bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of oral Actinomyces species using DNA probes
Authors: Ximénez‐Fyvie L. A. , Haffajee A. D. , Martin L. , Tanner A. , Macuch P. , Socransky S. S.
Published: March 2003

Oral Actinomyces comprise a major segment of both the supra‐ and subgingival microbiota; however, little is known about the distribution of individual species in different sites or clinical conditions. The purpose of the present investigation was to develop DNA probes for suggested species and genotypes of oral Actinomyces. Whole genomic DNA probes to 12 human oral species and/or serotypes were labeled with digoxigenin and used to seek cross‐reactions among the taxa using the checkerboard DNA‐DNA hybridization assay. The Actinomyces formed three distinct groups: 1) Actinomyces georgiae, Actinomyces meyeri and Actinomyces odontolyticus serotypes I and II; 2) Actinomyces viscosus and Actinomyces naeslundii serotypes I, II, III and WVA 963; and 3) Actinomyces gerencseriae and Actinomyces israelii. Cross‐reactions among taxa were detected and minimized by increasing the temperature of the post‐hybridization high‐stringency wash to 80°C. Despite the elevation in high stringency wash temperature, cross‐reactions among strains of the A. naeslundii/A. viscosus group persisted. Probes for two of the three currently recognized genospecies in this group were prepared by removing the DNA in common between cross‐reacting species using subtraction hybridization and polymerase chain reaction. Nine species and genospecies could be clearly separated by a combination of whole genomic and subtraction hybridization probes and by increasing the high‐stringency wash temperature. A total of 195 fresh isolates of Actinomyces were grouped in a blind study using DNA probes and separately by SDS‐PAGE protein profiles. Concordance between the two methods was 97.3%. The probes and hybridization conditions were tested for their ability to detect the Actinomyces species and genospecies in samples of supragingival and subgingival plaque from periodontitis subjects using checkerboard DNA‐DNA hybridization. The probes detected the species in samples of supragingival and subgingival plaque. We concluded that whole genomic and subtraction hybridization DNA probes facilitate the detection and enumeration of species and genospecies of Actinomyces in plaque samples.
Chemokine expression in Porphyromonas gingivalis–specific T‐cell lines
Authors: Gemmell E. , Grieco D. A. , Seymour G. J.
Published: March 2003

Autologous non‐T cells (monocytes and B cells) were added to Porphyromonas gingivalis–specific T cell lines established from 9 healthy adults together with P. gingivalis outer membrane antigens for 4–6, 16–18, 24 and 48 h. Flow cytometry was employed to analyze the CD4 and CD8 cells, monocytes and B cells for intracytoplasmic IP‐10 (interferon‐gamma inducible protein 10), MCP‐1 (monocyte chemoattractant protein 1), MIP‐1α (macrophage inflammatory protein 1α) and RANTES (regulated on activation normal T cell expressed and secreted) at the four time periods. All cell types were positive for each chemokine throughout the 48‐h time period. There were significantly fewer MCP‐1‐positive cells compared with the other 3 chemokines. However, the percentages of MCP‐1, MIP‐1α‐ and RANTES‐positive CD8 cells were significantly higher than the percentages of positive CD4 cells in all cultures. IP‐10‐positive CD4, CD14‐positive monocytes and CD19‐positive B cells were predominant compared with MIP‐1α‐ and RANTES‐positive cells at 24 h. In conclusion, the present study has shown that P. gingivalis–specific T cells, monocytes and B cells produce chemokines in response to P. gingivalis outer membrane antigens, IP‐10 being predominant, with MCP‐1 being significantly reduced in comparison with IP‐10, MIP‐1α and RANTES. Increased percentages of CD8 cells were induced to produce chemokines in comparison with CD4 cells, indicating a more preferential action on CD8 rather than CD4 cells.
Identification and characterization of B‐cell epitopes of a 53‐kDa outer membrane protein from Porphyromonas gingivalis
Authors: Oyaizu K. , Ohyama H. , Nishimura F. , Kurihara H. , Matsushita S. , Maeda H. , Kokeguchi S. , Hongyo H. , Takashiba S. , Murayama Y.
Published: March 2003

We have previously reported that Porphyromonas gingivalis FDC 381 possesses a 53‐kDa protein antigen (Ag53) on its outer membrane that evokes a strong humoral immune response in many patients with periodontal disease and that the humoral immune responses to Ag53 differ greatly among patients. To understand how the individual humoral immune system against Ag53 was determined, the regions of Ag53 recognized by specific antibody (B‐cell epitopes) and dominant subclasses of serum immunoglobulin G (IgG) against major B‐cell epitopes were examined by enzyme‐linked immunosorbent assay. This study used sera from six patients with periodontitis, which all reacted strongly with sonic extracts of P. gingivalis 381 and with purified Ag53, and sera from six periodontally healthy children, which did not react with either sonic extracts of P. gingivalis 381 or Ag53. The epitopes were identified using synthetic 5‐residue overlapping decapeptides covering the entire Ag53. Thirteen of 89 synthetic decapeptides showed a strong reaction with sera from the periodontal patients, but no reaction with those from the healthy children. Four peptides of 13 exerted different immune responses among patients. Furthermore, restriction analyses of the highly antigenic regions revealed that three sequences, RAAIRAS, YYLQ and MSPARR, were identified as major B‐cell epitopes. Additionally, these epitopes were recognized mainly by the IgG2 isotype. These data suggest that the difference of B‐cell epitopes might influence individual differences in antibody titer against Ag53 and also that the epitopes recognized commonly by multiple antibodies are quite valuable for peptide vaccine development against P. gingivalis infection.
The time‐course of acid excretion, levels of fluorescence dependent on cellular nicotinamide adenine nucleotide and glycolytic intermediates of Streptococcus mutans cells exposed and not exposed to air in the presence of glucose and sorbitol
Authors: Iwami Y. , Takahashi‐Abbe S. , Takahashi N. , Yamada T. , Kano N. , Mayanagi H.
Published: March 2003

