bluuebunny/crossref_metadata_2025 huggingface dataset:
F‐statistics under alternation of sexual and asexual reproduction: a model and data from schistosomes (platyhelminth parasites)
Authors: PRUGNOLLE FRANCK , ROZE DENIS , THÉRON ANDRÉ , DE MEEÛS THIERRY
Published: April 2005

Accurate inferences on population genetics data require a sound underlying theoretical null model. Nearly nothing is known about the gene dynamics of organisms with complex life cycles precluding any biological interpretation of population genetics parameters. In this article, we used an infinite island model to derive the expectations of those parameters for the life cycle of a dioecious organism obligatorily alternating sexual and asexual reproductions as it is the case for schistosomes (plathyhelminth parasites). This model allowed us to investigate the effects of the degree of mixing among individuals coming from different subpopulations at each new generation (represented in the model by the migration rates before and after clonal reproductions) and the variance in the reproductive success of individuals during the clonal phase. We also consider the effects of different migration rates and degrees of clonal reproductive skew between male and female individuals. Results show that the variance in the reproductive success of clones is very important in shaping the distribution of the genetic variability both within and among subpopulations. Thus, higher variance in the reproductive success of clones generates heterozygous excesses within subpopulations and also increases genetic differentiation between them. Migration occurring before and after asexual reproduction has different effects on the patterns of FIS and FST. When males and females display different degrees of reproductive skew or migration rates, we observe differences in their respective population genetic structure. While results of the model apply to any organism alternating sexual and clonal reproductions (e.g. all parasitic trematodes, many plants, and all aphididae), we finally confront some of these theoretical expectations to empirical data from Schistosoma mansoni infecting Rattus rattus in Guadeloupe.
Phylogeography of an east Australian wet‐forest bird, the satin bowerbird (Ptilonorhynchus violaceus), derived from mtDNA, and its relationship to morphology
Authors: NICHOLLS J. A. , AUSTIN J. J.
Published: April 2005

Australian wet forests have undergone a contraction in range since the mid‐Tertiary, resulting in a fragmented distribution along the east Australian coast incorporating several biogeographical barriers. Variation in mitochondrial DNA and morphology within the satin bowerbird was used to examine biogeographical structure throughout almost the entire geographical extent of these wet forest fragments. We used several genetic analysis techniques, nested clade and barrier analyses, that use patterns inherent in the data to describe the spatial structuring. We also examined the validity of the two previously described satin bowerbird subspecies that are separated by well‐defined biogeographical barriers and tested existing hypotheses that propose divergence occurs within each subspecies across two other barriers, the Black Mountain corridor and the Hunter Valley. Our data showed that the two subspecies were genetically and morphologically divergent. The northern subspecies, found in the Wet Tropics region of Queensland, showed little divergence across the Black Mountain corridor, a barrier found to be significant in other Wet Tropics species. Biogeographical structure was found through southeastern Australia; three geographically isolated populations showed genetic differentiation, although minimal divergence was found across the proposed Hunter Valley barrier. A novel barrier was found separating inland and coastal populations in southern New South Wales. Little morphological divergence was observed within subspecies, bar a trend for birds to be larger in the more southerly parts of the species’ range. The results from both novel and well‐established genetic analyses were similar, providing greater confidence in the conclusions about spatial divergence and supporting the validity of these new techniques.
Soluble cellular adhesion molecules, selectins, VEGF and endothelin‐1 in patients with Wuchereria bancrofti infection and association with clinical status
Authors: Esterre P. , Plichart C. , Huin‐Blondey M. O. , Nguyen L. N.
Published: April 2005

Lymphatic filariasis, a mosquito‐transmitted disease commonly known as Bancroftian filariasis, is characterized by debilitating pathology linked to the progression of lymphoedema to a chronic state of elephantiasis. We performed longitudinal measurements of endothelial adhesion and angiogenic molecules in 63 Polynesian patients living in an hyperendemic focus of Wuchereria bancrofti. Decreased serum concentrations of soluble (s‐) L selectin (CD62L) were noticed in sera of of patients with chronic conditions (hydrocele and elephantiasis). Chyluria was associated with increased vascular endothelial growth factor (VEGF) levels, whereas elephantiasis presented a high endothelin‐1 (ET‐1) profile. By contrast, increased serum concentrations of soluble intercellular (sICAM‐1, CD54), but not of vascular cell (sVCAM‐1, CD106), adhesion molecules were observed in sera of patients with bacterial lymphangitis used as controls. These trends are consistent with the increased permeability of vascular structures, a major clinical feature observed in acute lymphatic pathology (of bacterial or filarial origin), and of fundamental differences in the pathogenesis of hydrocele and elephantiasis. Using markers correlated with the clinical status (high ET‐1 and VEGF levels for elephantiasis and chyluria, respectively; low CD62L levels for hydrocoele and elephantiasis) it should be possible to monitor disease progression in lymphatic filariasis.
PD‐L2+ dendritic cells and PD‐1+ CD4+ T cells in schistosomiasis correlate with morbidity
Authors: Colley D. G. , Sasser L. E. , Reed A. M.
Published: April 2005

