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Biomedical subjects

G Astaldi

Publications and source records attributed to G Astaldi.

At least 37 records · Page 2Linked to original sources
PubMed1978

Effect of human serum thymic factor on immature T lymphocytes in acute leukemia and other hematologic malignancies.

In 37 patients with acute leukemia and in 13 patients with other hematologic malignancies, E-rosette formation of peripheral blood mononuclear cells, before and after incubation with human serum thymic factor, was studied. This assay showed that incubation with thymic factor caused a clear-cut increase of E-rosette-forming cells in 8 of the 37 acute leukemia patients. Among the 13 patients with other hematologic malignancies, a similar effect was observed in two with pediatric Hodgkin's disease and in one adult with Waldenström's macroglobulinemia. These results support the contention that a significant percentage of the so-called "null" cells circulating in the blood of the above-mentioned patients were, in fact, immature T cells (T0 lymphocytes) that were shifted to a more mature stage (T1) by thymic factor.

Child↗
PubMed1978

Effects of hyperthermia and drug in cultured mammalian cells.

Hyperthermia (42 degrees C) and peptichemio (PTC) applied simultaneously result in an increased killing effect and in a significant induction of single strand breaks (SSB) of DNA molecule. The enhanced killing effect was observed in all circumstances, whenever hyperthermia was applied before, during or after PTC treatment, but the most effective cell killing was obtained when hyperthermia and PTC were applied simultaneously. The results show that PTC concentrations used in these experiments do not induce SSB in DNA molecule during incubation for 2 hours at 37 degrees C. When the cells were exposed to PTC and hyperthermia the induction of SSB was observed. The number of SSB depends on the exposure time and PTC concentration. Cells with a greater number of SSB lost the capacity for repair during post-incubation at 42 degrees C.

Cell Survival↗
PubMed1978

Cell separation, cell differential and granulocyte colony frequency in polycythemia vera.

In seven patients with polycythemia vera, the agar colony growth of bone marrow total nucleated cell suspensions and of the cell fractions obtained with an albumin discontinuous density gradient were studied. In one patient, the density distribution of colony-forming units in culture (CFUc) before and after alkylating treatment was evaluated and cell differentials on smears obtained from each density fraction were determined. A high percentage of low density CFUc compared with the total CFUc population and with that in the normal control subjects in the same density fractions was observed.

Bone Marrow↗
PubMed1977

E-rosette forming lymphocytes in acute leukemia before and after cell incubation with human serum thymic factor.

The Authors studied the effect of the human serum thymic factor on the peripheral blood leukocytes from ALL patients, by testing the frequency of the E+ cells by means of the E rosette assay before and after cell incubation with this factor. In four out of twenty-four patients tested, the thymic factor incubation of peripheral blood mononuclears increased the number of E+ cells. The shift from E- to E+ cells caused by the human serum thymic factor occurred among null cells (E-, SM-Ig-). The possible value of the test in investigating whether a T0 leukemia might really exists is pointed out, as well as its prospective importance in monitoring the variations of the immature T cell counts in relationship to the patient's treatment and his disease course.

Cell Count↗
PubMed1977

Experimental and clinical investigations on stem cell take and colony formation.

First, lymphocyte transplantation into total body-irradiated rats is discussed. The effect on spleen colony formation caused by the transplantation of untreated lymphocytes, as well as of lymphocytes previously incubated with PHA, or with PHA plus L-asparaginase, or with lymphokines, was studied. Then the effect of the urinary colony-stimulating factor in vitro, and the in vitro feeder-layer activity of leucocytes on colony formation of human and mice bone marrow cells in haematological diseases is dealth with. The injection of rat lymphocytes previously incubated for 24 hours with PHA resulted in a higher number and a larger size of colonies in the spleen of the recipient rats. Lymphocytes preincubated with lymphokines gave rise to the formation of spleen colonies which were larger than those developing after the injection of untreated lymphocytes. When the lymphocytes were previously incubated with PHA plus L-asparaginase, PHA failed to stimulate colony formation in the spleen. The phenomenon is explained by assuming that PHA, as an aspecific stimulator of cell division, initiated the division of CFUs, thus the CFUs content of the preincubated samples increased, resulting in an increase in the number of colonies formed after the transplantation of lymphocytes pretreated with PHA. Another possible explanation is that CFUs division, or their spleen take is enhanced by the immunocompetent lymphocytes activated by PHA, either directly or via soluble mediators produced or released by immunocompetent lymphocytes such as lymphokines. The study of colony-forming cells and colony-stimulating activity in primary myelofibrosis (PM) showed an increase in the number of circulating CFUc in this condition, and an abnormal density of these cells reaching a peak below 1.062. The lowering of CSA in the first two peripheral blood gradient fractions agrees with the observation in the same fractions of a high percentage of CFUc at the expense of the CSC population. Thus, double cell population seems to exist in PM. One is greatly abnormal with a low specific density and high plating efficiency, whereas the other population is almost normal, showing a higher specific density and a lower plating efficiency.

