Feasibility of a novel eHealth intervention for Parkinson's disease targeting motor-cognitive function in the home

BACKGROUND

Parkinson's disease (PD) drastically affects motor and cognitive function, but evidence shows that motor-cognitive training improves disease symptoms. Motor-cognitive training in the home is scarcely investigated and eHealth methods can provide continual support for PD self-management. Feasibility testing is however required.

OBJECTIVE

To assess the feasibility (i) Recruitment capability (ii) Acceptability and Suitability (iii) Demand and Safety of a home-based motor-cognitive eHealth exercise intervention in PD.

METHODS

The 10-week intervention was delivered using the ExorLive® application and exercises were individually adapted and systematically progressed and targeted functional strength, cardiovascular fitness, flexibility, and motor-cognitive function. People with mild-to moderate PD were assessed before and after the intervention regarding; gait performance in single and dual-task conditions; functional mobility; dual-task performance; balance performance; physical activity level; health related quality of life and perceived balance confidence and walking ability; global cognition and executive function. Feasibility outcomes were continuously measured using a home-exercise diary and contact with a physiotherapist. Changes from pre- and post-intervention are reported descriptively.

RESULTS

Fifteen participants (mean age 68.5 years) commenced and 14 completed the 10-week intervention. In relation to intervention Acceptability, 64% of the motor sessions and 52% of motor-cognitive sessions were rated as "enjoyable". Concerning Suitability, the average level of exertion (Borg RPE scale) was light (11-12). Adherence was high, with 86% of all (420) sessions reported as completed. No falls or other adverse events occurred in conjunction with the intervention.

CONCLUSIONS

This motor-cognitive eHealth home exercise intervention for PD was safe and feasible in terms of Recruitment capability, Acceptability, Safety and Demand. The intensity of physical challenge needs to be increased before testing in an efficacy trial.

TRIAL REGISTRATION

This trial is registered at Clinicaltrials.gov (NCT05027620).

Make My Day: primary prevention of stroke using engaging everyday activities as a mediator of sustainable health - a randomised controlled trial and process evaluation protocol

INTRODUCTION

The individual, societal and economic benefits of stroke prevention are high. Even though most risk factors can be reduced by changes to lifestyle habits, maintaining new and healthy activity patterns has been shown to be challenging.The aim of the study is to evaluate the impact of an interdisciplinary team-based, mHealth-supported prevention intervention on persons at risk for stroke. The intervention is mediated by engaging everyday activities that promote health. An additional aim is to describe a process evaluation that serves to increase knowledge about how the programme leads to potential change by studying the implementation process and mechanisms of impact.

METHODS AND ANALYSIS

The study will be a randomised controlled trial including 104 persons at risk for stroke. Persons at risk of stroke (n=52) will be randomised to an mHealth-supported stroke prevention programme. Controls will have ordinary primary healthcare (PHC) services. The 10-week programme will be conducted at PHC clinics, combining group meetings and online resources to support self-management of lifestyle change using engaging everyday activities as a mediator. Primary outcomes are stroke risk, lifestyle habits and participation in health-promoting activities. Assessments will be performed at baseline and at follow-up (11 weeks and 12 months). The effects of the programme will be analysed using inferential statistics. Implementation will be analysed using qualitative and quantitative methods.

ETHICS AND DISSEMINATION

The study has been approved by the Swedish Ethical Review Authority. Study results will be disseminated in peer-reviewed journals and at regional and international conferences targeting mixed audiences.

TRIAL REGISTRATION NUMBER

NCT05279508.

Design of the STEPS trial: a phase II randomized controlled trial evaluating eHealth-supported motor-cognitive home training for Parkinson's disease

BACKGROUND

Electronic health (eHealth) technology offers the potential to support and motivate physical activity for symptom management in Parkinson's disease (PD). It is also recommended that motor exercise in PD be complemented with cognitive training aimed at attentional or executive functions. This paper describes the protocol for a double-blind randomized controlled trial to evaluate the effects of motor-cognitive training in the home environment, supported by eHealth.

METHODS/DESIGN

The Support for home Training using Ehealth in Parkinsons diseaSe (STEPS) is a double-blind single center randomized controlled trial. Two parallel groups will include in total 120 participants with mild to moderate PD who will receive either (i) the intervention (a progressive 10-week individualized motor-cognitive eHealth training with cognitive behavioral elements to increase physical activity levels) or (ii) an active control group (an individualized 10-week paper-based home exercise program). The active control group will not receive motor-cognitive exercises or cognitive behavioral approaches to increase physical activity level. The primary outcome is walking capacity assessed by the six-minute walk test (6MWT). Secondary outcomes will include gait performance during single and dual task conditions, gait speed, functional mobility and lower limb strength, balance, physical activity behavior and a range of patient reported outcome measures relevant in PD.

DISCUSSION

The STEPS trial will answer the question whether 10 weeks of eHealth supported motor-cognitive exercise in the home environment can improve walking capacity in PD when compared to a standard paper exercise program. Findings from this study will also strengthen the evidence concerning the efficacy of PD-specific eHealth interventions with a view meeting future health care demands by addressing issues of inaccessibility to specialized neurological rehabilitation in PD.

TRIAL REGISTRATION

ClinicalTrials.gov August 2022, NCT05510739.

The Feasibility of Make My Day-A Randomized Controlled Pilot Trial of a Stroke Prevention Program in Primary Healthcare

Incorporating and sustaining engaging everyday activities (EEAs) in everyday life holds potential for improving health and wellbeing; thus, there is reason to explore EEAs as a behavioral change technique in stroke prevention. The aim of this study was to evaluate the feasibility of the stroke prevention program Make My Day (MMD) for people with moderate-to-high risk for stroke in a primary healthcare setting, where EEAs are utilized to promote healthy activity patterns. A randomized controlled pilot trial was designed to evaluate the feasibility of MMD. Twenty-nine persons at risk for stroke were recruited and randomized into either an intervention group (n = 14) receiving MMD or a control group (n = 15) receiving brief health advice and support with goal setting. The results suggest that MMD is feasible, with timely recruitment, overall high response rates and study completion, and sensitivity to change in key outcome measures. Moreover, the results demonstrate that the application of EEAs can be useful for promoting behavioral change in stroke prevention. Recommendations for improvements for a full-scale trial include recruiting a relevant sample, using reliability- and validity-tested outcome measures, and implementing strategies to limit missing data.

