Cystatin C, β-2-microglobulin and β-trace protein in pre-eclampsia

BACKGROUND

An altered renal function is an essential component of the patho-physiology of pre-eclampsia. The plasma levels of low molecular mass proteins, e.g. beta-trace protein, beta-2-microglobulin and cystatin C, are increased in the third trimester of normal pregnancy. The plasma levels of cystatin C and beta-2-microglobulin are further increased in pre-eclampsia, and the cystatin C level has been reported to be a reliable marker for the disease. The aim of this investigation was to study the plasma levels of beta-trace protein, beta-2-microglobulin and cystatin C in pre-eclampsia, and to determine the diagnostic performance of these proteins compared to that of urate and creatinine.

METHODS

A case-control study of 57 women diagnosed with pre-eclampsia, and 218 healthy women with uncomplicated singleton pregnancies in the third trimester. Women in the catchment area of Lund, Sweden, were included during an 18-month period from October 2003 to April 2005. Venous blood samples were drawn upon inclusion when diagnosis was made. The maternal plasma concentrations of the 3 proteins were analysed by automated particle-enhanced immunoturbidimetric assays.

RESULTS

The plasma levels of the 3 proteins were significantly higher in the third trimester of pre-eclamptic patients compared to healthy pregnant women in the third trimester. The upper reference limits (parametric 97.5 percentile) were 2.57 mg/l for beta-2-microglobulin, 0.72 mg/l for beta-trace protein and 1.37 mg/l for cystatin C. ROC analysis showed similar diagnostic performance for the 3 proteins, with beta-trace protein displaying the best diagnostic performance of all the analytes.

CONCLUSIONS

In this study, the maternal plasma levels of beta2-microglobulin, beta-trace protein and cystatin C were all significantly elevated in pre-eclampsia compared to those of healthy pregnant women, and displayed similar diagnostic performance for diagnosing pre-eclampsia. The results indicate that low molecular mass proteins are useful as markers of renal impairment in pre-eclampsia.

The metabolic syndrome is frequent in Klinefelter's syndrome and is associated with abdominal obesity and hypogonadism

OBJECTIVE

Klinefelter's syndrome is associated with an increased prevalence of diabetes, but the pathogenesis is unknown. Accordingly, the aim of this study was to investigate measures of insulin sensitivity, the metabolic syndrome, and sex hormones in patients with Klinefelter's syndrome and an age-matched control group. RESEARCH DESIGN AN METHODS: In a cross-sectional study, we examined 71 patients with Klinefelter's syndrome, of whom 35 received testosterone treatment, and 71 control subjects. Body composition was evaluated using dual-energy X-ray absorptiometry scans. Fasting blood samples were analyzed for sex hormones, plasma glucose, insulin, C-reactive protein (CRP), and adipocytokines. We analyzed differences between patients with untreated Klinefelter's syndrome and control subjects and subsequently analyzed differences between testosterone-treated and untreated Klinefelter's syndrome patients.

RESULTS

Of the patients with Klinefelter's syndrome, 44% had metabolic syndrome (according to National Cholesterol Education Program/Adult Treatment Panel III criteria) compared with 10% of control subjects. Insulin sensitivity (assessed by homeostasis model assessment 2 modeling), androgen, and HDL cholesterol levels were significantly decreased, whereas total fat mass and LDL cholesterol, triglyceride, CRP, leptin, and fructosamine levels were significantly increased in untreated Klinefelter's syndrome patients. In treated Klinefelter's syndrome patients, LDL cholesterol and adiponectin were significantly decreased, whereas no difference in body composition was found in comparison with untreated Klinefelter's syndrome patients. Multivariate analyses showed that truncal fat was the major determinant of metabolic syndrome and insulin sensitivity.

CONCLUSIONS

The prevalence of metabolic syndrome was greatly increased, whereas insulin sensitivity was decreased in Klinefelter's syndrome. Both correlated with truncal obesity. Hypogonadism in Klinefelter's syndrome may cause an unfavorable change in body composition, primarily through increased truncal fat and decreased muscle mass. Testosterone treatment in Klinefelter's syndrome only partly corrected the unfavorable changes observed in untreated Klinefelter's syndrome, perhaps due to insufficient testosterone doses.

[Severe diarrhea after the original well-functioning percutaneous endoscopic gastrostomy tube was replaced by a Mic-Key button]

We report two cases of colocutaneous fistula as a complication of percutaneous endoscopic gastrostomy (PEG) in small children. Both children developed severe osmotic diarrhoea immediately after the original PEG tube was replaced by a Mic-Key button which subsequently migrated to the colon.

Further delineation of the 22q13 deletion syndrome

A chromosomal deletion syndrome associated with a 22q13 microdeletion has previously been reported in approximately 75 children. We report six cases from Denmark with a deletion of 22q13. One was cytogenetically visible by conventional karyotyping, one was diagnosed by high resolution karyotyping after the demonstration of low arylsulfatase A activity. Two were diagnosed by high resolution CGH analysis, one was diagnosed by multisubtelomeric FISH analysis and one was diagnosed serendipitously as lack of the control signal in a FISH analysis for 22q11 deletion. One of the cases was a mosaic with 16% of cells showing two signals. The phenotype of the children included: generalized developmental delay, compromised language development, hypotonia, normal or accelerated growth and minor facial dysmorphism. Other features were partial agenesis of the corpus callosum, bilateral ureteropelvic stricture, gastroesophageal reflux and hearing loss. One case had a different phenotype, and showed a deletion as well as a duplication. The extent of the deletion was studied by quantitative PCR analysis of a number of DNA markers in the 22q13 region. The deletions varied in size, extending from 4.0 to 9.0 Mb. The clinical phenotype seemed rather similar although some specific features might be attributable to differences in deletions.

Increased adiposity and reduced adipose tissue mRNA expression of uncoupling protein-2 in first-degree relatives of type 2 diabetic patients: evidence for insulin stimulation of UCP-2 and UCP-3 gene expression in adipose tissue

The mitochondrial uncoupling proteins (UCP-2 and UCP-3), which have been suggested to be involved in the development of obesity by controlling the energy expenditure (EE), were studied in 22 healthy first-degree relatives (FDRs) of patients with type 2 diabetes and 13 body mass index (BMI)- and age-matched healthy control subjects. Abdominal subcutaneous adipose tissue biopsies were obtained before and after 150-min hyperinsulinaemic clamp (average serum insulin 250 pM). Basal adipose tissue UCP-2 mRNA levels in the FDR group were significantly lower than that in the control group. After the hyperinsulinaemic clamp, adipose tissue UCP-2 mRNA levels were increased by 32% in the control group (p < 0.05) and 32% in the FDR group (p < 0.05). The basal adipose tissue UCP-3 mRNA level was similar in the two groups and increased in both the groups during hyperinsulinaemia (p < 0.001). Dual energy X-ray absorptiometry showed that despite similar BMI the FDR group had significantly higher fat mass (FM) per cent compared to that of the control group (p < 0.01). The UCP-2 mRNA expression was inversely correlated with the amount of adipose tissue (r = -0.53, p < 0.001), and multiple regression analysis revealed that only the amount of FM was independently correlated with basal UCP-2 mRNA levels, whereas age, gender nor family history of type 2 diabetes contributed independently to the variation in UCP-2 mRNA levels. No differences in EE were observed between the two groups, and no association between EE and UCP mRNA expression was found. In conclusion, we have demonstrated that adipose tissue UCP-2 and UCP-3 mRNA levels are significantly increased during a 150-min hyperinsulinaemic clamp. The UCP-2 mRNA levels were expressed at a significantly lower level FDR to type 2 diabetes compared to control subjects. However, in multiple regression analysis controlling for amount of adipose tissue, the difference between the two groups disappeared. Thus, only the amount of adipose tissue contributed independently to the variation in UCP-2 mRNA expression.

Gene expression of the GH receptor in subcutaneous and intraabdominal fat in healthy females: relationship to GH-binding protein

OBJECTIVE

Circulating GH-binding protein (GHBP) is produced by proteolytical cleavage of the extracellular part of the GH receptor (GHR) and is positively correlated to the amount of body fat. To test the hypothesis that adipose tissue may contribute to the production of circulating GHBP, we compared gene expression of two GHR isoforms in adipose tissue with serum GHBP concentrations in healthy females.

DESIGN

Twenty-two healthy females undergoing surgery for benign gynecological conditions were included in the study.

METHODS

During surgery, s.c. and intraabdominal fat biopsy samples were taken. Gene expression of the full-length GHR and a truncated GHR (GHRtr) was assessed by RT-PCR relative to the expression of beta-actin.

