bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver transplantation for hepatocellular carcinoma
Authors: Steinmüller T. , Jonas S. , Neuhaus P.
Published: June 2003

Despite recent advances in techniques of in situ tumour ablation, surgical therapy remains at present the mainstay treatment for primary hepatic malignancies. After an initial endeavour in the establishment of liver transplantation as a treatment option, in particular for unresectable liver tumours, only a few indications, for example early hepatocellular carcinoma in cirrhosis, are currently agreed upon. Other indications, such as peripheral cholangiocarcinoma and hepatocellular carcinoma in noncirrhotics have largely been abandoned or are still under debate, as is the case with fibrolamellar carcinoma. The selection of patients suffering from hepatocellular carcinoma in cirrhosis for liver transplantation is still based on tumour size and node number, because the current state of diagnostic imaging fails to reliably predict the most important prognostic parameter: vascular infiltration. Other selection criteria are under investigation. Studies on multimodal therapy are also underway but have not yet demonstrated a clear benefit.
Maintenance treatment of Crohn's disease
Authors: Biancone L. , Tosti C. , Fina D. , Fantini M. , De Nigris F. , Geremia A. , Pallone F.
Published: June 2003

The aetiology of Crohn's disease is unknown and therefore no curative treatments are available for the disease. The natural history of Crohn's disease is characterized by recurrent flare‐ups of symptoms. Several drug treatments are effective in inducing clinical remission. However, no drug treatments are available in order to prevent clinical relapses, although several drug regimens may delay clinical flare‐ups. Crohn's disease treatment for maintaining clinical remission needs to be tailored in relation to specific characteristics of each patient. The frequency of clinical relapse indeed shows marked variations in subgroups of patients, as the likelyhood of relapse is higher in patients in clinical remission for less than 6 months. Treatment strategies for maintaining remission may therefore differ among inactive patients. In chronically active, steroid‐dependent or steroid‐refractory Crohn's disease patients immunomodulatory drugs (azathioprine 2–2.5 mg/kg by mouth, 6‐mercaptopurine 1–1.5 mg/kg by mouth, or methotrexate 15–25 mg/i.m./week) should be added to oral mesalazine (2.4 g/day), while in long‐term inactive Crohn's disease patients mesalazine alone may be effective in delaying relapse. Recently, treatment with anti‐tumour necrosis factor‐α monoclonal antibodies (Infliximab or CDP571) has shown efficacy in delaying relapse in responsive patients. One other issue which needs to be considered before selecting drug treatments for maintaining remission in Crohn's disease, is that Crohn's disease activity is currently assessed on the basis of standard clinical scores which may not appropriately reflect the biological activity of the disease. Clinical remission as defined by standardized scores may include heterogeneous subgroups of patients showing different endoscopic and histological activity or persistence of activated immunocompetent cells within the gut. Several sub‐clinical markers of relapse have indeed been reported in quiescent Crohn's disease, although their usefulness in clinical practice in currently uncertain.
Percutaneous treatment of hepatocellular carcinoma
Authors: Gaiani S. , Celli N. , Cecilioni L. , Piscaglia F. , Bolondi L.
Published: June 2003

In early stage hepatocellular carcinoma (HCC), liver transplantation, surgical resection and percutaneous techniques are classified as radical treatments, and may be offered to about 25% of all patients with HCC evaluated in referral centres.

The restricted inclusion criteria for surgical resection and the shortage of liver donors for transplantation have stimulated an increasing demand for minimally invasive treatments able to achieve effective and reproducible percutaneous tumour ablation, with less associated morbidity and lower cost than other interventions.

Among percutaneous techniques, ethanol injection has proven to be highly effective in single HCC up to 3 cm, with a rate of complete response of 80%, being well tolerated and with a limited risk of minor complication. In larger and/or multinodular HCC the efficacy is reduced to 50% of complete response in nodules between 3 and 5 cm, and to lower rate in larger tumours.

Alternative options to ethanol injection have been recently proposed, including radiofrequency, microwave and laser thermal ablation, aimed to extend the necrotic area thus improving the rate of complete response. To date, radiofrequency is the most used technique, with a reported rate of complete response of 90–98% in nodules smaller than 3 cm, and with the advantage of fewer sessions, otherwise counteracted by a higher rate of side‐effects. Microwave and laser are promising technologies, but only few clinical data are available.

Randomized controlled trials are needed in order to assess treatment response, long‐term survival, rate of complication and cost‐efficacy of newer technologies in comparison to ethanol injection.
Diagnosis, monitoring and treatment of distal colitis
Authors: Vecchi M. , Saibeni S. , Devani M. , Rondonotti E. , De Franchis R.
Published: June 2003

The diagnostic work‐up of ulcerative colitis at presentation is based on the collection of clinical, microbiological, radiological, endoscopic and histologic data. Serological markers are characterized by too low a sensitivity to be commonly utilized in clinical practice. Although endoscopic and histologic features are characterized by very high sensitivity and specificity for the diagnosis of ulcerative colitis, negative stool cultures and parasites are mandatory to exclude an infectious aetiology at presentation. The treatment of choice of an acute flare‐up of distal ulcerative colitis is represented by oral or topical mesalazine, or a combination of both, whereas the use of topical or systemic steroids should be restricted to patients who prove to be refractory to first‐line treatments. Preliminary data suggest that the achievement of endoscopic and histologic remission after an acute flare of the disease might be associated with a prolonged remission.
Indications for anti‐reflux surgery in gastro‐oesophageal reflux disease
Authors: Mattioli S. , Lugaresi M. L. , Pierluigi M. , Di Simone M. P. , D'Ovidio F.
Published: June 2003

