[Cologne Statement for Medical Care of Refugees]. / Kölner Statement zur medizinischen Versorgung von Flüchtlingen.

The Cologne statement resulted from both regional and nationwide controversial discussions about meaning and purpose of an initial examination for infectious diseases of refugees with respect to limited time, personnel and financial resources. Refugees per se are no increased infection risk factors for the general population as well as aiders, when the aiders comply with general hygiene rules and are vaccinated according to the recommendations of the German Standing Committee on Vaccination (STIKO). This is supported by our own data. Based on individual medical history, refugees need medical care, which is offered purposeful, economic, humanitarian and ethical. In addition to medical confidentiality, the reporting obligation according § 34 Infection Protection Act (IPA) and the examination concerning infectious pulmonary tuberculosis according to § 36 (4) IPA must be considered.

Leptin does not induce an inflammatory response in the murine placenta.

Leptin is described as a pro-inflammatory signal in fat tissue, which is released from adipocytes and in turn activates immune cells. Also, leptin levels are known to be increased in pregnancies complicated with enhanced inflammatory processes in the placenta. Hence, we assumed that increased leptin amounts might contribute to inducing an inflammatory response in the placenta. To test this hypothesis, pregnant mice were continuously infused with recombinant murine leptin s. c. from day g13 to g16, resulting in a 3-fold increase of maternal circulating serum leptin levels. Dissected placentas were examined for the expression of pro-inflammatory cytokines IL-6 and TNF-alpha and the anti-inflammatory cytokine IL-10 using qPCR analysis. No changes were found except for TNF-alpha, which was slightly elevated upon leptin stimulation. However, TNF-alpha protein levels were not significantly higher in placentas from leptin treated mice. Also, leukocyte infiltration in the labyrinth section of placentas was not increased. In summary, our data demonstrate for the first time that elevated leptin levels alone do not induce an inflammatory response in the placenta.

Two cases of lupus vulgaris in childhood and review of the clinical challenges.

BACKGROUND: Lupus vulgaris (LV) is the most common form of cutaneous tuberculosis (TB) in Europe, nevertheless the overall incidence is low. It constitutes about 1.5% of all extra-pulmonary cases worldwide. A slight raise in TB incidence rates among children was recently registered in Germany, which can be explained by the increased immigration. PATIENTS AND METHODS: We present 2 cases of immigrated children who were diagnosed with Lupus vulagris, both clinically and histopathologically. Although the symptoms and the duration of the skin lesions were very different, both patients had a non-healing skin ulceration.In our cases cultures of the skin biopsy were positive for Mycobacterium tuberculosis and the lesions showed marked improvement in response to antituberculous treatment. In the first patient, it took 6 years between occurrence of skin lesions and final diagnosis. The second patient had an extracutaneous focus, namely abdominal TB. CONCLUSION: We report our experience and emphasize on recent advances in the diagnosis and treatment of paediatric skin TB.

[Diagnostics, clinical aspects and genetics of congenital corneal opacities]. / Diagnostik, Klinik und Genetik kongenitaler Hornhauttrübungen.

BACKGROUND: Congenital corneal opacities are comparatively rare diseases with high amblyogenic potential. PURPOSE: The present work provides an overview of the diagnostics, clinical aspects and genetics of congenital corneal opacities. METHODS: A literature search was carried out to compile an overview and illustration with own clinical case examples. RESULTS: Differentiated diagnostics are of high importance in the treatment of patients with congenital corneal opacities. A close cooperation between the medical departments involved and also the parents is absolutely essential. The structured classification of congenital corneal opacities provides the basis for a targeted treatment. DISCUSSION: The causes and the clinical symptoms of congenital corneal opacities are manifold. The correct diagnosis should be made early and in an interdisciplinary manner. Based on this, conservative and surgical treatment measures can be planned and an impending development of amblyopia can be specifically counteracted.

Correlations between high level sport-climbing and the development of adolescents.

