Defining the Tipping Point in Surgical Performance for Laparoscopic Donor Nephrectomy Among Transplant Surgery Fellows: A Risk-Adjusted Cumulative Summation Learning Curve Analysis.

The United Network for Organ Sharing recommends that fellowship-trained surgeons participate in 15 laparoscopic donor nephrectomy (LDN) procedures to be considered proficient. The American Society of Transplant Surgeons (ASTS) mandates 12 LDNs during an abdominal transplant surgery fellowship. We performed a retrospective intraoperative case analysis to create a risk-adjusted cumulative summation (RACUSUM) model to assess the learning curve of novice transplant surgery fellows (TSFs). Between January 2000 and December 2014, 30 novice TSFs participated in the organ procurement rotation of our ASTS-approved abdominal transplant surgery fellowship. Measures of surgical performance included intraoperative time, estimated blood loss, and incidence of intraoperative complications. The performance of senior TSFs was used to benchmark novice TSF performance. Scores were tabulated in a learning curve model, adjusting for case complexity and prior TSF case volume. Rates of adverse surgical events were significantly higher for novice TSFs than for senior TSFs. In univariable analysis, multiple renal arteries, high BMI, prior abdominal surgery, male donor, and nephrolithiasis were correlated with higher incidence of adverse surgical events. Based on the RACUSUM model, high intraoperative time is mitigated after 28 procedures, incidence of intraoperative complications tends to diminish after 24 procedures, and improvement in estimated blood loss did not remain consistent. TSFs exhibit a tipping point in LDN performance by 24-28 cases and proficiency by 35-38 cases.

Bladder cancer in Spain 2011: population based study.

PURPOSE: We estimate the annual incidence of bladder cancer in Spain and describe the clinical profile of patients with bladder cancer enrolled in a population based study. MATERIALS AND METHODS: Using the structure of the Spanish National Health System as a basis, in 2011 the AEU (Spanish Association of Urology) conducted this study with a representative sample from 26 public hospitals and a reference population of 10,146,534 inhabitants, comprising 21.5% of the Spanish population. RESULTS: A total of 4,285 episodes of bladder cancer were diagnosed, of which 2,476 (57.8%) were new cases and 1,809 (42.2%) were cases of recurrence, representing an estimated 11,539 new diagnoses annually in Spain. The incidence of bladder cancer in Spain, age adjusted to the standard European population, was 20.08 cases per 100,000 inhabitants (95% CI 13.9, 26.3). Of patients diagnosed with a first episode of bladder cancer 84.3% were male, generally older than 59 years (81.7%) with a mean ± SD age of 70.5 ± 11.4 years. Of these patients 87.5% presented with some type of clinical symptom, with macroscopic hematuria (90.8%) being the most commonly detected. The majority of primary tumors were nonmuscle invasive (76.7%) but included a high proportion of high grade tumors (43.7%). According to the ISUP (International Society of Urologic Pathology)/WHO (2004) classification 51.1% was papillary high grade carcinoma. Carcinoma in situ was found in 2.2% of primary and 5.8% of recurrent cases. CONCLUSIONS: The incidence of bladder cancer in Spain, age adjusted to the standard European population, confirms that Spain has one of the highest incidences in Europe. Most primary nonmuscle invasive bladder cancer corresponded to high risk patients but with a low detected incidence of carcinoma in situ.

Evaluation of novel nystatin nanoemulsion for skin candidosis infections.

One of the most common fungal skin infections is candidosis. Topical application of drugs at the pathological sites offers potential advantage of direct drug delivery to the site of action. The main aim of this work was to evaluate an optimal nystatin nanoemulsion for topical application avoiding undesirable side effects as systemic absorption and toxicity. Surface morphology and droplet size distribution of nystatin nanoemulsion was determined by transmission electronic microscopy and dynamic light scattering. Vertical diffusion Franz-type cells and high-performance liquid chromatography were used to perform the in vitro release and ex vivo human skin permeation studies. Transdermal permeation parameters were estimated from the permeation values using different theoretical approaches. Microbiological studies were performed to evaluate the antifungal effect. Nanoemulsion exhibited a spherical shape with smooth surface and mean droplet size between 70 and 80 nm. The pharmacokinetic release showed the nanoemulsion is faster than commercial ointment Mycostatin(®) improving the potential therapeutic index. Permeation studies demonstrated nystatin was not absorbed into systemic circulation and the retained amount in the skin was sufficient to ensure an antifungal effect. This antifungal effect was higher for nystatin loaded nanoemulsion than nystatin itself. A therapeutic improvement of the nystatin nanoemulsion treatment compared with the classical ones was achieved.

