Transplantation of meniscus regenerated by tissue engineering with a scaffold derived from a rat meniscus and mesenchymal stromal cells derived from rat bone marrow

Abstract:  The purpose of this study was to assess transplantation of regenerated menisci using scaffolds from normal allogeneic menisci and bone-marrow-derived mesenchymal stromal cells (BM-MSCs) of rats. We reported that scaffolds derived from normal menisci seeded with BM-MSCs in vitro could form meniscal tissues within 4 weeks. Then, we hypothesized that our tissues could be more beneficial than allogeneic menisci regarding early maturation and chondroprotective effect. Bone marrow was aspirated from enhanced green fluorescent protein transgenic rats. BM-MSCs were isolated and seeded onto scaffolds which were prepared from Sprague–Dawley rat menisci. After 4 weeks in coculture, the tissues were transplanted to the defect of menisci. Repopulation of BM-MSCs and expression of extracellular matrices were observed in the transplanted tissues at 4 weeks after surgery. At 8 weeks, articular cartilage in the cell-free group was more damaged compared to that in the cell-seeded group or the meniscectomy group.     

Telomerase Activity in Giant Cell Tumors of Bone

Background A giant cell tumor of bone (GCT) is a histologically benign neoplasma that has an unpredictable pattern of biological aggressiveness. In the present study, we investigated whether there was a correlation between telomere length or the levels of telomerase activity and other clinical features of GCTs, for the possible use of these factors as parameters of aggressiveness or prognosis. Methods In 16 surgically resected GCTs specimens, telomere length was assessed by terminal restriction fragments by Southern blot analysis. Telomerase activity was measured by a semiquantitative polymerase chain reaction–based telomeric repeat amplification protocol assay. Results Telomere length reduction was observed in 69% of the GCT samples. The telomere lengths of tumors were significantly shorter than those of normal tissue (P = .008). The mean telomere length of grade 3 tumors was significantly shorter than those of grade 1 and 2 tumors (P = .038). Telomerase activity was detected in 81% of tumor samples. The level of telomerase activity in tumors with local recurrence was significantly higher than in tumors without local recurrence (P = .011). Conclusions These results suggest that telomere length correlates with roentgenographic grade as a result of the frequency of cell division, and high telomerase activity indicates the aggressiveness of GCTs.     

Differentiation between intradural and extradural locations of juxta-dural ring aneurysms by using contrast-enhanced 3-dimensional time-of-flight magnetic resonance angiography

BACKGROUND: Juxta-dural ring aneurysms of the ICA have different clinical outcomes and risks for SAH, which are dependent on their position in the intradural or extradural space. The aim of this study was to reveal the precise location of such aneurysms by using CE-MRA. METHODS: Contrast-enhanced MRA studies were performed in 21 patients with 24 juxta-dural ring aneurysms. The locations were evaluated by source images of CE-MRA and MPR images. We evaluated the accuracy of preoperative MRI findings by comparing imaging results with intraoperative findings in 7 cases. RESULTS: The CS was clearly enhanced in the CE-MRA technique, which allowed the precise identification of these aneurysms as intradural or extradural. Intracavernous aneurysms were diagnosed when the greater hyperintensity of the aneurysm was located within the less hyperintense region of the contrast-enhanced CS. Nine of the cases were diagnosed as intradural aneurysms, and 15 aneurysms were noted as extradural based on the findings of CE-MRA. Surgery was performed in 7 cases, which included 4 intradural and 3 extradural aneurysms, and the preoperative MRI findings corresponded with the intraoperative findings in all cases. CONCLUSION: Contrast-enhanced MRA and MPR are very useful techniques for determining the location of juxta-dural ring aneurysms.     

Cyst wall resection and ablation by hand-assisted laparoscopic surgery combined with argon plasma coagulator for huge hepatic cysts

Six cases of deroofing of giant liver cysts by hand-assisted laparoscopic surgery (HALS) and safe and definitive cyst wall ablation with argon plasma coagulation (APC), which was verified by pathological examination of the resected cyst wall, were shown.     

The shape of the lateral edge of the first metatarsal head as a risk factor for recurrence of hallux valgus

BACKGROUND: The relationship between the shape of the first metatarsal head and hallux valgus deformity remains controversial. The purpose of the present study was to retrospectively analyze differences in the radiographic appearance of the shape of the lateral edge of the first metatarsal head between women with normal feet and those with hallux valgus and to clarify the relationship between the shape of the lateral edge and the postoperative recurrence of hallux valgus deformity. METHODS: Dorsoplantar weight-bearing radiographs of sixty normal feet in women (the control group) and sixty feet in women with hallux valgus (the hallux valgus group) were reviewed. The feet in the hallux valgus group were treated with a proximal metatarsal osteotomy, and the radiographs of those feet were assessed preoperatively, at the time of early follow-up (mean, 3.4 months), and at the time of the most recent follow-up (mean, forty-eight months). The shape of the lateral edge, which was defined as consisting of the articular and lateral surfaces of the first metatarsal head, was examined. The shape of the lateral edge was classified as one of three types: round (type R), angular (type A), and intermediate (type I). We defined the round sign as being positive when the shape of the lateral edge was classified as type R. RESULTS: Prior to surgery, the prevalence of the type-R shape was significantly greater in the hallux valgus group than it was in the control group (78.3% compared with 1.7%; p < 0.0001) and the prevalence of type-A shape was significantly lower in the hallux valgus group than in the control group (3.3% compared with 81.7%; p < 0.0001). In the hallux valgus group, the prevalence of the type-R shape at the time of the early follow-up after surgery was significantly lower than that before surgery (p < 0.0001). Feet with a positive round sign at the time of the early follow-up had a greater risk of having recurrence of the hallux valgus deformity at the time of the most recent follow-up than did those without a round sign at the time of the early follow-up (odds ratio, 12.71; 95% confidence interval, 3.21 to 50.36). CONCLUSIONS: There is a significant relationship between a round-shaped lateral edge of the first metatarsal head and hallux valgus, and a positive round sign after a proximal first metatarsal osteotomy can be a risk factor for the recurrence of hallux valgus.     

