bluuebunny/crossref_metadata_2025 huggingface dataset:
Runoff generation and routing on artificial slopes in a Mediterranean–continental environment: the Teruel coalfield, Spain
Authors: Nicolau José‐Manuel
Published: August 2002

The aim of this study was to identify the mechanisms of runoff generation and routing and their controlling factors at the hillslope scale, on artificial slopes derived from surface coal mining reclamation in a Mediterranean–continental area. Rainfall and runoff at interrill and microcatchment scales were recorded for a year on two slopes with different substrata: topsoil cover and overburden cover. Runoff coefficient and runoff routing from interrill areas to microcatchment outlets were higher in the overburden substratum than in topsoil, and greater in the most developed rill network. Rainfall volume is the major parameter responsible for runoff response on overburden, suggesting that this substratum is very impermeable—at least during the main rainfall periods of the year (late spring and autumn) when the soil surface is sealed. In such conditions, most rainfall input is converted into runoff, regardless of its intensity. Results from artificial rainfall experiments, conducted 3 and 7 years after seeding, confirm the low infiltration capacity of overburden when sealed. The hydrological response shows great seasonal variability on the overburden slope in accordance with soil surface changes over the year. Rainfall volume and intensities (I30, I60) explain runoff at the interrill scale on the topsoil slope, where rainfall experiments demonstrated a typical Hortonian infiltration curve. However, no correlation was found at the microcatchment level, probably because of the loss of functionality of the only rill as ecological succession proceeded. The runoff generation mechanism on the topsoil slope is more homogeneous throughout the year. Runoff connectivity, defined as the ratio between runoff rates recorded at the rill network scale and those recorded at the interrill area scale in every rainfall event, was also greater on the rilled overburden slope, and in the most developed rill network. The dense rill networks of the overburden slope guarantee very effective runoff drainage, regardless of rainfall magnitude. Rills drain overland flow from interrill‐sealed areas, reducing the opportunity of reinfiltration in areas not affected by siltation. Runoff generation and routing on topsoil slopes are controlled by grass cover and soil moisture content, whereas on overburden slopes rill network density and soil moisture content are the main controlling factors. Copyright © 2002 John Wiley & Sons, Ltd.
Causes and consequences of fire‐induced soil water repellency
Authors: Letey J.
Published: August 2002

A wettable surface layer overlying a water‐repellent layer is commonly observed following a fire on a watershed. High surface temperatures ‘burn’ off organic materials and create vapours that move downward in response to a temperature gradient and then condense on soil particles causing them to become water repellent. Water‐repellent soils have a positive water entry pressure hp that must be exceeded or all the water will runoff. Water ponding depths ho that exceeds hp will cause infiltration, but the profile is not completely wetted. Infiltration rate and soil wetting increase as the value of ho/hp increases. The consequence is very high runoff, which also contributes to high erosion on fire‐induced water‐repellent soils during rain storms. Grass establishment is impaired by seeds being eroded and lack of soil water for seeds that do remain and germinate. Extrapolation of these general findings to catchment or watershed scales is difficult because of the very high temporal and spatial variabilities that occur in the field. Copyright © 2001 John Wiley & Sons, Ltd.
Fire, storms, and erosional events in the Idaho batholith
Authors: Meyer G. A. , Pierce J. L. , Wood S. H. , Jull A. J. T.
Published: August 2002

In late December 1996, the South Fork Payette River basin in west‐central Idaho experienced a prolonged storm that culminated on January 1, 1997, with intense rain on melting snow that triggered slide failures, producing debris flows and sediment‐charged floods. Failures occurred in saturated, cohesionless, grussy colluvium derived from weathered Idaho batholith granitic rocks. Many failures along the South Fork Payette River originated in ponderosa pine forests burned in the 1989 stand‐replacing Lowman fire. An example is the 0·49 km2 ‘Jughead’ Creek basin, where a single large colluvial failure produced almost 40% of the total volume eroded from the basin and generated a massive and rapid debris flow. Failures also occurred in steep, unburned, and unforested drainages such as Hopkins Creek. In this south‐facing 0·58 km2 basin, 15 colluvial hollows failed, but no single failure produced more than 10% of the total eroded volume. Sediment transport in Hopkins Creek occurred by prolonged sediment‐charged sheetflooding. Despite vegetation differences, sediment yields from the geomorphically similar Hopkins Creek (∼42 000 Mg km−2) and Jughead Creek (∼44 000 Mg km−2) basins were quite similar. These 1997 erosion events are equivalent to several thousand years of sediment yield at low rates (2·7–30 Mg km2 year−1) measured by short‐term sediment trapping and gauging in Idaho batholith watersheds. If similar large events were solely responsible for sediment export, recurrence intervals (RIs) of several hundred years would account for higher sediment yields averaged over ∼104 year from Idaho batholith watersheds. Dating of small fire‐induced sheetflooding events in an early Holocene tributary junction fan of Jughead Creek indicates that frequent small sedimentation events (RI≈33–80 year) occurred between 7400 and 6600 cal year BP, with an average yield not greatly exceeding 16 Mg km−2 year−1. Compared with the Holocene average, erosion rates during that 800 year period were unusually low, suggesting that sediment yields have not been constant over time, and that climatic variations and related fire regime changes may exert a strong influence on the probability of major erosional events. Copyright © 2001 John Wiley & Sons, Ltd.
Incidence and mortality from stomach cancer in Japan, Slovenia and the USA
Authors: Lambert René , Guilloux Agathe , Oshima Akira , Pompe‐Kirn Vera , Bray Freddie , Parkin Max , Ajiki Wakiko , Tsukuma Hideaki
Published: August 2002

