bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient transformation of Arabidopsis leaf protoplasts: a versatile experimental system to study gene expression
Authors: Abel Steffen , Theologis Athanasios
Published: November 2004

An improved protocol is reported to isolate and transiently transform mesophyll protoplasts of Arabidopsis thaliana. Transfected leaf protoplasts support high levels of expression of the bacterial reporter gene coding for β‐glucuronidase (GUS), under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Transient expression of GUS activity was monitored spectrophotometrically and reached a maximum between 18 and 48 h after polyethylene glycol (PEG)‐mediated DNA uptake. Histochemical staining for GUS activity revealed reproducible transformation frequencies between 40 and 60%, based on the number of protoplasts survived. To demonstrate the applicability of the transient expression system, the subcellular localization of GUS proteins tagged with different nuclear polypeptides was studied in transfected mesophyll protoplasts, revealing nuclear compartmentalization of the chimeric GUS enzymes. Furthermore, Arabidopsis mesophyll protoplasts support auxin‐mediated induction of chloramphenicol acetyl‐transferase (CAT) activity when transfected with a transcriptional fusion between the CAT reporter gene and the early auxin‐inducible PS‐IAA4/5 promoter. Hence, the method allows in vivo analysis of promoter activity and subcellular localization of fusion proteins in a homologous transformation system.
Sequencing, processing, and localization of the petunia CMS‐associated mitochondrial protein
Authors: Nivison Helen T. , Sutton Claudia A. , Wilson Robin K. , Hanson Maureen R.
Published: November 2004

The petunia mitochondrial fused gene (pcf), which is associated with cytoplasmic male sterility (CMS), is composed of sequences derived from atp9, coxll, and an unidentified reading frame termed urfS. Pcf transcripts are modified by editing at 11 sites. Codon usage and nearest neighbor analysis suggest that the urfS region is not derived originally from a plant mitochondrial coding region. Although the gene contains an open reading frame coding for a 43 kDa protein, a 25 kDa gene product has previously been identified (Nivison and Hanson, 1989). N‐terminal sequencing revealed that the 25 kDa protein is encoded within the urfS portion of pcf and that its actual molecular mass is 19.5 kDa. Through pulse‐chase labeling of protein in isolated mitochondria, the 25 kDa protein was found to be processed from a 43 kDa precursor protein representing the entire pcf gene sequence. Antibodies to synthetic peptides encoded by the atp9 and coxll portions of pcf recognized petunia ATP9 or COXII but no other mitochondrial proteins on immunoblots. Controlled proteolysis experiments showed that both the 43 kDa precursor and the 25 kDa protein are soluble or loosely associated with membranes. Thus, the 25 kDa protein appears to be the only pcf‐encoded protein that accumulates in mitochondria.
Distribution of xylosylation and fucosylation in the plant Golgi apparatus
Authors: Fitchette‐Lainé Anne‐Catherine , Gomord Véronique , Chekkafi Aïcha , Faye Loïc
Published: November 2004

Antibodies have been immunopurified which are specific for carbohydrate epitopes containing the β1→2 xylose or α1→3 fucose residues found on complex N‐linked glycans in plants. The antibody specificity was determined by taking advantage of an Arabidopsis thaliana N‐glycosylation mutant which lacks N‐acetyl‐glucosaminyltransferase I and is unable to synthesize complex glycans. These antibodies were used to immunolocalize xylose‐ and fucose‐containing glycoproteins in suspension‐cultured sycamore cells (Acer pseudoplatanus). By mapping the enzymatic reaction products within the Golgi apparatus, the fucosyl‐ and xylosyltransferase subcellular localization was made possible using immunocytochemistry on thin sections of high‐pressure frozen and freeze‐substituted sycamore cells. This procedure allows a much better preservation of organelles, and particularly of the Golgi stack morphology, than that obtained with conventionally fixed samples. Glycoproteins containing β→2 xylose and α1→3 fucose residues were immunodetected in the cell wall, the vacuole, and the Golgi cisternae. The extent of immunolabeling over the different cisternae of 50 Golgi stacks was quantified after treatment with anti‐xylose or anti‐fucose antibodies. Labeling for xylose‐containing glycoproteins was predominent in the medial cisternae, while fucose‐containing glycoproteins were mainly detected in the trans compartment. Therefore, in plants, complex N‐linked glycan xylosylation probably occurs mostly at the medial Golgi level and α1→3 fucose is mainly incorporated in the trans cisternae. Finally, fucose‐ and xylose‐containing glycoproteins were also immunolocalized, albeit to a lesser extent, in earlier Golgi compartments. This indicates that the glycosylation events are a continuous process with some maxima in given compartments, rather than a succession of discrete and compartment‐dependent steps.
Analysis of clones carrying repeated DNA sequences in two YAC libraries of Arabidopsis thaliana DNA
Authors: Schmidt Renate , Putterill Joanna , West Joanne , Cnops Gerda , Robson Frances , Coupland George , Dean Caroline
Published: November 2004

YAC clones carrying repeated DNA sequences from the Arabidopsis thaliana genome have been characterized in two widely used Arabidopsis YAC libraries, the EG library and the EW library. Ribosomal, chloroplast and the paracentromeric repeat sequences are differentially represented in the two libraries. The coordinates of YAC clones hybridizing to these sequences are given. A high proportion of EG YAC clones were classified as containing chimaeric inserts because individual clones carried unique sequences and repetitive sequences originating from different locations in the genome. None of the EW YAC clones analysed were chimaeric in this way. YAC clones carrying tandemly repeated sequences, such as the paracentromeric or rDNA sequences, exhibited a high degree of instability. These observations need to be taken into account when using these libraries in the development of a physical map of the Arabidopsis genome and in chromosome walking experiments.
Disabled and successful: education in the life stories of disabled high achievers
Authors: Shah Sonali , Travers Cheryl , Arnold John
Published: November 2004

