bluuebunny/crossref_metadata_2025 huggingface dataset:
Do scent marks increase predation risk of microtine rodents?
Authors: Koivula Minna , Korpimäki Erkki
Published: December 2004

Reproductive activities, including signalling with scents, may increase the risk of predation. Mammalian predators, like small mustelids, find voles by using odour cues of scent marks. Scent marks are also visible in ultraviolet light, and at least some diurnal raptors are attracted to these markings in the field. We performed a field experiment to find out whether manipulation of scent markings affects the density, survival and mobility of free‐living voles, and the activity of mammalian and avian predators. A total of 20 plots (each 1 ha) were randomly divided into two treatments: scent manipulation and control plots. Scent manipulation plots were treated with vole scent‐liquid and control plots with water. From each plot 1–2 voles were radio‐collared and tracked for three weeks. Predators hunted more often on scent manipulation plots than on control plots leading to lower survival time of voles. Although scent manipulation attracted more avian predators, small mustelids were the main predators of voles. The density or the mobility of voles did not differ significantly between manipulation and control plots. Our results suggest that odour of scent marks may be a larger risk to voles than UV visibility of scent marks.
Species pools and the “hump‐back” model of plant species diversity: an empirical analysis at a relevant spatial scale
Authors: Safford Hugh DeForest , Rejmánek Marcel , Hadač Emil
Published: December 2004

We investigated the relative roles of productivity, the species pool, and spatial habitat structure in determining local species richness (alpha diversity) of plant communities within a single, well‐defined landscape unit, at spatial and ecological scales where the relationship between community productivity and species diversity often assumes a unimodal or “hump‐back” form. At high levels of productivity, the decrease‐phase of the unimodal model of the diversity‐productivity relationship is typically explained as the dynamic outcome of increased competitive exclusion, but it may also be the passive consequence of a small pool of species possessing attributes necessary to competitively survive in high‐fertility environments. We conducted statistical analyses of previously collected data to determine whether variations in local richness in the herbaceous vegetation of a Slovakian mountain valley were best explained by habitat productivity itself (which presumably leads to more intense competition) or by the sizes of the relevant community species pools. We also used measures of spatial habitat structure to investigate the extent to which habitat patchiness influenced patterns of species diversity. In the study system, both community biomass and size of the species pools contributed significantly to local species richness, but the positive effect of the species pools was about twice as important as the negative effect of biomass. The combined area of related associations (alliance area), association perimeter, and habitat patch geometry were all closely related to species pool size.
Effects of population size and isolation on reproductive output in Aquilegia canadensis (Ranunculaceae)
Authors: Mavraganis Katherine , Eckert Christopher G.
Published: December 2004

It is generally expected that small, isolated populations will suffer reduced fitness due to inbreeding, yet few studies have investigated the relation between population characteristics, inbreeding and fitness. Among Ontario populations of the short‐lived, perennial plant Aquilegia canadensis, large populations (N>90 flowering plants) outcross twice as frequently as small populations (N=30–40), and inbreeding depression is extremely strong. We tested the prediction that reproductive output, a major component of population fitness, should be positively associated with population size. Data from a survey of 33 populations located on small islands in the St. Lawrence River, Canada and 23 populations on adjacent mainland areas supported this prediction. Population size correlated positively with reproductive output, measured as the number of seedlings produced per plant in 1995 (average r=+0.39 pooled P=0.019), and the number of fruits per plant in 1997 (r=+0.30, P=0.056). We also tested the prediction that fitness should decline with increasing spatial isolation between populations by measuring the distance separating all island populations. However, reproductive output did not correlate with isolation in either year. We compared island and mainland populations to test the prediction that reproductive output should be lower for populations on small islands than those occurring in more continuous mainland habitat. In contrast to our predictions, island populations exhibited, if anything, higher reproductive output than mainland populations. We also found no support for the prediction that the positive association between population size and reproductive output should be stronger for presumably isolated populations on small islands than for those on adjacent mainland areas. While the mechanisms underlying the association between population size and fitness are impossible to identify with correlations alone, our results are consistent with the hypothesis that inbreeding can significantly reduce the fitness of natural populations.
Interactions between seed predators/pollinators and their host plants: a first step towards mutualism?
Authors: Westerbergh Anna , Westerbergh Johan
Published: December 2004

The mutualisms between fig trees and their pollinator fig wasps and between yucca plants and yucca moths are spectacular examples of coevolution. The characteristics of these independently evolved mutualisms have resulted from long‐term processes, the first stages of which are unknown. A fundamental question in the study of mutualism is how these interactions evolve. Seed predator/pollinator and host plant interactions, which may initially be considered as mainly antagonistic, have the potential to provide good model systems for the study of the first stages of evolution towards mutualism. We present here theoretical models assessing the consequences of interactions between specialized seed predator insects and their host plants. These models describe the parameters that affect the fitness of an individual female seed predator and her influence on the fitness of the host plant. In an optimal strategy for the seed predator, the number of eggs laid in each flower depends on the interaction between the adult and larva survival. Along with a growing predation pressure on adults and larvae several eggs must be laid in each flower by the female seed predator to enhance her fitness. However, in a situation where the host plant selectively aborts flowers with a high number of eggs the fitness of the seed predator will seriously decrease. If the cost of selective abortion is less than the cost of seed predation the host plant will maintain fitness. In a mutualistic relationship a balance between the cost and the benefit of the parameters in the fitness models of the seed predator and the host plant has to occur so that the net seed output is larger than zero (0). Any unselfish behaviour or quality of the seed predator that would benefit the host plant in such a way that the net seed output increases might be a first stage in an interaction becoming mutualistic. The models presented here will not only provide a platform for empirical studies on interactions that may swing from parasitism to mutualism, but also for seed predator/pollinator and host plant interactions in general.
Larval rearing conditions affect kin‐mediated cannibalism in a treehole mosquito
Authors: Dennehy John J. , Robakiewicz Phil , Livdahl Todd
Published: December 2004

