Bone Turnover Markers in Patients With Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine

STUDY DESIGN

A prospective, single-center, observational study.

OBJECTIVE

To explore the association between serum levels of bone turnover markers and ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine.

SUMMARY OF BACKGROUND DATA

The relationship between bone turnover markers, such as N-terminal propeptide of type I procollagen (PINP) or tartrate-resistant acid phosphate 5b (TRACP-5b), and OPLL has previously been examined. However, the correlation between these markers and thoracic OPLL, which is more severe than cervical-only OPLL, remains unclear.

METHODS

This prospective study included 212 patients from a single institution with compressive spinal myelopathy and divided them into those without OPLL (Non-OPLL group, 73 patients) and those with OPLL (OPLL group, 139 patients). The OPLL group was further subdivided into cervical OPLL (C-OPLL, 92 patients) and thoracic OPLL (T-OPLL, 47 patients) groups. Patients' characteristics and biomarkers related to bone metabolism, such as calcium, inorganic phosphate (Pi), 25-hydroxyvitamin D, 1α,25 dihydroxyvitamin D, PINP, and TRACP-5b, were compared between the Non-OPLL and OPLL groups, as well as the C-OPLL and T-OPLL groups. Bone metabolism biomarkers were also compared after adjusting for age, sex, body mass index, and the presence of renal impairment using propensity score-matched analysis.

RESULTS

The OPLL group had significantly lower serum levels of Pi and higher levels of PINP versus the Non-OPLL group as determined by propensity score-matched analysis. The comparison results between the C-OPLL and T-OPLL groups using a propensity score-matched analysis showed that T-OPLL patients had significantly higher concentrations of bone turnover markers, such as PINP and TRACP-5b, compared with C-OPLL patients.

CONCLUSIONS

Increased systemic bone turnover may be associated with the presence of OPLL in the thoracic spine, and bone turnover markers such as PINP and TRACP-5b can help screen for thoracic OPLL.

Postoperative Complications of Surgery for Cervical Spondylotic Myelopathy with and Without Athetoid Cerebral Palsy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

With the aging of the Japanese population, patients with athetoid cerebral palsy (ACP) are getting older, and the rate of surgery for CSM is increasing in ACP patients. However, postoperative complications of such surgery among adult patients with ACP have not been reported yet. We investigated postoperative complications of surgery for CSM with ACP and compared them with those of surgery for CSM without ACP using a national inpatient database of Japan.

METHODS

Using the Diagnosis Procedure Combination database, we identified 61382 patients who underwent surgery for CSM from July 2010 to March 2018. We examined patient backgrounds, surgical procedures, and type of hospital, and a 4:1 propensity score matching was performed to compare the outcomes between the non-ACP and ACP groups.

RESULTS

There were 60 847 patients without ACP and 535 patients with ACP. The mean age was 68.5 years in the non-ACP group and 55 years in the ACP group. The percentages of patients who underwent fusion surgery were 21.6% and 68.8% in the non-ACP and ACP groups, respectively. The 4:1 propensity score matching selected 1858 in the non-ACP group and 465 in the ACP group. The ACP group was more likely to have postoperative urinary tract infection (.4% vs 2.8%, P < .001), postoperative pneumonia (.4% vs 2.4%, P < .001), and 90-day readmission for reoperation (1.9% vs 4.3%, P = .003).

CONCLUSIONS

We found that ACP patients were more vulnerable to postoperative complications and reoperation after CSM than non-ACP patients.

Comparative Analysis of Microendoscopic and Open Laminectomy for Single-Level Lumbar Spinal Stenosis at L1-L2 or L2-L3

BACKGROUND

Several reports have highlighted comparable surgical outcomes between microendoscopic laminectomy (MEL) and open laminectomy (open) for lumbar spinal stenosis. However, the unilateral approach in MEL may present challenges for the upper lumbar levels, where facet joints are located deeper inside. Our objective was to compare surgical outcomes and radiographic evaluations for single-level decompression cases at L1-L2 or L2-L3 between MEL and open laminectomy.

METHODS

We analyzed patients who underwent single-level decompression for upper lumbar spinal stenosis at 12 distinguished spine centers from April 2017 to September 2021. Baseline demographics, preoperative, and 1-year postoperative patient-reported outcomes, along with imaging parameters, were compared between the MEL and open groups. To account for potential confounding, patients' backgrounds were adjusted using the inverse probability weighting method based on propensity scores.

RESULTS

Among the 2487 patients undergoing decompression surgery, 118 patients (4.7%) underwent single-level decompression at L1-L2 or L2-L3. Finally, 80 patients (51 in the MEL group, 29 in the open group) with postoperative data were deemed eligible for analysis. The MEL group exhibited significantly improved postoperative EuroQol 5-Dimension values compared to the open group. Additionally, the MEL group showed a lower facet preservation rate according to computed tomography examination, whereas the open group had a higher incidence of retrolisthesis.

CONCLUSIONS

Although overall surgical outcomes were similar, the MEL group demonstrated potential advantages in enhancing EuroQol 5-Dimension scores. The MEL group's lower facet preservation rate did not translate into a higher postoperative instability rate.

Patients with a large ossification of the posterior longitudinal ligament have a higher incidence of arteriosclerosis in the carotid artery

PURPOSE

This study aimed to investigate the impact of the severity of cervical ossification of the posterior longitudinal ligament (OPLL) on the incidence of arteriosclerosis in the carotid artery.

METHODS

Patients with OPLL-induced cervical myelopathy were prospectively enrolled. The study involved analyzing patient characteristics, blood samples, computed tomography scans of the spine, and intima-media thickness (IMT) measurements of the common carotid artery. Patients were divided into two groups based on the size of the cervical OPLL to compare demographic data, comorbidities, and the presence of thickening of the carotid intima-media (max IMT ≥ 1.1 mm).

RESULTS

The study included 96 patients (mean age: 63.5 years; mean body mass index: 26.9 kg/m2; 71.8% male; 35.4% with diabetes mellitus). The mean maximum anteroposterior (AP) diameter of the OPLL was 4.9 mm, with a mean occupancy ratio of 43%. The mean maximum IMT was 1.23 mm. Arteriosclerosis of the carotid artery was diagnosed in 62.5% of the patients. On comparing the two groups based on OPLL size, the group with larger OPLL (≥ 5 mm) had a higher BMI and a greater prevalence of carotid intima-media thickening. This significant difference in the prevalence of carotid intima-media thickening persisted even after adjusting for patient backgrounds using propensity score matching.

CONCLUSIONS

Patients with a larger cervical OPLL showed a higher frequency of intima-media thickening in the carotid artery.

Impact of the COVID-19 pandemic on surgical volume and outcomes in spine surgery: a multicentre retrospective study in Tokyo

OBJECTIVES

To investigate the effect of the COVID-19 pandemic on surgical volume and outcomes in spine surgery.

DESIGN

A retrospective cohort study using prospectively collected data.

SETTING AND PARTICIPANTS

A total of 9935 patients who underwent spine surgery between January 2019 and December 2021 at eight high-volume spine centres in the Greater Tokyo metropolitan area were included.

OUTCOME MEASURES

The primary outcome measures were the number of surgical cases, perioperative complications and patient-reported outcomes, including numerical rating scales for each body part, Euro quality of life 5-dimension (EQ5D), Neck Disability Index and Oswestry Disability Index (ODI).

RESULTS

The total number of surgeries in 2020 and 2021 remained lower than that of 2019, with respective percentages of 93.1% and 95.7% compared with the prepandemic period, with a marked reduction observed in May 2020 compared with the same period in 2019 (56.1% decrease). There were no significant differences between the prepandemic and postpandemic groups in the incidence of perioperative complications, although the frequency of reoperation tended to be higher in the postpandemic group (3.04% vs 3.76%, p=0.05). Subgroup analysis focusing on cervical spine surgery revealed significantly worse preoperative EQ5D scores in the postpandemic group (0.57 vs 0.54, p=0.004). Similarly, in lumbar spine surgery, the postpandemic group showed higher levels of leg pain (5.7 vs 6.1 to 0.002) and worse ODI scores (46.2 vs 47.7 to 0.02). However, postoperative outcomes were not different between pre and post-pandemic groups.

