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Biomedical subjects

J Anthony

Publications and source records attributed to J Anthony.

At least 19 recordsLinked to original sources

Cardiovascular responses to the change from the left lateral to the upright position in pregnant hypertensives.

OBJECTIVES: To evaluate by non-invasive means, the autonomically mediated changes in heart rate and blood pressure in response to postural change in pregnancy. METHODS: Ninety-one patients were studied, of whom 17 were non-pregnant controls, 21 were normotensive parturients, 22 had non-proteinuric hypertension, and 31 were pre-eclamptics. In all patients the heart rate and blood pressure response to the change from the left lateral to the erect position was measured non-invasively, during the third trimester in the pregnant groups. RESULTS: The change from the left lateral to the erect position induced significantly greater mean changes (increases) in systolic blood pressure in the normotensive pregnant (PC) women than all other groups (P<0.05). Pre-eclamptic patients (PE) exhibited significantly less of an increase in systolic blood pressure than the non-proteinuric hypertensive (H) group. Both the H and PC groups showed significantly greater increases in diastolic pressure than the non-pregnant (NP) group. PE patients had a significantly smaller increase in diastolic pressure than the H group. There were no significant differences between heart rate changes when comparing the PC, NP and H groups. The PE group exhibited a significantly greater increase in heart rate on adopting the erect position than all other groups. CONCLUSIONS: Pre-eclamptics exhibit smaller changes in blood pressure than normotensive pregnant patients and non-proteinuric hypertensives on standing, while producing an exaggerated heart rate response, indicating altered autonomic compensatory mechanisms in these patients.

Adult↗

A double-blind randomised controlled trial of continuous oxygen therapy for compromised fetuses.

OBJECTIVE: To investigate the effect of chronic oxygen therapy in fetuses with absent end diastolic flow in the umbilical artery assessed by doppler analysis at 24-30 weeks of gestation. DESIGN: A double-blind, randomised control trial was performed with patients blindly allocated to receive humidified oxygen or humidified air. SETTING: A tertiary referral hospital in South Africa. PARTICIPANTS: Thirty-two women who presented between 24 and 30 weeks of gestation with a confirmed finding of absent end diastolic flow in the umbilical artery. METHODS: After randomisation patients were allocated to receive a 40% mixture of humidified oxygen or humidified air from uniform coloured gas cylinders which were marked either 'a' or 'b' All women received betamethasone from 27 weeks of gestation on a weekly basis. Cardiotocographs were used from 28 weeks of gestation; after 28 weeks of gestation an amniocentesis was considered to confirm fetal maturity. Women were expected to breath the allocated gas continuously apart from meals and visits to the toilet. MAIN OUTCOME MEASURES: Survival of the fetus was the main outcome measure with secondary outcome measures documenting improvement in the fetal condition in utero. RESULTS: There were 16 women randomised to receive oxygen and 16 to receive air. There were nine survivors in the oxygen group (56.3%) and six in the air group (37.5%) (relative risk 1.5, 95% confidence interval 0.7-3.2). There was a nonsignificant increase in mean birthweight in the oxygen group (858.3 grammes vs 774.4 grammes) and a nonsignificant increase in mean duration of treatment in the oxygen group (12.8 days vs 10.4 days). CONCLUSION: This study did not demonstrate that chronic oxygen therapy provides any benefits to compromised fetuses between 24 and 30 weeks of gestation. Larger studies with sufficient power are necessary to assess whether oxygen therapy can reduce perinatal mortality by a clinically useful amount in this group of patients.

Cardiotocography↗

The immunoglobulin G heavy chain repertoire in multiple sclerosis plaques is distinct from the heavy chain repertoire in peripheral blood lymphocytes.

