Biomedical subjects

J Dahlgren

Publications and source records attributed to J Dahlgren.

At least 19 recordsLinked to original sources

PubMed2003

Craniofacial morphology and dental age in children with Silver-Russell syndrome.

OBJECTIVES: This investigation is a part of a multidisciplinary descriptive evaluation of the Silver-Russell syndrome (SRS). The aim of this study was to describe the craniofacial morphology, occlusion and dental age in children with the SRS. DESIGN: A descriptive literature-controlled study. SETTING AND SAMPLE POPULATION: Sixteen children diagnosed as having SRS, 10 boys and six girls, aged 4.4-14.5 years, were referred from different parts of Sweden to the Queen Silvia Children's Hospital, Göteborg University. EXPERIMENTAL VARIABLE: Facial morphology was measured on lateral and postero-anterior radiographs. Occlusion, tooth eruption and palatal height were measured on casts, and dental maturity was evaluated on orthopantomograms. OUTCOME MEASURE: Linear and angular measurements were obtained from lateral radiographs and the ratios of the linear measurements from the postero-anterior radiographs. The degree of tooth calcification shown on orthopantomograms was taken as a measure of dental maturity. Biometric measurements were taken and the degree of tooth eruption was recorded from the dental casts. The SRS children were compared with reference groups with t-test and z-scores. RESULTS: Overall, SRS children were found to have smaller linear facial dimensions and deviations in the facial proportions, such as a small retropositioned, and steeply inclined maxilla and mandible, and a proportionally larger anterior facial height in relation to the posterior facial height. In 40% of them a smaller facial height or length on one side (facial asymmetry) was correlated to the smaller side of the body. The frequency of malocclusions was higher, and the palatal height showed a tendency towards an increase. Dental maturity was within normal limits, while the time of tooth eruption was slightly delayed. CONCLUSIONS: The deviating facial morphology described above is a part of the syndrome, which is characterized by short stature, growth hormone deficiency and asymmetries of the body. The higher percentage of malocclusions in the SRS children might lead to a greater need of orthodontic treatment.

Abnormalities, Multiple↗

PubMed2002

Born small for gestational age: relation to future allergy and asthma.

AIM: To evaluate whether intrauterine growth retardation (IUGR) protects against the development of allergy. METHODS: A case-control study of 1515 subjects (15-25 y), of whom 430 were cases (birthweight/length below -2 SD for gestational age). Birth data were from the national birth register. The frequencies of allergic diseases were evaluated by questionnaire. RESULTS: For the 950 who replied, the frequencies of allergic diseases were similar in cases and controls. CONCLUSION: IUGR does not protect against the development of allergy.

Adolescent↗

PubMed2002

Affected skeletal growth but normal bone mineralization in rat offspring after prenatal dexamethasone exposure.

Events occurring early in life or prenatally are able to play important roles in the pathogenesis of diseases in adult life. Different sorts of stress or hormonal influences, during particular periods of pregnancy, may result in persisting or transient changes in physiology. Glucocorticoids are used for the treatment of a variety of diseases, to promote organ maturation and to prevent preterm delivery. Glucocorticoids are also known to affect skeletal growth and adult bone metabolism. The aim of the present study was to investigate whether exposure to dexamethasone (Dex) during fetal life has any effect on skeletal growth and/or bone mineral density in adult rat offspring. Pregnant rats were given injections of either Dex (100 micro g/kg) or vehicle on days 9, 11 and 13 of gestation. Dex-exposed male but not female rat offspring showed transient increases in crown-rump length and tibia and femur lengths at 3-6 weeks of age. In contrast, the cortical bone dimensions were altered in 12-week-old female but not male Dex-exposed offspring. The areal bone mineral densities of the long bones and the spine, as determined by dual X-ray absorptiometry, and trabecular as well as cortical volumetric bone mineral density, as measured using peripheral quantitative computerized tomography, were unchanged in both male and female Dex-exposed offspring. In conclusion, prenatal Dex exposure affects skeletal growth in a gender-specific manner, while the mineralization of bones is unaffected in both male and female offspring.

