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Biomedical subjects

J Knight

Publications and source records attributed to J Knight.

At least 127 records · Page 7Linked to original sources
PubMed1987

Is nursing a profession? Results of a Missouri study.

This article examines the question of whether or not nursing is or should be a profession. The conclusion is based primarily on an analysis of what constitutes a profession and an empirical study of some nursing practices and attitudes. The analysis of professions recognizes three prominent models in sociology: trait, functional, and power or control. It bypasses these in favor of a "cluster concept," which asserts that the public has a number of expectations of an occupation before it will bestow the status of profession upon it. We then give an analysis of some of the results of the survey of a sample of Missouri registered nurses. The gist of the data is said to reflect the facts that these nurses think nursing is or should be a profession, but that other factors tend to show that nursing lacks the requisite cluster to substantiate the claim to be a profession. We conclude that nursing should perhaps not be a profession since it has been a bastion of the "ethics of compassion" in a world that is increasingly beset by an "ethics of competence."

Attitude of Health Personnel↗
PubMed1986

Morbidity patterns in a general paediatric unit in rural Western Australia.

Admissions to the Medical Paediatric Unit at Derby Regional Hospital in 1984 were reviewed. There were 536 admissions (289 males and 247 females). The average number of inpatients per day was 11.7, average duration of stay was 8.0 days, and there was one hospital death. Aboriginal children represented 90% of admissions and 59% of these were under two years of age. Several major problems were often encountered in individual children; these included respiratory, gastrointestinal and renal disease, failure to thrive and anaemia. Plasma electrolyte levels were measured in 82 children with gastroenteritis. Of these children 45 (55%) had a serum potassium level of less than 3.0 mmol/L and eight (10%) had a serum potassium level of less than 2 mmol/L. One hundred and four children were diagnosed as having pneumonia; 74 (71%) of them responded to penicillin. In 19 (21%) of 92 children who failed to thrive, no definite medical cause was found. The remainder had a combination of diarrhoeal disease, and chest and urinary tract infections. Anaemia, renal calculi and rheumatic fever are also common medical problems in the Kimberley region.

Australia↗
PubMed1986

Underwater diving.

Explore the source record for details and available documents.

Decompression Sickness↗
PubMed1986

Identification of amine components in a glycolipid membrane-binding domain at the C-terminus of human erythrocyte acetylcholinesterase.

Purified human erythrocyte acetylcholinesterase was labeled by reductive radiomethylation with saturating amounts of [14C]formaldehyde and sodium cyanoborohydride. Acid hydrolysis and automated amino acid analysis permitted both identification of radiomethylated components by their coelution with radiomethylated standards and quantitation of these components. The methylated N-terminal amino acids glutamate and arginine were observed at levels of 0.66 and 0.34 residues, respectively, per 70-kilodalton subunit, and lysine residues were methylated on their epsilon-amino groups to a level of 7.40 residues per subunit [Haas, R., & Rosenberry, T.L. (1985) Anal. Biochem. 148, 154-162]. In addition, each subunit contained 1.35 residues of methylated ethanolamine and 0.98 residue of methylated glucosamine. Papain digestion cleaved the intact enzyme into two fragments, an enzymatically active hydrophilic fragment and a small hydrophobic fragment that represented the membrane-binding domain. The radiomethylated amino acids were quantitatively retained in the hydrophilic fragment, while the methylated ethanolamine and glucosamine were confined exclusively to the hydrophobic domain fragment. This fragment included the C-terminal dipeptide of the subunit. Peptide sequencing by manual Edman methods was combined with radiomethylation to demonstrate the sequence His-Gly-ethanolamine-Z for the hydrophobic domain fragment. The ethanolamine residue in this sequence is in amide linkage to the C-terminal Gly and is clearly distinct from the ethanolamine residues in Z which are susceptible to radiomethylation in the intact enzyme. Since Z also includes glucosamine and 2 mol of fatty acids [Roberts, W.L. & Rosenberry, T.L. (1985) Biochem. Biophys. Res. Commun. 133, 621-627], we conclude that the membrane-binding domain of human erythrocyte acetylcholinesterase is a covalently linked glycolipid at the C-termini of the subunits.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1986

Analysis of the autophosphorylation activity of transformation defective mutants of avian erythroblastosis virus.

The v-erb B protein of avian erythroblastosis virus (AEV) possesses an associated protein kinase activity in vitro. Analysis of temperature-sensitive mutants, and nonconditional host range mutants of AEV demonstrated that there was no simple correlation between this autophosphorylation activity and the transformation ability of the various AEV mutants. These data suggest that although this kinase activity may be central to transformation by AEV it is in itself insufficient.

Alpharetrovirus↗
PubMed1986

Thyroid-stimulating autoantibodies usually contain only lambda-light chains: evidence for the "forbidden clone" theory.

