bluuebunny/crossref_metadata_2025 huggingface dataset:
A redetermination of absolute values for 17RVPDB‐CO2 and 17RVSMOW
Authors: Assonov Sergey S. , Brenninkmeijer Carl A. M.
Published: April 2003

In a companion paper in this issue we presented a review of the current state of 17O‐corrections for CO2 mass spectrometry and considered an approach (including algebraic formulae) of how to determine absolute values for 17RVPDB‐CO2 and 17RVSMOW. Here we present the results of experiments conducted to determine these values. Two oxygen gases (one depleted in heavy isotopes and the other isotopically normal oxygen) were analysed to obtain the relative 17O content. Samples of both gases were converted into CO2, and the resulting CO2 samples were analysed as well. Possible experimental and analytical errors are carefully considered and eliminated as far as feasible. Much attention was paid to understanding and dealing with cross‐contamination effects occurring in the mass spectrometer. Based on the data obtained, the absolute values are calculated to be: 17RVPDB‐CO2 = 0.00039511 ± 0.00000094 and 17RVSMOW = 0.00038672 ± 0.00000087 (expanded uncertainties). Both values are on the original scale of Craig (Geochim. Cosmochim. Acta 1957; 12: 133–149) with 13RVPDB‐CO2 = 0.0112372. A 17O‐correction algorithm incorporating the newly determined value for 17RVPDB‐CO2 and λ = 0.528 by Meijer and Li (Isot. Environ. Health Stud. 1998; 34: 349–369) is constructed. A computational test is performed to demonstrate the degree of δ13C bias relative to the previously known correction algorithms. δ13C values produced by the constructed algorithm are in the middle of the values produced by the other algorithms. We refrain, however, from giving any recommendation concerning which 17O‐correction algorithm to use in order to obtain δ13C data in the most accurate way. The present work illuminates the need to reconsider recommendations concerning the correction algorithm. Copyright © 2003 John Wiley & Sons, Ltd.
A mixture model for bovine abortion and foetal survival
Authors: Hanson Timothy , Bedrick Edward J. , Johnson Wesley O. , Thurmond Mark C.
Published: April 2003

The effect of spontaneous abortion on the dairy industry is substantial, costing the industry on the order of $200 million per year in California alone. We analyse data from a cohort study of nine dairy herds in Central California. A key feature of the analysis is the observation that only a relatively small proportion of cows will abort (around 10¯15 per cent), so that it is inappropriate to analyse the time‐to‐abortion (TTA) data as if it were standard censored survival data, with cows that fail to abort by the end of the study treated as censored observations. We thus broaden the scope to consider the analysis of foetal lifetime distribution (FLD) data for the cows, with the dual goals of characterizing the effects of various risk factors on (i) the likelihood of abortion and, conditional on abortion status, on (ii) the risk of early versus late abortion. A single model is developed to accomplish both goals with two sets of specific herd effects modelled as random effects. Because multimodal foetal hazard functions are expected for the TTA data, both a parametric mixture model and a non‐parametric model are developed. Furthermore, the two sets of analyses are linked because of anticipated dependence between the random herd effects. All modelling and inferences are accomplished using modern Bayesian methods. Copyright © 2003 John Wiley & Sons, Ltd.
Hierarchical Bayesian spatial modelling of small‐area rates of non‐rare disease
Authors: MacNab Ying C.
Published: April 2003

We present Bayesian hierarchical spatial models for the analysis of the geographical distribution of a non‐rare disease or event. The work is motivated by the need for ascertaining regional variations in health services outcomes and resource use and for assessing the potential sources of these variations. The models discussed herein readily accommodate random spatial effects and covariate effects. We discuss Bayesian inferential framework and implementation of a hybrid Markov chain Monte Carlo method for full Bayesian model inference. The methods are illustrated through an analysis of regional variation in chronic lung disease (CLD) rates among neonatal intensive care unit (NICU) patients across Canada. Specifically, we first present a random effects binomial model for spatially correlated CLD rates, with random spatial effects accounting for latent or covariate effects. These random spatial effects depict regional or spatial variation in chronic lung disease occurrence. We then extend this model to include covariates. With this extension, we assess residual spatial effects and the extent to which risk factors such as illness severity at NICU admission, low birth weight, and very low birth weight influence the CLD rate variation. Copyright © 2003 John Wiley & Sons, Ltd.
Tropical Atlantic variability in a coupled GCM
Authors: Liu Zhengyu , Wu Lixin
Published: April 2003

Tropical Atlantic Variability (TAV) is simulated in a coupled GCM. The TAV seems to be consistent with a dipole mode that involves both surface and subsurface oceanic dynamics. The poor correlation of the tropical North and South Atlantic SST is suggested to be distorted by the presence of a symmetric tropical Atlantic mode. Copyright © 2000 Royal Meteorological Society.
An efficient and accurate correlated‐k parameterization of infrared radiative transfer for troposphere–stratosphere–mesosphere GCMs
Authors: Zhong Wenyi , Haigh Joanna D.
Published: April 2003

An efficient and accurate correlated‐k parameterization of infrared radiative transfer for the troposphere, stratosphere and mesosphere (TSM) has been developed. A new approach of g‐quadrature, using the delta log(k) method with non‐uniform intervals, was found to be most efficient. Validation against line‐by‐line calculations for 1D and 2D fields are presented. The scheme is efficient enough to be run in TSMGCMs. Copyright © 2001 Royal Meteorological Society.
Psychological autopsy studies of suicide: a systematic review
Authors: CAVANAGH J. T. O. , CARSON A. J. , SHARPE M. , LAWRIE S. M.
Published: April 2003

Background. The psychological autopsy method offers the most direct technique currently available for examining the relationship between particular antecedents and suicide. This systematic review aimed to examine the results of studies of suicide that used a psychological autopsy method.

