Assessing the fate of brown trout (Salmo trutta) environmental DNA in a natural stream using a sensitive and specific dual-labelled probe.

Environmental DNA (eDNA) analysis in the aquatic environment has emerged as a promising tool for diagnosis of the ecological status in comprehensive monitoring strategies and might become useful in context of the European Water Framework Directive (WFD) and other legislations to derive stressor-specific indicators. Despite many studies having made significant progress for the future use of eDNA in terms of ecosystem composition and detection of invasive/rare species in inland waters, much remains unknown about the transport and fate of eDNA under natural environmental conditions. We designed a specific dual-labelled probe to detect brown trout (Salmo trutta, L.) eDNA and used the probe to describe the fate of eDNA released from an aquaculture facility into the low mountain range stream Wehebach, Germany. The probe was shown to be specific to brown trout, as ponds housing rainbow trout (Oncorhynchus mykiss) did not test positive. Even though we observed different strengths of eDNA signals for three ponds containing different brown trout quantities, no significant correlation was found between biomass (kg/L) and eDNA quantity. Our results indicate that the release of DNA from brown trout might be life stage and/or age-dependent. The effluents of the aquaculture facility were a source of high levels of eDNA which resulted in the greatest abundance of brown trout eDNA directly downstream of the facility. Despite the natural occurrence of brown trout in the Wehebach, as shown by ecological investigations conducted by authorities of the federal state of North Rhine-Westphalia (Germany) and personal observations, we observed a significant decrease of relative abundance of eDNA in the Wehebach within the first 1.5 km downstream of the aquaculture. Our results suggest that concentrations of eDNA in running waters rapidly decrease under natural conditions due to dilution and degradation processes, which might have important implications for the utility of eDNA in environmental research.

Endoscopic papillectomy: data of a prospective observational study.

AIM: To investigate the clinical value of endoscopic papillectomy indicated by feasibility and safety of the procedure in various diseases of the papilla in a representative number of patients in a setting of daily clinical and endoscopic practice and care by means of a systematic prospective observational study. METHODS: Through a defined time period, all consecutive patients with tumor-like lesions of the papilla, who were considered for papillectomy, were enrolled in this systematic bicenter prospective observational study, and subdivided into 4 groups according to endoscopic and endoscopic ultrasonography (EUS) findings as well as histopathological diagnosis: adenoma; carcinoma/neuroendocrine tumor (NET)/lymphoma; papilla into which catheter can not be introduced; adenomyomatosis, respectively. Treatment results and outcome were characterized by R0 resection, complication, recurrence rates and tumor-free survival. RESULTS: Over a 7-year period, 58 patients underwent endoscopic papillectomy. Main symptoms prompting to diagnostic measures were unclear abdominal pain in 50% and cholestasis with and without pain in 44%. Overall, 54/58 patients [inclusion rate, 93.1%; sex ratio, males/females = 25/29 (1:1.16); mean age, 65 (range, 22-88) years] were enrolled in the study. Prior to papillectomy, EUS was performed in 79.6% (n = 43/54). Group 1 (adenoma, n = 24/54; 44.4%): 91.6% (n = 22/24) with R0 resection; tumor-free survival after a mean of 18.5 mo, 86.4% (n = 19/22); recurrence, 13.6% (n = 3/22); minor complications, 12.5% (n = 3/24). Group 2 (carcinoma/NET/lymphoma, n = 18/54; 33.3%): 75.0% (n = 10/18) with R0 resection; tumor-free survival after a mean of 18.5 (range, 1-84) mo, 88.9% (n = 8/9); recurrence, 11.1% (n = 1/9). Group 3 (adenomyomatosis, n = 4/54; 7.4%). Group 4 (primarily no introducible catheter into the papilla, n = 8; 14.8%). The overall complication rate was 18.5% (n = 10/54; 1 subject with 2 complications): Bleeding, n = 3; pancreatitis, n = 7; perforation, n = 1 (intervention-related mortality, 0%). In summary, EUS is a sufficient diagnostic tool to preoperatively clarify diseases of the papilla including suspicious tumor stage in conjunction with postinterventional histopathological investigation of a specimen. Endoscopic papillectomy with curative intention is a feasible and safe approach to treat adenomas of the papilla. In high-risk patients with carcinoma of the papilla with no hints of deep infiltrating tumor growth, endoscopic papillectomy can be considered a reasonable treatment option with low risk and an approximately 80% probability of no recurrence if an R0 resection can be achieved. In patients with jaundice and in case the catheter can not be introduced into the papilla, papillectomy may help to get access to the bile duct. CONCLUSION: Endoscopic papillectomy is a challenging interventional approach but a suitable patient- and local finding-adapted diagnostic and therapeutic tool with adequate risk-benefit ratio in experienced hands.

