Stem cell-based therapeutic applications in retinal degenerative diseases

Retinal degenerative diseases that target photoreceptors or the adjacent retinal pigment epithelium (RPE) affect millions of people worldwide. Retinal degeneration (RD) is found in many different forms of retinal diseases including retinitis pigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, cataracts, and glaucoma. Effective treatment for retinal degeneration has been widely investigated. Gene-replacement therapy has been shown to improve visual function in inherited retinal disease. However, this treatment was less effective with advanced disease. Stem cell-based therapy is being pursued as a potential alternative approach in the treatment of retinal degenerative diseases. In this review, we will focus on stem cell-based therapies in the pipeline and summarize progress in treatment of retinal degenerative disease.

Canine neurological diseases in a referral hospital population between 1989 and 2000 in Switzerland

OBJECTIVES: To merge clinical information from partly overlapping medical record databases of the Small Animal Teaching Hospital of the Vetsuisse Faculty, University of Berne. To describe the frequencies and localisations of neurological diseases in dogs, as well as their age, gender, breed and geographical distributions. METHODS: In this retrospective study, a new database, with specific variables and a diagnosis key list 'VITAMIN D', was created and defined. A total of 4497 dogs (average of 375 per year) with a well-documented neurological disease were included in the study. A key list for the diagnoses was developed and applied to either the presumptive or the clinical and neurohistopathological diagnosis, with a serial number, a code for localisation and a code for differential diagnoses. RESULTS: Approximately 1159 dogs (26 per cent) had a neurohistopathological diagnosis confirmed, 1431 (32 per cent) had a clinical diagnosis confirmed and 1491 (33 per cent) had a presumptive diagnosis. The most frequent breeds were mixed-breed dogs (577 of 4497, 13 per cent), followed by German shepherd dogs (466 of 4497, 10 per cent). The most common localisations were the forebrain (908 of 4497, 20 per cent) and the spinal cord at the thoracolumbar area (840 of 4497, 19 per cent). Most dogs were diagnosed with degenerative diseases (38 per cent), followed by inflammatory/infectious diseases (14 per cent). The highest number of submissions originated from geographic regions around the referral hospital and from regions with higher human population densities. CLINICAL SIGNIFICANCE: By defining closed-list fields and allocating all data to the corresponding fields, a standardised database that can be used for further studies was generated. The analysis of this study gives examples of the possible uses of a standardised database.

Intraoperative determination of the load-displacement behavior of scoliotic spinal motion segments: preliminary clinical results

Introduction: Spinal fusion is a widely and successfully performed strategy for the treatment of spinal deformities and degenerative diseases. The general approach has been to stabilize the spine with implants so that a solid bony fusion between the vertebrae can develop. However, new implant designs have emerged that aim at preservation or restoration of the motion of the spinal segment. In addition to static, load sharing principles, these designs also require a profound knowledge of kinematic and dynamic properties to properly characterise the in vivo performance of the implants. Methods: To address this, an apparatus was developed that enables the intraoperative determination of the load–displacement behavior of spinal motion segments. The apparatus consists of a sensor-equipped distractor to measure the applied force between the transverse processes, and an optoelectronic camera to track the motion of vertebrae and the distractor. In this intraoperative trial, measurements from two patients with adolescent idiopathic scoliosis with right thoracic curves were made at four motion segments each. Results: At a lateral bending moment of 5 N m, the mean flexibility of all eight motion segments was 0.18 ± 0.08°/N m on the convex side and 0.24 ± 0.11°/N m on the concave side. Discussion: The results agree with published data obtained from cadaver studies with and without axial preload. Intraoperatively acquired data with this method may serve as an input for mathematical models and contribute to the development of new implants and treatment strategies.

