Magnetic resonance imaging-guided percutaneous biopsy of musculoskeletal lesions

BACKGROUND: Bone, soft-tissue, and articular lesions are often well visualized by magnetic resonance imaging. Our goal was to evaluate the diagnostic performance of magnetic resonance imaging-guided biopsies of selected musculoskeletal lesions. METHODS: In this retrospective case series, forty-five consecutive biopsies were performed in an open mid-field 0.5-T interventional magnetic resonance imaging unit with a real-time guidance system. The biopsies were performed at twenty bone, eighteen extra-articular soft-tissue, and seven intra-articular soft-tissue sites. The main reasons for using magnetic resonance imaging guidance were the need to improve lesion conspicuity compared with that provided by other imaging modalities, the need for site-specific targeting within the lesion, and the need for real-time guidance. Samples were obtained with fine-needle aspiration, core-needle biopsy, or a combination of these techniques. An independent reference standard was used to confirm the final diagnosis. Diagnostic performance was evaluated on the basis of the diagnostic yield (the proportion of biopsies yielding sufficient material for pathological evaluation) and diagnostic accuracy (sensitivity, specificity, positive predictive value, and negative predictive value). Complications were identified as well. RESULTS: The diagnostic yield was 91% (forty-one of forty-five biopsies yielded sufficient material for a diagnosis) overall, 95% (nineteen of twenty) for the bone lesions, 94% (seventeen of eighteen) for the extra-articular soft-tissue lesions, and 71% (five of seven) for the intra-articular soft-tissue lesions. With regard to the diagnostic accuracy, the sensitivity was 0.86, the specificity was 1.00, the positive predictive value was 1.00, and the negative predictive value was 0.76 in the overall group. The respective values were 0.92, 1.00, 1.00, and 0.86 for the bone lesions; 0.77, 1.00, 1.00, and 0.57 for the extra-articular soft-tissue lesions; and 1.00, 1.00, 1.00, and 1.00 for the intra-articular soft-tissue lesions. There was one complication: exacerbation of neuropathic pain related to a biopsy of a peripheral nerve sheath tumor. CONCLUSIONS: Magnetic resonance imaging-guided percutaneous biopsies of musculoskeletal lesions for which other imaging modalities might be inadequate have a good diagnostic performance overall. The performance can be very good for bone lesions, moderate for extra-articular soft-tissue lesions, and fair for intra-articular soft-tissue lesions.     

Oxidative stress in perinatal asphyxia in relation to outcome

Objective  

To study the serum levels of oxidative stress markers — malondialdehyde (MDA) and protein carbonyl in babies with perinatal asphyxia and to correlate their levels with the outcome in terms of mortality and neurodevelopmental sequelae.     

Hsp27 functions as a negative regulator of cytochrome c-dependent activation of procaspase-3

The release of mitochondrial cytochrome c by genotoxic stress induces the formation of a cytosolic complex with Apaf-1 (mammalian CED4 homolog) and thereby the activation of procaspase-3 (cas-3) and procaspase-9 (cas-9). Here we demonstrate that heat-shock protein 27 (Hsp27) inhibits cytochrome c (cyt c)-dependent activation of cas-3. Hsp27 had no effect on cyt c release, Apaf-1 and cas-9 activation. By contrast, our results show that Hsp27 associates with cas-3, but not Apaf-1 or cas-9, and inhibits activation of cas-3 by cas-9-mediated proteolysis. Furthermore, the present results demonstrate that immunodepletion of Hsp27 depletes cas-3. Importantly, treatment of cells with DNA damaging agents dissociates the Hsp27/cas-3 complex and relieves inhibition of cas-3 activation. These findings define a novel function for Hsp27 and provide the first evidence that a heat shock protein represses cas-3 activation.     

