scholarly journals HETEROCHROMATIN IN HUMAN MALE LEUKOCYTES

1963 ◽  
Vol 16 (2) ◽  
pp. 315-322 ◽  
Author(s):  
A. Lima-de-Faria ◽  
J. Reitalu
Keyword(s):  
Dna Synthesis ◽  
Blood Cells ◽  
Tritiated Thymidine ◽  
White Blood Cells ◽  
Central Position ◽  
Interphase Nuclei ◽  
Human Male ◽  
Chromosome Segments ◽  
Silver Grains ◽  
The Eu

Tritiated thymidine was added to peripheral blood cultures containing phytohemagglutinin so that DNA synthesis in interphase nuclei of white blood cells in the human male could be studied. After 57 hours in culture, a large heterochromatic body with a central position is seen in unlabeled Feulgen-stained nuclei. In labeled nuclei in which DNA synthesis was taking place in both the eu- and heterochromatin at the time the thymidine became available, the heterochromatin shows a higher number of silver grains per unit area, accompanied by a stronger Feulgen reaction, an indication of its higher DNA content. The time of DNA synthesis in the heterochromatin blocks is different from that in the surrounding euchromatin. The large heterochromatic block is composed of chromosome segments gathered together around the nucleolus but it is not part of this organelle. In preparations stained with azure A and acid fuchsin for demonstrating both the nucleolus and the chromosomes, six distinctly heteropyenotic chromosome segments can be seen associated with the nucleolus. Cells of all size categories were found to incorporate tritiated thymidine. The distinct appearance of autosomal heterochromatin in white blood cells may be the result of the new physiological conditions to which the cells are subjected in the medium containing phytohemagglutinin.

scholarly journals THE FINE STRUCTURE OF THE DNP COMPONENT OF THE NUCLEUS

1963 ◽  
Vol 16 (1) ◽  
pp. 29-51 ◽  
Author(s):  
Elizabeth D. Hay ◽  
J. P. Revel
Keyword(s):  
Fine Structure ◽  
Dna Synthesis ◽  
Interphase Nucleus ◽  
Deoxyribonucleic Acid ◽  
Tritiated Thymidine ◽  
Proliferating Cells ◽  
Interphase Nuclei ◽  
Ultrathin Sections ◽  
Silver Grains ◽  
Dense Chromatin

In the present investigation, the sites of deoxyribonucleic acid (DNA) synthesis and the fate of labeled deoxyribonucleoprotein (DNP) were studied in autoradiographs of ultrathin sections viewed with the electron microscope. Tritiated thymidine was employed as a label for DNA in the nuclei of proliferating cells of regenerating salamander limbs. In the autoradiographic method reported here, dilute NaOH was used to remove the gelatin of the emulsion after exposure and development. The exposed silver grains are not displaced by this treatment and the resolution of fine structure in the underlying section is greatly improved. Our observations suggest that the DNP component is a meshwork of interconnected filaments 50 to 75 A in diameter, which may be cross-linked to form what Frey-Wyssling would term a "reticular gel." The filamentous DNP meshwork is dispersed throughout the interphase nucleus during DNA synthesis, whereas in chromosomes, which are relatively inert metabolically, the meshwork is denser and is aggregated into compact masses. Dense chromatin centers in interphase nuclei are similar in fine structure to chromosomes and are also inert with respect to DNA synthesis. In the Discussion, the structure of the filamentous meshwork in chromatin is compared with that in chromosomes, and speculations are made as to the functional significance of the variations in DNP fine structure observed.

scholarly journals Megaloblastosis Produced by a Cytosine Antagonist

Blood ◽  
1963 ◽  
Vol 21 (3) ◽  
pp. 352-362 ◽  
Author(s):  
R. W. TALLEY ◽  
V. K. VAITKEVICIUS
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Mechanism Of Action ◽  
Cytosine Arabinoside ◽  
Peripheral Blood ◽  
Blood Cells ◽  
White Blood Cells ◽  
Structural Similarity ◽  
Mitotic Abnormalities ◽  
Temporary Decrease

