bluuebunny/crossref_metadata_2025 huggingface dataset:
Representation in India's sacred images: objective vs. metaphysical
reference
Authors: CHARI V. K.
Published: October 2002

Coomaraswamy and other art interpreters have read into Indian images metaphysical
meanings extrapolated from scriptural sources. In this article it is argued
that such meanings, with which image-making was doubtless invested, were intended
for purposes of meditation and cannot be admitted as part of the objective
representation of the images, except where they figure as iconographical features.
The images were also not conceived as yantras, but as full-bodied
representations conforming to objective norms. The metaphysical excursions
are largely extraneous to the aesthetic assumptions of Indian art and detract
from its rich mythical content.
Spirit of stone: technical considerations in the treatment of the Jade Body
Authors: LO VIVIENNE
Published: October 2002

The early imperial period was a time of rapid change in medical ideas and practices in China. Manuscripts and artifacts excavated from tombs of the second century B.C. along the Yangtze river valley bring fresh insights into some of the processes involved in medical innovation in the early centuries of the empire. Through examining exorcistic practices and petty surgery to the refinement of a body sustained and nourished by physiological essences, this paper describes recurring patterns found in the changing medical techniques associated with stone, be that lancets, hot pressing stones or mineral prescription. After the transition to a culture of applying fine metal acupuncture needles vestiges of these treatments found in early Chinese stone culture remain enshrined in both the theory and practice of canonical medicine.
The Pali Subodhālankāra and Dandin's Kāvyādarśa
Authors: WRIGHT J. C.
Published: October 2002

The only notable works on poetics and prosody that survive in Pali are the Subodhālankāra (comprising, in effect, Kārikā and Vrtti) and Vuttodaya. They have been ascribed to the twelfth-century Sinhalese monk Sangharakkhita and described, almost from the outset, as ‘dependent upon Sanskrit models’ and ‘based entirely upon Sanskrit prosody’ respectively. Indeed the Vrtti names a ‘Dandi’ as its basic source. The Pali Text Society's 2000 edition of the Subodhālankāra, complete with two versions of the Vrtti, compiled by P. S. Jaini, has registered many, but by no means all of the parallel passages in Dandin's Kāvyādarśa, the seminal manual of Sanskrit poetic theory. The present article seeks to show that the Pali texts depend rather on earlier Middle Indian traditions of rhetoric and poetics, coupled with theories adumbrated in Nātyaśāstra. It is reasonably certain that the basic Pali material, especially as presented in the version with ‘Abhinavatīkā’, has been drawn upon by the author of the Sanskrit Kāvyādarśa; and there is evidence that the ‘Porānatīkā’ has been superficially influenced by the Sanskrit text. The material goes far to explain classical Sanskrit notions of Alamkāra, Rasa and Dhvani. The Pali prosody Vuttodaya seems to have been equally baselessly maligned, and should take its place along with surviving vestiges of Prakrit prosody as the fundamental link between Vedic and classical theory.
The cosmological context of sovereignty in Han times
Authors: LOEWE MICHAEL
Published: October 2002

By the Han empire, concepts of the cosmos were changing basically from that of the ‘Four Quarters’ (Si fang) to the ‘Five Phases’ (Wu xing), with a place for emperors to act as an essential pivot in the interlocking relationships of Heaven, Earth and Man. Differing views of the duty of monarchs may be discerned, e.g., in the memorials of Dong Zhongshu and the chapters of the Huainanzi, and the underlying questions could lead to antagonisms between emperors and kings, or between high-ranking officials of government and scholars of traditional writings. The part that individual Han emperors played in determining decisions of state may well be limited to a few instances. While it may be questioned how far they were conscious of the intellectual basis that supported their authority with its implied responsibilities, Wang Mang tried to exploit a view of the cosmos to assert his claim to power.
‘E-stablishing’ an Inclusive Society? Technology, Social Exclusion and UK Government Policy Making
Authors: SELWYN NEIL
Published: October 2002

In many industrialised countries information and communication technology
(ICT) is now being seen as a ready means through which
governments can address issues of social exclusion. Indeed, in the UK this
perspective has been quickly translated into a multi-billion pound policy
agenda aimed at using ICT for socially inclusive purposes. Yet, beyond
rhetorical concerns over bridging the perceived ‘digital divide’ and alleviating
disparities between the information ‘rich’ and ‘poor’, little critical
consideration has been given to how technology is being used by governments
to achieve socially inclusive aims. This paper therefore examines
the UK government’s ICT-based social policy drive through official documentation,
policy statements and political discourse – considering the
‘problems’ that it sets out to address, the substance of the policies, and
the perceived rationales and benefits for doing so. Having explored the
official construction of these policies, the paper then examines how well
founded this policy framework is in terms of achieving its stated aims of
widening access to ICT and effectively facilitating ‘social inclusion’. The
paper concludes by developing a critical perspective of such ICT policies
which reveals deeper economic rationales informing this ostensibly
‘social’ policy programme.
Mutual Obligation, Participation and Popularity: Social Security Reform in Australia
Authors: SAUNDERS PETER
Published: October 2002