Method. A computer aided search of MEDLINE, BIDS ISI and PSYCHLIT, supplemented by reports known to the reviewers and reports identified from the reference lists of other retrieved reports. Two investigators systematically and independently examined all reports. Median proportions were determined and population attributable fractions were calculated, where possible, in cases of suicide and controls.

Results. One hundred and fifty-four reports were identified, of which 76 met the criteria for inclusion; 54 were case series and 22 were case–control studies. The median proportion of cases with mental disorder was 91% (95% CI 81–98%) in the case series. In the case–control studies the figure was 90% (88–95%) in the cases and 27% (14–48%) in the controls. Co-morbid mental disorder and substance abuse also preceded suicide in more cases (38%, 19–57%) than controls (6%, 0–13%). The population attributable fraction for mental disorder ranged from 47–74% in the seven studies in which it could be calculated. The effects of particular disorders and sociological variables have been insufficiently studied to draw clear conclusions.

Conclusions. The results indicated that mental disorder was the most strongly associated variable of those that have been studied. Further studies should focus on specific disorders and psychosocial factors. Suicide prevention strategies may be most effective if focused on the treatment of mental disorders.
Neuropsychological impairment in patients with major depressive disorder: the effects of feedback on task performance
Authors: MURPHY F. C. , MICHAEL A. , ROBBINS T. W. , SAHAKIAN B. J.
Published: April 2003

Background. Recent evidence suggests that an abnormal response to performance feedback may contribute to the wide-ranging neuropsychological deficits typically associated with depressive illness. The present research sought to determine whether the inability of depressed patients to utilize performance feedback advantageously is equally true for accurate and misleading feedback.

Method. Patients with major depression and matched controls completed: (1) a visual discrimination and reversal task that featured intermittent and misleading negative feedback; and (2) feedback and no-feedback versions of a computerised test of spatial working memory. In the feedback version, negative feedback was accurate, highly informative, and could be used as a mnemonic aid.

Results. On the Probability Reversal task, depressed patients were impaired in their ability to maintain response set in the face of misleading negative feedback as shown by their increased tendency to switch responding to the ‘incorrect’ stimulus following negative reinforcement, relative to that of controls. Patients' ability to acquire and reverse the necessary visual discrimination was unimpaired. On the Spatial Working Memory task, depressed patients made significantly more between-search errors than controls on the most difficult trials, but their ability to use negative feedback to facilitate performance remained intact.

Conclusions. The present results suggest that feedback can have different effects in different contexts. Misleading, negative feedback appears to disrupt the performance of depressed patients, whereas negative but accurate feedback does not. These findings are considered in the context of recent studies on reinforcement systems and their associated neurobiological substrates.
Does ‘like predict like’ when patients discharged from high secure hospitals re-offend? An instrument to describe serious offences
Authors: BUCHANAN A. , REISS D. , TAYLOR P. J.
Published: April 2003

Background. The statement that past behaviour is the best predictor of future behaviour has empirical support in respect of whether an individual will, or will not, commit a criminal offence. People who have offended in the past are more likely to offend in the future. The aims of this study were to develop an instrument and to examine whether the same statement applies in respect of the nature and circumstances of successive offences committed by the same person.

Method. A rating instrument to describe seven variables relating to the nature and circumstances of a serious offence, the SODI, was developed by the authors. Inter-rater reliability was measured when the instrument was applied to 80 offences committed by 40 patients leaving high secure hospitals. The data were examined for evidence of similarity in the nature and circumstances of successive offences.

Results. For five of the seven items of the instrument the kappa coefficients for inter-rater reliability were >0·65. No significant associations, in terms of SODI ratings, were found between the offence that led to hospital admission and that which was committed after discharge.

Conclusions. The SODI is a reliable instrument for the description of serious offences committed by this group. Risk assessments in psychiatry should be informed by an awareness that in only a proportion of cases will the nature and circumstances of any serious re-offence resemble the nature and circumstances of the offence which contributed to a patient's admission to hospital.
Venous hemodynamics in living donor right lobe liver transplantation
Authors: Gondolesi Gabriel E. , Florman Sander , Matsumoto Cal , Huang Ruoqing , Fishbein Thomas M. , Sheiner Patricia A. , Schwartz Myron E. , Emre Sukru , Thung Swan , Shapiro Robert , Miller Charles M.
Published: April 2003

