Assessment of a one-week ketogenic diet on brain glycolytic metabolism and on the status epilepticus stage of a lithium-pilocarpine rat model

The ketogenic diet (KD) has been shown to be effective in refractory epilepsy after long-term administration. However, its interference with short-term brain metabolism and its involvement in the early process leading to epilepsy remain poorly understood. This study aimed to assess the effect of a short-term ketogenic diet on cerebral glucose metabolic changes, before and after status epilepticus (SE) in rats, by using [18F]-FDG PET. Thirty-nine rats were subjected to a one-week KD (KD-rats, n = 24) or to a standard diet (SD-rats, n = 15) before the induction of a status epilepticus (SE) by lithium-pilocarpine administrations. Brain [18F]-FDG PET scans were performed before and 4 h after this induction. Morphological MRIs were acquired and used to spatially normalize the PET images which were then analyzed voxel-wisely using a statistical parametric-based method. Twenty-six rats were analyzed (KD-rats, n = 15; SD-rats, n = 11). The 7 days of the KD were associated with significant increases in the plasma β-hydroxybutyrate level, but with an unchanged glycemia. The PET images, recorded after the KD and before SE induction, showed an increased metabolism within sites involved in the appetitive behaviors: hypothalamic areas and periaqueductal gray, whereas no area of decreased metabolism was observed. At the 4th hour following the SE induction, large metabolism increases were observed in the KD- and SD-rats in areas known to be involved in the epileptogenesis process late-i.e., the hippocampus, parahippocampic, thalamic and hypothalamic areas, the periaqueductal gray, and the limbic structures (and in the motor cortex for the KD-rats only). However, no statistically significant difference was observed when comparing SD and KD groups at the 4th hour following the SE induction. A one-week ketogenic diet does not prevent the status epilepticus (SE) and associated metabolic brain abnormalities in the lithium-pilocarpine rat model. Further explorations are needed to determine whether a significant prevention could be achieved by more prolonged ketogenic diets and by testing this diet in less severe experimental models, and moreover, to analyze the diet effects on the later and chronic stages leading to epileptogenesis.

Multi-tracer and multiparametric PET imaging to detect the IDH mutation in glioma: a preclinical translational in vitro, in vivo, and ex vivo study

Background

This translational study explores multi-tracer PET imaging for the non-invasive detection of the IDH1 mutation which is a positive prognostic factor in glioma.

Methods

U87 human high-grade glioma (HGG) isogenic cell lines with or without the IDH1 mutation (CRISP/Cas9 method) were stereotactically grafted into rat brains, and examined, in vitro, in vivo and ex vivo. PET imaging sessions, with radiotracers specific for glycolytic metabolism ([¹⁸F]FDG), amino acid metabolism ([¹⁸F]FDopa), and inflammation ([¹⁸F]DPA-714), were performed sequentially during 3–4 days. The in vitro radiotracer uptake was expressed as percent per million cells. For each radiotracer examined in vivo, static analyses included the maximal and mean tumor-to-background ratio (TBR_max and TBR_mean) and metabolic tumor volume (MTV). Dynamic analyses included the distribution volume ratio (DVR) and the relative residence time (RRT) extracted from a reference Logan model. Ex vivo analyses consisted of immunological analyses.

Results

In vitro, IDH1+ cells (i.e. cells expressing the IDH1 mutation) showed lower levels of [¹⁸F]DPA-714 uptake compared to IDH1- cells (p < 0.01). These results were confirmed in vivo with lower [¹⁸F]DPA-714 uptake in IDH+ tumors (3.90 versus 5.52 for TBR_max, p = 0.03). Different values of [¹⁸F]DPA-714 and [¹⁸F] FDopa RRT (respectively 11.07 versus 22.33 and 2.69 versus − 1.81 for IDH+ and IDH- tumors, p < 0.02) were also observed between the two types of tumors. RRT [¹⁸F]DPA-714 provided the best diagnostic performance to discriminate between the two cell lines (AUC of 100%, p < 0.01). Immuno-histological analyses revealed lower expression of Iba-1 and TSPO antibodies in IDH1+ tumors.

Conclusions

[18F]DPA-714 and [18F] FDopa both correlate with the presence of the IDH1 mutation in HGG. These radiotracers are therefore good candidates for translational studies investigating their clinical applications in patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-022-00454-6.

Synthesis of a DOTA-C-glyco bifunctional chelating agent and preliminary in vitro and in vivo study of [68Ga]Ga-DOTA-C-glyco-RGD

The design of bifunctional chelating agents (BFCA) allowing straightforward radiometal labelling of biomolecules is a current challenge. We report herein the development of a bifunctional chelating agent based on a DOTA chelator linked to a C-glycosyl compound, taking advantage of the robustness and hydrophilicity of this type of carbohydrate derivative. This new BFCA was coupled with success by CuAAC with c(RGDfK) for α_vβ₃ integrin targeting. As attested by in vitro evaluation, the conjugate DOTA-C-glyco-c(RGDfC) demonstrated high affinity for α_vβ₃ integrins (IC₅₀ of 42 nM). [⁶⁸Ga]Ga-DOTA-C-glyco-c(RGDfK) was radiosynthesized straightforwardly and showed high hydrophilic property (log D_7.4 = −3.71) and in vitro stability (>120 min). Preliminary in vivo PET study of U87MG engrafted mice gave evidence of an interesting tumor-to-non-target area ratio. All these data indicate that [⁶⁸Ga]Ga-DOTA-C-glyco-c(RGDfK) allows monitoring of α_vβ₃ expression and could thus be used for cancer diagnosis. The DOTA-C-glycoside BFCA reported here could also be used with various ligands and chelating other (radio)metals opening a broad scope of applications in imaging modalities and therapy.

