Background The hyaluronidase enzyme is generally known as a spreading factor in animal venoms. Although its activity has been demonstrated in several organisms, a deeper knowledge about hyaluronidase and the venom spreading process from the bite/sting site until its elimination from the victim's body is still in need. Herein, we further pursued the goal of demonstrating the effects of inhibition of T . serrulatus venom (TsV) hyaluronidase on venom biodistribution. Methods and principal findings We used technetium-99m radiolabeled Tityus serrulatus venom ( 99m Tc-TsV) to evaluate the venom distribution kinetics in mice. To understand the hyaluronidase’s role in the venom’s biodistribution, 99m Tc-TsV was immunoneutralized with specific anti- T . serrulatus hyaluronidase serum. Venom biodistribution was monitored by scintigraphic images of treated animals and by measuring radioactivity levels in tissues as heart, liver, lungs, spleen, thyroid, and kidneys. In general, results revealed that hyaluronidase inhibition delays venom components distribution, when compared to the non-neutralized 99m Tc-TsV control group. Scintigraphic images showed that the majority of the immunoneutralized venom is retained at the injection site, whereas non-treated venom is quickly biodistributed throughout the animal’s body. At the first 30 min, concentration peaks are observed in the heart, liver, lungs, spleen, and thyroid, which gradually decreases over time. On the other hand, immunoneutralized 99m Tc-TsV takes 240 min to reach high concentrations in the organs. A higher concentration of immunoneutralized 99m Tc-TsV was observed in the kidneys in comparison with the non-treated venom. Further, in situ neutralization of 99m Tc-TsV by anti- T . serrulatus hyaluronidase serum at zero, ten, and 30 min post venom injection showed that late inhibition of hyaluronidase can still affect venom biodistribution. In this assay, immunoneutralized 99m Tc-TsV was accumulated in the bloodstream until 120 or 240 min after TsV injection, depending on anti-hyaluronidase administration time. Altogether, our data show that immunoneutralization of hyaluronidase prevents venom spreading from the injection site. Conclusions By comparing TsV biodistribution in the absence or presence of anti-hyaluronidase serum, the results obtained in the present work show that hyaluronidase has a key role not only in the venom spreading from the inoculation point to the bloodstream, but also in venom biodistribution from the bloodstream to target organs. Our findings demonstrate that hyaluronidase i...

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Evanguedes Kalapothakis (2019) Complete mitochondrial genome sequence of Hypostomusfrancisci (Siluriformes: Loricariidae), Mitochondrial DNA Part B, 4:1, 155-157, ABSTRACTHypostomus francisci, commonly known as "cascudo", is a fish of ecological importance found in the upper São Francisco River, Minas Gerais, Brazil. Here we present the complete mitogenome (mtDNA) of H. francisci. The whole molecule is 16,541 bp long and contains 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes, and one control region (D-loop). All the PCGs in the H. francisci mtDNA use the standard ATG start codon, except for Cox1, which utilizes GTG. Seven of the 13 PCGs contain TAA stop codons, three contain a TAG, and three contain the incomplete stop codons TA À or TÀ. ARTICLE HISTORY

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Myrmecophaga tridactyla, popularly known as giant anteater, is a member of Xenarthra magnorder which is under the threat of extinction. Herein, we describe the complete mitochondrial genome of M. tridactyla. The circular DNA molecule is 16,546 bp long, contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a non-coding Control Region of 1110 bp. All protein-coding genes are on the heavy strand, except for Nd6. Ten of the 13 PCGs contained an ATG start codon.