Association of muscle power with functional status in community-dwelling elderly women

BACKGROUND

Identification of the physiologic factors most relevant to functional independence in the elderly population is critical for the design of effective interventions. It has been suggested that muscle power may be more directly related to impaired physical performance than muscle strength in elderly persons. We tested the hypothesis that peak muscle power is closely associated with self-reported functional status in sedentary elderly community-dwelling women.

METHODS

We used baseline data that were collected as part of a 1-year randomized controlled clinical trial of a combined program of strength, power, and endurance training in 80 elderly women (mean age 74.8 +/- 5.0 years) with 3.2 +/- 1.9 chronic diseases, selected for baseline functional impairment and/or falls.

RESULTS

Functional status at baseline was related in univariate analyses to physiologic capacity, habitual physical activity level, neuropsychological status, and medical diagnoses. Leg power had the strongest univariate correlation to self-reported functional status (r = -.47, p < .0001) of any of the physiologic factors we tested. In a forward stepwise regression model, leg press power and habitual physical activity level were the only two factors that contributed independently to functional status (r = .64, p < .0001), accounting for 40% of the variance in functional status.

CONCLUSIONS

Leg power is a strong predictor of self-reported functional status in elderly women.

An optimization of the Waterlow score using regression and artificial neural networks

OBJECTIVES

To optimize the ability of the Waterlow Scale to predict individuals vulnerable to developing pressure ulcers.

DESIGN

Prospective cohort study.

SETTING

Two acute care UK National Health Service (NHS) providers.

SUBJECTS

Four hundred and twenty-two inpatients across five specialities (general medicine, general surgery, orthopaedics, oncology and rehabilitation).

INTERVENTIONS

Waterlow scores recorded weekly for 14 days post admission to hospital.

MAIN OUTCOME MEASURE

Development of a pressure ulcer.

RESULTS

Nonlinear analysis using neural networks did not outperform linear methods. Only five items out of 11 in the Waterlow Scale appeared to have any classification ability in this patient population.

CONCLUSIONS

The Waterlow score when modelled as a linear equation appears as effective as more complicated nonlinear mappings using neural networks. Only a subset of the variables of the Waterlow Scale have predictive value in this patient population, but this is a different subset to those found in a previous study of a different client group (wheelchair users).

Fast, all-optical Rayleigh wave microscope: imaging on isotropic and anisotropic materials

A fast, non-contact Rayleigh wave scanning microscope is demonstrated, which is capable of scan rates of up to a maximum of 1000 measurements/s with typical speeds of up to 250 measurements/s on real samples. The system uses a mode-locked, Q-switched Nd:YAG laser operating at a mode-locked frequency of 82 MHz and a Q-switch frequency of 1 kHz. The Q-switch frequency determines the upper limit of the scanning rate. The generating laser illumination is delivered and controlled by a computer-generated hologram (CGH). The generating laser produces around 30 pulses at 82 MHz and additional harmonics at 164 and 246 MHz and above. The microscope can operate at these harmonics provided the spatial bandwidth of the optics and the temporal bandwidth of the electronics are suitable. The ultrasound is detected with a specialized knife-edge detector. The microscope has been developed for imaging on isotropic materials. Despite this, the system can be used on anisotropic materials, but imaging and interpreting images can be difficult. The anisotropy and grain structure of the material can distort the Rayleigh wavefront, leading to signal loss. A model has been developed to simulate polycrystalline-anisotropic materials; this is discussed along with possible solutions that would overcome the problems associated with anisotropy. Rayleigh wave amplitude images are demonstrated on silicon nitride at 82 and 164 MHz and on polycrystalline aluminium at 82 MHz.

Molecular effects of topoisomerase II inhibitors in AML cell lines: correlation of apoptosis with topoisomerase II activity but not with DNA damage

