Interannual variability in Dinophysis spp. abundance and toxin accumulation in farmed mussels (Perna perna) in a subtropical estuary.

This study evaluated an 8-year dataset (2007 to 2015, except 2008) in the attempt to identify the most susceptible periods for the occurrence of diarrheic shellfish poisoning (DSP) episodes associated with the presence of toxigenic dinoflagellates, Dinophysis spp., in the mussel farming area of Babitonga Bay (southern Brazil). Dinophysis acuminata complex was the most frequent (present in 66% of the samples) and abundant (max. 4100 cells L-1) taxon, followed by D. caudata (14%; max. 640 cells L-1) and D. tripos (0.9%; max. 50 cells L-1). There was a marked onset of the annual rise in Dinophysis spp. abundance during weeks 21-25 (early winter) of each year, followed by a second peak on week 35 (spring). Mussel (Perna perna) samples usually started testing positive in DSP mouse bioassays (MBA) in late winter. Positive results were more frequent in 2007 and 2011 when the mean D. acuminata complex abundance was ~ 500 cells L-1. Although positive DSP-MBA results were observed in only 11% of the samples during the studied period, the toxin okadaic acid (OA) was present in 90% of the analyzed mussels (max. 264 µg kg-1). MBA results were positive when D. acuminata complex cell densities exceed 1200 ± 300 cells L-1, while trace toxin amounts could be detected at cell densities as low as 150 ± 50 cells L-1 (free OA) to 200 ± 100 cells L-1 (conjugated OA). Low salinity and the meteorological conditions triggered by La Niña events were the main factors associated with both Dinophysis abundance and OA accumulation in mussels.

Respiratory quotient estimations as additional prognostic tools in early septic shock.

Central venous-to-arterial carbon dioxide difference (PcvaCO2), and its correction by the arterial-to-venous oxygen content difference (PcvaCO2/CavO2) have been proposed as additional tools to evaluate tissue hypoxia. Since the relationship between pressure and content of CO2 (CCO2) might be affected by several factors, some authors advocate for the use of CcvaCO2/CavO2. The aim of the present study was to explore the factors that might intervene in the difference between PcvaCO2/CavO2 and CcvaCO2/CavO2, and to analyze their association with mortality. Observational study in a 30-bed mixed ICU. Fifty-two septic shock patients within the first 24 h of ICU admission were studied. After restoration of mean arterial pressure, hemodynamic and metabolic parameters were evaluated. A total of 110 sets of measurements were performed. Simultaneous PcvaCO2/CavO2 and CcvaCO2/CavO2 values were correlated, but agreement analysis showed a significant proportional bias. The difference between PcvaCO2/CavO2 and CcvaCO2/CavO2 was independently associated with pH, ScvO2, baseline CcvaCO2/CavO2 and hemoglobin. A stepwise regression analysis showed that pH was the single best predictor for the magnitude of such difference, with very limited effect of other variables. At inclusion, variables associated with ICU-mortality were lactate, pH, PcvaCO2/CavO2, and the difference between PcvaCO2/CavO2 and CcvaCO2/CavO2. Initial ScvO2, PcvaCO2, CcvaCO2/CavO2, and cardiac index were not different in survivors and non-survivors. In a population of early septic shock patients, simultaneous values of PcvaCO2/CavO2 and CcvaCO2/CavO2 were not equivalent, and the main determinant of the magnitude of the difference between these two parameters was pH. The PcvaCO2/CavO2 ratio was associated with ICU mortality, whereas CcvaCO2/CavO2 was not.

Central venous-to-arterial carbon dioxide difference and the effect of venous hyperoxia: A limiting factor, or an additional marker of severity in shock?

Central venous-to-arterial carbon dioxide difference (PcvaCO2) has demonstrated its prognostic value in critically ill patients suffering from shock, and current expert recommendations advocate for further resuscitation interventions when PcvaCO2 is elevated. PcvaCO2 combination with arterial-venous oxygen content difference (PcvaCO2/CavO2) seems to enhance its performance when assessing anaerobic metabolism. However, the fact that PCO2 values might be altered by changes in blood O2 content (the Haldane effect), has been presented as a limitation of PCO2-derived variables. The present study aimed at exploring the impact of hyperoxia on PcvaCO2 and PcvaCO2/CavO2 during the early phase of shock. Prospective interventional study. Ventilated patients suffering from shock within the first 24 h of ICU admission. Patients requiring FiO2 ≥ 0.5 were excluded. At inclusion, simultaneous arterial and central venous blood samples were collected. Patients underwent a hyperoxygenation test (5 min of FiO2 100%), and arterial and central venous blood samples were repeated. Oxygenation and CO2 variables were calculated at both time points. Twenty patients were studied. The main cause of shock was septic shock (70%). The hyperoxygenation trial increased oxygenation parameters in arterial and venous blood, whereas PCO2 only changed at the venous site. Resulting PcvaCO2 and PcvaCO2/CavO2 significantly increased [6.8 (4.9, 8.1) vs. 7.6 (6.7, 8.5) mmHg, p 0.001; and 1.9 (1.4, 2.2) vs. 2.3 (1.8, 3), p < 0.001, respectively]. Baseline PcvaCO2, PcvaCO2/CavO2 and ScvO2 correlated with the magnitude of PO2 augmentation at the venous site within the trial (ρ -0.46, p 0.04; ρ 0.6, p < 0.01; and ρ 0.7, p < 0.001, respectively). Increased PcvaCO2/CavO2 values were associated with higher mortality in our sample [1.46 (1.21, 1.89) survivors vs. 2.23 (1.86, 2.8) non-survivors, p < 0.01]. PcvaCO2 and PcvaCO2/CavO2 are influenced by oxygenation changes not related to flow. Elevated PcvaCO2 and PcvaCO2/CavO2 values might not only derive from cardiac output inadequacy, but also from venous hyperoxia. Elevated PcvaCO2/CavO2 values were associated with higher PO2 transmission to the venous compartment, suggesting higher shunting phenomena.

