[Cushing syndrome because of herbal supplement]. / Syndroom van Cushing door kruidenpreparaat.

The use of exogenous glucocorticoids is a common cause of Cushing syndrome. We present a case of exogenous Cushing syndrome caused by Binahong: an over-the-counter 'herbal' supplement. A 54-year-old woman presented with weight gain, joint pain, hypertension and poorly regulated type 2 diabetes mellitus despite the start of semaglutide one year before presentation. Physical examination revealed signs of steroid excess with a moon face and abdominal obesity. Her serum cortisol level and ACTH level were suppressed. Synthetic glucocorticoid screening revealed a positive dexamethason level in the herbal supplement. After stopping the supplement her serum cortisol and dexamethason increased to normal levels. This case emphasizes the importance of awareness for the use of supplements containing hidden glucocorticoids causing Cushing syndrome.

Serotonin and poor neonatal adaptation after antidepressant exposure in utero.

OBJECTIVE: Infants exposed to selective antidepressants (SADs) in utero are at risk to develop poor neonatal adaptation (PNA) postpartum. As symptoms are non-specific and the aetiology of PNA is unknown, the diagnostic process is hampered. We hypothesised that the serotonin metabolism plays a role in the aetiology of PNA. METHODS: In this controlled study, infants admitted postpartum from February 2012 to August 2013 were included and followed for 3 days. Infants exposed to SADs during at least the last 2 weeks of fetal life were included in the patient group (n=63). Infants not exposed to psychotropic medication and admitted postpartum for another reason were included in the control group (n=126). The neonatal urinary 5-hydroxyindoleacetid acid (5-HIAA) levels of SAD-exposed infants who developed PNA, SAD-exposed infants who did not develop PNA and control infants were compared. RESULTS: The course of the 5-HIAA levels over the first 3 days postpartum differed between infants with and without PNA (p≤0.001) with higher 5-HIAA levels in infants with PNA on day 1 (2.42 mmol/mol, p=0.001). Presence of maternal psychological distress modified this relationship. CONCLUSIONS: A transient disturbance of the neonatal serotonergic system may play a role in the aetiology of PNA. Other factors, including the presence of maternal psychological distress, also seem to play a role.

Identification of receptor-type protein tyrosine phosphatase µ as a new marker for osteocytes.

Osteocytes are the predominant cells in bone, where they form a cellular network and display important functions in bone homeostasis, phosphate metabolism and mechanical transduction. Several proteins strongly expressed by osteocytes are involved in these processes, e.g., sclerostin, DMP-1, PHEX, FGF23 and MEPE, while others are upregulated during differentiation of osteoblasts into osteocytes, e.g., osteocalcin and E11. The receptor-type protein tyrosine phosphatase µ (RPTPµ) has been described to be expressed in cells which display a cellular network, e.g., endothelial and neuronal cells, and is implied in mechanotransduction. In a capillary outgrowth assay using metatarsals derived from RPTPµ-knock-out/LacZ knock-in mice, we observed that the capillary structures grown out of the metatarsals were stained blue, as expected. Surprisingly, cells within the metatarsal bone tissue were positive for LacZ activity as well, indicating that RPTPµ is also expressed by osteocytes. Subsequent histochemical analysis showed that within bone, RPTPµ is expressed exclusively in early-stage osteocytes. Analysis of bone marrow cell cultures revealed that osteocytes are present in the nodules and an enzymatic assay enabled the quantification of the amount of osteocytes. No apparent bone phenotype was observed when tibiae of RPTPµ-knock-out/LacZ knock-in mice were analyzed by µCT at several time points during aging, although a significant reduction in cortical bone was observed in RPTPµ-knock-out/LacZ knock-in mice at 20 weeks. Changes in trabecular bone were more subtle. Our data show that RPTPµ is a new marker for osteocytes.

Vitamin D deficiency among native Dutch and first- and second-generation non-Western immigrants.

