Widespread Necrotizing Purpura and Lucio Phenomenon as the First Diagnostic Presentation of Diffuse Nonnodular Lepromatous Leprosy.

Lucio phenomenon, or Lucio leprosy, is a rare severe lepra reaction that develops exclusively in patients with diffuse nonnodular lepromatous leprosy. It is characterized by irregular, angulated, or stellar necrotizing purpuric lesions that develop ulcerations. It mainly involves the extremities and develops as a result of massive invasion of vascular endothelial cells with lepra bacilli and secondary thrombotic vascular occlusion. Antiphospholipid antibodies often are detected in cases of Lucio phenomenon, and they are thought to play a role in its pathogenesis. We report a case of diffuse lepromatous leprosy in Egypt in which Lucio phenomenon with scrotal involvement and positive antiphospholipid antibodies was the first diagnostic presentation. The patient showed an excellent response to a combination of antileprotic treatment, low dose of prednisolone, acetylsalicylic acid, and anticoagulants. In addition, surgical debridement and vacuum therapy were performed for the scrotal lesion. Awareness of this grave presentation of leprosy is important for both dermatologists and rheumatologists to avoid misdiagnosis as vasculitis/collagen disease.

Shark tooth regeneration reveals common stem cell characters in both human rested lamina and ameloblastoma.

The human dentition is a typical diphyodont mammalian system with tooth replacement of most positions. However, after dental replacement and sequential molar development, the dental lamina undergoes apoptosis and fragments, leaving scattered epithelial units (dental lamina rests; DLRs). DLRs in adult humans are considered inactive epithelia, thought to possess limited capacity for further regeneration. However, we show that these tissues contain a small proportion of proliferating cells (assessed by both Ki67 and PCNA) but also express a number of common dental stem cell markers (Sox2, Bmi1, ß-catenin and PH3) similar to that observed in many vertebrates that actively, and continuously regenerate their dentition. We compared these human tissues with the dental lamina of sharks that regenerate their dentition throughout life, providing evidence that human tissues have the capacity for further and undocumented regeneration. We also assessed cases of human ameloblastoma to characterise further the proliferative signature of dental lamina rests. Ameloblastomas are assumed to derive from aberrant lamina rests that undergo changes, which are not well understood, to form a benign tumour. We suggest that dental lamina rests can offer a potential source of important dental stem cells for future dental regenerative therapy. The combined developmental genetic data from the shark dental lamina and ameloblastoma may lead to the development of novel methods to utilise these rested populations of adult lamina stem cells for controlled tooth replacement in humans.

Characterization of Aspergillus niger siderophore that mediates bioleaching of rare earth elements from phosphorites.

Siderophores are extra-cellular inducible compounds produced by aerobic microorganisms and plants to overcome iron insolubility via its chelation and then uptake inside the cell. This work aims to study the characteristics of siderophore that is produced by a rhizosphere-inhabiting fungus. This fungus has been morphologically and molecularly identified as Aspergillus niger with the ability to produce 87% siderophore units. The obtained siderophore in PDB medium gave a positive result with tetrazolium test and a characteristic spectrum with a maximum absorbance at 450 nm in FeCl3 test that did not shift in response to different pH degrees (5-9). This indicates that the obtained siderophore is a trihydroxymate in nature. After purification, the FTIR and NMR analyses showed that the obtained siderophore is considered to be ferrichrome. The purified siderophore has been further evaluated as a tool to extract uranium, thorium and rare earth elements (REEs) from Egyptian phosphorites obtained from Abu Tartur Mine area. The inductively coupled plasma atomic emission spectroscopy analysis showed that the highest removal efficiency percentage was for uranium (69.5%), followed by samarium (66.7%), thorium (55%), lanthanum (51%), and cerium (50.1%). This result confirmed the ability of hydroxymate siderophores to chelate the aforementioned precious elements, a result that paves the way for bioleaching to replace abiotic techniques in order to save the cost of such elements in an environmentally friendly way.