The mortality and incidence from stomach cancer were compared in Japan (a country with a high incidence where there was full application of mass screening during this period) and 2 countries with no screening policy: the USA (with a very low incidence) and Slovenia (with an intermediate rate). The registered cases of stomach cancer were from the Osaka Cancer Registry, the Slovenian National Cancer Registry and the Surveillance, Epidemiology, and End Results (SEER) registries in the USA. In the period 1975–95, the age‐adjusted incidence rate (/100,000) of stomach cancer declined in the 3 countries, as follows: Japan, from 76.0 to 53.0 in men and 38.4 to 21.3 in women; Slovenia, from 40.2 to 24.1 in men and 16.6 to 10.8 in women; and the USA, from 9.5 to 6.9 in men and 4.3 to 2.9 in women. During the same period, the age‐adjusted mortality rate declined, as follows: Japan, from 60.2 to 34.2 in men and 30.5 to 14.1 in women; Slovenia, from 37.7 to 21.2 in men and 13.8 to 9.0 in women; the USA, from 5.6 to 4.7 in men and 2.5 to 2.3 in women. In the period studied, specific trends on incidence and mortality with a cohort effect occurred only in Japan: analysis by the age period‐cohort model confirmed that the decline has occurred since the generations born in 1910. The trend therefore corresponds to unplanned prevention through changes in environmental factors occurring since the early 20th century. The study of stage‐specific incidence rates confirmed the declining trend for regional cancer, whereas there was an increase in the incidence of localized cancer, associated with a period effect in 1975–95. This is attributed to the policy of early detection of stomach cancer, with the inclusion of intramucosal lesions of favorable prognosis and explains why mortality decreased faster than incidence during the period. © 2001 Wiley‐Liss, Inc.
Risk of gastric cancer among smokers infected with Helicobacter pylori
Authors: Brenner Hermann , Arndt Voler , Bode Günter , Stegmaier Christa , Ziegler Hartwig , Stümer Til
Published: August 2002

Infection with the gastric bacterium Helicobacter pylori (in particular infection with CagA‐positive strains) and smoking have been identified as risk factors for the development of gastric cancer. Both risk factors are typically acquired early in life and prevail over decades if not for life. We assessed the individual and joint impact of both risk factors on gastric cancer risk in a population‐based case‐control study from Germany including 71 patients with histologically verified gastric cancer and 363 patients with colorectal cancer who served as controls. Information on smoking and potential confounding factors was collected by standardized interviews. H. pylori infection was measured serologically by immunoglobulin G antibody titers against H. pylori. In addition, antibodies against the CagA antigen were determined by Western blot. Twenty‐seven percent of cases compared with 15% of controls were smokers, and 43% of cases compared with 23% of controls were infected with CagA‐positive H. pylori strains. After control for potential confounders, the relative risk of gastric cancer was 2.6 (95% CI 1.2‐5.7) for nonsmoking subjects with CagA‐positive H. pylori infections and 7.2 (95% CI 2.2–23.6) for smoking subjects with CagA‐positive H. pylori infections compared with subjects without these risk factors. The corresponding relative risks for noncardia gastric cancer were 6.1 ( 95% CI 2.3–16.5) and 16.6 (95% CI 4.3–64.2). We conclude that smoking subjects with CagA‐positive H. pylori infections have a strongly increased risk of gastric cancer and may be an important group for targeting efforts of prevention and early detection. © 2002 Wiley‐Liss, Inc.
Reduced poly(ADP‐ribosyl)ation in lymphocytes of laryngeal cancer patients: Results of a case‐control study
Authors: Rajaee‐Behbahani Nahid , Schmezer Peter , Ramroth Heribert , Bürkle Alexander , Bartsch Helmut , Dietz Andreas , Becher Heiko
Published: August 2002

Poly(ADP‐ribose) polymerase (PARP), a nuclear enzyme that is catalytically activated by DNA strand breaks, plays a complex role in DNA repair. Using NAD+ as a precursor, it catalyzes the formation of ADP‐ribose polymers, which are attached to various proteins. Defects in DNA repair pathways have been associated with increased risks for cancer in humans. We investigated whether differences in the activity of PARP are associated with the risk for laryngeal cancer. In a case‐control study on genetic, lifestyle and occupational risk factors for laryngeal cancer, PARP activity was assessed as DNA damage–induced poly(ADP‐ribose) formation in human peripheral blood lymphocytes by quantitative immunofluorescence analysis. Polymer formation was determined as the cellular response to bleomycin, a well‐known inducer of DNA strand breaks, in lymphocytes from 69 laryngeal cancer patients and 125 healthy controls. The frequency of bleomycin‐induced polymer formation, measured as mean pixel intensity, was significantly lower in cases (74.6, SE = 3.7) than in controls (94.5, SE = 3.5) and not influenced by smoking, age or sex. There was no significant difference between cases (59.1, SE = 5.2) and controls (50.5, SE = 3.7) in basal polymer formation (in cells not treated with bleomycin). When the highest tertile of polymer formation was used as the reference, the odds ratio for the lowest tertile of bleomycin‐induced polymer formation was 3.79 (95% confidence interval 1.37–10.47, p = 0.01). Peripheral blood lymphocytes from laryngeal cancer patients thus showed significantly less bleomycin‐induced poly(ADP‐ribose) formation. Our results suggest that a reduced capacity of somatic cells to synthesize poly(ADP‐ribose) might be associated with an increased risk for laryngeal cancer. The underlying mechanism remains to be investigated. © 2002 Wiley‐Liss, Inc.
Identification and prevalence of CD8+ T‐cell responses directed against Epstein‐Barr virus‐encoded latent membrane protein 1 and latent membrane protein 2
Authors: Meij Pauline , Leen Ann , Rickinson Alan B. , Verkoeijen Saertje , Vervoort Marcel B.H.J. , Bloemena Elisabeth , Middeldorp Jaap M.
Published: August 2002

