Bone morphogenetic protein 2/SMAD signalling in human ligamentocytes of degenerated and aged anterior cruciate ligaments.

OBJECTIVE: Anterior cruciate ligament (ACL) degeneration leads to knee instability and favors osteoarthritis (OA) progression. During ageing the growth factor sensitivity of ligaments changes but nothing is known about BMP2-signalling and -sensitivity in degenerated ACLs. This study addressed the question whether a dysregulated BMP2 signalling might contribute to age- and OA-dependent ACL degeneration. METHOD: ACL samples from patients with/without OA of different ages (<60 and ≥60 years, males, females) were graded histopathologically (n = 45). After stimulation of cultured ACL fibroblasts with 5 nM BMP2 for different time points, phosphorylation of SMAD1/5/8 and gene expression of crucial BMP2 signalling proteins, ligamentogenic and chondrogenic transcription factors, scleraxis (SCX) and SOX9, were analyzed. RESULTS: ACL samples displayed different grades of degeneration, often associated with synovitis and calcium deposits. Degeneration correlated significantly with synovitis. ACL fibroblasts expressed BMP type I receptors ALK3 and ALK6 and the BMP type II receptor BMPRII. Donors could be divided into "responders" and "non responders" since their BMP2 mediated SMAD1/5/8 phosphorylation level differed. Basal ID1 expression was lower in cells derived from OA compared with non-OA patients and BMP2 led to an ID1 induction in both. Irrespective of BMP2 stimulation, the donor age significantly influenced the expression profile of BMP6 and SCX but not BMP signalling. The BMP2-mediated SMAD6 expression differed between OA and healthy ACL fibroblasts. CONCLUSION: Our data indicate that the expression level of BMP2/SMAD target genes such as ID1 and SMAD6 was reduced in ACL fibroblasts derived from OA compared with non OA patients.

Regulation of osteoarthritis-associated key mediators by TNFα and IL-10: effects of IL-10 overexpression in human synovial fibroblasts and a synovial cell line.

Synovial fibroblasts (SF) contribute to the pathogenesis of osteoarthritis (OA), but the effects of intra-articular cytokines on SF are not completely understood. The aim of this study was to characterize the interplay between tumor necrosis factor (TNF)α and the anti-inflammatory interleukin (IL)-10. Non-immortalized human SF and SF of the human cell line K4IM were stimulated with recombinant TNFα, IL-10, or TNFα + IL-10 (10 ng/ml each) for 24 h or transduced with an adenoviral vector overexpressing human IL-10 (hIL-10) and subsequently treated with 10 ng/ml TNFα for 24 h. Effects on the gene expression and protein synthesis of IL-6, IL-10, matrix metalloproteinases (MMP)-1, -3, type I collagen, ß1-integrin, and CD44 were investigated via real-time detection polymerase chain reaction, immunofluorescence labeling, flow cytometry, and Western blotting. IL-10 release by transduced SF was confirmed with enzyme-linked immunosorbent assay. Both cell populations were activated by TNFα and by TNFα + IL-10, increasing their gene expression and protein synthesis of IL-6, IL-10, MMP-1, and MMP-3 and altering the synthesis of type I collagen, ß1-integrin, and CD44. hIL-10 overexpression greatly elevated the gene expression and protein synthesis of IL-10. However, transduction did not significantly affect the gene expression of IL-6, MMP-1, and MMP-3 in SF. The increased expression of pro-inflammatory and catabolic mediators in TNFα-activated SF indicates their role in OA pathogenesis, suggesting they are a potential therapeutic target. Although the vigorousness of the responses of non-immortalized SF and K4IM clearly differ, the K4IM cell line seems to be a suitable model for non-immortalized human SF.

PGA-associated heterotopic chondrocyte cocultures: implications of nasoseptal and auricular chondrocytes in articular cartilage repair.

