Evaluating threshold for donor fraction cell-free DNA using clinically available assay for rejection in pediatric and adult heart transplantation.

BACKGROUND: The aims of the study were to assess the performance of a clinically available cell-free DNA (cfDNA) assay in a large cohort of pediatric and adult heart transplant recipients and to evaluate performance at specific cut points in detection of rejection. METHODS: Observational, non-interventional, prospective study enrolled pediatric and adult heart transplant recipients from seven centers. Biopsy-associated plasma samples were used for cfDNA measurements. Pre-determined cut points were tested for analytic performance. RESULTS: A total of 487 samples from 160 subjects were used for the analysis. There were significant differences for df-cfDNA values between rejection [0.21% (IQR 0.12-0.69)] and healthy samples [0.05% (IQR 0.01-0.14), p < .0001]. The pediatric rejection group had a median df-cfDNA value of 0.93% (IQR 0.28-2.84) compared to 0.09% (IQR 0.04-0.23) for healthy samples, p = .005. Overall negative predictive value was 0.94 while it was 0.99 for pediatric patients. Cut points of 0.13% and 0.15% were tested for various types of rejection profiles and were appropriate to rule out rejection. CONCLUSION: The study suggests that pediatric patients with rejection show higher levels of circulating df-cfDNA compared to adults and supports the specific cut points for clinical use in pediatric and adult patients with overall acceptable performance.

Rare Congenital Upper Lip Pit.

Congenital lip pits are characterized by sinuses or fistulas in the lips that can occur in isolation or as part of a genetic disorder. A 6-year-old girl with a right upper lip lesion present at birth presented with recurrent swelling and occasional erythema. Examination revealed a mildly swollen punctum at the right upper wet/dry vermillion with expressible serous drainage. There were no other phenotypic or cognitive concerns. The lesion was surgically excised using vertical wedge resection. The postoperative course showed well well-healed incision. The pathology report confirmed a lip pit. The family was referred to genetics for further evaluation. Van der Woude syndrome (VWS) is a genetic disorder associated with abnormal development of the paramedian lip. Most congenital lip pits are primarily found on the lower lips, with paramedian lip pits being the most common. Upper lateral lip pits with or without accompanying lip pits are considerably rarer. Though VWS is commonly associated with mutations in the interferon regulatory factor 6 or grainyhead-like protein 3 genes, ~25% of affected individuals lack an identified genetic etiology. A high index of suspicion for VWS is warranted if lip pits are present in the absence of other phenotypic abnormalities and should prompt genetic testing for interferon regulatory factor 6 and grainyhead-like protein 3 mutations. Multidisciplinary teams should consider patient self-esteem, quality of life, and potential family planning when deciding on surgical intervention for lip pits. Surgical management of pits should entail tissue-preserving techniques such as vertical wedge resection and inverted T-lip reduction to prevent whistle-lip deformity.

Profibrotic COVID-19 subphenotype exhibits enhanced localized ER-dependent HSP47+ expression in cardiac myofibroblasts in situ.

We recently described a subgroup of autopsied COVID-19 subjects (∼40%), termed 'profibrotic phenotype,' who exhibited clusters of myofibroblasts (Mfbs), which were positive for the collagen-specific chaperone heat shock protein 47 (HSP47+) in situ. This report identifies increased, localized (hot spot restricted) expression of αSMA, COLα1, POSTN and FAP supporting the identity of HSP47+ cells as myofibroblasts and characterizing a profibrotic extracellular matrix (ECM) phenotype. Coupled with increased GRP78 in COVID-19 subjects, these data could reflect induction of the unfolded protein response for mitigation of proteostasis (i.e., protein homeostasis) dysfunction in discrete clusters of cells. ECM shifts in selected COVID-19 subjects occur without significant increases in either global trichrome positive staining or myocardial injury based quantitively on standard H&E scoring. Our findings also suggest distinct mechanism(s) for ECM remodeling in the setting of SARS-CoV-2 infection. The ratio of CD163+/CD68+ cells is increased in hot spots of profibrotic hearts compared with either controls or outside of hot spots in COVID-19 subjects. In sum, matrix remodeling of human COVID-19 hearts in situ is characterized by site-restricted profibrotic mediated (e.g., HSP47+ Mfbs, CD163+ Mφs) modifications in ECM (i.e., COLα1, POSTN, FAP), with a strong correlation between COLα1 and HSP47+cells within hot spots. Given the established associations of viral infection (e.g., human immunodeficiency virus; HIV), myocardial fibrosis and sudden cardiac death, early screening tools (e.g., plasma biomarkers, noninvasive cardiac magnetic resonance imaging) for diagnosis, monitoring and treatment of fibrotic ECM remodeling are warranted for COVID-19 high-risk populations.

