bluuebunny/crossref_metadata_2025 huggingface dataset:
Complement activation in the nasal mucosa following nasal ragweed‐allergen challenge
Authors: Mezei Györgyi , Varga Lilian , Veres Amarilla , Füst George , Cserháti Endre
Published: March 2003

The aim of this study was to explore complement activation in the nasal lavage following a nasal ragweed‐allergen challenge. The study was carried out with 15 adolescents who were allergic to ragweed and with six non‐allergic healthy volunteers. Following the baseline measurement after the symptoms were registered, subjects were given increasing doses of ragweed allergen. Lavage fluid was collected and tested for a complement‐activation product (C3bBbP). The allergic patients responded to allergen provocation with an increase in C3bBbP formation compared to the initial lavage (p = 0.001). The C3bBbP level remained low in the lavage fluids of the non‐allergic controls. We found a strong correlation between the threshold dose that induced symptoms and the dose where the maximum complement activation was detected (r = 0.78, p = 0.001). Our findings indicate that in allergic patients nasal challenge with ragweed allergen induces a rise in complement activation in the nasal lavage fluid. These results highlight the role of the complement system in the allergic inflammation on the nasal mucosal surface.
Markers of inflammation in the feces of infants with cow's milk allergy
Authors: Saarinen Kristiina Mertta , Sarnesto Annikki , Savilahti Erkki
Published: March 2003

Growing evidence exists that exposure to cow's milk elicits inflammation in the gut of infants with cow's milk allergy, irrespective of symptoms. To demonstrate inflammation and increased protein leakage from the gut during a cow's milk elimination‐challenge test in fecal samples of infants presenting with different symptoms suggestive of cow's milk allergy, we measured the concentrations of α1‐antitrypsin (AT), eosinophil cationic protein (ECP), immunoglobulin (Ig) A, and cow's milk‐specific IgA antibodies, in fecal samples of 208 infants with a mean age of 7 months. Prechallenge samples were collected after a mean 3‐week elimination period, and post‐challenge samples were obtained 4 days after starting the challenge. Fecal levels of prechallenge total IgA (p = 0.02) and post‐challenge AT (p = 0.001) were higher in infants with a positive challenge. Of these infants, pre‐ and post‐challenge levels of ECP were higher in those reacting after 24 h than in those reacting within 1 h (p = 0.006 and p = 0.045). Prechallenge levels of ECP were higher in those showing intestinal symptoms (p = 0.008), and both pre‐ and post‐challenge levels of total IgA were higher in those with an IgE‐mediated reaction to cow's milk (p = 0.04 and p = 0.008). Regardless of the challenge result, total IgA increased during the challenge (p < 0.001 for both challenge‐positive and ‐negative infants) and was higher in those breast‐fed until the challenge than in those fed formula only (p < 0.01). Hence, in infants reacting to the cow's milk challenge, higher prechallenge levels of fecal IgA indicate increased antigenic stimuli in the gut, and higher post‐challenge levels of AT reflect increased protein loss as a result of intestinal inflammation. In infants with slowly evolving gastrointestinal symptoms, increased fecal ECP may help in distinguishing patients from those who tolerate cow's milk. Individual serial follow‐up of fecal IgA and ECP can be used to estimate the degree of inflammation in the gut and an appropriate time for a challenge test, but are not diagnostic tools for cow's milk allergy.
Association of asthma with extra‐respiratory symptoms in schoolchildren: Two cross‐sectional studies 6 years apart
Authors: Ronchetti Roberto , Villa Maria Pia , Matricardi Paolo Maria , La Grutta Stefania , Barreto Mario , Pagani Jacopo , Mortella Susy , Falasca Carlo , Ciofetta Giancarlo , Poggi Barbara
Published: March 2003

Epidemiological information on symptoms affecting extra‐respiratory organs and apparatuses in asthmatic children is scarce. The aim of this study therefore was to evaluate, at a population level, if and what extra‐respiratory symptoms are associated with asthma. Two questionnaire‐based, cross‐sectional surveys were carried out on 1,262 students (651 males; mean age 9.57 years, age‐range 6–14 years) in 1992 and on 1,210 students (639 males; mean age 9.02 years, age‐range 6–14 years) in 1998, from two elementary and two junior high schools in Rome, Italy. Questionnaires included queries about asthma and its risk factors and extra‐respiratory symptoms (headache, restlessness, sleep disturbances, urticaria, itching, and abdominal pain). Of responders, 11.9% (279/2,342) had a history of asthma. After adjustment for gender, family history of atopic disease, low birth weight, early respiratory problems, and damp house, asthma was significantly associated with recurrent abdominal pain (odds ratio [OR] 1.90; 95% confidence interval [CI]: 1.04, 3.16), itching (OR 3.15; 95% CI: 1.75, 5.68), and urticaria (OR 2.52; 95% CI: 1.02, 6.20). Asthma was reported by 10.2% (201/1,962) of children unaffected by this triad, by 20.1% (56/279; OR 2.20) with one of the symptoms, and by 31.6% (12/38; OR 4.04) with two or more symptoms. An emerging characteristic of pediatric asthma in our setting appears to be its association with certain extra‐respiratory symptoms (abdominal pain, itching, and urticaria). A global, internistic approach to asthmatic children is increasingly required both in the clinical setting and in future epidemiological studies.
Hypoproteinemia in severe childhood atopic dermatitis: A serious complication
Authors: Nomura Ichiro , Katsunuma Toshio , Tomikawa Morimitsu , Shibata Atsushi , Kawahara Hidetoshi , Ohya Yukihiro , Abe Jun , Saito Hirohisa , Akasawa Akira
Published: March 2003

