Transport and dispersion of PFOA and PFOS in the Black Sea.

A 3-D transport and dispersion model was applied to study the recent past and future dynamics of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) concentrations in the Black Sea for the 2016-2030 period. The modelled surface concentrations show a distinct seasonal behaviour, shaped by winter to spring convective mixing. A significant increasing long-term trend in PFOS concentrations is established, with concentrations in water layers 200 m below the surface increasing at 4-8% per year. Driving mechanisms for PFOA and PFOS transport and accumulation in the subsurface and deeper layers are the cooling of the surface water in winter and the transport of water masses from the North Western Shelf (NWS) of the Black Sea. A simulated 50% phase-out of PFOA and PFOS from 2020 to 2030 shows a 21% reduction in PFOA, while PFOS continues to increase.

Should we reconsider how to assess eutrophication?

Eutrophication in marine waters is traditionally assessed by checking if nutrients, algal biomass and oxygen are below/above a given threshold. However, increased biomass, nutrient concentrations and oxygen demand do not lead to undesirable environmental effects if the flow of carbon/energy from primary producers toward high trophic levels is consistently preserved. Consequently, traditional indicators might provide a misleading assessment of the eutrophication risk. To avoid this, we propose to evaluate eutrophication by using a new index based on plankton trophic fluxes instead of biogeochemical concentrations. A preliminary, model-based, assessment suggests that this approach might give a substantially different picture of the eutrophication status of our seas, with potential consequences on marine ecosystem management. Given the difficulties to measure trophic fluxes in the field, the use of numerical simulations is recommended although the uncertainty associated with biogeochemical models inevitably affects the reliability of the index. However, given the effort currently in place to develop refined numerical tools describing the marine environment (Ocean Digital Twins), a reliable, model-based, eutrophication index could be operational in the near future.

Tracing water-soluble, persistent substances in the Black Sea.

We apply a tracer model linked with a 3D circulation model to simulate transport and fate of water-soluble persistent substances in the Black Sea that do not bioaccumulate to a considerable extent. The model uses specified degradation time and identical concentrations in the rivers to build a correlation between average concentration in the basin and half-life (DT50). The average concentration in certain sub-regions of the Black Sea can be estimated using an exponential dependence of DT50, if DT50 and concentration in rivers are known. Averaging is performed on the simulations from 2000 to 2019 with real atmospheric forcing and river runoff. A well-defined seasonal cycle is evident for the average shelf concentration, while the average concentration in the deep region does not show a pronounced seasonal cycle or inter-annual variations. With the help of the existing observational data, we estimate DT50 and concentration in the rivers for carbamazepine, sulfamethoxazole and terbuthylazine. Atrazine and simazine are believed to have accumulated in the basin for a long time due to their widespread use in the past and the slow rate of degradation in the marine environment.

Pathways and mixing of the north western river waters in the Black Sea.

Given the increasing role of river-borne anthropogenically-derived substances on the water quality of impacted marine ecosystems, it is important to study the pathways of the river waters in the Black Sea. We perform tracer simulations for the river-borne substance, aiming to track its transport and accumulation in the basin and to identify possible long term trends. Our results suggest a decrease in Danube plume transport southward along the coastline and increasing transport to the north and north-eastern parts of the North Western Shelf (NWS) and then to the southwest. Over the 1960-2017 period, the Black Sea circulation showed an amplification and consolidation of the Rim Current, most likely in response to climatic changes. Recent changes in the circulation patterns seem to be a key factor for the modification of the river plume pathways. The concentration of the river-borne substance reaches an annual maximum in September, when pulses with larger tracer concentrations can be found in the inner basin. The accumulation of river-borne substance on the north and south shelf has increased in recent decades.

Identifying distribution and accumulation patterns of floating marine debris in the Black Sea.

The distribution and accumulation of floating marine debris in the Black Sea during the last few decades are analysed by the help of numerical modelling. An approach based on a mesoscale circulation model combined with a particle tracking model is applied. It is established that the litter distribution is nearly independent of the source location and is mainly controlled by the basin circulation system. The western gyre predominantly accumulates floating debris in summer. After the integration of the main cyclonic current in winter, the debris in the inner basin moves east. Retention zones along the south-western coast persist in time. The mean particle stranding time is estimated at about 200 days. Accumulation zones along the south-eastern and eastern coast are abundant in summer, and then move further northeast and north. Simulations demonstrate an increasing litter accumulation in summer on the North Western Shelf and shelf break.

Black Sea thermohaline properties: Long-term trends and variations.

