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.

Association Between Preoperative Neuropathic Pain and Patient Reported Outcome Measures After Cervical Spinal Cord Decompression Surgery

STUDY DESIGN

A prospective observational study.

OBJECTIVE

To evaluate the impact on surgical outcomes of preoperative neuropathic pain (NeP) assessed by the painDETECT questionnaire (PDQ) administered to participants undergoing cervical decompression surgery for degenerative cervical myelopathy (DCM).

METHODS

Participating patients were separated into the Non-NeP group (preoperative PDQ score ≤ 12), and NeP group (score ≥ 13). They were asked to complete a booklet questionnaire, including NRS for pain, the Short Form-12 for PCS and MCS, EQ-5D, NDI, and COMI-Neck, at baseline and 1 year after surgery. The JOA score for DCM and radiological changes were also evaluated. Propensity scores were used for the generalized linear model to adjust the patients' backgrounds.

RESULTS

Of the 116 patients recruited, 105 completed the one-year follow-up. In this study, 31 (29.5%) and 74 (70.5%) patients in the NeP and non-NeP groups, respectively, were compared. Except for the higher female ratio in the NeP group (64.6% vs 33.2%, P = .009), preoperative demographic data and surgical factors were not significantly different between both groups. The NeP group showed greater neck/arm/hand NRS scores and worse pre- and postoperative NDI/EQ-5D/COMI-Neck scores at baseline and 1 year after surgery, but this was not significant in the MCS/PCS and JOA scores. Change scores of neck/arm/hand NRS scores and MCS/PCS/NDI/EQ-5D/COMI-Neck scores were not significant between both groups.

CONCLUSIONS

The preoperative NeP, assessed by PDQ, was observed in approximately 30% of patients with DCM who underwent decompression surgery. The presence of NeP was associated with worse pre- and postoperative NDI/EQ-5D/COMI-Neck scores.

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.

A new surgical method to treat intracanal lumbar disc herniation using the unilateral biportal endoscopic transforaminal approach: patient series

BACKGROUND

Unilateral biportal endoscopic lumbar discectomy (UBELD) is a new minimally invasive spine surgery. The purpose of this study is to describe a new surgical method to treat intracanal lumbar disc herniation (LDH) using the unilateral biportal endoscopic transforaminal approach (UBE-TFA). The first 15 patients who had undergone UBELD for single-level LDH were included in this study. Operative time, intraoperative blood loss, postoperative stay, and intraoperative complications were recorded. The Oswestry Disability Index (ODI), numeric rating scale (NRS) score for leg pain, and modified MacNab criteria were assessed at 3 months postoperatively.

OBSERVATIONS

The mean operative time was 52.0 ± 13.8 minutes. The mean intraoperative blood loss was 10.5 ± 10.2 mL. The mean postoperative stay was 1.1 ± 0.3 days. There were no complications. The postoperative mean ODI was significantly improved from 44.9 ± 14.4 to 7.7 ± 11.2 at the final follow-up (p < 0.001). There was a significant decrease in the postoperative mean NRS score for leg pain, from 6.1 ± 1.9 to 0.8 ± 1.3 at the final follow-up (p < 0.001). Based on the modified MacNab criteria, good to excellent results were obtained in 86.7% of the patients.

LESSONS

We considered UBELD-TFA as not only one of the promising surgical methods for UBELD, but also a new surgical implementation of the TFA.

Does surgical site infection affect patient-reported outcomes after spinal surgery? A multicenter cohort study

BACKGROUND

Surgical site infections are common in spinal surgeries. It is uncertain whether outcomes in spine surgery patients with vs. without surgical site infection are equivalent. Therefore, we assessed the effects of surgical site infection on postoperative patient-reported outcomes.

METHODS

We enrolled patients who underwent elective spine surgery at 12 hospitals between April 2017 and February 2020. We collected data regarding the patients' backgrounds, operative factors, and incidence of surgical site infection. Data for patient-reported outcomes, namely numerical rating scale, Neck Disability Index/Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 1 year postoperatively. We divided the patients into with and without surgical site infection groups. Multivariate logistic regression analyses were performed to identify the risk factors for surgical site infection. Using propensity score matching, we obtained matched surgical site infection-negative and -positive groups. Student's t-test was used for comparisons of continuous variables, and Pearson's chi-square test was used to compare categorical variables between the two matched groups and two unmatched groups.

RESULTS

We enrolled 8861 patients in this study; 74 (0.8 %) developed surgical site infections. Cervical spine surgery and American Society of Anesthesiologists physical status classification ≥3 were identified as risk factors; microendoscopy was identified as a protective factor. Using propensity score matching, we compared surgical site infection-positive and -negative groups (74 in each group). No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the groups. When comparing preoperative with postoperative pain and dysesthesia, statistically significant improvement was observed for both variables in both groups (p < 0.01 for all variables). No significant differences were observed in postoperative outcomes between the matched surgical site infection-positive and -negative groups.

CONCLUSIONS

Patients with surgical site infections had comparable postoperative outcomes to those without surgical site infections.

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.

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.

Runx2 and Runx3 differentially regulate articular chondrocytes during surgically induced osteoarthritis development

The Runt-related transcription factor (Runx) family plays various roles in the homeostasis of cartilage. Here, we examined the role of Runx2 and Runx3 for osteoarthritis development in vivo and in vitro. Runx3-knockout mice exhibited accelerated osteoarthritis following surgical induction, accompanied by decreased expression of lubricin and aggrecan. Meanwhile, Runx2 conditional knockout mice showed biphasic phenotypes: heterozygous knockout inhibited osteoarthritis and decreased matrix metallopeptidase 13 (Mmp13) expression, while homozygous knockout of Runx2 accelerated osteoarthritis and reduced type II collagen (Col2a1) expression. Comprehensive transcriptional analyses revealed lubricin and aggrecan as transcriptional target genes of Runx3, and indicated that Runx2 sustained Col2a1 expression through an intron 6 enhancer when Sox9 was decreased. Intra-articular administration of Runx3 adenovirus ameliorated development of surgically induced osteoarthritis. Runx3 protects adult articular cartilage through extracellular matrix protein production under normal conditions, while Runx2 exerts both catabolic and anabolic effects under the inflammatory condition.

