bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Actinobacillus actinomycetemcomitans leukotoxicity by bacteria from the subgingival flora
Authors: Johansson A. , Hänström L. , Kalfas S.
Published: March 2003

Actinobacillus actinomycetemcomitans produces a pore‐forming leukotoxin that lyses human polymorphonuclear leukocytes and monocytes. Certain proteolytic bacteria may coexist with A. actinomycetemcomitans in periodontal pockets. We aimed therefore to examine whether oral bacteria can modify the leukotoxicity of A. actinomycetemcomitans. A total of 55 strains representing 45 bacterial species of the subgingival flora were tested. Each strain was incubated with the highly toxic strain of A. actinomycetemcomitans HK 1519 and the leukotoxic activity of the suspension against human polymorphonuclear leukocytes was determined from the activity of the lactate dehydrogenase released upon lysis of the leukocytes. Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Prevotella melaninogenica and Prevotella loeschii inhibited the leukotoxicity of A. actinomycetemcomitans cells as well as the activity of leukotoxin purified from the same strain. The bacterial strains without the ability to block leukotoxic activity also failed to destroy pure leukotoxin even after 5 h of incubation. The proteolytic degradation of leukotoxin by P. gingivalis was mainly dependent on the activity of the enzymes R‐ and K‐gingipains. P. intermedia and P. nigrescens also degraded the leukotoxin by enzymes. The results imply a role of the periodontal microflora in modifying the virulence of A. actinomycetemcomitans by destroying its leukotoxin.
Sensitivity of Actinobacillus actinomycetemcomitans and Capnocytophaga spp. to the bactericidal action of LL‐37: a cathelicidin found in human leukocytes and epithelium
Authors: Tanaka D. , Miyasaki K. T. , Lehrer R. I.
Published: March 2003

The bactericidal activity of synthetic LL‐37, a cathelicidin, was assessed against Actinobacillus actinomycetemcomitans (three strains) and Capnocytophaga spp. (three strains). All strains were sensitive to LL‐37, and exhibited 99% effective dose of 7.5‐to‐11.6 μg/ml. An amidated form of LL‐37, pentamide‐37, killed with about the same efficacy as LL‐37. Partial inhibition of killing was noted at physiologic concentrations of NaCl, and complete inhibition was observed at 400 mM NaCl. At approximately the 99% effective dose – i.e., 10 μg/ml – LL‐37 also lost activity against A. actinomycetemcomitans in the presence of native or heat‐inactivated 10–15% normal human AB serum. Pentamide‐37 was less sensitive to serum inhibition than LL‐37. In conclusion, certain oral, gram‐negative bacteria are sensitive to the bactericidal activity of LL‐37 at low concentrations of serum and salt, a condition likely to be found within the membrane‐delimited phagolysosome. Modified forms of LL‐37, such as pentamide‐37, may be more suitable for future therapeutic application in the presence of serum.
Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and bacterial heat shock proteins
Authors: Ishihara K. , Ando T. , Kosugi M. , Kato T. , Morimoto M. , Yamane G. , Takahashi S. , Ogiuchi H. , Okuda K.
Published: March 2003

Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and heat shock proteins were studied by using enzyme‐linked immunosorbent assay to examine levels of immunoglobulin G (IgG) against Escherichia coli GroEL, a recombinant DnaJ of Actinobacillus actinomycetemcomitans heat shock protein, a synthetic peptide made from the 180th to the 188th amino acids of Mycobacterium bovis BCG Hsp65, and a recombinant human Hsp60, in sera obtained from 43 pustulosis palmaris et plantaris patients judged to have chronic infectious diseases of the oral cavity. We found that the titers of IgG against E. coli GroEL and A. actinomycetemcomitans DnaJ in the sera from pustulosis palmaris et plantaris patients were significantly higher than those in the control group, whereas the titers of IgG against the synthetic M. bovis Hsp65 and the recombinant Hsp60 did not differ significantly. Periodontal therapy and extraction of teeth with periapical infectious resulted in remission of pustulosis palmaris et plantaris and a statistically significant reduction in the levels of IgG against E. coli GroEL in 9 of the 22 patients (41%) examined. We also found that the IgG levels against A. actinomycetemcomitans DnaJ in 6 serum samples of 16 (37%) were reduced, but not significantly, after the treatment. These results suggest that the IgG responses to heat shock proteins partially induced by oral bacteria may be related to the onset of pustulosis palmaris et plantaris in some patients.
Two distinct hemolysins in Trichomonas tenax ATCC 30207
Authors: Nagao E. , Yamamoto A. , Igarashi T. , Goto N. , Sasa R.
Published: March 2003

An oral protist Trichomonas tenax ATCC 30207 was investigated for the ability to lyse erythrocytes of sheep, rabbits, horses and humans. Five fractions, including intact cells, culture supernatant, culture filtrate, cell debris and lipid‐enriched fractions, were prepared from the protozoan cells, and their hemolytic activities were assayed under various conditions. All the samples except culture supernatant had hemolytic activities, which were due to two different kinds of hemolysins. One hemolysin was protein‐like and mainly found in cell‐free fractions: culture supernatant and culture filtrate. It was heat‐labile and inhibited by various cysteine‐proteinase inhibitors. The other hemolysin was lipid‐like and found in cell‐associated fractions: intact cells, cell‐debris and lipid‐enriched fractions. It was heat‐stable, organic solvent–tolerant and unaffected by various proteinase inhibitors and stimulators. These results suggested that T. tenax ATCC 30207 possessed two distinct hemolysins, protein and lipid.
Typing of herpes simplex virus from human periodontium
Authors: Contreras A. , Slots J.
Published: March 2003

