bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF GRAFT NEPHRECTOMY AND HLA TYPING ON LONG‐TERM GRAFT FUNCTION AND SURVIVAL IN KIDNEY RETRANSPLANTATION
Authors: Karakayalý H , Yağmurdur MC , Moray G , Tezel E , Emiroğlu R , Haberal M
Published: March 2003

In this study, we retrospectively evaluated our long‐term results of the recipients who received a second allograft. Between 3 November 1975 and 31 December 2001, our transplantation team performed 1365 kidney transplantations. Fifty (3.6%) of these patients underwent retransplantations. Forty‐seven received their second transplantation and the remaining three received their third transplantation. The same low‐dose triple drug immunosuppression protocol with prednisolone, azathioprine and cyclosporine A was used in both groups. There were two study groups: the patients in Group 1 (n=19) underwent allograft nephrectomy, while those in Group 2 (n=31) did not. Demographic properties, rejection rates throughout the follow up period, serum creatinine levels within 12 months, graft and patient survival rates, postoperative complications, time interval between the transplantations, and HLA matchings were studied. For statistical analysis the Student's t and Kaplan–Meier tests were used, and P‐values <0.05 were accepted as significant.

Forty‐one patients who underwent re‐transplantation received kidney from living related donors and remaining 9 patients from cadaveric donors. Mean interval between first and second transplantations was 50 months (range, 1–192 months). Mean blood creatinine levels was 1.8 mg/dL (range, 0.8–6.5 mg/dL). HLA‐AB and HLA‐DR mismatches were 1.92±1.1 and 0.9±0.7, respectively.

Acute rejection rates were significantly different between Group 1(9/19,47%) and Group 2(12/31,38%) (P=0.03). Graft loss was found to be lower in Group 1 (6/19, 32%) than that in Group 2 (11/31 35%), though these values were not statistically different (P>0.05). The average interval between first and second transplantations was 32,1±21 months in Group 2 and 61,5±46 months in Group 1 (P=0.018). The duration of hemodialysis before second transplantation were 17±9 months in Group 2 and 27±11 months in Group 1 (P=0.04). One, 3 and 5 years graft survival rates (Group 2 vs. Group 1) were 89% vs. 83%, 79% vs. 64% and 68% vs. 45%, respectively (P<0.05). Also, the interval between first and second transplantations may have a negative correlation with second graft survival In conclusion, there appears to be no advantage associated with graft nephrectomy before re‐transplantations and longer duration of hemodialysis may decrease graft survival rates.
Identification of sequence errors in HLA‐DRB1*0801 and HLA‐DRB1*12011
Authors: Greville W.D. , Dunckley H.
Published: March 2003

Abstract: We report the identification of previously unrecognised errors in the nucleotide sequences of two long established HLA‐DRB1 alleles, DRB1*0801 and DRB1*12011. The errors were detected during development of sequencing based typing (SBT) methods for the HLA‐DRB1 locus and were confirmed by sequencing cell lines from the 10th International Histocompatibility Workshop (IHW).
HLA Class II peptide‐binding and autoimmunity
Authors: Gebe J.A. , Swanson E. , Kwok W.W.
Published: March 2003

Abstract: The HLA class II locus is located in the 6p21.3 region on the short arm of chromosome 6 and encompasses approximately 700 kb. It consists of over 30 gene loci including the major class II structural genes DP, DQ and DR. While autoimmune disease correlates to specific DP, DQ or DR alleles have been documented, due to the strong linkage disequilibrium between the different HLA alleles, especially between the DR and DQ, the precise identification of susceptible MHC alleles for a number of autoimmune diseases remains elusive.
Novel HLA‐DRB1 alleles discovered during routine sequencing based typing, DRB1*03052, DRB1*04032, DRB1*1139 and DRB1*1346
Authors: Greville W.D. , Chapman G. , Hogbin J‐P. , Kennedy A. , Dunckley H.
Published: March 2003

Abstract: We report the discovery of four HLA‐DRB1 alleles during routine sequencing based typing (SBT). These alleles – DRB1*03052, DRB1*04032, DRB1*1139 and DRB1*1346 – differ from previously identified DRB1 alleles by known nucleotide polymorphisms.
Identification of a new HLA‐B allele, B*3705 containing a Bw6 sequence motif
Authors: Pyo C.‐W. , Han H. , Kim T.‐G.
Published: March 2003

Abstract: HLA‐B37, which is Bw4 type antigen frequently found in linkage disequilibrium with A1, Cw6 and DR10 in all ethnic groups, generally has a very low frequency all over the world. We report a new HLA‐B*37 allele, B*3705, identified in two potential bone marrow donors in the Korean population. B*3705, which has the Bw6 nucleotide segment, differs from B*3701 in three nucleotide positions: 311, 317 and 319 in exon2. The serological profile of B*3705 did not exhibit the B37 specificity. The putative haplotype associated with B*3705 in the Korean population could be A*02‐Cw*0602‐DRB1*1001‐DQA1*0101‐DQB1*0501‐DPB1*02011.
Identification of a new HLA‐B null allele, B*1817 N, in a family
Authors: DenHollander N. , Li J. , Van Oosterwijk A. , Ng C.‐M. , Singal D.P.
Published: March 2003

Abstract: We describe a new HLA‐B null allele found in a daughter and her mother. This null allele was due to a mutation at position 41 of exon 1 which resulted in a premature stop codon. This new null allele was officially named HLA‐B*1817N*.
Identification of HLA‐B*1566
Authors: Cox S.T. , Prokupek B. , Baker F. , Holman R. , Leung V.T.C. , Wong A.S.W. , Madrigal J. A. , Little A.‐M.
Published: March 2003

