The influence of mechanical Circulatory support on post-transplant outcomes in pediatric patients: A multicenter study from the International Society for Heart and Lung Transplantation (ISHLT) Registry.

BACKGROUND: Mechanical circulatory support (MCS) is increasingly being used as a bridge to transplant in pediatric patients. We compare outcomes in pediatric patients bridged to transplant with MCS from an international cohort. METHODS: This retrospective cohort study of heart-transplant patients reported to the International Society for Heart and Lung Transplantation (ISHLT) registry from 2005-2017 includes 5,095 patients <18 years. Pretransplant MCS exposure and anatomic diagnosis were derived. Outcomes included mortality, renal failure, and stroke. RESULTS: 26% of patients received MCS prior to transplant: 240 (4.7%) on extracorporeal membrane oxygenation (ECMO), 1,030 (20.2%) on ventricular assist device (VAD), and 54 (1%) both. 29% of patients were <1 year, and 43.8% had congenital heart disease (CHD). After adjusting for clinical characteristics, compared to no-MCS and VAD, ECMO had higher mortality during their transplant hospitalization [OR 3.97 & 2.55; 95% CI 2.43-6.49 & 1.42-4.60] while VAD mortality was similar [OR 1.55; CI 0.99-2.45]. Outcomes of ECMO+VAD were similar to ECMO alone, including increased mortality during transplant hospitalization compared to no-MCS [OR 4.74; CI 1.81-12.36]. Patients with CHD on ECMO had increased 1 year, and 10 year mortality [HR 2.36; CI 1.65-3.39], [HR 1.82; CI 1.33-2.49]; there was no difference in survival in dilated cardiomyopathy (DCM) patients based on pretransplant MCS status. CONCLUSION: Survival in CHD and DCM is similar in patients with no MCS or VAD prior to transplant, while pretransplant ECMO use is strongly associated with mortality after transplant particularly in children with CHD. In children with DCM, long term survival was equivalent regardless of MCS status.

A meta-analysis of reversion mutations in BRCA genes identifies signatures of DNA end-joining repair mechanisms driving therapy resistance.

BACKGROUND: Germline mutations in the BRCA1 or BRCA2 (BRCA) genes predispose to hereditary breast and ovarian cancer and, mostly in the case of BRCA2, are also prevalent in cases of pancreatic and prostate malignancies. Tumours from these patients tend to lose both copies of the wild-type BRCA gene, which makes them exquisitely sensitive to platinum drugs and poly(ADP-ribose) polymerase inhibitors (PARPi), treatments of choice in these disease settings. Reversion secondary mutations with the capacity of restoring BRCA protein expression have been documented in the literature as bona fide mechanisms of resistance to these treatments. PATIENTS AND METHODS: We analysed published sequencing data of BRCA genes (from tumour or circulating tumour DNA) in 327 patients with tumours harbouring mutations in BRCA1 or BRCA2 (234 patients with ovarian cancer, 27 with breast cancer, 13 with pancreatic cancer, 11 with prostate cancer and 42 with a cancer of unknown origin) that progressed on platinum or PARPi treatment. RESULTS: We describe 269 cases of reversion mutations in 86 patients in this cohort (26.0%). Detailed analyses of the reversion events highlight that most amino acid sequences encoded by exon 11 in BRCA1 and BRCA2 are dispensable to generate resistance to platinum or PARPi, whereas other regions are more refractory to sizeable amino acid losses. They also underline the key role of mutagenic end-joining DNA repair pathways in generating reversions, especially in those affecting BRCA2, as indicated by the significant accumulation of DNA sequence microhomologies surrounding deletions leading to reversion events. CONCLUSIONS: Our analyses suggest that pharmacological inhibition of DNA end-joining repair pathways could improve durability of drug treatments by preventing the acquisition of reversion mutations in BRCA genes. They also highlight potential new therapeutic opportunities when reversions result in expression of hypomorphic versions of BRCA proteins, especially with agents targeting the response to DNA replication stress.

