Mamoru Uemura

The effect of quercetin delivery system on osteogenesis and angiogenesis under osteoporotic conditions

Bone regeneration under osteoporotic conditions with impaired angiogenesis, osteogenesis and remodeling represents a great challenge. In the present study, the effects of quercetin on proliferation, osteogenic differentiation and angiogenic factor secretion as well as on the osteoclastogenic factor secretion of ovariectomized (OVX) rat bone marrow-derived mesenchymal stem cells (rBMSCs) were first evaluated in vitro. The role of mitogen-activated protein kinase (MAPK) signaling pathways and the protein kinase B (AKT) signaling pathway in these processes was also investigated. Finally, hydroxyapatite (HA) bioceramic microspheres with a micro-nano hybrid surface (nHA bioceramic microspheres) were fabricated and used as drug delivery carriers of quercetin, and the ability to induce osteogenesis and angiogenesis in vivo was confirmed in an OVX rat critical-sized femur defect model. In vitro studies showed that quercetin significantly promoted cell proliferation, ALP activity and the expression of osteogenic and angiogenic factors of OVX rBMSCs as well as inhibited the expression of receptor activator of nuclear factor-κB ligand (RANKL) in a dose-dependent manner, with a concentration of 1 μM yielding the greatest effect. Moreover, the activation of the extracellular signal-regulated protein kinase (ERK), p38 and AKT signaling pathways was observed in quercetin-treated OVX rBMSCs, and the crosstalk among these signaling pathways was evident. Furthermore, the nHA bioceramic microspheres could efficiently release quercetin in a sustained manner, and quercetin loaded in the nHA bioceramic microspheres could promote new bone formation and blood vessel formation in vivo. The present study revealed that quercetin could promote osteogenesis and angiogenesis while inhibiting osteoclastogenesis both in vitro and in vivo under osteoporotic conditions. Moreover, HA bioceramic microspheres with a micro-nano hybrid surface could act as injectable drug delivery carriers of quercetin and could be applied for osteoporotic bone regeneration.

Analysis of MRI findings in minimum invasive treatment for habitual temporomandibular joint dislocation by autologous blood injection around the temporomandibular joint capsule.

The aim of this study was to investigate magnetic resonance imaging (MRI) findings following autologous blood injection (ABI) for habitual temporomandibular joint (TMJ) dislocation. MRI was performed one hour and four and twelve weeks after ABI, revealing three types of significant findings. The first type was similar to hematoma and/or joint effusion in the articular capsule of the TMJ (type I). The second showed sporadic and diffuse T2 emphasis around the TMJ capsule (type II). The third involved a decreased range of condyle movement compared to before ABI (type III). Furthermore, we analyzed the three types of significant MRI findings. At one hour after ABI, type I was Grade 0 in 0 of 14 patients, Grade 1 in 8, Grade 2 in 2, and Grade 3 in 4. Type II was seen in 9 of the 14 cases and type III in 8. After twelve weeks, all cases of type I were Grade 0, no type II cases were evident, and type III was seen in 11 cases. Injecting autologous blood into surrounding TMJ tissues is an important factor in ABI. Minimally invasive treatment for habitual TMJ dislocation using ABI around the TMJ capsule appears to represent a very effective and safe treatment.

Comparative study of the ramification patterns of the subclavian branches as the subclavian artery passes in front or behind the scalenus anterior muscle

