Altered blood-brain barrier transport of nanotherapeutics in lysosomal storage diseases

Treatment of neurological lysosomal storage disorders (LSDs) are limited because of impermeability of the blood-brain barrier (BBB) to macromolecules. Nanoformulations targeting BBB transcytosis are being explored, but the status of these routes in LSDs is unknown. We studied nanocarriers (NCs) targeted to the transferrin receptor (TfR), ganglioside GM1 or ICAM1, associated to the clathrin, caveolar or cell adhesion molecule (CAM) routes, respectively. We used brain endothelial cells and mouse models of acid sphingomyelinase-deficient Niemann Pick disease (NPD), and postmortem LSD patients' brains, all compared to respective controls. NC transcytosis across brain endothelial cells and brain distribution in mice were affected, yet through different mechanisms. Reduced TfR and clathrin expression were found, along with decreased transcytosis in cells and mouse brain distribution. Caveolin-1 expression and GM1 transcytosis were also reduced, yet increased GM1 levels seemed to compensate, providing similar NC brain distribution in NPD vs. control mice. A tendency to lower NHE-1 levels was seen, but highly increased ICAM1 expression in cells and human brains correlated with increased transcytosis and brain distribution in mice. Thus, transcytosis-related alterations in NPD and likely other LSDs may impact therapeutic access to the brain, illustrating the need for these mechanistic studies.

Comparison between Nanoparticle Encapsulation and Surface Loading for Lysosomal Enzyme Replacement Therapy

Poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) enhance the delivery of therapeutic enzymes for replacement therapy of lysosomal storage disorders. Previous studies examined NPs encapsulating or coated with enzymes, but these formulations have never been compared. We examined this using hyaluronidase (HAse), deficient in mucopolysaccharidosis IX, and acid sphingomyelinase (ASM), deficient in types A−B Niemann−Pick disease. Initial screening of size, PDI, ζ potential, and loading resulted in the selection of the Lactel II co-polymer vs. Lactel I or Resomer, and Pluronic F68 surfactant vs. PVA or DMAB. Enzyme input and addition of carrier protein were evaluated, rendering NPs having, e.g., 181 nm diameter, 0.15 PDI, −36 mV ζ potential, and 538 HAse molecules encapsulated per NP. Similar NPs were coated with enzyme, which reduced loading (e.g., 292 HAse molecules/NP). NPs were coated with targeting antibodies (> 122 molecules/NP), lyophilized for storage without alterations, and acceptably stable at physiological conditions. NPs were internalized, trafficked to lysosomes, released active enzyme at lysosomal conditions, and targeted both peripheral organs and the brain after i.v. administration in mice. While both formulations enhanced enzyme delivery compared to free enzyme, encapsulating NPs surpassed coated counterparts (18.4- vs. 4.3-fold enhancement in cells and 6.2- vs. 3-fold enhancement in brains), providing guidance for future applications.

Observing the use of knee arthroplasty appropriateness tools in clinical practice: do appropriateness criteria tools predict surgeon decision-making?

OBJECTIVE

The primary aim of this study was to evaluate the agreement between surgeons and two validated total knee arthroplasty (TKA) appropriateness tools, and secondarily to compare Australian appropriateness rates to those reported internationally.

METHODS

A consecutive sample of patients from one public hospital arthroplasty clinic and a convenience sample from private rooms of surgeons in New South Wales, Australia (n = 11), referred for surgical opinion regarding TKA were enrolled over 1 year. Surgeons applied appropriateness tools created by Escobar et al. and the American Academy of Orthopaedic Surgeons (AAOS). Correlation between the appropriateness tools and surgeon's decisions were evaluated.

RESULTS

There were 368 patients enrolled, and contrasting rates of being "appropriate" for surgery were identified between the Escobar (n = 109, 29.6%) and AAOS (n = 292, 79.3%) tools. Surgeon agreement with the Escobar tool was substantial (ĸ = 0.61, 95%CI: 0.53-0.69) compared to slight with the AAOS tool (ĸ = 0.11, 95%CI: 0.06-0.16). Of those advised against TKA (n = 179, 48.6%), the AAOS tool suggested many patients (n = 111, 62.0%) were "appropriate" compared to the Escobar tool (n = 12, 6.7%).

CONCLUSIONS

Surgeons rated patients seeking opinion for TKA as appropriate over half the time, however the AAOS tool had low correlation with surgeons as opposed to the Escobar tool. This was illustrated by both tools rating a majority of patients to be operated on as appropriate, but only the AAOS tool considering most patients not chosen for surgery to be appropriate. When comparing previously published appropriateness rates, appropriateness in Australia, USA, Spain and Qatar was found to be similar.

A method to improve quantitative radiotracing-based analysis of the in vivo biodistribution of drug carriers

Biodistribution studies are essential in drug carrier design and translation, and radiotracing provides a sensitive quantitation for this purpose. Yet, for biodegradable formulations, small amounts of free-label signal may arise prior to or immediately after injection in animal models, causing potentially confounding biodistribution results. In this study, we refined a method to overcome this obstacle. First, we verified free signal generation in animal samples and then, mimicking it in a controllable setting, we injected mice intravenously with a radiolabeled drug carrier formulation (125I-antibody/3DNA) containing a known amount of free radiolabel (125I), or free 125I alone as a control. Corrected biodistribution data were obtained by separating the free radiolabel from blood and organs postmortem, using trichloroacetic acid precipitation, and subtracting the confounding signal from each tissue measurement. Control free 125I-radiolabel was detected at ≥85% accuracy in blood and tissues, validating the method. It biodistributed very heterogeneously among organs (0.6-39 %ID/g), indicating that any free 125I generated in the body or present in an injected formulation cannot be simply corrected to the free-label fraction in the original preparation, but the free label must be empirically measured in each organ. Application of this method to the biodistribution of 125I-antibody/3DNA, including formulations directed to endothelial target ICAM-1, showed accurate classification of free 125I species in blood and tissues. In addition, this technique rendered data on the in vivo degradation of the traced agents over time. Thus, this is a valuable technique to obtain accurate measurements of biodistribution using 125I and possibly other radiotracers.