The current knowledge about spatial and temporal dynamics of the Black Sea's thermohaline structure is incomplete because of missing data and sparse distribution of existing measurements in space and time. This study presents 56 year continuous simulations of the Black Sea's hydrodynamics using the 3D General Estuarine Transport Model (GETM), without incorporating any relaxation toward climatological or observational data fields. This property of the model allows us to estimate independent temporal trends, in addition to resolving the spatial structure. The simulations suggest that the intermediate layer temperature is characterized by a weak positive trend (warming), whereas the surface temperature does not show a clear linear trend. Different salinity trends have been established at the surface (negative), upper (weaker negative) and main halocline (positive). Three distinct dynamic periods are identified (1960-1970, 1970-1995, 1995-2015), which exhibit pronounced changes in the Black Sea's thermohaline properties and basin circulation. Strengthening of the main cyclonic circulation, accompanied by intensification of the mesoscale anticyclonic eddy formation is found. Both events strongly affect the sea surface salinity but contribute in opposing directions. Specifically, strong composite large-scale circulation leads to an increase in sea surface salinity, while enhanced formation of mesoscale anticyclones decreases it. Salinity evolution with time is thus the result of the competition of these two opposing yet interdependent processes.

[The scientific information that the pharmaceutical industry provides to family doctors]. / La información científica que la industria farmacéutica proporciona a los médicos de familia.

OBJECTIVE: To check whether the information in the written publicity that the pharmaceutical industry gives to family doctors really is based on the scientific studies that support it. DESIGN: Cross-sectional study. SETTING: Health centre on the outskirts of a big city. PARTICIPANTS: Over a year, all the scientific studies that laboratory reps gave family doctors along with the advertising for medicines were collected. A total of 63 paired studies and advertising pieces were obtained. MAIN MEASUREMENTS: 1-3 advertising messages with each supporting study were selected and reviewed in a structured fashion. Then whether or not the messages selected were based on the study was appraised. RESULTS: 44.5% of the advertising messages were not based on the accompanying study; 29.9% clearly were based on the study; and in the rest there was a half-and-half relationship. There was a significant relationship between the evaluation of the advertising messages and the kind of study, masking and the kind of result variable. CONCLUSIONS: A high proportion of advertising messages are not based on the study that is reputed to support them. A critique of these studies has to be undertaken before the advertising messages can be looked at.

La información científica que la industria farmacéutica proporciona a los médicos de familia / The scientific information that the pharmaceutical industry provides to family doctors

Objetivo. Verificar si la información contenida en los soportes escritos que la industria farmacéutica entrega a los médicos de familia se deriva de los estudios científicos que la avalan. Diseño. Estudio transversal. Emplazamiento. Centro de salud de la periferia de una gran ciudad. Participantes. Durante un año se recogieron todos los estudios científicos que los representantes de laboratorios entregaron a los médicos de familia, junto con la publicidad de medicamentos adjunta. Se obtuvo un total de 63 parejas de estudios y soportes publicitarios. Mediciones principales. Se seleccionaron 1-3 mensajes publicitarios por cada soporte publicitario y se realizó una revisión estructurada por pares de los estudios correspondientes y sus características, para después valorar si los mensajes seleccionados se consideraban o no derivados del estudio. Resultados. El 44,5% de los mensajes publicitarios no se deriva del estudio que lo acompaña, el 29,9% se deriva claramente del estudio y en el resto aparece una relación intermedia. Se observa una relación significativa de la valoración de los mensajes publicitarios con el tipo de estudio, el enmascaramiento y el tipo de variable de resultado. Conclusiones. Gran proporción de mensajes publicitarios no se deriva del estudio que supuestamente los avala. Es necesario hacer una crítica de estos estudios antes de considerar los mensajes publicitarios

Objective. To check whether the information in the written publicity that the pharmaceutical industry gives to family doctors really is based on the scientific studies that support it. Design. Cross-sectional study. Setting. Health centre on the outskirts of a big city. Participants. Over a year, all the scientific studies that laboratory reps gave family doctors along with the advertising for medicines were collected. A total of 63 paired studies and advertising pieces were obtained. Main measurements. 1-3 advertising messages with each supporting study were selected and reviewed in a structured fashion. Then whether or not the messages selected were based on the study was appraised. Results. 44.5% of the advertising messages were not based on the accompanying study; 29.9% clearly were based on the study; and in the rest there was a half-and-half relationship. There was a significant relationship between the evaluation of the advertising messages and the kind of study, masking and the kind of result variable. Conclusions. A high proportion of advertising messages are not based on the study that is reputed to support them. A critique of these studies has to be undertaken before the advertising messages can be looked at

Enfermedad oportunista poco frecuente en enfermo con tratamiento inmunosupresor por artritis reumatoide / Rarely opportunistic disease in patient treated with immunosupresor therapy by rheumatoid arthritis

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Abdominal decompression plays a major role in early postparacentesis haemodynamic changes in cirrhotic patients with tense ascites.