Abstract 1. Cytosine arabinoside induced objective, but temporary, decrease of tumor masses in three patients with lymphosarcoma and slight decrease in some lesions in two out of ten treated patients with disseminated carcinomatosis. 2. In doses of 3 to 50 mg./Kg. given at varying intervals, cytosine arabinoside induced definite megaloblastic changes in the marrow of all patients studied. Mitotic abnormalities similar to those found in other megaloblastic anemias also occurred. 3. Associated with bone marrow changes, depressions of hemoglobin, white blood cells and platelets in the peripheral blood were observed. 4. The exact mechanism of action of cytosine arabinoside has not been elucidated. It is speculated that because of the close structural similarity between cytidylic acid, cytosine arabinoside could interfere with DNA synthesis.

scholarly journals THE REPLICATION TIME AND PATTERN OF THE LIVER CELL IN THE GROWING RAT

1963 ◽  
Vol 18 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Joseph Post ◽  
Cheng-Ya Huang ◽  
Joseph Hoffman
Keyword(s):  
Dna Synthesis ◽  
Liver Cell ◽  
Tritiated Thymidine ◽  
Liver Cells ◽  
Male Rats ◽  
Interphase Nuclei ◽  
Replication Time ◽  
Wistar Strain ◽  
Growing Rat ◽  
Liver Cell Population

Three-week-old male rats of the Wistar strain were given tritiated thymidine, 1 µc/gm body weight, intraperitoneally and were killed at intervals from 0.25 to 72 hours later. Autoradiographs were made from 5 µ sections, stained by the Feulgen method. The replication time and its component intervals were determined from the scoring of the labeling of interphase nuclei as well as of prophase, metaphase, anaphase, and telophase nuclei. Absorption of the intraperitoneally injected label is rapid and is attended by "flash" labeling during interphase. The results show that at any one time about 4 per cent of the liver cells are synthesizing DNA preliminary to cell division. These cells alternate with waves of other cells and it is estimated that about 10 per cent of the liver cell population is engaged in cell duplication. The replication time is about 21.5 hours, and its component intervals occupy the following times: DNA synthesis, 9 hours; post-DNA synthesis gap, 0.50 hour; prophase, 1.3 hours; metaphase, 1.0 hour; anaphase, 0.4 hour; telophase, 0.3 hour; postmitosis gap, 9.0 hours. A group of liver cells has been recorded in at least 3 successive replication cycles.

scholarly journals The Kinetics of Cell Proliferation in Cultures of Human Peripheral Blood

Blood ◽  
1962 ◽  
Vol 19 (3) ◽  
pp. 349-358 ◽  
Author(s):  
ARCHIE A. MACKINNEY ◽  
FREDERICK STOHLMAN ◽  
GEORGE BRECHER
Keyword(s):  
Cell Proliferation ◽  
Tissue Culture ◽  
Dna Synthesis ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Human Peripheral Blood ◽  
Tritiated Thymidine ◽  
Small Population ◽  
Peripheral Blood Cells ◽  
Kinetics Of

Abstract The kinetics of growth of peripheral blood cells in tissue culture are described. There was a rapid increase of cells in DNA synthesis beginning at 24 hours and by 72 hours 40-45 per cent of the cells were in DNA synthesis. Mitotic rates of ∼ 1 per cent/hour were seen after 72 hours in cultures. Studies with tritiated thymidine and colchicine indicated that these cells represent transformed lymphocytes and do not arise from the cells in DNA synthesis at time zero or from any other small population of cells.

scholarly journals DURATION OF PREMEIOTIC DEOXYRIBONUCLEIC ACID SYNTHESIS AND THE STAGES OF PROPHASE I IN RABBIT OOCYTES

1970 ◽  
Vol 47 (3) ◽  
pp. 577-584 ◽  
Author(s):  
J. J. Kennelly ◽  
R. H. Foote ◽  
R. C. Jones
Keyword(s):  
Dna Synthesis ◽  
Meiotic Prophase ◽  
Deoxyribonucleic Acid ◽  
Tritiated Thymidine ◽  
Acid Synthesis ◽  
Prophase I ◽  
Meiotic Prophase I ◽  
Maximum Duration ◽  
Deoxyribonucleic Acid Synthesis ◽  
Silver Grains

