Factors associated with death, hospitalization, resignation, and sick leave from work among patients with schizophrenia in Japan: a nested case-control study using a large claims database.

BACKGROUND: Premature mortality, frequent relapse that easily leads to hospitalization, and discontinuous employment are key challenges for the treatment of schizophrenia. We evaluated risk factors for important clinical outcomes (death, hospitalization, resignation, and sick leave from work) in patients with schizophrenia in Japan. METHODS: A nested case-control study was conducted for patients with schizophrenia identified in a Japanese claims database. For each outcome, the case was matched with up to four controls of the same age, sex, index year, and enrollment status (employee or dependent family). Potential risk factors were defined by prescriptions or diagnoses within 3 months prior to or in the month of the event. The association among potential risk factors and each outcome was evaluated using multivariable conditional logistic regression analysis with stepwise variable selection. RESULTS: The number of cases and eligible patients for each outcome were 144 and 38,451 (death), 1,520 and 35,225 (hospitalization), 811 and 18,770 (resignation), and 4,590 and 18,770 (sick leave), respectively. Depression was a risk factor for death (odds ratio [OR]: 1.92; 95% confidence interval [CI]: 1.12, 3.29), hospitalization (OR: 1.22; 95% CI: 1.05, 1.42), and sick leave from work (OR: 1.46; 95% CI: 1.36, 1.57). Other risk factors for death were hospitalization history, Charlson Comorbidity Index (CCI) score, and prescription for laxatives. Prescriptions for hypnotics, laxatives, and anticholinergics were risk factors for hospitalization. Prescriptions for hypnotics and anticholinergics were risk factors for resignation. CCI score, prescription for hypnotics, laxatives, and antidiabetics were risk factors for sick leave from work. CONCLUSIONS: Our findings suggest that depression and some physical symptoms, such as constipation and extrapyramidal symptoms, are risk factors for important clinical outcomes in patients with schizophrenia. Attention should be paid to both depression and physical symptoms for the treatment of schizophrenia.

Spinopelvic fusion surgery from lower thoracic spine to pelvis increased hip joint moment-motion analysis.

PURPOSE: Spinal fusion surgery is often performed with pelvic fixation to prevent distal junctional kyphosis. The inclusion of spinopelvic fixation has been reported to induce progression of hip joint arthropathy in a radiographic follow-up study. However, its biomechanical mechanism has not yet been elucidated. This study aimed to compare the changes in hip joint moment before and after spinal fusion surgery. METHODS: This study was an observational study and included nine patients (eight women and one man) who were scheduled to undergo spinopelvic fusion surgery. We calculated the three-dimensional external joint moments of the hip during gait, standing, and climbing stairs before and 1 year after surgery. RESULTS: During gait, the maximum extension moment was 0.51 ± 0.29 and 0.63 ± 0.40 before and after spinopelvic fusion surgery (p = 0.011), and maximum abduction moment was 0.60 ± 0.33 and 0.83 ± 0.34 before and after surgery (p = 0.004), respectively. During standing, maximum extension moment was 0.76 ± 0.32 and 1.04 ± 0.21 before and after spinopelvic fusion surgery (p = 0.0026), and maximum abduction moment was 0.12 ± 0.20 and 0.36 ± 0.22 before and after surgery (p = 0.0005), respectively. During climbing stairs, maximum extension moment was - 0.31 ± 0.30 and - 0.48 ± 0.15 before and after spinopelvic fusion surgery (p = 0.040), and maximum abduction moment was 0.023 ± 0.18 and - 0.02 ± 0.13 before and after surgery (p = 0.038), respectively. CONCLUSION: This study revealed that hip joint flexion-extension and abduction-adduction moments increased after spinopelvic fixation surgery in the postures of standing, walking, and climbing stairs. The mechanism was considered to be adjacent joint disease after spinopelvic fusion surgery including sacroiliac joint fixation.

