Biomedical subjects

M Tadie

Publications and source records attributed to M Tadie.

At least 19 recordsLinked to original sources

PubMed2006

Multimodal cerebral monitoring and decompressive surgery for the treatment of severe bacterial meningitis with increased intracranial pressure.

Bacterial meningitis is still associated with a high mortality, mainly because of cerebral herniation as a result of increased intracranial pressure. Published data stress the necessity of an early diagnosis and immediate start of antibiotic therapy. Nevertheless, there are only few reports in which therapeutic strategy was based on the monitoring and the reduction of intracranial pressure (ICP). We report one case of bacterial meningitis caused by Neisseria meningitidis with an initial ICP value of 60 mmHg, which was treated by large hemicraniectomy and ventriculostomy, leading to a favorable neurological long-term result. The surgical decision was accelerated by an accurate ICP evaluation based on cerebral monitoring [transcranial Doppler ultrasonography (TCD) and intracranial ICP-device]. In selected patients with bacterial meningitis and clinical and radiological evidence of elevated ICP, cerebral monitoring and aggressive reduction of ICP may be crucial to improve survival and neurological outcome. When maximal medical ICP treatment fails to reduce severe intracranial hypertension, decompressive craniectomy should be rapidly proposed.

Adult↗

PubMed2004

Angio-architecture of spinal cord arteriovenous shunts at presentation. Clinical correlations in adults and children. The Bicêtre experience on 155 consecutive patients seen between 1981-1999.

OBJECTIVE: To analyse possible relationships between the symptoms and signs created by intradural spinal cord arteriovenous shunts (SCAVSs) and their angio-architecture. METHODS: The clinical and radiological files of 155 patients, both adults and children, seen between 1981 and 1999 with a SCAVS were retrospectively reviewed. SCAVSs were divided into nidus type (small superficial or large intramedullary), and fistulas (micro (mAVFs)- or macrofistulas (MAVFs)). The angio-architectural points studied were arterial stenosis, proximal arterial aneurysm, distal arterial aneurysm, arteriovenous fistulas, pial venous drainage and/or reflux, venous ectasias, venous stenosis, venous thrombosis, false aneurysms. Correlations between architecture, location, age groups and symptoms and signs were made. FINDINGS: A male predominance was noted in both adults and children. Most of the lesions were located at the thoracic level, but hemorrhage occurred as the presenting event predominantly in cervical localizations. 30 patients (20 AVMs; 4 mAVFs, 6 MAVFs) were children. 5 of the 6 MAVFs found in children were associated with Hereditary Hemorrhagic Telengiectasia (HHT1). Twenty one children (70%) had bled. Spontaneous total or subtotal recovery was the rule in 15 of those who had bled (72%) but early recurrent hemorrhages occurred in 2. Among 125 adults 56 presented with hemorrhage (45%). The proportions of those who recovered spontaneously (71%) or rebled (3,6%) in the same year after the initial episode were very similar to children. All other adults presented with acute or progressive non-hemorrhagic episodes. There was no significant difference in the angio-architecture between hemorrhagic and non hemorrhagic SCAVS, except for that occurrence of pseudo-aneurysms. Hemorrhage in SCAVSs may not be exclusively due to haemodynamic factors. Venous congestion was responsible for progressive symptoms. Acute deficits unrelated to bleeds were due to intralesional thrombosis or hemodynamic changes. INTERPRETATION: The short term prognosis of hemorrhagic SCAVSs is good, and there is no need for emergency treatment. MRI delineates the cord and makes the diagnosis of the lesion but angiography remains the gold standard for analysis of the vasculature. The angio-architecture reflects the ageing of the lesion but there is not a precise correlation between angio-architecture and clinical symptoms, except for pseudoaneurysms which relate to the hemorrhagic portion of the lesion.

Adolescent↗

PubMed2002

Partial return of motor function in paralyzed legs after surgical bypass of the lesion site by nerve autografts three years after spinal cord injury.

