Expression of immunological markers on leukemic cells before and after cryopreservation and thawing

We have studied the effects of cryopreservation on the viability and on the expression of surface antigens of acute leukemia cells. Marrow samples were obtained at initial diagnosis from 89 patients with acute myeloid leukemia (AML), acute undifferentiated leukemia (AUL), and acute lymphoid leukemia (ALL). In AML, the mean viability was greater than 90% in the types M1, M4, and M5 of the French-American-British classification, 79% in M2, and 3% in M3 types. The viability was 74% in AUL. In ALL, the viability was 95% for pre-B leukemias, but only 2% in T-cell leukemias. The expression of myeloid antigens was studied before and after freezing and thawing using three monoclonal antibodies (NHL30.5, against poorly differentiated granulocytic leukemias, VIMC6 against differentiated granulocytic leukemias and granulocytes; and UCHM1 or CRIS-6, against monocytic leukemias and monocytes). The percentage of cells stained by NHL30.5 and UCHM1 or CRIS-6 was very similar before and after cryopreservation. For VIMC6, the mean staining after cryopreservation was 60% of the initial one. In pre-B ALL, the stainings by anti common ALL antigen before and after cryopreservation were also very similar. We conclude that leukemic cryopreserved cells are suitable for immunologic studies. The recovery is, however, very low in promyelocytic AML and T-cell ALL.     

Effect of chronic ingestion of iodide during pregnancy and lactation on rat pup brain enzymes

The developmental pattern of several key enzymes in brain of pups born to mothers receiving high levels of iodide (1.1 mg daily intake) during pregnancy and lactation were followed up to the weaning period. We found that in the initial states of postnatal development, glutamic dehydrogenase increased above control levels, whereas succinic dehydrogenase decreased. At late stages, we observed differences in phosphofructokinase and malic enzyme activities which were all increased at 30 days. There was no change in hexokinase. Animal weight did not vary with respect to controls and we only obtained discrete increases (not statistically different) in serum thyroxine values, which led us to assume that the enzymatic modifications might be a consequence of either a very mild hormonal alteration or to the direct effect of iodide.     

Foraging-efficiency-predation-risk trade-off in the grey squirrel

Many animals must often respond to environmental patterns that simulatneously influence both foraging efficiency and predation risk. We noted that grey squirrels (Sciurus carolinensis) sometimes immediately consume food items in areas of relatively great exposure to predators, and at other times carry food items to the safety of a tree prior to consumption. We outlined a hypothesis that the squirrels were somehow trading-off energy intake rate against predation risk. A simple model shows that maximal energetic efficiency is associated with immediate consumption, whereas (under the field conditions studied) carrying items to the safety of trees provides for minimal exposure to predation. Our analysis of the model predicts that the tendency to carry a food item should decrease with distance of food from cover (travel time) and increase with item size (handling time). To test our predictions, we presented free-roaming grey squirrels with patches containing a fixed number of identical food items. We estimated the proportion of items carried to trees before consumption for 12 different combinations of distance to the nearest tree and item size. The results support our hypothesis and indicate that a simple behavioural criterion based solely on foraging rate or time exposed to predators is insufficient to explain the variation in the data.     

Light- and electron microscopic observations on parathyroid glands in different age groups of rats

The parathyroid hormone (PTH) acts on bones, intestines, and kidneys to maintain the calcium homeostasis which, in turn, is a main factor in controling the parathyroid (PT) gland activity. In all mammals studied, the chief cells of PT glands changed their size, shape, and cytoplasmic structure due to different functional states which vary the serum calcium levels. The chief cells of the rat PT glands were classified as dark and light. The dark cells may constitute an active form, characterized mainly by the abundant free ribosomes, conspicuous rough endoplasmic reticulum, and GOLGI complexes, greater number of secretory granules (SG) and increased tortuosity of the plasma membranes as compared to the light ones which were considered as a less active type of cells. Due to different calcium requirements in newborn and young rats for the ossification of growing skeleton and in adult and senile rats with consolidate mature bones, the PT glands studied with electron microscope showed various cytological features. The parenchyma of newborn and young PT glands was composed by dark chief cells. The light chief cells were more frequent in adult and senile animals as a less active type of cell. Mature SG were only occasionally observed in dark cells of newborn, young and adult PT glands. They may constitute a reserve supply of PTH but probably not the main way of secretion, according to their little number. Another pool of PTH probably answers the needs for the small basal variations in the steady-state secretion and may be represented by the vesicles observed in the chief cells cytoplasm.     