Core Hippo pathway components act as a brake on Yap and Taz in the development and maintenance of the biliary network.

The development of the biliary system is a complex yet poorly understood process, with relevance to multiple diseases, including biliary atresia, choledochal cysts and gallbladder agenesis. We present here a crucial role for Hippo-Yap/Taz signaling in this context. Analysis of sav1 mutant zebrafish revealed dysplastic morphology and expansion of both intrahepatic and extrahepatic biliary cells, and ultimately larval lethality. Biliary dysgenesis, but not larval lethality, is driven primarily by Yap signaling. Re-expression of Sav1 protein in sav1-/- hepatocytes is able to overcome these initial deficits and allows sav1-/- fish to survive, suggesting cell non-autonomous signaling from hepatocytes. Examination of sav1-/- rescued adults reveals loss of gallbladder and formation of dysplastic cell masses expressing biliary markers, suggesting roles for Hippo signaling in extrahepatic biliary carcinomas. Deletion of stk3 revealed that the phenotypes observed in sav1 mutant fish function primarily through canonical Hippo signaling and supports a role for phosphatase PP2A, but also suggests Sav1 has functions in addition to facilitating Stk3 activity. Overall, this study defines a role for Hippo-Yap signaling in the maintenance of both intra- and extrahepatic biliary ducts.

A Protein Kinase C Phosphorylation Motif in GLUT1 Affects Glucose Transport and is Mutated in GLUT1 Deficiency Syndrome.

Protein kinase C has been implicated in the phosphorylation of the erythrocyte/brain glucose transporter, GLUT1, without a clear understanding of the site(s) of phosphorylation and the possible effects on glucose transport. Through in vitro kinase assays, mass spectrometry, and phosphospecific antibodies, we identify serine 226 in GLUT1 as a PKC phosphorylation site. Phosphorylation of S226 is required for the rapid increase in glucose uptake and enhanced cell surface localization of GLUT1 induced by the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Endogenous GLUT1 is phosphorylated on S226 in primary endothelial cells in response to TPA or VEGF. Several naturally occurring, pathogenic mutations that cause GLUT1 deficiency syndrome disrupt this PKC phosphomotif, impair the phosphorylation of S226 in vitro, and block TPA-mediated increases in glucose uptake. We demonstrate that the phosphorylation of GLUT1 on S226 regulates glucose transport and propose that this modification is important in the physiological regulation of glucose transport.

Increase in nuclear cell-free DNA is associated with major adverse events in adult and pediatric heart transplant recipients.

BACKGROUND: Cell-free DNA is an emerging biomarker. While donor fraction may detect graft events in heart transplant recipients, the prognostic value of total nuclear cell-free DNA (ncfDNA) itself is largely unexplored. OBJECTIVE: Explore the relationship between ncfDNA and clinical events in heart transplant recipients. METHODS: We conducted a multi-center prospective study to investigate the value of cell-free DNA in non-invasive monitoring following heart transplantation. Over 4000 blood samples were collected from 388 heart transplant patients. Total ncfDNA and donor fraction were quantified. Generalized linear models with maximum likelihood estimation for repeated measures with subjects as clusters were used to explore the relationship of ncfDNA and major adverse events. Receiver operating characteristic curves were used to help choose cutpoints. RESULTS: A ncfDNA threshold (50 ng/ml) was identified that was associated with increased risk of major adverse events. NcfDNA was elevated in patients who suffered cardiac arrest, required mechanical circulatory support or died post heart transplantation as well as in patients undergoing treatment for infection. CONCLUSIONS: Elevated ncfDNA correlates with risk for major adverse events in adult and pediatric heart transplant recipients and may indicate a need for enhanced surveillance after transplant.

