bluuebunny/crossref_metadata_2025_split huggingface dataset:
LYMPHOCYTE POPULATIONS IN MOUSE BONE MARROW: QUANTITATIVE KINETIC STUDIES IN YOUNG, PUBERTAL AND ADULT C3H MICE
Authors: Miller S. C. , Osmond D. G. 
Published: May 2008

AbstractContinuous 3H‐thymidine infusion was used to characterize two kinetic subpopula‐tions of small lymphocytes in mouse bone marrow during normal growth and development. Young (4 wk), pubertal (8 wk) and mature (16 wk) C3H mice were infused subcutaneously with 3H‐thymidine for periods up to 10 days. Femoral marrow was then examined in radioautographic smears. During the first 3 days the proportion of marrow small lymphocytes labelled by 3H‐thymidine showed a rapid exponential increase to 93%, 81% and 72% in 4 wk, 8 wk and 16 wk mice respectively. The rate of appearance of labelled small lymphocytes then declined markedly but remained higher in younger than in older animals. The labelling curves were found to represent the summation of two exponential curves from which the proportions and renewal rate of corresponding cell populations were calculated. Most marrow small lymphocytes comprised a rapidly renewing population but in mice of increasing age the relative incidence of these cells fell (93‐3% at 4 wk; 88‐0% at 8 wk; 78‐5% at 16 wk) and their half‐renewal time (T½) lengthened (14 hr at 4 wk; 18 hr at 8 wk; 24 hr at 16 wk). The remaining small lymphocytes were slowly renewing with mean T½ of 4, 7 and 14 days in 4, 8 and 16 wk mice, respectively. Some heavily labelled small lymphocytes persisted in the marrow up to 10 wk after fourteen daily 3H‐thymidine injections in 10–12 wk mice. The numbers of rapidly renewing cells decreased from 604 times 103 to 228 times 103 per mm3 of marrow from 4 wk to 16 wk, respectively, while slowly renewing cells increased from 44 times 103 to 61 times 103 per mm3. The total number of nucleated marrow cells per femur increased from 4 wk to 16 wk but the rapidly renewing small lymphocytes per femur fell in numbers by 36% and in renewal rate by 63%. The results demonstrate a selective change in bone marrow small lymphocytes with age; rapidly renewing cells decline in number and renewal rate while the number of slowly renewing cells increases. The concept of bone marrow as a primary lymphoid organ is discussed.
COLONY‐FORMING ABILITY OF BONE MARROW CELLS OF W ANAEMIC MICE ON MACROPHAGE LAYER FORMED IN PERITONEAL CAVITY OF MICE
Authors: Kitamura Y. , Kawata T. , Okano K. , Asayama S. , Seki M. 
Published: May 2008

AbstractThe colony‐forming ability of haematopoietic cells of W anaemic mice was examined on the macrophage layer formed in the peritoneal cavity of mice. Bone marrow cells of W anaemic mice formed a considerable number of colonies on the macrophage layer, notwithstanding they did not form any colonies in the spleen of the same recipients. As the colony‐forming ability of the bone marrow cells was not reduced by the incubation with 3H‐thymidine, most of the cells which formed colonies on the macrophage layer seemed to stay in G0 state. The interrelationship between the spleen colony‐forming cells, the macrophage‐layer colony‐forming cells, and in vitro colony‐forming cells was discussed.
EXISTENCE OF TWO CHALONE‐LIKE SUBSTANCES IN INTESTINAL EXTRACT FROM THE ADULT NEWT, INHIBITING EMBRYONIC INTESTINAL CELL PROLIFERATION
Authors: Brugal G. , Pelmont J. 
Published: May 2008