UNLABELLED: The aim of this study was to determine the prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency in a hospital-based population of both native Dutch and non-Western immigrants and to investigate the influence of immigrant status on the prevalence of vitamin D deficiency. A cross-sectional survey was conducted among 132 patients (1-18 years of age) visiting the paediatric outpatient department. Serum levels of 25(OH)D were measured using high-performance liquid chromatography. Cut-off levels of 30 and 50 nmol/l for serum 25(OH)D were evaluated. One third of the patients had serum 25(OH)D levels below 30 nmol/l, and half of the study population had serum levels below 50 nmol/l. Non-Western immigrants had an increased risk for vitamin D deficiency compared to their native Dutch peers [25(OH)D of <30 nmol/l, p = 0.03, odds ratio (OR) 3.87 (95 % confidence interval (CI) 1.13-13.29); 25(OH)D of <50 nmol/l, p = 0.02, OR 3.57 (95 % CI 1.26-10.14)] with the highest risk for first-generation non-Western immigrants. CONCLUSION: Vitamin D deficiency in the paediatric population is still a matter of concern in the Netherlands, in particular among first-generation non-Western immigrants. We therefore strongly recommend vitamin D supplementation for all non-Western immigrants, regardless of age, skin type or season. Health-care staff who work with non-Western immigrants should be aware of the prevalence and implications of vitamin D deficiency.

Evaluation of the Sysmex UF-1000i® urine flow cytometer in the diagnostic work-up of suspected urinary tract infection in a Dutch general hospital.

BACKGROUND: Automation and standardization of sediment analysis of urine samples by flow cytometry might serve as an alternative to labor-intensive laboratory methods, such as microscopic examination and culture. The Sysmex UF-1000i is a urine flow cytometer that uses two separate channels for counting blood cells and bacteria. METHODS: In this study, 358 urine samples were analyzed with the Sysmex UF-1000i in parallel with manual microscopy, Gram stain and bacterial culture, the latter considered the gold standard. RESULTS: Reproducibility for detection of white and red blood cells and bacteria was good, while detection of yeast proved unreliable. Depending on the definition of urinary tract infection (UTI) used, the negative predictive value and the percentage of false-negative results were 100% and 0% [UTI ≥ 10(5) colony forming units (CFU)/mL] and 99% and 1.3%, (UTI ≥ 10(4) CFU/mL), respectively. Pre-screening with the Sysmex UF-1000i would have resulted in a reduction of bacterial culture by 42%. Carry over of bacteria between consecutive samples due to the use of fixed sample needle was observed, but did not result in false-positive interpretation of Sysmex UF-1000i results. Because of the occurrence of carry over, samples that have been analyzed with the Sysmex UF-1000i cannot be used for subsequent urine culture. CONCLUSIONS: In conclusion, the Sysmex UF-1000i offers the possibility for screening high numbers of urine samples in a fast and standardized way, resulting in a reduction in workload and speeding the diagnostic process. It is not recommended for use in complicated patient populations, such as neutropenic patients and patients in whom yeast infection is suspected.

The tumor suppressor Smad4 is required for transforming growth factor beta-induced epithelial to mesenchymal transition and bone metastasis of breast cancer cells.

Transforming growth factor beta (TGF-beta) can act as suppressor and promoter of cancer progression. Intracellular Smad proteins (i.e., receptor regulated Smads and common mediator Smad4) play a pivotal role in mediating antimitogenic and proapoptotic effects of TGF-beta, but their function in TGF-beta-induced invasion and metastasis is unclear. Here, we have investigated the role of Smad4 in a cellular and mouse model for TGF-beta-induced breast cancer progression. Consistent with its tumor suppressor function, specific silencing of Smad4 in NMuMG mammary gland epithelial cells using small hairpin RNA (shRNA)-expressing RNAi vectors strongly mitigated TGF-beta-induced growth inhibition and apoptosis. Smad4 knockdown also potently inhibited TGF-beta-induced epithelial to mesenchymal transition of NMuMG cells as measured by morphologic transformation from epithelial to fibroblast-like cells, formation of stress fibers, inhibition of E-cadherin expression, and gain of expression of various mesenchymal markers. Furthermore, we show that knockdown of Smad4 in MDA-MB-231 breast cancer cells strongly inhibited the frequency of bone metastasis in nude mice by 75% and significantly increased metastasis-free survival. Communication of MDA-MB-231 cells with the bone microenvironment, which is needed for optimal tumor cell growth and metastasis, may be affected in Smad4 knockdown cells as TGF-beta-induced expression of interleukin 11 was attenuated on Smad4 knockdown. Taken together, our results show that Smad4 plays an important role in both tumor suppression and progression of breast cancer cells.

