PHQ-9 was translated to Kinyarwanda using translation-back translation and validated by a discussion group. For validation, PwE of greater than or equal to15 years of age were administered the PHQ-9 ...and Hamilton Depression Rating Scale (HDRS) by trained psychiatry staff at Visit 1. A random sample of 20% repeated PHQ-9 and HDRS after 14 days to assess temporal stability and intra-rater reliability. Internal structure, reliability and external validity were assessed using confirmatory factor analysis, reliability coefficients and HDRS-correlation, respectively. Maximal Youden's index was considered for cut-offs. Four hundred and thirty-four PwE, mean age 30.5 years (SD ±13.3), were included of whom 33.6%, 37.9%, 13.4%, and 15.1% had no, mild, moderate and severe depression, respectively. PHQ-9 performed well on a one-factor model (unidimensional model), with factor loadings of 0.63-0.86. Reliability coefficients above 0.80 indicated strong internal consistency. Good temporal stability was observed (0.79 95% CI: 0.68-0.87). A strong correlation (R = 0.66, p = 0.01) between PHQ-9 and HDRS summed scores demonstrated robust external validity. The optimal cut-off for the PHQ-9 was similar (greater than or equal to5) for mild and moderate depression and greater than or equal to7 for severe depression. PHQ-9 validation in Kinyarwanda creates the capacity to screen PwE in Rwanda at scores of greater than or equal to5 for mild or moderate and greater than or equal to7 for severe depression. The availability of validated tools for screening and diagnosis for depression is a forward step for holistic care in a resource-limited environment.
Microbial interaction is an integral component of microbial ecology studies, yet the role, extent, and relevance of microbial interaction in community functioning remains unclear, particularly in the ...context of global biogeochemical cycles. While many studies have shed light on the physico-chemical cues affecting specific processes, (micro)biotic controls and interactions potentially steering microbial communities leading to altered functioning are less known. Yet, recent accumulating evidence suggests that the concerted actions of a community can be significantly different from the combined effects of individual microorganisms, giving rise to emergent properties. Here, we exemplify the importance of microbial interaction for ecosystem processes by analysis of a reasonably well-understood microbial guild, namely, aerobic methane-oxidizing bacteria (MOB). We reviewed the literature which provided compelling evidence for the relevance of microbial interaction in modulating methane oxidation. Support for microbial associations within methane-fed communities is sought by a re-analysis of literature data derived from stable isotope probing studies of various complex environmental settings. Putative positive interactions between active MOB and other microbes were assessed by a correlation network-based analysis with datasets covering diverse environments where closely interacting members of a consortium can potentially alter the methane oxidation activity. Although, methanotrophy is used as a model system, the fundamentals of our postulations may be applicable to other microbial guilds mediating other biogeochemical processes.
Indoleamine 2,3-dioxygenases (IDOs) degrade l-tryptophan to kynurenines and drive the de novo synthesis of nicotinamide adenine dinucleotide. Unsurprisingly, various invertebrates, vertebrates, and ...even fungi produce IDO. In mammals, IDO1 also serves as a homeostatic regulator, modulating immune response to infection via local tryptophan deprivation, active catabolite production, and non-enzymatic cell signaling. Whether fungal Idos have pleiotropic functions that impact on host-fungal physiology is unclear. Here, we show that Aspergillus fumigatus possesses three ido genes that are expressed under conditions of hypoxia or tryptophan abundance. Loss of these genes results in increased fungal pathogenicity and inflammation in a mouse model of aspergillosis, driven by an alternative tryptophan degradation pathway to indole derivatives and the host aryl hydrocarbon receptor. Fungal tryptophan metabolic pathways thus cooperate with the host xenobiotic response to shape host-microbe interactions in local tissue microenvironments.
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•Aspergillus Idos contribute to de novo NAD+ biosynthesis and fungal growth•In conditions of tryptophan abundance, Aspergillus releases indole derivatives via Aro•Activation of lung AhR enhances harmful lung inflammation during fungal infection•Pharmacological induction of Ido in Aspergillus improves infection outcome
Mammalians use the kynurenine pathway for tryptophan degradation inducing tolerogenic immune responses. Zelante et al. report that similarly, the fungus Aspergillus fumigatus uses the kynurenine pathway. Pathogenic immune response occurs when the fungus catabolizes tryptophan via the indolepyruvate pathway, which targets host AhR. Administration of Ido inducers ameliorates infection outcome.
