Marine microdebris pollution in sediments from three environmental coastal areas in the southwestern Argentine Atlantic.

Microplastics (MPs) and antifouling paint particles (APPs) are important components of marine microdebris (MDs), which constitute a potential environmental risk. This study analyzed baseline contamination levels of MDs and mesodebris (MesDs) in intertidal sediments at different depths, exploring the geomorphological influence in three Argentine coastal environments: Bahía Blanca Estuary (BBE), Los Pocitos (LP) and Puerto Madryn (PM). The MDs and MesDs samples were characterized by µ-FTIR, SEM/EDX and XRD. The abundance of MPs and APPs in sediments, range between 19.78 and 1087.19 and between 0 and 172.93 items/kg d.w., respectively. Despite variations in population and industrial developments in these areas, MPs abundance shows no significant differences in low and high intertidal zones. However, mean MPs concentrations were higher in the surface layer (0-5 cm) compared to the deeper sediments (5-10 cm), indicating recent MPs deposition. Chemical characterization evidenced the presence of cellulose (CE) and denser polymers as acrylonitrile butadiene styrene (ABS) and polyacrylics (PAN), APPs, metallic and black MDs. Surface degradation and heavy metals (Zn, Cr, and Ba) were also detected in APPs and other MDs, either as additives or adhered to their surfaces. Changes in crystallinity were also observed on the MesDs due to weathering. The calculated polymer hazard index (PHI) and the presence of hazardous polymers such as ABS and PAN indicated an increased risk of MPs pollution on the BBE and PM coasts. The pollution load index (PLI) values (from 4.63 to 5.34) suggested unpolluted to moderately polluted levels. These findings offer insights into potential risks associated with MDs in Argentine intertidal sediments, underscoring the critical need to comprehend the geomorphology and the influence of coastal dynamics. This is crucial for effectively addressing challenges linked to MDs pollution guiding the development of robust management and mitigation strategies.

Assessment of the physicochemical conditions sediments in a polluted tidal flat colonized by microbial mats in Bahía Blanca Estuary (Argentina).

The aim of this work is to assess the physicochemical conditions of the supratidal sediments colonized by microbial mats at two sites from Rosales Harbor (Bahía Blanca Estuary, Argentina) close to sewage discharge. Both sites differed in the size grain. No differences in pH, Eh and temperature were observed. Moisture retention and chlorophyll a concentration were significantly different between sites and sediment layers. Heavy metals and organic matter content were significantly higher in SII. No statistical differences were found in porewater nutrients concentration, being higher in SI (except DSi). The presence of Escherichia coli in water and sediment (1000 CFU/100 mL - uncountable and 35-40 CFU g(-1) dw, respectively) evidenced microbial contamination in the study area. The relationships between the physicochemical parameters evaluated and the influence of the sewage discharge allow defining two different areas in the Rosales Harbor despite the proximity and the presence of microbial mats.

Primary blast lung injury at a NATO Role 3 hospital.

BACKGROUND: Primary blast lung injury (PBLI) is defined as lung contusion from barotrauma following an explosive mechanism of injury (MOI). Military data have focused on PBLI characteristics following evacuation from the combat theatre; less is known about its immediate management and epidemiology in the deployed setting. We conducted a quality improvement project to describe the prevalence, clinical characteristics, management strategies and evacuation techniques for PBLI patients prior to evacuation. METHODS: Patients admitted to a Role 3 hospital in southwest, Afghanistan, from January 2008 to March 2013 with a blast MOI were identified through the Department of Defense Trauma Registry; International Classification of Diseases 9 codes and patient record review were used to identify the PBLI cohort from radiology reports. Descriptive statistics and Fishers exact test were used to report findings. RESULTS: Prevalence of PBLI among blast injured patients with radiology reports was 11.2% (73/648). The population exhibited high Injury Severity Scores median 25 (IQR 14-34) and most received a massive blood transfusion (mean 33.4±38.3 total blood products/24 h). The mean positive end expiratory pressure (PEEP) requirement was 6.2±3.7 (range 5-15) cm H2O and PaO2 to FiO2 ratio was 297±175.2 (66-796) mm Hg. However, 16.6% of patients had a PaO2 to FiO2 ratio <200, 13.3% required PEEP ≥10 cm H2O and one patient required specialised evacuation for respiratory failure. A dismounted MOI (72.8%) and evacuation from point of injury by the Medical Emergency Response Team (62.3%) appeared to be associated with worse lung injury. Only eight of the 73 PBLI patients died and of the five with retrievable records, none died from respiratory failure. CONCLUSIONS: PBLI has a low prevalence and conventional lung protective ventilator management is generally appropriate immediately after injury; application of advanced modes of ventilation and specialised evacuation assistance may be required. PBLI may be a marker of underlying injury severity since all deaths were not due to respiratory failure. Further work is needed to determine exact MOI in mounted and dismounted casualties.

