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Biomedical subjects

S E Taylor

Publications and source records attributed to S E Taylor.

At least 73 records · Page 4Linked to original sources
PubMed1995

Depletion of alpha-tocopherol in human atherosclerotic lesions.

Estimations of alpha-tocopherol content were made on a series of human necropsy samples of normal arterial wall and of atherosclerotic lesions. The results were compared with stage of lesion, shown by histology, and with the amounts of cholesterol and hydroxycholesterols in the same lesions. The ratio of alpha-tocopherol to cholesterol levels varied widely in normal arterial wall but was consistently low in lesions, especially in lesions rich in macrophage foam cells. The results suggested that significant accumulation of hydroxycholesterols, found almost exclusively in lesions, only occurred when alpha-tocopherol levels were low in relation to the cholesterol content. This suggests that oxidative activity in the lesion may lead to significant oxidation of constituents of low-density lipoprotein only after alpha-tocopherol has been depleted.

Adolescent↗
PubMed1995

New approaches to targeting arthritis with radiopharmaceuticals.

Though emission imaging techniques have been a major clinical tool for imaging osteoblastic activity and tumor involvement of the bony skeleton for over 20 years, radiolabelled probes specific for pathophysiology of synovium and articular cartilage are just beginning to be explored. Recent success with 99mTc labelled IgG, 18F-fluorodeoxyglucose, and antibodies to E-secretin encourage development of specific probes. The technology for radiolabelling peptide probes such as Mab and Fab with both positron emitters and conventional single photon emitters, the most recent concepts of labelling ssDNA aptamers specific for targeted proteins associated with diseases of the synovium and cartilage, and the availability of probes for substance P and porphyrin avid tissues has opened new horizons for studying the early onset of arthritis and therapeutic response to new forms of therapy.

Arthritis↗
PubMed1994

Production of oxidized lipids during modification of low-density lipoprotein by macrophages or copper.

The oxidation of low-density lipoprotein (LDL) is implicated in atherosclerosis. Lipids and oxidized lipids were analysed by gas chromatography and gas chromatography-mass spectrometry in human LDL incubated with mouse peritoneal macrophages (MPM) or copper (II) sulphate in Ham's F-10 medium or medium alone (control). MPM-modification and copper-catalysed oxidation of LDL resulted in the formation of oxysterols, mainly cholest-5-en-3 beta,7 beta-diol (7 beta-OH-CHOL); 7%-19% of the initial cholesterol was converted to 7 beta-OH-CHOL in 24 h. 7 beta-OH-CHOL levels in control LDL were very low. The increase in 7 beta-OH-CHOL in MPM and copper-oxidized LDL was accompanied by decreases in linoleate and arachidonate and increases in the electrophoretic mobility and degradation of LDL protein by 'target' macrophages. The concerted occurrence of these processes and their similarity in both MPM-modification and copper-catalysed oxidation of LDL were suggested by the highly significant cross-correlations. The fall in polyunsaturated fatty acid (PUFA) was accompanied by a directly proportional increase in electrophoretic mobility of the LDL. Production of 7 beta-OH-CHOL and protein degradation by macrophages showed modest elevations during the initial steep fall in PUFA, and showed their greatest increases as the levels of PUFA slowly approached zero. The levels of 7 beta-OH-CHOL and the degradation of LDL by macrophages were directly proportional. The degradation of LDL by macrophages increased rapidly as the electrophoretic mobility of LDL was slowly approaching its maximum level.

Animals↗
PubMed1994

G-protein- and capacitatively regulated Ca2+ entry pathways are activated by muscarinic receptor stimulation in a human submandibular ductal cell line.

In the human submandibular ductal cell line (HSG) thapsigargin and carbachol stimulated Ca2+ release from the internal Ca2+ pool, resulting in the activation of capacitatively regulated Ca2+ entry (CRCE). This entry pathway was permeant to both Ca2+ and Mn2+, blocked by Ni2+ and insensitive to the muscarinic antagonist, atropine. Carbachol also stimulated an increase in cytosolic [Ca2+] in internal Ca(2+)-pool-depleted (i.e. thapsigargin-treated) cells which was dependent on the presence of external Ca2+ and blocked by Ni2+, demonstrating that it was due to Ca2+ entry. However, under the same experimental conditions, carbachol was unable to stimulate Mn2+ entry. Additionally, this latter carbachol-stimulated Ca2+ entry pathway was blocked by atropine. Pretreatment of HSG cells with AlF4-increased basal rates of Mn2+ entry due to CRCE activation, but attenuated carbachol-stimulated Ca2+ entry into thapsigargin-treated cells. The data suggest that two distinct divalent cation entry pathways are activated in muscarinic-receptor-stimulated HSG cells; a CRCE mechanism, permeable to both Mn2+ and Ca2+, and a second entry mechanism, permeable only to Ca2+. The latter does not depend on internal pool depletion, but appears to be regulated via G-protein activation.