The availability of autologous articular chondrocytes remains a limiting issue in matrix assisted autologous chondrocyte transplantation. Non-articular heterotopic chondrocytes could be an alternative autologous cell source. The aims of this study were to establish heterotopic chondrocyte cocultures to analyze cell-cell compatibilities and to characterize the chondrogenic potential of nasoseptal chondrocytes compared to articular chondrocytes. Primary porcine and human nasoseptal and articular chondrocytes were investigated for extracellular cartilage matrix (ECM) expression in a monolayer culture. 3D polyglycolic acid- (PGA) associated porcine heterotopic mono- and cocultures were assessed for cell vitality, types II, I, and total collagen-, and proteoglycan content. The type II collagen, lubricin, and Sox9 gene expressions were significantly higher in articular compared with nasoseptal monolayer chondrocytes, while type IX collagen expression was lower in articular chondrocytes. Only ß1-integrin gene expression was significantly inferior in humans but not in porcine nasoseptal compared with articular chondrocytes, indicating species-dependent differences. Heterotopic chondrocytes in PGA cultures revealed high vitality with proteoglycan-rich hyaline-like ECM production. Similar amounts of type II collagen deposition and type II/I collagen ratios were found in heterotopic chondrocytes cultured on PGA compared to articular chondrocytes. Quantitative analyses revealed a time-dependent increase in total collagen and proteoglycan content, whereby the differences between heterotopic and articular chondrocyte cultures were not significant. Nasoseptal and auricular chondrocytes monocultured in PGA or cocultured with articular chondrocytes revealed a comparable high chondrogenic potential in a tissue engineering setting, which created the opportunity to test them in vivo for articular cartilage repair.

Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients

Objective: To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point. Methods: Where available, the literature was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear. Recommendations: The article is focused on a suggested glycemic control end point such that a blood glucose ≥150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ≤70 mg/dL) and to minimize glycemic variability. Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients. Conclusions: While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.

Elevated plasma long pentraxin-3 levels and primary graft dysfunction after lung transplantation for idiopathic pulmonary fibrosis.

Primary graft dysfunction (PGD) after lung transplantation may result from ischemia reperfusion injury (IRI). The innate immune response to IRI may be mediated by Toll-like receptor and IL-1-induced long pentraxin-3 (PTX3) release. We hypothesized that elevated PTX3 levels were associated with PGD. We performed a nested case control study of lung transplant recipients with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) from the Lung Transplant Outcomes Group cohort. PTX3 levels were measured pretransplant, and 6 and 24 h postreperfusion. Cases were subjects with grade 3 PGD within 72 h of transplantation and controls were those without grade 3 PGD. Generalized estimating equations and multivariable logistic regression were used for analysis. We selected 40 PGD cases and 79 non-PGD controls. Plasma PTX3 level was associated with PGD in IPF but not COPD recipients (p for interaction < 0.03). Among patients with IPF, PTX3 levels at 6 and 24 h were associated with PGD (OR = 1.6, p = 0.02 at 6 h; OR = 1.4, p = 0.008 at 24 h). Elevated PTX3 levels were associated with the development of PGD after lung transplantation in IPF patients. Future studies evaluating the role of innate immune activation in IPF and PGD are warranted.

In vitro and in vivo neo-cartilage formation by heterotopic chondrocytes seeded on PGA scaffolds.

Implantation of tissue-engineered heterotopic cartilage into joint cartilage defects might be an alternative approach to improve articular cartilage repair. Hence, the aim of this study was to characterize and compare the quality of tissue-engineered cartilage produced with heterotopic (auricular, nasoseptal and articular) chondrocytes seeded on polyglycolic acid (PGA) scaffolds in vitro and in vivo using the nude mice xenograft model. PGA scaffolds were seeded with porcine articular, auricular and nasoseptal chondrocytes using a dynamic culturing procedure. Constructs were pre-cultured 3 weeks in vitro before being implanted subcutaneously in nude mice for 1, 6 or 12 weeks, non-seeded scaffolds were implanted as controls. Heterotopic neo-cartilage quality was assessed using vitality assays, macroscopical and histological scoring systems. Neo-cartilage formation could be observed in vitro in all PGA associated heterotopic chondrocytes cultures and extracellular cartilage matrix (ECM) deposition increased in vivo. The 6 weeks in vivo incubation time point leads to more consistent results for all cartilage species, since at 12 weeks in vivo construct size reductions were higher compared with 6 weeks except for auricular chondrocytes PGA cultures. Some regressive histological changes could be observed in all constructs seeded with all chondrocytes subspecies such as cell-free ECM areas. Particularly, but not exclusively in nasoseptal chondrocytes PGA cultures, ossificated ECM areas appeared. Elastic fibers could not be detected within any neo-cartilage. The neo-cartilage quality did not significantly differ between articular and non-articular chondrocytes constructs. Whether tissue-engineered heterotopic neo-cartilage undergoes sufficient transformation, when implanted into joint cartilage defects requires further investigation.

