Optical power profiles and aberrations of a non-diffractive wavefront-shaping extended depth of focus intraocular lens.

PURPOSE: This study is to evaluate the optical characteristics of a non-diffractive wavefront-shaping intraocular lens which incorporates surface refractive modifications for shaping the wavefront in order to achieve extended depth of focus (EDoF) and to assess whether the nominal power of this IOL influences the attainable add power. METHODS: A commercially available optical bench NIMO TR1504 device (LAMBDA-X, Nivelles, Belgium) was employed to obtain full optical characterization of three non-diffractive EDoF intraocular lenses with + 10 D, + 20 D, and + 30 D powers. After NIMO measurements, data were computed using a custom-made MATLAB program (Mathworks, Inc., Natick, MA, USA) to evaluate the optical quality functions, such as the point spread function (PSF), wavefront profiles, and modulation transfer function (MTF) for two pupil sizes: 3 mm and 4.0 mm. RESULTS: The non-diffractive EDoF intraocular lens showed a central serrated power profile behavior with additions of + 2.00 to + 2.50 D over the nominal power. Higher order aberrations were found to be driven mainly by the spherical aberration, with almost null comatic influence. Optical quality metrics showed good values, better for a 3 mm pupil compared to a 4.5 mm one, as expected. The three IOL powers tested showed a very similar behavior in terms of power and aberrometric profiles, with minimal to null differences related to the nominal power. CONCLUSION: The non-diffractive wavefront-shaping EDoF intraocular lens achieves a near addition up to + 2.50 D aiming for an extended range of vision, almost independently of the base power.

Vitamin E (α-Tocopherol) Does Not Ameliorate the Toxic Effect of Bisphenol S on the Metabolic Analytes and Pancreas Histoarchitecture of Diabetic Rats.

This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.

Excessive Consumption Hibiscus sabdariffa L. Increases Inflammation and Blood Pressure in Male Wistar Rats via High Antioxidant Capacity: The Preliminary Findings.

Hibiscus sabdariffa L. (HSL) has high amounts of antioxidants and many beneficial effects in several pathologies. However, few studies describe the possible harmful effects of high concentrations of HSL. Here we evaluate the effect of excessive and chronic consumption of infusions with different percentages of HSL on some oxidative stress markers in serum, and the possible association with inflammation and increased systolic blood pressure (SBP), in healthy rats. A total of 32 male Wistar rats were used to form 4 groups with 8 animals each. Group 1 control (drinking tap water), group 2, 3 and 4, drinking water supplemented with 15, 30 and 60 g/L of HSL calyxes respectively. SBP was evaluated and determinations in serum of the NO3-/NO2- ratio, glutathione (GSH), total antioxidant capacity (TAC), selenium (Se), TNF-α, IL-1α/IL-1F1, IL-1ß, IL-10, extracellular superoxide dismutase (EcSOD), thioredoxin reductase (TrxR) and glutathione peroxidase (GPx) activities, were evaluated. The SBP (p = 0.01), GPx activity, GSH, TAC, Se, TNF-α and EcSOD activities (p ≤ 0.001) and IL-1α/IL-1F1, IL-1ß, TrxR and NO3-/NO2- (p ≤ 0.05), were increased but IL-10 (p < 0.001) was decreased in rats that consumed the 3 and 6% HSL infusions. The excessive and chronic consumption of HSL may increase the TAC that could lead to a proinflammatory state which is associated with hypertension.

Erratum: Hindi, N., et al. Trabectedin Plus Radiotherapy for Advanced Soft-Tissue Sarcoma: Experience in Forty Patients Treated at a Sarcoma Reference Center. Cancers 2020, 12, 3740.

The authors noticed that content of "Conflicts of Interest" in the original version [...].

Trabectedin Plus Radiotherapy for Advanced Soft-Tissue Sarcoma: Experience in Forty Patients Treated at a Sarcoma Reference Center.

