Expression and characterization of myristoylated preS1-conjugated nanocages for targeted cell delivery.

Lipid modification of proteins plays key roles in cellular signaling pathways. We describe the development of myristoylated preS1-nanocages (myr-preS1-nanocages) that specifically target human hepatocyte-like HepaRG cells in which a specific receptor-binding peptide (preS1) is joined to the surface of naturally occurring ferritin cages. Using a genetic engineering approach, the preS1 peptide was joined to the N-terminal regions of the ferritin cage via flexible linker moieties. Myristoylation of the preS1 peptide was achieved by co-expression with yeast N-myristoyltransferase-1 in the presence of myristic acid in Escherichia coli cells. The myristoylated preS1-nanocages exhibited significantly greater specificity for human hepatocyte-like HepaRG cells than the unmyristoylated preS1-nanocages. These results suggest that the lipid-modified nanocages have great potential for effective targeted delivery to specific cells.

A case of emphysematous cystitis caused by mechanical stimulation of pelvic fracture nonunion.

Emphysematous cystitis is a rare condition that develops due to tissue hyperglycemia and urinary tract infection by gas-producing bacteria. We report a case of emphysematous cystitis caused by mechanical stimulation of a pelvic fracture nonunion. An 80-year-old man was injured in a motorcycle accident and diagnosed with pelvic fracture. Seven days later, he had high fever and computed tomography (CT) revealed gas in the hematoma around the pelvic fracture and the abscess. Therefore, infection following the pelvic fracture was diagnosed. Despite multiple operations and antibiotics treatment, malformation and nonunion of the pelvis occurred. One month after starting weight bearing, emphysema of the bladder wall adjacent to the pubic fracture were found and spread throughout the bladder wall. With stopping of weight bearing, antibiotics treatment and a urinary catheter, emphysema disappeared after 2 months. It was considered that the pubic fracture fragment irritated the bladder wall due to weight bearing and emphysematous cystitis consequently developed.

Charlson comorbidity index is predictive of postoperative clinical outcome after single-level posterior lumbar interbody fusion surgery.

BACKGROUND: In several previous studies, Charlson comorbidity index (CCI) score was associated with postoperative complications, mortality, and re-admission. There are few reports about the influence of CCI score on postoperative clinical outcome. The purpose of this study was to investigate the influence of comorbidities as calculated with CCI on postoperative clinical outcomes after PLIF. METHODS: Three hundred sixty-six patients who underwent an elective primary single-level PLIF were included. Postoperative clinical outcome was evaluated with the Japanese Orthopaedic Association lumbar score (JOA score). The correlation coefficient between the CCI score and postoperative improvement in JOA score was investigated. Patients were divided into three groups according to their CCI score (0, 1, and 2+). JOA improvement rate, length of stay (LOS), and direct cost were compared between each group. Postoperative complications were also investigated. RESULTS: There was a weak negative relationship between CCI score and JOA improvement rate (r = - 0.20). LOS and direct cost had almost no correlation with CCI score. The JOA improvement rate of group 0 and group 1 was significantly higher than group 2+. LOS and direct cost were also significantly different between group 0 and group 2+. There were 14 postoperative complications. Adverse postoperative complications were equivalently distributed in each group, and not associated with the number of comorbidities. CONCLUSIONS: A higher CCI score leads to a poor postoperative outcome. The recovery rate of patients with two or more comorbidities was significantly higher than in patients without comorbidities. However, the CCI score did not influence LOS and increased direct costs. The surgeon must take into consideration the patient's comorbidities when planning a surgical intervention in order to achieve a good clinical outcome.

The effectiveness of preoperative assessment using a patient-specific three-dimensional pseudoarticulation model for minimally invasive posterior resection in a patient with Bertolotti's syndrome: a case report.