Over the last years concerns have been raised about the health effects particularly on young climbers due to the observation of short stature with low body weight and body fat in sports climbers. The aim of this study was to investigate anthropometric and hormonal data for climbers of the German Junior national team. 16 climbers were compared with 14-age matched nonclimbers with respect to several anthropometric variables, leptin level, and climbing characteristics. Height, weight and body mass index (BMI) standard deviation scores (SDS) for boys were not significantly different from the controls, whereas girls had significantly lower SDS-values for weight and BMI. In comparison with the control group boys and girls had a lower skinfold thickness. The leptin values were lower than the calculated leptin levels but only reached significance for the girls. The young athletes of the GJNT were neither of short stature nor thin when compared with a physically active control group. The low body fat in boys and girls was within expected limits. The lower leptin levels might be attributed to a decrease in total body fat.

Microarray analysis of placental tissue in intrauterine growth restriction.

OBJECTIVE: Besides foetal or maternal disorders, placental dysfunction is a major cause of intrauterine growth restriction (IUGR). Although numerous macro- and histopathological changes have been described, little is known about the precise aetiology and the contribution of foetal/placental genes in this disorder. DESIGN: Placental tissues of 20 IUGR and control neonates were analysed by microarray technique. Four of the regulated genes with possible relevance in the pathogenesis of IUGR and its consequences were further studied in placentas of 27 IUGR and 35 control newborns. RESULTS: Elevated gene expression of leptin, corticotrophin-releasing hormone (CRH), and IGF-binding protein-1 (IGFBP-1) in IUGR placentas could be confirmed in the larger group by real-time PCR, whereas prolactin showed no significant difference. Accordingly, protein expression of leptin and IGFBP-1 depicted by Western blot was elevated in IUGR, prolactin was not different. Birthweight standard deviation score (SDS) correlated negatively to leptin, IGFBP-1, and CRH, whereas placental weight correlated only to IGFBP-1. Leptin correlated negatively to gestational age of IUGR patients and positively to placental score, a marker of severity of impaired foeto-placental circulation. CONCLUSIONS: As confirmed in a large group of IUGR and control samples, the up-regulated factors leptin, IGFBP-1, and CRH may serve as candidate genes for the prediction of subsequent metabolic consequences in IUGR newborns. These three factors may not only influence growth of the foetus, but might also interact with programming of its metabolic functions, which has to be determined in an ongoing study.

Early weight gain and outcome in Henoch-Schönlein nephritis.

BACKGROUND: Intrauterine growth restriction seems to be a risk factor for an aggravated course of secondary renal diseases in children. Catch-up growth after birth may play a critical role. We tested if there is an association between an aggravated course of nephritis in Henoch-Schönlein Purpura (PSHN) and low birth weight or early weight gain during infancy. PATIENTS: We retrospectively analysed the clinical course of 34 children with PSHN. METHODS: Patients were sorted according their birth weight standard deviation score (SDS) in tertiles. Early weight gain was defined as gain of weight standard deviation score >0.67 between birth and 2 years of age. RESULTS: Patients with higher birth weight needed Cyclophosphamide in a higher rate than low birth weight children. In the high weight gain group (SDS gain >0.67) 9 of the 11 patients compared to 7 of 22 patients in the low weight gain group (SDS gain <0.67) presented with arterial hypertension during the initial manifestation of PSH nephritis (p=0.01). Median systolic blood pressure SDS in the high weight gain group was 1.54 (-1.39-4.71) versus 0.29 (0.52-4.05) in the low weight gain group (p=0.008). Nevertheless, other clinical parameters during first manifestation and follow-up were not relevantly different. CONCLUSION: In contrast to the data of children with idiopathic nephrotic syndrome or IgA nephropathy, this study does neither provide evidence for an association between low birth weight nor early weight gain and the later course of PSHN. Interestingly, early weight gain was associated with a higher systolic blood pressure during the initial manifestation of PSHN.

Considering laparoscopic salvage options--is pre-emptive omentectomy necessary in paediatric peritoneal patients?