Symptomatic control and tumoral shrinkage is an unmet need in advanced soft-tissue sarcoma (STS) patients beyond first-line. The combination of trabectedin and radiotherapy showed activity in a recently reported clinical trial in this setting. This retrospective series aims to analyze our experience with the same regimen in the real-life setting. We retrospectively reviewed advanced sarcoma patients treated with trabectedin concomitantly with radiotherapy with palliative intent. Growth-modulation index (GMI) was calculated as a surrogate of efficacy. Forty metastatic patients were analyzed. According to RECIST, there was one (2.5%) complete response, 12 (30%) partial responses, 18 (45%) disease stabilizations, and nine (22.5%) progressions. After a median follow-up of 15 months (range 2-38), median progression-free survival (PFS) and overall survival (OS) were 7.5 months (95% CI 2.8-12.2) and 23.5 months (95% CI 1.1-45.8), respectively. Median GMI was 1.42 (range 0.19-23.76), and in 16 (53%) patients, it was >1.33. In patients with GMI >1.33, median OS was significantly longer than in those with GMI 0-1.33 (median OS 52.1 months (95% CI not reached) vs. 8.9 months (95% CI 6.3-11.6), p = 0.028). The combination of trabectedin plus radiotherapy is an active therapeutic option in patients with advanced STS, especially when tumor shrinkage for symptomatic relief is needed.

Mesenchymal Stem/Stromal Cells Derived from Dental Tissues: A Comparative In Vitro Evaluation of Their Immunoregulatory Properties Against T cells.

Bone marrow mesenchymal stem/stromal cells (BM-MSCs) have immunoregulatory properties and have been used as immune regulators for the treatment of graft-versus-host disease (GVHD). Human dental tissue mesenchymal stem cells (DT-MSCs) constitute an attractive alternative to BM-MSCs for potential clinical applications because of their accessibility and easy preparation. The aim of this in vitro study was to compare MSCs from dental pulp (DP-MSCs), gingival tissue (G-MSCs), and periodontal ligament (PDL-MSCs) in terms of their immunosuppressive properties against lymphoid cell populations enriched for CD3+ T cells to determine which MSCs would be the most appropriate for in vivo immunoregulatory applications. BM-MSCs were included as the gold standard. Our results demonstrated, in vitro, that MSCs from DP, G, and PDL showed immunoregulatory properties similar to those from BM, in terms of the cellular proliferation inhibition of both CD4+- and CD8+-activated T-cells. This reduced proliferation in cell co-cultures correlated with the production of interferon-γ and tumor necrosis factor alpha (TNF-α) and the upregulation of programmed death ligand 1 (PD-L1) in MSCs and cytotoxic T-cell-associated Ag-4 (CTLA-4) in T-cells and increased interleukin-10 and prostaglandin E2 production. Interestingly, we observed differences in the production of cytokines and surface and secreted molecules that may participate in T-cell immunosuppression in co-cultures in the presence of DT-MSCs compared with BM-MSCs. Importantly, MSCs from four sources favored the generation of T-cell subsets displaying the regulatory phenotypes CD4+CD25+Foxp3+ and CD4+CD25+CTLA-4+. Our results in vitro indicate that, in addition to BM-MSCs, MSCs from all of the dental sources analyzed in this study might be candidates for future therapeutic applications.

Intra-Abdominal Fat Adipocyte Hypertrophy through a Progressive Alteration of Lipolysis and Lipogenesis in Metabolic Syndrome Rats.

