A novel helix termination mutation in keratin 10 in annular epidermolytic ichthyosis, a variant of bullous congenital ichthyosiform erythroderma

Annular epidermolytic ichthyosis is a distinct phenotypic variant of bullous congenital ichthyosiform erythroderma that has recently been described in two separate kindreds. Individuals with this variant present with bullous ichthyosis in early childhood and hyperkeratotic lichenified plaques in the flexural areas and extensor surfaces at later ages. Characteristically, they also develop intermittent bouts of annular and polycyclic, erythematous, scaly plaques on the trunk and proximal extremities. We now describe a third kindred with annular epidermolytic ichthyosis. Molecular analysis of this family revealed a novel mutation resulting in an isoleucine to threonine substitution at residue 107 (codon 446) within the highly conserved helix termination motif at the end of the rod domain of keratin 10.     

PURIFICATION OF THE CELLULAR RECEPTOR OF AN OYSTER JUICE BORNE COLIPHAGE OJ367 FROM THE OUTER MEMBRANE OF ESCHERICHIA COLI HOST

The cellular receptor of an oyster juice borne phage OJ367 was found in the outer membrane (OM) of its host Escherichia coli. The total cell envelope (TCE) was fractionated by differential extraction and it was found that the OM possesses phage neutralization ability. The OM was purified by diethylaminoethyl cellulose column chromatography to screen for the phage recognition moiety. A homogeneous, 39‐kDa OM protein (Omp) with receptor activity was eluted. It was a peptidoglycan (PG)‐associated protein which showed trypsin resistance. Lipopolysaccharide (LPS) had no effect on its receptor activity either when coexisting in the column fractions or when the isolated LPS was mixed with the Omp. Mutants resistant to lysis by phage OJ367 were isolated. The amount of the 39‐kDa and another PG‐associated 37‐kDa protein decreased significantly in the TCE of the mutant. The 39‐kDa Omp may serve as the cellular receptor for adherence of the coliphage, whereas the 37‐kDa protein is also involved in the infection mechanism.     

Forecasting user demand for wireless services: A socio-economic approach for Europe

This article reports the findings of a study for the European Commission to forecast demand for mobile communications services up to 2020. The study used a socio-economic approach including scenarios to explore the future and an original methodology for estimating traffic volumes under different socio-economic conditions. This article describes the objectives, outlines the methodology and summarises the results of the study. The study’s findings lay the foundation for a European consensus for calculating future spectrum requirements and are an important part of the process in the lead up to the World Radiocommunication Conference in 2007.     

Osteocalcin and osteonectin immunoreactivity in the diagnosis of osteosarcoma

Osteosarcomas (OSAs) can be difficult to distinguish histologically from tumors with significantly different biologic potentials and treatment protocols. The correct diagnosis of OSA relies on identification of malignant osteoblasts that are capable of producing neoplastic bone. To determine the use of immunohistochemistry for the diagnosis of OSA, 106 tumors from the Massachusetts General Hospital and the University of Vermont were immunostained with monoclonal antiosteocalcin (OC) and antiosteonectin (ON) antibodies. They included 42 OSAs, 25 non-bone-forming sarcomas, 24 other malignant tumors including lymphomas, carcinomas, and melanomas, and 15 benign bone tumors. Cytoplasmic staining with OC showed 70% sensitivity and 100% specificity, while staining with ON showed 90% sensitivity and 54% specificity for bone-forming tumors, consistently staining cell types other than osteoblasts. Of the OSAs, 83% demonstrated matrix staining with one or both antibodies, whereas dense collagen was negative for both antibodies in all tumors. We conclude that tumor cell cytoplasmic staining with monoclonal OC may be helpful in distinguishing OSAs from other malignancies, and staining of extracellular matrix for OC and ON antibodies concurrently may help distinguish bone matrix from dense collagen.     

Lipoblastoma. A rare, benign tumor in children

Lipoblastoma is a rare, benign tumour of embryonal fat seen almost exclusively in infancy and early childhood. It occurs mostly in the extremities, but it is also seen in other parts of the body. The tumour may grow rapidly, and the fact that lipoblastomas show immature fat cells could lead to the wrong diagnosis of liposarcoma. Complete surgical excision appears to be the treatment of choice. A correct, preoperative diagnosis is possible in most cases. Two cases of lipoblastoma of the upper limb and one case in the scapular region are reported.     

BLM (the causative gene of Bloom syndrome) protein translocation into the nucleus by a nuclear localization signal

Bloom syndrome (BS) is a rare genetic disorder characterized by small body size, sun sensitivity, immunodeficiency and a high predisposition to various types of cancer. BLM was identified as the causative gene for BS, and BLM protein is homologous to DNA helicase. There are two putative nuclear localization signals (NLSs) within amino acid residues 1334-1349 in the C-terminus of the BLM protein, which has the distinctive structure of two basic residue arms separated by a spacer. The entire coding or deleted BLM sequences of various sizes were ligated into an enhanced green fluorescent protein (EGFP) vector and transfected into HeLa cells. The EGFP vector harboring the entire BLM coding sequence was transported to the nucleus. The BLM protein truncated at 1341 amino acid, containing an intact helicase domain and only one proximal arm, was not transported to the nucleus. The BLM protein truncated at 1357 amino acid, containing an intact helicase domain and two arms, was transported to the nucleus. The EGFP vector harboring DNA fragments encoding a protein having only the distal arms of basic amino acids in the C-terminus was also transported to the nucleus. The truncated BLM proteins corresponding to previously reported mutated BLM proteins were retained in the cytoplasm or both the cytoplasm and the nucleus as was the EGFP vector with no insert. These results show that the BLM protein translocates into the nucleus and that the distal arm of the bipartite basic residues in the C-terminus of the BLM protein is essential for targeting the nucleus.