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Biomedical subjects

E Nir

Publications and source records attributed to E Nir.

36 records · Page 2Linked to original sources
PubMed1981

Juvenile and adult types of chronic granulocytic leukemia of childhood: growth patterns and characteristics of granulocyte-macrophage colony forming cells.

Peripheral blood and bone marrow cells from three children with the juvenile (Ph1 negative) type of chronic granulocytic leukemia and from one with the adult (Ph1 positive) type were cultured in soft agar, and their specific growth patterns were evaluated. Greatly increased numbers of colonies were obtained in all cases, particularly from peripheral blood cells. By morphologic, cytochemical and ultrastructural criteria, colonies from one juvenile type and from the single adult type patients were found to be almost exclusively granulocytic, whereas in the other two juvenile type leukemia patients colonies were either granulocytic or macrophage. Moreover, both growth patterns were obtained in the same patients on different occasions. It appears that the leukemic cell populations of the juvenile and the adult forms of chronic granulocytic leukemia do not arise from different cell lines. Rather, both are the progeny of the common monocyte-granulocyte progenitor cell, whose abnormal proliferation and differentiation along either the granulocytic or the monocytic pathway is probably directed by fluctuations in humoral and/or microenvironmental factors.

Bone Marrow↗
PubMed1981

Cytomorphology and lysosomal enzyme activity of the haemopoietic and reticuloendothelial system of the SJL/J mouse.

The cytomorphology and lysosomal enzyme activity of the haemopoietic and reticuloendothelial system (RES) of SJL/J mice, which develop a spontaneous reticulum cell neoplasm type B (RCN-B), were studied. The cytological findings during development of the disease were a predominance of medium-sized lymphocytes and an increase in the number of hyperbasophilic cells and plasma cells in the RES. These pathological findings were compared to the changes due to ageing in control groups of healthy C3H/eB mice. Acid phosphatase activity increased in the RES, whereas that of beta-D-glucuronidase remained unchanged during development of the disease. These findings indicate that the RCN-B of the SJL/J mice bear a certain resemblance to Hodgkin disease in man.

Acid Phosphatase↗
PubMed1980

Granulocyte-macrophage colonies in cultures of human fetal liver cells: morphologic and ultrastructural analysis of proliferation and differentiation.

Fetal liver cells from 6-12-week-old human fetuses were cultured in soft agar to study growth patterns of the granulocyte-macrophage colony forming cells (CFU(c)) and to characterize the cellular components of these colonies by morphologic, cytochemical and ultrastructural methods. Liver cell suspensions prepared from 31 fetuses obtained by vaginal interruptions of pregnancies, were seeded in soft agar over feeder layers of normal human leukocytes. At all gestational ages examined, agar colony numbers ranged from 44 +/- 15 to 89 +/- 44/2 x 10(5) cells seeded. Colony frequencies, size and gross morphology closely resembled those derived from adult human marrow. Morphologic, cytochemical and ultrastructural examinations showed that 92% of the colonies were granulocytic with incomplete maturation, as found in adult human marrow colonies. Density fractionation of the cells produced a low density cellular fraction which gave a 3- to 5-fold improved cloning efficiency. This study shows that human fetal livers of 6-12 weeks gestational age contain CFU(c) comparable to that found in adult marrow in their frequency, size, density and dependence on colony stimulating factor, and which differentiate mainly into mature or immature granulocytes. It is suggested that the lack of granulopoiesis in vivo in the early human fetal liver is probably not related to CFU(c) deficiency or defective differentiation. An alternative explanation involving impaired regulatory mechanism(s) should be sought.

Cell Differentiation↗
PubMed1979

Myeloproliferative disorders terminating in acute micromegakaryoblastic leukaemia.

Two cases of myeloproliferative disorder--one of myelofibrosis with agnogenic myeloid metaplasia and one of chronic granulocytic leukaemia terminating in acute micromegakaryoblastic leukaemia--are presented. The clinical course is described, and results are reported of morphological, cytometric, cytochemical and cytogenetic studies, as well as cell culture of blood cells in soft agar and in fluid medium.

Adolescent↗
PubMed1979

Pseudo-Chediak-Higashi anomaly in acute myeloid leukaemia. An electron microscopical study.

2 cases of acute myeloid leukaemia with inclusion bodies are presented. The inclusions were found mainly in the blast cells but could also be encountered in lymphocytes and plasma cells. Cytochemical and ultrastructural studies showed a great resemblance of these inclusions to the ones found in Chediak-Higashi anomaly, i.e., high acid phosphatase activity, varying in size of inclusions from clusters of small granules to hugh inclusion, sometimes found in vacuoles, featuring fusion of lysosomes.