Dendritic cells (DC) are critical antigen‐presenting cells for the induction and control of immune responses. PD‐L2 (B7‐DC) is a regulatory ligand on subpopulations of DC, and binds to the co‐regulatory receptor PD‐1, present on some activated T lymphocytes, leading to down‐regulation. We now show that very early during experimental schistosomiasis (by 5 weeks) a significantly higher proportion of splenic CD11c+/B220– DC express PD‐L2, and by 6 weeks after infection a higher proportion of splenic CD4 T cells express PD‐1. In this CBA/J mouse/Schistosoma mansoni chronic infection model we have shown that most mice develop moderate morbidity (Moderate Splenomegaly Syndrome, MSS), while some parallel‐infected mice express different immune characteristics and die or develop severe morbidity (Hypersplenomegaly Syndrome, HSS). We now report a positive correlation between the proportion of splenic CD11c+/B220– DC that express PD‐L2 and showing MSS. In contrast, there is an inverse correlation between the proportion of splenic CD3+/CD4+ T lymphocytes that express PD‐1 and showing MSS. The data demonstrate that schistosomes can induce sustained elevated percentages of PD‐L2‐expressing, B220–negative DC. Furthermore, when this potentially immunoregulatory environment occurs chronically, infected mice are most likely to have developed MSS, expressing moderate morbidity.
First record of the grape leafhopper Erythroneura vulnerata Fitch (Hom., Cicadellidae) in Europe
Authors: Duso C. , Bressan A. , Mazzon L. , Girolami V.
Published: April 2005

Abstract:  The leafhopper Erythroneura vulnerata Fitch is native to North America, where it infests wild and cultivated grapes. In July 2004, E. vulnerata was recorded for the first time on Vitis vinifera L. (cv. Cabernet Sauvignon) in north‐eastern Italy (Veneto region). This record is assumed to be the first in Europe. Preliminary observations on the pest distribution, seasonal abundance and the extent of symptoms in north‐eastern Italy are reported.
Cytochemical Ca2+ Distribution in Activated Discoglossus pictus Eggs: A Gradient in the Predetermined Site of Fertilization
Authors: Gualtieri Roberto , Campanella Chiara , Andreuccetti Piero
Published: April 2005

The K‐pyroantimonate/OsO4 (PA) cytochemical method coupled with EGTA and X‐ray microanalytical controls has been used to localize Ca2+ at egg activation in Discoglossus pictus eggs. The results show that: 1) the PA method is able to selectively localize Ca2+ pools mobilized by activating stimuli; 2) the smooth endoplasmic reticulum (SER) elements located in the animal dimple region, i.e. in the predetermined site of fertilization, are the first egg components labeled by precipitates; 3) a decreasing gradient of precipitates is present from the center beyond the boundaries of the dimple region; 4) precipitates are lacking in the remainder of the egg even at late times after activation.

The possibilities are discussed that a) SER is the major Ca2+‐releasing store at activation in Discoglossus, and b) the observed gradient of pyroantimonate‐detected Ca2+ reflects an ionic Ca2+ gradient.
Protease‐Induced Formation of the Sperm Acrosomal Filament
Authors: Lindsay LeAnn L. , Clark Wallis H.
Published: April 2005

Filament extension during the sperm acrosome reaction in Sicyonia ingentis is triggered by an egg trypsin‐like protease whose action can be mimicked using trypsin. Using biotinylated trypsin and either a fluorescently‐labeled or colloidal gold‐labeled antibody to biotin, trypsin binding was localized to the anterior granule of the sperm which is exposed upon acrosomal exocytosis. The binding was to proteinaceous material at the base of the granule juxtaposed to the inner acrosomal membrane. Other labeled proteins also bound in the same pattern but only in the presence of unlabeled trypsin; non‐proteolytic proteins did not induce filament formation. Binding of all proteins tested occurred slowly over a period of about 30 min. A minimum of 30 min of trypsin exposure was required in order to trigger filament formation, and increasing trypsin concentration did not reduce this time requirement. These results indicate that the protease slowly uncovers a binding site for itself (or other proteins), and then its proteolytic activity is again required to induce filament formation. The protease kallikrein appeared to be a more potent inducer than trypsin, while thrombin and clostripain had no apparent inducing activity.
Retinoic Acid Treatment Induces the Ectopic Exporession of Retinoic Acid Receptor β Gene and Excessive Cell Death in the Embryonic Mouse Face
Authors: Osumi‐Yamashita Noriko , Iseki Sachiko , Noji Sumihare , Nohno Tsutomu , Koyama Eiki , Taniguchi Shigehiko , Doi Hirofumi , Eto Kazuhiro
Published: April 2005

Maternal treatment with 100 mg/kg of retinoic acid (RA) on day 9 of gestation in mice caused craniofacial abnormalities of the mandibulofacial dysostosis type. The abnormal morphology was attributed to the excessive cell death in the dorsal aspects of the maxillary and mandibular prominences of the first pharyngeal arch and in the proximal region of the mandibular prominence. To investigate the expression of the RA receptor (RAR) genes in abnormal face morphogenesis, in situ hybridization was performed. The distribution patterns of RAR α and γ transcripts were not altered in the treated embryos. By contrast, the teratogenic dose of RA increased the level of RAR β transcripts, as early as 3 hr after RA‐treatment, in the regions where the RAR β expression is at a low level in normal development. The increase of RAR β transcripts was detected by 12 hr, and declined to the low level within 24 hr after the treatment. The regions where ectopic expression of RAR β gene was observed included the areas where the excessive cell death occurred 9–12 hr after RA‐treatment. These results suggest that ectopic induction of RAR β by RA may lead to the excessive cell death, threfore may cause abnormal morphogenesis.
Identification of GTP‐Binding Proteins by ADP‐Ribosylation in the Presence of Cholera Toxin, Pertussis Toxin and Botulinum Toxin D in Plasma Membrane Isolated from Eggs and Embryos of Sea Urchin
Authors: Kamata Yasuyuki , Furuya Shigehisa , Takei‐Mikami Kaori , Fujiwara Akiko , Yasumasu Ikuo
Published: April 2005

