Amphiphilic bonder improves adhesion at the acrylic bone cement–bone interface of cemented acetabular components in total hip arthroplasty: in vivo tests in an ovine model

INTRODUCTION: Even following the introduction of the "third generation" cementing technique, an improvement of the fixation of the acetabular component similar to that of the femoral has not been shown in clinical studies. The goal of the present study was to achieve a better stability with the use of an amphiphilic bonder while preserving the mechanically important subchondral sclerosis. MATERIALS AND METHODS: In a total of 20 sheep, a cemented total hip replacement was implanted. In the treatment group (n = 10), the implantation was carried out following surface conditioning of the acetabular bed with an amphiphilic bonder. All the sheep were followed for 9 months. To assess the biocompatibility, the osseous ingrowth at the cement-bone interface was depicted with the help of an in vivo fluorescent marking of the osteoblasts. Additionally, conventional radiographs were obtained over the course of treatment. Finally, the ovine pelvic regions were split following a standardized technique allowing for histological evaluation of the cement-bone interfaces. RESULTS: The acetabular components of the treatment group revealed a stable cement-bone compound. In the control group, the implants were easily dislodged from their beds. This finding was consistent with the radiological and histological results, which had revealed increased, progressive lytic radiolucent lines and the interposition of fibrous tissue at the cement-bone interface in the control group compared to the treatment group. The bonder was biocompatible. CONCLUSION: Following the application of the bonder, the cemented acetabular components revealed an improved stability without signs of inflammation or neoplasia in a viable acetabular osseous bed. With the help of this technique, the in vivo longevities of cemented acetabular components can be increased in the clinical setting without sacrificing the biomechanical relevant subchondral sclerosis.     

Hepatic fatty acid synthesis is suppressed in mice with fatty livers due to targeted apolipoprotein B38.9 mutation

Humans and genetically engineered mice with hypobetalipoproteinemia due to truncation-producing mutations of the apolipoprotein B (apoB) gene frequently have fatty livers, because the apoB defect impairs the capacity of livers to export triglycerides (TGs). We assessed the adaptation of hepatic lipid metabolism in our apoB-38.9-bearing mice. Hepatic TG contents were 2- and 4-fold higher in heterozygous and homozygous mice, respectively, compared with wild-type mice. Respective in vivo hepatic fatty acid synthetic rates were reduced to 40% and 15% of the wild-type rate. Hepatic mRNAs for sterol regulatory element-binding protein (SREBP)-1c, fatty acid synthase (FAS), and stearoyl coenzyme A desaturase-1 were coordinately decreased. FAS and SREBP-1c mRNA levels were strongly and positively correlated with each other and inversely correlated with hepatic TGs, suggesting that impaired TG export is a potent inhibitor of fatty acid synthesis. In contrast, levels of plasma beta-hydroxybutyrate and of hepatic carnitine palmitoyl transferase and peroxisome proliferator-activated receptor-alpha mRNAs were not altered, implying that beta-oxidation was not affected. Fasting followed by refeeding increased hepatic fatty acid synthesis 56-fold over fasting in normal and heterozygous mice but only 24-fold in homozygous mice. Parallel changes occurred in FAS and SREBP-1c mRNAs. Thus, impairment of very low density lipoprotein export downregulates hepatic fatty acid synthesis, but the adaptation is incomplete, resulting in fatty livers. The signals mediating suppression of FAS and SREBP-1c levels remain to be identified.     

Naturally occurring antibodies to an epitope on Plasmodium falciparum gametes detected by monoclonal antibody-based competitive enzyme-linked immunosorbent assay.

The antibody response to an epitope on gamete antigens of Plasmodium falciparum in persons naturally exposed to malaria has been investigated by competitive enzyme-linked immunosorbent assay. The assay detects antibodies to an epitope on the 48/45-kilodalton (kDa) gamete surface antigen by competition with horseradish peroxidase-labeled monoclonal antibody IIC5-B10. Five sera previously shown to immunoprecipitate the 230- and 48/45-kDa antigens significantly inhibited IIC5-B10 binding to an average of 24.2% of control. The one serum which precipitated only the 48/45-kDa antigen did not inhibit IIC5-B10 binding. For 26 sera which were negative by immunoprecipitation, mean binding in the assay was 112.7% of control (pooled London nonimmune sera). Recognition of both 230-kDa and 48/45-kDa antigens was associated with a titer of 1:9 or greater (reciprocal geometric mean titer, 27.6) for inhibition to more than 2 standard deviations from the mean of the negative sera. The results show that the IIC5-B10 binding site is a naturally immunogenic epitope recognized by the majority of persons who had antibodies to the 48/45-kDa protein. An additional finding was enhancement of binding of IIC5-B10 to an average of 154.4% of control by five sera which recognized only the 230-kDa antigen, presumably due to conformational alteration of the gamete antigen complex.     

