Organisation, influence, and impact of patient advisory boards in rehabilitation institutions-an explorative cross-sectional study

Background

Patient participation is highlighted as an important facilitator for patient-centered care. Patient participation organised as patient advisory boards (PABs) is an integral part of health care institutions in Norway. More knowledge is needed on how PAB representatives experience patient engagement (PE) with regard to organisation, influence, and impact. The objective was to describe how PAB representatives experience their tasks, roles, and impact on decision-making processes and service delivery in the setting of rehabilitation institutions.

Methods

PAB representatives recruited from rehabilitation institutions completed the Norwegian version of the generic Public and Patient Engagement evaluation tool (Norwegian abbreviation EBNOR). EBNOR is tested for reliability and validity with good results and comprises 35 items within four main domains, policies and practices, participatory culture, collaboration, and influence and impact that provide responses about PE-levels. The domain items are scored from “strongly disagree” to “strongly agree” on a five-point scale, in addition to a don’t know category. Items in the domain “influence and impact” are scored from “never” to “all of the time” on a four-point scale. Categorical data were summarized using frequencies and percentages, and response categories were collapsed into three PE-levels: barrier, intermediate, and facilitating level. Free-text responses were analysed according to principles of manifest content analysis, summed up, and used to elaborate the results of the scores.

Results

Of the 150 contacted PAB representatives, 47 (32%) consented to participate. The results showed that approximately 75% agreed that the organisation as a whole was strengthened as a result of patient participation. Four out of five domains were scored indicating a facilitating level; policies and practices (53%), participatory culture (53%), collaboration and common purpose (37%), and final thoughts (63%). The modal score in the domain influence and impact was in the intermediate PE-level (44%). Of a total of 34 codes from free text analyses, barriers to PE were coded 26 times, and PE facilitators were coded 8 times.

Conclusions

The findings indicate that most PAB representatives are satisfied with how rehabilitation institutions organise their PAB, but they still experience their impact as limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05678-y.

The Public and Patient Engagement Evaluation Tool: forward-backwards translation and cultural adaption to Norwegian

Background

Patient engagement is recommended for improving health care services, and to evaluate its organisation and impact appropriate, and rigorously evaluated outcome measures are needed.

Methods

Interviews (N = 12) were conducted to assess relevance of the Canadian Public and Patient Engagement Evaluation Tool (PPEET) in a Norwegian setting were performed. The tool was translated, back translated, and assessed following cognitive interviews (N = 13), according to the COSMIN checklist. Data quality was assessed in a cross-sectional survey of patient advisory board members from different rehabilitation institutions (N = 47).

Results

Interviews with patient board representatives confirmed the relevance of the PPEET Organisational questionnaire in a Norwegian setting and contributed five additional items. Translation and back translation of the original PPEET showed no major content differences. Differences in vocabulary and sentence structure were solved by discussion among the translators. Comments from cognitive interviews mainly related to the use of different synonyms, layout, and minor differences in semantic structure. Results of the cross-sectional survey support the data quality and construct validity of PPEET items, including 95 score comparisons where 76 (80%) were as hypothesized.

Conclusions

The PPEET Organisational questionnaire has been thoroughly translated and tested, and the resulting Evalueringsverktøy for Brukermedvirkning (EBNOR) has adequate levels of comprehensibility and content validity. Further testing for measurement properties is recommended, but given these results, the EBNOR should be considered for assessing patient engagement in a Norwegian health care organisational context.

POS0090-PARE ORGANIZATION, INFLUENCE, AND IMPACT OF PATIENT ADVISORY BOARD REPRESENTATION IN PRIVATE REHABILITATION INSTITUTIONS – AN EXPLORATIVE CROSS-SECTIONAL STUDY

Background

Patient participation (PP) organised as patient advisory boards (PABs) is a statutory part of health care institutions in Norway (1). There is limited agreement on how to engage PABs in a meaningful manner (2). More knowledge on how PAB representatives experience patient engagement (PE) is needed.

Objectives

To explore how PAB representatives engage in PABs with regard to organisation, influence, and impact on decision-making processes and service delivery.

Methods

PAB representatives recruited from rehabilitation institutions, representing all four health regions in Norway completed a PE evaluation tool. The tool is tested for reliability and content validity with good results and comprises 35 items including four main domains policies and practices, participatory culture, collaboration, and influence and impact that provided responses about PE-levels (3). Categorical data were summarized to modal scores using frequencies and percentages, and response categories were collapsed from five to three. The collapsed categories were divided into PE-levels; barrier, intermediate, and facilitator (Table 1). Free-text responses were analysed according to principles of manifest content analysis, summed up, and used to complete the results of the scores. Free text responses were analysed using Quirkos version 2.4.1.

Results

Of the 150 contacted PAB representatives, 47 (32%) responded. PAB representatives’ mean age was 60.5 (min-max 30 - 80), 62% were female and a majority (81%) had prior experience with PP. The results showed that 75% of the participants agreed that patient-centered care was strengthened as a result of PE. Three out of four main domains scored indicating a facilitating PE-level (Table 1). The domain, influence and impact scored with an intermediate PE-level. Regarding influence and impact, half of the participants did not know if PE input had influenced management decisions, and 60% had rarely identified any PE contributions. The results from free text analyses showed that PE was coded as a facilitator seven times, and as a barrier to PE 26 times. The most frequent barrier was exclusion of PAB (13 codes), and the most coded facilitator was inclusion of PAB (3 codes).

Conclusion

Findings indicate that PAB representatives are satisfied with how rehabilitation institutions organise PABs. Unclear adherence to the values and principles of PP may hinder influence and visibility from PE contributions.

References

[1](The Norwegian Directorate of Health) Helsedirektoratet. Veileder om oppfølging av personer med store og sammensatte behov [online document]. Oslo: Helsedirektoratet; 2017 [updated 11.02.2019; cited 2021 20.09]. Available from: https://www.helsedirektoratet.no/veiledere/oppfolging-av-personer-med-store-og-sammensatte-behov

[2]Scholl, I., et al., Organizational- and system-level characteristics that influence implementation of shared decision-making and strategies to address them - a scoping review. Implement Sci, 2018. 13(1): p. 40.

[3]Garratt A, Sagen J, Børøsund E, Varsi C, Kjeken I, Dagfinrud H, et al. The Public and Patient Engagement Evaluation Tool: Forward-backwards translation and cultural adaption to Norwegian BMC Musculoskelet Disord. Submitted.

Table 1

Acknowledgements

The authors acknowledge all participants who took part in this study, VIRKE and UNICARE rehabilitation organisations for cooperation, and DAM Foundation for founding.

Disclosure of Interests

None declared

Personally-Generated Quality of Life Outcomes in Adults with Juvenile Idiopathic Arthritis

OBJECTIVE

To explore quality of life (QOL) using the individualized Patient Generated Index (PGI) in young adults who were diagnosed with JIA in childhood, and examine associations between PGI ratings and standardized health-related outcome measures.

METHODS

Patients (N=79, mean 25.1 ±4.2 yrs, 72% female) completed the PGI and the standardized measures: Health Assessment Questionnaire Disability Index, Medical Outcome Study 12-item Short-Form (SF-12; physical and mental health-related QOL), Brief Pain Inventory Short-Form (pain severity and interference), Hopkins Symptom Checklist-5 and visual analogue scale for fatigue. Information on morning-stiffness, medications, and demographics was also collected. Patients were compared to 79 matched controls.