RESULTS

The full-length GHR was expressed to a much higher level than GHRtr in both tissues. The levels of both GHR and GHRtr mRNA were similar in intraabdominal and s.c. adipose tissues. Surprisingly, concentrations of circulating GHBP were negatively correlated to the levels of mRNA transcripts of both the full-length GHR and GHRtr in intraabdominal fat. Whole body resistance (as a measure of lean body mass) was positively correlated to mRNA levels for both GHRs in intraabdominal fat.

CONCLUSIONS

(i) The full-length GHR is expressed to a much higher level than GHRtr in s.c. as well as visceral abdominal fat; (ii) the observation of a significant correlation between GHR expression and GHBP levels further emphasizes the link between adipose tissue and GHBP; (iii) it remains, however, to be demonstrated whether circulating GHBP is produced to a significant degree by adipose tissue.

Reduced bone mineral density and increased bone turnover in Prader-Willi syndrome compared with controls matched for sex and body mass index--a cross-sectional study

OBJECTIVES

To study bone mineral status, body composition, and biochemical markers of bone turnover in Prader-Willi syndrome (PWS).

STUDY DESIGN

Eight subjects with PWS (three males, five females; mean age, 24 years [range 16-41]) were included. Each subject was compared with an age-, sex- and body mass index-matched control randomly drawn from the background population. Bone mineral density (BMD), lean body mass, and fat mass were measured. Plasma PINP, PIIINP, osteocalcin, total alkaline phosphatase, bone-specific alkaline phosphatase, C-terminal telopeptide of type I collagen, and urine cross-linked N-terminal telopeptide of type I collagen were measured as biochemical markers of bone and collagen turnover.

RESULTS

The PWS patients had significantly lower whole-body BMD (mean +/- SD, 1.020 +/- 0.041 vs 1.237 +/- 0.118 g/cm(2); 2p <.01) than controls due to lower bone mineral content (BMC: 2291 +/- 607 vs 2825 +/- 409 g; 2p=.02). Resorptive and formative bone markers were significantly elevated in patients compared with controls. Plasma testosterone was low in male patients (3.50 +/- 4.97 vs 19.2 +/- 8.78 nmol/L, 2p=.05), whereas no difference in plasma estradiol was present.

CONCLUSIONS

The patients had a low BMD due to a high bone turnover. This high turnover was probably linked to sex steroid deficiency.

Estrogen controls lipolysis by up-regulating alpha2A-adrenergic receptors directly in human adipose tissue through the estrogen receptor alpha. Implications for the female fat distribution

Estrogen seems to promote and maintain the typical female type of fat distribution that is characterized by accumulation of adipose tissue, especially in the sc fat depot, with only modest accumulation of adipose tissue intraabdominally. However, it is completely unknown how estrogen controls the fat accumulation. We studied the effects of estradiol in vivo and in vitro on human adipose tissue metabolism and found that estradiol directly increases the number of antilipolytic alpha2A-adrenergic receptors in sc adipocytes. The increased number of alpha2A-adrenergic receptors caused an attenuated lipolytic response of epinephrine in sc adipocytes; in contrast, no effect of estrogen on alpha2A-adrenergic receptor mRNA expression was observed in adipocytes from the intraabdominal fat depot. These findings show that estrogen lowers the lipolytic response in sc fat depot by increasing the number of antilipolytic alpha2A-adrenergic receptors, whereas estrogen seems not to affect lipolysis in adipocytes from the intraabdominal fat depot. Using estrogen receptor subtype-specific ligands, we found that this effect of estrogen was caused through the estrogen receptor subtype alpha. These findings demonstrate that estrogen attenuates the lipolytic response through up-regulation of the number of antilipolytic alpha2A-adrenergic receptors only in sc and not in visceral fat depots. Thus, our findings offer an explanation how estrogen maintains the typical female sc fat distribution because estrogen seems to inhibit lipolysis only in sc depots and thereby shifts the assimilation of fat from intraabdominal depots to sc depots.

Evidence of increased visceral obesity and reduced physical fitness in healthy insulin-resistant first-degree relatives of type 2 diabetic patients

OBJECTIVE

First-degree relatives (FDR) of type 2 diabetic patients are often insulin resistant. Visceral obesity is closely linked to both insulin resistance and type 2 diabetes. We therefore hypothesized that the inheritance of an increased tendency to store fat in visceral fat depots may be a characteristic phenotypic feature in FDR contributing to their insulin resistance.

DESIGN AND METHODS

We measured fat distribution in 20 FDR and 14 age-, gender- and body mass index (BMI)-matched controls employing dual energy X-ray absorbtiometry (DEXA)- and computed tomography (CT)-scanning. Insulin-stimulated glucose uptake (ISGU) was determined by a hyperinsulinemic clamp and maximal aerobic work capacity (VO2 max) by a bicycle ergometer test. Baseline lipolysis was measured using [3H]palmitate. The activity level of the hypothalamic-pituitary-adrenal axis was assessed as the 24 h urinary (u)-cortisol/creatinine ratio.

RESULTS

All subjects had a normal oral glucose tolerance test (OGTT), but FDR were insulin resistant (ISGU: 6.64+/-0.48 vs 9.12+/-0.98 mg/kg ffm/min, P=0.01). Despite similar BMI (25.2+/-0.5 vs 24.8+/-0.7 kg/m2, P=0.61) and overall fat mass (26.4+/-1.6 vs 24.2+/-2.1%, P=0.41) in FDR vs controls, the amount of visceral adipose tissue was substantially increased (65.9+/-10.0 vs 40.1+/-11.3 cm2, P<0.05) and VO2 max was reduced (52.2+/-3.1 vs 63.3+/-3.9 ml/kg ffm/min, P<0.05) in FDR. Visceral adiposity was inversely correlated with ISGU (FDR: r=-0.52, P<0.05; controls: r=-0.65, P<0.01) and in multiple regression analysis visceral adiposity (P<0.01), VO2 max (P<0.001) and a family history of type 2 diabetes (P<0.05) (r2=0.64) all significantly and independently contributed to the level of ISGU. Baseline palmitate appearance (145+/-10 vs 139+/-15 micromol/min, P=0.74) and the 24 h u-cortisol/creatinine ratio ((24.9+/-1.3 vs 27.4+/-2.0).10(-6), P=0.28) were both comparable in the two groups.

CONCLUSION

Healthy but insulin-resistant FDR have enhanced visceral obesity and reduced VO2 max compared with people without a family history of diabetes, despite similar BMI and overall fat mass. Both the visceral adiposity and reduced aerobic fitness are strongly associated with and may contribute to their insulin resistance.

Anti-glucocorticoid effects of progesterone in vivo on rat adipose tissue metabolism

Steroid hormones seem to be important for adipose tissue metabolism and accumulation. As progesterone has been suggested to modulate the glucocorticoid effects, the interactions between glucocortioid and progesterone on adipose tissue metabolism were investigated.Forty-eight male Wistar rats were adrenectomized and divided into four groups; controls (treated with vehicle only), dexamethasone treated (10 micro g per rat), progesterone treated (5mg per rat) and the last group received both dexamethasone and progesterone. The dexamethasone-treated group had a significant loss of body weight and smaller intra-abdominal fat depots compared to the control group in addition, dexamethasone increased LPL-activity and increased catecholamine stimulated lipolysis. When progesterone was given concomitantly the dexamethasone effects on adipose tissue mass, LPL-activity and lipolysis were blocked. When given alone progesterone had no influence on body weight, amount of adipose tissue, lipolysis or LPL-activity. These data indicate that progesterone acts as an anti-glucocorticoid in adipose tissue in vivo, thus attenuating the glucocorticoid effect on adipose tissue metabolism.

Rehospitalization for respiratory syncytial virus infection in infants with extremely low gestational age or birthweight in Denmark

AIM

To determine the risk of rehospitalization for respiratory syncytial virus (RSV) infection during the first 2 y of life in extremely preterm infants.

METHODS

Records on all rehospitalizations during the first 2 living years of all infants born with gestational age <28 wk or birthweight <1,000g during 1994 and 1995 in Denmark were retrospectively reviewed.

RESULTS

Among 240 eligible infants, 43 (18%) had been rehospitalized 48 times owing to RSV. In infants (n = 210) without CLD the risk of rehospitalization for RSV was 16%, whereas in infants with CLD (n = 30) it was 30% (p = 0.065). Eighteen infants (38%) required respiratory support (supplemental oxygen only 3, continuous positive airway pressure 14, mechanical ventilation 1). Apart from CLD the only factor that could be associated with increased risk of hospitalization for RSV was discharge during autumn (p = 0.05). No infant died from RSV infection.

CONCLUSION

The high rate of rehospitalization for RSV in extremely preterm infants in Denmark, especially in infants with CLD, should lead to considerations concerning more widespread use of prophylaxis against RSV in these infants.

