLUSION: This study indicated that accurate measurement of SSP may be achieved by using 4 (arranged every 90 degrees) or more averaging wires.

Robotic distal gastrectomy plus spleen-preserving distal pancreatectomy: optimal resection for simultaneous gastric cancer and intraductal papillary mucinous neoplasm of the pancreatic body.

BACKGROUND: Organ-preserving surgery has recently gained increasing attention. However, performing the surgery for duplicated gastric and distal pancreatic tumors is difficult because of procedural complexity and concerns of remnant gastric necrosis. We present the first case of simultaneous robotic distal gastrectomy plus spleen-preserving distal pancreatectomy in a patient with overlapping gastric cancer and intraductal papillary mucinous neoplasm. CASE PRESENTATION: A 78-year-old man was diagnosed with gastric cancer in the middle stomach and intraductal papillary mucinous neoplasm of the pancreatic body. Radical cure surgery was performed using the da Vinci Xi robotic system. Conventional distal gastrectomy was initially completed using near-infrared ray guidance when transecting the stomach. After dividing the pancreas, the parenchyma of the distal pancreas was detached from the splenic artery and vein; multiple branches from these splenic vessels were dissected. Indocyanine green imaging confirmed sufficient blood flow in the splenic vessels and perfusion of the remnant stomach. Ultimately, gastrointestinal reconstruction was performed, and the postoperative course was uneventful. CONCLUSIONS: The robotic distal gastrectomy plus spleen-preserving distal pancreatectomy procedure was safely performed. Compared to the total gastrectomy plus distal pancreatectomy with splenectomy procedure, this technique may improve the quality of dietary life, reduce weight loss, and prevent complications associated with splenectomy.

Laparoscopic pancreas-preserving duodenectomy: Minimally invasive surgery for superficial nonampullary duodenal epithelial tumors.

No consensus exists regarding the optimal treatment for superficial nonampullary duodenal epithelial tumors. Herein, we describe a laparoscopic pancreas-preserving duodenectomy for the treatment of a 30-mm adenoma located in the third portion of the duodenum. The adenoma was located on the pancreatic side, further hindering safe endoscopic resection. Via laparoscopy, the jejunum was transected first. After releasing the third portion of the duodenum from the retroperitoneal space, the jejunum was pulled to the right side of the superior mesenteric artery and separated from the pancreas. Under endoscopic guidance, the duodenum was then transected and duodenojejunostomy performed intracorporeally. Laparoscopic pancreas-preserving duodenectomy can be considered minimally invasive, achieving tumor radicality while preserving organs and causing minimal destruction to the abdominal wall. In conclusion, although technically demanding, laparoscopic pancreas-preserving duodenectomy is a valuable treatment option for superficial nonampullary duodenal epithelial tumors.

Recent advances in the understanding of cilia mechanisms and their applications as therapeutic targets.

The primary cilium is a single immotile microtubule-based organelle that protrudes into the extracellular space. Malformations and dysfunctions of the cilia have been associated with various forms of syndromic and non-syndromic diseases, termed ciliopathies. The primary cilium is therefore gaining attention due to its potential as a therapeutic target. In this review, we examine ciliary receptors, ciliogenesis, and ciliary trafficking as possible therapeutic targets. We first discuss the mechanisms of selective distribution, signal transduction, and physiological roles of ciliary receptors. Next, pathways that regulate ciliogenesis, specifically the Aurora A kinase, mammalian target of rapamycin, and ubiquitin-proteasome pathways are examined as therapeutic targets to regulate ciliogenesis. Then, in the photoreceptors, the mechanism of ciliary trafficking which takes place at the transition zone involving the ciliary membrane proteins is reviewed. Finally, some of the current therapeutic advancements highlighting the role of large animal models of photoreceptor ciliopathy are discussed.

Recent Progress on Genetically Modified Animal Models for Membrane Skeletal Proteins: The 4.1 and MPP Families.

The protein 4.1 and membrane palmitoylated protein (MPP) families were originally found as components in the erythrocyte membrane skeletal protein complex, which helps maintain the stability of erythrocyte membranes by linking intramembranous proteins and meshwork structures composed of actin and spectrin under the membranes. Recently, it has been recognized that cells and tissues ubiquitously use this membrane skeletal system. Various intramembranous proteins, including adhesion molecules, ion channels, and receptors, have been shown to interact with the 4.1 and MPP families, regulating cellular and tissue dynamics by binding to intracellular signal transduction proteins. In this review, we focus on our previous studies regarding genetically modified animal models, especially on 4.1G, MPP6, and MPP2, to describe their functional roles in the peripheral nervous system, the central nervous system, the testis, and bone formation. As the membrane skeletal proteins are located at sites that receive signals from outside the cell and transduce signals inside the cell, it is necessary to elucidate their molecular interrelationships, which may broaden the understanding of cell and tissue functions.

