Prevention and treatment of microstomia.

The mouth, located in the lower third of the face, is a uniquely visible structure. It serves as a vital organ both aesthetically and functionally, playing a key role in speech, expression, and fundamental oral functions. Consequently, any alterations or defects in its shape, due to various causes, can lead to aesthetic and functional deficiencies. These issues may also result in challenges with social interactions and a decrease in confidence. In cases of microstomia, various surgical approaches are proposed based on the location, extent, shape, and cause of the defect, leading to numerous case reports. Plastic surgeons are proficient in oral reconstruction; however, cases of microstomia are relatively rare, which reduces their familiarity and interest in these cases. Additionally, preferences for oral size and shape vary according to factors such as geographical region and ethnicity, further complicating the functional definition of microstomia. Therefore, both subjective patient and physician judgments play crucial roles in the diagnosis and treatment of microstomia, as these may vary depending on individual and societal aspects. This review aims to classify the various causes and definitions of microstomia, as well as its non-surgical and surgical treatment options, with the goal of the treatment of this condition.

Reconstruction of Squamous Cell Carcinoma on Oral Commissure With Hatchet-Shaped Flap.

The mouth is a unique and prominent element of the lower face. Given the complex anatomy, aesthetic appearance, and function of the oral commissure, its reconstruction due to various causes presents a significant challenge for surgeons. Squamous cell carcinoma (SCC) of the lip is the most common type of oral cancer, accounting for approximately 25% to 30% of all oral cancers. Wide excision is the treatment of choice, and the prognosis is generally favorable. We encountered a case of SCC of the right oral commissure in a 69-year-old man. We designed a hatchet-shaped flap to minimize anatomical disruption and, as a result, achieved satisfactory outcomes in terms of both functionality and aesthetics.

Cellular senescence is associated with the spatial evolution toward a higher metastatic phenotype in colorectal cancer.

In this study, we explore the dynamic process of colorectal cancer progression, emphasizing the evolution toward a more metastatic phenotype. The term "evolution" as used in this study specifically denotes the phenotypic transition toward a higher metastatic potency from well-formed glandular structures to collective invasion, ultimately resulting in the development of cancer cell buddings at the invasive front. Our findings highlight the spatial correlation of this evolution with tumor cell senescence, revealing distinct types of senescent tumor cells (types I and II) that play different roles in the overall cancer progression. Type I senescent tumor cells (p16INK4A+/CXCL12+/LAMC2-/MMP7-) are identified in the collective invasion region, whereas type II senescent tumor cells (p16INK4A+/CXCL12+/LAMC2+/MMP7+), representing the final evolved form, are prominently located in the partial-EMT region. Importantly, type II senescent tumor cells associate with local invasion and lymph node metastasis in colorectal cancer, potentially affecting patient prognosis.

CDK4/6 inhibitors induce breast cancer senescence with enhanced anti-tumor immunogenic properties compared with DNA-damaging agents.

Since therapy-induced senescence (TIS) can either support or inhibit cancer progression, identifying which types of chemotherapeutic agents can produce the strongest anti-tumor TIS is an important issue. Here, cyclin-dependent kinase4/6 inhibitors (CDK4/6i)-induced senescence was compared to the TIS induced by conventional DNA-damaging agents. Despite both types of agents eliciting a similar degree of senescence, we observed increased expression of the senescence-associated secretory phenotype (SASP) and ligands related to pro-tumor immunity (IL6, CXCL8, TGFß, CD274, and CEACAM1) and angiogenesis (VEGFA) mainly in TIS induced by DNA-damaging agents rather than by CDK4/6i. Additionally, although all agents increased the expression of anti-tumor immunomodulatory proteins related to antigen presentation (MHC-I, B2M) and T cell chemokines (CXCL9, 10, 11), CDK4/6i-induced senescent cells still maintained this expression at a similar or even higher intensity than cells treated with DNA-damaging agents, despite the absence of nuclear factor-kappa-B (NF-κB) and p53 activation. These data suggest that in contrast with DNA-damaging agents, which augment the pro-tumorigenic microenvironment via pro-inflammatory SASP, CDK4/6i can generate TIS only with antitumor immunomodulatory proteins.