BACKGROUND: In paediatric peritoneal dialysis patients, pre-emptive omentectomy is discussed controversially and literature provides only little data concerning this issue. Our aim was to evaluate the rate of omentum-majus-related problems in our patients, in whom omentectomy was generally not performed. Furthermore, we were interested in the success rates of laparoscopic adhesiolysis. PATIENTS AND METHODS: Between 09/2006 and 03/2008, we regularly saw 18 peritoneal dialysis patients in whom we retrospectively analysed medical records to determine the rate of catheter-related complications. In addition, we evaluated the success rates of laparoscopic adhesiolysis. RESULTS: During 355 dialysis months in 18 patients, we observed 7 omentum-majus-related obstructions in 6 patients (1/50.7 PM). The median age of the patients affected was 9 years, median filling volume at the time of the obstruction was 671 ml/m (2). Laparoscopic adhesiolysis was successful in 4 out of 7 episodes. In 3 cases, the catheter lumen was plugged by necrotic portions of the omentum and the catheters had to be replaced. CONCLUSION: Our data confirm omentum-majus-related catheter obstruction as a major cause of catheter dysfunction. However, in comparison to literature, it remains unclear to which extent omentectomy can reduce the incidence of catheter obstruction in general (including e. g. obstruction due to coagulation). Thus, the decision to perform an omentectomy should be taken individually after careful consideration. In case of omentum-majus-associated obstruction, early but not late laparoscopic intervention proved to be a successful, minimally invasive technique to restore catheter function.

[Benefits and risks of tube feeding via gastrostoma in infants and children with peritoneal dialysis]. / Nutzen und Risiko eines Gastrostomas bei Säuglingen und Kleinkindern mit chronischer Peritonealdialyse.

BACKGROUND: Nutrition of children with end-stage renal disease and peritoneal dialysis (PD) is often difficult. Tube feeding via a gastrostoma is discussed controversially, and some authors consider this as a contraindication because of the risk of peritonitis. METHODS: In our centre 16 infants and children with end-stage renal disease were treated with PD and tube feeding over a gastrostoma in the last 12 years. The patients showed dystrophy (mean BMI -1.73 SDS) and were too small (mean body length -4.56 SDS). Seven of them (median age 11 months) received a gastrostoma before insertion of a Tenkhoff-catheter and start of PD. Nine children (median age 5 months) had PD primarily before insertion of the gastrostoma and start of tube feeding. RESULTS: Patients with start of PD while a gastrostoma was already inserted had 15 events with peritonitis in the observation time of 91 months (1.98 per patient year). Patients with primary start of PD had 12 events with peritonitis in a total time of 43 month (3.34 per patient year), after insertion while PD was already running the number of events fell significantly to 25 peritonitis events in a total of 271 months (1.11 per patient year, p < 0.01). The children had a benefit from tube feeding via a gastrostoma in regard of body weight (BMI + 1.61 SDS, p < 0.01) as well as growth (body height + 2.29 SDS, p < 0.05). CONCLUSION: Tube feeding via a gastrostoma is a good and safe option for alimentation, even under peritoneal dialysis. A decrease of PD-associated peritonitis under tube feeding was observed while physical development was positively influenced.

Experience with mycophenolate mofetil as maintenance therapy in five pediatric patients with severe systemic lupus erythematosus.

Maintenance therapy of severe pediatric systemic lupus erythematosus (SLE) usually consists of azathioprine and prednisone . In adult SLE patients mycophenolate mofetil (MMF) is successfully used, superiority to azathioprine has not been shown yet. We hypothesized that a maintenance therapy with MMF is able to decrease disease activity as well as the dose of glucocorticoid needed in children and adolescents with SLE. Five girls with a mean age of 13.9 (range 12-15) years were treated with 1.2+/-0.20 g/m (2) MMF daily on individual medical decision. Three patients had severe renal (WHO IV) and one severe cerebral involvement. Three patients with frequent flares on azathioprine maintenance therapy were switched to MMF, two patients with severe renal and cerebral manifestation received MMF additionally after induction therapy. Flares, steroid dosage, and disease activity (SLEDAI) were monthly registered in all patients. The number of flares decreased from 1.28 to 0.25 episodes per patient year during a mean follow-up period of 39 (range 36-42) months after MMF initiation. In parallel prednisone dose could be reduced from 10.80+/-5.25 to 3.25+1.18 mg/d (p<0.01). SLEDAI score dropped from 15.20+/-2.8 before MMF to 3.60+/- 0.9 at the last visit under MMF (p<0.001). No severe adverse event occurred. In our cohort of five pediatric patients MMF was effective and safe for maintenance therapy of SLE over a period of 3.5 years. MMF seems to be successful in preventing flares even in adolescents having unfavorable course on azathioprine treatment before. This observation should be confirmed by a randomized multicenter clinical trial.