Temporal trends in hospitalizations and 30-day mortality in older patients during the COVID pandemic from March 2020 to July 2021

BACKGROUND

A reduction in mortality risk of COVID-19 throughout the first wave of the pandemic has been reported, but less is known about later waves. This study aimed to describe changes in hospitalizations and mortality of patients receiving inpatient geriatric care for COVID-19 or other causes during the pandemic.

METHODS

Patients 70 years and older hospitalized in geriatric hospitals in Stockholm for COVID-19 or other causes between March 2020-July 2021 were included. Data on the incidence of COVID-positive cases and 30-day mortality of the total ≥ 70-year-old population, in relation to weekly hospitalizations and mortality after hospital admissions were analyzed. Findings The total number of hospitalizations was 5,320 for COVID-19 and 32,243 for non-COVID-cases. In COVID-patients, the 30-day mortality rate was highest at the beginning of the first wave (29% in March-April 2020), reached 17% at the second wave peak (November-December) followed by 11-13% in the third wave (March-July 2021). The mortality in non-COVID geriatric patients showed a similar trend, but of lower magnitude (5-10%). During the incidence peaks, COVID-19 hospitalizations displaced non-COVID geriatric patients.

INTERPRETATION

Hospital admissions and 30-day mortality after hospitalizations for COVID-19 increased in periods of high community transmission, albeit with decreasing mortality rates from wave 1 to 3, with a probable vaccination effect in wave 3. Thus, the healthcare system could not compensate for the high community spread of COVID-19 during the pandemic peaks, which also led to displacing care for non-COVID geriatric patients.

Orofacial dysfunction after stroke-A multidisciplinary approach

OBJECTIVE

This paper describes the study protocol in an ongoing clinical trial evaluating oral screen training as part of a post-stroke rehabilitation programme. Baseline data were related to four domains: dysphagia, lip function, masticatory performance and patient-related outcome measures (PROM).

BACKGROUND

Stroke is one of the most common causes of disability-adjusted life years, and dysphagia is a common remaining problem after stroke. Rehabilitation using oral screen training has been suggested to improve swallowing, but evidence is still insufficient.

MATERIALS AND METHODS

Patients diagnosed with stroke with persisting objective and/or subjective swallowing dysfunction after primary rehabilitation were assessed for eligibility. In total, 25 patients were included. Objective function was assessed by swallowing capacity test (SCT), lip force and masticatory performance, subjective function by EAT-10 and NOT-S and PROM by LiSat-11 and ESAS.

RESULTS

Baseline data presented a heterogeneous pattern with no significant association between objective and subjective dysfunction. Most of the participants (20/25) showed impaired swallowing capacity in SCT, and 23/24 revealed orofacial dysfunction according to NOT-S. The most common subjective item reported was chewing and swallowing problems (19/24).

CONCLUSION

The heterogenous findings in the included tests and the lack of correlations emphasise the importance of multidisciplinary approaches to identify objective and subjective orofacial post-stroke dysfunction in clinical practice to be able to offer evidence-based individualised care. The included participants were representative of stroke patients with dysphagia, which supports proceeding with the planned intervention.

Profiling spatiotemporal gene expression of the developing human spinal cord and implications for ependymoma origin

The spatiotemporal regulation of cell fate specification in the human developing spinal cord remains largely unknown. In this study, by performing integrated analysis of single-cell and spatial multi-omics data, we used 16 prenatal human samples to create a comprehensive developmental cell atlas of the spinal cord during post-conceptional weeks 5-12. This revealed how the cell fate commitment of neural progenitor cells and their spatial positioning are spatiotemporally regulated by specific gene sets. We identified unique events in human spinal cord development relative to rodents, including earlier quiescence of active neural stem cells, differential regulation of cell differentiation and distinct spatiotemporal genetic regulation of cell fate choices. In addition, by integrating our atlas with pediatric ependymomas data, we identified specific molecular signatures and lineage-specific genes of cancer stem cells during progression. Thus, we delineate spatiotemporal genetic regulation of human spinal cord development and leverage these data to gain disease insight.

Return to work after COVID-19: Experiences and expectations from the first wave of COVID-19 in Stockholm

BACKGROUND

In Stockholm (Sweden) a substantial number of persons who were infected with SARS-CoV-2 during spring 2020, and received intensive care followed by rehabilitation due to COVID-19, were of working age. For this group, return to work (RTW) is an important part of the rehabilitation, however this is an area that thus far has received little scholarly attention. The Aim of this study was two-fold. First, to descriptively look at self-reported work ability over time using the Work Abilty Index among working age adults who recovered from severe COVID-19, and secondly, to explore experiences and expectations concerning RTW among working age adults who recovered from severe COVID-19.

METHODS

Focus group interviews and qualitative thematic analyses were utilized. In addition, the study populations' self-reported work ability index was recorded over one year.

FINDINGS

Qualitative analysis of data resulted in 5 themes: a) Initial experiences after discharge from in-patient rehabilitation, b) Disparate first contact with work, c) Uncertainties about own role in RTW process, d) Working situation for those who had started getting back to work, and e) A need to reprioritize expectations for work in the context of everyday life. There were no statistical differences in work ability index scores between 18 and 52 weeks after discharge from an in-patient rehabilitation unit.

CONCLUSION

RTW after COVID-19 can require systematic support for several months as well as be initiated earlier in the rehabilitation process. Further research in the area is needed.

Body mass index and Mini Nutritional Assessment-Short Form as predictors of in-geriatric hospital mortality in older adults with COVID-19

BACKGROUND & AIMS

Overweight and obesity have been consistently reported to carry an increased risk for poorer outcomes in coronavirus disease 2019 (COVID-19) in adults. Existing reports mainly focus on in-hospital and intensive care unit mortality in patient cohorts usually not representative of the population with the highest mortality, i.e. the very old and frail patients. Accordingly, little is known about the risk patterns related to body mass and nutrition in very old patients. Our aim was to assess the relationship between body mass index (BMI), nutritional status and in-geriatric hospital mortality among geriatric patients treated for COVID-19. As a reference, the analyses were performed also in patients treated for other diagnoses than COVID-19.

