bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerosolized pentamidine prophylaxis for Pneumocystis carinii pneumonia after allogeneic marrow transplantation
Authors: Marras T.K. , Sanders K. , Lipton J.H. , Messner H.A. , Conly J. , Chan C.K. , Marras T.K. , Sanders K. , Lipton J.H. , Messner H.A. , Conly J. , Chan C.K.
Published: March 2003

Pneumocystis carinii pneumonia (PCP) poses a serious risk to allogeneic bone marrow transplant (BMT) patients, who are often intolerant of trimethoprim‐sulfamethoxazole (TMP‐SMX), the traditional first‐line prophylactic agents. There are limited published data supporting the use of aerosolized pentamidine (AP) prophylaxis in the BMT population. We assessed the effectiveness of AP in BMT recipients by reviewing the experience at our center. We divided our review into four time periods from January 1990 to March 2000, during which approximately 700 BMTs were performed. The first period includes patients receiving AP treatments from January 1990 to July 1997 (baseline), the second from August 1997 to July 1998 (pre‐outbreak), the third from August 1998 to October 1999 (outbreak), and the fourth from November 1999 to March 2000 (post‐outbreak). At our center, TMP‐SMX is the first‐line agent for PCP prophylaxis, which is routinely continued for at least one year, or for the duration of enhanced immunosuppression. During the baseline period, 505 BMTs were performed and 192 patients (38%) received AP for part of their time at risk. Six patients (3%) experienced toxicities requiring discontinuation of AP. Three cases of PCP were diagnosed over 1114 patient‐months of treatment in the baseline period. During the last 42 months of the baseline period, 2/154 patients receiving AP and 2 of an estimated 293 patients receiving exclusively oral prophylaxis developed breakthrough PCP (p = 0.61). During the outbreak period, 9 of 180 patients receiving AP developed PCP compared to none in the group receiving exclusively oral prophylaxis. Either changes in our AP protocol during the pre‐outbreak period or pentamidine resistance may have led to this failure of prophylaxis. There were no further cases during the 5‐month post‐outbreak period. Our observed overall breakthrough rate was 12 cases out of 439 patients (2.7%). Our study shows that AP is an effective and well‐tolerated second‐line agent in preventing PCP post BMT and we recommend its continued use in this regard. However, it should be administered using a well‐studied protocol, and only when TMP‐SMX is not tolerated.
Growth of porcine kidneys in their native and xenograft environment
Authors: Soin Bob , Ostlie Daniel , Cozzi Emanuele , Smith Kenneth G. C. , Bradley John R. , Vial Conrad , Masroor Saqib , Lancaster Richard , White David J. , Friend Peter J.
Published: March 2003

Abstract: The increased survival of hDAF pig‐to‐primate renal xenografts for up to two months has afforded the opportunity to study physiological aspects such as organ growth. Experimental evidence exists of species restriction of the activity of growth hormone, although growth itself is also controlled by a number of other endocrine, paracrine and autocrine substances.

This study consisted of four parts: (1) measurement of pig kidney size according to pig body weight; (2) measurement of pig kidney size according to pig age; (3) serial length measurement of pig‐to‐primate renal xenografts; (4) correlation of terminal weight of renal xenograft with age and histology.

The xenografted pig kidneys in a primate recipient grow as they would in the pig for the first two weeks after transplantation. After this time there is a reduction in the rate of increase in the length of the xenograft. Over the same period, changes in weight are greatly increased by the presence of rejection. This observational study supports the notion that regulation of growth of a xenotransplanted porcine kidney occurs.
Concordant xenotransplantation –non‐vascularized pancreatic islets are more difficult to regraft than the vascularized heart
Authors: Bersztel Adam , Andersson Arne , Björkland Anna , Tufveson Gunnar , Johnsson Cecilia
Published: March 2003

Abstract: We have previously demonstrated that it is possible to perform retransplantation of a xenogeneic heart (mouse‐to‐rat) using cyclosporine A as monotherapy, provided that the first heart is transplanted under a short course of deoxyspergualin (DSG). If DSG is omitted, the first heart is rejected within four days and the second heart succumbs to hyperacute rejection within minutes. A mouse heart as first graft does not protect a consecutive pancreatic islet graft, although the heart continues to function after rejection of the cellular graft. One explanation for this discrepancy may be the fact that cellular grafts, as pancreatic islets, lack an endothelial lining. We have, therefore, further investigated possible differences between vascularized and non‐vascularized xenografts regarding their capacity to induce unresponsiveness.

The use of pancreatic islets as primary graft neither accelerated nor decelerated the speed of rejection of the vascularized heart used as secondary graft. Furthermore, hemagglutinating and cytotoxic antibody titres responded in the same manner as in naive rats transplanted with a mouse heart. Retransplantation with pancreatic islets also resulted in complete rejection of both the primary and secondary grafts. Thus, the lack of unresponsiveness cannot simply be explained by differences, between the pancreatic and cardiac tissues, in antigen expression. In addition, intraperitoneal transplantation of mouse heart cells as primary graft resulted in rejection of a secondary cardiac graft after three days. However, it cannot be totally excluded that the time of antigen exposure had an impact on these results.