There has been much debate concerning the pros and cons of special and mainstream education for young people with a disability. This paper adds data to this debate by reporting the educational experiences of 20 high‐achievers with congenital disabilities who live in the United Kingdom and were born between 1950 and 1970. It presents personal accounts of the high‐achievers’ perceptions of how their education, which was either purely in special schools, in mainstream schools or a combination of both, had influenced their transition to adulthood. While those who attended special school considered it to provide a supportive environment that permitted the cultivation of their personalities without the constraints of non‐disabled barriers, many others thought it prevented them as disabled children from interacting with non‐disabled peers, thus inhibiting social integration between the disabled and non‐disabled world. This was the main perceived advantage of mainstream education although problems of physical access meant that some choices were out of reach. The findings highlight how both special and mainstream education can be compatible with career success of individual disabled people. The paper implies that a combination of the two systems may be needed to facilitate disabled students to develop psychologically, socially and cognitively at the rate of their non‐disabled peers, and proposes that link schools and partial integration could contribute to the achievement of such goals.
Chemotherapy‐induced cell death in primary cerebellar granule neurons but not in astrocytes: in vitro paradigm of differential neurotoxicity
Authors: Wick Antje , Wick Wolfgang , Hirrlinger Johannes , Gerhardt Ellen , Dringen Ralf , Dichgans Johannes , Weller Michael , B. Schulz Jörg
Published: November 2004

The nervous system is frequently the site of symptomatic toxicity of antineoplastic agents. However, there is limited information about the differential vulnerability of neurons, astrocytes and glioma cells. We have analyzed the effects of four chemotherapeutic drugs (lomustine, cisplatin, topotecan and vincristine) on primary cerebellar granule neurons and astrocytes derived from rats. All drugs led to cell death in cerebellar granule neurons in a concentration‐dependent manner. Comparison of the EC50 values for cerebellar neurons and astrocytes with the median EC50 values of 12 malignant glioma cell lines demonstrated a large therapeutic range for lomustin and cisplatin. Further, this comparison revealed a 100‐fold higher sensitivity of cerebellar neurons towards vincristine and 10‐fold higher sensitivity towards topotecan compared with glioma cells. Astrocytes were generally resistant to vincristine. In cerebellar granule neurons, vincristine and to a lesser extent topotecan induced caspase 3 and caspase 9 cleavage, and enhanced caspase activity and Akt‐dependent expression of phosphorylated BAD. zVAD‐fmk, a caspase inhibitor and brain‐derived neurotrophic factor (BDNF), but not MK‐801, a non‐competitive NMDA receptor antagonist, significantly reduced vincristine‐ or topotecan‐induced cell death.
Tyramine receptor (SER‐2) isoforms are involved in the regulation of pharyngeal pumping and foraging behavior in Caenorhabditis elegans
Authors: Rex Elizabeth , Molitor Scott C. , Hapiak Vera , Xiao Hong , Henderson Megan , Komuniecki Richard
Published: November 2004

Octopamine regulates essential processes in nematodes; however, little is known about the physiological role of its precursor, tyramine. In the present study, we have characterized alternatively spliced Caenorhabditis elegans tyramine receptor isoforms (SER‐2 and SER‐2A) that differ by 23 amino acids within the mid‐region of the third intracellular loop. Membranes prepared from cells expressing either SER‐2 or SER‐2A bind [3H]lysergic acid diethylamide (LSD) in the low nanomolar range and exhibit highest affinity for tyramine. Similarly, both isoforms exhibit nearly identical Ki values for a number of antagonists. In contrast, SER‐2A exhibits a significantly lower affinity than SER‐2 for other physiologically relevant biogenic amines, including octopamine. Pertussis toxin treatment reduces affinity for both tyramine and octopamine, especially for octopamine in membranes from cells expressing SER‐2, suggesting that the conformation of the mid‐region of the third intracellular loop is dictated by G‐protein interactions and is responsible for the differential tyramine/octopamine affinities of the two isoforms. Tyramine reduces forskolin‐stimulated cAMP levels in HEK293 cells expressing either isoform with nearly identical IC50 values. Tyramine, but not octopamine, also elevates Ca2+ levels in cells expressing SER‐2 and to a lesser extent SER‐2A. Most importantly, ser‐2 null mutants (pk1357) fail to suppress head movements while reversing in response to nose‐touch, suggesting a role for SER‐2 in the regulation of foraging behavior, and fail to respond to tyramine in assays measuring serotonin‐dependent pharyngeal pumping. These are the first reported functions for SER‐2. These results suggest that C. elegans contains tyramine receptors, that individual SER‐2 isoforms may differ significantly in their sensitivity to other physiologically relevant biogenic amines, such as octopamine (OA), and that tyraminergic signaling may be important in the regulation of key processes in nematodes.
Low nNOS protein in the locus coeruleus in major depression
Authors: Karolewicz B. , Szebeni K. , Stockmeier C. A. , Konick L. , Overholser J. C. , Jurjus G. , Roth B. L. , Ordway G. A.
Published: November 2004

