Citations

ABSTRACT Background Linkage analyses of families with primary familial brain calcification (formerly idiopathic basal ganglia calcification [IBGC]) identified 3 candidate loci (IBGC1‐3). Recently, SLC20A2 mutations were found in the IBGC1 and IBGC3 families, merging these 2 loci. We here elucidate the genetic cause of primary familial brain calcification in the ‘IBGC2’ kindred. Methods We sequenced known primary familial brain calcification genes and quantified SLC20A2 and PDGFB . Moreover, CT scans of affected and unaffected family members were evaluated by 2 blinded neuroradiologists for distribution of brain calcification. Results A heterozygous multiexonic SLC20A2 deletion was detected in several affected family members. A reevaluation of neuroimaging data revealed a subset of mutation‐negative individuals with only mild and/or unilateral calcification. Conclusions The identified SLC20A2 mutation resolves the genetic cause of primary familial brain calcification in the ‘IBGC2’ kindred, collapsing ‘IBGC2’ into IBGC1. We suggest an algorithm for predicting the chances of finding genetic mutations that has to be validated in further studies. Our study enhances criteria for the evaluation of neuroimaging data, contributing further to the much needed harmonization of diagnostic and research data collection in primary familial brain calcification. © 2016 International Parkinson and Movement Disorder Society.

Neurological complications of haemolytic uraemic syndrome (HUS) include altered states of consciousness, seizures, ischaemic stroke and encephalopathy. Adult-onset HUS is uncommon, and there is only a limited literature reporting neurological complications in this population. We report an adult with Shiga toxin-associated HUS complicated by focal-onset non-convulsive status epilepticus, who made a full neurological recovery.

Abstract Background: Adenomatous polyps are the most common precursor to colorectal cancer, the second leading cause of cancer-related death in the United States. We sought to learn more about early events of carcinogenesis by investigating shifts in the gut microbiota of patients with adenomas. Methods: We analyzed 16S rRNA gene sequences from the fecal microbiota of patients with adenomas (n = 233) and without (n = 547). Results: Multiple taxa were significantly more abundant in patients with adenomas, including Bilophila, Desulfovibrio, proinflammatory bacteria in the genus Mogibacterium, and multiple Bacteroidetes species. Patients without adenomas had greater abundances of Veillonella, Firmicutes (Order Clostridia), and Actinobacteria (family Bifidobacteriales). Our findings were consistent with previously reported shifts in the gut microbiota of colorectal cancer patients. Importantly, the altered adenoma profile is predicted to increase primary and secondary bile acid production, as well as starch, sucrose, lipid, and phenylpropanoid metabolism. Conclusions: These data hint that increased sugar, protein, and lipid metabolism along with increased bile acid production could promote a colonic environment that supports the growth of bile-tolerant microbes such as Bilophilia and Desulfovibrio. In turn, these microbes may produce genotoxic or inflammatory metabolites such as H2S and secondary bile acids, which could play a role in catalyzing adenoma development and eventually colorectal cancer. Impact: This study suggests a plausible biological mechanism to explain the links between shifts in the microbiota and colorectal cancer. This represents a first step toward resolving the complex interactions that shape the adenoma–carcinoma sequence of colorectal cancer and may facilitate personalized therapeutics focused on the microbiota. Cancer Epidemiol Biomarkers Prev; 26(1); 85–94. ©2016 AACR.

Objective: Symptomatic thumb carpometacarpal (CMC) joint osteoarthritis is common. Early data support selective strengthening of the first dorsal interosseous (FDI) and opponens pollicis (OP) muscles for conservative management with improvement in pain and functional outcomes scores. There are limited biomechanical studies to support such strengthening programs. The purpose of these studies was to quantify the kinematics and joint kinetics at the thumb CMC joint during simulated pinch with selective activation of the FDI and OP muscles. The first study was completed with all ligamentous attachments of the CMC joint intact. The second study was completed with all CMC ligaments released. Hypothesis: Our hypothesis was that increased loads in the FDI and OP result in effects to the joint kinematics and reduce subluxation. Results: Our results from both studies show the OP and FDI act synergistically to center the first metacarpal on the trapezium and reduce subluxation during simulated pinch. The OP is the predominant corrective force but tends to overcorrect if unopposed. The FDI tempers the action of OP and contributes to improved CMC congruency. Conclusion: Our conclusion is these biomechanical data support selective thenar muscle re-education and strengthening programs for conservative management of thumb CMC joint osteoarthritis and pain.

