Brain-Targeted Liposomes Loaded with Monoclonal Antibodies Reduce Alpha-Synuclein Aggregation and Improve Behavioral Symptoms in Parkinson's Disease.

Monoclonal antibodies (mAbs) hold promise in treating Parkinson's disease (PD), although poor delivery to the brain hinders their therapeutic application. In the current study, it is demonstrated that brain-targeted liposomes (BTL) enhance the delivery of mAbs across the blood-brain-barrier (BBB) and into neurons, thereby allowing the intracellular and extracellular treatment of the PD brain. BTL are decorated with transferrin to improve brain targeting through overexpressed transferrin-receptors on the BBB during PD. BTL are loaded with SynO4, a mAb that inhibits alpha-synuclein (AS) aggregation, a pathological hallmark of PD. It is shown that 100-nm BTL cross human BBB models intact and are taken up by primary neurons. Within neurons, SynO4 is released from the nanoparticles and bound to its target, thereby reducing AS aggregation, and enhancing neuronal viability. In vivo, intravenous BTL administration results in a sevenfold increase in mAbs in brain cells, decreasing AS aggregation and neuroinflammation. Treatment with BTL also improve behavioral motor function and learning ability in mice, with a favorable safety profile. Accordingly, targeted nanotechnologies offer a valuable platform for drug delivery to treat brain neurodegeneration.

Temporal changes in the physical and mechanical properties of beetle elytra during maturation.

Changes in physical properties of Tenebrio molitor and Tribolium castaneum elytra (hardened forewings) were studied to understand how the development of microstructure and chemical interactions determine cuticle mechanical properties. Analysis of these properties supports a model in which cuticular material is continuously secreted from epidermal cells to produce an extracellular matrix so that the outermost layers mature first. It is hypothesized that enzymatic crosslinking and pigmentation reactions along with dehydration help to stabilize the protein-chitin network within the initial layers of cuticle shortly after eclosion. Mature layers are proposed to bear most of the mechanical loads. The frequency dependence of the storage modulus and the tan δ values decreased during the beginning of maturation, reaching constant values after 48 h post-eclosion. A decrease of tan δ indicates an increase in crosslinking of the material. The water content declined from 75% to 31%, with a significant portion lost from within the open spaces between the dorsal and ventral cuticular layers. Dehydration had a less significant influence than protein crosslinking on the mechanical properties of the elytron during maturation. When Tribolium cuticular protein TcCP30 expression was decreased by RNAi, the tan δ and frequency dependence of E' of the elytron did not change during maturation. This indicates that TcCP30 plays a role in the crosslinking process of the beetle's exoskeleton. This study was inspired by previous work on biomimetic multicomponent materials and helps inform future work on creating robust lightweight materials derived from natural sources. STATEMENT OF SIGNIFICANCE: Examination of changes in the physical properties of the elytra (hardened forewings) of two beetle species advanced understanding of how the molecular interactions influence the mechanical properties of the elytra. Physical characterization, including dynamic mechanical analysis, determined that the outer portion of the elytra matured first, while epidermal cells continued to secrete reactive components until the entire structure reached maturation. RNA interference was used to identify the role of a key protein in the elytra. Suppression of its expression reduced the formation of crosslinked polymeric components in the elytra. Identifying the molecular interactions in the matrix of proteins and polysaccharides in the elytra together with their hierarchical architecture provides important design concepts in the development of biomimetic materials.

Effect of Steroid-Soaked Gelatin Sponge on Soft Tissue Swelling Following Anterior Cervical Discectomy and Fusion: A Radiographic Analysis.

