Challenges in quantifying and characterizing dissolved organic carbon: Sampling, isolation, storage, and analysis.

Despite the advancements in analytical techniques, there are still great challenges and difficulties in accurately and effectively quantifying and characterizing dissolved organic carbon (DOC) in environmental samples. The objectives of this review paper are (a) to understand the roles and variability of DOC along the water continuum; (b) to identify the constraints, inconsistences, limitations, and artifacts in DOC characterization; and (c) to provide recommendations and remarks to improve the analytical accuracy. For the first objective, we summarize the four ecological and engineering roles of DOC along the water continuum from source water to municipal utility, including nutrients and energy sources, controlling the fates of micropollutants, buffering capacity, and treatability and precursors of disinfection byproducts. We also discuss three major challenges in DOC analysis, including spatial and temporal variations, degradability and stability, and unknown structures and formulas. For the second objective, we review the procedures and steps in DOC analysis, including sampling in diverse environmental matrices, isolation of DOC fraction, storage and preservation techniques, and analyses on bulk chemical characteristics. We list and discuss the available options and evaluate the advantages and disadvantages of each choice. Last, we provide recommendations and remarks for each stage: sampling, isolation, storage, and analysis.

Phenotypic Variation in Mitochondria-Related Performance Traits Across New Zealand Snail Populations.

Mitochondrial function is critical for energy homeostasis and should shape how genetic variation in metabolism is transmitted through levels of biological organization to generate stability in organismal performance. Mitochondrial function is encoded by genes in two distinct and separately inherited genomes-the mitochondrial genome and the nuclear genome-and selection is expected to maintain functional mito-nuclear interactions. The documented high levels of polymorphism in genes involved in these mito-nuclear interactions and wide variation for mitochondrial function demands an explanation for how and why variability in such a fundamental trait is maintained. Potamopyrgus antipodarum is a New Zealand freshwater snail with coexisting sexual and asexual individuals and, accordingly, contrasting systems of separate vs. co-inheritance of nuclear and mitochondrial genomes. As such, this snail provides a powerful means to dissect the evolutionary and functional consequences of mito-nuclear variation. The lakes inhabited by P. antipodarum span wide environmental gradients, with substantial across-lake genetic structure and mito-nuclear discordance. This situation allows us to use comparisons across reproductive modes and lakes to partition variation in cellular respiration across genetic and environmental axes. Here, we integrated cellular, physiological, and behavioral approaches to quantify variation in mitochondrial function across a diverse set of wild P. antipodarum lineages. We found extensive across-lake variation in organismal oxygen consumption and behavioral response to heat stress and differences across sexes in mitochondrial membrane potential but few global effects of reproductive mode. Taken together, our data set the stage for applying this important model system for sexual reproduction and polyploidy to dissecting the complex relationships between mito-nuclear variation, performance, plasticity, and fitness in natural populations.

Prospective study of therapeutic spiral enteroscopy in patients with surgically altered anatomy.

BACKGROUND: Spiral enteroscopy is rapidly emerging, along with double- and single-balloon enteroscopy, as a paramount method to evaluate lesions in the deep small bowel. While the latter two methods have been used to manage patients with surgically altered anatomy, there are few reports on the role of spiral enteroscopy in this group. Our principal aim was to characterize the therapeutic uses of spiral enteroscopy in patients with surgically altered anatomy. METHODS AND RESULTS: Patients with surgically altered anatomy who failed management with conventional endoscopic methods for therapeutic indications were included in this prospective series at our tertiary referral center. The spiral technique was used to control variceal bleeding, dilate enteral anastomotic narrowing, and perform pancreaticobiliary interventions in seven patients. The cases were performed quickly and effectively and the need for surgery was obviated in all cases. CONCLUSION: The spiral enteroscopy system has significant therapeutic potential in patients with surgically altered anatomy.