Seagrass soils sequester up to half the metal emissions of one of the world's largest smelters.

One of the world's largest smelters has been operating in South Australia since 1889, affecting environment and human health. Here we quantified the magnitude of Pb, Zn and Cd emissions from the smelter sequestered in the soil of an adjacent 110 km2Posidonia australis seagrass meadows. Seagrass core records show that the smelter contaminated the entire area with decreasing sequestration with increasing distance from contamination points. The soil accumulated ~1300 t of Pb, ~3450 t of Zn, and ~ 90 t of Cd since 1889, and sequestered the equivalent of ~20 % of Pb, and ~50 % of Zn and Cd cumulative smelter emissions since 1999, showing that seagrass can be significant, long-term sinks of metal pollution in highly contaminated environments. Conservation efforts should prioritize these seagrass meadows to avoid the potential release of pollutants from their soils following habitat loss, which could turn seagrasses from a sink to a source of pollution.

Effect of simplification from protease inhibitors to boosted atazanavir-based regimens in real-life conditions.

BACKGROUND: Atazanavir (ATV) boosted with ritonavir (ATV/r) is a potent, well-tolerated, once-daily protease inhibitor (PI). Few data are available on this agent as a treatment simplification option for patients taking other PIs. OBJECTIVE: The aim of the study was to determine the effectiveness and safety of ATV-containing regimens in patients who have simplified their antiretroviral treatment. METHODS: SIMPATAZ was a multicentre, prospective, noninterventional study in patients who had undetectable HIV RNA on their current PI-containing therapy and who were switched to an ATV/r-based regimen. Patients underwent a routine physical examination, and data were collected on HIV RNA levels, CD4 cell counts, liver function, lipid parameters, adverse reactions, adherence to treatment and patient satisfaction. RESULTS: A total of 183 patients were enrolled in the study and included in the analysis (80% were male, 29% had AIDS, and 52% were coinfected with HIV and hepatitis B virus or hepatitis C virus). The median baseline CD4 count was 514 cells/µL. Median exposure to previous HIV therapy was 8 years, and 32% of patients had a history of PI failures. Lopinavir boosted with ritonavir was the most frequent PI replaced (62%) and tenofovir+lamivudine /emtricitabine the backbone most used during the study (29%). The study drug was discontinued early by 25 patients (14%), two of whom discontinued as a result of adverse events (Hodgkin lymphoma and vomiting). Two patients died (lung cancer and myocardial infarction). At month 12, 93% of the study population had an undetectable HIV RNA viral load. Hyperbilirubinaemia >3 mg/dL and increased alanine aminotransferase levels>200 IU/L were observed in 38.5% and 4.4% of patients, respectively. Median changes from baseline to month 12 in total cholesterol, triglycerides and low-density lipoprotein cholesterol were -13 mg/dL (-7%; P<0.0001), -19 mg/dL (-13%; P<0.0001) and -7 mg/dL (-6%; P=0.021), respectively. CONCLUSIONS: In a real-world setting, switching from other PIs to ATV/r is a well-tolerated and safe option for improving the lipid profile and for retaining virological response in controlled pretreated patients.

Comparison of antiviral activity of regimens containing nucleos(t)ide (NUC) Pairs in HIV-Infected Patients Initiating REScue therapy (The NUCREST Study).

BACKGROUND: recycling nucleos(t)ides (NUCs) is useful in regions where new antiretrovirals are not available. This study compares the effectiveness of NUC-containing regimens as rescue therapy in routine care. METHODS: retrospective, multicentre cohort study (January 2001 to June 2006) of patients with ≥ 1 virological failure who started therapy with 2 NUCs and 1 non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). The primary endpoint was the rate of treatment response at 6 months (intention-to-treat [ITT] analysis). RESULTS: we included 719 patients (average of 4 prior regimens over a median 6.1 years). The most frequent NUC pairs were tenofovir plus lamivudine (TDF+3TC; 25%), tenofovir plus stavudine (TDF+d4T; 23%), and stavudine plus didanosine (d4T+ddI; 15%). A boosted PI was used in 68% of total cases. Resistance to both NUCs was more frequent in zidovudine plus lamivudine (AZT+3TC; 22.0%), abacavir plus lamivudine (ABC+3TC; 35.5%), and stavudine plus lamivudine (d4T+3TC; 31.2%). No significant differences were observed in treatment response (overall 65%, P = .67); ddI+3TC (71%) and d4T+3TC (53%) had the highest and lowest response rates, respectively. Median time to failure was shorter with d4T+3TC, d4T+ddI, and ABC+3TC (48, 51, and 58 weeks, respectively; P = .0012). Lower response rates associated with an increasing number of thymidine analog mutations (TAMs) were observed for ABC+3TC (P = .027). CONCLUSION: the clinical utility of NUCs for rescue therapy is limited and selection should be individualized. Specific combinations (d4T+3TC and d4T+ddI) might be less efficacious.

