Socio-economic status and blood pressure: an overview analysis

It is now widely accepted that both the design and the operating conditions at articular surfaces in total joint replacements influence the magnitude of the contact stress at those surfaces. In turn, such stress plays a pivotal role in the clinical performance of the prosthesis. Hence, a plethora of methods have been used by many workers not only to determine or estimate this stress but also to identify the main influencing factors. This literature is critically reviewed in the present study, which is in two parts. In this first part, the focus is on experimental methods. Two main recommendations emerge from this review. First, the pressure-sensitive film should be used. Second, more work is needed in many areas, an example of which is the effect of the method of sterilization of tibial inserts on the contact stress at the tibiofemoral interface in knee implants.     

The influence of some perinatal variables on neonatal blood pressure

Adult hypertension has been linked to fetal growth. This study investigates whether this link is evident in the newborn. We measured blood pressure by oscillometry in 248 healthy neonates on day 3/4 of life. Antenatal data and neonatal measurements were obtained from hospital records. Elevated neonatal blood pressure correlated with higher birthweight. There was no correlation between placental weight and blood pressure. Babies born by caesarean section had lower systolic blood pressure. Babies of maternal smokers had higher diastolic blood pressure, but their mothers (45% of this study) had lower blood pressure than non-smokers. Thus, smoking was associated with a significant change in both maternal and neonatal blood pressure, and may be an important influence on the developing cardiovascular system.     

Adrenoceptors on blood cells in patients with primary hypertension: correlation with blood pressure and related variables

OBJECTIVE: Alterations in platelet alpha 2-adrenoceptor and mononuclear leucocyte beta 2-adrenoceptor characteristics in primary hypertension have been extensively studied. The results of the reports have not been consistent, possibly because of the small number of subjects in most of the studies. We therefore studied the blood-cell adrenoceptor characteristics in a relatively large group of primary hypertensive and normotensive subjects. DESIGN: Platelet alpha 2-adrenoceptor characteristics were compared in 65 hypertensive and 51 normotensive subjects. Mononuclear leucocyte beta 2-adrenoceptor characteristics were compared in 72 hypertensives and 67 normotensives. Untreated hypertensive subjects were selected from the outpatient clinic and the normotensive controls were recruited by a newspaper announcement. METHODS: Platelets and mononuclear leucocytes were isolated from blood samples obtained after at least 10 min supine rest. The alpha 2- and beta 2-adrenoceptor characteristics were determined with [3H]-rauwolscine and [125I]-(-1)cyanopindolol, respectively. Correlations between the adrenoceptor characteristics and clinical parameters of the subjects were studied. RESULTS: No differences in alpha 2- or beta 2-adrenoceptor densities were observed between the two groups. However, a significantly lower equilibrium dissociation constant for [3H]-rauwolscine was observed in the hypertensive group. The correlations between the adrenoceptor characteristics and clinical parameters were weak and mostly not statistically significant. The results were compared with the most relevant studies in the literature. CONCLUSIONS: From our study and the literature, we conclude that blood-cell adrenoceptor characteristics are unchanged in primary hypertension.     

Long-term persistence of relaxation-induced blood pressure lowering during the working day.

30 hypertensive Ss (mean age 49.9 yrs) who had been randomly allocated to either relaxation training or to blood pressure monitoring were followed up 15 mo after treatment. Ss receiving relaxation training showed significantly greater lowering of diastolic blood pressure than the control group both in the clinic and during the working day, demonstrating long-term persistence of the effect of relaxation training. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

rhDNase as an example of recurrent event analysis

We consider counting process methods for analysing time-to-event data with multiple or recurrent outcomes, using the models developed by Anderson and Gill, Wei, Lin and Weissfeld and Prentice, Williams and Peterson. We compare the methods, and show how to implement them using popular statistical software programs. By analysing three data sets, we illustrate the strengths and pitfalls of each method. The first example is simulated and involves the effect of a hidden covariate. The second is based on a trial of gamma interferon, and behaves remarkably like the first. The third and most interesting example involves both multiple events and discontinuous intervals at risk, and the three approaches give dissimilar answers. We recommend the AG and marginal models for the analysis of this type of data.     