Objective: Vascularized toe joint transfer for finger proximal interphalangeal joint (PIPJ) reconstruction is a well-described technique in the literature. However, the reconstructed PIPJ is known to have issues with suboptimal range of motion and extension lag. One of the reasons for this problem is the length of the intercalated bony segment. There is a lack of evidence and consensus regarding the optimal length of the intercalated segment. This study hence was performed to determine the impact of the intercalated segment length on the subsequent passive arc of motion (AOM) and extension lag of the reconstructed PIPJ. Materials and Methods: We harvested the intercalated joint graft (the toe PIPJ along with its associated extensor tendons) from the lesser toes and transferred it to the finger of cadavers. A predetermined constant PIPJ defect size of 2 cm was created on the finger. By insetting 3 different lengths of the intercalated segment to the finger PIPJ, we investigated the effect of shortened (1.5 cm), exact (2.0 cm), or lengthened (2.5 cm) intercalated segment lengths on the AOM and extension lag of the reconstructed PIPJ. Results: The average AOM of finger PIPJ was 81.0° ± 19.1° and that of the toe PIPJ was 53.6° ± 16.1°. In the group with longer intercalated segment, the average AOM was 29.9° ± 10.5° with an extension lag of 32° ± 11.7°. In the group with equal intercalated segment length, the average AOM was 49.1° ± 11.5° with an extension lag of 15.4° ± 10.6°. In the group with shorter intercalated segment, the average AOM was 70.9° ± 12.6° with an extension lag of 8.4° ± 8.9°. Conclusions: From our study, shortening the intercalated segment may provide the most reduction in the extension lag of the reconstructed PIPJ. Future studies could involve further refinement of the amount of length to be shortened. This would probably lie between 0 to 5 mm.

Objective: The current gold standard treatment for peripheral nerve gaps remains the use of nerve autografts. Decellularized nerve allografts provide a potential ideal alternative, avoiding important disadvantages of the autograft such as donor site morbidity and the limited supply without the need for immunosuppressive therapy. In the ideal decellularized nerve allograft, all cellular debris is removed while maintaining the nerves’ ultrastructure. For the optimization of processing techniques for nerve allografts, it is essential to compare the effect of different processing techniques on a histological level. Although several studies describe some form of (subjective) histological scoring system, evaluation techniques are not uniform and nothing has been validated yet. A validated method that is simple and could easily be adopted by other groups would allow for a more standardized comparison of nerve decellularization techniques. Therefore, the aim of this study was to describe and validate an easy, fast, and inexpensive method to compare different nerve decellularization strategies on a histological level. Materials and Methods: Fifty rat sciatic nerve and 70 human nerve segments (35 sensory and 35 motor) were used for this study. Nerve segments were processed using 5 different processing techniques and compared with unprocessed nerve segments (control). Three different stainings were used to visualize general morphology and different components of the nerve tissue. Toluidine blue was used for visualization of myelin sheaths, hematoxylin-eosin (H&E) for general morphology, and laminin y-l for visualization of the basal lamina. All slides were scored by 4 independent observers who were blinded for the different processing techniques used. Each slide was given a score from 1 to 5 where 5 resembles a “perfect” structure similar to the native nerve and 1 resembles severe structural damage or absence of the component. To validate this scoring system, the agreement between the observers was calculated using the intraclass correlation coefficient (ICC). Results: The 4 different observers similarly scored the processed nerve segments. Significant differences between the processing groups could be identified. We found a good correlation between the different observers for the Toluidine Blue (ICC = .73, 95% confidence interval [CI], 0.66-0.79), H&E (ICC = .72, 95% CI, 0.64-0.78), and Laminin staining (ICC = .74, 95% CI, 0.67-0.80). Conclusion: This study demonstrates the validity of the scoring system to evaluate nerve tissue after different processing protocols. A good correlation was found for the scoring of the structural integrity (Toluidine Blue, H&E, and Laminin). This method is suitable to compare different processing techniques in vitro on the route to engineering the ideal nerve allograft. Use of this method by other groups will make it possible to compare results of different nerve processing studies. Using valid outcome measurements is essential when striving to create new innovative options for nerve reconstruction.