Relationship between donor fraction cell-free DNA and clinical rejection in heart transplantation.

BACKGROUND: Clinical rejection (CR) defined as decision to treat clinically suspected rejection with change in immunotherapy based on clinical presentation with or without diagnostic biopsy findings is an important part of care in heart transplantation. We sought to assess the utility of donor fraction cell-free DNA (DF cfDNA) in CR and the utility of serial DF cfDNA in CR patients in predicting outcomes of clinical interest. METHODS: Patients with heart transplantation were enrolled in two sequential, multi-center, prospective observational studies. Blood samples were collected for surveillance or clinical events. Clinicians were blinded to the results of DF cfDNA. RESULTS: A total of 835 samples from 269 subjects (57% pediatric) were included for this analysis, including 28 samples associated with CR were analyzed. Median DF cfDNA was 0.43 (IQR 0.15, 1.36)% for CR and 0.10 (IQR 0.07, 0.16)% for healthy controls (p < .0001). At cutoff value of 0.13%, the area under curve (AUC) was 0.82, sensitivity of 0.86, specificity of 0.67, and negative predictive value of 0.99. There was serial decline in DF cfDNA post-therapy, however, those with cardiovascular events (cardiac arrest, need for mechanical support or death) showed significantly higher levels of DF cfDNA on Day 0 (2.11 vs 0.31%) and Day 14 (0.51 vs 0.22%) compared to those who did not have such an event (p < .0001). CONCLUSION: DF cfDNA has excellent agreement with clinical rejection and, importantly, serial measurement of DF cfDNA predict clinically significant outcomes post treatment for rejection in these patients.

Adverse Maternal Environment and Postweaning Western Diet Alter Hepatic CD36 Expression and Methylation Concurrently with Nonalcoholic Fatty Liver Disease in Mouse Offspring.

BACKGROUND: The role of an adverse maternal environment (AME) in conjunction with a postweaning Western diet (WD) in the development of nonalcoholic fatty liver disease (NAFLD) in adult offspring has not been explored. Likewise, the molecular mechanisms associated with AME-induced NAFLD have not been studied. The fatty acid translocase or cluster of differentiation 36 (CD36) has been implicated to play a causal role in the pathogenesis of WD-induced steatosis. However, it is unknown if CD36 plays a role in AME-induced NAFLD. OBJECTIVE: This study was designed to evaluate the isolated and additive impact of AME and postweaning WD on the expression and DNA methylation of hepatic Cd36 in association with the development of NAFLD in a novel mouse model. METHODS: AME constituted maternal WD and maternal stress, whereas the control (Con) group had neither. Female C57BL/6J mice were fed a WD [40% fat energy, 29.1% sucrose energy, and 0.15% cholesterol (wt/wt)] 5 wk prior to pregnancy and throughout lactation. Non invasive variable stressors (random frequent cage changing, limited bedding, novel object, etc.) were applied to WD dams during the last third of pregnancy to produce an AME. Con dams consumed the control diet (CD) (10% fat energy, no sucrose or cholesterol) and were not exposed to stress. Male offspring were weaned onto either CD or WD, creating 4 experimental groups: Con-CD, Con-WD, AME-CD, and AME-WD, and evaluated for metabolic and molecular parameters at 120 d of age. RESULTS: AME and postweaning WD independently and additively increased the development of hepatic steatosis in adult male offspring. AME and WD independently and additively upregulated hepatic CD36 protein and mRNA expression and hypomethylated promoters 2 and 3 of the Cd36 gene. CONCLUSIONS: Using a mouse AME model together with postweaning WD, this study demonstrates a role for CD36 in AME-induced NAFLD in offspring and reveals 2 regions of environmentally induced epigenetic heterogeneity within Cd36.