Abstract: A novel polymorphism was identified in a B*15 allele. B*1566 possesses a nucleotide substitution of C to G at nucleotide 272. This polymorphism encodes an amino acid difference from serine in B*1501101 to cysteine in B*1566 at residue 67. Residue 67 is a constituent of the B pocket and is situated on the α1 helix facing into the groove. This mutation may have arisen through interallelic recombination as it has been seen in other B*15 alleles and is also present in most B*14, B*27, B*38, B*39 alleles and in B*7301.
HLA‐DR and DQB1 gene polymorphism in the North‐western Colombian population
Authors: Correa P.A. , Whitworth W.C. , Kuffner T. , McNicholl J. , Anaya J‐M.
Published: March 2003

Abstract: HLA‐DRB1, DRB3, DRB4, DRB5 and DQB1 polymorphisms were studied using molecular methods in a population of 100 unrelated healthy individuals from an area in north‐west Colombia (Medellin) inhabited by the “Paisa”, a community with features of a genetically isolated group. The most frequently observed specificities at the DRB1 locus were *07 (16.4%) and *15 (12%), and at the DQB1 locus *02 (18.8%) and *03 (33.6%), of which *0302 was the most prevalent allele (14.3%). The most polymorphic specificities were DRB1*04, 13 and 11, and DQB1*06. Both the HLA‐DRB1 and DQB1 loci were in linkage disequilibrium. Haplotypes were estimated using maximum likelihood methods. The most frequent two locus haplotype was DRB1*07‐DQB1*02 (6.6%) and these specificities were in linkage disequilibrium. Several unusual possible haplotypes were observed. Both the HLA‐DRB1 and DQB1 locus were in Hardy–Weinberg equilibrium.
A novel HLA‐DQA1 allele, DQA1*01042
Authors: Pérez‐Rodríguez M. , Madrigal J.A. , Marsh S.G.E.
Published: March 2003

Abstract: We have identified a novel HLA‐DQA1 allele in the homozygous cell line KGV (I HW9309) derived from a Caucasoid individual from the Indian subcontinent. This novel allele, DQA1*01042, differs from the DQA1*01041 allele by a single synonymous substituition within exon 3, position 438A→C.1
Susceptibility locus for non‐obstructive azoospermia is localized within the HLA‐DR/DQ subregion: Primary role of DQB1*0604
Authors: Matsuzaka Y. , Makino S. , Okamoto K. , Oka A. , Tsujimura A. , Matsumiya K. , Takahara S. , Okuyama A. , Sada M. , Gotoh R. , Nakatani T. , Ota M. , Katsuyama Y. , Tamiya G. , Inoko H.
Published: March 2003

Abstract: Non‐obstructive azoospermia is a male infertility characterized by no or little sperm in semen as a result of a congenital dysfunction in spermatogenesis. Previous studies have reported a higher prevalence of particular human leukocyte antigen (HLA) antigens in non‐obstructive azoospermia. As the expression of the RING3 gene located in the HLA class II region was predominant in the testis, mainly around spermatids and pachytene spermatocytes, it is tempting to speculate that RING3 is one of the strong candidate genes responsible for the pathogenesis of the disease. In this study, the genetic polymorphism in the RING3 gene was investigated by the direct sequencing technique. As a result, a total of 14 single nucleotide polymorphisms were identified. Among them, six were localized in the coding region but none of them was accompanied by an amino‐acid substitution. No significant difference in the allelic distribution at these 14 polymorphic sites was observed between the patients and healthy controls, suggesting that the susceptible gene for non‐obstructive azoospermia is not the RING3 gene. Then, in order to map the susceptibility locus for non‐obstructive azoospermia precisely within the HLA region, 11 polymorphic microsatellite markers distributed from the SACM2L gene just outside the HLA class II region (187 kb telomeric of the DPB1 gene) to the OTF3 gene in the HLA class I region were subjected to association analysis in the patients. Statistical analysis of distribution in the allelic frequency at each microsatellite locus demonstrated that the pathogenic gene for non‐obstructive azoospermia is located within the HLA‐DR/DQ subregion. In fact, DRB1*1302 and DQB1*0604 were found to be strongly associated with non‐obstructive azoospermia by polymerase chain reaction‐based DNA typing. Further, haplotype analysis suggested that the DQB1*0604 allele may play a decisive role in the pathogenesis of non‐obstructive azoospermia.
HLA in coeliac disease families: A novel test of risk modification by the ‘other’ haplotype when at least one DQA1*05‐DQB1*02 haplotype is carried
Authors: Louka A.S. , Nilsson S. , Olsson M. , Talseth B. , Lie B.A. , Ek J. , Gudjónsdóttir A.H. , Ascher H. , Sollid L.M.
Published: March 2003

