Safety and feasibility of in-hospital autonomous transportation using a driverless mobility for patients with musculoskeletal disorders: preliminary clinical study to achieve mobility as a service in medical care.

BACKGROUND: Recent advancements in and the proliferation of autonomous mobility technology, such as intelligent wheelchairs, have made it possible to provide mobility services for patients with reduced mobility due to musculoskeletal disorders. In the present study, we conducted a preliminary clinical study to assess the safety and feasibility of in-hospital autonomous transportation using a driverless mobility (wheelchair) for patients with musculoskeletal disorders. METHODS: From January to February 2022, 51 patients with musculoskeletal disorders exhibiting gait disturbance who presented to our institution were included in the present study. Driverless mobility rides were conducted over a straight-line distance of 100 m from the orthopaedic outpatient reception to the payment counter after the outpatient consultation. We assessed the quality of life using an EQ-5D-5 L index and pain using a VAS score before riding the mobility to investigate the patient's condition. After the ride, a questionnaire survey was conducted to assess patient satisfaction on a 5-point scale. In addition, adverse events during the mobility ride were investigated. RESULTS: Overall satisfaction levels showed that 44 out of 51 (86%) patients rated the level as 3 or higher. There were no significant differences in the level of satisfaction based on the cause of disorders or EQ-5D-5 L Index. Among 19 patients who rated the level of satisfaction as 2-3, the ratio of postoperative patients and those with pain tended to be higher (p < 0.05). While 26 of 51 (51%) patients reported moments of feeling unsafe during the mobility ride, no actual adverse events, such as collisions, were observed. CONCLUSIONS: An in-hospital autonomous transportation service using a driverless mobility for patients with musculoskeletal disorders demonstrated high satisfaction levels and was safe with no severe adverse events observed. The expansion of autonomous mobility deployment is expected to achieve mobility as a service in medical care.

Efficacy and Safety Evaluation of Energy Devices in Bench Surgery for Pancreas Transplantation.

INTRODUCTION: Bench surgery for the preparation of deceased donor pancreatic grafts is labor-intensive and time-consuming. We hypothesized that energy devices could be used during bench surgery to decrease the bench surgery time. However, because bench surgery has two unique characteristics, wet conditions and no blood flow in the vessels, it is necessary to verify the safety and efficacy under such conditions. METHODS: In an animal tissue model, we validated both ultrasonic and bipolar energy devices: Harmonic Shears and the LigaSure (LS) vessel-sealing device by evaluating heat spread and pressure resistance under bench surgery conditions. In a clinical evaluation of the LS, we compared the outcomes of 22 patients in two different bench surgery groups: with and without the use of the LS. RESULTS: Clinically, the bench surgery time was significantly shorter in the LS group than that in the conventional group (P < 0.001). In the animal tissue experiments, the highest temperature in bench surgery conditions was 60.4°C after 1 s at a 5-mm distance in the LS group. Pressure resistance of ≥ 750 mmHg was achieved in almost all trials in both veins and arteries, with no difference between Harmonic Shears and LS. There was more surgical smoke visually in bench conditions versus in dry conditions and under half bite versus full bite conditions. CONCLUSIONS: The encouraging results of our exploratory clinical and animal studies of the energy devices suggest that they may be useful in the setting of bench surgery.

Curvature sensing of curvature-inducing proteins with internal structure.

Many types of peripheral and transmembrane proteins can sense and generate membrane curvature. Laterally isotropic proteins and crescent proteins with twofold rotational symmetry, such as Bin/Amphiphysin/Rvs superfamily proteins, have been studied theoretically. However, proteins often have an asymmetric structure or a higher rotational symmetry. We studied theoretically the curvature sensing of proteins with asymmetric structures and structural deformations. First, we examined proteins consisting of two rodlike segments. When proteins have mirror symmetry, their sensing ability is similar to that of single-rod proteins; hence, with increasing protein density on a cylindrical membrane tube, a second- or first-order transition occurs at a middle or small tube radius, respectively. As asymmetry is introduced, this transition becomes a continuous change and metastable states appear at high protein densities. Protein with threefold, fivefold, or higher rotational symmetry has laterally isotropic bending energy. However, when a structural deformation is allowed, the protein can have a preferred orientation and stronger curvature sensing.