Esophageal intraepithelial eosinophils in dysphagic patients with gastroesophageal reflux disease.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) often complain of dysphagia and are frequently found to have intraepithelial eosinophils on esophageal biopsy. AIM: The aim of this study was to investigate the relationship between dysphagia and the number of intraepithelial eosinophils in patients with GERD. METHODS: Review of all patients studied in our esophageal function laboratory from 1999 to 2007 identified 1,533 patients with increased esophageal acid exposure. Patients who complained of dysphagia without mechanical or motor causes were identified and divided into three groups based on whether dysphagia was their primary, secondary or tertiary symptom. A control group consisted of randomly selected GERD patients with no dysphagia. The highest number of intraepithelial eosinophils per high-power field (HPF) in biopsies from the squamocolumnar junction (SCJ) and esophageal body was compared across groups. RESULTS: There were 71 patients with unexplained dysphagia. Dysphagia was the primary symptom in 13 (18%), secondary symptom in 34 (48%), and tertiary symptom in 24 (34%) patients. The number of eosinophils differed between the four groups, with the highest number in those with dysphagia as the primary symptom (P = 0.0007). This relationship persisted whether biopsies were from the SCJ (P = 0.0057) or esophageal body (P = 0.0096). CONCLUSION: An association exists between the number of intraepithelial eosinophils and dysphagia in GERD patients, with the highest number of eosinophils in those with the primary symptom of dysphagia.

Induction of a chronic disease state in patients with smoldering or indolent multiple myeloma by targeting interleukin 1{beta}-induced interleukin 6 production and the myeloma proliferative component.

OBJECTIVE: To conduct in vitro studies as well as a phase 2 clinical trial in patients with smoldering or indolent multiple myeloma to determine if interleukin 1 (IL-1) inhibitors can delay or prevent active myeloma. PATIENTS AND METHODS: Stromal cells were cocultured with IL-1beta-expressing myeloma cells in the presence of dexamethasone, IL-1 receptor antagonist (IL-1Ra), or both. Levels of interleukin 6 (IL-6) and of apoptosis were also quantified. Between November 19, 2002, and May 24, 2007, 47 patients were enrolled in the study and subsequently treated with IL-1Ra. In 25 (53%) of the 47 study patients, low-dose dexamethasone (20 mg/wk) was added. The primary end point was progression-free survival (PFS). RESULTS: In vitro, IL-1Ra was superior to dexamethasone at inhibiting IL-6 production; maximal IL-6 inhibition and apoptosis induction were achieved by addition of both IL-1Ra and dexamethasone. In the clinical trial, 3 patients achieved a minor response to IL-1Ra alone; 5 patients achieved a partial response and 4 patients a minor response after addition of dexamethasone. Seven patients showed a decrease in the plasma cell labeling index that paralleled a decrease in high-sensitivity C-reactive protein (hs-CRP) levels. The median overall PFS was 37.5 months. The median PFS for patients without (n=12) or with (n=35) a greater than 15% decrease in 6-month vs baseline hs-CRP levels was 6 months and more than 3 years, respectively (P=.002). Disease stability was maintained in 8 patients who received therapy for more than 4 years. CONCLUSION: In patients with smoldering or indolent multiple myeloma who were at risk of progression to active myeloma, treatment with IL-1 inhibitors decreased the myeloma proliferative rate and hs-CRP levels in those who responded, leading to a chronic disease state and an improved PFS. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT00635154.

The utility of intraluminal impedance in patients with gastroesophageal reflux disease-like symptoms but normal endoscopy and 24-hour pH testing.