Abstract: Predisposition to coeliac disease (CD) involves HLA genes. We investigated whether any haplotypes modify risk when carried trans to a known high‐risk haplotype, DQA1*05‐DQB1*02. Earlier attempts to rank levels of risk contributed by the ‘other’ haplotype were burdened by use of case‐control populations; haplotype frequencies were estimated and homozygosity was only presumed. In contrast, exact haplotypes can be determined and allele transmission can be traced in families. A similar study in narcolepsy reported strata of different degrees of predisposition, attributable to the ‘other’ haplotype. A gene dosage effect similar to that described for DQB1*02 in CD, has also been reported in narcolepsy. We genotyped 439 simplex/multiplex trios for DQA1 and DQB1. We designed a new statistic to test risk modulation by the trans haplotype, even if the affected offspring was homozygous. We tested for significant deviation in transmission of the ‘other’ haplotype, i.e., modification of DQA1*05‐DQB1*02 risk. We also addressed the proposed difference in risk, between DQA1*05‐DQB1*02 homozygotes and DQA1*05‐DQB1*02/DQA1*0201‐DQB1*02 heterozygotes, reported in Southern Europe. We confirmed a DQB1*02 gene dosage effect. However, no haplotypes were found to modify risk when carried trans to DQA1*05‐DQB1*02, except DQA1*05‐DQB1*02 and DQA1*0201‐DQB1*02 which were already known. We did not find credible evidence for a difference in risk conferred by DQA1*05‐DQB1*02 and DQA1*0201‐DQB1*02, when carried with DQA1*05‐DQB1*02. The new test, which directly inspects haplotype transmissions rather than estimated haplotype frequencies, was used to demonstrate that the ‘other’ haplotype (except DQA1*05‐DQB1*02 and DQA1*0201‐DQB1*02) does not modify risk conferred by DQA1*05‐DQB1*02. The test is applicable to other diseases.
HLA‐B27 and the pathogenesis of spondyloarthritis
Authors: Ramos M. , De Castro J. A. López
Published: March 2003

Abstract: The association of HLA‐B27 with ankylosing spondylitis and other spondyloarthropathies ranks among the strongest between any HLA antigen and a human disease. Yet, in spite of intense research and advanced knowledge of the biochemistry and biology of major histocompatibility complex molecules, the mechanism of this association remains unknown. This review attempts a critical assessment of current pathogenetic hypotheses from evidence concerning the epidemiology of HLA–B27 association with disease, its peptide‐binding specificity, and other aspects of the molecular biology and immunology of this molecule.
Comprehensive hereditary hemochromatosis genotyping
Authors: Jones D. C. , Young N. T. , Pigott C. , Fuggle S. V. , Barnardo M. C. N. M. , Marshall S. E. , Bunce M.
Published: March 2003

Abstract: Hereditary hemochromatosis (HH) is an iron‐overload disease common in populations of Northern European origin. Patients display increased iron absorption leading to excessive iron deposition and potential multiorgan failure. Using polymerase chain reaction sequence‐specific primer (PCR‐SSP) technology, we have developed an HH diagnosis assay capable of detecting 19 non‐synonymous HFE mutations (including a previously unreported mutation, V295A) and several TFR2, SLC11A3 and H ferritin alleles implicated in HH. As part of the validation process, 159 UK renal donors were genotyped to determine HH allele frequencies in the UK population. The alleles nominally identified as HFE*01 (C282Y), HFE*02 (H63D) and HFE*03 (S65C) were found at frequencies of 0.085, 0.173 and 0.009, respectively. All other potential HH‐associated alleles were absent, confirming their low prevalence in this population. This assay enables comprehensive routine HH genotyping, producing rapid, accurate and reproducible results at low cost.
A new allele within the transmembrane region of the human MICA gene with seven GCT repeats
Authors: Rueda B. , Pascual M. , López‐Nevot M.A. , González E. , Martín J.
Published: March 2003

Abstract: Major histocompatibility complex class I chain‐related genes (MIC) belong to a multicopy gene family located within the HLA class I region of chromosome 6. They encode for proteins that have a completely different organization, expression, and products from classical HLA class I gene products. One member of this family is the MICA gene, which is characterized by its high degree of polymorphism, with over 50 MICA alleles described. Moreover, MICA exon 5 presents a microsatellite polymorphism consisting of a variable number of GCT repeats that encode for 4, 5, 6, 9, or 10 alanine residues, and a variant (MICA A5.1) that includes a nucleotide insertion (GCT→GGCT). In this study, we report a novel allele in the transmembrane region of the MICA gene consisting of seven GCT repeats found in a family based study of MICA polymorphism in celiac disease.
Chemical synthesis and structure–activity relationships of Ts κ, a novel scorpion toxin acting on apamin‐sensitive SK channel
Authors: Lecomte C. , Ferrat G. , Fajloun Z. , Van Rietschoten J. , Rochat H. , Martin‐Eauclaire M.‐F. , Darbon H. , Sabatier J.‐M.
Published: March 2003

Abstract: Tityus kappa (Ts κ), a novel toxin from the venom of the scorpion Tityus serrulatus, is a 35‐residue polypeptide cross‐linked by three disulphide bridges and acts on small‐conductance calcium‐activated potassium channels (SK channels). Ts κ was chemically synthesized using the solid‐phase method and characterized. The synthetic product, sTs κ, was indistinguishable from the natural toxin when tested in vitro in competition assay with radiolabelled apamin for binding to rat brain synaptosomes (IC50 = 3 nm). The sTs κ was further tested in vivo for lethal activity to mice following intracerebroventricular inoculation (LD50 = 70 ng per mouse). The half‐cystine pairings were formerly established by enzyme‐based cleavage of sTs κ; they were between Cys7–Cys28, Cys13–Cys33 and Cys17–Cys35, which is a disulphide bridge pattern similar to that of other short scorpion toxins. According to previous studies on SK channel‐acting toxins, the putative influence of certain basic residues of Ts κ (i.e. Arg6, Arg9, Lys18, Lys19) in its pharmacological activity was investigated using synthetic point‐mutated analogues of the toxin with an Ala substitution at these positions. Data from binding assay, together with conformational analysis of the synthetic analogues by 1H‐NMR, suggest that Arg6, and to a lesser extent Arg9, are important residues for an high‐affinity interaction of this toxin with SK channels; interestingly these residues are located outside the α‐helical structure, whereas the pharmacologically important basic residues from other SK channel‐specific toxins had been located inside the α‐helix.
Isolation of mitogenically active C‐terminal truncated pentapeptide of osteogenic growth peptide from human plasma and culture medium of murine osteoblastic cells
Authors: Bab I. , Gavish H. , Namdar‐Attar M. , Greenberg Z. , Chen Y. , Mansur N. , Muhlrad A. , Shteyer A. , Chorev M.
Published: March 2003

