Abstract Tree-ring cellulose oxygen isotopic ratios have been widely studied as a hydrological proxy in monsoonal Asia. There has been, however, little attempt to perform proxy assessment of the intra-annual isotopic data to reconstruct hydroclimate with higher temporal resolution. We presented new intra-annual cellulose oxygen isotopic records of Japanese cedar trees spanning A.D. 1918 to 2017, and validated it as a hydrological proxy by comparing with meteorological data. There are significant negative correlations between intra-annual isotopic ratios and summer precipitation/relative humidity, as similar to annual-resolution data of earlier studies. Notably on intra-annual scales, the period showing the highest correlation gradually shifted from May to August, in corresponding to the location within the annual ring. Principal component regression analyses show the regression was more accurate over a wider duration than single regression analysis using the annual data, therefore indicating that the subdivision of the annual ring could contribute to reconstruct higher-resolution hydroclimate.
A retrospective multicenter study of series of 20 patients with myxopapillary ependymomas, which underwent surgery. OBJECTIVE.: To evaluate the postoperative outcomes of patients surgically treated for spinal myxopapillary ependymoma. Neurologic deterioration after tumor resection is discussed in terms of the tumor encapsulation. SUMMARY OF BACKGROUND DATA.: Myxopapillary ependymomas occur most commonly in the cauda equina and/or conus medullaris region. Most series published in the literature have covered postoperative tumor recurrence and role of adjuvant radiotherapy. Few contradistinctive studies in postoperative neurological deficit were reviewed from the standpoints of MRI and histopathologic findings.A total of 20 patients were recruited and charts, MRI, intraoperative findings, and pathologic findings were reviewed. The follow-up period ranged from 2 to 12 years (median, 72.9 months). The surgical procedures were defined as gross total removal, piecemeal total removal, and subtotal removal. Postoperative radiotherapy was given in 3 patients in whom removal had been subtotal.Gross total removal was achieved in 14 patients, piecemeal gross total and subtotal removal in 3 patients each. Neurologic deterioration after surgery was seen in 5 patients, all of which were unencapsulated tumors consisting of piecemeal gross total removal in 2 patients and subtotal removal in 3 patients. Recovery of postoperative bladder dysfunction remained unchanged in 2 patients. There were no tumor recurrence and progression of the remaining tumors. Unencapsulated tumors were more frequently seen in heterogeneously enhanced tumors on MRI than in homogenously enhanced tumors with significant difference.In the unencapsulated ependymomas, tumor separation and manipulation of the surrounding neural tissue caused neurologic injury. The heterogeneously enhanced ependymoma not only should be evaluated and treated meticulously, but also surgeons should not stick to total removal in infiltrated and adhering tumors as subtotally resected tumors with postoperative radiotherapy have not always recurred.
Abstract Attenuation of the secondary injury of spinal cord injury (SCI) can suppress the spread of spinal cord tissue damage, possibly resulting in spinal cord sparing that can improve functional prognoses. Granulocyte colony-stimulating factor (G-CSF) is a haematological cytokine commonly used to treat neutropenia. Previous reports have shown that G-CSF promotes functional recovery in rodent models of SCI. Based on preclinical results, we conducted early phase clinical trials, showing safety/feasibility and suggestive efficacy. These lines of evidence demonstrate that G-CSF might have therapeutic benefits for acute SCI in humans. To confirm this efficacy and to obtain strong evidence for pharmaceutical approval of G-CSF therapy for SCI, we conducted a phase 3 clinical trial designed as a prospective, randomized, double-blinded and placebo-controlled comparative trial. The current trial included cervical SCI [severity of American Spinal Injury Association (ASIA) Impairment Scale (AIS) B or C] within 48 h after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group was administered 400 μg/m2/day × 5 days of G-CSF in normal saline via intravenous infusion for five consecutive days. The placebo group was similarly administered a placebo. Allocation was concealed between blinded evaluators of efficacy/safety and those for laboratory data, as G-CSF markedly increases white blood cell counts that can reveal patient treatment. Efficacy and safety were evaluated by blinded observer. Our primary end point was changes in ASIA motor scores from baseline to 3 months after drug administration. Each group includes 44 patients (88 total patients). Our protocol was approved by the Pharmaceuticals and Medical Device Agency in Japan and this trial is funded by the Center for Clinical Trials, Japan Medical Association. There was no significant difference in the primary end point between the G-CSF and the placebo control groups. In contrast, one of the secondary end points showed that the ASIA motor score 6 months (P = 0.062) and 1 year (P = 0.073) after drug administration tend to be higher in the G-CSF group compared with the placebo control group. The present trial failed to show a significant effect of G-CSF in primary end point.
