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P R Harrison

Publications and source records attributed to P R Harrison.

At least 73 records · Page 4Linked to original sources
PubMed1979

Globin synthesis and erythroid differentiation in a Friend cell variant deficient in heme synthesis.

Friend erythroleukemia cells of line Fw are noninducible for hemoglobin synthesis by dimethyl sulfoxide, butyric acid, and other agents. However, these agents were found to induce hemoglobin synthesis if the cells were also treated with exogenous hemin. Butyric acid (or, to a lesser extent, dimethyl sulfoxide) by itself induced accumulation of the erythroid-specific membrane protein spectrin. The basis of the control of globin gene expression by hemin was investigated. Hemin does not control globin and total protein synthesis via the action of the hemin-controlled repressor. Rather, hemin, alone or in combination with dimethyl sulfoxide, induces accumulation of globin mRNA and nuclear globin RNA sequences. Direct measurements of heme synthesis indicate that Fw cells may be significantly deficient in heme metabolism.

Animals↗
PubMed1978

Human polyoma virus (HPV)--a significant pathogen in renal transplantation.

Routine cytological screening of Papanicolaou-stained smears of the urinary sediment from 57 renal allografts in 51 patients has resulted in the detection of seven cases of Human Polyoma Virus (HPV) BK infection--14% of the total number. Infection was confirmed by virus isolation and electron microscopy (EM). The cytological, histological and ultra-structural data are described and related to the clinical progress of the patient. Four out of the seven cases are discussed in more detail as histological material was available; in three of these, there was evidence of stenosis of the transplant ureter with virus infected cells in the ureteric epithelium and in one case also in the renal tubules. Administration of high dose steroids may provoke active infection with HPV in ureteric epithelium damaged by ischaemia and inflammation. The similarity between the clinical features of an HPV infection and a rejection episode make it imperative to confirm the diagnosis quickly and accurately. Cytological examination of the urinary deposit by light microscopy is a simple, inexpensive procedure which provides positive diagnosis of the typical virus inclusions within an hour of receiving the urine specimen in the laboratory. This can be confirmed by removing single cells from the original cytological slide preparation and processing them for EM using a technique described by Coleman et al [1].

Adolescent↗
PubMed1975

Iron incorporation and haemoglobin synthesis in erythropoietic cells during the ontogenesis of the mouse.

Iron incorporation (59Fe) into erythropoietic cells from adult and foetal (11- to 15-day) peripheral blood and from foetal (12- to 15-day) livers has been investigated. Ion-exchange chromatography of haemolysates from such cells revealed two groups of 59Fe-containing proteins. The first group (X-fraction) was eluted from CMC-columns in the void volume and was highest in lysates of immature erythropoietic cells. This fraction contained a radiolabelled haemprotein of high molecular weight as well as other 59Fe-containing proteins. The haemprotein does not appear to be related to haemoglobin. The second group consisted of haemoglobins. One major (A1) and two minor (A2 and A3) haemoglobins were found in adult peripheral blood. In foetal liver lysates two major (F1 and A1) and two minor (F2 and A3) haemoglobins were present. The relative proportion of the major haemoglobins changed during development. Haemoglobin F1 was highest in the more mature livers. F1 proved to be different from A1 by chromatographic behaviour, in polypeptide chain composition and in fingerprints. A unique foetal polypeptide chain, intermediate in electrophoretic behaviour between the adult alpha- and beta-chain, was identified. In young foetal peripheral blood (11-day), in which 95% of the cells are of yolk-sac origin, one major (E1), two intermediate (E2 and E3) and one minor (F1) haemoglobin were demonstrable. Haemolysates of the peripheral blood of older embryos contain haemoglobins from erythroid cells of both yolk-sac and foetal liver origin. The haemoglobin pattern of such lysates is explicable in terms of the decreasing amount of embryonic haemoglobins (E1, E2 and E3) and the increasing amount of foetal haemoglobins (F1 and A1). Since A1 and E1 are the most prominent haemoglobins of livers from young embryos and yolk-sac erythrocytes respectively, and since they are very similar in chromatographic behaviour, foetal peripheral blood at all stages contain one dominant haemoglobin peak in the A1-E1 region. Most authors have neglected the relatively slight elevation of the foetal haemoglobin peak (F1) in front of A1-E1, the more because the F1-A1 region has been suspected sometimes to contain artificial haemoglobin components (Riggs, 1965). This probably explains why no foetal haemoglobin (F1) has been reported previously in the peripheral blood of foetal mice.

Animals↗
PubMed1974

In situ localization of globin messenger RNA formation. I. During mouse fetal liver development.

Globin mRNA levels in 11-15-day mouse fetal liver cells have been estimated by in situ hybridization of a highly labeled DNA copy (cDNA) of adult globin messenger RNAs (mRNAs) (globin cDNA) to fixed preparations of cells. Under the conditions employed, no significant in situ hybridization occurred to lymphoma cells (L 51787), mouse L cells, or hepatocytes; whereas reticulocytes from phenyl hydrazine-treated mice showed extensive in situ hybridization. The proportion of fetal liver cells showing predominantly cytoplasmic in situ hybridization increased from about 30% at the 11th day of development to 80-85% by days 13-15. Unlike more mature cells, proerythroblasts did not show in situ hybridization, except to a slight extent at later stages of development. These studies therefore indicate that globin mRNAs begin to accumulate during or shortly after the proerythroblastbasophilic erythroblast transition. The fact that certain immature erythroid cells from 14-day fetal liver contain substantial amounts of globin mRNAs has been confirmed by comparing the hybridization in solution of globin cDNA to cytoplasmic RNA extracted from total fetal liver cells or from immature erythroid cells obtained by treatment of fetal liver cells with an antiserum raised against erythrocytes.

Animals↗
PubMed1974

In situ localization of globin messenger RNA formation. II. After treatment of Friend virus-transformed mouse cells with dimethyl sulfoxide.

Globin messenger RNA (mRNA) levels in Friend virus-transformed mouse cells have been estimated by in situ hybridization of DNA copy (cDNA) to fixed preparations of cells and by hybridization of cDNA to extracted cytoplasmic RNA in true solution. The results obtained by both methods agree in showing that a low level of globin mRNA can be detected in untreated Friend cells. The levels of hemoglobin and globin mRNA have also been correlated after treatment of Friend cells with dimethyl sulfoxide (DMSO). The results obtained by both experimental approaches show that there is a minimum period of treatment with DMSO required in order that Friend cells may become hemoglobinized, and that this period coincides with the time when globin mRNA accumulates. Moreover, bromodeoxyuridine prevents both hemoglobin and globin mRNA accumulation.

Animals↗