Characterization of an undocumented CO2 hydrothermal vent system in the Mediterranean Sea: Implications for ocean acidification forecasting.

A previously undocumented shallow water hydrothermal field from Sicily (Southern Tyrrhenian Sea, Italy) is here described, based on a multidisciplinary investigation. The field, covering an area of nearly 8000 m2 and a depth from the surface to -5 m, was explored in June 2021 to characterise the main physico-chemical features of the water column, describe the bottom topography and features, and identify the main megabenthic and nektonic species. Twenty sites were investigated to characterise the carbonate system. Values of pH ranged between 7.84 and 8.04, ΩCa between 3.68 and 5.24 and ΩAr from 2.41 to 3.44. Geochemical analyses of hydrothermal gases revealed a dominance of CO2 (98.1%) together with small amounts of oxygen and reactive gases. Helium isotope ratios (R/Ra = 2.51) and δ13CCO2 suggest an inorganic origin of hydrothermal degassing of CO2 and the ascent of heat and deep-seated magmatic fluids to the surface. Visual census of fishes and megabenthos (mainly sessile organisms) allowed the identification of 64 species, four of which are protected by the SPA/BIO Protocol and two by the International Union for Conservation of Nature. The macroalgae Halopteris scoparia and Jania rubens and the sponge Sarcotragus sp. were the dominant taxa in the area, while among fishes Coris julis and Chromis chromis were the most abundant species. This preliminary investigation of San Giorgio vent field suggests that the site could be of interest and suitable for future experimental studies of ocean acidification.

How typhoons trigger turbidity currents in submarine canyons.

Intense turbidity currents occur in the Malaylay Submarine Canyon off the northern coast of Mindoro Island in the Philippines. They start in very shallow waters at the shelf break and reach deeper waters where a gas pipeline is located. The pipeline was displaced by a turbidity current in 2006 and its rock berm damaged by another 10 years later. Here we propose that they are triggered near the mouth of the Malaylay and Baco rivers by direct sediment resuspension in the shallow shelf and transport to the canyon heads by typhoon-induced waves and currents. We show these rivers are unlikely to generate hyperpycnal flows and trigger turbidity currents by themselves. Characteristic signatures of turbidity currents, in the form of bed shear stress obtained by numerical simulations, match observed erosion/deposition and rock berm damage patterns recorded by repeat bathymetric surveys before and after typhoon Nock-ten in December 2016. Our analysis predicts a larger turbidity current triggered by typhoon Durian in 2006; and reveals the reason for the lack of any significant turbidity current associated with typhoon Melor in December 2015. Key factors to assess turbidity current initiation are typhoon proximity, strength, and synchronicity of typhoon induced waves and currents. Using data from a 66-year hindcast we estimate a ~8-year return period of typhoons with capacity to trigger large turbidity currents.

The role of ultrasound of sentinel nodes in the pre- and post-operative evaluation of stage I melanoma patients.

We have investigated the role of high-resolution ultrasound (US) in the analysis of sentinel node(s) in melanoma patients in pre-operative staging and follow-up. One hundred and six lymph node basins in 88 melanoma patients undergoing sentinel node biopsy (SNB) were examined: 25 (23.6%) were US positive for metastases and 81 (76.4%) were negative. Subsequent histological analysis of the 81 negative lymph nodes confirmed the absence of metastases in 80 cases (98.8%), whereas, in the 25 US-positive lymph nodes, metastases were found in 16 cases (64%). The follow-up of all patients submitted to SNB in our unit included a US investigation of operated and contralateral nodal basins every 4 months for the first 3 years and then every 6 months. Of a total of 300 patients, four (1.6%) were found to have locoregional nodal disease during follow-up. In three of these four patients, US was crucial in indicating the presence of nodal metastases, which would have gone undetected on physical examination. The result of this study (negative predictive value of 98.7%) introduces the possibility of selecting patients who may avoid an SNB procedure based on the results of pre-operative US examination.