AbstractThe inhibiting effect of tissue extract from fully differentiated intestinal mucosa of adult animals on proliferation kinetics of exponentially growing embryonic epithelial gut cell populations was studied in the newt Pleurodeles waltlii. Crude extract was fractionated by G‐200 Sephadex chromatography and the effect of fractions on cell proliferation was studied using both mitotic index and 3H‐thymidine incorporation methods. The inhibitions we obtained were then displayed by means of cytophotometric study of age distribution of intestinal gut cells around the cell cycle, measuring the Feulgen‐DNA content. The results revealed the presence of two chalone‐like substances in the intestine of adults. One (factor 1) is characterized by a molecular weight of between 120,000 and 150,000 and inhibits the cell cycle at the end of the G1 phase, the other (factor 2) is characterized by a molecular weight lower than 2000 and inhibits the cell cycle in the course of the G2 phase. The cells delayed in the G2 phase escape from inhibition but the cells delayed in the G1 phase do not, although availability time of both factor 1 and factor 2 is about 12 hr. It is thus thought that cells prevented from dividing in G1 phase are indefinitely delayed in this phase and possibly differentiate.
KINETIC ANALYSIS OF CELL SIZE AND DNA CONTENT DISTRIBUTIONS DURING TUMOR CELL PROLIFERATION: EHRLICH ASCITES TUMOR STUDY
Authors: Kim M. , Woo Kwang B. 
Published: May 2008

AbstractIn order to study the growth dynamics of proliferating and non‐proliferating cells utilizing discrete‐time state equations, the cell cycle was divided into a finite number of age compartments. In analysing tumor growth, the kinetic parameters associated with a retardation in the growth rate of tumors were characterized by computer simulation in which the simulated results of the growth curve, the growth fraction, and the mean generation time were adjusted to fit the experimental data. The cell age distribution during the period of growth was obtained and by a linear transformation of the state transition matrices, was employed to specify the cell size and DNA content distributions. In an application of the model, the time‐course behavior of cell cycle parameters of Ehrlich ascites tumor is illustrated, and the parameters important for the transition of cells in the proliferating compartment to the non‐proliferating compartment are discussed, particularly in relation to the G1‐G0 and G2‐G0 transitions of non‐cycling cells as revealed by the variation of cell size distribution.
COMPARTMENTS AND CELL FLOWS WITHIN THE MOUSE HAEMOPOIETIC SYSTEM
Authors: Micklem H. S. , Ford C. E. , Evans E. P. , Ogden D. A. 
Published: May 2008

AbstractTwo chromosomally distinguishable haemopoietic cell populations were injected into lethally irradiated syngeneic recipients. The presence or absence of the T(14;15)6Ca reciprocal translocation (indicated by T6 marker chromosomes) did not affect the proliferation of a population. Wide disparities were found in the proportions of the two donor cell populations between animals and between the right and left femora of individual animals. This suggests (i) that there is, at most, a very limited interchange of proliferating cells and their precursors between the marrow of different bones; and (ii) that the number of clones proliferating in the bone marrow at any one time must be rather small; there was evidence that this number depended in part on the number of haemopoietic cells injected. Exchange between the mitotically active cell populations of spleen, thymus, lymph nodes and bone marrow was also limited, as shown by significant disparities in the proportions of the two donor populations proliferating in the different tissues of individual mice.
COMPARTMENTS AND CELL FLOWS WITHIN THE MOUSE HAEMOPOIETIC SYSTEM II. ESTIMATED RATES OF INTERCHANGE
Authors: Micklem H. S. , Ogden D. A. , Evans E. P. , Ford C. E. , Gray J. G. 
Published: May 2008