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.

RSPO2 defines a distinct undifferentiated progenitor in the tendon/ligament and suppresses ectopic ossification

Ectopic endochondral ossification in the tendon/ligament is caused by repetitive mechanical overload or inflammation. Tendon stem/progenitor cells (TSPCs) contribute to tissue repair, and some express lubricin [proteoglycan 4 (PRG4)]. However, the mechanisms of ectopic ossification and association of TSPCs are not yet known. Here, we investigated the characteristics of Prg4-positive (⁺) cells and identified that R-spondin 2 (RSPO2), a WNT activator, is specifically expressed in a distinct Prg4⁺ TSPC cluster. The Rspo2⁺ cluster was characterized as mostly undifferentiated, and RSPO2 overexpression suppressed ectopic ossification in a mouse Achilles tendon puncture model via chondrogenic differentiation suppression. RSPO2 expression levels in patients with ossification of the posterior longitudinal ligament were lower than those in spondylosis patients, and RSPO2 protein suppressed chondrogenic differentiation of human ligament cells. RSPO2 was induced by inflammatory stimulation and mechanical loading via nuclear factor κB. Rspo2⁺ cells may contribute to tendon/ligament homeostasis under pathogenic conditions.

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.

Postoperative outcomes after degenerative lumbar spine surgery in rheumatoid arthritis patients -a propensity score-matched analysis

Background

Although treatment options for rheumatoid arthritis (RA) have evolved significantly since the introduction of biologic agents, degenerative lumbar disease in RA patients remains a major challenge. Well-controlled comparisons between RA patients and their non-RA counterparts have not yet been reported. The objective of the present study was to compare postoperative outcomes of lumbar spine surgery between RA and non-RA patients by a retrospective propensity score-matched analysis.

Methods

Patients who underwent primary posterior spine surgery for degenerative lumbar disease in our prospective multicenter study group between 2017 and 2020 were enrolled. Demographic data including age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status classification, diabetes mellitus, smoking, steroid usage, number of spinal levels involved, and preoperative patient-reported outcome (PRO) scores (numerical rating scale [NRS] for back pain and leg pain, Short Form-12 physical component summary [PCS], EuroQOL 5-dimension [EQ-5D], and Oswestry Disability Index [ODI]) were used to calculate a propensity score for RA diagnosis. One-to-one matching was performed and 1-year postoperative outcomes were compared between groups.

Results

Among the 4567 patients included, 90 had RA (2.0%). RA patients in our cohort were more likely to be female, with lower BMI, higher ASA grade and lower current smoking rate than non-RA patients. Preoperative NRS scores for leg pain, PCS, EQ-5D, and ODI were worse in RA patients. Propensity score matching generated 61 pairs of RA and non-RA patients who underwent posterior lumbar surgery. After background adjustment, RA patients reported worse postoperative PCS (28.4 vs. 37.2, p = 0.008) and EQ-5D (0.640 vs. 0.738, p = 0.03), although these differences were not significant between RA and non-RA patients not on steroids.

Conclusions

RA patients showed worse postoperative quality of life outcomes after posterior surgery for degenerative lumbar disease, while steroid-independent RA cases showed equivalent outcomes to non-RA 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.

Influence of Perioperative Antithrombic Agent Discontinuation in Elective Posterior Spinal Surgery: A Propensity-Score-Matched Analysis

OBJECTIVE

To investigate the influence of perioperative antithrombotic agent (antiplatelet agents and anticoagulants) discontinuation in elective posterior spinal surgery in terms of bleeding complications, such as epidural hematoma and postoperative thromboembolism.

METHODS

We enrolled patients undergoing elective posterior spinal surgery at 9 hospitals between April 2017 and August 2020. We collected data regarding patient baseline characteristics, surgical details, intraoperative estimated blood loss, and postoperative complication rates, including epidural hematoma and thromboembolism. We divided the patients into a discontinuation group, in which antithrombic agents were discontinued perioperatively, and a control group without antithrombic agents. Propensity scores for taking any antithrombic agents were calculated, with 1-to-1 matching based on the estimated propensity scores to adjust for patient baseline characteristics and surgical details. Intraoperative estimated blood loss and 30-day postoperative complication rates were compared between the groups.

RESULTS

We enrolled 9853 patients, including 1123 patients (11.4%) who discontinued antithrombic agents perioperatively. One-to-one propensity score matching yielded 1111 pairs with and without antithrombic agents. Intraoperative estimated blood loss per 10 minutes (8.2 mL vs. 8.9 mL) and the incidence of epidural hematoma requiring revision (0.97% vs. 0.72%) were similar between the groups. Although postoperative cardiac events and stroke were observed only in the discontinuation group (0.27% and 0.09%, respectively), these incidences were not significantly different between the groups.

CONCLUSIONS

Perioperative antithrombic agent discontinuation in elective posterior spinal surgery normalized the intraoperative bleeding tendency and the incidence of postoperative epidural hematoma and did not influence in a significative way the incidence of postoperative thromboembolism.

The Impact of Cefazolin Shortage on Surgical Site Infection Following Spine Surgery in Japan

STUDY DESIGN

Retrospective study using prospectively collected data.

OBJECTIVE

This study aimed to investigate the effect of alternative antimicrobial prophylaxis agents on surgical site infections (SSIs) after spine surgery.