Seagrass soil archives reveal centennial-scale metal smelter contamination while acting as natural filters.

The upper Spencer Gulf in South Australia hosts the world's largest single stream Pb-Zn smelter, which has caused environmental and health issues related to elevated metal concentrations in the surrounding environment. The area also has extensive seagrass meadows, occupying >4000 km2. We reconstructed the fluxes of heavy metals over the last ~3000 years through a multi-parameter study of the soil archives formed by the seagrass Posidonia australis. Pb, Zn and Cd concentrations increased up to 9-fold following the onset of smelter operations in the 1880s, and the stable Pb isotopic signatures confirmed the smelter has been the main source of lead pollution in the seagrass soils until present. Preliminary estimates suggest that over the past 15 years seagrass meadows within 70 km2 of the smelter accumulated ~7-15% of the smelter emissions in their soils. Here we demonstrate that seagrass meadows act as pollution filters and sinks while their soils provide a record of environmental conditions, allowing baseline conditions to be identified and revealing the time-course of environmental change.

Role of carbonate burial in Blue Carbon budgets.

Calcium carbonates (CaCO3) often accumulate in mangrove and seagrass sediments. As CaCO3 production emits CO2, there is concern that this may partially offset the role of Blue Carbon ecosystems as CO2 sinks through the burial of organic carbon (Corg). A global collection of data on inorganic carbon burial rates (Cinorg, 12% of CaCO3 mass) revealed global rates of 0.8 TgCinorg yr-1 and 15-62 TgCinorg yr-1 in mangrove and seagrass ecosystems, respectively. In seagrass, CaCO3 burial may correspond to an offset of 30% of the net CO2 sequestration. However, a mass balance assessment highlights that the Cinorg burial is mainly supported by inputs from adjacent ecosystems rather than by local calcification, and that Blue Carbon ecosystems are sites of net CaCO3 dissolution. Hence, CaCO3 burial in Blue Carbon ecosystems contribute to seabed elevation and therefore buffers sea-level rise, without undermining their role as CO2 sinks.

Preneoplastic Lesion in a Pancreas Allograft: Dilemma for the Pancreas Transplant Surgeon.

Although the relationship between immunosuppression and cancer risk is well-documented, the association between immunosuppression and the development of preneoplastic lesions (PNL) is less clear. PNLs pose a unique clinical conundrum in the transplanted pancreas because their prevalence in the general population is not infrequent. We present the case of a 58-year-old man with a history of diabetes mellitus type 1 who underwent successful pancreas transplantation with bladder drainage. His kidney function failed 13 years after his transplant and he developed recurrent painful hematuria with symptomatic anemia 2 years after initiating hemodialysis. Upon work-up, he was found to have a 4 cm intraductal papillary mucinous neoplasm in his pancreas allograft. At his enteric conversion, the intraductal papillary mucinous neoplasm was removed through a distal pancreatectomy due to concern for its malignant potential. He recovered well from surgery and continues to be insulin-free. With the rising incidence of PNLs from improved detection and the improved survival of pancreas allografts, the implications of PNLs may be more pronounced in the future. This case raises several important considerations for the pancreas transplant surgeon regarding adequate allograft surveillance protocols, treatment, and follow-up.

Liver Transplantation in Hepatitis C-Infected Patients: Experience From a South American Transplant Center.

