Search PubMed⌕ Search

Biomedical subjects

P Jackson

Publications and source records attributed to P Jackson.

At least 181 records · Page 10Linked to original sources
PubMed1988

Effective lipid lowering diets including lean meat.

The plasma lipid and lipoprotein responses to two modified isoenergetic diets including meat were studied in 15 free living men with hyperlipidaemia (mean plasma cholesterol and triglyceride concentrations 8.1 and 3.4 mmol/l). A reference diet (diet A, 42% energy from fat, ratio of polyunsaturated to saturated fatty acids (P:S ratio) 0.2) was compared with a fat reduced diet (diet B, 35% energy from fat, P:S ratio 0.5) and with a further fat modified diet supplemented with fibre (diet C, 27% energy from fat, P:S ratio 1.0). Daily intake of meat and meat products (180 g/day) was the same in each dietary period; that in diet A had a fat content typical of the average British diet, whereas that in diets B and C was based on very lean meat and meat products. During consumption of diet B the plasma cholesterol concentration fell by 8.6% and low density lipoprotein cholesterol by 11%. During consumption of diet C plasma cholesterol fell by 18.5% and low density lipoprotein cholesterol by 23.8%. Triglyceride and high density lipoprotein cholesterol concentrations and body weight did not change appreciably during the study. A modified diet including a moderate amount of lean meat and meat products is compatible with a reduced lipoprotein mediated risk of atherosclerotic heart disease.

Cholesterol↗
PubMed1988

Rapid imaging, using a cooled charge-coupled-device, of fluorescent two-dimensional polyacrylamide gels produced by labelling proteins in the first-dimensional isoelectric focusing gel with the fluorophore 2-methoxy-2,4-diphenyl-3(2H)furanone.

A new method for visualising proteins in two-dimensional polyacrylamide gels was developed. Proteins were labelled with the fluorophore 2-methoxy-2,4-diphenyl-3(2H)furanone (MDPF) while present in the first-dimensional gel after isoelectric focusing and subsequently electrophoresed into the second-dimensional gel. High resolution spot patterns were produced and compared with other methods of visualisation. A new rapid imaging system based on a cooled charge-coupled-device was used to view the two-dimensional fluorescent protein spot patterns. The method allows the immediate and rapid imaging of two-dimensional gels at the end of electrophoresis with no further processing.

Bacterial Proteins↗
PubMed1988

Endotoxins in culture medium for human in vitro fertilization.

Endotoxins were detected in a few batches of culture medium during the authors' human in vitro fertilization program. Two distinct levels of endotoxins were assayed: greater than 1 ng/ml and less than 1 ng/ml. The source of endotoxin was traced to culture media obtained from a reputable manufacturing company. The incidence of fertilization per patient was not significantly affected by the presence of endotoxins, but fertilization assessed on the overall number of oocytes was significantly reduced (53%) when endotoxin levels were greater than 1 ng/ml compared with an assay negative for endotoxins (66%) (P = 0.047). The percentage of oocytes cleaving after the observation of two pronuclei was not significantly different, but the degree of fragments observed in the conceptus was significantly more severe if the endotoxin level reached 1 ng/ml. In this investigation, the incidence of pregnancy was 8% when the endotoxin level was greater than 1 ng/ml, 30% if less than 1 ng/ml, and 32% if no endotoxins were detected. This study suggests that, although endotoxins may be present in the culture medium at a deleterious level of at least 1 ng/ml, fertilization and cleavage will be obtained, but there will be a significant increase in the incidence of conceptuses with cytoplasmic fragments; this may result in a reduction in the incidence of pregnancy.

Cells, Cultured↗
PubMed1987

Identification of oestrogen receptors in cells of paraffin-processed breast cancers by IGSS.

Oestrogen receptor (ER) analysis of breast cancers by the standard dextran coated charcoal (DCC) method and the oestrogen receptor immunocytochemical assay (ERICA), shows that ERICA is more sensitive. We find that the immunogold-silver staining technique (IGSS), which is used on paraffin sections, is applicable to the ERICA antibody and that the DCC and IGSS methods have comparable sensitivity. Reasons for wishing to develop an improved method for oestrogen receptor localisation in paraffin sections and its advantages are given.

Breast Neoplasms↗
PubMed1987

General anesthesia for intrauterine placement of human conceptuses after in vitro fertilization.

General anesthesia has been used for the replacement of human conceptuses after in vitro fertilization (IVF). Two adjuvants, enflurane and halothane, have been compared. Halothane significantly reduced the incidence of implantation compared to enflurane. In 356 replacements, the incidence of implantation for enflurane and halothane was 34 and 17%, respectively (P = 0.005). Sixty-four percent of all replacements had three conceptuses; the incidence of implantation for enflurane and halothane in this group was 43 and 19%, respectively (P = 0.002). The incidence of multiple pregnancy was similar for both anesthetic agents (20%) and the demise of implantation sacs 5 weeks postovulation was 11% for enflurane and 12% for halothane.

