D1-Tyr246 and D2-Tyr244 in photosystem II: Insights into bicarbonate binding and electron transfer from QA•- to QB.

In photosystem II (PSII), D1-Tyr246 and D2-Tyr244 are symmetrically located at the binding site of the bicarbonate ligand of the non-heme Fe complex. Here, we investigated the role of the symmetrically arranged tyrosine pair, D1-Tyr246 and D2-Tyr244, in the function of PSII, by generating four chloroplast mutants of PSII from Chlamydomonas reinhardtii: D1-Y246F, D1-Y246T, D2-Y244F, and D2-Y244T. The mutants exhibited altered photoautotrophic growth, reduced PSII protein accumulation, and impaired O2-evolving activity. Flash-induced fluorescence yield decay kinetics indicated a significant slowdown in electron transfer from QA•- to QB in all mutants. Bicarbonate reconstitution resulted in enhanced O2-evolving activity, suggesting destabilization of bicarbonate binding in the mutants. Structural analyses based on a quantum mechanical/molecular mechanical approach identified the existence of a water channel that leads to incorporation of bulk water molecules and destabilization of the bicarbonate binding site. The water intake channels, crucial for bicarbonate stability, exhibited distinct paths in the mutants. These findings shed light on the essential role of the tyrosine pair in maintaining bicarbonate stability and facilitating efficient electron transfer in native PSII.

Dynamic Cervical Spinal Canal Stenosis: Identifying Imaging Risk Factors in Extended Positions.

STUDY DESIGN: A retrospective study at a single academic institution. PURPOSE: This study aimed to identify imaging risk factors for stenosis in extended neck positions undetectable in preoperative neutral magnetic resonance imaging (MRI) and improving decompression strategies for cervical spine disorders. OVERVIEW OF LITERATURE: Cervical disorders are influenced by various dynamic factors, with spinal stenosis appearing during neck extension. Despite the diagnostic value of dynamic cervical MRI, standard practice often uses neutral-position MRI, potentially influencing surgical outcomes. METHODS: This study analyzed 143 patients who underwent decompression surgery between 2012 and 2014, who had symptomatic cervical disorders and MRI evidence of spinal cord or nerve compression but had no history of cervical spine surgery. Patient demographics, disease type, Japanese Orthopedic Association score, and follow-up periods were recorded. Spinal surgeons conducted radiological evaluations to determine stenosis levels using computed tomography myelography or MRI in neutral and extended positions. Measurements such as dural tube and spinal cord diameters, cervical alignment, range of motion, and various angles and distances were also analyzed. The residual space available for the spinal cord (SAC) was also calculated. RESULTS: During extension, new stenosis frequently appeared caudal to the stenosis site in a neutral position, particularly at C5/C6 and C6/C7. A low SAC was identified as a significant risk factor for the development of new stenosis in both the upper and lower adjacent disc levels. Each 1-mm decrease in SAC resulted in an 8.9- and 2.7-fold increased risk of new stenosis development in the upper and lower adjacent disc levels, respectively. A practical SAC cutoff of 1.0 mm was established as the threshold for new stenosis development. CONCLUSIONS: The study identified SAC narrowing as the primary risk factor for new stenosis, with a clinically relevant cutoff of 1 mm. This study highlights the importance of local factors in stenosis development, advocating for further research to improve outcomes in patient with cervical spine disorders.

Asenapine versus olanzapine for the treatment of nausea and vomiting in patients with cancer: A retrospective study.

