bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic cocaine exposure impairs progenitor proliferation but spares survival and maturation of neural precursors in adult rat dentate gyrus
Authors: Domínguez‐Escribà L. , Hernández‐Rabaza V. , Soriano‐Navarro M. , Barcia J. A. , Romero F. J. , García‐Verdugo J. M. , Canales J. J.
Published: July 2006

Recent observations indicate that drugs of abuse, including alcohol and opiates, impair adult neurogenesis in the hippocampus. We have studied in rats the impact of cocaine treatment (20 mg/kg, daily, i.p.) on cell proliferation, survival and maturation following short‐term (8‐day) and long‐term (24‐day) exposure. Using 5′‐bromo‐2‐deoxyuridine (BrdU) and Ki‐67 as mitotic markers at the end of the drug treatments, we found that both short‐ and long‐term cocaine exposures significantly reduced cell proliferation in the dentate gyrus (DG) of the hippocampus. By labelling mitotic cells with BrdU pulses before or during the early stages of the drug treatment, we determined that long‐term cocaine exposure did not affect the survival of newly generated cells. In register with this finding, cocaine chronic exposure did not increase the number of apoptotic cells labelled by TUNEL (terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labelling). Using doublecortin (DCX) immunocytochemistry and electron microscopy, we next examined the effects of cocaine exposure on the maturation of the neural precursors and on synaptic output to CA3. DCX immunocytochemistry showed that immature hippocampal cells of rats exposed to cocaine displayed normal arborization patterns and similar degrees of colocalization with BrdU at two different developmental stages. Moreover, cocaine did not produce significant morphological alterations of the mossy fibre projection system to stratum lucidum in the CA3 area of the hippocampus. The results presented demonstrate that chronic cocaine exposure impairs proliferation dynamics in the DG without significantly altering either the survival and growth of immature cells or the structural features of terminal projections to CA3.
Galanin–neuropeptide Y (NPY) interactions in central cardiovascular control: involvement of the NPY Y1 receptor subtype
Authors: Díaz‐Cabiale Zaida , Parrado Concepción , Rivera Alicia , De La Calle Adelaida , Agnati Luigi , Fuxe Kjell , Narváez José A.
Published: July 2006

The interactions between neuropeptide Y (NPY), specifically through NPY Y1 and Y2 receptor subtypes, and galanin [GAL(1–29)] have been analysed at the cardiovascular level. The cardiovascular effects of intracisternal coinjections of GAL(1–29) with NPY or NPY Y1 or Y2 agonists, as well as quantitative receptor autoradiography of the binding characteristics of NPY Y1 and Y2 receptor subtypes in the nucleus of the solitary tract (NTS), in the presence or absence of GAL(1–29), have been investigated. The effects of coinjections of GAL(1–29) and the NPY Y1 agonist on the expression of c‐FOS immunoreactivity in the NTS were also studied. The coinjection of NPY with GAL(1–29) induced a significant vasopressor and tachycardic action with a maximum 40% increase (P < 0.001). The coinjection of the NPY Y1 agonist and GAL(1–29) induced a similar increase in mean arterial pressure and heart rate as did NPY plus GAL(1–29), actions that were not observed with the NPY Y2 agonist plus GAL(1–29). GAL(1–29), 3 nm, significantly and substantially (by ∼ 40%) decreased NPY Y1 agonist binding in the NTS. This effect was significantly blocked (P < 0.01) in the presence of the specific galanin antagonist M35. The NPY Y2 agonist binding was not modified in the presence of GAL(1–29). At the c‐FOS level, the coinjection of NPY Y1 and GAL(1–29) significantly reduced the c‐FOS‐immunoreactive response induced by either of the two peptides. The present findings suggest the existence of a modulatory antagonistic effect of GAL(1–29) mediated via galanin receptors on the NPY Y1 receptor subtype and its signalling within the NTS.
Neonatal nicotine exposure impairs nicotinic enhancement of central auditory processing and auditory learning in adult rats
Authors: Liang Kevin , Poytress Bonnie Sue , Chen Yiling , Leslie Frances M. , Weinberger Norman M. , Metherate Raju
Published: July 2006

Children of women who smoke cigarettes during pregnancy display cognitive deficits in the auditory–verbal domain. Clinical studies have implicated developmental exposure to nicotine, the main psychoactive ingredient of tobacco, as a probable cause of subsequent auditory deficits. To test for a causal link, we have developed an animal model to determine how neonatal nicotine exposure affects adult auditory function. In adult control rats, nicotine administered systemically (0.7 mg/kg, s.c.) enhanced the sensitivity to sound of neural responses recorded in primary auditory cortex. The effect was strongest in cortical layers 3 and 4, where there is a dense concentration of nicotinic acetylcholine receptors (nAChRs) that has been hypothesized to regulate thalamocortical inputs. In support of the hypothesis, microinjection into layer 4 of the nonspecific nAChR antagonist mecamylamine (10 µm) strongly reduced sound‐evoked responses. In contrast to the effects of acute nicotine and mecamylamine in adult control animals, neither drug was as effective in adult animals that had been treated with 5 days of chronic nicotine exposure (CNE) shortly after birth. Neonatal CNE also impaired performance on an auditory‐cued active avoidance task, while having little effect on basic auditory or motor functions. Thus, neonatal CNE impairs nicotinic regulation of cortical function, and auditory learning, in the adult. Our results provide evidence that developmental nicotine exposure is responsible for auditory–cognitive deficits in the offspring of women who smoke during pregnancy, and suggest a potential underlying mechanism, namely diminished function of cortical nAChRs.
Partial depletion of dopamine in substantia nigra impairs motor performance without altering striatal dopamine neurotransmission
Authors: Andersson Daniel R. , Nissbrandt Hans , Bergquist Filip
Published: July 2006