Elevated plasma clara cell secretory protein concentration is associated with high-grade primary graft dysfunction.

Primary graft dysfunction (PGD) is the leading cause of early posttransplant morbidity and mortality after lung transplantation. Clara cell secretory protein (CC16) is produced by the nonciliated lung epithelium and may serve as a plasma marker of epithelial cell injury. We hypothesized that elevated levels of CC16 would be associated with increased odds of PGD. We performed a prospective cohort study of 104 lung transplant recipients. Median plasma CC16 levels were determined at three time points: pretransplant and 6 and 24 h posttransplant. The primary outcome was the development of grade 3 PGD within the first 72 h after transplantation. Multivariable logistic regression was performed to evaluate for confounding by donor and recipient demographics and surgical characteristics. Twenty-nine patients (28%) developed grade 3 PGD within the first 72 h. The median CC16 level 6 h after transplant was significantly higher in patients with PGD [13.8 ng/mL (IQR 7.9, 30.4 ng/mL)] than in patients without PGD [8.2 ng/mL (IQR 4.5, 19.1 ng/mL)], p = 0.02. Elevated CC16 levels were associated with increased odds of PGD after lung transplantation. Damage to airway epithelium or altered alveolar permeability as a result of lung ischemia and reperfusion may explain this association.

The role of pro-inflammatory and immunoregulatory cytokines in tendon healing and rupture: new insights.

Owing to limited self-healing capacity, tendon ruptures and healing remain major orthopedic challenges. Increasing evidence suggests that post-traumatic inflammatory responses, and hence, cytokines are involved in both cases, and also in tendon exercise and homeostasis. This review summarizes interrelations known between the cytokines interleukin (IL)-1ß, tumor necrosis factor (TNF)α, IL-6 and vascular endothelial growth factor (VEGF) in tendon to assess their role in tendon damage and healing. Exogenic cytokine sources are blood-derived leukocytes that immigrate in damaged tendon. Endogenous expression of IL-1ß, TNFα, IL-6, IL-10 and VEGF was demonstrated in tendon-derived cells. As tendon is a highly mechanosensitive tissue, cytokine homeostasis and cell survival underlie an intimate balance between adequate biomechanical stimuli and disturbance through load deprivation and overload. Multiple interrelations between cytokines and tendon extracellular matrix (ECM) synthesis, catabolic mediators e.g. matrix-degrading enzymes, inflammatory and angiogenic factors (COX-2, PGE2, VEGF, NO) and cytoskeleton assembly are evident. Pro-inflammatory cytokines affect ECM homeostasis, accelerate remodeling, amplify biomechanical adaptiveness and promote tenocyte apoptosis. This multifaceted interplay might both contribute to and interfere with healing. Much work must be undertaken to understand the particular interrelation of these inflammatory and regulatory mediators in ruptured tendon and healing, which has relevance for the development of novel immunoregulatory therapeutic strategies.

FLIP&FLAP-a training programme for children and adolescents with epilepsy, and their parents.