SUMMARY OF BACKGROUND DATA

Although the use of alternative antimicrobial prophylaxis agents might have a negative effect on SSI prevention, their association with SSI risk in spine surgery remains unclear.

METHODS

We used the registry data of consecutive patients undergoing spine surgery from April 2017 to January 2020 in four institutions participating in the University of Tokyo Spine Group. Before March 2019, all institutions used cefazolin for antimicrobial prophylaxis. After March 2019, the institutions used broad-spectrum beta-lactam agents as an alternative due to a cefazolin shortage in Japan.

RESULTS

Among the 3841 enrolled patients (2289 males), 2024 received cefazolin and 1117 received alternative agents. The risk of reoperation for deep SSI within 30 days of spine surgery was significantly higher in the alternative antimicrobial prophylaxis agent group (adjusted odds ratio [aOR] 1.96; 95% confidence interval [CI], 1.15-3.35; P = 0.014). In subgroup analyses, the SSI risk was significantly higher in the thoracolumbar surgery group (aOR 1.98; 95% CI, 1.06-3.73; P = 0.03). A nonsignificant consistent trend was found in all other subgroups: posterior decompression (aOR 1.91; 95% CI, 0.86-4.21; P = 0.11); posterior fixation (aOR 2.05; 95% CI, 0.99-4.24; P = 0.05); and cervical spine surgery (aOR 2.30; 95% CI, 0.82-6.46; P = 0.11).

CONCLUSION

Alternative antimicrobial prophylaxis agents increased the risk of reoperation for SSI after spine surgery compared with cefazolin. Our study supports the current practice of using first-generation cephalosporins as first-line antimicrobial prophylaxis agents in spine surgery as recommended in multiple guidelines.Level of Evidence: 3.

Involvement of Transient Receptor Potential Vanilloid Channel 2 in the Induction of Lubricin and Suppression of Ectopic Endochondral Ossification in Mouse Articular Cartilage

OBJECTIVE

Transient receptor potential vanilloid channel 2 (TRPV2) is a Ca²⁺ -permeable channel and plays a role in mediating intracellular Ca²⁺ current via mechanical stimuli. This study was undertaken to examine the expression and role of TRPV2 in adult articular cartilage and the development of osteoarthritis (OA).

METHODS

We examined TRPV2 expression in mouse and human articular cartilage. We analyzed the development of OA in Col2a1-Cre^ERt2 ;Trpv2^fl/fl mice and Trpv2^fl/fl littermates in the resection of the medial meniscus and medial collateral ligament model (n = 5 each), the destabilization of the medial meniscus model (n = 5 each), and the aging mouse model (n = 8-9 each). We examined marker protein expression in these joints, Ca²⁺ influx by mechanical stimuli, and downstream pathways in vitro.

RESULTS

TRPV2 was expressed in mouse and human articular cartilage and ectopic ossification lesions. In all mouse models of OA examined, Col2a1-Cre^ERt2 ;Trpv2^fl/fl mice were observed to have enhanced degradation of articular cartilage accompanied by decreased expression of lubricin/Prg4, and marked formation of periarticular ectopic ossification. Mechanical stress-induced Ca²⁺ influx was decreased by Trpv2 knockout (KO). Prg4 induction by fluid-flow shear stress was diminished in Trpv2-KO mouse chondrocytes, and this was mediated by the Ca²⁺ /calmodulin-dependent protein kinase kinase-cyclic AMP response element binding protein axis. Hypertrophic differentiation was enhanced in Trpv2-KO mouse chondrocytes. Increased activity of calcineurin and nuclear translocation of nuclear factor in activated T cells 1 induced by fluid-flow shear stress or TRP agonist treatment was reversed by Trpv2 knockout.

CONCLUSION

Our findings demonstrate regulation of articular cartilage by TRPV2 through Prg4 induction and suppression of ectopic ossification.

Risk factors for worsening sexual function after lumbar spine surgery and characteristics of non-responders to the questionnaire of sex life

PURPOSE

To precisely assess the Oswestry Disability Questionnaire (ODQ) and its total score (Oswestry Disability Index: ODI) and reveal characteristics of non-responders of the 8th item of ODQ (ODI-8) relating to sexual function. Furthermore, we evaluated risk factors for aggravation of postoperative sexual function.

METHODS

We enrolled patients undergoing lumbar spine surgery at eight hospitals between April 2017 and November 2018. Patients' background data and operative factors were collected. We also assessed pain or dysesthesia (lower back, buttock, leg, and plantar area) on a numerical rating scale, EuroQol 5 Dimension, core outcome measures index back, and ODI before and 1 year after surgery. Factor analysis was conducted for the ODQ. Non-responders of the ODI-8 were compared with full-responders using propensity score matching. Risk factors for worsening ODI-8 were evaluated by multivariate logistic regression analysis.

RESULTS

Of the 2,610 patients enrolled, 601 (23.0%) answered all but the ODI-8 item; these patients were likely to show better preoperative clinical symptoms than full-responders, even after adjusting for age and gender using propensity scores. Age, spinal deformity, and the American Society of Anesthesiologists physical status (ASA-PS) 3/4 were significant risk factors for postoperative aggravation of the ODI-8. Factor analysis revealed that the ODQ was composed of dynamic and static activities; the ODI-8 was considered a dynamic activity.

CONCLUSION

Almost a fourth of the patients skipped the ODI-8. Age, the presence of spinal deformity, and worse ASA-PS were found to be risk factors for postoperative aggravation of sexual function.