Adult↗
PubMed1987

Complement component deposition in uteroplacental (spiral) arteries in normal human pregnancy.

There is conflicting evidence for the deposition of complement in spiral arteries in normal and abnormal human pregnancies. The immunogold silver staining (IGSS) technique was used to investigate the distribution of C1q, C3d, C4, C6 and C9 within the spiral arteries of formalin-fixed normal pregnancy hysterectomy specimens ranging in gestational age from 4 to 40 weeks. Deposition of complement components studied was observed in all cases suggesting classical pathway activation. Reactivity was not confined to vessels showing endovascular trophoblast though the latter showed a characteristic linear deposition subjacent to the trophoblast. Reactivity was most intense for C3d and C9. An appreciation of complement deposition as a feature of normal pregnancy is essential before significant immunopathology can be recognised in placental bed vessels in abnormal pregnancy.

Antigen-Antibody Reactions↗
PubMed1987

Adapting to the unemployed role: a longitudinal investigation.

A sample of unemployed British men was interviewed for a third time after an average of 25 months continuous unemployment. As predicted, it was found that mental health, indexed in terms of affective well-being, had improved slightly since the previous interview. Adaptation of this kind was greater for men who had previously reported lower commitment to having a job and greater contact outside their immediate family, and also for those at the extremes of the age range. Measured availability of money and quality of social relationships were not related to adaptation. Changes in aspiration, autonomy and competence were considered likely to underpin the improvement in well-being. The need to study these additional components of mental health was emphasized, in order to determine when improvements in reported well-being should be considered 'healthy' or 'unhealthy'.

Adaptation, Psychological↗
PubMed1987

Genetic control of capsid length in bacteriophage T4: clustering of ptg mutations in gene 23.

Fifty-two new bacteriophage T4 ptg mutations have been isolated by selecting for the giant-capsid phenotype they display. Genetic mapping placed all of them at eight sites, all located in gene 23. These sites were clustered in three locations, one near amber B17 (gene 23 nucleotide [NT] 268), another centrally placed between amE506 (NT 706) and amE1270 (NT 925), and the third between amC208 (NT 1297) and amE1236 (NT 1489). The lack of a selective system for identifying recombinant genotypes when dealing with the very close linkages found within these clusters opens the possibility that more than eight sites are represented in this set of mutations. Since one site was represented by only one mutation, it seems likely that further searching might uncover additional sites. It is suggested that the clustering of mutations observed here identifies regions of the gene 23 product that play a role in regulating the capsid length of T4.

Base Sequence↗
PubMed1987

Fixation, processing, and immunochemical reagent effects on preservation of T-lymphocyte surface membrane antigens in paraffin-embedded tissue.

Fixatives, fixation additives, paraffin processing reagents, and immunochemical reagents were investigated for effects on preservation of T-lymphocyte surface membrane antigens CD3, CD4, and CD8 in human tonsil. Individual reagent effects were assessed in frozen sections by use of monoclonal antibodies and this information was used to optimize T-cell immunostaining in paraffin sections. Harmful factors were fixation delay, fixation at acid pH, fixation and processing at temperatures above 4 degrees C, hot paraffin wax, proteolytic enzymes, methanolic hydrogen peroxide, Triton X-100, and prolonged iodine treatment. Optimal T-cell demonstration in paraffin sections followed tissue fixation in periodate-lysine-paraformaldehyde dichromate at 4 degrees C, pH 7.5; processing through isopropanol, then xylene or chloroform, at 4 degrees C; and embedding in low melting point wax at 45-50 degrees C. Graded antigen stability occurred: CD3 most stable, CD8 least, and CD4 intermediate. CD4 and CD8 antigen preservation in paraffin sections required critical optimal tissue handling. CD3 was more stable and was also demonstrated in tissue fixed in commercial formalin, glutaraldehyde, and Bouin's fluid when fixation and processing conditions were optimized for pH and temperature. Of the fixation additives studied, polyethylene glycol and several potassium and magnesium salts enhanced immunostaining, whereas calcium chloride and lidocaine were deleterious.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Rethinking drug policies in the context of the acquired immunodeficiency syndrome.

This article presents a policy analysis of the needed responses to the problems associated with the acquired immunodeficiency syndrome and drug misuse that are now being experienced in the United Kingdom of Great Britain and Northern Ireland. Among the issues considered is the overall organizational and administrative capacity of a country to deal with a new acute demand and the probable need for more national centralization of planning and effort in the drug field. Policies must aim at small multiple gains rather than at master-strokes. International communication must be strengthened. The human immunodeficiency virus (HIV) epidemic requires re-examination of the penal handling of drug misusers. Treating more patients earlier may contribute significantly to prevention strategies, and methods for "harm reduction" deserve attention. Compulsory treatment or testing of HIV infection is not favoured. The importance of professional training and of research is stressed. Although the immediate focus is on one particular country's policy needs, the issues raised are of wider relevance.

Acquired Immunodeficiency Syndrome↗