Fertility and Pregnancy in Primary Adrenal Insufficiency in Germany.

Autoimmune adrenalitis (AA) and congenital adrenal hyperplasia (CAH) are the most common reasons for acquired and monogenetic primary adrenal insufficiency. Both concern women in their fertile years. The aim of the work was to examine fertility rates, pregnancy outcome, and children's characteristics in AA and CAH patients in 2 German endocrine centers. One hundred and fifty-eight women were contacted. Thirty-nine patients with CAH due to 21-hydroxlase deficiency and 54 AA patients agreed and were included. Information about course and outcome of pregnancies was obtained by questionnaire and telephone interview. Fertility rates were calculated and compared to expected values from the German general population. Twelve CAH patients (30.8%) had 25 pregnancies, which resulted in 16 children. In AA patients, 93 pregnancies in 42 women (75%) were reported resulting in 73 childbirths. Fertility rates were normal in nonclassic CAH and in AA-only patients, but significantly reduced in classic CAH and autoimmune polyendocrine syndrome type 2 (APS-2). Rates of miscarriages were high in all CAH (36%) and APS-2 (22%) patients. The majority of children in both groups were born at term, but rates of cesarean section were elevated in classic CAH and in AA patients<5 years before or after diagnosis. Children born to CAH patients weighed significantly less than expected and 33.3% of them were born small for gestational age. Fertility seems not to be reduced in general, but specific in classic CAH and APS 2 patients. Nevertheless all CAH and AA patients seem to be at risk of miscarriages and cesarean section.

Synchronous change of atmospheric CO2 and Antarctic temperature during the last deglacial warming.

Understanding the role of atmospheric CO2 during past climate changes requires clear knowledge of how it varies in time relative to temperature. Antarctic ice cores preserve highly resolved records of atmospheric CO2 and Antarctic temperature for the past 800,000 years. Here we propose a revised relative age scale for the concentration of atmospheric CO2 and Antarctic temperature for the last deglacial warming, using data from five Antarctic ice cores. We infer the phasing between CO2 concentration and Antarctic temperature at four times when their trends change abruptly. We find no significant asynchrony between them, indicating that Antarctic temperature did not begin to rise hundreds of years before the concentration of atmospheric CO2, as has been suggested by earlier studies.

Orbital and millennial Antarctic climate variability over the past 800,000 years.

A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, approximately 800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.

High-resolution record of Northern Hemisphere climate extending into the last interglacial period.

Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a North Greenland ice core, which extends back to 123,000 years before the present, within the last interglacial period. The oxygen isotopes in the ice imply that climate was stable during the last interglacial period, with temperatures 5 degrees C warmer than today. We find unexpectedly large temperature differences between our new record from northern Greenland and the undisturbed sections of the cores from central Greenland, suggesting that the extent of ice in the Northern Hemisphere modulated the latitudinal temperature gradients in Greenland. This record shows a slow decline in temperatures that marked the initiation of the last glacial period. Our record reveals a hitherto unrecognized warm period initiated by an abrupt climate warming about 115,000 years ago, before glacial conditions were fully developed. This event does not appear to have an immediate Antarctic counterpart, suggesting that the climate see-saw between the hemispheres (which dominated the last glacial period) was not operating at this time.

CO(2) concentration measurements on air samples by mass spectrometry

A new technique for measuring CO(2) concentration in air samples, based on mass spectrometry, is described as an alternative to the common gas chromatographic method. Using a dual inlet isotope ratio mass spectrometer (IRMS), the ratio of the abundances of the m/z peaks 44 and 28 is determined. The precision of measurements (standard deviation <3 ppmv) is generally as good as the analysis with gas chromatography for small air samples (<1 ml STP of air). A major advantage of this new method is the possibility of parallel elemental and isotopic measurements of many air components. The technique is further improved by new wide mass range mass spectrometers allowing simultaneous intensity measurements of several m/z values between 28 and 44, resulting in an uncertainty of <0.5 ppm. The precision is somewhat limited by the production of N(2)O and NO(2) from N(2) and O(2) in the ion source, which accounts for about half of the signal strength at m/z 44. Copyright 2000 John Wiley & Sons, Ltd.

