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Biomedical subjects

R Halvorsen

Publications and source records attributed to R Halvorsen.

At least 19 recordsLinked to original sources
PubMed2001

Poor CD4 T cell restoration after suppression of HIV-1 replication may reflect lower thymic function.

OBJECTIVE: To characterize immune phenotype and thymic function in HIV-1-infected adults with excellent virologic and poor immunologic responses to highly active antiretroviral therapy (HAART). METHODS: Cross-sectional study of patients with CD4 T cell rises of > or = 200 x 10(6) cells/l (CD4 responders; n = 10) or < 100 x 10(6) cells/l (poor responders; n = 12) in the first year of therapy. RESULTS: Poor responders were older than CD4 responders (46 versus 38 years; P < 0.01) and, before HAART, had higher CD4 cell counts (170 versus 35 x 106 cells/l; P = 0.11) and CD8 cell counts (780 versus 536 x 10(6) cells/l; P = 0.02). After a median of 160 weeks of therapy, CD4 responders had more circulating naive phenotype (CD45+CD62L+) CD4 cells (227 versus 44 x 10(6) cells/l; P = 0.001) and naive phenotype CD8 cells (487 versus 174 x 10(6) cells/l; P = 0.004) than did poor responders (after 130 weeks). Computed tomographic scans showed minimal thymic tissue in 11/12 poor responders and abundant tissue in 7/10 responders (P = 0.006). Poor responders had fewer CD4 cells containing T cell receptor excision circles (TREC) compared with CD4 responders (2.12 versus 27.5 x 10(6) cells/l; P = 0.004) and had shorter telomeres in CD4 cells (3.8 versus 5.3 kb; P = 0.05). Metabolic labeling studies with deuterated glucose indicated that the lower frequency of TREC-containing lymphocytes in poor responders was not caused by accelerated proliferation kinetics. CONCLUSION: Poor CD4 T cell increases observed in some patients with good virologic response to HAART may be caused by failure of thymic T cell production.

Adult↗
PubMed2001

The prevalence of CMA/CMPI in young children: the validity of parentally perceived reactions in a population-based study.

BACKGROUND: The present study aimed to estimate the prevalence of adverse reactions to milk, as population-based prevalence estimates based on objective diagnostic procedures are rare. METHODS: Children with parentally reported reactions to milk were selected for further examination from a population-based cohort of 2721 children. At the age of 2(1/2) years, they underwent a stepwise diagnostic procedure that included diet trials at home, skin prick tests, and open and double-blind, placebo-controlled food challenges. A sample of children with symptoms not attributed to milk was selected for assessment of unrecognized reactions. RESULTS: The estimated point prevalence of cow's milk allergy and cow's milk protein intolerance (CMA/CMPI) in children with parentally perceived reactions at the age of 2(1/2) years was estimated to be 1.1% (CI 0.8-1.6). However, this was an underestimate, as unrecognized reactions were detected. Most reactions were not IgE-mediated. The positive predictive value of a parentally perceived reaction depended on the number of times it had been reported and was good for reactions reported three times (at 12, 18, and 24 months of age). CONCLUSION: The present study confirms previous findings that parents overestimate milk as a cause of symptoms in their children; however, it also indicates that unrecognized reactions may be a problem as well.

Age Distribution↗
PubMed2001

The prevalence of allergy to egg: a population-based study in young children.

BACKGROUND: The aim of the present study was to estimate the prevalence of adverse reactions to egg, as population-based prevalence estimates based on objective diagnostic procedures are lacking. METHODS: The parents of 2721 children in a population-based birth cohort completed questionnaires on the occurrence of any reaction to food at 12, 18, and 24 months of age. Children with parentally reported reactions to eggs at the age of 2 years were selected for further examination. A stepwise diagnostic procedure was developed that included diet trials at home, skin prick tests, and open and double-blind, placebo-controlled food challenges. The mean age of the children at the time of the examination was 2.5 years (CI 2.5-2.6). A sample of children without perceived reactions to egg was also selected for assessment of unrecognized reactions. RESULTS: The estimated point prevalence of allergy to egg in children aged 2(1/2) years was 1.6% (CI 1.3-2.0%), with an upper estimate of the cumulative incidence by this age calculated roughly at 2.6% (CI 1.6-3.6). Almost all reactions were IgE mediated. In general, two-thirds of the parentally perceived reactions were verified. However, the positive predictive value of a parentally perceived reaction depended on the number of times it had been reported, and increased from 50% to 100%, for reactions reported one and three times, respectively. Unrecognized reactions were infrequent. CONCLUSION: This study confirms that allergy to egg is frequent in a child population.

