Rational Design of Amphipathic Antimicrobial Peptides with Alternating L-/D-Amino Acids That Form Helical Structures

Antimicrobial peptides (AMPs) are promising therapeutic agents against bacteria. We have previously reported an amphipathic AMP Stripe composed of cationic L-Lys and hydrophobic L-Leu/L-Ala residues, and Stripe exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria. Gramicidin A (GA), composed of repeating sequences of L- and D-amino acids, has a unique β6.3-helix structure and exhibits broad antimicrobial activity. Inspired by the structural properties and antimicrobial activities of LD-alternating peptides such as GA, in this study, we designed Stripe derivatives with LD-alternating sequences. We found that simply alternating L- and D-amino acids in the Stripe sequence to give StripeLD caused a reduction in antimicrobial activity. In contrast, AltStripeLD, with cationic and hydrophobic amino acids rearranged to yield an amphipathic distribution when the peptide adopts a β6.3-helix, displayed higher antimicrobial activity than AltStripe. These results suggest that alternating L-/D-cationic and L-/D-hydrophobic amino acids in accordance with the helical structure of an AMP may be a useful way to improve antimicrobial activity and develop new AMP drugs.

Magainin 2-derived stapled peptides derived with the ability to deliver pDNA, mRNA, and siRNA into cells

We have developed cell-penetrating stapled peptides based on the amphipathic antimicrobial peptide magainin 2 for intracellular delivery of nucleic acids such as pDNA, mRNA, and siRNA. Various types of stapled peptides with a cross-linked structure were synthesised in the hydrophobic region of the amphipathic structure, and their efficacy in intracellular delivery of pDNA was evaluated. The results showed that the stapled peptide st7-5 could deliver pDNA into cells. To improve the deliverability of st7-5, we further designed st7-5_R, in which the Lys residues were replaced by Arg residues. The peptide st7-5_R formed compact and stable complexes with pDNA and was able to efficiently transfer pDNA into the cell. In addition to pDNA, st7-5_R was also able to deliver mRNA and siRNA into the cell. Thus, st7-5_R is a novel peptide that can achieve efficient intracellular delivery of three different nucleic acids.

Development of Hydrophobic Cell-Penetrating Stapled Peptides as Drug Carriers

Cell-penetrating peptides (CPPs) are widely used for the intracellular delivery of a variety of cargo molecules, including small molecules, peptides, nucleic acids, and proteins. Many cationic and amphiphilic CPPs have been developed; however, there have been few reports regarding hydrophobic CPPs. Herein, we have developed stapled hydrophobic CPPs based on the hydrophobic CPP, TP10, by introducing an aliphatic carbon side chain on the hydrophobic face of TP10. This side chain maintained the hydrophobicity of TP10 and enhanced the helicity and cell penetrating efficiency. We evaluated the preferred secondary structures, and the ability to deliver 5(6)-carboxyfluorescein (CF) as a model small molecule and plasmid DNA (pDNA) as a model nucleotide. The stapled peptide F-3 with CF, in which the stapling structure was introduced at Gly residues, formed a stable α-helical structure and the highest cell-membrane permeability via an endocytosis process. Meanwhile, peptide F-4 demonstrated remarkable stability when forming a complex with pDNA, making it the optimal choice for the efficient intracellular delivery of pDNA. The results showed that stapled hydrophobic CPPs were able to deliver small molecules and pDNA into cells, and that different stapling positions in hydrophobic CPPs can control the efficiency of the cargo delivery.

Rational Design of Helix-Stabilized Antimicrobial Peptide Foldamers Containing α,α-Disubstituted Amino Acids or Side-Chain Stapling