As a complication of atopic dermatitis (AD), the incidence of hypoproteinemia is increasing among infants with severe AD in Japan. It can be a life‐threatening condition owing to hypovolemic shock as a result of hypoproteinemia and vascular infarction as a result of thrombocythemia. However, the pathophysiology of this condition remains unclear. The objectives of the present study were two‐fold. The first objective was to determine the main route of protein loss, i.e. through the damaged skin or the gastrointestinal tract, or as a result of insufficient food intake. The second objective was to identify whether allergy or infection was the cause of severe skin inflammation. Fifteen patients with AD were enrolled who had serum protein levels of 3.2–5.8 g/dl. Specific immunoglobulin E (IgE) and skin test to allergens, stool eosinophils, α1‐antitrypsin clearance, skin Staphylococcus aureus colonization and superantigens (SAgs) produced by the organism, serum SAg‐specific IgE antibodies, serum interleukin (IL)‐5, IL‐6, IL‐12, and interferon‐γ (IFN‐γ) were evaluated. Prominent serous skin discharge was seen in all of the patients and was found to have almost the same protein concentration as serum. Marked thrombocytosis, with a maximum of 1,060 × 103/ml, was seen. Skin culture revealed S. aureus colonization in all patients. SAg‐producing S. aureus were found in 84.6% of the patients. The concentration of serum IL‐5 was significantly increased and correlated well with the blood eosinophil count. Hence, the main route of protein loss was believed to be through damaged skin. The cause of severe inflammation was thought to be a combination of allergic inflammation and skin colonization by SAg‐producing S. aureus. Serum cytokines showed a T helper 2 (Th2) T‐cell‐mediated pattern. To prevent hypovolemic shock, vascular occlusion, and growth retardation, it is of vital importance to diagnose hypoproteinemia at an early stage and start appropriate therapy.
Domestic aeroallergen levels in Barcelona and Menorca (Spain)
Authors: Basagaña Xavier , Torrent Maties , Atkinson Warwick , Puig Carme , Barnes Maria , Vall Oriol , Jones Meinir , Sunyer Jordi , Cullinan Paul ,   the AMICS study
Published: March 2003

Exposure to common indoor allergens is known to be associated with sensitization and triggers of asthma. Levels of allergens have been barely described in Mediterranean countries. This study reports domestic allergen levels among the general population of two regions of Spain. Dust samples were collected from living rooms and mattresses in homes of infants in Barcelona (n = 366) and Menorca (n = 475) and assayed for house dust mite (Der p 1) and cat allergen (Fel d 1) concentrations by enzyme‐linked immunoabsorbent assay (ELISA). Geometric mean values (95% CI) of Der p 1 were 0.77 µg/g (0.65, 0.92) in living rooms and 0.68 (0.56, 0.82) in children's mattresses in Barcelona, and 9.06 (7.93–10.34) and 3.12 (2.71–3.59) in Menorca, respectively. Fel d 1 levels were 0.37 µg/g (0.31, 0.45) and 0.14 (0.12, 0.18) in Barcelona, and 0.42 (0.35, 0.50) and 0.20 (0.18, 0.24) in Menorca. Home characteristics were not consistently related to levels of aeroallergens in either location. Differences in Der p 1 levels in the two locations indicate that levels cannot be extrapolated from one part of a country to another with any certainty. Additionally, allergen reduction measures related to indoor sources must be specific to each location.
Evaluation of the relevance of humoral immunodeficiencies in a pediatric population affected by recurrent infections
Authors: Finocchi Andrea , Angelini Federica , Chini Loredana , Di Cesare Silvia , Cancrini Caterina , Rossi Paolo , Moschese Viviana
Published: March 2003

Recurrent infections are a common cause of morbidity in childhood. Several reports have associated this condition to low levels of IgA and IgG subclasses and/or lack of specific antipolysaccharide antibody response, although the relevance of these defects in terms of prognosis and therapeutic approach is still unclear. The aim of our study was to determine the frequency and the clinical relevance of humoral immunodeficiency (HID) other than hypogammaglobulinemia in children affected by recurrent infections. We recruited 67 pediatric patients affected by recurrent infections. Serum IgG, IgA, IgM, IgG2, IgG3, and specific anti‐Haemophilus influenzae (anti‐Hib) antibodies were determined. Thirty‐seven out of 67 patients showed antibody defects (55%). IgA deficiency was observed in 21 out of 67 patients (31%), followed by IgG2 (18%), IgG3 (15%) and IgM (6%) defects. Anti‐Hib deficiency was present in three out of 44 patients (7%). A tendency for a higher occurrence of pneumonia and otitis, although not statistically significant (p > 0.05), was observed in HID patients compared to children with normal humoral function. No statistical difference as to the frequency of mild infections (URI) was found between HID and non‐HID patients. We therefore suggest that the therapeutic program is based on the clinical status of the patients. Long‐term follow‐up with repeated determinations of antibody levels is crucial, however, to detect those defects that might evolve into more complex immunodeficiencies.
Experience of parenteral nutrition for nutritional rescue in children with severe liver disease following failure of enteral nutrition
Authors: Guimber D , Michaud L , Ategbo S , Turck D , Gottrand F
Published: March 2003

