Inactivation of viruses related to hepatitis C virus by pasteurization in human plasma derivatives

The survey of bone allograft transplantation in a Japanese regional bone bank

BACKGROUND

In reconstructive surgery for large bone defects, the demand for bone allografts has increased over the years; however, it is unclear how the supply and demand in Japanese regional bone banks have evolved over time. This study investigated the 15-year supply and demand of bone allografts stored in a regional bone bank, along with assessing the screening process's effectiveness.

METHODS

The target period was 15 years from April 2005 to March 2020. The period was subdivided into three 5-year periods: first, second, and third. The study items included the number of bone allografts donated, the number of bone allografts used, donor and user facilities, surgical methods using bone allografts, and the number of bone allografts discarded. We used the Cochran-Armitage test for statistical analysis.

RESULTS

A total of 1852 bone allografts were donated to the bone bank, and a total of 1721 were used. A total of 677 bone allografts grafts were provided in the first period, 738 in the second period, and 525 in the third period, indicating a decreasing trend. The average number of allografts per surgery was 2.8 in the first, 3.1 in the second, and 1.7 in the third, showing a decreasing trend. Concerning the percentage of each surgery using bone allografts, spine fusion decreased in the third period but not significantly, whereas primary hip arthroplasty increased significantly in the third period. The total number of discarded bone allografts was 4.8% of the total number of donated bone allografts, largely because of a lack of screening tests.

CONCLUSION

Although the number of allogeneic bone surgeries has been increasing over time, the number of allogeneic bone donations has shown a decreasing trend, and there is a need to develop a system that can provide surgeons with sufficient bone allografts.

The effect of bisphosphonate and intermittent human parathyroid hormone 1-34 treatments on cortical bone allografts in rabbits

AIM

This study compares the effect of bisphosphonate and intermittent PTH administration on haversian remodeling in cortical bone allografts in rabbits.

MATERIALS AND METHODS

An intercalary heat-treated cortical bone allograft was applied to a segment skeletal defect in the left femur of Japanese white rabbits. The rabbits were randomly assigned to one of three groups: the vehicle control group (CNT); the bisphosphonate group (B group); and the intermittent PTH treatment group (P group). Periodic radiographic evaluation was performed and peripheral quantitative computerized tomography (pQCT) was used to evaluate the total bone area (Area), bone mineral density (BMD), and bone mineral content (BMC). The allografts also underwent histological examination.

RESULTS

The P group was radiographically superior in the latter stage, compared with the other groups. pQCT analysis of the allografts showed that the B group had a significantly higher Area and BMC. These parameters in the latter stage were significantly lower in the P group than in the other groups. The allograft of the B group was histologically mostly necrotic bone, whereas allograft of the P group showed abundant newly formed bone.

CONCLUSION

In rabbits, bisphosphonate prevents resorption, but suppresses remodeling and incorporation; by contrast, PTH increases resorption and accelerates allograft remodeling and incorporation. Based on our preliminary data, we suggest that further research on the manner of administration of bisphosphonate and PTH - which have contrasting effects - can be beneficial in maintaining bone strength and in regulating remodeling and allograft incorporation.

The effect of heat-treated human bone morphogenetic protein on clinical implantation

For the clinical usage of human-derived bones, it is necessary to treat bones to reduce the risk of contamination by microorganisms. Bone morphogenetic protein is vulnerable to chemicals, but shows resistance to thermal heat to 70 degrees C in a short time. In this experiment, crude human bone morphogenetic protein was extracted from heat-treated bones at 60 degrees C for 10 hours and from nonheated bones. Sodium dodecyl sulfate polyacrylamide gel electrophoresis for these specimens was done. Gelatin capsules containing 5 mg of crude human bone morphogenetic protein extracted from heated and nonheated bones were implanted into thigh muscle pouches of five mice. At 20 days after implantation, the heterotopic bone formation was compared by evaluating the radiographic and histologic analyses. The sodium dodecyl sulfate polyacrylamide gel electrophoresis pattern of the human bone morphogenetic proteins showed five main bands (16, 22, 28, 35, and 67 kDa) that were almost identical. Heterotopic bone formation observed on the radiograph was induced by crude human bone morphogenetic protein from heated bones in a manner similar to that used for nonheated bones. The results from this study show that heat-treated bone preserves osteoinduction.

Transport of viruses through fetal membranes: an in vitro model of perinatal transmission

A model system for perinatal transmission of viral infections was developed and transport of infectious virus particles through fetal membranes was investigated. Viruses of different families known to cause serious intrauterine infections were selected, including relevant and model viruses: the DNA-viruses HSV-1 and -2 as well as the animal herpes viruses BHV-1 and SHV-1, the RNA-virus BVDV as a model for hepatitis C virus, HIV-1 and -2, and PPV as a model for parvovirus B19. Migration of infectious virus from the maternal to the fetal side of the membrane could be detected as early as 20 min after the start of incubation. A peak of virus migration was observed after 1-2 hr. 0.02-1% of HSV-1 and 0.03-0.2% of HSV-2 were transported from the maternal side of the membrane to the fetal side. Only 0.01% of PPV migrated to the fetal side, whereas no transport of BVDV was observed. HIV-1 (1.4%) and HIV-2 (0.8%) seemed to be transported at higher rates. The concept of an active transport of infectious virus is compatible with the kinetics of penetration of the fetal membrane. The question of whether different receptors for the individual viruses on the cellular surface account for differences in virus transport will require further investigation. The fetal membrane acts as a protective barrier for the fetus, reducing greatly infectious titers or even preventing completely penetration of virus.