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Biomedical subjects

M Payne

Publications and source records attributed to M Payne.

At least 37 records · Page 2Linked to original sources
PubMed1998

Dermal uptake of solvents from the vapour phase: an experimental study in humans.

The control of exposure to hazardous substances in the workplace has traditionally focused on uptake via the inhalation route. Control of skin uptake has generally been considered for solids and liquids but the potential for uptake from vapours and gases has received relatively little attention. The current work was undertaken to establish a methodology to study the dermal uptake from vapours and to provide new and comparative information on a range of substance vapours. Groups of human volunteers were exposed to a small range of substances either 'whole body' or via the skin only. Substances (xylene, toluene, tetrahydrofuran [THF], methyl ethyl ketone [MEK] and 1-methoxypropan-2-ol [M2P]) were selected on the basis of their predicted dermal uptake from the vapour phase; their industrial use and potential for occupational exposure; the existence of a health-based occupational exposure limit; the availability of an analytical technique(s) for the substance and/or metabolite(s); and as representatives of chemical classes. Exposures were for four hours generally at the level of the UK Occupational Exposure Standard. Uptake was assessed by monitoring of parent or metabolite in blood, single breath or urine following exposure. Uptake of xylene, toluene and THF vapours via the skin under the conditions of this study was estimated to contribute around 1-2% of the body burden received following whole body (including inhalation) exposure. MEK showed more uptake via the skin, contributing around 3-3.5% of the body burden. Most dermal uptake was seen for the glycol ether M2P for which estimates of between 5-10% of whole body exposure body burden were obtained. The results of this and other studies indicate that uptake of vapours across the skin can occur but that for some substances (e.g., xylene, toluene, THF) this is likely to contribute little to the body burden. For other substances, such as the glycol ethers, skin uptake from vapours may be an important contributor to total uptake, particularly in situations where respiratory protective equipment is used to control inhalation exposure.

Administration, Cutaneous↗
PubMed1997

Giant cell arteritis--a case report.

Giant cell arteritis is a serious condition, requiring immediate treatment. A case illustrating the difficulties of diagnosis is presented, together with a discussion of the management.

Aged↗
PubMed1997

Unusual cause of pulmonary hypertension and congestive heart failure in a newborn.

Anomalous systemic arterial supply to a lobe of the lung is a rare cause of pulmonary hypertension and congestive heart failure in the newborn period. We report the presentation and successful treatment of a neonate with this unusual anatomy. Proper diagnosis required both echocardiography and aortography, and surgical resection of the involved lobe was curative.

Aorta↗
PubMed1997

Single case evaluation of the effects of aromatherapy and massage on disturbed behaviour in severe dementia.

Aromatherapy and massage could provide a useful addition to psychological therapeutic interventions with clients suffering from dementia. The effects of aromatherapy and massage on disturbed behaviour in four individuals with severe dementia were evaluated using a single-case research design. Each participant received 10 treatment sessions of aromatherapy, aromatherapy and massage combined, and massage alone. The effects on each individual's behaviour in the hour following treatment were assessed against 10 'no treatment' control sessions. Reliable individualized disturbed behaviour scales were designed. The effects of the treatments were mixed. The opinion of the staff providing treatment was that all participants benefited. On close scrutiny, only one of the participants benefited from the aromatherapy and massage to a degree that reached statistical significance. In two of the cases aromatherapy and massage led to an increase in agitated behaviour. The importance of the single case study approach with this client group is discussed.

Aged↗
PubMed1996

Specific cleavage of immunoglobulin G by copper ions.

The hinge region of a recombinant-DNA-produced human IgG1 (Campath 1H) is specifically cleavable at a single copper-sensitive peptide bond, yielding a distinct fragment resolved by size-exclusion high-performance liquid chromatography. This novel metal ion-catalysed cleavage at slightly alkaline pH is inhibited by EDTA and its rate is reduced at slightly acidic conditions (pH 5-6) and accelerated by increasing concentrations of cupric ion and higher temperature. Complete cleavage was observed after incubation at pH 8 for 24 h with 1 mM CuCl2. Sequence analysis determined the cleavage site to be the Lys226-Thr227 bond in the hinge-region sequence DKTHT. Cleavage of other IgGs was observed to varying degrees, and specific cleavage of synthetic peptides containing this pentapeptide sequence was also observed.