Transforming growth factor-beta signal transduction in angiogenesis and vascular disorders.

Transforming growth factor (TGF)-beta is a multifunctional protein that initiates its diverse cellular responses by binding to and activating specific type I and type II serine/threonine kinase receptors. TGF-beta can act as a regulator of proliferation, migration, survival, differentiation, and extracellular matrix synthesis in endothelial cells and vascular smooth muscle cells, as well as in the maintenance of vascular homeostasis. Importantly, genetic studies in humans have revealed the pivotal role of TGF-beta as well as its signaling components in angiogenesis. Mutations in two TGF-beta receptors (ie, the activin receptor-like kinase (ALK) 1 and the accessory TGF-beta receptor endoglin) have been linked to vascular disorders named hereditary hemorrhagic telangiectasia. In addition, knockout mice for the different components of the TGF-beta signaling pathway have shown that TGF-beta is indispensable for angiogenesis. Recent studies have revealed that TGF-beta can regulate vascular homeostasis by balancing the signaling between two distinct TGF-beta type I receptors (ie, the endothelial-restricted ALK1 and the broadly expressed ALK5 receptors). The activation of these receptors has been shown to induce opposite effects on endothelial cell behavior and angiogenesis. In this review, we will present recent advances in understanding the role of TGF-beta signaling in endothelial cells as well as the underlying molecular mechanisms by which perturbation of this pathway can lead to vascular disorders.

Endostatin's heparan sulfate-binding site is essential for inhibition of angiogenesis and enhances in situ binding to capillary-like structures in bone explants.

The functional role of endostatin's affinity for heparan sulfates was addressed using an ex vivo bone angiogenesis model. Capillary-like sprouts showed prominent expression of collagen XVIII/endostatin. Outgrowth of endothelial cells was not altered in the absence of collagen XVIII but inhibited by the addition of recombinant endostatin. Mutant non-heparan sulfate binding endostatin and the collagen XV endostatin homologue were ineffective. The ability of mutant endostatin to bind to capillary structures was reduced when compared to endostatin. Endostatin-XV completely failed to bind to endothelial cells. Our data indicate that endostatin's angiostatic function is heparan sulfate-dependent, and that in situ-binding of endostatin to endothelial cells is increased by heparan sulfates.

TGF-beta receptor function in the endothelium.

Genetic studies in mice and humans have revealed the pivotal role of transforming growth factor-beta (TGF-beta) signaling during angiogenesis. Mice deficient for various TGF-beta signaling components present an embryonic lethality due to vascular defects. In patients, mutations in the TGF-beta type I receptor ALK1 or in the accessory TGF-beta receptor endoglin are linked to an autosomal dominant disorder of vascular dysplasia termed Hereditary Haemorrhagic Telangiectasia (HHT). It has puzzled researchers for years to explain the effects of TGF-beta being a stimulator and an inhibitor of angiogenesis in vitro and in vivo. Recently, a model has been proposed in which TGF-beta by binding to the TGF-beta type II receptor can activate two distinct type I receptors in endothelial cells (ECs), i.e., the EC-restricted ALK1 and the broadly expressed ALK-5, which have opposite effects on ECs behavior. ALK1 via Smad1/5 transcription factors stimulates EC proliferation and migration, whereas ALK5 via Smad2/3 inhibits EC proliferation and migration. Here, the new findings are presented concerning the molecular mechanisms that take place in ECs to precisely regulate and even switch between TGF-beta-induced biological responses. In particular, the role of the accessory TGF-beta receptor endoglin in the regulation of EC behavior is addressed and new insights are discussed concerning the possible mechanisms that are implicated in the development of HHT.