Herpes simplex virus (HSV) is frequently detected in gingival crevicular fluid and in gingival biopsies of periodontal lesions; however, the relative occurrence of HSV type 1 and 2 in periodontal specimens has not been established. This investigation used type‐specific polymerase chain reaction (PCR) to detect the presence of HSV‐1 and HSV‐2 in periodontal pocket samples from 26 patients who had previously been revealed to have periodontal HSV by PCR amplification of a gene shared by HSV‐1 and HSV‐2. HSV‐1 was detected in all 26 periodontal pocket specimens and HSV‐2 was not detected. Apparently, HSV‐2 is a rare inhabitant of periodontal sites.
Prior exposure of mice to Fusobacterium nucleatum modulates host response to Porphyromonas gingivalis
Authors: Choi J. , Borrello M. A. , Smith E. , Cutler C. W. , Sojar H. , Zauderer M.
Published: March 2003

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T‐ and B‐lymphocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate the immunomodulatory effect of exposure to Fusobacterium nucleatum prior to Porphyromonas gingivalis. Group 1 (control) mice were immunized with phosphate‐buffered saline, group 2 were immunized with F. nucleatum prior to P. gingivalis and group 3 were immunized with P. gingivalis alone. All the T‐cell clones derived from group 2 demonstrated type 2 helper T‐cell clone (Th2 subsets), whereas those from group 3 mice demonstrated Th1 subsets. Exposure of mice to F. nucleatum prior to P. gingivalis interfered with the opsonophagocytosis function of sera against P. gingivalis. In adoptive T‐cell transfer experiments, in vivo protective capacity of type 2 helper T‐cell clones (Th2) from group 2 was significantly lower than type 1 helper T‐cell clones (Th1) from group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated a different pattern of recognition of P. gingivalis fimbrial proteins between sera from group 2 and group 3. In conclusion, these studies suggest that exposure of a host to F. nucleatum prior to the periodontal pathogen P. gingivalis modulates the host immune responses to P. gingivalis at the humoral, cellular and molecular levels.
Isolation of the provisionally named Desulfovibrio fairfieldensis from human periodontal pockets
Authors: Loubinoux J. , Bisson‐Boutelliez C. , Miller N. , Le Faou A. E.
Published: March 2003

Sulfate‐reducing bacteria have recently been associated with periodontitis and proposed to play a role in the pathogenesis of this chronic inflammatory process. Eight isolates of sulfate‐reducing bacteria belonging to the genus Desulfovibrio were obtained from the periodontal pockets of five out of seven patients presenting with active periodontitis. A multiplex PCR was devised for their identification at the species level. All isolates were identified as Desulfovibrio fairfieldensis, a recently proposed new species. This finding reinforces the suggestion that Desulfovibrio fairfieldensis is a human bacterium that may present a pathogenic potential.
The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study: Design and first results
Authors: Brunekreef Bert , Smit Jet , De Jongste Johan , Neijens Herman , Gerritsen Jorrit , Postma Dirkje , Aalberse Rob , Koopman Laurens , Kerkhof Marjan , Wijga Alet , Van Strien Rob
Published: March 2003

The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study was initiated in 1996. Children born to allergic mothers were enrolled in a double‐blind placebo‐controlled trial for evaluating the use of mite‐impermeable mattress and pillow covers. Children born to allergic and non‐allergic mothers were enrolled in a ‘natural history’ study to assess the role of environmental and dietary risk factors for the development of allergic disease in childhood. Recruitment started by distributing a validated screening questionnaire among >10,000 pregnant women during their first visit to a prenatal health clinic. Allergic mothers‐to‐be were invited to participate in the intervention study. Allergic, and a random sample of non‐allergic, mothers‐to‐be were invited to participate in the ‘natural history’ arm of the study. In the intervention study, homes were visited before birth, 3 months after birth, and 12 months after birth for the collection of dust samples from floors and mattresses. In addition, the homes of about one‐third of the children in the ‘natural history’ part of the study were visited for dust collection when the children were 3 months of age. The intervention study started with 855 participants and the ‘natural history’ study with 3,291 participants. Follow‐up at 3 years of age has now been completed with satisfactory compliance (>90%). A medical investigation and home visit at 4 years of age are nearing completion. Preliminary results show that mite‐allergen levels were lower than found in previous Dutch studies, and that the intervention measure had a significant effect on mite‐allergen levels, without important clinical benefits up to age 2 years old. The allergic families lived in homes with fewer ‘triggers’ such as pets, smoking and carpets than the non‐allergic families, regardless of the intervention. The ongoing PIAMA cohort study will probably reveal useful information concerning effects of allergen load and reduction in the setting of a relatively low mite‐allergen exposure, as well as other variables on the development of allergic manifestions and asthma.
Dust mite allergens are carried on not only large particles
Authors: Custovic Adnan , Woodcock Hannah , Craven Mark , Hassall Rebecca , Hadley Elizabeth , Simpson Angela , Woodcock Ashley
Published: March 2003

