Randomized clinical trial of Appendicitis Inflammatory Response score-based management of patients with suspected appendicitis

BACKGROUND

The role of imaging in the diagnosis of appendicitis is controversial. This prospective interventional study and nested randomized trial analysed the impact of implementing a risk stratification algorithm based on the Appendicitis Inflammatory Response (AIR) score, and compared routine imaging with selective imaging after clinical reassessment.

METHOD

Patients presenting with suspicion of appendicitis between September 2009 and January 2012 from age 10 years were included at 21 emergency surgical centres and from age 5 years at three university paediatric centres. Registration of clinical characteristics, treatments and outcomes started during the baseline period. The AIR score-based algorithm was implemented during the intervention period. Intermediate-risk patients were randomized to routine imaging or selective imaging after clinical reassessment.

RESULTS

The baseline period included 1152 patients, and the intervention period 2639, of whom 1068 intermediate-risk patients were randomized. In low-risk patients, use of the AIR score-based algorithm resulted in less imaging (19·2 versus 34·5 per cent; P < 0·001), fewer admissions (29·5 versus 42·8 per cent; P < 0·001), and fewer negative explorations (1·6 versus 3·2 per cent; P = 0·030) and operations for non-perforated appendicitis (6·8 versus 9·7 per cent; P = 0·034). Intermediate-risk patients randomized to the imaging and observation groups had the same proportion of negative appendicectomies (6·4 versus 6·7 per cent respectively; P = 0·884), number of admissions, number of perforations and length of hospital stay, but routine imaging was associated with an increased proportion of patients treated for appendicitis (53·4 versus 46·3 per cent; P = 0·020).

CONCLUSION

AIR score-based risk classification can safely reduce the use of diagnostic imaging and hospital admissions in patients with suspicion of appendicitis. Registration number: NCT00971438 ( http://www.clinicaltrials.gov).

Influence of food on the absorption from different types of iron tablets

The influence of a standardized breakfast meal on the absorption of iron from two types of iron tablets - rapidly-disintegrating and slow-release tablets - was studied in 24 healthy subjects, using a serum iron technique and whole-body counter measurements. The meal markedly reduced the absorption of iron from both types of tablets. An 8-fold reduction was found with the rapidly-disintegrating tablets and a 3-fold reduction with the slow-release tablets. Under fasting conditions the rapidly-disintegrating tablets were significantly better absorbed than the slow-release tablets, whereas the reverse was found when the tablets were given with the meal.

Construct validity of a health questionnaire intended to measure the subjective experience of health among patients in mental health services

Mental health services have been lacking systematic health-promoting activities, and health is often perceived as the absence of disease from a biomedical perspective. It is vital to develop methods to assess perceived health among patients in a broader perspective. The aim of the study was to investigate construct validity of a newly developed health questionnaire intended to measure subjectively experienced health among patients in mental health services. A cross-sectional study, including a randomly selected sample of 139 outpatients in contact with the mental health services, was performed in order to explore the relationship between perceived health and self-reported levels of self-esteem, symptoms, empowerment, quality of life and experiences of stigmatization. Self-esteem, symptoms, empowerment and quality of life altogether accounted for 70% of the variation in overall perceived health. Overall perceived health showed positive associations to self-esteem, empowerment and quality of life and negative associations to psychiatric symptoms, discrimination and rejection experiences. The findings suggest that perceived health as measured by the health questionnaire can be a meaningful and valid construct that may be useful for measuring health in clinical mental healthcare practice and in mental health services research.

The construct validity of a self-report questionnaire focusing on health promotion interventions in mental health services

Health promotion has become a widespread concept, although little empirical research as to its importance and outcome has been performed in the mental health field. The aim of the present study was to investigate the construct validity of a newly developed Health Promotion Intervention Questionnaire, intended to measure patients' subjectively experienced health-promoting interventions within mental health services. A total of 135 participants responded to the questionnaire and to validation measures assessing psychiatric symptoms, empowerment, helping alliance and satisfaction with care. Bivariate correlations showed that overall perceived health-promoting interventions were positively correlated to, helping alliance, client satisfaction with care and empowerment. Stepwise multiple regression analysis showed that the strongest relationship was found between perceived health promotion intervention and helping alliance. In conclusion, the construct validity of the scale was satisfactory, except for one of its subscales where further investigations are needed.