In plasma membrane fraction isolated from eggs and embryos of sea urchin, 32P‐labeled proteins were found on the fluorographs of SDS‐polyacrylamide gel electrophoresis, performed after an exposure of the fraction to [adenylate‐32P] nicotinamide adenine dinucleotide in the presence of cholera toxin, pertussis toxin or botulinum toxin D. The molecular weights of proteins, thus ADP‐ribosylated in the presence of cholera toxin and pertussis toxin are 45 and 39 K, which correspond to Gs and Gi or Go, respectively. Protein with the molecular weight of 24 K, labeled in the presence of botulinum toxin D, corresponds to small molecular weight G‐protein. The labeling intensity of 45 K protein, probably proportional to its amount, became high at the blastula stage. The labeling intensity of 39 K protein was hardly altered up to the blastula stage. The labeling intensity of 24 K protein increased after fertilization and further increase occurred at the blastula stage. At the gastrula stage, the labeling intensities of these proteins became somewhat lower than at the blastula stage. Transmembrane signaling system, in which these G‐proteins are involved, is probably altered in its function during early development.
Efficient Induction of Sporulation of Dictyostelium Prespore Cells by 8‐Bromocyclic AMP under Both Submerged‐ and Shaken‐Culture Conditions and Involvement of Protein Kinase(s) in Its Action
Authors: Maeda Mineko
Published: April 2005

It is important to establish an experimental system in which sporulation of Dictyostelium can be induced at high cell densities to obtain sufficient amounts of materials for analysis of the molecular events leading to sporulation. 8‐Bromo cAMP (Br‐cAMP) was found to be effective for inducing sporulation by prespore cells of Dictyostelium discoideum NC4 at high cell densities under both submerged‐ and shaken‐culture conditions. Ultrastructural studies revealed that the morphological changes associated with this sporulation proceeded normally in vitro. The effect of Br‐cAMP was inhibited by two protein kinase inhibitors, K252a and staurosporine. Protein‐phosphorylation experiments showed that Br‐cAMP induced increased phosphorylations of a 96 kDa spore coat protein (SP96) and a protein with a mobility corresponding to a molecular weight of 50 kDa (p50‐4). The protein kinase inhibitor K252a blocked the phosphorylations of both proteins. These proteins may be targets of particular protein kinase(s) that is activated by Br‐cAMP. These findings indicate that the present experimental system should be useful for elucidating the molecular events involved in normal sporulation and the mechanism by which Br‐cAMP induces sporulation in vitro.
Concerted Movement of Prestalk Cells in Migrating Slugs of Dictyostelium Revealed by the Localization of Myosin
Authors: Yumura Shigehiko , Kurata Kiyoshi , Kitanishi‐Yumura Toshiko
Published: April 2005

Localization of myosin in slugs of the cellular slime mold Dictyostelium discoideum was investigated by an immunofluorescence technique. Myosin is thought to provide the molecular machinery for cellular movement. We found that myosin could be visualized as c‐shaped fluorescence at the cortex of prestalk cells in a migrating slug, and that the open regions of all c‐shaped fluorescence point in the direction of the slug's migration. We reported previously that the c‐shaped fluorescence of myosin can be seen at the cortex of the tail region of actively locomoting cells at the unicellular stage (39, 41). These results suggest that prestalk cells move actively in the slug, and that their direction of movement, which can be identified from the polarity of c‐shaped fluorescence, correspond with the direction of the slug's migration. The distribution of c‐shaped fluorescence in slugs during migration, phototaxis and avoidance of ammonia strongly suggests that the slug's behavior is controlled by the concerted movement of prestalk cells.
Lipids of Xenopus laevis Spermatozoa
Authors: Bernardini Giovanni , Gornati Rosalba , Rapelli Silvana , Rossi Federica , Berra Bruno
Published: April 2005

Xenopus laevis sperm lipid composition has been studied. The cholesterol content of Xenopus spermatozoa is 194 μ/mg DNA. Their content of glycolipids and phospholipids (measured as inorganic phosphorus) is respectively 40 and 27 μ/mg DNA. The phospholipid pattern is quite homogeneous and all the principal molecular species are present. In all the examined samples, a glycolipid with low mobility, not yet structurally identified, is present. Finally, using as a probe filipin, we have observed cholesterol distribution on the Xenopus sperm plasma membrane by freeze‐fracture. In agreement with the chemical data here presented, Xenopus spermatozoa are heavily labelled by filipin. The filipin‐cholesterol complexes seem to be distributed on the entire sperm plasma membrane and appear as protuberances on the P face, suggesting that most of the cholesterol reside in the inner leaflet of the membrane.
Relationships between Presence of the Eye Cup and Maintenance of Lens‐Forming Capacity in Larval Xenopus laevis
Authors: Bosco Luigi , Filoni Sergio
Published: April 2005

The lentectomized eye of larval Xenopus laevis can regenerate a lens by a process of lens‐transdifferentiation of the cornea and pericorneal epidermis. These tissues can form the lens only when they become in direct communication with the environment of the vitreous chamber (neural retina) indicating that the eye cup plays a fundamental role in this process.

In this work the role of the eye cup in the maintainance of the lens‐forming capacity of the cornea and pericorneal epidermis was studied by allowing these tissues to cover the enucleated orbit for different periods, and then implanting them into the vitreous chamber of the contralateral eye. Under these experimental conditions the maintainance of the lens‐forming capacity of the cornea and pericorneal epidermis showed no significant correlation with the time from enucleation to implantation.
Spatial Pattern of Expression of Cyl Actin‐β‐Galactosidase Fusion Genes injected into Sea Urchin Eggs
Authors: Collura Randall , Katula Karen S.
Published: April 2005