A carbohydrate containing [⁶⁸Ga]Ga-DOTA-RGD tracer was designed and demonstrated promising results for cancer diagnosis by positron emission tomography imaging.

Modulation of Notch1 signaling regulates bone fracture healing

Fracture healing involves interactions of different cell types, driven by various growth factors, and signaling cascades. Periosteal mesenchymal progenitor cells give rise to the majority of osteoblasts and chondrocytes in a fracture callus. Notch signaling has emerged as an important regulator of skeletal cell proliferation and differentiation. We investigated the effects of Notch signaling during the fracture healing process. Increased Notch signaling in osteochondroprogenitor cells driven by overexpression of Notch1 intracellular domain (NICD1) (αSMACreERT2 mice crossed with Rosa-NICD1) during fracture resulted in less cartilage, more mineralized callus tissue, and stronger and stiffer bones after 3 weeks. Periosteal cells overexpressing NICD1 showed increased proliferation and migration in vitro. In vivo data confirmed that increased Notch1 signaling caused expansion of alpha-smooth muscle actin (αSMA)-positive cells and their progeny including αSMA-derived osteoblasts in the callus without affecting osteoclast numbers. In contrast, anti-NRR1 antibody treatment to inhibit Notch1 signaling resulted in increased callus cartilage area, reduced callus bone mass, and reduced biomechanical strength. Our study shows a positive effect of induced Notch1 signaling on the fracture healing process, suggesting that stimulating the Notch pathway could be beneficial for fracture repair.

Osteoclasts Derive Predominantly from Bone Marrow-Resident CX3CR1+ Precursor Cells in Homeostasis, whereas Circulating CX3CR1+ Cells Contribute to Osteoclast Development during Fracture Repair

Osteoclasts (OC) originate from either bone marrow (BM)-resident or circulating myeloid OC progenitors (OCP) expressing the receptor CX₃CR1. Multiple lines of evidence argue that OCP in homeostasis and inflammation differ. We investigated the relative contributions of BM-resident and circulating OCP to osteoclastogenesis during homeostasis and fracture repair. Using CX₃CR1-EGFP/TRAP tdTomato mice, we found CX₃CR1 expression in mononuclear cells, but not in multinucleated TRAP⁺ OC. However, CX₃CR1-expressing cells generated TRAP⁺ OC on bone within 5 d in CX₃CR1CreERT2/Ai14 tdTomato reporter mice. To define the role that circulating cells play in osteoclastogenesis during homeostasis, we parabiosed TRAP tdTomato mice (CD45.2) on a C57BL/6 background with wild-type (WT) mice (CD45.1). Flow cytometry (CD45.1/45.2) demonstrated abundant blood cell mixing between parabionts after 2 wk. At 4 wk, there were numerous tdTomato⁺ OC in the femurs of TRAP tdTomato mice but almost none in WT mice. Similarly, cultured BM stimulated to form OC demonstrated multiple fluorescent OC in cell cultures from TRAP tdTomato mice, but not from WT mice. Finally, flow cytometry confirmed low-level engraftment of BM cells between parabionts but significant engraftment in the spleens. In contrast, during fracture repair, we found that circulating CX₃CR1⁺ cells migrated to bone, lost expression of CX₃CR1, and became OC. These data demonstrate that OCP, but not mature OC, express CX₃CR1 during both homeostasis and fracture repair. We conclude that, in homeostasis mature OC derive predominantly from BM-resident OCP, whereas during fracture repair, circulating CX₃CR1⁺ cells can become OC.

Splenomegaly, myeloid lineage expansion and increased osteoclastogenesis in osteogenesis imperfecta murine

Osteogenesis imperfecta (OI) is a disease caused by defects in type I collagen production that results in brittle bones. While the pathology is mainly caused by defects in the osteoblast lineage, there is also elevated bone resorption by osteoclasts resulting in high bone turnover in severe forms of the disease. Osteoclasts originate from hematopoietic myeloid cells, however changes in hematopoiesis have not been previously documented in OI. In this study, we evaluated hematopoietic lineage distribution and osteoclast progenitor cell frequency in bone marrow, spleen and peripheral blood of osteogenesis imperfecta murine (OIM) mice, a model of severe OI. We found splenomegaly in all ages examined, and expansion of myeloid lineage cells (CD11b⁺) in bone marrow and spleen of 7-9week old male OIM animals. OIM spleens also showed an increased frequency of purified osteoclast progenitors. This phenotype is suggestive of chronic inflammation. Isolated osteoclast precursors from both spleen and bone marrow formed osteoclasts more rapidly than wild-type controls. We found that serum TNFα levels were increased in OIM, as was IL1α in OIM females. We targeted inflammation therapeutically by treating growing animals with murine TNFR2:Fc, a compound that blocks TNFα activity. Anti-TNFα treatment marginally decreased spleen mass in OIM females, but failed to reduce bone resorption, or improve bone parameters or fracture rate in OIM animals. We have demonstrated that OIM mice have changes in their hematopoietic system, and form osteoclasts more rapidly even in the absence of OI osteoblast signals, however therapy targeting TNFα did not improve disease parameters.

