Correlations of IL-6 and TGF-β Gene Polymorphisms and Expressions With Osteoporotic, Thoracolumbar, Vertebral Compression Fracture

Context

Associations between genes and diseases manifest as the influence of gene expression on disease development as well as the impact of variations in the disease-related genes themselves. It's important to determine the genetic variations that can lead to compressed fractures of osteoporotic, thoracic lumbar vertebrae to develop personalized clinical methods to prevent or delay the disease's development.

Objective

The study intended to explore the correlations between the gene polymorphisms and gene expressions of the interleukin-6 (IL-6) gene and the transforming growth factor-beta (TGF-β) gene and osteoporotic, thoracolumbar, vertebral compression fracture.

Design

The research team performed an observational study using data from medical records.

Setting

The study took place at Xuzhou Medical University in Xuzhou, China.

Participants

Participants were 200 patients with an osteoporotic, thoracolumbar, vertebral compression fracture who had been admitted to the hospital at the university between 2019 and 2021 prior to the study and 200 healthy people The research team divided the participants into two groups. The patients became participants in the disease group, and the healthy individuals became participants in the control group.

Outcome Measures

The research team: (1) collected peripheral blood from the two groups, (2) extracted genomic deoxyribonucleic acids (DNAs) from karyocytes, (3) examined the IL-6 and TGF-β gene polymorphisms, and (4) analyzed and correlated participants' clinical data with the gene polymorphisms and expressions. The team used a quantitative polymerase chain reaction (qPCR) to examine the expression levels of IL-6 and TGF-β.

Results

Compared to the control group, the disease group: (1) had allele distributions that were significantly different at the rs2069829 locus of the IL-6 gene (P < .001) and at the rs3087453 of the TGF-β gene (P = .004); (2) had significantly higher frequencies of allele T at the rs2069829 locus of the IL-6 gene and of allele G at the rs3087453 locus of the TGF-β gene; (3) had genotype distributions that were significantly different at the rs2069829 locus (P < .001) and the rs2069857 locus (P = .048) of the IL-6 gene and at the rs3087453 locus (P < .001) of the TGF-β gene; (4) had frequencies that were significantly higher of the TT genotype at the rs2069829 locus, the CC genotype at the rs2069857 locus, and the GC genotype at the rs3087453 locus of the IL-6 gene and the TGF-β gene; (5) had dominant models that were significantly different at the rs2069829 locus of the IL-6 gene (P = .009) and at rs3087453 locus of the TGF-β gene (P = .026) and had a recessive model that was significantly different at the rs2069857 locus of the IL-6 gene (P = .040); (6) had significantly different haplotypes CC (P < .001) and TC (P < .001) at the rs2069829 locus and the rs2069857 locus of the IL-6 gene and a significantly different haplotype AC (P = .011) at the rs1800469 locus and the rs3087453 locus of the TGF-β gene; (7) had an IL-6 gene polymorphism at the rs2069857 locus that was related to the expression of the IL-6 gene (P < .05) and an expression of the IL-6 gene for participants with the AA genotype that was significantly lower than for other genotypes; (8) had a TGF-β gene polymorphism at the rs1800469 locus that was associated with the expression of the TGF-β gene (P < .05), and an expression for participants with the GG genotype that was significantly higher than for other genotypes; (9) had an IL-6 gene polymorphism at the rs2069857 locus with an overt correlation with the genotype of osteoporotic, thoracolumbar, vertebral compression fracture (P < .001). Also, participants in the disease group with the genotype CC mainly had type 2 and 3 fractures, while those with genotype AA primarily had type 0 and 1 fractures.

Conclusions

IL-6 and TGF-β gene polymorphisms and expressions are significantly related to osteoporotic, thoracolumbar, vertebral compression fracture.

Bioinformatics Analysis and Experimental Verification Identify Downregulation of COL27A1 in Poor Segmental Congenital Scoliosis

BACKGROUND

Congenital scoliosis (CS) represents the congenital defect disease, and poor segmental congenital scoliosis (PSCS) represents one of its types. Delayed intervention can result in disability and paralysis. In this study, we would identify the core biomarkers for PSCS progression through bioinformatics analysis combined with experimental verification.

METHODS

This work obtained the GSE11854 expression dataset associated with somite formation in the GEO database, which covers data of 13 samples. Thereafter, we utilized the edgeR of the R package to obtain DEGs in this dataset. Then, GO annotation, KEGG analyses, and DO annotation of DEGs were performed by "clusterProfiler" of the R package. This study performed LASSO regression for screening the optimal predicting factors for somite formation. Through RNA sequencing based on peripheral blood samples from healthy donors and PSCS cases, we obtained the RNA expression patterns and screen out DEGs using the R package DESeq2. The present work analyzed COL27A1 expression in PSCS patients by the RT-PCR assay.

RESULTS

A total of 443 genes from the GSE11854 dataset were identified as DEGs, which were involved in BP associated with DNA replication, CC associated with chromosomal region, and MF associated with ATPase activity. These DEGs were primarily enriched in the TGF-β signaling pathway and spinal deformity. Further, LASSO regression suggested that 9 DEGs acted as the signature markers for somite formation. We discovered altogether 162 DEGs in PSCS patients, which were involved in BP associated with cardiac myofibril assembly and MF associated with structural constituent of muscle. However, these 162 DEGs were not significantly correlated with any pathways. Finally, COL27A1 was identified as the only intersected gene between the best predictors for somite formation and PSCS-related DEGs, which was significantly downregulated in PSCS patients.

CONCLUSION

This work sheds novel lights on DEGs related to the PSCS pathogenic mechanism, and COL27A1 is the possible therapeutic target for PSCS. Findings in this work may contribute to developing therapeutic strategies for PSCS.

Vertebral compression fractures: Still an unpredictable aspect of osteoporosis

Vertebral compression fracture is a hallmark of osteoporosis (OP) and by far the most prevalent fragility fracture. It is well proven that patients who develop a vertebral compression fracture are at substantial risk for additional fractures. Diagnosis is based on adequate clinical evaluation, imaging, and laboratory tests. The imaging of OP and fragility fractures includes conventional radiology to evaluate spinal fractures, bone mineral density (BMD) testing by dual energy x-ray densitometry, quantitative computerized tomography, magnetic resonance imaging, bone scintigraphy (if necessary), and ultrasound. Screening and treatment of individuals with high risk of osteoporotic fracture are cost-effective, but approximately two-thirds of the vertebral compression fractures (VCF) that occur each year are not accurately diagnosed and, therefore, not treated. Evaluation of VCFs, even though they may be asymptomatic, seems essential to health-related and/or clinical research on OP.

Indeterminate Dendritic Cell Tumor in Thoracic Spine: A Case Report

BACKGROUND

Indeterminate dendritic cell tumor (IDCT) is an extremely rare hematologic disorder with poorly understood pathogenesis. Occasionally encountered by hematologists, unusual presentations of IDCT have not been reported in the spine literature.

METHODS

We report a 51-year-old man who presented with a 3-month history of progressively worsening axial thoracic back pain radiating to his sides. Magnetic resonance imaging revealed a 3-cm enhancing mass at the T9 vertebral body with an exophytic component causing significant canal stenosis. Initial percutaneous biopsy revealed histiocytic sarcoma.

RESULTS

The patient underwent exploratory thoracotomy and en bloc resection of the lesion with T8-10 fusion. Final pathology results revealed IDCT with fibrosis. IDCT immunostaining was partially positive for Langerhans cell marker (positive for S100 and CD1a, but lacked Birbeck granules and Langerin stain) and partially positive for blastic plasmacytoid dendritic cell neoplasm. Additionally, it was positive for CD45, CD68, and CD163. Lymphadenopathy was absent in this patient.

CONCLUSIONS

Although first reported in the 1980s, IDCT has been omitted from most classifications owing to its rarity. Hematologists have debated the cell of origin; it is believed to comprise pre-Langerhans cells, as Birbeck granules are acquired after migration to the epidermis. IDCT remains of indeterminate origin. We report the first case of spinal IDCT. Familiarity with the histologic features is warranted to ensure accurate diagnosis and appropriate treatment.

