A general practice-based study examining the absolute risk of cardiovascular disease in treated hypertensive patients.

BACKGROUND: When managing hypertension, the assessment of the absolute risk of a cardiovascular' event is now advocated as the most accurate way in which the risks and benefits of anti-hypertensive therapy should be judged. Most studies that have examined control of hypertension have relied solely on the blood pressure level attained after treatment, with no measurement of the likely absolute risk in individual patients. AIM: To assess control of hypertension by quantifying the 10-year absolute risk of cardiovascular disease in patients treated by their general practitioners, and to assess which risk factors are associated with uncontrolled hypertension in this group of patients. METHOD: A cross-sectional study was made of patients on drug treatment for hypertension in 18 Oxfordshire general practices subscribing to the VAMP (value-added medical products) computer system. The absolute risk of suffering a cardiovascular event in the following 10 years was measured according to each individual's risk factor profile. Factors associated with uncontrolled hypertension were ascertained using multiple logistic regression analysis. RESULTS: Overall, 40.9% (37.6% to 44.1%) of the hypertensive population had an absolute risk exceeding 20% of having a cardiovascular event in the following 10 years. The distribution of risk factors varies throughout the population. A higher blood pressure reading was strongly associated with an increased likelihood of high absolute risk, but high blood pressure readings in individual patients did not necessarily equate to a high absolute risk. The factors independently associated with uncontrolled hypertension were age, sex, past history of stroke, ischaemic heart disease and transient ischaemic attack, a body mass index greater than 30, diabetes, and current smoking. CONCLUSIONS: Absolute risk assessment maximizes the risk-benefit ratio in treated hypertensive patients. Individual control and management requires multifactorial assessment and management. Treatment of hypertension according to blood pressure reading alone is not a reliable way of reducing the absolute risk of cardiovascular disease.     

Immunogenic glycoproteins of infectious laryngotracheitis herpesvirus

The viral glycoproteins produced in cells infected with either vaccine strain or virulent isolates of infectious laryngotracheitis virus, an avian herpesvirus, were identified by in vitro labeling using [14C]glucosamine and [14C]mannose. Chicken antisera to the vaccine strain and to a virulent isolate, and rabbit antisera to the vaccine strain, immunoprecipitated four major viral glycoproteins of 205, 115, 90, and 60K mol wt. Additional glycoprotein bands were recognized by immune chicken and rabbit sera in Western blotting using a glycoprotein fraction purified from extracts of virus-infected cells. Monoclonal antibodies to the immunogenic glycoproteins were produced and characterized by immunoprecipitation and Western blotting. One group of monoclonal antibodies reacted only with the 60K glycoprotein, by both techniques, while a second group reacted with the 205, 115, and 90K glycoproteins in immunoprecipitation and with additional bands of 85 and 160K in Western blotting.     

Immunological variability associated with experimentally-induced positive and negative affective states.

Functional and phenotypic immunological parameters were examined immediately before, after, and 30 minutes after experimentally-induced short-term positive (happiness) and negative (anxiety, depression) affective states and a neutral state, in five healthy subjects. Results indicated that all affective states induced more immune fluctuations (regardless of the direction) than the neutral state. Furthermore, among the affective states, anxiety induced the most immunological variability and depression the least.     

Contrast rectification and distributed encoding By ON-OFF amacrine cells in the retina.

The encoding of luminance contrast by ON-OFF amacrine cells was investigated by intracellular recording in the retina of the tiger salamander (Ambystoma tigrinum). Contrast flashes of positive and negative polarity were applied at the center of the receptive field while the entire retina was light adapted to a background field of 20 cd/m(2). Many amacrine cells showed remarkably high contrast gain: Up to 20-35% of the maximum response was evoked by a contrast step of only 1%. In the larger signal domain, C50, the contrast required to evoke a response 50% of the maximum, was often remarkably low: 24 of 25 cells had a C50 value of < or =10% for at least one contrast polarity. Across cells and contrast polarity, the dynamic ranges varied from extremely narrow to broad, thereby blanketing the range of reflectances associated with objects in natural environments. Although some cells resembled "contrast rectifiers," by showing similar responses to contrasts of opposite polarity, many did not. Thus for contrast gain and C50, individual cells could show a strong preference for either negative or positive contrast. In the time domain, the preference was strong and unidirectional: for equal contrast steps, the latency of the response to negative contrast was 20-45 ms shorter than that for positive contrast. The present results, when compared with those for bipolar cells, suggest that, on average, amacrine cells add some amplification, particularly for negative contrast, to the high contrast gain already established by bipolar cells. In the time domain, our data reveal a striking transformation from bipolar to amacrine cells in favor of negative contrast. These and further observations have implications for the input and output of amacrine cell circuits. The present finding of substantial differences between cells reveals a potential substrate for distributed encoding of luminance contrast within the ON-OFF amacrine cell population.     