CONCLUSIONS

The COVID-19 pandemic has significantly impacted spinal surgeries in Japan, leading to a decrease in surgical volumes and changes in patient characteristics and surgical procedures. However, surgical outcomes remained comparable between the pre and postpandemic periods, indicating the resilience and adaptability of healthcare systems.

Does Surgical Treatment Affect the Degree of Anxiety or Depression in Patients With Degenerative Cervical Myelopathy?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Preoperative mental state has been reported as one of the factors affecting the surgical outcomes of spine surgery, but few studies have examined in detail how patients' mental state is affected by spine surgery. The purpose of this study was to investigate using the Hospital Anxiety and Depression Scale (HADS) whether surgery improves preoperative depression and anxiety in patients with degenerative cervical myelopathy.

METHODS

We investigated patient-reported outcomes (Mental Component Summary, Physical Component Summary of SF-12 Health Survey, and EQ-5D, Neck Disability Index, JOACMEQ, satisfaction with treatment) and HADS one year after surgery, comparing them before and after surgery between April 2017 and February 2020. Among the cases diagnosed as preoperative anxiety and depression, we additionally compared the patient-reported outcomes based on the presence or absence of postoperative improvement in mental state, having also investigated the correlation between patient-reported outcomes and HADS for sub-analysis.

RESULTS

Among the 99 patients eligible for inclusion in the present study, we found that patient-reported outcomes and the HADS scores improved significantly after surgery. There was a moderate correlation between the amount of change in HADS-D score before and after surgery and the amount of change in NDI (moderate, r = .41), NRS of neck (moderate, r = .46), and JOACMEQ (cervical spine function; moderate, r = .43, upper extremity function; moderate, r = .41, QOL; moderate, r = .41).

CONCLUSIONS

We found that surgical treatment for patients with degenerative cervical myelopathy may improve postoperative anxiety and depression as well as other patient-reported outcomes.

Reduced volume and altered composition of paraspinal muscles in Marfan syndrome: A retrospective cohort study

Retrospective cohort study. Spinal deformities in patients with Marfan syndrome (MFS) are distinct from those in patients with idiopathic scoliosis (IS). It is more prone to progression and more likely to present with sagittal malalignment than IS. However, the etiology of this characteristic spinal deformity in MFS remains unclear. This study aimed to determine the spinal musculature characteristics in patients with MFS on the hypothesis that the paraspinal muscles of patients with MFS would be qualitatively or quantitatively different from those of patients with IS. Seventeen consecutive patients with MFS aged 25 years or younger undergoing surgery for scoliosis in our hospital were compared with age- and sex-matched patients with IS undergoing surgery for scoliosis. The body size-adjusted relative cross-sectional area (rCSA), fatty infiltration ratio (FI%), and relative functional cross-sectional area (rFCSA) of the psoas muscles (PM) and paravertebral muscles (PVM) at L3/4 and L4/5 were measured using preoperative T2-weighted magnetic resonance imaging. Functional CSA was defined as total CSA minus the fatty infiltration area of each muscle and rFCSA was calculated as the body size-adjusted functional CSA. The rCSA of the PM at L3/4 and L4/5 was significantly smaller in the MFS group than in the IS group (L3/4, P = .021; L4/5, P = .002). The FI% of the PM at L4/5 was significantly higher in the MFS group (P = .044). Consequently, the rFCSA of the PM at L3/4 and L4/5 and the rFCSA of the PVM at L3/4 in the MFS group were significantly smaller than those in the IS group (PM at L3/4, P = .021; PM at L4/5, P = .001; PVM at L3/4, P = .025). Compared with patients with IS, patients with MFS exhibited significantly decreased body-size-adjusted CSA of the PM and reduced body-size-adjusted functional CSA of the PVM and PM. These findings may partially explain the characteristics of distinctive spinal deformities in patients with MFS.

A Novel Screening Method for Scoliosis Using a Bodysuit and 3-Dimensional Imaging

STUDY DESIGN

A single-center prospective observational study.

OBJECTIVE

To clarify the usefulness of a novel scoliosis screening method using a 3-dimensional (3D) human fitting application and a specific bodysuit.

SUMMARY OF BACKGROUND DATA

Several scoliosis screening methods, such as scoliometer and Moiré topography, are available for detecting scoliosis. In the present study, a novel screening method for scoliosis using a 3D human fitting application and a specific bodysuit was developed.

PATIENTS AND METHODS

Patients with scoliosis or suspected scoliosis, patients with non-scoliosis, and healthy volunteers were enrolled. They were divided into "non-scoliosis" and "scoliosis" groups. The scoliosis group was further subdivided into "mild," "moderate," and "severe-scoliosis" groups. Patients' characteristics and Z values, which were calculated by a 3D virtual human body model created by a 3D human fitting application and a specific bodysuit to evaluate trunk asymmetry caused by scoliosis, were compared between the non-scoliosis and scoliosis groups or among the non, mild, moderate and severe-scoliosis groups. Finally, the optimal cutoff of the Z value was determined to detect moderate to severe scoliosis using receiver operating characteristic curve analysis.

RESULTS

A total of 101 patients were included. The non-scoliosis group consisted of 47 patients, and the scoliosis group included 54 patients, with 11, 31, and 12 patients in the mild, moderate, and severe-scoliosis groups, respectively. The scoliosis group showed a significantly higher Z value than the non-scoliosis group. The moderate or severe-scoliosis group had a significantly higher Z value than the non or mild-scoliosis group. The receiver operating characteristic curve analysis revealed that the optimal cutoff of the Z value was 19.9 mm (sensitivity, 95.3% and specificity, 58.6%).

CONCLUSION

A novel scoliosis screening method consisting of a 3D human fitting application and a specific bodysuit may be useful for detecting moderate to severe scoliosis.

Adaptation and Limitations of painDETECT Questionnaire Score Approach Before and After Posterior Cervical Decompression Surgery

BACKGROUND

The painDETECT questionnaire (PDQ) is one of the available screening tools for neuropathic pain (NeP), with a cut-off score of 13. This study aimed to investigate changes in PDQ scores in patients undergoing posterior cervical decompression surgery for degenerative cervical myelopathy (DCM).

METHODS

Patients with DCM undergoing cervical laminoplasty or laminectomy with posterior fusion were recruited. They were asked to complete a booklet questionnaire including PDQ and Numerical Rating Scales (NRS) for pain at baseline and one year after surgery. Patients with a preoperative PDQ score ≥13 were further investigated.

RESULTS

A total of 131 patients (mean age = 70.1 years; 77 male and 54 female) were analyzed. After posterior cervical decompression surgery for DCM, mean PDQ scores decreased from 8.93 to 7.28 (P = 0.008) in all patients. Of the 35 patients (27%) with preoperative PDQ scores ≥13, mean PDQ changed from 18.83 to 12.09 (P < 0.001). Comparing the NeP improved group (17 patients with postoperative PDQ scores ≤12) with the NeP residual group (18 patients with postoperative PDQ scores ≥13), the NeP improved group showed less preoperative neck pain (2.8 vs. 4.4, P = 0.043) compared to the NeP residual group. There was no difference in the postoperative satisfaction rate between the two groups.

CONCLUSIONS

Approximately 30% of patients exhibited preoperative PDQ scores ≥13, and about half of these patients demonstrated improvements to below to the cut-off value for NeP after posterior cervical decompression surgery. The PDQ score change was relatively associated with preoperative neck pain.

