Effect of proteinuria at relapse on shear wave velocity assessed using ultrasound elastography in children with idiopathic nephrotic syndrome.

PURPOSE: Shear wave velocity (SWV) is an ultrasound elastography technique that provides much information for kidney disease assessment. However, the factors that alter SWV are not fully understood; it is unclear whether the variation in SWV seen in proteinuria associated with disease progression is due to tissue or proteinuria. This study investigated the effect of proteinuria on SWV. METHODS: This prospective observational study compared SWV at remission with SWV at relapse in children treated for idiopathic nephrotic syndrome (INS) between April 2020 and December 2023. All relapses without oral steroids during the observation period were measured. SWV at remission was defined as the date closest to relapse during which repeated measurements were taken approximately every 3 months after steroid discontinuation. RESULTS: Eight patients were treated for INS with a median observation period of 21.9 months (11.8-27.1). Of the 15 relapses, five that met the definition were considered for the study. The median interval between the measurement at relapse and remission was 40 days (11-55). SWV was significantly lower at relapse than remission (2.40 ± 0.20 m/s vs. 2.14 ± 0.15 m/s, P < 0.01). CONCLUSIONS: SWV decreased in the presence of severe proteinuria at relapse compared to the remission measurements. Although more cases need to be studied, the decrease in SWV may reflect the mechanism by which protein leaks into the urine, not just a direct change caused by the presence of proteinuria.

Inhibition of cysteine protease disturbs the topological relationship between bone resorption and formation in vitro.

INTRODUCTION: Osteoporosis is a global health issue. Bisphosphonates that are commonly used to treat osteoporosis suppress both bone resorption and subsequent bone formation. Inhibition of cathepsin K, a cysteine proteinase secreted by osteoclasts, was reported to suppress bone resorption while preserving or increasing bone formation. Analyses of the different effects of antiresorptive reagents such as bisphosphonates and cysteine proteinase inhibitors will contribute to the understanding of the mechanisms underlying bone remodeling. MATERIALS AND METHODS: Our team has developed an in vitro system in which bone remodeling can be temporally observed at the cellular level by 2-photon microscopy. We used this system in the present study to examine the effects of the cysteine proteinase inhibitor E-64 and those of zoledronic acid on bone remodeling. RESULTS: In the control group, the amount of the reduction and the increase in the matrix were correlated in each region of interest, indicating the topological and quantitative coordination of bone resorption and formation. Parameters for osteoblasts, osteoclasts, and matrix resorption/formation were also correlated. E-64 disrupted the correlation between resorption and formation by potentially inhibiting the emergence of spherical osteoblasts, which are speculated to be reversal cells in the resorption sites. CONCLUSION: These new findings help clarify coupling mechanisms and will contribute to the development of new drugs for osteoporosis.

USP8 prevents aberrant NF-κB and Nrf2 activation by counteracting ubiquitin signals from endosomes.

K63-linked ubiquitin chains attached to plasma membrane proteins serve as tags for endocytosis and endosome-to-lysosome sorting. USP8 is an essential deubiquitinase for the maintenance of endosomal functions. Prolonged depletion of USP8 leads to cell death, but the major effects on cellular signaling pathways are poorly understood. Here, we show that USP8 depletion causes aberrant accumulation of K63-linked ubiquitin chains on endosomes and induces immune and stress responses. Upon USP8 depletion, two different decoders for K63-linked ubiquitin chains, TAB2/3 and p62, were recruited to endosomes and activated the TAK1-NF-κB and Keap1-Nrf2 pathways, respectively. Oxidative stress, an environmental stimulus that potentially suppresses USP8 activity, induced accumulation of K63-linked ubiquitin chains on endosomes, recruitment of TAB2, and expression of the inflammatory cytokine. The results demonstrate that USP8 is a gatekeeper of misdirected ubiquitin signals and inhibits immune and stress response pathways by removing K63-linked ubiquitin chains from endosomes.

Pathological Factors Affecting the R2* Values of the Kidney in Blood Oxygenation Level-dependent MR Imaging: A Retrospective Study.

