Effects of Arterial Stiffness on Cerebral WM Integrity in Older Adults: A Neurite Orientation Dispersion and Density Imaging and Magnetization Transfer Saturation Imaging Study

BACKGROUND AND PURPOSE

Arterial stiffness is reported to be able to cause axonal demyelination or degeneration. The present study aimed to use advanced MR imaging techniques to examine the effect of arterial stiffness on the WM microstructure among older adults.

MATERIALS AND METHODS

Arterial stiffness was measured using the cardio-ankle vascular elasticity index (CAVI). The high-CAVI (mean CAVI ≥ 9 points) and the low-CAVI groups (mean CAVI < 9 points) were created. The neuronal fiber integrity of the WM was evaluated by neurite orientation dispersion and density imaging and magnetization transfer saturation imaging. Tract-Based Spatial Statistics and the tracts-of-interest analysis were performed. Specific WM regions (corpus callosum, internal capsule, anterior thalamic radiation, corona radiata, superior longitudinal fasciculus, forceps minor, and inferior fronto-occipital fasciculus) were selected in the tracts-of-interest analysis.

RESULTS

In Tract-Based Spatial Statistics, the high-CAVI group showed a significantly lower myelin volume fraction value in the broad WM and significantly higher radial diffusivity and isotropic volume fraction values in the corpus callosum, forceps minor, inferior fronto-occipital fasciculus, internal capsule, corona radiata, and anterior thalamic radiation than the low-CAVI group. In tracts-of-interest analysis using multivariate linear regression, significant associations were found between the mean CAVI and radial diffusivity in the anterior thalamic radiation and the corona radiata; isotropic volume fraction in the anterior thalamic radiation and the corona radiata; and myelin volume fraction in the superior longitudinal fasciculus (P < .05). Additionally, partial correlation coefficients were observed for the significant associations of executive function with radial diffusivity and myelin volume fraction (P < .05).

CONCLUSIONS

Arterial stiffness could be associated with demyelination rather than axonal degeneration.

Evaluation of distinct modes of oxidative secondary injury generated in heat-treated cells of Escherichia coli with solid/liquid and complex/semi-synthetic media sets

AIMS

To characterize and evaluate oxidative secondary injury generated in heat-treated Escherichia coli cells during recovery cultivation either on agar or in a broth of a semi-synthetic enriched M9 (EM9) medium and a complex Luria broth (LB) medium with different types of antioxidants.

METHODS AND RESULTS

E. coli cells grown in the EM9 and LB broth were heated at 50^o C in a buffer (pH7.0). Heated cells were recovered on the same kind of agar medium as that used for growth, with or without different antioxidants. Although these antioxidants mostly protected the cells from oxidative secondary injury on the recovery media, sodium thiosulfate and sodium pyruvate were most protective on EM9 and LB agars, respectively. Determination of viability using the most probable number and growth delay analysis methods showed significant reductions in the protective effects of antioxidants in the EM9 and LB media.

CONCLUSION

Oxidative secondary injury generated in heated E. coli cells was found to be qualitatively and quantitatively diverse under cellular and environmental conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results suggest that different modes of oxidation should be considered in viability determination and injured cell enumeration of heat-treated cells.

A Rare Case of Completely Calcified Lumber Juxta-facet Cyst: A Case Report

Introduction: Juxta-facet cysts (JFCs) are extradural lesions. Calcification of cyst walls is often reported, although completely calcified facet cysts are extremely rare. Case Presentation: A 65-year-old man presented with a 1-year history of the right lower extremity weakness and pain, and chronic low back pain. Imaging showed hypointensity on T1- and T2-weighted magnetic resonance images which can be very well appreciated on a completely calcified computed tomography mass arising from the right L3/4 facet joint. The patient underwent a total cyst removal with a facetectomy of the right L3/4 facet, and L3 to L4 posterior fusion. Conclusion: We presented a case of a completely calcified JFC in a patient with back pain and radiculopathy who underwent cystectomy and spinal fusion. JFCs should be considered in the differential diagnosis of calcified extradural lesions.

An Investigation of Water Diffusivity Changes along the Perivascular Space in Elderly Subjects with Hypertension

BACKGROUND AND PURPOSE

Hypertension may be related to alterations of the glymphatic system, a waste metabolite drainage system in the brain. We aimed to investigate analysis along the perivascular space index changes in elderly subjects with hypertension.

MATERIALS AND METHODS

Diffusion-weighted images were acquired from 126 subjects, including 63 subjects with hypertension (25 men and 38 women; mean age, 72.45 years) and 63 age- and sex-matched controls (25 men and 38 women; mean age, 72.16 years). We calculated the analysis along the perivascular space index as a ratio of the mean of x-axis diffusivities in the projection and association areas to the mean of y-axis diffusivity in the projection area and z-axis diffusivity in the association area. The left, right, and mean analysis along the perivascular space indices of both hemispheres were compared between the hypertension and control groups using a Mann-Whitney U test. The Spearman correlation coefficient was used to assess the correlation between the left, right, and mean ALPS indices and blood pressure and pulse pressure.

RESULTS

The left (P = .011) and mean (P = .024) analysis along the perivascular space indices of the hypertension group were significantly lower than that of the control group. The left, right, and mean analysis along the perivascular space indices of all subjects were significantly negatively correlated with blood pressure values (r = -0.200 to -0.278, P = .002-0.046) and pulse pressure values (r = -0.221 to -0.245, P = .006-0.013).

CONCLUSIONS

Our results are consistent with a model in which hypertension causes glymphatic dysfunction.

