NGF Group Research Articles

Efficacy of Biological and Physical Enhancement on Targeted Muscle Reinnervation

Targeted muscle reinnervation (TMR) is a microsurgical repair technique to reconstruct the anatomical structure between the distal nerve and the muscle stump to provide more myoelectric information to the artificially intelligent prosthesis. Postoperative functional electrical stimulation treatment of the patient's denervated muscle or proximal nerve stump as well as nerve growth factor injection is effective in promoting nerve regeneration and muscle function recovery. In this experiment, we successfully established a TMR rat model and divided Sprague-Dawley (SD) adult male rats into TMR group, TMR + FES group, and TMR + NGF group according to TMR and whether they received FES treatment or NGF injection after surgery, and the recovery effect of rat neuromuscular function was assessed by analyzing EMG signals. Through the experiments, we confirmed that growth factor supplementation and low-frequency electrical stimulation can effectively promote the regeneration of the transplanted nerve as well as significantly enhance the motor function of the target muscle and have a positive effect on the regeneration of the transplanted nerve.

Value of Plasmatic Villin-1 in the prediction of early graft dysfunction in kidney transplant recipients among Egyptian population

Abstract Background One of the main complications of kidney transplantation is delayed graft function (DGF). There has been enormous growing research interest in the potential for the rapidly expanding fields of medical technology to generate new biomarkers with the aim of early prediction of DGF and modifying its therapy accordingly. Villin-1 has been detected in urine of patients with AKI. Additionally, it is redistributed during AKI from the brush borders of the proximal tubular cells toward the basolateral membrane which positions villin-1 closer to the renal vasculature and suggests that it could be released in the blood as well, so can be as a novel biomarker for DGF. Methods Of 70 patients with end-stage renal disease with one or more risk factor for developing delayed graft function attending renal transplantation preparation clinics in ASUSH, IMC and NILE Badrawi hospital in Egypt from May 2016 to July 2019, 41 patients were eligible and assigned into two groups according to the correlation with the serum creatinine levels in the first two days post-transplantation after signed informed consent for participation in our study into group 1 (DGF group) and group 2 (NGF group). We measured the presence of villin-1 by ELISA technique (quantitative) in comparison to serum creatinine levels in plasma at the time of declamping (zero level), 1st, 3rd, 5th, 7th, 12th, 24th, 48th, 72th 96th, 120th hour post declamping, also samples from normal population and chronic kidney disease stage V patients have been collected to establish reference range guide for plasmatic villin-1 in both groups. Results Statistically significant differences were noted in the comparison between both groups as regard the plasmatic villin-1 levels at the same measurement points in both groups, also plasmatic villin-1 started to rise above its reference range in the ESRD patients at the 5th hour post declamping while its peak was at the 7th hour in the DGF group’s recipients then started to decrease after that but didn’t settle down between the reference range guide during the regular follow up of its level till the 120th hour post declamping. the reference range guide was from 0.08 and 0.35 ng\ml in males and from 0.055 to 0.35 ng\ml in females in normal population while from 0.38 and 1.4 ng\ml in males and from 0.28 to 1.1 ng\ml in females in the ESRD patients. Conclusions Plasmatic villin-1 is a promising novel biomarker for detection of early graft dysfunction in kidney transplant. Due to restrictions of the study design these observations need further confirmation by prospective studies.

Evidence for the LH-releasing pathway of seminal plasma NGF in male camelids

In the female camelid, systemic administration of NGF induces a preovulatory LH surge that results in ovulation, but the effects of seminal NGF in the male are unknown. In the present study, we tested the hypothesis that the LH-releasing pathway of NGF is present in male camelids. In Experiment 1, male llamas and alpacas were treated with NGF or GnRH (n = 2 llamas and 3 alpacas) and blood samples were collected from 1 h before to 3 h after treatment. Plasma LH concentrations increased after treatment in a surge-like fashion in both GnRH- and NGF-treated groups, but concentrations reached a maximum 2.5 times higher and remained elevated for at least 2 h longer in the NGF-treated group (treatment-by-time interaction, P = 0.01). In Experiment 2, we evaluated the LH and testosterone response to NGF vs saline treatment (n = 3 llamas and 3 alpacas). The LH response to NGF was similar to that in Experiment 1, and plasma testosterone concentrations were higher in the NGF group than in the saline group at 2, 4 and 6 h after treatment (P < 0.05). Results support the hypothesis that the LH-releasing pathway for NGF exists in male South American camelids. The LH response to NGF sustained circulating testosterone concentrations in llamas, suggesting a moderate role of NGF in testosterone secretion.