STUDY DESIGN: Retrospective radiological review and analysis of 79 patients who underwent primary anterior cervical discectomy and fusion (ACDF) of 2 or 3 levels between 2011 and 2013. PURPOSE: This study aimed to determine the effect of the local placement of a steroid-soaked gelatin sponge after ACDF on prevertebral soft tissue swelling. OVERVIEW OF LITERATURE: Although ACDF has become a popular choice for cervical fusion, the surgical involvement of the delicate anatomy of the neck frequently results in tissue irritation and edema. Swelling of the prevertebral soft tissue may consequently lead to mild-to-severe complications, ranging from dysphonia to dyspnea. METHODS: Out of the 79 patients who underwent primary ACDF, 52 received a gelatin sponge soaked with 40 mg of Depo-Medrol placed adjacent to the operated cervical levels. Prevertebral soft tissue swelling was detected using postoperative lateral X-ray. The radiographic values were compared to those of 27 patients who did not receive the treatment. RESULTS: Soft tissue swelling was markedly decreased in patients who received the placement of the steroid-soaked gelatin sponge next to their fused levels after surgery compared with that in patients who did not receive it. No complications were documented with the use of steroids. CONCLUSIONS: The placement of a steroid-soaked gelatin sponge markedly reduces postoperative soft tissue swelling following 2- or 3-level primary ACDF.

Emergent reintubation following elective cervical surgery: A case series.

AIM: To review cases of emergent reintubation after cervical surgery. METHODS: Patients who were emergently intubated in the post-operative period following cervical surgery were identified. The patients' prospectively documented demographic parameters, medical history and clinical symptoms were ascertained. Pre-operative radiographs were examined for the extent of their pathology. The details of the operative procedure were discerned. RESULTS: Eight hundred and eighty patients received anterior- or combined anterior-posterior cervical surgery from 2008-2013. Nine patients (1.02%) required emergent reintubation. The interval between extubation to reintubation was 6.2 h [1-12]. Patients were kept intubated after reintubation for 2.3 d [2-3]. Seven patients displayed moderate postoperative edema. One patient was diagnosed with a compressive hematoma which was subsequently evacuated in the OR. Another patient was diagnosed with a pulmonary effusion and treated with diuretics. One patient received a late debridement for an infected hematoma. Six patients reported residual symptoms and three patients made a complete recovery. CONCLUSION: Respiratory compromise is a rare but potentially life threatening complication following cervical surgery. Patients at increased risk should be monitored closely for extended periods of time post-operatively. If the airway is restored adequately in a timely manner through emergent re-intubation, the outcome of the patients is generally favorable.

Lumbar Spine Surgery in Patients with Parkinson Disease.

BACKGROUND: Parkinson disease is the second most common neurodegenerative condition. The literature on patients with Parkinson disease and spine surgery is limited, but increased complications have been reported. METHODS: All patients with Parkinson disease undergoing lumbar spine surgery between 2002 and 2012 were identified. Patients' charts, radiographs, and outcome questionnaires were reviewed. Parkinson disease severity was assessed with use of the modified Hoehn and Yahr staging scale. Complications and subsequent surgeries were analyzed. Risk for reoperation was assessed. RESULTS: Ninety-six patients underwent lumbar spine surgery. The mean patient age was 63.0 years. The mean follow-up duration was 30.1 months. The Parkinson disease severity stage was <2 in thirteen patients, 2 in thirty patients, 2.5 in twenty-three patients, and ≥3 in thirty patients. The primary indication for surgery was spinal stenosis in seventy-two patients, spondylolisthesis in seventeen patients, and coronal and/or sagittal deformity in seven patients. There were nineteen early complications, including postoperative infections requiring surgical irrigation and debridement and long-term antibiotics in ten patients. The visual analog scale for back pain improved from 7.4 cm preoperatively to 1.8 cm postoperatively (p < 0.001). The visual analog scale for lower-limb pain improved from 7.7 cm preoperatively to 2.3 cm postoperatively (p < 0.001). The Oswestry Disability Index score dropped from 54.1 points to 17.7 points at the time of the latest follow-up (p < 0.001). The Short Form-12 Physical Component Summary score improved from 26.6 points preoperatively to 30.5 points postoperatively (p < 0.05). Twenty patients required revision surgery. Risks for further surgery included a Parkinson disease severity stage of ≥3 (p < 0.05), a history of diabetes mellitus, treatment for osteoporosis, and a combined anterior and posterior approach. CONCLUSIONS: Despite a higher rate of complications than in the general population, the overall outcome of spine surgery in patients with mild to moderate Parkinson disease is good, with improvement of spine-related pain. A larger prospective study is warranted.

Stem cells for spine surgery.