Analyses have shown that the repertoire of Ig heavy chain sequences (VH) expressed in multiple sclerosis (MS) plaques or cerebrospinal fluid is consistent with B cell clonal expansion and affinity maturation. PCR amplification of VH sequences from MS lesions obtained from an acute MS patient at autopsy revealed oligoclonal and extensively mutated VH sequences from plaque-periplaque regions with discrete intraclonal differences indicative of B cell clonal expansion in the groups of overrepresented major sequences. None of the VH sequences expressed in plaque regions were detected in peripheral blood lymphocytes from this patient. These data indicate the presence of a CNS-targeted antigen-driven response in MS plaques.

Amino Acid Sequence↗

Oral misoprostol vs. placebo in the management of prelabor rupture of membranes at term.

OBJECTIVE: To evaluate the efficacy of oral misoprostol for the induction of labor (IOL) in women with prelabor rupture of membranes at term (PROM) and to monitor maternal or fetal complications. METHOD: This randomized, placebo controlled trial was performed in a secondary referral hospital. The data of 47 patients in the misoprostol--and 49 patients in the placebo group was available for analysis. The former received 100 microg misoprostol orally, repeated once after 6 h if not in active labor, the latter received two doses of vitamin C also after a 6-h interval. The Mann-Whitney U-test was used for analysis. RESULTS: The median treatment to delivery interval in the misoprostol group was 7.5 h and 25 h in the placebo group (P<0.001). No significant differences were found in the incidence of abnormalities on the cardiotocograph, mode of delivery, neonatal outcome, use of antibiotics for the mothers and patient acceptability. CONCLUSION: Oral misoprostol in the suggested dose is an effective and cheap alternative for IOL in patients with PROM. No adverse effects could be demonstrated.

Administration, Oral↗

Cardiovascular responses to repetitive McKenzie lumbar spine exercises.

BACKGROUND AND PURPOSE: Repetitive exercises of the type recommended by McKenzie for the lumbar spine, such as flexion and extension exercises in standing (FIS and EIS) and lying positions (FIL and EIL), have been used in the management of low back pain for over 20 years. The cardiovascular effects of exercises that involve postural stabilization and the arms and of exercises performed in a lying position are well known. Therefore, the purpose of this study was to examine the cardiovascular effects of 4 exercises used in the McKenzie system. SUBJECTS AND METHODS: One hundred subjects without cardiovascular or cardiopulmonary disease (mean age=31 years, SD=6.1, range=22-44) and who were representative of people susceptible to low back pain were studied. Subjects were randomly assigned to 1 of 4 exercise groups (ie, FIS, EIS, FIL, and EIL). Subjects performed sets of 10, 15, and 20 repetitions of the assigned exercise, with a 15-minute rest between sets. Heart rate, blood pressure, and rate-pressure product (an index of myocardial work) were recorded before and after each set of repetitions. RESULTS: After 10 repetitions, flexion and extension in lying were more hemodynamically demanding than in standing. This trend persisted for 15 and 20 repetitions; however, at 20 repetitions, the hemodynamic demands were different across exercise groups (ie, FIL>EIL>FIS>EIS). DISCUSSION AND CONCLUSION: Repetitive exercises of the type suggested by McKenzie for the lumbar spine can have cardiovascular effects in people with no cardiovascular or cardiopulmonary conditions. These effects may be important with respect to cardiac work, and patients for whom these exercises are indicated should have a cardiac and pulmonary risk factor assessment to determine whether heart rate and blood pressure should be monitored.

Adult↗

Changes in 5-HT(7) serotonin receptor mRNA expression with aging in rat brain.

We examined 5-HT(7) receptor mRNA expression with in situ hybridization histochemistry in the brains of young (3 months), middle-aged (12 months) and old rats (24 months). In the ventral CA3 area of the hippocampus 5-HT(7) mRNA expression is reduced by approximately 30% between young and middle age without further decline between middle and old age. In other brain areas 5-HT(7) mRNA expression is unaffected by age.

Aging↗

Comparison of immunoglobulin G heavy-chain sequences in MS and SSPE brains reveals an antigen-driven response.

