Repairing whole facial nerve defects with xenogeneic acellular nerve grafts in rhesus monkeys

Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically, both in terms of branching a single trunk and in connecting multiple branches of an extratemporal segment. However, in the clinical treatment of facial nerve defects, allogeneic donors are limited. In this experiment, we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve defect. Six monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft group. In the autograft group, the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve, and in the xenogeneic acellular nerve graft group, this was done using a xenogeneic acellular nerve graft with trunk-branches. Examinations of facial symmetry, nerve-muscle electrophysiology, retrograde transport of labeled neuronal tracers, and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement, and that they could actively close their eyelids completely. The degree of recovery from facial paralysis reached House-Brackmann grade II in both groups. Compound muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each monkey. FluoroGold-labeled neurons could be detected in the facial nuclei on the injured side. Immunohistochemical staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves. A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron microscope. Taken together, our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effective for repairing whole facial nerve defects in rhesus monkeys, with an effect similar to that of autologous nerve transplantation. Thus, a xenogeneic acellular nerve graft may be a suitable choice for bridging a whole facial nerve defect if no other method is available. The study was approved by the Laboratory Animal Management Committee and the Ethics Review Committee of the Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, China (approval No. 2018-D-1) on March 15, 2018.

Dynamic tracking of pathogenic receptor expression of live cells using pyrenyl glycoanthraquinone-decorated graphene electrodes

Expression of specific transmembrane receptors by cells frequently represents an important signature of diseases, but this dynamic event can hardly be monitored directly with live cells due to the limitation of current biochemical techniques. Here we develop a pyrenyl glycoanthraquinone construct that can be firmly immobilized on a graphene-spotted screen printed electrode via strong π-interactions. The inherent current signal produced by the surface-confined glycoquinone can be used to detect selective sugar-protein recognitions with simple electrochemical techniques and portable facilities. Importantly, we demonstrate that the level of pathogenic receptors expressed by different types of live cells can be tracked with the electrode system in a label-free manner, providing a useful tool for the on-demand disease diagnosis as well as basic biochemical studies.

Anthraquinonyl glycoside facilitates the standardization of graphene electrodes for the impedance detection of lectins

Background

Construction of electrochemical impedance sensors by the self-assembly technique has become a promising strategy for the ‘label-free’ detection of protein-ligand interactions. However, previous impedance sensors are devoid of an inherent electrochemical signal, which limits the standardization of the sensors for protein recognition in a reproducible manner.

Results

We designed and synthesized an anthraquinonyl glycoside (AG) where the anthraquinone (AQ) moiety can bind to the surface of a graphene-based working electrode while the glycoside serving as a ligand for lectin. By measuring the inherent voltammetric signal of AQ, the glycosides decorated on the working electrode could be simply quantified to obtain electrodes with a unified signal window. Subsequently, impedance analysis showed that the ‘standardized’ electrodes gave a reproducible electrochemical response to a selective lectin with no signal variation in the presence of unselective proteins.

Conclusion

Anthraquinone-modified ligands could be used to facilitate the standardization of electrochemical impedance sensors for the reproducible, selective analysis of ligand-protein interactions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13065-014-0067-y) contains supplementary material, which is available to authorized users.

Effect of octreotide on anal pressure and rectal compliance

PURPOSE

The somatostatin analog, octreotide, has previously been found to influence rectal sensation and may also influence anal resting pressure.

METHODS

We studied the effect of octreotide on anal resting pressure and rectal compliance in eight healthy patients. Octreotide was administered intravenously as a bolus injection in doses of 100 and 10 micrograms or as infusion of 250 micrograms/hour on separate days and compared with placebo.

RESULTS

Within one minute after a bolus injection of 100 micrograms of octreotide, anal resting pressure increased from 56 +/- 12 to 96 +/- 16 cm H2O (P < 0.005). Octrotide had no effect on rectal sensitivity or compliance measurements. Octreotide counteracted rectoanal reflex by increasing anal pressure almost to the level found with an empty rectum.

CONCLUSION

Somatostatin thus seems to contribute to the regulation of rectoanal reflex.

Peritoneal carcinomatosis from appendiceal cancer: results in 69 patients treated by cytoreductive surgery and intraperitoneal chemotherapy

Sixty-nine patients presenting over a 10-year period with peritoneal carcinomatosis from appendiceal cancer were treated with cytoreductive surgery combined with intraperitoneal chemotherapy. The three-year survival is 89.5 percent in patients (38/69) with pseudomyxoma peritonei, 34.5 percent in patients (25/69) with cystadenocarcinoma, and 38.1 percent in patients (6/69) with adenocarcinoma (P < 0.01). In this study, a classification of residual disease following the cytoreductive surgery was used. The prognosis of the patients with minimal residual disease was better than that of those with moderate or gross disease, showing a 91.6 percent three-year survival compared with 47.8 percent and 20 percent, respectively (P < 0.01). The patients without lymphatic or hematogenous metastases had a better three-year survival than those with metastases (75.1 percent vs. 28.6 percent; P < 0.01). These findings suggest that peritoneal carcinomatosis from appendiceal cancer can be treated with long-term disease-free survival. The patients with low malignant potential cancer, complete cytoreduction, and no metastases showed the most effective disease control.

Internal rectal intussusception: results of surgical repair

Twenty-four patients with obstructed defecation due to rectal intussusception diagnosed by defecography were treated with rectopexy either by the Wells technique (9 patients) or by Orr's operation (15 patients). After follow-up from one to eight years, defecography demonstrated disappearance of the intussusception in 22 patients. None of the patients were completely relieved of their symptoms. Nine (41 percent; 95 percent confidence limits: 21-64) were improved and 13 were unchanged (59 percent; 95 percent confidence limits: 36-79), with no difference between the two procedures. One patient with solitary rectal ulcer was improved, and the ulcer disappeared. Four patients with moderate preoperative incontinence became continent postoperatively, but obstructed defecation was only improved in two of these patients. It is concluded that rectal intussusception is probably a secondary phenomenon in patients with obstructed defecation and that a conservative attitude toward surgery should be adopted.