Spinal cord injuries often result in irreversible loss of motor and somatosensory functions below the lesion level. Treatment is limited to physiotherapy aimed at compensating disability. We previously showed that re-establishment of tissue continuity can be achieved in animal models through nerve autografts implanted between the rostral spinal ventral horn and the caudal ventral roots. Rostral motor neuron axons could thus reach peripheral targets, leading to some return of motor function. We used a similar approach in a paraplegic patient with stabilized clinical states three years after spinal cord traumatic damage at the T9 level. Three segments from autologous sural nerves were implanted into the right and left antero-lateral quadrant of the cord at T7-8 levels, then connected to homolateral L2-4 lumbar ventral roots, respectively. Eight months after surgery, voluntary contractions of bilateral adductors and of the left quadriceps were observed. Muscular activity was confirmed by motor unit potentials in response to attempted muscle contraction. Motor-evoked potentials from these muscles were recorded by transcranial magnetic stimulation. These data support the hypothesis that muscles have been re-connected to supra-spinal centers through motor neurons located in the rostral stump of the damaged cord. They suggest that delayed surgical reconstruction of motor pathways may contribute to partial functional recovery.

Electromyography↗

PubMed2002

Sensorimotor cortical activity in patients with complete spinal cord injury: a functional magnetic resonance imaging study.

Residual activation of the cortex was investigated in nine patients with complete spinal cord injury between T6 and L1 by functional magnetic resonance imaging (fMRI). Brain activations were recorded under four conditions: (1) a patient attempting to move his toes with flexion-extension, (2) a patient imagining the same movement, (3) passive proprio-somesthesic stimulation of the big toes without visual control, and (4) passive proprio-somesthesic stimulation of the big toes with visual control by the patient. Passive proprio-somesthesic stimulation of the toes generated activation posterior to the central sulcus in the three patients who also showed a somesthesic evoked potential response to somesthesic stimulation. When performed under visual control, activations were observed in two more patients. In all patients, activations were found in the cortical areas involved in motor control (i.e., primary sensorimotor cortex, premotor regions and supplementary motor area [SMA]) during attempts to move or mental imagery of these tasks. It is concluded that even several years after injury with some local cortical reorganization, activation of lower limb cortical networks can be generated either by the attempt to move, the mental evocation of the action, or the visual feedback of a passive proprio-somesthesic stimulation.

Adult↗

PubMed2002

[Nocardia farcinica brain abscess: clinical and specific radiological findings and management. Report of two cases in immunononcompromised patients].

Nocardia spp. cerebral abscesses are rare and usually occur in immunocompromised patients. We report two recent cases of cerebral abscesses due to Nocardia farcinica in immunocompetent patients and review the literature about diagnosis and therapeutic issues. Outcome was good for the two patients following an early identification of the bacteria. Stereotactic biopsy was performed in one case and craniotomy with excision of the abscess in the other case. In both cases, complete identification of the bacteria could be achieved, followed by prolonged antibiotic therapy. Exposure to the germ (mainly telluric) is often difficult to suspect from the past medical history of the patient. Diagnosis is also unexpected. Despite the typically and characteristic aspect on CT and MRI, specific identification and anti-microbial sensitivity profiles are necessary to optimize treatment. In some rare cases, unusual species like Nocardia farcinica, can be resistant to numerous antibiotics requiring adjustments of medical management. Early identification of the bacteria is necessary to achieve good outcome in immunocompetents patients.

Adult↗

PubMed2001

Horseradish peroxidase retrograde labeling of primary sensory neurons: a comparison of four intraspinal application methods.

The purpose of this study was to optimize the methods of retrograde labeling of sensory neurons in demonstrating the continuity of post-ganglionic primary sensory axons. This was accomplished by comparing four different methods of horseradish peroxidase (HRP) application into the lower thoracic spinal cord of adult rats (level T11). HRP application with a piece of Gelfoam via a dorsal myelotomy (group 1, n = 8), stereotactic injections with a 0.72-mm tip diameter needle (group 2, n = 8), with a 0.24-mm tip needle (group 3, n = 8), and with a 0.08-mm tip glass micropipette (group 4, n = 5). Histological examination of the application site showed that the extent of spinal cord injury was directly proportional to the diameter of the needle tip. The mean number of dorsal root ganglia (DRG) sensory neurons retrogradely stained by HRP differed among the four experimental groups: 77 +/- 45 (SEM) per DRG in group 1, 106 +/- 24 in group 2, 652 +/- 90 in group 3, and 238 +/- 60 in group 4. A significant difference was found between group 3 and the other ones (P < 0.05). Intraspinal injection of HRP with a fine needle (0.24-mm tip diameter) using a stereotactic approach can achieve effective and reliable retrograde labeling of primary sensory neurons. This reproducible method may be useful in studies dealing with regeneration of post-ganglionic primary sensory axons.