Abstract: Nutritional support is often necessary in chronic liver disease in childhood, and when enteral nutrition is insufficient, parenteral nutrition (PN) can be envisaged as a last resort. Pediatric experience is still limited in this indication. Seven children with severe liver disease received PN for a mean duration of 105 d, with additional enteral nutrition. Clinical tolerance was assessed and anthropometric and biological data were compared at the beginning and at the end of the study by the paired non‐parametric test of Wilcoxon. Weight change, expressed as weight‐for‐age or weight‐for‐height Z‐scores, increased. Conjugated bilirubin increased significantly. This retrospective study suggests that PN is a well‐tolerated method for maintaining nutritional status in pediatric chronic liver disease when enteral nutrition has failed.
Immunological recovery post‐hematopoietic stem cell transplantation: Role of prophylactic prevention of infection in  post‐transplant period
Authors: Kapoor Neena
Published: March 2003

Abstract: Immunological recovery post‐hematopoietic stem cell transplantation is variable. This depends upon the type of transplantation, source of hematopoietic stem cells for transplantation, prophylactic treatment for graft‐versus‐host disease and ongoing therapy for the treatment of graft‐versus‐host disease with immunosuppressive agents. Periodic numerical and functional assessment of recovery of the immune system after transplantation can identify the patients with inadequate immune system who are at risk for development of infectious complications. These patients should receive prophylactic therapy to decrease infection‐related morbidity and mortality associated with transplantation procedures.
Fixing the intestinal mucosa in the bone marrow transplant patient: Lessons from other intestinal immunodeficiencies and inflammatory disorders
Authors: Proujansky R.
Published: March 2003

Abstract: Gastrointestinal inflammation is common following bone marrow transplantation. Key pathogenetic events, such as major histocompatibility complex (MHC) expression on intestinal epithelial cells and local production of cytokines in the gastrointestinal mucosa, are common features of many gastrointestinal inflammatory disorders. Drawing from clinical experience of the treatment of other disorders associated with gastrointestinal inflammation, such as ulcerative colitis and Crohn’s disease, a number of therapeutic alternatives may be relevant for the bone marrow transplant patient with significant graft‐vs.‐host disease (GvHD). Options to consider include therapeutics that alter inflammatory cell migration, anti‐inflammatory cytokines, direct neutralization of proinflammatory cytokines, and cytokines that promote epithelial restitution in the gastrointestinal mucosa. In addition, a variety of nutritional and other novel treatments are available, which may improve epithelial function or which have anti‐inflammatory actions. Prospective studies of combined nutrient and cytokine‐modulating treatments for the bone marrow transplant patient are warranted.
Stem‐cell transplant preparative regimens
Authors: Sanders J. E.
Published: March 2003

Abstract: Owing to the relatively high probability of recurrent disease in patients receiving hematopoietic stem‐cell transplantation (HSCT) for malignancies, further development of new preparative regimens is warranted. Based on the data presented, one can predict that it will continue to be difficult to identify HSCT regimens that are more effective. Incremental improvements are expected to be small, difficult to measure, and will require inclusion of very large numbers of patients. Controlled trials to evaluate the effectiveness of specific treatment regimens for specific groups of patients will require to be conducted only by centers with large numbers of patients, or co‐operative groups. Development of HSCT regimens with low mortality and a minimum of morbidity, without compromising efficacy, are needed. This may be accomplished through the use of agents to protect normal, non‐hematopoietic tissues from regimen‐related toxicity (RRT), further exploration, and expansion of applications of targeted radiolabeled antibody approaches and mixed chimerism approaches. The future holds much work, but great promise, in the development of new HSCT regimens.
Use of anti‐hypertensive medications and post‐transplant renal allograft function in children
Authors: Sorof Jonathan M. , Goldstein Stuart L. , Brewer Eileen D. , Steiger Helen M. , Portman Ronald J.
Published: March 2003

Abstract: Post‐transplant hypertension is a common occurrence in children. The relative effect of this hypertension on renal allograft function is uncertain. Examining the accumulated data for pediatric renal transplant recipients at our institution from monthly visits for up to three years, we determined whether the use of anti‐hypertensive medications (anti‐HTN medications) was associated with allograft dysfunction. Monthly clinical data included height, weight, serum creatinine, cyclosporin A (CsA) trough levels, number of acute rejection episodes, and number of anti‐HTN medications. Estimated glomerular filtration rate (eGFR) was calculated monthly for each patient using the Schwartz formula. Time post‐transplant was grouped into 6‐month intervals. One thousand three hundred and sixty‐three monthly data sets from 6 months (n = 76 patients) to 3 yr post‐transplant (n = 47 patients) were analyzed. Overall mean eGFR was 75 mL/min/1.73 m2 at 6 months and 54 mL/min/1.73 m2 at 3 yr. A lower eGFR was found at all post‐transplant time intervals for patients receiving anti‐HTN medications compared with those who were not (p < 0.01). This lower eGFR was found at some but not all times post‐transplant when patients were grouped by donor type or history of acute rejection episodes and analyzed separately. Mean CsA trough levels were higher at all post‐transplant time intervals in patients receiving anti‐HTN medications (p < 0.05). While a causal relationship between post‐transplant hypertension and graft dysfunction cannot be established from this study, we conclude that the need for anti‐HTN medications is associated with worse allograft function.
Impact of FK506 and steroids on adaptation after intestinal resection or segmental transplantation
Authors: Sigalet D. L. , Williams D. C. , Garola R. , Thorne P. , Martin G.
Published: March 2003

