Biomedical subjects
P Owens
Publications and source records attributed to P Owens.
Use and interpretation of ambulatory blood pressure monitoring: recommendations of the British hypertension society.
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Comparison of antihypertensive and metabolic effects of losartan and losartan in combination with hydrochlorothiazide--a randomized controlled trial.
INTRODUCTION: Losartan is an angiotensin II receptor blocker indicated for treatment of hypertension. It also inhibits platelet agreggation through blockade of thromboxane A2/ prostaglandin H2 receptors, and has a uricosuric effect We determined the effect on ambulatory blood pressure (ABP) of 100 mg losartan monotherapy (L100) versus 50 mg losartan/12.5 mg hydrochlorothiazide (HCTZ) combination therapy (L50H12.5C), in patients uncontrolled on 50 mg losartan. We also assessed the effects of losartan on platelet aggregation and serum urate at these clinically relevant doses. METHODS: This was a randomized, double-blind trial of L100 versus L50H12.5C, in moderate hypertensives (sitting diastolic blood pressure (DBP) >or = 95 mmHg and < 120 mmHg). After 4 weeks of placebo run-in, patients received 50 mg losartan for 6 weeks; patients uncontrolled (sitting DBP > or = 95 mmHg) were randomized to L100 or L50H12.5C for a further 6 weeks. Platelet function was assessed by measuring percentage inhibition of platelet aggregation, and serum uric acid was also measured. RESULTS: Monotherapy with 50 mg losartan reduced ABP by 16.0/9.9 mmHg during the day and 9.8/5.5 mmHg at night However, 16 out of 24 (66%) patients had uncontrolled blood pressure on this treatment L50H12.5C further reduced daytime ABP by 10.7(10.7)/8.4(6.5) mmHg mean (SEM) compared with L100 (-5.3(9.7)/-2.3(4.8), P = 0.013). 50 mg losartan and L100 did not affect platelet function or uric acid levels beyond placebo values; treatment with L50H12.5C was associated with a significant rise in serum urate above levels obtained on 50 mg losartan (366.9(67.6) versus 331.6(65.0), P=0.006), to levels similar to placebo (358.8(80.9)). CONCLUSION: L50H12.5C is an effective antihypertensive regimen in patients with moderate hypertension that is uncontrolled on 50 mg losartan monotherapy, and is the preferred treatment option in these patients compared with increasing the dose of losartan. The additional benefit of losartan on platelet inhibition was not evident in our population at these doses; however, there was evidence to suggest that the uricosuric effects of losartan might ameliorate the uric acid retention effects of therapy with hydrochlorothiazide.
Specialized assessments for children in foster care.
OBJECTIVE: To investigate the differences in health problems identified and health services received by children newly entering foster care who participated in a comprehensive multidisciplinary program, compared with children newly entering foster care who received customary community-based services. METHODS: Using a 2-group quasiexperimental design, 120 young children entering foster care were enrolled in a multidisciplinary intervention program (n = 62) or were followed by customary care providers (n = 58). An interview with the foster parent; a complete medical examination; and a battery of developmental, psychological, speech/language, and motor assessments were completed for each child at baseline. Children in both groups participated in follow-up assessments at 6 and 12 months. RESULTS: No significant differences between the 2 groups existed in medical, educational, developmental, or mental health problems identified by foster mothers. However, children in the intervention group were more likely to be identified with developmental (56.5% vs 8.6%) and mental health problems (37.1% vs 13.8%) by providers than children in the comparison group. Children in the intervention group were also more likely to be referred for health services at baseline (71.0% vs 43.1%) and receive follow-up care at 6 and 12 months of age than children in the comparison group. CONCLUSIONS: Findings indicate that community providers identify medical and educational needs but do not recognize developmental and mental health needs of young children newly entering foster care. The discrepancies in the number of recommended services and follow-up care between the 2 groups make a case for the establishment of specialized services for children entering out-of-home care.
Technique for a composite femoral intramedullary plug in cemented hip arthroplasty.
