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Barium and strontium are often used as proxies of marine productivity in palaeoceanographic reconstructions of global climate. However, long-searched biological drivers for such correlations remain unknown. Here, we report that taxa within one of the most abundant groups of marine planktonic protists, diplonemids (Euglenozoa), are potent accumulators of intracellular barite (BaSO4), celestite (SrSO4), and strontiobarite (Ba,Sr)SO4. In culture, Namystinia karyoxenos accumulates Ba2+ and Sr2+ 42,000 and 10,000 times higher than the surrounding medium, forming barite and celestite representing 90% of the dry weight, the greatest concentration in biomass known to date. As heterotrophs, diplonemids are not restricted to the photic zone, and they are widespread in the oceans in astonishing abundance and diversity, as their distribution correlates with environmental particulate barite and celestite, prevailing in the mesopelagic zone. We found diplonemid predators, the filter-feeding zooplankton that produces fecal pellets containing the undigested celestite from diplonemids, facilitating its deposition on the seafloor. To the best of our knowledge, evidence for diplonemid biomineralization presents the strongest explanation for the occurrence of particulate barite and celestite in the marine environment. Both structures of the crystals and their variable chemical compositions found in diplonemids fit the properties of environmentally sampled particulate barite and celestite. Finally, we propose that diplonemids, which emerged during the Neoproterozoic era, qualify as impactful players in Ba2+/Sr2+ cycling in the ocean that has possibly contributed to sedimentary rock formation over long geological periods. IMPORTANCE We have identified that diplonemids, an abundant group of marine planktonic protists, accumulate conspicuous amounts of Sr2+ and Ba2+ in the form of intracellular barite and celestite crystals, in concentrations that greatly exceed those of the most efficient Ba/Sr-accumulating organisms known to date. We propose that diplonemids are potential players in Ba2+/Sr2+ cycling in the ocean and have possibly contributed to sedimentary rock formation over long geological periods. These organisms emerged during the Neoproterozoic era (590 to 900 million years ago), prior to known coccolithophore carbonate biomineralization (~200 million years ago). Based on reported data, the distribution of diplonemids in the oceans is correlated with the occurrence of particulate barite and celestite. Finally, diplonemids may provide new insights into the long-questioned biogenic origin of particulate barite and celestite and bring more understanding of the observed spatial-temporal correlation of the minerals with marine productivity used in reconstructions of past global climate.
- MeSH
- baryum MeSH
- minerály MeSH
- oceány a moře MeSH
- plankton MeSH
- síran barnatý * MeSH
- stroncium * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- oceány a moře MeSH
Používanie Valtrac prstenca od roku 1985 prinieslo v gastroenterochirurgii možnosť uľahčenia šitia anastomózy a skrátenie doby operácie. Ako každá metóda, aj používanie Valtrac metódy má svoje nevýhody. Autori prezentujú kazuistiku komplikácie, s ktorou sa doposiaľ v literatúre nestretli. 67ročný polymorbídny pacient po pravostrannej hemikolektómii a ileotransversoanastomóze pomocou Valtracu pre tubulárny adenokarcinóm absolvoval šeť mesiacov po operácii kontrolnú kolonoskopiu. Pri vyšetrení boli odpálené drobné polypy v sigme, colon descendens a transverze, pričom v mieste anastomózy sa našiel tkanivový pruh s ulceráciou, z ktorej bola odobratá bioptická vzorka. Následne pacient po aplikácii Fragminu mal masívnu enterorágiu, ktorá nebola zvládnutá ani opichom adrenalínu per kolonoskopiam. Pacient sa podrobil reresekcii ileotransverzoanastomózy, pričom v resekáte čreva bol nájdený prstenec tkaniva, ktorý vznikol na podklade cirkulárnej nekrózy v mieste seroserózneho spojenia biofragmentilného prstenca oboch lúmenov. V literatúre sa najčastejšie ako komplikácie po používaní Valtrac© metódy popisujú stenózy v mieste anastomózy, dehiscencie, krvácanie a fistulácia, pričom ich výskyt je porovnateľný s komplikáciami pri ručne šitých anastomózach. Napriek tomu sa dodnes všeobecne preferujú skôr ručne šité anastomózy. Túto prezentovanú extrémne vzácnu komplikáciu cirkulárnej nekrózy tkaniva v mieste seroserózneho spojenia by sme chceli dať do pozornosti všetkým chirurgom a gastroenterológom, ktorí vykonávajú endoskopické prehliadky u pacientov po týchto výkonoch.
The use of Valtrac Ring since 1985 has brought about the ability of easier anastomosis suturing and shortening of the operative treatment. As other methods, also Valtrac ring has its disadvantages. Authors present a case report of a complication previously not described in the literature. A 67 year old patient, after right hemicolectomy with ileotransversoanastomosis with the help of Valtrac due to adenocarcinoma, underwent a control colonoscopy six month after operation. Small polyps in colon sigmoideum, colon descendens and transverse were removed and a tissue stripe with ulceration was found during the examination. The bioptic sample was taken from this stripe. After the application of Fragmine, the patient had a massive enterorhagia, which was not even resolved by adrenaline per colonoscopy. The patient underwent re-resection of ileotrasversoanastomosis. A ring of tissue, created by circular necrosis in the place of seroserous connection of biofragmentile ring of both of the lumens, was found in the tissue sample. Stenosis of the anastomosis, dehiscence, bleeding and fistulation are described in the literature as the most common complications after Valtrac use. The incidence is comparable with complications during anastomosis sutured by hand. We would like to bring this extremely rare complication to the attention to all surgeons and gastroenterologists, who perform endoscopic examinations in patients after this surgical procedure.
- MeSH
- anastomóza chirurgická přístrojové vybavení škodlivé účinky MeSH
- ileum chirurgie MeSH
- kyselina polyglykolová MeSH
- lidé MeSH
- senioři MeSH
- síran barnatý škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
