45 research outputs found
A solitary primary subcutaneous hydatid cyst in the abdominal wall of a 70-year-old woman: a case report
<p>Abstract</p> <p>Introduction</p> <p>A solitary primary hydatid cyst in the subcutaneous abdominal wall is an exceptional entity, even in countries where the <it>Echinococcus </it>infestation is endemic.</p> <p>Case presentation</p> <p>We report a case of a 70-year-old Caucasian woman who presented to our hospital with a subcutaneous mass in the para-umbilical area with a non-specific clinical presentation. The diagnosis of subcutaneous hydatid cyst was suspected on the basis of radiological findings. A complete surgical resection of the mass was performed and the patient had an uneventful post-operative recovery. The histopathology confirmed the suspected diagnosis.</p> <p>Conclusion</p> <p>Hydatid cyst should be considered in the differential diagnosis of every subcutaneous cystic mass, especially in regions where the disease is endemic. The best treatment is the total excision of the cyst with an intact wall.</p
A giant peritoneal simple mesothelial cyst: a case report
<p>Abstract</p> <p>Introduction</p> <p>A peritoneal simple mesothelial cyst is a very rare mesenteric cyst of mesothelial origin. The size of this lesion usually ranges between a few centimeters and 10 cm. It is usually asymptomatic, but occasionally presents with various, non-specific symptoms, which makes correct pre-operative diagnosis difficult. We present a case of a giant peritoneal simple mesothelial cyst that was successfully managed by complete surgical excision which is the treatment of choice.</p> <p>Case presentation</p> <p>A 21-year-old Caucasian Moroccan woman with vague abdominal discomfort and associated distention, during the previous 2 years, without other symptoms, presented to our hospital. Her past medical history was unremarkable. On physical examination, a mobile, painless and relatively hard abdominal mass was palpated. The laboratory examination and abdominal radiograph were unremarkable. Abdominal radiologic imaging showed a cystic mass of 35 × 20 × 10 cm that occupied the entire anterior and right abdominal cavity. Radical excision of the cyst was performed by midline laparotomy without any damage to the adjacent abdominal organs. The histopathological diagnosis was simple mesothelial cyst. The postoperative course was uneventful with no recurrence.</p> <p>Conclusion</p> <p><b>A </b>peritoneal simple mesothelial cyst is a quite rare abdominal tumor, that must always be considered in differential diagnosis of pelvic cystic lesions and other mesenteric cysts. The treatment of choice is the complete surgical excision of the cyst.</p
Enzymes from psychrophilic organisms
Psychrophilic organisms such as micro-organisms and other ectothermic species living in polar, deep- sea or any constantly low temperature environments, produce enzymes adapted to function at low temperature. These enzymes are characterized by a high catalytic efficiency at low and moderate temperatures but are rather thermolabile. Due to their high specific activity and their rapid inactivation at temperatures as low as 30 degrees C, they offer, along with the producing micro-organisms, a great potential in biotechnology. The molecular basis of the adaptation of cold cu-amylase, subtilisin, triose phosphate isomerase from Antarctic bacteria and of trypsin from fish living in North Atlantic and in Antarctic sea waters have been studied. The comparison of the 3D structures obtained either by protein modelling or by X-ray crystallography (North Atlantic trypsin) with those of their mesophilic counterparts indicates that the molecular changes tend to increase the flexibility of the structure by a weakening of the intramolecular interactions and by an increase of the interactions with the solvent. For each enzyme, the most appropriate strategy enabling it to accommodate the substrate at a low energy cost is selected. There is a price to pay in terms of thermosensibility because the selective pressure is essentially oriented towards the harmonization of the specific activity with ambient thermal conditions. However, as demonstrated by site-directed mutagenesis experiments carried out on the Antarctic subtilisin, the possibility remains to stabilize the structure of these enzymes without affecting their high catalytic efficiency
Structural Basis for Substrate Placement by an Archaeal Box C/D Ribonucleoprotein Particle
Insights into the structure and function of a guide RNP
Many different RNA species undergo nucleotide modifications at sites identified by guide small nucleolar ribonucleoprotein (snoRNP) particles. The co-crystal structure of two snoRNP proteins gives valuable clues into the workings of this system
Lysophosphatidic acid activates Arf6 to promote the mesenchymal malignancy of renal cancer
Acquisition of mesenchymal properties by cancer cells is critical for their malignant behaviour, but regulators of the mesenchymal molecular machinery and how it is activated remain elusive. Here we show that clear cell renal cell carcinomas (ccRCCs) frequently utilize the Arf6-based mesenchymal pathway to promote invasion and metastasis, similar to breast cancers. In breast cancer cells, ligand-activated receptor tyrosine kinases employ GEP100 to activate Arf6, which then recruits AMAP1; and AMAP1 then binds to the mesenchymal-specific protein EPB41L5, which promotes epithelial-mesenchymal transition and focal adhesion dynamics. In renal cancer cells, lysophosphatidic acid (LPA) activates Arf6 via its G-protein-coupled receptors, in which GTP-G alpha 12 binds to EFA6. The Arf6-based pathway may also contribute to drug resistance. Our results identify a specific mesenchymal molecular machinery of primary ccRCCs, which is triggered by a product of autotaxin and it is associated with poor outcome of patients