Prediction of Anemia From Cerebral Venous Sinus Attenuation on Deep-Learning Reconstructed Brain Computed Tomography Images.

OBJECTIVE: The aim of the study is to evaluate whether the prediction of anemia is possible using quantitative analyses of unenhanced cranial computed tomography (CT) with deep learning reconstruction (DLR) compared with conventional methods. METHODS: This cross-sectional retrospective study included 116 participants (76 males; mean age, 66.7) who had hemoglobin (Hb) levels obtained within 24 hours of unenhanced cranial CT, which included 2 reconstruction methods: DLR and hybrid iterative reconstruction. Regions of interest were the confluence of sinuses (CoS) and the right and left transverse sinuses. In addition, edge rise distance of cerebrospinal fluid and venous was measured. RESULTS: Spearman rank correlation coefficient demonstrated a positive association between Hb levels and sinus attenuation values. Among these, the CoS in DLR had the best correlation ( r = 0.703, P < 0.001). For the prediction of anemia (Hb < 11 g/dL), the area under the curve of CoS in DLR (area under the curve = 0.874; 95% confidence interval, 0.798-0.949; P < 0.001) was the highest; however, there were no significant differences among reconstruction method and sinus. The attenuation values of DLR were significantly higher than those of hybrid iterative reconstruction ( P < 0.001, paired t test), and the differences between the 2 methods were 4.1 (standard deviation [SD], 1.6) for CoS, 5.2 (SD, 2.2) for right transverse sinuses, and 5.8 (SD, 2.4) for left transverse sinuses. The signal-to-noise ratio ( P < 0.001, paired t test) and edge rise distance ( P < 0.001, Wilcoxon signed rank test) of DLR was significantly higher. CONCLUSIONS: Higher CT attenuation values should be considered for predicting anemia based on brain DLR images.

MAST4 promotes primary ciliary resorption through phosphorylation of Tctex-1.

The primary cilium undergoes cell cycle-dependent assembly and disassembly. Dysregulated ciliary dynamics are associated with several pathological conditions called ciliopathies. Previous studies showed that the localization of phosphorylated Tctex-1 at Thr94 (T94) at the ciliary base critically regulates ciliary resorption by accelerating actin remodeling and ciliary pocket membrane endocytosis. Here, we show that microtubule-associated serine/threonine kinase family member 4 (MAST4) is localized at the primary cilium. Suppressing MAST4 blocks serum-induced ciliary resorption, and overexpressing MAST4 accelerates ciliary resorption. Tctex-1 binds to the kinase domain of MAST4, in which the R503 and D504 residues are key to MAST4-mediated ciliary resorption. The ciliary resorption and the ciliary base localization of phospho-(T94)Tctex-1 are blocked by the knockdown of MAST4 or the expression of the catalytic-inactive site-directed MAST4 mutants. Moreover, MAST4 is required for Cdc42 activation and Rab5-mediated periciliary membrane endocytosis during ciliary resorption. These results support that MAST4 is a novel kinase that regulates ciliary resorption by modulating the ciliary base localization of phospho-(T94)Tctex-1. MAST4 is a potential new target for treating ciliopathies causally by ciliary resorption defects.

Solo surgery in robot-assisted gastrectomy versus laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis.

BACKGROUND: Robot-assisted gastrectomy (RG) for gastric cancer is still not well standardized. This study aimed to explore the feasibility and effectiveness of solo surgery in robot-assisted gastrectomy (SRG) for gastric cancer compared to laparoscopic gastrectomy (LG). METHODS: This was a single-center retrospective comparative study between SRG and conventional LG. Between April 2015 and December 2022, 510 patients underwent gastrectomy, and data from a prospectively collected database were analyzed. We identified 372 patients who underwent LG (n = 267) and SRG (n = 105) and the remaining 138 patients were excluded because of remnant gastric cancer, esophagogastric junction cancer, open gastrectomy, concurrent surgery for concomitant malignancies, RG before starting SRG, or cases in which the author was unable to perform or supervise gastrectomy. Propensity score matching was performed at a ratio of 1:1 to reduce bias from confounding patient-related variables, and short-term outcomes were compared between the groups. RESULTS: After propensity score matching, 90 pairs of patients who underwent LG and SRG were selected. In the propensity-matched cohort, the operation time was significantly shorter in the SRG group than that in the LG group (SRG = 305.7 ± 74.0 min vs. LG = 340.3 ± 91.65 min, p < 0.0058), less estimated blood loss was observed in the SRG group than that in the LG group (SRG = 25.6 ± 50.6 mL vs. LG = 76.1 ± 104.2 mL, p < 0.0001) and postoperative hospital stay was shorter in the SRG group than that in the LG group (SRG = 7.1 ± 0.8 days vs. LG = 9.1 ± 7.7 days, p = 0.015). CONCLUSION: We found that SRG for gastric cancer was technically feasible and effective with favorable short-term outcomes, including shorter operative time, less estimated blood loss, shorter hospital stays, and lower postoperative morbidity than those in LG.

