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Gupta M, Shennan AH, Halligan A, Taylor DJ, de Swiet M. Accuracy of oscillometric blood pressure monitoring in pregnancy and pre-eclampsia. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1997; 104:350-5. [PMID: 9091015 DOI: 10.1111/j.1471-0528.1997.tb11467.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To assess the accuracy of the Omron HEM 705 CP oscillometric device for the measurement of blood pressure in pregnancy and pre-eclampsia. SETTING Two teaching hospitals. PARTICIPANTS Eighty-five pregnant women with a wide range of blood pressures, and 43 women with pre-eclampsia. METHODS Evaluation was carried out according to the British Hypertension Society protocol, incorporating criteria of the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS Mean differences (device minus observer) for systolic blood pressure were -0.9 mmHg (SD 10) in normal pregnancy, and -2 mmHg (SD 10) in the women with pre-eclampsia. For diastolic blood pressure, Korotkoff phase V, the differences were -1.5 mmHg (SD 10), and -8 mmHg (SD 8) respectively; i.e. the device consistently under-read the diastolic blood pressure in pre-eclamptic women by a mean of 8 mmHg when compared with conventional sphygmomanometry. Korotkoff phase IV could not be accurately reproduced. According to the British Hypertension Society grading criteria, the device reached a 'B' grading in the 85 pregnant women. In pre-eclampsia only a 'C' grade was reached for systolic blood pressure, and 'D' grade for diastolic blood pressure. Accuracy criteria stipulated by the AAMI were not met in any situation. CONCLUSION The Omron HEM 705 CP does not reach acceptable accuracy criteria for blood pressure measurement when compared with trained observers in women with pre-eclampsia, as judged by the British Hypertension Society Protocol. It also failed to meet the AAMI criteria, although the methodology stipulated by the AAMI may not be applicable to a pregnancy population.
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Irish AB, Thompson CH, Kemp GJ, Taylor DJ, Radda GK. Intracellular free magnesium concentrations in skeletal muscle in chronic uraemia. Nephron Clin Pract 1997; 76:20-5. [PMID: 9171295 DOI: 10.1159/000190135] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Low intracellular free magnesium concentrations ([Mg2+]i) are associated with essential hypertension and may reflect a disordered cellular ionic environment. 31P magnetic resonance spectroscopy was used to study skeletal muscle [Mg2+]i in a group of chronic renal failure (CRF) patients and data were compared with a group of control subjects of similar age. Other data including the patients' blood pressure, medication and plasma biochemistry were collected. There was a significant inverse correlation of [Mg2+]i with systolic (p < 0.001) and diastolic blood pressure (p < 0.05) in the CRF population. In CRF [Mg2+]i was similar (0.52 +/- 0.01 mM, SEM) to controls (0.53 +/- 0.01 mM; p = 0.20), even if just the normotensive patients and controls were compared. There was no correlation of [Mg2+]i with plasma parathyroid hormone, total [Mg2+] or [Ca2+]. Similar to studies in subjects with essential hypertension, these data support a role for [Mg2+]i specifically, and an abnormal intracellular environment more generally, in the pathophysiology of hypertension in CRF.
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McParland P, Halligan AW, Taylor DJ, Naftalin NJ. Laparoscopic laser treatment for endometriosis. Gynecol Obstet Invest 1997; 44:38-40. [PMID: 9251952 DOI: 10.1159/000291406] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The advent of the use of laparoscopy and lasers in gynaecology has added a further option for the treatment of endometriosis. This study is a retrospective review of the notes of 28 women who had endometriosis treated laparoscopically with an Nd:YAG laser. Results were assessed by subjective reporting of symptoms. Seventy-three percent of patients reported significant or complete resolution of symptoms at three to 26 months follow-up. No major complications were encountered. The results suggest this offers a further treatment option for endometriosis which merits further evaluation.
