Development and Evaluation of a Treadmill-based Video-see-through and Optical-see-through Mixed Reality Systems for Obstacle Negotiation Training.

Mixed reality (MR) technologies have a high potential to enhance obstacle negotiation training beyond the capabilities of existing physical systems. Despite such potential, the feasibility of using MR for obstacle negotiation on typical training treadmill systems and its effects on obstacle negotiation performance remains largely unknown. This research bridges this gap by developing an MR obstacle negotiation training system deployed on a treadmill, and implementing two MR systems with a video see-through (VST) and an optical see-through (OST) Head Mounted Displays (HMDs). We investigated the obstacle negotiation performance with virtual and real obstacles. The main outcomes show that the VST MR system significantly changed the parameters of the leading foot in cases of Box obstacle (approximately 22 cm to 30 cm for stepping over 7cm-box), which we believe was mainly attributed to the latency difference between the HMDs. In the condition of OST MR HMD, users tended to not lift their trailing foot for virtual obstacles (approximately 30 cm to 25 cm for stepping over 7cm-box). Our findings indicate that the low-latency visual contact with the world and the user's body is a critical factor for visuo-motor integration to elicit obstacle negotiation.

Piton: Investigating the Controllability of a Wearable Telexistence Robot.

The COVID-19 pandemic impacted collaborative activities, travel, and physical contact, increasing the demand for real-time interactions with remote environments. However, the existing remote communication solutions provide limited interactions and do not convey a high sense of presence within a remote environment. Therefore, we propose a snake-shaped wearable telexistence robot, called Piton, that can be remotely used for a variety of collaborative applications. To the best of our knowledge, Piton is the first snake-shaped wearable telexistence robot. We explain the implementation of Piton, its control architecture, and discuss how Piton can be deployed in a variety of contexts. We implemented three control methods to control Piton: HM-using a head-mounted display (HMD), HH-using an HMD and hand-held tracker, and FM-using an HMD and a foot-mounted tracker. We conducted a user study to investigate the applicability of the proposed control methods for telexistence, focusing on body ownership (Alpha IVBO), mental and physical load (NASA-TLX), motion sickness (VRSQ), and a questionnaire to measure user impressions. The results show that both the HM and HH provide relevantly high levels of body ownership, had high perceived accuracy, and were highly favored, whereas the FM control method yielded the lowest body ownership effect and was least favored. We discuss the results and highlight the advantages and shortcomings of the control methods with respect to various potential application contexts. Based on our design and evaluation of Piton, we extracted a number of insights and future research directions to deepen our investigation and realization of wearable telexistence robots.

Synthesis and preclinical evaluation of [11C]MTP38 as a novel PET ligand for phosphodiesterase 7 in the brain.

PURPOSE: Phosphodiesterase (PDE) 7 is a potential therapeutic target for neurological and inflammatory diseases, although in vivo visualization of PDE7 has not been successful. In this study, we aimed to develop [11C]MTP38 as a novel positron emission tomography (PET) ligand for PDE7. METHODS: [11C]MTP38 was radiosynthesized by 11C-cyanation of a bromo precursor with [11C]HCN. PET scans of rat and rhesus monkey brains and in vitro autoradiography of brain sections derived from these species were conducted with [11C]MTP38. In monkeys, dynamic PET data were analyzed with an arterial input function to calculate the total distribution volume (VT). The non-displaceable binding potential (BPND) in the striatum was also determined by a reference tissue model with cerebellar reference. Finally, striatal occupancy of PDE7 by an inhibitor was calculated in monkeys according to changes in BPND. RESULTS: [11C]MTP38 was synthesized with radiochemical purity ≥99.4% and molar activity of 38.6 ± 12.6 GBq/µmol. Autoradiography revealed high radioactivity in the striatum and its reduction by non-radiolabeled ligands, in contrast with unaltered autoradiographic signals in other regions. In vivo PET after radioligand injection to rats and monkeys demonstrated that radioactivity was rapidly distributed to the brain and intensely accumulated in the striatum relative to the cerebellum. Correspondingly, estimated VT values in the monkey striatum and cerebellum were 3.59 and 2.69 mL/cm3, respectively. The cerebellar VT value was unchanged by pretreatment with unlabeled MTP38. Striatal BPND was reduced in a dose-dependent manner after pretreatment with MTP-X, a PDE7 inhibitor. Relationships between PDE7 occupancy by MTP-X and plasma MTP-X concentration could be described by Hill's sigmoidal function. CONCLUSION: We have provided the first successful preclinical demonstration of in vivo PDE7 imaging with a specific PET radioligand. [11C]MTP38 is a feasible radioligand for evaluating PDE7 in the brain and is currently being applied to a first-in-human PET study.