Disruptions of glutamatergic and noradrenergic signaling have been postulated to occur in depressive disorders. Glutamate provides excitatory input to the noradrenergic locus coeruleus (LC). In this study, the location of immunoreactivity against neuronal nitric oxide synthase (nNOS), an intracellular mediator of glutamate receptor activation, was examined in the normal human LC, and potential changes in nNOS immunoreactivity that might occur in major depression were evaluated. Tissue containing LC, and a non‐limbic, LC projection area (cerebellum) was obtained from 11 to 12 matched pairs of subjects with major depression and control subjects lacking major psychiatric diagnoses. In the LC region, nNOS immunoreactivity was found in large neuromelanin‐containing neurons, small neurons lacking neuromelanin, and glial cells. Levels of nNOS immunoreactivity were significantly lower in the LC (− 44%, p < 0.05), but not in the cerebellum, when comparing depressed with control subjects. nNOS levels were positively correlated with brain pH values in depressed, but not control, subjects in both brain regions. Low levels of nNOS in the LC may reflect altered excitatory input to this nucleus in major depression. However, pH appears to effect preservation of nNOS immunoreactivity in subjects with depression. This factor may contribute, in part, to low levels of nNOS in depression.
Curcumin, the active constituent of turmeric, inhibits amyloid peptide‐induced cytochemokine gene expression and CCR5‐mediated chemotaxis of THP‐1 monocytes by modulating early growth response‐1 transcription factor
Authors: Giri Ranjit K. , Rajagopal Vikram , Kalra Vijay K.
Published: November 2004

Epidemiological studies show reduced risk of Alzheimer's disease (AD) among patients using non‐steroidal inflammatory drugs (NSAID) indicating the role of inflammation in AD. Studies have shown a chronic CNS inflammatory response associated with increased accumulation of amyloid peptide and activated microglia in AD. Our previous studies showed that interaction of Aβ1−40 or fibrilar Aβ1−42 caused activation of nuclear transcription factor, early growth response‐1 (Egr‐1), which resulted in increased expression of cytokines (TNF‐α and IL‐1β) and chemokines (MIP‐1β, MCP‐1 and IL‐8) in monocytes. We determined whether curcumin, a natural product known to have anti‐inflammatory properties, suppressed Egr‐1 activation and concomitant expression of cytochemokines. We show that curcumin (12.5–25 µm) suppresses the activation of Egr‐1 DNA‐binding activity in THP‐1 monocytic cells. Curcumin abrogated Aβ1−40‐induced expression of cytokines (TNF‐α and IL‐1β) and chemokines (MIP‐1β, MCP‐1 and IL‐8) in both peripheral blood monocytes and THP‐1 cells. We found that curcumin inhibited Aβ1−40‐induced MAP kinase activation and the phosphorylation of ERK‐1/2 and its downstream target Elk‐1. We observed that curcumin inhibited Aβ1−40‐induced expression of CCR5 but not of CCR2b in THP‐1 cells. This involved abrogation of Egr‐1 DNA binding in the promoter of CCR5 by curcumin as determined by: (i) electrophoretic mobility shift assay, (ii) transfection studies with truncated CCR5 gene promoter constructs, and (iii) chromatin immunoprecipitation analysis. Finally, curcumin inhibited chemotaxis of THP‐1 monocytes in response to chemoattractant. The inhibition of Egr‐1 by curcumin may represent a potential therapeutic approach to ameliorate the inflammation and progression of AD.
Functional characterization of mouse α4β2 nicotinic acetylcholine receptors stably expressed in HEK293T cells
Authors: Karadsheh Mark S. , Shah M. Salman , Tang Xin , Macdonald Robert L. , Stitzel Jerry A.
Published: November 2004

Mouse α4β2 nicotinic acetylcholine receptors (nAchRs) were stably expressed in HEK293T cells. The function of this stable cell line, termed mmα4β2, was assessed using an aequorin‐based luminescence method that measures agonist‐evoked changes in intracellular calcium. Agonist‐elicited changes in intracellular calcium were due primarily to direct entry of calcium through the α4β2 channel, although release of calcium from intracellular stores contributed ˜ 28% of the agonist‐evoked response. Agonist pharmacologies were very similar between the mmα4β2 cells and most cell lines that stably express human α4β2 nAchRs. Based on agonist profiles and sensitivity to the antagonist dihydro‐β‐erythroidine (DHβE), the predominant α4β2 nAchR expressed in the mmα4β2 cells exhibits a pharmacology that most resembles the DHβE‐sensitive component of 86Rb+ efflux from mouse brain synaptosomes. However, when evaluated with the aequorin assay, the mmα4β2 nAchR was found to be atypically sensitive to blockade by the presumed α7‐selective antagonist methyllycaconitine (MLA), exhibiting an IC50 value of 31 ± 0.1 nm. Similar IC50 values have been reported for the MLA inhibition of nicotine‐stimulated dopamine release, a response that is mediated by β2‐subunit‐containing nAchRs and not α7‐subunit‐containing nAchRs. Consequently, at low nanomolar concentrations, MLA may not be as selective for α7‐containing nAchRs as previously thought.
Proteasome inhibition increases DNA and RNA oxidation in astrocyte and neuron cultures
Authors: Ding Qunxing , Dimayuga Edgardo , Markesbery William R. , Keller Jeffrey N.
Published: November 2004

