Total and methyl mercury distribution in water, sediment, plankton and fish along the Tapajós River basin in the Brazilian Amazon

Mercury (Hg) is known as one of the major contaminants in the Amazon. The Tapajós River basin, in the Brazilian Amazon, has diverse anthropogenic activities which increase Hg concentrations in the aquatic ecosystem. Moreover, high concentrations of Hg are naturally found in this basin. Distribution of total (THg) and methyl (MeHg) mercury were assessed in unfiltered water (n = 47), suspended particulate matter (SPM, n = 30), superficial sediment (BS, n = 29), plankton (n = 28) and fishes (n = 129) from the Tapajós River basin. Suspended particles were the main carrier of Hg in the water column and sediment. Increased erosion, prompted by anthropic activities, led to higher Hg concentrations in water from the most impacted areas. Hg is transported mainly in particulate matter; thus, anthropic disturbances influence Hg concentrations downstream. Limnological parameters such as organic matter content influenced MeHg concentrations in water, plankton and sediment of the Tapajós basin. Hg methylation in total plankton was more efficient in lakes (13-66%) than in Tapajós River main channel (2-14%). Biotic and abiotic factors interact in a complex way in the aquatic ecosystem, making Hg concentrations to vary in food web. Gold mining and deforestation probably increase Hg levels in the Tapajós basin. Thus, in addition to Hg monitoring, prevention and remediation efforts should be focused on soil and sediment erosion control.

Gastrointestinal mucosal damage in patients with COVID-19 undergoing endoscopy: an international multicentre study

BACKGROUND

Although evidence suggests frequent gastrointestinal (GI) involvement during coronavirus disease 2019 (COVID-19), endoscopic findings are scarcely reported.

AIMS

We aimed at registering endoscopic abnormalities and potentially associated risk factors among patients with COVID-19.

METHODS

All consecutive patients with COVID-19 undergoing endoscopy in 16 institutions from high-prevalence regions were enrolled. Mann-Whitney U, χ2 or Fisher's exact test were used to compare patients with major abnormalities to those with negative procedures, and multivariate logistic regression to identify independent predictors.

RESULTS

Between February and May 2020, during the first pandemic outbreak with severely restricted endoscopy activity, 114 endoscopies on 106 patients with COVID-19 were performed in 16 institutions (men=70.8%, median age=68 (58-74); 33% admitted in intensive care unit; 44.4% reporting GI symptoms). 66.7% endoscopies were urgent, mainly for overt GI bleeding. 52 (45.6%) patients had major abnormalities, whereas 13 bled from previous conditions. The most prevalent upper GI abnormalities were ulcers (25.3%), erosive/ulcerative gastro-duodenopathy (16.1%) and petechial/haemorrhagic gastropathy (9.2%). Among lower GI endoscopies, 33.3% showed an ischaemic-like colitis.Receiver operating curve analysis identified D-dimers >1850 ng/mL as predicting major abnormalities. Only D-dimers >1850 ng/mL (OR=12.12 (1.69-86.87)) and presence of GI symptoms (OR=6.17 (1.13-33.67)) were independently associated with major abnormalities at multivariate analysis.

CONCLUSION

In this highly selected cohort of hospitalised patients with COVID-19 requiring endoscopy, almost half showed acute mucosal injuries and more than one-third of lower GI endoscopies had features of ischaemic colitis. Among the hospitalisation-related and patient-related variables evaluated in this study, D-dimers above 1850 ng/mL was the most useful at predicting major mucosal abnormalities at endoscopy.

TRIAL REGISTRATION NUMBER

ClinicalTrial.gov (ID: NCT04318366).

Mercury and selenium in fishes from the Tapajós River in the Brazilian Amazon: An evaluation of human exposure

This work aimed to evaluate associated risks of fish consumption to human health, concerning mercury (Hg) and selenium (Se) concentrations in fish species largely consumed in the Tapajós River basin in the Brazilian Amazon. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in 129 fish specimens from four sites of the Tapajós River basin. Estimated daily intake (EDI) of Hg and Se were reported regarding fish consumption. EDI were compared with the reference value of provisional tolerable daily intake proposed by the World Health Organization (WHO). Se:Hg ratios and selenium health benefit values (Se HBVs) seem to offer a more comprehensive fish safety model. THg concentrations in fishes ranged from 0.03 to 1.51 μg g^-1 of wet weight (w.w.) and MeHg concentrations ranged from 0.02 to 1.44 μg g^-1 (w.w.). 80% of the samples were below the value of Hg recommended by the WHO for human consumption (0.5 μg g^-1 w.w.). However, Hg EDI exceeded the dose suggested by the United States Environmental Protection Agency (0.1 μg kg^-1 day^-1), due to the large level of fish consumption in that area. Se concentrations in fishes ranged from 0.02 to 0.44 μg g^-1 w.w. An inverse pattern was observed between Hg and Se concentrations in the trophic chain (highest levels of Se in the lowest trophic levels). The molar ratio Se:Hg and Se HBVs were higher in iliophagous and herbivorous fishes, which is noteworthy to reduce toxic effects of Hg contamination. For planktivores, the content of Se and Hg was almost equimolar. Carnivorous fishes - with the exception of Hemisorubim platyrhynchos and Pseudoplatystoma fasciatum -, showed Se:Hg ratios <1. Thus, they do not act as a favorable source of Se in the diet. Therefore, reduced intake of carnivorous fishes with preferential consumption of iliophages, herbivores and, to some extent, even planktivores should be promoted as part of a healthier diet.