BACKGROUND & AIMS: Fifty percent of patients with gastroesophageal reflux disease-like symptoms and negative endoscopy have negative 24-hour pH testing, suggesting that symptoms are not caused by abnormal esophageal acid exposure. Multichannel intraluminal impedance (MII)-24-hour pH allows the recognition of major acid, minor acid, nonacid, and gas reflux. Recorded symptoms can be correlated with all reflux events (eg, acid, minor acid, nonacid, and gas) and a symptom score can be generated. We aimed to determine whether the Symptom Index (SI) obtained using MII-pH identified an association of symptoms with reflux events in nonclassic acid-reflux disease. METHODS: Thirty-seven patients with heartburn or regurgitation, negative endoscopy, and 24-hour pH were enlisted. Acid suppression was stopped, a 24-hour MII-pH test was performed, and an SI was calculated for major acid reflux alone and for all reflux episodes including major, minor, and nonacid. On this basis patients were divided into 4 groups: (1) standard acid reflux: positive standard pH test; (2) acid sensitive: positive SI for major acid but normal pH test; (3) general reflux: positive SI for major, minor, and nonacid combined, but not for major acid alone; and (4) no reflux: negative SI. RESULTS: Six patients (16%) had standard reflux, 10 patients (27%) had acid-sensitive esophagus, 14 patients (38%) had general reflux, and 7 patients (19%) had a negative SI. CONCLUSIONS: Fifty-seven percent of patients received a diagnosis unachievable with standard pH testing (38% had symptoms associated with general reflux and 19% had no reflux symptom associations). These findings support a potential role for MII-pH testing in this difficult group.

R-(-)-gossypol (AT-101) activates programmed cell death in multiple myeloma cells.

OBJECTIVE: Bcl-2 family proteins play a critical role in malignancies by regulating the balance between cell survival and apoptosis. R-(-)-gossypol (AT-101) is a small molecule that mimics the BH3 domain of cellular Bcl-2 inhibitors and interferes with the function of prosurvival Bcl-2 proteins. We examined the cytotoxicity of AT-101 in the context of multiple myeloma, a fatal hematological malignancy. MATERIALS AND METHODS: Multiple myeloma cell lines and primary cells obtained from multiple myeloma patients were used to investigate the effects of AT-101. Cell viability, apoptosis, and apoptosis pathways were examined using conventional viability assays, flow cytometry, and immunoblots. RESULTS: AT-101 was not only cytotoxic to conventional multiple myeloma cell lines, but was also effective against drug-resistant cell lines and primary multiple myeloma patient cells. Furthermore, AT-101 decreased proliferation of multiple myeloma cell lines in the presence of marrow stromal cells, indicating that this drug may overcome the protective effect of the microenvironment that is important for multiple myeloma cell proliferation and survival. Apoptosis was activated via the mitochondrial pathway in multiple myeloma cell lines treated with AT-101 as demonstrated by an increased Bax to Bcl-2 ratio, mitochondrial membrane depolarization, and caspase activation. Finally, our studies demonstrated that AT-101 exhibits potent synergy with dexamethasone, a valuable therapeutic for multiple myeloma. CONCLUSION: These data suggest that the activity of AT-101 may be highly relevant to multiple myeloma disease biology and may represent an option for treatment of patients with this disease.

Cytokine and chemokine profiles in multiple myeloma; significance of stromal interaction and correlation of IL-8 production with disease progression.

Multiple myeloma (MM) is a product of interactions between tumor plasma cells and multiple cell types native to the bone marrow (BM). We have used antibody array technology to examine the proteins produced by BM stromal cells in response to stimulation by BM taken from patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and MM. We observed increased production of the chemokine IL-8 by stromal cells co-cultured with supernatants from bone marrow cells of patients with active myeloma. IL-8 production is correlated with active disease and is dependent upon IL-1beta and NF-kappaB signaling. Consistent with the pro-angiogenic activity of IL-8, increased BM microvessel density (MVD) correlated with stimulation of stromal cell IL-8 production. In addition, the majority of MM cell lines and MM patient plasma cells were found to express IL-8 receptors CXCR1 and CXCR2. We conclude that stromal cell IL-8 production parallels MM disease activity, is IL-1beta induced, and correlates with bone marrow angiogenesis.