Age Distribution↗
PubMed2001

Comparison of patients' experiences during imaging tests of the colon.

BACKGROUND: Physical discomfort, anxiety, embarrassment, and other aspects of patient experience impact on future compliance for colonic imaging tests. Therefore, a prospective study was performed comparing patient experiences during air contrast barium enema (ACBE), flexible sigmoidoscopy, and colonoscopy. METHODS: Immediately after each procedure, patients completed a questionnaire assessing pretest anxiety, difficulty with preparation, pain, cramping, bloating, overall discomfort, loss of dignity, willingness to repeat the test, and overall satisfaction. A follow-up questionnaire was administered within 48 hours. Nurses and physicians also completed questionnaires to assess the provider impression of patient experience. RESULTS: Four hundred ten patients (80 ACBE, 202 sigmoidoscopy, 128 colonoscopy) were prospectively enrolled. Sigmoidoscopy caused more pain than ACBE (Odds ratio [OR] 2.64: 95% CI [1.63, 4.27]) or colonoscopy (OR 1.83: 95% CI [1.21, 2.77]). ACBE and colonoscopy did not differ in the degree of pain. Although overall satisfaction appeared to be similar for all tests, patients were less willing to repeat ACBE than sigmoidoscopy (OR 1.85: 95% CI [1.13, 3.02]) or colonoscopy (OR 1.82: 95% CI [1.07, 3.09]). Initial and follow-up pain ratings by patients were highly correlated (Spearman correlation 0.81); however, correlation of pain assessments between staff and patients was poor (Spearman correlation 0.48). CONCLUSIONS: Sigmoidoscopy was more painful than other colonic imaging modalities. Although ACBE and colonoscopy caused similar pain, patients were less willing to repeat ACBE. In aggregate, the data suggest that patients perceive colonoscopy as the most acceptable colonic imaging procedure. Better methods are required to allow staff to adequately assess discomfort experienced by patients during these procedures.

Adult↗
PubMed2000

Factors influencing T-cell turnover in HIV-1-seropositive patients.

HIV-1 disease is associated with pathological effects on T-cell production, destruction, and distribution. Using the deuterated (2H) glucose method for endogenous labeling, we have analyzed host factors that influence T-cell turnover in HIV-1-uninfected and -infected humans. In untreated HIV-1 disease, the average half life of circulating T cells was diminished without compensatory increases in cell production. Within 12 weeks of the initiation of highly active antiretroviral therapy (HAART), the absolute production rates of circulating T cells increased, and normal half-lives and production rates were restored by 12-36 months. Interpatient heterogeneity in the absolute degree of turnover correlated with the relative proportion of naive- and memory/effector-phenotype T cells in each of the CD4+ and CD8+ populations. The half-lives of naive-phenotype T cells ranged from 116-365 days (fractional replacement rates of 0.19-0.60% per day), whereas memory/effector-phenotype T cells persisted with half-lives from 22-79 days (fractional replacement rates of 0.87-3.14% per day). Naive-phenotype T cells were more abundant, and the half-life of total T cells was prolonged in individuals with abundant thymic tissue, as assessed by computed tomography. Such interpatient variation in T-cell kinetics may be reflective of differences in functional immune reconstitution after treatment for HIV-1 disease.

CD4-Positive T-Lymphocytes↗
PubMed2000

Nutrient intake among two-year-old children on cows' milk-restricted diets.

UNLABELLED: Approximately 2-3% of young children develop allergy or intolerance to cows' milk. The only available treatment is elimination of milk from the diet. However, as milk is an important source of nutrients in childhood, a milk-free diet may not adequately meet the child's nutritional needs. A dietary survey was conducted to assess the nutrient intake of children on cows' milk-restricted diets. A population-based sample of families with young children (31-37 mo) with adverse reaction to cows' milk and/or eggs was contacted, of which 75% agreed to complete a dietary intake assessment. Dietary intake was assessed using a 4-d weighed recording. The nutrient intake in a group of children on cows' milk protein-free (n = 16) and cows' milk reduced (n = 8) diets were compared to a group of cows' milk consumers (n = 10). There were significant differences in nutrient intake of children on milk-free diets and children consuming milk. Children on milk-free diets had significantly lower intake of energy, fat, protein, calcium, riboflavin and niacin. Use of milk substitutes improved the nutritional content of the cows' milk-free diets; however, the recommendations for riboflavin and calcium were still not met. CONCLUSION: The results reveal a risk for malnutrition in children on cows' milk-free diets, unless precautions are taken to replace the valuable nutrients from milk in the diet. Parents of children on milk-free diets need advice about food choices in order to reduce the risk of low intake of energy, fat and protein. Supplements with calcium, vitamin D and riboflavin are indicated.