BACKGROUND: Around 2.4% of the world's population is infected with hepatitis C virus (HCV), and it is the most common cause of liver transplantation (LT) in the world. Latin America (LA), with nearly 9% of the world population, has had a continuous increase in the number of LTs per year. Yet, due to the lack of mandatory data collection and a well-developed health-care system, access to transplantation is limited in most LA countries. We report the first LA experience of HCV-infected LT patients. METHODS: We performed a retrospective cohort study by reviewing the medical histories of all HCV-infected LT patients between 1996 and 2016 who acquired HCV before their LT, at the Fundación Valle del Lilí, Cali, Colombia. RESULTS: Between January 1996 and December 2015, a total of 770 LTs were performed, of which 75 had a cirrhotic liver due to HCV infection. With a median follow-up time of 24.4 months (interquartile range [IQR] 4.7-61.2 months), patient survival was 44.9% and 66.9% for the time periods 1996-2006 and 2007-2015, respectively. Hepatocellular carcinoma (HCC) was present in 30.6% of the patients, and overall postoperative complications had an incidence of 80%. CONCLUSIONS: This is the first report of LT in HCV-infected patients in Colombia and in LA. Our results are comparable to those of other transplant centers worldwide with regard to postoperative complications and patient survival. Patients with LT in the 1996-2006 time frame had higher morbidity and mortality. Studies including larger numbers of patients are needed to determine the reason for this finding.

Tumor Biology as Predictor of Mortality in Liver Transplantation for Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most frequent primary malignant liver tumor, with the Milan criteria considered to be the gold standard for patient selection for liver transplantation (LT). MATERIALS AND METHODS: We performed a descriptive observational study, reviewing 20 years of experience of LT in patients with HCC in the Fundacion Valle del Lilí in Cali, Colombia. Subgroup analysis was undertaken for periods 1999 to 2007 and 2008 to 2015. RESULTS: Fifty-seven cases with a pretransplant HCC diagnosis were reviewed. In the first period patients within the Milan criteria had a recurrence-free survival at 5 years of 66.6%, and in those who exceeded the Milan criteria, recurrence-free survival was 75%. In the second period, patients within the Milan criteria, recurrence-free survival at 5 years was 93.5%, and in those who exceeded the Milan criteria, recurrence-free survival was 75.7%. No statistically significant difference was found in either period. For patients with mild and moderate tumor differentiation, the relapse survival rate at 5 years was 69.4% (95% confidence interval [CI] 35.8-87.8) and 74.7% (95% CI 44.5-90), respectively. All patients with poor tumor differentiation relapsed and died within 3 years. CONCLUSION: Global and recurrence-free survival among patients who met and patients who exceeded the Milan criteria was not significantly different, suggesting an expansion of the Milan criteria to include potential recipients who were previously excluded. Obtaining histologic differentiation and identifying vascular invasion will provide a more worthwhile contribution to LT decision making.

Long-term Graft Survival After Kidney Allograft Torsion: Rapid Diagnosis and Surgical Management Key to Reversibility of Injury.

INTRODUCTION: Kidney allograft torsion (KAT) is a rare complication of kidney transplantation (KT) that occurs when the transplanted kidney rotates around its vascular pedicle, which may result in a catastrophic compromise of the graft's blood supply, deterioration of kidney function, and eventually premature graft death. CASE REPORT: We report the case of a patient who had an acute kidney injury (AKI) episode from KAT. Her diagnosis was ascertained expeditiously and she had prompt surgical management. Five years after the KAT event, her baseline creatinine (Cr) stabilized around 1.6 mg/dL and she has achieved >8-year graft survival. DISCUSSION: This case illustrates the reversibility of injury that can occur after a KAT event with a commensurate return to baseline kidney function when KAT is promptly diagnosed and treated. A high index of suspicion of this uncommon but catastrophic complication of KT must be maintained to achieve desirable long-term outcomes. A diagnosis of KAT must be considered when routine etiologies of an acute deterioration of kidney allograft function have been excluded. Finally, prophylactic nephropexy must be strongly considered with intraperitoneal placement of a kidney allograft to avoid KAT.

Sinistral Portal Hypertension After Live Segmental Pancreas Donation: A Long-Term Sequelae Presenting With Life-Threatening Upper Gastrointestinal Hemorrhage.

INTRODUCTION: Variceal hemorrhage from sinistral portal hypertension has never been reported as a complication of live pancreas donation. CASE REPORT: We present a 68-year-old patient who underwent a simultaneous live-donor laparoscopic segmental pancreatectomy and nephrectomy for the purposes of donating to her daughter. Her postoperative course was significant for an episode of acute pancreatitis with a pseudocyst formation. More than a decade later, she presented with variceal hemorrhage from sinistral portal hypertension, which after a diagnostic work-up, prompted a laparoscopic splenectomy. DISCUSSION: Sinistral portal hypertension is a long-term complication of live-donor pancreas donation.