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Peek M, Shennan A, Halligan A, Lambert PC, Taylor DJ, De Swiet M. Hypertension in pregnancy: which method of blood pressure measurement is most predictive of outcome? Obstet Gynecol 1996; 88:1030-3. [PMID: 8942848 DOI: 10.1016/s0029-7844(96)00350-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine the clinical effectiveness of blood pressure (BP) measurement using conventional sphygmomanometry in the antenatal clinic and obstetric day unit compared with automated BP monitoring at home. METHODS The study population consisted of 109 nulliparous white women with BPs of at least 140 or 90 mmHg at the antenatal clinic after 20 weeks' gestation, who underwent obstetric day unit and 24-hour automated BP monitoring on the same day. Automated measurement was obtained every half hour for 24 hours using a commercially available device that had been previously validated in pregnancy. RESULTS At the traditional BP cutoff point (140/90 mmHg), the relative risk for subsequent development of adverse obstetric outcome was greatest for automated BP measurement: The relationships between outcome and automated diastolic BP were all statistically significant: proteinuria (P = .034), preterm delivery (P < .001), birth weight below the tenth percentile (P = .001), admission to the special care neonatal unit (P = .001), and cesarean delivery (P = .007). CONCLUSION Automated BP measurement appears to improve the identification of patients who are at high risk of poor obstetric outcome. Automated BP measurement is worthy of further evaluation as an antenatal screening and diagnostic test.
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Konje JC, Taylor DJ, Rennie MJ. Application of ultrasonic transit time flowmetry to the measurement of umbilical vein blood flow at caesarean section. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1996; 103:1004-8. [PMID: 8863699 DOI: 10.1111/j.1471-0528.1996.tb09551.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To determine the applicability of ultrasonic transit time flowmetry to the measurement at caesarean section of umbilical vein blood flow rate and to examine the relationship between flow rates and birthweight for gestational age. DESIGN Umbilical vein blood flow was measured at caesarean section using a transonic time flow probe on a loop of the umbilical cord in 33 appropriate and 21 small for gestational age fetuses. RESULTS The mean (SD) umbilical vein blood flow in the 54 fetuses was 78.4 (23.1) ml kg-1 min-1. There was a linear relation between umbilical vein blood flow measured by ultrasonic transit time flowmetry and birthweight (r = 0.63, P < 0.0001). The mean umbilical vein blood flow in appropriate for gestational age fetuses [90 (18) ml kg-1 min-1] was greater than that in the small for gestational age group [66 (23) ml kg-1 min-1], P < 0.04). CONCLUSIONS Umbilical vein blood flow measurements obtained by the ultrasonic transit time flowmetry technique are simple to perform and compare well with reported values obtained by the Doppler ultrasound technique (when vessel diameter is greater than 4 mm). Umbilical venous blood flow rate is significantly lower in small for gestational age fetuses.
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Thompson CH, Kemp GJ, Sanderson AL, Dixon RM, Styles P, Taylor DJ, Radda GK. Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers. Br J Sports Med 1996; 30:222-5. [PMID: 8889115 PMCID: PMC1332335 DOI: 10.1136/bjsm.30.3.222] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To examine the effect of a relatively low dose of creatine on skeletal muscle metabolism and oxygen supply in a group of training athletes. METHODS 31P magnetic resonance and near-infrared spectroscopy were used to study calf muscle metabolism in a group of 10 female members of a university swimming team. Studies were performed before and after a six week period of training during which they took either 2 g creatine daily or placebo. Calf muscle metabolism and creatine/choline ratios were studied in resting muscle, during plantar flexion exercise (10-15 min), and during recovery from exercise. RESULTS There was no effect of creatine on metabolite ratios at rest or on metabolism during exercise and recovery from exercise. Muscle oxygen supply and exercise performance were not improved by creatine if compared to placebo treated subjects. CONCLUSIONS Oral creatine supplementation at 2 g daily has no effect on muscle creatine concentration, muscle oxygen supply or muscle aerobic or anaerobic metabolism during endurance exercise.