OBJECTIVE: To better understand B-cell activation in MS by analyzing the immunoglobulin (Ig)G heavy chain variable region (VH) repertoire found in MS brains and comparing it with brain VH sequences in individuals with subacute sclerosing panencephalitis (SSPE)--a chronic encephalitis produced by measles virus (MV)-and characterized by an antigen-driven oligoclonal IgG response to MV antigens. BACKGROUND: The specificity of oligoclonal IgG in MS CSF and plaques, and their relevance to the pathogenesis of MS is unknown. METHODS: Nested PCR was used to amplify and sequence the rearranged IgG heavy-chain VH repertoire in plaques of three acute MS brains and in three SSPE brains. A representative population of VH sequences from each tissue was aligned to the known 51 functional VH germline segments. From this the authors determined the closest VH family germline segment, and the degree and location of somatic mutations for each unique IgG. RESULTS: As expected for an antigen-driven response against MV antigens, most VH sequences from the SSPE brains were mutated extensively compared with their closest germline segments. Furthermore, SSPE VH sequences accumulated replacement mutations preferentially in the complementary-determining regions (CDRs) relative to framework regions-features normally observed during antigen-driven selection. A comparison of VH family and germline usage also demonstrated that each SSPE brain had its own unique IgG response. When the authors compared the VH response in MS plaques with SSPE, MS VH sequences were also mutated extensively, displayed a preferential accumulation of replacement mutations in CDRs, and were unique in each MS brain. CONCLUSION: The presence of an antigen-driven response in MS, rather than a nonconventional mechanism of B-cell activation, warrants additional analysis of the specificity of IgG in MS brain and CSF.

Adolescent↗

White matter hyperintensity volume in late-onset and early-onset schizophrenia.

BACKGROUND: Late life onset schizophrenia (sometimes termed "late paraphrenia") has been theorized to be due to neuro-degenerative processes affecting individuals with latent vulnerability to schizophrenia. However, neuro-imaging studies using computed tomography (CT) and magnetic resonance imaging (MRI) investigating possible degenerative anatomic correlates (atrophy, white matter disease, and strokes) to late onset psychoses have yielded conflicting findings. The variation in these findings may be due to differences in study design, case ascertainment, and measurement methods. OBJECTIVE: The present study compares a continuous measure of total volume of white matter hyperintensities (WMHs) in age, race, and gender-ratio matched groups of late-onset schizophrenic, elderly, early-onset schizophrenic and control subjects. METHOD: Our method of WMH measurement yielded an explicit volume and is an alternative to frequently used ordinal measures. RESULTS: We found no significant differences in the WMH volumes between these three groups. This finding is consistent with a prior study (Symonds et al., 1997. J Neuropsychiat Clin Neurosci 9: 251 - 258), that used ordinal measures.

Age of Onset↗

The safety and utility of pulmonary artery catheterization in severe preeclampsia and eclampsia.

OBJECTIVE: The objective of this research was to study the safety and utility of pulmonary artery catheterization in the management of severe preeclampsia and eclampsia. STUDY DESIGN: In a retrospective chart review from January 1, 1995, through December 31, 1997, a total of 115 patients admitted to the obstetric intensive care unit at Groote Schuur Hospital were found to have required placement of a pulmonary artery catheter. From this population 100 maternal charts were examined for medical and pregnancy history, including indication for pulmonary artery catheter placement, hemodynamic readings, complications, and subsequent management. RESULTS: The initial indications for pulmonary artery catheter placement in cases of severe preeclampsia or eclampsia were renal failure in 53 cases (53%), pulmonary edema in 30 (30%), and eclampsia in 17 (17%). Subjective evaluation demonstrated that the pulmonary artery catheter was helpful in determining management in 93 cases (93%). There was a 4.0% complication rate, which included three venous thromboses and one case of cellulitis. Eleven patients required dialysis, and 3 women died. The mean (+/-SE) duration of catheter placement was 2.1 +/- 0.1 days and the mean (+/-SE) intensive care unit and hospital stays were 3.4 +/- 0.2 days and 11.4 +/- 0.8 days, respectively. The pulmonary artery catheter measurements of pulmonary artery wedge pressure and central venous pressure were increased in the cases of pulmonary edema (21.0 +/- 2.0 mm Hg and 9. 6 +/- 1.2 mm Hg, respectively) but were normal in the cases of renal failure and eclampsia. CONCLUSION: Despite significant maternal morbidity and mortality, pulmonary artery catheter use in cases of severe preeclampsia or eclampsia was subjectively beneficial in 93 of 100 cases (93%), with an acceptable complication rate (4.0%).

