Photocuring and Gelatin-Based Antibacterial Hydrogel for Skin Care

The development of moisturizing, antibacterial, and biocompatible multifunctional hydrogels is essential to protect skin and promote skin defects recovery. Gelatin has admired potential to be applied for skin care as a hydrogel in virtue of its hydrophilic biocompatible and biodegradable properties. In this study, triclosan-grafted gelatin and photo-cross-linkable methacrylated gelatin were synthesized and then combined to construct the semi-interpenetrating network and antibacterial hydrogels with the aid of a visible blue light. The antimicrobial test demonstrated that the resulting hydrogel obtained excellent inactivation capacity against E. coli, S. aureus, T. rubrum, and C. albicans with sterilizing rates of 99.998%, 99.998%, 99.19%, and 99.64%, respectively. In addition, the cytotoxicity, hemolysis, skin irritation, and rat skin wound healing experiments proved the good biocompatibility of the hydrogel. Therefore, this investigation sheds light on the development of multifunctional hydrogels in skin care.

Acute generalized exanthematous pustulosis complicated by cutaneous small vessel vasculitis: A case report and literature review

Acute generalized exanthematous pustulosis (AGEP) is a rare skin eruption characterized by widespread erythematous lesions covered with numerous pustules. Leukocytoclastic vasculitis is now considered an uncommon but possible histopathological feature within the clinical and pathological spectrum of AGEP. Our report describes a rare case of AGEP overlapping with cutaneous small vessel vasculitis, a condition that has only been reported once in the literature.

Oral treatment with 10% potassium iodide solution for refractory cutaneous-disseminated sporotrichosis in an immunocompetent adult: Case report

Sporotrichosis has multiple clinical manifestations, and its cutaneous-disseminated form is uncommon and, in most cases, related to immunosuppressive conditions. We report the case of a 47-year-old male patient who presented with multiple cutaneous nodules and ulcers on the left upper limb and the right thigh, with no other comorbidities. Until the diagnosis was confirmed, the patient was initially given empiric antifungal treatment with itraconazole, which showed unsatisfactory results at a local hospital. Then, he was treated with voriconazole, which led to the slow improvement of his skin lesions. At one point during the voriconazole treatment course, the patient briefly self-discontinued voriconazole for economic reasons, and the lesions recurred and worsened. The patient was finally diagnosed with cutaneous-disseminated sporotrichosis based on the isolation and identification of Sporothrix globosa. Susceptibility testing revealed that the isolate was resistant to itraconazole, fluconazole, voriconazole, terbinafine, and amphotericin. Considering the patient's poor financial condition, potassium iodide was administered. After 1-month of therapy with potassium iodide, he reported rapid improvement of his skin lesions. The patient continued potassium iodide treatment for another 5 months until the full resolution of lesions was achieved.

A recyclable and light-triggered nanofibrous membrane against the emerging fungal pathogen Candida auris

The emerging "super fungus" Candida auris has become an important threat to human health due to its pandrug resistance and high lethality. Therefore, the development of novel antimicrobial strategy is essential. Antimicrobial photodynamic therapy (aPDT) has excellent performance in clinical applications. However, the relevant study on antifungal activity and the mechanism involved against C. auris remains scarce. Herein, a recyclable and biodegradable polylactic acid-hypocrellin A (PLA-HA) nanofibrous membrane is newly developed. In vitro PLA-HA-aPDT could significantly reduce the survival rate of C. auris plankton and its biofilms, and the fungicidal effect of the membrane is still significant after four repeated uses. Simultaneously, PLA-HA exhibits good biocompatibility and low hemolysis. In vivo experiments show that PLA-HA-aPDT can promote C. auris-infected wound healing, reduce inflammatory response, and without obvious toxic side-effects. Further results reveal that PLA-HA-aPDT could increase endogenous reactive oxygen species (ROS) levels, leading to mitochondrial dysfunction, release of cytochrome C, activation of metacaspase, and nuclear fragmentation, thereby triggering apoptosis of C. auris. Compared with HA, PLA-HA shows stronger controllability and reusability, which can greatly improve the utilization efficiency of HA alone. Taken together, the efficacy, safety and antifungal activity make PLA-HA-aPDT a highly promising antifungal candidate for skin or mucous membrane C. auris infection.