Blood pressure analysis by means of an ultrasonic blood pressure monitor during the course of rehabilitative treatment (author's transl)

A statistic evaluation of the daily blood pressure values at rest during a 4-week period of active training combined with physiotherapy and medical baths indicated a decrease of 20 mm Bg in systolic pressure and of 9 mm Hg in diastolic pressure in patients with hypertension of various grades. The resting blood pressure shows a tendency to become normalized during the course of this therapy with phases of maximum negative decline. However, a standardized simple submaximla ergometric load test carried out weekly demonstrated that there were only minimal changes in systolic and diastolic blood pressure during exercise. In comparison with observations made in other spas, these results demonstrate a uniform reaction of the human organism to this particular form of irritative therapy independent of the particular features of the spas and the special constituents of the waters.     

The determinants of long-term blood pressure stability: control of trough blood pressure during sleep

Little is known regarding the prevalence and course of fatigue in cancer patients after treatment has ended and no recurrence found. The present study examines fatigue in disease-free cancer patients after being treated with radiotherapy (n = 154). The following questions are addressed. First, how do patients describe their fatigue 9 months after radiotherapy and is this different from fatigue in a nonselective sample from the general population (n = 139)? Secondly, to what degree is fatigue in patients associated with sociodemographic, medical, physical and psychological factors? Finally, is it possible to predict which patients will suffer from fatigue 9 months after radiotherapy? Results indicated that fatigue in disease-free cancer patients did not differ significantly from fatigue in the general population. However, for 34% of the patients, fatigue following treatment was worse than anticipated, 39% listed fatigue as one of the three symptoms causing them most distress, 26% of patients worried about their fatigue and patients' overall quality of life was negatively related to fatigue (r = -0.46). Fatigue in disease-free patients was significantly associated with: gender, physical distress, pain rating, sleep quality, functional disability, psychological distress and depression, but not with medical (diagnosis, prognosis, co-morbidity) or treatment-related (target area, total radiation dose, fractionation) variables. The degree of fatigue, functional disability and pain before radiotherapy were the best predictors of fatigue at 9-month follow-up, explaining 30%, 3% and 4% of the variance respectively. These findings are in line with the associations found with fatigue during treatment as reported in the preceding paper in this issue. The significant associations between fatigue and both psychological and physical variables demonstrate the complex aetiology of this symptom in patients and point out the necessity of a multidisciplinary approach for its treatment.     

Segregation analysis reveals a major gene effect controlling systolic blood pressure and BMI in an Israeli population

It has been suggested that genetic factors control blood pressure level at all ages. However, the evidence is limited because of the composite nature of blood pressure and the heterogeneity of the studied samples. The purpose of the present study is to test for genetic influences on systolic blood pressure (SBP) level in a community-based Israeli family study. Segregation analysis was performed on 622 adults from 208 pedigrees. Age, sex, and body mass index (BMI) were significant covariates of SBP. Segregation analysis rejected the environmental transmission model but not the mixed Mendelian transmission model. The best-fitting genetic model was the mixed codominant model, with a heritability of 0.32 and an allele frequency of 0.18 for high SBP level. We further tested whether SBP and BMI shared a common major gene effect. Using bivariate segregation analysis involving two traits and a single locus, we found evidence for a single-locus pleiotropic effect on SBP and BMI. The allele frequency of this major locus was 0.24. The residual genetic correlation resulting from additive polygenes and the environmental correlation between these two traits were not different from zero after taking into account the shared major gene effect. The proportion of phenotypic variation attributable to this major gene effect increased with age for SBP but decreased with age for BMI.     

Normal values for ambulatory blood pressure and differences between casual blood pressure and ambulatory blood pressure: results from a Danish population survey

Oncogenic forms of the Abl and Src tyrosine kinases trigger the destruction of the Abi proteins, a family of Abl-interacting proteins that antagonize the oncogenic potential of Abl after overexpression in fibroblasts. The destruction of the Abi proteins requires tyrosine kinase activity and is dependent on the ubiquitin-proteasome pathway. We show that degradation of the Abi proteins occurs through a Ras-independent pathway. Significantly, expression of the Abi proteins is lost in cell lines and bone marrow cells isolated from patients with aggressive Bcr-Abl-positive leukemias. These findings suggest that loss of Abi proteins may be a component in the progression of Bcr-Abl-positive leukemias and identify a novel pathway linking activated nonreceptor protein tyrosine kinases to the destruction of specific target proteins through the ubiquitin-proteasome pathway.     