METHODS

We analyzed up to 10,031 geriatric patients with a median age of 83 years of which 1409 (14%) were hospitalized for COVID-19 and 8622 (86%) for other diagnoses in seven geriatric hospitals in the Stockholm region, Sweden during March 2020-January 2021. Data were available in electronic hospital records. The associations between 1) BMI and 2) nutritional status, assessed using the Mini-Nutritional Assessment - Short Form (MNA-SF) scale, and short-term in-geriatric hospital mortality were analyzed using logistic regression.

RESULTS

After adjusting for age, sex, comorbidity, polypharmacy, frailty and the wave of the pandemic (first vs. second), underweight defined as BMI<18.5 increased the risk of in-hospital mortality in COVID-19 patients (odds ratio [OR] = 2.30; confidence interval [CI] = 1.17-4.31). Overweight and obesity were not associated with in-hospital mortality. Malnutrition; i.e. MNA-SF 0-7 points, increased the risk of in-hospital mortality in patients treated for COVID-19 (OR = 2.03; CI = 1.16-3.68) and other causes (OR = 6.01; CI = 2.73-15.91).

CONCLUSIONS

Our results indicate that obesity is not a risk factor for very old patients with COVID-19, but emphasize the role of underweight and malnutrition for in-hospital mortality in geriatric patients with COVID-19.

Two Years with COVID-19: The Electronic Frailty Index Identifies High-Risk Patients in the Stockholm GeroCovid Study

<b><i>Introduction:</i></b> Frailty, a measure of biological aging, has been linked to worse COVID-19 outcomes. However, as the mortality differs across the COVID-19 waves, it is less clear whether a medical record-based electronic frailty index (eFI) that we have previously developed for older adults could be used for risk stratification in hospitalized COVID-19 patients. <b><i>Objectives:</i></b> The aim of the study was to examine the association of frailty with mortality, readmission, and length of stay in older COVID-19 patients and to compare the predictive accuracy of the eFI to other frailty and comorbidity measures. <b><i>Methods:</i></b> This was a retrospective cohort study using electronic health records (EHRs) from nine geriatric clinics in Stockholm, Sweden, comprising 3,980 COVID-19 patients (mean age 81.6 years) admitted between March 2020 and March 2022. Frailty was assessed using a 48-item eFI developed for Swedish geriatric patients, the Clinical Frailty Scale, and the Hospital Frailty Risk Score. Comorbidity was measured using the Charlson Comorbidity Index. We analyzed in-hospital mortality and 30-day readmission using logistic regression, 30-day and 6-month mortality using Cox regression, and the length of stay using linear regression. Predictive accuracy of the logistic regression and Cox models was evaluated by area under the receiver operating characteristic curve (AUC) and Harrell’s C-statistic, respectively. <b><i>Results:</i></b> Across the study period, the in-hospital mortality rate decreased from 13.9% in the first wave to 3.6% in the latest (Omicron) wave. Controlling for age and sex, a 10% increment in the eFI was significantly associated with higher risks of in-hospital mortality (odds ratio = 2.95; 95% confidence interval = 2.42–3.62), 30-day mortality (hazard ratio [HR] = 2.39; 2.08–2.74), 6-month mortality (HR = 2.29; 2.04–2.56), and a longer length of stay (β-coefficient = 2.00; 1.65–2.34) but not with 30-day readmission. The association between the eFI and in-hospital mortality remained robust across the waves, even after the vaccination rollout. Among all measures, the eFI had the best discrimination for in-hospital (AUC = 0.780), 30-day (Harrell’s C = 0.733), and 6-month mortality (Harrell’s C = 0.719). <b><i>Conclusion:</i></b> An eFI based on routinely collected EHRs can be applied in identifying high-risk older COVID-19 patients during the continuing pandemic.

Development of an electronic frailty index for hospitalized older adults in Sweden

BACKGROUND

Frailty assessment in the Swedish health system relies on the Clinical Frailty Scale (CFS), but it requires training, in-person evaluation, and is often missing in medical records. We aimed to develop an electronic frailty index (eFI) from routinely collected electronic health records (EHRs) and assess its association with adverse outcomes in hospitalized older adults.

METHODS

EHRs were extracted for 18,225 patients with unplanned admissions between 1 March 2020 and 17 June 2021 from nine geriatric clinics in Stockholm, Sweden. A 48-item eFI was constructed using diagnostic codes, functioning and other health indicators, and laboratory data. The CFS, Hospital Frailty Risk Score, and Charlson Comorbidity Index were used for comparative assessment of the eFI. We modelled in-hospital mortality and 30-day readmission using logistic regression; 30-day and 6-month mortality using Cox regression; and length of stay using linear regression.

RESULTS

13,188 patients were included in analyses (mean age 83.1 years). A 0.03 increment in the eFI was associated with higher risks of in-hospital (odds ratio: 1.65; 95% confidence interval: 1.54-1.78), 30-day (hazard ratio [HR]: 1.43; 1.38-1.48), and 6-month mortality (HR: 1.34; 1.31-1.37) adjusted for age and sex. Of the frailty and comorbidity measures, the eFI had the highest area under receiver operating characteristic curve for in-hospital mortality of 0.813. Higher eFI was associated with longer length of stay, but had a rather poor discrimination for 30-day readmission.

CONCLUSIONS

An EHR-based eFI has robust associations with adverse outcomes, suggesting that it can be used in risk stratification in hospitalized older adults.

Self-organising human gonads generated by a Matrigel-based gradient system

BACKGROUND

Advances in three-dimensional culture technologies have led to progression in systems used to model the gonadal microenvironment in vitro. Despite demonstrating basic functionality, tissue organisation is often limited. We have previously detailed a three-dimensional culture model termed the three-layer gradient system to generate rat testicular organoids in vitro. Here we extend the model to human first-trimester embryonic gonadal tissue.

RESULTS

Testicular cell suspensions reorganised into testis-like organoids with distinct seminiferous-like cords situated within an interstitial environment after 7 days. In contrast, tissue reorganisation failed to occur when mesonephros, which promotes testicular development in vivo, was included in the tissue digest. Organoids generated from dissociated female gonad cell suspensions formed loosely organised cords after 7 days. In addition to displaying testis-specific architecture, testis-like organoids demonstrated evidence of somatic cell differentiation. Within the 3-LGS, we observed the onset of AMH expression in the cytoplasm of SOX9-positive Sertoli cells within reorganised testicular cords. Leydig cell differentiation and onset of steroidogenic capacity was also revealed in the 3-LGS through the expression of key steroidogenic enzymes StAR and CYP17A1 within the interstitial compartment. While the 3-LGS generates a somatic cell environment capable of supporting germ cell survival in ovarian organoids germ cell loss was observed in testicular organoids.