Relationship between Preoperative Neuroradiological Findings and Intraoperative Bulbocavernosus Reflex Amplitude in Patients with Intradural Extramedullary Tumors

The current study aimed to evaluate the relationship between preoperative neuroradiological findings and intraoperative bulbocavernosus reflex (BCR) amplitude in patients with intradural extramedullary tumors. A total of 24 patients with lesions below the 12th thoracic vertebra were included in the analysis. Objective and subjective urinary symptoms were investigated using data obtained from medical records and the core lower urethral symptom score (CLSS) questionnaire. The lesion compression rate was evaluated with MRI. In the epiconus-to-conus medullaris (Epi-CM) group, BCR amplitude changes were found to be correlated with the compression rate (p <0.05). The preoperative CLSS of the group with a BCR amplitude of <50% was worse than that of the group with ≥50% (p <0.01). The group did not experience symptom improvement 6 months postoperatively based on the CLSS. The preoperative CLSS of the group with compression rate of ≥80% on imaging was worse than that of the group with <80% (p <0.05). In the group with preoperative compression rate of ≥80%, CLSS at 1 month and 6 months postoperatively was improved as compared to preoperative CLSS (p <0.01, p <0.05). Hence, BCR amplitude changes are associated with the degree of lesion compression on preoperative images and pre- and postoperative urinary symptoms. Patients with intradural extramedullary Epi-CM lesions with strong compression are likely to present with low BCR amplitude and worsened postoperative symptoms. It is considered that the risk of postoperative urinary symptoms increases even with careful surgical manipulation under these conditions.

Effects of Rice Wine Lees on Cognitive Function in Community-Dwelling Physically Active Older Adults: A Pilot Randomized Controlled Trial

BACKGROUND

Rice wine lees (RWL), a Japanese traditional fermented product, is a rich source of one-carbon metabolism-related nutrients, which may have beneficial effects on cognitive function.

OBJECTIVES

We aimed to examine the effect of the RWL on cognitive function in community-dwelling physically active older adults.

DESIGN

Double-blind, randomized, placebo-controlled study (clinical trial number: UMIN 000027158).

SETTING

Community-based intervention including assessments conducted at the University of Hyogo and a public liberal arts school in Himeji City, Japan.

PARTICIPANTS

A total of 35 community-dwelling older adults (68-80 years) who performed mild exercise before and during the trial were assigned to either the RWL (n=17) or the placebo group (n=18).

INTERVENTION

Daily consumption of 50 g RWL powder, which contained one-carbon metabolism-related nutrients, or the placebo powder (made from soy protein and dextrin) for 12 weeks. Both supplements included equivalent amounts of energy and protein.

MEASUREMENTS

Montreal Cognitive Assessment, computerized cognitive function test, and measurements of serum predictive biomarkers (transthyretin, apolipoprotein A1, and complement C3) were conducted at baseline and follow-up.

RESULTS

Visual selective attention and serum transthyretin significantly improved in the RWL group, whereas there was no significant change in the placebo group. No significant group difference was observed in the remaining cognitive performance tests.

CONCLUSIONS

RWL supplements seem to have a few effects on cognitive function in community-dwelling physically active older adults. However, the impact was limited; therefore, further studies with sufficient sample size are warranted to elucidate this issue.

Acromegaly presenting with myelopathy due to ossification of posterior longitudinal ligament: a case report

Background

Acromegaly is a rare disease caused by high serum levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), often originating from a pituitary adenoma. Spinal and peripheral joint abnormalities are caused by these hormonal hypersecretions. In particular, the response to GH is involved in the onset of ossification of the spinal ligament in vitro, especially ossification of the posterior longitudinal ligament (OPLL). However, because acromegaly and OPLL are rare diseases, we seldom encounter them in combination. To the best of our knowledge in the English-language literature, this is the first reported case of acromegaly presenting with thoracic myelopathy due to OPLL.

Case presentation

A 47-year-old woman presented with lower extremity weakness and paresthesia, gait disorder, and bladder disorder without any trauma. The patient’s most remarkable symptom was paraplegia, and we diagnosed myelopathy due to cervical and thoracic OPLL. Furthermore, we suspected acromegaly because of the characteristic facial features, and we found a pituitary adenoma by contrast-enhanced MRI. Cervical and thoracic decompression, posterior fixation, and pituitary adenoma resection were performed.

Conclusion

We report a case of acromegaly that was detected after the diagnosis of OPLL. The main challenge in acromegaly is delayed in diagnosis. Even in this case, the facial features characteristic of acromegaly had appeared at least 9 years ago. Early diagnosis and treatment of acromegaly improve prognosis and reduce exposure to GH and IGF-1 through early intervention and seem to suppress the progression of ligament ossification. Orthopedic surgeons and neurosurgeons need to keep in mind that acromegaly is associated with bone/joint lesions and ossification of the spinal ligament and should aim to diagnose acromegaly early.

Adult Morquio syndrome requiring occipito-thoracic fusion

Morquio syndrome is a relatively rare entity that is often associated with atlantoaxial instability from early childhood due to odontoid dysplasia based on a mucopolysaccharoidal disorder. Here, we present the case of a 55-year-old male patient with Morquio syndrome who developed cervical myelopathy, which is an extremely rare condition in the older population. Myelopathy developed gradually with upper-limb paresthesia and clumsiness of both hands. The patient had a characteristic "gargoyle-like" coarse face with a trunk shortening-type short stature. Imaging of the cervical spine demonstrated several problems, including diminutive structures called platyspondyly with small pedicles and fragile bone quality, hypoplasia of the C1 posterior arch that migrated into the spinal canal, and os odontoideum with atlantoaxial instability. With intraoperative navigation guidance, posterior decompression of C1 followed by occipito-cervico-thoracic spinal fusion was successfully performed in this complicated case. Clinical and radiographic outcomes were both excellent and have been maintained for 2 years postoperatively.