LEVEL OF EVIDENCE I

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

Lubricin Contributes to Homeostasis of Articular Cartilage by Modulating Differentiation of Superficial Zone Cells

Lubricin encoded by the proteoglycan 4 (Prg4) gene is produced from superficial zone (SFZ) cells of articular cartilage and synoviocytes, which is indispensable for lubrication of joint surfaces. Loss-of-function of human and mouse Prg4 results in early-onset arthropathy accompanied by lost SFZ cells and hyperplastic synovium. Here, we focused on increases in the thickness of articular cartilage in Prg4-knockout joints and analyzed the underlying mechanisms. In the late stage of articular cartilage development, the articular cartilage was thickened at 2 to 4 weeks and the SFZ disappeared at 8 weeks in Prg4-knockout mice. Similar changes were observed in cultured Prg4-knockout femoral heads. Cell tracking showed that Prg4-knockout SFZ cells at 1 week of age expanded to deep layers after 1 week. In in vitro experiments, overexpression of Prg4 lacking a mucin-like domain suppressed differentiation of ATDC5 cells markedly, whereas pellets of Prg4-knockout SFZ cells showed enhanced differentiation. RNA sequencing identified matrix metalloproteinase 9 (Mmp9) as the top upregulated gene by Prg4 knockout. Mmp9 expressed in the SFZ was further induced in Prg4-knockout mice. The increased expression of Mmp9 by Prg4 knockout was canceled by IκB kinase (IKK) inhibitor treatment. Phosphorylation of Smad2 was also enhanced in Prg4-knockout cell pellets, which was canceled by the IKK inhibitor. Expression of Mmp9 and phosphorylated Smad2 during articular cartilage development was enhanced in Prg4-knockout joints. Lubricin contributes to homeostasis of articular cartilage by suppressing differentiation of SFZ cells, and the nuclear factor-kappa B-Mmp9-TGF-β pathway is probably responsible for the downstream action of lubricin. © 2020 American Society for Bone and Mineral Research (ASBMR).

Association Between Normothermia at the End of Surgery and Postoperative Complications Following Orthopedic Surgery

BACKGROUND

Maintaining perioperative normothermia is recommended by recent guidelines for the prevention of surgical site infections (SSIs). However, the majority of supporting data originates outside the field of orthopaedic surgery.

METHODS

The effect of normothermia was explored using the prospectively collected data of consecutive patients who underwent single-site surgery in 7 tertiary referral hospitals between November 2013 and July 2016. SSIs, urinary tract infections (UTIs), respiratory tract infections (RTIs), cardiac and cerebral events (CCE), and all-cause mortality rates within 30 days after surgery were compared between patients with normothermia (body temperature ≥36°C) and those with hypothermia (<36°C) at the end of surgery, after closure. Multivariable adjusted and inverse-probability weighted regression analyses were performed.

RESULTS

The final cohort included 8841 patients. Of these, 11.4% (n = 1008) were hypothermic. More than 96% were evaluated in person by the physicians. After adjusting for multiple covariates, normothermia was not significantly associated with SSIs (adjusted odds ratio [aOR] 1.18, 95% confidence interval [CI] 0.59-2.33), UTIs (aOR 1.14, 95% CI 0.66-1.95), RTIs (aOR 0.60, 95% CI 0.31-1.19), or CCE (aOR 0.53, 95% CI 0.26-1.09). In contrast, normothermia was associated with a lower risk of 30-day mortality (aOR 0.26, 95% CI 0.11-0.64; P < .01; weighted hazard ratio 0.21, 95% CI 0.07-0.68; P = .002). In a subgroup analysis, normothermia was associated with reduced mortality in all types of surgical procedures.

CONCLUSIONS

Whereas our findings suggest no clear association with SSI risks following orthopedic surgery, our study supports maintaining perioperative normothermia, as it is associated with reduced 30-day mortality.

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.

Impact of technically qualified surgeons on laparoscopic colorectal resection outcomes: results of a propensity score-matching analysis

Background

The Endoscopic Surgical Skill Qualification System (ESSQS) was introduced in Japan to improve the quality of laparoscopic surgery. This cohort study investigated the short‐ and long‐term postoperative outcomes of colorectal cancer laparoscopic procedures performed by or with qualified surgeons compared with outcomes for unqualified surgeons.

Methods

All laparoscopic colorectal resections performed from 2010 to 2013 in 11 Japanese hospitals were reviewed retrospectively. The procedures were categorized as performed by surgeons with or without the ESSQS qualification and patients' clinical, pathological and surgical features were used to match subgroups using propensity scoring. Outcome measures included postoperative and long‐term results.

Results

Overall, 1428 procedures were analysed; 586 procedures were performed with ESSQS‐qualified surgeons and 842 were done by ESSQS‐unqualified surgeons. Upon matching, two cohorts of 426 patients were selected for comparison of short‐term results. A prevalence of rectal resection (50·3 versus 40·5 per cent; P < 0·001) and shorter duration of surgery (230 versus 238 min; P = 0·045) was reported for the ESSQS group. Intraoperative and postoperative complication and reoperation rates were significantly lower in the ESSQS group than in the non‐ESSQS group (1·2 versus 3·6 per cent, P = 0·014; 4·6 versus 7·5 per cent, P = 0·025; 1·9 versus 3·9 per cent, P = 0·023, respectively). These findings were confirmed after propensity score matching. Cox regression analysis found that non‐attendance of ESSQS‐qualified surgeons (hazard ratio 12·30, 95 per cent c.i. 1·28 to 119·10; P = 0·038) was independently associated with local recurrence in patients with stage II disease.

Conclusion

Laparoscopic colorectal procedures performed with ESSQS‐qualified surgeons showed improved postoperative results. Further studies are needed to investigate the impact of the qualification on long‐term oncological outcomes.

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.