Development of a morphometric magnetic resonance image parameter suitable for distinguishing between normal dogs and dogs with cerebellar atrophy

Neurodegenerative diseases affect the cerebellum of numerous dog breeds. Although subjective, magnetic resonance (MR) imaging has been used to detect cerebellar atrophy in these diseases, but there are few data available on the normal size range of the cerebellum relative to other brain regions. The purpose of this study was to determine whether the size of the cerebellum maintains a consistent ratio with other brain regions in different ages and breeds of normal dogs and to define a measurement that can be used to identify cerebellar atrophy on MR images. Images from 52 normal and 13 dogs with cerebellar degenerative diseases were obtained. Volume and mid-sagittal cross-sectional area of the forebrain, brainstem, and cerebellum were calculated for each normal dog and compared between different breeds and ages as absolute and relative values. The ratio of the cerebellum to total brain and of the brainstem to cerebellum mid-sagittal cross-sectional area was compared between normal and affected dogs and the sensitivity and specificity of these ratios at distinguishing normal from affected dogs was calculated. The percentage of the brain occupied by the cerebellum in diverse dog breeds between 1 and 5 years of age was not significantly different, and cerebellar size did not change with increasing age. Using a cut off of 89%, the ratio between the brainstem and cerebellum mid-sagittal cross-sectional area could be used successfully to differentiate affected from unaffected dogs with a sensitivity and specificity of 100%, making this ratio an effective tool for identifying cerebellar atrophy on MR images.

gamma-tocopherol traps mutagenic electrophiles such as NO(X) and complements alpha-tocopherol: physiological implications

Peroxynitrite, a powerful mutagenic oxidant and nitrating species, is formed by the near diffusion-limited reaction of .NO and O2.- during activation of phagocytes. Chronic inflammation induced by phagocytes is a major contributor to cancer and other degenerative diseases. We examined how gamma-tocopherol (gammaT), the principal form of vitamin E in the United States diet, and alpha-tocopherol (alphaT), the major form in supplements, protect against peroxynitrite-induced lipid oxidation. Lipid hydroperoxide formation in liposomes (but not isolated low-density lipoprotein) exposed to peroxynitrite or the .NO and O2.- generator SIN-1 (3-morpholinosydnonimine) was inhibited more effectively by gammaT than alphaT. More importantly, nitration of gammaT at the nucleophilic 5-position, which proceeded in both liposomes and human low density lipoprotein at yields of approximately 50% and approximately 75%, respectively, was not affected by the presence of alphaT. These results suggest that despite alphaT's action as an antioxidant gammaT is required to effectively remove the peroxynitrite-derived nitrating species. We postulate that gammaT acts in vivo as a trap for membrane-soluble electrophilic nitrogen oxides and other electrophilic mutagens, forming stable carbon-centered adducts through the nucleophilic 5-position, which is blocked in alphaT. Because large doses of dietary alphaT displace gammaT in plasma and other tissues, the current wisdom of vitamin E supplementation with primarily alphaT should be reconsidered.

The international spine registry SPINE TANGO: status quo and first results

With an official life time of over 5 years, Spine Tango can meanwhile be considered the first international spine registry. In this paper we present an overview of frequency statistics of Spine Tango for demonstrating the genesis of questionnaire development and the constantly increasing activity in the registry. Results from two exemplar studies serve for showing concepts of data analysis applied to a spine registry. Between 2002 and 2006, about 6,000 datasets were submitted by 25 centres. Descriptive analyses were performed for demographic, surgical and follow-up data of three generations of the Spine Tango surgery and follow-up forms. The two exemplar studies used multiple linear regression models to identify potential predictor variables for the occurrence of dura lesions in posterior spinal fusion, and to evaluate which covariates influenced the length of hospital stay. Over the study period there was a rise in median patient age from 52.3 to 58.6 years in the Spine Tango data pool and an increasing percentage of degenerative diseases as main pathology from 59.9 to 71.4%. Posterior decompression was the most frequent surgical measure. About one-third of all patients had documented follow-ups. The complication rate remained below 10%. The exemplar studies identified "centre of intervention" and "number of segments of fusion" as predictors of the occurrence of dura lesions in posterior spinal fusion surgery. Length of hospital stay among patients with posterior fusion was significantly influenced by "centre of intervention", "surgeon credentials", "number of segments of fusion", "age group" and "sex". Data analysis from Spine Tango is possible but complicated by the incompatibility of questionnaire generations 1 and 2 with the more recent generation 3. Although descriptive and also analytic studies at evidence level 2++ can be performed, findings cannot yet be generalised to any specific country or patient population. Current limitations of Spine Tango include the low number and short duration of follow-ups and the lack of sufficiently detailed patient data on subgroup levels. Although the number of participants is steadily growing, no country is yet represented with a sufficient number of hospitals. Nevertheless, the benefits of the project for the whole spine community become increasingly visible.

