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Biomedical subjects

C Mackay

Publications and source records attributed to C Mackay.

At least 19 recordsLinked to original sources
PubMed1995

Development of surrogate substrates for neuropathy target esterase.

Seventeen substrates were synthesized and their activities as surrogate substrates for Neuropathy Target Esterase were tested. Substrates investigated are carbon analogs of phenylvalerate (1) with oxygen and sulfur substituted at the alpha, beta and gamma positions. Phenol and thiophenol esters of these analogs constitute two series of compounds tested. The ratio of catalytic hydrolysis to background hydrolysis increased at lower pH values with all substrates tested including phenylvalerate (1). There was more than a 2.5-fold increase in specific activity with phenylthiopropylethanoate (6) at pH of 6.75 compared to phenylvalerate (1). Furthermore, a 19-fold decrease in Km is reported with compound 6. This and related compounds can be used as the basis of more sensitive assays for neuropathy target esterase. Thiophenyl esters in this series are sufficiently good substrates to hold promise in continuous assays.

Carboxylic Ester Hydrolases↗
PubMed1995

Lymphocyte migration. A new spin on lymphocyte homing.

New evidence confirms the multi-step model for leukocyte migration through endothelia, but with a twist. The selectins are not always required, and some lymphocyte subsets rely heavily on integrins for their migration to tissues.

Cell Adhesion↗
PubMed1994

Case report: rectal infarction after abdominal aortic surgery.

Full thickness ischaemic colitis complicates approximately 1-2% of abdominal aortic procedures. Ligation of the inferior mesenteric artery and hypotension are recognized as causative factors. It is not, however, widely appreciated that ischaemic proctitis may also rarely complicate aortic surgery, especially after complex procedures or if there has been additional interruption to the internal iliac circulation. We report a case of rectal necrosis following repair of a thrombosed aortic aneurysm in which plain X-ray appearances aided the diagnosis.

Aged↗
PubMed1993

[Occurrence of CD44 and its isoforms under orthological and pathological conditions].

Variant isoforms of CD44 have been strongly implicated in malignant transformation and cancer metastasis. To ascertain the pattern of expression of these isoforms in human normal, fetal and tumor tissues (breast carcinomas, renal cell carcinomas, malignant melanomas, colon carcinomas, non-Hodgkin-lymphomas, neuroblastomas and brain tumors), we generated monoclonal antibodies against CD44 variant regions. Monoclonal antibodies were produced against variant regions encoded by exons 4v, 6v and 9v. CD44 variant isoforms are expressed on normal epithelial cells in a different pattern. Regions of epithelia that expressed the highest levels of the variant isoforms were those with a high rate of cell division. CD44 variant isoforms were not expressed by all investigated tumors (not by malignant melanomas, brain tumors and neuroblastomas). It is interesting that the expression of CD44 isoforms in non-Hodgkins lymphomas and colon carcinomas shows possibly a correlation with malignancy.

Antibodies, Monoclonal↗
PubMed1992

Expression of human CD4 in transgenic mice does not confer sensitivity to human immunodeficiency virus infection.

Transfection of the human CD4 molecule into mouse cells does not confer susceptibility to human immunodeficiency virus type 1 (HIV-1) infection. Expression of the human CD4 molecule in transgenic mice was seen to offer some new possibilities. However, transgenic mouse T cells expressing either the human CD4 receptor, or a hybrid human/mouse CD4 receptor alone or in conjunction with human major histocompatibility complex class I molecules, were refractory to in vitro HIV-1 infection. In addition, no infection was observed after in vivo HIV inoculation to mice of these various transgenic lines. Injection of recombinant gp160 viral protein to the transgenic mice did not alter their T and B cell populations. The existence of a dominant block in mouse cells that prevents HIV entry is discussed.

Animals↗
PubMed1991

The use of the Roy Adaptation Model in nursing administration.

In recent years, considerable attention has been paid to the use of a nursing conceptual model for nursing practice. Although many of the theorists and early writers on the subject suggested that a nursing conceptual model could be used to guide nursing administration, there has been little attention given to this in the literature. This article describes the process that one hospital engaged in as they implemented the Roy Adaptation Model for nursing administration. The article discusses the use of the Roy Model in creating a nursing philosophy, mission statements, standards of practice, job descriptions, performance planning and appraisal system and a quality monitoring system. The authors conclude that the use of the Roy Model has contributed to the development of a highly integrated system of nursing administration and practice.

Adaptation, Psychological↗
PubMed1989

Visual display units.

A plethora of conditions have been linked with the use of visual display units with differing amounts of evidence. Epidemiological studies do not show an increase in miscarriage or foetal malformations but users report more visual and musculoskeletal problems. To prevent these employers need to look at the design of jobs, equipment and workplaces as well as providing training on VDU use.

Computer Systems↗
PubMed1988

Sheep leukocyte molecules: a review of their distribution, structure and possible function.