Impact of body mass index on outcomes after lumbar spine surgery

The impact of body mass index (BMI) on outcomes after lumbar spine surgery is currently unknown. Previous studies have reported conflicting evidence for patients with high BMI, while little research has been conducted on outcomes for underweight patients. This study aims to examine the impact of BMI on outcomes after lumbar spine surgery. This prospective cohort study enrolled 5622 patients; of which, 194, 5027, and 401 were in the low (< 18.5 kg/m²), normal (18.5-30), and high (≥ 30) BMI groups, respectively. Pain was assessed via the numerical pain rating scale (NPRS) for the lower back, buttock, leg, and plantar area. Quality of life was assessed via the EuroQol 5 Dimension (EQ-5D) and Oswestry Disability Index (ODI). Inverse probability weighting with propensity scores was used to adjust patient demographics and clinical characteristics between the groups. After adjustment, the 1-year postoperative scores differed significantly between groups in terms of leg pain. The proportion of patients who achieved a 50% decrease in postoperative NPRS score for leg pain was also significantly different. Obese patients reported less improvement in leg pain after lumbar spine surgery. The outcomes of patients with low BMI were not inferior to those of patients with normal BMI.

A dynamic pedicle screw system using polyethylene insert for the lumbar spine

Rigid spinal fusion with instrumentation has been widely applied in treating degenerative spinal disorders and has shown excellent and stable surgical results. However, adjacent segment pathology or implants' loosening could be problematic due to the spine's segmental fusion. Therefore, this study verified a novel concept for posterior stabilization with polyethylene inserts inside a pedicle screw assembly using bone models. We observed that although the gripping capacity of the dynamic pedicle screw system using a tensile and compression tester was less than half that of the rigid pedicle screw system, the flexion-extension moment of the dynamic pedicle screws was significantly lower than that of the rigid pedicle screws. Furthermore, while the bending force of the rigid pedicle screw assembly increased linearly with an increase in the bending angle throughout the test, that of the dynamic pedicle screw assembly also increased linearly until a bending angle of 2.5° was reached. However, this angle decreased at a bending angle of more than 2.5°. Additionally, the fatigue test of 1.0 × 10⁶ cycles showed that the pull-out force of the dynamic pedicle screws from two different polyurethane foam blocks was significantly higher than that of the rigid pedicle screws. Therefore, based on our results, we propose that the device can be applied in clinical cases to reduce screw loosening and adjacent segment pathology.

Association Between Deep Posterior Cervical Paraspinal Muscle Morphology and Clinical Features in Patients With Cervical Ossification of the Posterior Longitudinal Ligament

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

To clarify the association of the paraspinal muscle area and composition with clinical features in patients with cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

Consecutive patients with cervical OPLL who underwent cervical magnetic resonance imaging (MRI) before surgery were reviewed. The cross-sectional area (CSA) and fatty infiltration ratio (FI%) of deep posterior cervical paraspinal muscles (multifidus [MF] and semispinalis cervicis [SCer]) were examined. We assessed the association of paraspinal muscle measurements with the clinical characteristics and clinical outcomes, such as Neck Disability Index (NDI) score. Moreover, we divided the patients into 2 groups according to the extent of the ossified lesion (segmental and localized [OPLL-SL] and continuous and mixed [OPLL-CM] groups) and compared these variables between the 2 groups.

RESULTS

49 patients with cervical OPLL were enrolled in this study. The FI% of the paraspinal muscles was significantly associated with the number of vertebrae (ρ = 0.283, p = 0.049) or maximum occupancy ratio of OPLL (ρ = 0.397, p = 0.005). The comparative study results indicated that the NDI score was significantly worse (OPLL-SL, 22.9 ± 13.7 vs. OPLL-CM, 34.4 ± 13.7) and FI% of SCer higher (OPLL-SL, 9.1 ± 1.7% vs. OPLL-CM, 11.1 ± 3.7%) in the OPLL-CM group than those in the OPLL-SL group.

CONCLUSIONS

Our results suggest that OPLL severity may be associated with fatty infiltration of deep posterior cervical paraspinal muscles, which could affect neck disability in patients with cervical OPLL.

Does T1 slope minus cervical lordosis mismatch affect surgical outcomes of cervical laminoplasty in the absence of preoperative severe kyphosis?

Background

The impact of the T1 slope minus cervical lordosis (T1S-CL) on surgical outcomes in patients with degenerative cervical myelopathy undergoing laminoplasty (LP) remain uncertain.

Methods

One hundred patients who underwent cervical LP were retrospectively reviewed. Radiographic measurements included C2–C7 lordosis (CL), T1 slope (T1S), and C2–C7 sagittal vertical axis (SVA). Additionally, pain numeric rating scale, neck disability index (NDI), 12-Item Short-Form Health Survey, Euro QOL 5 dimensions (EQ5D), and Japanese Orthopedic Association score were investigated. According to past reports, T1S–CL > 20° was defined as mismatched. Then, based on T1S-CL mismatching, patients were divided into 2 groups.

Results

This research understudied 67 males and 33 females with a mean age of 67 y. Preoperatively, only eight patients showed a T1S-CL mismatch. While the C2–7 Cobb angles did not change significantly after surgery, the T1 slope (T1S) angle increased, increasing the T1S-CL as a result. As we compared the clinical outcomes based on the preoperative T1S-CL mismatching, there were no significant differences between the two groups. On the other hand, the number of patients in the mismatched group increased to 21 patients postoperatively. As we compared clinical outcomes based on the postoperative T1S-CL mismatching, the postoperative NDI score and preop/postop EQ5D score were significantly worse in the mismatch group.

Conclusions

Although cervical LP showed inferior outcomes in patients with postoperative T1S-CL mismatch even in the absence of severe preoperative kyphosis (> 10°), preoperative T1S-CL mismatch was not adversely prognostic.

Evaluation of bone strength using finite-element analysis in patients with ossification of the posterior longitudinal ligament

BACKGROUND CONTEXT

Patients with ossification of the posterior longitudinal ligament (OPLL) are often reported to have increased bone mineral density (BMD). The bone strength of the proximal femur measured by quantitative computed tomography-based finite element analysis (QCT/FEA) is reportedly comparable between healthy subjects with and without OPLL. However, the bone strength in symptomatic OPLL patients remains unknown.

PURPOSE

To investigate bone strength measured by QCT/FEA in symptomatic patients with OPLL.

STUDY DESIGN/SETTING

A single-center prospective observational study.

PATIENT SAMPLE

A total of 157 patients with cervical or thoracic compressive myelopathy were included in the study.

OUTCOME MEASURES

We analyzed patients' characteristics, Japanese Orthopedic Association (JOA) score, serum laboratory tests including calcium (Ca), inorganic phosphate (Pi), and bone turnover markers, BMD of the proximal femur and lumbar spine measured using dual-energy X-ray absorptiometry, and predicted bone strength (PBS) of the proximal femur and lumbar spine measured using QCT/FEA.

METHODS

Eligible patients were divided into the non-OPLL and OPLL groups. We compared the patients' characteristics, JOA scores, laboratory data, BMD, and PBS of the proximal femur and lumbar spine between the non-OPLL and OPLL groups among total, male, and female patients by performing Fisher's exact test for categorical variables and the unpaired t test for continuous variables. Then, we used the inverse probability weighted logistic regression model after calculating propensity scores to compare the bone metabolism-associated markers, BMD, and PBS measurements between the groups.