OBJECTIVE: The objective of this article is to present the development, contents and efficacy of the FLIP&FLAP programme for children and adolescents with epilepsy, and their parents. INTERVENTION: The programme is mainly directed at age-appropriately developed children and adolescents between 6 and 16 who take antiepileptic drugs. It is conducted as a 2.5-day group training programme; children and parents are grouped separately. The main focuses are: EVALUATION STUDY: We performed a multi-centre non-randomised two-group pre-/post-trial using a waiting-list control group design. 10 German epilepsy centres participated. The intervention group, IG (21 children 8-11 years, 44 adolescents 12-16 years, 72 parents) completed standardised questionnaires immediately before the FLIP&FLAP course and 6 months later; the waiting control group, WCG (31 children, 39 adolescents, 72 parents) 6 months before and immediately before the course. Compared to the WCG, the children and parents of the IG showed significantly improved knowledge of epilepsy, with medium to large effect sizes (univariate analysis of variance with repeated measurements, d=0.6-1.4). Parents of the IG reported improved self-management skills (d=0.7) and communication skills (d=0.8) of their child and fewer epilepsy-related worries (d=0.5). Children and adolescents of the IG reported improved HRQOL in the Social Exclusion dimension (d=0.3). CONCLUSION: FLIP&FLAP is an effective child- and family-centred programme. It is currently being established in Northern Germany to test its usefulness in routine care.

Differing in vitro biology of equine, ovine, porcine and human articular chondrocytes derived from the knee joint: an immunomorphological study.

For lack of sufficient human cartilage donors, chondrocytes isolated from various animal species are used for cartilage tissue engineering. The present study was undertaken to compare key features of cultured large animal and human articular chondrocytes of the knee joint. Primary chondrocytes were isolated from human, porcine, ovine and equine full thickness knee joint cartilage and investigated flow cytometrically for their proliferation rate. Synthesis of extracellular matrix proteins collagen type II, cartilage proteoglycans, collagen type I, fibronectin and cytoskeletal organization were studied in freshly isolated or passaged chondrocytes using immunohistochemistry and western blotting. Chondrocytes morphology, proliferation, extracellular matrix synthesis and cytoskeleton assembly differed substantially between these species. Proliferation was higher in animal derived compared with human chondrocytes. All chondrocytes expressed a cartilage-specific extracellular matrix. However, after monolayer expansion, cartilage proteoglycan expression was barely detectable in equine chondrocytes whereby fibronectin and collagen type I deposition increased compared with porcine and human chondrocytes. Animal-derived chondrocytes developed more F-actin fibers during culturing than human chondrocytes. With respect to proliferation and extracellular matrix synthesis, human chondrocytes shared more similarity with porcine than with ovine or equine chondrocytes. These interspecies differences in chondrocytes in vitro biology should be considered when using animal models.

IL-10 overexpression differentially affects cartilage matrix gene expression in response to TNF-alpha in human articular chondrocytes in vitro.

Cartilage-specific extracellular matrix synthesis is the prerequisite for chondrocyte survival and cartilage function, but is affected by the pro-inflammatory cytokine TNF-alpha in arthritis. The aim of the present study was to characterize whether the immunoregulatory cytokine IL-10 might modulate cartilage matrix and cytokine expression in response to TNF-alpha. Primary human articular chondrocytes were treated with either recombinant IL-10, TNF-alpha or a combination of both (at 10ng/mL each) or transduced with an adenoviral vector overexpressing human IL-10 and subsequently stimulated with 10ng/ml TNF-alpha for 6 or 24h. The effects of IL-10 on the cartilage-specific matrix proteins collagen type II, aggrecan, matrix-metalloproteinases (MMP)-3, -13 and pro-inflammatory cytokines were evaluated by real-time RT-PCR and immunohistochemistry. Transduced chondrocytes overexpressed high levels of IL-10 which significantly up-regulated collagen type II expression. TNF-alpha suppressed collagen type II and aggrecan, but increased MMP and cytokine expression in chondrocytes compared to the non-stimulated controls. The TNF-alpha mediated down-regulation of aggrecan expression was significantly antagonized by IL-10 overexpression, whereas the suppression of collagen type II was barely affected. The MMP-13 and IL-1beta expression by TNF-alpha was slightly reduced by IL-10. These results suggest that IL-10 overexpression modulates some catabolic features of TNF-alpha in chondrocytes.

