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Biomedical subjects

G Rose

Publications and source records attributed to G Rose.

At least 19 recordsLinked to original sources
PubMed1995

The influence of flavor and color on drink identification by children and adults.

This study investigated how color and flavor influences drink identification by children and adults. The children ranged in age from 2 to 18 years of age. Each subject tasted four drinks that differed in color and flavor. Each drink had an atypical color-flavor pairing (e.g., brown-pineapple) or a typical pairing (e.g., brown-chocolate). After tasting each drink, the subject chose which of four flavor names identified the drink. For the atypical drinks, the selection of color-associated names (e.g., chocolate for a brown drink) decreased, and the selection of flavor-associated names increased with age from the preschoolers to the adults. For the typical drinks, the selection of the correct name was greater than 80% for all ages. These results suggest that drink identification becomes more influenced by flavor as children get older because of an increase in the ability of children to focus on flavor as their perceptual-attentional skills mature.

Adolescent↗
PubMed1995

Cooperative effects of neuronal ensembles.

Electrophysiological properties of neurons as the basic cellular elements of the central nervous system and their synaptic connections are well characterized down to a molecular level. However, the behavior of complex noisy networks formed by these constituents usually cannot simply be derived from the knowledge of its microscopic parameters. As a consequence, cooperative phenomena based on the interaction of neurons were postulated. This is a report on a study of global network spike activity as a function of synaptic interaction. We performed experiments in dissociated cultured hippocampal neurons and, for comparison, simulations of a mathematical model closely related to electrophysiology. Numeric analyses revealed that at a critical level of synaptic connectivity the firing behavior undergoes a phase transition. This cooperative effect depends crucially on the interaction of numerous cells and cannot be attributed to the spike threshold of individual neurons. In the experiment a drastic increase in the firing level was observed upon increase of synaptic efficacy by lowering of the extracellular magnesium concentration, which is compatible with our theoretical predictions. This "on-off" phenomenon demonstrates that even in small neuronal ensembles collective behavior can emerge which is not explained by the characteristics of single neurons.

Animals↗
PubMed1995

Quantitative assessment of exposure to dog (Can f 1) and cat (Fel d 1) allergens: relation to sensitization and asthma among children living in Los Alamos, New Mexico.

BACKGROUND: Our objective was to identify the allergens associated with asthma among schoolchildren in an area of the United States where dust mite growth is expected to be poor. Los Alamos, N.M., was chosen because it has low rainfall and is at high altitude (7200 feet) making it very dry. One hundred eleven children (12 to 14 years old) from the middle school who had been previously classified according to bronchial hyperreactivity to histamine (BHR) were studied. METHODS: Sera were assayed for IgE antibodies to mite, cat, dog, cockroach, Russian thistle, and grass pollen, with both CAP system fluoroimmunoassay (Kabi Pharmacia, Uppsala, Sweden) and conventional RAST. Allergens were measured in dust samples from 108 homes with two-site assays for mite (Der p 1 and Der f 1), cat (Fel d 1), dog (Can f 1), and cockroach (Bla g 2). RESULTS: Concentrations of dog and cat allergens were elevated in almost all houses with pets but were also high in a significant proportion of the houses without pets. Levels of mite allergen were less than 2 micrograms/gm in 95% of the houses, and cockroach was undetectable in all but two of the houses. Among the 21 with BHR who had symptoms, 67% had IgE antibody to dog and 62% had IgE antibody to cat. For these allergens IgE antibody was strongly associated with asthma (p < 0.001). By contrast, the presence of IgE antibody to mite, cockroach, or grass pollen was not significantly associated with asthma. CONCLUSION: The high prevalence of IgE antibody to cat and dog allergens among these children is in keeping with the presence of cat and/or dog allergen in most of the houses. Furthermore, sensitization (as judged by IgE antibodies) to cat and dog allergens was strongly associated with asthma. On the other hand, no clear relationship was found between sensitization or symptoms and the current level of allergen in individual houses. The results show that in this mite-and cockroach-free environment sensitization to domestic animals was the most significant association with asthma.

Adolescent↗
PubMed1995

Someone who cares--patients' experiences concerning health examinations.