Pyrazolo[4,3-d]pyrimidine Derivatives as a Novel Hypoxia-Inducible Factor Prolyl Hydroxylase Domain Inhibitor for the Treatment of Anemia.

Inhibition of hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) promotes erythropoietin (EPO) production by stabilizing the HIFα subunit. Thieno[2,3-d]pyrimidine 8 identified based on X-ray crystal structure analysis was optimized to lead to the discovery of pyrazolo[4,3-d]pyrimidine 13 as the lead compound of orally bioavailable HIF-PHD inhibitors. Conversion of the benzyl moiety in 13 gave pyrazolopyrimidine 19 with high solubility and bioavailability, which increased hemoglobin levels in anemic model rats after repeated oral administration. It was shown that pyrazolo[4,3-d]pyrimidine derivatives are promising therapeutic agents for renal anemia through the inhibition of HIF-PHD.

Venous architecture of the glabellar to the forehead region.

The precise venous anatomy of the glabellar to the forehead region remains unknown. This study aimed to detail the venous architecture of the glabellar region to the forehead in conjunction with that of the supratrochlear artery to reduce the risk of venous congestion of flaps in this area. Fifteen fresh human cadavers were examined here. In five specimens, contrast medium was injected only into the venous system; in 10 specimens, two different types of contrast media were injected into the arterial and venous systems, respectively. A total of 30 hemifacial specimens were radiographed stereoscopically and observed microscopically. In all the cadavers, a distinct vein (termed as the "transverse nasal root vein") connected the bilateral angular veins. One or two large ascending veins branched from the transverse nasal root or angular vein, coursing toward the forehead skin. Numerous small veins branched out from the large ascending vein(s), forming a subdermal polygonal venous network. Small ascending veins arose from this network and coursed toward the dermis, draining venous flow from the dermis. Three different-sized valves prevented the reflux of blood in the venous pathway. The large ascending vein(s) and supratrochlear artery ran parallel only in the medial canthal area. Tiny venous vasa vasorum surrounded the adventitia of the supratrochlear artery and anastomosed with the polygonal venous network, while a few small veins from the vasa vasorum ascended toward the dermis. Understanding the venous architecture of this region is expected to facilitate the safe elevation of various flaps in the area.

New technique for releasing tension to prevent widening of an abdominal scar.

We developed an easy way to release tension from an abdominal cutaneous suture by plicating the anterior rectus sheath for several centimetres. We used this in two patients and the scars were satisfactory. Plication of the fascia is an easy and effective way of releasing the tension of a cutaneous sutured line.

Anthropometric evaluation of bilateral cleft lip nose with cone beam computed tomography in early childhood: Estimation of nasal tip collapse.

BACKGROUND: Nasal tip features of cleft lip nose cannot be defined well using conventional measurement methods. Therefore, we developed a new method in which vertical nasal tip (the pronasale) position is evaluated based on the Frankfurt-Horizontal plane. This measurement was applied to bilateral cleft lip patients in early childhood. METHODS: Cone beam computed tomography (CT) records of bilateral cleft lip patients after primary rhinoplasty aged from 5 to 8 years (n = 13) were investigated retrospectively. As age-matched controls, data from a normal group (n = 17) and complete unilateral cleft lip group after primary rhinoplasty (n = 19) were included. In each group, nasolabial angle (ß), nasal tip angle (α), nasal width (al-al), columellar length (sn-c' ), nasal tip protrusion (sn-prn), and vertical nasal tip position (sn'-prn'/sn'-n') were investigated. RESULTS: With the exception of vertical nasal tip position and nasal width, the measurement data of the bilateral cleft lip patients were acceptable. In the bilateral cleft lip group, however, vertical nasal tip position was significantly higher and nasal width was significantly larger than those in the normal and unilateral groups (P < 0.0001 and P = 0.0298; P = 0.0001 and P = 0.0002, respectively). CONCLUSIONS: In cleft lip nose, the lower lateral cartilage that normally composes the nasal tip domes is splayed out, causing cephalic positioning of the pronasale. Nasal tip collapse was more severe in bilateral cleft lip than in the unilateral group. These results were compatible with the fact that many bilateral cleft lip patients require augmentation rhinoplasty after adolescence even after primary rhinoplasty.

Palatoplasty for bilateral oblique cleft of the soft palate accompanied by Tessier number 5·7 cleft.