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Konje JC, Bell SC, Morton JJ, de Chazal R, Taylor DJ. Human fetal kidney morphometry during gestation and the relationship between weight, kidney morphometry and plasma active renin concentration at birth. Clin Sci (Lond) 1996; 91:169-75. [PMID: 8795440 DOI: 10.1042/cs0910169] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1. This study was designed to examine the changes in kidney morphometry during gestation in fetuses that were either appropriate or small for gestational age and the relationship between umbilical vein plasma active renin and kidney morphometry. 2. Serial ultrasound measurements of various morphometric and renal indices were performed in a cohort of 87 singleton fetuses from 22 to 38 weeks gestation. Blood was collected from the umbilical vein at delivery and active renin was measured from the plasma based on angiotensinogen I generated during incubation with plasma and ox renin substrate. 3. Growth in the longitudinal plane of fetal kidneys was similar in the small- and appropriate-for-gestational age groups; however, growth in the anterio-posterior, transverse and circumference planes of the kidneys was significantly slower in the small-for-gestational-age group after 26 weeks gestation. Differences in growth rate in the two groups were most marked between 26 and 34 weeks and persisted until delivery when the anterior-posterior diameter was significantly larger (P < 0.00001) in the appropriate-for-gestational-age group (26.1 +/- 2.5 mm compared with 19.8 +/- 2.6 mm). The mean umbilical vein active plasma renin concentration at delivery was significantly higher (P < 0.05) in the small-for-gestation-age group (274.4 +/- 32.9 mu-units/ml plasma) than in the appropriate-for-gestational-age group (164.9 +/- 28.3 mu-units/ml plasma). In addition, there were statistically significant inverse correlations between renin concentration and birthweight (r = -0.55, P < 0.001) and between renin concentration and kidney anterior-posterior diameter (r = -0.67, P < 0.001). 4. Fetal renal growth was slower in small than in appropriate-for-gestational-age fetuses. The period of 26-34 weeks gestation was that during which maximum fetal renal growth occurred. Umbilical vein plasma renin levels were higher in small-for-gestational-age fetuses. The findings of slow fetal renal growth rate and associated high renin concentrations seen in small-for-gestational-age fetuses could be implicated in an irreversible reno-vascular pathology leading to adult hypertension. We suggest that 26 to 34 weeks could be the "critical period' during which the insult that leads to in-utero programming for the development of adult hypertension occurs.
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Malak TM, Sizmur F, Bell SC, Taylor DJ. Fetal fibronectin in cervicovaginal secretions as a predictor of preterm birth. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1996; 103:648-53. [PMID: 8688390 DOI: 10.1111/j.1471-0528.1996.tb09832.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine whether fetal fibronectin detected in cervicovaginal secretions of patients with symptoms suggestive of preterm labour is a predictor for preterm birth. DESIGN A blind prospective observational study. SETTING A teaching hospital. PARTICIPANTS One hundred and forty-one women presenting to the delivery suite between 24 and 37 weeks of gestation (112 were between 24 and 34 weeks of gestation) with symptoms suggestive of preterm labour, with intact membranes and cervical dilation of < 2 cm. INTERVENTION Specimens of cervicovaginal secretions were collected from the ectocervix and posterior fornix. Fetal fibronectin levels were measured by an ELISA and samples were considered positive if the level of fetal fibronectin present was > or = 0.05 microgram/ml. MAIN OUTCOME MEASURES Gestation at birth and sampling-birth interval. RESULTS The preterm birth (before 37 weeks of gestation) rate in the population studied was 19.1%. Fetal fibronectin predicted preterm birth with sensitivity of 63%, specificity of 95.6%, positive predictive value of 77.3%, and negative predictive value of 91.6%. Analysis of the data from women at less than 34 weeks of gestation showed similar results. A negative test accurately excluded (97.9%) the chance of subsequent birth during the three weeks interval following sampling. CONCLUSIONS The presence of fetal fibronectin in the cervicovaginal secretions of women admitted with symptoms suggestive of preterm labour indicates a significant risk for subsequent preterm birth. The absence of fetal fibronectin in this group is a very strong indication that subsequent preterm birth is unlikely to occur. Fetal fibronectin test, if combined with clinical findings, has a potentially important role in clinical management of women with symptoms suggestive of preterm labour.