Gastro‐oesophageal reflux disease (GERD) is a complex multifactorial disorder whose treatment is based on knowledge of its pathophysiology, natural history and evolution. Recently the relationship between the severest degrees of cardial incontinence and hiatus hernia has been emphasized, which causes the impairment of the mechanical properties of the gastro–oesophageal barrier and of oesophageal acid clearing. Among different types of hiatus hernia, those characterized by the permanent axial orad migration of the oesophago‐gastric (EG) junction (nonreducible hiatus hernia) are correlated with severe GERD. Barium swallow may adequately differentiate hiatal insufficiency, concentric hiatus hernia and short oesophagus which are the steps of migration across or above the diaphragm. When associated with panmural oesophagitis and fibrosis of the oesophageal wall, these conditions may be the cause of recurrence of hiatus hernia and reflux after laparoscopic standard anti‐reflux surgical procedures; in the presence of nonreducibility of the EG junction below the diaphragm without tension, dedicated surgical procedures are necessary. It is currently agreed that surgical therapy is indicated for patients affected by severe GERD who are not compliant with long‐term medical therapy, require high dosages of drugs and are too young for lifetime medical treatment. While the existence of severe GERD correlated with an irreversible anatomical disorder represents an elective indication for surgery, warrants further investigation. Accurate identification of the functional and anatomical abnormalities underlying GERD is mandatory in order to decide whether medical or surgical therapy should be implemented, and to tailor the surgical technique, laparoscopic or open, to each patient.
Management of mild and severe gastro‐oesophageal reflux disease
Authors: Tytgat G. N. J.
Published: June 2003

Treatment of endosocopy‐negative gastro‐oesophageal reflux disease (s‐GERD) should be directed towards rapid relief of symptoms and then maintenance of relief using minimum yet effective therapy. Responses to proton pump inhibitors are somewhat lower in s‐GERD patients compared to GERD with overt erosive damage (e‐GERD). The reasons for a lower response rate are not clear but may relate to the inclusion of patients who do not have reflux disease or patients with a lower oesophageal sensory threshold. Also poorly understood is the lower yield of complete heartburn relief when the number of associated dyspeptic symptoms is high. Some form of long‐term therapy is needed in the majority of patients. ‘On demand’ proton pump inhibitor therapy to control reflux symptoms is a new and attractive option. Time to study discontinuation due to insufficient control of heartburn, or any other reason resulting in unwillingness to continue with on‐demand therapy, is a pragmatic outcome that is well suited to definition of the efficacy of on‐demand therapy. The goals of treatment of e‐GERD should be to relieve symptoms and to heal lesions. Symptom severity and much less endoscopic abnormalities drives the therapeutic choices. When symptoms are mild or intermittent and when oesophagitis is of limited degree, standard dose proton pump inhibitor is usually instituted. Fewer and fewer clinicians would still opt for an H2‐receptor antagonist. If there is moderate or severe oesophagitis or if symptoms are particularly troublesome, then the patient should start with standard‐dose proton pump inhibitor therapy once a day, but not uncommonly a b.d. dosage maybe necessary. Once the dose of the acid suppressant that relieves symptoms is found, this dose should be maintained for a period of 3 months. After this time, an attempt should be made to reduce the dose. If symptoms recur, then the patients should go back to the full‐dose proton pump inhibitor and a plan should be formulated for long‐term treatment. The long‐term treatment options vary between ongoing acid and suppressant therapy, with occasional attempts to reduce the dose, or to go for ‘on demand’ therapy and (rarely) includes consideration for surgery or endoscopic anti‐reflux therapy.
Test and treat or treat and test in reflux disease?
Authors: Vakil N.
Published: June 2003

The role of diagnostic testing in reflux disease is in evolution. There is little question that patients with dysphagia, bleeding or other ‘alarm’ symptoms, should undergo early endoscopy. A substantial proportion of patients presenting with reflux symptoms have endoscopy negative reflux disease. pH testing is both inconvenient and lacks the sensitivity and specificity required for a ‘gold standard’. Empirical trials of therapy using proton pump inhibitors have shown that a trial of treatment may be the most accurate way of diagnosing gastro‐oesophageal reflux disease (GERD) and may the optimal strategy from a cost‐effectiveness standpoint. On the other hand, the increasing rate of oesophageal adenocarcinoma has raised questions about the possible value of screening endoscopy to determine if Barrett's oesophagus is present. The role of endoscopic testing in the average patient is therefore shifting from a diagnostic modality to one that helps manage risk by identifying Barrett's oesophagus.
Liver transplantation for HCC. Treatment options on the waiting list
Authors: Bolondi L. , Piscaglia F. , Camaggi V. , Grazi G. L. , Cavallari A.
Published: June 2003

