Re-innervation of the bladder through end-to-side neurorrhaphy of autonomic nerve and somatic nerve in rats

Restoration of the penile sensory pathway through end-to-side dorsal root neurorrhaphy in rats

Objective: Spinal cord injury often leads to the loss of penile sensation, and severely affects the individual's sexual function. The present study aimed to restore the penile sensory pathway through end-to-side dorsal root (DR) transfer neurorrhaphy in rats, and preliminarily verified the feasibility of the operation.Design: 40 male adult Sprague-Dawley rats were divided into three groups. In the model (n = 20) and resection (n = 10) groups, the right L6 DR, S1 DR, and the contralateral branch of the dorsal nerve of the penis (DNP) were transected. The distal stump of L6 DR in the model group was then anastomosed to the intact L4 DR. The sham group (n = 10) was not subjected to neural damage. Four months later, retrograde and transganglionic neural labeling, morphological examination, immunofluorescence (IF), and ultrastructural observation were carried out to test the reconstruction of the afferent pathway. Reflective erection (RE) was assessed by detecting the intracavernous pressure elicited by DNP stimulation.Results: The neural labeling tests indicated the integrity of the entire rebuilt penile afferent pathway. The morphological studies, IF, and ultrastructural observation showed that the regeneration of L6 axons in the model group was significantly better than that in the resection group; however, it had not reached the level of the sham group. The sham group rats exhibited typical RE following DNP stimulation, while the model and resection groups produced negative results.Conclusion: Our studies demonstrated the feasibility of end-to-side DR transfer neurorrhaphy for restoring the penile sensory pathway in rats.

The Neurotrophic Effects and Mechanism of Action for FK1706 in Neurorrhaphy Rat Models and SH-SY5Y Cells

FK1706 is a novel non-immunosuppressive immunophilin ligand with neurotrophic activity and exerts its neurotrophic effect through NGF. The present study aimed to elaborate on the neurotrophic activity and the mechanism of action of FK1706 in end-to-side neurorrhaphy rats and SH-SY5Y cells. In the regenerating nerves of neurorrhaphy rats, FK1706 increased the thickness of myelin sheath and the level of nerve regeneration-related proteins. The mechanism of action of FK1706 on neurite regrowth was elucidated in vitro by incubating SH-SY5Y cells in different conditions (Control, NGF, FK1706, NGF + FK1706, NGF + FK1706 + geldanamycin). Under the conditions where NGF was used, the phosphorylation level of major proteins (Raf-1 and ERK) in the Ras/Raf/MAPK/ERK signaling pathway related to SH-SY5Y cell proliferation was significantly enhanced following the application of FK1706. The number of viable cells, cell viability and neurite length of SH-SY5Y cells was maximal when NGF and FK1706 were used simultaneously. The binding level of HSP90 and Raf-1 in FK1706 group was the highest. These results indicated that FK1706 could significantly promote nerve regeneration after neurorrhaphy. The putative mechanism of action stated that FK1706 could promote the binding of HSP90 and Raf-1, make Raf-1 continue to be activated, thereby affecting key proteins in the Ras/Raf/MAPK/ERK signaling pathway related to the neurotrophic effects of NGF to promote the proliferation and neurite regrowth of nerve cells.

Restoration of Penile Sensation Through Neurological Bypass in Rats

OBJECTIVE

To explore the feasibility of the penile afferent pathway by the cutaneous branch of the genitofemoral nerve to the dorsal nerve of penile transfer in rats.

METHODS

A total of 54 male rats were randomly divided into model group (n = 18), resection group (n = 18), and sham group (n = 18). In the model group, the distal stump of bilateral DNP was anastomosed to the proximal stump of the bilateral CGN through end-to-end neurorrhaphy. In the resection group, bilateral DNP was severed and ligated, and no end-to-end anastomosis was performed. Only a surgical incision was made in the sham group, and no nerve injury was caused. After the operation, the feasibility of reconstructing the penile afferent pathway was explored by fluorescent-gold retrograde neural labeling. The intracavernous pressure assessment was then carried out. The morphological examination, histological staining of nerves, and ultrastructural observation were performed accordingly.

