Citations

Purpose To report a multicenter experience treating anal canal cancer patients with concurrent chemotherapy and intensity-modulated radiation therapy (IMRT). Patients and Methods From October 2000 to June 2006, 53 patients were treated with concurrent chemotherapy and IMRT for anal squamous cell carcinoma at three tertiary-care academic medical centers. Sixty-two percent were T1-2, and 67% were N0; eight patients were HIV positive. Forty-eight patients received fluorouracil (FU)/mitomycin, one received FU/cisplatin, and four received FU alone. All patients underwent computed tomography–based treatment planning with pelvic regions and inguinal nodes receiving a median of 45 Gy. Primary sites and involved nodes were boosted to a median dose of 51.5 Gy. All acute toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 3.0. All late toxicity was scored using Radiation Therapy Oncology Group criteria. Results Median follow-up was 14.5 months (range, 5.2 to 102.8 months). Acute grade 3+ toxicity included 15.1% GI and 37.7% dermatologic toxicity; all acute grade 4 toxicities were hematologic; and acute grade 4 leukopenia and neutropenia occurred in 30.2% and 34.0% of patients, respectively. Treatment breaks occurred in 41.5% of patients, lasting a median of 4 days. Forty-nine patients (92.5%) had a complete response, one patient had a partial response, and three had stable disease. All HIV-positive patients achieved a complete response. Eighteen-month colostomy-free survival, overall survival, freedom from local failure, and freedom from distant failure were 83.7%, 93.4%, 83.9%, and 92.9%, respectively. Conclusion Preliminary outcomes suggest that concurrent chemotherapy and IMRT for anal canal cancers is effective and tolerated favorably compared with historical standards.

Introduction The earliest lesion in the kidneys of idiopathic calcium oxalate stone formers is deposition of calcium phosphate in the interstitium, termed a Randall's plaque. Yet the cellular and molecular factors leading to their formation are unknown. Methods The influence of urinary proteins on adhesion of preformed calcium oxalate crystals to rat continuous inner medullary collecting duct (cIMCD) cells was studied in vitro, and cIMCD cells were also exposed to calcifying media containing β-glycerophosphate for up to 28 days. Renal tissue was obtained from a stone-forming and non-stone-forming individual at the time of nephrectomy. These nanoparticles, isolated from renal stones obtained at the time of surgical resection, were analyzed and propagated in standard cell culture medium. Results Urinary proteins influence crystal adhesion to renal epithelial cells, and this activity is abnormal in the urine of stone-forming patients. cIMCD cells assumed an osteoblastic phenotype when exposed to the calcifying medium, expressing two bone matrix proteins (osteopontin and bone sialoprotein) that were also identified in the kidney of the stone-forming patient and associated with crystal deposition. Nanoparticles were propagated from the majority of renal stones. Isolates were susceptible to selected metabolic inhibitors and antibiotics and contained conserved bacterial proteins and deoxyribonucleic acid (DNA). Conclusions These results suggest new paradigms for Randall's plaque formation and idiopathic calcium oxalate stone disease. It seems unlikely that these events are driven solely by physical chemistry; rather, they are critically influenced by specific proteins and cellular responses, and understanding these events will provide clues toward novel therapeutic targets.

Background The origin of advanced arterial and renal calcification remains poorly understood. Self-replicating, calcifying entities have been detected and isolated from calcified human tissues, including blood vessels and kidney stones, and are referred to as nanobacteria. However, the microbiologic nature of putative nanobacteria continues to be debated, in part because of the difficulty in discriminating biomineralized microbes from minerals nucleated on anything else (eg, macromolecules, cell membranes). To address this controversy, the use of techniques capable of characterizing the organic and mineral content of these self-replicated structures at the submicrometer scale would be beneficial. Methods Calcifying gram-negative bacteria ( Caulobacter crescentus, Ramlibacter tataouinensis) used as references and self-replicating calcified nanoparticles cultured from human samples of calcified aneurysms were examined using a scanning transmission x-ray microscope (STXM) at the Advanced Light Source at Lawrence Berkeley National Laboratory. This microscope uses a monochromated and focused synchrotron x-ray beam (80-2,200 eV) to yield microscopic and spectroscopic information on both organic compounds and minerals at the 25 nm scale. Results High-spatial and energy resolution near-edge x-ray absorption fine structure (NEXAFS) spectra indicative of elemental speciation acquired at the C K-edge, N K-edge, and Ca L 2,3 -edge on a single-cell scale from calcified C. crescentus and R. tataouinensis displayed unique spectral signatures different from that of nonbiologic hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ). Further, preliminary NEXAFS measurements of calcium, carbon, and nitrogen functional groups of cultured calcified nanoparticles from humans revealed evidence of organics, likely peptides or proteins, specifically associated with hydroxyapatite minerals. Conclusion Using NEXAFS at the 25 nm spatial scale, it is possible to define a biochemical signature for cultured calcified bacteria, including proteins, polysaccharides, nucleic acids, and hydroxyapatite. These preliminary studies suggest that nanoparticles isolated from human samples share spectroscopic characteristics with calcified proteins.