Mutual obligation – the idea that those who receive assistance in times of
need should be required to ‘give something back’ – is the driving force
behind the current social security reform agenda in Australia. After more
than a decade of intense reform, the Australian Government is considering
a reform blueprint based on the recommendations of a Welfare
Reform Reference Group. These include proposals to increase mutual
obligation requirements on the unemployed and that sole parents and
disability support pensioners should be required to demonstrate some
form of social or economic participation in return for receiving income
support. Results from a national survey of public opinion are used to
explore community views on a range of mutual obligation requirements
for the unemployed. The analysis indicates that there is support for
mutual obligation for the young and long-term unemployed, but not for
others, such as the older unemployed, those caring for young children
and those with a disability. Most people also see mutual obligation as
implying action on the part of government to reduce unemployment and
ease the plight of the unemployed.
The Actress and Utopian Theatre Reform in Eighteenth-Century France: Riccoboni, Rousseau, and Restif
Authors: Scott Virginia
Published: October 2002

Three eighteenth-century writers, the actor Luigi Riccoboni, the philosophe Jean-Jacques Rousseau, and the printer-pornographer Nicolas Restif de la Bretonne, wrote antitheatrical or reform treatises identifying women as a significant source of ‘mortal poison’ in the theatre. Although Rousseau saw no way to purify or redeem the stage, the others proposed various bizarre reforms that would reduce or control the power of predatory female sexuality to seduce male audience members. These treatises reveal the depth of eighteenth-century misogyny during the so-called ‘reign of women’. Powerful women – and the stars of the Paris stage were powerful, economically independent, sexually liberated, and iconic – threatened male hegemony and provoked retaliation.
The USA national parks in international perspective: have we learned the wrong lesson?
Authors: Schelhas John
Published: October 2002

A highly polarized debate has emerged in the conservation literature about whether national parks in lesser developed countries should follow a strict protectionist model or find ways to accommodate the development and livelihood needs of local people. A number of social science critiques of national park practice and policy in lesser developed countries have argued that one of the chief problems facing national parks in particular, and biodiversity conservation in general, has been the USA national park model, often termed the ‘Yellowstone model’. This model, in which local and indigenous people and uses have been excluded from parks, has been blamed for harming local people, providing benefits to developed country interests at the expense of local people, high costs of park protection, and ineffective biodiversity conservation (Machlis & Tichnell 1985; West & Brechin 1991; Pimbert & Pretty 1995). Alternatives (henceforth referred to as ‘parks and people’ approaches) seek accommodations between parks and local people, and include community-based conservation, which promotes local involvement and/or control in park decision-making, and integrated conservation and development projects, which attempt to ensure conservation by meeting social and economic needs of local people through agroforestry, forestry, tourism, water projects, extractive reserves, and wildlife utilization.
Degradation of marine ecosystems and decline of fishery resources in marine protected areas in the US Virgin Islands
Authors: Rogers Caroline S. , Beets Jim
Published: October 2002

The large number of marine protected areas (MPAs) in the Caribbean (over 100) gives a misleading impression of the amount of protection the reefs and other marine resources in this region are receiving. This review synthesizes information on marine resources in two of the first MPAs established in the USA, namely Virgin Islands National Park (1962) and Buck Island Reef National Monument (1961), and provides compelling evidence that greater protection is needed, based on data from some of the longest running research projects on coral reefs, reef fish assemblages, and seagrass beds for the Caribbean. Most of the stresses affecting marine resources throughout the Caribbean (e.g. damage from boats, hurricanes and coral diseases) are also causing deterioration in these MPAs. Living coral cover has decreased and macroalgal cover has increased. Seagrass densities have decreased because of storms and anchor damage. Intensive fishing in the US Virgin Islands has caused loss of spawning aggregations and decreases in mean fish size and abundance. Groupers and snappers are far less abundant and herbivorous fishes comprise a greater proportion of samples than in the 1960s. Effects of intensive fishing are evident even within MPA boundaries. Although only traditional fishing with traps of ‘conventional design’ is allowed, commercial trap fishing is occurring. Visual samples of fishes inside and outside Virgin Islands National Park showed no significant differences in number of species, biomass, or mean size of fishes. Similarly, the number of fishes per trap was statistically similar inside and outside park waters. These MPAs have not been effective because an unprecedented combination of natural and human factors is assaulting the resources, some of the greatest damage is from stresses outside the control of park managers (e.g. hurricanes), and enforcement of the few regulations has been limited. Fully functioning MPAs which prohibit fishing and other extractive uses (e.g. no-take marine reserves) could reverse some of the degradation, allowing replenishment of the fishery resources and recovery of benthic habitats.
Emissions trading and environmental justice: distributive fairness and the USA's Acid Rain Programme
Authors: Corburn Jason
Published: October 2002

As emissions trading regimes become increasingly popular mechanisms for environmental pollution control around the world, environmentalists are asking whether market-based programmes meet their promise of both efficient and equitable pollution reductions. The emissions trading regime of the USA's Acid Rain Programme (ARP) is investigated in order to determine whether the programme has concentrated sulphur dioxide (SO2) pollution disproportionately for the poor and people of colour. While the USA emissions trading regime has been hailed as a success for cost-efficiently reducing pollution in the aggregate, critics contend that the programme is insufficiently attentive to the localized concentrations of harmful SO2 that trading can create. Further, advocates of environmental justice question whether emissions trading might exacerbate the disproportionate pollution burdens already facing the poor and people of colour. Stack emissions and pollution allowance holdings for all 110 power plants participating in Phase I of the trading programme are correlated with income and racial demographic characteristics of the people living around each plant to determine whether the ARP might raise distributive environmental justice concerns. Using USA Census data at the tract level, income and racial demographics around plants that increased and decreased their emissions as well as plants that were net purchasers and sellers of pollution allowances over the first three years of the programme are compared. For the first few years of the ARP, the emissions trading regime does not appear to have been concentrating SO2 pollution disproportionately for the poor and racial minority populations.
Transmission patterns of African horse sickness and equine encephalosis viruses in South African donkeys
Authors: LORD C. C. , VENTER G. J. , MELLOR P. S. , PAWESKA J. T. , WOOLHOUSE M. E. J.
Published: October 2002

