Severe hemorrhagic bullous lesions in Henoch Schonlein purpura: three pediatric cases and review of the literature

Henoch Schonlein purpura (HSP) is a small-sized blood vessels vasculitis, resulting from immunoglobulin A-mediated inflammation. It is the most common acute systemic vasculitis in childhood and mainly affects skin, gastrointestinal tract, joints and kidney. Skin lesions, usually presenting as erythematous maculopapules, petechiae, and purpura, often involve lower extremities and buttocks, but may also extend to the upper extremities, face and trunk. Conversely to adults, hemorrhagic bullous evolution has been seldom described in childhood. The pressure is likely a factor into the pathogenesis of bullae. We report on three new pediatric cases of HSP with hemorrhagic bullous skin lesions, and a review of the literature. Bullous evolution represents an unusual, but well-recognized cutaneous manifestation that may be a source of diagnostic dilemma, but does not seem to have any prognostic value in the outcome of HSP.     

Genetic polymorphisms and surface expression of CTLA-4 and PD-1 on T cells of silica-exposed workers

Exposure to silica dust has been examined as a possible risk factor for autoimmune diseases, including scleroderma, rheumatoid arthritis and systemic lupus erythematosus. Since CTLA-4 [CD152] and PD-1 [CD279] are important for the maintenance of peripheral tolerance by regulating T cell responsiveness, we evaluated the expression of these molecules on the surface of CD4 and CD8 T cells, as well as single nucleotide polymorphisms (SNP) in CTLA-4 and PDCD1 genes, of 70 silica-exposed workers and 30 non-exposed, age-, ethnically- and sex-matched controls. Expression of CTLA-4 was significantly (P<0.05) reduced in CD4 T cells of exposed individuals [median=0.1% and interquartile range, IQR 0.0-0.1% (exposed), median=0.20%, IQR 0.0-0.4% (control)]. Also the expression of PD-1 was significantly (P<0.0001) reduced in both CD4 [median=0.9%, IQR 0.4-2.3% (exposed), median=5.7%, IQR 1.4-13.3% (control)] and CD8 T cells [median=0.9%, IQR 0.3-1.9% (exposed), median=5.0%, IQR 3.4-8.9% (control)]. The study of polymorphisms demonstrated a lower frequency of the A allele in the analysis of the PD1.3 SNP in the exposed group, which might be associated with the lower expression of PD-1 on the surface of CD4 T cells. Our findings provide evidence for the association of silica exposure and the maintenance of self-tolerance, i.e., the susceptibility to autoimmune disorders.     

Spontaneous low cerebrospinal pressure: a mini review

Neurological Sciences - Spontaneous intracranial hypotension (SIH) is a syndrome of low cerebrospinal fluid (CSF) pressure characterised by postural headaches in patients without any history of...     

Aucte intermittent porphyria and epilepsy.

A 14-year-old boy had suffered from intermittent acute hepatic porphyria, myoclonic convulsions and mental retardation (Lennox-Gastaut syndrome). The porphyria was treated by stopping the administration of phenobarbitone and phenytoin. Sodium valproate at a dose of 70 mg/kg per day lessened the severity and frequency of convulsive crises.     

Expression of a metastatic phenotype in IFNs-primed/TNFα-activated B16 murine melanoma cells: role of JAK1/PKCδ signal transduction factors

In previous studies, we found that IFNγ and TNFα generated by activated macrophages stimulate the metastatic potential in F10-M3 cells, a clone isolated from B16-F10 murine melanoma line. In this phenomenon, TNFα promoted the expression of a metastatic phenotype in tumor cells previously primed with IFNγ. Here, we demonstrate that IFNα or IFNβ may replace IFNγ in priming tumor cells. We also noticed that an enhancement of the expression of p55TNFα receptor was associated with the preconditioning of tumor cells with IFNγ and IFNβ. By the use of an appropriate inhibitor, we observed that JAK1 signal transduction pathway was involved in the expression of a metastatic phenotype and of p55TNFα receptor shown in IFNγ- and IFNβ-primed melanoma cells stimulated with TNFα. Furthermore, the activity of the protein kinase C (PKC) was required for IFNγ-primed melanoma cells to express a metastatic phenotype after stimulation with TNFα. In conclusion, our study shows that a metastatic phenotype was expressed in B16 murine melanoma cells stimulated with TNFα regardless of whether the cells were primed with IFNγ IFNα or IFNβ. The molecular events leading to the expression of a metastatic phenotype in F10-M3 melanoma cells are represented by: (a) an enhanced expression of p55TNFα receptor in IFNs-primed tumor cells dependent on JAK1 signal transduction pathway; and (b) an intact PKC activity during TNFα stimulation.     

Bail-out intracranial stenting with Solitaire AB device after unsuccessful thrombectomy in acute ischemic stroke of anterior circulation

Background

Recent trials established the efficacy of mechanical stent-retriever thrombectomy for treatment of stroke patients with large vessel occlusion (LVO) in the anterior circulation. However, stent-retriever thrombectomy may not accomplish successful recanalization in all patients. The aim of this study is to report the role of bail-out permanent stenting after failure of mechanical thrombectomy.

Copolymerization of 1,3-dienes with CpTiCl3-MAO. Some cases in which the mode of monomer coordination affects the copolymer structure

The following pairs of monomers were copolymerized using the catalyst system CpTiCl₃/methylaluminoxane (MAO): 1,3-butadiene/(E)-1,3-pentadiene, 1,3-butadiene/4-methyl-1,3-pentadiene and 4-methyl-1,3-pentadiene/(Z)-1,3-pentadiene. The copolymers were characterized by NMR and infrared examination. 4-Methyl-1,3-pentadiene/(Z)-1,3-pentadiene and 1,3-butadiene/(E)-1,3-pentadiene gave copolymers having a composition intermediate between that of an ideal and that of an alternating copolymer. 1,3-Butadiene/4-methyl-1,3-pentadiene gave block copolymers only. These results have been interpreted on the basis of a different mode of coordination of the monomers. The cis-η⁴ coordination is by far the most stable for 1,3-butadiene and (E)-1,3-pentadiene, while for (Z)-1,3-pentadiene and 4-methyl-1,3-pentadiene there is probably an equilibrium between the cis-η⁴ and trans-η² form. Both these forms are reactive in the case of (Z)-1,3-pentadiene, while only the trans-η² form is so in the case of 4-methyl-1,3-pentadiene.