* Hypoxia for Mesenchymal Stem Cell Expansion and Differentiation: The Best Way for Enhancing TGFß-Induced Chondrogenesis and Preventing Calcifications in Alginate Beads

We examined the respective influence of a sequential or a continuous hypoxia during expansion and transforming growth factor beta 1-driven chondrogenic differentiation of human bone marrow mesenchymal stem cells (MSCs). The differentiation was performed within alginate beads, a classical tool for the implantation of MSCs within the joint. The standard normoxic 2D (expansion) and 3D (differentiation) MSCs cultures served as reference. To determine the quality of chondrogenesis, we analyzed typical markers such as type II and X collagens, SOX9, COMP, versican, and aggrecan mRNAs using polymerase chain reaction and we assessed the production of type II collagen and hypoxia-inducible factor (HIF)-1α by histological stainings. We simultaneously assessed the expression of osteogenic mRNAs (Alkaline Phosphatase, RUNX2, and Osteocalcin) and the presence of micro-calcifications by Alizarin red and Raman spectroscopy. Chondrogenic differentiation is clearly improved by hypoxia in 3D. Best results were obtained when the entire process, that is, 2D expansion and 3D differentiation, was performed under continuous 5% hypoxic condition. In addition, no calcification (hydroxyapatite, proved by RAMAN) was observed after 2D hypoxic expansion even in the case of a normoxic differentiation, in contrast with controls. Finally, a better chondrogenic differentiation of human MSCs is achieved when a reduced oxygen tension is applied during both expansion and differentiation times, avoiding in vitro osteogenic commitment of cells and subsequently the calcification deposition.

Visual reporters for study of the osteoblast lineage

Advancing our understanding of osteoblast biology and differentiation is critical to elucidate the pathological mechanisms responsible for skeletal diseases such as osteoporosis. Histology and histomorphometry, the classical methods to study osteoblast biology, identify osteoblasts based on their location and morphology and ability to mineralize matrix, but do not clearly define their stage of differentiation. Introduction of visual transgenes into the cells of osteoblast lineage has revolutionized the field and resulted in a paradigm shift that allowed for specific identification and isolation of subpopulations within the osteoblast lineage. Knowledge acquired from the studies based on GFP transgenes has allowed for more precise interpretation of studies analyzing targeted overexpression or deletion of genes in the osteoblast lineage. Here, we provide a condensed overview of the currently available promoter-fluorescent reporter transgenic mice that have been generated and evaluated to varying extents. We cover different stages of the lineage as transgenes have been utilized to identify osteoprogenitors, pre-osteoblasts, osteoblasts, or osteocytes. We show that each of these promoters present with advantages and disadvantages. The studies based on the use of these reporter mice have improved our understanding of bone biology. They constitute attractive models to target osteoblasts and help to understand their cell biology.

Osteogenic potential of alpha smooth muscle actin expressing muscle resident progenitor cells

Heterotopic ossification (HO) is a pathological process where bone forms in connective tissues such as skeletal muscle. Previous studies have suggested that muscle-resident non-myogenic mesenchymal progenitors are the likely source of osteoblasts and chondrocytes in HO. However, the previously identified markers of muscle-resident osteoprogenitors label up to half the osteoblasts within heterotopic lesions, suggesting other cell populations are involved. We have identified alpha smooth muscle actin (αSMA) as a marker of osteoprogenitor cells in bone and periodontium, and of osteo-chondro progenitors in the periosteum during fracture healing. We therefore utilized a lineage tracing approach to evaluate whether αSMACreERT2 identifies osteoprogenitors in the muscle. We show that in the muscle, αSMACreERT2 labels both perivascular cells, and satellite cells. αSMACre-labeled cells undergo osteogenic differentiation in vitro and form osteoblasts and chondrocytes in BMP2-induced HO in vivo. In contrast, Pax7CreERT2-labeled muscle satellite cells were restricted to myogenic differentiation in vitro, and rarely contributed to HO in vivo. Our data indicate that αSMACreERT2 labels a large proportion of osteoprogenitors in skeletal muscle, and therefore represents another marker of muscle-resident cells with osteogenic potential under HO-inducing stimulus. In contrast, muscle satellite cells make minimal contribution to bone formation in vivo.

Plasma myostatin is only a weak predictor for weight maintenance in obese adults

BACKGROUND

Predicting an individual's success in a non-surgical weight loss approach is a demanding need since obesity is becoming an epidemic burden. A possible predictive marker is myostatin, a member of the transforming growth factor b superfamily, which has been shown to be an important regulator of muscle homeostasis.

METHODS

In the present study, we analyzed myostatin as a marker to predict weight loss of patients that participated in a 2 phased weight reduction program, comprising a weight loss period of 12 weeks and a weight stabilization period of 40 weeks. Therefore, 62 obese individuals with a mean BMI of 40.6 kg/m(2) were included. Plasma myostatin was measured with ELISA at the beginning (T0), after weight loss (T1) and at the end of the program (T2).

RESULTS

Although significant weight loss of -23.9±14.9 kg was achieved, myostatin did not change significantly during the program (T0>T1: p=0.46; T1>T2: p=0.70; T0>T2: p=0.57). Myostatin at baseline did neither negatively correlate with the achieved weight loss in the weight reduction phase (T0>T1: r=0.27, p=0.16) nor with weight loss during the whole program (T0>T2: r=0.20, p=0.29). Only a minor correlation with myostatin levels after weight loss with weight regain during maintenance period was detected. (T1>T2: r=-0.37, p=0.05).

CONCLUSION

Plasma myostatin might be suitable in predicting weight regain after marked weight loss, but no association with weight loss was observed in patients undergoing a non-surgical weight loss program. Therefore, myostatin does not seem to be a predictor for success in non-surgical weight loss approaches.