RESULTS

Among the eligible 157 patients, 68 were in the non-OPLL group and 89 were in the OPLL group. Compared with the non-OPLL group, the OPLL group had a significantly younger age and higher BMI in the total, male, and female patients. The JOA scores in the total and female patients were significantly higher in the OPLL group than in the non-OPLL group. The OPLL group showed significantly lower Ca levels in the female patients and significantly lower Pi levels in the total or male patients compared with the non-OPLL group in the inverse probability weighting method. The BMD of the proximal femur and lumbar spine and the PBS of the proximal femur were significantly higher in the OPLL group than in the non-OPLL group. There were no significant differences in the PBS and BMD between the male subgroups. However, the BMD and PBS of the proximal femur and lumbar spine were significantly higher in the OPLL females than in the non-OPLL females.

CONCLUSIONS

Hyperostosis of the posterior longitudinal ligament in OPLL was associated with higher bone strength by QCT/FEA, especially in female OPLL patients.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for single-level lumbar spinal stenosis: a multicenter retrospective cohort study

Background

Microendoscopic laminectomy (MEL), in which a 16-mm tubular retractor with an internal scope is used, has shown excellent surgical results for patients with lumbar spinal canal stenosis. However, no reports have directly compared MEL with open laminectomy. This study aimed to elucidate patient-reported outcomes (PROs) and perioperative complications in patients undergoing MEL versus open laminectomy.

Methods

This is a multicenter retrospective cohort study of prospectively registered patients who underwent lumbar spinal surgery at one of the six high-volume spine centers between April 2017 and September 2018. A total of 258 patients who underwent single posterior lumbar decompression at L4/L5 were enrolled in the study. With regard to demographic data, we prospectively used chart sheets to evaluate the diagnosis, operative procedure, operation time, estimated blood loss, and complications. The follow-up period was 1-year. PROs included a numerical rating scale (NRS) for lower back pain and leg pain, the Oswestry Disability Index (ODI), EuroQol 5 Dimension (EQ-5D), and patient satisfaction with the treatment.

Results

Of the 258 patients enrolled, 252 (97%) completed the 1-year follow-up. Of the 252, 130 underwent MEL (MEL group) and 122 underwent open decompression (open group). The MEL group required a significantly shorter operating time and sustained lesser intraoperative blood loss compared with the open group. The MEL group showed shorter length of postoperative hospitalization than the open group. The overall complication rate was similar (8.2% in the MEL group versus 7.7% in the open group), and the revision rate did not significantly differ. As for PROs, both preoperative and postoperative values did not significantly differ between the two groups. However, the satisfaction rate was higher in the MEL group (74%) than in the open group (53%) (p = 0.02).

Conclusions

MEL required a significantly shorter operating time and resulted in lesser intraoperative blood loss compared with laminectomy. Postoperative PROs and complication rates were not significantly different between the procedures, although MEL demonstrated a better satisfaction rate.

Adverse effects of surgeon performance after a night shift on the incidence of perioperative complications in elective thoracolumbar spine surgery

BACKGROUND

Decline in cognitive function after night shift has been well described. However, in the field of spine surgery, the effect of surgeons' sleeplessness on patient outcome is unclear. The purpose of this study was to investigate whether the risk of perioperative complications in elective thoracolumbar spine surgery could be higher if the surgeon had been on a night shift prior to the day of surgery.

METHODS

We performed a retrospective review of patients who underwent elective posterior thoracolumbar spine surgery, as indicated in medical records, between March 2015 and September 2018. In total, 1189 patients were included and divided into two groups: the post-nighttime (n = 110) and control groups (n = 1079). A post-nighttime case was defined when the operating surgeon was on nighttime duty on the previous night, and other cases were defined as controls. We evaluated the incidence of perioperative complications (surgical site infection, postoperative hematoma, postoperative paralysis, nerve root injury, and dural tear) in both groups.

RESULTS

Overall, we found no significant difference in the major or minor perioperative complication rates between the two groups, but according to the type of complication, the incidence rate of dural tear tended to be higher in the post-nighttime group (13.6% vs 8.2%, P = 0.074). Multivariate analysis showed that post-nighttime status was an independent risk factor of dural tear (adjusted odds ratio, 2.02; 95% confidence interval [CI], 1.10-3.70; P = 0.023). After stratification by surgical complexity, post-nighttime status was an independent risk factor of dural tear only in the surgeries of 3 levels or more (adjusted odds ratio, 2.81; 95% CI, 1.18-6.67; P = 0.019).

CONCLUSIONS

Post-nighttime status was generally not a risk factor of perioperative complications in elective posterior thoracolumbar spine surgeries, but was an independent risk factor of dural tear, especially in complex cases.

Pelvic incidence change on the operating table

PURPOSE

While a change in the pelvic incidence (PI) after long spine fusion surgery has been reported, no studies have examined the change in the PI on the operating table. The present study examined the PI-change on the operating table and elucidated the patients' background characteristics associated with this phenomenon.

METHODS

This study included patients who underwent lumbar posterior spine surgery and had radiographs taken in a full-standing position preoperatively and a pelvic lateral radiograph in the prone position in the operative room. The patients with PI-change on the operating table (PICOT; PICOT group) and without PICOT (control group) were compared for their background characteristics and preoperative radiographic parameters.

RESULTS

There were 128 eligible patients (62 males, 66 females) with a mean age (± standard deviation) of 69.9 ± 11.7 (range: 25-93) years old. Sixteen patients (12.5%) showed a decrease in the PI > 10°, which indicated placement in the PICOT group. The preoperative lumbar lordosis (LL) and PI-LL in the PICOT group were significantly worse than those in the control group (LL: 20.8 ± 16.6 vs. 30.6 ± 16.2, p = 0.0251, PI-LL: 33.9 ± 19.0 vs. 17.3 ± 14.8, p < 0.0001). The PICOT group had a higher proportion of patients who underwent fusion surgery than the control group, but the difference was not significant (62.5% vs. 44.6%, p = 0.1799).

CONCLUSION

A decreased PI was observed in some patients who underwent lumbar posterior surgery on the operating table before surgery. Patients with a PI decrease on the operating table had a significantly worse preoperative global alignment than those without such a decrease.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Validity of the Japanese core outcome measures index (COMI)-neck for cervical spine surgery: a prospective cohort study

PURPOSE

To investigate the psychometric properties of the Japanese version of the Core Outcome Measures Index-Neck (COMI-Neck) in patients undergoing cervical spine surgery.

METHODS

A total of 177 patients undergoing cervical spine surgery for spinal disorders from April to December 2017 were enrolled. Patient-reported outcomes (PROs) included EuroQOL, Neck Disability Index, and treatment satisfaction. To address whether the questionnaire's scores relate to other outcomes based on a predefined hypothesis, the correlations between the COMI-Neck and the other PROs were measured (Spearman's rank correlation coefficients). The minimum clinically important difference (MCID) of the COMI summary score was calculated using the receiver operating characteristic (ROC) curve with a 7-point Likert scale of satisfaction with the treatment results. To assess reproducibility, another group of 59 volunteers with chronic neck pain were asked to reply to the COMI-Neck twice with an interval of 7-14 days.

RESULTS

The COMI summary score showed no floor or ceiling effects preoperatively or postoperatively. Each of the COMI domains and the COMI summary score correlated to the hypothesized extent with the scores of the reference questionnaires (ρ = 0.40-0.79). According to the ROC curve with satisfaction (including "very satisfied" and "satisfied"), the area under the curve and MCID of the COMI summary score were 0.78 and 2.1. The intraclass correlation coefficient and the minimum detectable change (MDC 95%) of the COMI summary score were 0.97 and 0.77.

CONCLUSION

The Japanese version of the COMI-Neck is valid and reliable for Japanese-speaking patients with cervical spinal disorders.

Validity of the Japanese Core Outcome Measures Index (COMI)-Back for thoracic and lumbar spine surgery: a prospective cohort study

PURPOSE

To investigate the psychometric properties of the Japanese version of the Core Outcome Measures Index-Back (COMI-Back), only recently published according to the established linguistic and cultural conversion guidelines, in patients undergoing spine surgery.

