An efficient i-GONAD method for creating and maintaining lethal mutant mice using an inversion balancer identified from the C3H/HeJJcl strain.

As the efficiency of the clustered regularly interspaced short palindromic repeats/Cas system is extremely high, creation and maintenance of homozygous lethal mutants are often difficult. Here, we present an efficient in vivo electroporation method called improved genome editing via oviductal nucleic acid delivery (i-GONAD), wherein one of two alleles in the lethal gene was selectively edited in the presence of a non-targeted B6.C3H-In(6)1J inversion identified from the C3H/HeJJcl strain.

Spinal anesthesia for muscle biopsy in an infant with a suspected neuromuscular disorder: a case report.

Background: Neuromuscular disorders (NMDs) occur in different forms and are generally diagnosed using muscle biopsy. Among the available anesthetic management options for infants with a suspected NMD are general anesthesia (GA) and regional anesthesia (RA), including spinal anesthesia (SA). Anesthesia selection is often challenging from the point of potential airway risks and anesthetic drug-related complications.

Identification and characterization of the precursors committed to osteoclasts induced by TNF-related activation-induced cytokine/receptor activator of NF-kappa B ligand.

Osteoclasts are terminally differentiated from cells of monocyte/macrophage lineage by stimulation with TNF-related activation-induced cytokine (TRANCE) (receptor activator of NF-kappaB ligand/osteoprotegerin ligand/osteoclast differentiation factor/TNFSF11/CD254). In the present study, we attempted to determine when and how the cell fate of precursors becomes committed to osteoclasts following TRANCE stimulation. Although mouse bone marrow-derived macrophages (BMMs) were able to differentiate into either osteoclasts or dendritic cells, the cells no longer differentiated into dendritic cells after treatment with TRANCE for 24 h, indicating that their cell fate was committed to osteoclasts.

Differentiation and function of osteoclasts cultured on bone and cartilage.

We examined the differentiation and resorptive function of osteoclasts (OC) cultured on the slices of calcified bone, decalcified bone and hyaline cartilage, and found that OC differentiation depends on the co-cultured substratum, as well as osteoblast-derived factors. Bone marrow-derived macrophages (BMM) were formed from marrow cells of 5 week old ddY mice and cultured for 3 days on freeze-dried slices of calcified bone, decalcified bone or cartilage, all prepared from rabbit costal bone. BMM cultured on calcified bone slices exhibited tartrate-resistant acid phosphatase (TRAP) activity and were structurally characterized by multinucleation and ruffled border development.

Effects of osteoprotegerin administration on osteoclast differentiation and trabecular bone structure in osteoprotegerin-deficient mice.

Osteoprotegerin (OPG)-deficient mice exhibit severe bone loss including the destruction of growth plate cartilage. Using OPG-deficient mice, we attempted to clarify the differentiation and ultrastructure of osteoclasts located on the destroyed growth plate cartilage and trabecular bone matrix in long bones. In (-/-) homozygous OPG knockout mice, adjacent to the growth plate cartilage, the formation of bone trabeculae without a calcified cartilaginous core resulted in an irregular chondrocyte distribution in the growth plate cartilage.

[Differentiation of osteoclasts].

The differentiation and functions of osteoclasts (OCs) are regulated by osteoblast-derived factors such as receptor activator of NF kappa; B ligand (RANKL) that stimulates OC formation and a novel secreted member of the TNF receptor superfamily, osteoprotegerin (OPG), that negatively regulates osteoclastogenesis. Preosteoclasts (pOCs) treated with RANKL became TRAP-positive OCs, which express vacuolar-type H (+) -ATPase and exhibit resorptive activity. Such effects of RANKL on pOCs are inhibited by OPG.

Osteoclast differentiation and characteristic trabecular bone formation during growth plate destruction in osteoprotegerin-deficient mice.

Osteoprotegerin (OPG) is an osteoblast-derived secreted member of the tumour necrosis factor receptor superfamily that inhibits osteoclastogenesis. Mice that are OPG-deficient have severe bone loss, including growth plate cartilage destruction. Using OPG-deficient mice as a useful animal model, we attempted to clarify differentiation and ultrastructural features of osteoclasts located on destructed growth plate cartilage and trabecular bone matrix.

Osteoclast differentiation at growth plate cartilage-trabecular bone junction in newborn rat femur.

Using 3-day-old newborn rats, we examined the differentiation processes of osteoclasts associated with the destruction of the femoral growth plate cartilage and primary trabecular bone. In the growth plate cartilage, thin mineralized areas were detected solely in the longitudinal septal cartilage matrix in the hypertrophic zone, but the transverse septal cartilage matrix between adjacent chondrocytic lacunae within a row of chondrocytes remained unmineralized. The longitudinal septal cartilage between adjacent rows of chondrocytes appeared to persist, forming the walls of opened lacunar canals.