Effect of depression and anxiety on health-related quality of life outcomes and patient satisfaction after surgery for cervical compressive myelopathy

OBJECTIVE

Preoperative mood disorders such as depression and anxiety are known to be associated with poor health-related quality of life (HRQOL) outcomes after lumbar spine surgery. However, the effects of preoperative depression and anxiety on postoperative HRQOL outcomes and patient satisfaction in cervical compressive myelopathy are yet to be clarified. This study aimed to investigate the effect of depression and anxiety on HRQOL outcomes and patient satisfaction following surgery for cervical compressive myelopathy.

METHODS

The authors reviewed the cases of all consecutive patients with cervical compressive myelopathy who had undergone surgical treatment in the period between January 2012 and March 2017 at their institution. Using the Hospital Anxiety and Depression Scale (HADS), the authors classified patients as depressed (HADS-D+) or not depressed (HADS-D-) and anxious (HADS-A+) or not anxious (HADS-A-). Patient HRQOL was evaluated preoperatively and at the end of at least 1 year after surgery using the physical and mental component summaries of the SF-12 Health Survey, EQ-5D (EuroQol health survey of five dimensions), Neck Disability Index, and Japanese Orthopaedic Association scale. Patient satisfaction was evaluated on the basis of a seven-item questionnaire and divided into two categories: satisfied and dissatisfied. Preoperative HRQOL statuses, postoperative improvements in HRQOL outcomes, and patient satisfaction were compared between the groups.

RESULTS

Among the 121 patients eligible for inclusion in the study, there were 69 patients (57.0%) without depression (HADS-D-) and 52 (43.0%) with depression (HADS-D+) and 82 patients (67.8%) without anxiety (HADS-A-) and 39 (32.2%) with anxiety (HADS-A+). All patients who completed both the preoperative and postoperative questionnaires had significant postoperative improvements in all HRQOL outcomes. The HADS-D+ and HADS-A+ patients had poorer preoperative HRQOL statuses than the HADS-D- and HADS-A- patients, respectively. However, statistically significant improvements in all HRQOL outcomes were observed in both HADS-D+ and HADS-A+ patients. Patient satisfaction was comparable between the HADS-D or HADS-A groups.

CONCLUSIONS

Cervical compressive myelopathy patients with preoperative depression or anxiety according to the HADS tool had worse preoperative HRQOL statuses. However, patients with cervical compressive myelopathy showed significant improvements in HRQOL outcomes and had sufficient levels of satisfaction after surgery regardless of the presence of preoperative depression or anxiety.

Adaptation and limitation of anterior column reconstruction for pyogenic spondylitis in lower thoracic and lumbar spine

BACKGROUND

Surgical strategy for pyogenic spondylitis is controversial when vertebral body erosion is severe. Radical debridement and anterior column reconstruction is indicated for the purpose of early ambulatory to prevent secondary complication for long bed rest. However, such aggressive debridement and risk of perioperative complications are trade-off. The purpose of this study was to evaluate the risk factor of poor prognosis after anterior column debridement and reconstruction for pyogenic spondylitis in lower thoracic and lumbar spine.

METHODS

We performed a retrospective review of 40 patients diagnosed with pyogenic spondylitis in lower thoracic and lumbar spine who were introduced to our institution due to losing ambulatory ability and underwent anterior column debridement and reconstruction between January 2008 and May 2016. After the patient population was split into a regaining ambulatory group (Group A; n = 23) and a poor prognosis group (Group P; n = 17), we used Fisher exact tests and t-tests as appropriate for univariate analyses to compare patient characteristics and outcomes between the 2 groups.

RESULTS

Univariate analysis showed that the significant variables were massive bleeding (>2000 ml) (P < 0.01), Charlson Comorbidity Index ≥3 (P = 0.01), and two-stage surgery needed (P = 0.04). Logistic regression analysis showed that the factors associated with poor prognosis were massive bleeding (Odds Ratio 11.9; 95% confidence interval 1.8 to 119.7; P = 0.04).

CONCLUSIONS

Massive bleeding was associated with poor prognosis after debridement followed by anterior column reconstruction for pyogenic spondylitis in lower thoracic and lumbar spine.

Quantitative Blood Velocity Mapping in Glomerular Capillaries by in vivo Observation with an Intravital Videomicroscope

We have evaluated rat glomerular microcirculation under in-vivo condition with an intravital videomicroscope. To measure erythrocyte velocities, a line segment was set along the glomerular capillaries in time-sequential videotaped images and then a spatiotemporal image was constructed along that segment. The angle of striped pattern in the spatio-temporal image which reflects the erythrocyte velocity, was estimated to compute erythrocyte velocity vector mapping. We found that erythrocyte velocities in rat glomeruli were significantly faster in diabetic rats than in control rats (p <0.05). In conclusion, we have succeeded in quantitatively evaluating the in-vivo renal microcirculation with our videomicroscope system and by spatiotemporal image analyzing method.

Improvement of Thermal Insulation for Polyurethane Foam by the Conversion of Carbon Dioxide to an Organic Carbonate Compound

A new method to improve the thermal insulation of polyurethane rigid foam blown by a non-ozone depleting agent—an alternative to chlorofluorocarbon—has been developed. This method involves the reduction of the gas thermal conductivity for polyurethane foam by the conversion of gaseous carbon dioxide in the foam to an organic carbonate. We tried to perform the cyclization of carbon dioxide in foam with an epoxy compound, and then the reduction of the thermal conductivity of the polyurethane foam was ascertained as carbon dioxide was chemically fixed in the foam. Consequently, this method led to a reduction of about 10% in the thermal conductivity in comparison with that of the conventional foam including carbon dioxide. In addition, the degree of progress of reaction in the foam was investigated by a quantitative analysis of carbon dioxide, epoxide and the resulting cyclic carbonate in the polyurethane foam. It was observed that unnecessary reactions, which consumed epoxide other than for the fixation of carbon dioxide, existed in the process of urethane polymerization. The main unnecessary reaction was presumed to be a side reaction of epoxide with isocyanate. Furthermore, the unnecessary reactions were affected by the type of urethane catalyst, the selection of which has been of importance in this method.