The aim of this study was to examine glucose and sorbitol metabolism in Streptococcus mutans cells exposed and not exposed to air at the coexistence of these compounds by measuring acid excretion, levels of fluorescence dependent on cellular NADH and glycolytic intermediates. An aliquot of bacterial cells grown under strictly anaerobic conditions (anaerobic cells) was exposed temporarily to air (aerobic cells). When glucose was added to the anaerobic cells metabolizing sorbitol, the acid excretion was increased. The level of NADH decreased initially and then increased to the higher plateau level than that during glucose metabolism. The aerobic cells neither metabolized sorbitol nor contained glycolytic intermediates. However, 2 min after glucose was added in the presence of sorbitol, the acid excretion was started slowly and the intermediates appeared. The level of NADH was decreased at first and then increased. These results suggested that the anaerobic S. mutans cells metabolized glucose and sorbitol simultaneously, and that in the presence of sorbitol the aerobic cells could start to metabolize glucose 2 min after glucose was added, as the intermediates (phosphoenopyruvate potential) for the glucose transport were accumulated.
The purification and characterization of an 88‐kDa Porphyromonas endodontalis 35406 protease
Authors: Rosen G. , Shoshani M. , Naor R. , Sela M. N.
Published: March 2003

A Porphyromonas endodontalis ATCC 35406 protease was purified from Triton X‐114 cell extracts by preparative SDS‐PAGE followed by electroelution. The purified enzyme exhibits a molecular size of 88 kDa and was dissociated into two polypeptides of 43 and 41 kDa upon heating in the presence of sodium dodecyl sulfate with or without a reducing agent. The protease (pH optimum 7.5–8.0) degraded the extracellular matrix proteins fibrinogen and fibronectin. Collagen IV was also degraded at 37°C but not at 28°C. The protease also cleaved the bioactive peptide angiotensin at amino acid residue phenylalanine‐8 and tyrosine‐4 but failed to hydrolyze bradykinin, vasopressin and synthetic chromogenic substrates with phenylalanine or tyrosine at the P1 position. In addition, two peptidases were detected in P. endodontalis cells: a proline aminopeptidase that remained associated with the cell pellet after detergent extraction and peptidase/s that partitioned into the Triton X‐114 phase after phase separation and degraded the bioactive peptides bradykinin and vasopressin. These P. endodontalis peptidases and proteases may play an important role in both the nutrition and pathogenicity of these assacharolytic microorganisms. The inactivation of bioactive peptides and degradation of extracellular matrix proteins by bacterial enzymes may contribute to the damage of host tissues accompanied with endodontic infections.
The characterization of a (nutritionally important) proline iminopeptidase from Eikenella corrodens
Authors: Gully N. J. , Rogers A. H.
Published: March 2003

Eikenella corrodens generates energy primarily through the oxidative deamination of specific amino acids, a process that is coupled to dissimilatory nitrate reduction to nitrite. Cell yields resulting from chemostat‐growth of the organism in simple, chemically defined media containing varying amounts of proline confirm that this amino acid is a likely source of energy for E. corrodens in the oral environment. The importance of proline in ATP generation by the organism is reflected in molar growth yields, which showed that biomass production per mole of this amino acid was significantly higher than that for other amino acids. The organism was found to express, constitutively, the enzyme proline iminopeptidase, which releases proline from the N‐terminus of small peptides. The enzyme was partially purified and characterized and found to exist in the cytoplasm as a 35 kDa monomer. Inhibition studies showed that the enzyme, although classified as a serine protease, also appears to require thiol groups for activity, a finding which is consistent with previous reports. The enzyme obeyed Michaelis‐Menten kinetics and was found to have a Km value of 0.223 mM for the substrate proline‐p‐nitroanilide.
Prevalence of yeast among children in Nigeria and the United States
Authors: Jabra‐Rizk M. A. , Falkler W. A. , Enwonwu C. O. , Onwujekwe D. I. , Merz W. G. , Meiller T. F.
Published: March 2003

Fungal infections have gained considerable importance over the last decade as a result of significant increase in the incidence of opportunistic and systemic candidosis. Although Candida albicans is the predominant causative agent of candidosis, particularly oral disease, recently an epidemiological trend has been observed where other less pathogenic species of Candida, including the newly characterized species Candida dubliniensis, are emerging as significant opportunistic pathogens. The present study aimed to screen for the presence of C. dubliniensis and to compare the recovery of yeast species from 30 seemingly healthy and 30 HIV‐positive children in the United States, as well as from 64 malnourished Nigerian children. Oral samples were cultured for fungal growth, and all germ tube and chlamydospore positive isolates were tested for ability to grow at 45 °C to differentiate between C. albicans and C. dubliniensis. All isolates were speciated based on colony color production on CHROMagar medium and sugar assimilation profiles. Among the 30 HIV‐positive children, 15 (50%) were positive for fungus; 12 were positive for C. albicans, with one of the latter also positive for Candida glabrata, and three were found to harbor C. dubliniensis. Among the 30 non‐HIV‐positive children, five C. albicans and four C. dubliniensis isolates were recovered. No C. dubliniensis isolates were recovered from the Nigerian group. However, eight other different yeast species were recovered from 31 (48.4%) of the 64 Nigerian children sampled, with six of them growing a combination of species. In comparing the data from the Nigerian and United States children, the frequency of yeasts in the malnourished Nigerian group was considerably higher. The most striking difference between the two groups was in the variety of the usually less encountered and less pathogenic yeast species recovered from the Nigerian population. The findings support previously reported observations that there may be intrinsic differences between different populations sampled and that malnutrition might favor the presence of yeast species other than C. albicans.
Evaluation of interleukin 1 as a mucosal adjuvant in immunization with Streptococcus sobrinus cells by tonsillar application in rabbits
Authors: Kokuryo S. , Inoue H. , Fukuizumi T. , Tsujisawa T. , Tominaga K. , Fukuda J.
Published: March 2003

