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Abstract This study aimed to elucidate mid- to long-term radiological and respiratory outcomes in patients aged 7–11 years at index surgery with Marfan syndrome and early-onset scoliosis (EOS) in a retrospective multicenter study. Primary outcomes were final thoracic height and final percentage of predicted vital capacity (%VC) at or after 16 years of age. We identified 21 (6 male and 15 female) patients with a mean age of 9.9 years and mean follow-up period of 149.3 months. Fifteen patients underwent primary fusion, whereas six underwent growth-friendly surgery (GFS). The mean preoperative and final T1–T12 heights were 204.0 mm and 248.0 mm, respectively. Final pulmonary function tests were available for 16 patients, and the mean final %VC was 54.0% with 10 patients exhibiting a final %VC

Companion animals, such as felines and canines, could provide an excellent platform for translational research from veterinary to human medicine. However, the use of feline induced pluripotent stems (fiPSCs) of quality in basic or clinical research has not been reported. Here, we generated footprint-free fiPSCs derived from embryonic cells, as well as juvenile feline uterus-derived cells using Sendai virus vector harboring six feline-specific pluripotency-associated genes. The fiPSCs were confirmed to be of high quality with the potential to form teratomas including all three germ layers. Furthermore, our fiPSCs were maintained under feeder-free and chemically-defined conditions using StemFit® AK02N and recombinant laminin 511, iMatrix-511. Further research on fiPSCs could result in their widespread application in veterinary regenerative medicine, which could pave the way for their use in advanced regenerative medicine research for humans.

Introduction: The Scoliosis Research Society-30 (SRS-30) is a questionnaire originally developed from the SRS-22r questionnaire and is used to evaluate adolescent idiopathic scoliosis (AIS). It comprised questions on five domains: function, pain, self-image, mental health, and satisfaction, with seven additional questions related to postoperative aspects. In addition to the original English version, translations in multiple languages have been effectively applied. Herein, we evaluated the internal consistency and external validity of the Japanese version of the SRS-30 for AIS patients. Methods: Among the 30 questions in SRS-30, the eight additional questions from SRS-22r were translated and back-translated to create a Japanese version of the SRS-30. This translated questionnaire was then used to survey patients with AIS who underwent corrective fusion surgery one year postoperatively. The internal consistency of the responses was evaluated using the Cronbach α coefficient. Additionally, the Spearman correlation analyses were conducted to assess the correlation between the scores obtained from the SRS-30 Japanese version and SRS-22r and the Oswestry Disability Index (ODI) for the overall scale and the five domains. Results: A total of 81 cases (eight males and 73 females; mean age at surgery 14.4 years) were enrolled. The mean preoperative Cobb angle was 51.0°. The Cronbach α coefficient for the overall SRS-30 was 0.861, indicating high internal consistency, while the coefficients for each domain were as follows: function/activity, 0.697; pain, 0.405; self-image/appearance, 0.776; mental health, 0.845; and satisfaction, 0.559. The SRS-30 total score significantly correlated with the SRS-22r total (r=0.945, P

Abstract Background Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs). Methods We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery. Results The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference. Conclusions We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

Introduction: In this study, we aim to estimate the natural standing sagittal alignment in patients with adult spinal deformity (ASD), firstly by investigating the normative values of anatomical pelvic parameters based on the anterior pelvic plane (APP) in a healthy population, and to clarify the relationships between the anatomical and positional pelvic parameters in standing position. Methods: The images of biplanar slot-scanning full-body stereoradiography in 140 healthy Japanese volunteers (mean age, 39.5 years; 59.3% female) were examined. In addition to three-dimensional measurements including pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT), the APP angle (APPA; anterior tilting=positive) was measured as the angle between the APP and the vertical line using the two-dimensional lateral image. Anatomical SS and PT (aSS and aPT) were calculated as the angles of SS and PT in reference to APP. Results: The mean (range) values of APPA, aSS, and aPT were determined to be 0.7° (−16.8°/15.5°), 36.8° (18.3°/64.9°), and 13.2° (−0.6°/28.7°), respectively. Moreover, SS was found to be significantly correlated with PI and aSS, while PT was significantly correlated with PI, aSS, aPT, and body weight. Also, PT was significantly larger in females than in males. Multiple linear regression analysis deduced the following equations: SS=0.404×aSS+0.203×PI+12.463, PT=−0.391×aSS+0.774×PI+1.950×sex (male=0, female=1)−12.971, wherein aSS had the greatest effect for predicting SS among the included factors and PI had the greatest effect for predicting PT. In addition, no significant differences were noted between PT/PI and aPT/PI. Conclusions: As per the results of this study, significant correlations were noted among parameters and predicting models for positional parameters (SS and PT) using anatomical parameters (aSS and aPT) in a healthy population. This novel measurement concept based on the APP has been considered to be useful in estimating natural SS and PT in standing position using the anatomical pelvic parameters in patients with ASD.

Carbapenems are antimicrobial agents commonly used to treat extended-spectrum β-lactamase (ESBL)-producing bacteria. Although cefmetazole (CMZ) is considered effective for ESBL-producing Escherichia coli (ESBL-EC) bacteremia, previous studies showed its limitations, including the influence of the initial antimicrobial agent. Here, we examined the effects of different approaches to antimicrobial therapy with CMZ and meropenem (MEPM) on the time to defervescence in ESBL-EC bacteremia. Notably, the influence of previous antimicrobial agents was excluded. Inpatients with ESBL-EC detected in blood cultures between April 2018 and March 2023 were included and assigned to CMZ (n = 14), MEPM (n = 8), de-escalation to CMZ (dCMZ; n = 9), or escalation to MEPM (eMEPM; n = 11) groups. The median time to defervescence was 3.5, 1.0, 2.0, and 4.0 days in the CMZ, MEPM, dCMZ, and eMEPM groups, respectively, with no significant differences. Cox proportional hazards analysis showed a significant difference in the hazard ratio (95% confidence interval) of 0.378 (0.145–0.984) for the time to defervescence with CMZ versus MEPM (p = 0.046). The extent of a delayed time to defervescence is greater with early CMZ administration than with MEPM administration in patients with non-severe ESBL-EC bacteremia.