Antimicrobial peptides (AMPs) are expected to be good candidate molecules for novel antimicrobial therapies. Most AMPs exert their antimicrobial activity through disruption of microbial membranes due to their amphipathic properties. Recently, the helical peptide 'Stripe' was reported by our group, a rationally designed amphipathic AMP focused on distribution of natural cationic and hydrophobic amino acid residues. In this study, a set of Stripe-based AMP foldamers was designed, synthesized and investigated that contain α,α-disubstituted amino acids or side-chain stapling to stabilize their helical structures. Our results showed that a peptide containing 2-aminoisobutyric acid (Aib) residues exhibited potent antimicrobial activity against both Gram-positive S.aureus (MIC value: 3.125 μM) and Gram-negative bacteria (including a multidrug-resistant strain, MDRP, MIC value: 1.56 μM), without significant hemolytic activity (>100 μM). Electrophysiological measurements revealed that this peptide formed stable pores in a 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)/1,2-dioleoyl-sn-glycero-3-phosphoglycerol (DOPG) bilayer but not in a dioleoylphosphocholine (DOPC) bilayer. The introduction of Aib residues into Stripe could be a promising way to increase the antimicrobial activity of AMP foldamers, and the peptide could represent a promising novel therapeutic candidate to treat multidrug-resistant bacterial infection.

Structure-activity relationship study of amphipathic antimicrobial peptides using helix-destabilizing sarcosine

Antimicrobial peptides (AMPs) are potential therapeutic agents against bacteria. We recently showed that a rationally designed AMP, termed Stripe, with an amphipathic distribution of native cationic and hydrophobic amino acids on its helical structure exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria with negligible hemolytic activity and cytotoxicity. In this study, the structure-activity relationship of Stripe was elucidated by designing a series of antimicrobial peptides whereby amino acid residues of Stripe were exchanged with helix-destabilizing sarcosine residues. Stripe 1-5 peptides with hydrophobic amino acids substituted with sarcosine were predominantly unstructured and showed no antimicrobial activity, except against Escherichia coli (E. coli) (DH5α) cells. The activity against E. coli (DH5α) cells and the helicity of Stripe 1-5 peptides decreased concomitantly as the number of sarcosine residue substitutions increased. Stripe 1-5 peptides showed no hemolytic activity or cytotoxicity. The results indicate that sarcosine substitutions provide an approach to study the structure-activity relationship of helical AMPs, and the helicity of Stripe is an important feature defining its activity.

Helical Antimicrobial Peptide Foldamers Containing Non-proteinogenic Amino Acids

Antimicrobial peptides (AMPs) are potential novel therapeutic drugs against microbial infections. Most AMPs function by disrupting microbial membranes because of their amphipathic properties and ordered secondary structures. In this minireview, we describe recent efforts to develop helical AMP foldamers containing non-proteinogenic amino acids, such as α,α-disubstituted α-amino acids, β-amino acids, γ-amino acids, side-chain stapling and N-alkyl glycines.

Development of Antimicrobial Stapled Peptides Based on Magainin 2 Sequence

Magainin 2 (Mag2), which was isolated from the skin of the African clawed frog, is a representative antimicrobial peptide (AMP) that exerts antimicrobial activity via microbial membrane disruption. It has been reported that the helicity and amphipathicity of Mag2 play important roles in its antimicrobial activity. We investigated and recently reported that 17 amino acid residues of Mag2 are required for its antimicrobial activity, and accordingly developed antimicrobial foldamers containing α,α-disubstituted amino acid residues. In this study, we further designed and synthesized a set of Mag2 derivatives bearing the hydrocarbon stapling side chain for helix stabilization. The preferred secondary structures, antimicrobial activities, and cell-membrane disruption activities of the synthesized peptides were evaluated. Our analyses revealed that hydrocarbon stapling strongly stabilized the helical structure of the peptides and enhanced their antimicrobial activity. Moreover, peptide 2 stapling between the first and fifth position from the N-terminus showed higher antimicrobial activity than that of Mag2 against both gram-positive and gram-negative bacteria without exerting significant hemolytic activity. To investigate the modes of action of tested peptides 2 and 8 in antimicrobial and hemolytic activity, electrophysiological measurements were performed.

Ovarian reserve may influence the outcome of bone mineral density in patients with long-term use of dienogest

Objective:

Long-term administration of dienogest, which is known to have effect on bone mineral density, is frequently done in patients with endometriosis and adenomyosis, but a few studies focused on the bone mineral density changes after finishing the long-term therapy. This study aimed to reveal the factors that adversely affect lumbar bone mineral density.

Method:

Fifty-seven premenopausal women who visited our hospital were diagnosed as either endometriosis or adenomyosis, and they were treated by dienogest for more than 115 weeks (26.5 months). Based on a previous report, bone mineral density changes less than 2% was categorized as the osteopenic group ( n = 30), and the others were assigned to the unchanged group ( n = 27). Bone mineral density was measured at the lumbar spine using dual-energy X-ray absorptiometry. A representative ovarian reserve marker, endogenous estradiol levels, and follicle-stimulating hormone levels were measured over time and were compared between the osteopenic and unchanged groups.

