Mode of administration influences plasma levels of active Centella asiatica compounds in 5xFAD mice while markers of neuroinflammation remain unaltered

Introduction

A water extract of Centella asiatica (L.) Urban [Apiaceae] (CAW) has demonstrated cognitive-enhancing effects in mouse models of Alzheimer's disease and aging, the magnitude of which is influenced by whether CAW is delivered in the drinking water or the diet. These cognitive benefits are accompanied by improvements in oxidative stress and mitochondrial function in the brain, two pathways related to the neuroinflammatory response. The effect of CAW on neuroinflammation, however, has not been directly studied. Here, we investigated the effect of CAW on neuroinflammation in 5xFAD mice and compared plasma levels of CAW's active compounds following two modes of CAW administration.

Methods

Eight-to-nine-month-old male and female 5xFAD mice and their wild-type littermates were administered CAW in their diet or drinking water (0 or 1,000 mg/kg/day) for five weeks. Immunohistochemistry was performed for β-amyloid (Aβ), glial fibrillary acidic protein (GFAP), and Griffonia simplicifolia lectin I (GSL I) in the cortex and hippocampus. Gene expression of inflammatory mediators (IL-6, TNFα, IL-1β, TREM2, AIF1, CX3CR1, CX3CL1, CD36, C3AR1, RAGE, CCR6, CD3E) was measured in the deep grey matter.

Results

CAW decreased cortical Aβ plaque burden in female 5xFAD mice administered CAW in the drinking water but had no effect on Aβ plaques in other treatment groups. CAW did not impact elevated levels of GFAP or GSL I in 5xFAD mice, regardless of sex, brain region, or mode of CAW administration. In the deep grey matter, CAW increased C3AR1 expression in 5xFAD females administered CAW in the drinking water and decreased IL-1β expression in 5xFAD males administered CAW in the diet. CAW had no effect, however, on gene expression levels of any other inflammatory mediator in the deep grey, for either sex or mode of CAW administration. Mice administered CAW in the drinking water versus the diet had significantly higher plasma levels of CAW compounds.

Discussion

CAW had little impact on the neuroinflammatory markers selected for evaluation in the present study, suggesting that the cognitive benefits of CAW may not be mediated by an anti-inflammatory effect or that additional molecular markers are needed to fully characterize the effect of CAW on neuroinflammation.

The novel estrogen receptor modulator STX attenuates Amyloid-β neurotoxicity in the 5XFAD mouse model of Alzheimer's disease

Based on previous evidence that the non-steroidal estrogen receptor modulator STX mitigates the effects of neurotoxic Amyloid-β (Aβ) in vitro, we have evaluated its neuroprotective benefits in a mouse model of Alzheimer's disease. Cohorts of 5XFAD mice, which begin to accumulate cerebral Aβ at two months of age, were treated with orally-administered STX starting at 6 months of age for two months. After behavioral testing to evaluate cognitive function, biochemical and immunohistochemical assays were used to analyze key markers of mitochondrial function and synaptic integrity. Oral STX treatment attenuated Aβ-associated mitochondrial toxicity and synaptic toxicity in the brain, as previously documented in cultured neurons. STX also moderately improved spatial memory in 5XFAD mice. In addition, STX reduced markers for reactive astrocytosis and microgliosis surrounding amyloid plaques, and also unexpectedly reduced overall levels of cerebral Aβ in the brain. The neuroprotective effects of STX were more robust in females than in males. These results suggest that STX may have therapeutic potential in Alzheimer's Disease.

Copper Modulation and Memory Impairment due to Hippocampal Tau Pathology

Background:Environmental copper has been implicated in the pathogenesis of Alzheimer’s disease based on evidence that: 1) brain copper levels increase with age, 2) copper promotes misfolding and toxicity of amyloid-β in vitro, 3) copper-modulating interventions reduce amyloid pathology in animal models. However, the effect of copper upon non-amyloid Alzheimer’s pathology is relatively under-explored.Objective:To determine if modulation of brain copper level affects brain tau pathology and/or associated cognitive impairment.Methods:We tested the hypothesis that brain copper modulates tau pathology by manipulating brain levels of copper in the PS19 transgenic mouse model of tau pathology. We treated PS19 and wild-type mice with oral zinc acetate, an established therapy for long term control of excess brain copper, and examined treatment effects upon brain copper, brain tau, NFT-like pathology, and spatial memory. We treated a second cohort of mice with exogenous dietary copper in order to evaluate whether excess environmental copper promotes brain tau pathology.Results:Copper-lowering with oral zinc attenuated spatial memory impairment in female but not male PS19 mice, without a significant effect upon tau pathology. Copper loading increased brain copper, but did not have an effect on brain tau pathology or spatial memory function.Conclusion:These findings suggest that a strategy to lower brain copper may be viable for symptomatic benefit in the setting of tau neuropathology, but unlikely to have robust effects on the underlying pathology. These findings are consistent with dietary or other exogenous copper being unlikely to promote tau pathology.

Age-Associated DNA Methylation Patterns Are Shared Between the Hippocampus and Peripheral Blood Cells

As the population ages, interest in identifying biomarkers of healthy aging and developing antiaging interventions has increased. DNA methylation has emerged as a potentially powerful molecular marker of aging. Methylation changes at specific sites in the human genome that have been identified in peripheral blood have been used as robust estimators of chronological age. Similar age-related DNA methylation signatures are also seen in various tissue types in rodents. However, whether these peripheral alterations in methylation status reflect changes that also occur in the central nervous system remains unknown. This study begins to address this issue by identifying age-related methylation patterns in the hippocampus and blood of young and old mice. Reduced-representation bisulfite sequencing (RBSS) was used to identify differentially methylated regions (DMRs) in the blood and hippocampus of 2- and 20-month-old C57/Bl6 mice. Of the thousands of DMRs identified genome-wide only five were both found in gene promoters and significantly changed in the same direction with age in both tissues. We analyzed the hippocampal expression of these five hypermethylated genes and found that three were expressed at significantly lower levels in aged mice [suppressor of fused homolog (Sufu), nitric oxide synthase 1 (Nos1) and tripartite motif containing 2 (Trim2)]. We also identified several transcription factor binding motifs common to both hippocampus and blood that were enriched in the DMRs. Overall, our findings suggest that some age-related methylation changes that occur in the brain are also evident in the blood and could have significant translational relevance.