This study evaluates the progressive participation of enzymes involved in lipolysis and lipogenesis, leading to adipocyte hypertrophy in a metabolic syndrome (MS) rat model caused by chronic consumption of 30% sucrose in drinking water. A total of 70 male Wistar rats were divided into two groups: C and MS. Each of these groups were then subdivided into five groups which were sacrificed as paired groups every month from the beginning of the treatment until 5 months. The intra-abdominal fat was dissected, and the adipocytes were extracted. Lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), protein kinases A (PKA), and perilipin A expressions were determined. The LPL and HSL activities were evaluated by spectrophotometry. Histological staining was performed in adipose tissue. Significant increases were observed in blood pressure, HOMA-IR, leptin, triglycerides, insulin, intra-abdominal fat, and number of fat cells per field (p = 0.001) and in advanced glycosylation products, adipocyte area, LPL, HSL activities and/or expression (p ≤ 0.01) in the MS groups progressively from the third month onward. Lipogenesis and lipolysis were increased by LPL activity and HSL activity and/or expression. This was associated with hyperinsulinemia and release of non-esterified fatty acids causing a positive feedback loop that contributes to the development of adipocyte hypertrophy.

Effect of oophorosalpingo-hysterectomy on serum antioxidant enzymes in female dogs.

There are few studies evaluating the oxidant-antioxidant status after oophorosalpingohysterectomy (OSH) in female dogs. Here we determined the effect of OSH on antioxidant enzymes in serum, and quantified morphological changes in subcutaneous adipocytes. Lateral OSH was performed in 12 female dogs. The concentration of 17ß-estradiol (17ß-E2), the activities of extracellular superoxide dismutase (SOD-ec), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) were determined. Glutathione (GSH), glutathione disulfide (GSSG), lipid peroxidation (LPO), total antioxidant capacity (TAC), carbonylation and vitamin C were measured in serum. Subcutaneous adipose tissue was obtained to determine morphological changes and cell number, under basal conditions and six months after OSH. The SOD-ec, GPx and GST activities increased significantly (p ≤ 0.05), LPO, carbonylation and GSSG also increased. GSH and vitamin C decreased (p = 0.03). 17ß-E2 tended to decrease six months after OSH. Hypertrophy of subcutaneous adipocytes was observed after OSH from the first month and was accentuated after six months (p = 0.001). The results suggest that 17ß-E2 decreases after OSH and alters the antioxidant enzyme activities in serum thus, redox balance is altered. These changes are associated with an increase in body weight and hypertrophy of subcutaneous adipose tissue.

Efficacy of dapsone administered alone or in combination with diazepam to inhibit status epilepticus in rats.

Status epilepticus (SE) is a serious medical condition, as it may trigger epileptogenesis. SE produces continuous generalized seizures resulting in irreversible brain damage. Therefore, the use of neuroprotective agents to prevent cell damage, may reduce the impact of SE. The use of diazepam (DZP), has shown limited neuroprotective effect in SE patients. According to previous reports, dapsone (DDS) is able to reduce both cell damage and seizures, when administered 30 min before the onset of seizures. This study is aimed to evaluate the ability of DDS, alone or in combination with DZP starting their administration once the SE is onset to evaluate the control of seizures in rats. Results showed a reduced convulsive electrical activity after 30 min, 1 and 2 h after SE induced by kainic acid (KA) administration, in the animals treated with DZP alone or in combination with DDS. At 24 h, we observed electrical activity similar to baseline in all groups receiving treatment. The animals treated with DDS and DZP alone or in combination showed an increase in the number of viable pyramidal cells but only the combination showed a lower number of damaged pyramidal neurons of hippocampal CA3. In conclusion, DDS plus DZP was able to control SE and to prevent SE-induced damage, when administered in combination with DZP. As DDS is already in use for patients with leprosy, that combination may be a safe, good option for human cases of SE.

Activation of Hes1 and Msx1 in Transgenic Mouse Embryonic Stem Cells Increases Differentiation into Neural Crest Derivatives.