The aim of this inquiry was to gain an understanding of laymen's experiences and opinions about general health check-ups. Medical experts often draw attention to unwanted effects, especially the risk of creating worry and of recommending and even giving unnecessary medical treatment. By using a qualitative research method with unstructured interviews we wanted to explore the participants' conceptions of health, their expectations before and their perceived benefits after health checks and whether the check-up gave rise to negative feelings. The participants held broad views on health and, possibly as a consequence, also great expectations of health check-ups. Consequences of the check-ups were that examinees felt encouraged to change their life style, had learnt to handle risk factors for disease, and after some time, reported feeling better. The individual attention and care, which in general did not differ from other caring situations described in the literature, was highlighted as an important factor for a positive result. Worries afterwards either did not exist or could be rationalized by knowing the causes of abnormalities and receiving guidance from the medical staff.

Adult↗
PubMed1995

Cerebral microembolism and the risk of ischemia in asymptomatic high-grade internal carotid artery stenosis.

BACKGROUND AND PURPOSE: Previous work has shown that cerebral microembolism detected with transcranial Doppler sonography distal to internal carotid artery stenosis occurs more frequently in recently symptomatic compared with asymptomatic patients. It has remained unclear whether cerebral microembolism also indicates a higher risk of future cerebral or retinal ischemia. SUMMARY OF REPORT: Sixty-four asymptomatic patients with unilateral 70% to 90% internal carotid artery stenosis were investigated prospectively (mean follow-up, 72 weeks). Five patients developed ischemic symptoms attributable to the stenosis (transient ischemic attack, 2 patients; stroke, 3 patients). A microembolic rate of > or = 2 per hour in the ipsilateral middle cerebral artery was associated with a substantially increased risk of developing ischemia of the corresponding carotid territory (odds ratio, 31; 95% confidence interval, 3 to 302; P = .005). CONCLUSIONS: This prospective pilot study suggests that cerebral microembolism detected with transcranial Doppler sonography may define a high-risk subgroup among patients with asymptomatic high-grade internal carotid artery stenosis.

Aged↗
PubMed1995

Cheyne-Stokes respiration in ischemic stroke.

We monitored breathing pattern and arterial oxygen saturation in 32 conscious patients with acute ischemic stroke. Seventeen (53%) had Cheyne-Stokes respiration with concomitant drops in oxygen saturation, unrelated to infarct location. The ventilatory disturbance promptly reversed after intravenous theophylline ethylenediamine or oxygen inhalation. The therapy is a simple way of improving arterial oxygenation in a large subgroup of patients with acute ischemic stroke.

Adult↗
PubMed1994

Alcohol and blood pressure: the INTERSALT study.

OBJECTIVES: To assess the relation between alcohol intake and blood pressure in men and women and in men at younger and older ages; to examine the influence of amount and pattern of alcohol consumption, as well as of acute effects, taking into account body mass index, smoking, and urinary sodium and potassium excretion. DESIGN: Subjects reported alcohol consumption for each of seven days before standardised blood pressure measurement, and whether they had consumed any alcohol in the 24 hours before measurement. SETTING: 50 centres worldwide. SUBJECTS: 4844 men and 4837 women aged 20-59. MAIN OUTCOME MEASURES: Effect of alcohol on blood pressure estimated by taking a weighted average of regression coefficients from centres. Acute effect assessed by examining mean differences in blood pressure of non-drinkers and of heavy drinkers who had and had not consumed alcohol in the 24 hours before measurement. Effect of pattern of consumption assessed by examining mean differences in blood pressure of non-drinkers compared with drinkers (i) whose intake was concentrated in fewer days or who were drinking more frequently, and (ii) whose alcohol intake varied little over the seven days or varied more substantially, as indicated by the standard deviation of daily consumption. RESULTS: Of the 48 centres in which some people reported consuming at least 300 ml/week of alcohol, 35 had positive regression coefficients linking heavy alcohol consumption to blood pressure. Overall, alcohol consumption was associated with blood pressure, significantly at the highest intake. After account was taken of key confounders, men who drank 300-499 ml alcohol/week had systolic/diastolic blood pressure on average 2.7/1.6 mmHg higher than non-drinkers, and men who drank > or = 500 ml alcohol/week had pressures of 4.6/3.0 mmHg higher. For women, heavy drinkers (> or = 300 ml/week) had blood pressures higher by 3.9/3.1 mmHg than non-drinkers. Heavy drinking and blood pressure were strongly associated in both sexes, and in men at both younger (20-39 years) and older (40-59 years) ages. In men who were heavy drinkers, episodic drinkers (those with great variation in daily alcohol consumption) had greater differences in blood pressure compared with non-drinkers than did regular drinkers of relatively constant amounts. CONCLUSION: The significant relation of heavy drinking (3-4 or more drinks/day) to blood pressure, observed in both men and women, and in younger and older men, was independent of and added to the effect on blood pressure of body mass index and urinary excretion of sodium and potassium. The findings indicate the usefulness of targeting those at high risk as well as the general population to reduce the adverse effects of alcohol on blood pressure.