Interleukin-10 modulates pro-apoptotic effects of TNF-alpha in human articular chondrocytes in vitro.

The aim of this study is to determine if there is an antagonistic effect between tumour necrosis factor (TNF)-alpha and the immunoregulatory interleukin (IL)-10 on chondrocytes survival. Serum-starved primary human articular chondrocytes were stimulated with either 10 ng/ml recombinant TNF-alpha, IL-10 or a combination of both (at 10 ng/ml each). Chondrocyte apoptosis was determined by measuring caspase-3/7, -8 and -9 activities using caspase assays. Mitochondrial apoptotic inducer bax, and the suppressor bcl-2 were evaluated using western blotting at 48 h. Results indicated that TNF-alpha increased caspase activities and resulted in a significant (p = 0.001) increase in bax/bcl-2 ratio. Stimulation with IL-10 did not alter caspase activities, while co-treatment with IL-10 and TNF-alpha inhibited TNF-alpha induced caspase activities and significantly (p > 0.004) impaired bax/bcl-2 ratio. At 24 h, mRNA levels for collagen type II, TNF-alpha and IL-10 were determined using real-time RT-PCR. Stimulation with TNF-alpha or TNF-alpha and IL-10 significantly inhibited collagen type II and increased IL-10 and TNF-alpha mRNA expression. IL-10 modulated the pro-apoptotic capacity of TNF-alpha in chondrocytes as shown by the decrease in caspase activities and bax/bcl-2 ratio compared to TNF-alpha stimulated chondrocytes, suggesting a mostly antagonistic interplay of IL-10 and TNF-alpha on mitochondrial apoptotic pathways.

Interleukin-18 induces apoptosis in human articular chondrocytes.

Elevated levels of the pro-inflammatory cytokine, interleukin-18 (IL-18) have recently been demonstrated in osteoarthritic cartilage. However, the effects of IL-18 on chondrocyte signalling and matrix biosynthesis are poorly understood. Therefore, the present study was undertaken to further characterize the impact of IL-18 on human articular chondrocyte in vitro. Human articular chondrocytes were stimulated with various concentrations of recombinant human IL-18 (1, 10, 100 ng/ml) for 0, 4, 8, 12, 24, 48, 72 h in vitro. The effects of IL-18 on the cartilage-specific matrix protein collagen type II, the cytoskeletal protein vinculin, the cell matrix signal transduction receptor beta-integrin, key signalling proteins of the MAPKinase pathway (such as SHC (Sarc Homology Collagen) and activated MAPKinase [ERK-1/-2]), the pro-inflammatory enzyme cyclo-oxygenase-2 (COX-2) and the apoptosis marker activated caspase-3 were evaluated by Western blot analysis and immunofluorescence labelling. Morphological features of IL-18 stimulated chondrocytes were estimated by transmission electron microscopy. IL-18 lead to inhibition of collagen type II-deposition, decreased beta-integrin receptor and vinculin synthesis, SHC and MAPKinase activation, increased COX-2 synthesis and activation of caspase-3 in chondrocytes in a time- and dose-dependent manner. Furthermore, chondrocytes treated with IL-18 exhibited typical morphological features of apoptosis as revealed by transmission electron microscopy. Taken together, the results of the present study underline key catabolic events mediated by IL-18 signalling in chondrocytes such as loss of cartilage-specific matrix and apoptosis. Inhibition of MAPKinase signalling is hypothesized to contribute to these features. Future therapeutics targeting IL-18 signalling pathways may be beneficial in rheumatoid arthritis and osteoarthritis therapy.

Adenoviral transduction is more efficient in alginate-derived chondrocytes than in monolayer chondrocytes.

