Preliminary Assessment of Legacy and Current-Use Pesticides in Franciscana Dolphins from Argentina.

The change towards intensive agriculture has led to an increase in the use of pesticides. In addition, legacy pesticides, such as organochlorines are still present in the environment. Ten Franciscana dolphins were accidentally killed by netting in a coastal area of Argentina in Buenos Aires province. From these animals, organochlorine, organophosphate and pyrethroid pesticides were analyzed in liver, bubbler and melon tissues. The concentrations of Σendosulfan ranged from not detectable values (nd) to 3539 ng g-1 lw, with the maximum level in melon tissue. DDE was present in 60% of all samples at concentrations from nd to 6672 ng g-1 lw, indicating historical DDT contamination. The presence of endosulfan and heptachlor in a nursling calf indicated a transfer of these pesticides through lactational and placental transport. The concentrations of organophosphates and pyrethroids were below the limit of detection, reflecting the low persistence of these compounds.

Blood cadmium and metallothionein concentrations in females of two sympatric pinnipeds species.

Otaria flavescens (SASL) and Arctocephalus australis (SAFS) are endemic of South America. The aims were to assess Cd concentrations in red blood cells (RBC) and plasma from free living females of both species; and to establish metallothioneins (MT) levels in blood fractions and the possible relationship between MTs and Cd. Blood of fifteen SASL and eight SAFS females from Isla de Lobos were analyzed (years 2010-2011). All animals showed Cd levels above the detection limit. Cd concentrations on SAFS were higher than those of SASL, however, no significant differences were observed on metal concentrations between cell fractions by species. Metal levels were associated with a natural presence and ecological-trophic habits of the prey items. On SASL the MT concentrations between fractions were similar; whereas, SAFS plasma concentrations were higher than RBC. The results reported constitute the first information on Cd and MT blood levels in these species.

Metals as chemical tracers to discriminate ecological populations of threatened Franciscana dolphins (Pontoporia blainvillei) from Argentina.

Franciscana dolphins are the most impacted small cetacean in the Southwestern Atlantic Ocean, classified as Vulnerable A3d by IUCN. Essential (Fe, Mo, Mn, Cr, Ni, Co) and non-essential (Ag, Pb, Sn) trace elements (TEs) were measured in liver, kidney, and brain samples of by-catch Franciscana dolphins that were living in estuarine (n = 21) and marine (n = 21) habitats (1) to assess whether TEs posed a threat and (2) to evaluate the suitability of TEs for discriminating ecological populations of this species in Argentinean waters. Essential TEs showed little variation in tissues from both groups in agreement with levels reported for other cetaceans and suggesting that these concentrations correspond to normal physiological levels. Non-essential TEs were higher in estuarine juveniles and adults dolphins than in marine specimens. These results suggest anthropogenic sources associated with estuarine area and that Franciscana dolphins are good sentinels of the impact of the environment. The difference in the concentrations of TEs beetwen ecological populations appeared to be related to distinct exposures in both geographical areas, and it is suggested that Ag and Sn concentrations in adults are good chemical tracers of anthropogenic input of TEs. These results provide additional information for improved management and regulatory policy.

The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei).

The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity.

Histopathological and biochemical evidence of hepatopancreatic toxicity caused by cadmium in white shrimp, Palaemonetes argentinus.

Cadmium (Cd) is one of the most common pollutants in the environment and induces a range of tissue changes or damages and organ dysfunction. The histopathological effects of Cd and lipid peroxidation (LPO) on hepatopancreas of the freshwater shrimp, Palaemonetes argentinus, were studied. Shrimp were obtained from two lagoons with contrasting environmental quality, De los Padres (LP, impacted site) and Nahuel Rucá (NR, reference site), and were exposed to 3.06 and 12.24µgCdL(-1) for 3, 7, 10 and 15 days. The health status of both populations was also evaluated by histological analysis of control individuals. After exposure, shrimp were transferred to clean water for 28 days to evaluate the recuperation capacity of hepatopancreas. Control shrimp from NR exhibited a normal hepatopancreas structure; unlike control shrimp from LP which showed several alterations. These results were attributed to the different environmental quality of lagoons. The exposure to Cd resulted in several alterations in the histological structure of the hepatopancreas of both populations. The observed alterations included haemocytic and connective infiltrations in the intertubular space, erosioned microvilli, ripple of basal lamina, atrophied epithelium and necrosis, however, the latter was only observed in shrimp from LP. The exposure also caused an increase of LPO levels in both populations. P. argentinus was able to repair the hepatopancreas structure from the damage caused by Cd, evidenced by the histopathological results and LPO levels. Obtained results are indicating that the histological analysis of the hepatopancreas proved to be a highly sensitive method for evaluating water quality, in both environmental and laboratory conditions.