PURPOSE: Despite the usefulness of blood oxygenation level-dependent (BOLD) MRI in assessing glomerulonephritis activity, its relationship with histological findings remains unclear. Because glomerulonephritis presents multiple complex injury patterns, analysis of each pattern is essential. We aimed to elucidate the relationship between the histological findings of the kidney and BOLD MRI findings in mesangial proliferative glomerulonephritis. METHODS: Children under 16 years of age diagnosed with mesangial proliferative glomerulonephritis by kidney biopsy at our university hospital between January 2013 and September 2022 were included in this study. Cortical and medullary spin relaxation rate (R2*) values were measured using BOLD MRI at 3T within two weeks before and after the kidney biopsy. The R2* values, including the fluctuations with low-dose oxygen administration, were retrospectively examined in relation to the cortical (mesangial proliferation, endothelial cell proliferation, crescent, sclerosis, and fibrosis) and medullary findings (fibrosis). RESULTS: Sixteen times kidney biopsies were performed for glomerulonephritis during the study period, and one patient was excluded because of comorbidities; the remaining 14 patients included six boys with a mean age of 11.9 ± 3.5 years at the BOLD examination. None of the patients had medullary fibrosis. Among the kidney tissue parameters, only sclerosis showed a significant correlation with R2* values: medulla with R2* values under atmospheric pressure (r = 0.53, P < 0.05) and cortex with the rate of change in R2* values with low-dose oxygen administration (r = -0.57, P < 0.03). In the multiple regression analysis, only sclerosis was an independent contributor to the change in R2* values with oxygen administration in the cortex (regression coefficient -0.109, P < 0.05). CONCLUSION: Since the R2* values reflect histological changes in the kidney, BOLD MRI may facilitate the evaluation of mesangial proliferative glomerulonephritis, potentially reducing the patient burden.

A Case of Shear Wave Velocity Reflecting the Disease Activity in Glomerulonephritis.

Ultrasound elastography can measure tissue elasticity using the shear wave velocity (SWV). Evaluating disease activity with elastography instead of renal biopsy may be less invasive. However, to the best of our knowledge, although there are studies comparing different glomerular diseases using SWV, there are no reports that have measured glomerulonephritis longitudinally from the acute phase of the disease. This study aimed to assess whether SWV reflects disease activity in glomerulonephritis, and we continued to observe children with post-streptococcal acute glomerulonephritis (PSAGN) from the acute phase to over a year later. In this case, a 6-year-old boy diagnosed with PSAGN had impaired renal function, and was admitted and tested. He was placed in a prone resting position and measurements were taken from the back. SWV was measured ≥50 times at each examination, and the mean was calculated when the net amount of effective SWV was ≥50%. The tests were performed once in the acute phase and thrice during the recovery phase for 13 months. SWV was found to be significantly lower in the recovery period than during the disease onset, and continued to stay lower at each test during the recovery period (P < 0.02). In conclusion, this indicated that SWV fluctuated similarly to the disease activity of glomerulonephritis; therefore, we suggest using SWV measurement to estimate the disease activity in glomerulonephritis in children. Although more clinical cases are needed, SWV measurement is a noninvasive and reproducible imaging modality to estimate the disease activity in glomerulonephritis.

Glomeruli Count and Arterial Injury in Real-Time Ultrasound-Guided Needle Kidney Biopsy Specimens: Adequacy of Three Approaches for Pig Kidneys.

INTRODUCTION: Real-time ultrasound-guided percutaneous kidney biopsy is essential for diagnosis and treatment planning; nonetheless, the optimal puncture approach has yet to be established. In vivo, performing different approaches on the same patient at once is not possible. This study aimed to determine the impact of different approaches on the number of obtained glomeruli and their potential to cause arterial injury using pig kidneys, which are similar to humans. METHODS: A total of 120 pig kidneys (60 right-sided kidneys and 60 left-sided kidneys) for research were obtained from a slaughterhouse. The specimens were collected from the lower pole on the sagittal plane of the kidney using three different approaches on the same kidney: caudocranial approach, caudal to cranial; craniocaudal approach, cranial to caudal; and vertical approach, through the surface cortex. Five blinded pediatric nephrologists assessed the number of glomeruli and arterial injuries. RESULTS: Overall, 360 specimens were collected from the kidneys through biopsy using a 16-gauge needle (mean vertical kidney length, 11.2 ± 0.7 cm; mean depth, 3.47 ± 0.23 cm). No significant difference in the incidence of arterial injury was observed between the three approaches (caudocranial vs. craniocaudal vs. vertical approaches: 78% vs. 87% vs. 87%, p = 0.14). In contrast, the vertical approach retrieved significantly more glomeruli than the caudocranial and craniocaudal approaches (caudocranial approach: 7.5 ± 2.8, craniocaudal approach: 7.8 ± 2.7, and vertical approach: 8.9 ± 3.3, p < 0.001). CONCLUSIONS: Considering its efficacy and safety profile, the vertical approach may be preferred, as more glomeruli can be obtained without increasing the incidence of arterial injury. Although the results cannot be directly extrapolated to humans due to the differences between species, they still offer important insights into the characteristics of each approach.