Syncytin-1 and glial cells missing a: hypoxia-induced deregulated gene expression along with disordered cell fusion in primary term human trophoblasts.

BACKGROUND/AIMS: Pre-eclampsia, a major cause of perinatal morbidity, is characterized by alterations in placental oxygen availability and trophoblast differentiation. We investigated how different levels of hypoxia alter the expression of syncytin-1, glial cells missing a (GCMa) and syncytin-1 receptor ASCT2 and affect syncytialization in primary term human trophoblasts. METHODS: Cells were incubated at 1, 3, 6 and 21% O(2) for 24, 48 and 72 h with or without cyclic adenosine monophosphate (cAMP). Gene expression was analyzed by real-time PCR. Syncytialization was assessed using beta-human chorionic gonadotropin measurement and desmoplakin immunostaining. RESULTS: Following incubation with cAMP at 21% O(2), peak gene expression of syncytin-1 and GCMa was found after 24 h along with syncytium formation at 72 h. Conversely, incubation at 1% O(2) led to a time-dependent reduction of GCMa and syncytin-1 at the transcriptional level. Cell fusion occurred at 21 and 6% O(2) and was suppressed at 1% O(2). ASCT2 mRNA levels were preserved at normoxia and downregulated at 1% O(2) after 48 h. CONCLUSION: Our data support the premise that the expression of GCMa and syncytin-1 precedes syncytialization of trophoblasts, e.g. at 6% O(2), which is assumed to resemble physiological conditions. Severe hypoxia is associated with reduced GCMa and syncytin-1 transcripts and altered fusion of primary trophoblasts.

Exercise during pregnancy and its impact on mothers and offspring in humans and mice.

Exercise during pregnancy has beneficial effects on maternal and offspring's health in humans and mice. The underlying mechanisms remain unclear. This comparative study aimed to determine the long-term effects of an exercise program on metabolism, weight gain, body composition and changes in hormones [insulin, leptin, brain-derived neurotrophic factor (BDNF)]. Pregnant women (n=34) and mouse dams (n=44) were subjected to an exercise program compared with matched controls (period I). Follow-up in the offspring was performed over 6 months in humans, corresponding to postnatal day (P) 21 in mice (period II). Half of the mouse offspring was challenged with a high-fat diet (HFD) for 6 weeks between P70 and P112 (period III). In period I, exercise during pregnancy led to 6% lower fat content, 40% lower leptin levels and an increase of 50% BDNF levels in humans compared with controls, which was not observed in mice. After period II in humans and mice, offspring body weight did not differ from that of the controls. Further differences were observed in period III. Offspring of exercising mouse dams had significantly lower fat mass and leptin levels compared with controls. In addition, at P112, BDNF levels in offspring were significantly higher from exercising mothers while this effect was completely blunted by HFD feeding. In this study, we found comparable effects on maternal and offspring's weight gain in humans and mice but different effects in insulin, leptin and BDNF. The long-term potential protective effects of exercise on biomarkers should be examined in human studies.

Patient with antibody-negative relapse of Goodpasture syndrome.