AbstractPart‐body irradiated CBA mice were injected with CBA‐T6 bone marrow. In this way a predominantly donor population was established in the femora while the marrow of the humeri remained largely (average 94 %) of host origin. In animals examined cytologically up to 2 years later, no tendency was observed for the proportion of donor cells in the humeri to increase. Splenectomy had no effect on this. When femoral bone marrow from the experimental mice was injected into lethally (whole‐body) irradiated recipients, cells originating from the primary host repopulated the lymph nodes to a disproportionate extent. Equilibration between the cell populations of femora and humeri occurred after re‐exposure to 600 rad whole‐body irradiation, but not after 100 rad or 350 rad; thus, regeneration of damaged bone marrow involved a significant contribution from extrinsic stem cells only after the highest dose of radiation.The data are compatible with an inflow of at most ten effective stem cells per humerus per day from the blood, and suggest a much lower figure. This means that few if any of the stem cells of peripheral blood enter the bone marrow and found haemopoietic clones. Evidence is adduced for the existence of a proliferating lymphoid sub‐population in the bone marrow, contributing some 5–10% of the observed mitoses.The mitotic cells in the lymph nodes are replaced from marrow‐derived progenitors at an estimated rate of 4–5 %/day. The relevant data for the thymus are more variable, but suggest an average figure of 8–11 %/day. Earlier data from mouse parabionts suggest a lower rate of inflow to the thymus.
A STUDY OF THE KINETICS OF MICROSPOROGENESIS IN CAMPELIA ZANONIA (L.) H.B.K.
Authors: Wigglesworth D. J. 
Published: May 2008

AbstractDuring maturation, microspores pass through a series of morphologically distinguishable stages or compartments. A study has been made of the systematic fluctuations in the frequency of microspores in these compartments, when plants are grown under rigidly controlled conditions.A new approach to the construction of cumulative flux rate curves is described; these give the number of cells passing the compartment boundaries per unit time. The curves obtained indicate that simple models, which assume constant flux rates and compartment transit times, will not explain the observations. It is evident that not only do microspores mature at different rates, but that the maturation rate of individual microspores varies during the developmental sequence. The overall process may be controlled by the intimate relationship which exists between the microspores and the tapetal periplasmodium in the Tradescantiae.
CELL PROLIFERATION IN WALKER TUMOUR GROWING IN THE STOMACH WALL
Authors: Broyn Terje 
Published: May 2008

AbstractTumour cells from a Walker carcinosarcoma 256 were implanted in the gastric mucosa in rats. The tumour grew and infiltrated the lamina propria and the submucosal space after 7 days. It appeared to grow faster in the submucosal space than in the lamina propria. The cell proliferation was therefore studied separately in: (1) the tumour in the lamina propria, (2) the main tumour mass and (3) the tumour periphery, defined as the cells located within the outer 100–120 μm of the tumour. Mitoses arrested with vinblastine, cells labelled with tritiated thymidine and the grain count per labelled cell were studied at the three different sites. The rate of cell proliferation in the tumour was highest in the lamina propria, lower in the centre of the main tumour mass, and lowest at the periphery. Cell loss might explain the discrepancy between the rate of cell proliferation and the actual tumour growth. The factors that influence tumour cell proliferation in the different parts of the tumour are discussed.
KINETIC‐MICROARCHITECTURAL CORRELATIONS IN THE BONE MARROW OF THE MOUSE
Authors: Shackney S. E. , Ford S. S. , Wittig A. B. 
Published: May 2008

AbstractTransverse histologic sections of bone marrow obtained from mice that were sacrificed by perfusion fixation at intervals following tritiated thymidine injection were studied by means of radioautography. A kinetic gradient was demonstrated across the marrow section, with the highest proliferative rate in the subendosteal region. Megakaryocytes were shown to originate from the rapidly proliferating subendosteal cells. The immediate proliferating precursors of mature granulocytes were slowly proliferating cells found predominantly in the central region of the marrow. It was concluded that in the steady state there must be a migration of cells from the subendosteal region to the central region with concomitant growth retardation of the migrating cells.
THE INDUCTION OF TRANSIENT INCREASES IN MITOTIC RATE IN MURINE TISSUES FOLLOWING PROLONGED INTRAVENOUS INFUSIONS OF HYDROXYUREA
Authors: Plager John 
Published: May 2008

