Is retrieval of bone material from multiorgan donors effective enough to cover demand for biostatic bone tissue grafts in Poland?

In Poland there is growing demand for biostatic allogeneic bone transplantation mostly for traumatologic operations and orthopedic reconstructions. The bone material is primarily harvested during postmortem examinations in forensic and pathology laboratories. Nevertheless, the collected amounts are not sufficient, so that material needs to be acquired from alternative sources, such as multiorgan donors. Between 1998 and 2003, 2331 potential donors were registered by the Transplantation Coordinating Center in Warsaw, which was adjusted to 1794 donors who would have been accepted as donors of the bone tissue. Unfortunately, due to denials from family members and public prosecutors, the sample was only 1416 donors, which would cover about 40% of the clinical orthopedic demand in Poland.

Factors determining the contamination of bone tissue procured from cadaveric and multiorgan donors.

There is an increasing demand for bone allografts that are widely used in orthopedic reconstructive procedures. The bone tissue may be harvested from two sources: cadavers and multiorgan donors. Providing safe and valuable bone allografts is of paramount importance. Contamination of allografts during bone retrieval seems to be one of the most important problems since pathogenic microorganisms might be responsible for postoperative infections and complications in the healing process. The purpose of our study was to identify all factors contributing to bacteriological contamination of harvested bones. Therefore, we have considered factors such as harvesting environment, explantation techniques, storage and preparation of allografts, number of preceding procurements from the same donor, procurement duration, and time interval between death and tissue procurement. The microbiological evaluation of allografts has been performed by taking cultures from all collected bones. Our study revealed significantly greater contamination rates of bone allografts harvested from morgue than from multiorgan donors. According to this observation, we suggest that orthopedic surgeons should pay particular attention to obtain more bones of the highest quality, personally participating in multiorgan procurements.

Differences in the kinetics of the mineralization process in endochondral and intramembranous osteogenesis in human fetal development.

About 300 samples of bone tissue from femoral diaphyses and from parietal bones of calvaria were collected from human fetuses aged from 6-8 to 40-41 weeks in order to compare the kinetics of the mineralization process in endochondral and intramembranous bone formation. The crystallinity of bone mineral was evaluated by the method based on electron spin resonance (ESR) spectrometry, and mineral content was measured after ashing of the samples. Highly significant differences in the kinetics of deposition of mineral (ash content) and maturation of deposited mineral (crystallinity coefficient) were found between parietal bones and femoral diaphyses in the course of fetal development. In the early stages of development (6-8 to 10-12 weeks), the content of mineral and its crystallinity in parietal bones were significantly lower than in femoral diaphyses. In the parietal bones a gradual increase in both values was observed until they reached a plateau at the age of 30 weeks. On the other hand, in femoral diaphyses of 6-8-week-old fetuses mineral content was high and deposited mineral showed a high degree of crystallinity. Both these values did not change significantly until birth. The differences in kinetics of the mineralization process between the weight-bearing bones and bones that are not exposed to the influence of strong external forces are most probably genetically conditioned. The collected data supply embryological information and might be used in the future for evaluation of pathologic changes in skeletal development.

Alteration of mineral crystallinity and collagen cross-linking of bones in osteopetrotic toothless (tl/tl) rats and their improvement after treatment with colony stimulating factor-1.

A common feature of various types of mammalian osteopetroses is a marked increase in bone mass accompanied by spontaneous bone fractures. The toothless (tl/tl) rat osteopetrotic mutation is characterized by drastically reduced bone resorption due to a profound deficiency of osteoclasts and their precursors. An altered bone morphology has also been observed. The mutants cannot be cured by bone marrow transplantation, but skeletal defects are greatly reduced after treatment with colony stimulating factor 1 (CSF-1). The objectives of this study were to characterize mineral and collagen matrices in cancellous and compact bone isolated from long bones of 6-week-old normal littermates, tl/tl osteopetrotic mutants and mutants (tl/tl) treated with CSF-1. There were no differences in bone mineral content, but a significant decrease in the crystallinity of mineral evaluated by the method based on electron paramagnetic resonance spectrometry was observed in all bones of tl/tl mutants as compared to that of controls. Within the collagen matrix, slight decreases in the labile cross-links, but significant increases in the content of the stable cross-links, pyridinoline, and deoxypyridinoline, were observed in both cancellous and compact bone of osteopetrotic mutants. In tl/tl mutants treated with human recombinant CSF-1, the normalization of the crystallinity of bone mineral as well as collagen cross-links was found. Our results indicate that remodeling of bone matrix in tl/tl mutants is highly suppressed, but that after treatment with CSF-1, this activity recovers significantly. Taken together, these data provide further support for the hypothesis that CSF-1 is an essential factor for normal osteoclast differentiation and bone remodelling.

Induction of heterotopic bone marrow formation in osteopetrotic rats by allogeneic decalcified bone matrix.

Contrary to theoretical expectations in osteopetrotic mutants heterotopic bone marrow formation was closely associated with osteogenesis, what is not observed in the orthotopic skeletal bones in these animals.