CONCLUSION

The 3-LGS can be used to generate organised whole gonadal organoids within 7 days. The 3-LGS brings a new opportunity to explore gonadal organogenesis and contributes to the development of more complex in vitro models in the field of developmental and regenerative medicine.

Decreased Mortality Over Time During the First Wave in Patients With COVID-19 in Geriatric Care: Data From the Stockholm GeroCovid Study

OBJECTIVE

To describe temporal changes in treatment, care, and short-term mortality outcomes of geriatric patients during the first wave of the COVID-19 pandemic.

DESIGN

Observational study.

SETTING AND PARTICIPANTS

Altogether 1785 patients diagnosed with COVID-19 and 6744 hospitalized for non-COVID-19 causes at 7 geriatric clinics in Stockholm from March 6 to July 31, 2020, were included.

METHODS

Across admission month, patient vital signs and pharmacological treatment in relationship to risk for in-hospital death were analyzed using the Poisson regression model. Incidence rates (IRs) and incidence rate ratios (IRRs) of death are presented.

RESULTS

In patients with COVID-19, the IR of mortality were 27%, 17%, 10%, 8%, and 2% from March to July, respectively, after standardization for demographics and vital signs. Compared with patients admitted in March, the risk of in-hospital death decreased by 29% [IRR 0.71, 95% confidence interval (CI) 0.51-0.99] in April, 61% (0.39, 0.26-0.58) in May, 68% (0.32, 0.19-0.55) in June, and 86% (0.14, 0.03-0.58) in July. The proportion of patients admitted for geriatric care with oxygen saturation <90% decreased from 13% to 1%, which partly explains the improvement of COVID-19 patient survival. In non-COVID-19 patients during the pandemic, mortality rates remained relatively stable (IR 1.3%-2.3%). Compared with non-COVID-19 geriatric patients, the IRR of death declined from 11 times higher (IRR 11.7, 95% CI 6.11-22.3) to 1.6 times (2.61, 0.50-13.7) between March and July in patients with COVID-19.

CONCLUSIONS AND IMPLICATIONS

Mortality risk in geriatric patients from the Stockholm region declined over time throughout the first pandemic wave of COVID-19. The improved survival rate over time was only partly related to improvement in saturation status at the admission of the patients hospitalized later throughout the pandemic. Lower incidence during the later months could have led to less severe hospitalized cases driving down mortality.

In Vitro Study of Human Immune Responses to Hyaluronic Acid Hydrogels, Recombinant Spidroins and Human Neural Progenitor Cells of Relevance to Spinal Cord Injury Repair

Scaffolds of recombinant spider silk protein (spidroin) and hyaluronic acid (HA) hydrogel hold promise in combination with cell therapy for spinal cord injury. However, little is known concerning the human immune response to these biomaterials and grafted human neural stem/progenitor cells (hNPCs). Here, we analyzed short- and long-term in vitro activation of immune cells in human peripheral blood mononuclear cells (hPBMCs) cultured with/without recombinant spidroins, HA hydrogels, and/or allogeneic hNPCs to assess potential host-donor interactions. Viability, proliferation and phenotype of hPBMCs were analyzed using NucleoCounter and flow cytometry. hPBMC viability was confirmed after exposure to the different biomaterials. Short-term (15 h) co-cultures of hPBMCs with spidroins, but not with HA hydrogel, resulted in a significant increase in the proportion of activated CD69+ CD4+ T cells, CD8+ T cells, B cells and NK cells, which likely was caused by residual endotoxins from the Escherichia coli expression system. The observed spidroin-induced hPBMC activation was not altered by hNPCs. It is resource-effective to evaluate human compatibility of novel biomaterials early in development of the production process to, when necessary, make alterations to minimize rejection risk. Here, we present a method to evaluate biomaterials and hPBMC compatibility in conjunction with allogeneic human cells.

'Weaving lifestyle habits': Complex pathways to health for persons at risk for stroke

BACKGROUND

It is important to understand how healthy lifestyle habits can be developed as they are essential in cardiovascular disease (CVD) prevention. There is limited knowledge regarding whether, and how, engaging occupations (things that people do and occupy themselves with) can promote and help sustain healthy lifestyle habits for persons at risk for CVDs, including stroke.

AIM

The aim was to develop knowledge of how engaging in occupations can contribute to changes in lifestyle habits among persons at risk for stroke.

METHODS

Six adults presenting with stroke risk factors were interviewed on several occasions after participating in an occupation-focused stroke prevention programme. Grounded theory was utilised, and constant comparative methods guided the analysis.

FINDINGS

Changing lifestyle habits was perceived as a complex process, much like weaving a fabric with many parallel and interlacing threads. Literacy of both health and occupations and participation in engaging occupations were important facilitators for promoting healthy lifestyle habits, yet engagement in health-promoting occupations was described as conditioned behaviour.

CONCLUSIONS

CVD prevention programmes can benefit from incorporating engaging occupations to promote healthy lifestyle habits and literacy of health and occupations. However, contextual factors conditioning health and occupations should be considered when developing and implementing sustainable interventions.

Transplantation of Human Neural Precursor Cells Reverses Syrinx Growth in a Rat Model of Post-Traumatic Syringomyelia

Posttraumatic syringomyelia (PTS) is a serious condition of progressive expansion of spinal cord cysts, affecting patients with spinal cord injury years after injury. To evaluate neural cell therapy to prevent cyst expansion and potentially replace lost neurons, we developed a rat model of PTS. We combined contusive trauma with subarachnoid injections of blood, causing tethering of the spinal cord to the surrounding vertebrae, resulting in chronically expanding cysts. The cysts were usually located rostral to the injury, extracanalicular, lined by astrocytes. T2*-weighted magnetic resonance imaging (MRI) showed hyperintense fluid-filled cysts but also hypointense signals from debris and iron-laden macrophages/microglia. Two types of human neural stem/progenitor cells-fetal neural precursor cells (hNPCs) and neuroepithelial-like stem cells (hNESCs) derived from induced pluripotent stem cells-were transplanted to PTS cysts. Cells transplanted into cysts 10 weeks after injury survived at least 10 weeks, migrated into the surrounding parenchyma, but did not differentiate during this period. The cysts were partially obliterated by the cells, and cyst walls often merged with thin layers of cells in between. Cyst volume measurements with MRI showed that the volumes continued to expand in sham-transplanted rats by 102%, while the cyst expansion was effectively prevented by hNPCs and hNESCs transplantation, reducing the cyst volumes by 18.8% and 46.8%, respectively. The volume reductions far exceeded the volume of the added human cells. Thus, in an animal model closely mimicking the clinical situation, we provide proof-of-principle that transplantation of human neural stem/progenitor cells can be used as treatment for PTS.