Differential expression of vascular endothelial growth factors and their receptors in multiple myeloma.

BACKGROUND AND OBJECTIVES: Bone marrow angiogenesis is increased in patients with multiple myeloma (MM) and correlates with disease stage. DESIGN AND METHODS: Previous studies of quantifying vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) in plasma cells from patients at different stages of MM found no significant difference in expression between overt MM and earlier pre-malignant stages of the disease namely, monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). RESULTS: In this report we used quantitative flow cytometry to study cytoplasmic VEGF (cyVEGF) expression (measured as antibody binding capacity) in plasma cells from patients with MM (n = 22), MGUS/SMM (n = 12), and AL-amyloidosis (AL) (n = 9). CyVEGF expression was higher in MM (169,591) than in MGUS/SMM (144,858), or AL (106,011) although these differences were not statistically significant. Using an indirect VEGFR assay that measures VEGF binding, we found VEGF receptors on plasma cells from all groups of patients, with the lowest expression on plasma cells from normal individuals. We detected VEGF R1, VEGF R2, and VEGF R3 on plasma cells from all groups of patients and found receptor expression predominantly in the subset of CD45-positive plasma cells. INTERPRETATION AND CONCLUSIONS: This study supports the concept that VEGF is involved in the pathogenesis of MM, and suggests that VEGF may differentially affect a subset of plasma cells.

Identification of two groups of smoldering multiple myeloma patients who are either high or low producers of interleukin-1.

Interleukin-1beta (IL-1beta) is abnormally expressed by the plasma cells obtained from myeloma patients, and it is a potent inducer of the important myeloma growth factor, IL-6. We investigated whether levels of IL-1beta biologic activity might distinguish different groups of patients with smoldering multiple myeloma (SMM). We measured the ability of IL-6 production by bone marrow stromal cells to serve as a surrogate marker for IL-1beta biologic activity. Using this IL-1beta bioassay, we found that it is sensitive at < 1 pg/ml of recombinant IL-1beta and that IL-1beta biologic activity is detectable with either mature or pro-IL-1beta-transduced myeloma cell lines. Patients with active myeloma induced quantitatively higher levels of stromal cell IL-6 production when compared with those with monoclonal gammopathy of undetermined significance (MGUS). The bioassay distinguished two groups of SMM patients, those who were high producers, similar to patients with active MM, and those who were low producers, comparable to MGUS patients. IL-1 antagonists inhibited the paracrine IL-6 production by > or = 90% in the majority of patients with an elevated IL-6 level. Based on such studies, it may be possible to predict patients that will progress to active MM and to delay or prevent this progression with IL-1 antagonists.

Elevated serum B-lymphocyte stimulator levels in patients with familial lymphoproliferative disorders.

PURPOSE: Serum B-lymphocyte stimulator (BLyS) levels have been found to be elevated in a number of immune disease models. Therefore, we sought to establish whether BLyS levels were elevated in patients with B-cell lymphoproliferative disorders and to determine whether elevated BLyS levels correlated with clinical characteristics of the disease. PATIENTS AND METHODS: Specimens were collected from the peripheral blood of individuals diagnosed with B-cell chronic lymphocytic leukemia (B-CLL; n = 70) or from age- and sex-matched patients seen at the same institution (n = 41). Serum BLyS levels were determined by enzyme-linked immunosorbent assay, and sequencing of the BLyS promoter was performed by conventional methods and confirmed by restriction fragment length polymorphism analysis. RESULTS: We found that elevated BLyS levels were more common in patients with familial B-CLL than individuals with sporadic B-CLL or normal controls. Because of this association, we sequenced the BLyS promoter in patients with B-CLL and normal controls and identified a polymorphic site, -871 C/T. We found that the wild-type sequence was significantly underrepresented in patients with familial B-CLL (4%) compared with patients with sporadic B-CLL (30%; P = .01) or controls (24%; P = .04). Furthermore, using a luciferase reporter under control of the BLyS promoter containing either a C or a T at position -871, we found that the reporter construct containing a T at -871 had a 2.6-fold increase in activity (P = .004). CONCLUSION: Our data suggest serum BLyS levels are elevated in patients with familial B-CLL and that elevated BLyS levels correlate with the presence of a T at -871 in the BLyS promoter.