Senescent tumor cells in colorectal cancer are characterized by elevated enzymatic activity of complexes 1 and 2 in oxidative phosphorylation.

BACKGROUND: Cellular senescence is defined as an irreversible cell cycle arrest caused by various internal and external insults. While the metabolic dysfunction of senescent cells in normal tissue is relatively well-established, there is a lack of information regarding the metabolic features of senescent tumor cells. METHODS: Publicly available single-cell RNA-sequencing data from the GSE166555 and GSE178341 datasets were utilized to investigate the metabolic features of senescent tumor cells. To validate the single-cell RNA-sequencing data, we performed senescence-associated ß-galactosidase (SA-ß-Gal) staining to identify senescent tumor cells in fresh frozen colorectal cancer tissue. We also evaluated nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase (NADH-TR) and succinate dehydrogenase (SDH) activity using enzyme histochemical methods and compared the staining with SA-ß-Gal staining. MTT assay was performed to reveal the complex 1 activity of the respiratory chain in in-vitro senescence model. RESULTS: Single-cell RNA-sequencing data revealed an upregulation in the activity of complexes 1 and 2 in oxidative phosphorylation, despite overall mitochondrial dysfunction in senescent tumor cells. Both SA-ß-Gal and enzyme histochemical staining using fresh frozen colorectal cancer tissues indicated a high correlation between SA-ß-Gal positivity and NADH-TR/SDH staining positivity. MTT assay showed that senescent colorectal cancer cells exhibit higher absorbance in 600 nm wavelength. CONCLUSIONS: Senescent tumor cells exhibit distinct metabolic features, characterized by upregulation of complexes 1 and 2 in the oxidative phosphorylation pathway. NADH-TR and SDH staining represent efficient methods for detecting senescent tumor cells in colorectal cancer.

Mid-old cells are a potential target for anti-aging interventions in the elderly.

The biological process of aging is thought to result in part from accumulation of senescent cells in organs. However, the present study identified a subset of fibroblasts and smooth muscle cells which are the major constituents of organ stroma neither proliferative nor senescent in tissues of the elderly, which we termed "mid-old status" cells. Upregulation of pro-inflammatory genes (IL1B and SAA1) and downregulation of anti-inflammatory genes (SLIT2 and CXCL12) were detected in mid-old cells. In the stroma, SAA1 promotes development of the inflammatory microenvironment via upregulation of MMP9, which decreases the stability of epithelial cells present on the basement membrane, decreasing epithelial cell function. Remarkably, the microenvironmental change and the functional decline of mid-old cells could be reversed by a young cell-originated protein, SLIT2. Our data identify functional reversion of mid-old cells as a potential method to prevent or ameliorate aspects of aging-related tissue dysfunction.

Anhydrous Alum Inhibits α-MSH-Induced Melanogenesis by Down-Regulating MITF via Dual Modulation of CREB and ERK.

Melanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use.

Surgical outcomes of suprafascial and subfascial radial forearm free flaps in head and neck reconstruction.