Gene transfer into cultured chondrocytes by using adenoviral vectors has potential applications in treating cartilage disorders. The present study was undertaken to compare and optimize two chondrocyte culture conditions for adenoviral transduction efficacy by using primary human articular chondrocytes cultivated either directly in a monolayer condition or as outgrowths from alginate-stored chondrocyte cultures. Isolated primary chondrocytes from human articular cartilage were either immediately transduced with an EGFP (enhanced green fluorescent protein)-gene-bearing adenoviral vector (1,000 and 3,000 virus particles/cell) or cultured in alginate before transduction. Immunohistochemistry and flow cytometric analysis were employed to determine the expression of extracellular matrix proteins and of the alphavbeta5 integrin receptor involved in adenoviral cell entry. Monolayer chondrocytes exhibited moderate transduction rates (mean 22.2% and 46.9% EGFP-positive cells at 1,000 and 3,000 virus particles/cell by 72 h post-transduction), whereas alginate-derived chondrocytes revealed significantly higher transduction efficacies (95.7% and 99%). Both monolayer and alginate-derived chondrocytes expressed alphavbeta5 integrin, type II collagen and cartilage proteoglycans. The mean fluorescence intensity of type II collagen was significantly higher in the alginate-derived chondrocytes, whereas that of alphavbeta5 integrin was higher in the monolayer chondrocytes. Our results indicate that transduction efficacy is independent of alphavbeta5 integrin expression levels in chondrocytes. Moreover, adenoviral transduction of alginate-derived chondrocytes is more efficient than that for monolayer chondrocytes and may be a suitable tool to achieve sufficient numbers of transduced and differentiated chondrocytes for experimental applications and cartilage repair.

The NMDA receptor complex: a promising target for novel antiepileptic strategies.

Antiepileptic drugs (AEDs) cover a broad spectrum of pathological conditions ranging from seizures following congenital or acquired brain disorders to behavioural and psychiatric disorders and recently neuropathic pain. The need for novel antiepileptics raises from the expanding field of indications as well as from the fact, that special seizure types are refractory to common AEDs. In addition, many of the conventional antiepileptic drugs exhibit an unfavourable side-effect profile. Since there is growing evidence, that NMDA receptor activation might play a crucial role in epilepsy, NMDA receptor antagonists have become compounds of interest in preventing and treating seizures. This review focuses on NMDA receptor antagonistic compounds, which are already in use for the treatment of epileptic seizures (i. e. MgSO4, felbamate) and compounds in clinical trials (i. e. remacemide, ADCI). Further interest is put on NMDA antagonists in preclinical and biological testing (memantine, dizocilpine, conantokins, Co101244/PD174494, ifenprodil, arcaine, L-701,324, eliprodil, CGP40116, LY235959, LY233053, MRZ2/576, LU73068, 4-Cl-KYN). Some of the latter compounds are predominantely of academic interest (i. e. 4-Cl-KYN), others (i. e. dizocilpine, LY235959, LY233053) might be of therapeutical value when combined with conventional AEDs. In order to reduce adverse effects in antiepileptic medication using NMDA antagonists, special interest will be focused on subtype selective compounds. In this respect, Co101244, a novel potent and selective NR1/2B NMDA receptor antagonist might be a lead for therapeutically promising compounds.

Hyperhomocysteinemia enhances vascular inflammation and accelerates atherosclerosis in a murine model.

Although hyperhomocysteinemia (HHcy) is a well-known risk factor for the development of cardiovascular disease, the underlying molecular mechanisms are not fully elucidated. Here we show that induction of HHcy in apoE-null mice by a diet enriched in methionine but depleted in folate and vitamins B6 and B12 increased atherosclerotic lesion area and complexity, and enhanced expression of receptor for advanced glycation end products (RAGE), VCAM-1, tissue factor, and MMP-9 in the vasculature. These homocysteine-mediated (HC-mediated) effects were significantly suppressed, in parallel with decreased levels of plasma HC, upon dietary supplementation with folate and vitamins B6/B12. These findings implicate HHcy in atherosclerotic plaque progression and stability, and they suggest that dietary enrichment in vitamins essential for the metabolism of HC may impart protective effects in the vasculature.

Elevated plasma concentrations of lipoprotein(a) in medicated epileptic patients.