Epstein‐Barr virus (EBV) is associated with several human malignancies that each show different viral gene expression profiles. In malignancies such as Hodgkin's disease and nasopharyngeal carcinoma only Epstein‐Barr nuclear antigen 1 (EBNA1) and varying levels of latent membrane proteins 1 and 2 (LMP1 and ‐2) are expressed. Since endogenously expressed EBNA1 is protected from CTL recognition, LMP1 and LMP2 are the most likely target antigens for anti‐tumor immunotherapy. Therefore, we sought to identify in a systematic way CD8+ T‐cell responses directed against eptitopes derived from LMP1 and LMP2. Using IFNγ‐ELISPOT assays of interferon‐γ release, peripheral blood mononuclear cells (PBMC) of healthy donors were screened with peptide panels (15 mer overlapping by 10) spanning the LMP1 and LMP2 sequences of the prototype EBV strain B95.8. When positive responses were found, CD4+ or CD8+ T cells were depleted from donor PBMC to determine the origin of the responder population. We detected CD8+ T‐cell responses to LMP1 in 9/50(18%) donors and to LMP2 in 15/28 (54%) donors. In addition to the already described epitopes, 3 new LMP1‐ and 5 new LMP2‐derived CD8+ epitopes were identified. In most donors LMP1‐ and LMP2‐specific CD8+ precursor frequencies were low compared with precursors against immunodominant EBV epitopes from latent (EBNA3A, ‐3B and ‐3C) and lytic cycle antigens. These results demonstrate that CD8+ memory T cell responses to LMP1 and especially to LMP2 do exist in Caucasians, albeit at low levels and could potentially be exploited for therapeutic use. © 2002 Wiley‐Liss, Inc.
Promiscuous expression of Epstein‐Barr virus genes in Burkitt's lymphoma from the central African country Malawi
Authors: Xue Shao‐an , Labrecque Louise G. , Lu Qi‐Long , Ong S. Kate , Lampert Irvin A. , Kazembe Peter , Molyneux Elizabeth , Broadhead Robin L. , Borgstein Eric , Griffin Beverly E.
Published: August 2002

Primary BL in Malawian children has a very high frequency association, approaching 100%, with the human herpesvirus EBV. A detailed study carried out on viral gene expression in these tumours, using both fresh material and methanol‐fixed FNAs, showed, contrary to prediction, that most belong to a variant “class II” latency category, with lytic cycle–related genes also expressed. That is, in addition to EBNA1 expression, membrane proteins (LMP1/2A), immediate early (BZLF1) and early (IR2 and IR4) genes, a putative viral oncogene (BARF1), CST (BART) antisense transcripts and the viral bcl‐2 homologue are expressed in a high proportion of the BLs. Most, but not all, express the small viral (EBER) RNAs. Two other significant observations were made: (i) in addition to expression of cellular cytokine (IL‐10) transcripts in all tumours investigated, the normally silent viral IL‐10 homologue was expressed in some tumours; (ii) whereas EBNA1 expression from its restricted Qp promoter was generally observed, the nonrestricted Cp/Wp promoter was also active in some tumours. Viral gene expression in the Malawian [endemic (e)] BLs appears to be more promiscuous than predicted from other studies, but expression accords with the cytopathologic picture of eBLs as a rapidly proliferating cell population accompanied by considerable necrosis, and a clinically diverse disease. A small‐scale study of relapse Malawian BLs revealed a different picture of viral association, more akin to systemic BL than eBL, where EBV appears to be absent or present only at very low levels. The significance of these findings is considered. © 2002 Wiley‐Liss, Inc.
Cancer modifier alleles inhibiting lung tumorigenesis are common in inbred mouse strains
Authors: Manenti Giacomo , Acevedo Abraham , Galbiati Federica , Giannfi Barrera Roberto , Noci Sara , Salido Eduardo , Dragani Tommaso A.
Published: August 2002

