Ankylosing spondylitis associated with Sweet’s syndrome: a case report

<p>Abstract</p> <p>Introduction</p> <p>Sweet’s syndrome is an acute neutrophilic dermatosis characterized by a diffuse dermal infiltrate of mature neutrophils. In most cases, it occurs as an isolated phenomenon (idiopathic Sweet’s syndrome) but it can be drug induced or associated with a variety of underlying diseases such as infections, neoplasms, and chronic inflammatory diseases. The association between Sweet’s syndrome and ankylosing spondylitis is rare. Only a few cases have been reported in the literature. We report a new case in which we describe an outbreak of acute neutrophilic dermatosis revealing ankylosing spondylitis.</p> <p>Case presentation</p> <p>A 33-year-old Moroccan man presented with large-joint polyarthralgia, inflammatory pain in his buttocks and lower lumbar spine, fever and skin lesions. On examination, the patient had a low-grade fever, six tender but not swollen joints, limitation of motion of the lumbar spine, and painful erythematous maculopapules over his face, neck, and hands. Laboratory tests showed hyperleukocytosis, and elevated erythrocyte sedimentation rate and C-reactive protein. The immunological tests and infectious disease markers were negative. Investigations for an underlying neoplastic disease remained negative. Magnetic resonance imaging showed a bilateral sacroiliitis. Skin biopsy findings were consistent with Sweet’s syndrome. The diagnosis of Sweet’s syndrome associated with ankylosing spondylitis was established. Nonsteroid anti-inflammatory drugs were started and the patient showed rapid clinical and biological improvement.</p> <p>Conclusion</p> <p>Three observations of the association between Sweet’s syndrome and spondylarthropathy have been reported in the literature. The cause of this association remains unclear. Some hypotheses have been developed, but further studies are needed to confirm or refute them.</p

Capturing the formation of sub-nanometer sized CdS clusters in LTL zeolite

The radiolytic preparation of sub-nanometer sized CdS clusters in LTL-type zeolite crystals in suspension is reported. The growing process of CdS in the zeolite crystals using a γ-ray irradiator (low dose rate) and a pulse electron accelerator (high dose rate) is followed by UV-vis spectroscopy. The pulse electron accelerator equipped with a transient absorption setup allowed the real-time capturing of CdS formed in the zeolite suspension. Two distinct stages during the formation of sub-nanometer sized CdS clusters in the LTL-type zeolite are identified: (i) fast formation of dispersed small oligomers exhibiting a well-defined sharp absorption peak, which is shifted from 292 to 350 nm in the course of the growth process, and (ii) formation of interconnected CdS clusters along the zeolite channels by diffusion-assisted process. Additionally, the presence of sub-nanometer sized CdS clusters in the zeolite channels is confirmed by transmission electron microscopy (TEM). The sub-nanometer sized CdS clusters formed in the LTL-type zeolite suspension exhibit good stability under hydrous conditions, and no coalesce in the presence of water is observed