Regulatory and pathogenic mechanisms in response to iron deficiency and excess in fungi.

Iron is an essential element for all eukaryote organisms because of its redox properties, which are important for many biological processes such as DNA synthesis, mitochondrial respiration, oxygen transport, lipid, and carbon metabolism. For this reason, living organisms have developed different strategies and mechanisms to optimally regulate iron acquisition, transport, storage, and uptake in different environmental responses. Moreover, iron plays an essential role during microbial infections. Saccharomyces cerevisiae has been of key importance for decrypting iron homeostasis and regulation mechanisms in eukaryotes. Specifically, the transcription factors Aft1/Aft2 and Yap5 regulate the expression of genes to control iron metabolism in response to its deficiency or excess, adapting to the cell's iron requirements and its availability in the environment. We also review which iron-related virulence factors have the most common fungal human pathogens (Aspergillus fumigatus, Cryptococcus neoformans, and Candida albicans). These factors are essential for adaptation in different host niches during pathogenesis, including different fungal-specific iron-uptake mechanisms. While being necessary for virulence, they provide hope for developing novel antifungal treatments, which are currently scarce and usually toxic for patients. In this review, we provide a compilation of the current knowledge about the metabolic response to iron deficiency and excess in fungi.

Extreme dermatology--the intensive care skills of dermatologists in three case presentations of acute skin failure.

Dermatological emergencies include a number of clinical conditions usually accompanied by systemic symptoms that can lead to life-threatening complications. From the broad spectrum of life-threatening dermatoses, three cases are presented: a case of febrile ulceronecrotic Mucha-Habermann disease (FUMHD), a case of pemphigus vulgaris mimicking Stevens-Johnson syndrome (SJS), and a case of toxic epidermal necrolysis (TEN). Those cases were considered extreme, and presented to illustrate the positive outcome of timely intensive dermatological care. An interdisciplinary approach is essential in the diagnosis, treatment, management, and follow up of patients with life-threatening dermatoses.

Matrix metalloproteinase 9 levels in gingival crevicular fluid in patients after periodontal microsurgery for orthodontic induced gingival hypertrophy.

INTRODUCTION: In this study, we aim to compare the levels of matrix metalloproteinase 9 (MMP9) in the gingival crevicular fluid (GCF), as indicators for healing, in two groups of patients - operated with a classic periodontal surgical technique and the same technique but using a dental microscope. MATERIALS: We included 14 patients with ages between 12 and 26 years, average 14±6.2 years. Eight patients were women and six men. All patients presented gingival hypertrophy because of the orthodontic treatment on the mandibular arch. We performed gingivectomy on one-half of the mandibular arch by classic periodontal surgery and on the other half of the mandibular arch by a microscope-assisted gingivectomy. METHODS: In the hypertrophied gingiva, the expression of MMP9 was identified using immunohistochemical-staining techniques. For immunological determination of MMP9 in GCF we performed Elisa tests. RESULTS: We found different levels in different moments of the healing process for the two hemiarcades. CONCLUSIONS: We consider that faster healing in case of microscope-assisted gingivectomy may be related to the expression of MMP-9 in the GCF.