Functional analysis of a first hindlimb positioning enhancer via Gdf11 expression.

During the early development of tetrapods, including humans, the embryonic body elongates caudally once the anterior-posterior axis is established. During this process, region-specific vertebral morphogenesis occurs, with the determination of limb positioning along the anterior-posterior axis. We previously reported that Gdf11 functions as an anatomical integration system that determines the positioning of hindlimbs and sacral vertebrae where Gdf11 is expressed. However, the molecular mechanisms underlying induction of Gdf11 expression remain unclear. In this study, we searched for non-coding regions near the Gdf11 locus that were conserved across species to elucidate the regulatory mechanisms of Gdf11 expression. We identified an enhancer of the Gdf11 gene in intron 1 and named it highly conserved region (HCR). In HCR knockout mice, the expression level of endogenous Gdf11 was decreased, and the position of the sacral-hindlimb unit was shifted posteriorly. We also searched for factors upstream of Gdf11 based on the predicted transcription factor binding sites within the HCR. We found that inhibition of FGF signaling increased endogenous Gdf11 expression, suggesting that FGF signaling negatively regulates Gdf11 expression. However, FGF signaling does not regulate HCR activity. Our results suggest that there are species-specific Gdf11 enhancers other than HCR and that FGF signaling regulates Gdf11 expression independent of HCR.

Malignancy After Living Donor Liver Transplantation.

OBJECTIVES: De novo malignancy (DNM) is a major cause of death in long-term recipients of liver transplantation (LT). We herein report our experience with DNM after living-donor LT (LDLT). PATIENTS AND METHODS: A total of 111 LDLT procedures were performed in our institute from 1999 to 2022. Among them, 70 adult (>13 years old) LDLT recipients who survived for more than 1 year were included in this study. RESULTS: During a median follow-up of 146 (range, 12-285) months, 7 out of 70 recipients developed 8 DNMs, including lung cancer in 4, post-transplant lymphoproliferative disease in 3, and skin cancer in 1. One patient developed metachronal skin cancer and post-transplant lymphoproliferative disease. The pre-LT smoking history rate in patients with DNM was higher than in patients without DNM (P = .004). The survival time after DNM was 6 (1-166) months. Only 2 patients underwent R0 resection. DNM did not recur during follow-up. Other patients who underwent R1 resection and/or chemotherapy and/or radiotherapy all died due to DNMs during the follow-up. The cumulative DNM incidence was 3.5% at 10 years and 18.4% at 20 years after LDLT. The cumulative survival rate in patients with DNM was significantly worse than that in patients without DNM after LDLT (P = .049). CONCLUSION: The survival rate of patients with DNM was lower than that of those without DNM. A pre-LT smoking history is a risk factor for DNM. R0 resection is effective for improving the prognosis of patients with DNM. Regular cancer screening is important for detecting DNM early after LDLT.

[Radical Resection Followed by Chemotherapy for Intrahepatic Cholangiocarcinoma with Lymph Node Metastases-Report of a Long-Term Survivor].

We report a case of intrahepatic cholangiocarcinoma(ICC)with lymph node metastases in which long-term survival was achieved after surgery followed by chemotherapy. A 69-year-old man underwent left hepatectomy, extrahepatic bile duct resection, and lymph node dissection for ICC located mainly in segment 4 of the liver with enlarged lymph nodes in the hepatoduodenal ligament. The histopathologically confirmed diagnosis was ICC(T2N1M0, Stage ⅣA)with 3 positive lymph nodes(No. 12a1, No. 12p1, and No. 12p2). He received chemotherapy with gemcitabine(GEM)plus cisplatin(CDDP)for 9 months, followed by GEM monotherapy for 4 months, and then S-1 monotherapy was started. A right lung nodule was detected 12 months after the initiation of S-1 monotherapy. He received GEM plus S-1 therapy for 28 months, followed by S-1 monotherapy, leading to disappearance of the lung nodule. He remains alive and well without disease 78 months after surgery. Our experience in this case suggests that radical resection followed by chemotherapy may provide a survival benefit in selected patients who have ICC with nodal disease.

Users' adaptations to the proportional speed control of a motorised walker.

