bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drug use patterns and mental health of regular amphetamine users during a reported ‘heroin drought’
Authors: Baker Amanda , Lee Nicole K. , Claire Melissa , Lewin Terry J. , Grant Tanya , Pohlman Sonja , Saunders John B. , Kay‐Lambkin Frances , Constable Paul , Jenner Linda , Carr Vaughan J. 
Published: June 2004

ABSTRACTAims  The present study extends the findings of a pilot study conducted among regular amphetamine users in Newcastle, NSW, in 1998. It compares key features between current participants in a state capital city (Brisbane) and a regional city (Newcastle) and between the 1998 and current Newcastle sample.Design  Cross‐sectional survey.Setting  Brisbane and Newcastle, Australia.Participants  The survey was conducted among 214 regular amphetamine users within the context of a randomized controlled trial of brief interventions for amphetamine use.Measurements  Demographic characteristics, past and present alcohol and other drug use and mental health, treatment, amphetamine‐related harms and severity of dependence.Findings  The main findings were as follows: (i) the rate of mental health problems was high among regular amphetamine users and these problems commonly emerged after commencement of regular amphetamine use; (ii) there were regional differences in drug use with greater accessibility to a wider range of drugs in a state capital city and greater levels of injecting risk‐taking behaviour outside the capital city environment; and (iii) there was a significant increase in level of amphetamine use and percentage of alcohol users, a trend for a higher level of amphetamine dependence and a significant reduction in the percentage of people using heroin and benzodiazepines among the 2002 Newcastle cohort compared to the 1998 cohort.Conclusions  Further longitudinal research is needed to elucidate transitions from one drug type to another and from recreational to injecting and regular use and the relationship between drug use and mental health in prospective studies among users.Implications  Intervention research should evaluate the effectiveness of interventions aimed at: preventing transition to injecting and regular use of amphetamines; toward reducing levels of depression among amphetamine users and interventions among people with severe psychopathology and personality disorders; and toward reducing the prevalence of tobacco dependence among amphetamine users.
The effects on mortality of brief interventions for problem drinking: a meta‐analysis
Authors: Cuijpers Pim , Riper Heleen , Lemmers Lex 
Published: June 2004

ABSTRACTAims  Brief interventions for problem drinking may result in decreased mortality rates. Long‐term follow‐up studies of brief interventions do not produce a clear answer to the question as to whether these interventions reduce mortality or not.Methods  We conducted a meta‐analysis of randomized studies comparing brief interventions with a control group, using the fixed‐effects model. A systematic literature search produced four studies in which the mortality status of subjects was verified at follow‐up. Six more studies reported some deaths at follow‐up but did not verify mortality in death registers, and 22 further studies did not report the mortality status of the included subjects.Findings  The pooled relative risk (RR) of dying was 0.47 for the four studies with verified mortality rates (95% CI: 0.25, 0.89). The pooled RR of all 32 studies was comparable (RR = 0.57; 95% CI: 0.38, 0.84), as were the RRs of several other subsamples of studies. The prevented fraction was 0.33 in the studies with verified mortality rates.Conclusions  Although the overall death rate was low in the population of problem drinkers, brief interventions do appear to reduce mortality.
Unsupervised separation of seismic waves using the watershed algorithm on time‐scale images
Authors: Roueff Antoine , Chanussot Jocelyn , Mars Jerome I. , Nguyen Minh‐Quy 
Published: June 2004

ABSTRACTThis paper illustrates the use of image processing techniques for separating seismic waves. Because of the non‐stationarity of seismic signals, the continuous wavelet transform is more suitable than the conventional Fourier transforms for the representation, and thus the analysis, of seismic processes. It provides a 2D representation, called a scalogram, of a 1D signal where the seismic events are well localized and isolated. Supervised methods based on this time‐scale representation have already been used to separate seismic events, but they require strong interactions with the geophysicist. This paper focuses on the use of the watershed algorithm to segment time‐scale representations of seismic signals, which leads to an automatic estimation of the wavelet representation of each wave separately. The computation of the inverse wavelet transform then leads to the reconstruction of the different waves. This segmentation, tracked over the different traces of the seismic profile, enables an accurate separation of the different wavefields. This method has been successfully validated on several real data sets.
Calibration of cross‐line components for sea‐bed 4C acquisition systems
Authors: Bagaini Claudio , Muyzert Everhard 
Published: June 2004