Impact of dietary FA and energy restriction on plasma leptin and ob gene expression in mice

The aim of the present study was to elucidate whether the qualitative composition of dietary fat influences plasma leptin and adipose tissue ob gene expression differentially. Two high-fat diets and a diet rich in carbohydrate were each administered both ad libitum and with a 25% energy restriction. The high-fat diets contained 58 energy percent as either monounsaturated FA (MUFA) or saturated FA (SAFA), whereas the carbohydrate-rich diet (CH) contained 7 energy percent as fat. We aimed at obtaining the same final weight for the animals in the ad libitum group as in the energy-restricted groups. This goal was reached at the same time (days 22-24) for all groups except for the ad libitum animals fed on saturated fat (day 36). The plasma leptin concentrations on ad libitum CH and MUFA diets did not differ significantly (24.3 +/- 2.1 and 34.7 +/- 6.7 ng/mL, respectively) whereas the saturated fat diet caused a lower concentration (13.9 +/- 1.9 ng/mL; P < 0.05). Interestingly, no differences in plasma leptin levels between groups were seen in the energy-restricted groups (mean 8.0 +/- 1.0 ng/mL). The type of diet did not alter the ob gene expression in intraabdominal white adipose tissue; however, a lower expression level was found in the energy-restricted groups. The percentage of body fat in the three ad libitum fed groups did not differ (23 +/- 1%). Thus, short-term administration of a diet rich in SAFA suppresses circulating leptin levels without altering the adipose tissue ob gene expression. This indicates that saturated fat may alter protein handling by adipose tissue or the whole body clearance of leptin.

Opposite regulation of interleukin-8 and tumor necrosis factor-alpha by weight loss

OBJECTIVE

To obtain more information on the possible influence of body mass index (BMI) and weight loss on interleukin-8 (IL-8) in plasma and in the adipose tissue. Tumor necrosis factor-alpha (TNF-alpha) was used for comparison and determined in parallel with IL-8.

RESEARCH METHODS AND PROCEDURES

The study was divided into three parts: 1) a cross-sectional study that included 89 subjects; 2) a 20-week intervention study in which 34 healthy obese subjects received a dietary intervention for 8 weeks followed by an additional 12 weeks on a weight-stabilization diet; 3) from this latter study, a subgroup of 8 obese subjects was investigated with a subcutaneous adipose-tissue biopsy.

RESULTS

In the cross-sectional study, plasma levels of TNF-alpha (p < 0.01), but not IL-8, was correlated with BMI. However, in a subgroup (BMI, 20 to 30 kg/m(2)), IL-8 was correlated with BMI (p < 0.01). In the intervention study, weight loss and weight maintenance led to an increase in IL-8 by 30% (p < 0.05) and a decrease in TNF-alpha by 40% (p < 0.001), which were paralleled in the adipose tissue, demonstrating a 2- to 3-fold increase (p < 0.01) and a 40% to 80% decrease (p < 0.01) in IL-8 and TNF-alpha, respectively.

DISCUSSION

Weight loss in obese subjects was associated with opposite changes in the secretion and transcription of IL-8 and TNF-alpha in the adipose tissue, as well as in plasma. This could indicate that plasma IL-8 under some conditions may be related to changes in adipose tissue IL-8 production.

Effects of pro-inflammatory cytokines and chemokines on leptin production in human adipose tissue in vitro

Leptin is synthesized in adipocytes and acts primarily through central pathways suppressing appetite and increasing the metabolic rate in rodents as well as in humans. Recently leptin has also been suggested to have peripheral effects and be involved in insulin action. Since cytokines and chemokines may have effects on appetite regulation as well as on some of the obesity-related complications e.g. insulin resistance and cardiovascular disease, we investigated the effects of various cytokines and chemokines on leptin production in human adipose tissue fragments in vitro. Abdominal subcutaneous adipose tissue from healthy normal to overweight females was incubated for up to 48 h with the cytokines: tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-1beta (IL-1beta) and the chemokine: interleukin-8 (IL-8). IL-1beta (50 ng/ml) and TNF-alpha (10 ng/ml) decreased leptin production by 30-50% (P<0.05) and gene expression by 80-90% (P<0.05). In contrast, IL-6 and IL-8 had no effect on either leptin production or leptin gene expression. Interestingly, IL-1beta elicited a biphasic effect on leptin release with an incremental phase observed within 4 h with no concomitant change in leptin gene expression, followed by a long-lasting inhibition of leptin release and leptin gene expression. This could suggest that IL-1beta through a post-translational pathway induced an acute increase in leptin-secretion, perhaps through the release of leptin from a pre-formed pool within the adipose tissue. The long-term decrease in both leptin secretion and transcription could indicate that pro-inflammatory cytokines such as IL-1beta and TNF-alpha might influence the circulating leptin levels and thereby influence the adipose tissue to brain signalling, which could be of importance in relation to the obesity-associated diseases such as insulin resistance and cardiovascular disease.

A P387L variant in protein tyrosine phosphatase-1B (PTP-1B) is associated with type 2 diabetes and impaired serine phosphorylation of PTP-1B in vitro

In the present study, we tested the hypothesis that variability in the protein tyrosine phosphatase-1B (PTP-1B) gene is associated with type 2 diabetes. Using single-strand conformational polymorphism analysis, we examined cDNA of PTP-1B from 56 insulin-resistant patients with type 2 diabetes as well as cDNA from 56 obese patients. Four silent variants, (NT CGA-->CGG) R199R, (NT CCC-->CCT) P303P, 3'UTR+104insG, and 3'UTR+86T-->G, and one missense variant, P387L, were found. Subsequent analysis on genomic DNA revealed two intron variants, IVS9+57C-->T and IVS9+58G-->A, and two missense variants, G381S and T420M. The G381S and 3'UTR+104insG insertion variants were not associated with type 2 diabetes. In an association study, the P387L variant was found in 14 of 527 type 2 diabetic subjects (allelic frequency 1.4%, 0.4-2.4 CI) and in 5 of 542 glucose-tolerant control subjects (allelic frequency 0.5%, CI 0.1-1.1), showing a significant association to type 2 diabetes (P = 0.036). In vitro, p34 cell division cycle (p34(cdc2)) kinase-directed incorporation of [gamma-(32)P]ATP was reduced in a mutant peptide compared with native peptide (387P: 100% vs. 387L: 28.4 +/- 5.8%; P = 0.0012). In summary, a rare P387L variant of the PTP-1B gene is associated with a 3.7 (CI 1.26-10.93, P = 0.02) genotype relative risk of type 2 diabetes in the examined population of Danish Caucasian subjects and results in impaired in vitro serine phosphorylation of the PTP-1B peptide.

Regulation of UCP1, UCP2, and UCP3 mRNA expression in brown adipose tissue, white adipose tissue, and skeletal muscle in rats by estrogen

The effects of ovariectomy (OVX) and estrogen substitution on body weight, body composition, food intake, weight gain, and expression of uncoupling proteins (UCPs) in brown adipose tissue (BAT), white adipose tissue (WAT), and skeletal muscle were studied in four groups of rats: (1) Sham-operated rats (N = 8), (2) ovariectomized rats (OVX - E) (N = 8), (3) estrogen-treated OVX rats (OVX + E) (N = 8), and (4) OVX rats on energy restriction (OVX - E + D) (N = 8). OVX was associated with an increase in food intake and body weight gain during a 5-week study period compared to sham-operated rats. The estrogen-substituted rats had a significantly lower food intake and weight gain during the 5 weeks compared to the sham-operated group. However, we also included a nontreated OVX group that was allowed to eat only enough chow to match the weight gain of the sham-operated group. To match the weight gain in the two groups, the OVX group had to consume 16% less chow than the sham-operated group. In BAT, the UCP1 expression was significantly lower in estrogen-deficient rats compared to either intact rats or estrogen-substituted rats, whereas UCP2 and UCP3 mRNA expression was similar in BAT from all four groups. In WAT, both estrogen-deficient groups had significantly lower UCP2 mRNA expression compared to the control rats and estrogen-treated rats; In contrast, the UCP3 mRNA expression in WAT was similar in all four groups. Finally, in skeletal muscle the OVX group on mild energy restriction had reduced UCP3 mRNA expression compared to control, OVX, and estrogen-treated rats. In contrast, the UCP2 mRNA expression in skeletal muscle was similar in all four groups. Thus, the findings that estrogen deficiency is followed by reduced UCP1 expression in BAT and reduced UCP2 expression in WAT in association with weight gain probably caused by a decrease in energy expenditure might indicate that UCPs play a role for the estrogen-mediated changes in body weight and energy expenditure.