Oculopharyngeal muscular dystrophy - an under-diagnosed disorder?

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant muscle disorder, usually of late onset. OPMD is among the few triplet repeat diseases/ polyalanine (poly(A)) expansion diseases for which the function of the mutated gene is quite well established. The disease is characterised by slowly progressive bilateral ptosis, dysphagia and proximal limb weakness, appearing after the age of 40 years. Prevalence and incidence of OPMD are low, but the disease occurs all over the world. The pedigrees of two Swiss kindred have been previously reported in Switzerland. In the last 2 years, accumulation of newly diagnosed cases in North-West Switzerland have been observed, which suggests that OPMD may be more prevalent than previously thought. Primary care providers, opthalmologists and neurologists that are alert for the almost specific combination of clinical signs, together with the availability of reliable genetic testing may help to recognise currently undiagnosed patients. They can advance knowledge and the characterisation of the OPMD population in Switzerland. Since the number of disorders linked to poly(A) expansions is growing rapidly, the study of OPMD may contribute to the understanding of a large group of other developmental and degenerative diseases. On the basis of a patient with "classical" OPMD, this review summarises the clinical, therapeutic, epidemiological, pathomechanistic and genetic aspects of OPMD, provides practical information about the differential diagnosis of OPMD, and presents a survey of different investigational methods.

Cellular senescence of white blood cells in very long-term survivors after allogeneic hematopoietic stem cell transplantation: the role of chronic graft-versus-host disease and female donor sex

In this single-center, cross-sectional study, we evaluated 44 very long-term survivors with a median follow-up of 17.5 years (range, 11-26 years) after hematopoietic stem cell transplantation. We assessed the telomere length difference in human leukocyte antigen-identical donor and recipient sibling pairs and searched for its relationship with clinical factors. The telomere length (in kb, mean +/- SD) was significantly shorter in all recipient blood cells compared with their donors' blood cells (P < .01): granulocytes (6.5 +/- 0.9 vs 7.1 +/- 0.9), naive/memory T cells (5.7 +/- 1.2 vs 6.6 +/- 1.2; 5.2 +/- 1.0 vs 5.7 +/- 0.9), B cells (7.1 +/- 1.1 vs 7.8 +/- 1.1), and natural killer/natural killer T cells (4.8 +/- 1.0 vs 5.6 +/- 1.3). Chronic graft-versus-host disease (P < .04) and a female donor (P < .04) were associated with a greater difference in telomere length between donor and recipient. Critically short telomeres have been described in degenerative diseases and secondary malignancies. If this hypothesis can be confirmed, identification of recipients at risk for cellular senescence could become part of monitoring long-term survivors after hematopoietic stem cell transplantation.

The lifestyle of our kids (LOOK) project: outline of methods

This methods paper outlines the overall design of a community-based multidisciplinary longitudinal study with the intent to stimulate interest and communication from scientists and practitioners studying the role of physical activity in preventive medicine. In adults, lack of regular exercise is a major risk factor in the development of chronic degenerative diseases and is a major contributor to obesity, and now we have evidence that many of our children are not sufficiently active to prevent early symptoms of chronic disease. The lifestyle of our kids (LOOK) study investigates how early physical activity contributes to health and development, utilizing a longitudinal design and a cohort of eight hundred and thirty 7-8-year-old (grade 2) school children followed to age 11-12 years (grade 6), their average family income being very close to that of Australia. We will test two hypotheses, that (a) the quantity and quality of physical activity undertaken by primary school children will influence their psychological and physical health and development; (b) compared with existing practices in primary schools, a physical education program administered by visiting specialists will enhance health and development, and lead to a more positive perception of physical activity. To test the first hypothesis we will monitor all children longitudinally over the 4 years. To test the second we will involve an intervention group of 430 children who receive two 50min physical education classes every week from visiting specialists and a control group of 400 who continue with their usual primary school physical education with their class-room teachers. At the end of grades 2, 4, and 6 we will measure several areas of health and development including blood risk factors for chronic disease, cardiovascular structure and function, physical fitness, psychological characteristics and perceptions of physical activity, bone structure and strength, motor control, body composition, nutritional intake, influence of teachers and family, and academic performance.