RAD51 foci as a functional biomarker of homologous recombination repair and PARP inhibitor resistance in germline BRCA-mutated breast cancer.

Background: BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity. Patients and methods: We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi. Results: RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor. Conclusion: Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.

Does the Presence of Scrapie Affect the Ability of Current Statutory Discriminatory Tests To Detect the Presence of Bovine Spongiform Encephalopathy?

Current European Commission (EC) surveillance regulations require discriminatory testing of all transmissible spongiform encephalopathy (TSE)-positive small ruminant (SR) samples in order to classify them as bovine spongiform encephalopathy (BSE) or non-BSE. This requires a range of tests, including characterization by bioassay in mouse models. Since 2005, naturally occurring BSE has been identified in two goats. It has also been demonstrated that more than one distinct TSE strain can coinfect a single animal in natural field situations. This study assesses the ability of the statutory methods as listed in the regulation to identify BSE in a blinded series of brain samples, in which ovine BSE and distinct isolates of scrapie are mixed at various ratios ranging from 99% to 1%. Additionally, these current statutory tests were compared with a new in vitro discriminatory method, which uses serial protein misfolding cyclic amplification (sPMCA). Western blotting consistently detected 50% BSE within a mixture, but at higher dilutions it had variable success. The enzyme-linked immunosorbent assay (ELISA) method consistently detected BSE only when it was present as 99% of the mixture, with variable success at higher dilutions. Bioassay and sPMCA reported BSE in all samples where it was present, down to 1%. sPMCA also consistently detected the presence of BSE in mixtures at 0.1%. While bioassay is the only validated method that allows comprehensive phenotypic characterization of an unknown TSE isolate, the sPMCA assay appears to offer a fast and cost-effective alternative for the screening of unknown isolates when the purpose of the investigation was solely to determine the presence or absence of BSE.

Micro-CT enables microlocalisation and quantification of Her2-targeted gold nanoparticles within tumour regions.

OBJECTIVES: Gold nanoparticles are of interest as potential in vivo diagnostic and therapeutic agents, as X-ray contrast agents, drug delivery vehicles and radiation enhancers. The aim of this study was to quantitatively determine their targeting and microlocalisation in mouse tumour models after intravenous injection by using micro-CT. METHODS: Gold nanoparticles (15 nm) were coated with polyethylene glycol and covalently coupled to anti-Her2 antibodies (Herceptin). In vitro, conjugates incubated with Her2+ (BT-474) and Her2- (MCF7) human breast cancer cells showed specific targeted binding with a Her2+ to Her2- gold ratio of 39.4±2.7:1. Nude mice, simultaneously bearing subcutaneous Her2+ and Her2- human breast tumours in opposite thighs were prepared. Gold nanoparticles alone, conjugated to Herceptin or to a non-specific antibody were compared. After intravenous injection of the gold nanoparticles, gold concentrations were determined by atomic absorption spectroscopy. Microlocalisation of gold was carried out by calibrated micro-CT, giving both the radiodensities and gold concentrations in tumour and non-tumour tissue. RESULTS: All gold nanoparticle constructs showed accumulation, predominantly at tumour peripheries. However, the Herceptin-gold nanoparticles showed the best specific uptake in their periphery (15.8±1.7% injected dose per gram), 1.6-fold higher than Her2- tumours and 22-fold higher than surrounding muscle. Imaging readily enabled detection of small, 1.5 mm-thick tumours. CONCLUSION: In this pre-clinical study, antibody-targeted 15 nm gold nanoparticles showed preferential uptake in cognate tumours, but even untargeted gold nanoparticles enhanced the visibility of tumour peripheries and enabled detection of millimetre-sized tumours. Micro-CT enabled quantification within various regions of a tumour.

Targeted cancer therapies based on the inhibition of DNA strand break repair.

