Chronic orbital infection caused by migration of an orbital Silastic implant.

A Silastic sheet was used for the repair of a lateral orbital wall defect in a 48-year-old man. Migration of this implant through the defect has caused recurrent episodes of orbital infection. Although migration of Silastic within the orbit has been reported previously, the absence of fixation together with further remodelling of the lateral orbital wall defect contributed to this phenomenon.

Dopamine modulates acute responses to cocaine, nicotine and ethanol in Drosophila.

BACKGROUND: Drugs of abuse have a common property in mammals, which is their ability to facilitate the release of the neurotransmitter and neuromodulator dopamine in specific brain regions involved in reward and motivation. This increase in synaptic dopamine levels is believed to act as a positive reinforcer and to mediate some of the acute responses to drugs. The mechanisms by which dopamine regulates acute drug responses and addiction remain unknown. RESULTS: We present evidence that dopamine plays a role in the responses of Drosophila to cocaine, nicotine or ethanol. We used a startle-induced negative geotaxis assay and a locomotor tracking system to measure the effect of psychostimulants on fly behavior. Using these assays, we show that acute responses to cocaine and nicotine are blunted by pharmacologically induced reductions in dopamine levels. Cocaine and nicotine showed a high degree of synergy in their effects, which is consistent with an action through convergent pathways. In addition, we found that dopamine is involved in the acute locomotor-activating effect, but not the sedating effect, of ethanol. CONCLUSIONS: We show that in Drosophila, as in mammals, dopaminergic pathways play a role in modulating specific behavioral responses to cocaine, nicotine or ethanol. We therefore suggest that Drosophila can be used as a genetically tractable model system in which to study the mechanisms underlying behavioral responses to multiple drugs of abuse.

Multiple DNA processing reactions underlie Tn7 transposition.

The bacterial transposon Tn7 uses a cut and paste mechanism to translocate between non-homologous insertion sites. In the first step of recombination, double-strand breaks at each transposon end disconnect the element from the donor backbone; in the second step, the now exposed 3' transposon ends join to the target DNA. To dissect the chemical steps in these reactions, we have used mutant transposons altered at and near their extreme termini. We find that the initiating double-strand breaks result from a collaboration of two distinct DNA strand processing activities, one mediating cleavages at the 3' ends of Tn7, which can be blocked by changes at the transposon tips, and another mediating cleavages at the 5' ends. The joining of exposed 3'transposon ends to the target DNA can be blocked by changing the transposon tips. Our results suggest that the target joining step occurs through two usually concerted, but actually separable, reactions in which individual 3' transposon ends are joined to separate strands of the target DNA. Thus Tn7 transposition involves several distinct DNA processing reactions: strand cleavage and strand transfer reactions at the 3' ends of the transposon, and separate strand cleavage reactions at the 5' ends of the transposon.

Intravascular infection with Lactobacillus paracasei.

A patient is described with sub acute but life-threatening intravascular infection with Lactobacillus paracasei. Intrasplenic rupture of a mycotic aneurysm led to haematoma and early abscess formation with some bleeding into the peritoneum. The infection was cured with splenectomy and a prolonged course of ampicillin and gentamicin.

Bradycardia and the trigeminal nerve.

A review of the literature suggests that the oculocardiac reflex is part of a wider phenomenon involving any structure supplied by the trigeminal nerve. This can lead to potentially fatal complications in maxillofacial surgery. A review of the literature is discussed and two further cases are reported.

Extrusion of a microplate: an unusual complication of osteosynthesis.

A case is presented of an unusual complication of internal fixation of a midfacial fracture; the spontaneous extrusion of a microplate.

Improvements in morbidity of mouth cancer using microvascular free flap reconstructions.

50 patients who underwent major surgery for head and neck cancer and reconstructed with radial forearm microvascular free flaps, were assessed with regard to social adaptation, appearance and in particular mouth function. The results were compared with a similar group of patients who underwent reconstruction with either primary repair or pedicled flaps.

An audit of 50 bitemporal flaps in primary facial trauma.

The bitemporal (bicoronal) flap is a well recognised technique for exposing the skull and upper face. Prospectively collected data over a 5-year period in which this technique was used for access in primary craniomaxillofacial trauma was analysed. Emphasis was placed on indications, complications and outcome. A total of 50 cases were audited. 84% were male. 74% had sustained midface or frontal bone trauma, 24% had lateral upper face injuries. Only 1 patient had a penetrating missile injury. Consistent complications of the procedure were altered sensation at the vertex in the early postoperative period and a small area of wound breakdown over the suture knot in the galea. In all cases the altered sensation greatly improved or resolved, 12% developed a wound infection, however, 83% of these were trivial requiring no active treatment. There was an isolated case of pressure necrosis over a drain site. 12% had a demonstrable transient deficit of the temporal branch of the facial nerve, all of which improved.

Multipoint fixation at the frontozygomatic suture with microplates: a technical note.

A method using side-by-side microplates to create stable multipoint fixation at the frontozygomatic suture in the treatment of a subgroup of displaced zygomatic-orbital fractures is described.

Sialolithiasis of an accessory salivary gland.

Sialolithiasis is the occurrence of calcified masses within salivary ducts or glands, formed by deposition of calcium salts around a central nidus of organic material. A case is reported which affected an accessory salivary gland of the upper lip.

The Broadgreen osteotomy splint.

A modification is suggested to the standard cast metal cap splint which allows accurate and easier localisation in the operative and post-operative phases.

Sinus arrest complicating a bitemporal approach to the treatment of pan-facial fractures.

Two cases are reported in which the treatment of pan-facial fractures via a bi-temporal flap approach was complicated by cessation of activity of the sinuatrial node (sinus arrest). The anatomical, physiological and anaesthetic implications of this potentially fatal complication are discussed.

Assessment of the sinus lift operation by magnetic resonance imaging.

Sinus lift operations are done to increase bone thickness before placement of osseointegrated implants in areas of the maxilla where there is insufficient bone between the lower border of the maxillary sinus mucosa and the oral mucoperiosteum. Full sectional information should be available to the surgeon before the sinus lift operation so that the outcome can be predicted, and to allow for assessment of the volume of bone graft required. It is also useful to assess the success of the procedure before placement of the implant, and to choose the implant length and orientation required for maximum stability. We describe the use of a 0.2 tesla magnetic resonance imaging (MRI) scanner to image a patient before and after sinus lift. MRI gave full sectional information of the bone on both occasions without using ionizing radiation. The quality of the images was good, and should be considered as an alternative to the accepted gold standard of computed tomography (CT), which exposes the patient to a high dose of radiation.

[The reconstruction of posttraumatic defects of the orbit using dermal xenografts]. / Vosstanovlenie posttravmaticheskikh defektov glaznitsy s pomoshch'iu kozhnykh ksenotransplantatov.

The authors used in 75 cases dermal xenotransplant for reconstruction of posttraumatic defects of the orbit. 2 cases of complications due to neuromuscular damages and suppuration of the wound were observed.