In conclusion, our previous and present studies suggest that the presence of an intact vascular bed, both in the first and second graft, is necessary to create a state of unresponsiveness. Because the pancreatic islets lack an endothelial lining, they do not benefit from an unresponsiveness of the immune system. Neither are they able to induce such an unresponsiveness.
Delayed rejection of fetal pig pancreas in CD4 cell deficient mice was correlated with residual helper activity
Authors: Zhan Yifan , Kelly Alexandra J. , Brady Jamie L. , Sutherland Robyn M. , Lew Andrew M.
Published: March 2003

Abstract: CD4 cells have been shown to play a dominant role in the rejection of xenografts. Depletion of murine CD4 cells by injecting anti‐CD4 antibody prolongs the graft survival, but does not prevent its rejection. For a more stable phenotype, we used genetically modified mice. To test whether the delayed rejection is caused by incomplete depletion of CD4 cells, we evaluated the response to fetal pig pancreas (FPP) xenografts in three types of CD4 cell deficient mice. They are MHC class II deficient mice (MHC II°/°), CD4 deficient mice (CD4°/°) and a novel type of CD4 cell deficient mice (designated GK). GK mice were rendered permanently and completely CD4 deficient by transgenic expression of anti‐CD4 antibody, whereas both MHC II°/° and CD4°/° mice have a residual helper cell population. FPP grafts in wild type mice were rejected within a week, whereas FPP grafts survived up to 4 weeks in MHC II°/° and CD4°/° mice. Survival of grafts in GK mice was even longer (8 weeks). Differences in histology were also noted. Rejecting grafts in MHC II°/° and wild‐type mice were infiltrated with both eosinophils and mononuclear cells, whereas the infiltrates in CD4°/° and GK mice were exclusively mononuclear cells. Immuno‐histochemistry showed that they were primarily CD8 cells. The immune response to FPP was clearly different in the three types of CD4 cell deficient mice. Splenocytes of MHC II°/° 3 weeks post‐transplant with FPP produced substantial amounts of IFN‐γ and IL‐5, whereas splenocytes of CD4 °/° mice produced low levels of IFN‐γ but no detectable IL‐5. At similar times, these cytokines were not detected in GK mice. Furthermore, CD4°/° mice were capable of mounting helper dependent, although reduced, IgG responses to FPP antigens, while GK mice were not. The above results indicate that residual helper activity in some types of CD4 cell deficient mice could still contribute to xenograft rejection. Caution needs to be exercised where such mice are used as models of CD4 cell deficiency. Also, because there is eventual rejection of xenograft FPP in GK mice which lack detectable helper activity, we argue that these mice are a better model to investigate the involvement of CD4‐independent rejection mechanisms.
Contrast in the efficacy of hDAF mouse hearts between ex vivo perfusion and transplantation into primates
Authors: Verbakel Caroline A. E. , De Bruin Ron W. F. , Bonthuis Fred , Jonker Margreet , Dekker Sylvia , Marquet Richard L. , IJzermans Jan N. M.
Published: March 2003

Abstract: In recent experiments, in which we compared hDAF transgenic rat hearts perfused with 15% human serum in the Langendorff device and hDAF rat hearts transplanted into cynomolgus monkeys, we demonstrated that in the ex vivo heart perfusion model both homozygous and heterozygous hDAF hearts survived longer as nontransgenic controls. Surprisingly, we found that only homozygous hDAF hearts were protected against hyperacute rejection in vivo. The first aim of this study was to determine whether perfusion of mouse hearts with higher human serum concentrations or human blood might explain some of the differences found in survival time of the recently performed experiments with rat heart xenografts. Secondly, we investigated whether the observed differences in survival times of rat xenografts between in vivo and ex vivo transplantation would also hold for mouse hearts transgenic for hDAF. An ex vivo model was used to perfuse hDAF mouse hearts and controls with human serum or blood, and hDAF transgenic hearts and controls were transplanted into cynomolgus monkeys. hDAF transgenic mouse hearts survived significantly longer than their controls when perfused with 15% human serum, but no difference was found when 30% human serum was used, or when these hearts were transplanted into cynomolgus monkeys. However, in both the in vivo and ex vivo models the amount of PMNs adhering to the vascular endothelium was significantly lower in hDAF transgenes as compared with their controls. In conclusion, in the ex vivo situation, the efficacy of hDAF transgenesis in preventing HAR is limited by serum complement concentration.
Maturation of xenoantibody gene expression during the humoral immune response of rats to hamster xenografts
Authors: Wu Gordon D. , Gochi Eiji , Jin Yang‐Sun , Swensson Joyce , Starnes Vaughn A. , Cramer Donald V.
Published: March 2003