The most widely adopted criteria to admit and maintain patients with HCC and cirrhosis in the waiting list for liver transplantation are the Milano criteria, consisting in the presence of a single tumour ≤5 cm in diameter or up to three tumours, none exceeding 3 cm in diameter. Since the average time to transplantation has become longer than 10–12 months in most European and American Centers, the exclusion from the list during the waiting period due to increase of the neoplasm over the established criteria is not uncommon at present. It is mandatory, therefore, to seek an effective therapeutic strategy for patients with HCC waiting for transplantation. Surgical resection and eventual subsequent salvage transplantation seems a cost‐effective strategy in resectable HCC. In unresectable neoplasms both transarterial chemoembolization and percutaneous ablation techniques are currently used and one or the other are chosen according to individual applicability, limitations and specific risks. However, although positive trends were reported, no definitive evidence has been produced so far about their efficacy in increasing patient's survival and decreasing tumour recurrence rates after transplantation. Adult‐to‐adult living donor liver transplantation is one possible way to shorten the waiting list, but this strategy involves important ethical implications. At present it appears justified to take it into consideration only if the waiting time for cadaveric OLT is expected to exceed 7 months. A more general and definitive attempt to overcome problems related to long waiting times for patients with HCC and relatively preserved hepatic function has been introduced in the USA very recently and consists in prioritizing patients with HCC. However, the overall efficacy of this approach will be established only in some years.
Liver resection for hepatocellular carcinoma in cirrhotics and noncirrhotics. Evaluation of clinicopathologic features and comparison of risk factors for long‐term survival and tumour recurrence in a single centre
Authors: Grazi G. L. , Cescon M. , Ravaioli M. , Ercolani G. , Gardini A. , Del Gaudio M. , Vetrone G. , Cavallari A.
Published: June 2003

Background : Differences in risk factors for survival and recurrence after liver resection for hepatocellular carcinoma (HCC) in patients with or without cirrhosis are not fully clarified.

Aim : To review a single‐centre experience of curative liver resections for HCC in order to evaluate clinicopathologic features and the long‐term outcome of cirrhotic and noncirrhotic patients.

Methods : From 1981 to 2002, 308 curative liver resections for HCC on cirrhosis (Group 1) and 135 for HCC without cirrhosis (Group 2) were performed. The main demographic, clinicopathologic and operative parameters, as well as early results were analysed and compared. Overall and disease‐free survival were evaluated. Prognostic factors for survival and for tumour recurrence were studied by univariate and multivariate analysis.

Results : Group 1 had worse preoperative liver function and higher frequency of hepatitis C virus infection. In Group 2, HCC showed larger mean tumour diameter (P < 0.001), poorer differentiation (P < 0.05) and more frequent macrovascular invasion (P < 0.05). Although more extended resections were performed in Group 2 (P < 0.001), there were no differences in blood transfusions, while post‐operative complication rate was higher in Group 1 (P < 0.005). After 1992, in‐hospital mortality was 2.9% in Group 1 and 1.1% in Group 2 (P = N.S.). The 3‐ and 5‐year overall survival was 63.7% and 42.2% in Group 1, and 67.9% and 51% in Group 2 (P < 0.05). The 3‐ and 5‐year disease‐free survival was 49.3% and 27.8% in Group 1, and 58% and 45.6% in Group 2 (P < 0.005). Serum bilirubin level > 1.2 mg/dL, multiple nodules, micro and macrovascular invasion, diaphragm infiltration and blood transfusions independently affected survival in Group 1. Blood replacement was the only negative prognostic factor in Group 2. Independent risk factors for tumour recurrence were satellite nodules and resection performed before 1992 in Group 1, and age < 60 in Group 2.

Conclusions : Despite a more aggressive behaviour, HCC without cirrhosis led to better overall and disease‐free survival compared to HCC with cirrhosis after curative liver resection. Age and intra‐operative blood transfusions are the only predictors of outcome in patients without cirrhosis. The impact of the latter on long‐term survival in both our groups outlines the importance of surgical technique on the results of hepatectomies.
Transcranial Doppler ultrasonography in siblings with sickle cell disease
Authors: Kwiatkowski Janet L. , Hunter Jill V. , Smith‐Whitley Kim , Katz Mira L. , Shults Justine , Ohene‐Frempong Kwaku
Published: June 2003

Summary. The risk of stroke in sickle cell disease (SCD) may be influenced by either genetic or environmental factors. Elevated blood flow velocity in the large cerebral arteries, detected by transcranial Doppler (TCD) ultrasonography, predicts an increased stroke risk in children with SCD. We undertook this study to investigate the possibility of a familial predisposition to elevated cerebral blood flow velocity, a surrogate marker for stroke risk. We analysed the results of TCD studies performed on 63 children from 29 families that had more than one child with SCD. We assessed the association of elevated cerebral blood flow velocity with sibling TCD results as well as age and haemoglobin level, which are factors known to affect cerebral blood flow velocity. Positive or negative TCD results were highly correlated between family members (r = 0·61). The presence of a sibling with a positive TCD result was significantly associated with an elevated cerebral blood flow velocity in other siblings with SCD (odds ratio = 50·7, 95% confidence interval 10·1–253·7, P < 0·001). Furthermore, children who had a sibling with a positive TCD result had a significantly higher TCD velocity than children with SCD but without a sibling who were matched for age, sex, genotype and haemoglobin level. Our results are consistent with a familial predisposition to cerebral vasculopathy in SCD.
Bone marrow biopsy morbidity and mortality
Authors: Bain Barbara J.
Published: June 2003

Summary.  A postal survey of adverse events associated with bone marrow biopsy (aspiration biopsy with or without trephine biopsy) was carried out among British Society of Haematology members, between 1995 and 2001. A total of 26 adverse events, including one death directly attributable to the procedure, were reported among an estimated 54 890 biopsies. The most frequent and most serious adverse event was haemorrhage, reported in 14 patients, necessitating blood transfusion in six patients and leading to the single death. The potential risk factors most often associated with haemorrhage were a diagnosis of a myeloproliferative disorder, aspirin therapy or both. Other potential risk factors were warfarin therapy, disseminated intravascular coagulation and obesity.
T‐large granular lymphocyte lymphoproliferative disorder: expression of CD26 as a marker of clinically aggressive disease and characterization of marrow inhibition
Authors: Dang Nam H. , Aytac Ugur , Sato Kazuya , O'Brien Susan , Melenhorst Jos , Morimoto Chikao , Barrett A. John , Molldrem Jeffrey J.
Published: June 2003