BACKGROUND: Bertolotti's syndrome is widely known to cause low back pain in young patients and must be considered as a differential diagnosis. Its treatment such as conservative therapy or surgery remains controversial. Surgical procedure is recommended for intractable low back pain. The three-dimensional (3D) lumbosacral transitional vertebrae anatomy should be completely understood for a successful surgery. Using an intraoperative 3D navigation and preoperative preliminary surgical planning with a patient-specific 3D plaster model contribute for safe surgery and good outcome. CASE PRESENTATION: A case of a 22-year-old Japanese male patient with intractable left low back pain due to lumbosacral transitional vertebrae with Bertolotti's syndrome. The symptom resisted the conservative treatment, and anesthetic injection at pseudoarticulation only provided a short-term pain relief. Posterior resection using intraoperative three-dimensional (3D) navigation has been performed through microendoscopic view. Pseudoarticulation was totally and successfully resected in a safe manner. CONCLUSIONS: Preoperative surgical planning and rehearsal using a patient-specific 3D plaster model was greatly useful and effective for surgeons in performing accurate and safe pseudoarticulation resection.

Relationship between Displacement of the Psoas Major Muscle and Spinal Alignment in Patients with Adult Spinal Deformity.

STUDY DESIGN: Cross sectional study. PURPOSE: To clarify the difference in position of the psoas muscle between adult spinal deformity (ASD) and lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: Although it is known that the psoas major muscle deviates in ASD patients, no report is available regarding the difference in comparison with LSS patients. METHODS: This study investigates 39 patients. For evaluating spinal alignment, pelvic tilt (PT), pelvic incidence (PI), sacral slope, lumbar lordosis (LL), PI-LL, Cobb angle, and the convex side, the lumbar curves were measured. For measuring the position of the psoas major at the L4/5 disk level, magnetic resonance imaging was used. The displacements of psoas major muscle were measured separately in the anterior-posterior and lateral directions. We examined the relationship between the radiographic parameters and anterior displacement (AD) and lateral displacement (LD) of the psoas major muscle. RESULTS: AD was demonstrated in 15 cases with ASD and nine cases with LSS (p>0.05). LD was observed in 13 cases with ASD and no cases with LSS (p<0.01). The Cobb angle was significantly greater in cases with AD than in those without AD (p=0.04). PT, LL, PI-LL, and Cobb angle were significantly greater in cases with LD (p<0.05). All cases with LD had AD, but no case without AD had LD (p<0.001). The side of greater displacement at L4/5 and the convex side of the lumbar curve were consistent in all cases. CONCLUSIONS: Despite AD being observed in LSS as well, LD was observed only in the ASD group. Radiographic parameters were worse when LD was seen, rather than AD.

An evaluation of anesthetic fade in motor evoked potential monitoring in spinal deformity surgeries.

BACKGROUND: Intraoperative neuromonitoring using motor evoked potentials (MEP) satisfactorily detects motor tract integrity changes during spinal surgery. However, monitoring is affected by "anesthetic fade," in which the stimulation threshold increases because the waveform amplitude decreases with the accumulation of propofol. Therefore, the purpose of this study was to clarify the effect of anesthetic fade on transcranial MEPs by investigating the time-dependent changes of amplitude during spinal deformity surgeries. METHODS: We retrospectively reviewed medical records of 142 spinal deformity patients (66 patients with idiopathic scoliosis, 28 with adult spinal deformities, 19 with neuromuscular scoliosis, 17 with syndromic scoliosis, and 12 with congenital scoliosis). The average age was 28 years (range, 5 to 81 years). MEPs were recorded bilaterally from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles during spinal deformity surgeries. The Wilcoxon signed-rank test was used to investigate the time-dependent changes of amplitude after propofol infusion to evaluate anesthetic fade effects. RESULTS: The average time to baseline from initial propofol infusion was 113 min (range, 45 to 182 min). In the ADM, the amplitude was 52% at 1 h after initial propofol infusion, 102% at 2 h, 105% at 3 h, 101% at 4 h, 86% at 5 h, and 81% at 6 h. Compared to the 2-h time point, MEP decreased significantly by 16% at 5 h (P < 0.0005) and by 21% at 6 h (P < 0.05). In the AH, the amplitude was 49% at 1 h after initial infusion of propofol, 102% at 2 h, 102% at 3 h, 92% at 4 h, 71% at 5 h, and 63% at 6 h. Compared to the 2-h time point, MEP decreased significantly by 10% at 4 h (P < 0.005), by 31% at 5 h (P < 0.0000005), and by 39% at 6 h (P < 0.05). CONCLUSIONS: MEP amplitude significantly decreased in the upper limbs at 5 and 6 h and in the lower limbs at 4, 5, and 6 h after the initial infusion of propofol, respectively. The influence of anesthetic fade could influence false positive MEPs during long spinal surgeries.