The corrosion resistance of Wiron(®)88 in the presence of S. mutans and S. sobrinus bacteria.

The corrosion resistance of Wiron(®)88, a Ni-Cr-Mo alloy, was evaluated in liquid growth media in the absence and presence of the Streptococcus sobrinus and Streptococcus mutans strains. Open circuit potential measurements, cyclic voltammetry, linear sweep voltammetry, as well as electronic microscopy coupled to electron diffraction spectroscopy (SEM/EDS), were the main techniques used in this study. It was concluded that the presence of S. sobrinus and S. mutans have only a slight effect on the corrosion resistance of the Wiron(®)88 alloy, with the S. mutans being slightly more aggressive. For both strains the corrosion resistance R p is of the same order (kΩ cm(2)). After 24 h immersion the S. sobrinus lead to and R p of 11.02, while the S. mutans lead to of 5.59 kΩ cm(2). SEM/EDS studies on the Wiron(®)88 samples, with 24 days of immersion, at 37 °C, have confirmed bio-corrosion of the alloy occurring through the dissolution of Ni as Ni(2+) and formation of chromium and molybdenum oxides. The bacterial adhesion to the surface is not uniform.

Recurrent blooms of Heterosigma akashiwo (Raphidophyceae) in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil.

Six blooms of Heterosigma akashiwo (Raphidophyceae) were observed from March 2007 through March 2008 in the Rodrigo de Freitas Lagoon, a semi-confined eutrophic system located in Rio de Janeiro state, southeast Brazil. Vegetative cells of H. akashiwo analysed by optical and electron microscopy showed morphology as described in the literature. The blooms (2.8 × 10(4) to 4 × 10(8) cell.L(-1)) were restricted to the middle section of the Piraquê Channel, which is situated in the northeastern part of the lagoon and receives freshwater inflow. The salinity of subsurface water and the channel depth showed significant negative correlations with H. akashiwo abundances, and appeared to restrict the blooms to this compartment of the lagoon. No fish mortality was associated with the H. akashiwo blooms, nor were brevetoxins detected in a cell extract obtained from the bloom observed on 19 March 2007.

Single surgeon coelioscopic orchiectomy of desert tortoises (Gopherus agassizii) for population management.

Orchiectomy in chelonians is a challenging procedure, especially in large species with deep and elongated testes and extensive mesorchial attachments. Single surgeon coelioscopic orchiectomy was performed in seven adult desert tortoises (Gopherus agassizii), maintained at the Desert Tortoise Conservation Center (DTCC) in Las Vegas, for population management. Surgery was successfully conducted through a bilateral prefemoral approach via sequential vascular clip ligation and radiosurgery (monopolar/bipolar). Bipolar endoscopic forceps were considered indispensable due to the extensive mesorchial attachments and their close association with the kidney. A mechanical arm was effectively used to permit orchiectomy to be completed by a single surgeon. Six of seven animals recovered from anaesthesia. Necropsy demonstrated that the death of the other was unrelated to surgical complications. One animal experienced surgically significant haemorrhage, but still made a clinical recovery. The six tortoises were returned to the DTCC and, six months postoperatively, remain healthy. This small study suggests this minimally invasive technique is an effective method for bilateral orchiectomy in desert tortoises and might be preferable in large chelonians with elongated testes.

Screening the toxicity and toxin content of blooms of the cyanobacterium Trichodesmium erythraeum (Ehrenberg) in northeast Brasil

Blooms of the cyanobacterium Trichodesmium occur in massive colored patches over large areas of tropical and subtropical oceans. Recently, the interest in such events has increased given their role in major nitrogen and carbon dioxide oceanic fluxes. Trichodesmium occurs all along the Brazilian coast and patches frequently migrate towards the coast. In this paper we screen the toxicity and toxin content of Trichodesmium blooms off the coast of Bahia state. Four samples, collected from February to April 2007, were analyzed. Organisms were identified and assessed for toxicity by means of several methods. Analogues of microcystins, cylindrospermopsins and saxitoxins were analyzed using HPLC. Microcystins were also assayed through ELISA. Results showed dominance of T. erythraeum, which makes up as much as 99 percent of cell counts. Other organisms found in smaller quantities include the dinoflagellates Prorocentrum minimum and P. rhathymum. Extracts from all samples delayed or interrupted sea urchin larval development, but presented no acute toxicity during a mouse bioassay. Saxitoxin congeners and microcystins were present at low concentrations in all samples, occurrences that had not previously been reported in the literature. Despite our finding of saxitoxin analogues and microcystins in Trichodesmium blooms, these toxins do not represent a potential harm to human health by primary contact. We conclude, based on our results and those reported in the recent literature, which differ from results published in 1963, that although toxins are present, there is no evidence that T. erythraeum blooms represent a threat to humans.