Demonstration of estrogen receptor subtypes alpha and beta in human adipose tissue: influences of adipose cell differentiation and fat depot localization

A novel ER-subtype, the ER-beta has recently been characterized in various tissues, furthermore five isoforms of the ER-beta are known (ER-beta1--ER-beta5). Using immunoblotting and real- time RT-PCR, ER-alpha and beta were studied in human adipose tissue. The expression of ER-alpha mRNA was equal in subcutaneous gluteal adipose tissue, subcutaneous abdominal and intra-abdominal adipose tissue, similar findings were obtained at the protein level. In contrast the amount of ER-beta1 (protein and mRNA) was significantly lower in intra-abdominal adipose tissue as compared with the subcutaneous adipose tissue (five-fold lower in women, P<0.005 and three-fold lower in men, P<0.005) whereas the expression of ER-beta4 and -beta5 mRNA isoforms were significantly higher in gluteal adipose tissue compared to subcutaneous abdominal adipose tissue. No significant gender differences in ER expression was detected in any of the fat depots investigated. During adipocyte differentiation the expression of ER-alpha, -beta4 and -beta5 mRNA declined, whereas, the expression of ER-beta1 mRNA was constant. In conclusion, the existence of ER-beta isoforms in human adipose tissue was demonstrated and the amount of these receptors was dependent upon fat depot localization, with much reduced expression of ER-beta1 in intra-abdominal adipose tissue compared to subcutaneous adipose tissue. These findings may indicate that estrogens could have differentiation and depot specific effects in human adipose tissue.

Denitrification losses from outdoor piglet production: spatial and temporal variability

Animal welfare considerations have stimulated the development of outdoor piglet (Sus scrofa) production systems, but the high levels of nutrients excreted suggest that nutrient losses from this system may be high. This study first described the spatial distribution of denitrification activity in a 5- x 5-m grid within and outside a paddock immediately after the sows (32 sows ha(-1) for 6 mo) were removed in October 1997, and again the following March. Denitrification rates averaged 0.01 kg N ha(-1) d(-1) outside, and 0.5 kg N ha(-1) d(-1) inside the paddock in October, while the corresponding figures in March were 0.01 and 0.1 kg N ha(-1) d(-1). The highest denitrification rates were observed around the feeder, and this was also the case for concentrations of dissolved organic C and inorganic N in the soil. A statistical model that included both soil parameters and distance to feeder and huts gave the best description of the variability, but there was no significant autocorrelation between sampling points. In a second phase, seasonal variation of denitrification activity within a paddock (12 sows ha(-1) yr(-1)) was quantified; 10 soil cores were sampled along a transect 11 times between March 1998 and February 1999. There was a significant positive effect of dissolved organic carbon (DOC) on denitrification at <25% gravimetric soil moisture (i.e., to November in this study). Both climate and management (position of huts and feeder) appeared to influence denitrification, which was estimated to be 69 kg N ha(-1) yr(-1), or 11% of the N surplus of this production system.

Gene expression of a truncated and the full-length growth hormone (GH) receptor in subcutaneous fat and skeletal muscle in GH-deficient adults: impact of GH treatment

In humans at least two GH receptors are significantly expressed. One is the full-length receptor (GHR); the other is a truncated form (GHRtr), that lacks most of the intracellular domain. This receptor may inhibit the action of the full-length receptor. Circulating GH-binding protein (GHBP) is a proteolytically cleaved product from both of these receptors. The clinical relevance of the different receptor types is unknown. We examined the gene expression of GHR and GHRtr in human adipose tissue and skeletal muscle and the influence of GH treatment on this expression. Furthermore, we studied the relationship of circulating GHBP and body composition to GHR and GHRtr gene expression. Eleven adult GH-deficient patients were studied before and after 4 months of GH substitution therapy. Abdominal fat obtained by liposuction and femoral muscle biopsies were taken at baseline and after 4 months. Gene expression of GHR and GHRtr in adipose tissue and skeletal muscle was determined and expressed relative to the expression of beta-actin. Gene expression of GHR in abdominal sc adipose tissue was not altered, whereas the expression of GHRtr increased significantly. In skeletal muscle inverse changes were seen in the expression of messenger ribonucleic acid (mRNA) levels for the two GH receptor forms: expression of GHR increased significantly, whereas mRNA levels for GHRtr decreased. As expected, body composition changed with reduction of body fat mass after 4 months of GH treatment. Levels of circulating GHBP decreased significantly. We conclude that GH treatment in GH-deficient adults changes the expression of mRNA for GHR and GHRtr in adipose tissue and skeletal muscle. Whether these changes are responsible for the observed changes in body composition in response to GH treatment and the observed changes in levels of circulating GHBP, however, needs further elucidation.

Systemic administration of epidermal growth factor increases UCP3 mRNA levels in skeletal muscle and adipose tissue in rats

We have previously reported that systemic epidermal growth factor (EGF) treatment in rats reduces the amount of adipose tissue despite an unaltered food intake. The mitochondrial uncoupling proteins (UCP2 and UCP3) are thought to uncouple the respiratory chain and thus to increase energy expenditure. In order to find out whether the UCP system was involved in the EGF-induced weight loss, the effects of EGF on UCP2 and UCP3 in adipose tissue and skeletal muscle were investigated in the present study. Eight rats were treated with placebo or EGF (150 microg/kg/day) for seven days via mini-osmotic pumps. The EGF-treated rats gained significantly less body weight during the study period than the placebo-treated animals and had significantly less adipose tissue despite a similar food intake. The placebo group and the EGF group had similar UCP2 mRNA expression (in both adipose tissue and skeletal muscle), whereas the EGF-treated group compared to the placebo group had significantly higher UCP3 mRNA expression in both skeletal muscle (3.76 +/- 0.90 vs 8.41 +/- 0.87, P < 0.05) and in adipose tissue (6.38 +/- 0.71 vs 12.48 +/- 1.79, P < 0.05). In vitro studies with adipose tissue fragments indicated that the EGF effect probably is mediated indirectly as incubations with EGF (10 microM) were unable to affect adipose tissue UCP expression, whereas incubations with bromopalmitate stimulated both UCP2 and UCP3 mRNA expression twofold. Thus, EGF treatment in vivo was found to enhance UCP3 mRNA expression in both adipose tissue and skeletal muscle, which may indicate that the EGF effect on body composition might involve up-regulation of UCP3 in skeletal muscle and adipose tissue.

Interactions between sex steroid hormones and leptin in women. Studies in vivo and in vitro

OBJECTIVE

To investigate the associations between sex hormones and leptin. In addition, to investigate the direct effect of sex hormones by incubations of human subcutaneous adipose tissue explants, in vitro.

DESIGN

Cross-sectional study and an experimental in vitro study.

SUBJECTS

36 women (age, 23-65 y; body mass index, BMI, 19-65 kg/m2) participated in the cross-sectional study. Subcutaneous abdominal biopsies were taken from nine women (age, 28 - 46 y; BMI, 25.5-36.0 kg/m2) for the in vitro study.

MEASUREMENTS

Fat distribution parameters (by dual-energy X-ray absorptiometry and anthropometry), sex hormones, leptin and insulin.

RESULTS

Leptin correlated significantly with most estimates of adipose tissue mass (r= 0.5 - 0.9, P< 0.05). However, when the study group was divided in three equal groups (non-obese, obese, and very-obese) it revealed that the correlation predominantly was found in non-obese. In simple correlation analysis leptin was significantly associated with estimates of adipose tissue, insulin and several sex hormones. However, in multiple regression analysis only insulin (partial correlation coefficient = 0.55, P < 0.004) and percentage fat mass (partial correlation coefficient = 0.72, P<0.001) were significantly and independently correlated with leptin without any independent effect of sex hormones. These findings were in agreement with the in vitro studies where neither estrogen nor androgens (testosterone or DHT) affected subcutaneous adipose tissue leptin production. Dexamethasone (10nM) stimulated adipose tissue leptin production 3-fold (P < 0.001).

CONCLUSION

In regression analysis, where both insulin and measurements of fat mass were taken into account, androgens or estrogens did not independently contribute to the variation in leptin levels. Estrogens and androgens had no direct effects on adipose tissue leptin production in vitro. Thus, the sexual dimorphism evident in serum leptin is not likely to be due to a direct influence of sex hormones on leptin production in females.