Endogenous sodium pump inhibitors and blood pressure regulation: an update on recent progress

Rapid progress has occurred recently in understanding the origin, chemistry, synthesis, control, and actions of endogenous materials that may be ligands for the cardiac glycoside binding site on the mammalian sodium pump (Na,K-ATPase). The present paper reviews this progress and examines in detail the evidence supporting ouabain-like and bufodienolide-like compounds as functioning in endogenous control of sodium pump activity, renal sodium excretion, blood pressure, and cardiovascular contractility. Other novel compounds identified in this search as potentially influencing natriuresis and blood pressure are also discussed.     

Accuracy of an automated blood pressure device in stable inpatients: optimum vs routine use

OBJECTIVES: The review lists the child psychiatry day-care centres in Quebec, evaluates their capacity, and describes them according to the age range for admission, the psychopathologies treated, and the parent involvement required. METHOD: The 26 programs selected, which are all associated with a hospital centre, assess and treat children aged 0 to 12 years on a day-care basis. Organization, clinical operation, and research are addressed during a semisupervised interview. RESULTS: The average capacity is 18 children (4 to 40), with a total capacity of 454 children. The number of preschool patients can be compared with the number of school patients. Few programs are dedicated to invasive development disorders, and one-third treat behavioural or emotional disorders. The larger capacity programs treat patients of both genders. Most programs are eclectic and encourage but do not require parental involvement. CONCLUSIONS: Results take into account different theoretical influences, the controversy about integration criteria and parent involvement, and the specificity of the child psychiatry mission.     

Cochlear implants in children: an analysis of use over a three-year period

OBJECTIVE: This study aimed to determine whether children continue to wear their cochlear implant systems 1 and 3 years after implantation. STUDY DESIGN: The design was a prospective study based on the analysis of forced-choice questionnaires on implant use completed independently by parents and teachers. SETTING: The study was performed at a dedicated pediatric cochlear implant program in a tertiary referral center in the United Kingdom. PATIENTS: All 85 consecutively implanted children who had reached the 1-year interval after implantation and 37 children who had reached the 3-year assessment interval after implantation participated. The patients represented all socioeconomic status groups, the entire range of educational settings, and often lived at a considerable distance from the implant center. MAIN OUTCOME MEASURES: Parents and local teachers were asked to describe implant use in the following categories: 1) all of the time; 2) most of the time; 3) some of the time; and 4) none of the time. RESULTS: One year after implantation, parents and teachers, respectively, rated 79 (93%) and 82 (96%) children as full-time users (category 1). Parents rated six children (7%) as users most of the time (category 2), and teachers rated three children (4%) as users most of the time. No child was rated as an occasional or nonuser (category 3 or 4). At 3 years after implantation, 33 (89%) and 34 (95%) children were rated as full-time users (category 1) by parents and teachers, respectively. Parents judged four children (11%) and teachers rated two children (5%) to be users most of the time (category 2). Again, no child was rated in category 3 or 4 as an occasional or nonuser. CONCLUSIONS: The majority of implanted children use their implant systems all of the time over a 3-year period after implantation when selected appropriately and given appropriate follow-up.     