Heterotopically induced osteogenesis in osteopetrotic rat mutants. A preliminary report.

Heterotopic osteogenesis was induced in three groups of Fatty Orl-op strain of rats, i.e., osteopetrotic (op/op) mutants, op/op mutants cured by previous transplants of normal bone marrow, and phenotypically normal littermates. Allogenic decalcified bone matrix was used as inductor. The osteopetrotic mutants from heterotopic ossicles containing bone and bone marrow under the influence of inductor. After four weeks the signs of remodelling processes of induced bone tissue are observed: osteoclasts are found in the Howship lacunae, and bone marrow is formed in the spaces adjacent to the bone trabeculae. The induced bone marrow contains megakaryocytes, cells of the erythropoietic and granulopoietic lines as well as some infiltrating lymphocytes. The important finding is that the amount and the histological structure of bone tissue and bone marrow induced heterotopically in the osteopetrotic animals were similar to that observed in both control groups. It is concluded that 1) osteopetrotic mutants have the same potency to form heterotopic bone tissue under the influence of inductor as the control animals, and 2) remodelling processes in four-week-old, induced ossicles are normal and differ in this respect from defective rebuilding of the orthotopic bones of op/op hosts.

Amnion allografts prepared in the Central Tissue Bank in Warsaw.

Applications of allogenic amnion grafts range from wound dressing of severe burns, dermabrasions and lower extremity ulcer treatments to plastic surgery, laryngology and ophthalmology. The aim of the present study was to elaborate the method of processing, preservation and sterilization of human amnion allografts prepared as wound dressing used mainly for burned patients. During the amniotic sac processing (after separation of chorion) special attention was paid to ensure that the epithelial side of amnion is placed directly on polyester net used as a support. After application on the wound, the epithelial side with the basement membrane is facing outwards; this will promote migration, attachment and spreading of the host cells encouraging epithelialization. Human amnion allografts were preserved by lyophilization or deep-freezing and subsequently radiation-sterilized with a dose of 35 kGy. It has been observed, however, that lyophilized irradiated allografts are resorbed within a few days, while frozen irradiated ones better adhere to wound and persist even 3 weeks after grafting, therefore, it has been decided to preserve amnion by deep-freezing. Since the beginning of 1998 over 400 preserved radiation-sterilized amnion allografts (with a total surface area over 40,000 cm2) have been prepared at the Central Tissue Bank in Warsaw and distributed to clinics and hospitals throughout the country.

Applications of EPR spectroscopy to radiation treated materials in medicine, dosimetry, and agriculture.

Survey is given of the EPR studies on irradiated bone mineral referred to transplantology, physiology, pathology, dosimetry and to the detection of irradiated food. Stability, dose-dependency and nature of radiation-induced EPR signal in bone mineral (hydroxyapatite) are discussed. Paramagnetic centers produced by radiation as "labels" as applied to biomedical experiments and dosimetry are evaluated. Results on the detection of irradiated fruits, vegetables, and other dry food products are presented.

Bone powder exposed to the action of 12C and 25Mg ion beams as investigated by electron paramagnetic resonance spectroscopy.

Bovine compact bone powder was irradiated with alpha-particles of 241Am, 12C6+ and 35Mg12+ ion beams, then examined by the e.p.r. spectroscopy. The stable e.p.r. signal found is of the same characteristic as that observed in gamma-irradiated bone (g perpendicular = 2.0017, g parallel = 1.9973, delta Hpp = 0.85 mT). Thus, the structure of radiation induced paramagnetic center in bone does not depend on the LET of radiation used. The radiolytic yields of the formation of stable paramagnetic centres in bone powder irradiated with gamma-rays are G gamma = 0.08 +/- 0.01 while with 12C6+ ion beams roughly about Gc = 0.02, respectively.

Early and transient osteopetrosis in microphthalmic MIB-rats.

Microphtalmic blanc mutation (mib/mib) displays a very mild form of osteopetrosis in rats. The autosomal recessive mib mutation shows pleiotropic expressions in homozygotes. Microphtalmia, absence of eye and skin pigmentation, retardation in the tooth eruption were observed in the mutants. Most bone abnormalities occurred in newborns. An increased radiological opacity of long bones, persistence of primitive bone in medullary cavities, reduced number of poorly differentiated osteoclasts in mandibulae, reduced number of mononuclear peritoneal cells as well as reduced number of mononuclear osteoclast precursors in peritoneal cell population were found. In 3 weeks old and in adult mutants, both bone structure and the number of mandible osteoclasts appear normal, but the number of blood monocytes, peritoneal cells and mononuclear osteoclast precursors in peritoneal cell population remain significantly lower than in the healthy littermates. These observations indicate that the early failure of osteoclast differentiation and maturation is transient in the mib/mib form of osteopetrosis.

Optical diffractometry in bone research.

NASA: A new method of quantitative evaluation and comparison for bone tissue histological studies is described. Optical diffractometry allows numerical evaluation of dimensions of structures being studied and also permits study by discriminant analysis.^ieng