Animals↗
PubMed1999

Prevalence of parentally perceived adverse reactions to food in young children.

A substantial number of parents perceive that their children have adverse reactions to food, but it is well documented that objective assessments agree with only one-quarter to one-half of parentally reported reactions. In order to prevent wrong diagnoses and curtail unnecessary or inadequate diets, primary health care providers need to deal with the parental perception of adverse reactions to food. A description of the prevalence and pattern of parentally perceived adverse reactions to food in children is needed to meet this challenge. The aim of the present study was to estimate the prevalence, incidence and cumulative incidences of parentally perceived adverse reactions to food in children younger than 2 years of age, and to study the duration of the reactions. A population-based cohort of 3623 children born in Norway was followed from birth until the age of two. At 6-month intervals, the parents completed questionnaires regarding the occurrence and type of any reaction to food. Information was available on the outcome measure at all age points for 77.4% of the families and these were used in the analyses; 3.8% of the cohort were entirely lost to follow-up. The cumulative incidence of adverse reactions to food was 35% by age two. Fruits, milk and vegetables accounted for nearly two-thirds of all reported reactions. Milk was the single food item most commonly incriminated, the cumulative incidence being 11.6%. The cumulative incidences of reported reactions to fruits and vegetables were 20.4% and 7.3%, respectively, with citrus fruits, strawberry and tomatoes as the most common food items in these groups. The cumulative incidences were less for food reactions associated with eggs (4.4%), fish (3%), nuts (2.1%) and cereals (1.4%). The duration of the reactions was short - approximately two-thirds of the reactions were not reported again 6 months later. However, the probability of remission depended on the food item concerned, the age at onset of reactions, and whether the reaction had been reported previously or not. Adverse reactions to food are reported by the parents of one-third of children in Norway before the age of two. The most striking feature of this study is the short duration of the food reactions, as approximately two-thirds of the reactions are not reported again 6 months later. Nevertheless, the high frequency of reactions attributable to milk is of concern. Milk is an important part of the Norwegian diet for children, and if removed from the diet its nutritional value is not easily replaced. Further studies are needed to assess the degree to which parents alter the diet of their children based upon perceived reactions to food.

Age Factors↗
PubMed1998

Serum inflammatory markers and effects of age and tobacco smoke exposure in young non-asthmatic children.

Serum eosinophil cationic protein (ECP), but not serum myeloperoxidase (MPO), has been found to reflect disease activity of asthma and eczema, but no reference values exist for young children. Thus, we aimed to provide values of serum-ECP and serum-MPO in young children without obstructive airways disease (OAD), and determine possible influencing factors. Parental interview was performed and serum was collected from a total of 245 children (207 children aged 24-41 months and 76 children aged 0-23 months) with no history of lower respiratory disease. Repeated serum samples were obtained in 38 subjects. Ten percent of the children had active eczema at examination. All children were controls in the "Environment and Childhood Asthma" study in Oslo. Geometric means (GM +/- 1.96 SD) for serum ECP were 11.8 microg/l (2.5-56.0) and 7.9 microg/l (2.0-30.4), respectively, in the 0-23 and 24-41-month-old children, with the corresponding values for serum MPO 453 microg/l (153-1349) and 347 microg/l (142-859), respectively. Age was inversely associated with serum-ECP and serum-MPO, most pronounced in the youngest children. Active eczema and maternal daily smoking adversely affected serum-ECP, but not serum-MPO. Gender and parental atopy did not influence the results. We conclude that serum-ECP in very young children is influenced by age and active eczema and is related to maternal smoking in a dose-dependent fashion. These factors should be considered when assessing inflammatory markers in very young children.

Age Factors↗
PubMed1998

The ambiguity of lesbian and gay marriages: change and continuity in the symbolic order.