Result:

Duration of dienogest intake was 59.5 months (osteopenic group) versus 57.5 months (unchanged group). These patients experienced ovarian surgeries in a similar frequency, but the ovarian reserve in osteopenic group was impaired as suggested by the decline of endogenous estradiol level during intake of dienogest compared to that of unchanged group ( p = 0.0146). Endogenous follicle-stimulating hormone level between osteopenic group and unchanged group did not reach statistically significant difference, although the osteopenic group showed relatively higher level.

Conclusion:

This study might suggest that decreased ovarian reserve as judged by endogenous estradiol level is a factor that negatively affect bone mineral density, and measurement of endogenous estradiol level during intake of dienogest could have a predictive meaning of future decreased bone mineral density level.

Status of fracture risk assessment and osteoporosis treatment in Japanese patients with rheumatoid arthritis

OBJECTIVES

This study aimed to investigate the prevalence of patients with rheumatoid arthritis (RA) at a high risk of major osteoporosis (OP)-related fractures and the status of OP-related medical treatment for these patients.

METHODS

We enrolled 120 patients aged ≥40 years (average, 69.1 years) with RA. The Fracture Risk Assessment Tool (FRAX^®) was used to evaluate the fracture risk. Of the 120 patients, the femoral neck bone mineral density (BMD) was evaluated in 102 patients, and their FRAX^® scores were calculated alongside the BMD values. Patients observed to be at a high risk of a major OP-related fracture (10-year probability >20% or hip fracture risk >3%), according to FRAX^®, were identified as those requiring OP treatment; medication ratio for OP (percentage of patients actually receiving medication among patients requiring OP treatment) was assessed.

RESULTS

OP treatment was indicated in 75 (63%) patients; the medication ratio for OP was 49%. The use of biological disease-modifying anti-rheumatic drugs and corticosteroids showed a positive effect; however, the use of methotrexate showed a negative effect on the medication ratio.

CONCLUSION

The number of potential patients requiring OP treatment is underestimated. All patients with RA should be assessed to determine their eligibility for OP treatment.

Overcoming the ceiling effects of experts' motor expertise through active haptic training

One of the most challenging issues among experts is how to improve motor skills that have already been highly trained. Recent studies have proposed importance of both genetic predisposition and accumulated amount of practice for standing at the top of fields of sports and performing arts. In contrast to the two factors, what is unexplored is how one practices impacts on experts' expertise. Here, we show that training of active somatosensory function (active haptic training) enhances precise force control in the keystrokes and somatosensory functions specifically of expert pianists, but not of untrained individuals. By contrast, training that merely repeats the task with provision of error feedback, which is a typical training method, failed to improve the force control in the experts, but not in the untrained. These findings provide evidence that the limit of highly trained motor skills could be overcome by optimizing training methods.

Development of Amphipathic Antimicrobial Peptide Foldamers Based on Magainin 2 Sequence

Magainin 2 (Mag 2), which is isolated from the skin of frogs, is a representative antimicrobial peptide (AMP), exerts its antimicrobial activity via microbial membrane disruption. It has been reported that both the amphipathicity and helical structure of Mag 2 play an important role in its antimicrobial activity. In this study, we revealed that the sequence of 17 amino acid residues in Mag 2 (peptide 7) is required to exert sufficient activity. We also designed a set of Mag 2 derivatives, based on enhancement of helicity and/or amphipathicity, by incorporation of α,α-disubstituted amino acid residues into the Mag 2 fragment, and evaluated their preferred secondary structures and their antimicrobial activities against both Gram-positive and Gram-negative bacteria. As a result, peptide 11 formed a stable helical structure in solution, and possessed potent antimicrobial activities against both Gram-positive and Gram-negative bacteria without significant cytotoxicity.

