Strongly typed heterogeneous collections

A heterogeneous collection is a datatype that is capable of storing data of different types, while providing operations for look-up, update, iteration, and others. There are various kinds of heterogeneous collections, differing in representation, invariants, and access operations. We describe HList --- a Haskell library for strongly typed heterogeneous collections including extensible records. We illustrate HList's benefits in the context of type-safe database access in Haskell. The HList library relies on common extensions of Haskell 98. Our exploration raises interesting issues regarding Haskell's type system, in particular, avoidance of overlapping instances, and reification of type equality and type unificatio

Strongly typed heterogeneous collections

A heterogeneous collection is a datatype that is capable of storing data of different types, while providing operations for look-up, update, iteration, and others. There are various kinds of heterogeneous collections, differing in representation, invariants, and access operations. We describe HList --- a Haskell library for strongly typed heterogeneous collections including extensible records. We illustrate HList's benefits in the context of type-safe database access in Haskell. The HList library relies on common extensions of Haskell 98. Our exploration raises interesting issues regarding Haskell's type system, in particular, avoidance of overlapping instances, and reification of type equality and type unificatio

Effects for Efficiency: Asymptotic Speedup with First-Class Control

We study the fundamental efficiency of delimited control. Specifically, we show that effect handlers enable an asymptotic improvement in runtime complexity for a certain class of functions. We consider the generic count problem using a pure PCF-like base language $\lambda_b$ and its extension with effect handlers $\lambda_h$. We show that $\lambda_h$ admits an asymptotically more efficient implementation of generic count than any $\lambda_b$ implementation. We also show that this efficiency gap remains when $\lambda_b$ is extended with mutable state. To our knowledge this result is the first of its kind for control operators

Equivalence of Conventionally-Derived and Parthenote-Derived Human Embryonic Stem Cells

As human embryonic stem cell (hESC) lines can be derived via multiple means, it is important to determine particular characteristics of individual lines that may dictate the applications to which they are best suited. The objective of this work was to determine points of equivalence and differences between conventionally-derived hESC and parthenote-derived hESC lines (phESC) in the undifferentiated state and during neural differentiation.hESC and phESC were exposed to the same expansion conditions and subsequent neural and retinal pigmented epithelium (RPE) differentiation protocols. Growth rates and gross morphology were recorded during expansion. RTPCR for developmentally relevant genes and global DNA methylation profiling were used to compare gene expression and epigenetic characteristics. Parthenote lines proliferated more slowly than conventional hESC lines and yielded lower quantities of less mature differentiated cells in a neural progenitor cell (NPC) differentiation protocol. However, the cell lines performed similarly in a RPE differentiation protocol. The DNA methylation analysis showed similar general profiles, but the two cell types differed in methylation of imprinted genes. There were no major differences in gene expression between the lines before differentiation, but when differentiated into NPCs, the two cell types differed in expression of extracellular matrix (ECM) genes.These data show that hESC and phESC are similar in the undifferentiated state, and both cell types are capable of differentiation along neural lineages. The differences between the cell types, in proliferation and extent of differentiation, may be linked, in part, to the observed differences in ECM synthesis and methylation of imprinted genes

A Novel Function of Noc2 in Agonist-Induced Intracellular Ca2+ Increase during Zymogen-Granule Exocytosis in Pancreatic Acinar Cells

Noc2, a putative Rab effector, contributes to secretory-granule exocytosis in neuroendocrine and exocrine cells. Here, using two-photon excitation live-cell imaging, we investigated its role in Ca2+-dependent zymogen granule (ZG) exocytosis in pancreatic acinar cells from wild-type (WT) and Noc2-knockout (KO) mice. Imaging of a KO acinar cell revealed an expanded granular area, indicating ZG accumulation. In our spatiotemporal analysis of the ZG exocytosis induced by agonist (cholecystokinin or acetylcholine) stimulation, the location and rate of progress of ZG exocytosis did not differ significantly between the two strains. ZG exocytosis from KO acinar cells was seldom observed at physiological concentrations of agonists, but was normal (vs. WT) at high concentrations. Flash photolysis of a caged calcium compound confirmed the integrity of the fusion step of ZG exocytosis in KO acinar cells. The decreased ZG exocytosis present at physiological concentrations of agonists raised the possibility of impaired elicitation of calcium spikes. When calcium spikes were evoked in KO acinar cells by a high agonist concentration: (a) they always started at the apical portion and traveled to the basal portion, and (b) calcium oscillations over the 10 µM level were observed, as in WT acinar cells. At physiological concentrations of agonists, however, sufficient calcium spikes were not observed, suggesting an impaired [Ca2+]i-increase mechanism in KO acinar cells. We propose that in pancreatic acinar cells, Noc2 is not indispensable for the membrane fusion of ZG per se, but instead performs a novel function favoring agonist-induced physiological [Ca2+]i increases