To evaluate interleukin 1 (IL‐1) as a mucosal adjuvant in the induction of salivary antibodies to Streptococcus sobrinus, S. sobrinus together with IL‐1 was applied through the palatine tonsils of rabbits. IL‐1 caused approximately 50 and 100% increases in the antibodies reacting against S. sobrinus fragments in the saliva and blood plasma, respectively, compared to the antibodies in those same fluids after tonsillar applications of S. sobrinus alone. In the case of the addition of IL‐1, the antibodies reacting to the protein antigens of S. sobrinus increased in each fluid, without affecting the antibodies reacting to saccharide antigens. Delayed‐type hypersensitivity to S. sobrinus, characterized by ear swelling and by an increase in IFN‐γ mRNA in RT‐PCR analysis, was found to be induced only in rabbits immunized with IL‐1. S. sobrinus protein antigens caused ear swelling as intense as that caused by S. sobrinus fragments. Thus, IL‐1 induced an antibody response and cell‐mediated immunity mainly reacting to protein antigens of S. sobrinus.
In vivo induction of proinflammatory cytokines in mouse tissue by Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans
Authors: Kesavalu L. , Chandrasekar B. , Ebersole J. L.
Published: March 2003

Periodontitis is a chronic inflammatory disease initiated by a multitude of bacteria. Persistent infection leads to generation of various inflammatory mediators, resulting in tissue destruction and osteoclastic resorption of the alveolar bone. This study describes a novel in vivo murine calvarial model to assess the effects of oral pathogens on the expression of three proinflammatory cytokines [interleukin (IL)‐1β, IL‐6, and tumor necrosis factor (TNF)‐α] which are involved in bone resorption. We chose Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans as prototype oral pathogens. We also tested the effects of Streptococcus gordonii, an oral commensal supragingival microorganism, considered a non‐pathogen. Live bacteria were injected into subcutaneous tissue overlying the parietal bone of mice calvaria for 6 days. At the end of the experimental period, tissues overlying the calvaria were removed and analyzed for proinflammatory cytokine expression by Northern blotting. Cytokine mRNA was not detected in the tissue over the calvaria of control animals. In contrast, P. gingivalis and A. actinomycetemcomitans elicited mRNA expression of all three cytokines, TNFα being the highest (TNFα > > IL‐1β > IL‐6). P. gingivalis was more potent than A. actinomycetemcomitans in inducing cytokine expression. In contrast, S. gordonii induced only low levels of mRNA for IL‐1β and TNFα but no IL‐6 mRNA induction. These results suggest that oral microorganisms with access to host tissues elicit a battery of proinflammatory cytokines. There were clear differences in profiles and, interestingly, a commensal bacterium also stimulated bone resorptive cytokine expression in host tissues.
Intracellular and extracellular pHs of Streptococcus mutans after addition of acids: loading and efflux of a fluorescent pH indicator in streptococcal cells
Authors: Iwami Y. , Kawarada K. , Kojima I. , Miyasawa H. , Kakuta H. , Mayanagi H. , Takahashi N.
Published: March 2003

A pH‐sensitive fluorescent dye, 2′, 7′‐bis‐(2‐carboxyethyl)‐5 and 6‐carboxyfluorescein (BCECF), was used to determine intracellular pH (pHin). The efflux of BCECF loaded into oral streptococcal cells was determined after incubation of the cells at 35°C for 20 min in the presence and absence of glucose. In the absence of glucose, the fluorescence of intracellular BCECF in Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius and Streptococcus sobrinus decreased only very slightly, indicating that the dye could be useful for pHin determination. In the presence of glucose, however, the fluorescence decreased by 57%. Thus, the pHin of S. mutans cells was measured by the BCECF method in the absence of glucose at various acidic pH levels by adding lactic, acetic and hydrochloric acids to the cell suspensions. The pHin was almost equal to the extracellular pH (pHout) for pHout values of between 8 and 5, indicating that protons permeated easily across the S. mutans cell membrane. For pHout between 5 and 4, pHin was constant at around 5, suggesting that the cell membrane was impermeable to protons, or that a cytoplasmic buffering system functioned. pHin decreased at pHout values of < 4. The constant pHin at acidic pHout levels could protect intracellular components, such as proteins, against acidification by sugar fermentation.
Salivary cytokine profiles in the immunocompetent individual with Candida‐associated denture stomatitis
Authors: Leigh J. E. , Steele C. , Wormley F. , Fidel P. L.
Published: March 2003