Simultaneous robotic distal gastrectomy and distal pancreatectomy: Avoiding total gastrectomy using indocyanine green fluorescence imaging.

Remnant gastric ischemia is the most significant complication in distal pancreatectomy (DP) after distal gastrectomy (DG). Some studies have reported the safety of asynchronous DP in patients who underwent DG. We report a case of simultaneous robotic DG and DP. A 78-year-old man was diagnosed with gastric and pancreatic cancer. We preoperatively confirmed the absence of anomalies in the left inferior phrenic artery. Robotic simultaneous DG and DP was performed; subtotal resection of the stomach was carried out, enabling the left inferior phrenic artery to maintain perfusion of the remnant stomach, even after ligation of the splenic artery. The remnant stomach was preserved as scheduled, and indocyanine green fluorescence imaging confirmed sufficient remnant stomach tissue perfusion. Robotic surgery using the da Vinci surgical system (with a fluorescence imaging system and technology enabling surgical precision) is suitable for this surgical procedure because it considers tumor radicality and allows for function preservation.

The cisplatin-induced acute kidney injury is a novel risk factor for postoperative complications in patients with esophageal cancer: a retrospective cohort study.

BACKGROUND: Cisplatin-induced acute kidney injury (AKI) is common during preoperative chemotherapy for esophageal cancer. The purpose of this study was to investigate the association between AKI after preoperative chemotherapy and postoperative complications in patients with esophageal cancer. METHODS: In this retrospective cohort study, we included patients who had received preoperative chemotherapy with cisplatin and underwent surgical resection for esophageal cancer under general anesthesia from January 2017 to February 2022 at an education hospital. A predictor was stage 2 or higher cisplatin-induced AKI (c-AKI) defined by the KDIGO criteria within 10 days after chemotherapy. Outcomes were postoperative complications and length of hospital stays. Associations between c-AKI and outcomes including postoperative complications and length of hospital stays were examined with logistic regression models. RESULTS: Among 101 subjects, 22 developed c-AKI with full recovery of the estimated glomerular filtration (eGFR) before surgery. Demographics were not significantly different between patients with and without c-AKI. Patients with c-AKI had significantly longer hospital stays than those without c-AKI [mean (95% confidence interval (95%CI)) 27.6 days (23.3-31.9) and 43.8 days (26.5-61.2), respectively, mean difference (95%CI) 16.2 days (4.4-28.1)]. Those with c-AKI had higher C-reactive protein (CRP) levels and prolonged weight gain after surgery and before the events of interest despite having comparable eGFR trajectories after surgery. c-AKI was significantly associated with anastomotic leakage and postoperative pneumonia [odds ratios (95%CI) 4.14 (1.30-13.18) and 3.87 (1.35-11.0), respectively]. Propensity score adjustment and inverse probability weighing yielded similar results. Mediation analysis showed that a higher incidence of anastomotic leakage in patients with c-AKI was primarily mediated by CRP levels (mediation percentage 48%). CONCLUSION: c-AKI after preoperative chemotherapy in esophageal cancer patients was significantly associated with the development of postoperative complications and led to a resultant longer hospital stay. Increased vascular permeability and tissue edema due to prolonged inflammation might explain the mechanisms for the higher incidence of postoperative complications.

Robotic gastrectomy for remnant gastric cancer after pancreaticoduodenectomy.