Craniofacial cleft is a rare congenital deformity in which there are fissures of a facial structure classified by Tessier. A palatoplasty to reconstruct the muscle sling and to close the cleft of the velum was performed. Acceptable postoperative appearance of the velum was seen after 6 months. Although further follow-up is still needed for velopharyngeal function, this case report provides details of the anatomical deformities and our surgical approach to this atypical bilateral cleft palate.

A rare case of proboscis lateralis with median cleft lip.

A very rare case of proboscis lateralis is reported. This case is different from previously reported cases due to proboscis lateralis, single nostril, loss of columella, and median cleft lip without holoprosencephaly. In addition, this is considered the first surviving individual with proboscis lateralis accompanied by median cleft lip.

Management of craniofacial hyperostosis in Proteus syndrome.

Proteus syndrome is a rare congenital hamartomatous condition that is characterized by a wide range of malformations, occasionally involving the head and the face. Skin and skeletal developmental malformations are common and may be manifested in significant physical anomalies. In this report, we describe the cases of 2 patients affected by this condition. For one patient, a recurrence occurred 4 years after the elimination of cranial hyperostosis. In the second patient, although we observed macrosomia and peculiar countenance in the context of craniofacial hyperostosis, the patient did not visit a clinic for approximately 50 years before seeking treatment. The management of the craniofacial involvement is described, and a literature overview is presented.

Distribution of adipose-derived stem cells in adipose tissues from human cadavers.

BACKGROUND: Adipose-derived stem cells (ASCs) possess multipotency in vivo and in vitro, and thus are thought to be very promising precursors for use in regenerative medicine. ASCs can be concentrated from adipose tissue by enzymatic digestion and transplanted to increase angiogenesis or for cosmesis. ASC transplants are now being performed in a clinical setting. Although data on ASCs are extensive, the distribution of ASCs in human fat tissue has not been fully clarified. Thus, it is important to identify the distribution of ASCs to obtain cell populations rich in ASCs for clinical use. METHODS: ASCs express CD34, a cell surface marker. As CD34 is also expressed by endothelial cells, we immunohistochemically stained 2-µm-thick serial paraffin sections of fat tissue obtained from various parts of formalin-fixed cadavers with anti-CD31 and anti-CD34 antibodies to distinguish ASCs from endothelial cells. RESULTS: CD34(+)/CD31(-) cells were mainly found in connective tissue tracts and perivascularly. Among fat tissues obtained from various sites, fat tissues in the thoracic back and lower abdomen were richest in CD34(+)/CD31(-) cells. CONCLUSION: The concentrations of CD34(+)/CD31(-) cells in adipose tissues differ between sites. The sites most highly enriched for ASCs were identified, and it is now possible to select the best sites for collection of ASCs for transplantation.

How to revise and utilise the cephalogram for craniofacial dysostosis--modification of the porion and the McNamara line.

McNamara line analysis is often utilised in orthognathic surgery and is particularly useful in that it can easily express the extent of maxillo-mandibular deformity quantitatively. However, in craniofacial dysostosis (CFD), the location of the porion (PR) is sometimes displaced inferiorly. The McNamara line depends on the Frankfurt horizontal plane (FH plane), and hence, its deviation is often extremely distorted in CFD. The objective of this study was to enable more correct reflection of deformities of CFD patients on lateral cephalogram analysis. The lateral cephalograms of 152 Asian individuals were involved. angle basion(BA).orbitale(Or).PR, angle BA. nasion(NA).PR, and the distance from BA to PR on the BA-NA plane were measured and each standard range was established. Using these ranges, modified PR (mPR) is supposed to lie within a fairly small area. Second, we utilised mPR in the practice of McNamara line analysis in CFD patients. In both cases in the present study, it was confirmed that modified McNamara line analysis can express the deformities more precisely than conventinal analysis, as far as the maxillo-mandibular relationship is concerned. However, particularly in Case 2, both the cranio-maxillary and cranio-mandibular relationships were not entirely consistent with the lateral profile appearance even on modified McNamara line analysis.

What happens between pure hydraulic and buckling mechanisms of blowout fractures?