Vascular endothelial growth factor overexpression in ischemic skeletal muscle enhances myoglobin expression in vivo.

Therapeutic angiogenesis using vascular endothelial growth factor (VEGF) is considered a promising new therapy for patients with arterial obstructive disease. Clinical improvements observed consist of improved muscle function and regression of rest pain or angina. However, direct evidence for improved vascularization, as evaluated by angiography, is weak. In this study, we report an angiogenesis-independent effect of VEGF on ischemic skeletal muscle, ie, upregulation of myoglobin after VEGF treatment. Mice received intramuscular injection with adenoviral VEGF-A or either adenoviral LacZ or PBS as control, followed by surgical induction of acute hindlimb ischemia at day 3. At day 6, capillary density was increased in calf muscle of Ad.VEGF-treated versus control mice (P<0.01). However, angiographic score of collateral arteries was unchanged between Ad.VEGF-treated and control mice. More interestingly, an increase in myoglobin was observed in Ad.VEGF-treated mice. Active myoglobin was 1.5-fold increased in calf muscle of Ad.VEGF-treated mice (P< or =0.01). In addition, the number of myoglobin-stained myofibers was 2.6-fold increased in Ad.VEGF-treated mice (P=0.001). Furthermore, in ischemic muscle of 15 limb amputation patients, VEGF and myoglobin were coexpressed. Finally, in cultured C2C12 myotubes treated with rhVEGF, myoglobin mRNA was 2.8-fold raised as compared with PBS-treated cells (P=0.02). This effect could be blocked with the VEGF receptor tyrosine kinase inhibitor SU5416. In conclusion, we show that VEGF upregulates myoglobin in ischemic muscle both in vitro and in vivo. Increased myoglobin expression in VEGF-treated muscle implies an improved muscle oxygenation, which may, at least partly, explain observed clinical improvements in VEGF-treated patients, in the absence of improved vascularization.

In vitro and in vivo endochondral bone formation models allow identification of anti-angiogenic compounds.

A major obstacle in the study of angiogenesis and the testing of new agents with anti-angiogenic potential has been the lack of experimental models with predictive in vivo value. We describe here the combined use of in vitro and in vivo angiogenesis models that are based on endochondral bone development. This approach led to the identification of a new inhibitor of matrix metalloprotease (MMP) activity that inhibits neovascularization in vitro and in vivo while osteoclast invasion, which occurs simultaneously during bone development, remained unaffected. In contrast, the broad-spectrum MMP-inhibitor marimastat inhibited both in vitro angiogenesis and osteoclastogenesis dose-dependently but displayed severe toxic side effects in vivo. The combined use of these experimental models may, therefore, facilitate the discovery of mechanisms underlying angiogenesis and lead to identification of new pharmacological compounds with clinical efficacy and appropriate selectivity in the treatment of angiogenesis-dependent disorders like arthritis and cancer.

Dissociation of angiogenesis and osteoclastogenesis during endochondral bone formation in neonatal mice.

Invasion of the mineralized matrix by endothelial cells and osteoclasts is a key event in endochondral bone formation. To examine the putative role of osteoclast activity in the angiogenic process, we used two in vivo models of suppressed bone resorption: mice treated with the bisphosphonate clodronate and in osteoclast-deficient, osteopetrotic mice. Angiogenesis was assessed in caudal vertebrae of these neonatal mice. This model enables us to study the interaction between osteoclasts and endothelial cells during endochondral bone formation. In control conditions, sinusoid-like structures were detected in the vicinity of tartrate resistance acid phosphatase positive (TRAcP+) osteoclasts. Treatment with clodronate completely abolished osteoclastic bone resorption, whereas angiogenesis remained unaffected. In line with these observations, in the osteopetrotic mouse mutants c-fos knockout mice and op/op mice, capillaries invaded the calcified cartilage in the absence of osteoclasts. In conclusion, our data strongly suggest that during endochondral bone formation, vascular invasion can occur in the absence of osteo(chondro)clastic resorption. In addition, bisphosphonates show no apparent effect on angiogenesis in this in vivo model. These findings may have important clinical implications in the management of skeletal disorders such as metastatic bone disease, in which both osteoclastic bone resorption and angiogenesis contribute to tumor growth. On the other hand, our results confirm that bisphosphonates can be used safely in the treatment of disorders that affect the growing skeleton, such as in juvenile osteoporosis.