Lung tumor susceptibility in inbred mouse strains is caused by the susceptibility allele at the pulmonary adenoma susceptibility 1 (Pas1s) locus. However, after urethane treatment, most strains carrying the Pas1s allele show an intermediate (1–4 tumors/mouse) instead of a highly susceptible (15–30 tumors/mouse) lung tumor phenotype. To test the hypothesis that strains displaying the intermediate lung tumor phenotype carry dominant or codominant resistance alleles at pulmonary adenoma resistance (Par) loci, we crossed mice of intermediate susceptibility or resistance to lung tumorigenesis with the highly susceptible A/J strain. Eleven F1 hybrids were treated with urethane to induce lung tumorigenesis. The A/J strain developed 35.3 tumors/mouse, while its F1 hybrid with C57BL/6J mice (null allele at Par loci) developed 22.8 tumors/mouse due to the Pas1 allele dosage effect. F1 hybrids of strains 129/SvJ, CBA/J, ST/J and LP/J (Pas1s) and of SPW, DBA/2J and C57L/J (Pas1r) mice showed significant reduction in lung tumor multiplicity (i.e., 0.3–12.8 tumors/mouse) compared to A/J and (A/J × C57BL/6J)F1 mice. These results indicate that resistance alleles at Par loci are common in inbred mouse strains and account for the lung tumorigenesis intermediate phenotype of strains carrying the Pas1s allele. © 2002 Wiley‐Liss, Inc.
Biodistribution of hypericin in orthotopic transitional cell carcinoma bladder tumors: Implication for whole bladder wall photodynamic therapy
Authors: Kamuhabwa Appolinary A.R. , Cosserat‐Gerardin Isabelle , Didelon Jacques , Notter Dominique , Guillemin François , Roskams Tania , D'Hallewin Marie‐Ange , Baert Luc , de Witte Peter A.M.
Published: August 2002

In a recent clinical study, we reported a selective uptake of hypericin in superficial bladder tumors. The results suggested that hypericin, a potent photosensitizer, could be used not only for diagnosis but also for photodynamic therapy (PDT) of superficial bladder tumors. In the present study, we investigated the biodistribution of hypericin in an orthotopic rat bladder tumor model by assessing the extent of hypericin penetration and the kinetics of accumulation into rat bladder tumors and normal bladder wall. Hypericin (8 or 30 μM) was instilled into the bladder via the catheter for 1, 2 or 4 hr. The fluorescence of hypericin in the bladder tumors and normal bladder was documented using fluorescence microscopy. In situ quantification of hypericin fluorescence in the tumor or normal bladder was performed using the laser‐induced fluorescence technique. There was much more hypericin fluorescence in the tumor than in the normal bladder, with the tumor‐to‐normal‐bladder ratio mounting to 12:1 after 4 hr of hypericin (30 μM) instillation. Moreover, hypericin was retained in the tumor for at least 1 hr before it was gradually lost from the tissue. Microscopically, the fluorescence of hypericin was restricted to the urothelial tumor and normal urothelium without fluorescence in the submucosa and the muscle layers. Subsequently no hypericin was detected in plasma, indicating that under these conditions systemic side effects should not be expected. Because the conditions used in this study were similar to those used in our previous clinical study, it is therefore likely that whole bladder wall PDT in the clinic under these conditions will produce selective urothelial tumor destruction without causing damage to the underlying muscle layers. © 2002 Wiley‐Liss, Inc.
P53 overexpression predicts poor chemosensitivity to high‐dose 5‐fluorouracil plus leucovorin chemotherapy for stage IV colorectal cancers after palliative bowel resection
Authors: Liang Jin‐Tung , Huang Kuo‐Chin , Cheng Yung‐Ming , Hsu Hey‐Chi , Cheng Ann‐Lii , Hsu Chih‐Hung , Yeh Kun‐Huei , Wang Shih‐Ming , Chang King‐Jen
Published: August 2002

Our study aims to further clarify the prognostic significance of p53 overexpression in stage IV colorectal cancer. Between January 1994 and June 1997, we recruited 144 patients with stage IV colorectal cancers for our study, based on appropriate eligibility criteria. The patients were nonrandomly allocated to 2 treatment groups of either with or without high‐dose 5‐fluorouracil plus leucovorin chemotherapy (HDFL: 5‐Fu: 2,600 mg/m2 leucovorin 300 mg/m maximum 500 mg). Each treatment group was further divided into 2 subgroups according to the status of p53 overexpression. Therefore, 4 subgroups were allocated in our study and were designated as p53 (overexpression) HDFL (+), n = 65; p53 (normal) HDFL (+), n = 37; p53 (overexpression) HDFL (−), n = 27; and p53 (normal) HDFL (−), n = 15, respectively. All patients were prospectively followed until April 2001. There was no significant difference of the background clinicopathologic data of these 4 allocated subgroups of patients (p > 0.05). Multivariate analysis of various clinicopathologic factors of the whole group of patients indicated that age ≥60 years, poor differentiation, mucin production, CEA >100 ng/ml, p53 overexpression and without chemotherapy were the significant independent poor prognostic factors (p < 0.05). Survival analyses indicated that the patients of subgroup p53 (normal) HDFL (+) survived significantly longer than those of subgroup p53 (overexpression) HDFL (+), with mean survival time (95% confidence interval [CI]) of 20.24 (16.24–24.25) and 13.29 (10.98–15.60) months, respectively (p = 0.0043, log‐rank test). In contrast, in patients without chemotherapy, the prognosis was poor regardless of their p53 status, with mean survival time (95% CI) of 6.85 (5.47–8.23) and 5.87 (4.48–7.26) months in p53 (overexpression) HDFL (−) and p53 (normal) HDFL (−) subgroups of patients, respectively (p = 0.2820, log‐rank test). Cancers of normal p53 expression responded significantly better to HDFL (p < 0.05), with mean response rate (95% CI) being 65.57% (52.18–82.96%) in subgroup p53 (normal) HDFL (+) as compared to 35.38% (23.52–47.24%) in subgroup p53 (overexpression) HDFL (+). The toxicity to HDFL was similarly minimal between p53‐normal and p53‐overexpression patients (p > 0.05). We thus concluded that the poorer prognosis of stage IV colorectal cancers with p53 overexpression was associated with their poorer chemosensitivity rather than the more biologic aggressiveness. © 2001 Wiley‐Liss, Inc.
A partial theory of world development: the neglected role of the demographic transition in the shaping of modern society
Authors: Dyson Tim
Published: August 2002