BACKGROUND: Conventional radial forearm free flaps (RFFFs) are known to be safe, but can result in donor site complications. Based on our experiences with suprafascial and subfascial RFFFs, we evaluated the safety of flap survival and surgical outcomes. METHODS: This was a retrospective study of head and neck reconstructions using RFFFs from 2006 to 2021. Thirty-two patients underwent procedures using either subfascial (group A) or suprafascial (group B) dissection for flap elevation. Data were collected on patient characteristics, flap size, and donor and recipient complications, and the two groups were compared. RESULTS: Thirteen of the 32 patients were in group A and 19 were in group B. Group A included 10 men and three women, with a mean age of 56.15 years, and group B included 16 men and three women, with a mean age of 59.11 years. The mean defect areas were 42.83 cm² and 33.32 cm², and the mean flap sizes were 50.96 cm² and 44.54 cm² in groups A and B, respectively. There were 13 donor site complications: eight (61.5%) in group A and five (26.3%) in group B. Flexor tendon exposure occurred in three patients in group A and in none in group B. All flaps survived completely. A recipient site complication occurred in two patients (15.4%) in group A and three patients (15.8%) in group B. CONCLUSIONS: Complications and flap survival were similar between the two groups. However, tendon exposure at the donor site was less prevalent in the suprafascial group, and the treatment period was shorter. Based on our data, suprafascial RFFF is a reliable and safe procedure for reconstruction of the head and neck.

Teaching Models for Correct Rhombic Flaps.

The aim of this study was to introduce teaching models for correct rhombic flaps. For the line of maximal extensibility (LME) and flap design, surgical fabric (model 1), scored corrugated cardboard (model 2), and scored polyethylene sheet (model 3) were used. For choosing the correct flaps, a silicone face (model 4) was used. Seven participants in the Plastic Surgery Department were recruited for the workshop. In models 1 to 3, a 2-cm diameter circle and relaxed skin tension line were indicated. Participants were requested to design Limberg flaps. Each flap was elevated, transposed, and fixed with sutures (model 1) or cellophane tape (models 2 and 3). In model 4, a 1-cm diameter circle was indicated on the cheek. Participants were requested to design correct Limberg flaps. Although participants were not provided an article describing how to create correct Limberg flaps, they eventually created correct flaps through trial and error. Participants drew 2 parallel lines tangential to the defect and following the LME, perpendicular to the relaxed skin tension lines, which are the same as the scoring marks. They then drew 2 other sides of 2 possible parallelograms by tilting them medially and laterally with angles of 60 and 120 degrees each. Thus, 4 possible Limberg flaps to close the defect were drawn. Among the 8 possible flaps, 4 flaps that did not follow the LME were eliminated. Scored polyethylene sheet had the best extensibility and least distortion among the 3 models. Through this workshop, participants learned to design rhombic flaps correctly, using 2 parallel LMEs.

Reconstruction of Rapidly Growing Merkel Cell Carcinoma of the Cheek With Multidisciplinary Cooperation.

Merkel cell carcinoma (MCC) is a rare and very aggressive skin cancer. An 83-year-old female presented with a 1.5 cm-sized non-tender mass on her left cheek and was diagnosed with MCC. The margin of MCC was well-defined and there was no cervical node metastasis on pre-operative computed tomography. Three weeks after the first visit, the mass rapidly increased in size. We checked the magnetic resonance imaging, a rapid-growing 2.5 cm sized nodular region and metastatic cervical lymph node were found. We performed wide excision of the MCC and neck lymph need dissection with multidisciplinary cooperation. The soft tissue defect was about 6.0×5.0 cm 2 in size and reconstructed with radial forearm free flap. On permanent biopsy, the size of MCC was 3.0×2.3 cm 2 . There was no recurrence of MCC with radiation therapy during an 18-month follow-up. We experienced an older patient with a rapid - growing MCC and cervical lymph node metastasis in a brief time. With our experience, we discuss the evaluation and treatment plan of the rapid-growing MCC for good results.

ANT2 Accelerates Cutaneous Wound Healing in Aged Skin by Regulating Energy Homeostasis and Inflammation.