African horse sickness (AHS) and equine encephalosis (EE) viruses are endemic to southern Africa. AHS virus causes severe epidemics when introduced to naive equine populations, resulting in severe restrictions on the movement of equines between AHS-positive and negative countries. Recent zoning of South Africa has created an AHS-free zone to facilitate equine movement, but the transmission dynamics of these viruses are not fully understood. Here, we present further analyses of serosurveys of donkeys in South Africa conducted in 1983–5 and in 1993–5. Age-prevalence data are used to derive estimates of the force of infection, λ. For both viruses, λ was highest in the northeastern part of the country and declined towards the southwest. In most of the country, EE virus had a higher transmission rate than AHS. The force of infection increased for EE virus between 1985 and 1993, but decreased for AHS virus. Both viruses showed high levels of variation in transmission between districts within the same province, particularly in areas of intermediate transmission. These data emphasize the focal nature of these viruses, and indicate areas where further data will assist in understanding the geographical variation in transmission.
Assessment of the factors associated with flavivirus seroprevalence in a population in Southern Vietnam
Authors: BARTLEY L. M. , CARABIN H. , VINH CHAU N. , HO V. , LUXEMBURGER C. , HIEN T. T. , GARNETT G. P. , FARRAR J.
Published: October 2002

Dengue and Japanese encephalitis flaviviruses cause severe disease and are hyperendemic in southern Vietnam. This study assesses associations between sociodemographic factors and flavivirus seroprevalence in this region. Sera were collected from 308 community and hospital-based subjects between April 1996 and August 1997 and tested with an indirect ELISA. The factors associated with seroprevalence were assessed using multivariate logistic regression. In this first report of adjusted prevalence odds ratios (POR) for flavivirus infection in Vietnam, seropositivity was associated with increasing age in children (multiple regression coefficients for a child compared to an adult =−4·975 and for age in children = 0·354) and residence in the city compared to surrounding rural districts. The association with age indicates that subjects were most likely to have acquired infection in early childhood. This is key to the design of Vietnamese health education and immunization programmes.
Detection of delayed vaccinations: a new approach to visualize vaccine uptake
Authors: LAUBEREAU B. , HERMANN M. , SCHMITT H. J. , WEIL J. , VON KRIES R.
Published: October 2002

For the prevention of pertussis and invasive Haemophilus influenzae type b (Hib) infections, each with a peak for mortality and serious complications in the first year of life, early vaccination is important and needs adequate monitoring. In a 1999 national coverage survey the timing of uptake of these vaccines in German children was therefore assessed conventionally at defined age thresholds and with a new adaptation of the Kaplan–Meier (KM) method estimating immunization uptake over time by 1 minus the survival function s(t). Only 6% and 9% of children were vaccinated against pertussis and Hib in accordance with the national recommended primary vaccination schedule. Coverage levels for the primary vaccination course of 50% and 90% were attained for pertussis after 6·6 and 16·3 months respectively and for Hib after 7·0 and 24·3 months. These estimates were only possible with the KM method which proved useful to monitor vaccination programmes and will allow the comparison of vaccination uptake in different populations.
Quantification of transmission in one-to-one experiments
Authors: VELTHUIS A. G. J. , DE JONG M. C. M. , DE BREE J. , NODELIJK G. , VAN BOVEN M.
Published: October 2002

We study the statistical inference from data on transmission obtained from one-to-one experiments, and compare two algorithms by which the reproduction ratio can be quantified. The first algorithm, the transient state (TS) algorithm, takes the time course of the epidemic into account. The second algorithm, the final size (FS) algorithm, does not take time into account but is based on the assumption that the epidemic process has ended before the experiment is stopped. The FS algorithm is a limiting case of the TS algorithm for the situation where time tends to infinity. So far quantification of transmission has relied almost exclusively on the FS algorithm, even if the TS algorithm would have been more appropriate. Its practical use, however, is limited to experiments with only a few animals. Here, we quantify the error made when the FS algorithm is applied to data of one-to-one experiments not having reached the final size. We conclude that given the chosen tests, the FS algorithm underestimates the reproduction ratio R0, is liberal when testing H0[ratio ]R0[ges ]1 against H1[ratio ]R0<1, is conservative when testing H0[ratio ]R0[les ]1 against H1[ratio ]R0>1 and calculates the same probability as the TS algorithm when testing H0[ratio ]R0-control = R0-treatment against H1[ratio ]R0-control>R0-treatment. We show how the power of the test depends on the duration of the experiments and on the number of replicates. The methods are illustrated by an application to porcine reproductive and respiratory syndrome virus (PRRSV).
Pyrazinamide resistance associated with pncA gene mutation in Mycobacterium tuberculosis in Japan
Authors: ENDOH T. , YAGIHASHI A. , UEHARA N. , KOBAYASHI D. , TSUJI N. , NAKAMURA M. , HAYASHI S. , FUJII N. , WATANABE N.
Published: October 2002