Increased levels of nucleic acid oxidation have been described as part of normal brain aging and have been demonstrated to occur in multiple neurological disorders. The basis for increased nucleic acid oxidation in each of these conditions is presently unknown. Proteasome inhibition occurs in a host of neurodegenerative conditions and likely contributes to increased levels of oxidative damage and neurotoxicity. In the present study we demonstrate for the first time the ability of proteasome inhibition to increase the level of nucleic acid oxidation in primary neuron and astrocyte cultures. Administration of proteasome inhibitors (MG262, MG115) at concentrations that do not induce neuron death in the first 24 h of treatment, dramatically increase the levels of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) and 8‐hydroxyguanosine (8OHG) immunoreactivity in both cell types. Neurons underwent larger increases in nucleic acid oxidation compared to astrocyte cultures. While both DNA and RNA oxidation were observed following proteasome inhibition, RNA appeared to undergo a greater degree of oxidation than DNA. Both 18S and 28S ribosomal RNA were dramatically decreased following proteasome inhibition. Interestingly, an accumulation of unprocessed and/or cross‐linked RNA species was observed following proteasome inhibition. Taken together, these data indicate the ability of proteasome inhibition to increase the levels of nucleic acid oxidation in both neurons and astrocytes, and suggest that proteasome inhibition may have deleterious effects on transcription and translation in both neurons and glia.
Pathophysiological concentrations of amyloid β proteins directly inhibit rat brain and recombinant human type II phosphatidylinositol 4‐kinase activity
Authors: Wu Bo , Kitagawa Kaori , Zhang Nan‐Yan , Liu Bing , Inagaki Chiyoko
Published: November 2004

We previously found that pathophysiological concentrations (≤ 10 nm) of an amyloid β protein (Aβ25–35) reduced the plasma membrane phosphatidylinositol monophosphate level in cultured rat hippocampal neurons with a decrease in phosphatidylinositol 4‐monophosphate‐dependent Cl–‐ATPase activity. As this suggested an inhibitory effect of Aβ25–35 on plasma membrane phosphatidylinositol 4‐kinase (PI4K) activity, in vitro effects of Aβs on PI4K activity was examined using rat brain subcellular fractions and recombinant human type II PI4K (PI4KII). Aβ25–35 (10 nm) inhibited PI4KII activity, but neither PI 3‐kinase (PI3K) nor type III PI4K (PI4KIII) activity, in microsomal fractions, while 100 nm Aβ25–35 inhibited PI3K activity in mitochondrial fractions. In plasma membrane‐rich fractions, Aβs (> 0.5 nm) dose‐dependently inhibited PI4KII activity, the maximal inhibition to 77–87% of control being reached around 10 nm of Aβs without significant changes in apparent Km values for ATP and PI, suggesting non‐competitive inhibition by Aβs. The inhibition by 10 nm Aβ25–35 was reversible. In recombinant human PI4KIIα, inhibition profiles of Aβs were similar to those in rat brain plasma membranes. Therefore, pathophysiological concentrations of Aβs directly and reversibly inhibited plasma membrane PI4KII activity, suggesting that plasma membrane PI4KII is a target of Aβs in the pathogenesis of Alzheimer's disease.
Application of magnetically isolated rat retinal vascular endothelial cells for the determination of transporter gene expression levels at the inner blood–retinal barrier
Authors: Tomi Masatoshi , Hosoya Ken‐ichi
Published: November 2004

The purpose of the present study was to quantify transporter gene levels at the inner blood–retinal barrier (inner BRB) using a combination of magnetic isolation method for rat retinal vascular endothelial cells (RVEC) and real‐time quantitative PCR analysis. The transcript levels of CD31, Tie‐2, claudin‐5, occludin, Jam‐1, mdr1a, oatp2, and oatp14 in the RVEC fraction were more than 100‐fold greater than those in the non‐RVEC fraction, suggesting that these genes are predominantly expressed at the inner BRB. The transcript levels of GLUT1 and MCT1 in the RVEC fraction were the most abundant in the respective transporter family, suggesting that GLUT1 and MCT1 play a predominant role in d‐glucose and monocarboxylate transport, respectively, at the inner BRB. In conclusion, application of magnetically isolated RVEC is able to determine transporter gene levels at the inner BRB thereby increasing our understanding of inner BRB functions at a molecular level.
Prospective Association Between Low and High Total and Low‐Density Lipoprotein Cholesterol and Coronary Heart Disease in Elderly Men
Authors: Curb J. David , Abbott Robert D. , Rodriguez Beatriz L. , Masaki Kamal , Popper Jordan , Chen Randi , Petrovitch Helen , Blanchette Patricia , Schatz Irwin , Yano Katsuhiko
Published: November 2004

Objectives:To examine the relationship between total cholesterol (TC) and low‐density lipoprotein cholesterol (LDL‐C) and the incidence of coronary heart disease (CHD) in elderly men.

Design:Prospective.

Setting:Population based.

Participants:A sample of 2,424, Japanese‐American men aged 71 to 93 was used.

Measurements:Six years of data on incident fatal plus nonfatal CHD were examined.

Results:Analysis revealed a significant U‐shaped relationship between age‐adjusted CHD rates and both TC and LDL‐C. The ranges of TC and LDL‐C with the lowest risk of CHD were 200 to 219 mg/dL and 120 to 139 mg/dL, respectively. As cholesterol concentrations declined and increased beyond these ranges, the risk of CHD increased. These U‐shaped relationships remained significant after adjusting for age and other risk factors.