Cannibalistic behavior among Ochlerotatus triseriatus larvae was studied to determine whether cannibals are able to alter their attack behavior based on their relatedness to newly hatched conspecific prey larvae. Fourth instar larvae, reared in one of four different initial densities, were placed with newly emerged first instars and, after 48 h, the number of first instar larvae remaining was recorded. Our data suggest a Type III functional response of non‐kin fourth instar larvae to first instar prey density. Several significant effects emerged from our analysis model, namely that the number of first instar prey available, the relationship of the first instar larvae with the cannibals, and the density at which the fourth instar cannibals were reared all affected the number of first instar larvae consumed.
What a wonderful web they weave: spiders, nutrient capture and early ecosystem development in the high Arctic – some counter‐intuitive ideas on community assembly
Authors: Hodkinson Ian D. , Coulson Stephen J. , Harrison Joanna , Webb Nigel R.
Published: December 2004

Spiders are the earliest colonisers of newly exposed moraine substrates on the glacier foreland of the Midtre Lovénbreen at Ny‐Ålesund, W. Spitsbergen, Svalbard (78°N). Spider densities are highly correlated with allochthonous inputs of potential prey items, predominantly chironomid midges. Large allochthonous inputs of insects potentially provide significant quantities of nitrogen and phosphorus to the developing ecosystem from the earliest stages of succession, even before a conspicuous cyanobacterial crust has formed. Spiders entrap nutrients and their possible broader role in early ecosystem development is discussed.
Potentially malignant oral lesions in Northern Ireland: a 20‐year population‐based perspective of malignant transformation
Authors: Cowan CG , Gregg TA , Napier SS , McKenna SM , Kee F
Published: December 2004

This retrospective laboratory‐based study investigates the potential for malignant transformation of oral mucosal lesions in a population of 1.6 million. Over the 20‐year period there were 745 patients diagnosed with primary intra‐oral squamous cell carcinoma (OSCC), 165 patients with dysplasia and 1182 patients with ‘non‐dysplastic’ lesions (epithelial hyperplasia, hyperkeratosis epithelial atrophy, lichen planus and lupus erythematosus). Malignant transformation occurred in 15% of dysplasias and in 1% of ‘non‐dysplastic’ lesions at average intervals after diagnosis of 48 and 65 months respectively. Only 6% of patients with OSCC had a pre‐invasive lesion biopsied. These data suggest that white lesions are only rarely the pre‐invasive phase of OSCC. It is possible therefore that early changes are red, small or even microscopic with carcinoma developing without a clinically observable phase. More effective management strategies will require the development of tissue markers to enhance early detection.
Presence of Epstein–Barr virus, cytomegalovirus and human papillomavirus in normal oral mucosa of HIV‐infected and renal transplant patients
Authors: Ammatuna P , Campisi G , Giovannelli L , Giambelluca D , Alaimo C , Mancuso S , Margiotta V
Published: December 2004

OBJECTIVES: To determine the prevalence of EBV‐DNA,CMV‐DNA and HPV‐DNA in oral healthy mucosa of HIV‐infected and renal transplant patients. To associate the detection of viral genomes with laboratory parameters of immunodeficiency, gender, antiretroviral and immunosuppressive therapy.

DESIGN: A cross‐sectional analysis of lingual and buccal cytobrushings from HIV‐infected and renal transplant patients.

SUBJECTS AND METHODS: Lingual and buccal cytobrushings were obtained from clinically normal oral mucosa of 57 HIV+, 40 renal transplant patients and 30 healthy uninfected controls, all matched for age at baseline of examination. Presence of EBV‐, CMV‐ and HPV‐DNA was assessed by polymerase chain reaction (PCR). We evaluated their association, in HIV+subjects, with gender, CD4+cell count, HIV‐RNA load, and antiretroviral therapy; and in renal transplant patients, with gender, CD4/CD8 ratio, and immunosuppressive therapy. Data were managed and analysed by Epi‐Info 6.0.

RESULTS: EBV‐DNA was detected in 42.1% of HIV+(24/57), in 65.0% of transplant patients (26/40), and in 16.6% of controls (5/30) (P= 0.03 andP= 0.0001, respectively). Furthermore, male gender in HIV+group was found to be significantly associated with the presence of EBV‐DNA (P= 0.02)vsfemales, after adjusting for CD4+cell count and HIV‐RNA load. CMV‐ and HPV‐DNA were detected in 3.5% and 7.0% of HIV+, and in none and 20.0% of transplant patients, respectively. No relationship was found between the epithelial detection of these two viruses and any parameter evaluated.