Carbon sequestration by Australian tidal marshes.

Australia's tidal marshes have suffered significant losses but their recently recognised importance in CO2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia's tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha-1 (range 14-963 Mg OC ha-1). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha-1 yr-1. Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC as seaward sites. Australia's 1.4 million hectares of tidal marshes contain an estimated 212 million tonnes of OC in the surface 1 m, with a potential CO2-equivalent value of $USD7.19 billion. Annual sequestration is 0.75 Tg OC yr-1, with a CO2-equivalent value of $USD28.02 million per annum. This study provides the most comprehensive estimates of tidal marsh blue carbon in Australia, and illustrates their importance in climate change mitigation and adaptation, acting as CO2 sinks and buffering the impacts of rising sea level. We outline potential further development of carbon offset schemes to restore the sequestration capacity and other ecosystem services provided by Australia tidal marshes.

Intrapancreatic Splenule in a Pancreas Allograft: Case Report.

A 16-year-old white man was involved in a motor vehicle collision and suffered head, chest, and abdominal trauma. Despite initial resuscitative efforts, he progressed to brain death and was designated to be an organ donor by his family. He had no earlier medical or surgical history and no high-risk behaviors. Blood work revealed normal creatinine, liver function tests, lipase, and amylase. Viral serologies were negative except for cytomegalovirus IgG and Epstein-Barr virus nucleic acid. Imaging revealed a right kidney contusion, a manubrial fracture, and fractures of right first rib and bilateral scapulae. No other abdominal trauma was identified, specifically to the pancreas, duodenum, or spleen. Our transplant center accepted the pancreas from this donor. During back-table inspection of the pancreas, a 1.5 × 1.5 cm dark purple rubbery mass was identified within the parenchyma of the pancreas in the tail. An incisional biopsy of the lesion was sent for frozen section, which yielded a mixed inflammatory infiltrate consisting of neutrophils and lymphocytes and an overlying fibrous capsule. The diagnosis of lymphoma or another neoplasm could not be definitely ruled out. Owing to uncertainty in diagnosis, the entire lesion was excised along with the distal pancreas with the use of a linear stapler. The staple line was oversewn with running 4-0 polypropylene suture, and the pancreas was transplanted. After surgery, the pancreas allograft functioned well with a small pancreatic leak, which had resolved by the first postoperative outpatient visit.

Impact of mooring activities on carbon stocks in seagrass meadows.

Boating activities are one of the causes that threaten seagrass meadows and the ecosystem services they provide. Mechanical destruction of seagrass habitats may also trigger the erosion of sedimentary organic carbon (Corg) stocks, which may contribute to increasing atmospheric CO2. This study presents the first estimates of loss of Corg stocks in seagrass meadows due to mooring activities in Rottnest Island, Western Australia. Sediment cores were sampled from seagrass meadows and from bare but previously vegetated sediments underneath moorings. The Corg stores have been compromised by the mooring deployment from 1930s onwards, which involved both the erosion of existing sedimentary Corg stores and the lack of further accumulation of Corg. On average, undisturbed meadows had accumulated ~6.4 Kg Corg m(-2) in the upper 50 cm-thick deposits at a rate of 34 g Corg m(-2) yr(-1). The comparison of Corg stores between meadows and mooring scars allows us to estimate a loss of 4.8 kg Corg m(-2) in the 50 cm-thick deposits accumulated over ca. 200 yr as a result of mooring deployments. These results provide key data for the implementation of Corg storage credit offset policies to avoid the conversion of seagrass ecosystems and contribute to their preservation.

The value of oxybutynin in transdermal patches for treating overactive bladder.

