Search

Kosaki overgrowth syndrome is a recently described syndrome characterized by distinctive facial features, brain white matter lesions, and developmental delay. Germline activating heterozygous PDGFRB mutations have been reported in this condition. Systemic connective tissue-type findings have been described in some individuals. We describe a 19-year-old Caucasian female with a history of hydrocephalus, Dandy-Walker malformation, cervical spine arachnoid cyst, progressive scoliosis, and overgrowth. Her physical exam included distinctive craniofacial dysmorphism, as well as soft and hyperextensible skin. Cardiovascular imaging during adolescence revealed saccular aneurysms in both coronary artery systems and subtle tortuosity of the cervical vertebral arteries. Exome sequencing trio analysis identified a de novo previously reported pathogenic variant in PDGFRB, c.1696T>C (p.[Trp566Arg]). Further functional studies included platelet-derived growth factor cellular metabolic pathway activity that confirmed the variant causes a constitutive activation of the PI3K-AKT pathway. This is the first report to characterize the activating nature of this PDGFRB variant. We also highlight the connective tissue findings seen in Kosaki overgrowth syndrome and recommend baseline echocardiographic evaluation in all individuals with this condition with particular emphasis on coronary arteries.

Background In ecology, population density is a key feature of community analysis. Yet in studies of the gut microbiome, bacterial density is rarely reported. Studies of hospitalized patients commonly use rectal swabs for microbiome analysis, yet variation in their bacterial density—and the clinical and methodologic significance of this variation—remains undetermined. We used an ultra-sensitive quantification approach—droplet digital PCR (ddPCR)—to quantify bacterial density in rectal swabs from 118 hospitalized patients. We compared bacterial density with bacterial community composition (via 16S rRNA amplicon sequencing) and clinical data to determine if variation in bacterial density has methodological, clinical, and prognostic significance. Results Bacterial density in rectal swab specimens was highly variable, spanning five orders of magnitude (1.2 × 104–3.2 × 109 16S rRNA gene copies/sample). Low bacterial density was strongly correlated with the detection of sequencing contamination (Spearman ρ = − 0.95, p < 10−16). Low-density rectal swab communities were dominated by peri-rectal skin bacteria and sequencing contaminants (p < 0.01), suggesting that some variation in bacterial density is explained by sampling variation. Yet bacterial density was also associated with important clinical exposures, conditions, and outcomes. Bacterial density was lower among patients who had received piperacillin-tazobactam (p = 0.017) and increased among patients with multiple medical comorbidities (Charlson score, p = 0.0040) and advanced age (p = 0.043). Bacterial density at the time of hospital admission was independently associated with subsequent extraintestinal infection (p = 0.0028), even when controlled for severity of illness and comorbidities. Conclusions The bacterial density of rectal swabs is highly variable, and this variability is of methodological, clinical, and prognostic significance. Microbiome studies using rectal swabs are vulnerable to sequencing contamination and should include appropriate negative sequencing controls. Among hospitalized patients, gut bacterial density is associated with clinical exposures (antibiotics, comorbidities) and independently predicts infection risk. Bacterial density is an important and under-studied feature of gut microbiome community analysis.

