Predicting which older adults will or will not fall using the Fullerton Advanced Balance scale

OBJECTIVE

The purpose of this study was to determine if the Fullerton Advanced Balance (FAB) scale can predict faller status in a group of independently functioning older adults.

DESIGN

A cross-sectional design was used to establish the sensitivity and specificity of the FAB scale to predict faller status based on a retrospective self-reported fall history. For the purpose of this study, a faller was classified as an older adult with a history of 2 or more falls in the previous 12 months.

SETTING

Multipurpose senior centers in an urban community.

PARTICIPANTS

A sample of independently functioning older adults (N=192; mean age+/-SD, 77+/-6.5 y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

FAB scale, a retrospective history of falls.

RESULTS

Binary logistic regression analysis indicated that the total FAB scale score could be used to predict faller status (as determined by a retrospective self-reported fall history). In the present sample, the probability of falling increased by 8% with each 1-point decrease in total FAB scale score. Receiver operating characteristic analysis determined that a cut-off score of 25 out of 40 on the FAB scale produced the highest sensitivity (74.6%) and specificity (52.6%) in predicting faller status. Five individual test items on the FAB scale were particularly predictive of faller status and could be combined to form a short version of the scale that may be even more predictive of faller status and require less time to administer.

CONCLUSIONS

The FAB scale is a predictive measure of faller status when used with independently functioning older adults. A practitioner can be confident in more than 7 out of 10 cases that an older adult who scores 25 or lower on the FAB scale is at high risk for falls and in need of immediate intervention.

Building an infrastructure to prevent falls in older Californians: the Fall Prevention Center of Excellence

The Fall Prevention Center of Excellence (Center), a consortium of federal, state, and private organizations, was established in 2005 to guide the implementation of a statewide initiative to prevent falls among older Californians. The process began with the convening of a representative group of recognized leaders in California's health and human services in 2003. This group engaged in a 2-day strategic planning process that culminated in the development of the California Blueprint for Fall Prevention. The overarching goal of the Blueprint is to build a statewide infrastructure for fall prevention services and programs that will serve as a model for the rest of the country. The specific goals of the Center are to establish fall prevention as a key public health priority in California; create, test, and evaluate effective and sustainable fall prevention programs; and build a comprehensive and sustainable fall prevention system in California. To accomplish these goals, the Center is currently engaged in developing and disseminating fall prevention tools and informational resources directed at the needs of both consumer and professional audiences; linking organizations involved in fall prevention while increasing awareness of fall prevention as an important public health issue; and helping communities build their capacity to effectively address falls in older adults through the delivery of integrated fall prevention services and "best practice" programs.

Preventing falls among older adults: no "one size suits all" intervention strategy

Physical activity (exercise) serves primary, secondary, and tertiary roles in the prevention of falls among older adults. In its primary role, physical activity can prevent the onset of pathology and system impairments that lead to disability and increased risk for falls. Slowing the progression of disease and system impairments is its secondary role, while its tertiary role lies in the restoration of function to a level that allows for more autonomy in the performance of essential activities of daily living. Whether used as a stand-alone strategy or a core component of a multifactorial intervention approach, exercise constitutes an effective means by which to reduce fall risk and/or fall incidence rates. At low levels of risk, many exercise choices are available to older adults. As the level of risk increases, however, more tailored and progressive exercise programs that target the physical risk factors associated with falls are more effective in lowering fall risk. Adopting a multifactorial intervention approach with exercise as an integral component may also be necessary at the highest levels of risk. Although more labor intensive, multifactorial approaches, if carefully staged, should still be considered the most effective intervention approach for older adults identified at high risk for falls.

Emerging model systems in evo-devo: horned beetles and the origins of diversity

Horned beetles and beetle horns are emerging as a model system suited to address fundamental questions in evolutionary developmental biology. Here we briefly review the biology of horned beetles and highlight the unusual opportunities they provide for evo-devo research. We then summarize recent advances in the development of new approaches and techniques that are now available to scientists interested in working with these organisms. We end by discussing ways to implement and combine these new approaches to explore new frontiers in evo-devo research previously unavailable to reseachers working outside traditional model organisms.