Burnet's "forbidden clone" theory would predict that in patients with Graves' disease the pathogenic thyroid-stimulating autoantibody (TSab)-secreting clones arise by somatic mutation. Because each lymphocyte and its progeny are permanently committed to producing antibodies of a single light chain type, a clone arising by somatic mutation occurring in a single cell would be expected to produce autoantibodies of exclusively kappa or exclusively lambda type in an individual patient. Using affinity chromatographic techniques and monoclonal antibodies, we investigated the light chain type of TSab in 11 patients with Graves' disease. In all patients tested, TSab activity was confined to a single light chain type, confirming the recent work of Zakarija who used affinity chromatography with polyclonal antisera, but contrasting with earlier studies which used immuno-precipitation methods. Furthermore, the light chain type was lambda in 10 of the 11 patients. These observations provide support for the forbidden clone theory. In addition, the marked preponderance of patients producing TSab of the lambda-light chain type indicates that TSab are more likely to arise from the lambda repertoire of clones than from the kappa repertoire and suggests that immunoglobulin light chain V genes may be genetic determinants for susceptibility to Graves' disease.

Antibodies, Monoclonal↗
PubMed1986

A simple radial immunodiffusion method for assay of beta 2-microglobulin in serum.

In this method for clinical measurement of beta 2-microglobulin, a 10 g/L agarose gel containing anti-beta 2-microglobulin is used, with subsequent staining with Coomassie Blue. Although the method is slow (requiring 30 h), it is inexpensive, reliable, and accurate over the range of 1 to 10 mg/L, and is useful in the determination of beta 2-microglobulin in serum and cerebrospinal fluid. A modified procedure in which staining with silver is used may be sufficiently sensitive for the clinical assay of urine.

Humans↗
PubMed1986

Tracheo-oesophageal 'puncture speech'. An assessment technique for failed oesophageal speakers.

We describe the assessment procedures used at Charing-Cross Hospital to investigate laryngectomees who failed to develop oesophageal voice and give the results of assessment in 50 patients. Anatomical or physiological abnormalities in the reconstructed pharynx were found in all patients, and we feel these significantly contributed to the failure of achieving an oesophageal voice. The four cases of failure were due to hypotonicity of the pharyngo-oesophageal muscles, hypertonicity, frank spasm and stricture. This distinction can be used as a functional classification of failure as treatment for each group has to be different if successful surgical voice restoration is to be achieved. Patients with hypotonicity need to use external pressure; those with mild hypertonicity are able to use a low pressure tracheo-oesophageal voice prosthesis; those with spasm need a pharyngo-oesophageal myotomy prior to "puncture", while those with stricture need surgical correction.

Esophagus↗
PubMed1985

Biosynthesis and processing of legumin-like storage proteins in Lupinus angustifolius (lupin).

Synthesis, secretion and post-translational proteolysis of the storage proteins in cotyledons of Lupinus angustifolius L. (lupin) have been examined in vivo and in vitro by using a combination of pulse-chase experiments with [3H]- or [35S]-labelled amino acids, subcellular fractionation and cell-free translation from poly(A)+ (polyadenylylated) RNA or membrane-bound polyribosomes. Related polypeptides were identified by immunoprecipitation, separation on sodium dodecyl sulphate/polyacrylamide gels and fluorography. The synthesis and processing of two proteins were compared. Conglutin alpha, the 11 S protein, was found as a family of precursor polypeptides of Mr 68000-88000 when translated from poly(A)+ RNA under conditions where signal segments were not cleaved, and Mr 64000-85000 both when sequestered into the endoplasmic reticulum and when accumulated in the protein bodies. Pulse-chase labelling showed that cotyledons from early stages of development were completely incapable of further proteolysis of these precursors. Nevertheless, in the same juvenile cotyledons, the precursors of the minor storage protein conglutin gamma, two polypeptides with Mr 50000-51000, were proteolytically cleaved to mature subunits of Mr 32000 and 17000 within 2 h. Further cleavage of the precursors of conglutin alpha into families of mature subunits of Mr 21000-24000 and 42000-62000 was detected in more mature cotyledons. A model is proposed which suggests that the mature subunits are produced by a single proteolytic cleavage of each of the three major precursors of conglutin alpha and also suggests that a close similarity exists between these subunits and those of other legumin-like proteins. The enzyme responsible for this cleavage, which appears at a specific stage in the middle of cotyledonary development, seems to be an integral part of the programmed developmental sequence in these pods.

Biological Transport↗
PubMed1985

Monoclonal antibodies specific for subsets of epidermal keratins: biochemical and immunocytochemical characterization--applications in pathology and cell culture.

