Copper transformation, speciation, and detoxification in anoxic and suboxic freshwater sediments.

The complex chemistry of copper (Cu) in freshwater sediments at low concentrations is not well understood. We evaluated the transformation processes of Cu added to freshwater sediments under suboxic and anoxic conditions. Freshwater sediments from three sources in Michigan with different characteristics (Spring Creek, River Raisin, and Maple Lake) were spiked with 30 or 60 mg kg-1 Cu and incubated under a nitrogen atmosphere. After 28-d, each treatment subset was amended with organic matter (OM) to promote anoxic conditions and evaluate its effects on Cu speciation. OM addition triggered a shift from suboxic to anoxic conditions, and sequential extractions showed that Cu accordingly shifted from acid-soluble to oxidizable fractions. Extended X-ray absorption fine-structure (EXAFS) spectroscopy revealed that Cu sulfides dominated all anoxic samples except for Spring Creek 30 mg kg-1, where Cu(I) was predominantly complexed to thiol groups of OM. Covellite and chalcopyrite (CuFeS2) were the predominant Cu species in nearly all anoxic samples, as determined by Raman spectroscopy, scanning electron microscopy, and X-ray absorption near-edge structure (XANES) spectroscopy. Copper reduction also occurred under suboxic conditions: for two of three sediments, around 80% had been reduced to Cu(I), while the remaining 20% persisted as Cu(II) complexed to OM. However, in the third coarsest (i.e., Spring Creek), around 50% of the Cu had been reduced, forming Cu(I)-OM complexes, while the remainder was Cu(II)-OM complexes. Toxicity tests showed that survival of H. azteca and D. magna were significantly lower in suboxic treatments. Anoxic sediments triggered a near-complete transformation of Cu to sulfide minerals, reducing its toxicity.

Tracking and Assessing Oil Spill Toxicity to Aquatic Organisms: A Novel Approach.

An in situ exposure and effects bioassay system was developed for assessing the toxicity of oil spills to aquatic organisms. The assessment tool combines components of 2 previously developed systems, the sediment ecotoxicity assessment ring (SEA Ring) and the drifting particle simulator. The integrated drifting exposure and effects assessment ring (DEEAR) is comprised of a Global Positioning System (GPS) float, a drifter drogue, the SEA Ring, and the Cyclops-7 fluorescent sensor. Polyethylene passive sampling devices (PED) were mounted for an additional means to characterize water quality conditions and exposures. The DEEAR is optimized for evaluating oil exposure and toxicity in the shallow surface mixing layer of marine waters. A short-term preliminary test was conducted in San Diego, California, USA, to verify the operation of the GPS tracking, the iridium communications, and the integrated SEA Ring exposure system. Further, a proof-of-concept demonstration was conducted offshore in the Santa Barbara Channel, where natural oil seeps produce surface slicks and sheens. Two DEEAR units were deployed for 24 h-one within the oil slick and one in an area outside observable slicks. An aerial drone provided tracking of the surface oil and optimal sites for deployment. The DEEAR proof-of-concept demonstrated integrated real-time tracking and characterization of oil exposures by grab samples, PED, and fluorescent sensors. Oil exposures were directly linked to toxic responses in fish and mysids. This novel integrated system shows promise for use in a variety of aquatic sites to more accurately determine in situ oil exposure and toxicity. Environ Toxicol Chem 2021;40:1452-1462. © 2021 SETAC.

Tracheal resection: the team brief in multi-stage airway surgery.

The multidisciplinary team brief and effective clinical decision-making are critical to airway surgery. To illustrate this, we present the case of a 58-year-old female with papillary thyroid cancer invading the trachea. We describe a basic framework that was used to aid planning the management of this patient. Tracheal resection is a complex airway operation requiring the evaluation of airway obstruction risk, the formulation of strategies for complex airway management and lung ventilation during complete resection of the tracheal segment and a handover plan for safe tracheal extubation. We suggest that team performance is facilitated by a standardised structure for consideration of anticipated events and important decisions to be made before the operation. Furthermore, it can provide a platform to engage the team when unanticipated events occur and alternate plans have to be made in a time-critical manner.

Influence of genetic and environmental factors in peripheral arterial disease natural history: Analysis from six years follow up.

BACKGROUND: Peripheral arterial disease (PAD) is a disease affecting million of patients worldwide. Though traditional cardiovascular risk factors have been associated with the development of PAD, the possible existence of an inherited genetic predisposition to PAD has been investigated in few familial aggregation studies. A link between genetics and PAD may open new avenues for the prevention of this morbid and mortal disorder. AIM: The aim of this study is to investigate a possible role of some genetic determinant involving into coagulation and homocysteine metabolism in the progression of PAD. MATERIALS AND METHODS: We follow one-hundred patients affected by PAD for six years. We evaluated Ankle-Brachial Index (ABI) two times; first at the time of recruitment and then after six years, in order to assess the progression of disease. Genotypes for the genes of Factor V Leiden, Prothrombin or Factor II G20210A, Cystathionine Beta-Synthase 844ins68bp and Methylenetetrahydrofolate Reductase C677T was ascertained after taking blood samples. Chi-square test was performed to determinate the possible correlation of these genes and the most common environmental factors in the progression of PAD. RESULTS: Genetic disorders resulting in high level of homocysteina or thrombophilic phenotype are not so frequent. None among the genetic factors we considered were correlated with PAD. CONCLUSION: PAD is a chronic disease whose course can be slowed down especially with the control of environmental risk factors. Genetic analyses are not useful to determine the disease progression or its tendency to remain stable.