CONCLUSIONS: EBV genome was significantly detected in clinically normal oral mucosa of renal transplant and HIV+patients. A significant gender association was found among HIV+, suggesting that oral hairy leukoplakia (OHL) is more likely to occur in HIV+men than women.
Lipid peroxidation caused by oxygen radicals from Fusobacterium‐stimulated neutrophils as a possible model for the emergence of periodontitis
Authors: Sheikhi M , Bouhafs RKL , Hammarström K‐J , Jarstrand C
Published: December 2004

OBJECTIVE: The possible contribution of bacteria and polymorphonuclear neutrophils (PMN) to the disease process of periodontitis was evaluated.

DESIGN: Fusobacterium nucleatum has been associated with chronic adult periodontitis. Intracellular production and extracellular release of reactive oxygen species (ROS) by PMN stimulated by fusobacteria were evaluated. To estimate the potential extracellular damage that might be caused by the ROS, the lipid peroxidation (LPO) of an exogenous phospholipid, Intralipid, was assayed.

METHODS: The ROS production of PMN was studied by the nitroblue tetrazolium and chemiluminescence tests. The levels of malonaldehyde (MDA) and 4‐hydroxyalkenals were used to indicate LPO.

RESULTS: Fusobacterium nucleatum strains stimulated neutrophils to produce a large amount of ROS, independently of plasma complement factors. The two strains tested induced considerable intracellular, but no extracellular chemiluminescence responses during the first hour, indicating that ROS were released into phagosomes. However an incubation period of 4 h, in the presence of the extracellular lipid resulted in a high degree of LPO, presumably caused by ROS release from the Fusobacterium‐stimulated PMN. ROS production and lipid peroxidation could be counteracted by vitamin E.

CONCLUSION: In periodontitis local bacteria might stimulate PMN to release ROS, which cause inflammation and destruction.
Enhancement of matrix metalloproteinase (MMP)‐2 activity in gingival tissue and cultured fibroblasts from Down's syndrome patients
Authors: Komatsu T , Kubota E , Sakai N
Published: December 2004

OBJECTIVES: To identify one of the possible factors responsible for periodontal disease in Down's syndrome (trisomy 21) patients, we studied the enzyme activity and the mRNA expression pattern of matrix metalloproteinases (MMPs) of cultured gingival fibroblasts (GF) and fresh gingival tissues.

MATERIALS AND METHODS: Gingival tissue was used as the cell source and was biopsied at the time of dental treatment from nine patients with Down's syndrome and nine non‐Down's controls. GF were cultivated in serum‐free media for analyses of their MMP activities at the transcription or the protein level. The MMP activities in the supernates were measured by gelatin impregnated zymography. Relative levels of MMP mRNA from the cultured GF or freshly isolated gingival tissues were determined using the reverse transcription polymerase chain reaction (RT‐PCR).

RESULT AND CONCLUSIONS: The production of the active type of MMP‐2 in GF from Down's syndrome patients (D‐GF) was found to be significantly higher (P < 0.05) than that of the control GF (C‐GF) at the protein level. The mRNA expressions of membrane‐type1 MMP (MT1‐MMP) and MMP‐2 in D‐GF were constitutively augmented when compared with those of C‐GF. These findings suggest that specific increase of the active form of MMP‐2 in D‐GF may possibly be due to the concomitant expression of MT1‐MMP in the cultured cells, and this could be related to the pathogenesis of gingivitis/periodontitis associated with Down's syndrome patients.
Benign fibro‐osseous lesions of the jaw bones in Jamaica: analysis of 32 cases
Authors: Ogunsalu CO , Lewis A , Doonquah L
Published: December 2004

OBJECTIVE: It is intended to analyse all the cases of benign fibro‐osseous lesions seen at the two major public hospitals in Jamaica over a 15‐year period and to compare our result with what has been previously documented by other authors. No such analysis has been carried out in Jamaica or elsewhere in the English‐speaking Caribbean.

MATERIALS AND METHODS: The case files of patients histologically diagnosed to have a fibro‐osseous lesion at both the Kingston Public Hospital and the Cornwall Regional Hospital in Jamaica from 1980 to 1995 were retrieved and information about these lesions was documented. The WHO classification for benign fibro‐osseous lesions was used.

RESULTS: A total of 32 cases of benign fibro‐osseous lesions were recorded over the 15‐year period. Of these, 15 were histologically reported as fibrous dysplasia, 10 as ossifying fibroma, three as gigantiform cementoma, one each as periapical cemental dysplasia and cementoblastoma, and two cases of recurrent fibrous dysplasia. With the exception of gigantiform cementoma the age at presentation for these lesions is not consistent and this can be particularly noted for ossifying fibroma and fibrous dysplasia, both of which occurred between the age of 10 and 68 years.