Introduction: Gait disturbance due to compressive cervical myelopathy has been previously described. However, data on how gait disturbance varies with the degree of lower extremity motor impairment are limited. Therefore, we investigated the characteristics of gait analysis based on severity and determined how gait disturbance progresses in compressive cervical myelopathy. Methods: We enrolled 44 patients (32 men and 12 women; mean age, 65.0 years) out of 108 consecutive patients with compressive cervical myelopathy who underwent spinal cord decompression surgery in our hospital. The exclusion criteria were inability to gait and complications affecting gait. Twenty-two patients with Japanese Orthopaedic Association scores 1 or 2 for lower extremity motor functions were assigned to the severe group, and 22 patients who scored 3 or 4 were assigned to the moderate group. Gait analysis was performed preoperatively using a long thin-type sensor sheet, and 25 healthy volunteers were assigned to the control group. Results: Stride length, swing phase, and gait speed decreased whereas step angle, stance phase, and double support duration increased as myelopathy progressed. Step width was significantly larger in the severe group than in the moderate and control groups. The cutoff values based on severe myelopathy with the inability to ascend or descend stairs without support were 60% for the stride length percentage of body height and 100 cm/s for gait speed. Conclusions: Decreases in stride length, swing phase, and gait speed and increases in step angle, stance phase, and double support duration are compensatory changes as cervical myelopathy progresses. Step width is a compensatory change that is not significantly altered in moderate myelopathy but increases when gait becomes affected, such that the patient cannot ascend or descend stairs without support.

Abstract Alport syndrome (AS) is a hereditary glomerulonephritis caused by COL4A3, COL4A4 or COL4A5 gene mutations and characterized by abnormalities of glomerular basement membranes (GBMs). Due to a lack of curative treatments, the condition proceeds to end-stage renal disease even in adolescents. Hampering drug discovery is the absence of effective in vitro methods for testing the restoration of normal GBMs. Here, we aimed to develop kidney organoid models from AS patient iPSCs for this purpose. We established iPSC-derived collagen α5(IV)-expressing kidney organoids and confirmed that kidney organoids from COL4A5 mutation-corrected iPSCs restore collagen α5(IV) protein expression. Importantly, our model recapitulates the differences in collagen composition between iPSC-derived kidney organoids from mild and severe AS cases. Furthermore, we demonstrate that a chemical chaperone, 4-phenyl butyric acid, has the potential to correct GBM abnormalities in kidney organoids showing mild AS phenotypes. This iPSC-derived kidney organoid model will contribute to drug discovery for AS.

Abstract While classic views proposed that working memory (WM) is mediated by sustained firing, recent evidence suggests a contribution of activity-silent states. Within WM, human neuroimaging studies suggest a switch between attentional foreground and background, with only the foregrounded item represented in active neural firing. To address this process at the cellular level, we recorded prefrontal (PFC) and posterior parietal (PPC) neurons in a complex problem-solving task, with monkeys searching for one or two target locations in a first cycle of trials, and retaining them for memory-guided revisits on subsequent cycles. When target locations were discovered, neither frontal nor parietal neurons showed sustained goal-location codes continuing into subsequent trials and cycles. Instead there were sequences of timely goal silencing and reactivation, and following reactivation, sustained states until behavioral response. With two target locations, goal representations in both regions showed evidence of transitions between foreground and background, but the PFC representation was more complete, extending beyond the current trial to include both past and future selections. In the absence of unbroken sustained codes, different neuronal states interact to support maintenance and retrieval of WM representations across successive trials.

Abstract Background Adult spinal deformity has a substantially debilitating effect on older people’s physical and mental health. However, the impact of sagittal malalignment on locomotive syndrome (LS), sarcopenia, and physical function in community-dwelling older women has not yet been clarified. This study aimed to investigate the association between these factors in community-dwelling middle aged and older women. Methods A total of 361 women were recruited from participants performing aquatic exercises in a rural area of Japan. The body mass index, skeletal muscle mass index, trunk muscle mass, spinal inclination angle (SIA), grip strength, timed up-and-go test (TUG), maximum stride of the participants, and one-leg standing time were measured. Low back pain (LBP)- and health-related quality of life (HRQOL) were evaluated using the Oswestry Disability Index (ODI) and the Short-Form 8 questionnaire. Associations between the global sagittal alignment using SIA and investigating parameters were analyzed. Results The prevalence of sarcopenia was 3.6%. The prevalence of LS (stages 1, 2, and 3) was 43.8% (158 of 361), and the number of participants in each LS stage was 203 (stage 0), 95 (stage 1), 28 (stage 2), and 35 (stage 3). The SIA was significantly correlated with the 25-question geriatric locomotive function scale (r′ = 0.292, p

Functional magnetic resonance imaging (fMRI) in behaving monkeys has a strong potential to bridge the gap between human neuroimaging and primate neurophysiology. In monkey fMRI, to restrain head movements, researchers usually surgically implant a plastic head-post on the skull. Although time-proven to be effective, this technique could create burdens for animals, including a risk of infection and discomfort. Furthermore, the presence of extraneous objects on the skull, such as bone screws and dental cement, adversely affects signals near the cortical surface. These side effects are undesirable in terms of both the practical aspect of efficient data collection and the spirit of “refinement” from the 3R's. Here, we demonstrate that a completely non-invasive fMRI scan in awake monkeys is possible by using a plastic head mask made to fit the skull of individual animals. In all of the three monkeys tested, longitudinal, quantitative assessment of head movements showed that the plastic mask has effectively suppressed head movements, and we were able to obtain reliable retinotopic BOLD signals in a standard retinotopic mapping task. The present, easy-to-make plastic mask has a strong potential to simplify fMRI experiments in awake monkeys, while giving data that is as good as or even better quality than that obtained with the conventional head-post method.