Effects of diurnal variation of bile acids by meal on cyclosporine A absorption.

BACKGROUND: Stabilizing blood levels with microemulsified cyclosporine A (CsA), administered in many pediatric kidney diseases, is important for effective immunosuppression and reduced nephrotoxicity. CsA is affected by total bile acids (TBAs); however, no reports have simultaneously measured both. We aimed to elucidate the hypothesized relationship between TBA levels and diurnal variation in CsA in children. METHODS: We retrospectively reviewed the medical records of children who were taking oral CsA for the treatment of kidney diseases between January 2016 and July 2021. They consumed four balanced meals and snacks during the day. CsA and TBA were measured twice, in pairs, before and at 0.5, 1, 1.5, 2, 3, and 4 h after oral administration in the morning and evening, and the four-h area under curve (AUC)0-4 of CsA and trough-to-peak ratio (TPR) of TBA were compared. RESULTS: Fifty-eight pairs were measured in total; 12 children had idiopathic nephrotic syndrome and 4 children had immunoglobulin A vasculitis with nephritis. The median age at measurement was 7.5 years and the dose of CsA was 3.8 mg/kg/day. The AUC0-4 (ng·h/mL) was significantly lower in the evening than in the morning (1,669 vs. 1,451, P < 0.001). The TPR of TBA was significantly higher in the evening than in the morning (0.14 vs. 0.25, P < 0.001). CONCLUSIONS: The low AUC0-4 and slow TBA secretion observed in the evening may be due to pediatric-specific dietary rhythms; thus, snack timing should be considered in children for stabilizing CsA levels.

Fluctuation of R2* values in blood oxygenation level-dependent MRI during acute and remission phases of IgA vasculitis with nephritis in children.

PURPOSE: Noninvasive assessment of the kidney using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) has progressed remarkably; indications have expanded to include the evaluation of glomerulonephritis. However, no longitudinal measurements from acute to post-treatment remission phases have been reported. Hence, this study aimed to investigate spin relaxation rate (R2*) values during acute and remission phases in children with glomerulonephritis. MATERIALS AND METHODS: All pediatric patients with IgA vasculitis with nephritis (IgAVN) diagnosed between January 2014 and October 2021 and requiring renal biopsy were retrospectively reviewed; four patients who were observed from onset to remission were included in this study. In total, eight MRIs were performed in the acute and remission phases, and R2* values and fluctuations induced by low-dose oxygen administration were determined from 10 echoes using a 1.5 T MRI system with 4.76-47.6 ms echo times and a 153 ms repetition time. RESULTS: The median age of patients undergoing MRI was 8.5 years in the acute phase and 13.9 years in the remission phase. R2* values of the acute phase were higher than those of the remission phase; however, the difference was not significant (cortex; p = 0.32 and medulla; p = 0.052). Oxygen administration did not cause fluctuations in the R2* values in the cortex or medulla during the acute phase (cortex; p = 0.67 and medulla; p = 0.76); however, in the remission phase, the R2* values in the cortex and medulla significantly decreased due to low-dose oxygen administration (cortex; p < 0.01 and medulla; p < 0.01). CONCLUSION: The fluctuation in R2* values observed during different phases of IgAVN indicates that BOLD MRI may be used to assess disease activity. Therefore, we propose BOLD MRI with low-dose oxygen administration as a noninvasive method to evaluate the activity of glomerulonephritis.

Cyclosporine A C1.5 monitoring reflects the area under the curve in children with nephrotic syndrome: a single-center experience.

BACKGROUND: The currently used single-monitoring method for drug-blood-level evaluation in cyclosporine A (CsA) treatment for nephrotic syndrome (NS) was established through hourly measurements based on adult organ transplantation. However, the pharmacokinetics may differ due to different concomitant medications, age, and conditions. This study was conducted to determine the measurement timing that best reflects the CsA area under the curve (AUC) in pediatric NS. METHODS: This retrospective study included children aged 2-14 years who were started on CsA treatment for idiopathic NS during 2013-2020. AUC0-4 was calculated from 7 points, before and 0.5, 1, 1.5, 2, 3, and 4 h after administration. Mean values at each timing were compared with age-dependent different drug forms. Correlation between AUC0-4 and measurement timing was analyzed. RESULTS: There were 13 patients (11 boys) whose median age during testing was 7.3 years, and the total number of measurements was 94. The highest timing of CsA concentrations was found in C1 59.6%. The content liquid used at younger ages had a faster absorption time to peak value and lower blood concentration than those of capsules. Among the significant correlations observed, AUC0-4 and C1.5 showed the strongest significant correlation coefficient (r = 0.93, P < 0.001). CONCLUSION: In pediatric NS, CsA metabolism may be faster than that in previous organ transplantation. Compared with C2, C1.5 monitoring may result in better disease control as it can best reflect the AUC0-4 and peak values associated with side effects, which are indicators of therapeutic efficacy.

