[Anterior orbital ischemia secondary to type 1 cryoglobulinemia: A case report and literature review]. / Ischémie du segment antérieur de l'œil secondaire à une cryoglobulinémie de type 1 : à propos d'un cas et revue de la littérature.

INTRODUCTION: Type 1 cryoglobulinemia is characterized by a large number of clinical signs. The lack of specificity of these signs can make diagnosis difficult. Ocular manifestations are rarely described across medical literature. Only 15 cases of ophthalmological involvement secondary to cryoglobulinaemia have been reported. COMMENT: We report the case of a 69-year-old patient with cutaneous type 1 cryoglobulinaemia. He presented with bilateral anterior segment ischemia without retinal involvement with unilateral neovascularisation. Treatment of the B lymphocyte clone with rituximab and bendamustine and plasma exchange were initiated with successfully. Two similar cases describing ischaemic damage to the iris during type 1 cryoglobulinemia have been reported in the literature. CONCLUSION: Irial ischaemia should be considered as a potential in type 1 cryoglobulinaemia.

Total and dissolved phosphorus losses from agricultural headwater streams during extreme runoff events.

Eutrophication continues to be a concerning global water quality issue. Managing and mitigating harmful algal blooms demands clear information on the conditions promoting large phosphorus losses from contributing watersheds. Of particular concern is the amount and form of phosphorus loading to receiving water bodies during extreme runoff events, which are expected to increase in frequency due to climate change. Five years (2015 to 2020) of water quantity and quality data from 11 agricultural watersheds in the lower Great Lakes basin were analyzed and used to model total and dissolved phosphorus losses. This study aimed to assess temporal dynamics in phosphorus concentrations and losses over runoff events covering a wide range of hydrologic conditions and to quantify their relative importance on annual phosphorus losses. Event concentration-discharge relationships for total and dissolved phosphorus were hysteretic and had contrasting dominant patterns across watersheds. The proportion of annual phosphorus losses during events was highly variable between watersheds, accounting for 47-94 %. Extreme events were particularly impactful: as few as three events per year were found to be responsible for nearly half of total phosphorus (20-50 %) and total dissolved phosphorus (14-44 %) losses. Variability in total and dissolved phosphorus losses and concentrations over a wide range of flow conditions suggests that event magnitude is an important control on the relative mobility of particulate and dissolved phosphorus fractions. This study showed that insights into nutrient dynamics and phosphorus budgets in the lower Great Lakes basin and agriculture dominated environments more broadly can be gained by assessing event nutrient losses with respect to flow conditions and patterns in concentration-discharge relationships.

Work hours, sleep patterns and fatigue among merchant marine personnel.

A field study of work and sleep patterns among commercial merchant marine personnel is reported. Data collected over a 10-30-d period from 141 subjects aboard eight ships included information concerning work-rest schedules, sleep timing, alertness on the job and critical fatigue. The data indicate that watchstanders on the 4-on, 8-off schedule show considerable disruption in their sleep. The average sleep duration for all mariners is 6.6 h; watchstanders obtain their sleep in fragmented periods that are frequently less than 5 h in duration. Analysis of critical fatigue shows an incidence of 1-24% across personnel and measures. Of particular concern are the watchstanders on the 04.00-08.00 schedule, who sleep less than 4 h per 24-h period 22% of the time. Potential countermeasures, including changes in scheduling and staffing are proposed.

Formation of molecular iodine during oxidation of iodide by the peroxidase/H2O2 system. Implications for antithyroid therapy.

The first step in the biogenesis of thyroid hormones is the oxidation of iodides taken up by the thyroid gland. Oxidation of I- by the H2O2/peroxidase system leads to the formation of iodinium ions I+ which bond to thyroglobulin by electrophilic substitution. However, it is not clear whether I- is transformed directly to I+ or whether it passes through a molecular iodine intermediate. This latter possibility is indicated by the oxidation potentials of the reactions. I2 can be detected in vitro from the formation of I3- ions, although this has yet to be confirmed in vivo. The present study was designed to determine, albeit indirectly, whether this reaction occurs in vivo. If I2 is produced, it may form charge transfer complexes with numerous drugs. We also investigated the action of various drugs on lactoperoxidase and assessed their antithyroid activity in the rat by assay of plasma levels of T3, T4, and TSH. We found a good correlation between the value of Kc, the formation constant of the complex of the drug with molecular iodine, and the antithyroid activity in vivo. This correlation was observed in four different classes of compound. The possibility that molecular iodine is produced in the thyroid gland has implications for antithyroid therapy.