bluuebunny/crossref_metadata_2025 huggingface dataset:
Deposition and clearance of inhaled 18FDG powder in patients with chronic obstructive pulmonary disease
Authors: Yanai M , Hatazawa J , Ojima F , Sasaki H , Itoh M , Ido T
Published: November 2002

As freon is limited in its use as a generator for aerosol inhalation, powder particles are used as an alternative for inhalation therapy. The pulmonary deposition and clearance of inhaled powder particles was studied by positron emission tomography (PET) in ten patients with chronic obstructive pulmonary disease (COPD) and in five normal controls. The powder, 5 microm in mean diameter, was water soluble and labelled with 2-deoxy-2-[18F]-fluoro-D-glucose (18FDG). Powder inhalation was done with single deep inspiration from residual volume to total lung capacity. The initial deposition ratio in the right or left lung field to total inhaled dose, measured by an anteroposterior rectilinear scan, did not differ between normals and COPD patients. Ratios of radioactivity detected within the central and peripheral regions (the central to peripheral ratio) measured by the PET scan was not significantly different between COPD patients (4.8+/-2.6, mean+/-SD) and normals (2.6+/-0.8, mean+/-SD). However, the regional powder deposition in peripheral lung fields measured by the PET scan was significantly more uneven in COPD patients than in normal patients. The clearance rate of 18FDG, defined as the retention ratio of 18FDG activity to the initially deposited 18FDG at 60 and 120 min after inhalation, in the trachea, large bronchi or peripheral lung fields measured by tomographic scan showed a wider variation in COPD patients than in normals. To conclude, inhaled powder tended to be deposited more centrally and was distributed more unevenly in the peripheral lung in chronic obstructive pulmonary disease patients than in normals. This could be a limitation of powder inhalation used for therapy in chronic obstructive pulmonary disease patients.
Noninvasive pressure support ventilation in COPD patients with postextubation hypercapnic respiratory insufficiency
Authors: Hilbert G , Gruson D , Portel L , Gbikpi-Benissan G , Cardinaud JP
Published: November 2002

Patients with chronic obstructive pulmonary disease (COPD) who have been intubated and mechanically ventilated may prove difficult to wean. Noninvasive ventilation may be used in an attempt to avoid new endotracheal intubation. The efficacy of administration of noninvasive pressure support ventilation was evaluated in 30 COPD patients with postextubation hypercapnic respiratory insufficiency, compared with 30 historically matched control patients who were treated conventionally. Patients were included in the study if, within 72 h postextubation, they presented with respiratory distress, defined as the combination of a respiratory frequency >25 breaths x min(-1), an increase in the arterial carbon dioxide tension (Pa,CO2) of at least 20% compared with the value measured after extubation, and a pH <7.35. Noninvasive pressure support ventilation was effective in correcting gas exchange abnormalities. The use of noninvasive ventilation significantly reduced the need for endotracheal intubation: 20 of the 30 patients (67%) in the control group required endotracheal intubation, compared with only six of the 30 patients (20%) in the noninvasive-ventilation group (p<0.001). In-hospital mortality was not significantly different between the two groups, but the mean duration of ventilatory assistance for the treatment of the postextubation distress, and the length of intensive care unit stay related to this event, were both significantly shortened by noninvasive ventilation (p<0.01). In conclusion, noninvasive ventilation may be used in the management of patients with chronic obstructive pulmonary disease and postextubation hypercapnic respiratory insufficiency.
References values for forced spirometry. Group of the European Community Respiratory Health Survey
Authors: Roca J , Burgos F , Sunyer J , Saez M , Chinn S , Anto JM , Rodriguez-Roisin R , Quanjer PH , Nowak D , Burney P
Published: November 2002

The European Coal and Steel Community (ECSC) prediction equations exemplify a significant effort carried out approximately 15 yrs ago to provide uniform standards for lung function testing, but this set of equations has not been properly validated as yet. The present study evaluates the ECSC reference values and four other sets of prediction equations, using spirometric data collected in 12,900 nonasthmatic subjects (43% lifetime nonsmokers and 36% active smokers) aged 20-44 yrs from the European Community Respiratory Health Survey (ECRHS). Standardized spirometric measurements were obtained using a common protocol in 34 centres in 14 countries. For each prediction equation, the prediction deviations (i.e. observed minus predicted value) for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were examined for the whole study population and for each centre. For the age range included, the errors about the ECSC equations showed the most prominent underestimation of both predicted FVC (+355 and +360 mL on average in males and females, respectively) and predicted FEV1 (+211 and +200 mL, respectively) among the five studies examined. As expected, FVC and FEV1 in active smokers from the ECRHS were significantly lower than in lifetime nonsmokers (each p<0.01). We conclude that the present European recommendations on lung function reference values should be reconsidered, but further data for nonsymptomatic subjects above the age of 44 yrs are needed.
Respiratory symptoms, lung function and use of health services among unemployed young adults in Spain. Spanish Group of the European Community Respiratory Health Survey
Authors: Kogevinas M , Anto JM , Tobias A , Alonso J , Soriano J , Almar E , Muniozguren N , Payo F , Pereira A , Sunyer J
Published: November 2002