Centella Asiatica Improves Memory and Promotes Antioxidative Signaling in 5XFAD Mice

Centella asiatica (CA) herb is a traditional medicine, long reputed to provide cognitive benefits. We have reported that CA water extract (CAW) treatment improves cognitive function of aged Alzheimer’s disease (AD) model Tg2576 and wild-type (WT) mice, and induces an NRF2-regulated antioxidant response in aged WT mice. Here, CAW was administered to AD model 5XFAD female and male mice and WT littermates (age: 7.6 +/− 0.6 months), and object recall and contextual fear memory were tested after three weeks treatment. CAW’s impact on amyloid-β plaque burden, and markers of neuronal oxidative stress and synaptic density, was assessed after five weeks treatment. CAW antioxidant activity was evaluated via nuclear transcription factor (erythroid-derived 2)-like 2 (NRF2) and NRF2-regulated antioxidant response element gene expression. Memory improvement in both genders and genotypes was associated with dose-dependent CAW treatment without affecting plaque burden, and marginally increased synaptic density markers in the hippocampus and prefrontal cortex. CAW treatment increased Nrf2 in hippocampus and other NRF2 targets (heme oxygenase-1, NAD(P)H quinone dehydrogenase 1, glutamate-cysteine ligase catalytic subunit). Reduced plaque-associated SOD1, an indicator of oxidative stress, was observed in the hippocampi and cortices of CAW-treated 5XFAD mice. We postulate that CAW treatment leads to reduced oxidative stress, contributing to improved neuronal health and cognition.

Open chemistry: RESTful web APIs, JSON, NWChem and the modern web application

An end-to-end platform for chemical science research has been developed that integrates data from computational and experimental approaches through a modern web-based interface. The platform offers an interactive visualization and analytics environment that functions well on mobile, laptop and desktop devices. It offers pragmatic solutions to ensure that large and complex data sets are more accessible. Existing desktop applications/frameworks were extended to integrate with high-performance computing resources, and offer command-line tools to automate interaction-connecting distributed teams to this software platform on their own terms. The platform was developed openly, and all source code hosted on the GitHub platform with automated deployment possible using Ansible coupled with standard Ubuntu-based machine images deployed to cloud machines. The platform is designed to enable teams to reap the benefits of the connected web-going beyond what conventional search and analytics platforms offer in this area. It also has the goal of offering federated instances, that can be customized to the sites/research performed. Data gets stored using JSON, extending upon previous approaches using XML, building structures that support computational chemistry calculations. These structures were developed to make it easy to process data across different languages, and send data to a JavaScript-based web client.

Centella asiatica attenuates Aβ-induced neurodegenerative spine loss and dendritic simplification

The medicinal plant Centella asiatica has long been used to improve memory and cognitive function. We have previously shown that a water extract from the plant (CAW) is neuroprotective against the deleterious cognitive effects of amyloid-β (Aβ) exposure in a mouse model of Alzheimer's disease, and improves learning and memory in healthy aged mice as well. This study explores the physiological underpinnings of those effects by examining how CAW, as well as chemical compounds found within the extract, modulate synaptic health in Aβ-exposed neurons. Hippocampal neurons from amyloid precursor protein over-expressing Tg2576 mice and their wild-type (WT) littermates were used to investigate the effect of CAW and various compounds found within the extract on Aβ-induced dendritic simplification and synaptic loss. CAW enhanced arborization and spine densities in WT neurons and prevented the diminished outgrowth of dendrites and loss of spines caused by Aβ exposure in Tg2576 neurons. Triterpene compounds present in CAW were found to similarly improve arborization although they did not affect spine density. In contrast caffeoylquinic acid (CQA) compounds from CAW were able to modulate both of these endpoints, although there was specificity as to which CQAs mediated which effect. These data suggest that CAW, and several of the compounds found therein, can improve dendritic arborization and synaptic differentiation in the context of Aβ exposure which may underlie the cognitive improvement observed in response to the extract in vivo. Additionally, since CAW, and its constituent compounds, also improved these endpoints in WT neurons, these results may point to a broader therapeutic utility of the extract beyond Alzheimer's disease.

Centella asiatica modulates antioxidant and mitochondrial pathways and improves cognitive function in mice

ETHNOPHARMACOLOGICAL RELEVANCE

This study investigates the cognitive enhancing effects of the plant Centella asiatica which is widely used Ayurvedic and traditional Chinese medicine.

AIM OF THE STUDY

The goal of this study was to determine the effects of a water extract of the medicinal plant Centella asiatica (CAW) on cognitive ability as well as mitochondrial and antioxidant response pathways in vivo.

MATERIALS AND METHODS

Old and young C57BL/6 mice were treated with CAW (2mg/mL) in their drinking water. Learning and memory was assessed using Morris Water Maze (MWM) and then tissue was collected and gene expression analyzed.

RESULTS

CAW improved performance in the MWM in aged animals and had a modest effect on the performance of young animals. CAW also increased the expression of mitochondrial and antioxidant response genes in the brain and liver of both young and old animals. Expression of synaptic markers was also increased in the hippocampus and frontal cortex, but not in the cerebellum of CAW-treated animals.

