(1) Introduction: is a clam found in sulfide-rich mud environments that has three hemoglobins believed to be responsible for the transport of hydrogen sulfide (HbI) and oxygen (HbII and HbIII) to chemoautotrophic endosymbionts. The physiological roles and evolution of these globins in sulfide-rich environments are not well understood. (2) Methods: We performed bioinformatic and phylogenetic analyses with 32 homologous mollusk globin sequences. Phylogenetics suggests a first gene duplication resulting in sulfide binding and oxygen binding genes. A more recent gene duplication gave rise to the two oxygen-binding hemoglobins. Multidimensional scaling analysis of the sequence space shows evolutionary drift of HbII and HbIII, while HbI was closer to the hemoglobins. Further corroboration is seen by conservation in the coding region of hemoglobins from compared to those from . (3) Conclusions: Presence of glutamine in position E7 in organisms living in sulfide-rich environments can be considered an adaptation to prevent loss of protein function. In HbI a substitution of phenylalanine in position B10 is accountable for its unique reactivity towards HS. It appears that HbI has been changing over time, apparently not subject to functional constraints of binding oxygen, and acquired a unique function for a specialized environment.
Background: Elderly patients with vestibular schwannoma (VS) are commonly observed.
Object: Retrospective analysis of 25 patients aging ≥ 70 operated on in our neurosurgical department for unilateral VS. The purpose of our study is to propose an algorithm for the treatment of VS in elderly patients.
(1) Introduction: is a clam found in sulfide-rich mud environments that has three hemoglobins believed to be responsible for the transport of hydrogen sulfide (HbI) and oxygen (HbII and HbIII) to chemoautotrophic endosymbionts. The physiological roles and evolution of these globins in sulfide-rich environments are not well understood. (2) Methods: We performed bioinformatic and phylogenetic analyses with 32 homologous mollusk globin sequences.
The studies on the L. pectinata hemoglobins (HbI, HbII, and HbIII) are essential because of their biological roles in hydrogen sulfide transport and metabolism. Variation in the pH could also play a role in the transport of hydrogen sulfide by HbI and oxygen by HbII and HbIII, respectively.
Hemoglobin III (HbIII) is one of the two oxygen reactive hemoproteins present in the bivalve, Lucina pectinata. The clam inhabits a sulfur-rich environment and HbIII is the only hemoprotein present in the system which does not yet have a structure described elsewhere. It is known that HbIII exists as a heterodimer with hemoglobin II (HbII) to generate the stable Oxy(HbII-HbIII) complex but it remains unknown if HbIII can form a homodimeric species.
Koos grade IV vestibular schwannomas (VS) (maximum diameter > 3 cm) compress the brainstem and displace the fourth ventricle. Microsurgical resection with attention to the right balance between preservation of function and maximal tumor removal is the treatment of choice. Our series consists of 60 consecutive patients with unilateral VS, operated on from December 2010 to July 2019.