Animals↗
PubMed1976

Trace elements and immunologic defects. Zinc deficiency and activity of lysosomal acid phosphatase in lymphocyte of mice.

Activity of lysosomal acid phosphatase in peripheral blood lymphocytes of mice fed a low-Zn diet has been studied. The study comprised 40 CBA T6T6 mice, female, aged 8 weeks, with body weight equal to about 18.0 g. The animals were fed during 10 days with a low-Zn diet. This latter diet, as well as the control one contained 0.8 mg% and 11.4 mg% of zinc, respectively; potable water contained 0.06 mg% of this element. Activity of the enzyme was determined semiquantitatively using cytochemical method of Barka and Anderson. Peripheral blood lymphocytes in mice fed a low-Zn diet exhibited statistically significant lowering of the intracellular enzyme activity when compared with control groups. Absolute count of enzyme-positive lymphocytes was also significantly lowered. The Authors discuss the importance of their observations for evaluation of immune reactivity in trace-elements-deficient animals.

Acid Phosphatase↗
PubMed1976

With reference to a simple kit for short-term lymphocyte culture tested in experimental animals.

The results on blastic transformation of peripheral-blood lymphocytes from different species of experimental animals studied in short-term cell culture made with a fully pre-prepared Kit, are here illustrated and discussed. Lymphocyte donors were: mice, rats, hamsters, guinea-pigs, and rabbits. The Kit used in these experiments was the so-called Blasto-Kit, prepared by the Istituto Sieroterapico Milanese. It contains a lyophilized mixture of all the culture medium components, including the mitogen (in our study: PHA). The lyophilized mixture was diluted with the proper solvent just at the culture time, and then supplemented with 5 drops (200 mul) of whole blood. The extent of blastic transformation was evaluated in morphology, by counting the blast-like cells on culture smears; but the method provides adequate data also when lymphocyte transformation is evaluated via the extent of 3H-Tdr incorporation. The results showed quite significant discrimination (blastic indices) between the mitogen stimulated cultures and the non-stimulated controls in all the animals tested. On the other hand, different transformation extents were observed in relationship to the single animal species: it appeared that guinea-pigs, and mostly the rabbits gave the most beautiful blast-like cells, which appears to indicate that they are the most appropriate for this study among all those tested. It should be finally emphasized that : (1) the simplicity of the method makes the investigation on the transformation capability of lymphocytes easy to be carried out in every Lab; and (2), the small quantity of blood which is needed to perform the test makes it possible to investigate each single animal even in the case, when it has to be examined before, during, and after given treatments.

Animals↗
PubMed1976

Administration of peripheral-blood rat-lymphocytes stimulated "in vitro" with human lymphokines and spleen colonies in the total body irradiated rat.

It was previously reported that PHA-incubation of a pool of peripheral-blood lymphocytes before their i.v. injection into rats submitted to total body irradiation, stimulates spleen colony formation and growth. On the same model, the present study has investigated the effect of lymphocyte preincubation with supernates obtained in short term cultures from human lymphocytes prestimulated with PHA (lymphokines). The "in vitro" culture of rat lymphocytes in a medium supplemented with human lymphokines showed either a marked increase of lymphocyte survival rate, or significant stimulation of lymphocyte blastogenesis, but at an extent much lower than that caused by PHA, also because in this particular experiment the culture medium was supplemented with too little amount of lymphokines. These data support the interpretation that human lymphokines may act across the species barriers. Peripheral-blood rat lymphocytes prestimulated with human lymphokines, and then injected i.v. into rats previously submitted to total body irradiation, caused significant increase in the spleen weight, as well as formation of spleen colonies quite larger and with higher erythroid differentiation - though less numerous than in the controls (i.e., in the rats injected just with untreated lymphocytes). This behaviour may be due to the tendency to merge together of two or more colonies in a single giant colony, and supports the interpretation that immune-competent lymphocytes activated either with PHA or with lymphokines may stimulate spleen colony growth and erythroid differentiation, though at different extents.