Increased body fat mass and suppression of circulating leptin levels in response to hypersecretion of epinephrine in phenylethanolamine-N-methyltransferase (PNMT)-overexpressing mice

Epinephrine is a major stress hormone that plays a central role in the control of metabolic function and energy homeostasis. To evaluate the role of epinephrine and the physiological and pathophysiological consequences of sustained elevation of epinephrine on metabolic and endocrine function, we studied several metabolic parameters and circulating leptin levels in a newly developed transgenic mouse model of phenylethanolamine-N-methyltransferase (PNMT) overexpression. A 100-fold overexpression of PNMT and subsequent elevation of epinephrine levels resulted in a marked suppression of circulating leptin levels in the transgenic animals (1.14 +/- 0.05 vs. 2.17 +/- 0.35 ng/ml; P < 0.01), which correlated negatively with plasma epinephrine (r = -0.82; P < 0.05), thus providing evidence for an inhibitory action of epinephrine on leptin production in vivo. In parallel, we found a marked increase in the body fat content of the transgenic animals (12.54 +/- 1.5 vs. 6.22 +/- 0.2%; P < 0.01) that was accompanied by enlarged adipocytes, indicating an increased lipid storage in PNMT transgenic mice. Interestingly, however, transgenic animals had normal body weight and did not exhibit major alterations in carbohydrate metabolism, as evidenced by analysis of random and fasted blood glucose levels, plasma insulin and C peptide levels, and insulin tolerance test. The metabolic alterations observed were not secondary to changes in food intake or increased activity of the hypothalamic-pituitary-adrenal axis, as there were no differences in these parameters. In summary, sustained primary overproduction of epinephrine resulted in suppression of plasma leptin levels and increased lipid storage in the PNMT transgenic mice. The concerted action of the sympathoadrenal system and reduced leptin may contribute to defending energy reservoirs while maintaining a normal body weight, which may be of vital importance under conditions of stress and energy deficiency.

Systemic administration of epidermal growth factor reduces fat mass in rats: effects on the hormone-sensitive-lipase, lipoprotein lipase and leptin

We examined whether the reduction in fat mass induced by EGF treatment in mature animals was via activation of hormone-sensitive lipase (HSL) and thereby the induction of lipolysis, or through inhibition of lipoprotein lipase activity thus reducing fat uptake in adipose tissue. Sixteen male rats were treated with placebo or EGF 150 microg/kg/day for 7 days via mini-osmotic pumps. The results demonstrate that systemic EGF treatment reduces the amount of adipose tissue, most likely due to increased lipolysis as HSL activity as well as HSL mRNA were increased. The circulating levels of free fatty acids were slightly increased and leptin levels reflected the decrease in adipose tissue mass.

Erythrocyte-methotrexate and disease activity in children treated with oral methotrexate for juvenile chronic arthritis

The concentration of methotrexate (MTX) in erythrocytes (E-MTX) was measured twice with three months interval in 21 children suffering from juvenile chronic arthritis (JCA). At the same time joint score, visual analogue scale (VAS), and laboratory parameters (CRP, WBC, PMNs, and ALAT) were obtained. There was only a weak insignificant correlation between the dose of MTX/m2 and E-MTX (r=0.24, p=0.11). No significant relations between the clinical or laboratory parameters and E-MTX was found. However, ALAT above normal range was associated with a lower dose of MTX (p=0.02) and lower VAS (p=0.02), indicating that toxicity may be associated with less articular discomfort. At present we consider routine determination of E-MTX in children with JCA of limited value.

Regulation of uncoupling protein (UCP) 2 and 3 in adipose and muscle tissue by fasting and growth hormone treatment in obese humans

OBJECTIVE

To investigate whether the expression of uncoupling proteins (UCP2 and UCP3) was affected by a very low calorie diet (VLCD) and growth hormone (GH) treatment for 4 weeks.

DESIGN

A randomized, placebo-controlled intervention study of VLCD with or without concomitant GH-treatment.

SUBJECTS

Seventeen obese women (body mass index, BMI=42.1+/-1.4 kg/m2 (range 31.8-54.5 kg/m2)) treated with VLCD for 4 weeks and randomized to concomitant placebo treatment (n=9) or GH treatment (n=8).

MEASUREMENTS

Fat mass and lean body mass were measured by dual-energy X-ray absorptiometry. Energy expenditure (EE) was measured by indirect calorimetry. UCP2 and UCP3 mRNA were measured in adipose tissue and skeletal muscle biopsies before VLCD and after VLCD+/-GH-treatment by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

VLCD treatment resulted in a mean weight loss of 5.23 kg+/-0.8 (P<0.01), a 4.1% decrease in EE (P<0.05) and a 24% decrease in UCP3 mRNA in adipose tissue (P<0.03), whereas adipose tissue UCP2 mRNA and skeletal muscle UCP2 and UCP3 mRNA levels were unchanged. GH-treatment had no effects on EE, changes in body weight or UCP mRNA level. In multiple regression analysis the change in EE caused by VLCD was significantly correlated with changes in adipose tissue UCP2 mRNA (r=0.66, P<0.02) and a tendency towards a significant association with the change in adipose tissue UCP3 mRNA (r=0.45, P=0.09), but not with change in body weight, skeletal muscle UCP2 or UCP3 mRNA levels.

CONCLUSION

VLCD for 4 weeks decreased UCP3 mRNA expression in human adipose tissue, whereas GH-treatment had no effect on UCP expression. Multiple regression analysis demonstrated that changes in adipose tissue UCP2 and probably UCP3 mRNA were correlated with the change in EE. These findings indicate that UCPs in adipose tissue in very obese individuals might play a role for the reduction in EE observed during energy restriction.

Regulation of lipoprotein lipase and hormone-sensitive lipase activity and gene expression in adipose and muscle tissue by growth hormone treatment during weight loss in obese patients

It is well known that growth hormone (GH) treatment reduces fat mass (FM), which presumably is mediated through stimulation of triglyceride breakdown and inhibition of adipose tissue lipoprotein lipase activity (AT-LPL). However, it is unknown which of the 2 GH-regulated pathways are of most importance for the reduction in FM. We investigated the effect of weight loss together with GH treatment on the activity and gene expression of LPL and hormone-sensitive lipase (HSL) in AT and muscle tissue. A very-low-calorie diet ([VLCD] 740 kcal/d) was given to 18 obese women (body mass index [BMI] > 35 kg/m2) and half of them were treated with GH (0.04 IU/kg) for 4 weeks in a randomized double-blind placebo-controlled study. Subcutaneous fat and muscle biopsies were taken before and after 4 weeks. Weight loss after 4 weeks was similar in the 2 groups, with a reduction of 4.5% (placebo) and 4.6% (GH) and a reduction of FM by 7.4% and 9.0% ([NS] nonsignificant). The weight loss resulted in a small and NS reduction of AT-LPL activity by 20% +/- 12% in the placebo group, but in the GH group, AT-LPL was significantly reduced by 65% +/- 8% (P < .01). Muscle LPL (M-LPL) activity was not affected by the weight loss alone, but a significant reduction was observed in the GH group (20.4% +/- 10%, P < .05). AT-HSL activity was significantly enhanced after weight loss, but GH had no additional effect on this minor increment. This is in accordance with the finding that the increment in free fatty acid (FFA) after weight loss was similar in the 2 groups. GH treatment was associated with a significant reduction of high-density lipoprotein (HDL) cholesterol (P < .05). In conclusion, GH significantly inhibited AT-LPL activity but had no additional effect on the hypocaloric-induced loss of FM, indicating that under such circumstances, AT-LPL does not directly regulate adipose tissue mass. GH was not found to have opposite effects on the activity of LPL in adipose tissue and muscle, since GH treatment reduced them both (by 65% and 20%, respectively). The VLCD-induced weight loss was associated with a minor enhanced activity of AT-HSL with no independent effect of GH. Thus, concerning body weight, FM, and lipolytic activity, treatment with GH offers no extra benefits during a VLCD for 4 weeks.

Regulation of leptin by thyroid hormone in humans: studies in vivo and in vitro

The influence of thyroid hormones on human adipose tissue leptin production and leptin gene expression was investigated in vitro and in vivo. Twelve women received 60 microg triiodothyronine (T3) per day for 7 days, which increased total T3 by 195% (1.78 +/- 0.07 to 5.25 +/- 0.39 mU/L, P < .001), significantly decreased thyrotropin ([TSH] 1.57 +/- 0.40 to 0.03 +/- 0.01 mU/L, P < .01), and increased energy expenditure (1,602 +/- 32 to 1,754 +/- 34 kcal/24 h, P < .05). However, serum leptin did not change (9.36 +/- 1.6 v 8.90 +/- 1.3 microg/L, nonsignificant). Human subcutaneous adipose tissue biopsies from eight healthy women were incubated in vitro as small fragments with T3 in concentrations from 1 to 50 nmol/L. Leptin production was inhibited dose-dependently. After 24 hours of incubation, a T3 concentration of 50 nmol/L reduced basal leptin production by 42% (P < .05) and the stimulated leptin production (dexamethasone 10 nmol/L) by 52% (P < .05). Leptin mRNA expression was measured by a semiquantitative multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) method. Fifty nanomolars T3 decreased basal leptin mRNA expression by 47% compared with controls (P < .001), and the stimulated leptin mRNA expression was reduced to a similar degree (53%). In conclusion, in human adipose tissue, T3 (>20 nmol/L) inhibited leptin production and leptin gene expression in vitro, whereas an elevation of T3 corresponding to a moderate thyrotoxic state (T3 5.25 +/- 0.39 nmol/L) was without any impact on serum leptin levels in vivo.

