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Biomedical subjects

E Rabino-Massa

Publications and source records attributed to E Rabino-Massa.

At least 19 recordsLinked to original sources

Functional studies on nine different haemoglobins with high oxygen affinity.

Nine carriers of beta-abnormal haemoglobins with increased oxygen affinity (Hb X) were examined. Their oxygen dissociation curves from whole blood were more or less left-shifted, with six of nine also characterized by biphasism. This refers to an 'inflection point' usually positioned at about 50-60% of Hb O(2) saturation, commonly believed to be a limit between oxygenation of the normal and abnormal components. In effect, the inflection does not always correspond to the Hb X level, which sometimes is much lower than 50% of the total Hb. Moreover, the upper half segment of the dissociation curve could not only be an expression of Hb A oxygenation, since it is always left-shifted. However, a high Hb A level is commonly believed to be the main compensatory factor of these subjects, but many indications suggest that often they have at least three, and not only two, main haemoglobin species: Hb A, Hb X plus hybrids of the type alpha(2)beta(A)beta(X). These would oxygenate after Hb X, but before Hb A. Finally, the interaction of 2,3-diphosphoglycerate with Hb X and/or hybrid tetramers must be altered, and the releasing of oxygen from both is more or less reduced. Unfortunately, it is difficult to demonstrate the presence of hybrids directly, i.e. with amino acid analysis of the abnormal beta-globin.

Chromatography, High Pressure Liquid↗

Molecular characterization of a rare hemoglobin variant: Hb-Hinsdale: beta139(H17)ASN-->Lys.

The authors describe the characteristics of a rare hemoglobin mutant found in a young female. She carries the aminoacid replacement of Hb-Hinsdale:beta139(H17)ASN-->Lys, which was identified at molecular level. This case, clinically and hematologically symptomless, is identical, but genetically independent, to the cases first described in an American family.

Asparagine↗

Direct DNA analysis in a new Italian carrier of Hb-Belfast: beta 15 (A12) Trp-->Arg.

A young woman aged 21 was found to be a new carrier of Hb-Belfast: beta 15 (A 12) Trp-->Arg, and the characteristics of her hemoglobinopathy were not different from those of the four cases so far described: mild hemolysis with molecular instability of the abnormal Hb, red cells inclusion bodies, and slight alterations of some functional parameters of whole blood. On this occasion, direct DNA analysis indicated the genomic nucleotide replacement of the disease: TGG-AGG. This was inherited by the mother, originating from Bari (Apulia).

Adult↗

[Three-dimensional facial reconstruction of computerized tomography images by computer-aided design: example of an anthropologic study].

Thanks to the medical scanning techniques and the reliability of some applications programs in 3D reconstruction, we are now able to explain an observation methodology based on the example of an anthropology study on Egyptian mummies'heads through a non-destructive proceeding. We have managed to demonstrate the exploration of the cervicofacial anatomy in the three dimensions of space and the possibility of dissociating the different anatomical tissues. The authors would like to point out the various consequences such a methodology may engender in any field.

Adult↗

[Functional analysis of diluted solutions of human hemoglobin by using Oximeter-3000 WTW equipped with Trioxmatic-300 electrode].

The oxygen carrying capacity of dilute solutions of hemoglobin from normal human adults was examined, by using the above indicated Oximeter. The results show that, if the pO2s are compared with those drawn from the Oximeter-539 WTW (a simpler instrument) carrying the same oxygen electrode, there is a good correspondence between the data drawn from both the instruments. The advantage of the former is that pO2s are measure in mBr, whereas the latter measures the oxygen of the aqueous solutions in mg/l; then mg must be converted into Torr pO2. Since both instruments are usually employed in the oxygen measurement of waste waters of earth, another conclusion is that their sensitivity also allows the use in the bio-medical (and zoological) field. In fact, the data obtained agree with those of recent literature on the subject, which are mainly drawn from automated and sophisticated apparatuses specifically built at this purpose.

Adult↗

Hemoglobin Agenogi [beta 90 (F6) Glu-->Lys] found in Piedmont. Case report.

An electrophoretically slow-moving hemoglobin, with abnormal beta chains, has been found in a young woman and in three members of her family. This variant amounted to 41% of the total Hb, and did not cause important clinical manifestations, although characterized by decreased oxygen affinity. Structural and aminoacid analyses revealed the mutation of Hb-Agenogi: 90 (F6) Glu-->Lys, a rare variant so far detected in unrelated racial and ethnic groups. This is the first affected family of ascertained Piedmontese ancestry.

Adult↗

Use of the Oximeter-539 WTW, equipped with a sensor Trioxmatic-300, for the functional analysis of dilute solutions of human Hb-A.

Dissociation curves for oxygen of dilute samples of human adult Hb-A were evaluated on this occasion, by using the Oximeter-539 WTW with its sensor, and a suitable spectrophotometer. At this purpose, Hb samples were desaturated in oxygen upon given experimental conditions, by bubbling pure nitrogen in them, and their re-oxigenation in air was followed, step by step, by multiple oximetries. In addition, all the spectrophotometric measurements of the saturation of Hb-O2%, corresponding to each individual oximetry, were carried out parallely but separately. Dilution of Hb-A was maintained at 0.1 mM in heme. The p50 at pH 7.3 was 4.435 +/- 0.299 Torr, with the n-value of 2.7 +/- 0.2; Bohr effect was -0.55 +/- 0.08, within a pH range between 6.8, 7.3 and 7.8, whereas chloride and DPG effects at pH 7.3 (the most useful value) were 0.42 +/- 0.44 and 0.453 +/- 0.0187 respectively. In conclusion, these results are similar to those obtained with automated procedures, upon comparable experimental conditions, but do not require expensive and sophisticated instruments. Such a technique could be very useful in the hemoglobinopathies, which are common in Italy, and it could be easily adapted to perform comparative studies on animal hemoglobins not far from human species.

Adult↗

Studies on the oxygen transport in the clinical association between Hb-S and Hb-C.

The whole blood oxygen affinity of a Negro carrier of SC disease was found to be characterized by some right-shifted p50 and clearly increased Bohr effect, whereas the isolated and purified Hb-S and Hb-C exhibited slight deficiencies mainly of the Bohr effect. The right-shifted p50 from whole blood can be easily explained by the mild anemia with a parallel increase of 2,3-diphosphoglycerate (DPG), whereas the functional discrepancies between whole blood function and that of the purified Hb-S and C could be due, at least in part, to the presence in vivo of consistent amounts of hybrid Hb tetramers of the type alpha alpha beta S beta C. Unfortunately, the mechanism promoting the formation (or dissolution) of hybrids are fundamentally unknown; so, either their presence and functional properties are very difficult to be explored.

Adult↗

Functional properties of dilute Hb solutions studied without tonometric techniques.

The authors found that, by continuously bubbling pure nitrogen within a dilute Hb solution, the latter releases its oxygen with an intensity which is quite proportional to the duration of bubbling. Such a procedure can be employed instead of the common tonometric technique, to measure functional properties of Hb. In fact, not only dissociation curves can be obtained, but also a correct evaluation of the affinity changes upon pH variations (Bohr effect). The results obtained by this technique are not far from those recently reported by using tonometry, although the method is less precise and still not suitable for routine purposes. Nevertheless, it can be substantially improved.

Hemoglobinometry↗

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↗

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↗

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↗