Summary. T‐large granular lymphocyte lymphoproliferative disorder (T‐LGL LPD) is an indolent disease characterized by prolonged cytopenia and the presence of circulating large granular lymphocytes in the patient's peripheral blood. Although the disease is commonly thought of as indolent, most patients eventually require therapy because of recurrent infections secondary to neutropenia as well as a need for frequent blood product transfusions. CD26 is a 110‐kDa surface glycoprotein with an essential role in T‐cell function, including being a marker of T‐cell activation and a mediator of T‐cell activating signals. In this study, we evaluated CD26 expression in T‐LGL patients and correlate CD26 expression with clinical behaviour. In addition, we examined the potential mechanism of cytopenia that is associated with this disorder. Our findings suggest that CD26 is a marker of aggressive T‐LGL LPD and that CD26‐related signalling may be aberrant in T‐LGL LPD. Furthermore, inhibition of granulocyte–macrophage colony‐forming units may be mediated by CD8+ cells of T‐LGL LPD patients and is major histocompatibility complex class I‐restricted.
Dissociation of ABH antigen expression from von Willebrand factor synthesis in endothelial cell lines
Authors: O'Donnell James , Laffan Michael A.
Published: June 2003

Summary. ABO blood group determines plasma von Willebrand factor (VWF) levels and ABH antigens are present on VWF. To investigate whether ABO influences the rate of VWF synthesis, we performed stable transfection of A transferase in a phenotypically group‐O endothelial cell line (EAhy926). A transferase expression did not affect the rate of VWF synthesis. Although high levels of A antigen were expressed on the cell surface, no A determinants were added to VWF synthesized within these cells. Further studies demonstrated H structures were not present on EAhy926‐derived VWF, despite the fact that H antigen is constitutively expressed by these cells.
Reduction of cell cycle progression in human erythroid progenitor cells treated with tumour necrosis factor alpha occurs with reduced CDK6 and is partially reversed by CDK6 transduction
Authors: Dai Chunhua , Chung Ik‐Joo , Jiang Shazi , Price James O. , Krantz Sanford B.
Published: June 2003

Summary. Tumor necrosis factor α (TNFα) potently inhibits the in vitro growth of highly purified human d‐6 erythroid colony forming cells (ECFC). Unlike the inhibitory effect of TNFα on other cells, including more immature ECFC, this antiproliferative effect of TNFα is not related to apoptosis because the d‐6 cell descendants were morphologically normal, without apoptosis by terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick‐end labelling assay and without caspase activation by Western blots after TNFα treatment. TNFα did not appear to affect the cell cycle distribution, but the cell cycle duration was significantly longer in TNFα‐treated cells. DNA synthesis was also significantly reduced by TNFα. Studies of various proteins that regulate the cell cycle showed that cyclin‐dependent kinase 6 (CDK6) protein and mRNA levels were concomitantly decreased in the presence of TNFα, suggesting that inhibition of cell growth was related to reduced CDK6. To evaluate this, the CDK6 gene was transferred into ECFC using green fluorescence protein‐retrovirus‐mediated gene transfer. The results showed that the level of cell growth produced by TNFα was increased by 30% when the cells were transfected with CDK6. Therefore, the modification of cell cycle progression in the presence of TNFα through a reduction of CDK6 is an important mechanism in the TNFα inhibition of human ECFC expansion.
A genome scan of 18 families with chronic lymphocytic leukaemia
Authors: Goldin Lynn R. , Ishibe Naoko , Sgambati Maria , Marti Gerald E. , Fontaine Laura , Lee Maxwell P. , Kelley Jenny M. , Scherpbier Titia , Buetow Kenneth H. , Caporaso Neil E.
Published: June 2003

Summary. Chronic lymphocytic leukaemia (CLL) accounts for about 30% of all leukaemias and is most prevalent in older individuals. Significant familial aggregation has been demonstrated but the mode of inheritance is unknown. Recurrent cytogenetic abnormalities are frequently found in CLL tumour cells but no susceptibility genes have been confirmed. We have collected clinical data and biospecimens on families ascertained for having at least two living patients with CLL. The current study included DNA samples from 94 individuals (38 affected patients) in 18 families. We have carried out a genome scan using the ABI 28‐panel medium density linkage mapping set (average spacing of 10 cM and average heterozygosity of 80%). Genotypes for 359 markers were scored. Multipoint limit of detection (lod) scores were calculated, assuming both dominant and recessive inheritance and allowing for increased penetrance with age and genetic heterogeneity. Non‐parametric linkage scores were also calculated. Lod scores of 1·0 or greater were found on regions of chromosomes 1, 3, 6, 12, 13 and 17, but none of these loci achieved statistical significance. Four of these six regions (6q, 13q, 12 and 17p) coincide with areas where cytogenetic abnormalities are frequently observed in CLL tumour cells and are, therefore, strong candidate regions for containing germ line changes.
Intracellular localization of glycoprotein VI in human platelets and its surface expression upon activation
Authors: Suzuki Hidenori , Murasaki Kagari , Kodama Kumi , Takayama Hiroshi
Published: June 2003