The small heat shock proteins and their clients

Small heat shock proteins are ubiquitous proteins found throughout all kingdoms. One of the most notable features is their large oligomeric structures with conserved structural organization. It is well documented that small heat shock proteins can capture unfolding proteins to form stable complexes and prevent their irreversible aggregation. In addition, small heat shock proteins coaggregate with aggregation-prone proteins for subsequent, efficient disaggregation of the protein aggregates. The release of substrate proteins from the transient reservoirs, i.e. complexes and aggregates with small heat shock proteins, and their refolding require cooperation with ATP-dependent chaperone systems. The amphitropic small heat shock proteins were shown to associate with membranes, although they do not contain transmembrane domains or signal sequences. Recent studies indicate that small heat shock proteins play an important role in membrane quality control and thereby potentially contribute to the maintenance of membrane integrity especially under stress conditions.

Proinsulin C-peptide activates vagus efferent output in rats

The aim of this study was to examine the effect of proinsulin C-peptide on the autonomic nervous systems in rats. Intravenous administration of C-peptide gradually increased electrophysiological activity of the vagus nerves into the stomach and pancreas for at least 90 min. It also slightly increased gastric acid secretion that was suppressed by the treatment with atropine. Intraperitoneal injection of C-peptide did not affect the basal and stress-induced norepinephrine (NE) turnover rate, a biochemical index of sympathetic nerve activity. These results indicate that C-peptide increases parasympathetic nerve activity without affecting sympathetic nerve activity. This could explain, at least in part, the ameliorating effects of C-peptide on impaired cardiac autonomic nerve functions in patients with type 1 diabetes.

New animal models for encapsulating peritoneal sclerosis--role of acidic solution

OBJECTIVE

Encapsulating peritoneal sclerosis (EPS), in which all or part of the intestine is enveloped in a fibrous ball resembling a cocoon, is a serious complication of peritoneal dialysis (PD). The aim of the present study was to investigate whether pH-neutral or acidic dialysis solutions induce peritoneal fibrosis.

DESIGN

We divided 18 male Wistar-Kyoto (WKY) rats into three groups and dialyzed them with various solutions as follows: group I, 10 mL acidic dialysis solution (pH 3.8, containing 1.35% glucose), n = 6; group II, 10 mL pH 5.0 dialysis solution, n = 6; and group III, 10 mL neutral dialysis solution (pH 7.0), n = 6. Peritoneal catheters were inserted, and dialysis solution was injected every day for 40 days. At the end of the experiment, a peritoneal equilibration test (PET) was performed. Expression of mRNA of aquaporins 1 and 4 (AQP-1 and AQP-4) in the peritoneum were studied by semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS

In rats treated with pH 3.8 dialysis solution, necropsy findings revealed features identical to those of EPS. The typical appearance was of granulation tissue or fibrotic tissue (or both) covering multiple surfaces. Multiple adhesions were present. In microscopic examinations, peritoneal fibrosis and loss of mesothelium were found. In rats treated with pH 7.0 dialysis solution, no signs of EPS were seen. In rats treated with pH 5.0 dialysis solution, milder changes (subserosal thickening and partial adhesion of the peritonea) were observed. The mRNA of AQP-1 and AQP-4 were expressed in the peritonea of the rats. The expression of the AQPs was significantly suppressed in rats treated with pH 3.8 dialysis solution.

CONCLUSIONS

In rats, long-term intraperitoneal injection of acidic dialysis solution produced features typical of EPS in humans. Newly developed neutral dialysis solutions protected the against the development of EPS during peritoneal dialysis in rats.

Newly developed immobilized polymyxin B fibers improve the survival of patients with sepsis

BACKGROUND

Sepsis and septic shock are still major causes of morbidity and mortality in spite of the availability of powerful and broadly active antibiotics.

METHODS

A prospective, open and randomized trial of the effect of immobilized polymyxin fibers (PMX-F) on the survival of patients with sepsis throughout a follow-up period of 28 days or until discharge, if earlier, was carried out. Ninety-eight patients were included who met at least 4 of the criteria for systemic inflammatory response syndrome due to infection. The patients were classified into three groups based on their Acute Physiology and Chronic Health Evaluation (APACHE) II score.

RESULTS

The overall survival rate was significantly improved by using PMX-F compared to the control group (41 vs. 11%) (p = 0.002). In patients with an APACHE II score less than 20, treatment with PMX-F was shown to improve outcome (65 vs. 19%) (p = 0.01). In cases of more severe sepsis with an APACHE II score of 20-29, PMX-F still maintained efficacy in improving outcome (40 vs. 11%) (p = 0.04). However, PMX-F treatment did not improve the survival rate in patients with an APACHE II score of greater than 30 (survival rate 7 vs. 0%) (p = 0.59).

CONCLUSION

From these results, it is concluded that treatment with PMX-F in patients with sepsis is effective and prolongs the survival rate when applied at an early stage of sepsis. However, in severe sepsis, this therapy does not improve the survival rate.