Cell‐mediated immunity conferred by CD4+ T helper cells is considered the predominant host defense against mucosal Candida infections, with Thelper (Th1)‐type responses associated with resistance to infection and Th2‐type responses associated with susceptibility to infection. Oropharyngeal candidiasis, the most common oral opportunistic infection in HIV‐infected persons, is associated with a Th2‐type cytokine profile in saliva. To obtain more direct evidence for a role of salivary cytokines in susceptibility to oropharyngeal candidiasis during immunosuppression, we evaluated Th1/Th2‐type cytokines in the saliva of those with denture stomatitis, a form of oropharyngeal candidiasis not related to immunosuppression. Results showed that HIV‐negative denture wearers with and without denture stomatitis demonstrated a mixed Th1/Th2 cytokine profile with no significant differences found between the groups. These results suggest that a local Th cytokine dichotomy in saliva is not associated with susceptibility to denture stomatitis in immunocompetent persons.
Sequence diversity in the major fimbrial subunit gene (flp‐1) of Actinobacillus actinomycetemcomitans
Authors: Kaplan J. B. , Kokeguchi S. , Murayama Y. , Fine D. H.
Published: March 2003

Cells of the periodontal pathogen Actinobacillus actinomycetemcomitans exhibit tight adherence to surfaces such as glass, plastic and hydroxyapatite, a property that probably plays an important role in the ability of this bacterium to colonize teeth and other surfaces. Tight adherence is mediated by long fibrils of bundled pili (fimbriae) that form on the surface of the cell. The flp‐1 gene encodes the major pilin protein component of A. actinomycetemcomitans fimbriae. In this study we compared flp‐1 DNA sequences from 43 strains of A. actinomycetemcomitans isolated in Europe, Japan and the United States and identified seven distinct flp‐1 allelic classes. DNA and predicted protein sequences were almost completely conserved within each flp‐1 class but were highly divergent between classes. Most amino acid substitutions occurred in the C‐terminus of the pilin protein, a region that has been shown to be important for the bundling and adhesive properties of the pili. flp‐1 classes correlated with serotypes and 16S rRNA genotypes in most strains. At least five strains showed evidence of horizontal transfer of flp‐1 between strains of different serotypes and 16S rRNA genotypes. Four of the seven flp‐1 classes were present in geographically diverse isolates. Strains representing all seven flp‐1 classes, but not a strain carrying a transposon insertion in flp‐1, bound avidly to polystyrene in an in vitro adherence assay. Strains representing six of the seven flp‐1 classes were isolated from localized juvenile periodontitis patients, suggesting that phylogenetically diverse strains carry pathogenic potential. Our findings provide a framework for future biochemical, immunological and genetic studies of A. actinomycetemcomitans fimbriae.
Early life exposure to dietary and inhalant allergens
Authors: Vance Gillian H. S. , Holloway Judith A.
Published: March 2003

Increasing evidence points to early life, including fetal life, as being a critical time period during which the infant's allergic fate may be determined. However, initial antigen priming in utero necessitates fetal exposure to maternally derived allergen. This article reviews our current knowledge regarding materno‐fetal allergen transfer in vivo and reflects on mechanisms by which this exposure might exert immunomodulatory influences on the developing immune system.
Age at adoption, ethnicity and atopic disorder: A study of internationally adopted young men in Sweden
Authors: Hjern Anders , Rasmussen Finn , Hedlin Gunilla
Published: March 2003

Epidemiological and laboratory studies have implied that the environment during early childhood is important for the risk of developing atopic disorders. In this study we analyzed the prevalence of asthma, hayfever and eczema among 1901 internationally adopted young men at the military‐induction medical examination in relation to indicators of their early childhood environment. The adopted young men who came to Sweden before 2 years of age suffered from asthma, hayfever and eczema significantly more often than those who came to Sweden between 2 and 6 years of age; the risk ratios (RR) were 1.6, 2.5 and 2.1, respectively. The young men who were born in the Far East were identified as being particularly susceptible to the development of hayfever and eczema, with RRs of 1.3 and 1.7. This study demonstrates that the environment during the first 6 years of life has a profound influence on the risk of suffering from atopic disorders as young adults.
Seasonal variability in exercise test responses in Ghana
Authors: Addo‐Yobo Emmanuel O. D. , Custovic Adnan , Taggart Simon C. O. , Asafo‐Agyei A. P. , Woodcock Ashley
Published: March 2003

Exercise‐induced bronchospasm (EIB) is widely used in epidemiological studies to investigate the prevalence of asthma. We aimed to determine seasonal variations in the prevalence of EIB in Ghanaian school children from urban‐rich (UR), urban‐poor (UP), and rural (R) schools. We have previously reported the prevalence of EIB in 9–16‐year‐old children to be 3.1% in the dry season, with UR children having a significantly higher prevalence of both EIB and atopy compared to UP or R children. In the current study, the prevalence of EIB was assessed in the same 1,095 children in the wet season (5 months following the initial study) using the same methodology. Exercise provocation consisted of free running outdoors for 6 min. In the wet season, 17/1,095 children [mean 1.55%, 95% confidence interval (CI): 0.91–2.47] had a positive response to exercise, compared to our previous report of 34 children (mean 3.1%, 95% CI: 2.15–4.32) with EIB in the dry season (dry vs. wet season, difference 1.55, 95% CI: 0.41–2.69). The proportion of children with a positive response to exercise in the UR school fell from 4.2% (25/599) to 1.3% (8/599) (difference 2.9, 95% CI: 1.2–4.5). In the wet season, there was no difference in the prevalence of EIB among the UR, UP, and R children. Only five of 1,095 subjects (mean 0.5%, 95% CI: 0.15–1.07) demonstrated EIB in both seasons. In conclusion, although exercise challenge remains a useful tool for determining asthma prevalence in epidemiological studies, seasonal variations in the pattern of responses may occur and the results should be interpreted with caution.
Relationships among specific viral pathogens, virus‐induced interleukin‐8, and respiratory symptoms in infancy
Authors: Gern James E. , Martin Matthew S. , Anklam Kelly A. , Shen Kunling , Roberg Kathy A. , Carlson‐Dakes Kirstin T. , Adler Kiva , Gilbertson‐White Stephanie , Hamilton Rebekah , Shult Peter A. , Kirk Carol J. , Da Silva Douglas F. , Sund Sarah A. , Kosorok Michael R. , F. Lemanske Robert
Published: March 2003