Jejunoileal bypass reversal: effect on renal function, metabolic parameters and stone formation

PURPOSE: While the effect of jejunoileal bypass (JIB) reversal has been well studied regarding hepatic function, there is little information regarding the effect of reversal on renal function and even less data regarding the metabolic urinary stone environment. We evaluated the results of JIB reversal on renal function, the urinary stone milieu and the clinical development of recurrent calculi in affected patients. MATERIALS AND METHODS: From 1995 to 2003, 4 female patients with a mean age of 48.2 years underwent JIB reversal primarily for refractory stone disease. The clinical and metabolic courses prior to and following bypass reversal were reviewed specifically to evaluate renal function, serum and urinary metabolic stone profiles, and clinical stone formation. RESULTS: At initial presentation following JIB all 4 patients had significantly increased 24-hour urinary oxalate (range 80 to 160 mg, mean 112.5, normal less than 50) and significantly low 24-hour urinary citrate (range 5 to 62 mg, mean 21.5, normal greater than 320). Following reversal 24-hour urinary oxalate normalized to between 31 and 36 mg (mean 33.75). However, 24-hour urinary citrate continued to be low (range 215 to 248 mg, mean 226.5). After JIB reversal all 4 patients continued to have new stones until the commencement of urinary alkalization, following which only 1 had 1 calculus, which occurred 47 months after reversal. After JIB mean serum creatinine was 1.48 mg/dl (range 0.8 to 1.9) and mean urinary creatinine excretion was 0.91 mg per hour (range 0.69 to 1.15). After JIB reversal mean serum creatinine was 1.28 mg/dl (range 0.6 to 2.0) and mean urinary creatinine excretion was 1.0 mg per hour (range 0.85 to 1.10). CONCLUSIONS: JIB reversal normalizes 24-hour urinary oxalate. While urinary citrate improves, it continues to be low and such patients are at high risk for recurrent stone formation. However, in this setting appropriate replacement therapy has a significant and positive impact on that propensity.     

Semen quality of industrial workers occupationally exposed to chromium

A total of sixty-one subjects occupationally exposed to chromium in an industry which manufactures chromium sulphate and fifteen control subjects from a nearby industry which does not manufacture any chromium related compounds were studied. The history of each subject was recorded on pre-designed form through interview and a routine medical examination was carried out. Blood samples (5-6 ml) were collected for the estimation of chromium and semen samples were collected for semen analysis and the determination of copper and zinc levels in the seminal plasma. Clinical examination revealed nasal perforation in 10 subjects (out of 61) in the exposed group as compared to none in the control group. A significantly higher level of chromium was observed in the blood of the exposed workers as compared to the control. The concentration of zinc in seminal plasma was lower while the level of copper was higher in the exposed group as compared to the control. However, these changes were not statistically significant. Statistically significant higher numbers of morphologically abnormal sperms were noticed in the exposed group with respect to the control. Further analysis of the data indicated that about 53% of the exposed subjects showed less than 30% normal forms as compared to 10% in control subjects. However, no significant alterations in semen volume, liquefaction time, mean pH value, sperm viability, concentration or motility, were noticed between chromium exposed and unexposed workers. The data also indicates that exposure to chromium has some effect on human sperm as a significant positive correlation (r=0.301) was observed between percentages of abnormal sperm morphology and blood chromium levels (p=0.016) after pooling all the data of the control and exposure groups.     

Protection by dendritic cells-based HIV synthetic peptide cocktail vaccine: preclinical studies in the SHIV-rhesus model

Vaccine development efforts against HIV-1 have been hindered because of the high mutation rate of the virus, and limitations for direct testing of HIV antigens in animal models to discern the nature of protective immunity. We developed a multivalent vaccine comprised of highly conserved HIV envelope peptide cocktail focused on priming antigen-specific helper T cell and CTL responses. Here we report protection of rhesus macaques against pathogenic SHIV(89.6P) challenge through priming cell-mediated immunity by prophylactic vaccination with the peptide-cocktail delivered by dendritic cells. Compared to monkeys mock-vaccinated or immunized with the peptide cocktail using IFA, vaccination with peptide cocktail-pulsed DC showed significant protection from AIDS-associated mortality and reduction in plasma viremia to undetectable levels.