Summary. Glycoprotein (GP) VI is a major receptor for collagen and belongs to the immunoglobulin super family. Here, we examined the localization of GPVI in resting and activated human platelets by immunogold scanning and transmission electron microscopy and flow cytometry. Ultrastructural observation detected immunolabelling for GPVI that was distributed uniformly over the entire surface of resting platelets, and revealed that GPVI was also localized on both the membranes of the surface‐connected open canalicular system (OCS) and α‐granules. The OCS‐ and α‐granule‐associated GPVI pools were an estimated 35·4 ± 3·2% (mean ± standard deviation) of the total. Little GPVI labelling was observed in any part of GPVI‐deficient platelets. A remarkable time‐dependent increase in GPVI surface expression was found by flow cytometry when platelets were activated by collagen‐related peptide (CRP) and convulxin. The GPVI‐mediated activation of platelets by CRP or convulxin resulted in similar ultrastructural changes and an increased GPVI labelling density on the activated platelet surface, which was accompanied by a decreased interior expression. GPVI was also expressed on microparticles generated from activated platelets. Thus, our study demonstrates that platelets have internal pools of GPVI, and that GPVI is increasingly redistributed to the surface membrane and to microparticles during platelet activation.
Delayed‐onset neutropenia associated with rituximab therapy
Authors: Chaiwatanatorn Kritika , Lee Newton , Grigg Andrew , Filshie Robin , Firkin Frank
Published: June 2003

Summary. The characteristics of severe neutropenia with a delayed onset following administration of rituximab have been evaluated in 53 consecutively treated patients. All but one patient received rituximab for the treatment of non‐Hodgkin's lymphoma. Eight episodes of grade 4 neutropenia were detected between 1 and 5 months after rituximab, when administered alone on five occasions, and on three occasions in combination with chemotherapy, where neutrophil counts had recovered prior to the development of neutropenia. In three episodes, the patients presented with sepsis. Development of neutropenia did not correlate with either the presence of detectable disease or the administration of further treatment. Neutropenia was associated with selective depletion of neutrophil precursors in all but one episode, where it was associated with generalized bone marrow hypoplasia. All episodes developed after a period of either normal or mildly depressed neutrophil counts following treatment with rituximab, and persisted for between several days and several months, before undergoing spontaneous recovery in four instances, and after administration of filgrastim in the remainder. Episodes of neutropenia were associated with disordered immune status manifested by lymphopenia and hypogammaglobulinaemia, raising the possibility that either disturbance of the balance of lymphocyte subsets or an immune dyscrasia induced by rituximab resulted in the development of this type of neutropenia.
Lack of association between transporter associated with antigen processing (TAP) and HLA‐DM gene polymorphisms and antibody levels following measles vaccination
Authors: Dhiman N. , Ovsyannikova I. G. , Pinsky N. A. , Vierkant R. A. , Jacobsen S. J. , Jacobson R. M. , Poland G. A.
Published: June 2003

The transporter associated with antigen processing (TAP) and human leukocyte antigen‐DM (HLA‐DM) genes are involved in the antigen‐processing pathway of both HLA class I and class II‐restricted antigen presentation. We hypothesized that polymorphisms within the TAP and DM genes may influence antibody levels following measles vaccination. We examined TAP and DM polymorphisms in 242 school children from Olmsted County, Minnesota, USA who received one dose of measles‐mumps‐rubella‐II (MMR‐II) vaccine at the age of 15 months. Based on the level of serum measles‐specific immunoglobulin G (IgG) antibodies, subjects were classified as seronegatives (n = 72) or seropositives (n = 170). We determined TAP1 and TAP2 allele types by polymerase chain reaction (PCR) amplification of specific alleles (PASA) and determined DM allele type by PCR amplification followed by direct sequencing of the polymorphic sites. We analysed the data for any TAP or DM allelic association with antibody levels post measles vaccination using the chi‐square test and univariate linear regression analysis. We found no trend in the overall distribution of TAP and DM genotype frequencies between seronegative and seropositive subjects, suggesting that TAP and DM polymorphism and antibody levels following measles vaccination are not directly associated. In addition, we did not find an association between TAP (TAP1, P = 0.71; TAP2, P = 0.87) or DM (DMA, P = 0.42; DMB, P = 0.71) homozygosity and seronegativity to measles vaccine in this study group. Our study suggests that TAP and DM gene polymorphisms do not influence antibody levels post measles vaccination.
Tumour immunology, vaccination and escape strategies
Authors: García‐Lora A. , Algarra I. , Collado A. , Garrido F.
Published: June 2003

Our increasing knowledge of the mechanisms by which tumour cells escape immune effector cells is helping to establish new approaches to therapeutic vaccination against tumour development. One of the escape mechanisms used by tumour cells is the generation of multiple variants with different HLA phenotypes. These MHC class I phenotypic alterations play a key role in the tumour–host scenario, as they are crucial molecules for antigen presentation to T cells and modulation of natural killer (NK) cell activity. This review presents evidence indicating that tumours develop sophisticated MHC phenotypes that allow them to escape immune surveillance. We evaluate the importance of these alterations in terms of the potential development of therapeutic approaches to immune vaccination.
Recognition of HLA‐A*0248 in a Chinese donor
Authors: Yang K. L. , Gao X. , Lin P. Y.
Published: June 2003