This paper argues that the demographic transition has been central to the creation of the modern world, and that its role in this respect has generally been underestimated. The paper proposes a partial, causal theory – operating at the ‘super‐macro’ level, and over the very long run – for several major aspects of world ‘development’. Key elements of the argument are that sustained mortality decline causes both urbanisation and fertility decline. In turn, urbanisation leads inevitably to an increased division of labour and the wider distribution of political power in society. Fertility and mortality decline contribute to reduced gender differentiation and women become more like men. Population ageing probably contributes to the rise of modern democracy. Unless development theory puts the demographic transition at its core, it cannot adequately account for key social–structural transformations which are integral to the concept of development. Copyright © 2001 John Wiley & Sons, Ltd.
Maternities in ‘out‐of‐the‐way’ places: epistemological possibilities for retheorising population geography
Authors: Underhill‐Sem Yvonne
Published: August 2002

This paper argues that theories of embodiment have particular epistemological importance in the way population geography analyses fertility. This is because such theories remind us that knowledge is produced by sexually embodied subjects in particular places and times. The paper discusses the epistemological importance of interrogating the unproblematic view of embodiment, and of motherhood as a natural given in population geography. It reviews how the body as a natural given has been interrogated within geography as a discipline, then focuses on the specific contributions of two critical feminist social theorists. This radically expands the otherwise narrow view that fertility patterns in different places and times are currently known. Although in its early stages of articulation, rethinking fertility in this way dovetails with recent work in other subdisciplines in geography such as the debates over the question of nature. In this way population geographers can make critical contributions to wider debates in geography and the social sciences in general. Copyright © 2001 John Wiley & Sons, Ltd.
Fathering relationships and their associations with juvenile delinquency
Authors: Shears Jeffrey , Robinson JoAnn , Emde Robert N.
Published: August 2002

This study explores the intergenerational transmission of fathering by addressing the associations between men's relationship with their father, their attachment to their children, self‐assessment of themselves as fathers, and antisocial behavior. Subjects for this study were 87 men who were identified as fathers or father figures by women involved in two Early Head Start sites in Denver, Colorado. They were interviewed about their experiences when their child was between 2 and 3 years of age. The study found men who reported high antisocial behavior during their youth reported low assessment of themselves as fathers whereas men who reported a positive relationship with their fathers reported high assessments of themselves as fathers. ©2002 Michigan Association for Infant Mental Health.
Temperamental characteristics as predictors of externalizing and internalizing child behavior problems in the contexts of high and low parental psychopathology
Authors: Young Mun Eun , Fitzgerald Hiram E. , Von Eye Alexander , Puttler Leon I. , Zucker Robert A.
Published: August 2002

This study investigated whether the relationships between dimensions of early child temperament and externalizing and internalizing behavior problems differ in relation to the degree of parental psychopathology to which children are exposed. In addition, the reciprocal relation between externalizing and internalizing behavior problems, and stability patterns (i.e., autoregression) of externalizing and internalizing behavior problems were investigated using a two‐group structural model. A sample of 215 boys (mean age = 4.22) and their parents were assessed when the boys were 3–5 years old and again when they were 6–8 years old. For the children of parents with two or more lifetime psychopathology diagnoses, high activity, short attention span/distractibility, and high reactivity were linked to externalizing behavior problems, whereas withdrawal was linked to internalizing behavior problems. For children from low parental psychopathology families, only reactivity was linked to externalizing behavior problems, whereas withdrawal was linked to internalizing behavior problems. Children from high parental psychopathology families (alcohol use disorder and antisocial personality disorder) showed lower stability (autoregression) estimates of behavior problems. The reciprocal relation between externalizing and internalizing behavior problems was supported when children were 6–8 years old, but not when they were 3–5 years old. © 2001 Michigan Association for Infant Mental Health.
Monetary policy analysis and inflation targeting in a small open economy: a VAR approach*
Authors: Jacobson Tor , Jansson Per , Vredin Anders , Warne Anders
Published: August 2002

Empirical monetary policy research has increased in the last decade, possibly because deregulation and explicit monetary targets have made monetary policy issues more interesting. In particular, within the inflation targeting framework it has been argued that inflation forecasts can be used as optimal intermediate targets for monetary policy, and the development of empirical models that have good forecasting properties is therefore important. This paper shows that a VAR model with long‐run restrictions, justified by economic theory, is useful for both forecasting inflation and for analysing other issues that are central to the conduct of monetary policy. Copyright © 2001 John Wiley & Sons, Ltd.
Unemployment insurance and subsequent job duration: job matching versus unobserved heterogeneity
Authors: Belzil Christian
Published: August 2002

The relationship between Unemployment Insurance (UI) benefit duration, unemployment duration and subsequent job duration is investigated using a multi‐state duration model with state specific unobserved heterogeneity. I examine two potential explanations for the negative correlation between unemployment and job spell durations; UI benefits increase job matching quality (the ‘Matching’ effect) versus unobserved heterogeneity (‘Adverse Selection’). The Matching effect is found to be weak. Although new jobs accepted within 5 weeks of benefit termination seem to have a higher dissolution rate, the negative correlation between unemployment and job duration is mostly explained by unobserved heterogeneity. Various simulations indicate that increasing the maximum benefit duration by one week will raise expected unemployment duration by 1.0 to 1.5 days but will raise expected job duration by 0.5 to 0.8 day only. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of the oestrogenic (uterotrophic) activity of extracts of ‘general purpose polystyrene (GPPS)’ using immature female rats
Authors: Prinsen Menk K. , Gouko Nobuaki
Published: August 2002