Abstract: The osteogenic growth peptide (OGP) is a 14‐amino acid stromal cell mitogen that stimulates in vivo osteogenesis and hematopoiesis. In the blood circulation and cell culture conditioned medium immunoreactive OGP (irOGP), identified using antibodies raised against the OGP C‐terminal region, presents free and bound forms. The bound form consists entirely of the full length peptide. The present study was designed to investigate the identity of free irOGP under nondenaturing conditions. Fresh human serum and culture medium conditioned with murine osteoblastic MC3T3 E1 cells were fractionated using ultrafiltration (3000 molecular weight cut‐off). Hydrophobic chromatography of the ultrafiltrate, immunoscreening of chromatographic fractions with antibodies directed against the OGP C‐terminal region and amino acid sequencing of immunoreactive peaks demonstrated the presence of two mitogens, the full length OGP and a C‐terminal truncated form, OGP(10–14). The OGP(10–14) derived from both serum and conditioned medium, as well as the synthetic pentapeptide [sOGP(10–14)], shared the in vitro OGP proliferative activity. However, in a competitive binding assay, devised to assess the OGP–OGP binding protein (OGPBP) complex formation, sOGP(10–14) failed to compete out radiolabeled OGP from the complex. It is concluded that OGP(10–14) is a naturally occuring human and murine mitogen. In addition, the data suggests that the OGP(10–14) is generated from OGP by proteolytic cleavage upon dissociation of the OGP–OGPBP complexes.
Gramicidin S: a peptide model for protein glycation and reversal of glycation using nucleophilic amines
Authors: Shakkottai V G , Sudha R , Balaram P
Published: March 2003

Abstract: Nonenzymatic glycation of proteins has been implicated in various diabetic complications and age‐related disorders. Proteins undergo glycation at the N‐terminus or at the ε‐amino group of lysine residues. Glycation of proteins proceeds through the stages of Schiff base formation, conversion to ketoamine product and advanced glycation end products. Gramicidin S, which has two ornithine residues, was used as a model system to study the various stages of glycation of proteins using electrospray ionization mass spectrometry. The proximity of two ornithine residues in the peptide favors the glycation reaction. Formation of advanced glycation end products and diglycation on ornithine residues in gramicidin S were observed. The formation of Schiff base adduct is reversible, whereas the Amadori rearrangement to the ketoamine product is irreversible. Nucleophilic amines and hydrazines can deglycate the Schiff base adduct of glucose with peptides and proteins. Hydroxylamine, isonicotinic acid hydrazide and aminoguanidine effectively removed glucose from the Schiff base adduct of gramicidin S. Hydroxylamine is more effective in deglycating the adduct compared with isonicotinic acid hydrazide and aminoguanidine. The observation that the hydrazines are effective in deglycating the Schiff base adduct even in the presence of high concentrations of glucose, may have a possible therapeutic application in preventing complications of diabetes mellitus. Hydrazines may be used to distinguish between the Schiff base and the ketoamine products formed at the initial stages of glycation.
Aib‐based peptide backbone as scaffolds for helical peptide mimics
Authors: Banerjee Raja , Basu Gautam , Roy Siddhartha , Chène Patrick
Published: March 2003

Abstract:Helical peptides that can intervene and disrupt therapeutically important protein–protein interactions are attractive drug targets. In order to develop a general strategy for developing such helical peptide mimics, we have studied the effect of incorporating α‐amino isobutyric acid (Aib), an amino acid with strong preference for helical backbone, as the sole helix promoter in designed peptides. Specifically, we focus on the hdm2–p53 interaction, which is central to development of many types of cancer. The peptide corresponding to the hdm2 interacting part of p53, helical in bound state but devoid of structure in solution, served as the starting point for peptide design that involved replacement of noninteracting residues by Aib. Incorporation of Aib, while preserving the interacting residues, led to significant increase in helical structure, particularly at theC‐terminal region as judged by nuclear magnetic resonance and circular dichroism. The interaction with hdm2 was also found to be enhanced. Most interestingly, trypsin cleavage was found to be retarded by several orders of magnitude. We conclude that incorporation of Aib is a feasible strategy to create peptide helical mimics with enhanced receptor binding and lower protease cleavage rate.
Conformation and interaction of the cyclic cationic antimicrobial peptides in lipid bilayers
Authors: Jelokhani‐Niaraki M. , Prenner E.J. , Kay C.M. , McElhaney R.N. , Hodges R.S.
Published: March 2003