The Centers for Disease Control and Prevention estimates that VRE causes an estimated 54,000 infections and 539 million dollars in attributable health care costs annually. Despite improvements in hand washing, environmental cleaning, and antibiotic use, VRE is still prevalent in many hospitals. There is a pressing need to better understand the processes by which patients acquire VRE. Multiple lines of evidence suggest that intestinal microbiota may help some patients resist VRE acquisition. In this large case-control study, we compared the 16S profile of intestinal microbiota on admission in patients that did and did not subsequently acquire VRE. The 16S profile did not predict subsequent VRE acquisition, in part due to rapid and dramatic change in the gut microbiome following hospitalization. However, Blautia spp. present on admission predicted decreased Enterococcus abundance after VRE acquisition, and Lactobacillus spp. present on admission predicted Enterococcus dominance after VRE acquisition. Thus, VRE acquisition and domination may be distinct processes., Vancomycin-resistant Enterococcus (VRE) is a leading cause of hospital-acquired infections and continues to spread despite widespread implementation of pathogen-targeted control guidelines. Commensal gut microbiota provide colonization resistance to VRE, but the role of gut microbiota in VRE acquisition in at-risk patients is unknown. To address this gap in our understanding, we performed a case-control study of gut microbiota in hospitalized patients who did (cases) and did not (controls) acquire VRE. We matched case subjects to control subjects by known risk factors and “time at risk,” defined as the time elapsed between admission until positive VRE screen. We characterized gut bacterial communities using 16S rRNA gene amplicon sequencing of rectal swab specimens. We analyzed 236 samples from 59 matched case-control pairs. At baseline, case and control subjects did not differ in gut microbiota when measured by community diversity (P = 0.33) or composition (P = 0.30). After hospitalization, gut communities of cases and controls differed only in the abundance of the Enterococcus-containing operational taxonomic unit (OTU), with the gut microbiota of case subjects having more of this OTU than time-matched control subjects (P = 0.01). Otherwise, case and control communities after the time at risk did not differ in diversity (P = 0.33) or community structure (P = 0.12). Among patients who became VRE colonized, those having the Blautia-containing OTU on admission had lower Enterococcus relative abundance once colonized (P = 0.004). Our results demonstrate that the 16S profile of the gut microbiome does not predict VRE acquisition in hospitalized patients, likely due to rapid and profound microbiota change. The gut microbiome does not predict VRE acquisition, but it may be associated with Enterococcus expansion, suggesting that these should be considered two distinct processes. IMPORTANCE The Centers for Disease Control and Prevention estimates that VRE causes an estimated 54,000 infections and 539 million dollars in attributable health care costs annually. Despite improvements in hand washing, environmental cleaning, and antibiotic use, VRE is still prevalent in many hospitals. There is a pressing need to better understand the processes by which patients acquire VRE. Multiple lines of evidence suggest that intestinal microbiota may help some patients resist VRE acquisition. In this large case-control study, we compared the 16S profile of intestinal microbiota on admission in patients that did and did not subsequently acquire VRE. The 16S profile did not predict subsequent VRE acquisition, in part due to rapid and dramatic change in the gut microbiome following hospitalization. However, Blautia spp. present on admission predicted decreased Enterococcus abundance after VRE acquisition, and Lactobacillus spp. present on admission predicted Enterococcus dominance after VRE acquisition. Thus, VRE acquisition and domination may be distinct processes.

The few studies evaluating data on resource utilisation following the Fontan operation specifically are outdated. We sought to evaluate resource utilisation and factors associated with increased resource use after the Fontan operation in a contemporary, large, multi-institutional cohort. This retrospective cohort study of children who had the Fontan between January, 2004 and June, 2013 used the Pediatric Health Information Systems Database. Generalised linear regression analyses evaluated factors associated with resource use. Of 2187 Fontan patients included in the study, 62% were males. The median age at Fontan was 3.2 years (inter-quartile range (IQR): 2.6–3.8). The median length of stay following the Fontan was 9 days (IQR: 7–14). The median costs and charges in 2012 dollars for the Fontan operation were $93,900 (IQR: $67,800–$136,100) and $156,000 (IQR: $112,080–$225,607), respectively. Postoperative Fontan mortality (30 days) was 1% (n=21). Factors associated with increased resource utilisation included baseline and demographic factors such as region, race, and renal anomaly, factors at the bidirectional Glenn such as seizures, valvuloplasty, and surgical volume, number of admissions between the bidirectional Glenn and the Fontan, and factors at the Fontan such as surgical volume and age at Fontan. The most strongly associated factors for both increased Fontan length of stay and increased Fontan charges were number of bidirectional Glenn to Fontan admissions (p

Supraventricular tachycardia (SVT), the most common fetal tachycardia, can be difficult to manage in utero. We sought to better understand predictors of the postnatal clinical course in neonates who experienced fetal SVT. We hypothesized that fetuses with hydrops or those with refractory SVT (failure of first-line SVT therapy) are more likely to experience postnatal SVT. This was a retrospective multicenter cohort study of subjects diagnosed with fetal SVT between 2006 and 2014. Fetuses with structural heart disease were excluded. Descriptive comparative statistics and univariate analysis with logistic regression were utilized to determine factors that most strongly predicted postnatal SVT and preterm delivery. The cohort consisted of 103 subjects. Refractory SVT was found in 37% (N = 38) of the cohort with this group more likely to be delivered prematurely (median = 36 vs. 37.5 weeks, p = 0.04). Refractory SVT did not increase the risk of postnatal SVT (p = 0.09). Postnatal SVT was seen in 61% (N = 63). Of those, 68% (N = 43) had postnatal SVT at ≤2 days of age. Postnatal SVT was associated with a later fetal SVT diagnosis (median = 30 vs. 27.5 weeks, p = 0.006). We found a strong correlation between postnatal SVT and later gestational age at fetal SVT diagnosis. Subjects with refractory SVT or hydrops did not have a higher risk of postnatal SVT. We propose strong consideration for term delivery in the absence of significant clinical compromise. Further studies to assess whether outcomes vary for preterm delivery versus expectant management in those with refractory SVT should be performed.