RESULTS

The most frequently nominated areas of importance for patients' personally-generated QOL (assessed by PGI) were physical activity (n=38, 48%), work/school (n=31, 39%), fatigue (n=29, 37%) and self-image (n=26, 33%). Nomination of physical activity was associated with older age, more pain interference and morning-stiffness. Nomination of fatigue was associated with current use of disease-modifying antirheumatic drugs, while nomination of self-image was associated with polyarticular course JIA and pain interference. Nomination of work/school was not associated with other factors. Higher PGI scores (indicating better QOL) correlated positively with all SF- 12 subscales except role-emotional and negatively with disability, pain severity, pain interference and morning-stiffness. Compared to controls, patients had more pain, poorer physical health-related QOL and less participation in full-time work or school.

CONCLUSION

Physical activity, work/school, fatigue and self-image were frequently nominated areas affecting QOL in young adults with JIA. The PGI included aspects of QOL not covered in standardized measures.

Treatment Satisfaction With and Adherence to Disease-Modifying Antirheumatic Drugs in Adult Patients With Juvenile Idiopathic Arthritis

OBJECTIVE

To examine medication satisfaction and adherence and their relationships to disease variables and health-related quality of life (HRQoL) in adults with juvenile idiopathic arthritis (JIA).

METHODS

Patients (n = 96, mean age 25 years, 67% female) completed questionnaires about their health status 19 years after disease onset. Patients receiving biologic disease-modifying antirheumatic drugs (bDMARDs) or methotrexate (MTX) were assessed with the 8-item Morisky Medication Adherence Scale (MMAS-8) and the Treatment Satisfaction Questionnaire for Medication (TSQM), including dimensions of effectiveness, side effects, convenience, and global satisfaction.

RESULTS

DMARDs were received by 52 patients (54%) (mean age 25 years, 75% female), of which 28 received MTX and 37 received bDMARDs. Patients receiving combination therapy of MTX and bDMARDs (n = 15) reported higher satisfaction with bDMARDs than MTX in the dimensions of side effects and global satisfaction (mean ± SD 92.9 ± 15.5 versus 56.2 ± 30.9, and mean ± SD 67.6 ± 19.8 versus 47.1 ± 21.7; P < 0.001 and P = 0.016, respectively). Patients receiving either bDMARDs (n = 22) or MTX (n = 13) reported higher satisfaction with bDMARDs than MTX for the dimensions of effectiveness and global satisfaction (mean ± SD 78.7 ± 15.4 versus 60.2 ± 19.9, and mean ± SD 73.6 ± 17.7 versus 52.3 ± 23.9; P = 0.004 and P = 0.005, respectively). Nearly one-half of patients (46%) reported low adherence (MMAS-8 score <6) and 25% high adherence (MMAS-8 score = 8). Higher levels of pain, psychological distress, more active joints, and current MTX use were the strongest correlates of lower medication satisfaction. Perceived medication effectiveness and global satisfaction correlated positively with physical and mental HRQoL.

CONCLUSION

Patients with JIA were more satisfied with bDMARDs than MTX, and 46% reported low adherence. Higher medication satisfaction was associated with better HRQoL.

Long-Term Viability of Isolated Bovine Adrenal Medullary Chromaffin Cells following Intrastriatal Transplantation

Adrenal medullary grafts generally exhibit poor viability when grafted into the striatum. Previous work in our laboratory demonstrated that chromaffin cells can survive well for up to 2 mo following grafting into the intact rat striatum after cells are isolated from the nonchromaffin supporting cells (fibroblasts and endothelial cells) of the adrenal medulla. The aim of the present study was to assess the long-term viability of isolated bovine chromaffin cells following grafting into the intact rat striatum. The viability of grafted bovine adrenal medullary chromaffin cells was compared in rats receiving either (a) perfused adrenal medulla; (b) isolated chromaffin cells; or (c) isolated chromaffin cells that were subsequently recombined with their nonchromaffin supporting cells. One year postimplantation, all graft types which included fibroblasts and endothelial cells were infiltrated with macrophages and demonstrated an abundance of cellular debris. No viable chromaffin cells were observed. In contrast, healthy tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DβH) immunoreactive chromaffin cells survived for 1 yr posttransplantation when grafted in isolation from the nonchromaffin constituents of the adrenal medulla. Good xenograft survival was achieved in this group despite the fact that these rats were only immunosuppressed for 1 mo postimplantation. Grafted cells demonstrated morphological characteristics of chromaffin cells in situ and these implants were not accompanied by macrophage infiltration. These data demonstrate that long-term survival of chromaffin cells can be achieved following intrastriatal implantation and the viability of grafted chromaffin cells is dependent upon the removal of the nonchromaffin supporting cells.

Bovine Chromaffin Cells for CNS Transplantation do not Elicit Xenogeneic T Cell Proliferative Responses in Vitro

Adrenal chromaffin cells have been utilized for several neural grafting applications, but limitations in allogeneic donor availability and dangers inherent in auto-grafting limit the widespread use of this approach clinically. While xenogeneic donors offer promise as a source for cell transplantation in the central nervous system (CNS), immunologic responses to cellular components of the adrenal medulla have not been well characterized. To further study the host T cell xenogeneic response to chromaffin and passenger cells of the adrenal medulla, an in vitro lymphocyte proliferation assay was used. Lymphocyte proliferation was determined by mixing rat lymphocytes with potential stimulator cell subpopulations of the bovine adrenal medulla: isolated chromaffin cells, isolated endothelial cells, or passenger nonchromaffin cells, which include a mixture of fibroblasts, smooth muscle cells, and endothelial cells. As a positive control, bovine aortic endothelial cells were also used. 3[H]-thymidine incorporation, corresponding to lymphocyte proliferation, was measured. Results indicated that isolated bovine chromaffin cells produce only a mild, statistically insignificant stimulation of rat lymphocytes. In contrast, there was a significant response to passenger nonchromaffin cells of the adrenal medulla, especially endothelial cells. The inclusion of low levels of cyclosporin A in the cultures completely eliminated the mild proliferative response to isolated bovine chromaffin cells, while near toxic levels were necessary to abrogate the response to endothelial cells. Immunocytochemical analysis revealed that routine chromaffin cell isolation procedures result in the inclusion of a small percentage of endothelial cells, which may be responsible for the slight lymphocyte stimulation. The results of this study indicate that isolated chromaffin cells possess low immunogenicity, and suggest that passenger cells in the adrenal medulla, particularly endothelial cells, may be primarily responsible for progressive rejection in CNS grafts. Thus, removal of passenger nonchromaffin cells from xenogeneic donor tissues prior to transplantation may produce a more tolerated graft in rodent models of neural transplantation.

Short-Term Immunosuppression Enhances Long-Term Survival of Bovine Chromaffin Cell Xenografts in Rat Cns

Xenogeneic donors, a largely untapped resource, would solve many of the problems associated with the limited availability of human donor tissue for neural transplantation. Previous work in our laboratory has revealed that xenografts of isolated bovine chromaffin cells survive transplantation into the periaqueductal gray (PAG) of immunosuppressed adult rats. Electron microscopic analysis reveals that graft sites contain healthy chromaffin cells, but do not contain host immune cells typical of graft rejection.

