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Biomedical subjects

J Stone

Publications and source records attributed to J Stone.

At least 307 records · Page 17Linked to original sources
PubMed1978

The effect of heat-inactivated murine cytomegalovirus on host DNA synthesis of different cells.

Heat-inactivated murine cytomegalovirus (MCMV) stimulates cellular DNA synthesis in WME, NMG, 3T3, WgIA, chick and NIK-8 cells, but active or u.v.-irradiated MCMV does not. The stimulation of DNA synthesis in NIL-8 and chick cells was studied in detail. We found that both the nuclear and the mitochondrial DNA synthesis were stimulated in these cells. There was no virus DNA synthesis during the period we studied (48 h). The stimulation of nuclear DNA synthesis was about threefold in NIL-8 and 2.5-fold in chick cells as measured by the rate of incorporation of 3H-thymidine (3H-dThd) in the CsCl fractions which banded at the density of cell DNA. The stimulation was about 9.5-fold in NIL-8 and 1.7-fold in chick cells as detected by autoradiography. There was a 3-fold and a 2.2-fold increase in the degree of incorporation of 3H-dThd into mitochondrial DNA of NIL-8 and chick cells, respectively. The amount of mitochondrial DNA obtained in infected cells of both kinds was about twice that in control cells. The synthesis of mitochondrial DNA was also stimulated by a factor of 2 in the thymidine kinaseless 3T3 cells which incorporate exogenous thymidine exclusively into mitochondrial DNA. There were no MCMV specific antigens detectable by immunofluorescence 5 h after infection, but diffuse nuclear fluorescence could be demonstrated 24 h after infection. Our results indicate that the heat-inactivated virus penetrates the cells, stimulates host DNA synthesis and induces synthesis of early MCMV antigens.

Animals↗
PubMed1978

Evaluation of the usefulness of serum gamma-glutamyl transpeptidase levels in the management of haematological neoplasia.

The levels of serum gamma-glutamyl transpeptidase (GGT) and, when appropriate, alkaline phosphatase (AP) and 5'-nucleotidase (NTD) have been measured as a routine in 276 patients with malignant haematological diseases during a 26-month trial period. GGT levels add no prognostic information to the routine haematological surveillance of leukaemia. Polychemotherapy does not appear to be an inducer of liver drug-metabolising microsomal enzymes. Polycythaemia rubra vera, myelofibrosis and chronic lymphocytic leukaemia may cause little change in GGT, AP and NTD levels despite marked hepatomegaly. A raised GGT in Hodgkin's disease and non-Hodgkin lymphoma is generally associated with active and widespread disease, but not necessarily a sign of malignant tissue in the liver. The elevations of GGT in myeloma may be secondary to liver infiltration though this group merits further detailed study.

Hodgkin Disease↗
PubMed1977

Ten-year survival rates in breast cancer using combination chemotherapy.

The outcome in 254 patients with all stages of breast cancer treated by combination chemotherapy is presented. All the patients were treated 10 or more years ago. The 10-year survival rate for Stages I and II combined is 60 per cent, in Stage III 19 per cent and in Stage IV 3 per cent. The combined rate in Stages I and II differed markedly according to hormonal status. In premenopausal patients the rate was 84 per cent compared with 42 per cent in postmenopausal patients.

Adult↗
PubMed1977

Naming of neurones. Classification and naming of cat retinal ganglion cells.

Many schemes of ganglion cell classification seek to classify the cells by some particular characteristic, such as the time course of the cells' physiological responses or their dendritic morphology. It is here argued that such schemes are based on the Aristotelian concept of "essences" and raise the same difficulties as have arisen with the essentialist approach to animal taxonomy. A better approach to the classification of neurones, it is proposed, is to base the classification on as many features of the cells as possible, and to regard the classification as an hypothesis, subject to testing and modification by experience, about the "functional niches" occupied by the cell types distinguished.

Animals↗
PubMed1977

C bodies and R bodies in the epithelial cells of normal and diseased human rectum.

Small spherical, extracellular bodies (C bodies) measuring 20 to 80 nm in diameter and enclosed by a trilaminar membrane 7 nm wide surrounded the microvilli of human rectal epithelial cells. Similar bodies were observed within membrane-bound vesicles (R bodies) in the apical cytoplasm. The C bodies associated with the mature epithelial cells of the luminal surface were more numerous than those associated with the immature cells of the crypts, where the R bodies predominated. A decreased number of C bodies was observed in ulcerative colitis. We concluded that the membrane-bound C bodies surrounding the microvilli were cellular in origin and arose from R bodies within the cytoplasm of the rectal epithelial cells.

Cell Membrane↗
PubMed1976

Properties of ganglion cells in the visual streak of the cat's retina.

The properties of ganglion cells in the visual streak of the cat's retina have been investigated. Evidence is presented that the streak is formed principally, but not entirely, by a concentration of small-bodied ganglion cells with the receptive field properties and slow-conducting axons typical of W-cells.

