Bone infection: a clinical priority for clinicians, scientists and educators.

Bone infection has received increasing attention in recent years as one of the main outstanding clinical problems in orthopaedic-trauma surgery that has not been successfully addressed. In fact, infection may develop across a spectrum of patient types regardless of the level of perioperative management, including antibiotic prophylaxis. Some of the main unknown factors that may be involved, and the main targets for future intervention, include more accurate and less invasive diagnostic options, more thorough and accurate debridement protocols, and more potent and targeted antimicrobials. The underlying biology dominates the clinical management of bone infections, with features such as biofilm formation, osteolysis and vascularisation being particularly influential. Based on the persistence of this problem, an improved understanding of the basic biology is deemed necessary to enable innovation in the field. Furthermore, from the clinical side, better evidence, documentation and outreach will be required to translate these innovations to the patient. This review presents the findings and progress of the AO Trauma Clinical Priority Program on the topic of bone infection.

Fractionated radiation exposure amplifies the radioresistant nature of prostate cancer cells.

The risk of recurrence following radiation therapy remains high for a significant number of prostate cancer patients. The development of in vitro isogenic models of radioresistance through exposure to fractionated radiation is an increasingly used approach to investigate the mechanisms of radioresistance in cancer cells and help guide improvements in radiotherapy standards. We treated 22Rv1 prostate cancer cells with fractionated 2 Gy radiation to a cumulative total dose of 60 Gy. This process selected for 22Rv1-cells with increased clonogenic survival following subsequent radiation exposure but increased sensitivity to Docetaxel. This RR-22Rv1 cell line was enriched in S-phase cells, less susceptible to DNA damage, radiation-induced apoptosis and acquired enhanced migration potential, when compared to wild type and aged matched control 22Rv1 cells. The selection of radioresistant cancer cells during fractionated radiation therapy may have implications in the development and administration of future targeted therapy in conjunction with radiation therapy.

Unusually high levels of non-saponifiable lipids in the fishes escolar and rudderfish identification by gas and thin-layer chromatography.

Analysis of the non-saponifiable lipids of the fishes Lepidocybium flavobrunneum and Ruvettus pretiosus (escolar), and Centrolophus niger and Tubbia spp. (rudderfish) was performed. The analyses were used to clarify the cause of recent reports of illness (diarrhoea) in Australia from consumption of purported rudderfish. Both escolar and rudderfish contained very high levels of oil (generally between 14 to 25%, as % wet mass) in the fillet and the oil compositions were different to most seafood. Escolar oil contained mainly wax ester (>90% of oil). The oil from five specimens of rudderfish contained mainly diacylglyceryl ether (DAGE, >80% of oil) or hydrocarbon (>80% of oil, predominately squalene). One rudderfish specimen contained mainly polar lipid. Major differences in oil content and composition, including fatty alcohol and glyceryl ether diols (derived from DAGE), were observed between purported individuals of the same species or related species of rudderfish, raising the possibility of geographic or seasonal differences affecting the oil composition. The oil composition of fish fillet samples associated with the health issues were consistent with the profiles for escolar, rather than rudderfish species. These findings, in particular the lipid class and fatty alcohol profiles, were supported by general protein fingerprinting results and were consistent with the samples originating from individuals of the escolar species L. flavobrunneum. The high wax ester content of the escolar group clarifies the reported diarrhoeal effects to consumers. Purgative properties of high wax ester containing fish oils have been reported for escolar and other species. The results highlight the potential for non-saponifiable lipid profiles to be used for identification of fish fillets and oils to at least group level.

Identification of a 42-kDa plant mitochondrial outer membrane protein, MOM42, involved in the import of precursor proteins into plant mitochondria.

A 42-kDa plant outer mitochondrial membrane protein, MOM42, has been identified as an essential component of the plant mitochondrial precursor protein translocation apparatus. Immunological cross-reactivity has been detected between antibodies raised against both Neurospora and yeast mitochondrial outer membrane proteins and plant mitochondrial outer membrane proteins. Immunocompetition studies showed that import of precursors to Rieske FeS protein, ATPase su9-DHFR, and the adenine nucleotide transporter was inhibited in the presence of antibody to MOM42. The inhibition of Rieske Fes and su9-DHFR import was greater than that of the adenine nucleotide transporter. The competition studies suggest that the MOM42 is involved in the translocation of bound precursor proteins. The import data and the Western blots suggest that components of the mitochondrial import system are highly conserved.