Cellular mechanism of inhibition of osteoclastic resorption of bone and calcified cartilage by long-term pamidronate administration in ovariectomized mature rats.

We examined the effects of long-term bisphosphonate (BP, pamidronate) administration at a therapeutic dose (1.5 mg/kg/day) on the distribution, structure, and vacuolar-type H(+)-ATPase expression of osteoclasts, and the resulting trabecular bone volume and structure in ovariectomized (OVX) mature rats. Six-month-old female rats were allocated to sham-operated control, untreated-OVX, and BP-administered OVX groups.

Differentiation and functions of osteoclasts and odontoclasts in mineralized tissue resorption.

The differentiation and functions of osteoclasts (OC) are regulated by osteoblast-derived factors such as receptor activator of NFKB ligand (RANKL) that stimulates OC formation, and a novel secreted member of the TNF receptor superfamily, osteoprotegerin (OPG), that negatively regulates osteoclastogenesis. In examination of the preosteoclast (pOC) culture, pOCs formed without any additives expressed tartrate-resistant acid phosphatase (TRAP), but showed little resorptive activity. pOC treated with RANKL became TRAP-positive OC, which expressed intense vacuolar-type H(+)-ATPase and exhibited prominent resorptive activity.

Porcine enamel matrix derivative enhances the formation of reparative dentine and dentine bridges during wound healing of amputated rat molars.

We examined the biological effects of porcine enamel matrix derivative (EMD; Emdogain) on the formation of reparative dentine and dentine bridges in rat molars after pulp amputation. The pulp chambers of upper molars of Wistar rats were perforated and the amputated pulp surfaces were directly capped with either EMD or its carrier propylene glycol alginate (PGA) as control. The cavities were then restored with glass-ionomer cement.

Effects of enamel matrix derivative on mineralized tissue formation during bone wound healing in rat parietal bone defects.

Enamel matrix derivative (EMD: Emdogain) has been reported to stimulate the biosynthesis and regeneration of trabecular bone. To address whether the biological action of EMD is dependent on the local environment of osseous tissue, circular perforations were made in parietal bones and immediately filled with either EMD or its carrier, propylene glycol alginate (PGA), as control. On post-operative days 4-60, the dissected bones were examined by various histological techniques.

Specific biological functions of vacuolar-type H(+)-ATPase and lysosomal cysteine proteinase, cathepsin K, in osteoclasts.

We report the effects of specific and potent inhibitors of vacular-type H(+)-ATPase and lysosomal cysteine proteinases, cathepsins, on the ultrastructure, expression of these enzymes, and resorptive functions of cultured osteoclasts. Osteoclasts were formed by co-culture of marrow cells and calvarial primary osteoblasts of ddY mice. Formed osteoclasts were cultured on dentine slices for 6-48 hr with either an H(+)-ATPase inhibitor, bafilomycin A1, or a cysteine proteinase inhibitor, E-64.

Osteoprotegerin administration reduces femural bone loss in ovariectomized mice via impairment of osteoclast structure and function.

Osteoprotegerin (OPG) is a novel osteoblast-derived secreted member of the tumour necrosis factor receptor superfamily that inhibits osteoclastogenesis. We examined the effects of OPG administration on the distribution, ultrastructure and vacuolar-type H+-ATPase expression of osteoclasts and resulting trabecular bone loss in the femurs of ovariectomized (OVX) mice. Two-month-old female ddY mice were allocated to the following groups: (1) pretreatment base-line controls; (2) untreated sham-operated controls; (3) untreated OVX; and (4) OPG-administered OVX mice.

Regulation of osteoclast differentiation and function by receptor activator of NFkB ligand and osteoprotegerin.

The differentiation and functions of osteoclasts (OCs) are regulated by osteoblast-derived factors. Receptor activator of NFkB ligand (RANKL) is one of the key regulatory molecules in OC formation. Osteoprotegerin (OPG) is a novel secreted member of the TNF receptor superfamily that negatively regulates osteoclastogenesis and binds to RANKL.

Osteoclast induction in periodontal tissue during experimental movement of incisors in osteoprotegerin-deficient mice.

Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor (TNF) receptor superfamily that negatively regulates osteoclastogenesis. The receptor activator of the NFKB ligand (RANKL) is one of the key regulatory molecules in osteoclast formation and binds to OPG. In this study, it was suggested that OPG and RANKL are involved in alveolar bone remodeling during orthodontic tooth movement.

Effects of enamel matrix derivative to titanium implantation in rat femurs.

The effects of enamel matrix derivative (EMD; Emdogain) on new trabecular bone induction after pure bioinert titanium (Ti) implantation in the rat femur were examined by means of routine light and transmission electron microscopy, immunohistochemistry, and backscattered electron image analysis. Newly designed mini-Ti implants (3.5 mm in length and 1.