Intracellular Delivery of Active Proteins by Polyphosphazene Polymers

Achieving intracellular delivery of protein therapeutics within cells remains a significant challenge. Although custom formulations are available for some protein therapeutics, the development of non-toxic delivery systems that can incorporate a variety of active protein cargo and maintain their stability, is a topic of great relevance. This study utilized ionic polyphosphazenes (PZ) that can assemble into supramolecular complexes through non-covalent interactions with different types of protein cargo. We tested a PEGylated graft copolymer (PZ-PEG) and a pyrrolidone containing linear derivative (PZ-PYR) for their ability to intracellularly deliver FITC-avidin, a model protein. In endothelial cells, PZ-PYR/protein exhibited both faster internalization and higher uptake levels than PZ-PEG/protein, while in cancer cells both polymers achieved similar uptake levels over time, although the internalization rate was slower for PZ-PYR/protein. Uptake was mediated by endocytosis through multiple mechanisms, PZ-PEG/avidin colocalized more profusely with endo-lysosomes, and PZ-PYR/avidin achieved greater cytosolic delivery. Consequently, a PZ-PYR-delivered anti-F-actin antibody was able to bind to cytosolic actin filaments without needing cell permeabilization. Similarly, a cell-impermeable Bax-BH3 peptide known to induce apoptosis, decreased cell viability when complexed with PZ-PYR, demonstrating endo-lysosomal escape. These biodegradable PZs were non-toxic to cells and represent a promising platform for drug delivery of protein therapeutics.

Amylase quantification in the terminal Ileum following formation of an Ileostomy

Amylase is elevated in the foregut and has been used to confirm anastomotic integrity after pancreatic surgery. The physiological activity of pancreatic enzymes in the ileum has been studied in healthy volunteers but not quantitated with the simple and readily available amylase measurements employed with serum tests. We aim to quantitate the levels of amylase in the terminal ileum. This was a prospective, non-randomised, non-blinded, consecutive cohort study conducted at the Royal Brisbane and Women's Hospital. Consecutive patients undergoing routine surgery with an ileostomy were invited to participate in the study. Ileostomy effluent was collected and analysed daily for the first 5 post-operative days. This validation cohort included 8 males and 3 females, with a mean age of 49 years. Median daily amylase levels ranged from 4470 U/L to 23,000 U/L, with no specimens falling within the laboratory serum reference range of 40 to 130 U/L. Two specimens were not available on day one post-operative due to complete ileus. The sample size of 11 patients is small but was considered sufficient given that 55 effluent specimens were anticipated for analysis. Amylase levels remain highly elevated as the enzyme transits through the length of the small intestine and measured in the terminal ileum, and can be readily quantitated by the existing testing methodology routinely available.

Anastomotic leak does not affect long-term and longitudinal functional outcomes after ileal pouch surgery for ulcerative colitis when managed aggressively

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is an effective surgical alternative to a permanent ileostomy following proctocolectomy in patients with ulcerative colitis (UC). Anastomotic leakage (AL) is a serious postoperative complication of an intestinal anastomosis that is associated with increased morbidity and mortality. The aim of this study was to evaluate the longitudinal long-term functional outcomes of patients who had IPAA that was complicated by AL.

METHODS

A retrospective longitudinal cohort study was performed of patients who had an IPAA procedure at a tertiary referral centre and a metropolitan private centre in Australia, over a 14-year period (October 2003-October 2017). The long-term functional outcome was assessed using objective clinical measures such as the number of bowel motions during the day and overnight, ability to defer defaecation and the presence of faecal incontinence, and repeated at annual intervals.

RESULTS

A total of 138 patients [mean age 38.5 (± 16.9) years, 72 males] satisfied the inclusion criteria. AL was diagnosed in 14 (10%) patients [mean age 38.8 (± 17) years, 10 males], 11 (79%) of which were managed with surgery. The median bowel motion frequency during the day and overnight remained stable over a median of 62 (28-91) months follow-up, with no significant difference between those who had AL or not (p = 0.6, p = 0.1 respectively). The incidence of faecal incontinence remained low, and the majority of patients in both groups were able to defer defaecation for more than 60 min. Six patients (4.3%) had their pouch excised.

CONCLUSIONS

There is no statistical difference in longitudinal function between patients who experienced AL after IPAA surgery for UC compared with those who did not. Therefore, an acute AL does not negatively impact long-term functional outcomes in IPAA patients.

International variation in managing locally advanced or recurrent rectal cancer: prospective benchmark analysis

BACKGROUND

Tumour extension beyond the mesorectal plane (ymrT4) occurs in 5-10 per cent of patients with rectal cancer and 10 per cent of patients develop locally recurrent rectal cancer (LRRC) after primary surgery. There is global variation in healthcare delivery for these conditions.

METHODS

An international benchmark trial of the management of ymrT4 tumours and LRRC was undertaken in France and Australia between 2015 and 2017. Heterogeneity in management and operative decision-making were analysed by comparison of surgical resection rates, blinded intercountry reading of pelvic MRI, quality-of-life assessment and qualitative evaluations.

RESULTS

Among 154 patients (97 in France and 57 in Australia), 31·8 per cent had ymrT4 disease and 68·2 per cent LRRC. The surgical resection rates were 88 and 79 per cent in France and Australia respectively (P = 0·112). The concordance in operative planning was low (κ = 0·314); the rate of pelvic exenteration was lower in France than Australia both in clinical practice (36 of 78 versus 34 of 40; P < 0·001) and in theoretical conditions (10 of 25 versus 50 of 57; P = 0·002). The R0 resection rate was lower in France than Australia for LRRC (25 of 49 versus 18 of 21; P = 0·007) but not for ymrT4 tumours (21 of 26 versus 15 of 15; P = 0·139). Morbidity rates were similar. Patients who underwent non-exenterative procedures had higher scores on the mental functioning subscale at 12 months (P = 0·047), and a lower level of distress at 6 months (P = 0·049). Qualitative analysis highlighted five categories of psychosocial factors influencing treatment decisions: patient, strategy, specialist, organization and culture.

CONCLUSION

This international benchmark trial has highlighted the differences in worldwide treatment of locally advanced and LRRC. Standardized care should improve outcomes for these patients.

Intertwined mechanisms define transport of anti-ICAM nanocarriers across the endothelium and brain delivery of a therapeutic enzyme

The interaction of drug delivery systems with tissues is key for their application. An example is drug carriers targeted to endothelial barriers, which can be transported to intra-endothelial compartments (lysosomes) or transcellularly released at the tissue side (transcytosis). Although carrier targeting valency influences this process, the mechanism is unknown. We studied this using polymer nanocarriers (NCs) targeted to intercellular adhesion molecule-1 (ICAM-1), an endothelial-surface glycoprotein whose expression is increased in pathologies characterized by inflammation. A bell-shaped relationship was found between NC targeting valency and the rate of transcytosis, where high and low NC valencies rendered less efficient transcytosis rates than an intermediate valency formulation. In contrast, an inverted bell-shape relationship was found for NC valency and lysosomal trafficking rates. Data suggested a model where NC valency plays an opposing role in the two sub-processes involved in transcytosis: NC binding-uptake depended directly on valency and exocytosis-detachment was inversely related to this parameter. This is because the greater the avidity of the NC-receptor interaction the more efficient uptake becomes, but NC-receptor detachment post-transport is more compromised. Cleavage of the receptor at the basolateral side of endothelial cells facilitated NC transcytosis, likely by helping NC detachment post-transport. Since transcytosis encompasses both sets of events, the full process finds an optimum at the intersection of these inverted relationships, explaining the bell-shaped behavior. NCs also trafficked to lysosomes from the apical side and, additionally, from the basolateral side in the case of high valency NCs which are slower at detaching from the receptor. This explains the opposite behavior of NC valency for transcytosis vs. lysosomal transport. Anti-ICAM NCs were verified to traffic into the brain after intravenous injection in mice, and both cellular and in vivo data showed that intermediate valency NCs resulted in higher delivery of a therapeutic enzyme, acid sphingomyelinase, required for types A and B Niemann-Pick disease.