A brief technique to place a cement plug on top of a polyethylene is presented. This technique has helped the authors obtain better cement mantles when they are plugging the canal in total hip replacement.
Hypotension in patients with coronary disease: can profound hypotensive events cause myocardial ischaemic events?
OBJECTIVE: To determine whether anginal episodes might be related to extremes of hypotension in patients with ischaemic heart disease taking drugs to treat angina and heart failure. DESIGN AND SETTING: Observational study of patients with ischaemic heart disease attending an urban tertiary referral cardiology centre. INTERVENTIONS AND OUTCOME MEASURES: A selected patient population was enrolled, having: angina on one or more hypotensive cardiovascular medications; hypotension on clinic or ambulatory measurement; and a resting ECG suitable for ambulatory monitoring. Patients had echocardiography, ambulatory blood pressure monitoring, and Holter monitoring. Hypotension induced ischaemic (HII) events were defined as episodes of ST segment ischaemia occurring at least one minute after an ambulatory blood pressure measurement (systolic/diastolic) below 100/65 mm Hg during the day, or 90/50 mm Hg at night. RESULTS: 25 suitable patients were enrolled, and 107 hypotensive events were documented. 40 ST events occurred in 14 patients, of which a quarter were symptomatic. Fourteen HII events occurred in eight patients, with 13 of the 14 preceded by a fall in diastolic pressure (median diastolic pressure 57.5 mm Hg, interquartile range 11, maximum 72 mm Hg, minimum 45 mm Hg), and six preceded by a fall in systolic pressure (chi(2) = 11.9, p < 0.001). ST events were significantly associated with preceding hypotensive events (chi(2) = 40.2, p < 0.0001). Patients with HII events were more frequently taking multiple hypotensive drug regimens (8/8 v 9/17, chi(2) = 5.54, p = 0.022). CONCLUSIONS: In patients with ischaemic heart disease and hypotension, symptomatic and silent ischaemia occurred in a temporally causal relation with hypotension, particularly for diastolic pressures, suggesting that patients with coronary disease may be susceptible to ischaemic events incurred as a result of low blood pressure caused by excessive hypotensive drug treatment.
Diagnosis of white coat hypertension by ambulatory blood pressure monitoring.
White coat hypertension (WCH) is common in referred hypertensive patients. Ambulatory blood pressure monitoring (ABPM) is not free from the white coat syndrome. We examined the use of the elevation of the first and last measurements of ABPM for diagnosis of WCH in a hypertensive population that had been referred to a hospital-based hypertension unit. Data were obtained on 1350 patients for clinic and ABPM parameters. WCH, as diagnosed by conventional clinic blood pressure (BP) measurement, was compared with a variety of alternative methods determined from ABPM. In all cases, mean daytime pressure was <135 mm Hg/85 mm Hg with an elevation of clinic BP >/=140 mm Hg systolic or 90 mm Hg diastolic. The definitions tested for this elevation were first hour mean pressure, first reading, maximum reading in first hour, last hour mean pressure, last reading, maximum reading in the last hour and maximum reading in first or last hour. Elevation of the maximum pressure in the first hour or last hour above 140 mm Hg systolic or 90 mm Hg diastolic showed a high level of agreement (kappa=0.91) with classical WCH for diagnosis of the white coat syndrome. Termed ambulatory white coat hypertension, patients with this finding were older than classic white coat patients and had higher daytime (127+/-6/78+/-5 mm Hg versus 121+/-5.5/74+/-6 mm Hg, P<0.005 for systolic and diastolic) and nighttime (114+/-11/67+/-8 mm Hg versus 106+/-9/61+/-6 mm Hg, P<0.005 for systolic and diastolic) pressures. They also had a significantly greater Sokolow-Lyon index (leads V(1)+V(5), 21+/-7 mV versus 18+/-6 mV). Elevation of BP above 140 mm Hg systolic or 90 mm Hg diastolic in the first or last hour of monitoring diagnoses patients with a white coat response in whom there is a higher BP profile than in patients with classic white coat response alone. We suggest, therefore, that this is a better measure of the white coat phenomenon.
