Warm temperatures, cool sponges: the effect of increased temperatures on the Antarctic sponge Isodictya sp.

Although the cellular and molecular responses to exposure to relatively high temperatures (acute thermal stress or heat shock) have been studied previously, only sparse empirical evidence of how it affects cold-water species is available. As climate change becomes more pronounced in areas such as the Western Antarctic Peninsula, both long-term and occasional acute temperature rises will impact species found there, and it has become crucial to understand the capacity of these species to respond to such thermal stress. Here, we use the Antarctic sponge Isodictya sp. to investigate how sessile organisms (particularly Porifera) can adjust to acute short-term heat stress, by exposing this species to 3 and 5 °C for 4 h, corresponding to predicted temperatures under high-end 2080 IPCC-SRES scenarios. Assembling a de novo reference transcriptome (90,188 contigs, >93.7% metazoan BUSCO genes) we have begun to discern the molecular response employed by Isodictya to adjust to heat exposure. Our initial analyses suggest that TGF-ß, ubiquitin and hedgehog cascades are involved, alongside other genes. However, the degree and type of response changed little from 3 to 5 °C in the time frame examined, suggesting that even moderate rises in temperature could cause stress at the limits of this organism's capacity. Given the importance of sponges to Antarctic ecosystems, our findings are vital for discerning the consequences of short-term increases in Antarctic ocean temperature on these and other species.

Description and evaluation of a peracetic acid air sampling and analysis method.

Peracetic acid (PAA) is a corrosive chemical with a pungent odor, which is extensively used in occupational settings and causes various health hazards in exposed workers. Currently, there is no US government agency recommended method that could be applied universally for the sampling and analysis of PAA. Legacy methods for determining airborne PAA vapor levels frequently suffered from cross-reactivity with other chemicals, particularly hydrogen peroxide (H2O2). Therefore, to remove the confounding factor of cross-reactivity, a new viable, sensitive method was developed for assessment of PAA exposure levels, based on the differential reaction kinetics of PAA with methyl p-tolylsulfide (MTS), relative to H2O2, to preferentially derive methyl p-tolysulfoxide (MTSO). By quantifying MTSO concentration produced in the liquid capture solution from an air sampler, using an internal standard, and utilizing the reaction stoichiometry of PAA and MTS, the original airborne concentration of PAA is determined. After refining this liquid trap high-performance liquid chromatography (HPLC) method in the laboratory, it was tested in five workplace settings where PAA products were used. PAA levels ranged from the detection limit of 0.013 parts per million (ppm) to 0.4 ppm. The results indicate a viable and potentially dependable method to assess the concentrations of PAA vapors under occupational exposure scenarios, though only a small number of field measurements were taken while field testing this method. However, the low limit of detection and precision offered by this method makes it a strong candidate for further testing and validation to expand the uses of this liquid trap HPLC method.

Acute toxicity of peroxy sulfonated oleic acids (PSOA) to freshwater aquatic species and sludge microflora as observed in laboratory environments.

BACKGROUND: Peroxy sulfonated oleic acids (PSOA) is a novel surfactant peracid. The commercial applications of PSOA result in the chemical primarily being disposed of via industrial waste water effluent. Given this manner of disposal, it is important to understand the aquatic hazards of the chemical to better assess the risk posed to aqueous environments. Acute aquatic toxicity laboratory experiments were performed to evaluate aquatic hazards and were conducted according to standard OECD test guidelines with rainbow trout (Oncorhynchus mykiss), water fleas (Daphnia magna) and algae (Pseudokirchneriella subcapitata). In addition, microbial toxicity was evaluated in activated sludge obtained from a domestic sewage treatment facility. RESULTS: Lethal concentration in 50 % of test species (LC50) and effect concentration in 50 % of test species (EC50) values for PSOA ranged from 0.75 to 5.44 mg/L, representing a relatively small range spanning less than an order of magnitude. No observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) ranges were also relatively small, with ranges of 0.25-1.66 and 0.5-3.6 mg/L, respectively. The EC50, LOEC and NOEC values for microbial toxicity were 216, 60 and 20 mg/L, respectively. Predicted no effect concentrations (PNEC) for aqueous media were based on the 96-h LC50 (0.75 mg/L) for O. mykiss, the organism displaying the greatest sensitivity to PSOA. These values were derived for freshwater, marine water and intermittent releases to water and ranged from 7.5 × 10-5 to 7.5 × 10-3 mg/L. A sewage treatment plant PNEC of 2 mg/L was derived based on an activated sludge 3-h NOEC of 20 mg/L. CONCLUSION: These values, along with the anticipated environmental fate and transport for PSOA, were considered in assessing the overall aquatic risk posed by this chemical. Despite the relatively high acute aquatic hazards for PSOA, environmental modeling suggests the overall risk of PSOA to aqueous environments is low based on its anticipated uses. This conclusion is consistent with the significant processing of industrial wastewater by onsite or municipal wastewater treatment facilities prior to release to the environment.

Evaluation of the toxicity data for peracetic acid in deriving occupational exposure limits: a minireview.

