Matrix metalloproteinases (MMPs) of regenerating urodele limbs have been suggested to play crucial roles in the process of the dedifferentiation of cells in the damaged tissues and the ensuing blastema formation because the activation of MMPs is an early and conspicuous event occurring in the amputated limb. MMP cDNAs were cloned as products of the reverse transcription-PCR from cDNA libraries of newt limbs, and their structures were characterized. Three cDNAs encoding newt MMPs (2D-1, 2D-19, and 2D-24) have been cloned from second day postamputation regenerating limbs, and a cDNA (EB-1) was cloned from early bud-stage regenerating limbs. These cDNAs included the full-length coding regions. The deduced amino acid sequences of 2D-1, 2D-19, 2D-24, and EB-1 had a homology with mammalian MMP9, MMP3/10, MMP3/10, and MMP13, respectively. The basic motif of these newt MMP genes was similar to mammalian counterparts and contained regions encoding a putative signal sequence, a propeptide, an active site with three zinc-binding histidine residues, a calcium-binding domain, a hemopexin region, and three key cysteine residues. However, some unique molecular evolutionary features were also found in the newt MMPs. cDNAs of 2D-19 and 2D-24 contained a specific insertion and deletion, respectively. The insertion of 2D-19 is threonine-rich, similar to the threonine cluster found in the collagenase-like sea urchin hatching enzyme. Northern blot analysis showed that the expression levels of the newt MMPs were dramatically increased after amputation, suggesting that they play an important role(s) in tissue remodeling of the regenerating limb.Limbs of adult urodele exhibit a remarkable ability to restore missing parts when they are accidentally lost and have provided investigators with an ideal experimental model to study the mechanism of the complete restoration of original pattern (1, 2). Generally, limb regeneration proceeds through five steps: (i) formation of wound epidermis, (ii) dedifferentiation of cells under the wound epidermis, (iii) formation of blastema, (iv) growth and differentiation of the blastema, and (v) pattern reformation. Dedifferentiation and blastema formation are unique features of urodele limbs and are of prime importance in the initial phase of regeneration (1, 2). The breakdown of interstitial connective tissues, cartilages, bones, and muscles under the wound epidermis seems to be a trigger of the dedifferentiation of liberated cells, because these cells start to lose the morphologic characteristics of their differentiated state concomitantly with the tissue demolition (2).It has been generally accepted that extracellular matrix (ECM) molecules rapidly turn over during processes involving tissue remodeling, such as wound healing, metamorphosis, and regeneration (2-4). ECM is thought to stabilize the differentiated state of cells and support the expression of their normal tissue-specific phenotypes (5, 6). Consequently, the degradation of the ECM destabilizes the differentiated state and would b...

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The SS and LL were greater in patients with DDH than in patients with hip pain, but without DDH. Patients with DDH might show lumbar hyperlordosis to rotate the pelvis anteriorly, increasing the anterosuperior acetabular coverage.

In the present study, in order to enable effective utilization of scallop shells, the in vitro activities of components that were extracted from scallop shells were investigated. In particular, the scallop shell's useful ability to protect skin was evaluated. The following were found: (i) scallop shell extract inhibited generation of the superoxide anion, which was generated by xanthine and xanthine oxidase; (ii) when the scallop shell extract was supplied to culture medium for skin fibroblast cells, the cell growth rate was increased; and (iii) the scallop shell extract showed strong inhibitory activities for elastase. In the present paper, we describe the possibility of the effective utilization of scallop shells as cosmetics.

BackgroundFemoroacetabular impingement (FAI) is one factor known to cause pain and osteoarthritis (OA) of the hips. Although secondary OA due to hip dysplasia is common among Japanese populations, primary OA is seldom observed. Concomitantly, FAI is also thought to be uncommon in Japan, but relatively few epidemiological studies have addressed this issue. This study aimed to clarify the prevalence of radiographic findings of FAI in a Japanese population and to evaluate whether FAI is a risk factor for the development of arthritic changes.MethodsWe retrospectively examined 87 patients who underwent unilateral hip osteotomy with a Charnley category A hip joint on the contralateral side. Anteroposterior-view radiographs of the non-operated hip joint were assessed for the presence of hip dysplasia, as well as pistol grip deformity and crossover sign indicative of cam-type and pincer-type impingement, respectively. The presence of arthritic changes in the non-operated hip joint was assessed in follow-up radiographs, and factors contributing to the development of arthritis were determined by survival analysis.ResultsOf the 87 hips examined, dysplasia was noted in 38 (43.6%). While no pistol grip deformity was observed, crossover sign, which is indicative of pincer-type impingement, was identified in 9 of 38 dysplastic hips (23.7%) and 15 of 49 non-dysplastic hips (30.6%). Arthritic changes were present in 13 of 38 dysplastic hips (34.2%) and 11 of 49 non-dysplastic hips (22.4%). Survival analysis revealed that the presence of the crossover sign in non-dysplastic hips was significantly associated with the development of arthritis.ConclusionsThe prevalence of the crossover sign in hips in a Japanese population is similar to that reported in Western populations, despite the fact that FAI is believed to be less prevalent in the Japanese population. Furthermore, the presence of the crossover sign in non-dysplastic hip joints is associated with the development of arthritis. Based on our results, pincer-type impingement could be commonly associated with the development of arthritis in Japanese populations.