The Cyl actin gene of the sea urchin Strongylocentrotus purpuratus displays a pattern of expression that is correlated with cell division; the gene is initially activated in all cells of the early blastula stage embryo, but after 18 hours Cyl actin transcripts disappear from the aboral ectoderm at a time when these cells are withdrawing from the cell cycle. As part of our investigation of the transcriptional regulation of Cyl, we tested various Cyl‐β‐gal fusion genes for their spatial pattern of expression by microinjection into fertilized eggs of the sea urchin, Lytechinus pictus. The plasmid Cyl‐β‐gal containing 2.5 kb of upstream sequence displayed a pattern of expression which reflected the endogenous Cyl actin gene. Most of the staining was seen in the gut, oral ectoderm, and mesenchyme cells, while fewer embryos had stained cells in the aboral ectoderm cells. Deletions in the upstream sequences to‐195 bp resulted in a decrease in the mean number of stained cells, but the overall pattern of expression was similar to Cyl‐β‐gal. These results indicate that sequences required for correct spatial expression of Cyl are located in the first 195 bp upstream of the Cyl start of transcription and/or within the first intron. A mutation in the highly conserved serum response element and an adjacent protein binding site did not increase the percentage of aboral ectoderm staining nor decrease the relative level of CAT activity from a Cyl‐CAT fusion gene containing the same mutation. The implications of these rsults are discussed.
Differentiation of Secondary Spermatogonia to Primary Spermatocytes by Mammalian Follicle‐Stimulating Hormone in Organ Culture of Testes Fragments from the Newt, Cynops pyrrhogaster
Authors: Ji Zai‐Si , Kubokawa Kaoru , Ishii Susumu , Abé Shin‐Ichi
Published: April 2005

In order to elucidate essential factors responsible for the initiation and promotion of spermatogenesis, we developed an organ culture system with a chemically defined medium. When newt testes fragments, consisting of somatic cells and germ cells almost exclusively secondary spermatogonia, were cultured in control medium for three weeks, most of the testicular cysts still contained only secondary spermatogonia. On the other hand, in the medium supplemented with various kinds of hormones and vitamins primary spermatocytes (zygotene‐pachytene) appeared in about 60% of the cysts by the second week. Selective removal of specific hormones and vitamins revealed that follicle‐stimulating hormone (FSH) alone was indispensable and sufficient for the differentiation of secondary spermatogonia to primary spermatocytes. Neither the addition of luteinizing hormone (LH) nor androgens (testosterone and 5α‐dihydrotestosterone) to the control medium stimulated differentiation. Consistent with these findings was the fact that radioreceptor assays revealed high affinity specific binding sites for FSH but none for LH. Since our ultrastructural studies revealed a major loss of contact between spermatogonia and Sertoli cells following exposure to FSH, we suggest that FSH triggers differentiation of spermatogonia by acting on Sertoli cells which in turn act on spermatogonia.
Expression of Na+, K+‐ATPase α‐Subunit in Animalized and Vegetalized Embryos of the Sea Urchin, Hemicentrotus pulcherrimus.
Authors: Mitsunaga‐Nakatsubo Keiko , Kanda Miyuki , Yamazaki Ken , Kawashita Hiroto , Fujiwara Akiko , Yamada Kazumi , Akasaka Koji , Shimada Hiraku , Yasumasu Ikuo
Published: April 2005

A marked increase in the Na+, K+‐ATPase activity of sea urchin embryos occurred following an elevation of its mRNA level, revealed by Northern blotting analysis, in developmental period between the swimming blastula and the late gastrula stage. cDNA clone of Na+, K+‐ATPase α‐subunit, obtained from γgt10 cDNA library of sea urchin gastrulae, was digested with EcoRl ad Hindlll. The obtained 268 bp cDNA fragment, hybridized to a 4.6 Kb RNA, was used as probe for Northern blotting analysis. The level of Na+, K+‐ATPase mRNA was higher in embryo‐wall cell fraction isolated from late gastrulae (ectoderm cells) than the level in the bag fraction, containing mesenchyme cells (mesoderm cells) and archenteron (endoderm cells). The activity of Na+, K+‐ATPase and the level of its mRNA were higher in animalized embryos obtained by pulse treatment with A23187 for 3 hr, starting at the 8–16 cell stage and were considerably lower in vegetalized embryos induced by 3 hr treatment with Li+ than that in normal embryos at the post gastrula corresponidng stage. Augmentation of Na+, K+‐ATPase gene expression can be regarded as a marker for ectoderm cell differentiation at the post gastrula stage, which results from determination of cell fate in prehatching period.
Differential Expression of Retinoic Acid Receptor mRNA during Mouse Embryogenesis
Authors: Wu Tsung‐Chieh J. , Wang Lai , Wan Yu‐Jui Y.
Published: April 2005

Retinoic Acid, mediated through its receptors (RAR), exhibits striking effects on cell proliferation, differentiation, and pattern formation. At least three types of RARs (α, β, and γ) have been cloned. The ontogeny and semi‐quantitated amount of three RAR mRNA were studied in mouse embryos and placentas using reverse transcriptase‐polymerase chain reaction technique. The amplified cDNA products were confirmed by correct sizes, Southern blot hybridization and restriction enzyme digestion. The results show that RAR‐α mRNA is constitutively expressed in the oocytes and embryos of all stages, suggesting that RAR‐α is a housekeeping gene. RAR‐β mRNA is present in the oocytes, becomes undetectable at the 2‐cell stage when the maternal RNA is degraded, and re‐expresses at morula and blastocyst stages when the embryonic genome is activated. RAR‐γ mRNA is not expressed until balstocyst stage. In the postimplantation embryos, no significant change in all three RAR mRNA levels was detected from day 10 through the late gestational stage (day 18). Placental tissue expressed all three RAR transcripts throughout gestation. The differential activation of the these three RAR genes in the preimplantation embryos suggests RARs as the important regulators during early embryogenesis.
Induction of Cell Differentiation of Isolated Cells in Dictyostelium discoideum by Low Extracellular pH
Authors: Oohata Akiko A.
Published: April 2005