Abstract: To investigate the role of peptide–membrane interactions in the biological activity of cyclic cationic peptides, the conformations and interactions of four membrane‐active antimicrobial peptides [based on Gramicidin S (GS)] were examined in neutral and negatively charged micelles and phospholipid vesicles, using CD and fluorescence spectroscopy and ultracentrifugation techniques. Moreover, the effects of these peptides on the release of entrapped fluorescent dye from unilamellar vesicles of phosphatidylcholine (PC) and phosphatidylethanolamine/phosphatidylglycerol (PE/PG) were studied. The cyclic peptides include GS10 [Cyclo(VKLdYP)2], GS12 [Cyclo(VKLKdYPKVKLdYP)], GS14 [Cyclo(VKLKVdYPLKVKLdYP)] and [d‐Lys]4GS14 [Cyclo(VKLdKVdYPLKVKLdYP)] (underlined residues are d‐amino acids), were different in their ring size, structure and amphipathicity, and covered a broad spectrum of hemolytic and antimicrobial activities. Interaction of the peptides with the zwitterionic PC and negatively charged PE/PG vesicles were distinct from each other. The hydrophobic interaction seems to be the dominant factor in the hemolytic activity of the peptides, as well as their interaction with the PC vesicles. A combination of electrostatic and hydrophobic interactions of the peptides induces aggregation and fusion in PE/PG vesicles with different propensities in the order: [d‐Lys]4GS14 > GS14 > GS12 > GS10. GS10 and GS14 are apparently located in the deeper levels of the membrane interfaces and closer to the hydrophobic core of the bilayers, whereas GS12 and [d‐Lys]4GS14 reside closer to the outer boundary of the interface. Because of differing modes of interaction of the cyclic cationic peptides with lipid bilayers, the mechanism of their biological activity (and its relation to peptide–lipid interaction) proved to be versatile and complex, and dependent on the biophysical properties of both the peptides and membranes.
Binding of agonists, antagonists and inverse agonists to the human δ‐opioid receptor produces distinctly different conformational states distinguishable by plasmon‐waveguide resonance spectroscopy
Authors: Salamon Z. , Hruby V. J. , Tollin G. , Cowell S.
Published: March 2003

Abstract: Structural changes induced by the binding of agonists, antagonists and inverse agonists to the cloned δ‐opioid receptor from human brain immobilized in a solid‐supported lipid bilayer were monitored using plasmon‐waveguide resonance (PWR) spectroscopy. Agonist (e.g. deltorphin II) binding causes an increase in membrane thickness because of receptor elongation, a mass density increase due to an influx of lipid molecules into the bilayer, and an increase in refractive index anisotropy due to transmembrane helix and fatty acyl chain ordering. In contrast, antagonist (e.g. TIPPpsi) binding produces no measurable change in either membrane thickness or mass density, and a significantly larger increase in refractive index anisotropy, the latter thought to be due to a greater extent of helix and acyl chain ordering within the membrane interior. These results are closely similar to those reported earlier for another agonist (DPDPE) and antagonist (naltrindol) [Salamon et al. (2000) Biophys. J.79, 2463–2474]. In addition, we now find that an inverse agonist (TMT‐Tic) produces membrane thickness, mass density and refractive index anisotropy increases which are similar to, but considerably smaller than, those generated by agonists. Thus, a third conformational state is produced by this ligand, different from those formed by agonists and antagonists. These results shed new light on the mechanisms of ligand‐induced G‐protein‐coupled receptor functioning. The potential utilization of this new biophysical method to examine structural changes both parallel and perpendicular to the membrane normal for GPCRs is emphasized.
Diversity of oral asaccharolytic Eubacterium species in periodontitis – identification of novel phylotypes representing uncultivated taxa
Authors: Spratt D. A. , Weightman A. J. , Wade W. G.
Published: March 2003

Oral asaccharolytic Eubacterium species are associated with periodontal disease and other oral infections. The aim of this study was to use a culture‐independent molecular technique to determine the diversity of asaccharolytic Eubacterium species in subgingival plaque in periodontitis. An oligonucleotide PCR primer designed to amplify 16S rRNA genes of the oral asaccharolytic Eubacterium branch of the phylogenetic tree was constructed. This primer was used together with a universal primer in PCRs to amplify gene sequences directly from a single subgingival plaque sample. Fifty PCR products were purified by cloning, fully sequenced and subjected to molecular phylogenetic analysis. The sequences were assigned to four groups within a single lineage of the low G+C gram‐positive bacteria. Group I (58% of the cloned sequences) was assigned to a branch that included Eubacterium nodatum, and Group II (22%) to a branch including Eubacterium infirmum. Group III (8%) was distinct from but related to E. infirmum at the species level, and Group IV (12%) was another novel taxon more distantly related to E. infirmum and E. nodatum.
Evidence for apoptosis of the majority of T cells activated in vitro with Actinobacillus actinomycetemcomitans
Authors: Nalbant A. , Zadeh H. H.
Published: March 2003

Our previous studies had demonstrated that nearly half of all T cells stimulated with Actinobacillus actinomycetemcomitans are activated within a few hours. However, it was not known whether all of these T cells survive. The aim of the present study was to determine whether the T cells activated in response to A. actinomycetemcomitans undergo apoptosis. To that end, peripheral blood mononuclear cells were cultured at different time points in the presence of A. actinomycetemcomitans. Flow cytometric analysis demonstrated that, following exposure to a preparation of A. actinomycetemcomitans, T cells progressively externalized their plasma membrane phosphatidylserine, as measured by annexin V binding. Approximately half of all T cells bound annexin V by 96 h. During this period, Annexin V–positive T cells also incorporated propidium iodide suggesting loss of membrane integrity. The externalization of phosphatidylserine occurred at a higher rate among activated (CD69+) T cells, where roughly two‐thirds became Annexin V–positive. Flow cytometric analysis also demonstrated shrinkage of the Annexin V–positive and propidium iodide–positive T cells. The data presented here provides evidence for the induction of apoptosis among the majority of the T cells responding to A. actinomycetemcomitans.
Binding of oral streptococci to human fibrinogen
Authors: Lee S. Y. , Kim K.‐K. , Choe S.‐J.
Published: March 2003

