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Biomedical subjects

M Lowry

Publications and source records attributed to M Lowry.

At least 19 recordsLinked to original sources
PubMed1996

Quantification of citrate concentration in the prostate by proton magnetic resonance spectroscopy: zonal and age-related differences.

A commercial phased-array multicoil was used to acquire water-suppressed localized proton spectra of the two major anatomical regions of the prostate. The signal-to-noise ratio and spectral resolution allowed identification of peaks from choline and creatine, as well as a major peak from citrate. Quantification of the citrate peak using experimentally determined relaxation parameters with tissue water as an internal concentration reference revealed a marked variability between different volunteers. Nevertheless, in each case, the citrate concentration was up to fourfold greater in the peripheral zone than in the central gland. Furthermore, the difference in citrate concentration between these two regions was positively correlated with the subjects age. The results indicate a consistent difference in cellular function between the major anatomical regions within the prostate and may have important consequences for the application of magnetic resonance spectroscopy to the diagnosis of prostatic pathology.

Adult↗
PubMed1995

Determination of proton metabolite concentrations and relaxation parameters in normal human brain and intracranial tumours.

Quantitative proton spectroscopic studies were performed on 39 volunteers and 16 patients with intracranial tumours. Estimates of T2 were obtained in white matter, grey matter, cerebellum, astrocytomas and meningiomas; T1 was determined in white matter only. White matter values of T2 for trimethylamines, creatine and N-acetyl aspartate (NAA) were 309 +/- 84, 195 +/- 41 and 369 +/- 124 ms, respectively (mean +/- SD, n = 20). Metabolite concentrations in white matter were 2.0 +/- 0.4 mumol/g wet weight for trimethylamines, 7.3 +/- 1.1 for creatine and 11.4 +/- 1.4 for NAA. The mean concentrations of creatine and NAA in grey matter and all of three metabolites in cerebellum were greater than those in white matter. Tumour spectra were characterized by increased trimethylamines, reduced creatine and NAA and occasionally the presence of lactate. Meningiomas were further characterized by the presence of alanine. The mean T2 and concentration of trimethylamines in tumours was significantly greater than in normal brain. Creatine and NAA concentrations were decreased in all tumours. The longer T2 of trimethylamines and presence of alanine in meningiomas indicate that important differences exist in membrane and glucose metabolism within these tumours when compared to either astrocytomas or normal brain tissue.

Aspartic Acid↗
PubMed1995

Quality assessment in in vivo NMR spectroscopy: IV. A multicentre trial of test objects and protocols for performance assessment in clinical NMR spectroscopy.

A multicentre trial of test objects and protocols for performance assessment in single volume and slice selective magnetic resonance spectroscopy (MRS) was conducted by the European Community Concerted Action on MRI and MRS. The trial assessed phosphorus and proton localisation techniques implemented on commercially available MR systems at ten sites in Europe. At each site, a number of parameters devised by the Concerted Action were measured using prototype test objects. Some of these parameters related to the quality of localisation and others to the overall performance of the spectrometer. Results were obtained for the ISIS, DRESS, STEAM, and PRESS sequences with a range of acquisition parameters, allowing evaluation of the assessment methodology and comparison of the efficacy of various implementations of these localisation techniques. The results of this trial have been important in the development of the Concerted Action's final recommendations for MRS performance assessment, and demonstrate that such assessment provides valuable information in the comparison of spectroscopy data from different sites and in the development of new localisation sequences, and provides a means of quality assurance in MRS.

Magnetic Resonance Spectroscopy↗
PubMed1995

Evaluating a patient teaching programme.

Patient teaching is an essential element of care that should involve the multidisciplinary team. Patients and their significant others must have access to patient teaching programmes in order that they may make informed choices. The design of the programme must be considered carefully in order to meet the needs of patients and their significant others. Patients clearly benefit from well-organised and appropriately planned patient teaching programmes.

Health Services Needs and Demand↗
PubMed1995

Knowledge that reduces anxiety. Creating patient information leaflets.

1. Patient information is an essential ingredient of caring, which needs to be both carefully considered and consistent. 2. Creating information leaflets should be a collaborative effort, involving members of the multidisciplinary team. 3. There are demonstrable benefits in providing information for patients, including compliance and patient empowerment. 4. Team working is enhanced by having common understandings. It also improves interdisciplinary communication. 5. There are cost benefits in taking time to produce good quality patient information leaflets.

