AUTOTRANSFUSION: QUALITY OF BLOOD PREPARED WITH A RED CELL PROCESSING DEVICE

The quality of blood salvaged at operation and prepared withthe Dideco Autotrans BT 795 autotransfusion device was comparedwith that of donor blood in 41 patients having cardiac surgeryinvolving cardiopulmonary bypass. Saved blood had a higher haemoglobinconcentration (17.3 v. 13.1 g dl^–1; P < 0.001), a higher2, 3-diphosphoglycerate concentration (5.3 v. 1.1 mmol litre^–1;P < 0.00001), higher white cell count (17.1 x 10⁹ litre^–1v. 4.1; P < 0.00001), higher pH (7.5 v. 6.6; P < 0.00001)and a more physiological potassium concentration (5.4 v. 8.8mmol litre^–1; P < 0.00001) than donor blood. Savedblood platelet count was 34.5 x 10⁹ litre^–1 compared with146.24 x 10⁹ litre^–1 (P < 0.00001) and its heparinconcentration was 0.64 u. ml^–1. We conclude that thisautotransfusor is a useful aid to blood conservation, producinggood quality red cells with relatively normal pH and potassiumvalues. However, modification of the centrifugation and washingis required to lessen the high white cell count and heparinconcentrations found in the saved blood.     

Skin mast cells in polycythaemia vera relationship to the pathogenesis and treatment of pruritus

We have measured skin mast cell numbers, circulating basophils and whole blood histamine in 13 patients with polycythaemia vera. Itching was present in nine cases and correlated well with the numbers of skin mast cells but not with circulating basophils or whole blood histamine. Immediate relief of pruritus was achieved with aspirin, and myelosuppressive therapy was useful for long-term control of symptoms. Neither histamine (H1 or H2) antagonists nor iron replacement therapy were effective forms of treatment. The findings suggest that mast cell prostaglandins are an important factor in the pathogenesis of pruritus and that local vascular responses may trigger mast cell degranulation.     

The removal of amateur tattoos by salabrasion

Due to the recent upsurge in self-inflicted tattoos in teenagers it was decided to employ for their removal the method of salabrasion, i.e. abrasion with table salt. This technique was recently used by Manchester (1973, 1974) for the removal of commercial tattoos. Fourteen patients with twenty-eight tattoo or only tiny flecks of pigment remaining visible; eleven showed a fair response, i.e. the tatoo, although much lighter in colour, was still legible but the patient was satisfied with the result; three showed a poor response, i.e. the tattoo appeared as if untreated; four (two patients) defaulted. In general, as could be expected, the darker the tattoo the more difficult was its removal and those on fingers were particularly resistant.     

The lines of Blaschko: a review and reconsideration

Blaschko's lines are the pattern assumed by many different naevoid and acquired skin diseases on the human skin and mucosae. They were described and drawn by Blaschko 75 years ago. These lines are to be distinguished from other linear patterns such as Voight's lines, Langer's lines, and the lines of innervation of the spinal nerves. They do not follow any known nervous, vascular or l5rmphatic structures in the skin. The epidermis and its appendageal structures, the melanocytes, the vascular system, and the fatty hypoderm, all, separately or in combination, may be involved in the morpho-logical manifestations which follow Blaschko's lines. Many of the naevoid skin conditions are lifelong (e.g. linear sebaceous naevus, unilateral naevoid telangiectasia); many of the acquired skin diseases (e.g. lichen striatus, linear psoriasis) are of relatively short duration (e.g. 1–2 years). The cause of the distribution pattern is unknown. It is possibly a form of human‘mosaicism’ where certain specific cells or groups of cells react differently from other cells due to chromosomal abnormalities. The embryological explanation of Blaschko's lines is not at all clear. Other markers in addition to the skin findings are needed to determine the time and the nature of the change responsible for these lines. The main purpose of this article is to introduce the concept of Blaschko's lines into the medical, paramedical, and general biological fields of science. In this way, it is hoped that some inter-reaction can occur between those who regularly see Blaschko's lines and those who regularly see and study other chromosomal and embryological abnormalities.     

Enhancement of fibrinolysis by inhibiting enzymatic cleavage of precursor α2‐antiplasmin

Summary. Background and objective: Resistance of thrombi to plasmin digestion depends primarily on the amount of α₂‐antiplasmin (α₂AP) incorporated within fibrin. Circulating prolyl‐specific serine proteinase, antiplasmin‐cleaving enzyme (APCE), a homologue of fibroblast activation protein (FAP), cleaves precursor Met‐α₂AP between ‐Pro12‐Asn13‐ to yield Asn‐α₂AP, which is crosslinked to fibrin approximately 13× more rapidly than Met‐α₂AP and confers resistance to plasmin. We reasoned that an APCE inhibitor might decrease conversion of Met‐α₂AP to Asn‐α₂AP and thereby enhance endogenous fibrinolysis. Methods and results: We designed and synthesized several APCE inhibitors and assessed each vs. plasma dipeptidyl peptidase IV (DPPIV) and prolyl oligopeptidase (POP), which have amino acid sequence similarity with APCE. Acetyl‐Arg‐(8‐amino‐3,6‐dioxaoctanoic acid)‐d ‐Ala‐l ‐boroPro selectively inhibited APCE vs. DPPIV, with an apparent K_i of 5.7 nm vs. 6.1 μm , indicating that an approximately 1000‐fold greater inhibitor concentration is required for DPPIV than for APCE. An apparent K_i of 7.4 nm was found for POP inhibition, which is similar to 5.7 nm for APCE; however, the potential problem of overlapping FAP/APCE and POP inhibition was negated by our finding that normal human plasma lacks POP activity. The inhibitor construct caused a dose‐dependent decrease of APCE‐mediated Met‐α₂AP cleavage, which ultimately shortened plasminogen activator‐induced plasma clot lysis times. Incubation of the inhibitor with human plasma for 22 h did not lessen its APCE inhibitory activity, with its IC₅₀ value in plasma remaining comparable to that in phosphate buffer. Conclusion: These data establish that inhibition of APCE might represent a therapeutic approach for enhancing thrombolytic activity.     

THE TAKING OF MICROPHOTOGRAPHS WITH THE AID OF A SIMPLE AND INEXPENSIVE . APPARATUS*

A Metron Reflcx Drawing oucfit ohtaincd from Messrs. C. Baker, 224 ''High Holborn, London, has been in use in the Laboratory of the Malaria Bureau during several ycars, for micro. drawing and for class demonstrations.