Abstract: Immunoglobulin isotype switching represents an important component of antibody maturation in the development of humoral immune responses. We have recently conducted a series of studies in a nonimmunosuppressed rodent model to define the kinetics of xenoantibody production and seek evidence for the maturation of xenoantibody Ig gene expression by xenograft recipients. LEW rats were transplanted with hamster cardiac xenografts and the grafts were allowed to remain in situ for prolonged immune stimulation of the host. Anti‐hamster antibodies were examined at days 4, 8, 21, 28 and 40 post‐transplantation. cDNA libraries specific for rat µ or γ heavy chains were constructed from B lymphocytes of the xenograft recipients at day 4 and day 21 post‐transplantation. Selected cDNA clones encoding the Ig VHHAR family of genes from each group were sequenced and analyzed for the presence of somatic mutations. We found that the reactivity of xenoantibodies examined with flow cytometry underwent sequential changes in which IgM titers peaked at day 8 post‐transplantation (PTx) and returned to low levels after 21 days. IgG titers started to increase at about one week PTx and peaked at 21–28 days. All the IgG isotypes (IgG1, 2a, 2b and 2c) were differentially involved in the IgG responses. Serum passive transfer experiments demonstrated that IgM antibody fractions separated from sera at day 4 post‐transplantation were capable of causing hyperacute rejection (HAR) of hamster xenografts, whereas IgM fractions from days 21–40 failed to cause HAR (N = 7, MST = 4 days), a pattern that was consistent with a rise in total xenoreactive IgM levels at days 4–8 and a fall to low levels at 21 days post‐transplantation. IgG‐containing fractions separated from day 21–40 antisera caused HAR (N = 7, MST = 36 min) whereas IgG fractions from day 8 sera failed to induce graft rejection. Genetic analysis of the rearranged VH genes from 10 cDNA clones demonstrated that the Ig µ (n = 5) and γ (n = 5) chain clones used the same family of VH genes (VHHAR family) to encode their antibody binding activity. The majority (80%) of the IgM clones were present in their original germline configuration. In contrast, the nucleotide sequences from IgG clones manifested an increase in the numbers of replacement mutations in the CDR region of the Ig heavy chain genes, providing evidence for a potential role for somatic mutation in the maturation of IgG xenoantibody responses as the humoral response matures with time post‐transplantation.
The production of transgenic pigs for potential use in clinical xenotransplantation: baseline clinical pathology and organ size studies
Authors: Tucker Alexander , Belcher Carolyn , Moloo Badru , Bell Judith , Mazzulli Tony , Humar Atul , Hughes Allison , McArdle Peter , Talbot Antony
Published: March 2003

This report describes the results of hematology, serum biochemistry, growth, and organ weight studies undertaken on pigs from nine cohorts of qualified pathogen free (QPF) pigs reared within a high welfare bioexclusion facility as potential organ source animals. Confirmation of the high health status of the pigs was given through total leukocyte counts and serum globulin concentrations that fell below the expected reference range for conventional pigs. The calculated mean growth rate for QPF pigs was found to exceed target rates set for optimum genotype commercial pig herds. Body weights of QPF pigs were compared with kidney, heart and liver weights at necropsy.
Sex allocation in the sexually monomorphic fairy martin
Authors: Magrath Michael J. L. , Green David J. , Komdeur Jan
Published: March 2003

Offspring sex ratios were examined at the population and family level in the sexually monomorphic, socially monogamous fairy martin Petrochelidon ariel at five colony sites over a 4‐year period (1993–1996). The sex of 465 nestlings from 169 broods was determined using sex‐specific PCR at the CHD locus. In accordance with predicted sex allocation patterns, population sex ratios at hatching and fledging did not differ from parity in any year and the variance in brood sex ratios did not deviate from the binomial distribution. Further, brood sex ratio did not vary with hatching date during the season, brood number, brood size or colony size. The sex ratio of broods with extra‐pair young did not differ from those without, while the sex ratio of broods fathered by males that gained extra‐pair fertilizations did not differ from broods fathered by other males. Extra‐pair chicks were as likely to be male as female. Neither the total number of feeding visits to the brood nor the relative feeding contribution by the sexes varied significantly with brood sex ratio. Brood sex ratios were also unrelated to paternal size, condition and breeding experience or maternal condition and breeding experience. However, contrary to our prediction, brood sex ratio was negatively correlated with maternal size. Generally, these results were consistent with our expectations that brood sex ratios would not vary with environmental factors or parental characteristics, and would not influence the level of parental provisioning. However, the finding that females with longer tarsi produced an excess of daughters is difficult to reconcile with our current understanding of fairy martin life history and breeding ecology.
Predictors of natal dispersal in great reed warblers: results from small and large census areas
Authors: Hansson Bengt , Bensch Staffan , Hasselquist Dennis
Published: March 2003

For most species, it is currently not known whether individual characteristics and population parameters affecting dispersal distances within the local population are also affecting dispersal of individuals emigrating longer distances. We evaluated this in the great reed warbler Acrocephalus arundinaceus by analysing data of natal dispersal distances within (1) the local hatching area in southern Central Sweden and (2) the species’ whole breeding range in Sweden. The different scales gave conflicting results. Site of birth was the main predictor of natal dispersal distance in the local census area, whereas in the larger census area the dispersal distance differed significantly between hatching years. Previous studies have shown that the recruitment rate of great reed warblers within the local study area differs between hatching years and also that it declines during the course of the breeding season. It was not known, however, whether these relationships reflected variation in survival or dispersal. The results from the present study suggest that the differences in local recruitment rate between hatching years is partly caused by annual variation in emigration rate, whereas the decline in local recruitment rate with season mainly reflects mortality of late‐hatched nestlings. Our study shows a twofold advantage of a large census area when studying dispersal. First, predictors of longer‐distance dispersal will be revealed and, second, the variation in local recruitment rate can be separated into the two components, survival and dispersal.
Structure and flexibility of the multiple domain proteins that regulate complement activation
Authors: Kirkitadze Marina D. , Barlow Paul N.
Published: March 2003

In this review we summarise more than 10 years of biophysical exploration into the structural biology of the regulators of complement activation (RCA). The five human proteins responsible for regulation of the early events of complement are homologous and are composed largely from building blocks called “complement control protein (CCP) modules”. Unlike most multiple domain proteins they do not contain any of the other widely occurring module types. This apparent simplicity of RCA structure, however, is belied by their sophistication of function. In fact, the structures of the individual CCP modules exhibit wide variations on a common theme while the extent and nature of intermodular connections is diverse. Some neighbouring modules within a protein stabilise each other and some co‐operate to form specific binding surfaces. The degree of true “modularity” of CCPs is open to debate. The study of RCA proteins clearly illustrates the value of combining complementary structural biology techniques. The results could have implications for folding, evolution, flexibility and structure–function relationships of other molecules in the large, diverse and little understood category of multiple domain proteins.