Morphologic-anthropological investigations in tomb K93.12 at Dra’ Abu el-Naga (Western Thebes, Egypt)

In this study we present the analysis of the human remains from tomb K93.12 in the Ancient Egyptian necropolis of Dra’ Abu el-Naga, located opposite the modern city of Luxor in Upper Egypt on the western bank of the Nile. Archaeological findings indicate that the rock tomb was originally built in the early 18th dynasty. Remains of two tomb-temples of the 20th dynasty and the looted burial of the High Priest of Amun Amenhotep have been identified. After the New Kingdom the tomb was reused as a burial place until the 26th dynasty. The skeletal and mummified material of the different tomb areas underwent a detailed anthropological and paleopathological analysis. The human remains were mostly damaged and scattered due to extensive grave robberies. In total, 79 individuals could be partly reconstructed and investigated. The age and sex distribution revealed a male predominance and a high percentage of young children (< 6 years) and adults in the range of 20 to 40 years. The paleopathological analysis showed a high prevalence of stress markers such as cribra orbitalia in the younger individuals, and other pathological conditions such as dental diseases, degenerative diseases and a possible case of ankylosing spondylitis. Additionally, 13 mummies of an intrusive waste pit could be attributed to three different groups belonging to earlier time periods based on their style of mummification and materials used. The study revealed important information on the age and sex distribution and diseases of the individuals buried in tomb K93.12.

Caring for ageing migrants in nursing homes: 'doing diversity' while 'doing death'

The proposed paper will present first results of a research project investigating how nursing homes in Switzerland deal with migrant elders who are in intensive need of care. Focusing on the end-of-life in institutional care settings, the intention is to explore the dimensions of ‘doing death’ in Swiss nursing homes when the elderly involved are of migrant background. The focus is laid on the co-construction of end of life in interactions between residents of migrant background and professional carers involved (often of migrant background themselves), and will thereby focus on processes of ‘doing diversity’ while ‘doing death’. To do so, we chose an ethnographic approach focusing on the participant observation of everyday practices of ‘doing death’ and ‘death work’ and on interviewing staff, residents and their relatives. Caring for ageing migrants at the end of their lives is studied in different types of assisted living at the end of life: The field of research was entered by studying a group specific department for residents of so-called ‘Mediterranean’ background. It was contrasted by a department stressing the individuality of each resident but including a considerable number of residents with migrant background. We are interested in how (and if at all) specific forms of ‘doing community’ within different types of departments may also lead to specific ways of ‘doing death’, which aim at a stronger embeddedness of dying trajectories in social relations of reciprocity and exchange. Furthermore, migrant ‘doing death’ is expected to be particularly negotiable since the potential diversities of symbolic reference systems and daily practices are widened. If the respective resident is limited in his/her capacities to play an active part in negotiating about ‘good care’ and ‘good dying’ – either due to language competences, which would be migrant specific, or due to degenerative diseases, which is not migrant specific – the field of negotiations will be left up to the professionals within the organization (and to the relatives, which are, however, not constantly present). Strategies of stereotyping the ‘other’ as well as driving nurses, caring aides and other professionals of migrant background into roles of ‘cultural experts’ or ‘transcultural translators’ are expected to be common in such situations. However, the task of negotiating what would be a ‘good dying’ and what measures are appropriate is always at stake in contemporary heterogeneous societies. Therefore we would argue that studying dying processes involving migrant residents is looking at paradigmatic manifestations of doing death in recent contexts of reflexive modernity.