Absorptiometry, Photon↗

PubMed2001

Prenatal cytokine exposure results in obesity and gender-specific programming.

Prenatal events appear to program hormonal homeostasis, contributing to the development of somatic disorders at an adult age. The aim of this study was to examine whether maternal exposure to cytokines or to dexamethasone (Dxm) would be followed by hormonal consequences in the offspring at adult age. Pregnant rats were injected on days 8, 10, and 12 of gestation with either human interleukin-6 (IL-6) or tumor necrosis factor-alpha (TNF-alpha) or with Dxm. Control dams were injected with vehicle. All exposed offspring developed increased body weight (P < 0.05--0.001), apparently due to an increase of 30--40% in adipose tissue weight (P < 0.05--0.01). Corticosterone response to stress was increased in the IL-6 group (P < 0.05-0.01). Dxm-treated male rats exhibited blunted Dexamethasone suppression test results. In male rats, insulin sensitivity was decreased after IL-6 exposure (P < 0.01), whereas basal insulin was elevated in the TNF-alpha group (P < 0.01). In female rats, plasma testosterone levels were higher in all exposed groups compared with controls (P < 0.01--0.001), with the exception of Dxm-exposed offspring. Males in the TNF-alpha group showed decreased locomotor activity (P < 0.05), and females in the IL-6 group showed increased locomotor activity (P < 0.05). These results indicate that prenatal exposure to cytokines or Dxm leads to increased fat depots in both genders. In females, cytokine exposure was followed by a state of hyperandrogenicity. The results suggest that prenatal exposure to cytokines or Dxm can induce gender-specific programming of neuroendocrine regulation with consequences in adult life.

Adipose Tissue↗

PubMed2001

Leptin levels show diurnal variation throughout puberty in healthy children, and follow a gender-specific pattern.

OBJECTIVE: To investigate the levels and diurnal rhythm of serum leptin in healthy children, and to investigate the association between leptin levels and sex steroids. METHODS: Four girls and four boys, all healthy volunteers, were followed longitudinally throughout puberty. Their chronological ages ranged from 8.7 to 19.5 years, and body composition, expressed as weight-for-height standard deviation scores (SDS), ranged between -1.7 and +2.4. Serum leptin, oestradiol and testosterone concentrations were measured by radioimmunoassay at 1000, 1400, 1800, 2200, 0200 and 0600 h. RESULTS: In all girls and boys, both prepubertally and during pubertal development, serum leptin levels increased during the night, with no difference in relative peak amplitude. In boys, the leptin concentrations increased until the initiation of puberty and then declined, whereas in girls, the concentrations increased throughout puberty. The inter-individual variation in mean leptin levels among girls decreased to 11% at the time of menarche. A positive correlation was found for both oestradiol and testosterone versus leptin in girls throughout puberty (r=0.64 and r=0.71 respectively, P<0.001). A negative correlation was found between leptin and testosterone in boys in mid- and late puberty (r=-0.66, P<0.01). No correlation was found between oestradiol and leptin in boys or between testosterone and leptin in pre- and early pubertal boys. CONCLUSION: Serum leptin concentrations show diurnal variation throughout pubertal development in both girls and boys. The changes in leptin levels during puberty follow a gender-specific pattern, probably due to an influence of sex steroids on leptin production.

Adolescent↗

PubMed1998

Adrenal steroid hormones in short children born small for gestational age.