RESULTS

Fluorescent-gold labeled L1 and L2 neurons in the model group were positive. The mean ICP in the model group was (12.02 ± 2.03 mmHg), which is higher than the mean value in the resection group (0 mmHg, P < .05) but lower than that in the sham group (36.95 ± 5.33 mmHg; P < .05). The morphological studies, HE, and ultrastructure observation revealed that the regeneration of DNP axons in the model group was significantly better than that in the resection group yet did not reach the level of the sham group.

CONCLUSION

This experiment preliminarily proved the feasibility of restoration of the penile afferent pathway by CGN to DNP transfer in Rats.

Reinnervation of the rectum with transfer of the genital branch of the genitofemoral nerve to the pelvic nerve in rats

OBJECTIVE

The purpose of this study was to determine the feasibility of rectum reinnervation with transfer of a primarily genitofemoral nerve to the pelvic nerve in the rat.

METHODS

Thirty-six male rats were randomly divided into 3 groups: rats in the nerve transfer group (n = 12) were subjected to rectal denervation and then bilateral genitofemoral nerve–pelvic nerve transfer; rats in the nerve resection group (n = 12) underwent rectum denervation without nerve transfer; and rats in the control group (n = 12) underwent sham surgery. Rectum denervation was achieved by transection of the L-6 spinal nerves, the spinal nerves below L-6, and the pelvic nerve. Four months postoperatively, retrograde nerve tracing, regenerative nerve morphological examination, and rectal manometry assessment were performed.

RESULTS

Regenerative nerve morphological examination showed good axonal regeneration after genitofemoral nerve transfer. Nerve stimulation induced increased rectal pressures in 10 of 12 rats in the nerve transfer group. The mean rectal pressure in this group was 54.9 ± 7.1 mm Hg, which is higher than the mean value in the nerve resection group (5.5 ± 2.0 mm Hg) but lower than that in the control group (70.6 ± 8.5 mm Hg) (p < 0.05). The appearance of FluoroGold-labeled neurons in the L-1 and L-2 spinal cord segments in the nerve transfer group confirmed the formation of new neural pathways.

CONCLUSIONS

The results have demonstrated that genitofemoral nerve–pelvic nerve transfer can achieve nerve regeneration. In this animal model, the authors were able to reinnervate the rectum by nerve transfer.

Reconstruction of bladder function and prevention of renal deterioration by means of end-to-side neurorrhaphy in rats with neurogenic bladder

AIMS

To investigate the feasibility of restoring bladder function and prevention of renal deterioration by neurorrhaphy in rats with neurogenic bladder (NB).

METHODS

Forty-two rats were assigned to the end-to-side nerve coaptation group (ECG, n = 16), no nerve coaptation group (NCG, n = 16), and control group (CG, n = 10). In the ECG, the left ventral root (VR) and dorsal root (DR) of L6 and S1 were transected, and the distal stump of L6VR was sutured to the lateral face of L4VR. In the NCG, the left VR and DR of L6 and S1 were transected, but coaptation was not performed. In the CG, no operation was performed. Nerve regeneration, bladder function, and renal function were evaluated by FluoroGold (FG) retrograde tract tracing, cystometry, electrical stimulation, MRI, histology and biochemical assays.

RESULTS

In the ECG, FG-labeled neurons were observed in the left ventral horn of L4 spinal cord. There was a significant increase in intravesical pressure upon stimulation of the left L4VR proximal to the coaptation. Maximum cystometric capacity, post-void residual urine, bladder compliance and weight, serum creatinine, blood urea nitrogen, and fibrotic area of bladder and kidney were lower in the ECG than in the NCG, but higher than the CG. Hydronephrosis was noticed in ECG and NCG rats. Maximum detrusor voiding pressure was higher in the ECG and CG than in the NCG.

CONCLUSIONS

End-to-side neurorrhaphy is a useful method for restoring bladder function and preventing renal injury in rats with NB.