A-03 SCAT5 Cognitive Screening Normative Data and Reliable Change Indices

Objective

This study provides normative data on the SCAT5 Cognitive Screening, establishes test-retest reliability, and creates clinically relevant cut points for low performance.

Method

The multisport baseline sample was composed of 727 uninjured college athletes (52% female) at a Division I university who were administered the SCAT5 before the 2017–2018 season. Descriptive statistics, including base rates of low performance, were calculated for SCAT5 indices. Repeat baseline testing was completed by 325 athletes (48% female) at 1 year (days M = 352.56;SD = 56.03) who were included in the test-retest reliability and practice effect analyses. Reliable change indices were calculated.

Results

Descriptive statistics for SCAT5 were computed for both baselines (Baseline 1: SAC total M = 35.15,SD = 4.93; immediate recall total M = 20.01,SD = 3.46; delayed recall total M = 6.43,SD = 1.75). A difference in descriptive statistics and practice effects by sex on the SCAT5 Cognitive Screening has been demonstrated (Bailey, Meyer, Tangen et al., under review). For female athletes, the 1st administration cutoff scores for abnormal performance (&lt;10th%ile) included SAC total score = 33, immediate recall score = 18, and delayed recall score = 6. For male athletes, the 1st administration cutoff scores for abnormal performance (&lt;10th%ile) included SAC total score = 30, immediate recall score = 17, and delayed recall score = 5. Test-retest reliability of the SAC was similar to previous versions but varied by sex. Reliable change indices (RCI) were created with cut points for significant change.

Conclusions

The present study provides clinically relevant normative data for the SCAT5 Cognitive Screening. Cut points for low performance on both reliable chance indices (RCIs) and normative performance reflected meaningful sex differences that could influence clinical interpretation.

Surgical techniques in the management of rectal cancer: a modified Delphi method by colorectal surgeons in Australia and New Zealand

BACKGROUND

Technological developments have allowed advances in minimally invasive techniques for total mesorectal excision such as laparoscopy, robotics, and transanal surgery. There remains an ongoing debate about the safety, benefits, and appropriate clinical scenarios for which each technique is employed. The aim of this study was to provide a panel of expert opinion on the role of each surgical technique currently available in the management of rectal cancer using a modified Delphi method.

METHODS

Surveys were designed to explore the key patient- and tumor-related factors including clinical scenarios for determining a surgeon's choice of surgical technique.

RESULTS

Open surgery was favoured in obese patients with an extra-peritoneal tumor and a positive circumferential resection margin (CRM) or T4 tumor when a restorative resection was planned. Laparoscopy was favoured in non-obese males and females, in both intra- and extra-peritoneal tumors with a clear CRM. Robotic surgery was most commonly offered to obese patients when the CRM was clear and if an abdominoperineal resection was planned. Transanal total mesorectal excision (taTME) was preferred in male patients with a mid or low rectal cancer, particularly when obese. Transanal endoscopic microsurgery/transanal minimally invasive surgery local excision was only offered to frail patients with small, early stage tumors.

CONCLUSIONS

All surgical techniques for rectal cancer dissection have a role and may be considered appropriate. Some techniques have advantages over others in certain clinical situations, and the best outcomes may be achieved by considering all options before applying an individualised approach to each clinical situation.

δ-Tocopherol Effect on Endocytosis and Its Combination with Enzyme Replacement Therapy for Lysosomal Disorders: A New Type of Drug Interaction?

Induction of lysosomal exocytosis alleviates lysosomal storage of undigested metabolites in cell models of lysosomal disorders (LDs). However, whether this strategy affects other vesicular compartments, e.g., those involved in endocytosis, is unknown. This is important both to predict side effects and to use this strategy in combination with therapies that require endocytosis for intracellular delivery, such as lysosomal enzyme replacement therapy (ERT). We investigated this using δ-tocopherol as a model previously shown to induce lysosomal exocytosis and cell models of type A Niemann-Pick disease, a LD characterized by acid sphingomyelinase (ASM) deficiency and sphingomyelin storage. δ-Tocopherol and derivative CF3-T reduced net accumulation of fluid phase, ligands, and polymer particles via phagocytic, caveolae-, clathrin-, and cell adhesion molecule (CAM)-mediated pathways, yet the latter route was less affected due to receptor overexpression. In agreement, δ-tocopherol lowered uptake of recombinant ASM by deficient cells (known to occur via the clathrin pathway) and via targeting intercellular adhesion molecule-1 (associated to the CAM pathway). However, the net enzyme activity delivered and lysosomal storage attenuation were greater via the latter route. Data suggest stimulation of exocytosis by tocopherols is not specific of lysosomes and affects endocytic cargo. However, this effect was transient and became unnoticeable several hours after tocopherol removal. Therefore, induction of exocytosis in combination with therapies requiring endocytic uptake, such as ERT, may represent a new type of drug interaction, yet this strategy could be valuable if properly timed for minimal interference.

Unprecedently high targeting specificity toward lung ICAM-1 using 3DNA nanocarriers

DNA nanostructures hold great potential for drug delivery. However, their specific targeting is often compromised by recognition by scavenger receptors involved in clearance. In our previous study in cell culture, we showed targeting specificity of a 180 nm, 4-layer DNA-built nanocarrier called 3DNA coupled with antibodies against intercellular adhesion molecule-1 (ICAM-1), a glycoprotein overexpressed in the lungs in many diseases. Here, we examined the biodistribution of various 3DNA formulations in mice. A formulation consisted of 3DNA whose outer-layer arms were hybridized to secondary antibody-oligonucleotide conjugates. Anchoring IgG on this formulation reduced circulation and kidney accumulation vs. non-anchored IgG, while increasing liver and spleen clearance, as expected for a nanocarrier. Anchoring anti-ICAM changed the biodistribution of this antibody similarly, yet this formulation specifically accumulated in the lungs, the main ICAM-1 target. Since lung targeting was modest (2-fold specificity index over IgG formulation), we pursued a second preparation involving direct hybridization of primary antibody-oligonucleotide conjugates to 3DNA. This formulation had prolonged stability in serum and showed a dramatic increase in lung distribution: the specificity index was 424-fold above a matching IgG formulation, 144-fold more specific than observed for PLGA nanoparticles of similar size, polydispersity, ζ-potential and antibody valency, and its lung accumulation increased with the number of anti-ICAM molecules per particle. Immunohistochemistry showed that anti-ICAM and 3DNA components colocalized in the lungs, specifically associating with endothelial markers, without apparent histological changes. The degree of in vivo targeting for anti-ICAM/3DNA-nanocarriers is unprecedented, for which this platform technology holds great potential to develop future therapeutic applications.