Sharp systolic blood pressure elevation at extubation is a risk factor for symptomatic epidural hematoma after spine surgery

STUDY DESIGN

The present study is a single-center retrospective cohort study.

OBJECTIVE

The objective of the study is to verify the hypothesis that sharp elevation of systolic blood pressure at extubation is a risk factor for development of symptomatic epidural hematoma after spinal surgery.

SUMMARY OF BACKGROUND DATA

Postoperative symptomatic epidural hematoma (she) after spine surgery is a rare but potentially serious complication that may result in paralysis unless removed at an early stage.

METHODS

The subjects were 2611 patients treated with decompression and decompression/fusion of the cervical, thoracic, and lumbar vertebrae at our hospital. Twelve of these patients developed postoperative SEH and removal of hematoma was performed. To investigate the risk factors in these patients, data were analyzed for age at the time of surgery, sex, preoperative complications, medical history, body mass index, preoperative platelet count, surgical procedure, microscope use, operative time, blood loss, surgical site, systolic blood pressure (SBP) at extubation, difference between resting and extubation SBP, ratio of SBP at extubation to that at rest, blood pressure at discharge from the operating room, and use of a drain.

RESULTS

There was a significantly higher rate of SBP ratio (extubation/rest) ≥1.3 in patients with SEH (p = 0.021, Fisher's exact test). Among the preoperative complications and medical histories, the frequency of cerebrovascular disorder tended to be higher in SEH cases than in non-SEH cases (p = 0.073). There was no significant difference for all other parameters listed above. In multivariate logistic analysis, the odds ratios were 3.98 (p = 0.018) for an SBP ratio (extubation/rest) ≥1.3 and 4.75 (p = 0.055) for cerebrovascular disorder, suggesting effects of these two items. With simultaneous input into a multivariate model, SBP ratio ≥1.3 had a significant independent association with postoperative SEH (p = 0.021) and cerebrovascular disorder showed a tendency for this association (p = 0.072).

CONCLUSION

The risk for symptomatic epidural hematoma is significant in patients with SBP at extubation that is more than 1.3 times that of SBP at rest.

Overview of dropped head syndrome (Combined survey report of three facilities)

BACKGROUND

Dropped head syndrome (DHS) is a low prevalence and the clinical features remain unclear. The purpose of the present study was to clarify the general overview of DHS.

METHODS

The subjects were 67 consecutive DHS patients (17 men and 50 women; average age 72.9 ± 10.2 years) presenting difficulty of horizontal gaze in up-right position. The patients' background, global spinal alignment, clinical findings and treatment were analyzed.

RESULTS

The peak population of DHS was 75-79-year-old females. The comorbidities included Parkinson's disease in 9 cases, minor trauma in 9 cases, post-cervical operation in 3 cases, mental depression in 3 cases, malignant tumor in 3 cases, diabetes mellitus in 2 cases and rheumatoid arthritis in 2 cases. The C2-C7 cervical coronal vertical axis was distributed more to the right side (2.6 ± 12.8 mm). Regarding sagittal alignment, 24 cases (35.8%) showed negative balanced DHS (N-DHS) and 43 cases (64.2%) showed positive balanced DHS (P-DHS). There were significant differences in C2-C7 angle, T1S, LL and PI-LL between the two groups. Cervical or back pain was present in 62 cases (92.5%), and average numerical rating scale was 3.0 ± 2.6. Fourteen cases (20.9%) recovered (average 11.3 months), but 29 cases (43.3%) did not recover without surgery. Twenty-four cases (35.8%) underwent surgery, 20 for cervical spine and 4 for thoraco-lumbar spine, and horizontal gaze difficulty was improved in all patients post-surgery.

CONCLUSION

DHS was mainly observed in elderly women. About 20% of DHS patients recovered without surgical treatment. DHS was accompanied by scoliosis in 37.3% of the cases.

White Matter Abnormalities in Multiple Sclerosis Evaluated by Quantitative Synthetic MRI, Diffusion Tensor Imaging, and Neurite Orientation Dispersion and Density Imaging

BACKGROUND AND PURPOSE

A number of MR-derived quantitative metrics have been suggested to assess the pathophysiology of MS, but the reports about combined analyses of these metrics are scarce. Our aim was to assess the spatial distribution of parameters for white matter myelin and axon integrity in patients with relapsing-remitting MS by multiparametric MR imaging.

MATERIALS AND METHODS

Twenty-four patients with relapsing-remitting MS and 24 age- and sex-matched controls were prospectively scanned by quantitative synthetic and 2-shell diffusion MR imaging. Synthetic MR imaging data were used to retrieve relaxometry parameters (R1 and R2 relaxation rates and proton density) and myelin volume fraction. Diffusion tensor metrics (fractional anisotropy and mean, axial, and radial diffusivity) and neurite orientation and dispersion index metrics (intracellular volume fraction, isotropic volume fraction, and orientation dispersion index) were retrieved from diffusion MR imaging data. These data were analyzed using Tract-Based Spatial Statistics.