Conclusion:The U‐shaped associations between TC and LDL‐C and CHD imply a complex relationship between lipids and CHD in late life. The results indicate that elevated lipid levels should continue to be treated in healthy elderly individuals, as they are in those who are younger, although pharmacologically lowering lipids to excessively low levels in the elderly may warrant further study, as does the contribution of subclinical frailty to the relationship of lipids to CHD risk.
Vision Impairment and Combined Vision and Hearing Impairment Predict Cognitive and Functional Decline in Older Women
Authors: Lin Michael Y. , Gutierrez Peter R. , Stone Katie L. , Yaffe Kristine , Ensrud Kristine E. , Fink Howard A. , Sarkisian Catherine A. , Coleman Anne L. , Mangione Carol M.
Published: November 2004

Objectives: To determine the association between vision and hearing impairment and subsequent cognitive and functional decline in community‐residing older women.

Design: Prospective cohort study.

Setting: Four metropolitan areas of the United States.

Participants: A total of 6,112 women aged 69 and older participating in the Study of Osteoporotic Fractures (SOF) between 1992 and 1994.

Measurements: Five thousand three hundred forty‐five participants had hearing measured, 1,668 had visual acuity measured, and 1,636 had both measured. Visual impairment was defined as corrected vision worse than 20/40. Hearing impairment was defined as the inability to hear a tone of 40 dB or greater at 2,000 hertz. Participants completed the modified Mini‐Mental State Examination and/or a functional status assessment at baseline and follow‐up. Cognitive and functional decline were defined as the amount of decline from baseline to follow‐up that exceeded the observed average change in scores by at least 1 standard deviation.

Results: About one‐sixth (15.7%) of the sample had cognitive decline; 10.1% had functional decline. In multivariate models adjusted for sociodemographic characteristics and chronic conditions, vision impairment at baseline was associated with cognitive (odds ratio (OR)=1.78, 95% confidence interval (CI)=1.21–2.61) and functional (OR=1.79, 95% CI=1.15–2.79) decline. Hearing impairment was not associated with cognitive or functional decline. Combined impairment was associated with the greatest odds for cognitive (OR=2.19, 95% CI=1.26–3.81) and functional (OR=1.87, 95% CI=1.01–3.47) decline.

Conclusion: Sensory impairment is associated with cognitive and functional decline in older women. Studies are needed to determine whether treatment of vision and hearing impairment can decrease the risk for cognitive and functional decline.
Low Testosterone Is Associated with Decreased Function and Increased Mortality Risk: A Preliminary Study of Men in a Geriatric Rehabilitation Unit
Authors: Shores Molly M. , Moceri Victoria M. , Gruenewald David A. , Brodkin Kayla I. , Matsumoto Alvin M. , Kivlahan Daniel R.
Published: November 2004

Objectives: To evaluate whether low testosterone levels are associated with greater depression or poorer function in a geriatric rehabilitation unit.

Design: Retrospective review.

Setting: Geriatric rehabilitation unit.

Measurements: Low testosterone levels were defined as total testosterone of 3.0 ng/mL or less or free testosterone of 9.0 pg/mL or less. Age, ethnicity, weight, depression, ambulation, length of rehabilitation, and 6‐month rehospitalization and mortality rates were obtained. Overall illness severity was determined using the Cumulative Illness Rating Scale for Geriatrics.

Results: Low testosterone levels were present in 29 of 44 (65.9%) men. There were no significant differences between men with low and normal testosterone levels in ethnicity, age, weight, depression, and overall illness severity. Lower testosterone levels were correlated with decreased ability to ambulate and transfer (Spearman P>.34; P<.05). There were no significant differences between men with low and normal testosterone in length of stay on the rehabilitation unit (mean±standard deviation= 19.6±11.6 vs 17.7±17.5 days, P=.68) or rehospitalization rates (41.4% vs 26.7%; P=.34). Men with low testosterone had a trend toward increased 6‐month mortality (31.0% vs 6.7%; χ2=3.3, P=.07) and shorter survival time (log rank=3.2; df 1, P=.07). After entering testosterone and variables with potential prognostic significance for mortality in a stepwise manner in a Cox regression analysis, there was a significant mortality risk associated with low testosterone (hazard ratio=27.9, 95% confidence interval=2.0–384.0; P=.01).

Conclusion: Low testosterone levels were correlated with decreased physical function and increased risk for 6‐month mortality. Prospective studies with larger sample sizes and better standardized testosterone measures are needed to confirm these findings.
Emergence and Transmission of Amantadine‐Resistant Influenza A in a Nursing Home
Authors: Schilling Margo , Gravenstein Stefan , Drinka Paul , Cox Nancy , Krause Peggy , Povinelli Laura , Shult Peter
Published: November 2004

Objectives: To prospectively detect amantadine‐resistant influenza when amantadine was used for influenza A outbreak control.

Design: Prospective clinical surveillance and viral culture of all new respiratory illnesses during the course of amantadine prophylaxis.

Setting: A 721‐bed, 14‐ward nursing home for veterans and spouses during an influenza A outbreak (1993–94).

Participants: Residents of a veterans hospital and their spouses.

Measurements: Nasopharyngeal and throat viral culture. All residents with positive cultures who developed new respiratory symptoms while receiving or residing on a unit receiving amantadine prophylaxis had antiviral‐resistance testing and polymerase chain reaction restriction analyses performed.