Simultaneous occurrence of subarachnoid hemorrhage due to ruptured aneurysm and remote brainstem hematoma--case report

A 48-year-old woman presented with simultaneous aneurysmal subarachnoid hemorrhage (SAH) and remote intracerebral hemorrhage manifesting as sudden onset of severe headache, left hemiparesis, and diplopia. Emergent computed tomography revealed localized SAH in the interpeduncular cistern, and a remote brainstem hematoma in the right dorsolateral tegment. Neuroimaging found no signs of vascular anomaly in the brainstem. The aneurysm at the basilar artery and superior cerebellar artery bifurcation was successfully embolized using coils. Her postoperative neurological status was improved except for slight diplopia. The causes of this extremely rare case of simultaneous occurrence of aneurysmal SAH and remote brainstem hematoma in the dorsolateral tegment remain obscure.     

Ocular melatonin rhythms in teleost fish

Melatonin (N-acetyl-5-methoxytryptamine) is synthesized in the pineal organ and the retina of vertebrates. In some teleost species, ocular melatonin levels can exhibit a circadian periodicity with elevated levels during the dark phase under light-dark (LD) cycles and this periodicity can persist even under constant dark (DD) cycles. However, reversed melatonin profiles and an absence of circadian ocular melatonin rhythms have also been reported. In this study, we investigated the daily rhythms of ocular melatonin in 32 teleost species under LD cycles. The melatonin profiles could be classified into three types: (1) normal profiles, with higher melatonin levels during the dark phase than the light phase; (2) reversed profiles, with higher levels during the light phase than the dark phase; (3) no significant differences in melatonin levels. We also studied whether ocular melatonin exhibits circadian rhythms under DD in selected species. Our results showed that ocular melatonin exhibited circadian rhythms in some but not all of the species examined. These results indicate that ocular melatonin rhythms in teleost fish exhibit species-specific variations as a result of the changes in the regulatory mechanisms during the course of evolution.     

Cerebellar activity evoked by common tool-use execution and imagery tasks: an fMRI study

The purpose of this study is to identify the functional brain networks activated in relation to actual tool-use in humans. Although previous studies have identified brain activity related to tool-use gestures (Moll et al., 2000), they did not investigate the brain activity involved in such tool-use. We investigated brain activity using functional magnetic resonance imaging (fMRI) while human subjects mentally imagined using sixteen common tools and while they actually used them. Brain activity for both actual and imagined tool-use was found in the posterior part of the parietal cortex, in the supplementary motor area, and in the cerebellum. Under imagined tool-use conditions, we found brain activity in the premotor and right pars opercularis. Under actual tool-use conditions, we found it in the primary motor area, in the thalamus, and in the left pars opercularis. Our precise analysis in the cerebellum indicated that activity evoked by imagery was located significantly more lateral to that evoked by actual use. We found a relationship between activity in the tool imagery and execution conditions by comparing their t-value-weighted centroid of activation coordinates. Moreover, for half of the subjects the spatial distribution pattern for each tool was similar, suggesting that neural mechanisms contributing to skillful tool-use are modularly organized in the cerebellum.     

Significant correlation between corticospinal tract conduction block and prolongation of central motor conduction time in compressive cervical myelopathy

We examined the relationship between the CMCT and features of spinal cord evoked potentials (SCEPs) among 25 patients with compressive cervical myelopathy to elucidate the mechanism underlying the prolonged central motor conduction time (CMCT) in patients with compressive cervical myelopathy. CMCT values were calculated by measuring motor evoked potentials from the abductor digiti minimi muscles (ADMs) and abductor hallucis muscles (AHs) following transcranial magnetic stimulation and peripheral conduction times determined in the ulnar and tibial nerves. SCEPs following transcranial electrical stimulation were recorded intraoperatively from C2-3, C6-7 and T11-12. The shorter/longer CMCTs between the patients' right and left ADMs and AHs were 9.5+/-3.2/11.5+/-3.8 and 16.2+/-2.8/18.8+/-3.3 ms, respectively (mean+/-SD). The percentage ratio of the amplitude of the D-wave at C6-7 or T11-12 to that at C2-3 was 19.4+/-14.2 or 3.2+/-3.1%, respectively. The CMCT value was significantly correlated with the attenuation of SCEP amplitude, but not with SCEP latency both at C6-7 and T11-12, suggesting that CMCT prolongation is primarily due to corticospinal conduction block rather than conduction delay. Spinal motor neurons might need more time to fire in patients with compressive cervical myelopathy when corticospinal potentials, but not conduction, are attenuated, thereby resulting in prolonged CMCT.