Smoking in young men may trigger anti-GBM disease manifesting with hemoptysis. We present a male adolescent in whom hemoptysis was mistaken to be a sign of airway infection for several months and who later on underwent an unusual antibody-negative relapse. The 16-year-old patient had a history of smoking and therapy-refractant hemoptysis and, later, acute macrohematuria with renal insufficiency necessitating hemodialysis (initial creatinine 4.2 mg/ dl). Chest X-ray showed diffuse lung infiltration. Renal biopsy revealed linear IgG deposits along the glomerular basement membrane (GBM) and cellular crescents in 13/16 glomeruli, simultaneously increased anti-GBM antibodies were detected. Thus, anti-GBM glomerulonephritis was diagnosed. After treatment with prednisone, oral cyclophosphamide and plasmapheresis, chest X-ray and hemoptysis improved, but renal failure persisted. Anti-GBM antibodies were negative. 4 weeks later, the patient presented again with a clinical relapse of severe hemoptysis and respiratory insufficiency after smoke exposition. Despite negative anti-GBM antibodies, he was treated similarly to a relapse and after the second course of plasmapheresis the patients' general condition improved and hemoptysis subsided. During the next 10 months the patient was stable with negative antibodies. He was under intermittent hemodialysis until laboratory measurements showed improved renal function. Now, 30 months after the acute episode, the patient is off dialysis for 17 months with stable creatinine values of 1.9 - 2.4 mg/dl, and is currently being treated with antihypertensive medicaments, calcitriol, calciumacetate, natriumhydrogencarbonate and allopurinol. The prognosis of anti-GBM glomerulonephritis depends on serum creatinine and the need of dialysis at initial presentation. In these patients, one-year survival rate is 67% and 5% for kidney function. Of note, despite the unfavorable prognosis in our patient, renal function recovered after 1 year of hemodialysis treatment. It is important to consider that in patients with anti-GBM disease antibody-negative relapses are possible.

Metabolic decompensation in children with type 1 diabetes mellitus associated with increased serum levels of the soluble leptin receptor.

OBJECTIVE: Type 1 diabetes mellitus (T1DM) leads to increased serum levels of the soluble leptin receptor (sOB-R) by an as yet unknown cellular mechanism. The aim of our study was to investigate potential metabolic factors that may be associated with the induction of the sOB-R release from its membrane receptor. MATERIALS AND METHODS: Twenty-five children (aged between 1.5 and 17.0 years) were studied at the onset of T1DM. Blood samples were collected before (n = 25), during the first 18 h (mean +/- S.D. 11.1 +/- 4.3 h, n = 16) and 92 h (47.5 +/- 22.5 h; n = 14) after beginning insulin therapy. Serum sOB-R and leptin levels were determined by in-house immunoassays. RESULTS: The sOBR-level and the molar sOB-R/leptin ratio were significantly higher before than after starting insulin treatment (P < 0.05). In contrast, leptin levels were significantly lower (P < 0.05) before insulin therapy. The correlation between sOB-R and blood glucose (r = 0.49; P < 0.05), as well as sOB-R with parameters of ketoacidosis, such as pH (r = -0.72), base excess (r = -0.70), and bicarbonate (r = -0.69) (P < 0.0001) at diagnosis of T1DM remained significant during the first 18 h of insulin treatment. Multiple regression analysis revealed that base excess predicted 41.0% (P < 0.001), age 16.4% (P < 0.05), and height SDS 13.9% (P < 0.01) of the sOB-R variance. CONCLUSIONS: Metabolic decompensation in children with new onset T1DM is associated with dramatic changes of the leptin axis; serum levels of sOB-R are elevated and of leptin are reduced. The molar excess of sOB-R over leptin (median 11.3) in this condition may contribute to leptin insensitivity. Upregulation of the soluble leptin receptor appears to be a basic mechanism to compensate for intracellular substrate deficiency and energy-deprivation state.

Absence of exercise-induced leptin suppression associated with insufficient epinephrine reserve in patients with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

