Dual antibiotic loaded bone cement in patients at high infection risks in arthroplasty: Rationale of use for prophylaxis and scientific evidence

In view of the demographic changes and projected increase of arthroplasty procedures worldwide, the number of prosthetic joint infection cases will naturally grow. Therefore, in order to counteract this trend more rigid rules and a stricter implementation of effective preventive strategies is of highest importance. In the absence of a "miracle weapon" priorities should lie in evidence-based measures including preoperative optimization of patients at higher infection risks, the fulfilment of strict hygiene rules in the operating theatre and an effective antibiotic prophylaxis regimen. Instead of a "one size fits all" philosophy, it has been proposed to adjust the antibiotic prophylaxis protocol to major infection risks taking into account important patient-and procedure-related risk factors. A stronger focus on the local application mode via use of high dose dual antibioticloaded bone cement in such risk situations may have its advantages and is easy to apply in the theatre. The more potent antimicrobial growth inhibition in vitro and the strong reduction of the prosthetic joint infection rate in risk for infection patients with aid of dual antibiotic-loaded bone cement in clinical studies align with this hypothesis.     

Astroblastoma: clinicopathologic features and chromosomal abnormalities defined by comparative genomic hybridization

Astroblastomas are uncommon brain tumors whose classification and histogenesis have been debated. Precise criteria for diagnosis have been described only recently, but have not found wide acceptance. We report the clinical, radiographic, and histopathologic features of 20 astroblastomas, and the chromosomal alterations in seven cases as detected by comparative genomic hybridization (CGH). The tumors occurred both in children and young adults (average age, 14 years), most often as well circumscribed, peripheral, cerebral hemispheric masses. Radiographically, the lesions were contrast-enhancing and solid, often with a cystic component. All were characterized histologically by astroblastic pseudorosettes, and most displayed prominent perivascular hyalinization, regional hyaline changes, and pushing borders in regard to adjacent brain. Tumor cells were strongly immunoreactive for S-100 protein, GFAP, and vimentin. Staining for EMA was focal. Ten of 20 astroblastomas were classified as "well differentiated" and 10 were classified as "malignant," largely on the basis of hypercellular zones with increased mitotic indices, vascular proliferation, and necrosis with pseudopalisading. All 10 well differentiated lesions and 8 of 10 malignant lesions were completely resected. None of the well differentiated astroblastomas recurred within the limited follow-up period. Three malignant astroblastomas recurred, including two incompletely resected tumors, and one that had been totally resected. One patient died of disease following recurrence. The most frequent chromosomal alterations detected by CGH were gains of chromosome arm 20q (4/7 tumors) and chromosome 19 (3/7). The combination of these gains occurred in three, including two well differentiated and one malignant astroblastoma. Other alterations noted in two tumors each were losses on 9q, 10, and X. These chromosomal alterations are not typical of ependymoma or infiltrating astrocytic neoplasms, and suggest that astroblastomas may have a characteristic cytogenetic profile in addition to their distinctive clinical, radiographic, and histopathologic features.     

Corporate buying of health care plans: a framework for marketing theory and practice

Much of the research in health care plan and provider selection has focused on the patient's selection process. The authors report on the increasing need to understand the corporation's decision process in selecting health care plans and providers. Managed care marketers need to understand this process in order to design and market such plans successfully.     

Clinical and pathological analysis of spinal cord astrocytomas in children

Twelve children with pathologically confirmed, well-differentiated spinal cord astrocytomas were studied, and correlations among the degree of resection, pathological characteristics, and time of recurrence were examined. Eight tumors were sampled for biopsy or subtotally resected, and 4 were thought to have been totally removed. Clinical recurrence was seen in 4 of 12 patients, 2 of whom died of their disease. The time to recurrence was 1, 2, 2, and 35 years, respectively. The other 8 children remain free of symptoms, with follow-up ranging from 6 months to 35 years (mean, 8.8 years). In 3 of 8 patients who underwent biopsy or subtotal resection, the tumor recurred, and 2 patients died, whereas there was one recurrence in the patients in whom a "total" resection had been obtained. The histologically well-differentiated nature of the lesions correlated well with the relatively prolonged clinical course seen in this series during the period of observation. The relatively long clinical courses seen in our limited series should be considered before high-risk therapy for spinal cord astrocytomas in children is implemented. The presence of four pilocytic astrocytomas in this group was of special interest, and it seems likely that these discrete neoplasms can be distinguished from the more infiltrating fibrillary astrocytic neoplasms by magnetic resonance imaging with enhancement with gadopentetate dimeglumine.     