Acute Kidney Injury↗

A comparison of hemodynamic data derived by pulmonary artery flotation catheter and the esophageal Doppler monitor in preeclampsia.

OBJECTIVE: This study was undertaken to compare hemodynamic data derived with the esophageal Doppler monitor against those obtained with a pulmonary artery flotation catheter in women with complicated preeclampsia. STUDY DESIGN: Seventeen women with severe preeclampsia who had a pulmonary artery flotation catheter placed for clinical indications also had an esophageal Doppler monitor inserted. Hemodynamic data were recorded on 2 occasions separated by several hours with both the pulmonary artery flotation catheter and the esophageal Doppler monitor simultaneously. RESULTS: The esophageal Doppler monitor underestimated cardiac output by 36% +/- 14% (mean +/- SD). The esophageal Doppler monitor accurately estimated cardiac output in 3 women >40 years old, whereas in the remaining women (all <35 years old) the esophageal Doppler monitor underestimated cardiac output by 38% +/- 11%. The esophageal Doppler monitor accurately reflected changes in cardiac output with time when compared with the pulmonary artery flotation catheter. CONCLUSION: In women with preeclampsia the esophageal Doppler monitor consistently underestimated cardiac output by approximately 40%. It is not known whether the apparent increase in accuracy among the women >40 years old arose by chance or reflected a real improvement in performance. The esophageal Doppler monitor accurately reflected the direction and magnitude of the changes in cardiac output with time.

Adult↗

Fluid management in severe preeclampsia (VESPA): survey of members of ISSHP.

OBJECTIVE: To determine international expert practice of fluid management and monitoring in severe preeclampsia. METHODS: The 447 members of the ISSHP (International Society for the Study of Hypertension in Pregnancy) were issued a postal questionnaire to determine their views and practices of fluid management in severe preeclampsia. RESULTS: One hundred sixty-six (37%) completed questionnaires were received. Responses indicated that there is no consensus regarding most aspects of management of severe preeclamptic patients. In particular, there is no agreement about which fluid type to administer and how to assess circulatory status in these patients. There were also wide variations in the use of plasma volume expansion as a treatment modality. Statistical comparison of the use of Swan-Ganz catheters in "theoretical" and "actual" practice showed highly significant differences (p < 0.001). The majority of respondents were interested in participating in future research. CONCLUSION: The results reflect genuine uncertainty generated by a lack of evidence from randomized trials addressing the acute management of severe preeclamptic patients. Even where clinicians are confident "in theory" that a particular form of treatment is the best, they do not appear to have the resources or commitment to match this with "practice." The majority of respondents were very keen to develop the questions raised further in the context of multicenter clinical trials.

Acute Disease↗

Retraining of a competitive master athlete following traumatic injury: a case study.