Background: The choice of operative method for lumbar spinal stenosis with Meyerding grade I degenerative spondylolisthesis remains controversial. The purpose of this study was to identify the preoperative factors affecting the 2-year postoperative patient-reported outcome in Meyerding grade I degenerative spondylolisthesis. Methods: Seventy-two consecutive patients who had minimally invasive decompression alone (D group; 28) or with fusion (DF group; 44) were enrolled. The parameters investigated were the Japanese Orthopaedic Association back pain evaluation questionnaire as patient-reported assessment, and L4 slippage (L4S), lumbar lordosis (LL), and lumbar axis sacral distance (LASD) as an index of sagittal alignment for radiological evaluation. Data collected prospectively at 2 years postoperatively were examined by statistical analysis. Results: Sixty-two cases (D group; 25, DF group; 37) were finally evaluated. In multiple logistic regression analysis, preoperative L4S and LASD were extracted as significant preoperative factors affecting the 2-year postoperative outcome. Patients with preoperative L4S of 6 mm or more have a lower rate of improvement in lumbar spine dysfunction due to low back pain (risk ratio=0.188, p=.043). Patients with a preoperative LASD of 30 mm or more have a higher rate of improvement in lumbar dysfunction due to low back pain (risk ratio=11.48, p=.021). The results of multiple logistic analysis by operative method showed that there was a higher rate of improvement in lumbar spine dysfunction due to low back pain in patients with preoperative LASD of 30 mm or more in DF group (risk ratio=172.028, p=.01). Conclusions: Preoperative L4S and LASD were extracted as significant preoperative factors affecting patient-reported outcomes at 2 years postoperatively. Multiple logistic analyses by the operative method suggested that DF may be advantageous in improving lumbar dysfunction due to low back pain in patients with preoperative LASD of 30 mm or more.

Abstract Histiocytic sarcoma (HS) is an incurable aggressive tumor, and no consensus has been made on the treatment due to its rare occurrence. Since dogs spontaneously develop the disease and several cell lines are available, they have been advocated as translational animal models. In the present study, therefore, we explored gene mutations and aberrant molecular pathways in canine HS by next generation sequencing to identify molecular targets for treatment. Whole exome sequencing and RNA-sequencing revealed gene mutations related to receptor tyrosine kinase pathways and activation of ERK1/2, PI3K-AKT, and STAT3 pathways. Analysis by quantitative PCR and immunohistochemistry revealed that fibroblast growth factor receptor 1 (FGFR1) is over-expressed. Moreover, activation of ERK and Akt signaling were confirmed in all HS cell lines, and FGFR1 inhibitors showed dose-dependent growth inhibitory effects in two of the twelve canine HS cell lines. The findings obtained in the present study indicated that ERK and Akt signaling were activated in canine HS and drugs targeting FGFR1 might be effective in part of the cases. The present study provides translational evidence that leads to establishment of novel therapeutic strategies targeting ERK and Akt signaling in HS patients.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is an intractable disease leading to severe neurological deficits. Its etiology and pathogenesis are primarily unknown. The relationship between OPLL and comorbidities, especially type 2 diabetes (T2D) and high body mass index (BMI), has been the focus of attention; however, no trait has been proven to have a causal relationship. We conducted a meta-analysis of genome-wide association studies (GWASs) using 22,016 Japanese individuals and identified 14 significant loci, 8 of which were previously unreported. We then conducted a gene-based association analysis and a transcriptome-wide Mendelian randomization approach and identified three candidate genes for each. Partitioning heritability enrichment analyses observed significant enrichment of the polygenic signals in the active enhancers of the connective/bone cell group, especially H3K27ac in chondrogenic differentiation cells, as well as the immune/hematopoietic cell group. Single-cell RNA sequencing of Achilles tendon cells from a mouse Achilles tendon ossification model confirmed the expression of genes in GWAS and post-GWAS analyses in mesenchymal and immune cells. Genetic correlations with 96 complex traits showed positive correlations with T2D and BMI and a negative correlation with cerebral aneurysm. Mendelian randomization analysis demonstrated a significant causal effect of increased BMI and high bone mineral density on OPLL. We evaluated the clinical images in detail and classified OPLL into cervical, thoracic, and the other types. GWAS subanalyses identified subtype-specific signals. A polygenic risk score for BMI demonstrated that the effect of BMI was particularly strong in thoracic OPLL. Our study provides genetic insight into the etiology and pathogenesis of OPLL and is expected to serve as a basis for future treatment development.

IntroductionAdolescent idiopathic scoliosis (AIS) is a disorder with a three-dimensional spinal deformity and is a common disease affecting 1-5% of adolescents. AIS is also known as a complex disease involved in environmental and genetic factors. A relation between AIS and body mass index (BMI) has been epidemiologically and genetically suggested. However, the causal relationship between AIS and BMI remains to be elucidated.Material and methodsMendelian randomization (MR) analysis was performed using summary statistics from genome-wide association studies (GWASs) of AIS (Japanese cohort, 5,327 cases, 73,884 controls; US cohort: 1,468 cases, 20,158 controls) and BMI (Biobank Japan: 173430 individual; meta-analysis of genetic investigation of anthropometric traits and UK Biobank: 806334 individuals; European Children cohort: 39620 individuals; Population Architecture using Genomics and Epidemiology: 49335 individuals). In MR analyses evaluating the effect of BMI on AIS, the association between BMI and AIS summary statistics was evaluated using the inverse-variance weighted (IVW) method, weighted median method, and Egger regression (MR-Egger) methods in Japanese.ResultsSignificant causality of genetically decreased BMI on risk of AIS was estimated: IVW method (Estimate (beta) [SE] = -0.56 [0.16], p = 1.8 × 10-3), weighted median method (beta = -0.56 [0.18], p = 8.5 × 10-3) and MR-Egger method (beta = -1.50 [0.43], p = 4.7 × 10-3), respectively. Consistent results were also observed when using the US AIS summary statistic in three MR methods; however, no significant causality was observed when evaluating the effect of AIS on BMI.ConclusionsOur Mendelian randomization analysis using large studies of AIS and GWAS for BMI summary statistics revealed that genetic variants contributing to low BMI have a causal effect on the onset of AIS. This result was consistent with those of epidemiological studies and would contribute to the early detection of AIS.

It is generally believed that time flows in one direction and that a reversal of time's arrow would render the external world non-sensical. We evaluated our ability to tell the direction of time's arrow in a wide range of dynamic scenes in our daily life by presenting 360 video clips in the correct or incorrect direction. Participants, who judged the direction in a speeded manner, erred in 39% of trials when a video was played in reverse, but in only 9% when it was played normally. Due to the bias favouring the ‘forward’ judgement, the reaction was generally faster for the forward response. However, the reaction became paradoxically faster and more synchronous for the detection of reversal in some critical occasions such as forward motion, free fall, diffusion, division and addition of materials by hand. Another experiment with a fraction of the video clips revealed that reversal replay of these videos provided instantaneous evidence strong enough to overtake the forward judgement bias. We suggest that our brain is equipped with a system that predicts how the external organisms behave or move in these critical occasions and that the prediction error of the system contributes to the fast ‘reversal’ detection.