In Dictyostelium discoideum, the formation of multicellular masses is necessary for cell differentiation. However, the present study shows that amoebae of strain V12M2 efficiently differentiate to prespore or stalk cells under submerged incubation in a simple medium containing cAMP and salts without cell contact, only if the pH of the medium is maintained at acidic values; differentiation scarcely occurs in the neutral pH range. The optimum pH values for prespore and stalk cell differentiation are 5.1 and 4.5, respectively. In addition to the extracellular pH, Mg ions and the concentration of cAMP also affect the choice of the differentiation pathway. The time courses of differentiation of both cell types under optimum conditions are also presented.
Dynamic changes in developmental gene expression in the basal chordate Ciona intestinalis
Authors: Kawashima Takeshi , Satou Yutaka , Murakami Seiko D. , Satoh Nori
Published: April 2005

Large‐scale expressed sequence tags (EST) analysis was used to demonstrate a number of dynamic changes in the global gene expression profile of the basal chordate Ciona intestinalis over the course of its development. The fertilized egg was found to store a great variety of maternal transcripts and, as development proceeds, the organism expresses a progressively smaller repertoire of genes. In addition, a significant portion of genes involved in embryogenesis were observed to be downregulated during metamorphosis, at which point the adult appears to utilize a different set of genes to form its body. At least 25% of the genes involved in development were found to be used multiple times. This kind of information is essential to form a comprehensive understanding of the overarching expression‐control plan by which the basic chordate body is formed.
Multiple hypervascular liver nodules in a heavy drinker of alcohol
Authors: KIM SOO RYANG , MAEKAWA YOKO , NINOMIYA TOSHIAKI , IMOTO SUSUMU , MATSUOKA TOSHIYUKI , ANDO KENJI , MITA KEIJI , KU KWANSONG , KOTERAZAWA TOSHIHIRO , NAKAJIMA TAISUKE , FUKUDA KATSUMI , YANO YOSHIHIKO , NAKAJI MIYUKI , KUDO MASATOSHI , KIM KE IH , HIRAI MIDORI , HAYASHI YOSHITAKE
Published: April 2005

Abstract  A case of hypervascular nodules in the liver, but without hepatitis B or C virus infection in a 38‐year‐old woman with a history of alcohol abuse is presented. An ultrasound disclosed 1–2‐cm hypoechoic tumors in the right and left lobes. Magnetic resonance imaging showed high‐intensity tumors at both the T1‐weighted and T2‐weighted sequences. Incremental dynamic computed tomography and hepatic angiography revealed hypervascular tumors. Ultrasound‐guided needle biopsy revealed no evidence of hepatocellular carcinoma, metastatic liver cancer, hemangioendothelioma, inflammatory pseudotumors or pseudolymphoma, but demonstrated stellate‐scar fibrosis septa, which contained small unpaired arteries without hyperplasia dividing the nodule. Moreover, marked pericellular fibrosis, neutrophilic infiltration and Mallory bodies were observed in the cytoplasm. There was no evidence of bile duct proliferation. From these findings, the diagnosis of alcohol‐induced fibrosis, distinctly different from focal nodular hyperplasia, was tenable. Further studies may provide insights into the pathogenesis of nodule formation and hypervascularity in heavy drinkers of alcohol.
Causes of increased mortality from hepatocellular carcinoma in high incidence country: Taiwan experience
Authors: JAN CHYI‐FENG , CHEN CHIEN‐JEN , CHEN HSIU‐HSI
Published: April 2005

Background: Since 1991, a rapid rise in mortality from hepatocellular carcinoma (HCC) has been observed in Taiwan in subjects aged ≥20 years. The aim of the present study was to assess whether poor survival or excess incident cases pertaining to a cohort effect or a time‐period effect accounted for such a rise.

Methods: A total of 41 150 deaths and 51 201 incident HCC patients (International Classification of Diseases = 155.0) aged 20–79 years between 1985 and 1998 were studied. Trends in HCC mortality rates were divided into two groups: annual case‐fatality rates and HCC incidence rates by age. Poisson regression was used to distinguish a cohort effect from a time‐period effect on the incidence of HCC.

Results: Subjects aged >50 years after 1991 had the greatest risk of death (relative risk [RR] = 11.3; 95% confidence interval [CI]: 11.0–11.7). Annual case‐fatality rates declined from 1.6 in 1985 to 0.84 in 1998, whereas there was a remarkable increase in incidence, particularly from 1991 onward, in the >50‐year‐olds. It was found that subjects aged >50 years who were born before 1944 were the group most susceptible to HCC (RR = 9.3; 95%CI: 9.1–9.5).

Conclusion: Increased incidence, particularly in individuals over 50, rather than poor survival, accounts for the rapid rise in mortality from HCC.

© 2004 Blackwell Publishing Asia Pty Ltd
Association of fulminant non‐A non‐B hepatitis with homozygosity for HLA A1‐B8‐DR3
Authors: GOW PAUL , HATHAWAY MARK , GUNSON BRIDGET , HEWARD JOANNE , MUTIMER DAVID
Published: April 2005

Background:  For the majority of cases of acute liver failure in western Europe and North America an etiology cannot be defined. The condition is most often called fulminant non‐A, non‐B (NANB) hepatitis. Features such as female preponderance and presence of serum autoantibodies suggest a possible autoimmune basis. The aim of the present paper was to examine a possible human leukocyte antigen (HLA) association with fulminant NANB hepatitis.

Methods:  HLA A, B, and DR data of 55 adult Caucasian fulminant NANB patients were compared with those of 1449 local Caucasian controls.

Results:  In Caucasian patients, homozygosity (but not heterozygosity) for the alleles A1, B8, and DR3 were associated with fulminant NANB hepatitis (Pcorrected = 0.02, <0.00001 and 0.002, respectively). Greatest relative risk (RR) was associated with homozygosity for the A1‐B8‐DR3 haplotype (P < 0.00001; RR: 12.8; 95% confidence interval [CI]: 5.7–22.3). HLA DR8 was also associated with development of the syndrome (RR: 4.2; 95%CI: 1.6–9.2).