To estimate the duration of oocyte DNA synthesis 36, 3-day-old female rabbits received 3, 6, 9, 12, 15, or 18 injections of tritiated thymidine (thy-3H) at hourly intervals. The ovaries, removed at 1, 10, or 20 days after the first injection, were radioautographed. Counts made of the number of silver grains associated with oocyte nuclei in meiotic Prophase I indicate that the duration of DNA synthesis is between 9 and 12 hr. To determine the length of the stages of meiotic Prophase I, a group of 2-3-day-old rabbits was given a single sub-cutaneous injection of thy-3H, and the ovaries were removed at hourly and/or daily intervals after treatment. The minimum duration of leptotene was 3 hr and the maximum duration probably was less than 8 hr. The maximum durations of zygotene, pachytene, and diplotene were estimated to be 44, 216, and 96 hr, respectively. The interval from the end of oogonial DNA synthesis to the beginning ofpremeiotic DNA synthesis (G2 + Mitosis + G1) appeared to be less than 6 hr.

Ultrastructural changes in murine lymphoma cells exposed to ultraviolet-A radiation

1991 ◽  
Vol 49 ◽  
pp. 104-105
Author(s):  
Delma P. Thomas ◽  
Dianne E. Godar
Keyword(s):  
Medical Devices ◽  
Blood Cells ◽  
White Blood Cells ◽  
Consumer Products ◽  
Ultrastructural Changes ◽  
Ultraviolet A ◽  
Uv Spectrum ◽  
Lymphoma Cells ◽  
Murine Lymphoma ◽  
Transmission Electron

Ultraviolet radiation (UVR) from all three waveband regions of the UV spectrum, UVA (320-400 nm), UVB (290-320 nm), and UVC (200-290 nm), can be emitted by some medical devices and consumer products. Sunlamps can expose the blood to a considerable amount of UVR, particularly UVA and/or UVB. The percent transmission of each waveband through the epidermis to the dermis, which contains blood, increases in the order of increasing wavelength: UVC (10%) < UVB (20%) < UVA (30%). To investigate the effects of UVR on white blood cells, we chose transmission electron microscopy to examine the ultrastructure changes in L5178Y-R murine lymphoma cells.

The Effect of Red Blood Cells on the ADP-induced Aggregation of Human Platelets in Flow Through Tubes

1990 ◽  
Vol 63 (01) ◽  
pp. 112-121 ◽  
Author(s):  
David N Bell ◽  
Samira Spain ◽  
Harry L Goldsmith
Keyword(s):  
Platelet Aggregation ◽  
Shear Rate ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Platelet Rich Plasma ◽  
Mean Transit Time ◽  
White Blood Cells ◽  
Aggregate Size ◽  
Human Platelets ◽  
Induced Aggregation

SummaryThe effect of red blood cells, rbc, and shear rate on the ADPinduced aggregation of platelets in whole blood, WB, flowing through polyethylene tubing was studied using a previously described technique (1). Effluent WB was collected into 0.5% glutaraldehyde and the red blood cells removed by centrifugation through Percoll. At 23°C the rate of single platelet aggregtion was upt to 9× greater in WB than previously found in platelet-rich plasma (2) at mean tube shear rates Ḡ = 41.9,335, and 1,920 s−1, and at both 0.2 and 1.0 µM ADP. At 0.2 pM ADP, the rate of aggregation was greatest at Ḡ = 41.9 s−1 over the first 1.7 s mean transit time through the flow tube, t, but decreased steadily with time. At Ḡ ≥335 s−1 the rate of aggregation increased between t = 1.7 and 8.6 s; however, aggregate size decreased with increasing shear rate. At 1.0 µM ADP, the initial rate of single platelet aggregation was still highest at Ḡ = 41.9 s1 where large aggregates up to several millimeters in diameter containing rbc formed by t = 43 s. At this ADP concentration, aggregate size was still limited at Ḡ ≥335 s−1 but the rate of single platelet aggregation was markedly greater than at 0.2 pM ADP. By t = 43 s, no single platelets remained and rbc were not incorporated into aggregates. Although aggregate size increased slowly, large aggregates eventually formed. White blood cells were not significantly incorporated into aggregates at any shear rate or ADP concentration. Since the present technique did not induce platelet thromboxane A2 formation or cause cell lysis, these experiments provide evidence for a purely mechanical effect of rbc in augmenting platelet aggregation in WB.