Infection control and bone marrow transplantation.

BACKGROUND: Bone marrow transplantation for the treatment of malignancies is on the increase. Unfortunately, there are no well-validated infection control guidelines for this highly susceptible population. METHODS: Literature was reviewed concerning infection risks and interventions to decrease risks for bone marrow transplant recipients. RESULTS: Definitive information was generally lacking. However, basic "common sense" infection control recommendations for bone marrow transplantation were made in the following areas: air ventilation systems, design issues, environmental services, patient care issues, barrier precautions, nosocomial surveillance, and discharge planning. Recommendations must be tailored to each facility or setting. CONCLUSION: We conclude that validation of many of these recommendations is necessary to provide optimum care for bone marrow transplant recipients.

Timing of strangulation in adult hernias.

This retrospective study aimed to determine why the incidence of strangulated hernias in adults remains high. Seventy-nine patients presented with clinical evidence of hernia strangulation which required urgent surgery during the period 1979-87. Forty-six patients (58 per cent) had noted a hernia present for at least 1 month before strangulation: 18 (23 per cent) had not reported it to their family doctor, 19 (24 per cent) were known by family practitioners or non-surgical medical personnel to have a hernia but had not been referred for surgical opinion, and nine (11 per cent) had been previously assessed surgically with a view to elective repair. Of these nine, five were considered unfit, three were on waiting lists for operation and one had refused surgery. Thirty-two patients (40 per cent) presented primarily with strangulation within days of developing a hernia. The duration of hernia before strangulation in one patient was unknown. Although an unavoidable number of patients will continue to present with strangulation within days of developing a hernia, the overall incidence could be significantly reduced by greater public awareness of the risks of hernia strangulation and by a policy of immediate patient referral and prompt elective repair.

The effect of vasopressin and hepatic artery ligation on the blood supply to normal and metastatic liver tissue.

The effect of low (0.08 microU g-1 body wt min-1) and high (0.16 microU g-1 body wt min-1) rates of vasopressin infusion on blood flow to normal liver tissue and to liver metastases derived from azoxymethane induced colorectal carcinomas was studied in 36 male Wistar rats. Portal venous flow was measured by electromagnetic flowmetry and blood flow to normal and metastatic liver tissue by the clearance of xenon-133 injected directly into the liver parenchyma or metastasis. The low rate of vasopressin infusion decreased portal venous flow but increased blood flow to normal and metastatic liver tissue while at the higher rate of infusion these effects were reversed. Hepatic artery ligation (HAL) immediately following a low rate of vasopressin infusion abolished the observed increase in blood flow to both normal liver tissue and metastases. HAL immediately following the higher rate of vasopressin infusion further reduced blood flow to metastases but did not further alter blood flow to normal liver tissue. HAL prior to the infusion of the vasoactive drug significantly reduced blood flow to metastatic liver tissue, increased portal venous flow and was without effect on blood flow to normal liver tissue. Following HAL, blood flow to metastatic liver tissue was not further altered by either the low or high rates of vasopressin infusion. However, blood flow to normal liver tissue after HAL was reduced by a low rate of infusion of vasopressin and increased by the higher rate of infusion. The results of this study indicate that blood flow to normal or metastatic liver tissue can be increased or decreased by differential rates of infusion of vasopressin. These observations may have important implications in the treatment of liver metastases in man where different rates of vasopressin infusion may potentiate the effects of hepatic artery ligation or cytotoxic therapy.

Portal scanning for liver metastases in colorectal carcinoma.

In a prospective study over 2 years, 14 patients suffering from colorectal cancer had radionuclide liver scans performed via the portal route. Technetium-99m-labelled macro-aggregates of human serum albumen were injected via the cannulated umbilical vein, distributed through the portal system of the liver and their presence recorded by a gamma camera. Of 11 patients with clinically normal livers and no metastases found at laparotomy, five had abnormal portal scans, two of these dying from multiple liver metastases during follow-up. None of the patients with normal portal scans died with liver metastases within the 2-year study period.