PURPOSE: Speed control is commonly used to regulate the forces applied by motorised walkers (MW) and there are often situations where the speed targeted deviates from the preferred walking speed of its users, such as when encouraging higher walking speeds and due to safety consideration. This study investigates the effects of different MW's target speeds on the selected walking speeds, force applied, perceived exertion, and gait of MW users during steady-state walking. MATERIALS AND METHODS: The spatiotemporal gait parameters and perceived exertion of twenty young healthy participants were measured as they walked at a comfortable, self-selected speed using a MW as it was controlled to target forward speeds of 0.6, 0.8, 1.0, 1.2, and 1.4 m s-1 as well as when no assistive force was applied by the MW. RESULTS: On average, users would walk slower when their "No Assist" walking speed is higher than the MW's speed target and vice versa. Additionally, the force applied to the MW is proportional to the difference in speed, either faster or slower, when compared to "No Assist". CONCLUSION: The user's exertion and the energy used by the MW are both minimised when target speed is close to the preferred walking speed of the user. Additionally, these findings suggest that the speed target can be used to change the walking speed of users but only to a certain extend and at the cost of higher perceived exertion.Implications for rehabilitationThe larger the difference between the target speed of the MW and the preferred walking speed of the user, the more likely the user is to push or pull on the MW.Users would push or pull on the MW with a force proportional to the difference from their preferred walking speed even when matching the MW's target speed.Users can be encouraged to walk at higher than preferred speeds, even though this would come at the cost of higher perceived exertion.

Preoperative controlling nutritional status score predicts systemic disease recurrence in patients with resectable biliary tract cancer.

INTRODUCTION: This study aimed to evaluate the association between the preoperative Controlling Nutritional Status (CONUT) score, survival outcomes, and recurrence pattern in patients with resectable biliary tract cancer (BTC). METHODS: A total of 224 BTC patients (gallbladder, n = 69; intrahepatic bile ducts, n = 26; perihilar bile ducts, n = 72; distal bile duct, n = 57) who underwent surgery with curative intent were enrolled. The best cutoff point of the preoperative CONUT score in discriminating survival was determined using χ2 scores. The sites of recurrence were subclassified as locoregional or distant. RESULTS: Patients were subdivided into the CONUT-low (score ≤ 3, n = 156) and the CONUT-high (score > 3; n = 68) groups. In-hospital mortality occurred more frequently in the CONUT-high group than in the CONUT-low group (7.4% vs. 1.3%; p = 0.028). A high preoperative CONUT score was independently associated with worse overall survival (hazard ratio [HR] 1.906, p = 0.001), worse disease-specific survival (HR 1.840, p = 0.006), and worse recurrence-free survival (HR 1.680, p = 0.005). Recurrence developed in 110 (49.1%) patients. A high preoperative CONUT score was independently associated with a higher risk of distant recurrence (HR 2.245, p = 0.001), but not locoregional recurrence. The incidences of distant recurrence at 5 years were 55.4% and 34.2% in the CONUT-high and CONUT-low groups, respectively (p = 0.001). CONCLUSIONS: The preoperative CONUT score independently predicts survival outcomes and may serve as a surrogate marker of aggressive systemic disease recurrence in patients with resectable BTC.

[Surgery for Cholangiocarcinoma with Superficial Spread and Lymph Node Metastasis-Report of a Long-Term Survivor Who Had Positive Proximal Ductal Resection Margins with Carcinoma In Situ].

A 66-year-old man was referred to our hospital with fever and abdominal pain. CT showed a mass in the intrapancreatic bile duct but no wall thickness in the perihilar bile ducts. Neither regional lymphadenopathy nor distant metastasis was observed. Biliary cytology showed adenocarcinoma. The diagnosis was distal cholangiocarcinoma, and pancreatoduodenectomy was performed. Intraoperative frozen section examination of the ductal resection margins at the right and left hepatic ducts was positive for carcinoma in situ, and the operation ultimately completed with R1 resection. Histological examination confirmed a diagnosis of cholangiocarcinoma with superficial spread and a single positive lymph node. Adjuvant chemotherapy with S-1 was administered for 1 year. Anastomotic recurrence at the hepaticojejunostomy was found 5 years after resection; biopsy specimens revealed adenocarcinoma. Thereafter, S-1 chemotherapy was resumed, and the patient remains alive and well 9 years and 1 month after resection.