Adult↗
PubMed1994

The assessment of biological age: a report from the Department of Environment Study.

Indicators of ageing were measured in 397 male and 130 female London Civil Servants aged from 37 to 58 years of age. Grey hair, skin inelasticity, and arcus senilis were strongly and independently related to chronological age. Also independently related were serum albumin (negatively related in both sexes), baldness, serum creatinine, systolic blood pressure, serum calcium (negatively) and ESR in men, and serum cholesterol in women. Chronological age was regressed on the above variables for men and women separately to provide regression equations. Biological age for an individual was calculated by entering his or her results and calculating the residuals. Biological age in those who stopped smoking tended to be younger than chronological age by an average of 12-13 months in men and 1-4 months in women. Men and women who had never smoked had higher biological than actual ages but not after adjusting for regression dilution bias. Men who currently smoked had higher biological ages of 2-3 months but not women smokers (4-6 months lower). Similarly, men of lower employment grades had an average biological age 13 months older and women 8 months, compared with higher employment grades. These differences between employment grade appeared to be due to ESR, arcus senilis, systolic blood pressure and serum cholesterol. These four measurements may be markers of biological rather than chronological age, and the value of attempting to measure biological age is discussed.

Adult↗
PubMed1994

Chemical treatment of carpets to reduce allergen: a detailed study of the effects of tannic acid on indoor allergens.

Tannic acid (TA), a protein-denaturing agent, has been reported to reduce allergen levels in house dust and is marketed for that purpose as 1% and 3% solutions. We investigated the effects of TA on dust allergens by using monoclonal antibody-based ELISAs for mite (Der p I, Der f I, and group II) and cat (Fel d I) allergens. Initial studies confirmed that TA reduced allergen levels in carpet dust. However, when dust samples from treated carpets are extracted in saline solution, residual TA redissolves and may interfere with the assessment of allergens. In the laboratory, concentrations of TA as low as 0.1% inhibited the assays, but this effect may be prevented by addition of 5% bovine serum albumin (BSA). After treatment of dust samples in the laboratory with 3% TA, the apparent reductions in Der p I and Der f I levels were 89% and 96%, respectively, but when the samples were extracted in 5% BSA the reductions were 74% and 92%. Similar effects were seen with dust samples from carpets treated with TA. In an extreme case in which a carpet had been repeatedly treated with TA, the apparent concentration of Der p I was < 0.05 microgram/gm without BSA and 2.1 and 8.4 microgram/gm when extracted in the presence of 1% and 5% BSA, respectively. Our testing of the ability of TA to denature Fel d I demonstrated an 80% reduction in allergen, but only in samples with an initial concentration of less than 200 micrograms Fel d I/gm dust.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution, Indoor↗
PubMed1994

Real-time identification of cerebral microemboli with US feature detection by a neural network.

PURPOSE: Abnormal transcranial Doppler ultrasonographic (US) signals indicating cerebral microembolism have characteristic but complex features. The authors wanted to assess the agreement among human observers and test the feasibility of an automated detection system. MATERIALS AND METHODS: Automated on-line detection of cerebral microemboli was accomplished by employing real-time overlapping Fourier transform and artificial neural network technology. By using long-term transcranial Doppler US recordings of the middle cerebral artery in consecutive cerebrovascular and cardiac patients, the method was evaluated in a clinical setting. RESULTS: The proportion of specific agreement (ps) among four experienced investigators identifying cerebral microemboli was high (mean ps, 0.91). Agreement among the neural network and the human observers was only slightly less (mean ps, 0.77). CONCLUSION: The technique allows highly reliable on-line evaluation of transcranial Doppler US recordings across multiple centers. It obviates time-consuming analyses by human observers.

Humans↗
PubMed1994

Diastolic pressure as an index of salt sensitivity.

This paper analyses the association between blood pressure and sodium excretion in 3975 individuals aged 20-74 years, selected in a probability sample survey of private households carried out in Rio Grande do Sul, Brazil. Sodium and creatinine titrations were performed in casual urine samples collected at the time of BP measurements. A subsample of 611 subjects provided 24 h urine collections. The regression slopes of systolic pressure on sodium excretion increased when diastolic level was higher. At the lowest levels of diastolic pressure the slope did not differ significantly from zero. The adjusted correlation coefficient then rose progressively to a maximum of +0.41 at diastolic pressures of 95-99 mmHg. Strikingly, at diastolic pressures of > or = 100 mmHg, there was no longer any significant association between systolic pressure and sodium excretion. These results could explain some earlier contradictory findings concerning the role of salt intake in hypertension and provide estimates of expected reduction on the prevalence of hypertension in each diastolic pressure group following a reduction on salt intake of a population.