Design of a variant of vascular endothelial growth factor-A (VEGF-A) antagonizing KDR/Flk-1 and Flt-1.

Because of its central role in pathological angiogenesis, vascular endothelial growth factor (VEGF) has become a major target for anti-angiogenic therapies. We report here the construction of a heterodimeric antagonistic VEGF variant (HD-VEGF). In this antagonist, binding domains for the VEGF-receptors KDR/Flk-1 and Flt-1 are present at one pole of the dimer, whereas the other pole carries domain swap mutations, which prevent binding to either receptor. As HD-VEGF can only bind to monomeric receptors, it does not lead to signal transduction. Moreover, it antagonizes VEGF and possibly other members of the VEGF family, which are KDR/Flk-1 and Flt-1 ligands. We show here that HD-VEGF is a potent inhibitor of VEGF-mediated proliferation and tissue factor induction in endothelial cell cultures, requiring only a 20-fold and a 4-fold excess, respectively, to block the activity of wtVEGF completely. A 4-fold excess of HD-VEGF over wtVEGF was also sufficient to abrogate vascular permeability as determined in the Miles assay in vivo. Furthermore, HD-VEGF inhibited fetal bone angiogenesis in an ex vivo assay. Thus, HD-VEGF blocks KDR- and Flt-1-mediated VEGF activities that are crucial in the angiogenic process and is therefore a promising, multipotent compound in the treatment of angiogenesis-related diseases.

Bone morphogenetic proteins stimulate angiogenesis through osteoblast-derived vascular endothelial growth factor A.

During bone formation and fracture healing there is a cross-talk between endothelial cells and osteoblasts. We previously showed that vascular endothelial growth factor A (VEGF-A) might be an important factor in this cross-talk, as osteoblast-like cells produce this angiogenic factor in a differentiation-dependent manner. Moreover, exogenously added VEGF-A enhances osteoblast differentiation. In the present study we investigated, given the coupling between angiogenesis and bone formation, whether bone morphogenetic proteins (BMPs) stimulate osteoblastogenesis and angiogenesis through the production of VEGF-A. For this we used the murine preosteoblast-like cell line KS483, which forms mineralized nodules in vitro, and an angiogenesis assay comprising 17-d-old fetal mouse bone explants that have the ability to form tube-like structures in vitro. Treatment of KS483 cells with BMP-2, -4, and -6 enhanced nodule formation, osteocalcin mRNA expression, and subsequent mineralization after 18 d of culture. This was accompanied by a dose-dependent increase in VEGF-A protein levels throughout the culture period. BMP-induced osteoblast differentiation, however, was independent of VEGF-A, as blocking VEGF-A activity by a VEGF-A antibody or a VEGF receptor 2 tyrosine kinase inhibitor did not affect BMP-induced mineralization. To investigate whether BMPs stimulate angiogenesis through VEGF-A, BMPs were assayed for their angiogenic activity. Treatment of bone explants with BMPs enhanced angiogenesis. This was inhibited by soluble BMP receptor 1A or noggin. In the presence of a VEGF-A antibody, both unstimulated and BMP-stimulated angiogenesis were arrested. Conditioned media of KS483 cells treated with BMPs also induced a strong angiogenic response, which was blocked by antimouse VEGF-A but not by noggin. These effects were specific for BMPs, as TGF beta inhibited osteoblast differentiation and angiogenesis while stimulating VEGF-A production. These findings indicate that BMPs stimulate angiogenesis through the production of VEGF-A by osteoblasts. In conclusion, VEGF-A produced by osteoblasts in response to BMPs is not involved in osteoblast differentiation, but couples angiogenesis to bone formation.