BACKGROUND: Some cirrhotic patients with tense ascites who undergo paracentesis develop a circulatory dysfunction syndrome, manifested by an increase in plasma renin activity. Recently, a significant inverse correlation between postparacentesis changes in plasma renin activity and systemic vascular resistance has been demonstrated in these patients, suggesting that peripheral arterial vasodilatation could be responsible for this circulatory dysfunction, but the mechanisms by which tense ascites removal induces such changes are unknown AIM: To investigate the role of a decrease in intra-abdominal pressure (IAP) in the development of early postparacentesis haemodynamic changes METHODS: Eleven cirrhotic patients with tense ascites received a large volume paracentesis. A specially designed pneumatic girdle was used to compress the abdomen to avoid a decrease in IAP during ascites removal. Haemodynamic studies were performed before paracentesis, one hour after ascites flow stopped, and 30 minutes after pneumatic girdle deflation RESULTS: When IAP was maintained at its original level, no haemodynamic changes were observed, despite large volume paracentesis. However, a significant decrease in systemic vascular resistance was seen immediately after pneumatic girdle deflation CONCLUSIONS: Early haemodynamic changes after paracentesis are avoided if IAP is maintained at its original level. The abrupt decrease in IAP could be the trigger for the development of the initial haemodynamic changes that eventually produce postparacentesis circulatory dysfunction.

Diagnosis and percutaneous treatment of gastrointestinal hemorrhage. Long-term experience.

OBJECTIVE: to report our experience in the diagnosis and treatment of gastrointestinal hemorrhage. METHOD: from April 1987 to April 1997, 196 patients with gastrointestinal hemorrhage (134 men and 62 women) were studied. 165 (84%) were diagnosed as presenting upper gastrointestinal hemorrhage, and 31 (16%) presented lower gastrointestinal hemorrhage. The patients were studied with endoscopy and arteriography, and embolization was prescribed in 131 (67%). Patients with bleeding from esophageal varices were excluded from this study. RESULTS: a bleeding point was identified angiographically in 33% (n = 65) patients. 131 (67%) patients were treated with therapeutic embolization, which was successful in 89% (n = 116) patients. The bleeding was resolved in 80% (n = 93) of the patients. Complications included arterial spasm (n = 12), pain (n = 24), coil migration (n = 8), allergic reaction (n = 2) and celiac trunk dissection (n = 2). During follow-up 16 patients presented rebleeding that stopped after reembolization in 9 cases, whereas in 7 cases surgery was needed. CONCLUSIONS: in our experience, diagnostic angiography and percutaneous therapeutic embolization are effective, less aggressive methods that lead to few complications. Both methods have become indispensable tools in managing patients with gastrointestinal hemorrhage that does not respond to conservative therapy. Even in patients with no evidence of angiographic bleeding, embolization in selected patients is successful.

CO2 as a contrast medium in endoluminal treatment of high flow vascular malformations.

PURPOSE: To evaluate the diagnostic usefulness of CO2 as a radiologic contrast medium in pre and post-embolization of hemodynamically active vascular malformations. MATERIAL AND METHODS: Eight pre-and post-embolization angiographies were performed on five patients with hemodynamically active vascular malformations. In all cases sequentially iodinated contrast medium and CO2 were used. Procedures were performed using Philips Integris V equipped with specific software to process images obtained with CO2 as contrast medium and with a purpose-built gas injector pump. The images were assessed by three interventional radiologists who evaluated the findings by consensus. They were asked whether uptake of the malformations were better, worse or the same with iodinated contrast and CO2. The images were judged according to the following characteristics; quality, the filling in of the contrast in afferent artery of the HAVM, caliber and number of vessels and existence of pathologic communications in HAVM. These characteristics were assessed in all the patients of the study, both before and after embolization. RESULTS: The CO2 angiographic results were compared to those obtained using iodinated contrast material. Iodinated contrast provided superior image quality in all performed studies. The filling of arterial afference of HAVM was well defined with both contrast media. In all performed cases with CO2, the malformations showed more vessels. No inmediate nor subsequent complications developed with CO2 injections, except in one female patient, who presented an intense sensation of cramps in the lower limbs. CONCLUSION: CO2 is a useful diagnostic and assessment tool before and especially during the embolization of hemodynamically active vascular malformations. It improves quantification and uptake of the malformation's vascular architecture, detecting collateral circulation and arteriovenous shunts. It also detects residual post-embolization disease when iodinated contrast agent is unsuccessful.