Adult↗
PubMed1994

Renovascular resistance in primary hypertension: experimental variations detected by means of Doppler ultrasound.

OBJECTIVE: To gauge the influence of renovascular resistance changes on blood flow velocity pulsatility in kidneys of hypertensive patients by means of the ultrasonic colour and pulsed-wave Doppler method, since we have previously shown in normotensive subjects that the blood flow velocity pulsatility in renal interlobar arteries varies with changes in renovascular resistance. METHODS: In six male patients with primary hypertension, renal blood flow velocity profiles were investigated by means of duplex ultrasound. Single-kidney renovascular resistance was assessed by measurements of split renal function (gamma-camera renography), renal plasma flow (steady-state para-aminohippurate clearance) and cuff blood pressure. The pulsatility index of the blood flow velocity spectrum in the renal interlobar artery and renovascular resistance were measured either at rest, during infusion of angiotensin II, or after angiotensin converting enzyme inhibition. RESULTS: A significant correlation existed between pulsatility index and renovascular resistance (r = 0.50, P < 0.002), which did not improve after correction for the blood pressure pulsatility. Changes of pulsatility index were more closely related (r = 0.64, P < 0.001) to the corresponding changes in renovascular resistance. CONCLUSIONS: With the two-dimensional image-guided colour and pulsed-wave Doppler method it is possible to assess semiquantitatively small intra-individual changes in renovascular resistance in hypertensive patients by means of pulsatility index measurements. Pharmacologically induced alterations in renovascular haemodynamics may therefore be evaluated with this technique.

Angiotensin II↗
PubMed1993

Normality, deviance and minor psychiatric morbidity in the community. A population-based approach to General Health Questionnaire data in the Health and Lifestyle Survey.

This paper investigates factors affecting the distribution of psychiatric morbidity in the community. It identifies a close relationship between mean Chronic General Health Questionnaire (CGHQ) scores in subdivisions of a large random sample of the community (the Health and Lifestyle Survey, N = 6317) and the prevalence in these groups of abnormal, above-threshold CGHQ scores. The frequency distributions of CGHQ scores in these different populations move up and down as a whole: like other physiological and behavioural attributes, these mental health outcomes in individuals are associated with characteristics of the populations in which they arise. Populations thus carry a collective responsibility for their own mental health and well-being. This implies that explanations for the differing prevalence rates of psychiatric morbidity must be sought in the characteristics of their parent populations; and control measures are unlikely to succeed if they do not involve population-wide changes.

Adolescent↗
PubMed1993

Silent cerebral embolism caused by neurologically symptomatic high-grade carotid stenosis. Event rates before and after carotid endarterectomy.

Fourteen symptomatic patients with severe extracranial internal carotid artery stenosis (> or = 70% of luminal narrowing) were monitored using long-term transcranial Doppler ultrasonography to determine the rate of clinically silent embolism of the ipsilateral middle cerebral artery. Before carotid endarterectomy (all patients being treated with intravenous heparin), 462 such events occurred during a total monitoring time of 45 h. Statistical analyses of the inter-event intervals and of the relationship between events and cardiac cycle revealed random occurrence. While the ipsilateral events were found in each subject, silent embolism of the contralateral middle cerebral artery occurred in only four patients each of whom had angiographically proven intracranial cross-flow from the symptomatic carotid territory (39 embolic events during 7 h monitoring time). The other 10 patients showed no contralateral embolism (10 h monitoring time). Five or more days (median 10 days) after surgery and cessation of intravenous anticoagulation the ipsilateral event rate had dropped to 13 in 33 h (P < 0.001) and the contralateral rate to zero. This suggests that the stenosed arterial segment is the main source of cerebral embolism detectable with ultrasound in symptomatic patients with high-grade internal carotid stenosis, and that carotid endarterectomy substantially reduces the rate of these events. Since reduction of ipsilateral stroke risk by successful endarterectomy is known to be of a similar degree in patients as those studied here, transcranially detected embolism may represent a new marker of disease activity of extracranial carotid artery stenosis.

Adult↗