Sheep leukocyte molecules and the subsets of cells they mark have only recently been identified. In this review, the leukocyte molecules which have been characterized in sheep are described in light of recent data derived from studies in man, mouse, rat and cattle. In addition, some applications of monoclonal antibodies to studies on the immune system of sheep are discussed, with particular emphasis on the thymus and lymphocyte recirculation.

Animals↗
PubMed1985

The measurement of self-reported stress and arousal.

This paper provides further discussion on the measurement of mood using self-report inventories. It comments on questions raised by Cruickshank (1984) about the structure and use of the stress-arousal checklist developed by Mackay and Cox (Mackay et al., 1978).

Affect↗
PubMed1985

The late effect of grenade fragments.

Following the explosion of a grenade or shell, the victim may be peppered with literally hundreds of pieces of metal. Troublesome fragments which perforate a major viscus may be removed but others are often left behind, as it is felt (usually correctly) that these fragments will cause no harm. We describe a case in which a grenade fragment received 16 years previously pierced the large bowel. A psoas abscess developed which was located by ultrasound. Pus was aspirated under ultrasound control and the lesion was successfully treated by antibiotics.

Abscess↗
PubMed1984

Ranitidine: prophylaxis of duodenal ulcer recurrence.

Ninety-two patients with healed duodenal ulcer received prophylactic treatment with ranitidine, 150 mg at night, to prevent relapse. Patients were reviewed at 4-monthly intervals for clinical assessment and endoscopy. Eighty-two patients completed the trial. After one year sixty-two patients (76%) were in endoscopic remission; ten patients (12%) suffered symptomatic relapse and ten others had asymptomatic ulcers during treatment. There were no clinically significant untoward effects associated with the drug. A single nocturnal dose of 150 mg ranitidine reduces the relapse rate after duodenal ulcer healing.

Adult↗
PubMed1983

Cleft lip and palate, corneal opacities and profound psychomotor retardation. A newly recognized genetic syndrome?

Clinical histories and physical features of two sisters affected with a previously unreported syndrome are presented with illustrations. The manifestations were profound postnatal growth and psychomotor retardation, hydrocephaly, cleft lip and palate, corneal opacities, central nervous system impairment, and genitourinary anomalies. Four other siblings, two males and two females and the parents of the affected were examined and found to be normal. Infectious, metabolic, and chromosomal etiologies were excluded by appropriate studies. The most likely pattern of inheritance is autosomal recessive.

Abnormalities, Multiple↗
PubMed1982

Psychosocial factors and psychophysiological mechanisms in the aetiology and development of cancers.

Socio-cultural factors which may play a contributory role in the aetiology of cancer have been extensively investigated and it is well established that the incidence rates of different forms and sites of the disease are not equally distributed throughout the population. Social class, occupational, environmental and 'life-style' differences, amongst others, have been found to be associated with an excess risk of cancer, although the argument concerning the relative importance of these various factors remains a controversial one. It seems increasingly clear however, that there are large behavioural components which govern exposure to potential carcinogens and there is growing interest in the extent to which social and psychological demands may be associated with these agents or may operate as contributory factors in their own right. A number of early studies of psychological approaches to the study of cancer aetiology are reviewed from a methodological perspective. Much of the early work suffered from the problem that psychological characteristics of individuals who already had cancer were used to construct models concerned with aetiological factors. A number of the more recent studies which have attempted to overcome these difficulties are discussed. Tentatively, these later investigations suggest that two main groups of factors are related to an increased risk of cancer. First, the loss of, or lack of closeness or attachment to an important relation (often a parent) early in life, and second, the inability to express hostile feelings or more generally the abnormal release of emotion. Several psychophysiological mechanisms are reviewed which have attempted to account for the relationship between psychological disturbances and the onset of cancer, particularly the growing evidence which implicated a role for the immune system as a link between the central nervous system and disease processes.

Anger↗
PubMed1982

Variation in selected hematological parameters of captive red-tailed hawks.

Diurnal and winter variations of four hematological parameters were examined in 10 red-tailed hawks (Buteo jamaicensis). The mean values obtained were: 39.4% packed cell volume (PCV); 2.45 X 10(6) erythrocytes (RBC) per mm3 of blood; 5.73 mg of calcium and 1.44 mg of magnesium per 100 ml of plasma. Only the PCV and RBC count showed significant diurnal variation. When the birds were sampled at a set time of day, from November through to February, no significant changes were detected in any of the four parameters. Variation among the birds in RBC count, PCV and calcium concentration was significant on a diurnal basis but over the four month period only the PCV varied significantly.

Animals↗
PubMed1981

The treatment of "cimetidine resistant" peptic ulcers by ranitidine hydrochloride: a new histamine H2-receptor antagonist.

Twelve patients with endoscopically confirmed peptic ulcers which had failed to heal despite standard cimetidine therapy were treated with 300 mg ranitidine hydrochloride daily for 4 to 8 weeks. Nine patients had complete symptomatic relief although the ulcer was found to have healed endoscopically in only six. Two patients derived no benefit from treatment and in 1 patient symptoms continued despite ulcer healing. Ranitidine would appear, therefore, to be of benefit in some "cimetidine resistant" patients.

Cimetidine↗