Varying attenuation of trace organic chemicals in natural treatment systems - A review of key influential factors

The removal of trace organic chemicals (TOrCs) from treated wastewater and impacted surface water through managed aquifer recharge (MAR) has been extensively studied under a variety of water quality and operating conditions and at various experimental scales. The primary mechanism thought to dictate removal over the long term is biodegradation by microorganisms present in the system. This review of removal percentages observed in biologically active filtration systems reported in the peer-reviewed literature may serve as the basis to identify future indicators for persistence, as well as variable and efficient removal in MAR systems. A noticeable variation in reported removal percentages (standard deviation above 30%) was observed for 24 of the 49 most commonly studied TOrCs. Such variations suggest a rather inconsistent capacity of biologically active filter systems to remove these TOrCs. Therefore, operational parameters such as the change in dissolved organic carbon (ΔDOC) during treatment, hydraulic retention time (HRT), filter material, and redox conditions were correlated to the associated TOrC removal percentages to determine whether a data-based relationship could be elucidated. Interestingly, 11 out of the 24 compounds demonstrated increased removal with increasing ΔDOC concentrations. Furthermore, 10 compounds exhibited a positive correlation with HRT. Based on the evaluated data, a minimum HRT of 0.5-1 day is recommended for removal of most compounds.

Fresh Ideas Bloom in Gut Healthcare to Cross-Fertilize Lake Management

Harmful bacteria may be the most significant threat to human gut and lake ecosystem health, and they are often managed using similar tools, like poisoning with antibiotics or algicides. Out-of-the-box thinking in human microbiome engineering is leading to novel methods, like engineering bacteria to kill pathogens, "persuade" them not to produce toxins, or "mop up" their toxins. The bacterial agent can be given a competitive edge via an exclusive nutrient, and they can be engineered to commit suicide once their work is done. Viruses can kill pathogens with specific DNA sequences or knock out their antibiotic resistance genes using CRISPR technology. Some of these ideas may work for lakes. We critically review novel methods for managing harmful bacteria in the gut from the perspective of managing toxic cyanobacteria in lakes, and discuss practical aspects such as modifying bacteria using genetic engineering or directed evolution, mass culturing and controlling the agents. A key knowledge gap is in the ecology of strains, like toxigenic vs nontoxigenic Microcystis, including allelopathic and Black Queen interactions. Some of the "gut methods" may have future potential for lakes, but there presently is no substitute for established management approaches, including reducing N and P nutrient inputs, and mitigating climate change.

[Sonographically guided, minimally invasive biopsy of uncertain mammary lesions. Clinical experience with a new biopsy system]

METHODS

We performed Vacora biopsy on 53 patients for minimally invasive breast diagnostics. Each histologically malignant lesion underwent surgery. The histopathology of the Vacora biopsy was then compared to the surgical report. When there was a discrepancy between Vacora histopathology and the report, the patient underwent open biopsy. In all patients with benign histopathology results, sonography was performed 5-7 days after biopsy and after 3 months.

RESULTS

We performed biopsies on two lesions in eight patients, and on three lesions in one patient. Mean age of the patients was 52.1+/-12.8 years. A total of 62 lesions were examined. Mean size of the lesions was 13.3+/-9.6 mm. Fourteen (26.4%) were malignant (n=2 DCIS, n=12 invasive carcinoma). Histological grading was identical for Vacora biopsy and the surgical specimens. One case showed ADH by Vacora biopsy, which was confirmed by open biopsy. Vacora biopsy generated one false negative. There were a total of 36 benign lesions.

CONCLUSION

Vacora biopsy under sonographic guidance is a method which is easy to handle, diagnostically accurate and without severe complications. Due to higher costs in comparison to high speed core biopsy, Vacora biopsy should be performed only in cases in which high speed core biopsy is not expected to result in a valid result.