16 degrees C rapid temperature variation in central greenland 70,000 years Ago

Variations in the (29)N(2)/(28)N(2) ratio of air bubbles trapped in polar ice cores and their relation to variations of the (18)O/(16)O of the ice allow past surface temperature variations and ice age-gas age differences to be determined. High-resolution measurements of (29)N(2)/(28)N(2) in Dansgaard-Oeschger event 19 (around 70,000 years before the present) in ice from Central Greenland show that at the beginning of the event, the ice age-gas age difference was 1090 +/- 100 years. With the use of a combined firn densification, temperature, and gas diffusion model, the delta(18)O(ice)-temperature coefficient alpha was determined to be 0. 42 +/- 0.05 per mil per kelvin. This coefficient implies a mean surface temperature change of 16.0 kelvin (between 14.3 and 18.1 kelvin), which differs substantially from values derived from borehole temperatures and modern spatial delta(18)O(ice)-surface temperature correlations.

Identification and characterization of the putative retinoblastoma control element of the rat insulin-like growth factor binding protein-2 gene.

The authors previously identified a silencer of the rat IGFBP-2 gene. Sequence examination of the silencer has revealed that it contains the target sequence for the pRb (retinoblastoma) tumour suppressor gene, referred to as the retinoblastoma control element (RCE) which is frequently found in the regulatory element of cellular oncogenes and growth factors. The presence of RCE suggests that the IGFBP-2 gene may be regulated by the pRb tumour suppressor gene. An in vitro gel retardation assay has shown that the putative RCEs from the IGFBP-2 gene are complexed with multiple nuclear factors from the rat liver BRL-3A cells. These DNA-protein complexes were not detected with the nuclear extracts from the cells that were growth arrested at the G1/S border of the cell cycle by high cell density. Using specific antibodies, Sp1 was shown to be one of the components for the multiple DNA-protein complex while pRb does not appear to be directly involved in the formation of the complex.

Cell-density (cycle) dependent silencer of the rat insulin-like growth factor binding protein-2 (IGFBP-2) gene.

An element which has a negative effect on transcription has been identified in the 5'-flanking region of the rat insulin-like growth factor binding protein-2 (IGFBP-2) gene. This element was confirmed to be a silencer by truncation or by linking it to a heterologous promoter. The silencer activity disappeared in the growth-arrested BRL-3A cells at the G1/S border by high cell density where the IGFBP-2 production is highly elevated. This observation may represent a novel mechanism through which gene expression is controlled by modulation of a silencer. Taken together, these results suggest a regulatory link between cell growth and IGFBP-2 expression regulated by its silencer.

Insulin-like growth factors (IGFs) and IGF binding proteins-1, -2, and -3 in newborn serum: relationships to fetoplacental growth at term.

Cord sera were obtained from term, Chilean newborns exhibiting various patterns of intrauterine growth and assayed for IGF-1, IGF-2, IGFBP-1, IGFBP-2, and IGFBP-3 by specific radioimmunoassays (RIA). Serum levels of each peptide were correlated with birth weight (BW), ponderal index (PI), and placental weight (PW). Total IGF-1 levels correlated with BW (r = 0.665, P = 0.0001). PI (r = 0.527, P = 0.004), and PW (r = 0.596, P = 0.0017). In contrast, IGF-2 failed to correlate with any growth parameter. Of the three binding proteins, IGFBP-3 exhibited the strongest relationship to each growth parameter. IGFBP-3 correlated significantly with BW (r = 0.71, P < 0.0001), PI (r = 0.782, P < 0.0001), and PW (r = 0.57, P = 0.0029). In addition IGFBP-3 levels positively correlated to IGF-1 levels (r = 0.614, P = 0.0005). By contrast, circulating IGFBP-1 and IGFBP-2 were inversely related to IGF-1 levels. All five peptides were subjected to multiple regression analysis and related to BW. Significant relationships between the predicted BW and the actual BW were observed in these infants (r = 0.802, P = 0.0006). The BWs of a cohort of unrelated North American infants were also predicted using the Chilean-derived equation and found to be significantly related to their actual BWs (r = 0.453, P = 0.0033). These relationships were strengthened by the inclusion of estimated gestational age (EGA) as an independent variable. These data point to particularly important roles for IGF-1 and IGFBP-3 in regulating fetal growth at term, and suggest that they are regulated in a coordinated manner during the latter stage of gestation. Furthermore, they suggest that IGFBPs play multiple, and potentially opposing, regulatory roles in modulating IGF action. Lastly, an integrated expression of IGF activity derived from one population significantly correlated with newborn BW in a geographically and culturally distinct population.

