Self-Reported Hindering Health Complaints of Community-Dwelling Older Persons: A Cross-Sectional Study

Purpose

Proactive care for community-dwelling older persons targeting self-reported hindering health complaints might prevent a decline in function. We investigated the spectrum of self-reported hindering complaints of community-dwelling older persons, the association with functional outcomes, and help-seeking behavior for these complaints.

Methods

Within the ISCOPE trial, participants (aged ≥75 years) received the ISCOPE screening questionnaire, including the open-ended question “At the moment, which health complaints limit you the most in your day-to-day life?”. After coding the answers with the ICPC-1-NL, we examined the prevalence and the association between the number and type of complaints and functional outcomes (Groningen Activities Restriction Scale, quality of life measured on Cantril’s Ladder, Mini-Mental State Examination, Geriatric Depression Scale-15, and De Jong Gierveld Loneliness Scale). Electronic patient registers were searched for the most reported complaints.

Results

7285 participants (median age: 81.0 years [IQR 77.8–85.3], 38.6% males) reported 13,524 hindering complaints (median 1, range 0–18); 32.7% reported no complaints. Participants mostly reported problems with walking/standing (22.1%), pain (20.8%) or weakness/tiredness (8.5%). These complaints were mentioned in the electronic patient registers in 28.3%, 91.3% and 55.5%, respectively. Higher numbers of hindering complaints were related to poorer scores on the number of domains with problems, Cantril’s Ladder for quality of life, Groningen Activities Restriction Scale, Geriatric Depression Scale, and De Jong Gierveld Loneliness Scale. Self-reported weakness, problems with walking/standing, visual limitations, cognitive problems, dyspnea and back complaints were associated with poorer scores on the number of domains with problems, Groningen Activities Restriction Scale, MMSE or Geriatric Depression Scale.

Conclusion

One third of the participants reported no hindering complaints. Problems with walking/standing, pain, and weakness/tiredness were most reported, but not always found in electronic patient registers. A higher number of, and specific self-reported hindering complaints, were associated with poorer scores on functional outcomes. It may be helpful for general practitioners to ask about these complaints and their influence on daily life.     

Long-wavelength sensitive visual pigments of the guppy (<Emphasis Type="Italic">Poecilia reticulata</Emphasis>): six opsins expressed in a single individual

Background

The diversity of visual systems in fish has long been of interest for evolutionary biologists and neurophysiologists, and has recently begun to attract the attention of molecular evolutionary geneticists. Several recent studies on the copy number and genomic organization of visual pigment proteins, the opsins, have revealed an increased opsin diversity in fish relative to most vertebrates, brought about through recent instances of opsin duplication and divergence. However, for the subfamily of opsin genes that mediate vision at the long-wavelength end of the spectrum, the LWS opsins, it appears that most fishes possess only one or two loci, a value comparable to most other vertebrates. Here, we characterize the LWS opsins from cDNA of an individual guppy, Poecilia reticulata, a fish that is known exhibit variation in its long-wavelength sensitive visual system, mate preferences and colour patterns.

Results

We identified six LWS opsins expressed within a single individual. Phylogenetic analysis revealed that these opsins descend from duplication events both pre-dating and following the divergence of the guppy lineage from that of the bluefin killifish, Lucania goodei, the closest species for which comparable data exists. Numerous amino acid substitutions exist among these different LWS opsins, many at sites known to be important for visual pigment function, including spectral sensitivity and G-protein activation. Likelihood analyses using codon-based models of evolution reveal significant changes in selective constraint along two of the guppy LWS opsin lineages.

Conclusion

The guppy displays an unusually high number of LWS opsins compared to other fish, and to vertebrates in general. Observing both substitutions at functionally important sites and the persistence of lineages across species boundaries suggests that these opsins might have functionally different roles, especially with regard to G-protein activation. The reasons why are currently unknown, but may relate to aspects of the guppy's behavioural ecology, in which both male colour patterns and the female mate preferences for these colour patterns experience strong, highly variable selection pressures.

     

Genome sequence of the stramenopile <Emphasis Type="Italic">Blastocystis</Emphasis>, a human anaerobic parasite

Background

Blastocystis is a highly prevalent anaerobic eukaryotic parasite of humans and animals that is associated with various gastrointestinal and extraintestinal disorders. Epidemiological studies have identified different subtypes but no one subtype has been definitively correlated with disease.