The neural crest (NC) comprises a multipotent cell population that produces peripheral neurons, cartilage, and smooth muscle cells, among other phenotypes. The participation of Hes1 and Msx1 when expressed in mouse embryonic stem cells (mESCs) undergoing NC differentiation is unexplored. In this work, we generated stable mESCs transfected with constructs encoding chimeric proteins in which the ligand binding domain of glucocorticoid receptor (GR), which is translocated to the nucleus by dexamethasone addition, is fused to either Hes1 (HGR) or Msx1 (MGR), as well as double-transgenic cells (HGR+MGR). These lines continued to express pluripotency markers. Upon NC differentiation, all lines exhibited significantly decreased Sox2 expression and upregulated Sox9, Snai1, and Msx1 expression, indicating NC commitment. Dexamethasone was added to induce nuclear translocation of the chimeric proteins. We found that Collagen IIa transcripts were increased in MGR cells, whereas coactivation of HGR+MGR caused a significant increase in Smooth muscle actin (α-Sma) transcripts. Immunostaining showed that activation in HGR+MGR cells induced higher proportions of ß-TUBULIN III⁺, α-SMA⁺ and COL2A1⁺ cells. These findings indicate that nuclear translocation of MSX-1, alone or in combination with HES-1, produce chondrocyte-like cells, and simultaneous activation of HES-1 and MSX-1 increases the generation of smooth muscle and neuronal cells.

Immunomodulatory effect of Celecoxib on HMGB1/TLR4 pathway in a recurrent seizures model in immature rats.

Epileptic seizures constitute an important problem in pediatric neurology during the developmental period. The frequency and nosological significance of seizures, as well as their association with epileptogenesis, may be related to underlying mechanisms such as neuroinflammation. Those mechanisms of response activate inflammatory molecules induced in the neurons, activated glial cells and endothelial cells via the key HMGB1/TLR4 pathway. In this study, the drug celecoxib (CCX) was used as a blocker of the cyclooxygenase 2 (COX-2) and HMGB1/TLR-4 pathways. The experimental model was implemented in 10-day-old neonatal Sprague Dawley rats to induce recurrent seizures with kainic acid (KA, 1.4 mg/kg). Data were evaluated at early (14 PND) and late (30 PND) time points. The results showed that the CCX and CCX + pentobarbital (PB) groups exhibited a protective effect by significantly increasing the time latency of seizures compared to the KA group at both early (p < 0.01) and late (p < 0.001) times. When the CCX group was compared to the KA group, there was also a significant decrease in the number of HMGB1 and TLR-4 transcripts (p < 0.05) and in COX-2 protein expression (p < 0.05) in the most important areas for seizure generation (the hippocampus and cortex) at both the early and late time points. These results demonstrated that CCX treatment after epileptic seizures has a neuroprotective effect due to the inhibition of proinflammatory proteins and associated signaling pathways and reduces seizure susceptibility. Additionally, the timely intervention of inflammatory pathways will reduce the risk of developing epilepsy in adulthood.

The Morphofunctional Effect of the Transplantation of Bone Marrow Stromal Cells and Predegenerated Peripheral Nerve in Chronic Paraplegic Rat Model via Spinal Cord Transection.

Functional recovery following spinal cord injury (SCI) is limited by poor axonal and cellular regeneration as well as the failure to replace damaged myelin. Employed separately, both the transplantation of the predegenerated peripheral nerve (PPN) and the transplantation of bone marrow stromal cells (BMSCs) have been shown to promote the regrowth and remyelination of the damaged central axons in SCI models of hemisection, transection, and contusion injury. With the aim to test the effects of the combined transplantation of PPN and BMSC on regrowth, remyelination, and locomotor function in an adult rat model of spinal cord (SC) transection, 39 Fischer 344 rats underwent SC transection at T9 level. Four weeks later they were randomly assigned to traumatic spinal cord injury (TSCI) without treatment, TSCI + Fibrin Glue (FG), TSCI + FG + PPN, and TSCI + FG + PPN + BMSCs. Eight weeks after, transplantation was carried out on immunofluorescence and electron microscope studies. The results showed greater axonal regrowth and remyelination in experimental groups TSCI + FG + PPN and TSCI + FG + PPN + BMSCs analyzed with GAP-43, neuritin, and myelin basic protein. It is concluded that the combined treatment of PPN and BMSCs is a favorable strategy for axonal regrowth and remyelination in a chronic SC transection model.