Self-measured systolic blood pressure in the morning is a strong indicator of decline of renal function in hypertensive patients with non-diabetic chronic renal insufficiency

While blood pressure is a recognized major determinant of renal function deterioration, the role of self blood pressure measurement (BPM) in predicting the loss of renal function in hypertensive patients with chronic renal insufficiency (CRI) has not been adequately addressed. One hundred and thirteen patients (F/M: 46/67; 56 +/- 1 years) with CRI (mean serum creatinine: 1.87 +/- 0.08; range: 1.4 to 3.5 mg/dl; average urinary protein excretion: 1.2 +/- 0.2 g/24 hrs.) were followed for 3 years. The record of renal biopsy revealed that 74 patients had IgA nephropathy, 16 had chronic glomerulonephritis, and 6 had membranous nephropathy, while 17, unbiopsied patients had underlying renal disease of unknown origin. Self BPM were made at regular intervals throughout the course of the study. All recorded blood pressures were included in a stepwise multiple regression analysis in which the decline in GFR per year was the dependent variable. Patients were primarily treated with a combination of amlodipine (5 to 20 mg daily), a calcium antagonist, and benazepril (2.5 to 5 mg daily), an ACE inhibitor in an effort to reduce their blood pressure at the office to < 130/85 mmHg. The simple correlation between blood pressures (i.e., office, home morning and home evening) and the decline in GFR were all statistically significant. The correlation coefficients of determination for this model were as follows: r = 0.64 for home morning SBP; 0.43 for office SBP; 0.39 for office DBP; and 0.38 for home morning DBP. The level of urinary protein excretion did not correlate with the decline in GFR. These data suggest that self BPM improves prognostic ability in hypertensive patients with CRI.

Renin-angiotensin system plays an important role in the regulation of water transport in the peritoneum

The present study was carried out to investigate changes in the expression of aquaporins (AQPs) in the peritoneum. The effects of the renin-angiotensin system on the expression of AQPs with and without angiotensin converting enzyme inhibitor (ACEI) or angiotensin II type 1a receptor blocker (ARB) were then examined. We divided 20 male Wistar Kyoto (WKY) rats into four groups, dialyzed with these solutions: saline; 10% glucose (TZ); 10% glucose plus benazepril (ACEI: 4 mg/kg daily); and 10% glucose plus valsartan (ARB: 10 mg/kg daily). The ACEI and ARB were administered into the peritoneum for 7 days. Expression of AQP-1-AQP-4 mRNA was studied by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR). Ultrafiltration volume (UFV) and peritoneal function were measured by peritoneal equilibration test (PET). In the TZ group, expression of AQP-1 and AQP-4 was enhanced in parallel with an increment in UFV. Expression of AQP-1 and AQP-4 was also observed in the mesothelium by immunofluorescence microscopy. On the other hand, in ACEI- and ARB-treated rats, expression of AQP-1 and AQP-4 was significantly suppressed, accompanied by loss of UFV. Our results suggest that the renin-angiotensin system plays an important role in the regulation of water transport in the peritoneum. Administration of ACEI or ARB in patients undergoing continuous ambulatory peritoneal dialysis should be carried out with caution.

Heme oxygenase-1 regulates vascular tone of the peritoneum undergoing peritoneal dialysis

The present study investigated the role of heme oxygenase-1 (HO-1) in regulating the vascular tone of the peritoneum undergoing peritoneal dialysis. First, we used reverse-transcriptase polymerase chain reaction (RT-PCR) to measure changes in the expression of HO-1 mRNA in the peritoneum of dehydrated Wistar Kyoto (WKY) rats. Second, we used a charge-coupled-device (CCD) camera to measure changes in the diameter and blood flow in the small artery of the peritoneum after intravenous administration of saline, hemin (4-12 mumol/kg), and tin-protoporphyrin (4-12 mumol/kg) in dehydrated WKY rats. In non dehydrated rats (control), no expression of HO-1 mRNA in the peritoneum was seen. In dehydrated and 10% glucose-treated dehydrated rats, HO-1 expression was significantly enhanced as compared with the control rats. Intravenous administration of saline induced no significant changes in the diameter of the small artery in dehydrated WKY rats. Intravenous administration of hemin induced a significant increase in the diameter of the small artery in dehydrated WKY rats. Intravenous administration of tin-protoporphyrin induced a significant reduction in the diameter of the small artery in dehydrated WKY rats. Our results suggest that 10% glucose injection into the peritoneal cavity induces overexpression of HO-1 in the peritoneum of dehydrated rats. In addition, HO-1 regulates peritoneal function by the regulation of vascular tone in the peritoneum.

Blood pressure reduction in the morning yields beneficial effects on progression of chronic renal insufficiency with regression of left ventricular hypertrophy

Self-monitoring values of blood pressure may better reflect the average long-term blood pressure value than sporadic measurements in the physician's office and be more useful for blood pressure control. In the present study, we compared the results of self-monitoring of blood pressure values, especially in the morning, with office blood pressure, and related these to progression of chronic renal insufficiency and left ventricular hypertrophy (LVH). Thirty-four patients were selected from 316 subjects with chronic renal insufficiency (average serum creatinine 1.72 +/- 0.15 mg/dl, mean age 52.6 +/- 3.5 yrs) in accordance with the following criteria (1) office blood pressure was less than 140/90 mmHg, (2) blood pressure was controlled with amlodipine (5-20 mg/day) combined with benazepril (2.5 mg/day), (3) morning blood pressure was greater than 150/90 mmHg at 6-9 AM and (4) LVH had been determined by echocardiography (posterior wall thickness; PWT > or = 12 mm). The patients were assigned to 2 groups at random and were given: (1) guanabenz (GB; 2-8 mg at I I PM, n = 17) or (2) placebo (n = 17). Two years later, the average blood pressure of both groups as measured in the office was not significantly different: however, BP in the morning was significantly reduced from 158 +/- 6 to 134 +/- 4 mmHg in GB treated group (P< 0.001). In 14 of 17 patients in GB treated group, LVH resolved and there was only mild progression of nephropathy (serum creatinine: 1.69 +/- 0.18 to 1.81 +/- 0.19 mg/dl). In 12 of 14 patients in placebo group, whose morning blood pressure remained at greater than 150/90 mmHg, LVH was retained and there was moderate progression of nephropathy (serum creatinine: 1.73 +/- 0.14 to 2.62 +/- 0.50mg/dl). From these results, it is suggested that antihypertensive treatment with combination therapy based on self-monitoring BP is cardio-renoprotective in patients with chronic renal insufficiency and LVH.

