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Biomedical subjects

P Jackson

Publications and source records attributed to P Jackson.

At least 91 records · Page 5Linked to original sources
PubMed1996

A study of Technegas employing X-ray photoelectron spectroscopy, scanning transmission electron microscopy and wet-chemical methods.

Scanning transmission electron microscopy (STEM), coupled with energy dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS) or radionuclear chemical methods, indicates that the active agent in Technegas is either polymeric TcO2[i.e. (TcO2)n] or (TcO2)n bound to a carbon nanoparticle. The particle size observed using STEM is in good agreement with other published results. XPS has also been used to investigate technetium residues remaining on spent crucibles. The chemical form of technetium in this residue is quite different to the form detected in the aerosol particles. We conclude that the small fraction that migrates into the crucible framework upon resistive heating is reduced to either metallic technetium or carbidic forms, with the remaining nuclide evaporating as (TcO2)n with or without carbon before complete reduction can occur.

Chemistry↗
PubMed1996

Human recombinant antibodies specific for hepatitis C virus core and envelope E2 peptides from an immune phage display library.

Hepatitis C virus (HCV) is the aetiological agent responsible for most cases of non-A non-B hepatitis. Hepatitis C is a disease of clinical importance because of its high infection rate in blood donors and its persistence as chronic infections which may lead to cirrhosis and hepatocellular carcinoma in the long term. The variability of the HCV genome has posed difficulties in serological detection and vaccine design. The recent advance in phage technology offers a means of cloning human anti-HCV antibodies of a defined specificity that may have potential therapeutic use. We now report the generation of a phage display library using the V(H) genes of a HCV-infected patient and the V(L) genes of two non-immune individuals. From this library we were able to obtain specific IgG single-chain Fvs (scFvs) that recognize viral core and envelope proteins by selection on synthetic peptides derived from the core sequence PKARRPEGRTWAQPG and the envelope E2 sequence RPIDDFDQGWGPITY. The specificity of the scFvs was demonstrated by their specific reactions with homologous peptides in ELISA and the specific blocking of scFv binding by homologous peptides, in a dose-dependent manner, in inhibition ELISA. The binding of the anticore 4c2 to homologous peptide was blocked by HCV-positive human sera in an antibody-concentration-dependent manner, suggesting that the scFv recognizes a similar if not identical epitope to those of one or more of the polyclonal antibodies present in the sera.

Amino Acid Sequence↗
PubMed1996

Statutory and voluntary sector palliative care in the community setting: National Health Service professionals' perceptions of the interface.

Following the rapid service development brought about by the hospice movement, specialist palliative care services are involved with up to 50% of all patients dying with cancer in the United Kingdom, although the primary health care team remains the main provider of community based palliative care. This paper discusses findings from a survey of palliative care provision in the south west of England, and describes the perceptions of the primary care team (general practitioners and district nurses) about the interface between themselves and voluntary sector specialist palliative care providers (hospice in-patient units, hospice home care nurses and other charitably funded specialist palliative care nurses). The voluntary sector services are run with a mixture of funding from charitable sources (public donations, legacies, charitable trust moneys), and statutory funding (grants and recurrent contracts from central government, district health commissions, and local health care trust). The interview and questionnaire data suggest that the voluntary sector services are perceived variably as substituting, supplementing, complementing and duplicating the services provided by the primary care team. Drawing attention to these dimensions and the ambivalence sometimes felt by general practitioners and district nurses could provide a means of negotiating consensus on appropriate professional tasks and facilitating interprofessional practice in what is increasingly a mixed economy of statutory and voluntary funded health care.

Attitude of Health Personnel↗
PubMed1996

Antidepressants and drug-metabolizing enzymes--expert group report.

Antidepressant drugs are extensively metabolized. Consequently, the biotransformation pattern of antidepressants has an important influence on their clinical properties, i.e., pharmacokinetics, toxicity, drug-drug interactions, side-effect profile and last but not least therapeutic efficacy. It was against this background that a multidisciplinary group of experts discussed the clinical relevance of the rapidly increasing body of knowledge of antidepressant-metabolizing enzymes. The variability of the response of a given individual to an antidepressant is determined genetically and by the environment. Genetic polymorphism of drug-metabolizing enzymes and inhibition by other substrates may affect the enzymatic biotransformation of antidepressants. In vitro assay techniques allow an estimation of the potential variability in clinical response to antidepressants and a reasonable prediction of the drug-drug interaction patterns. The results of in vitro tests should therefore be considered early in the development of an antidepressant as a background for designing clinical studies (treatment schedules and dosing). Physicians should have an understanding of the relevance of genetic polymorphism for clinical practice. Education is needed in order to fill the existing gaps in knowledge about antidepressant-enzyme interactions and their application in daily treatment practice. The information on potential drug interactions determined by genetic polymorphism and based on studies with enzymes should be increasingly contained in drug compendia.