The aim of the current study was to assess the necessary conditions for long-term survival of bovine chromaffin cell xenografts in the central nervous system (CNS). In particular, the need for short-course vs. permanent immunosuppressive therapy with cyclosporine A (CsA) for the long-term survival of grafted bovine chromaffin cells was addressed. Grafts from animals receiving continuous CsA treatment for either 3, 6, or 12 wk contained large clumps of dopamines-β-hydroxylase (DBH) positive cells in contrast to the few surviving cells observed in nonimmunosuppressed animals. In addition, grafts from animals that had CsA treatment terminated at 3 or 6 wk contained similarly large clumps of DBH-positive cells. Furthermore, short-term immunosuppression (3 wk) appeared to enhance the long-term survival of grafted cells, since clumps of DBH staining cells could still be positively identified in the host PAG at least 1 yr after transplantation.

Complete rejection of graft tissue depends on several factors, such as blood–brain barrier integrity, the presence of major histocompatability complex (MHC) antigens in either the host or graft, and the status of the host immune system. By using a suspension of isolated bovine chromaffin cells, potential MHC antigen presenting cells, such as endothelial cells, are eliminated. In addition, CsA treatment may negate the immunologic consequences of increased blood–brain barrier permeability following surgical trauma by attenuating the host cell mediated response. In summary, long-term survival of isolated chromaffin cell xenografts in the rat CNS may be attained by a short-term course of CsA.

A gel electrophoresis method for detection of mitochondrial DNA mutation (3243 tRNALeu (UUR)) applied to a Norwegian family with diabetes mellitus and hearing loss

Blood cells of selected patients from a large Norwegian family with maternally transmitted diabetes mellitus, hearing loss and muscular dysfunction were screened for possible A3243G mutation tRNA(Leu (UUR)) in mitochondrial DNA. We selected 7 patients from 3 of the 4 generations of the family and 10 unrelated healthy control subjects for mutation analysis using denaturing gradient gel electrophoresis (DGGE) and both manual and automated DNA sequencing. The A3243G mutation was found in peripheral blood cells of all 7 patients, but in none of the controls. The mutation was in the form of heteroplasmy and the amount of mutant DNA was found to be between 10% and 35% of total mtDNA in individual patients. This is the first report of a Norwegian family with maternally inherited diabetes and hearing loss carrying the A3243G mutation in mitochondrial DNA.

Automated method for isolation of adrenal medullary chromaffin cells from neonatal porcine glands

An automated method for the isolation of neonatal porcine adrenal chromaffin cells is described. Adrenal chromaffin cells are potentially useful for therapeutic transplantation, but current isolation methodology suffers from labor intensiveness and variability in yield and viability due to imprecision of manual techniques, enzyme purity, and gland age and species. The described approach utilizes an adaptation of an automated procedure previously described for isolation of pancreatic islets. Results from neonatal porcine adrenal glands revealed consistent cell yields with high (approximately 99%) viability. Catecholamine assays showed that the resultant cultures continue to produce and secrete norepinephrine and epinephrine. Immunocytochemical analysis indicated that the majority of cells in the preparation are chromaffin cells and adrenal cortical cells. The procedure meets the following requirements: 1) minimal traumatic action on the adrenal chromaffin cells, 2) continuous digestion in which the adrenal cells that are progressively liberated can be saved from further mechanical action, 3) minimal human intervention in the digestion process, and 4) high yield and viability of the isolated adrenal chromaffin cells.

Peripheral nerve exposure to HIV viral envelope protein gp120 induces neuropathic pain and spinal gliosis

Painful sensory neuropathy is a common and debilitating consequence of human immunodeficiency virus (HIV). The underlying causes of neuropathic pain are most likely not due to direct infection of the nervous system by active virus. The goal of this study was to determine whether epineural exposure to the HIV-1 envelope protein gp120 could lead to chronic painful peripheral neuropathy. Two doses of gp120 or BSA control were transiently delivered epineurally via oxidized cellulose wrapped around the rat sciatic nerve. Animals were assessed for neuropathic pain behaviors at several intervals from 1-30 days following nerve surgery. Allodynia and hyperalgesia were observed within 1-3 days following gp120 and sustained throughout the testing period. The gp120-exposed sciatic nerve exhibited early but transient pathology, notably axonal swelling and increased tumor necrosis factor alpha (TNF-alpha) within the nerve trunk. In contrast, intense astrocytic and microglial activation was observed in the spinal cord, and this gliosis persisted for at least 30 days following epineural gp120, in parallel with neuropathic pain behaviors. These findings demonstrate that limited peripheral nerve exposure to HIV protein can induce persistent painful sensory neuropathy that may be sustained and magnified by long-term spinal neuropathology.

Spinal allografts of adrenal medulla block nociceptive facilitation in the dorsal horn

Transplantation of chromaffin cells into the lumbar subarachnoid space has been found to produce analgesia, most conspicuously against chronic neuropathic pain. To ascertain the neurophysiological mechanism, we recorded electrical activity from wide-dynamic-range dorsal horn neurons in vivo, measuring the short-lasting homosynaptic facilitatory effect known as windup, which is induced by repetitive C-fiber input. Rats were given adrenal medulla allografts, or, as controls, striated-muscle allografts. The adrenal-transplanted rats showed analgesia 3--4 wk after transplantation, measured as a reduction in flinching reflexes 30--55 min after subcutaneous formalin injection. Recordings were made under halothane anesthesia, 3--7 days following the behavioral testing. The average C-fiber response and subsequent afterdischarge were facilitated severalfold in control rats by 1-Hz cutaneous electrical stimulation. Such facilitation was essentially absent in adrenal-transplanted animals and also in the A-fiber response of both preparations. Extirpation of transplanted tissue several hours prior to recording did not significantly affect this difference. In conclusion, the adrenal transplants block short-term spinal nociceptive facilitation, probably by stimulating some persistent cellular process that may be an important determinant, but not the only one, of their analgesic effect.

Alterations in endogenous brain beta-endorphin release by adrenal medullary transplants in the spinal cord

While transplants of adrenal medullary cells into the spinal subarachnoid space may produce antinociception via inhibition of spinal pain transmission pathways, alterations at higher central nervous system (CNS) centers have not been addressed. Recent findings suggest that prolonged noxious stimulation results in release of endogenous beta-endorphin in the brain, possibly as a compensatory mechanism to reduce nociception. The goal of this study was to determine whether adrenal medullary transplants in the spinal subarachnoid space alter endogenous beta-endorphin secretion in the hypothalamic arcuate nucleus, its principal CNS source. Pain behaviors and arcuate beta-endorphin secretion by microdialysis were monitored during the formalin pain test in animals with spinal adrenal medullary or control transplants. Basal levels of extracellular beta-endorphin were 3-fold higher in adrenal medullary-implanted than in controls. In control animals, formalin induced robust pain behaviors and a marked transient increase in beta-endorphin release 30-60 min following injection. In contrast, pain behaviors were attenuated and the formalin-induced increase in beta-endorphin was completely blocked in adrenal medullary implanted animals. Findings from these studies indicate that adrenal medullary transplants in the spinal subarachnoid space can alter beta-endorphin release in the arcuate nucleus both basally and in response to noxious stimuli. Thus, spinally placed adrenal medullary transplants not only alter local spinal cord pharmacology, but can alter endogenous neurochemistry at higher pain processing centers as well.