α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease.

Fabry disease is an X-linked lysosomal storage disease caused by α-galactosidase A (α-Gal A) deficiency. Kidney and heart failure are frequent complications in adulthood and greatly contribute to patient morbidity and mortality. Because α-Gal A-deficient mouse models do not recapitulate cardiorenal findings observed in patients, a nonmouse model may be beneficial to our understanding of disease pathogenesis. In this study, we evaluated disease processes in a recently generated Fabry rat model. We found that male Fabry rats weighed significantly less than wild-type (WT) males, whereas female Fabry rats weighed significantly more than WT females. Whereas no difference in female survival was detected, we observed that male Fabry rats had a decreased lifespan. Skin histology revealed that inflammation and lipoatrophy may be chief disease mediators in patients. With respect to the kidney and heart, we found that both organs accumulate α-Gal A substrates, including the established biomarkers, globotriaosylceramide and globotriaosylsphingosine. Longitudinal serum and urine chemistry panels demonstrated pronounced renal tubule dysfunction, which was confirmed histologically. Mitral valve thickening was observed in Fabry rats using echocardiography. We conclude that Fabry rats recapitulate important kidney and heart phenotypes experienced by patients and can be further used to study disease mechanisms and test therapies.-Miller, J. J., Aoki, K., Mascari, C. A., Beltrame, A. K., Sokumbi, O., North, P. E., Tiemeyer, M., Kriegel, A. J., Dahms, N. M., α-Galactosidase A-deficient rats accumulate glycosphingolipids and develop cardiorenal phenotypes of Fabry disease.

Early changes in cell-free DNA levels in newly transplanted heart transplant patients.

Heart transplantation is a well-established therapy for end-stage heart failure in children and young adults. The highest risk of graft loss occurs in the first 60 days post-transplant. Donor fraction of cell-free DNA is a highly sensitive marker of graft injury. Changes in cell-free DNA levels have not previously been studied in depth in patients early after heart transplant. A prospective study was conducted among heart transplant recipients at a single pediatric heart center. Blood samples were collected from children and young adult transplant patients at three time points within 10 days of transplantation. DF and total cell-free DNA levels were measured using a targeted method (myTAIHEART ). In 17 patients with serial post-transplant samples, DF peaks in the first 2 days after transplant (3.5%, [1.9-10]%) and then declines toward baseline (0.27%, [0.19-0.52]%) by 6-9 days. There were 4 deaths in the first year among the 10 patients with complete sample sets, and 3 out of 4 who died had a late rise or blunted decline in donor fraction. Patients who died trended toward an elevated total cell-free DNA at 1 week (41.5, [34-65] vs 13.6, [6.2-22] P = .07). Donor fraction peaks early after heart transplant and then declines toward baseline. Patients without sustained decline in donor fraction and/or elevated total cell-free DNA at 1 week may have worse outcomes.

Mapping genetic modifiers of radiation-induced cardiotoxicity to rat chromosome 3.