We examined the cellular effects of topo II inhibitors in two human myeloid cell lines, HL-60 and KG-1 cells, with the purpose of finding molecular markers for the sensitivity of leukemia cells to topo II inhibitors. These cell lines are widely used, well characterized and they differ in their sensitivities to topo II inhibitors. Despite the fact that HL-60 cells are p53-negative, they are much more sensitive than KG-1 cells. Three different topo II inhibitors with distinct molecular ways of action have been used. Daunorubicin and aclarubicin are DNA intercalators that secondarily interact with topo II; etoposide, on the other hand, directly binds to the enzyme. In contrast to daunorubicin, which induces protein-associated DNA double-strand breaks due to the blockage of topo II action, aclarubicin inhibits the access of DNA by topo II. No correlation could be established between the drug-induced DNA damage and apoptosis. In fact, the amount and pattern of DNA damage examined with the 'comet assay' was characteristic for each drug in both cell lines. The DNA binding of daunorubicin was slightly higher in HL-60 cells, but there was no notable variance between the cell lines for aclarubicin. The most striking difference could be found for the nuclear topo II activity, which was about half in KG-1 cells and, additionally, less than 1% of the nuclear topo II activity was bound to the DNA in KG-1 cells when compared to HL-60 cells. This fraction of topo II interacts with the inhibitors; subsequently these findings might well explain the variance in the cellular sensitivity. Additional factors are alterations of the apoptotic pathways, eg loss of p53 in HL-60 cells. Although we found no differences in the quantity of DNA damage between the cell lines after drug treatment, the quality of DNA damage appeared to be distinct for each topo II inhibitor. The morphological appearance of the comet tails after treatment was characteristic for each drug. Further studies are necessary to decide whether these in vitro data are compatible with the clinical situation.

Two-dimensional, three-dimensional, and gray-scale images reconstructed from computer-generated holograms designed by use of a direct-search method

A direct-search method for the computer design of holograms is demonstrated. Two-dimensional, three-dimensional, and containing holograms with different levels of intensity (gray scales) were designed, fabricated, and optically reconstructed. The number of effective gray levels and the image-intensity noise and contrast are discussed. A modification of the state-variables cost function used in the direct-search algorithm that permits reliable control of gray scales is presented. Optical reconstructions of two-dimensional, three-dimensional, and gray-scale binary phase computer-generated holograms are presented.

Access to health care services among people with disabilities receiving Medicaid

Few data exist describing Medicaid's success in providing health care services to people with disabilities. The access to care survey from the Medical Expenditures Panel Survey was used to collect access data from 502 individuals with disabilities in central Missouri receiving Medicaid under fee-for-service reimbursement. Nearly all of the respondents had a usual source of care, but two-thirds reported difficulties obtaining a needed health care service. Dental, optometric, and personal assistance services were most difficult to obtain. Provider non-participation, non-coverage of a service, and coverage restrictions were the most frequently cited barriers to obtaining care. Results suggest that people with disabilities have difficulty accessing needed health care services through the Missouri Medicaid fee-for-service system.

Linkage between male infertility and trinucleotide repeat expansion in the androgen-receptor gene

BACKGROUND

Androgens acting via the androgen receptor bring about stimulation and maintenance of spermatogenesis. If mutations in the androgen-receptor gene interfere with the receptor's function, this effect may partly account for impaired spermatogenesis. We aimed to find out whether expansion of a trinucleotide repeat in the androgen-receptor gene is associated with male infertility.

METHODS

We analysed 67 coded semen and blood samples from a predominantly white group of male infertility patients and controls. Clinical analyses included cause of infertility, sperm count, and reproductive hormone concentrations. Analysis of trinucleotide (CAG) repeat length and point mutations in the androgen-receptor gene was done by PCR, single-stranded conformational polymorphism, and DNA sequencing.

FINDINGS

Screening and characterisation of the androgen-receptor gene in 35 patients and 32 controls showed no point mutations in the gene. 30 of the infertile patients had idiopathic azoospermia or oligozoospermia, and these men had significantly longer CAG repeat tracts than controls (mean 23.2 [SE 0.7] vs 20.5 [0.3], p=0.0001). The odds of having CAG repeat lengths of 20 were six-fold higher for fertile men than for men with a spermatogenic disorder.

INTERPRETATION

Our results indicate a relation between CAG repeat length in the androgen-receptor gene and the risk of defective spermatogenesis. With the use of intracytoplasmic sperm injection, this mutation could be inherited, possibly leading to an increase in male infertility in future generations. Should further elongation of the CAG repeat occur in these future generations, there is an added risk of increased severity of male infertility, and potentially an increased incidence of neurodegenerative disease.

CT of intranasal pleomorphic adenoma

Intranasal pleomorphic adenoma is rare. We report the CT features this tumor in a 41-year-old woman who presented to us with right nasal obstruction and a 2-day history of epistaxis.