Allosteric effect of protons and adenosine triphosphate on hemoglobins from aquatic amphibia

Summary The analysis of hemoglobins from two anurans, one semi-aquatic (Leptodactylus labyrinthicus) and the other aquatic (Pipa carvalhoi), showed several components isolated by CM-cellulose chromatography. The two major components (Hb II and Hb III) ofL. labyrinthicus and the major components (Hb III and Hb IV) ofP. carvalhoi possess functional properties as follows: i.P. carvalnoi Hb III and Hb IV andL. labyrinthicus Hb II had very small Bohr effects (–0.05) and a substantial heterotropic effect with polyphosphates. ii.L. labyrinthicus Hb III produced a normal Bohr effect of –0.17, with no influence of polyphosphates.The authors wish to dedicate this paperin memoriam of Prof. Eraldo Antonini who contributed much to the knowledge of hemoglobins     

Purification of Tissue Forms (Amastigotes) of Trypanosoma cruzi by Immunoaffinity Chromatography1

A rapid and simple method for the purification of amastigotes of Trypanosoma cruzi from spleens of infected mice is described. A protein A-Scpharose 4B immunoadsorbent column bound with antisera to epimastigotes of T. cruzi was used to purify the tissue forms of this parasite. Host cells and debris are not retained, and parasites can be eluted in high yields and purity. Studies of surface glycoproteins and glycolipids of the purified amastigotes with 18 lectins of various specificities revealed the presence on the parasites of receptors for N-acetylglucosamine, N-acetylgalactosamine, D-galactose, and D-mannose binding lectins.     

Serum beta 2 microglobulin in adult myeloid acute leukemias

Serum beta 2 microglobulin levels, measured by radioimmunoassay (Phadebas test), were found increased in acute myeloid leukemias at diagnosis. Serum beta 2 microglobulin levels were significantly higher in patients with monocytic leukemias (13 patients, M4-M5 FAB classification) than in those with other cytological types (18 patients). Beta 2 microglobulin levels at diagnosis were correlated with serum lysozyme levels, but they were not correlated with blood blast counts, serum LDH and ferritin levels. 195 serum beta 2 microglobulin measurements were made serially in 30 patients with acute myeloid leukemias in first remission. Compared to values at diagnosis, beta 2 microglobulin levels in remission were significantly decreased. Out of 30 patients in remission 12 had increased serum beta 2 microglobulin levels (greater than 3 mg/l). Serial measurements were not predictive for relapses.     

Behavior of triatomines (Hemiptera: Reduviidae) vectors of Chagas' disease. II. Influence of feeding, lighting and time of day on the number of matings, mating speed and duration of copulation of Panstrongylus megistus (Burm, 1835) under laboratory conditions

To determine the influence of feeding, lighting and time of day on the copulating behavior of Panstrongylus megistus, 480 insect pairs were divided into four groups of 120 each and tested in the following respective situations: without food deprivation (F.D.), with five days of F.D., with ten days of F.D., and with 20 days of F.D. The tests were performed between 9:00 a.m. to 12:00 a.m. and 7:00 p.m. to 10:00 p.m., with light (700-1400 lux) and in the dark (1.4-2.8 lux) and behavior was recorded by the time sampling technique. Mating speed (MS) and duration of copulation (DC) were also calculated for each situation. The maximum frequency of copulation was observed after five days of F.D., at night, in the dark (n = 16), and the minimum was observed for recently-fed pairs, at night, with light (n = 4). Males approached females more often than females approached males. MS was lowest in pairs with twenty days of F.D., at night, with light (mean = 23.0 +/- 16.0 minutes), and highest in recently-fed pairs, during the day, with light (mean = 2.9 +/- 2.5 minutes). DC was shortest in recently-fed insects, during the day, in the dark (mean = 23.5 +/- 6.7 minutes), and longest in recently-fed animals, at night, in the dark (mean = 38.3 +/- 6.9 minutes).     

Chromosomal location of the active NORs in theSteropleurus martorelli complex

The chromosomal location of the active NORs has been analyzed by a silver impregnation procedure in theSteropleurus martorelli complex. A primary NOR, which is always present at the first meiotic prophase, has been found in each of the four described races. In addition to this, all races possess one or two secondary NORs which are less active than the former and can be occasionally shown. Usually only one of the two homologous chromosomes has been found to be involved with nucleolus organisation.These results are discussed in relation to hypotheses on the chromosome differentiation of this species complex.     

Comparative studies of seed proteins of the genusArtocarpus with respect to lectins

Proteins from two species of the genusArtocarpus (A. integrifolia L. andA. incisa L.) were compared by ammonium sulphate fractionation, molecular sieve chromatography and SDS-polyacrylamide gel electrophoresis, with special attention to the lectins. The protein content and hemagglutinating activity were markedly different in the two seeds. The protein pattern obtained by both molecular sieve chromatography and SDS-polyacrylamide gel electrophoresis were quite different. The only similarities found were the elution volume of the lectins in the Sephadex G-100 column and the lectin bands (11 500 and 15 000 daltons) in SDS-polyacrylamide gel electrophoresis.