Precipitated silica as flow regulator.

Flow regulators are added to solid pharmaceutical formulations to improve the flow properties of the powder mixtures. The primary particles of the flow regulators exist in the form of huge agglomerates which are broken down into smaller aggregates during the blending process. These smaller aggregates adsorb at the surface of the solid's grains and thus diminish attractive Van-der-Waals-forces by increasing the roughness of the host's surface. In most cases amorphous silica is used as flow additive but material properties like particle size or bond strength influence the desagglomeration tendency of the agglomerates and thus the flow regulating potency of each silica. For some silica types we will show that the differences in their flow regulating potency are due to the rate and extent by which they are able to cover the surface of the host particles. Binary powder mixtures consisting of a pharmaceutical excipient and an added flow regulator were blended in a Turbula mixer for a defined period of time. As pharmaceutical excipient corn starch was used. The flow regulators were represented by a selection of amorphous silicon dioxide types like a commercial fumed silica and various types of SIPERNAT precipitated silica provided by Evonik-Degussa GmbH, Hanau, Germany. Flowability parameters of the mixtures were characterized by means of a tensile strength tester. The reduction of tensile strength with the blending time can be correlated with an increase in fragmentation of the flow regulator.

Slide-based cytometry for predicting malignancy in solid salivary gland tumors by fine needle aspirate biopsies.

BACKGROUND: To minimize hospitalization and morbidity for a patient with a solid tumor of a salivary gland, malignancy must be confirmed or excluded as soon as possible. This information cannot be obtained preoperatively by existing standard procedures. Minimal-invasive approaches with adequate diagnostic analysis represent a promising precondition for optimized therapy. METHODS: For fine needle aspirate biopsies (FNABs), laser scanning cytometry (LSC) offers a semi-automated slide-based technology for objective and quantitative analysis. We have established an assay for FNABs from salivary gland tumors. FNAB cells were stained for cytokeratin and DNA followed by LSC analysis. The cells were subsequently HE-stained and were relocalized on the slide. The LSC analysis quantitatively determines the DNA index (DI) of the tumor cells taking leukocytes as internal DNA diploid standard. Histograms with 0.95 < DI < 1.05 and 1.9 2.5 (i.e., 5c exceeding rate, 5cER) was calculated. Samples with DNA aneuploid peaks or with 5cER > 5% were classified as malignant. Routine histopathology was performed as a control. RESULTS: FNABs from 51 solid salivary gland tumors (41 parotid gland, six submandibular, four parapharyngeal) were analyzed with this assay. Eleven of 14 malignant tumors were DNA aneuploid by LSC analysis. All benign tumors showed diploid DNA content. The positive predictive value for malignancy was 1.0, the negative predictive value was 0.93, the correlation with routine histopathology was highly significant (p = 7.6 x 10(-9), Fisher's exact test). The calculated specificity of LSC analysis was 1.0 and the sensitivity was 0.79. CONCLUSIONS: This pilot study demonstrates the validity of slide-based cytometry for the preoperative prediction of malignancy in solid tumors being inaccessible for incision biopsy but suitable for FNABs such as those of the parotid gland.