We investigated the ramification patterns of four subclavian branches (i.e., vertebral artery, internal thoracic artery, thyrocervical trunk, and costocervical trunk) as the subclavian artery passes in front or behind the scalenus anterior muscle. The investigation was carried out on 56 cadavers (112 cases) during student dissection practice sessions at Osaka Dental University. In 110 of the 112 cases, the subclavian artery passed behind the scalenus anterior muscle. The pattern of ramification of the subclavian branches in these cases was classified into six types (types A–F). In the remaining two cases (two cadavers), the subclavian artery passed in front of the scalenus anterior muscle. In both of these latter cases, the pattern of ramification of the subclavian branches differed from the six pattern types observed as the subclavian artery passed behind the scalenus anterior muscle: the first branch was the vertebral artery; the second, the costocervical trunk; the third, the thyrocervical trunk; the fourth, the internal thoracic artery. This same pattern of ramification was observed in three previously reported cases (two cadavers) in which the subclavian artery passed in front of the scalenus anterior muscle. Taken together, these observations indicate that the ramification pattern reported here and in a previous investigation for the subclavian artery passing in front of the scalenus anterior muscle is characteristic of this anatomical condition.

Morphological Study of the Articular Disc and Capillary of the Retrodiscal Tissue in a Type 2 Spontaneous Diabetes Mellitus Rat Model.

The objective of this study was to evaluate morphological changes at the articular disc of the temporomandibular joint and capillary of the retrodiscal tissue in a rat model for type 2 spontaneous diabetes mellitus (DM) (i.e., Goto-Kakizaki [GK] rats) compared to normal Wistar rats. A total of 20 experimental rats were used in this study; the rats were categorized into the normal (n = 10 male 8-week-old Wistar rats) and DM (n = 10 male 8-week-old GK rats) groups. Hematoxylin-eosin stained specimens were obtained from 5 rats from each group. Image analyses of the hematoxylin-eosin stained specimens were conducted using light micrographs, which allowed comparisons of the thickness of the anterior, central, and posterior parts of the articular disc. Afterwards, the microvascular corrosion cast specimens were obtained from 5 rats from each group. The diameter of the capillary of the retrodiscal tissue was determined by analyzing scanning electron micrographs of the microvascular corrosion cast specimens. Students t-test was used to test for statistical significant differences between the 2 groups. Differences were considered significant when p < 0.01. We found that the thickness of the anterior, central, and posterior parts of the articular disc, and the diameter of the capillary of the retrodiscal tissue was significantly lower in the DM vs. normal group. Therefore, we consider that DM-associated the hyperglycemia causes atrophy of the articular disc and microangiopathy of the capillary of the retrodiscal tissue in GK rats.

Constant existence of the sensory branch of the nerve to the pyramidalis distributing to the upper margin of the pubic ramus

Twenty-one sides of 11 adult Japanese cadavers were investigated, and 2 of 21 sides exhibited absence of the pyramidalis. We observed that all of the nerves to the pyramidalis included the sensory nerve branch, which distributed to the aponeurotic tissue in the upper area of the pubic ramus. To investigate the clinical relevance and developmental process of the pyramidalis, detailed innervation patterns of the pyramidalis and the lumber plexus were examined and compared with the case of absent pyramidalis. The nerves to the pyramidalis could be classified into five types by the derivative nerves and two subtypes by their courses associated with the funiculus spermaticus. In the cases of absent pyramidalis, similar sensory branches distributed close to the upper area of the pubic ramus. We deduced that the sensory branch extended along with the muscular branch to the pyramidalis after development of the pyramidalis and that only the sensory branch remained in cases in which the pyramidalis disappeared. The two subtypes might associate with descensus testis. Surgeons performing inguinal hernia repair using a mesh and tension-free surgical technique should preserve the nerves around the funiculus spermaticus to avoid diminished proprioception in the lower abdominal wall.

Identification of the optimal method for removing the capsule from the acinus of the rat's mandibular glands when preparing specimens for superficial morphology examination

The superficial morphology of the acinus of the mandibular gland in rats, which corresponds to the submandibular gland in humans, is very difficult to observe under scanning electron microscope due to a closely adherent capsule. Therefore, we evaluated the most effective protocol for removing this capsule from the acinus using various solutions, at different temperatures and for different durations of soaking. Based on the data for 50 male Wistar rats, the most effective method was soaking in an 8 N hydrochloric acid solution at 60°C for 70 min, in a water bath, followed by soaking in a 0.1-0.2% collagenase solution at 37°C for 330-350 min.