Biomedical subjects

Kenji Okuda

Publications and source records attributed to Kenji Okuda.

57 records · Page 4Linked to original sources

PubMed2002

Slow-releasing potential of vancomycin-loaded porous hydroxyapatite blocks implanted into MRSA osteomyelitis.

Although antibiotic-loaded hydroxyapatite blocks have been used for the treatment of chronic osteomyelitis, their long-term potential for releasing antibiotic into human bones is not well known. Five patients with chronic osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA) infection were effectively treated with local implantation of vancomycin-loaded hydroxyapatite blocks. Blocks were removed during the following reconstructive surgeries when the releasing capability of the blocks, and the bacteriocidal activity of the remaining vancomycin in these blocks could be evaluated. Vancomycin was rapidly released within 1 month after implantation, and by 3 months 90% of vancomycin had leaked from the blocks. At 18 months vancomycin still remained in a bacteriocidal form in the hydroxyapatite blocks, though the blocks had no releasing potential or the eluted vancomycin had been changed to a different form. Vancomycin-loaded porous hydroxyapatite blocks would be useful for the treatment of chronic osteomyelitis or implant-associated osteomyelitis due to MRSA.

Adult↗

PubMed2002

Systemic and mucosal immune responses in mice after rectal and vaginal immunization with HIV-DNA vaccine.

We examined the feasibility of inducing local and systemic human immunodeficiency virus (HIV)-specific immune responses by rectal and vaginal application of an HIV-DNA vaccine. Mice were immunized with an HIV-DNA vaccine preparation via a rectal or vaginal route. After several applications, HIV-specific antibodies were detected in sera, fecal extract solutions, and vaginal washes, and these antibodies were potent in inhibiting the syncytium formation of a CD4-positive human T cell line by a cell line capable of inducing HIV-1 infection. Spleen cells from rectally and vaginally immunized mice showed antigen-mediated IFN-gamma-inducing activity. In addition, with rectal immunization, mononuclear cells from both the spleen and the regional lymph nodes of the rectal region were found to be potent at inducing a cytotoxic T lymphocyte response. These humoral and cell-mediated immune responses were enhanced by augmenting the vaccine with granulocyte-macrophage colony-stimulating factor-expressing plasmids or IL-12-expressing plasmid. Our results demonstrated that both rectal and vaginal immunization could induce systemic and mucosal immunity and that these responses were enhanced by the addition of the above cytokine-expressing plasmids.

AIDS Vaccines↗

PubMed2002

Gene marking in adeno-associated virus vector infected periosteum derived cells for cartilage repair.

OBJECTIVE: To evaluate both the potential for transferring genes to periosteal cells using an adeno-associated virus (AAV) vector and the potential for gene expression after transplantation of those cells to a cartilage defect in vivo. METHODS: Periosteum was obtained from the tibia of 6-week-old rabbits and enzymatically digested. The isolated periosteum derived cells were cultured and the subconfluence cells were infected with a recombinant AAV expressing the LacZ gene (AAV-LacZ). Collagen gel containing the LacZ transferred, periosteum derived cells was transplanted into a full thickness articular cartilage defect in 10 rabbits. RESULTS: Infected cells still growing on the plate continued to express LacZ at least 12 weeks after AAV infection, with the highest percentage of LacZ positive cells reaching 74.4%. The LacZ positive cells were recognized at the transplant sites in 8 out of 10 knees. CONCLUSION: Gene expression in periosteum derived cells was sustained in vitro for at least 12 weeks using the AAV vector, and for 2 weeks ex vivo after transplantation into a cartilage defect.

Adenoviruses, Human↗