In Japan there is growing concern about the possible adverse effects of consumption of food from styrene containers (mainly those made from polystyrene paper) due to the alleged oestrogenic activity of styrene oligomers (dimers and trimers), which may migrate into the food. To examine the possible oestrogenic activity of styrene dimers and trimers, extracts were made from ‘general purpose polystyrene (GPPS)’ and administered orally to immature female rats over a 4 day period. Increase of uterus weight (wet and blotted) was used for assessment of possible oestrogenic activity. To establish the sensitivity of the test method, immature rats were treated with diethylstilboestrol (DES), a well‐known oestrogenic compound.

It was found that treatment of rats with levels of up to 60 μg of styrene dimers and 930 μg of styrene trimers per kilogram body weight per day did not give any statistically significant increase of the uterus weight (wet or blotted), whereas DES caused statistically significant, dose‐related increases in uterus weight at levels as low as 0.89 μg kg−1 body weight day−1. It was concluded that, compared with the estimated maximum human daily intake of styrene trimers of 1 μg kg−1 body weight day−1 from polystyrene food containers, the risk of adverse human health effects with respect to oestrogenicity may be considered negligible. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of lead and zinc on rat male reproduction at ‘biochemical and histopathological levels’
Authors: Batra N. , Nehru B. , Bansal M. P.
Published: August 2002

Sequential lead accumulation and biochemical and histopathological changes were observed in rat testis and epididymis after oral administration at varied doses of lead (10, 50 and 200 mg kg−1 body wt.) for 3 months and also following the concomitant administration of lead with zinc (1 mg kg−1 body wt. +50 mg Pb kg−1 body wt.). Accumulation of lead in both testis and epididymis increased with dose. The concomitant administration of zinc reduced the lead levels. Similarly, dose‐related changes were seen in the activities of the enzymes alkaline phosphatase and Na+–K+‐ATPase, which decreased with increased dose of lead. A significant improvement in the activities of these enzymes was seen in the groups given both lead and zinc. Histologically, discernible changes were noticed only at higher doses (50 and 200 mg kg−1 body wt.), which included disorganization and disruption of spermatogenesis with accumulation of immature cells in lumen of tubule. At higher doses of lead, complete arrest of spermatogenesis was seen and a significant decrease in germ cell layer population was evident. Even in epididymis, the histoarchitecture was disrupted only at higher doses of lead both in the caput and corpus regions. The changes included damage of basement membrane, disorganization of epithelium and vacuolization of cells. The tubules were found almost empty, indicating arrest of spermatogenesis. However, with concomitant administration of lead and zinc both testis and epididymis presented a near‐normal picture, indicating the protective role of zinc. Hence, the data indicate that the protective effect of zinc on lead toxicity was mediated largely by significant competition between lead and zinc or due to reduction of the available binding sites. Copyright © 2001 John Wiley & Sons, Ltd.
In vivo evaluation of a dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to implantable medical devices
Authors: Hickey T. , Kreutzer D. , Burgess D. J. , Moussy F.
Published: August 2002

The purpose of this research effort was to evaluate in vivo a newly developed dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to an implanted device, in this case a biosensor. The microspheres were prepared using an oil/water (O/W) emulsion technique. The microsphere system was composed of drug‐loaded microspheres (including newly formulated and predegraded microspheres) and free dexamethasone. The combination of the drug and drug‐loaded microspheres provided burst release of dexamethasone followed by continuous release from days 2–14. Continuous release to at least 30 days was achieved by mixing predegraded and newly formulated microspheres. The ability of our mixed microsphere system to control tissue reactions to an implant then was tested in vivo using cotton thread sutures to induce inflammation subcutaneously in Sprague−Dawley rats. Two different in vivo studies were performed, the first to find the dosage level of dexamethasone that effectively would suppress the acute inflammatory reaction and the second to show how effective the dexamethasone delivered by PLGA microspheres was in suppressing chronic inflammatory response to an implant. The first in vivo study showed that 0.1 to 0.8 mg of dexamethasone at the site minimized the acute inflammatory reaction. The second in vivo study showed that our mixed microsphere system suppressed the inflammatory response to an implanted suture for at least 1 month. This study has proven the viability of microsphere delivery of an anti‐inflammatory to control the inflammatory reaction at an implant site. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 180–187, 2002
Comparitive study of the formation of hydroxyapatite in simulated body fluid under static and flowing systems
Authors: Siriphannon Punnama , Kameshima Yoshikazu , Yasumori Atsuo , Okada Kiyoshi , Hayashi Shigeo
Published: August 2002