Anxiety↗
PubMed1994

Phosphorus-31 metabolism of post-menopausal breast cancer studied in vivo by magnetic resonance spectroscopy.

We have studied the metabolism of 31P-containing metabolites of post-menopausal breast cancers in vivo using magnetic resonance spectroscopy (MRS) and a 5.5 cm surface coil. Spectra were acquired from 23 diameter. The spectra of the 19 previously untreated tumours had significantly higher phosphomonoester (PME) 31P relative peak areas than the normal breasts of eight post-menopausal women (11.7% and 7.7% respectively, P = 0.002). Although an increased PME relative peak area was characteristic of malignancy, PME relative peak area is similarly raised in lactating breast and, therefore, not a specific feature of cancer. An apparently lower nucleotide triphosphate (NTP) relative peak area in tumours than healthy postmenopausal breast was secondary to the differences in PME relative peak area; contamination by signal from chest wall muscle probably accounts for the ostensibly higher phosphocreatine (PCr) relative peak area of the tumours. Spectroscopy was repeated following chemotherapy in six women. An increase in PCr relative peak area was seen in all five patients who responded, but again this may represent increased contamination secondary to changes in tumour size. A fall in PME relative peak area was noted in four responders, but also one non-responder, so this finding may not be sufficiently specific to be of use clinically. Further studies are need to elucidate fully the role of MRS in breast cancer.

Adult↗
PubMed1994

Trisomy 12 mosaicism in a 7 year old girl with dysmorphic features and normal mental development.

We present the case of a mentally normal 7 year old girl with short stature, scoliosis, atrial septal defect, and dysmorphic features including linear pigmented streaks on the forearms and lower legs. Chromosome analysis of cultured fibroblasts showed trisomy 12 in 9% and 13% of cells from two skin biopsies. Two trisomy 12 cells were found in lymphocytes after analysis of 500 metaphases. Her clinical features are compared with those of other liveborn cases of trisomy 12 mosaicism and the problems of prenatal diagnosis of such an abnormality are discussed.

Abnormalities, Multiple↗
PubMed1994

Phosphorus-31 metabolism of human breast--an in vivo magnetic resonance spectroscopic study at 1.5 Tesla.

We have studied the metabolism of compounds containing 31P in normal breast using magnetic resonance spectroscopy (MRS). Spectra were acquired from non-lactating pre-menopausal breast (n = 14 women), lactating breast (n = 8) and post-menopausal breast (n = 8). The standard acquisition protocol used a 5.5 cm surface coil with the volunteer prone to minimize chest wall signal contamination. In pre-menopausal non-lactating women the phosphocreatine (PCr) peak area, expressed relative to the sum of all 31P peak areas, was negatively correlated with breast size (r = -0.56, p = 0.02) suggesting that much of the PCr signal originated from the chest wall. The phosphodiester (PDE) relative peak area was positively correlated with breast size (r = 0.71; p = 0.002). Spectra could be acquired at all phases of the menstrual cycle. In sequential examinations of five women not taking the oral contraceptive pill (OCP), phosphomonoester (PME) relative peak area was significantly lower on Week 2 than other weeks of the cycle (p = 0.03). Among pre-menopausal women no clear difference was apparent between the spectra from women taking the OCP and those not taking the OCP. Lactating breast had significantly higher PME relative peak area than non-lactating pre-menopausal breast (p = 0.02), probably reflecting the higher proportion of epithelial tissue in lactation; the lower PCr relative peak area in lactating breast (p = 0.05) is probably due to the greater size of the breast during lactation. Spectra were acquired from post-menopausal women but with a relatively low signal-to-noise ratio. The only significant difference between 31P relative peak areas of breast spectra acquired from pre- and post-menopausal women was that less PCr was detected in the post-menopausal volunteers (p = 0.03), probably as a result of differences in breast size.

Breast↗
PubMed1993

Infant feeding practices.

This study was done on a population of 877 mothers over a five month period. Interviews were held on the first day after delivery and on the day of discharge. Mothers were questioned on their infant feeding practice and on the influences which led them to their choice of feed types. Follow up studies were done in subsequent months on randomly selected populations of breast feeders (103) and bottle feeders (170) to determine duration of breast feeding after discharge from hospital; the factors contributing to cessation of breast feeding; the measure of satisfaction with the brand initially chosen and the factors which caused mothers to change from one brand to another. The salient finding is that 36% breast feed initially and that up to 10% of the total are still doing so five months later. The other findings are discussed and their significance stated.

Bottle Feeding↗