The association of respiratory symptoms, lung function and use of health services with employment status was examined in Spain, a country with a high rate of unemployment. A population sample comprising 179 unemployed and 1,868 employed subjects aged 20-44 yrs in 1993, was randomly selected from a base population of about 170,000 people in five urban and rural areas of Spain. Subjects completed a questionnaire on respiratory symptoms, sociodemographic and lifestyle factors, occupational exposure and use of health services, and performed a forced spirometry, a methacholine challenge test and blood tests. Unemployed subjects had a higher risk of simple chronic bronchitis (odds ratio=2.06, 95% confidence interval 1.30-3.24) and of bronchitis-type symptoms, than those who were employed. These risks were, in part, due to the higher prevalence of smoking, poorer housing and prior occupational exposures among unemployed than among employed people. Smaller differences were found between employed and unemployed subjects for asthma-type symptoms, atopia and lung function tests. Use of health services among subjects with respiratory symptoms was similar among employed and unemployed subjects, except that the latter consistently reported less frequent contact with specialized practitioners. Unemployed subjects had a higher risk of bronchitis-type symptoms than employed subjects. In Spain's national, free-access healthcare system, the differential use of specialized health services by employment status is likely to imply differences in the characteristics of the healthcare provided.
Relationship between external resistances, lung function changes and maximal exercise capacity
Authors: Melissant CF , Lammers JW , Demedts M
Published: November 2002

In upper airway obstruction (UAO) the relationship between the degree of obstruction, exercise limitation and lung function indices is not well established. Therefore, we investigated in nine healthy subjects (age 36+/-9 yrs) the effects of two added resistances at the mouth (R1 = added resistance with 7.8 mm diameter; R2 = 5.7 mm) on forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), airway resistance (Raw) and maximal breathing capacity (measured during 15 s = measured maximum breathing capacity (MBCm); calculated as FEV1x37.5 = calculated maximum breathing capacity (MBCc)) on the one hand, and maximum exercise capacity (W'max), minute ventilation (V'E) and CO2 elimination (V'CO2) on the other. We found that R1 had almost no influence on FEV1 but decreased PEF by approximately 35% and increased Raw by almost 300%; it decreased W'max by merely approximately 10% while maximal exercise ventilation (V'Emax) was only 65% of control and only reached approximately 40% MBCc and approximately 70% MBCm; yet V'E and V'CO2 were significantly reduced at high exercise levels indicating hypoventilation. With R2, FEV1 was reduced by 25% and PEF by 55%, and Raw was increased by 600%; W'max was approximately 60% of control, V'Emax was only 35% of control and reached approximately 30% MBCc and approximately 60% MBCm, V'E was already reduced at moderate exercise levels. We conclude that: 1) an upper airway obstruction of 6 mm diameter (but not of 8 mm) had a marked influence on maximum exercise capacity due to hypoventilation; 2) calculated maximum breathing capacity markedly overestimated measured maximum breathing capacity because the forced expiratory volume in one second is an insensitive index of upper airway obstruction and because it does not take inspiratory flow limitation into account; and 3) a 10% decrease in maximum exercise capacity was linearly related with a 7% decrease in the forced expiratory volume in one second and a 150% increase in airway resistance. A 10% decrease in maximal exercise ventilation was related to a 8.5% decrease in peak expiratory flow and 9% decrease in measured maximum breathing capacity.
The effect of octreotide on breathing and the ventilatory response to CO2 in conscious dogs
Authors: Cao K , Grunstein RR , Ho KY , Sullivan CE
Published: November 2002

It has been reported that injection of somatostatin into the brain-stem will lead to apnoea in animals. The aim of this study was to determine whether peripheral administration of octreotide, an analogue of somatostatin, could influence the control of breathing. We measured the tidal volume, respiratory rate and ventilatory response to CO2, before and after the intravenous injection of two dose levels of octreotide (0.1 mg and 0.5 mg) or saline in four conscious adult dogs. Injection of octreotide altered the breathing pattern with a mean decrease in the respiratory frequency of 23% (p<0.05) and an increase in the tidal volume by 16% (p<0.05), resulting in no net change in ventilation. The normal value of the ventilatory response to CO2 ranged between 1.0-3.2 L x min(-1) x mmHg(-1), with a minor variance within each dog but a significant difference amongst the four dogs (p<0.05). No significant change in the ventilatory response to CO2 was observed after octreotide. We conclude that intravenous octreotide alters the pattern of breathing but preserves minute ventilation; peripheral administration of octreotide does not influence the ventilatory response to CO2.
Expiratory valves used for home devices: experimental and clinical comparison
Authors: Lofaso F , Aslanian P , Richard JC , Isabey D , Hang T , Corriger E , Harf A , Brochard L
Published: November 2002

A bench study followed by a clinical trial were performed to evaluate the mechanical characteristics of five (commercially available) expiratory valves used for home ventilators, as well as the potential clinical impact of differences between these valves. In the in vitro study, expiratory valve resistance was evaluated under unvarying conditions, whereas dynamic behaviour was evaluated by calculating the imposed expiratory work of breathing during a simulated breath generated by a lung model. Differences in resistance and imposed expiratory work of up to twofold and 150%, respectively, were found across valves. We then conducted a randomized crossover clinical study to compare the effects of the least resistive (Bennett) and most resistive expiratory valves (Peters) in 10 intubated patients receiving pressure support ventilation. There were no significant differences regarding blood gases or respiratory parameters except for the oesophageal pressure-time product (PTPoes), which was significantly increased by the Peters valve (236+/-113 cmH2O x s x min(-1) versus 194+/-90 cmH2O x s x min(-1)). An analysis of individual responses found that the Peters valve induced substantial increases in intrinsic positive end-expiratory pressure (PEEP), PTPoes, and expiratory activity in those patients with the greatest ventilatory demand. In conclusion, differences between home expiratory valve resistances may have a clinically relevant impact on the respiratory effort of patients with a high ventilatory demand.
Magnetic resonance (MR) imaging of the chest: state-of-the-art
Authors: Bittner RC , Felix R
Published: November 2002