An effective healing response is critical to healthy aging. In particular, energy homeostasis has become increasingly recognized as a factor in effective skin regeneration. ANT2 is a mediator of adenosine triphosphate import into mitochondria for energy homeostasis. Although energy homeostasis and mitochondrial integrity are critical for wound healing, the role played by ANT2 in the repair process had not been elucidated to date. In our study, we found that ANT2 expression decreased in aged skin and cellular senescence. Interestingly, overexpression of ANT2 in aged mouse skin accelerated the healing of full-thickness cutaneous wounds. In addition, upregulation of ANT2 in replicative senescent human diploid dermal fibroblasts induced their proliferation and migration, which are critical processes in wound healing. Regarding energy homeostasis, ANT2 overexpression increased the adenosine triphosphate production rate by activating glycolysis and induced mitophagy. Notably, ANT2-mediated upregulation of HSPA6 in aged human diploid dermal fibroblasts downregulated proinflammatory genes that mediate cellular senescence and mitochondrial damage. This study shows a previously uncharacterized physiological role of ANT2 in skin wound healing by regulating cell proliferation, energy homeostasis, and inflammation. Thus, our study links energy metabolism to skin homeostasis and reports, to the best of our knowledge, a previously unreported genetic factor that enhances wound healing in an aging model.

Unusual anomaly of the radial artery encountered during the elevation of a radial forearm free flap: a case report.

The radial forearm free flap (RFFF) has become popular for head and neck reconstructions. Owing to a constant anatomy the RFFF is relatively easy to dissect. Nevertheless, anatomical variations of the radial artery have been reported. Some variations could affect the survival of the flap. This paper reports an unusual anomaly of the radial artery where the radial artery was not located between the brachioradialis (BR) and flexor carpi radialis. The radial artery was observed above the BR and on the radial side of the BR. The survival of the elevated flap was deemed questionable because it had only few perforators. So we decided to discard the flap and to elevate another free flap for the head and neck defect. The donor area on the forearm was covered using the original skin of the first flap as a full-thickness skin graft. This case highlights a means to deal with anomalies of the radial artery encountered during the elevation of RFFF and the checking process for variations of the radial artery before RFFF.

p15INK4B is an alternative marker of senescent tumor cells in colorectal cancer.

Senescent tumor cells are nonproliferating tumor cells which are closely related to cancer progression by secreting senescence-related molecules, called senescence-associated secreting phenotypes. Therefore, the presence of senescent tumor cells is considered a prognostic factor in various cancer types. Although senescence-associated ß-galactosidase staining is considered the best marker for detection of senescent tumor cells, it can only be performed in fresh-frozen tissues. p16INK4A, a cyclin-dependent inhibitor, has been used as an alternative marker to detect senescent tumor cells in formalin-fixed paraffin-embedded tissues. However, other reliable markers to detect senescent tumor cells is still lacking. In the present study, using public single-cell RNA-sequencing data, we found that p15INK4B, a cyclin-dependent kinase inhibitor, is a novel marker for detection of senescent tumor cells. Moreover, p15INK4B expression was positively correlated with that of p16INK4A in colorectal cancer tissues. In in vitro studies, mRNA expression of p15INK4B was increased together with that of p16INK4A in H2O2- and therapy-induced cancer senescence models. However, the mRNA level of p15INK4B did not increase in the oncogene-induced senescence model in primary colonic epithelial cells. In conclusion, p15INK4B is a potential alternative marker for detection of senescent tumor cells together with conventional markers in advanced stages of colorectal cancer.

A Case of Malignant Transformation of Solitary Recurrent Cylindroma on Scalp.

A 78-year-old male presented with an asymptomatic pinkish multi-nodular mass on his frontal scalp. The lesion had recurred twice after incomplete surgical excision. Initial punch biopsy was diagnosed with cylindroma. He revisited after one year with exophytic enlargement of the mass, and two staged Mohs micrographic surgery identified well-differentiated malignant cylindroma. Histopathology in the lower dermis and periosteal layer showed atypical cells with mitosis and hyperchromatic nucleoli with increased Ki-67 index of 10% to 30%. The postoperative wound was successfully treated with negative wound pressure therapy (NPWT) and secondary intentional healing. We report this case showing malignant transformation of solitary cylindroma, and good result for secondary intention healing using NPWT for postoperative defect.