Keratin composition has been widely used as a biochemical marker of differentiation in normal epithelia, cell culture systems and tumours of epithelial tissues. We have been developing a model system for the study of human squamous epithelial cell differentiation, and among a panel of monoclonal antibodies we have generated for analysing this system are two antibodies recognizing subsets of epidermal keratins. The two antibodies, designated LICR-LON-16a and LICR-LON-29b, were raised to the human squamous carcinoma cell line LICR-LON-HN-5, and we describe here their biochemical and immunocytochemical characterization. Antibody 16a reacts with only epidermal basal cells in normal human skin and shows specificity for the 45 and 46 kdalton keratins. Antibody 29b stains all living layers of the epidermis, and reacts with a broad range of ketain polypeptides, (45-56 kdaltons) in immunoblotting analyses. We have investigated the alterations of cellular staining that occur in chronic hyperproliferative skin diseases and carcinomas and compared this with the staining of multilayered cultures of normal keratinocytes and the HN-5 cell line. We show that in squamous cell carcinomas and in HN-5 cell xenografts 16a and 29b stain only the well-differentiated cell types. Furthermore we found that the basal cell specificity of 16a was lost in all of the hyperproliferative skin lesions examined including psoriasis and eczema. This transition to suprabasal staining pattern was also seen in the cultures of normal keratinocytes and HN-5 cells. We conclude that aberrant keratin synthesis or abnormal post-translational processing of keratins associated with an increased rate of cell turnover could account for the altered expression of the epitope recognized by antibody 16a.

Antibodies, Monoclonal↗
PubMed1985

Immunocytochemical identification of cell types in pleomorphic adenoma, with particular reference to myoepithelial cells.

An immunocytochemical study was carried out on normal salivary gland tissue and ten salivary gland pleomorphic adenomas. Antibodies to myosin were used to stain myoepithelial cells. Duct cells were stained using an antibody to total keratin and a subpopulation of basal duct cells with an antibody to 45/46K keratins. Basement membranes were stained with anti-type IV collagen. The results demonstrated that myoepithelial cells are relatively rare in the majority of pleomorphic adenomas and that many of the cells which have been classically described as myoepithelial in routine histological preparations do not clearly show this type of differentiation. However, the tumors presented a spectrum of differentiation patterns from those that were mainly ductal to the rare tumour which was largely myoepithelial. It is further suggested that the 45/46K keratin antibody is capable of identifying a subpopulation of cells which could possibly be important in the histogenesis of this tumour.

Adenoma, Pleomorphic↗
PubMed1985

The biochemical and immunocytochemical characterisation of an antigen on the membrane of basal cells of the epidermis.

A murine monoclonal antibody, LICR-LON-23.10, which had been raised against a well-differentiated squamous cell carcinoma cell line (LICR-LON-HN5), recognises an antigen which is present on the membrane of basal cells of the epidermis. The tissue distribution of the antigen, as defined using immunohistochemical techniques, suggests that it is expressed preferentially on cells which are adjacent to a basement membrane. In squamous cell carcinomas, the antigen is expressed uniformly on undifferentiated cells, but in areas of keratinisation, the antigen is absent. The antigen recognised by the antibody was characterised as being a pair of glycoproteins with molecular masses of 120 and 135 daltons. The antibody was used for flow-cytometric analyses of epidermal keratinocyte preparations. Together with other basal cell markers, this antibody may be useful in the characterisation of the epidermal basal cell population as well as in broadening our understanding of the interaction between epithelial cell populations and their relationship with basement-membrane components.

Animals↗
PubMed1984

The differential effects of hydrocortisone on activation and tolerance induction in human T lymphocyte clones.

The in vitro effects of hydrocortisone on T cell activation and tolerance induction were investigated using human influenza virus immune T cell lines and clones. Hydrocortisone at 10(-9) to 10(-6) molar concentrations was able to inhibit the antigen induced but not the T cell growth factor (TCGF) mediated proliferative response of both the lines and clones. However, hydrocortisone was able to inhibit TCGF production by cloned T cells. The proliferative response of cloned T cells to intact influenza virus A/Texas/1/77 was more markedly inhibited by equivalent concentrations of hydrocortisone than was the response of that clone to a 24 amino acid sequence (p20) of the haemagglutinin molecule implying that hydrocortisone may also act at the level of antigen processing. Furthermore hydrocortisone was able neither to induce T cell tolerance alone nor to inhibit antigen specific tolerance induction. However, hydrocortisone did lower the antigen threshold for tolerance induction. The possible mechanisms of hydrocortisone activity in the modulation of T cell regulation in autoimmune disease are discussed.

Antigens, Viral↗
PubMed1984

Differentiation of normal and malignant human squamous epithelium in vivo and in vitro: a morphologic study.

We report a light microscopic and ultrastructural analysis of the comparative degrees of differentiation seen in keratinocytes derived from the tongue and epidermis with those of a well-differentiated human squamous carcinoma cell line (LICR-LON-HN5). When growing on plastic substrates, all cultures had a similar morphology, with multilayering and the production of cornified envelopes. When cultured on collagen gels the structure was more organized, with keratohyalin granules and keratin whorl formation in both the normal and the malignant cultures. Normal keratinocytes injected into athymic mice produced epidermal cysts, while cells from the cell line produced well-differentiated squamous cell carcinomas, which were partially solid and partially cystic. the tumor was well organized, with identifiable basal cells, spinous cells, keratohyalin granules, and a prominent basal lamina at the stromal/epithelial interface. This model is to be developed for comparative studies between normal and malignant cells, with particular reference to basement membrane production and to investigations of the relative importance of extrinsic and intrinsic factors in the control of squamous differentiation.

Animals↗