The interaction of oral streptococci with human fibrinogen was investigated. Streptococcus gordonii was chosen as a representative species to study the binding to fibrinogen. S. gordonii DL1 adhered to immobilized fibrinogen and bovine serum albumin. Binding to immobilized fibrinogen was saturable, concentration and temperature dependent. The binding of S. gordonii DL1 to fibrinogen was inhibited by anti‐fibrinogen antibody. Heating of the bacteria for 1 h at 95°C resulted in 90% inhibition of the binding. Trypsin treatment of the bacteria resulted in decreased binding. Neither lipoteichoic acid nor culturing of the bacteria in a sucrose‐supplemented medium had any effect on the binding. S. gordonii, Streptococcus sanguinis, Streptococcus mitis, and Streptococcus oralis bound to the immobilized fibrinogen, but mutans streptococci did not. None of the oral streptococci tested bound to the fibrinogen in fluid phase. These results suggest that the binding of S. gordonii DL1 to immobilized fibrinogen is mediated through a specific protein adhesin‐receptor interaction, and fibrinogen acts as a cryptitope.
Characterization of binding and utilization of hemoglobin by Prevotella nigrescens
Authors: Guan S. , Nagata H. , Kuboniwa M. , Ikawa Y. , Maeda K. , Shizukuishi S.
Published: March 2003

The ability of Prevotella nigrescens to utilize and bind to hemoglobin was investigated. Growth studies showed that P. nigrescens was able to utilize hemoglobin efficiently as an iron source. Binding of P. nigrescens to hemoglobin was demonstrated by dot blot assay. Heat and trypsin treatments of the bacteria led to a decrease in activity. Globin gave nearly complete inhibition of activity. Additionally, lactoferrin partially inhibited activity. In contrast, transferrin, cytochrome C and catalase exerted little or no inhibitory effect. Although the sugars tested did not affect activity, several of the amino acids tested, including arginine, cysteine, histidine and lysine, inhibited activity. In a solid phase assay, 41‐, 56‐ and 59‐kDa proteins of P. nigrescens reacted with hemoglobin. These results suggest that P. nigrescens utilizes hemoglobin for growth and 41‐, 56‐ and 59‐kDa proteins may be involved in hemoglobin binding.
Tracing genotypes of mutans streptococci on tooth sites by random amplified polymorphic DNA (RAPD) analysis
Authors: Redmo Emanuelsson I.‐M. , Carlsson P. , Hamberg K. , Bratthall D.
Published: March 2003

The aim of this study was to clarify the distribution and persistence of mutans streptococci on different tooth sites in the same oral cavity. Thirteen subjects, aged 20–40 years, were examined. Salivary levels of mutans streptococci, caries prevalence, oral hygiene habits and status of tooth surfaces sampled were recorded. Plaque samples were obtained from four sites, the mesial and buccal surfaces of the first permanent molar on the right side of the lower jaw (46m and 46b), the distal surface of the first permanent premolar (24d) and the mesial surface of the second permanent premolar (25m) on the left side of the upper jaw, using sterile toothpicks on two occasions at 4–7‐month intervals. The samples were cultivated on site‐specific Strip mutans. Up to 10 colonies/site were isolated when present and genotyped by random amplified polymorphic DNA (RAPD) analysis, after species identification with PCR. Genotyping was also performed by restriction endonuclease analysis (REA) on 148 isolates, and results were consistent with the RAPD results. Most mutans streptococcus‐positive samples were obtained from 46m. Within each individual, the same genotype occurred on at least two sites on all but one sampling occasion. A maximum of seven different genotypes were found in an individual. For a particular tooth site, four genotypes occurred simultaneously and taking both sampling occasions together the maximum was six different types. The same genotypes/types were found again after 4–7 months on 25 sites in 12 subjects. Fifteen sites were mutans streptococcus‐positive on only one sampling occasion. The results indicate that several different genotypes of mutans streptococci colonize a tooth site, and that the same genotype colonizes several sites in the same oral cavity. Persistence of genotypes on a site for several months and interindividual differences in the occurrence of genotypes were also found.
Interleukin‐6 and granulocyte‐macrophage colony‐stimulating factor in apical periodontitis: correlation with clinical and histologic findings of the involved teeth
Authors: Radics T. , Kiss C. , Tar I. , Márton I. J.
Published: March 2003

Apical periodontitis is characterized by the presence of immunocompetent cells producing a wide variety of inflammatory mediators. Releasing cytokines with long‐range action, such as interleukin‐6 (IL‐6) and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), apical periodontitis may induce changes in remote organs of the host. This study quantified the levels of IL‐6 and GM‐CSF in symptomatic and asymptomatic human periradicular lesions. Lesions were also characterized by size and histologic findings. Tissue samples were homogenized and supernatants were assayed using an enzyme‐linked immunosorbent assay (ELISA). Correlations between cytokine levels and characteristic features (as single variables) of the lesions were analysed. There was a trend for higher levels of IL‐6 and GM‐CSF in symptomatic than in asymptomatic lesions, but the difference was not significant. Levels also tended to be higher in large than in small lesions, in polymorphonuclear (PMN) cell‐rich than in PMN cell‐poor samples, and in epithelialized than in non‐epithelialized lesions. Significantly higher levels of IL‐6 (778.1 ± 220.5 pg/μg) and GM‐CSF (363.3 ± 98.4 pg/μg) were found in samples coincidentally possessing symptomatic and epithelialized features than in asymptomatic, small, PMN cell‐poor, non‐epithelialized lesions (IL‐6: 45.2 ± 13.1 pg/μg and GM‐CSF: 135.1 ± 26.4 pg/μg). These results suggest that symptomatic lesions containing epithelial cells represent an immunologically active stage of apical periodontitis, whereas asymptomatic, small, PMN cell‐poor, non‐epithelialized lesions represent healing apical lesions.
Food hypersensitivity in two groups of children and young adults with atopic dermatitis evaluated a decade apart
Authors: Ellman Lisa K. , Chatchatee Pantipa , Sicherer Scott H. , Sampson Hugh A.
Published: March 2003