Relationship between spinal osteoarthritis and vertebral fractures in men older than 50 years: data from the Camargo Cohort Study

Spinal osteoarthritis has been suggested as a risk factor for vertebral fractures. However, results are conflicting: most of the data are focused on the lumbar region, and referred to postmenopausal women, whereas data for men are scarce. The aim of this study is to assess the relationship between spinal osteoarthritis and vertebral fractures in men over 50 years of age. We conducted a cross-sectional study, nested in a prospective population-based cohort, including 507 community-dwelling men, 93 of them with at least one vertebral fracture. Vertebral fractures, osteophytosis, and disc space narrowing (DSN) were assessed by lateral thoracic and lumbar radiographs. Anthropometric, clinical, and densitometric variables were also analyzed. A multiple logistic regression model was performed. Eighty-five percent of vertebral fractures were located at the thoracic spine. Osteophytosis and DSN showed a bimodal distribution, with major frequency peaks at mid- and distal lumbar spine. The three distributions overlapped around the T9 vertebra. We did not find any relationship between lumbar osteoarthritis and vertebral fractures. Nevertheless, thoracic osteophytosis (OR, 1.84; 95 % CI, 1.05-3.17; p = 0.03) and DSN (OR, 2.52; 95 % CI, 1.43-4.46; p = 0.001) were found to be independently associated with prevalent vertebral fractures, after adjusting for confounders. Our results suggest a positive relationship between radiologic osteoarthritic changes at the thoracic spine and prevalent vertebral fractures in men more than 50 years of age. Osteoarthritis may act as a local risk factor, in addition to other mechanical factors, resulting in a greater propensity to fracture, especially at the mid-thoracic region.

Effects of human parathyroid hormone on bone morphogenetic protein signal pathway following spinal fusion in diabetic rats

Osteoporosis is a major complication in patients with diabetes mellitus. Thus, it is crucial to study the signal mechanisms responsible for enhancement of bone mass in diabetes. Administration of human parathyroid hormone (hPTH) has been reported to prevent osteoblast apoptosis and have anabolic effects on bone in animals and humans. In the present study, we examined the effects of hPTH on expression of bone morphogenetic protein type 2 (BMP-2) and its receptor BMPR2 in diabetic rats following spinal fusion. Our data show that hPTH amplified BMP-2 and BMPR2 in bone tissues of non-diabetic rats, but not in diabetic rats. Our data further demonstrate that hPTH plays a role in regulating BMP-2 and BMPR2 via mTOR-PI3K signal pathway. We suggest specific signaling pathways by which hPTH regulates BMP-2 via mTOR-PI3K mechanism in bone formation following spinal fusion. Notably, our data indicate under diabetic conditions this signal pathway is impaired, thereby likely affecting bone formation after spinal fusion. The subsequent induction of BMP-2 and BMPR2 are likely a part of the protective effects aimed at attenuating pathological bone damage as a result of diabetes.

Relationship Between BMD and Prevalent Vertebral Fractures in Indian Women Older Than 50 Yr

The purpose of the study was to study the relationship of morphometric vertebral fractures with bone mineral density (BMD) in Indian women older than 50 yr. Four hundred fifteen healthy Indian women older than 50 yr (mean age: 62.8 yr) underwent lateral X-rays of the lumbar and thoracic spine. Genant's semiquantitative method was used to diagnose and classify morphometric vertebral fractures. BMD was measured by DXA at lumbar spine and total hip. Recruited subjects underwent anthropometric, biochemical, and hormonal evaluation. Vertebral fractures were present in 17.1% (95% confidence interval: 13.5, 20.8) subjects. Prevalence of osteoporosis based on BMD was 35.7%. By adding those with prevalent fractures, the number of women requiring therapy for osteoporosis would increase to 46.5%. The BMD measured at femur neck, total hip, and lumbar spine (L1eL4) was not found to be lower in women with vertebral fractures as compared with those without fractures. BMD was not found to be lower in women with vertebral fractures as compared with those without fractures. Significant number of additional subjects with BMD in the normal or osteopenic range become eligible for osteoporosis treatment when presence of vertebral fracture is used as an independent indication for such treatment.

Diagnostic Ability of FDG-PET/CT in the Detection of Malignant Pleural Effusion

We investigated the role of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) for the differential diagnosis of malignant and benign pleural effusion. We studied 36 consecutive patients with histologically proven cancer (excluding malignant mesothelioma) who underwent FDG-PET/CT for suspected malignant pleural effusion. Fourteen patients had cytologically proven malignant pleural effusion and the other 22 patients had either negative cytology or clinical follow-up, which confirmed the benign etiology. We examined the maximum standardized uptake values (SUV max) of pleural effusion and the target-to-normal tissue ratio (TNR), calculated as the ratio of the pleural effusion SUV max to the SUV mean of the normal tissues (liver, spleen, 12th thoracic vertebrae [Th12], thoracic aorta, and spinalis muscle). We also examined the size and density (in Hounsfield units) of the pleural effusion and pleural abnormalities on CT images. TNR (Th12) and increased pleural FDG uptake compared to background blood pool were significantly more frequent in cases with malignant pleural effusion (P < 0.05 for both). The cutoff TNR (Th12) value of >0.95 was the most accurate; the sensitivity, specificity, and accuracy for this value were 93%, 68%, and 75%, respectively. FDG-PET/CT can be a useful method for the differential diagnosis of malignant and benign pleural effusion.

Accelerating the tempo of the segmentation clock by reducing the number of introns in the Hes7 gene

Periodic somite segmentation is controlled by the cyclic gene Hes7, whose oscillatory expression depends upon negative feedback with a delayed timing. The mechanism that regulates the pace of segmentation remains to be determined, but mathematical modeling has predicted that negative feedback with shorter delays would give rise to dampened but more rapid oscillations. Here, we show that reducing the number of introns within the Hes7 gene shortens the delay and results in a more rapid tempo of both Hes7 oscillation and somite segmentation, increasing the number of somites and vertebrae in the cervical and upper thoracic region. These results suggest that the number of introns is important for the appropriate tempo of oscillatory expression and that Hes7 is a key regulator of the pace of the segmentation clock.

Relationship between increased endogenous parathormone levels and bone density in postmenopausal women treated with bisphosphonates

AIM

Bisphosphonates increase bone mineral density (BMD) and also increase parathyroid hormone (PTH): the rule of increased PTH on BMD is not well known. The aim of our study was to assess the relationship between endogenous PTH levels and BMD after 18 months of antiresorptive therapy in a group of post-menopausal women with normal baseline PTH levels.

METHODS

A retrospective study was conducted on 62 women with normal baseline PTH levels (mean age 62.7 ± 8.6 years) who underwent dual-energy X-ray absorptiometry, thoracic-lumbar radiography, and blood and urine sampling at the baseline and after 18 months. All patients were treated with bisphosphonates and received calcium and vitamin D3 supplementation.

RESULTS

In the whole group, after 18 months, mean BMD improved both at lumbar spine (0.53 ± 0.09 vs. 0.49 ± 0.09 g/cm2; P<0.05) and at femur (0.66 ± 0.08 vs. 0.65 ± 0.09 g/cm2; P<0.05); PTH levels (56.80 ± 19.07 vs. 48.74 ± 14.99 pg/mL; P<0.001) and serum 25-hydroxyvitamin D (60.73 ± 29.87 vs. 49.81 ± 26.56 ng/mL; P<0.05) increased. Dividing the patients according PTH variation (>0 or ≤ 0), the group with ΔPTH>0 had higher percentage increase of BMD at spine (8.0 ± 9% vs. 4 ± 7.5%; P<0.001) and at total hip (3 ± 9% vs. 0.49 ± 8.9%; P<0.001) while the bone alkaline phosphatase significantly decreased (-11.80 ± 2.19 vs. -4.05 ± 3.08 ug/L; P<0.001) than the other group.

CONCLUSION

Increased endogenous PTH levels seems to be associated with a higher BMD increase in patients treated with bisphosphonates for postmenopausal osteoporosis. The increase of PTH must be clarified by further investigations.

Impairment of retrograde neuronal transport in oxaliplatin-induced neuropathy demonstrated by molecular imaging

BACKGROUND AND PURPOSE

The purpose of our study was to utilize a molecular imaging technology based on the retrograde axonal transport mechanism (neurography), to determine if oxaliplatin-induced neurotoxicity affects retrograde axonal transport in an animal model.

MATERIALS AND METHODS

Mice (n = 8/group) were injected with a cumulative dose of 30 mg/kg oxaliplatin (sufficient to induce neurotoxicity) or dextrose control injections. Intramuscular injections of Tetanus Toxin C-fragment (TTc) labeled with Alexa 790 fluorescent dye were done (15 ug/20 uL) in the left calf muscles, and in vivo fluorescent imaging performed (0-60 min) at baseline, and then weekly for 5 weeks, followed by 2-weekly imaging out to 9 weeks. Tissues were harvested for immunohistochemical analysis.

RESULTS

With sham treatment, TTc transport causes fluorescent signal intensity over the thoracic spine to increase from 0 to 60 minutes after injection. On average, fluorescence signal increased 722%+/-117% (Mean+/-SD) from 0 to 60 minutes. Oxaliplatin treated animals had comparable transport at baseline (787%+/-140%), but transport rapidly decreased through the course of the study, falling to 363%+/-88%, 269%+/-96%, 191%+/-58%, 121%+/-39%, 75%+/-21% with each successive week and stabilizing around 57% (+/-15%) at 7 weeks. Statistically significant divergence occurred at approximately 3 weeks (p≤0.05, linear mixed-effects regression model). Quantitative immuno-fluorescence histology with a constant cutoff threshold showed reduced TTc in the spinal cord at 7 weeks for treated animals versus controls (5.2 Arbitrary Units +/-0.52 vs 7.1 AU +/-1.38, p<0.0004, T-test). There was no significant difference in neural cell mass between the two groups as shown with NeuN staining (10.2+/-1.21 vs 10.5 AU +/-1.53, p>0.56, T-test).