Rational design of novel amphipathic antimicrobial peptides focused on the distribution of cationic amino acid residues

Antimicrobial peptides (AMPs) have garnered much attention as novel therapeutic agents against infectious diseases. They exhibit antimicrobial activity through microbial membrane disruption based on their amphipathic properties. In this study, we rationally designed and synthesized a series of novel AMPs Block, Stripe, and Random, and revealed that Stripe exhibits potent antimicrobial activity against Gram-positive and Gram-negative microbes. Moreover, we also demonstrated that Stripe disrupts both Gram-positive and Gram-negative mimetic bacterial membranes. Finally, we investigated the hemolytic activity and cytotoxicity in human blood cells and human cell lines, and found that Stripe exhibited neither. These data indicated that Stripe is a promising antimicrobial reagent that does not display significant cytotoxicity.

Cerebral Mitochondrial Microangiopathy Leads to Leukoencephalopathy in Mitochondrial Neurogastrointestinal Encephalopathy

BACKGROUND AND PURPOSE

Mitochondrial neurogastrointestinal encephalopathy is a rare disorder due to recessive mutations in the thymidine phosphorylase gene, encoding thymidine phosphorylase protein required for mitochondrial DNA replication. Clinical manifestations include gastrointestinal dysmotility and diffuse asymptomatic leukoencephalopathy. This study aimed to elucidate the mechanisms underlying brain leukoencephalopathy in patients with mitochondrial neurogastrointestinal encephalopathy by correlating multimodal neuroradiologic features to postmortem pathology.

MATERIALS AND METHODS

Seven patients underwent brain MR imaging, including single-voxel proton MR spectroscopy and diffusion imaging. Absolute concentrations of metabolites calculated by acquiring unsuppressed water spectra at multiple TEs, along with diffusion metrics based on the tensor model, were compared with those of healthy controls using unpaired t tests in multiple white matters regions. Brain postmortem histologic, immunohistochemical, and molecular analyses were performed in 1 patient.

RESULTS

All patients showed bilateral and nearly symmetric cerebral white matter hyperintensities on T2-weighted images, extending to the cerebellar white matter and brain stem in 4. White matter, N-acetylaspartate, creatine, and choline concentrations were significantly reduced compared with those in controls, with a prominent increase in the radial water diffusivity component. At postmortem examination, severe fibrosis of brain vessel smooth muscle was evident, along with mitochondrial DNA replication depletion in brain and vascular smooth-muscle and endothelial cells, without neuronal loss, myelin damage, or gliosis. Prominent periependymal cytochrome C oxidase deficiency was also observed.

CONCLUSIONS

Vascular functional and histologic alterations account for leukoencephalopathy in mitochondrial neurogastrointestinal encephalopathy. Thymidine toxicity and mitochondrial DNA replication depletion may induce microangiopathy and blood-brain-barrier dysfunction, leading to increased water content in the white matter. Periependymal cytochrome C oxidase deficiency could explain prominent periventricular impairment.

Clinical characteristics of methotrexate-associated lymphoproliferative disorders: relationship between absolute lymphocyte count recovery and spontaneous regression

Several reports have shown that patients with rheumatoid arthritis (RA) are at increased risk of developing lymphoproliferative disorders (LPD). Methotrexate (MTX) has been recognized as a major cause of LPD. Sometimes spontaneous regression (SR) occurs after withdrawal of MTX. Recent studies suggest that the early recovery of the absolute lymphocyte count (ALC) after withdrawal of MTX is associated with the spontaneous regression of MTX-LPD. We retrospectively analyzed 26 patients with MTX-LPD to identify predictive factors for spontaneous regression. The spontaneous regression after withdrawal of MTX occurred in 13 of 26 (50%) cases. We assessed the ALC at the time of MTX cessation and 1 month after cessation in 23 evaluable cases. The spontaneous regression was observed in 3 of 11 in the ALC recovery group (27%) and in 8 of the 12 in the ALC non-recovery group (67%). Thus, we could not detect any relationship between the recovery of ALC after withdrawal of MTX and the spontaneous regression. The patients in the ALC recovery group had a poorer prognosis than those in the ALC non-recovery group (2-year overall survival: 65.6 vs. 100%, p = 0.05). According to these results, the recovery of the ALC might not be useful as a predictor of the spontaneous regression. Furthermore, the existence of extranodal sites and advanced-stage were associated with non-SR. It is suspected that MTX-LPD patients with high disease activity at the time of their diagnosis might have little hope of spontaneous regression. This result indicated the importance of the early detection of MTX-LPD.