Relationship between neuropilin-1 expression and prognosis, according to gastric cancer histology.

Neuropilin-1 (NRP-1) is known to be related to various types of cancer and is considered a novel tumor marker or therapeutic target. The aim of this study was to identify the clinical implications of NRP-1 expression in terms of prognosis in patients with gastric cancer. A total of 265 patients who underwent radical gastrectomy for the treatment of gastric cancer from 2008 to 2011 were included in this retrospective study. NRP-1 expression of tumors was determined by immunohistochemistry. The patients' clinicopathological characteristics, operative details, and long-term outcomes were retrospectively analyzed. A total of 181 (68.3%) patients demonstrated expression of NRP-1. No survival difference was observed according to NRP-1 expression in any patient. The patients were divided into the gland formation (GF) and the no gland formation (nGF) types, according to histology. NRP-1 expression rates were 65.6% (84/128) and 70.8% (97/137), respectively. NRP-1 expression was not an independent prognostic factor in the GF group, although patients who expressed NRP-1 had better survival outcomes. In contrast, patients who expressed NRP-1 in the nGF group had worse 5-year survival rates (p = 0.027), and NRP-1 was an independent prognostic factor in a multivariate analysis (hazard ratio, 1.923; 95% confidence interval, 1.041-3.551). NRP-1 expression in patients with nGF type gastric cancer is predictive of a poor prognosis.

Effects of endogenous inflammation signals elicited by nerve growth factor, interferon-\u03b3, and interleukin-4 on peripheral nerve regeneration

BackgroundLarge gap healing is a difficult issue in the recovery of peripheral nerve injury. The present study provides in vivo trials of silicone rubber chambers filled with collagen containing IFN-γ or IL-4 to bridge a 15 mm sciatic nerve defect in rats. Fillings of NGF and normal saline were used as the positive and negative controls. Neuronal electrophysiology, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide and histology of the regenerated nerves were evaluated.ResultsAt the end of 6 weeks, animals from the groups of NGF and IL-4 had dramatic higher rates of successful regeneration (100 and 80%) across the wide gap as compared to the groups of IFN-γ and saline controls (30 and 40%). In addition, the NGF group had significantly higher NCV and shorter latency compared to IFN-γ group (P < 0.05). The IL-4 group recruited significantly more macrophages in the nerves as compared to the saline controls and the NGF-treated animals (P < 0.05).ConclusionsThe current study demonstrated that NGF and IL-4 show potential growth-promoting capability for peripheral nerve regeneration. These fillings in the bridging conduits may modulate local inflammatory conditions affecting recovery of the nerves.

Fabrication of extracellular matrix-coated conductive polypyrrole-poly(l-lactide) fiber-films and their synergistic effect with (nerve growth factor)/(epidermal growth factor) on neurites growth

Non-nerve cell-derived extracellular matrix (ECM) was coated on the aligned porous polypyrrole-poly(l-lactide) (PPy-PLLA) fiber-films with the conductivity of ∼12 mS/m via L929 cells culture and lysing, resulting in ∼10% increase of PC12 cells attachment and ∼26 μm increase of neurites length. The neurite length of ∼149 μm in EGF/NGF group (optimal concentration radio of 12.5/50 (ng/mL)) on aligned and ECM-conjugated fiber-films was significantly larger than ∼94 μm in only NGF group (50 ng/mL), confirming the synergy of EGF, NGF and aligned ECM-conjuaged PPy-PLLA fibers. When differentiated PC12 cells were exerted electrical stimulation (ES) of 100 mV/cm for 4 h/day in 2 day through ECM-PPy-PLLA fiber-films, their neurite length reached to ∼251 μm, significantly larger than ∼149 μm of group without ES, due to the higer expression of related neural proteins in ES group. A simple mechanism was proposed to analyze synergistical effect of ECM, EGF, NGF on axons adhesion and elongation along the aligned ECM-coated fibers under ES condition.