CONCLUSION

We show-for the first time to our knowledge-that neurographic in vivo molecular imaging can demonstrate imaging changes in a model of oxaliplatin-induced neuropathy. Impaired retrograde neural transport is suggested to be an important part of the pathophysiology of oxaliplatin-induced neuropathy.

Tophaceous pseudogout of the thoracic spine

Calcium pyrophosphate dihydrate deposition disease (CPDD, tophaceous pseudogout) is a rare crystal arthropathy characterized by pyrophosphate crystal deposition in joints, synovitis and chondrocalcinosis on imaging. We present the case of a 72-year-old man with 6 months of left chest pain; magnetic resonance imaging revealed a T9/T10 herniated disc. Intraoperatively, the material was sent for pathological analysis revealing pseudogout. Axial calcium pyrophosphate crystal deposition is rare but reported in the literature and found at the craniocervical junction and skull. Spinal calcium pyrophosphate crystal deposition is rare in the thoracic spine. It is often asymptompatic and can involve the disc or ligaments. This case demonstrates a unique presentation of CPDD.

Analysis of bone mineral density distribution at trabecular bones in thoracic and lumbar vertebrae using X-ray CT images

The number of participants in thoracic or abdominal examinations using multi-detector-row CT (MDCT) has been increasing recently. If the degree of progress of osteoporosis can be estimated using these images, it may be useful as it will allow predictions of vertebral fractures without an additional radiation exposure. The aims of this study were to investigate segmental variations in bone mineral density (BMD) distributions of thoracic and lumbar vertebral bodies and to show specific differences according to age and gender. A large database including 1,031 Japanese subjects for whom MDCT was used to examine various organs and tissues was utilized in this study for trabecular BMD at thoracic and lumbar vertebrae. In relationship to vertebral level, L3 had the lowest trabecular BMD. BMD tended to gradually increase from L3 to T1 in all age categories. Also, there was a moderate correlation between vertebrae whose distance from each other was great whereas there was a high correlation between adjacent vertebrae. It may be appropriate to use an arbitrary vertebra as a first approximation for assessing vertebrae that are in the area of predilection for the fracture; however, to better understand their behavior, it may be necessary to measure BMD directly in this region. This study showed trabecular BMD distribution at healthy thoracic and lumbar vertebrae in Japanese subjects and specific differences in age and gender. Improved knowledge about vertebral BMD may help with the diagnosis of primary osteoporosis using MDCT.

Quantitative plutonium microdistribution in bone tissue of vertebra from a Mayak worker

The purpose of this study was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, the quantitative relationships of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in humans as well as other cases with different exposure patterns and types of plutonium.

A soluble activin receptor Type IIA fusion protein (ACE-011) increases bone mass via a dual anabolic-antiresorptive effect in Cynomolgus monkeys

Activin A belongs to the TGF-beta superfamily and plays an important role in bone metabolism. It was reported that a soluble form of extracellular domain of the activin receptor type IIA (ActRIIA) fused to the Fc domain of murine IgG, an activin antagonist, has an anabolic effect on bone in intact and ovariectomized mice. The present study was designed to examine the skeletal effect of human ActRIIA-IgG1-Fc (ACE-011) in non-human primates. Young adult female Cynomolgus monkeys were given a biweekly subcutaneous injection of either 10mg/kg ACE-011 or vehicle (VEH) for 3months. Treatment effects were evaluated by histomorphometric analysis of the distal femur, femoral midshaft, femoral neck and 12th thoracic vertebrae, by muCT analysis of femoral neck and by biomarkers of bone turnover. Compared to VEH, at the distal femur ACE-011-treated monkeys had significantly increased cancellous bone volume (+93%), bone formation rate per bone surface (+166%) and osteoblast surface (+196%) indicating an anabolic action. Monkeys treated with ACE-011 also had decreased osteoclast surface and number. No differences were observed in parameters of cortical bone at the midshaft of the femur. Similar to distal femur, ACE-011-treated monkeys had significantly greater cancellous bone volume, bone formation rate and osteoblast surface at the femoral neck relative to VEH. A significant increase in bone formation rate and osteoblast surface with a decrease in osteoclast surface was observed in thoracic vertebrae. muCT analysis of femoral neck indicated more plate-like structure in ACE-011-treated monkeys. Monkeys treated with ACE-011 had no effect on serum bone-specific alkaline phosphatase and CTX at the end of the study. These observations demonstrate that ACE-011 is a dual anabolic-antiresorptive compound, improving cancellous bone volume by promoting bone formation and inhibiting bone resorption in non-human primates. Thus, soluble ActRIIA fusion protein may be useful in the prevention and/or treatment of osteoporosis and other diseases involving accelerated bone loss.

[Quantitative plutonium microdistribution in bone tissue of vertebra from occupationally exposed worker]

The purpose of this work is the receiving of quantitative data on Pu microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. Thoracic vertebra sample was taken for the study from former Mayak worker with rather high Pu burden, including information on occupational and exposure history, medical information and data on Pu content in organs. Lexan film autodiagrams were obtained using method of neutron-induced autoradiography from bone tissue sections. Quantitative analysis of randomly selected vision fields on one of autoradiograms was performed: fission fragment tracks Pu in different bone tissue areas were calculated, surface of bone tissue areas were defined. Quantitative information on Pu microdistribution in human bone tissue was obtained for the first time. On the basis of obtained data quantitative relation of Pu decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. Actual quantitative relation of decays in bone volume to decays on bone surface is significantly different from recommended by ICRP for cortical fraction. Biokinetic model parameters of extrapulmonary ICRP compartment might need to be adjusted after expansion of data set on quantitative Pu microdistribution in other bone types in human that will involve new cases with different exposure pattern of radionuclide.

A double-blind placebo-controlled study of intravenous clodronate for prevention of steroid-induced bone loss in inflammatory bowel disease

BACKGROUND & AIMS

Osteoporosis is common in patients with inflammatory bowel disease (IBD). Corticosteroids induce a rapid and important bone loss. Clinical trials have shown oral bisphosphonates to effectively prevent steroid-induced bone loss. However, patients with IBD have been excluded from most of these studies because of potential digestive adverse events. Clodronate is a non-amino-bisphosphonate available in intravenous form without expected digestive (as oral bisphosphonates) or proinflammatory (as amine bisphosphonates) side effects. Our aim was to assess the efficacy of intravenous clodronate in preventing steroid-induced bone loss.

METHODS

A 12-month, double-blind, randomized, placebo-controlled trial was conducted in IBD patients beginning a steroid therapy. Sixty-seven patients (median disease duration, 38 mo; range, 1-240 mo) were randomized to receive one infusion per 3 months of either intravenous clodronate (900 mg, n = 33) or placebo. All the patients received calcium (1 g/day) and vitamin D (800 IU/day). The main outcome was the change in lumbar bone mineral density (BMD) between baseline and 1 year. Secondary outcomes included change in femoral neck BMD and adverse events.

RESULTS

After 1 year, there was no change in BMD in the clodronate group, neither at the spine (-0.2%, not significant) nor at the femoral neck (2.3%, NS). In contrast, there was a significant decrease in lumbar spine (-2.0%, P = .0018) and femoral neck (-1.7%, P = .045) BMD in the placebo group. Tolerance to treatment was good.

CONCLUSIONS

Intravenous clodronate is effective in the prevention of bone loss induced by steroids in patients with IBD.

Combined increased and decreased skeletal uptake of F-18 FDG

Increased uptake of F-18 FDG is the general mainstay of diagnosis, because it indicates hypermetabolic foci of pathology. This case, describing a patient with relapsing lymphoma, represents the diagnostic dilemmas of both locally decreased and diffusely increased uptake in the skeleton.