We evaluated the influence of portal and hepatic venous hemodynamics on the immediate and 3-month postoperative function of living donor right lobe grafts. Portal velocity was measured prospectively by ultrasound in 14 consecutive donor/recipient pairs. Velocity was converted to flow with the Moriyasu formula. Measurements were taken in donors in the operating room and in recipients at 1 hour after reperfusion and 3 months after transplant. Recipient liver function tests were measured postoperatively. Prereperfusion and postreperfusion liver biopsies were evaluated and correlated with the hemodynamic and biochemical results. There were 11 male (78.6%) and 3 female donors (mean age, 38.9 ± 9.8 years) for 10 male (71.4%) and 4 female recipients (mean age, 49.3 ± 14 years). The mean graft/recipient weight ratio was 1.22 ± 0.3. The mean right portal vein pressure was 8 ± 1.8 mm Hg in donors versus 13 ± 4.7 mm Hg in recipients (P < .05). The mean peak flow velocity (Vmax) in the portal vein in donors was 47.6 ± 12.8 cm/sec (normal, 44 cm/sec). One hour after graft reperfusion in the recipient, the mean portal Vmax was significantly higher at 94.7 ± 28.4 cm/sec (P = .004), but by 3 months follow-up, mean portal Vmax had fallen to 58.8 ± 37.8 (P = .01). Recipient portal vein Vmax highly correlated with portal flow (r = 0.7, P = .01). Increased recipient total bilirubin on postoperative day 2 correlated highly with higher recipient portal flow one hour after transplant (r = 0.6; P = .03). Portal vein velocity/flow dramatically increases after reperfusion, returning to baseline about 3 months after transplant. Evaluation of hepatic and portal venous flow is a relatively easy skill to acquire. Intraoperative ultrasound may enable the surgeon to predict graft dysfunction and possibly, may be used to implement pre-emptive therapies.
Pulmonary gas exchange abnormalities in liver transplant candidates
Authors: Mohamed Rosmawati , Freeman Jonathan W. , Guest Peter J. , Davies Michael K. , Neuberger James M.
Published: April 2003

Abnormal diffusing capacity is the commonest pulmonary dysfunction in liver transplant candidates, but severe hypoxemia secondary to hepatopulmonary syndrome and significant pulmonary hypertension are pulmonary vascular manifestations of cirrhosis that may affect the perioperative course. We prospectively assessed the extent of pulmonary dysfunction in patients referred for liver transplantation. A total of 57 consecutive patients with chronic liver disease were evaluated. All patients had a chest radiograph, standing arterial blood gas on room air, pulmonary function testing, and Doppler echocardiogram. Those patients with arterial hypoxaemia (PaO2 < 10 kPa) also underwent 99mTc-macroaggregated albumin lung scan, and nine patients had agitated normal saline injection during echocardiography to define further the existence of pulmonary vascular dilatation. Reduced diffusing capacity for carbon monoxide less than 75% of the predicted value was found in 29 of 57 (51%) patients. Although elevated alveolar-arterial oxygen tension difference was detected in 35% (20/57) of the patients, only four (7%) patients had hypoxemia. We were unable to find evidence of intrapulmonary vascular dilatation either on the lung scan or saline-enhanced echocardiography in any of these patients. Reduction in diffusing capacity for carbon monoxide was noted in 75% (18/24) of patients who were transplanted for primary biliary cirrhosis and was accompanied by widened alveolar-arterial oxygen tension in 10 out of 18 (56%) of patients. This study shows that in liver transplant candidates, diffusion impairment and widened alveolar-arterial oxygen tension difference were frequently detected, especially in patients with primary biliary cirrhosis.
Liver transplantation for patients on methadone maintenance
Authors: Kanchana Thirumalesh P. , Kaul Vivek , Manzarbeitia Cosme , Reich David J. , Hails Kevin C. , Munoz Santiago J. , Rothstein Kenneth D.
Published: April 2003

Most transplant programs require abstinence of at least 6 months from alcohol and illicit drugs before orthotopic liver transplantation (OLT). However, there are no published data regarding OLT outcomes in patients who are currently on methadone maintenance treatment (MMT) as part of the treatment of their heroin addiction at the time of OLT. The objective of this study is to evaluate our experience regarding the outcome of OLT in patients with end-stage liver disease (ESLD) who were on MMT at the time of OLT. Between March 1993 and May 1999, a total of 185 patients with ESLD underwent OLT at our center. Five transplant recipients (2.7%) had a history of heroin abuse and had undergone drug and alcohol rehabilitation, but could not be weaned off methadone. Pre-OLT status, drug history, perioperative course, compliance with medical therapy, post-OLT follow-up, and patient and allograft survival were analyzed in detail in these patients. All patients on MMT underwent uneventful OLTs. Their compliance with medications and follow-up was excellent. One patient was weaned completely off methadone after OLT. Post-OLT mean hospital stay in this group was 43 ± 25 days. Although the number of patients was small, long-term outcome of liver transplant recipients on MMT appears similar to that of patients not on MMT who underwent OLT during this period. Our results suggest cirrhotic patients on MMT should be considered for OLT if they meet the same psychosocial requirements as patients with alcohol abuse. Furthermore, it is not necessary for patients to be weaned off methadone before OLT.
Donor evaluation, donor risks, donor outcome, and donor quality of life in adult-to-adult living donor liver transplantation
Authors: Pascher Andreas , Sauer Igor M. , Walter Marc , Lopez-Haeninnen Enrique , Theruvath Tom , Spinelli Antonino , Neuhaus Ruth , Settmacher Utz , Mueller Andrea R. , Steinmueller Thomas , Neuhaus Peter
Published: April 2003