The major obstacle for the successful measurement of airborne mite allergen is its very low concentration in the absence of vigorous disturbance. The aim of this study was to investigate the particle size distribution of group 2 dust mite allergen using an amplified ELISA system. Air sampling was performed using an Andersen sampler placed in the centre of the room, 1.2 m above floor level (airflow rate28.7 l/min). This is a multistage, multiorifice cascade impactor that is comprised of six stages. Any particle greater that 4.7 μm should impact on stages 1 and 2, whilst stages 3–6 measure the predominantly respiratory range. The sampling was carried out for 30 min after 15 min of vigorous disturbance (vacuum cleaning without bag and filter). Der p 2 was measured using mAb‐based ELISA with the AmpliQ amplification kit (Dako Ltd, Cambridgeshire, UK). The sensitivity was increased ˜15‐fold as compared with standard assay, bringing the level of detection to 300 pg/ml. The majority of airborne Der p 2 (79.4%) was carried on large particles (> 4.7 µm). However, a small but important proportion of airborne Der p 2 (20.6%) was associated with small particles(1.1–4.7 µm). It is worth noting that all the levels measured were below the detection limit of standard assay. In conclusion, we have shown that using an amplification system, airborne mite allergen previously undetectable owing to its low concentration can be quantified. Group 2 dust mite allergen is carried not only on large particles. A small, but potentially significant proportion of this airborne allergen is associated with small particles which, when inhaled, may penetrate deep into the human respiratory tract.
Efficacy and safety of inhaled steroid and cromone treatment in school‐age children:  A randomized pragmatic pilot study
Authors: Kannisto Senja , Voutilainen Raimo , Remes Kyllikki , Korppi Matti
Published: March 2003

In the treatment of asthma, inhaled steroids are more effective than cromolyn, whereas the latter offers extreme safety. The aim of the present pilot study was to evaluate, contemporarily, efficacy and safety aspects of different asthma treatment modalities. In 75 school‐age children (mean age 9.5 years; range 5.5–14.7 years), treatment of asthma was started with budesonide (BUD, n = 30), fluticasone propionate (FP, n = 30) or cromones (CROM, n = 15). BUD was used at a dose of 800 µg/day during the first 2 months and at 400 µg/day thereafter. The respective FP doses were 500 and 200 µg/day. Efficacy of the treatment was assessed by measuring forced expiratory volume in 1 second (FEV1) and by evaluating the use of bronchodilators. Side‐effects of the treatment were evaluated by following growth of the children and by performing low‐dose adrenocorticotropin (ACTH) testing. At 4 months FEV1 had improved by a mean of 8.2% in the BUD group and by 5.4% in the FP group (p< 0.01 vs. baseline in both groups; NS between BUD and FP groups). The use of bronchodilators had decreased from five doses/week to one dose/week in the BUD group (p< 0.05), and from three doses/week to one dose/week in the FP group (p< 0.01) (NS between the groups). In the CROM group, the FEV1 value and the use of bronchodilators did not change. The treatment was unsuccessful on the basis of FEV1 decrease and increased bronchodilator use in, respectively, 30 and 15% of the BUD‐, 20 and 7% of the FP‐, and 50 and 47% of the CROM‐treated children. Therefore, to prevent one treatment failure in the CROM group, between three and five children would need to move to treatment with steroids. The treatment had measurable systemic effects on the basis of height standard deviation (SD) score decrease and minor adrenocortical suppression in, respectively, 60 and 30% of the BUD‐, 27 and 17% of the FP‐, and 20 and 0% of the CROM‐treated children. Therefore, to avoid systemic effects in one steroid‐treated child, three BUD‐ and six to 14 FP‐treated children would need to move to treatment with CROM. In conclusion, in school‐age children asthma should be treated first with inhaled steroids. It is probable that the best combination of efficacy and safety can be achieved by using low steroid doses.
Hypertonic saline challenge tests in the diagnosis of bronchial hyperresponsiveness and asthma in children
Authors: Mai Xiao‐Mei , Nilsson Lennart , Kjellman N‐I Max , Björkstén Bengt
Published: March 2003

The hypertonic saline challenge test is the recommended method to assess bronchial hyperresponsiveness in the International Study of Asthma and Allergies in Childhood (ISAAC). The sensitivity of this procedure to assess asthma symptoms, however, has been reported to vary among study centers. The purpose of our study was to evaluate the value of this provocation test in an epidemiological survey in children, and to relate the degree of bronchial hyperresponsiveness to the severity of asthma symptoms. All 11–13‐year‐old children from 16 randomly selected schools in Linköping, Sweden received a questionnaire regarding respiratory symptoms and allergic disease. Skin prick tests with eight inhalant allergens were performed. In addition, all children with wheeze over the past 12 months (current wheeze) and a random sample of children without current wheeze were invited to perform hypertonic saline provocation tests. A complete data set was available for 170 children, including 50 with and 120 without current wheeze. Bronchial hyperresponsiveness (BHR) was defined as at least 15% decline in FEV1. The degree of BHR was represented by the response/dose ratio, i.e. the fall in FEV1 divided by total dose of inhaled saline. The severity of asthma symptoms was classified by the number of wheezing episodes over the past 12 months. ‘Asthma ever’ was defined by a combination of symptoms in the questionnaires. Children with ‘asthma ever’ and current wheeze were considered as having current asthma. Current atopic asthma was defined as current asthma with at least one positive skin prick test. The sensitivity of the procedure to detect ‘asthma ever’, current asthma and current atopic asthma was 62, 61 and 83%, and the specificity 83, 81 and 60%, respectively. The positive challenge rate was 52, 34, 13 and 7% among current wheezers, previous wheezers, non‐wheezers with a history of allergy and healthy children. The degree of bronchial hyperresponsiveness increased with the number of wheezing episodes. Thus, the median and range of the response/dose ratio were 4.8%/ml (2.1–14.8), 2.6%/ml (0.7–8.6) and 1.3%/ml (0.8–2.7), respectively, for children with ≥ 4 episodes, 1–3 episodes and no wheezing episodes over the past 12 months (p<0.001). In conclusion, hypertonic saline provocation test is useful as a tool to detect asthma in epidemiological studies in children. The degree of bronchial hyperresponsiveness, as represented by the response/dose ratio, reflects the severity of asthma symptoms.
The 1997 Annual Renal Transplantation in Children Report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS)
Authors: Benfield M. R. , McDonald R. , Sullivan E. K. , Stablein D. M. , Tejani A.
Published: March 2003