Vertebral morphometry by DXA: a comparison of supine lateral and decubitus lateral densitometers

Identification of vertebral fracture has become increasingly important in the diagnosis and management of osteoporosis. This study compares the morphometric techniques on a fan beam dual-energy X-ray absorptiometry (DXA) GE-Lunar Expert system (Expert) using a supine lateral position and a narrow fan beam GE-Lunar Prodigy system (Prodigy; GE Lunar, Madison, WI) that requires lateral decubitus positioning. Patient acceptability, image quality, observer, and equipment variability were determined. Study subjects were recruited from clinical referrals sent for a routine DXA study that included vertebral morphometry. Twenty-five patients underwent lateral vertebral assessment on both machines and completed a questionnaire on comfort and tolerability. Analysis was undertaken by two trained observers. Vertebral height, anterior/posterior height (A/P) and mid/posterior height (M/P) ratios, image quality, and prevalent fractures were assessed. There were no significant differences in patient comfort or image quality scores. More upper thoracic vertebrae could be assessed on the Expert, and good radiographic positioning was easier to achieve on the Expert. Inter-observer coefficients of variance percentage (CV%) of vertebral height was lower on the Prodigy (3.5% in the lumbar spine rising to 12.8% in the thoracic spine) than the Expert (4.2% to 16.9%). Inter-observer CV% for A/P and M/P ratios varied from 2.5% to 10.5% on the Prodigy compared with 3.5% to 12.3% on the Expert, depending on vertebral level. The variation between instruments was similar to the inter-observer CV% (anterior height: -0.11+/-1.65 mm; mid height: 0.54+/-1.51 mm; posterior height: 0.43+/-1.46 mm). There was good agreement between observers and between the Expert and Prodigy in identifying severe fractures, but lack of agreement in identifying moderate fractures. In conclusion, there was no clinically significant difference in patient comfort and image quality between the Expert and the Prodigy. The inter-observer variations in vertebral height and A/P and M/P ratios are similar to the variations between instruments. In making the change from the supine lateral to the decubitus lateral positioning, measurements of vertebral height are reproducible and patient comfort is not compromised.

Activated microglia contribute to the maintenance of chronic pain after spinal cord injury

Traumatic spinal cord injury (SCI) results not only in motor impairment but also in chronic central pain, which can be refractory to conventional treatment approaches. It has been shown recently that in models of peripheral nerve injury, spinal cord microglia can become activated and contribute to development of pain. Considering their role in pain after peripheral injury, and because microglia are known to become activated after SCI, we tested the hypothesis that activated microglia contribute to chronic pain after SCI. In this study, adult male Sprague Dawley rats underwent T9 spinal cord contusion injury. Four weeks after injury, when lumbar dorsal horn multireceptive neurons became hyperresponsive and when behavioral nociceptive thresholds were decreased to both mechanical and thermal stimuli, intrathecal infusions of the microglial inhibitor minocycline were initiated. Electrophysiological experiments showed that minocycline rapidly attenuated hyperresponsiveness of lumbar dorsal horn neurons. Behavioral data showed that minocycline restored nociceptive thresholds, at which time spinal microglial cells assumed a quiescent morphological phenotype. Levels of phosphorylated-p38 were decreased in SCI animals receiving minocycline. Cessation of delivery of minocycline resulted in an immediate return of pain-related phenomena. These results suggest an important role for activated microglia in the maintenance of chronic central below-level pain after SCI and support the newly emerging role of non-neuronal immune cells as a contributing factor in post-SCI pain.

Anesthetic Requirements and Stress Hormone Responses in Spinal Cord-Injured Patients Undergoing Surgery Below the Level of Injury

Neuraxial anesthesia decreases the minimum alveolar concentration. We determined the effects of spinal cord injury (SCI) on sevoflurane requirements and stress hormone response. Twenty-two chronic SCI patients undergoing surgery below the level of the injury were enrolled in the study, and 15 patients without cord injury served as control patients. Bispectral index score was maintained at 40-50. Measurements included end-tidal sevoflurane concentrations, systolic arterial blood pressure, heart rate, and plasma catecholamine and cortisol concentrations. During surgery, systolic arterial blood pressure, heart rate, and Bispectral index were comparable between SCI and control groups. However, end-tidal sevoflurane concentration was significantly smaller in the SCI (0.81%-1.06%) versus control (1.28%-1.31%) patients. In the control group, plasma norepinephrine and cortisol concentrations were significantly increased during and 1 h after surgery compared with awake baseline values. In the SCI group, the sympathoadrenal and cortisol responses were virtually abolished. We conclude that SCI reduces the anesthetic requirement by 20%-39% during surgery below the level of injury, in association with blunted sympathoadrenal and cortisol responses.

Preservation of thoracic spine microarchitecture by alendronate: comparison of histology and microCT

The effect of bisphosphonates on trabecular microarchitecture may contribute to the reduced risk of vertebral fracture with treatment independent of the bone volume. Trabecular structure was examined at the twelfth thoracic vertebra after 2 years of treatment of two groups of ovariectomized baboons on high and low doses of alendronate, compared with ovariectomized and non-ovariectomized controls. Standard 2D histological measurements showed that alendronate treatment of ovariectomized animals resulted in significantly higher total trabecular length and a lower marrow star volume in comparison with ovariectomized controls indicating preservation of connectivity. Similarly when the vertebrae were examined using a novel thick slice technique that combines 2D and 3D information, ovariectomy produced a significantly higher number of "real" trabecular termini in comparison with normal. When ovariectomized animals were treated with increasing doses of alendronate, fewer "real" termini were seen. MicroCT analysis (2D and 3D) correlated well with the histological measurements, although more variability and less discrimination between groups was seen, with no statistically significant differences with alendronate treatment. Reduced vertebral fracture risk with alendronate may be due to a combination of factors including the increased bone volume, reduced turnover and greater mineralization reported by others. Added to this is now suggested the preservation of several aspects of vertebral cancellous architecture, with microscopy the most sensitive method of analysis.

Bone mineral density of human female cervical and lumbar spines from quantitative computed tomography

STUDY DESIGN

This study determined bone mineral density (BMD) of cervical, thoracic, and lumbar vertebrae in healthy asymptomatic human subjects.

OBJECTIVES

To test the hypothesis that BMD of neck vertebrae (C2-C7) is equivalent to BMD of lumbar vertebrae (L2-L4).

SUMMARY OF BACKGROUND DATA

BMD of lumbar vertebrae is correlated to their strength. Although numerous studies exist quantifying BMD of the human lumbar spine, such information for the cervical spine is extremely limited. In addition, BMD correlations are not established between the two regions of the spinal column.

METHODS

Adult healthy human female volunteers with ages ranging from 18 to 40 years underwent quantitative computed tomography (CT) scanning of the neck and back. All BMD data were statistically analyzed using paired nonrepeating measures ANOVA techniques. Significance was assigned at a P < 0.05. Linear regression analyses were used to compare BMD as a function of level and region; +/-95% confidence intervals were determined.

RESULTS

When data were grouped by cervical (C2-C7), thoracic (T1), and lumbar (L2-L4) spines, mean BMD was 260.8 +/- 42.5, 206.9 +/- 33.5, and 179.7 +/- 23.4 mg/mL. Average BMD of cervical vertebrae was higher than (P < 0.0001) thoracic and lumbar spines. Correlations between BMD and level indicated the lowest r value for T1 (0.42); in general, the association was the strongest in the lumbar spine (r = 0.89-0.95). The cervical spine also responded with good correlations among cervical vertebrae (r ranging from 0.66 to 0.87).

CONCLUSIONS

The present study failed to support the hypothesis that BMD of lumbar spine vertebrae is equivalent to its cranial counterparts. The lack of differences in BMD among the three lumbar vertebral bodies confirms the appropriateness of using L2, L3, or L4 in clinical or biomechanical situations. However, significant differences were found among different regions of the vertebral column, with the cervical spine demonstrating higher trabecular densities than the thoracic and lumbar spines. In addition, the present study found statistically significant variations in densities even among neck vertebrae.

An immunohistochemical evaluation of extracellular matrix components in the spinal posterior longitudinal ligament and intervertebral disc of the tiptoe walking mouse

Ossification of the posterior longitudinal ligament (OPLL) in the spine is caused by systemic and/or regional factors affecting the regulation of osteocartilaginous formation and maintenance. The aims of this study were to elucidate the relationship between the degeneration of the intervertebral discs and changes in the posterior longitudinal ligament (PLL) in the tiptoe walking (ttw) mouse, an animal model of OPLL, and to analyze the sequential changes of the cells producing extracellular matrix components using immunohistochemical methods. At 6 weeks of age, the discs degenerated and the chondrocytes in the nucleus pulposus were positive for chondroitin-6-sulfate in the ttw mice. The fibroblasts in the PLL at the disc level were positively stained with type II and XI collagens. At 14 weeks, the discs herniated into the thickened PLL, and chondrocyte-like cells appeared in the PLL at vertebral endplate level. At 18 and 22 weeks, the number of chondrocyte-like cells increased in the PLL and expressed type I collagen. A potent regional factor causing OPLL in the ttw mice appears to be the initial degeneration and subsequent herniation of the nucleus pulposus. These sequential changes in the ttw mice were accelerated by administration of etidronate. It was suggested that etidronate stimulated the cartilaginous hyperplasia in the PLL of the ttw mice. It appeared as if the PLL transformed itself into cartilaginous tissue to repair the degeneration of the intervertebral disc.