AIM: Patients with cancer often experience nausea and vomiting (N/V), but may have difficulty using olanzapine (OLZ), a common antiemetic. Asenapine (ASE) is a multi-acting receptor-targeted antipsychotic like OLZ, although there is little evidence that ASE serves as an antiemetic. The aim of this study was to evaluate the efficacy and tolerability of ASE compared to those of OLZ for the treatment of N/V in patients with cancer. METHODS: This retrospective study involved patients who received 5 mg ASE, 5 mg OLZ, or 2.5 mg OLZ for 2 days. Daily worst N/V was rated on a scale of 0 (none) to 3 (very much). The primary endpoint was the proportion of patients who had a response, defined as any reduction in N/V score. A complete response (CR) was defined as a score reduction to 0. Secondary endpoints included the proportion of patients with CR and adverse events. RESULTS: Between April 2017 and March 2023, 212 patients were enrolled to receive treatment: 5 mg ASE (n = 34), 5 mg OLZ (n = 102), or 2.5 mg OLZ (n = 76). No significant differences in response rates (52.9% vs. 58.8% vs. 52.6%, p = 0.671) or secondary endpoints were observed between the groups. Patients receiving ASE were more likely to experience oral hypoesthesia (p = 0.004). CONCLUSION: This preliminary study suggests that ASE may be effective for N/V. Further studies are required to confirm these findings.

Prenatal diagnosis of bone dysplasias.

Bone dysplasias are individually rare but collectively common. The prenatal diagnosis of bone dysplasias, especially perinatally lethal dysplasias, is of major interest to obstetric services. The current nosology of genetic skeletal disorders addresses over 400 disorders. However, in clinical practice, we encounter only a limited number of disorders, such as FGFR3-related dysplasias, osteogenesis imperfecta, and type II collagenopathies. The recent development of non-invasive prenatal genetic testing using cell-free fetal DNA in maternal blood samples has had a major impact on the prenatal diagnosis of genetic diseases. However, imaging examinations remain critical for the final diagnosis of bone dysplasias because molecular testing only shows genetic variants, and not their pathogenicity - most variants are clinically insignificant. Bone dysplasias are typically suspected when limb shortening is identified by screening ultrasound. Further assessment can be followed by more detailed ultrasound, magnetic resonance imaging (MRI), and CT. Based on these data, rational decision-making is feasible, even when the definitive prenatal diagnosis is not feasible. Here, we highlight key images of common bone dysplasias obtained by currently available modalities.

Evaluation of ABCG2-mediated extra-renal urate excretion in hemodialysis patients.

Two-thirds of urate is excreted via the renal pathway and the remaining one-third via the extra-renal pathway, the latter mainly via the intestine in healthy individuals. ABCG2, a urate exporter, is expressed in various tissues including the kidney and intestine, and its dysfunction leads to hyperuricemia and gout. ABCG2 is regarded as being responsible for most of the extra-renal urate excretion. However, the extra-renal urate excretion capacity via ABCG2 remains undefined in end-stage kidney diseases. Therefore, we evaluated the capacity of extra-renal ABCG2 using 123 anuric hemodialysis patients whose urate excretion depended on only the extra-renal pathway. ABCG2 function in each participant was estimated based on ABCG2 dysfunctional variants. We computed the uric acid pool (PoolUA) from bodyweight and serum urate level (SUA) using previously reported radio-isotopic data, and we analyzed the association between ABCG2 function and the PoolUA. SUA and PoolUA increased significantly with ABCG2 dysfunction, and extra-renal ABCG2 could excrete up to approximately 60% of the daily uric acid turnover in hemodialysis patients. Our findings indicate that the extra-renal urate excretion capacity can expand with renal function decline and highlight that the extra-renal pathway is particularly important in the uric acid homeostasis for patients with renal dysfunction.

Two specific domains of the γ subunit of chloroplast FoF1 provide redox regulation of the ATP synthesis through conformational changes.