Acid Phosphatase↗
PubMed1978

An unusual type of congenital dyserythropoietic anemia with thalassemia features.

A 25-year-old male patient of Kurdish Jewish origin presented with mild anemia and splenomegaly. The acidified serum test was strongly positive with three of four normal sera and the anti-i agglutination of the red cells was negative. Hemoglobin electrophoresis showed an increase of Hb A2 (3.4%). Blood smears showed changes compatible with thalassemia. On bone marrow examination, approximately 3% of the normoblasts showed changes typical of dyserythropoiesis, including binucleated orthochromatic normoblasts and large trinucleated and quadrinucleated megaloblasts. Ultrastructural studies of the bone marrow cells revealed characteristic features of congenital dyserythropoietic anemia, including irregular cytoplasmic pseudopodia, perinuclear cisternae, intrusion of cytoplasmic material into the nucleus and incomplete cytoplasmic cisternae.

Adult↗
PubMed1977

Cellular immunity in newborn infants and children: stimulation of lymphocyte protein synthesis as a measure of immune competence.

An assay based on the early stimulation of protein synthesis in lymphocytes has been used as an in vitro measure of cellular immune competence. 3H-labelled leucine incorporation into human peripheral lymphocytes (PBL) stimulated by the mitogens phytohaemagglutinin (PHA), wax bean agglutinin (WBA) and Concanavalin A (Con A) was measured after one day in culture. This assay offers a technical advantage over the analogous 3H-labelled thymidine incorporation assay, because of the short incubation time required and the absence of homologous serum in the assay system. Newborn infants and patients with Down's syndrome as a group had normal responses, whereas those suffering from recurrent infections demonstrated normal or hyper-reactive responses. Patients with lymphoproliferative disorders, ataxia telangiectasia, and some patients under steroid therapy had diminished immune proliferative reactions. These results are in agreement with most previously reported studies using other assay systems.

Adolescent↗
PubMed1976

Effect of serum from leukapheresed mice on myelocytes, promyelocytes and colony-forming cells.

Leukapheresis of neutrophil granulocytes in mice increased the myelopoietic activity of their serum. Leukapheresed mouse serum (LMS) caused a threefold increase in the in vitro stathmokinetic index of myeloid precursors. Five to ten minutes of incubation were sufficient to change the colony-forming capacity of mouse bone marrow cells as expressed by the increase in the ratio of granuloid to erythroid cells in spleen colonies. The in vitro stathmokinetic index assay also showed that there are diurnal variations in levels of granulopoietic activity in normal mouse sera. However, at any time of the day, LMS had higher granulopoietic activity.

Animals↗
PubMed1976

Morphological and cytochemical investigation of human mesothelial cells from pleural and peritoneal effusions: a light and electron microscopy study.

We investigated the morphological and cytochemical properties of mesothelial cells obtained from pleural and peritoneal effusions of patients with various diseases. The morphological features were studied by light and electron microscopy and by cytochemical methods. The different kinds of contact between mesothelial cells and their interaction with lymphocytes were observed and the transition of mesothelial cells to macrophages and/or fibroblasts was demonstrated.

Ascitic Fluid↗
PubMedDate not supplied

Pairing of isolated nucleic-acid bases in the absence of the DNA backbone.

The two intertwined strands of DNA are held together through base pairing--the formation of hydrogen bonds between bases located opposite each other on the two strands. DNA replication and transcription involve the breaking and re-forming of these hydrogen bonds, but it is difficult to probe these processes directly. For example, conventional DNA spectroscopy is dominated by solvent interactions, crystal modes and collective modes of the DNA backbone; gas-phase studies, in contrast, can in principle measure interactions between individual molecules in the absence of external effects, but require the vaporization of the interacting species without thermal degradation. Here we report the generation of gas-phase complexes comprising paired bases, and the spectroscopic characterization of the hydrogen bonding in isolated guanine-cytosine (G-C) and guanine-guanine (G-G) base pairs. We find that the gas-phase G-C base pair adopts a single configuration, which may be Watson-Crick, whereas G-G exists in two different configurations, and we see evidence for proton transfer in the G-C pair, an important step in radiation-induced DNA damage pathways. Interactions between different bases and between bases and water molecules can also be characterized by our approach, providing stringent tests for high-level ab initio computations that aim to elucidate the fundamental aspects of nucleotide interactions.

Base Pairing↗