Decreased dynorphin A (1–17) in the spinal cord of spastic rats after the compressive injury

Spasticity in rat hindlimbs was induced by compressing cervical spinal cord with a wax ball. Ashworth score and H-reflex were measured 1 week after the surgery. The results showed that: (1) muscle spasm was detected in the hindlimbs a week after the operation and maintained at least 8 weeks, (2) in the spastic animals, dynorphin A (1-17)-ir decreased significantly in thoracic and lumbar segments of the spinal cord and (3) peripheral administration of kappa receptor agonist U50488H and electrical stimulation at 100 Hz effectively relieved the muscle spasm. Our data supported the note that the reduction of endogenous dynorphin A (1-17) might play an important role in the pathogenesis of spinally induced muscle spasticity and the replenishment of its shortage might relieve the spasticity.

Prevalence of and risk factors for low bone mineral density and vertebral fractures in patients with systemic lupus erythematosus

OBJECTIVE

To examine the prevalence of and risk factors for low bone mineral density (BMD) and vertebral fractures in patients with systemic lupus erythematosus (SLE).

METHODS

We studied 107 SLE patients. Demographic and clinical data were collected, and radiographs of the thoracic and lumbar spine and BMD measurements by dual x-ray absorptiometry were performed. Vertebral deformities were scored according to the method of Genant et al: fractures were defined as a reduction of > or = 20% of the vertebral body height. Osteoporosis was defined as a T score less than -2.5 SD and osteopenia as a T score less than -1.0 SD in at least 1 region of measurement.

RESULTS

Osteopenia was present in 39% of the patients and osteoporosis in 4% (93% female; mean age 41.1 years). In multiple regression analysis, low BMD in the spine was associated with a low body mass index (BMI), postmenopausal status, and 25-hydroxyvitamin D deficiency. Low BMD in the hip was associated with low BMI and postmenopausal status. At least 1 vertebral fracture was detected in 20% of the patients. Vertebral fractures were associated with ever use of intravenous methylprednisolone and male sex.

CONCLUSION

Risk factors for low BMD in SLE patients are low BMI, postmenopausal status, and vitamin D deficiency. While osteoporosis defined as a low T score was found in only 4% of the patients, osteoporotic vertebral fractures were detected in 20%. The high prevalence of low BMD and vertebral fractures implies that more attention must be paid to the prevention and treatment of osteoporosis and fractures in SLE.

Aseptic discitis in patients with ankylosing spondylitis: a retrospective study of 14 cases

OBJECTIVES

To determine whether patients with ankylosing spondylitis (AS) and discitis exhibit specific characteristics as compared to patients who have AS without discitis.

METHODS

We retrospectively collected clinical, laboratory, and imaging data from the charts of 79 patients with AS admitted to a rheumatology department.

RESULTS

Of the 79 patients, 14 (18%) had discitis that was not due to infection or trauma. Mean age at the diagnosis of AS was 40 years and mean duration of AS at admission was 10 years, with no difference between the two groups. In three patients, discitis was the inaugural manifestation of AS. Two patients had discitis at two levels. The lumbar and thoracolumbar segments were the most common sites of discitis. Symptoms of discitis were present in 10 of the 14 patients. Stage III sacroiliitis was significantly more common in the patients with discitis. None of the patients experienced neurological compromise.

CONCLUSION

The frequency of aseptic discitis in patients with AS is probably overestimated as a result of inclusion and exclusion biases. Discitis usually occurs at an advanced stage of AS under the form of an erosive condition related to both mechanical factors and osteoporosis. Inaugural or early discitis can occur, however, as a result of the inflammatory process.

Liver and vertebral uptake of Tc-99m macroaggregated albumin (MAA)

An unusual phenomenon during lung scintigraphy is presented. Besides visualization of the lungs, accumulation of Tc-99m macroaggregated albumin (MAA) was seen in a small part of the liver and in and around several thoracic vertebrae. Contrast-enhanced radiographic computed tomography revealed extensive collateral pathways, which were caused by a partially obstructed superior vena cava. Shunting of systemic venous blood flow through chest wall veins to the portal system was responsible for accumulation of MAA in the liver. Retrograde blood flow through dilated thoracic vertebral veins resulted in visualization of the bone marrow.

The influence of posterior instrumentation on adjacent and transfixed facet joints in patients with thoracolumbar spinal injuries: a morphological in vivo study using computerized tomography osteoabsorptiometry

STUDY DESIGN

Subchondral mineralization of adjacent and transfixed facet joints was analyzed in patients with thoracolumbar spinal injuries, both before posterior instrumentation and after removal of the spinal implant.

OBJECTIVE

To examine the influence of posterior instrumentation on content and distribution of subchondral mineralization as a correlate of the long-term load acting on the adjacent and transfixed zygapophysial joints.

SUMMARY OF BACKGROUND DATA

Posterior stabilization plays an important role in the treatment of spinal injuries and is a standard technique for the treatment of thoracolumbar spinal fractures. Studies have shown that stress and motion in the adjacent segments are altered in the presence of instrumentation.

METHODS

Twenty-three patients with thoracolumbar spinal injuries had computerized tomography (CT) during the course of routine posttraumatic diagnostics and subsequently received bisegmental posterior fixation with an internal fixator. Second CT were obtained after removal of the fixation device, which was performed on an average of 9.4 months after the trauma. Patients were divided into 2 groups with follow-up CT taken within either less than 3 months (group A: average 7.3 days, 15 patients) or 6 and more months (group B: average 17 months, 8 patients) after the internal fixator had been removed. Quantitative and qualitative CT osteoabsorptiometry were used to assess changes in subchondral mineralization, reflecting the altered load acting on the adjacent and bridged zygapophysial joints.

RESULTS

There was a significant difference between preoperative and postoperative calcium values (P < 0.001) for the whole patient group. Mineralization decrease was significantly more often found than increase (P < 0.001). A separate analysis of the 2 groups of patients revealed significant differences between group A and B (P < 0.001). In group A, a mineralization decrease was found in 61.3% and an increase in 11.0% of the facet joints, while in group B, a mineralization decrease was shown in 21.9% and an increase in 41.0%. No significant differences between adjacent and transfixed facets were found except in group B, in which the suprajacent joints showed a significantly higher mineralization increase than the transfixed joints (P = 0.030).

CONCLUSIONS

Decrease in subchondral mineralization indicates reduced load acting on the examined zygapophysial joints. This finding in patients with early follow-up CT seems to be caused by reduced activity in most of the patients until removal of the spinal implant. In patients with longer intervals between removal of the fixator and second CT, higher loads acting on the adjacent and bridged joints are shown morphologically. Whether or not these changes lead to spondylarthritis has to be studied in a long-term follow-up.

The monotonic and fatigue properties of osteoporotic thoracic vertebral bodies

STUDY DESIGN

Measurement of the monotonic and fatigue properties of osteoporotic thoracic vertebral bodies.

OBJECTIVES

To determine the loading values at which osteoporotic vertebral bodies are susceptible to failure.

SUMMARY OF BACKGROUND DATA

Vertebral compression fractures are the most common osteoporotic fracture. Eighty-three percent of vertebral compression fractures are caused by moderate or less trauma, and there is not a specific traumatic event in 59% of these cases. Fatigue loading can lead to premature failure, although the relationship between loading and cycles to failure is not well established.

METHODS

Eighteen osteoporotic thoracic vertebral bodies were tested in monotonic compression to determine the correlation between the bone mineral content and the ultimate compressive load. Seventeen osteoporotic thoracic vertebral bodies were cyclically loaded at varying percentages of the ultimate compressive load until failure to determine the relationship between loading and fatigue life.

RESULTS

The bone mineral content was linearly correlated with ultimate compressive load. Based on our regression analysis, a 10% decrease in bone mineral content will lead to an approximate 10% decrease in ultimate compressive load. The percentage of ultimate compressive load was inversely correlated to the logarithm of cycles to failure, with specimens loaded at 60%, 70%, and 80% of ultimate compressive load lasting on average 5.6 x 10, 4.0 x 10, and 31 cycles to failure, respectively.

CONCLUSIONS

The bone mineral content is a strong predictor of the ultimate compressive load, while the percentage of the ultimate compressive load is a strong predictor of the cycles to failure for osteoporotic thoracic vertebral bodies.

Differences in thoracic kyphosis and in back muscle strength in women with bone loss due to osteoporosis

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To determine if thoracic kyphosis was different in older women grouped based on their bone mineral density (BMD) and back extensor strength (BES), and to determine if an association between and these variables exist.

SUMMARY OF BACKGROUND DATA

Changes in kyphosis might be related to back extensor weakness in patients with osteoporosis. Disproportionate weakness in back extensor musculature considerably increases the possibility of deformities in the fragile osteoporotic spine.

METHODS

A total of 189 female subjects 50 to 80 years of age were grouped by their BMD and additionally by their BES. All were evaluated for thoracic kyphosis, maximal isometric strength of the back extensors, and BMD of the lumbar spine and the hip.