ABSTRACTFaithful recording of the elastic wavefield at the sea‐bed is required for quantitative applications of 4C seismic. The accuracy of the recorded vectorial wavefield depends on factors that vary from deployment to deployment. This paper focuses on one such factor: the interaction of the acquisition system with the sea‐bed, which is referred to here as coupling. We show, using multi‐azimuth data recorded with a cable‐based sea‐bed acquisition system, whose sensor housing is cylindrically shaped and with the in‐line geophone fixed to the cable, that coupling depends on the propagation direction and wave type (P‐ or S‐waves) of the incident wavefield. We show that coupling is more critical for S‐waves than for P‐waves. Detection of inconsistent coupling using both P‐ and S‐waves is therefore mandatory. A data‐driven processing method to compensate for the frequency‐dependent coupling response of the cross‐line geophone is derived. Its application to field data verifies the effectiveness of the method.
Optimal use of PP and PS time‐lapse stacks for fluid–pressure discrimination
Authors: Stovas A. , Landrø M. 
Published: June 2004

ABSTRACTThe combined use of time‐lapse PP and PS seismic data is analysed for optimal discrimination between pressure and saturation changes. The theory is based on a combination of the well‐known Gassmann model and the geomechanical grain model derived by Hertz and Mindlin. A key parameter in the discrimination process is the opening angle between curves representing constant changes in PP and PS reflectivity plotted against pressure and saturation changes. The optimal discrimination angle in the pressure–saturation space is 90° and this is used to determine optimal offset ranges for both PP and PS data. For typical production scenarios, we find an optimal offset range corresponding to an angle of incidence of 25–30°, for both PP and PS data. For gas we find slightly different results. This means that conventional survey parameters used in marine multicomponent acquisition should be sufficient for the purpose of estimating pressure and fluid saturation changes during production.
Fate of αGal +/+ pancreatic islet grafts after transplantation into αGal knockout mice
Authors: Chandra Abhilash P. , Salvaris Evelyn , Walters Stacey N. , Murray‐Segal Lisa , Gock Hilton , Lehnert Anne M. , Wong Jeffrey K. W. , Cowan Peter J. , D'Apice Anthony J. F. , O'Connell Philip J. 
Published: June 2004

Abstract: Background: Important phylogenetic differences between pig and human tissues prevent xenotransplantation from becoming a clinically feasible option. Humans lack the galactose‐α1,3‐galactose (αGal) epitope on endothelial cell surfaces and therefore have preformed anti‐αGal antibodies. The role of these antibodies in rejection of non‐vascular xenografts remains controversial. This study investigared the role of anti‐αGal antibodies in rejection of non‐vascularizedαGal+/+ grafts inαGal −/− mice.Methods: αGal +/+ andαGal −/− pancreatic islets were transplanted under the renal capsule of streptozotocin‐induced diabetic (1)αGal −/− mice and (2)αGal +/+ mice.αGal −/− recepients were immunized with rabbit red blood cell membranes (RRBCs) to produce elevated anti‐αGal antibody levels.Results: Six of the 18αGal −/− mice rejected theαGal +/+ grafts within 68 days whereas indefinite graft survival was achieved in the control groups. Animals with surviving islet grafts were challenged withαGal +/+ skin grafts. Although allαGal +/+ skin grafts were rejected within 58 days, the islet grafts remained intact. This observation correlated with the level ofαGal expression (which was very low on islets compared to skin) rather than the actual titre of anti‐αGal antibody.Discussion: The results suggest that the level ofαGal expression plays an important role in graft survival. Therefore, its removal is important in the development of a pig islet donor for future clinical therapy.
Anti‐pig antibody levels in non‐human primates of various origin
Authors: Lam Tuan T. , Boeke‐Purkis Katrin , Lau Macy , Paniagua Ricardo , Schuurman Henk‐Jan , Morris Randall E. 
Published: June 2004

