Effect of carbon source during enrichment on BTEX degradation by anaerobic mixed bacterial cultures.

A comprehensive study on the effects of different carbon sources during the bacterial enrichment on the removal performances of benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds when present as a mixture was conducted. Batch BTEX removal kinetic experiments were performed using cultures enriched with individual BTEX compounds or BTEX as a mixture or benzoate alone or benzoate-BTEX mixture. An integrated Monod-type non-linear model was developed and a ratio between maximum growth rate (µ max) and half saturation constant (Ks) was used to fit the non-linear model. A higher µ max/Ks indicates a higher affinity to degrade BTEX compounds. Complete removal of BTEX mixture was observed by all the enriched cultures; however, the removal rates for individual compounds varied. Degradation rate and the type of removal kinetics were found to be dependent on the type of carbon source during the enrichment. Cultures enriched on toluene and those enriched on BTEX mixture were found to have the greatest µ max/Ks and cultures enriched on benzoate had the least µ max/Ks. Removal performances of the cultures enriched on all different carbon sources, including the ones enriched on benzoate or benzoate-BTEX mixture were also improved during a second exposure to BTEX. A molecular analysis showed that after each exposure to the BTEX mixture, the cultures enriched on benzoate and those enriched on benzoate-BTEX mixture had increased similarities to the culture enriched on BTEX mixture.

Radioassay-Based Approach to Investigate Fate and Transformation of Conjugated and Free Estrogens in an Agricultural Soil.

Estrogens, a potent group of endocrine disruptors toward aquatic species, are primarily excreted as conjugates from humans and animals. Radioassay-based approaches with detailed speciation have been frequently conducted for environmental-fate studies for pesticides; however, such techniques have not been exploited for reproductive hormones, and especially for hormone conjugates. This article describes a simple, robust, and high-mass-recovery approach to investigate the fate and transformation of a prototype estrogen conjugate, that is, 17ß-estradiol-3-glucuronide (E2-3G), and its metabolites (free estrogens) in a laboratory soil and water matrix without the need for enzymatic cleavage and/or fluorescent derivatization. E2-3G and its metabolites were baseline resolved in a single run using high-performance liquid chromatography (HPLC) and quantified by liquid scintillation counting of the HPLC effluents. Transformation of E2-3G and the disposition of its metabolites--the free estrogens 17ß-estradiol and estrone--into aqueous, sorbed, and gaseous phases, were adequately accounted for in a soil-water batch system. High mass balances ranging from 99.0% to 114.1% were obtained. Although the method gave lower sensitivity (parts per billion) than tandem mass spectrometer (parts per trillion), it offered sufficient chromatographic resolution and sensitivity to study the fate of labile estrogens in environmental matrices, using the concentration range of this study. An additional advantage of the approach was the relatively low cost of the instrumentation employed. The presented approach can be successfully applied to study the fate of conjugated hormones and their metabolites in the environment allowing simultaneous discernment of complex fate and transformation processes in soil, water, and gas.

Fate and transformation of an estrogen conjugate and its metabolites in agricultural soils.

In the environment, conjugated estrogens are nontoxic but may hydrolyze to their potent unconjugated, 'free' forms. Compared to free estrogens, conjugated estrogens would be more mobile in the environment because of their higher water solubility. To identify the fate of a conjugated estrogen in natural agricultural soils, batch experiments were conducted with a (14)C labeled prototype conjugate, 17ß-estradiol-3-glucuronide (E2-3G). Initially, aqueous dissipation was dominated by biological hydrolysis of E2-3G and its oxidized metabolite, estrone glucuronide (E1-3G), both of which were transformed into the free estrogens, 17ß-estradiol (E2) and estrone (E1), respectively. Following hydrolysis, hydrophobic sorption interactions of E2 and E1 dominated. Depending on soil organic matter contents, dissolved E2-3G persisted from 1-14 d, which was much longer than what others reported for free estrogens (generally <24 h). Biodegradation rate constants of E2-3G were smaller in the subsoil (0.01-0.02 h(-1)) compared to topsoil (0.2-0.4 h(-1)). Field observations supported our laboratory findings where significant concentrations (425 ng L(-1)) of intact E2-3G were detected in groundwater (6.5-8.1 m deep) near a swine (Sus scrofa domesticus) farm. This study provides evidence that conjugate estrogens may be a significant source of free estrogens to surface water and groundwater.

Groundwater remediation using an enricher reactor-permeable reactive biobarrier for periodically absent contaminants.

A combined enricher reactor (ER)-permeable reactive biobarrier (PRBB) system was developed to treat groundwater with contaminants that appear in batches. An enricher reactor is an offline reactor used to enrich contaminant degraders by supplying necessary growth materials, and the enriched degraders are used to augment PRBB to increase its performance after a period of contaminant absence. Bench-scale experiments on PRBBs with and without bacterial supply from the enricher reactor were conducted to evaluate PRBB removal performances for benzene, which was used as a model contaminant. Benzene absence periods of 10 and 25 days were tested in the presence and absence of ethanol. The PRBBs without the bioaugmentation from the enricher reactor experienced a decrease in performance from approximately 65% to 30% after benzene reappeared. The presence of ethanol accelerated the benzene removal performance recovery of PRBBs. The 25-day benzene absence period caused greater changes in the bacterial community structure, regardless of the ethanol availability.

PET-CT upstaging of unilateral operable breast cancer and its correlation with molecular subtypes.