Conclusions:  Homozygosity for the HLA haplotype A1‐B8‐DR3 confers susceptibility to the development of fulminant NANB hepatitis. This observation may imply a role for the immune response genes (which are flanked by HLA B and DR) in the pathogenesis of this syndrome.
Clonality analysis of multiple hepatocellular carcinomas by loss of heterozygosity pattern determined by chromosomes 16q and 13q
Authors: LIN YA‐WEN , LEE HSUAN‐SHU , CHEN CHIEN‐HUNG , HUANG GUAN‐TARN , LEE PO‐HUANG , SHEU JIN‐CHUAN
Published: April 2005

Background and Aim: Loss of heterozygosity (LOH) on chromosomes 16q and 13q, associated with tumor development, is frequently found in hepatocellular carcinoma (HCC). In light of this, an attempt was made to use the LOH pattern determined by microsatellite markers on 16q and 13q to discriminate clonality.

Methods: In an effort to locate the LOH region more precisely and select the appropriate markers, LOH studies on 88 HCC using a panel of 35 microsatellite markers on 16q were carried out. Nine independent regions of frequent LOH were defined. In combination with a previous study of deletion mapping of 13q by the same authors, 12 markers on 16q and 13q were selected and polymerase chain reaction amplification, from microdissection‐extracted DNA, was used to allelotype microsatellite polymorphism as an indication of clonality.

Results: Two patterns of LOH were observed. In pattern A, in 8 of 16 (50%) patients, the LOH pattern of the first tumor was preserved in the second sample, with some tumors also showing additional LOH. In these patients, the original and second tumors are presumed to arise from the same original clone with or without progressive accumulation of LOH. In pattern B (8 of 16, 50%), LOH seen in the first tumor was not preserved in the second or recurrent tumors, as evidenced by retention of heterozygosity compared with the first tumor.

Conclusion: The data suggest that the second tumor might have arisen from another independent clone. Moreover, this approach also provides a more sensitive and specific strategy to determine whether multiple or recurrent tumors are derived from the same or a different clone.
Changing trends in peptic ulcer prevalence in a tertiary care setting in the Philippines: A seven‐year study
Authors: WONG STEPHEN N , SOLLANO JOSE D , CHAN MELCHOR M , CARPIO RAMON E , TADY CELINA S , ISMAEL ALBERT E , JUDAN‐RUIZ ESTELITA A , ANG VICTORIO N , GO JOHNNY T , LIM VICTORIANO Y , PEREZ JESUS Y , ALVAREZ SOL Z
Published: April 2005

Background and Aims:  The declining global prevalence of peptic ulcer disease (PUD) might be because of the decreasing prevalence of Helicobacter pylori (Hp) infection. The aims of the present study were to determine the prevalence of PUD during a 7‐year period and to investigate its relationship with the prevalence of Hp infection during the same period.

Methods:  All upper gastrointestinal endoscopies carried out at Santo Tomas Hospital in Manila from January 1996 to December 2002 were evaluated. Endoscopies reporting gastric ulcers (GU) and duodenal ulcers (DU) with Hp status were analyzed.

Results:  A total of 15 341 endoscopies were evaluated. Overall, 2600 (16.95%) GU and 1575 (10.27%) DU were identified. There was a decreasing trend in the prevalence of GU (P < 0.0001) and DU (P < 0.0001) during the study period. Overall PUD prevalence declined from 35.87% in 1996 to 18.80% in 2002. This decline was seen for both GU and DU (20.05 vs 14.34%, and 15.83 vs 7.02%, respectively). The prevalence of Hp infection decreased significantly from 1996 to 2002 for both GU and DU (68.13 vs 33.48%, P < 0.0001; and 76.67 vs 36.50%, P < 0.0001, respectively). The decrease in Hp prevalence was significantly related to the decrease in ulcer prevalence (r = 0.97, P = 0.0004 for GU; r = 0.89, P = 0.0079 for DU; and r = 0.92, P = 0.0035 for all PUD). The prevalence of bleeding secondary to PUD remained stable during the 7‐year period (P = 0.87).

Conclusions:  During the 7‐year period, there was a significant decline in the prevalence of PUD. This decline in PUD prevalence was associated with a corresponding decrease in Hp prevalence.
Symptomatic portal system thrombosis in soldiers due to extended stay at extreme altitude
Authors: ANAND ANIL C , SAHA ANUPAM , SETH AVNISH K , CHOPRA GURVINDER S , NAIR VELU , SHARMA VIVEK
Published: April 2005

Background:  With induction of Indian Army to heights over 5000 m above mean sealevel (MSL), several new complications of long‐term stay at extreme altitude have come to light. The authors’ experience with soldiers who developed symptomatic portal system thrombosis (SPST) is described here.

Methods:  Clinical data were prospectively collected between April 1998 and April 2003, on all patients hospitalized for SPST from high‐altitude areas (HAA, >3000 m above MSL) and those from non‐high‐altitude areas (NHAA). Site of thrombosis was confirmed by imaging and included splenic, portal, superior mesenteric, or inferior mesenteric vein thrombosis. Patients were investigated to rule out known predisposing factors and prothrombotic conditions.

Results:  A total of 37 cases of SPST were seen during the study period, of which 26 were from HAA. Mean age of cases from HAA was 27 ± 4.6 years and all were male. Mean stay at high altitude was 11.7 ± 6.2 months. First symptom was pain in abdomen in almost all the cases, later followed by gastrointestinal bleeding and fever in 14 each, and vomiting in 19. Clinical examination showed ascites (81%), splenomegaly (76.9%), and hepatomegaly (69.2%). Diagnosis was made by imaging scans (23 cases) and on surgery in three cases. A known prothrombotic state was detected in five cases from HAA and in eight cases from NHAA (P ≤ 0.01). Ultrasound Doppler scan picked up collaterals as early as 12–45 days after onset of symptoms.