HLA‐A*0248, a rare allele originally found in an individual of Filipino background, was detected in a Chinese donor. We confirmed the novel sequence and analysed its serological reaction pattern. The exon 2 sequence of A*0248 was apparently generated in a gene conversion event with an A2 gene, receiving a sequence segment comprising codons 56 to 74 from an A*24 donor gene. Serological typing showed a clear‐cut A2 reaction pattern, indicating that the three amino acid positions 62, 65 and 74, are probably not a critical part of the A2 epitope. Our typing experience also demonstrated that different typing technologies often complement each other in fine HLA typing.
Genetic variation in the IGSF6 gene and lack of association with inflammatory bowel disease
Authors: King K. , Moody A. , Fisher S. A. , Mirza M. M. , Cuthbert A. P. , Hampe J. , Sutherland‐Craggs A. , Sanderson J. , MacPherson A. J. , Forbes A. , Mansfield J. , Schreiber S. , Lewis C. M. , Mathew C. G.
Published: June 2003

The immunoglobulin superfamily 6 gene (IGSF6) on chromosome 16p11‐p12 has been investigated as a positional and functional candidate for inflammatory bowel disease (IBD) susceptibility. Screening of the six exons of IGSF6 for single nucleotide polymorphisms (SNPs) detected four novel SNPs, and validated three of six SNPs listed in the international SNP database (dbSNP). The seven SNPs in IGSF6 formed five distinct linkage disequilibrium groups. There was no evidence for association of the common SNPs with disease in a large cohort of patients with IBD. The novel SNPs and the linkage disequilibrium map will be a useful resource for the analysis of IGSF6 in other immune disorders.
A new allelic variation within the 5′‐flanking region of the interleukin‐10 gene
Authors: Rieth H. , Assohou A. C. , Mörmann M. , Roupelieva M. , Kremsner P. G. , Kube D.
Published: June 2003

At −2471 bp from the transcriptional start site of the interleukin‐10 (IL‐10) gene, the inverted repeat TG/CA was previously identified and designated IL‐10.IR. In an analysis of samples from 200 Germans (Caucasian) and 286 Gabonese (Central African), three different alleles, IL‐10.IR6, IL‐10.IR7 and IL‐10.IR8, were identified. In the Caucasians, IL‐10.IR6 and IL‐10.IR8 were found only once, in each case with IL‐10.IR7 as the corresponding second allele.
Comparison of TAP2 frequencies in type 1 diabetes patients and healthy controls from three ethnic groups indicates an African origin for the TAP2 G allele
Authors: Hoarau J. J. , Cesari M. , Dieye A. , Kotea N. , Surrun S. K. , Moine A. , Caillens H. , Cadet F. , Pabion M.
Published: June 2003

In order to determine the ethnic origin of the transporter associated with antigen processing 2 (TAP2) G allele, initially discovered by us in a group of type 1 diabetes (insulin‐dependent diabetes mellitus) patients living on Reunion Island, HLA TAP2 typing was performed using the polymerase chain reaction–amplification refractory mutation system (PCR‐ARMS) method in type 1 diabetes patients and unrelated healthy controls of three different ethnic groups (Caucasians, Indians and black Africans from Senegal and Mauritius). The comparison of TAP2 allele frequencies in controls showed significant racial (ethnic) differences. The TAP2*0101 and TAP2 C alleles were increased, respectively, in the Caucasian (50% in Caucasians vs. 40% in other groups) and Senegalese (27% in Senegalese vs. 10% in other groups) populations. In comparison with Caucasians, the TAP2*0201 variant was significantly increased in the Indian population and decreased in the Senegalese black population. In addition, the TAP2 G allele was observed in the two African populations studied but not in the Caucasian or Indian population. This observation is consistent with the view that this allele is restricted to populations of African origin. In addition, we have determined the large extended haplotype DQA1‐DQB1‐DRB1 associated with TAP2 G. We found that this allele is preferentially associated with the large conserved haplotype HLA DQA1*0501‐DQB1*0201‐DRB1*0301.
The distribution of 13 killer‐cell immunoglobulin‐like receptor loci in UK blood donors from three ethnic groups
Authors: Cook M. A. , Moss P. A. H. , Briggs D. C.
Published: June 2003

Killer‐cell immunoglobulin‐like receptors (KIRs) can inhibit the killing activity of natural killer (NK) cells if they interact with their ligand, class I HLA. Using a modified polymerase chain reaction–sequence‐specific primers (PCR‐SSP) method for typing KIRs using genomic DNA, we compared KIR frequencies in three ethnic populations drawn from UK blood donors. We found a significantly lower frequency of the inhibitory KIRs KIR2DS1 and 3DS1 in Afro‐Caribbean blood donors. Despite this, there was a (non‐significant) increase in the B haplotype in Afro‐Caribbean and Indian Asian donors. Some donors from each group tested negative for all non‐inhibitory KIRs. In addition, we describe several new KIR profiles. Analysis of linkage disequilibrium was consistent with previously published findings.
The HLA‐DRB, ‐DQB polymorphism and anti‐insulin antibody response in Slovenian patients with type 1 diabetes
Authors: Battelino T. , Uršič‐Bratina N. , Dolžan V. , Stopar‐Obreza M. , Pozzilli P. , Kržišnik C. , Vidan‐Jeras B.
Published: June 2003