Gene-expression analysis of cementoblasts and osteoblasts

BACKGROUND AND OBJECTIVE

Cementum and bone are similar mineralized tissues, but cementum accumulates much more slowly than bone, does not have vasculature or innervation and does not undergo remodeling. Despite these differences, there are no well-established markers to distinguish cementoblasts from other mature mineralizing cells such as osteoblasts and odontoblasts. The purpose of this study was to assess differences in gene expression between cementoblasts and osteoblasts using gene profiling of cell populations isolated directly from osteocalcin-green fluorescent protein (OC-GFP) transgenic mice.

MATERIAL AND METHODS

OC-GFP reporter mice were used as they show labeling of cementoblasts, osteoblasts and odontoblasts, but not of periodontal ligament fibroblasts, within the periodontium. We sorted cells digested from the molar root surface to isolate OC-GFP(+) cementoblasts. Osteoblasts were isolated from calvarial digests. Microarray analysis was performed, and selected results were confirmed by real-time PCR and immunostaining or in situ hybridization.

RESULTS

Microarray analysis identified 95 genes that were expressed at least two-fold higher in cementoblasts than in osteoblasts. Our analysis indicated that the Wnt signaling pathway was differentially regulated, as were genes related to skeletal development. Real-time PCR confirmed that expression of the Wnt inhibitors Wnt inhibitory factor 1 (Wif1) and secreted frizzled-related protein 1 (Sfrp1) was elevated in cementoblasts compared with osteoblasts, and Wif1 expression was localized to the apical root region. In addition, the transcription factor BARX homeobox 1 (Barx1) was expressed at higher levels in cementoblasts, and immunohistochemistry indicated that BARX1 was expressed in apical cementoblasts and cementocytes, but not in osteoblasts or odontoblasts.

CONCLUSION

The OC-GFP mouse provides a good model for selectively isolating cementoblasts, and allowed for identification of differentially expressed genes between cementoblasts and osteoblasts.

Pyrrolizidine alkaloids in medicinal plants from North America

Pyrrolizidine alkaloids (PAs) are mutagenic, carcinogenic, pneumotoxic, teratogenic and fetotoxic. Plants containing PAs commonly poison livestock in many countries, including the USA and Canada. In some regions of the world PA-producing plants sometimes grow in grain crops and items of food made with PA contaminated grain, such as bread baked using contaminated flour, have been, and continue to be, responsible for large incidents of acute, often fatal human poisoning. Herbal medicines and food supplements containing PAs are also recognized as a significant cause of human poisoning and it is desirable that such medications are identified and subjected to strict regulation. In this review we consider the PAs known to be, or likely to be, present in both the traditionally used medicinal plants of North America and also medicinal plants that have been introduced from other countries and are being recommended and used as phytopharmaceuticals in the USA and Canada.

Dose-response of superparamagnetic iron oxide labeling on mesenchymal stem cells chondrogenic differentiation: a multi-scale in vitro study

Aim

The aim of this work was the development of successful cell therapy techniques for cartilage engineering. This will depend on the ability to monitor non-invasively transplanted cells, especially mesenchymal stem cells (MSCs) that are promising candidates to regenerate damaged tissues.

Methods

MSCs were labeled with superparamagnetic iron oxide particles (SPIO). We examined the effects of long-term labeling, possible toxicological consequences and the possible influence of progressive concentrations of SPIO on chondrogenic differentiation capacity.

Results

No influence of various SPIO concentrations was noted on human bone marow MSC viability or proliferation. We demonstrated long-term (4 weeks) in vitro retention of SPIO by human bone marrow MSCs seeded in collagenic sponges under TGF-β1 chondrogenic conditions, detectable by Magnetic Resonance Imaging (MRI) and histology. Chondrogenic differentiation was demonstrated by molecular and histological analysis of labeled and unlabeled cells. Chondrogenic gene expression (COL2A2, ACAN, SOX9, COL10, COMP) was significantly altered in a dose-dependent manner in labeled cells, as were GAG and type II collagen staining. As expected, SPIO induced a dramatic decrease of MRI T2 values of sponges at 7T and 3T, even at low concentrations.

Conclusions

This study clearly demonstrates (1) long-term in vitro MSC traceability using SPIO and MRI and (2) a deleterious dose-dependence of SPIO on TGF-β1 driven chondrogenesis in collagen sponges. Low concentrations (12.5–25 µg Fe/mL) seem the best compromise to optimize both chondrogenesis and MRI labeling.

Respective interest of T2 mapping and diffusion tensor imaging in assessing porcine knee cartilage with MR at 3 Teslas

Non-invasive quantitative assessment of articular cartilage integrity is essential for early detection and evaluation of osteoarthritis (OA) and for the follow-up of stem-cell-driven cartilage engineering. In this study, we investigated the feasibility of exploiting diffusion tensor imaging (DTI) on porcine knee joints with a clinical magnetic resonance (MR) scanner to extract micro-structural information in order to complement biochemical information quantified by T2 maps. We propose an MR protocol for quantifying T2 and cartilage microstructure with diffusion MR on a clinical scanner. Preliminary results were obtained on four pig knee joints using a 3 T GE clinical MRI scanner and an 8-channel knee coil array. The measured cartilage volume, T2 values, apparent diffusion coefficient and fractional anisotropy (FA) of femoral and tibial cartilage were respectively 9.8/2.3 mm2, 67.0/56.1 ms, 1.3/1.3×10-3 mm2/s and 0.4/0.3. This new protocol has the potential to be combined in vivo with quantitative assessment of both cartilage degradation and restoration in osteoarthritis.