Analysis of Variance↗

PubMed2001

Regrowth of the rostral spinal axons into the caudal ventral roots through a collagen tube implanted into hemisected adult rat spinal cord.

OBJECTIVE: A collagen tube was used to guide axonal regrowth from the spinal cord to the periphery to contribute to improvement of paralysis after lower thoracic spinal cord injury. METHODS: The spinal cords of adult male Sprague-Dawley rats were lesioned by removing the left hemicord from T12 to 5 mm below this level and additionally sectioning all left lumbar ventral roots. In experimental animals (n = 9), a collagen tube was inserted into this gap, spanning the rostral hemisected cord to the caudal sectioned lumbar ventral roots (gap, 7 mm). In control animals (n = 6), no treatment was performed. RESULTS: Six months after surgery, the return of some tension and resistance of the paralyzed hindlimb muscles was observed in all experimental rats except the untreated controls. Nine months postoperatively, muscle action potentials were recorded from the target muscles of the experimental animals while electrostimulating the tissue continuity within the collagen tube. Horseradish peroxidase retrograde labeling showed that the neurons in the rostral cord near the implantation site regrew into the reconnected lumbar ventral roots. Histological examination indicated numerous myelinated axons in the reconnected root pathways and newly formed endplates in the target muscles. No axonal regeneration was found in the control rats. CONCLUSION: These results indicate that the rostral spinal axons can regrow into the caudal sectioned and reconnected ventral roots through a collagen tube, thus innervating the denervated peripheral targets in adult rats after spinal cord injury. This surgical repair model also provides a means for testing the use of trophic factors that may further promote axonal regeneration.

Animals↗

PubMed2001

Use of a collagen-based sealant to prevent in vivo epidural adhesions in an adult rat laminectomy model.

OBJECT: The authors investigated the effect of a collagen-based sealant, Gel Amidon Oxydé (GAO), in the prevention of epidural scar adhesions in an adult rat model of laminectomy. METHODS: Seventy-two adult Sprague-Dawley rats underwent an L5-6 laminectomy, after which the dura mater and the left L-4 and L-5 nerve roots were exposed. In the 36 animals that received GAO, the sealant was applied over the dura and around the nerve roots, and it was used to fill the laminectomy cavity before it polymerized. In 36 control animals, the same surgical treatment was performed, but the rats did not receive GAO. During the early postoperative period, a significant decrease in the occurrence of epidural hematoma was found in the GAO-treated rats. In contrast to findings in control rats, a thin white connective tissue layer was found between the dura and surrounding muscles after GAO had degraded and been absorbed. One month posttreatment, no epidural scar adhesion was found between the tissue layer and the dura in the GAO-treated animals. Three months postoperatively, both gross inspection and histological examination further confirmed that formation of epidural adhesions was significantly inhibited in the rats treated with GAO. No special inflammatory reaction was observed, and the healing of skin and muscle lesions was not affected by either treatment. CONCLUSIONS: The data obtained in this study suggest that the GAO collagen-based sealant may be an effective biomaterial to prevent epidural adhesions in vivo after laminectomy.

Animals↗

PubMed2001

Innervation of the caudal denervated ventral roots and their target muscles by the rostral spinal motoneurons after implanting a nerve autograft in spinal cord-injured adult marmosets.

OBJECT: The authors conducted a study to determine the effects of using a nerve autograft (NAG) to promote and guide axonal regrowth from the rostral spinal cord to the caudal lumbar ventral nerve roots to restore hindlimb motor function in adult marmosets after lower thoracic cord injury. METHODS: Nine animals underwent a left-sided hemisection of the spinal cord at T-12 via left-sided T9-L3 hemilaminectomy, with section of all ipsilateral lumbrosacral ventral nerve roots. In the experimental group (five animals), an NAG obtained from the right peroneal nerve was anastomosed with the sectioned and electrophysiologically selected lumbar ventral roots (left L-3 and L-4) controlling the left quadriceps muscle and then implanted into the left ventrolateral T-10 cord. In the control group (four animals), the sectioned/selected lumbar ventral roots were only ligated. After surgery, all marmosets immediately suffered from complete paralysis of their left hindlimb. Five months later, some clinical signs of reinnervation such as tension and resistance began to appear in the paralyzed quadriceps of all experimental animals that received autografts. Nine months postoperatively, three of the five experimental marmosets could maintain their lesioned hindlimb in hip flexion. Muscle action potentials and motor evoked potentials were recorded from the target quadriceps in all experimental marmosets, but these potentials were absent in the control animals. Horseradish peroxidase retrograde labeling from the distal sectioned/reconnected lumbar ventral roots traced 234+/-178 labeled neurons in the ipsilateral T8-10 ventral horn, mainly close to the NAG tip. Histological analysis showed numerous regenerating axons in this denervated/reconnected nerve root pathway, as well as newly formed motor endplates in the denervated/reinnervated quadriceps. No axonal regeneration was detected in the control animals. CONCLUSIONS: These data indicate that the rostral spinal neurons can regrow into the caudal ventral roots through an NAG, thereby innervating the target muscle in adult marmosets after spinal cord injury.