Nucleic Acid-to-Small Molecule Converter through Amplified Hairpin DNA Circuits.

Many microRNAs (miRNAs) are characteristically found in cancer cells, making miRNAs promising marker biomolecules for cancer diagnosis and therapeutics. However, it is challenging to use miRNA as a cancer signature because it is difficult to convert the nucleic acid sequence information into molecular functionality. To address this challenge, we realize nucleic acid-to-small molecule converters using hairpin DNA circuits. Harnessing a Staudinger reduction as a trigger for the conversion, we constructed hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA) circuits that respond to oncogenic miR-21. Fluorophore and dye molecules were released in response to miR-21 through the HCR, providing fluorogenic and chromogenic readouts. Selective cytotoxicity in miR-21-abundant cells was realized by the CHA to release the anticancer drug SN-38. This would be the first example of selective activation of a small-molecule prodrug triggered by oncogenic miRNA in human living cells.

S2 alar-iliac screw loosening as a preventive factor for hip joint osteoarthritis after adult spinal deformity surgery: a case-control study.

PURPOSE: This study aimed to evaluate the progression of hip pathology and risk factors after ASD surgery. METHODS: This case-control study enrolled 123 patients (246 hips); seven hips underwent hip arthroplasty were excluded. We measured the center-edge (CE) angle, joint space width (JSW), and Kellgren-Lawrence (KL) grade. We defined a CE angle˂25° as developmental dysplasia of the hip (DDH). We evaluated S2 alar-iliac (AI) screw loosening at final follow-up. RESULTS: The annual decrease in the JSW was 0.31 mm up to 1 year, and 0.13 mm after 1 year (p = 0.001). KL grade progression occurred in 24 hips (10.0%; group P), while no progression occurred in 215 (90.0%; group N) hips. Nonparametric analysis between groups P and N revealed that significant differences were observed in sex, DDH, KL grade, ratio of S2AI screw fixation at baseline, and ratio of S2AI screw loosening at final follow-up. Multiple logistic regression analysis revealed that DDH (p = 0.018, odds ratio (OR) = 3.0, 95%CI = 1.2-7.3), baseline KL grade (p < 0.0001, OR = 37.7, 95%CI = 7.0-203.2), and S2AI screw fixation (p = 0.035, OR = 3.4, 95%CI = 1.1-10.4) were significant factors. We performed sub-analysis to elucidate the relationship between screw loosening and hip osteoarthritis in 131 hips that underwent S2AI screw fixation. Non-loosening of the S2AI screw was a significant factor for KL grade progression (p < 0.0001, OR = 8.9, 95%CI = 3.0-26.4). CONCLUSION: This study identified the prevalence and risk factors for the progression of hip osteoarthritis after ASD surgery. Physicians need to pay attention to the hip joint pathology after ASD surgery.

Health Related Quality of Life Over Time After Revascularisation in Patients With Chronic Limb Threatening Ischaemia.

OBJECTIVE: Chronic limb threatening ischaemia (CLTI) decreases life expectancy and impairs health related quality of life (HR-QOL). Revascularisation is needed to relieve ischaemia and salvage limbs. Although a major goal of CLTI treatment is maintaining QOL, little information is available about changes of HR-QOL over time after revascularisation. HR-QOL with survival after revascularisation for CLTI was assessed. METHODS: The clinical database of the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia (SPINACH), a prospective multicentre observational study, was analysed. Outcome measures were disease specific QOL per the Vascular Quality of Life (VascuQOL) questionnaire and the Short Form (SF) 36 evaluated generic QOL, which were assessed at baseline and three, 12, 24, and 36 months. The outcome measure was change of QOL from baseline. The minimally important difference (half a standard deviation from baseline) was used as the cut off point for improved, worsened, and unchanged QOL. RESULTS: Overall QOL was improved in 61% of patients for the VascuQOL and approximately 40% for the SF-36 component summaries at three months. However, these proportion gradually decreased to 21% - 31% at three years. In contrast, the proportion of deceased patients gradually increased over the three year follow up. Multivariable analysis revealed that pre-operative non-ambulatory status was inversely associated with improved QOL for the three month VascuQOL and SF-36 mental component summary, and surgical reconstruction was positively associated with these measurements. Advanced age and renal failure were inversely associated with improved QOL for the SF-36 mental component summary and VascuQOL at one to three years. CONCLUSION: Revascularisation improved QOL. However, patients with non-ambulatory status exhibited a negative association with improved QOL at three months, and advanced age and renal failure limited benefits one to three years after revascularisation. Accumulating QOL data will be essential for post-revascularisation QOL estimation. Pre-operative assessment, including estimated QOL, is important in shared decision making for patient oriented outcomes in the treatment of CLTI patients.