Development of a multidimensional balance scale for use with functionally independent older adults

OBJECTIVE

To develop and evaluate the validity and reliability of a multidimensional balance scale-the Fullerton Advanced Balance (FAB) scale-suitable for use with functionally independent older adults.

DESIGN

Psychometric evaluation of the scale's content and convergent validity, test-retest and intra- and interrater reliability, and internal rater consistency.

SETTING

Urban community.

PARTICIPANTS

Forty-six community-residing older adults (mean +/- standard deviation, 75 +/- 6.2 y), with (n = 31) and without identified balance problems (n = 15), participated in the study. Four physical therapists with expertise in the assessment and treatment of balance disorders in older adults also participated in the content validity and/or reliability phases of the study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Spearman rank correlation coefficients for convergent validity, test-retest, intra- and interrater reliability, and homogeneity coefficient values for rater consistency.

RESULTS

Test-retest reliability for the total balance scale score was high (rho = .96). Interrater reliability for total score ranged from .94 to .97 whereas intrarater reliability coefficients ranged from .97 to 1.00. Homogeneity (H) coefficients were greater than .90 for 6 of the 10 individual test items and all 10 test items had H coefficients of greater than .75 for both rating sessions.

CONCLUSIONS

Preliminary results suggest that the FAB scale is a valid and reliable assessment tool that is suitable for use with functionally independent older adults residing in the community.

Nucleotide sequence analysis of the enteropathogenic Escherichia coli adherence factor plasmid pMAR7

The complete nucleotide sequence was determined for pMAR7, an enteropathogenic Escherichia coli (EPEC) adherence factor (EAF) plasmid that contains genes encoding a type IV attachment pilus (Bfp) and the global virulence regulator per. Prototypic EAF plasmid pMAR7 is self-transmissible, unlike the smaller EAF plasmid pB171, which has no genes encoding conjugative functions. The tra locus, a highly conserved 33-kb segment found in pMAR7, is similar to the tra (conjugation) region of the F plasmid. ISEc13 copies flanking the pMAR7 tra region could potentially mobilize or delete the tra genes. Hybridization of 134 EPEC strains showed that a complete tra region is present only in strains of the EPEC1 clonal group. This study confirms EPEC's potential for dissemination of virulence attributes by horizontal transfer of the EAF plasmid.

Functional analysis of cytoplasmic dynein heavy chain in Caenorhabditis elegans with fast-acting temperature-sensitive mutations

Cytoplasmic dynein, a minus-end-directed microtubule motor, has been implicated in many cellular and developmental processes. Identification of specific cellular processes that rely directly on dynein would be facilitated by a means to induce specific and rapid inhibition of its function. We have identified conditional variants of a Caenorhabditis elegans dynein heavy chain (DHC-1) that lose function within a minute of a modest temperature upshift. Mutant embryos generated at elevated temperature show defects in centrosome separation, pronuclear migration, rotation of the centrosome/nucleus complex, bipolar spindle assembly, anaphase chromosome segregation, and cytokinesis. Our analyses of mutant embryos generated at permissive temperature and then upshifted quickly just before events of interest indicate that DHC-1 is required specifically for rotation of the centrosome/nucleus complex, for chromosome congression to a well ordered metaphase plate, and for timely initiation of anaphase. Our results do not support the view that DHC-1 is required for anaphase B separation of spindle poles and chromosomes. A P-loop mutation identified in two independent dominant temperature-sensitive alleles of dhc-1, when engineered into the DHC1 gene of Saccharomyces cerevisiae, conferred a dominant temperature-sensitive dynein loss-of-function phenotype. This suggests that temperature-sensitive mutations can be created for time-resolved function analyses of dyneins and perhaps other P-loop proteins in a variety of model systems.

