A model of superficial bladder cancer using fluorescent tumour cells in an organ-culture system.

OBJECTIVE: To develop a reproducible in vitro simulation of superficial bladder cancer for testing cytotoxic agents at clinically relevant concentrations. MATERIALS AND METHODS: Square explants (5 mm) of rat bladder were cultured in Petri dishes in minimal volumes of Waymouth's MB 752/1 medium supplemented with 10% fetal calf serum, antibiotics and glutamine. Parental and resistant MGH-U1 urothelial cancer cells were transfected with a green fluorescent protein (GFP) vector. Transfectants were purified by flow cytometry. Cells were seeded onto the prepared organ cultures and images obtained using confocal microscopy. The tumour colonies were confirmed using scanning electron microscopy. Conventional intravesical cytotoxic agents including epirubicin, mitomycin-C and estramustine were tested in the system. RESULTS: Colonies of GFP-MGH-U1 cells became established on the explants and were identified by confocal microscopy; the development of the colonies was then followed over several days. Staining the explant for viability allowed imaging of normal urothelium on the explant surface or surrounding skirt of urothelial cells. The conventional cytotoxic agents epirubicin, mitomycin C and estramustine showed the expected differential responses to parental and resistant cell types. The colonies were able to survive high concentrations of the drug, equivalent to those in clinical use. The colonies were imaged serially over a period of several days. CONCLUSION: This system provides a more realistic model for testing cytotoxic agents for use in intravesical therapy, by allowing clinically relevant concentrations of drugs to be tested. The differential properties of the parental and resistant cells are maintained. The model also enables the same tumour colony to be imaged over several days in culture. The model may also be adapted for use in testing the effects of drugs on normal urothelium and the study of the effects of growth factors.

Maxillofacial trauma at RAF War Hospital, Wroughton.

The following article is a historic look at maxillofacial trauma at the Royal Air Force War Hospital at Wroughton from D-Day to VE Day. The article describes the pattern of injury and the management of personnel injured on the Continent and evacuated to Wroughton by air ambulance.

A noninvasive method for monitoring cerebral perfusion during cardiopulmonary resuscitation.

PURPOSE: This study evaluates the use of transcranial Doppler (TCD) ultrasound in assessing the changes experienced by the cerebral circulation during cardiopulmonary resuscitation (CPR) and compares it with measurements of internal carotid artery (ICA) flow rates (ultrasonic flow-meter measurements) and cerebral blood flow (CBF) (radioactive-microsphere measurements) in a porcine cardiac arrest model undergoing closed chest CPR. METHODS: Sixteen piglets were anesthetized and subjected to TCD monitoring, ICA flow-rate measurements, and CBF measurements during CPR following induction of ventricular fibrillation. A total of 14 comparisons between TCD and CBF measurements, and 36 comparisons between TCD and ICA flow measurements were performed. Correlations were determined using Pearson's method, and the validity of the correlation was determined using Bonferoni's adjusted probabilities. RESULTS: The correlation between mean cerebral blood flow velocity and mean total ICA flow rate was 0.67 (P < .01). The correlation between peak systolic blood flow velocity and CBF was 0.76 (P = .02). CONCLUSIONS: TCD can provide on-line information about cerebral perfusion during CPR.

Transcranial Doppler ultrasonographic assessment of intermittent light stimulation at different frequencies.

Seven normal adult volunteers underwent intermittent photic stimulation at frequencies of 5-60 Hz while their posterior cerebral arteries were monitored using transcranial Doppler ultrasound. Baseline measurements were obtained under conditions of total darkness, and sampling was also done during continuous illumination. Overall variation in mean flow velocity between complete darkness and continuous illumination was 9.8%, but the maximal change (expressed as percentage deviation from baseline) occurred consistently when stimulation was undertaken at frequencies of 10 (21%) and 20 (19%) Hz (p = 0.05). Frequencies higher than 20 Hz resulted in mean flow velocity variations that were not significantly different from that found during continuous illumination. The optimal frequency of intermittent visual stimulation required to induce measurable changes in posterior cerebral artery Doppler characteristics appears to be in the range 10-20 Hz.

Transcranial Doppler determination of cerebral perfusion in patients undergoing CPR: methodology and preliminary findings.

STUDY OBJECTIVES: To correlate cerebral arterial blood velocity measurements as determined by transcranial Doppler ultrasound with various resuscitation maneuvers performed in an uncontrolled manner in a series of cardiac arrest patients undergoing standard resuscitation. TYPE OF PARTICIPANTS: Any patient undergoing resuscitation for a nontraumatic cardiac arrest was eligible for the study. INTERVENTIONS: Resuscitation was carried out while flow velocities were monitored in various intracranial arteries by transcranial Doppler ultrasound. Vessel identification was based on the angle and depth of insonation. MEASUREMENTS AND MAIN RESULTS: The internal carotid artery was located more consistently than either middle cerebral or ophthalmic arteries and provided superior waveforms for analysis. Alterations in flow velocity were noted and correlated to various therapeutic interventions. Flow velocities were 70% of normal during the early phase of resuscitation but deteriorated over time until there was no evidence of net forward flow. Even early in CPR, flow was demonstrated only during systole. CONCLUSION: Transcranial Doppler ultrasound appears to be a potentially promising means of determining cerebral flow in patients undergoing CPR.