AbstractIntravenous infusions of hydroxyurea were established in mice and maintained for periods up to 48 hr. The influence of different rates of hydroxyurea infusion on the number of viable cells gathered in S phase was studied in eight different mouse tissues. An infusion rate which was sufficiently slow not to block thymidine incorporation completely, resulted in gathering of cells in S phase while offering some protection against hydroxyurea‐induced cell death. The duration of the period of DNA synthesis following release from hydroxyurea inhibition appeared to be shortened in some tissues. After the release of hydroxyurea blockades maintained for 12–24 hr, each of the tissues showed sharp increases in mitotic activity and peak mitotic index values were as much as twenty times greater than values found in tissues of control animals. An important finding was that the time of maximal mitotic activity for different tissues after release of blockade could differ by many hours.
THE PRESENCE OF A CSF ENHANCING ACTIVITY IN THE SERUM OF ENDOTOXIN‐TREATED MICE
Authors: Engh Ger van den , Bol Simon 
Published: May 2008

AbstractSerum taken from mice a few hours after injection of endotoxin is a potent source of a stimulator of in vitro myelopoiesis. By means of dose‐response studies, the biological activity of this material was compared to that of a colony stimulating factor (CSF) from pregnant mouse uteri. Postendotoxin serum appears to contain two different activities: a stimulating activity which may be identical to CSF and an activity which augments the action of CSF. The separate nature of the two activities is demonstrated by differences in the rate at which they are diluted out and by differences in the time at which they are maximally present after endotoxin administration. It is therefore concluded that the colony‐stimulating properties of postendotoxin serum are not due solely to CSF present in the serum.
EVALUATION OF THE SPECIFICITY OF A LYMPHOID CHALONE
Authors: Garcia‐Giralt E. , Diaz‐Rubio E. , Rappaport H. 
Published: May 2008

AbstractAn extract from calf spleens, injected into mice, was found to inhibit their lymphocyte proliferative response to PHA‐M and PWM in vitro. Despite the ability of the spleen extract to inhibit the response of lymphocytes to stimuli in vitro, no effect was observed on the repopulation of lymphocytes in the peripheral blood of sublethally irradiated mice. The data suggest that the spleen extract acts as a specific inhibitor of the immune competent cells since neither the precursors of lymphocytes nor other haematopoietic cells were affected.
VARIATION OF CELL KINETIC PARAMETERS IN RELATION TO THE GROWTH RATE OF THE EHRLICH ASCITES TUMOR
Authors: Woo Kwang B. , Wiig Karl M. , Brenkus Larry M. 
Published: May 2008

ABSTRACTA multicompartmental model of the cell cycle and proliferation kinetics was used to analyse the time‐course behavior of the cell cycle time, the growth fraction, and the cell loss rate during Ehrlich ascites tumor growth. The growth rate of Ehrlich ascites tumor cells as the tumor aged was significantly influenced by change in the cell cycle time.
RECYCLING OF RESTING CELLS IN THE JB‐1 ASCITES TUMOUR AFTER TREATMENT WITH 1‐β‐D‐ARABINOFURANOSYLCYTOSINE (Ara‐C)
Authors: DOMBERNOWSKY P. , BlCHEL P. 
Published: May 2008

