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Biomedical subjects

G Ricco

Publications and source records attributed to G Ricco.

At least 37 records · Page 2Linked to original sources
PubMed1989

A follow-up on functional parameters of blood stored in ACD at +4 degrees C.

The main functional parameters of blood stored at +4 degrees C in ACD, according to the common transfusional practice, have been carefully followed in the course of 40 days. The expected depletion of DPG takes place within 10 days, but apparently, no increase of the Hb affinity towards oxygen is observed in this period (or later), because pH lowering acts in the opposite direction during the same time. However, the intrinsic increased affinity of Hb is promptly revealed if the "actual" pHs are corrected at the standard value of 7.4, and/or are extrapolated at this pH from Bohr effect.

2,3-Diphosphoglycerate↗
PubMed1985

The whole blood oxygen affinity in normal human newborns: II) P50, n value and related parameters.

The cord blood from 82 normal newborns (48 males and 34 females) has been extensively investigated, to check p50, cooperativity and related parameters. The most important results are the following: Neonatal p50 is slightly above 20 torr, in good agreement with the literature data, but this value refers to the p50 "CO-free" (T50); otherwise, the original p50 is slightly less than 22 torr, a value which is not indicative enough, because neonatal blood contains a consistent excess of Hb-CO. Either this CO-excess and the low p50 value seem to be mainly depending on the low binding capacity of Hb-F with DPG, even if further studies are still necessary at regard. The empirical factor correcting adult p50 to T50 is -0.27, a value which must be increased to -0.36 for neonatal blood. Multiple gas analyses of the samples indicate that oxygen transport is a very complicate equilibrium involving pH, CO2, bicarbonate balance and other factors. A complete statistical analysis of the data has been carried out and the main result indicates that oxygen assumption favours CO2 releasing and vice versa, a phenomenon already well known and globally called "Bohr effect".

Bicarbonates↗
PubMed1984

The cord blood oxygen affinity from normal human newborns: 1) A methodological approach.

A correct analysis of O2 affinity in neonatal whole blood puts some important, still unsolved problems of methodology, mainly based upon the fact that this kind of blood is a mixture of at least two major hemoglobins, i.e. 2/3 Hb-F and 1/3 Hb-A, having different affinities. Whereas adult blood mainly contains Hb-A. Within such a perspective, the Authors have checked if the empirical Davenport's nomogram, correcting the pO2s of adult blood to the same standard pH of 7.4, can also be used for neonatal blood. The answer is affirmative, and in addition the nomogram can also be replaced, with some advantage, by an only mathematical correction of the measured pO2s, in which pH differences from 7.4 (either positive or negative) are converted in proportional differences of pO2 and either added or subtracted to the values of these latter. Hb-CO level is undoubtedly higher in newborns than in non-smoker adults, but no factor for T50 calculation of neonatal blood has been till now identified. The Authors have determined a factor of -0.36, which can be obtained from the homologous (experimental) "adult" factor of -0.27, by multiplying this latter for 1.35.

Adult↗
PubMed1984

The three polymorphic chains of human Hb-F studied in normal Italian newborns.

Both the known polymorphisms of human Hb-F have been investigated here. Two similar groups of full-term newborns have been considered: pure F-globin has been studied by suitable fingerprinting techniques in the first group, while isoelectrofocusing techniques have been employed in the second. The results clearly indicate that G/A gamma polymorphism can be correctly determined with both the procedures, while the T/I gamma polymorphism cannot, because IEF is not sensitive enough towards low quantities of A gamma T chains. Moreover, in the first group of newborns, the A gamma T gene frequency (P) is 0.23, while the total G/A gamma ratio of both groups is about 7/3, the two data being in full agreement with those of the literature. Furthermore, additional reports show that the main functional parameters of the whole neonatal blood are not significantly different either in the presence or in the absence of A gamma T chains.

Alleles↗
PubMed1984

Functional properties of the whole blood in a carrier of Hb-Atlanta: beta 75 (E-19) Leu-Pro.

The Authors illustrate the main functional parameters of the whole blood in a heterozygous carrier of the unstable Hb-Atlanta. The most important results are represented by a right-shifted P50, by a lowered value of n and by an almost normal pH-depending Bohr effect. It is very likely that the first report depends on the relative Hb-A deficiency, whereas the second one could be due to the presence of the unstable Hb. Moreover, the linkage between this latter and DPG would be present.

Blood Physiological Phenomena↗
PubMed1984

The oxygen affinity of normal human whole blood measured by double tonometry. I. P50 and n factor.

The Authors refer that the oxygen affinity, determined by double tonometry, in normal adult whole blood, is mainly expressed by a P50 of 26.13 +/- 4.31% and by an n factor of 2.63 +/- 6.63%. These results are in good agreement with those reported in the literature, but here are some doubts that pO2 and SO2 alone, i.e. the data drawn from all the tonometric procedures, can give a full idea of the affinity. In fact, this one is a complicate process, modulated by a number of allosteric effectors. Most of them, like pH, temperature and pCO2 can be always kept at a fixed standard level, whereas DPG, the main one, cannot.

Adolescent↗