Antidepressive Agents↗
PubMed1995

Quantitative electroencephalographic analyses in cocaine-preferring polysubstance abusers during abstinence.

Quantitative electroencephalographic (QEEG) analyses are presented for a group of 90 subjects recovering from polysubstance abuse (median = 90 days abstinent) who preferentially used cocaine. QEEGs showed significant decreases from normal in both absolute and relative delta power and decreased theta power in both absolute and relative power. Significantly increased relative but not absolute alpha and beta power was found. Asymmetry of frontal delta, theta, and alpha power differed from normal with right power greater than left. Globally, reduced interhemispheric coherence was found in delta and theta bands and frontally in the beta band. An atypical EEG pattern was observed in about half of the subjects. This was a paroxysmal-like EEG alpha pattern reminiscent of vertex waves typically associated with drowsiness but lacking the waxing and waning of alpha and the slow lateral eye drift associated with drowsiness.

Adult↗
PubMed1995

p53 represses SV40 transcription by preventing formation of transcription complexes.

There is now much evidence to suggest that the p53 tumour suppressor protein functions to monitor the integrity of the genome. When DNA damage is detected, p53 suppresses cell growth to allow repair or directs the cell into apoptosis. The mechanism of action of p53 is as yet unclear but recent evidence has accumulated to suggest that p53 might act by regulating gene expression. Consistent with this model, p53 can both activate and repress a number of viral and cellular promoters. p53 has also been shown to bind to the CCAAT-binding Factor and TATA-binding protein (TBP), and there is direct evidence that p53 represses in vitro transcription by preventing TBP from binding DNA. We now provide evidence that p53 can repress transcription from the SV40 promoter by disrupting DNA/protein complexes involving transcription factor Sp1.

Animals↗
PubMed1995

Total mesorectal excision and local recurrence: a study of tumour spread in the mesorectum distal to rectal cancer.

Total mesorectal excision (TME) appears to be associated with a reduced local recurrence rate following surgery for rectal cancer. Of 20 patients with rectal cancer in whom TME was performed, adenocarcinoma was found in the distal mesorectum in four. Distal mesorectal spread often extended further than intramural spread. Patients with tumour in the distal mesorectum had a worse outcome at 4-year follow-up, a greater risk of local recurrence and an increased frequency of distant metastasis. Distal tumour spread is, therefore, a marker of poor prognosis in rectal cancer. This study provides further evidence that incomplete excision of the mesorectum contributes to local recurrence in a proportion of patients with rectal cancer, particularly in those with tumours in the middle and lower third of the rectum.

Adenocarcinoma↗
PubMed1995

(Re)theorising population geography.

"Population geography has become separated from other branches of human geography by not engaging strongly with recent debates in social theory. The reasons for this partly lie in the wealth of data that population geographers have available to them concerning their major interest--demographic events....A case is made here for population geographers to consider in particular three areas of social theoretic debate--social construction theories, realist ideas on extensive and intensive research, and the politics of position. Suggestions are made as to what a (re)theorised population geography might look like."

Demography↗
PubMed1995

Processes of persuasion: social interests and total quality in a UK hospital trust.

This paper examines some of the processes which have contributed to the development of a 'total quality' (TQ) approach within British health care. The paper challenges the idea that TQ is part of a redistribution of power within the NHS. Rather it is argued that through the elaboration of consumer-led market identities TQ misrepresents the interests of management and constructs a version of the self which obscures new forms of managerial control. TQ constrains alternative forms of social organisation, local knowledge and the social interests invested in them. An example of a competing set of assumptions is discussed. It is suggested that clinical groups--who are primarily motivated by the principles of professional, collegiate control--seek to free themselves from the constraints of TQ. Thus clinical discourse appropriates a professionally led version of the market and protects the traditional autonomy of professionals whilst seeming to render their interests synergistic with those of management. This casts 'quality', and perhaps even the 'market', as conceptual sites upon which different groups strive to construct and legitimate their own interests. It is concluded that the changes explicitly associated with TQ are not as fundamental as they seem.

Data Collection↗
PubMed1995

Difference in prevalence of gestational diabetes and perinatal outcome in an innercity multiethnic London population.

In order to establish the prevalence of gestational diabetes mellitus (GDM) among ethnic groups residing in the catchment area of one hospital in central London and to assess both the mode of delivery and the baby outcome, we studied retrospectively 703 women selected for screening for GDM during the years 1991 and 1992. While the prevalence of GDM was approximately 2% overall, within the ethnic groups a significant difference was found with Asians and Africans/Afrocaribbeans being four and two times more likely to have GDM, respectively, than Caucasians (P < 0.001). Both maternal obesity and the diagnosis of GDM influenced the time and the mode of delivery, but perinatal mortality and morbidity did not differ significantly between women with GDM and women with normal glucose tolerance. An association between the GTT glucose area and the gestational age and ethnicity adjusted birth weight was observed in women with normal glucose tolerance test, but was absent in the GDM pregnancies, providing indirect evidence that dietary treatment, with or without insulin treatment, altered the maternal milieu in the latter sufficiently to modify fetal growth.