AbstractResting cells in tumours present a major problem in cancer chemotherapy.In the plateau phase of growth of the murine JB‐1 ascites tumour (i.e. 10 days after 2–5 × 106 cells i.p.) large fractions of non‐cycling cells with G1 and G2 DNA content (Q1 and Q2 cells) are present, and the fate of these resting cells was investigated after treatment with l‐β‐d‐arabinofuranosylcytosine (Ara‐C).The experimental work consisted of growth curves, percentage of labelled mitoses curves after continuous labelling with 3H‐TdR, and cytophotometric determination of single‐cell DNA content in unlabelled tumour cells.Treatment with an i.p. single injection of Ara‐C 200 mg/kg in the plateau JB‐1 tumour resulted in a significant reduction in the number of tumour cells 1 and 2 days later as compared with untreated controls, while no difference in the number of tumour cells was observed after 3 days. In tumours prelabelled with 3H‐TdR 24 hr before Ara‐C treatment, a significant decrease in the percentage of labelled mitoses was observed 6–8 hr later followed by a return to the initial value after 12 hr, and a new pronounced fall from 20 hr after Ara‐C. The second fall in the percentage of labelled mitoses disappeared when the labelling with 3H‐TdR was continued also after Ara‐C treatment. Cytophotometry of unlabelled tumour cells prelabelled for 24 hr with 3H‐TdR before Ara‐C treatment showed 20 hr after Ara‐C a pronounced decrease in the fraction of Qt cells paralleled by an increase in the fraction of unlabelled cells with S DNA content.These results indicate recycling of resting cells first with G2 and later with Gx DNA content, which contribute to the regrowth of the tumours.
CHANGES IN THE PROLIFERATION RATE OF MOUSE EPIDERMIS AFTER IRRADIATION: CONTINUOUS LABELLING STUDIES
Authors: Denekamp J. , Stewart F. A. , Douglas B. G. 
Published: May 2008

AbstractThe proliferative response of mouse skin to damage caused by X‐irradiation has been tested by giving repeated injections of tritiated thymidine and scoring the percentage of labelled cells in high resolution autoradiographs. Four, nine and fourteen daily fractions of 300 rads of X‐rays were used and labelling commenced 4 days after the last fraction. The epidermis of the upper surface and the sole of the foot were scored separately and were compared with the skin of unirradiated feet.In unirradiated skin the proliferation rate of the basal layer cells is more rapid on the sole than on the upper surface. The cell cycle times deduced from continuous labelling curves were 81 hr and 111 hr respectively and the growth fractions were 97% and 85%.After irradiation with small daily doses the homeostatic response to cell killing was slow. More rapid proliferation occurred after nine fractions in the sole, but was not apparent in the skin of the upper surface until fourteen fractions had been given. After fourteen fractions the cell cycle time was about 24 hr on both surfaces and the growth fraction was about 90%. The initial labelling index after a single thymidine injection was a poor measure of proliferation rate. The delay in the time of onset of faster proliferation is similar, both qualitatively and quantitatively, to that measured previously from the additional dose increments needed if large doses were given at different times after the multifraction treatments (Denekamp, 1973).
FETAL HEMOPOIESIS IN DIFFUSION CHAMBER CULTURES
Authors: Symann Michel , Fontebuoni Anna , Quesenberry Peter , Howard Donald , Stohlman Frederick 
Published: May 2008

AbstractThe growth pattern of fetal liver (FL), normal adult bone marrow (NABM) and regenerating (post Velban treatment) adult bone marrow (RABM) colony forming units (CFU) cultured in diffusion chambers (DC) was studied. When twenty CFU were implanted into DC the recovery of CFU after 4 days with FL, NABM or RABM was 133 ± 7, 19 + 2 and 34 ± 2 CFU, respectively. The transplantation fraction of CFU from NABM decreased from 10‐4% on day 0 to 6–9 % on day 4; that of FL did not change from the initial 6‐2%. The growth rate of CFU derived from FL was substantially greater than that from NABM. The relative growth of FL and RABM CFU was clearly inhibited when the concentration of cells cultured was increased. Spleen colonies from FL cells before culture were larger (P < 0–005) than colonies from NABM but after 7 days of culture there was no difference between the two groups. Histological examination of spleen colonies showed that after DC culture FL and NABM CFU were differentiating along the three normal pathways. These data suggest that intrinsic differences exist between fetal and adult stem cells in the in vivo diffusion chamber culture system.
SOME EFFECTS OF BLEOMYCIN ON THE PROLIFERATION, MATURATION TIME and PROTEIN SYNTHESIS OF HAIRLESS MOUSE EPIDERMIS
Authors: Iversen Olav H. , Clausen Ole P. F. , Iversen Ulla M. , Rohrbach Rolf 
Published: May 2008

