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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 19 recordsLinked to original sources
PubMed1992

Molecular and biological properties of an abrin A chain immunotoxin designed for therapy of human small cell lung cancer.

An immunotoxin (IT) comprising abrin A chain attached to the mouse monoclonal antibody SWA11, recognising a cell surface antigen highly associated with human small cell lung cancer (SCLC), was synthesised using a hindered disulphide crosslinker, N-succinimidyl 3-(2-pyridyldithio) butyrate (SPDB), and purified by Blue Sepharose CL-6B affinity chromatography. The IT preparation contained monomeric conjugate, composed of one abrin A chain molecule linked to one SWA11 molecule, and was free from unconjugated A chain or antibody. The IT fully retained the cell-binding capacity of the antibody component and the ribosome-inactivating activity of the A chain. In cytotoxicity assays using the SW2 SCLC cell line in tissue culture, SWA11-SPDB-abrin A chain inhibited the incorporation of 3H-leucine by 50% at a concentration of 10 pM and by 99% at a concentration of 1 nM. The anti-tumour efficacy of the IT was tested in nude mice bearing established s.c. solid SW2 tumour xenografts. A single i.v. injection of SWA11-SPDB-abrin A chain at a non-toxic dose induced a significant 7 to 10 day growth delay that could not be matched by administration of equivalent doses of either unconjugated SWA11 or abrin A chain alone. The results of this study indicate that the antigen recognised by SWA11 is an effective target for therapy of SCLC with A chain ITs in vivo.

Abrin↗
PubMed1992

Effects of oral contraceptives containing oestrogen combined with norethisterone or levonorgestrel on erythrocyte cation transport in normal women.

1. Studies were undertaken in pre-menopausal women to examine the effects of treatment with standard oestrogen-progestogen and progestogen-ony oral contraceptives on erythrocyte Na+,K+ co-transport and Na(+)-Na+ countertransport over 3- and 6-month periods. Concurrent observations were made on other erythrocyte cation transport components, plasma lipid concentrations, plasma renin activity, plasma aldosterone concentration and blood pressure. 2. Na+,K+ co-transport, measured as the ouabain-resistant, frusemide-sensitive component of 86Rb+ influx, and Na(+)-Na+ countertransport, measured as the ouabain-resistant, phloretin-sensitive component of 22Na+ influx, were both increased in women taking, on days 1-21 of their cycle, ethinyloestradiol (30-50 micrograms) combined with norethisterone (1000 micrograms or 500-1000 micrograms) for 3 or 6 months. Neither of these fluxes was increased in a control group of women, or in women treated for the same time periods with ethinyloestradiol combined with levonorgestrel. 3. In a separate study of erythrocyte cation transport (excluding Na(+)-Na+ countertransport), in which women undertook treatment with norethisterone only (350 micrograms/day) for 6 months starting 6 weeks post partum, no changes in Na+,K+ co-transport were observed at 3 or 6 months; there were no changes in cation transport in a corresponding control group. 4. The results of these studies confirm that certain oral contraceptive compounds can alter erythrocyte cation transport, and indicate that norethisterone in higher dose preparations is the component predominantly responsible. The alterations observed could not be explained by a direct link with concurrent changes in plasma triacylglycerol concentrations or in the renin-aldosterone axis and were not closely associated with elevation of blood pressure.

Adolescent↗
PubMed1979

State mental hospitals and the future.

There seems to be a general acceptance of the idea that at some future date mental hospitals will disappear to be replaced by community mental health services of various kinds. The author points out that remarkably little interest is focused on the possibility of a new model of residential care to replace the outmoded hospital. Some form of residential mental health care will probably always be needed, and should be complementary to the developing nonresidential services. A strategy for revitalizing mental hospitals is outlined.

Communication↗
PubMed1979

Sensitivity differences displayed by Drosophila melanogaster larvae of different ages to the toxic effects of growth on media containing aflatoxin B1.