CONCLUSIONS

These data indicate a cognitive enhancing effect of CAW in healthy mice. The gene expression changes caused by CAW suggest a possible effect on mitochondrial biogenesis, which in conjunction with activation of antioxidant response genes could contribute to cognitive improvement.

Oral zinc reduces amyloid burden in Tg2576 mice

The aggregation of amyloid-β in Alzheimer's disease can be affected by free transition metals such as copper and zinc in the brain. Addition of copper and zinc with amyloid acts to increase aggregation and copper additionally promotes the formation of reactive oxygen species. We propose that reduction of brain copper by blocking uptake of copper from the diet is a viable strategy to regulate the formation of insoluble amyloid-β in the brain of Tg2576 mice. Mice were treated with regimens of zinc acetate, which acts with metallothionein to block copper uptake in the gut, at various times along their lifespan to model prevention and treatment paradigms. We found that the mice tolerated zinc acetate well over the six month course of study. While we did not observe significant changes in cognition and behavior, there was a reduction in insoluble amyloid-β in the brain. This observation coincided with a reduction in brain copper and interestingly no change in brain zinc. Our findings show that blocking copper uptake from the diet can redistribute copper from the brain and reduce amyloid-β aggregation.

Activity of striatal neurons reflects social action and own reward

Social interactions provide agents with the opportunity to earn higher benefits than when acting alone and contribute to evolutionary stable strategies. A basic requirement for engaging in beneficial social interactions is to recognize the actor whose movement results in reward. Despite the recent interest in the neural basis of social interactions, the neurophysiological mechanisms identifying the actor in social reward situations are unknown. A brain structure well suited for exploring this issue is the striatum, which plays a role in movement, reward, and goal-directed behavior. In humans, the striatum is involved in social processes related to reward inequity, donations to charity, and observational learning. We studied the neurophysiology of social action for reward in rhesus monkeys performing a reward-giving task. The behavioral data showed that the animals distinguished between their own and the conspecific's reward and knew which individual acted. Striatal neurons coded primarily own reward but rarely other's reward. Importantly, the activations occurred preferentially, and in approximately similar fractions, when either the own or the conspecific's action was followed by own reward. Other striatal neurons showed social action coding without reward. Some of the social action coding disappeared when the conspecific's role was simulated by a computer, confirming a social rather than observational relationship. These findings demonstrate a role of striatal neurons in identifying the social actor and own reward in a social setting. These processes may provide basic building blocks underlying the brain's function in social interactions.

Nonlinear model structure design and construction using orthogonal least squares and D-optimality design

A very efficient learning algorithm for model subset selection is introduced based on a new composite cost function that simultaneously optimizes the model approximation ability and model robustness and adequacy. The derived model parameters are estimated via forward orthogonal least squares, but the model subset selection cost function includes a D-optimality design criterion that maximizes the determinant of the design matrix of the subset to ensure the model robustness, adequacy, and parsimony of the final model. The proposed approach is based on the forward orthogonal least square (OLS) algorithm, such that new D-optimality-based cost function is constructed based on the orthogonalization process to gain computational advantages and hence to maintain the inherent advantage of computational efficiency associated with the conventional forward OLS approach. Illustrative examples are included to demonstrate the effectiveness of the new approach.

Case series: 2q33.1 microdeletion syndrome--further delineation of the phenotype

Recurrent deletions of 2q32q33 have recently been reported as a new microdeletion syndrome, clinical features of which include significant learning difficulties, growth retardation, dysmorphic features, thin and sparse hair, feeding difficulties, and cleft or high palate. Haploinsufficiency of one gene within the deleted region, SATB2, has been suggested to be responsible for most of the features of the syndrome. This article describes seven previously unreported patients with deletions at 2q33.1, all partially overlapping the previously described critical region for the 2q33.1 microdeletion syndrome. The deletions ranged in size from 35 kb to 10.4 Mb, with the smallest deletion entirely within the SATB2 gene. Patients demonstrated significant developmental delay and challenging behaviour, a particular behavioural phenotype that seems to be emerging with more reported patients with this condition. One patient in this cohort has a deletion entirely within SATB2 and has a cleft palate, whereas several patients with larger deletions have a high arched palate. In addition, one other patient has significant orthopaedic problems with ligamentous laxity. Interestingly, this patient has a deletion that lies just distal to SATB2. The orthopaedic problems have not been reported previously and are possibly an additional feature of this syndrome. Overall, this report provides further evidence that the SATB2 gene is the critical gene in this microdeletion syndrome. In addition, because the individuals in this study range in age from 3-19 years, these patients will help define the natural progression of the phenotype in patients with this microdeletion.

A copper-lowering strategy attenuates amyloid pathology in a transgenic mouse model of Alzheimer's disease

There is increasing evidence for the crucial role of metals in the pathology of Alzheimer's disease. Both the aggregation and neurotoxicity of amyloid-β are dependent on the presence of copper. This study investigated the ability of the copper-complexing drug tetrathiomolybdate to reduce amyloid-β pathology and spatial memory impairment in both a prevention and a treatment paradigm in the Tg2576 mouse model of Alzheimer's disease. Tetrathiomolybdate treatment lowered brain copper and reduced amyloid-β levels in the prevention paradigm, but not in the treatment paradigm. Our data suggests that controlled lowering of systemic copper may achieve anti-amyloid effects if initiated early in the disease process.

