PubMed Health⌕ Search

Biomedical subjects

J A Swift

Publications and source records attributed to J A Swift.

At least 19 recordsLinked to original sources
PubMed2006

Validation of a brief, reliable scale to measure knowledge about the health risks associated with obesity.

BACKGROUND: Obesity represents a serious threat to health through its association with conditions such as type 2 diabetes mellitus, coronary heart disease and certain types of cancer. Knowledge regarding risk to health is an important determinant of behaviour and is the focus of many health education strategies. To the authors' knowledge, there is no valid and reliable measure of knowledge regarding the health risks associated with obesity. AIM: To validate a short, reliable psychometric scale measuring knowledge regarding the effects of obesity on health, the Obesity Risk Knowledge (ORK-10) scale. METHODS: The ORK-10 scale was administered to a sample of individuals with no specific obesity-related expertise (n=230) and a sample of experts (n=200). Univariate and multivariate statistical analyses were used to investigate the scale's criterion validity. RESULTS: The ORK-10 scale has good internal consistency (Cronbach's alpha coefficient>0.7) and is acceptable for use in a UK adult population with an estimated reading age of 12-13 years. The scale demonstrated strong criterion validity, as those with educational or vocational expertise in the field of obesity achieved significantly higher scores than nonexperts (median 9.0 vs 4.0, Z=-17.364; P<0.001). This relationship was maintained after controlling for the potentially confounding factors of age and level of education. Nonexperts demonstrated low levels of knowledge regarding the health risks associated with obesity. CONCLUSIONS: The ORK-10 scale meets standard psychometric criteria for reliability and validity. This scale could be used to assess the effectiveness of health education interventions, to target the provision of health information and to investigate the interaction between knowledge and obesity-related behaviour.

Adolescent↗
PubMed2004

Hypertelorism, ptosis, and myopia associated with drug-resistant epilepsy, mental delay, growth deficiency, ectodermal defects, and osteopenia.

We report a 30-year-old woman with hypertelorism, ptosis, and myopia associated with drug-resistant epilepsy (DRE, Lennox-Gastaut syndrome), mental delay, growth deficiency, ectodermal defects, and osteopenia. To the best of our knowledge, this patient has an unusual combination of symptoms not previously described, associated with severe central nervous system dysfunction. The ectodermal defects were present in a very intriguing form, were difficult to diagnose, and did not conform to any classification or previous description.

Adult↗
PubMed2002

Lamellar subcomponents of the cuticular cell membrane complex of mammalian keratin fibres show friction and hardness contrast by AFM.

There is a substantial body of information indicating that 18-methyleicosanoic acid (18-MEA) is covalently linked to the outer surface of all mammalian keratin fibres and also forms the outer beta-layer of the cuticular cell membrane complex (CCMC) which separates the cuticle cells from each other. Low cohesive forces are expected between the lipid-containing outer beta-layer and the delta-layer of the CCMC, thus providing a weak point for cuticular delamination and presenting a fresh layer of 18-MEA to the newly exposed surface. We have used lateral force microscopy and force modulation atomic force microscopy (AFM) to examine human hair fibres in which the non-covalently linked fatty acids have been removed. Examination of the lateral force images of new cuticle surfaces revealed by the attrition of overlying cuticle layers showed three separate zones of clearly defined frictional contrast. These are thought to correspond with the delta-layer, the proteinaceous epicuticle and outer beta-layers of the CCMC. The delta-layer was found to have a thickness of 16 nm (SD = 1 nm, n = 25), comparable to the 18.0 nm thickness measured from transverse cross-sections of fibres with transmission electron microscopy. Force modulation AFM showed that the outer beta-layer was softer than the epicuticle and the delta-layer. The frictional contrast was removed following treatment with methanolic KOH (0.1 mol dm-3) at 25 degrees C for 30 min, suggesting the hydrolysis of the thioester linkage and removal of 18-MEA from the surface.

Animals↗
PubMed2001

Metric engineering of soft molecular host frameworks.