OBJECTIVE: The present study aims to evaluate how the ratio of the hydraulic and buckling mechanisms affects blowout fracture patterns, when these two mechanisms work simultaneously. MATERIALS AND METHODS: Three-dimensional computer-aided-design (CAD)models were generated simulating ten skulls. To simulate impact, 1.2J was applied on the orbital region of these models in four patterns. Pattern 1: All the energy works to cause the hydraulic effect. Pattern 2: Two-thirds of the energy works to cause the hydraulic effect; one-third of the energy works to cause the buckling effect. Pattern 3: One-third of the energy works to cause the hydraulic effect; two-thirds of the energy works to cause the buckling effect. Pattern 4: The entire energy quantum works to cause the buckling effect. Using the finite element method, the regions where fractures were theoretically expected to occur were calculated and were compared between the four patterns. RESULTS: More fracture damage occurred for Pattern 1 than Pattern 2, and for Pattern 3 than for Pattern 4. CONCLUSION: The hydraulic and buckling mechanisms interact with one another. When these two mechanisms are combined, the orbital walls tend to develop serious fractures.

Reconstruction of vulva using pudendal thigh gluteal fold bilobed flap.

In reconstructing a large defect of the vulva, we combined the gluteal fold and the pudendal thigh flaps and made a bilobed flap. Using this gluteal fold pudendal thigh bilobed flap, we reconstructed a vagina with sufficient depth and width. The surrounding skin defect was simultaneously reconstructed. Sensation was intact in all areas of the reconstruction. In addition, the sutured lines of both donor sites are hidden in the gluteal and inguinal folds. Thus, the gluteal fold pudendal thigh bilobed flap seems to be ideal for reconstructing large vulvar defects.

A novel approach to thoracic wall reconstruction based on a muscle perforator.

When reconstructing the thoracic wall, non-adaptation of the suture line is a critical concern, especially when artificial implants are used. Therefore, a reliable and safe flap is required. Based on an anatomical study of cadavers, we decided to dissect the pectoralis major musculo-cutaneous flap into two parts, on the surface and beneath the muscle fascia, while preserving the muscle perforators. We designated the skin portion as the V-Y advancement flap or rotation V-Y advancement flap and the muscle flap as the transposition flap. Both flaps had different suture lines. We applied this method to two patients requiring reconstruction of anterior thoracic defects with artificial implants. One patient did not have adverse effects, and the flaps took well. The shape of the breast did not change significantly. However, the other patient was a heavy smoker. Although the V-Y advancement flap took well, the cutaneous triangular tip made at the time of tumour resection became necrotic. However, the underlying pectoralis major muscles successfully covered the implants and did not show any signs of infection. In conclusion, reconstruction of the anterior thoracic wall to change the suture line with a V-Y advancement flap, based on the muscle perforator and pectoralis major muscle flap, is a useful and reliable method, especially when an artificial implant is used.

Anal and perianal reconstruction after extramammary Paget's disease using a posterior thigh flap with a thin square wing.

Extramammary Paget's disease regularly requires a wide resection of skin, often including the anal tract. When reconstructing the anal tract, simulating natural anatomy by creating the thinnest possible flap is essential to prevent incontinence. We reconstructed the anal and perianal area using a posterior thigh trilobed flap. The lobe to be transposed to the anal duct had a square design and was thinned. The other lobes were used to cover perianal defects and the flap donor site. Using this method, we reconstructed three patients who required large perianal area and anal tract resections. All flaps took well, and after the initial healing process, the patients did not develop lasting incontinence. We conclude that the posterior thigh flap with a thin square wing is useful for reconstruction of the anal tract and perianal area.

Treatment of giant congenital melanocytic nevi with enzymatically separated epidermal sheet grafting.

Treatment of giant congenital melanocytic nevi (GCMNs) must be considered from both a cosmetic and a medical aspect of reducing the risk of a growing malignancy. We treated five patients who had a GCMN on the trunk with an enzymatically separated epidermal sheet taken from their excised GCMN skin. All patients underwent enzymatically separated epidermal sheet grafting at the age of 2 months. With the patient under general anaesthesia, we removed the affected area with an electric dermatome until the brown colour had almost completely disappeared. The removed skin was immersed in dispase I solution (1000Uml(-1)) dissolved in Ringer's solution at 37 degrees C for 75-105min until the epidermal sheet separated from the dermis without tension. Three back lesions and two abdominal lesions were treated. In all cases, the enzymatically separated epidermis grafted well, without infection. The amount of discharge that accumulated from immediately after the operation until the first dressing change (performed at 3 days after the operation) was reduced compared with that from curettage. The skin colour was light brown at first and gradually became lighter within a few months. The grafted areas were soft and did not show significant re-pigmentation. In most cases, hard hair did not grow on the treated area. Histological samples taken 1 year after the operation showed that the dermal layer was reconstituted without pigmented nevus cells. Enzymatically separated epidermal grafting is a useful method for the treatment of GCMN, is easy to perform and leaves cosmetically satisfactory results.