CCR6: a biomarker for Alzheimer's-like disease in a triple transgenic mouse model

The inflammatory status of the brain in patients as well as animal models of Alzheimer's disease (AD) has been extensively studied. Accumulation of activated microglia producing tumor necrosis factor-α and monocyte chemotactic protein-1 contribute to the pathology of the disease. However, little is known about the changes in the spleen and associated peripheral immunity that might contribute to AD pathology. The goal of this study was to characterize phenotypic and functional changes in spleen, blood and brain cell populations that contribute to development of an AD-like disease in a triple transgenic (3xTg-AD) mouse model. The 3xTg-AD mice had increased percentages of brain Gr-1+ granulocytes, dendritic cells and macrophages, spleen and blood derived CD8+Ly6C+ memory T cells and CCR6+ B cells, as well as increased levels of secreted interleukin-6. Brain tissue from older 12 month old symptomatic 3xTg-AD female mice exhibited highly elevated mRNA expression of CCR6 compared to wild-type mice. Importantly, this pronounced increase in expression of CCR6 was also detected in brain and spleen tissue from pre-symptomatic 5--6 month old 3xTg-AD females and males. Our data demonstrate increased expression of CCR6 in the brain and peripheral immune organs of both pre-symptomatic and symptomatic 3xTg-AD mice, strongly suggesting an ongoing inflammatory process that precedes onset of clinical AD-like disease.

Clinical laboratory practices for the detection of rotavirus in England and Wales: can surveillance based on routine laboratory testing data be used to evaluate the impact of vaccination?

Two rotavirus vaccines have recently been licensed in Europe. Rotavirus surveillance data in many European countries are based on reports of laboratory-confirmed rotavirus infections. If surveillance data based on routine laboratory testing data are to be used to evaluate the impact of vaccination programmes, it is important to determine how the data are influenced by differences in testing practices, and how these practices are likely to affect the ability of the surveillance data to represent trends in rotavirus disease in the community. We conducted a survey of laboratory testing polices for rotavirus gastroenteritis in England and Wales in 2008. 60% (94/156) of laboratories responded to the survey. 91% of reporting laboratories offered routine testing for rotavirus all year round and 89% of laboratories offered routine rotavirus testing of all stool specimens from children under the age of five years. In 96% of laboratories, rotavirus detection was presently done either by rapid immunochromatographic tests or by enzyme-linked immunosorbent assay. Currently, rotavirus testing policies among laboratories in England and Wales are relatively homogenous. Therefore, surveillance based on laboratory testing data is likely to be representative of rotavirus disease trends in the community in the most frequently affected age groups (children under the age of five years) and could be used to help determine the impact of a rotavirus vaccine.

Adaptive nonlinear least bit error-rate detection for symmetrical RBF beamforming

A powerful symmetrical radial basis function (RBF) aided detector is proposed for nonlinear detection in so-called rank-deficient multiple-antenna assisted beamforming systems. By exploiting the inherent symmetry of the optimal Bayesian detection solution, the proposed RBF detector becomes capable of approaching the optimal Bayesian detection performance using channel-impaired training data. A novel nonlinear least bit error algorithm is derived for adaptive training of the symmetrical RBF detector based on a stochastic approximation to the Parzen window estimation of the detector output's probability density function. The proposed adaptive solution is capable of providing a signal-to-noise ratio gain in excess of 8 dB against the theoretical linear minimum bit error rate benchmark, when supporting four users with the aid of two receive antennas or seven users employing four receive antenna elements.

Linearization and state estimation of unknown discrete-time nonlinear dynamic systems using recurrent neurofuzzy networks

Model-based methods for the state estimation and control of linear systems have been well developed and widely applied. In practice, the underlying systems are often unknown and nonlinear. Therefore, data based model identification and associated linearization techniques are very important. Local linearization and feedback linearization have drawn considerable attention in recent years. In this paper, linearization techniques using neural networks are reviewed, together with theoretical difficulties associated with the application of feedback linearization. A recurrent neurofuzzy network with an analysis of variance (ANOVA) decomposition structure and its learning algorithm are proposed for linearizing unknown discrete-time nonlinear dynamic systems. It can be viewed as a method for approximate feedback linearization, as such it enlarges the class of nonlinear systems that can be feedback linearized using neural networks. Applications of this new method to state estimation are investigated with realistic simulation examples, which shows that the new method has useful practical properties such as model parametric parsimony and learning convergence, and is effective in dealing with complex unknown nonlinear systems.

Piecewise Lyapunov stability conditions of fuzzy systems

In this paper we address the stability of a class of non-linear fuzzy systems that can be decomposed into a set of local models characterized as Takagi-Sugeno models. This new approach includes a consideration of the input membership functions. Via this approach, a reduction in the number of candidate Lyapunov functions and associated linear matrix inequalities (LMIs) is produced. This approach significantly reduces the computational load associated with determining closed loop stability as the input dimension increases.

Kernel Classifier Construction Using Orthogonal Forward Selection and Boosting With Fisher Ratio Class Separability Measure

A greedy technique is proposed to construct parsimonious kernel classifiers using the orthogonal forward selection method and boosting based on Fisher ratio for class separability measure. Unlike most kernel classification methods, which restrict kernel means to the training input data and use a fixed common variance for all the kernel terms, the proposed technique can tune both the mean vector and diagonal covariance matrix of individual kernel by incrementally maximizing Fisher ratio for class separability measure. An efficient weighted optimization method is developed based on boosting to append kernels one by one in an orthogonal forward selection procedure. Experimental results obtained using this construction technique demonstrate that it offers a viable alternative to the existing state-of-the-art kernel modeling methods for constructing sparse Gaussian radial basis function network classifiers that generalize well.

The effect of immunomodulatory treatment on multiple sclerosis fatigue

OBJECTIVE

To assess the effects of glatiramer acetate and beta interferon on fatigue in multiple sclerosis.