Alemtuzumab↗
PubMed1995

Prospective multicenter evaluation of an initially placed button gastrostomy.

Eight-six patients were prospectively evaluated following placement of the One-Step gastric button. Placement problems, most commonly caused by the stoma measurement device, were noted in 17%. In an additional 30% of patients, peristomal infection, leakage, or migration developed within the first 90 days of placement. The authors conclude that although this gastric button can be placed in the majority of patients, potential design and placement problems may produce significant intraprocedural and postprocedural complications.

Gastrostomy↗
PubMed1995

The effect of thin K-edge filters on the image quality of D- and E-speed dental film.

The use of K-edge filters and fast speed dental (non-screen) film have been separately shown to reduce the radiation dose imparted during dental radiography. The effect of these on image quality has been unclear. This study objectively examines the effect on image quality of eight film/filter systems: E- and D-speed film and four filter systems (the existing aluminium filter used alone or with erbium, niobium or yttrium). The components of the image quality parameters assessed were contrast, resolution, the minimum perceptible contrast (noise) and the square wave response function. No clinically significant difference in image quality was observed. This was confirmed by subjective assessment of images of an anatomical phantom. It is concluded that the use of faster speed film in addition to K-edge beam filtration has no major effect on the clinical image.

Filtration↗
PubMed1995

'Good prognosis tumours' in breast cancer screening.

The Forrest Report led to the introduction of the breast screening programme with the aim of reducing mortality from breast cancer. In 1989 a breast screening programme was introduced to the South Bucks District and now two cycles have been completed. The findings are of a high yield of good prognosis tumours 71% and 72%, respectively. These encouraging figures are reflected in a high response rate and with a fall in the incidence of non-screen-detected tumours.

Aged↗
PubMed1995

Development and use of ELISA to quantify type II phospholipase A2 in normal and uremic serum.

Previously we reported that uremic plasma contained eight times more phospholipase A2 (PLA2) activity than control plasma (Costello et al., Clin Chem 1990;36:198-200). That study, however, did not distinguish between various PLA2s that could contribute to the observed increase. Therefore, we developed a sandwich ELISA to specifically quantify serum type II PLA2. By ELISA, uremic sera contained significantly more type II PLA2 than control sera (median = 1025 micrograms/L, range = 52-3320 micrograms/L vs median = 9.2 micrograms/L, range = 4.6-17.5 micrograms/L; P = 0.002). When serum samples were incubated with 1-[14C]oleate-labeled autoclaved Escherichia coli, activity was increased 14.6-fold in uremic vs normal serum, with a median of 6.5 mumol/min per liter (range 1.1-16.3) vs a control median of 0.49 mumol/min per liter (range 0.32-0.60; P = 0.002). Thus, ELISA detects about eightfold more immunoreactive type II PLA2 in uremic serum than does enzymatic analysis. Evidently, the increase in PLA2 activity previously observed in uremic plasma is primarily due to increased concentrations of type II PLA2.

Antibodies, Monoclonal↗
PubMed1994

Brain choline in depression: in vivo detection of potential pharmacodynamic effects of antidepressant therapy using hydrogen localized spectroscopy.

1. Seven subjects with depression and matched controls were studied using proton spectroscopy to test the hypothesis that choline will be elevated in depression. 2. The proton spectroscopy was repeated after recovery from depression. 3. The study confirmed a state dependent increase in choline in the brain. 4. This change may be used as an in vivo marker of change in depression.

Aged↗
PubMed1994

Microalbumin excretion in patients with positive exercise electrocardiogram tests.