Abstract: Segmental small intestinal transplantation (SIT) using living related donors (LRD) is being evaluated as a therapy, clinically. Advantages of this technique include an increase in the donor pool, optimization of the timing of transplants, and potential immunologic benefits. However, the ability of a short segment of intestine to function after transplantation has not been investigated in large animal models. This study evaluates the impact of immunosuppression on the adaptive process and the ability of a transplanted segment of intestine to adapt. A pig model of segmental SIT was used. Animals were resected, leaving 150 cm of distal ileum (n = 5), resected and treated with FK506 (n = 4), or steroids (n = 4), or with FK506 + steroids (n = 7), or transplanted using a similar segment of ileum and treated with FK506 + steroid immunosuppression (n = 9). Animals undergoing resection, or resection plus steroid treatment, did well, gaining weight post‐operatively (37% and 15% of preoperative weight, respectively). However, animals undergoing resection and treated with FK506 or FK506 + steroids did poorly, losing weight (–14% and –22% of preoperative weight, respectively) and showing significant impairment of intestinal adaptation, morphologically and functionally. Furthermore, FK506‐treated animals developed inflammatory changes in the intestinal mucosa, mimicking rejection. Segmental SIT animals had a high rate of rejection (66%) and showed a similar impairment in adaptation. Hence, segmental SIT is a stringent physiological test of intestinal adaptation. FK506 appears to impair gut function after resection, either directly, or by interfering with the adaptive process. In this model of segmental SIT, FK506 and steroids at the doses tested did not provide adequate immunosuppression to prevent rejection and the graft did not function adequately to allow growth. Further studies are required to evaluate the mechanisms underlying these findings, and to determine if similar effects occur in humans.
Follow‐up of chimerism, including T‐ andB‐lymphocytes and granulocytes in children more than one year after allogeneic bone marrow transplantation
Authors: Winiarski Jacek , Gustafsson Åsa , Wester Daniela , Dalianis Tina
Published: March 2003

In bone‐marrow‐transplanted children, early detection of graft failure, relapse, and other potentially treatable problems is facilitated by the use of polymerase chain reaction (PCR) assays that monitor whether blood and marrow cells are of recipient or donor origin. Presence of mixed donor–recipient chimerism (MC) within the first year after BMT frequently correlates with clinical problems. To study if MC detected one year or more post‐BMT was also often associated with clinical problems, the chimeric status in 33 children surviving 1–11 yr (median: 2 yr) after BMT was investigated. A PCR with a sensitivity of 1–2%, using fluorescent primers analyzing DNA fragment length polymorphisms, was applied. T‐ and B‐cells and granulocytes were immunomagnetically isolated and tested separately for all patients. Of the 33 patients, of whom 21 had received pretreatment including total body irradiation (TBI), 27 (82%) exhibited full donor chimerism. Six children (18%), four of whom had received pretreatment without TBI, had MC. In three of these children, all with aplastic anemia, isolated T‐cell MC had not posed apparent clinical problems. In two patients, both with MC including B‐cells, immune hemolytic anemia was observed. A sixth patient with AML presented with MC and relapse. In two of the six children MC was detected only by cell subset analysis. In conclusion, analysis of MC in leukocyte subsets is more informative than analysis of whole blood only and may reveal clinically important variations in the origin of different cell populations. The prevalence of MC is lower after the first year post‐BMT, and when present is less often associated with clinical problems.
The history of pediatric heart and lung transplantation
Authors: Mendeloff Eric N.
Published: March 2003

Abstract: As is the case with other forms of solid organ transplantation, success with heart and lung transplantation in the pediatric population was a natural extension of success with these procedures in adults. As a result, to review the history of pediatric heart and lung transplantation, one must by necessity review the landmarks in research and the events that gave way to successful heart and lung transplantation in adults.
Outcome of renal transplantation in adolescents with focal segmental glomerulosclerosis
Authors: Baum Michelle A. , Ho Martin , Stablein Donald , Alexander Steven R. ,   for the North American Pediatric Renal Transplant Cooperative Study
Published: March 2003