Local Ca2+ Entry Via Orai1 Regulates Plasma Membrane Recruitment of TRPC1 and Controls Cytosolic Ca2+ Signals Required for Specific Cell Functions

Store-operated Ca2+ entry (SOCE) has been associated with two types of channels: CRAC channels that require Orai1 and STIM1 and SOC channels that involve TRPC1, Orai1, and STIM1. While TRPC1 significantly contributes to SOCE and SOC channel activity, abrogation of Orai1 function eliminates SOCE and activation of TRPC1. The critical role of Orai1 in activation of TRPC1-SOC channels following Ca2+ store depletion has not yet been established. Herein we report that TRPC1 and Orai1 are components of distinct channels. We show that TRPC1/Orai1/STIM1-dependent ISOC, activated in response to Ca2+ store depletion, is composed of TRPC1/STIM1-mediated non-selective cation current and Orai1/STIM1-mediated ICRAC; the latter is detected when TRPC1 function is suppressed by expression of shTRPC1 or a STIM1 mutant that lacks TRPC1 gating, STIM1(684EE685). In addition to gating TRPC1 and Orai1, STIM1 mediates the recruitment and association of the channels within ER/PM junctional domains, a critical step in TRPC1 activation. Importantly, we show that Ca2+ entry via Orai1 triggers plasma membrane insertion of TRPC1, which is prevented by blocking SOCE with 1 µM Gd3+, removal of extracellular Ca2+, knockdown of Orai1, or expression of dominant negative mutant Orai1 lacking a functional pore, Orai1-E106Q. In cells expressing another pore mutant of Orai1, Orai1-E106D, TRPC1 trafficking is supported in Ca2+-containing, but not Ca2+-free, medium. Consistent with this, ICRAC is activated in cells pretreated with thapsigargin in Ca2+-free medium while ISOC is activated in cells pretreated in Ca2+-containing medium. Significantly, TRPC1 function is required for sustained KCa activity and contributes to NFκB activation while Orai1 is sufficient for NFAT activation. Together, these findings reveal an as-yet unidentified function for Orai1 that explains the critical requirement of the channel in the activation of TRPC1 following Ca2+ store depletion. We suggest that coordinated regulation of the surface expression of TRPC1 by Orai1 and gating by STIM1 provides a mechanism for rapidly modulating and maintaining SOCE-generated Ca2+ signals. By recruiting ion channels and other signaling pathways, Orai1 and STIM1 concertedly impact a variety of critical cell functions that are initiated by SOCE

How ligand binds to the type 1 insulin-like growth factor receptor

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Пресепсин в диагностике нозокомиальной инфекции центральной нервной системы