RESULTS

There was no significant difference in thoracic kyphosis among all groups. Multivariate analyses of BES and BMD showed that only BES might influence thoracic kyphosis (P = 0.02). There was no correlation between BES and BMD. Statistically significant deficit in BES was observed only between the osteoporotic and osteopenic group (P < 0.05). The importance of BES in maintaining posture was observed when the study population was divided according to their BES level. With respect to thoracic kyphosis and BMD values, there were no statistical differences between strong women (BES more than 60 N) and those with medium BES (BES between 60 and 35 N). But the weakest group (BES less then 35 N) had significantly higher (P < 0.05) mean values of thoracic kyphosis in comparison to strong women (BES more than 60 N) and those with medium BES (BES between 60 and 35 N).

CONCLUSION

The severity of thoracic kyphosis may be influenced especially by changes in BES. Therefore, provision of strong, natural extrinsic support for the spine seems to be important to decrease the incidence of spinal deformity.

Validation of thoracic quantitative computed tomography as a method to measure bone mineral density

The purpose of this study was to measure precision of thoracic quantitative computed tomography (QCT) bone mineral density (BMD) and correlation to lumbar spine QCT bone density. We measured the reproducibility of thoracic QCT; two consecutive thoracic QCT scans of the T9, T10, and T11 vertebrae were performed on 95 subjects (49 females, 46 males; mean age, 62.5 years) undergoing coronary scanning. In order to correlate the thoracic to standard lumbar measurement, the subjects also underwent a lumbar QCT scan of the L1, L2, and L3 vertebrae as part of an abdominal aortic scanning study. The variation of thoracic BMD was assessed in different ethnic subgroups. Consecutive thoracic QCT measurements showed good agreement (r=0.98; RMS CV=5.78%). Thoracic bone density was significantly higher than lumbar bone density results (paired t-test, P=0.003), but the two methods correlated well (r=0.86). The regression equation for the relationship between lumbar (X) and thoracic (Y) QCT was Y=0.87X + 22.97. The standard error of estimate was 19.0 mg/cm3. Thoracic QCT from coronary calcium thoracic scans is able to measure BMD with rescan precision and regression errors that are small compared to the biologic variability in the population. Given the relatively small precision error and the reasonable correlation to lumbar BMD, an ancillary assessment of thoracic BMD in a cardiac scan is likely to be a useful assessment of bone mineral status in the general population.

Biomechanical analysis of anterior poly-methyl-methacrylate reconstruction following total spondylectomy for metastatic disease

STUDY DESIGN

Three reconstruction options were evaluated biomechanically following total spondylectomy using human cadaveric spine specimens. OBJECTIVES.: To evaluate and compare the stability of combined anterior and posterior fixation incorporating poly-methyl-methacrylate with alternative accepted reconstruction techniques.

SUMMARY OF BACKGROUND DATA

Total spondylectomy represents the most radical option for decompression in metastatic spinal cord compression. Poly-methyl-methacrylate is considered a useful adjunct in spinal column stabilization and arthrodesis; however, there is little published biomechanical data to support its use in this setting.

METHODS

Ten fresh-frozen human cadaveric spines (T9-L3) were used. After intact analysis, a total spondylectomy was performed at T12. Three potential reconstruction techniques were tested for their ability to restore stiffness to the specimen: 1) multilevel posterior pedicle screw instrumentation from T10-L2; 2) anterior instrumentation (ATL Z plate II) and rib graft at T11-L1 with multilevel posterior pedicle screw instrumentation from T10-L2; and 3) anterior cement (Simplex P) and pins construct (T12) with multilevel posterior pedicle screw instrumentation from T10-L2. Each of the three potential reconstruction techniques was tested on each specimen in random order using nondestructive testing under load control.

RESULTS

Only combined stabilization techniques (e.g., anterior instrumentation and rib graft with multilevel posterior pedicle screw instrumentation and anterior cement-and-pins construct with multilevel posterior pedicle screw instrumentation) restored stiffness to a level equivalent to or higher than that of the intact spine in all loading modes (P < 0.05). Anterior cement-and-pins construct with multilevel posterior pedicle screw instrumentation provided more stability to the specimen than anterior instrumentation and rib graft with multilevel posterior pedicle screw instrumentation in compression and flexion testing (P < 0.05). Posterior instrumentation alone did not restore stiffness to the intact level in compression and flexion testing (P < 0.005).

CONCLUSIONS

Combined anterior and posterior reconstruction using a cement construct provides equal to or more stability than the intact spine in all testing modes. Posterior stabilization alone is an inferior method of reconstruction following total spondylectomy. Poly-methyl-methacrylate has the advantage over traditional anterior reconstruction techniques in that it can be inserted using a posterior approach.

Long-term changes in the molecular composition of the glial scar and progressive increase of serotoninergic fibre sprouting after hemisection of the mouse spinal cord

The scarring process occurring after adult central nervous system injury and the subsequent increase in the expression of certain extracellular matrix molecules are known to contribute to the failure of axon regeneration. This study provides an immunohistochemical analysis of temporal changes (8 days to 1 year) in the cellular and molecular response of the Swiss mouse spinal cord to a dorsal hemisection and its correlation with the axonal growth properties of a descending pathway, the serotoninergic axons. In this lesion model, no cavity forms at the centre of the lesion. Instead, a dense fibronectin-positive tissue matrix occupies the centre of the lesion, surrounded by a glial scar mainly constituted by reactive astrocytes. NG2 proteoglycan and tenascin-C, potential axon growth inhibitors, are constantly associated with the central region. In the glial scar, tenascin-C is never observed and the expression of chondroitin sulphate proteoglycans (revealed with CS-56 and anti-NG2 antibodies) highly increases in the week following injury to progressively return to their control level. In parallel, there is an increasing expression of the polysialilated neural cell adhesion molecule by reactive astrocytes. These molecular changes are correlated with a sprouting process of serotoninergic axons in the glial scar, except in a small area in contact with the central region. All these observations suggest that while a part of the glial scar progressively becomes permissive to axon regeneration after mouse spinal cord injury, the border of the glial scar, in contact with the fibronectin-positive tissue matrix, is the real barrier to prevent axon regeneration.

Steady-State Levels of Monoamines in the Rat Lumbar Spinal Cord: Spatial Mapping and the Effect of Acute Spinal Cord Injury

Monoamines in the spinal cord are important in the regulation of locomotor rhythms, nociception, and motor reflexes. To gain further insight into the control of these functions, the steady-state extracellular distribution of monoamines was mapped in the anesthetized rat's lumbar spinal cord. The effect of acute spinal cord lesions at sites selected for high resting levels was determined over ∼1 h to estimate contributions to resting levels from tonic descending activity and to delineate chemical changes that may influence the degree of pathology and recovery after spinal injury. Measurements employed fast cyclic voltammetry with carbon fiber microelectrodes to give high spatial resolution. Monoamine oxidation currents, sampled at equal vertical spacings within each segment, were displayed as contours over the boundaries delineated by histologically reconstructed electrode tracks. Monoamine oxidation currents were found in well defined foci, often confined within a single lamina. Larger currents were typically found in the dorsal or ventral horns and in the lateral aspect of the intermediate zone. Cooling of the low-thoracic spinal cord led to a decrease in the oxidation current (to 71–85% of control) in dorsal and ventral horns. Subsequent low-thoracic transection produced a transient increase in signal in some animals followed by a longer lasting decrease to levels similar to or below that with cooling (to 17–86% of control values). We conclude that descending fibers tonically release high amounts of monoamines in localized regions of the dorsal and ventral horn of the lumbar spinal cord at rest. Lower amounts of monoamines were detected in medial intermediate zone areas, where strong release may be needed for descending activation of locomotor rhythms.

Local acute application of BDNF in the lesioned spinal cord anti-inflammatory and anti-oxidant effects

We studied the early anti-inflammatory and anti-oxidant effects of local application of BDNF after dorsal spinal cord transection in the adult rat. Both the distribution and accumulation of neutrophils and microglial cells in and around the lesion site (inflammatory response) and the accumulation of lipid peroxidation product 4-hydroxynonenal (HNE; oxidative damage) around the lesion was examined using immunohistochemical techniques. We demonstrate that BDNF application affects the microglial response in and around the lesion and results in a reduced lipid peroxidation as shown by HNE-immunoreactive staining around the lesion 48 h post-injury. The early anti-inflammatory and anti-oxidant effects of local BDNF-application into the lesioned spinal cord may contribute to the observed decreased loss of locomotor function of the hindlimbs 2 days after injury.

Distribution of anterior cortical shear strain after a thoracic wedge compression fracture

BACKGROUND CONTEXT

Vertebral compression fractures (VCFs) are a common clinical problem and may follow trauma or be pathological. Osteoporosis increases susceptibility to fracture by reducing bone mass and weakening bone architecture. Approximately 2.5 million osteoporotic fractures occur worldwide annually, usually involving the vertebrae, wrist and hip. In the United States 700,000 VCFs occur annually, causing significant morbidity, mortality and economic burden. An initial VCF often leads to subsequent VCFs. The strain distribution along the anterior cortex, the major load-bearing pathway in flexion, may be predictive of impending VCF. Regions of high strain distribution are likely to experience secondary fracture.