Abstract: This report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS), covering the years 1987–96 (January 15, 1997), analyzed data on 4898 patients who received 5362 transplants. Over the 10 yr of the study, 21.3% of the patients were under the age of 6 yr. Of the disorders that lead to end‐stage renal disease (ESRD), structural and developmental anomalies of aplasia, dysplasia, and obstructive uropathy accounted for over 1500 patients. Despite the potential therapies for focal segmental glomerulosclerosis (FSGS), there has been little change in its incidence and this lesion continues to be the most common cause of renal failure and transplantation among acquired diseases. Eighty‐nine per cent of patients with a functioning graft continue to receive cyclosporin A (CsA) 5 yr post‐transplantation, and 84% of patients continue to receive azathioprine (AZA), whereas 26% of patients receive alternate‐day steroid therapy at 4 yr post‐transplant. Thirty‐seven per cent of the living donor (LD) recipients and 47% of cadaver donor (CD) recipients were treated with the polyclonal T‐cell antibody ATG/ALG for induction, and the monoclonal T‐cell antibody, OKT3, was utilized for induction in 12% of LD patients and in 19% of CD patients. Twenty‐five per cent of the 5362 transplants (1333) have failed over the 10‐yr period. Graft survival is 90% at 1 yr and 74% at 6 yr for LD kidneys, and is 80% at 1 yr and 58% at 6 yr for CD patients. The most common cause for graft failure (30%) is chronic rejection. For recipients of LD grafts, relative risk (RR) factors for graft survival are African–American race (RR = 2.1, p<0.001) and greater than five prior transfusions (RR = 1.6, p<0.001). Prophylactic anti‐T‐cell antibody reduces the risk of graft failure (RR = 0.76, p=0.009). For recipients of cadaver kidneys, risk factors are: recipient age < 2 yr (RR = 2, p<0.001), donor age < 6 yr (RR = 1.3, p=0.005), and absence of induction T‐cell antibody (RR = 1.31, p<0.001).
Current understanding of chemokine involvement in allograft transplantation
Authors: Melter M. , McMahon G. , Fang J. , Ganz P. , Briscoe D. M.
Published: March 2003

Abstract: Multiple studies have demonstrated that chemokines play an essential role in regulating and co‐ordinating the infiltration of leucocytes into allografts. Chemokines are expressed in skin, liver, heart, and kidney allografts following initial engraftment, ischemic injury, viral infection, and acute and chronic rejection. To date, most of our understanding of chemokine biology has been generated from studies of animal models of transplantation and little is known about the role of chemokines in human allograft rejection. Chemokines may play important mechanistic roles in transplant rejection, in the development of graft arteriosclerosis, and in chronic sclerosing cholangiopathy. Furthermore, these molecules may serve as sensitive diagnostic indicators for the analysis of rejection, including chronic rejection or other forms of graft dysfunction. Lastly, it is possible that chemokine‐targeted therapy might become a feasible option for the treatment of allograft rejection.
Limited sampling model for area‐under‐the‐curve monitoring in pediatric patients receiving either Sandimmune® or Neoral® cyclosporin A oral formulations
Authors: Medeiros M , Pérez‐urizar J , Muñoz Ar , Castañeda‐hernández G
Published: March 2003

Abstract: Several limited sampling equations were tested to predict the area under the curve (AUC) of cyclosporin A (CsA) at steady state in 10 children with end‐stage renal disease receiving oral CsA 2.5 mg/kg b.i.d. as two different formulations, namely Sandimmune® and Neoral®, according to a randomized crossover design with a one‐month washout period. AUC was significantly correlated with CsA concentration at 5 h. The equation derived from this single concentration–time point was able to adequately predict the AUC for Sandimmune but not for Neoral. The equation derived from CsA concentration data, measured at 2 and 12 h, significantly improved predictive performance in terms of bias and precision, allowing adequate AUC predictions in both formulations. CsA concentration at 2 h was also able to predict Cmax, while the concentration at 12 h corresponded to the trough value in a b.i.d. dosing scheme. Therefore, it is concluded that a limited sampling model including concentration data at 2 and 12 h allows the estimation of AUC, Cmax and trough levels, yielding a complete profile in patients exposed to CsA as Sandimmune or Neoral. Hence, this model can be used for therapeutic monitoring of CsA levels in pediatric patients being switched from one formulation to another.
Post‐transplant immunotherapy designed to prevent cancer recurrence*
Authors: Sondel Paul M.
Published: March 2003