Work in the Barlow laboratory was supported by the Medical Research Council and the Biotechnology and Biological Sciences Research Council of the UK and by the Wellcome Trust. MDK was supported by the Human Frontiers Science Program.
The ever‐expanding Ly49 gene family: repertoire and signaling
Authors: Anderson Stephen K. , Ortaldo John R. , McVicar Daniel W.
Published: March 2003

Summary: The mouse lectin‐related Ly49 family and the human killer cell Ig‐like receptor (KIR) family represent structurally distinct, yet functionally analogous, class I MHC receptors that are expressed on natural killer cells and some T cells. The functional similarity of these two families has been borne out by the demonstration of identical signal transduction pathways associated with each receptor family. The Ly49 family therefore provides a useful model system to study the role of this class of receptors in the regulation of the immune system. Recent data relating to the Ly49 repertoire in several mouse strains has revealed an additional evolutionary parallel between KIR and Ly49 receptor families. There is now an appreciation of the variation in the number and type of Ly49s expressed in different mouse strains, similar to the previously demonstrated differences in the number of KIR genes found in humans. This review summarizes the current members of the Ly49 gene family, their MHC class I recognition and associated signal transduction pathways.

This work was supported in part through NCI contract No. NO1‐CO‐56000.
Murine natural killer cell activation receptors
Authors: Smith Hamish R. C. , Idris Azza H. , Yokoyama Wayne M.
Published: March 2003

Summary: Natural killer (NK) cells express two types of receptors involved in target recognition: inhibitory receptors for target cell MHC class I molecules and activation receptors. While there has been significant progress in understanding the inhibitory receptors, less is known about the activation receptors. Detailed analysis of several mouse NK‐cell activation receptors provides insight into the physiologic relevance of these receptors in the innate immune response.

We gratefully acknowledge past and present members of our laboratory for their work on NK‐cell receptors and particularly Hubert Chuang for his recent efforts on Qa‐1 receptors mentioned in this manuscript. Work in the Yokoyama laboratory is supported by grants from the National Institutes of Health. H.R.C.S. is supported by a training grant from NIH. W.M.Y. is an investigator of the Howard Hughes Medical Institute.
Heteropolymer‐mediated clearance of immune complexes via erythrocyte CR1: mechanisms and applications
Authors: Lindorfer Margaret A. , Hahn Chang S. , Foley Patricia L. , Taylor Ronald P.
Published: March 2003

Summary: Opsonization of particulate pathogens by antibodies and complement can lead to their binding to the complement receptor (CR1), specific for C3b, on primate erythrocytes (E). This process of immune adherence may play a role in immunologic defense by immobilizing bacteria and viruses, thus preventing them from leaving the bloodstream to invade susceptible tissue and organs. Immune adherence of C3b‐opsonized and immune complexed pathogens to E may also facilitate their transfer to, and destruction by, fixed tissue macrophages. We have used mAbs specific for CR1 crosslinked with pathogen specific mAbs to generate heteropolymers (HP) which can bind a wide range of substrates to primate erythrocytes. Both prototype and bonafide pathogens bound to primate E via HP are handled in the circulation of non‐human primates in a manner which appears to be virtually identical to the mechanism by which C3b‐opsonized substrates bound to E CR1 are cleared. In this process of focused phagocytosis, Fc receptors on the phagocytic cell engage the E‐bound complex, CR1 is removed by proteolysis, and the entire immune complex and CR1 are internalized while sparing the E. It may be possible to use HP to target pathogens in the bloodstream in a wide range of therapeutic applications.
Primary immunodeficiency diseases: dissectors of the immune system
Authors: Buckley Rebecca H.
Published: March 2003

Summary: The past 50 years have seen enormous progress in this field. An unknown concept until 1952, there are now more than 100 different primary immunodeficiency syndromes in the world's literature. Each novel syndrome has shed new insight into the workings of the immune system, dissecting its multiple parts into unique functioning components. This has been especially true over the past decade, as the molecular bases of approximately 40 of these diseases have been identified in rapid succession. Advances in the treatment of these diseases have also been impressive. Antibody replacement has been improved greatly by the development of human immunoglobulin preparations that can be safely administered by the intravenous route, and cytokine and humanized anticytokine therapies are now possible through recombinant technologies. The ability to achieve life‐saving immune reconstitution of patients with lethal severe combined immunodeficiency by administering rigorously T‐cell‐depleted allogeneic related haploidentical bone marrow stem cells has extended this option to virtually all such infants, if diagnosed before untreatable infections develop. Finally, the past 3 years have witnessed the first truly successful gene therapy. The impressive results in X‐linked severe combined immunodeficiency offer hope that this approach can be extended to many more diseases in the future.
Studies of normal and neoplastic lymphocytes
Authors: Nowell Peter C.
Published: March 2003