Developmental endothelial locus-1 attenuates palmitate-induced apoptosis in tenocytes through the AMPK/autophagy-mediated suppression of inflammation and endoplasmic reticulum stress.

AIMS: Myokine developmental endothelial locus-1 (DEL-1) has been documented to alleviate inflammation and endoplasmic reticulum (ER) stress in various cell types. However, the effects of DEL-1 on inflammation, ER stress, and apoptosis in tenocytes remain unclear. METHODS: Human primary tenocytes were cultured in palmitate (400 µM) and palmitate plus DEL-1 (0 to 2 µg/ml) conditions for 24 hours. The expression levels of ER stress markers and cleaved caspase 3, as well as phosphorylated 5' adenosine monophosphate-activated protein kinase (AMPK) and autophagy markers, were assessed by Western blotting. Autophagosome formation was measured by staining with monodansylcadaverine, and apoptosis was determined by cell viability assay and caspase 3 activity assay. RESULTS: We found that treatment with DEL-1 suppressed palmitate-induced inflammation, ER stress, and apoptosis in human primary tenocytes. DEL-1 treatment augmented LC3 conversion and p62 degradation as well as AMPK phosphorylation. Moreover, small interfering RNA for AMPK or 3-methyladenine (3-MA), an autophagy inhibitor, abolished the suppressive effects of DEL-1 on inflammation, ER stress, and apoptosis in tenocytes. Similar to DEL-1, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMPK, also attenuated palmitate-induced inflammation, ER stress, and apoptosis in tenocytes, which 3-MA reversed. CONCLUSION: These results revealed that DEL-1 suppresses inflammation and ER stress, thereby attenuating tenocyte apoptosis through AMPK/autophagy-mediated signalling. Thus, regular exercise or administration of DEL-1 may directly contribute to improving tendinitis exacerbated by obesity and insulin resistance.Cite this article: Bone Joint Res 2022;11(12):854-861.

Reconstruction of Multiple Digital Defects by Temporary Syndactylization Using a Lateral Arm Free Flap.

Background Soft tissue defects of the multiple finger present challenges to reconstruction surgeons. Here, we introduce the use of a lateral arm free flap and syndactylization for the coverage of multiple finger soft tissue defects. Methods This retrospective study was conducted based on reviews of the medical records of 13 patients with multiple soft tissue defects of fingers ( n = 33) that underwent temporary syndactylization with a microvascular lateral arm flap for temporary syndactylization from January 2010 to December 2020. Surgical and functional outcomes, times of flap division, complications, and demographic data were analyzed. Results Middle fingers were most frequently affected, followed by ring and index fingers. Mean patient age was 43.58 years. The 13 patients had suffered 10 traumas, 2 thermal burns, and 1 scar contracture. Release of temporary syndactyly was performed 3 to 9 weeks after syndactylization. All flaps survived, but partial necrosis occurred in one patient, who required a local transposition flap after syndactylization release. The mean follow-up was 15.8 months. Conclusion Coverage of multiple finger defects by temporary syndactylization using a free lateral arm flap with subsequent division offers an alternative treatment option.

Transcriptional Heterogeneity of Cellular Senescence in Cancer.

Cellular senescence plays a paradoxical role in tumorigenesis through the expression of diverse senescence-associated (SA) secretory phenotypes (SASPs). The heterogeneity of SA gene expression in cancer cells not only promotes cancer stemness but also protects these cells from chemotherapy. Despite the potential correlation between cancer and SA biomarkers, many transcriptional changes across distinct cell populations remain largely unknown. During the past decade, single-cell RNA sequencing (scRNA-seq) technologies have emerged as powerful experimental and analytical tools to dissect such diverse senescence-derived transcriptional changes. Here, we review the recent sequencing efforts that successfully characterized scRNA-seq data obtained from diverse cancer cells and elucidated the role of senescent cells in tumor malignancy. We further highlight the functional implications of SA genes expressed specifically in cancer and stromal cell populations in the tumor microenvironment. Translational research leveraging scRNA-seq profiling of SA genes will facilitate the identification of novel expression patterns underlying cancer susceptibility, providing new therapeutic opportunities in the era of precision medicine.