To date, magnetic resonance (MR) is established as an imaging modality in the diagnosis of chest diseases. Because of its excellent distinction of vessels and soft tissue, MR can be performed as the primary imaging procedure before computed tomography in patients with suspected vascular lesions, mediastinal masses, hilar lesions, and pathological changes of the pleura and the chest wall. In these cases, MR is able to provide all the necessary diagnostic information. In other patients, a limited number of MR images may be helpful in cases of equivocal or confusing CT or clinical findings. More detailed information can be obtained, using surface coils or special imaging sequences, i.e. high resolution MR images of the pleura or angiographic images of mediastinal and pulmonary vasculature. From a clinical viewpoint, the most important task for thoracic magnetic resonance nowadays is the pretherapeutic evaluation of intrathoracic masses, the differential diagnosis of benign versus malignant lesions, and the accurate documentation of tumour extent in malignancies including three-dimensional-display to improve surgical or radiation planning. Future directions in thoracic magnetic resonance will be predominantly influenced by postprocessing approaches, specialized imaging techniques, and magnetic resonance-guided interventional applications.
Serial sputum cell counts in the management of chronic airflow limitation
Authors: Parameswaran K , Pizzichini MM , Li D , Pizzichini E , Jeffery PK , Hargreave FE
Published: November 2002

This case study illustrates the usefulness of serial induced sputum cell counts from cytospins to investigate the nature of airway inflammation in a patient presumed to have prednisone-dependent asthma for 30 yrs. She had bronchiectasis and chronic airflow limitation. Exacerbations of breathlessness were associated with an increase in chronic airflow limitation with little or no sputum. Induced sputum showed elevated total cell and neutrophil counts at each exacerbation with no increase in the proportion of eosinophils. Pathogenic bacteria were cultured at each flare-up. The dose of prednisone was reduced progressively and each exacerbation was treated with an appropriate antibiotic without increasing the dose of prednisone, as was the case previously. The infections were associated with bronchiectasis of the right upper lobe which was removed. Examination of the specimen confirmed neutrophilic infiltration and did not show the usual airway structural changes of asthma. These results provide further evidence of the value of sputum cell counts in practice, in this case to prevent overtreatment with prednisone in a patient with recurrent deteriorations in airflow which were due to recurrent infections.
Lung abscess complicating chondromas in Carney's syndrome
Authors: Convery RP , Grainger AJ , Bhatnagar NK , Scott D , Bourke SJ
Published: November 2002

Carney's syndrome consists of a combination of three rare tumours: gastric leiomyosarcoma, pulmonary chondroma and catecholamine-secreting paraganglioma. We describe a young woman with Carney's syndrome, who developed a lung abscess, due to obstruction of a bronchus by a chondroma, 11 yrs after having had a partial gastrectomy for a leiomyosarcoma.
Interstitial lung disease more than 40 years after a 5 year occupational exposure to talc
Authors: Gysbrechts C , Michiels E , Verbeken E , Verschakelen J , Dinsdale D , Nemery B , Demedts M
Published: November 2002

A 62 yr old woman was initially diagnosed with sarcoidosis until a thoracoscopic biopsy revealed the presence of numerous birefringent particles in fibrotic areas of the centrilobular lung zones. These particles were examined by electron microscopy and X-ray spectrometry and characterized as impure talc. Further inquiry into her occupational history revealed that she had worked from the age of 14-18 yrs in a factory making rubber hoses, where she had had an intense exposure to talc. There was no evidence of silicosis or asbestosis, and other significant causes of interstitial lung disease were excluded. This case emphasizes the importance of a thorough occupational history, which may reveal a remote and forgotten exposure to a significant cause of interstitial lung disease. Although this presentation of talcosis is unusual, this case suggests that even a relatively short, but presumably intense exposure to talc more than 40 yrs previously may be a cause of progressive lung fibrosis.
Guidelines for mineral fibre analyses in biological samples: report of the ERS Working Group. European Respiratory Society
Authors: De Vuyst P , Karjalainen A , Dumortier P , Pairon JC , Monso E , Brochard P , Teschler H , Tossavainen A , Gibbs A
Published: November 2002