Right lobe living donor liver transplantation (LD-LTx) is currently performed at an increasing number of transplant centers. Donor selection, donor safety, donor recovery, and postdonation psychological impairment are essential criteria to determine whether and under which conditions LD-LTx is justifiable. Before commencing the LD-LTx program, approval was obtained from the local ethics committee. Potential donors underwent a comprehensive multistep evaluation protocol to exclude any conditions that could lead to an increased operative risk. Each donation was approved by the local Living Donation Commission. Follow-up investigations were performed after 6 and 12 months. Liver regeneration was assessed by computed tomography scan and magnetic resonance imaging scan derived volumetries. Quality of life (QOL) was investigated according to the Anamnestic Comparative Self-Assessment Scale (ACSA) before donation, and 6 and 12 months after donation. As of December 2001, 43 right lobe living donations have been performed at the Charité, Campus Virchow, Berlin. None of the donors died or has suffered life-threatening or persisting complications. All patients recovered completely. Complications occured in 8 donors (18%). The incidence of perioperative surgical complications was 9%, comprising temporary biliary leakages (n = 3; 6.8%) as well as postoperative bleeding (n = 1). Liver volume regeneration approximated 72% ± 15% of predonation volume by 6 months and 85% ± 18% (mean ± SD) by 12 months. There was no evidence of significant psychological impairment after donation. QOL increased after donation compared with the preoperative state (P < .05). In our experience, LD-LTx has proven to be a practicable and safe procedure. However, there is a considerable risk of postoperative complications. The donor selection process plays a pivotal role in preventing complications. The discussion of potential risks, especially potential life-threatening risks, must be an integral part of informed consent.
Differential allograft gene expression in acute cellular rejection and recurrence of hepatitis C after liver transplantation
Authors: Sreekumar Raghavakaimal , Rasmussen Deborah L. , Wiesner Russell H. , Charlton Michael R.
Published: April 2003

Treatment of acute cellular rejection (ACR) is associated with increased viral load, more severe histologic recurrence, and diminished patient and graft survival after liver transplantation for hepatitis C virus (HCV). Recurrence of HCV may be difficult to distinguish histologically from ACR. Because the immunologic mechanisms of ACR and HCV recurrence are likely to differ, we hypothesized that ACR is associated with the expression of a specific subset of immune activation genes that may serve as a diagnostic indicator of ACR and provide mechanistic insight into the pathophysiology of ACR and recurrence of HCV. The goal of the study was to study intragraft gene expression patterns in ACR and during recurrence of HCV in HCV-infected recipients. High-density microarrays were used to determine relative intragraft gene expression in two groups of HCV-infected liver transplant recipients: four with steroid responsive ACR by Banff criteria and four age- and gender-matched HCV-infected recipients with similar necroinflammatory activity but without histological criteria for rejection (no cholangitis or endotheliitis). Immunosuppression was similar in both groups. Other etiologies of graft dysfunction were excluded by ultrasound, cholangiography, and cultures. High-quality total RNA was extracted from snap frozen liver biopsies, reverse transcribed, labeled with biotin, and fragmented according to established protocol. Twenty-five genes were relatively overexpressed, and 15 were relatively underexpressed by ≥twofold in the ACR when compared with the HCV group. ACR was most notably associated with the relative overexpression of genes associated with major histocompatibility complex I and II, insulin-like growth factor-1 expression, apoptosis induction, and T-cell activation. In HCV-infected liver transplant recipients, ACR is associated with an intragraft gene expression profile that is distinct from that seen during recurrence of HCV. These experiments provide evidence that alloimmunity, as indicated by expression of T-cell activation and apoptosis-inducing genes, is less important in recurrence of HCV than in ACR. Further studies are required to determine whether gene expression profiles, either intragraft or in serum, can be used for the diagnosis and differentiation of ACR from recurrence of HCV.
The caspase inhibitor IDN-6556 prevents caspase activation and apoptosis in sinusoidal endothelial cells during liver preservation injury
Authors: Natori Shiho , Higuchi Hajime , Contreras Patricia , Gores Gregory J.
Published: April 2003

Cold ischemia (CI)-warm reperfusion (WR) liver injury remains a problem in liver transplantation. CI-WR initially causes sinusoidal endothelial cell (SEC) apoptosis through a caspase-dependent mechanism. We previously showed that the caspase inhibitor IDN-1965 prevents CI-WR-induced SEC apoptosis. However, this agent required to be administered to the donor, preservation solution, and recipient for efficacy. Here, we show that a second-generation caspase inhibitor, IDN-6556, effectively prevents CI-WR-induced SEC injury when added only to University of Wisconsin (UW) cold storage media. Rat livers were stored in UW solution for 24 hours at 4°C and reperfused for 1 hour at 37°C. Apoptosis was quantitated using terminal deoxynucleotide transferasemediated deoxyuridine triphosphate nick end labeling (TUNEL) assay and caspase 3 activation determined by biochemical measurement and immunohistochemical analysis. Pan-caspase inhibitors (IDN-8066, IDN-7503, IDN-7436, IDN-1965, and IDN-6556) were applied at preischemic, cold preservation, or reperfusion periods. TUNEL-positive SEC and caspase 3-like activity in the liver was increased by CI-WR. Three caspase inhibitors (IDN-8066, IDN-1965, and IDN-6556) effectively attenuated SEC apoptosis and caspase 3 activation. The most potent inhibitor, IDN-6556, reduced SEC apoptosis and caspase 3 activity by 55% and 94%, respectively. Prevention of SEC apoptosis by IDN-6556 was not reduced when this agent was administered only during the cold preservation period. When added to the preservation solution, the caspase inhibitor IDN-6556 appears to be a feasible therapeutic agent against ischemia-reperfusion injury in liver transplantation.
Predictive models of short- and long-term survival in patients with nonbiliary cirrhosis
Authors: Longheval Gérald , Vereerstraeten Pierre , Thiry Philippe , Delhaye Myriam , le Moine Olivier , Devière Jacques , Bourgeois Nadine , Adler Michael
Published: April 2003