Animals↗

PubMed2000

Functional MR imaging and traumatic paraplegia: preliminary report.

PURPOSE: To evaluate residual activity in the sensorimotor cortex of the lower limbs in paraplegia. METHODS: 5 patients suffering from a complete paralysis after traumatic medullar lesion (ASIA=A). Clinical evaluation of motility and sensitivity. 1. Control functional MR study of the sensorimotor cortex during simultaneous movements of hands, imaginary motor task and passive hands stimulation. 2. Concerning the lower limbs, 3 fMRI conditions: 1-patient attempts to move his toes with flexion-extension, 2-mental imagery task of the same movement, 3-peripheral passive proprio-somesthesic stimulation (squeezing) of the big toes. RESULTS: Activations were observed in the primary sensorimotor cortex (M1), premotor regions and in the supplementary motor area (SMA) during movement and mental imaginary tasks in the control study and during attempt to move and mental imaginary tasks in the study concerning the lower limbs. Passive somesthesic stimulation generated activation posterior to the central sulcus for 2 patients. CONCLUSION: Activations in the sensorimotor cortex of the lower limbs can be generated either by attempting to move or mental evocation. In spite of a clinical evaluation of complete paraplegia, fMRI can show a persistence of sensitive anatomic conduction, confirmed by Somesthesic Evoked Potentials.

Adult↗

PubMed1999

Reinnervation of denervated lumbar ventral roots and their target muscle by thoracic spinal motoneurons via an implanted nerve autograft in adult rats after spinal cord injury.

Intraspinally implanting a nerve autograft (NAG) to promote axonal regeneration toward periphery was investigated as a surgical treatment for spinal cord injury in adult rats. Fifteen animals underwent a left hemisection of the spinal cord at T12 level and an intradural section of all ipsilateral lumbar ventral roots. In repaired animals (n = 9), the electrophysiologically selected left L3 and L4 lumbar ventral roots supplying the quadriceps muscle were anastomosed to a NAG. The NAG was taken from the right peroneal nerve and then ventrolaterally implanted into the cord at a level 7 mm rostral to the hemisection. In the control group (n = 6), sectioned lumbar ventral roots were left unrepaired. Nine months later, the animals were assessed with clinical, electrophysiological, and histological examinations. Muscle action potential and motor evoked potential were obtained from the denervated/reinnervated quadriceps in all repaired animals, with a mean amplitude of 918.3+/-328.9 microV and 215.8+/-39.7 microV, respectively. Horseradish peroxidase retrograde labeling from the denervated/repaired lumbar ventral roots, performed in five repaired animals, showed that the mean of labeled neurons, ipsilaterally located in the thoracic ventral horn near the implantation site, was 145.8+/-111.7. Histological analysis showed numerous myelinated axons in the NAG and denervated/repaired lumbar ventral roots of all repaired animals. The study of neuromuscular junctions furthermore confirmed numerous newly formed endplates appearing in the denervated/reinnervated quadriceps. These changes were absent in the control animals. These data indicate that the rostral thoracic spinal motoneurons can innervate the caudal denervated/repaired lumbar ventral roots and the target quadriceps via an implanted NAG, thereby inducing some functional recovery in adult rats after lower thoracic spinal cord injury.

Action Potentials↗

PubMed1998

Increase in the chronically monitored cerebrospinal fluid pressure after experimental brain injury in rats.