Initial characterization of the transplant of immortalized chromaffin cells for the attenuation of chronic neuropathic pain

Cultures of embryonic day 17 (E17) rat adrenal and neonatal bovine adrenal cells were conditionally immortalized with the temperature-sensitive allele of SV40 large T antigen (tsTag) and chromaffin cell lines established. Indicative of the adrenal chromaffin phenotype, these cells expressed immunoreactivity (ir) for tyrosine hydroxylase (TH), the first enzyme in the synthetic pathway for catecholamines. At permissive temperature in vitro (33 degrees C), these chromaffin cells are proliferative, have a typical rounded chromaffin-like morphology, and contain detectable TH-ir. At nonpermissive temperature in vitro (39 degrees C), these cells stop proliferating and express increased TH-ir. When these immortalized chromaffin cells were transplanted in the lumbar subarachnoid space of the spinal cord I week after a unilateral chronic constriction injury (CCI) of the rat sciatic nerve, they survived longer than 7 weeks on the pia mater around the spinal cord and continued to express TH-ir. Conversely, grafted chromaffin cells lost Tag-ir after transplant and Tag-ir was undetectible in the grafts after 7 weeks in the subarachnoid space. At no time did the grafts form tumors after transplant into the host animals. These grafted chromaffin cells also expressed immunoreactivities for the other catecholamine-synthesizing enzymes 7 weeks after grafting, including: dopamine-beta-hydroxylase (DbetaH) and phenylethanolamine-N-methyltransferase (PNMT). The grafted cells also expressed detectable immunoreactivities for the opioid met-enkephalin (ENK), the peptide galanin (GAL), and the neurotransmitters y-aminobutyric acid (GABA) and serotonin (5-HT). Furthermore, after transplantation, tactile and cold allodynia and tactile and thermal hyperalgesia induced by CCI were significantly reduced during a 2-8-week period, related to the chromaffin cell transplants. The maximal antinociceptive effect occurred 1-3 weeks after grafting. Control adrenal fibroblasts, similarly immortalized and similarly transplanted after CCI, did not express any of the chromaffin antigenic markers, and fibroblast grafts had no effect on the allodynia and hyperalgesia induced by CCI. These data suggest that embryonic and neonatal chromaffin cells can be conditionally immortalized and will continue to express the phenotype of primary chromaffin cells in vitro and in vivo; grafted cells will ameliorate neuropathic pain after nerve injury and can be used as a homogeneous source to examine the mechanisms by which chromaffin transplants reverse chronic pain. The use of such chromaffin cell lines that are able to deliver antinociceptive molecules in models of chronic pain after nerve and spinal cord injury (SCI) offers a novel approach to pain management.

Generation and initial characterization of conditionally immortalized chromaffin cells

Adrenal chromaffin cells have been successfully used to attenuate chronic pain when transplanted near the spinal cord, but primary cells are neither homogeneous nor practical for routine use in human therapy. Conditional immortalization with the temperature-sensitive allele of the large T antigen (tsTag) and creation of stable chromaffin cell lines would advance our understanding of both the use and limits of cell lines that contain this immortalization gene for such therapies. Cultures of embryonic day 17 rat adrenal and neonatal bovine adrenal cells were immortalized with the temperature-sensitive allele of SV40 tsTag and chromaffin cell lines established. The rat chromaffin line, RAD5.2, and the bovine chromaffin cell line, BADA.20, both expressed immunoreactivities (ir) for all the catecholamine enzymes: tyrosine hydroxylase (TH), the first enzyme in the synthetic pathway for catecholamines, dopa-beta-hydroxylase (DbetaH), and phenylethanolamine-N-methyltransferase (PNMT). At permissive temperature (33 degrees C), these chromaffin cells are proliferative, have a typical rounded chromaffinlike morphology, and contain detectable TH-, DbetaH-, and PNMT-ir. At nonpermissive temperature (39 degrees C), these cells stop proliferating, decrease Tag expression, and change the expression of TH-, DbetaH-, and PNMT-ir in vitro, suggesting increased differentiation at nonpermissive temperature. The chromaffin cell lines also express immunoreactivity for the opioid met-enkephalin (ENK) at permissive and nonpermissive temperatures. The expression of TH-ir in the bovine chromaffin cells is upregulated by the addition of dexamethasone (DEX) or forskolin during differentiation; TH-ir is not affected by the addition of DEX or forskolin in the rat chromaffin cells. The addition of forskolin during differentiation upregulates the expression of DbetaH-ir in the rat chromaffin cells. PNMT-ir is not affected by differentiation or agents in either cell line. However, catecholamine synthesis was not detectable by high-performance liquid chromatography, suggesting incomplete differentiation under current conditions, or influence by continued low levels of Tag expression. Both cell lines have been carried over many passages in vitro for more than 3 years and were repeatedly frozen and thawed. These data describe an initial step in the conditional immortalization of chromaffin cells that can maintain the phenotype of primary chromaffin cells in vitro over long periods. The use of such chromaffin cell lines that are able to deliver neuroactive molecules offers a novel approach to pain management.

Spinal CSF from rats with painful peripheral neuropathy evokes catecholamine release from chromaffin cells in vitro

The environment presented by host tissue may influence cellular transplants in the CNS depending on injury or disease. Here we examined whether chronic pain alters cerebrospinal fluid (CSF), thereby enhancing the analgesic effect of transplanted adrenal cells. CSF samples were taken intracisternally from rats with neuropathic pain induced by chronic constriction injury of the sciatic nerve. The samples were applied to cultured bovine chromaffin-cell clusters while catecholamine release was measured by fast cyclic voltammetry. This caused marked and sustained elevations in catecholamine levels, compared to CSF from sham-operated controls, which were reversible by the nicotinic antagonist mecamylamine. These results suggest that chronic neuropathic pain produces increased CSF levels of secretogogues for chromaffin cells, and illustrates the importance of host microenvironmental factors in determining graft function.

Adrenal medullary explants as an efficient tool for pain control: adhesive biomolecular components are involved in graft function ex vivo

Adrenal medullary (AM) tissue transplantation into the central nervous system has been reported as a potential source of opioid peptides and catecholamines, which have analgesic effects useful in the control of chronic pain. Clinical trials, involving allogeneic graft of whole tissue explants into the subarachnoid space of the lumbar spinal cord, have already been reported. The aim of the present study was to determine whether adhesion and function of AM explants were related in some extent and how this relationship could account for improvement of AM tissue in terms of analgesic activity before grafting. Our experiments demonstrated a significant correlation between the adherent state of AM organoids during culture and a sustained secretion of Met-enkephalin and catecholamines by chromaffin cells (CC). These findings suggest that optimal culture condition for AM organoid adhesion can be defined for maintenance of tissue, prior to transplantation. Using immunocytochemistry, flow cytometry, and ELISA assays we showed that different cell adhesion molecules (CAMs) and extracellular matrix ECM proteins were expressed and released by AM cells during culture. Adherent AM organoids expressed increased levels of specific neural CAMs (NCAM and HNK-1 epitope) and integrin chains (beta1, alpha1, alpha2, alpha4, alpha5) and deposited markedly higher levels of fibronectin, but also laminin and collagen IV. Those molecules and probably adhesion processes they control might be involved in the maintenance of the CC-secreting neuroendocrine phenotype through cellular signaling pathways.

