Transorbital penetrating head injury with a hunting arrow: Case report

The development of more complex and diverse hunting weapons may result in an increase of uncommon forms of penetrating injury to the brain. We present a case of non-fatal transorbital arrow injury to the brain. High velocity projectile injuries merit certain management adaptations from gunshot or low velocity stab wounds. This case highlights the necessity for anterograde removal of the arrow in the direction of its line of trajectory. Early assessment of the patient with cerebral angiography to identify surgically correctable vascular injury is recommended.     

Surgery for fistula-in-ano: an audit of practise of colorectal and general surgeons.

Objective Some conditions, previously managed by general surgeons, may be treated more successfully by colorectal specialists. This argument is well established for rectal cancer but does it also apply to benign conditions? This study compares the treatment strategies and outcomes for fistulae‐in‐ano by general and colorectal surgeons in a district general hospital. Method Patients who had surgery for fistula‐in‐ano from January 1992–October 2003 were identified from theatre records. Case notes were reviewed for data on type of fistula, aetiology, surgery performed and recurrence. All patients were sent a questionnaire requesting details of recurrence and incontinence. The severity of incontinence was assessed using the Faecal Incontinence Quality of Life Scale (FIQOLS) and the Faecal Incontinence Severity Index (FISI). Results Eighty four patients (male = 53) were identified. Colorectal surgeons performed surgery in 34 and general surgeons in 50 patients. These groups were comparable with terms of age, gender, aetiology (colorectal: IBD = 5, cryptoglandular = 21: general IBD = 14, cryptoglandular = 24; P = 0.28; Chi‐squared test), and type of fistulae (colorectal: inter‐sphincteric = 20, trans‐sphincteric = 13: general inter‐sphincteric = 30, trans‐sphincteric = 18: P = 1.0; Fisher's exact test). Colorectal surgeons carried out fewer fistulotomies (47.1%vs 84.0%; P < 0.001; Fisher's exact test), more staged fistulotomies with Setons (44.1%vs 10.0%: P < 0.001; Fisher's exact test), and had fewer recurrences (9.7%vs 30.0%: P < 0.05; Fisher's exact test) when compared with general surgeons. Five patients with recurrence from the general surgery group were subsequently referred to the colorectal surgeons; four patients had further surgery (fistulotomy = 2; staged fistulotomy = 2) with no recurrence to date; one patient required proctectomy. Forty seven (64.4%) patients answered the questionnaire. There was no difference between patients operated on by colorectal or general surgeons with regards the frequency (43.5%vs 62.5%: P = 0.25; Fisher's exact test) or severity [FISI 26 (21–38); median (inter‐quartile range) vs 26 (17–38); median (inter‐quartile range: P = 0.85; Mann–Whitney test) of faecal incontinence. There was no difference between the groups with regards any of the four scales that comprised the FIQOLS. Conclusions The number of included patients is far too low to draw any conclusions but there were some interesting trends. For similar patient samples, colorectal surgeons seem to adopt a more conservative approach and have fewer recurrences than general surgeons. These differences are not reflected in the frequency or severity of postoperative incontinence.     

Low-artifact intravascular devices: MR imaging evaluation

Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible.     

Electrochemical release testing of nickel-titanium orthodontic wires in artificial saliva using thin layer activation

Alloys based on Ni–Ti intermetallics generally exhibit special shape memory and pseudoelastic properties, which make them desirable for use in the dental field as orthodontic wires. The possibility of nickel release from these materials is of high concern, because the allergenicity of this element. The aim of this study was to test pseudoelastic Ni–Ti wires in simulated physiological conditions, investigating the combined effect of strain and fluoridated media: the wires were examined both under strained (5% tensile strain) and unstrained conditions, in fluoridated artificial saliva at 37 °C. Real time electrochemical nickel release testing was performed using a novel application of a radiotracer based method, thin layer activation (TLA). TLA was validated, in unstrained conditions, against adsorptive stripping voltammetry methodology. Control tests were also performed in non-fluoridated artificial saliva. From our research it transpired that the corrosion behaviour of Ni–Ti alloy is highly affected by the fluoride content, showing a release of 4.79 ± 0.10 μg/cm²/day, but, differently from other biomaterials, it does not seem to be affected by elastic tensile strain. The application of the TLA method in the biomedical field appears a suitable technique to monitor in real time the corrosion behaviour of biomedical devices.     

The interaction of CD4 with CD3/Ti regulates tyrosine phosphorylation of substrates during T cell activation

Phosphorylation of proteins on tyrosine residues during activation was studied in CD3+ CEM T cells. Crosslinking of either CD4 alone or CD3/Ti alone induced weak and transient responses, but the patterns of induced tyrosine-phosphorylated proteins were different. A synergistic but still transient response occurred by the specific interaction of CD4 with CD3/Ti, whereas simultaneous but separate ligation of CD3/Ti and CD4 decreased rather than increased tyrosine phosphorylation of proteins in comparison to CD3/Ti stimulation alone. Stimulation of T cells with immobilized anti-CD3 induced strong and prolonged tyrosine phosphorylation of distinct substrates. CD4 therefore regulates protein tyrosine kinase activation by specific interaction with CD3/Ti, whereas immobilized anti-CD3 may differ from anti-CD3 in solution in the activation of protein tyrosine phosphatase(s) such as CD45.