Abstract: Most stem cell transplants are performed to treat neoplasms. Yet many patients survive the transplant but die from cancer recurrence post‐transplant. The incorporation of post‐transplant immunotherapy offers the potential for enhanced antitumor efficacy.
Sirolimus in pediatric gastrointestinal transplantation: The use of sirolimus for pediatric transplant patients with tacrolimus‐related cardiomyopathy
Authors: Pappas Peter A. , Weppler Debbie , Pinna Antonio D. , Rusconi Paolo , Thompson John K. , Jaffe Jonathan , Tzakis Andreas G.
Published: March 2003

Abstract: Hypertrophic obstructive cardiomyopathy (HOCM) associated with the use of tacrolimus is a rare complication of liver and intestinal transplantation seen almost exclusively among pediatric patients. Reduction of tacrolimus dosage or conversion to cyclosporin A (CsA) has been used as an effective treatment in reviewed cases. We present three pediatric transplant recipients who developed hypertrophic obstructive cardiomyopathy while under tacrolimus immunosuppression and were treated with conversion to sirolimus (Rapamycin®). The patients (ages 6 yr, 12 yr and 11 months) were transplant recipients (liver, n = 2; liver and intestine, n = 1) who developed significant cardiomyopathy 15 and 96 months post‐transplant. One patient died of post‐transplant lymphoproliferative disorder 21 days after starting sirolimus. One patient had received two liver transplants and had been on CsA for 12 yr before conversion to tacrolimus at 60 months post‐transplant for acute and chronic rejection. The surviving patients were receiving mycophenolate mofetil, tacrolimus and steroids at the time of diagnosis. Dose reduction of tacrolimus and treatment with beta blockers failed to alleviate the hemodynamic changes. The patients were converted to sirolimus 1.6, 37 and 148 months post‐transplant and maintained a whole‐blood trough level of 15–20 ng/mL 21 days after starting sirolimus. Repeat echocardiograms in the surviving patients showed improvement in cardiomyopathy. One patient had one rejection episode (intestinal biopsy, mild acute cellular rejection) after starting sirolimus that responded to a transient increase in steroids. The early demise of the third patient after sirolimus conversion prevented an adequate assessment of cardiomyopathy. Conversion to sirolimus was associated with a reduction in the cardiomyopathy of the two surviving patients while still providing effective immunosuppression. To our knowledge this observation has not been previously reported.
Allograft with unrelated donor accentuates the gastrointestinal toxicity associated with high‐dose melphalan and total body irradiation preparative for bone marrow transplantation in children
Authors: Vettenranta K. , Hovi L. , Taskinen M. , Saarinen‐Pihkala U.
Published: March 2003

Abstract: The use of high‐dose melphalan (
l‐phenyalalanine mustard or
l‐PAM) has been shown to be associated with both hematological and non‐hematological toxicity. It has been employed in the conditioning for allogeneic stem cell transplants from related donors but experience on its use in the unrelated setting has not been reported. As an attempt to elucidate the role of high‐dose
l‐PAM (210 mg/m2) and total body irradiation (TBI) as a preparative regimen for allogeneic marrow transplantation from matched unrelated donors, they were employed in an institutional pilot series of seven pediatric patients. When compared with recipients of unrelated marrow grafts conditioned using other regimens, those treated with high‐dose
l‐PAM experienced a markedly more severe acute graft‐vs.‐host disease (GvHD). The overall incidence of grade III–IV acute GvHD was higher (86% vs. 14%) among those treated with
l‐PAM. As judged by gastrointestinal (GI) symptoms, clinically significant (stages ++ to ++++) gut GvHD was strikingly more prevalent among those treated with
l‐PAM (86% vs. 9%, p<0.005). Toxic mortality prior to day +100 was 29% in the
l‐PAM group and 9% in the non‐
l‐PAM group of patients. With a mean follow‐up of 21 months no increase in the incidence of chronic GvHD has been encountered among those conditioned with
l‐PAM. We conclude that the use of preparative
L‐PAM for allogeneic transplants from unrelated donors is associated with considerable procedure‐related toxicity. We strongly suggest its use in this setting to be viewed with caution.
Single‐center analysis of early recurrence of nephrotic syndrome following renal transplantation in children
Authors: Schachter Asher D. , Harmon William E.
Published: March 2003

Abstract: Recurrence of nephrotic syndrome (NS) after transplantation (Tx) occurs in 20–50% of renal transplant recipients, with a median time to recurrence of 14 days and a 50% rate of graft loss. We performed a retrospective analysis of 22 pediatric patients with NS who received renal transplants at the Children's Hospital, Boston, between 1982 and 1999. During the first 14 days following Tx, 13 (59%) patients developed clinical recurrent nephrotic syndrome (RNS). RNS developed in 50% of living donor recipients and in 70% of cadaveric donor recipients (p= non‐significant). Seven of the 13 patients with RNS were treated with plasmapheresis, while six received standard immunosuppressive induction therapy only. Two of the seven treated patients and one of the six untreated patients lost their grafts to RNS, yielding a total RNS graft loss rate of 23%. However, patients with RNS who achieved remission had significantly higher cumulative graft survival at 5 yr than did RNS patients who did not achieve remission (p< 0.001). Overall cumulative graft survival at 5 yr was not significantly different between the two groups: 67% in those with non‐recurrent nephrotic syndrome (NRNS) vs. 64% in those with RNS, p= non‐significant. We conclude that successful reversal of early RNS improves long‐term graft survival in pediatric RNS. Multi‐center studies are sorely needed to develop novel, less toxic therapies for native and recurrent NS.
Eight‐year experience of pediatric heart transplantation: Clinical outcome using  non‐invasive methods for the evaluation  of acute rejection
Authors: Azeka Estela , Marcial Miguel Barbero , Jatene Marcelo , Auler José Otávio Costa , Ramires José Antônio Franchini
Published: March 2003

