The effect of radiation on the fracture repair process. A biomechanical evaluation of a closed fracture in a rat model

The effects of a single dose of irradiation on the biomechanical parameters of the fracture healing process were studied in a rat model. Intramedullary pinning was performed before production of a closed femoral midshaft fracture. The experimental group was exposed to 900 rad 3 days after fracture and was compared with a control group with a similar fracture that received no irradiation. Animals were killed at intervals ranging from 2-16 weeks after surgery and the bones were tested until failure in torsion. In the irradiated groups, a delay of 4 weeks was noted in the biomechanical parameters associated with fracture healing (torque to failure, torsional stiffness, angle to failure, and biomechanical stage). Despite this delay in the normal temporal progression, the staging and stiffness approached normal controls within an 8-week period. However, the torque to failure remained below normal levels at the conclusion of this study. These results differ from a previous study using an open fracture model.     

Long-term maintenance of hematopoietic stem cells does not require contact with embryo-derived stromal cells in cocultures

We recently established that two midgestation-derived stromal clones--UG26-1B6, urogenital ridge-derived, and EL08-1D2, embryonic liver-derived--support the maintenance of murine adult bone marrow and human cord blood hematopoietic repopulating stem cells (HSCs). In this study, we investigate whether direct HSC-stroma contact is required for this stem cell maintenance. Adult bone marrow ckit+ Ly-6C- side population (K6-SP) cells and stromal cells were cocultured under contact or noncontact conditions. These experiments showed that HSCs were maintained for at least 4 weeks in culture and that direct contact between HSCs and stromal cells was not required. To find out which factors might be involved in HSC maintenance, we compared the gene expression profile of EL08-1D2 and UG26-1B6 with four HSC-nonsupportive clones. We found that EL08-1D2 and UG26-1B6 both expressed 21 genes at a higher level, including the putative secreted factors fibroblast growth factor-7, insulin-like growth factor-binding proteins 3 and 4, pleiotrophin, pentaxin-related, and thrombospondin 2, whereas 11 genes, including GPX-3 and HSP27, were expressed at a lower level. In summary, we show for the first time long-term maintenance of adult bone marrow HSCs in stroma noncontact cultures and identify some secreted molecules that may be involved in this support.     

Sequelae of lateral ovarian transposition in irradiated cervical cancer patients

Lateral ovarian transposition (LOT) is a useful technique for preserving ovarian function in "high-risk" premenopausal Stage I cervix cancer patients who undergo hysterectomy and subsequent postoperative whole pelvic radiation therapy. From 1978 to 1988, 38 FIGO Stage I cervical cancer patients underwent LOT as part of their initial operative procedure and 14 of these patients (37%) subsequently received pelvic radiation therapy (LOT + RT) because of pathological findings such as metastatic pelvic lymph node involvement or positive surgical margins (13 patients) or recurrent disease (1 patient). Ten (71%) of the 14 (LOT + RT) patients have maintained ovarian function with a median follow-up of 35 months. Preservation of ovarian function was directly related to the estimated scatter dose to the ovaries. For patients whose estimated ovarian dose was 300 cGy or less, only 1 of 9 patients (11%) underwent menopause, whereas 3 of 5 patients (60%) became menopausal if the ovarian dose was more than 300 cGy. The placement of the ovaries was also crucial for preservation of ovarian function, with 100% of the patients developing menopause if the ovaries were placed below the iliac crest. A major side effect of LOT was the development of symptomatic ovarian cysts in 7 (18%) of the 38 Stage I patients who underwent LOT. In the 24 patients who underwent LOT alone without RT, the incidence of symptomatic ovarian cysts was 25% compared to only 7% of the patients who underwent LOT + RT, although this difference was not statistically significant (p = .18).     

Wound ballistic evaluation of the TASER® XREP ammunition

The Taser® eXtended Range Electronic Projectile (XREP®) is a wireless conducted electrical weapon (CEW) designed to incapacitate a person from a larger distance. The aim of this study was to analyze the ballistic injury potential of the XREP. Twenty rounds were fired from the Taser®X12 TM shotgun into ballistic soap covered with artificial skin and clothing at different shooting distances (1–25 m). One shot was fired at pig skin at a shooting distance of 10 m. The average projectile velocity was 67.0 m/s. The kinetic energy levels on impact varied from 28–52 J. Depending on the intermediate target, the projectiles penetrated up to 4.2 cm into the ballistic soap. On impact the nose assembly did not separate from the chassis, and no electrical activation was registered. Upon impact, a skin penetration of the XREP cannot be excluded. However, it is very unlikely at shooting distances of 10 m or more. Clothing and a high elasticity limit of the target body area can significantly reduce the penetration risk on impact.     