Thirty-three subjects underwent exercise electrocardiogram testing, 20 had a history of myocardial infarction and 13 were age-matched volunteers. Exercise electrocardiograms were positive in 15 subjects, negative in 12 and anomalous in six. Urinary microalbumin excretion was measured at rest, 30 and 60 min after exercise. Urinary microalbumin excretion was expressed as the albumin-creatinine ratio in mg.mmol-1. In the positive exercise electrocardiogram group median albumin-creatinine ratio increased from 1.0 mg.mmol-1 (95% CI 0.94-1.49) at rest to 2.0 mg.mmol-1 (95% CI 1.51-3.94) 30 min after exercise, whilst in the negative electrocardiogram group median resting and 30 min post exercise albumin-creatinine ratio values of 0.85 (95% CI 0.53-1.32) and 1.80 (95% CI 0.63-2.32) mg.mmol-1 respectively were not significantly different. These results suggest that exercise-induced myocardial ischaemia is associated with increased urinary microalbumin excretion.

Albuminuria↗
PubMed1993

Gingival swelling as a manifestation of non-Hodgkin's lymphoma.

A case is reported in which a 52-year-old male patient presented to his dental practitioner with several unusual, purple coloured gingival swellings, the largest of which was about 1 cm in diameter. A careful medical history revealed that the patient had 2 years previously been diagnosed as having low-grade non-Hodgkin's lymphoma (NHL). Prompt referral led to confirmation of the provisional diagnosis of gingival manifestation of NHL and early institution of appropriate treatment.

Gingival Neoplasms↗
PubMed1992

Murine cross-reactive T-cell epitopes of Neisseria meningitidis outer membrane proteins.

Five non-covalent vaccines of outer membrane proteins (OMPs) complexed to capsular polysaccharide were prepared from Neisseria meningitidis serogroup B strains. Each vaccine contained distinct serotype (class 2/3) and subtype (class 1) OMPs. The cross-reactivity of the T-cell response to the meningococcal vaccine-associated proteins was examined in an in vitro T-cell proliferative assay, following antigenic priming of mice with one of these vaccines (MB6:P1.6) or with its purified class 1 (subtype P1.6) and class 2 (serotype 6) proteins. Cross-reactive T-cell epitopes were found in all five vaccine preparations on both the class 1 and class 2/3 OMPs. Priming of mice with the subtype P1.6 N-terminal peptide led to a significant but small increase in T-cell proliferation with the MB6:P1.6 vaccine.

Amino Acid Sequence↗
PubMed1992

Selective reduction of creatine kinase subunit mRNAs in striated muscle of diabetic rats.

Creatine kinase (CK) is important for energy transfer and is composed of mitochondrial (mitCK), muscle (MCK), and brain (BCK) subunits, each being the product of separate nuclear genes. The concentrations of MCK and BCK mRNAs have been shown to decrease in streptozotocin-hypoinsulinemic rat hearts, and in this report, we examined in detail the diabetic effect on CK gene expression in cardiac muscle and in two types of skeletal muscle. The level of sarcomeric mitCK mRNA was not altered in the diabetic myocardium, but was reduced by 86 and 67% in diabetic slow-twitch soleus muscle and fast-twitch extensor digitorum longus (EDL) muscle, respectively. MCK mRNA was also lowered in diabetic soleus muscle by 56%, while it remained at control levels in diabetic EDL. In both skeletal muscles, at either state, BCK mRNA was not detectable. There was a 33% decrease in total CK activity in diabetic cardiac and soleus muscle, but not in EDL. Diabetes thus exerts a widespread, muscle type-dependent adverse effect on CK expression that we found to be insulin therapy revertible. This study adds to our understanding of defective energy transduction in diabetic muscle.

Animals↗
PubMed1991

The release of neuronal 5-HT from the intestine of a teleost fish, Platycephalus bassensis.

The superfused, isolated intestine of a teleost fish which lacks enterochromaffin cells spontaneously released 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), presumably from enteric neurons. The release of 5-HT, but not 5-HIAA, increased on transmural electrical stimulation. Addition of tetrodotoxin or omission of Ca2+ from the superfusate prevented the increase in 5-HT release on electrical stimulation. Fluoxetine added to the superfusate increased the amount of 5-HT released spontaneously but also prevented the increase in 5-HT release on stimulation. Pretreatment of fish with reserpine markedly reduced tissue levels of 5-HT and 5-HIAA and led to an almost complete loss of the spontaneous release of 5-HT and an elimination of the stimulated release of 5-HT.

Animals↗