The limited number of donor organs has placed a burden on the medical community to improve patient selection and timing of liver transplantation (LT). We aim to evaluate short- and long-term survival of 124 consecutive patients with a diagnosis of nonbiliary cirrhosis. Seventeen clinical, biochemical, functional, and hemodynamic parameters were computed. Patient survival was evaluated in the short term (3 months) by logistic regression, and the predictive power of the model was evaluated using receiver operating characteristic curves and the log likelihood ratio. For the long-term (up to 5 years) prognosis, the Cox proportional model was used. During follow-up, 54 patients died and 20 patients underwent LT. In the short-term study, the Model for End-Stage Liver Disease score (including bilirubin level, international normalized ratio [INR], and creatinine level) was as predictive as our score, which contained only two independent indicators (bilirubin and creatinine levels). In the long-term study, three independent variables (albumin level, INR, and creatinine level) emerged from the Cox model, and patients were classified into three survival-risk groups according to a prognostic index (PI): −1.039 × albumin (grams per deciliter) + 1.909 × loge INR + 1.207 × loge serum creatinine (milligrams per deciliter). Survival probabilities at 1 and 5 years were 89% and 80%, 63% and 52%, and 23% and 10% with a low, medium, and high PI, respectively. The validation study using the split-sample technique and data from independent patients confirmed that a high PI (>−2.5) identifies patients with a poor prognosis within 5 years. We thus have shown and validated that risk for death at the short and long term of patients with nonbiliary cirrhosis can be predicted with great accuracy using models containing a few simple and easily obtained objective variables, and these survival models are useful tools in clinical decision making, especially in deciding to list patients for LT and prioritization on the liver waiting list.
RADIAL BASIS PROBABILISTIC NEURAL NETWORKS: MODEL AND APPLICATION
Authors: HUANG DE-SHUANG
Published: April 2003

This paper investigates the capabilities of radial basis function networks (RBFN) and kernel neural networks (KNN), i.e. a specific probabilistic neural networks (PNN), and studies their similarities and differences. In order to avoid the huge amount of hidden units of the KNNs (or PNNs) and reduce the training time for the RBFNs, this paper proposes a new feedforward neural network model referred to as radial basis probabilistic neural network (RBPNN). This new network model inherits the merits of the two old odels to a great extent, and avoids their defects in some ways. Finally, we apply this new RBPNN to the recognition of one-dimensional cross-images of radar targets (five kinds of aircrafts), and the experimental results are given and discussed.
Determinants of survival in pulmonary Langerhans' cell granulomatosis (histiocytosis X). Groupe d'Etude en Pathologie Interstitielle de la Societe de Pathologie Thoracique du Nord
Authors: Delobbe A , Durieu J , Duhamel A , Wallaert B
Published: April 2003

The course of pulmonary Langerhans' cell granulomatosis (pulmonary LCG) is variable, difficult to predict and ranges from spontaneous remission to progressive respiratory insufficiency and death. To identify the determinants of survival, we performed a survival analysis on 45 patients with pulmonary LCG. The patients were aged 28 +/- 10 yrs (mean +/- SD) (range 12-62 yrs), 32 males and 13 females, almost exclusively current smokers (96%), and 78% presented symptoms at the time of diagnosis. Diagnosis was made by lung biopsy in 25 patients (56%) and by bronchoalveolar lavage (BAL) analysis in 20 patients (44%). The patients were followed for a median period of 6 yrs (range 1-29 yrs) after the diagnosis. During the period of observation, 33 (73%) patients survived (median follow-up period = 5.8 yrs; range, 1-29 yrs) and 12 (27%) died or underwent lung transplantation (median follow-up period = 8.4 yrs; range 1.4 - 16.1 yrs). The median survival was approximately 13 years. A univariate analysis demonstrated that diminished survival was significantly associated with: an older age at diagnosis (p = 0.0001); a lower forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio at diagnosis (p = 0.005); a higher residual volume/total lung volume (RV/TLC) ratio at diagnosis (p = 0.02); and steroid therapy during follow-up (p = 0.03). Additional predictive information on mortality was: age > 26 yrs (sensitivity 83%, specificity 64%); FEV1/FVC ratio < 0.66 (sensitivity 75%, specificity 86%); and a RV/TLC ratio > 0.33 (sensitivity 75%, specificity 63%). In multivariate Cox analysis, the combination of factors which gave the best prognostic value was FEV1/FVC ratio and age (p < 0.01). The present findings suggest that adverse prognosis factors at diagnosis in pulmonary Langerhans' cell granulomatosis include older age, lower FEV1/FVC ratio and higher RV/TLC ratio, with additional predictive information on mortality if aged > 26 yrs, FEV1/FVC ratio < 0.66, and RV/TLC ratio > 0.33.
Pulmonary haemodynamics after single-lung transplantation for end-stage pulmonary parenchymal disease
Authors: Bjortuft O , Simonsen S , Geiran OR , Fjeld JG , Skovlund E , Boe J
Published: April 2003

