Po66, a monoclonal antibody (MAb) directed against lung squamous cell carcinoma, has been shown, when injected intravenously, to be retained for a long time in tumors. This property encouraged trials to use Po66 as an agent of metabolic radiotherapy. The suitability of multicellular spheroids to reproduce the in vivo conditions of irradiation of tumors by Po66 was investigated in the present work. Spheroids were formed from the lung carcinoma cell line SK-MES-1. They resembled morphologically small carcinoma nodules with desmosome-like intercellular junctions at the periphery and a central necrotic core. The cells expressing the antigen recognized by Po66 had a heterogeneous distribution and were predominant in the outer layers of the cell aggregates. Spheroids were exposed to radiolabelled Po66. The MAb diffused slowly and reached a maximal incorporation after 4-12 hours incubation. A control unrelated antibody did not penetrate appreciably. Autohistoradiographic experiments suggested that the antibody accumulated in most cells expressing the antigen. The rate of MAb release from the spheroids was very low (T 1/2 = 163 h). Taken together, the data indicate that spheroids might be a relevant model to investigate the parameters controlling Po66-mediated immunoradiotherapy.

Animals↗

PubMedDate not supplied

Direct fast track admission to a coronary care unit.

An audit of thrombolytic therapy for acute myocardial infarction (AMI) in 1992-93 showed that door to needle time had a median delay of 100 min. After discussion, we devised a new 'fast track' procedure. General practitioners (GPs) were given minimum criteria for diagnosing probable AMI and advised how to admit patients directly to the coronary care unit (CCU) after discussion with a senior CCU nurse. The hospital admitted 180 patients with MI between 1 July 1993 and 30 June 1994, 96 of whom received thrombolysis. Of the 11 admitted by the fast track procedure, eight received thrombolysis (median delay, 13.5 min; range, 5-30 min; p < 0.05 when compared with non-fast track patients). Four other patients were fast tracked to the CCU from other medical wards (time to thrombolysis, 6-12 min). In the following year to 30 June 1995 there were 158 admissions with MI, of whom 85 (54%) received thrombolysis. Four patients were admitted by the fast track procedure. Although the fast track procedure shortened the time to thrombolysis, the service was underused. A postal audit of local practices showed that 18% of GPs were still unaware of the service, in spite of newsletters, postgraduate meetings and direct contact. Most GPs (90%) said they would use the service in the future, but 25% stated later that they would not use it. Twenty per cent of non-fast track AMI patients were admitted by deputising doctors.

Adult↗

PubMedDate not supplied

Controller for an axial-flow blood pump.

An axial-flow ventricular assist device (VAD) under development at the authors' facility is intended for use as a long-term implantable device. At high speeds axial-flow VADs can collapse the native ventricle and damage the heart muscle, lung tissue, and blood. A prototype algorithm was developed to maintain physiologic perfusion to the vital organs while preventing ventricular collapse, through analysis of the electrical current waveform of the motor. The premise of the control algorithm is that the hemodynamics of the patient are reflected in the shape of this waveform. This approach is intended to eliminate the need for invasive sensors, thus effectively using the pump itself as a transducer. The control algorithm regulates the speed of the pump by comparing the motor-current waveform with reference waveforms using a matched filter. The matched filter was evaluated by its classification and differentiation performance. Thus far, the authors have been able to classify the waveforms into one of the four physiologic regions (below, within, or above the optimal range, and ventricular suction) with over 90% reliability. Ongoing work is directed toward improving the detection of ventricular suction, as this condition must be strictly avoided.

Algorithms↗

PubMedDate not supplied

Clinical supervision: making it happen.

When owned and governed by those who implement it, clinical supervision can become a living, breathing part of professional working life, and not just another ritual. A multidisciplinary team from Southampton explains.

Aged↗