There is an impression that children today are experiencing allergic reactions to an increasing variety of foods. We compared two separate groups of children and young adults with atopic dermatitis evaluated a decade apart and found no difference in sensitization rates or overall clinical reactivity to a variety of foods. Allergies to egg, milk, wheat, soy, peanut, tree nuts, and seafood continue to account for ≈ 90% of food‐allergic reactions over the past decade.
Time efficacy of a single dose of montelukast on exercise‐induced asthma in children
Authors: Peroni Diego G. , Piacentini Giorgio L. , Ress Michela , Bodini Alessandro , Loiacono Attilio , Aralla Raffaele , Boner Attilio L.
Published: March 2003

The aim of this study was to evaluate the timing of onset and the duration of action of a single oral‐dose treatment with montelukast in comparison to placebo on exercise‐induced asthma (EIA) in asthmatic children. Nineteen children (7–13 years) with stable asthma were evaluated. Patients undertook three consecutive treadmill exercise tests, respectively, 2, 12 and 24 h after a single‐dose administration. A double‐blind randomized, single‐dose, placebo‐controlled, crossover design was used. To assess bronchoconstriction after the exercise challenge, the maximal percentage fall in FEV1 (ΔFEV1) from the baseline value was considered. Two hours after dosing, ΔFEV1 was −15.33 ± 2.93 for placebo and −13.33 ± 2.03 for montelukast. At 12 h, ΔFEV1 was −18.69 ± 2.83 for placebo, −9.78 ± 1.85 for montelukast (p < 0.005). No difference was observed between placebo (ΔFEV1−10.21 ± 2.07) and montelukast (ΔFEV1−9.10 ± 2.02) at 24 h. Analysis of the degree of protection showed a significant efficacy of montelukast (p = 0.02) in comparison with placebo only at 12 h. Montelukast showed a significant protective effect 12 h after dosing, but no effect after 2 and 24 h. In mild asthmatics, the timing of administration of single dosage before exercise should be strictly considered in order to obtain the drug protective effects.
Follow‐up experience in pediatric liver transplantation in an academic, non‐transplant‐based gastroenterology group
Authors: Kessler Bradley , Gold David , Weinstein Toba , Levine Jeremiah , Pettei Michael
Published: March 2003

Abstract: As pediatric liver transplantation has become relatively common since the early 1980s, most long‐term follow‐up care has shifted from transplant centers to the pediatric gastroenterologists at referring institutions. We reviewed our experience with 16 patients who have undergone liver transplantation at eight institutions from 1987 to 1996. Our initial follow‐up visit took place at an average 4.1 months after the transplant. The mean duration of follow‐up was 41 months. During this period 11 hospitalizations at the transplant center occured, including five that were to rule out lymphoma or post‐transplant lymphoproliferative disease. At the Schneider Children’s Hospital, NY, USA, 158 outpatient visits were recorded. Forty‐two hospitalizations occured. Twenty of the hospital admissions were accounted for by two patients. Forty‐nine outpatient/inpatient surgical or diagnostic procedures were performed, including 15 percutaneous liver biopsies. In only one biopsy was there a disagreement in the histologic diagnosis between our pathologist and the pathologist at the transplant center. In conclusion, comprehensive follow‐up care can be provided by an academic hospital‐based gastroenterology group in conjunction with a transplant center.
Transplantation tolerance: The concept and its applicability
Authors: Dong Victor M. , Womer Karl L. , Sayegh Mohamed H.
Published: March 2003

Abstract: Recent advances have enabled researchers to induce tolerance in animal transplant models. Although it has been relatively easy to do so in rodents, it has been much more difficult to translate such strategies into primates. Understanding the cellular and molecular mechanisms of the alloimmune response has prompted the development of novel strategies that may obviate the need for immunosuppression in humans. Mechanisms of tolerance and promising new therapies, as well as the inherent difficulties in bringing them into clinical practice, are reviewed.
Mobilization/harvest and transplantation with blood stem cells, manipulated or unmanipulated
Authors: Kawano Yoshifumi , Watanabe Tsutomu , Takaue Yoichi
Published: March 2003

Abstract: Collection of peripheral blood stem cells (PBSC) is very feasible without the risk of anesthesia or invasive multiple bone marrow aspirations, because it can be accomplished by modification to the standard apheresis techniques that are routinely used at blood centers for the collection of single donor platelets. Use of PBSC results in rapid and durable trilineage hematopoietic recovery after myeloablative chemotherapy. There has been increasing development in technology for cell processing (‘graft engineering’), moving from the experimental to the clinical settings. Although peripheral blood stem cell transplantation (PBSCT) makes ‘cell component therapy’ far more effective than bone marrow transplantation, its advantages/disadvantages still need to be clarified in children. The following paper presents our pediatric experience of PBSCT.
Allogeneic hematopoietic stem‐cell engraftment and graft failure
Authors: Woolfrey Ann , Anasetti Claudio
Published: March 2003

Abstract: Two immunologically mediated reactions, the graft‐versus‐host (GvH) and host‐versus‐graft (HvG) responses, form primary and opposing barriers to successful transplantation of allogeneic hematopoietic stem‐cells (HSC). The HvG barrier is set by the strength of the allogeneic immune response, which is determined by antigenic stimulation provided by donor cells, owing to differences in histocompatibility antigens, and the capacity of host immune cells to generate a response. Risk of graft failure must be viewed as the interplay of multiple factors, including degree of human leukocyte antigen and minor histocompatibility antigen disparity, capacity of host immune response, and the capacity of donor hematopoietic and immunologic cells for overcoming residual host immunity.
Asymptomatic inferior vena cava abnormalities in three children withend‐stage renal disease: Risk factors and screening guidelines for pretransplant diagnosis
Authors: Thomas Susan E. , Hickman Robert O. , Tapper David , Shaw Dennis W. W. , Fouser Laurie S. , McDonald Ruth A.
Published: March 2003

