[Determination of various fractions of complement (Cl, C3c, C3a, C4) in a population of healthy neonates]. / Determinazione di diverse frazioni del complemento (C1, C3c, C3a.,C4) su di una popolazione neonatale sana.

The authors have studied plasma levels of various complement fractions (C1,C3c,C3att.,C4) in 127 newborns. Referring to gestation period the studied subjects were divided as follows: 25 newborns (less than 37 weeks), 78 newborns (37-41 weeks), 21 newborns (more then 41 weeks). The mean values of various fractions results higher in the newborns with higher gestation period. Considering the gestational ages, the mean values obtained for each complement fraction are not different from those considered "normals". The range of single value turned out very wide. This fact should lead to prudence in the diagnostic valuation.

Biological and binding activities of equine pituitary gonadotrophins and pregnant mare serum gonadotrophin.

The biological and binding activities of pregnant mare serum gonadotrophin (PMSG) were compared with those of highly purified FSH and LH from the pituitary gland of the same species. Pregnant mare serum gonadotrophin showed activity in bioassays considered to be specific for both FSH (e.g. the Steelman-Pohley ovarian augmentation test and cyclic AMP production by rat seminiferous tubules) and LH(androgen production by rat Leydig cells), as well as activity in a variety of radioreceptor assay systems previously considered to be specific for one of the two types of gonadotrophin. The potency of PMSG was high compared with that of purified ovine FSH or LH standards in all assays but PMSG was considerably less active than equine FSH and LH in vitro. In radioreceptor assays employing rat, pig and horse tissues, the activity of PMSG was equivalent to only 1--5% of equine FSH in competing for FSH-binding sites and only 3--35% of equine LH in competing for LH-binding sites. Pregnant mare serum gonadotrophin was least active in homologous binding assays with horse testis and equine LH as radioligand. In the rat Leydig cell bioassay, the activity of PMSG was only 2.0% that of equine LH. Furthermore, in some assays equine LH was found to resemble PMSG in exhibiting a high degree of FSH-like activity that could not be accounted for by cross-contamination. The FSH immunoactivity of equine LH was less than 0.5% that of equine FSH, but equine LH was up to 63% as potent as equine FSH in competition for FSH-binding sites and it was 20% as active in the Steelman-Pohley ovarian augmentation bioassay. Equine LH did not, however, show the expected activity in the cyclic AMP production bioassay. Thus, the FSH-binding sites and physiological receptors may not be identical. Overall, comparison of PMSG with pituitary gonadotrophins from homologous species shows that the apparent dual activity of PMSG may not be a unique feature of this pregnancy hormone since equine LH also exhibits some FSH activities. The chemical resemblance between PMSG and equine LH is noteworthy in this regard.

[Current status of simple radial immunodiffusion for determination of minimal quantities of IgA and IgM]. / Attualita' della immunodiffusione radiale semplice per la determinazione di minime quantita' di IgA e IgM.

IgA and IgM determination has been performed in the blood of the umbilical cord of 120 healthy newborn infants at different gestational ages. The utilization of the "Tripartigen Platelets" and "L.C. Partigen" has shown the extreme sensibility of the latter in determining minimum quantities of IgA and IgM.

Physiological actions of human follicle-stimulating hormone and its beta-subunit in reptiles.

The actions of human follicle-stimulating hormone (hFSH) and its beta-subunit were examined in several assays in reptiles, including effects on lizard testicular activity (growth and androgen production) in vivo, and stimulation of androgen production by snake testes and competition for binding of 125I-labeled hFSH in lizards and snakes in vitro. Binding was also examined with mammalian tissues. The hFSH was highly steroidogenic in the snake and lizard; otherwise results were similar to those observed in mammals. In all cases, the potency of the beta-subunit was only a few per cent of the intact hormone. The potency of hFSH in vivo compared with NIH-FSH ovine standards was several 100 times greater than in vitro. Results for stimulation of androgen production in vivo closely paralleled those for binding assays in both reptiles and mammals. In contrast to previous results for ovine FSH beta-subunit, human FSH beta-subunit has little if any FSH biological activity in reptiles.