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Thompson CH, Irish A, Kemp GJ, Taylor DJ, Radda GK. Skeletal muscle metabolism before and after gemfibrozil treatment in dialysed patients with chronic renal failure. Clin Nephrol 1996; 45:386-9. [PMID: 8793231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Patients with chronic renal failure appear at greater risk for skeletal muscle side effects from the fibric acid group of lipid lowering agents. In order to determine whether sub-clinical defects of skeletal muscle metabolism can be detected in dyslipidaemic dialysis-dependent patients receiving fibrates. we studied nine patients before and after three months of gemfibrozil therapy (300-600 mg daily). Aerobic and anaerobic metabolism of the right calf muscle was examined at rest and during exercise using 31P magnetic resonance spectroscopy. Near infra-red spectroscopy was used to assess skeletal muscle re-oxygenation following ischaemic exercise of the arm. Following gemfibrozil treatment plasma triglycerides fell significantly 3.0 +/- 0.5 mM (SEM) to 1.5 +/- 0.2 mM. Gemfibrozil did not affect the established metabolic defects that exist in the skeletal muscle of the dialysed patient. Skeletal muscle re-oxygenation was not significantly lower in renal failure and was not altered by gemfibrozil. Gemfibrozil (600 mg daily) significantly improved the lipid profile of chronic renal failure and was not associated with clinical or bioenergetic impairment of skeletal muscle metabolism.
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Miall-Allen VM, Kemp GJ, Rajagopalan B, Taylor DJ, Radda GK, Haworth SG. Magnetic resonance spectroscopy in congenital heart disease. HEART (BRITISH CARDIAC SOCIETY) 1996; 75:614-9. [PMID: 8697167 PMCID: PMC484387 DOI: 10.1136/hrt.75.6.614] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine the feasibility of studying myocardial and skeletal muscle bioenergetics using 31P magnetic resonance spectroscopy (MRS) in babies and young children with congenital heart disease. SUBJECTS 16 control subjects aged 5 months to 24 years and 18 patients with CHD, aged 7 months to 23 years, of whom 11 had cyanotic CHD, five had cardiac failure, and two had had a Senning procedure. DESIGN 31P MRS was carried out using a 1.9 Tesla horizontal 65 cm bore whole body magnet to study the myocardium in 10 patients and skeletal muscle (gastrocnemius) in 14 patients, eight of whom were exercised, together with appropriate controls. RESULTS In hypoxaemic patients, in skeletal muscle at rest intracellular pH (pHi) was abnormally high [7.06 (SEM 0.04) v 7.04 (0.05), P < 0.01] and showed a positive correlation with haemoglobin (P < 0.03). On exercise, hypoxaemic patients fatigued more quickly but end-exercise pHi and phosphocreatine recovery were normal, implying that an equivalent but smaller amount of work had been performed. End-exercise ADP concentration was lower. On recovery, the initial rate of phosphocreatine resynthesis was low. Skeletal muscle bioenergetics were within normal limits in those in heart failure. In the myocardium, the phosphocreatine/ATP ratio was similar in controls and hypoxaemic subjects, but low in those in heart failure. CONCLUSIONS In heart failure, the myocardial phosphocreatine/ATP ratio was reduced, as in adults, while resting skeletal muscle studies were normal. By contrast, hypoxaemic children had normal myocardial bioenergetics, but showed skeletal muscle alkalinity, and energy reserves were more readily depleted on exercise. On recovery, the initially slow phosphocreatine resynthesis rate reflects a low rate of mitochondrial ATP synthesis, probably due to an inadequate oxygen supply. 31P MRS offers a safe, non-invasive method of studying myocardial and skeletal muscle bioenergetics in children as young as 5 months.
