Lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain

Objectives

Intradiscal gas can herniate to the epidural space, and herniated epidural gas may produce pseudocysts. We assessed the characteristics of and surgical treatments for lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain.

Methods

We surgically treated epidural gas-containing pseudocysts in a total of 22 patients. We reviewed radiological parameters including the concomitant presence of vacuum discs, segmental instability, spinal stenosis, and location of pseudocysts. We retrospectively reviewed preoperative clinical parameters such as age, sex, clinical symptoms, neurologic deficits, and surgical methods.

Results

We observed 25 levels of gas-containing pseudocysts in 22 patients. Twelve (48.0%) pseudocysts were in the canal, eight (32.0%) were in the foramen, and five (20.0%) were of extraforaminal type. All of the patients had degenerative vacuum discs in the affected levels. The incidence of neurologic deficits in patients with spinal stenosis was significantly higher than in patients without spinal stenosis (P < 0.05).We performed pseudocyst removal, neural decompression, and fusion surgery in 12 patients with symptomatic spinal stenosis or instability, and microscopic removal of pseudocysts in 10 patients without symptomatic spinal stenosis or instability.

Conclusion

We propose that lumbar gas-containing pseudocysts can produce radicular pain and/or neurologic symptoms, and that surgical removal of pseudocysts with or without optimal stabilization operations can significantly improve symptoms. The selection of surgical methods may depend on the presence of concomitant spinal stenosis or segmental instability.     

Clinical Validation of the ISGPF Classification and the Risk Factors of Pancreatic Fistula Formation Following Duct-to-Mucosa Pancreaticojejunostomy by One Surgeon at a Single Center

Background  

Postoperative pancreatic fistula remains a troublesome complication after pancreatoduodenectomy (PD), and many authors have suggested factors that affect pancreatic leakage after PD. The International Study Group on Pancreatic Fistula (ISGPF) published a classification, but the new criteria adopted have not been substantially validated. The aims of this study were to validate the ISGPF classification and to analyze the risk factors of pancreatic leakage after duct-to-mucosa pancreatojejunostomy by a single surgeon.     

Impact of ischemia on left ventricular dyssynchrony by phase analysis of gated single photon emission computed tomography myocardial perfusion imaging

Background

There is increasing awareness of the value of phase analysis of gated tomographic myocardial perfusion imaging in assessing left ventricular (LV) dyssynchrony. A concern repeatedly raised in many studies is whether reversible defects in the stress images “ischemia” could affect the phase-derived standard deviation and bandwidth, the two commonly used dyssynchrony indices. We hypothesized that the stress and rest images should provide comparable information because the images are acquired 1 hour after the tracer injection.

Methods and Results

We studied two groups of patients with normal LV ejection fraction and no fixed perfusion defects. In group-1 (N = 20), the patients had reversible perfusion defects involving > 10% of the LV myocardium and in group-2 (N = 20), the patients had normal images. All patients underwent stress/rest-gated single photon emission computed tomography sestamibi imaging (the stress study was acquired with the lower dose) between January and March 2010. Patients with left bundle branch block or ventricular pacing were excluded. The patients in group-1 had a mean age of 61 ± 9 years, 65% were men, 75% Caucasians, and 70% had known prior coronary artery disease. The size of the reversible perfusion defect was 20 ± 13% (range 11%-50%) of the LV myocardium. The rest and stress phase-derived standard deviation (16 ± 6° vs 18 ± 8° and 16 ± 7° vs. 19 ± 6°) and the rest and stress bandwidth (42 ± 14° vs 46 ± 16° and 45 ± 17° vs 52 ± 12°), respectively, (P = NS for all) were similar in the two groups. The change (stress–rest) in standard deviation and bandwidth in groups 1 and 2 were not statistically significant (0.2 ± 3.1° vs 1.4 ± 4.7°, and 2 ± 13° vs 5 ± 13°, respectively, P = NS). There was no significant change from rest to stress in the standard deviation and the bandwidth in group-1 (P = .8 and .4, respectively) and group-2 (P = .2 and .08, respectively). There was no correlation between the size of the reversible perfusion defect and the change in phase standard deviation or bandwidth (r = 0.07 and 0.12, respectively, P = NS).

Conclusions

The presence of even a large reversible perfusion defect does not alter the indices of mechanical dyssynchrony by phase analysis. Further, comparable information is obtained whether using a low dose or a high dose of the radiotracer.     

The effect of topiramate monotherapy on bone mineral density and markers of bone and mineral metabolism in premenopausal women with epilepsy

Purpose: To investigate the effect of topiramate on bone mass and metabolism in premenopausal women with epilepsy. Methods: Thirty‐six women on long‐term (at least 1 year) topiramate monotherapy were compared with 36 women taking carbamazepine, 32 women taking valproate, and 36 age‐ and sex‐matched controls. Subjects completed bone mineral density (BMD) studies. Serum was analyzed for indices of bone metabolism. Key Findings: BMD Z‐scores, and serum 25‐hydroxyvitamin D and 1alpha,25‐dihydroxyvitamin D₃ concentrations did not differ among the groups. Serum calcium concentrations were significantly lower in patients receiving topiramate than in those receiving valproate, and in patients receiving carbamazepine than in those receiving valproate and controls. Patients taking topiramate had lower levels of parathyroid hormone compared with controls and those taking carbamazepine or valproate. Patients receiving topiramate had higher levels of bone‐specific alkaline phosphatase and osteocalcin when compared with controls and higher levels of C‐terminal telopeptide of type 1 collagen when compared with those taking carbamazepine or valproate. Patients receiving carbamazepine had higher levels of bone‐specific alkaline phosphatase compared with controls and those receiving valproate. Serum bicarbonate concentrations were significantly lower in patients receiving topiramate than in the other groups. Significance: Our results demonstrate that use of topiramate is associated with lower parathyroid hormone and bicarbonate concentrations along with mild hypocalcemia and increased bone turnover, which suggests that topiramate may have long‐term effects on bone.     