Drain fluid amylase as a sensitive biomarker for the early detection of anastomotic leakage in ileal pouch surgery

AIM

We studied the levels of amylase in drain fluid to investigate its utility as a biomarker of anastomotic leak in ileal pouch patients who did not have a covering loop ileostomy. The luminal contents of the small intestine are high in amylase. Ileal J pouches are formed for restoration of continuity in patients with ulcerative colitis after removal of the colon and rectum. A drain is placed alongside the ileal pouch in the pelvis.

METHOD

This study is a retrospective analysis of prospectively collected daily drain fluid amylase levels in consecutive patients undergoing restorative proctectomy and ileal J pouch anal anastomosis, without a covering loop ileostomy, between November 2016 and April 2018.

RESULTS

Thirteen patients underwent surgery without a covering loop ileostomy. Two patients suffered an anastomotic leak and were returned to theatre, one on day 5 and the other on day 6 postoperatively. The mean daily drain fluid amylase level in those who did not leak was between 25 and 46 U/l with a range of 22-139 U/l for all samples collected. In the two patients who suffered a clinical leak the drain fluid amylase level rose to 22 432 and 10 212 U/l on the day of clinical leak diagnosis. The mean rectal tube (intraluminal) amylase level was 63 097 U/l as measured on day 1 postoperatively.

CONCLUSION

In this small cohort of patients, the measurement of drain fluid amylase is a highly sensitive biomarker of clinical anastomotic leak.

Pathways to Diagnosis and Treatment of Patients With Oropharynx, Oral Cavity, and Cutaneous Squamous Cell Carcinoma in New South Wales, Australia

Background: Early cancer diagnosis is a critical component of comprehensive cancer control, however more than 50% of head and neck cancers (HNCs) are diagnosed at advanced stage. HNC patients from regional/remote areas are less likely to use radiotherapy during treatment and have poorer survival outcomes than metropolitan patients. Aim: The aim of this study was to examine pathways to treatment of patients with HNC in New South Wales (NSW) and associations between duration of components of the pathway with survival. Methods: Patients diagnosed with squamous cell carcinoma (SCC) of the oral cavity, oropharynx, or cutaneous SCC from 1st July 2008 to 30th June 2013 were identified from a prospectively maintained database. Data were extracted and supplemented by a retrospective audit of medical records at Royal Prince Alfred Hospital and specialists' records. Results: Two hundred and fifty eligible patients were identified (78% male) with mean (SD) age at diagnosis 64.5 (13.5) years. At diagnosis, 75%, 24% and 1% lived in metropolitan, regional and remote areas of NSW, respectively. Twelve per cent of patients lived > 100 km from a hospital with a HNC multidisciplinary team (median [IQR] 7.5 km [25.1]). More than two-thirds (69%) of tumors were diagnosed as advanced stage, and mean follow-up time was 3.5 years. We will present additional findings quantifying intervals along the pathway to treatment (from symptom onset, first specialist visit, diagnosis and treatment), and the associations with survival, and compare findings to those from a second regional site on the mid north coast of NSW. Conclusion: An increasing proportion of the NSW population resides outside major cities. This study is the first step in understanding patient and health system factors that facilitate and impede early diagnosis of HNC. Findings from this study may be used to develop interventions aimed at improving early HNC diagnosis.

Patterns of kidney injury in pediatric nonkidney solid organ transplant recipients

The incidence of acute kidney injury (AKI) and its impact on chronic kidney disease (CKD) following pediatric nonkidney solid organ transplantation is unknown. We aimed to determine the incidence of AKI and CKD and examine their relationship among children who received a heart, lung, liver, or multiorgan transplant at the Hospital for Sick Children between 2002 and 2011. AKI was assessed in the first year posttransplant. Among 303 children, perioperative AKI (within the first week) occurred in 67% of children, and AKI after the first week occurred in 36%, with the highest incidence among lung and multiorgan recipients. Twenty-three children (8%) developed CKD after a median follow-up of 3.4 years. Less than 5 children developed end-stage renal disease, all within 65 days posttransplant. Those with 1 AKI episode by 3 months posttransplant had significantly greater risk for developing CKD after adjusting for age, sex, and estimated glomerular filtration rate at transplant (hazard ratio: 2.77, 95% confidence interval, 1.13-6.80, P trend = .008). AKI is common in the first year posttransplant and associated with significantly greater risk of developing CKD. Close monitoring for kidney disease may allow for earlier implementation of kidney-sparing strategies to decrease risk for progression to CKD.

Dynamic and Depth Dependent Nanomechanical Properties of Dorsal Ruffles in Live Cells and Biopolymeric Hydrogels

The nanomechanical properties of various biological and cellular surfaces are increasingly investigated with Scanning Probe Microscopy. Surface stiffness measurements are currently being used to define metastatic properties of various cancerous cell lines and other related biological tissues. Here we present a unique methodology to understand depth dependent nanomechanical variations in stiffness in biopolymers and live cells. In this study we have used A2780 and NIH3T3 cell lines and 0.5% and 1% Agarose to investigate depth dependent stiffness and porosity on nanomechanical properties in different biological systems. This analytical methodology can circumvent the issue associated with the contribution of substrates on cell stiffness. Here we demonstrate that by calculating 'continuous-step-wise-modulus' on force versus distance curves one can observe minute variation as function of depth. Due to the presence of different kinds of cytoskeletal filament, dissipation of contact force might vary from one portion of a cell to another. On NIH3T3 cell lines, stiffness profile of Circular Dorsal Ruffles could be observed in form of large parabolic feature with changes in stiffness at different depth. In biopolymers like agarose, depending upon the extent of polymerization in there can be increase or decrease in stiffness due variations in pore size and extent to which crosslinking is taking place at different depths. 0.5% agarose showed gradual decrease in stiffness whereas with 1% agarose there was slight increase in stiffness as one indents deeper into its surface.

