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Biomedical subjects

C Watson

Publications and source records attributed to C Watson.

At least 109 records · Page 6Linked to original sources
PubMed1993

Application of an immortalized human endothelial cell line to the leucocyte:endothelial adherence assay.

This report shows that an immortalized endothelial cell line (EA.hy 926) is able to substitute for secondary cultures of human umbilical vein endothelial cells (HUVEC) in the leucocyte:endothelial adherence assay. Enriched preparations of blood polymorphonuclear leucocytes, monocytes and resting and activated lymphocytes exhibited similar adherence characteristics to HUVEC and the EA.hy 926 cells. Cytokines such as tumour necrosis factor (TNF) act on endothelial cells to increase their adhesiveness for leucocytes and in this study there was no difference between TNF-treated HUVEC and EA.hy 926 cells in supporting the enhanced binding of leucocytes. The adherence promoting effect of TNF-treated EA.hy 926 cells appears to be dependent upon their endothelial properties since TNF treatment of A549 cells, the permanent human cell line used to generate the hybrid EA.hy 926 cells did not augment lymphocyte attachment. Monoclonal antibodies against CD11a and CD18 inhibited the binding of lymphocytes to untreated and TNF-treated HUVEC and EA.hy 926 cells and ICAM-1 expression was increased on both monolayers following treatment with TNF. The availability of a hybrid endothelial cell line whose adhesive properties are similar to those of recently isolated endothelial cells should benefit the study of factors that govern leucocyte-endothelial cell interactions and be advantageous to the longitudinal investigation of leucocyte adherence under static conditions.

Antigens, CD↗
PubMed1993

The role of the nurse in ethical decision-making in intensive care units.

This paper focuses on the nurses' role in ethical decision-making in intensive care units (ICUs) of hospitals in the UK. There is a paucity of research on the topic, studies published are generally North American or Canadian in origin. The available literature suggests that although nurses are constantly at the intensive care patient's bedside, often making complex decisions about treatment and care, their involvement in ethical decision-making is limited. This paper provides a review of the literature on how ethical decisions are made and the influences on nurses' participation in this process.

Decision Making, Organizational↗
PubMed1993

Effects of substrate and inhibition of oxidative metabolism on contraction and myosin phosphorylation in ASM.

Steady-state active stress in smooth muscle is maintained by cross bridges which undergo continuous cycling and myosin phosphorylation, and the two processes both consume ATP. In this study, we investigated whether energy utilization by cross-bridge cycling and myosin phosphorylation is compartmentalized and examined their relative affinities for ATP in airway smooth muscle. We measured active stress, myosin phosphorylation, O2 consumption, and tissue ATP content in bovine tracheal smooth muscle activated by K+ depolarization when glucose was replaced by pyruvate and when oxidative metabolism was inhibited by hypoxia or uncoupled by 2,4-dinitrophenol. The results indicate that ATP produced from both glycolysis and oxidative metabolism is available to both cross-bridge cycling and myosin phosphorylation. However, steady-state myosin phosphorylation was insensitive to the inhibition of oxidative metabolism by hypoxia and mitochondrial uncoupling when steady-state isometric stress and tissue ATP content were significantly reduced. These results suggest that, relative to actomyosin adenosine 5'-triphosphatase, myosin light chain kinase has a higher affinity for ATP in intact airway smooth muscle. However, peak myosin phosphorylation associated with the initial rapid stress development was sensitive to inhibition of oxidative metabolism, probably reflecting a lower content of intracellular calcium store as a result of metabolic inhibition.

2,4-Dinitrophenol↗
PubMed1993

MRI volumetric measurement of amygdala and hippocampus in temporal lobe epilepsy.