Comparative pharmacokinetics of a new oral long-acting formulation of doxycycline hyclate: A canine clinical trial.

Doxycicline is used in dogs as treatment of several bacterial infections, mycoplasma, chlamydia and rickettsial diseases. However, it requires long treatments and several doses to be effective. The aim of this study was to determine the pharmacokinetics of four formulations of doxycycline hyclate, administered orally, with different proportions of excipients, acrylic acid-polymethacrylate-based matrices, to obtain longer therapeutic levels than conventional formulation. Forty-eight dogs were randomly assigned in five groups to receive a single oral dose (20mg/kg) of doxycycline hyclate without excipients (control) or a long-acting formulation containing doxycycline, acrylic acid polymer, and polymethacrylate in one of the following four proportions: DOX1(1:0.25:0.0035), DOX2(1:0.5:0.0075), DOX3 (1:1:0.015), or DOX4(1:2:0.0225). Temporal profiles of serum concentrations were obtained at several intervals after each treatment. Therapeutic concentrations were observed for 60h for DOX1 and DOX4, 48h for DOX2 and DOX3 and only 24h for DOX-C. None of the pharmacokinetic parameter differed significantly between DOX1 and DOX2 or between DOX3 and DOX4; however, the findings for the control treatment were significantly different compared to all four long-acting formulations. Results indicated that DOX1 had the most adequate pharmacokinetic-pharmacodynamic relationships for a time-dependent drug and had longer release times than did doxycycline alone. However, all four formulations can be effective depend on the minimum effective serum doxycycline concentration of the microorganism being treated. These results suggest that the use of any of these formulations can reduce the frequency of administration, the patient's stress, occurrence of adverse effects and the cost of treatment.

Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.

OBJECTIVE: To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices. ANIMALS: 30 healthy adult dogs. PROCEDURES: In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment. RESULTS: Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 µg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.

Pelvic massive allograft reconstruction after bone tumour resection.

PURPOSE: The purpose of this report was to retrospectively review a series treated with pelvic tumour resection and massive allograft reconstruction, and determine survival of patients and implants, functional results and morbidity of surgical technique. METHODS: From 1999, 33 patients underwent pelvic tumour resection and massive allograft reconstruction. The mean age was 40 years (range, 14-72) and 29 patients had a primary malignant tumour. The resection involved the acetabular area in all but three patients. RESULTS: At a median follow-up of 33 months (range, two-143) four patients had local recurrence. The morbidity was high: five deep infections (15 %), requiring two allograft removal, six hip dislocations (18 %), eight sciatic nerve palsy (24 %), persistent in six cases, and two loosening of the acetabular component. Implant survival was 87.3 % at last follow up. The cumulative overall patient's survival was 41.5 % at five and ten years. The average MSTS functional score was 70 % (range, 54-100 %) when the acetabulum was preserved while it was 61 % (30-100 %) in patients with acetabular resection. CONCLUSION: In conclusion, pelvic allografts represent a valid option for reconstruction after resection of pelvic tumours but due to the associated morbidity, patients should be carefully selected.

Neurosphere cell differentiation to aldynoglia promoted by olfactory ensheathing cell conditioned medium.

Cells from central nervous system with morphology similar to radial glia and properties intermediate between astrocytes and Schwann cells were called growth-promoting glia or aldynoglia. These cells are present in adult brain olfactory bulb, hypothalamus, hypophysis, pineal gland and in the developing brain, and spinal cord (Cameron and Rakic (1991) Glia 4:124-137; Gudiño-Cabrera and Nieto-Sampedro (2000) 30:49-63). We report now that neurosphere cells, abundantly generated from E15 rat or E13 mouse corpus striatum, differentiate to aldynoglia-like cells when plated onto an adhesive substrate, and cultured in the presence of olfactory ensheathing cell conditioned medium, supplemented with EGF and bFGF. The immunophenotype, mRNA expression (microarray and RT-PCR analysis), neurite growth-promoting and ensheathing properties of the cells derived from neurospheres were similar to those of aldynoglia. Neurosphere-derived, aldynoglia-like cells expressed, with respect to neurospheres, very increased levels of GFAP, high levels of nestin and vimentin, extracellular matrix proteins, and inhibitors of the catabolism of those extracellular matrix proteins.