Using Drosophila melanogaster, the relative sensitivities of various larval stages to the toxic effects of growth on media supplemented with either 0.44 or 0.88 ppm aflatoxin B1 (AFB1) were determined. Two strains of fruit flies were tested: strain A-11 which is relatively resistant to AFB1 induced toxicity, and strain A-9 which is quite sensitive. Eggs, mid-first, mid-second and early-, mid- and late-third instar larvae were transferred onto AFB1 media and allowed to complete larval and pupal development and eclose as adults. At the 0.44 ppm concentration, strain A-11 showed no effect, while only first instar larvae of strain A-9 showed significant mortality rates for first instar larvae, but the A-9 larvae die at higher rates than the A-11 larvae. In addition, second and third instar larvae of strain A-9 show significant mortality rates when grown at 0.88 ppm AFB1, while these stages are not affected in strain A-11.

Aflatoxins↗
PubMed1979

Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia.

Cerebral blood flow (CBF) was studied in non-exteriorized near-term sheep fetuses using the radioactive microsphere technique. By partially occluding the umbilical vessels for a period of 1--1 1/2 hours a progressive and severe asphyxia with a final arterial pH of 6.90 was achieved. Varying the mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship--loss of autoregulation--was found, with hyperemia reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky to the albumin tracer Evans blue. In four other fetuses umbilical cord clamping was omitted. However, only in one of these cases was acidosis completely avoided, and CBF autoregulation maintained. The three other fetuses were acidotic at the end of the surgical procedure and had impaired autoregulation.

Animals↗
PubMed1979

Therapeutic communities, old and new.

The author attempts to clarify two largely different uses of term, Therapeutic Community (TC). By "old" TC he describes a movement which originated in psychiatry in the United Kingdom at the end of World War II. This was an attempt to establish a democratic system in hospitals where the domination of the doctors was replaced by open communication of content and feeling, information sharing, shared decision making, and problem solving shared as far as possible with all patients and staff. Daily meetings of all patients and staff formed the nucleus of this process. In recent years developments in the areas of systems theory, learning theory, and organization development have contributed to a better understanding of social organization and change. The "new" TCs derive from the more recent developments in the treatment of substance abuse. Central to this movement is Synanon and its many modification which use the clients' peer group to solve their own problems, largely eliminating mental health professionals. Linked with these "new" TCs is the development of Asklepieion units in prisons, which use Synanon "games" along with transactional analysis. An attempt is made to distinguish the methodologies used in TCs, "old" and "new".

Alcoholics Anonymous↗
PubMed1979

Biochemical quantitation of the chemotactic factor inactivator activity in human serum.

CFI of whole human serum was measured by a new assay that utilizes chemotactic factor-induced release of a lysosomal enzyme (N-acetyl glucosaminidase) from cytochalasin B-exposed neutrophils as an index of chemotactic activity. The effectiveness of serum as an inactivator of chemotactic factor-induced enzyme release closely correlated with the serum CFI as determined by assay of neutrophil chemotaxis in Boyden chambers. In comparison to serum from healthy persons, there was elevated CFI in the serum from patients with sarcoidosis and Hodgkin's disease by both assay systems. The results indicate that measurement of serum inhibition of chemotactic factor-induced lysosomal enzyme release from neutrophils provides a rapid, reliable, and reproducible assay of serum CFI. (J Lab Clin Med 93:17, 1979.)

Chemotaxis, Leukocyte↗
PubMed1978

The effects of triton WR1339 and asialo-fetuin on the hepatic uptake of circulating native and asialo-carcinoembryonic antigen.

Uptake of carcinoembryonic antigen from the circulation of the mouse is inhibited by treatment of the animal with Triton WR1339, but not by asialo-fetuin. Uptake of asialo-carcinoembryonic antigen is inhibited by asialo-fetuin, but not by Triton WR1339. These results reflect the different mechanisms of uptake of the glycoproteins. The presence or absence of sialic acid does not seem to be important in governing Kupffer-cell uptake, but when terminal galactoses are exposed on a glycoprotein, uptake by hepatocytes is preferred. Kupffer-cell uptake of carcinoembryonic antigen is not due to the formation of high-molecular-weight complexes in the blood stream. The effect of asialo-fetuin and Triton WR1339 on the biliary excretion of carcinoembryonic antigen and asialo-carcinoembryonic antigen is discussed.

Animals↗