In a prospective study, we investigated the effect of single-lung transplantation (SLT) on pulmonary haemodynamics and the relationship between pulmonary hypertension (PH) and the fraction of perfusion to the transplant in patients with end-stage pulmonary parenchymal disease. Twenty four SLT recipients were included in the study, 19 with chronic obstructive pulmonary disease (COPD), two with sarcoidosis and three with fibrosing alveolitis. Spirometry, determination of arterial blood gas values, perfusion scintigraphy and right heart catheterization were performed before and 1, 6, 12 and 24 months after transplantation. Patients with a mean pulmonary artery pressure (Ppa) > or = 20 mmHg before transplantation were defined as having PH (PH group, 15 patients) and the remainder (9 patients) constituted the non-PH group. In the PH group, Ppa and pulmonary vascular resistance (PVR) were significantly decreased after transplantation: 28 +/- 2 to 18 +/- 1 mmHg and 288 to 161 +/- 11 dyne.s-1.cm-5, respectively (mean +/- SEM). In the non-PH group, the haemodynamic parameters were unchanged after transplantation. Over the 2 year follow-up period, no significant change was found in Ppa and PVR, nor any difference between the PH and non-PH group. There was no significant difference between the two groups in terms of pulmonary perfusion to the graft. In conclusion, patients with pulmonary hypertension obtain pulmonary haemodynamics within the normal range after single-lung transplantation. Presence or absence of pulmonary hypertension before transplantation does not influence perfusion to the graft. These findings persist up to 2 yrs, despite the coexistence of an "end-stage" native lung and a lung transplant.
Bronchogenic cysts: clinicopathological presentation and treatment
Authors: Aktogu S , Yuncu G , Halilcolar H , Ermete S , Buduneli T
Published: April 2003

The aim of this study was to evaluate the preoperative and operative presentations of one paediatric and 30 adult patients with bronchogenic cyst of the mediastinum (n = 11) and lung (n = 20). At initial presentation, six patients were asymptomatic and 25 were symptomatic. The mean age of asymptomatic and symptomatic patients was 25 and 33 yrs, respectively. Six patients presented with complications, including superior vena cava syndrome, tracheal compression, pneumothorax, pleurisy and pneumonia. Two patients who were asymptomatic when initially observed eventually needed surgery because of the development of symptoms or enlargement of the cyst size. In one patient, the cyst was not seen on the chest radiograph but appeared as a lobulated nodule of 2 cm diameter in a chest computerized tomography (CT) scan. Operative difficulties were encountered in 13 patients, all of whom were symptomatic preoperatively. In conclusion, life-threatening complications occurred in these patients. Despite various diagnostic studies, definitive tissue diagnosis was established only by means of surgical excision. The frequency of operative difficulties in symptomatic cysts was higher than those of asymptomatic cysts. Surgery may be considered as the treatment of choice even when the cyst is asymptomatic, since complications are not uncommon.
Clinical spectrum of pulmonary and pleural tuberculosis: a report of 5,480 cases
Authors: Aktogu S , Yorgancioglu A , Cirak K , Kose T , Dereli SM
Published: April 2003

The aim of the present study was to investigate the epidemiological, clinical, laboratory and radiological features of patients with active pulmonary tuberculosis (TB) (with or without pleural involvement) or with pleural TB (in the absence of radiological parenchymal disease). A systematic predetermined form, including 60 items regarding the above-mentioned features, was completed for 5,480 patients. Sputum smear and culture data, radiological findings, and additional extrapulmonary involvement were evaluated in the patients with pulmonary TB (n = 5,094). Epidemiological features, and other clinical and laboratory characteristics were investigated in all patients (n = 5,480). TB was more common among persons aged 20-39 yrs, males, and those living in large urban centres in our region. There were 4,268 newly detected patients (78%), and 1,212 active ex-patients (22%) who had history of previous antituberculosis treatment. Additional extrapulmonary involvement was found in 455 patients (9%). Sputum samples were smear-positive in 3,916 (79%), and culture-positive in 3,748 cases (76%). Most common radiological patterns were parenchymal infiltrate in 5,017 (99%), and cavitation in 3,363 (66%). Unusual radiological patterns were also noted, i.e., lower lung field TB (LLFTB) in 317 cases (6.2%), pneumothorax in 78 cases (1.5%), and miliary pattern in 66 cases (1.3%). In conclusion, because of the more frequent occurrence in the younger age group, it is considered that the prevalence of disease is still high and that the transmission of tubercle bacilli is not decreasing in our region. The highest risk group consisted of male subjects and those living in urban centres. The high percentage of active ex-patients suggests that new control programmes for tuberculosis are required in Turkey.
Postjunctional effect of pinacidil on contractility of isolated bovine trachealis
Authors: Song P , Rocchi D , Lazzarotti M , Crimi E , Rehder K , Brusasco V
Published: April 2003

Potassium channel openers hyperpolarize the smooth muscle cell membrane and relax airway smooth muscle. In this study, pre- and postjunctional effects of pinacidil ((+/-) N-cyano-N'-(4-pyridil)-N"-(1,2,2-trimethylpropyl)-guanidine monohydrated), an adenosine triphosphate (ATP)-sensitive K(+)-channel opener, were determined in isolated bovine trachealis. The effects of pinacidil on the frequency-response to electrical field stimulation (EFS), 0.1-32 Hz, and on the concentration response to acetylcholine (ACh), 10(9)-10(-4) M, were compared in muscle strips from six animals. In addition, the effect of pinacidil on the inhibitory nonadrenergic noncholinergic (iNANC) system was evaluated in histamine-contracted muscle strips from another eight animals. Pinacidil (10(-6) or 10(-5) M) shifted both the EFS frequency-response and the ACh concentration-response curves significantly (p < 0.01) to the right. Glibenclamide (10(-7)-10(-5) M) antagonized these responses in a concentration-dependent manner. The inhibitory effects of pinacidil on contractions of the same magnitude induced by EFS or exogenous ACh were not significantly different (p = 0.11), suggesting that pinacidil had only a postjunctional effect. Pinacidil had no effect on iNANC-mediated muscle relaxation. We conclude that pinacidil attenuates the contraction of isolated bovine tracheal smooth muscle by postjunctional mechanisms.
Defective inhibition of sodium on basophil histamine release in patients with allergic rhinitis and bronchial asthma
Authors: Tedeschi A , Cottini M , Salmaso C , Milazzo N , Miadonna A
Published: April 2003