PURPOSE

To investigate the distribution of anterior cortical strain at, above and below an experimentally created index VCF to determine the vertebral body at risk of secondary fracture.

STUDY DESIGN

In vitro experimental study using cadaveric thoracic spinal segments.

METHODS

Seventeen thoracic spines underwent dual-energy X-ray absorptiometry (DEXA) to assess bone mineral density and were divided into T1-T3 (Subsegment 1), T4-T6 (Subsegment 2), T7-T9 (Subsegment 3) and T10-T12 (Subsegment 4). Rectangular rosette strain gauges were applied to the anterior cortices of the vertebrae of each subsegment (vertebrae in each specimen were denoted V1-superior, V2-intermediate and V3-inferior). V1 and V3 were partially embedded into polyester resin blocks, which were used to mount the specimens in a materials testing machine. Nondestructive predefect testing was performed in compression at 125 N and 250 N, followed by flexion at 1.25 Nm and 2.5 Nm. To ensure fracture reproducibility, V2 of each specimen had a trabecular defect created to a volume of 21.3+/-4.4% of the V2 centrum. Postdefect nondestructive compression and flexion were then performed in a manner similar to the predefect tests, followed by destructive testing in flexion. Anterior cortical shear strain on V1, V2 and V3, applied moments and applied flexion angle were all measured and analyzed.

RESULTS

A VCF occurred in 55 of the 59 subsegments. Fifty-one VCF (93%) were seen in V2 and 4 VCF (7%) were seen in V1. After the creation of the trabecular defect, the shear strain on V2 increased, but a comparison of the postdefect with the predefect nondestructive tests showed no significant differences. The pre- and postdefect shear strain distribution in compression and flexion was V1strain>V3strain>V2strain. Shear strain at failure was highest on V2, and in all subsegments there were significant differences between V2 and V3 (p<.05). In all subsegments there were no significant differences between V2 and V1 (p>.05) at failure with the exception of Subsegment 1 where V2 and V1 were significantly different (p<.05). The predominant strain pattern at failure was (V2strain>V1strain>V3strain V2strain>>V3strain). Using shear strain as the codeterminant of peak moment with bending stiffness and applied angle at failure, the strain on V1 was the greatest predictor (p=.0084; R2=0.78). These findings suggest that the events leading to a secondary fracture probably start before the index VCF occurs and continue with loading beyond the index VCF.

CONCLUSION

Anterior cortical strain is concentrated at the apex of a thoracic kyphotic curve. The vertebral body immediately above the index VCF has the next highest amount of strain and therefore the highest risk of secondary fracture.

Diffusely increased uptake by thoracic vertebrae on bone scintigraphy in midcourse of lung cancer irradiation: a case report

Bone scintigraphy performed on a patient during the middle of radiation therapy for an inoperable left lung malignancy showed diffusely increased uptake in the thoracic vertebrae and relatively increased uptake in the ribs of the left thorax. This bone scan finding is apparently a transient phenomenon that occurs in response to irradiation and eventually leads to photon deficiency or photopenia of the vertebrae. However, this transiently increased uptake of the thoracic spine, compared with uptake in the lumbar spine, mimics diffusely decreased uptake or photopenia of the lumbar vertebrae and may be misinterpreted as an effect of irradiation of the abdominal region. In the case of asymmetric uptake between the thoracic and lumbar spine, a carefully taken history of the timing and location of irradiation is necessary to avoid misinterpretation.

Changes in neurocan expression in the distal spinal cord stump following complete cord transection: a comparison between infant and adult rats

The distal transected cords of infant rats are more permissive for axon extension than those of adults. To elucidate the biomolecular basis for this phenomenon, we examined the expression pattern of neurocan using semi-quantitative reverse transcription polymerase chain reaction and immunostaining in the distal cord of both adult and infant rats after transection. Neurocan is a chondroitin sulfate proteoglycan with well-documented axon growth-inhibitory properties in the central nervous system. Neurocan mRNA was up-regulated in the distal cord of adult rats shortly after transection, followed by a longer wide distribution of neurocan immunoreactivity (IR) in both neurons and astrocytes; by contrast, upregulation of neurocan mRNA was not seen in infant rats, although transient expression of neurocan IR was seen in neurons. Combined with the different regenerative capacity of infant and adult rats, the present results suggest that neurocan inhibits spinal cord regeneration.

Bone metabolism and histomorphometric changes in rheumatoid arthritis

OBJECTIVE

We studied bone metabolism and histomorphometry in 66 patients with rheumatoid arthritis.

METHODS

Cross-sectional study.

RESULTS

BMD at the forearm but not at the lumbar spine was decreased. Age. body mass index and fibrinogen correlated significantly with decreased BMD, whereas age and disease duration were predictors of vertebral fractures. Biochemical parameters were normal but 25 vitamin D levels were markedly reduced. There were significant decreases in bone volume, mean wall thickness, mineral apposition rate (with highly prolonged mineralisation lag time), number of osteoclasts, and osteoclast surface, and increases in resorption surfaces. Mean plate trabecular separation and density were also deeply affected.

CONCLUSIONS

Patients with rheumatoid arthritis showed a reduced bone volume and decreased bone turnover, which is further aggravated by microarchitectural deterioration stressing the severe osteoporosis associated with the disease. These findings are consistent with the effect of hypovitaminosis D and low values of vitamin D in serum.

Heme oxygenase-1 expression after spinal cord injury: the induction in activated neutrophils

Tissue damage and neurological dysfunction after spinal cord injury may result, in part, from delayed or secondary mechanisms that appear to involve several endogenous factors. Among them, neutrophils are known to play important roles in the pathomechanisms of the secondary injury, that is, neutrophils are activated by an interaction with the endothelial cells, migrate into the damaged tissue and release several kinds of proteases or oxygen radicals. In the present study, we examined heme oxygenase-1 expression in the damaged spinal cord. The administration of an inhibitor of heme oxygenase-1 in vivo produced a delayed recovery of motor function after spinal cord injury, suggesting that heme oxygenase-1 may play roles as an endogenous anti-inflammatory enzyme and protective gene in the damaged and inflammatory tissue. We found that many neutrophils expressing heme oxygenase-1 mRNA and protein were recruited into the damaged spinal cord with extensive hemorrhages during early stage of spinal cord injury. In an in vitro study, neutrophils incubated with proinflammatory cytokines, such as interleukin-1, 6 or interferon-gamma, expressed heme oxygenase-1 mRNA and protein. Based on these findings we conclude that the activated neutrophils can express heme oxygenase-1 in the injured spinal cord tissue, perhaps expecting modulatory and neuroprotective actions in the inflammatory response to spinal cord injury.

Increased protein oxidation and decreased creatine kinase BB expression and activity after spinal cord contusion injury

Traumatic injury to the spinal cord triggers several secondary effects, including oxidative stress and compromised energy metabolism, which play a major role in biochemical and pathological changes in spinal cord tissue. Free radical generation and lipid peroxidation have been shown to be early events subsequent to spinal cord injury. In the present study, we demonstrated that protein oxidation increases in rat spinal cord tissue after experimental injury. As early as h after injury, the level of protein carbonyls at the injury epicenter was significantly higher than in control (169%, p < 0.05) and increased gradually over the next 4 weeks to 1260% of control level. Both caudal and rostral parts of the injured spinal cord demonstrated a mild increase of protein carbonyls by 4 weeks postinjury (135-138%, p < 0.05). Immunocytochemical analysis of protein carbonyls in the spinal cord cross-sections showed increased protein carbonyl immunoreactivity in the epicenter section compared to rostral and caudal sections of the same animal or control laminectomy animals. Increased protein carbonyl formation in damaged spinal cord tissue was associated with changes in activity and expression of an oxidative sensitive enzyme, creatine kinase BB, which plays an important role in the maintenance of ATP level in the CNS tissue. Damage to CK function in the CNS may severely aggravate the impairment of energy metabolism. The results of our study indicate that events associated with oxidative damage are triggered immediately after spinal cord trauma but continue to occur over the subsequent 4 weeks. These results suggest that antioxidant therapeutic strategies may be beneficial to lessen the consequences of the injury and potentially improve the restoration of neurological function.

