Nerve regeneration across a 25-mm gap bridged by a polyglycolic acid-collagen tube: a histological and electrophysiological evaluation of regenerated nerves

In the study reported here we have examined the nerve regeneration that occurs over a 25-mm gap using a novel biodegradable nerve guide tube. The tube was a composite of polyglycolic acid (PGA) mesh coated with collagen which was filled with neurotrophic factors. The left sciatic nerve of ten adult cats was dissected. The stumps were connected by the tube, and fixed gap. Histological examinations carried out 4–16 months after implantation of the tube revealed regeneration of well vascularized nerve tissue. Regeneration of both myelinated, unmyelinated axons and Schwann cells was confirmed by electron microscopy 5 months after surgery. Following injection of horseradish peroxidase (HRP) into a site peripheral to the regenerated segment of the sciatic nerves, motoneurons in the ventral horn of the spinal cord, afferent terminals in the medial portion of the dorsal column of the medulla oblongata, and sensory afferent nerve terminals in the dorsal horn of the spinal cord were labelled. Electrophysiological examinations revealed restoration of evoked electromyograms and sensory evoked potentials (SEPs) recorded from the cerebral cortex as well as the spinal cord. We also found that some of the regenerated motor axons exhibited branching in the regenerated segments. In two cases, a single motoneuronal axon from the regenerated side projected to both flexors and extensors, simultaneously. Our results indicate that the PGA-collagen composite tube is a promising tool for use as a nerve guide tube in peripheral nerve regeneration.     

不同产地和不同采收期黄芩中黄酮类成分的高效液相色谱法定量分析

用反相ODS术，磷酸缓冲溶液和甲醇（68：32和1：1）作为流动相，对中国七个省产的黄芩和辽宁同一产地不同采收期（1990－1992）黄芩中黄芩甙、黄芩素、汉黄芩甙和汉黄芩素四种主要的有效成分进行了定量分析。实验结果表明，河北承德地区野生黄芩中四种成分的含量最高，辽宁凌源野生黄芩的最佳采收期应为8月末。     

Action of enpiprazole on emotional behavior induced by hypothalamic stimulation in rats and cats

Action of enpiprazole on emotional behavior elicited by hypothalamic stimulation in rats and cats was investigated and comparisons were made with effects of diazepam. Two behavioral patterns were elicited by stimulation of the postero-medial part of the hypothalamus in rats: a food-carrying response beginning with exploratory movement and an analogue of fear. Enpiprazole frequently changed the food-carrying response into food-taking response and occasionally analogues of fear into food-carrying and/or food-taking responses. Thresholds for these behaviors were also elevated. Diazepam showed the same effects on the thresholds as enpiprazole, having but little effect on the behavioral patterns.In cats, enpiprazole elevated the thresholds for affective-defensive responses induced by hypothalamic stimulation in 6 of 8 cases, but lowered them in 2 cases. This suggests that enpiprazole has a biphasic effect in the central nervous system. By contrast, diazepam consistently elevated thresholds. Comparing the action of enpiprazole with that of diazepam it can be presumed that the former is a different type of anxiolytic drug than the latter.     

A questionnaire to assess olfactory rehabilitation for laryngectomized patients (Provox voice prosthesis users) in Japan

Objective

We used a questionnaire to investigate olfactory function and the present state of olfactory rehabilitation for laryngectomized patients in Japan.

Focal nodular hyperplasia: our experience of 53 Japanese cases

Purpose

Contrast-enhanced ultrasound (CEUS) is a very sensitive diagnostic tool in characterizing liver tumors. It is especially useful in the diagnosis of focal nodular hyperplasia (FNH) of the liver. According to the previous reports, FNH is common in young women, and it is usually diagnosed by MRI. The majority of the previous reports come from European countries, and a very few studies of large series designed to describe the clinical features in Japanese patients have been reported. The aim of this study was to (a) describe the clinical features in 53 patients (59 lesions) diagnosed with CEUS and (b) compare the data with those from the previous reports.

Methods

The medical data from 53 patients diagnosed on the basis of typical CEUS findings at our institution and affiliated hospitals were reviewed, and their clinical data were analyzed.

Results

(1) The medical data from 53 cases showed a slight male predilection, with 30 male cases (57 %) and 23 female cases (43 %), although the occurrence in both sexes was equal. FNH cases were distributed throughout all generations in both sexes, mostly concentrated in the age of 30–60 years old, and metabolic cases were more common in men than in women (4 vs 0). (2) The lesions were small (mean: 23 mm) and distributed throughout the whole liver. (3) Lesion size was not influenced by age in either sex. (4) A rapid draining to the hepatic vein was recognized in five out of 59 lesions (8 %).

Conclusions

Our data indicate that FNH occurs slightly more frequently in men than in women in Japan. It occurs also at any age in both sexes, but the mean lesion size was smaller in our series than in the previous reports. Metabolic disease was seen only in male FNH patients. A direct communication between the FNH lesion and the hepatic vein is diagnostically worth noting.