Transcatheter embolization of symptomatic hepatic venous malformations.

The aim of this study was to evaluate our results in treatment and management of symptomatic hepatic venous malformations using transcatheter embolization therapy. From 1991 to 1997 five venous malformations were embolized in one man and four women ranging in age from 31 to 50 years. All patients presented nonspecific abdominal pain and were assessed in the general surgery unit. Percutaneous embolization was recommended. In all cases polyvinyl alcohol was used to embolize the afferent arterioles. Clinical and echographic control follow-up was carried out on an outpatient basis in our Vascular and Interventional Radiology Unit. Embolization was possible in all cases. No complications developed during the procedure, except in one case where the subject suffered a spasm of the hepatic artery. Mean follow-up time was 42 months (6-73 months). Four patients remained asymptomatic during the entire follow-up period, whereas one patient required reembolization. In our experience, transcatheter embolization of hepatic venous malformations is a noninvasive technique which requires few admissions and presents few complications. With further use, it could become the treatment of choice in symptomatic hepatic venous malformations as an alternative to surgery.

[Treatment of dysphagia of malignant origin with the endoprosthesis of Strecker]. / Tratamiento de la disfagia de origen maligno con endoprótesis de Strecker.

OBJECTIVE: To evaluate the effectiveness of metallic Strecker stents for palliation of malignant dysphagia. PATIENTS AND METHODS: From June 1992 to August 1995, 66 Strecker stents were inserted in 55 consecutive patients, 50 male and 5 female, with a mean age of 62 years (range 25-83). The cause of dysphagia was incurable malignant obstruction of the esophagus. Three patients presented with dysphagia grade I, 8 grade II, 27 grade III and 17 grade IV. All the procedures were performed under fluoroscopic control. RESULTS: Exact positioning of the stent was technically feasible in all patients. No procedure-related mortalities or major complications occurred. Immediate complications were transient chest pain (n = 11), blood stain sputum (n = 8) and gastroesophageal reflux (n = 8). During follow-up, 7 patients (12.7%) had recurrent dysphagia due to tumor ingrowth or overgrowth. In these patients an additional overlapping stent was successfully placed in six cases and balloon dilatation in one. Latest evaluation revealed dysphagia grade O in five patients (9%), 10 dysphagia grade I (18%), 14 grade II (25%), 13 grade III (23.6%) and seven grade IV. CONCLUSIONS: Implantation of Strecker stents is an effective and safe method of palliating severe malignant dysphagia. Placement of the stents was feasible without major procedure complications.

Intramuscular low flow vascular malformations: treatment by means of direct percutaneous embolization.

PURPOSE: Intramuscular hemodynamically inactive vascular malformations are infrequent entities whose surgical treatment is often impossible, crippling, or inefficient. We describe a nonsurgical therapeutic approach consisting on embolization by direct puncture with sclerosant substances. METHODS: Four patients have been treated from April to November 1994, three female and one male, ranging in age from 13 to 31 years. Three vascular malformations were located in the quadriceps and one in the deltoid muscle. The point of access was determined with information provided by MR. The skin was cleaned with an antiseptic solution and puncture was performed with a 22 gauge Chiva needle. Blood flow inside the malformation was slow in all cases and no afference to the normal venous system was detected. We embolized with 5-15 cc (mean 7.5 cc) of a mixture of ethibloc and ethanol. RESULTS: The mean follow-up period was 17 months (range 14-21). All patients remain asymptomatic and have resumed normal daily life activities. There were no complications. CONCLUSION: Percutaneous embolization by direct puncture of intramuscular vascular malformations is a feasible and simple procedure. Our preliminary results are promising, although more extensive studies need to be to performed in order to reach definite conclusions.

[Endovascular treatment of abdominal aorta aneurysms using bifurcated endoprosthesis]. / Tratamiento endovascular de los aneurismas de aorta abdominal con endoprótesis bifurcadas.

OBJECTIVE: To obtain an initial assessment of the implantation technique of bifurcated vascular endoprothesis in the treatment of abdominal aorta aneurysms (AAA). METHODS: Eleven Vanguard type endoprostheses were implanted in eleven patients with infra-renal aortic aneurysm. The technique was performed with surgical approach in one femoral artery, and percutaneously in the other. The procedure was performed with epidural anesthesia. RESULTS: A technical success--i.e., the exclusion of the aneurysm--was obtained in all cases. No technical complications occurred during the procedure. Three patients had low degree contrast leak in the angiographic control immediately after the procedure. Eight patients had low grade fever in the immediate follow-up which resolved with medical therapy, two patients had hematomas in the approach sites, one renal infarction, one ileus for two days, another one for five days, and three patients had lymphatic effusion. During follow-up the patients with leak had to undergo co-axial endoprosthesis implantation. CONCLUSIONS: It is our view that bifurcated vascular endoprostheses offer a valid alternative in the treatment of AAA. The procedure can be performed with epidural anesthesia and sedation, with a low rate of complications. The long term follow-up and the perfecting of the approach and resection systems will ultimately dictate their usefulness in this and other vascular conditions.