Abstract Teriparatide (TPTD) administration has a potent osteogenic action and promotes the healing of osteoporotic vertebral fractures (OVFs). We aimed to investigate the outcomes of vertebroplasty with posterior spinal fusion (VP + PSF) and determine the impact of perioperative TPTD administration. We included 73 patients (18 male and 55 female patients; mean age: 78 years) with thoracolumbar OVFs who underwent VP + PSF and were followed-up for at least 2 years. Twenty-three patients who received TPTD perioperatively for > 3 months were included in the TPTD group, and the remaining 50 patients were included in the non-TPTD group. Radiographic findings regarding sagittal alignment and clinical outcomes in both groups were compared. The mean duration of TPTD administration was 17.5 ± 5.0 months (range 4–24 months). The mean loss of correction of local kyphosis angle in the TPTD group (4.0°) was lesser than that in the non-TPTD group (7.5°; p

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among pets owned by coronavirus disease 2019 (COVID-19) patients has been reported around the world. However, how often the animals are exposed to SARS-CoV-2 by their owners is still unclear. We have collected swab samples from COVID-19 patients’ pets and performed real-time RT-PCR to detect the viral genome. In total, 8 of 53 dogs (15.1%) and 5 of 34 cats (14.7%) tested positive for the SARS-CoV-2 N gene. The result of a virus neutralization (VN) test also showed VN antibodies in four cats and six dogs. Our results indicate that the virus often passed from infected owners to their pets, which then excreted the virus despite having no or mild clinical signs.

Abstract Ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. The bridging of ossified lesions to the vertebral body gradually increases, thereby decreasing the mobility of the cervical spine; thus, cervical spine function may decrease over time. However, cervical spine function in patients with cervical OPLL has not been evaluated in large prospective studies. Therefore, we conducted a prospective multicenter study to clarify whether ossification spread can influence cervical spine function and quality of life (QOL) in patients with cervical OPLL. In total, 238 patients (162 men, 76 women; mean age, 63.9 years) were enrolled from 16 institutions. Each patient underwent whole spine computed tomography and was evaluated for cervical spine function and QOL using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). In the multivariate regression analysis, a higher neck VAS score and a larger number of bridge formations of OPLL in the whole spine were significant predictors of adverse outcomes related to cervical spine function. This is the first prospective multicenter study to reveal the impact of ossification spread on cervical spine function. These findings are important to understand the natural course of OPLL and can serve as controls when evaluating postoperative cervical spine function.

Abstract The aim of this study was to analyze the 5-year natural course of frailty status assessed with the Kihon Checklist (KCL) and the risk factors of transition towards frailty in community-dwelling older adults. We used the data from the postal KCL survey conducted by the municipal government between 2011 and 2016. The sample of the current study consisted of 551 older adults (265 men and 286 women) aged 65–70 years in 2011. The median KCL score increased from 2 (interquartile range 1–3) in 2011 to 3 (1–5) in 2016 (p

Abstract DNA methylation plays important functions in gene expression regulation that is involved in individual development and various diseases. DNA methylation has been well studied in human and model organisms, but only limited data exist in companion animals like dog. Using methylation-sensitive restriction enzyme-based next generation sequencing (Canine DREAM), we obtained canine DNA methylation maps of 16 somatic tissues from two dogs. In total, we evaluated 130,861 CpG sites. The majority of CpG sites were either highly methylated (> 70%, 52.5–64.6% of all CpG sites analyzed) or unmethylated (

Abstract Background Patient-reported outcome measures are widely utilized to assess health-related quality of life (HRQOL) in patients with adolescent idiopathic scoliosis (AIS). However, the association between HRQOL and curve severity is mostly unknown. The aim of this study is to clarify the association between HRQOL and curve severity, and to determine the optimal cutoff values of patient-reported outcomes for major curve severity in female patients with AIS. Methods Female patients with AIS treated conservatively were recruited. The patients’ HRQOL outcomes were examined using the revised Scoliosis Research Society-22 (SRS-22r) and the Scoliosis Japanese Questionnaire-27 (SJ-27). The correlations of the SRS-22r and SJ-27 scores with the major Cobb angle were assessed using Spearman’s correlation coefficient analysis. The association between HRQOL issues in the SJ-27 and the major Cobb angle was evaluated by calculating Akaike’s Information Criterion (AIC). Furthermore, the optimal cutoff values of the SRS-22r and SJ-27 scores for the major Cobb angle were determined by AIC analysis. Results The study cohort comprised 306 female patients with AIS. The SRS-22r and SJ-27 scores were significantly correlated with the major Cobb angle. Questions in the SJ-27 regarding discomfort when wearing clothes showed a lower AIC value in patients with severe scoliosis. The optimal cutoff values were a SRS-22r score of 3.2 for the discrimination of severe scoliosis (Cobb angle ≥48°), and a SJ-27 score of 32 for the discrimination of moderate scoliosis (Cobb angle ≥33°). Conclusion Discomfort when wearing clothes was the most important HRQOL problem caused by severe scoliosis. The SRS-22r and SJ-27 scores are useful for the discrimination of clinical status in female patients with severe scoliosis or moderate scoliosis.

Abstract Background Although pelvic incidence (PI) is a key morphologic parameter in assessing spinopelvic sagittal alignment, accurate measurements of PI become difficult in patients with severe hip dislocation or femoral head deformities. This study aimed to investigate the reliability of our novel morphologic parameters and the correlations with established sagittal spinopelvic parameters. Methods One hundred healthy volunteers (25 male and 75 female), with an average age of 38.9 years, were analysed. Whole-body alignment in the standing position was measured using a slot-scanning X-ray imager. We measured the established spinopelvic sagittal parameters and a novel parameter: the sacral incidence to pubis (SIP). The correlation coefficient of each parameter, regression equation of PI using SIP, and regression equation of lumbar lordosis (LL) using PI or SIP were obtained. The intraclass correlation coefficient (ICC) was calculated as an evaluation of the measurement reliability. Results Reliability analysis showed high intra- and inter-rater agreements in all the spinopelvic parameters, with ICCs > 0.9. The SIP and pelvic inclination angle (PIA) demonstrated strong correlation with PI (R = 0.96) and pelvic tilt (PT) (R = 0.92). PI could be predicted according to the regression equation: PI = − 9.92 + 0.905 * SIP (R = 0.9596, p