OBJECTIVE: Patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency suffer from glucocorticoid and mineralocorticoid deficiency. They have insufficient epinephrine reserves and increased basal leptin levels and are often insulin resistant. In healthy subjects, an inhibitory effect of acute catecholamine elevation on the leptin plasma concentrations has been reported. However, it is not yet known how leptin levels respond to exercise in CAH patients. METHODS: We performed a cycle ergometer test in six CAH patients to measure the response of plasma leptin, glucose and the catecholamines, epinephrine (E) and norepinephrine (N), as well as their respective metabolites, metanephrine (M) and normetanephrine (NM), to intense exercise. RESULTS: Baseline leptin concentrations in CAH patients were not different from those of controls. Leptin levels decreased significantly with exercise in healthy controls, whereas they remained unchanged in CAH patients. In contrast to controls, CAH patients showed no rise of plasma glucose. Basal and stimulated E and M levels were significantly lower in CAH patients compared to controls. Baseline and stimulated N and NM levels were comparable, showing a significant rise after exercise. Peak systolic blood pressure and peak heart rate in both groups were comparable. CONCLUSION: CAH patients do not manifest exercise-induced leptin suppression. The most probable reason for this is their severely impaired epinephrine stress response. In addition, epinephrine deficiency is leading to secondary changes in various catecholamine dependent metabolic pathways, e. g., energy balance. Although obvious clinical sequelae are so far unknown, the catecholamine-deficient state and the resulting hyperleptinemia might contribute to the severity of the disease in CAH.

Salivary leptin induces increased expression of growth factors in oral keratinocytes.

We investigated the influence of salivary leptin, purified by affinity chromatography, on the proliferation of human oral keratinocytes. Furthermore we determined the time- and dose-dependency of the incubation with salivary leptin on the production of epidermal growth factor (EGF) and keratinocyte growth factor (KGF), which are growth factors relevant to keratinocyte proliferation. The analysis was performed both intra- and extracellularly. The relationship between the three cytokines in cell proliferation was studied by successive blocking with specific antibodies. The incubation of oral keratinocytes with recombinant and native leptin led to a significantly increased, dose-dependent cell proliferation (P<0.001). A further significant increase in proliferation was observed after incubating the cells with sterile filtered saliva (P<0.001). The increase in proliferation could not be observed by simultaneous incubation with salivary leptin and specific antibodies against either leptin or KGF (P<0.001). We found a significant dose-dependency between leptin incubation and production of KGF and EGF at the RNA and protein level. Both cytokines were expressed intracellularly and released into the culture medium, where they could be quantified by ELISA. Furthermore, there was a dose- and time-dependent increase in the phosphorylation of STAT-1 and STAT-3, indicating that Ob-R(b) (the long form of the leptin receptor) expressed by the keratinocytes is functional. It is conceivable that the leptin-induced proliferation in keratinocytes is mediated by this signalling pathway. This is the first study to show a physiological role of salivary leptin as a growth factor for keratinocyte proliferation in the oral cavity. We could demonstrate its influence on the production of other growth factors essential for this proliferative effect. Based on the findings of our study we assume an important role for salivary leptin in wound healing within the vulnerable oral cavity.

[Denys-Drash syndrome. Experience gathered in Erlangen illustrated by two case reports]. / Denys-Drash-Syndrom. Erlanger Erfahrungen am Beispiel zweier Fallberichte.

Denys-Drash syndrome is a rare symptom complex associated with obligatory childhood nephrotic syndrome, male pseudohermaphroditism, and Wilms' tumor. The etiology of Denys-Drash syndrome is attributed to a mutation of the WT1 gene. We report on two cases of Deny-Drash syndrome confirmed by genetic testing. Rapidly evolving terminal renal insufficiency was detected in both patients necessitating bilateral nephrectomies with prophylactic intent. In one of the patients, a Wilms' tumor had already been verified in one kidney so that chemotherapy had to be initiated.The risk of Wilms' tumor is very high in patients with a WT1 mutation, which leads to the need for removal of both kidneys during or before transplantation. It would be important to perform a diagnostic work-up for WT1 gene mutation in children who develop renal failure in the 1st year of life.

Strong hypoxia reduces leptin synthesis in purified primary human trophoblasts.