Ambulatory blood pressure in the hypertensive population: patterns and prevalence of hypertensive subforms.
BACKGROUND: A number of clinically identifiable patterns of blood pressure elevation are apparent using ambulatory measurement Their prevalence and age and sex distribution have not been described. The purpose of this study was to describe the epidemiology of patterns of high blood pressure in a large population. DESIGN: Retrospective database analysis of referral hypertensive population. PATIENTS: Clinic and ambulatory blood pressure measurements were performed in 2092 patients with essential hypertension while they were not taking antihypertensive medication. METHODS: The patients were classified into six groups on the basis of their ambulatory blood pressure monitoring profiles: white-coat hypertensives, borderline hypertensives, isolated systolic hypertensives, isolated diastolic hypertensives, combined systolic and diastolic hypertensives and nocturnal hypertensives. The categories were examined for age and sex differences. RESULTS: All patients were categorized into one of the six groups. The majority (56.2%) were systolodiastolic hypertensives, 12.9% were borderline and 10.8% were white-coat hypertensives. Isolated systolic hypertensives comprised 6.2% of the population, isolated diastolic hypertensives 6.9% and nocturnal hypertensives 7.1%. The isolated systolic hypertensives showed the greatest change with age, with a prevalence of < 5% in patients below 40 years of age, rising to almost 20% in the 70 plus age group. White-coat, isolated diastolic and borderline hypertensives showed the opposite change in prevalence, falling from younger to older age groups. Apart from a greater prevalence of white-coat hypertension in females, the patterns were largely similar between sexes. CONCLUSIONS: Ambulatory blood pressure monitoring allows the blood pressure pattern to be defined in hypertensive patients. The patterns identified here in a referral hypertensive cohort show changes in prevalence with age, and further study is required to determine the prognostic significance of hypertensive sub-forms.
What are the normal levels for ambulatory blood pressure measurement?
With acceptance of ambulatory blood pressure measurement as a useful technique in the management of hypertension, the question of what constitutes the upper limit of normality for 24 h blood pressures has been the subject of a number of reviews [1,2]. In fact, there has been remarkable similarity in a number of large population studies [3-10]. For example, taking the 95th percentile as the upper limit of the distribution of daytime blood pressure in various studies in different countries (Internation Database 141/88 mmHg [3,4], Ireland 138/89 mmHg [5], Belgium 137/88 mmHg [6], Japan 138/83 mmHg [7], Denmark 139/88 mmHg [8] and Italy 134/88 mmHg [9,10] gave variations of less than 7/6 mmHg for systolic and diastolic blood pressures, respectively, the average for all studies being 138/87 mmHg (for review, [6]). A review of the literature carried out independently by the American Society of Hypertension [11] and our group [1,2,6] produced an identical recommendation for the levels of daytime blood pressure that may be regarded as normal and abnormal, namely, that blood pressures above 140/90 mmHg are probably abnormal and that blood pressures below 135/85 mmHg are probably normal. Moreover, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure in its recent communication takes blood pressures of awake subjects below 135/85 mmHg to be normal [12].
The network link. An interview with Patti Owens, R.N.
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Placental control of fetal growth.
The placenta exerts its effects on the growth of the fetus from the beginning of pregnancy via metabolic and endocrine mechanisms. To achieve this, the placenta exchanges a wide array of nutrients, endocrine signals, cytokines and growth factors with the mother and the fetus. These exchanges modulate or programme fetal growth and development. This review concentrates on the function and structure of the placenta in humans and in animals, and the effects of experimental perturbation of placental size and function on fetal growth. The consequences for fetal growth of varying the abundance of peptides or, by deleting genes, insulin-like growth factors or cytokines, are also described. Maternal nutritional and hormonal state from as early as the first few days after fertilization, can influence the growth rate of the placenta and the fetus and also the length of gestation. Influences on placental development and their consequences will clearly have an impact on the placental control of fetal growth. Variations in the maternal environment and consequent perturbation of the metabolic and endocrine environment of the placenta and fetus are implicated as being responsible for the associations between prenatal growth of the placenta and its fetus and the subsequent risk of adult disease. The next challenge will be to determine the dominant influences at each stage of fetal and placental growth.