[O-twist marker for post-interventional marking in imaging of suspected breast lesions]

AIM

The aim of this study was to develop a marker clip for use in minimally invasive diagnostics of breast cancer that can be placed and visualized during ultrasonography, mammography, and magnetic resonance imaging.

METHODS

The newly developed O-twist marker consists of three 0.15-mm biocompatible nitinol wires twisted together to form rings with a diameter of 2.5 mm. These are inserted elongated into a 20G cannula. The marker is ejected into the tissue through a mandrin and reverts to its predetermined ring form.

RESULTS

The multiple curves of the surface render the marker highly visible. Its geometry permits secure anchorage even in larger biopsy cavities and additionally prevents migration within the tissue.

CONCLUSION

The O-twist marker is applicable for all examination modalities and biopsy needles or biopsy systems and represents an important development for breast cancer diagnostics.

RFA von Tumoren des Knochens und der Weichteile

Radiofrequency ablation (RFA) of primary and secondary liver malignancies is a promising and rapidly evolving technique, which increasingly gains importance. A new field of RFA is the minimal invasive therapy of osseous and soft tissue tumors. In the management of osteoid-osteoma, RFA is a well established treatment option. Basic principles, indications, complications and results of RFA will be presented. A careful evaluation of indications for RFA in osseous or soft tissue neoplasms is mandatory. In patients who are neither candidates for surgical tumor resection nor respond to chemotherapy, there is a need for alternative treatment options. In these preselected patients a substantial improvement in quality of life with low associated morbidity can be provided by RFA. In malignancies of bone and soft-tissue tumors, RFA is a palliative treatment option. Therefore, the results can not be compared to those of surgical resection or chemotherapy which essentially are employed with curative intention. Our own experiences as well as data published in the literature indicate that RFA is a helpful tool in preserving patient's quality of life. The high technical and clinical success together with a low complication rate makes RFA of osseous and soft tissue neoplasms a valuable supportive tool for patients not referable for surgery or systemic therapy.

[Imaging of neuroendocrine tumors of the pancreas]

OBJECTIVE

To compare the value of the various imaging modalities in the detection of pancreatic islet cell tumors.

METHODS

Analysis of the literature to compare the value of ultrasound, CT, MRI, angiography, venous sampling, scintigraphy and PET in the detection of neuroendocrine tumors of the pancreas.

RESULTS

For transabdominal ultrasound a sensitivity of 60% has been reported; for endoscopic ultrasound a sensitivity of more than 90%. MRI with a sensitivity of 75-100% is more sensitive compared to CT with a sensitivity of 64-82%. Angiography and venous sampling have a reported sensitivity of 66% and 76%. Somatostatin receptor scintigraphy has a sensitivity of 81-88% with significant differences between the various histological subtypes of the pancreatic islet cell tumors. PET does not play an important role in the detection of neuroendocrine tumors of the pancreas.

CONCLUSION

None of the various modalities is superior alone, so that it is often necessary to combine them for diagnostic imaging of pancreatic islet cell tumors.

[Diagnostic evaluation of pancreatic carcinoma prompting treatment decisions]

An early diagnosis or even sufficient screening tools may allow improved and/or more successful treatment strategies for pancreatic carcinomas. Presently,we have no useful screening tools available. The 5 year survival rates of those suffering from pancreatic cancer is around 3%, with only 15% of patients at diagnosis available for curative resection protocols. Thus, better diagnostic procedures for populations at risk are urgently required. Today,endosonography complements new CT and MRI tests. High resolution CT and contrast enhanced MRI procedures are rapidly evolving and may offer more precise diagnostic opportunities. PET tests help discriminating benign from neoplastic tumors, and new molecular markers may offer the opportunity to screen patients at risk with the hope for an early diagnosis. Nevertheless, the technical progress made in tomographic procedures is developing so rapidly that comparative studies are often outdated at publication. Therefore,we have reason to hope for improved diagnostic skills, but presently have only limited data for the new techniques currently available.