Microscopic techniques for analysing asbestos fibres in lung tissue and bronchoalveolar lavage have provided major information in the understanding of asbestos-related diseases. These analyses are increasingly applied for clinical work and medicolegal problems. Differences in sampling, preparation and counting techniques, definitions of reference populations and expression of results have caused major difficulties in comparing results from different laboratories. Therefore it appeared necessary to set a goal to harmonize these analyses between the European laboratories active in this field. This article summarizes the work of a European Respiratory Society working group with participation from nine European laboratories. The five main issues touched upon are: 1) definitions of control populations and reference levels; 2) sampling, preparation and analytical techniques; 3) asbestos fibres in lung tissues in different pathologies; 4) asbestos bodies in lung tissue, bronchoalveolar lavage and sputum; and 5) basis for the interpretation of fibres and asbestos bodies in biological samples. These guidelines indicate the crucial importance of several factors for the interpretation of the results; namely, adequate sampling, comparable analytical procedures and expression of the results, the use of well-defined reference populations, and a comprehensive understanding of the factors affecting the fibre retention and the dose-responses associated with the different asbestos-related diseases.
Transcriptional Regulation of the Epiregulin Gene in the Rat Ovary
Authors: Sekiguchi Toshio , Mizutani Tetsuya , Yamada Kazuya , Yazawa Takashi , Kawata Hiroko , Yoshino Miki , Kajitani Takashi , Kameda Takashi , Minegishi Takashi , Miyamoto Kaoru
Published: November 2002

Ovarian follicular development is initiated by FSH secreted from the pituitary gland. The FSH-induced follicular development involves granulosa cell proliferation and differentiation. We demonstrated that a growth factor of epidermal growth factor (EGF) family epiregulin was rapidly induced in the primary culture of rat ovarian granulosa cells by FSH within 1 h. Epiregulin gene expression was also observed in granulosa cells of antral ovarian follicles from pregnant mare’s serum gonadotropin-primed rats in vivo. To analyze the regulation of gene expression of epiregulin, we isolated and characterized the rat epiregulin gene of 22.1 kb, including 3.8 kb of 5′-upstream region as well as all five exons and four introns. We determined the transcriptional start site of rat epiregulin gene by primer extension analysis and then characterized the upstream promoter region of the gene. By using a luciferase reporter system, deletion and mutation analyses of rat epiregulin gene promoter region revealed that 125 bp upstream of transcriptional start site was essential, and that two CT boxes and one GT box within this region were important for the gene expression. We also demonstrated by EMSAs that Sp1/Sp3 proteins were involved in the epiregulin gene expression via the upstream sequence. Involvement of Sp1/Sp3 was also demonstrated that transfection of Sp1 or Sp3 expression plasmids dramatically increased the epiregulin gene promoter activities about 90- or 7.9-fold, respectively, in Drosophila SL2 cells that lack endogenous Sp family proteins. Such an increase in the promoter activity was also observed in mammalian cells when NIH-3T3 cells were used. In conclusion, we demonstrated here for the first time that EGF-type growth factor epiregulin is rapidly and strongly induced in the ovarian granulosa cells by FSH stimulation, and that two CT boxes and one GT box present in the upstream region are essential for the promoter activity of rat epiregulin. We also demonstrated that Sp family members play crucial roles in the epiregulin promoter activity through the CT boxes. The restricted and hormonally regulated expression of epiregulin in the rat ovarian granulosa cells may correspond to the physiological relevance of this peptide growth factor to the FSH-induced ovarian follicular growth and maturation.
Direct Response of the Murine Prostate Gland and Seminal Vesicles to Estradiol
Authors: Bianco Joseph John , Handelsman David J. , Pedersen John Stuart , Risbridger Gail Petuna
Published: November 2002

In the prostate, testosterone action depends on conversion to bioactive metabolites dihydrotestosterone and 17β-estradiol (E2) via the 5α-reductase and aromatase enzymes, respectively. Exogenous estrogen inhibits prostate growth by indirect effects caused by suppression of pituitary gonadotropins and testicular testosterone output, but direct effects are less well known. Direct effects of estrogens were evaluated using the hypogonadal (hpg) mouse model, which has postnatal deficiency in gonadotropins and testosterone but remains hormone sensitive. Mature hpg mice were implanted sc with implants filled with E2. After 6 wk, prostate lobe [anterior prostate (AP) and ventral prostate (VP)] and seminal vesicle (SV) organ volumes were significantly increased (P < 0.05) but remained smaller than wild-type mice. Analysis of the relative volumes (the proportional composition) of each tissue compartment in these organs showed significant increases in cellular and luminal volumes (P < 0.05) in AP (but not VP) and in SVs. Stromal fibroblasts proliferated, whereas smooth muscle cells were reduced in the AP and SVs. In the epithelia, basal cells proliferated and became metaplastic in the AP and VP. In the AP, luminal debris accumulated, together with an inflammatory response, but there was no evidence of malignant changes. The current study unequivocally demonstrates direct proliferative responses to E2 in the hpg mouse AP and VP lobes and SVs, characterized by discrete lobe-specific changes, including smooth-muscle regression, fibroblast proliferation, inflammation, and basal epithelial cell proliferation and metaplasia.
Heparin-Binding Epidermal Growth Factor-Like Growth Factor Stimulates Androgen-Independent Prostate Tumor Growth and Antagonizes Androgen Receptor Function
Authors: Adam Rosalyn M. , Kim Jayoung , Lin Jianqing , Orsola Anna , Zhuang Liyan , Rice Dana C. , Freeman* Michael R.
Published: November 2002