[Surgical treatment of non-metastatic gastric GIST: two cases and review of the literature]. / Trattamento chirurgico dei GIST gastrici non metastatici: due casi significativi e revisione della letteratura.

Gastro-Intestinal Stromal Tumors (GISTs) represent an evolving field in oncological surgery and must be approached with specific prognostic and therapeutic criteria. In the GIST's suspicion the surgeon has to consider all the therapeutic possibilities, also for the impossibility to predict the biological behaviour and the aggressiveness of the tumor. The presence of a GIST has to be suspected in patients observed for gastrointestinal bleeding, when another pathology isn't demostrable. Surgical strategy must consider a limited resection as the best treatment, differently from what we do for adenocarcinoma. The extension of the resection can changes, regarding tumor volume and position, from extremely invasive surgery to laparoscopic operations with a partial removal of the gastric wall. Lymphadenectomy is not indicated because these tumors rarely spread to the nodes. We present the clinical case of two patients observed for gastrointestinal bleeding and with preoperative diagnostic suspicion of GIST, submitted to surgical resection. In the first case we performed a superior polar gastrectomy with esofago-gastric anastomosis for the mass proximity to the cardias. In the second patient the intervention has been a limited resection of the fundus of stomach including the tumor.

[A case of amputation neuroma of the bile duct following video-laparoscopic cholecystectomy]. / A proposito di un caso di neuroma d'amputazione della via biliare dopo colecistectomia laparoscopica.

We report a case of neuroma of the common hepatic duct arising five years after cholecystectomy (laparoscopic then converted in laparotomy). A 73-years-old patient was admitted for obstructive jaundice. Ultrasonography, TC and cholangiography showed a nodular lesion of the common hepatic of 1 cm in diameter, causing a regular and important stenosis of the main bile duct. Histologic examination demonstrated neuroma. By the analysis of this and 42 other previously published cases, the following features of bile duct neuroma were outlined: 1) variable interval between cholecystectomy and the onset of jaundice (2 months to 40 years); 2) the same incidence after laparoscopic or laparotomic cholecystectomy; 3) the generally complicated postoperative course after first surgical approach; 4) the various localizations on the biliary tree (cystic, main bile duct, intrahepatic ducts); 5) the circumstances of onset are almost the same (obstructive jaundice); 6) the histologic examination is mandatory for a correct diagnosis; and 7) the best treatment is resection of the bile duct tract involved in neuroma and reconstruction of biliary tree with hepaticojejunostomy.

[Results of elective open surgery for juxtarenal aortic aneurysms]. / I risultati del trattamento elettivo in open surgery degli aneurismi juxtarenali dell'aorta.

Review of the most significant surveys (data base: Pub Med on September 2003) of elective open surgery for Juxtarenal aneurysms and personal results of 106 cases (9.3% of AAA consecutively operated in the last 11 yrs.) are reported. Mortality and morbidity are discussed related to: technique of aortic cross-clamping; protective measures on splanchnic and renal perfusion; risks from previous CAD and chronic renal failure. Over all, the main predictive factor is the accuracy of the selected technique, without any difference among different approaches, and the same results of infrarenal aneurysms can be obtained.

Rectal localization of metastatic lobular breast cancer: report of a case.

The incidence of extrahepatic gastrointestinal metastases from breast cancer is reported in the literature only as necroscopy studies (6-18 percent); they usually originate from lobular or a mixed ductal-lobular subtype. Nonspecific presenting symptoms, death of the patients caused by other more frequent metastases, and variable radiographic features mimicking primary neoplasms cause a clinical underestimation of this pathology. We report here a case of rectal metastasis from a lobular carcinoma eight years after mastectomy.

Association of multiple granular cell tumors and squamous carcinoma of the esophagus: case report and review of the literature.

This report describes the case of a man who underwent subtotal esophagectomy for the concomitant presence of a multifocal esophageal squamous carcinoma and a granular cell tumor (GCT); he had been previously affected by another metachronous esophageal GCT excised endoscopically. This is the sixth case described in the literature detailing other cases of a combination of malignancies involving additional organs. We emphasize the need for a prolonged surveillance of patients with multiple GCTs in order to promptly recognize the possibility of associated neoplasms.

[Gastric metastasis from melanoma. Report of 2 surgically treated cases]. / Metastasi gastriche da melanoma. A proposito di due casi trattati chirurgicamente.

Metastatic disease involving the gastrointestinal tract is a rare pathology and melanoma is the extra-intestinal neoplasm more frequently concerned. Two cases of gastric metastases, revealed by symptoms of upper gastrointestinal bleeding, are reported. In the first case the disease-free interval, after excision of the primary lesion located in the right lower limb, was 13 years; in the second case the primary lesion remained unknown, although it probably originated from a giant congenital nevus of the left foot. Both patients had been affected before by inguinal nodes metastases, treated by radical groin lymphadenectomy; the concomitant multiple metastases to other sites (adrenal glands, retro-peritoneum, liver, lung, small bowel, brain, ovaries) limited surgery to a likely prospect of palliation, conditioning an unfavourable prognosis. Resection of gastrointestinal metastases is justified for the relief of intestinal hemorrhage (as in these reported cases), perforation and obstruction, even if treatment of single non-complicated lesions can have a curative intent. The conclusion is drawn that more aggressive diagnostic and staging procedures are indicated for the early detection of gastrointestinal metastases whenever non-specific abdominal symptoms and a history of melanoma are present.