Adjacent segment disease on hip joint as a complication of spinal fusion surgery including sacroiliac joint fixation.

PURPOSE: Recently, the number of adult spinal deformity surgeries including sacroiliac joint fixation (SIJF) by using an S2 alar iliac screw or iliac screw has increased to avoid the distal junctional failure. However, we occasionally experienced patients who suffered from hip pain after a long instrumented spinal fusion. We hypothesized that long spinal fusion surgery including SIJF influenced the hip joint as an adjacent joint. The aim of this paper was to evaluate the association between spinal deformity surgery including SIJF and radiographic progression of hip osteoarthritis (OA). METHODS: This study was retrospective cohort study. In total, 118 patients who underwent spinal fusion surgery at single center from January 2013 to August 2018 were included. We measured joint space width (JSW) at central space of the hip joint. We defined reduction of more than 0.5 mm/year in JSW as hip OA progression. The patients were divided into two groups depending on either a progression of hip osteoarthritis (Group P), or no progression (Group N). RESULTS: The number of patients in Group P and Group N was 47 and 71, respectively. Factor that was statistically significant for hip OA was SIJF (p = 0.0065, odds ratio = 7.1, 95% confidence interval = 1.6-31.6). There were no other significant differences by the multiple logistic regression analysis. CONCLUSION: This study identified spinal fixation surgery that includes SIJF as a predictor for radiographic progression of hip OA over 12 months. We should pay attention to hip joint lesions after adult spinal deformity surgery, including SIJF.

Live-Cell Sensing of Telomerase Activity by Using Hybridization-Sensitive Fluorescent Oligonucleotide Probes.

Live-cell sensing of telomerase activity with simple and efficient strategies remains a challenging target. In this work, a strategy for telomerase sensing by using hybridization-sensitive fluorescent oligonucleotide probes is reported. In the presence of telomerase and dNTPs, the designed supporting strand was extended and generated the hairpin structure that catalyzed the next telomerase extending reaction. The special extension mechanism increased the local concentration of another supporting strand and telomerase, which resulted in enhanced telomerase activity. The hybridization-sensitive oligonucleotide probes bound to the hairpin catalyst and generated turn-on fluorescence. This method realized the sensing of telomerase activity in HeLa cell extract with a detection limit below 1.6×10-6  IU µL-1 . The real-time in situ observation of telomerase extension was achieved in living HeLa cells. This strategy has been applied to monitor the efficiency of telomerase-targeting anticancer drugs in situ.

Preoperative psychological factors affecting surgical satisfaction of elderly patients with lumbar spinal stenosis.