Treatment of complete and partial obstruction of the nasolacrimal system with polyurethane stents: initial experience.

PURPOSE: To present our experience in the treatment of nasolacrimal occlusion by means of polyurethane stents. METHODS: Forty polyurethane stents were placed under fluoroscopic guidance in 35 consecutive patients with epiphora due to total or partial obstruction of the nasolacrimal system. The set designed by Song was used in all patients. The procedure was performed by introducing a guidewire through the superior punctum into the canaliculus and advancing it across the obstruction into the inferior meatus of the nasal cavity. After pulling out the guidewire, the stent was advanced in retrograde fashion and released into the sac and the nasolacrimal duct. RESULTS: The technical success rate was 100%. The average time for the procedure was 25 min (range 10-60 min). Immediate complications were: mild pain (n = 5), severe pain (n = 1), minimal epistaxis (n = 7), and moderate epistaxis (n = 1). No major complications occurred. The last clinical control revealed complete resolution of epiphora in 35 eyes and partial resolution in four; one patient did not improve. CONCLUSION: This technique for treatment of obstruction of the nasolacrimal system is simple and safe, and may obviate the use of more invasive procedures.

Treatment of chronic iliac artery occlusions with guide wire recanalization and primary stent placement.

PURPOSE: To evaluate the results of primary stent placement without initial thrombolysis in the treatment of iliac occlusions. MATERIALS AND METHODS: During a 3-year period, 61 iliac artery occlusions were treated in 59 patients. The mean length of the occluded segment was 10 cm (range, 4-25 cm). The occluded arteries were treated with primary placement of self-expandable metallic stents. RESULTS: Successful recanalization with primary stent placement was possible in 56 of 61 occlusions (92% technical success rate). Mean Doppler ankle/brachial index increased from 0.51 to 0.90 immediately after treatment and was 0.91 on the last follow-up (P < .05). Primary patency rate at 24 months was 73%, and secondary patency rate was 88%. Procedural complications included distal embolization (n = 4) and an episode of massive intra-abdominal bleeding. Three patients developed a hematoma at the puncture site that did not require additional therapy. Late complications included stent occlusion (n = 9) and significant stenosis related to intimal hyperplasia (n = 1). Mean follow-up period was 29 months (range, 7-55 months). CONCLUSION: Primary stent placement is an effective therapeutic option for iliac artery occlusions.

Cragg Endopro System I: early experience. I. Femoral arteries.

PURPOSE: This work describes the early experience with the Cragg Endopro System I. The safety and efficacy of this device in the treatment of atherosclerotic lesions of the femoral arteries are evaluated. MATERIALS AND METHODS: Eleven patients with complex femoral artery lesions were treated. Ten patients presented with femoral artery occlusion and one had a 90% stenosis. All patients had life-style limiting claudication. Associated comorbid states included smoking (n = 10), hypertension (n = 4), hyperlipidemia (n = 5), coronary artery disease (n = 3), and diabetes (n = 1). The stents were dilated to the size of the native artery in the first three patients. The protocol was modified and stents were overdilated by 1 mm in the remaining eight patients. An anticoagulation regimen was used in the first three patients and modified per protocol requirements in the remaining eight. Prophylactics antibiotics were given before the procedure. Follow-up studies included Doppler ultrasound and intravenous and intraarterial digital subtraction angiography. RESULTS: An antegrade femoral approach was used. Stent placement was successful in all patients. The mean lesion length was 9.9 cm (4-18 cm). Mean ankle/brachial index before treatment was 0.65 and increased to 0.87 after treatment. Mean follow-up was 17.2 months, and one patients was lost to follow-up. Complications included sepsis (n = 1), fever (n = 2), severe pain (n = 4), thrombosis (n = 5), and hematoma (n = 2). Stent patency was improved after protocol modifications. Overall primary patency rate was 45% and secondary patency was 56%. CONCLUSION: This early experience with the Cragg Endopro System I shows that recanalization of long femoral occlusions and stent-graft placement is feasible. The primary and secondary patency rates are low and the complication rate is high. Improved patency rates are expected with a more aggressive anticoagulation regimen and stent overdilation.