METHODS

We recruited 145 patients who underwent thoracic or lumbar spine surgery in one of the five specific tertiary care institutions. They were asked to complete a booklet questionnaire (the COMI-Back, the Numerical Rating Scale for pain, the Short Form-12, Euro-QOL-5 dimensions, and Oswestry Disability Index) at baseline and 12 months postoperatively to investigate floor/ceiling effect, construct validity, and postoperative responsiveness. The patients were also asked to answer an anchor question (Global Treatment Outcome) to analyze the minimum clinically important difference (MCID) by receiver operating characteristics curves. Of the 145 patients, 112 completed the study. Another group of 59 volunteers with chronic symptoms completed the questionnaire twice within a 7-14-day interval for the test-retest reproducibility.

RESULTS

The COMI summary score displayed no notable floor or ceiling effects. Except for symptom-specific well-being, the individual COMI domains and the COMI summary score correlated as expected with the scores of the chosen reference measures (ρ = 0.4-0.8). A similar trend was observed between the pre-/postoperative changes in the COMI score and those in the reference measures. The MCID for the COMI summary score was 2.5. The intraclass correlation coefficient and minimum detectable change (MDC95%) were 0.93 and 1.26, respectively.

CONCLUSION

The Japanese COMI-Back was a reliable and responsive questionnaire in our Japanese patients undergoing thoracic/lumbar spine surgery. These slides can be retrieved under Electronic Supplementary Material.

Prostaglandin E1 produces spasmolytic effects on histamine-induced bronchoconstriction in dogs

OBJECTIVE

In this study, we evaluated the spasmolytic effect of intravenous prostaglandin (PG) E1 on histamine-induced bronchoconstriction with a direct visualization method using a superfine fiberoptic bronchoscope.

SETTING

A university research laboratory.

SUBJECTS

Mongrel dogs.

INTERVENTIONS

The bronchial cross-sectional area (BCA) of mongrel dogs was measured by a direct visualization method using a superfine fiberoptic bronchoscope. Bronchoconstriction was elicited with histamine (H) infusion: 10 microg/kg iv bolus + 500 microg/kg/h continuous iv. The first protocol (n = 7) was designed to determine the effects of intravenous bolus of PGE1: 0 (saline), 0.01, 0.1, 1.0 and 10 microg/kg on H-induced bronchoconstriction. BCA was assessed before and 30 min after starting the H infusion and 5 min after each dose of intravenous PGE1. The second protocol was designed to determine whether continuous intravenous infusion of PGE1 reverses H-induced bronchoconstriction. In the PG group (n = 6), PGE1 was continuously infused at 0.1 microg/kg/min (20 mL/hr). In the control group (n = 6), saline was administered at a rate of 20 mL/hr iv. BCA was assessed before and 30 min after starting the H-infusion and at 5, 10, 30 and 60 min after commencing the PGE1 or saline infusion. Arterial blood was obtained simultaneously for measurement of plasma concentrations of epinephrine and norepinephrine by gas chromatography mass spectrometry.

MEASUREMENTS AND MAIN RESULTS

In the first protocol, PGE1 produced a dose-dependent increase in the percentage of BCA and 10 microg/kg of PGE1 almost fully reversed the H-induced bronchoconstriction. Plasma catecholamines did not change significantly. In the second protocol, continuous infusion of PGE1 produced a time-dependent reversal of H-induced bronchoconstriction (percentage of BCA increased to 80.0+/-9.0% 60 min after the start of PGE1 infusion), whereas saline infusion did not reverse the bronchoconstriction. Plasma catecholamines did not change significantly in either group.

CONCLUSIONS

Both intravenous bolus and continuous intravenous infusion of PGE1 reversed the H-induced bronchoconstriction. PGE1 may be used safely for patients with the hyperreactive airway and might be useful as a therapeutic agent for these patients.

Gastric carcinoma confined to the muscularis propria: how can we detect, evaluate, and cure intermediate-stage carcinoma of the stomach?

OBJECTIVE

The most important surgical strategy for advanced gastric cancer is its detection at the curative stage. The aim of this study was to characterize the curable intermediate-stage gastric carcinomas.

METHODS

Of 1120 consecutive patients who underwent gastric resection for primary gastric cancer from 1979 through 1996, 94 patients were histologically diagnosed as having cancer confined to the muscularis propria (mp cancer), analyzed clinicopathologically, and compared with patients with early and serosal cancers.

RESULTS

The operative incidence of mp cancer was around 8% among cases of gastrectomy, and the ratio of mp cancer to advanced cancer began to increase in 1991. Mp cancer was at a statistically intermediate stage, between early and serosal cancers in terms of symptoms, surgical curability (96%), size and histology of the tumor, and the rate of lymph node metastasis (46%). Preoperative assessments of tumor depth were unclear using radiology and endoscopy; however, 35% of 31 cases studied were diagnosed precisely by endoscopic ultrasonography (EUS). Accuracy of lymph node metastasis diagnosis was the same (65%) by preoperative EUS and by surgeon; however, sensitivity of the surgeon's assessment was higher (69% vs 38%) and specificity of EUS was higher (83% vs 39%). The 5-yr survival rate was 85%, which was significantly better than that of serosal cancer and similar to that of early cancer. Patient outcome was not affected by lymph node metastasis or macroscopic type of tumor.

CONCLUSIONS

Mp cancer should be considered an intermediate-stage cancer. Surgery with level 2 lymph node dissection should provide a cure rate similar to that for early cancer.

Relaxant effect of magnesium and zinc on histamine-induced bronchoconstriction in dogs

OBJECTIVE

Magnesium sulfate (MgSO4) has been reported to produce bronchodilation in asthmatic patients. In vitro studies have suggested that divalent cations inhibit L-type voltage-sensitive calcium ion (Ca2+) channels in cardiac and smooth muscles. In this study, we evaluated the in vitro and in vivo effects of magnesium ion (Mg2+) and zinc ion (Zn2+) on the airway contracted by histamine.

SETTING

A university research laboratory.

SUBJECTS

IN VITRO

Tracheal smooth muscle from guinea pigs.

IN VIVO

Mongrel dogs.

MEASUREMENTS AND MAIN RESULTS

IN VITRO STUDY

The tension of isolated guinea pig tracheal strips was measured isometrically with a force displacement transducer. The specimen was contracted with histamine (10 microM). Then, MgSO4 (n = 6), zinc sulfate (ZnSO4, n = 6), or sodium sulfate (Na2SO4, n = 6) was cumulatively added to the organ bath.

IN VIVO STUDY

The bronchial cross-sectional area of mongrel dogs was measured by a direct visualization method demonstrated previously. The dogs were randomly assigned to three groups: group Mg (n = 7), group Zn (n = 7), and group Na (n = 7). Bronchoconstriction was elicited with histamine (10 microg/kg plus 500 microg/kg/hr iv). Thirty minutes after the start of histamine infusion, 0 (saline), 1, 10, and 100 micromol/kg ZnSO4 or 1, 10, 100, and 1000 micromol/kg MgSO4 or Na2SO4 were administered intravenously in group Zn, Mg, or Na, respectively. The bronchial cross-sectional area was assessed before (basal) and 30 mins after the start of histamine infusion and 5 mins after each dose of ZnSO4, MgSO4, or Na2SO4. Arterial blood was also obtained to measure plasma levels of epinephrine and norepinephrine by gas chromatography-mass spectrometry. All data are expressed as mean +/- SEM. The doses of the divalent cations that reversed histamine-induced contraction by 50% were calculated by GraphPad Prism. MgSO4 and ZnSO4 (9.38+/-0.28 and 1.84+/-0.30 mM, respectively) relaxed histamine-contracted tracheal strip in a concentration-dependent manner, whereas Na2SO4 did not. Similarly, the in vivo study showed that MgSO4 and ZnSO4 dose-dependently reversed histamine-induced bronchoconstriction (potency, ZnSO4 > MgSO4), whereas Na2SO4 did not. In groups Mg and Zn, the plasma catecholamine levels also dose-dependently increased except when 1000 micromol/kg MgSO4 was administered.