Conclusions:  Extended stay at HAA may be a risk factor for development of symptomatic portal system thrombosis.
Altered expression of vascular endothelial growth factor, fibroblast growth factor‐2 and endostatin in patients with hepatocellular carcinoma
Authors: UEMATSU SHUJI , HIGASHI TOSHIHIRO , NOUSO KAZUHIRO , KARIYAMA KAZUYA , NAKAMURA SHIN‐ICHIRO , SUZUKI MAYUMI , NAKATSUKASA HARUSHIGE , KOBAYASHI YOSHIYUKI , HANAFUSA TADASHI , TSUJI TAKAO , SHIRATORI YASUSHI
Published: April 2005

Background: Advanced hepatocellular carcinoma (HCC) in humans is characterized by hypervascularity. In the present study, the expressions of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF‐2) and endostatin were analyzed in patients with chronic liver disease to clarify the effect of these major angiogenic factors.

Methods: Serum concentrations of VEGF, FGF‐2 and endostatin in 24 patients with HCC, 16 patients with liver cirrhosis (LC) and 13 healthy volunteers were measured by enzyme‐linked immunosorbent assay. The expression of VEGF in 21 surgically resected HCC samples was analyzed by immunohistochemistry, and that of VEGF isoforms in 15 HCC samples was assessed by reverse transcriptase–polymerase chain reaction (RT‐PCR).

Results: Serum VEGF, FGF‐2 and endostatin concentrations were significantly elevated in patients with HCC compared with healthy volunteers; but there was no significant difference between patients with HCC and those with non‐HCC liver disease. Immunohistochemical analysis showed that VEGF protein was strongly expressed in both well‐differentiated HCC cells and non‐cancerous hepatocytes, whereas in moderately and poorly differentiated HCC the expression was stronger in the endothelial cells (EC) lining intratumor vessels than in the cancer cells. On RT‐PCR for VEGF isoforms it was found that VEGF‐121, VEGF‐165 and VEGF‐189 were expressed in all but one of the HCC samples and in all corresponding non‐HCC samples.

Conclusions: The results suggest that VEGF, FGF‐2, and endostatin concentrations are elevated prior to the emergence of HCC and that the distribution of VEGF changes dynamically during the development of HCC.
Evaluation of predictive value of CLIP, Okuda, TNM and JIS staging systems for hepatocellular carcinoma patients undergoing surgery
Authors: HUANG YI‐HSIANG , CHEN CHIEN‐HUNG , CHANG TING‐TSUNG , CHEN SHINN‐CHERNG , WANG SHEN‐YUNG , LEE HSUAN‐SHU , LIN PIN‐WEN , HUANG GUAN‐TARN , SHEU JIN‐CHUAN , TSAI HONG‐MING , LEE PUI‐CHING , CHAU GAR‐YANG , LUI WING‐YIU , LEE SHOU‐DONG , WU JAW‐CHING
Published: April 2005

Background: An accurate staging system is required to assess hepatocellular carcinoma (HCC) patients in order to benefit from hepatic resection before surgery. Cancer of the Liver Italian Program (CLIP) score was considered to be better than the Okuda staging system to predict survival. Japan Integrated Staging Score (JIS score) includes tumor, nodes, metastases (TNM) stage and Child–Pugh grade as a new staging system for HCC. The purpose of the present paper was to compare the CLIP, Okuda, TNM and JIS staging systems for HCC patients undergoing surgery.

Methods: From 1991 to 1995, 599 patients undergoing hepatic resection for HCC from four medical centers in Taiwan were evaluated. All patients were classified by Okuda, CLIP, TNM and JIS systems. Factors associated survivals were analyzed.

Results: There was no statistical difference in survival between CLIP 0 and 1 patients, or among CLIP 2–4 patients. The prognostic validation of the Okuda and CLIP scoring systems in discriminating survival in HCC patients undergoing surgery was not satisfied. The TNM system was successful in predicting survival for HCC patients undergoing surgery. The JIS score could also differentiate survivals for those patients except for JIS 3. By multivariate analysis, age ≥60 years old, serum albumin <3.5 g/dL, tumor size >5 cm and TNM stage were associated with survival.

Conclusion: Both the Okuda and CLIP systems are not superior to TNM staging for HCC patients who undergo surgical resection. Whether JIS score is feasible for those patients with advanced HCC needs further evaluation.
Liver histopathology in human immunodeficiency virus–hepatitis C virus co‐infected patients with fatal liver disease
Authors: LICHTERFELD MATHIAS , HAAS SUSANNE , FISCHER HANS‐PETER , VOIGT ESTER , ROCKSTROH JÜRGEN K , SPENGLER ULRICH
Published: April 2005

Background:  Liver failure is an increasing cause of death in human immunodeficiency virus–hepatitis C virus (HIV–HCV) co‐infected patients. Here, histopathological features of fatal liver disease in HIV–HCV co‐infected patients were comparatively assessed.

Methods:  Liver biopsies of seven HIV–HCV co‐infected patients with clinically imminent liver death and advanced immune deficiency were studied. Biopsies of seven asymptomatic patients with stable hepatic and immune functions, who were matched according to their documented duration of HIV–HCV co‐infection, served as controls. Inflammatory and fibrotic changes as well as hepatocellular steatosis and cholestasis were assessed semiquantitatively by established scores.

Results:  All patients with fatal liver disease had severe immunodeficiency and jaundice, while biliary ducts were patent. Unexpectedly, the extent of hepatic steatosis, inflammatory activity and fibrosis was strikingly similar in both study groups. Importantly, liver failure was observed even in the absence of marked fibrosis. Lobular bilirubinostasis was the only feature that significantly distinguished patients with advanced immunodeficiency and fatal liver disease from the control group.