[A Case of Intraductal Papillary Mucinous Adenocarcinoma with Hepatic Dysfunction Due to Tumor Perforation into the Bile Duct].

A 58-year-old woman presented with a complaint of weight loss. Abdominal computed tomography showed dilatation of the biliary and pancreatic ducts and a mural nodule in the pancreatic duct. The diagnosis was intraductal papillary mucinous neoplasm(IPMN). Endoscopic retrograde cholangiopancreatography(ERCP)and cholangioscopy revealed a fistula between the common bile duct and the IPMN. A sudden increase in hepatobiliary enzymes was noted preoperatively. ERCP showed that the common bile duct was obstructed by mucus. A nasobiliary drainage tube was inserted into the bile duct endoscopically and kept open by daily tube washing, and the liver dysfunction improved. Total pancreatectomy, splenectomy, and regional lymph node dissection were performed. Histological examination confirmed that the primary tumor was mixed invasive intraductal papillary mucinous adenocarcinoma. The patient remains alive and well with no evidence of recurrence 18 months after resection.

[Two Operations for Intrahepatic Recurrence of Biliary Cystadenocarcinoma-A Long-Term Survivor].

We report a case of biliary cystadenocarcinoma in which long-term survival was achieved after 2 operations for intrahepatic recurrence. A 72-year-old man with biliary cystadenocarcinoma located mainly in segment 3 of the liver underwent left hepatectomy, extrahepatic bile duct resection, and lymph node dissection. Seven years and 9 months after the initial resection, he underwent partial liver resection(segment 5)for intrahepatic recurrence detected by computed tomography. Fifteen years and 7 months after the initial resection, he underwent repeat partial resection of the liver(segment 5)for intrahepatic recurrence. Histologically, these tumors were confirmed to be recurrence of biliary cystadenocarcinoma. He remains alive and well with no further recurrence 21 years and 6 months after the initial resection. This case and a literature review suggest that hepatic resection is a useful treatment option for intrahepatic recurrence of biliary cystadenocarcinoma.

Immune checkpoint inhibitor therapy and elevated levels of C-reactive protein associated with COVID-19 aggravation in patients with lung cancer.

BACKGROUND: COVID-19 has become a significant health threat and a primary healthcare concern among the most vulnerable patients with cancer. Patients with COVID-19 who have lung cancer are at great risk and need careful monitoring if they are affected. This study aimed to investigate the clinical characteristics of COVID-19-positive patients with lung cancer and the risks associated with anticancer medication. METHODS: This study was a single-center, retrospective cohort study. Patients with lung cancer who presented with COVID-19 during hospitalization were divided into two groups: those who presented with respiratory failure and those who did not. The patient's background, clinical laboratory values, and anticancer drugs used for therapy were investigated to identify risk factors for respiratory failure. RESULTS: Thirty-one patients were included in the study; 18 (58.1%) were in the respiratory failure group and 13 (41.9%) were in the group without respiratory failure. In the respiratory failure group, there was a significant difference in using immune checkpoint inhibitor (ICI) use within 90 days (p = 0.025) and the level of C-reactive protein (CRP) level (p = 0.017). The analysis of the operating characteristic of the receiver revealed a cutoff value of 2.75 mg/dL for CRP (area under the curve = 0.744, sensitivity 0.611, specificity 0.923). CONCLUSIONS: A history of ICI within 90 days and elevated CRP (≥ 2.75 mg/dL) levels are potential factors leading to respiratory failure in COVID-19-affected patients undergoing chemotherapy for lung cancer.

Incisional Hernia Repaired Using Thigh Muscle Fascia After Kidney Transplantation: A Case Report.