Toxic pyrrolizidinalkaloids as undesired contaminants in food and feed: degradation of the PAs from Senecio jacobaea in silage

Pyrrolizidine alkaloids (PAs) can show a hazardous potential for men and animals. They can act as cancerogenic, mutagenic, teratogenic and fetotoxic agents. One pathway of a human intoxication is its occurence as contaminants in food and feed. Here, the contamination of cereals already led to severe and fatal intoxication episodes. Besides this, milk is of special concern as it is the main food for children which show a very high susceptibility for a PA intoxication. Milk can contain PAs in case the milk producing animals have access to contaminated feed. In this context it is of special interest whether the PA content of contaminated silage remains stable during the ensiling procedure or show a more or less high level of decomposition. We could show that ensiling will not lead to PA-free silage.

Plants containing pyrrolizidine alkaloids used in the traditional Indian medicine--including ayurveda

Pyrrolizidine alkaloids (PAs) show a hazardous potential for humans and animals. They can possess mutagenic, teratogenic, cancerogenic and fetotoxic properties. One pathway of a human intoxication can be the use of medicinal plants which contain toxic PAs. The Traditional Indian medicine--in particular Ayurveda--is a popular and well-known healing system. Within this system several PA-containing plants are used which, on account of their PA level, represent a severe health risk. In general, it is not recommended to use plants containing those toxic compounds.

Effect of dynamic loading on MSCs chondrogenic differentiation in 3-D alginate culture

Mesenchymal stem cells (MSCs) are regarded as a potential autologous source for cartilage repair, because they can differentiate into chondrocytes by transforming growth factor-beta (TGF-β) treatment under the 3-dimensional (3-D) culture condition. In addition to these molecular and biochemical methods, the mechanical regulation of differentiation and matrix formation by MSCs is only starting to be considered. Recently, mechanical loading has been shown to induce chondrogenesis of MSCs in vitro. In this study, we investigated the effects of a calibrated agitation on the chondrogenesis of human bone MSCs (MSCs) in a 3-D alginate culture (day 28) and on the maintenance of chondrogenic phenotypes. Biomechanical stimulation of MSCs increased: (i) types 1 and 2 collagen formation; (ii) the expression of chondrogenic markers such as COMP and SOX9; and (iii) the capacity to maintain the chondrogenic phenotypes. Notably, these effects were shown without TGF-β treatment. These results suggest that a mechanical stimulation could be an efficient method to induce chondrogenic differentiation of MSCs in vitro for cartilage tissue engineering in a 3-D environment. Additionally, it appears that MSCs and chondrocyte responses to mechanical stimulation are not identical.

Pyrrolizidine alkaloids in plants used in the traditional medicine of Madagascar and the Mascarene islands

Pyrrolizidine alkaloids (PAs) can be hazardous to the health of humans and animals. Although their toxicity has been known for a long time, PA containing plants are still in use in many traditional medicines. Traditional healing systems have become of increasing interest as many people believe that they can be used without any risk and side effects. This also applies to the traditional medicine of Madagascar and the Mascarene island (Mauritius, Reunion, Rodriguez). Recent literature reports have recommended this traditional medicine because of its good efficacy and pharmacological properties. However, several plants are listed there which have already been described to contain toxic PAs or are suspected of containing them.

Weight loss improves endothelial function independently of ADMA reduction in severe obesity

This prospective study was performed in order to establish whether improvement of endothelial function after weight reduction can be explained by a decrease of elevated asymmetric dimethyl arginine (ADMA), an inhibitor of endogenous NO-synthase (eNOS). Therefore, 21 obese subjects (BMI: 41.1±6.4 kg/m(2)) were studied at baseline and after 12 weeks of weight reduction with a very low calorie diet. Biochemical and clinical parameters of endothelial function were assessed before and after weight loss. Biochemical parameters were determined by measurement of ADMA and soluble intercellular adhesion molecule (sICAM). Clinical parameters were assessed by pulse wave analysis (PWA). Weight intervention resulted in a 21.4±6.8 kg reduction of body weight from 119.7±12.8 kg at study start to 98.3±11.6 kg at study end (p<0.001). Accordingly, biochemical markers improved under weight reduction (ADMA from 0.47±0.07 mmol/l to 0.42±0.08 mmol/l; p=0.002; ICAM from 276±42 ng/ml to 236±29 ng/ml; p<0.001). Further, clinical parameters of functional endothelial function improved with an increase of deltaRI after salbutamol inhalation from -1% before to -9% after weight reduction (p=0.02). Interestingly, improvement of endothelial function correlated with improved HOMA index only (r=-0.60, p=0.04) but not with reduced ADMA levels, improved hypertension or reduced body weight. In conclusion, weight reduction with a very low calorie diet improves endothelial function measured by pulse wave velocity. The missing correlation with ADMA suggests possible further mechanisms underlying this observed effect, for example, improvement of insulin resistance.

Expression of chondrogenic genes by undifferentiated vs. differentiated human mesenchymal stem cells using array technology

This study investigated the gene expression profile of human mesenchymal stem cells seeded in collagen sponge for 28 days in three different mediums: (1) basal medium as control containing ITS alone, (2) ITS+TGF-β1 alone or (3) ITS 1% supplemented sequentially by TGF-β1 (D3-D14) followed by BMP-2 (D15-D28). Differential expression of 84 genes implicated in chondrogenic and osteogenic differentiation of MSCs was analyzed at D28 by real-time RT-PCR array technology. TGF-β1 alone down-regulated two genes, CD36 and cathepsin K. Sixteen genes were significantly up-regulated, notably type 2 and type 10 collagens, COMP and Sox9. The sequential combination of TGF-β1 and BMP-2 produced a similar profile with prominent expression of type 2 collagen and the alkaline phosphatase gene. Interestingly, in this in vitro condition, RUNX2 was not up-regulated, suggesting that the sequential combination of TGF-β1/BMP2 enhances the hypertrophic chondrogenic profile without turning towards the osteoblastic pathway.