Aluminum Compounds↗
PubMed1994

Repeated bereavement, depressed mood, and immune parameters in HIV seropositive and seronegative gay men.

The relationships among bereavement, depressed mood, and immunologic patterns prognostic for the development of acquired immunodeficiency syndrome (AIDS) were determined in a sample of human immunodeficiency virus (HIV) seropositive gay men and a comparison group of HIV seronegative gay men. Immunologic parameters were assessed in 45 men who had recently experienced the deaths of close friends and 45 matched nonbereaved men. No immune differences were found between bereaved and nonbereaved men. Among the HIV seropositive nonbereaved men, higher depressed mood was significantly associated with fewer CD4 (helper/inducer) T lymphocytes, more activated CD8 (suppressor/cytotoxic) T cells, and lower proliferative responses to the mitogen phytohemagglutinin. In summary, HIV seropositive men who reported higher levels of depressed mood not associated with bereavement demonstrated immunologic patterns consistent with HIV activity and progression.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Realistic acceptance as a predictor of decreased survival time in gay men with AIDS.

Although theoretical accounts of adaptation in the terminally ill suggest that realistic acceptance of one's disease is adaptive, some investigations suggest that such responses are associated with increased mortality. This prospective psychobiological investigation involved 74 gay men with AIDS. Six scores reflecting responses to disease were derived from a detailed psychosocial questionnaire. One pattern of response, Realistic Acceptance, was a significant predictor of decreased survival time. Median estimated survival time for participants with low Realistic Acceptance scores was 9 months greater than for participants with high Realistic Acceptance scores. This effect was not accounted for by time since diagnosis with AIDS, self-reported health status, number of CD4 T lymphocyte cells, psychological distress, age, education, initial diagnosing condition, use of AZT, smoking, or alcohol and drug use.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Positive illusions and well-being revisited: separating fact from fiction.

In 1988, we published an article that challenged the notion that accurate perceptions of self and the world are essential for mental health (Taylor & Brown, 1988). We argued instead that people's perceptions in these domains are positively biased and that these positive illusions promote psychological well-being. In the current article, we review our theoretical model, correct certain misconceptions in its empirical application, and address the criticisms made by Colvin and Block.

Humans↗
PubMed1994

Binding potency of 6-nitroquipazine analogues for the 5-hydroxytryptamine reuptake complex.

The in-vitro inhibition constants (Ki) of nine structural analogues of the potent 5-hydroxytryptamine (5-HT)-uptake inhibitor, 6-nitroquipazine, were determined to assess the structure-affinity relationship of these derivatives. The goal of these studies was to determine those positions on 6-nitroquipazine that could be derivatized without significantly decreasing the affinity of the drug for the binding site, so that radiolabels such as 123I, 76Br or 18F might be appended for in-vivo imaging studies of the 5-HT reuptake system. Using bromine as a steric probe, the rank order of potency of bromine-substituted 6-nitroquipazine analogues for inhibiting the binding of [3H]paroxetine to the 5-HT reuptake binding site was: 8- < 3- < 7- < 4- < 5-bromo. The in-vitro equipotent molar ratio (EPMR, Ki (analogue)/Ki(6-nitroquipazine)) of the 5-bromo analogue was 0.57, indicating that this analogue had greater affinity for the 5-HT reuptake complex than 6-nitroquipazine. Derivatization at the 5-position with fluorine and iodine also resulted in potent compounds with EPMR values of 1.1 and 0.83, respectively. Substitution of quipazine with bromo, cyano, and formyl groups at the 6-position produced less potent compounds than the 6-nitro group. Based upon the high affinities of the 5-bromo-, 5-fluoro- and 5-iodo-6-nitroquipazines for the 5-HT reuptake complex, these compounds are candidates for radiolabeling for in-vivo studies of the 5-HT reuptake site.

Animals↗
PubMed1994

Ethnographic approach to community organization and health empowerment.