Abstract: Using the NAPRTCS database from January 1987 to January 2001, we examined 2687 adolescent (age 13–17 yr) index renal transplants to analyze differences in demographic treatment, and outcomes in adolescents with FSGS compared to other renal disease. 338 (12.6%) of adolescents had a primary diagnosis of FSGS. Adolescents with FSGS were more likely to be black and less likely to receive pre‐emptive transplants (p < 0.001). No differences existed in HLA matching or immunosuppression regimens. Acute tubular necrosis occurred in more FSGS adolescents compared to non‐FSGS adolescents following LD (11% vs. 4.7%) or CD (25.1% vs. 17.8%) transplants (p < 0.001). There were no significant differences in acute rejection rates between adolescents with FSGS and other adolescents. Graft survival was worse for LD FSGS adolescents (6 yr, 56%) compared to non‐FSGS adolescents (77%) (p < 0.001) and was not significantly different from CD graft survival in FSGS (51%) or non‐FSGS groups (61%). The relative risk (RR) of graft failure was greatest in LD transplant with FSGS (RR = 1.75; p < 0.001), compared to LD transplants without FSGS (RR = 1.0). Recurrent primary disease accounted for 15.2% of all graft failures in adolescents transplanted for FSGS with no difference between LD (17%) or CD (13.8%) grafts. Recurrent disease accounted for 3.2% of graft failures in adolescents without FSGS. Recurrent disease was the only cause of graft failure that differed between groups (p < 0.001). When compared to patients up to age 12 yr with FSGS, graft survival in both LD and CD transplants was worse in adolescents with FSGS (LD p = 0.035, CD p < 0.001). In conclusion, FSGS has a negative impact on graft survival in adolescents. Recurrence of FSGS results in a loss of the expected LD graft survival advantage in adolescents. Furthermore, adolescents with FSGS have decreased graft survival compared to younger children with FSGS. These data suggest that the rationale for LD transplantation in adolescents with FSGS should be based on factors other than the increased graft survival typically seen with LD transplantation.
Renal transplantation: Long‐term adaptation and the children's own reflections
Authors: Kärrfelt Helena M.E. , Lindblad Frank I.E. , Crafoord Johanna , Berg Ulla B.
Published: March 2003

Abstract: Twenty children, 9–19 yr of age, having undergone renal transplantation, were interviewed (according to a semi‐structured inquiry manual) with the aim of investigating their emotional and psychosocial adaptation. The children reported about a rather unaffected life considering the circumstances. Few of them described a negative identity in the form of feeling sick or different, and their experienced limitations appeared to be moderate. Anxiety about the future was more salient, but nevertheless the children seemed to have found a good way of living with this anxiety. When comments were made on the relationship to the donor, they were of a positive character; the relationship had been improved by the donation. Only one child – who had received a kidney from a deceased person – described fantasies of the alien kidney of a markedly unpleasant character. The psychological adaptation of the children frequently seemed to imply the use of potentially dysfunctional defense mechanisms like denial and avoidance.
The pediatric risk of mortality score in infants and children with fulminant liver failure*
Authors: Tissières Pierre , Prontera Walter , Chevret Laurent , Devictor Denis
Published: March 2003

Abstract: The pediatric risk of mortality (PRISM) score as a severity scoring system has never been assessed in infants and children with fulminant liver failure (FLF). A retrospective case study of 109 infants and children admitted in a 22‐bed pediatric and neonatal intensive care unit of a tertiary university hospital, National Referral Center for Pediatric Liver Transplantation, from March 1986 to August 1997 was carried out. PRISM score was not significantly different within etiologic FLF categories, or between infants and children. However, PRISM score (mean ± SD) showed significant difference (p = 0.001) between the 27 patients who spontaneously recovered with supportive care (8.8 ± 5.0) and 82 patients who underwent emergency liver transplantation (ELT) or those who died before (14.9 ± 7.7). PRISM score‐based probability of mortality was underestimated when compared with observed mortality. A death probability higher than 20% had a 24% sensitivity and 95% specificity for severe outcome. Reciever operating characteristic curve for PRISM score showed elevated discriminative power (Az = 0.91) for discerning children with severe outcome from those who spontaneously recovered with supportive care. A PRISM score more than 10 showed an odds ratio of 2.69 for predicting severe outcome (95% CI: 1.11–6.55; p = 0.038). In conclusion, the PRISM score is an accurate means of severity assessment in pediatric FLF. However, PRISM score‐based mortality was of low predictive value.
Recommendations for immunizations in stem cell transplantation
Authors: Molrine Deborah C.
Published: March 2003

Abstract: Investigations over the past decade have documented that there is a decline in immunity to vaccine preventable diseases in many SCT recipients. The majority of immunization studies conducted in SCT recipients to date support the use of multi‐dose regimens for most protein and polysaccharide‐conjugate vaccine antigens. The consensus immunization schedule recommended by ACIP/IDSA/ASBMT provides guidance for centers to utilize available vaccines in their SCT populations. With the exception of pneumococcal disease, a schedule beginning at 12 months after SCT is reasonable given the low incidence of disease in HSCT recipients for most of the recommended vaccines and improved immune reconstitution in most recipients by one year post transplant. SCT recipients respond poorly to unconjugated pneumococcal polysaccharide vaccine and the development of polysaccharide‐protein conjugate vaccines against S. pneumoniae holds promise to impact potentially on clinical disease in this population. In addition, the strategy of donor immunization may also be effective in eliciting early protective immune responses to vaccine antigens. Future challenges will be the development of safe and effective vaccines against the viral pathogens responsible for considerable morbidity and mortality after SCT.
The expanding applications of non‐myeloablative stem cell transplantation
Authors: Spitzer Thomas R.
Published: March 2003

Abstract:  Non‐myeloablative preparative strategies for allogeneic stem cell transplantation (SCT) have been increasingly utilized for a variety of hematological malignancies, solid tumours, and for tolerance induction. These regimens are associated with less transplant‐related morbidity and mortality than conventional transplant conditioning regimens. It is not yet clear whether graft‐vs.‐host disease (GVHD) protection is afforded. Potent antitumour responses have been described in a variety of advanced malignancies. We have utilized a cyclophosphamide/anti‐T‐cell antibody therapy approach, which has resulted in the uniform induction of mixed chimerism. In many cases, this has served as an immunological platform for adoptive cellular immunotherapy (via donor leukocyte infusions). The results of this experience, as well as the outcomes of non‐myeloablative stem cell transplantation (NST) for other malignant and nonmalignant conditions are described.
Interaction of gibberellins and phytochrome in the control of cowpea epicotyl elongation
Authors: Martínez‐García Jaime F , García‐Martínez José L.
Published: March 2003