RESULTS

Patients with MS showed significantly lower fractional anisotropy and myelin volume fraction and higher isotropic volume fraction in widespread white matter areas. Areas with different isotropic volume fractions were included within areas with lower fractional anisotropy. Myelin volume fraction showed no significant difference in some areas with significantly decreased fractional anisotropy in MS, including in the genu of the corpus callosum and bilateral anterior corona radiata, whereas myelin volume fraction was significantly decreased in some areas where fractional anisotropy showed no significant difference, including the bilateral posterior limb of the internal capsule, external capsule, sagittal striatum, fornix, and uncinate fasciculus.

CONCLUSIONS

We found differences in spatial distribution of abnormality in fractional anisotropy, isotropic volume fraction, and myelin volume fraction distribution in MS, which might be useful for characterizing white matter in patients with MS.

Effect of Gadolinium on the Estimation of Myelin and Brain Tissue Volumes Based on Quantitative Synthetic MRI

BACKGROUND AND PURPOSE

The effect of gadolinium on the estimation of myelin has not been reported. The aim of the current study was to investigate the effects of gadolinium on automatic myelin and brain tissue volumetry via quantitative synthetic MR imaging.

MATERIALS AND METHODS

The study included 36 patients who were referred for brain metastases screening, and quantitative synthetic MR imaging data before and after gadolinium-based contrast agent administration were analyzed retrospectively. Brain metastases were detected in 17 patients. WM volume, GM volume, CSF volume, non-WM/GM/CSF volume, myelin volume, brain parenchymal volume, myelin fraction (myelin volume/brain parenchymal volume), and intracranial volume were estimated. T1 and T2 relaxation times, proton density, and myelin partial volume per voxel averaged across the brain parenchyma were also analyzed.

RESULTS

In patients with and without metastases after gadolinium-based contrast agent administration, measurements of WM and myelin volumes, and myelin fraction were significantly increased (+26.65 and +29.42 mL, +10.14 and +12.46 mL, +0.88% and +1.09%, respectively), whereas measurements of GM, CSF, brain parenchymal, and intracranial volumes were significantly decreased (-36.23 and -34.49 mL, -20.77 and -18.94 mL, -6.76 and -2.84 mL, -27.41 and -21.84 mL, respectively). Non-WM/GM/CSF volume did not show a significant change. T1, T2, and proton density were significantly decreased (-51.34 and -46.84 ms, -2.67 and -4.70 ms, -1.05%, and -1.28%, respectively) after gadolinium-based contrast agent administration, whereas measurements of myelin partial volume were significantly increased (+0.78% and +0.75%, respectively).

CONCLUSIONS

Gadolinium had a significant effect on the automatic calculation of myelin and brain tissue volumes using quantitative synthetic MR imaging, which can be explained by decreases in T1, T2, and proton density.

Improving the Quality of Synthetic FLAIR Images with Deep Learning Using a Conditional Generative Adversarial Network for Pixel-by-Pixel Image Translation

BACKGROUND AND PURPOSE

Synthetic FLAIR images are of lower quality than conventional FLAIR images. Here, we aimed to improve the synthetic FLAIR image quality using deep learning with pixel-by-pixel translation through conditional generative adversarial network training.

MATERIALS AND METHODS

Forty patients with MS were prospectively included and scanned (3T) to acquire synthetic MR imaging and conventional FLAIR images. Synthetic FLAIR images were created with the SyMRI software. Acquired data were divided into 30 training and 10 test datasets. A conditional generative adversarial network was trained to generate improved FLAIR images from raw synthetic MR imaging data using conventional FLAIR images as targets. The peak signal-to-noise ratio, normalized root mean square error, and the Dice index of MS lesion maps were calculated for synthetic and deep learning FLAIR images against conventional FLAIR images, respectively. Lesion conspicuity and the existence of artifacts were visually assessed.

RESULTS

The peak signal-to-noise ratio and normalized root mean square error were significantly higher and lower, respectively, in generated-versus-synthetic FLAIR images in aggregate intracranial tissues and all tissue segments (all P < .001). The Dice index of lesion maps and visual lesion conspicuity were comparable between generated and synthetic FLAIR images (P = 1 and .59, respectively). Generated FLAIR images showed fewer granular artifacts (P = .003) and swelling artifacts (in all cases) than synthetic FLAIR images.

CONCLUSIONS

Using deep learning, we improved the synthetic FLAIR image quality by generating FLAIR images that have contrast closer to that of conventional FLAIR images and fewer granular and swelling artifacts, while preserving the lesion contrast.

Use of intrawound vancomycin powder against postoperative infection after spine surgery

Local application of vancomycin has recently become widely used in spine surgery. However, local application is not included in the indication and has not been approved by the US Food and Drug Administration (FDA). Thus, we searched for reports with "intra wound-vancomycin" and "SSI" as keywords in the MEDLINE database, and investigated the efficacy, problems with use, and future prospects based on these reports. Intrawound vancomycin was described as effective in most of the reports, but was found to have no effect or to aggravate the condition in some reports. A toxic effect on osteoblasts due to a high local concentration was described in some reports, whereas local application was found to be safe in other studies. The amount of vancomycin used and the administration method varied among the reports. Overall, the results suggest that intrawound vancomycin is clinically effective, but this has yet to be established in a randomized controlled trial. There is a need to identify cases that should be selected for this treatment and to investigate the dose and optimum concentration of vancomycin for clinical use.