CONCLUSION

Because the divalent cations tested produced a spasmolytic effect on the contracted airway, infusion of divalent cations might be effective against asthmatic attack. However, high concentrations of these cations produce significant toxicity, so dosage will be an important concern in development of these agents.

Analysis of rapid eye movement periodicity in narcoleptics based on maximum entropy method

We examined REM sleep periodicity in typical narcoleptics and patients who had shown signs of a narcoleptic tetrad without HLA-DRB1*1501/DQB1*0602 or DR2 antigens, using spectral analysis based on the maximum entropy method. The REM sleep period of typical narcoleptics showed two peaks, one at 70-90 min and one at 110-130 min at night, and a single peak at around 70-90 min during the daytime. The nocturnal REM sleep period of typical narcoleptics may be composed of several different periods, one of which corresponds to that of their daytime REM sleep.

Effects of thiopental on airway calibre in dogs: direct visualization method using a superfine fibreoptic bronchoscope

Induction of anaesthesia with thiopental sometimes causes bronchospasm. Although the mechanism by which thiopental induces bronchospasm may involve cholinergic stimulation, direct spastic effect and histamine release, the spastic effects of thiopental have not been comprehensively defined. In this study, we have assessed the effect of thiopental on in vivo airway smooth muscle tone using direct visualization method with a superfine fibreoptic bronchoscope as previously reported. Twenty-one mongrel dogs were anaesthetized with pentobarbital (30 mg kg-1) and paralysed with pancuronium (200 micrograms kg-1 h-1). The trachea was intubated with a tube that had a second lumen for insertion of the bronchoscope (od: 2.2 mm) to continuously measure bronchial cross-sectional area. The tip of the bronchoscope was placed between the second and third bronchial bifurcation of the right lung. The dogs were allocated to three groups of seven: group T, A+T, H+T. In group T, thiopental 0 (saline), 0.1, 1.0 and 10 mg kg-1 was given i.v. In group A+T, saline i.v., 5 min later atropine 0.1 mg kg-1 i.v., and 5 min later thiopental 10 mg kg-1 was administered. In group H+T, bronchoconstriction was produced with histamine 10 micrograms kg-1 i.v. followed by infusion at 500 micrograms kg-1 h-1. Thirty minutes later, thiopental 0, 1.0 and 10 mg kg-1 were given. Arterial blood sampling was performed for measurement of plasma catecholamines and histamine. In group T, thiopental significantly reduced bronchial cross-sectional area (maximally by 28.7 (5.6% at 0.5 min after thiopental 10 mg kg-1), which returned to the baseline in 3 min, while any changes in plasma concentrations of catecholamines and histamine were not observed except norepinephrine level at 1 min following thiopental 10 mg kg-1 i.v. Atropine pretreatment completely prevented thiopental-induced bronchospasm in group A+T. In group H+T, thiopental 10 mg kg-1 transiently but significantly decreases bronchial cross-sectional area. Therefore, the present study indicates that the mechanism of thiopental bronchospasm may result from cholinergic nerve stimulation.

Midazolam reverses histamine-induced bronchoconstriction in dogs

PURPOSE

Midazolam has been used clinically as a sedative and as an anaesthetic induction agent. However, the bronchodilating effects of midazolam have not been comprehensively evaluated. We sought to determine relaxant effects of midazolam on the airway.

METHODS

After our Animal Care Committee approved the study, eight mongrel dogs were anaesthetized with 30 mg.kg-1 pentobarbitone iv, and were paralysed with 200 micrograms.kg-1.hr-1 pancuronium. The trachea was intubated with an endotracheal tube (ID 7 mm) that had a second lumen for insertion of a superfine fibreoptic bronchoscope (OD 2.2 mm) to measure the bronchial cross-sectional area (BCA) continuously. The tip of the bronchoscope was placed at the level of the second or third bronchial bifurcation of the right bronchus. A videoprinter printed the BCA which was then measured with a NIH image program. Bronchoconstriction was produced with histamine (H) 10 micrograms.kg-1 followed by 500 micrograms.kg-1.hr-1. Thirty minutes later, 0 [saline], 0.01, 0.1 and 1.0 mg.kg-1 midazolam and 25 micrograms.kg-1 flumazenil were given. The BCA was assessed before (basal area) and 30 min after the start of H infusion, and was also measured five minutes after each midazolam and flumazenil iv. At the same time, arterial blood was sampled for plasma catecholamine measurement.

RESULTS

Histamine infusion decreased BCA to 49.7 +/- 17.3% of basal BCA. More than 0.1 mg.kg-1 midazolam increased BCA up to 71.7 +/- 15.3% of the basal (1.0 mg.kg-1) (P < 0.01). Plasma adrenaline concentration was decreased from 6.9 +/- 3.8 to 3.7 +/- 1.9 ng.ml-1 by 1.0 mg.kg-1 midazolam (P < 0.05). Flumazenil did not antagonize the relaxant effect of midazolam but reversed the inhibitory effect of midazolam on histamine-induced adrenaline release.

CONCLUSION

Midazolam has a spasmolytic effect on constricted airways but this bronchodilatation was not reversed by flumazenil.

New technique for time series analysis combining the maximum entropy method and non-linear least squares method: its value in heart rate variability analysis

A new technique for time series analysis, which is a combination of the maximum entropy method (MEM) for spectral analysis and the non-linear least squares method (LSM) for fitting analysis, is described. In this technique, the MEM power spectral density (MEMPSD) is calculated using a very large lag that could diminish the lag dependence of dominant periods estimated by the MEM analysis. The validity of this large lag is confirmed by the LSM, given that the ten dominant MEM periods are known quantities. To validate the MEM plus LSM technique, it is compared with autoregressive (AR) modelling, by analysing heart rate variability under pharmacological interventions (phenylephrine and trinitroglycerine), using 16 young males. The results indicate that the MEMPSD, when compared with the ARPSD, has numerous periods that could reproduce the original time series much more accurately, as revealed by the LSM analysis. However, both the low- and high-frequency powers with MEMPSD and ARPSDs shift in the expected directions in accordance with the pharmacological effects on the cardiovascular system. The implications of these results are discussed from the theoretical and practical standpoints of the MEM plus LSM technique, compared with AR modelling.

In vivo direct measurement of the bronchodilating effect of sevoflurane using a superfine fiberoptic bronchoscope: comparison with enflurane and halothane

OBJECTIVES

Although volatile anesthetics have been shown to have spasmolytic effects on constricted airways, most previous studies were performed to assess bronchodilation with indirect methods such as measurement of airway resistance, whose reliability is controversial. As the authors have developed a new direct method using a superfine fiberoptic bronchoscope (SFB) and confirmed the accuracy of this method, this study assessed the spasmolytic effect of sevoflurane (S) as compared with enflurane (E) and halothane (H).

DESIGN

Open-labeled, randomized study.

SETTING

The study protocol was approved by the Animal Care Committee in a school of medicine.

PARTICIPANTS

Twenty-two mongrel dogs.