The physiological response of cowpea (Vigna sinensis L.) epicotyl explants to far‐red light (FR) and its interaction with gibberellins (GAs) have been investigated. The effect of FR and GA1 varied with the age of the seedlings from which the explants were made: for FR, it decreased progressively with age (though the sensitivity of the epicotyls to FR did not change significantly until at least day 11), whereas it remained essentially constant for applied GA1 between days 5 and 9 after sowing. This indicates that the loss of response to FR may be due to a decrease in endogenous GA levels in the epicotyl. For a range of GA1 and GA20 (0.01–1 µg explant−1), both hormones were more active in FR than in R irradiated epicotyls, suggesting that phytochrome may affect GA sensitivity besides GA metabolism. The location of the epicotyl region most sensitive to FR (between 5 and 20 mm below the apex) was different from that to GAs (the upper 10 mm). Nevertheless, FR extended the region responsive to applied GAs, even in paclobutrazol‐treated epicotyls where elongation was due entirely to exogenous GAs. This means that modulation of epicotyl elongation by phytochrome, that occurs in a zone different from though overlapping with the GA‐sensitive subapical zone, is also mediated by GAs. Growth in the most FR‐sensitive region of the epicotyl stimulated by FR or GA1 was due to cell elongation, and in the most GA‐sensitive region to both cell division and elongation. The effect of FR and GA1 was negated by colchicine, indicating that microtubules may be involved in the response to both factors.
Cloning and sequencing of the cDNAs induced by aluminium treatment and Pi starvation in cultured tobacco cells
Authors: Ezaki Bunichi , Yamamoto Yoko , Matsumoto Hideaki
Published: March 2003

With the ultimate purpose of clarifying the mechanism for aluminium (Al) toxicity and for Al tolerance, we tried to isolate cDNAs whose expression is induced by Al treatment and phosphate (Pi) starvation. We performed Pi starvation and Al treatment (two‐step treatment) on suspension‐cultured cells of Nicotiana tabacum L. cv. Samsun and then constructed a cDNA library using poly(A)+‐RNA derived from the treated cells. Four independent cDNA clones (pAL 111, 139, 141 and 142) were isolated from the library by differential screening. Northern blot hybridization analysis indicated that the expression of these clones was induced by Pi starvation. Furthermore, we found that pAL 111 and pAL 142 are also induced by Al treatment. The complete cDNA sequencing of these 4 clones was determined. The results indicated that pAL111 is identical to the parA gene of N. tabacum, which is described as an auxin‐regulated gene and that pAL142 is highly homologous to the parB gene of N. tabacum whose product has glutathione S‐transferase (GST, EC 2.5.1.18) activity. Furthermore, we found a cysteine‐rich domain in the amino acid sequence of pAL139. No DNA and deduced amino acid sequences homologous to the pAL141 were found.
Differential involvement of abscisic acid in dehydration and osmotic stress in rice cell suspension
Authors: Leonardi Agnès , Heimovaara‐Dijkstra Sjoukje , Wang Mei
Published: March 2003

Plant cells react to different environmental stimuli in different ways. The plant growth regulator abscisic acid (ABA) has been reported to be produced and involved in stress responses. To understand the role of ABA in relation to stress responses, we chose the ABA‐induced RAB (responsive to ABA) gene as a marker to study both dehydration and osmotic‐induced stress responses in rice cell suspensions. The kinetics of RAB gene expression under ABA, dehydration and mannitol treatments were studied. Dehydration‐induced RAB expression was slower as compared to both ABA‐ and mannitol‐induced RAB gene expression. Under dehydration conditions, the expression of RAB gene was correlated with an increase in endogenous ABA levels. Inhibition of protein or ABA synthesis prevented RAB expression under dehydration treatment. Under mannitol treatment, the RAB mRNA accumulated as fast as with ABA treatment, though there was no endogenous ABA accumulation. Inhibition of protein synthesis had no effect on mannitol‐induced RAB gene expression. Proton pump inhibitor, calcium channel and outward rectifying potassium channel blockers reduced both dehydration‐ and mannitol‐induced RAB gene expression. The potassium channel blocker BaCl2 reduced mannitol‐induced RAB gene expression while it had no effect on dehydration‐induced RAB gene expression. The possible differences in signal transduction between dehydration and osmotic stress are discussed.
Growth enhancement and antitranspirant activity following seed treatment with a derivative of 5‐hydroxybenzimidazole (Ambiol) in four drought‐stressed agricultural species
Authors: Darlington A. , Vishnevetskaia K. , Blake T. J.
Published: March 2003