A Single-Center Retrospective Study of Re-Transplantation After Allograft Failure in Kidney Transplant Recipients.

BACKGROUND: This study aimed to examine the outcomes of kidney retransplantation in patients with allograft failure at Kyushu University. METHODS: We reviewed data from 1043 consecutive patients (including 1001 in a first kidney transplantation [KT] group and 42 in a second KT group) who had undergone KT alone at our institution between January 2008 and September 2022. We also studied immunologic risks and outcomes of patients who had undergone preoperative testing for KT at Kyushu University during the same period. RESULTS: No patient received more than 2 transplants. Donor-specific anti-HLA antibody (DSA) had been detected in a greater percentage of patients in the second KT group than in the first (31% vs 11%, respectively; P < .001). There were no significant differences in 5-year death-censored/overall graft survival rates, rates of surgical complications, or incidence of delayed graft function between the groups. During the study period, significantly more candidates for second than first KT were rejected for this procedure because of their high immunologic risk (20% vs 2%, P < 001). Seven of the 42 patients in the second KT group required the removal of the primary graft during the second transplantation. CONCLUSION: There is a higher percentage of patients whose DSA has been detected among patients undergoing retransplantation after allograft failure than among those receiving first KTs, which often leads to remaining on the waiting list in the former group. However, if the immunologic risk is within acceptable limits, the graft survival for retransplantation is not inferior to that of a first KT.

Outcomes and Cost Comparison of 3 Different Laparoscopic Approach for Living Donor Nephrectomy: A Retrospective, Single-Center, Inverse Probability of Treatment Weighting Analysis of 551 Cases.

BACKGROUND: At our institution, we switched from hand-assisted retroperitoneal laparoscopic donor nephrectomy (HRN) to hand-assisted transperitoneal laparoscopic donor nephrectomy (HTN); we later switched to standard retroperitoneal laparoscopic donor nephrectomy (SRN). This study was performed to evaluate outcomes and hospital costs among the 3 techniques. METHODS: This retrospective, observational, single-center, inverse probability of treatment weighting analysis study compared the outcomes among 551 cases of living donor kidney transplantation between 2014 and 2022. RESULTS: After the inverse probability of treatment weighting analysis, there were 114 cases in the HRN group, 204 cases in the HTN group, and 213 cases in the SRN group. Donor complication rates were lowest in the SRN group but did not differ between the HRN and HTN groups (1.1 vs 4.4 and 5.9%, P = .021). Donors in the SRN group had the lowest serum C-reactive protein concentrations on postoperative day 1 (4.3 vs 10.5 and 7.8 mg/dL, P < .001) and the shortest postoperative stay (4.3 vs 7.4 and 8.4 days, P < .001). Donors in the SRN group had the lowest total cost among the 3 groups (8868 vs 9709 and 10,592 USD, P < .0001). Donors in the SRN group also had the lowest costs in terms of "basic medical fees," "medication and injection fees," "Intraoperative drug and material costs," and "testing fees." Furthermore, the presence of complications was significantly correlated with higher total hospital costs (P < .001). CONCLUSION: SRN appeared to have the least invasive and complication, and a potential cost savings compared with the HRN and HTN.

Single Person Identification and Activity Estimation in a Room from Waist-Level Contours Captured by 2D Light Detection and Ranging.