The effects of FK1706 on nerve regeneration and bladder function recovery following an end-to-side neurorrhaphy in rats

BACKGROUND

Immunophilin ligands are neuroregenerative agents binding to FK506 binding proteins, by which stimulate recovery of neurons in a variety of injury nerves. FK1706 is a novel immunophilin ligand which has neuroprotective and neuroregenerative effects but without immunosuppressive activity. At present, most reports about FK1706 in ameliorating nerve injury and functional recovery are limited to cavernous nerve injury and erectile function recovery. This study aimed to demonstrate the effects of FK1706 on nerve regeneration and bladder function recovery following an end-to-side neurorrhaphy in rat models.

METHOD

The numbers of regenerated myelinated axons of the pelvic parasympathetic nerve (PPN) in the three groups' rats (FK1706 + ETS, ETS and control groups) were evaluated. Their intravesical pressure (IVP), S100β and growth associated protein 43 (GAP43) expressions were also compared.

RESULTS

In FK1706 + ETS group, 90% the rats showed that the frequency of FG labeled neurons was larger than the 3.5 cutoff value, 100% the rats showed that the frequency of FG-FB double-labeled neurons was larger than the 5.5 cutoff value. The average maximum of IVP in FK1706 + ETS group reached 76.3% of the value in control group. Their average number of myelinated axons of regenerated PPN reached 80% of the amount in control group. The nerve regeneration-associated markers data indicated that the expression level of S100β and GAP43 in FK1706 + ETS group was approximately 2-fold higher than that of ETS group (P < 0.05).

CONCLUSIONS

After end-to-side neurorrhaphy, FK1706 effectively enhanced the nerve regeneration and bladder function recovery.

End-to-side neurorrhaphy repairs peripheral nerve injury: sensory nerve induces motor nerve regeneration

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve. It involves suturing the distal stump of the disconnected nerve (recipient nerve) to the side of the intimate adjacent nerve (donor nerve). However, the motor-sensory specificity after end-to-side neurorrhaphy remains unclear. This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy. Thirty rats were randomized into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve (mixed sensory and motor) as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve; (2) the sham group: ulnar nerve and cutaneous antebrachii medialis nerve were just exposed; and (3) the transected nerve group: cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied. At 5 months, acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group, and none of the myelinated axons were stained in either the sham or transected nerve groups. Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%. In contrast, no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment. These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

Predictors of acute symptomatic seizures after intracranial hemorrhage in infants

OBJECTIVE

To determine the prevalence of acute symptomatic seizures in infants with supratentorial intracranial hemorrhage, to identify potential risk factors, and to determine the effect of acute seizures on long-term morbidity and mortality.

DESIGN

Children less than 24 months with intracranial hemorrhage were identified from a neurocritical care database. All patients who received seizure prophylaxis beginning at admission were included in the study. Risk factors studied were gender, etiology, location of hemorrhage, seizure(s) on presentation, and the presence of parenchymal injury. Acute clinical and electrographic seizures were identified from hospital medical records. Subsequent development of late seizures was determined based on clinical information from patients' latest follow-up.

SETTING AND PATIENTS

Patients with idiopathic neonatal intracranial hemorrhage, premature infants, and those with prior history of seizures were excluded from analysis. Seventy-two infants met inclusion criteria.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty percent of infants had acute symptomatic seizures. The prevalence was similar regardless of whether etiology of hemorrhage was traumatic or nontraumatic. Seizures on presentation and parenchymal injury were independent risk factors of acute seizures (p = 0.001 and p = 0.006, respectively). Younger children and women were also at higher risk (p < 0.05). Twenty percent had electrographic-only seizures, and those with parenchymal injury trended toward an increased risk (p < 0.1). Acute seizures were not predictive of mortality, but nearly twice as many patients with acute seizures developed late seizures when compared with those without. Electrographic seizures and parenchymal injury were also predictive of development of late seizures (p < 0.001 and p = 0.013, respectively).

CONCLUSIONS

Despite seizure prophylaxis, infants with supratentorial intracranial hemorrhage are at high risk for acute symptomatic seizures. This is regardless of the etiology of hemorrhage. Younger patients, women, patients with parenchymal injury, and patients presenting with seizure are most likely to develop acute seizures. Although the benefits of seizure prophylaxis have not been studied in this specific population, these results suggest that it is an important component of acute care following intracranial hemorrhage.