Both virus‐mediated damage to airway tissues and induction of pro‐inflammatory cytokines such as interleukin‐8 (IL‐8) could contribute to symptom severity during viral respiratory infections in children. To test the hypothesis that IL‐8 contributes to the pathogenesis of respiratory symptoms during naturally acquired respiratory viral infections in children, nasal wash samples collected from infants with acute viral infections (n = 198) or from healthy uninfected infants (n = 31) were analysed for IL‐8. Nasal wash IL‐8 was positively related to age in uninfected children (rs = 0.36, p < 0.05). Respiratory syncytial virus (RSV) infection caused more severe respiratory symptoms compared to infections with influenza A, parainfluenza viruses, or rhinoviruses. In addition, RSV, parainfluenza and rhinovirus infections increased levels of IL‐8 in nasal lavage fluid, and there were some differences in the ability of the viruses to induce IL‐8 production (RSV>influenza, p < 0.05). Finally, there were significant correlations between nasal wash IL‐8 levels and symptom scores during infections with rhinovirus (rs = 0.56, p < 0.001) or influenza A (rs = 0.45, p < 0.05), but not with parainfluenza virus or RSV. These findings provide evidence of a close relationship between the generation of IL‐8 and symptoms during acute community‐acquired infections with rhinovirus or influenza A. In contrast, for RSV and parainfluenza infections, factors in addition to IL‐8 production appear to contribute to the generation of clinical symptoms.
Treatment of progressive familial intrahepatic cholestasis: Liver transplantation or partial external biliary diversion
Authors: Ismail Hor , Kaliciński Piotr , Markiewicz Małgorzata , Jankowska Irena , Pawłowska Joanna , Kluge Przemysław , Eliadou Eliana , Kamiński Andrzej , Szymczak Marek , Drewniak Tomasz , Revillon Yann
Published: March 2003

Abstract: Progressive intrahepatic familial cholestasis (PFIC), previously called Byler’s disease, is a syndrome in which children develop severe cholestasis progressing to biliary cirrhosis and chronic liver failure, usually during the first decade of life. Clinical features include jaundice, hepatomegaly, splenomegaly, growth retardation and severe pruritis. Laboratory tests demonstrate elevated bilirubin and bile acids, without an increase in serum gamma‐glutamyl‐transpeptidase or cholesterol. This study was performed to evaluate our experience with medical therapy as well as two types of surgical treatment used in children with PFIC, particularly partial external biliary diversion (PEBD) as an alternative method of therapy to liver transplantation (OLTx). Between 1979 and 1998 we have treated 46 children with PFIC (27 boys and 19 girls), aged 10 months to 19 yr (at the time of this study). Medical treatment with ursodeoxycholic (UDCA) was used in 39 patients for the period between 6 and 82 months. PEBD (cholecysto‐jejuno‐cutaneostomy) was performed in 16 patients, OLTx in eight children (including one after unsuccessful PEBD). Retrospective analysis of the clinical course and selected laboratory tests (bilirubin, ASPAT, ALAT, bile acids), and histopathological examinations were performed. Results of treatment were assessed by means of influence of the type of treatment on clinical symptoms, laboratory tests, progress of liver cirrhosis and hepatic failure, as well as physical development and survival. Medical therapy was effective in the long term in four (10%) of the patients resulting in clinical and biochemical normalization. Both surgical methods of therapy of PFIC, PEBD and OLTx, resulted in an 80% success rate and therefore should be used as complementary therapies. In patients before established liver cirrhosis, PEBD should be the first choice of treatment. Patients presenting with cirrhosis or after ineffective PEBD should qualify for OLTx. With this strategy most children with PIFC can be cured.
Indications for pediatric intestinal transplantation: A position paper of the American Society of Transplantation
Authors: Kaufman Stuart S. , Atkinson James B. , Bianchi Adrian , Goulet Olivier J. , Grant David , Langnas Alan N. , McDiarmid Sue V. , Mittal Naveen , Reyes Jorge , Tzakis Andreas G.
Published: March 2003

Abstract: Parenteral nutrition represents standard therapy for children with short bowel syndrome and other causes of intestinal failure. Most infants with short bowel syndrome eventually wean from parenteral nutrition, and most of those who do not wean tolerate parenteral nutrition for protracted periods. However, a subset of children with intestinal failure remaining dependent on parenteral nutrition will develop life‐threatening complications arising from therapy. Intestinal transplantation (Tx) can now be recommended for this select group. Life‐threatening complications warranting consideration of intestinal Tx include parenteral nutrition‐associated liver disease, recurrent sepsis, and threatened loss of central venous access. Because a critical shortage of donor organs exists, waiting times for intestinal Tx are prolonged. Therefore, it is essential that children with life‐threatening complications of intestinal failure and parenteral nutrition therapy be identified comparatively early, i.e. in time to receive suitable donor organs before they become critically ill. Children with liver dysfunction should be considered for isolated intestinal Tx before irreversible, advanced bridging fibrosis or cirrhosis supervenes, for which a combined liver and intestinal transplant is necessary. Irreversible liver disease is suggested by hyperbilirubinemia persisting beyond 3–4 months of age combined with features of portal hypertension such as splenomegaly, thrombocytopenia, or prominent superficial abdominal veins; esophageal varices, ascites, and impaired synthetic function are not always present. Death resulting from complications of liver failure is especially common during the wait for a combined liver and intestinal transplant, and survival following combined liver and intestinal Tx is probably lower than following an isolated intestinal transplant. The incidence of morbidity and mortality following intestinal Tx is greater than that following liver or kidney Tx, but long‐term survival following intestinal Tx is now at least 50–60%. It is probable that outcomes shall improve in the future with continued refinements in operative technique and post‐operative management, including immunosuppression.
Biliary stricture in living‐related donor liver transplantation: Management with balloon dilation
Authors: Schwarzenberg Sarah Jane , Sharp Harvey L. , Payne William D. , Hunter David W. , Bjarnason Haraldur , Humar Abhinav , Weisdorf‐Schindele Sally A. , Gruessner Rainer W.
Published: March 2003