Regulation of uncoupling protein-2 and -3 by growth hormone in skeletal muscle and adipose tissue in growth hormone-deficient adults

The newly described uncoupling proteins, UCP2 and UCP3, may play a role in regulating energy expenditure (EE) in humans. GH deficiency (GHD) is associated with decreased lean body mass, increased adiposity, and reduced EE, which are reversed by GH treatment. In the present study we investigated whether GH treatment for 4 months influenced the expression of UCPs in skeletal muscle and adipose tissue in 22 GHD patients who were investigated before and after GH (n = 11) or placebo (n = 11) treatment. GH treatment increased the amount of lean body mass by 4.5% (P < 0.05) and decreased body fat mass by 12% (P < 0.05), whereas no changes in these parameters were observed after placebo treatment. The level of UCP3 messenger ribonucleic acid (mRNA) increased 3-fold (P < 0.005) in skeletal muscle and almost 2-fold (P < 0.05) in adipose tissue after GH treatment, with no changes observed after placebo treatment. Skeletal muscle UCP2 mRNA was slightly (25%), but significantly (P < 0.05), decreased, whereas the level of UCP2 mRNA in adipose tissue was unaffected after GH treatment. The T4 level was positively correlated with skeletal muscle UCP2 and UCP3 expression (r = 0.518; P < 0.05 and r = 0.463; P < 0.05, respectively). Furthermore, plasma free fatty acids were positively correlated with the expression of UCP2 (r = 0.573; P < 0.01) and UCP3 (r = 0.518; P < 0.05) in skeletal muscle. The marked increase in UCP3 expression after GH treatment indicates that the UCPs might play a role in the effects of GH on EE in GHD patients. Finally, the strong association between thyroid hormone and skeletal muscle UCP and the correlation between plasma free fatty acids and UCP expression in skeletal muscle indicate that these hormones/metabolites might influence UCP expression in humans as previously demonstrated in rodents.

The insulinotropic effect of endothelin-1 is mediated by glucagon release from the islet alpha cells

AIMS/HYPOTHESIS

The circulating concentrations of endothelin-1 (ET-1), a peptide derived from endothelium, are increased in hypertension and diabetes. Endothelin-1 has recently been shown to be an insulinotropic agent. The mechanism of action of endothelin-1 on the endocrine pancreas has not yet been clarified.

METHODS

We investigated the action of endothelin-1 on the insulin secretion, the binding of (125)I-ET-1 to beta cells as well as its effects on purified beta and non-beta cells from normal rats. The expression of endothelin receptors in alpha- and beta-cell lines and in normal rat islets was also studied.

RESULTS

First, we studied the effects of endothelin-1 on insulin secretion from beta-cell lines (INS-1, betaTC3 and MIN6). At all endothelin-1 concentrations applied (1 pmol/l to 1 micromol/l) no change in insulin secretion was found. Ligand-binding experiments on betaTC3 cells showed no specific binding of (125)I-ET-1. A prominent expression of ET(A)-receptor mRNA in an alpha-cell line (alphaTC1.9) and in normal rat islets was found whereas no expression was found in INS-1 cells. No influence of endothelin-1(1 micromol/l) on insulin secretion stimulated by glucose was detected from purified beta cells. Endothelin-1-(100 nmol/l) increased, however, both insulin and glucagon secretion from a mixture of purified beta and non-beta cells indicating that alpha cells seem to have a key role for the action of ET-1 on insulin secretion.

CONCLUSION/INTERPRETATION

The insulinotropic impact of endothelin-1 is not caused by a direct action on the beta cells but seems to be mediated by a paracrine action, probably secondary to enhanced release of glucagon from the endothelin receptor positive alpha cells. [Diabetologia (1999) 42: 1302-1307]

Hormone replacement therapy affects body composition and leptin differently in obese and non-obese postmenopausal women

Leptin and oestrogen are both involved in the regulation of adipose tissue deposition and feeding behaviour. We investigated whether 5 years of hormone replacement therapy (HRT) affected serum leptin and body composition differently in 89 postmenopausal women treated with HRT compared with 178 controls. At baseline, leptin was significantly correlated with oestradiol (r=0.13, P<0.05) and in multiple backward regression analysis including oestradiol and any estimate of body fat, oestradiol remained a significant determinant of leptin levels. In the control group, all estimates of body fat determined by dual energy X-ray absorptiometry (DEXA) or anthropometry were increased (3.6-16.9%) and leptin increased 31.3% (16.03+/-1.02 to 20.84+/-1.2 ng/ml (s.e.m.), P<0.001). In the HRT group all estimates of body composition also increased during the 5-year observation but to a lesser extent than observed in the control group (1.0-8.5%). Leptin was raised by 19.7% (17.81+/-1.32 to 20.57+/-1.65 ng/ml, P<0.001). However, the DEXA scans revealed that the control group gained 2.4-fold more fat during the 5-year observation (1.9+/-0.3 vs 0.8+/-0.4 kg, P<0.05), and especially the trunk fat increased (1.4+/-0.2 vs 0.7+/-0.3 kg, P<0.05). This was reflected in the increase in leptin levels, which were increased by 7.4% in the control group compared with the HRT group (4.81+/-0.60 vs 2.76+/-0.87 ng/ml, P<0.05). Adjusting for the difference in adipose tissue revealed that HRT had no independent effect on leptin levels. Comparisons between obese (body mass index>25 kg/m(2)) and non-obese (<25 kg/m(2)) subjects by stratifying for HRT treatment using multiple linear regression revealed that the change in fat mass was significantly less among treated subjects (P=0.038) and especially in the non-obese subjects (P=0.001). The change in trunk fat was similarly correlated with treatment status (P=0.029) and with the degree of obesity (P=0.006). In conclusion, 5 years of HRT treatment significantly reduced fat mass accumulation, especially in the trunk region. This effect of HRT was more pronounced in non-obese as compared with obese subjects. The HRT-induced reduction in fat mass seems not to be mediated by leptin.

Regulation of leptin by steroid hormones in rat adipose tissue

We investigated if steroid hormones regulate the secretion and the expression of leptin in female and male rat adipose tissue fragments in vitro. Dexamethasone time and dose-dependently increased the secretion and mRNA expression of leptin with a half-maximal stimulation of approximately 1 nM. A time-course revealed a maximal stimulatory effect of 17 beta-estradiol after 24 hours. In male adipose tissue 17 beta-estradiol increased leptin secretion (32% by 50 nM 17 beta-estradiol, P = 0.07 and 34% by 500 nM 17 beta-estradiol, P < 1780.05) after 24 hours. An additional effect of estrogen was seen in the dexamethasone (50 nM) stimulated cells (38% with 50 nM 17 beta-estradiol, P < 0.05 and 48% by 500 nM 17 beta-estradiol, P < 0.05). Basal secretion of leptin was equal in female and male adipose tissue, whereas the effects of 17 beta-estradiol (50 nM) and dexamethasone were significantly increased in female as compared with male adipose tissue. Progesterone, testosterone, dihydrotestosterone and dehydroepiandrostendione-sulfate neither affected leptin secretion in male nor female adipose tissue in vitro. Furthermore, to investigate the effect of estrogen female rats were ovariectomized (OVX) and the adipose tissue was incubated in vitro and compared with adipose tissue leptin secretion from sham operated rats (SHAM), and with ovariectomized rats treated with 17 beta-estradiol (EST). A decreased basal and dexamethasone-stimulated leptin secretion from OVX rats compared with SHAM rats was found (P < 0.005) whereas 17 beta-estradiol treatment of ovariectomized rats maintained a normal leptin secretion. However, the dexamethasone stimulation was equally increased above basal levels in SHAM, OVX and EST rats (3.7 +/- 1.2, 2.9 +/- 0.8, 4.2 +/- 1.4, NS, ANOVA) respectively.

Enantioselective high-performance liquid chromatographic method for the determination of methadone and its main metabolite in urine using an AGP and a C8 column coupled serially

A simple and sensitive method for the enantioselective high-performance liquid chromatographic determination of methadone and its main metabolite, EDDP, in human urine is described. (-)-(R)-Methadone, (+)-(S)-methadone, (+)-(R)-EDDP, (-)-(S)-EDDP and imipramine as an internal standard are detected by ultraviolet detection at 200 nm. The enantiomers of methadone and EDDP were extracted from human urine by a simple liquid-liquid extraction procedure. The extracted sample was reconstructed in mobile phase and the enantiomers of methadone and EDDP were quantitatively separated by HPLC on a short analytical LiChrospher RP8 column coupled in series with a chiral AGP column. Determination of all four enantiomers was possible in the range of 0.03 to 2.5 microM. The recoveries of methadone enantiomers and EDDP enantiomers added to human urine were about 90% and 80%, respectively. The method was applicable for determination of methadone enantiomers and the enantiomers of its main metabolite in urine samples from methadone maintenance patients and patients suffering from severe chronic pain.