Primary Health Care Nurses' conceptions of involuntarily migrated families' health

BACKGROUND

Involuntary migration and adaptation to a new cultural environment is known to be a factor of psychological stress. Primary Health Care Nurses (PHCNs) frequently interact with refugee families as migrant health needs are mainly managed within Primary Health Care.

AIM

To describe the health of the involuntary migrated family in transition as conceptualized by Swedish PHCNs.

METHOD

Thirty-four PHCNs from two municipalities in Sweden were interviewed and phenomenographical contextual analysis was used in analysing the data.

FINDINGS

Four family profiles were created, each epitomizing the health characteristics of a migrated family in transition: (1) a mentally distressed family wedged in the asylum-seeking process, (2) an insecure family with immigrant status, (3) a family with internal instability and segregated from society, and (4) a stable and well-functioning family integrated in society. Contextual socio-environmental stressors such as living in uncertainty awaiting asylum, having unprocessed traumas, change of family roles, attitudes of the host country and social segregation within society were found to be detrimental to the well-being of the family.

CONCLUSION

Acceptance and a clear place in society as well as clearly defined family roles are crucial in facilitating a healthy transition for refugee families. Primary Health Care Nursing can facilitate this by adopting a family system perspective in strengthening the identity of the families and reducing the effects of socio-environmental stressors.

Primary Health Care Nurses' conceptions of involuntarily migrated families' health

BACKGROUND

Involuntary migration and adaptation to a new cultural environment is known to be a factor of psychological stress. Primary Health Care Nurses (PHCNs) frequently interact with refugee families as migrant health needs are mainly managed within Primary Health Care.

AIM

To describe the health of the involuntary migrated family in transition as conceptualized by Swedish PHCNs.

METHOD

Thirty-four PHCNs from two municipalities in Sweden were interviewed and phenomenographical contextual analysis was used in analysing the data.

FINDINGS

Four family profiles were created, each epitomizing the health characteristics of a migrated family in transition: (1) a mentally distressed family wedged in the asylum-seeking process, (2) an insecure family with immigrant status, (3) a family with internal instability and segregated from society, and (4) a stable and well-functioning family integrated in society. Contextual socio-environmental stressors such as living in uncertainty awaiting asylum, having unprocessed traumas, change of family roles, attitudes of the host country and social segregation within society were found to be detrimental to the well-being of the family.

CONCLUSION

Acceptance and a clear place in society as well as clearly defined family roles are crucial in facilitating a healthy transition for refugee families. Primary Health Care Nursing can facilitate this by adopting a family system perspective in strengthening the identity of the families and reducing the effects of socio-environmental stressors.

Characterization of human urinary metabolites of the antimalarial piperaquine

Five metabolites of the antimalarial piperaquine (PQ) (1,3-bis-[4-(7-chloroquinolyl-4)-piperazinyl-1]-propane) have been identified and their molecular structures characterized. After a p.o. dose of dihydroartemisinin-piperaquine, urine collected over 16 h from two healthy subjects was analyzed using liquid chromatography (LC)/UV, LC/tandem mass spectrometry (MS/MS), Fourier transform ion cyclotron resonance (FTICR)/MS, and H NMR. Five different peaks were recognized as possible metabolites [M1, 320 m/z; M2, M3, and M4, 551 m/z (PQ + 16 m/z); and M5, 567 m/z (PQ + 32 m/z)] using LC/MS/MS with gradient elution. The proposed carboxylic M1 has a theoretical monoisotopic molecular mass of 320.1166 m/z, which is in accordance with the FTICR/MS (320.1168 m/z) findings. The LC/MS/MS results also showed a 551 m/z metabolite (M2) with a distinct difference both in polarity and fragmentation pattern compared with PQ, 7-hydroxypiperaquine, and the other 551 m/z metabolites. We suggest that this is caused by N-oxidation of PQ. The results showed two metabolites (M3 and M4) with a molecular ion at 551 m/z and similar fragmentation pattern as both PQ and 7-hydroxypiperaquine; therefore, they are likely to be hydroxylated PQ metabolites. The molecular structures of M1 and M2 were also confirmed using H NMR. Urinary excretion rate in one subject suggested a terminal elimination half-life of about 53 days for M1. Assuming formation rate-limiting kinetics, this would support recent findings that the terminal elimination half-life of PQ has been underestimated previously.