Radiation therapy is used in ~50% of cancer patients to reduce the risk of recurrence and in some cases improve survival. Despite these benefits, doses can be limited by toxicity in multiple organs, including the heart. The underlying causes and biomarkers of radiation-induced cardiotoxicity are currently unknown, prompting the need for experimental models with inherent differences in sensitivity and resistance to the development of radiation-induced cardiotoxicity. We have identified the parental SS (Dahl salt-sensitive/Mcwi) rat strain to be a highly-sensitized model of radiation-induced cardiotoxicity. In comparison, substitution of rat chromosome 3 from the resistant BN (Brown Norway) rat strain onto the SS background (SS-3BN consomic) significantly attenuated radiation-induced cardiotoxicity. SS-3BN rats had less radiation-induced cardiotoxicity than SS rats, as measured by survival, pleural and pericardial effusions, echocardiogram parameters, and histological damage. Mast cells, previously shown to have predominantly protective roles in radiation-induced cardiotoxicity, were increased in the more resistant SS-3BN hearts postradiation. RNA sequencing from SS and SS-3BN hearts at 1 wk postradiation revealed 5,098 differentially expressed candidate genes across the transcriptome and 350 differentially expressed genes on rat chromosome 3, which coincided with enrichment of multiple pathways, including mitochondrial dysfunction, sirtuin signaling, and ubiquitination. Upstream regulators of enriched pathways included the oxidative stress modulating transcription factor, Nrf2, which is located on rat chromosome 3. Nrf2 target genes were also differentially expressed in the SS vs. SS-3BN consomic hearts postradiation. Collectively, these data confirm the existence of heritable modifiers in radiation-induced cardiotoxicity and provide multiple biomarkers, pathways, and candidate genes for future analyses. NEW & NOTEWORTHY This novel study reveals that heritable genetic factors have the potential to modify normal tissue sensitivity to radiation. Gene variant(s) on rat chromosome 3 can contribute to enhanced cardiotoxicity displayed in the SS rats vs. the BN and SS-3BN consomic rats. Identifying genes that lead to understanding the mechanisms of radiation-induced cardiotoxicity represents a novel method to personalize radiation treatment, as well as predict the development of radiation-induced cardiotoxicity.

Multifocal congenital hemangioma: Expanding the pathogenesis of "neonatal hemangiomatosis".

Congenital hemangiomas are benign vascular tumors, categorized by their postnatal behavior as rapidly involuting, non-involuting, or partially involuting. They are typically solitary, with a predilection for the head or limbs near a joint. We present two infants with small, multifocal congenital nonprogressive hemangiomas of the skin, one associated with hepatic and intracranial lesions, and another with an in utero intracranial hemorrhage and hydrocephalus. These cases further extend the differential diagnosis of congenital multifocal vascular lesions or "hemangiomatosis."

Protective role of Trpc6 knockout in the progression of diabetic kidney disease.

Diabetic kidney disease (DKD) is a chronic kidney pathology that leads to end-stage renal disease. Previous studies from our laboratory indicate that there is an association between the development of DKD and the transient receptor potential canonical 6 (TRPC6) channel. Trpc6 expression and activity were increased in the streptozotocin (STZ)-treated Dahl Salt-sensitive (Dahl SS) rat, an established model of type 1 diabetes. Here, using a Trpc6 knockout created on the Dahl SS rat background (SSTrpc6-/-), we test the hypothesis that the absence of Trpc6 will protect podocytes and kidney function during the development of DKD. Four groups of animals (control SSWT, SSTrpc6-/-, STZ-treated SSWT, and STZ-SSTrpc6-/-) were utilized in this study. Diabetes development was monitored for 11 wk after STZ injection with periodic weight, glucose, and urinary output measurements. There was an increase in albuminuria and glomerular injury following STZ treatment, which was not different between Dahl SS and SSTrpc6-/- groups. Western blot analysis revealed elevated levels of nephrin in urine samples of STZ-SSWT rats, which was higher compared with STZ-SSTrpc6-/- rats. Furthermore, pathological increases in basal [Ca2+]i levels and foot process damage of podocytes during the development of DKD was attenuated in the STZ-SSTrpc6-/- compared with STZ-SSWT rats. Overall, our data indicate that TRPC6 channel inhibition may have at least partial renoprotective effects, which could lead to the development of new pharmacological tools to treat or prevent the progression of DKD.

Nogo-B receptor deficiency causes cerebral vasculature defects during embryonic development in mice.