NMDA-induced spinal hypersensitivity is reduced by naturally derived peptide analog [Ser1]histogranin

N-methyl-D-aspartate (NMDA) receptor activation is thought to initiate a cellular cascade of events in the spinal cord that leads to neuronal hyperactivation and exaggerated persistent pain behaviors. Previous studies have demonstrated that implantation of adrenal medullary tissue into the spinal subarachnoid space reduces abnormal pain behaviors such as hyperalgesia and allodynia, possibly by intervening in the NMDA hyperexcitability cascade. Histogranin is a 15-amino acid peptide possessing NMDA receptor antagonist activity that has been isolated from adrenal medullary tissue. The present study examined the ability of stable analog [Ser1]histogranin to reduce abnormal pain-related behaviors induced in rats by direct activation of spinal NMDA receptors. The intrathecal injection of NMDA (5.0, 10.0, 20.0 nmol) produced significant thermal and mechanical hyperalgesia and tactile allodynia in a dose-related fashion. [Ser1]histogranin injected intrathecally prior to NMDA injections dose dependently attenuated or completely blocked hyperalgesia and allodynia. In addition, [Ser1]histogranin administration following NMDA-induction of abnormal pain behaviors reversed these effects. These results demonstrate that a naturally derived adrenal medullary neuropeptide can prevent and reverse NMDA-mediated spinal hyperexcitability. The distinct profile and robust activity of [Ser1]histogranin suggest novel alternative approaches in the management of pain and other CNS disorders involving abnormal excitatory neurotransmission.

[Non-insulin dependent diabetes in children and adolescents]

Maturity-onset diabetes of the young (MODY) is a clinically and genetically heterogenous disorder characterized by autosomal dominant inheritance with onset usually before 25 years of age, and a primary defect in glucose-stimulated insulin secretion. Genetic analyses have shown that mutations in at least five different genes can cause MODY. These are the genes encoding the glycolytic enzyme glucokinase, three liver-enriched transcription factors, hepatocyte nuclear factor (HNF)-1 alpha, HNF-1 beta and HNF-4 alpha, and the gene encoding the transcription factor, insulin promoter factor-1 (IPF-1). Patients with MODY3 run a considerable risk of developing diabetic eye disease. MODY2, related to glucokinase deficiency, is a relatively benign disorder which does not usually require insulin. Experiences with the three other MODY forms have so far been restricted to very few families. We present the first Norwegian family with MODY2. Furthermore, a previously published Norwegian family is shown to be MODY3. Subjects who fulfil the criteria of MODY can, by genetic testing, gain information important for prognosis and perhaps also for therapy.

Adrenal medullary transplants attenuate sensorimotor dysfunction in rats with peripheral neuropathy

Previous work in our laboratory has demonstrated that adrenal medullary transplants into the spinal subarachnoid space can alleviate neuropathic pain behaviors. The purpose of this study was to test the possibility that motor, as well as, sensory dysfunction is reduced by adrenal medullary transplants. Peripheral neuropathy was induced by a chronic constriction injury (CCI) of the sciatic nerve of rats. In addition to exaggerated responses to noxious and innocuous stimuli characteristic of peripheral nerve injury, severe impairment of hindpaw placing and grasping reflexes following CCI was observed. Two weeks following CCI, either adrenal medullary or control striated muscle tissue was implanted into the spinal subarachnoid space. Adrenal medullary, but not control transplants, produced significant restoration of hindlimb reflex function in animals with peripheral nerve injury. This was reversed by pretreatment with the alpha-adrenergic antagonist phentolamine, but not the opiate antagonist naloxone, suggesting a role for catecholamines secreted by the implanted cells in reflex recovery. Adrenal medullary transplants also attenuated hyperalgesia and allodynia resulting from nerve injury. These results indicate that adrenal medullary transplants can alleviate sensorimotor dysfunction consequent to peripheral nerve injury.

The influence of xenotransplant immunogenicity and immunosuppression on host MHC expression in the rat CNS

During the early stages following neural transplantation, host immune responses are initiated that are not normally found in the CNS including the induction of major histocompatibility antigens (MHC I and II). Previous laboratory findings have demonstrated prolonged survival of bovine chromaffin cells (BCC) in the rat CNS following transient immunosuppression with cyclosporin A (CSA) providing chromaffin cells are isolated from highly immunogenic passenger cells. To assess the influence of passenger and chromaffin cells on host MHC I and II expression, either BCC, nonchromaffin cell adrenal constituents (NCC), or adrenal medullary endothelial cells (EC) were implanted into the host. At 2 weeks postimplantation, robust BCC survival was obtained in CSA-treated animals. This correlated with low expression of MHC I at the host-graft border and the virtual absence of MHC II. Good BCC survival with reduced MHC I expression only was seen at 6 weeks postimplantation in animals transiently immunosuppressed (4 weeks). In contrast, poor survival was seen in the EC group (even with CSA treatment). In addition, marked MHC I and II expression was found in and around these grafts at 2 weeks, and was particularly intense in EC implanted animals. The results of this study suggest that nonchromaffin passenger cells in BCC preparations, most notably endothelial cells, can induce strong immune responses even in the presence of immunosuppression. Based on MHC staining, removal of these passenger cells can reduce host responses and improve long term survival of xenogeneic chromaffin cells in the CNS.

Suppression of neuropathic pain by a naturally-derived peptide with NMDA antagonist activity

Chronic pain may result from hyperexcitability following activation of spinal NMDA receptors. A naturally-derived mammalian peptide, histogranin, may possess NMDA antagonist activity. This study explored the possibility that stable analog [Ser1]Histogranin (SHG) could reduce chronic pain. Neuropathic pain was induced using the chronic constriction injury model (CCI). Intrathecal injection of SHG markedly attenuated the hyperalgesia and allodynia resulting from CCI, nearly normalizing responses. These results suggest that the natural peptide histogranin may be a novel adjunct in neuropathic pain management.

Xenogeneic adrenal medulla graft rejection rather than survival leads to increased rat striatal tyrosine hydroxylase immunoreactivity

Adrenal medulla has often been used as a donor tissue for transplantation into damaged central nervous system, with functional effects ranging from very good to nonexistent. The grafts have often been associated with morphological evidence of stimulated recipient dopaminergic fiber plasticity. The interpretation of these results has been difficult due to variable but mostly poor graft survival. The present study combines two experiments which evaluated the effects of intrastriatal xenogeneic adrenal medullary cell suspension grafts on rat recipients. First, bovine adrenal medulla cell suspension grafts of various compositions were tested for their functional and morphologic effects on immunosuppressed hemiparkinsonian rats. In the second experiment, graft rejection was allowed to occur in half of the rats in order to determine a possible contribution of the inflammatory/immune response to increased dopaminergic fiber plasticity of the recipient. At 28 days, grafts of all cell types survived well in immunosuppressed rats, but none of the grafted cell types was associated with either an amelioration of amphetamine-induced rotation or an increase in striatal tyrosine hydroxylase immunoreactivity around the graft site. The latter phenomenon was observed only in the nonimmunosuppressed rats with rejected grafts. Our findings strongly support the role of inflammatory/immune response to grafting in stimulating dopaminergic fiber plasticity and in the appearance of sprouting.

A natural peptide with NMDA inhibitory activity reduces tonic pain in the formalin model

The aim of this study was to assess whether a natural peptide, histogranin, isolated from chromaffin cells and possessing NMDA receptor inhibitory activity, could reduce tonic pain. Rats received intrathecal injections of the stable analog [Ser1]histogranin (SHG), prior to induction of the formalin response. SHG markedly suppressed the second tonic phase of the formalin response compared with saline vehicle. A U-shaped dose-response curve was obtained. SHG had no effect on phase 1 acute pain responses. These findings indicate that SHG acts in a similar fashion as other, non-peptide, NMDA antagonists in suppressing tonic, but not acute pain. The presence of the natural peptide in chromaffin cells may contribute to the analgesic effects of adrenal medullary implants.