INTERVENTIONS

The dogs were anesthetized with pentobarbital, IV, paralyzed with pancuronium, and the lungs were mechanically ventilated. The endotracheal tube had an additional lumen to insert the SFB (outer diameter 2.2 mm). The tip of the SFB was located between a second and third bronchial bifurcation to continuously monitor the bronchial cross-sectional area (BCA) of third or fourth generation bronchi. The BCA was printed out by videoprinter at the end of expiration and was calculated on a Macintosh IIci computer using an NIH (National Institutes of Health) image program. Bronchoconstriction was produced with histamine (HA: 10 micrograms/kg + 500 micrograms/kg/hr). In the first protocol, 4 mongrel dogs were used to assess the accuracy of the new method. BCA was measured 30 and 60 minutes after the placement of the SFB and also 30 and 60 minutes after the start of the histamine (HA) infusion. Arterial blood (4 mL) was collected at 30 and 60 minutes after placement of the SFB to measure the plasma concentration of catecholamines with gas chromatographic mass spectrometry. In the second protocol, 18 dogs were randomly allocated to 3 groups of 6 each: group S, group E, and group H. Thirty minutes after the start of the HA infusion, the dogs subsequently inhaled the following concentrations of S, E, or H for 15 minutes: 0.2, 0.4, 0.8, and 1.6 minimum alveolar concentrations. The BCA was assessed before and 30 minutes after the start of HA and at the end of the inhalation period of each concentration.

MEASUREMENTS AND MAIN RESULTS

In the first study, no significant differences in the BCA were found between 30 and 60 minutes after the placement of the SFB and between 30 and 60 minutes after the start of HA. The plasma concentrations of norepinephrine and epinephrine changed from 138 +/- 45 and 162 +/- 18 to 188 +/- 48 and 136 +/- 18 pg/mL, respectively. In the second study, all volatile anesthetics significantly increased the BCA in a dose-dependent manner. There was no significant difference among the three groups.

CONCLUSION

As the BCA did not change in the first study, the tip of the SBF could be well fixed, and the 30-minute interval is long enough for the HA infusion to produce stable bronchoconstriction. The plasma catecholamine concentrations suggest that the pentobarbital anesthesia was deep enough to inhibit the direct irritant effect of the endotracheal tube and the SFB on the airway. This new direct method indicates that S dilates HA-constricted proximal airway with the same potency as E and H.

[Preliminary screening for antiviral AIDS drugs. VI. Report for fiscal year 1993]

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 138 samples tested, two were found to inhibit the growth of HIV in vitro. Neither of the positive samples has hopeful signs, as the ranges of effective doses of the samples are very narrow.

[Changes in rectal temperature during tympanoplasty under general anesthesia]

We measured rectal temperature of 35 patients who underwent tympanoplasty under various types of general anesthesia. They were allocated at random to three groups according to the types of general anesthesia; 10 patients of enflurane-N2O (enflurane group); 10 patients of neuroleptic anesthesia with droperidol, pentazocine-N2O (NLA group); 15 patients of total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK group). After the induction of anesthesia, their rectal temperature was continuously monitored with an electric thermometer of NEC San-ei throughout the surgical procedure. Increase in rectal temperature was observed in all three groups, and increase in DFK group was significant compared with other two groups. It is possible that the significant increase in rectal temperature in DFK group is supposedly due to normally maintained hypothalamic thermoregulatory function as well as direct surgical stimulation to central nervous system.

[Clinical study on intraoperative hyperketonemia in non-diabetic surgical patients under general anesthesia]

We measured plasma 3-hydroxybutyrate (3-OHBA) concentrations in 925 non-diabetic surgical patients who underwent various surgical procedures under various types of general anesthesia. Lactated Ringer's solution only was used as an intraoperative fluid. Among them, 46 patients (4.9%) developed high 3-OHBA levels of over 500 microM.l-1 during surgery. The causes of observed hyperketonemia would be surgical stress and preoperative fasting irrespective of 8 types of general anesthesia. Blood glucose, lactic acid, base excess and pH were not influenced by hyperketonemia. Prolonged recovery from anesthesia was not observed in any patients with hyperketonemia. Without any specific treatments, plasma 3-OHBA levels were unchanged or rather decreased in 70% of the patients whose 3-OHBA levels were over 500 microM. The results suggest that hyperketonemia below 500 microM.l-1 is not always disadvantageous in nondiabetic patients under general anesthesia.

[Clinical study on total intravenous anesthesia with droperidol, fentanyl, and ketamine--18. Effect on peripheral circulation as judged by core-peripheral temperature gradient]

Effect of total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK) on peripheral circulation was studied by examining core-peripheral temperature gradient in twenty five patients who underwent abdominal surgery. A core temperature probe was attached on the forehead and peripheral probe on the palm of the hand of the side on which the blood pressure cuff was not applied. The temperature gradient was less than three degrees centigrade in 60% of the patients and the gradient was significantly less as compared with that of isoflurane anesthesia even at 300 minutes after the start of surgical operation. This advantage would have been caused by such factors as circulatory stimulating effect of ketamine, sympathetic blocking effect by droperidol and adequate postoperative analgesia by fentanyl and norketamine, a metabolite of ketamine. The results suggest that DFK would exert a beneficial effect on peripheral circulation, particularly during prolonged surgical procedures.

Transforming activity of a synthetic c-Ha-ras gene containing O6-methylguanine in codon 12

A mutagenic DNA-adduct, O6-methylguanine, was introduced into codon 12 of the synthetic c-Ha-ras gene by cassette mutagenesis. Transfection of this modified ras gene into normal NIH3T3 cells by the calcium phosphate procedure resulted in significant induction of focus formation. The ras gene inserted into the transformed cells was found to have a G to A transition at the position of the modified base. These results indicate that an O6-methylguanine residue in DNA may lead to a mutation and be one cause of activation of the ras gene.

[Preliminary screening for antiviral AIDS drugs. II. Report on fiscal year 1989]

Preliminary screening for antiviral AIDS drugs was carried out using three different in vitro assay systems. Among 104 samples tested, six were found to inhibit the growth of HIV in vitro. Four of six were acidic polysaccharides of sea weed origin and one was a well-known anti HIV chemical whose anti-HIV activity has not been reported.

Pathogenesis of Vibrio parahaemolyticus: intraperitoneal and orogastric challenge experiments in mice

It has been noted that V. parahaemolyticus isolated from patients with food poisoning are almost always thermostable direct hemolysin (TDH)-positive, whereas, isolates from foods or environmental sources are usually TDH-negative. The virulence of V. parahaemolyticus in mice was examined by using intraperitoneal and orogastric challenge models, where the strains used were those isolated from patients and foods with food poisoning and included TDH-positive and -negative. The LD50 in mice was estimated to be approximately 10(7) in the former and 10(8) in the latter challenge model. In the mice killed by challenge, either intraperitoneal or orogastric, the following pathological changes were almost always observed: swelling, redness and fluid accumulation in the small intestine, particularly the upper part of it. Histologically, congestion, edema, and vacuolation were observed in mucosal and submucosal tissues; furthermore, ulceration at tips of some villi was noticed. The lethality and pathological finding in mice due to V. parahaemolyticus were demonstrated similarly in both challenge models and irrespective of the TDH phenotype of the strain used. It will be suggested that the findings in challenged mice may be attributed to enteropathogenic factor(s) other than TDH of V. parahaemolyticus.

Transformation of NIH3T3 cells with synthetic c-Ha-ras genes

Synthetic human c-Ha-ras genes in which amino acid codons were altered to those which are frequently used in highly expressed Escherichia coli genes were ligated to the 3'-end of Rous sarcoma virus long terminal repeat. When NIH3T3 cells were transfected with the plasmids having those genes with valine at codon 12, leucine at codon 61 or arginine at codon 61, transformants were efficiently produced. These results indicated that the synthetic c-Ha-ras genes are expressed in a mammalian system even though their codon usage is altered to correspond with that of E. coli. This expression vector system should be useful for studies on the structure-function relationships of c-Ha-ras, since the synthetic gene can be easily modified to have multiple base alterations, and can also be used simultaneously for the production of large amounts of p21 in E. coli for biochemical and biophysical studies.