Impaired Consciousness in a Coronavirus Disease 2019 Patient Caused by Low Serum Sodium: A Case Report.

A 30 year-old man with a high fever (37.5°C-40°C), vomiting, slurred speech, and mild cognitive impairment was admitted to our Emergency Department. He had traveled from Spain to the UK on business at the end of February 2020. A nasopharyngeal swab was positive by RT-PCR for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but a cerebrospinal fluid (CSF) sample was negative. His neurological abnormalities recovered completely on saline infusion to normalize his low serum sodium level. Although neurological abnormalities in patients with COVID-19 are rare, it is important to distinguish the etiologies including encephalitis, meningitis, or merely electrolyte abnormalities.

Dopaminergic restoration of prefrontal cortico-putaminal network in gene therapy for aromatic l-amino acid decarboxylase deficiency.

Aromatic l-amino acid decarboxylase (AADC) is an essential dopamine-synthesizing enzyme. In children with AADC deficiency, the gene delivery of AADC into the putamen, which functionally interacts with cortical regions, was found to improve motor function and ameliorate dystonia. However, how the restoration of dopamine in the putamen in association with cortico-putaminal networks leads to therapeutic effects remains unclear. Here, we examined neuroimaging data of eight patients with AADC deficiency (five males and three females, age range 4-19 years) who received the AADC gene therapy of the bilateral putamen in an open-label phase 1/2 study. Using high-resolution positron emission tomography with a specific AADC tracer, 6-[18F]fluoro-l-m-tyrosine (FMT), we showed that FMT uptake increased in the broad area of the putamen over the years. Then, with the structural connectivity-based parcellation of the putaminal area, we found that motor improvement is associated with dopaminergic restoration of the putaminal area that belongs to the prefrontal cortico-putaminal network. The prefrontal area dominantly belongs to the frontoparietal control network, which contributes to cognitive-motor control function, including motor initiation and planning. The results suggest that putaminal dopamine promotes the development of an immature motor control system, particularly in the human prefrontal cortex that is primarily affected by AADC deficiency.

Effects of low-dose oxygen administration on renal blood oxygenation level-dependent MRI in children with glomerulonephritis.

OBJECTIVE: Children are often sedated for renal blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) and may require low-dose oxygen administration. It is unclear whether low-dose oxygen administration affects results of BOLD MRI. We investigated the effect of low-dose oxygen administration on renal BOLD MRI and its variation by the presence or absence of renal disease. MATERIALS AND METHODS: We retrospectively examined children undergoing MRI for renal disease between 2013 and 2020. Patients were divided into glomerulonephritis and non-glomerulonephritis groups; spin relaxation time (T2*) was determined using a 3.0 T MRI system. RESULTS: The study included 10 children (5 patients in each group); patient characteristics between the groups did not differ significantly. In the entire cohort, oxygen administration reduced mean spin relaxation rate (R2*) value in the medulla (p < 0.04). The mean R2* value decreased with oxygen administration in the non-glomerulonephritis group, whereas this was not observed in the glomerulonephritis group. The responses to oxygen administration of the two groups differed significantly in the cortex (p < 0.05) and medulla (p < 0.02). DISCUSSION: Low-dose oxygen administration affects the results of BOLD MRI. We suggest that understanding the fluctuations due to oxygen administration is useful in monitoring the disease activity of glomerulonephritis.

Improvement of driver active interventions during automated driving by displaying trajectory pointers-A driving simulator study.