Chloroplast FoF1-ATP synthase (CFoCF1) converts proton motive force into chemical energy during photosynthesis. Although many studies have been done to elucidate the catalytic reaction and its regulatory mechanisms, biochemical analyses using the CFoCF1 complex have been limited because of various technical barriers, such as the difficulty in generating mutants and a low purification efficiency from spinach chloroplasts. By taking advantage of the powerful genetics available in the unicellular green alga Chlamydomonas reinhardtii, we analyzed the ATP synthesis reaction and its regulation in CFoCF1. The domains in the γ subunit involved in the redox regulation of CFoCF1 were mutated based on the reported structure. An in vivo analysis of strains harboring these mutations revealed the structural determinants of the redox response during the light/dark transitions. In addition, we established a half day purification method for the entire CFoCF1 complex from C. reinhardtii and subsequently examined ATP synthesis activity by the acid-base transition method. We found that truncation of the ß-hairpin domain resulted in a loss of redox regulation of ATP synthesis (i.e., constitutively active state) despite retaining redox-sensitive Cys residues. In contrast, truncation of the redox loop domain containing the Cys residues resulted in a marked decrease in the activity. Based on this mutation analysis, we propose a model of redox regulation of the ATP synthesis reaction by the cooperative function of the ß-hairpin and the redox loop domains specific to CFoCF1.

Algal PETC-Pro171-Leu suppresses electron transfer in cytochrome b6f under acidic lumenal conditions.

Linear photosynthetic electron flow (LEF) produces NADPH and generates a proton electrochemical potential gradient across the thylakoid membrane to synthesize ATP, both of which are required for CO2 fixation. As cellular demand for ATP and NADPH varies, cyclic electron flow (CEF) between Photosystem I and the cytochrome b6f complex (b6f) produces extra ATP. b6f regulates LEF and CEF via photosynthetic control, which is a pH-dependent b6f slowdown of plastoquinol oxidation at the lumenal site. This protection mechanism is triggered at more alkaline lumen pH in the pgr1 (proton gradient regulation 1) mutant of the vascular plant Arabidopsis (Arabidopsis thaliana), which contains a Pro194Leu substitution in the b6f Rieske Iron-sulfur protein Photosynthetic Electron Transfer C (PETC) subunit. In this work, we introduced the equivalent pgr1 mutation in the green alga Chlamydomonas reinhardtii to generate PETC-P171L. Consistent with the pgr1 phenotype, PETC-P171L displayed impaired NPQ induction along with slower photoautotrophic growth under high light conditions. Our data provide evidence that the ΔpH component in PETC-P171L depends on oxygen availability. Only under low oxygen conditions was the ΔpH component sufficient to trigger a phenotype in algal PETC-P171L where the mutant b6f was more restricted to oxidize the plastoquinol pool and showed diminished electron flow through the b6f complex. These results demonstrate that photosynthetic control of different stringency are established in C. reinhardtii depending on the cellular metabolism, and the lumen pH-sensitive PETC-P171L was generated to read out various associated effects.

Temporary Monosegmental Fixation Using Multiaxial Percutaneous Pedicle Screws for Surgical Management of Bony Flexion-Distraction Injuries of the Thoracolumbar Spine: A Technical Note.

Introduction: The efficacy of minimally invasive surgeries for thoracolumbar flexion-distraction injuries (FDIs) has been reported, but those surgeries were monosegmental fusion surgeries of two adjacent vertebrae with bone grafts or temporary fixations using percutaneous pedicle screws (PPSs) that were at least bisegmental. Our idea was to fuse the fracture itself, not to fuse the fractured vertebra with an adjacent vertebra or to stabilize the fractured vertebra by bridging rostrally/caudally adjacent intact vertebrae, specifically when the displacement is minimal. This study aimed to present the surgical techniques of reduction and temporary monosegmental fixation of neurologically intact thoracolumbar bony FDIs using multiaxial PPSs, which can minimize the surgical invasiveness and preserve all motion segments, as well as report three cases treated with this procedure. Technical Note: When the fracture extended from the vertebral body to the spinous process at the same level, screws were placed into the fractured vertebra rostrally to the fracture along the rostral endplate, and the caudally adjacent vertebra was instrumented beyond the fracture line. When the fracture extended from the vertebral body to the spinous process of the rostrally adjacent vertebra, screws were placed into the fractured vertebra caudally to the fracture line, and the rostrally adjacent vertebra was instrumented. The kyphotic deformity was reduced through ligamentotaxis by using MPPSs in the rostral vertebra as rigid joysticks to apply direct buttress leverage to the rostral endplate. Intraoperative blood loss was minimal. The correction of kyphotic deformity and its durability were acceptable, and the segmental range of motion of the two affected vertebrae from flexion to extension was maintained after implant removal. Conclusions: This surgery can act as the least-invasive option for the management of thoracolumbar bony FDIs to allow early ambulation without external bracing and to preserve all the motion segments.