Abstract Background Vertebroplasty with posterior spinal fusion (VP + PSF) is one of the most widely accepted surgical techniques for treating osteoporotic vertebral collapse (OVC). Nevertheless, the effect of the extent of fusion on surgical outcomes remains to be established. This study aimed to evaluate the surgical outcomes of short- versus long-segment VP + PSF for OVC with neurological impairment in thoracolumbar spine. Methods We retrospectively collected data from 133 patients (median age, 77 years; 42 men and 91 women) from 27 university hospitals and their affiliated hospitals. We divided patients into two groups: a short-segment fusion group (S group) with 2- or 3-segment fusion (87 patients) and a long-segment fusion group (L group) with 4- through 6-segment fusion (46 patients). Surgical invasion, clinical outcomes, local kyphosis angle (LKA), and complications were evaluated. Results No significant differences between the two groups were observed in terms of neurological recovery, pain scale scores, and complications. Surgical time was shorter and blood loss was less in the S group, whereas LKA at the final follow-up and correction loss were superior in the L group. Conclusion Although less invasiveness and validity of pain and neurological relief are secured by short-segment VP + PSF, surgeons should be cautious regarding correction loss.

Introduction: Osteoporotic vertebral fracture (OVF) is the most common osteoporotic fracture, and some patients require surgical intervention to improve their impaired activities of daily living with neurological deficits. However, many previous reports have focused on OVF around the thoracolumbar junction, and the surgical outcomes of lumbar OVF have not been thoroughly discussed. We aimed to investigate the surgical outcomes for lumbar OVF with a neurological deficit. Methods: Patients who underwent fusion surgery for thoracolumbar OVF with a neurological deficit were enrolled at 28 institutions. Clinical information, comorbidities, perioperative complications, Japanese Orthopaedic Association scores, visual analog scale scores, and radiographic parameters were compared between patients with lower lumbar fracture (L3-5) and those with thoracolumbar junction fracture (T10-L2). Each patient with lower lumbar fracture (L group) was matched with to patients with thoracolumbar junction fracture (T group). Results: A total 403 patients (89 males and 314 females, mean age: 73.8 ± 7.8 years, mean follow-up: 3.9 ± 1.7 years) were included in this study. Lower lumbar OVF was frequently found in patients with lower bone mineral density. After matching, mechanical failure was more frequent in the L group (L group: 64%, T group: 39%; p < 0.001). There was no difference between groups in the clinical and radiographical outcomes, although the rates of complication and revision surgery were still high in both groups. Conclusions: The surgical intervention for OVF is effective in patients with myelopathy or radiculopathy regardless of the surgical level, although further study is required to improve clinical and radiographical outcomes. Level of evidence: Level III

Abstract Background The optimal treatment of osteoporosis after reconstruction surgery for osteoporotic vertebral fractures (OVF) remains unclear. In this multicentre retrospective study, we investigated the effects of typically used agents for osteoporosis, namely, bisphosphonates (BP) and teriparatide (TP), on surgical results in patients with osteoporotic vertebral fractures. Methods Retrospectively registered data were collected from 27 universities and affiliated hospitals in Japan. We compared the effects of BP vs TP on postoperative mechanical complication rates, implant-related reoperation rates, and clinical outcomes in patients who underwent posterior instrumented fusion for OVF. Data were analysed according to whether the osteoporosis was primary or glucocorticoid-induced. Results A total of 159 patients who underwent posterior instrumented fusion for OVF were included. The overall mechanical complication rate was significantly lower in the TP group than in the BP group (BP vs TP: 73.1% vs 58.2%, p = 0.045). The screw backout rate was significantly lower and the rates of new vertebral fractures and pseudoarthrosis tended to be lower in the TP group than in the BP group. However, there were no significant differences in lumbar functional scores and visual analogue scale pain scores or in implant-related reoperation rates between the two groups. The incidence of pseudoarthrosis was significantly higher in patients with glucocorticoid-induced osteoporosis (GIOP) than in those with primary osteoporosis; however, the pseudoarthrosis rate was reduced by using TP. The use of TP also tended to reduce the overall mechanical complication rate in both primary osteoporosis and GIOP. Conclusions The overall mechanical complication rate was lower in patients who received TP than in those who received a BP postoperatively, regardless of type of osteoporosis. The incidence of pseudoarthrosis was significantly higher in patients with GIOP, but the use of TP reduced the rate of pseudoarthrosis in GIOP patients. The use of TP was effective to reduce postoperative complications for OVF patients treated with posterior fusion.

Introduction: Symptomatic postoperative hematoma after spine surgery is a rare but serious complication. The objective of this study was to investigate the incidence and clinical features of symptomatic postoperative hematoma after spine surgery. Methods: We retrospectively identified 10,680 patients who underwent spine surgery between 2002 and 2012 in nine hospitals. We reviewed the incidence of postoperative hematoma and its clinical features, including time before onset, main symptoms, and neurological outcomes. Results: The overall incidence of symptomatic postoperative hematoma after spine surgery was 0.4% (45/10,680). Postoperative hematoma was more frequent after thoracic spine surgery than after cervical or lumbar surgery. The onset of postoperative hematoma occurred at an average of 2.6 days (range 0-14 days) postoperatively. The chief symptoms caused by postoperative hematoma after spine surgery were tetra/paraplegia in 30 patients, hemiplegia in eight patients, intractable pain in five patients, and airway dysfunction in two patients. Surgical evacuation of the spinal epidural hematoma resulted in improvement of at least one grade in 35 patients, while four patients had complete motor paralysis even after evacuation surgery. Conclusions: We report the clinical details of 45 patients with postoperative hematoma after spine surgery. This information could assist surgeons to make a prompt diagnosis and perform early evacuation surgery for postoperative hematoma following spine surgery.

Expression of Cas9 and gRNA from viral vectors in vivo may cause off-target activity. Here the authors present NanoMEDIC, which uses nanovesicles to transiently deliver editing machinery to hard-to-transfect cells.

