Longitudinal neuropsychological trajectories in idiopathic normal pressure hydrocephalus: a population-based study

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a progressive syndrome affecting gait, incontinence, and cognition in a significant number of older adults. Still, prospective studies on early development of symptoms are scarce.

AIM

To investigate how neuropsychological functions develop before and in already diagnosed iNPH over a two-year period in a population-based material.

METHOD

A sample of 104 participants (median [IQR] 75 [72-80] years old) from the general population underwent CT-imaging and clinical assessment at baseline and follow-up. We used the iNPH symptom scale covering four domains (Neuropsychology, Gait, Balance, Incontinence) and additional tests of executive functions. Morphological signs were rated with the iNPH Radscale. Non-parametric statistics with Bonferroni corrections and a significance-level of p < 0.05 were used.

RESULTS

Median (IQR) time to follow-up was 25 (23-26) months. Effect size (ES) for individuals who developed iNPH (n = 8) showed a large (ES r = -0.55) decline in the Gait domain and on the Radscale (ES r = -0.60), with a medium deterioration in declarative memory (ES r = -0.37). Those having iNPH at baseline (n = 12) performed worse on one executive sub-function i.e., shifting (p = 0.045).

CONCLUSION

Besides deterioration in gait and radiology, our results suggest that a neuropsychological trajectory for those developing iNPH includes a reduction in declarative memory. Executive dysfunction was limited to those already having iNPH at baseline. These findings could suggest that memory impairments are included in the early development of iNPH.

Lactic acid bacteria that activate immune gene expression in Caenorhabditis elegans can antagonise Campylobacter jejuni infection in nematodes, chickens and mice

BACKGROUND

Campylobacter jejuni is the major micro-bacillary pathogen responsible for human coloenteritis. Lactic acid bacteria (LAB) have been shown to protect against Campylobacter infection. However, LAB with a good ability to inhibit the growth of C. jejuni in vitro are less effective in animals and animal models, and have the disadvantages of high cost, a long cycle, cumbersome operation and insignificant immune response indicators. Caenorhabditis elegans is increasingly used to screen probiotics for their anti-pathogenic properties. However, no research on the use of C. elegans to screen for probiotic candidates antagonistic to C. jejuni has been conducted to date.

RESULTS

This study established a lifespan model of C. elegans, enabling the preselection of LAB to counter C. jejuni infection. A potential protective mechanism of LAB was identified. Some distinct LAB species offered a high level of protection to C. elegans against C. jejuni. The LAB strains with a high protection rate reduced the load of C. jejuni in C. elegans. The transcription of antibacterial peptide genes, MAPK and Daf-16 signalling pathway-related genes was elevated using the LAB isolates with a high protection rate. The reliability of the lifespan model of C. elegans was verified using mice and chickens infected with C. jejuni.

CONCLUSIONS

The results showed that different LAB had different abilities to protect C. elegans against C. jejuni. C. elegans provides a reliable model for researchers to screen for LAB that are antagonistic to C. jejuni on a large scale.

Cognitive impairment from early to middle adulthood in patients with affective and nonaffective psychotic disorders

BACKGROUND

Cognitive impairment is a core feature of psychotic disorders, but the profile of impairment across adulthood, particularly in African-American populations, remains unclear.

METHODS

Using cross-sectional data from a case-control study of African-American adults with affective (n = 59) and nonaffective (n = 68) psychotic disorders, we examined cognitive functioning between early and middle adulthood (ages 20-60) on measures of general cognitive ability, language, abstract reasoning, processing speed, executive function, verbal memory, and working memory.

RESULTS

Both affective and nonaffective psychosis patients showed substantial and widespread cognitive impairments. However, comparison of cognitive functioning between controls and psychosis groups throughout early (ages 20-40) and middle (ages 40-60) adulthood also revealed age-associated group differences. During early adulthood, the nonaffective psychosis group showed increasing impairments with age on measures of general cognitive ability and executive function, while the affective psychosis group showed increasing impairment on a measure of language ability. Impairments on other cognitive measures remained mostly stable, although decreasing impairments on measures of processing speed, memory and working memory were also observed.

CONCLUSIONS

These findings suggest similarities, but also differences in the profile of cognitive dysfunction in adults with affective and nonaffective psychotic disorders. Both affective and nonaffective patients showed substantial and relatively stable impairments across adulthood. The nonaffective group also showed increasing impairments with age in general and executive functions, and the affective group showed an increasing impairment in verbal functions, possibly suggesting different underlying etiopathogenic mechanisms.