α‐CaSiO3 ceramics of nominal composition CaO 46.0, SiO2 54.0, and Na2O 0.4 mass% were soaked in simulated body fluid (SBF). The soaking systems were maintained under both static and flowing conditions to study their effect on the formation of hydroxyapatite (HAp). Two different flowing systems were designed for soaking, namely, a closed system using a fast flow rate of about 2.8 mL/s (circulating system) and an open system using a slow flow rate of about 40 mL/day (slow flowing system). The HAp layer in all samples initially formed as a rough layer of ball‐like particles. Under a fast flow of SBF solution, silica gel particles peeled from silica‐rich interlayer during the first soaking period. The silica gel particles then reattached to the product HAp layer and induced the formation of new HAp particles of smaller size. In the slow flowing system, the rough HAp layer initially formed on the ceramic surfaces became gradually smoother after prolonged soaking. The formation rate and thickness of the HAp layer decreased with increasing flow rate of the SBF solution. These results indicate that flowing SBF solution gives rise to differences in the formation rates, formation behavior, and microstructure of the HAp layer. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 175–185, 2002
Biomechanical comparison of the sandblasted and acid‐etched and the machined and acid‐etched titanium surface for dental implants
Authors: Li Dehua , Ferguson Stephen J. , Beutler Thomas , Cochran David L. , Sittig Caroline , Hirt Hans Peter , Buser Daniel
Published: August 2002

To make a direct biomechanical comparison between the sandblasted and acid‐etched surface (SLA) and the machined and acid‐etched surface (MA), a well‐established animal model for implant removal torque testing was employed, using a split‐mouth experimental design. All implants had an identical cylindrical solid‐screw shape with the standard ITI thread configuration, without any macroscopic retentive structures. After 4, 8, and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each surface type. Results showed that the SLA surface was more powerful in enhancing the interfacial shear strength of implants in comparison with the MA surface. Removal torque values of the SLA‐surfaced implants were about 30% higher than those of the MA‐surfaced implants (p = 0.002) except at 4 weeks, when the difference was at the threshold of statistical significance (p = 0.0519). The mean removal torque values for the SLA implants were 1.5074 Nm at 4 weeks, 1.8022 Nm at 8 weeks, and 1.7130 Nm at 12 weeks; and correspondingly, 1.1924 Nm, 1.3092 Nm, and 1.3226 Nm for the MA implants. It can be concluded that the SLA surface achieves a better bone anchorage than the MA surface, and that sandblasting before acid etching has a beneficial effect on the interfacial shear strength. As regards the bone–implant interfacial stiffness calculated from the torque‐rotation curve, the SLA implants showed an overall more than 5% higher stiffness compared with the MA implants, although the difference did not reach the statistical significance level. © 2002 John Wiley & Sons, Inc. J Biomed Mater Res 60: 325–332, 2002; DOI 10.1002/jbm.10063
Prophylactic treatment of gram‐positive and gram‐negative abdominal implant infections using locally delivered polyclonal antibodies
Authors: Poelstra Kornelis A. , Barekzi Nazir A. , Rediske Andrea M. , Felts Adrian G. , Slunt Jeffrey B. , Grainger David W.
Published: August 2002

The increasing clinical incidence and host risk of biomaterial‐centered infections, as well as the reduced effectiveness of clinically relevant antibiotics to treat such infections, provide compelling reasons to develop new approaches for treating implanted biomaterials in a surgical context. We describe the direct local delivery of polyclonal human antibodies to abdominal surgical implant sites to reduce infection severity and mortality in a lethal murine model of surgical implant‐centered peritoneal infection. Surgical implant‐centered peritonitis was produced in 180 female CF‐1 mice by the direct inoculation of surgical‐grade polypropylene mesh disks placed in the peritoneal cavity with lethal doses of either methicillin‐resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. Mice randomly received a resorbable antibody delivery vehicle at the implant site: either a blank carboxymethylcellulose (CMC) aqueous gel or the same CMC gel containing 10 mg of pooled polyclonal human immunoglobulin G locally on the implant after infection, either alone or in combination with systemic doses of cefazolin or vancomycin antibiotics. Human antibodies were rapidly released (first‐order kinetics) from the gel carrier to both peritoneal fluids and serum in both infection scenarios. Inocula required for lethal infection were substantially reduced by surgery and the presence of the implant versus a closed lethal peritonitis model. Survival to 10 days with two different gram‐negative P. aeruginosa strains was significantly enhanced (p < 0.01) by the direct application of CMC gel containing antibodies alone to the surgical implant site. Human‐equivalent doses of systemic vancomycin provided a significantly improved benefit (p < 0.01) against lethal, implant‐centered, gram‐positive MRSA infection. However, locally delivered polyclonal human antibodies in combination with a range of systemic vancomycin doses against MRSA failed to improve host survival. Successful antibody therapy against gram‐negative, implant‐centered infections complements the clinically routine use of systemic antibiotics, providing a mechanism of protection independent of antibiotic resistance. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 206–215, 2002
Biodegradable polyurethanes for implants. II. In vitro degradation and calcification of materials from poly(ϵ‐caprolactone)–poly(ethylene oxide) diols and various chain extenders
Authors: Gorna Katarzyna , Gogolewski Sylwester
Published: August 2002

