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Biomedical subjects

J F Wright

Publications and source records attributed to J F Wright.

50 records · Page 3Linked to original sources
PubMed1984

Psychiatrists' attitudes to psychosurgery. Proposals for the organization of a psychosurgical service in Yorkshire.

A survey of attitudes to psychosurgery among consultant psychiatrists in two regions of Britain was undertaken by a postal questionnaire. Most psychiatrists considered that there is still a role for psychosurgery in psychiatric practice and over 75 per cent of psychiatrists working in general adult psychiatry requested facilities for the referral of patients; the majority of those requesting preferred local facilities and thought that the psychosurgical team should carry out both the assessment and postoperative rehabilitation. Respondents to the questionnaire were conservative in their indications for considering psychosurgery. The effect that the revision of the Mental Health Act might have on psychosurgical practice was then considered and finally the organization of the authors' own practice is described.

Attitude of Health Personnel↗
PubMed1984

Optimization of assay conditions in monoclonal-based immunoradiometric assay.

The production of relatively large amounts of pure monoclonal antibodies (MAb) has facilitated the development of MAb-based immunometric assays for a variety of clinically important analytes. 'Two-site' heterogeneous assays are now available which incorporate a labelled MAb and a second, different MAb coupled to a solid support. These assays possess certain advantages over the corresponding immunoassays including speed, precision, working range and specificity. They are largely dependent on two specific molecular interactions (labelled MAb-antigen; antigen--solid support MAb) and thus one might expect them to be particularly sensitive to assay conditions. With reference to two MAb--based two-site immunoradiometric assays (for human growth hormone and prolactin) which are being developed in this laboratory we wish to report the effect of various conditions including pH, ionic strength, buffer species etc. on assay response in order to emphasize the need for careful optimisation of monoclonal antibody based assays.

Animals↗
PubMed1982

A convenient replacement for cyanogen bromide-activated solid phases in immunoradiometric assays.

Periodate oxidation of Sephacryl and Sephadex gels (Pharmacia) and the subsequent coupling of the IgG fraction from antisera has been investigated as a possible, more convenient system to replace the potentially hazardous cyanogen bromide activation of Sepharose which is currently used to produce solid-phase linked antibody for use in sandwich immunoradiometric assays (IRMA). A solid phase based on Sephacryl S300 was found to be a suitable replacement. Under optimum conditions of periodate oxidation and protein concentration during coupling a Sephacryl S300 solid-phase antibody was produced which, in an IRMA for human alphafetoprotein, behaved favourably in terms of high binding capacity and low non-specific binding. Both the final solid-phase preparation and the intermediate oxidised gel were stable for several weeks.

Acrylic Resins↗
PubMed1981

Nature and timing of some sporulation-specific protein changes in Saccharomyces cerevisiae.

During meiosis and spore formulation in Saccharomyces cerevisiae, changes that occur in a/alpha diploids, but not in isogenic nonsporulating a/a diploids, have been detected in cellular polypeptides. These were found by the technique of prelabeling growing cells with 35SO4(2-) and suspending them in sulfur-free sporulation medium. Under the conditions used, about 400 polypeptides were detected by two-dimensional gel electrophoresis, and 45 were altered during sporulation; of these, 21 changes were specific to a/alpha strains. These alterations were mainly due to the appearance of new polypeptides or to marked increases in the concentrations of a few polypeptides produced during vegetative growth. They could have been due either to modifications of existing polypeptides present in growing cells or to de novo synthesis of new gene products. They occurred at characteristic times during sporulation; whereas the majority of changes took place early (within the first 6 h in sporulation conditions), there were several changes characterizing the later stages of sporulation. Ten of the 35SO4(2-)-labeled polypeptides were also labeled with 32P in the presence of [32P]orthophosphate; of these, three were previously found to be sporulation specific. One of these was phosphorylated at all stages of sporulation and was labeled when [32P]orthophosphate was added either during growth of the culture of 1 h after transfer to sporulation medium. Another was labeled in the same way by adding 32P at either time, so that by 7 h in sporulation medium it was phosphorylated, but was dephosphorylated by 24 h. The third sporulation-specific peptide was labeled in extracts prepared at 7 h in sporulation medium (but not at 24 h) when [32P]-orthophosphate was added during presporulation growth, but not when [32P]-orthophosphate was added 1 h after transfer of the culture to sporulation medium. This polypeptide appeared early during sporulation; it is probably phosphorylated as it appears and is dephosphorylated at some time between 7 h and 24 h of sporulation.