Abstract: Combined immunosuppression therapy and acute rejection surveillance after heart transplantation may influence clinical outcome. This prospective, longitudinal study investigated 27 pediatric patients (12 days to 12 yr of age; mean 3.0 yr) who underwent a post‐operative regimen that included long‐term treatment with cyclosporin A and azathioprine (double immunosuppression) and polyclonal anti‐thymocyte serum induction therapy. Non‐invasive parameters were used to diagnose acute rejection. The actuarial survival, clinical outcomes, and complications were analyzed. The actuarial survival after double immunosuppression and induction therapy with polyclonal anti‐thymocyte serum was 89%, 73%, and 57% at 1, 4, and 8 yr, respectively. The rejection frequency was 2.6 episodes/patient and the infection frequency, 3.7 episodes/patient. One year after transplantation, systemic arterial hypertension was detected in 21% of patients. Hence, double immunosuppression with polyclonal anti‐thymocyte serum induction therapy combined with surveillance of acute rejection with non‐invasive tests may provide promising clinical outcome in pediatric heart transplant recipients.
Bone marrow stem cells regenerate infarcted myocardium
Authors: Orlic Donald , Kajstura Jan , Chimenti Stefano , Bodine David M. , Leri Annarosa , Anversa Piero
Published: March 2003

Abstract: Heart disease is the leading cause of death in the United States for both men and women. Nearly 50% of all cardiovascular deaths result from coronary artery disease. Occlusion of the left coronary artery leads to ischemia, infarction, necrosis of the affected myocardial tissue followed by scar formation and loss of function. Although myocytes in the surviving myocardium undergo hypertrophy and cell division occurs in the border area of the dead tissue, myocardial infarcts do not regenerate and eventually result in the death of the individual. Numerous attempts have been made to repair damaged myocardium in animal models and in humans. Bone marrow stem cells (BMSC) retain the ability throughout adult life to self‐renew and differentiate into cells of all blood lineages. These adult BMSC have recently been shown to have the capacity to differentiate into multiple specific cell types in tissues other than bone marrow. Our research is focused on the capacity of BMSC to form new cardiac myocytes and coronary vessels following an induced myocardial infarct in adult mice. In this paper we will review the data we have previously published from studies on the regenerative capacity of BMSC in acute ischemic myocardial injury. In one experiment donor BMSC were injected directly into the healthy myocardium adjacent to the injured area of the left ventricle. In the second experiment, mice were treated with cytokines to mobilize their BMSC into the circulation on the theory that the stem cells would traffic to the myocardial infarct. In both experimental protocols, the BMSC gave rise to new cardiac myocytes and coronary blood vessels. This BMSC‐derived myocardial regeneration resulted in improved cardiac function and survival.
The effects of GA3 and divalent cations on aspects of pectin metabolism and tissue softening in ripening tomato pericarp
Authors: Mignani Ilaria , Greve L. Carl , Ben‐Arie Ruth , Stotz Henrik U. , Li Chingying , Shackel Ken A. , Labavitch John M.
Published: March 2003

The ripening of discs cut from the pericarp of green tomato (Lycopersicon esculentum Mill.) fruits is inhibited by treatments with GA3 and several divalent cations, including calcium. Normal ripening is marked by an increase in the solubility of wall pectins. Calcium and GA3 alter the pattern of pectin solubility changes. In part this may be because polygalacturonase synthesis and/or secretion to the apoplast is reduced. The impact of divalent cations on ripening‐related tissue softening appears to have a nonmetabolic component. Ripening‐inhibiting ions rapidly reduce tissue softening, pectin solubilization and the normal ripening‐related decrease in cellular turgor.
Bioenergetic processes in guard cells related to stomatal function
Authors: Parvathi K. , Raghavendra A. S.
Published: March 2003

The energy required for ion uptake in guard cells is provided by two important bioenergetic processes, namely respiration and photosynthesis. The blue light‐sensitive plasma membrane redox system is considered as the third bioenergetic phenomenon, since it uses blue light to create a proton gradient across the membrane. The unique features of respiration and photosynthesis in guard cells and their role in stomatal function are emphasized. Evidence for and against the blue light‐sensitive components on plasma membrane (ATPase/distinct redox chain) and the photoreceptors (flavins, carotenoids, pterins) in guard cells are presented. The information on ion channels and their response to various kinds of secondary messengers including G‐proteins, phosphoinositides, diacylglycerol, calcium, cAMP and protein kinases are reviewed. A model is presented indicating the possible mechanism of perception and transduction by guard cells of external signals and their interaction with different bioenergetic components.
Asparagine catabolism in bryophytes: Purification and characterization of two L‐asparaginase isoforms from Sphagnum fallax
Authors: Heeschen Volker , Matlok Johannes , Schrader Silke , Rudolph Hansjörg
Published: March 2003