To develop socially assistive robots for monitoring older adults at home, a sensor is required to identify residents and capture activities within the room without violating privacy. We focused on 2D Light Detection and Ranging (2D-LIDAR) capable of robustly measuring human contours in a room. While horizontal 2D contour data can provide human location, identifying humans and activities from these contours is challenging. To address this issue, we developed novel methods using deep learning techniques. This paper proposes methods for person identification and activity estimation in a room using contour point clouds captured by a single 2D-LIDAR at hip height. In this approach, human contours were extracted from 2D-LIDAR data using density-based spatial clustering of applications with noise. Subsequently, the person and activity within a 10-s interval were estimated employing deep learning techniques. Two deep learning models, namely Long Short-Term Memory (LSTM) and image classification (VGG16), were compared. In the experiment, a total of 120 min of walking data and 100 min of additional activities (door opening, sitting, and standing) were collected from four participants. The LSTM-based and VGG16-based methods achieved accuracies of 65.3% and 89.7%, respectively, for person identification among the four individuals. Furthermore, these methods demonstrated accuracies of 94.2% and 97.9%, respectively, for the estimation of the four activities. Despite the 2D-LIDAR point clouds at hip height containing small features related to gait, the results indicate that the VGG16-based method has the capability to identify individuals and accurately estimate their activities.

Estimation of Wound Area and Severity Level of Skin tear using Deep Learning Methods.

Skin tears occur mainly in older adults, making it difficult to identify the wound area and severity level when making care decision. We propose an algorithm for estimating the wound area and severity level of skin tears using a deep learning method. In this study, U-Net was used to estimate the skin tear area and VGG16 was used to estimate the severity level. The deep learning method shows an Intersection of Union (IoU) of 0.58 and 0.65 in estimating wound areas and purpura areas, and 62.2% accuracy in estimating severity levels. The proposed method outperforms the previous method using a classical machine learning method. This indicates that the proposed deep learning method is promising for image processing for skin tears, even if the skin tears include narrow wound edges and flaps, which are difficult to distinguish from the wound area.Clinical relevance-The proposed method can automatically estimate the area and severity level of skin tears to assist caregivers who are unfamiliar with skin tears.

Creation of the Forearm 3D-Model with Veins from Transversal Ultrasonography Image Sequence.

This study developed an automatic detection algorithm of vessel and skin regions in a transversal ultrasonography image on the arm. We also developed an algorithm to generate a 3D model from detected areas to assist vein puncture. In the algorithm, the vessel's candidate regions in the ultrasonography image were detected using U-Net or Mask R-CNN, which are a kind of deep learning method for segmentation. Then vessel regions were selected among the candidates based on continuous properties in an image sequence. The skin regions were also detected. The 3D polygon data was created from paired pixels in sequential images. The experiments demonstrated that Mask R-CNN could correctly estimate the branch of vessel which were difficult to identify accurate region separately using U-Net, and achieved an overall IoU of 80%. The confirmation experiment of 3D model demonstrated that generated model have enough feasibility for assessment of appropriate veins and locations for puncture.Clinical relevance-The developed 3D model generation from ultrasonography images will be useful for support to identify the appropriate veins for puncture.

Comparing Bone Fusion Rates Between Novel Unidirectional Porous Tricalcium Beta-Phosphate and Autologous Bone in Lumbar Lateral Interbody Fusion: A Two-Year Radiographic Outcome Study.

This retrospective cohort study aims to examine the potential differences in bone fusion between autologous bone and artificial bone in the lumbar lateral interbody fusion at 2two years post-surgery. The bone fusions performed in 15 cases and at 34 intervertebral levels were compared to assess the differences between the artificial bone, Affinos® (Kuraray Co., Tokyo, Japan), and autogenous bone. Two years post-surgery, we evaluated computed tomography (CT) multi-planar reconstruction images in the coronal and sagittal planes. One year after surgery, out of the 24 windows, 17 (70.8%) windows transplanted with autologous bones showed bone fusion. Additionally, out of the 38 windows, 18 (47.4%) windows transplanted with Affinos® showed bone fusion. Two years post-surgery, out of the 24 windows, 19 (79.2%) windows transplanted with autologous bones showed bone fusion. Additionally, out of the 38 windows, 30 (79.0%) windows transplanted with Affinos® showed bone fusion, and no difference was observed in the fusion rate at two years post-surgery (P = 0.238). In cases using Affinos® for transplanted bone, the bone fusion rate increased between one and two years. The rate of bony fusion using Affinos® in lateral lumbar interbody fusion (LLIF) cages is at par with that of autologous bone grafts at two years post-surgery. Affinos® is a promising candidate for graft material in LLIF surgery.