Summary
Methane‐oxidizing bacteria (MOB) possess the ability to use methane for energy generation and growth, thereby, providing a key ecosystem service that is highly relevant to the regulation of ...the global climate. MOB subgroups have different responses to key environmental controls, reflecting on their functional traits. Their unique features (C1‐metabolism, unique lipids and congruence between the 16S rRNA and pmoA gene phylogeny) have facilitated numerous environmental studies, which in combination with the availability of cultured representatives, yield the most comprehensive ecological picture of any known microbial functional guild. Here, we focus on the broad MOB subgroups (type I and type II MOB), and aim to conceptualize MOB functional traits and observational characteristics derived primarily from these environmental studies to be interpreted as microbial life strategies. We focus on the functional traits, and the conditions under which these traits will render different MOB subgroups a selective advantage. We hypothesize that type I and type II MOB generally have distinct life strategies, enabling them to predominate under different conditions and maintain functionality. The ecological characteristics implicated in their adopted life strategies are discussed, and incorporated into the Competitor‐Stress tolerator‐Ruderal functional classification framework as put forward for plant communities. In this context, type I MOB can broadly be classified as competitor‐ruderal while type II MOB fit more within the stress tolerator categories. Finally, we provide an outlook on MOB applications by exemplifying two approaches where their inferred life strategies could be exploited thereby, putting MOB into the context of microbial resource management.
Melaleuca ericifolia Sm. (Swamp paperbark) is a common tree species in freshwater and brackish wetlands in southern and eastern Australia. The survival of this species in many wetlands is now ...threatened by increased salinity and inappropriate water regimes. We examined the response of 5-month-old
M. ericifolia seedlings to three water depths (exposed, waterlogged and submerged) at three salinities (2, 49 and 60
dS
m
−1). Increasing water depth at the lowest salinity did not affect survival, but strongly inhibited seedling growth. Total biomass, leaf area and maximum root length were highest in exposed plants, intermediate in waterlogged plants and lowest in submerged plants. Although completely submerged plants survived for 10 weeks at the lowest salinity, they demonstrated negative growth rates and were unable to extend their shoots above the water surface. At the higher salinities,
M. ericifolia seedlings were intolerant of waterlogging and submergence: all plants died after 9 weeks at 60
dS
m
−1. Soil salinities increased over time, and by Week 10, exceeded external water column salinities in both the exposed and waterlogged treatments. In exposed sediment, ∼90% of plants survived for 10 weeks at 60
dS
m
−1 even though soil salinities reached ∼76
dS
m
−1. No mortality occurred in the exposed plants at 49
dS
m
−1, and small but positive relative growth rates were recorded at Week 10. We conclude that at low salinities
M. ericifolia seedlings are highly tolerant of sediment waterlogging, but are unlikely to tolerate prolonged submergence. However, at the higher salinities,
M. ericifolia seedlings are intolerant of waterlogging and submergence and died rapidly after 5 weeks exposure to this combination of environmental stressors. This research demonstrates that salinity may restrict the range of water regimes tolerated by aquatic plants.
Numerous studies have demonstrated that administration of rimonabant (SR 141716), a CB1 receptor antagonist, causes a decrease in energy intake. However, the mechanisms by which rimonabant exerts its ...anorectic actions are unclear. The main focus of the study reported here was to establish the chemical identity of neurons that may subserve the anorectic effects of rimonabant. As such three approaches were utilised: (i) the identification of rimonabant‐activated neurons using Fos as a marker of neuronal activity; (ii) the identification of the chemical phenotype of rimonabant‐activated neurons by combining immunocytochemical identification of Fos and feeding‐related peptides; and (iii) the evaluation of the effect of rimonabant on messenger RNA (mRNA) and protein for a number of feeding‐related peptides. Rimonabant‐induced Fos‐positive nuclei were localized within a range of discrete hypothalamic regions with a predominance in the parvocellular part of the paraventricular nucleus of the hypothalamus, dorsomedial hypothalamus, arcuate nucleus and lateral hypothalamic area. Furthermore, Fos labelling within these hypothalamic regions was colocalized with anorexigenic and orexigenic peptides including melanin‐concentrating hormone (MCH), orexin, cocaine‐ and amphetamine‐regulated transcript (CART) and alpha‐melanocyte‐stimulating hormone (α‐MSH). Rimonabant specifically induced a decrease in NPY and an increase in CART and α‐MSH mRNA and protein, consistent with its effect in reducing food intake and increasing energy expenditure. As such these data provide insights into the mechanisms of action that may underpin rimonabant’s effects on energy balance and body weight.