It is urgent to develop new antifungal strategies to address the problem of Candida auris infection and drug resistance. Previous studies have revealed that antimicrobial photodynamic therapy (aPDT) based on natural products, such as hypocrellin A (HA), is a promising method in clinical applications. However, equivalent studies of aPDT on antifungal activity and its mechanism against C. auris remain scarce. Herein, we successfully prepared a recyclable, biodegradable, and light-driven antifungal PLA-HA nanofibrous membrane through the electrospinning technique. C. auris infection has been treated by aPDT in vitro and in vivo for the first time, especially HA-mediated aPDT. In vitro and in vivo experiments have provided sufficient lines of evidence that PLA-HA is a promising antifungal material for superficial C. auris infections due to its antifungal effect and excellent biocompatibility. Notably, there still remains a very high antifungal activity after utilizing PLA-HA four times. In addition, this study clarifies that the anti-C. auris mechanism of PLA-HA, namely, PLA-HA-mediated aPDT, is attributed to the formation of intracellular ROS, resulting in mitochondrial dysfunction and a decline in the mitochondrial transmembrane potential, releasing cytochrome C from mitochondria to the cytoplasm, promoting the activation of metacaspase, and inducing nuclear condensation and fragmentation of C. auris, thus triggering yeast cell apoptosis. This study lays a foundation for developing new antimicrobial nanofibrous dressings mediated by aPDT and provides an alternative strategy for the treatment of local fungal infectious diseases.

Skin Microbiota in Non-inflammatory and Inflammatory Lesions of Acne Vulgaris: The Underlying Changes within the Pilosebaceous Unit

Acne vulgaris is a common chronic inflammatory skin disease of the pilosebaceous unit. Clinical manifestations include seborrhea, non-inflammatory lesions, inflammatory lesions, or scar formation. Fourteen eligible participants of either sex, aged 18-28 years old, with mild to moderate acne lesions, were recruited in this observational study. The contents of 10 pilosebaceous units of non-inflammatory (comedones) and inflammatory lesions (papules and pustules) were collected from each participant's face and examined by amplicon metagenomics sequencing and real-time Polymerase Chain Reaction (PCR). Male participants, participants with a higher body mass index (BMI) than normal, and participants younger than 20 years old, were revealed to have a higher proportion of Malassezia in their non-inflammatory lesions than that in inflammatory lesions. There was an increased abundance of Malassezia restricta (M. restricta) and Cutibacterium acnes (C. acnes) in the non-inflammatory group. Correlation analysis indicated that Staphylococcus epidermidis (S. epidermidis) and M. restricta have similar proliferation trends with C. acnes during the transformation from non-inflammatory to inflammatory lesions. M. restricta probably involve in the microecological balance within the pilosebaceous unit.

Nocardia huaxiensis sp. nov., an actinomycete isolated from human skin

A novel actinomycete, designated as strain WCH-YHL-001^T, was isolated from skin biopsy specimens of a patient at West China Hospital, Chengdu, Sichuan Province, PR China. The cells were Gram-positive, aerobic, heterotrophic and non-motile. They formed an extensive substrate with short aerial mycelia, whose branches fragmented into rod-shaped elements. Growth occurred at 10-40 °C, pH 5.0-12.0 and with NaCl concentrations of 0-4.0 % (w/v). The major cellular fatty acids of strain WCH-YHL-001^T were C_16 : 0, C_18 : 1  ω9c, C_18 : 0 10-methyl and summed feature 3. The predominant respiratory quinone was MK-8 (H4ω-cycl). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, unknown phospholipids and unidentified glycolipids. The diagnostic diamino acid of peptidoglycan was meso-diaminopimelic acid. The whole-cell sugar pattern consisted of arabinose and glucose. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain WCH-YHL-001^T belonged to the genus Nocardia. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strain WCH-YHL-001^T and type strains of Nocardia species were lower than the cut-offs (≥95-96 % for ANI and ≥70 % for isDDH) required to define a bacterial species. The genomic DNA G+C content was 67.8 mol%. Phylogenetic, physiological and chemotaxonomic data suggested that strain WCH-YHL-001^T represented a novel species of the genus Nocardia, for which the name Nocardia huaxiensis sp. nov. is proposed, with the type strain WCH-YHL-001^T (=GDMCC 4.181^T=JCM 34475 ^T=NBRC 114973^T).