Spermatogonia Loss Correlates with LAMA 1 Expression in Human Prepubertal Testes Stored for Fertility Preservation

Fertility preservation for male childhood cancer survivors not yet capable of producing mature spermatozoa, relies on experimental approaches such as testicular explant culture. Although the first steps in somatic maturation can be observed in human testicular explant cultures, germ cell depletion is a common obstacle. Hence, understanding the spermatogonial stem cell (SSC) niche environment and in particular, specific components such as the seminiferous basement membrane (BM) will allow progression of testicular explant cultures. Here, we revealed that the seminiferous BM is established from 6 weeks post conception with the expression of laminin alpha 1 (LAMA 1) and type IV collagen, which persist as key components throughout development. With prepubertal testicular explant culture we found that seminiferous LAMA 1 expression is disrupted and depleted with culture time correlating with germ cell loss. These findings highlight the importance of LAMA 1 for the human SSC niche and its sensitivity to culture conditions.

A qualitative study-Patient experience of tactile massage after stroke

Aim

The aim was to evaluate emotional experiences of gentle skin massage, combined with regular rehabilitation in patients shortly after being diagnosed with stroke.

Design

A randomized study with two groups: standard individualized rehabilitation and tactile massage for 20 min three times per week (max nine times) or individual standardized rehabilitations.

Methods

This study applied a qualitative approach using semi-structured questions to evaluate experiences of receiving tactile massage among patients with first-time-ever stroke. The interviews lasted between 6-25 min and analysed using manifest content analysis. Data was collected between 2015-2017. This study applies to the COREQ checklist.

Results

Eight patients >18 years of age participated. The participants experienced emotional worries especially during the night hours affecting their sleep negatively. Receiving tactile massage was reported to relax and to ease worries and anxiety momentarily, during the session and for a longer period. The results also show that physical touch generates feelings of closeness. The findings will be presented in two categories: Human touch and The future.

Human ex vivo spinal cord slice culture as a useful model of neural development, lesion, and allogeneic neural cell therapy

Background

There are multiple promising treatment strategies for central nervous system trauma and disease. However, to develop clinically potent and safe treatments, models of human-specific conditions are needed to complement in vitro and in vivo animal model-based studies.

Methods

We established human brain stem and spinal cord (cross- and longitudinal sections) organotypic cultures (hOCs) from first trimester tissues after informed consent by donor and ethical approval by the Regional Human Ethics Committee, Stockholm (lately referred to as Swedish Ethical Review Authority), and The National Board of Health and Welfare, Sweden. We evaluated the stability of hOCs with a semi-quantitative hOC score, immunohistochemistry, flow cytometry, Ca²⁺ signaling, and electrophysiological analysis. We also applied experimental allogeneic human neural cell therapy after injury in the ex vivo spinal cord slices.

Results

The spinal cord hOCs presented relatively stable features during 7–21 days in vitro (DIV) (except a slightly increased cell proliferation and activated glial response). After contusion injury performed at 7 DIV, a significant reduction of the hOC score, increase of the activated caspase-3⁺ cell population, and activated microglial populations at 14 days postinjury compared to sham controls were observed. Such elevation in the activated caspase-3⁺ population and activated microglial population was not observed after allogeneic human neural cell therapy.

Conclusions

We conclude that human spinal cord slice cultures have potential for future structural and functional studies of human spinal cord development, injury, and treatment strategies.

A Spatiotemporal Organ-Wide Gene Expression and Cell Atlas of the Developing Human Heart

The process of cardiac morphogenesis in humans is incompletely understood. Its full characterization requires a deep exploration of the organ-wide orchestration of gene expression with a single-cell spatial resolution. Here, we present a molecular approach that reveals the comprehensive transcriptional landscape of cell types populating the embryonic heart at three developmental stages and that maps cell-type-specific gene expression to specific anatomical domains. Spatial transcriptomics identified unique gene profiles that correspond to distinct anatomical regions in each developmental stage. Human embryonic cardiac cell types identified by single-cell RNA sequencing confirmed and enriched the spatial annotation of embryonic cardiac gene expression. In situ sequencing was then used to refine these results and create a spatial subcellular map for the three developmental phases. Finally, we generated a publicly available web resource of the human developing heart to facilitate future studies on human cardiogenesis.

Characterization of molecular mechanisms underlying the axonal Charcot-Marie-Tooth neuropathy caused by MORC2 mutations

Mutations in MORC2 lead to an axonal form of Charcot-Marie-Tooth (CMT) neuropathy type 2Z. To date, 31 families have been described with mutations in MORC2, indicating that this gene is frequently involved in axonal CMT cases. While the genetic data clearly establish the causative role of MORC2 in CMT2Z, the impact of its mutations on neuronal biology and their phenotypic consequences in patients remains to be clarified. We show that the full-length form of MORC2 is highly expressed in both embryonic and adult human neural tissues and that Morc2 expression is dynamically regulated in both the developing and the maturing murine nervous system. To determine the effect of the most common MORC2 mutations, p.S87L and p.R252W, we used several in vitro cell culture paradigms. Both mutations induced transcriptional changes in patient-derived fibroblasts and when expressed in rodent sensory neurons. These changes were more pronounced and accompanied by abnormal axonal morphology, in neurons expressing the MORC2 p.S87L mutation, which is associated with a more severe clinical phenotype. These data provide insight into the neuronal specificity of the mutated MORC2-mediated phenotype and highlight the importance of neuronal cell models to study the pathophysiology of CMT2Z.