OBJECTIVE: The objective of this observational study was to investigate the effects of preoperative psychological factors on short-term patient satisfaction with surgery in elderly patients with lumbar spinal stenosis (LSS). METHODS: Surgery was performed on 90 elderly patients with clinically and radiologically defined LSS: mean age at surgery, 73 years; 46 men and 44 women. Patients completed questionnaires before surgery and 1 year postoperatively. They used a self-administered the Roland Morris Disability Questionnaire (RDQ), the Japanese Orthopaedic Association Back Pain Questionnaire (JOABPEQ), MOS 36-Item Short-Form Health Survey (SF-36), and satisfaction for surgery (VAS) were completed. At baseline, psychological factors were assessed using the Self-Rating Questionnaire for Depression (SRQ-D), Hospital Anxiety and Depression scale (HADS), Pain Catastrophizing Scale (PCS), Pain Anxiety Symptoms Scale-20, and Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP). At follow-up, patient satisfaction was evaluated using 2 items: (1) satisfaction with surgery and (2) Would you undergo the same surgery again?. RESULTS: Satisfaction item 1 correlated negatively with the VAS for low back pain, leg pain, numbness, JOABPEQ social life disturbance score, SF-36 physical function score, and HADS anxiety score (p < 0.05). Satisfaction 2 correlated negatively with age at surgery, VAS of leg pain, PCS magnification score, and BS-POP score (p < 0.05). Multiple regression analysis showed significant associations between satisfaction 1 and SF-36 physical function and HADS anxiety scores, and between satisfaction 2 and PCS magnification score (p < 0.05). STATISTICAL ANALYSIS: The preoperative factors independently associated with surgical satisfaction were analyzed utilizing Speaman's rank correlation coefficient and multiple regression analysis. CONCLUSION: Physical function and anxiety were identified as preoperative factors that affected patient satisfaction with surgery. Preoperative assessment of psychological factors and interventions for anxiety may help improve patient satisfaction after surgery for LSS.

Nontraumatic Proximal Ulnar Artery Pseudoaneurysm Mimicking a Soft Tissue Tumor in Image Modality.

Aneurysm of the proximal ulnar artery is extremely rare. Ultrasonography, computed tomography, and magnetic resonance imaging generally provide accurate diagnosis of aneurysm. A 29-year-old woman who had undergone an excision biopsy of a mass in her right arm by an orthopedic surgeon was referred to our department. We resected the mass and interposed it with a reversed great saphenous vein. Histopathological examination suggested that the mass was a pseudoaneurysm consisting of organized thrombi with recanalization. Clinicians should be aware of the possibility of misdiagnosis of soft tissue tumor in cases of pseudoaneurysm, especially if imaging examination reveals a density consistent with organized thrombus with recanalization.

Stress enhances gait disturbance induced by lumbar disc degeneration in rat.

PURPOSE: Although psychological factors are assumed to be the primary cause of stress-related back pain, there have been no studies of the relationships between stress and low back pain in an animal model. The purpose of this study was to examine the influence of specific alternation of rhythm in temperature (SART) stress on gait abnormality using the CatWalk method in a rat model of low back pain caused by lumbar facetectomy. METHODS: Sixty rats were divided into three groups: the control, sham and experimental groups. Each group was then divided into non-SART stress and SART stress subgroups. We evaluated the behavioral changes 7 weeks postoperatively using the von Frey test and the CatWalk method. RESULTS: Threshold values for the hind paw in the SART stress subgroups were significantly lower than those in the non-SART stress subgroups. In the experimental group, significant changes by CatWalk in step cycle, stand time and average speed were observed under non-SART stress conditions, but SART stress resulted in additional significant changes in not only these parameters, but in other parameters including the duty cycle and swing time, compared with those in the control and sham groups. CONCLUSIONS: The demonstration by CatWalk analysis may indicate that SART stress enhanced gait disturbance. In this animal model, we demonstrated for the first time that stress may be a factor involved in worsening of low back pain.

A comparative study of 2-year follow-up outcomes in lumbar spinal stenosis patients treated with physical therapy alone and those with surgical intervention after less successful physical therapy.

