Citations

Background: Invasive leg compartment testing may be performed to diagnose chronic exertional compartment syndrome. No prior study has assessed the accuracy of leg compartment needle tip access. Purpose: This study was undertaken to describe and determine the accuracy of palpation-guided and ultrasound-guided techniques for needle tip placement into the deep and superficial posterior leg compartments by a less experienced clinician and a more experienced clinician using a cadaveric model. Study Design: Controlled laboratory study. Methods: Twenty unembalmed adult lower limb cadaveric specimens were used for the study. Two investigators, a sports medicine fellow with 10 months of musculoskeletal ultrasound experience and a staff physiatrist with 3 years of musculoskeletal ultrasound experience, each performed 1 palpation-guided and 1 ultrasound-guided colored latex dye injection into the deep and superficial posterior leg compartments of each cadaveric specimen. A blinded investigator dissected the specimens and graded them for accuracy. Results: The accuracy rates of palpation-guided (accuracy rate, 90%; 95% confidence interval [CI], 76%-97%) and ultrasound-guided (accuracy rate, 88%; 95% CI, 73%-95%) deep posterior compartment injections were statistically equivalent ( P = 1.000). All 80 injections performed into the superficial posterior compartment were accurate (accuracy rate, 100%; 95% CI, 89%-100%). The accuracy of the less experienced investigator (total injection accuracy rate, 88%; 95% CI, 73%-95%) and the more experienced investigator (total injection accuracy rate, 90%; 95% CI, 76%-97%) were not significantly different ( P = 1.000). Conclusion: Needle tip placement into the deep and superficial posterior leg compartments is relatively accurate with palpation guidance regardless of level of experience, and does not improve with the use of ultrasound guidance. Clinical Relevance: Ultrasound guidance does not appear to be indicated for routine deep or superficial posterior leg compartment pressure testing. However, this does not preclude the need for ultrasound guidance in selected clinical scenarios.

Mammalian urine contains a range of macromolecule proteins that play critical roles in renal stone formation, among which Tamm-Horsfall protein (THP) is by far the most abundant. While THP is a potent inhibitor of crystal aggregation in vitro and its ablation in vivo predisposes one of the two existing mouse models to spontaneous intrarenal calcium crystallization, key controversies remain regarding the role of THP in nephrolithiasis. By carrying out a long-range follow-up of more than 250 THP-null mice and their wild-type controls, we demonstrate here that renal calcification is a highly consistent phenotype of the THP-null mice that is age and partially gene dosage dependent, but is gender and genetic background independent. Renal calcification in THP-null mice is progressive, and by 15 mo over 85% of all the THP-null mice develop spontaneous intrarenal crystals. The crystals consist primarily of calcium phosphate in the form of hydroxyapatite, are located more frequently in the interstitial space of the renal papillae than intratubularly, particularly in older animals, and lack accompanying inflammatory cell infiltration. The interstitial deposits of hydroxyapatite observed in THP-null mice bear strong resemblances to the renal crystals found in human kidneys bearing idiopathic calcium oxalate stones. Compared with 24-h urine from the wild-type mice, that of THP-null mice is supersaturated with brushite (calcium phosphate), a stone precursor, and has reduced urinary excretion of citrate, a stone inhibitor. While less frequent than renal calcinosis, renal pelvic and ureteral stones and hydronephrosis occur in the aged THP-null mice. These results provide direct in vivo evidence indicating that normal THP plays an important role in defending the urinary system against calcification and suggest that reduced expression and/or decreased function of THP could contribute to nephrolithiasis.

Abstract Between 1935 and 1974, 3598 episodes of head trauma among Olmsted County, Minnesota, residents resulted in 1097 skull fractures. Of these, 53% were simple, 16% were depressed, 12% were compound, and 19% were basilar. The age- and sex-adjusted incidence of skull fractures was 44.3 per 100,000 person-years overall, was somewhat greater in the urban than in the rural areas of Olmsted County, and was relatively stable for the final 30 years of the study. Age-specific incidence rates were highest for the very young, and simple linear fractures were the predominant type of skull fracture in this age group and among the elderly. The male:female ratio of incidence rates varied from 2.1:1 to 4.5:1 depending on fracture type. Motor vehicle accidents accounted for 38% of the skull fractures and were a particularly important cause among young males. Falls accounted for 37% of the skull fractures and were the major cause of fractures in the elderly and pediatric age groups. The results of this population-based study may be helpful in formulating recommendations for the evaluation and management of head-injured patients.

