In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Suppression of the vitro humoral immune response of mouse splenocytes by benzo(a)pyrene metabolites and inhibition of benzo(a)pyrene-induced immunosuppression by alpha-naphthoflavone

Several investigators have demonstrated that the humoral immune response of mice and splenocyte cultures was suppressed with benzo(a)pyrene [B(a)P] exposure. The mechanism of the B(a)P immunosuppression, however, has not been established. Since reactive metabolites of B(a)P, rather than the parent compound, have been shown to mediate the carcinogenic effects of B(a)P, it was hypothesized that the immunosuppression produced by B(a)P may also be mediated by its reactive metabolites. The objective of this investigation was to examine the role of B(a)P metabolism in the B(a)P-induced suppression of the in vitro humoral immune response. This was addressed by first determining if various B(a)P metabolites are capable of inhibiting the generation of antibody-forming cells (AFC) of splenocyte cultures. Addition of B(a)P or B(a)P-7,8-diol (2 X 10(-5) M) to splenocyte cultures produced a similar dose-dependent suppression of the in vitro T-dependent AFC response to sheep red blood cells. In contrast, decreases in the AFC response and cell viability of cultures exposed to the 4,5-diol or 9,10-diol were only observed at 2 X 10(-5) M. Exposure of cultures to 3-hydroxy-B(a)P resulted in a significant decrease in the AFC response at 2 X 10(-6) and 2 X 10(-5) M. Slight decreases in the AFC response were observed with the addition of B(a)P-4,5-epoxide or B(a)P-6,12-dione at 2 X 10(-6) M, whereas a dramatic decrease in the AFC response, as well as a 45% decrease in cell viability, was obtained at 2 X 10(-5) M. The second objective was to examine the effects of the cytochrome P-450 inhibitor, alpha-naphthoflavone (ANF), on the B(a)P- and B(a)P-7,8-diol-induced suppression of the in vitro AFC response. Exposure of splenocyte cultures to 2 X 10(-5) M ANF did not affect the AFC response. Coincubation of splenocytes with ANF was observed to attenuate the suppressive effects of B(a)P and B(a)P-7,8-diol. This concentration of ANF was observed to inhibit the metabolism of [3H]B(a)P by splenocyte cultures to water soluble metabolites. Moreover, B(a)P metabolism by splenic microsomal preparations of untreated mice was inhibited by ANF. These findings suggest that the B(a)P-induced suppression of the in vitro AFC response is mediated by B(a)P metabolites generated by cytochrome P-450 present within splenocytes.     

Prognostic significance of oestrogen and progestogen receptor activities in breast cancer

The prognostic significance of the tumour activities of 2 steroid receptors, those for oestrogen (ER) and for progestogen (PgR), has been studied in 372 patients with breast cancer, in whom follow-up was available for 2-6 years (median 41 months). Of 252 patients with operable disease, 75.8 per cent had ER-positive tumours and 46.4 per cent had PgR-positive tumours, though a small additional fraction (6.3 per cent) had an equivocal PgR assay result. For the 236 patients with unequivocal receptor status, the relationships between disease-free interval or overall survival and receptor activity and other factors were evaluated by univariate and multivariate analyses. The latter revealed that only tumour size, node status, menstrual status and ER status related significantly to both disease-free interval and survival, though adjuvant therapy also related to disease-free interval, and tumour grade related to survival. It is concluded that measurements of PgR activity do not add to the prognostic significance of ER status.     

Cutaneous allergy to mustard in a salad maker

A case of allergic contact dermatitis to mustard (Brassica nigra) in a salad maker is reported. The sources of skin contact included a commercial salad cream, a vinegrette, and various members of the mustard family, Cruciferae. The Cruciferae family includes many salad vegetables and condiments which contain allergenic isothiocyanates. The extent of skin contact among salad makers and other food handlers may be significant, and sensitization to isothiocyanates from this large family of vegetables may be an important cause of food contact allergy in these individuals.     

Tensor fascia lata myocutaneous flap in lower abdominal wall reconstruction

The tensor fascia lata myocutaneous flap provides a reliable autogenous building block for anatomical lower abdominal wall reconstruction. Preservation of innervation allows maintenance of voluntary motor control and protective sensation. The excellent blood supply of this flap is particularly helpful in reconstructing previously irradiated areas. A one-stage repair is possible, leaving minimal secondary defect. We describe 4 patients illustrating the uses and versatilty of this flap. Anatomy, operative procedures, and indications for delay are also discussed.     

Influence of a calcium dependent protease inhibitor on platelet activation and secretion

Continuous proteolysis resulting in consumption of major cytoskeletal proteins may be essential for platelet activation and aggregation. In this study we evaluated the effect of a known protease inhibitor, Leupeptin, on agonist induced platelet aggregation and secretion. Platelets exposed to 10 ugs/ml of Leupeptin did not aggregate in response to the action of thrombin (0.2u/ml). However, a concentration of Leupeptin as high as 250 ugs/ml did not prevent arachidonate induced aggregation and secretion. Leupeptin (100 ugs/ml) effectively blocked thrombin (0.2 u/ml) induced elevation of cytosolic calcium, but did not affect arachidonate induced elevation of platelet intracellular calcium levels. At a concentration of 100 ug/ml, Leupeptin effectively blocked thrombin (0.5u/ml) induced clot formation of platelet poor plasma, suggesting that it can exert its effect on thrombin by preventing fibrinogen degradation. Effective K_i for the competitive inhibition of thrombin induced hydrolysis of a chromogenic substrate, S2238, by Leupeptin was 2.4 uM. Leupeptin inhibition of platelet function was reversible by washing platelets free of the polypeptide. Results of our study demonstrate that Leupeptin inhibits thrombin induced platelet activation, probably by interfering with its proteolytic activity on the platelet surface membrane. However, inhibition of platelet surface membrane associated proteases did not prevent activation of platelets by other agonists.     

Cardiac arrhythmogenic action of benzo(a)pyrene in the rabbit

Rabbits treated with benzo(a)pyrene developed cardiac arrhythmias when exposed by inhalation to 8100 ppm trichloroethylene or 15000 ppm halothane to a greater extent and at lower doses of epinephrine challenge than did controls. Benzo(a)pyrene and 3-methylcholanthrene both increased the metabolism of trichloroethylene, but 3-methylcholanthrene did not increase its cardiotoxic effect. The basis of the arrythmogenic action of benzo(a)pyrene appears to be unrelated to its ability to induce xenobiotic metabolism.