Both DNA double- and single-strand break repair are highly coordinated processes utilizing signal transduction cascades and post-translational modifications such as phosphorylation, acetylation and ADP ribosylation. 'Drugable' targets within these networks have been identified that could potentially lead to novel therapeutic approaches within the oncology arena. Key regulators within these signalling cascades, such as DNA-dependent protein kinase, ataxia-telangiectasia mutated, checkpoint kinase 1 (CHK1), checkpoint kinase 2 (CHK2) and poly(ADP-ribose) polymerase, use either ATP or nicotinamide adenine dinucleotide for their enzymatic functions and are therefore readily accessible to small molecule inhibition at their catalytic sites. A range of highly potent and selective inhibitors of these DNA damage response pathways has now been identified through drug discovery efforts, with candidate molecules either approaching or already in clinical trials. This review will describe the small molecule inhibitors and drug discovery activities that focus on DNA break repair, along with the therapeutic rationale behind chemosensitization and the concept of synthetic lethality. We will also describe the emerging clinical data coming from this exciting new approach to targeted cancer therapy.

Premature twins of a mother with Graves' disease with discordant thyroid function: a case report.

Thyroid dysfunction is recognized in the newborns of mothers affected by Graves' disease during pregnancy. We describe the development of concurrent hyperthyroidism and hypothyroidism in the twin infants of a mother with Graves' disease diagnosed during pregnancy.

Duplication 8q22.1-q24.1 associated with bipolar disorder and speech delay.

OBJECTIVE: To report a case of a child with bipolar disorder found to have an unbalanced translocation involving the long arm of chromosome 8, a region that has been previously implicated in genome-wide linkage scans. CASE REPORT: A 7-year-old boy with a complex psychiatric symptom presentation including attention deficits, distractibility, impulsivity, pressured speech, sleep disturbance, aggressive behavior, and hypersexuality diagnosed with bipolar disorder. He also showed evidence of borderline intellectual and adaptive functioning and had mild dysmorphic features with a duplication of distal 8q that arose as an unbalanced chromosomal translocation due to a maternal 15p;8q insertion. CONCLUSION: This finding of an unbalanced translocation provides further evidence to support previous linkage studies of a potential causative gene on 8q for bipolar disorder.

Long term follow up of nasolacrimal intubation in adults.

BACKGROUND/AIMS: The authors have previously reported a short term mean 15 month follow up of nasolacrimal intubation in adults. The effectiveness of this procedure for long term (mean 78 months) control of epiphoria is assessed here. METHODS: 65 eyes from 40 patients who underwent nasolacrimal intubation were followed. Mean age at intubation was 59.2 years. The mean follow up period was 6.2 years. The results were based on long term symptomatic improvement. RESULTS: Complete long term resolution of symptoms was reported in 50.7%. A partial improvement was reported in 38.5%, and no improvement in 10.7%. A better outcome was associated with a canalicular than nasolacrimal duct obstruction. On long term follow up 16.9% required dacrocysto-rhinostomy (DCR). CONCLUSION: Nasolacrimal intubation, a minimally invasive procedure is successful in the long term control of epiphora. Selection of patients with canalicular duct obstruction gives higher success rates with fewer patients subsequently requiring the DCR procedure.

Association between variation in the human KCNJ10 potassium ion channel gene and seizure susceptibility.