BACKGROUND: The efficacy of physical therapy for patients with lumbar spinal stenosis (LSS) has been reported only for the short term, and few reports have compared outcomes of surgical treatment with nonsurgical treatment after physical therapy. The purpose of this study was to assess 2-year outcomes of LSS patients treated with surgery or under follow-up observation after physical therapy for 6 weeks. METHODS: Patients presenting with neurogenic claudication, radiologically-confirmed central LSS affecting both legs and refractory symptoms to pharmacotherapy of more than 3 months were enrolled. Patients were treated with manual therapy, stretching and strengthening exercises, and body weight-supported treadmill walking once a week for 6 weeks. Clinical outcomes were measured using the Zurich Claudication Questionnaire (ZCQ), visual analog scale of low back pain, leg pain, and numbness, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire and the SF-36. Two years after physical therapy, patients were classified into the observation group (Group I) or the surgery group (Group II), whose patients failed to respond to physical therapy and wanted to undergo surgery. RESULTS: Thirty-eight patients were enrolled; 28 had complete data at 2 years: 21 and 7 in Groups I and II, respectively. Group II had a higher body mass index (BMI) than Group I. There were no significant differences in clinical outcomes at baseline. Six weeks after physical therapy, Group I had significantly better outcomes for symptom severity and physical function on the ZCQ subscales, physical functioning and bodily pain on the SF-36 subscales. These outcomes in Group I were maintained or improved and did not differ significantly between groups at 2-years. However, the physical function on the ZCQ subscales was improved in Group II more than those in Group I (mean difference -0.6; 95% CI: -1.2 to -0.03, P < 0.05) at 2 years. CONCLUSIONS: At 2 years, the outcomes except for the change in physical function score in the ZCQ subscale did not differ significantly between patients who had undergone surgery and those who avoided surgery.

Peripartum Iliac Arterial Aneurysm and Rupture in a Patient with Vascular Ehlers-Danlos Syndrome Diagnosed by Next-Generation Sequencing.

Vascular Ehlers-Danlos syndrome (vEDS), a genetic disorder caused by mutations in procollagen type III gene (COL3A1), may lead to fatal vascular complication during peripartum period because of the arterial fragility. We experienced a case of vEDS with peripartum life-threatening arterial rapture diagnosed by next-generation sequencing (NGS) and successfully treated the vascular complications. A 25-year-old female in pregnancy at 34 weeks had sudden and acute pain in the left lower abdomen. After successful delivery, her computed tomography scan showed a dissecting aneurysm of the left common iliac artery (CIA). Four days after delivery, she presented in hemorrhagic shock induced by arterial rupture in the CIA. Since her clinical presentations inferred vEDS even in the absence of familial history, we performed NGS-based genetic screening for inherited connective tissue disorders including vEDS with informed consent. Even though we started intensive medication, her iliac aneurysm was progressively enlarging within 3 weeks. After an urgent molecular diagnosis for vEDS (a splice-site mutation), cautious endovascular therapy for her CIA aneurysm was successfully performed. This is the first report for pretreatment molecular diagnosis of vEDS using NGS in an emergent situation of severe vascular complications.

[Successful Treatment with Aortic Stent Graft and Transcatheter Embolization for Bronchial Artery Aneurysm].

We report a case of bronchial artery aneurysm (BAA) successfully treated with a combination of transcatheter embolization and stent graft. A 50-year-old woman was referred to our hospital for further examination of a hemispherical bulging lesion on the middle esophagus detected by gastroscopy. Computed tomography (CT) revealed BAA with a 15 mm-diameter arising from the descending aorta on the left side of the esophagus. We performed transcatheter embolization combined with a stent graft because of a short neck. Postoperative course was uneventful. Follow-up CT showed complete isolation of the blood flow into the BAA. BAA is rare and often found incidentally by diagnostic imaging as shown in our case. Prompt treatment with complete isolation of blood inflow is required because the rupture of BAA is life-threatening.

Reduced blood loss and operation time in lumbar posterolateral fusion using a bipolar sealer.