Itraconazole Induces Regression of Infantile Hemangioma via Downregulation of the Platelet-Derived Growth Factor-D/PI3K/Akt/mTOR Pathway

Infantile hemangioma is the most common benign vascular tumor of infancy. We have previously reported that itraconazole, a common antifungal agent, can clinically improve or cure infantile hemangioma; however, the underlying molecular mechanisms are still unclear. Here, we show that itraconazole treatment significantly inhibits proliferation and promotes apoptosis of the endothelial cells of mouse hemangioma cell line and infantile primary hemangioma endothelial cell. Itraconazole also remarkably reduced angiogenesis of hemangioma endothelial cell in vitro. We further performed transcriptome profiling via mRNA microarrays in hemangioma endothelial cell upon itraconazole treatment, and identified cytokine-cytokine receptor interaction as the top significantly enriched pathway. Importantly, itraconazole significantly reduced platelet-derived growth factor-D level, resulting in suppression of platelet-derived growth factor-β activation and inhibition of its downstream effectors, such as PI3K, Akt, 4E-BP1, and p70S6K, which are important for cellular growth and survival of infantile hemangioma. In conclusion, our results suggest that platelet-derived growth factor-D is a target of itraconazole in infantile hemangioma.

Oral treatment with valacyclovir for HSV-2-associated eczema herpeticum in a 9-month-old infant: A case report

BACKGROUND

Eczema herpeticum is a rare, severe, and disseminated infection of herpes simplex virus in the setting of eczematous skin diseases.

METHODS

We experienced a case of this disease in a 9-month-old infant characterized by a sudden onset of monomorphic vesicles on the head, right lower leg, and two hands. The infant has a 7-month history of atopic dermatitis and his condition was initially regarded as a complication of atopic dermatitis and bacterial infection. After treatment of cefoperazone and dexamethasone, the eruptions got worse. The diagnosis of eczema herpeticum was made according to the clinical features and further confirmed by the findings of herpes simplex virus type 2.

RESULTS

The infant was cured by oral treatment with valacyclovir.

CONCLUSION

The case highlights that the awareness for the sign of eczema herpeticum when diagnosing children with a sudden onset of disseminated vesicles in the setting of chronic skin disease should be increased. Oral valacyclovir may be an effective and convenient treatment option for pediatric outpatients with eczema herpeticum.

Atypical infantile genital Molluscum contagiosum

Genital molluscum contagiosum is rare in children. We report a molluscum contagiosum around the vulva and anus of 9-year-old girl, which has atypical presentations and was finally confirmed by histopathological and electron microscopy findings.

Successful treatment of oral itraconazole for infantile hemangiomas: a case series

Infantile hemangiomas can present a therapeutic challenge to clinicians, especially when associated with severe pain and feeding difficulties. The standard therapeutic management includes corticosteroids and propranolol. However, the clinical response is not always satisfactory. We present six cases of infantile hemangiomas successfully treated with oral itraconazole approximately 5 mg/kg per day. In the first month, the red color of the lesions became a little lighter and the growth of the lesions was controlled in all cases. An obvious clinical improvement was noted in all cases during the 3-month period, with 80-100% improvement in each patient at the end of the treatment, which was judged by both their parents and the dermatologists. Compliance with treatment instructions of oral itraconazole in infants was judged to be very good. Side-effects were mild and limited. Although itraconazole can inhibit angiogenesis and tumor growth in vitro and in vivo associated with some cancers, further research is required to understand the pathogenesis of infantile hemangiomas and the mechanism of itraconazole.