Peptide growth factors have been implicated in progression of prostate cancer (PCa) to the androgen-independent state; however, much of the evidence linking diffusible mitogens and survival factors to this process remains circumstantial. Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a prostate stroma-derived factor, promotes survival, proliferation, and neuroendocrine differentiation of androgen-dependent LNCaP PCa cells in vitro. To test whether sustained exposure to HB-EGF can confer an androgen-independent phenotype, we generated stable populations of LNCaP cells that express constitutively a secreted form of HB-EGF (LNCaP/sHB). LNCaP/sHB cells proliferated more rapidly under androgen-depleted conditions in vitro and formed larger tumors with higher frequency in intact and castrated severe combined immunodeficient mice, in comparison to control cells. LNCaP/sHB tumors also expressed higher levels of the neuroendocrine marker, neuron-specific enolase, compared with control tumors. In castrates, increased neuron-specific enolase expression in LNCaP/sHB tumors was associated with reduced androgen receptor (AR) levels. In vitro, AR protein levels were reduced in LNCaP/sHB cells, and in transient transfection assays using an androgen-responsive promoter (mouse mammary tumor virus-long terminal repeat), LNCaP/sHB cells showed reduced sensitivity to dihydrotestosterone compared with controls. This is the first demonstration that continuous exposure of AR-positive PCa cells to a single growth factor can promote an androgen-independent phenotype in vivo. These findings also emphasize the potential role of pathways other than the AR axis in acquisition of androgen independence.
Minireview: Estrogen and Mouse Models of Atherosclerosis
Authors: Hodgin Jeffrey B. , Maeda Nobuyo
Published: November 2002

The use of hormone replacement therapy for coronary heart disease prevention in humans has been an area of intense controversy. The atheroprotective qualities of estrogens have been challenged recently by several negative results of randomized clinical trials in postmenopausal women. However, the inhibitory effects of estrogens on atherogenesis are well documented in numerous animals, including atherosclerotic mouse models, but the detailed mechanisms of this protection are not understood. In this minireview, we will focus on the considerable success that has been achieved in demonstrating the atheroprotective effects of 17β-estradiol in apolipoprotein E and low-density lipoprotein receptor-deficient mice and the use of these atherosclerotic mouse models in pharmacological and genetic study designs to investigate antiatherogenic mechanisms of estrogens. Mouse models of atherosclerosis should prove beneficial to understanding the cellular and molecular mechanisms of estrogen-mediated atheroprotection and aid the development of improved therapies to confer the benefits and reduce the risks associated with hormone replacement therapy.
Multivariate least squares and its relation to other multivariate techniques
Authors: Lipovetsky Stan , Tishler Asher , Conklin W. Michael
Published: November 2002

We consider multivariate least squares (LS) for the estimation of the connection between two data sets and show how LS is related to other multivariate techniques regularly used to analyse large data sets. LS methods are shown to be equivalent, or similar, to principal components, canonical correlations and its modifications, including a variant of the partial LS. LS approach provides a convenient unified framework for a general description and comparison of various multivariate methods, facilitates their understanding, and helps to identify their usefulness for various real‐world applications. As an example we estimate and discuss the relations between data sets containing managerial variables and success measures. Copyright © 2002 John Wiley & Sons, Ltd.
Optimum inspection under competing risks with proportional hazards
Authors: Badía F. G. , Berrade M. D. , Campos Clemente A.
Published: November 2002

In this work, we present an inspection policy so as to detect the failures of a single‐unit system subject toNlatent causes of failure when the time and cause of failure are independent. It is supposed that inspections may fail and give an erroneous result. The optimum inspection time which minimizes cost per unit of time for an infinite time span is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
The application of neural networks to predict abnormal stock returns using insider trading data
Authors: Safer Alan M.
Published: November 2002

Until now, data mining statistical techniques have not been used to improve the prediction of abnormal stock returns using insider trading data. Consequently, an investigation using neural network analysis was initiated. The research covered 343 companies for a period of 4½ years. Study findings revealed that the prediction of abnormal returns could be enhanced in the following ways: (1) extending the time of the future forecast up to 1 year; (2) increasing the period of back aggregated data; (3) narrowing the assessment to certain industries such as electronic equipment and business services and (4) focusing on small and midsize rather than large companies. Copyright © 2002 John Wiley & Sons, Ltd.
A bootstrap procedure for mixture models: applied to multidimensional scaling latent class models
Authors: Winsberg Suzanne , De Soete Geert
Published: November 2002

A bootstrap procedure useful in latent class, or more general mixture models has been developed to determine the sufficient number of latent classes or components required to account for systematic group differences in the data. The procedure is illustrated in the context of a multidimensional scaling latent class model, CLASCAL. Also presented is a bootstrap technique for determining standard errors for estimates of the stimulus co‐ordinates, parameters of the multidimensional scaling model. Real and artificial data are presented. The bootstrap procedure for selecting a sufficient number of classes seems to correctly select the correct number of latent classes at both low and high error levels. At higher error levels it outperforms Hope's (J. Roy. Statist. Soc. Ser B1968;30: 582) procedure. The bootstrap procedures to estimate parameter stability appear to correctly re‐produce Monte Carlo results. Copyright © 2002 John Wiley & Sons, Ltd.
Luminescence Literature
Authors: Kricka L.J , Stanley P.E
Published: November 2002

The journal provides comprehensive literature searches on all aspects of luminescence which will be published in most issues. These lists have been produced regularly since 1986—some by year and some by specialized topic. This survey of papers on green fluorescent protein and imaging is drawn from the 2000 literature and covers reagents, assay development and validation, and applications and supplements the previous survey (J. Biolumin. Chemilumin. 1997; 12: 113–34).