BACKGROUND: Although monofilament mesh-based repair is a safe and effective procedure for incisional hernia (IH) in organ transplant patients, there is no definite evidence of IH treatment for patients with graft rejection and enhanced immunosuppressive therapy. We report a successful case of large IH repair using an autologous thigh muscle fascia sheet in a kidney transplant patient. CASE PRESENTATION: A 69-year-old man had IH from the incision of kidney transplantation, which was performed 6 years ago. He had a large right lower abdominal distension hanging down to the inguinal portion. A computed tomography scan revealed a large IH with a maximum abdominal defect diameter of 15 cm. The hernia sac contained the intestine, colon, and transplanted kidney, which had pulled out along with the retroperitoneum and protruded into the abdominal wall. He had chronic active acute antibody-mediated rejection, which required frequent steroid pulse therapy and additional or adjusted immunosuppressive drugs. After total circumferential exposure of the hernia sac and abdominal fascia, the abdominal wall defect was closed using a horizontal mattress suture. The sutured line was covered with a thigh muscle fascia sheet harvested from the patient's right femur and attached to the closed fascia. He was discharged on postoperative day 13 without any complications, and no IH recurrence was observed 10 months after surgery. CONCLUSIONS: Hernia repair using autologous tissue could be a treatment option for post-transplant IH with a higher risk of infection.

The effect of horizontal forces from a Smart Walker on gait and perceived exertion.

Increasingly, electric motors are being incorporated into wheeled walkers to implement various smart features to better assist their users physically. These modified walkers, known as Smart Walkers, use their electric motors to generate horizontal forces that can be used to reduce the physical load for walking, prevent falls and provide navigation support. However, these forces can also alter gait and may inadvertently increase the exertion of the users. This study aims to describe the effects of assistive and resistive horizontal forces (from -18.47 N to 27.70 N) from a Smart Walker on gait and perceived exertion of its users during steady-state walking. Self-selected comfortable walking speed, cadence, stride length, double support phase and ratings of perceived exertion (RPE) were significantly affected and different effects were found for resistive force, relatively low assistive force and high assistive force. With increasing force from -18.47 N to 0 N, RPE decreased and the users walked with lower double support time. From 0 N to 9.23 N, RPE continued to decrease to its lowest point while gait parameters remained constant. Further increasing force up to 27.70 N increased RPE and led to the users to choose to walk at higher speeds. This study demonstrates that users adapt their gait significantly to the forces applied and relatively high constant forces, whether assistive or resistive, will increase perceived exertion. Hence, these need to be carefully considered when developing Smart Walkers in order to provide safe and effective support to its users.

Screening of Fabry disease in patients with chronic kidney disease in Japan.

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder caused by a deficiency in alfa-galactosidase A (α-Gal A) activity due to mutations in the GLA gene, has a prevalence of 0-1.69% in patients undergoing haemodialysis; however, its prevalence in patients with chronic kidney disease (CKD) Stages 1-5 is unknown. METHODS: Serum α-Gal A activity analysis and direct sequencing of GLA were used to screen for FD in 2122 male patients with CKD, including 1703 patients with CKD Stage 5D and 419 with CKD Stages 1-5. The correlation between serum α-Gal A activity and confounding factors in patients with CKD Stages 1-5 was evaluated. RESULTS: FD prevalence rates in patients with CKD Stage 5D and CKD Stages 1-5 were 0.06% (1/1703) and 0.48% (2/419), respectively. A patient with CKD Stage 5D exhibited a novel GLA mutation, p.Met208Arg, whereas two patients with CKD Stages 1-5 had c.370delG and p.Met296Ile. p. Met208Arg caused moderate structural changes in the molecular surface region near the substituted amino acid residue but did not affect the catalytic residues Asp170 and Asp231 in α-Gal A. Serum α-Gal A activity in patients with CKD Stages 1-5 was inversely correlated with age (P < 0.0001) but directly correlated with estimated glomerular filtration rate (P < 0.0001). CONCLUSIONS: FD prevalence was much higher in male patients with CKD Stages 1-5 than in those with CKD Stage 5D. FD screening in patients with CKD Stages 1-5 may improve patient survival, decreasing the number of patients with CKD Stage 5D.

How do signaling and transcription factors regulate both axis elongation and Hox gene expression along the anteroposterior axis?