Previous data indicate that the release of somatodendritic dopamine in substantia nigra influences motor activity and coordination, but the relative importance of somatodendritic dopamine release vs. terminal striatal dopamine release remains to be determined. We utilized simultaneous measurement of dopamine neurotransmission by microdialysis and motor performance assessment by rotarod test to investigate the effects of local dopamine depletion in rats. The vesicular monoamine transporter inhibitor tetrabenazine (100 µm) was administered locally in substantia nigra as well as in striatum. Nigral tetrabenazine administration decreased nigral dopamine dialysate concentrations to 7% of baseline and whole‐tissue dopamine content by 60%. Nigral dopamine depletion was associated with a reduction in motor performance to 73 ± 6% of pretreatment value, but did not alter dialysate dopamine concentrations in the ipsilateral striatum. Striatal tetrabenazine administration decreased striatal dopamine dialysate concentrations to 5% of baseline and doubled the somatodendritic dopamine response to motor activity, but it was not associated with changes in motor performance or dopamine content in striatal tissue. Simultaneous treatment of substantia nigra and striatum reduced motor performance to 58 ± 5% of the pretreatment value. The results of this study indicate that partial depletion of nigral dopamine stores can significantly impair motor functions, and that increased nigral dopamine release can counteract minor impairments of striatal dopamine transmission.
Glutamate enhances proliferation and neurogenesis in human neural progenitor cell cultures derived from the fetal cortex
Authors: Suzuki Masatoshi , Nelson Aaron D. , Eickstaedt Joshua B. , Wallace Kyle , Wright Lynda S. , Svendsen Clive N.
Published: July 2006

Excitatory amino acids such as glutamate play important roles in the central nervous system. We previously demonstrated that a neurosteroid, dehydroepiandrosterone (DHEA), has powerful effects on the cell proliferation of human neural progenitor cells (hNPC) derived from the fetal cortex, and this effect is modulated through NMDA receptor signaling. Here, we show that glutamate can significantly increase the proliferation rates of hNPC. The increased proliferation could be blocked by specific NMDA receptor antagonists, but not other glutamate antagonists for kainate–AMPA or metabotropic receptors. The NR1 subunit of the NMDA receptor was detectable in elongated bipolar or unipolar cells with small cell bodies. These NR1‐positive cells were colocalized with GFAP immunoreactivity. Detection of the phosphorylation of cAMP response element‐binding protein (pCREB) revealed that a subset of NR1‐positive hNPC could respond to glutamate. Furthermore, we hypothesized that glutamate treatment may affect mainly the hNPC with a radial morphology and found that glutamate as well as DHEA selectively affected elongated hNPC; these elongated cells may be a type of radial glial cell. Finally we asked whether the glutamate‐responsive hNPC had an increased potential for neurogenesis and found that glutamate‐treated hNPC produced significantly more neurons following differentiation. Together these data suggest that glutamate stimulates the division of human progenitor cells with neurogenic potential.
Multi‐sited mutations of beta‐tubulin are involved in benzimidazole resistance and thermotolerance of fungal biocontrol agent Beauveria bassiana
Authors: Zou Gen , Ying Sheng‐Hua , Shen Zhi‐Chen , Feng Ming‐Guang
Published: July 2006

Fungicide resistance and thermotolerance of biocontrol agents in mitosporic fungi are of merits for enhancing fungal formulations against insect pests in the field. Among 20 wild strains of Beauveria bassiana (a well‐known fungal biocontrol agent) tested in this study, 19 were sensitive or highly sensitive to carbendazim (methyl 2‐benzimidazole carbamate), a typical benzimidazole fungicide, despite low resistance found in one strain. Sequential mutagenesis of a carbendazim‐sensitive wild strain [minimal inhibitory concentration (MIC) = 1.32 µg ml−1] under artificial selection pressure generated 11 mutants sharing a common MIC of > 1000 µg ml−1 without visible variation in colony growth and conidiation capacity. This represents at least 758‐fold enhancement of the resistance among the mutants. However, accompanied with the enhanced resistance, all the mutants became less thermotolerable. Stressed at 48°C, conidial LT50s of the mutants varied from 1.8 to 9.6 min and were lower than the parental LT50 (36 min). Moreover, the contents of hydrophobin‐like proteins in conidial walls declined significantly among the mutants compared with that of the wild parent. Mutations commonly relating to benzimidazole resistance in fungi were located at Q134, F167 and/or E198 around the taxol‐binding site of beta‐tubulin by sequencing the beta‐tubulin of the mutants. Also, mutations of other 37 amino acid residues in the sequences (each having one to five residues mutated) were found for the first time and they were diverse in spatial structure. All mutations restricted to the half of beta‐tubulin close to alpha‐tubulin were likely involved in variation in each of the traits concerned but their interactions were complicated.
Criblamydia sequanensis, a new intracellular Chlamydiales isolated from Seine river water using amoebal co‐culture
Authors: Thomas Vincent , Casson Nicola , Greub Gilbert
Published: July 2006