Linear, biodegradable, aliphatic polyurethanes with various degrees of hydrophilicity were synthesized in bulk at 50–100°C. The ratios between the hydrophilic and hydrophobic segments were 0:100, 30:70, 40:60, 50:50, and 70:30, respectively. The hydrophilic segment consisted of poly(ethylene oxide) (PEO) diol (molecular weight = 600 or 2000) or the poly(ethylene–propylene–ethylene oxide) (PEO–PPO–PEO) diol Pluronic F‐68 (molecular weight = 8000). The hydrophobic segment was made of poly(ϵ‐caprolactone) diol (molecular weight = 530, 1250, or 2000). The chain extenders were 1,4‐butane diol and 2‐amino‐1‐butanol. The diisocyanate was aliphatic hexamethylene diisocyanate. The polymers absorbed water in an amount that increased with the increasing content of the PEO segment in the polymer chain. The total amount of absorbed water did not exceed 2% for the poly(ester urethane)s and was as high as 212% for some poly(ester ether urethane)s that behaved in water like hydrogels. The polymers were subjected to in vitro degradation at 37 ± 0.1°C in phosphate buffer solutions for up to 76 weeks. The poly(ester urethane)s showed 1–2% mass loss at 48 weeks and 1.1–3.8% mass loss at 76 weeks. The poly(ester ether urethane)s manifested 1.6–76% mass loss at 48 weeks and 1.6–96% mass loss at 76 weeks. The increasing content and molecular weight of the PEO segment enhanced the rate of mass loss. Similar relations were also observed for polyurethanes from PEO–PPO–PEO (Pluronic) diols. Materials obtained with 2‐amino‐1‐butanol as the chain extender degraded at a slower rate than similar materials synthesized with 1,4‐butane diol. All the materials already manifested a progressive decrease in the molecular weight in the first month of in vitro aging. The rate of molecular weight loss was higher for poly(ester ether urethane)s than for poly(ester urethane)s. For poly(ester ether urethane)s, the rate of molecular weight loss was higher for materials containing Pluronic than for those containing PEO segments. All polymers calcified in vitro. The susceptibility to calcification increased with material hydrophilicity. The progressive deposition of calcium salt on the film surfaces resulted in the formation of large crystal aggregates, the structure of which depended on the chemical composition of the calcified material. Needlelike aggregates, resembling brushite, formed on the hydrophobic polyurethane, and platelike crystals formed on the highly hydrophilic material. The calcium‐to‐phosphorus atomic ratio of the crystals growing on the samples was dependent on the chemical composition of the material and varied from 0.94 to 1.55. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 592–606, 2002
Concentration‐ and composition‐dependent effects of metal ions on human MG‐63 osteoblasts
Authors: Hallab Nadim James , Vermes Csaba , Messina Carlo , Roebuck Kenneth A. , Glant Tibor T. , Jacobs Joshua J.
Published: August 2002

Metal debris from implants has been shown to alter the function of osteoblasts in cell cultures. Its remains unclear, however, if specific forms of released ionic metals are involved in the pathogenesis of periprosthetic osteolysis. We evaluated the relative effects of ionic forms of implant metals by treating human osteoblast‐like MG‐63 osteosarcoma cells with eight concentrations (0.001–10.0 mM) of Cr+3, Mo+5, Al+3, Ta+5, Co+2, Ni+2, Fe+3, Cu+2, Mn+2, Mg+2, Na+2, and V+3 chloride solutions. The results demonstrated that the metal ions differentially affected osteoblast proliferation, viability, type‐I collagen gene expression, and cytokine release. The metal ions were ranked in order from least to most toxic (based on a 50% reduction in viability) as follows: Na < Cr < Mg < Mo < Al < Ta < Co < Ni < Fe < Cu < Mn < V. Metal‐induced decreases in osteoblast proliferation were similar in ranking. Nontoxic concentrations of metals had no effect on procollagen α1[I] gene expression; only at toxic concentrations did metals produce a decrease in gene expression. The most toxic metals (V, Mn, Fe, and Ni) were also the only metals found to induce IL‐6 secretion on a per cell basis (of the cytokines tested, interleukin 6 (IL‐6), interleukin beta 1 (IL‐1β), transforming growth factor beta 1 (TGF‐β1), and tumor necrosis factor alpha (TNF‐α), only IL‐6 was detectable in the culture medium after 48 h for any metal at any concentration). Less toxic metals (e.g., Co and Cr) had little effect on IL‐6 release, even at high concentrations. In general, metal ions reduced osteoblast function (i.e., proliferation and collagen gene expression) in proportion to the degree of toxicity. These results support the hypothesis that adverse local cellular responses (particularly necrotic responses) associated with metal debris from implanted metallic devices may be due in part to metal ions released from implants or from particulate debris. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 420–433, 2002; DOI 10.1002/jbm.10106
A comparison of the shapes of hydroxyapatite implants before and after implantation
Authors: Abe Keita , Ono Ichiro
Published: August 2002

Based on helical volume scan computed tomography (HVCT) data, it has been demonstrated previously that real‐size models can be prepared with the binder‐jet method with extremely high precision of various parts ranging from the outer structure of the cranio‐maxillofacial bone to such fine parts as the cranial base and the orbital walls. The application of this method to clinical cases with large cranial bone defects has also been studied. The results showed the usefulness of the binder‐jet method, employing starch for fixing, with which a model can be prepared faster and with less deformity caused by the weight of the material itself. Therefore, the binder‐jet method is expected to attain greater clinical significance in this field.In this study the comparison between the shapes of implants before and after implantation revealed that the most important aspect of the design of hydroxyapatite (HAP) implants was determining the shapes of edges, especially its angles. That is, an implant needs very little trimming before being implanted to the patient's defective site if the shape of the edges of the implant can be designed and prepared to fix the incised bone surfaces properly. In addition, to obtain optimum results it was also shown that it is necessary to design optimal shapes of implants, taking into account thickness, porosity, and curvature, before processing the shapes of edges. It was found necessary to establish a technology and a method for producing HAP implants that perfectly fit cranial bone defects. For this purpose, it would be useful to make a template of the implants using the mirror‐reversion and binder‐jet methods. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 312–318, 2002