Interferon-beta affects the tryptophan metabolism in multiple sclerosis patients

Tryptophan and its metabolites are of great interest in understanding the pathogenesis of multiple sclerosis (MS). The total levels of tryptophan and its metabolites, kynurenine and kynurenic acid were determined in plasma by capillary liquid chromatography electrospray ionisation tandem mass spectrometry. This is the first report of the plasma levels of these analytes in healthy controls and relapsing-remitting MS patients receiving long-term and acute interferon-beta (IFN-beta) treatment. Twenty-four hours post-administration increased kynurenine levels (first IFN MS versus healthy, P = 0.042) and kynurenine/tryptophan ratio (K/T; first IFN MS versus healthy, P =0.027; first IFN MS versus long-term IFN MS, P = 0.036) were found. The long-term IFN MS group had higher K/T ratios at 4 and 12 h post-administration (P = 0.015 and 0.009, respectively). The increase of K/T ratio in the first IFN MS group indicate an induction of the enzyme indolamine-2,3-dioxygenase (IDO), as reported earlier in experimental allergic encephalomyelitis. As IDO is participating in both inflammatory and neurodegenerative processes, further knowledge of its involvement in the pathogenesis of MS is of great importance.

Body composition and bone mineral density in long-standing type 1 diabetes

OBJECTIVES

To study body composition and bone mineral density (BMD) in adult patients with long-standing type 1 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In a population-based study, body composition and BMD were evaluated by dual energy X-ray absorptiometry in 38 patients with type 1 diabetes since childhood, compared with 38 age- and sex-matched controls. The mean age was 43 years (range 33-55 years) and the mean duration of diabetes was 33 years (range 28-37 years).

RESULTS

Besides a tendency to a reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass, or BMD between the groups. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males.

CONCLUSION

Patients with long-standing type 1 diabetes with onset in childhood and adolescence seem to show only minor differences in body composition and no difference in BMD compared with closely matched healthy controls.

Nurses' conceptions of how health processes are promoted in mental health nursing

The health and well-being of the individual is a central goal in nursing, and health promotion seeks to enable people to increase control over and improve their health. In mental health care, health is often described in negative terms such as the absence of mental illness, which may create hopelessness and constitute a barrier to a policy of health promotion. The aim of this study was to describe nurses' conceptions of how health processes are promoted in mental health nursing. Twelve nurses working in mental health care were interviewed and the data were analysed using a phenomeographic approach. The nurses expressed 11 different conceptions of the phenomenon, which were summarized into three descriptive categories: presence, balance of power, and focus on health. The findings show that the nurses expressed ambiguous attitudes towards meeting the patient in mental health care. It is suggested that the goal of nursing care should be clarified for nurses in practice, otherwise they may adopt the perspectives of other mental health professionals.

Patients' conceptions of how health processes are promoted in mental health nursing. A qualitative study

The most important goal of nursing care is to promote the subjective experience of health. The health promoting efforts of mental health care nurses must be aimed at creating encounters where the patient will be confirmed both existentially and as an individual worthy of dignity. The patient in mental health care is often viewed by the nurse as nothing more than a passive recipient of care and the belief in the patient's potential is minimal. This can lead to a situation where the patient loses control in the caring situation and feels unable to improve his/her health, which conflicts with the goal of the nursing care. The aim of the study was to describe patients' conceptions of how health processes are promoted in mental health nursing. Twelve patients with experience of mental health nursing were interviewed, and the data material was analysed using a phenomenographic approach. The results show 13 different conceptions of the phenomenon, and these were summarized into four descriptive categories: interaction, attention, development and dignity. The conceptions described show that the patients need to be treated as equals and that the nurse must trust the patient's ability to make decisions and to promote his/her health process. It is suggested that mental health nursing should be built on humanistic science and its view that every individual has the ability to grow and develop. This view is one of the most important preconditions for the promotion of health processes in mental health nursing.