Epilepsia en perros / Canine epilepsy

Idiopathic epilepsy (IE) and other convulsive disorders represent at least 14% of neurological consultations in veterinary medicine. In spite of this, there is a gap in the information usually handled by the small animal clinician, because the pathophysiological aspects of this disease are still not completely understood. Since there is no specific method for diagnosing IE, exclusion criteria are used to reach diagnosis. Although the electroencephalogram (EEG) can provide diagnostic elements, abnormalities in the EEG record are not always found. Pharmacologic treatment options are reduced and not void of ad verse effects. The possibility of encountering IE refractory to antiseizure pharmacological treatment is high and it has been concluded that non pharmacological treatment options should be explored through systematic clinical studies. Up to date, early diagnosis, appropriate pharmacological treatment, owners' education and a combination with non pharmacological options represent the only way to improve prognosis for dogs with IE.

La epilepsia idiopática (EI), así como otras enfermedades convulsivas representan al menos 14% de las consultas neurológicas en la medicina veterinaria. A pesar de esto último, se reconoce que existe un vacío en la información que maneja el clínico especialista en pequeñas especies porque aún no se han elucidado todos los aspectos patofisiológicos de ese padecimiento. Debido a que no existe un método diagnóstico específico, se llega a él por exclusión. Aunque el electroencefalograma (EEG) brinda algunos elementos diagnósticos no siempre se tiene la fortuna de ubicar anormalidades en el registro. Las alternativas terapéuticas farmacológicas son reducidas y no carentes de efectos adversos. Es mucha la posibilidad de encontrar EI refractaria al tratamiento farmacológico y se ha concluido que deben evaluarse las alternativas de tratamiento no farmacológico mediante estudios clínicos sistemáticos. El diagnóstico temprano, la instauración de un tratamiento farmacológico, la educación de los propietarios de animales y la combinación con terapias no farmacológicas representan a la fecha la única forma de mejorar el pronóstico de perros afectados con EI.

Transplantation of olfactory ensheathing cells fails to promote significant axonal regeneration from dorsal roots into the rat cervical cord.

The olfactory ensheathing cell (OEC) is a class of glial cell that has been reported to support regeneration in the central nervous system after various types of lesions, including rhizotomy of spinal dorsal roots at thoracic, lumbar and sacral levels. We have therefore carried out a detailed anatomical analysis to assess the efficacy of dorsal horn OEC transplants at promoting regeneration of primary afferents across the dorsal root entry zone (DREZ) at the cervical level in the adult rat. OECs were cultured from adult rat olfactory bulb and immunopurified (90% purity). Regeneration by large diameter afferents and by both peptidergic and non-peptidergic small diameter afferents was assessed using respectively cholera toxin B (CTB) labelling and immunocytochemistry for calcitonin gene-related peptide (CGRP) and the purinoceptor P2X3. Following an extensive (C3-T3) rhizotomy, CGRP and P2X3 immunoreactive axons regenerated across the rhizotomy site as far as the DREZ but there was no evidence of regeneration across the DREZ, except through sites where the OEC transplant was directly grafted into the DREZ. No evidence of regeneration into the dorsal horn by CTB-labelled axons was obtained. In addition, there was little sign of sprouting by intact axons in the vicinity of OEC transplant sites. In contrast to these results in vivo, cocultures of OECs and adult dorsal root ganglion cells showed that OECs stimulate extensive neurite outgrowth. The failure of the OECs to promote regeneration in vivo following cervical rhizotomy is therefore most likely due to factors in the environment of the graft site and/or the method of transplantation.