We performed MRI volumetric measurements of the amygdala (AM), the hippocampal formation (HF), and the anterior temporal lobe in a group of 30 patients with intractable temporal lobe epilepsy (TLE) and in seven patients with extratemporal lobe foci. Measurements were analyzed with a semiautomated software program and the results compared with those of normal controls and correlated with the findings of all other investigations. In particular, we compared the results with the lateralization of epileptic abnormalities in the EEG. Volumetric studies of AM and HF showed lateralization of measurable atrophy consistent with that derived from extracranial and intracranial EEG examinations. The HF volumes were more sensitive and provided a lateralization in 87%. Combined measurements of AM and HF showed lateralization in 93%, always congruent with the results of EEG lateralization. This slight but important additional improvement in discrimination justifies using AM measurements in MRI volumetric studies of mesial temporal structures. Volumetric studies combined with other currently employed noninvasive techniques may diminish the need for invasive methods of investigation in patients with TLE.

Adult↗
PubMed1993

Menière's syndrome: an atypical presentation of giant cell arteritis (temporal arteritis).

The authors discuss three patients with biopsy-proven giant cell arteritis (GCA) who experienced significant auditory and vestibular symptoms. Two of the patients who presented with audiovestibular symptomatology died as a direct result of GCA affecting the vertebral arteries. Postmortem findings are reported. This report illustrates the importance of maintaining a high index of suspicion of GCA in elderly patients who present with the acute onset of audio-vestibular symptoms. These symptoms can be a herald of brain stem infarction if giant cell arteritis is the underlying cause. High-dose prednisone and rheumatologic/neurologic consultation is required.

Aged↗
PubMed1992

Failure of signaling through a chimeric class I-immunoglobulin molecule expressed on the surface of transfected B lymphoma cells and cells of transgenic mice.

To test the possibility that the crosslinkage of molecules expressing a transmembrane region derived from the membrane form of the mu immunoglobulin heavy chain would be sufficient for signal transduction in B cells, a chimeric gene (Kk-mu) consisting of extracellular exons of the class I gene H-2Kk and the transmembrane and cytosolic exons of the mu constant region gene was introduced into WEHI-231 B lymphoma cells and into mouse blastocysts. A protein consistent with the predicted product of the Kk-mu gene was expressed in a transfected cell clone (S18) and in transgenic mice. Crosslinkage of Kk-mu protein with soluble, Sepharose-bound, or dextran-conjugated anti-H-2Kk antibodies failed to induce the accumulation of inositol phosphates or to elevate intracellular calcium concentrations in either S18 cells or B lymphocytes from transgenic mice. Furthermore, crosslinkage of Kk-mu did not inhibit growth of S18 cells or stimulate DNA synthesis by transgenic B cells, in the presence or absence of interleukin-4. The failure of crosslinkage of Kk-mu to initiate detectable intracellular biochemical change or to effect cellular growth suggests that simple crosslinkage of molecules expressing the mu transmembrane region is not sufficient to transduce signals in B cells.

Animals↗
PubMed1992

Derivation of a monoclonal anti-murine IL-4 antibody specific for an epitope expressed on denatured molecules.

Monoclonal antibodies to interleukin 4 (IL-4) were generated by immunization with recombinant IL-4 and screening by binding to IL-4 adsorbed to plastic surfaces. Three antibodies were obtained that scored well in this assay and one, 13E1, was studied in detail. It was very effective in detecting IL-4 by Western blotting whereas a neutralizing anti-IL-4 antibody, 11B11, was 50-100-fold less sensitive as a detecting agent. Sequential immunoprecipitation and biosynthetic labelling studies indicated that the 11B11 and 13E1 epitopes are largely expressed on different forms of IL-4. 13E1 was able to detect cytosolic IL-4 both by immunohistochemical and flow cytometric analysis of fixed cells. This was routinely successful in an insect cell line (Sf9) expressing large amounts of IL-4 as a result of infection with a recombinant 'IL-4 baculovirus'. Although stimulated D10 cells could also be shown to express IL-4 in their cytosol, positive results were not obtained in all such studies and we have failed to detect IL-4 production by normal T cells using this method. This antibody may have substantial value in detecting IL-4 by Western blots and as a tool to analyze the biosynthesis of IL-4. With suitable improvement in sensitivity, it also may prove valuable in the detection of IL-4 in the cytosol of individual cells.