The aim of this study was to evaluate whether Na+ exerts its inhibitory effect on basophil histamine release induced by immunoglobulin E (IgE)-dependent (anti-IgE) and IgE-independent (N-formyl-methionyl-leucyl-phenylalanine (FMLP), interleukin-3 (IL-3)) stimuli in patients with allergic rhinitis (n = 24) and allergic bronchial asthma (n = 10). Peripheral blood leucocytes were stimulated with anti-IgE, FMLP and IL-3 in the presence of high and low Na+ concentrations, and histamine release was measured using a fluorometric method. In standard Na(+)-containing medium, spontaneous and stimulated histamine release was higher in allergic patients (n = 34) (both rhinitic and asthmatic) than in healthy subjects (n = 41). Na+ removal from extracellular medium and its isosmotic substitution with choline chloride or with N-methyl-D-glucamine led to a significant increase of anti-IgE-, FMLP- and IL-3-induced histamine release in normal subjects, but not in allergic patients. The increase in Na+ concentration in the extra-cellular medium was accompanied by a dose-dependent decrease of anti-IgE- and FMLP-induced histamine release in normal subjects, but not in allergic patients. The behaviour of atopics and healthy subjects was different and not related to the basophil responsiveness to activating signals. The incubation of basophils from healthy subjects with sera from allergic patients did not have a significant influence on the inhibitory effect of Na+. Basophils from healthy subjects and atopic patients respond differently when stimulated in a low Na+ medium. The reduced sensitivity to the inhibitory effect of Na+ may contribute to basophil dysfunction in patients with respiratory allergy.
Assessment of airway inflammation in children with acute asthma using induced sputum
Authors: Twaddell SH , Gibson PG , Carty K , Woolley KL , Henry RL
Published: April 2003

The aims of this study were: to assess the safety of a sputum induction method using inhaled normal saline in children with acute asthma; and to investigate changes in sputum cell counts between acute exacerbations of asthma and its resolution. Ultrasonically nebulized normal saline was used to induce sputum from children (n = 8) presenting with acute asthma within 1 h of arrival and again at least 14 days later, after resolution of the exacerbation. Children received pretreatment with bronchodilator, and peak expiratory flow (PEF) was monitored throughout the procedure. Samples were analysed for total cell count, differential cell counts, and for eosinophils and neutrophils using specific immunochemical stains. Sputum induction was performed without adverse effect in each child with acute asthma. The mean fall in PEF from baseline during sputum induction was 5.3% during the acute attack and 3.4% at resolution. A shorter nebulization time was required to induce sputum in acute asthma than at follow-up (7.8 vs 13.9 min; p = 0.04). During acute asthma, there was an intense cellular infiltrate (mean total cell count 34 x 10(6) cells.mL-1), which resolved after recovery (1.9 x 10(6) cells.mL-1) (p = 0.04). The infiltrate was heterogenous, comprising eosinophils (6.7 x 10(6) cells.mL-1), neutrophils (5.4 x 10(6) cells.mL-1) and mast cells (0.47 x 10(6) cells.mL-1). Resolution of the exacerbation was accompanied by a significant fall in eosinophils and neutrophils (p < or = 0.04). Normal saline induction of sputum can be used to assess airway inflammation in acute asthma. Children with acute asthma have intense airway inflammation that is heterogeneous and involves neutrophils, eosinophils and mast cells.
Expiratory flow limitation during sleep in heavy snorers and obstructive sleep apnoea patients
Authors: Stanescu D , Kostianev S , Sanna A , Liistro G , Veriter C
Published: April 2003

Inspiratory flow limitation (FL) during sleep has previously been reported both in obstructive sleep apnoea (OSA) patients and heavy snorers (HS). Recent results from this laboratory have shown the occurrence both of inspiratory and expiratory flow limitation during muscular relaxation in awake healthy subjects and OSA patients. In this study, we have investigated whether expiratory flow limitation occurs during sleep in heavy snorers and in patients with OSA. We studied four nonapnoeic, heavy snorers and five OSA patients. Airflow was measured with a pneumotachograph attached to a tight-fitting mask, and supraglottic pressure with a catheter placed at the supraglottic level. Scoring for flow limitation was achieved by visual inspection of 200 breaths recorded during sleep. About 20% of the respiratory cycles presented isolated inspiratory flow limitation. Approximately the same percentage was observed in heavy snorers and OSA patients. Isolated expiratory flow limitation was less frequently recorded. Coupled inspiratory and expiratory flow limitations were more numerous, especially in heavy snorers. We conclude that both in heavy snorers and obstructive sleep apnoea patients, inspiratory flow limitation is associated with expiratory flow limitation. This suggests that upper airway obstruction during sleep is both an inspiratory and expiratory event.
Increased prevalence of sleep disturbances and daytime sleepiness in subjects with bronchial asthma: a population study of young adults in three European countries
Authors: Janson C , De Backer W , Gislason T , Plaschke P , Bjornsson E , Hetta J , Kristbjarnarson H , Vermeire P , Boman G
Published: April 2003

