Genetic and Chemical Controls of Sperm Fate and Spermatocyte Dedifferentiation via PUF-8 and MPK-1 in Caenorhabditis elegans.

Using the nematode C. elegans germline as a model system, we previously reported that PUF-8 (a PUF RNA-binding protein) and LIP-1 (a dual-specificity phosphatase) repress sperm fate at 20 °C and the dedifferentiation of spermatocytes into mitotic cells (termed "spermatocyte dedifferentiation") at 25 °C. Thus, double mutants lacking both PUF-8 and LIP-1 produce excess sperm at 20 °C, and their spermatocytes return to mitotically dividing cells via dedifferentiation at 25 °C, resulting in germline tumors. To gain insight into the molecular competence for spermatocyte dedifferentiation, we compared the germline phenotypes of three mutant strains that produce excess sperm-fem-3(q20gf), puf-8(q725); fem-3(q20gf), and puf-8(q725); lip-1(zh15). Spermatocyte dedifferentiation was not observed in fem-3(q20gf) mutants, but it was more severe in puf-8(q725); lip-1(zh15) than in puf-8(q725); fem-3(q20gf) mutants. These results suggest that MPK-1 (the C. elegans ERK1/2 MAPK ortholog) activation in the absence of PUF-8 is required to promote spermatocyte dedifferentiation. This idea was confirmed using Resveratrol (RSV), a potential activator of MPK-1 and ERK1/2 in C. elegans and human cells, respectively. Notably, spermatocyte dedifferentiation was significantly enhanced by RSV treatment in the absence of PUF-8, and its effect was blocked by mpk-1 RNAi. We, therefore, conclude that PUF-8 and MPK-1 are essential regulators for spermatocyte dedifferentiation and tumorigenesis. Since these regulators are broadly conserved, we suggest that similar regulatory circuitry may control cellular dedifferentiation and tumorigenesis in other organisms, including humans.

Hypertonic Saline for Severe Traumatic Brain Injury With Herniation: A Military Prehospital Case Report.

Severe traumatic brain injury (sTBI) is a devastating injury with limited prehospital therapies available. The Joint Trauma System (JTS) Clinical Practice Guidelines recommend hypertonic saline (HTS) for casualties with sTBI and signs of impending or ongoing herniation (IOH), but its use by combat medics has never been reported in the literature. This report details the management of a pregnant patient with sTBI and signs of IOH, including the use of HTS, by US Air Force pararescumen in an austere prehospital setting. Treatment with HTS was followed by improvement in the patient's neurologic exam and successful evacuation to definitive care where her child was delivered alive. Additionally, we review the pathophysiology and signs of herniation, the mechanism of action of hyperosmotic therapies, and the rationale behind the use of HTS in the combat setting.

Tunable near-infrared Gires-Tournois resonators based on vanadium dioxide on gold film.

Vanadium dioxide (VO2) has been proposed as a phase-change material in tunable photonic and optoelectronic devices. In such devices, a thin layer of VO2 is typically deposited on metallic or insulating surfaces. In this Letter, we report the reflectance spectra of a subwavelength structure consisting of a thin layer of VO2 deposited on a gold film in the near-infrared spectral range, particularly near the wavelength of 1550 nm, which is significant for telecommunication applications. Our results indicate that in the insulating phase of VO2, the air/VO2/Au structure can be considered as a Gires-Tournois resonant cavity whose maximum absorption wavelength can be tuned by adjusting the thickness of the VO2 layer. In contrast, in the metallic phase of VO2, the reflectance of the structure increases by an amount of the order of a few tens of units. The proposed structure can prospectively lead to new design concepts in tunable photonic and optoelectronic devices.

Use of Walking Blood Bank at Point of Injury During Combat Operations: A Case Report.

The US Military Tactical Combat Casualty Care guidelines recommend blood products as the preferred means of fluid resuscitation in trauma patients;, however, most combat units do not receive blood products prior to executing combat operations. This is largely due to logistical limitations in both blood supply and transfusion equipment. Further, the vast majority of medics are not trained in transfusion protocol. For many medics, the logistical constraints for cold-stored blood products favor the use of Walking Blood Bank (WBB), however few cases have been reported of WBB implementation at the point of injury during real world combat operations. This case report reviews one case of successful transfusion using WBB procedures at point of injury during combat. It highlights not only the feasibility, but also the necessity, for implementation of this practice on a larger scale.

The soma-germline communication: implications for somatic and reproductive aging.

Aging is characterized by a functional decline in most physiological processes, including alterations in cellular metabolism and defense mechanisms. Increasing evidence suggests that caloric restriction extends longevity and retards age-related diseases at least in part by reducing metabolic rate and oxidative stress in a variety of species, including yeast, worms, flies, and mice. Moreover, recent studies in invertebrates - worms and flies, highlight the intricate interrelation between reproductive longevity and somatic aging (known as disposable soma theory of aging), which appears to be conserved in vertebrates. This review is specifically focused on how the reproductive system modulates somatic aging and vice versa in genetic model systems. Since many signaling pathways governing the aging process are evolutionarily conserved, similar mechanisms may be involved in controlling soma and reproductive aging in vertebrates. [BMB Reports 2021; 54(5): 253-259].