Attenuation of formalin pain responses in the rat by adrenal medullary transplants in the spinal subarachnoid space

Previous reports have indicated that the implantation of adrenal medullary chromaffin cells into the spinal subarachnoid space can reduce both acute and chronic pain in several animal models. Recent findings suggest that acute and chronic pain alleviation may be mediated by distinct mechanisms. Since the formalin response is composed of an acute and tonic phase which can be pharmacologically distinguished, the ability of adrenal medullary implants to alter these responses was assessed. In rats with adrenal medullary transplants, both phases of the formalin response were attenuated, in contrast to control implanted animals. Suppression of the acute phase by adrenal medullary implants was reversed by the opiate antagonist naloxone, and partially reversed by the alpha-adrenergic antagonist phentolamine, suggesting that opioid peptides and catecholamines released by the implanted chromaffin cells contribute to the observed antinociception. However, neither antagonist altered the antinociceptive effects of adrenal medullary implants on the tonic phase of the formalin response. These results indicate that adrenal medullary implants in the spinal subarachnoid space alleviate acute and tonic pain via distinct pharmacologic mechanisms.

Loss of GABA-immunoreactivity in the spinal dorsal horn of rats with peripheral nerve injury and promotion of recovery by adrenal medullary grafts

Abnormal pain-related behaviour that accompanies peripheral nerve injury may be the result of altered spinal neuronal function. The long-term loss of inhibitory function by GABA neurons in particular may be a mechanism by which abnormal neural hyperactivity occurs, leading to exaggerated sensory processing following nerve injury. In order to assess this, changes in spinal GABA immunoreactivity at several time points following constriction nerve injury were quantified in parallel with behavioural assessments of abnormal sensory responses to noxious and innocuous stimuli. In addition, the effects of spinal adrenal medullary transplants were determined since previous findings have demonstrated alleviation of behavioural pain symptoms by such transplants. In response to unilateral sciatic nerve injury, GABAergic profiles normally found in lumbar dorsal horn laminae I-III significantly decreased. The decrease was apparent three days following ligation, particularly on the side ipsilateral to the nerve injury. By two weeks, no GABAergic profiles could be seen, with the deficit appearing in the spinal dorsal horn both ipsilateral and contralateral to the unilateral peripheral nerve injury. Marked decreases in GABA-immunoreactive profiles persisted for at least up to five weeks post-injury, with partial restoration occurring by seven weeks. However, even at seven weeks, losses in GABA-immunoreactive profiles persisted in the dorsal horn ipsilateral to peripheral nerve injury. These findings were comparable in animals receiving control striated muscle transplants. In contrast, adrenal medullary transplants markedly reduced the loss in GABA-immunoreactive profiles at all time-points examined. In addition, GABA-immunoreactive profile levels were normalized near that of intact animals by five to seven weeks following nerve injury in animals with adrenal medullary transplants. Parallel improvements in sensory responses to innocuous and noxious stimuli were also observed in these animals. The results of this study indicate that peripheral nerve injury can result in severe losses in spinal inhibitory mechanisms, possibly leading to exaggerated sensory processes in persistent pain states. In addition, adrenal medullary transplants may provide a neuroprotective function in promoting recovery and improving long-term survival of GABAergic neurons in the spinal dorsal horn which have been damaged by excitotoxic injury.

Alterations in rat spinal cord cGMP by peripheral nerve injury and adrenal medullary transplantation

Adrenal medullary chromaffin cells implanted into the spinal subarachnoid space can reduce abnormal pain-related responses in chronic pain models. Persistent pain is thought to involve the activation of N-methyl-D-aspartate (NMDA) receptors and subsequent production of nitric oxide (NO) and cyclic guanosine 3',5'-monophosphate (cGMP). Changes in dorsal horn levels of cGMP in the rat were determined in conjunction with alterations in pain behaviors following peripheral nerve injury and adrenal medullary transplantation. Results indicated increased spinal cGMP levels in parallel with thermal and mechanical hyperalgesia and tactile allodynia consequent to chronic constriction injury of the sciatic nerve in rats. Adrenal medullary, but not control transplants, attenuated the hyperalgesia and allodynia and decreased spinal cGMP content. These results suggest that adrenal medullary transplants may reduce abnormal pain by intervention in the spinal NMDA-NO cascade.

Cells expressing preproenkephalin mRNA in the rat pineal gland are not serotonin-producing pinealocytes: evidence using in situ hybridization combined with immunocytochemistry for serotonin

1. Preproenkephalin (PPEnk) mRNA expressing cells have been identified in rat pineal gland using radioactive in situ hybridization histochemistry. 2. Approximately 7% of the cells in the pineal gland (7.5 +/- 0.86, mean +/- 95% CI) express PPEnk mRNA. These cells are distributed throughout the pineal as either scattered single cells or small groups of cells with large round or oval nuclei. 3. Using in situ hybridization combined with ABC immunocytochemistry for serotonin (5-HT) in the same pineal sections, the PPEnk mRNA labeling cells are found not to be serotonin-immunoreactive cells. These data indicate that the PPEnk mRNA is expressed in a certain discrete subpopulation of cells in the rat pineal gland and these cells are not serotonin-producing pinealocytes. 4. The physiologic role of PPEnk-derived peptides in the pineal remains unknown. It is possible that these peptides either are synthesized and secreted as hormones or act as pineal paracrine signals.

Adrenal medullary implants reduce transsynaptic degeneration in the spinal cord of rats following chronic constriction nerve injury

Peripheral nerve injury causes abnormal sensory processing, possibly due in part to neuroplastic changes in the CNS. Following chronic constriction injury of the sciatic nerve, transsynaptic degeneration is suggested by the presence of "dark neurons" found in superficial laminae of spinal cord. Previous studies in our laboratory have shown that grafts of adrenal medullary cells into the spinal subarachnoid space can reduce abnormal pain due to peripheral nerve injury. A possible mechanism for these beneficial effects is the reduction or interruption of excitotoxic events that lead to pathological CNS changes. In order to examine this, 2 weeks after unilateral sciatic nerve ligation using a chronic constriction injury model, animals received either adrenal medullary or control striated muscle tissue implanted in the lumbar subarachnoid space. Control striated muscle-transplanted animals with nerve injury displayed thermal hyperalgesia and elevated numbers of dark neurons in the superficial dorsal horn, compared to intact animals. These dark neurons were increased bilaterally, but predominantly ipsilaterally, to nerve injury. In contrast, in animals with adrenal medullary transplants, reduced numbers of dark neurons were found in parallel with reduced hyperalgesia. The low numbers of dark neurons in these animals were similar to age-matched unoperated controls. Two months after nerve ligation, dark neurons were not found in animals with nerve injury, although abnormal ruffled-appearing neurons were still present in untransplanted animals, suggesting partial recovery of damaged spinal neurons. The results of this study suggest that spinal adrenal medullary transplants can attenuate the neuropathological events perpetuating nerve-injury-induced pain by enhancing recovery of spinal neurons from excitotoxic insult.