The aim of this study was to investigate whether asthma is associated with decreased quality of sleep and increased daytime sleepiness. The study involved a random population of 2,202 subjects supplemented by 459 subjects with suspected asthma, aged 20-45 yrs. The subjects were from Reykjavik (Iceland), Uppsala and Goteborg (Sweden) and Antwerp (Belgium), and participated in the European Community Respiratory Health Survey. The investigation included a structured interview, methacholine challenge, skinprick tests and a questionnaire on sleep disturbances. Participants in Iceland and Sweden also estimated their sleep times and made peak expiratory flow (PEF) recordings during a period of 1 week. Asthma was defined as self-reported physician-diagnosed asthma with current asthma-related symptoms (n = 267). Difficulties inducing sleep (DIS) and early morning awakenings (EMA) were about twice as common, and daytime sleepiness 50% more common, in asthmatics compared with subjects without asthma. After adjusting for possible confounders, a positive association was found between asthma and: DIS (odds ratio (OR) = 1.8); EMA (OR = 2.0); daytime sleepiness (OR = 1.6); snoring (OR = 1.7); and self reported apnoeas (OR = 3.7). Allergic rhinitis, which was reported by 71% of subjects with asthma, was independently related to DIS (OR = 2.0) and daytime sleepiness (OR = 1.3). A significant correlation was found between the number of asthma-related symptoms and sleep disturbances (p < 0.001). Asthma is associated with decreased subjective quality of sleep and increased daytime sleepiness. Concurrent allergic rhinitis may be an important underlying cause of sleep impairment in asthmatic patients.
Effects of lung volume and thoracic gas compression on maximal and partial flow-volume curves
Authors: Pellegrino R , Confessore P , Bianco A , Brusasco V
Published: April 2003

Comparing isovolume flows, measured at the mouth during forced expiratory manoeuvres as started from maximal or partial lung inflation, is a means of assessing the effects of deep inhalation on airway calibre. The aim of this study was to investigate whether the assessment of the effect of deep inhalation during induced bronchoconstriction is influenced by the lung volume at which it is determined and by volume differences due to thoracic gas compression that occur during forced expiratory manoeuvres. Four healthy subjects and six subjects with mild-to-moderate asthma subjects performed partial and maximal forced expiratory manoeuvres in a flow-type body plethysmograph at control and during a methacholine (MCh) inhalation challenge. Mouth flow (V1) was plotted against both the expired volume (Vmo) and the simultaneous thoracic volume measured by plethysmography (Vpl) changes (V1-Vmo loop and V1-Vpl loop, respectively). The effects of deep inhalation were quantified by determining 1) the ration of maximal to partial expiratory flows (M/P) at 30, 40 and 50% of control forced vital capacity (FVC) both on V1-Vmo loops (M/Pmo) and V1-Vpl loops (M/Ppl) at control and at MCh end-point; and 2) the slope of the linear regression of maximal vs partial expiratory flows at 30, 40 and 50% of control FVC both on V1-Vmo loops (MPst,mo) and V1-Vpl loops (MPsl,pl) over the entire challenge. At control, M/Pmo and M/Ppl were similar. At MCh end-point, M/Pmo and M/Ppl increased more than twofold (p < 0.002), with M/Pmo consistently exceeding M/Ppl (p < 0.001). In addition, both M/Pmo and M/Ppl varied inversely with lung volume (p < 0.001). By contrast, MPsl,mo and MPsl,pl were not significantly different from each other (p = 0.8), and were also similar at the different lung volumes (p = 0.6). We conclude that during induced bronchoconstriction, the bronchodilation following a deep inhalation, expressed as maximal to partial flow ratio is dependent both on lung volume and volume differences due to thoracic gas compression. The use of expired flow and volume measurements may lead to a small but systematic overestimation of the bronchodilator effect of a deep inhalation. On the contrary, maximal to partial flow slope is insensitive either to lung volume or volume differences due to thoracic gas compression and can, therefore, be fairly determined from expired flow-volume loops.
Endobronchial hamartoma presenting as massive haemoptysis
Authors: Sharkey RA , Mulloy EM , O'Neill S
Published: April 2003

A 53 year old man presented with massive haemoptysis, and chest radiography revealed a left suprahilar mass. At thoracotomy he was found to have a modular mass in the left upper lobe, which was attached to a peripheral bronchus. Histology confirmed a pulmonary hamartoma.
Diminished production of anti-inflammatory mediators during neutrophil apoptosis and macrophage phagocytosis in chronic granulomatous disease (CGD)
Authors: Brown Joanne R , Goldblatt David , Buddle Joanna , Morton Louise , Thrasher Adrian J
Published: April 2003

Genetic defects in the phagocyte nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase enzyme system result in chronic granulomatous disease (CGD). In addition to recurrent, life-threatening infections, patients with CGD frequently present with sterile inflammatory complications, suggesting that NADPH-oxidase deficiency predisposes to these responses in the absence of persistent microbial infection. The mechanisms involved in the aberrant, inflammatory process are unknown. In this study, we have shown that neutrophils isolated from CGD patients, which are more resistnt to spontaneous apoptosis in vitro, also produce significantly less of the anti-inflammatory mediator cyclopentenone prostaglandin D2 (PGD2). In addition, during phagocytosis of opsonized and nonopsonized apoptotic targets, CGD macrophages are severely compromised in their ability to produce PGD2 and transforming growth factor-β (TGF-β). We suggest that delayed apoptosis of inflammatory cells, such as neutrophils and deficient production of the anti-inflammatory mediators PGD2 and TGF-β during macrophage clearance of apoptotic debris and invading pathogens, contributes to persistence of inflammation in CGD.