The biostimulating action of seed treatment with the synthetic antioxidant, Ambiol (2‐methyl‐4‐Edimethylaminomethyl‐5‐hydroxybenzimidazole dihydrochloride) on subsequent growth and transpiration of seedlings was studied. To study growth and transpiration responses, seeds of four agricultural species, soybean (Glycine max L.), rapeseed (Brassica napus L.), winter wheat (Trilicum aestivum L.) and corn (Zea mays L.), were soaked in Ambiol for 24 h, using the following concentrations: 0, 0.01, 0.1, 1, 10 and 100 mg 11. The subsequent seedlings were subject to simulated soil drought, using computer‐automated root misting chambers. The influence of Ambiot on transpiration rate under simulated air drought was studied by growing plants under low humidity in a controlled humidity chamber. Response to Ambiol varied, depending on its concentration, the species used and the environment. Compared to untreated plants, 10 mg 1‐−1 Ambiol reduced the mid‐day transpiration rate and total daily water usage of soybean by approximately 25%. Under simulated soil drought in the root misting chamber, 10 and 100 mg 1‐−1 Ambiol increased growth of rapeseed and soybean by 25–45%, relative to the 0 mg 1‐−1 treatment, yielding plants comparable in size to the fully‐irrigated controls. However, Ambiol failed to promote growth of two drought‐stressed monocotyledons (corn and winter wheat). At 100 mg P. Ambiol inhibited growth of both well‐watered wheat and rapeseed, although this inhibition was mitigated by drought.
The measurement of water relations of plant cell culture. I. Water release in response to centrifuge‐induced water potentials
Authors: Reaney Martin J. T. , Livingston Nigel J. , Gusta Lawrence V.
Published: March 2003

Water loss by cell suspensions during centrifugation is well defined by simple physical principles. The major factors affecting water release during centrifugation are: duration of centrifogation, depth of the cell mass, density of cells, relative centripetal acceleration and centripetal force. Water release during centrifugation was best described by an exponential decay process with a decay constant that increases with acceleration from 0.31 ± 0.01 to 0.66 ± 0.12 min−1 (mean ± SE) between 4 825 and 19 300 m s−2, respectively. The cell mass relative water content (RWC) at equilibrium was not a function of rate of water loss and was constant for each acceleration. A centripetal force was generated by the mass of the cells being accelerated away from the axis of rotation. This force generated a pressure that removed some of the cell wall and symplast water, by compression at contact points between the cells and by compression of the cytoplasm. Pressure induced by centripetal forces ranging from −0.02 to −0.23 MPa gave a linear relationship (r2 > 0.99) between force and RWC. The slope (0.900 MPa) was proportional to the cell wall modulus of elasticity (±). and the intercept was interpreted to give the mass of the cells at full turgor without interstitial water (RWC=1). This interpretation is supported by the findings, of two independent experiments. Centrifuged cells suspended at 100% relative humidity for over 48 h reached the same water content as predicted by the intercept. Interstitial water was labelled with solutions of polyethylene glycol (PEG. Mr 8 000), the diameter of which was too large to enter the pores of plant cell walls. Centripetal accelerations greater than 10 900 m s−2 removed PEG‐labelled water to levels below 0.9% of cell water content. Removal of interstitial water and other loosely bound water provided a convenient method for determination of growth, RWC and ±. The centrifugal methods provide the foundation for new quantitative methods for cell culture water relations analyses.
Distribution of mineral nutrient from nodal roots of Trifolium repens: Genotypic variation in intra‐plant allocation of 32P and 45Ca
Authors: Lötscher M. , Hay M. J. M.
Published: March 2003

To assess genotypic variability in nutrient supply of shoot branches, the distribution of 32P and 45Ca exported from a source nodal root (24‐h uptake period) was measured within a genotype of a large‐leaved (Kopu) and a small‐leaved (Tahora) cultivar of Trifolium repens. Source‐sink relationships of plants were modified by root severance, defoliation, and shade treatments. In control plants of both genotypes distribution of 32P and 45Ca closely followed the pathways that could be predicted from the known phyllotactic constraints on the vascular system. As such there was little allocation of radioisotopes (3.1% and 2.5% of exported 32P and 45Ca, respectively) from the source root to branches on the apposite side of the parent axis (far‐side branches). However, genotypic differences in nutrient allocation were apparent, when treatments were imposed to alter intra‐plant source‐sink relationships. In the large‐leaved genotype, the imposed treatments had minor effects on the allocation to far‐side branches: whereas, in the small‐leaved genotype, root severance and defoliation treatments increased lateral transport to far‐side branches to 30% (32P) and 10% (45Ca) of exported radioisotopes. Genotypes with low (8–9) and high (12–13) numbers of vascular bundles were selected from within the large‐leaved cultivar. Distribution of 32P was then measured after plants had been pre‐treated by removal of all far‐side roots two days prior to labelling. Genotypes with low vascular bundle number allocated 20% and those with high vascular bundle number 3.2% of exported 32P to far‐side branches. It was concluded (1) that genotypic variation exists within T. repens for potential to alter intra‐plant allocation of mineral nutrients, in response to treatments that modify source‐sink relationships within plants; and (2) that this variation is correlated with differences among genotypes in the organisation of the vasculature of their stolons.
Using chlorophyll fluorescence to assess the fraction of absorbed light allocated to thermal dissipation of excess excitation
Authors: Demmig‐Adams Barbara , Adams III William W. , Barker David H. , Logan Barry A. , Bowling David R. , Verhoeven Amy S.
Published: March 2003