     

Evaluation of collagen nerve guide in facial nerve regeneration

Facial nerve paralysis due to resection of tumors or as a consequence of trauma is a frequently observed complication. Thus, in the present study, we evaluated a collagen nerve guide in facial nerve regeneration across a 5-mm nerve gap. This biological tube was manufactured from 3% collagen, coated over a Teflon tube used only as a template and submitted to thermal dehydration at 105°C for 24h. The collagen tube was implanted at the dorsal ramous of the facial nerve of five adult cats over a gap of 5mm. The facial nerve of the contralateral side was kept intact and used as control. Electrophysiological study was performed from 3 weeks after surgery, and histological and horseradish peroxidase labeling examination was carried out 8 weeks after implantation. Electrophysiological study confirmed the recovery of electrical activity of the collagenimplanted regenerated nerve. Light-microscopic examination of collagen tube-implanted specimens revealed a well vascularized regenerated nerve, which under an electron microscope showed many myelinated axons surrounded by Schwann cells and unmyelinated axons. Horseradish peroxidase staining demonstrated labeling of facial motoneurons in the brainstem and facial nerve terminals in the neuromuscular junction, also confirming restoration of the whole facial nerve tract from the reinnervated muscles, passing through the regenerated site to the brainstem. The collagen tube was very efficient as a nerve guide over a 5mm facial nerve gap and shows great promise as a nerve conduit.     

Establishment of a GFP-based indicator cell line to quantitate feline foamy virus

To quantitate infectious feline foamy virus (FeFV), Crandell feline kidney (CRFK) cells were transfected with the gfp gene under the control of the FeFV long terminal repeat (LTR) for establishing an indicator cell line named FFG cells. The FeFV activates promoter activity of the LTR to express green fluorescent protein (GFP) upon infection. The titers determined by GFP-positive FFG cells (GFP-based assay) were higher than those determined by the cytopathic effects-positive CRFK cells (CPE-based assay). The titers determined by the GFP-based assay reached a plateau at 3-4 days post infection (d.p.i.), while those by the CPE-based assay reached 6-8 d.p.i. When stock viruses of various FeFV strains were titrated by both assays, titers determined by both assays correlated well with each other. The results show that the GFP-based assay is simpler and more rapid and sensitive than the CPE-based assay. Using the GFP-based assay, we examined the in vitro host range of FeFV. It was found that FeFV can productively infect various cell lines derived from cats, dogs, chickens, a human and a bat.     

GIANT LYMPH NODE HYPERPLASIA IN EXTRATHORACIC LYMPH NODES-REPORT OF TWO CASES WITH A REVIEW OF THE LITERATURE

Two cases of giant lymph node hyperplasia occurring in extrathoracic regions are reported, one on the right side of the supra-and infraclavicular fossa, pectoral muscle and axilla, and the other in the right groin. In both cases enlarged masses were removed several times having arisen from slow growing preexisting smaller masses. The histological features of all masses were identical, although removed at different times during the course of the disease. Both cases were characterized by marked proliferation of lymphoid follicles and capillaries, and infiltration of plasma cells. Fibrous thickening and hyalinization of the capillaries varied somewhat in severity from one case to the other. It is thought that the histogenesis of the lesion is related to chronic inflammation rather than to a hamartoma.     

Application of biodegradable dendrigraft poly-l-lysine to a small interfering RNA delivery system

Dendrigraft poly-l-lysine (DGL), including its central core, consists entirely of lysine, hence it is completely biodegradable. We applied DGL in a small interfering RNA (siRNA) delivery system. Binary complexes with siRNA and DGL had particle sizes of 23–73?nm and ζ-potentials of 34–42?mV. The siRNA-DGL complexes showed significant silencing effects in a mouse colon carcinoma cell line expressing luciferase (Colon26/Luc cells). The siRNA-DGL complexes induced slight cytotoxicity and hematological toxicity at a high charge ratio of DGL to siRNA, probably because of their cationic charges. Therefore, we recharged the siRNA-DGL complexes with γ-polyglutamic acid (γ-PGA), a biodegradable anionic compound, which was reported to reduce the cytotoxicity of cationic complexes. The ternary complexes showed particle sizes of 35–47?nm at a charge ratio of greater than 14 to siRNA with negative charges. Strong silencing effects of the ternary complexes were observed in Colon26/Luc cells without cytotoxicity or hematological toxicity. The cellular uptake and degradation of the binary and ternary complexes were confirmed by fluorescence microscopy. The ternary complexes suppressed luciferase activity in the tumor after direct injection into the tumors of mice bearing Colon26/Luc cells. Thus, a potentially important siRNA delivery system was constructed using biodegradable DGL.     

Increased Fluorodeoxyglucose-Uptake in Positron Emission Tomography with an Endobronchial Schwannoma Occluding the Left Main Stem Bronchus

A 48-year-old woman suffering from left-side back pain and a 3-year history of coughing was found to have a submucosal lesion occluding the left main bronchus by chest computed tomographic scanning and bronchoscopy. The lesion showed a high standardized uptake value of 3.9 in positron emission tomography with fluorine-18 labeled fluorodeoxyglucose scanning (FDG-PET). The tumor was resected with the posterior wall of the left main bronchus through a postrolateral thoracotomy, and a large defect in the membranous portion was reconstructed in the manner of wedge bronchoplasty, preserving the lung parenchyma. Pathological findings confirmed the diagnosis of schwannoma with no malignant cells. Schwannoma should be included in the differential diagnosis of endobronchial tumors with high standardized uptake values in FDG-PET.