Loss of KLP-19 polar ejection force causes misorientation and missegregation of holocentric chromosomes

Holocentric chromosomes assemble kinetochores along their length instead of at a focused spot. The elongated expanse of an individual holocentric kinetochore and its potential flexibility heighten the risk of stable attachment to microtubules from both poles of the mitotic spindle (merotelic attachment), and hence aberrant segregation of chromosomes. Little is known about the mechanisms that holocentric species have evolved to avoid this type of error. Our studies of the influence of KLP-19, an essential microtubule motor, on the behavior of holocentric Caenorhabditis elegans chromosomes suggest that it has a major role in combating merotelic attachments. Depletion of KLP-19, which associates with nonkinetochore chromatin, allows aberrant poleward chromosome motion during prometaphase, misalignment of holocentric kinetochores, and multiple anaphase chromosome bridges in all mitotic divisions. Time-lapse movies of GFP-labeled mono- and bipolar spindles demonstrate that KLP-19 generates a force on relatively stiff holocentric chromosomes that pushes them away from poles. We hypothesize that this polar ejection force minimizes merotelic misattachment by maintaining a constant tension on pole-kinetochore connections throughout prometaphase, tension that compels sister kinetochores to face directly toward opposite poles.

Genome of bacteriophage P1

P1 is a bacteriophage of Escherichia coli and other enteric bacteria. It lysogenizes its hosts as a circular, low-copy-number plasmid. We have determined the complete nucleotide sequences of two strains of a P1 thermoinducible mutant, P1 c1-100. The P1 genome (93,601 bp) contains at least 117 genes, of which almost two-thirds had not been sequenced previously and 49 have no homologs in other organisms. Protein-coding genes occupy 92% of the genome and are organized in 45 operons, of which four are decisive for the choice between lysis and lysogeny. Four others ensure plasmid maintenance. The majority of the remaining 37 operons are involved in lytic development. Seventeen operons are transcribed from sigma(70) promoters directly controlled by the master phage repressor C1. Late operons are transcribed from promoters recognized by the E. coli RNA polymerase holoenzyme in the presence of the Lpa protein, the product of a C1-controlled P1 gene. Three species of P1-encoded tRNAs provide differential controls of translation, and a P1-encoded DNA methyltransferase with putative bifunctionality influences transcription, replication, and DNA packaging. The genome is particularly rich in Chi recombinogenic sites. The base content and distribution in P1 DNA indicate that replication of P1 from its plasmid origin had more impact on the base compositional asymmetries of the P1 genome than replication from the lytic origin of replication.

Sensory Organization Abilities During Upright Stance in Late-Onset Alzheimer's-Type Dementia

Postural stability was compared between individuals with mild and moderate Alzheimer's dementia and healthy older adults, using the Sensory Organization Test. Interestingly, the moderate group performed more like the healthy group than the mild group. Significant differences (p </= .008) in postural stability were found between the mild group and both the healthy and moderate Alzheimer's groups when vestibular information was critical for stability. Additional differences were found between the healthy and mild groups when vision was inaccurate. These findings suggest a decreased visual dependence in the later stages of the illness, possibly due to the visual disturbances associated with disease progression.

State of the art

Many falls and injuries related to falls can be prevented with existing knowledge and technology. But effective fall prevention will require the collaborative efforts of many organizations as well as changes in the behavior of older adults and providers, and systematic changes in organizations. Many effective interventions currently exist, but improved access, additional resources, and coordination and commitment across systems are needed. In summary, we know how to prevent falls and reduce injuries, using proven intervention strategies aimed at both low-risk and high-risk older adults. There is a wide spectrum of screening and assessment tools available and effective intervention practices. The challenge now is to put into practice throughout California the state-of-the art knowledge that has already been compiled through innovative programs and rigorous research.

A map of the interactome network of the metazoan C. elegans

To initiate studies on how protein-protein interaction (or "interactome") networks relate to multicellular functions, we have mapped a large fraction of the Caenorhabditis elegans interactome network. Starting with a subset of metazoan-specific proteins, more than 4000 interactions were identified from high-throughput, yeast two-hybrid (HT=Y2H) screens. Independent coaffinity purification assays experimentally validated the overall quality of this Y2H data set. Together with already described Y2H interactions and interologs predicted in silico, the current version of the Worm Interactome (WI5) map contains approximately 5500 interactions. Topological and biological features of this interactome network, as well as its integration with phenome and transcriptome data sets, lead to numerous biological hypotheses.

