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Biomedical subjects

C Watson

Publications and source records attributed to C Watson.

At least 37 records · Page 2Linked to original sources

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

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

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

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

Chronic otitis media: the significance of nasal obstruction.

The nasal airway resistance of 15 patients with unilateral chronic otitis media and 15 controls was measured by anterior active rhinomanometry. Airway resistance was measured on each side before and after decongestion to differentiate resistance due to structural abnormality from that due to mucosal swelling. The nasal resistance was significantly greater (P less than 0.01) on the side of the affected ear in patients with unilateral chronic otitis media before decongestion, but following decongestion the difference was not significant. Nasal obstruction is a significant determinant in unilateral chronic otitis media and although septal displacement may be the underlying cause, the major component of the obstruction appears to be due to an associated mucosal oedema.

Airway Resistance

Tennis elbow. A clinicopathologic study of 22 cases followed for 2 years.

Twenty-two elbows in 20 patients with persistent lateral pain due to epicondylitis had release of the common extensor origin and decortication of the lateral epicondyle. Specimens taken from the lateral epicondyle were examined histologically and compared with controls, and patients were reviewed clinically 2 (1/2-4) years after operation. Following surgery, symptoms were improved in 17 patients. Histologic examination of the bone-tendon junction revealed evidence of a repair response of variable degree, the most frequent features being mucopolysaccharide infiltration and bone formation. Fibrofatty degenerative changes were also present in some cases. There was no correlation between the intensity of the histologic reaction and the clinical outcome.

Adult

Adjunct executive appointment for faculty. An innovation in nursing collaboration.

The need for collaboration has never been greater. The healthcare delivery system faces unprecedented challenges arising from prospective payment, competition in the marketplace, higher patient acuity levels, and a shortage of professional nursing staff. The authors discuss a service-education collaboration model based on adjunct executive appointments of faculty members to healthcare organizations. The authors describe the model, a conceptual framework to guide its development, case studies of its implementation, and a summary of the benefits and risks associated with the initial implementation of the model.

Hospitals, Community

Bilateral mammary artery bypass and sternal dehiscence. A favorable outcome.

The efficacy of mammary artery bypass for coronary artery disease has been well established. The present retrospective series of consecutive patients was scrutinized to assess the incidence of sternal dehiscence following myocardial revascularization using the right and left internal mammary arteries. For comparison, the consecutive group of patients undergoing myocardial revascularization with unilateral internal mammary artery bypass was analyzed for similar sternal complications. In a consecutive series of patients, 277 patients underwent myocardial revascularization using the right and left internal mammary arteries for bypass. The overall operative mortality in this group of patients was 0.722 per cent. In this group there was an overall incidence of seven sternal dehiscences, both partial and complete for an incidence of 2.52 per cent. Upon analysis, it was shown that the female sex and diabetes were the conditions that most likely predisposed to the occurrence of sternal dehiscence whether partial or complete. For comparison, a consecutive group of 413 patients were analyzed for similar demographic data and results. The overall operative mortality in this group was 1.21 per cent. The overall incidence of sternal dehiscence both partial and complete, was 0.484 per cent. Both instances of sternal dehiscence occurred in diabetic patients and the data indicates, as in the bilateral internal mammary artery group, the presence of diabetes predisposed to the occurrence of this complication. The low overall incidence of sternal dehiscence in the expanded use of the mammary arteries should not deter the surgeon from aggressive use of the mammary arteries. One should use caution, however, in using bilateral mammary artery grafts in diabetics, women, and to a lesser extent, patients more than 70 years of age.

Adult

Provision of hearing aids: does specialist assessment cause delay?

OBJECTIVE: To identify the main delay in the provision of hearing aids for people with impaired hearing and identify possible problems and short-comings caused by a community based hearing aid dispensing service. DESIGN: Prospective cohort analysis based on data collected from patients on the duration of hearing impairment, from the referral letters in respect of the general practitioners' findings on otoscopy, and from the ear, nose, and throat assessment in the clinic with respect to the outcome of specialist otoscopy and management of the hearing impairment. SETTING: General ear, nose, and throat outpatient clinic. PATIENTS: 100 Consecutive patients aged 19-94 referred by general practitioners for the provision of hearing aids or for assessment and treatment of impaired hearing. RESULTS: Most patients with impaired hearing did not seek medical advice for at least a year. The time from referral by the general practitioner to the provision of a hearing aid was under two months. General practitioners consistently recognised normality on otoscopy but failed to recognise abnormality in eight of 45 cases. Seven patients required further investigation to exclude serious disease and nine had conditions amenable to surgery. CONCLUSIONS: The main cause of delay in treating impaired hearing is failure by patients to seek help promptly. Specialist assessment of patients with impaired hearing is preferable and does not necessarily cause delay in providing hearing aids. The provision of hearing aids should remain a hospital based service.