OBJECTIVE: Programming of the endocrine axis has been postulated to occur during critical phases of fetal development and is affected by intrauterine growth retardation. The aim of this study was to investigate this hypothesis with regard to adrenal steroid hormones. Thus, serum cortisol and dehydroepiandrosterone sulphate (DHEAS) levels were compared in children born small for gestational age (SGA) who remained short and in children born at an appropriate size for gestational age (AGA), of both short and normal stature. DESIGN AND PATIENTS: Seven serum samples for cortisol measurements were taken during a 24-h period from a total of 184 prepubertal individuals. The study group comprised 53 children born SGA who remained short (41 boys, 12 girls; mean chronological age, 8.8 +/- 2.5 years). The reference groups of children born AGA were as follows: 75 healthy short children (56 boys, 19 girls; mean chronological age, 10.8 +/- 2.6 years) and 56 healthy children of normal height (37 boys, 19 girls; mean chronological age, 11.3 +/- 1.8 years). A single serum sample for measurement of DHEAS was taken between 1000 and 1400 h in 110 of the 184 children (33 short SGA, 42 short AGA and 35 AGA of normal height). MEASUREMENTS: Serum cortisol and DHEAS were measured by radioimmunoassay. RESULTS: No differences were found between children born SGA and children born AGA in either cortisol levels, calculated as area under the curve (AUC), or the circadian cortisol rhythm, estimated from the calculated nadir, the peak and the amplitude. No difference between the groups was found for serum DHEAS concentrations. Serum cortisol levels, expressed as AUC, and serum DHEAS levels did not correlate with size at birth. However, when adjusted for age at investigation, serum DHEAS, but not serum cortisol, correlated with weight at birth. CONCLUSIONS: Serum cortisol levels and rhythms do not correlate with size at birth and are similar in children born small for gestational age who remain short and children born appropriate size for gestational age of both short and normal stature. However, DHEAS levels in young children before adrenarche correlated inversely with weight at birth, indicating a relationship with fetal growth.

Adolescent↗

PubMed1998

Radiographic and spirometric findings in diatomaceous earth workers.

Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5% had ILO scores > or = 1/0, and 25% had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.

Adult↗

PubMed1997

Circadian cortisol rhythms in healthy boys and girls: relationship with age, growth, body composition, and pubertal development.

To provide basic information on the normal functioning of the hypothalamus-pituitary-adrenal axis in relation to pubertal development, growth (weight and height), body composition, and gender and to obtain reference data for serum cortisol concentrations in children, we investigated the basal circadian rhythm of serum cortisol in a group of 235 healthy children (162 boys and 73 girls). The age range was between 2.2-18.5 yr. Serum cortisol was analyzed from venous blood samples taken at 1400, 1800, 2200, 0200, 0400, 0600, and 1000 h. No evidence was found for differences in temporal placement or level of the circadian cortisol rhythm in relation to age, growth, or body composition. However, we found a broad range of cortisol levels in a healthy population, with individual mean diurnal levels ranging from 100-510 nmol/L. Regardless of high or low mean diurnal cortisol levels, repeated measurements within and between pubertal stages indicated that an individual remains in his or her cortisol range throughout pubertal development. In conclusion, the present study shows that 1) serum cortisol levels do not correlate with either age or gender; 2) there is a large and significant interindividual variability in endogenous mean diurnal cortisol levels; and 3) despite this variability between individuals, there is no correlation between cortisol levels and either body composition or growth rate. This suggests that the variability in cortisol levels is an expression of normal homeostasis rather than pathology.

Adolescent↗

PubMed1997

Leptin levels are strongly correlated with those of GH-binding protein in prepubertal children.

OBJECTIVE: Nutritional status is an important determinant of growth, and previous studies have indicated that this is due, at least in part, to an increased target-tissue sensitivity to GH. An attractive candidate for mediating this effect is leptin, a hormone secreted by the adipose tissue. The aim of this study was to investigate if there was a connection between GH-binding protein (GHBP) and leptin. DESIGN AND METHODS: We investigated the relationship between serum levels of leptin and those of GHBP in 229 prepubertal children. These included 107 healthy children with normal GH secretion, 55 GH-deficient (GHD) children and 55 children born small for gestational age (SGA) sampled on one occasion for GHBP and leptin, and 12 healthy children followed longitudinally at monthly interval for 1 year. RESULTS: In the healthy children and in those born SGA, the serum concentration of GHBP was positively correlated with that of leptin (r = 0.65, P < 0.001; r = 0.74, P < 0.001 respectively). There was no correlation between GHBP and leptin in the group of children with GHD (r = 0.27, not significant). This means that leptin alone explained 42% of the variation of GHBP in the healthy group and 55% in the SGA group. The correlation remained after adjustment for body mass index and age in the healthy children (r = 0.57, P < 0.0001, r2 = 0.33) and for children born SGA (r = 0.74, P < 0.0001, r2 = 0.55). There was a positive correlation between the intra-individual monthly changes in GHBP and changes in leptin respectively, in the 12 healthy children followed longitudinally, the mean of the correlation coefficients was 0.38 (median = 0.29; range 0.03 to 0.86; P < 0.05). CONCLUSIONS: There was a highly significant correlation between serum levels of leptin and those of GHBP, except in children with GHD. The possibility that leptin could mediate the effects of body fat mass on GH sensitivity, therefore, merits further investigation.