Objective: The handover of vehicle control from automated to manual operation is a critical aspect of interaction between drivers and automated driving systems (ADS). In some cases, it is possible that the ADS may fail to detect an object. In this event, the driver must be aware of the situation and resume control of the vehicle without assistance from the system. Consequently, the driver must fulfill the following 2 main roles while driving: (1) monitor the vehicle trajectory and surrounding traffic environment and (2) actively take over vehicle control if the driver identifies a potential issue along the trajectory. An effective human-machine interface (HMI) is required that enables the driver to fulfill these roles. This article proposes an HMI that constantly indicates the future position of the vehicle. Methods: This research used the Toyota Dynamic Driving Simulator to evaluate the effect of the proposed HMI and compares the proposed HMI with an HMI that notifies the driver when the vehicle trajectory changes. A total of 48 test subjects were divided into 2 groups of 24: One group used the HMI that constantly indicated the future position of the vehicle and the other group used the HMI that provided information when the vehicle trajectory changed. The following instructions were given to the test subjects: (1) to not hold the steering wheel and to allow the vehicle to drive itself, (2) to constantly monitor the surrounding traffic environment because the functions of the ADS are limited, and (3) to take over driving if necessary. The driving simulator experiments were composed of an initial 10-min acclimatization period and a 10-min evaluation period. Approximately 10 min after the start of the evaluation period, a scenario occurred in which the ADS failed to detect an object on the vehicle trajectory, potentially resulting in a collision if the driver did not actively take over control and manually avoid the object. Results: The collision avoidance rate of the HMI that constantly indicated the future position of the vehicle was higher than that of the HMI that notified the driver of trajectory changes, χ2 = 6.38, P < .05. The steering wheel hands-on and steering override timings were also faster with the proposed HMI (t test; P < .05). Conclusions: This research confirmed that constantly indicating the position of the vehicle several seconds in the future facilitates active driver intervention when an ADS is in operation.

Gene therapy improves motor and mental function of aromatic l-amino acid decarboxylase deficiency.

In patients with aromatic l-amino acid decarboxylase (AADC) deficiency, a decrease in catecholamines and serotonin levels in the brain leads to developmental delay and movement disorders. The beneficial effects of gene therapy in patients from 1 to 8 years of age with homogeneous severity of disease have been reported from Taiwan. We conducted an open-label phase 1/2 study of population including adolescent patients with different degrees of severity. Six patients were enrolled: four males (ages 4, 10, 15 and 19 years) and one female (age 12 years) with a severe phenotype who were not capable of voluntary movement or speech, and one female (age 5 years) with a moderate phenotype who could walk with support. The patients received a total of 2 × 1011 vector genomes of adeno-associated virus vector harbouring DDC via bilateral intraputaminal infusions. At up to 2 years after gene therapy, the motor function was remarkably improved in all patients. Three patients with the severe phenotype were able to stand with support, and one patient could walk with a walker, while the patient with the moderate phenotype could run and ride a bicycle. This moderate-phenotype patient also showed improvement in her mental function, being able to converse fluently and perform simple arithmetic. Dystonia disappeared and oculogyric crisis was markedly decreased in all patients. The patients exhibited transient choreic dyskinesia for a couple of months, but no adverse events caused by vector were observed. PET with 6-[18F]fluoro-l-m-tyrosine, a specific tracer for AADC, showed a persistently increased uptake in the broad areas of the putamen. In our study, older patients (>8 years of age) also showed improvement, although treatment was more effective in younger patients. The genetic background of our patients was heterogeneous, and some patients suspected of having remnant enzyme activity showed better improvement than the Taiwanese patients. In addition to the alleviation of motor symptoms, the cognitive and verbal functions were improved in a patient with the moderate phenotype. The restoration of dopamine synthesis in the putamen via gene transfer provides transformative medical benefit across all patient ages, genotypes, and disease severities included in this study, with the most pronounced improvements noted in moderate patients.10.1093/brain/awy331_video1awy331media15991361892001.

Subacute autonomic and sensory neuropathy closely related to cytomegalovirus infection preceded by frequent syncopal attacks.