Animals↗
PubMed1976

L-Asparaginase: effect on 7S gamma globulin extents and germinal centers in spleen and lymph-nodes.

Administration of L-asparaginase may cause remission in a high percentage of acute lymphocytic leukemias and lymphomas, either in experimental animals or in human beings. This enzyme is able to depress immune reactions like lymphocyte blastogenesis and delayed hypersensitivity, and to impair gamma-globulin synthesis. L-asparaginase also has antigenic properties, and may cause the formation of anti-L-asparaginase antibodies. This study reports observations on the effect of L-asparginase on the 7S gamma-globulin levels and on the behaviour of the germinal centers in spleen and lymph nodes. It has been found that after administration of low or intermediate doses of L-asparginase, a decrease in the size of the follicular marginal zones occurred. This was accompanied by an enlargement of the germinal centers. Furthermore the spleen weight decreased and the concentration of 7S gamma-globulin diminished slightly. In animals given high doses of L-asparaginase, germinal centers were enlarged even more but marginal zones appeared repopulated although not to the degree of the controls. The spleen weight of these enzyme-injected animals reached almost the normal values, while a statistically significant decrease of 7S gamma-globulin concentrations was found.

Animals↗
PubMed1976

A preliminary study on humoral control of granulopoiesis in primary myelofibrosis and chronic granulocytic leukaemia.

The extent of the urine Colony Stimulating Factor (CSF/u), as well as the Colony Stimulating Activity (CSA) of peripheral-white blood cells (WBC) were evaluated in two groups of patients with myeloproliferative disorders, at the disease onset. The first patient group deals with Primary Myelofibrosis (PM), whereas the second group deals with Chronic Granulocytic Leukaemia (CGL). The Stanley technique was used for the above-mentioned assay, and in each group of patients either human or murine bone-marrow cell-suspensions were cultivated. In all patients with PM, a low CSF/u was detected, while patients with CGL showed a high CSF/u, regardless whether Ph1-positive or not. CSA of WBC in the PM-group was normal. In contrast, a significant low CSA in the CGL-group was noted. This fact could be of some importance in differentiating the two disorders at their onset.

Animals↗
PubMed1975

Beta-glucuronidase activity of lymphocytes in the premature infant with special reference to the fetal maturation stage.

Activity of beta-glucuronidase (GR) was determined cytochemically by the Hayashi et al. method on peripheral blood lymphocytes of 50 premature infants, born between 21st and 37th week gestation. The subjects studied were subtyped into group I (21st to 28th week), group II (29th to 33rd week), and group III (34th to 37th week). Absolute count of enzyme-positive lymphocytes was lower in group I, when compared with group II and III as a whole. Absolute count of GR-positive lymphocytes exhibiting granular reaction type was significantly lower in group I, when compared with other groups. Absolute counts of GR-positive cells, with both granular and diffuse, or diffuse enzymatic reaction did not differ in groups I, II and III. The results obtained indicate ontogenetic development of lysosomal granules containing GR in the lymphocyte cytoplasm in premature infants related to their fetal age.

Female↗
PubMed1975

Immunologic cell features in lymphocytic leukemias: a review.

Since four years, it has been possible to classify most cases of Chronic Lymphocytic Leukemia (CLL) as given to the expansion of abnormal B-lymphocytes. On the contrary, the T-cell class is apparently normal and the T cell extent in CLL-peripheral blood can be even greater than normal when taken as absolute value. The clonal nature theory of B-lymphocytes in CLL is substantiated by the fact that, in general, in every patient only one Ig light chain determinant is present. Again, when serum Ig monoclonality is present in CLL, it appears idiotypically identical to the Ig shown by the lymphocytes of the same patient. Among the most important B-lymphocyte abnormalities in CLL, there are: (a) fluorescence of surface Ig is usually less intense than that in normal subjects, and fluorescence intensity may vary not only from patient to patient, but also from cell to cell in the same patient; (b) the Fc-receptor can be lacking; (c) the C3b-receptor is not always present, or it is from 2 to 20 folds less frequent than the C3d-receptor, whereas normal human lymphocytes do not show any outstanding differences between the number of EAC rosette-forming cells either when tested with mouse complement (C3d-receptor) or with human complement (C3b-receptor); (d) the traffic capacity of peripheral-blood B-lymphocytes in CLL is quite defective. All the above-mentioned data, taken as a whole, suggest that CLL is in general given by the expansion of an abnormal clone of cells of B origin, arrested in their maturative development, non-responsive to the mitogen stimulation, accumulating in the peripheral-blood for a traffic deficiency.

Animals↗