Results: Amantadine prophylaxis was administered sequentially on nine of 14 wards to all well residents for 14 to 31 days/ward to control influenza outbreaks between December 9, 1993, and January 28, 1994. Amantadine treatment was simultaneously provided to 29 ill residents. Between December 3, 1993, and January 22, 1994, 68 culture‐positive cases of influenza A were detected. Twenty subjects were receiving or residing on units receiving amantadine prophylaxis. Amantadine sensitivity testing could be performed on 16 residents; 12 residents had amantadine resistant strains. Four of the 12 had not received any antiviral treatment. Illness onset ranged from 1 to 22 days after amantadine prophylaxis was begun on the individual's unit. Two ribonucleic acid (RNA) mutations in the gene coding the M2 protein transmembrane region were observed that were clustered in time and space. Isolates from two roommates, one receiving amantadine for 18 days and one on no antiviral, had identical RNA sequences.

Conclusion: Antiviral resistance may be responsible for failure of prophylaxis in nursing home outbreaks. Strategies that use different classes of antivirals for prophylaxis and treatment may limit emergence and transmission of resistant virus.
Subjective Memory Deterioration and Future Dementia in People Aged 65 and Older
Authors: Wang Li , Van Belle Gerald , Crane Paul K. , Kukull Walter A. , Bowen James D. , McCormick Wayne C. , Larson Eric B.
Published: November 2004

Objectives: To study whether subjective memory deterioration is associated with future dementia in older people.

Design: A population‐based prospective cohort study begun in 1994 with biennial follow‐up interviews.

Setting: Community‐based members of Group Health Cooperative, a large health maintenance organization in the Seattle area.

Participants: A sample of 1,883 subjects, dementia free, aged 65 and older, who scored 91 or higher on the 100‐point Cognitive Ability Screening Instrument (CASI) at study entry.

Measurements: Subjective memory was assessed by asking whether memory had changed on 5‐point Likert scales (e.g., 1=definitely improved, 3=no change, 5=definitely deteriorated) with regard to five items: remembering names, faces, friends, and appointments and judging the time. The items were summed for a possible total score ranging from 5 to 25. Subjective memory deterioration was defined as present if the total score was 20 or above. Cognitive performance was measured using the CASI. Incident dementia cases were identified using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria.

Results: Of 1,883 subjects, 126 developed dementia during 5 years of follow‐up. Subjective memory deterioration was associated with cognitive decline and incident dementia. Age modified the association between subjective memory deterioration and future dementia. For persons reporting subjective memory deterioration at the ages of 70, 75, and 80, the hazard ratios of developing dementia were 6.0 (95% confidence interval (CI)=2.1–18), 3.2 (95% CI=1.6–6.2) and 1.6 (95% CI=0.86–3.1), respectively.

Conclusion: Subjective memory deterioration was found to precede the development of dementia in older people with normal cognitive screening results. These findings suggest that a high level of subjective memory deterioration in persons with normal objective cognitive function may identify a subset of individuals at greater risk for developing dementia.
Incidence of Loss of Ability to Walk 400 Meters in a Functionally Limited Older Population
Authors: Chang Milan , Cohen‐Mansfield Jiska , Ferrucci Luigi , Leveille Suzanne , Volpato Stefano , De Rekeneire Nathalie , Guralnik Jack M.
Published: November 2004

Objectives: To assess the incidence of and factors related to nondisabled but functionally limited older adults aged 75 to 85 years losing the ability to walk 400 m.

Design: Observational study with average follow‐up of 21 months.

Setting: Community.

Participants: At baseline, 101 persons with objective signs of functional limitations and intact cognitive function agreed to participate in the study. Of these, 81 were able to walk 400 m at baseline, and 62 participated in the follow‐up examination.

Measurements: Mobility disability was defined as an inability to complete a 400‐m walk test. At baseline, eligible participants (n=81) had the ability to walk 400 m, scored between 4 and 9 on the Short Physical Performance Battery (SPPB; range 0–12), and scored 18 or more on the Mini‐Mental State Examination. Demographics, difficulty in daily activities, disease status, behavioral risk factors, and muscle strength were assessed at baseline and follow‐up.

Results: Of 62 persons at follow‐up, 21 (33.9%) developed incident mobility disability. The strongest predictors of loss of mobility were the time to complete the 400‐m walk at baseline (odds ratio (OR)=1.6 per 1‐minute difference, 95% confidence interval (CI)=1.04–2.45), and decline in SPPB score over the follow‐up (OR=1.4 per 1‐point difference, 95% CI=1.01–1.92).

Conclusion: Older persons with functional limitations have a high rate of loss of ability to walk 400 m. The 400‐m walk test is a highly relevant, discrete outcome that is an ideal target for testing preventive interventions in vulnerable older populations.
SOURCES AND MAGNITUDE OF VARIATION OF ECHOCARDIOGRAPHIC MEASUREMENTS IN NORMAL STANDARDBRED HORSES
Authors: Buhl Rikke , Ersbøll Annette Kjær , Eriksen Lis , Koch Jørgen
Published: November 2004

