bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased Frequency of Cytomegalovirus (CMV)-Specific CD4+T Lymphocytes in Simian Immunodeficiency Virus-Infected Rhesus Macaques: Inverse Relationship with CMV Viremia
Authors: Kaur Amitinder , Hale Corrina L. , Noren Bradley , Kassis Nadine , Simon Meredith A. , Johnson R. Paul 
Published: July 2002

ABSTRACTThe frequency of cytomegalovirus (CMV)-specific CD4+T lymphocytes was determined in CMV-seropositive rhesus macaques with or without simian immunodeficiency virus (SIV) infection by using the sensitive assays of intracellular cytokine staining and gamma interferon ELISPOT. Both techniques yielded 3- to 1,000-fold-higher frequencies of CMV-specific CD4+T lymphocytes than traditional proliferative limiting dilution assays. The median frequency of CMV-specific CD4+T lymphocytes in 23 CMV-seropositive SIV-negative macaques was 0.63% (range, 0.16 to 5.8%). The majority of CMV-specific CD4+T lymphocytes were CD95posand CD27lobut expressed variable levels of CD45RA. A significant reduction (P< 0.05) in the frequency of CMV-specific CD4+T lymphocytes was observed in pathogenic SIV-infected macaques but not in macaques infected with live attenuated strains of SIV. CMV-specific CD4+T lymphocytes were not detected in six of nine pathogenic SIV-infected rhesus macaques. CMV DNA was detected in the plasma of four of six of these macaques but in no animal with detectable CMV-specific CD4+T lymphocytes. In pathogenic SIV-infected macaques, loss of CMV-specific CD4+T lymphocytes was not predicted by the severity of CD4+T lymphocytopenia. Neither was it predicted by the pre-SIV infection frequencies of CD45RAnegor CCR5posCMV-specific CD4+T lymphocytes. However, the magnitude of activation, as evidenced by the intensity of CD40L expression on CMV-specific CD4+T lymphocytes pre-SIV infection, was three- to sevenfold greater in the two macaques that subsequently lost these cells after SIV infection than in the two macaques that retained CMV-specific CD4+T lymphocytes post-SIV infection. Future longitudinal studies with these techniques will facilitate the study of CMV pathogenesis in AIDS.
Human Immunodeficiency Virus Type 1 Vpr Protein Does Not Modulate Surface Expression of the CD4 Receptor
Authors: Argañaraz Enrique , Cortés María José , Leibel Sydney , Lama Juan 
Published: July 2002

ABSTRACT

The CD4 receptor is required for the entry of human immunodeficiency virus (HIV) into target cells. It has long been known that Nef, Env, and Vpu participate in the removal of the viral receptor from the cell surface. Recently, it has been proposed that the HIV type 1 (HIV-1) Vpr protein may also play a role in the downmodulation of CD4 from the surfaces of infected cells (L. Conti, B. Varano, M. C. Gauzzi, P. Matarrese, M. Federico, W. Malorani, F. Belardelli, and S. Gessani, J. Virol. 74:10207-10211, 2000). To investigate the possible role of Vpr in the downregulation of the viral receptor Vpr alleles from HIV-1 and simian immunodeficiency virus were transiently expressed in transformed T cells and in 293T fibroblasts, and their ability to modulate surface CD4 was evaluated. All Vpr alleles efficiently arrested cells in the G
2
stage of the cell cycle. However, none of the tested Vpr proteins altered the expression of CD4 on the cell surface. In comparison, HIV-1 Nef efficiently downmodulated surface CD4 in all the experimental settings. Transformed T cells and primary lymphocytes were challenged with wild-type, Nef-defective, and Vpr-defective viruses. A significant reduction in the HIV-induced downmodulation of surface CD4 was observed in viruses lacking Nef. However, Vpr-deletion-containing viruses showed no defect in their ability to remove CD4 from the surfaces of infected cells. Our results indicate that Vpr does not play a role in the HIV-induced downmodulation of the CD4 receptor.
The Conformation of the Mature Dimeric Human Immunodeficiency Virus Type 1 RNA Genome Requires Packaging of Pol Protein
Authors: Shehu-Xhilaga M. , Hill M. , Marshall J. A. , Kappes J. , Crowe S. M. , Mak J. 
Published: July 2002