Update on cellular transplantation into the CNS as a novel therapy for chronic pain

The transplantation of cells that secrete neuroactive substances with analgesic properties into the CNS is a novel method that challenges current approaches in treating chronic pain. This review covers pre-clinical and clinical studies from both allogeneic and xenogeneic sources. One cell source that has been utilized successfully is the adrenal chromaffin cell, since such cells constitutively release catecholamines, opioid peptides, and neurotrophic factors; release can be augmented with nicotine. Other graft sources include AtT-20 and B-16 cell lines which release enkephalins and catecholamines, respectively. For grafting in rodents, adrenal medullary tissue pieces are transplanted to the subarachnoid space. Chromaffin cell transplants can decrease pain sensitivity in normal rats using standard acute pain tests (paw-pinch, hot-plate, and tail-flick). In addition, transplants can restore normal pain thresholds in rodent models of chronic pain (formalin, adjuvant-induced arthritis, and sciatic-nerve tie) which closely similate the pathologies of human chronic pain conditions. Xenografts have been studied due to concerns that future application for human pain may be limited by donor availability. Despite immune privileges of the CNS, xenografts require at least short-term immunosuppression to obtain a viable graft. Cell encapsulation is one method of sustaining a xenograft (in rat and human hosts) while circumventing the need for immunosuppression. Clinical studies have been initiated for terminal cancer patients with promising results as assessed by markedly reduced narcotic intake, visual analog scale ratings, and increased CSF levels of catecholamines and met-enkephalin.

Modulation of NMDA receptor expression in the rat spinal cord by peripheral nerve injury and adrenal medullary grafting

Excessive activation of N-methyl-D-aspartate (NMDA) receptors in the spinal cord consequent to peripheral injury has been implicated in the initiation of neuropathologic events leading to a state of chronic hyperexcitability and persistence of exaggerated sensory processing. In other CNS disease or injury states, NMDA-mediated neurotoxic damage is associated with a loss of NMDA receptors, and outcome may be improved by agents reducing NMDA activation. Previous findings in our laboratory have demonstrated that the transplantation of adrenal medullary tissue into the spinal subarachnoid space can alleviate sensory abnormalities and reduce the induction of a putative nitric oxide synthase consequent to peripheral nerve injury. In order to determine changes in NMDA receptor expression in the spinal cord following peripheral nerve injury and adrenal medullary grafting, NMDA receptor binding using a high-affinity competitive NMDA receptor antagonist, CGP-39653, and NMDAR1 subunit distribution using immunocytochemistry were investigated. Two weeks following peripheral nerve injury by loose ligation of the right sciatic nerve, either adrenal medullary or striated muscle (control) tissue pieces were implanted in the spinal subarachnoid space. Binding studies revealed a marked reduction in [3H]CGP-39653 binding at L4-L5 levels ipsilateral to peripheral nerve injury in control transplanted animals. In contrast, NMDA binding was normalized in adrenal medullary grafted animals. In addition, NMDAR1 immunoreactivity was reduced in both the dorsal horn neuropil and motor neurons of the ventral horn in animals with peripheral nerve injury, while levels in adrenal medullary grafted animals appeared similar to intact controls. These results suggest that adrenal medullary transplants reduce abnormal sensory processing resulting from peripheral injury by intervening in the spinal NMDA-excitotoxicity cascade.

Adrenal medullary grafts suppress c-fos induction in spinal neurons of arthritic rats

Expression of immediate-early genes such as c-fos is thought to reflect patterns of neuronal activity in the central nervous system. Prolonged increases in Fos-protein-like-immunoreactivity (FOS-LI) are seen in the dorsal horn of adjuvant arthritic rats, and parallel increased pain behavior. Grafts of adrenal medullary, but not control tissue, into the spinal subarachnoid space reduce pain behavior and suppress the induction of spinal Fos-LI in arthritic rats. This reduction is particularly marked in superficial laminae (I-II), but is also significant in deeper laminae (III-IV and V-VI). The results of this study suggest that adrenal medullary transplants reduce spinal cord hyperactivation consequent to painful peripheral inflammation.

Beta-adrenergic receptor subtypes in stress-induced behavioral depression

The purpose of this study was to examine the role of beta-adrenergic receptors in an animal model of stress-induced behavioral depression. beta-Adrenergic receptors in several brain regions and leukocytes of rats were determined by receptor binding techniques using 125I-cyanopindolol (cyp) as ligand and propranolol as displacer for total beta-adrenergic receptors, and ICI 86,406 for beta 1- and ICI 118,551 for beta 2-adrenergic receptors. We observed that the maximum number of binding sites (Bmax) and the apparent dissociation constant (Kd) of 125I-cyp binding to total beta-adrenergic receptors were increased in hippocampus of stressed rats with escape deficits (48 h after training) as compared to control rats. This increase was due to an increase in Bmax and Kd of 125I-cyp binding to beta 1-adrenergic receptors but not to beta 2-adrenergic receptors. There was no significant difference in beta 1-adrenergic receptors in cortex and cerebellum or beta 2-adrenergic receptors in hippocampus, cortex, cerebellum, or leukocytes of stressed (48 h after training) rats with escape deficits as compared to control rats. Interestingly, it was observed that beta 1- and beta 2-adrenergic receptors in various brain regions (cortex, cerebellum, and hippocampus) and beta 2-adrenergic receptors in leukocytes of stressed rats (10 days after training) were not significantly different from control rats, although escape deficits were still present. These results suggest that abnormalities in adrenergic neurotransmission are associated with an upregulation of beta 1-adrenergic receptors, which in turn may be involved in the early stages of behavioral deficits caused by uncontrollable shock.

Attenuation of NMDA-induced spinal hypersensitivity by adrenal medullary transplants

Abnormal sensory hyperexcitability consequent to peripheral injury most likely involves activation of N-methyl-D-aspartate (NMDA) receptors in the spinal cord. This activation may lead to a cascade of neuroplastic events resulting in the exaggeration of sensory responses and the persistence of pathological pain states. Recent studies in our laboratory have demonstrated that the transplantation of adrenal medullary cells into the spinal subarachnoid space can alleviate pathological pain symptoms, possibly by reducing spinal hyperexcitability. The purpose of this study was to assess spinal NMDA activation-induced hypersensitivity to noxious and innocuous stimuli, and determine whether adrenal medullary transplants can intervene favorably to reduce these responses. Animals with either adrenal medullary or control transplants were injected intrathecally with several doses of NMDA, and responses to sensory stimuli were determined over time. NMDA at all doses tested (1-50 nmol) produced significant thermal and mechanical hyperalgesia and tactile allodynia in control transplanted animals, with peak severity at 30 min post-injection. In contrast, both the severity and duration of these exaggerated sensory responses were markedly reduced in animals with adrenal medullary transplants. To assess a possible contribution of released opioid peptides and catecholamines from the transplanted chromaffin cells, animals were pretreated with opiate antagonist naloxone or alpha-adrenergic antagonist phentolamine. While naloxone was ineffective, the phentolamine partially attenuated, but did not completely abolish, the antinociceptive effects of the transplants. The results of these studies demonstrate that adrenal medullary grafts can reduce hypersensitivity responses to NMDA-mediated activation via alpha-adrenergic modulation in addition to other neuroprotective mechanisms.