Traction Radiculopathy After Surgery for Lumbar Spinal Metastasis: A Case Report.

Treatment of spinal metastasis has attracted much attention globally, especially in Japan, with the advancement of cancer therapy. Among the metastases, those from breast and prostate cancers may be more important than others considering the high incidence of bone metastasis and the long-term prognosis. This condition often results in surgical procedures of spinal metastases to improve cancer patients' quality of life (QOL). In the present case, a patient with lumbar metastasis of breast cancer presented with right L5 nerve palsy after palliative laminectomy surgery with posterior fusion. The nerve palsy had improved after additional bone resection around the right L5 root. The mechanism of this postoperative leg paralysis was subclinical nerve root damage due to the narrowing of the intervertebral foramen caused by the tumor protrusion like lumber disc hernia and the stretching of the nerve roots caused by the posterior shift of the dural tube. When performing decompression and fixation of a metastatic spine showing a herniated tumor formed by a tumor protruding posteriorly into the intervertebral foraminal space, sufficient tumor mass debulking should be considered to avoid postoperative intervertebral foraminal stenosis.

Cervical Implant Allergy With Chronic Neck Pain: A Case Report.

A 57-year-old woman underwent cervical implant surgery for a dislocated cervical spine fracture, and she complained of continuous intractable neck pain after surgery. Eight years later, she developed a plantar skin rash, subsequently diagnosed as a metal allergy, and metal dentures were replaced with ceramic ones. The skin rash, however, persisted for four more years after that and was eventually treated with cervical implant removal. Subsequently, her skin rash and her neck pain improved simultaneously. This synchronous improvement strongly suggested that the neck pain could have been caused by a cervical implant allergy. We discuss a case of posterior cervical implant allergy that presented with neck pain and plantar skin rash years after surgery.

Effectiveness of preventive B-Lynch sutures in patients at a high risk of postpartum hemorrhage.

AIM: We aimed to evaluate the clinical outcomes and adverse events of preventive B-Lynch suture performed during cesarean section in patients at a high risk of postpartum hemorrhage. METHODS: This retrospective observational study included patients who underwent a cesarean section and the B-Lynch suture at a tertiary perinatal medical center between January 2019 and May 2021. The B-Lynch sutures were placed preventively before excessive blood loss occurred in patients with uterine atony, placental position abnormality (placenta previa and low-lying placenta), placenta accreta, thrombocytopenia, coagulopathy, and other risk factors of bleeding. Partial compression sutures for bleeding points and vaginal gauze packing were placed if required. RESULTS: The B-Lynch suture was performed in 38 patients, and hysterectomy was avoided in all patients. Only one patient required intrauterine balloon tamponade as an additional treatment 5 days after the cesarean section. No apparent postoperative bleeding occurred within 2 h after the cesarean section in 35 patients (92%), and blood transfusion was avoided in 14 patients (37%). Thirty-three adverse events occurred in 23 patients; these included an inflammatory response, hematomas, retained products of conception, and ileus in one, two, and two patients, respectively. In most cases, the events were not severe and were unrelated to the procedure. In one patient, a second-look operation was performed and no complications were observed in the uterus and abdominal cavity. CONCLUSIONS: Preventive B-Lynch suture seemed effective and safe after a short-term observation. When excessive bleeding is expected during a cesarean section, an early introduction of this procedure is recommended.