A combination of specific HLA class II antigens and the presence of type 1 diabetes (T1D)‐related antibodies has a high positive predictive value for T1D but low sensitivity. The aim of the present study was to determine the frequencies of HLA‐DRB‐DQB deduced haplotypes associated with susceptibility and protection in Slovenian patients with established T1D, to evaluate the relationship between the HLA‐DRB1‐QBP‐DQB1 haplotypes and the presence of insulin autoantibodies (IAA) and glutamic acid decarboxylase antibodies (GADA), and to access the possible impact of polymorphic QBP promoters on this relationship. A cohort of 135 patients with T1D (age 17.5 ± 7.0 years, duration of T1D 9.14 ± 6.3 years) was investigated. HLA‐DRB1 and DQB1 alleles were typed using the polymerase chain reaction (PCR)–reverse line blot method. QBP promoter region alleles were determined using PCR–sequence‐specific oligonucleotide hybridization (SSO) and PCR–sequence‐specific primers (SSP). IAA and GADA antibodies were determined by enzyme‐linked immunosorbent assay (ELISA). The chi‐square test with Yates’ correction was used for statistical analysis. Deduced haplotypes DRB1*0301‐DQB1*0201 (P = 0.0001, OR = 3.4), DRB1*0401‐DQB1*0302 (P = 0.0001, OR = 29.8), and DRB1*0402‐DQB1*0302 (P = 0.008, OR = 4.7) were significantly more common, and DRB1*1501‐DQB1*0602 (P = 0.0001, OR = 0.03) significantly less common in the investigated cohort than in a Slovenian control group. The highest risk and the strongest protective HLA‐DR‐DQ haplotypes found in Slovenian patients with T1D did not differ from those found in other Caucasian populations. While the DRB1*0301‐QBP2.1‐DQB1*0201 haplotype, where QBP2.1 did not help to further distinguish DQB1*0201‐possessing haplotypes in IAA‐positive and IAA‐negative patients, was strongly associated with the presence of IAA, the DRB1*0101‐QBP5.12‐DQB1*0501 haplotype, although not protective compared to the control population, was associated with an absence of IAA in the investigated cohort. It is suggested that there may be a combined influence of the QBP5.12 promoter and the DQB1*0501 functional molecule on reduced IAA production.
Secretion of matrix metalloproteinase‐9 by the proinflammatory cytokine, IL‐1β: a role for the dual signalling pathways, Akt and Erk
Authors: Ruhul Amin A. R. M. , Senga Takeshi , Oo Myat Lin , Thant Aye Aye , Hamaguchi Michinari
Published: June 2003

Background: Matrix metalloproteinases including MMP‐9 mediate matrix destruction during chronic inflammatory diseases such as arthritis and atherosclerosis. MMP‐9 up‐regulation by inflammatory cytokines involve interactions between several transcription factors including activator protein‐1 and NFκB. The upstream regulatory pathways are less well understood.

Results: To search for the mechanism of tissue destruction in the process of inflammatory disorders, we investigated the signalling pathway critical for the activation of MMP‐9 expression and secretion by IL‐1β. Treatment of Balb 3T3 cells with IL‐1β activated MMP‐9 transcription and subsequent secretion in a time‐ and dose‐dependent manner. Concomitantly, IL‐1β treatment of cells activated phosphorylation of Akt, Erk and p38. Treatment of cells with either LY294002, a PI3K inhibitor, or expression of a dominant negative form of Akt drastically suppressed the IL‐1β‐dependent secretion of MMP‐9. Pretreatment of cells with a MEK1 inhibitor, U0126, also strongly inhibited IL‐1β‐dependent secretion of MMP‐9. In contrast, pre‐treatment with a specific p38 kinase inhibitor, SB203580, had no effect on IL‐1β‐dependent secretion of MMP‐9. In addition, cells expressing constitutively active form of Akt or MEK1 showed no clear activation of MMP‐9 secretion, whereas these cells responded well to IL‐1β treatment. However, co‐transfection of cells with both active Akt and MEK1 was sufficient to induce MMP‐9 secretion without stimulation with IL‐1β.

Conclusion: Taken together, our results suggest that IL‐1β stimulation of cells activates MMP‐9 secretion by the activation of the dual signalling pathways, the PI3K‐Akt and MEK1‐Erk and constitutive activation of these pathways were sufficient to induce MMP‐9 secretion.
Terminal deoxynucleotidyltransferase forms a ternary complex with a novel chromatin remodeling protein with 82 kDa and core histone
Authors: Fujita Kiyoko , Shimazaki Noriko , Ohta Yuko , Kubota Takashi , Ibe Shirou , Toji Shingo , Tamai Katsuyuki , Fujisaki Seiichiro , Hayano Takahide , Koiwai Osamu
Published: June 2003

Background: Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase that enhances the Ig and TcR gene diversity in the N region at the junctions of variable (V), diversity (D) and joining (J) segments in B‐ and T‐cells. TdT synthesizes the N region in concert with many proteins including DNA‐PKcs, Ku70 and Ku86. To elucidate the molecular mechanism of the N region synthesis, we first attempted to isolate the genes with products that directly interact with TdT.

Results: Using a yeast two‐hybrid system, we isolated a cDNA clone encoding a novel nuclear protein that interacts with TdT. This protein was designated as TdT interacting factor 2 (TdIF2). The confined region of the C‐terminal in TdIF2 is involved in specific interaction with the entire C‐terminal in TdT. TdIF2 contains an acidic region comprised of 42 residues. TdIF2 was shown to bind specifically to a core histone by pull down assay using specific antibodies against TdIF2. When a TdT/TdIF2 complex was applied on to a DNA‐cellulose column, only TdT bound to the column while TdIF2 passed through. TdIF2 reduces the TdT activity to 46% of its maximum value in vitro assay system using activated DNA as primer.