The purpose of this study was to assess the intraobserver variation of various echocardiographic measures in standardbred trotters. Serial echocardiographic examinations were carried out on eight standardbred mares by one ultrasonographer for 5 separate days. During each examination, five nonconsecutive cardiac cycles (frames) were recorded and an average obtained for each individual measure. Various echocardiographic measures were obtained by use of two‐dimensional (2‐D), M‐mode, color flow Doppler and pulsed wave Doppler echocardiography. The total variation in the echocardiographic measurements was split into three levels: the variation between horses, the day‐to‐day variation within individual horses, and finally the variation within horse on the same day of examination (intercardiac cycle variation). The intraclass correlation coefficient (ICC) was calculated for each measure. The ICC represents the variability of the measurements because of differences between the horses. In general the 2‐D, M‐mode and color flow Doppler measures had higher ICC values (ICC from 0.63 to 0.95) than the pulsed wave Doppler measures (ICC from 0.24 to 0.46), and the former measures were more repeatable than the pulsed wave measures. Exceptions to that were left ventricular free wall in diastole, the pulmonary artery in systole and the left ventricular mass, which all had low repeatability (ICC from 0.22 to 0.49). The results were used to calculate the relative differences that must be detected to diagnose a statistically significant change between two measurements in an individual horse. Differences from 4.2% to 21.8% must be achieved to document significant changes between serial measurements. A general tendency is that the color flow and pulsed wave Doppler measures require a larger relative difference (11.4–21.8%) between the measures to point out statistically significant cardiac changes than the 2‐D and M‐mode measures (4.2–13.9%).
MOTION‐CORRECTION TECHNIQUES FOR STANDING EQUINE MRI
Authors: McKnight Alexia L. , Manduca Armando , Felmlee Joel P. , Rossman Philip J. , McGee Kiaran P. , Ehman Richard L.
Published: November 2004

Magnetic resonance imaging (MRI) of the distal extremities of the standing, sedated horse would be desirable if diagnostic quality images could be obtained. With the availability of extremity and special purpose magnet designs on the market, a system to safely accommodate the standing horse may gain increasing popularity. This paper considers the issue of motion that will need to be addressed to achieve successful, diagnostic quality images. The motion of the carpus and tarsus of five standing, sedated horses was quantified. The obtained motion records were then used to induce motion in cadaveric joint specimens during several MRI scans. The measured dorsal–palmar/plantar, medial–lateral, and proximal–distal random wobbling motions in the standing sedated horse were several centimeters in magnitude and generated severe motion‐artifacts during axial MRI of the cadaveric specimens. Two retrospective motion‐correction techniques (autocorrection and navigator‐based adaptive correction) were used to correct the corrupted images. The motion artifacts were nearly eliminated with the use of both techniques in series. Although significant hurdles remain, these results suggest promise for allowing diagnostic quality MRI of the carpus and tarsus in the standing horse.
RADIOGRAPHIC AND PATHOLOGIC CHARACTERIZATION OF LATERAL PALMAR INTERCARPAL LIGAMENT AVULSION FRACTURES IN THE HORSE
Authors: Beinlich Christopher P. , Nixon Alan J.
Published: November 2004

In this study, the radiographic and histologic appearance of lateral palmar intercarpal ligament (LPICL) avulsion in the horse was characterized. Thirty‐seven horses with radiographic evidence of avulsion fragments originating from the medial palmar aspect of the ulnar carpal bone were examined. The dorsolateral to palmaromedial projection was useful for evaluating the size and shape of the avulsed bone fragment, and the dorsopalmar projection added information on the relative proximity of the fragment to its fracture bed. Radiographic features that differentiated LPICL avulsion from subchondral cystic lesions of the ulnar carpal bone included a variable‐sized osseous opacity adjacent to the lucent concavity of the fracture bed and the consistent location within the palmar transition zone at the confluence of LPICL insertion and hyaline cartilage on the palmar surface of the ulnar carpal bone. All 26 horses having surgical removal of the fragments had arthroscopic confirmation that the fragment was within the LPICL. Histologic examination confirmed the fragments were fracture related rather than developmental or the result of dystrophic mineralization. Many of the fragments had attached remnants of a ligament. This study describes the radiographic, surgical, and histologic features in 37 horses which better characterize LPICL avulsion fracture in the carpus and provide differentiating features to assist in separating this syndrome from true osseous cyst‐like lesions within the ulnar carpal bone.
ULTRASONOGRAPHIC DIAGNOSIS—SMALL BOWEL LYMPHANGIECTASIA IN A DOG
Authors: Louvet Arnaud , Denis Bruno
Published: November 2004

A 7‐year‐old, West Highland White Terrier had a 5‐month history of diarrhea, dysorexia, and weight loss. Sonographically, there was a focal area of intestinal thickening with loss of layering. A neoplastic or severe inflammatory condition was suspected and intestinal lymphangiectasia was diagnosed histopathologically. This patient seems to be the first description of intestinal lymphangiectasia appearing as an intestinal mass.
USE OF RADIATION AND A SLOW‐RELEASE CISPLATIN FORMULATION FOR TREATMENT OF CANINE NASAL TUMORS
Authors: Lana Susan E. , Dernell William S. , Lafferty Mary H. , Withrow Stephen J. , LaRue Susan M.
Published: November 2004

The purpose of this study was to evaluate the combined use of radiation and a slow‐release cisplatin chemotherapy formulation for treatment of malignant nasal tumors in dogs. In this retrospective analysis, 51 dogs were evaluated with respect to treatment toxicity, tumor type, stage of disease, cribriform plate involvement, and overall survival. In general, treatment was well tolerated. Mean and median survival as assessed by the Kaplan–Meier product limit method was 570 and 474 days, respectively. No other factors, including tumor type, stage of disease, or cribriform plate invasion had a significant impact on survival. In conclusion, a combination of slow release cisplatin chemotherapy and radiation for the treatment of canine nasal tumors is well tolerated. Results of this analysis warrant further study to elucidate possible other beneficial radiation potentiating drugs and dosing schedules.
Effect of Mean Stress on the Damage of Wind Turbine Blades
Authors: Sutherland Herbert J. , Mandell John F.
Published: November 2004