AbstractHairless mice were given 2 mg Bleomycin i.p. in 1‐0 ml saline on two successive days. By a stathmokinetic method, by micro‐flow fluorometry and by autoradiography certain kinetic parameters were measured during 10 days after the last injection. Cell counts were made and the turnover time of the differentiating cells estimated. Protein synthesis was estimated by the uptake of radioactive histidine, and dry cell mass measured by weighing. Bleomycin affected cell proliferation in the epidermis by depressing biphasically both the number of cells in, and the passage of cells through, the cell cycle phases: S, G2 and M, most probably by directly affecting late Gj cells and cells in mitosis. The time between the two minima of depressed DNA synthesis corresponded to the mean generation time of the basal cells. Histidine uptake and dry cell mass were slightly affected, but the turnover time of the differentiating cells was prolonged.Bleomycin thus had a strong long‐lasting inhibitory effect on epidermal cell proliferation and a marked inhibitory effect on epidermal cell maturation in mice.
MODE OF GROWTH OF THE JEJUNAL CRYPT CELLS OF THE RAT: AN AUTORADIOGRAPHIC STUDY USING DOUBLE LABELLING WITH 3H‐ AND 14C‐THYMIDINE IN LOWER AND UPPER PARTS OF CRYPTS
Authors: Burholt Dennis R. , Schultze Brigitte , Maurer Werner 
Published: May 2008

AbstractThe frequency distribution of cells through the mitotic cycle in lower and upper portions of jejunal crypts of the rat was examined by the 3H‐14C‐thymidine double labelling technique. Isolated crypts were cut perpendicular to the longitudinal axis so that the percentage of cells in the lower portion varied from 16 to 74 %. The lower and upper portion of the same crypt were squashed separately on one microscope slide and the number of 3H‐ and 14C‐only labelled cells were scored to determine the flow rate into and out of S for the two portions. The mitotic cycle and its phases of the crypt epithelial cells were also determined.For lower portions of crypts which contained less than 40 % of the total cell number in that crypt the flow rate into S was about 1–7 times that of the flow rate out of S indicating that nearly every mitosis in this region produced two proliferative daughter cells. As the proportion of cells in the lower part of the crypt increased the quotient of the flow rate into S divided by the flow rate out of S decreased, and approached the steady state value of 1 0 in lower portions containing 60–74 % of the cells. For upper portions of crypts which contained less than 40% of the total crypt cells the flow rate into S was about 0 2 times that of the flow rate out of S, indicating that in this region mitoses predominantly produced non‐proliferative daughter cells. The results obtained were in good agreement with the model of crypt cell proliferation proposed by Cairnie, Lamerton & Steel (1965b).
STUDY OF CELL DEATH IN FRIEND LEUKAEMIA
Authors: Smadja‐Joffe F. , Klein B. , Kerdiles C. , Feinendegen L. , Jasmin C. 
Published: May 2008

AbstractCell death of splenic Friend leukaemic cells has been studied in vivo, using 125I‐UdR and 3H‐TdR pulse labelling. The evolution of the splenic specific activity has been measured by autoradiography and external counting during 40 hr after injection of the labelled precursor. These two techniques show the existence of a large reutilization of 3H‐TdR (50%), which is measurable as soon as 7 hr after the injection. The DNA turnover rate is rapid, 83‐8 % of the splenic cellular DNA being renewed per day. These results confirm that most of the cells produced in the Friend leukaemic spleen are rapidly lost; they also demonstrate that this cell loss is mainly due to a massive death, which occurs in proerythroblastic and erythroblastic compartments after one or two cell divisions.Friend leukaemic cells, which are characterized by a limited capacity of proliferation and a short lifespan, do not appear to be malignant.