Evaluation of the effect of mating, intrauterine deposition of raw seminal plasma or seminal plasma purified β-NGF on endometrial vascularization in llamas

The aim of this study was to evaluate the endometrial vascularization area (EVA) of both uterine horns in llamas subjected to different intrauterine treatments resembling physiological conditions after a single mating. Llamas with a growing follicle (≥8 mm) were randomly assigned to: a) single mating with a fertile male (mating; positive control; n = 6); b) intramuscular administration of 50 μg of gonadorelin acetate plus an intrauterine infusion of 4 ml of PBS (GnRH; negative control; n = 4); c) intrauterine infusion of 4 ml of raw llama seminal plasma (SP; n = 4) or d) intrauterine infusion of 10 mg of β-NGF purified from llama semen diluted in 4 ml of PBS (spβ-NGF; n = 6). Females in GnRH, SP and NGF group received 50% of treatment volume into each horn by guiding an insemination pipet through the cervix. Ovaries were examined by ultrasonography every 12 h until Day2 (Day 0 = Day of treatment) to determine ovulation. Power-Doppler ultrasonography evaluation of EVA in a cross-section of the middle segment of each horn was conducted at 1 h before and 1, 3, 6, 12 and 24 h (intensive evaluation) and 2, 4, 6 and 8 days (long-term evaluation) after treatment administration. Serial EVA data was analyzed as a 2-by-2 factorial design for repeated measures using the MIXED procedure. The analysis included main effects of treatment (mating, SP, spβ-NGF or GnRH), uterine horn (left vs right), time, and their interactions. According to the 2 by 2 analysis there was no effect of uterine horn on EVA during the first 24 h and from Day 2 to Day 8 after treatment; therefore, data were grouped based on treatment type regardless of uterine horn for both periods of observation. Thus, EVA was affected by time (P < 0.04) and treatment by time interaction (P < 0.02) and tended (P = 0.07) to be influenced by type of treatment during the intensive evaluation period. Females on mating and spβ-NGF group showed a significant increase in EVA at 3 and 12 h after treatment compared to GnRH and SP groups. However, no effect of treatment, time or their interaction was observed during the long-term evaluation period. In spite of the limited number of animals used in this study, our results allow us to concluded that natural mating and intrauterine deposition of 10 mg of spβ-NGF induce a symmetrical increase in endometrial vascularization of both uterine horns during the first 24 h post treatment administration in llamas; however, this effect did not persist beyond that period.

Facilitation of facial nerve regeneration using chitosan-β-glycerophosphate-nerve growth factor hydrogel

Conclusion C/GP hydrogel was demonstrated to be an ideal drug delivery vehicle and scaffold in the vein conduit. Combined use autologous vein and NGF continuously delivered by C/GP-NGF hydrogel can improve the recovery of facial nerve defects. Objective This study investigated the effects of chitosan-β-glycerophosphate-nerve growth factor (C/GP-NGF) hydrogel combined with autologous vein conduit on the recovery of damaged facial nerve in a rat model. Methods A 5 mm gap in the buccal branch of a rat facial nerve was reconstructed with an autologous vein. Next, C/GP-NGF hydrogel was injected into the vein conduit. In negative control groups, NGF solution or phosphate-buffered saline (PBS) was injected into the vein conduits, respectively. Autologous implantation was used as a positive control group. Vibrissae movement, electrophysiological assessment, and morphological analysis of regenerated nerves were performed to assess nerve regeneration. Results NGF continuously released from C/GP-NGF hydrogel in vitro. The recovery rate of vibrissae movement and the compound muscle action potentials of regenerated facial nerve in the C/GP-NGF group were similar to those in the Auto group, and significantly better than those in the NGF group. Furthermore, larger regenerated axons and thicker myelin sheaths were obtained in the C/GP-NGF group than those in the NGF group.

