Convergent signaling pathways—interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation

Oxidation of methionine (Met) to Met sulfoxide (MetSO) is a frequently found reversible posttranslational modification. It has been presumed that the major functional role for oxidation-labile Met residues is to protect proteins/cells from oxidative stress. However, Met oxidation has been established as a key mechanism for direct regulation of a wide range of protein functions and cellular processes. Furthermore, recent reports suggest an interaction between Met oxidation and O-phosphorylation. Such interactions are a potentially direct interface between redox sensing and signaling, and cellular protein kinase/phosphatase-based signaling. Herein, we describe the current state of Met oxidation research, provide some mechanistic insight into crosstalk between these two major posttranslational modifications, and consider the evolutionary significance and regulatory potential of this crosstalk.     

Osteosarcoma with cutaneous metastases. A case report

BACKGROUND: Osteosarcomas, despite their aggressive nature and propensity to metastasize, only rarely give rise to skin deposits. CASE: We report a case of a femoral osteosarcoma in which cutaneous scalp and neck metastases developed 3 years after treatment of the primary disease. Fine needle aspiration was pivotal in diagnosing the secondary disease. CONCLUSION: Only 8 instances of cutaneous metastases from an osteosarcoma have been previously reported. We recommend early investigation of such nodules with fine needle aspiration cytology and inclusion of multiagent chemotherapy as part of the treatment protocol in all patients with osteosarcoma.     

Acantholytic cells exfoliated from pemphigus vulgaris of the uterine cervix. A case report

BACKGROUND: Pemphigus vulgaris of the uterine cervix is rare and almost always associated with cutaneous or mucosal lesions elsewhere on the body. Without a history of pemphigus, acantholytic cells in cervical smears may be misdiagnosed as malignant ones. CASE: A 52-year-old female presented with a vaginal discharge, and a routine cervical smear was collected for cytology. The smear displayed atypical cells lying singly and in loose clusters, having vesicular nuclei, a thin nuclear membrane, prominent nucleoli and well-defined cytoplasmic margins. These were labeled atypical glandular cells of undetermined significance, and colposcopic examination and biopsy were advised. On colposcopy vesicular lesions and erosions were noticed on the cervix. The biopsy revealed typical intact as well as denuded suprabasal bullae of pemphigus vulgaris. On reevaluation of the cytologic smear, the cytomorphologic features correlated well with the acantholytic cells of pemphigus. Thorough reexamination of the patient revealed 2 tiny vesicles on the oral mucosa that, on biopsy, confirmed the diagnosis of pemphigus vulgaris. CONCLUSION: Cytopathologists should be aware of the typical cytomorphologic features of pemphigus vulgaris and, in an appropriate clinical setting, should be able to diagnose or at least suspect this entity in even rare sites like the cervix. A false positive diagnosis of malignancy can be avoided if the cytologic findings are judiciously correlated with the history and with clinical and colposcopic examinations.     

Multilocus Sequence Typing of Clinical Isolates of Cryptococcus from India

Mycopathologia - Cryptococcosis is a life-threatening infection caused by Cryptococcus neoformans and C. gattii species complex. In the present study, to understand the molecular epidemiology of...