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.

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.

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.