Introduction: The prevalence of patients with osteoporosis continues to increase in aging societies, including Japan. The first choice for managing osteoporotic vertebral compression fracture (OVF) is conservative treatment. Failure in conservative treatment for OVF may lead to non-union or vertebral collapse, resulting in neurological deficit and subsequently requiring surgical intervention. This multicenter nationwide study in Japan was conducted to comprehensively understand the outcomes of surgical treatments for OVF non-union. Methods: This multicenter, retrospective study included 403 patients (89 males, 314 females, mean age 73.8 ± 7.8 years, mean follow-up 3.9 ± 1.7 years) with neurological deficit due to vertebral collapse or non-union after OVF at T10-L5 who underwent fusion surgery with a minimum 1-year follow-up. Radiological and clinical outcomes at baseline and at the final follow-up (FU) were evaluated. Results: OVF was present at a thoracolumbar junction such as T12 (124 patients) and L1 (117 patients). A majority of OVF occurred after a minor trauma, such as falling down (55.3%) or lifting objects (8.4%). Short segment fusion, including affected vertebra, was conducted (mean 4.0 ± 2.0 vertebrae) with 256.8 minutes of surgery and 676.1 g of blood loss. A posterior approach was employed in 86.6% of the patients, followed by a combined anterior and posterior (8.7%), and an anterior (4.7%) approach. Perioperative complications and implant failures were observed in 18.1% and 41.2%, respectively. VAS scores of low back pain (74.7 to 30.8 mm) and leg pain (56.8 to 20.7 mm) improved significantly at FU. Preoperatively, 52.6% of the patients were unable to walk and the rate of non-ambulatory patients decreased to 7.5% at FU. Conclusions: This study demonstrated that substantial improvement in activity of daily living (ADL) was achieved by fusion surgery. Although there was a considerable rate of complications, fusion surgery is beneficial for elderly OVF patients with non-union.

Adolescent idiopathic scoliosis (AIS) is a common pediatric disease leading to spinal deformities. Here, the authors report GWAS followed by genome-wide meta-analysis in up to 79,211 Japanese individuals, identifying 20 genetic loci for AIS, 14 of which were previously unreported, and perform in vitro validation for rs1978060.

Abstract Background This study was conducted to determine gender differences in the relationship between extracurricular sports activities (ECSA) and low back pain (LBP) in children and adolescents. Methods In a cohort analysis of a 6-year birth cohort annual survey, students were followed from the fourth to sixth grades of elementary school (E4–E6; 9–12 years old) through the first to third grades of junior high school (J1–J3; 12–15 years old). All students completed annual questionnaires on ECSA and LBP. The odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association strength between ECSA and LBP. We also calculated the population attributable fraction (PAF), which was defined as the proportion of students with ECSA-related LBP among all students with LBP. Results ECSA was significantly associated with LBP only in grade J3 among boys (OR: 2.00, 95% CI: 1.47–2.71). On the other hand, among girls, ECSA was significantly associated with LBP in grades E5 (OR: 1.48, 95% CI: 1.00–2.20), E6 (OR: 1.91, 95% CI: 1.33–2.75), and J3 (OR: 1.81, 95% CI: 1.26–2.61). Among boys, PAF was similar in all grades (range, 10–16%), whereas among girls, the PAF varied (− 11 to 29%) and was significantly higher in girls than in boys in grades E5 (19.0% vs. 1.1%, P

The chemical bonding structure of porous low-k carbon-doped silicon oxide (SiOC) films (k

Introduction: Approximately 3% of osteoporotic vertebral fractures develop osteoporotic vertebral collapse (OVC) with neurological deficits, and such patients are recommended to be treated surgically. However, a proximal junctional fracture (PJFr) following surgery for OVC can be a serious concern. Therefore, the aim of this study is to identify the incidence and risk factors of PJFr following fusion surgery for OVC. Methods: This study retrospectively analyzed registry data collected from facilities belonging to the Japan Association of Spine Surgeons with Ambition (JASA) in 2016. We retrospectively analyzed 403 patients who suffered neurological deficits due to OVC below T10 and underwent corrective surgery; only those followed up for 2 years were included. Potential risk factors related to the PJFr and their cut-off values were calculated using multivariate logistic regression analysis and receiver operating characteristic (ROC) analysis. Results: Sixty-three patients (15.6%) suffered PJFr during the follow-up (mean 45.7 months). In multivariate analysis, the grade of osteoporosis (grade 2, 3: adjusted odds ratio (aOR) 2.92; p=0.001) and lower instrumented vertebra (LIV) level (sacrum: aOR 6.75; p=0.003) were independent factors. ROC analysis demonstrated that lumbar bone mineral density (BMD) was a predictive factor (area under curve: 0.72, p=0.035) with optimal cut-off value of 0.61 g/cm2 (sensitivity, 76.5%; specificity, 58.3%), but that of the hip was not (p=0.228). Conclusions: PJFr was found in 16% cases within 4 years after surgery; independent risk factors were severe osteoporosis and extended fusion to the sacrum. The lumbar BMD with cut-off value 0.61 g/cm2 may potentially predict PJFr. Our findings can help surgeons select perioperative adjuvant therapy, as well as a surgical strategy to prevent PJFr following surgery.

Study Design Retrospective case series. Purpose To investigate the oncological outcomes, including distant relapse, after en bloc spondylectomy (EBS) for spinal metastases in patients with a minimum of 2-year follow-up. Overview of Literature Although EBS has been reported to be locally curative and extend survival in select patients with spinal metastases, detailed reports regarding the control of distant relapse after EBS are lacking. Methods We conducted a retrospective review of 18 consecutive patients (median age at EBS, 62 years; range, 40–77 years) who underwent EBS for spinal metastases between 1991 and 2015. The primary cancer sites included the kidney (n=7), thyroid (n=4), liver (n=3), and other locations (n=4). Survival rates were estimated using the Kaplan–Meier method, and groups were compared using the log-rank method. Results The median operative time and intraoperative blood loss were 767.5 minutes and 2,375 g, respectively. Twelve patients (66.7%) experienced perioperative complications. Five patients (27.8%) experienced local recurrence of the tumor at a median of 12.5 months after EBS, four of which had a positive resection margin status. Thirteen patients (72.2%) experienced distant relapse at a median of 21 months after EBS. The estimated median survival period after distant relapse was 20 months (95% confidence interval, 0.71–39.29 months). No association was found between resection margin status and distant relapse. Overall, the 2-year, 5-year, and 10-year survival rates after EBS were 72.2%, 48.8%, and 27.1%, respectively. Importantly, the era in which EBS was performed did not impact the oncological outcomes. Conclusions Our results suggest that EBS by itself, even if margin-free, cannot prevent further dissemination, which occurred in >70% of patients at a median of 21 months after EBS. These results should be considered and conveyed to patients for clinical decision-making.