The article discusses the Registered Partnership Act, passed in Norway in 1993, which has given gay and lesbian couples a right to register their relationship and to obtain many of the legal rights that heterosexual couples have. The article argues that the introduction of the Act is a product of, among others, cohabitation having become more legitimate as a life-form also among heterosexuals. The practical consequences of the Act have been modest, with relatively few couples having registered their relationship. The article suggests that the symbolic rather than the practical aspects of the Act have been important, and even then, the symbolic effect of the Act is equivocal. The new formal rights of gays and lesbians are of decreasing social and symbolic value, as new boundaries for legitimate life-forms are being demarcated elsewhere: While legislation on marriage concedes that personal relationships are a private matter, the right to have and to foster children is regarded as an issue where society at large should have a say. This view is also reflected in the restrictions that the Registered Partnership Act has placed on gay and lesbian couples in having children of their own.

Family↗
PubMed1997

Prevalence of hemochromatosis among first-time and repeat blood donors in Norway.

BACKGROUND/AIMS: The observed prevalence of hemochromatosis has ranged considerably from 0.05 to 0.37% in studies requiring liver biopsy. We aimed to study the prevalence of genetic hemochromatosis among Norwegian blood donors. METHODS: We studied 10,552 healthy blood donors (5312 women and 5240 men) using serum ferritin as a screening parameter. If serum ferritin concentration was > or = 100 micrograms/l in women and > or = 200 micrograms/l in men, serum iron and transferrin (measured as total iron binding capacity = TIBC) were measured. Blood donors who repeatedly had a transferrin saturation above 40% and a ferritin concentration above these limits were referred to a hepatologist (H.B.). RESULTS: Serum ferritin was > or = 100 micrograms/l in 94/5312 (1.8%) women and > or = 200 microliters in 79/5240 (1.5%) men. Of these, 37 persons had a serum ferritin concentration above 100 micrograms/l (females) or above 200 micrograms/l (males) and a transferrin saturation above 40%. Nineteen of them (13 men and 6 women, median age 36 years, range 28-68) were identified as having hemochromatosis on the basis of increased hepatic iron index. Serum ferritin ranged from 111 to 1980 micrograms/l (median 357 micrograms/l and transferrin saturation from 50 to 100% (median 92%), hepatic iron from 48 to 471 mumol/g dry weight (median 118 mumol/g) and hepatic iron index from 1.5 to 12.1 (median 3.0). One person had cirrhosis and none had diabetes. The prevalence of hemochromatosis was significantly higher among first-time blood donors (12 out of 3500 [3.4/1000]) compared with repeat donors (7 out of 7052 [1/1000]), p < 0.005. CONCLUSIONS: The observed prevalence of hemochromatosis in Norwegian first-time blood donors of 0.34% is comparable to recently observed prevalences in other studies. However, the use of serum ferritin as a first-step screening tool may have failed to detect hemochromatosis in the early stage where iron overload has not yet occurred.

Adolescent↗
PubMed1997

Inflammation markers and symptom activity in children with bronchial asthma. Influence of atopy and eczema.

BACKGROUND: Eosinophil cationic protein (ECP) has been reported to reflect the eosinophil inflammatory activity in asthma. However, the relative impact of asthma symptoms and atopic eczema upon serum (s)-ECP in asthmatic children has not been established. OBJECTIVES: To examine s-ECP levels and s-myeloperoxidase (MPO) in relation to asthma symptoms and atopic eczema in asthmatic children. METHODS: S-ECP and s-MPO were assessed in relation to symptom activity, lung function, exercise-induced bronchoconstriction and bronchial responsiveness in 101 children; median age 9 years, range 1-16 years; with moderate to severe asthma, admitted to Voksentoppen Center. RESULTS: S-ECP was significantly higher in children with persistent compared to episodic or no asthma symptoms in the past four weeks. S-ECP was also higher in children with atopic compared to non-atopic asthma, as well as in those with active compared to past history or no history of atopic eczema. S-MPO was higher in children with persistent asthma symptoms, but did not differ in relation to atopy or eczema state. Persistent asthma symptoms had the greatest impact upon s-ECP levels, followed by atopy and active eczema. CONCLUSION: S-ECP may be used in assessing symptom activity in asthmatic children, but with the realisation that active eczema and the presence of atopy may also influence levels.

Adolescent↗
PubMed1995

[Reactions to food].