Influence of insulin-like growth factor-binding protein-2 on plasma clearance and transfer of insulin-like growth factors-I and -II from plasma into mammary-derived lymph and milk of goats.

Plasma clearance of insulin-like growth factors-I and -II (IGF-I and -II) and insulin-like growth factor-binding protein-2 (IGFBP-2) from lactating goats (n = 4) was determined following a single intravenous injection of the corresponding 125I-labelled human protein. Transfer of these proteins out of the vascular space was monitored by their subsequent appearance in mammary-derived lymph and milk. Clearance of 125I-IGFBP-2 from circulation was 0.37 +/- 0.06 ml/min/kg, which is markedly greater than that of 125I-IGF-I or -II (0.11 +/- 0.01 and 0.12 +/- 0.01 ml/min/kg respectively). This was also reflected in longer elimination half-lives for IGF-I (353 +/- 6 min) and -II (254 +/- 8 min) compared with IGFBP-2 (110 +/- 9 min). Three hours after injection of the 125I-labelled protein, the plasma:lymph ratio of trichloroacetic acid-precipitable radioactivity was 1.54 +/- 0.04, 3.3 +/- 0.6 and 4.1 +/- 0.4 for IGFBP-2, IGF-I and -II respectively. The form of 125I-IGFBP-2 in lymph was not different from that of plasma. Elevation of plasma concentrations of IGFBP-2 by its intravenous infusion significantly decreased plasma half-life of both IGF-I and -II (251 +/- 8 and 198 +/- 7 min respectively). Although the amount and rate of transfer of IGF into mammary-derived lymph was decreased slightly by IGFBP-2, concentrations eventually obtained were not different from control. However, secretion of IGFs into milk was significantly reduced by IGFBP-2, particularly in the case of IGF-I. These results are consistent with the ability of all three compounds to cross the vascular endothelium intact and of IGFBP-2 to decrease the uptake of IGF by mammary epithelium and subsequent secretion into milk. IGFBP-2 may well have acted to target plasma IGF towards non-mammary tissues, thus explaining the more rapid plasma clearance of IGFs in the presence of elevated IGFBP-2.

Cell-density-dependent modulation of the rat insulin-like-growth-factor-binding protein 2 and its gene.

The steady-state level of the rat insulin-like-growth-factor-binding protein 2 (IGFBP-2) and insulin-like-growth-factor-II (IGF-II) mRNA increased approximately 20-fold when BRL-3A cells were cultured at increasingly higher cell densities. This increase could not be accounted for by paracrine or autocrine factors, or by the addition of insulin, IGF-I, transforming growth factor beta (TGF-beta), cAMP or IGFBP-2 to the culture medium. A reporter gene assay carrying the promoter domain of the IGFBP-2 gene indicated that the promoter-dependent IGFBP-2 transcription is tenfold higher in high-density cells. The increase in the IGFBP-2 message was accompanied by an increase in the level of protein in the medium. When confluent BRL-3A cells were reseeded at low cell density, the IGFBP-2 mRNA disappeared at a rate significantly faster than in normal conditions. A protein synthesis inhibitor, cycloheximide, was able to prevent the decay of the message observed after the switch from high to low densities. In summary, these findings suggest a regulatory link between cell density and IGFBP-2.