Thirty Japanese clinical isolates of Mycobacterium tuberculosis were analysed by pyrazinamide susceptibility testing and pyrazinamidase assay, as well as polymerase chain reaction for single-strand conformational polymorphism and direct sequencing of the gene encoding pyrazinamidase (pncA). All sensitive isolates showed pyrazinamidase activity and a wild-type pncA gene, but three resistant isolates had pncA gene mutations and lacked pyrazinamidase activity. The latter isolates showed a minimum inhibitory concentration of at least 100 mg/l by the 7H10 agar proportion method and 400 mg/l by the 7H9 liquid medium method. Isolate 28 showed T-to-C change at position 11, leading to Leu4→Ser substitution; isolate 29 had an 8-bp deletion from position 382; and isolate 30 had A-to-C change at position 29, leading to Gln10→Pro substitution. The deletion has not been described previously. This is the first demonstration of pncA gene mutations in PZA-resistant M. tuberculosis strains isolated from Japanese patients.
Attachment, parenting, and marital dissatisfaction as predictors of disruptive behavior in
preschoolers
Authors: DEVITO CRYSTAL , HOPKINS JOYCE
Published: October 2002

The aim of this study was to examine if an insecure coercive attachment pattern is associated
with disruptive behavior in preschoolers, as well as to examine the concurrent and joint effects of
attachment pattern, marital dissatisfaction, and ineffective parenting practices on disruptive
behavior. Participants included 60 preschoolers and their mothers, recruited from three sites to
ensure an adequate range of disruptive behavior. The Preschool Assessment of Attachment
(Crittenden, 1992) was used to measure attachment pattern. Results of an analysis of variance
revealed that children in the coercively attached dyads scored significantly higher on the measure
of disruptive behavior than either the defended or secure children. Results of a hierarchical
regression analysis indicated that the combination of a coercive pattern of attachment, marital
dissatisfaction, and permissive parenting practices accounted for a significant proportion of the
variance in disruptive behavior in preschoolers. These data suggest that a specific type of insecure
attachment, a coercive pattern, is associated with disruptive behavior in preschoolers. Also, the
data are consistent with previous findings of associations among marital dissatisfaction, ineffective
parenting practices, and disruptive behavior.
The development of dissociation in maltreated preschool-aged children
Authors: MACFIE JENNY , CICCHETTI DANTE , TOTH SHEREE L.
Published: October 2002

Dissociation reflects disruptions in the integration of memories, perception, and identity into a
coherent sense of self, and may develop following childhood maltreatment. The preschool years
were identified as an important period for the development of dissociation. However, prior
research has not examined the development of dissociation during this time. In order to address
this gap, evidence of dissociation in 45 maltreated children, assessed for sexual abuse, physical
abuse, and neglect, was compared with dissociation in 33 nonmaltreated children. Rather than
depend on adult observer reports of behavior, the study sought to gain an understanding of
dissociation from the child's own point of view. Because self-reports have limitations with
such young children, a measure of dissociation evidenced in children's narrative story-stem
completions was utilized. Maltreated children, especially physically abused children and sexually
abused children, demonstrated more dissociation than did nonmaltreated children. Moreover,
during the preschool period maltreated and nonmaltreated children followed different trajectories
such that dissociation increased for maltreated children but did not do so for nonmaltreated
children. Findings suggest that although the self is normatively integrated during the preschool
period, it becomes increasingly fragmented for some maltreated children. Results are discussed in
terms of cascading effects of maltreatment throughout development, and the importance of
developmentally sensitive interventions.
Correlates of clinic referral for early conduct problems: Variable- and person-oriented
approaches
Authors: GREENBERG MARK T. , SPELTZ MATTHEW L. , DEKLYEN MICHELLE , JONES KAREN
Published: October 2002

The current study utilized both variable- and person-oriented analyses to examine correlates
of early disruptive behavior problems. Participants included 80 preschool boys referred to a child
psychiatry clinic and diagnosed with oppositional defiant disorder (with or without
attention-deficit hyperactivity disorder) and 80 case-matched normal comparison boys. The study
examined four domains of correlates: vulnerable child characteristics, poor parenting practices,
insecure attachment, and adverse family ecology. Results indicated that the combination of these
factors provided relatively high sensitivity (81%) and specificity (85%), clearly
differentiating referred from comparison boys. A dramatic increase in clinic status occurred when
three or more factors were present, and specific combinations of factors were differentially
predictive of conduct problems. However, no correlates were found to be either necessary or
sufficient for clinic status. By maintaining the integrity of individual cases, person-oriented
analyses were able to answer different questions than more traditional variable-oriented analyses.
Discussion focuses on the value of person-oriented analyses for understanding heterogeneous
clinical groups.
Effects of grade retention on academic performance and behavioral development
Authors: PAGANI LINDA , TREMBLAY RICHARD E. , VITARO FRANK , BOULERICE BERNARD , MCDUFF PIERRE
Published: October 2002

