NO- and H2S- releasing nanomaterials: A crosstalk signaling pathway in cancer.

The gasotransmitters nitric oxide (NO) and hydrogen sulfide (H2S) play important roles not only in maintaining physiological functions, but also in pathological conditions and events. Importantly, these molecules show a complex interplay in cancer biology, demonstrating both tumor-promoting and anti-tumor activities depending on their concentration, flux, and the environmental redox state. Additionally, various cell types respond differently to NO and H2S. These gasotransmitters can be synergistically combined with traditional anticancer treatments such as radiotherapy, immunotherapy, chemotherapy, and phototherapy. Notably, NO, and more recently H2S, have been shown to reverse multidrug resistance. Nanomaterials to deliver NO donors and, to a lesser extent, H2S donors, have emerged as a promising approach for targeted delivery of these gasotransmitters. Nanotechnology has advanced the delivery of anticancer drugs, enhancing efficiency and reducing side effects on non-cancerous cells. This review highlights recent progress in the design of NO and H2S-releasing nanomaterials for anticancer effects. It also explores the interactions between NO and H2S, which are crucial for developing combined therapies and nanomedicines with minimal side effects.

A new species of long-tailed shrew of the genus Sorex (Eulipotyphla: Soricidae) from Sierra de Omoa, Honduras.

The only known species of the genus Sorex in Honduras is Sorex mccarthyi Matson Ordóñez-Garza, which is endemic to Celaque National Park. This species shows the presence of a postmandibular foramen and canal, a characteristic that is useful to distinguish between species south of the Isthmus of Tehuantepec and unique to the Sorex salvini species group. Recently, two specimens of Sorex were collected in 2018 at Cusuco National Park, northwestern Honduras. These specimens lack the distinctive characteristics possessed by the S. salvini species group and belong to the Sorex veraepacis species group. Previously, the S. veraepacis species group was only known from the highlands of the southern Mexican state of Chiapas and Guatemala. Principal component analysis shows that specimens from Sierra de Omoa are different in size and shape with respect to other known species (i.e., S. veraepacis Alston, S. ibarrai Matson McCarthy and S. madrensis Matson Ordóñez-Garza). We describe these two specimens, currently known only from an isolated cloud forest in the Sierra de Omoa, Honduras, as a new species.

The taxonomic status of Long-tailed shrews (Mammalia: genus Sorex) from Nuclear Central America.

We examined 256 specimens of long-tailed shrews (Sorex) from 53 localities throughout the highlands of Nuclear Central America. We evaluate the efficacy of using three qualitative characteristics to identify populations of Sorex from Nuclear Central America: 1) the presence or the absence of a postmandibular foramen and canal; 2) relative size of U3 compared to U4; and, 3) the presence or absence of a pigmented ridge on the lingual side of each unicuspid tooth. In our data, the first character is invariable for the specimens we examined. Two species groups can be recognized based on the presence (S. salvini species group) or the absence of a postmandibular foramen and canal (S. veraepacis species group). The other two characteristics were useful, but not diagnostic. Based upon Principal Component Analysis we recognize nine species of Sorex in Nuclear Central America. Five species belong to the S. salvini species group: S. cristobalensis, S. salvini, S. sclateri, S. stizodon, and a new species from Honduras. Four species belong to the S. veraepacis species group: S. chiapensis, S. ibarrai, S. veraepacis, and a new species from western Guatemala. We also present evidence that the type locality (Cobán, Alta Verapaz, Guatemala) for S. veraepacis is not correct.