Nogo-B receptor (NgBR) was identified as a receptor specific for Nogo-B. Our previous work has shown that Nogo-B and its receptor (NgBR) are essential for chemotaxis and morphogenesis of endothelial cells in vitro and intersomitic vessel formation via Akt pathway in zebrafish. Here, we further demonstrated the roles of NgBR in regulating vasculature development in mouse embryo and primitive blood vessel formation in embryoid body culture systems, respectively. Our results showed that NgBR homozygous knockout mice are embryonically lethal at E7.5 or earlier, and Tie2Cre-mediated endothelial cell-specific NgBR knockout (NgBR ecKO) mice die at E11.5 and have severe blood vessel assembly defects in embryo. In addition, mutant embryos exhibit dilation of cerebral blood vessel, resulting in thin-walled endothelial caverns. The similar vascular defects also were detected in Cdh5(PAC)-CreERT2 NgBR inducible ecKO mice. Murine NgBR gene-targeting embryonic stem cells (ESC) were generated by homologous recombination approaches. Homozygous knockout of NgBR in ESC results in cell apoptosis. Heterozygous knockout of NgBR does not affect ESC cell survival, but reduces the formation and branching of primitive blood vessels in embryoid body culture systems. Mechanistically, NgBR knockdown not only decreases both Nogo-B and VEGF-stimulated endothelial cell migration by abolishing Akt phosphorylation, but also decreases the expression of CCM1 and CCM2 proteins. Furthermore, we performed immunofluorescence (IF) staining of NgBR in human cerebral cavernous malformation patient tissue sections. The quantitative analysis results showed that NgBR expression levels in CD31 positive endothelial cells is significantly decreased in patient tissue sections. These results suggest that NgBR may be one of important genes coordinating the cerebral vasculature development.

Vascular Actions of Angiotensin 1-7 in the Human Microcirculation: Novel Role for Telomerase.

OBJECTIVE: This study examined vascular actions of angiotensin 1-7 (ANG 1-7) in human atrial and adipose arterioles. APPROACH AND RESULTS: The endothelium-derived hyperpolarizing factor of flow-mediated dilation (FMD) switches from antiproliferative nitric oxide (NO) to proatherosclerotic hydrogen peroxide in arterioles from humans with coronary artery disease (CAD). Given the known vasoprotective properties of ANG 1-7, we tested the hypothesis that overnight ANG 1-7 treatment restores the NO component of FMD in arterioles from patients with CAD. Endothelial telomerase activity is essential for preserving the NO component of vasodilation in the human microcirculation; thus, we also tested whether telomerase activity was necessary for ANG 1-7-mediated vasoprotection by treating separate arterioles with ANG 1-7±the telomerase inhibitor 2-[[(2E)-3-(2-naphthalenyl)-1-oxo-2-butenyl1-yl]amino]benzoic acid. ANG 1-7 dilated arterioles from patients without CAD, whereas dilation was significantly reduced in arterioles from patients with CAD. In atrial arterioles from patients with CAD incubated with ANG 1-7 overnight, the NO synthase inhibitor NG-nitro-l-arginine methyl ester abolished FMD, whereas the hydrogen peroxide scavenger polyethylene glycol catalase had no effect. Conversely, in vessels incubated with ANG 1-7+2-[[(2E)-3-(2-naphthalenyl)-1-oxo-2-butenyl1-yl]amino]benzoic acid, NG-nitro-l-arginine methyl ester had no effect on FMD, but polyethylene glycol catalase abolished dilation. In cultured human coronary artery endothelial cells, ANG 1-7 significantly increased telomerase activity. These results indicate that ANG 1-7 dilates human microvessels, and dilation is abrogated in the presence of CAD. Furthermore, ANG 1-7 treatment is sufficient to restore the NO component of FMD in arterioles from patients with CAD in a telomerase-dependent manner. CONCLUSIONS: ANG 1-7 exerts vasoprotection in the human microvasculature via modulation of telomerase activity.

Mimickers of Infantile Hemangiomas.

Infantile hemangiomas (IHs) are the most common tumors of infancy and usually follow a typical course of growth and involution. We report four soft tissue tumors that were referred to the pediatric dermatology clinic as IHs and the process by which they were diagnosed and treated. Clinicians should be aware of presentations of these uncommon, but serious soft tissue tumors. Many of these mimickers have a vastly different clinical prognosis, and early intervention to limit sequelae is crucial. Biopsy of atypical lesions should be considered early in the diagnostic process since they have varied prognosis and treatment strategies.

Sturge-Weber syndrome and port-wine stains caused by somatic mutation in GNAQ.