This study examined the controversial practice of grade retention and children's
academic and behavioral adjustment using data from the Quebec Longitudinal Study of
Kindergarten Children. We employed an autoregressive modeling technique to detect the impact
of being held back during primary school on subsequent academic performance and behavioral
development until age 12 years. The results indicate both a short- and long-term negative
influence on academic performance for boys and girls. Children's anxious, inattentive, and
disruptive behaviors persisted and, in some cases, worsened after grade retention. These
prospective associations were long lasting and more pronounced when grade retention occurred
early in primary school. Boys were more vulnerable to the negative influence of grade retention
on academic performance and classroom disruptiveness. Disruptive behavior in girls was
comparatively less associated with long-term consequences than boys. Nevertheless, girls
experienced both short- and long-term academic performance problems in the aftermath of grade
retention. Children's prosocial behavior appeared unaffected by grade retention. These
results are independent of what would have been expected by the natural course of academic and
behavioral development.
Socialization of children's emotion regulation in mother–child dyads:
A developmental psychopathology perspective
Authors: SHIPMAN KIMBERLY L. , ZEMAN JANICE
Published: October 2002

This study investigated the socialization of children's emotion regulation in 25
physically maltreating and 25 nonmaltreating mother–child dyads. Maltreating mothers and
their 6- to 12-year-old children were recruited from two parenting programs affiliated with
Children's Protective Services with a control group matched on race, SES, child gender,
and child age. Children and their mothers were interviewed individually about their (a)
management of emotional expression, (b) strategies for coping with emotional arousal, and (c)
anticipated consequences following emotional displays. Compared to controls, maltreated children
expected less maternal support in response to their emotional displays, reported being less likely
to display emotions to their mothers, and generated fewer effective coping strategies for anger.
Maltreating mothers indicated less understanding of children's emotional displays and fewer
effective strategies for helping children to cope with emotionally arousing situations than
nonmaltreating mothers. Further, findings indicated that maternal socialization practices (e.g.,
providing support in response to children's emotional display, generating effective coping
strategies for their child) mediate the relation between child maltreatment and children's
regulation of emotional expression and emotional arousal. These findings suggest that
children's emotion regulation strategies are influenced by their relationship with their social
environment (e.g., physically maltreating, nonmaltreating) and that the experience of a physically
maltreating relationship may interfere with children's emotional development.
Direct inhibition by cannabinoids of human 5‐HT3A receptors: probable involvement of an allosteric modulatory site
Authors: Barann M , Molderings G , Brüss M , Bönisch H , Urban B W , Göthert M
Published: October 2002

Excised outside‐out patches from HEK293 cells stably transfected with the human (h) 5‐HT3A receptor cDNA were used to determine the effects of cannabinoid receptor ligands on the 5‐HT‐induced current using the patch clamp technique. In addition, binding studies with radioligands for 5‐HT3 as well as for cannabinoid CB1 and CB2 receptors were carried out.

The 5‐HT‐induced current was inhibited by the following cannabinoid receptor agonists (at decreasing order of potency): Δ9‐THC, WIN55,212‐2, anandamide, JWH‐015 and CP55940. The WIN55,212‐2‐induced inhibition was not altered by SR141716A, a CB1 receptor antagonist. WIN55,212‐3, an enantiomer of WIN55,212‐2, did not affect the 5‐HT‐induced current.

WIN55,212‐2 did not change the EC50 value of 5‐HT in stimulating current, but reduced the maximum effect.

The CB1 receptor ligand [3H]‐SR141716A and the CB1/CB2 receptor ligand [3H]‐CP55940 did not specifically bind to parental HEK293 cells. In competition experiments on membranes of HEK293 cells transfected with the h5‐HT3A receptor cDNA, WIN55,212‐2, CP55940, anandamide and SR141716A did not affect [3H]‐GR65630 binding, but 5‐HT caused a concentration dependent‐inhibition.

In conclusion, cannabinoids stereoselectively inhibit currents through recombinant h5‐HT3A receptors independently of cannabinoid receptors. Probably the cannabinoids act allosterically at a modulatory site of the h5‐HT3A receptor. Thus the functional state of the receptor can be controlled by the endogenous ligand anandamide. This site is a potential target for new analgesic and antiemetic drugs.

British Journal of Pharmacology (2002) 137, 589–596. doi:10.1038/sj.bjp.0704829
A possible role of neurotensin in NANC relaxation of longitudinal muscle of the jejunum and ileum of Wistar rats
Authors: Yamaji Michiru , Ohta Mayuko , Yamazaki Yasuko , Fujinami Kaori , Fujita Akikazu , Takeuchi Tadayoshi , Hata Fumiaki , Takewaki Tadashi
Published: October 2002

The mediators of nonadrenergic, noncholinergic (NANC) relaxation in longitudinal muscle of the jejunum and ileum of Wistar rats were examined in vitro.

Treatment of the jejunal and ileal segments with α‐chymotrypsin resulted in decreases in the NANC relaxations induced by electrical field stimulation (EFS) by about one half.

The NANC relaxations were also decreased by about one half after the segments had been desensitized to neurotensin. A neurotensin receptor antagonist, SR48692 (10 μM) inhibited the NANC relaxation by 56 and 34% in the jejunal and ileal segments, respectively.

An inhibitor of small conductance Ca2+‐activated K+ channel (SK channel), apamin (100 nM) also inhibited the NANC relaxation by 83 and 63%, respectively. Exogenous neurotensin‐induced relaxations of the two segments were abolished by apamin.

