Subcutaneous fat necrosis of the newborn: A systematic review of surgical management and outcomes.

BACKGROUND: Subcutaneous fat necrosis of the newborn (SCFN) is a rare form of panniculitis manifesting as erythematous plaques or nodules at sites of brown fat in neonates. Surgical management may be indicated in severe cases; however, there is a paucity of literature compiling presentations and outcomes of these surgical patients. METHODS: The authors performed a systematic review, in consultation with a licensed librarian, on MEDLINE and Embase for studies including patients with SCFN who were surgically managed. RESULTS: The search strategy generated 705 results, among which 213 (30.2%) were excluded for lack of discussion on surgical management. Twenty-two studies discussed surgical management of SCFN in 26 patients, but in 6 of these studies the patients were not surgically managed. Ultimately, 16 articles with 16 patients who were surgically managed were included in the study. Average age at diagnosis was 11.8 ± 9.8 days; average age at surgery was 39.5 ± 70.4 days. The most common etiologies were "unknown" (6, 37.5%), therapeutic hypothermia (4, 25.0%), and birth complications (4, 25.0%). Patients harbored nodules on the back (14, 87.5%), upper extremities (7, 43.8%), lower extremities (7, 43.8%), buttocks (5, 31.3%), and head or neck (3, 18.8%). Linear regression models revealed the presence of back lesions and predicted concomitant medical complications (ß = 2.71, p = 0.021). CONCLUSIONS: Patients undergoing surgical management for SCFN most commonly harbor lesions on the back and extremities that are secondary to therapeutic hypothermia or of unknown origin. Reporting of additional cases is needed to further elucidate surgical management and outcomes.

Foramen lacerum impingement of trigeminal nerve root as a rodent model for trigeminal neuralgia.

Trigeminal neuralgia (TN) is a classic neuralgic pain condition with distinct clinical characteristics. Modeling TN in rodents is challenging. Recently, we found that a foramen in the rodent skull base, the foramen lacerum, provides direct access to the trigeminal nerve root. Using this access, we developed a foramen lacerum impingement of trigeminal nerve root (FLIT) model and observed distinct pain-like behaviors in rodents, including paroxysmal asymmetric facial grimaces, head tilt when eating, avoidance of solid chow, and lack of wood chewing. The FLIT model recapitulated key clinical features of TN, including lancinating pain-like behavior and dental pain-like behavior. Importantly, when compared with a trigeminal neuropathic pain model (infraorbital nerve chronic constriction injury [IoN-CCI]), the FLIT model was associated with significantly higher numbers of c-Fos-positive cells in the primary somatosensory cortex (S1), unraveling robust cortical activation in the FLIT model. On intravital 2-photon calcium imaging, synchronized S1 neural dynamics were present in the FLIT but not the IoN-CCI model, revealing differential implication of cortical activation in different pain models. Taken together, our results indicate that FLIT is a clinically relevant rodent model of TN that could facilitate pain research and therapeutics development.

Hydropersulfides (RSSH) Outperform Post-Conditioning and Other Reactive Sulfur Species in Limiting Ischemia-Reperfusion Injury in the Isolated Mouse Heart.

Hydrogen sulfide (H2S) exhibits protective effects in cardiovascular disease such as myocardial ischemia/reperfusion (I/R) injury, cardiac hypertrophy, and atherosclerosis. Despite these findings, its mechanism of action remains elusive. Recent studies suggest that H2S can modulate protein activity through redox-based post-translational modifications of protein cysteine residues forming hydropersulfides (RSSH). Furthermore, emerging evidence indicates that reactive sulfur species, including RSSH and polysulfides, exhibit cardioprotective action. However, it is not clear yet whether there are any pharmacological differences in the use of H2S vs. RSSH and/or polysulfides. This study aims to examine the differing cardioprotective effects of distinct reactive sulfur species (RSS) such as H2S, RSSH, and dialkyl trisulfides (RSSSR) compared with canonical ischemic post-conditioning in the context of a Langendorff ex-vivo myocardial I/R injury model. For the first time, a side-by-side study has revealed that exogenous RSSH donation is a superior approach to maintain post-ischemic function and limit infarct size when compared with other RSS and mechanical post-conditioning. Our results also suggest that RSSH preserves mitochondrial respiration in H9c2 cardiomyocytes exposed to hypoxia-reoxygenation via inhibition of oxidative phosphorylation while preserving cell viability.

Development of Hydropersulfide Donors to Study Their Chemical Biology.

Significance: Hydropersulfides (RSSH) are ubiquitous in prokaryotes, eukaryotic cells, and mammalian tissues. The unique chemical properties and prevalent nature of these species suggest a crucial role of RSSH in cell regulatory processes, yet little is known about their physiological functions. Recent Advances: Examining the biological roles of RSSH species is challenging because of their inherent instability. In recent years, researchers have developed a number of small-molecule donors that efficiently release RSSH in response to various stimuli, including pH, thiols, reactive oxygen species, enzymes, and light. These RSSH donors have provided researchers with chemical tools to uncover the potential function and role of RSSH as physiological signaling and/or protecting agents. Critical Issues: Because RSSH, hydrogen sulfide (H2S), and higher order polysulfides are related to each other and can be present simultaneously in biological systems, distinguishing among the activities due to each of these species is difficult. Discerning this activity is critical to elucidate the chemical biology and physiology of RSSH. Moreover, although RSSH donors have been shown to confer cytoprotection against oxidative and electrophilic stress, their biological targets remain to be elucidated. Future Directions: The development of RSSH donors with optimal drug-like properties and selectivity toward specific tissues/pathologies represents a promising approach. Further investigation of releasing efficiencies in vivo and a clear understanding of RSSH biological responses remain targets for future investigation. Antioxid. Redox Signal. 36, 309-326.