BACKGROUND: The Sturge-Weber syndrome is a sporadic congenital neurocutaneous disorder characterized by a port-wine stain affecting the skin in the distribution of the ophthalmic branch of the trigeminal nerve, abnormal capillary venous vessels in the leptomeninges of the brain and choroid, glaucoma, seizures, stroke, and intellectual disability. It has been hypothesized that somatic mosaic mutations disrupting vascular development cause both the Sturge-Weber syndrome and port-wine stains, and the severity and extent of presentation are determined by the developmental time point at which the mutations occurred. To date, no such mutation has been identified. METHODS: We performed whole-genome sequencing of DNA from paired samples of visibly affected and normal tissue from 3 persons with the Sturge-Weber syndrome. We tested for the presence of a somatic mosaic mutation in 97 samples from 50 persons with the Sturge-Weber syndrome, a port-wine stain, or neither (controls), using amplicon sequencing and SNaPshot assays, and investigated the effects of the mutation on downstream signaling, using phosphorylation-specific antibodies for relevant effectors and a luciferase reporter assay. RESULTS: We identified a nonsynonymous single-nucleotide variant (c.548G→A, p.Arg183Gln) in GNAQ in samples of affected tissue from 88% of the participants (23 of 26) with the Sturge-Weber syndrome and from 92% of the participants (12 of 13) with apparently nonsyndromic port-wine stains, but not in any of the samples of affected tissue from 4 participants with an unrelated cerebrovascular malformation or in any of the samples from the 6 controls. The prevalence of the mutant allele in affected tissues ranged from 1.0 to 18.1%. Extracellular signal-regulated kinase activity was modestly increased during transgenic expression of mutant Gαq. CONCLUSIONS: The Sturge-Weber syndrome and port-wine stains are caused by a somatic activating mutation in GNAQ. This finding confirms a long-standing hypothesis. (Funded by the National Institutes of Health and Hunter's Dream for a Cure Foundation.).

Venous malformation of the ethmoid and sphenoid sinuses.

OBJECTIVES: The aim of this study was to present a rare case of a venous malformation that occupied the ethmoid and sphenoid sinuses. Prior to resection, it was believed to be a hemangioma. METHODS: This study includes a case report and review of the literature. CONCLUSION: There is often confusion between "hemangiomas" and "vascular malformations," but they are important to differentiate because they have unique approaches to treatment. Venous malformations in the paranasal sinuses are very rare. To our knowledge, this is the first case report that explicitly describes a venous malformation in the ethmoid and sphenoid sinuses. It was treated using endoscopic sinus surgery with intraoperative computer-assisted stereotactic navigation.

Heparin rescues factor V Leiden-associated placental failure independent of anticoagulation in a murine high-risk pregnancy model.

Low molecular weight heparin (LMWH) is being tested as an experimental drug for improving pregnancy outcome in women with inherited thrombophilia and placenta-mediated pregnancy complications, such as recurrent pregnancy loss. The role of thrombotic processes in these disorders remains unproven, and the issue of antithrombotic prophylaxis is intensely debated. Using a murine model of factor V Leiden-associated placental failure, we show that treatment of the mother with LMWH allows placental development to proceed and affords significant protection from fetal loss. Nonetheless, the therapeutic effect of LMWH is not replicated by anticoagulation; fondaparinux and a direct Xa inhibitor, C921-78, achieve anticoagulation similar to LMWH but produce little or no improvement in pregnancy outcome. Genetic attenuation of maternal platelet aggregation is similarly ineffective. In contrast, even a partial loss of thrombin sensitivity of maternal platelets protects pregnancies. Neonates born from these pregnancies are growth retarded, suggesting that placental function is only partially restored. The placentae are smaller but do not reveal any evidence of thrombosis. Our data demonstrate an anticoagulation-independent role of LMWH in protecting pregnancies and provide evidence against the involvement of thrombotic processes in thrombophilia-associated placental failure. Importantly, thrombin-mediated maternal platelet activation remains central in the mechanism of placental failure.