Pharmacologic specificity of antidepressive activity by monoaminergic neural transplants

Previous studies in our laboratory have demonstrated the ability of monoaminergic transplants in the rat frontal cortex to produce antidepressive activity in both the learned helplessness model and the forced swimming test, as well as to increase monoamine levels in the implanted frontal cortex. These findings implicate increased cortical levels of norepinephrine (NE) and serotonin (5-HT) in the antidepressive activity of monoaminergic transplants. The goal of the present study was to characterize the pharmacologic mechanisms involved in the monoaminergic graft-induced antidepressive activity. Immobility scores in the forced swimming test (FST) were assessed after transplantation of 5-HT-containing pineal gland tissue, NE-containing adrenal medullary tissue, a combination of both tissues, or sciatic nerve (control) into the rat frontal cortex and compared to non-transplanted and chronic imipramine-treated rats. Monoaminergic transplants and imipramine treatment significantly reduced immobility scores in the FST in contrast to control transplanted or untreated animals. All groups were assessed pharmacologically with the adrenergic antagonists phentolamine (alpha) and propranolol (beta), and serotonergic antagonists metergoline (5-HT1/5-HT2) and pirenperone (5-HT2). Serotonergic antagonists, particularly the 5HT2 antagonist, blocked the reduction in FST immobility induced by the pineal implants. Adrenergic antagonists not only blocked FST immobility reductions in adrenal medullary grafted animals, but over-compensated for the adrenal transplants, producing a large increase in immobility. The FST reduction induced by pineal and adrenal cografts was blocked by all four monoaminergic antagonists. FST immobility scores in control transplanted and non-transplanted animals were not altered by any of the antagonists. The immobility reduction produced by chronic imipramine treatment was blocked significantly only by propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Transplantation of human chromaffin cells for control of intractable cancer pain

Adrenal medullary chromaffin cells produce high levels of endogenous opioid peptides. Recent data suggest that transplantation injected locally into the spinal subarachnoid space reduced intractable malignant pain. In order to determine the feasibility, the efficacy and the risks of using adrenal medullary tissue for control of irreducible pain, we have developed a transplantation protocol on cancer pain patients selected when they required chronic intrathecal injection of morphine and progressively increasing doses to maintain the level of analgesic effects. At the present time, our clinical trial involves 8 patients. We report here our initial results (mean follow-up: 5 months). The various data collected before and after the intrathecal administration of chromaffin cells included: 1) Pain evaluation over time, with concomitant narcotic intake, 2) CSF sampling through an implanted access port to determine the following biological parameters: biochemical assay for opioid peptides, cell count and phenotyping of lymphocytes, 3) peripheral blood samples for lymphocyte typing. The results confirm the efficacy of adrenal medullary transplantation into spinal CSF for controlling irreducible cancer pain. Complementary intrathecal and oral morphine were totally stopped in 2 cases and stabilized in 5 others. It seems essential to have an important volume of grafted tissue to achieve analgesia with high levels of metenkephalin in CSF. A progressive decrease in metenkephalin release was observed from 2 to 4 months after the transplantation. Two patients with a long-term follow-up (8 and 12 months) needed another intrathecal chromaffin cell graft.

Chromaffin cell xenografts in the rat neocortex can produce antidepressive activity in the forced swimming test

Adrenal medullary allografts, as well as other monoaminergic tissues, have been demonstrated in our laboratory to increase antidepressive activity when transplanted into the frontal neocortex of rats. Refinement in the optimal parameters for xenograft viability has indicated that isolated bovine chromaffin cells may be an improved source of graft donor tissue. The aim of the present study was to determine whether isolated bovine chromaffin cell grafts to the rat frontal neocortex could provide an alternative source of catecholamines for antidepressant activity. Isolated bovine chromaffin cells, isolated bovine fibroblasts, or an equal volume of vehicle were unilaterally implanted into the right or left frontal cortex or right visual cortex. All rats were assessed before and 6 weeks after transplantation using the forced swimming test, a popular measure of antidepressant activity. Bovine chromaffin cell grafts in either the right or left frontal cortex produced significant increases in antidepressant activity compared to grafts of bovine fibroblasts and sham-operated or nontransplanted rats. In contrast, bovine chromaffin cells transplanted to the visual cortex did not affect antidepressant activity. Bovine fibroblast grafts in the frontal cortex also induced slight increases in antidepressant activity, although significantly less than chromaffin cell grafts. Morphological analysis revealed robust survival of tyrosine hydroxylase-positive chromaffin cells that retained their in situ ultrastructure and occasionally formed synaptic connections with the host parenchyma. These results suggest that xenografted isolated bovine chromaffin cells can provide a viable source of catecholamines for antidepressive activity.

In vivo release of catecholamines from xenogeneic chromaffin cell grafts with antidepressive activity

Previous studies in our laboratory have demonstrated that allografts of adrenal medullary tissue and xenografts of isolated bovine chromaffin cells to the rat frontal cortex can increase antidepressive activity in two separate animal models. Biochemical and pharmacological evidence suggest that the most likely mechanism of these antidepressive effects is via local release of catecholamines into the surrounding cortical parenchyma. The aim of the present study was to directly characterize the antidepressive mechanism of chromaffin cell xenografts by utilizing in vivo microdialysis to measure extracellular catecholamine levels from bovine chromaffin cell and control implanted rat frontal cortex. Following transplantation, only bovine chromaffin cell grafted rats displayed significant increases in antidepressive activity, as assessed by the forced swimming test, compared to rats with grafts of bovine adrenal medullary fibroblasts or nontransplanted rats. In vivo microdialysis results revealed remarkably elevated levels of epinephrine (EPI) and norepinephrine (NE), but not dopamine, in dialysates from bovine chromaffin cell-transplanted frontal cortex. The most likely source of these enhanced EPI and NE levels is the grafted xenogeneic chromaffin cells. The results of this study directly demonstrate that xenografts of bovine chromaffin cells to the rat frontal cortex provide a releasable pool of catecholamines for antidepressive activity.

Transplantation of encapsulated bovine chromaffin cells in the sheep subarachnoid space: a preclinical study for the treatment of cancer pain

Chromaffin cells have been shown to release a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides. The allogeneic transplantation of chromaffin cells in the subarachnoid space has been shown to alleviate pain in various rodent models and possibly in terminal cancer patients. Because of the shortage of human cadaver donor tissue, we are investigating the possibility of transplanting xenogeneic cells in polymer capsules. In this technique, cells are surrounded by a permselective synthetic membrane whose pores are suitably sized to allow diffusion of nutrients, neurotransmitters and growth factors, but restrict the diffusion of the large molecules of the immune system and prevent contact with immunocompetent cells. The encapsulation technique therefore allows transplantation of xenogeneic tissue between species as well as retrieval of transplanted cells. Previously we have reported that encapsulated bovine chromaffin cells survive and alleviate pain in various rodent models. The purpose of the present study was to assess the feasibility of implanting a human sized device in a large animal model. Adrenals from 5 calves were surgically removed; chromaffin cells were isolated from these glands using a collagenase-based digestion-filtration technique. Cells were loaded into acrylic-based tubular (5 cm long, 920 microns wide) permselective capsules attached to silicone tethers. The capsules were maintained in vitro for at least 7 days following the encapsulation procedure. Nicotine evoked release was analyzed in a defined subgroup from each batch. One capsule was then implanted using a guiding cannula system in the lumbar subarachnoid space of each sheep for 4 (n = 5) and 8 (n = 1) wk. All capsules were retrieved intact by gentle pulling on the silicone tether. Except for one capsule, the evoked catecholamine release of the retrieved capsules was in the same range as that of other capsules from the same cohort that had been maintained in vitro. All retrieved capsules were devoid of host cell reaction. Clusters of viable cells dispersed in an alginate immobilizing matrix were observed throughout all the implanted capsules. This study demonstrates the feasibility of transplanting functional encapsulated xenogeneic chromaffin cells into the cerebrospinal fluid of a large animal model using a capsule of appropriate dimensions for human implants. We believe that these results suggest the appropriateness of human clinical trials in patients suffering from refractory terminal cancer pain.