CONCLUSION: These lesions are more common in females, furthermore it is suggested that the inconsistent age at presentation for some of these lesions may be peculiar to Jamaica, and may be due to delay in reporting a lesion by the patient, as routine dental examination is not a common practice.
New local hyperthermia using dextran magnetite complex (DM) for oral cavity: experimental study in normal hamster tongue
Authors: Wada S , Yue L , Tazawa K , Furuta I , Nagae H , Takemori S , Minamimura T
Published: December 2004

The possibility of dextran magnetite complex (DM) as a new hyperthermic material was examined in this study. DM suspension of 56 mg ml −1 iron concentration was locally injected into the normal tongue of golden hamster. DM injected tongues were heated by 500 kHz alternating current (AC) magnetic field and its serial changes in temperature were recorded at 30‐s intervals. The temperature of DM injected tongue was maintained at about 43.0–45.0°C for 30 min by changing the AC magnetic field intensity. While temperature elevations of the contralateral tongue and the rectum were only of minor degree. In experiment on the extent of heating area, there was correlation between volume of black stain area and amount of the injected DM suspension (Y =−18.1 + 1.94X, r= 0.931, P < 0.0001, n= 9). Histological examination after heating revealed brown uniform DM accumulation in the connective tissue between fibers of the tongue muscle. Except for vascular dilatations, no tissue damage was seen in the heated tongue. Thus, DM which has the possibility of selective and uniform heating in local hyperthermia might be useful for oral cancer therapy.
Peer relations in childhood
Authors: Hay Dale F. , Payne Alexandra , Chadwick Andrea
Published: December 2004

We present a developmental model that describes normal peer relations and highlights processes that underlie the emergence of problems with peers in childhood. We propose that children's relationships with peers begin in the first years of life, with stable individual differences and preferences for particular peers emerging by three years of age. Social skills that facilitate peer relationships consolidate in the preschool years, during which time peer groups become structured with respect to friendship groups, gender, and dominance relations; some children begin to be rejected by their peers. In later childhood some children develop entrenched problems with peer relationships, in terms of loneliness, bullying and victimisation. Underlying cognitive and emotional processes that facilitate successful peer relationships at all ages are identified, and the extent to which peer relations play a causal role in the genesis of disorder is evaluated. A review of the evidence suggests that, rather than a simple pathway from problematic peer relations to disorder, there is a reciprocal relationship between children's problems with peers and their psychological problems from infancy to adolescence.
Autism and pervasive developmental disorders
Authors: Volkmar Fred R. , Lord Catherine , Bailey Anthony , Schultz Robert T. , Klin Ami
Published: December 2004

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the ‘broader phenotype’ remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed.

Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.
Single nucleotide insertion in the 5′‐untranslated region of hepatitis C virus with clearance of the viral RNA in a liver transplant recipient during acute hepatitis B virus superinfection
Authors: Sergi Consolato , Arnold Joachim C. , Rau Wolfgang , Otto Herwart F. , Hofmann Walter J.
Published: December 2004

Abstract: Hepatitis C virus (HCV) infection is an important etiology in patients undergoing orthotopic liver transplantation (OLT) world‐wide. Antiviral therapy‐related clearance of HCV RNA may occur both in patients with chronic HCV infection and in transplanted patients for HCV‐related liver cirrhosis, but the role of the 5′‐untranslated region (UTR) of HCV containing the internal ribosome entry site (IRES), which directs the translation of the viral open reading frame has not hitherto been evaluated. We studied the 5′‐UTR in an HCV‐infected recipient of a liver graft that showed spontaneous clearance of HCV RNA during an acute hepatitis B virus (HBV) superinfection. Sequencing of the 5′‐UTR of HCV showed a nucleotide A insertion at position 193 of the IRES.
Changes in distribution spaces and cell permeability caused by ATP in the rat liver
Authors: Fernandes T. R. L. , Suzuki‐Kemmelmeier F. , De Oliveira Denize Silva , Bracht A.
Published: December 2004

Abstract: Aims/Background: Cellular and extracellular volume changes caused by ATP were investigated in the liver as well as the possible formation of diffusion barriers, which could be responsible for some of its metabolic effects. Methods: The experimental system was the bivascularly perfused rat liver. [14C]Sucrose and [3H]water were simultaneously injected into either the portal vein or the hepatic artery. Mean transit times, distribution spaces, variances and linear superimpositions were calculated. Results: In the portal system, ATP reduced the transit time in the great vessels, had little or no effect on sinusoidal and cellular spaces, but impaired the flow‐limited distribution of both [14C]sucrose and [3H]water. In the arterial bed ATP infused into either the portal vein or the hepatic artery produced vasodilation and increased the aqueous extra‐sucrose space. These effects were inhibited by Nω‐nitro‐L‐arginine methyl ester infused into the hepatic artery. Conclusions: Sucrose and extra‐sucrose space changes caused in the arterial bed by portally infused ATP are most probably analogous to the transhepatic vasodilation effect already described for the rabbit liver. Impairment of flow‐limited distribution of tracers in the sinusoidal bed indicates that ATP induces the formation of permeability barriers, which could be responsible for some of its metabolic effects.
Prognosis of a large cohort of patients with hepatocellular carcinoma in a single European centre
Authors: Herold Christoph , Reck Thomas , Fischler Peter , Ott Rudolf , Radespiel‐Troeger Martin , Ganslmayer Marion , Hohenberger Werner , Hahn Eckhart G. , Schuppan Detlef
Published: December 2004