CONTEXT: There is currently a broad therapeutic arsenal of drugs for treating overactive bladder syndrome (OAB). However, there is still a need for new compounds and for improving known drugs in terms of efficacy, compliance and tolerability. OBJECTIVE: To report the scientific evidence on the safety and efficacy of transdermal oxybutynin (OXY-TDS) for treating OAB. MATERIAL AND METHODS: A systematic review without time restrictions was conducted until May 2015 in the MEDLINE/PubMed database. We also performed a manual review of abstracts published in international urogynaecology congresses. RESULTS: The evaluated studies show that patients treated with OXY-TDS experience a significant reduction in urinary incontinence episodes compared with placebo, which is comparable to that observed in patients treated with oral oxybutynin or with tolterodine. In all of the studies, we observed improvements in symptoms from the second or third week of treatment and in a sustained manner until the end of treatment (6, 12 or 24 weeks). The clinical practice study also showed improved quality of life, achieving benefits in numerous patient profiles, with an efficacy independent of previous treatments. The safety of the drug was demonstrated in the various patient profiles. CONCLUSIONS: OXY-TDS represents an effective alternative for the symptomatic treatment of adult patients with OAB, which, thanks to its pharmacokinetic profile, better tolerability, different administration method and dosage, could represent an added value in treating special populations.

Fate, transport, and interactions of heavy metals.

Mishandling of hazardous wastes, like their unauthorized disposal in abandoned dump yards or sites, in river beds, estuaries or in the sea, causes substantial damage to the environment and its resources and, given the persistence and toxicity of these pollutants, they can seriously damage human health and quality of life. The importance of controlling management, transport, and disposal of toxic and hazardous substances in the years to come will be a crucial issue in the design and implementation of public policies. This is especially true for residents of such areas as the border between the United States and Mexico, where historically hazardous wastes have been a public health and environmental problem. The aim of this Conference on the Fate, Transport, and Interactions of Metals, A Joint United States-Mexico Conference, co-sponsored by the National Institute of Environmental Health Sciences, Superfund Basic Research Program, the National University of Mexico, Program for the Environment and the Pan American Health Organization, and hosted by the University of Arizona Center for Toxicology, College of Pharmacy, is to begin a joint effort by the United States and Mexico to better understand the complex problems related to heavy metals as hazardous wastes.

Inhibition of both Na/H and bicarbonate-dependent exchange is required to prevent recovery of intracellular pH in single cardiomyocytes exposed to metabolic stress.

Although tight regulation of intracellular pH (pHi) is critical for the survival under stress, paradoxically a slowed recovery of pHi under hypoxic injury may be cardioprotective. In this study, we investigated the recovery of pHi after hypoxia-induced intracellular acidosis in cardiomyocytes loaded with the H+-sensitive dye SNARF-1. Exposure of single cardiomyocytes to 2,4-dinitrophenol (DNP), an inhibitor of mitochondrial oxidative phosphorylation, induced significant intracellular acidification. However, within 10-12 min upon removal of DNP, cardiomyocytes restituted their intracellular H+ concentration. The presence either of 5-N-ethyl-N-isopropylamiloride (EIPA) an inhibitor of Na/H antiporter, or 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), an inhibitor of bicarbonate-dependent exchange, did not modify the cellular response to DNP. But, combined use of EIPA and DIDS prevented the restitution of intracellular pH following removal of DNP. This study, thus, demonstrated, for the first time, that blockade of both Na/H and bicarbonate-dependent exchange is necessary and sufficient to maintain the hypoxia-induced intracellular acidification. Therefore, concomitant blockade of both pH-regulating mechanisms deserves to be further considered as a novel strategy against hypoxia-reoxygenation injury in the heart.

Growth rate of Ulva rigida in different Mediterranean eutrophicated sites.

The growth of juvenile populations of Ulva rigida C. Agardh was measured by means of immersion in in situ cages against environmental parameters (temperature, incident light, salinity, dissolved inorganic nitrogen and dissolved reactive phosphorus) in four different eutrophicated southern sites: Channel of the Thau lagoon (France), Lido, Sacca Sessola and Fusina stations (Venice lagoon, Italy). The growth curves as a function of temperature showed that, in all cases, the maximal temperature for Ulva growth was 17 degrees C (limitation in growth below 7 degrees C and above around 25 degrees C). The growth analysis of these four sites showed seasonal differences. In the least eutrophicated and calmest Lido station, grazing and dissolved reactive phosphorus (seven times lower at Lido than at Thau) played a key role. At Thau and Fusina, which are eutrophicated and turbid environments, the incident light had a strong impact on growth. Sacca Sessola, with an intermediate position between the above two mentioned situations, showed the highest growth rate. The values and relative growth rate (RGR) curves of the Mediterranean and open-sea northern sites are discussed. In particular, the temperature defines the type of growth curve (unimodal or bimodal) and the incident light is responsible for the low Mediterranean RGR values (<10% day(-1)).