Ongoing HIV dissemination during HAART Grossman, Zvi; Polis, Michael; Feinberg, Mark B ...
Nature medicine,
199910, 1999-Oct, 1999-10-00, 19991001, Letnik:
5, Številka:
10
Journal Article
Recenzirano
A model of HIV replication is presented to explain why antiretroviral drugs do not completely eradicate the virus from the body. HIV replication may occur in bursts in various tissues and drugs can ...reduce the size of the burst but not completely abolish it.
The utility of shallow water bodies in urban environments is frequently compromised either by dense beds of submerged plants or cyanobacterial blooms associated with nutrient enrichment. Although ...submerged plants are often harvested to facilitate recreational uses, this activity may alter the phytoplankton community, which in turn, also may restrict the use of the lake. We tested whether (i) plant harvesting reduced the abundance of flagellate algae and increased the abundance of cyanobacteria, and (ii) whether increasing levels of nutrient enrichment caused shifts in the dominance of heterocytous cyanobacteria, non-heterocytous cyanobacteria and Chlorophyta, in a shallow urban lake in Southern Australia as has been observed for shallow Danish lakes in previous studies. These predictions were tested with large (3000 l), replicated mesocosms in a warm, highly productive, shallow lake densely colonised by the submerged angiosperm, Vallisnaria americana Michaux. The heterokont algae, Chlorophyta, Cyanobacteria and Cryptophyta were the most numerous algal divisions in the lake. The Euglenophyta, although uncommon in early summer, became more abundant towards the end of summer. The Dinophyta and Charophyta were rare. The abundance of the heterokont algae and Euglenophyta was significantly reduced by plant harvesting even after plants had partially re-established 18 weeks after initial harvesting. The decline in the Euglenophyta in response to plant harvesting is consistent with earlier findings, that the relative abundance of flagellate algae tends to be greater in the presence of submerged plants. Contrary to our prediction, we found that the Cyanobacteria did not increase in response to plant harvesting, however the response may be altered under higher nutrient levels. Algal responses to nutrient enrichment in the presence of dense V. americana plants generally followed the patterns observed in shallow Danish lakes despite the large differences in climatic conditions. Both studies found that the abundance of heterocytous cyanobacteria declined at higher levels of nutrient enrichment, whereas non-heterocytous cyanobacteria and chlorophytes increased.PUBLICATION ABSTRACT
Abstract
Numerous studies have demonstrated that administration of rimonabant (SR 141716), a CB
1
receptor antagonist, causes a decrease in energy intake. However, the mechanisms by which rimonabant ...exerts its anorectic actions are unclear. The main focus of the study reported here was to establish the chemical identity of neurons that may subserve the anorectic effects of rimonabant. As such three approaches were utilised: (i) the identification of rimonabant‐activated neurons using Fos as a marker of neuronal activity; (ii) the identification of the chemical phenotype of rimonabant‐activated neurons by combining immunocytochemical identification of Fos and feeding‐related peptides; and (iii) the evaluation of the effect of rimonabant on messenger RNA (mRNA) and protein for a number of feeding‐related peptides. Rimonabant‐induced Fos‐positive nuclei were localized within a range of discrete hypothalamic regions with a predominance in the parvocellular part of the paraventricular nucleus of the hypothalamus, dorsomedial hypothalamus, arcuate nucleus and lateral hypothalamic area. Furthermore, Fos labelling within these hypothalamic regions was colocalized with anorexigenic and orexigenic peptides including melanin‐concentrating hormone (MCH), orexin, cocaine‐ and amphetamine‐regulated transcript (CART) and alpha‐melanocyte‐stimulating hormone (α‐MSH). Rimonabant specifically induced a decrease in NPY and an increase in CART and α‐MSH mRNA and protein, consistent with its effect in reducing food intake and increasing energy expenditure. As such these data provide insights into the mechanisms of action that may underpin rimonabant’s effects on energy balance and body weight.
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