Differentiating between aphasic and nonaphasic stroke patients using semantic verbal fluency measures with administration time of 30 seconds

Administration time of 1 min for semantic verbal fluency measures can be overly long and therefore bothersome for aphasic patients because they can often retrieve only a few items after a certain period of time. The purpose of this study was to determine whether an administration time of 30 s would be more efficient in differentiating among aphasics, nonaphasic stroke patients, and normal controls. The subjects were 53 stroke patients and 28 normal controls. They had to generate as many animal names as they could within a given time. The number of animal names is gradually diminished in three groups (p < 0.001) in each time frame, that is, during the entire 60 s, the initial 30 s, and the following 30 s. The reaction time (RT) measure indicated that the RT of the aphasic patients was significantly increased compared to those of the other two groups (p < 0.001). The most optimal cutoff scores that differentiated each group are presented. These results suggest that an administration time of 30 s has discriminative validity to differentiate between the two patient groups. This shorter administration time could make the test more efficient by reducing the burden on both examiners and aphasic patients.     

Protein L-isoaspartyl O-methyltransferase inhibits amyloid beta fibrillogenesis in vitro

Fibrillar aggregates of beta-amyloid peptide (Abeta) are major constituents of the senile plaques found in the brains of patients suffering from Alzheimer's disease (AD). Previous studies have shown that spontaneous isomerization or racemization of aspartyl residues in Abeta peptides leads to conformational changes in the secondary structure and increased aggregative ability of the peptides. Protein L-isoaspartyl O-methyltransferase (PIMT, EC 2.1.1.77) is a repairing enzyme converting L-isoaspartyl/D-aspartyl residues in damaged proteins to normal L-aspartyl residues. In this study it was investigated, whether PIMT is able to modulate Abeta fibrillogenesis in vitro by methylation of isoaspartyl residue using purified 5Abeta and PIMT. A Thioflavin-T (Th-T) binding assay conducted after aging Abeta in vitro (37 degrees C, pH 7.4 in PBS) revealed that PIMT inhibited the increase of fluorescence caused by amyloid fibrillogenesis. Western blot analysis revealed that high molecular Abeta aggregates (> 200 kDa) only occurred during Abeta incubation, while they were reduced in response to incubation with PIMT and AdoMet. Additionally, circular dichroism (CD) showed that the beta-sheet structure was increased in Abeta peptides in a time-dependent fashion, while PIMT suppressed the beta-sheet transition after 24 h. Finally, transmission electron microscopy (TEM) revealed that PIMT reduced the size of the Abeta aggregates and induced a different pathway, leading to the formation of amorphous structures. Taken together, these findings indicate that isoaspartyl methylation leads to partial blockade of fibrillogenesis of Abeta by inhibiting the beta transition in the Abeta peptide.     

Promotion of Bone Regeneration Using Bioinspired PLGA/MH/ECM Scaffold Combined with Bioactive PDRN

Current approaches of biomaterials for the repair of critical-sized bone defects still require immense effort to overcome numerous obstacles. The biodegradable polymer-based scaffolds have been required to expand further function for bone tissue engineering. Poly(lactic-co-glycolic) acid (PLGA) is one of the most common biopolymers owing to its biodegradability for tissue regenerations. However, there are major clinical challenges that the byproducts of the PLGA cause an acidic environment of implanting site. The critical processes in bone repair are osteogenesis, angiogenesis, and inhibition of excessive osteoclastogenesis. In this study, the porous PLGA (P) scaffold was combined with magnesium hydroxide (MH, M) and bone-extracellular matrix (bECM, E) to improve anti-inflammatory ability and osteoconductivity. Additionally, the bioactive polydeoxyribonucleotide (PDRN, P) was additionally incorporated in the existing PME scaffold. The prepared PMEP scaffold has pro-osteogenic and pro-angiogenic effects and inhibition of osteoclast due to the PDRN, which interacts with the adenosine A_2A receptor agonist that up-regulates expression of vascular endothelial growth factor (VEGF) and down-regulates inflammatory cytokines. The PMEP scaffold has superior biological properties for human bone-marrow mesenchymal stem cells (hBMSCs) adhesion, proliferation, and osteogenic differentiation in vitro. Moreover, the gene expressions related to osteogenesis and angiogenesis of hBMSCs increased and the inflammatory factors decreased on the PMEP scaffold. In conclusion, it provides a promising strategy and clinical potential candidate for bone tissue regeneration and repairing bone defects.