Comparison of surgical outcomes of posterior surgeries between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To compare the surgical outcomes and complications of posterior decompression between individuals with cervical spondylotic myelopathy (CSM) and those with ossification of the posterior longitudinal ligament (OPLL). SETTING: Seventeen medical institutions in Japan. METHODS: This study included 814 individuals with CSM (n = 636) and OPLL (n = 178) who underwent posterior decompression. Propensity score matching of the baseline characteristics was performed to compare surgical outcomes and perioperative complications between the CSM and OPLL groups. RESULTS: Before propensity score matching, the OPLL group had higher percentage of male individuals, body mass index, and number of stenosis levels and longer duration of symptoms (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively). After matching, the baseline characteristics were comparable between the CSM (n = 98) and OPLL (n = 98) groups. The postoperative Japanese Orthopaedic Association (JOA) scores, preoperative-to-postoperative changes in the JOA scores, and JOA score recovery rates were not significantly different between the groups (P = 0.42, P = 0.47, and P = 0.09, respectively). The postoperative visual analog scale (VAS) score for neck pain and preoperative-to-postoperative changes in the VAS score for neck pain were not significantly different between the groups (P = 0.25 and P = 0.50, respectively). The incidence of perioperative complications was comparable between groups. CONCLUSION: Neurological improvement and complication rates after surgery were comparable between individuals with CSM and those with OPLL, suggesting similar effectiveness and safety of posterior decompression for both conditions.

Augmented Reality Device for Preoperative Marking of Spine Surgery Can Improve the Accuracy of Level Identification.

Introduction: Wrong-site spine surgery is an incident that could result in possible severe complications. In this present spinal surgery, the accurate spinal level is confirmed via preoperative or intraoperative radiographic marking. However, the location of radiographic marking has been determined from the manual palpation on the landmarks of the body surface. As a result, severe spine deformity can make it hard to identify the spinal level by manual palpation, thus leading to misidentification of the spinal level.Recently, the use of mixed reality in spine surgery is gradually increasing. In this study, we will demonstrate a head-mounted display (HMD) device that can project a hologram (3D image) of the patient's bone onto the actual patient's body to improve the accuracy of level identification for spine surgery. Technical Note: 3D CT images are created preoperatively, and the bone's STL data (3D data) are generated with the workstation. The created STL data are downloaded to the augmented reality software Holoeyes, installed on the HMD. Through this device, surgeons can view the hologram (3D image) of a patient's bone overlaying on an actual patient's body.We temporally estimated the spinous process level only by manual palpation without an HMD. Then, we estimated the spinous process level again after matching this hologram to a real bone with an HMD. The accuracy of the level identification with an HMD and without an HMD was examined by radiographic marking in order to evaluate the misidentification rate of the level. Without an HMD, the misidentification rate of the level was at 26.5%, while with it, the rate was reduced to 14.3%. Conclusions: On preoperative marking, an HMD-projecting bone image onto a patient's body could allow us to estimate the spinal level more accurately. Identification of the spinal level using mixed reality is effective in preventing wrong-site spine surgery.

Adjacent Segment Stenosis after Muscle-Preserving Selective Laminectomy: A Retrospective Study of Patients with a Minimum 10-Year Follow-Up.

Introduction: The present study aimed to understand the characteristics of adjacent segment stenosis post-surgery by examining the status of adjacent segment stenosis in patients with long-term follow-up after muscle-preserving selective laminectomy (SL). Methods: We examined 43 patients who underwent muscle-preserving SL at a single academic institution and were followed up for >10 years. The C2-C7 angle, C2-C7 sagittal vertical axis, range of motion, and C7 slope were measured using an X-ray lateral view. The anterior-posterior diameter of the spinal cord (AP of SC) and anterior-posterior diameter of the dural tube (AP of dura) at adjacent segment were measured using magnetic resonance imaging T2-weighted sagittal section. Residual space for the spinal cord at the adjacent segment (SAC) was calculated as the difference between AP of SC and AP of dura. Results: Four cases had cephalad adjacent segment stenosis at the last follow-up (upper stenosis (US) group), 9 cases had caudal adjacent segment stenosis ( lower stenosis (LS) group), and 30 cases had no stenosis (none (N) group). AP of SC, AP of dura, and SAC at the upper adjacent segment were significantly lower in the US group. AP of dura and SAC at the lower adjacent segment were significantly lower in the LS group. Multivariate logistic regression analysis revealed that the small AP of dura in the upper adjacent segment and small SAC in the lower adjacent segment were risk factors for developing a new stenosis. Conclusions: Decompression should be considered beforehand in adjacent segments with small AP of SC and small AP of dura when performing cervical decompression.