PURPOSE: A bipolar sealer using Transcollation® technology, a combination of radiofrequency energy and saline, can provide hemostasis at 100 °C, which is lower than that used in standard electrocautery. Previous studies of joint arthroplasty have shown that use of the bipolar sealer reduces blood loss and tissue damage during the operation. However, it is unknown whether a bipolar sealer reduces blood loss and tissue damage in lumbar posterolateral fusion (PLF) surgery. The purpose of this study was to analyze the efficacy of this device in limiting blood loss during exposure of the lumbar spine in the treatment of PLF and postoperative pain. METHODS: Fifty patients who underwent PLF were prospectively enrolled between October 2011 and March 2013. Twenty-five patients were randomized to the bipolar sealer group (BS group) and 25 patients to the standard electrocautery group (control group). Operative time and blood loss during exposure of posterior bony elements including the transverse process for PLF, visual analog scale (VAS) to quantify postoperative pain, and the interval from the surgery to hospital discharge were compared. RESULTS: Operative time and blood loss expressed per level of exposure were significantly lower in the BS group than in the control group. There was a tendency toward a lower VAS at postoperative week 1 in the BS group. The duration of hospitalization was 15 and 26 days in the BS and control groups, respectively. CONCLUSIONS: A large randomized control trial adjusted for the number of fusion levels and body mass index is required to confirm the novelty value of this new bipolar sealers.

Three-dimensional micro-computed tomography analysis for spinal instability after lumbar facetectomy in the rat.

PURPOSE: Intervertebral disc degeneration is thought to contribute to low back pain. However, the pathophysiological mechanisms remain controversial. In a previous study, we developed an animal model that showed delayed gait disturbance after lumbar facetectomy in the rat. We believe that this gait disturbance was caused by low back pain, although the mechanisms of this gait abnormality remain unknown. The purpose of this study was to evaluate structural changes of the lumbar spine after facetectomy in the rat utilizing three-dimensional micro-computed tomography (3DµCT) compared to histology. METHODS: Thirty male SD rats were divided into three groups. In the Sham group (n = 13), only exposure of bilateral facet joints at the L4-5 level was performed. In the Experimental group (n = 13), complete resection of bilateral L4-5 facet joints was achieved. Naïve rats (n = 4) were used for controls. At 7-week postoperative, 3DµCT and histological analyses were performed. RESULTS: On 3DµCT images, increased disc height and endplate irregularities at the L4-5 segment and decreased disc height at adjacent segments were observed in the Experimental group. Histological scores were also higher in the Experimental group than the Sham Group. CONCLUSIONS: Degenerative changes were observed at the facetectomy level. These may correspond with the previously reported delayed gait disturbance after facetectomy. This animal model may be useful to create mechanically induced disc degeneration without direct tissue damage to the disc.

[Current Status of Thoracic Endovascular Aortic Repair in Our Institution].

Within 8-year period between 2009 and 2016, we treated 215 patient with a strategy of primary thoracic endovascular aortic repair( TEVAR). In-hospital mortality was 4.4%( 8 cases). Thirty-two emergency cases was included and we treated 23 cases of zone 0 debranching TEVAR with chimney techinique in this period. In recent 2-year period between 2015 and 2016, we treated 44 cases of TEVAR without type I a endoleaks with 0% mortality(most of the them was zone 2~3 TEVAR in this period) on the one hand, and the number of open surgery for thoracic aorta was 80 on the other. TEVAR was also indicated for emergency and high risk cases even if their anatomical conditions were outside of instruction for use, and utilized for bridging or staged therapy for open surgery in our series. Standardization and refinement of endovascular procedures is considered to be important to improvement outcomes, and hybrid therapy or back up of open surgery should be collaborated with TEVAR for thoracic aortic aneurysm treatment.

A soluble envelope protein of endogenous retrovirus (FeLIX) present in serum of domestic cats mediates infection of a pathogenic variant of feline leukemia virus.