Significance of incidental 18F-FDG accumulations in the gastrointestinal tract in PET/CT: correlation with endoscopic and histopathologic results.

This study was undertaken to identify the clinical value of incidentally detected lesions (IDLs) in the gastrointestinal tract (GIT) with (18)F-FDG PET/CT. METHODS: The reported database of 3,281 patients who underwent partial-body (18)F-FDG PET/CT scans from April 2001 to September 2003 was reviewed. Patients with incidental (18)F-FDG accumulations in the GIT that were associated with concomitant abnormal soft-tissue density or wall thickening on the native CT were evaluated. Incidental PET/CT findings were correlated with endoscopic and histopathologic results. RESULTS: According to our selection criteria, 98 (3%) of the 3,281 patients had an IDL of the GIT on (18)F-FDG PET/CT. Correlative endoscopic findings were available in 69 (70%) of 98 patients. Of these, 13 patients (19%) were harboring newly occurring cancers of the GIT in addition to preexisting aerodigestive tract tumors (n = 12) and malignant melanoma (n = 1). Twenty-nine (42%) patients were identified with precancerous lesions, such as advanced colonic adenomas (n = 27), Barrett's esophagus (n = 1), and intestinal metaplasia of the gastric mucosa (n = 1). Inflammatory and other benign GIT lesions were detected in 12 (17%) and 6 (8%) patients, respectively. In 9 (13%) patients, PET/CT was false-positive, showing normal findings in subsequent endoscopic examinations. In 20 (28%) of 69 patients, PET/CT findings had a relevant impact on the clinical management. Twenty-nine (30%) of the 98 patients were not subject to a further endoscopic examination because of the extent and nature of the primary tumor (n = 17), loss to follow-up (n = 7), death shortly after PET (n = 3), and patient unwillingness (n = 2). CONCLUSION: Although IDLs of the GIT on (18)F-FDG PET/CT scans are found only in about 3% of cases, they are associated with a substantial risk of an underlying cancerous or precancerous lesion. Early identification of these occult lesions may have a major impact on the patients' management and outcome.     

Magnetic resonance neurography of median neuropathies proximal to the carpal tunnel

This review provides magnetic resonance neurography (MRN) imaging appearances of median neuropathy proximal to the carpal tunnel. Carpal tunnel syndrome (CTS) and its imaging have been extensively described in the literature; however, there is a relative paucity of information on the MR imaging appearances of different pathologies of the median nerve proximal to the carpal tunnel.     

Gallstone recurrence after direct contact dissolution with methyltert-butyl ether

To determine the rate and characteristics of gallstone recurrence after direct contact dissolution with methyltert-butyl ether, 60 consecutive patients were followed for up to 4.5 years (median 2.2 years) after complete disappearance of all stone residues and debris and cessation of adjuvant bile acid therapy. Initial gallstones had been multiple in all but four patients. Twenty-eight of the 60 patients developed recurrent gallstones. The cumulative risk of gallstone recurrence (actuarial analysis) was 23±6%, 34±7%, 55±8%, and 70±9% at one, two, three, and four years, respectively. The recurrent stones were usually multiple and small (6±4 mm). Gallstone recurrence was associated with recurrent biliary pain in two patients, one of whom developed acute cholecystitis. Recurrent stones were cleared completely by bile acid medication with or without shock-wave lithotripsy in 61±15% of patients at one year (actuarial analysis). In conclusion, gallstone recurrence after successful contact dissolution of multiple stones with methyltert-butyl ether has to be expected in a high percentage of patients. Most patients, however, remain free of biliary pain during long-term follow-up.     

Comparison of microarray-based RNA expression with ELISA-based protein determination of HER2, uPA and PAI-1 in tumour tissue of patients with breast cancer and relation to outcome

Purpose  

Prognostic and predictive markers in breast cancer are currently determined by single analysis of protein amounts. If RNA-based multi-gene analyses enter clinical practice, simultaneous determination of currently established markers like human epidermal growth factor receptor 2 (HER2), urokinase plasminogen activator (uPA) and its inhibitor (PAI-1) would represent an elegant simplification. To investigate the correlation between RNA and protein levels, we assessed HER2, uPA and PAI-1 in patients with breast cancer. In addition, we evaluated the influence of these factors on patient outcome.