Abstract: Background/Aim: Only a few follow up data are available for patients with hepatocellular carcinoma (HCC) in Europe and the USA. Therefore, we analysed all HCC patients admitted to our hospital between 1988 and 1999. Methods: We documented aetiology, stage (HCC: Okuda and UICC classifications, liver cirrhosis: Child‐Pugh score), and diagnostic and therapeutic measures of 281 consecutive HCC patients. Survival time was calculated as a function of staging and therapy. Results: Cirrhosis was diagnosed in all patients. Seventy‐two patients underwent liver resection, 28 liver transplantation, 31 transarterial chemoembolization and 14 percutaneous ethanol injection. One hundred and thirty‐six patients received no treatment. The Okuda and the Child‐Pugh classification predicted a significant decrease of median survival time, whereas the UICC classification was less powerful. Conclusions: HCC occurred only in patients with liver cirrhosis. Survival time correlated with therapy (or no therapy) and with the Child‐Pugh Score. In European patients the Okuda classification is superior to the UICC classification and should be compared to novel classification systems.
Fluorine‐18 FDG imaging in hepatocellular carcinoma using positron coincidence detection and single photon emission computed tomography
Authors: Verhoef C. , Valkema R. , De Man R. A. , Krenning E. P. , Yzermans J. N. M.
Published: December 2004

Abstract: Background/aims: We prospectively evaluated whether fluorine‐18 deoxyglucose (FDG) positron coincidence detection (PCD) or FDG single‐photon emission computed tomography (SPECT) provides additional benefits to our conventional preoperative evaluation of lesion detection in patients suspected to have hepatocellular carcinoma (HCC). Methods: Thirteen consecutive patients with a suspected HCC underwent conventional preoperative evaluation with ultrasonography (US), triple‐phase helical computed tomography (CT), superparamagnetic iron oxides (SPIO) enhanced magnetic resonance imaging (MRI) and serum α‐fetoprotein (AFP) level. All 13 patients had an FDG‐PCD and SPECT. These results were evaluated to assess the value of FDG‐PCD and SPECT in addition to US, SPIO‐enhanced MRI and triple‐phase helical CT. Results: Ten of the 13 (77%) patients had at least one histologically confirmed HCC without extrahepatic abdominal spread. The tumors ranged in size from 1 to 8 cm and the serum AFP ranged from 3 to 30 000 µg/l. Of these 10 patients, two patients had an increased tumor F‐FDG uptake (sensitivity of 20%); one patient with an AFP of 5 µg/l and a tumor size of maximum 4.5 cm and one patient with an AFP of 249 µg/l and a tumor size of maximum 2 cm. In three patients with a benign liver mass, FDG imaging with either PCD or SPECT was negative. There was no false positive finding. Conclusions: We found poor sensitivity of FDG‐PCD and FDG‐SPECT for the detection of HCC. There were no clear relations between AFP or tumor size and FDG uptake. Therefore, we conclude that FDG imaging with PCD or SPECT has no value in the preoperative work‐up for HCC in patients with cirrhosis.
Tropoelastin expression is up‐regulated during activation of hepatic stellate cells and in the livers of CCl4‐cirrhotic rats
Authors: Kanta Jiri , Dooley Steven , Delvoux Bert , Breuer Sebastian , D'Amico Thomas , Gressner Axel M.
Published: December 2004

Background/Aims:

Activated hepatic stellate cells (HSC) are regarded as the principal cells synthesizing extracellular matrix components in fibrotic liver. Elastin content is increased in cirrhotic livers, but the cellular source is not known. Contribution of HSC to the production of elastin was investigated.

Methods:

Expression of elastin in CCl4‐cirrhotic rat liver was studied by immunohistochemistry and in situ hybridization, liver myofibroblasts were identified in histological sections by α‐smooth muscle actin (α‐SMA) staining. LightCycler PCR and Northern blotting were used to detect tropoelastin mRNA in isolated HSC; tropoelastin protein was detected in the cells and in cell‐conditioned medium by Western blotting.

Results:

HSC, isolated from normal rat liver, displayed increasing tropoelastin mRNA expression during transdifferentiation in culture. Expression of tropoelastin mRNA was accompanied by the production of tropoelastin protein in vitro. Increased levels of tropoelastin transcripts were found in the connective tissue septa of CCl4‐cirrhotic rats and co‐localized with α‐SMA positive cells. Immunohistochemistry demonstrated elastin presence in the septa.

Conclusion:

HSC express tropoelastin and its expression increases during transdifferentiation to myofibroblast‐like cells.
Activation of cyclin‐dependent kinases CDC2 and CDK2 in hepatocellular carcinoma
Authors: Li Kay K. W. , Ng Irene O. L. , Fan S. T. , Albrecht Jeffrey H. , Yamashita Katsumi , Poon Randy Y. C.
Published: December 2004

Abstract: Background: The cyclin‐dependent kinases (CDKs) CDC2 and CDK2 are key regulators of the cell cycle. The expression of the CDK alone does not necessary reflect their true activities because they are highly regulated by post‐translational mechanisms. Human hepatocellular carcinoma (HCC) is one of the most common cancers in the world, but the kinase activities of CDKs in HCC have not been examined.