Summary: This brief review encapsulates a nearly 50‐year career in biomedical research, primarily studying human leukemias and lymphomas, but also involving normal lymphocytes. Early observations included the feasibility of bone marrow transplantation (and related problems with graft‐vs.‐host reactions); the mitogenic effect of phytohemagglutinin (and resultant human lymphocyte culture techniques); and early cytogenetic findings in human leukemias, both lymphocytic and myeloid (including the Philadelphia chromosome). Subsequent studies of normal human lymphocytes have contributed to our enormously expanding knowledge of their basic biology, especially regulatory pathways, both extracellular and intracellular. Further work with human lymphoid neoplasms has helped extend the early chromosomal findings to the specific genes involved, including several regulating apoptosis; and also contributed to the concept of clonal evolution as a basic underlying mechanism of tumorigenesis in general. This career has covered a period of remarkable growth of knowledge concerning both normal and neoplastic lymphocytes, with potential for many important future clinical applications; it has been a privilege to participate.
Genetic diversity of the human immunoglobulin heavy chain VHregion
Authors: Li Honghua , Cui Xiangfeng , Pramanik Sreemanta , Chimge Nyam‐Osor
Published: March 2003

Summary:The human immunoglobulin heavy chain VHregion is one of the most complex regions in the human genome. The high level of diversity of this region has been shown by a number of studies. However, because of the limitations of the conventional experimental methods, it has been difficult to learn the extent of the diversity and the underlying mechanisms. This review describes a number of new genetic approaches developed in the authors' laboratory. By using these approaches, significant progress has been made in assigning different VHsequences to their respective loci, in learning the diversity of gene segment number and composition among the VHhaplotypes, and in learning VHgene segment organization in individual haplotypes. Information obtained toward this direction could help in understanding the mechanisms underlying VHregion diversity and the biological impact of the VHregion diversity.
Genomics‐based approaches to gene discovery in innate immunity
Authors: Scheetz Todd , Bartlett Jennifer A. , Walters Jesse D. , Schutte Brian C. , Casavant Thomas L. , B. McCray Paul
Published: March 2003

Summary: The completion of draft sequences of the human and mouse genomes offers many opportunities for gene discovery in the field of immunology through the application of the methods of computational genomics. One arm of the innate immune system includes the antimicrobial peptides that protect multicellular organisms from a diverse spectrum of microorganisms. The β‐defensins comprise an important family of mammalian antimicrobial peptides. To better define the β‐defensin gene family, we developed an approach to search genomic databases for conserved motifs present in the β‐defensin family using HMMER, a computational search tool based on hidden Markov models (HMMs), in combination with the basic local alignment search tool. The approach was first used to identify candidate second‐exon coding regions, and later applied to finding associated first exons. This strategy discovered 28 new human and 43 new mouse β‐defensin genes in five syntenic chromosomal regions. Within each syntenic cluster, the gene sequences and organization were similar, suggesting that each cluster pair arose from a common ancestor and was retained because of conserved functions. These findings demonstrate an important proof‐of‐principle for a genome‐wide search strategy to identify genes with conserved structural motifs. Such an approach may be readily adopted to address other questions of relevance to immunology.
Role of protein tyrosine phosphatases in T cell activation
Authors: Mustelin Tomas , Rahmouni Souad , Bottini Nunzio , Alonso Andres
Published: March 2003

The last decade has seen an exponentially increasing interest in the molecular mechanisms of signal transduction. In T cells, much of the focus has been on protein tyrosine kinase (PTK)‐mediated signaling from the T cell receptor (TCR) and cytokine receptors, while the study of protein tyrosine phosphatases (PTPases) has lagged behind. However, recent discoveries have revealed that several PTPases play important roles in many different aspects of T cell physiology. We predict that the phosphatases will become a ‘hot topic’ in the field within the next few years. This review summarizes the current understanding of the regulation and biology of PTPases in T lymphocyte activation.
An evolutionary and structural perspective on T cell antigen receptor function
Authors: Malissen Bernard
Published: March 2003

After a brief overview of the themes and variations that occur in the family of receptors containing immunoreceptor tyrosine‐based activation motifs (ITAMs), and of recent structural data on the ligand‐binding subunits of these receptors, we use these data to revisit how information on the state and quality of occupancy of the binding site of the T cell antigen receptor (TCR) is conveyed to the proximal components of the TCR transduction cassette.
Biliary excretion of bile acids and organic anions in zone 1‐ and zone 3‐injured rats
Authors: Aiso Mitsuhiko , Takikawa Hajime , Yamanaka Masami
Published: March 2003

Abstract: Aims: Hepatocytes in zone 1 of the hepatic lobule play a role in the uptake and biliary excretion of bile acids and organic anions under physiological conditions, and those in zone 3 may play a role only with a high‐dose load. To further elucidate the role of hepatic zonation on the handling of bile acids and organic anions, biliary excretion of these compounds was studied in zone 1‐ and zone 3‐injured rats. Methods: Biliary excretion of bile acids and organic anions was studied in zone 1‐ and zone 3‐injured rats, caused by allyl alcohol and bromobenzene, respectively. Results: Biliary excretion of a tracer dose of taurocholate was unchanged in the injury in both zones, but that of leukotriene C4 was decreased in zone 1 injury. The excretory maximum of taurocholate was decreased with zone 1 and the zone 3 injuries. Biliary excretion of deoxycholate metabolites was decreased in zone 3 injury, although the profile of metabolites in the bile was unchanged. Sulfobromophthalein excretion was decreased in zone 1 injury, but unchanged in zone 3 injury. Conclusions: These findings indicate that zone 1 is very important for biliary excretion of both organic anions and bile acids. In contrast, zone 3 is considered not to have a role in biliary excretion of organic anions, but to play a role in the excretion of bile acids.
Expression of cyclin D1, cyclin E, cdk4 and loss of heterozygosity of 8p, 13q, 17p in hepatocellular carcinoma: comparison study of childhood and adult hepatocellular carcinoma
Authors: Kim Hanseong , Lee Min Jae , Kim Mi Ran , Chung In Pyung , Kim Yeon Mee , Lee Jung Young , Jang Ja‐June
Published: March 2003