The utility of robotic surgery for remnant gastric cancer remains unclear. We report a case of a robotic gastrectomy for remnant gastric cancer after pancreaticoduodenectomy and Child reconstruction with Braun enteroenterostomy. Adhesiolysis, lymphadenectomy, and gastrectomy were robotically performed. Indocyanine green fluorescence imaging confirmed the tissue perfusion of the reconstructive tract. The patient's postoperative course was uneventful. Robotic surgery facilitates safety for gastrectomy after pancreaticoduodenectomy because of its precise manipulation; its advantages can be further exploited by maximizing usage of the assistant's forceps. Indocyanine green fluorescence imaging capability of the da Vinci Xi Surgical System allows timely evaluation of tissue perfusion at the site of interest, leading to a more reliable procedure.

Benefits of laparoscopic trans-hiatal approach with Heller-Dor surgery in a case of mid-esophageal diverticulum.

Compared to the more common epiphrenic diverticula, those located at the central section of the esophagus are quite rare. Minimally invasive approaches for mid-esophageal diverticula have lacked standardization. Certain mid-esophageal diverticula, like epiphrenic diverticula, have been attributed to esophageal motility disorders. Thus, we believe that surgery for esophageal diverticula requires preoperative evaluation of esophageal function, with additional surgery being performed in case of abnormalities. The laparoscopic trans-hiatal approach has been a common technique for managing epiphrenic diverticula but can also be used for mid-esophageal diverticula located far from the esophagogastric junction provided that the port location is carefully considered. Laparoscopic surgery is also preferable given that it is a minimally invasive procedure and allows for diverticulum resection and Heller myotomy and Dor surgery to prevent reflux in the same field of view. Hence, laparoscopic surgery may be a beneficial alternative to the traditional thoracic or thoracoabdominal techniques.

Laparoscopic gastrectomy for gastric cancer with two left gastric arteries: Safe and adequate lymphadenectomy in a rare arterial abnormality.

Clinical studies have established the safety and advantages of laparoscopic surgery for gastric cancer; therefore, laparoscopic gastrectomy (LG) in clinical practice is increasing. We report the case of a 77-year-old patient with gastric cancer who was referred to our center for LG. Esophagogastroduodenoscopy revealed a type 3 tumor identified as adenocarcinoma on biopsy. Three-dimensional computed tomography-angiography revealed two left gastric arteries (LGAs) branching from the celiac trunk. By laparoscopically performing the outermost layer-oriented lymphadenectomy (OML-OL), the two LGAs were detected and appropriately divided. Subtotal gastrectomy was completed, and the patient had an uneventful postoperative course. The OML-OL was appropriate for LG in this situation. This case demonstrates the necessity of preoperative three-dimensional computed tomography-angiography with 1-mm slices and the importance of performing OML-OL.

Doxorubicin induces cardiomyocyte death owing to the accumulation of dysfunctional mitochondria by inhibiting the autophagy fusion process.

Doxorubicin (Dox), an anthracycline antibiotic, is an anticancer drug that inhibits DNA replication and cellular metabolic processes in cancer cells with high proliferative potential. However, Dox causes severe side effects, including myocardial damage and heart failure, but the molecular mechanism underlying Dox-induced myocardial injury remains uncertain. In the present study, we evaluated the effects of Dox on the mitochondrial quality control system and regulation of mitochondrial respiration and autophagy in an in vitro rat myoblast H9c2 cell culture model using western blotting, immunohistochemistry, the Seahorse XF24 system, and flow cytometry. Our results showed that Dox did not impair the initiation of autophagic flux or the functions of lysosomes; however, Dox affected the mitochondrial quality control system, leading to a fission-dominant morphology and impaired regulation of mitochondrial respiration, thereby increasing oxidative stress and inhibited progression of autophagy, particularly the fusion of autophagosomes with lysosomes. This inhibition caused a significant decrease in the formation of autolysosomes and was responsible for the accumulation of dysfunctional mitochondria and subsequent increase in oxidative stress, eventually leading to increased myocardial cell death.

KLMab-1: An Anti-human KLRG1 Monoclonal Antibody for Immunocytochemistry.

Immune checkpoint molecules have received attention as targets of cancer immunotherapy. Killer cell lectin-like receptor subfamily G member 1 (KLRG1) is one of the immune checkpoint molecules expressed in CD4+ T, CD8+ T, and natural killer (NK) cells. KLRG1 exhibits antiviral and antitumor immunity, and its expression in T and NK cells is upregulated by viral infectious diseases and some tumors. Thus, monoclonal antibodies (mAbs) for KLRG1 would be useful tools for the diagnosis and immunotherapy against viral infectious diseases and cancers. We have developed anti-human KLRG1 (hKLRG1) mAb (clone KLMab-1, mouse IgG1, kappa) by the Cell-Based Immunization and Screening method. We have also demonstrated that KLMab-1 recognizes both exogenous and endogenous hKLRG1 in flow cytometry. In this study, we first showed that KLMab-1 and its recombinant mAb (recKLMab-1) bound to exogenous hKLRG1 overexpressed in Chinese hamster ovary (CHO)-K1 cells, but not in parental CHO-K1 cells, in immunocytochemistry. We next showed that both mAbs detected endogenous hKLRG1 expressed in human NK cells. These results demonstrate that KLMab-1 and recKLMab-1 are available for immunocytochemistry.