Adolescent↗

PubMed1997

Serum leptin in short children born small for gestational age: relationship with the growth response to growth hormone treatment. The Swedish Study Group for Growth Hormone Treatment.

The product of the obese (ob) gene, leptin, is an adipocyte-derived hormone that is involved in the regulation of appetite and body weight. This study was undertaken in order to describe the basal serum levels of leptin in prepubertal short children born small for gestational age (SGA) and their relationship with growth parameters, before and during growth hormone (GH) treatment. Eighty-nine prepubertal short children (66 boys, 23 girls; height standard deviation score (SDS), -5.4 to -2.0; age, 2.0 to 12.8 years) born SGA, 12 of whom (9 boys, 3 girls) had signs of Silver-Russell syndrome, were included in the study. Serum leptin concentrations were measured by radioimmunoassay. Leptin levels in the children born SGA were compared with those in a reference group of 109 prepubertal healthy children born at an appropriate size for gestational age (AGA). The mean (S.D.) change in height SDS was 0.11 (0.22) during the year before the start of GH therapy (0.1 IU/kg/day) and increased to 0.82 (0.44) during the first year (P < 0.001) and to 1.28 (0.59) during the 2-year period of GH therapy (P < 0.001). The children born SGA were significantly leaner than the reference group. An inverse correlation was found between leptin and chronological age in the SGA group (r = -0.31, P < 0.01). The mean serum level of leptin in the children born SGA who were older than 5.5 years of age was 2.8 micrograms/l which was significantly lower than the mean value of 3.7 micrograms/l found in the children born AGA of the same age range. The difference remained after adjustment of leptin levels for sex, age, body mass index (BMI) and weight-for-height SDS (WHSDSSDS). Leptin correlated with WHSDSSDS (r = 0.32, P < 0.001) and BMI (r = 0.36, P < 0.01) in the reference population, but not in the SGA group. No correlation was found between leptin and spontaneous 24-h GH secretion, insulin-like growth factor (IGF)-I or IGF-binding protein-3 levels, or with fasting insulin or cortisol levels. Leptin levels at the start of GH treatment were correlated with the growth response over both 1 year (r = 0.46, P < 0.001) and 2 years (r = 0.51, P < 0.001) of GH therapy. Using multiple regression analysis, models including leptin levels at the start of GH therapy could explain 51% of the variance in the growth response after 1 year and 44% after 2 years of GH treatment. In conclusion, serum leptin levels are reduced in short children born SGA and are inversely correlated with chronological age. Leptin concentrations correlate with the growth response to GH treatment and might be used as a marker for predicting the growth response to GH treatment.

Aging↗

PubMed1988

Variation in diet composition: a hazard to the reliability of the LD50-test.

The severity of toxic effects on nearly fully-grown birds from an organophosphorus insecticide (isofenphos) was shown to be affected by the tested birds' previous diet as juveniles. Subadult grey partridges (Perdix perdix), with an insect-poor diet as juveniles, were severely affected by the insecticide, whereas birds fed an insect-rich diet as juveniles showed no signs of poisoning after feeding on isofenphos-treated seeds.

Journal Article↗

PubMed1978