PURPOSE: Our research program uses genetic linkage and association analysis to identify human seizure sensitivity and resistance alleles. Quantitative trait loci mapping in mice led to identification of genetic variation in the potassium ion channel gene Kcnj10, implicating it as a putative seizure susceptibility gene. The purpose of this work was to translate these animal model data to a human genetic association study. METHODS: We used single stranded conformation polymorphism (SSCP) electrophoresis, DNA sequencing and database searching (NCBI) to identify variation in the human KCNJ10 gene. Restriction fragment length polymorphism (RFLP) analysis, SSCP and Pyrosequencing were used to genotype a single nucleotide polymorphism (SNP, dbSNP rs#1130183) in KCNJ10 in epilepsy patients (n = 407) and unrelated controls (n = 284). The epilepsy group was comprised of patients with refractory mesial temporal lobe epilepsy (n = 153), childhood absence (n = 84), juvenile myoclonic (n = 111) and idiopathic generalized epilepsy not otherwise specified (IGE-NOS, n = 59) and all were of European ancestry. RESULTS: SNP rs#1130183 (C > T) alters amino acid 271 (of 379) from an arginine to a cysteine (R271C). The C allele (Arg) is common with conversion to the T allele (Cys) occurring twice as often in controls compared to epilepsy patients. Contingency analysis documented a statistically significant association between seizure resistance and allele frequency, Mantel-Haenszel chi square = 5.65, d.f. = 1, P = 0.017, odds ratio 0.52, 95% CI 0.33-0.82. CONCLUSION: The T allele of SNP rs#1130183 is associated with seizure resistance when common forms of focal and generalized epilepsy are analyzed as a group. These data suggest that this missense variation in KCNJ10 (or a nearby variation) is related to general seizure susceptibility in humans.

Mania following temporal lobectomy.

OBJECTIVE: To determine clinical and diagnostic variables that predict the development of mania after temporal lobectomy for treatment of refractory epilepsy. METHODS: From a large surgical database, 16 patients with new-onset mania after temporal lobectomy were identified. Mania patients were frequency matched for age, gender, and laterality of surgery to 16 temporal lobectomy patients with no postoperative mood disorder. These groups were compared on pre- and postoperative clinical and diagnostic data with each other and with 30 patients with depression after temporal lobectomy. Posthoc analyses compared mania and depression groups with the general surgical database matched for gender and laterality of surgery. RESULTS: Preoperative evaluations in postoperative mania patients, in particular EEG, were more likely to yield findings of brain dysfunction localizing to the hemisphere contralateral to temporal lobectomy. Right temporal lobectomy was more common in the postoperative mania group. Duration of manic episodes was usually transient, and all but one case remitted within 1 year after onset. In comparison with the control group, mania and depression groups had a higher likelihood for preoperative generalized tonic-clonic seizures and lack of seizure freedom following surgery. CONCLUSIONS: A limitation of this study was the relatively small number of patients. Despite this, clinical features that distinguish patients at risk for postoperative mania from those with depression and those with no psychiatric illness include bihemispheric abnormalities, in particular bitemporal EEG activity, and right temporal lobectomy.

RASTA: a distributed temporal abstraction system to facilitate knowledge-driven monitoring of clinical databases.

The time dimension is very important for applications that reason with clinical data. Unfortunately, this task is inherently computationally expensive. As clinical decision support systems tackle increasingly varied problems, they will increase the demands on the temporal reasoning component, which may lead to slow response times. This paper addresses this problem. It describes a temporal reasoning system called RASTA that uses a distributed algorithm that enables it to deal with large data sets. The algorithm also supports a variety of configuration options, enabling RASTA to deal with a range of application requirements.

Neurosurgical treatment of medically intractable status epilepticus.

Medically intractable status epilepticus can be defined as status epilepticus (SE) that persists or recurs despite medical treatment with intravenous agents that suppress cortical activity. We describe the successful neurosurgical treatment of three patients with medically intractable status epilepticus who responded either to focal resection, multiple subpial transection, or callosal section. The duration of medically intractable status epilepticus before surgery ranged between 23 and 42 days, and multiple medical complications occurred during the failed medical therapy. We suggest that patients with medically intractable status epilepticus who fail to respond to three courses of cerebral suppressant therapy for approximately 2 weeks be considered for surgical treatment in the absence of any known remitting etiology. Focal resection and/or subpial transection is preferred for intractable partial SE with focal electrographic changes or a focal lesion demonstrated by structural or functional neuroimaging. Corpus callosotomy may be used for patients with generalized or non-localizable intractable status epilepticus.