The export of coat protein from enteroaggregative Escherichia coli by a specific ATP-binding cassette transporter system

Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen characterized by aggregative adherence (AA) to cultured human mucosal epithelium cells. We have recently characterized a 10.2-kDa protein, called dispersin, which is exported from the bacteria and which promotes dispersal of EAEC across the intestinal mucosa. Here, we present evidence that dispersin is exported by a putative ABC transporter complex, which is encoded by a genetic locus of the EAEC virulence plasmid pAA2. We demonstrate that the locus comprises a cluster of five genes (designated aat-PABCD), including homologs of an inner-membrane permease (AatP), an ATP-binding cassette protein (AatC) and the outer membrane protein TolC (AatA). We show that, like TolC, AatA localizes to the outer membrane independently of its ABC partner. Dispersin appears to require the Aat complex for outer membrane translocation but not for secretion across the inner membrane. We also show that, like the dispersin gene, transcription of the aat cluster is dependent on AggR, a regulator of virulence genes in EAEC. We propose that the aat cluster encodes a specialized ABC transporter, which plays a role in the pathogenesis of EAEC by transporting dispersin out of the bacterial cell.

Complete genome sequence and comparative genomics of Shigella flexneri serotype 2a strain 2457T

We determined the complete genome sequence of Shigella flexneri serotype 2a strain 2457T (4,599,354 bp). Shigella species cause >1 million deaths per year from dysentery and diarrhea and have a lifestyle that is markedly different from those of closely related bacteria, including Escherichia coli. The genome exhibits the backbone and island mosaic structure of E. coli pathogens, albeit with much less horizontally transferred DNA and lacking 357 genes present in E. coli. The strain is distinctive in its large complement of insertion sequences, with several genomic rearrangements mediated by insertion sequences, 12 cryptic prophages, 372 pseudogenes, and 195 S. flexneri-specific genes. The 2457T genome was also compared with that of a recently sequenced S. flexneri 2a strain, 301. Our data are consistent with Shigella being phylogenetically indistinguishable from E. coli. The S. flexneri-specific regions contain many genes that could encode proteins with roles in virulence. Analysis of these will reveal the genetic basis for aspects of this pathogenic organism's distinctive lifestyle that have yet to be explained.

Comparative genomics of Salmonella enterica serovar Typhi strains Ty2 and CT18

We present the 4.8-Mb complete genome sequence of Salmonella enterica serovar Typhi strain Ty2, a human-specific pathogen causing typhoid fever. A comparison with the genome sequence of recently isolated S. enterica serovar Typhi strain CT18 showed that 29 of the 4,646 predicted genes in Ty2 are unique to this strain, while 84 genes are unique to CT18. Both genomes contain more than 200 pseudogenes; 9 of these genes in CT18 are intact in Ty2, while 11 intact CT18 genes are pseudogenes in Ty2. A half-genome interreplichore inversion in Ty2 relative to CT18 was confirmed. The two strains exhibit differences in prophages, insertion sequences, and island structures. While CT18 carries two plasmids, one conferring multiple drug resistance, Ty2 has no plasmids and is sensitive to antibiotics.

Extensive mosaic structure revealed by the complete genome sequence of uropathogenic Escherichia coli

We present the complete genome sequence of uropathogenic Escherichia coli, strain CFT073. A three-way genome comparison of the CFT073, enterohemorrhagic E. coli EDL933, and laboratory strain MG1655 reveals that, amazingly, only 39.2% of their combined (nonredundant) set of proteins actually are common to all three strains. The pathogen genomes are as different from each other as each pathogen is from the benign strain. The difference in disease potential between O157:H7 and CFT073 is reflected in the absence of genes for type III secretion system or phage- and plasmid-encoded toxins found in some classes of diarrheagenic E. coli. The CFT073 genome is particularly rich in genes that encode potential fimbrial adhesins, autotransporters, iron-sequestration systems, and phase-switch recombinases. Striking differences exist between the large pathogenicity islands of CFT073 and two other well-studied uropathogenic E. coli strains, J96 and 536. Comparisons indicate that extraintestinal pathogenic E. coli arose independently from multiple clonal lineages. The different E. coli pathotypes have maintained a remarkable synteny of common, vertically evolved genes, whereas many islands interrupting this common backbone have been acquired by different horizontal transfer events in each strain.