Adult

Derivation of a T cell line that is highly responsive to IL-4 and IL-2 (CT.4R) and of an IL-2 hyporesponsive mutant of that line (CT.4S).

The derivation of subline of CTLL cells that grow in IL-4/B cell stimulatory factor-1 is described. These cells, designated CT.4R cells, were obtained by extended culture of the CTLL line CT.EV in IL-4. CT.4R cells are highly responsive to both IL-4 and IL-2. Mutagenesis of CT.4R cells with ethylmethane sulfonate and selection for lack of expression of the p55 chain of the IL-2R was carried out and a clone was selected that was hyporesponsive to IL-2 but retained full sensitivity to IL-4. These cells, designated CT.4S cells, develop a very meager response to IL-2 at concentrations of 100 U/ml or less although that display vigorous responses to higher IL-2 concentrations. CT.4S cells give measurable responses to 3-10 U/ml (approximately 15-50 pg/ml) of IL-4. CT.4R and CT.4S cells fail to respond to IL-1, IL-3, IL-6, granulocyte-macrophage-CSF, granulocyte-CSF, CSF-1 or IFN-gamma. Thus, CT.4S cells can be used as a sensitive and specific bioassay for IL-4. ID CT.4R cells can be grown in either IL-4 or IL-2. When grown in IL-4, CT.4R cells express small amounts of the p55 chain of the IL-2R but rapidly upregulate their level of expression of p55 when IL-2 is added and rapidly diminish p55 expression when IL-2 is removed. Thus, although IL-2 and IL-4 both stimulate vigorous growth responses by CT.4R cells, they differ in their capacity to induce the expression of the p55 chain implying that their mechanisms of T cell stimulation are not identical.

Cell Line

MS: a localized immune disease of the central nervous system.

The precise role of T cells in multiple sclerosis (MS) remains to be defined. No MS-specific antigen has been found. The autoimmune hypothesis for MS rests on immune changes seen in the spinal fluid and brain and on the demonstration, in an experimental animal model, that T cells raised to myelin basic protein transfer demyelination. In this review, Virginia Calder and colleagues focus on recent studies suggesting that in MS, the initial T-cell response occurs within the central nervous system and that the blood poorly reflects this immune activity. This contrasts with the animal model, experimental allergic encephalomyelitis, where the initial immune response is peripheral.

Central Nervous System

Visual field loss in migraine.

Ocular symptoms are a common, though transient, initial component of migraine. Although permanent visual loss has been reported in a limited number of patients, detailed evaluations of the visual field using current techniques have not been conducted. This study examined the prevalence of visual field loss in patients with migraine, using an automated static perimeter. All patients had at least a 2-year history of migraine (as diagnosed by a neurologist) and no ocular problems (by history or as determined by a visual screening examination consisting of acuity, intraocular pressure [IOP], and evaluation of the disc). The authors' results for 60 migraine patients showed that 21 (35%) had some form of visual field abnormality (P less than 0.05). The prevalence of visual field loss was greater with increasing age and duration of disease. These results suggest that visual field loss from migraine may be more common than previously considered. This information also may be useful in elucidating the relationship between migraine and certain vascular conditions of the eye.

Adolescent

Site of injury headache.

Wolff described three types of post-traumatic headaches (PTH). In type II PTH, the pain is located at the site of injury. Local soft tissue trauma and direct damage or entrapment of sensory nerves in the scar tissue are thought to be responsible for this type of headache. It is often difficult to study the neurological and autonomic changes in the scalp in these patients. We report here 8 patients with PTH in whom the site of injury was on the face thereby allowing us to evaluate the local neurological changes with greater accuracy. The results of this study corroborate Wolff's view of the pathogenesis of type II or "site of injury" PTH.

Adult