Chondroblastoma: a clinico-pathological analysis.

Objective: To determine the clinico-pathological and histological features of Chondroblastoma (CB).

Study Design: Case series.

Place And Duration Of Study: The Aga Khan University Hospital, Karachi, from 2000 to 2013.

Exploring the sequence context of phosphorylatable amino acids: the contribution of the upgraded MAPRes tool.

Several models that predict where post-translational modifications are likely to occur and formulate the corresponding association rules are available to analyze the functional potential of a protein sequence, but an algorithm incorporating the functional groups of the involved amino acids in the sequence analyses process is not yet available. In its previous version, MAPRes was utilized to investigate the influence of the surrounding amino acids of post- translationally and co-translationally modifiable sites. The MAPRes has been upgraded to take into account the different biophysical and biochemical properties of the amino acids that have the potential to influence different post- translational modifications (PTMs).

Influence of the sequence environment and properties of neighboring amino acids on amino-acetylation: relevance for structure-function analysis.

Proteins function is regulated by co-translational modifications and post-translational modifications (PTMs) such as phosphorylation, glycosylation, and acetylation, which induce proteins to perform multiple tasks in a specified environment. Acetylation takes place post-translationally on the ε-amino group of Lys in histone proteins, allowing regulation of gene expression. Furthermore, amino group acetylation also occurs co-translationally on Ser, Thr, Gly, Met, and Ala, possibly contributing to the stability of proteins.

Post-translational modifications in activation and inhibition of Oct-1-DNA binding complex in H2B and other diverse gene regulation: prediction of interplay sites.

Octamer DNA binding transcription factors play important roles in housekeeping and specific gene regulations. Octamer DNA binding transcription factor-1 (Oct-1), expressed ubiquitously, is a multifunctional molecule. The binding sites of Oct-1 are the promoters of H2B gene and the genes of snRNA, U2, U6, and 7SK, yet Oct-1 has been described as constitutively expressed transcription factor regulating the expression of housekeeping genes.

Pulmonary hyalinising granuloma: a rare pulmonary disorder.

Pulmonary hyalinising granulomas are rare, noninfectious fibrosclerosing lesions of the lung which can mimic metastatic disease. It was first described in literature by Engleman et al in the year 1977. Its etiology is unknown but they may be caused by an exaggerated immune response.

Sclerosing mesenteritis as a cause of abdominal mass and discomfort in an elderly patient: a case report and literature review.

Sclerosing mesenteritis is a rare benign process that involves inflammation, fat necrosis, and fibrosis of the mesentery. The disease poses great diagnostic challenge due to its nonspecific clinical and diagnostic findings. We report the case of a 75-year-old man who presented with vague abdominal discomfort associated with an intra-abdominal mass.

Generalized cutaneous granulocytic sarcoma with joint involvement.

Granulocytic sarcoma (GS) is a rare extra medullary solid tumour composed of immature myeloid cells. These tumours often display a greenish colour due to the enzymatic action of myeloperoxidase in the tumour cells. Hence, the term 'chloroma' was given to this lesion in 1853.

Epidermal growth factor receptors: function modulation by phosphorylation and glycosylation interplay.

Post-translational modifications (PTMs) of proteins induce structural and functional changes that are most often transitory and difficult to follow and investigate in vivo. In silico prediction procedures for PTMs are very valuable to foresee and define such transitory changes responsible for the multifunctionality of proteins. Epidermal growth factor receptor (EGFR) is such a multifunctional transmembrane protein with intrinsic tyrosine kinase activity that is regulated primarily by ligand-stimulated transphosphorylation of dimerized receptors.

In silico modulation of HMGN-1 binding to histones and gene expression by interplay of phosphorylation and O-GlcNAc modification.

Utilizing different computational methods; phosphorylation, O-GlcNAc modification and Yin Yang sites are predicted in HMGN-1. Prediction results suggest that interplay of phosphorylation and O-GlcNAc modification regulates binding and removal of HMGN-1 with the nucleosome and its translocation from nucleus to cytoplasm and back to nucleus, consequently modulating gene expression.

Immediate-early gene regulation by interplay between different post-translational modifications on human histone H3.

In mammalian cells, induction of immediate-early (IE) gene transcription occurs concomitantly with histone H3 phosphorylation on Ser 10 and is catalyzed by mitogen-activated protein kinases (MAPKs). Histone H3 is an evolutionarily conserved protein located in the core of the nucleosome, along with histones H2A, H2B, and H4. The N-terminal tails of histones protrude outside the chromatin structure and are accessible to various enzymes for post-translational modifications (PTM).

Oct-2 DNA binding transcription factor: functional consequences of phosphorylation and glycosylation.