In the past few years, stem cells have become the focus of research by regenerative medicine professionals and tissue engineers. Embryonic stem cells, although capable of differentiating into cell lineages of all three germ layers, are limited in their utilization due to ethical issues. In contrast, the autologous harvest and subsequent transplantation of adult stem cells from bone marrow, adipose tissue or blood have been experimentally utilized in the treatment of a wide variety of diseases ranging from myocardial infarction to Alzheimer's disease. The physiologic consequences of stem cell transplantation and its impact on functional recovery have been studied in countless animal models and select clinical trials. Unfortunately, the bench to bedside translation of this research has been slow. Nonetheless, stem cell therapy has received the attention of spinal surgeons due to its potential benefits in the treatment of neural damage, muscle trauma, disk degeneration and its potential contribution to bone fusion.

Spinal subdural hematoma following lumbar decompressive surgery: a report of two cases.

Spinal subdural hematoma (SSDH) following spine surgery is an extremely rare condition, with only three cases being reported in the literature. Unintended durotomy has been associated with SSDH due to alterations of pressures in the dural compartments. The objective of the present report was to report two rare cases of acute SSDH developed after lumbar decompressive surgery. In one of the patients, the diagnosis of SSDH was followed by urgent hematoma evacuation via durotomy due to the patient's worsening neurological symptoms. In the second patient, the SSDH was treated conservatively due to the absence of severe or progressive motor or sensory deficits. In conclusion, emergency evacuation via durotomy is the treatment of choice for patients with SSDH and neurologic impairment. Conservative management may be indicated in selected cases with absent motor and sensory deficits.

Medical students' and interns' interest in orthopedic surgery: the gender factor.

OBJECTIVE: There is an extremely small proportion of female medical students choosing to specialize in orthopedic surgery. The aim of the study was to assess medical students' and interns' interests and perceptions of orthopedic surgery and explore why women are not interested in orthopedic surgery. SETTING: Questionnaires were distributed to final-year medical students and interns assessing their interests and perception of orthopedic surgery. PARTICIPANTS: Final-year medical students and interns. RESULTS: Responses were obtained from 317 students and 199 interns. Among the medical students, 15% were interested in orthopedic surgery, but only 2% were women. Both male and female students perceived orthopedics as an "action"-packed, procedure-based profession, providing instant gratification, time in the operating room, high income, and the option for private practice. Female medical students considered it boring. Among interns, 11% were interested in orthopedic surgery; however, only 2% were women. When compared with the interns who were not interested in orthopedic surgery, a greater number of the interns interested in orthopedic surgery rated time with family and a procedure-intensive profession as important. Female students and interns were also interested in other surgical fields. CONCLUSIONS: The increasing majority of women among medical students will reshape the future of physician workforce by dictating changes in workforce participation, working conditions, and intercollegial relationships. Orthopedic surgery will need to adapt to these realities.

The Utility of 3-Dimensional-Navigation in the Surgical Treatment of Children With Idiopathic Scoliosis.

STUDY DESIGN: Ambispective study of patients undergoing surgical correction of adolescent idiopathic scoliosis. OBJECTIVE: To evaluate the accuracy of screw placement using preoperative 3-dimensional (3D) computed tomography (CT)-based navigation with intraoperative fluoroscopic guidance compared with freehand placement. SUMMARY OF BACKGROUND DATA: Pedicle screws placed in deformed vertebrae have a high malposition rate. The use of navigation-based systems has increased placement accuracy. METHODS: Intraoperative registration of patient anatomy to preoperative 3D-CT was performed using anatomic landmarks. When registration accuracy was high (mean square error, <1.0 mm), screw tracts were drilled under navigation guidance; when the error was >1.0 mm, re-registration was performed. The researchers documented times for registration, navigation, and screw placement, and the number of passes. Results were compared with outcomes in cases operated on with freehand screw placement. RESULTS: A total of 62 patients were included (54 females and 8 males; mean age was 15.1 years [range, 12-18 years]). Mean deformity was 67° (range, 52° to 80°). Mean follow-up was 35 months (range, 42-19 months). In the navigation group, 710 pedicle screws were placed. Mean times were 55 seconds for tracker placement, 94.5 seconds per vertebra for patient registration, 131.1 seconds for screw tract formation on the concave side of the deformity, and 129.5 seconds on the convex side. Average total procedure time was 3.5 hours (range, 2-7 hours). Mean overall registration accuracy was 0.7 mm. Pedicle integrity was breached in 1.6% trajectories. In the freehand group, 470 pedicle screws were placed. Average time for screw placement was 135.2 seconds (p < .001 vs. navigation). Pedicle integrity was breached in 5.1% of trajectories (p < .0001 vs. navigation). No patient developed neurological or other complications. There was no destabilization of the instrumented spine during short- or long-term follow-up. CONCLUSIONS: Intraoperative optic fluoroscopic navigation based on anatomic landmark registration to preoperative 3D-CT spine images enables precise pedicle screw placement with only a minor increase in pedicle preparation time in patients with adolescent idiopathic scoliosis.