Atlantoaxial stenosis after muscle-preserving selective laminectomy.

There are few reports of degenerative atlantoaxial stenosis and new stenosis after cervical decompression. We experienced four cases of atlantoaxial stenosis after muscle-preserving selective laminectomy. We compared these four cases with no stenosis cases after long-term follow-up of selective laminectomy, as well as healthy subjects. A total of 1205 patients who underwent muscle-preserving selective laminectomy due to cervical disorders were included in this study. Postoperative atlantoaxial stenosis, which needed decompression, appeared in 4 cases, and 30 patients did not have radiological stenosis for more than 10 years after surgery. Twenty healthy volunteers were also used as controls. The radiographic parameters measured were C2-C7 angle, C2-C7 sagittal vertical axis (SVA), C2 slope, C7 slope, C2-C5 angle, C5-C7 angle, C1-C2 angle, and atlantodental interval (ADI). We measured the anterior-posterior (AP) diameters of the spinal cord (SC) and dural tube (Dura) at C1/C2 with sagittal MRI. In the cases of atlantoaxial stenosis, the AP of SC and Dura at C1/C2 were smaller preoperatively, and the residual space for SC (SAC) was also smaller. The preoperative ADI was significantly higher in patients with atlantoaxial stenosis, suggesting preoperative instability at C1/C2. Analysis of the ROC curve showed that patients with a preoperative SAC of less than 3.6 mm and an ADI of more than 1.35 mm were more likely to develop postoperative atlantoaxial stenosis. When we perform a muscle-preserving selective laminectomy, decompression of C1/C2 is suggested when the SAC at C1/C2 is less than 3.6 mm and the ADI is more than 1.35 mm.

A Novel Technique of Mixed Reality Systems in the Treatment of Spinal Cord Tumors.

Several reports have compared spinal cord tumor removal techniques but none have clearly described the appropriate site and level of indication for laminectomy or laminoplasty. The approach method for tumor removal depends on the type and localization of the tumor and the surgeon's skill. Therefore, a system that can suggest various surgical techniques is useful for spinal cord tumor surgery. The mixed reality system introduced in this paper is an excellent system that can suggest various surgical procedures. Using this system for spinal cord tumor removal, we made the surgery less invasive; therefore, we introduced this system and demonstrated its usefulness. Stereoscopic data of the patients with spinal cord tumors were obtained from preoperative myelogram-CT data. Stereoscopic laminectomy models including tumors were created using Blender, a free three-dimensional (3D) image editing software. We observed these data as 3D object images using a head-mounted display (HMD). This HMD is commercially available and relatively inexpensive. The surgical procedure is determined by considering those 3D images, radiological diagnosis, and the skill of surgeons. Intraoperative confirmation of the laminectomy site could be performed using the HMD. The 3D visualization of pathological conditions resulted in correct preoperative surgical planning and less invasive surgery in all five cases. Stereoscopic images using HMDs allow us a more intuitive understanding of the positional relationship between the tumor and spinal structure. These 3D object images can bring us more accurate preoperative planning and proper determination of surgical methods.

Clinical Effects of Anterior Cervical Spondylolisthesis on Cervical Spondylotic Myelopathy After Posterior Decompression Surgery: A Retrospective Multicenter Study of 732 Cases.