In many analyses of composite wind turbine blades, the effects of mean stress on the determination of damage are either ignored completely or they are characterized inadequately. An updated Goodman diagram for the fiberglass materials that are typically used in wind turbine blades has been released recently. This diagram, which is based on the MSU/DOE Fatigue Database, contains detailed information at thirteen R-values. This diagram is the most detailed to date, and it includes several loading conditions that have been poorly represented in earlier studies. This formulation allows the effects of mean stress on damage calculations to be evaluated. The evaluation presented here uses four formulations for the S-N behavior of the fiberglass. In the first analysis, the S-N curve for the composite is assumed to be independent of mean stress and to have a constant slope. The second is a linear Goodman diagram, the third is a bi-linear Goodman diagram and the fourth is the full Goodman diagram. Two sets of load spectra, obtained by the LIST (Long term Inflow and Structural Test) program, are used for this evaluation. The results of the analyses, equivalent fatigue loads and damage predictions, are compared to one another. These results illustrate a significant overestimation of the equivalent fatigue loads when the mean stress is not considered in the calculation. And, the results from the updated Goodman diagram illustrate that there are significant differences in accumulated damage when the Goodman diagram includes information on the transition between compressive and tensile failure modes.
A Comparison of Standard Coherence Models for Inflow Turbulence With Estimates from Field Measurements
Authors: Saranyasoontorn Korn , Manuel Lance , Veers Paul S.
Published: November 2004

The Long-term Inflow and Structural Test (LIST) program, managed by Sandia National Laboratories, Albuquerque, NM, is gathering inflow and structural response data on a modified version of the Micon 65/13 wind turbine at a site near Bushland, Texas. With the objective of establishing correlations between structural response and inflow, previous studies have employed regression and other dependency analyses to attempt to relate loads to various inflow parameters. With these inflow parameters that may be thought of as single-point-in-space statistics that ignore the spatial nature of the inflow, no significant correlation was identified between load levels and any single inflow parameter or even any set of such parameters, beyond the mean and standard deviation of the hub-height horizontal wind speed. Accordingly, here, we examine spatial statistics in the measured inflow of the LIST turbine by estimating the coherence for the three turbulence components (along-wind, across-wind, and vertical). We examine coherence spectra for both lateral and vertical separations and use the available ten-minute time series of the three components at several locations. The data obtained from spatial arrays on three main towers located upwind from the test turbine as well as on two additional towers on either side of the main towers consist of 291 ten-minute records. Details regarding estimation of the coherence functions from limited data are discussed. Comparisons with standard coherence models available in the literature and provided in the International Electrotechnical Commission (IEC) guidelines are also discussed. It is found that the Davenport exponential coherence model may not be appropriate especially for modeling the coherence of the vertical turbulence component since it fails to account for reductions in coherence at low frequencies and over large separations. Results also show that the Mann uniform shear turbulence model predicts coherence spectra for all turbulence components and for different lateral separations better than the isotropic von Ka´rma´n model. Finally, on studying the cross-coherence among pairs of turbulence components based on field data, it is found that the coherence observed between along-wind and vertical turbulence components is not predicted by the isotropic von Ka´rma´n model while the Mann model appears to overestimate this cross-coherence.
Regulated Fast Nucleocytoplasmic Shuttling Observed by Reversible Protein Highlighting
Authors: Ando Ryoko , Mizuno Hideaki , Miyawaki Atsushi
Published: November 2004

The observation of the regulation of fast protein dynamics in a cellular context requires the development of reliable technologies. Here, a signal regulation cascade reliant on the stimulus-dependent acceleration of the bidirectional flow of mitogen-activated protein kinase (extracellular signal-regulated kinase) across the nuclear envelope was visualized by reversible protein highlighting. Light-induced conversion between the bright and dark states of a monomeric fluorescent protein engineered from a novel coral protein was employed. Because of its photochromic properties, the protein could be highlighted, erased, and highlighted again in a nondestructive manner, allowing direct observation of regulated fast nucleocytoplasmic shuttling of key signaling molecules.
The Ocean Takes a Deep Breath
Authors: Körtzinger Arne , Schimanski Jens , Send Uwe , Wallace Douglas
Published: November 2004

Deep convection is the major mechanism for replenishing oxygen in the deep interior of the world ocean, and its variability affects the use of atmospheric oxygen to monitor the global carbon cycle. Sensors mounted on autonomous floats allow this episodic breathing of the ocean to be monitored in near real time. The results suggest that the tools are available now to make oxygen a key parameter in marine global change research.
A Protein Sensor for siRNA Asymmetry
Authors: Tomari Yukihide , Matranga Christian , Haley Benjamin , Martinez Natalia , Zamore Phillip D.
Published: November 2004

To act as guides in the RNA interference (RNAi) pathway, small interfering RNAs (siRNAs) must be unwound into their component strands, then assembled with proteins to form the RNA-induced silencing complex (RISC), which catalyzes target messenger RNA cleavage. Thermodynamic differences in the base-pairing stabilities of the 5′ ends of the two ∼21-nucleotide siRNA strands determine which siRNA strand is assembled into the RISC. We show that in
Drosophila
, the orientation of the Dicer-2/R2D2 protein heterodimer on the siRNA duplex determines which siRNA strand associates with the core RISC protein Argonaute 2. R2D2 binds the siRNA end with the greatest double-stranded character, thereby orienting the heterodimer on the siRNA duplex. Strong R2D2 binding requires a 5′-phosphate on the siRNA strand that is excluded from the RISC. Thus, R2D2 is both a protein sensor for siRNA thermodynamic asymmetry and a licensing factor for entry of authentic siRNAs into the RNAi pathway.