The 2000 Literature

Compiled by L. J. Kricka (kricka@mail.med.upenn.edu) and P. E. Stanley (stanley@lumiweb.com)
Studies on the chemiexcitation step in peroxyoxalate chemiluminescence using steroid‐substituted activators
Authors: Silva Sandra M. , Wagner Kerstin , Weiss Dieter , Beckert Rainer , Stevani Cassius V. , Baader Wilhelm J.
Published: November 2002

The peroxyoxalate reaction is utilized in a wide variety of analytical applications; however, its mechanism is still not very well understood, especially with respect to the excitation step, where the ‘chemical energy’ is transformed into ‘excitation energy’. This base‐catalysed reaction of activated oxalic phenyl esters with hydrogen peroxide in the presence of highly fluorescent aromatic hydrocarbons with low oxidation potentials is the only known chemiluminescence system for which exists experimental evidence for the occurrence of the intermolecular chemically initiated electron exchange luminescence (CIEEL) mechanism of proven high efficiency for excited state formation. We report here the singlet quantum yields and relative rate constants of the excitation step (kCAT/kD), obtained in the peroxyoxalate reaction, utilizing steroid‐substituted oxazolinylidenes as activators. In agreement with the CIEEL mechanism, a linear correlation of ln(kCAT/kD) with the oxidation potential of the activators is obtained, and the singlet quantum yields can be rationalized in terms of the free energy balance of the back electron transfer, leading to the formation of the activator's excited state. Thus, these results contribute to the experimental validation of the widely employed, thus still controversial, CIEEL mechanism. Copyright © 2002 John Wiley & Sons, Ltd.
Hydromechanical stimulation of bioluminescent plankton
Authors: Blaser Stefan , Kurisu Futoshi , Satoh Hiroyasu , Mino Takashi
Published: November 2002

The response of the bioluminescent dinoflagellate Pyrocystis fusiformis was investigated for different hydraulic conditions (‘hydromechanical stimulation’). Pipe flow and oscillating shear produced luminescence, whereas changes in hydrostatic pressure were not stimulating. More intense fluid motion led to higher intensity, mainly due to a higher probability of cell response. The organism was also able to emit light in a glucose–salt mixture. The experiments suggest that the cells are effectively stimulated if the flow conditions change in time. Copyright © 2002 John Wiley & Sons, Ltd.
Influence of the storage time and the method of stimulation on whole blood chemiluminescence
Authors: Podraza Wojciech , Gonet Bolesław , Kordek Agnieszka
Published: November 2002

The ultra‐weak light, chemiluminescence (CL), of stimulated leukocytes is a well‐known phenomenon. Parameters of this CL are modified by many factors including laboratory procedures. The order of stimulation and enhancement (two possibilities) and two concentrations of luminol create four types of procedure, which were accomplished in five sample storage ‘time points’. We received the strongest signals of CL using higher concentrations of luminol (and DMSO), but only when stimulation (FMLP) was used before enhancement (luminol); luminol used before FMLP strongly inhibited CL. For lower luminol concentration (and DMSO), the order of stimulation and enhancement was of no importance. There were comparable but weaker signals of CL in this case. We received stronger signals with storage time for all procedures. It may be dependent on the priming of phagocytes by releasing cell factors. Stimulation (FMLP) before enhancement (luminol) eliminates the inhibitory effect of DMSO on CL. Copyright © 2002 John Wiley & Sons, Ltd.
Orthogonal signal correction: algorithmic aspects and properties
Authors: Li Baibing , Morris A. Julian , Martin Elaine B.
Published: November 2002

The objective of this paper is to present a modified algorithm for the orthogonal signal correction (OSC) filter based on the approaches proposed by Wold, Antti, Lindgren and Öhman (Chemometrics Intell. Lab. Syst. 1998; 44: 175–185) and Fearn (Chemometrics Intell. Lab. Syst. 2000; 50: 47–52). An OSC filter consists of a trio of building blocks: weights, components and loadings, $\font\mathbfit=cmmib10\def\bfit#1{\hbox{\mathbfit #1}} {\bf \{w_{{\bfit j}}, t_{{\bfit j}}, p_{{\bfit j}}\}_{{\bfit j}=1}^{{\bfit A}}}$. The original OSC filter of Wold et al. was based on the framework of the non‐linear iterative partial least squares (NIPALS) algorithm. Adopting this approach enabled the mathematical justification for the selection of the loading vectors p
j and components t
j, but there was no theoretical foundation for the selection of w
j. In contrast, the approach of Fearn described an objective function for the selection of the weight vectors w
j, but in this case there is no theoretical justification for either p
j or t
j. Combining both approaches, within a NIPALS framework, enables a clear theoretical basis for the selection of all three building blocks to be established. A number of orthogonal and optimal properties of the NIPALS‐based OSC algorithm, although previously reported, are also theoretically proven. Finally, it is shown that the modified OSC algorithm is equivalent to Fearn's OSC but is interpretable as a consequence of it being presented from a NIPALS perspective. This enables the possible extension of OSC to dynamic and non‐linear systems. Copyright © 2002 John Wiley & Sons, Ltd.
Bayesian principal component analysis
Authors: Nounou Mohamed N. , Bakshi Bhavik R. , Goel Prem K. , Shen Xiaotong
Published: November 2002