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Taylor DJ, Hebert PD, Colbourne JK. Phylogenetics and evolution of the Daphnia longispina group (Crustacea) based on 12S rDNA sequence and allozyme variation. Mol Phylogenet Evol 1996; 5:495-510. [PMID: 8744763 DOI: 10.1006/mpev.1996.0045] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although members of the crustacean genus Daphnia have been the target of much research, there is little understanding of the group's evolutionary history. We addressed this gap by inferring a phylogeny for one of the major species groups (longispina) using nucleotide sequence variation of a 525-bp segment of the mitochondrial 12S rDNA and allozyme variation at 21 loci. We identified the major lineages and their relationships, assessed the phylogenetic utility of the few morphological characters in the group, and examined Daphnia phylogeography. Nuclear and mtDNA phylogenies were generally concordant in recognizing the same four species complexes. An exception was the position of Daphnia galeata mendotae. The allozyme tree paired this species with the Daphnia rosea lineage, whereas the mtDNA trees grouped D. g. mendotae with Daphnia galeata galeata. This discordance was consistent with the reticulate evolution of nuclear genes supporting the hypothesis that D. g. mendotae represents a case of homoploid hybrid speciation. Striking morphological stasis in the longispina group was evidenced by its very limited morphological divergence over an estimated 100 MY, and by the unusual transitional saturation of the conservative 12S rRNA gene within a species group. Phylogenetic inference also provided evidence that similarities in cephalic crest shape likely resulted from convergent or parallel evolution among species. Endemism at the continental level was indicated for previously cosmopolitan species, but the estimated times of these divisions were inconsistent with vicariance events suggesting recent dispersal among continents. A significant role for divergent selection in new habitats during speciation was suggested by the neighboringly sympatric distributions of four sister species pairs over broad geographic areas.
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Cheung NT, Mattey DL, Dawes PT, Taylor DJ. Serum pro-matrix metalloproteinase 3 in rheumatoid arthritis: a reflection of local or systemic inflammation? ARTHRITIS AND RHEUMATISM 1996; 39:884-6. [PMID: 8639190 DOI: 10.1002/art.1780390526] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Stanley B, Teague B, Raptis S, Taylor DJ, Berce M. Efficacy of balloon angioplasty of the superficial femoral artery and popliteal artery in the relief of leg ischemia. J Vasc Surg 1996; 23:679-85. [PMID: 8627905 DOI: 10.1016/s0741-5214(96)80049-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To assess the efficacy of balloon angioplasty in the superficial femoral artery (SFA) and popliteal artery for relief of lower-limb claudication and critical ischemia. METHODS All patients who underwent SFA or popliteal balloon angioplasty at the Royal Adelaide Hospital between January 1989 and September 1994 were reviewed. Risk factors, indications, angiographic variables, and complications were assessed. Outcome was expressed in life-table form as patency, limb survival, and patient survival rates. RESULTS One hundred seventy-six patients (96 men, 80 women) who underwent 200 balloon angioplasty procedures were monitored for a mean of 25 months. Seventy-four percent of procedures were for claudication relief and 26% for critical ischemia. The cumulative patency rate at 24 months for all cases was 46%. The limb salvage rate was 95%, and the patient survival rate was 91% at 24 months. CONCLUSION Percutaneous transluminal angioplasty of the SFA and popliteal arteries is commonly used to treat claudication and critical ischemia but is associated with a high initial failure rate and poor patency at 24 months. Balloon angioplasty is not recommended to treat claudication.
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Halligan A, Shennan A, Lambert PC, de Swiet M, Taylor DJ. Diurnal blood pressure difference in the assessment of preeclampsia. Obstet Gynecol 1996; 87:205-8. [PMID: 8559524 DOI: 10.1016/0029-7844(95)00379-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To evaluate diurnal variation in blood pressure (BP) in normal gravidas and those with preeclampsia, using ambulatory BP monitoring. METHODS A cross-sectional comparative observational study was performed in three teaching hospital maternity units. Twenty-four normotensive and 24 preeclamptic women who were similar in age, weight, and mean duration of gestation (35 weeks) were studied. Diurnal variation and BP measurement were assessed using ambulatory BP monitors validated for use in pregnancy and for which normal reference ranges for pregnancy have been derived. RESULTS At night, the BP fall was less in preeclamptic women than in normotensive women. The day-night BP difference decreased as average BP rose (diastolic gradient = -0.54 [95% confidence interval (CI) -0.77 to -0.31], systolic gradient = -0.36 [95% CI -0.58 to -0.14], where gradient denotes a unit increase in BP leading to an increase or decrease in the day-night difference). CONCLUSION The decrease in day-night BP difference observed in preeclampsia is inversely related to average BP. This blunting of the day-night BP difference may be a useful adjunctive measure of disease severity in preeclampsia.