METHODS

Fatigue was measured at baseline and six months using the fatigue impact scale (FIS). Groups (glatiramer acetate and beta interferon) were evaluated for the proportion improved, using Fisher's exact test. Logistic regression analysis assessed the relation between treatment group and improvement and controlled for confounding variables.

RESULTS

Six month paired FIS assessments were available for 218 patients (76% female). Ages ranged between 19 and 61 years, with 86% having relapsing-remitting disease. Glatiramer acetate was used by 61% and beta interferon by 39%. At baseline, total FIS and subscale scores were comparable in the two groups. More patients improved on glatiramer acetate than on beta interferon on total FIS (24.8% v 12.9%, p = 0.033; adjusted odds ratio = 2.36, 95% confidence interval 1.03 to 5.42), and on physical (28.6% v 14.1%, p = 0.013) and cognitive subscales (21.1% v 10.6%, p = 0.045). Logistic regression analysis confirmed the association between glatiramer acetate use and improved fatigue, after accounting for baseline group differences.

CONCLUSIONS

The odds of reduced multiple sclerosis fatigue were around twice as great with glatiramer acetate treatment as with beta interferon. Confirmation of this result is required.

On a class of support vector kernels based on frames in function Hilbert spaces

There has been an increasing interest in kernel-based techniques, such as support vector techniques, regularization networks, and gaussian processes. There are inner relationships among those techniques, with the kernel function playing a central role. This article discusses a new class of kernel functions derived from the so-called frames in a function Hilbert space.

Renal effects of cyclooxygenase-2 selective inhibitors

Recent in-vitro and animal data show that cyclooxygenase-2 has an integral role in the physiology and pathophysiology of the kidney. Cyclooxygenase-2 regulates renin-angiotensin secretion, and thereby glomerular filtration rate and sodium homeostasis. It is also important for protecting against hypertonic stress. As a consequence, it is not surprising that clinical data verify that selective inhibitors of cyclooxygenase-2 affect renal function to a degree similar to that which has previously been documented with nonselective nonsteroidal anti-inflammatory drugs.

Bioactive beta-bend structures for the antagonist halpha CGRP(8 - 37) at the CGRP(1) receptor of the rat pulmonary artery

The aim of this study was to determine beta-bend structures and the role of the N- and C-terminus in the antagonist halpha CGRP(8 - 37) at the rat pulmonary artery CGRP receptor mediating halpha CGRP relaxation. Halpha CGRP(8 - 37) Pro(16) (10(-6) M), with a bend-biasing residue (proline) at position 16, did not antagonize halpha CGRP responses, while a structure-conserving amino acid (alanine(16)) at the same position retained antagonist activity (apparent pK(B) 6.6+/-0.1; 10(-6) M). Halpha CGRP(8 - 37) Pro(19) (10(-6) M), with proline at position 19 was an antagonist (apparent pK(B) 6.9+/-0.1). Incorporation of a beta-bend forcing residue, BTD (beta-turn dipeptide), at positions 19 and 20 in halpha CGRP(8 - 37) (10(-6) M) antagonized halpha CGRP responses (apparent pK(B) 7.2+/-0.2); and BTD at positions 19,20 and 33,34 within halpha CGRP(8 - 37) was a competitive antagonist (pA(2) 7.2; Schild plot slope 1.0+/-0.1). Halpha CGRP(8 - 37) analogues, substituted at the N-terminus by either glycine(8) or des-NH(2) valine(8) or proline(8) were all antagonists (apparent pK(B) 6.9+/-0.1; (10(-6) M), 7.0+/-0.1 (10(-6) M), and pA(2) 7.0 (slope 1.0+/-0.2), respectively); while replacements by proline(8) together with glutamic acid(10,14) in halpha CGRP(8 - 37) (10(-6) M) or alanine amide(37) at the C-terminus of halpha CGRP(8 - 37) (10(-5) M) were both inactive compounds. In conclusion, possible bioactive structures of halpha CGRP(8 - 37) include two beta-bends (at 18 - 21 and 32 - 35), which were mimicked by BTD incorporation. Within halpha CGRP(8 - 37), the N-terminus is not essential for antagonism while the C-terminus may interact directly with CGRP(1) receptors in the rat pulmonary artery.

Conformational restraints revealing bioactive beta-bend structures for halpha CGRP8-37 at the CGRP2 receptor of the rat prostatic vas deferens

1. The main aim of this study was to identify putative beta-bends and the role of the N- and C-terminus in the CGRP receptor antagonist halpha CGRP8-37, which was measured against halpha CGRP inhibition of twitch responses in the rat prostatic vas deferens. 2. With a bend-biasing residue (proline) at position 16 in halpha CGRP8-37 (10(-5) M) an inactive compound was produced, while alanine at the same position retained antagonist activity (apparent pKB 5.6+/-0.1 at 10(-5) M). Proline at position 19 within halpha CGRP8-37 (10(-5) M) was an antagonist (apparent pKB 5.8+/-0.1). 3. Incorporation of a bend-forcing structure (beta-turn dipeptide or BTD) at either positions 19,20 or 33,34 in halpha CGRP8-37 (10(-5) M) antagonized halpha CGRP responses (apparent pKB 6.0+/-0.1 and 6.1+/-0.1, respectively). Replacement by BTD at both positions 19,20 and 33,34 within halpha CGRP8-37 competitively antagonized responses to halpha CGRP (pA2 6.2; Schild plot slope 1.0+/-0.1). 4. Halpha CGRP8-37 analogues (10(-5) M), substituted at the N-terminus by either glycine8, or des-NH2 valine8 or proline8 were all antagonists against halpha CGRP (apparent pKB 6.1+/-0.1, 6.5+/-0.1 and 6.1+/-0.1, respectively), while halpha CGRP8-37 (10(-5) M) substituted in three places by proline8 and glutamic acid10,14 was inactive. 5. Replacement of the C-terminus by alanine amide37 in halpha CGRP8-37 (10(-5) M) failed to antagonize halpha CGRP responses. 6. Peptidase inhibitors did not alter either the agonist potency of halpha CGRP or the antagonist affinities of halpha CGRP8-37 BTD19,20 and 33,34 and halpha CGRP8-37 Gly8 (against halpha CGRP responses). 7. In conclusion, two beta-bends at positions 18-21 and 32-35 are compatible with high affinity by BTD and is the first approach of modelling the bioactive structure of halpha CGRP8-37. Further, the N-terminus of halpha CGRP8-37 is not essential for antagonism, while the C-terminus interacts directly with CGRP receptor binding sites of the rat vas deferens.