White coat effect detected using self-monitoring of blood pressure at home: comparison with ambulatory blood pressure

The objective of the study was to investigate whether home blood pressure (HBP) is a reliable alternative to ambulatory blood pressure (ABP) for the detection of the white coat effect (WCE). Hypertensive patients were randomized to measure HBP for 2 weeks or ABP for 24 h. The alternative measurement was then performed. Clinic blood pressure (CBP) was measured in the beginning and end of the study. Subjects with a difference of > or = 20 mm Hg systolic or > or = 10 mm Hg diastolic BP between CBP and awake ABP or CBP and HBP, were classified as clinic reactors. A total of 189 patients completed the study (79 on stable antihypertensive treatment). There was no difference in the magnitude of WCE assessed using the ABP or the HBP method (mean discrepancy, systolic BP: -1.5 +/- 11.7 mm Hg, 95% CI -3.2, 0.2; diastolic BP: 0.9 +/- 7.0, 95% CI -0.1, 1.9). A strong association existed between WCE calculated using the HBP or the ABP method (r = 0.64/0.59 systolic/diastolic, P < .001). The proportion of patients classified as clinic reactors was identical using the HBP or the ABP method (25.9%). Agreement between methods in the classification of clinic reactors was found in 147 patients (78%). The sensitivity and specificity of the HBP method to classify correctly clinic reactors (ABP method used as the standard) were 57% and 85%, respectively, whereas its positive and negative predictive value were 57% and 85%. These results indicate that HBP is not appropriate as an alternative to ABP diagnostic testing in the detection of WCE. Nevertheless, HBP appears useful as a screening test for the detection of this phenomenon.     

Agonist-induced calcium waves in oscillatory cells: a biological example of Burgers' equation

Oscillations in cytosolic Ca2+ concentrations in living cells are often a manifestation of propagating waves of Ca2+. Numerical simulations with a realistic model of inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ wave trains lead to wave speeds that increase linearly at long times when (a) IP3 levels are in the range for Ca2+ oscillations, (b) a gradient of phase is established by either an initial ramp or pulse of IP3, and (c) IP3 concentrations asymptotically become uniform. We explore this phenomenon with analytical and numerical methods using a simple two-variable reduction of the De Young-Keizer model of the IP3 receptor that includes the influence of Ca2+ buffers. For concentrations of IP3 in the oscillatory regime, numerical solution of the resulting reaction diffusion equations produces nonlinear wave trains that shows the same asymptotic growth of wave speed. Due to buffering, diffusion of Ca2+ is quite slow and, as previously noted, these waves occur without appreciable bulk movement of Ca2+. Thus, following Neu and Murray, we explore the behavior of these waves using an asymptotic expansion based on the small size of the buffered diffusion constant for Ca2+. We find that the gradient in phase of the wave obeys Burgers' equation asymptotically in time. This result is used to explain the linear increase of the wave speed observed in the simulations.     

Interleukin 1 (IL-1) and IL-1-receptor antagonist (IL-1-RA) in middle ear cholesteatoma: an analysis of protein production and biological activity

Cytokine networks are now presumed to play an essential role in the pathogenesis of middle ear cholesteatoma. Of the factors identified in cholesteatoma, interleukin-I (IL-1)-alpha appears to be especially important because of its stimulation of keratinocyte proliferation as well induction of bone resorption. To further characterize the possible role of IL-1 in the pathogenesis of cholesteatoma, we quantified the levels of IL-1 and IL-1-receptor antagonist (IL-1-RA) present using the bicinchonic acid protein assay and enzyme-linked immunosorbent assay (ELISA) on tissue extracts from 20 cholesteatoma specimens. The presence of biologically active IL-1 was also analyzed, using the cell line LBRM-33 and an ELISA for the detection of interleukin-2 (IL-2). Human skin obtained from the external ear canal was used as control. The amounts of IL-1-alpha in cholesteatoma (34.9 +/- 19.5) were higher than in human skin (6.7 +/- 2.8). The observed differences were statistically significant by Student's t-test (P < 0.01). Skin samples showed elevated concentrations of IL-1-RA (248.3 +/- 30.2) in comparison to that in the cholesteatoma (80.8 +/- 13.5). This was also statistically significant (P < 0.01). Whereas IL-1 activity was not detected in skin samples, all cholesteatoma specimens studied showed a stimulation effect on the production of IL-2 when incubated with the cell line LBRM-33. The results point to an over-expression of IL-1 concurrent with a decreased secretion of IL-1-RA in middle ear cholesteatoma. Furthermore IL-1-RA production is deficient relative to total IL-1 production, resulting in the presence of active IL-1.