In the ileal segments, NG‐nitro‐L‐arginine (L‐NOARG, 100 μM), inhibited the NANC relaxation by 43%. L‐NOARG, but not apamin, further inhibited the relaxation which persisted after the desensitization to neurotensin. Apamin with SR48692 inhibited the relaxation only to the same extent as apamin alone.

EFS induced inhibitory junction potentials (i.j.ps) in the longitudinal muscle cells of the ileum. I.j.ps consisted of a rapid and a delayed phase. L‐NOARG significantly inhibited only the delayed phase.

EFS induced only a rapid i.j.ps in the jejunum. SR48692 and apamin inhibited the i.j.ps.

These findings suggest that neurotensin and unknown substance(s) mediate NANC relaxation via SK channels in the jejunum of Wistar rats, and that neurotensin via SK channels and nitric oxide not via SK channels separately mediate the relaxation in the ileum.

British Journal of Pharmacology (2002) 137, 629–636. doi:10.1038/sj.bjp.0704914
Pharmacological approach towards the development of indolequinone bioreductive drugs based on the clinically inactive agent EO9
Authors: Loadman P M , Bibby M C , Phillips R M
Published: October 2002

The bioreductive drug EO9 (3‐hydroxy‐5‐aziridinyl‐1‐methyl‐2[indole‐4,7‐dione]–prop‐β‐en‐α‐ol) has good pharmacodynamic properties in vitro, modest anti‐tumour activity in experimental tumour models, but failed to show activity in clinical trials. Understanding the reasons for its poor efficacy in vivo is important in terms of progressing second generation analogues into the clinic.

In two human tumour xenografts, direct intra‐tumoural injection resulted in improved anti‐tumour activity compared with intravenous administration suggesting that drug delivery to tumours is suboptimal. Compared with Mitomycin C (MMC) and the experimental agent MeDZQ, EO9 was rapidly cleared from the systemic circulation (t1/2=1.8 min) whereas MMC and MeDZQ had significantly increased plasma t1/2 values (14 and 22 min respectively). These three compounds demonstrated similar pharmacodynamic properties in terms of potency towards the NQO1 (NAD(P)H:Quinone oxidoreductase) rich H460 cell line in vitro but differed significantly in their in vivo activity with growth delays of 17.7, 4.5 and 1.0 days for MMC, MeDZQ and EO9 respectively. EO9 was rapidly metabolized by red blood cells in vitro (t1/2=14.5 min) which must contribute to its rapid pharmacokinetic elimination in vivo whereas MMC and MeDZQ were metabolized at comparatively slower rates (t1/2>120 min and 77.0 min respectively).

In conclusion, the development of second generation EO9 analogues should address the issue of drug delivery and analysis of drug metabolism by murine whole blood in vitro could be utilized as a preliminary screen to identify lead compounds that are likely to have improved pharmacokinetic profiles in vivo.

British Journal of Pharmacology (2002) 137, 701–709. doi:10.1038/sj.bjp.0704916
The impairment of endothelium‐dependent arterial relaxation by7‐ketocholesterol is associated with an early activation of protein kinase C
Authors: Deckert Valérie , Duverneuil Linda , Poupon Sandrine , Monier Serge , Le Guern Naig , Lizard Gérard , Masson David , Lagrost Laurent
Published: October 2002

Among components of oxidized low density lipoproteins, cholesterol derivatives oxidized in position 7 inhibit endothelium‐dependent arterial relaxation by decreasing the release of the main endothelium‐derived relaxing factor, nitric oxide (NO). The aim of the present study was to bring new insights into the molecular mechanism by which 7‐ketocholesterol can block the endothelium‐dependent arterial relaxation.

Superoxide dismutase did not prevent the inhibitory effect of 7‐ketocholesterol on endothelium‐dependent relaxation, and consistent observations were made whether superoxide dismutase was conjugated or not to polyethylene glycol. In addition, neither glutathione supplementation, nor oxypurinol, i.e. a xanthine oxidase inhibitor could reverse the effect of 7‐ketocholesterol, indicating that NO was not inactivated by superoxide anion.

A direct alteration of the activity of the calcium‐dependent NO synthase could also be ruled out, since identical relaxing effects of the calcium ionophore A23187 were observed whether arterial rings were treated or not with 7‐ketocholesterol.

Whereas the above observations come in support of an early, inhibitory action of 7‐ketocholesterol, the specific blockade of one given subtype of membrane receptors could be discarded, and similar inhibitions were observed when either muscarinic or purinergic receptors were stimulated.

Finally, the blockade of protein kinase C activity by chelerythrine arose as the sole relevant tool in preventing the effect of 7‐ketocholesterol on the endothelium‐dependent relaxation of rabbit aortic rings. In addition, complementary studies on cultured bovine aortic endothelial cells came in direct support of the ability of 7‐ketocholesterol to activate PKC.

In conclusion, 7‐ketocholesterol that is present in human hypercholesterolaemic plasma, in atherosclerotic arteries, and in many processed foods can block the release of NO by vascular endothelial cells through its ability to activate PKC.