T-lymphotropic feline leukemia virus (FeLV-T), a highly pathogenic variant of FeLV, induces severe immunosuppression in cats. FeLV-T is fusion defective because in its PHQ motif, a gammaretroviral consensus motif in the N terminus of an envelope protein, histidine is replaced with aspartate. Infection by FeLV-T requires FeLIX, a truncated envelope protein encoded by an endogenous FeLV, for transactivation of infectivity and Pit1 for binding FeLIX. Although Pit1 is present in most tissues in cats, the expression of FeLIX is limited to certain cells in lymphoid organs. Therefore, the host cell range of FeLV-T was thought to be restricted to cells expressing FeLIX. However, because FeLIX is a soluble factor and is expressed constitutively in lymphoid organs, we presumed it to be present in blood and evaluated its activities in sera of various mammalian species using a pseudotype assay. We demonstrated that cat serum has FeLIX activity at a functional level, suggesting that FeLIX is present in the blood and that FeLV-T may be able to infect cells expressing Pit1 regardless of the expression of FeLIX in vivo. In addition, FeLIX activities in sera were detected only in domestic cats and not in other feline species tested. To our knowledge, this is the first report to prove that a large amount of truncated envelope protein of endogenous retrovirus is circulating in the blood to facilitate the infection of a pathogenic exogenous retrovirus.

Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations.

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17ß and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17ß, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17ß after copulation.

Gait abnormality due to spinal instability after lumbar facetectomy in the rat.

PURPOSE: Spinal instability of the lumbar spine causes various clinical symptoms. Among them, spinal instability is thought to contribute to low back pain, but the pathophysiological mechanisms are controversial. Although experimental animal models of spinal instability have been reported, it is unknown whether these models produce pain and whether spinal instability affects walking ability. We used the CatWalk system to investigate whether lumbar facetectomy causes gait abnormalities and low back pain. METHODS: Thirty male Sprague-Dawley rats were divided into three experimental groups. In the sham group, only the bilateral L4-L5 facet joints were exposed. In the experimental group, rats underwent complete resection of the bilateral L4-L5 facet joints without neural tissue injury. The control group comprised naïve rats. The CatWalk system was used to analyze gait in postoperative weeks 3, 4.5, 6, and 7. Radiological and histological analyses were also performed. RESULTS: At 7 weeks postoperatively, the rats in the experimental group showed the gait abnormalities seen in low back pain and neuropathic pain models. Radiological examination of the same rats revealed spinal instability with histological evidence of intervertebral disc degeneration. CONCLUSIONS: These results suggest that spinal instability and/or intervertebral disc degeneration induce gait abnormalities and low back pain. This experimental model may be useful for elucidating the mechanisms underlying clinical symptoms, such as low back pain, in patients with spinal instability.

Molecular phylogeography of the brown bear (Ursus arctos) in Northeastern Asia based on analyses of complete mitochondrial DNA sequences.

To further elucidate the migration history of the brown bears (Ursus arctos) on Hokkaido Island, Japan, we analyzed the complete mitochondrial DNA (mtDNA) sequences of 35 brown bears from Hokkaido, the southern Kuril Islands (Etorofu and Kunashiri), Sakhalin Island, and the Eurasian Continent (continental Russia, Bulgaria, and Tibet), and those of four polar bears. Based on these sequences, we reconstructed the maternal phylogeny of the brown bear and estimated divergence times to investigate the timing of brown bear migrations, especially in northeastern Eurasia. Our gene tree showed the mtDNA haplotypes of all 73 brown and polar bears to be divided into eight divergent lineages. The brown bear on Hokkaido was divided into three lineages (central, eastern, and southern). The Sakhalin brown bear grouped with eastern European and western Alaskan brown bears. Etorofu and Kunashiri brown bears were closely related to eastern Hokkaido brown bears and could have diverged from the eastern Hokkaido lineage after formation of the channel between Hokkaido and the southern Kuril Islands. Tibetan brown bears diverged early in the eastern lineage. Southern Hokkaido brown bears were closely related to North American brown bears.