Metallothioneins pattern during ontogeny of coastal dolphin, Pontoporia blainvillei, from Argentina.

Metallothioneins are signals of metal exposure and widely used in biomonitoring. Franciscana dolphin is an endemic cetacean from the Southwestern Atlantic Ocean, classified as Vulnerable A3d by the IUCN. Metallothionein, copper and zinc in Franciscana were assessed in two geographic groups; one inhabits La Plata River estuary, anthropogenically impacted, and the other inhabits marine coastal ecosystems, with negligible pollution. Despite the environment, hepatic and renal MT concentrations were similar, but there was a declining trend from early to later developmental stages. Metallothionein K/L, Cu and Zn levels corresponded to normal reported ranges. MT was not related with Cd. Fetal concentrations were higher than its mother. These results and the health status of dolphins are suggesting that MT correspond to physiological ranges for the species, and they are closely to homeostasis of Zn and Cu, according to its ontogenetic changes. The information constitutes the first MT information on Franciscana dolphin and can be considered as baseline for the species conservation.

Fine scale distribution constrains cadmium accumulation rates in two geographical groups of Franciscana dolphin from Argentina.

Franciscana dolphin is an endemic cetacean in the southwestern Atlantic Ocean and is classified as Vulnerable A3d by the International Union for Conservation of Nature. Cadmium accumulation was assessed in two geographic groups from Argentina; one inhabits the La Plata River estuary, a high anthropogenic impacted environment, and the other is distributed in marine coastal, with negligible pollution. Despite the environment, marine dolphins showed an increase of renal Cd concentrations since trophic independence; while in estuarine dolphins was from 6 years. This is associated with dietary Argentine anchovy which was absent in the diet of estuarine dolphins, being a trophic vector of cadmium in shelf waters of Argentina. Cluster analysis also showed high levels of cd in association with the presence of anchovy in the stomach. The difference in the fine scale distribution of species influences dietary exposure to Cd and, along with other data, indicates two stocks in Argentina.

[Early gastric carcinoma: short and long term results of surgical treatment]. / Carcinoma gastrico iniziale: risultati a breve e lungo termine della terapia chirurgica.

This paper reports Authors' experience in 58 cases of early gastric cancer observed between 1972 and 1990. The diagnosis of E.G.C. was frequently obtained in patients with recent dyspeptic symptoms. The diagnostic importance of endoscopic procedures, upper gastrointestinal X-rays and endoscopic ultrasonography is underlined. The choice of total gastrectomy with the standardized dissection of regional lymph nodes in order to treat multicentric or upper gastric malignancies v.s. distal gastrectomy for antral lesions is discussed. The cumulative survival rate was 84.4%; local recurrence rate was 4.2%.

[Experimental research on hemorrhagic shock in the rabbit. Acid-base equilibrium and survival with 6-methylprednisolone and gelatin administration]. / Ricerche sperimentali nello shock emorragico del coniglio. Equilibrio acido-base e sopravvivenza dopo somministrazione di 6-metil-prednisolone e gelatina.

A previously described method was used to induce haemorrhagic shock in the rabbit by removing 40% of the circulating mass. This had been previously established as 2.6 +/- 0.5 kg-1 by a radioisotopic technique. Survivals were determined 1 and 2 weeks later after treatment with 40 mg/kg-1 6-MPD and vascular refilling with 3.5% gelatine equal to the amount removed. The blood gas analysis and EAB findings suggested that haemorrhagic shock includes both a fast and a slow physiopathological stage, and that the results of treatment are strictly linked to the time of its commencement. Metabolic acidaemia and respiratory alkalosis was constant, and all the controls died within 2 days, 6-MPD was not able to normalise the EAB, but ensured 100% survival at 2 weeks. Gelatin brought the lab data close to normal, but only ensured 100% survival at 2 weeks if given immediately after the removal of blood.

[Radiothermolumiscent dosimetry in plesioroentgenotherapy]. / Dosimetria a radiotermoluminescenza in plesioroentgenterapia

The employment of thermoluminescence dosimeters in the evaluation of X-rays emitted by a plesiotherapy apparatus was investigated. It was found that lithium fluoride microdosimeters gave good linearity of response in function of the energy involved. This response was also repeatable as required.