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Shennan A, Gupta M, Halligan A, Taylor DJ, de Swiet M. Lack of reproducibility in pregnancy of Korotkoff phase IV as measured by mercury sphygmomanometry. Lancet 1996; 347:139-42. [PMID: 8544546 DOI: 10.1016/s0140-6736(96)90338-4] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Since hypertensive disorders of pregnancy are common, blood pressure is frequently measured in all pregnant women. Many authorities recommend that Korotkoff phase IV (K4, muffling of sound) is taken as the diastolic identification point measured on mercury sphygmomanometry in pregnancy because of reports that phase V (K5, disappearance of sound) is at or near to zero cuff pressure in some pregnant women. We compared the identification and reproducibility of K4 and K5 by observers unaware of each other's results. METHODS In the first part of the study, two pairs of observers each took 340 measurements in 85 pregnant women. The second part of the study consisted of 1120 measurements in 80 pregnant and 80 non-pregnant women by five pairs of observers. Measurements were taken simultaneously by sphygmomanometry with a shared cuff and diaphragm; the observers were in separate booths. FINDINGS K5 was identified in all measurements by both observers and never approached zero. K4 was heard in only 52% of measurements; in 33% of cases it was heard by only one of the pair of observers, so the pair agreed on its detection in only 19% of readings. Visual analogue scores used to assess Korotkoff sound quality indicated that systolic blood pressure was perceived significantly more clearly than diastolic blood pressure (K4 or K5). Even when K4 was heard by both observers, agreement on its value was poor (78% within 5 mm Hg vs 86% for K5, p < 0.05). K4 was heard significantly less often in non-pregnant women (32% of measurements). There was also no consistency in the identification of K4 within individual women. INTERPRETATION K4 has little value in clinical management because it cannot be reproduced accurately. We recommend that K4 should be replaced by K5 as the measure of diastolic blood pressure in pregnancy.
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Kemp GJ, Hands LJ, Ramaswami G, Taylor DJ, Nicolaides A, Amato A, Radda GK. Calf muscle mitochondrial and glycogenolytic ATP synthesis in patients with claudication due to peripheral vascular disease analysed using 31P magnetic resonance spectroscopy. Clin Sci (Lond) 1995; 89:581-90. [PMID: 8549076 DOI: 10.1042/cs0890581] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. We set out to define abnormalities of oxidative ATP synthesis, cellular proton efflux and the efficiency of ATP usage in gastrocnemius muscle of patients with claudication due to peripheral vascular disease, using data obtained by 31P magnetic resonance spectroscopy during aerobic exercise and recovery. 2. Eleven patients with moderate claudication were studied and results were compared with 25 age-matched control subjects. Changes in pH and phosphocreatine concentration during recovery were used to calculate the maximum rate of oxidative ATP synthesis (Qmax.) and the capacity of net proton efflux. Changes in pH and phosphocreatine concentration were used to estimate rates of non-oxidative and (indirectly) oxidative ATP synthesis throughout exercise, taking account of abnormalities in proton efflux during exercise. 3. In patients with claudication, slow post-exercise phosphocreatine recovery showed a 42 +/- 9% decrease in Qmax., and the slow ADP recovery was consistent with this. pH recovery was slow, showing a 77 +/- 9% decrease in the capacity for proton efflux. Both abnormalities are compatible with a substantial reduction in muscle blood flow. 4. During exercise, increased phosphocreatine depletion and intracellular acidification were a consequence of impaired oxidative ATP synthesis and the consequent increase in non-oxidative ATP synthesis, compounded by reduced proton efflux. The acidification prevented an increase in ADP concentration which could otherwise partially compensate for the oxidative defect. All these abnormalities are compatible with a reduced muscle blood flow. 5. In addition, initial-exercise changes in pH and phosphocreatine concentration implied a 44 +/- 5% reduction in 'effective muscle mass', necessitating an ATP turnover (per litre of muscle water) twice as high for given power output as in control muscle. Some of this is probably due to a localized loss of muscle fibres, but the rest appears to reflect reduced metabolic efficiency of the muscle. This is not a direct consequence of reduced blood flow, and may be related to change in muscle fibre type.