Although previous studies have questioned the factor structure of the Social Skills Rating System (SSRS), it continues to be one of the most prominent measures used to assess child social skills. Previous examinations of the SSRS have been conducted on samples that differ demographically from the standardization sample. The present study presents a factor analysis of the SSRS parent elementary form, social skills domain, in a sample of 298 non-referred children. Similar to previous research, the factor structure proposed by the authors of the SSRS was not replicated. An alternative 2-factor model based on previous research also did not adequately fit the data. Other psychometric properties, such as the range of interitem correlations, were evaluated and did not meet suggested guidelines for test construction. Despite its psychometric difficulties, the SSRS was related to history of treatment for peer difficulties.

The secretin receptor is prototypic of Class II GPCRs (G-protein-coupled receptors), based on its structural and functional characteristics and those of its natural agonist ligand. Secretin represents a linear 27-residue peptide with diffuse pharmacophoric domain. The secretin receptor includes the typical signature sequences for this receptor family within its predicted transmembrane segments and the highly conserved six cysteine residues contributing to three intradomain disulfide bonds within its long N-terminus. This domain is critical for secretin binding based on receptor mutagenesis and photoaffinity labelling studies. Full agonist analogues of secretin incorporating a photolabile moiety at various positions throughout the pharmacophore covalently label residues within this region, while only N-terminal probes have labelled the core helical bundle domain. Combining insights coming from receptor structural studies, peptide structure–activity relationship considerations, photoaffinity labelling, and application of fluorescence techniques has resulted in the development of a working model of the secretin–receptor complex. This supports the initial docking of the peptide agonist within a cleft in the receptor N-terminus, providing the opportunity for an endogenous sequence within that domain to interact with the core of the receptor. This interaction is believed to be key in the molecular basis of conformational change associated with activation of this receptor. The site of action of this endogenous agonist could also provide a possible target for small molecule agonists to act.

Background— Cardiac troponin T (cTnT) and B-type natriuretic peptide (BNP) have been used to estimate prognosis in heart failure; however, most studies have evaluated decompensated patients with single measurements. To determine if there are advantages to serial measurements, we evaluated stable chronic heart failure patients every 3 months for 2 years. Methods and Results— A cohort of 190 New York Heart Association class III–IV heart failure patients was prospectively enrolled from June 2001 to January 2004. Primary end points were death, cardiac transplantation, or hospitalization. At study enrollment cTnT was <0.01 ng/mL in 87 (45.8%) patients, 0.01 to 0.03 ng/mL in 50 (26.3%) patients, and >0.03 ng/mL in 53 (27.9%) patients. An increase in cTnT above normal (<0.01 ng/mL) carried a 3.4-fold increased risk ( P =0.019). Further increases (≥20%) from an elevated level worsened the overall risk (hazard ratio, 5.09; P <0.001). BNP was elevated (>95th percentile for age and gender normal population) in 122 (64.2%) patients. An elevation of BNP from normal at any time during the study was associated with a poor outcome, but, once elevated, further changes in BNP (increases or decreases) remained associated with the same risk (hazard ratio, 5.09; P <0.001). Combined elevations of cTnT (>0.03 ng/mL) and BNP defined the highest risk group (hazard ratio, 8.58; P <0.001). Conclusions— Elevations of cTnT or BNP from normal detected at any time during clinical follow-up in ambulatory patients with chronic heart failure are highly associated with an increased risk of events. Further increases in cTnT contribute to additional risk. Combined elevations of cTnT and BNP contribute the highest risk. The ability to monitor changes by serial measurements adds substantially to the assessment of risk in this patient population.

AbstractThe molecular structure and agonist-induced conformational changes of class II G protein-coupled receptors are poorly understood. In this work, we developed and characterized a series of dual cyan fluorescent protein (CFP)-tagged and yellow fluorescent protein (YFP)-tagged secretin receptor constructs for use in various functional and fluorescence analyses of receptor structural variants. CFP insertions within the first or second intracellular loop domains of this receptor were tolerated poorly or partially, respectively, in receptors tagged with a carboxyl-terminal yellow fluorescent protein that itself had no effect on secretin binding or cAMP production. A similar CFP insertion into the third intracellular loop resulted in a plasma membrane-localized receptor that bound secretin and signaled normally. This fully active third-loop variant exhibited a significant decrease in fluorescence resonance energy transfer signals that were recorded with an acousto-optic tunable filter microscope after exposure to secretin agonist but not to a receptor antagonist. These data demonstrate changes in the relative positions of intracellular structures that support a model for secretin receptor activation.