Pyrrolizidine alkaloids in medicinal plants of Mongolia, Nepal and Tibet

Pyrrolizidine alkaloids (PAs) are widely distributed in many plant families. Most of them are hazardous for humans and domestic animals. PA also occur in many medicinal plants. This is of importance because in Western countries the use of plants or preparations of them is more and more increasing. Especially plants of the Traditional Chinese Medicine (TCM) have increased in popularity. Similarly, people are also focused on medicinal plants from other traditional medicines. Nowadays the Traditional Mongolian Medicine (TMM), the Traditional Nepalese Medicine (TNM), and the Tibetan System of Medicine (TSM) are becoming more and more of interest. In those countries application of those phytopharmaceutics is based on its traditional use but a scientific investigation--especially for possible toxic side-effects--is often missing. This paper gives an overview on traditionally used plants from Nepal, Mongolia and Tibet with respect to its content or its possible content of pyrrolizidine alkaloids.

Lycopsamine and cumambrin B from Eupatorium maculatum

The pyrrolizidine alkaloid (PA) lycopsamine and the guaianolide cumambrin B were isolated from Eupatorium maculatum L. Their structures were elucidated by spectroscopical methods.

Identification of proximal 1p36 deletions using array-CGH: a possible new syndrome

Monosomy 1p36 is the most common terminal deletion syndrome with an estimated occurrence of 1:5000 live births. Typically, the deletions span <10 Mb of 1pter-1p36.23 and result in mental retardation, developmental delay, sensorineural hearing loss, seizures, cardiomyopathy and cardiovascular malformations, and distinct facies including large anterior fontanel, deep-set eyes, straight eyebrows, flat nasal bridge, asymmetric ears, and pointed chin. We report five patients with 'atypical' proximal interstitial deletions from 1p36.23-1p36.11 using array-comparative genomic hybridization. Four patients carry large overlapping deletions of approximately 9.38-14.69 Mb in size, and one patient carries a small 2.97 Mb deletion. Interestingly, these patients manifest many clinical characteristics that are different from those seen in 'classical' monosomy 1p36 syndrome. The clinical presentation in our patients included: pre- and post-natal growth deficiency (mostly post-natal), feeding difficulties, seizures, developmental delay, cardiovascular malformations, microcephaly, limb anomalies, and dysmorphic features including frontal and parietal bossing, abnormally shaped and posteriorly rotated ears, hypertelorism, arched eyebrows, and prominent and broad nose. Most children also displayed hirsutism. Based on the analysis of the clinical and molecular data from our patients and those reported in the literature, we suggest that this chromosomal abnormality may constitute yet another deletion syndrome distinct from the classical distal 1p36 deletion syndrome.

Neuroprotective effects of hydroxysafflor yellow A: in vivo and in vitro studies

Previous work has shown that hydroxysafflor yellow A (HSYA), extracted from Carthamus tinctorius L. markedly extended the coagulation time in mice and exhibited a significant antithrombotic effect in rats. The present study was conducted to demonstrate further its neuroprotective effects on cerebral ischemic injury in both in vivo and in vitro studies. In vivo, male Wistar-Kyoto (WKY) rats with middle cerebral artery occlusion (MCAO) were evaluated for neurological deficit scores followed by the treatment with a single dose of HSYA. Furthermore, the infarction area of the brain was assessed in the brain slices. In vitro, the effect of HSYA was tested in cultured fetal cortical cells exposed to glutamate and sodium cyanide (NaCN) to identify its neuroprotection against neurons damage. The results in vivo showed that sublingular vein injection of HSYA at doses of 3.0 mg/kg and 6.0 mg/kg exerted significant neuroprotective effects on rats with focal cerebral ischemic injury by significantly decreasing neurological deficit scores and reducing the infarct area compared with the saline group, HSYA at a dose of 6.0 mg/kg showed a similar potency as nimodipine at a dose of 0.2 mg/kg. Sublingular vein injection of HSYA at the dose of 1.5 mg/kg showed a neuroprotective effect, however, with no significant difference when compared with the saline group. Results in vitro showed that HSYA significantly inhibited neuron damage induced by exposure to glutamate and sodium cyanide (NaCN) in cultured fetal cortical cells. Noticeably, the neuroprotective action of HSYA on glutamate-mediated neuron injury was much better than that of HSYA on NaCN-induced neuron damage. All these findings suggest that HSYA might act as a potential neuroprotective agent useful in the treatment in focal cerebral ischemia. Abbreviations. HSYA:hydroxysafflor yellow A TTC:2,3,5-triphenyltetrazolium chloride MTT:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide DMEM:Dulbecco's modified Eagle medium FCS:Fetal calf serum MCAO:middle cerebral artery occlusion ECA:external carotid artery ICA:internal carotid artery LDH:lactate dehydrogenase NMDA: N-methyl- D-aspartate