Methods: Here we examined the protein expression and kinase activities associated with CDC2 and CDK2 in HCC and the corresponding non‐tumorous liver tissues.

Results: CDC2 and CDK2 are activated in HCC in over 70% and 80% of the cases, respectively, but have little correlation with clinical parameters and PCNA expression. Interestingly, PCNA was readily detectable in extracts from non‐tumorous liver, but more than 60% of samples contain higher concentration of PCNA in HCC than the corresponding non‐tumorous tissues. CDC2 and CDK2 are generally activated in the same HCC samples, but the extent of their activation varied significantly, suggesting that the pathways leading to the activation of CDC2 and CDK2 can be regulated independently. Both positive regulators of CDK activity like cyclins and CDKs, and negative regulators of CDK activity like p21CIP1/WAF1 and Thr14/Tyr15 phosphorylation were up‐regulated in HCC. Conclusion: CDC2 and CDK2 are activated in HCC, and this may be due to a complex interplay between the level of the cyclin, CDK, CDK inhibitors, and inhibitory phosphorylation.
An electron microscopic and morphometric study of ursodeoxycholic effect in primary biliary cirrhosis
Authors: Neuman Manuela G. , Cameron Ross G. , Haber Julia A. , Katz Gady G. , Blendis Laurence M.
Published: December 2004

Abstract: Background/aims: Primary biliary cirrhosis (PBC) is a chronic liver disease that results in cholestasis and bile duct loss. Ursodeoxycholic acid (UDCA) has been shown to reduce hepatocellular damage in PBC. The study attempted to quantify perisinusoidal collagenization and the number of apoptotic bodies in PBC liver biopsies from patients in a randomized control trial treated with UDCA compared to those who received placebo. Methods: Twenty‐eight patients with PBC (10 cirrhotic, 18 non‐cirrhotic; 13 treated with UDCA, 15 treated with placebo) were compared with 32 controls with normal hepatic histology on light mictoscopy. Liver biopsies were examined for degree of perisinusoidal fibrosis and apoptotic activity using electron microscopy. Results: The degree of perisinusoidal fibrosis and apoptotic activity was similar in pretreatment biopsies of UDCA and placebo‐treated patients. After two years of placebo, patients showed a significant increase in fibrosis (P < 0.001). In contrast, there were no changes in non‐cirrhotic and a decrease in fibrosis in cirrhotic patients given UDCA.

At baseline, PBC patients had higher numbers (apoptotic cells/100 hepatocytes ± SE) of apoptotic cells (7 ± 3), than controls (2 ± 0.5) (P < 0.05), with no difference between cirrhotic and non‐cirrhotic patients in the two groups of patients. After two years, the numbers of apoptotic cells in UDCA‐treated patients decreased significantly compared to baseline (3 ± 2) (P < 0.05); with placebo patients the number of apoptotic cells increased (12 ± 5) (P < 0.05). Conclusion: Treatment with UDCA prevents the deposition of perisinusoidal collagen and reduces the apoptotic activity in PBC patients after 2 years of therapy.
Heterogeneous hepatic enhancement on CT angiography in idiopathic portal hypertension
Authors: Waguri Nobuo , Suda Takeshi , Kamura Takeshi , Aoyagi Yutaka
Published: December 2004

Background:

Idiopathic portal hypertension is an uncommon condition characterized by presinusoidal portal perfusion disturbance without known causes.

Methods:

In the present study, portal and arterial perfusion dynamics were evaluated in two cases with idiopathic portal hypertension using computed tomography during arterial portography and hepatic arteriography. Ten cases with liver cirrhosis were also studied as a reference.

Results:

In cases with idiopathic portal hypertension, portal perfusion was conspicuously heterogeneous and decreased especially at the periphery of the liver where arterial perfusion was reciprocally increased. When the spatial heterogeneity of an enhancement of the liver was quantified using a densitometric analysis of computed tomography during hepatic arteriography images, the densities at the periphery were higher and varied more than those of the inner areas in cases with idiopathic portal hypertension. In contrast, the densities did not vary between the periphery and the inner areas at the cases with liver cirrhosis.

Conclusions:

The heterogeneous increase of arterial perfusion in periphery of the liver may be an important feature of idiopathic portal hypertension.
A class of modified high‐order autoregressive models with improved resolution of low‐frequency cycles
Authors: Morton Alex S. , Tunnicliffe‐Wilson Granville
Published: December 2004

Abstract. We consider regularly sampled processes that have most of their spectral power at low frequencies. A simple example of such a process is used to demonstrate that the standard autoregressive (AR) model, with its order selected by an information criterion, can provide a poor approximation to the process. In particular, it can result in poor multi‐step predictions. We propose instead the use of a class ofpth order AR models obtained by the addition of a pre‐specifiedpth order moving average term. We present a re‐parameterization of this model and show that with a low order it can provide a very good approximation to the process and its multi‐step predictions. Methods of model identification and estimation are presented, based on a transformed sample spectrum, and modified partial autocorrelations. The method is also illustrated on a real example.
Inference for Autocorrelations in the Possible Presence of a Unit Root
Authors: Politis Dimitris N. , Romano Joseph P. , Wolf Michael
Published: December 2004