Design, synthesis and structure of a zinc finger with an artificial beta-turn

We have incorporated a bicyclic beta-turn mimetic (BTD; beta-turn dipeptide) into a zinc finger, creating a zinc finger with an artificial beta-turn. The designed peptide chelates zinc and has the same fold as the unmodified native zinc finger (finger 3 of the human YY1 protein). A combination of 1H NMR and structure calculations reveals that, in solution, this zinc finger has a fold similar to the known wild-type crystal structure and to other zinc fingers containing the consensus sequence X3-Cys-X4-Cys-X12-His-X3-His-X. The peptide was designed with BTD between the chelating cysteine residues, with BTD forming a type II' beta-turn linking the two strands of a distorted anti-parallel beta-sheet. The C-terminal portion of the peptide forms a helix with zinc co-ordinating histidine residues on successive turns of the helix. This work represents a step towards developing methods by which parts of a target protein may be replaced by peptide mimetics.

A multicenter investigation with interphase fluorescence in situ hybridization using X- and Y-chromosome probes

Twenty-six laboratories used X and Y chromosome probes and the same procedures to process and examine 15,600 metaphases and 49,400 interphases from Phaseolus vulgaris-leucoagglutinin (PHA)-stimulated lymphocytes. In Part I, each laboratory scored 50 metaphases and 200 interphases from a normal male and a normal female from its own practice. In Part II, each laboratory scored 50 metaphases and 200 interphases on slides prepared by a central laboratory from a normal male and a normal female and three mixtures of cells from the male and female. In Part III, each laboratory scored 50 metaphases (in samples of 5, 10, 15, and 20) and 100 interphases (in samples of 5, 10, 15, 20, and 50) on new, coded slides of the same specimens used in Part II. Metaphases from male specimens were scored as 98-99% XY with no XX cells, and 97-98% of interphases were scored as XY with 0.04% XX cells. Metaphases from female specimens were scored as 96-97% XX with 0.03% XY cells, and 94-96% of interphases were scored as XX with 0.05% XY cells. Considering the data as a model for any probe used with fluorescence in situ hybridization (FISH), a statistical approach assessing the impact of analytical sensitivity on the numbers of observations required to assay for potential mosaicisms and chimerisms is discussed. The workload associated with processing slides and scoring 50 metaphases and 200 interphases using FISH averaged 27.1 and 28.6 minutes, respectively. This study indicates that multiple laboratories can test/develop guidelines for the rapid, efficacious, and cost-effective integration of FISH into clinical service.

On the convergence rate performance of the normalized least-mean-square adaptation

This paper compares the convergence rate performance of the normalized least-mean-square (NLMS) algorithm to that of the standard least-mean-square (LMS) algorithm, which is based on a well-known interpretation of the NLMS algorithm as a form of the LMS via input normalization. With this interpretation, the analysis is considerably simplified and the difference in rate of parameter convergence can be compared directly by evaluating both the condition number of the normalized and unnormalized input correlation matrix. This paper derives the condition number expressions for the normalized input correlation matrix of which the arbitrary-length filter model is linear with respect to its adaptable parameters and contain only two distinct unnormalized eigenvalues. These expressions, which require that the input samples be statistically stationary and zero-mean Gaussian distributed, provide an important insight into the relative convergence performance of the NLMS algorithm to that of the LMS as a function of filter length. This paper also provides a conjecture which set bounds on the NLMS condition number for any arbitrary number of distinct unnormalized eigenvalues.

The natural history of patients with benign prostatic hyperplasia as diagnosed by North American urologists

PURPOSE

We defined outcomes for men with a clinical diagnosis of benign prostatic hyperplasia.

MATERIALS AND METHODS

We followed for 4 years 500 candidates for elective prostatectomy treated nonoperatively in 5 North American urology practices.

RESULTS

There were 371 survivors with complete data at 4 years. Of 60 men with mild, 245 with moderate and 66 with severe baseline symptoms 10, 24 and 39%, respectively, had undergone surgery; 27, 31 and 27%, respectively, were on pharmacological therapy, and 63, 45 and 33%, respectively, were off active treatment at 4 years. Mild or moderate symptoms were noted at 4 years in 83, 59 and 23% of the patients, respectively, while 17, 41 and 77%, respectively, had severe symptoms or had undergone surgery.

CONCLUSIONS

Outcomes for men with a clinical diagnosis of benign prostatic hyperplasia depend on initial symptom severity. However, the course of symptoms also varies among patients even with the same initial symptom severity.