Reconstruction with the right gastroepiploic vein during pancreaticoduodenectomy and total pancreatectomy to prevent left-sided portal hypertension: a report of two cases.

BACKGROUND: Left-sided portal hypertension including gastric venous congestion may be caused by ligating the splenic vein during pancreaticoduodenectomy with portal vein resection or total pancreatectomy. The usefulness of reconstruction with the splenic vein has been reported in such cases. However, depending on the site of the tumor and other factors, it may be impossible to leave sufficient length of the splenic vein, making anastomosis difficult. We report two patterns of reconstruction with the right gastroepiploic vein during pancreaticoduodenectomy and total pancreatectomy to prevent left-sided portal hypertension. CASE PRESENTATION: The first patient was a 79-year-old man who underwent pancreaticoduodenectomy for pancreatic cancer. The root of the splenic vein was infiltrated by the tumor, and we resected this vein at the confluence of the portal vein. Closure of the portal vein was performed without reconstruction of the splenic vein. To prevent left-sided portal hypertension, we anastomosed the right gastroepiploic vein to the middle colic vein. Postoperatively, there was no suggestion of left-sided portal hypertension, such as splenomegaly, varices, and thrombocytosis. The second case was a 63-year-old woman who underwent total pancreatectomy for pancreatic cancer. The splenic vein-superior mesenteric vein confluence was infiltrated by the tumor, and we resected the portal vein, including the confluence. End-to-end anastomosis was performed without reconstruction of the splenic vein. We also divided the left gastric vein, left gastroepiploic vein, right gastroepiploic vein, and right gastric vein, which resulted in a lack of drainage veins from the stomach and severe gastric vein congestion. We anastomosed the right gastroepiploic vein to the left renal vein, which improved the gastric vein congestion. Postoperatively, imaging confirmed short-term patency of the anastomosis site. Although the patient died because of tumor progression 8 months after the surgery, no findings suggested left-sided portal hypertension, such as varices. Reconstruction with the right gastroepiploic vein during pancreaticoduodenectomy and total pancreatectomy is useful to prevent left-sided portal hypertension.

Effect of platelet-rich plasma on the acceleration of graft bone catabolism in lateral lumbar interbody fusion in a short-term assessment.

This study aimed to demonstrate whether impregnating the graft bone with platelet-rich plasma (PRP) accelerates graft bone catabolism in lateral lumbar interbody fusion (LLIF). Consecutive patients who underwent LLIF were assessed. Of the two spaces for bone grafts in the intervertebral cage, one space was filled with graft bone impregnated with PRP, and the other was filled with graft bone without PRP, which divided the graft bones into PRP and non-PRP groups. The mean Hounsfield units (HU) of the graft bone at the center of the cage space in the coronal and axial slices were measured using computed tomography (CT) images 1 week and 6 months after surgery. The delta value of HU from 1 week to 6 months after surgery was calculated for the PRP and non-PRP groups. We compared the delta values of the HU between the two groups. The PRP and non-PRP groups comprised 16 bone grafts. In the coronal slices, the HU value in the PRP group (delta value: 526.1 ± 352.2) tended to have a greater decrease at 6 months after surgery compared with that in the non-PRP group (delta value: 217.6 ± 240.4) (p = 0.065). In the axial slices, the HU value in the PRP group (delta value: 501.3 ± 319.6) was significantly decreased at 6 months after surgery compared with that in the non-PRP group (delta value: 159.2 ± 215.3) (p = 0.028). Impregnating the graft-bone with PRP accelerated graft bone catabolism in LLIF within 6 months after surgery.