Accumulating evidence supports a role for Chlamydia‐related organisms as emerging pathogens for human and animals. Assessment of their pathogenicity requires strain availability, at least for animal models and serological studies. As these obligate intracellular species are able to grow inside amoebae, we used co‐culture with Acanthamoeba castellanii in an attempt to recover new Chlamydia‐related species from river water. We isolated two strains from eight water samples. The first strain is a new Parachlamydia acanthamoebae strain that differs from previously described isolates by only two bases in the complete 16S rRNA gene sequence. The second isolate is the first representative of a new Chlamydiales family, as demonstrated by genetic and phylogenetic analyses of the 16S rRNA, 23S rRNA, ADP/ATP translocase and RnpB encoding genes. Using fluorescent in situ hybridization and electron microscopy, we demonstrated that it grows in high numbers in amoebae, where it exhibits a Chlamydia‐like developmental cycle with reticulate bodies and star‐like elementary bodies. Based on these results, we propose to name this new species ‘Criblamydia sequanensis’. This work confirmed that amoebal co‐culture is a relevant method to isolate new chlamydiae, and that it can be successfully applied to ecosystems colonized with a complex microbial community.
Obesity and disability – a short review
Authors: Ells L. J. , Lang R. , Shield J. P. H. , Wilkinson J. R. , Lidstone J. S. M. , Coulton S. , Summerbell C. D.
Published: July 2006

The prevalence of both obesity and disability is increasing globally and there is now growing evidence to suggest that these two health priorities may be linked. This paper explores the evidence linking obesity to muscular‐skeletal conditions, mental health disorders and learning disabilities in both adult and child populations. The impact of obesity on the four most prevalent disabling conditions in the UK (arthritis, mental health disorders, learning disabilities and back ailments) has been examined through novel data analysis of the 2001 Health Survey for England and UK Back Exercise And Manipulation trial data. Together these analyses strongly suggest that whether the cause or result of disability, obesity is undeniably implicated, thus presenting a serious public health priority. Future research efforts are required to strengthen the evidence base examining obesity in back disorders, mental health and learning disabilities, in order to improve current clinical management.
Obesity in South Africa
Authors: Van Der Merwe M.‐T. , Pepper M. S.
Published: July 2006

South Africa has not been spared in the rampant global increase in obesity. Throughout Africa, as elsewhere, ethnicity has a major impact on the incidence and pathogenesis of comorbid diseases, particularly diabetes. Combined figures for obesity and overweight (body mass index [BMI] > 25 kg m−2) obtained across all ethnic groups in the adult population in 1998, were 57% for women and 29% for men. From the 1960s until the late 1980s, the notion of ‘healthy’ or ‘benign’ obesity was propagated in South Africa. Not surprisingly, this led to ignorance around the problem of obesity, and treatment of some of the comorbid diseases was neglected. Fortunately, as an increasing number of seminal studies draw us closer to reality, the misperception of benign obesity is being corrected. This is allowing us to address the real issues underlying the current epidemic, and to recognize and manage the comorbid diseases, in particular type 2 diabetes. A new framework for research is also emerging as we begin to define the factors underlying the impact of ethnicity on obesity.
The management of osteoarthritis in the obese patient: practical considerations and guidelines for therapy
Authors: Bliddal H. , Christensen R.
Published: July 2006

Obesity and osteoarthritis (OA) co‐exist in an increasing part of the population. The two diseases intertwine in several ways. The evolution in the population shows a tendency towards deterioration of both by increasing general age and weight. The two diseases share pathogenetic features and the development of one disease increases the risk of the other and may be the onset of a vicious circle. There is a link between treatments of these two diseases as well. There is now solid (gold) evidence that by treating effectively the obesity of patients with co‐occurring OA, the functional status is dramatically ameliorated; the short‐term results are equal to that of a joint replacement. The long‐term efficacy of a weight loss remains to be shown. OA is definitely one of many diseases in which obesity must be taken seriously into account when planning a correct treatment of patients. The regimens used in the controlled studies of such patients are reviewed and it may be concluded that practical aspects of the dietary intervention in obese patients with OA are not different from general recommendations.
The transition to an advanced organic economy: half a millennium of English agriculture1
Authors: WRIGLEY E. A.
Published: July 2006

All organic economies were subject to constraints upon growth for reasons familiar to the classical economists, but their relative success in coping with these constraints differed substantially. This is visible both when comparing different areas at the same point in time and when comparing the circumstances of a given economy at different points in time. In this article the state of the English economy in 1300 is compared with its state in 1800. At the former date the balance between output and population was unfavourable. A run of poor harvests spelled grave and widespread suffering. Five hundred years later this had ceased to be true. The particular focus of the article is upon the significance of a rising level of productivity per head in agriculture, not simply in supplying food but in providing the raw materials and energy needed if industry and transport were to expand. In the circumstances of an organic economy both were heavily dependent upon the ‘surplus’ made available by a productive agriculture after meeting the needs of the population for food.
Comment on ‘Seat of Death and Terror’1
Authors: LEUNIG TIMOTHY , VOTH HANS‐JOACHIM
Published: July 2006