Abstract:  Background:  Natural anti‐porcine antibodies play a major role in hyperacute solid organ xenograft rejection in the pig‐to‐non‐human primate model. Work from other groups and our experience in transplantation experiments has shown that antibody levels are highly variable between non‐human primate species, and that extremely high levels can mediate hyperacute rejection even if organs from animals transgenic for human decay‐accelerating factor are used.Methods:  Sera were obtained from cynomolgus monkeys wild‐caught in Mauritius, captive‐bred in the Philippines, captive‐bred in Indonesia (Indonesia‐Ind), and originating from Indonesia but colony‐bred in USA (Indonesia‐USA), from baboons wild‐caught in Kenya, and from rhesus monkeys originating from India but colony‐bred in USA (10 animals in each group). Antibody levels were determined using assays for haemolytic antibody (APA), IgM and IgG class anti‐Galα1‐3Gal antibody, and IgM and IgG class anti‐endothelial cell antibody.Results:  Cynomolgus monkeys from the Philippines and Indonesia‐USA and rhesus monkeys showed median APA and IgM antibody levels in the same range as a pooled human serum standard, and median IgG levels well below the level in this standard. Cynomolgus monkeys from Mauritius and Indonesia‐Ind showed extremely high APA levels (median seven to 10 times the human serum standard): IgM class antibodies were also higher, while IgG class antibodies were in the range of the level in the human serum standard. Antibody levels in baboons were in between these two categories. The results of the APA assay showed a highly statistically significant correlation with the assays of IgM antibody, and this was also the case for the IgM antibody assays, indicative of the assessment of the same antibodies in these assays. The same was observed for the assays for IgG antibody. Taking body weight as an indicator for age, there was no relationship between body weight and levels of antibodies.Conclusions:  Natural antibody levels show a significant variation between various groups of non‐human primates, with levels in some groups well above those in a human serum standard.
No transmission of porcine endogenous retrovirus after transplantation of adult porcine islets into diabetic nude mice and immunosuppressed rats
Authors: Goto Masafumi , Maeda Akira , Elfman Lotta , Suling Kristen M. , Wood James C. , Patience Clive , Groth Carl G. , Wennberg Lars 
Published: June 2004

Abstract:Background:  The aim of this study was to investigate whether transmission of porcine endogenous retrovirus (PERV) occurs in a model of diabetes reversal by the xenotransplantation of adult porcine islets (APIs) into immunoincompetent diabetic rodents.Methods:  Black‐6 nu/nu mice and Lewis rats were immunosuppressed with cyclosporin A (CsA) and FTY 720, and rendered diabetic with streptozotocin. Purified APIs were transplanted into the renal subcapsular space; 5000 islet equivalents (IEQs) were used in the nude mice (n = 4) and 40 000 IEQs in the rats (n = 4). The nude mice were sacrificed at 75 days after transplantation. In order to confirm chronic xenograft function, the graft‐bearing kidney was removed prior to sacrifice. The rats were followed until xenograft rejection, at which time they were sacrificed. Immediately after sacrifice, tissue samples (liver, spleen, and small intestine) were taken for analysis. Quantitative polymerase chain reaction (PCR) was used to assess evidence of PERV transmission, and porcine cell chimerism.Results:  All animals became normoglycemic within 48 h of transplantation. The nude mice remained normoglycemic during the 75‐day study period, with removal of the graft‐bearing kidney resulting in prompt hyperglycemia. The rats remained normoglycemic until xenograft rejection, which occurred at 66 ± 28 days. Despite the evidence of porcine cell microchimerism in recipients, real‐time PCR detected no evidence of PERV transmission in any of the tissue specimens tested.Conclusions:  There was no evidence of PERV transmission following transplantation of pig islets into diabetic nude mice and immunosuppressed rats.
MyD88‐dependent toll‐like receptor signalling is not a requirement for fetal islet xenograft rejection in mice
Authors: Schmidt Peter , Krook Henrik , Goto Masafumi , Korsgren Olle 
Published: June 2004

