Biomedical subjects

Dale Baker

Publications and source records attributed to Dale Baker.

4 recordsLinked to original sources

PubMed2006

Impaction grafting for femoral component revision using a non-polished bead-blasted chrome cobalt stem-average 8 1/2-year follow-up.

Impaction grafting for femoral component revision in patients with significant bone loss has been reported using a tapered polished femoral component that is meant to subside. This study reports our results of femoral component revision using impaction grafting with a bead-blasted chrome cobalt stem designed not to subside. Forty-eight femoral component revisions using impaction grafting were retrospectively reviewed with a minimum 6 1/2-year follow-up. There were 2 failures due to aseptic loosening of the femoral component (4%). There were 22 total complications, and the overall failure rate was 21%. Impaction grafting for femoral component revision using a bead-blasted chrome cobalt stem in patients with a large femoral canal diameter has shown good results with respect to aseptic loosening with minimal subsidence.

Adult↗

PubMed2004

Femoral component revision using an extensively hydroxyapatite-coated stem.

Femoral component revisions with extensively coated stems have shown promising clinical results, although concerns over stress shielding still exist. We retrospectively reviewed 59 patients undergoing femoral component revision with an extensively hydroxyapatite (HA)-coated stem. The average length of follow-up was 3.3 years (range, 2-5 years). The average preoperative Harris Hip Score was 43 points, which improved to 86 points at the latest follow-up (P < .01). The overall mechanical failure rate was 2%. No evidence of stress shielding was seen in 78% of patients. The clinical results of this series using an extensively HA-coated stem are similar to those using an extensively porous-coated stem. Long-term follow-up is required to determine if an extensively HA-coated implant will be superior to an extensively porous-coated implant with regard to stress shielding.

Aged↗

PubMed2003

Intravenous mouse infection model for studying the pathology of Enterococcus faecalis infections.

An intravenous mouse infection model was used to compare the virulence of Enterococcus faecalis strains, to study bacterial localization and organ histopathology, and to examine the effects of Nramp1 and gamma interferon (IFN-gamma) on the course of infection. Infection of BALB/c mice with 5 x 10(8) CFU of E. faecalis JH2-2, MGH-2, 418, DS16C2, or OG1X revealed the following virulence ranking (from highest to lowest): MGH-2, 418, DS16C2, JH2-2, and OG1X. Discernible differences in the number of MGH-2 and JH2-2 bacteria were observed at 7 days (168 h) in the blood (P = 0.037), at 72 h in the liver (P = 0.002), and at 8 h in the spleen (P = 0.036). At these time points, the number of MGH-2 bacteria was higher in the blood and liver while the number of JH2-2 bacteria was higher in the spleen. At 72 h, livers from MGH-2-infected mice had higher numbers of coalescing aggregates of leukocytes and a greater degree of caseous necrosis than those from JH2-2-infected mice. These results indicate a correlation between the virulence of the E. faecalis strain, the number of bacteria in the liver, and the degree of histopathology of the liver at 72 h postinfection. IFN-gamma was important in E. faecalis infection, since IFN-gamma gene knockout mice had reduced mortality and massive coagulative necrosis was observed in wild-type mice. The contribution of Nramp1 was unclear, since Nramp1(-/-) mice and the respective control mice were innately resistant to E. faecalis. The mortality of mice in this model is probably due to induction of cytokine release and massive coagulative necrosis.

Animals↗

PubMed2002

Experimental infection of horses with West Nile virus.

A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt antibody titers >1:10 between days 7 and 11 post infection. The highest viremia level in horses fed upon by the recipient mosquitoes was approximately 460 Vero cell PFU/mL. All mosquitoes that fed upon viremic horses were negative for the virus. Horses infected with the NY99 strain of WNV develop low viremia levels of short duration; therefore, infected horses are unlikely to serve as important amplifying hosts for WNV in nature.

Aedes↗