Bone mineral content and collagen metabolites in children receiving steroid treatment for nephrotic syndrome

Bone mineral density (BMD) and content (BMC) were measured in nine children treated with corticosteroids for nephrotic syndrome and in age-matched controls, using dual-energy X-ray absorptiometry (DEXA). The urinary excretion of cross-linked N-telopeptide (NTx) released from collagen type I as a specific marker of bone resorption was also measured. There were no significant differences in body size, BMD results or NTx urinary concentrations between patients and controls, nor could any significant differences be found when the six patients given a cumulative corticosteroid dose of >15 g were analysed separately. The lack of significant differences could be due to the small number of patients included in the study. But when the measured BMD and BMC were analysed according to methods that corrected for body size and puberty stage, values well within the normal range were found in patients as well as in controls. There was, however, a significant, negative correlation between the urinary excretion of NTx and the cumulative dose of corticosteroids.

CONCLUSION

Despite treatment for long periods with high, cumulative doses of corticosteroids, the skeletons of the patients had a normal mineral content, which is encouraging for all those in need of steroids for nephrotic syndrome. A negative correlation between urinary collagen degradation products and the cumulative steroid dose might point to a reduced growth velocity in patients on high doses of steroids earlier than an effect on bone mineralization.

Psychiatric nurses' conceptions of how a group supervision programme in nursing care influences their professional competence: a 4-year follow-up study

AIM

The aim of the study was to describe, after 4 years, psychiatric nurses' conceptions of how a 2-year group supervision programme within nursing care had influenced their professional competence.

BACKGROUND

The intention of group supervision in nursing care is to understand nurses' experiences within real care settings and to structure these in a professional and personal context.

METHODS

Ten psychiatric nurses participated in a 2-year group supervision programme. They were interviewed 4 years after the group supervision was ended. Data were analysed according to the phenomenographic method.

FINDINGS

Six description categories emerged: a feeling of job satisfaction; gaining knowledge and competence; gaining a sense of security in nursing situations; a feeling of personal development; realizing the value of supervision; and a sense of professional solidarity.

CONCLUSIONS

The findings of the 4-year follow-up showed that a group supervision programme in nursing care had lasting influences on the psychiatric nurses' professional competence in the form of a pronounced professional identity and an integrated nursing care perspective. Group supervision contributes to maintaining the strength and energy needed to carry on working, which makes continuing supervision necessary.

IMPLICATIONS

An important research implication could be to investigate the type of knowledge that ought to be developed within group supervision in nursing care.

Specific effects of eccentric and concentric training on muscle strength and morphology in humans

The purpose of this study was to compare pure eccentric and concentric isokinetic training with respect to their possible specificity in the adaptation of strength and morphology of the knee extensor muscles. Ten moderately trained male physical education students were divided into groups undertaking eccentric (ETG) and concentric (CTG) training. They performed 10 weeks of maximal isokinetic (90 degrees x s(-1)) training of the left leg, 4x10 repetitions - three times a week, followed by a second 10-week period of similar training of the right-leg. Mean eccentric and concentric peak torques increased by 18% and 2% for ETG and by 10% and 14% for CTG, respectively. The highest increase in peak torque occurred in the eccentric 90 degrees x s(-1) test for ETG (35%) whereas in CTG strength gains ranged 8%-15% at velocities equal or lower than the training velocity. Significant increases in strength were observed in the untrained contra-lateral leg only at the velocity and mode used in ipsilateral training. Cross-sectional area of the quadriceps muscle increased 3%-4% with training in both groups, reaching statistical significance only in ETG. No major changes in muscle fibre composition or areas were detected in biopsies from the vastus lateralis muscle for either leg or training group. In conclusion, effects of eccentric training on muscle strength appeared to be more mode and speed specific than corresponding concentric training. Only minor adaptations in gross muscle morphology indicated that other factors, such as changes in neural activation patterns, were causing the specific training-induced gains in muscle strength.