The purpose of this article is to address pertinent issues relative to the association between community organization and health empowerment methods in ethnic communities of colour. It seeks to address these issues by utilizing ethnographic procedures for documenting community health concerns and by advocating for empowerment for people of colour and their participation in coalition partnerships. Increasingly the importance of citizen participation in the planning, assessment, and implementation of community-based health initiatives has been identified as essential for effective health promotion and disease prevention programs. This article argues for the utility of a community organization approach for achieving health empowerment, and subsequently decreasing the excess deaths in communities of colour. The interface of ethnographic procedures, community organization, and development of community-owned action plans for programming health interventions is discussed.

Black or African American↗
PubMed1994

Is cardiopulmonary resuscitation training deleterious for family members of cardiac patients?

The purpose of the study was to determine the attitudes toward cardiopulmonary resuscitation (CPR) training and subsequent CPR use of 172 CPR-trained family members of cardiac patients. The majority (88.9%) reported positive attitudes. Only 14 (8.1%) reported feeling too responsible for their family member. One hundred and forty-one (81.9%) said that they would perform CPR if required to do so. Family members do not feel unduly burdened by learning CPR, and CPR training should be recommended to families of patients at risk for sudden cardiac death.

Adult↗
PubMed1994

Differing effects of probucol and vitamin E on the oxidation of lipoproteins, ceroid accumulation and protein uptake by macrophages.

Studies using 125I-low density lipoprotein (125I-LDL) show that probucol (10 microM) and alpha-tocopherol (100 microM) inhibit protein degradation in LDL exposed to Cu (II) in vitro. The inhibitory effect of alpha-tocopherol on protein fragmentation exceeded that of probucol. On the other hand, probucol was more able to inhibit lipid peroxidation. The subsequent uptake of Cu (II)-oxidised 125I-LDL by murine peritoneal macrophages (MPM) was virtually unaffected by the presence of probucol during LDL oxidation. The same was not true for alpha-tocopherol which led to lower levels of 125I-LDL uptake by MPM. Thus, it appears that although the antioxidant activity of probucol exceeds that of alpha-tocopherol for lipid oxidation, the reverse is true for protein degradation and, perhaps more significantly, for subsequent macrophage uptake. Further studies used artificial lipoproteins composed of cholesteryl linoleate or cholesteryl arachidonate complexed with bovine serum albumin. Culture of these artificial lipoproteins with MPM resulted in protein uptake, protein degradation, cholesterol oxidation to cholest-5-en-3 beta,7 beta-diol and the intracellular accumulation of ceroid in MPM. The presence of alpha-tocopherol (0-100 microM) inhibited all of these processes. Probucol (0-10 microM) inhibited ceroid accumulation and cholesterol oxidation to the same degree as alpha-tocopherol (0-100 microM) but had no effect upon protein degradation and protein uptake. Control studies of lipoproteins incubated without cells showed that protein degradation by cell-independent processes was also inhibited by alpha-tocopherol, but not by probucol. These observations are discussed in the context of the role of lipoprotein oxidation in atherogenesis.

Animals↗
PubMed1994

Pharmacologic considerations in the management of oral surgery patients in general dental practice.

Minor oral surgery is an integral part of dentistry, whether performed by the generalist or the specialist. Procedures include those within the broad discipline of general oral surgery (such as routine and surgical extractions, impactions, preprosthetics, biopsy, and implants), periodontics (such as periodontal surgery, mucogingival plastic surgery, and implants), and endodontics (periapical surgery). There is considerable overlap among generalists and surgical specialists in terms of the treatment provider. Perhaps the most important consideration with regard to appropriateness and quality of care is not who does the surgery but how it is done. The ability to perform surgery according to sound surgical principles and to properly prescribe medications in association with that surgery is a necessary requisite for quality treatment. This article reviewed how various pharmacologic agents can be administered and how they influence surgical procedures. Whether or not they are used and the manner in which they are used are predicated on the discretion and clinical judgment of the clinician on a case-by-case basis. If used appropriately, these medications can be instrumental in mitigating morbidity and increasing tolerance and overall patient satisfaction with the surgical experience.

Analgesia↗
PubMed1993

[125I]5-iodo-6-nitroquipazine: a potent and selective ligand for the 5-hydroxytryptamine uptake complex. I. In vitro studies.