Co-coating of receptor-targeted drug nanocarriers with anti-phagocytic moieties enhances specific tissue uptake versus non-specific phagocytic clearance

Nanocarriers (NCs) help improve the performance of therapeutics, but their removal by phagocytes in the liver, spleen, tissues, etc. diminishes this potential. Although NC functionalization with polyethylene glycol (PEG) lowers interaction with phagocytes, it also reduces interactions with tissue cells. Coating NCs with CD47, a protein expressed by body cells to avoid phagocytic removal, offers an alternative. Previous studies showed that coating CD47 on non-targeted NCs reduces phagocytosis, but whether this alters binding and endocytosis of actively-targeted NCs remains unknown. To evaluate this, we used polymer NCs targeted to ICAM-1, a receptor overexpressed in many diseases. Co-coating of CD47 on anti-ICAM NCs reduced macrophage phagocytosis by ∼50% for up to 24 h, while increasing endothelial-cell targeting by ∼87% over control anti-ICAM/IgG NCs. Anti-ICAM/CD47 NCs were endocytosed via the CAM-mediated pathway with efficiency similar (0.99-fold) to anti-ICAM/IgG NCs. Comparable outcomes were observed for NCs targeted to PECAM-1 or transferrin receptor, suggesting broad applicability. When injected in mice, anti-ICAM/CD47 NCs reduced liver and spleen uptake by ∼30-50% and increased lung targeting by ∼2-fold (∼10-fold over IgG NCs). Therefore, co-coating NCs with CD47 and targeting moieties reduces macrophage phagocytosis and improves targeted uptake. This strategy may significantly improve the efficacy of targeted drug NCs.

Cell-based high-throughput screening identifies galactocerebrosidase enhancers as potential small-molecule therapies for Krabbe's disease

Krabbe's disease, also known as globoid cell leukodystrophy (GLD), is a lysosomal storage disease caused by the deficiency of the lysosomal enzyme β-galactocerebrosidase (GALC), resulting in severe neurological manifestations related to demyelination secondary to elevated galactosylsphingosine (psychosine) with its subsequent cytotoxicity. The only available treatment is hematopoietic stem cell transplantation, which delays disease onset but does not prevent long-term neurological manifestations. This article describes the identification of small molecules that enhance mutant GALC activity, identified by quantitative cell-based high-throughput screening (qHTS). Using a specific neurologically relevant murine cell line (145M-Twi) modified to express common human hGALC-G270D mutant, we were able to detect GALC activity in a 1,536-well microplate format. The qHTS of approximately 46,000 compounds identified three small molecules that showed significant enhancements of residual mutant GALC activity in primary cell lines from GLD patients. These compounds were shown to increase the levels of GALC-G270D mutant in the lysosomal compartment. In kinetic assessments, these small molecules failed to disturb the GALC kinetic profile under acidic conditions, which is highly desirable for folding-assisting molecules operating in the endoplasmic reticulum and not affecting GALC catalytic properties in the lysosomal compartment. In addition, these small molecules rescued the decreased GALC activity at neutral pH and partially stabilized GALC under heat-denaturating conditions. These drug-like compounds can be used as the starting point to develop novel small-molecule agents to treat the progressive neurodegenerative course of GLD. © 2016 Wiley Periodicals, Inc.

Lysosomal enzyme replacement therapies: Historical development, clinical outcomes, and future perspectives

Lysosomes and lysosomal enzymes play a central role in numerous cellular processes, including cellular nutrition, recycling, signaling, defense, and cell death. Genetic deficiencies of lysosomal components, most commonly enzymes, are known as "lysosomal storage disorders" or "lysosomal diseases" (LDs) and lead to lysosomal dysfunction. LDs broadly affect peripheral organs and the central nervous system (CNS), debilitating patients and frequently causing fatality. Among other approaches, enzyme replacement therapy (ERT) has advanced to the clinic and represents a beneficial strategy for 8 out of the 50-60 known LDs. However, despite its value, current ERT suffers from several shortcomings, including various side effects, development of "resistance", and suboptimal delivery throughout the body, particularly to the CNS, lowering the therapeutic outcome and precluding the use of this strategy for a majority of LDs. This review offers an overview of the biomedical causes of LDs, their socio-medical relevance, treatment modalities and caveats, experimental alternatives, and future treatment perspectives.

Enhanced Delivery and Effects of Acid Sphingomyelinase by ICAM-1-Targeted Nanocarriers in Type B Niemann-Pick Disease Mice

Acid sphingomyelinase deficiency in type B Niemann-Pick disease leads to lysosomal sphingomyelin storage, principally affecting lungs, liver, and spleen. Infused recombinant enzyme is beneficial, yet its delivery to the lungs is limited and requires higher dosing than liver and spleen, leading to potentially adverse reactions. Previous studies showed increased enzyme pulmonary uptake by nanocarriers targeted to ICAM-1, a protein overexpressed during inflammation. Here, using polystyrene and poly(lactic-co-glycolic acid) nanocarriers, we optimized lung delivery by varying enzyme dose and nanocarrier concentration, verified endocytosis and lysosomal trafficking in vivo, and evaluated delivered activity and effects. Raising the enzyme load of nanocarriers progressively increased absolute enzyme delivery to all lung, liver, and spleen, over the naked enzyme. Varying nanocarrier concentration inversely impacted lung versus liver and spleen uptake. Mouse intravital and postmortem examination verified endocytosis, transcytosis, and lysosomal trafficking using nanocarriers. Compared to naked enzyme, nanocarriers increased enzyme activity in organs and reduced lung sphingomyelin storage and macrophage infiltration. Although old mice with advanced disease showed reactivity (pulmonary leukocyte infiltration) to injections, including buffer without carriers, antibody, or enzyme, younger mice with mild disease did not. We conclude that anti-ICAM nanocarriers may result in effective lung enzyme therapy using low enzyme doses.

Variation in functional pelvic tilt in patients undergoing total hip arthroplasty

Aims

The pelvis rotates in the sagittal plane during daily activities. These rotations have a direct effect on the functional orientation of the acetabulum. The aim of this study was to quantify changes in pelvic tilt between different functional positions.

Patients and Methods

Pre-operatively, pelvic tilt was measured in 1517 patients undergoing total hip arthroplasty (THA) in three functional positions – supine, standing and flexed seated (the moment when patients initiate rising from a seated position). Supine pelvic tilt was measured from CT scans, standing and flexed seated pelvic tilts were measured from standardised lateral radiographs. Anterior pelvic tilt was assigned a positive value.