Translation and validation of two International Spinal Cord Injury (SCI) Data Sets-a modified process

Study design

A descriptive design was used of a reflective process of problem solving among individuals working together to improve the process of translating.

Setting

Sweden.

Objectives

The aim of this study was to describe a modified process for translation and validation of the International Spinal Cord Injury (SCI) Quality of Life (QoL) and Activity and Participation (A&P) Basic Data Sets from English into Swedish.

Methods

The process of translation followed the Executive Committee for the International SCI Standards and Data Sets (ECSCI) recommendations. The initial translation was performed by translators. Experts in SCI were then assembled to scrutinize the translations and to reach a consensus for defining a final version.

Results

The whole process was time consuming. To save time in future translations, the start-up planning is of great importance. To identify appropriate participants with knowledge and interest to be part of the project is crucial. In addition, the consensus meetings, when scrutinizing the translated International SCI Data Sets, should be well prepared and structured. We identified a few steps that could make the process more efficient.

Conclusions

By adding a few steps as well as defining the role of a project coordinator, we believe that future translations of the International SCI Data Sets for non-English-speaking countries could be facilitated.

Primary prevention of stroke: randomised controlled pilot trial protocol on engaging everyday activities promoting health

INTRODUCTION

Stroke is a globally common disease that has detrimental effects on the individual and, more broadly, on society. Lifestyle change can contribute to reducing risk factors for stroke. Although a healthy lifestyle has direct benefits, sustaining and incorporating healthy activities into everyday life is a challenge. Engaging everyday activities have the potential to support lifestyle change and to promote sustainable activity patterns. Current healthcare is failing to reduce modifiable risk factors in people at risk, and in addition to current practice, there is a need for systematic and efficient non-pharmacological and non-surgical stroke-prevention strategies. The aim of the pilot study was to increase knowledge about the effects of a prevention programme and its feasibility to promote sustainable and healthy activity patterns among persons at risk of stroke.

METHODS AND ANALYSIS

The proposed pilot study will be a two-armed randomised, assessor-blinded, parallel pilot trial. The study will include feasibility data, investigating acceptability and delivery of the intervention. Persons at risk of stroke (n=60) will be included in a mobile phone-supported prevention programme. The 10-week programme will be conducted at primary healthcare clinics, combining group meetings and online resources to support self-management of lifestyle change. Main outcomes are stroke risk, lifestyle habits and healthy activity patterns. Assessments will be performed at baseline and at follow-up (immediately following the end of the programme and at 6 and 12 months). Effects of the programme will be analysed using inferential statistics. Feasibility will be analysed using both qualitative and quantitative methods.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Ethical Review Board in Stockholm, Sweden, being granted reference numbers 2015/834-31, 2016/2203-32 and 2019/01444. Study results will be disseminated through peer-review journals and presentations to mixed audiences at regional and international conferences.

TRIAL REGISTRATION NUMBER

NCT03730701.

Identification of amino acid residues of nerve growth factor important for neurite outgrowth in human dorsal root ganglion neurons

Nerve growth factor (NGF) is an essential neurotrophic factor for the development and maintenance of the central and the peripheral nervous system. NGF deficiency in the basal forebrain precedes degeneration of basal forebrain cholinergic neurons in Alzheimer's disease, contributing to memory decline. NGF mediates neurotrophic support via its high‐affinity receptor, the tropomyosin‐related kinase A (TrkA) receptor, and mediates mitogenic and differentiation signals via the extracellular signal‐regulated protein kinases 1 and 2 (ERK1/2). However, the molecular mechanisms underlying the different NGF/TrkA/ERK signalling pathways are far from clear. In this study, we have investigated the role of human NGF and three NGF mutants, R100E, W99A and K95A/Q96A, their ability to activate TrkA or ERK1/2, and their ability to induce proliferation or differentiation in human foetal dorsal root ganglion (DRG) neurons or in PC12 cells. We show that the R100E mutant was significantly more potent than NGF itself to induce proliferation and differentiation, and significantly more potent in activation of ERK1/2 in DRG neurons. The W99A and K95A/Q96A mutants, on the other hand, were less effective than the wild‐type protein. An unexpected finding was the high efficacy of the K95A/Q96A mutant to activate TrkA and to induce differentiation of DRG neurons at elevated concentrations. These data demonstrate an NGF mutant with improved neurotrophic properties in primary human neuronal cells. The R100E mutant represents an interesting candidate for further drug development in Alzheimer's disease and other neurodegenerative disorders.

Hormone Production by Human First-Trimester Gonads in a Functional In Vitro System

In the past, explant tissue-culture methodologies have been used to grow gonads and study their development. Results from in vitro cultures of human gonads showed limited progress toward gonadal cell differentiation and were focused mainly on germ-cell differentiation. Thus, detailed studies focusing on human first-trimester gonadal tissue functionality in vitro are still missing. In this study we investigated the endocrine function of human first-trimester gonads in vitro. We included 27 female and 28 male gonadal samples, derived from a total of 55 cases, at postconceptional ages of 4.5 to 10.5 weeks. Tissues were cultured using an explant tissue-culture system for 14 days. Assays for testosterone (liquid chromatography-tandem mass spectrometry), anti-Müllerian hormone (AMH; ELISA), and inhibin B (ELISA) were performed using media collected after 7 and 14 days of culture. We demonstrated sex- and age-dependent secretion profiles of testosterone, AMH, and inhibin B in the culture media, which resemble the pattern of hormone production in human gonads in vivo, from the few available studies at the same age range. Our study shows that explant tissue-culture conditions are robust for culture of human first-trimester gonadal somatic cells. Thus, it can be used to study human gonadal development and related diseases as well as the effect of potentially hormone-disturbing substances in human gonads during development. However, detailed molecular studies are needed for better understanding of the mechanistic control of the endocrine function of human first-trimester gonads.

A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord

Spinal root injuries result in newly formed glial scar formation, which prevents regeneration of sensory axons causing permanent sensory loss. Previous studies showed that delivery of trophic factors or implantation of human neural progenitor cells supports sensory axon regeneration and partly restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (MesoMIM), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along "bridges" formed by migrating stem cells. Coimplantation of MesoMIM prevented stem cell migration, "bridges" were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting their level of differentiation. Our data show that (1) the ability of stem cells to migrate into the spinal cord and organize cellular "bridges" in the newly formed interface is crucial for successful sensory axon regeneration, (2) trophic factor mimetics delivered by mesoporous silica may be a convenient alternative way to induce sensory axon regeneration, and (3) a combinatorial approach of individually beneficial components is not necessarily additive, but can be counterproductive for axonal growth.