Lack of association between an interleukin 1 beta (IL-1beta) gene variation and refractory temporal lobe epilepsy.

PURPOSE: We attempted to confirm recent findings of Kanemoto et al. that demonstrated a positive association (p < 0.017) between a polymorphism in the promoter region of the interleukin 1-beta (IL-1beta) gene and the clinical phenotype of temporal lobe epilepsy with hippocampal sclerosis (TLE+HS). METHODS: We determined the frequency of this polymorphism in a group of 61 TLE+HS patients of European ancestry and compared it with that found in 119 ethnically matched control subjects. RESULTS: Analysis of genotype and allele frequencies showed no statistically significant difference in the distribution of the polymorphism between the two groups (p = 0.10). CONCLUSIONS: These data suggest that this IL-1beta promoter polymorphism does not act as a strong susceptibility factor for TLE+HS in a population of individuals of European ancestry.

Association of fear auras with mood and anxiety disorders after temporal lobectomy.

PURPOSE: Epilepsy has been associated with increased occurrence of behavioral disorders. Auras reflect abnormal stimulation of brain areas in close proximity to regions from which clinical seizures originate. The purpose of our study was to investigate whether fear auras are associated with a higher rate of mood and anxiety disorders before and 1 year after temporal lobectomy. METHODS: Twenty-two patients with fear auras were compared with matched groups with other auras and no auras. Neurologic and neuropsychological evaluations before, 1-2 months after, and 1 year after temporal lobectomy were reviewed for mood and anxiety disorders and psychotropic medication treatment. A logistic regression model examined effects of patient group and psychiatric status on postoperative psychiatric status. RESULTS: The majority of patients in the three groups experienced mood and anxiety disorders before surgery. Mood and anxiety disorders declined in the control, but not in the fear aura group after surgery. Presence of auras at 1 year after surgery was not related to psychiatric outcome. Postoperative mood and anxiety disorders were more common in patients with persistence of seizures and in those in the fear group who were seizure free. The minority of patients in all groups underwent psychotropic treatment before surgery, but the majority with fear auras underwent treatment after surgery. CONCLUSIONS: Postoperative mood and anxiety disorders were more common in fear aura patients after temporal lobectomy, in particular, if seizure free. Possible mechanisms include the role of the amygdala in fear conditioning, the concepts of forced normalization, and kindling.

Olfactory dysfunction in schizophrenia and temporal lobe epilepsy.

BACKGROUND: Schizophrenia and mesial temporal lobe epilepsy (TLE) represent two common brain disorders that share dysfunction of temporo-limbic neural substrates. OBJECTIVE: We evaluated whether patients with schizophrenia exhibited olfactory performance more similar to right or left temporal lobe epilepsy patients. METHODS: Odor identification ability and detection threshold sensitivity were measured in 40 patients with schizophrenia, 14 patients with right- and 18 patients with left-temporal lobe epilepsy (TLE) patients, and 25 healthy controls. Odor identification was assessed with the University of Pennsylvania Smell Identification Test (UPSIT) and odor detection threshold sensitivity with a single-staircase procedure using the stimulant phenyl ethyl alcohol (PEA). RESULTS: Relative to controls, only patients with schizophrenia and right TLE exhibited significant impairment in UPSIT performance. Left TLE patients and controls performed comparably on the UPSIT. Detection threshold sensitivity to PEA did not differ significantly among the four groups. CONCLUSIONS: These data suggest a greater reliance of olfactory processing on right hemisphere structures and are also consistent with recent neuroimaging studies that have implicated aberrant processing of olfactory information in right hemispheric brain regions in schizophrenia.

An experimental and computational study of 1,2-hydrogen migrations in 2-hydroxycyclopentylidene and its conjugate base.