An unbiased assessment of the role of imprinted genes in an intergenerational model of developmental programming.

Environmental factors during early life are critical for the later metabolic health of the individual and of future progeny. In our obesogenic environment, it is of great socioeconomic importance to investigate the mechanisms that contribute to the risk of metabolic ill health. Imprinted genes, a class of functionally mono-allelic genes critical for early growth and metabolic axis development, have been proposed to be uniquely susceptible to environmental change. Furthermore, it has also been suggested that perturbation of the epigenetic reprogramming of imprinting control regions (ICRs) may play a role in phenotypic heritability following early life insults. Alternatively, the presence of multiple layers of epigenetic regulation may in fact protect imprinted genes from such perturbation. Unbiased investigation of these alternative hypotheses requires assessment of imprinted gene expression in the context of the response of the whole transcriptome to environmental assault. We therefore analyse the role of imprinted genes in multiple tissues in two affected generations of an established murine model of the developmental origins of health and disease using microarrays and quantitative RT-PCR. We demonstrate that, despite the functional mono-allelicism of imprinted genes and their unique mechanisms of epigenetic dosage control, imprinted genes as a class are neither more susceptible nor protected from expression perturbation induced by maternal undernutrition in either the F1 or the F2 generation compared to other genes. Nor do we find any evidence that the epigenetic reprogramming of ICRs in the germline is susceptible to nutritional restriction. However, we propose that those imprinted genes that are affected may play important roles in the foetal response to undernutrition and potentially its long-term sequelae. We suggest that recently described instances of dosage regulation by relaxation of imprinting are rare and likely to be highly regulated.

Response to Brosch et al.

We would like to respond to Brosch et al. regarding our manuscript "Expression of the Splicing Factor Gene SFRS10 Is Reduced in Human Obesity and Contributes to Enhanced Lipogenesis" (Pihlajamäki et al., 2011b). Brosch performed RT-PCR in liver samples from 13 lean and 34 obese individuals, finding no differences in SFRS10 or LPIN1 expression. We wish to address points raised by Brosch, including experimental strategy and analysis of human SFRS10 expression.

Expression of the splicing factor gene SFRS10 is reduced in human obesity and contributes to enhanced lipogenesis.

Alternative mRNA splicing provides transcript diversity and may contribute to human disease. We demonstrate that expression of several genes regulating RNA processing is decreased in both liver and skeletal muscle of obese humans. We evaluated a representative splicing factor, SFRS10, downregulated in both obese human liver and muscle and in high-fat-fed mice, and determined metabolic impact of reduced expression. SFRS10-specific siRNA induces lipogenesis and lipid accumulation in hepatocytes. Moreover, Sfrs10 heterozygous mice have increased hepatic lipogenic gene expression, VLDL secretion, and plasma triglycerides. We demonstrate that LPIN1, a key regulator of lipid metabolism, is a splicing target of SFRS10; reduced SFRS10 favors the lipogenic ß isoform of LPIN1. Importantly, LPIN1ß-specific siRNA abolished lipogenic effects of decreased SFRS10 expression. Together, our results indicate that reduced expression of SFRS10, as observed in tissues from obese humans, alters LPIN1 splicing, induces lipogenesis, and therefore contributes to metabolic phenotypes associated with obesity.

Increased SRF transcriptional activity in human and mouse skeletal muscle is a signature of insulin resistance.

Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human muscle biopsies from patients with T2D; normoglycemic but insulin-resistant subjects with a parental family history (FH(+)) of T2D; and family history-negative control individuals (FH(­)). Actin cytoskeleton genes regulated by serum response factor (SRF) and its coactivator megakaryoblastic leukemia 1 (MKL1) had increased expression in T2D and FH(+) groups. Furthermore, striated muscle activator of Rho signaling (STARS), an activator of SRF, was upregulated in T2D and FH(+) and was inversely correlated with insulin sensitivity. Skeletal muscle from insulin-resistant mice recapitulated this gene expression pattern and showed reduced G-actin and increased nuclear localization of MKL1, each of which regulates SRF activity. Overexpression of MKL1 or reduction in G-actin decreased insulin-stimulated Akt phosphorylation, whereas reduction of STARS expression increased insulin signaling and glucose uptake. Pharmacological SRF inhibition by CCG-1423 reduced nuclear MKL1 and improved glucose uptake and tolerance in insulin-resistant mice in vivo. Thus, SRF pathway alterations are linked to insulin resistance, may contribute to T2D pathogenesis, and could represent therapeutic targets.

Natural history of nonoperatively treated symptomatic rotator cuff tears in patients 60 years old or younger.

BACKGROUND: Rotator cuff tears are the most frequent tendon injury in the adult population. However, the natural history of nonoperatively treated full-thickness tears is poorly defined. Knowledge of the expected evolution in tear size is important when considering nonoperative versus surgical care, especially in relatively young, active patients. PURPOSE: To evaluate the size change of nonoperatively treated full-thickness rotator cuff tears over 2 to 3 years' follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors prospectively followed patients 60 years old or younger who had a full-thickness rotator cuff tear equal to or larger than 5 mm, as diagnosed by bilateral shoulder ultrasound, and who were treated nonoperatively. At 2 to 3 years after the index ultrasound examination, a repeat ultrasound examination was performed by the same ultrasonographer. Results of the follow-up ultrasound examinations of both shoulders were compared with those of the index ultrasound examinations for change in rotator cuff tear size. The correlations were examined between these changes and age, sex, history of initial trauma, size of tear on the index ultrasound, and current shoulder symptoms. RESULTS: Fifty-one patients with 61 rotator cuff tears were evaluated. At a follow-up of 25 to 39 months (mean, 29), 49% of the tears (30 tears) increased in size, 43% (26 tears) had not changed, and 8% (5 tears) decreased in size. For 25% (10 shoulders ) of initially intact shoulders (41 shoulders), a new full-thickness rotator cuff tear was diagnosed. No correlation was found between the change in tear size and age of the patient (P = .85), sex (P = .93), existence of a prior trauma (P = .63), size of tear at index ultrasound (P = .62), and bilateral tears (P = 1.00). There was a correlation between the existence of considerable pain at the time of the follow-up ultrasound and a clinically significant increase in tear size (P = .002). CONCLUSION: Full-thickness rotator cuff tears tend to increase in size in about half of patients aged 60 years or younger. Surgery should be initially considered in these patients to prevent a probable increase in size tear. Patients treated nonoperatively should be routinely monitored for tear size increase, especially if they remain symptomatic.

Thyroid hormone-related regulation of gene expression in human fatty liver.

CONTEXT: Fatty liver is an important complication of obesity; however, regulatory mechanisms mediating altered gene expression patterns have not been identified. OBJECTIVE: The aim of the study was to identify novel transcriptional changes in human liver that could contribute to hepatic lipid accumulation and associated insulin resistance, type 2 diabetes, and nonalcoholic steatohepatitis. DESIGN: We evaluated gene expression in surgical liver biopsies from 13 obese (nine with type 2 diabetes) and five control subjects using Affymetrix U133A microarrays. PCR validation was performed in liver biopsies using an additional 16 subjects. We also tested thyroid hormone responses in mice fed chow or high-fat diet. SETTING: Recruitment was performed in an academic medical center. PARTICIPANTS: Individuals undergoing elective surgery for obesity or gallstones participated in the study. RESULTS: The top-ranking gene set, down-regulated in obese subjects, was comprised of genes previously demonstrated to be positively regulated by T(3) in human skeletal muscle (n = 399; P < 0.001; false discovery rate = 0.07). This gene set included genes related to RNA metabolism (SNRPE, HNRPH3, TIA1, and SFRS2), protein catabolism (PSMA1, PSMD12, USP9X, IBE2B, USP16, and PCMT1), and energy metabolism (ATP5C1, COX7C, UQCRB). We verified thyroid hormone regulation of these genes in the liver after injection of C57BL/6J mice with T(3) (100 microg/100 g body weight); furthermore, T(3)-induced increases in expression of these genes were abolished by high-fat diet. In agreement, expression of these genes inversely correlated with liver fat content in humans. CONCLUSIONS: These data suggest that impaired thyroid hormone action may contribute to altered patterns of gene expression in fatty liver.