[The auto- and endocrine function of the adipose tissue. Significance for metabolic complications in obesity]

The present review discusses recent research showing adipose tissue to be highly metabolically active, producing and releasing many different bioactive compounds besides free fatty acids (FFA) such as tumor necrosis factor alpha (TNF alpha), leptin, acetylation stimulating protein (ASP), plasminogen activator inhibitor-1 (PAI-1), cholesterol ester transfer protein (CETP), prostaglandins and oestrogens. Most of these compounds have autocrine effects on the adipose cells and they are presumably involved in the physiological regulation of blood flow, growth and metabolism of the adipose tissue. When the adipose tissue becomes enlarged, as seen in association with obesity, it has now been shown that several of the compounds produced in the adipose tissue (TNF, PAI-1, CETP etc.) may be directly involved in the pathogenesis of some of the complications commonly seen in association with obesity such as insulin resistance, hypertension, enhanced thrombogenesis, and premature atherosclerosis.

Serum leptin levels and leptin expression in growth hormone (GH)-deficient and healthy adults: influence of GH treatment, gender, and fasting

Growth hormone (GH) treatment is associated with a reduction in fat mass in healthy and GH-deficient (GHD) subjects. This is mainly mediated via a direct GH action on adipose cells and stimulation of lipolysis. Leptin is secreted from adipose tissue and may be involved in signaling information about adipose tissue stores to the brain. Hormonal regulation of leptin is still not fully elucidated, and in the present study, we investigated both the long-term (4-month) and short-term (28-hour) GH effects on serum leptin and leptin gene expression in subcutaneous adipose tissue. In GHD adults (n = 24), leptin correlated with most estimates of adiposity (r = .62 to .86), as previously found in healthy subjects. However, no correlation was observed with intraabdominal fat determined by computed tomographic (CT) scan (INTRA-CT). GH treatment for 4 months had no independent effect on either serum leptin or leptin gene expression. In a short-term study, we found that fasting gradually reduced leptin levels in both healthy men and GHD adults, with a maximum reduction of 58% to 60% (P < .01) after 31 hours. No independent effect of GH suppression or GH substitution on serum leptin was found during fasting. Adipose tissue leptin mRNA correlated with serum leptin (r = .51, P < .01) and the body mass index ([BMI] r = .55, P < .05). Serum leptin levels and gene expression were significantly higher in women compared with men (26.6 +/- 5.8 v 10.0 +/- 1.30 ng/mL, P < .05). However, in regression analysis accounting for the gender differences in subcutaneous femoral adipose tissue (FEM-CT), the difference in serum leptin disappeared, indicating that subcutaneous femoral fat or factors closely related to femoral fat (eg, sex hormones) may be causal factors for the gender difference in leptin.

Epidemiology of respiratory syncytial virus infection requiring hospitalization in East Denmark

BACKGROUND

Prophylaxis against infection caused by respiratory syncytial virus (RSV) with high titered RSV immunoglobulin or humanized antibody may soon be available in Europe.

OBJECTIVE

To study the epidemiology of RSV infections requiring hospitalization in infants <6 months in East Denmark to provide a rational basis for decisions concerning prophylaxis against RSV.

METHOD

Populat ion-based retrospective review of case records of infants <6 months admitted to pediatric departments with RSV infection in East Denmark from November 1, 1995, to April 30, 1996.

RESULTS

Data were obtained from 459 infants. Seventy-three had predisposing conditions: prematurity, 49; pulmonary disease, 2; congenital heart disease, 7; neurologic disease, 6; others, 9. One preterm infant had bronchopulmonary dysplasia. The incidence of RSV infection requiring hospitalization in East Denmark among infants <6 months was estimated to be 34/1000/season. It was 32/1000/season among term infants and 66/ 1000/season among preterm infants (P<0.001). Infants with predisposing conditions and/or nosocomial infection (n = 24) had significantly more severe courses than otherwise healthy infants (P<0.01). One-hundred thirty infants received respiratory support by nasal continuous positive airway pressure, but only six required mechanical ventilation. No infants died.

CONCLUSION

The course of RSV disease in East Denmark was milder than reported elsewhere, possibly as a result of the low prevalence of bronchopulmonary dysplasia in Denmark. However, RSV constitutes a considerable burden to the Danish pediatric health care system, and therefore prophylaxis against RSV is desirable.

Major haemorrhagic complications during oral anticoagulant therapy in a Danish population-based cohort

OBJECTIVES

To estimate the incidence of bleeding leading to death or hospital admission in out-patients treated with oral anticoagulants.

DESIGN

Population-based historical cohort study 1 January 1992 to 31 September 1994.

SETTING

The County of North Jutland, Denmark (488,000 inhabitants).

SUBJECTS

Six hundred and eighty-two consecutive patients commencing oral anticoagulant therapy.

MAIN OUTCOME MEASURES

Fatal bleeding or bleeding demanding hospital admission.

RESULTS

In 756 treatment-years of follow-up, there were 45 major haemorrhagic events (6.0 per 100 treatment-years) in 42 patients, of which seven (0.9 per 100 treatment-years) were fatal. The risk of a first major haemorrhagic episode was highest during the first 90 days of treatment compared with duration above one year (incidence rate ratio, IRR, 1.9; 95% CI, 0.8-4.1). The rate was highest above the age of 60 years, 6.8 per 100 treatment-years, compared with 2.9 per 100 treatment-years below 60 years (IRR 2.3; 95% CI, 1.0-5.6). The rate for a bleeding event was slightly higher in females than in males (IRR 1.3; 95% CI, 0.7-2.3), but did not vary according to type of anticoagulant drug.

CONCLUSIONS

The reported rates of major bleeding in this routine community setting implied a higher bleeding risk than was found in randomized trials or when patients are monitored in specialist anticoagulation clinics.

Effects of long-term total fasting and insulin on ob gene expression in obese patients

In the present study the effect of long-term fasting (6 days) on obese (ob) gene expression was examined in nine severely obese females of 34 +/- 3 years and with a body mass index of 46.4 +/- 2.3 kg/m2. Six days of fasting induced a significant weight loss (126.8 +/- 5.3 vs 120.5 +/- 5.1 kg, P < 0.0001). Insulin-stimulated glucose uptake (hyperinsulinemic, euglycemic clamp, insulin infusion rate 1.5 mU/kg per min) was markedly reduced following fasting (M-value 5.96 +/- 0.74 vs 2.79 +/- 0.23 mg/kg per min, P < 0.0001). Ob mRNA/beta-actin concentration in fat biopsies from abdominal subcutaneous adipose tissue was unchanged after 6 days of fasting (1.50 +/- 0.40 vs 1.47 +/- 0.36 arbitrary units, not significant), whereas serum leptin levels decreased significantly from 53.8 +/- 4.7 to 30.7 +/- 2.0 ng/ml (P < 0.0001) during the same period. No significant correlations were found between insulin-stimulated glucose uptake and serum leptin concentration, either prior to the fast or after the fast. Serum leptin levels were unchanged by hyperinsulinemia for 3 h during the clamp prior to the fast, while hyperinsulinemia for 3 h after 6 days of fasting increased serum leptin by 25% (P < 0.01). In conclusion, 6 days of fasting reduced serum leptin by about 40%. In contrast, ob mRNA in abdominal subcutaneous adipose tissue was unchanged. Furthermore, after 6 days of fasting insulin was able to increase the serum level of leptin significantly, indicating that the effect of insulin on the level of leptin is dependent on the nutritional state.

Vitamin D deficiency in pregnant and breast-feeding women and their infants

We describe the cases of five consecutive infants with symptomatic vitamin D deficiency and their mothers. Four of the infants were light skinned, all had poor sunlight exposure, and all were breast-fed or had diets low in vitamin D. All mothers had vitamin D deficiency. Regardless of race, infants with poor sunlight exposure and diets lacking in vitamin D are at risk for vitamin D deficiency. Mothers of these infants should be evaluated for vitamin D deficiency. Vitamin D supplementation of the breast-feeding mother at risk and her infant is recommended.

Long-term (6 months) effect of a new fermented milk product on the level of plasma lipoproteins--a placebo-controlled and double blind study

OBJECTIVE

We have recently demonstrated a short-term hypocholesterolemic effect (reduction of 8-10%) of a new fermented milk product taken for 6 weeks (Agerbaek et al, 1995; Richelsen et al, 1993). The present study was undertaken to investigate the more long-term (6 months) effect of this fermented product on the level of lipoproteins.

DESIGN

The study was randomized, double-blind, and placebo-controlled, and performed for a period of six months.

SUBJECTS

Eighty-seven non-obese and normocholesterolemic females and males, aged 50-70 y old, were included in the study.

INTERVENTION

200 ml of either the fermented milk product or placebo (chemically fermented) were given daily. The test product was fermented with a bacteria culture containing Enterococcus faecium and two strains of Streptococcus termophilus.

