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Biomedical subjects

K Young

Publications and source records attributed to K Young.

At least 91 records · Page 5Linked to original sources
PubMed1996

Establishing a framework for research: the example of needs assessment.

This paper explains the early planning stage of a study commissioned by the English National Board which will investigate the changing educational needs of community nurses with regard to needs assessment and quality of care in the context of the NHS and Community Care Act 1990. Two focus groups, comprising 22 participants altogether, generated data which were used to augment and clarify issues explored in an initial literature review. Some of the methodological issues are explained. Traditional community nursing approaches to needs assessment appeared to value process and integration, while the new legislation emphasizes the separateness of assessment; there is a danger that it may be seen as a single event. The consumer views were both supportive and critical about each of the approaches; some important insights were gained, and a confident basis from which to launch the study identified. The approach offers one possible way to clarify the starting point of a project when carrying out a standard literature review seems insufficient. This may occur with under-researched or rapidly changing phenomena, or if a field of interest is the subject of multiple interpretations or lack of consensus.

Community Health Nursing↗
PubMed1996

Health, health promotion and the elderly.

Health promotion is a mode of practice which is being increasingly examined by policymakers (DHSS, 1987; DoH, 1992). Although practitioners are being required to screen people over 75 years of age and are exhorted to reduce accidents in the elderly by 33% between 1990 and 2005 (DoH, 1992), there is evidence that they do not value this sort of work (Pursey & Luker, 1993). This paper looks at the findings from 178 interviews with people aged over 75 years, examining the importance of health and health promotion to the elderly. Further to the work of Cox et al. (1987), it is clear that people aged over 75 years continue to engage in a wide variety of activities which are designed to keep or improve their health. Elderly people's accounts of their health suggest that the real influence of social circumstances and environment must be assessed and planned for if health promotion activity is to have relevance and meaning to this group of people. Evidence is presented which indicates that the elderly are a group of people who would welcome health-promotion activity provided it is given in easily accessible forms. The notion of client participation is highlighted as a difficult area, which is likely to require particular skill in working with elderly clients. In the light of these findings, practitioners may need to examine their own attitudes to their work with the elderly.

Aged↗
PubMed1996

Prion protein amyloidosis.

The prion protein (PrP) plays an essential role in the pathogenesis of a group of sporadic, genetically determined and infectious fatal degenerative diseases, referred to as "prion diseases", affecting the central nervous system of humans and other mammals. The cellular PrP is encoded by a single copy gene, highly conserved across mammalian species. In prion diseases, PrP undergoes conformational changes involving a shift from alpha-helix to beta-sheet structure. This conversion is important for PrP amyloidogenesis, which occurs to the highest degree in the genetically determined Gerstmann-Sträussler-Scheinker disease (GSS) and prion protein cerebral amyloid angiopathy (PrP-CAA), while it is less frequently seen in other prion diseases. GSS and PrP-CAA are associated with point mutations of the prion protein gene (PRNP); these conditions show a broad spectrum of clinical presentation, the main signs being ataxia, spastic paraparesis, extrapyramidal signs and dementia. In GSS, parenchymal amyloid may be associated with spongiform changes or neurofibrillary lesions; in PrP-CAA, vascular amyloid is associated with neurofibrillary lesions. A major component of the amyloid fibrils in the two diseases is a 7 kDa peptide, spanning residues 81-150 of PrP.

Amino Acid Sequence↗
PubMed1996

Hepatic extraction efficiency and excretion rate of technetium-99m-mebrofenin in dogs.

UNLABELLED: Quantitative hepatobiliary scintigraphy aids in the diagnosis of hepatic disease. Two scintigraphic parameters that have great value in discriminating between hepatocellular and biliary disease are hepatic extraction fraction (HEF), which is a measure of the hepatic extraction efficiency (HEE), and hepatic excretion rate. It is generally accepted that hepatic extraction fraction is normally 100%, but a review of the literature provided little information on the actual HEF of 99mTc-mebrofenin. METHODS: We determined the HEE of 99mTc-mebrofenin in nine normal dogs after direct injection into the afferent hepatic vasculature using a two-compartment model. The forward and reverse rate constants for the two-compartment model were solved by a simple graphic approach and a more complex numerical approach using a nonlinear least squares algorthm. The HEEs were determined using both methods. RESULTS: The HEE for the graphic and numerical methods of analysis were not significantly different and were calculated to be 92.2 +/- 4.75% (mean +/- s.d.) and 91.2 +/- 4.44% (mean +/- s.d.) by each method, respectively. The half-time clearance of 99mTc-mebrofenin was 19.10 +/- 4.86 min (mean +/- s.d.). CONCLUSION: This study validates the assumption that the normal HEE of 99mTc-mebrofenin is nearly 100%, barring species differences.

Aniline Compounds↗
PubMed1995

The envA permeability/cell division gene of Escherichia coli encodes the second enzyme of lipid A biosynthesis. UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase.