ABSTRACT

The packaging of a mature dimeric RNA genome is an essential step in human immunodeficiency virus type 1 (HIV-1) replication. We have previously shown that overexpression of a protease (PR)-inactive HIV-1 Gag-Pro-Pol precursor protein generates noninfectious virions that contain mainly monomeric RNA (M. Shehu-Xhilaga, S. M. Crowe, and J. Mak, J. Virol. 75:1834-1841, 2001). To further define the contribution of HIV-1 Gag and Gag-Pro-Pol to RNA maturation, we analyzed virion RNA dimers derived from Gag particles in the absence of Gag-Pro-Pol. Compared to wild-type (WT) dimeric RNAs, these RNA dimers have altered mobility and low stability under electrophoresis conditions, suggesting that the HIV-1 Gag precursor protein alone is not sufficient to stabilize the dimeric virion RNA structure. The inclusion of an active viral PR, without reverse transcriptase (RT) and integrase (IN), rescued the stability of the virion RNA dimers in the Gag particles but did not restore the mobility of the RNAs, suggesting that RT and IN are also required for virion RNA dimer maturation. Thin-section electron microscopy showed that viral particles deficient in RT and IN contain empty cone-shaped cores. The abnormal core structure indicates a requirement for Gag-Pro-Pol packaging during core maturation. Supplementing viral particles with either RT or IN via Vpr-RT or Vpr-IN alone did not correct the conformation of the dimer RNAs, whereas expression of both RT and IN in
trans
as a Vpr-RT-IN fusion restored RNA dimer conformation to that of the WT virus and also restored the electron-dense, cone-shaped virion core characteristic of WT virus. Our data suggest a role for RT-IN in RNA dimer conformation and the formation of the electron-dense viral core.
Pathogenesis of Avian Influenza A (H5N1) Viruses in Ferrets
Authors: Zitzow Lois A. , Rowe Thomas , Morken Timothy , Shieh Wun-Ju , Zaki Sherif , Katz Jacqueline M. 
Published: July 2002

ABSTRACTHighly pathogenic avian influenza A H5N1 viruses caused outbreaks of disease in domestic poultry and humans in Hong Kong in 1997. Direct transmission of the H5N1 viruses from birds to humans resulted in 18 documented cases of respiratory illness, including six deaths. Here we evaluated two of the avian H5N1 viruses isolated from humans for their ability to replicate and cause disease in outbred ferrets. A/Hong Kong/483/97 virus was isolated from a fatal case and was highly pathogenic in the BALB/c mouse model, whereas A/Hong Kong/486/97 virus was isolated from a case with mild illness and exhibited a low-pathogenicity phenotype in mice. Ferrets infected intranasally with 10750% egg infectious doses (EID50) of either H5N1 virus exhibited severe lethargy, fever, weight loss, transient lymphopenia, and replication in the upper and lower respiratory tract, as well as multiple systemic organs, including the brain. Gastrointestinal symptoms were seen in some animals. In contrast, weight loss and severe lethargy were not noted in ferrets infected with 107EID50of two recent human H3N2 viruses, although these viruses were also isolated from the brains, but not other extrapulmonary organs, of infected animals. The results demonstrate that both H5N1 viruses were highly virulent in the outbred ferret model, unlike the differential pathogenicity documented in inbred BALB/c mice. We propose the ferret as an alternative model system for the study of these highly pathogenic avian viruses.
Balancing the risk of injury to gymnasts: how effective are the counter measures?
Authors: Daly R M , Bass S L , Finch C F 
Published: July 2002