The early effects of experimental brain injury with diffuse axonal lesions on intracranial pressure (i.c.p.), mean arterial pressure (MAP) and cerebral perfusion pressure (CPP) in rats have been already studied. The aim of this experiment was to examine the effects of brain injury on ICP, MAP and CPP during the first few days post-injury. In order to do that, an accurate technique of ICP measurement had to be developed. In a series of eight rats, a translumbar intrathecal catheter (TIC) was surgically introduced allowing repeated measurements of cerebrospinal fluid pressure (CSFP). Under anaesthesia, a second series of nine rats were equipped simultaneously with TIC and an intracranial fiberoptic device to measure ICP. Simultaneous measurements of CSFP and ICP were recorded for baseline values, than during and after jugular compression which was intended to induce an acute and significant increase in ICP. A third series of 53 rats having TIC received an experimental severe brain injury. MAP was measured non-invasively and CPP was calculated as CPP-MAP. CSFP, MAP and CPP were intermittently measured during 5-6 post-traumatic days and compared to the values obtained during ten control rats (SHAM). A clinical score was used to compare clinical condition. The results showed that the translumbar CSFP accurately measured ICP in rats having normal or acutely increased ICP. The experimental brain injury induced increased CSFP lasting up to 5-6 days, with increased MAP during the first 6 hours. CPP values were compromised at 24-48 hours. The clinical performance was reduced in the brain-injured rats. The translumbar technique of CSFP measurement reflected exact ICP in normal and acutely increased ICP in rats. Experimental brain injury with diffuse axonal lesions can increase lumbar CSFP in rats for many days.

Analysis of Variance↗

PubMed1997

Axonal regrowth through collagen tubes bridging the spinal cord to nerve roots.

The capacity of central nervous system (CNS) axons to elongate from the spinal cord to the periphery throughout a tubular implant joining the ventral horn of the spinal cord to an avulsed root was investigated in a model of brachial plexus injury. The C5-C7 roots were avulsed by controlled traction and the C6 root was bridged to the spinal cord over a 3 mm gap by the use of a collagen cylinder containing or not containing an autologous nerve segment, or an autologous nerve graft. Nine months later, the functionality and the quality of the axonal regrowth was evaluated by electrophysiology, retrograde labelling of neurons, and histological examination of the gap area. A normal electromyogram of the biceps was observed in all animals where the C6 root was bridged to the spinal cord. The mean average amplitude of the motor evoked potentials was comprised between 17.51 +/- 12.03 microV in animals repaired with a collagen cylinder, and 27.83 +/- 22.62 microV when a nerve segment was introduced in the tube. In nonrepaired animals spontaneous potentials reflecting a muscle denervation were observed at electromyography. Retrograde labelling indicated that a mean number of 58.88 +/- 37.89 spinal cord neurons have reinnervated the biceps in animals repaired with a tube versus 78.38 +/- 62.11 when a nerve segment was introduced in the channel, and 97.25 +/- 56.23 in nerve grafting experiments. Analyses of the repair site showed the presence of numerous myelinated regenerating axons. In conclusion, our results indicate that spinal cord neurons can regenerate through tubular implants over a 3 mm gap, and that this axonal regrowth appeared as effective as in nerve grafting experiments. The combination of an implant and a nerve segment did not significantly increase the regeneration rate.

Animals↗

PubMed1997

[Motor reconnection between the damaged cervical cord and the denervated biceps muscle using an autologous peripheral nerve segment in the adult marmoset].

Our research group is studying, in the primate (marmoset), the conditions of an anatomical and functional reconstruction of the spinal cord and of its motor connections, following a focal spinal lesion. In this attempt to repair the damaged neuronal circuitry, we used long segments of autologous peripheral nerves joining the injured cervical spinal cord to an aneural region of the denervated biceps brachialis muscle (7 marmosets) or to the musculocutaneous nerve (6 marmosets). After retrograde tracing (HRP) and histochemical studies of the muscle, we found that a great number of neurons, located mostly in the ventral part of the grey matter extended axons into the peripheral nerve graft. Some of these labelled neurons were motoneurons, which could established functionnal neuromuscular junctions. The muscle regeneration was effective but slower than already known in rat studies.

Animals↗

PubMed1996

[Expression of mRNA, interleukin-1 beta, interleukin 6 and tumor necrosis factor-alpha during regeneration of the sciatic nerve in rats after tissue loss].