Oxley finds that smallpox consistently reduced heights, but that the fall was not statistically significant outside London or for juvenile Londoners. We demonstrate that inappropriate subdivision of the data into small samples explains the lack of significance she obtains. Further analysis of Oxley’s data shows that smallpox was a statistically significant cause of stunting, and that there were no differences in the effect by area. Juveniles exhibit greater stunting than adults, leading us to conclude that smallpox was not a proxy for overcrowding. That smallpox reduced height is important for anthropometric history: heights capture the effect of a truly awful disease.
Habitat specificity and home‐range size as attributes of species vulnerability to extinction: a case study using sympatric rattlesnakes
Authors: Waldron J. L. , Bennett S. H. , Welch S. M. , Dorcas M. E. , Lanham J. D. , Kalinowsky W.
Published: July 2006

Large home‐range size and habitat specificity are two commonly cited ecological attributes that are believed to contribute to species vulnerability. The eastern diamondback rattlesnake Crotalus adamanteus is a declining species that occurs sympatrically with the more abundant canebrake rattlesnake Crotalus horridus in a portion of the south‐eastern Coastal Plain, USA. In this study, we use the ecological similarities of the two species as experimental controls to test the role of home‐range size and habitat specificity in the imperilment of the eastern diamondback rattlesnake. We used analysis of variance to investigate differences in home‐range size between the two species, and home‐range selection was modeled as habitat use versus availability with a case control sampling design using logistic regression. We failed to detect differences in home‐range size between the two species; therefore, we could not identify home‐range size as an attribute contributing to the imperilment of eastern diamondback rattlesnakes. Eastern diamondback rattlesnakes selected pine savannas to a degree that suggests that the species is a habitat specialist. Of the two factors examined, habitat specificity to the imperiled longleaf pine ecosystem may be a significant contributor to the decline of the eastern diamondback rattlesnake.
Effects of an invasive anuran [the cane toad (Bufo marinus)] on the invertebrate fauna of a tropical Australian floodplain
Authors: Greenlees M. J. , Brown G. P. , Webb J. K. , Phillips B. L. , Shine R.
Published: July 2006

The ways in which invasive organisms influence native ecosystems remain poorly understood. For example, feral cane toads Bufo marinus have spread extensively through tropical Australia over the last 70 years, but assessments of their ecological impact remain largely anecdotal. We conducted experimental trials to examine the effect of cane toad presence on invertebrate fauna in relatively small (2.4 × 1.2 m) outdoor enclosures on a floodplain near Darwin in the wet–dry tropics. Toads significantly reduced invertebrate abundance and species richness, but only to about the same degree as did an equivalent biomass of native anurans. Thus, if toads simply replaced native anurans, the offtake of invertebrates might not be substantially different from that due to native anurans before toad invasion. However, our field surveys suggest that toads cause a massive (fourfold) increase in total amphibian biomass. The end result is that cane toads act as a massive nutrient sink in the floodplain ecosystem because they consume vast numbers of invertebrates but (unlike native frogs) are largely invulnerable to predation by frog‐eating predators.
Maternal exposure to low levels of ambient air pollution and preterm birth in Brisbane, Australia
Authors: Hansen C , Neller A , Williams G , Simpson R
Published: July 2006

Background  There is evidence that maternal exposure to ambient air pollution during pregnancy is associated with adverse birth outcomes.

Objective  To assess preterm birth (PTB) in relation to maternal exposure to ambient air pollution.

Design  Retrospective cohort.

Setting  Brisbane, Australia.

Sample  A total of 28 200 singleton live births for the period of 1 July 2000 to 30 June 2003.

Methods  Average maternal exposure estimates for ambient particulate matter (PM10 and bsp), ozone (O3) and nitrogen dioxide were calculated over the first 3 months after last menstrual period (LMP) and the last 3 months prior to birth (individually and combined as trimesters).

Main outcome measures  PTB was defined as gestation <37 weeks and odds ratios (OR) were calculated for PTB per interquartile range increase in the maternal exposure estimate for each pollutant. Various covariates were controlled for, including season of birth.

Results  Exposure to PM10 and O3 during trimester one was associated with an increased risk of PTB (OR = 1.15, 95% CI 1.06–1.25 and OR = 1.26, 95% CI 1.10–1.45, respectively). The PM10 exposure effect associated with trimester one was strongly related to exposure during the first month post‐LMP (PM10, month one; OR = 1.19, 95% CI 1.13–1.26).

Conclusion  These results suggest that maternal exposure to low levels of ambient air pollution is associated with PTB.
Referral and attendance at a specialist antenatal clinic: qualitative study of women’s views
Authors: Jackson CJ , Bosio P , Habiba M , Waugh J , Kamal P , Dixon‐Woods M
Published: July 2006

Objective  To explore women’s views on being referred to and attending a specialist antenatal hypertension clinic.

Design  Qualitative interview study.

Setting  A pregnancy hypertension clinic in a large teaching hospital in the East Midlands.

Population  Twenty‐one women (aged 18 years and above) attending the pregnancy hypertension clinic for the first time during their current pregnancy.

Methods  Women who had been referred to and attended a specialist antenatal clinic participated in semi‐structured interviews. Data analysis was based on the constant comparative method.

Main outcome measures  Women’s experiences and perceptions of being referred to and attending a specialist antenatal clinic.