A lesson from polybutylene succinate plastisphere to the discovery of novel plastic degrading enzyme genes in marine vibrios.

Polybutylene succinate (PBS) is an eco-friendly green plastic. However, PBS was shown as being non-biodegradable in marine environments, and up until now, only a limited number of PBS-degrading marine microbes have been discovered. We first set up in vitro PBS- and PBSA (polybutylene succinate adipate)-plastispheres to characterize novel PBS-degrading marine microbes. Microbial growth and oxygen consumption were observed in both PBS- and PBSA-plastispheres enriched with natural seawater collected from Usujiri, Hokkaido, Japan, and Vibrionaceae and Pseudoalteromonadaceae were significantly enriched on these films. Further gene identification indicated that vibrios belonging to the Gazogenes clade possess genes related to a PBS degrading enzyme (PBSase). The PBS degradation assay for six Gazogenes clade vibrios identified Vibrio ruber, Vibrio rhizosphaerae, and Vibrio spartinae as being capable of degrading PBS. We further identified the gene responsible for PBSase from the type strain of V. ruber, and the purified recombinant vibrio PBSase was found to have low-temperature adaptation and was active under high NaCl concentrations. We also provided docking models between the vibrio PBSase and PBS and PBSA units to show how vibrio PBSase interacts with each substrate compared to the Acidovorax PBSase. These results could contribute to a more sustainable society through further utilization of PBS in marine environments and plastic recycling.

Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients.

PURPOSE: This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications. METHODS: This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods. RESULTS: Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%). CONCLUSIONS: From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Size-mismatched transplantation from large donors to small recipients is associated with pancreas graft thrombosis: A retrospective national observational study.

INTRODUCTION: Donor-recipient (D/R) size mismatch has been evaluated for a number of organs but not for pancreas transplantation. METHODS: We retrospectively evaluated 438 patients who had undergone pancreas transplantation. The D/R body surface area (BSA) ratio was calculated, and the relationship between the ratio and graft prognosis was evaluated. We divided the patients into two groups and evaluated graft survival. The incidence of pancreas graft thrombosis resulting in graft failure within 14 days and 1-year graft survival were compared using Kaplan-Meier curves, and the prognostic factors associated with graft thrombosis were identified by univariate and multivariate analyses. RESULTS: The mean/median donor and recipient BSAs were 1.63 m2 /1.65 m2 , and 1.57 m2 /1.55 m2 , respectively; the mean and median D/R BSAs were both 1.05. The receiver operating characteristic curve cutoff for the D/R BSA ratio was 1.09, and significant differences were identified between patients with ratios of ≥1.09 (high group) versus <1.09 (low group). The incidence of graft thrombosis resulting in pancreas graft failure within 14 days was significantly higher in the high group than in the low group (p < .01). One-year overall and death-censored pancreas graft survival were significantly higher in the low group than in the high group (p < .01). Multivariate analysis identified recipient height, donor BSA, and donor hemoglobin A1c as significant independent factors for graft thrombosis. Cubic spline curve analysis indicated an increased risk of graft thrombosis with increasing D/R BSA ratio. CONCLUSION: D/R size mismatch is associated with graft thrombosis after pancreas transplantation.

Phase-Separated Giant Liposomes for Stable Elevation of α-Hemolysin Concentration in Lipid Membranes.