Food supply for settling male rock pipits affects territory size

Theory predicts that abundant food may favour larger breeding territories, provided that males could gain some important benefit, such as improved mating success or breeding performance, from keeping a large territory. The time saved when food is easy to find may be used to defend more space, unless increased defence costs offset the savings in foraging time. A previous experiment with concealed food addition close to laying did not reveal any effects on rock pipit, Anthus petrosusterritories. In this study the food intake rate of males was manipulated at the time of arrival from the winter quarters, by providing a concealed food source at the centre of each territory. The aim was to reduce foraging time, without attracting intruders, in order to isolate any effects of food abundance. Fed males had larger territories and tended to defend longer stretches of shoreline than control males. The difference in territory size was not related to male age or order of arrival. These results suggest that males settling at concentrated food sources may be able to establish large territories, and that keeping a large territory confers some advantage. We discuss possible reasons why food intake rate later during the breeding season did not affect territory size.

Cancer incidence after radiotherapy for skin haemangioma during infancy

An infant cohort treated for skin haemangioma with 226Ra between 1930 and 1965 (n = 11,807) was studied. The median age at treatment was 5-months and 88% were treated before 12 months of age. This cohort was followed up in the Swedish Cancer Registry during the years 1958 to 1989, giving 370,517 person-years at risk. A total number of 248 malignancies have been observed and the standardized incidence ratio (SIR) was 1.21 (confidence interval (CI) 95%, 1.06-1.37). Significantly increased numbers of cancers were found in the central nervous system, 34 cases (SIR = 1.85, CI 95% 1.28-2.59), the thyroid, 15 cases (SIR = 1.88, CI 95% 1.05-3.09) and other endocrine glands, 23 cases (SIR = 2.58, CI 95% 1.64-3.87). The absorbed dose in 11 specified risk organs has been estimated using a phantom of the size of a 5-6-month-old child. The mean absorbed dose in the thyroid was 0.12 Gy and the excess relative risk (ERR) for thyroid cancer was 7.5 per Gy (CI 95% 0.4-18.1). The mean dose in the central nervous system was 0.077 Gy and the ERR for brain tumours was 10.9 per Gy (CI 95% 3.7-20.5). This cohort gives a unique opportunity to analyse long-term effects of low-dose irradiation during infancy.

Body composition. Prediction of normal body potassium, body water and body fat in adults on the basis of body height, body weight and age

In 134 males and 242 females, aged 20-70 years, most of them randomly selected from population studies, the body composition was estimated from the measurements of body height (BH), body weight (BW), total body potassium (TBK) and total body water (TBW). TBK was measured with isotope dilution technique using 42K or determined as 40K in a whole body counter. TBW was determined with an isotope dilution technique using tritiated water, assayed in urine or plasma. From these data, body cell mass (BCM), intra- and extra-cellular water (ICW and ECW, resp.) and body fat (BF) were calculated for each individual. Significant correlations were found between age versus TBK, ECW, BF and ECW/ICW; between BW versus TBK, TBW, ECW, BF and ECW/ICW; (females only) and between BH versus TBK, TBW, ECW (females only) and ECW/ICW. For the prediction of TBK, TBW and BF, multiple regression equations based on BW, BH and age are given. These equations are also presented diagrammatically. The problems with the methods used are considered as well as the applicability of the formulas for the calculation of BCM etc. The predictive value of the results when both TBW and TBK are used for the calculation of body composition data is discussed and compared with similar results, based on TBW or TBK only. It is concluded, that the most reliable method for calculation of BF is to estimate both TBW and TBK.

Zinc absorption from composite meals. I. The significance of whest extraction rate, zinc, calcium, and protein content in meals based on bread

The absorption of zinc in man from composite meals based on bread was measured with a radionuclide technique using 65Zn and whole-body counting. Bread was made up from wheat flour of 100 and 72% extraction rate. A lower absolute amount of zinc was absorbed from the white bread compared to the absorption from the same amount of wholemeal bread. When the two types of bread were enriched with zinc chloride the absorption was higher from the white bread than from the wholemeal bread. Addition of calcium in the form of milk products improved the absorption of zinc from a meal with wholemeal bread. A significant positive correlation was found between zinc absorption and the protein content in meals containing milk, cheese, beef, and egg in various combinations with the wholemeal bread.