British Journal of Pharmacology (2002) 137, 655–662. doi:10.1038/sj.bjp.0704920
Modeling the Internet's large-scale topology
Authors: Yook Soon-Hyung , Jeong Hawoong , Barabási Albert-László
Published: October 2002

Network generators that capture the Internet's large-scale topology are crucial for the development of efficient routing protocols and modeling Internet traffic. Our ability to design realistic generators is limited by the incomplete understanding of the fundamental driving forces that affect the Internet's evolution. By combining several independent databases capturing the time evolution, topology, and physical layout of the Internet, we identify the universal mechanisms that shape the Internet's router and autonomous system level topology. We find that the physical layout of nodes form a fractal set, determined by population density patterns around the globe. The placement of links is driven by competition between preferential attachment and linear distance dependence, a marked departure from the currently used exponential laws. The universal parameters that we extract significantly restrict the class of potentially correct Internet models and indicate that the networks created by all available topology generators are fundamentally different from the current Internet.
Interaction of dihydrofolate reductase with methotrexate: Ensemble and single-molecule kinetics
Authors: Rajagopalan P. T. Ravi , Zhang Zhiquan , McCourt Lynn , Dwyer Mary , Benkovic Stephen J. , Hammes Gordon G.
Published: October 2002

The thermodynamics and kinetics of the interaction of dihydrofolate reductase (DHFR) with methotrexate have been studied by using fluorescence, stopped-flow, and single-molecule methods. DHFR was modified to permit the covalent addition of a fluorescent molecule, Alexa 488, and a biotin at the N terminus of the molecule. The fluorescent molecule was placed on a protein loop that closes over methotrexate when binding occurs, thus causing a quenching of the fluorescence. The biotin was used to attach the enzyme in an active form to a glass surface for single-molecule studies. The equilibrium dissociation constant for the binding of methotrexate to the enzyme is 9.5 nM. The stopped-flow studies revealed that methotrexate binds to two different conformations of the enzyme, and the association and dissociation rate constants were determined. The single-molecule investigation revealed a conformational change in the enzyme-methotrexate complex that was not observed in the stopped-flow studies. The ensemble averaged rate constants for this conformation change in both directions is about 2–4 s
−1
and is attributed to the opening and closing of the enzyme loop over the bound methotrexate. Thus the mechanism of methotrexate binding to DHFR involves multiple steps and protein conformational changes.
Natural alleles at a tomato fruit size quantitative trait locus differ by heterochronic regulatory mutations
Authors: Cong Bin , Liu Jiping , Tanksley Steven D.
Published: October 2002

fw2.2is a major quantitative trait locus that accounts for as much as 30% of the difference in fruit size between wild and cultivated tomatoes. Evidence thus far indicates thatfw2.2alleles modulate fruit size through changes in gene regulation rather than in the FW2.2 protein itself. To investigate the nature of these regulatory changes and the manner in which they may affect fruit size, a pair of nearly isogenic lines has been subjected to detailed developmental, transcriptional, mitotic, andin situhybridization studies. The results indicate that the large- and small-fruited alleles offw2.2differ in peak transcript levels by ≈1 week. Moreover, this difference in timing of expression is associated with concomitant changes in mitotic activity in the early stage of fruit development. The changes in timing of gene expression (heterochronic allelic variation), combined with overall differences in total transcript levels, are sufficient to account for a large portion phenotypic differences in fruit weight associated with the two alleles.
Expanding pyrimidine diphosphosugar libraries via structure-based nucleotidylyltransferase engineering
Authors: Barton William A. , Biggins John B. , Jiang Jiqing , Thorson Jon S. , Nikolov Dimitar B.
Published: October 2002

In vitro
“glycorandomization” is a chemoenzymatic approach for generating diverse libraries of glycosylated biomolecules based on natural product scaffolds. This technology makes use of engineered variants of specific enzymes affecting metabolite glycosylation, particularly nucleotidylyltransferases and glycosyltransferases. To expand the repertoire of UDP/dTDP sugars readily available for glycorandomization, we now report a structure-based engineering approach to increase the diversity of α-
d
-hexopyranosyl phosphates accepted by
Salmonella enterica
LT2 α-
d
-glucopyranosyl phosphate thymidylyltransferase (E
p
). This article highlights the design rationale, determined substrate specificity, and structural elucidation of three “designed” mutations, illustrating both the success and unexpected outcomes from this type of approach. In addition, a single amino acid substitution in the substrate-binding pocket (L89T) was found to significantly increase the set of α-
d
-hexopyranosyl phosphates accepted by E
p
to include α-
d
-
allo
-, α-
d
-
altro
-, and α-
d
-
talo
pyranosyl phosphate. In aggregate, our results provide valuable blueprints for altering nucleotidylyltransferase specificity by design, which is the first step toward
in vitro
glycorandomization.
Small heat-shock proteins regulate membrane lipid polymorphism
Authors: Tsvetkova Nelly M. , Horváth Ibolya , Török Zsolt , Wolkers Willem F. , Balogi Zsolt , Shigapova Natalia , Crowe Lois M. , Tablin Fern , Vierling Elizabeth , Crowe John H. , Vígh László
Published: October 2002