Adult↗
PubMed1995

Cytogenetic findings in a case of nodular fasciitis of the breast.

We report the cytogenetic findings in a case of nodular fasciitis of the breast. The abnormalities found in all 11 metaphases available for analysis were -2, -2, -13, der(15)t(2;15)(q31;q26), + der(?) t(?;2), + mar1, + mar2. Other consistent abnormalities were also identified. Fluorescence in situ hybridization (FISH) was used to confirm the origin of some of the chromosomes. A large acrocentric chromosome was confirmed to be derived from chromosome 15 with chromosome 2 material translocated onto the q arm. The metacentric der(?)t(?;2) was demonstrated to have part of chromosome 2 on the q arm. No other chromosome 2 material was found. Eight of 11 cells were tetraploid and had two copies of a del(6)(q16q24).

Aged↗
PubMed1995

Clinical results from intracytoplasmic sperm injection at monash IVF.

The impact of a modification of the intracytoplasmic sperm injection (ICSI) technique on fertilization and pregnancy rates was examined in a retrospective analysis of 171 consecutive ICSI treatment cycles (156 patients). Patients were selected for ICSI on the basis of severe oligoasthenozoospermia (65 patients) or following conventional in vitro fertilization (IVF) with failed or poor fertilization (70 patients). Seven patients in which epididymal or testicular sperm was used, 10 patients with sperm antibodies and 4 patients with retrograde ejaculation or who required electro-ejaculation were also treated with ICSI. In the first 105 cycles (102 patients), single sperm, rendered immotile, were injected into the ooplasm of 979 metaphase II (M II) oocytes using an established technique (Method 1). In the following 66 cycles (513 M II oocytes injected), the ICSI procedure was modified by increased aspiration of the oolemma to ensure the intracytoplasmic deposition of sperm (Method 2). The patient groups did not differ between the two injection procedures. The normal (two pronuclear) fertilization rate increased significantly (P < 0.001) from 34.3% with Method 1 to 73.1% with Method 2, with no difference in the oocyte degeneration rate (4.3% v. 4.5% respectively). The incidence of failed fertilization was significantly (P < 0.01) reduced from 17.1% (18 cycles) to 1.6% (1 cycle) with the change in technique. As a consequence of the increased fertilization rates with Method 2, more embryos were available for assessment and transfer, and a pregnancy rate per oocyte retrieval of 21.2% was obtained for Method 2. Fertilization, embryo transfer and pregnancies were obtained in all patient groups treated with ICSI.(ABSTRACT TRUNCATED AT 250 WORDS)

Australia↗
PubMed1995

Early detection and treatment of myocardial ischaemia after operation using continual ambulatory arterial pressure monitoring and ECG ST segment analysis.

We report a case in which the use of continual ambulatory arterial pressure monitoring and ECG ST-segment analysis allowed early detection and treatment of myocardial ischaemia in the postoperative period. We believe that this case illustrates the potential value of ambulatory monitoring in the early postoperative period in high-risk patients.

Blood Pressure Monitoring, Ambulatory↗
PubMed1995

von Willebrand factor, a possible indicator of endothelial cell damage, decreases during long-term compliance with a lipid-lowering diet.

OBJECTIVES: To test whether serum von Willebrand factor (vWf) would be lower in men with atherosclerosis who had been consuming a lipid-lowering diet for 3 years than in a control group of men with atherosclerosis who had been following their normal diet. DESIGN: A randomized, population-based case-control study. SETTING: A tertiary health care referral centre at a University Hospital. SUBJECTS: Men age less than 66 years with angiographically proven coronary atherosclerosis and a cholesterol level > 6 mmol L-1. Sixty started the study and 50 completed it. INTERVENTIONS: Subjects were randomized to a lipid-lowering diet or to taking their normal diet for approximately 3 years. MAIN OUTCOME MEASURES: The components of the subjects' diets were assessed and blood was obtained for total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, triglycerides and for vWf. RESULTS: Men on the lipid-lowering diet consumed less total, saturated and monounsaturated fats (all P < 0.001), cholesterol and retinol (both P < 0.002) but increased polyunsaturated fats (P < 0.001), fibre, vitamin E (both P < 0.005) and carbohydrate (P < 0.05). Those on the lipid-lowering diet also had lower serum levels of total and LDL cholesterol (P < 0.002 and P < 0.05, respectively), triglycerides (P < 0.02) and vWf (P < 0.05) than the men on their normal diet. There was no difference in HDL cholesterol. Levels of vWf correlated with both total cholesterol (P < 0.005) and inversely with dietary polyunsaturated fats (P < 0.02). CONCLUSION: von Willebrand factor, a possible indicator of endothelial cell damage, decreases during long-term compliance with a lipid-lowering diet.

Adult↗