Abstract: Aims/Background: In hepatitis B virus‐related hepatocellular carcinoma(HCC), at least 20–40 years of continuous necro‐inflammation is necessary for the hepato‐carcinogenesis to occur. However, HCC in childhood shows an unusually short latent period and rapid progression. In our previous report, mutation of c‐met was found only in childhood HCC, but not in adult HCC. In order to determine the specific biological tumorous features of childhood HCC, a comparison study of childhood and adult HCC was performed. Methods: Eighteen cases of HBV positive HCC (nine children and nine adults aged more than 40 years) were selected. The expression of G1 phase regulatory proteins (cyclin D1, cyclin E and cdk4) was studied using immunohistochemical methods. Loss of heterozygosity (LOH) on chromosomal arms 8p, 13q and 17p was analyzed. Results: Cyclin D1 expression was significantly lower in childhood HCC than in adult HCC (cases of cyclin D1 expression under 3+: childhood 5/9 vs. adult 1/9, p=0.046). No difference in cyclin E and cdk4 expression was found between childhood and adult HCC. LOH frequency on 13q was relatively higher in childhood than in adult HCC (66.7% vs. 22.2%, p=0.058). LOH frequency on 8p and 17p was 44.4% and 33.3% in childhood HCC and 44.4% and 75% in adult HCC with no statistical significance between the two groups. Conclusion: Our data suggest that childhood HCC may be less dependent on cyclin D1 protein for tumor growth and progression than adult HCC, and that the LOH on 13q may be an important feature of childhood HCC.
Protein expression of MDM2 and its clinicopathological relationships in human hepatocellular carcinoma
Authors: Endo Kanenori , Ueda Tsuyoshi , Ohta Tetsuo , Terada Tadashi
Published: March 2003

Abstract: Background/Aims: The transcription of mdm2 gene is activated by p53 and this limits the growth‐suppressing activity of p53 by direct binding. It has been reported that MDM2 protein is overexpressed in several types of cancers. However, there have been no immunohistochemical studies on MDM2 in human hepatocellular carcinoma (HCC). Methods: We immunohistochemically examined the expression of MDM2 and the relationships between its expression and histological grade, clinicopathological parameters, p53 expression and patient survival in 107 patients with HCC. Results: The frequency of MDM2 positivity in the nuclei of HCC cells was 28/107 (26%). There was no correlation between the MDM2 expression and HCC grade. However, positivity of MDM2 expression significantly correlated with small HCC size (p<0.05, χ2 test) and the absence of vascular invasion (p<0.01, χ2 test). No significant differences were noted between MDM2 expression and capsular invasion or satellite nodules. Expression of MDM2 showed a significantly positive correlation with expression of p53 (p<0.03, χ2 test). Patients with positive expression of MDM2 had poorer prognosis than patients with negative MDM2 expression. MDM2 expression was the most useful independent factor for overall survival (p=0.0001). Conclusions: MDM2 was expressed in 26% of HCC, and its expression correlated positively with p53 mutations. MDM2 over‐expression is a useful predictor of poor prognosis in patients with HCC following hepatic resection.
A novel binding site for the native hepatic acute‐phase protein α1‐antitrypsin expressed on the human hepatoma cell line HepG 2 and intestinal cell line Caco 2
Authors: Graziadei Ivo , Vogel Wolfgang , Bomford Adrian
Published: March 2003

Abstract: Aims/Background:α1‐antitrypsin (α1‐AT) is a hepatic acute phase protein which predominantly inhibits neutrophil elastase. Besides this major function, we have also previously shown that α1‐AT markedly increased H‐ferritin mRNA expression and ferritin synthesis in the human hepatoma cell line HepG 2. These actions suggest that α1‐AT might interact with HepG 2 cells via a specific cell surface binding site. Methods and Results: Using radio‐labelled native α1‐AT, we observed saturable binding to HepG 2 cells with a dissociation constant (Kd) of 63.3±6.9 nM and a maximal density of binding sites (Bmax) of 0.34 ±0.05 pmol/106 cells equivalent to 195800±29200 sites/cell. The binding of [125I]α1‐AT was time dependent with a calculated association rate constant of 9.22±1.84×104×M−1×min−1. Binding was highly specific since other acute phase proteins or protease inhibitors failed to block binding. Although α1‐AT‐trypsin, α1‐AT‐elastase and the pentapeptide FVYLI, the minimal binding sequence for the SEC receptor, increased [125I]α1‐AT binding, in long term experiments these complexes failed to influence the number of α1‐AT binding sites. Specific, saturable binding of [125I]α1‐AT was also found on the human intestinal epithelial Caco 2 cells, but not on fibroblast or leukaemic cell lines. Conclusion: These experiments demonstrate a specific, high affinity binding site for native α1‐AT on HepG 2 and Caco 2 cells, cell lines derived from tissues involved in the acute phase response.
Do gastric and oesophageal varices bleed at different portal pressures and is TIPS an effective treatment?
Authors: Rees Colin J. , Nylander David L. , Thompson Nicholas P. , Rose John D. , Record Christopher O. , Hudson Mark
Published: March 2003

