Recreational and occupational field exposure to freshwater cyanobacteria – a review of anecdotal and case reports, epidemiological studies and the challenges for epidemiologic assessment

Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms are most frequently reported. Some papers give convincing descriptions of allergic reactions while others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A coroner in the United States found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond. This death is the first recorded human fatality attributed to recreational exposure to cyanobacteria, although uncertainties surround the forensic identification of the suspected cyanotoxin in this case. We systematically reviewed the literature on recreational exposure to freshwater cyanobacteria. Epidemiological data are limited, with six studies conducted since 1990. Statistically significant increases in symptoms were reported in individuals exposed to cyanobacteria compared to unexposed counterparts in two Australian cohort studies, though minor morbidity appeared to be the main finding. The four other small studies (three from the UK, one Australian) did not report any significant association. However, the potential for serious injury or death remains, as freshwater cyanobacteria under bloom conditions are capable of producing potent toxins that cause specific and severe dysfunction to hepatic or central nervous systems. The exposure route for these toxins is oral, from ingestion of recreational water, and possibly by inhalation. A range of freshwater microbial agents may cause acute conditions that present with features that resemble illnesses attributed to contact with cyanobacteria and, conversely, acute illness resulting from exposure to cyanobacteria or cyanotoxins in recreational waters could be misdiagnosed. Accurately assessing exposure to cyanobacteria in recreational waters is difficult and unreliable at present, as specific biomarkers are unavailable. However, diagnosis of cyanobacteria-related illness should be considered for individuals presenting with acute illness following freshwater contact if a description is given of a waterbody visibly affected by planktonic mass development

Accumulation of trace elements in cattle from rural and industrial areas in Belgium.

&lt;p&gt;Trace element concentrations were determined in meat, kidney and liver tissue of cattle, which had resided more than 18 months in areas historically contaminated by emissions from the non-ferrous metal industry or in regions with normal background metal contamination levels in Belgium. Trace element levels were determined by inductively coupled plasma-mass spectrometry. Lead, arsenic and cadmium concentrations in meat were low for all cattle. Concentrations in kidneys were, respectively, 1.8-, 2.2- and 2.5-fold higher in cattle from the contaminated areas compared to animals from reference areas. The European maximum level for cadmium in kidney was exceeded by 75% of the kidneys from contaminated areas and 47% of the kidneys from reference areas. Lead, arsenic and cadmium concentrations in bovine livers from contaminated areas were increased by a factor of 2.3. Zinc levels in livers and kidneys were within normal ranges, but 20% higher in the contaminated areas compared to reference areas. Copper levels in livers were high in all areas. Dairy cattle accumulated significantly higher levels of cadmium in kidneys and of lead in liver and kidneys than did beef cattle.&lt;/p&gt;</p

When fathers make the difference: efficacy of male sexually selected antimicrobial glands in enhancing fish hatching success

1. Egg and offspring resistance to pathogens is a major determinant of survival and has been mainly ascribed to maternal factors. However, paternal production of antimicrobials was recently suggested to increase offspring survival in species where males perform egg care. 2. In the peacock blenny, Salaria pavo, a demersal spawning species where males exhibit a pair of anal glands producing lysozyme-like compounds, we tested the antimicrobial activity and the egg protection efficacy of these glands. The anal gland secretion (AGS) has an inhibitory effect on the growth of both Gram-negative and Gram-positive bacteria, including those causing the most severe fish diseases in marine culture. The egg clutches cared for by males deprived of anal glands have a significantly lower survival rate than those cared for by sham-operated males and non-viable eggs showed clear signs of bacterial infection. 3. Anal gland secretion production and its protein content are proportional to gland size. In species where male parental care plays a crucial role in offspring survival, females are expected to assess mates selecting those traits that are reliably associated with parental ability. Hence, we experimentally challenged females with dummy males differing in anal gland size. Females definitely preferred dummy males with larger anal glands, suggesting that their choice is driven by the pursuit of direct fecundity benefits. 4. These findings indicate that antimicrobial production is a crucial component of male parental care. The contribution of antimicrobials to male performance as fathers suggests that the development of traits devoted to this function may influence male attractiveness and be sexually selected

A possible strategic role of air during pars plana vitrectomy for macula-involving rhegmatogenous retinal detachment

Aim: To evaluate the advantages and safety of vitrectomy under air for treating macula-involving rhegmatogenous retinal detachment (RRD). Methods: Consecutive patients with macula-involving RRD who underwent vitrectomy under air were recruited. Demographic and clinical data were: age, gender, eye, lens status, best corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution (logMAR), axial length, intraocular pressure (IOP). RRD parameters were: RRD extent, retinal breaks number. Surgical data were: cataract surgery, tamponade used. Postoperative parameters were: BCVA, IOP at first, third, sixth\ua0month, recurrent RD, incidence of retinal folds, subretinal fluid (SRF) persistence, macular displacement. Results: Seventy-one eyes (71 patients) were recruited. Cataract surgery was performed in 32 of 45 phakic\ua0patients. The tamponade used was: sulfur hexafluoride 18% (41), silicon oil (SO) (26), high-density SO (4). BCVA improved significantly from baseline (1.2 \ub1 0.4 logMAR) to the last control (0.8 \ub1 0.7 logMAR) (P = 0.03285). Recurrent RD incidence was 14.1%. Postoperative complications were: retinal folds (2), SRF persistence (3), macular displacement (2). Conclusion: Vitrectomy under air is a safe alternative technique for treating macula-involving RRD. Vitrectomy under air allows surgeon to remove accurately the vitreous from the peripheral retina and facilitates the removal of SRF reducing the complications related to its postoperative persistence