Radiotherapy-induced pemphigus vulgaris with autoantibodies targeting a 110 kDa epidermal antigen

Background Pemphigus is an autoimmune intraepidermal blistering disease mediated by autoantibodies targeting desmosomes. It can be induced by many triggers, such as ionizing radiation. Methods We report a case of radiotherapy‐induced pemphigus (RIP) with a review of the published cases in the English and French literature. Results A 61‐year old man was diagnosed to have epidermoid carcinoma of the piriform sinus and then received a 70 Gy radiation therapy. One month after the treatment completion, multiple blisters and erosions occurred initially on the site of irradiation, then in other skin areas. Histological examination showed an intraepidermal blister with acantholysis and necrosis of individual keratinocytes. Direct immunofluorescence and indirect immunofluorescence were typical of pemphigus. Immunoblot revealed antibodies reacting with a 110 kDa antigen. This feature was consistent with the diagnosis of RIP. Less than 20 cases of RIP have been reported previously. Mean age at diagnosis was 64.2 years, and there is a slight female preponderance. RIP occurred, in most cases, initially within the area of irradiation. Conclusion Our patient showed some distinctive findings never reported previously in RIP: a histological focal keratinocyte necrosis, and the presence of autoantibodies reacting with a 110 kDa keratinocytic protein in immunoblot analysis. Because of a different prognosis, it is important to differentiate RIP and paraneoplastic pemphigus (PNP), although cases of ionizing radiation‐induced PNP had also been described. As in our patient, RIP seems to respond well to systemic corticosteroids and immunosuppressive therapy, which induce remission within a few months.     

Penile shaft involvement in pityriasis versicolor

The Malassezia yeasts are among the normal human cutaneous flora in adults. They are also reported as part of the microflora of male genital region, mostly in uncircumcised males. The prevalence of Malassezia yeast colonization on the glans penis of circumcised males is discussed in multiple studies. We report the case of a male patient with extensive pityriasis versicolor that does not involve the preputial space.     

Angiomatoid tumor of the thyroid gland: primitive angiosarcoma or variant of anaplastic carcinoma?

Thyroid gland angiomatoid tumors are an extremely aggressive neoplasms with varied histological patterns and features of endothelial differentiation. The histogenesis of thyroid angiomatoid tumors has been controversial for many years: these tumors may be either a variant of anaplastic carcinoma, or an angiosarcoma. We report a case of thyroid angiomatoid tumor in a 68-year-old woman. We also discuss, through a review of the literature, the pathologic criteria that could be used to distinguish between angiosarcoma and anaplastic carcinoma of the thyroid.     

Outbreak of Imported Seventh Pandemic Vibrio cholerae O1 El Tor,Algeria, 2018

After a lull of >20 years, Algeria experienced a cholera outbreak in 2018 that included 291 suspected cases. We found that outbreak isolates were Vibrio cholerae O1 serotype Ogawa from seventh pandemic El Tor sublineage AFR14, which corresponds to a new introduction of cholera into Africa from South Asia.     

Differential modulation of nuclear texture, histone acetylation, and MDR1 gene expression in human drug-sensitive and -resistant OV1 cell lines

Image cytometric study of pathological specimens or cell lines has suggested that epigenetic mechanisms are likely to play a major role in determining chromatin patterns evaluable through nuclear texture analysis. We previously reported that nuclear textural changes observed in the OV1-VCR etoposide-resistant ovarian carcinoma cell line were associated with an increased acetylated histone H4 level. In this study we analyzed the effects of treatments with the HDAC inhibitor trichostatin A (TSA) or with nickel subsulfide on histone H4 acetylation, nuclear texture, and MDR1 gene expression in drug-sensitive IGROV1 and drug-resistant OV1-VCR cell lines. In IGROV1 cells, TSA induced an increase in acetylated H4 level associated with a chromatin textural decondensation and an increase in MDR1 gene expression. In OV1-VCR cells, a similar increase in H4 acetylation was observed, but nuclear texture or MDR1 gene expression remained unchanged. ChIP analysis revealed that MDR1 gene expression remained stable in TSA-treated OV1-VCR cells despite a localized increase in H4 acetylation at the promoter level. Analysis of the methylation status of MDR1 promoter showed an increase in DNA methylation at 3 specific sites in OV1-VCR cells, that could participate to TSA low responsiveness in these cells. Treatment with nickel subsulfide induced a decrease in H4 acetylation without any effect on nuclear texture characteristics in both cell lines. In OV1-VCR cells, nickel subsulfide induced a significant down-regulation of the MDR1 gene expression. These results indicate that modulation of histone H4 acetylation level can be associated with up- or down-regulation of the MDR1 gene in OV1 cells. However, this modulation does not always result in chromatin pattern alterations and these data emphasize the complexity of chromatin texture regulation in tumor cells.     

Aging and Cardiovascular Disease: An Unusual Presentation of Mycotic Popliteal Artery Pseudoaneurysm due to Pasteurella multocida Infection

Pasteurella multocida , a zoonotic infectious pathogen, is a rare cause of mycotic aneurysms in human hosts. A 76-year-old man was admitted at our emergency unit for a superinfection of his right limb. The patient was initially treated for a knee arthritis. After a first-line antibiotherapy, the patient was referred to the vascular department for the management of a right acute limb ischemia. The work-up revealed a ruptured pseudoaneurysm of the popliteal artery. The ruptured artery was surgically explanted, and a femoropopliteal bypass was then performed. Pasteurella multocida was detected after bacterial analysis of the aneurysm. The postoperative course was uneventful. This case is the first reported case, to our knowledge, of a popliteal artery pseudoaneurysm due to Pasteurella multocida infection.     

Glycosaminoglycans and protein disulfide isomerase-mediated reduction of HIV Env

Conformational changes within the human immunodeficiency virus-1 (HIV-1) surface glycoprotein gp120 result from binding to the lymphocyte surface receptors and trigger gp41-mediated virus/cell membrane fusion. The triggering of fusion requires cleavage of two of the nine disulfide bonds of gp120 by a cell-surface protein disulfide-isomerase (PDI). Soluble glycosaminoglycans such as heparin and heparan sulfate bind gp120 via V3 and, possibly, a CD4-induced domain. They exert anti-HIV activity by interfering with the HIV envelope glycoprotein (Env)/cell-surface interaction. Env also binds cell-surface glycosaminoglycans. Here, using surface plasmon resonance, we observed an inverse relationship between heparin binding by gp120 and its thiol content. In vitro, and in conditions in which gp120 could bind CD4, heparin and heparan sulfate reduced PDI-mediated gp120 reduction by approximately 80%. Interaction of Env with the surface of lymphocytes treated using sodium chlorate, an inhibitor of glycosaminoglycan synthesis, led to gp120 reduction. We conclude that besides their capacity to block Env/cell interaction, soluble glycosaminoglycans can effect anti-HIV activity via interference with PDI-mediated gp120 reduction. In contrast, their presence at the cell surface is dispensable for Env reduction during the course of interaction with the lymphocyte surface. This work suggests that the reduction of exofacial proteins in various diseases can be inhibited by compounds targeting the substrates (not by targeting PDI, as is usually done), and that glycosaminoglycans that primarily protect proteins by preserving them from proteolysis also have a role in preventing reduction.