Evidence of a bradykinin B1 receptor in human ileum: pharmacological comparison to the rabbit aorta B1 receptor.

Bradykinin B1 receptors have been identified in a limited number of human tissues and may have implications in pathological states of chronic inflammation. In the present study, longitudinal strips of postmortem human ileum displayed a strong contractile response to the B2 receptor agonist, bradykinin (EC50 = 7.0 nM). Noninduced ileum strips contracted only to high concentrations (1 and 10 microM) of the B1 receptor agonists, des-Arg9-BK and Lys0des-Arg9-BK. After incubation overnight at 37 degrees C the potency of des-Arg9-BK and Lys0des-Arg9-BK dramatically increased (EC50 = 183 and 13.2 nM, respectively). The increase in B1 agonist potency was inhibited by the protein synthesis inhibitor, puromycin. Similarly, rabbit aorta strips displayed a protein synthesis-dependent induction of the B1 agonist response. Incubated human ileum and rabbit aorta exhibited a reproducible response to des-Arg9-BK over time, whereas responses to Lys0des-Arg9-BK were not reproducible, having reduced potency and magnitude over time. Lys0[Leu8]des-Arg9-BK was a more potent antagonist at the B1 receptor in both tissues compared with [Leu8]des-Arg9-BK. The B2 antagonist, HOE-140, was a very weak inhibitor of the B1 response in human ileum and inactive in rabbit aorta. In conclusion, incubation of isolated human ileum overnight induces expression of a B1 receptor through a mechanism that depends on de novo protein synthesis. The potency profile of selected B1 agonists and antagonists indicates pharmacological similarities between the inducible B1 receptor in both the human ileum and rabbit aorta.

Bradykinin receptor antagonists containing N-substituted amino acids: in vitro and in vivo B(2) and B(1) receptor antagonist activity.

We report a systematic probing of the structural requirements of the bradykinin (BK) type 2 (B(2)) receptor for antagonist activity by incorporating N-alkyl-amino acid residues at positions 7 and 8 of a potent antagonist sequence. Compound 1 (D-Arg(0)-Arg(1)-Pro(2)-Hyp(3)-Gly(4)-Thi(5)-Ser(6)-D-Tic(7)-N-Chg (8)-Arg(9), CP-0597)(1,2) is a potent (pA(2) = 9.3, rat uterus; pK(i) = 9.62, binding, human receptor clone) B(2) receptor antagonist devoid of in vitro B(1) antagonist activity (rabbit aorta). Compound 1 exhibits high potency (ED(50) = 29.2 pmol/kg/min, iv, rabbit) and duration of action when tested in models for in vivo B(2) antagonist activity. Although devoid of activity in a classic B(1) isolated tissue assay, B(1) antagonist activity for 1 was demonstrated in vivo, in a LPS-treated, inducible BK(1) receptor rabbit blood pressure model (ED(50) = 1.7 nmol/kg/min). D-Arg(0) of 1 can be formally replaced by an achiral arginine surrogate, without significant loss in antagonist potency on rat uterus (compound 11, B(2) pA(2) = 9.1). Antagonist 13 (Hyp(2), Nchg(8)), pK(i) = 10.2, and agonist 4 (N-methylcyclohexyl-Gly(8)), pK(i) = 10.1, also exhibited substantial binding to guinea pig ileum membrane receptors as well as a human B(2) receptor clone. Very minor structural changes in the N-alkyl amino acid residues in positions 7 and 8 can modify the activity of this class of compounds from being extremely potent antagonists to tight binding partial or full agonists. These studies have resulted in a series of compounds containing inexpensive amino acid residues but which produce broad spectrum BK receptor blocking potency and exceptional in vivo duration of action.