The envA gene of Escherichia coli has been shown previously to be essential for cell viability (Beall, B. and Lutkenhaus, J. (1987) J. Bacteriol. 169, 5408-5415), yet it encodes a protein of unknown function. Extracts of strains harboring the mutant envA1 allele display 3.5-18-fold reductions in UDP-3-O-acyl-N-acetylglucosamine deacetylase specific activity. The deacetylase is the second enzymatic step of lipid A biosynthesis. The structural gene coding for the deacetylase has not been assigned. In order to determine if the envA gene encodes the deacetylase, envA was cloned into an isopropyl-1-thio-beta-D-galactopyranoside-inducible T7-based expression system. Upon induction, a protein of the size of envA was highly overproduced, as judged by SDS-PAGE. Direct deacetylase assays of cell lysates revealed a concomitant approximately 5,000-fold overproduction of activity. Assays of the purified, overproduced EnvA protein demonstrated a further approximately 5-fold increase in specific activity. N-terminal amino acid sequencing of the purified protein showed that the first 20 amino acids matched the predicted envA nucleotide sequence. Contaminating species were present at less than 1% of the level of the EnvA protein. Thus, envA is the structural gene for UDP-3-O-acyl-GlcNAc deacetylase. Based on its function in lipid A biosynthesis, we propose the new designation lpxC for this gene.

Alleles↗
PubMed1995

Gerstmann-Sträussler-Scheinker disease (PRNP P102L): amyloid deposits are best recognized by antibodies directed to epitopes in PrP region 90-165.

Gerstmann-Sträussler-Scheinker (GSS) disease is a familial neurological disorder pathologically characterized by accumulation of prion protein (PrP) in the form of fibrillary and non-fibrillary deposits within the cerebrum and cerebellum. We have studied two patients in whom the disease is caused by a leucine for proline amino acid substitution at residue 102 of PrP. In both patients, the neuropathologic findings are similar, consisting of spongiform changes, amyloid deposits, and gliosis. To investigate the antigenic profile of PrP deposits, we used antibodies raised against several peptides that correspond to segments of the N-terminus, repeat region, midregion, and C-terminus of PrP. By immunohistochemistry, PrP amyloid cores are best labeled by antibodies directed to epitopes spanning PrP residues 90-165. In GSS disease caused by a substitution of thymine to cytosine at PRNP codon 198 (Indiana kindred), the major amyloidogenic peptide spans residues 58-150; therefore, in these two genetic forms of GSS disease, amyloid may be composed of different peptides.

Adult↗
PubMed1995

Gerstmann-Sträussler-Scheinker disease with mutation at codon 102 and methionine at codon 129 of PRNP in previously unreported patients.

We present two patients with Gerstmann-Sträussler-Scheinker disease (GSS), one from a previously undescribed kindred and one from the Canadian branch of a previously reported British kindred. In both patients, GSS is caused by a substitution of thymine for cytosine at codon 102 of the prion protein gene (PRNP). In each patient, we confirmed the clinical diagnosis by neuropathologic examination. The mutation, causing a substitution of leucine for proline at residue 102 (P102L) of the prion protein, has been previously reported in at least 30 other families. In the patients described here, the mutation was in coupling with methionine at PRNP codon 129.

Adult↗
PubMed1995

Evenoming by Bungarus multicinctus (many-banded krait) in Hong Kong.

We describe the clinical course of two cases of envenoming by the many-banded krait (Bungarus multicinctus). A man developed generalized paralysis and respiratory failure with transient hypertension. Nerve conduction studies revealed normal motor and sensory conduction velocities with reduced motor unit action potential amplitudes consistent with neuromuscular blockade. He showed a slight transient response to the banded krait (B. fasciatus) antivenom but required ventilatory support for 8 days. After the fourth day, there was some response to treatment with anticholinesterase. Another man developed diplopia, dysphagia and leg weakness but recovered spontaneously after 48 hours.

Adult↗
PubMed1994

[Small-cell carcinoma in the esophagus].

The oat-cell carcinoma is more frequently found in the lungs, but has been described in other organs. It is a rare but aggressive tumor and its prognosis is dismal. The longest survival time reported is 22 months. In our patient was 15 months. We treated at the National Cancer Institute of Panama a 52-year-old patient with oat-cell carcinoma of the esophagus and described his symptoms, pathology, treatment and results.

Carcinoma, Small Cell↗
PubMed1994

Three fatal cases of herbal aconite poisoning.

In 3 fatal cases of tachyarrhythmia caused by herbal poisoning, the only common denominator was the presence of aconites derived from the rootstocks and lateral root-tubers of Aconitum carmichaeli and the rootstocks of A kusnexoffii. The contain aconitine alkaloids which are notorious for the arrhythmogenic properties. Symptoms of these cases and management suggestions are presented.

Aconitum↗
PubMed1993

Contrasting effects of 17 beta-estradiol on the growth of human ovarian carcinoma cells in vitro and in vivo.

A human ovarian adenocarcinoma cell line (PE04) has been established as a xenograft in nude mice. In vitro, this cell line is estrogen receptor (ER)-positive and its growth is stimulated by 17 beta-estradiol at concentrations between 10(-12) and 10(-6) M. When xenografted, PE04 cells remain ER-positive and also possess progesterone receptors (PR); treatment with 17 beta-estradiol reduces the concentration of ER and increases levels of PR. Growth of the xenograft is reduced in ovariectomized animals while implantation of estrogen pellets also results in growth inhibition. Similar treatment with estrogen does not inhibit the ER-negative HOX 60 ovarian xenograft, and stimulates growth of the ER-positive ZR-75-I breast carcinoma xenograft. Serum measurements of 17 beta-estradiol confirm that ovariectomy reduces the level of 17 beta-estradiol while implantation of estrogen pellets results in raised levels of the hormone. Tamoxifen inhibits growth of the PE04 xenograft but not that of the HOX 60 xenograft, consistent with ER status. These results indicate that ER-positive PE04 ovarian cancer cells are sensitive to 17 beta-estradiol in vivo but that the response may be of a different type from the in vitro response. This lends further support to the concept that ovarian cancer may be hormone-sensitive and potentially responsive to endocrine therapy.

Adenocarcinoma↗