Results  Being referred to the clinic conferred an ‘at risk’ status on women. Some women welcomed the referral but others experienced it as unsettling. Many were unclear about why they had been identified as being at risk or had difficulties in accepting the legitimacy of the reason for referral. Women were often inadequately informed about why they were referred to the clinic, what they could expect and the benefits of attending the clinic over management in the community. Although attendance at the clinic was cited as a source of reassurance, the reassurance was often made necessary by concern raised by the initial referral.

Conclusions  Women’s accounts suggest that the interface between community and secondary antenatal services needs improvement to minimise possible adverse effects from identifying women as being ‘at risk’ during pregnancy.
Which factors determine the sexual function 1 year after childbirth?
Authors: Van Brummen HJ , Bruinse HW , Van De Pol G , Heintz APM , Van Der Vaart CH
Published: July 2006

Objective  To evaluate which factors determine sexual activity and satisfaction with the sexual relationship 1 year after the first delivery.

Design  Prospective longitudinal cohort study.

Setting  Ten midwifery practices.

Population  Three hundred and seventy‐seven nulliparous women were included.

Methods  The Maudsley Marital Questionnaire is a standardised and validated questionnaire with 15 items relating to marital and sexual adjustment, with a nine‐point (0–8) scale appended to each question. Scores on the sexual scale (MMQ‐S) range from 0 to 40. Higher scores are indicative of greater dissatisfaction. Sexual intercourse was dichotomised into having sexual intercourse or not having sexual intercourse. Several obstetric and maternal factors were analysed.

Main outcome measurements  Sexual intercourse at 1 year postpartum and dissatisfaction with the sexual relationship as assessed by the MMQ‐S scale.

Results  In multiple logistic regression analysis, the main predictive factor for no sexual intercourse 1 year postpartum was no sexual intercourse at 12 weeks of gestation (β 11.0 [4.01–30.4]). Women were five times less likely to be sexually active after a third/fourth degree anal sphincter tear as compared with women with an intact perineum (β 0.2 [0.04–0.93]). Dissatisfaction with the sexual relationship 1 year after childbirth, assessed with the MMQ‐S scale, is associated with not being sexually active at 12 weeks of gestation (β– 0.208, P= 0.004) and with an older maternal age at delivery (β 0.405, P= 0.032).

Conclusion  An important prognostic factor for dissatisfaction with the sexual relationship 1 year postpartum was not being sexually active in early pregnancy. Satisfaction with the sexual relationship seems not to depend on pregnancy‐ and parturition‐associated factors.
‘A stronger and clearer perception of self’. Women’s experience of being professional patients in teaching the pelvic examination: a qualitative study
Authors: Siwe K , Wijma B , Berterö C
Published: July 2006

Objectives  To identify and describe the experience of being a professional patient (PP) in teaching the pelvic examination (PE).

Design  Qualitative study using in‐depth interviews.

Setting  Participant’s home, place of work or other place of choice.

Population  Thirteen female PPs who teach the PE to medical students and student midwives.

Method  Semi‐structured interviews analysed with an interpretive phenomenological approach.

Main outcome measures  Five themes were identified during the analysis: ‘embodied knowledge’, ‘promoting a proper approach’, ‘redrawing private boundaries’, ‘feeling confident’ and ‘doing something meaningful’. The essence ‘experience of stronger and clearer perception of self’ emerged from the themes and is the described structure of the lived experience of the women who are PP.

Conclusions  Being a PP in this setting was beneficial for the women. They acquired increased knowledge about their bodies and PE procedure, which led to a new awareness of their own body. Contributing to students’ learning in such an intimate examination procedure was rewarding and increased self‐esteem.
The effect of maternal methadone use on the fetal heart pattern: a computerised CTG analysis
Authors: Navaneethakrishnan R , Tutty S , Sinha C , Lindow SW
Published: July 2006

Using a computerised analysis, the cardiotocograph (CTG) from women who use methadone (n= 25) when compared with women who do not use methadone (n= 25) showed a significant reduction in the fetal heart baseline rate, with a significant reduction in number of accelerations and episodes of high variation. The short‐term variation, number of decelerations and episodes of low variation were not different between the two groups. The time taken to meet the standardised criteria was not different, and it is possible that a computer‐assisted CTG analysis could be more accurate than a naked eye interpretation.
The effects of social status on biological aging as measured by white‐blood‐cell telomere length
Authors: Cherkas L. F. , Aviv A. , Valdes A. M. , Hunkin J. L. , Gardner J. P. , Surdulescu G. L. , Kimura M. , Spector T. D.
Published: July 2006

Low socio‐economic status (SES) is associated with a shortened life expectancy, but its effect on aging is unknown. The rate of white‐blood‐cell (WBC) telomere attrition may be a biological indicator of human aging. We tested the hypothesis that SES is associated with telomere attrition independent of known risk factors influencing the aging process. We studied 1552 female twins. A venous blood sample was taken from each twin and isolated WBCs used for extraction of DNA. Terminal restriction fragment length (TRFL) was measured. Questionnaire data were collected on occupation, education, income, smoking, exercise, height and weight. Standard multiple linear regression and multivariate analyses of variance tested for associations between SES and TRFL, adjusting for covariates. A discordant twin analysis was conducted on a subset to verify findings. WBC telomere length was highly variable but significantly shorter in lower SES groups. The mean difference in TRFL between nonmanual and manual SES groups was 163.2 base pairs (bp) of which 22.9 bp (∼14%) was accounted for by body mass index, smoking and exercise. Comparison of TRFL in the 17 most discordant SES twin pairs confirmed this difference. Low SES, in addition to the harmful effects of smoking, obesity and lack of exercise, appears to have an impact on telomere length.
Synthesis of reactive dyes based on the bis‐(N‐carboxymethylamino)monoquaternary‐triazine‐bis‐ethylsulphone reactive group. Part 1: Application to cotton cellulose
Authors: Lewis D M , Siddique A A
Published: July 2006