Fetal CD103+ IL-17-Producing Group 3 Innate Lymphoid Cells Represent the Dominant Lymphocyte Subset in Human Amniotic Fluid

Amniotic fluid (AF) surrounds the growing fetus, and cells derived from AF are commonly used for diagnosis of genetic diseases. Intra-amniotic infections are strongly linked to preterm birth, which is the leading cause of perinatal mortality worldwide. Surprisingly little is known, however, about mature hematopoietic cells in AF, which could potentially be involved in immune responses during pregnancy. In this study, we show that the dominating population of viable CD45⁺ cells in AF is represented by a subset of fetal CD103⁺ group 3 innate lymphoid cells (ILCs) producing high levels of IL-17 and TNF. Fetal CD103⁺ ILC3s could also be detected at high frequency in second-trimester mucosal tissues (e.g., the intestine and lung). Taken together, our data indicate that CD103⁺ ILC3s accumulate with gestation in the fetal intestine and subsequently egress to the AF. The dominance of ILC3s producing IL-17 and TNF in AF suggests that they could be involved in controlling intra-amniotic infections and inflammation and as such could be important players in regulating subsequent premature birth.

Human neural progenitor cells in central nervous system lesions

Various immature cells can be isolated from human embryonic and fetal central nervous system (CNS) residual tissue and potentially be used in cell therapy for a number of neurological diseases and CNS insults. Transplantation of neural stem and progenitor cells is essential for replacing lost cells, particularly in the CNS with very limited endogenous regenerative capacity. However, while dopamine released from transplanted cells can substitute the lost dopamine neurons in the experimental models of Parkinson's disease, stem and progenitor cells primarily have a neuroprotective effect, probably through the release of trophic factors. Understanding the therapeutic effects of transplanted cells is crucial to determine the design of clinical trials. During the last few years, a number of clinical trials for CNS diseases and insults such as amyotrophic lateral sclerosis (ALS), stroke, and spinal cord trauma using neural progenitor cells have been initiated. Data from these early studies will provide vital information on the safety of transplanting these cells, which still is a major concern. That the beneficial results observed in experimental models also can be repeated in the clinical setting is highly hoped for.

A sensitive and reliable test instrument to assess swimming in rats with spinal cord injury

For clinical translation of experimental spinal cord injury (SCI) research, evaluation of animal SCI models should include several sensorimotor functions. Validated and reliable assessment tools should be applicable to a wide range of injury severity. The BBB scale is the most widely used test instrument, but similar to most others it is used to assess open field ambulation. We have developed an assessment tool for swimming in rats with SCI, with high discriminative power and sensitivity to functional recovery after mild and severe injuries, without need for advanced test equipment. We studied various parameters of swimming in four groups of rats with thoracic SCI of different severity and a control group, for 8 weeks after surgery. Six parameters were combined in a multiple item scale, the Karolinska Institutet Swim Assessment Tool (KSAT). KSAT scores for all SCI groups showed consistent functional improvement after injury, and significant differences between the five experimental groups. The internal consistency, the inter-rater and the test-retest reliability were very high. The KSAT score was highly correlated to the cross-section area of white matter spared at the injury epicenter. Importantly, even after 8 weeks of recovery the KSAT score reliably discriminated normal animals from those inflicted by the mildest injury, and also displayed the recovery of the most severely injured rats. We conclude that this swim scale is an efficient and reliable tool to assess motor activity during swimming, and an important addition to the methods available for evaluating rat models of SCI.

Transplanted Human Induced Pluripotent Stem Cell-Derived Neural Progenitor Cells Do Not Promote Functional Recovery of Pharmacologically Immunosuppressed Mice With Contusion Spinal Cord Injury

Improved functional recovery after spinal cord injury by transplantation of induced pluripotent stem cell-derived neural stem/progenitor cells (iPSC-NPCs) has been reported. However, beneficial effects of iPSC-based therapy have so far been produced mostly using genetically immunodeficient rodents. Because of the long time required for generation and characterization of iPSCs, the use of autologous iPSCs for treating patients with acute spinal cord injury (SCI) is not feasible. Therefore, it is of utmost importance to investigate the effect of iPSC-based therapy on functional recovery after SCI using pharmacologically immunosuppressed, immunocompetent animal models. Here we studied the functional outcome following subacute transplantation of human iPSC-derived NPCs into contused mouse spinal cord when tacrolimus was used as an immunosuppressive agent. We show that human iPSC-derived NPCs transplanted into pharmacologically immunosuppressed C57BL/6J mice exhibited poor long-term survival and failed to improve functional recovery after SCI as measured by Basso Mouse Scale (BMS) for locomotion and CatWalk gait analysis when compared to vehicle-treated animals. The scarce effect of iPSC-based therapy observed in the current study may be attributable to insufficient immunosuppressive effect, provided by monotherapy with tacrolimus in combination with immunogenicity of transplanted cells and complex microenvironment of the injured spinal cord. Our results highlight the importance of extensive preclinical studies of transplanted cells before the clinical application of iPSC-based cell therapy is achieved.

Interplay between human microglia and neural stem/progenitor cells in an allogeneic co-culture model

Experimental neural cell therapies, including donor neural stem/progenitor cells (NPCs) have been reported to offer beneficial effects on the recovery after an injury and to counteract inflammatory and degenerative processes in the central nervous system (CNS). The interplay between donor neural cells and the host CNS still to a large degree remains unclear, in particular in human allogeneic conditions. Here, we focused our studies on the interaction of human NPCs and microglia utilizing a co-culture model. In co-cultures, both NPCs and microglia showed increased survival and proliferation compared with mono-cultures. In the presence of microglia, a larger subpopulation of NPCs expressed the progenitor cell marker nestin, whereas a smaller group of NPCs expressed the neural markers polysialylated neural cell adhesion molecule, A2B5 and glial fibrillary acidic protein compared with NPC mono-cultures. Microglia thus hindered differentiation of NPCs. The presence of human NPCs increased microglial phagocytosis of latex beads. Furthermore, we observed that the expression of CD200 molecules on NPCs and the CD200 receptor protein on microglia was enhanced in co-cultures, whereas the release of transforming growth factor-β was increased suggesting anti-inflammatory features of the co-cultures. To conclude, the interplay between human allogeneic NPCs and microglia, significantly affected their respective proliferation and phenotype. Neural cell therapy including human donor NPCs may in addition to offering cell replacement, modulate host microglial phenotypes and functions to benefit neuroprotection and repair.