A 73-year-old woman who had hypertension developed a slight fever and general malaise with laboratory-proven hepatic dysfunction as well as frequent syncopal attacks 3 months before admission to our hospital. One month later, she developed urinary retention and distal limb numbness. Upon admission, her neurological examination showed reduced limb tendon reflexes, glove and stocking-type numbness, and diminished senses of touch, temperature, pain, and distal leg vibration and position. Serum cytomegalovirus (CMV) IgM antibody and CMV IgG antibody were elevated on admission, and both decreased thereafter, confirming CMV infection. No serum anti-ganglioside antibody was detected. Cerebrospinal fluid revealed a mild pleocytosis and elevated proteins. Compound muscle action potential (CMAP) amplitudes of the tibial and peroneal nerve were slightly reduced. Sensory nerve action potential (SNAP) amplitudes of the median and ulnar nerves were reduced, and sural SNAP was not evoked. Systolic blood pressure dropped 48 mmHg when the patient assumed a standing position from a supine one, demonstrating orthostatic hypotension, and a cold pressor test was abnormal, both indicating an obvious hypofunction of the sympathetic nerve. The postganglionic autonomic nerve appeared to be damaged because the accumulation of [(123)I] meta-iodobenzylguanidine was reduced on myocardial scintigraphy. These findings combined together led us to make a diagnosis of subacute autonomic and sensory neuropathy associated with CMV infection in this case. Following an eventless administration of oral fludrocortisones, intravenous immuno-globulin (IVIg) was given after one month of the hospitalization with a remarkable reduction of the syncope. This case is instructive in two points. One is that there may be a couple of months with syncope alone before the sensory disturbance appearance, and the other is that IVIg may be considerably effective for the patient-annoying syncopes. To our knowledge, this is the first report of subacute autonomic and sensory neuropathy caused by CMV infection.

Freezing of Gait in Parkinson's Disease Is Associated with Reduced 6-[(18)F]Fluoro-l-m-tyrosine Uptake in the Locus Coeruleus.

Freezing of gait (FOG) is a common disorder in Parkinson's disease (PD) and could be attributed to a reduction in brain noradrenaline. The aim of this study was to determine the relationship between aromatic l-amino acid decarboxylase (AADC) activity in the locus coeruleus (LC) and FOG in PD using high-resolution positron emission tomography with an AADC tracer, 6-[(18)F]fluoro-l-m-tyrosine (FMT). We assessed 40 patients with PD and 11 age-matched healthy individuals. PD was diagnosed based on the UK Brain Bank criteria by two movement disorder experts. FOG was directly observed by the clinician and assessed using a patient questionnaire. FMT uptake in the LC, caudate, and putamen was analyzed using PMOD software on coregistered magnetic resonance images. FOG was present in 30 patients. The severity of FOG correlated with the decrease of FMT uptake in the LC regardless of disease duration and the severity of other motor impairments, indicating dysfunction of the noradrenergic network in FOG.

Measurement of vancomycin hydrochloride concentration in the exudate from wounds receiving negative pressure wound therapy: a pilot study.

It has been reported that negative pressure wound therapy (NPWT) is effective in the treatment of contaminated wounds. We hypothesised that systemically administered antibiotics migrate to wound site effectively by NPWT, which provides the antibacterial effect. We measured and compared the concentrations of vancomycin in the exudate and blood serum. Eight patients with skin ulcers or skin defect wounds who were treated with NPWT and were administered an intravenous drip of vancomycin were enrolled in this study. The wound surfaces were muscle, muscle fascia or adipose tissue. We administered vancomycin intravenously to NPWT patients (1-3 g/day). The exudate was obtained using 500 ml V.A.C. ATS canisters without gel. Three days later, the concentrations of vancomycin were measured. The mean concentration of vancomycin in the exudate from NPWT was 67% of the serum vancomycin concentration. We found that concentrations of vancomycin in NPWT exudates are higher than the previously reported concentrations in soft tissue without NPWT. The proactive use of NPWT might be considered in cases of suspected wound contamination when a systemic antibiotic is administered.

Protective effects of polysialic acid on proteolytic cleavage of FGF2 and proBDNF/BDNF.

Polysialic acid (polySia) is a linear polymer of sialic acid that modifies neural cell adhesion molecule (NCAM) in the vertebrate brain. PolySia is a large and exclusive molecule that functions as a negative regulator of cell-cell interactions. Recently, we demonstrated that polySia can specifically bind fibroblast growth factor 2 (FGF2) and BDNF; however, the protective effects of polySia on the proteolytic cleavage of these proteins remain unknown, although heparin/heparan sulfate has been shown to impair the cleavage of FGF2 by trypsin. Here, we analyzed the protective effects of polySia on the proteolytic cleavage of FGF2 and proBDNF/BDNF. We found that polySia protected intact FGF2 from tryptic activity via the specific binding of extended polySia chains on NCAM to FGF2. Oligo/polySia also functioned to impair the processing of proBDNF by plasmin via binding of oligo/polySia chains on NCAM. In addition, the polySia structure synthesized by mutated polysialyltransferase, ST8SIA2/STX(SNP7), which was previously identified from a schizophrenia patient, was impaired for these functions compared with polySia produced by normal ST8SIA2. Taken together, these data suggest that the protective effects of polySia toward FGF2 and proBDNF may be involved in the regulation of the concentrations of these neurologically active molecules.