Drugs and Rhabdomyolysis: From Liver to Kidney.

Rhabdomyolysis is a syndrome due to a damage of skeletal muscle and the leakage of intracellular contents into the extracellular fluid and the circulation. Several causes may induce rhabdomyolysis and the major one is the crush syndrome. Most cases of non-traumatic rhabdomyolysis are related to drugs. Many molecules are subject to hepatic metabolism and the concomitant use of drugs, as statins, with other medications acting as substrates of the same isoenzymes can interact and increase the risk of myopathy. Subclinical rise of creatine kinase may be the expression of rhabdomyolysis that can present as a medical emergency such as acute kidney injury (AKI), compartment syndrome, cardiac dysrhythmias and disseminated intravascular coagulopathy. The main pathophysiological mechanisms of myoglobinuric-related AKI are renal vasoconstriction, formation of intraluminal casts and direct cytotoxicity promoted by heme-protein. The aim of this review is to analyze the pathophysiology of myolysis, the causes of rhabdomyolysis and especially the link between the liver and the kidney, which can represent the connecting element for the development of the syndrome.

Primary and recurrent retroperitoneal soft tissue sarcoma: prognostic factors affecting survival.

BACKGROUND AND OBJECTIVES: To analyze treatment and survival in 34 patients (28 resected) with primary or recurrent retroperitoneal sarcoma (RPS). METHODS: Between July 1994 and January 2001, 34 patients (15M, 19F; mean age: 56 years, range: 25-77) were evaluated. Complete resection was defined as removal of gross tumor with histologically confirmed clear resection margins. RESULTS: Twenty-eight out of 34 patients (82%) (15 were affected by primary RPS, and 13 by recurrent RPS), underwent surgical exploration. Twenty-three patients had a grossly and microscopically complete resection, (3 having a grossly incomplete resection and 2 patients with a grossly complete resection having histologically involved resection margins). Twenty-one out of 28 patients (75%) underwent removal of contiguous intra-abdominal organs. Preoperative mortality was nil, and morbidity occurred in six cases only (21%). High tumor grade results a significant variable for a worse survival in all 28 patients (100% 5 years survival for low grade vs. 0% for high grade; P = 0.0004). Amongst completely resected patients, only histologic grade and peroperative blood transfusions affected disease-free survival (P = 0.04 and P = 0.05, respectively). CONCLUSIONS: An aggressive surgical approach in both primary and recurrent RPS is associated with long-term survival.

Pulsed dose-rate perioperative interstitial brachytherapy for soft tissue sarcomas of the extremities and skeletal muscles of the trunk.

BACKGROUND: This study evaluated the role of pulsed dose-rate (PDR) brachytherapy (BRT), delivered alone or as a boost to external beam radiotherapy, as adjuvant therapy for the local control of soft tissue sarcomas of the extremities and skeletal muscles of the trunk that have undergone surgical treatment. METHODS: Between July 1998 and January 2002, 42 patients were treated with a combination of surgery and BRT alone (18 patients) or BRT/external beam radiotherapy (24 patients) for the treatment of primary (n = 32) and recurrent (n = 10) soft tissue sarcomas located in the proximal extremity (n = 17), distal extremity (n = 17), and trunk (n = 8). Tumor size was <5 cm in 20 cases and >5 cm in 22 cases, with histological grading of 1 (n = 7), 2 (n = 18), or 3 (n = 17). The median BRT dose delivered was 15 Gy, and the median external beam irradiation dose was 50 Gy. RESULTS: With a median follow-up of 34 months, the 36-month survival was 83.9% (SE, 6.1%), and the local control was 89%. CONCLUSIONS: PDR interstitial BRT for soft tissue sarcoma is an effective, well-tolerated adjuvant radiation treatment that offers several practical advantages, among which are low acute and late toxicity with maximum normal tissue and critical structure sparing and overall shorter radiotherapy and hospital stay.