We report two children with end‐stage renal disease (ESRD) found to have inferior vena cava (IVC) thrombosis at the time of renal transplantation. The children suffered from renal diseases that included congenital hepatic fibrosis and portal hypertension as part of their pathophysiology. Neither child had evidence of hypercoaguability or clinical symptoms of IVC thrombosis. Prior to transplantation, the renal replacement therapy consisted primarily of peritoneal dialysis. During their hospital courses, these children had central venous catheters placed for temporary hemodialysis, episodes of peritonitis and numerous abdominal surgeries. The medical literature to date has not identified a link between IVC thrombosis and portal hypertension, nor has an association between the patients’ primary renal disease and IVC thrombosis been found. We also report the finding of asymptomatic IVC narrowing in a third patient with obstructive uropathy, colonic dysmotility and numerous abdominal surgeries. IVC narrowing was diagnosed by CT scan during his pretransplant evaluation. In this paper, we consider similarities between these three patients that may have predisposed each of them to asymptomatic IVC pathology, including large‐bore central venous access as young children and/or recurrent scarring abdominal processes. A discussion regarding appropriate screening of the ‘high‐risk patient’ for IVC pathology prior to kidney transplantation and surgical options for children with this rare complication are presented.
Impaired exercise parameters in pediatric heart transplant recipients: Comparison of biatrial and bicaval techniques
Authors: Pahl Elfriede , Sundararaghavan Sreekanthan , Strasburger Janette F. , Mitchell Brett M. , Rodgers Sherrie , Crowley Dennis , Gidding Samuel S.
Published: March 2003

Abstract: The exercise performance of pediatric heart transplant recipients and the effects of bicaval anastomosis were studied in 19 children using a Bruce protocol. Although all children had decreased exercise capacity and heart rates when compared with normals, the bicaval anastomosis patients had similar endurance and peak heart rates as the standard biatrial group.
Regression of pulmonary arteriovenous malformations following heart transplantation
Authors: Lamour Jacqueline M. , Hsu Daphne T. , Kichuk Maryanne R. , Galantowicz Mark E. , Quaegebeur Jan M. , Addonizio Linda J.
Published: March 2003

Abstract: Pulmonary arteriovenous malformations (PAVMs) can occur following caval to pulmonary artery connection, Glenn and/or Fontan procedure, leading to severe cyanosis and exercise intolerance. It is unknown whether these abnormalities regress or persist following heart transplantation (HTx). Twenty patients with failed Fontan or Glenn procedures were screened for PAVMs prior to HTx by contrast echocardiography, selective pulmonary angiography, and pulmonary venous desaturation. Age at transplant, diagnosis, previous operations, time from Glenn to transplant, systemic oxygenation, hemoglobin level, and ventricular function were determined. The clinical course after HTx was characterized in three patients with significant PAVMs. Indications for HTx were exercise intolerance and severe cyanosis in one patient, and cyanosis and ventricular dysfunction in two. Pre‐HTx, mean systemic saturation was 67%; mean pulmonary venous wedge saturation was 81%. Post‐HTx, oxygen saturations were normal (> 96%) at 14, 40, and 180 days. Contrast echocardiography, performed 1 month to 3.3 yrs after HTx, showed no intrapulmonary shunting in two patients and minimal shunting in one. One patient suffered an embolic stroke from right‐to‐left shunting post‐HTx. All patients are alive and well 35, 71, and 73 months post‐HTx. In patients with single ventricle physiology, PAVMs are not an absolute contraindication to HTx. Heart–lung transplant may not be required for these patients.
Herpes simplex colitis in a child with combined liver and small bowel transplant
Authors: Delis S. , Kato T. , Ruiz P. , Mittal N. , Babinski L. , Tzakis A.
Published: March 2003

Abstract: Herpes simplex virus (HSV) has been a rare cause of gastrointestinal (GI) infection, especially in immunocompromised patients. A variety of GI sites may be involved; however, only three reported cases of HSV colitis have been documented in the literature. To our knowledge, this is the first report of HSV colitis in a small bowel transplant recipient.
Elevated tacrolimus trough levels in association with mycophenolate mofetil‐induced diarrhea: A case report
Authors: Frühwirth M. , Fischer H. , Simma B. , Ellemunter H.
Published: March 2003

Abstract: The combination of tacrolimus (TAC) and mycophenolate mofetil (MMF) is frequently used for immunosuppression after organ transplantation (Tx), but the pharmacokinetics and interactions between the two drugs are poorly elucidated. We describe here the increase of TAC trough levels during MMF‐induced diarrhea in a 8‐yr‐old boy after kidney Tx. Early dose reduction of TAC, together with short‐term monitoring of TAC trough levels in the presence of diarrhea, is recommended.
Milestones in the development of pediatric hematopoietic stem cell transplantation—50 years of progress
Authors: Trigg Michael E.
Published: March 2003

Abstract: In the 1950s, the first infusions of hematopoietic stem cells were given as a form of treatment for childhood leukemia. This heralded the beginning of a field that has expanded to include the treatment of immune deficiencies, a variety of leukemias and solid tumors, and then genetic diseases. A number of milestones are highlighted, particularly in regard to the use of alternative sources of hematopoietic stem cells such as unrelated donors, peripheral blood stem cells and umbilical cord stem cells. In addition, newer techniques of using non‐myeloablative preparative regimens helped to reduce the toxicity and long‐term consequences of hematopoietic stem cell transplant. Many diseases now benefit from the replacement of the marrow stem cells and the provision of a new immune system and improved immune surveillance.