Thermal decomposition of alpha-hydroxydiazirine 2 gives primarily cyclopentanone and some allylic alcohol, in similar amounts as the known cyclohexyl analogue 1. Calculations (B3LYP/6-31+G) also show cyclopentanone to be the major product of this carbene rearrangement. Diazirine 2 and the lithium salt of the corresponding conjugate base 3 were decomposed by photolysis. The proportion of ketone formed increases with deprotonation, a trend also found computationally. In comparison, the base-induced isomerization of cyclopentene oxide, which proceeds via alpha-elimination to a carbenoid intermediate similar to that obtained from 3, yields primarily allylic alcohol rather than ketone; neither ring size nor charge thus accounts for the unusual product distribution observed. Interestingly, the calculations reveal that in the gas phase with no counterion, the singlet, oxyanionic carbene, and the alpha-deprotonated epoxide are the same, rather than discrete structures. This intramolecular complexation stablilizes the oxyanionic carbene by 20-25 kcal/mol.

Representation of temporal indeterminacy in clinical databases.

Temporal indeterminancy is common in clinical medicine because the time of many clinical events is frequently not precisely known. Decision support systems that reason with clinical data may need to deal with this indeterminancy. This indeterminacy support must have a sound foundational model so that other system components may take advantage of it. In particular, it should operate in concert with temporal abstraction, a feature that is crucial in several clinical decision support systems that our group has developed. We have implemented a temporal query system called Tzolkin that provides extensive support for the temporal indeterminancies found in clinical medicine, and have integrated this support with our temporal abstraction mechanism. The resulting system provides a simple, yet powerful approach for dealing with temporal indeterminancy and temporal abstraction.

Prenatal alcohol exposure and depressive features in children.

BACKGROUND: This study examined the association between prenatal alcohol exposure and self-report of depressive symptoms in 5- to 6-year-old children. Higher levels of prenatal alcohol exposure were hypothesized to be associated with endorsement of a greater number of depressive symptoms in children. It was also hypothesized that maternal depression, although associated with drinking behavior, would contribute independently to outcome. Finally, the mother's behavior toward the child, as well as current drinking practices, were postulated to mediate the relationship between prenatal alcohol exposure and child depressive symptoms. METHODS: Participants were 41 mother-child dyads who had been followed longitudinally since the children were 1 year of age. Self-report questionnaires for maternal and child depression were used. RESULTS: Results revealed that prenatal alcohol exposure, maternal depression, and child gender seemed to be highly associated with child depressive symptoms. Girls who had higher levels of prenatal alcohol exposure and whose mothers acknowledged higher levels of depression endorsed the highest number of depressive symptoms. Neither the mother's behavior in interaction with the child nor her current level of alcohol consumption mediated the relationship. CONCLUSIONS: The importance of considering prenatal alcohol exposure as a risk variable in the prediction of childhood-onset depression and the possible neurological mechanisms underlying depression in children with alcohol exposure in utero are discussed.

Characterization of cultured microglia that can be infected by HIV-1.

Parenchymal microglia are targets of HIV infection. We, as well as others, have used in vitro microglia culture systems to study the tropism and replication of HIV. Characterization of perivascular and parenchymal microglia surface markers in vivo, in vitro, and ex vivo, has led to the understanding that these cell populations are different, and data from both the HIV and SIV models support the hypothesis that they may play different roles in infection of the CNS. We determined that human adult parenchymal microglia cultured from temporal lobe tissue for use in HIV replication studies, were CD11c+, CD45+, CD68+, CD14- when cultured with standard serum/cytokine-supplemented media. To determine the influence of serum and cytokines on HIV replication in microglia, we designed a new protocol for culturing microglia, and compared the results obtained with this protocol with the standard approach previously described. Microglia cultured in the presence of a 'feeder' layer of glial cells and in the absence of serum and cytokines expressed the same surface markers as pure microglia (>95%) cultured in supplemented media. However, pure microglia cultured in the absence of both serum/cytokines supplements and other glial cells, did not have characteristic microglial morphology and did not support HIV replication to as high a level. Lastly, we determined that unlike monocytes, ex vivo parenchymal microglia were capable of supporting HIV replication.