Molecular characterization of a recently identified circovirus in zebra finches (Taeniopygia guttata) associated with immunosuppression and opportunistic infections

A recently identified circovirus (family Circoviridae) was detected in 14 zebra finches (Taeniopygia guttata) from seven aviaries and hobbyist breeders using polymerase chain reaction followed by sequencing. Full genome sequences of virus strains from six zebra finches consistently revealed characteristic circoviral genomic features such as a stem-loop structure and two major open reading frames (ORFs) encoding the replication-associated protein and the putative capsid protein. One further ORF encoding a protein of unknown function was additionally identified in all six genomes. Based on full genome nucleotide comparison, zebra finch circovirus was most similar to Finch circovirus originating from a Gouldian finch (Chloebia gouldiae) sharing 78% nucleotide identity. High genetic diversity was detected in the circoviruses from individual zebra finches. Comparison of the six full genome sequences revealed two genetic subgroups, which shared pairwise nucleotide identities between 91.4% and 92.7%. Analyses including partial sequences of the replication-associated protein gene of the zebra finch circovirus strains from all 14 birds supported the existence of two main clusters. Clinical diseases associated with circovirus infection were found in nestlings, fledglings and adult birds and varied from mild to severe with high mortality caused by secondary infections. Macrorhabdus ornithogaster was the most frequently detected opportunistic pathogen. Feathering disorders were seen in two birds. Lymphocytic depletion of the spleen and leukocytopaenia were detected in individual birds, suggesting immunosuppression and a pathogenesis common to circovirus infections in other birds.     

Changes of the phenotype of erythroid progenitor cells (BFU-E, CFU-E) and their progenies during early steps of differentiation

Early differentiation processes of human erythroid progenitor cells (BFU-e, CFU-e) have been studied during in vitro proliferation using a panel of monoclonal antibodies with known reactivity on different levels of the erythroid cell line. Two antibodies recognizing structures on BFU-e (VIP-2b, BMA 021), two antibodies reactive with CFU-e and nucleated red cells (5F1, CLB-Ery-3) and one antibody directed against glycophorin A (VIE-G4) were used for this study. Normal human bone marrow cells were induced to proliferation in an erythroid progenitor cell assay and, after different periods of incubation, agar cultures were treated with these antibodies and complement. Thereafter, the remaining erythroid cells were incubated again to continue their proliferation with the same stimulators as before. The changes of the phenotype of BFU-e and CFU-e progenies during in vitro proliferation were determined by the reduction of colony formation in comparison with untreated control cultures. Our results indicate that the loss of HLA-DR antigens and the p45 structure is accompanied by the acquisition of structures recognized by the antibodies 5F1 and CLB-Ery-3. After 5-7 d of incubation BFU-e derived progenies exhibit the same antigenic structure as has been found for CFU-e. Glycophorin A expression could only be demonstrated at a late differentiation stage of the erythroid cell lineage.     

Zur Todesfeststellung beim MANV

Background

Current concepts for mass casualty incidents deal insufficiently with defining dead patients. This may lead to forensic problems and also to an insufficient use of available resources.

Method

Research and analysis of the current literature.

Results

It seems reasonable to develop a strategy to handle the situation of determining death in mass casualties, considering the tactical, medical and forensic priorities, with the goal of a more efficient and effective overall use of available resources. To act ethically and efficiently, the focus should be on the determination of the available resources and therefore options of treatment, whereas determination of death and legal inspection should be dealt with separately by specifically trained personnel, e.g. forensic pathologists.

Conclusions

The authors think that category IV is merely applicable. The main task of emergency services in such events is to identify, prioritize and treat critical patients. The determination of death is closely associated with legal inspections and should be organized on the level of the incident command.

     

Reversible HLA multimers (Streptamers) for the isolation of human cytotoxic T lymphocytes functionally active against tumor- and virus-derived antigens

The development of MHC/peptide multimers has facilitated the visualization and purification of antigen-specific T cells. However, the persistence of multimers leads to prolonged T cell receptor signaling and subsequently to altered T-cell function. We have recently developed a new type of MHC/peptide multimers, which can be dissociated from the T cell. Herein, we have generated and tested for the first time reversible HLA/peptide multimers, termed Streptamers, for the isolation of human T cells. The Streptamer technique demonstrates the specificity and sensitivity of conventional HLA/peptide tetramers with regards to the sorting of human T lymphocytes. This is shown for T cells directed against immunogenic peptides derived from viral and tumor-associated antigens. We show that antigen-specific cytotoxic T cells remain functionally active following Streptamer dissociation, whereas lytic function and proliferation of the T cells is impaired in the presence of conventional tetramers. These novel HLA/peptide Streptamer reagents allow the isolation of antigen-specific T cells with preserved function and, therefore, facilitate the development of adoptive T cell transfer regimens for the treatment of patients with cancer or infectious diseases.