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Cheung NT, Taylor DJ, Dawes PT. Elevated plasma stromelysin levels in arthritis. J Rheumatol 1995; 22:2004-2005. [PMID: 8992009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Taylor DJ, Thompson CH, Kemp GJ, Barnes PR, Sanderson AL, Radda GK, Phillips DI. A relationship between impaired fetal growth and reduced muscle glycolysis revealed by 31P magnetic resonance spectroscopy. Diabetologia 1995; 38:1205-12. [PMID: 8690173 DOI: 10.1007/bf00422370] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Thinness at birth is associated with insulin resistance and an increased prevalence of non-insulin-dependent diabetes mellitus in adult life. As muscle is an important site of insulin resistance, and because thin babies have reduced muscle mass, thinness at birth may affect muscle structure and function and impair carbohydrate metabolism. We have therefore used 31P magnetic resonance spectroscopy to investigate the bioenergetics of gastrocnemius and flexor digitorum superficialis muscles in 16 normoglycaemic women who had a low ( < or = 23 kg/m3) and 9 women who had a high (> 23 kg/m3) ponderal index at birth. In the flexor digitorum superficialis study anaerobic metabolism was stressed with a constant heavy workload. Low ponderal index subjects fatigued more rapidly (3.3 vs 5.8 min); as phosphocreatine decreased, the accompanying drop in muscle pH was less than in the high ponderal index group. In the first minute of exercise phosphocreatine fell and adenosine diphosphate rose more rapidly (p=0.04 and 0.03, respectively). Gastrocnemius showed a similar trend late in exercise (this exercise was more oxidative, becoming more anaerobic with increasing workload). These changes were not explained by differences in body composition, muscle mass or blood flow. The findings are consistent with a decreased lactic acid and glycolytic adenosine triphosphate production in the low ponderal index group and suggest the possibility that the mechanisms which control substrate utilisation and metabolism in adult life be programmed during prenatal life.
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Kemp GJ, Taylor DJ, Barnes PR, Wilson J, Radda GK. Skeletal muscle mitochondrial dysfunction in alternating hemiplegia of childhood. Ann Neurol 1995; 38:681-4. [PMID: 7574469 DOI: 10.1002/ana.410380421] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Alternating hemiplegia of childhood is an uncommon disease characterized by repeated, transient attacks of hemiplegia. Its pathophysiology is uncertain, but attention recently has focused on possible mitochondrial abnormalities. Using 31P magnetic resonance spectroscopy, we studied gastrocnemius muscle in 5 patients with alternating hemiplegia, aged 8 to 30 (mean, 18) years, at rest and during incremental aerobic exercise and recovery. There were no significant differences in resting muscle between patients and a control group aged 7 to 42 (mean, 19) years. Exercise performance was grossly impaired in the patients, the mean duration being 30% of normal. The total change in pH during exercise was somewhat less than in control subjects, while the changes in phosphocreatine concentration and intracellular ADP were similar. Thus the average overall rate of fall of phosphocreatine concentration during exercise was three-fold greater than in control subjects. However, the initial rate of ATP turnover at the start of exercise (a measure of muscle mass and efficiency) was not abnormal. During recovery, both the initial rate of phosphocreatine resynthesis and the calculated mitochondrial capacity were reduced by about 35%. This mitochondrial defect probably explains most of the abnormalities seen during exercise.
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Konje JC, de Chazal R, MacFadyen U, Taylor DJ. Antenatal diagnosis and management of meconium peritonitis: a case report and review of the literature. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 1995; 6:66-69. [PMID: 8528807 DOI: 10.1046/j.1469-0705.1995.06010066.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We present a case of meconium peritonitis which was associated with a short bowel and complicated by progressive bowel distension and difficulty in making a definitive diagnosis of cystic fibrosis. Treatment was by bowel resection and an ileostomy (and later bowel anastomosis), followed by parenteral nutrition which was complicated by hepatitis. The literature is reviewed and management dilemmas and options are discussed.