Solitary Spinal Epidural Metastasis from Gastric Cancer

Solitary epidural space metastasis of a malignant tumor is rare. We encountered a 79-year-old male patient with solitary metastatic epidural tumor who developed paraplegia and dysuria. The patient had undergone total gastrectomy for gastric cancer followed by chemotherapy 8 months priorly. The whole body was examined for suspected metastatic spinal tumor, but no metastases of the spine or important organs were observed, and a solitary mass was present in the thoracic spinal epidural space. The mass was excised for diagnosis and treatment and was histopathologically diagnosed as metastasis from gastric cancer. No solitary metastatic epidural tumor from gastric cancer has been reported in English. Among the Japanese, 3 cases have been reported, in which the outcome was poor in all cases and no definite diagnosis could be made before surgery in any case. Our patient developed concomitant pneumonia after surgery and died shortly after the surgery. When a patient has a past medical history of malignant tumor, the possibility of a solitary metastatic tumor in the epidural space should be considered.

Ipragliflozin as an Initial Therapy in Drug Naïve Subjects with Type 2 Diabetes

OBJECTIVES

The aim of this study is to investigate ipragliflozin as an initial type 2 diabetes (T2DM) drug.

METHODS

Ipragliflozin 25-50 mg/day monotherapy was performed with drug naïve subjects with T2DM (n=31). As a comparator, 12.5-25 mg/day alogliptin monotherapy was undertaken (n=32). At 3 months, levels of metabolic parameters were compared with those at baseline.

FINDINGS

4 subjects discontinued ipragliflozin due to intolerance or adverse events, while none dropped out with alogliptin. At 3 months, similar decreases of HbA1c levels were observed with these 2 drugs (10.21-8.31%, p<0.00001, with ipragliflozin, and 10.08-8.25%, p<0.00001, with alogliptin), however fasting blood glucose (FBG) levels decreased with significant inter-group differences (- 23.5% with iprgliflozin and - 10.8% with alogliptin). While similar increases of homeostasis model assessment (HOMA)-B levels were observed with these 2 drugs, HOMA-R levels significantly decreased only with ipragliflozin (-19.4%, p<0.02). Un-correlative link between HOMA-R and HOMA-B levels at baseline became significantly correlative (R=0.6017, p<0.001) only with ipragliflozin. Significant reductions of body mass index (BMI, -2.6%, P<0.05) were observed with ipragliflozin, however, no correlations between the changes of BMI and those of HbA1c or FBG were noted.

CONCLUSIONS

These results suggest that ipragliflozin has good glycemic efficacy as an initial therapy in subjects with T2DM, although certain adverse events or tolerability issues are concerned. It improves insulin sensitivity and may restore the impaired beta-cell function. However body weight reduction with ipragliflozin is not associated with its glycemic efficacy.

Evaluation of antimicrobial prophylaxis against postoperative infection after spine surgery: Limit of the first generation cephem

In our department, first-generation cephem (CEZ) are generally administered for 2 days as antimicrobial prophylaxis (AMP) for spinal surgery. However, the incidence of surgical site infection (SSI) has recently increased, particularly cases involving coagulase-negative Staphylococci (CNS) as an etiologic agent. The objective was to elucidate the problems with the current AMP and the risk factors of SSI through a retrospective investigation of affected cases. The subjects were patients who underwent spine surgery at our department between August 2007 and June 2013. The subjects were divided into those who developed SSI (S group) and who did not develop SSI (non-SSI (N) group), patients who developed CNS infection in the S group was subdivided as C group, and the risk factors were investigated. The significance of each factor was analyzed using cross tabulation, and multivariate logistic regression analyses were performed with 22 of the investigation factors as explanatory variables. The incidence of SSI was 2.55%, and the etiologic agent was CNS in 17 patients. Upon comparison between the S and N groups, the presence of 3 or more underlying diseases and blood loss were extracted as significant risk factors. Upon comparison between the C and N groups, emergency surgery and intra- and postoperative steroid administration were extracted as significant risk factors, in addition to the presence of 3 or more underlying diseases and blood loss. The effect of the current AMP using first generation cephem is limited, and reconsideration of the protocol may be necessary.

Investigation of ossification in the posterior longitudinal ligament using micro-focus X-ray CT scanning and histological examination

BACKGROUND

Ossification in the posterior longitudinal ligament (PLL) correlates with changes of enthesis during the early stages of development, but this issue remains controversial, as little is known regarding the details of this process. The aim of the present study was to elucidate part of the ossification mechanism. Thus, in the present study, we observed and evaluated minute ossifications in the PLL that did not exhibit symptoms of ossification of the posterior longitudinal ligament (OPLL).

METHODS

The subjects in the present study were derived from serial autopsy cases from January 2009 to December 2013 at Toho University Omori Medical Center, Japan. Minute ossifications in the PLL from autopsy subjects without any history of OPLL were screened as high-density areas using micro-focus X-ray CT, and the foci were histologically examined. Subsequently, we conducted both micro-focus X-ray CT image analysis and histological examination, and evaluated the correlation between these findings and putative predictive factors reported in previous studies.

RESULTS

A total of 103 individuals among the 267 subjects involved in the present study were analyzed within the study period. There were no cases involving OPLL identification prior to death, and no subjects presented with neurological symptoms of myelopathy. The incidence of cases involving high-density areas greater than 0.1 mm(2) in the PLL was 46.6 %, half of which revealed mature bone structures inside this area. Thus, the high-density areas comprised three types: a continuous posterior-annular fibrosus type (23 cases), an isolated posterior-annular fibrosus type (11 cases), and a posterior-vertebral type (29 cases). However, a positive correlation was observed between the proportion of high-density areas, age (Pearson r = 0.265, p < 0.01), and HbA1c (Pearson r = 0.294, p < 0.01). Histological examination confirmed that these high-density areas involved calcification with or without mature bone formation.