Development of an Anti-human CCR2 Monoclonal Antibody (C2Mab-9) by N-Terminal Peptide Immunization.

The CC chemokine receptor type-2 (CCR2) is one of the members of the G protein-coupled receptor superfamily, which are expressed on the cell surface of immune and tumor cells. CCR2 binds to the C-C motif chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP-1), which is produced by various cells, including tumor and immune-related cells. Therefore, the development of sensitive monoclonal antibodies (mAbs) for CCR2 has been desired for treatment and diagnosis. In this study, we established a specific antihuman CCR2 (hCCR2) mAb, C2Mab-9 (mouse IgG1, kappa), using the synthetic peptide immunization method. Flow cytometric and immunocytochemical results showed that C2Mab-9 reacted with hCCR2-expressing U937 (human histiocytic lymphoma) and natural killer cells. Furthermore, C2Mab-9 showed the moderate binding affinity for both cells. Conclusively, C2Mab-9 can be a useful tool for analyzing hCCR2-related biological responses.

Defucosylated mouse­dog chimeric anti­HER2 monoclonal antibody exerts antitumor activities in mouse xenograft models of canine tumors.

Human epidermal growth factor receptor 2 (HER2) overexpression has been reported in various types of cancer, including breast, gastric, lung, colorectal and pancreatic cancer. A humanized anti­HER2 monoclonal antibody (mAb), trastuzumab, has been shown to improve survival of patients in HER2­positive breast and gastric cancer. An anti­HER2 mAb, H2Mab­77 (mouse IgG1, kappa) was previously developed. In the present study, a defucosylated version of mouse­dog chimeric anti­HER2 mAb (H77Bf) was generated. H77Bf possesses a high binding­affinity [a dissociation constant (KD): 7.5x10­10 M, as determined by flow cytometric analysis] for dog HER2­overexpressed CHO­K1 (CHO/dHER2) cells. H77Bf highly exerted antibody­dependent cellular cytotoxicity (ADCC) and complement­dependent cytotoxicity (CDC) for CHO/dHER2 cells by canine mononuclear cells and complement, respectively. Moreover, administration of H77Bf significantly suppressed the development of CHO/dHER2 xenograft tumor in mice compared with the control dog IgG. H77Bf also possesses a high binding­affinity (KD: 7.2x10­10 M) for a canine mammary gland tumor cell line (SNP), and showed high ADCC and CDC activities for SNP cells. Intraperitoneal administration of H77Bf in mouse xenograft models of SNP significantly suppressed the development of SNP xenograft tumors compared with the control dog IgG. These results indicated that H77Bf exerts antitumor activities against dHER2­positive canine cancers, and could be valuable treatment regimen for canine cancers.

TgMab-2: An Anti-human T Cell Immunoglobulin and Immunoreceptor Tyrosine-Based Inhibitory Motif Domain Monoclonal Antibody for Immunocytochemistry.

T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is one of the immune checkpoint molecules. TIGIT is expressed in T or natural killer (NK) cells and is upregulated in several cancers. Because TIGIT suppresses the antitumor activity of the T or NK cells by binding to its ligand, such as CD155, CD112, and CD113, TIGIT can be a molecular marker or a therapeutic target for cancer immunotherapy. We previously developed an anti-human TIGIT (hTIGIT) monoclonal antibody (mAb; clone TgMab-2; mouse IgG1, kappa) by the Cell-Based Immunization and Screening method. TgMab-2 binds to hTIGIT with high binding affinity in flow cytometry. In this study, we investigated the availability of TgMab-2 and its recombinant mAb (recTgMab-2) in immunocytochemistry. We found that TgMab-2 and recTgMab-2 bind to hTIGIT-overexpressed Chinese hamster ovary (CHO)-K1 cells, but not parental CHO-K1 cells, indicating that both mAbs specifically recognize hTIGIT. Furthermore, both mAbs recognized endogenous hTIGIT expressed in human NK cells in immunocytochemistry. These results demonstrate that TgMab-2 and recTgMab-2 are applicable for immunocytochemistry against hTIGIT.