Drug Prevention and the Police in the UK: A review of recent research studies

There is increasing concern among British police forces about their role in drug prevention in schools. This paper reviews drug prevention research in the US, Australia and the UK in order to compare and contrast prevention policy and practice within schools internationally and to consider which approach would be most effective and appropriate for the UK. The paper focuses on prevention rather than education because of the current emphasis on prevention in British policy. The paper raises questions that need careful consideration before drug prevention policies are introduced in the UK. First, there is a need to determine whether schools should be concerned predominantly with programmes of drug prevention or harm minimisation, as it is in the disciission of these concepts that the reasons (and aims) for any programme will be articulated. It is then necessay to identify the most effective programme content and most appropriate providers, and to gather information regarding target audiences. The early indications from research findings are that general interactive skills-based programmes are more useful than the more directive and didactic police-led initiatives; that these should be integrated within the established school curriculum and that trained teachers may therefore be the most appropriate professionals to take the lead. However there is international consensus concerning the importance of a multi-disciplinary approach, emphasising the partnership between teachers, police and parents and stressing the importance of community involvement in the development of any school-based programme. The limitations of present research are identified; there are constraints on evaliratiori and there are few of the longitudinal studies necessary for measuring change over time. It has been difficult to distinguish between the effects of police input and the police programmes themselves. Although evaluative studies identify increases in knowledge, they have riot yet demonstrated any significant immediate, or long term, changes in either attitudes or behaviour.     

Increased prothrombin activation in protein S-deficient plasma under flow conditions on endothelial cell matrix: an independent anticoagulant function of protein S in plasma

Protein S is a vitamin K-dependent nonenzymatic coagulation factor involved in the regulation of activated protein C (aPC). In this study, we report an aPC-independent anticoagulant function of protein S in plasma under flow conditions. Plasma, anticoagulated with low-molecular- weight heparin allowing tissue factor-dependent prothrombin activation, was perfused at a wall shear rate of 100 s-1 over tissue factor containing matrices of stimulated endothelial cells placed in a perfusion chamber. Fractions were collected in time at the outlet and prothrombin activation was determined by measuring the activation fragment F1+2 of prothrombin. In normal plasma, a time-dependent prothrombin activation was detected by the generation of fragment1+2. Prothrombin activation had ceased after 12 minutes perfusion, independent of the amount of tissue factor present in the matrix. Depletion of protein S from plasma or inhibition of protein S in plasma by monoclonal antibodies induced a 5- to 25-fold increase of prothrombin activation on the procoagulant endothelial cell matrix. A prolonged prothrombin activation was detected in protein S-depleted plasma up to 20 minutes after onset of the thrombin generation. The increased prothrombin activation in protein S-depleted plasma could not be explained by the absence of the cofactor function of protein S for aPC because depletion of protein C from plasma did not result in increased prothrombin activation. These data provide further evidence for a strong anticoagulant function of protein S in plasma independent from activated protein C.     

Comparative audit of blood transfusion during war and peace in Sarajevo.

A comparative study was made between 146 patients receiving blood transfusion at the State Hospital, Sarajevo, in a 3-month period of peace (group 1) and 250 patients receiving transfusions in a 3-month period of war (group 2). In group 1, trauma accounted for only 7% of transfusions while it accounted for 99% in group 2. The threshold for transfusion was increased in war and the mean pretransfusion haematocrit in group 2 was 21%, compared with 27% in group 1 (P < 0.001). Less blood was also transfused per patient in war with a mean transfusion volume of 1.1 units in group 2 compared with 2.6 units in group 1 (P < 0.001). The reasons and justification for such a conservative transfusion practice in a besieged city are discussed.     

Brachiocephalic artery dilation by percutaneous transluminal angioplasty

Percutaneous transluminal angioplasty (PTA) was used to dilate stenotic lesions in 38 brachiocephalic arteries in 36 patient. Complete evaluation of the central nervous system blood supply is a prerequisite for the brachiocephalic PTA when cerebral symptoms are present. The femoral artery is the best vascular entry site; use of digital subtraction angiography equipment for arterial mapping is helpful. Balloon diameter should be the same as or slightly wider than the diameter of the normal artery adjacent to the stenotic segment. Spasm was successfully treated with intraarterial injection of nitroglycerin. The only drug therapy consistently used with PTA was aspirin. Complete dilation of the stenosis is the best prevention of thrombotic or embolic complications. In properly selected cases, proximal subclavian artery stenoses can be safely dilated, and the balloon can eventually be placed across the origin of the vertebral artery. Because of potential complications associated with brachiocephalic PTA, indications must be well established, and interventions should not be performed on marginal or asymptomatic stenoses.     

Choroidal melanomas: correlation of NMR spectroscopy and MR imaging

Six freshly enucleated, unfixed human eyes with choroidal melanomas were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system. Immediately thereafter the eyes were sectioned, and tumor samples were removed for study on a variable-field (0.19-1.4 T) nuclear MR spectroscopy unit. Shorter T1 and T2 relaxation times were observed in those tumors with the greater concentrations of melanin. This is believed to result from the paramagnetic effect of radicals known to exist in melanin. High magnetic field MR imaging can enable one to distinguish between pigmented melanomas; proteinaceous effusions; fresh and subacute hematomas; and nonmelanotic tumors, including amelanotic melanomas; but may not enable melanotic melanoma to be distinguished from fat or amelanotic melanoma from other nonpigmented tumors.