Crystal nephropathy: a variant form of myeloma kidney--a case report and review of the literature

Cast nephropathy is the most common form of myeloma kidney, and also one of the major determinants of a patient's prognosis. We experienced a case of multiple myeloma with acute renal failure that was associated with massive crystal deposition in kidney and bone marrow. Large crystal formation in myeloma kidney is a rare pathological finding in renal biopsies. In the literature, most of the cases with multiple myeloma with extracellular crystal deposition often have a rapidly progressive course with a poor prognosis. Ball et al. [1993] suggested that this type of extracellular crystal deposition be designated as "crystalglobulinemia syndrome". The characteristics of the clinical and histopathological features, rapid progression and poor outcome, and crystal formation in the tubules found in the present case and in those previously reported, support the proposal of a new concept of "crystal nephropathy".

A novel heat shock protein plays an important role in thermal stress management in cyanobacteria

A novel heat shock gene, orf7.5, which encodes a putative acidic polypeptide of 63 amino acids, was cloned from the cyanobacterium Synechococcus sp. PCC 7942. Northern blot analysis revealed the presence of 400- and 330-base orf7.5 mRNAs, which were barely detectable in the cells grown at 30 degrees C but increased transiently in response to heat shock at 40 or 45 degrees C. Primer extension analysis showed that the two mRNAs have different 5'-ends. Chloramphenicol enhanced the accumulation of the orf7.5 mRNA, whereas it inhibited the increase in the amount of the groESL mRNA. To reveal the role of the orf7.5 gene in thermal stress management, we constructed a stable mutant in which a gene conferring resistance to an antibiotic was inserted into the coding region of the orf7.5 gene. The interruption led to a marked inhibition of growth at 45 degrees C and a decrease in the basal and acquired thermo-tolerances at 50 degrees C in the transformants, indicating that the gene plays a role in thermal stress management. The orf7.5 mutant could be complemented with a return to the wild type phenotype by a DNA fragment containing orf7.5 but not by mutated orf7.5s, in which a nonsense mutation was generated by introducing a frameshift or a point mutation within the orf7.5-coding region. Thus, thermo-tolerance requires an appropriate translation product, not simply a transcript. Accumulation of the groESL transcript in the orf7.5 mutant was strongly reduced, suggesting that the orf7.5 gene product controls the expression of the groESL operon.

In vivo visualization of angiotensin II- and tubuloglomerular feedback-mediated renal vasoconstriction

BACKGROUND

A noninvasive technique to monitor renal microcirculation would be a useful tool for investigation of renal disease and the effects of drugs on the renal system. We have developed a novel, less invasive technique to visualize renal microcirculation in vivo using an intravital tapered-tip (1 mm phi) lens-probe (pencil lens-probe) videomicroscopy, which only requires insertion of the probe into superficial renal cortex in situ.

METHODS

To assess validity of this technique, the effects of angiotensin II (Ang II) and intrarenal sodium chloride loading (activator of tubuloglomerular mechanism) were examined. The renal microvasculature was successfully visualized and monitored.

RESULTS

Administration of Ang II (1, 3, 10 and 30 ng/kg/min) produced a dose-dependent constriction of afferent and efferent arterioles in similar degrees; at 30 ng/kg/min, Ang II elicited 52 +/- 3 (N = 9) and 53 +/- 3% decreases in diameter (N = 9), respectively. The Ang II-induced arteriolar constriction was completely prevented by losartan, an Ang II type 1 (AT1) antagonist. The intrarenal hypertonic saline administration elicited transient increments (from 98 +/- 8 to 122 +/- 7 mL/min, N = 6, P < 0.05), followed by a marked reduction in renal blood flow (RBF; 78 +/- 7 mL/min, P < 0.05). This response was accompanied by prominent constriction of afferent (from 15.0 +/- 1.1 to 8.5 +/- 1.1 microm, N = 6, P < 0.05), but not efferent (from 14.3 +/- 1.2 to 13.8 +/- 1.0 microm, N = 3) arterioles. Furthermore, this response was completely inhibited by furosemide, a tubuloglomerular feedback inhibitor.

CONCLUSION

: The intravital pencil lens-probe videomicroscopy can be a powerful tool for in vivo observation of renal microcirculation, with intact renal microvascular responses to two important renal homeostatic mechanisms, angiotensin II and tubuloglomerular feedback.

Successful use of thoracoscopic pericardiectomy in elderly patients with massive pericardial effusion caused by uremic pericarditis

We report the use of thoracoscopic pericardiectomy to treat two elderly patients with massive pericardial effusion caused by uremic pericarditis. A 79-year-old man, admitted to our hospital complaining of dyspnea, was diagnosed with end-stage renal failure and began maintenance hemodialysis. Although intensive hemodialysis was performed, the patient could not remain on hemodialysis because of severe hypotension during the procedure. Echocardiography revealed massive pericardial effusion and severe hypokinesis of the left ventricular wall. Pericardiocentesis was performed first, without success, followed by thoracoscopic pericardiectomy under general anesthesia. One month after the pericardiectomy, episodes of hypotension during hemodialysis improved, and dyspnea diminished. Echocardiography showed no pericardial effusion and improvement of left ventricular wall motion. Pericarditis is a fatal complication in patients with end-stage renal failure and patients on maintenance hemodialysis. The second patient received the same procedure with a similar improvement of clinical symptoms. These cases suggest that thoracoscopic pericardiectomy is a safe and effective treatment of pericardial effusion caused by uremic pericarditis in elderly patients on hemodialysis.