CONCLUSIONS

We evaluated minute foci of calcification with and without ossification in the PLL from 103 cadavers, generating the following observations: 1. Minute calcification foci greater than 0.1 mm(2) were observed in the PLL of 48 cases (46.6 %), half of which revealed mature bone structures inside this area (23.3 %). 2. The proportion of minute calcification foci observed in the present study was correlated with age and glucose tolerance, suggesting changes in the OPLL in the early stage. 3. Three different mechanisms of ossification were suggested: The two structures developed behind the disc might reflect the elongation of enthesis or rupture of annular fibrosus, while the remaining structure developed behind the vertebral body might reflect a dystrophic calcification-based bony metaplasia sequence.

Distinct glucose-lowering properties in good responders treated with sitagliptin and alogliptin

BACKGROUND AND OBJECTIVES

All dipeptidyl peptidase 4 (DPP-4) inhibitors display similar glycemic efficacies, although they differ greatly in their chemical structures and pharmacological properties. This may be due to the inclusions of non- or poor-responders in the analysis, thereby masking the real effects of these drugs. The aim of this study was to identify any differences in diabetic parameters only in good responders treated with sitagliptin and alogliptin.

METHODS

Treatment naïve subjects with type 2 diabetes mellitus were assigned to either sitagliptin 25-50 mg/day (n = 69) or alogliptin 12.5-25 mg/day monotherapy (n = 62) for 3 months. Only those who showed good response selected by a novel parameter called A1c index were further analysed (n = 24 for sitagliptin and n = 21 for alogliptin).

RESULTS

At baseline, FBG and BMI were significantly higher and CPR-index was significantly lower in alogliptin good responders. At 3 months, while similar reductions of HbA1c were observed in these two groups, decreases of fasting blood glucose (FBG) were significantly higher in alogliptin good responders. Homeostasis model assessment (HOMA)-R significantly decreased only in alogliptin good responders, while HOMA-B similarly and significantly increased in these two groups. BMI significantly increased only in sitagliptin good responders. Significant negative correlations were observed between A1c index and changes (Δ) of HOMA-B in both groups. By contrast, significant positive and negative correlations were observed between ΔFBG and ΔHOMA-R, and between ΔFBG and ΔHOMA-B, respectively, only in alogliptin good responders.

CONCLUSIONS

These results implicate that the effects on diabetic parameters and the glucose-lowering mechanisms of these two drugs might be different in those who have good response with these drugs. Accordingly, the choice of these drugs may be dependent on the characteristics of the patients.

Characteristics of group B Streptococcus isolated from infants with invasive infections: a population-based study in Japan

Group B Streptococcus (GBS) is one of the leading causes of neonatal bacterial infections. Population-based surveillance of GBS-related invasive diseases among newborns and infants from 10 prefectures in Japan was performed between 2007 and 2012. The characteristics of cases and isolated GBS are described in this study. The incidence rate of GBS-related invasive diseases was 0.13 per 1,000 live births. Analysis of GBS samples obtained from 60 invasive cases showed that the most frequent serotypes were III (48.3%), Ia (30.0%), and Ib (10.0%). All isolates were susceptible to penicillin G, ampicillin, cefotaxime, imipenem, and panipenem. However, 14, 2, and 7 isolates were resistant to erythromycin, clindamycin, and both erythromycin and clindamycin, respectively. Multilocus sequence typing revealed that GBS sequence type (ST) 23, ST17, and ST335 caused higher incidences of meningitis. These data show that serotypes III, Ia, and Ib together caused more than 80% of invasive infections in Japanese infants, and that GBS strains are still susceptible to β-lactam antibiotics.

Comparison of the invasiveness of conventional discectomy and microendoscopic discectomy for lumbar disc herniation: Differences in the methods of approach

INTRODUCTION

The aim of this study was to investigate whether differences in the methods of approach to the vertebral arch influence the invasiveness of conventional discectomy and microendoscopic discectomy (MED).

METHODS

In this study, 41 Wistar rats were divided into four groups: controls (no surgery) (n = 10), shams (skin incision only) (n = 11), MED (n = 10), and conventional discectomy (n = 10). We performed ethological and blood biochemical examinations for three of the groups, excluding the control group, and a histological examination for three of the groups, excluding the sham group. In the ethological examination, we measured the threshold of postoperative pain using the von Frey test. In the blood chemical examination, we measured blood creatine phosphokinase and inflammatory cytokines, and compared the severity of tissue damage by histological examination using hematoxylin-eosin and immunohistochemical staining.

RESULTS

The conventional discectomy group showed a significantly lower threshold of postoperative pain, compared with the MED group (P < 0.05). Blood biochemical investigation revealed that the creatine phosphokinase (P < 0.05) and tumor necrosis factor-α levels (P < 0.05) of the conventional discectomy group were significantly higher than those in the MED group. In the histological examination, it was found that a wide range of paraspinal muscle damage occurred in the conventional discectomy group (P < 0.05) and that the damage was mostly confined to the periosteum and nearby nerve endings.

CONCLUSION

MED was found to be less invasive than conventional discectomy based on ethological, blood biochemical, and histological examinations.

Prevalence and risk factors of nasopharyngeal carriage of Streptococcus pneumoniae in healthy children in Japan

The findings of this study revealed a 22% prevalence of Streptococcus pneumoniae among healthy children in Japan; the prevalence tended to increase with age. We identified attendance at day-care facilities and the presence of older siblings as the major risk factors associated with pneumococcal carriage. A significant decrease in pneumococcal colonization was observed among children during the summer; however, a seasonal variation was independent of various factors. Our findings suggest that prior immunization with heptavalent pneumococcal conjugate vaccine within the current recommended schedule is required for children exposed to these risk factors.