Adverse reactions to food occur in about 1-2% of the population, but are reported more frequently by patients. Most reactions to food are not caused by allergy. IgE-mediated food reactions are well known and of major clinical significance owing to their potentially dangerous, even life-threatening character. Adverse reactions to food can also be caused by immunological mechanisms other than IgE-mediated reactions such as, enzyme deficiencies, active pharmacological substances in food and psychological mechanisms. Double-blind provocation is the only way to diagnose a positive reaction to a food item with some certainty. Regretably no objective measures for food reactions exist.

Celiac Disease↗
PubMed1995

Meditation: a modulator of the immune response to physical stress? A brief report.

OBJECTIVE: To test the hypothesis that stress reducing techniques such as meditation alter immune responses after strenous physical stress. METHODS: The hypothesis was tested by studying six meditating and six non-meditating male runners in a concurrent, controlled design. After a period of six months with meditation for the experimental group, blood samples were taken immediately before and after a maximum oxygen uptake test (VO2max). RESULTS: The increase in CD8+ T cells after VO2max was significantly less in the meditation group than in the control group (P = 0.04). The amount of CD2+ cells doubled after VO2max, mainly because of a rise in the CD8+ fraction. CONCLUSIONS: Meditation may modify the suppressive influence of strenous physical stress on the immune system.

Adult↗
PubMed1995

Eosinophil cationic protein and tidal flow volume loops in children 0-2 years of age.

Many children with recurrent wheezing in early childhood develop asthma. Objective parameters to describe different groups of wheezers are limited, but tidal flow volume (TFV) response to inhaled salbutamol has demonstrated differences between children with and without asthma. Also, eosinophil cationic protein (ECP) has been associated with declining lung function in older children. We therefore investigated whether lung function and serum ECP (s-ECP) could differentiate between groups of wheezy young children. TFV loops were measured in 79 awake children (mean age 14 months). Minimum two wheezy episodes (mean 3.2) or minimum 4 weeks persistent wheeze were reported in 41 children (cases), whereas the 38 controls had no history of wheeze. Airways responsiveness (change in ratio of time until peak expiratory flow to total expiratory time (tPEF/tE) after inhaled nebulized salbutamol) was measured in 26 cases and 24 controls. Serum ECP and serum myeloperoxidase (s-MPO) were measured in all children. Cases had significantly lower mean tPEF/tE (0.21) than controls (0.33), and higher mean s-ECP (21.9 micrograms.L-1) than controls (14.0 micrograms.L-1). Serum ECP (but not s-MPO) correlated significantly with the percentage change in tPEF/tE from baseline (r = 0.7), but not with initial tPEF/tE. Serum ECP increased significantly with increasing immunoglobulin E (IgE), airways responsiveness and eosinophil count, but decreased with increasing age. TFV responsiveness to salbutamol and s-ECP levels correlate strongly, both probably reflecting airways inflammation, and may possibly be valuable prognostic tools in recurrent wheezy infants and toddlers.

Albuterol↗
PubMed1993

[Do we need new guidelines on iron supplementation during pregnancy?].

Studies have shown that the present official Norwegian recommendations on iron supplementation during pregnancy are not followed. A meeting was arranged in February 1993 to discuss the need to change the recommendations. The article describes the conclusions of the panel. It was proposed that the iron status of the pregnant woman, determined as serum ferritin concentration, should be measured early (before the 15th week of gestation) and iron supplement should be given as selective prophylaxis based on the serum ferritin level. The Directorate of Public Health has been asked to issue new recommendations.

Female↗
PubMed1993

[Pregnancy and iron supplementation--are the official guidelines followed?].

In the present study we have examined to what extent the national recommendations concerning iron supplements during pregnancy are being followed. 222 women in childbed were interviewed within one week after delivery concerning their intake of iron and other dietary supplements. We found that no more than 1/4 of the women were using iron supplements according to the national recommendations and that the advice given by doctors, midwives or public health nurses varied considerably. 70% of the women were recommended to take iron supplement, but no more than 66% of them were given specific advice as to which iron preparation they should take, or in what doses. The specific advice that was given varied. 93% of the women who were advised to take iron supplement followed this advice. More women took low-dose iron preparations, while more doctors recommended high-dose preparations. Only 30% of the women thought that iron supplement is vital for all pregnant women. We also found that many of the women (59%) took one or more dietary supplements, alone or in addition to iron.

Female↗