White blood cells levels and PCOS: direct and indirect relationship with insulin resistance, but not with hyperandogenemia

2013 ◽  
Author(s):  
Olga Papalou ◽  
Sarantis Livadas ◽  
Athanasios Karachalios ◽  
Nektarios Benetatos ◽  
George Boutzios ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Blood Cells ◽  
White Blood Cells ◽  
Indirect Relationship

Endogenous Heparinoids Detected by anti-Xa Activity are Present in Blood during Acute Variceal Bleeding in Cirrhosis. A Prospective Study

2014 ◽  
Vol 23 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Christos Triantos ◽  
Emmanuel Louvros ◽  
Maria Kalafateli ◽  
Anne Riddell ◽  
Ulrich Thalheimer ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Variceal Bleeding ◽  
Blood Cells ◽  
Venous Pressure ◽  
White Blood Cells ◽  
International Normalized Ratio ◽  
Ulcer Bleeding ◽  
Factor X ◽  
Packed Red Blood Cells ◽  
Bacterial Peritonitis

Background & Aims: Endogenous heparinoids have been detected by thromboelastography and quantified by clotting based anti-Xa activity assays in patients with cirrhosis, but their presence in variceal bleeding has not been established yet.Methods: Clotting based anti-Xa activity was measured in A) 30 cirrhotics with variceal bleeding, B) 15 noncirrhotics with peptic ulcer bleeding, C) 10 cirrhotics without infection or bleeding, and D) 10 cirrhotics with hepatocellular carcinoma (HCC).Results: Anti-Xa activity was not detected in ulcer bleeders or in cirrhotics without infection or bleedingbut was present in seven (23%) variceal bleeders (median levels: 0.03 u/mL (0.01-0.07)) and was quantifiable for 3 days in six of seven patients. Four of seven variceal bleeders with anti-Xa activity present had HCC (p=0.023). Age, creatinine, platelet count and total infections the second day from admission were significantly correlated with the presence of measureable anti-Xa levels (p=0.014, 0.032, 0.004 and 0.019, respectively). In the HCC group, anti-Xa activity was present in three patients (30%) [median levels: 0.05 u/mL (0.01-0.06)].Conclusions: In this study, variceal bleeders and 30% of the patients with HCC had endogenous heparinoids that were detected by a clotting based anti-Xa activity assay, whereas there was no anti Xa activity present in patients with cirrhosis without infection, or bleeding or HCC, nor in those with ulcer bleeding. Thus, the anti-Xa activity is likely to be a response to bacterial infection and/or presence of HCC in cirrhosis.List of abbreviations: AFP, alpha-fetoprotein; aPTT, activated partial thromboplastin time; CP, Child-Pugh; FXa, activated factor X; GAGS, glycosaminoglycans; Hb, hemoglobin; HCC, hepatocellular carcinoma; HVPG, hepatic venous pressure gradient; INR, International normalized ratio; LMWHs, low molecular weight heparins; MELD, Model for End-stage Liver Disease; PPP, platelet-poor plasma; PRBC, packed red blood cells; PT, prothrombin time; SBP, sponataneous bacterial peritonitis; TEG, thromboelastography; WBC, white blood cells.

Sign in / Sign up

Export Citation Format

Share Document