Changes in Streptococcus pneumoniae serotypes in the nasopharynx of Japanese children after inoculation with a heptavalent pneumococcal conjugate vaccine

In this study, we prospectively investigated changes in Streptococcus pneumoniae serotypes among Japanese children after heptavalent pneumococcal conjugate vaccine (PCV7) inoculation. We acquired nasopharyngeal swabs from the children at each routine PCV7 inoculation and again at least 2 months after the last PCV7 inoculation. We defined 2 periods with regard to each culture: the inoculation period as "the period of pre- or incomplete vaccination" and post-inoculation as "the period of post- or completed vaccination." The prevalence of vaccine-type (VT) pneumococci was significantly reduced from 9.5% in the inoculation-period cultures to 2.9% in the post-inoculation cultures (P < 0.01). There was no statistical difference in the prevalence of non-vaccine-type pneumococci between the inoculation-period and post-inoculation cultures (24.1% versus 23.4%). The protection of PCV7 against nasopharyngeal colonization was inferred from the decrease in VT carriage post-inoculation. The decrease in VT carriage may be conducive to reducing VT transmission within the study area.

A novel HLA-B allele, HLA-B*44:184, identified by super high-resolution single-molecule sequence-based typing in a Japanese individual

The novel allele HLA-B*44:184 differs from HLA-B*44:77 by three non-synonymous amino acid exchanges, T94I, L95I and S97R.

Molecular epidemiology and serogroup 6 capsular gene evolution of pneumococcal carriage in a Japanese birth cohort study

Antibiotic resistance in Streptococcus pneumoniae is a major concern worldwide. However, it is unclear whether resistance is associated with only a few highly prevalent clones or numerous and diverse clones. We monitored 349 healthy children and obtained nasopharyngeal cultures at five time points coinciding with health check-ups (4, 7, 10, 18 and 36 months) between 2008 and 2012. A total of 497 S. pneumoniae isolates from 257 healthy children were characterized using capsular serotyping, multilocus sequence typing and antibiotic resistance genotyping (ermB, mefA/E and pbp mutations). Among these isolates, 25 serotypes and 66 sequence types (STs) were found, including 24 new STs with 11 new alleles. Although resistance was present in a variety of ST clones, most of the clones (57/66, 86.4 %) had one specific resistant or susceptible genotype. Of 233 phenotypically penicillin-non-susceptible isolates, 196 (84.1 %) belonged to only six clones, comprising ST906B, ST23619F, ST24223F, ST37876A, ST143723F and ST33823A and their variants. We concluded that drug-resistant S. pneumoniae is associated with a limited number of highly prevalent clones that are capable of adapting to the community setting. Furthermore, we analysed the capsular gene evolution in serogroup 6. The strain ST29246D was probably the result of recombination of a 3563 bp fragment of the capsule locus acquired by an ST29246C strain from an ST906B or ST29246B strain. Compared with previous studies, our results showed a different recombination site (wciN and wzx) and a different cps profile (8-7-11), indicating that serogroup 6 strains have multiple sites for cps recombination as a mechanism of vaccine escape.

Incidence of venous thromboembolism after spine surgery

BACKGROUND

The incidence of venous thromboembolism (VTE) has varied among studies of patients undergoing elective spine surgery. This may be because of differences in prophylaxis for VTE and differences in methods of observation. Furthermore, some studies have reported symptomatic deep vein thrombosis (DVT) or pulmonary thromboembolism (PE), whereas others have included asymptomatic DVT or PE, making comparisons difficult. Therefore, the objective of this study was to determine the incidence of symptomatic and asymptomatic PE in patients undergoing elective spine surgery and to evaluate therapeutic methods for these conditions.

METHODS

The subjects were 1975 patients who underwent spine surgery in our hospital from 1990 to 2011. Patients treated from January 1990 to November 1996 (n = 541, Group A) did not receive prophylaxis whereas those treated from January 2000 to February 2011 (n = 1,434, Group B) used a foot pump during and after surgery and subsequently wore elastic stockings. All subjects in Group A began ambulation ≥2 weeks after surgery whereas those in Group B began to walk earlier-within 3 days for patients who underwent decompression and within 1 week for those treated with fusion. From June 2010 to February 2011, contrast-enhanced computed tomography (CT) was performed 1 week after surgery for 100 patients to evaluate the presence of DVT and PE. Since March 2004, D-dimer was measured 1 week after surgery and patients with a level ≥10 μg/mL were followed up.

RESULTS

The incidence of symptomatic PE was significantly higher in Group A than in Group B (8/541, 1.5% vs. 3/1,434, 0.2%). In 3 patients in Group B, PE developed within 1 week postoperatively and D-dimer values at onset were ≤10 μg/mL. In the 100 cases examined by contrast-enhanced computed tomography (CT), asymptomatic PE and VTE were detected in 18 and 19%, respectively. The D-dimer level 1 week after surgery was ≥10 μg/mL in 105 of 841 patients; however, none of these patients had clinically symptomatic VTE for at least 3 months postoperatively.

CONCLUSIONS

Mechanical prophylaxis and early ambulation may be effective in reducing the incidence of symptomatic PE after spine surgery. Asymptomatic PE developed in 18% of patients who received mechanical prophylaxis, but the incidence of symptomatic PE was only 0.2%. Prompt diagnosis and treatment are required for patients who develop symptomatic PE.