Objective: Successful repair of segmental peripheral nerve defects remains a clinical challenge. The current clinical gold standard for such injuries is to use an autologous nerve graft, but this creates donor site morbidity with loss of sensation and potential scarring. Processed nerve allografts have been used to bridge segmental nerve gaps experimentally and clinically. However, in large nerve defects, functional outcomes are not comparable with autograft reconstruction yet; the longer the nerve gap, the poorer the outcome. Nerve architecture and the extracellular matrix (ECM) are preserved after processing; however, all cellular material including Schwann cells and axons are removed. The addition of supporting cells has been proposed to improve the decellularized allograft. Adipose-Derived Mesenchymal Stem Cells (AMSC) can potentially provide the necessary support for nerve regeneration due to local production of essential growth factors. While the mechanisms underlying the neurotrophic potential of AMSC remains unknown, it is postulated that the remaining ECM still has biological activity that influences the AMSC and their differentiation. Therefore, the purpose of this study was to quantitate the changes in gene expression profiles of the cells and quantify the actual produced growth factors after seeding the allograft with AMSC in vitro. Method: A total of 35 human nerve allografts were decellularized and seeded with human AMSC. At each time point (1, 3, 14, 21, and 28 days), total RNA was extracted, reverse transcribed into complementary DNA (cDNA), and quantitative reverse transcription–polymerase chain reaction (qRT-PCR) was performed in combination with gene specific assays for genes essential for nerve regeneration including nerve growth factor (NGF), Brain-derived neurotrophic factor (BDNF), pleiotrophin vascular endothelial growth factor (PTN VEGF), and growth associated protein 43 (GAP43).Additional genes were analyzed to map AMSC characteristics including proliferation, apoptosis, myelinization, and ECM molecules. Production of growth factors was evaluated and quantified using enzyme-linked immunosorbent assay (ELISA). All samples were analyzed in triplicates and data were compared with AMSC cultured in media only. Results: Semiquantitative RT-PCR analysis showed that the interaction of the processed allograft and AMSC enhanced the expression of the neurotrophic factors NGF, BDNF, and GAP43. The expression of the angiogenic molecules, vascular endothelial growth factor A (VEGF-A) was also increased and remained significantly elevated at 28 days post seeding. Analysis of ECM-related gene expression showed that laminin subunit beta-2 (LAMB2), collagen type I alpha 1 (COL1A1), collagen type III alpha 1 (COL3A1), fibulin 1 (FBLN1), were significantly elevated until 21 days post seeding while after 28 days, these levels were normalized. Angiogenic factor cluster of differentiation 31 (CD31) and neurotrophic factor PTN expression were down regulated in the seeded cells. Quantitative results of the ELISA analysis are pending. We anticipate differences in growth factor levels released by the seeded allograft compared with the control expression levels. Conclusion: This study demonstrates that the remaining ECM of the decellularized nerve allograft has a stimulating effect on AMSC. Upon the seeding, secretion of neurotrophic and angiogenic factors were triggered; the cells cultured on the allograft showed enhanced levels of neurotrophic genes. This is hypothesized to be a consequence of specific cell-ECM interactions within the allograft. The combination of patient’s own easily accessible, abundant supply of stem cells harvested from adipose tissue and the readily available processed nerve allograft is potentially a promising method for individualized peripheral nerve repair.

Objective/Hypothesis: Processed nerve allografts provide a promising alternative to nerve autografts with the advantages of a readily available unlimited supply, no donor site morbidity, and without the need for immunosuppression. The nerve allografts currently available for clinical use do not provide satisfactory results. The processing technique was optimized to reduce the allografts immunogenicity and cellular debris while maintaining the ultrastructural properties. The aim of this study was to evaluate the functional recovery after reconstruction of a long nerve gap using the optimized nerve allograft in a rabbit model. To study the influence of storage techniques on functional recovery, processed nerve allografts were either cold or frozen stored. The nerve allografts were challenged to the gold standard, the nerve autograft. Materials and Methods: Nerve allografts were decellularized using our optimized protocol and stored at either 4°C or −80°C. In 36 New Zealand White rabbits, a 3-cm peroneal nerve gap was repaired with either a cold or frozen stored processed nerve allograft or a nerve autograft (control). Nerve recovery was longitudinally evaluated with ultrasound measurements performed prior to surgery and at 10, 16, and 24 weeks follow-up. Functional motor recovery was determined 24 weeks postoperatively using electrophysiology (compound muscle action potentials [CMAP]), isometric tetanic force (ITF), wet muscle weight (MW), and histomorphometry. Results: The longitudinal ultrasound measurements showed that the cold stored nerve allograft provides faster and earlier regeneration than the frozen stored nerve allograft. At 24 weeks, the cold stored allograft showed equal results compared with the autograft based on ultrasound measurements. Ultrasound furthermore showed significantly impaired recovery in the frozen stored allograft group compared with both the cold stored allograft and autograft ( P < .05). The functional outcome measurements, MV and ITF, both showed that the cold stored allograft proved to have a similar result compared with the autograft ( P > .05 for both MW and ITF, respectively). The frozen stored allograft, however, had a significantly inferior result to the autograft ( P < .05 for both MW and ITF). The CMAP and histomorphometry results showed no significant differences between all 3 groups. Conclusions: Nerve reconstruction with the cold stored optimized nerve allograft results in successful recovery of a long motor nerve defect in a rabbit model, statistically equivalent to the gold standard nerve autograft. Freeze storage of the processed allograft impairs the functional outcome.