In vertebrates, vertebral primordia, called somites, are formed from the head to the tail along the anteroposterior axis of the body during development. The presomitic mesoderm (PSM), which differentiates into somites, is formed by continuous supply of new cells derived from the caudal lateral epiblast (CLE), resulting in body axis posterior elongation. Previous studies of mutants identified genes for posterior extension and vertebral patterning along the anteroposterior axis. Hox gene has been extensively investigated for its expression pattern and transcriptional regulation. In recent years, to elucidate the mechanism that controls the expression patterns of Hox genes, researchers have not only searched for enhancer regions and the transcription factors that bind to them but have also investigated chromatin structure, epigenetics and non-coding RNA associated with Hox gene expression. These new findings reveal that the previously identified genes essential for posterior body axis elongation of the embryo determine positional information along the anteroposterior axis by induction of Hox genes via enhancer regions. In this review, we focus on genes that control posterior elongation and vertebral patterning along the anteroposterior axis in the PSM and CLE. We first describe the mechanism of maintenance of the stem cell-like cell populations at the CLE, which is essential for the posterior elongation of the embryo. Next, the factors involved in posterior region formation and patterning of the vertebra are described. Finally, we discuss the regulatory mechanism of Hox gene expression and the mechanism that is responsible for the differences in skeletal pattern between species.

Engineering a human IgG2 antibody stable at low pH.

IgG2 subclass antibodies have unique properties that include low effector function and a rigid hinge region. Although some IgG2 subclasses have been clinically tested and approved for therapeutic use, they have a higher propensity than IgG1 for aggregation, which can curtail or abolish their biological activity and enhance their immunogenicity. In this regard, acid-induced aggregation of monoclonal antibodies during purification and virus inactivation must be prevented. In the present study, we replaced the constant domain of IgG2 with that of IgG1, using anti-2,4-dinitrophenol (DNP) IgG2 as a model antibody, and investigated whether that would confer greater stability. While the anti-DNP IgG2 antibody showed significant aggregation at low pH, this was reduced for the IgG2 antibody containing the IgG1 CH2 domain. Substituting three amino acids within the CH2 domain-namely, F300Y, V309L, and T339A (IgG2_YLA)-reduced aggregation at low pH and increased CH2 transition temperature, as determined by differential scanning calorimetric analysis. IgG2_YLA exhibited similar antigen-binding capacity to IgG2, low affinity for FcγRIIIa, and low binding ability to C1q. The same YLA substitution also reduced the aggregation of panitumumab, another IgG2 antibody, at low pH. Our engineered human IgG2 antibody showed reduced aggregation during bioprocessing and provides a basis for designing improved IgG2 antibodies for therapeutic applications.

R409K mutation prevents acid-induced aggregation of human IgG4.

Human immunoglobulin G isotype 4 (IgG4) antibodies are suitable for use in either the antagonist or agonist format because their low effector functions prevent target cytotoxicity or unwanted cytokine secretion. However, while manufacturing therapeutic antibodies, they are exposed to low pH during purification, and IgG4 is more susceptible to low-pH-induced aggregation than IgG1. Therefore, we investigated the underlying mechanisms of IgG4 aggregation at low pH and engineered an IgG4 with enhanced stability. By swapping the constant regions of IgG1 and IgG4, we determined that the constant heavy chain (CH3) domain is critical for aggregate formation, but a core-hinge-stabilizing S228P mutation in IgG4 is insufficient for preventing aggregation. To identify the aggregation-prone amino acid, we substituted the CH3 domain of IgG4 with that of IgG1, changing IgG4 Arg409 to a Lys, thereby preventing the aggregation of the IgG4 variant as effectively as in IgG1. A stabilizing effect was also recorded with other variable-region variants. Analysis of thermal stability using differential scanning calorimetry revealed that the R409K substitution increased the Tm value of CH3, suggesting that the R409K mutation contributed to the structural strengthening of the CH3-CH3 interaction. The R409K mutation did not influence the binding to antigens/human Fcγ receptors; whereas, the concurrent S228P and R409K mutations in IgG4 suppressed Fab-arm exchange drastically and as effectively as in IgG1, in both in vitro and in vivo in mice models. Our findings suggest that the IgG4 R409K variant represents a potential therapeutic IgG for use in low-effector-activity format that exhibits increased stability.