Prolonged Stimulation-Induced Pro-Apoptotic B Cells and Deficits in the Germinal Center Formation of Memory B Cells within One Year after Allogeneic HSCT

s / Biol Blood Marrow Transplant 21 (2015) S147eS170 S167 overall survival (OS) was 54% (95% CI, 41e66%) for the entire cohort with an OS for NNGF of 73% (95% CI, 55 e 85%) and for NGF OS was 30% (95% CI, 14e47%) (p<0.01). A second GF occurred in 18 (67%) NGF and in 9 (26%) NNGF patients. Viral studies showed there was more frequent HHV6 reactivation, with 48% of the NGF group versus 8.8% of the NNGF group (p< 0.01) having reactivation. EBV and CMV reactivate was not different. The most common cause of death after second HCT was persisting GF leading to infection or infection despite engraftment. Outcomes of second HCT for NGF and NNGF are different with very poor outcomes for the NGF group, necessitating new approaches to improve overall survival.

Experimental Study on Mechanical Vibration Massage for Treatment of Brachial Plexus Injury in Rats

To investigate the curative effect of the self-made mechanical vibration massage instrument for treatment of brachial plexus injury in rats and to explore its mechanism. Brachial plexus injury models were made in 144 Wistar rats and one week after natural healing of the wound, they were randomly divided into 3 groups, mechanical vibration treatment group (MV group), nerve growth factor treatment group (NGF group) and model group, 48 rats in each group. Then again, the each group was randomly divided into 4 subgroups, 7-day group, 14-day group, 21-day group and 28-day group, 12 rats in each subgroup. The MV group were treated by mechanical vibration at acupoints on three-yang and three-yin channels of the hand with the mechanical vibration massage instrument; The NGF group were treated with injection of NGF into musculus pectoralis major on the affected side; And the model group were normally fed with no treatment. After treatment for 7, 14, 21 and 28 days, the diameter of both forelimbs were measured, the electrophysiological examination on the brachial plexus in vitro and the ultrastructure observation with electron microscope on the affected side were carried out, the motor nerve conduction velocity (MNCV) and motor nerve action potential (MNAP) of the brachial plexus on the affected side, NGF content of submaxillary gland as well as muscular Na+, K(+)-ATPase activity were determined respectively. The different rates of the forelimb diameter in the MV group and the NGV group on the 14th d, 21st d and 28th d were better than those in the model group (P < 0.05 or P < 0.001), and in the MV group were better than those in the NGF group on the 21st d and the 28th d (P < 0.05). MNCV in the MV group and the NGV group on the 21st d and 28th d was better than that in the model group (P < 0.05 or P < 0.001), and in the MV group was better than that in the NGF group on the 28th d (P < 0.05). MNAP in the MV group and the NGV group on the 14th d, 21st d and 28th d was better than that in the model group (P < 0.05 or P < 0.001), and in the MV group was better than that in the NGF group on the 21st d and 28th d (P < 0.05). The NGF mean gray index of submaxillary gland in the model group was higher than that in the MV group and the NGF group on the 7th d (P < 0.05); in the NGF group and the model group was higher than that in the MV group on the 14th d (P < 0.05); and in the NGF group and the MV group was higher than that in the model group on the 21st d and 28th d (P < 0.05). Na+, K(+)-ATPase activity in the model group and the MV group was higher than that in the NGF group (P < 0.05) on the 14th d, and in the MV group was higher than that in the model group on the 28th d (P < 0.05). As compared with the NGF group and the model group, mechanical vibration treatment can effectively accelerate repair of injured brachial plexus, slow down atrophy of skeletal muscle, and promote secretion of NGF in submaxillary gland.