Fifty-year follow-up of childhood epilepsy - Social, psychometric, and occupational outcome

OBJECTIVE

The objective of this study was to explore and describe the experience of a childhood diagnosis of epilepsy and its consequences for the experiences of daily life over a span of 50 years.

METHODS

A descriptive mixed method design was chosen. Data were collected through a survey returned by 86 persons (59% response rate) who had received diagnoses of epilepsy as children. The survey contained questions about education, vocation, family status, and included the 14-item Hospital Anxiety and Depression Scale (HAD). Additionally, interviews (n = 11) were conducted and analyzed by interpretative description.

RESULTS

Few persons reported that the childhood diagnosis of epilepsy had affected their choice of education, work, or leisure activities. However, 20% reported that the diagnosis had caused problems in school or at work and had restricted their activities of daily living. Sixty-six percent of the participants were married, and 68% had children; of those, 12 (20%) reported that one or more of the children had also had seizures. Almost all reported no anxiety (82%) and no depression (90%). The results of the interviews revealed a balancing act between 'Controlling and managing the situation' and 'Not being restricted by the condition'.

SIGNIFICANCE

This long-term follow-up over a 50-year life-span of persons who received childhood diagnoses of epilepsy suggests that the consequences for education, work, and leisure activities were few. Most of the participants had developed strategies to manage their situation.

Network structural dependency in the human connectome across the life-span

Principles of network topology have been widely studied in the human connectome. Of particular interest is the modularity of the human brain, where the connectome is divided into subnetworks from which changes with development, aging or disease can be investigated. We present a weighted network measure, the Network Dependency Index (NDI), to identify an individual region’s importance to the global functioning of the network. Importantly, we utilize NDI to differentiate four subnetworks (Tiers) in the human connectome following Gaussian mixture model fitting. We analyze the topological aspects of each subnetwork with respect to age and compare it to rich club-based subnetworks (rich club, feeder, and seeder). Our results first demonstrate the efficacy of NDI to identify more consistent, central nodes of the connectome across age groups, when compared with the rich club framework. Stratifying the connectome by NDI led to consistent subnetworks across the life-span, revealing distinct patterns associated with age where, for example, the key relay nuclei and cortical regions are contained in a subnetwork with highest NDI. The divisions of the human connectome derived from our data-driven NDI framework have the potential to reveal topological alterations described by network measures through the life-span.

Excess medical comorbidity and mortality across the lifespan in schizophrenia.: A nationwide Danish register study

INTRODUCTION

People with severe mental illness have greater risk of un-detected and inadequately treated medical disorders, adding up to the risk of premature death. This study investigated how chronic medical comorbidity evolved across the lifespan in schizophrenia and the associated impact on mortality.

METHOD

A register-based retrospective nested case-control study was conducted, identifying incident cases of cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD), cancer and diabetes, as well as mortality due to these diseases, across the lifespan in schizophrenia.

SAMPLE

A schizophrenia cohort consisting of 4924 individuals aged 18-40 years registered with a diagnosis of schizophrenia (ICD-8: 295.0-3 + 295.9) during admission to a psychiatric hospital unit in 1970-79. Schizophrenia cases were age and gender matched with 22,597 controls in the general population.

RESULTS

Rate ratio (RR) of CVD and cancer were similar to controls. The RR of COPD and diabetes were increased across the lifespan. The probability of having been diagnosed prior to dying from CVD, cancer, pulmonary diseases or diabetes was markedly reduced in schizophrenia cases compared to controls. The RR of all-cause mortality and mortality from CVD, COPD and diabetes remained elevated in all age groups in schizophrenia. Registration of medical comorbidity was associated with increased survival.

CONCLUSION

Excess medical comorbidity persists across the lifespan and into older age. No age-related decrease in incidence of major chronic medical comorbidities in schizophrenia was found except for diabetes.