Lack of demonstratable effects of pollutants on cyt b sequences in wood ducks from a contaminated nuclear reactor cooling pond.

The effects of low levels of radiation on DNA mutation rates are largely unknown for free-living vertebrates. In this study we investigated the effects of contamination from cooling ponds at a nuclear production facility in South Carolina on the mutation rates in mitochondrial DNA in wood ducks (Aix sponsa). Specifically, we sequenced a 433-bp portion of the cytochrome b gene from 18 female-offspring pairs of wood ducks from contaminated ponds and 2 female-offspring pairs from control ponds. Very low haplotype diversity was observed overall, and no case of mutation between female and offspring could be satisfactorily documented. This suggests that the levels of radioactive contamination in these cooling ponds have little effect on the mutation rate of mitochondrial DNA in these waterfowl and that mitochondrial DNA may not be as sensitive an indicator as previously anticipated.     

Treatment of complete acromioclavicular dislocation: present indications and surgical technique with biodegradable cords

We report a retrospective study of 48 patients with complete acromioclavicular dislocation (Tossy III). All patients (38 male; 10 female) with an average age of 33.4 years underwent surgery including PDS-augmentation. More than half of the injuries were caused by sport accidents. There were no complications during surgery. 87% of the patients were free of complaints and subjectively very satisfied with the surgical results. By radiological examination we diagnosed a subluxation of the clavicula in 25% of the cases and arthrosis in 17% of the cases. Assessment of subjective complaints, the clinical examination, and the radiological diagnostic according to the Taft Score (0-12 points) resulted in an average value of 10.2 points. The surgical intervention using PDS-cord augmentation in cases of complete acromioclavicular separation is a safe and economic method with a low complication rate. Advantages are possible early-functional treatment, no risk of movement of implants, and avoidance of metal removal.     

Glycolipid markers of astrocytomas and oligodendrogliomas

Neutral glycolipids and gangliosides were analyzed in 149 astrocytomas (A), 46 oligodendrogliomas (O), and 21 oligoastrocytomas (OA) to determine if specific glycolipids correlate with histologic diagnosis and grade. Positivity for asialoGM1 (GA1) and negativity for paragloboside by immuno-TLC correlated with histological diagnosis of O and OA, whereas the reverse pattern correlated with A. High levels (over 5 microg hexose per mg dry weight) of CMH generally correlated with an O component, but the association was not as strong as for either GA1 presence or paragloboside absence. Pilocytic astrocytomas and pleomorphic xanthoastrocytomas had high proportions (> 15%) of globoside, low ratios (< 0.5) of GD1a: GD1b, and identifiable ceramide trihexoside (CTH). Three gangliosides of the 1b pathway were progressively lost with increasing grade of A, but a similar correlation with grade was not seen in O or OA. A high proportion of cases expressing sialosylparagloboside (3'LM1; 6'LM1) were grade 4 A. Glycolipids are synthesized by glycosyltransferases that add specific sugars to the nascent oligosaccharide. Correlation of specific glycolipids with histological diagnoses and grades indicate that these tumor types express specific patterns of glycosyltransferases, several of which have been cloned. It is possible that critical genes coding for these enzymes are deleted, overexpressed, or mutated in certain tumor types and grades, thus leading to the patterns of glycolipids that we found to be associated with these tumors.     

Identification of differentially expressed genes in breast cancer

A number of genes differentially expressed in breast cancer were isolated using a subtractive cloning technique. DNA sequence analysis and GenBank searches of T4F10, T2H7, and T2E5 cDNA clones found them to be identical with E2A, MSS1, and SEC13R genes. Their expression in a variety of primary breast tumor and cancer cell lines was compared with c-ERB-B2 and pS2 by Northern blot analysis. In breast cancer cell lines, the genes that we isolated are more frequently expressed than the previously described c-ERB-B2 and pS2.