Experimental study of erythropoietin on promoting sciatic nerve regeneration in rats

Objective To explore the effect of erythropoietin (EPO) on nerve regeneration after sciatic nerve injury and repair in rats and provide experimental basis for clinical treatment of peripheral nerve injury.Methods Forty male Sprague-Dawley rats were randomly divided into two groups, which were named EPO group and NGF group respectively . The sciatic nerve with 10 mm defect was bridged with silicone conduit. Rats of EPO group and NGF group received injection of erythropoietin and nerve growth factor respectively. At 4 and 8 weeks postoperatively, 10 rats from each group were subject to sciatic functional index (SFI), motor nerve conduction velocity (MNCV) and histomorphometric evaluation and immunohistochemical staining of protein gene product 9. 5 (PGP 9. 5) to assess the effect of erythropoietin on rat sciatic nerve regeneration. Results Four weeks after the operation , SFI was - 78.85 + 3.87 in EPO group and - 79.98 ± 4.58 in NGF group. There was no significant difference between the two groups( P > 0.05). Eight weeks postoperatively , SFI was - 60.26±2.91 in EPO group and -64.65 ± 4.11 in NGF group, with significant difference between the two groups( P <0.05). Four and eight weeks after the operation, MNCV, the number of myelinated nerve fibers, the mean optical density and the integration optical, density of PGP 9.5-immtive nerve fibers were significantly higher in EPO group than in NGF group (P < O. 05). Conclusion Erythropoietin can improve nerve regeneration after sciatic nerve injury and repair in rats. Key words: Sciatic nerve; Injuries; Nerve regeneration; Etythropoietin

Effects of neurotrophic factors on nerve regeneration monitored by in vivo imaging in thy1-YFP transgenic mice

We evaluated sciatic nerve regeneration in thy1-YFP transgenic mice selectively expressing a fluorescent protein in their axons. Using in vivo imaging, we observed the dorsal cutaneous renervation of the hind paw for 8 weeks. Three to four weeks after the operation, the length of the regenerated nerve treated with NGF tended to be longer than that of the regenerated nerve treated with saline. Functional recovery was evaluated by a withdrawal response of the hind paw to mechanical stimuli. In NGF and GDNF groups, mice started to resume a mechanical response 4 weeks after the operation, earlier than in the saline control group. Histological and ultrastructural analyses showed that the density of unmyelinated axons in the regenerated nerve of the NGF group was larger than that of those in the saline group. These results indicate that NGF accelerated the regeneration of the sciatic nerve and thus that the monitoring of cutaneous nerve regeneration in the dorsal foot is useful to evaluate the regeneration of the sciatic nerve in vivo.

The effect of nerve growth factor on the development of human primordial follicles in vitro culture

OBJECTIVE: To investigate the actions of NGF on human early follicle development. DESIGN: Case-controlled experiment. MATERIALS AND METHODS: Ovarian biopsies from 21 patients were cut into ovarian pieces(opt) of lmm thickness which distributed into 5 groups: groupI (non-culture group),groupII (NGF group),groupIII (basic culture group),groupIV (anti-NGF antibody group),groupV (control IgG group). After culture, all the tissue samples were fixed for histological analysis, immunohistochemistry analysis,TUNEL test. RESULTS: Here were 33.83%±31.73%, 53.51%±39.41%, 39.30±31.73% primordial follicles among groupII, groupIII and groupIV,significantly lower than the proportion of primordial of groupI,which was 82.16%±13.63%, P<0.01; the percentage of developing follicles in groupII was 54.14%±26.16%, significantly higher than that of groupI, groupIII and groupIV, which were 14.63%±15.00%, 23.39%±28.66%, 31.44±32.24% respectively, P<0.01. The percentage of abnormal follicles in groupI was 3.22%±7.48%, significantly lower than that of groupIII, groupII, groupIV, which were 23.1%±30.94%, 12.03%±11.75%, 29.26±28.61% respectively, P<0.05. The Positive Unit value of groupI, groupIII, groupII, groupIV were 6.63 ±3.77, 5.66 ± 4.74, 12.48 ± 6.61, 6.67±4.58, 6.92±6.66 respectively, the PU value of groupII was significantly higher than that of the other groups, p<0.05. The PCNA positive follicles in groupI, groupIII, groupII, groupIV, groupV were 28.45%, 37.25%, 59.79%, 22.72%, 33.33% respectively, the rate of positive follicles in groupII was higher than that of groupIII and groupIV, p<0.005. The apoptotic index of stroma cells of groupII, groupIII, groupIV, groupV were 0.06±0.06, 0.12±0.07, 0.14±0.09, 0.12±0.09 repectively. The apoptotic index of stroma cell in groupII was significantly lower than that of groupIII, groupIV, p<0.01. CONCLUSIONS: NGF can help to promote the transition of primordial-to-primary follicles and their development in vitro culture of human ovarian tissues; By decreasing the apoptosis and increasing proliferation of stroma cells, NGF can help to promote the survival and development of early follicles in vitro culture of human ovarian tissues.