Conclusions: TdIF2 binds directly to TdT and core histone. Furthermore, TdT, TdIF2 and core histone form a ternary complex. TdIF2 liberates H2A/H2B from a core histone in correlation with PCNA. The enzymatic consequence of the TdIF2/TdT complex is the reduction of TdT activity in vitro. TdIF2 would function as a chromatin remodeling protein at the N region synthesis.
Soil N dynamics in relation to leaf litter quality and soil fertility in north‐western Patagonian forests
Authors: Satti Patricia , Mazzarino Maria Julia , Gobbi Miriam , Funes Florencia , Roselli Lucia , Fernandez Horacio
Published: June 2003

We examined the relationships among soil N dynamics, soil chemistry and leaf litter quality in 28 forest stands dominated by conifers, woody broad‐leaf deciduous species or broad‐leaf evergreens. Potential net N mineralization, net nitrification and microbial biomass N were used as indicators of soil N dynamics; pH, organic C, total N, exchangeable cations and extractable P as indicators of soil chemistry and N concentration, lignin concentration, C : N ratio and lignin : N ratio in senescent leaves as indicators of leaf litter quality. N dynamics were assessed in two consecutive years with contrasting precipitation.

Net N mineralization was lower in stands of the three conifers and one of three broad‐leaf evergreen species than in stands of the other six broad‐leaf species (40–77 vs. 87–250 mg N kg−1after 16‐week incubations) and higher in the wetter year.

The proportion of N nitrified was high beneath most species regardless of mineralization rates, soil N fertility and leaf litter quality, and was significantly higher for the wetter year. Ammonium was the predominant form of N in three sites affected by seasonal waterlogging and in two sites the predominant form changed from ammonium in the drier year to nitrate during the wetter year, probably due to differences in soil texture affecting soil moisture.

Net N mineralization was linearly related to microbial biomass N, implying that the microbial activity per biomass unit was quite similar beneath all species. Constant microbial biomass during the wetter year suggested that as mineralization/nitrification increased, there was a higher potential risk of N losses.

Although the litter lignin : N ratio allowed differentiation of soil N dynamics between broad‐leaf species and conifers, its constant value (23–28) in all broad‐leaf species made it a poor predictor of the differences found within this group. Across all sites and between broad‐leaf species, soil N dynamics were best explained by a combination of leaf litter lignin and soil chemistry indicators, particularly soil total N for net N mineralization and net nitrification, and soil organic C for microbial biomass N.
Spatial and temporal variation of biomass in a tropical forest: results from a large census plot in Panama
Authors: Chave Jérôme , Condit Richard , Lao Suzanne , Caspersen John P. , Foster Robin B. , Hubbell Stephen P.
Published: June 2003

We estimated the dry, living, above‐ground biomass (AGB) standing stock and its turnover in a 50‐hectare forest plot located in moist tropical forest on Barro Colorado Island, Panama. The estimates were obtained using inventory data collected every 5 years from 1985 to 2000, including measurements of all trees ≥ 1 cm diameter.

Four different allometric regressions relating trunk diameter and height with AGB were compared. Based on the most consistent method, we estimated that the Barro Colorado forest holds 281 ± 20 Mg ha−1(1 Mg = 103kg) of AGB, lianas included. A third of the AGB is stored in trees larger than 70 cm in diameter.

Stand‐level AGB increment (growth plus recruitment) was highest in the period 1985–90 (7.05 ± 0.32 Mg ha−1 year−1, mean ± 95% confidence limits based on samples of multiple hectares) and smallest in the period 1990–95 (5.25 ± 0.26 Mg ha−1 year−1), while AGB losses were similar during the three intervals (mean 5.43 ± 0.72 Mg ha−1year−1). This resulted in significant differences in AGB change (defined as increment minus loss) among census intervals; including branchfalls, the AGB of Barro Colorado Island increased in 1985–90 (+0.82 ± 0.84 Mg ha−1 year−1), decreased in 1990–95 (−0.69 ± 0.82 Mg ha−1 year−1), and increased again in 1995–2000 (+0.45 ± 0.70 Mg ha−1year−1). The 15‐year average was +0.20 Mg ha−1 year−1, but with a confidence interval that spanned zero (−0.68 to 0.63 Mg ha−1 year−1).

Branchfalls and partial breakage of stems had a significant influence on the AGB changes. They contributed an average of 0.46 Mg ha−1 year−1to the AGB loss. About 5% of AGB increment was due to trees less than 10 cm in diameter.

To test whether the AGB of tropical forests is increasing due to climate change, we propose that in each forest type, at least 10 hectares of forest be inventoried, and that measurements of the small classes (< 10 cm diameter) as well as large size classes be included. Biomass loss due to crown damage should also be estimated.
Temporal heterogeneity of soil moisture in grassland and forest
Authors: James Sarah E. , Pärtel Meelis , Wilson Scott D. , Peltzer Duane A.
Published: June 2003

Differences between growth forms in the spatial heterogeneity of associated soil resources, such as water, are well‐documented. We tested for differences in the temporal heterogeneity of soil moisture between natural grassland, shrubland and Populus tremuloides forest at the northern edge of the Great Plains.

Weekly measurements of soil moisture over a year, and daily measurements during a growing season, both showed significant interactions between habitat and time. Soils under grassland and shrubs were wettest at the start of the growing season but driest at the end.

The coefficient of variation of soil moisture content over time during the growing season was significantly higher in grassland than in forest. Similar results were found for whole‐year measurements, and at two depths beneath the soil surface (10 and 30 cm).

We found little interception of rainfall in any vegetation type. The net effect of vegetation on soil moisture during a drying period, however, was significantly greater in grassland than in forest, suggesting that differences in the temporal heterogeneity of soil moisture content are related to resource uptake.