RCH: one rural hospital's prescription for success.
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Insulin-like growth factors I and II are reduced in plasma from growth retarded children with chronic liver disease.
This study shows that blood from young children (< 3 years) with end stage liver disease, contains less IGF-I, IGF-II and IGFBPs than blood from normally growing children without liver disease, despite the provision of adequate calories. These low levels are likely to contribute to growth failure in children with end stage liver disease.
Laser resource directory.
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Administering, documenting, and tracking blood products and volume expanders.
A quality improvement program designed to facilitate the administration, tracking, and documentation of blood products and volume expanders resulted in improved patient safety, improved efficiency, more accurate documentation, and enhanced resource management. Key to the success of the program were the Transfusion Administration Record, the blood product administration guide, and on-line transfusion history recording.
Mood changes, obstetric experience and alterations in plasma cortisol, beta-endorphin and corticotrophin releasing hormone during pregnancy and the puerperium.
The relationships between mood change, obstetric experience and alterations in plasma cortisol, beta-endorphin (beta-EP) and corticotrophin-releasing hormone (CRH) were examined in a prospective study of 97 primiparous Australian women. Psychological measures were administered between the 28th week of pregnancy and the 3rd postnatal month, including the Profile of Mood States (POMS) and the Montgomery Asberg Depressive Rating Scale (MADRS). Blood samples were collected for cortisol, beta-EP and CRH assay on most of these occasions and during labour. Factor analysis was used to identify key subsets of psychological variables for use in the subsequent analyses. 'Mood disturbance' and 'tiredness' factors peaked at 38 weeks' gestation, while 'difficulty falling asleep' was greatest around the time of birth. Cortisol, beta-EP and CRH concentrations rose significantly as pregnancy advanced and peaked at birth; plasma CRH correlated with plasma cortisol (r = 0.54) and beta-EP (r = 0.32). Women with the highest 'mood disturbance' and MADRS depression scores at 28 weeks' gestation received significantly more pain relief during labour. Those women whose mood deteriorated from 38 weeks' gestation to postnatal day 2 had larger falls in plasma beta-EP after delivery (p less than 0.01) than those women whose mood improved or remained constant. Women in this mood-deteriorated subgroup also had significantly higher MADRS depression scores at 3 months (p less than 0.01). Mild antenatal depression (MADRS greater than 13) occurred in 5.2% of women and mild postnatal depression in 4.7%. Overall, these data suggest a role for circulating CRH in the regulation of maternal cortisol secretion and significant relationships between maternal postnatal mood states and beta-EP and between antenatal mood states and obstetric events.
Secretion of N-terminal pro-opiomelanocortin-derived peptides in response to acute haemorrhagic stress in conscious sheep.
To determine whether peptides derived from the N-terminus of the corticotropin/melanotropin/endorphin precursor, pro-opiomelanocortin, are released into blood in response to acute haemorrhagic stress, we examined the effect of haemorrhage on plasma concentrations of immunoreactive gamma 3-melanotropin, beta-endorphin and cortisol. Plasma concentrations of immunoreactive gamma 3-melanotropin (mean +/- SEM) increased within 30 min of haemorrhage from 71.1 +/- 10.4 to 106.8 +/- 6.3 fmol/mL (p less than 0.01) and plasma cortisol increased from 16.2 +/- 3.8 to 85.9 +/- 22.4 pmol/mL (p less than 0.025). The changes in plasma immunoreactive gamma 3-melanotropin and beta-endorphin were positively correlated (p less than 0.025). This study shows that peptides derived from the N-terminus of pro-opiomelanocortin are co-secreted with the C-terminal peptide beta-endorphin during acute haemorrhagic stress in sheep.