Abstract:  Background:  Rejection of pancreatic islet xenografts in mice shares immunopathological features with a Th1‐associated delayed‐type hypersensitivity (DTH) reaction. The aim of the present study was to investigate the mechanism of acute cellular xenograft rejection in a strain of mice with a targeted gene disruption of the toll‐like receptor (TLR) signal adaptor protein MyD88. These mice have been shown to have markedly impaired Th1 immunity.Methods:  The MyD88‐/‐ and normal mice were transplanted with 2 μl of fetal porcine islet‐like cell clusters (ICC) under the left kidney capsule. On days 3, 6 or 12 after transplantation the mice were killed and the grafts either prepared for immunohistochemistry or real‐time quantitative reverse transcriptase polymerase chain reaction (RT‐PCR). The number of remaining ICC and infiltrating cells with different phenotypic characteristics was assessed semi‐quantitatively. Grafts used for quantitative RT‐PCR were analysed for content of murine mRNA of interferon (IFN)‐γ, interleukin (IL)‐12p40, IL‐4 and IL‐10.Results:  On day 3, the rejection process was initiated in both MyD88‐/‐ and normal mice as characterized by a moderate infiltration of F4/80+ and MAC‐1+ macrophages and occasional CD3+ and CD4+ cells. Expression of IFN‐γ and IL‐12p40 was lower but still detectable in the MyD88‐/‐ mice, when compared with control animals. By day 6, rejection was almost completed in all animals with only few ICC remaining. 12 days after transplantation all grafts were completely destroyed and heavily infiltrated by macrophages. Moderate numbers of CD3+ and CD4+ and occasional CD8+ cells were also present.Conclusions:  Islet xenograft rejection was found to persist in MyD88‐/‐ mice. Despite a relatively lower expression of the Th1‐associated cytokines IFN‐γ and IL12‐p40 within the xenograft area, both the time course and morphological pattern of the rejection were essentially similar to that found in normal animals. Hence, MyD88‐dependent TLR signalling does not appear to be a crucial component of acute cellular xenograft rejection.
Bone marrow transplantation from α1,3‐galactosyltransferase gene‐knockout pigs in baboons
Authors: Tseng Y.‐L. , Dor F.J.M.F , Kuwaki K. , Ryan D. , Wood J. , Denaro M. , Giovino M. , Yamada K. , Hawley R. , Patience C. , Schuurman H.‐J. , Awwad M. , Sachs D.H. , Cooper D.K.C. 
Published: June 2004

Abstract:  Background:  Successful hematopoietic cell allotransplantation results in donor‐specific tolerance, but this approach has been unsuccessful in the wild‐type pig‐to‐baboon xenotransplantation model, as pig cells were lost from the circulation within 5 days. However, after cessation of immunosuppressive therapy on day 28, all baboons demonstrated non‐specific unresponsiveness on mixed leukocyte reaction (MLR) for at least 30 days. We have now investigated the transplantation of bone marrow (BM) cells from miniature swine homozygous for α1,3‐galactosyltransferase gene‐knockout (GalT‐KO).Methods:  Baboons (n = 3) were pre‐treated with whole body and thymic irradiation, anti‐thymocyte globulin, and splenectomy, and received immunosuppressive and supportive therapy for 28 days. BM was harvested from GalT‐KO swine (n = 3). The baboons were monitored for the presence of pig cells by flow cytometry and colony‐forming units (CFUs), and for cellular reactivity by MLR.Results:  A mean of 11 × 108 BM cells/kg was infused into each baboon. The mean absolute numbers and percentages of pig cells detected in the blood at 2 h and on days 1, 2 and 4, respectively, were 641/μl (9.5%), 132/μl (3.4%), 242/μl (3.9%), and 156/μl (2.9%). One baboon died (from accidental hemorrhage) on day 6, at which time chimerism was present in the blood (2.0%) and BM (6.4%); pig cell engraftment in the BM was confirmed by polymerase chain reaction (PCR) of CFUs. In the two other baboons, blood chimerism was lost after day 5 but returned at low levels (<1%) between days 9 to 16 and 7 to 17, respectively, indicating transient BM engraftment. Both surviving baboons showed non‐specific unresponsiveness on MLR until they were euthanized on days 85 and 110, respectively.Conclusions:  By using BM cells from GalT‐KO pigs, chimerism was detected at levels comparable with previous studies when 30‐fold more growth factor‐mobilized peripheral blood progenitor cells had been transplanted. In addition, cellular hyporesponsiveness was prolonged. However, long‐term engraftment and chimerism were not achieved.
Immune effect of hypertonic saline: fact or fiction?
Authors: Kølsen‐Petersen J. A. 
Published: June 2004