Absorption from iron tablets given with different types of meals

The absorption of iron from tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given.

Adipose tissue cellularity in obese school girls before and after dietary treatment

Mean fat cell size and adipose tissue cellularity were studied in 18 grossly obese girls and 17 age-matched reference girls. The obese girls had a combined hypertrophic-hyperplastic obesity with increments in fat cell size as well as in fat cell number. High insulin levels were found in the obese girls and the levels correlated with fat cell size. The obese girls had higher serum triglyceride levels than the reference group but the cholesterol levels were similar. After dietary treatment and advice for increased physical activity of the obese group, both groups were re-investigated with respect to adipose tissue cellularity after 1.5 to 1.9 years. Fat cell number was unchanged in the reference group while the obese girls in spite of treatment increased their cell number significantly. The obese girls who were most successfully treated had the lowest increase in fat cell number. The results suggest that treatment of childhood obesity may be of importance for the prevention of obesity later in life.

Body fat and adipose tissue cellularity in infants: a longitudinal study

Body fat, fat cell size, and fat cell number were determined in a longitudinal study on 16 normal-weight infants during the age period 1-18 mo. The methods used included whole-body counting of 40K for determination of body fat and adipose tissue biopsies. A new method of calculation of body fat in infants is presented. No sex differences were found. Body fat expressed as per cent of body weight increased from 16.2% to 28.1%. From 1 to 12 mo of age the expansion of body fat was explained by and increase in fat cell size, while in the age period 12-18 mo it was mainly due to an increase in fat cell number. At 18 mo lthe fat cell size was the same as in 8-yr-old girls and 22-yr-old women (normal-weight females previously studied). The fat cell number at 18 mo, however, was far below the number at 8 yr of age, as well as the still higher number of the 22-yr-old women.

Measurement of iron absorption from compositite meals

In earlier studies using the recently introduced extrinsic tag technique meals were carefully minced and mixed with the extrinsic tracer to ensure complete isotopic exchange. In the present paper the validity of simpler and more realistic techniques to label and serve composite meals was evaluated. Equal or almost equal absorption figures were found when mixing the label homogenously into a meal, adding it dropwise, or mixing it into the most bulky component of the meal. The necessity of serving the meals in a realistic way was underlined by the finding of higher absorption from a meal in which the components were served separately than from meals mixed before serving. The results of the present study indicate that the validity of using the reference dose as a basis for comparison of absorption data in different groups, was higher when serving the reference dose and the meals on consecutive days than when serving 2 weeks apart. This was true especially in women. The present findings imply that it is both necessary and possible to design simple labeling techniques that allow valid measurements of iron absorption from composite meals. Moreover, when determining the schedule of serving the meals and the reference doses the findings in the present paper must be carefully considered.

Iron absorption during iron supplementation in blood donors

The total amount of iron absorbed from a total supplementation of 2000 mg of iron was studied after a blood donation. 10 regular blood donors and 10 subjects without previous blood loss were included in the study. No subject had received any iron treatment before the investigation. Both groups were given one sustained release tablet containing 100 mg of iron as Fe SO4 once daily for 20 days. The iron in these tablets was labelled with 59Fe. The total amount of iron absorbed from the tablets was measured by a whole body counting technique. Laboratory tests including haematological data, desferrioxamine tests and sternal marrow punctures were made before and after the iron treatment. The non-donors lost a mean amount of 215 mg iron by phlebotomy and the total iron absorption from the tablets was only 94 mg (4.7%). In the regular blood donors the corresponding iron loss was 276 mg and the absorption was 280 mg (14%). The iron supplementation given in this study covered the iron losses in the regular blood donors but not in the non-donors. This iron prophylaxis will present a depletion but not a reduction of the iron stores in blood donors with high donation frequency.

Acetylsalicylic acid and gastrointestinal bleeding measurement of blood loss using a modified radioactive chromium method

A comparative study of the gastrointestinal blood loss during intake of a new buffered acetylsalicylic acid (ASA) preparation and plain ASA tablets has been performed. A modified radioactive chromium method was used. The 51Cr activity was considerably less than that used in previous methods, and no feces homogenization was necessary. The study was performed in 18 volunteers using a randomized crossover design. A significant reduction in gastrointestinal bleeding was registered during ingestion of the buffered ASA in comparison with the plain ASA tablets.