Abstract: Biliary stricture is a recipient graft complication, occurring late in the post‐operative period, which appears to occur with increased frequency in living‐related donor liver transplantation (LRD LTx). We reviewed the experience at the University of Minnesota in managing a biliary complication of LRD LTx. Since January 1997, 13 LRD transplants have been performed using the technique of transplantation of the left lateral segments with a small portion of segment IV. All patients had hepaticojejunostomies using a Roux‐en‐Y loop. Of the 11 surviving patients, eight had evidence of cholangitis (Gram‐negative sepsis, two patients; ascending cholangitis, three patients; or unexplained fever with elevated liver enzymes, three patients) 4–8 months after otherwise successful transplantation. Six of the patients underwent percutaneous transhepatic cholangiography (PTC) with demonstration of a stenosis at the site of the biliary anastomosis. Repeated dilation of the anastomosis led to resolution of the stenoses, normalization of liver enzymes, and prevention of further episodes of infection. No patient required revision of the hepaticojejunostomy. Computed axial tomography evidence of ductal stenosis may be subtle in this group of patients, but PTC is diagnostic. We suggest a high index of suspicion of biliary stricture in the LRD LTx population. Biliary dilation reduces the risk of life‐threatening sepsis.
Cholelithiasis in pediatric organ transplantation: Detection and management
Authors: Ganschow Rainer
Published: March 2003

Abstract: The real incidence and the underlying causes of cholelithiasis in pediatric solid organ recipients is probably not exactly known. In addition to well‐established risk factors for cholelithiasis, children after heart, kidney, or liver transplantation may develop gallstones due to drug therapy, sepsis, parenteral nutrition, or surgical complications. For pediatric patients, data are very limited and heterogeneous. However, the incidence in pediatric heart recipients seems to be substantially higher compared with kidney or liver graft recipients. In this review article the present data are discussed focusing on incidence, detection, and management of cholelithiasis in pediatric organ transplantation. In general, surgery is the therapy of choice in symptomatic patients; however, the pharmacological profile of ursodeoxycholic acid and the first results on its clinical impact are promising. The value of prophylactic therapy with ursodeoxycholic acid must be determined in further studies.
Transient hyperphosphatasemia after organ transplantation in children
Authors: Ranchin Bruno , Villard Florence , André Jean‐Luc , Canterino Isabelle , Said Marie‐Hélène , Boisson Renée‐Claude , Lachaux Alain , David Louis , Cochat Pierre
Published: March 2003

Abstract:Transient, isolated hyperphosphatasemia is a rare, benign condition of childhood. Few cases have been described in transplant patients. We report six cases: three after liver transplantation and three after kidney transplantation. Such a phenomenon was found to be as benign after organ transplantation as it is in healthy children. Hence, an isolated increase in the serum alkaline phosphatase level following transplantation should not be of concern in this population of patients .
Tacrolimus‐induced pain syndrome in a pediatric orthotopic liver transplant patient
Authors: Malat G. E. , Dupuis R. E. , Kassman B. , Rhoads J. M. , Freeman K. , Lichtman S. , Johnson M. W. , Gerber D. , Andreoni K. , Fair J.
Published: March 2003

Abstract: Post‐transplant complications are common among patients receiving immunosuppressive medications, including pain syndromes. Recently, a pain syndrome, calcineurin‐inhibitor induced pain syndrome (CIPS) has been described. To our knowledge, this article is the second report of tacrolimus‐associated CIPS, and the first report in the pediatric setting.
Universal approach to pharmacokinetic monitoring of immunosuppressive agents in children
Authors: Filler G. , Feber J. , Lepage N. , Weiler G. , Mai I.
Published: March 2003

Abstract: Current data indicate that pharmacokinetic (PK) monitoring of cyclosporin microemulsion (CsA) should be performed using the 2‐h concentration (C2), that tacrolimus (Tac) is commonly monitored using the trough level, and mycophenolate mofetil (MMF) should be monitored using the 1‐h (C1), 2‐h (C2) and 6‐h (C6) concentrations. The three differing time‐point requirements are cumbersome, and we aimed to develop universal guidelines for all three drugs using a large number of full PK profiles in children. One‐hundred and twenty two stable pediatric patients, receiving either CsA (165 PK profiles, 69 patients, 24 with concomitant MMF) or Tac (122 PK profiles, 53 patients, 18 with MMF) were analyzed retrospectively. Pearson r for the CsA C2 was 0.90 [95% confidence interval(CI): 0.86–0.92], for Tac C2 r was 0.86 (95% CI: 0.80–0.90), and for MPA C2 r was 0.77 (95% CI: 0.68–0.83), respectively. For MPA, at least three time‐points are required to accurately estimate the area under the concentration–time curve (AUC), and C1, C2 and C6 serve as best markers. Excellent AUC estimations could be obtained from a limited sampling strategy from C1, C2 and C6 or C0, C1, C2 and C4 with clinically acceptable errors for all three drugs. The AUC can be estimated with great precision by using an identical approach for all three drugs. Target AUCs for a given time‐point after transplantation remain to be established.
Human herpesvirus‐6 and ‐7 infections in transplantation
Authors: Yoshikawa T.
Published: March 2003