The self-assembly and solid-state structures of host-guest inclusion compounds with lamellar architectures based on a common building block, a resilient hydrogen-bonded sheet consisting of guanidinium ions and sulfonate moieties of organodisulfonate "pillars", are described. The pillars connect adjacent sheets to generate galleries with molecular-scale cavities occupied by guest molecules. The size, shape, and physicochemical character of the inclusion cavities can be systematically adjusted by interchanging framework components while maintaining the lamellar architecture, enabling prediction and control of crystal lattice metrics with a precision that is unusual for "crystal engineering". The reliability of the lamellar architecture is a direct consequence of conformational flexibility exhibited by these hosts that, unlike rigid systems, enables them to achieve optimal packing with guest molecules. The adaptability of these hosts is further reflected by an architectural isomerism that is driven by guest templating during assembly of the inclusion compounds. Host frameworks constructed with various pillars display metric interdependences among specific structural features that reveal a common mechanism by which these soft frameworks adapt to different guests. This unique feature facilitates structure prediction and provides guidance for the design of inclusion compounds based on these hosts.

Molecular Structure↗
PubMed2001

Microscopical investigations on the epicuticle of mammalian keratin fibres.

The existence of a thin chemically resistant layer, the epicuticle, close to the surfaces of all undamaged mammalian keratin fibres has been known since 1916. The identification of such a specific structure within the fibre cuticle has remained elusive. Now, through transmission electron microscope investigations of stained transverse sections of hairs from various animal species, the epicuticle has been tentatively identified as a sharply defined and continuous layer approximately 13 nm thick covering the entire outwardly facing intracellular surface of every cuticle cell. The staining behaviour of the epicuticle leads one to suppose that it is rich in cystine and that thioester-bound lipids might be present within its bulk. With the atomic force microscope it was established that the undamaged outer surface of all mammalian keratin fibres, even including those from the monotremes, were longitudinally striated. The lateral spacing of the striations was always in the range 0.29-0.39 microm. Striations only occurred on the freely exposed outer surfaces of the original undamaged fibres; evidently arising by some, as yet undefined, interaction in the follicle with the cuticle of the inner root sheath. By stripping off fatty acids known to be covalently attached to the fibre's outer surface, the striations were shown to reflect a corresponding irregularity of the epicuticle's surface.

Animals↗
PubMed1999

Stereoscopic display of atomic force microscope images using anaglyph techniques.

This paper describes the use of a standard stereo-pair image display method for presenting the three-dimensional relief information found in atomic force microscope (AFM) images. The method makes use of commercially available image processing software packages. The techniques are illustrated on AFM images of the cuticle structure of a human hair fibre.

Hair↗
PubMed1997

Morphology and histochemistry of human hair.

This chapter is concerned with the structure of the mature human hair shaft and the chemical composition of its subcomponents as adduced from the examination of fibres mainly with the conventional transmission electron microscope (TEM). The broad outlines of the techniques used in the study of hair are reviewed, with particular attention being paid to the processes of chemical staining which enable one to define various aspects of the chemical composition of the hair's microscopic sub-components. Against this background the internal structure of normal undamaged hair is described.

Carboxylic Acids↗
PubMed1981

Monilethrix: an electron microscopic and electron histochemical study.

We have carried our electron microscopic and electron histochemical investigations on affected hair follicles and hair shafts to elucidate further the structural abnormality in monilethrix. The structural abnormalities manifest in the cortex and cuticle of the hair shaft could be traced to the locality of the 'zone of keratinization' of the follicle. Abnormal orientation of the cortical cell proteins, folding of the cuticle cell membrane and varying amounts of endocuticular material were all observed in the region prior to full keratinization. We observed structural abnormalities within all the component layers of the inner root sheath adjacent to the faults within the hair shaft, indicating a possible asynchrony within the monilethrix follicle.

Hair↗
PubMed1975

A technique for obtaining scanning electron micrographs in colour.

A digital electronic unit is described which, by modifying the video signal of the scanning electron microscope (SEM), permits the selection of images in separate tonal or grey-scale levels. By the sequential exposure of these grey levels onto colour film with the intervention of colour filters, coloured scanning electron micrographs have been obtained. Full details of the procedure are given. The process is applicable to any normal image capable of being displayed at the scanning electron microscope.

Animals↗