Animals↗
PubMed1992

Necrosis of the incus by the chorda tympani nerve.

Ossicular necrosis is often associated with chronic adhesive otitis media. An unusual abnormality discovered in an incus removed during tympanoplasty is reported. The long process appears to have been grooved by pressure from the chorda tympani. An alternative theory to explain the vulnerability of the long process of the incus is suggested.

Chorda Tympani Nerve↗
PubMed1992

Anatomic basis of amygdaloid and hippocampal volume measurement by magnetic resonance imaging.

Both the amygdala and the hippocampus are involved in the pathogenesis of a number of neurologic conditions, including temporal lobe epilepsy, postanoxic amnesia, and Alzheimer's disease. To enhance the investigation and management of patients with these disorders, we developed a protocol to measure the volumes of the amygdala and as much of the hippocampus as possible (approximately 90 to 95%) using high-resolution MRI. We present the anatomic basis of these two protocols and our results in normal control subjects. These volumetric studies of the amygdala may clarify the role of this structure in the pathogenesis of temporal lobe epilepsy.

Adult↗
PubMed1991

High-level production of murine interleukin-5 (IL-5) utilizing recombinant baculovirus expression. Purification of the rIL-5 and its use in assessing the biologic role of IL-5 glycosylation.

We describe here a recombinant baculovirus expression system useful for high level production of murine recombinant interleukin-5 (rIL-5). In addition, we describe a single-step technique of purification of the rIL-5 from the baculovirus-infected Sf9 cell supernatants, using an anti-IL-5 affinity column. The baculovirus-derived rIL-5 has physical properties and functional activities in various lymphoid cell assays similar to those of natural T cell-derived IL-5 and reacts with anti-IL-5 antibodies. Finally, the rIL-5 is similar to natural T cell-derived IL-5 in manifesting heterogeneous glycosylation; however, glycosylation does not appear to be necessary for biologic function, at least in a lymphoid cell proliferation assay.

Animals↗
PubMed1991

Senior registrar training in otolaryngology: an audit of trainees.

Senior registrars in otolaryngology were asked to complete a questionnaire about the opportunities for training and research offered by their current post. Trainees were asked whether, in their opinion, the post complied with the SAC requirements for a training post. Completed replies were received from 53 (66%) trainees. Most trainees were fairly satisfied with their post but 26% considered that it did not meet with the ideals of a training post as laid down by the SAC. Large variations were noted between posts in the exposure to specialist clinics, own operating lists and research opportunities. Outpatient experience and, in particular, whether the trainee was able to follow up their own post-operative cases adequately appeared to be an important determinant in whether or not trainees were satisfied with their current post.

Ambulatory Care↗
PubMed1991

Status epilepticus. Clinical features, pathophysiology, and treatment.

During the past two decades, substantial progress has been made in the understanding of the clinical features, classification, pathophysiology, central nervous system consequences, and treatment of status epilepticus. The most commonly used drug regimens have advantages and disadvantages, and, in this review, I recommend a protocol for the treatment of status epilepticus. An important concept in the approach to patients in generalized tonic-clonic status epilepticus is that treatment should be administered within a predetermined time frame. Clinical and experimental research indicates that continuous seizure activity for longer than 60 to 90 minutes may result in irreversible brain damage. As our understanding of the basic mechanisms of neuronal function and seizure generation advances, it is expected that more specific and novel approaches to the treatment of status epilepticus will emerge.

Benzodiazepines↗
PubMed1990

Osteochondroma of the tongue.

A case is described of osteochondroma of the tongue and the literature on osteomata, chondromata and osteochondromata of the tongue is reviewed. The tendency for these tumours to arise in the region of the foramen caecum has been noted in previous reports as has the female preponderance. It has been suggested that they arise from remnants of branchial arch cartilage. The variation in the duration and age at presentation of the lesion has not been explained and an alternative theory is suggested.

Aged↗