Delayed mortality and sublethal effects of cold stress in Drosophila melanogaster

Analysis of sublethal responses in cold-stressed insects can provide important information about fitness costs and a better understanding of the physiological mechanisms used to prevent and/or to cope with cold injury. Yet, such responses are understudied and often neglected in the literature. Here, we analyzed the effects of cold stress applied to larvae on the mortality/survival and fitness parameters of survivor adults of the vinegar fly, Drosophila melanogaster. Third instar larvae (either cold-sensitive or cold-acclimated) were exposed to either supercooling or freezing stress, both at -5 °C. A whole array of sublethal effects were observed, from mortality that occurs with some delay after cold stress, through delayed development to the pupal stage, to shortened life-span of the adult, and decreased female fecundity. Taking the sublethal effects into account improves the ecological meaningfulness of cold hardiness assay outcomes. For instance, we observed that although more than 80% of cold-acclimated larvae survive freezing to -5 °C, less than 10% survive until adulthood, and survivor females exhibit more than 50% reduction in their fecundity relative to controls. Female fecundity was positively correlated with dry mass and negatively correlated with total protein and glycogen stores. Hence, these parameters may serve as good predictors of survivor adult female fecundity. Further, we provide the concept of a two-component defense system, which (based on analysis of sublethal effects on fitness parameters) distinguishes between physiological mechanisms that help insects to resist (reduce or avoid) or tolerate (survive or repair) injuries linked to cold stress.

Suppressing Tau Aggregation and Toxicity by an Anti-Aggregant Tau Fragment

Tau aggregation is a hallmark of a group of neurodegenerative diseases termed Tauopathies. Reduction of aggregation-prone Tau has emerged as a promising therapeutic approach. Here, we show that an anti-aggregant Tau fragment (F3^ΔKPP, residues 258–360) harboring the ΔK280 mutation and two proline substitutions (I²⁷⁷P & I³⁰⁸P) in the repeat domain can inhibit aggregation of Tau constructs in vitro, in cultured cells and in vivo in a Caenorhabditis elegans model of Tau aggregation. The Tau fragment reduced Tau-dependent cytotoxicity in a N2a cell model, suppressed the Tau-mediated neuronal dysfunction and ameliorated the defective locomotion in C. elegans. In vitro the fragment competes with full-length Tau for polyanionic aggregation inducers and thus inhibits Tau aggregation. Our combined in vitro and in vivo results suggest that the anti-aggregant Tau fragment may potentially be used to address the consequences of Tau aggregation in Tauopathies.

How cushion communities are maintained in alpine ecosystems: A review and case study on alpine cushion plant reproduction

Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides (Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.

Tyrosine hydroxylase haploinsufficiency prevents age-associated arterial pressure elevation and increases half-life in mice

Catecholamines are essential for the maintenance of physiological homeostasis under basal and stress conditions. We aim to determine the impact of deletion of a single allele of the tyrosine hydroxylase (Th) gene might have on aging arterial pressure and life-span. We found that Th haploinsufficiency prevents age-associated increase of arterial pressure (AP) in mature adult mice, and it results in the extension of the half-life of Th-heterozygous (TH-HET) mice respect to their wild-type (WT) littermates. Heart performance was similar in both genotypes. To further investigate the lack of increase in AP with age in TH-HET mice, we measured the AP response to intra-peritoneal administration of substances involved in AP regulation. The response to acetylcholine and the basal sympathetic tone were similar in both genotypes, while norepinephrine had a greater pressor effect in TH-HET mice, which correlated with altered adrenoreceptor expression in blood vessels and the heart. Furthermore, sympatho-adrenomedular response to stress was attenuated in TH-HET mice. Plasma catecholamine levels and urine glucose increased markedly in WT but not in TH-HET mice after stress. Our results showed that TH-HET mice are resistant to age-associated hypertension, present a reduction in the sympathetic response to stress and display an extended half-life.

The Geropathology Research Network: An Interdisciplinary Approach for Integrating Pathology Into Research on Aging

Geropathology is the study of aging and age-related lesions and diseases in the form of whole necropsies/autopsies, surgical biopsies, histology, and molecular biomarkers. It encompasses multiple subspecialties of geriatrics, anatomic pathology, molecular pathology, clinical pathology, and gerontology. In order to increase the consistency and scope of communication in the histologic and molecular pathology assessment of tissues from preclinical and clinical aging studies, a Geropathology Research Network has been established consisting of pathologists and scientists with expertise in the comparative pathology of aging, the design of aging research studies, biostatistical methods for analysis of aging data, and bioinformatics for compiling and annotating large sets of data generated from aging studies. The network provides an environment to promote learning and exchange of scientific information and ideas for the aging research community through a series of symposia, the development of uniform ways of integrating pathology into aging studies, and the statistical analysis of pathology data. The efforts of the network are ultimately expected to lead to a refined set of sentinel biomarkers of molecular and anatomic pathology that could be incorporated into preclinical and clinical aging intervention studies to increase the relevance and productivity of these types of investigations.