New state record for the Asian tiger mosquito, Aedes albopictus (Skuse).

The 1st Aedes albopictus specimen recorded from Colorado was found near a tire storage site in Ft. Lupton on July 9, 2003. Intensified surveillance at the site in 2003 did not result in collection of any other specimens that season, leading to speculation that it was an isolated incident rather than an actual introduction for the species. Control measures against larvae and adult mosquitoes were conducted in the area to further reduce the likelihood of establishment of a viable population. However, subsequent surveillance during the 2004 mosquito season resulted in collection of 21 additional specimens at and near the Ft. Lupton site, possibly representing an established viable population of the species.

Improvement of gastroesophageal reflux symptoms after radiofrequency energy: a randomized, sham-controlled trial.

BACKGROUND & AIMS: Gastroesophageal reflux disease is a prevalent disorder that often requires long-term medical therapy or surgery. The United States Food and Drug Administration recently cleared new endoluminal gastroesophageal reflux disease treatments; however, no controlled trials exist. METHODS: We randomly assigned 64 gastroesophageal reflux disease patients to radiofrequency energy delivery to the gastroesophageal junction (35 patients) or to a sham procedure (29 patients). Principal outcomes were reflux symptoms and quality of life. Secondary outcomes were medication use and esophageal acid exposure. After 6 months, interested sham patients crossed over to active treatment. RESULTS: At 6 months, active treatment significantly and substantially improved patients' heartburn symptoms and quality of life. More active vs. sham patients were without daily heartburn symptoms (n = 19 [61%] vs. n = 7 [33%]; P = 0.05), and more had a >50% improvement in their gastroesophageal reflux disease quality of life score (n = 19 [61%] vs. n = 6 [30%]; P = 0.03). Symptom improvements persisted at 12 months after treatment. At 6 months, there were no differences in daily medication use after a medication withdrawal protocol (n = 17 [55%] vs. n = 14 [61%]; P = 0.67) or in esophageal acid exposure times. There were no perforations or deaths. CONCLUSIONS: Radiofrequency energy delivery significantly improved gastroesophageal reflux disease symptoms and quality of life compared with a sham procedure, but it did not decrease esophageal acid exposure or medication use at 6 months. This procedure represents a new option for selected symptomatic gastroesophageal reflux disease patients who are intolerant of, or desire an alternative to, traditional medical therapies.

The gastric cardia: to be or not to be?

The origin and biologic significance of cardiac gastric mucosa are controversial. Traditionally, it has been considered native mucosa and part of normal foregut development. It has been recently suggested that cardiac mucosa is present only as a metaplastic response to gastroesophageal reflux disease and therefore always abnormal. We evaluated the esophagogastric junction in 100 pediatric autopsy samples to determine the existence, characteristics, and length of pure cardiac mucosa at different ages. No patient had a history of gastroesophageal reflux disease. Cardiac mucosa immediately distal and contiguous to the esophageal squamous mucosa was identified in all 100 samples, varying in length from 0.1 to 3 mm; the mean length was 1 mm. There was an inverse correlation between patient age and length of cardiac mucosa; gender had no influence on measured length. Three patients had mild to moderate histologic esophagitis; two had gastritis. No metaplastic features or Helicobacter pylori were identified. These findings support the concept that there is a normal, variably narrow developmental zone at the esophagogastric junction covered by cardiac mucosa and is present at birth. When cardiac type mucosa is found in biopsy material, it does not necessarily represent evidence of a mucosal metaplastic response to gastroesophageal reflux disease.