Staphylococcus aureus α-hemolysin (αHL) is one of the most popular proteins in nanopore experiments within lipid membranes. Higher concentrations of αHL within the lipid membrane are desirable to enhance the mass transport capacity through nanopores. However, the reconstitution of αHL at high concentrations is associated with the problem of membrane lytic disruption. In this study, we present a method that effectively increases αHL concentration while maintaining membrane stability. This method is achieved by using phase-separated giant liposomes, where coexisting liquid-disordered (Ld) and liquid-ordered phases (Lo) are enriched in unsaturated lipids and saturated lipids with cholesterol (Chol), respectively. Fluorescence observation of αHL in liposomes revealed that the presence of Chol facilitates αHL insertion into the membrane. Despite the preferential localization of αHL in the Ld phase rather than the Lo phase, the coexistence of both Lo and Ld phases prevents membrane disruption in the presence of concentrated αHL. We have explained this stabilization mechanism considering the lower membrane tension exhibited by phase-separated liposomes compared to homogeneous liposomes. Under hypertonic conditions, we have successfully increased the local concentration of αHL by invagination of the lipid-only region in the Ld phase, leaving αHL behind. This method exhibits potential for the reconstitution of various nanochannels and membrane proteins that prefer the Ld phase over the Lo phase, thus enabling the production of giant liposomes at high concentrations and the replication of the membrane-crowding condition observed in cells.

Estimation of anisotropic bending rigidities and spontaneous curvatures of crescent curvature-inducing proteins from tethered-vesicle experimental data.

The Bin/amphiphysin/Rvs (BAR) superfamily proteins have a crescent binding domain and bend biomembranes along the domain axis. However, their anisotropic bending rigidities and spontaneous curvatures have not been experimentally determined. Here, we estimated these values from the bound protein densities on tethered vesicles using a mean-field theory of anisotropic bending energy and orientation-dependent excluded volume. The dependence curves of the protein density on the membrane curvature are fitted to the experimental data for the I-BAR and N-BAR domains reported by C. Prévost et al. Nat. Commun., 2015, 6, 8529 and F.-C. Tsai et al. Soft Matter, 2021, 17, 4254-4265, respectively. For the I-BAR domain, all three density curves of different chemical potentials exhibit excellent fits with a single parameter set of anisotropic bending energy. When the classical isotropic bending energy is used instead, one of the curves can be fitted well, but the others exhibit large deviations. In contrast, for the N-BAR domain, two curves are not well fitted simultaneously the anisotropic model, although it is significantly improved compared to the isotropic model. This deviation likely suggests a cluster formation of the N-BAR domains.

Development and characterization of a latex turbidimetric immunoassay using rabbit anti-CRP single-chain Fv antibodies.

In this study, we developed and demonstrated a latex turbidimetric immunoassay (LTIA) using latex beads immobilized with rabbit monoclonal single-chain variable fragments (scFvs) selected from an scFv-displayed phage library. Sixty-five different anti-c-reactive protein (anti-CRP) scFv clones were identified after biopanning selection using antigen-coupled multi-lamellar vesicles. By ranking antigen-binding clones using the apparent dissociation rate constant (appkoff) as a sorting index, scFv clones with a dissociation constant (KD free) ranging from 4.07 × 10-9 M to 1.21 × 10-11 M were isolated. Among them, three candidates (R2-6, R2-45, and R3-2) were produced in the culture supernatant at concentrations of 50 mg/L or higher in flask culture and maintained at considerably high antigen-binding activity in immobilized state on the CM5 sensor chip surface. All the scFv-immobilized latexes (scFv-Ltxs) prepared were well-dispersed in 50 mM MOPS at pH 7.0, without additives for dispersion, and their antigen-dependent aggregation was sufficiently detectable. The reactivity of scFv-Ltx to antigen differed among the scFv clones, in particular, R2-45 scFv-Ltx detected the CRP with the highest signal. Furthermore, the reactivity of scFv-Ltx varied significantly with salt concentration, scFv immobilization density, and the type of blocking protein. Particularly, antigen-dependent latex aggregation improved significantly in all rabbit scFv clones when scFv-Ltx was blocked with horse muscle myoglobin compared with conventional bovine serum albumin; while their baseline signals in the absence of antigen were fully stable. Under optimal conditions, R2-45 scFv-Ltx exhibited greater aggregation signals with antigen concentrations higher than those produced by conventional polyclonal antibody-immobilized latex for CRP detection in LTIA. The methodology for rabbit scFv isolation, immobilization, and antigen-dependent latex aggregation demonstrated in the present study can be applicable to scFv-based LTIA for various target antigens.