Ponatinib-induced eruptive nevi and melanocytic proliferation.

Ponatinib, an oral third-generation tyrosine kinase inhibitor, is indicated for the treatment of imatinib-resistant leukemia. We experienced a case of ponatinib-induced eruptive nevi, and the biologic effects of ponatinib on melanocytes were investigated. Treatment with ponatinib significantly increased the proliferation of normal human melanocyte or melanoma cells through the upregulation of the extracellular signal-regulated kinase and protein kinase B signaling pathways. The downstream molecules of cyclin B1 and D1 were significantly increased in ponatinib-treated melanocytes. These results demonstrate the capacity of ponatinib to induce the proliferation and tumorigenesis of melanocytes.

Source tracking of dissolved organic nitrogen at the molecular level during storm events in an agricultural watershed.

Accelerated export of nitrogen-containing dissolved organic matter (DOM) or dissolved organic nitrogen (DON) to streams and rivers from agricultural watersheds has been reported worldwide. However, few studies have examined the dynamics of DOM molecular composition with the attention paid to the relative contributions of DON from various sources altered with flow conditions. In this study, end-member mixing analysis (EMMA) was conducted with the optical properties of DOM to quantify the relative contributions of several major organic matter sources (litter, reed, field soil, and manure) in two rivers of a small agricultural watershed. DOC and DON concentration increased during the storm events with an input of allochthonous DOM as indicated by an increase in specific ultraviolet absorbance at 254 nm (SUVA254) and a decrease in biological index (BIX), fluorescence index (FI), and protein-like component (%C3) at high discharge. EMMA results based on a Bayesian mixing model using stable isotope analysis in R (SIAR) were more accurate in source tracking than those using the traditional IsoSource program. Manure (>30%) and field soil (also termed as "manure-impacted field soil") (>23%) end-members revealed their predominant contributions to the riverine DOM in SIAR model, which was enhanced during the storm event (up to 56% and 38%, respectively). The molecular composition of the riverine DOM exhibited a distinct footprint from the manure and manure-impacted field soil, with a larger number of CHON formulas and abundant polyphenols and condensed aromatics in peak flow samples in the studied rivers. The riverine DOM during peak flow contained many unique molecular formulas in both rivers (4980 and 2082) of which >60% originated from manure and manure-impacted field soil. Combining the EMMA with DOM molecular composition clearly demonstrated the effect of manure fertilizer on the riverine DOM of the watershed with intensive agriculture. This study provides insights into the source tracking and regulation of DON leaching from anthropogenically altered river systems worldwide.

Senescent tumor cells: an overlooked adversary in the battle against cancer.

Senescent cells in cancer tissue, including senescent fibroblasts and macrophages, have been reported to increase the malignant potency of cancer cells by secreting senescence-associated secretory phenotype (SASP). Otherwise, Senescence of tumor cells has been believed to inhibit tumor growth by halting the massive proliferation and increasing the chances of immune clearance. In particular, senescent tumor cells (STCs) have been thought that they rarely exist in carcinomas because oncogene-induced senescence needs to be overcome for protumorigenic cells to become malignant. However, recent studies have revealed that a considerable number of STCs are present in cancer tissue, even in metastatic sites. In fact, STCs are widely involved in cancer progression by leading to collective invasion and building a cytokine barrier to protect nonsenescent tumor cells from immune attack. Furthermore, therapy-induced STCs can induce tumor progression and recurrence by increasing stemness. However, obscure causative factors and their heterogeneity in various cancers make it difficult to establish the physiological role of STCs. Here, we summarize and review the current knowledge of the pathophysiology and role of STCs. We also outline the current status of therapeutic strategies for directly removing STCs or modulating the SASPs to maximize the positive functions of STCs while suppressing the negative functions.