Principal component analysis (PCA) is a dimensionality reduction modeling technique that transforms a set of process variables by rotating their axes of representation. Maximum likelihood PCA (MLPCA) is an extension that accounts for different noise contributions in each variable. Neither PCA nor any of its extensions utilizes external information about the model or data, such as the range or distribution of the underlying measurements. Such prior information can be extracted from measured data and can be used to greatly enhance the model accuracy. This paper develops a Bayesian PCA (BPCA) modeling algorithm that improves the accuracy of estimating the parameters and measurements by incorporating prior knowledge about the data and model. The proposed approach integrates modeling and feature extraction by simultaneously solving parameter estimation and data reconciliation optimization problems. Methods for estimating the prior parameters from available data are discussed. Furthermore, BPCA reduces to PCA or MLPCA when a uniform prior is used. Several examples illustrate the benefits of BPCA versus existing methods even when the measurements violate the assumptions about their distribution. Copyright © 2002 John Wiley & Sons, Ltd.
Delivery of hyper‐interleukin‐6 to the injured spinal cord increases neutrophil and macrophage infiltration and inhibits axonal growth
Authors: Lacroix Steve , Chang Leon , Rose‐John Stefan , Tuszynski Mark H.
Published: November 2002

Cytokine growth factors of the interleukin (IL)–6 family have recently been shown to play an important role in central nervous system (CNS) development, repair, and inflammation. These cytokines, which interact via specific membrane receptors, share a signal‐transducing receptor subunit, glycoprotein 130 (gp130). Gp130 is expressed by motoneurons in the gray matter of the rat spinal cord and by several brainstem nuclei that project to the spinal cord including the red, reticular, and vestibular nuclei. In this study, we examined whether stimulation of gp130 signaling, with the use of grafts of fibroblasts genetically modified to deliver the fusion protein, hyper‐IL‐6 (H‐IL‐6), which consists of the cytokine growth factor, IL‐6, and its α receptor, would elicit growth of injured spinal cord axons. Particular emphasis was placed on examining the potentially competing effects of growth factor versus proinflammatory influences of H‐IL‐6 in the context of spinal cord injury. Our results demonstrated that grafts delivering H‐IL‐6 induce a sixfold increase in the number of neutrophils (P < 0.05) and a twofold increase in the areas of spinal tissue occupied by macrophages and activated microglia (P < 0.01) at the site of the spinal cord injury when compared with control grafts. Of note, this augmentation in inflammatory cell infiltration correlated with a significant twofold increase in lesion size (P < 0.05) and a fourfold reduction in axonal growth (P < 0.01) at the lesion site. Thus, potential neurotrophic properties of this cytokine family of growth factors must be balanced against their inflammatory properties when considering therapeutic application to CNS injury. J. Comp. Neurol. 454:213–228, 2002. © 2002 Wiley‐Liss, Inc.
Spatial and temporal patterns of distribution of the gap junctional protein connexin43 during retinal regeneration of adult newt
Authors: Umino Yumiko , Saito Takehiko
Published: November 2002

Newts possess the ability to regenerate a functional retina after complete removal of the original retina. We performed immunoblot and immunohistochemical analyses of newt retinas at different stages of regeneration by using an antibody against a gap junction channel protein, connexin43 (Cx43). The specificity of the antibody was shown on immunoblots as well as immunohistochemical staining pattern in the normal retina. Punctate Cx43 immunolabeling was detected intensely between proliferating cell nuclear antigen–immunoreactive progenitor cells in the regenerating retinas, and the amount of this labeling tended to be prominent along both scleral and vitreal sides. The amount of Cx43 became less abundant as regeneration proceeded. This temporal loss of Cx43 during regeneration was also shown on the immunoblot analysis. Furthermore, the loss of Cx43 was observed in a spatial manner in the peripheral retina, where progenitor cells clustered at the ciliary marginal zone (CMZ) are adding new cells of all types in order toward the central retina. Immunolabeling often extended longitudinally throughout the retina when regenerating retinas became thick. Double immunolabeling with Cx43 and glial fibrillary acidic protein indicated the overlapping between the Cx43 and Müller cell processes. At the beginning of the synaptic formation, immunolabeling almost disappeared in the entire retina. However, in the completely regenerated retina, Cx43 reappeared in the distal end of Müller cells and pigment epithelial cells in the same pattern as in the normal retina. The above observations lead us to speculate that Cx43‐mediated gap junctions may play an important role in regenerating events. Possible roles of Cx43 during regeneration are discussed. J. Comp. Neurol. 454:255–262, 2002. © 2002 Wiley‐Liss, Inc.
Laminin chains in rat and human peripheral nerve: Distribution and regulation during development and after axonal injury
Authors: Wallquist Wilhelm , Patarroyo Manuel , Thams Sebastian , Carlstedt Thomas , Stark Birgit , Cullheim Staffan , Hammarberg Henrik
Published: November 2002