Nitrogen represents a critical nutrient in raised bogs. In Sphagna, dominating this habitat, the prevalent storage amino acid asparagine is catabolized predominantly by the enzyme L‐asparaginase (EC 3.5.1.1). L‐asparaginase activity has been detected in each of 10 Sphagnum species investigated. In Sphagnum fallax Klinggr. (Klinggr. clone 1) cultivated under axenie conditions in continuous feed bioreactors, the enzyme displayed a light dependent increase in activity. We separated two isoforms, designated L‐asparaginase 1 and 2, characterized by their different elution patterns from an anion‐exchange column. In stem segments only L‐asparaginase 2 could be detected, whereas in capitulae L‐asparaginase 1 represented the dominating isoform. Purified chloroplasts displayed no L‐asparaginase activity. Almost the entire activity was located in the cytosohc fraction. L‐asparaginase 1 and 2 have been purified 82‐fold and 188‐fold, respectively, by ion‐exchange, size‐exclusion and hydrophobic interaction chrornatography. Identical pH optima (8.2) and molecular weights (126 000) were determined. The Km values for asparagine (7.4 mM for L‐asparaginase 1 and 6.2 mM for L‐asparaginase 2) were in the range of those described for higher plants. On the other hand Sphagnum L‐asparaginase is comprised of four subunits as are the L‐asparaginases of microorganisms. So, the characteristics of the bryophyte enzyme appear to be intermediate between those from higher plants and those from microorganisms.
Boric acid stimulates the plasma membrane H+‐ATPase of ungerminated lily pollen grains
Authors: Obermeyer Gerhard , Kriechbaumer Rosa , Strasser Doris , Maschessnig Angela , Bentrup Friedrich‐Wilhelm
Published: March 2003

The stimulation of the plasma membrane (PM) H+‐ATPase by boric acid was studied on a microsomal fraction (MF) obtained from ungerminated, boron‐dependent pollen grains of Lilium longiflorum Thunb. which usually need boron for germination and tube growth. ATP hydrolysis and H+ transport activity increased by 14 and 18%, respectively, after addition of 2‐4 mM boric acid. The optimum of boron stimulation was at pH 6.5‐8.5 for ATP hydrolysis and at pH 6.5‐7.5 for H+ transport. No boron stimulation was detected when vanadate was added to the MF, whereas an increase of 10‐20% in ATP hydrolysis and H+ transport was still measured in the presence of inhibitors specific for V ‐type ATPase (nitrate and bafilomycin) and F‐type ATPase (azide), respectively. A vanadate‐sensitive increase in ATP hydrolysis activity was also observed in partially permeabilized vesicles (0.001%[w/v] Triton X‐100) suggesting a direct interaction between borate and the PM H+‐ATPase rather than a weak acid‐induced stimulation. Additionally, we measured the effect of boron on membrane voltage (Vm) of ungerminated pollen grains and observed small hyperpolarizations in 48% of all experiments. Exposing pollen grains to a more acidic pH of 4 caused a depolarization, followed in some experiments by a repolarization (21%). In the presence of 2 mM boron such hyperpolarizations, perhaps caused by an enhanced activity of the H+‐ATPase, were measured in 58% of all tested pollen grains. The effects of boron on Vm may be reduced by additional stimulation of a K+ inward current of opposite direction to the H+‐ATPase. All experiments indicate that boron stimulates an electrogenic transport system in the plasma membrane which is sensitive to vanadate and has a pH optimum around 7, i.e. the plasma membrane H+‐ATPase. A boron‐increased PM H+‐ATPase activity in turn may stimulate germination and growth of pollen tubes.
Temporal and spatial pattern of the biochemical activation of the endosperm during and following imbibition of tomato seeds
Authors: Nonogaki Hiroyuki , Nomaguchi Masako , Okumoto Nand , Kaneko Yasuko , Matsushima Hisashi , Morohashi Yukio
Published: March 2003

Electron microscopic observations of the endosperm of tomato (Lycopersicon esculentum Mill.) seeds revealed that changes in the cell wall structures along with the vacuolation of protein bodies occurred in the micropylar portion of the endosperm prior to germination. No changes were detected at that time in the rest of the endosperm. Endo‐β‐mannanase activity was restricted to the micropylar region of the endosperm prior to germination. Cell wall digestion by this pregerminative mannanase seemed to be associated with the changes in cell wall structures occurring in the micropylar region prior to germination. The protein content in the micropylar part of the endosperm began to decrease shortly after imbibition and attained about 40% of the initial level by the time of radicle protrusion (38 h after imbibition). On the other hand, only slight changes in the content were detected in the lateral endosperm during the same time; the protein content in the lateral endosperm decreased only after germination started. In conformity with the results on protein contents, proteolytic activity began to develop first in the micropylar portion prior to germination, and then in the lateral portion after germination. Thus, the timing of the biochemical activation of the endosperm after imbibition differed between the micropylar and the lateral region. Some qualitative differences in patterns of polypeptides synthesized in vivo were detected, as analyzed by pulse‐labeling and fluorography, between the micropylar and the lateral portions of the endosperm of seeds imbibed for 25 h. This suggests that processes of the biochemical activation of the endosperm may be qualitatively, as well as quantitatively, different depending on the regions of the endosperm.
Photoperiodic control of growth, development and phytohormone balance in Solanum tuberosum
Authors: Macháčková Ivana , Konstantinova Tatyana N. , Sergeeva Lidiya I. , Lozhnikova Veronika N. , Golyanovskaya Svetlana A. , Dudko Natalia D. , Eder Josef , Aksenova Nina P.
Published: March 2003