Trisomy 12 mosaicism confirmed in multiple organs from a liveborn child

This patient, in whom trisomy 12 mosaicism was confirmed in multiple organs, is the fifth case diagnosed postnatally and the first reported for whom a meiotic origin of the trisomy, maternal meiosis I, was determined. Mosaic aneuploidy was suspected because of pigmentary dysplasia, a frequent but non-specific finding in chromosomal mosaicism. The severe phenotype of this child, who died in infancy with a complex heart malformation, was probably a result of the high percentage of trisomic cells. Cytogenetic and interphase fluorescent in situ hybridization analyses showed a highly variable distribution of aneuploid cells in the nine tissues studied, from none in blood and ovary to 100% in spleen and liver. The trisomy arose meiotically with apparent post-zygotic loss of one of the chromosomes 12; uniparental disomy for this chromosome in the diploid cell line was excluded. The phenotype of the cases reported in living or liveborn individuals has been extremely variable, ranging from the present case, in which the child died in infancy with multiple malformations and pigmentary dysplasia, to a fortuitous finding in an adult studied for infertility. The variation in severity is probably determined by the proportion and distribution of the trisomic cells, which is linked to the timing of the non-disjunctional error.

Medicinal plants in China containing pyrrolizidine alkaloids

Medicinal plants and remedies are widely used for various ailments throughout the world. Many of these plants contain pyrrolizidine alkaloids (PAs) which are hepatotoxic, pneumotoxic, genotoxic, neurotoxic, and cytotoxic. As a result of their use in Traditional Chinese Medicine (TCM), medicinal plants are becoming increasingly important not only in China but also in many other countries. This paper will therefore give, a critical overview of PA-containing plants belonging mainly to the families Boraginaceae, Leguminosae (Tribus Crotalarieae), and Asteraceae (Tribus Senecioneae and Eupatorieae). The PAs contained in the 38 plants described here differ widely in their structure and toxicity. Their metabolism and the resulting toxicity will be discussed, the dehydroalkaloids (DHAlk) produced in the liver playing a key role in cases of intoxications.

Fronto-otopalatodigital osteodysplasia: clinical evidence for a single entity encompassing Melnick-Needles syndrome, otopalatodigital syndrome types 1 and 2, and frontometaphyseal dysplasia

Otopalatodigital syndrome type 2 is an X-linked disorder with minimal expression in carrier females and comprises typical facial anomalies and a generalized bone dysplasia with osteodysplastic changes, brachydactyly, and impaired survival. Recently several other severe malformations were reported in the condition. Melnick-Needles syndrome is an X-linked dominant disorder. Affected males are usually sporadic cases. The exceptional males born to symptomatic women present with a lethal disorder comprising generalized osteodysplasia, deficiency of the first ray, and facial anomalies strikingly similar to those of otopalatodigital syndrome type 2. We report here on three boys with classical, severe, and lethal otopalatodigital type 2 syndrome, and three boys with severe (lethal) Melnick-Needles syndrome, born to affected mothers. We suggest that otopalatodigital type 1 and 2, Melnick-Needles syndrome and frontometaphyseal dysplasia, sharing many clinical manifestations and a similar mode of inheritance, are variants of the same condition: fronto-otopalatodigital osteodysplasia. The relationships to similar syndromes (i.e., Saint-Martin-Gardner-Morrisson syndrome, serpentine fibula syndrome, atelosteogenesis type 3, boomerang dysplasia, and Yunis-Varon syndrome) are discussed.

Apparent cyclophosphamide (cytoxan) embryopathy: a distinct phenotype?

Cyclophosphamide (CP) is an alkylating agent widely used in treating cancer and autoimmune disease. CP is classified as a pregnancy risk factor D drug and is teratogenic in animals, but population studies have not conclusively demonstrated teratogenicity in humans. Six isolated reports of prenatally exposed infants with various congenital anomalies exist, but to date no specific phenotype has been delineated. The purpose of this report is to document a new case of in utero CP exposure with multiple congenital anomalies and to establish an apparent CP embryopathy phenotype. The mother had systemic lupus erythematosus and cyclophosphamide exposure in the first trimester. She also took nifedipine, atenolol, clonidine, prednisone, aspirin, and potassium chloride throughout pregnancy. The infant had growth retardation and multiple anomalies including microbrachycephaly, coronal craniosynostosis, hypotelorism, shallow orbits, proptosis, blepharophimosis, small, abnormal ears, unilateral preauricular pit, broad, flat nasal bridge, microstomia, high-arched palate, micrognathia, preaxial upper limb and postaxial lower limb defects consisting of hypoplastic thumbs, and bilateral absence of the 4th and 5th toes. Chromosomes were apparently normal. The reported cases of in utero exposure to cyclosposphamide shared the following manifestations with our patient: growth deficiency, developmental delay, craniosynostosis, blepharophimosis, flat nasal bridge, abnormal ears, and distal limb defects including hypoplastic thumbs and oligodactyly. We conclude that (a) cyclophosphamide is a human teratogen, (b) a distinct phenotype exists, and (c) the safety of CP in pregnancy is in serious question.

Familial paragangliomas: the emerging impact of molecular genetics on evaluation and management

HYPOTHESIS

Advancements in molecular genetics has direct impact on the evaluation and management of patients and family members with familial paragangliomas (FP).

BACKGROUND

Familial paragangliomas. in contrast to sporadic cases, are commonly multiple, bilateral, and present at an earlier age. Familial tumors are inherited in an autosomal dominant pattern with genomic imprinting of the paternal allele. Mapping studies have identified regions on chromosome 11q as harboring the genetic defect responsible for paraganglioma formation.