Abstract: Human herpesvirus‐6 (HHV‐6) and human herpesvirus‐7 (HHV‐7) are ubiquitous in the human population and cause exanthem subitum, a benign disease seen in infancy. The viruses remain latent in the body after primary infection, and reactivate in immunocompromised patients. HHV‐6 infection occurs in nearly 50% of all bone marrow and in 20–30% of solid‐organ transplant recipients, 2–3 weeks following the procedure. It has been suggested that the viral infection and activation result in clinical symptoms, including fever, skin rash, pneumonia, bone marrow suppression, encephalitis, and rejection. In order to understand the viral infection in greater detail, several studies investigating the route of viral transmission and diagnostic procedures have been carried out. In contrast to studies of HHV‐6 infection in organ‐transplant recipients, the number of studies examining HHV‐7 infection in these patients is limited. According to several recent studies, HHV‐7 may act as a cofactor for cytomegalovirus disease in organ‐transplant recipients.
Appearance of peroxidase isozymes in floral‐initiated shoot apices of Pharbitis nil
Authors: Nakanishi F. , Fujii T.
Published: March 2003

A novel biochemical assay system for detecting the early stage of flowering is reported. Peroxidase isozymes in shoot apices of Pharbitis nil plants that had been exposed to flower‐inducing or non‐inducing conditions were analyzed by isoelectric focusing in polyacrylamide gels and activity staining for peroxidase. Several isozymes with pH 8.5–8.8 appeared for the first time 7 days after the beginning of short‐day treatment, but not after nightbreak (non‐inducing) treatment. When shoot tips were cultured in vitro, these same isozymes also appeared after short‐day treatment but not after night‐break treatment. The extent of the appearance of these isozymes was reduced by exposure to high or low temperature during the inductive dark period and removal of cotyledons after the inductive dark period. Such treatments also reduced the extent of flowering. The appearance of an isozyme with pH 8.5 was more closely correlated with flowering than that of the other isozymes. From these results, the appearance of this peroxidase isozyme in shoot apices is discussed as a biochemical marker of flowering in intact plants and in cultured shoot tips.
Effect of exogenous gibberellin A4/7 on tracheid production, longitudinal growth and the levels of indole‐3‐acetic acid and gibberellins A4, A7 and A9 in the terminal shoot of Pinus sylvestris seedlings
Authors: Wang Q. , Little C. H. A. , Sheng C. , Odén P. C. , Pharis R. P
Published: March 2003

Gibberellin A4/7 (GA4/7) was applied twice weekly to 2‐year‐old Pinus sylvestris (L.) seedlings in each of two years, starting close to budbreak and ending after shoot elongation, but before cambial activity ceased. In 1988, the GA4/7 was injected into the 1987 terminal shoot (0, 0.2 or 2 mg seedling−1 application−1), while in 1990 it was applied as a soil drench (0, 10 or 50 mg seedling−1 application−1). In the 1988 experiment, GA4/7 treatment promoted diameter growth, and tended to increase both longitudinal growth and the indole‐3‐acetic acid (IAA) level in the 1988 terminal. In the 1990 experiment, GA4/7 treatment increased tracheid production, longitudinal growth, and the cambial region IAA concentration in the 1990 terminal, but did not affect its pith diameter, needle number, needle dry weight, or needle IAA level. Tracheid production in the previous‐year's terminal was also promoted in both experiments. The 50 mg GA4/7 soil drench markedly elevated the concentrations of GA4, GA7 and GA9 in the needles and cambial region of the 1990 terminal, while the 10 mg treatment raised the GA4 level in the cambial region, providing evidence that GA4 and GA7 applied to the roots reaches the shoot system. The results support the hypothesis that the exogenous GA4/7‐induced stimulation of tracheid production in the terminal shoot of intact plants is mediated through an increase in the IAA level in the cambial region. However, per se activity of GA4, GA7 or their metabolites cannot be ruled out.
NMR imaging of roots: effects after root freezing of containerised conifer seedlings
Authors: Southon Timothy E. , Mattsson Anders , Jones Richard A.
Published: March 2003

Seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L) Karst.] were subjected to low root temperatures, and 10 days later the roots were examined by NMR imaging. The amount of NMR detectable roots decreased with decreasing temperature, with the signal from the younger roots at the bottom of the container being the first to disappear. The origin of the loss of NMR signal is unclear but may be due to changes in the NMR properties of root water after cold damage. A recent method is discussed for obtaining unbiased estimates of root lengths from a series of total vertical projections; the method is particularly suited to evaluating NMR projection images. Since NMR imaging methods can apparently distinguish between control and cold damaged roots, it may be possible to design more routine applications using low resolution NMR methods.
Jasmonic acid promotes germination and lipase activity in non‐stratified apple embryos
Authors: Ranjan Rajiv , Lewak Stanisław
Published: March 2003