RESULTS

After one month the total- and LDL-cholesterol were significantly reduced in the fermented milk group as compared to placebo, LDL was reduced by 0.21 mmol/l vs 0.0 mmol/1 (P < 0.02). The maximal reduction of LDL-cholesterol was reached after 3 months in the test group with a reduction of 0.32 mmol/1 of initial values (P < 0.001). In the placebo group a gradual fall of total- and LDL-cholesterol was observed from 1-6 months of the study. Thus, after six months the reduction of LDL-cholesterol was similar in the two groups (P = 0.95) even though the reduction was significant in both groups in relation to initial values (P < 0.05). No changes in HDL-cholesterol or triglyceride were observed during the study. There were no differences in the response between women and men.

CONCLUSION

The fermented milk product resulted in a rapid reduction of LDL-cholesterol observed after one month but during long-term intake (6 months) the reduction of LDL-cholesterol was similar to the placebo product, indicating that low-fat milk or fermented milk products may have some hypocholesterolemic effects but the present tested product does not seem to be superior in that respect to the placebo milk product used in the present study.

[Vaccination of premature infants]

The article gives a review of the literature concerning immunization of preterm infants. The initial response to diphtheria-tetanus-whole-cell-pertussis vaccine and inactivated polio vaccine may be impaired in preterms, but after two and three doses the responses to these vaccines is comparable to those of term infants of the same chronological age. Likewise, the response to oral polio vaccine is normal and independent of gestational age after two and three doses in preterm infants. After two doses, the response to Haemophilus influenzae type b conjugate vaccine is impaired in preterm infants with very low gestational age, but comparable to that of term infants in preterms with higher gestational ages. After three doses the response to this vaccine is normal and unaffected by gestational age in preterms. Recombinant hepatitis b vaccine induces a reduced response in preterm infants even after three doses, and they may therefore need an extra dose of this vaccine. Studies of diphtheria-tetanus-whole-cell-pertussis vaccine and Haemophilus influenzae type b conjugate vaccine in preterm infants do not suggest that adverse effects occur more often or are more severe than those seen in term infants. The literature provides no background for postponement of immunizations in preterm infants.

Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

OBJECTIVE

To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants.

SUBJECTS

Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from 920 to 2550 g. Controls were 37 term infants.

METHODS

All infants were immunized with HibCP-TT at 2, 4 and 12 months of age. Antibodies to HibCP and TT were determined at each immunization and 1 month after the second and third.

RESULTS

After two doses of HibCP-TT the preterm infants with GAs < or = 30 weeks (n = 8; mean GA, 29.5 weeks) had a significantly lower HibCP antibody response than the preterm infants with GAs > 30 weeks (n = 23; mean GA, 34.2 weeks) (P = 0.004), who for their part had a response not significantly different from that of the term infants. After the third dose there were no significant differences among the groups. The response to the TT part of the vaccine showed the same pattern.

CONCLUSION

Although the most immature infants may show an inadequate antibody response to the initial immunizations, many preterm infants can benefit from vaccination with HibCP-TT when starting immunization at the same chronologic age as term infants.

Stereoselective pharmacokinetics of methadone in chronic pain patients

Ten patients with chronic pain were randomized to an open, balanced, crossover study. Each patients received two different preparations of racemic methadone, i.e., tablets and intravenous infusion. The pharmacokinetic parameters of the R- and S-enantiomers of the racemate are reported. The analgesically active R-methadone has a significantly longer mean elimination half-life than the optical antipode S-methadone (t1/2 = 37.5 and 28.6 h, respectively). The mean total volume of distribution is 496.6 L for R-methadone and 289.1 L for S-methadone. Significant differences in the mean clearance between R- and S-methadone are seen (0.158 and 0.129 L/min, respectively). However, the lagtime after oral administration and the bioavailability did not show differences between the isomers. The data suggest that both enantiomers of methadone should be measured if correlations between pharmacodynamics and kinetics are made due to the stereoselective differences in half-life, total volume of distribution, and clearance.

[Use of blood products in Denmark in 1993. Regional differences and comparison with other Scandinavian and European countries]

In Denmark approximately 396,000 units of blood were collected during 1993 from among approximately 270,000 voluntary non-renumerated blood donors corresponding to about 76 donations per 100 inhabitants. Almost all units (approx. 99%) were fractionated into blood components in the blood banks. Approximately 16,000 erythrocyte units were rejected due to technical errors or quality control, while around 37,000 erythrocyte units were discarded from stock. Only 190 units were transfused as whole blood. In all 327,108 SAG-M erythrocyte suspensions, 70,971 thrombocyte concentrates, 50,161 units of fresh frozen plasma, FFP, and approximately 1700 kg albumin, 100% were transfused, corresponding to 63, 14 and 10 units and 340 g per 1000 inhabitants. When compared to other Scandinavian and European countries, Denmark has a high consumption of erythrocyte components, FFP and albumin for transfusion. The reason why cannot be clarified by available data, but it is not unlikely that Denmark has a more liberal transfusion policy than the other countries. There are considerable differences within Denmark as regards the clinical use of blood products. Counties/regions with university hospitals and regional and/or national functions tend to have a relatively high consumption. However, no information exists on consumption related to demographic parameters or related to hospitals, departments or diagnoses.

Adherence of chewing gum to dental restorative materials

PURPOSE

To describe a method whereby chewing gum tackiness can be measured.

MATERIALS AND METHODS

The chewing gum used for the experiment was V6 (Freshmint). Paladur denture base material, Silux Plus, P-50 and Heliomolar resin composites and Luxalloy amalgam were used. Squared specimens (15 x 15 x 2 mm) composed of the polymerized materials tested or set amalgam were made with a mold. As gold specimen, a gold-plated brass specimen was used, having the same dimension as specified above. A tooth enamel specimen (5 x 5 mm) was made out of flat ground human enamel from an incisor. All specimens were stored for more than 7 days in water before use, and wet ground on paper No 320 immediately before testing. The adhesion was measured by a balance equipped with a recorder and a bottom attachment, to which a chain was mounted. The end of the chain was attached to a quadratic brass plate, to which one of the above described specimen was glued by cyanoacrylate. Another brass plate, with an attached specimen of the same material, was mounted in a small vise in such way that the two specimens were parallel with and facing each other. A motor drive enabled parallel removal of the two plates from each other. The gum was chewed approximately 1 second between bites and for various periods of time. It was then pressed between the two parallel squares (mentioned above) of restorative materials or enamel, reaching a final distance of 1 mm between the plates and occupying the entire space between the plates. The study was carried out at 36 degrees C, and the two plates were wetted with fresh saliva or water immediately before placement of the chewing gum. Excess liquid was removed after the wetting, leaving a thin film. The maximal force during parallel removal of the two plates from each other was recorded. The measurements were performed eight times in each group, and the mean adhesion per surface area and SD was expressed as mN/mm(2). The measurements were repeated for some of the groups. The significance of differences between each group was tested by Newman-Keul's Multiple Range Test at a 5% level of significance.

RESULTS

Adherence of chewing gum to dental restorative materials and enamel was found to decrease as follows: denture base material > resin composites = silver amalgam > gold > human enamel. The adhesion was dependent on gum base and not on the sweetening additives and reached a maximum after about 2 minutes' chewing.

Characterization of the antibody response to a Haemophilus influenzae type b conjugate vaccine in children with recurrent lower respiratory tract infection

Children with recurrent lower respiratory tract infection (RLRI) may respond poorly to polysaccharide antigens. To examine how such children respond to a polysaccharide coupled to a protein carrier, we immunized 15 children with RLRI aged 8-69 months and 15 carefully age-matched healthy controls once with a Haemophilus influenzae type b (Hib) conjugate vaccine. Total IgG subclasses, total antipolysaccharide Hib antibodies, and antipolysaccharide Hib antibodies of IgM, IgG, IgA, and IgG1-4 specificity were determined by ELISA. There were no significant differences between the two groups in any single total IgG subclass, but total IgG measured as the sum of all four subclasses was significantly lower in the children with RLRI than in the controls (P = 0.036). Before vaccination, the children with RLRI had significantly less IgG antipolysaccharide Hib antibody than the controls (P = 0.005), whereas 1 month later they had significantly more IgM antibody (P = 0.038). No other significant differences were found between the groups before or after immunization with respect to antipolysaccharide Hib antibodies. Since naturally occurring IgG antibodies are thought to be acquired partly as a consequence of antigenic stimulation on mucosal surfaces, we hypothesize that the low level of specific IgG found before immunization, as well as the low total IgG in the children with RLRI, may reflect an impaired ability to prime through mucosal surfaces. This is supported by our finding of an increased IgM response to Hib conjugate vaccine in these children, since this isotype predominates in the primary immune response, i.e., in the absence of immunologic memory.(ABSTRACT TRUNCATED AT 250 WORDS)