Results

The mean pelvic tilt was 4.2° (-20.5° to 24.5°), -1.3° (-30.2° to 27.9°) and 0.6° (-42.0° to 41.3°) in the three positions, respectively. The mean sagittal pelvic rotation from supine to standing was -5.5° (-21.8° to 8.4°), from supine to flexed seated was -3.7° (-48.3° to 38.6°) and from standing to flexed seated was 1.8° (-51.8° to 39.5°). In 259 patients (17%), the extent of sagittal pelvic rotation could lead to functional malorientation of the acetabular component. Factoring in an intra-operative delivery error of ± 5° extends this risk to 51% of patients.

Conclusion

Planning and measurement of the intended position of the acetabular component in the supine position may fail to predict clinically significant changes in its orientation during functional activities, as a consequence of individual pelvic kinematics. Optimal orientation is patient-specific and requires an evaluation of functional pelvic tilt pre-operatively. Cite this article: Bone Joint J 2017;99-B:184–91.

The adaptation of health care marketing to the digital era

The purpose of health care marketing is to learn and understand the needs and desires of prospective patients in order to be able to meet those necessities at the highest standards. A big advantage is the targeting capability of the electronic media that has led to its being used by managers of marketing in medical institutions as means of advertisement when they develop the marketing strategies. Regarding social media, it is safe to say that there are communication platforms that can promote certain behaviours thus influencing decision-making. Through social media, people stay in touch with other people and they can provide a mean for medical institutions to permanently communicate with the existing patients or with the potential ones. In addition, social media can be used in advertising and promoting strategies, by posting information about discounts, offers and advantages of accessing the products provided by a certain institution. A study was conducted on 126 patients of a dental clinic in Bucharest. 126 new patients were selected on a period of 22 months from January 2015 until October 2016. The patients never had any treatment in this clinic and were influenced by the Internet to seek for dental care services. The purpose of this study was to evaluate the digital methods of promoting medical services, bringing new patients to a clinic. The results of the study demonstrated the need for digital methods of promoting medical care services in order to expand a business. A strategic way of thinking in this case implied attracting new patients and offering them quality health care services, which ensured their satisfaction and the probability of their recommending the health facility further. This study revealed an important role of social networking sites in promoting. This high response was probably responsible due to targeted promoting services. Almost all the new patients who completed the form will remain patients of this clinic in future.

Impact of schizophrenia on anterior and posterior hippocampus during memory for complex scenes

Objectives

Hippocampal dysfunction has been proposed as a mechanism for memory deficits in schizophrenia. Available evidence suggests that the anterior and posterior hippocampus could be differentially affected. Accordingly, we used fMRI to test the hypothesis that activity in posterior hippocampus is disproportionately reduced in schizophrenia, particularly during spatial memory retrieval.

Methods

26 healthy participants and 24 patients with schizophrenia from the UC Davis Early Psychosis Program were studied while fMRI was acquired on a 3 Tesla Siemens scanner. During encoding, participants were oriented to critical items through questions about item features (e.g., “Does the lamp have a square shade?”) or spatial location (e.g., “Is the lamp on the table next to the couch?”). At test, participants determined whether scenes were changed or unchanged. fMRI analyses contrasted activation in a priori regions of interest (ROI) in anterior and posterior hippocampus during correct recognition of item changes and spatial changes.

Results

As predicted, patients with schizophrenia exhibited reduced activation in the posterior hippocampus during detection of spatial changes but not during detection of item changes. Unexpectedly, patients exhibited increased activation of anterior hippocampus during detection of item changes. Whole brain analyses revealed reduced fronto-parietal and striatal activation in patients for spatial but not for item change trials.

Conclusions

Results suggest a gradient of hippocampal dysfunction in which posterior hippocampus – which is necessary for processing fine-grained spatial relationships – is underactive, and anterior hippocampus – which may process context more globally - is overactive.

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Patients with schizophrenia show impaired memory for spatial relationships amongst objects in scenes.

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Patients have less posterior hippocampal activation during spatial memory and more anterior hippocampal activation during item memory.

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This gradient of hippocampal dysfunction in schizophrenia, suggests that it should not be examined as a unitary structure in future studies.

An Evaluation of Rural Health Care Research

This article reviews the state of the art of rural health research and evaluation with par ticular emphasis on the questions of access, health personnel, and financing. The current state of knowledge both in the published and in the unpublished literature in each area is summarized and a series of unresolved issues is proposed. A strategy for further research to include the various types of rural health care programs is described. Major findings suggest that, although rural populations do have somewhat less access to care than do urban populations, our ability to quantify precisely the extent and importance of this discrepancy is underdeveloped. Despite a substantial investment in a variety of rural health care programs there is inadequate information as to their effectiveness. Programs designed to increase the supply of health personnel to rural areas have met with mixed success. Sites staffed by National Health Service Corps personnel show consistently lower productivity than do sites under other sponsorship. Nonphysician personnel (physician assistants and nurse practitioners) offer apromising source of primary carefor rural areas; recent legislation that reimburses such care should increase their utilization. A persistent problem is the expectation (often a mandate) incorporated into many rural health care demonstration efforts that the programs become financially self-sufficient in a finite period of time. Self-sufficiency is a function of utilization, productivity, and the ability to recover charges for services. In many instances stringent enforcement of the self-suf ficiency requirement may mean those those who need the services most will be least likely to receive them.

Expert consensus v. evidence-based approaches in the revision of the DSM

The development of DSM-III through DSM-5 has relied heavily on expert consensus. In this essay, we provide an historical and critical perspective on this process. Over the last 40 years, medicine has struggled to find appropriate methods for summarizing research results and making clinical recommendations. When such recommendations are issued by authorized organizations, they can have widespread influence (i.e. DSM-III and its successors). In the 1970s, expert consensus conferences, led by the NIH, reviewed research about controversial medical issues and successfully disseminated results. However, these consensus conferences struggled with aggregating the complex available evidence. In the 1990s, the rise of evidence-based medicine cast doubt on the reliability of expert consensus. Since then, medicine has increasingly relied on systematic reviews, as developed by the evidence-based medicine movement, and advocated for their early incorporation in expert consensus efforts. With the partial exception of DSM-IV, such systematic evidence-based reviews have not been consistently integrated into the development of the DSMs, leaving their development out of step with the larger medical field. Like the recommendations made for the NIH consensus conferences, we argue that the DSM process should be modified to require systematic evidence-based reviews before Work Groups make their assessments. Our suggestions - which would require leadership and additional resources to set standards for appropriate evidence hierarchies, carry out systematic reviews, and upgrade the group process - should improve the objectivity of the DSM, increase the validity of its results, and improve the reception of any changes in nosology.