Reactive dyes containing the bis‐(N‐carboxymethylamino)monoquaternary‐triazine‐bis‐ethylsulphone [bis‐(N‐CMA)‐MQT‐bis‐ES] group and related derivatives have been synthesised. When boiled under mildly acidic conditions, such dyes are able to form two small vinylsulphone dye molecules through a process of 1,2‐trans elimination. The bis‐(N‐CMA)‐MQT‐bis‐ES dye was applied using different dyeing procedures (novel dyeing methods 1 and 2). The dyeing and soaping‐off results of bis‐(N‐CMA)‐MQT‐bis‐ES dye were compared with a model sulphatoethylsulphone dye applied using the conventional alkaline fixation method used for applying this type of reactive dye to cotton. The bis‐(N‐CMA)‐MQT‐bis‐ES dye showed higher exhaustion and fixation values applied using novel dyeing method 2 compared with the sulphatoethylsulphone dye applied using the alkaline fixation method. The soaping‐off efficiency for the large bis‐(N‐CMA)‐MQT‐bis‐ES dye applied using novel dyeing method 2 was the same as that obtained for the sulphatoethylsulphone dye applied using the alkaline fixation method.
The Role of Debt Purchases in Takeovers: A Tale of Two Retailers
Authors: Noe Thomas H. , Rebello Michael J.
Published: July 2006

In this paper, we examine acquisitions of two financially distressed retailers—Federated's takeover of Macy's, and Zell Chilmark's takeover of Carter Hawley Hale. In both cases the raider purchased some of the target's outstanding debt to launch its takeover attempt. These debt purchases appear to have been facilitated by two salient factors—the raider's expertise in dealing with distressed firm restructuring and the ability of the raider to acquire a large blockholding of debt. Our analysis indicates that, when these factors are present, it is optimal for a raider to initiate a takeover of a distressed firm through purchasing a block of the firm's debt. Target bondholder reaction will be favorable whereas shareholder reaction may be either favorable or unfavorable.
Observable Contracts as Commitments: Interdependent Contracts and Moral Hazard
Authors: Katz Michael L.
Published: July 2006

A large literature examines the use of observable and unrenegotiable agency contracts as commitments. These analyses generally impose an ad hoc restriction that contracts cannot be contingent on one another. I relax this restriction and obtain a folk theorem. Unlike earlier folk theorems in this area, the present result applies to agency relationships that have hidden‐action problems. Using an example, I also demonstrate that there are settings in which interdependent contracts support a strictly larger set of equilibrium outcomes than do independent contracts. The result highlights the critical need for careful thought about restrictions placed on the set of feasible contracts.
The Ignored Performance Measure
Authors: Laux Volker
Published: July 2006

This paper studies a setting in which a risk‐averse agent must be motivated to work on two tasks: evaluating a potential project and, if the project is adopted, implementing it. Although a performance measure that is informative of an agent's action is typically valuable because it can be used to improve the risk sharing of the contract, this is not necessarily the case in this two‐task setting. I provide a sufficient condition under which a performance measure that is informative of the agent's implementation effort is worthless for contracting despite the agent being risk averse. This shows that information content is a necessary but not a sufficient condition for a performance measure to be valuable.
Optimal Contracts for Long‐Term Decisions and the Threat of Dismissal
Authors: Kwon Illoong
Published: July 2006

This paper studies a simple agency model where an agent's decision can affect his or her own future payoffs as well as the principal's. The threat of dismissal becomes an important part of an incentive scheme even if the principal can use the performance‐based wage contract. However, if the agent's future payoffs depend on the past realized performance, but not on the past decision directly, or if the agent is risk‐neutral, it is not optimal to use the threat of dismissal. As the agent's discretion over his future payoffs increases, the principal relies more on the threat of dismissal but less on the wage contract.
Blood Pressure Level and Outcomes in Adults Aged 65 and Older with Prior Ischemic Stroke
Authors: Kaplan Robert C. , Tirschwell David L. , Longstreth W.T. , Manolio Teri A. , Heckbert Susan R. , LeValley Aaron J. , Lefkowitz David , El‐Saed Aiman , Psaty Bruce M.
Published: July 2006

OBJECTIVES: To examine the association between blood pressure (BP) levels and long‐term stroke outcomes in elderly stroke survivors.

DESIGN: Observational study.

SETTING: The Cardiovascular Health Study (CHS) of 5,888 community‐dwelling adults.

PARTICIPANTS: Two hundred fifty‐four adults aged 65 and older (mean age 78.6) who sustained a nonfatal first ischemic stroke.