Apraxia differs in corticobasal degeneration and left-parietal stroke: A case study

Corticobasal degeneration (CBD) is a progressive disorder characterized by both cortical and basal ganglia dysfunction such as asymmetrical apraxia, and akinetic rigidity, involuntary movements, and cortical sensory loss. Although apraxia is a key finding for the differential diagnosis of CBD, it has not been determined whether the features of apraxia seen in subjects with CBD are similar to those features exhibited by subjects with left-hemisphere damage from stroke. Therefore, for both clinical purposes and in order to better understand the brain mechanisms that lead to apraxia in CBD, we studied praxis in a patient with CBD and compared him to patients who are apraxic from left-parietal strokes. We used three-dimensional movement analyses to compare the features of apraxic movement. This subject with CBD was a dentist whose initial complaint had been that he "forgot" how to use his tools in the mouths of his patients. Analyses were performed on the trajectories made when using a knife to actually slice bread, and when repetitively gesturing slicing made to verbal command. Movements of the left hand, wrist, elbow, and shoulder were digitized in 3-D space. Although the CBD subject was clearly apraxic, the features of his apraxia differed markedly from those of the subjects with lesions in the left parietal lobe. For movements to command, the CBD subject showed joint coordination deficits, but his wrist trajectories were produced in the appropriate spatial plane, were correctly restricted to a single plane, and, like control subjects, were linear in path shape. However, when he was actually manipulating the tool and object, all of these aspects of his trajectories became impaired. In contrast, the deficits of the apraxic subjects with left-parietal damage were most pronounced to verbal command with their movements improving slightly although remaining impaired during actual tool and object manipulation. Unlike patients with parietal strokes, patients with CBD have degeneration in several systems and perhaps deficits in these other areas may account for the differences in praxic behavior.

Developing guidelines for pressure ulcer prevention and management

A review of the current pressure ulcer prevention guidelines.

Beds and mattresses

Many of the practices undertaken to prevent and treat pressure ulcers are contentious, based on estimates and guesses rather than evidence.1 One of the areas of greatest uncertainty, the role of pressure-redistributing support surfaces, has become a common foundation to pressure ulcer care. Since Hibbs2 described an ideal shopping list of support surfaces for a large combined acute and community care provider, special mattresses have been widely disseminated throughout health care services in the UK and beyond.1 This utilisation has not been inexpensive, with 7-8% of all pressure ulcer costs attributed to the acquisition of mattresses.3,4

Zebrafish tbx-c functions during formation of midline structures

Several genes containing the conserved T-box region in invertebrates and vertebrates have been reported recently. Here, we describe three novel members of the T-box gene family in zebrafish. One of these genes, tbx-c, is studied in detail. It is expressed in the axial mesoderm, notably, in the notochordal precursor cells immediately before formation of the notochord and in the chordoneural hinge of the tail bud, after the notochord is formed. In addition, its expression is detected in the ventral forebrain, sensory neurons, fin buds and excretory system. The expression pattern of tbx-c differs from that of the other two related genes, tbx-a and tbx-b. The developmental role of tbx-c has been analysed by overexpression of the full-length tbx-c mRNA and a truncated form of tbx-c mRNA, which encodes the dominant-negative Tbx-c. Overexpression of tbx-c causes expansion of the midline mesoderm and formation of ectopic midline structures at the expense of lateral mesodermal cells. In dominant-negative experiments, the midline mesoderm is reduced with the expansion of lateral mesoderm to the midline. These results suggest that tbx-c plays a role in formation of the midline mesoderm, particularly, the notochord. Moreover, modulation of tbx-c activity alters the development of primary motor neurons. Results of in vitro analysis in zebrafish animal caps suggest that tbx-c acts downstream of early mesodermal inducers (activin and ntl) and reveal an autoregulatory feedback loop between ntl and tbx-c. These data and analysis of midline (ntl−/− and flh−/−) and lateral mesoderm (spt−/−) mutants suggest that tbx-c may function during formation of the notochord.