Some lines of Solanum tuberosum ssp. andigena are strictly photoperiodic, forming tubers only in short days and flowers only in long days. We used this advantageous phenomenon to study phytohormone involvement in the development of the plants, mainly that of tuber formation. Plants grown for 2 months under short days (SD) of 14 h darkness, night break (1 h white light in the middle of the 14‐h dark period) and continuous light (LD) were compared. Short day‐grown plants formed tubers, while plants in LD flowered. Night break prevented tuber formation, but caused flowering, although it was weaker than in LD. Plants grown under night break displayed many growth characteristics intermediate between SD and LD. Under LD and night break regimes ABA levels in all organs were about one‐fourth of those under SD. An opposite trend was found for gibberellin content: it was very low in SD‐grown plants and 4‐10 times higher under both other conditions with the exception of roots and stolons in night break. Thus, the ratio of ABA/GA, known to be important for tuber formation, was high in SD and low in night break and LD. The level of free indoleacetic acid (IAA) was high in LD‐ and night break‐grown plants and it was much lower in SD‐grown plants, including tubers. Cytokinin (CK) levels were also high in LD‐ and night break‐grown plants. In SD, leaves had slightly decreased and stems and roots + stolons had more pronouncedly decreased cytokinin levels. The CK/IAA ratio was thus higher in SD in stems and roots + stolons; it was also high in tubers and no difference was found in leaves. These results indicate that the effect of photoperiod on tuber formation and development may be mediated by photoperiod‐induced changes in hormone levels.
Aluminium accumulation in root cell walls coincides with inhibition of root growth but not with inhibition of magnesium uptake in Norway spruce
Authors: Godbold D. L. , Jentschke G.
Published: March 2003

High levels of aluminium in the soil solution of forest soils cause stress to forest trees. Within the soil profile, pH and aluminium concentration in the soil solution vary considerably with soil depth. pH strongly influences the speciation of A1 in solution, and is a factor when considering toxicity of A1 to roots. Norway spruce (Picea abies[L.] Karst.) seedlings were grown for 7 weeks in nutrient solutions at pH 3.2, 4.0 or 5.0 containing 0, 100 or 400 µM A1. At the end of this period, seedling growth, the cation exchange capacity of the roots and the amount of exchangeable Ca and Mg in roots were determined. A1 concentrations in whole roots, root segments, and in needles were measured. Using X‐ray microanalysis, the concentrations of Al, Ca, Mg and P were determined in cortical cell walls. We wanted to test the hypotheses that (1) the amount of Al bound to cation exchange sites can be used as a marker for Al toxicity and (2) the Mg concentration of needles is controlled by the amount of Mg bound to cation exchange sites. Low pH reduced the inhibition of Al on root growth and shoot length. Both low pH and Al lowered the concentration of Ca and Mg in needles. Al concentrations in the roots decreased as the pH decreased. In the roots, Al displaced Mg and Ca from binding sites at the root cortical cell walls. A comparison of the effects of Al at the different pH values on root growth and Mg concentration in the needles, suggests that, at pH 5.0, an Al fraction in the apoplast inhibits root growth, but does not affect Mg uptake. This fraction of Al is not available for transport to the shoots. In contrast, Mg uptake is strongly affected by Al at pH 3.2, although only very low levels of Al were detected in the roots. Thus, Al accumulation in the apoplast is a positive marker for Al effects on root growth, but not Mg uptake. The Mg concentration of needles is not controlled by the amount of Mg bound to cation exchange sites.
Gibberellin and phytochrome control senescence in alstroemeria leaves independently
Authors: Kappers Iris F. , Jordi Wilco , Maas Frank M. , Stoopen Geert M. , Van Der Plas Linus H. W.
Published: March 2003

In alstroemeria (Alstroemeria hybrida), leaf senescence is effectively retarded by the application of gibberellins and by low fluences of red light. In this study we examined the possible interaction of gibberellins and red light in the regulation of senescence. Determination of endogenous gibberellins revealed that leaf senescence is accompanied by significant changes in the concentrations of non‐ 13‐hydroxylated gibberellins, the onset of senescence coinciding with a dramatic drop in GA4, whereas concentrations of 13‐hydroxylated gibberellins are far less influenced. However, no direct effect of red light on a specific GA‐metabolic step could be determined. When exogenously applied, non‐13‐hydroxylated GAs were more active than the 13‐hydroxylated GAs. It appeared that the effect of red light is additive to that of active GAs. We hypothesise that GA4 and phytochrome control senescence in alstroemeria mainly through separate mechanisms and have independent effects and that the observed differences in gibberellin concentrations are a consequence of delayed leaf senescence rather than a cause for it.
Cell death caused by a combination of aluminum and iron in cultured tobacco cells
Authors: Ikegawa Hiroshi , Yamamoto Yoko , Matsumoto Hideaki
Published: March 2003

The inhibition of growth of tobacco cells (Nicotiana tabacum L. cv. Samsun) after treatment with A1 in medium containing high concentrations of cations requires the presence of Fe (II or III) during the treatment. We examined whether the inhibition of the post‐treatment growth is due to cell death occurring during the treatment with A1 and Fe. In cells at the end of A1 treatment, the integrity of the plasma membrane and the integrity of the mitochondrial inner membrane were monitored by use of Evans blue staining and the cleavage of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT), respectively. Time‐course and dose‐response experiments indicate that the inhibition of post‐treatment growth is strongly related to Evans blue uptake, but not to MTT cleavage. These results suggest that the loss of integrity of the plasma membrane caused by a combination of Al and Fe directly contributes to cell death and the inhibition of post‐treatment growth.