Conclusion:  Thus, rapid deterioration of liver function and death can occur in HIV–HCV co‐infected patients with advanced immunodeficiency even when liver histology does not reveal markers of end‐stage liver disease. Jaundice and marked bilirubinostasis in the absence of biliary tract obstruction seem to herald this complication of chronic hepatitis C in HIV infection.
Impaired capsaicin and neurokinin‐evoked colonic motility in inflammatory bowel disease
Authors: SMITH ALICIA S , SMID SCOTT D
Published: April 2005

Background:  Inflammatory bowel disease (IBD) is associated with altered sensory and motor function in the human colon. The aim of the present study was to compare neuromuscular function in normal and IBD‐affected colon in vitro, with emphasis on inhibitory enteric nerves, sensory neuropeptides and stimulation of axon collaterals.

Methods:  Strips of longitudinal and circular muscle were prepared following colectomy from six patients with intestinal carcinoma (mean age 64.2 ± 4.8 years) and six patients with IBD (Crohn's disease, n = 3; ulcerative colitis, n = 3: mean age 35.8 ± 5.7 years). Responses were measured to electrical field stimulation, potassium chloride, 1,1‐dimethyl‐4‐phenylpiperazinium iodide, isoprenaline, calcitonin gene‐related peptide (CGRP), capsaicin and neurokinin (NK)‐1 and ‐2 receptor subtype‐specific agonists, alone or after muscle precontraction.

Results:  The NK‐1 and CGRP receptor‐mediated relaxation was reduced in the circular (by 44%, P < 0.05) and longitudinal (by 61%, P < 0.05) muscle from IBD‐affected colon, respectively. Maximal NK‐2 receptor‐mediated contraction was also significantly decreased in both longitudinal (71%, P < 0.001) and circular (51%, P < 0.01) muscle. Capsaicin evoked relaxation in precontracted colonic longitudinal and circular muscle; this was significantly diminished in the IBD‐affected colon (by 63%, P < 0.001 and 76%, P < 0.01, respectively). Responses evoked by stimulation of enteric inhibitory nerves were not significantly altered.

Conclusions:  Colonic muscle strips from patients with IBD exhibited impaired CGRP and NK‐1 receptor‐mediated relaxation and NK‐2 receptor‐mediated contraction. Capsaicin‐activated relaxation of colonic smooth muscle is deficient in IBD‐affected colon. These results suggest a discrete effect of IBD on sensory‐motor coupling and tachykinin‐mediated effects on colonic motility.
Antiviral therapy in advanced chronic liver disease due to hepatitis C virus infection: Pilot study
Authors: KUMAR RAKESH , KUMAR SUDHEER , SHARMA BARJESH CHANDER , SINGH JAGDEEP , SARIN SHIV K
Published: April 2005

Background:  Antiviral therapy has not been adequately evaluated in patients with hepatitis C virus (HCV)‐related advanced liver disease due to apprehensions of adverse events and intolerance. The titrable dose of interferon (IFN)‐α and ribavirin was evaluated in a flexible regimen in a pilot study.

Methods:  Twenty‐five patients with HCV‐related advanced chronic liver disease received IFN‐α 1–3 MIU daily with ribavirin 200–600 mg daily for 9 months−3 years. Careful assessment of safety, tolerability and efficacy was made.

Results:  Improvement in Child–Pugh score (8.4 ± 1.2 to 7.4 ± 2.0; P = 0.010) and serum albumin (3.0 ± 0.5 g/dL to 3.6 ± 0.5 g/dL; P = 0.007) occurred at follow up after antiviral therapy (median dose and duration: IFN‐α 1.5 MIU/day for 12 months and ribavirin 400 mg/day for 7.5 months) as compared to baseline. Ascites regressed in 53% of patients (11/21). Thirteen patients (52%) lost HCV‐RNA on therapy and eight (32%) achieved sustained virological response (SVR). Death occurred in three patients (12%) while on therapy, in two due to infection. No patient died in the responder group compared to five deaths (29%) in the non‐responder group. However, there was no difference in the cumulative probability of survival in the sustained virological responder versus non‐responder (P = 0.09). Adverse events were common (92%), but permanent withdrawal was required in only five patients (20%).

Conclusions:  Low and titrable dose IFN‐α and ribavirin therapy in patients with HCV‐related advanced chronic liver disease achieves improvement in hepatic synthetic function, Child–Pugh score and ascites. However, close monitoring for serious adverse events is warranted.
Push enteroscopy alters management in a majority of patients with obscure gastrointestinal bleeding
Authors: NGUYEN NAM Q , RAYNER CHRISTOPHER K , SCHOEMAN MARK N
Published: April 2005

Introduction:  Although enteroscopy has been increasingly used to investigate occult or obscure bleeding, little is known about its impact on patient management. The aim of the present paper was to evaluate both the diagnostic yield and the impact of push enteroscopy on the management of patients referred to a tertiary Australian institution.

Methods:  Data were collected prospectively in all patients undergoing push enteroscopy at Royal Adelaide Hospital. Fifty‐five patients were investigated for obscure gastrointestinal (GI) bleeding (25 women, mean age 65.6 years), the cause of which remained unknown despite previous gastroscopy and colonoscopy. The patients were divided into two groups: occult‐obscure (anemia without macroscopic blood loss) and overt‐obscure (macroscopic bleeding). Findings at enteroscopy, therapeutic procedures, and complications were recorded. Patients were followed to establish the impact of the procedure on subsequent management and clinical outcome.

Results:  Enteroscopy demonstrated a potential site of bleeding in 38 patients (69%), and 38% of lesions found were within the reach of the gastroscope. The most common lesions were small intestinal angiodysplasia. Seventy‐five percent of patients with positive findings had alterations to their management. After subsequent treatment, 62% were no longer anemic and there was a significant reduction in rebleeding (P < 0.05) and transfusion requirements (P < 0.05) compared to patients with negative findings. The procedure was well tolerated and complications were rare.

Conclusion:  Enteroscopy has a positive impact on patient management and clinical outcome in a majority of patients with obscure gastrointestinal bleeding.