The social ecology of syphilis

Factors affecting the transmission of syphilis can be categorized into those acting at the level of individuals (e.g., number of sex partners) and others at the level of the sociophysical environment (e.g., availability of treatment services for curable infections). In a prior study, we identified several sociophysical factors correlated with the ten-year mean syphilis rate in a regression analysis of United States counties. In the present study we used qualitative methods to investigate additional aspects of some factors in the regression, as well as to identify entirely new factors. Twelve counties with populations less than 100,000 and ten-year mean syphilis rates that were greater or less than expected by the regression model were selected for a three to five day visit. The case study protocol included observations, unstructured interviews with care providers and county residents, and a standardized questionnaire completed by state and local sexually transmitted disease control personnel pertaining to characteristics and practices of the local health department. Comparisons of the field notes and questionnaires revealed patterns of factors of the sociophysical environment that potentially affect county syphilis rates. These included access to the health department STD clinic, race relations, employment opportunities for minorities, interagency coordination, STD outreach activities, the social acceptability of discussing STDs, and intercommunity dynamics. In addition we noted the disproportionate influence of particular individuals on these factors. Some of the factors identified are readily quantifiable and could enhance the predictive power of multivariable models of county syphilis rates. The hypotheses generated by this study may also lead to a better measurement and understanding of potentially important environmental determinants of community syphilis rates, and the development of new or enhanced prevention strategies.

Analysis of the spermine synthase gene region in Fugu rubripes, Tetraodon fluviatilis, and Danio rerio

A prerequisite to understanding the evolution of the human X chromosome is the analysis of synteny of X-linked genes in different species. We have focused on the spermine synthase gene in human Xp22. 1. We show that whereas the human gene spans a genomic region of 54 kb, the Fugu rubripes gene is encompassed in a 4.7-kb region. However, we could not find conserved synteny between this region of human Xp22 and the equivalent F. rubripes region. A cosmid clone containing the F. rubripes gene does not contain other X-linked genes. Instead we identified homologs of human genes that are autosomally localized: the ryanodine receptor type I (RYRI), which is implicated in malignant hyperthermia and central core disease, and the HE6 gene. Comparison of the F. rubripes, Tetraodon fluviatilis, mouse, human, and Danio rerio 5'UTRs of spermine synthase highlights conserved sequences potentially involved in regulation. Interestingly, pseudogenes of this gene that are present in the human and mouse genomes seem to be absent in the compact F. rubripes genome. Analysis of a D. rerio PAC clone containing spermine synthase shows an intermediate genomic size in this fish. Sequence analysis of this PAC clone did not reveal other known genes: neither the RYRI gene, nor the HE6 gene, nor other human Xp22 genes were identified.

Primary structure, tissue distribution, and expression of mouse phosphoinositide-dependent protein kinase-1, a protein kinase that phosphorylates and activates protein kinase Czeta

Phosphoinositide-dependent protein kinase-1 (PDK1) is a recently identified serine/threonine kinase that phosphorylates and activates Akt and p70(S6K), two downstream kinases of phosphatidylinositol 3-kinase. To further study the potential role of PDK1, we have screened a mouse liver cDNA library and identified a cDNA encoding the enzyme. The predicted mouse PDK1 (mPDK1) protein contained 559 amino acids and a COOH-terminal pleckstrin homology domain. A 7-kilobase mPDK1 mRNA was broadly expressed in mouse tissues and in embryonic cells. In the testis, a high level expression of a tissue-specific 2-kilobase transcript was also detected. Anti-mPDK1 antibody recognized multiple proteins in mouse tissues with molecular masses ranging from 60 to 180 kDa. mPDK1 phosphorylated the conserved threonine residue (Thr402) in the activation loop of protein kinase C-zeta and activated the enzyme in vitro and in cells. Our findings suggest that there may be different isoforms of mPDK1 and that the protein is an upstream kinase that activates divergent pathways downstream of phosphatidylinositol 3-kinase.

Three receptor genes for plasminogen related growth factors in the genome of the puffer fish Fugu rubripes

Plasminogen related growth factors (PRGFs) and their receptors play major roles in embryogenesis, tissue regeneration and neoplasia. In order to investigate the complexity and evolution of the PRGF receptor family we have cloned and sequenced three receptors for PRGFs in the teleost fish Fugu rubripes, a model vertebrate with a compact genome. One of the receptor genes isolated encodes the orthologue of mammalian MET, whilst the other two may represent Fugu rubripes orthologues of RON and SEA. This is the first time three PRGF receptors have been identified in a single species.

Are topoisomerase II inhibitor-induced micronuclei in vitro a predictive marker for the compounds' ability to cause secondary leukemias after treatment?