Thermal stress in living cells produces multiple changes that ultimately affect membrane structure and function. We report that two members of the family of small heat-shock proteins (sHsp) (α-crystallin and
Synechocystis
HSP17) have stabilizing effects on model membranes formed of synthetic and cyanobacterial lipids. In anionic membranes of dimyristoylphosphatidylglycerol and dimyristoylphosphatidylserine, both HSP17 and α-crystallin strongly stabilize the liquid-crystalline state. Evidence from infrared spectroscopy indicates that lipid/sHsp interactions are mediated by the polar headgroup region and that the proteins strongly affect the hydrophobic core. In membranes composed of the nonbilayer lipid dielaidoylphosphatidylethanolamine, both HSP17 and α-crystallin inhibit the formation of inverted hexagonal structure and stabilize the bilayer liquid-crystalline state, suggesting that sHsps can modulate membrane lipid polymorphism. In membranes composed of monogalactosyldiacylglycerol and phosphatidylglycerol (both enriched with unsaturated fatty acids) isolated from
Synechocystis
thylakoids, HSP17 and α-crystallin increase the molecular order in the fluid-like state. The data show that the nature of sHsp/membrane interactions depends on the lipid composition and extent of lipid unsaturation, and that sHsps can regulate membrane fluidity. We infer from these results that the association between sHsps and membranes may constitute a general mechanism that preserves membrane integrity during thermal fluctuations.
Subunit rotation of ATP synthase embedded in membranes:
a
or β subunit rotation relative to the
c
subunit ring
Authors: Nishio Kazuaki , Iwamoto-Kihara Atsuko , Yamamoto Akitsugu , Wada Yoh , Futai Masamitsu
Published: October 2002

ATP synthase F
o
F
1
(α
3
β
3
γδɛ
ab
2
c
10–14
) couples an electrochemical proton gradient and a chemical reaction through the rotation of its subunit assembly. In this study, we engineered F
o
F
1
to examine the rotation of the catalytic F
1
β or membrane sector F
o
a
subunit when the F
o
c
subunit ring was immobilized; a biotin-tag was introduced onto the β or
a
subunit, and a His-tag onto the
c
subunit ring. Membrane fragments were obtained from
Escherichia coli
cells carrying the recombinant plasmid for the engineered F
o
F
1
and were immobilized on a glass surface. An actin filament connected to the β or
a
subunit rotated counterclockwise on the addition of ATP, and generated essentially the same torque as one connected to the
c
ring of F
o
F
1
immobilized through a His-tag linked to the α or β subunit. These results established that the γɛ
c
10–14
and α
3
β
3
δ
ab
2
complexes are mechanical units of the membrane-embedded enzyme involved in rotational catalysis.
Tau filament formation and associative memory deficit in aged mice expressing mutant (R406W) human tau
Authors: Tatebayashi Yoshitaka , Miyasaka Tomohiro , Chui De-Hua , Akagi Takumi , Mishima Ken-ichi , Iwasaki Katsunori , Fujiwara Michihiro , Tanemura Kentaro , Murayama Miyuki , Ishiguro Koichi , Planel Emmanuel , Sato Shinji , Hashikawa Tsutomu , Takashima Akihiko
Published: October 2002

The R406W tau mutation found in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) causes a hereditary tauopathy clinically resembling Alzheimer's disease. Expression of modest levels of the longest human tau isoform with this mutation under the control of the α-calcium–calmodulin-dependent kinase-II promoter in transgenic (Tg) mice resulted in the development of congophilic hyperphosphorylated tau inclusions in forebrain neurons. These inclusions appeared as early as 18 months of age. As with human cases, tau inclusions were composed of both mutant and endogenous wild-type tau, and were associated with microtubule disruption and flame-shaped transformations of the affected neurons. Straight tau filaments were recovered from Sarkosyl-insoluble fractions from only the aged Tg brains. Behaviorally, aged Tg mice had associative memory impairment without obvious sensorimotor deficits. Therefore, these mice that exhibit a phenotype mimicking R406W FTDP-17 provide an animal model for investigating the adverse properties associated with this mutation, which might potentially recapitulate some etiological events in Alzheimer's disease.
Yeast Tdp1 and Rad1-Rad10 function as redundant pathways for repairing Top1 replicative damage
Authors: Vance John R. , Wilson Thomas E.
Published: October 2002

When a replication fork collides with a DNA topoisomerase I (Top1) cleavage complex, the covalently bound enzyme must be removed from the DNA 3′ end before recombination-dependent replication restart. Here we report that the tyrosyl-DNA phosphodiesterase Tdp1 and the structure-specific endonuclease Rad1-Rad10 function as primary alternative pathways of Top1 repair in
Saccharomyces cerevisiae
. Thus,
tdp1 rad1
cells (including the catalytic point mutant
rad1
-D869A) not only are highly sensitive to the Top1 poison camptothecin but also exhibit a
TOP1
-dependent growth delay. Extensive genetic analysis revealed that both Tdp1 and Rad1-Rad10 repair proceed through recombination that equally depends on
RAD52
,
RAD51
, and
RAD50
. The Rad1-Rad10 pathway further particularly depends on
RAD59
and
SRS2
but is independent of other nucleotide excision repair genes. Although this pattern is consistent with Rad1-Rad10 removing Top1 in a manner similar to its removal of nonhomologous tails during gene conversion, these differ in that Top1 removal does not require Msh2-Msh3. Finally, we show that yeast lacking the Rad1-Rad10-related proteins Mus81-Mms4 display a unique pattern of camptothecin sensitivity and suggest a concerted model for the action of these endonucleases.