The double mutation of cytochrome P450's and fatty acid desaturases affect lipid regulation and longevity in C. elegans

An imbalance between energy uptake and energy expenditure can lead to obesity and increase the risk of coronary heart disease, high blood pressure, stroke, type II diabetes and some cancers. Given that key elements of the energy pathway are evolutionary conserved, invertebrate research is an attractive alternative that overcomes the many legislative, financial and experimental hurdles typical of research with higher metazoan animals. Recent studies have suggested that some members of the cytochrome P450 superfamily are involved in lipid metabolism in addition to the traditional xenobiotic activity. To investigate this notion in more detail, the present study aimed to pinpoint phenotypic, genetic and genomic-level responses of Caenorhabditis elegans using selected deletion mutants including fat-5 (a member of the Δ9 desaturases) and cyp-35A2 (a member of the cytochrome P450 family). The creation of a fat-5(tm420);cyp-35A2(gk317) mutant uncovered that the deletion of both genes resulted in a strain which is marked by an extended lifespan. Furthermore, it diminished the overall level of Nile Red positive compartments, which is indicative of a change in lipid metabolism. Comprehensive transcriptomics revealed that several genes involved in aging and lipid transport/homeostasis were modulated following the double deletion of fat-5 and cyp-35A2. Taken together, the results suggest the presence of a putative correlation between longevity and lipid regulation and given that both genes have human homologs, this finding may offer a new lead to investigate in higher organisms.

Regulatory Roles of miRNAs in Aging

Aging is a biological process characterized by the progressive deterioration of physiological functions that occurs through the accumulation of macromolecular and cellular damage. This phenomenon impairs tissue function and is a risk factor for many disorders including cardiovascular disease, neurodegenerative disorders, and cancer. A recent study has enumerated nine cellular and molecular hallmarks that represent common denominators of aging and together determine the aging phenotype, highlighting the concept of aging plasticity. Among the multiple molecular mechanisms which may contribute to aging modulation, microRNAs (miRNAs) are raising enormous interest due to their ability to affect all the "Hallmarks of Aging." In this chapter, we will focus on the description of the diverse functional roles of geromiRs, the large and growing subgroup of miRNAs implicated in aging. We will also address the molecular mechanisms underlying miRNA function in aging and discuss potential strategies for managing aging and extending longevity based on geromiR modulation.

Cloning of cDNA encoding a Bombyx mori homolog of human oxidation resistance 1 (OXR1) protein from diapause eggs, and analyses of its expression and function

To better understand the molecular mechanisms of diapause initiation, we used the sensitive cDNA subtraction (selective amplification via biotin- and restriction-mediated enrichment) method and isolated a novel gene expressed abundantly in diapause eggs of the silkworm, Bombyx mori, which encodes a homolog of the human oxidation resistance 1 (OXR1) protein. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting analyses confirmed that BmOXR1 mRNA and its 140-kDa protein were differentially expressed in diapause eggs compared to non-diapause eggs. OXR1 double-stranded RNA (dsRNA) was injected into diapause-destined eggs before the cellular blastoderm stage, and 4days later, when untreated eggs reached the diapause stage, the OXR1 protein disappeared; however, these eggs remained in diapause, suggesting that BmOXR1 is not essential for diapause initiation and/or maintenance. To further investigate the in vivo function of BmOXR1 apart from its role in diapause, we overexpressed BmOXR1 in Drosophila melanogaster. The fruit fly male adult life-span was significantly extended in the 50%-survival time when adults were reared on diets both with and without H2O2 solution under 25°C incubation. These results suggest that BmOXR1 functions in D. melanogaster via a possible antioxidant effect. As BmOXR1 was expressed mainly in the nuclei of D. melanogaster cells, the mechanism underlying its antioxidation effect appears to be different from that in humans where it is expressed mainly in the mitochondria. Taken together, these results suggest that BmOXR1 might serve as an antioxidant regulator during the early diapause stage.