Abstract. We consider the problem of making inference for the autocorrelations of a time series in the possible presence of a unit root. Even when the underlying series is assumed to be strictly stationary, the robustness against a unit root is a desirable property to ensure good finite‐sample coverage in case the series has a near unit root. In addition to discussing a confidence interval for the autocorrelation at a given lag, we also consider a simultaneous confidence band for the firstkautocorrelations. We suggest the use of the subsampling method applied to properly studentized statistics, which results in confidence intervals and bands with asymptotically correct coverage probability. An application to practical model selection is given, while a simulation study examines finite‐sample performance.
Assessment of Local Influence in GARCH Processes
Authors: Zhang Xibin
Published: December 2004

Abstract. This paper investigates the problem of assessing local influence of small perturbations in GARCH processes. First, we examine the local influence on the Lagrange multiplier (LM) statistic. Second, we assess the local influence on the pseudo‐likelihood of the GARCH model. We find that short patches of high volatility observations that have a strong influence on the LM statistic may not necessarily be influential on the pseudo‐likelihood. This is mainly due to the fact that the effects of high volatility could be incorporated through GARCH modeling. An empirical example is presented to illustrate the effectiveness of the proposed methods. It is interesting to note that observations which have a very strong influence on the LM statistic are far less influential on the GARCH pseudo‐likelihood, suggesting that under the GARCH model they should not be regarded as outliers.
Live trapping to monitor small mammals in Britain
Authors: FLOWERDEW JOHN R. , SHORE RICHARD F. , POULTON SIMON M. C. , SPARKS TIMOTHY H.
Published: December 2004

1. The use of live trapping in Britain to monitor small mammal distribution and population fluctuations is reviewed. Four small mammal monitoring programmes from Britain, the results of which are either partially or wholly unpublished, were examined to determine the nature and extent of information that can be gathered from long‐term and/or large‐scale live‐trapping programmes, the degree to which such information can be extrapolated across habitats, and the likely precision with which long‐term changes in numbers can be quantified. The most extensive of the surveys examined were The Mammal Society National Woodland Small Rodent Survey and the ADAS Hedgerow Survey. These monitored wood mouseApodemus sylvaticus, bank voleClethrionomys glareolusand, in the ADAS survey only, common shrewSorex araneuspopulation fluctuations on a broad spatial scale.

2. The studies provided evidence of population synchrony and demonstrated quantitatively the effects of mast crops and local food supplies on rodent dynamics. Evidence of population synchrony between sites for wood mice and shrews suggests that it may be possible to extrapolate population changes from site‐specific to national scenarios. However, this may be problematic for some species and across habitats, although comparison of the data from the woodland and hedgerow surveys suggests that there may be a degree of long‐term synchrony in bank vole populations between the two habitats.

3. Analysis of the capture data from the two surveys indicated that annual changes of 3–11% from the population mean would be detectable with 85% power if monitoring is carried out for 10 years on 50 sites; increasing site replication further is unlikely to result in a significant increase in precision.

4. The nature of the information provided by live trapping with grids, as carried out in The Mammal Society and the ADAS surveys, is compared with that obtained from line trapping and from a range of indirect techniques. It is suggested that future monitoring will need to take an integrated approach in which information from direct and indirect monitoring of small mammal populations is linked with broad‐scale data on changes in habitat availability.
Sclerosing meningioma: immunohistochemical analysis of five cases
Authors: Kim N. R. , Im S.‐H. , Chung C. K. , Suh Y.‐L. , Choe G. , Chi J. G.
Published: December 2004

Sclerosing meningioma is a rare morphologic subtype of meningioma and may be mistaken for atypical or malignant meningioma and astrocytoma or schwannoma because of marked collagen deposits and a sparse population of cells with little resemblance to meningothelial cells. Authors describe the histopathologic and immunophenotypic features of five cases of sclerosing meningioma. Histologically, all the cases consisted of paucicellular collagenous tissue containing spindle cells with or without small foci of meningothelial cell proliferation. The morphology and immunohistochemical profile of the spindle cells were different from those of conventional meningothelial cells. The meningothelial cells showed a typical immunoreactivity of conventional meningiomas, while the spindle cells displayed a strong expression of vimentin. The Ki‐67 labelling index was uniformly low in all cases, and none of cases expressed p53 protein. In summary, the recognition of meningothelial cells in massively sclerotic lesions is helpful for a correct diagnosis. In the cases with a total absence of meningothelial cells, however, the vague collagenous whorls are more diagnostic rather than immunohistochemistry. Considering association with clear cell meningioma, prospective and retrospective long‐term follow‐up is necessary for deciding whether reminiscent clear cell meningiomas should be separated from sclerosing meningioma or not.
Disappearance of the post‐lesional laminin immunopositivity of brain vessels is parallel with the formation of gliovascular junctions and common basal lamina. A double‐labelling immunohistochemical study
Authors: Szabó A. , Kálmán M.
Published: December 2004