STUDY DESIGN: Multicenter retrospective study. OBJECTIVES: We aim to investigate features of cervical spondylotic myelopathy (CSM) associated with anterior cervical spondylolisthesis (ACS) during posterior decompression surgery. METHODS: A total of 732 patients with CSM were enrolled, who underwent posterior decompression surgery between July 2011 and November 2015 at 17 institutions. The patients with ACS (group A), defined as an anterior slippage of ≥2 mm on plain radiographs, were compared with those without ACS (group non-A). Also, the characteristics of patients with ACS progression (group P), defined as postoperative worsening of ACS ≥2 mm or newly developed ACS, were investigated. Moreover, kyphosis was defined as C2-C7 angle in neutral position ≤-5°. The Japanese Orthopedic Association (JOA) scoring system was used for clinical evaluation. RESULTS: Group A consisting of 62 patients (8.5%) had worse preoperative clinical status but comparable surgical outcomes to group non-A. Furthermore, ACS was associated with greater age, and the degree of slippage did not affect myelopathy grades. Seventeen patients (2.3%) were observed in group P, and preoperative ACS was a significant predisposing factor for the progression without clinical impact. Among the patients in group A, preoperative cervical kyphosis was a risk factor for lower JOA recovery rate. CONCLUSIONS: Although the presence of ACS increases the risk of postoperative progression, it is not a contraindication for posterior decompression. However, surgeons need to consider the indication of fusion surgery for the patients who have ACS accompanied by kyphosis because of the poor surgical outcomes.

A Case of Undifferentiated Carcinoma in a 2-Month Postpartum Reproductive Tract with a Rapid and Fulminant Course.

Advanced carcinoma of the lower female reproductive tract is rare during pregnancy and the postpartum period. We here present a case of a 32-year-old Japanese woman, whose entire lower reproductive tract had been invaded by carcinomas as of 2 months after childbirth. She had been infertile, and pregnancy had been established by repeated embryo transfer. The gynecological cancer screening, which included Pap smear tests, was negative during the periods she underwent infertility treatment or during the first trimester. At 26 gestational weeks, the patient noticed uterine contractions concomitant with genital bleeding. Labor progressed slowly and steadily; thus, the pregnancy was ended by cesarean section at 29 weeks. At 2 months after childbirth, the patient experienced increased left abdominal pain and underwent a pelvic examination, revealing multiple pelvic masses and diffuse vaginal tumors causing stenosis. Vaginal tumors were biopsied, and histochemical analysis showed undifferentiated carcinoma with possible adenocarcinoma. Imaging modalities including CT, MRI, and PET-CT suggest that the carcinoma had invaded the entire reproductive tract, especially the uterine body, metastasized into the lungs and the ischial bones, and disseminated onto the peritoneum. She received multiple rounds of chemotherapy but died 6 months after childbirth. Taking into consideration the clinical feature and immunohistochemical profiles of the cancer cells, the endometrium is the most likely origin.

The Utility of Augmented Reality in Spinal Decompression Surgery Using CT/MRI Fusion Image.

In spine surgery, instrumentation surgery using augmented reality (AR) and navigation systems have become widespread, while decompression surgery using those applications is not so common. However, we sometimes encounter intraoperative problems such as excessive blood loss or bony resection in decompression surgery. Therefore, a practical navigation system is needed for safer spinal decompression surgery. Furthermore, the cost of AR and navigation systems has been expensive. In this study, we report the utility of applying the AR system of the head-mounted display (HMD) at a lower cost to identify the osteotomy area of laminectomy for spinal decompression surgery. 3D CT/MRI fusion images are created preoperatively to generate 3D data consisting of the nerve elements, a dural tube and nerve roots, and the bony elements of the spine. Then, we made the 3D data of the bone after decompression by 3D editing free software. Uploading the created 3D data of both 3D CT/MRI fusion and preoperative planned laminectomy images to the AR software in the HMD, we could confirm the proper decompression area with the 3D images projected through the HMD. This system was useful for cervical and lumbar decompression for confirming the proper decompression area preoperatively. We could perform decompression surgery just designed with this system. This system is a preoperative planning system that allows 3D HMD visualization to keep track of surgical orientation. It does not allow preoperative verification so far. However, this system has various possible applications and is considered a promising system for the future.