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Biomedical subjects

P J Turnbull

Publications and source records attributed to P J Turnbull.

8 recordsLinked to original sources
PubMed2002

Evaluation of nutritional status and its relationship with functional status in older citizens with diabetes mellitus using the mini nutritional assessment (MNA) tool--a preliminary investigation.

BACKGROUND: Despite all that is known about diabetes mellitus, little is known about the nutritional status of older adults with this condition. OBJECTIVE: To determine whether older people with diabetes mellitus are malnourished when compared with non-diabetic subjects, to evaluate the MNA in this group, and to assess the possible relationship between nutritional impairment and function. DESIGN: A case controlled study. Community-dwelling volunteers were selected randomly from 2 general practice registers. 35 people over the age of 65, with diabetes mellitus, were age and sex matched with 35 control subjects without diabetes. The major outcome measures were: the MNA questionnaire, anthropometric measurements, serum albumin, transferrin, Barthel Index, Nottingham Extended ADL score and handgrip. RESULTS: The diabetic group scored significantly lower on the MNA than the control group (p< 0.01), but this was mainly indicative of many of the diabetic subjects scoring within the at risk category of the tool. Those in the diabetic group also had significantly lower albumin scores (P<0.05) when compared with the control group. Within the diabetic group, and in the study group as a whole, the MNA scores were significantly correlated with Barthel Index (p<0.01), Nottingham Extended ADL score (p<0.01) and handgrip (p<0.01). CONCLUSION: Community dwelling elderly subjects with diabetes may be at risk of malnutrition when compared with non-diabetic citizens. There is probably a causal relationship between malnutrition and functional decline in this group. Further research is needed, where the prevalence of malnutrition is higher, to fully evaluate the MNA in people with diabetes.

Activities of Daily Living↗
PubMed1996

Peptides modeled on the transmembrane region of the slow voltage-gated IsK potassium channel: structural characterization of peptide assemblies in the beta-strand conformation.

A 27-residue peptide, having a sequence corresponding to the transmembrane domain of the IsK protein with slow voltage-gated potassium channel activity, has been incorporated into synthetic saturated-chain phospholipid membranes. The peptide-lipid complexes have been characterized by attenuated-total-reflection Fourier-transform-infrared spectroscopy (ATR-FTIR), spin-label electron spin resonance (ESR) spectroscopy, 31P and 2H nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and low-angle X-ray diffraction. From FTIR spectroscopy, it is found that, when reconstituted into membranes by dialysis from 2-chloroethanol, the peptide has a predominantly beta-strand secondary structure in which the peptide backbone is oriented at an angle of approximately 56 degrees relative to the membrane normal in dry films of phosphatidylcholines. Hydration of the dry film in the gel phase does not appear to affect the orientation of the peptide backbone, and a relatively small change in orientation occurs when the bilayer undergoes the transition to the fluid phase. The ESR and NMR spectra from spin-labeled and 2H-labeled phospholipids, respectively, indicate that the incorporated peptide restricts the rotational motion of the lipids, without appreciably affecting the chain order, in a way similar to that found for integral membrane proteins. The characteristic two-component ESR spectra from spin-labeled lipids further indicate a selectivity in the interaction of anionic phospholipids with the peptide. The motional restriction of the chains of the spin-labeled phosphatidylcholine and the reduction in the enthalpy of the lipid chain-melting transition indicate that, on average, approximately two to three phospholipid molecules interact directly with each peptide monomer, which is consistent with a limited degree of aggregation of the beta-sheet structures. Both 31P NMR spectroscopy and X-ray diffraction indicate that the lipid-peptide complexes have a lamellar structure up to the highest peptide concentration studied (Rp = 0.2). The surface area occupied by lipid molecules (ca. 30 A2 per chain) in the peptide complexes, deduced from the lamellar repeat spacings at defined water content, is very similar to that in pure fluid lipid bilayers, consistent with the 2H NMR results. The additional membrane surface area contributed by the peptide is approximately 112 A2 per monomer. This large value for the peptide area in the fluid bilayer is consistent with the ATR studies of dry peptide/lipid films which suggest that the long axis of the beta-strand is strongly tilted with respect to the bilayer normal (56 degrees in the dry film).

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1996

"Just using old works": injecting risk behaviour in prison.