PURPOSE: The purpose of this study was to examine the physiological effects of detraining and retraining in a female master cyclist (age, 49.5 yr; wt, 54 kg) following a surgically-treated clavicular fracture complicated by brachial plexus impingement. METHODS: Variables associated with cycling performance, including VO2max, lactate threshold (LT), power output at a blood lactate concentration of 4 mM (LT(4 mM)), peak power output (PPO), muscular resistance to fatigue measured by a timed ride to exhaustion at 110% of peak power output (PPO110), and body composition (hydrostatic weight) were assessed 2 d before the injury when the subject was at the peak of her competitive season, and at days 0, 14, 28, 42, and 77 of the retraining period. Retraining gradually increased from 3 h x wk(-1) to 9-10 h x wk(-1) with an increase in intensity from approximately 70 to 95+% of HRmax. RESULTS: Detraining resulted in a 25.7% decrease in VO2max and a 16.7% and 18.9% decrease in LT and LT(4 mM), respectively, while peak power output and PPO110 declined 18.2% and 16.6%, respectively. Body fat percent increased 2.1 percentage points, while fat-free mass decreased nearly 2 kg. After 2 wk of retraining, all variables except the LT and LT(4 mM) had improved considerably; however, VO2max was still 14.8% lower and PPO and PPO110 were 12.7% and 5.7% lower than preinjury values. By the 11th week of retraining, all variables had essentially returned to their preinjury values. CONCLUSION: These data demonstrate a pattern of retraining in which aerobic power steadily improved over 6 wk, while measures of lactate threshold did not change until the fourth week of retraining when the intensity of training was markedly increased. Additional data are needed to determine whether this pattern of retraining would be consistent in other master athletes.

Bicycling↗

Comparison of auscultatory and oscillometric automated blood pressure monitors in the setting of preeclampsia.

OBJECTIVE: The aim of this study was to compare the accuracy of 2 automated blood pressure monitors against mercury sphygmomanometry and intra-arterial blood pressure determination in women with preeclampsia. STUDY DESIGN: The auscultatory and oscillometric monitors were compared with mercury sphygmomanometry according to the British Hypertension Society protocol and criteria of the Association for the Advancement of Medical Instrumentation in a group of 30 women with proteinuric preeclampsia. In addition both monitors were compared with intra-arterial blood pressure measurements in a group of 6 women with severe preeclampsia. The mean (+/- SD) of the differences was calculated and a paired t test was used to compare values obtained with each monitor with intra-arterial measurements. RESULTS: Compared with mercury sphygmomanometry the auscultatory QuietTrak monitor markedly underestimated systolic and diastolic blood pressure by 13 +/- 15 mm Hg. The oscillometric SpaceLabs 90207 monitor also underestimated systolic pressure by 10 +/- 10 mm Hg and diastolic pressure by 8 +/- 7 mm Hg. According to the British Hypertension Society grading criteria both monitors achieved the lowest grade (D) for recording systolic and diastolic pressure. The 2 monitors also did not meet the accuracy criteria stipulated by the Association for the Advancement of Medical Instrumentation. Compared with intra-arterial readings the SpaceLabs monitor significantly underestimated systolic and mean arterial pressures (by 19 and 7 mm Hg, respectively, P <. 01). The QuietTrak monitor significantly underestimated systolic, diastolic, and mean arterial pressures (by 25 mm Hg, P <.05, 18 mm Hg, P <.01, and 20 mm Hg, P <.01, respectively). CONCLUSION: Neither monitor can be recommended for clinical use in women with proteinuric preeclampsia.

Auscultation↗

Prevention of eclampsia.

Eclampsia continues to be a major cause of maternal morbidity and mortality rates, especially in underdeveloped nations. Our data indicate that eclampsia may represent the end stage of at least two very different pathophysiological pathways: one in which cerebral perfusion is low because of vasospasm and another in which cerebral perfusion is increased because of abnormal autoregulation and a failure of the normal protective mechanisms. Magnesium sulfate has been extensively used in the management and prevention of eclamptic seizures in the United States and has been recently shown to be superior to both diphenylhydantoin and diazepam. We have shown that magnesium sulfate is a potent vasorelaxant and that its action may depend on improving cerebral perfusion. Nimodipine, a calcium channel blocker with selective cerebrovascular effect, is currently under investigation in severe preeclampsia. The data show that it is as effective as magnesium sulfate in preventing eclampsia, with less maternal and fetal side effects. Magnesium sulfate and nimodipine have opposite effects on the estimated cerebral perfusion pressure as determined with the Doppler ultrasound. We speculate that the estimated cerebral perfusion pressure may be used to determine the type of cerebrovascular abnormality and the most appropriate treatment in each individual patient with preeclampsia.

Antihypertensive Agents↗