In the present study we explored the possibility of assessing the allocation of photons absorbed by photosystem II (PSII) antennae to thermal energy dissipation and photosynthetic electron transport in leaves of several plant species under field conditions. Changes in chlorophyll fluorescence parameters were determined in situ over the course of an entire day in the field in sun‐exposed leaves of two species with different maximal rates of photosynthesis, Helianthus annuus (sunflower) and Vinca major. Leaves of Vinca minor (periwinkle) growing in a deeply shaded location were also monitored. We propose using diurnal changes in the efficiency of open PSII centers (F′v/F′m) in these sun and shade leaves to (a) assess diurnal changes in the allocation of absorbed light to photochemistry and thermal energy dissipation and, furthermore, (b) make an estimate of changes in the rate of thermal energy dissipation, an analogous expression to the rate of photochemistry. The fraction of light absorbed in PSII antennae that is dissipated thermally (D) is proposed to be estimated from D = 1‐F′v/F′m, in analogy to the widely used estimation of the fraction of light absorbed in PSII antennae (P) that is utilized in PSII photochemistry from P = F′v/F′m× qP (where qP is the coefficient for photochemical quenching; Genty, B., Briantais, J.‐M. & Baker, N. R. 1989. Biochim. Biophys. Acta 990: 87‐92). The rate of thermal dissipation is consequently given by D × PFD (photon flux density), again in analogy to the rate of photochemistry P × PFD, both assuming a matching behavior of photosystems I and II. Characterization of energy dissipation from the efficiency of open PSII centers allows an assessment from a single set of measurements at any time of day; this is particularly useful under field conditions where the fully relaxed reference values of variable or maximal fluorescence needed for the computation of nonphotochemical quenching may not be available. The usefulness of the assessment described above is compared with other currently used parameters to quantify nonphotochemical and photochemical chlorophyll fluorescence quenching.
Responses of photosynthesis to NaCl in gametophytes of Acrostichum aureum
Authors: Li Mao‐Ping , Ong Bee‐Lian
Published: March 2003

Gametophytes of Acrostichum aureum were cultured in 0.0 to 1.0% NaCl solutions or in NaCl‐free solution and then transferred to 1.0% NaCl solution. Photosynthetic light‐response curves, efficiency of the primary photochemical reaction, relative electron transport rate, and photochemical and non‐photochemical quenching at steady state were determined by photosynthetic O2 evolution and in vivo chlorophyll fluorescence. Results obtained showed that the chlorophyll fluorescence parameters, Fv/Fm and F'v/F'm and αO2 (the initial linear slope of the photosynthetic light‐response curve) increased in gametophytes grown in NaCl. Linear electron transport rate was stimulated by NaCl. Based on the chlorophyll content, light‐saturated photosynthesis in gametophytes grown in 0.2 to 0.7% NaCl increased slightly; it decreased in gametophytes grown in 1.0% NaCl. Photochemical quenching decreased in NaCl‐grown gametophytes at all photosynthetic photon flux density (PPFD) levels measured, but there was no increase in non‐photochemical quenching. The chlorophyll a/b ratio increased with increasing NaCl concentration in culture solutions. These results indicated that NaCl enhanced photochemical efficiency of photosystem II (PSII) and photosynthetic linear electron transport, thus resulting in the development of an excitation pressure in PSII. Such excitation pressure might act as a signal for photosynthetic acclimation to salt stress, thus allowing the gametophytes to grow in their natural habitats.
Interactive effects of photon fluence rates and drought on CAM‐cycling in Delosperma tradescantioides (Mesembryanthemaceae)
Authors: Herppich Werner B. , Midgley Guy F. , Herppich Margaretha , Tüffers Arnd , Veste Maik , Von Willert Dieter J.
Published: March 2003

The ability of photosynthesis and CAM to acclimate to low (220 µmol m−2 s−1; LL) and relatively high (550 µmol m−2 s−1; HL) photosynthetic photon flux densities (PPFD) was investigated in the CAM‐cycling species Delosperma tradescantioides by means of CO2 gas exchange and chlorophyll fluorescence analysis. Furthermore, the influence of short‐term drought on malic acid accumulation and the activity of photosystem II (PSII) was studied to assess the possible interactions between drought and the prevailing PPFD in this species. HL plants showed features of sun versus shade acclimation relative to LL plants. Nocturnal malic acid accumulation (Δ‐malate) and leaf water content also tended to be higher in HL plants. Irrespective of the PPFD during growth, the weak Δ‐malate doubled within 3 days of drought. Despite largely restricted CO2 uptake, photosynthetic activity as estimated from fluorescence analysis declined only ca 5%. After 7 days of drought, when plants showed CAM‐idling and Δ‐malate had decreased again, potential carbon assimilation was still ca 84% of that in well‐watered plants and remained relatively constant throughout the day. Decarboxylation of malic acid accounted for ca 23% of potential assimilation assuming total oxidation of a maximum portion of this organic acid. Drought did not affect predawn maximum photochemical efficiency (Fv/Fm). Nonphotochemical quenching (qN) increased (24%) in response to desiccation and resulted in a more or less constant reduction state of PSII. This increase in qN resulted mainly from the change in its fast‐relaxing component (qNF), while the slow component (qNS) was significant only at or above saturating PPFD in both HL and LL plants. The photon response characteristics of PSII, which differed between LL and HL plants, were unaffected by short‐term drought. Photon harvesting and photon use were always adjusted to guarantee a low reduction state of PSII. Results suggest that in both LL and HL plants CAM‐cycling may help to stabilize photosynthesis but to a large extent by other means than simply providing internally derived CO2.