Multiple solution conformations of the integrin-binding cyclic pentapeptide cyclo(-Ser-D-Leu-Asp-Val-Pro-). Analysis of the (phi, psi) space available to cyclic pentapeptides

The aqueous solution structure of the cyclic pentapeptide cyclo(-Ser-D-Leu-Asp-Val-Pro-) has been determined by two-dimensional 1H-NMR spectroscopy, combined with a conformational search and distance-geometry calculations. As many as five conformers in slow exchange were observed, and the rate of interconversion between components was measured from the build-up rates of exchange peaks. NMR data allowed the structures of the two predominant conformers to be determined. The major component (66%) contained a cis-proline as part of a type-VIa2 beta-turn encompassing residues Asp-Val-cis-Pro-Ser. The second component (16%) contained only trans-amide bonds, and a type-VIII beta-turn formed by residues Val-Pro-Ser-D-Leu. These structures are discussed in relation to the (phi, psi), space available to the cyclic pentapeptide, determined by a conformational search, and in relation to previously published cyclic-pentapeptide structures. The molecule exhibits activity in a scintillation-proximity assay for the inhibition of the interaction between the integrin very-late antigen-4 (VLA-4; alpha 4 beta 1) and vascular-cell-adhesion molecule-1 (VCAM-1). The structure/activity relationship of the LDV sequence is discussed and related to the recently published X-ray structure of VCAM-1. The relevance of the work to the design of anti-inflammatory drugs is discussed.

The occurrence of multiple sclerosis in the Hutterites of North America

OBJECTIVE

To report the occurrence, clinical characteristics and genealogical analysis of multiple sclerosis in the Hutterites of North-Western United States and Western Canada.

BACKGROUND

The incidence of multiple sclerosis is reported to be lower or rare in certain ethnic groups and genetic isolates and was previously observed to be absent in the Hutterite population.

METHODS

After long-term surveillance, six patients were identified and clinical examinations and laboratory investigations including VER and MRI were completed.

RESULTS

The six cases included two brothers, two first cousins, male and female, another male and female, all representing two of the three endogamous groups of Hutterites, are linked to two common ancestors through lines of descent dating to 1723. The individual pedigrees were analyzed from extensive genealogical records covering eight generations.

CONCLUSION

The incidence of multiple sclerosis in Hutterites is low in a high risk area of North America. A specific mode of inheritance pattern has not been established and a common founder effect may play a role in the development of multiple sclerosis. The genetic contribution of the Hutterites seems greater than previously recognized.

Toward quality assurance for metaphase FISH: a multicenter experience

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multicenter determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for small nuclear ribonucleoprotein polypeptide N (SNRPN) and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid, and bone marrow. In an initial study of hybridization efficiency, the median percentage of metaphases from normal individuals showing two SNRPN and two control signals for slides prepared at each site was 97.0 (range = 74-100); for slides prepared by a central laboratory, it was 97.8 (range = 81.6-100). In a subsequent blind study, each laboratory attempted to score 5 metaphases from each of 23 specimens [8 with del(15)(q11.2-->q12) and 15 with normal #15 chromosomes]. Of 529 challenges, the correct SNRPN pattern was found in 5 of 5 metaphases in 457 (86%) and in 4 of 5 in 33 (6%). Ambiguous, incomplete, or no results were reported for 32 (6%) challenges. Seven (1%) diagnostic errors were made, including 6 false positives and 1 false negative: 1 laboratory made 3 errors, 1 made 2, and 2 made 1 each. Most errors and inconsistencies seemed due to inexperience with FISH. The working time to process and analyze slides singly averaged 49.5 min; slides processed in batches of 4 and analyzed singly required 36.9 min. We conclude that proficiency testing for FISH by using an extensive array of challenges is possible and that multiple centers can collaborate to test probes and to evaluate costs.

Toward quality assurance for metaphase FISH: a multi-center experience

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multi-center determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for SNRPN and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid and bone marrow. In an initial study of hybridization efficiency, the median percentage of metaphases from normal individuals showing two SNRPN and 2 control signals for slides prepared at each site was 97.0 (range = 74-100); for slides prepared by a central laboratory, it was 97.8 (range = 81.6-100). In a subsequent blind study, each laboratory attempted to score 5 metaphases from each of 23 specimens [8 with del(15) (q11.2-->q12) and 15 with normal 15 chromosomes]. Of 529 challenges, the correct SNRPN pattern was found in 5 of 5 metaphases in 457 (86%) and in 4 of 5 in 33 (6%). Ambiguous, incomplete or no results were reported for 32 (6%) challenges. Seven (1%) diagnostic errors were made including 6 false positives and 1 false negative: 1 laboratory made 3 errors, 1 made 2, and 2 made 1 each. Most errors and inconsistencies seemed due to inexperience with FISH. The working time to process and analyze slides singly averaged 49.5 minutes; slides processed in batches of 4 and analyzed singly required 36.9 minutes. We conclude that proficiency testing for FISH using an extensive array of challenges is possible and that multiple centers can collaborate to test probes and to evaluate costs.

Towards meeting the Paracelsus Challenge: The design, synthesis, and characterization of paracelsin-43, an alpha-helical protein with over 50% sequence identity to an all-beta protein

In response to the Paracelsus Challenge (Rose and Creamer, Proteins, 19:1-3, 1994), we present here the design, synthesis, and characterization of a helical protein, whose sequence is 50% identical to that of an all-beta protein. The new sequence was derived by applying an inverse protein folding approach, in which the sequence was optimized to "fit" the new helical structure, but constrained to retain 50% of the original amino acid residues. The program utilizes a genetic algorithm to optimize the sequence, together with empirical potentials of mean force to evaluate the sequence-structure compatibility. Although the designed sequence has little ordered (secondary) structure in water, circular dichroism and nuclear magnetic resonance data show clear evidence for significant helical content in water/ethylene glycol and in water/methanol mixtures at low temperatures, as well as melting behavior indicative of cooperative folding. We believe that this represents a significant step toward meeting the Paracelsus Challenge.