Examination of Visceral Perception and Gastric Tone by Gastric Stimulation Using Air Inflation during Endoscopy

This study investigated the assessment of visceral perception and gastric tone using insufflation during endoscopy. The intragastric pressure was measured during insufflation in 16 patients with gastro-oesophageal reflux disease, 25 patients with functional dyspepsia and 24 normal controls, using a pressure transducer inserted through the forceps aperture until gastric symptoms appeared. The intragastric pressure at the visceral perception threshold, the time to threshold and the time-pressure curve gradient were measured. The visceral perception threshold was significantly reduced in the functional dyspepsia group compared with the normal controls. Balloons were also inserted into the duodenal bulbs of 10 normal controls to investigate the effect of efflux of air into the duodenum; the measured parameters were not influenced by inflation and deflation. These results suggest that it is possible to assess visceral perception and gastric tone by measuring changes in intragastric pressure, using gastric stimulation by insufflation during endoscopy.

Liposome chaperon in cell-free membrane protein synthesis: one-step preparation of KcsA-integrated liposomes and electrophysiological analysis by the planar bilayer method

Chaperoning functions of liposomes were investigated using cell-free membrane protein synthesis.

Cytochemical studies of nuclear DNA and RNA in normal and abnormal keratinizing tissues

The distribution patterns of nuclear DNA and RNA in normal and abnormal keratinizing tissues of human skin were examined by electron microscopy, using an enzyme digestion technique. We found that the distribution of nucleic acids in the nuclei of epidermal cells during keratinization changes gradually. In the hair cells, particularly in the cells of hair cortex and Henle's layer of inner root sheath, essentially similar findings were observed. On the other hand, the distribution patterns observed in the tumor cells of calcifying epithelioma and the parakeratotic cells of psoriasis were different from each other and different from the distribution patterns of normal keratinizing tissue, hair, and epidermis. It seems that a similar pattern of reorganization of nucleic acids occurs in the nucleic of normal keratinizing cells as the cells keratinize. However, in abnormal tissue, it seems that the reorganization pattern of nucleic acids in the nuclei is different in each case.

Pharmacokinetics of everolimus when combined with cyclosporine in Japanese de novo renal transplant recipients

BACKGROUND

Currently, there are no published data on pharmacokinetics (PK) of everolimus in combination with cyclosporine in Japanese renal transplant patients. We evaluated the PK of everolimus in Japanese de novo renal transplant patients who received everolimus in combination with cyclosporine.

METHODS

In this phase 3, multicenter, randomized, open-label study, patients were randomized (1:1) to 1 of the 2 groups: everolimus 1.5 mg (targeted C0 of 3-8 ng/mL) plus reduced-dose cyclosporine or mycophenolate mofetil 2 g/d plus standard-dose cyclosporine. PK assessments for everolimus were performed on day 28 (month 1) in the PK subpopulation.

RESULTS

A total of 11 patients (7 men), mean age 47.5 ± 11.21 years, were enrolled for PK analysis of everolimus. Starting at 1.5 mg (0.75 mg twice a day), the mean dose over a period of 28 days was 0.705 ± 0.1011 mg. Everolimus mean trough concentration was 4.307 ± 1.2459 ng/mL and mean peak concentration was 13.539 ± 3.5330 ng/mL, which peaked at 1 to 2 hours postdose. The average concentration was 7.558 ± 1.4723 ng/mL, area under the concentration-time curve was 90.70 ± 17.667 ng·h/mL, and peak-trough fluctuation was 122.6%. The PK parameters of everolimus were comparable to those in the earlier phase 3 studies (A2306 and A2307). The mean everolimus trough levels were within the target ranges at all time points ranging from 3.4 to 5.5 ng/mL (everolimus 0.75 mg twice a day, safety population). The majority of patients (>85% from day 7 onward) were maintained within the targeted everolimus trough blood levels (safety population). These data were similar to a non-Japanese study (A2309).

CONCLUSIONS

The pharmacokinetic characteristics of everolimus in Japanese de novo renal transplant patients did not differ from those previously observed in non-Japanese patients, hence the same dosage of everolimus may be acceptable in Japanese patients.