Ontogeny of insulin-like growth factor-binding protein-1, -2, and -3: quantitative measurements by radioimmunoassay in human fetal serum.

There is evidence for a role for IGF-I in the endocrine control of human fetal growth despite the low serum IGF-I concentrations. The formation in serum of binary complexes between IGF-I or -II and either of six IGF binding proteins (IGFBP-1 to -6) and, in particular, of long-lived ternary complexes between IGF-I or -II, IGFBP-3, and acid-labile subunit is thought to regulate IGF-I bioavailability by increasing its serum half-life. The present study assesses the bioavailability of circulating IGF-I in 19- to 35-wk gestation human fetuses in utero 1) by quantitative RIA measurements of IGF and IGFBP in serum and 2) by examining whether serum proteolysis of IGFBP-3 may further increase IGF-I bioavailability. Fetal serum concentrations of IGFBP-3, IGF-I, and IGF-II were low with marked or only modest increases with gestational age (p < 0.001, p < 0.005, and p < 0.05, respectively). The mean molar ratio between IGF-I plus -II and IGFBP-3 demonstrated a molar excess of IGF (50%) similar to that in adolescents but in contrast to the 1:1 molar ratio in adults. The median IGFBP-2 concentration was 3-fold elevated to a molar concentration similar to that of IGFBP-3 (adult serum displays 10-fold higher IGFBP-3 concentrations). The median serum IGFBP-1 concentration was not elevated as previously reported in newborns. IGFBP-3 protease activity was not increased in fetal serum, in contrast to pregnancy serum and amniotic fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth hormone and parathyroid hormone stimulate IGFBP-3 in rat osteoblasts.

Osteoblast-like cells prepared from calvaria of newborn rats produce insulin-like growth factor (IGF) I and several insulin-like growth factor binding proteins (IGFBPs) in vitro. Among the IGFBPs found in conditioned cell culture medium, IGFBP-3 is the most abundant. Intact IGFBP-3, as assessed by 125I-labeled IGF-II ligand blot analysis, is more abundant in culture media of cells exposed to growth hormone (GH) or to parathyroid hormone (PTH), both at 5 x 10(-9) mol/l, for 24 h. At the same time, concentrations of IGF-I are increased in media of cells exposed to PTH but not to GH, compared with hormone-free control cultures. IGFBP-3 mRNA is increased in osteoblasts exposed to PTH or to GH but not in response to 5 x 10(-9) mol/l IGF-I. PTH exerts a rapid (within 2 h) stimulatory effect on IGF-I and IGFBP-3 production, both at the message and peptide levels, whereas GH increases only IGFBP-3, both at the message and peptide levels (after 24 h). We conclude that IGF-I does not mediate increased IGFBP-3 production by rat osteoblasts in response to GH and PTH.

[Neurocysticercosis]. / Neurozystizerkose.

A 49-year-old woman from Croatia, resident in Switzerland for 22 years, had a history of headaches and arterial hypertension for 8 years. While in hospital for assessment and treatment she developed focal seizures. She had an eosinophilia (10%) and computed tomography of the skull demonstrated cysts and multiple calcified foci in the left cerebral hemisphere. Antibodies against Taenia solium antigen were found in both serum and cerebrospinal fluid. Anthelminthic treatment with albendazole (15 mg/kg daily for 25 days) and anticonvulsive treatment with phenytoin (serum levels between 10 and 20 mg/l) markedly improved the symptoms and the cysts regressed. Neurocysticercosis, caused by the larvae of the pork tapeworm, is occurring even more frequently because of the migration of people from countries where the disease is endemic.

Insulin-like growth factors and their binding proteins in plasma and milk after growth hormone-stimulated galactopoiesis in normally lactating women.

