Hyperbaric oxygen effectively addresses the pathophysiology of long COVID: clinical review.

Background: The World Health Organization defines long COVID as "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation." Estimations of approximately 50 million individuals suffer from long COVID, reporting low health-related quality of life. Patients develop ongoing persistent symptoms that continue for more than 12 weeks that are not explained by another alternative diagnosis. To date, no current therapeutics are effective in treating the underlying pathophysiology of long COVID. Discussion: A comprehensive literature search using PubMed and Google Scholar was conducted and all available articles from November 2021 to January 2024 containing keywords long covid and hyperbaric oxygen were reviewed. These published studies, including case series and randomized trials, demonstrate that utilizing Hyperbaric Oxygen Therapy (HBO) provided significant improvement in patients with long COVID. Conclusion: A large cohort of patients suffer from long COVID or post-COVID-19 syndrome after recovery from their acute infection with no effective treatment options. HBO is a safe treatment and may provide benefit for this population and should continue to be researched for adjunctive treatment of long COVID.

Spatiotemporal genetic structure in a protected marine fish, the California Grunion (Leuresthes tenuis), and relatedness in the genus Leuresthes.

The genus Leuresthes displays reproductive behavior unique among marine fish in which mature adults synchronously emerge completely out of the water to spawn on beach land. A limited number of sandy beaches, which are suitable for these spawning events, are present in discontinuous locations along the geographic range of the species, potentially limiting gene flow and the degree of genetic homogeneity between intraspecific populations. Here, we tested for molecular genetic differentiation between 363 individuals, representing 3 populations of California grunion, Leuresthes tenuis, by employing 2 mitochondrial and 4 nuclear DNA markers. We include temporally diverse sampling to evaluate contemporary and temporal divergence, and we also analyze 28 individuals from one population of Gulf grunion (restricted to the Gulf of California), Leuresthes sardina, at the same markers to evaluate the molecular evidence for their separate species distinction. We find no significant differences between temporal samples, but small significant differences among all populations of L. tenuis, and unequivocal support for the separate species distinction of L. sardina. Genetic data suggest that the Monterey Bay population of L. tenuis near the species' most northern range likely represents a relatively recent colonization event from populations along the species' more traditional range south of Point Conception, California. We conclude that both the topographic features of the California and Baja California coastlines and the grunions' unique reproductive behavior have influenced the genetic structure of the populations.

Three divergent mitochondrial genomes from California populations of the copepod Tigriopus californicus.

Previous work on the harpacticoid copepod Tigriopus californicus has focused on the extensive population differentiation in three mtDNA protein coding genes (COXI, COXII, Cytb). In order to get a more complete understanding of mtDNA evolution in this species, we sequenced three complete mitochondrial genomes (one from each of three California populations) and compared them to two published mtDNA genomes from an Asian congener, Tigriopus japonicus. Several features of the mtDNA genome appear to be conserved within the genus: 1) the unique order of the protein coding genes, rRNA genes and most of the tRNA genes, 2) the genome is compact, varying between 14.3 and 14.6 kb, and 3) all genes are encoded on the same strand of the mtDNA. Within T. californicus, extremely high levels of nucleotide divergence (>20%) are observed across much of the mitochondrial genome. Inferred amino acid sequences of the proteins encoded in the mtDNAs also show high levels of divergence; at the extreme, the three ND3 variants in T. californicus showed >25% amino acid substitutions, compared with <3% amino acid divergence at the previously studied COXI locus. Unusual secondary structures make functional assignments of some tRNAs difficult. The only apparent tRNA(trp) in these genomes completely overlaps the 5' end of the 16S rRNA in all three T. californicus mtDNAs. Although not previously noted, this feature is also conserved in T. japonicus mtDNAs; whether this sequence is processed into a functional tRNA has not been determined. The putative control region contains a duplicated segment of different length (from 88 to 155 bp) in each of the T. californicus sequences. In each case, the duplicated segments are not tandem repeats; despite their different lengths, the distance between the start of the first and the start of the second repeat is conserved (520 bp). The functional significance, if any, of this repeat structure remains unknown.