An oncogenetic tree model in gastrointestinal stromal tumours (GISTs) identifies different pathways of cytogenetic evolution with prognostic implications

To model the cytogenetic evolution in gastrointestinal stromal tumour (GIST), an oncogenetic tree model was reconstructed using comparative genomic hybridization data from 203 primary GISTs (116 gastric and 87 intestinal GISTs, including 151 newly analysed cases), with follow-up available in 173 cases (mean 40 months; maximum 133 months). The oncogenetic tree model identified three major cytogenetic pathways: one initiated by -14q, one by -1p, and another by -22q. The -14q pathway mainly characterized gastric tumours with predominantly stable karyotypes and more favourable clinical course. On the other hand, the -1p pathway was more characteristic of intestinal GISTs, with an increased capacity for cytogenetic complexity and more aggressive clinical course. Loss of 22q, more closely associated with -1p than -14q, appeared to initiate the critical transition to an unfavourable cytogenetic subpathway. This -22q pathway included accumulation of +8q, -9p, and -9q, which could all predict disease-free survival in addition to tumour site. Thus, insights into the cytogenetic evolution obtained from oncogenetic tree models may eventually help to gain a better understanding of the heterogeneous site-dependent biological behaviour of GISTs.     

Systemic use of non‐biologic corticosteroids in orofacial diseases

Systemic non‐biologic agents have long been in clinical use in medicine – often with considerable efficacy, albeit with some adverse effects – as with all medications. With the advent of biologic agents, all of which currently are restricted to systemic use, there is a growing need to ensure which agents have the better therapeutic ratio. The non‐biologic agents (NBAs) include a range of agents, most especially the corticosteroids (corticosteroids). This study reviews the corticosteroids in systemic use in management of orofacial mucocutaneous diseases; subsequent studies discuss corticosteroid‐sparing agents used in the management of orofacial diseases, such as calcineurin inhibitors used to produce immunosuppression; purine synthetase inhibitors; and cytotoxic and other immunomodulatory agents.     

Hydrocelectomy under local anaesthesia in a Nigerian adult population

Background

Hydrocele is abnormal collection of serous fluid in the tunica vaginalis or a patent processus vaginalis. It is commonly encountered in our practice and often requires surgical treatment. However in our setting and in many underdeveloped countries, availability of general anaesthetic service is poor due to lack of trained personnel and equipment.

Objectives

To ascertain the practicability and acceptability of hydrocelectomy under sedation and local anaesthesia in Nigerian adults with hydrocele

Patients and Methods

A prospective study was carried out over a two year period on patients that had hydrocelectomy at the surgery unit of the Obafemi Awolowo University Teaching Hospitals Complex, Wesley Guild Hospital, Ilesa. Consecutive patients with diagnosis of hydrocele who consented had hydrocelectomy using intramuscular diazepam sedation and spermatic-cord block with 0.5% plane xylocaine and the scrotum infiltrated with same along the line of incision.

Results

Fifty adult patients were studied: age range 15–94 years. Eighty percent of the patients had unilateral hydrocele and the commonest type was vaginal hydrocele (94%). All patients had hydrocelectomy, 96% were under local anaesthesia while 4% were converted to general anaesthesia. All patients except one prefer to have future surgery under such local anaesthesia and sedation.

Conclusion

Hydrocelectomy under local anaesthesia and sedation is practicable and was tolerated and accepted by the adults patients studied.     

Genetically engineered gold-binding polypeptides: structure prediction and molecular dynamics

The biological control of inorganic crystal formation, morphology, and assembly is of interest to biologists and biotechnologists studying hard tissue growth and regeneration, as well as to materials scientists using biomimetic approaches for the control of inorganic material fabrication and assembly. Biomimetics requires an accurate understanding of natural mechanisms at the molecular level. Such understanding can be derived from the use of metal surfaces to study surface recognition by proteins together with combinatorial genetics techniques for the selection of suitable peptides. Polymerization of these peptides produces engineered polypeptides large enough to encode their own folding information with low structural complexity, while enhancing binding affinity to surfaces. The low complexity of such polypeptides can aid in analyses, leading to modeling and eventual manipulation of the structure of the folded polypeptide. This paper presents structure predictions for gold-binding protein sequences, originally selected by combinatorial techniques. Molecular dynamics simulations lasting 5 ns were carried out using solvated polypeptides at the gold surface to assess the dynamics of the binding process and the effects of surface topography on the specificity of protein binding.