Expression of hepatitis B virus middle and large surface antigen genes in Saccharomyces cerevisiae

The hepatitis B virus genome carries the surface antigen (SAg) gene and an open reading frame that encodes two SAg-related polypeptides: SAg with a 55-amino-acid N-terminal extension polypeptide and SAg with a 174-amino-acid N-terminal extension polypeptide. These are termed middle S and large S, respectively. These polypeptides or their glycosylated derivatives have been detected in Dane particles, but their chemical and biological properties have remained largely unknown because of their limited availability. We attempted to produce these proteins in Saccharomyces cerevisiae by placing the coding regions under the control of the promoter of the yeast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Yeast cells carrying middle S and large S coding sequences produced 33,000- and 42,000-dalton products, respectively, each of which reacted with anti-S antibody and bound to polymerized human serum albumin, in accordance with the known properties of pre-S proteins from particles in human sera (K. H. Heermann, U. Goldmann, W. Schwartz, T. Seyffarth, H. Baumgarten, and W. H. Gerlich, J. Virol. 52:396-402, 1984; A. Machida, S. Kishimoto, H. Ohnuma, K. Baba, Y. Ito, H. Miyamoto, G. Funatsu, K. Oda, S. Usuda, S. Togami, T. Nakamura, Y. Miyakawa, and M. Mayumi, Gastroenterology 86:910-918, 1984). The middle S polypeptide is glycosylated and can be assembled into particles whose size and density are similar to those of SAg. However, this polypeptide was highly susceptible to proteolytic degradation into 29,000- and 26,000-dalton polypeptides, of which only the former retained the binding activity to polymerized albumin. The large S polypeptides are nonglycosylated, relatively stable, and do not seem to assemble into particles by themselves.

Increase in intradermal vascular permeability caused by pertussis toxin from Bordetella pertussis

Rabbits that were injected intradermally with pertussis toxin (PT), produced from Bordetella pertussis, showed slight edema and erythema at the injection sites, but not hemorrhage nor necrosis. The edema lesions were stained blue by the intravenous injection of Pontamine Sky Blue 6B dye, suggesting that PT caused increased vascular permeability, similarly to the permeability factor (PF) of cholera toxin. The reaction of the PF of PT could be determined by measuring the diameter of the blue area. The diameter of the blue area bore a good linear relationship to the logarithm of the dose of PT. The activity of the PF was neutralized by anti-PT rabbit serum. Detoxification of PT with formalin did not increase the vascular permeability, but reverted pertussis toxoid showed a PF reaction in proportion to the reverted leukocytosis-promoting and histamine-sensitizing activities of PT. The supernate of a Bordetella pertussis culture also induced a PF reaction and the reaction could be made clear by heating the supernate at 56 C for 30 min, but the supernate of Bordetella bronchiseptica did not induce the reaction at all.

Expression of hepatitis B virus core antigen gene in Saccharomyces cerevisiae: synthesis of two polypeptides translated from different initiation codons

Two recombinant plasmids were constructed that allow expression of the hepatitis B core (HBc) antigen gene in the yeast Saccharomyces cerevisiae under the control of the repressible acid phosphatase promoter. One plasmid was designed to produce polypeptide I, which consists of 183 amino acids, and the other plasmid was designed to produce polypeptide II, which has an additional 29-amino-acid sequence at the amino terminus of polypeptide I. The viral genome may code for either one or both of these two polypeptides, depending upon the selection of initiation codons. Both polypeptides produced in yeast cells reacted with anti-HBc antibody and were assembled into spherical particles approximately 27 nm in diameter. Particles made of polypeptide I were stable, whereas those made of polypeptide II readily dissociated when exposed to high salt levels. The antigenicity of the HBc (as defined by its reactivity to anti-HBc antibody in the reversed passive hemagglutination assay) disappeared as the particle dissociated, leaving materials that sedimented slowly and that reacted to anti-hepatitis B e antibody. These observations strongly suggest that native viral cores are mostly (if not all) made of polypeptide I, because it is reasonably stable, and that the N-terminal portion of this polypeptide has some, but not a profound, influence on the assembly of polypeptides into particles.

Immunogenicity of purified glycoprotein gB of herpes simplex virus

The efficacy of a herpes simplex virus (HSV) component vaccine consisting of viral glycoprotein gB was examined in a mouse system. Immunization of mice with HSV type 1 (HSV-1) gB emulsified in Freund's complete adjuvant or with HSV-1 gB adsorbed to aluminum gel was fully protective against subsequent challenge with HSV-1 or HSV type 2. Latent infection in the trigeminal ganglion was also prevented by immunization with gB.

Expression of herpes simplex virus glycoprotein B gene in yeast

The DNA sequence coding for herpes simplex virus type 1 glycoprotein B was placed under control of the acid phosphatase promoter of the yeast Saccharomyces cerevisiae in a plasmid capable of replicating in both yeast and Escherichia coli. Yeast transformed by the plasmid synthesized immunologically active glycoprotein B polypeptide.

Passive immunization of mice with monoclonal antibodies to glycoprotein gB of herpes simplex virus

To investigate the protective ability of monoclonal antibodies (MCAs) to viral glycoprotein in herpes simplex virus (HSV) infection, athymic nude mice were inoculated intracutaneously with HSV type-1 (HSV-1) in the midflank. Three hours after inoculation, one group of mice was passively immunized with one of a series of MCAs to glycoprotein gB of HSV-1, and a control group of mice was given phosphate buffered saline alone. The control mice died within 16 days after infection, whereas the mice passively immunized with any of the MCA showed suppressed development of skin lesions. Three of six mice given MCA failed to develop any visible lesions and no HSV could be isolated from the lumbar dorsal root ganglia of these mice 60 days after the challenge. BALB/c mice were also protected from infection with HSV type 2 by passive immunization with MCA to HSV-1 gB.

Two mammalian cell systems for propagation of the hepatitis B virus genome in extrachromosomal and chromosomally integrated states: production of the surface and e antigens

A recombinant plasmid consisting of (i) the entire genome of hepatitis B virus (HBV) DNA, (ii) the replication origin of SV40 virus, and (iii) a deletion derivative of pBR322 was introduced either into COS cells of monkey origin which constitutively express SV40 large T antigen, or into thymidine kinase(TK)-deficient mouse L cells together with the TK DNA of Herpes simplex virus. In the COS cell system, the transfecting recombinant DNA replicates via SV40 origin and is maintained in an autonomously replicating state. The cells carrying these extrachromosomal elements express the hepatitis B surface antigen gene at moderate rate, and release the products into the culture medium. However, neither core antigen nor e antigen expression was detected in this system. In the L cell system, the transformed L cells carry the recombinant DNA in a chromosomally integrated state. Such cells express the surface antigen gene at high rate, and release the products into the culture medium. This system also excretes the e antigen into the culture medium. The core antigen was not detected.

An improved method for preparation of C1-depleted serum and its application to hemolytic assay of C1

Serum depleted of the first component of complement (C1D) was prepared by treating fresh human serum with Sepharose-IgG in the presence of triethylenetetramine-N,N,N',N'',N''',N'''-hexa-acetic acid and di-isopropyl fluorophosphate at acidic pH (5.2). The total hemolytic activity of this C1D could be increased to approximately 75% of that of the original serum by the addition of excess purified C1. A linear relation was obtained on determination of C1 hemolytic activity using C1D, and the C1 titers of sera from patients measured by this simple method showed a good correlation with those measured using intermediate cells.

Distributions and Recoveries of Complement Components during Cold Ethanol Fractionation of Human Plasma

The distributions and recoveries of the hemolytic activities and quantities of protein of complement components during cold ethanol fractionation were studied. Most of the components were recovered in Cohn's fraction III, with slight activities in fractions I and IV. The hemolytic activities of C1 and C5 were recovered in high yields in fraction III. The recoveries of activities of late components of complement (C6-C9) in fraction II + III were also high. These results suggest that many complement components can be isolated from Cohn's ethanol fractions.