Search

Excessive sweating or focal hyperhidrosis (HH) of the residual limb in persons with amputations is thought to be a significant contributor to residual limb dermatoses, prosthesis dysfunction, and decreased quality of life. Treatment algorithms used for HH in persons without amputation do not effectively translate to residual limb HH, and research in this area is sparse. We discuss the long-term outcomes of three patients treated with microwave thermoablation (MT) on their residual limbs who had previously been unsuccessfully managed with topical antiperspirants and botulinum toxin injections. On average, there was a decrease of two points in the Hyperhidrosis Severity Scale score among the three patients 4-6 years after treatment. Although the reported side effects of post-procedure edema and prolonged time out of a prosthesis are challenging, MT of the residual limb appears to be a promising treatment modality for persons with amputation. Further investigations for standardized treatment guidelines are required to improve management of residual limb HH with MT.

As a response to the COVID-19 pandemic, many institutions transitioned to online learning or participation in telehealth as a substitute for clinical rotations. The Uniformed Services University of the Health Sciences (Bethesda, Maryland) relied heavily on e-learning during this time as an alternative means for meeting educational objectives. We report the positive results of a prospective study evaluating short-term information recall and comprehension as well as students' confidence in their ability to apply course objectives over 3 months of an online distance learning (DL) dermatology course.

Amputees face many challenges associated with residual limbs. Overall, amputees have an increased risk for skin disease occurring at residual limb sites. Although prosthetists and primary care physicians often accomplish routine care, the dermatologist plays a very important role within the multidisciplinary team. Many military dermatologists have unique clinical experience treating amputees, as a portion of their practice consists of providing care to soldiers with traumatic amputations from complex and dramatic blast injuries. Although current therapies and preventative treatments are for the most part successful, future research involving advanced technology is promising.

According to the Centers for Disease Control's recently devised National Strategy for Combating Antibiotic-Resistant Bacteria, Acinetobacter baumannii is a "serious" threat level pathogen. A. baumannii's notoriety stems from the fact that a large number of modern strains are multidrug resistant and persist in the hospital setting, thus causing numerous deaths per year. It is imperative that research focus on a more fundamental understanding of the factors responsible for the success of A. baumannii. Toward this end, our group investigated virulence gene expression patterns in a recently characterized wound isolate, AB5075, using quantitative real-time polymerase chain reaction array. Notably, several genes showed statistically significant upregulation at 37°C compared to 25°C; MviM, Wbbj, CarO, and certain genes of the Bas, Bar, and Csu operons. Additionally, we found that in vitro biofilm formation by Csu transposon insertion mutant strains is attenuated. These findings validate previous reports that suggest a link between the Csu operon and biofilm formation. More importantly, our results demonstrate a successful method for evaluating the significance of previously identified virulence factors in a modern and clinically relevant strain of A. baumannii, thereby providing a path toward a more fundamental understanding of the pathogenicity of A. baumannii.

Structures formed by human telomere sequence (HTS) DNA are of interest due to the implication of telomeres in the aging process and cancer. We present studies of HTS DNA folding in an anhydrous, high viscosity deep eutectic solvent (DES) comprised of choline choride and urea. In this solvent, the HTS DNA forms a G-quadruplex with the parallel-stranded ("propeller") fold, consistent with observations that reduced water activity favors the parallel fold, whereas alternative folds are favored at high water activity. Surprisingly, adoption of the parallel structure by HTS DNA in the DES, after thermal denaturation and quick cooling to room temperature, requires several months, as opposed to less than 2 min in an aqueous solution. This extended folding time in the DES is, in part, due to HTS DNA becoming kinetically trapped in a folded state that is apparently not accessed in lower viscosity solvents. A comparison of times required for the G-quadruplex to convert from its aqueous-preferred folded state to its parallel fold also reveals a dependence on solvent viscosity that is consistent with Kramers rate theory, which predicts that diffusion-controlled transitions will slow proportionally with solvent friction. These results provide an enhanced view of a G-quadruplex folding funnel and highlight the necessity to consider solvent viscosity in studies of G-quadruplex formation in vitro and in vivo. Additionally, the solvents and analyses presented here should prove valuable for understanding the folding of many other nucleic acids and potentially have applications in DNA-based nanotechnology where time-dependent structures are desired.

Structures formed by human telomere sequence (HTS) DNA are of interest due to G-quadruplex forming HTS DNA that has recently generated a tremendous interest due to its involvement in aging process and cancer. The present study examines HTS in anhydrous, exceptionally viscous deep eutectic solvent (DES), comprised of choline, chloride, and urea. Under these conditions, HTS adopts an extremely stable “parallel-propeller” form of G-quadruplex, consistent with the previously observed effects of diminished water activity. Additionally, the high solvent friction of DES slows the dynamics of HTS folding on the order of months, as opposed to milliseconds in aqueous solution, and allows the entrapment of kinetic intermediates. Moreover, analogous transition studies of the quadruplex converting from the aqueous buffer structure to the parallel form in 90% DES (w/v) and 40% PEG 200 (v/v) differ from hours to days scaling inversely with viscosity ∼ 1/ƞ1.4. This diffusion control over the HTS folding is consistent wit...