The effects of (−)jasmonic acid (JA) on germination of embryos isolated from dormant seeds of apple (Malus domestica Borb. cv. Antonówka) cultured in darkness or at 12‐h photoperiod were studied, as well as its effects on the activity of alkaline lipase (AlkL, EC 3.1.1.3) in these embryos. The maximum sensitivity of germination to JA occurred on days 3 and 4 of embryo culture. Both germination and enzyme activity were stimulated by JA, its effect being additive to that of light. Inhibitors of lipoxygenase inhibited embryo germination and AlkL activity, both effects being partially reversed by JA treatment. We suggest that (1) JA is implicated in an endogenous complex controlling apple seed germination, and that (2) it acts independently of the mechanism triggered by light.
The induction of freezing tolerance in jack pine seedlings: The role of root plasma membrane H+‐ ATPase and redox activities
Authors: Zhao Sheyun , Colombo Stephen J. , Blumwald Eduardo
Published: March 2003

The acquired freezing tolerance of jack pine seedlings (Pinus banksiana Lamb.) conditioned at low nonfreezing temperatures and short photoperiods was determined by comparison of seedling survival to that of nonconditioned (control) seedlings following exposure to −5 and −10°C. Compared to that of controls, survival of conditioned seedlings was markedly increased following exposure to freezing temperatures. A 1‐week conditioning treatment significantly increased the survival of the seedlings after exposure to −5°C, but was less effective on seedlings exposed to −10°C. Conditioning periods of 2 and 4 weeks resulted in higher survival of seedlings exposed to both −5 and −10°C. The changes of two root‐plasma‐membrane‐associated enzyme activities, H+‐ATPase and NADH‐dependent ferricyanide reductase, were studied in enriched plasma membrane fractions during conditioning and after freezing. Post‐freezing activities of both enzymes were enhanced by conditioning at low temperatures and short photoperiods. These changes may be related to the increased frost hardiness also induced by conditioning.
Embryogenic cell suspensions from the male flower of Musa AAA cv. Grand nain
Authors: Côte F. X. , Domergue R. , Monmarson S. , Schwendiman J. , Teisson C. , Escalant J. V.
Published: March 2003

There are very few reports on the establishment of long‐term embryogenic cell cultures of banana, especially of triploid cultivars of commercial interest. Embryogenic cell suspensions were prepared using the cultivar Grand nain, the most widely grown dessert banana in the world. After culture for 5 or 6 months of immature male flowerbuds adjacent to the floral apex, yellow, compact calluses and white, friable embryogenic tissues were induced. Suspension cultures were initiated from embryogenic tissues placed in liquid medium. The packed cell volume (PCV) of the suspensions increased 2‐ to 5‐ fold with each monthly culture cycle. Plating of the embryogenic suspensions resulted in approximately 370×103 embryos per ml of PCV. Depending on the size of embryos, 3 to 20% germination was observed. A histological survey of cell suspensions and embryo development was carried out. Cellular aggregates with cells displaying typical embryogenic features were formed. Most of the somatic embryos were probably of unicellular origin.
Mechanisms of Al‐induced iron chlorosis in wheat (Triticum aestivum). Al‐inhibited biosynthesis and secretion of phytosiderophore
Authors: Chang Yi‐Chieh , Ma Jian Feng , Matsumoto Hideaki
Published: March 2003

Although Al‐induced iron chlorosis has been observed in many plants, the mechanisms responsible for this phenomenon are yet to be understood. We investigated the effect of Al on iron acquisition in a Strategy II plant, wheat (Triticum aestivum L.) using both Al‐tolerant (Atlas 66) and ‐sensitive (Scout 66) cultivars. When iron was supplied as insoluble iron, ferric hydroxide, in the culture solution, both cultivars without Al treatment grew normally, while those with 100 µM AlCl3 developed chlorosis of the young leaves after 3 days of the treatment. A 21‐h treatment with 100 µM AlCl3 in 0.5 mM CaCl2 solution (pH 4.5) decreased the amount of 2′‐deoxymugineic acid (DMA) secreted by Fe‐deficient Atlas 66 and Scout 66 plants by 85 and 90%, respectively. The amount of DMA secreted decreased with increasing external Al concentrations. Al treatment during the biosynthesis process caused the inhibition of that of DMA within 3 h. The secretion process was also found to be inhibited by Al, resulting in the biosynthesized DMA remaining in the roots. These results demonstrate the inhibition by Al of both biosynthesis and secretion of DMA attributed to Al‐induced iron chlorosis.
Induction of thaumatin‐like proteins (TLPs) in Rhizoctonia solani‐infected rice and characterization of two new cDNA clones
Authors: Velazhahan Rethinasamy , Chen‐Cole Kunwei , Anuratha Coimbatore S. , Muthukrishnan Subbaratnam
Published: March 2003

Thaumatin‐like proteins (TLPs) were shown to be induced in rice plants (cv. IR58) that were infected with the sheath blight fungus, Rhizoctonia solani. Western blot analysis revealed the presence of two TLPs with sizes of 25 and 24 kDa which are different from a previously reported TLP with a size of 15.6 kDa from rice plants infiltrated with the non‐pathogenic bacterium, Pseudomonas syringae pv. syringae. By probing a cDNA expression library prepared from RNA isolated from R. solani‐infected rice plants with a TLP antibody, several putative TLP cDNA clones were isolated and sequenced. The cDNA clones appeared to be derived from two different genes which shared only 77% sequence identity with each other and a lower percentage of sequence identity with the previously reported TLP cDNA clone. Southern blot analysis with the two TLP cDNAs revealed different rice genomic DNA fragments. Northern blot analysis also confirmed that a 1.1‐kb RNA detectable by the TLP cDNA inserts was induced by fungal infection. Thus rice TLPs are encoded by a family of at least three genes which are differentially expressed in responses to bacterial or fungal pathogens.