A Comparative Study on the Alterations of Endocytic Pathways in Multiple Lysosomal Storage Disorders

Many cellular activities and pharmaceutical interventions involve endocytosis and delivery to lysosomes for processing. Hence, lysosomal processing defects can cause cell and tissue damage, as in lysosomal storage diseases (LSDs) characterized by lysosomal accumulation of undegraded materials. This storage causes endocytic and trafficking alterations, which exacerbate disease and hinder treatment. However, there have been no systematic studies comparing different endocytic routes in LSDs. Here, we used genetic and pharmacological models of four LSDs (type A Niemann-Pick, type C Niemann-Pick, Fabry, and Gaucher diseases) and evaluated the pinocytic and receptor-mediated activity of the clathrin-, caveolae-, and macropinocytic routes. Bulk pinocytosis was diminished in all diseases, suggesting a generic endocytic alteration linked to lysosomal storage. Fluid-phase (dextran) and ligand (transferrin) uptake via the clathrin route were lower for all LSDs. Fluid-phase and ligand (cholera toxin B) uptake via the caveolar route were both affected but less acutely in Fabry or Gaucher diseases. Epidermal growth factor-induced macropinocytosis was altered in Niemann-Pick cells but not other LSDs. Intracellular trafficking of ligands was also distorted in LSD versus wild-type cells. The extent of these endocytic alterations paralleled the level of cholesterol storage in disease cell lines. Confirming this, pharmacological induction of cholesterol storage in wild-type cells disrupted endocytosis, and model therapeutics restored uptake in proportion to their efficacy in attenuating storage. This suggests a proportional and reversible relationship between endocytosis and lipid (cholesterol) storage. By analogy, the accumulation of biological material in other diseases, or foreign material from drugs or their carriers, may cause similar deficits, warranting further investigation.

Development of a conceptual framework of health-related quality of life in locally recurrent rectal cancer

AIM

The surgical management of locally recurrent rectal cancer (LRRC) has become widely accepted to afford cure and improve quality of life in this subset of patients. Thus far, traditional surgical and oncological markers have been used to highlight the success of surgical intervention. The use of patient-reported outcomes, specifically health-related quality of life (HRQoL), is sparse in these patients. This may be in part due to the lack of well-designed, validated instruments. This study identifies HRQoL issues relevant to patients undergoing surgery for LRRC, with the aim of developing a conceptual framework of HRQoL specific to LRRC to enable measurement of patient-reported outcomes in this cohort of patients.

METHOD

Qualitative focus groups were undertaken at two institutions to identify relevant HRQoL themes. The principles of thematic content analysis were used to analysis data. NViVo10 was used to analyse data.

RESULTS

Twenty-one patients participated in six consecutive focus groups. Two patterns of themes emerged related to HRQoL and healthcare service delivery and utilization. Identified themes related to HRQoL included symptoms, sexual function, psychological impact, role and social functioning and future perspective. Under healthcare service and delivery and utilization the subdomain of disease management, treatment expectations and healthcare professionals were identified.

CONCLUSION

This is the first qualitative study undertaken exclusively in patients with LRRC to ascertain relevant HRQoL outcomes. The impact of LRRC on patients is wide-ranging and extends beyond traditional HRQoL outcomes. The study operationalizes the identified outcomes into a conceptual framework, which will provide the basis for the development of a LRRC-specific patient-reported outcome measure.

Unusual forms of cutaneous leishmaniasis due to Leishmania major

BACKGROUND

Cutaneous leishmaniasis (CL) due to Leishmania major (L. major) is common in the Middle East; however, this skin infection may be under-diagnosed when it presents atypically.

OBJECTIVE

To highlight the occurrence of uncommon presentations of CL that may elude diagnosis.

MATERIALS AND METHODS

A retrospective study was performed among patients who presented at The Sheba Medical Center between 2005 and 2014 with atypical clinical presentations of CL due to L. major.

RESULTS

Twelve patients with unusual clinical presentations of L. major CL were identified. All infections were acquired in L. major - endemic areas of Israel. The average age was 37 years. The average number of lesions was 2. Nine patients presented with a form that mimicked other forms of CL, such as lupoid, giant ulcer, sporotrichoid and recidivans, and three had a variant resembling other infectious skin diseases, such as erysipeloid and verruciform. All patients required systemic therapy.

CONCLUSION

Cutaneous leishmaniasis due to L. major can masquerade as many other infectious and inflammatory diseases. In addition, it can mimic clinical forms of New World CL. We suggest that in endemic countries or in travellers returning from countries where L. major is endemic, polymerase chain reaction (PCR) for Leishmania-specific DNA should be performed routinely in cases of unusual presentations of dermatitis with a single or a few lesions, even if a diagnosis of CL was not considered by the referring clinician.

Late-onset onchocercal skin disease among Ethiopian immigrants

BACKGROUND

Onchocerciasis is an infectious disease caused by the filaria Onchocerca volvulus. Very little is known regarding onchocerciasis imported from endemic to nonendemic areas.

OBJECTIVES

To evaluate pruritic dermatitis simulating atopic dermatitis in Ethiopian immigrants in Israel.

PATIENTS AND METHODS

A retrospective study of 27 Ethiopian immigrants to Israel was conducted. Demographics and clinical and laboratory data were collected.

RESULTS

Of the group of 27 patients, 10 (37%) were men and 17 (63%) were women. The average age at referral was 29 years. All of the patients emigrated from Kuwara, Ethiopia. Diagnosis was done by either positive skin snip test or immunoglobulin (Ig) G4 serology of onchocerciasis in 14 patients. The most common presentation was a combination of lichenified onchodermatitis with atrophy and depigmentation (36%). Eosinophilia and elevated IgE levels were common. Seventeen patients were treated with a single administration of oral ivermectin 200 μg mg(-1). Thirteen patients responded to the treatment.

CONCLUSIONS

Immigrants from endemic regions to developed countries presenting with pruritic diseases, especially those with a clinical picture suggestive of atopic dermatitis, should be evaluated for possible onchocerciasis infection. Ivermectin, a relatively safe and low-cost treatment, should be considered even in the absence of a proven disease. Physicians should have a high index of suspicion in patients with the corresponding residential history.