Background—To minimise injury risk and maximise gymnastics performance, coaches, parents, and health professionals working with young gymnasts need to understand and practise safe gymnastics.Aims—To (a) identify the various injury counter measures specific to gymnastics, (b) critically review the literature describing each injury prevention measure, and (c) assess, using available risk factor and injury data, the weight of evidence to support each of these counter measures. Specific recommendations for further research and implementation strategies to prevent injury and improve safety are also given.Methods—The relevant literature was identified through the use of Medline (1966 to May 1998) and SPORT Discus (1975 to May 1998) searches, hand searching of journals and reference lists, and discussions with key Australian gymnastics organisations.Results—The key gymnastics injury counter measures identified in this review include coaching (physical preparation, education, spotting, and performance technique), equipment, and the health support system (medical screening, treatment, and rehabilitation). Categorisation of the type of evidence for the effectiveness of each of these counter measures in preventing injury showed that most of it is based on informal opinion/anecdotal evidence, uncontrolled data based studies, and several prospective epidemiological studies. There is no evidence from formally controlled trials or specific evaluation studies of counter measures for gymnastics.Conclusions—Although gymnastics is a sport associated with young participants and frequent high volume, high impact training, there is a paucity of information on injury risk factors and the effectiveness of injury practices. Further controlled trials are needed to examine the extent to which injury prevention counter measures can prevent or reduce the occurrence of injury and re-injury. Particular attention should be devoted to improving training facilities, the design and testing of apparatus and personal equipment used by gymnasts, and coaching and the role of spotting in preventing injury.
Association between job strain and prevalence of hypertension: a cross sectional analysis in a Japanese working population with a wide range of occupations: the Jichi Medical School cohort study
Authors: Tsutsumi A , Kayaba K , Tsutsumi K , Igarashi M 
Published: July 2002

OBJECTIVESTo explore the association between the prevalence of hypertension in a Japanese working population and job strain (a combination of low control over work and high psychological demands), and to estimate this association in different sociodemographic strata.METHODSFrom a multicentre community based cohort study of Japanese people, sex specific cross sectional analyses were performed on 3187 men and 3400 women under 65 years of age, all of whom were actively engaged in various occupations throughout Japan. The baseline period was 1992–4. The association between job characteristics—measured with a Japanese version of the Karasek demand-control questionnaire—and the prevalence of hypertension defined by blood pressure and from clinical diagnoses were examined. Adjustments were made for possible confounders. The analyses were repeated for stratified categories of occupational class, educational attainment, and age group.RESULTSIn men, the level of job strain (the ratio of psychological job demands to job control) correlated with the prevalence of hypertension. In a multiple logistic regression model, job strain was significantly related to hypertension (odds ratio 1.18; 95% confidence interval 1.05 to 1.32), after adjustment for age, employment (white collarvblue collar), marital status, family history of hypertension, cigarette smoking, alcohol intake, physical activity, and body mass index. The stratified analyses showed significant excess risks in the subordinate groups compared with managers, blue collar workers, less educated workers, and the older age groups. This association was not significant in women. Multiple linear regression analyses, with systolic and diastolic blood pressures as dependent variables, did not show any significant association.CONCLUSIONSThe findings provided limited proof that job strain is related to hypertension in Japanese working men. Older men in a lower social class may be more vulnerable to the hypertensive effects of job strain.
Interrelations of risk factors and low back pain in scaffolders
Authors: Elders L A M , Burdorf A 
Published: July 2002

OBJECTIVESTo assess with a cross sectional study the interrelations between physical, psychosocial, and individual risk factors and different end points of low back pain.METHODSIn total, 229 scaffolders and 59 supervisors completed a questionnaire about manual handling of materials, awkward back posture, strenuous arm position, perceived exertion, psychosocial load, need for recovery, and general health. Physical load at the worksite was also measured with many frequent observations. Interrelations between risk factors and their relation with four end points of low back pain were investigated.RESULTSInterrelations were strong among self reported determinants of physical load but showed an inverted trend for both age and total working experience, which could indicate the presence of a healthy worker effect. Weak relations existed between variables of psychosocial and physical load. The multivariate analyses showed a significant relation between high manual handling of materials, moderate perceived general health, high job demands, and low back pain in the past 12 months. Chronic low back pain was significantly correlated with high perceived exertion and moderate perceived general health. Severe low back pain was significantly correlated with awkward back postures, high need for recovery, and high job demands. Finally, low back pain with perceived disability was significantly related to strenuous shoulder positions and moderate perceived general health. All end points of low back pain were consistently associated with physical load whereas psychosocial aspects showed a more diverse pattern.CONCLUSIONSThe findings of this study suggest that work related risk factors may vary according to different definitions of low back pain. Distinct patterns of risk factors might enhance different expressions of it. Scaffolders are a group at high risk of developing persistent forms of low back pain.
Pregnancy in systemic lupus erythematosus
Authors: Mok C C , Wong R W S 
Published: July 2002

Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease that predominantly affects women of reproductive age. Pregnancy and its outcome is a major concern to most SLE patients. Queries regarding the risk of disease flares during pregnancy, chance of fetal loss, and the safety of various drugs are often raised. With the improvement in the understanding of the pathogenesis of SLE and the judicious use of immunosuppressive drugs, better disease control can now be achieved and SLE patients should not be deprived of the opportunity for bearing children. Prepregnancy counselling and close collaboration with other specialists such as the obstetricians and the perinatologists is essential in optimising the maternal and fetal outcome in lupus pregnancies. In this review, important issues regarding the fertility rate, optimal timing of conception, risk of disease flares during lupus pregnancy, pregnancy course, fetal outcome, safety of various drugs used for disease control during pregnancy and lactation, and contraceptive advice are discussed.
Evolution of an inguinal hernia surgery practice
Authors: Mokete M , Earnshaw J J 
Published: July 2002

Abstract

BACKGROUND
Inguinal hernia surgery has undergone numerous advances in the last few years. This study analysed the changes in the practice of one surgeon in a district general hospital over a seven year interval. The effect of changing from Bassini to Lichtenstein repair in 1994 was evaluated.

METHODS
The study involved two parts: first a search of a computerised database of inguinal hernia procedures, and second, postal audits of men who had an inguinal hernia repair in 1993 and 1994 with outpatient follow up for those with a possible recurrence.

RESULTS
A total of 1037 hernias were repaired over the seven years. There was an increase in the proportion of day cases from 18% to 70% and the number of operations performed under local anaesthetic rose from 1% to 45%. The postal audits had response rates of 79% (1993) and 66% (1994). Some 5/98 (5%) recurrent hernias were identified from the 1993 (Bassini) patients compared with 1/67 (1.5%) from the 1994 (Lichtenstein) cohort.

CONCLUSION
Lichtenstein hernia repair can be performed safely as a day case using local anaesthetic in the majority of patients and appears to have a lower recurrence rate than Bassini repair.
Is there a dissociative process in sleepwalking and night terrors?
Authors: Hartman D , Crisp A H , Sedgwick P , Borrow S 
Published: July 2002

Abstract
The enduring and contentious hypothesis that sleepwalking and night terrors are symptomatic of a protective dissociative mechanism is examined. This is mobilised when intolerable impulses, feelings and memories escape, within sleep, the diminished control of mental defence mechanisms. They then erupt but in a limited motoric or affective form with restricted awareness and subsequent amnesia for the event. It has also been suggested that such processes are more likely when the patient has a history of major psychological trauma. In a group of 22 adult patients, referred to a tertiary sleep disorders service with possible sleepwalking/night terrors, diagnosis was confirmed both clinically and polysomnographically, and only six patients had a history of such trauma. More commonly these described sleepwalking/night terrors are associated with vivid dream-like experiences or behaviour related to flight from attack. Two such cases, suggestive of a dissociative process, are described in more detail.
The results of this study are presented largely on account of the negative findings. Scores on the dissociation questionnaire (DIS-Q) were normal, although generally higher in the small “trauma” subgroup. These were similar to scores characterising individuals with post-traumatic stress disorder. This “trauma” group also scored particularly highly on the anxiety,phobic, and depression scales of the Crown-Crisp experiential index. In contrast the “no trauma” group scored more specifically highly on the anxiety scale, along with major trends to high depressionand hysteria scale scores. Two cases are presented which illustrate exceptional occurrence of later onset of sleepwalking/night terrors with accompanying post-traumatic symptoms during wakefulness. It is concluded that a history of major psychological trauma exists in only a minority of adult patients presenting with sleepwalking/night terror syndrome. In this subgroup trauma appears to dictate the subsequent content of the attacks. However, the symptoms express themselves within the form of the sleepwalking/night terror syndrome rather than as rapid eye movement sleep related nightmares. The main group of subjects with the syndrome and with no history of major psychological trauma show no clinical or DIS-Q evidence of dissociation during wakefulness. The proposition that, within the character structure of this group, the mechanism still operates but exclusively within sleep remains a possibility.
Delayed reactivation of haloperidol induced photosensitive dermatitis by methotrexate
Authors: Thami G P , Kaur S , Kanwar A J 
Published: July 2002