Results

Here we report the 18.8 Mb genome sequence of a Blastocystis subtype 7 isolate, which is the smallest stramenopile genome sequenced to date. The genome is highly compact and contains intriguing rearrangements. Comparisons with other available stramenopile genomes (plant pathogenic oomycete and diatom genomes) revealed effector proteins potentially involved in the adaptation to the intestinal environment, which were likely acquired via horizontal gene transfer. Moreover, Blastocystis living in anaerobic conditions harbors mitochondria-like organelles. An incomplete oxidative phosphorylation chain, a partial Krebs cycle, amino acid and fatty acid metabolisms and an iron-sulfur cluster assembly are all predicted to occur in these organelles. Predicted secretory proteins possess putative activities that may alter host physiology, such as proteases, protease-inhibitors, immunophilins and glycosyltransferases. This parasite also possesses the enzymatic machinery to tolerate oxidative bursts resulting from its own metabolism or induced by the host immune system.

Conclusions

This study provides insights into the genome architecture of this unusual stramenopile. It also proposes candidate genes with which to study the physiopathology of this parasite and thus may lead to further investigations into Blastocystis-host interactions.

     

Functional and evolutionary consequences of cranial fenestration in birds

Ostrich‐like birds (Palaeognathae) show very little taxonomic diversity while their sister taxon (Neognathae) contains roughly 10,000 species. The main anatomical differences between the two taxa are in the crania. Palaeognaths lack an element in the bill called the lateral bar that is present in both ancestral theropods and modern neognaths, and have thin zones in the bones of the bill, and robust bony elements on the ventral surface of their crania. Here we use a combination of modeling and developmental experiments to investigate the processes that might have led to these differences. Engineering‐based finite element analyses indicate that removing the lateral bars from a neognath increases mechanical stress in the upper bill and the ventral elements of the skull, regions that are either more robust or more flexible in palaeognaths. Surgically removing the lateral bar from neognath hatchlings led to similar changes. These results indicate that the lateral bar is load‐bearing and suggest that this function was transferred to other bony elements when it was lost in palaeognaths. It is possible that the loss of the load‐bearing lateral bar might have constrained diversification of skull morphology in palaeognaths and thus limited taxonomic diversity within the group.     

OpenADAM: an open source genome-wide association data management system for Affymetrix SNP arrays

Background

The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome c oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).

Results

We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.

Conclusion

In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.     

Functional principles of steerable multi‐element probes in insects

Hemipterans, mosquitoes, and parasitic wasps probe in a variety of substrates to find hosts for their larvae or food sources. Probes capable of sensing and precise steering enable insects to navigate through solid substrates without visual information and to reach targets that are hidden deep inside the substrate. The probes belong to non‐related taxa and originate from abdominal structures (wasps) or mouthparts (hemipterans and mosquitoes), but nevertheless share several morphological characteristics. Although the transport function clearly differs (egg laying and acquisition of liquid food), the functional demands on the mechanical behaviour of the probe within the substrate tend to be similar. The probe needs to be thin to limit substrate deformation, and long, in order to attain substantial path lengths or depths. We linked the morphology across taxa to the different functional requirements, to provide insights into the biology of probing insects and the evolution of their probes. Current knowledge of insect probes is spread over many taxa, which offers the possibility to derive general characteristics of insect probing. Buckling during initial puncturing is limited by external support mechanisms. The probe itself consist of multiple (3–6) parts capable of sliding along one another. This multi‐part construction presumably enables advancement and precise three‐dimensional steering of the probe through the substrate with very low net external pushing forces, preventing buckling during substrate penetration. From a mechanical viewpoint, a minimum of three elements is required for 3D steering and volumetric exploration, as realised in the ovipositors of wasps. More elements, such as in six‐element probes of mosquitoes, may enhance friction in soft substrates. Alternatively, additional elements can have functions other than ‘drilling’, such as saliva injection in mosquitoes. Despite the gross similarities, probes show differences in their cross sections, tip morphologies, relative lengths of their elements, and the shape of their interconnections. The hypothesis is that the probe morphology is influenced by the substrate properties, which are mostly unknown. Correlating the observed diversity to substrate‐specific functional demands is therefore currently impossible. We conclude that a multipart probe with sliding elements is highly effective for volumetric substrate probing. Shared functional demands have led to an evolutionary convergence of slender multi‐element probes in disparate insect taxa. To fully understand 3D probing, it is necessary to study the sensory and material properties, as well as the detailed kinematics and dynamics of the various probes in relation to the nature of the selective pressure originating from the species‐specific substrates. Such knowledge will deepen our understanding of probing mechanisms and may support the development of slender, bio‐inspired probes.