Early axonal loss accompanied by impaired endocytosis, abnormal axonal transport, and decreased microtubule stability occur in the model of Krabbe's disease

In Krabbe's disease (KD), a leukodystrophy caused by β-galactosylceramidase deficiency, demyelination and a myelin-independent axonopathy contributes to the severe neuropathology. Beyond axonopathy, we show that in Twitcher mice, a model of KD, a decreased number of axons both in the PNS and in the CNS, and of neurons in dorsal root ganglia (DRG), occurred before the onset of demyelination. Despite the early axonal loss, and although in vitro Twitcher neurites degenerated over time, Twitcher DRG neurons displayed an initial neurite overgrowth and, following sciatic nerve injury, Twitcher axons were regeneration-competent, at a time point where axonopathy was already ongoing. Psychosine, the toxic substrate that accumulates in KD, induced lipid raft clustering. At the mechanistic level, TrkA recruitment to lipid rafts was dysregulated in Twitcher neurons, and defective activation of the ERK1/2 and AKT pathways was identified. Besides defective recruitment of signaling molecules to lipid rafts, the early steps of endocytosis and the transport of endocytic and synaptic vesicles were impaired in Twitcher DRG neurons. Defects in axonal transport, specifically in the retrograde component, correlated with decreased levels of dynein, abnormal levels of post-translational tubulin modifications and decreased microtubule stability. The identification of the axonal defects that precede demyelination in KD, together with the finding that Twitcher axons are regeneration-competent when axonopathy is already installed, opens new windows of action to effectively correct the neuropathology that characterizes this disorder.

Decision-making in rectal surgery

AIM

The decision to create a stoma after anterior resection has significant consequences. Decisions under uncertainty are made with a variety of cognitive tools, or heuristics. Past experience has been shown to be a powerful heuristic in other domains. Our aim was to identify whether the misfortune of recent anastomotic leakage or surgeon propensity to take everyday risks would affect their decision to defunction a range of anastomoses.

METHOD

Questionnaires were sent to members of the Colorectal Surgical Society of Australia and New Zealand. Participants were asked for demographic information, questions regarding risk-taking propensity, when their last anastomotic leakage occurred and whether they would defunction a range of hypothetical rectal anastomoses grouped according to height, American Society of Anesthesiologists grade and use of preoperative radiotherapy. Scores were derived for hypothetical patient likelihood of having a stoma created and individual surgeon propensity for stoma formation. Hazard regression analysis was used to assess demographic predictors of stoma formation.

RESULTS

In total, 110 (75.3%) of 146 surveyed surgeons replied; 72 (65.5%) reported anastomotic leakage within the last 12 months. Surgeons' propensity for risk-taking was comparable (24.6 vs 27.53, 95% confidence interval, Mann-Whitney-U) to previously studied participants in economic models. Surgeon age (< 50 years) and lower propensity for risk-taking were demonstrated to be independent predictors of stoma formation on regression analysis.

CONCLUSION

Although the decision to create a stoma after anterior resection may be made in the belief that its foundation derives from rational thought, it appears that other unrecognized operator factors such as age and risk-taking exert an effect.

Abstract P2-18-06: Preservation or division of the intercostobrachial nerve in axillary dissection for breast cancer: Meta-analysis of randomised controlled trials

Purpose: Management of the ICBN during axillary dissection is controversial and the division of ICBN is often trivialised.The effect of dividing the ICBN, and its association with sensory disturbance, is unclear. A systemic review and meta-analysis was performed to evaluate the effect of preserving the ICBN during axillary dissection.

Methods: A systemic literature review and meta-analysis was performed according to the PRISMA and Cochrane Collaboration guidelines. Two authors (SW and SH) independently searched Medline, Pubmed, Embase, Cochrane Database of Systemic Reviews and the Cochrane Controlled Trials Register from 1950 to December 2012 for studies comparing preservation or division of the ICBN in axillary dissection for breast cancer. The primary outcome of this meta-analysis was sensory disturbance, defined as objectively assessed change in sensation in the distribution of the ICBN after axillary dissection. The nature of sensory disturbance was assessed as a secondary outcome, categorised into two types: “hypersensitivity” and “hyposensitivity”.

Results: Three RCTs and four non-RCTs were reviewed. A meta-analysis demonstrated that the incidence of sensory disturbance was significantly lower with preservation of ICBN compared to division of the ICBN with Mantel-Haenzel combined odds ratio 0.31 (0.17-0.57, 95% CI). There was relatively low level of heterogeneity (I2 = 19%, c2 = 2.48, df = 2).

The sensory disturbance was more likely to be hyposensitivity when compared to hypersensitivity (p &lt;0.0001). No difference on number of lymph nodes dissected or operating time was noted.

Conclusion: This meta-analysis demonstrates that division of the ICBN is associated with higher risk of sensory disturbance, and that the nature of this sensory disturbance is more likely to be hyposensitivity, attributable to reduced nerve function.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-06.

Cognitive abilities on transitive inference using a novel touchscreen technology for mice

Cognitive abilities are impaired in neurodevelopmental disorders, including autism spectrum disorder (ASD) and schizophrenia. Preclinical models with strong endophenotypes relevant to cognitive dysfunctions offer a valuable resource for therapeutic development. However, improved assays to test higher order cognition are needed. We employed touchscreen technology to design a complex transitive inference (TI) assay that requires cognitive flexibility and relational learning. C57BL/6J (B6) mice with good cognitive skills and BTBR T+tf/J (BTBR), a model of ASD with cognitive deficits, were evaluated in simple and complex touchscreen assays. Both B6 and BTBR acquired visual discrimination and reversal. BTBR displayed deficits on components of TI, when 4 stimuli pairs were interspersed, which required flexible integrated knowledge. BTBR displayed impairment on the A > E inference, analogous to the A > E deficit in ASD. B6 and BTBR mice both reached criterion on the B > D comparison, unlike the B > D impairment in schizophrenia. These results demonstrate that mice are capable of complex discriminations and higher order tasks using methods and equipment paralleling those used in humans. Our discovery that a mouse model of ASD displays a TI deficit similar to humans with ASD supports the use of the touchscreen technology for complex cognitive tasks in mouse models of neurodevelopmental disorders.

Effects of an acute, outpatient physiotherapy exercise program following pediatric heart or lung transplantation

This prospective interventional study investigated the impact of a three-month, ambulatory HA or HB, semi-individualized, PT-prescribed exercise program following pediatric HTx or LTx. SMW distance, strength, and flexibility were assessed at start and completion of the program and one yr after enrollment. Subjects received either an HB or HA exercise program three times per week. The cohort demonstrated clinically and statistically significant improvements in SMW distances at three months (425.7 ± 109.4-500.6 ± 93.6 m, p < 0.001) and at one yr (528.5 ± 66.6 m, p = 0.001), although there was no difference between the two groups at any time. Similar improvements were also observed in strength and flexibility measures. Correlates with higher SMW distance at three months and one yr included older age, male gender, and underlying diagnosis other than CHD. Male gender and diagnosis other than CHD were associated with a slower improvement in the SMW distance. This is the first report of institutionally based, outpatient exercise rehabilitation in the recovery following pediatric thoracic transplantation. We found similar improvements to HB interventions up to one yr after surgery. Further study of the role of exercise rehabilitation and long-term fitness outcomes is needed.