INTRODUCTION: Oxygen availability severely affects placental function. During placental hypoxia, stabilization of hypoxia inducible factors (HIFs) affects transcription, and leptin gene expression concomitantly increases in vivo and in vitro. However, a causal relationship is uncertain. METHODS: We investigated the effect of oxygen availability on HIF-1 alpha (HIF1A) and leptin regulation in primary human trophoblasts isolated from six normal term placentae cultured at 0.1%, 1%, 3%, and 8% oxygen for 6 h, 24 h and 48 h. Gene expressions of leptin (LEP), leptin receptors (LEPR), HIF1A, insulin receptor (INSR) and further genes relevant in hypoxia (VEGFA, EPO, NOS2) or apoptosis (BCL2, BAX, Tp53) were examined. Leptin, HIF1A, INSR, phospho-AKT/AKT (insulin receptor signaling), caspase 3 and cleaved caspase 3 (apoptosis) proteins were measured. RESULTS: A hypoxic reaction with stabilization of HIF1A protein as well as up-regulation of HIF1A and VEGFA gene expressions, but without any hint for apoptosis, was present at 0.1% and 1% oxygen. However, leptin protein concentration (cell supernatants) peaked at 8% oxygen (normoxia) and was significantly reduced at 0.1% oxygen. There was no significant correlation between leptin and HIF1A, neither on the gene nor on the protein level. DISCUSSION: Elevated leptin gene expression in hypoxic placentas may not originate from trophoblasts, but from other placental cells, or from interaction of trophoblasts with other cells. Not only fetal hyperleptinemia, but also fetal hypoleptinemia under hypoxic conditions is conceivable. Strategies to prevent leptin dysregulation during pregnancy should be elucidated to protect the offspring from fetal programming of leptin resistance and adiposity in later life.

The placental mTOR-pathway: correlation with early growth trajectories following intrauterine growth restriction?

Idiopathic intrauterine growth restriction (IUGR) is a result of impaired placental nutrient supply. Newborns with IUGR exhibiting postnatal catch-up growth are of higher risk for cardiovascular and metabolic co-morbidities in adult life. Mammalian target of rapamycin (mTOR) was recently shown to function as a placental nutrient sensor. Thus, we determined possible correlations of members of the placental mTOR signaling cascade with auxologic parameters of postnatal growth. The protein expression and activity of mTOR-pathway signaling components, Akt, AMP-activated protein kinase α, mTOR, p70S6kinase1 and insulin receptor substrate-1 were analysed via western blotting in IUGR v. matched appropriate-for-gestational age (AGA) placentas. Moreover, mTOR was immunohistochemically stained in placental sections. Data from western blot analyses were correlated with retrospective auxological follow-up data at 1 year of age. We found significant catch-up growth in the 1st year of life in the IUGR group. MTOR and its activated form are immunohistochemically detected in multiple placental compartments. We identified correlations of placental mTOR-pathway signaling components to auxological data at birth and at 1 year of life in IUGR. Analysis of the protein expression and phosphorylation level of mTOR-pathway components in IUGR and AGA placentas postpartum, however, did not reveal pathognomonic changes. Our findings suggest that the level of activated mTOR correlates with early catch-up growth following IUGR. However, the complexity of signals converging at the mTOR nexus and its cellular distribution pattern seem to limit its potential as biomarker in this setting.

ATP concentrations in multicellular tumor spheroids assessed by single photon imaging and quantitative bioluminescence.

To evaluate the interrelationship among the cellular energy status and the development of necrosis in tumor microregions, local ATP concentrations and the extent of necrosis were determined in multicellular tumor spheroids, i.e., in spherical tumor cell aggregates. The spheroids were grown in rotated suspension cultures using EMT6 cells that were derived from a murine mammary sarcoma. The distribution of viable and necrotic cell areas was assessed by histological investigations. The regional distribution of ATP concentrations was measured with a novel technique using quantitative bioluminescence and single photon imaging. This method makes it possible to determine ATP concentrations in absolute terms with a spatial resolution at the level of a single cell. The results show that ATP concentrations in the center of EMT6 spheroids decrease from values of 1.0 to 1.5 mM in small spheroids with 300 microns in diameter to values close to or at the background level in 750 microns spheroids. Necrosis was detectable in spheroids larger than 300 microns, and virtually no spheroid without necrosis was found at sizes larger than 600 microns. Since the emergence of central necrosis precedes the drop in ATP to undetectably low values, the data suggest that energy metabolism is not or not directly involved in the development of necrosis in tumor spheroids under the growth conditions investigated.