Abstract Background To date, there have been little published data on surgical outcomes for patients with PD with thoracolumbar OVF. We conducted a retrospective multicenter study of registry data to investigate the outcomes of fusion surgery for patients with Parkinson’s disease (PD) with osteoporotic vertebral fracture (OVF) in the thoracolumbar junction. Methods Retrospectively registered data were collected from 27 universities and their affiliated hospitals in Japan. In total, 26 patients with PD (mean age, 76 years; 3 men and 23 women) with thoracolumbar OVF who underwent spinal fusion with a minimum of 2 years of follow-up were included (PD group). Surgical invasion, perioperative complications, radiographic sagittal alignment, mechanical failure (MF) related to instrumentation, and clinical outcomes were evaluated. A control group of 296 non-PD patients (non-PD group) matched for age, sex, distribution of surgical procedures, number of fused segments, and follow-up period were used for comparison. Results The PD group showed higher rates of perioperative complications (p

Abstract Background A precise comparison of supine and standing whole spine alignment in both the coronal and sagittal planes, including the pelvic parameters, has not been reported. Furthermore, previous studies investigated positional differences in the Cobb angle only in young patients with idiopathic scoliosis. The difference in alignment has never been investigated in a population of patients with adult spinal deformity (ASD). In most cases, ASD patients are aware of the symptoms when standing and tend to stoop with back pain, whereas the symptoms disappear when lying on a bed. Therefore, it is important to elucidate the positional differences in the deformity in older adults. The purposes of this study are to establish a method for comparing whole spine alignment between supine and standing, and to clarify the positional difference of the alignment in the patients with ASD. Methods Twenty-four patients with ASD (mean age: 60.1 years, range 20–80 years; 24 women) were evaluated. A slot-scanning three-dimensional X-ray imager (EOS) was used to assess the whole spine in the standing position. Computed tomography was used to assess the whole spine in the supine position. The computed tomography DICOM dataset of the whole spine in the supine position was transformed to two-dimensional (coronal and sagittal) digital reconstructed radiography images. The digital reconstructed radiography images were input for three-dimensional measurement by the EOS software and compared with the standing whole spine alignment measured by EOS. Results The mean intraclass correlation coefficients (supine, standing) of intra-rater / inter-rater reliabilities for the measured parameters were 0.981, 0.984 / 0.970, 0.986, respectively. The Cobb and rotation angles of the major curve, mostly the thoracolumbar area, were significantly greater in the standing position than in the supine position. Lumbar lordosis during standing was significantly kyphotic. With respect to the pelvic parameters, the sacral slope was significantly smaller in the standing position than in the supine position. Pelvic tilt and pelvic incidence were significantly greater in the standing position than in the supine position. Conclusions The lumbar to pelvic parameters and the major curve in standing position significantly deteriorate compared with the supine position in patients with ASD.

Abstract Background In patients with ossification of the posterior longitudinal ligament (OPLL) in the cervical spine, it is well known that the thoracic ossified lesions often coexist with the cervical lesions and can cause severe myelopathy. However, the prevalence of OPLL at each level of the thoracic and lumbar spinal segments is unknown. The aims of this study were to investigate how often OPLL occurs at each level in the thoracolumbar spine in patients with a radiological diagnosis of cervical OPLL and to identify the spinal levels most likely to develop ossification. Methods Data were collected from 20 institutions in Japan. Three hundred and twenty-two patients with a diagnosis of cervical OPLL were included. The OPLL index (OP index), defined as the sum of the vertebral body and intervertebral disc levels where OPLL is present, was used to determine disease severity. An OP index ≥20 was defined as severe OPLL. The prevalence of OPLL at each level of the thoracic and lumbar spinal segments was calculated. Results Women were more likely to have ossified lesions in the thoracolumbar spine than men. Severe OPLL was significantly more common in women than in men (20% vs. 4.5%). For thoracic vertebral OPLL, the most frequently affected was the T1 segment in both men and women, followed by the T1/2 and T3/4 intervertebral levels in men and women, respectively. Ossified lesions were frequently seen at the intervertebral and vertebral levels around the cervicothoracic and thoracolumbar junctions in men with severe OPLL, whereas OPLL was more diffusely distributed in the thoracic spine in women with severe OPLL. Conclusion Thoracolumbar OPLL occurred most often at T1 in men and at T3/4 in women. In severe OPLL cases, although ossified lesions were frequently seen at the intervertebral and vertebral levels around the cervicothoracic and thoracolumbar junctions in men, OPLL could be observed more diffusely in the thoracic spine in women.

Introduction: With an aging population, the proportion of patients aged 80 years requiring cervical surgery is increasing. Surgeons are concerned with the high incidence of complications in this population, because “age” itself has been reported as a strong risk factor for complications. However, it is still unknown which factors represent higher risk among these elderly patients. Therefore, this study was conducted to identify the risk factors related to surgical complications specific to elderly patients by analyzing the registry data of patients aged 80 years who underwent cervical surgery. Methods: We retrospectively studied multicenter collected registry data using multivariate analysis. Sixty-six patients aged 80 years who underwent cervical surgery and were followed up for more than one year were included in this study. Preoperative patient demographic data, including comorbidities and postoperative complications, were collected from multicenter registry data. Complications were considered as major if they required invasive intervention, caused prolonged morbidity, or resulted in prolongation of hospital stay. Logistic regression analysis was performed to analyze the risk factors for complications. A p-value of

Purpose: This study aimed to investigate radiographic outcomes after posterior spinal fusion (PSF) for pediatric patients younger than 10 years with upper cervical disorders. Methods: Thirteen patients (mean age at surgery, 5.9 years; range, 1 to 9 years) who underwent PSF with a minimum of 2 years of follow-up (mean, 5.8 years) were included. Diagnoses were atlanto-axial instability due to congenital disorders for 11 patients and atlanto-axial rotatory fixation for 2 patients. The fusion area was occipito-cervical for 7 patients and C1/2 for 6 patients. PSF was performed using rigid screw-rod constructs for 6 patients and conventional techniques for 7 patients. Ten patients required halo immobilization after surgery. Fusion status, perioperative complications, radiographic alignment, and range of motion (ROM) from C2 to C7 were evaluated. Results: Twelve patients successfully achieved bony fusion (fusion rate, 92%), but complications occurred in 5 patients. Regarding radiographic measures (preoperative/postoperative/final follow-up), the mean atlanto-dental interval was significantly reduced (8.0 mm/2.7 mm/3.5 mm) and the C2-7 ROM was increased (from 49.4 degrees to 66.0 degrees) at the final follow-up (both comparisons, p

Although most red algae produce agar and carrageenan, Gloiopeltis furcata produces funoran as polysaccharide component. In this study, the complete G. furcata mitochondrial genome was determined. It had a circular mapping molecular with the length of 25,636 bp and contained 49 genes including 24 protein-coding, two rRNA, and 23 tRNA. Phylogenetic analysis showed that G. furcata was separated with the other polysaccharide-producing red algae. This is the first report of complete mitochondrial genome from funoran producing red algae.