Retrospective clinical study.To investigate adjacent segment degeneration (ASD) at 5 years after L4/5 posterior lumbar interbody fusion with pedicle screw instrumentation and L4/5 decompression surgery using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI), with the evaluation of annual changes on MRI.Methods of evaluation have been inconsistent among studies of ASD. There is no report that ASD in the lumbar spine after posterior lumbar interbody fusion at the same level is thoroughly evaluated on radiographs, CT, annual MRI changes, and the impact of decompression procedures.ASD was evaluated in 52 patients. Disk height, vertebral slip, intervertebral angle, and intervertebral range of motion were examined on plain radiographs. Facet joint degeneration on CT and disk degradation and spinal stenosis on MRI were classified into categories, and facet sagittalization and tropism were measured on CT. The incidence of ASD was compared between the decompression procedures.The radiographic changes observed in the study were defined as radiographic ASD (R-ASD) without reoperation, as no patient required reoperation. R-ASD was rarely detected by radiography. The incidences of facet joint degeneration, MRI-detected disk degeneration, and spinal stenosis at the L3/4 and L5/S1 levels were 21% and 23%, 27% and 17%, and 35% and 4%, respectively. Progressive disk degeneration at L3/4 was found significantly more frequently in patients with aggravation of facet degeneration (P<0.01); however, the severities of preoperative facet degeneration, facet sagittalization, and tropism were not associated with progressive disk degeneration or spinal stenosis. In annual MRI, most R-ASD cases were detected within 3 years after surgery. Patients who underwent L4 total laminectomy had significantly more frequent R-ASD compared with those who received bilateral fenestration at L4/5 (P<0.01).R-ASD was detected more frequently by CT and MRI compared with radiography. Preoperative facet joint degeneration and morphology were not always related to progressive disk degeneration or spinal stenosis. Annual MRI suggested that accelerated degeneration was due to lumbar spine fusion, rather than aging degeneration. Decompression with preservation of posterior connective components is recommended to prevent R-ASD.
Retrospective clinical study.To evaluate the accuracy of computer-assisted surgery for idiopathic scoliosis.Segmental pedicle screw fixation has been proven to enable enhanced correction of scoliotic deformities. However, both neurovascular and visceral structures are at potential risk from screw misplacement due to pedicle drift. No reports exist on the accuracy and benefits of computer-assisted surgery for pedicle screwing in scoliosis surgery.A total of 40 consecutive patients with idiopathic scoliosis were evaluated. Postoperative computed tomography was assessed for the accuracy of pedicle screw placement in 20 cases treated without a navigation system and 20 cases with a computed tomography-based navigation system. Correlations between registered levels and pedicle perforation were investigated.Pedicle violation was observed in 28.0% of the control group and 11.4% of the navigation group, with significant differences. No screw misplacements at the registered levels were seen, and the longer the distance between the registered level and level of screw insertion, the higher the rate of pedicle violation. No intraoperative complications caused by pedicle perforation occurred.In the navigation group, a tendency to lateral perforation at the concave side and medial perforation at the convex side was noted, like in the control group. Use of the navigation system significantly reduced the screw misplacement rate for rotated vertebrae as compared with the control group. Separate registration is recommended for rotated vertebrae when possible.