Previous studies revealed that during development the laminin immunopositivity gradually disappeared from the brain vessels, but temporarily re‐appeared in them around lesions. The question of the present study was the correlation between the post‐lesional vascular immunopositivity to laminin and the glial reaction. Following stab wounds, double fluorescent immunohistochemical labelling was performed against laminin (using a polyclonal antiserum against laminin 1) and glial fibrillary acidic protein. A number of vessels exhibited intense immunopositivity to laminin within the lesioned tissue. Where these laminin immunopositive vessels entered the perilesional brain substance, the astroglia formed contacts on them, and the separate vascular and glial basal laminae fused. The disappearance of the post‐lesional laminin immunopositivity seemed to coincide with these phenomena. When monoclonal antibodies were applied against the β1 and γ1 laminin chains, vessels proved to be immunopositive at the lesion, but none in the intact brain tissue. No immunoreactivity was detected in the cases of α2 and β2 chains. The results suggest that the disappearance of laminin immunopositivity may be attributed to that the epitopes become inaccessible for antibodies owing to the formation of gliovascular junctions and common basal lamina between astroglia and vessel. The possible role of an alteration in the laminin composition and the effect of fixation are discussed.
S100A5: a marker of recurrence in WHO grade I meningiomas
Authors: Hancq S. , Salmon I. , Brotchi J. , De Witte O. , Gabius H.‐J. , Heizmann C. W. , Kiss R. , Decaestecker C.
Published: December 2004

Some WHO grade I intracranial meningiomas resected from the same sites and with the same quality of resection (Simpson's grading scale) recur, while others do not. The reasons for this variability in occurrence of recurrence have not yet been determined. We therefore investigated the prognostic recurrence value of seven biological markers on a series of completely resected WHO grade I meningiomas. For this purpose, we analysed a series of 33 WHO grade I meningiomas totally resected between 1980 and 1990 (a follow‐up of 10 years), including 14 cases of recurrence. The fixed tumour material from each meningioma was submitted to histochemical analyses targeting galectin‐3 and its binding sites, the S100A5, S100A6 and S100B proteins, and cathepsin‐B and ‐D. The levels of expression were assessed semi‐quantitatively (in terms of the staining intensity and the labelling index) and submitted to uni‐ and multivariate analyses. Of all the markers investigated, only S100A5 expression can be associated with any significant prognostic value in the matter of recurrence. More particularly, the meningiomas with high levels of S100A5 staining intensity either did not recur, or recurred later than those with a low immunopositive S100A5 intensity (P = 0.004). Cox regression analyses demonstrated that this latter marker was associated  with  significant  prognostic  values  independent  of the patients’ ages. Furthermore, the combination of the patients’ ages and S100A5 staining intensity permitted the identification of a group with a particularly high risk of recurrence, that is, the patients younger than 55 and with meningiomas exhibiting low S100A5 intensities (P = 0.001). In conclusion, the S100A5 protein could play a role in the recurrence of totally resected WHO grade I meningiomas.
Brainstem motor nuclei respond differentially to degenerative disease in the mutant mouse wobbler
Authors: Clowry G. J. , McHanwell S.
Published: December 2004

Degenerative motoneurone diseases, whether in humans, animals, or transgenic mouse models, do not affect all types of motoneurone to the same degree. Understanding the relative differences in vulnerability of certain motor pools may be the key to developing therapies. Expression of calbindin (CB) and parvalbumin (PV) immunoreactivity, which are potentially neuroprotective calcium‐binding proteins, and NADPH‐diaphorase (NADPH‐d) histochemical reactivity, a marker for neurodegeneration, was studied in brainstem sections from mutant wobbler mice and their normal littermates during the motoneurone degeneration phase (3–8 weeks of age). The motor trigeminal and facial nuclei reacted in a manner previously observed in spinal somatic motoneurones in the wobbler. Many motoneurones expressed moderate NADPH‐d reactivity, correlated with the appearance of vacuolated motoneurones in Nissl‐stained sections. This was not observed in littermate controls. Motoneurone counts from Nissl‐stained sections from 14‐month‐old wobblers and littermates revealed significantly fewer (approximately 27%) motoneurones in the trigeminal nucleus of wobblers. In contrast, the wobbler hypoglossal nucleus contained neither vacuolated nor NADPH‐d reactive motoneurones. However, expression of CB immunoreactivity by the majority of wobbler hypoglossal motoneurones was observed but not in littermate controls or in any other motor nucleus. Counts in older animals showed a smaller but still significant difference in motoneurone number between wobblers and controls (approximately 9% reduction). Finally, the wobbler abducens nucleus displayed neither vacuolated neurones, nor NADPH‐d reactivity nor CB immunoreactivity. Motor nuclei innervating extraocular muscles appear to be protected in many forms of motoneurone disease in man and other species. However, there were still markedly fewer abducens motoneurones in the old wobblers compared to controls (approximately 29% reduction). Sparing of oculomotor neurones in other diseases has been attributed to their relatively high PV expression, which we also observed in the abducens nucleus of both wobblers and littermates, and to a lesser extent in the other motor nuclei too. In conclusion, our results suggest that, in the wobbler mouse, motoneurone degeneration may occur without overt signs such as cell body vacuolation and NADPH‐d expression. Induced CB expression may be neuroprotective but that constitutive expression of PV may not.