Abstract: Background: It has been suggested that gastric varices bleed at lower portosystemic pressure gradients (PSPG) than oesophageal varices and that transjugular intrahepatic portosystemic shunt (TIPS) is a particularly effective treatment in these patients. Aims: This study was undertaken to assess the difference in PSPG measured at the time of TIPS insertion between patients bleeding from gastric and those bleeding from oesophageal varices. Rebleeding and mortality rates between the two groups were also compared. Patients and methods: In a five year period, 64 patients (36 males and 28 females) undergoing TIPS for acute variceal bleeding had PSPG measured at the time of TIPS insertion. 12 patients underwent TIPS for gastric variceal haemorrhage (GVH) and 52 for oesophageal variceal haemorrhage (OVH). The median age was 53 years and 40/64 patients (63%) had alcoholic liver disease. The median Child's Pugh score was 8 for GVH and 9 for OVH patients. Median follow up was 75 weeks. Results: There was no significant difference in median PSPG between patients with GVH, 21 mmHg (range 15–30 mmHg) and OVH, 22 mmHg (range 12–45 mmHg). Following TIPS, PSPG was 8.5 mmHg (range 3–11 mmHg) and 9 mmHg (range 4–20 mmHg) in GVH and OVH patients respectively. Rebleeding occurred in 2/12 (16%) GVH patients and 12/52 (23%) OVH patients (p=1.0). Mortality during follow up was 25% (4/12) in the GVH and 25% (13/52) in the OVH patients. Conclusion: In this study, there was no difference between the pressures at which gastric and oesophageal varices bled. Rebleeding and mortality rates were similar in the two groups. TIPS is equally effective in the treatment of both oesophageal and gastric variceal haemorrhage.
Long‐term responders without eradication of hepatitis C virus after interferon therapy: characterization of clinical profiles and incidence of hepatocellular carcinoma
Authors: Yabuuchi Iwao , Imai Yasuharu , Kawata Sumio , Tamura Shinji , Noda Shuzo , Inada Masami , Maeda Yuichi , Shirai Yasuhiro , Fukuzaki Takaaki , Kaji Itaru , Ishikawa Hideki , Matsuda Yukihiko , Nishikawa Masahiro , Seki Kouichi , Matsuzawa Yuji
Published: March 2003

Abstract: Aims/Background: The aim of this study was to determine the characteristics of patients with chronic hepatitis C showing long‐term normalization of alanine aminotransferase (ALT) without eradication of HCV RNA, as well as to investigate the incidence of hepatocellular carcinoma (HCC) in such patients. Methods: Four hundred and nineteen patients with histologically‐proven chronic hepatitis C who had received interferon (IFN) therapy were studied. Complete response (CR) was defined as persistent normalization of ALT levels with eradication of serum HCV RNA (n=126). Long‐term biochemical response with positive HCV RNA (HCV‐positive BR) was defined as a normal ALT level at 6 months after IFN therapy with further persistent normalization of ALT levels for 2 or more years without eradication of serum HCV RNA (n=49). All other patterns were classified as non‐response (NR, n=244). Results: Mean follow‐up periods of CR, HCV‐positive BR and NR groups were 4.9, 5.2 and 4.9 years, respectively. The HCV‐positive BR group had significantly higher serum HCV RNA levels and a higher rate of HCV serological group 1 classification than the CR group. The other characteristics of the HCV‐positive BR group were lower histologic activity, lower ALT levels, and a higher rate of females when compared with both the CR and NR groups. Histologic staging in the HCV‐positive BR group was significantly lower than that in the NR group. Cumulative incidences of HCC estimated by the Kaplan‐Meier method in both the CR and HCV‐positive BR groups were significantly lower than those in the NR group (log‐rank test, CR vs NR p<0.001, HCV‐positive BR vs NR p=0.026). Conclusion: The patients with HCV‐positive BR were virologically different from those with CR, and had lower ALT levels and histologic activity when compared to those with CR and NR.
Sequential occurrence of primary sclerosing cholangitis and autoimmune hepatitis type III in a patient with ulcerative colitis: a follow up study over 14 years
Authors: Domschke Wolfram , Klein Reinhild , Terracciano Luigi‐Maria , Jung Peter , Kirchner Thomas , Berg Peter A. , Bianchi Leonardo
Published: March 2003