Synthesis of Hexahydrocyclopentimidazol-2-(1H)-one derivatives displaying selective DP-receptor agonist properties

The rationale for investigating conformationally restricted analogues of BW245C as DP-receptor ligands and the syntheses of three such racemic bicyclic imidazolidinone analogues are described. Compounds 7 (BW587C), 8 (BW480C85), and 9 (BW572C85) were found to be potent inhibitors of human platelet aggregation and selective DP-receptor agonists in washed platelet and jugular vein isolated tissue assays.

Long-term intrathecal baclofen therapy in patients with intractable spasticity

BACKGROUND

Severe spasticity unresponsive to oral drugs may respond satisfactorily to baclofen delivered intrathecally.

METHODS

Intrathecal baclofen (IB) therapy delivered by means of implanted infusion pumps was used for nine patients with severe spasticity. Six patients had multiple sclerosis, two cervical spinal cord injury, and one head injury. All were non-ambulatory.

RESULTS

Patients showed improvement in many areas, including ability to transfer, seating, pain control, personal care, and liability to skin breakdown. Before IB therapy, only three of the nine patients were able to live at home in the community and six were institutionalized. At the end of our follow-up period, only one patient remained institutionalized, three lived in group homes and five lived at home in the community. In the year preceding pump implantation, the nine patients spent a total of 755 days in acute care hospitals. In the year following onset of IB therapy, they spent only 259 days in hospital.

CONCLUSIONS

IB therapy can improve patient quality of life and can be cost-effective in carefully selected patients with severe spasticity and disability. The drug delivery catheter is that part of the therapeutic system most vulnerable to failure. Because of the varied expertise required to manage these patients effectively, and the potential for a variety of complications, it is essential that an IB program is supported by a well-organized multi-disciplinary medical team.

A perspective and critique of adaptive neurofuzzy systems used for modelling and control applications

This paper outlines some of the theoretical and practical developments being made in neurofuzzy systems. As the name suggests, neurofuzzy networks were developed by fusing the ideas that originated in the fields of neural and fuzzy systems. A neurofuzzy network attempts to combine the transparent, linguistic, symbolic representation associated with fuzzy logic with the architecture and learning rules commonly used in neural networks. These hybrid structures have both a qualitative and a quantitative interpretation and can overcome some of the difficulties associated with solely neural algorithms which can usually be regarded as black box mappings, and with fuzzy systems where few modelling and learning theories existed. Both B-spline and Gaussian Radial Basis Function networks can be regarded as neurofuzzy systems and soft inductive learning algorithms can be used to extract unknown, qualitative information about the relationships contained in the training data. In a similar manner, qualitative rules or information about the network's structure can be used to initialise the system. These areas, coupled with the extensive work being carried out on theoretically analysing their modelling, convergence and stability properties means that this research topic is highly applicable in "intelligent" modelling and control problems. Apart from outlining this work, the paper also discusses a wide variety of open research questions and suggests areas where new efforts may be fruitfully applied.

Long term treatment of intractable reflex sympathetic dystrophy with intrathecal morphine

BACKGROUND

Some patients with reflex sympathetic dystrophy (RD) develop intractable symptoms unresponsive to conventional therapy. Recently, intrathecal morphine therapy has been used with some success in such patients.

METHODS

The clinical course of two patients with intractable reflex sympathetic dystrophy (RSD) is described. Both patients developed intractable leg pain, swelling and autonomic changes after a leg injury. Numerous medical treatments and surgical sympathectomies failed to provide long term relief.

RESULTS

Relatively satisfactory symptom control was achieved only with the use of long term intrathecal morphine therapy delivered by subcutaneously implanted infusion pumps. Exacerbations of the RSD continued to occur, at times in association with further leg trauma, but these could be controlled by a temporary escalation of the intrathecal morphine dose. Complications of morphine therapy were relatively minor. A red rash appearing over the pump site was the first sign that a drug catheter break had occurred, necessitating surgical catheter revision.

CONCLUSION

Long term intrathecal morphine therapy is a useful treatment option for patients with intractable severe RSD who have failed other therapies and remain markedly disabled.

Comments on "Learning convergence in the cerebellar model articulation controller"

The commenter refers to the paper by Wong-Sideris (ibid. vol.3, p.115-21 (1992)) claiming that the original Albus CMAC (or binary CMAC) is capable of learning an arbitrary multivariate lookup table, the linear optimization process is strictly positive definite, and that the basis functions are linearly independent, given sufficient training data. In recent work by Brown et al. (1994), however, it has been proved that the multivariate binary CMAC is unable to learn certain multivariate lookup tables and the number of such orthogonal functions increases exponentially as the generalization parameter is increased. A simple 2D orthogonal function is presented as a counterexample to the original theory. It is also demonstrated that the basis functions are-always linearly dependent, both for the univariate and the multivariate case, and hence the linear optimization process is only positive semi-definite and there always exists an infinite number of possible optimal weight vectors.

A global gradient-noise covariance expression for stationary real Gaussian inputs

Supervised parameter adaptation in many artificial neural networks is largely based on an instantaneous version of gradient descent called the least-mean-square (LMS) algorithm. This paper considers only neural models which are linear with respect to their adaptable parameters and has two major contributions. First, it derives an expression for the gradient-noise covariance under the assumption that the input samples are real, stationary, Gaussian distributed but can be partially correlated. This expression relates the gradient correlation and input correlation matrices to the gradient-noise covariance and explains why the gradient noise generally correlates maximally with the steepest principal axis and minimally with the one of the smallest curvature, regardless of the magnitude of the weight error. Second, a recursive expression for the weight-error correlation matrix is derived in a straightforward manner using the gradient-noise covariance, and comparisons are drawn with the complex LMS algorithm.