Gelatin–tricalcium phosphate membranes immobilized with NGF, BDNF, or IGF‐1 for peripheral nerve repair: An in vitro and in vivo study

In the present study, NGF, BNDF from the neurotrophin family and IGF-1 were covalently immobilized on gelatin-tricalcium phosphate (GTG) membrane using carbodiimide. We investigated the effects of these growth factors released from the GTG composites on cultured PC12 cells and sciatic nerve regeneration across a 10-mm-long gap in rats. In PC12 cell culture, the total protein content and MTT assay indicated more cell attachment on the composites modified with growth factors. The IGF-1 group showed a higher survival promotion effect on PC12 cells than did BDNF and NGF groups. On the other hand, NGF released from the composite showed the highest level of neuritogenesis for PC12 cells in neurite outgrowth assay. In the animal study, the GTG conduits modified with various growth factors were well tolerated by the host tissue. In the regenerated nerves, the number of the axons per unit area of the BDNF group was significantly higher than that of NGF and GTG groups but similar to that of IGF-1 group. However, the average axon size was the largest in NGF group. This result was in concordance with the neurite outgrowth assay in which NGF showed the highest neuritogenic potential. In the assessment of motor and sensory recovery after nerve repair, conduits modified with various neurotrophic factors showed a more favorable outcome in compound muscle action potential. The BDNF group had a better gastrocnemic muscle weight ratio than blank GTG repair. Nevertheless, the different effects of GTG conduits modified with various neurotrophic factors on functional recovery cannot be simply illustrated in the sciatic function index.

GDNF and NGF released by synthetic guidance channels support sciatic nerve regeneration across a long gap.

The present work was performed to determine the ability of neurotrophic factors to allow axonal regeneration across a 15-mm-long gap in the rat sciatic nerve. Synthetic nerve guidance channels slowly releasing NGF and GDNF were fabricated and sutured to the cut ends of the nerve to bridge the gap. After 7 weeks, nerve cables had formed in nine out of ten channels in both the NGF and GDNF groups, while no neuronal cables were present in the control group. The average number of myelinated axons at the midpoint of the regenerated nerves was significantly greater in the presence of GDNF than NGF (4942 +/-1627 vs. 1199 +/-431, P < or = 0.04). A significantly greater number of neuronal cells in the GDNF group, when compared to the NGF group, retrogradely transported FluoroGold injected distal to the injury site before explantation. The total number of labelled motoneurons observed in the ventral horn of the spinal cord was 98.1 +/-23.4 vs. 20.0 +/-8.5 (P < or = 0.001) in the presence of GDNF and NGF, respectively. In the dorsal root ganglia, 22.7% +/- 4.9% vs. 3.2% +/-1.9% (P +/-0.005) of sensory neurons were labelled retrogradely in the GDNF and NGF treatment groups, respectively. The present study demonstrates that, sustained delivery of GDNF and NGF to the injury site, by synthetic nerve guidance channels, allows regeneration of both sensory and motor axons over long gaps; GDNF leads to better overall regeneration in the sciatic nerve.

Evaluation of peripheral nerve regeneration by nerve growth factor locally administered with a novel system.

An experimental model is presented for the local administration of neurotrophic substances at the site of peripheral nerve lesion. The model consists of a subcutaneously implanted silicone reservoir and a connecting tube with its distal end facing the severed and repaired nerve. Wistar rats (n = 180) were divided into two groups: a control group (saline-treated) (n = 90) and an NGF-treated group (n = 90). After sciatic nerve axotomy, an epineural repair was performed. NGF or saline were injected daily into the subcutaneous reservoir for the first 4 weeks after axotomy and weekly single dose between the 8th and 12th weeks. Both groups were divided into three subgroups of 30 animals each. The animals were sacrificed at 4, 8 and 12 weeks. Myelinated and non-myelinated axonal and thickness of myelin sheaths were quantified at the tibialis branch 25 mm distal to the nerve repair site. Axonal counts showed statistically significant differences between the treated and control groups at 4, 8 and 12 weeks. Finally, at 4 weeks the myelinated axons in the NGF group had significantly thicker myelin sheaths than in the control group. In comparison with other models of administration of different neurotrophic agents, NGF delivered through this system demonstrates a significant capacity for improving nerve regeneration without the problems inherent in multiple anesthesia, device exchange, or short half-life of the NGF single-dose administration.