Two deltaC splice-variants have distinct signaling abilities during somitogenesis and midline patterning.

Notch signaling is required for many developmental processes, yet differences in the signaling abilities of various Notch ligands are poorly understood. Here, we have isolated a splice variant of the zebrafish Notch ligand deltaC in which the inclusion of the last intron leads to a truncation of the C-terminal 39 amino acids (deltaC(tv2)). We show that, unlike deltaC(tv1), deltaC(tv2) cannot function effectively in somitogenesis but has an enhanced ability to signal during midline development. Additionally, over-expression of deltaC(tv2) preferentially affects anterior midline development, while another Notch ligand, deltaD, shows a posterior bias. Using chimeric Deltas we show that the intracellular domain is responsible for the strength of signal in midline development, while the extracellular domain influences the anterior-posterior bias of the effect. Together our data show that different deltas can signal in biologically distinct ways in both midline formation and somitogenesis. Moreover, it illustrates the importance of cell-type-dependent modifiers of Notch signaling in providing ligand specificity.

Priming, initiation and synchronization of the segmentation clock by deltaD and deltaC.

Zebrafish somitogenesis is governed by a segmentation clock that generates oscillations in expression of several Notch pathway genes, including her1, her7 and deltaC. Using a combination of pharmacological inhibition and Mendelian genetics, we show that DeltaD and DeltaC, two Notch ligands, represent functionally distinct signals within the segmentation clock. Using high-resolution fluorescent in situ hybridization, the oscillations were divided into phases based on eight distinct subcellular patterns of mRNA localization for 140,000 cells. her1, her7 and deltaC expression was examined in wild-type, deltaD(-/-) and deltaC(-/-) embryos. We identified areas within the tailbud where the clock is set up in the progenitor cells (priming), where the clock starts running (initiation), and where the clocks of neighbouring cells are entrained (synchronization). We find that the clocks of motile cells are primed by deltaD in a progenitor zone in the posterior tailbud and that deltaD is required for cells to initiate oscillations on exiting this zone. Oscillations of adjacent cells are synchronized and amplified by deltaC in the posterior presomitic mesoderm as cell movement subsides and cells maintain stable neighbour relationships.

beamter/deltaC and the role of Notch ligands in the zebrafish somite segmentation, hindbrain neurogenesis and hypochord differentiation.

The Tübingen large-scale zebrafish genetic screen completed in 1996 identified a set of five genes required for orderly somite segmentation. Four of them have been molecularly identified and three were found to code for components of the Notch pathway, which are required for the coordinated oscillation of gene expression, known as the segmentation clock, in the presomitic mesoderm (PSM). Here, we show that the final member of the group, beamter (bea), codes for the Notch ligand DeltaC, and we present and characterize two new alleles, including one allele encoding for a protein truncated in the 7th EGF repeat and an allele deleting only the DSL domain which was previously shown to be necessary for ligand function. Interestingly however, when we over-express any of the mutant deltaC mRNAs, we observe antimorphic effects on both hindbrain neurogenesis and hypochord formation. Expression of bea/deltaC oscillates in the PSM, and a triple fluorescent in situ analysis of its oscillation in relation to that of other oscillating genes in the PSM reveals differences in subcellular localization of the oscillating mRNAs in individual cells in different oscillation phases. Mutations in aei/deltaD and bea/deltaC differ in the way they disrupt the oscillating expression of her1 and deltaC. Furthermore, we find that the double mutants have significantly stronger defects in hypochord formation but not in somitogenesis or hindbrain neurogenesis, indicating genetically that the two delta's may function either semi-redundantly or distinctly, depending upon context.