Action Potentials↗
PubMed1976

Conduction velocity groupings among axons of cat retinal ganglion cells, and their relationship to retinal topography.

Three unresolved issues in the conduction velocity groupings among the axons of cat retinal ganglion cells have been investigated. These are (i) the degree of separation of the velocity ranges of the axons of X-and W-type ganglion cells; (ii) the question whether the velocities of X-and Y-cell axons (i.e. of t1 and t2 axons have faster velocities than contralaterally projecting axons. Evidence is presented that the velocity ranges of W- and X-cell axons are almost completely separate; that the velocities of X- and Y-cell axons are not graded with retinal eccentricity (except in the immediate vicinity of the area centralis) and that ipsilaterally projecting axons are not faster conducting that contralaterally projecting axons. These results provide a context for summarising present understanding of conduction velocity groupings among the axons of cat retinal ganglion cells.

Animals↗
PubMed1976

Chemoimmunotherapy for maintenance in acute myeloblastic leukemia.

Of 30 adult patients with acute myeloblastic leukemia, 14 achieved complete remission. Eight of these were given chemoimmunotherapy for maintenance. The immunotherapy consisted of intradermal pooled allogeneic leukemic cells (snap-frozen irradiated) and BCG vaccine given by Heaf gun, given twice in 4 weeks. The chemotherapy was given for 1 week in 4 weeks. The median duration of remission in these eight patients was 115+ weeks and the median duration of survival was 147+ weeks. The other six patients who were given chemotherapy only for maintenance had a median duration of remission of 15 weeks and a median survival of 52 weeks. The two groups cannot be compared properly, however, as allocation of patients was not random, and the chemotherapy differed significantly.

Adolescent↗
PubMed1976

Properties of relay cells in cat's lateral geniculate nucleus: a comparison of W-cells with X- and Y-cells.

1. Observations are presented on the physiological properties of W-, X-, and Y-type relay cells in the cat's lateral geniculate nucleus (LGN). Emphasis is placed on the most recently recognized type, W-cells; data are presented on X- and Y-cells by way of comparison. 2. Seventy-seven W-cells were recognized on 70 microelectrode penetrations through the LGN. They resembled W-type retinal ganglion cells in their responses to visual stimuli. Tonic (on-center and off-center) W-cells, phasic (on-, off- and on-off center) W-cells, suppressed-by-contrast, and color-coded cells were recognized. 3. W-type relay cells also resembled retinal W-cells in their maintained activity and receptive field-center diameters. 4. W-type relay cells comprised 11.5% X-cells 48.4%, and Y-cells 22.3% of all LGN cells encountered on a reference sample of 62 electrode tracks. W-cells were found in laminae C, C1, and C2, comprising 36.5% of the sample in these laminae, but were not encountered in laminae A or A1. X- and Y-cells were found in laminae A, A1, and C. Within lamina C there was a tendency for X- and Y-cells to be located dorsal to W-cells. There was thus a substantial dorsoventral segregation of W-cells from X- and Y-cells. W-cells being found in the ventral parvocellular component of the dorsal LGN. 5. Cells considered to be W-type relay cells were shown to respond to electrical stimulation of the optic nerve and chiasm at latencies which were longer than those of X- and Y-cells, and were consistent with their receiving monosynaptic input from retinal W-cells. Geniculate W-cells of all subtypes were activated antidromically from the visual cortex. Their antidromic latencies were, on the average, longer than for Y- or X-cells, indicating that W-type relay cells had slower axons as well as slower retinal afferents, than X- or Y-cells. 6. The visual cortex thus appears to receive input from all three major types of retinal ganlion cells (W-, X-, and Y-cells) relayed separately, in parallel, by different groups of relay cells.

Action Potentials↗
PubMed1975

Acid treatment of Drosophila deoxyribonucleic acid.

In cytologic preparations of chromosomes, acid-treated deoxyribonucleic acid (DNA) is found largely in the native state. However, acid treatments widely used for chromosome preparations produce significant amounts of depurination in DNA. DNA is similarly sensitive to depurination in intact cells or as purified DNA. If treated with alkali, these apurinic gaps can be converted to single strand breaks. Acid treatment has widely different effects on specific fractions of DNA. In Drosophila melanogaster 3% of the DNA is composed of very long tracts of pyrimidines (polypyrimidines) which are resistant to acid hydrolysis. The implications of these results for molecular cytogenetics are discussed.

Acetates↗
PubMed1974

Industrial deafness - prevention or compensation?

There has been rapid growth in the past decade in the development of legislation to control industrial noise. This article reviews the present situation with regard to employer's liability to protect workers from occupational deafness and an attempt is made to compare the cost to industry of the prevention of deafness with the cost of claims for compensation. A brief account is included of the methods which are available for the control of industrial noise and for the detection and prevention of occupational deafness.

Journal Article↗