ABSTRACT Introduction Nosocomial infection of the central nervous system (NI-CNS) is a serious complication in neurocritical patients that leads to deterioration of patient’s condition, worsening of outcomes and increased cost of treatment. The timely diagnosis of NI-CNS is a relevant problem and the search for new reliable markers of NI-CNS is an important issue.MATERIAL AND METHODS The prospective observational study consisted of two parts. The aim of the frst part was to defne normal ranges of cerebral spinal presepsin (CSF PSP). The aim of the second part was investigation of CSF PSP in neurocritical patients. We studied CSF sampling obtained during spinal anesthesia for elective urologic surgery in order to defne the normal CSF PSP. The following data was collected in neurocritical patients: CSF cell count, glucose, lactate, PSP, microbiological tests, polymerase chain reaction (PCR), when it was possible. Blood tests included complete blood count, C-reactive protein (CRP), procalcitonin (PCT), PSP. IBM SPSS Statistics (version 23.0) was used for statistical analysis.RESULTS Fifteen CSF samplings were obtained for investigation of normal CSF PSP ranges, which was 50–100 pg/ml. Nineteen neurocritical patients were included. Sixty-three pairs of CSF and blood samplings were obtained. All pairs were divided into the 4 groups in accordance with presence/absence of NI-CNS or systemic infection. In cases without both NI-CNS and systemic infection (group 4) CSF PSP was 406±203.1 pg/ml. In cases without NI-CNS and with systemic infection (group 2) CSF PSP was 614.9±315 pg/ml. In cases with NI-CNS and without systemic infection (group 3) CSF PSP was 547.8±264.3 pg/ml. In cases with both NI-CNS and systemic infection (group 1) CSF PSP was 731.1±389.7 pg/ml. The ROC analysis showed that in neurocritical patients without systemic infection CSF PSP 537 pg/ml meant NI-CNS with sensitivity 68.8% and specifcity 85.7%.CONCLUSION The normal value of the CSF PSP is 50-100 pg/ml. CSF PSP more than 537 pg/ml in neurocritical patients without systemic infection meant NI-CNS with 688% sensitivity and 857% specifcity. CSF PSP may be used for diagnosing NI-CNS in neurocritical patients as an additional marker only. CSF may be used as an additional diagnostic criterion, but further research is needed.ВВЕДЕНИЕ Нозокомиальная инфекция центральной нервной системы (НИ ЦНС) является тяжелым осложнением, приводящим к ухудшению состояния, удлинению продолжительности лечения и ухудшению исходов заболевания у нейрореанимационных пациентов. Ранняя диагностика НИ ЦНС является актуальной клинической задачей, а поиск новых надежных маркеров НИ ЦНС — важной научной целью.МАТЕРИАЛ И МЕТОДЫ Представленное исследование было проспективным и состояло из двух частей. Целью первой части было определить нормальный уровень пресепсина (ПСП) в спинномозговой жидкости (СМЖ). Для определения нормального уровня ПСП в СМЖ исследовались образцы ликвора, полученные при спинномозговой анестезии во время плановых урологических и общехирургических операций. Целью второй части было изучение динамики ПСП в СМЖ у различных групп нейрореанимационных пациентов в зависимости от наличия НИ ЦНС и системной инфекции. Вместе с ПСП в ликворе исследовали цитоз, уровень глюкозы, лактата, проводили его микробиологическое исследование и полимеразную цепную реакцию (ПЦР), когда это было возможно. Исследование крови включало в себя ее клинический анализ, определение содержания в ней С-реактивного белка (СРБ), прокальцитонина (PCT) и ПСП. Статистический анализ проводился с использованием IBM SPSS версии 23.0.РЕЗУЛЬТАТЫ В первой части исследования для получения нормального уровня ПСП в СМЖ были исследованы 15 проб СМЖ у пациентов урологического или общехирургического профиля без поражения нервной системы. Уровень ПСП в СМЖ составил 50–100 пг/мл. Эти значения были приняты в качестве референсных для уровня ПСП в СМЖ в норме. Во второй части исследования были проанализированы 63 пары проб ликвора и крови у 19 нейрореанимационных пациентов. Все пары были разделены на 4 группы в соответствии с наличием в момент забора ликвора и крови НИ ЦНС и системной инфекции. При наличии НИ ЦНС и системной инфекции (группа 1) уровень ПСП в СМЖ составил 731,1±389,7 пг/мл. При отсутствии НИ ЦНС и наличии системной инфекции (группа 2) уровень ПСП в СМЖ составил 614,9±315 пг/мл. При наличии НИ ЦНС и отсутствии системной инфекции (группа 3) уровень ПСП в СМЖ составил 547,8±264,3 пг/мл. При отсутствии НИ ЦНС и системной инфекции (группа 4) уровень ПСП в СМЖ составил 406±203,1 пг/мл. ROC-анализ показал, что уровень ПСП в СМЖ выше 537 пг/мл у нейрореанимационных пациентов без системной инфекции означает наличие НИ ЦНС с чувствительностью 68,8% и специфичностью 85,7%.ВЫВОДЫ В норме уровень пресепсина в ликворе составляет 50–100 пг/мл. Уровень пресепсина в ликворе выше 537 пг/мл у нейрореанимационного пациента без системной инфекции статистически значимо означает наличие у него НИ ЦНС. При диагностике НИ ЦНС определение уровня пресепсина в ликворе должно подлежать анализу вместе с традиционными маркерами инфекции ЦНС в качестве дополнительного маркера. Необходимо проведение дальнейших исследований

Disruption of the Autophagy-Lysosome Pathway Is Involved in Neuropathology of the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis

Variant late-infantile neuronal ceroid lipofuscinosis, a fatal lysosomal storage disorder accompanied by regional atrophy and pronounced neuron loss in the brain, is caused by mutations in the CLN6 gene. CLN6 is a non-glycosylated endoplasmic reticulum (ER)-resident membrane protein of unknown function. To investigate mechanisms contributing to neurodegeneration in CLN6 disease we examined the nclf mouse, a naturally occurring model of the human CLN6 disease. Prominent autofluorescent and electron-dense lysosomal storage material was found in cerebellar Purkinje cells, thalamus, hippocampus, olfactory bulb and in cortical layer II to V. Another prominent early feature of nclf pathogenesis was the localized astrocytosis that was evident in many brain regions and the more widespread microgliosis. Expression analysis of mutant Cln6 found in nclf mice demonstrated synthesis of a truncated protein with a reduced half-life. Whereas the rapid degradation of the mutant Cln6 protein can be inhibited by proteasomal inhibitors, there was no evidence for ER stress or activation of the unfolded protein response in various brain areas during postnatal development. Age-dependent increases in LC3-II, ubiquitinated proteins, and neuronal p62-positive aggregates were observed, indicating a disruption of the autophagy-lysosome degradation pathway of proteins in brains of nclf mice, most likely due to defective fusion between autophagosomes and lysosomes. These data suggest that proteasomal degradation of mutant Cln6 is sufficient to prevent the accumulation of misfolded Cln6 protein, whereas lysosomal dysfunction impairs constitutive autophagy promoting neurodegeneration