We performed a double-blind randomized placebo-controlled trial of recombinant human growth hormone (hGH) in normally lactating women (N = 8 per group) to investigate the endocrine mode of action of the galactopoietic effect of this hormone. Insulin-like growth factors I (IGF-I) and II (IGF-II) and their binding proteins (IGFBP-1, IGFBP-2 and IGFBP-3) were measured by radioimmunoassay in plasma and milk samples collected throughout the study. All assays were validated for human plasma and milk. Human GH treatment (0.1 IU.kg-1 body wt.day-1 for 7 days) increased plasma concentrations of IGF-I from 22.1 +/- 1.3 nmol/l (mean +/- SEM) to 59.7 +/- 2.5 nmol/l (p < 0.01). At the end of the study the increase in plasma IGF-I correlated significantly with the increase in milk volume (r = 0.67, p < 0.005, N = 16). The IGF-I levels were considerably lower in milk, with 0.14 +/- 0.03 nmol/l before and 0.31 +/- 0.04 nmol/l after hGH treatment. The increase in milk IGF-I levels (134.0 +/- 14.5%) with hGH treatment was significant (p < 0.01) and plasma and milk IGF-I concentrations correlated significantly when considering all samples of the study (r = 0.45, p < 0.001, N = 56). The concentrations of IGF-II were not changed significantly with hGH treatment in plasma (52.5 +/- 2.5 nmol/l before and 42.6 +/- 3.9 nmol/l after treatment) or milk (2.1 +/- 0.29 nmol/l before and 2.3 +/- 0.49 nmol/l after hGH treatment).(ABSTRACT TRUNCATED AT 250 WORDS)

Role for membrane and secreted insulin-like growth factor-binding protein-2 in the regulation of insulin-like growth factor action in lung tumors.

The insulin-like growth factors (IGFs) have been implicated in the autocrine and/or paracrine growth of a number of tumor types, including lung tumors. Importantly, insulin-like growth factor-binding proteins (IGFBPs), which both enhance and inhibit the physiological and biological actions of the IGFs, have been shown to be secreted in vitro by a wide range of tumors. In particular, IGFBP-2 is frequently produced by human tumor cells, suggesting that this protein may be an important determinant of IGF action in tumors. In the present study, we investigated IGFBP-2 effects in lung tumor cells by examining the influence of IGFBP-2 on IGF-receptor interaction and the biological actions of IGF-I and IGF-II. Affinity cross-linking studies demonstrated expression of type-I and type-II IGF receptors on small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) cells and the presence of abundant membrane-associated IGFBP in SCLC cells but not in NSCLC cells. An antiserum specific for IGFBP-2 was used in immunoprecipitation and immunoblotting studies which demonstrated that the membrane-associated IGFBP identified by affinity cross-linking in SCLC cells is IGFBP-2. In NSCLC cells, both IGF-I and IGF-II bound predominantly to IGF-I receptors, whereas in SCLC cells binding was principally to surface-associated IGFBP-2. SCLC cells failed to respond to IGF-I and -II stimulation in a DNA synthesis assay. For NSCLC cells, IGF-II was a more potent stimulator of DNA synthesis than IGF-I. Soluble IGFBP-2 inhibited the binding of radiolabeled IGF-I and -II to both SCLC and NSCLC cells in a concentration-dependent manner and inhibited IGF-stimulated DNA synthesis in NSCLC cells. These observations indicate that both soluble and membrane-associated IGFBP-2 compete with IGF receptors for ligand binding and, thus, are likely to be important determinants of IGF responsiveness. The findings of the present study also indicate that the type-I receptor on NSCLC cells contains a high-affinity binding site for IGF-II which presumably mediates the biological effects of IGF-II in these cells, thereby implicating IGF-II in the autocrine/paracrine growth of NSCLC.

Circulating levels of IGFs and IGF binding proteins in human cord serum: relationships to intrauterine growth.