The inhibition of topoisomerase II (topo II) is a very powerful principle of chemotherapy and topo II inhibiting drugs are the backbone of most chemotherapeutic strategies. However, secondary malignomas can occur after treatment. Typically, secondary acute myeloid leukemia (t-AML) after treatment with topo II inhibitors has a shorter latency period than t-AML following alkylator therapy. Fragments originating from chromosome breakage as well as whole chromosomes which are not correctly distributed during mitosis give rise to micronuclei in the next interphase. Micronucleus formation has become an important endpoint in genotoxicity testing. In an effort to test the suitability of the micronucleus assay for predictive purposes, we have analyzed three human tumor cell lines for cell growth as well as micronucleus induction after treatment with four clinically used topo II inhibitors. Micronuclei were induced at levels of low toxicity by etoposide, mitoxantrone, daunorubicin and idarubicin. The induction of micronuclei was a more sensitive indicator of drug effects than reduction in cell growth. Thus, micronucleus induction may assist in the prediction of the potency of a chemotherapeutic agent for induction of secondary malignomas.

The impact of pregnancy on eating behaviour and aspects of weight concern

BACKGROUND

Excessive weight gain in pregnancy and retention of this weight gain is a well known problem. How women with a history of dietary restraint adjust to being pregnant, is of interest, as pregnancy epitomises many of the factors known to trigger overeating.

OBJECTIVE

To examine the impact of pregnancy on eating behaviour and weight concern and the role of dietary restraint in mediating any changes.

METHODS

Primigravid (n = 50) and non-pregnant nulliparous (n = 50) women completed a questionnaire to describe their profile characteristics, current health behaviours, eating behaviour and weight concern. The pregnant women completed additional retrospective items relating to these factors for the period prior to their pregnancy.

RESULTS

The pregnant women reported eating more, showed lower levels of dietary restraint, were less dissatisfied with their body shape and showed higher eating self efficacy than non-pregnant women. Compared to the months prior to their pregnancy, the pregnant women rated themselves as less restrained in their eating behaviour and nearly half stated that they were eating more. In terms of the impact of pre pregnancy levels of dietary restraint, the results showed a significant interaction between restrained eating and pregnancy for both hunger and eating self efficacy. The results showed that the restrained eaters, when pregnant, rated themselves as significantly less hungry and reported less difficulty controlling their food intake than the non pregnant restrained eaters but showed comparable hunger and eating control to the other groups. The results showed no effect of restrained eating on weight change.

CONCLUSION

The results suggest that pregnancy both legitimises increased food intake and removes any previous intentions to eat less.

Evaluation of the provision of fieldwork training through a rural student unit

A Rural Student Unit was established as a pilot project to trial a model of rural fieldwork placement provision. The Unit aimed to increase the number of student placements available in rural areas and provide undergraduate students with a positive fieldwork experience. The results indicate that the Unit was successful in overcoming some of the barriers to rural fieldwork, for both students and supervisors, and substantially increased the number of students undertaking fieldwork in this area. The results support the further trialing and expansion of the model.

Identification of a form of acyl-CoA:cholesterol acyltransferase specific to liver and intestine in nonhuman primates

The present study demonstrates that two different forms of the intracellular cholesterol esterification enzyme acyl-CoA:cholesterol acyltransferase (ACAT) are present in the nonhuman primate hepatocyte; one is similar to that originally cloned from human genomic DNA, here termed ACAT1, while a second gene product, termed ACAT2, is reported here. The primate ACAT2 gene product was cloned from an African green monkey liver cDNA library. Sequence analysis of an isolated, full-length clone of ACAT2 cDNA identified an open reading frame encoding a 526-amino acid protein with essentially no sequence similarity to the ACAT1 cDNA over the N-terminal 101 amino acids but with 57% identity predicted over the remaining 425 amino acids. Transfection of the cloned ACAT2 cDNA into two different mammalian cell types resulted in the production of abundant ACAT activity which was sensitive to ACAT inhibitors. Northern blot analysis showed that the ACAT2 mRNA was expressed primarily in liver and intestine in monkeys. In contrast, ACAT1 mRNA was expressed in almost all tissues examined. Topologic predictions from the amino acid sequence of ACAT2 indicates that it has seven trans-membrane domains in a configuration that places the putative active site of the enzyme in the lumen of the endoplasmic reticulum. This orientation of ACAT2 in the endoplasmic reticulum membrane, in addition to its expression only in liver and intestine, suggests that this enzyme may have as a primary function, the secretion of cholesteryl esters into apoB-containing lipoproteins.

Repositioning to prevent pressure sores--what is the evidence?

The prevention of pressure sores by frequent repositioning of patients is a widely accepted practice. In this article, the author questions whether this should be so and suggests that there may be more effective ways of relieving pressure damage.