Biogrid--a microfluidic device for large-scale enzyme-free dissociation of stem cell aggregates

Culturing stem cells as free-floating aggregates in suspension facilitates large-scale production of cells in closed systems, for clinical use. To comply with GMP standards, the use of substances such as proteolytic enzymes should be avoided. Instead of enzymatic dissociation, the growing cell aggregates may be mechanically cut at passage, but available methods are not compatible with large-scale cell production and hence translation into the clinic becomes a severe bottle-neck. We have developed the Biogrid device, which consists of an array of micrometerscale knife edges, micro-fabricated in silicon, and a manifold in which the microgrid is placed across the central fluid channel. By connecting one side of the Biogrid to a syringe or a pump and the other side to the cell culture, the culture medium with suspended cell aggregates can be aspirated, forcing the aggregates through the microgrid, and ejected back to the cell culture container. Large aggregates are thereby dissociated into smaller fragments while small aggregates pass through the microgrid unaffected. As proof-of-concept, we demonstrate that the Biogrid device can be successfully used for repeated passage of human neural stem/progenitor cells cultured as so-called neurospheres, as well as for passage of suspension cultures of human embryonic stem cells. We also show that human neural stem/progenitor cells tolerate transient pressure changes far exceeding those that will occur in a fluidic system incorporating the Biogrid microgrids. Thus, by using the Biogrid device it is possible to mechanically passage large quantities of cells in suspension cultures in closed fluidic systems, without the use of proteolytic enzymes.

Forced Runx1 expression in human neural stem/progenitor cells transplanted to the rat dorsal root ganglion cavity results in extensive axonal growth specifically from spinal cord-derived neurospheres

Cell replacement therapy holds great promise for treating a wide range of human disorders. However, ensuring the predictable differentiation of transplanted stem cells, eliminating their risk of tumor formation, and generating fully functional cells after transplantation remain major challenges in regenerative medicine. Here, we explore the potential of human neural stem/progenitor cells isolated from the embryonic forebrain (hfNSPCs) or the spinal cord (hscNSPCs) to differentiate to projection neurons when transplanted into the dorsal root ganglion cavity of adult recipient rats. To stimulate axonal growth, we transfected hfNSPC- and hscNSPC-derived neurospheres, prior to their transplantation, with a Tet-Off Runx1-overexpressing plasmid to maintain Runx1 expression in vivo after transplantation. Although pronounced cell differentiation was found in the Runx1-expressing transplants from both cell sources, we observed extensive, long-distance growth of axons exclusively from hscNSPC-derived transplants. These axons ultimately reached the dorsal root transitional zone, the boundary separating peripheral and central nervous systems. Our data show that hscNSPCs have the potential to differentiate to projection neurons with long-distance axonal outgrowth and that Runx1 overexpression is a useful approach to induce such outgrowth in specific sources of NSPCs.

Markers of pluripotency and differentiation in human neural precursor cells derived from embryonic stem cells and CNS tissue

Cell transplantation therapies for central nervous system (CNS) deficits such as spinal cord injury (SCI) have been shown to be effective in several animal models. One cell type that has been transplanted is neural precursor cells (NPCs), for which there are several possible sources. We have studied NPCs derived from human embryonic stem cells (hESCs) and human fetal CNS tissue (hfNPCs), cultured as neurospheres, and the expression of pluripotency and neural genes during neural induction and in vitro differentiation. mRNA for the pluripotency markers Nanog, Oct-4, Gdf3, and DNMT3b were downregulated during neural differentiation of hESCs. mRNA for these markers was found in nonpluripotent hfNPC at higher levels compared to hESC-NPCs. However, Oct-4 protein was found in hESC-NPCs after 8 weeks of culture, but not in hfNPCs. Similarly, SSEA-4 and CD326 were only found in hESC-NPCs. NPCs from both sources differentiated as expected to cells with typical features of neurons and astrocytes. The expressions of neuronal markers in hESC-NPCs were affected by the composition of cell culture medium, while this did not affect hfNPCs. Transplantation of hESC-NPC or hfNPC neurospheres into immunodeficient mouse testis or subcutaneous tissue did not result in tumor formation. In contrast, typical teratomas appeared in all animals after transplantation of hESC-NPCs to injured or noninjured spinal cords of immunodeficient rats. Our data show that transplantation to the subcutaneous tissue or the testes of immunodeficient mice is not a reliable method for evaluation of the tumor risk of remaining pluripotent cells in grafts.

Long-Term Survival, Robust Neuronal Differentiation, and Extensive Migration of Human Forebrain Stem/Progenitor Cells Transplanted to the Adult Rat Dorsal Root Ganglion Cavity

Neurons in dorsal root ganglia (DRGs) transmit sensory information from peripheral tissues to the spinal cord. This pathway can be interrupted, for example, as the result of physical violence, traffic accidents, or complications during child delivery. As a consequence, the patient permanently loses sensation and often develops intractable neuropathic pain in the denervated area. Here we investigate whether human neural stem/progenitor cells (hNSPCs) transplanted to the DRG cavity can serve as a source for repairing lost peripheral sensory connections. We found that hNSPCs robustly differentiate to neurons, which survive long-term transplantation. The neuronal population in the transplants was tightly surrounded by astrocytes, suggesting their active role in neuron survival. Furthermore, 3 months after grafting hNSPCs were found in the dorsal root transitional zone (DRTZ) and within the spinal cord. The level of differentiation of transplanted cells was high in the core of the transplants whereas cells that migrated to the DRTZ and spinal cord were undifferentiated, nestin-expressing precursors. These data indicate that peripherally transplanted hNPSCs can be used for repair of dorsal root avulsion or spinal cord injuries; however, additional factors are required to guide their differentiation to the desired type of neurons. Furthermore, hNPSCs that migrate from the DRG cavity graft site to the DRTZ and spinal cord may provide trophic support for regenerating dorsal root axons, thereby allowing them to reenter the host spinal cord.