Hypertonicity affects many parts of the immune system. Animal studies and experiments in isolated cell cultures show that hypertonicity reversibly suppresses several neutrophil functions and at the same time up‐regulates T‐lymphocyte function. Infusion of hypertonic saline with or without colloids may thus, besides providing efficient plasma volume expansion, ameliorate the detrimental consequences on the immune function of trauma, shock, reperfusion, and major surgery. However, the few clinical studies conducted to date, specifically addressing the immune effect of hypertonic saline infusion, have shown little, if any, effect on markers of immune function, and larger clinical trials have not demonstrated benefit in terms of morbidity or mortality. Thus, as opposed to animal and cell‐culture studies, the immune‐modulating properties of hypertonic saline infusion would appear to be of limited value in clinical practice.This review presents in vitro studies, animal experiments, and clinical trials which investigated the consequences of hypertonic saline on markers of immune function.
Ketamine does not decrease postoperative pain after remifentanil‐based anaesthesia for tonsillectomy in adults
Authors: Van Elstraete A. C. , Lebrun T. , Sandefo I. , Polin B. 
Published: June 2004

Background:  There are conflicting results concerning the pre‐emptive effect of ketamine on central sensitization following surgery. The aim of this prospective, randomized, double‐blind, placebo‐controlled study was to assess the effect of the N‐methyl‐D‐aspartate receptor antagonist ketamine on postoperative morphine consumption and pain score after remifentanil‐based anaesthesia in adult patients scheduled for tonsillectomy.Methods:  We studied 40 adult patients undergoing elective tonsillectomy. Total intravenous anaesthesia was induced and maintained with remifentanil (0.125–1.0 µg kg−1 min−1) and propofol target‐controlled infusion. Patients in group K received a bolus dose of ketamine 0.5 mg kg−1 immediately after anaesthetic induction, followed by a continuous infusion of 2 µg kg−1 min−1. Saline was administered in the same sequence in group S. Propofol, remifentanil, and the study drug infusions were discontinued at the end of surgery.Results:  Intraoperative remifentanil consumption (0.57 ± 0.18 in group K vs. 0.55 ± 0.14 µg kg−1 min−1 in group S), morphine requirement in the PACU (11 ± 3 in group K vs. 9 ± 4 mg in group S) and in the ward (22 ± 11 in group K vs. 25 ± 14 mg in group S), median time to first analgesia in the ward (338 ± 126 in group K vs. 328 ± 144 min in group S), and VAS pain scores were comparable in both groups.Conclusion:  Small‐dose of ketamine does not seem to be a useful adjunct to remifentanil‐based anaesthesia during short, painful surgical procedures.
The effects of pre‐emptive epidural sufentanil on human immune function
Authors: Akural E. I. , Salomäki T. E. , Bloigu A. H. , Ryhänen P. , Tekay A. H. , Alahuhta S. M. , Surcel H.‐M. 
Published: June 2004

Background:  Surgical stress and general anaesthesia suppress immune functions, including natural killer cell (NK) activity. This suppression could be attributed, at least in part, to the effect of opiates.Methods:  Twenty patients undergoing abdominal hysterectomy received epidural sufentanil (50 μg) either before (pre‐emptive) or at the end (control group) of surgery. Post‐operative pain relief was provided using sufentanil from a patient‐controlled epidural analgesia (PCEA) system. Systemic immunity was assessed by determining leucocyte counts, NK cell counts and activity, lymphocyte response to mitogen stimulation, and secretion of pro‐inflammatory cytokines.Results:  In the pre‐emptive group there was a significant decrease in NK activity on the first and third post‐operative day (P < 0.05) compared with baseline values and on the third postoperative day (P < 0.05) compared with the control group. The number of total leucocytes and neutrophiles increased in both groups post‐operatively, but no differences were found in the levels of mononuclear lymphocyte populations or in their mitogen responses. Interleukin‐6 (IL‐6) concentration increased in both groups after the operation. In addition, at the end of the surgery the IL‐6 level was greater in the control group than in the pre‐emptive group. Interleukin‐1 (IL‐1) levels had decreased significantly at the end of surgery and 4 h later compared with baseline levels in the pre‐emptive, but not in the control group.Conclusions:  Pre‐emptive epidural sufentanil during combined propofol and isoflurane anaesthesia had minor effects on the immune response after hysterectomy. The lower production of pro‐inflammatory cytokines (IL‐1, IL‐6) in the pre‐emptive group compared with the control group is beneficial, but its clinical importance remains to be determined.