MEASUREMENTS: BP levels assessed at prestroke and poststroke CHS visits were examined as predictors of stroke recurrence, coronary heart disease (CHD), combined vascular events (CVEs), and mortality.

RESULTS: Higher poststroke BP level, assessed 261.6 days (mean) after stroke, was associated with higher risk of stroke recurrence over 5.4 years (mean) of follow‐up. The multivariate‐adjusted hazard ratio for stroke recurrence was 1.42 (95% confidence interval (CI)=1.03–1.99) per standard deviation (SD) of systolic BP (P=.04) and 1.39 (95% CI=1.01–1.91) per SD of diastolic BP (P=.04). Mortality was significantly greater in patients with low or high poststroke BP than in those with intermediate BP. Poststroke BP was not associated with risk of CHD or CVE, although further analyses suggested that high systolic BP predicted CHD and CVE in younger but not older subjects. Prestroke BP did not predict poststroke outcomes.

CONCLUSION: In this observational study of adults aged 65 and older assessed approximately 8 months after stroke, low BP was associated with favorable risk of recurrent stroke, although high and low poststroke BP levels were associated with greater mortality. Long‐term antihypertensive trials in older stroke survivors would increase knowledge about the benefits of lowering BP in this population.
Postprandial Hypotension in Long‐Term Care Elderly Patients on Enteral Feeding
Authors: Lubart Emily , Segal Refael , Baumoehl Yehuda , Matron Marina , Leibovitz Arthur
Published: July 2006

OBJECTIVES: To examine the prevalence and nature of postprandial hypotension (PPH) in orally fed (OF), nasogastric tube (NGT)‐fed, and percutaneous endoscopic gastrostomy (PEG)‐fed older people.

DESIGN: Prospective comparative study.

SETTING: Nursing and skilled nursing wards of three geriatrics hospitals.

PARTICIPANTS: Three groups (OF, PEG, NGT) of long‐term care patients (50 in each cohort) were enrolled.

MEASUREMENTS: Blood pressure (BP) and heart rate measurements were obtained just before lunch and at 15‐minute intervals for 90 minutes after the completion of the meal. The meals were similar in caloric content and composition.

RESULTS: PPH was evidenced in 64 (43%) patients. No significant intergroup (OF, PEG, NGT) differences were present. In 68% of PPH patients, the systolic BP (SBP) drop appeared within 30 minutes, and 70% reached their systolic nadir at 60 minutes. In 31%, the SBP drop was registered on only one measurement, whereas in 25%, the drop was detected on five to six measurements. All parameters were without notable intergroup differences.

CONCLUSION: In enterally fed elderly patients (NGT or PEG), the rate and pattern of PPH are similar and not significantly different from that observed in OF patients.
Severe Elder Obesity and 1‐Year Diminished Lower Extremity Physical Performance in Homebound Older Adults
Authors: Sharkey Joseph R. , Ory Marcia G. , Branch Laurence G.
Published: July 2006

OBJECTIVES: To determine whether severe obesity in older people is independently associated with diminished lower extremity physical performance (LEP) in a random sample of homebound older adults that were considered ambulatory.

DESIGN: Prospective cohort with 1 year of follow‐up (2000–02).

SETTING: In‐home assessments of homebound older adults in four North Carolina counties.

PARTICIPANTS: Random sample of 282 home‐delivered meal recipients aged 60 and older who completed both in‐home assessments (n=253) or were nursing home residents (n=29) at the 1‐year follow‐up assessment of the Nutrition and Function Study.

MEASUREMENTS: Objective measures were selected for baseline and 1‐year LEP (timed walking, static and dynamic balance, and chair rise) and baseline body mass index (BMI, based on measured weight and knee height). BMI was categorized as underweight/normal (<25.0 kg/m2), overweight (25.0–29.9 kg/m2), moderately obese (30.0–34.9 kg/m2), and severely obese (≥35.0 kg/m2). Based on summary scores, overall LEP was categorized as poor, intermediate, or good. Sample characteristics included depressive symptomatology, fear of falling, medical conditions, and medication use.

RESULTS: Almost 23% of participants were moderately obese and 15% severely obese. Only severe obesity independently increased the odds (odds ratio 2.9–7.0) for diminished performance at 1 year in individual tests and in overall LEP performance. Severe obesity was independently associated with poor LEP at both assessments or with decline in LEP at 1 year.

CONCLUSION: These results highlight the need to distinguish between moderate and severe obesity in older people in terms of relationships with key functional outcomes. The findings identify severe obesity in older people as an important target for future interventions. In particular, this calls for greater understanding of intervention goals, whether to primarily target weight reduction or improvement in physical performance.
Energy‐Containing Nutritional Supplements Can Affect Usual Energy Intake Postsupplementation in Institutionalized Seniors with Probable Alzheimer's Disease
Authors: Parrott Matthew D. , Young Karen W. H. , Greenwood Carol E.
Published: July 2006

OBJECTIVES: To determine whether increases in caloric intake associated with consumption of a mid‐morning nutritional supplement for 3 weeks were maintained in the week after stopping the supplement and to investigate the effects of body mass index (BMI) and cognitive and behavioral measures on this response.

DESIGN: Secondary analysis of a previously published randomized, crossover, nonblinded clinical trial.

SETTING: A fully accredited geriatric care facility affiliated with the University of Toronto.