Within the family of proinflammatory cytokines, some exhibit a neurotrophic activity in addition to their proinflammatory functions. However, their role in peripheral nerve regeneration processes is still poorly understood. This study presents the kinetics of expression of mRNAs for different cytokines, IL-1 beta, IL-6, TNF alpha and that of NGF included as control. It was carried out on the rat sciatic nerve regeneration using two models of nerve transection with a 7 mm loss of substance. Nerve regeneration took place through an autologous nerve grafting in the first model, and through a collagenous cylinder in the second one. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to quantify each mRNA of cytokine and that of actin beta gene considered as an endogenous internal standard. The results showed a peak in the expression of IL-1 beta mRNAs in both models at D2 (second bay after operation). This D2-peak was also observed for TNF alpha and IL-6, but only in the model of the cylinder. The level of IL-6 D2-peak was very high compared to the nearly complete absence of IL-6 mRNAs expression in non operated control nerves. According to these results, proinflammatory cytokines and especially IL-6 may play a major role in promoting peripheral nerve regeneration.

Animals↗

PubMed1994

Comparative effect of alpha-MSH and b-FGF on neurite extension of fetal rat spinal cord neurons in culture.

Basic fibroblast growth factor (b-FGF) and alpha melanocyte stimulating hormone (alpha-MSH) were tested for their ability to promote axonal elongation on E14 fetal rat spinal cord cell culture, and to support cell survival. A similar development of neurite was observed in alpha-MSH treated cultures or in control cultures, with an axonal length ranging from 87.50 microns to 195.60 microns on day 3. Complete cell death occurred after 6 days of incubation. Whatever the concentration of b-FGF used (0.312-2.5 ng/ml), a significant increase (1.2- to 1.4-fold) in neurite length was observed, with neuronal survival up to 9 days.

Animals↗

PubMed1994

Effect of basic fibroblast growth factor and alpha-melanocytic stimulating hormone on nerve regeneration through a collagen channel.

An experimental study on the rat sciatic nerve was performed to evaluate nerve regeneration through a collagen guide and to study the effects of alpha-melanocytic stimulating hormone (alpha-MSH) and basic fibroblast growth factor (b-FGF) in accelerating axonal elongation. After transection, nerves were repaired over a 7 mm gap using a placental collagen type IV guide. The channel was filled with either a b-FGF solution or an alpha-MSH solution or was produced with b-FGF incorporated into the guide. Four weeks later, only groups in which b-FGF had been injected or incorporated displayed a significant somatosensory evoked potential response. Histological and quantitative analysis of nerve fibres confirmed the existence of nerve continuity in groups receiving an alpha-MSH solution or a channel containing b-FGF. These results demonstrate that alpha-MSH in solution and b-FGF incorporated into a collagen type IV channel enhance peripheral nerve regeneration. However, at 4 weeks, only b-FGF (3 ng) restores functional activity.

Animals↗

PubMed1994

Establishment of adult rat Schwann cell cultures: effect of b-FGF, alpha-MSH, NGF, PDGF, and TGF-beta on cell cycle.

Mitotically active Schwann cells isolated from adult rat sciatic nerve segments were cultivated, using a bivariate BrdU/DNA flow cytometry analysis, to test the effect of b-FGF (10 ng/ml), alpha-MSH (10 ng/ml), NGF (10 ng/ml), PDGF-AB (10 ng/ml), and TGF-beta 1 (10 ng/ml) on the cell cycle. Compared to control or cholera toxin-treated cultures, no significant differences (P < 0.05; Newmann-Keuls test) were observed in the proportion of G0G1 cells, S cells, G2M cells, and in the LI when alpha-MSH, NGF, PDGF-AB, or TGF-beta 1 were present. The S phase duration varied from 6.16 +/- 0.24 to 7.86 +/- 2.6 h, and the deduced potential doubling time was estimated at between 46.70 +/- 7.09 and 56.05 +/- 7.55 h. In contrast, when b-FGF was added to the culture, the cell cycle was significantly modified, and the proportion of G0G1 cells decreased from 68-77% to 59-64%, while the proportion of S cells increased from 14-16% to 24.0-26.4%. Although S phase duration was not significantly changed (6.02 +/- 0.36 h), the 1.7- to 2.8-fold LI increase reduced the potential doubling time to 25.99 +/- 6.13 h. We conclude from these results that only b-FGF-induced adult rat Schwann cells dramatically reenter in cell cycle and that this growth factor may be an axonally derived signal-promoting mitogenesis after nerve injury.

Age Factors↗