Cord sera were obtained from 44 term, human infants exhibiting various patterns of intrauterine growth and were assayed for IGF-1, IGF-2, and IGFBP-1, 2, and 3 by specific RIAs. Serum levels were correlated with birth weight (BW), ponderal index (PI), and placental weight (PW). Total IGF-1 levels correlated significantly with BW (r = 0.392), PW (r = 0.351), and PI (r = 0.481). By contrast, the correlation of IGF-2 with birth weight was not statistically significant (r = 0.264, P = 0.091). The association of IGF-2 with PI, however, was significant (r = 3.348, P = 0.024). IGFBP-3 exhibited significant correlations with BW, PI, and PW, similar to those seen with IGF-1. IGFBP-1 and IGFBP-2, however, were not significantly related to growth parameters. IGF-1 levels correlated strongly with IGFBP-3 levels (r = 0.646, P = 0.001). By contrast, IGF-1 correlated with the reciprocal of both IGFBP-1 and IGFBP-2. Based upon in vitro affinity constants, theoretical concentrations for each [IGF/IGFBP] complex, free IGFs, and free IGFBPs were calculated for each infant. Multiple regression analysis was performed including all 11 calculated variables and correlated with each growth parameter. This analysis revealed that an integrated expression of IGF activity exhibited stronger correlations with growth than each individual peptide species (BW, r = 0.681; PI, r = 0.660; PW, r = 0.658). These data further support roles for IGF related peptides (IGFRPs) in human fetal and placental growth and suggest regulatory/counterregulatory roles for the IGFBPs. It also supports the hypothesis that individual IGFRPs interact in a complex manner to define 'net IGF activity' in relation to fetal growth and/or metabolic status.

Genomic structure and regulation of the promoter of the rat insulin-like growth factor binding protein-2 gene.

We describe the complete genomic organization of the rat insulin-like growth factor binding protein-2 (rIGFBP-2) gene. This single-copy gene spans over 36 kilobases (kb) and is split into four exons of 475, 224, 141, and 472 nucleotides (nt), and three introns of 32 kb, 686, and 1793 nt, respectively. A single transcription start site (-90) was mapped by S1 protection assay and primer extension. The putative promoter of the rIGFBP-2 gene does not possess TATA or CAAT elements; however, it contains three GC-rich regions located 37, 57, and 81 nt 5' of the cap site. Deletion analysis of the 0.6-kb region of the upstream sequences and transfection of these constructs into BRL-3A and Chinese hamster ovary cells were used to localize possible cis-acting elements. The three GC boxes enhanced chloramphenicol acetyltransferase and luciferase transcription almost to the same level as the XbaI-NsphI (-579 to +1) fragment and displayed synergism and orientation dependence. In addition a similar positive effect on luciferase transcription has been obtained by cotransfecting these fragments with varying amounts of Sp1 expression vector into Drosophila cells that lack endogenous Sp1. In vitro gel mobility shift assays demonstrated that box 1 (GGGCGG), box 2 (GGGAGG), and box 3 (GGGAAGG) bind to SpI with variable affinities and display cooperativity. A protein that gave a similar DNA binding pattern was present in nuclear extracts of BRL-3A cells. To analysis using consensus or aberrant Sp1 elements and a polyclonal Sp1 antiserum to inhibit DNA binding were performed. These in vivo and in vitro data demonstrated that Sp1 plays an important role in the regulation of the expression of rIGFBP-2.

Sp1 interacts with the consensus sequence for Egr-1 gene product with a cellular factor(s) and activates the transcription through this element.

We report that Sp1 from nuclear extracts of BRL-3A cells interacts with the consensus DNA sequence for the Egr-1 gene product in an overlapping manner. Purified Sp1 failed to bind to this sequence and with the addition of sub-saturating level of nuclear extracts, the binding activity appeared. In Drosophila cells (SL2), exogenously expressed Sp1 activated the transcription through the Egr-1 site. These findings suggest that Sp1 can be targeted to a non-Sp1 (Egr-1) site with a cellular factor(s) and can activate the transcription through this element.