PARTICIPANTS: Thirty institutionalized seniors with probable Alzheimer's disease (AD) who ate independently.

MEASUREMENTS: Investigator‐weighed food intake, body weight, cognitive (Severe Impairment Battery; Global Deterioration Scale) and behavioral (Neuropsychiatric Inventory—Nursing Home version; London Psychogeriatric Rating Scale) assessments.

RESULTS: Individuals who responded successfully to supplementation as indicated by increases in daily energy intake were likely to maintain 58.8% of that increase postsupplementation, although stopping the supplement was associated with decreased habitual energy intake in low‐BMI individuals who reduced their daily intakes during supplementation in response to the extra calories. Cognitive/behavioral tests were not reliable predictors of postsupplement intake.

CONCLUSION: Institutionalized seniors with probable AD are likely to alter their usual energy intakes to maintain changes resulting from 3 weeks of supplementation. This effect may allow for rotating supplementation schedules in nursing homes that could reduce staff burden, but only for those individuals who are most likely to respond favorably. These data indicate that nutritional supplements and diet plans should be carefully prescribed in low‐BMI individuals to limit variability in total energy provided and thus prevent lower‐than‐normal intake.
Clinical indices of familial depression in the Swedish Twin Registry
Authors: Kendler K. S. , Gatz M. , Gardner C. O. , Pedersen N. L.
Published: July 2006

Objective:  Although familial factors certainly contribute to the etiology of major depression (MD), further information is needed about which clinical features of depressive illness index the familial vulnerability in MD.

Method:  Lifetime MD and associated clinical features were assessed at personal interview in 27 230 individual twins, including 4080 onsets of MD, from the Swedish National Twin Registry. Analyses were conducted using Cox proportional hazards models.

Results:  Three clinical variables in a depressed twin predicted the hazard ratio for MD in the cotwin. In the order of the strength of the association, these were: number of endorsed A criteria, age at onset, and number of episodes.

Conclusion:  Certain clinical features of MD are significant, albeit modest, indices of the familial vulnerability to MD. Individuals with a high familial/genetic risk for MD tend to have an early age at onset, meet most of the symptomatic DSM criteria and suffer recurrences.
Increased expression of integrins and decreased apoptosis correlate with increased melanocyte retention in cultured skin substitutes
Authors: Swope Viki B. , Supp Andrew P. , Schwemberger Sandy , Babcock George , Boyce Steven
Published: July 2006

Losses of human melanocytes (HM) in transplantation of cultured skin substitutes (CSS) may result from poor cellular attachments. To test this hypothesis, HM integrin expression was measured in four culture media: (a) melanocyte growth medium (MGM), an HM proliferation medium; (b) UCMC 160, a CSS maturation medium; (c) mMGM, modified MGM with 1.8 mM calcium; and (d) modified UCMC 160 with HM supplements (mUCMC 160). HM grew well in all media except UCMC 160. Increased expression of β1, β4, α3β1 and α5 integrins on HM cultured in MGM and mMGM versus UCMC 160 was found by flow cytometry. Annexin V‐allophycocyanin (APC) labeled HM in apoptosis and increased significantly in UCMC 160 (31.1%) compared with MGM (11.9%) or mMGM (13.9%). CSS were incubated in UCMC 160, mMGM or mUCMC 160 media, and grafted to athymic mice. In the mMGM group, grafts were darker as measured with a chromameter through 6 weeks and the average number of basal HM per field was greater at 12 weeks post‐grafting. Increased graft loss was observed in the mMGM group which corresponded with the poor epidermal morphology in vitro. Although HM retention improved in vivo using mMGM to culture the CSS, the stability of the epidermis decreased. These results indicate that expression of integrins on HM in vitro correlates with HM retention in CSS and short‐term survival after transplantation, but that long‐term survival depends also on stable epithelium.
Dentinal sensitivity: a natural mineral dietary supplement study
Authors: Rogo E , Hodges K , Herzog A
Published: July 2006

Abstract:  The purpose of the investigation was to determine the effect of drinking a natural mineral dietary supplement (NMDS) on gingival health and dentinal hypersensitivity. The NMDS product was from a geothermal source and contained 3.6 mg l−1 of fluoride and other minerals. Sample selection included subjects with gingival inflammation and sensitivity as well as screening for exclusion factors. A double‐blind randomized parallel approach was used. The investigation was a quasi‐experimental pre/post‐test design. The experimental group ingested and swished twice a day with the NMDS (1 l) and the control group followed the same regimen with a placebo containing de‐ionized water (DIW). Clinical measurements of gingival inflammation and dentinal sensitivity were taken at baseline, 4 and 8 weeks. Gingival inflammation was measured using the Gingival Index. Dentinal hypersensitivity was measured using a tactile stimulus and an evaporative stimulus. After each stimulus was applied, the subjects rated the amount of discomfort on a visual analogue scale from 0 to 10. Each set of data was analysed using anova and a post hoc probing technique to determine within‐ and between‐group differences (P = 0.05). The experimental and control groups (n = 70) experienced a statistically significant decrease in tactile and evaporative sensitivity scores over time; however, the between‐group differences were not significant. The gingival inflammation data were not statistically significant with regard to the within‐ and between‐group differences. Therefore the NMDS and DIW were equally effective in reducing dentinal hypersensitivity and neither product effectively reduced gingival inflammation.