In search of a potent and selective radioiodinated ligand for the 5-hydroxytryptamine (serotonin or 5-HT) uptake complex, we synthesized and evaluated the in vitro properties of [125I]5-iodo-6-nitroquipazine. The binding properties and pharmacological profile of this radioligand were studied in rat brain homogenates, and it was found to display high affinity and selectivity for the serotonin uptake complex. Scatchard analysis of the binding data indicated a single population of sites with a Kd of 23 +/- 6 pM and a Bmax of 430 +/- 50 fmol/mg protein (mean +/- S.E.M., n = 7). Inhibitors of serotonin uptake were the most efficient competitors for [125I]5-iodo-6-nitroquipazine binding with Ki values similar in rank order and magnitude to those obtained in studies of other established serotonin uptake blockers. Inhibitors of dopamine and norepinephrine uptake as well as a wide variety of postsynaptic receptor agents were relatively ineffective in inhibiting [125I]5-iodo-6-nitroquipazine binding to rat brain membranes. Serotonin was the only monoaminergic neurotransmitter capable of effectively competing for [125I]5-iodo-6-nitroquipazine binding sites and gave a Ki value of 2.8 +/- 0.6 microM. Lesions of the serotonergic system with p-chloroamphetamine resulted in a dramatic loss (> 90%) of [125I]5-iodo-6-nitroquipazine binding to rat cortical membranes. Non-radiolabeled 5-iodo-6-nitroquipazine potently inhibited the binding of [3H]paroxetine to serotonin reuptake sites in rat cortical membranes with a Ki of 0.17 +/- 0.06 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Lipids and oxidised lipids in human atheroma and normal aorta.

Lipids and oxidised lipids were analysed by GC and GC-MS in samples of human atheroma (necrotic gruel from the interior of advanced atherosclerotic plaques in the aorta) and human normal aorta (lesion-free intima plus inner media) from necropsy subjects. Cholest-5-en-3 beta,26-diol and cholest-5-en-3 beta,7 beta-diol were detected in all the atheroma samples examined but not in significant amounts in normal aorta. In atheroma, cholest-5-en-3 beta,26-diol was approximately proportional to cholesterol. Several isomeric hydroxy-octadecadienoic acids were detected in atheroma, and, in smaller amounts, in normal aorta. Many of the components of atheroma showed a high degree of cross-correlation on linear regression analysis, whilst cross-correlations were somewhat weaker for normal aorta. Atheroma showed a vast accumulation of lipid, especially cholesterol, in comparison to normal aorta. The atheroma samples contained a larger proportion of linoleate relative to oleate than the normal aorta. Levels of fatty acids relative to cholesterol were lower for atheroma than for normal aorta. The chemical composition of atheroma appeared unrelated to the age of the subject, whereas age-related increases in linoleate, oleate and cholesterol content were seen in the samples of normal aorta.

Age Factors↗
PubMed1993

Effects of social comparison direction, threat, and self-esteem on affect, self-evaluation, and expected success.

Two studies explored the conditions under which social comparisons are used to manage negative affect and naturalistic threats. Study 1 examined induced mood and dispositional self-esteem as determinants of affective responses to upward and downward comparisons. Consistent with a mood repair prediction, only low-self-esteem Ss in whom a negative mood had been induced reported improved mood after exposure to downward comparison information. Study 2 examined the impact of naturalistic threats on responses to comparison information. Relative to a no-comparison baseline, low-self-esteem Ss who had experienced a recent academic setback reported more favorable self-evaluations and greater expectations of future success in college after exposure to downward comparison information. These results remained significant after controlling statistically for general distress. Implications for downward comparison theory are discussed.

Adaptation, Psychological↗
PubMed1993

Dementia: physician approaches to the caregiver's problems.

The demented patient requires medical and often psychiatric supervision, but the caregiver is often neglected. This article identifies special issues for caregivers that may need attention from the demented patient's physician. The physician's attention can benefit both the patient and the caregiver and save the physician valuable time.

Activities of Daily Living↗
PubMed1992

Tracer kinetic evidence for abnormal methyl metabolism in schizophrenia.

The original transmethylation hypothesis of schizophrenia has evolved with time and experiment to the present concept that a defect in the methyl-carbon metabolic pathway may be causative in this illness. Various researchers have proposed that specific steps in the methyl-carbon pathway may be defective, and have presented evidence to support these possibilities. We have tested the general concept of the hypothesis by administering methionine labeled with 11C or 14C in the S-methyl carbon to patients with schizophrenia and to controls and measured the expiration of 11CO2 and 14CO2. We found that the rate and total expiration of labeled CO2 were three times less in the patients than in the controls, with no overlap of data points in the two groups. Specific steps in the methylcarbon pathway that might be defective and produce the results seen here are discussed in light of this and other researchers' findings.

Adult↗