Phosphorylation and O-GlcNAc modification often induce conformational changes and allow the protein to specifically interact with other proteins. Interplay of phosphorylation and O-GlcNAc modification at the same conserved site may result in the protein undergoing functional switches. We describe that at conserved Ser/Thr residues of human Oct-2, alternative phosphorylation and O-GlcNAc modification (Yin Yang sites) can be predicted by the YinOYang1.

Role of sialic acid and sulfate groups in cervical mucus physiological functions: study of Macaca radiata glycoproteins.

The influence of charged groups in glycoproteins was investigated to assess their effect on the physiological functions of bonnet monkey cervical mucus. The macromolecular glycoproteins from peri-ovulatory, midcycle phase cervical mucus were treated with Pronase, trypsin and chymotrypsin and the enzyme-resistant glycoproteins purified by gel filtration on Sepharose 4B and a high molecular weight component containing carbohydrates, proteins and sulfate groups was recovered in high yield. This material still reacted with an antiserum directed against purified midcycle glycoprotein but not against another antiserum directed against luteal phase purified glycoproteins.

Plasmodium falciparum merozoite surface protein 1.

In addition to the major carbohydrate moieties of the glycosylphosphatidylinositol (GPI) anchor, we report that Plasmodium falciparum merozoite surface protein 1 (MSP-1) bears O-GlcNAc modifications predominantly in beta-anomeric configuration, in both the C- and N-terminal portions of the protein. Subcellular fractionation of parasitized erythrocytes in the late trophozoite/schizont stage reveals that GPI-anchored C-terminal fragments of MSP-1 are recovered in Triton X-100 resistant, low-density membrane fractions. Our results suggest that O-GlcNAc-modified MSP-1 N-terminal fragments tend to localize within the parasitophorous vacuolar membrane while GPI-anchored MSP-1 C-terminal fragments associate with low-density, Triton X-100 resistant membrane domains (rafts), redistribute in the parasitized erythrocyte and are eventually shed as membrane vesicles that also contain the endogenous, GPI-linked CD59.

Signaling through sphingolipid microdomains of the plasma membrane: the concept of signaling platform.

Transmembrane signaling requires modular interactions between signaling proteins, phosphorylation or dephosphorylation of the interacting protein partners and temporary elaboration of supramolecular structures, to convey the molecular information from the cell surface to the nucleus. Such signaling complexes at the plasma membrane are instrumental in translating the extracellular cues into intracellular signals for gene activation. In the most straightforward case, ligand binding promotes homodimerization of the transmembrane receptor which facilitates modular interactions between the receptor's cytoplasmic domains and intracellular signaling and adaptor proteins.

Carbohydrate moiety of Plasmodium falciparum glycoproteins: the nature of the carbohydrate-peptide linkage in the MSP-2 glycoprotein.

Metabolic labelling of Plasmodium falciparum parasites with [3H]GlcN, [3H]Man, [3H]Gal and [3H]ethanolamine, and subsequent purification by SDS-PAGE of the labelled material provided effective labelling of the MSP-1, 195 kDa, and MSP-2, 42-53 kDa, glycoproteins. Reductive beta-elimination of the MSP-2 released from the gel consisted of glycopeptides containing labelled sugars. Processing of the eliminated components and identification of the sugar residues demonstrated the presence of N-acetylglucosaminitol and N-acetylgalactosaminitol amongst other labelled sugars.

Corticosteroid use and abuse by medical practitioners for arthritis and related disorders in Pakistan.

A total of 256 consecutive patients attending our out-patient clinic in Islamabad, Pakistan, with complaints of pain in or around the joints were evaluated for use of corticosteroids prescribed by medical practitioners they had seen earlier. The appropriateness of such prescriptions and their consequent effects were assessed. Of the 256 patients, 110 (i.

Integration of mycobacterial lipoarabinomannans into glycosylphosphatidylinositol-rich domains of lymphomonocytic cell plasma membranes.

Lipoarabinomannans (LAMs) are major Ags of the mycobacterial cell envelope where they apparently insert through a glycosylphosphatidylinositol (GPI) anchoring structure. LAMs induce host macrophages to secrete TNF-alpha, IL-1, and IL-6 and inhibit T cell proliferative responses. The mechanisms by which LAMs mediate these effects remain poorly understood.

A water-soluble fragment of Micrococcus lysodeikticus cell wall.

A fragment of Micrococcus lysodeikticus cell wall was obtained by extraction of walls with water, dimethylformamide or dimethyl sulfoxide. The water-soluble polymer was obtained from the cell walls prepared either with or without trypsin treatment of the cell. This fragment was studied by the Smith periodate oxidation, methylation, mild acid treatment and enzymic procedures.