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Biomedical subjects

J Dahlgren

Publications and source records attributed to J Dahlgren.

14 recordsLinked to original sources

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↗

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↗

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↗

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↗

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↗

In vitro activity of lomefloxacin (SC 47111 or NY-198), a new quinolone antimicrobial, against clinical isolates of common pathogens.

The lomefloxacin antibacterial activity was assessed against 442 clinical isolates of common bacterial pathogens and compared to the previously studied activity of ciprofloxacin, imipenem, norfloxacin, and other commonly used antibacterials. Lomefloxacin showed activity against the species of Enterobacteriaceae tested at a concentration equal to or below that of the most commonly used agents. Activity was lower against Pseudomonas species as well as most Gram-positive isolates tested with the exception of Staphylococcus aureus. Streptococcal strains were least susceptible. The results of this study support previous reports of excellent antimicrobial activity for lomefloxacin, especially against Gram-negative organisms.

4-Quinolones↗

Abdominal pain in lead workers.

Thirty-four lead smelter workers with excessive lead absorption were evaluated and followed. Abdominal pain was present in 27 patients. Fifteen patients who had left the site of lead exposure experienced persisting abdominal pain for as long as 29 months; some of these demonstrated acceptable levels of lead in blood. There is no correlation between lead levels and persisting pain. Twenty-three patients developed abdominal pain with blood lead lower than 80 microgram/100 ml while working. Four out of 15 patients with persisting abdominal pain had blood lead between 40 and 60 microgram/100 ml while working. Typical lead-induced abdominal pain is a sensitive symptom of intoxication and may be a criterion for removal from exposure regardless of blood lead levels.

Abdomen↗

Red-wine polyphenols and inhibition of platelet aggregation: possible mechanisms, and potential use in health promotion and disease prevention.

An extract from red-wine grape fermentation, ANOX has been developed as a source of red-wine polyphenols, which are thought to inhibit several of the pathogenic pathways that lead to cardiovascular disease. New data indicate that this extract has a significantly greater effect than either red wine or red-wine powder on the inhibition of platelet aggregation in vitro. Based on this data, about 300 - 500 mg of the extract is equivalent to the daily dose of red-wine polyphenols that appears to protect against cardiovascular disease. The possible synergistic effect of red-wine polyphenols with vitamin C, their vasorelaxing activity and their possible role in preventing over-crosslinking of connective tissues (premature ageing) are considered. The extract contains standardized amounts of the whole spectrum of polyphenolic compounds found in red wine and may provide a valuable reference substance in clinical investigations of the physiological actions of plant polyphenols; its potential use in functional nutrition and preventive medicine is also discussed.

Animals↗