Characteristics of a donor population in western Venezuela

To determine the characteristics of blood donors in western Venezuela, we collected data from 1983 to 1985 on 31,320 volunteer donors at the Blood Bank of the State of Zulia in Maracaibo. Fifty-nine percent of the donors were blood group O, 30 percent were group A, 9 percent were group B, and 2 percent were group AB. Most of the donors (93%) were Rh positive. One percent of donors had positive reactions to hepatitis B surface antigen, 3.15 percent for syphilis, 1.43 percent for antibodies to Trypanosoma cruzi, and 0.32 percent to human immunodeficiency virus antibodies. About one-half of the donors were between 18 and 30 years old, and only 10 percent were women. To determine if iron deficiency anemia was a cause for the small size of the female donor pool, we measured serum ferritin in 50 first-time female donors. Ten of these (20%) had serum ferritin values below normal, and the distribution of serum ferritin levels of all 50 was very similar to that reported for frequent donors in Europe and the United States, with a clustering of ferritin values between 10 and 70 ng per ml. The data indicate that blood donors in western Venezuela are markedly different from those in the United States and that iron supplementation may be indicated for female Venezuelan donors.     

新鲜冰冻血浆引发花生过敏被动转移

已知输注新鲜冰冻血浆(FFP)引起具临床意义的被动坚果过敏尚未见报道.本文报道一例无过敏史受者输注采集于花生过敏献血者的去白FFP引起被动花生过敏.     

Estimation of Vmax in auxotonic systoles from the rate of relative increase of isovolumic pressure: (dP/dt)kP

High speed oscilloscopic recordings (4000 mm/sec) of left ventricular pressure (micromanometer) and its first derivative were used to calculate contractile element velocity (Vce) during the isovolumic period of auxotonic beats in anesthetized dogs. At 0.5-2.0 msec intervals of isovolumic systole, Vce was derived as (dP/dt)/kP, where k = 24 cm(-1). Plots of Vce and P yielded inverse curves from peak Vce to aortic valve opening pressure which averaged 27 msec in controls, and 11 msec during norepinephrine administration. Extrapolated Vmax, in muscle lengths/second, averaged 3.6 (controls), 3.6 (volume load), and 6.6 (norepinephrine). In each experimental state, Vmax was also determined from force-velocity relations of isovolumic beats (abrupt aortic occlusion) analyzed at 10 msec intervals from conventional pressure recordings. Vmax by both methods correlated well (r = 0.88). While good correlations were also noted between Vmax and maximum dP/dt, (max dP/dt)/integrated isovolumic pressure, (max dP/dt)/peak isovolumic pressure, and (max dP/dt)/kP, only the last two of these successfully distinguished changes between volume load and inotropic stimulation. Thus, assuming an unchanged series elasticity, the contractile state of the auxotonic ventricle may be determined utilizing a single high-fidelity catheter system and high speed recordings of isovolumic pressure.     

The effect of sterilization on transforming growth factor beta isolated from demineralized human bone

Growth factors have been identified as the primary cause of osteoinduction in bone healing. Transforming growth factor beta (TGF- beta) has been shown to promote bone formation and is present in bone in high quantities. The aims of the present study were to isolate TGF- beta from human bone, demonstrate its biologic activity, and analyze the effects of conventional sterilization techniques on activity. Bone, obtained from femoral heads of five patients (mean age, 70 years) was ground, demineralized, and freeze-dried, and samples from each patient were divided into three groups: no treatment, sterilization with 1.60 to 1.94 Mrad of 60Co irradiation, and sterilization with ethylene oxide (ETO). Carrier-free recombinant TGF-beta control was also treated and was totally inactivated by ETO but not by irradiation (p < 0.01). TGF- beta activity in demineralized bone was not significantly diminished (p > 0.1) by either sterilization procedure, and substantial amounts of active TGF-beta were recovered in all bone samples: 1.04 +/− 0.77 ng per mg of protein in irradiated samples, 0.67 +/− 0.26 ng per mg in ETO- treated samples, and 1.04 +/− 0.33 in untreated samples, respectively (mean +/− SD). Although a recent report demonstrated that the osteoinductive activity of bone morphogenetic protein in bone powder is diminished considerably by ETO and by 2.5 Mrad of irradiation sterilization of bone powder, these data demonstrate that TGF-beta activity, with its osteoinductive properties, was not destroyed in more coarsely ground, demineralized bone by ETO or by lower doses of irradiation. These findings support the use of human bone allografts in clinical instances involving impaired bone formation.