Peracetic acid (PAA) is a peroxide-based chemistry that is highly reactive and can produce strong local effects upon direct contact with the eyes, skin and respiratory tract. Given its increasing prominence in industry, attention has focused on health hazards and associated risks for PAA in the workplace. Occupational exposure limits (OEL) are one means to mitigate risks associated with chemical hazards in the workplace. A mini-review of the toxicity data for PAA was conducted in order to determine if the data were sufficient to derive health-based OELs. The available data for PAA frequently come from unpublished studies that lack sufficient study details, suffer from gaps in available information and often follow unconventional testing methodology. Despite these limitations, animal and human data suggest sensory irritation as the most sensitive endpoint associated with inhalation of PAA. Rodent RD50 data (the concentration estimated to cause a 50% depression in respiratory rate) were selected as the critical studies in deriving OELs. Based on these data, a range of 0.36-0.51mg/m(3) (0.1-0.2ppm) was calculated for a time-weighted average (TWA), and 1.2-1.7mg/m(3) (0.4-0.5ppm) as a range for a short-term exposure limit (STEL). These ranges compare favorably to other published OELs for PAA. Considering the applicable health hazards for this chemistry, a joint TWA/STEL OEL approach for PAA is deemed the most appropriate in assessing workplace exposures to PAA, and the selection of specific values within these proposed ranges represents a risk management decision.

Toxicological evaluation of peroxy sulfonated oleic acid (PSOA) in subacute and developmental toxicity studies.

Peroxy sulfonated oleic acid (PSOA) is a new coupler used in sanitizing solutions primarily for the food and beverage industry. The toxicity of PSOA was evaluated in a 28-day repeat dose study according to OECD 407 guidelines with a 14-day recovery period and a developmental toxicity study according to OECD 414 guidelines. In both studies, PSOA was administered once daily via gavage at 0, 5, 15 and 50 mg/kg/day to Sprague-Dawley rats. Due to its corrosive properties, the highest test concentration was restricted to 0.5%. No findings related to PSOA administration were observed for the 28-day repeat-dose study and the NOEL is 50 mg/kg/day. Additionally, no impairment of the mucous membranes of the gastrointestinal tract was observed up to 0.5%, which is considered the NOEC in terms of local toxicity. For the developmental study, an embryo-fetal NOEL of 50 mg/kg/day was identified and the maternal NOEL is considered to be 15 mg/kg/day, based on slight reductions in maternal body weight and food consumption, as well as a modest increase in the incidence of clinical observations at the high dose. These findings demonstrate that PSOA appears to have minimal potential to induce toxicity associated with repeat-dose or developmental exposures.

Prevalence and factors associated with the presence of abnormal function liver tests in patients with ulcerative colitis.

AIM: To investigate the prevalence of abnormal function liver tests and risk factors associated with their development in Mexican patients with UC. METHODS: A total of 200 patients with confirmed diagnosis of UC were evaluated prospectively during a one year period from January 1, 2007 to December 31, 2008. RESULTS: A total of 94 females and 106 males patients with UC were analyzed. The age at diagnosis was 31.4 ± 13.2 years and the mean of disease duration was 6.7 ± 5.2 years. We found a high prevalence of abnormal function livers tests in 40% of UC patients. The pattern of abnormal function liver test was hepatitis in 70%, cholestatic (20%) and mixed (10%). The most common cause of abnormal function liver test was transient elevation in 50 patients (63%) followed by fatty liver disease (11.2%), primary sclerosing cholangitis (6.3%), drug-toxicity (6%) and others (13.5%) including chronic hepatitis C, total parenteral nutrition, granulomatous and ischemic hepatitis. In the multivariate logistic regression model, active disease, colectomy and abdominal sepsis were factors that persisted associated with the development of abnormal liver tests in UC patients. CONCLUSION: A high prevalence of abnormal function liver tests (40%) was found in Mexican UC patients is likely to be related to active disease, colectomy and the presence of sepsis.

Anabolic-androgenic steroids and liver injury.

Athletes and nonathletes have been using anabolic-androgenic steroids (AAS) for a long time, in an inadequate and unsurveilled manner, with the aim of improving sports performance or for cosmetic purposes. AAS consumption is becoming more widespread and involving younger people, and there is a trend for self-administration of higher doses and for combining AAS with other potentially harmful drugs. Almost any subject abusing AAS will experience adverse effects. Therefore, adverse effects from these exposures, including liver toxicity, are expected to increase in the years to come. The present manuscript describes a representative case of intrahepatic cholestasis with the intention to discuss AAS-related liver toxicity (including the potential therapeutic role of ursodeoxycholic acid) and to comment on several aspects of the clinical scenario the gastroenterologist should be aware of.

Revascularización de las secuelas cerebrovasculares de tipo oclusivo con el epiplón / Revascularization of the cerebrovascular secuela of the oclusive type with the epiplon

Presentamos 25 pacientes con secuelas de enfermedad cerebro vascular de tipo oclusivo que recibieron transplante de epiplón al encéfalo. En el área de lesión se encontraron arterias con flujo sanguíneo residual centrípeta al área de infarto. La mejoría neurológica ocurrió dentro de los primeros días o semanas de la operación. Creemos que estos resultados son debidos a la revascularización y a la influencia de factores neurotróficos proporcionados por el omentum, que actuan sobre el tejido nervioso residual.