During nerve growth, axons are dependent upon contact with matrix components, such as laminins, for elongation, guidance, and trophic support. Semiquantitative in situ hybridization histochemistry and immunohistochemistry (IHC) were used to identify laminin chains in normal peripheral nerves, during postnatal development, after sciatic nerve transection (SNT), and after sciatic nerve crush (SNC). Laminin α2, α4, β1, β2, and γ1 chain mRNAs were all expressed at high levels in newborn rat sciatic nerves with declining levels during later developmental stages. At the adult stage, no laminin chain mRNA was detectable. Of interest, the mRNA levels for α4 chain declined faster than those for α2. After SNT, laminin α2, α4, β1, and γ1 mRNA levels were up‐regulated at the site of the injury, with the most profound reaction in the proximal nerve stump. Laminin α2 and α4 chains differed in that the mRNA levels of α4 were up‐regulated earlier and declined quicker, whereas α2 had a later onset, with high levels remaining even after 6 weeks. After SNC, there was an initial up‐regulation of the same laminin chain mRNAs as after SNT in the nerve, however, less intense, and at 6 weeks after SNC, all laminin mRNA levels studied had returned to normal. IHC of adult human normal and transected peripheral nerves stained positive for laminin α2, α4, β1, and γ1 chains in close relation to neurofilament labeled axons. Laminin α3, α4, α5, β1, β2, and γ1 chains were found in blood vessel‐like structures and α3, α4, α5, β2, and γ1 in the perineurium. These results and a previously published description of integrin regulation in spinal motoneurons suggest that both laminin‐2 (α2β1γ1) and laminin‐8 (α4β1γ1) are important for the postnatal nerve development and axonal regeneration after injury and that laminin‐8 may have important functions especially early postnatally and early after adult nerve lesion. J. Comp. Neurol. 454:284–293, 2002. © 2002 Wiley‐Liss, Inc.
Organization of the feedback pathway from striate cortex (V1) to the lateral geniculate nucleus (LGN) in the owl monkey (Aotus trivirgatus)
Authors: Ichida Jennifer M. , Casagrande Vivien A.
Published: November 2002

The function of the corticogeniculate feedback pathway from the striate cortex (V1) to the lateral geniculate nucleus (LGN) in primates is not well understood. Insight into possible function can be gained by studying the morphology and projection patterns of corticogeniculate axons in the LGN. The goal of this research was to examine how corticogeniculate axons innervate the functionally specific (e.g., parvocellular [P], magnocellular [M], and koniocellular [K]) and eye‐specific layers of the LGN. Pressure injections of biotinylated dextran were made into owl monkey V1, and the resulting labeled axons were reconstructed through serial sections of the LGN. All of the corticogeniculate axons, regardless of termination pattern, were thin with boutons en passant or at the ends of small stalks, as described in cats. Axons were found in all layers of the LGN, and two main patterns of innervation were observed. In the first pattern, axons terminated in individual M or P LGN layers. In the second pattern of innervation, axons terminated in pairs of functionally matched layers. Examples of this type were seen within pairs of M, P, or K layers. In most cases, both classes of axons contain arbors focused within the P or M layers but also had collateral side branches in neighboring K layers. Unlike corticogeniculate axons seen in the cat, corticogeniculate axons in the owl monkey maintained topographic innervation in the LGN layers that was consistent with receptive field sizes represented in V1. The patterns of layer projections along with the retinotopic match of corticogeniculate axons within the LGN suggest that in primates V1 can modulate activity in the LGN through functionally specific projections in a more tightly tuned retinotopic fashion than previously believed. J. Comp. Neurol. 454:272–283, 2002. © 2002 Wiley‐Liss, Inc.
Glial cell line‐derived neurotrophic factor and chronic electrical stimulation prevent VIII cranial nerve degeneration following denervation
Authors: Kanzaki Sho , Stöver Timo , Kawamoto Kohei , Prieskorn Diane M. , Altschuler Richard A. , Miller Josef M. , Raphael Yehoash
Published: November 2002

As with other cranial nerves and many CNS neurons, primary auditory neurons degenerate as a consequence of loss of input from their target cells, the inner hair cells (IHCs). Electrical stimulation (ES) of spiral ganglion cells (SGCs) has been shown to enhance their survival. Glial cell line‐derived neurotrophic factor (GDNF) has also been shown to increase survival of SGCs following IHC loss. In this study, the combined effects of the GDNF transgene delivered by adenoviral vectors (Ad‐GDNF) and ES were tested on SGCs after first eliminating the IHCs. Animal groups received Ad‐GDNF or ES or both. Ad‐GDNF was inoculated into the cochlea of guinea pigs after deafening, to overexpress human GDNF. ES‐treated animals were implanted with a cochlear implant electrode and chronically stimulated. A third group of animals received both Ad‐GDNF and ES (GDNF/ES). Electrically evoked auditory brainstem responses were recorded from ES‐treated animals at the start and end of the stimulation period. Animals were sacrificed 43 days after deafening and their ears prepared for evaluation of IHC survival and SGC counts. Treated ears exhibited significantly greater SGC survival than nontreated ears. The GDNF/ES combination provided significantly better preservation of SGC density than either treatment alone. Insofar as ES parameters were optimized for maximal protection (saturated effect), the further augmentation of the protection by GDNF suggests that the mechanisms of GDNF‐ and ES‐mediated SGC protection are, at least in part, independent. We suggest that GDNF/ES combined treatment in cochlear implant recipients will improve auditory perception. These findings may have implications for the prevention and treatment of other neurodegenerative processes. J. Comp. Neurol. 454:350–360, 2002. © 2002 Wiley‐Liss, Inc.