Utilization of the Pancreas From Donors With an Extremely High Pancreas Donor Risk Index: Report of the National Registry of Pancreas Transplantation.

Pancreas transplants from expanded criteria donors are performed widely in Japan because there is a shortage of brain-dead donors. However, the effectiveness of this strategy is unknown. We retrospectively studied 371 pancreas transplants to evaluate the possibility of pancreas transplantation from expanded criteria donors by the Pancreas Donor Risk Index (PDRI). Patients were divided into five groups according to quintiles of PDRI values (Q1-Q5). The 1-year pancreas graft survival rates were 94.5% for Q1, 91.9% for Q2, 90.5% for Q3, 89.3% for Q4, and 79.6% for Q5, and were significantly lower with a lower PDRI (p = 0.04). A multivariate analysis showed that the PDRI, donor hemoglobin A1c values, and pancreas transplantation alone significantly predicted 1-year pancreas graft survival (all p < 0.05). Spline curve analysis showed that the PDRI was incrementally associated with an increased risk of 1-year graft failure. In the group with a PDRI ≥ 2.87, 8/56 patients had graft failures within 1 month, and all were due to graft thrombosis. The PDRI is a prognostic factor related to the 1-year graft survival rate. However, pancreas transplantation from high-PDRI donors shows acceptable results and could be an alternative when the donor pool is insufficient.

Safety and Osteointegration of Titanium Screws Coated with a Fibroblast Growth Factor-2-Calcium Phosphate Composite Layer in Non-Human Primates: A Pilot Study.

Spinal instrumentation surgery for older patients with osteoporosis is increasing. Implant loosening may occur due to inappropriate fixation in osteoporotic bone. Developing implants that achieve stable surgical results, even in osteoporotic bone, can reduce re-operation, lower medical costs, and maintain the physical status of older patients. Fibroblast growth factor-2 (FGF-2) promotes bone formation; thus, coating pedicle screws with an FGF-2-calcium phosphate (FGF-CP) composite layer is hypothesized to enhance osteointegration in spinal implants. We designed a long-term implantation pilot study that estimated the safety and bone-forming efficacy of pedicle screws coated with an FGF-CP composite layer in cynomolgus monkeys. Titanium alloy screws, either uncoated (controls) or aseptically coated with an FGF-CP composite layer, were implanted in the vertebral bodies of six female adult cynomolgus monkeys (three monkeys per group) for 85 days. Physiological, histological, and radiographic investigations were performed. There were no serious adverse events, and no radiolucent areas were observed around the screws in either group. The bone apposition rate in the intraosseous region was significantly higher in the FGF-CP group than in the controls. Moreover, as analyzed by Weibull plots, the bone formation rate of the FGF-CP group exhibited a significantly higher regression line slope than the control group. These results demonstrated that there was significantly less risk of impaired osteointegration in the FGF-CP group. Our pilot study suggests that FGF-CP-coated implants could promote osteointegration, be safe, and reduce the probability of screw loosening.

Disappearance, division, and route change of excitable reaction-diffusion waves in deformable membranes.

Shapes of biomembrane in living cells are regulated by curvature-inducing proteins. However, the effects of membrane deformation on signal transductions such as chemical waves have not been researched adequately. Here, we report that membrane deformation can alter the propagation of excitable reaction-diffusion waves using state-of-the-art simulations. Reaction waves can induce large shape transformations, such as membrane budding and necking, that erase or divide the wave, depending on the curvature generated by the waves, feedback to the wave propagation, and the ratio of the reaction and deformation times. In genus-2 vesicles, wave division occurs at branching points and collided waves disappear together. We demonstrate that the occasional disappearance of the waves can alter the pathway of wave propagation. Our findings suggest that membrane deformation and reaction waves can together regulate signal transductions on biomembranes.