Lipoprotein(a) [Lp(a)] has been identified as an independent risk factor for vascular diseases. There are no data on Lp(a) levels in patients on long-term medication with carbamazepine, phenytoin, phenobarbital, or valproate. To investigate the effects of such treatment on Lp(a) levels and common carotid artery intima media thickness we studied 51 epileptic outpatients on long-term antiepileptic medication and 51 age-and sex-matched controls. Lp(a) levels above 45 mg/dl were found in 11 of 50 patients, but in only 4 of 51 controls (P < 0.05). The mean serum concentration of Lp(a) was 33.0+/-7.0 mg/dl in patients and 16.9+/-2.7 mg/dl in controls (P < 0.05). Epileptic patients also had a thicker intima media of the common carotid artery (0.79+/-0.04 mm) than controls (0.69+/-0.02 mm, P < 0.05) as measured by B-mode ultrasonography. Our results suggest an untoward effect of long-term antiepileptic medication on Lp(a) serum concentrations. Elevated Lp(a) levels might be a risk factor for arteriosclerosis in epileptic patients.

A novel series of 2-carboxytetrahydroquinolines provides new insights into the eastern region of glycine site NMDA antagonists.

A series of potent 4-substituted tetrahydroquinolines has been synthesized and biologically tested in order to refine the eastern region of the pharmacophore model for glycine site NMDA antagonists concerning the assessment of lipophilicity, flexibility, and hydrogen bonding. Displacement studies on rat cortical membranes using [3H]-5,7-dichlorokynurenic acid as a radioligand indicated that binding affinities are markedly enhanced when additional hydrogen-accepting groups are introduced into the eastern region of the 2-carboxytetrahydroquinolines. Among the most potent ligands were some urea, sulfonylurea, and crown ether compounds as interesting leads for new diagnostics, especially for the evaluation of PET tracers, which allow biodistribution studies and NMDA receptor studies in the living organism.

Benzimidazoles as NMDA glycine-site antagonists: study on the structural requirements in 2-position of the ligand.

A series of different substituted benzimidazole derivatives has been synthesized and evaluated for the ability to displace [3H]MDL-105,519 to rat cortical membranes. Two benzimidazole-2-carboxylic acids 9 b and 9 c, in this substitution pattern not yet described as glycine antagonists, showed IC50 values of 0.89 microM (9 b) and 38.0 microM (9 c). Replacement of the carboxylate function in 2-position by a sulfonic acid moiety appreciably increased solubility, but decreased the affinity giving evidence for the strong need of the carboxylate group within the ligand. Further structure-activity studies using benzimidazole-2-one derivatives with an acetic acid moiety adjacent to a ring nitrogen revealed new insights into the importance of amide functionalities within the heterocycle for the affinity of antagonist glycine-site ligands.

Probucol for treatment of hyperlipidemia in persistent childhood nephrotic syndrome. Report of a prospective uncontrolled multicenter study.

In a prospective, uncontrolled multicenter study, we have evaluated the effects of probucol on hyperlipidemia, proteinuria, and glomerular filtration rate (GFR) in hyperlipidemic children with persistent nephrotic syndrome. Probucol was started for a total of 12 weeks in 8 children and for 24 weeks in 14 children. Lipoprotein profiles, serum malondialdehyde (MDA) levels, proteinuria, renal function, and electrocardiogram were monitored every 4 weeks. Side effects were recorded by questionnaire. Treatment was completed by 7 of 8 patients for 12 weeks and by 7 of 14 children for 24 weeks. After 12 weeks, the mean serum concentrations of triglycerides (-15%), total cholesterol (-25%), very low-density lipoprotein-cholesterol (-27%), low-density lipoprotein-cholesterol (-23%), and high-density lipoprotein-cholesterol (-24%), as well as apolipoprotein (apo) A-I (-19%), apo B (-21%), and MDA (-32%) were reduced. The positive effects of probucol on the lipoprotein profile persisted over 24 weeks; however, there was no significant effect on either proteinuria or GFR. In conclusion, probucol had beneficial effects on lipoproteins and lipid peroxidation, but improved neither proteinuria nor GFR. The drug was generally tolerated well, but had to be discontinued because of a prolonged QT interval in 4 of 22 patients.