Supraventricular tachycardia (SVT) is the most common arrhythmia in the fetus and can be difficult to manage in utero. Recognizing that preterm birth before 37 weeks gestation is the most common catastrophic complication of pregnancy, we sought to better understand the pre and postnatal clinical

During the development of indazolylpyrimidines as novel and potent inhibitors of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR2) tyrosine kinase, we observed that some human tumour xenografts are more sensitive to VEGFR2 kinase inhibitors than others. A better understanding of the basis for this differential response may help to identify a predictive marker that would greatly aid in the identification of a suitable patient population for treatment. One representative compound from the indazolylpyrimidine series is GW654652 that inhibited all three VEGFRs with similar potency. The inhibition of VEGFR2 kinase by GW654652 was about 150 to8800 more potent than the inhibition of eight other kinases tested. GW654652 inhibited VEGF- and bFGF-induced proliferation in endothelial cells with an IC(50) of 110 and 1980 nM, respectively, and has good pharmacokinetic profile in mouse and dog. We investigated the association between VEGF and VEGFR2 expression and the antitumour efficacy of GW654652, in various xenograft models. Statistically significant associations were observed between the antitumour efficacy of GW654652 in xenografts and VEGF protein (P=0.005) and VEGFR2 expression (P=0.041). The oral dose of GW654652 producing 50% inhibition of tumour growth (ED(50)) decreased with increasing levels of VEGF (r=-0.94); and, in contrast, the ED(50) increased with the increased expression of VEGFR2 (r=0.82). These results are consistent with the observed inverse correlation between VEGF and VEGFR2 expression in tumours. These findings support the hypothesis that VEGF and VEGFR2 expression by tumours may predict the therapeutic outcome of VEGFR kinase inhibitors.

Introduction: We sought to determine factors associated with length of stay (LOS) and cost of the Fontan surgery in a contemporary large multi-institutional cohort. Hypothesis: Independent and modifiable risk factors associated with longer LOS and higher cost will be identified. Methods: We performed a retrospective cohort study of Fontan surgey (1/2004 - 7/2013) using the Pediatric Health Information Systems (PHIS) database (40 US children’s hospitals). Outcome parameters were LOS and costs at Fontan surgery. Predictor variables were demographics (race, insurance, region, rural vs city, commute time, surgical volume), cardiac and other diagnoses, Glenn events, readmission between Glenn and Fontan, and age at Glenn and Fontan. Following a stepwise selection procedure, significant predictors of LOS and cost were included in a generalized linear model with the appropriate inverse Gaussian distribution and the log link function with LOS and cost (adjusted to 2012 $ and region) as the dependent variable. Results: For the 2187 patients (62% male) who had Fontan surgery, the median age at surgery was 1146 days (IQR: 943-1369) and at Glenn was 165 days (IQR: 133-208). Following Fontan, the median ICU LOS was 3 days (IQR: 2-6) and total LOS was 9 days (IQR: 7-14). The median total hospital cost was $93, 900 (IQR: 67,800-136,100). Post-operative mortality was 1% (N=21). Region, insurance, race, surgical volume were the predominant factors associated with both cost and LOS (Table 1). Conclusion: This is the largest multicenter contemporary study describing the factors (particularly healthcare delivery factors) associated with resource utilization during the Fontan hospitalization. Health care delivery variables dominated the factors predicting increased resource utilization. Changes in health care policy should target health care delivery risk factors (race, region, insurance, driving distance, surgical volume) to reduce cost in this resource intensive population.

Aniline ‘headgroups’ were synthesized and incorporated into an alkynyl thienopyrimidine series of EGFR and ErbB-2 inhibitors. Potent inhibition of enzyme activity and cellular proliferation was observed. In certain instances, protein binding was reduced and oral exposure was found to be somewhat improved relative to compounds containing the reference aniline.

Inhibition of the vascular endothelial growth factor (VEGF) signaling pathway has emerged as one of the most promising new approaches for cancer therapy. We describe herein the key steps starting from an initial screening hit leading to the discovery of pazopanib, N(4)-(2,3-dimethyl-2H-indazol-6-yl)-N(4)-methyl-N(2)-(4-methyl-3-sulfonamidophenyl)-2,4-pyrimidinediamine, a potent pan-VEGF receptor (VEGFR) inhibitor under clinical development for renal-cell cancer and other solid tumors.

Esters and amides undergo reduction to the corresponding aldehydes using DIBAL-H followed by same pot conversion to terminal alkynes utilizing the Bestmann–Ohira reagent in good to excellent yields. Additionally chiral nonracemic substrates undergo this transformation with complete preservation of stereochemical integrity.