Delay in manifestations of aging by grafting NGF cultured cromaffin cells in adulthood

Dopamine agonists or grafts compensate impaired motor functions in aged rats. However, there is no evidence showing whether grafting in adulthood retard aging manifestations. Motor performance of 13- month-old rats was tested on 2 meter-long wooden beams which had a 15° inclination and whose thickness varied from 3, 6, 12, 18, to 24 mm. Rats at 14 months were randomly assigned to 3 groups: sham graft (Group 1); intrastriatal graft of chromaffin cells cultured with NGF (Group 2); intrastriatal graft of chromaffin cells (Group 3). Motor performance was tested at monthly intervals up until rats were 26 months old. Two more groups were included: 26-month-old naive rats (Group 4); and 3- to 5-month-old naive rats (Group 5) both evaluated only once. At 26 months, the basal activity of ventral mesencephalic dopaminergic neurons was recorded. Results showed in Group 2 delay of motor detriments seen in aged rats, maintenance of basal firing rates of nigral cells comparable to those of younger rats, and greater survival of substantia nigra cells. It is suggested that NGF cultured chromaffin cells produce a delay of motor detriments in aged rats, as a result of inducing survival and firing rates of nigral cells comparable to those seen in young rats.

Effect of NGF on the survival of rat retinal ganglion cells following optic nerve section

The ability of NGF (2.5S subunit) to support the survival of adult rat retinal ganglion cells (RGCs) and optic nerve fibers after intracranial section of the optic nerve was investigated. NGF was injected intraocularly at a dose of 3 micrograms/injection every 2.3 d from the day of axotomy to analysis. Control animals received cytochrome c injections. The survival of RGCs was analyzed in whole-mounted retinas after either cresyl violet staining or labeling with HRP applied to the proximal stump of the optic nerve. Survival times were 5 and 7 weeks. Diameter distribution and number of myelinated optic nerve fibers were assessed in ultrathin cross sections of the optic nerve. We found that RGCs surviving axotomy were much more numerous following NGF treatment compared with controls. Large-size cells were, in particular, preserved by NGF treatment. The quantitative ultrastructural studies indicated that the number of myelinated optic nerve fibers at 5 and 7 weeks postaxotomy was significantly greater in the NGF group with respect to the cytochrome c group. In agreement with the results obtained at the level of the RGCs, large-diameter axons were, in particular, preserved. We conclude that NGF injected intraocularly is effective in promoting the survival of RGCs and optic nerve fibers at least for a period as long as 7 weeks after intracranial section of the optic nerve.

Effects of antimitotic drugs on the morphological features of PC 12 cells in culture—a light and EM study

PC12 cells were grown in monolayer cultures either as untreated controls or treated with (1) NGF, (2) mitomycin C/BUdR, or (3) a combination of NGF and mitomycin C/BUdR. The cells from these four groups were processed for scanning and transmission electron microscopy and for fluorescence histochemistry. With scanning electron microscopy, the control and mitomycin C/BUdR treated cells showed the presence of very small extensions for attachment, and numerous fine processes on the cell surface, while the NGF treated cells and cells treated with the combination exhibited many large processes that were even longer with the combination treatment. The combination treatment also inhibited cell growth completely. Fluorescence histochemical studies revealed strong fluorescence in the perikarya of cells from all the four groups. Transmission electron microscopic studies showed that the cells in all the four groups contained many chromaffin-type granules in addition to the presence of other cellular organelles. The neurites in the NGF group and the combination treatment also contained these granules and well-defined microtubules. Therefore, antimitotic agents inhibit PC12 cell growth without affecting important cellular parameters.