[A Case of Ascending Colon Cancer with Essential Thrombocythemia].

Essential thrombocythemia(ET)is a rare myeloproliferative disorder characterized by thrombocytosis and a risk of thrombotic and hemorrhagic events. ET rarely occurs simultaneously with colorectal cancer. Including our case, only 5 cases of c o l orectal cancer with ET have been reported in Japan. Herein, we report a case of colon cancer in an ET patient who underwent laparoscopic right hemicolectomy. Our perioperative management avoided complications such as thrombosis or bleeding. An 81-year-old woman developed bloody stools. She was previously diagnosed with ET 9 years ago. Aspirin, cilostazol, and hydroxyurea(HU)were prescribed. Colonoscopy revealed a tumor at the ascending colon. Histopathological examination showed a well-differentiated tubular adenocarcinoma. Since the patient had anemia, aspirin and cilostazol were discontinued after diagnosis. HU was discontinued from the day before surgery to 2 days after surgery. Enoxaparin was subcutaneously administered for 1 to 3 days after surgery. Aspirin and cilostazol were resumed on the fourth day post-surgery. The patient could be discharged when her condition stabilizes with no thrombosis and bleeding after 8 days.

Understanding the Molecular Mechanism Underlying the High Catalytic Activity of p-Hydroxybenzoate Hydroxylase Mutants for Producing Gallic Acid.

p-Hydroxybenzoate hydroxylase (PHBH) is a flavoprotein monooxygenase that catalyzes the hydroxylation of p-hydroxybenzoate (p-OHB) to 3,4-dihydroxybenzoate (3,4-DOHB). PHBH can bind to other benzoate derivatives in addition to p-OHB; however, hydroxylation does not occur on 3,4-DOHB. Replacement of Tyr385 with Phe forms a mutant, which enables the production of 3,4,5-trihydroxybenzonate (gallic acid) from 3,4-DOHB, although the catalytic activity of the mutant is quite low. In this study, we report how the L199V/Y385F double mutant exhibits activity for producing gallic acid 4.3-fold higher than that of the Y385F single mutant. This improvement in catalytic activity is primarily due to the suppression of a shunt reaction that wastes reduced nicotinamide adenine dinucleotide phosphate by producing H2O2. To further elucidate the molecular mechanism underlying this higher catalytic activity, we performed molecular dynamics simulations and quantum mechanics/molecular mechanics calculations, in addition to determining the crystal structure of the Y385F·3,4-DOHB complex. The simulations showed that the Y385F mutation facilitates the deprotonation of the 4-hydroxy group of 3,4-DOHB, which is necessary for initiating hydroxylation. Moreover, the L199V mutation in addition to the Y385F mutation allows the OH moiety in the peroxide group of C-(4a)-flavin hydroperoxide to come into the proximity of the C5 atom of 3,4-DOHB. Overall, this study provides a consistent explanation for the change in the catalytic activity of PHBH caused by mutations, which will enable us to better design an enzyme with different activities.

Identification of transgene integration site and anatomical properties of fluorescence intensity in a EGFP transgenic chicken line.

Transgenic birds are commonly used for time-lapse imaging and fate mapping studies in developmental biology. When researchers use transgenic birds expressing fluorescent protein, they need to understand the integration site of the transgene in the genome and the intensity of fluorescence in the tissues of interest. In this study, we determined the integration site of the transgene and fluorescence property of developing organs in our transgenic chicken line generated by lentivirus infection. The transgene was localized between exons 3 and 4 of MED27. Some homozygotes and heterozygotes appeared to be lethal at early embryonic stages. We performed histological analysis of EGFP expression in transgenic embryos at St. 14, 17, and 24 by immunohistochemistry with anti-GFP antibody on paraffin sections. Next, we cut cryosections and quantified direct EGFP intensity from the transgene in each tissue without performing immunohistochemistry. These results revealed that EGFP intensity in each tissue was unique in developing embryos and changed according to developmental stages. Finally, we demonstrated that EGFP-expressing cells in a micromass culture with co-culturing wild-type cells were clearly distinguishable via live cell imaging. These results provide essential information on the potential of our transgenic line and indicate that these transgenic chicken lines are useful for research associated with developmental biology.