CONTEXT: Prognosis and survival rates for breast cancer vary greatly depending on the cancer stage of the patient. Instead of a step-by-step approach using multiple investigations, we can get all the information about the metastatic load of the disease in PET-CT imaging by one single investigation. There is also a correlation between prognosis, FDG uptake, and molecular subtype of breast cancer (Luminal A, Luminal B, Human epidermal growth factor receptor 2 (HER2) positive and Triple-negative). Pre-treatment baseline PET-CT scan was done in 156 unilateral early and operable breast cancer patients from November 2017 to April 2019 in our prospective observational study. AIMS: To evaluate the utility of PET-CT in staging and upstaging of early and operable breast cancer by detection of unsuspected lymph nodes and distant organ metastases.To determine the prognostic association between SUVmax of the primary breast lesion in the upstaged cases and the molecular subtypes. RESULTS: Thus, PET-CT can serve as one-stop imaging in unilateral operable early breast cancer patients for upstaging and prognostication based on the correlation of SUVmax with molecular subtypes of breast lesions in patients who will surely benefit from whole-body imaging.Out of 156 patients, approximately 27 patients were upstaged after pre-treatment PET CT.Six patients were upstaged to stage IIIC and 21 patients were upstaged to IV.Regional nodes like internal mammary and supraclavicular nodes were detected in 7 patients and 5 patients, respectively, out of 156 patients.Non-regional distant nodes and organ metastases were detected in 11 and 18 patients out of 156 patients.Most common molecular subtype detected in the upstaged cases in our study was Luminal A (13 patients) followed by Triple negative (6), Luminal B (3) and HER2-neu-positive subtypes (1). CONCLUSIONS: FDG PET-CT is a substantial modality to provide information on regional, non regional lymph nodes and distant metastases in early operable breast cancer.It helps in evaluating the whole body metastatic burden in a single sitting, therefore, reducing the need for multiple investigations.SUVmax association of the index lesion with molecular subtype in the FDG PET scanning can serve as a prognostication factor in operable early breast cancer patients.

The unforeseen orbital tumor.

Inflammatory myofibroblastic tumor is a rare group of neoplasms showing a mixture of spindle-shaped myofibroblasts or fibroblasts and a variable amount of inflammatory cells (eosinophils, plasma cells, and lymphocytes). They are not usually included in the differential diagnosis of nodules and masses because of their rarity, therefore, remaining an underdiagnosed entity. We report one such rare case in a 3-year-old female.

Transient suppression of processing during rapid serial visual presentation: Acquired distinctiveness of probes modulates the attentional blink.

The attentional blink is revealed in studies of rapid serial visual processing, in which observers view a stream of letters presented sequentially at the same location in a visual display. Reporting the identity of a specially marked letter (the target) amidst distractors causes a transient loss of accuracy for detection of another prespecified symbol (the probe). In two experiments, observers viewed lists of letters, identified a randomly selected letter as a target, and detected the presence of a probe from a different category (a digit or a Greek letter). After several days of training, probe detection following a target had improved markedly. Posttarget probe detection was again impaired when the distractor set included members of the probe set. These results are compatible with an explanation of the attentional blink as an act of suppression aimed at the current set of distractors, but additional mechanisms are needed to account for the effects of training.

Enricher reactor--permeable reactive biobarrier approach for removing a mixture of contaminants with substrate interactions.

A laboratory-scale enricher reactor (ER) - permeable reactive biobarrier (PRBB) system was studied to address performance loss of a PRBB due to substrate interactions among a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX) in groundwater, when the mixture reappeared after a 10-day absence period. Toluene and BTEX as an inducer in ER were compared to investigate toluene as a potential single inducer in ER. PRBBs without ER augmentation experienced performance losses ranging from 11% to 35% for PRBBs initially inoculated with toluene degraders and 22% to 33% for PRBBs initially inoculated with BTEX degraders. Bacterial communities changed substantially in these PRBBs after the absence period, which could contribute to the performance losses. PRBBs augmented with toluene degraders overcame the inhibition interaction between benzene and toluene, and showed a superior removal performance for toluene degradation suggesting that toluene can be used as a single inducer in an ER.

Three-step treadmill test and McKenzie mechanical diagnosis and therapy to establish directional preference in a patient with lumbar spinal stenosis: a case report.

BACKGROUND: Lumbar spinal stenosis (LSS) is defined as narrowing of the spinal canal. LSS is commonly treated conservatively, primarily with flexion-based exercises. We present a patient diagnosed with LSS, refractory to a flexion-based protocol who ultimately responded to an extension-based protocol following establishment of directional preference with three-step treadmill testing. DESCRIPTION: A 64-year-old male was diagnosed with LSS with a 2-year history of bilateral neurogenic claudication unresponsive to flexion-based exercises. Initially, distinct directional preference or centralization was not demonstrated on repetitive movement testing. Ultimately, preference towards extension was established through a three-step treadmill test. An extension-based treatment plan was recommended, which provided significant relief despite focusing on exercises that are commonly avoided during traditional treatment for LSS. OUTCOMES: He began to centralize pain to his lower back after 2 weeks and denied neurogenic claudication on repeat three-step treadmill test at 3 weeks. His drastic improvements in pain levels and functional status continued throughout four sessions. DISCUSSION: Although the patient's initial diagnostic label may bias towards a spinal flexion protocol, further mechanical testing revealed an extension directional preference. The three-step treadmill test was crucial in establishing his directional preference and guiding his treatment. Treadmill testing may be useful in a subset of patients who do not demonstrate distinct directional preferences on mechanical testing.