Methylnitrosourea (MNU)-induced retinal degeneration and regeneration in the zebrafish: histological and functional characteristics.

Retinal degenerative diseases, e.g. retinitis pigmentosa, with resulting photoreceptor damage account for the majority of vision loss in the industrial world. Animal models are of pivotal importance to study such diseases. In this regard the photoreceptor-specific toxin N-methyl-N-nitrosourea (MNU) has been widely used in rodents to pharmacologically induce retinal degeneration. Previously, we have established a MNU-induced retinal degeneration model in the zebrafish, another popular model system in visual research. A fascinating difference to mammals is the persistent neurogenesis in the adult zebrafish retina and its regeneration after damage. To quantify this observation we have employed visual acuity measurements in the adult zebrafish. Thereby, the optokinetic reflex was used to follow functional changes in non-anesthetized fish. This was supplemented with histology as well as immunohistochemical staining for apoptosis (TUNEL) and proliferation (PCNA) to correlate the developing morphological changes. In summary, apoptosis of photoreceptors occurs three days after MNU treatment, which is followed by a marked reduction of cells in the outer nuclear layer (ONL). Thereafter, proliferation of cells in the inner nuclear layer (INL) and ONL is observed. Herein, we reveal that not only a complete histological but also a functional regeneration occurs over a time course of 30 days. Now we illustrate the methods to quantify and follow up zebrafish retinal de- and regeneration using MNU in a video-format.

Necessary or unnecessary? a critical glance on spine surgery

Patients with complaints and symptoms caused by spinal degenerative diseases demonstrate a high rate of spontaneous improvement. Except of severe neurological symptoms such as high grade motor deficits, medically intractable pain and vegetative symptoms (cauda syndrome) operations require 1) symptoms, 2) a mechanical cause visible on imaging that sufficiently explains the symptoms, 3) a completed conservative treatment protocol performed over a 4) 6-12 week period. According to the evidence found in the literature, patients with lumbar disk herniation significantly benefit from surgery by a faster relieve of pain and return to social and professional activity, however, the results are converging after a period of 1-2 years. Surgery of lumbar spinal stenosis is considered a gold standard and superior to conservative care when symptoms are severe and leg pain is present. Bilateral microsurgical decompression using a bilateral or a unilateral approach with over-the-top decompression of the contralateral nerve root are superior to laminectomy as the decompression procedure. Lumbar fusion is only indicated in patients with spinal stenosis when a major or mobile spondylolisthesis is diagnosed. There is no indication of prophylactic surgery to avoid a "dangerous" deficit that might develop in the future.

Retinal differentiation of human bone marrow-derived stem cells by co-culture with retinal pigment epithelium in vitro.

The goal of this study was to assess the in vitro differentiation capacity of human bone marrow-derived stem cells (hBMSCs) along retinal lineages. Mononuclear cells (MNC) were isolated from bone marrow (BM) and mobilized peripheral blood (mPB) using Ficoll-Paque density gradient centrifugation, and were sorted by magnetic-activated cell sorting (MACS) for specific stem cell subsets (CD34(+)CD38(+)/CD34(+)CD38(-)). These cells were then co-cultured on human retinal pigment epithelial cells (hRPE) for 7 days. The expression of stem cell, neural and retina-specific markers was examined by immunostaining, and the gene expression profiles were assessed after FACS separation of the co-cultured hBMSCs by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, in vitro functionality of the differentiated cells was analyzed by quantifying phagocytosis of CY5-labeled photoreceptor outer segments (POS). After 7 days of co-culture, hBMSCs adopted an elongated epithelial-like morphology and expressed RPE-specific markers, such as RPE65 and bestrophin. In addition, these differentiated cells were able to phagocytose OS, one of the main characteristics of native RPE cells. Our data demonstrated that human CD34(+)CD38(-) hBMSC may differentiate towards an RPE-like cell type in vitro and could become a new type of autologous donor cell for regenerative therapy in retinal degenerative diseases.