Colonic inflammation induces fos expression in the thoracolumbar spinal cord increasing activity in the spinoparabrachial pathway

The descending colon and rectum are innervated by primary afferent fibers projecting to the lumbosacral and thoracolumbar spinal cord segments. Previous work from this laboratory has suggested that afferent input and sensory processing in the lumbosacral spinal cord is necessary and sufficient to mediate reflex responses to transient colorectal stimulation while processing in both the lumbosacral and thoracolumbar spinal cord segments contribute to visceral hyperalgesia. In the rat, repetitive noxious colorectal distention (CRD) induces >200 Fos labeled cells per section in the lumbosacral segments, but few in the thoracolumbar segments, further suggesting that transient colonic nociceptive input is transduced primarily in the lumbosacral spinal cord. The laminar distribution of this CRD-induced Fos suggests some of these neurons project to the parabrachial nucleus (PBn), an important relay for visceroceptive input from the spinal cord to higher order centers for nociceptive processing. In this study, two hypotheses were tested: first, inflammation of the colon prior to CRD would induce Fos expression in neurons in the thoracolumbar spinal cord segments and increase the number of neurons in the lumbosacral spinal cord segments that express Fos in response to noxious CRD; and second, the inflammation-induced increase in Fos expression in the spinal cord would be partially manifest as an increase in the number of spinoparabrachial projection neurons that respond to CRD. The retrograde tracer Fluorogold (FG) was injected unilaterally into the PBn of male Sprague-Dawley rats. Ten to 14 days later the rat's colon was either distended or inflamed and distended. Sections from the T13-L2 and L6-S2 spinal cord segments were double labeled using antibodies directed against FG and Fos protein. The results show that: (1) colonic inflammation plus distention induced Fos expression in the thoracolumbar spinal cord and increased Fos expression in the lumbosacral spinal cord compared to distention alone. In the lumbosacral cord, the increase in Fos expression was localized primarily to the superficial dorsal horn (SDH). In the thoracolumbar spinal segments, Fos was induced primarily in the SDH and the area around the central canal. (2) Injection of FG into the PBn produced dense retrograde labeling in the SDH, the lateral deeper gray matter and the area around the central canal at the lumbosacral and thoracolumbar levels. (3) In the lumbosacral spinal cord, 30-40% of the FG labeled cells double labeled for Fos. Colonic inflammation plus CRD did not significantly increase the percentage of spinoparabrachial neurons that were labeled for Fos compared to distention alone. (4) In the thoracolumbar spinal cord less than 10% of the FG labeled neurons were double labeled for Fos following CRD, but 25% of the FG labeled neurons in the SDH were double labeled following colonic inflammation. These data support the hypothesis that colonic inflammation activates viscerosensory processing in the thoracolumbar spinal cord and further suggests that this information is relayed to the PBn. The increase in information reaching the PBn over these parallel pathways may contribute to the affective-motivational component of the pain experience.

Effects of trapidil on ATPase, lipid peroxidation, and correlation with ultrastructure in experimental spinal cord injury

The present study was performed to investigate the effect of trapidil on ischemic damage of cells after spinal cord injury. The injury was produced by extradural clip compression of the exposed spinal cord in rats according to Rivlin and Tator. The ten rats in group 1 were used to determine normal findings without any surgery or medication. On the 15 rats in group 2, only six-level laminectomy was performed to determine the influence of the total laminectomy on the biochemical factors measured and the, light and ultrastructural findings. The 15 rats each in groups 3 and 4 were used as trauma and trapidil (40 mg/kg) treatment groups, respectively. The injury actually produced a significant decrease in Na+-K+/Mg+2 ATPase activity of the injured segments as early as 10 min after trauma. Trapidil attenuated Na+-K+/Mg+2 ATPase inactivation in the traumatized rats for 120 min after treatment (P<0.05) and significantly reduced the malone dialdehyde content below that in the traumatized group at all determined times (P<0.05). Light and electron microscopic findings supported the biochemical results.

Inhomogeneity of human vertebral cancellous bone: systematic density and structure patterns inside the vertebral body

In the spine, cancellous bone quality is usually assessed for the whole vertebral body in a transverse central slice. Correct identification and assessment of the weakest parts of the cancellous bone may lead to better prediction of fracture risk. The density and structural parameters were systematically investigated inside the thoracic (T-9), thoracolumbar (T12-L1), and lumbar (L-4) vertebral bodies of nine subjects. On both sides of the median sagittal plane, anterior and posterior 8.2 mm vertical cores were harvested in the thoracic vertebra. In the thoracolumbar and lumbar vertebrae, external samples were also cored. Peripheral quantitative computed tomographic (pQCT) density analysis of the 136 cores was performed at four different levels, from the lower to the upper endplate. The relatively thin slice thickness (300 microm) and small pixel size (70 microm x 70 microm) was considered sufficient to investigate the structural parameters on the four transverse slices and in the sagittal and coronal planes (total of 816 images). Using a constant threshold a binary image was generated and the morphometric data were extracted. The binary image was further skeletonized and classical strut analysis was performed. Cancellous bone density was 20% higher in the posterior cores than in the anterior and external cores. Moreover, clear vertical inhomogeneity was noted because the lowest half of the vertebral body presented lower density than the upper half (differences ranging from 25% to 15%). All structural parameters were strongly dependent on the location of the measurement. Structural differences between anterior, posterior, and external areas were mild and followed the density patterns. On the other hand, vertical inhomogeneity of the structural parameters was important. For example, in the thoracolumbar and lumbar vertebrae, the numbers of nodes or node-to-node struts were almost twofold higher in the inferior half than in the superior half (p < 0.01), whereas trabecular thickness and number of free-ends presented a center/close-to-endplate structural pattern, with central trabeculae being 15% thicker (p < 0.05) and presenting 30% fewer free-ends (p < 0.01) than the close-to-endplate ones. Variability of density and structural parameters was high and a substantial part of this variability could be explained by the place inside the vertebral body where the measurement was made. The weak part was not in the center of the body but in its upper half where the lower density did not seem to be compensated by a higher structural architecture. Further clinical investigation could enhance fracture prediction by tracking and focusing on the weakest part of the vertebral body.

[Changes in bone mineral density in Th12 to L5 vertebrae in female patients with osteoporosis]

The authors examined 47 female patients, age 50-60 years, with primary and secondary osteopenia and osteoporosis. In each patients they assessed the bone mineral density (BMD) of the cortical and trabecular bone of vertebrae Th12 to L5 by quantitative computer tonmography (QTC). They did not include in the group patients with deformities of the vertebrae grade one, two and three. These deformities were assessed from a lateral X-ray of the thoracic and lumbar spine.

OBJECTIVE

To evaluate the importance of assessed BMD values of vertebrae from the biomechanical aspect.

STATISTICAL ANALYSIS

Individual groups of assessment of BMD in cortical and trabecular bone for each vertebra were characterized by means of 95% confidence intervals and their means or median values.

RESULTS

The BMD of cortical bone increases from Th12 to L5 almost in a linear fashion. BMD of the trabecular bone declines from Th12 to L3, in L4 abd L5 it rises again. The lowest values were recorded in L3. The greatest decline of BMD of the trabecular bone by 24.05% in L3 as compared with reference values of the given age groups were not conditioned by deformities of the vertebrae. The BMD of cortical bone in osteopenic and osteoporotic patients practically did not differ from reference values for the given age group.

CONCLUSION

From the presented work ensues that deformities of the vertebrae do not occur as long as the BMD of cortical bone is within the range of reference values despite a decline of BMD in trabecular bone. It is thus more important to investigate the material qualities of cortical bone because the risk of fractures of the vertebrae depends on the elasticity and firmness. Critical BMD values of cortical bone assessed by QCT for the development of fractures are not known so far. QTC of vertebrae due to its higher radiation load and financial costs is not a routine densitometric method. It will be necessary to develop new densitometric methods which will make it possible to assess BMD or another property of cortical bone and assess critical values for the development of vertebral fractures.

Unbiased determination of cytokine localization in bone: colocalization of interleukin-6 with osteoblasts in serial sections from monkey vertebrae

Few data are available describing the in vivo localization of cytokines in bone. The objective of this study was to describe the histological localization of interleukin-6 (IL-6) relative to osteoblasts (alkaline phosphate [ALP]-positive cells) and osteoclasts (tartrate-resistant acid phosphate [TRAP]-positive cells) in midsagittal, paraffin-embedded serial sections of thoracic 13 (T-13) vertebrae from 49 female cynomolgus monkeys. Serial sections 1 and 4 were immunostained for IL-6, section 2 was histochemically stained for TRAP, and section 3 was immunostained for ALP. Sixteen centrally located fields were measured in the cancellous compartment and grid alignment among sections was verified using image analysis. Using a Merz grid, IL-6 localized to 6% of the bone surface on sections 1 and 4, whereas TRAP localized to 8.5% and ALP to 12% of the bone surface. Colocalization was defined as positive staining within an 80 x 80 microm block in the first serial section that "overlapped" staining in either the corresponding block or its eight surrounding blocks within the second serial section. For each section, 1600 blocks were analyzed. Using Monte Carlo simulations, random colocalization was calculated to determine the statistical significance of experimental colocalizations. Colocalization of approximately 90% between the two IL-6 sections verified staining reproducibility and proper grid alignment among sections. Colocalization of TRAP and ALP was not statistically different from random (p 0.3). As identified using ALP- or TRAP-positive surfaces, there was significant IL-6 colocalization with osteoblasts (p < 0.003), but not with osteoclasts (p 0.3). These in vivo colocalization data support the hypothesis that osteoblasts produce and respond to IL-6.