Abstract: In 1983, a female patient born in 1963 presented with symptoms of ulcerative colitis and typical clinical and histological signs of primary sclerosing cholangitis (PSC). At this time only pANCA were positive while other marker antibodies for autoimmune liver disorders could not be detected. In summer 1987 the clinical picture changed and was replaced by laboratory and histological signs typical of autoimmune hepatitis (AIH). Thus, IgG levels increased considerably and cholestatic enzymes became normal. For the first time, anti‐liver‐pancreas antibodies (LP), a diagnostic marker for AIH type III could be detected. In the following years several relapses occurred also induced by repeated discontinuation of immunosuppressive therapy. Symptoms of colitis persisted but signs of cholestasis remained absent for the following ten years. In 1997, colitis exacerbated again and colectomy had to be performed together with liver transplantation. Surprisingly, histology of the explanted liver now showed the typical features of PSC stage III/IV while the significant criteria for AIH were now lacking. Thus, progression to cirrhosis was, probably, mainly induced by the biliary destructive and fibrotic process although biochemical and serological data were clearly indicative of an autoimmune, i.e. AIH‐related manifestation.
Integrity of the NS5A (amino acid 2209 to 2248) region in hepatitis C virus 1b patients non‐responsive to interferon therapy
Authors: Halfon Philippe , Halimi Gilles , Bourlière Marc , Ouzan Denis , Durant Jacques , Khiri Hascene , Mercier Laurence , Gerolami Victoria , Cartouzou Guy
Published: March 2003

Abstract: Background/Aims: In hepatitis C virus‐1b, it has been suggested that an amino acid stretch (aa 2209–2248) of the carboxy terminal half of the non‐structural 5A (NS5A) region participates in the response to interferon treatment. We tested the hypothesis that absence of mutations in the NS5A (aa 2209–2248) sequence is required for interferon resistance. We also investigated the importance of different HCV‐1b isolates in interferon response in France. Methods: We determined the NS5A sequences of 70 patients with chronic hepatitis C before IFN therapy and then compared them with HCV‐J prototype sequence. The isolates were determined by NS5B sequencing, the “gold standard” method for genotyping and subtyping. Pre‐therapeutic viral load was also measured. Results: No sustained virological response was observed in the patients without amino acid substitutions in the NS5A (aa 2209–2248) sequence, and in the patients with HCV‐J isolates. Viral load was significantly higher in the patients with no amino acid substitutions in the NS5A (aa 2209–2248) sequence. Conclusions: In HCV‐1b infected patients, an HCV‐J strain with no amino acid substitution in the NS5A (aa 2209–2248) region indicates a poor prognosis for response to IFN therapy. The low interferon response rate in HCV‐1b infection in Europe is probably not due to a difference between isolates.
Morphology of liver repair following cholestatic liver injury: resolution of ductal hyperplasia, matrix deposition and regression of myofibroblasts Note
Authors: Ramm Grant A. , Carr Sandra C. , Bridle Kim R. , Li Lin , Britton Robert S. , Crawford Darrell H. G. , Vogler Carol A. , Bacon Bruce R. , Tracy Thomas F.
Published: March 2003

Abstract: Background/Aims: Myofibroblasts are the primary cells responsible for increased matrix deposition in hepatic fibrosis. Activation of hepatic stellate cells and portal fibroblasts to myofibroblasts during cholestatic liver injury is accompanied by increased expression of the activation marker, α‐smooth muscle actin (SMA), and collagen genes. In contrast to our understanding of injury, the cellular mechanisms of liver repair are not well defined. This study was designed to examine the morphological relationship between bile duct hyperplasia, matrix deposition and myofibroblast phenotype in a model of chronic cholestatic liver injury and repair. Methods: Reversible extrahepatic obstruction was accomplished in rats using a soft vessel loop suspended from the anterior abdominal wall: duct manipulation alone was performed in sham‐operated controls. After 7 days, rats were either sacrificed or decompressed by release of the loop and subsequently sacrificed 2–10 days after reversal. Liver sections were obtained for in situ hybridization for procollagen α1(I) mRNA, immunohistochemical staining for SMA and cytokeratin 19, and histochemical staining for reticulin. Results: Cholestatic livers demonstrated bile duct hyperplasia, which reversed to normal within 10 days after decompression. Fibrosis was also substantially reduced during this period. SMA‐positive myofibroblasts were abundant and localized to regions adjacent to proliferating ducts and excess matrix in the obstructed animals. Decompressed livers showed a dramatic time‐dependent reduction in the number of SMA‐positive cells and in the expression of procollagen I mRNA. Conclusions: Our results show that the disappearance of bile duct hyperplasia after biliary decompression is accompanied by a similarly rapid loss of SMA‐positive myofibroblasts. Both cellular events may abrogate enhanced matrix synthesis and allow repair to occur.
Severe exacerbation of hepatitis after short‐term corticosteroid therapy in a patient with “latent” chronic hepatitis B
Authors: Shiota Goshi , Harada Ken‐ichi , Oyama Kenji , Udagawa Akihide , Nomi Takahiro , Tanaka Kiwamu , Tsutsumi Atsushi , Noguchi Naoya , Kishimoto Yosuke , Horie Yutaka , Suou Takeaki , Kawasaki Hironaka
Published: March 2003

Abstract: We present a case of severe exacerbation of hepatitis after short‐term corticosteroid therapy for chronic inflammatory demyelinating polyneuropathy (CIPD) with “latent” chronic hepatitis B showing no HBV‐related antigens and antibodies. After corticosteroid pulse therapy for CIPD, the patient had severe exacerbation of hepatitis twice. Although she did not show any hepatitis B virus (HBV)‐related antigens or antibodies, sequences of HBV were detected in serum and liver by a nested polymerase chain reaction. A sequence analysis of HBV at the second exacerbation showed that the G‐to‐A point mutation at nucleotide 1896 that converted codon 28 from tryptophan (TGG) to a stop codon (TAG) in the precore region resulted in amino acid change, which has been frequently observed in fulminant hepatitis and severe hepatitis in Japan.