A recently identified variant within the fat mass and obesity-associated ( FTO ) gene is carried by 46% of Western Europeans and is associated with an ~1.2 kg higher weight, on average, in adults and an ~1 cm greater waist circumference. With >1 billion overweight and 300 million obese persons worldwide, it is crucial to understand the implications of carrying this very common allele for the health of our aging population. FTO is highly expressed in the brain and elevated body mass index (BMI) is associated with brain atrophy, but it is unknown how the obesity-associated risk allele affects human brain structure. We therefore generated 3D maps of regional brain volume differences in 206 healthy elderly subjects scanned with MRI and genotyped as part of the Alzheimer's Disease Neuroimaging Initiative. We found a pattern of systematic brain volume deficits in carriers of the obesity-associated risk allele versus noncarriers. Relative to structure volumes in the mean template, FTO risk allele carriers versus noncarriers had an average brain volume difference of ~8% in the frontal lobes and 12% in the occipital lobes—these regions also showed significant volume deficits in subjects with higher BMI. These brain differences were not attributable to differences in cholesterol levels, hypertension, or the volume of white matter hyperintensities; which were not detectably higher in FTO risk allele carriers versus noncarriers. These brain maps reveal that a commonly carried susceptibility allele for obesity is associated with structural brain atrophy, with implications for the health of the elderly.

Abstract Resistance to temozolomide and radiotherapy is a major problem for patients with glioblastoma but may be overcome using the poly(ADP-ribose) polymerase inhibitor ABT-888. Using two primary glioblastoma xenografts, the efficacy of ABT-888 combined with radiotherapy and/or temozolomide was evaluated. Treatment with ABT-888 combined with temozolomide resulted in significant survival prolongation (GBM12: 55.1%, P = 0.005; GBM22: 54.4%, P = 0.043). ABT-888 had no effect with radiotherapy alone but significantly enhanced survival in GBM12 when combined with concurrent radiotherapy/temozolomide. With multicycle therapy, ABT-888 further extended the survival benefit of temozolomide in the inherently sensitive GBM12 and GBM22 xenograft lines. However, after in vivo selection for temozolomide resistance, the derivative GBM12TMZ and GBM22TMZ lines were no longer sensitized by ABT-888 in combination with temozolomide, and a similar lack of efficacy was observed in two other temozolomide-resistant tumor lines. Thus, the sensitizing effects of ABT-888 were limited to tumor lines that have not been previously exposed to temozolomide, and these results suggest that patients with newly diagnosed glioblastoma may be more likely to respond to combined temozolomide/poly(ADP-ribose) polymerase inhibitor therapy than patients with recurrent disease. [Mol Cancer Ther 2009;8(2):OF407–8]

Purpose To compare magnetic resonance imaging (MRI) and computed tomography (CT) with each other and to International Federation of Gynecology and Obstetrics (FIGO) clinical staging in the pretreatment evaluation of early invasive cervical cancer, using surgicopathologic findings as the reference standard. Patients and Methods This prospective multicenter clinical study was conducted by the American College of Radiology Imaging Network and the Gynecologic Oncology Group from March 2000 to November 2002; 25 United States health centers enrolled 208 consecutive patients with biopsy-confirmed cervical cancer of FIGO stage ≥ IB who were scheduled for surgery based on clinical assessment. Patients underwent FIGO clinical staging, helical CT, and MRI. Surgicopathologic findings constituted the reference standard for statistical analysis. Results Complete data were available for 172 patients; surgicopathologic findings were consistent with FIGO stages IA to IIA in 76% and stage ≥ IIB in 21%. For the detection of advanced stage (≥ IIB), sensitivity was poor for FIGO clinical staging (29%), CT (42%), and MRI (53%); specificity was 99% for FIGO clinical staging, 82% for CT, and 74% for MRI; and negative predictive value was 84% for FIGO clinical staging, 84% for CT, and 85% for MRI. MRI (area under the receiver operating characteristic curve [AUC], 0.88) was significantly better than CT (AUC, 0.73) for detecting cervical tumors (P = .014). For 85% of patients, FIGO clinical staging forms were submitted after MRI and/or CT was performed. Conclusion CT and MRI performed similarly; both had lower staging accuracy than in prior single-institution studies. Accuracy of FIGO clinical staging was higher than previously reported. The temporal data suggest that FIGO clinical staging was influenced by CT and MRI findings.