Fungal Proteins↗
PubMed1977

A comparison of cAMP phosphodiesterases in normal, malignant, and somatic cell hybrids.

Hybrids (PCM) between a malignant mouse lymphoma suspension cell line (P388F-36) and a normal Chinese hamster fibroblastic cell line (Ch23) have already been isolated in this laboratory. Investigations were carried out on the cAMP phospodiesterases of the parents and two of these hybrids--PCM2 and PCM3. PCM3 shows a rather unusual growth characteristic in that a considerable proportion of the cells exist at any one time either in suspension or only loosely attached to the substratum, the remaining cell population existing in a monolayer form. It was found that each cell line exhibited multiple forms of the enzyme with varying affinities for cAMP. Both parents, although different, contained high-, low-, and extra-high apparent Km forms of the enzyme. The hybrids exhibited characteristics of both parental systems but were different from each other. Neither hybrid exhibited a high-Km enzyme, but both exhibited two low-Km forms. There was also a slight variation between monolayer and suspension cells of PCM3 hybrid. An attempt has been made to explain these phenomena with respect to hybridization and the growth characteristics of the cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1975

Neoplastic and life-span effects of chronic exposure to tritium. II. Rats exposed in utero.

A study was conducted to determine the effects on neoplasia incidence and life-span of exposure in utero to a major environmental radionuclide. Sprague-Dawley rats were continuously exposed to tritiated water (HTO) from conception through birth in doses of 0, 1, 10, 50, and 100 muCi HTO/ml body water. HTO administration was terminated at birth. Calculated cumulative doses during gestation were approximately 0, 6.6, 66, 330, and 660 rads of total body irradiation. Under these exposure conditions, the two highest doses resulted in sterile offspring. Animals surviving through 30 days postnatally were defined as the study population and observed until their deaths. Intrauterine exposures to doses up to 66 rads had no significant effects on either sex with respect to life-span, overall neoplasia incidence, incidence rate, or onset of mammary fibroadenomas. Females exposed to 330 or 660 rads were sterile and had lower incidence rates of mammary fibroadenomass than did controls; at 660 rads females had a lower incidence of overall neoplasia and reduced mean life-spans. Sterile male offspring had reduced mean longevity after irradiation at 660 rads. Regardless of dose group, females had significantly higher incidences of neoplasia and longer life-spans than males.

Adenofibroma↗
PubMed1975

Neoplastic and life-span effects of chronic exposure to tritium. I. Effects on adult rats exposed during pregnancy.

Female Sprague-Dawley rats were continuously exposed to equilibrium levels of tritiated water (HTO) during pregnancy. The tritium activities were 1, 10, 50, and 100 muCi HTO/ml body water which provided cumulative, whole-body radiation doses of approximately 6.6, 66, 330, and 660 rads. Administration of the radioisotope was terminated at parturition. Throughout their life-spans and at autopsy, the dams showed an increased incidence of mammary fibroadenomas at exposure to 330 and 660 rads. Although the data for the incidence of malignant mammary neoplasms were consistent with a linear dose response, the small numbers of tumors preclude specific definition of the dose-response curve. Postexposure life-spans for dams chronically exposed to 66, 330, and 660 rads during pregnancy were reduced by 14, 24, and 22%, respectively. Accelerated aging was also demonstrated in these rats: The mean age for mammary fibroadenoma onset decreased with an increasing dose of radiation.

Adenofibroma↗