[Streptococcus pneumoniae infection and drug resistance in Japan]

In Japan, 7-valent pneumococcal conjugate vaccine was introduced in 2010. The population-based survey of invasive infection in child revealed that 62.7% of the S. pneumoniae isolates showed equal or more than 0.125 microg/mL of penicillin G MIC. ST320 with serotype 19A S. pneumoniae isolates showed 2-4 microg/mL and 0.25-0.5 microg/mL MICs of penicillin G and meropenem, respectively. The early introduction of PCV13 in Japan is anticipated.

[Peritonitis due to post-myomectomy Mycoplasma hominis infection]

A 36-year-old woman undergoing a myomectomy developed postoperative surgical-saite peritonitis and hematoma. Eight days postoperatively, she developed a 38 degrees C-plus fever and accumulated ascites, with fever unchanged despite antimicrobial beta-lactams therapy. Following transvaginal ascitic drainage, her fever disappeared. Recurrent 38 degrees C fever and inflammation were cured by clindamycin of 1.2 g/day. M. hominis detected from ascites drainage was considered the primary causative organism. Nongenito-urinary M. hominis infection is often difficult to detect, as in our case. Gram staining, for example, is not useful in ascertaining small organisms such as Mycoplasma spp. having no cell walls to stain. M. hominis grows slowly, requiring over three days to form colonies on blood agar plates, requiring time to identify pathogens. We report case showing the importance of suspecting M. hominis of causing gynecological surgical-site infection. When common bacterial pathogen cultures remain negative and when empiric beta-lactam antibiotic treatment is ineffective, M. hominis should be suspected. In conclusion, M. hominis should be considered a causative following myomectomy resection.

[A case of Desulfovibrio desulfuricans cultured from blood in Japan]

We report a case of Desulfovibrio desulfuricans bacteremia in a 60-year-old-man. In our case, anaerobic blood culture bottle turned out positive after five days' incubation. Gram stain showed the presence of slightly-curved Gram negative rod. Suspecting Campylobacter and Helicobacter, we added microaerobic culture while tentatively reporting Campylobacter to the physician. We then added anaerobic culturing with Brucella HK (RS) Agar because microaerobic culture proved the absence of microaerophile. We found small colonies on the third day, then we started anaerobic culture and eventually identified Desulfovibrio desulfuricans. We believe this is the first report of Desulfovibrio desulfuricans cultured from blood in Japan. In case Gram stain shows the presence of spiral bacterium, it is recommended to observe closely considering Desulfovibrio.

Isolated neck extensor myopathy causing a dropped head: a case report

This report is of a 71-year-old woman who presented with a dropped head and difficulty in extending her neck. She was diagnosed with isolated neck extensor myopathy. Conservative treatment (use of a cervical collar and muscular strength training) temporarily improved her symptoms. However, destruction of cervical vertebrae and myelopathy progressed secondary to repeated microfractures from mechanical stress. The patient underwent 2-stage combined anterior and posterior decompression and fusion using autografts. At one-year follow-up, numbness of the bilateral upper limbs had resolved, and bone union was achieved. The patient was able to look straight ahead and was very satisfied with the outcome.

Serotyping and multilocus sequence typing of Streptococcus pneumoniae isolates from the blood and posterior nares of Japanese children prior to the introduction of 7-valent pneumococcal conjugate vaccine

In Japan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2010. To assess the effects of PCV7 on invasive pneumococcal infection in children, a population-based prospective survey has been conducted in 10 prefectures. As a part of the study, blood and nasopharyngeal isolates from children admitted to the Shibata Hospital, Niigata Prefecture, were analyzed for determining the serotypes, their susceptibilities to antimicrobial agents, and multilocus sequence types. Sixteen blood isolates were obtained from October 2007 to December 2009. Sixty-three nasopharyngeal isolates were obtained from the posterior nares of 118 children with pneumonia from April to September 2008. The coverage rates of the blood and nasopharyngeal isolates for PCV7 were 81.3% and 57.1%, respectively. Although none of these children had received PCV7, serotype 19A isolates were recovered from 12.5% (2/16) of the blood samples and 12.7% (8/63) of the nasopharyngeal samples. The sequence type of a nasopharyngeal isolate of serotype 19A was ST320, and the minimum inhibitory concentration of penicillin G was 4 μg/mL. In addition to the continuous prospective survey of pneumococcal infection, early introduction of the 13-valent conjugate vaccine, in which the 19A conjugate is included, will be necessary in Japan.

Effect of cage geometry on sagittal alignment after posterior lumbar interbody fusion for degenerative disc disease

PURPOSE

To compare the sagittal alignment of the lumbar spine after one-segment posterior lumbar interbody fusion (PLIF) using the horizontal cylinder (HC) or open box (OB) type cage.

METHODS

66 patients underwent instrumented one-segment PLIF with bone grafting for lower lumbar degenerative disease. HC-type cages were used in 33 men and 13 women aged 20 to 73 (mean, 47) years between September 2001 and July 2004. OB-type cages with a 3-degree lordotic angle were used in 9 men and 11 women aged 25 to 70 (mean, 53) years between July 2004 and September 2006. Pre- and post-operative lumbar lordosis and intervertebral body angles in the fused and upper adjacent levels in the 2 groups were compared.

RESULTS

There was no significant difference between the 2 groups with regard to changes in the lumbar lordosis and intervertebral body angle in the fused and upper adjacent levels. In both groups, the upper adjacent intervertebral body angle increased significantly by about 2 degrees.

CONCLUSION

Lumbar alignment was similar after the use of the HC- or OB-type cages. This may be due to the surgical procedure and insufficient cage lordotic angle.