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1. Simultaneous platelet and fibrinogen survival studies were carried out on a group of seven normal persons and eleven diabetic patients. 2. Survival time was calculated: (a) by measuring the interval between 50% of the maximum radioactivity in the anabolic phase and 50% of the maximum radioactivity in the catabolic phase, and (b) by fitting an exponential function to the decay phase of the curve. 3. With the first method, the normal group had a mean plaetelet survival which did not differ significantly from that in the diabetic group. With the second method, however, the platelet half-life in the diabetic patients was significantly shorter than in the normal subjects. 4. Fibrinogen survival was significantly shorter in the diabetic group with either method. 5. It is concluded that there is an increased utilization of platelets and fibrinogen in diabetic subjects.

The enteric adenovirus type 40 strain Dugan (Ad40) cannot be passaged in HeLa cells, but will grow in 293 cells, which express Ad5 E1 functions. To determine the reason for this limited host range, KB cell lines expressing Ad2 E1A, E1B, or E1A + E1B (L. E. Babiss, C. S. H. Young, P. B. Fisher, and H. S. Ginsberg, 1983, J. Virol. 46, 454-465) have been tested for their ability to support Ad40 replication. Only cell lines which supply E1B functions, but not those expressing E1A alone, are permissive for Ad40, suggesting that Ad40 may require some function supplied by E1B or induced in E1B-containing cells. In coinfection assays Ad40 complements Ad5 dl312 (delta E1A) but not Ad5 dl313 (delta E1B) and is itself complemented by dl312 but not by dl313. Mutants of Ad2 and Ad12 with lesions in E1B 55K or 19K protein have been used to further delineate the requirements for Ad40 growth in HeLa cells. For mutants lacking 55K function there is minimal complementation in either direction, whereas those lacking only the 19K product are able to complement Ad40.

The effects of acute fat feeding on fibrinolytic activity, platelet aggregation, and stypven time in six elderly Africans are presented. These indicate that there is no alteration in the pattern of response seen in Africans with advancing age.

Clonidine, in a daily dosage of 0.15-4.8 mg., effectively lowered systolic and diastolic pressures in 26 out of 28 impatients with moderate to severe hypertension, including five with primary renal disease. The action of the drug did not depend on posture and was not associated with reduction in renal function. Side-effects were not severe, but mental changes occurred in four patients.Clonidine is a useful alternative to currently available antihypertensive drugs, but further evaluation of its longterm efficacy is required.

The effects of the venoms of Naja melanoleuca, Naja nigricollis, and Ophiophagus hannah on blood coagulation, platelet aggregation, and fibrinolysis were studied in vitro. All three venoms were shown to be anticoagulant. This action appeared to be due to an effect on both the extrinsic and blood thromboplastin mechanisms. Platelet aggregation in Chandler's tubes and adenosine diphosphate reactivity were inhibited by the three venoms, although in the case of Ophiophagus hannah venom they were inhibited only with intermediate concentrations. The three venoms possessed proteolytic properties, but when incorporated into purified caseinolytic systems and euglobulin clot lysis systems inhibition of plasmin activity was observed.

The effects of acute fat feeding on fibrinolytic activity, platelet aggregation, and Stypven time in 10 Africans and 10 Asians are presented and compared with the results previously obtained in 10 Europeans. These indicated that the inhibition of fibrinolytic activity seen in Europeans does not occur in either Africans or Asians although the Stypven time was shortened in all three groups. Platelet aggregation, as measured by the Chandler's tube technique, was inhibited by fat feeding in Europeans but was unchanged in Africans and Asians. The results also indicate that the fibrinolytic activity of Africans and Asians is greater than that of Europeans.

The venom of the rhinoceros horned viper (Bitis nasicornis) has been studied in vitro and has been shown to be anticoagulant. This action appeared to be due to an effect on both the extrinsic and intrinsic blood thromboplastin mechanisms. The venom was also proteolytic and in purified caseinolytic systems activated plasminogen, enhanced the activation of plasminogen by streptokinase, and potentiated the action of plasmin. In the euglobulin clot lysis system high concentrations of venom produced inhibition. The crude venom increased platelet adhesiveness but in high concentrations delayed the snowstorm effect in the Chandler's tube system and inhibited platelet adenosine diphosphate reactivity. Passage through carboxymethylcellulose yielded six fractions. One possessed anticoagulant activity, inhibited plasmin, and increased the optical density of platelet-rich plasma. The other five fractions shortened the plasma recalcification time but had no effect on plasmin activity. Four fractions aggregated platelets and enhanced platelet adenosine diphosphate reactivity.