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Radda GK, Odoom J, Kemp G, Taylor DJ, Thompson C, Styles P. Assessment of mitochondrial function and control in normal and diseased states. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1271:15-9. [PMID: 7599201 DOI: 10.1016/0925-4439(95)00004-n] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mitochondrial function in muscle in vivo can be quantitatively evaluated using 31-phosphorus nuclear magnetic resonance. In resting muscle, the concentrations of ions (e.g. H+, Na+) and two of the major bioenergetic components (inorganic phosphate and creatine) are determined by regulated transcellular transport processes. During recovery after exercise the kinetics and control of mitochondrial ATP synthesis can be established. During exercise the relative contributions to ATP synthesis of phosphocreatine (using creatine kinase), anaerobic glycogenolysis and oxidative phosphorylation are dissected and have been shown to change with time. The consequences of mitochondrial lesions and dysfunctions on these processes have been summarised.
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Kemp GJ, Thompson CH, Taylor DJ, Radda GK. ATP production and mechanical work in exercising skeletal muscle: a theoretical analysis applied to 31P magnetic resonance spectroscopic studies of dialyzed uremic patients. Magn Reson Med 1995; 33:601-9. [PMID: 7596263 DOI: 10.1002/mrm.1910330504] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
31P magnetic resonance spectroscopy (31P MRS) can yield much information about bioenergetics in skeletal muscle. During mixed aerobic/glycolytic exercise, changes in phosphocreatine (PCr) concentration and pH may be abnormal because of reduced muscle mass or reduced efficiency (which the authors combine here as "effective muscle mass") or because of reduced oxidative capacity. The authors show how these can be distinguished by calculating the nonoxidative and oxidative costs of mechanical work, and also of work per unit of effective muscle mass (measured using the initial rate of ATP turnover). These quantities are substantially time-independent during incremental exercise, and so can be used to compare exercise studies of differing duration. The authors illustrate this analysis by showing that in dialyzed patients with chronic renal failure, the substantial exercise abnormalities seen by 31P MRS are due mainly to a decrease in effective muscle mass, which outweighs the oxidative defect implied by the abnormal PCr recovery kinetics.
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Willms R, Taylor DJ, Enoeda M, Okuno K. Practical-scale tests of cryogenic molecular sieve for separating low-concentration hydrogen isotopes from helium. FUSION ENGINEERING AND DESIGN 1995. [DOI: 10.1016/0920-3796(95)90065-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sherman RH, Taylor DJ, Yamanishi T, Enoeda M, Konishi S, Okuno K. The role of sidestream recycle in hydrogen isotope separation and column cascade design. FUSION ENGINEERING AND DESIGN 1995. [DOI: 10.1016/0920-3796(95)90066-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
31Phosphorus nuclear magnetic resonance spectroscopy was used to examine skeletal muscle in 29 patients with mitochondrial myopathy, 9 male and 20 female. Gastrocnemius was investigated in 15 patients and 30 normal subjects and finger flexor muscle (flexor digitorum superficialis, fds) in 24 patients and 35 normal controls. Both muscles were studied in 10 of the patients. Results were abnormal (outside the full range of normal values) in all but 2 patients. In 86% of patients (25/29) abnormalities were detected in resting muscle. In most cases there was a low phosphocreatine/ATP ratio, high calculated free [ADP] and low phosphorylation potential. At rest, abnormality was detected with equal ease in fds and gastrocnemius. Exercise and recovery increased the sensitivity of MRS in detecting abnormal metabolism. Finger flexion was better tolerated by patients than plantar flexion and gave bigger changes in metabolite concentrations and intracellular pH. Thus, results from fds were more easily differentiated from normal. Exercise duration was significantly shorter than in controls while phosphocreatine depletion was more rapid than normal, consistent with a shortfall in mitochondrial ATP synthesis. Nearly all patients (25/27, 93%) showed abnormalities during recovery from exercise. [ADP] was high during exercise and its recovery was delayed, providing increased drive for oxidative phosphorylation. Phosphocreatine resynthesis during recovery (which reflects oxidative ATP synthesis) was slow both in absolute terms and in relation to [ADP]. Recovery of intracellular pH after exercise was significantly more rapid than normal, consistent with an upregulation of proton efflux.(ABSTRACT TRUNCATED AT 250 WORDS)
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