1306-km 20x124.8-Gb/s PM-64QAM transmission over PSCF with net SEDP 11,300 (b ∙ km)/s/Hz using 1.15 samp/symb DAC

We demonstrated the transmission of a Nyquist-WDM signal based on PM-64QAM modulation in an EDFA-only submarine configuration composed of 54.4 km-long fiber spans: 20 channels at 124.8-Gb/s were propagated over 1306 km of low-loss pure-silica-core fiber (PSCF). Thanks to an aggressive digital spectral shaping, we achieved a raw spectral efficiency (SE) of 10.4 b/s/Hz, corresponding to 8.67 b/s/Hz net SE when considering a 20% FEC overhead. Transmitter DACs are operated at a record-low 1.15 samples/symbol, enabled by the insertion of advanced anti-alias filters. The achieved SE-times-distance product was 11,327 (b ∙ km)/(s ∙ Hz), the highest reported so far for PM-64QAM. Combining the experimental results with the performance predictions obtained using an analytical model of nonlinear propagation in uncompensated coherent optical systems (the so-called "GN-model"), we show that PM-64QAM is a realistic option for ultra-high capacity systems in the 1,000 km range, carrying up 40 Tb/s in the C-band.

In not only vertebroplasty but also kyphoplasty, the resolution of vertebral deformities depends on vertebral mobility

BACKGROUND AND PURPOSE

It has not been clarified whether the postoperative resolution of vertebral deformities achieved by KP are superior to those achieved by VP. We compared the outcomes of KP and VP, taking into account the presence of vertebral mobility, to determine whether the balloon inflation in KP may contribute to postoperative resolution of the vertebral deformities in patients with VCFs.

MATERIALS AND METHODS

The subjects had 34 vertebral bodies treated by VP, and 43 vertebral bodies treated by KP. In all patients, preoperative dynamic imaging was performed to assess the presence of vertebral mobility. First, the vertebral height restoration and kyphotic change were compared between the VP and KP groups. Then, the patients were further divided into 2 groups on the basis of the presence of vertebral mobility, and they were compared within and between the VP and KP groups in relation to the presence of vertebral mobility.

RESULTS

Overall, no significant differences were observed in either the vertebral height restoration or kyphotic change between the VP and KP groups (P > .20). Preoperative dynamic imaging identified 19 vertebral bodies each with vertebral mobility in the VP (56%) and KP groups (44%) (P = .21). Within the VP and KP groups, the vertebral height restoration and kyphotic changes were significantly better in patients with vertebral mobility than in those without (P < .01). There were no significant differences between the 2 treatment groups after adjustment for the presence of vertebral mobility (P > .30).

CONCLUSIONS

In both the VP and KP groups, the vertebral height restoration and kyphotic change largely depended on the preoperative vertebral mobility. The use of the balloon itself contributed little to resolution of the vertebral deformities.

Validity of intervertebral bone cement infusion for painful vertebral compression fractures based on the presence of vertebral mobility

BACKGROUND AND PURPOSE

It is uncertain whether analgesic effects of vertebroplasty in patients with painful VCF are actually attributable to intervertebral cement infusion. This study aims to assess the validity of cement infusion performed for pain relief based on the presence or absence of pseudoarthrosis.

MATERIALS AND METHODS

We compared therapeutic effects between PVP and vertebral perforation without bone cement infusion in patients with painful VCF. The subjects were 64 patients undergoing PVP (PVP group) and 67 undergoing vertebral perforation (perforation group). In all patients, preoperative dynamic radiography was performed to assess the presence of vertebral mobility. Patients were classified into 2 groups, those with and those without vertebral mobility, and changes in VAS and ADL scores before and after surgery were compared between the PVP and perforation groups.

RESULTS

Regarding patients with vertebral mobility, VAS improved during the 3 months immediately after surgery in the PVP group compared with the perforation group (P < .05). Although no significant difference in postoperative ADL scores was observed between the 2 treatment groups, the scores 3 months after surgery were better in the PVP group than in the perforation group. Meanwhile, in the subgroup of patients without vertebral mobility, both treatments produced marked pain relief, but the difference was not significant (P > .05). Moreover, there was no difference in ADL scores between the 2 treatment groups.

CONCLUSIONS

Intervertebral cement infusion exerts analgesic effects in patients with VCF with pseudoarthrosis. However, in those without vertebral mobility, the analgesic effects of vertebroplasty are the same regardless of bone cement infusion.