Solitary hemangioma of the small bowel disclosed by wireless capsule endoscopy.

A nine-year-old child presented with melena and anemia. She had similar symptoms five months earlier and had undergone an extensive workup with upper gastrointestinal endoscopy and colonoscopy, both normal and 99m-Tc-RBC-scintigraphy which was positive in the right lower quadrant. This time, capsule endoscopy was performed and disclosed an hemangioma with a dark spot suggesting recent bleeding in the ileum. The lesion was resected. Pathological examination revealed a transmural cavernous hemangioma. Small bowel hemangioma is a rare disease. Its diagnosis is extremely difficult and is usually obtained during surgery. Capsule endoscopy is an endoscopic technique that can improve preoperative diagnosis, as reported in the present case.

Antioxidant responses and oxidative stress after microcystin exposure in the hepatopancreas of an estuarine crab species.

Antioxidant responses and oxidative stress were evaluated in the hepatopancreas of the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura) after oral microcystin administration. Responses were evaluated through antioxidant enzyme activities (catalase-(CAT), superoxide dismutase, glutathione-S-transferase- (GST)). Nonproteic sulfhydril (NP-SH) groups, oxygen consumption, lipid peroxides (LPO), and oxidized proteins were also measured. Microcystin administration increased the oxygen consumption. GST activity and NP-SH concentration showed transient increases and CAT activity showed a peak and then a reduction. Oxidative damage was evidenced with regard to LPO content and suggested by the inhibition of CAT activity at the end of the experiment, indicating that the antioxidant response induced by the toxin was insufficient. A lowering in the number of hepatopancreatic B cells should be related to microcystin elimination.

Antioxidant responses after microcystin exposure in gills of an estuarine crab species pre-treated with vitamin E.

Microcystins are hepatotoxins suspected to generate oxidative stress. This mechanism was evaluated in gills of the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura). Adult male crabs were fed ground beef with or without vitamin E (600 mg/kg). Microcystin (1.21 microg/kg) was daily administered through forced ingestion, for 7 days. After exposure, catalase activity was reduced in posterior gills of crabs supplemented with vitamin E. A lower increment in glutathione S-transferase activity (GST) was observed in organisms pretreated with vitamin E and then exposed to microcystin with respect to those exposed to the toxin but not pretreated with the vitamin. Pretreatment with vitamin E also increased nonproteic sulfhyrdil groups and this effect was not observed after microcystin exposure. The fact that supplementation with antioxidants such as vitamin E modulates GST activity indicates the direct or indirect involvement of microcystin in oxidative stress generation.

[Diagnostic value of transesophageal echocardiography in the diagnosis of infectious endocarditis. A comparative analysis comparing it with transthoracic echocardiography]. / Valor diagnóstico do ecocardiograma transesofágico no diagnóstico da endocardite infecciosa. Análise comparativa com o transtorácico.

The aim of this study is to compare the performance of Transesophageal Echocardiography (TEE) and the Transthoracic approach (TTE) in the diagnosis of Infectious Endocarditis (IE). Between October/90, the data we started transesophageal ultrasound, till April/92, we performed 33 TTE in inpatients with clinical suspicion of IE. Twenty pts (61%) had one or two prosthesis. All the pts had a previous TTE. The diagnosis of IE determined by non-echocardiographic data was established on 18 pts. The other 15 pts, without clinical criteria of IE, were used as the control group. The Echocardiographic criteria for the diagnosis of IE were for both diagnostic tools the presence of masses suggesting vegetation of abscess. The diagnosis was correctly made by TTE in 8 of the 18 pts (S-44%) and by TEE in 16 of the 18 pts (S-89%) with clinical criteria for IE. Of the 15 patients without clinical criteria for IE 14 were correctly identified by TTE (Sp-93%) and 13 by TEE (Sp-89%). With a similar VPP (89%) for both tools has TEE a significative higher value for NPV than TTE (87% vs 58%). This study suggests that TEE, at a same level of specificity as TTE, is highly more sensitive in the diagnosis of IE (S-89 14 for TEE and S-44 23 for TTE) a figure that recommends that all patients with clinical suspicion of IE and a negative TTE should perform a TEE.

[AIDS and the heart]. / SIDA e coração.

The authors present an historical introduction, a geographic description and an epidemiologic review of AIDS in Portugal and in the world. After HIV presentation, a laboratory and clinic approach to this syndrome is done, discussing its systemic manifestations. A special interest is given to the different aspects of cardiac lesions particularly its myocardial involvement. Analysing therapeutic results, despite of dismal present of clinic investigation, some hope is being invested in future achievements.