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Biomedical subjects

G Santini

Publications and source records attributed to G Santini.

At least 163 records · Page 9Linked to original sources

Intraspecific polymorphism of sex chromosome heterochromatin in two species of the Anopheles gambiae complex.

The Hoechst 33258 banding pattern of the mitotic chromosomes of several laboratory and natural populations of the sibling species A. gambiae and A. arabiensis has been analyzed. A clear intraspecific polymorphism of sex chromosome heterochromatin has been observed. Nevertheless in each species heterochromatic variations fall within a characteristic species-specific pattern. Moreover, while laboratory polulations tend to be monomorphic for a given heterchromatic variant, natural populations exhibit a high degree of intrapopulation polymorphism. The possible role of sex chromosome heterochromatin in controlling fertility and mating behaviour of Anopheles mosquitoes is discussed.

Animals↗

[A new sign for finding the epidural space].

After a survey on the technique used for peridural anaesthesia, presence of pain determined by using bidistilled water as "liquid mandrel" when this is injected into the "peridural" space is reported. The use of this substance to identify this space, is suggested and an attempt explain mechanism of such pain is made.

Anesthesia, Epidural↗

Lack of spontaneous sister chromatid exchanges in somatic cells of Drosophila melanogaster.

Neural ganglia of wild type third-instar larvae of Drosophila melanogaster were incubated for 13 hours at various concentrations of BUdR (1, 3, 9, 27 micrograms/ml). Metaphases were collected with colchicine, stained with Hoechst 33258, and scored under a fluorescence microscope. Metaphases in which the sister chromatids were clearly differentiated were scored for the presence of sister-chromatid exchanges (SCEs). At the lowest concentration of BUdR (1 microgram/ml), no SCEs were observed in either male or female neuroblasts. The SCEs were found at the higher concentrations of BUdR (3, 9, And 27 micrograms/ml) and with a greater frequency in females than in males. Therefore SCEs are not a spontaneous phenomenon in D. melanogaster, but are induced by BUdR incorporated in the DNA. A striking nonrandomness was found in the distribution of SCEs along the chromosomes. More than a third of the SCEs were clustered in the junctions between euchromatin and heterochromatin. The remaining SCEs were preferentially localized within the heterochromatic regions of the X chromosome and the autosomes and primarily on the entirely heterochromatic Y chromosome.--In order to find an alternative way of measuring the frequency of SCEs in the Drosophila neuroblasts, the occurrence of double dicentric rings was studied in two stocks carrying monocentric ring-X chromosomes. One ring chromosome, C(1)TR94--2, shows a rate of dicentric ring formation corresponding to the frequency of SCEs observed in the BUdR-labelled rod chromosomes. The other ring studied, R(1)2, exhibits a frequency of SCEs higher than that observed with both C(1) TR94--2 and rod chromosomes.

Animals↗

Bone marrow transplantation for severe aplastic anemia. A report of 9 cases.

9 patients with severe aplastic anemia (SAA) were treated with bone marrow transplantation (BMT). 5 were conditioned with cyclophosphamide and received and HLA-identical graft (4 patients) or a mismatched graft (1 patient): 1 rejected the graft on day 30 and died on day 34 during conditioning for a second transplant; 1 died on day 15 with acute and severe graft versus host disease (GvHD) in the absence of haemopoietic engraftment; 3 are alive and complete chimeras at 1,069, 490 and 332 days after transplantation. GvHD developed in 4 patients and was treated successfully in 3 with high dose methylprednisolone and/or antilymphocytic globulin (ALG). 4 patients were conditioned with ALG and received bone marrow from a haploidentical sibling or parent: 1 patient was refractory; 3 patients showed evidence of hematologic reconstitution, but 2 of these required a second course of ALG. 3 patients in this group are alive between 60 and 490 days; 1 patient died on day 121 of HBSAg-negative acute hepatitis.

Adolescent↗

3h-actinomycin-D binding to mitotic chromosomes of Drosophila melanogaster.

The binding of 3H-AMD to the metaphase chromosomes of Drosophila melanogaster has been analyzed after two different periods of exposure to photographic emulsion. The entirely heterochromatic Y chromosome was markedly less labelled than euchromatin and other heterochromatic regions. Moreover, the few grains present on the Y chromosome were clustered in two regions, one localized in the middle Ys and the other in the proximal third of YL. This labelling pattern is not affected by removing histones with a 2-hour treatment with 2N HCl. It is suggested that the specific underlabelling of the Y chromosome reflects a peculiar AT richness.

Animals↗

Lymphoid antigens on blast cells in the agranular metamorphosis of chronic myelogenous leukaemia.

Undifferentiated blasts from a Ph'-positive chronic myelogenous leukaemia (CML) in terminal metamorphosis were reacted in an indirect immunofluorescence test with antilymphocytic globulins (AHLGs), raised against cultured lymphoblasts, thoracic duct and peripheral blood lymphocytes from healthy donors. After proper myeloid and/or monocytic absorptions the AHLGs interacted strongly with the undifferentiated blasts of CML, while this was not true for parallel controls with non-lymphoid leukaemias, both acute and chronic. The intensity of fluorescence, as determined by the use of a microfluorimeter, on these agranular blasts was comparable to the positivity of lymphoid cells from acute and chonic lymphatic leukaemias. These findings lend further support to the conception of a lymphoblast-like variety of terminal blastic crisis in chronic myelogenous leukaemia.

Antigens, Surface↗