Abstract
A man whose psoriasis was well controlled on methotrexate treatment developed pellagra-like photosensitive dermatitis when he started taking haloperidol. Reactivation of his dermatitis was observed with methotrexate as a recall photosensitivity phenomenon. This false photosensitivity reaction of methotrexate is an important but rarely encountered adverse effect. A possible interaction between methotrexate and haloperidol is emphasised.
ON SINGULARITIES OF ℳℙ3 (c1, c2)
Authors: ANCONA VINCENZO , OTTAVIANI GIORGIO 
Published: July 2002

Let ℳℙ3(c1,c2) be the moduli space of stable rank-2 vector bundles on ℙ3 with Chern classes c1, c2. We prove the following results: (1) Let k, β, γ be three integers such that k > 0, 0 ≤ β < γ, γ ≥ 2, kγ - (k + 1)β > 0; then the moduli space ℳℙ3(0, kγ2 - (k + 1)β2) is singular (the case k = 2, β = 0 was previously proved by M. Maggesi). (2) Let k, β, γ be three integers, with β and γ odd, such that k > 0, 0 < β < γ, γ ≥ 5, kγ - (k + 1)β + 1 > 0; then the moduli space ℳℙ3(-1,k(γ/2)2 - (k + 1)(β/2)2) + 1/4) is singular. In particular ℳℙ3(0,5), ℳℙ3(-1,6) are singular.
WEAKEST SPECIFUNCTIONS FOR BSP
Authors: CHEN YIFENG , SANDERS J. W. 
Published: July 2002

This paper introduces a calculus of weakest specification for supporting reuse of established components in deriving a design (in the sense of formal methods). The weakest specifunction generalizes the notions of weakest pre-specification and weakest parallel environment; but instead of calculating the weakest required component of a target specification, it calculates the weakest specification function whose value refines the target when applied to an established component. In particular it overcomes the restriction of those other calculi to taking merely one required component at a time.The theory of specifunctions is applied to a new weakest-design calculus in the context of BSP. The calculus is based on the par-seq specifunction which involves two required components: it places one established component in parallel with one required component and the result in sequence with another required component to meet a given specification. A calculus is provided for the par-seq specifunction and it is applied to the derivation of a distributed BSP algorithm for greatest common divisor.
Local management of a global resource in a communication network
Authors: Afek Yehuda , Awerbuch Baruch , Plotkin Serge , Saks Michael 
Published: July 2002

This paper introduces a new distributed data object called Resource Controller that provides an abstraction for managing the consumption of a global resource in a distributed system. Examples of resources that may be managed by such an object include; number of messages sent, number of nodes participating in the protocol, and total CPU time consumed.The Resource Controller object is accessed through a procedure that can be invoked at any node in the network. Before consuming a unit of resource at some node, the controlled algorithm should invoke the procedure at this node, requesting a permit or a rejection.The key characteristics of the Resource Controller object are the constraints that it imposes on the global resource consumption. An (M, W)-Controller guarantees that the total number of permits granted is at mostM; it also ensures that, if a request is rejected, then at leastM—Wpermits are eventually granted, even if no more requests are made after the rejected one.In this paper, we describe several message and space-efficient implementations of the Resource Controller object. In particular, we present an (M, W)-Controller whose message complexity isO(nlog2nlog(M/(W+ 1)) wherenis the total number of nodes. This is in contrast to theO(nM)message complexity of a fully centralized controller which maintains a global counter of the number of granted permits at some distinguished node and relays all the requests to the node.
System R
Authors: Astrahan M. M. , Blasgen M. W. , Chamberlin D. D. , Eswaran K. P. , Gray J. N. , Griffiths P. P. , King W. F. , Lorie R. A. , McJones P. R. , Mehl J. W. , Putzolu G. R. , Traiger I. L. , Wade B. W. , Watson V. 
Published: July 2002

System R is a database management system which provides a high level relational data interface. The systems provides a high level of data independence by isolating the end user as much as possible from underlying storage structures. The system permits definition of a variety of relational views on common underlying data. Data control features are provided, including authorization, integrity assertions, triggered transactions, a logging and recovery subsystem, and facilities for maintaining data consistency in a shared-update environment.
This paper contains a description of the overall architecture and design of the system. At the present time the system is being implemented and the design evaluated. We emphasize that System R is a vehicle for research in database architecture, and is not planned as a product.