Black granular single crystals of monotitanium dibismuth, TiBi2, were synthesized by slow cooling of a mixture of Bi and Ti from 693 K. The title compound is isostructural with CuMg2 (orthorhombic Fddd symmetry). Ti atoms are located in square antiprisms of Bi atoms. The network of one type of Bi atom spirals along the a-axis direction while honeycomb layers of the other type of Bi atom spreading in the ab plane interlace one another.

BACKGROUND:Bedridden patients are at risk of osteoporosis and fractures, although the long-term bone metabolic processes in these patients are poorly understood. Therefore, we aimed to determine how long-term bed confinement affects bone metabolism. METHODS:This study included 36 patients who had been bedridden from birth due to severe immobility. Bone mineral density and bone metabolism markers were compared to the bedridden period in all study patients. Changes in the bone metabolism markers during a follow-up of 12 years were studied in 17 patients aged

Ossification of the posterior longitudinal ligament (OPLL) can cause severe and irreversible paralysis in not only the cervical spine but also the thoracolumbar spine. To date, however, the prevalence and distribution of OPLL in the whole spine has not been precisely evaluated in patients with cervical OPLL. Therefore, we conducted a multi-center study to comprehensively evaluate the prevalence and distribution of OPLL using multi-detector computed tomography (CT) images in the whole spine and to analyze what factors predict the presence of ossified lesions in the thoracolumbar spine in patients who were diagnosed with cervical OPLL by plain X-ray. Three hundred and twenty-two patients with a diagnosis of cervical OPLL underwent CT imaging of the whole spine. The sum of the levels in which OPLL was present in the whole spine was defined as the OP-index and used to evaluate the extent of ossification. The distribution of OPLL in the whole spine was compared between male and female subjects. In addition, a multiple regression model was used to ascertain related factors that affected the OP-index. Among patients with cervical OPLL, women tended to have more ossified lesions in the thoracolumbar spine than did men. A multiple regression model revealed that the OP-index was significantly correlated with the cervical OP-index, sex (female), and body mass index. Furthermore, the prevalence of thoracolumbar OPLL in patients with a cervical OP-index ≥ 10 was 7.8 times greater than that in patients with a cervical OP-index ≤ 5. The results of this study reveal that the extent of OPLL in the whole spine is significantly associated with the extent of cervical OPLL, female sex, and obesity.

Microphthalmia is a severe ocular disorder, and this condition is typically caused by mutations in transcription factors that are involved in eye development. Mice carrying mutations in these transcription factors would be useful tools for defining the mechanisms underlying developmental eye disorders. We discovered a new spontaneous recessive microphthalmos mouse mutant in the Japanese wild-derived inbred strain KOR1/Stm. The homozygous mutant mice were histologically characterized as microphthalmic by the absence of crystallin in the lens, a condition referred to as aphakia. By positional cloning, we identified the nonsense mutation c.444C>A outside the genomic region that encodes the homeodomain of the paired-like homeodomain transcription factor 3 gene (Pitx3) as the mutation responsible for the microphthalmia and aphakia. We examined Pitx3 mRNA expression of mutant mice during embryonic stages using RT-PCR and found that the expression levels are higher than in wild-type mice. Pitx3 over-expression in the lens during developmental stages was also confirmed at the protein level in the microphthalmos mutants via immunohistochemical analyses. Although lens fiber differentiation was not observed in the mutants, strong PITX3 protein signals were observed in the lens vesicles of the mutant lens. Thus, we speculated that abnormal PITX3, which lacks the C-terminus (including the OAR domain) as a result of the nonsense mutation, is expressed in mutant lenses. We showed that the expression of the downstream genes Foxe3, Prox1, and Mip was altered because of the Pitx3 mutation, with large reductions in the lens vesicles in the mutants. Similar profiles were observed by immunohistochemical analysis of these proteins. The expression profiles of crystallins were also altered in the mutants. Therefore, we speculated that the microphthalmos/aphakia in this mutant is caused by the expression of truncated PITX3, resulting in the abnormal expression of downstream targets and lens fiber proteins.

We discovered a new cataract mutation, kfrs4, in the Kyoto Fancy Rat Stock (KFRS) background. Within 1 month of birth, all kfrs4/kfrs4 homozygotes developed cataracts, with severe opacity in the nuclei of the lens. In contrast, no opacity was observed in the kfrs4/+ heterozygotes. We continued to observe these rats until they reached 1 year of age and found that cataractogenesis did not occur in kfrs4/+ rats. To define the histological defects in the lenses of kfrs4 rats, sections of the eyes of these rats were prepared. Although the lenses of kfrs4/kfrs4 homozygotes showed severely disorganised fibres and vacuolation, the lenses of kfrs4/+ heterozygotes appeared normal and similar to those of wild-type rats. We used positional cloning to identify the kfrs4 mutation. The mutation was mapped to an approximately 9.7-Mb region on chromosome 7, which contains the Mip gene. This gene is responsible for a dominant form of cataract in humans and mice. Sequence analysis of the mutant-derived Mip gene identified a 5-bp insertion. This insertion is predicted to inactivate the MIP protein, as it produces a frameshift that results in the synthesis of 6 novel amino acid residues and a truncated protein that lacks 136 amino acids in the C-terminal region, and no MIP immunoreactivity was observed in the lens fibre cells of kfrs4/kfrs4 homozygous rats using an antibody that recognises the C- and N-terminus of MIP. In addition, the kfrs4/+ heterozygotes showed reduced expression of Mip mRNA and MIP protein and the kfrs4/kfrs4 homozygotes showed no expression in the lens. These results indicate that the kfrs4 mutation conveys a loss-of-function, which leads to functional inactivation though the degradation of Mip mRNA by an mRNA decay mechanism. Therefore, the kfrs4 rat represents the first characterised rat model with a recessive mutation in the Mip gene.