Scanning and transmission electron microscopic observation of the parasitic form of Trichophyton violaceum in the infected hair from tinea capitis

Trichophyton violaceum is a pathogen of tinea capitis and usually cause infection of scalp and hair in children. To investigate the parasitic form of T. violaceum in the human hair tissue, the infected hair strands were collected from a 9-year-old boy with tinea capitis due to T. violaceum and observed under both the scanning electron microscope (SEM) and transmission electron microscope (TEM). The SEM and TEM findings revealed that T. violaceum parasitically lives in the hair shaft in various forms and the morphological transformation of the fungus from hyphae into arthrospores was noted. The involved hair shaft was damaged to the great extent and its ultrastructural changes were evident. Those morphological characteristics of T. violaceum and the three-dimensional ultastructure changes of infected hairs give a better knowledge about the host-fungus relationship in tinea capitis.

The design of long-term effective uranium bioremediation strategy using a community metabolic model

Acetate amendment at uranium contaminated sites in Rifle, CO. leads to an initial bloom of Geobacter accompanied by the removal of U(VI) from the groundwater, followed by an increase of sulfate-reducing bacteria (SRBs) which are poor reducers of U(VI). One of the challenges associated with bioremediation is the decay in Geobacter abundance, which has been attributed to the depletion of bio-accessible Fe(III), motivating the investigation of simultaneous amendments of acetate and Fe(III) as an alternative bioremediation strategy. In order to understand the community metabolism of Geobacter and SRBs during artificial substrate amendment, we have created a genome-scale dynamic community model of Geobacter and SRBs using the previously described Dynamic Multi-species Metabolic Modeling framework. Optimization techniques are used to determine the optimal acetate and Fe(III) addition profile. Field-scale simulation of acetate addition accurately predicted the in situ data. The simulations suggest that batch amendment of Fe(III) along with continuous acetate addition is insufficient to promote long-term bioremediation, while continuous amendment of Fe(III) along with continuous acetate addition is sufficient to promote long-term bioremediation. By computationally minimizing the acetate and Fe(III) addition rates as well as the difference between the predicted and target uranium concentration, we showed that it is possible to maintain the uranium concentration below the environmental safety standard while minimizing the cost of chemical additions. These simulations show that simultaneous addition of acetate and Fe(III) has the potential to be an effective uranium bioremediation strategy. They also show that computational modeling of microbial community is an important tool to design effective strategies for practical applications in environmental biotechnology.

Negative regulation of the rat Na-K-ATPase alpha 3-subunit gene promoter by thyroid hormone

Na-K-ATPase alpha 3-subunit mRNA levels are both positively and negatively controlled by thyroid hormone [3,5,3'triiodothyronine (T3)] in primary cultures of neonatal rat cardiac myocytes. In this study, transient transfection analysis indicated that two regions of the rat alpha 3 gene between nucleotides -116 and -6 and -6 and +80 conferred T3-mediated inhibition of reporter gene expression. Electrophoretic mobility shift assays showed specific binding of T3 receptor monomers and T3 receptor-retinoid X receptor heterodimers at each alpha 3 gene negative T3-response region. The alpha 3 gene region from -116 to -6 base pairs also mediates repression in response to retinoic acid (RA) and binds RA receptor. In the absence of ligand, reporter gene expression driven by the -116 to -6-base pair region is repressed with cotransfection of T3 receptor, whereas it is unaffected by overexpression of RA receptor. These data demonstrate that the proximal promoter of the rat Na-K-ATPase alpha 3 gene contains sequence motifs that mediate repression of alpha 3 gene transcription in response to either T3 or RA in neonatal rat cardiac myocytes.