METHODS

A multigenerational family with five affected females with head and neck paragangliomas underwent clinical and genetic evaluation. Genetic mapping was performed with microsatellite markers froin chromosome 11q13 and q23. Nonaffected individuals were screened for carrying the affected haplotype. In addition, by using DNA obtained from an amniotic fluid sample. in utero screening of a fetus was performed.

RESULTS

The most common complaints were hearing loss and neck masses that usually manifested by age 25. Genetic mapping identified loci 11q13 and q23 as sites likely responsible for tumorogenesis. Three unaffected family members, including a fetus, were identified as carriers of the affected haplotype. The genetic findings were used to design a screening protocol for family members at risk for developing glomus tumors.

CONCLUSIONS

Genetic screening of unaffected family members can identify individuals harboring the mutated allele. Identification of family members at risk for developing FP by molecular genetic techniques may lead to early detection of head and neck paragangliomas and may directly impact morbidity from glomus tumors and their treatment.

Pyrrolizidine alkaloids from Senecio nevadensis

Two toxic pyrrolizidine alkaloids were isolated from Senecio nevadensis and their structures determined by spectroscopic methods. For the first time, a very complete structural assignment of all spectral data of alkaloid usaramine is given.

Ritscher-Schinzel (3C) syndrome: documentation of the phenotype

Ritscher-Schinzel syndrome or 3C (craniocerebello-cardiac) syndrome is characterized by cardiac defects, cerebellar vermis hypoplasia, and cranial defects. Nineteen cases were reported previously; however, the full spectrum of this disorder has not been determined. We have evaluated two unrelated males with this condition. Both had defects of the endocardial cushion and vermis hypoplasia with hypotonia. In addition, both had hypospadias, a previously undescribed finding of this disorders. Review of the previously reported cases and those described herein demonstrate: 1) Although varying degrees of vermis hypoplasia are accompanied by hypotonia, delayed gross motor function improves with advancing age leaving speech delay as the major neurodevelopmental handicap. 2) Two different types of cardiac anomalies occur: defects of the endocardial cushion ranging from anomalies of the mitral or tricuspid valves to complete AV canal, and/or conotruncal defects. 3) Postnatal growth deficiency was seen in most patients in whom longitudinal information was available. In our review of patients with vermis hypoplasia we ascertained a patient diagnosed as having "Joubert syndrome" who had most findings of the Ritscher-Schinzel syndrome and several other patients with "Dandy-Walker syndrome" who likely have had Ritscher-Schinzel syndrome, suggesting that Ritscher-Schinzel syndrome is more common than has been appreciated. Careful search for the subtle facial changes characteristic of this disorder as well as coloboma, cleft palate/bifid uvula, short neck, syndactyly, and hypoplasia of the nails is warranted when evaluating children with Dandy-Walker malformation with or without clinical signs of Joubert syndrome.

Pentapeptides from the roots of Aster tataricus

Asterinin D and E, pentapeptides, have been isolated from the roots of Aster tataricus L.f. (Compositae, syn. Asteraceae, subtribe Asteroideae) and their structures have been elucidated on the basis of spectroscopic analysis, as well as chemical and enzymatic methods.

New pentapeptides from Aster tataricus

Three pentapeptides have been isolated from the roots of Aster tataricus and their structures elucidated on the basis of spectroscopic analysis as well as chemical and enzymatic methods.

Pyrrolizidine alkaloids from Eupatorium portoricense

Three pyrrolizidine alkaloids were isolated from Eupatorium portoricense and their structures elucidated by spectroscopic methods as (-)-viridifloryl-supinidine (amabiline), (-)-viridifloryl-heliotridine (echinatine), and C12- O-acetyl-(-)-viridifloryl-heliotridine (O(12)-acetylechinatine).

Effect of myotonic dystrophy trinucleotide repeat expansion on DMPK transcription and processing

The myotonic dystrophy (DM) mutation has been identified as an unstable, expanded (CTG)n repeat in the 3' untranslated region of a gene designated DM protein kinase (DMPK). Both decreased and increased levels of mutant DMPK mRNA as well as decreased levels of protein have been variously reported and invoked to explain disparate molecular bases of this dominantly inherited disease. Most recently, increased nucleosome binding to such expanded repeats has been interpreted as support for transcriptional repression. A quantitative allele-specific RT-PCR procedure was developed and applied to a spectrum of patient tissue samples and cell lines. Equal levels of unprocessed pre-mRNA were produced by the wildtype (+) and disease (DM) alleles in skeletal muscle and cell lines of heterozygous DM patients. Thus, any increased nucleosome binding had no effect at the level of transcriptional initiation and transcription of the mutant DMPK locus. In contrast, processed mRNA levels from the DM allele were reduced relative to the+allele as the size of the expansion increased. The unstable repeat, therefore, impairs post-transcriptional processing of DM allele transcripts. This phenomenon has profound effects on overall DMPK locus steady-state transcript levels in cells missing a wildtype allele and does not appear to be mediated by imprinting, decreased mRNA stability, generation of aberrant splice forms, or absence of polyadenylation of the mutant allele.

Analysis of pyrrolizidine alkaloids: a competitive enzyme-linked immunoassay (ELISA) for the quantitative determination of some toxic pyrrolizidine alkaloids

A highly sensitive and specific competitive enzyme-linked immunoassay (ELISA) for the determination of retrorsine, senecionine, and integerrimine in the nanogram range has been developed. Pyrrolizidine alkaloids were detected in Senecio rupestris. No cross-reactivity was seen with either retrosine N-oxide, otonecine alkaloids, or other macrocyclic pyrrolizidine alkaloids.