Pharmacology of laudanosine in dogs

The authors determined the pharmacokinetics (including transfer into cerebrospinal fluid [CSF]) and the cardiovascular and central nervous system (CNS) effects of laudanosine, a metabolite of atracurium. Eight dogs were anesthetized with halothane; blood pressure and a fronto-occipital electroencephalographic lead were monitored. Laudanosine (1 mg . kg-1 iv) was administered as a bolus, and its concentrations in plasma, CSF, urine, and bile were determined by liquid chromatography. Three-compartment modeling of plasma laudanosine concentrations yielded an elimination half-life for laudanosine of 113 +/- 24 min (mean +/- SD) and a clearance of 25 +/- 8 ml . kg-1 . min-1. CSF concentrations of laudanosine were highest 5-10 min after iv injection of laudanosine and ranged in concentration from 208 to 572 ng . ml-1 (i.e., 36-87% of the corresponding plasma concentrations). Unchanged laudanosine was found in urine (0.5-12% of injected dose) and bile (less than 0.1%); metabolites of laudanosine were found in both fluids. After a 6-h sampling period, dogs were hyperventilated with halothane (FIO2 = 0.2) to a PaCO2 of 26-28 mmHg. Laudanosine was then administered 2 mg . kg-1 iv every 5 min. With cumulative doses of 2-8 mg . kg-1, all dogs showed signs of "awakening" from anesthesia. Cumulative doses of 14-22 mg . kg-1 produced seizure activity in all animals. Mean arterial blood pressure decreased significantly to 86% of control levels at 1 min following administration of laudanosine (1 mg . kg-1 iv) and returned to control levels 4 min later.(ABSTRACT TRUNCATED AT 250 WORDS)     

Unhealthy Diet Pattern Mediates the Disproportionate Prevalence of Obesity among Adults with Socio-Economic Disadvantage: An Australian Representative Cross-Sectional Study

The role of unhealthy dietary pattern in the association between socio-economic factors and obesity is unclear. The aim was to examine the association between socio-economic disadvantage and obesity and to assess mediation effect of unhealthy dietary pattern defined using the Mediterranean diet criteria. The data source was the Australian National Nutrition and Physical Activity Survey. The study sample included 7744 participants aged 18 years and over, 28% of whom had obesity. We used the Australian Socio-Economic Indexes for Areas (SEIFA) classification system for categorizing socio-economic disadvantage; calculated the Mediterranean Diet Score (MDS) using standard criteria; and used measured body mass index to define obesity. We conducted a mediation analysis using log–binomial models to generate the prevalence ratio for obesity and the proportion mediated by the MDS. The most disadvantaged group was associated with higher level of obesity after controlling for covariates (1.40, 95% CI 1.25, 1.56) compared to the least disadvantaged group, and in a dose–response way for each decreasing SEIFA quintile. The relationship between socio-economic disadvantage and obesity was mediated by the MDS (4.0%, 95% CI 1.9, 8.0). Public health interventions should promote healthy dietary patterns, such as the Mediterranean diet, to reduce obesity, especially in communities with high socio-economic disadvantage.     

Vaccination with affinity-purified glycoproteins protects chickens against infectious laryngotracheitis herpesvirus

Glycoproteins of infectious laryngotracheitis virus (ILTV) were purified from detergent extracts of virus-infected cells by lectin affinity chromatography. In these preparations, glycoproteins of 205, 160, 115, 90, 85, 74, 60 and 50 kDa were recognized by immune chicken serum in Western blotting. Vaccination of chickens with these ILTV glycoproteins protected up to 83% of chickens against replication of the challenge virus as demonstrated by the absence of viral antigen in the trachea. Both neutralizing antibody and delayed-type hypersensitivity responses were induced by vaccination with glycoprotein preparations, but neither correlated with protection.     

Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.