Dietary iron absorption in pregnancy - a longitudinal study with repeated measurements of non-haeme iron absorption from whole diet

In 22 healthy women the non-haeme iron absorption (bone-marrow smears and haematological parameters) was studied at the 12th, the 24th and the 36th week of gestation and two months after delivery. In eight non-pregnant women and in seven pregnant women (at the 36th week of gestation) the absorption of food iron was measured from different types of meals. The iron absorption was measured from radioiron-labelled test meals using a whole-body counter with a very high sensitivity. During pregnancy the non-haeme iron absorption increased continuously from less than 1 % in early pregnancy to almost 15 % in late pregnancy. Calculations indicated that the amount of iron absorbed from the diet covered only about half of the demands. The increasing absorption of food iron during pregnancy seems to be related to the still more increasing demands. However, the very low absorption values in early pregnancy was quite unexpected. The amount of iron absorbed was actually below the basal demands, which means that even in early pregnancy, for reasons unknown, there is a negative iron balance. Further studies are necessary to elucidate the significance of this finding. Two months after delivery the absorption of iron from the diet was increased compared to in non-pregnant women and exceeded the demands at that phase thus indicating that a positive iron balance was achieved.

Absorption of supplemental iron during pregnancy - a longitudinal study with repeated bone-marrow studies and absorption measurements

Iron absorption, bone-marrow smears and haematological parameters were repeatedly studied during pregnancy in 50 women. The same studies were repeated two months after delivery. The material was randomly divided into two groups. Twenty-four women were treated with 200 mg of ferrous iron daily while 26 were given placebo. The iron absorption was measured from radioiron-labelled test doses of 100 mg ferrous iron in a whole-body counter with high sensitivity. In the placebo group the iron absorption increased throughout pregnancy from an average of 6.5 % at the 12th week to 14.3 % at the 35th week of gestation. Two months after delivery the absorption was higher than initially. In the iron-treated group the absorption increased between the 24th and 35th week of gestation from 6.0 to 8.6 %. After delivery 5.5 % of the test dose was absorbed. The haemosiderin iron in the bone-marrow was mobilized during pregnancy. In the placebo group no woman had more than trace of haemosiderin in the bone-marrow smears at the 35th week of gestation. In the iron-treated group 65 % had the same bone-marrow findings. The amount of bone-marrow haemosiderin at term seems not to have the same significance for the diagnosis of iron deficiency in pregnancy as in non-pregnant subjects. Two months after delivery about 50 % of the women in the placebo group had restored their iron deposits. In the iron-group the haemosiderin content in the bone-marrow smears was enhanced in most women compared to early pregnancy. In the placebo group haematological data indicated a high frequency of iron deficiency in late pregnancy while in the iron-treated group iron deficiency was prevented.

Food iron absorption in man. Applications of the two-pool extrinsic tag method to measure heme and nonheme iron absorption from the whole diet

A new radioisotope method to measure iron absorption from the whole diet was used in this study. The method is based on the concept that food iron is absorbed from two pools, the heme iron pool and the nonheme iron pool, which can be especially labeled with two radioiron isotopes given as hemoglobin and as an iron salt. The purpose of this study was to test the accuracy of this two-pool extrinsic tag method. The meals served were composed as an average of 6 wk consumption in the present material of 32 young enlisted men. The mean and total heme and nonheme iron absorption in all the 32 young men was 1.01+/-0.11. This figure agrees well with the mean daily losses expected for this group of subjects (1.0 mg). The conclusion can therefore be made that there are no major systematic errors of the present method to measure the total iron absorption from a mixed diet. In one series a comparison was made of the absorption of heme and nonheme iron from the meals. A significant correlation between the absorption of the two kinds of iron was found. However, a much greater fraction of the heme iron was absorbed (37%) than of the nonheme iron (5%). The absorption both from breakfast and lunch was in two series found to give a good prediction of the total daily nonheme iron absorption. One series was designed to compare the effect of two levels of iron fortification. There was a significant increase in iron absorption when the level of iron fortification of the meals was increased.