Metal bioaccumulation in consumed marine bivalves in Southeast Brazilian coast

This work aimed to investigate metal bioaccumulation by mussels (Perna perna) and Lion's Scallop (Nodipecten nodosus) farmed in tropical bays, in order to estimate spatial and temporal variation in the exposure to these elements, as well as human health risk. The concentration of each measured element was considered for this evaluation, using maximum residue level (MRL) in foods established by the Brazilian (ANVISA), American (USFDA) and European Communities (EC) legislations. Values for estimated daily ingestion (EDI) were determined for metals intake through mussel and scallop consumption. These estimates were compared with the reference value of (PTDI) proposed by World Health Organization (WHO). Trace elements concentration was measured on ninety mussels P. perna (tissue) and ninety Lion's Scallop N. nodosus (muscle and gonad) reared in four different tropical areas of the Southeast Brazilian coast, between 2009 and 2010. Zinc (Zn), Iron (Fe), Copper (Cu), Manganese (Mn), Chrome (Cr), Nickel (Ni), Cadmium (Cd) and Lead (Pb) concentrations were measured by flame atomic absorption spectrometry after acid mineralization. Cd and Mn were more efficiently bioaccumulated by scallops than mussels and the opposite was found for Fe, Cu and Ni. Guanabara Bay and Sepetiba Bay were considered the most impacted between ecosystems studied. Higher Cd values in Arraial do Cabo in the other sites studied were associated with upwelling that occurs in the region. Consumption of both species cannot be considered safe, because the Cu and Cr concentrations, in accordance with the limits established by the Brazilian Agency (ANVISA). On the other hand, any EDI value exceeded the corresponding value of the PTDI, proposed by World Health Organization (WHO).

Laser radiation and motility patterns of human sperm

Human sperm were exposed in vitro to laser radiation. An increase in progressive sperm motility was associated with a faster rate of sperm ATP consumption. Computer-assisted analysis of sperm motility confirmed the positive effect of laser irradiation on velocity and linearity of sperm.

Squamous cell carcinoma arising in hidradenitis suppurativa

The case reported concerns a 57-year-old man with a 35-year history of hidradenitis suppurativa lesions confined to his buttocks and recently complicated by a large, ulcerated, well-differentiated squamous cell carcinoma. Wide surgical excision and grafting, requiring temporary colostomy, were performed with no recurrence or metastasis during the following 12 months. The relevant literature is reviewed and discussed.

Morphological and molecular identification of the fish-borne metacercaria of Ascocotyle (Phagicola) longa Ransom, 1920 in Mugil liza from Argentina

This is the first report of Ascocotyle (Phagicola) longa Ransom, 1920 (Digenea: Heterophyidae) in Argentina confirmed by morphological and molecular studies. The metacercaria was found encysted in myotomal musculature, heart and mesentery of the mullet Mugil liza (Pisces: Mugilidae) from Samborombon bay. We provide a morphological description of the metacercaria which we identified using species-specific primers for A. (Phagicola) longa and nucleotid sequence. This worldwide parasite has been reported as one of the causative agents of heterophyiosis, an emerging fish-borne disease of humans, contracted by the consumption of raw mullet. The discovery of A. (Phagicola) longa in Argentina represents a warning of the potentially great impact of this parasite on public health.

[Psycho-functional changes in attention and learning under the action of L-acetylcarnitine in 17 young subjects. A pilot study of its use in mental deterioration]

The aim of the study was the investigation of the ability of L-acetylcarnitine (Acn; 1.5 g daily oral route for 1 month) to enhance some performances requiring a high level of attention and reflex velocity. The sample includes 17 healthy subjects, 8 males and 9 females, 22 to 27 years old; 10 of the subjects practice sports at agonistic level, while 7 have a sedentary life style. Reflexes have been measured, baseline and after 17 and 30 days of Acn administration, through a purposely constructed reflex-meter able to determine the latency (csec) of the reaction to an auditory stimulus. The ability as well as the time of learning was determined, before and after treatment, as the time and the number of errors to get out of the maze of a videogame (the test was also carried out by an untreated control group). Acn seems to induce an enhancement of reflex velocity, with complete annulment of the difference between the dominant and the opposite hand, as well as a significant reduction (3 to 4 times superior to controls) of both the errors and the time with the maze test.

[Anxiety and ++phobia in dental patients. Recent findings regarding the "fear of the dentist"]

The authors review the most recent literature on "dental phobia" which is responsible for discomfort and delays in prevention and treatment of odontoiatric disorders. Special attention is devoted to the multifactorial etiology and to diagnostic classification of these difficulties, as well as to the therapeutic possibilities available today.

[Which physical tests for which objectives in pulmonary rehabilitation?]

Chronic respiratory disease is a major cause of morbidity and mortality worldwide and an important cause of disability including a reduction of exercise, functional and muscle capacity contributing to a decreased quality of life. In the context of pulmonary rehabilitation, a thorough patient-centered outcome assessment, including not only measures of lung function, but also exercise functional and muscle capacity, is imperative for a comprehensive disease management. Assessment of these impairments and dysfunctions with appropriate and change-sensitive procedures is thus necessary for personalizing the physical interventions and assessing the short- and long-term effectiveness of the intervention. The clinician currently has a wide variety of tests and measurements available to assess the physical and functional capacity of people with chronic respiratory disease. The aim of this review is to provide a pragmatic synthesis of the physical, functional and muscle capacity tests most commonly used in pulmonary rehabilitation. Ultimately, it should help the clinician to identify the relevant evaluations according to the objectives of the patients but also according to the available resources, the setting of pulmonary rehabilitation and the specific qualities of each test.