A minority of injecting drug users engage in high risk injecting behaviours when in prison. In the United Kingdom between a quarter and a third of injectors who enter prison inject when in prison, and of these about three-quarters share needles and syringes. In the present study, 44 drug injectors who had been released from prison for no longer than 6 months were recruited and interviewed in three geographical areas in England. Interviewees were asked to recount their experiences of drug use during their most recent period of imprisonment. The majority of interviewees were male (38/44), had a mean age of 28 years, with a mean age of 16 years at first drug use, were primarily opiate users (39) and had multiple imprisonments. All respondents reported drug use when imprisoned and drug injecting was reported by 16 interviewees. Most injected at irregular intervals and at a reduced level, compared with injecting when in the community. Nine reported using needles and syringes that others had previously used. When considering other injecting equipment, more sharing occurred than was actually reported. Much re-use of equipment was viewed simply as "using old works". The sharing of "cookers" and "filters", and drug sharing by "backloading" and "frontloading" were common. The concept of "sharing" tended to be understood by respondents as related to the use of tools of injection (needles and syringes rather than other equipment); the use of tools in the act of injection (rather than for mixing drugs); proximity (multiple use of needles and syringes in the presence of others); temporality (shorter time elapse between consecutive use of needles and syringes previously used by another) and source (hired rather than borrowed or bought). We conclude that syringe sharing is an integral part of drug use and drug injecting in prison. Many of those interviewed displayed a restricted understanding of what denotes syringe sharing. Our data reinforce the need for interventions and initiatives to be developed within prisons to deal with the considerable risk posed by continued injecting drug use.

Journal Article↗
PubMed1996

Characterization of the gene encoding core protein VP6 of two African horsesickness virus serotypes.

The genes encoding the inner core protein VP6 of African horsesickness virus (AHSV) serotypes 3 and 6 have been cloned and sequenced. The genes are 1169 nucleotides in length and both encode a largely hydrophilic protein of 369 amino acids. The VP6 amino acid sequence is highly conserved between the two serotypes with an overall similarity of 95 percent. Comparison of the AHSV VP6 amino acid sequences with those of bluetongue virus serotype 10 VP6 revealed that it is 41 amino acids longer with an overall amino acid identity of 29 percent. The similarity is mainly confined to a short but highly conserved 13 amino acid region at the N terminus, a short seven amino acid region at the C terminus and a 22 amino acid region close to the C terminus. Within this last region is a smaller 11 amino acid region from 318 to 328 with a 91 percent similarity to the Rep helicase of Escherichia coli.

African Horse Sickness Virus↗
PubMed1993

HIV testing, and the care and treatment of HIV positive people in English prisons.

In a study of 452 ex-prisoners in England in 1990, 66 people reported that they were tested for HIV antibodies when last in prison. The circumstances under which many of those who were tested were difficult: 36% found it an unpleasant experience, 17% had not taken the test voluntarily and 55% said they received no counselling. Further information was gathered about the experiences of those who were HIV positive or assumed to be. Most were accommodated in a 'special location', not allowed to associate with other prisoners and denied access to work or recreational facilities. These data highlight the difficulties arising from the policy of Viral Infectivity Restrictions, a set of regulations applied to the management of prisoners with HIV in English prisons. This policy created a distressing situation for those tested for HIV or identified as being HIV positive in prison. For the prison environment, these conditions may create a vicious circle reinforcing inaccurate beliefs and anxieties.

AIDS Serodiagnosis↗
PubMed1992

The conformational behaviour of phosphatidylinositol in model membranes: 2H-NMR studies.

Dimyristoylphosphatidylinositol (DMPI) has been synthesized with the appropriate natural stereochemistry and labelled with deuterium at specific sites in the D-myo-inositol headgroup. 2H-NMR spectroscopy of DMPI in its lamellar phase at a molar ratio of water-to-lipid RW/L of 129 and at 70 degrees C reveals quadrupolar splittings delta v of 3.83 and 2.17 kHz, respectively, for the five axially oriented C-D bonds and the single equatorially oriented C-D bond of the D-myo-inositol headgroup. Between RW/L ratios of 129 and 210 and between 30 degrees C and 80 degrees C the value of the ratio of these splittings delta nu ax/delta nu eq varies significantly (between 1.17 and 4.38). If it is assumed that, at a particular temperature, there is a single preferred orientation of the inositol headgroup, and that motion of the DPMI molecule establishes axial symmetry with respect to the bilayer normal then the ratio of these quadrupolar splittings can be used to impose constraints on that orientation. For example, the data are inconsistent with a situation in which the inositol ring lies parallel to the membrane surface and are difficult to reconcile with an arrangement where the inositol ring lies perpendicular to the surface. Computational modelling identifies four possible 'tilted' orientations, all of which are consistent with the data, and two of these allow good intramolecular hydrogen bonds to be formed. In one there is hydrogen bonding between the inositol C2-OH and the phosphate pro-R oxygen. This is close to the conformation previously identified as being dominant in DMSO solution (Bushby, R.J., Byard, S.J., Hansbro, P.M. and Reid, D.G. (1990) Biochim. Biophys. Acta 1044, 231-236).

Chemical Phenomena↗